However, if the same theoretical methods are used for analysis of actual experimental data, the apparent diffusion constants obtained are orders of magnitude lower than those in diluted aqueous solutions. Thus, it can be concluded that local restrictions of diffusion of metabolites in a cell are a system-level properties caused by complex structural organization of the cells, macromolecular crowding, cytoskeletal networks and organization of metabolic pathways into multienzyme complexes and metabolons. This results in microcompartmentation of metabolites, their channeling between enzymes and in modular organization of cellular metabolic networks. The perspectives of further studies of these complex intracellular interactions in the framework of Systems Biology are discussed.Problems of quantitative investigation of intracellular diffusion and compartmentation of metabolites are analyzed. Principal controversies in recently published analyses of these problems for the living cells are discussed. It is shown that the formal theoretical analysis of diffusion of metabolites based on Fick's equation and using fixed diffusion coefficients for diluted homogenous aqueous solutions, but applied for biological systems  IndeeMay 2007  and anotMay 2007 , concernMay 2007 , arrive l., 2007 , howeverl., 2007 . Both stl., 2007 , 29. The [et al.  is basedAnalysis of these two conflicting articles and their different historical and ideological backgrounds is most intriguing for the discussion of possible directions of development of strategies of metabolic research in the future. This is especially important because of the very rapid emergence of Systems Biology that is largely based on the application of mathematical modeling methods to systems with various complexities, in which compartmentation becomes one of the most important system – level properties, not predictable from the properties of isolated components only , 30–34.2/s [Biophysical Journal with most remarkable results, e.g. what seemed most unrealistic to Barros and Martinez was, by analysis of experimental data by Selivanov et al. [Biophysical Journal another article supported this conclusion: Iancu et al. [Barros and Martinez  consider2/s . The fac2/s . Thus, t2/s –27 were 2/s . No expe2/s . Howeverv et al. , found tv et al. . In the u et al.  presenteu et al. –37. Thesu et al. , is cleau et al. .et al. [Diffusion of metabolites in organized intracellular media has been studied for several decades with very clear results showing its restriction due to many physical factors and a multitude of parameters that are characteristic for the intracellular milieu , 38–40. et al. , and a met al.  and Smolet al. . The latet al. . Fick's where the D is diffusion coefficient or diffusivity.Both Einstein and Smoluchowski described diffusion at a microscopic level, describing its molecular mechanism – the Brownian movement –47. The 2/4t and D = λ2/6t, respectively [This equation was found for the movement in one dimension –47. For ectively –47. ThesD described by Einstein – Smoluchowski's equation is related to the particle radius r and the viscosity of the medium η by Stokes – Einstein equation [The diffusion coefficient or diffusivity equation –47:et al. have found that at least eleven conditions assumed in derivation of Fick's law and the Einstein – Smoluchovski model are not entirely met in the intracellular milieu [d)−1 where C is concentration of binding sites and Kd is dissociation constant of solute from these complexes [2 where Δλ is relative increase in path attributable to the barriers [et al. even recommend not to use “diffusivities” or “diffusion coefficients” for biological systems but to use some terms of the type of “empirical transport coefficient” when the Fick's equation is formally applied for intracellular processes [Dapp “, Dapp = DFxD0, where Do is the diffusion coefficient in bulk water phase and DF is a diffusion factor accounting for all intracellular mechanisms locally restricting particles movement [DF value in some areas of cells, for example in myofibrils, close to sarcolemma and mitochondrial outer membrane may be in the range of 10−2–10−5 [All these classical theories have been developed for weakly interacting rigid particles at sufficiently low concentrations. Agutter r milieu –40. The r milieu –40. Thenbarriers –40. Finabarriers –49. Agutmovement , 26, 50.movement , 51, 52 0−2–10−5 , 50–52.The results of these local diffusion restrictions are microcompartmentation of metabolites and their channeling within organized multi-enzyme complexes which need to be accounted for to explain many biological phenomena. Indeed, none of the important observations in cellular bioenergetics could be explained by a paradigm describing a viable cell as a “mixed bag of enzymes” with homogenous metabolite distribution, since this simplistic theory excludes any possibility of metabolic regulation of cellular functions.et al., who showed that only due to this important characteristics of intracellular medium, the apparent diffusion coefficients may be decreased by order of magnitude depending upon the size of the diffusing particles and occupied volume fraction [The first phenomenon to be taken into account in all cells is macromolecular crowding: the high concentrations of macromolecules in the cells –9 decreafraction .At first sight, this macromolecular crowding should cause a real chaos by making intracellular communication by diffusion of reaction intermediates very difficult. This chaos and related problems are well described by Noble in his recent book . In real31P-NMR, showed that the diffusions of ATP and phosphocreatine both are anisotropic in muscle cells [in situ in permeabilized cardiac cells also showed that ADP or ATP diffusion in cells is heterogeneous and that the apparent diffusion coefficient for ADP (and ATP) may be locally decreased  by an order, or even several orders of magnitude [Many new experimental techniques have been developed to study the molecular networks formed by protein–protein interactions . In the le cells , 58. Recagnitude . A similagnitude , 52. In agnitude . There iDue to molecular crowding and hindered diffusion cells need to compartmentalize metabolic pathways in order to overcome diffusive barriers. Biochemical reactions can successfully proceed and even be facilitated by metabolic channeling of intermediates due to structural organization of enzyme systems into organized multienzyme complexes. Metabolite channeling directly transfers the intermediate from one enzyme to an adjacent enzyme without the need of free aqueous-phase diffusion , 49, 60.macrocompartments – subcellular regions which are large relative to the molecular dimension, and microcompartments which are of the order of the size of metabolites. Compartment means “subcellular region of biochemical reactions kinetically isolated from the rest of cellular processes” [via microcompartments or by direct transfer [Thus, the principal ways and mechanisms of organization of cell metabolism are macro- and microcompartmentation, metabolic channeling and functional coupling. By definition, the term compartmentation is usually related to the existence of intracellular ocesses” , 62. Macocesses” –67 and oocesses”  has beenocesses” , 21. Mulocesses” . Thus, tocesses” –67, Krebocesses”  and manyocesses” , 71. Newocesses” , 37. Mictransfer , 49, 60.Interestingly enough, there is an exciting hypothesis that these phenomena, in particular metabolic channeling, are even older than life itself and related to its origin. Edwards and others .[in vivo , 90. Pau[in vivo . As anot[in vivo . These c[in vivo . ATP inhntration , 52. Aga [et al.  showed tartments , 79, 84.2+ microdomains (Ca2+ sparks) which form a discrete, stochastic system of intracellular calcium signaling in cardiac cells [in vivo kinetics of the energy transfer by which high-energy phosphoryl fluxes through creatine kinase, adenylate kinase and glycolytic phosphotransfer, captured with 18O-assisted 31P-NMR, were shown to tightly correlate with the performance of the myocardium under various conditions of load [31P-NMR saturation or inversion transfer methods [et al. [Remarkably, in the heart the intracellular energy transfer networks are structurally organized in the intracellular medium where macromolecules and organelles, surrounding a regular mitochondrial lattice, are involved in multiple structural and functional interactions –27, 34. ac cells . The strac cells –87. Thesac cells , 83–90. ac cells , 96 usinac cells , 61. To ac cells –27. Due ac cells , 83–90.  of load , 98, imp methods , 100. Mo methods . All the methods . Similar methods –37. This [et al. . These a [et al. . In addi [et al. . These m [et al. , 104 and [et al. . The aut [et al. .31P-NMR global creatine kinase flux in muscle in vivo, some laboratories [Biophysical Journal [31P-NMR flux behaviour of the creatine kinase system in creatine kinase knock-out mice or such with graded expression of creatine kinase [Some 10 years ago, based on measurements, utilizing a new technology that made it possible to directly measure by saturation transfer ratories , 106 camratories  saying t Journal , and tha Journal  and on ae kinase , 108, ase kinase . Now, ite kinase .However, modern biophysical chemistry can no longer be restricted to classical theories of diluted homogenous solutions, as misleadingly taken by Barros and Martinez . The secin vivo situation for cells that possess an extensive myofilament lattice, as muscle cells, or a dense cytoskeletal an mitochondrial network and other diffuson restrictions inferred by intracellular organization or macromolecular crowding. Moreover, biological sciences witness now a radical change of paradigms. Reductionism that used to be the philosophical basis of biochemistry and molecular biology, when everything from genes to proteins and organelles was studied in their isolated state, are superseded by Systems Biology, a holistic view that favours the study of integrated systems at all levels: cellular, organ, organism, and population, accepting that the physiological whole is greater than the sum of its parts [in vivo situation is much more realistically described and well illustrated by Selivanov et al. [in vivo situation. Apparent diffusion coefficients Dapp and diffusion factors DF (see above), as well as compartmentation, are system level properties not predictable from isolated components but arising from their interactions [in situ and, upon proteolytic digestion and determintation of the isotopically labeled peptides by mass spectrometry, sift through large protein sequence data bases to identify the cross-linked peptides and attribute them to the original partner proteins that at the time and conditions of chemical cross-linking did interact with each other [What modern biophysical chemistry needs is to critically reevaluate of use of the principles of classical physical chemistry that have been worked out for diluted aqueous solutions and to adapt these concepts to the ts parts , 30–34. ts parts . The sitts parts , who conv et al. . Clearlyv et al.  also revractions , 33. Higch other .


Although various drugs for its treatment have been synthesized, the occurring side effects have generated the need for natural interventions for the treatment and prevention of hypertension. Dietary intervention such as the administration of prebiotics has been seen as a highly acceptable approach. Prebiotics are indigestible food ingredients that bypass digestion and reach the lower gut as substrates for indigenous microflora. Most of the prebiotics used as food adjuncts, such as inulin, fructooligosaccharides, dietary fiber and gums, are derived from plants. Experimental evidence from recent studies has suggested that prebiotics are capable of reducing and preventing hypertension. This paper will discuss some of the mechanisms involved, the evidence generated from both  In ordePrebiotics are non-digestible food ingredients that can escape digestion under the harsh conditions of the upper gastrointestinal tract and reach the lower gut as substrates for the fermentation by selective indigenous gut microflora. Most of the prebiotics studied are plant derivatives such as fructooligosaccharides (FOS), inulin and fibers. FOS contains 2 to 10 fructose units linked by glycosidic bonds, while inulin is a fructose polymer with β-(2-1) glycosidic linkages with chains of 3 to 60 units. Both FOS and inulin are found abundantly in chicory and artichokes. The major component of chicory root is inulin. Inulin belongs to the fructan family, and occurs naturally as important storage carbohydrates. Other than chicory, fructans are also found present in artichokes, salsify, asparagus and onions . Plant fThis paper will discuss some of the antihypertensive mechanisms that have been documents. This paper will also discuss some of the experimental evidence on the antihypertensive properties of plant derived prebiotics, with emphasis on their hypocholesterolemic and hypoglycemia effects. However, controversies have arisen where some studies showed promising results while others exhibited insignificant findings. Thus, this paper will also highlight some of these controversies.2.Various mechanisms have been postulated to explain the ability of prebiotics to reduce the risk of hypertension. One of the possible mechanisms is via the lowering of blood lipid and cholesterol. Previous studies have demonstrated that intensive reduction of cholesterol may be beneficial in the treatment of patients with isolated systolic hypertension . The lipet al. [et al. [Soluble prebiotics such as pectin, konjac mannan and modified starches are soluble in solutions leading to a thickening and viscous effect. Such physicochemical properties have been found to affect physiological responses such as the lowering of blood cholesterol, and increasing satiety by delaying gastric emptying and a reduced speed of gastric transit in the upper gastrointestinal tract. Levrat-Verny et al.  evaluate [et al.  proposed [et al. . This ov [et al. .et al. [et al. [In another study, Lairon et al.  suggesteet al. . Obesityet al. . Therefoet al. . GLP-1 iet al. . This co [et al.  had prev [et al. .Another possible mechanism by which prebiotics could regulate blood pressure includes the attenuation of insulin resistance . Insulinet al. [+ have been found to exchange for Ca2+ in the distal colon regions [2+ which favour passive diffusion and consequently absorbed by the human colon [Additionally, prebiotics have also been reported to reduce the risk of hypertension by improving the absorption of mineral such as calcium in the gastrointestinal tract . Past stet al.  conducteet al. . Howeveret al. . The conet al. . Prebiotet al. . Therefoet al. . Prebiot regions . This woan colon .3.in-vivo trials , LDL-cholesterol concentration by 25.9% (P<0.01), IDL-cholesterol level by 39.4% (P<0.001) and VLDL-cholesterol concentration by 37.3% (P<0.05) compared to the control group.In a study evaluating the influence of prebiotics on cholesterol, Mortensen et al.  administP<0.02) and LDL-cholesterol (P<0.005) by 8.7% (± 3.3) and 14.4% (± 4.3), respectively compared to the control. In another study, Rault-Nania et al. [P<0.05) decrease in hepatic triglycerides concentration as compared to those in the control group, whereby the blood pressure of those on inulin and oligofructose were in the range of 138.0 ± 2.2 and 136.9 ± 2.0 mm Hg respectively, while the control showed a blood pressure of 145.8 ± 1.3 mm Hg.Davidson and Maki  conductea et al.  found thet al. [P<0.05) hepatic triacylgylcerol by 48% compared to the control group. In another study, Busserolles et al. [P<0.05) decline of 0.33% in hepatic triacylglycerol as compared to the control. These studies provided the experimental and clinical evidence that the supplementation of prebiotics such as inulin and oligofructose could be used as a mean to control hypertension.Hypertriglyceridemia is often associated with a moderate hyperglycemia and insulinemia , and preet al.  administs et al.  found th3.2.et al. [P<0.05) reduced serum glucose. Similarly, Kok et al. [P<0.05) reduced blood glucose by 26.0% as compared to those of the control group which only showed a reduction of 9.7%, which was insignificant statistically. The finding indicated that diet supplemented with oligofructose was effective in reducing blood glucose and indirectly could alleviate the risks of hypertension.Experimental evidence has also demonstrated that diabetes elevates the risk of hypertension . Dietaryet al.  administet al.  found thk et al.  studied P<0.05) improvement of glucose intolerance as compared to the control. Giacco et al. [P<0.02) reduction of postprandial insulin response as compared to those in the placebo group which did not show any significant differences.Similarly, Suzuki and Hara  studied o et al.  evaluatein-vivo trials.Various studies have highlighted the beneficial effects of prebiotics on physiological conditions such as lipid and glucose profiles that are directly associated with hypertension. Hence, there is a strong basis for continuous evaluation on prebiotics specifically aimed at utilizing longer and larger 4.et al. [et al. [Epidemiological studies have found that hypertensive patients frequently have a high level of serum cholesterol. Blood pressure and cholesterol are closely related and many researches have demonstrated that the lowering of cholesterol contributes to antihypertension effects. Thus, an increase in both serum cholesterol and triglycerides had been reported to elevate blood pressure values . Accordiet al.  and Ferr [et al. , blood pet al. [et al. [According to Luo et al. , blood l [et al.  showed tet al. [et al. [In another study, Pedersen et al.  reported [et al.  also sho [et al. , fifty-eet al. [et al. [Jenkins et al.  used a cet al. . Fermentet al. . Accordi [et al. , acetateet al. [et al. [et al. [et al. [The concordance of hypertension and diabetes is increased in the population and hypertension is disproportionately higher in diabetics . High blet al.  previous [et al.  also sho [et al.  demonstr [et al.  evaluateFuture studies aimed at investigating the effects of prebiotics on serum cholesterol or blood glucose concentration should consider the choice of subjects and the length of the supplementation period. Past studies investigating on the effects of NDO such as inulin and FOS in humans on hypertension remains relatively controversial. However, considering the vast experimental evidence on their positive roles, the potential of prebiotics as an antihypertensive agents warrant further investigations.5.in-vitro experiments and in-vivo trials have exhibited the need for further evaluation of the antihypertensive properties of plant-based prebiotics.Results from recent studies support the antihypertensive potential of plant-based prebiotics, and shown that they could exert such a beneficial effect via various mechanisms. Although controversial findings are raised, positive outcomes from both


Amiodarone, a class III antiarrhythmic drug, has been found to be effective in the management of patients with life-threatening ventricular arrhythmias. The aim of this study was to test whether the co administration of vitamin-E with amiodarone can reduce amiodarone-induced liver damage.Twelve male albino rats were divided into three groups (ml vegetable oil/day by oral gavages daily for 2 weeks and were used as control group. The rats of the second group received 5.4 mg amiodarone/100 gm rat dissolved in vegetable oil daily by oral gavages for 2 weeks. In the third group, the rats received 5.4 mg amiodarone and 5 mg vitamin-E/100 gram rat dissolved in 2 ml vegetable oil by oral gavages daily for 2 weeks. Two weeks after treatment, the rats were sacrificed and liver specimens were immediately taken and processed for transmission electron microscopic examinations.Sections from the rat liver receiving amiodarone examined by electron microscopy showed disrupted hepatocytes with increased vacuolations. Degenerated organelles and disrupted nuclei were observed. The microvilli of bile canaliculi were disrupted and the hepatocytes showed increased lipid contents. Both endothelial cells and Kupffer cells were damaged. Phospholipids inside the mitochondria showed a loss of cristae. Sections from the liver of rats received amiodarone and vitamin-E showed lesser effects, especially in depositions of phospholipids in the mitochondria and the whole organelles and the nucleus showed minor damage in comparison to the previous group.Milder hepatotoxic effects are seen in rats administered amiodarone and vitamin E simultaneously suggesting that vitamin-E may play a role in amelioration of the effects of amiodarone. In addit13et al and Boltal[et al, found thal[et al,9 Amiodaral[et al, Characteal[et al,The antioxidant vitamin-E was shown to reduce lysosomal phospholipidosis and amioThe aim of this study was to test whether the co-administration of vitamin-E with amiodarone can reduce amiodarone-induced liver damage using the electron microscope.et al.[Twelve male albino rats were divided into three groups of four rats each. In the first group, the rats received 2 ml vegetable oil/day by oral gavages daily for 2 weeks and were used as a control group. The rats of the second group received 5.4 mg amiodarone (chlorhydrate D') from Sanofi, France; /100 gm dissolved in vegetable oil daily by oral gavages for 2 weeks. This corresponds to the maximum human daily therapeutic dose converted into the equivalent rat dose according to Paget's table. In the tet al.Small pieces of the liver parenchyma were fixed in 2.5% glutaraldehyde for 24 hours. The small pieces were washed by phosphate buffer . Postfixation was made in 1% osmium tetroxide buffered to pH 7.4 with 0.1 M phosphate buffer at 4°C for 1-2 h and then washed again in phosphate buffer to remove the excess fixative. The samples were dehydrated through ascending grades of ethanol followed by clearing in propylene oxide. The specimens were embedded in araldite. Polymerization was obtained by placing the capsules at 60°C. Ultrathin sections (100 nm) were prepared using ultramicrotome and picked up on uncoated copper grids. Following double staining with uranyl acetate and lead citrate, sections were examined and photographed using a JEOL 100 Cx transmission electron microscope, Japan.et al,[Malondialdehyde (MDA) was determined and measured according to the method of Yoshioka et al, using a et al, Data weret al, Data werOn electron microscope examination of the sections from the rat liver of the control group showed a hepatocyte with mitochondria with prominent cristae, plenty of rough endoplasmic reticulum and a nucleus that was surrounded by a nuclear membrane with chromatin masses and a nucleolus . The mitThe fine structure from rats receiving amiodarone drug showed degenerated hepatocytes with many vacuoles and damaged nuclear chromatin . The mitOn electron microscopic study of a section in the hepatocytes from rats received amiodarone and vitamin E showed rounded nuclei with intact nuclear envelope, chromatin masses, nucleolus and minimal lipid droplet . The hepP < 0.001).There was a significant increase in plasma MDA in group II as compared to group I , (P < 0.P > 0.05).There was a nonsignificant increase in plasma MDA in the group III as compared with group I , (P > 0.P < 0.001).There was a significant increase in plasma MDA in the group III as compared with group II , (P < 0.P < 0.001).Analysis of variance (F-Test) showed a significant difference between the studied groups , (P < 0.et al,[Amiodarone is a lipophilic antiarrhythmic/antianginal drug which is able to influence the physicochemical status of biological lipid components. Since oxidation of lipids is affected by their physicochemical state and amiodarone binds to lipoprotein. Lapenna et al, hypotheset al,[et al,[et al,[The fine structure of the hepatocytes from the rats that received amiodarone drug showed a degenerated hepatocyte with many vacuoles with damaged nuclear chromatin. These necrotic hepatocytes with disrupted cytoplasm and a large number of pathological organelles suggest the occurrence of amiodarone toxicity. Membranoet al, demonstrl,[et al, showed pl,[et al, illustraet al,[et al,[The mitochondria showed deposits and many lipid droplets. These intramitochondrial lipids are characterized by the lack of limiting membrane, amorphous appearance, a medium to high density, and a rounded or irregular form. In additet al, concludel,[et al, demonstret al,[In our study, the Kupffer cells were destructed with the blood sinusoids that were found to be fragmented. This is in accordance with the study of Ireton who founet al, revealedIn the present investigation, the electron microscopic study of a section in the liver from rats received amiodarone and vitamin-E showed a rounded nucleus with an intact nuclear envelope, chromatin masses, nucleolus and minimal lipid droplets. The hepatocytes of the same group revealed an intact rough endoplasmic reticulum but the mitochondria were still damaged without deposits. In addition, the hepatocytes showed a normal bile canalicului with normal microvilli and intact junctional complexes. The blood sinusoid of the hepatocytes was intact with a healthy Kupffer cell. The nuclei of the hepatocytes were intact and surrounded by a nuclear envelope and chromatin masses plus nucleolus were also shown. Vitamin E served to improve the antioxidant defense system.et al,[et al,[It has been demonstrated by several authors that antioxidants, such as vitamin-E27 and thet al, suggesteet al, Bansal el,[et al, showed tIn conclusion, our study shows that vitamin-E co-administration with amiodarone led to lesser histologic changes in the parenchyma of rat liver, suggesting that vitamin-E pretreatment may play a role in the amelioration of side effects of amiodarone.


We report a rare case of Alport syndrome with progressive posterior lenticonus. A 24-year-old male presented to our tertiary eye care center with history of poor vision. At initial presentation, the patient had bilateral anterior lenticonus, posterior subcapsular cataract, and renal failure. The patient was diagnosed with Alport syndrome based on a positive family history of the disease and clinical findings. Further examination revealed progressive posterior lenticonus that was not present initially. The presence of such finding is important because it influences the surgical approach to avoid complications during cataract surgery. Alport syndrome is a rare clinical entity characterized by the familial occurrence of hemorrhagic nephritis and sensorineural deafness Alport 1927). Alport syndrome has a prevalence of 1/5000, with 85% of affected individuals having the X-linked form, where the affected males develop renal failure and usually have high-tone sensorineural deafness by the age of 20. The typical ocular signs are dot-and-fleck retinopathy, which occurs in 85% of the affected adult males, anterior lenticonus, which occurs in about 25%, and rare posterior polymorphous corneal dystrophy.927. AlpoA 24-year-old male presented to our tertiary eye care hospital complaining of cloudy vision bilaterally since childhood, with the right eye affected more than the left. The patient had long-standing episodes of hematuria and was on renal dialysis for chronic renal failure at the time of initial presentation. In addition, the patient had reported difficulty in hearing.+1 in the right eye and 20/60+1 in the left eye. The patient’s manifest refraction was –2.50 –0.25 × 80 in the right eye and –2.50 –2.50 × 95 in the left eye. Intraocular pressure was normal bilaterally. Slit lamp examination of the right eye was within normal limits except for advanced anterior lenticonus, and fleck retinopathy was present on fundus examination [Ocular examination revealed best corrected visual acuity of 20/80mination . The lefmination . The diamination . ProgresSome authors have considered anterior lenticonus as a manifestation of Alport syndrome, whereas posterior lenticonus is not associated with systemic disease.6et al.et al.et al.et al.The ocular and clinical features of Alport syndrome are identical in both the X-linked and autosomal recessive forms. Retinopathy and cataracts are the only ocular abnormalities described in the rare autosomal dominant form of Alport syndrome.The X-linked mutations have been mapped to defects in the α-5-chain of the type IV collagen gene, compromising the COL4A5, COL4A3, and COL4A4 genes. All mutations lead to abnormalities in the basement membrane of the glomerulus, cochlea, retina, lens capsule, and cornea, which eventually contribute to the typical phenotype of Alport syndrome.10et al.et al.,et al.,et al.et al.μm).As Alport syndrome represents a mutation coding for collagen type IV, the lens capsule is considerably thinner. Junk et al.et al.et al.19et al.et al.et al.23The presence of cataract, either as a component of the disease or as a side effect of oral steroids following renal transplant, together with a fragile capsule makes cataract surgery more challenging. Phacoemulsification has been reported as a safe procedure in such cases. Zare In conclusion, Alport syndrome affects multiple systems, including the eye. The ocular manifestations are important to recognize in order to determine the proper medical and surgical therapy. Posterior lenticonus, which was once considered as an isolated manifestation is being reported more frequently in association with Alport syndrome, suggesting that posterior lenticonus is part of the disease.


Ovarian tissue cryopreservation and transplantation have been considered as promising means of fertility preservation for women who have survived cancer, with livebirths being reported from this technique. Ovarian tissue cryopreservation can be offered to patients with different types of cancer. Among the cryoprotectants, glycerol appears to give the poorest results. The techniques of cryopreserving ovarian tissue and alternative approaches have been reviewed in this article. The readers are reminded that this technique is still experimental and informed consent to be obtained from patients after counseling with medical information on the risks involved. Advances in chemotherapy and radiotherapy have increased the survival rate of cancer patients, amazingly up to 90% for young cancer patients. Studies in the US have shown that by 2010, one in 200 individuals will be a survivor of childhood cancer.[Recovery of ovarian function after anticancer treatment is very much affected by the loss of follicles due to chemo- or radiotherapy, resultinin vitro maturation (IVM) followed by cryopreservation. Alternatively, oocytes could be isolated and cryopreserved from ovarian tissue biopsy or the whole ovary. If the patient had a partner, these oocytes could be fertilized after IVM and the resulting embryos could be frozen.[Fertility of female cancer patients could be preserved by various means. The ovaries may be transposed under peritoneum (oophoropexy) to protect them from pelvic irradiation. However,e frozen.6 Howeveret al.[The ovary has hundreds of primordial follicles containing immature oocytes which are smaller, dormant, less differentiated and without zona. Such immet al. have shoet al.[Ovarian tissue cryopreservation has been practised since the early 1950s. Parrot1 showed tet al. reportedet al. and rabbet al. These suet al.[Roughly three decades after Parrot's study, reports et al. showed tet al.[Newton et al. obtainedet al.[in vitro cultures of cryopreserved ovarian tissue were viable up to 10–15 days. In vivo restoration of ovarian function after cryopreservation and autologous transplantation of ovarian cortex in human beings was first documented by Oktay and Karilkaya.[et al.[in vitro and ICSI was performed, it did not fertilize. Later in 2004, normal embryonic development was reported by the same group in oocytes retrieved from frozen-thawed ovarian cortical strips transplanted beneath the abdominal skin of a breast cancer patient.[Hovatta et al. further arilkaya. This orta.[et al. reported patient.et al.[in vitro fertilization in a modified natural cycle after the transplantation of cryopreserved ovarian tissue also resulted in livebirth.[The first livebirth from frozen-thawed ovarian cortex after autologous orthotopic transplantation was reported by a Belgian group led by Donnez. Ovarian et al. had replet al. Pregnancivebirth. These liPotential indications for ovarian tissue cryopreservation have been listed by various authors.–26 Patie2532in vitro maturation with recombinant FSH and LH. ICSI was performed on three mature oocytes using her husband's sperm while two were fertilized normally. These fertilized eggs cleaved into good quality four-cell embryos which were frozen as the patient had to complete her therapy.[At our center, we approached fertility preservation for a married, ovarian cancer patient, in a different way. She underwent oophorectomy after which the ovary was sent to the IVF lab. Six immature oocytes were collected from visible follicles and subjected to  therapy. To the b therapy. This app therapy.35 with eMedium to transport tissue to the labet al.[2 incubator until slicing of the tissue was completed.[It is well known that ovarian cortex has hundreds of primordial and growing follicles. Therefore, only ovarian cortex is required for ovarian tissue cryopreservation. Ovarian cortex may be obtained using different surgical techniques as described by various reports mentioned above. The ovarian cortex should be delivered in a suitable medium to the cryopreservation lab. Leibovitz L-15 (Life Technologies) medium has been used by various authors according to the method described by Gosden et al. to transet al. The tranet al. HEPES-buompleted. However,ompleted. to transompleted. kept theRemoval of stromal tissue before slicing the cortex is considered to be important to reduce the thickness of the tissue to be frozen. Presence of stromal tissue may impair the permeation of the cryoprotectant into the ovarian cortex, thereby, resulting in poor or reduced survival rates of the follicles.–40 The t2228Cryoprotectant and dehydration time are major factors in the cryopreservation of any tissue. DMSO, propanediol (PROH), ethylene glycol (EG) and glycerol have been used by various authors as cryoprotectants to cryopreserve ovarian tissue. Although PROH is the popular cryoprotectant to freeze early cleavage embryos, DMSO also appears to be widely used in ovarian tissue cryopreservation. Survival of primordial follicles was the poorest after freezing and thawing with glycerol as the cryoprotectant compared to DMSO, PROH and EG. EG has get al.[363840Initially, cryopreservation protocols for ovarian tissue did not have sugar in the cryoprotective medium.15 Additiet al. observedet al.36384041vs two) does not seem to make much difference although Gook et al.[No standard dehydration time or duration of incubation of ovarian tissue in the cryoprotective medium has been found in the literature; the duration varies from 15 to 90 min.1538–40 G15Most of the studies have used the Planer programmable freezer to cryopreserve human ovarian tissue. Protocols using DMSO or EG start freezing at 0°C while those using PROH start near room temperature. Seeding temperature also varies among the studies from -6°C to -9°C although most of the studies seed at -8°C. The program is similar in most of the reports with a cooling rate of -2°C/min to the seeding temperature followed by -0.3°C/min to -30°C (or -50°C) and finally, -50°C/min to -140 to -150°C141538 followet al.[et al.[et al.[et al.[Thawing of frozen ovarian tissue also varies in the published reports. Newton et al. applied et al. Gook et l.[et al. have alsl.[et al. have thal.[et al. The frozl.[et al. in whichet al.[The pregnancies and livebirths reported from human ovarian cryopreservation and transplantation resulted from slow freezing of ovarian tissue. Gook et al. have docet al. Vitrificet al. However,et al. Vitrificet al.,[Orthotopic and heterotopic sites were studied for transplantation of frozen-thawed ovarian tissue. The existing menopausal ovary has been the popular site in orthotopic transplantation studies.222339 Al2223et al., noted wiet al.,19in vitro maturationCollection of oocytes and in vitro maturation.[in vitro matured oocytes could be fertilized by ICSI and the resulting embryos could be frozen.[6An alternative means of fertility preservation is feasible in addition to ovarian tissue cryopreservation. Fresh ovarian cortex may be transplanted to monozygotic twins who are discordant for ovarian failure.33 Immatuturation.49 On thee frozen.640 This Cryopreservation of the whole ovary has been attempted as an alternative to ovarian cortical slices as these slices suffer from loss of follicles mainly from ischemic damage and sometimes due to cryoinjury.50 Transp51et al.[The account given so far clearly shows that ovarian tissue cryopreservation is still experimental, although pregnancies from this technique have been reported. Therefore, the patient should be counseled thoroughly that this technique is purely experimental and that the risk of reintroducing cancerous cells, although very rare, is not ruled out. Parents should be given available information and future prospects on ovarian tissue cryopreservation if the patient is a minor. Using the tissue is entirely left to the option of minor patients when they enter adulthood, as starting a family is their choice. Getting informed consent after conveying the relevant medical information explaining the risks and uncertainties would help adult patients and parents of minor patients to avail the technique of ovarian tissue cryopreservation. The article by Van Den Broecke et al. is recomOvarian tissue cryopreservation is a promising mean of fertility preservation. Although spontaneous pregnancies from ovarian tissue cryopreservation and transplantation have been reported, the technique is still considered to be experimental. The source of pregnancy after ovarian tissue transplantation from ovarian transplants or the recovered existing menopausal ovary is still unclear, although evidence is in favor of transplants. Cryopreservation of the intact ovary and concerns about ethical issues related to this technique have to be explored further.


To the Editor: Burckhardt et al. (Clostridium difficile–associated disease (CDAD) in Saxony, Germany. In contrast to the observation by Wilcox and Fawley in the United Kingdom  as did other infectious gastroenteritides   . Thus, a


The explanation is multifactorial, determined by the complex interactions between the tumor and its microenvironment, the virus, and the host immune response. This review focuses on discussion of the obstacles that oncolytic virotherapy faces and recent advances made to overcome them, with particular reference to adenoviruses.Targeted therapy of cancer using oncolytic viruses has generated much interest over the past few years in the light of the limited efficacy and side effects of standard cancer therapeutics for advanced disease. In 2006, the world witnessed the first government-approved oncolytic virus for the treatment of head and neck cancer. It has been known for many years that viruses have the ability to replicate in and lyse cancer cells. Although encouraging results have been demonstrated  Although treatments for the disease have improved significantly, conventional chemotherapy or radiotherapy still have limited effects against many forms of cancer, not to mention a plethora of treatment-related side effects. This situation signifies a need for novel therapeutic strategies, and one such approach is the use of viruses. The ability of viruses to kill cancer cells has been recognized for more than a century . They acThe term ‘oncolytic viruses’ applies to viruses that are able to replicate specifically in and destroy tumor cells, and this property is either inherent or genetically-engineered. Inherently tumor-selective viruses can specifically target cancer by exploiting the very same cellular aberrations that occur in these cells, such as surface attachment receptors, activated Ras and Akt, and the defective interferon (IFN) pathway . Some viet al. [More recently, gene silencing by RNA interference technology has been utilized to confer tumor selectivity. MicroRNAs (miRNAs) or small interfering RNAs (siRNAs) regulate gene expression post-transcriptionally by translation block or cleavage of specific, complementary mRNA via the RNA-induced silencing complex (RISC). By inserting a complementary sequence next to a critical viral gene, it is possible to confine virus replication to tumor but not normal cells that express high levels of the corresponding miRNA. This has been demonstrated by several groups –38. Gürlet al.  developedl1520  is an oncolytic Ad2/Ad5 hybrid with deletion of its E1B 55K and E3B genes. The E1B 55K protein is involved in p53 inhibition, viral mRNA transport and host cell protein synthesis shut-off [E1B 55K and E3B genes. A recent finding by Thomas et al. [dl1520 was less efficient in lysing cells infected in the G1 phase of the cell cycle due to a reduced rate of late viral protein synthesis, and this appears to be a result of the adenoviral gene product encoded by open reading frame 1 of early region 4 (E4orf1). As such there is a need to increase the potency of these viruses by identifying mutations that result in tumor selectivity but not those that result in attenuated virus replication and oncolysis. Since the first generation of replication-selective Ads was tested in pre-clinical experiments and clinical trials, several advances have been made to improve potency by dissecting the functions of different genes of Ad.Gene-manipulated oncolytic viruses such as Ad, herpes virus and vaccinia virus are being developed as a new class of anti-tumoral agent ,40,41. Sshut-off  , was unable to replicate in quiescent normal cells but was able to do so in cancer cells with defective G1-to-S checkpoint. This virus has demonstrated superior anti-tumoral activity in vivo compared to dl1520 after intratumoral and intravenous injections [E1B 19K deletion (dl250) was significantly reduced in normal cells secondary to rapid apoptosis induction in the presence of tumor necrosis factor-α (TNF-α), whilst the opposite occurred in cancer cells due to multiple defects in the apoptotic pathways  [dl1520 and wild-type Ad2. E1B 19K-deleted Ad5-infected cancer cells also expressed lower levels of EGFR and anti-apoptotic proteins [The adenoviral ost cell . E1A norjections , althougjections ,52, adenjections –55 and ajections . Replicaression)   was able to selectively target Epstein-Barr virus (EBV)-associated tumors such as Burkitt’s lymphoma and nasopharyngeal carcinoma [dl331 to enable the synthesis of viral proteins. Interestingly, anti-tumoral efficacy in vitro and in vivo was superior to wild-type Ad5 and this might be the result of PKR-induced apoptosis, increased IFN-β production, and the adenoviral E3B gene deletion.Ads also produce the virus-associated (VA) RNAs. These are RNA polymerase III transcripts that, amongst other functions, are obligatory for efficient translation of viral and cellular mRNAs by blocking the double-stranded RNA-activated protein kinase (PKR) ,59, a naarcinoma . This isE3 region could also affect its oncolytic potency. These include the E3 11.6K (or adenovirus death protein – ADP), which facilitates late cytolysis of infected cells and release of progeny viruses [E3B and E3 gp19K genes on the potency of oncolytic adenovirus will be discussed later.Gene products encoded by the adenoviral  viruses . Ads tha viruses ,62. The TP53 gene that was approved in 2004 by China’s State Food and Drug Administration for the treatment of head and neck cancer [E1A gene deletion) is that infectivity is limited to only one cycle. In contrast, oncolytic viruses can replicate and spread in cancer cells resulting in longer transgene expression. Together with tumor lysis this would lead to better therapeutic efficacy. Arming oncolytic viruses with anti-cancer genes has been a major focus in cancer virotherapy, and transgenes exploited include tumor suppressor, pro-apoptotic, anti-angiogenic, “suicide”, and immunomodulatory genes.The discovery of the genetic basis of malignancy has in part promoted the development of cancer gene therapy, which involves the introduction of exogenous nucleic acid to restore, express or inhibit a particular gene of interest. Viruses are at present the most efficient gene delivery system. A well-known example is Gendicine , an Ad5 vector encoding the human k cancer . AlthougINK4A-armed oncolytic Ad, which has shown good inhibition of gastric tumor xenografts [et al. [E1A gene is regulated by the human telomerase reverse transcriptase (hTERT) promoter and hypoxia response element, together with p53 under the strong cytomegalovirus (CMV) promoter. This virus showed tumor selectivity with efficient p53 expression and oncolysis. Nonetheless, targeting a single gene is unlikely to have a major impact on survival, given that in cancer a large number of genetic alterations affect only a core set of signaling pathways and processes, as has been recently described for pancreatic cancer [1, as studied by Hu et al. [et al. [et al. [et al. [in vivo. A reciprocal approach is to ablate the function of oncogenes post-transcriptionally by arming oncolytic Ad with small hairpin RNA (shRNA). Recent work includes those targeting hTERT [in vitro and in vivo.Like Gendicine, oncolytic viruses could be armed with tumor suppressor or pro-apoptotic genes that are frequently lost in cancer. One example is by the use of p16nografts . Wang et [et al.  developec cancer . Hence tu et al. . Anti-tu [et al.  and Chen [et al.  utilized [et al.  treated ng hTERT , Ki-67 [ng hTERT , Surviving hTERT , and Apong hTERT , all of et al. [E1 genes are under the control of the hTERT promoter, could stimulate peripheral blood mononuclear cells (PBMCs) to produce IFN-γ that has anti-angiogenic properties, resulting in reduced tumor vascularity and slowed growth in immunocompetent mice. However, Kurozumi et al. [et al. [The tumor microenvironment plays a critical role in promoting malignant cell growth and progression, as well as restricting virus spread. One important issue is tumor angiogenesis. A recent finding by Ikeda et al.  suggestei et al.  also shoi et al. . Recent i et al. –80, intei et al. ,82, cansi et al. , and trii et al. , as welli et al.  and vasci et al. ,87. Kang [et al.  made use [et al. ,90.E1B 55K deletion, ADP overexpression and CD/TK fusion gene expression is currently in a phase III trial in combination with radiotherapy for patients with prostate cancer.Gene-directed prodrug activation therapy (or suicide gene therapy) involves the delivery of a gene that would lead to the expression of an enzyme, followed by the administration of a prodrug that is activated selectively by this enzyme. One example is the HSV thymidine kinase (HSV-TK)-ganciclovir method, whereby HSK-TV is able to monophosphorylate ganciclovir, which is subsequently converted by cellular kinases to the triphosphorylated forms, blocking DNA synthesis and inducing cell death. Most publications have described the use of replication-deficient viruses with this approach, but recent studies that demonstrated its efficacy using replication-selective oncolytic Ads include treatment for prostate , gallblaet al. [et al. [in vivo. Induction of cancer cell death with an apoptosis-inducing agent prior to injection of oncolytic HSV could also produce channels for effective virus spread [et al. [Viruses are naturally larger than other anti-cancer agents such as chemicals and antibodies . After intratumoral injection, effective virus spread could be impaired by the extracellular matrix, areas of fibrosis and necrosis, and surrounding normal cells in the tumor bed, although Kolodkin-Gal et al.  found th [et al.  studied s spread . Elevates spread . Injecte [et al.  examined [et al. . Hypoxia [et al. ,104. In  [et al.  or HSV [ [et al. ,107.et al. [et al. [in situ tumors and tumor xenografts. These receptors are trapped in the tight junctions and therefore not accessible to the virus. However, Ads that use receptor X  could induce epithelial-mesenchymal transition and result in efficient oncolysis.For viruses that have reached the immediate vicinity of the tumor, cellular genetic changes could prevent successful virus entry into the cells. For cellular entry of most Ads , they must first bind to the Coxsackie and adenovirus receptor (CAR) on the surface membrane via the knob portions of their fibers, followed by internalization mediated by the viral penton proteins and cellular integrins. CAR is ubiquitously expressed in epithelial cells, but its expression is often downregulated in many cancer types due to activation of the Raf-MAPK pathway . Recent et al. . They alet al. . Strauss [et al.  showed tCIP1/WAF normally inhibits cyclin-dependent kinase 2 (CDK2)  by p21CIP1/WAF, whereby SET and PCNA normally increase viral DNA replication. In the case of vaccinia virus, recent work has suggested that cells with activated c-Jun NH2-terminal kinase (JNK) signaling cascade could activate PKR   and bloc  and warfarin treatment (to inhibit vitamin K-dependent coagulation factors) and found that this approach significantly increased the anti-tumoral effect of systemically delivered oncolytic Ad5 in nude mice [After intravenous delivery the liver, part of the reticuloendothelial system, is the predominant site of Ad5 sequestration with significant hepatocyte transduction ,172. Ad5et al.  showed tet al.  or otheret al. ,122. As ude mice . Good reude mice  or by geude mice  for liveet al. [in vivo. Shashkova et al. [P) gene product from wild-type MV, an IFN antagonist, has been found to exhibit reduced IFN sensitivity and better oncolytic potency in vivo [in vivo [A plethora of immunostimulatory genes have been inserted into the genome of oncolytic viruses with the aim of stimulating effective anti-tumoral immune responses. Recent examples include the heat shock proteins ,180, cheet al.  utilizeda et al.  used a f in vivo . A recom[in vivo . The expet al. [et al. [et al. [et al. [et al. [et al. [Antigen-specific activation and proliferation of lymphocytes are regulated by interaction of the peptide-antigen-major histocompatibility complex (MHC) with the T cell receptor, as well as both positive and negative signals from co-stimulatory molecules expressed on antigen-presenting cells (APCs). The most important of the APCs are the DCs. DCs are capable of capturing antigens secreted or shed by tumor cells and upon maturation, present the peptides to T cells. Endo et al.  showed t [et al.  and Rama [et al.  demonstr [et al.  used ano [et al.  revealed [et al.  utilizedE3 region of the adenoviral genome is divided into E3A  and E3B  and is involved in immune response evasion and virus release from cells. Because it is dispensable, this region is frequently deleted in many adenoviral mutants to provide more space for therapeutic gene insertion, although recent work has suggested that transgene expression was higher if gene was inserted at regions other than E3, such as L3 [E3B region, however, could attenuate the virus oncolytic potency by increasing macrophage infiltration and expression of TNF and IFN-γ [E3 gp19K whilst retaining other E3 regions [The ch as L3 . Deletiond IFN-γ ,133. Pot regions . In addi regions , gp19K i regions ,202. CTLThe field of oncolytic virotherapy is expanding and viruses continue to hold promise as effective treatments in combination with chemotherapy or other therapeutic modalities. As continuing work is being done to improve the currently available oncolytic viruses, novel viral species are also emerging and worth exploring, for example the porcine Seneca Valley virus , myxoma


Sir,et al.[et al.[et al.,[et al with ‘comma sign’. Few more predisposing conditions in addition to those mentioned by the authors are diabetes mellitus, mixed connective tissue disease, and hypothyroidism. Various new techniques, such as water jet, Dormia basket, polypectomy snare, Nd:YAG laser, Bezotome and modified lithotripter, have been developed to treat the bezoars with variable success rates. After removal, prevention of recurrence is important. Prophylactic oral enzyme andprokinetic along with psychotherapy and regular follow up may help in preventing recurrence.[We read the article entitled “Giant trichobezoar of duodenojejunal flexure: A rare entity” with intet al. and Dinyl.[et al. The male.[et al., had a hacurrence.


Surgical correction of aortic coarctation (AC) was concurrently introduced by Crafoord and Nylin, Gross anP > 0.05). The complication rates (9.9% vs. 8.5%) and mortality rates (0.7% vs. 2.5%) were also not different (P = 0.05 to 0.1).Despite an initial report of poor results, subseque15The conclusion for native ACs was “the question remains not can it be done, but should it be done?,” whereas the conclusion for post-surgical aortic recoarctation was “... balloon angioplasty for relief of residual or recurrent aortic coarctation offers an acceptable alternative to repeat surgical repair” despite the fact that results were similar or even better for native AC. I questioned this interpretation stating 20While treatment of native AC by balloon angioplasty was initially controversial,1719‐24 i1722et al.et al.[etl.[et al. Brodsky,l.[et al. Cooper[3l.[et al. and Suarl.[et al. had repol.[et al.33 in thal.[et al.33 Finalll.[et al. did not l.[et al. and Rao[l.[et al. from ourl.[et al. used traIndications for balloon angioplasty are similar to those used for surgical intervention: Significant hypertension and/or congestive heart failure. While the controversy over routine use of balloon angioplasty in treatment of neonatal and infant coarctations continues, it may certainly be utilized in special circumstances, namely, 28Potential for arterial damage exists, especially in neonates and young children. Therefore, use of umbilical artery approach in neonates‐38 and aThe diameter of the balloon selected for angioplasty should be carefully chosen. Small balloons do not produce adequate relief of obstruction and large balloons may produce aortic rupture or aneurysm formation. Initial balloon dilatation is performed with a balloon whose diameter is an average of aortic isthmus or transverse aortic arch and descending aorta at the level of diaphragm. If there is no adequate relief of obstruction (i.e. gradient <20 mmHg) and angiographic improvement, repeat dilatation at the same sitting with a balloon as large as the diameter of the descending aorta at the level of diaphragm should be undertaken. It is exTips of guide wires or catheters should not be manipulated over the freshly dilated coarctation segment to avoid aortic perforation. A guide Evaluation of arterial insufficiency and limb growth retardation in a groStenotic vascular lesions can be dilated by balloon angioplasty. However, the elastic recoil of the vessel wall may return the vessel lumen to the pre-dilatation diameter following removal of the balloon catheter. Such recoil and vascular dissection, if any, following balloon dilatation can be circumvented with implantation of endovascular stents. Additional principles of stent management, historical aspects of stent development, types of stents, technique of stent deployment and results of stent therapy will not be reviewed here because of limits of space. The interested reader is referred elsewhere44 for fuet al.[Because of growth issues and the need for large sheaths for stent implantation, most cardiologists limit stent usage to adolescents and adults, although a few have advocated their use in younger children.‐48 Even et al. indeed pet al.51 or groet al. should bet al. larger cet al.In summary, the paper by Francis and associates which describes the utility of transcatheter intervention in neonates and young infants with critical coarctation of the aorta and left ventricular dysfunction, re-emphasizes prior reports advocating such approaches. Selection of site of entry for the procedure to minimize arterial damage, use of appropriate size balloon for angioplasty, avoiding manipulation of tips of catheters/guide wires across the freshly dilated coarctation segment, and incorporation of some method of evaluation of femoral artery sufficiency at the time of follow-up of the primary cardiac defect are germane to the success of the procedure. Avoiding use of stents in neonates and small infants and/or developing alternative strategies such as biodegradable stents or growth stents is recommended.


Idiopathic pulmonary fibrosis (IPF) remains exactly that. The disease originates from an unknown cause, and little is known about the mechanisms of pathogenesis. While the disease is likely multi-factorial, evidence is accumulating to implicate viruses as co-factors (either as initiating or exacerbating agents) of fibrotic lung disease. This review summarizes the available clinical and experimental observations that form the basis for the hypothesis that viral infections may augment fibrotic responses. We review the data suggesting a link between hepatitis C virus, adenovirus, human cytomegalovirus and, in particular, the Epstein-Barr gammaherpesvirus, in IPF. In addition, we highlight the recent associations made between gammaherpesvirus infection and lung fibrosis in horses and discuss the various murine models that have been used to investigate the contribution of gammaherpesviruses to fibrotic progression. We review the work demonstrating that gammaherpesvirus infection of Th2-biased mice leads to multi-organ fibrosis and highlight studies showing that gammaherpesviral infections of mice either pre- or post-fibrotic challenge can augment the development of fibrosis. Finally, we discuss potential mechanisms whereby viral infections may amplify the development of fibrosis. While none of these studies prove causality, we believe the evidence suggests that viral infections should be considered as potential initiators or exacerbating agents in at least some cases of IPF and thereby justify further study. Idiopathic pulmonary fibrosis (IPF) is a progressive interstitial lung disease that severely compromises pulmonary function . IPF likFibrotic lung disease likely results from an inciting injurious event within the lung. Although the precise temporal sequence of events and mechanisms of disease are not understood, several common pathobiological characteristics are recognized. These include damage and loss of type I alveolar epithelial cells followed by hyperplastic expansion of type II cells ; variablDespite ongoing research driven by the need for therapy, the initiating or injurious agents are unknown, and it is not understood why the fibrosis is dysregulated and progressive . It is let al. [Two studies have suggested a link between infection with the hepatitis C virus (HCV) and IPF. HCV is a small, enveloped, positive-sense single-stranded RNA virus in the Flavivirus family . Replicaet al.  were ablet al. . In a coet al. . One poset al. . Given tet al. [in situ hybridization for the adenovirus gene product E1A. E1A DNA was present in 3 out of 19 (16%) cases of IPF, in 5 of 10 (50%) cases of interstitial pneumonia associated with collagen vascular disease, and in 2 of 20 (10%) cases of sarcoidosis [et al. found that the incidence of E1A DNA was considerably higher in patients who had been treated with corticosteroids (67%) compared to those patients left untreated (10%). This finding raises the interesting possibility that corticosteroids, a common therapy for IPF, may make patients more susceptible to adenovirus infection or reactivation from latency. However, studies investigating the titer of anti-adenoviral IgG in IPF patients have failed to demonstrate an elevation above normal [Human adenoviruses have been suggested as etiological co-factors in the progression of interstitial lung disease -39. Adenet al.  examinedcoidosis . While te normal . Despitee normal . This meIt is also conceivable that adenovirus infections could serve as exacerbating agents for patients with established lung fibrosis, although it is difficult to determine the frequency of this happening from published clinical literature. Furthermore, recent studies using an animal model of fluorescein isothiocyante (FITC)-induced fibrosis were unable to demonstrate significant exacerbation of FITC-fibrosis within the first 7 days post-mouse adenoviral infection . One notet al. [et al. [et al. [Human cytomegalovirus (HCMV), a betaherpesvirus, is a widespread opportunistic pathogen that persists in healthy individuals but normally only causes clinical manifestations in immune-compromised individuals . HCMV inet al.  studied et al. . Also, t [et al.  did note [et al. , HCMV Ig [et al. . Despiteet al. [The virus that has been associated most strongly with IPF is EBV. EBV is a gammaherpesvirus that is present in all populations, infecting more than 95% of humans within the first decades of life . An assoet al.  sought tet al. [et al. [A couple of studies have associated the presence of active and latent EBV markers with IPF. Kelly et al.  investig [et al.  then detet al. [et al. [It should be noted that not all studies have found an association between EBV and IPF. In 1997, Wangoo et al.  publishe [et al.  failed tet al. [Although EBV had been detected with more frequency in the lungs of IPF patients than in the lungs of control patients in most previous studies, many members of each IPF cohort analyzed did not test positive for EBV infection at all. Tang et al.  went on et al. drew other conclusions from their study that suggest susceptibility to viral infection and IPF depends on a genetic or acquired predisposition. Co-infection occurred more frequently in patients with the sporadic form of IPF compared to those with the familial form. Familial IPF is characterized by the incidence of IPF in two or more members of an immediate family [et al. note that the increased frequency of HHV-8 in the lungs of the IPF cohort is particularly interesting. In the United States, HHV-8 infection is predominantly found in patients with HIV infection and Kaposi's sarcoma [Tang e family . This le sarcoma , and allCollectively, the analyses of IPF lung tissue chronicled above create a rationale to study the association between viral infections and the occurrence of IPF, but do not provide evidence for a causal relationship between viruses and IPF. Demonstrating causation in humans requires detection of a virus in the lungs prior to clinical manifestations of IPF  or evidence that an anti-viral therapy confers anti-fibrotic effects. The latter has been attempted with some success in a limited number of case studies, but no large trials have been conducted to date ,57. WhilPulmonary fibrosis has been reported to occur in both cats and horses -62. InteMurine models of pulmonary fibrosis have enabled identification of pathogenic cells and mediators that are believed to be important in human fibrotic disease, and they have facilitated further exploration of a pathogenic role for viruses in humans . The humet al. [et al. proposed that a viral infection made the previously protected lungs susceptible to fibrotic disease upon the event of an exogenous injury. These results are enticing, but it should be noted that the bleomycin was delivered during the peak of lytic viral infection. It is difficult to infer from these studies whether chronic latent infection with MHV-68 might also predispose the lung to subsequent fibrotic responses. Also, the mechanism(s) for how MHV-68 infection augmented the subsequent fibrotic response to bleomycin were not defined. This is an area of active research in our laboratory. We have determined that MHV-68 infection is latent in the lung by day 14 post-infection [In 2002, Lok et al.  used MHVnfection . Mice giet al. [Ebrahimi et al.  showed tet al. -75. The et al. . This stet al. [et al. [et al. [et al. [et al. [et al. MHV-68 has previously been reported to cause vascular damage [et al. [Mora et al.  extended [et al.  publishe [et al. , and Mor [et al.  detected [et al. , who pro [et al.  speculat [et al. . Similarr damage . Finally [et al.  noted en [et al. .et al. [et al. [The authors attribute some of the TGF-β1 dysregulation to epithelial cell damage. Interestingly, type II alveolar cells are a target of MHV-68, and Mora et al.  speculatet al. . Furtheret al. ,83. Flan [et al.  have rep [et al. ,85. Tablet al. [While most IPF patients have a slow, progressive disease, some patients have an acute deterioration in function that carries a poor prognosis. In the placebo arm of a study of 32 patients who died from IPF-related causes, Martinez et al.  reportedet al. . This fiet al. . In theset al. [The recruitment of fibrocytes to the lung was also associated with viral exacerbation of FITC-induced fibrosis . Fibrocyet al.  when theet al. [et al. [The studies with MHV-68 discussed here can only suggest that similar human viruses found in the lungs of IPF patients have a pathogenic role in fibrosis. Given that fibrosis in humans is progressive, it seems important to better understand the chronic reactivation that can occur during herpesviral infections. It is possible that repeated activation may lead to repeated rounds of epithelial cell damage, cytokine release and fibrocyte recruitment. Additionally, it will be important to determine whether long-term latent MHV-68 infection of naïve mice augments the production of profibrotic factors and whether the same is true in EBV-infected human lungs. A latent infection does not appear to create a Th2 bias equal to that of IFN-γR-/- mice, but any bias may predispose a latently infected individual to a fibrotic trigger from an unrelated factor. It will also be helpful to more carefully study the cell types that harbor long-standing viral infection because the prolonged injury caused to such a cell type is likely responsible for increasing susceptibility to fibrosis. Flano et al.  found th [et al. ,91. As vThe authors declare that they have no competing interests.KMV performed literature searches and wrote the bulk of the review. BBM reviewed and edited the article for content and clarity.


The discovery of a family of membrane water channel proteins called aquaporins, and the finding that aquaporin 1 was located in the choroid plexus, has prompted interest in the role of aquaporins in cerebrospinal fluid (CSF) production and consequently hydrocephalus. While the role of aquaporin 1 in choroidal CSF production has been demonstrated, the relevance of aquaporin 1 to the pathophysiology of hydrocephalus remains debated. This has been further hampered by the lack of a non-toxic specific pharmacological blocking agent for aquaporin 1. In recent times aquaporin 4, the most abundant aquaporin within the brain itself, which has also been shown to have a role in brain water physiology and relevance to brain oedema in trauma and tumours, has become an alternative focus of attention for hydrocephalus research. This review summarises current knowledge and concepts in relation to aquaporins, specifically aquaporin 1 and 4, and hydrocephalus. It also examines the relevance of aquaporins as potential therapeutic targets in hydrocephalus and other CSF circulation disorders. Aquaporins are a family of integral membrane proteins that function as water channels. The existence of such water channels had been postulated for some time as the passage of water across certain membranes is too rapid to be explained on the basis of diffusion through plasma membranes . The ideet al. . AQ. AQ+/K+ ithelium  but it iet al. [Understanding the response of AQP1 to changes in CSF pressure and, in particular hydrocephalus, is important for determining a possible therapeutic potential. If AQP1 expression was to be significantly down-regulated in hydrocephalus, its therapeutic potential would be limited. However, if it remained unchanged or even were increased then pharmacological blockade might result in a therapeutically beneficial reduction in CSF production. Mao et al.  examinedet al, unpublished data). We have found that AQP1 protein is unchanged compared to saline injected controls at 3 and 5 days post-injection of kaolin using Western Blot analysis of choroid plexus tissue. AQP1 mRNA levels were lower in hydrocephalic mice at 3 days post-kaolin injection but unchanged compared to saline-injected controls at 5 days post-kaolin. There is no clear explanation for this finding. In may be a reflection of an early and temporary reduction in AQP1 transcription in response to hydrocephalus. This needs to be clarified by further studies in other models of hydrocephalus.We have studied AQP1 expression and localisation in the choroid plexus of hydrocephalic adult mice using a cisternal kaolin injection model . Nicchia et al.  questionu et al.  reported [et al.  using a  [et al. -48.The lAQP4 is the most abundant and widespread aquaporin in the brain and occurs in a short isoform  and a long isoform . AQP4 foThe role of AQP4 in handling brain water and therefore brain oedema has been demonstrated in several pathologies including cerebral tumours, traumatic brain injury, cerebral ischaemia or stroke and brain abscess . In AQP4et al. [et al. [et al. [There are some conflicting reports in the AQP4-null phenotype in relation to ventricular size and CSF dynamics. Manley et al.  reported [et al.  reported [et al.  reportedet al. [et al. [The main role of AQP4 in hydrocephalus appears to be as a compensatory mechanism. Mao et al.  reported [et al.  found thet al. [Using a communicating model of hydrocephalus secondary to subarachnoid inflammation after intraparenchymal injection of L-α-lysophosphatidylcholine (LPC) stearoyl, Tourdias et al.  also repet al. [The finding of increased AQP4 expression in various models of hydrocephalus has been interpreted as a compensatory mechanism to allow for transependymal/parenchymal CSF absorption. Such adaption may be a mechanism that allows for the development of compensated or arrested hydrocephalus. This hypothesis was tested by Bloch et al.  who studet al. .et al. [et al. [There is a small but consistent rate of spontaneous hydrocephalus in AQP4-null mice that has been reported by several groups. Feng et al.  reported [et al. found thaet al. [et al. [According to Feng et al. , mice th [et al. . Regionaet al. [et al. [The regulation of AQP4 may be categorised in a similar manner to that of AQP1 and was recently reviewed by Yukutake and Yasui  and prevet al. . AQP4 haet al. -66. Howe [et al.  recently [et al.  while ph [et al. ,70). Theet al. [B receptor agonist and vasoconstrictor peptide, resulted in down-regulation of AQP4 in rat brain.There is also some evidence for regulation of the overall level of AQP4. As for AQP1, the tonicity of cellular environment may be important for AQP4. Zeng et al.  demonstret al. . Intereset al.  also recet al. [Xenopus laevis oocytes which is mediated by the V1a receptor. This resulted in decreased water permeability. The effect was reduced with mutation of Ser180; phosphorylation which has already been reported to decrease water permeability [Localisation of AQP4, particularly in the astrocytic end feet is important for function as discussed above. A recent study suggests that trafficking of AQP4 may be used as a regulatory mechanism for AQP4. Moeller et al.  found theability . This ph2+ and other mercurial compounds but these are toxic [2+ [et al. [2+. Tetraethylammonium (TEA) was also suggested as an AQP1 inhibitor [Determining the importance of AQP1 and 4 in hydrocephalus and CSF production would be facilitated by the availability of a non-toxic specific AQP1 or 4 blocking agents. Identifying such an AQP1 blocker remains a challenge . It is kre toxic . As mentoxic [2+ . However [et al.  have sugnhibitor  althoughnhibitor . Corticonhibitor , sheep fnhibitor  as well nhibitor ,81. Thernhibitor ,82.et al. [Xenopus laevis oocytes expressing AQP1, and the same group reported similar findings in a swelling assay using human embryonic kidney (HEK292) cells expressing pEGFP/AQP1 [et al. [et al. found no evidence that acetazolamide inhibits AQP1 or 4 [Xenopus laevis oocyte osmotic permeability assay, Sorgaard & Zeuthen [et al. [Arylsulfonamides, including acetazolamide, a carbonic anhydrase inhibitor that is commonly used to reduce CSF production in the management of pseudotumor cerebri and other clinical situations, have been suggested as pharmacological blockers of AQP1 and 4. This has generated considerable controversy. Ma et al.  reportedGFP/AQP1 . Using t [et al.  reported [et al. ,87 had sQP1 or 4 ,88. In a Zeuthen  found no [et al.  who also [et al. ,87,91 coet al. [A small inhibitory effect of bumetamide, a loop diuretic that blocks the Na-K-Cl co-transporter, on AQP4 water permeability  has leadet al.  to blockApart from pharmacological blockade of AQP1, there are several other potential routes to modulation of AQP 1 expression, none of which have thus far been explored. These include methods to increase AQP1 degradation or reduction of AQP1 expression/transcription. Although our knowledge of the mechanisms and pathways underlying choroidal AQP1 regulation is lacking there are possible techniques that may be employed to increase AQP1 degradation. This includes the intraventricular administration of AQP1 antibodies which could potentially result in AQP1 internalisation and degradation, thus temporarily reducing CSF production. Further understanding the mechanisms through which AQP1 is internalised, as we have observed in our studies of choroidal AQP1 in hydrocephalic mice, may provide additional useful information to allow these pathways to be manipulated.in vivo, or gene therapy, is another potential tool for modulating AQP1 and thus CSF production. A small interfering RNA (siRNA) against AQP1 has been used by Boassa et al. [et al. [et al. [AQP1 transcription. The 5' region of AQP1 has multiple binding sites for TTF-1 the expression of which is also seen in the choroid plexus. Intraventricular injection of antisense TTF-1 oligodeoxynucleotide in rats resulted in a reduction of AQP1 mRNA and protein in the choroid plexus. These rats also had an increased survival compared to controls after water intoxification.AQP1 knockdown a et al.  to studya et al. . Splinte [et al.  has used [et al.  reportedAquaporin 1 makes a substantial contribution to CSF production and is a potential therapeutic target in the management of CSF circulation disorders. Aquaporin 4 is important in brain water homoeostasis and consequentially in conditions involving both cytotoxic and vasogenic oedema. In hydrocephalus AQP4 has a protective effect by allowing resorption of transependymal CSF into brain capillaries. There is considerable scope for improving our understanding of aquaporins in relation to CSF physiology in health and in diseases such as hydrocephalus. The ultimate potential of aquaporin modulators in the management of these conditions and others remains to be determined. Continued study of aquaporins in hydrocephalus and other conditions is needed.The authors declare that they have no competing interests.All authors contributed to the writing of this review. All authors have read and approved the final version of the manuscript.


Pediatric urolithiasis poses a technical challenge to the urologist. A review of the recent literature on the subject was performed to highlight the various treatment modalities in the management of pediatric stones. A Medline search was used to identify manuscripts dealing with management options such as percutaneous nephrolithotomy, shock wave lithotripsy, ureteroscopy and cystolithotripsy in pediatric stone diseases. We also share our experience on the subject.2 and proximal non-impacted ureteric stone less than 1 cm with normal renal function, no infection and favorable anatomy. Indications for PCNL in children are large burden stone more than 2cm or more than 150mm2 with or without hydronephrosis, urosepsis and renal insufficiency, more than 1cm impacted upper ureteric stone, failure of SWL and significant volume of residual stones after open surgery. Shock wave lithotripsy can be offered for more soft (< 900 HU on CT scan) renal stones between 1-2cm. Primary vesical stone more than 1cm can be tackled with percutaneous cystolithomy or open cystolithotomy. Open renal stone surgery can be done for renal stones with associated structural abnormalities, large burden infective and staghorn stones, large impacted proximal ureteric stone. The role of laparoscopic surgery for stone disease in children still needs to be explored.Shock wave lithotripsy should be the treatment modality for renal stone less than 1cm or < 150 mm Urinary lithiasis affects between 5-10% of the humans during their lifetime, 2-3% of them are children.[Management options for renal calculi are similar to those for adults. The majority of the stone disease in children can be managed with SWL, PCNL or a combination of treatment modalities. Open surgery is currently indicated in a few select cases. It is important to understand the effect of each treatment modality on the growth of the kidney. Stone location, composition, size; anatomy of collecting system; and presence of obstruction/infection are important factors in selecting the modality.2, soft renal stones (HU< 900 mm2 on CT scan) between 1 to 2 cm with normal renal function, no infection and favorable anatomy. However, the efficacy, need for ancillary procedures and treatment-related complications are not clearly defined as in the adult population. The theoretical long-term safety and bio effects of SWL on renal function and growth are debatable. Brinkman et al.,[et al.,[et al.,[Shock wave lithotripsy is currently the procedure of choice for treating most urinary stones in children. Shock wave lithotripsy should be the treatment modality for all renal stones less than 1 cm or < 150 mmn et al., noted no,[et al., noted thet al.,[et al.,[Important considerations in SWL are stone burden, composition and ability of the distal urinary tract to successfully pass the fragments. Children pass stone fragments well and do not require stenting routinely. Newman et al., reported,[et al., reported,[et al.,et al.,[Brinkman et al., reviewedet al.,et al.,[et al.,[Shock wave lithotripsy outcome for lower calyceal stones varies with lower pole anatomy. Tan et al., showed t,[et al., did not et al.,[et al.,[Management of pediatric staghorn calculus is technically challenging to the urologist. Al- Busaidy et al., found th,[et al., found thet al.,[et al.,[The cumulative risk of recurrence is higher in children as compared to adults. Afshar et al., reported,[et al., have alsShock wave lithotripsy is well tolerated with minimal morbidity. Minor complications such as bruising, ecchymosis and renal colic are reported in 11–50% cases. Authors treating large stone burdens have a reported steinstrasse rate of 1.9-5.4%.18 IncideWe have performed SWL in 53 children (with a mean age of 6.2 + 4.4 years) using Dornier compact delta lithotripter . General anesthesia was given to all pediatric patients at the start of SWL. Both ultrasound and fluoroscopy were used to localize and monitor the fragmentation. Shocks were started at Level one (10 kilovolts) and progressed to Level two (11.5 kilovolts) after 100 shocks. The intensity was increased to higher levels only if the desired fragmentation was not visible with fluoroscopy and ultrasound. In children, the power settings rarely exceeded Level three (12.75 kilovolts). The shocks were given at a frequency of 60. Procedure was terminated after complete fragmentation was noted on fluoroscopy and ultrasound. Number of shocks given never exceeded 1500. The mean stone length was 1.09 + 0.4 cm. The mean shocks required per session were 982 + 492. The mean intensity of the shocks was 11.81 + 0.5 kilovolts. The mean number of sessions required was 1.09 + 0.3. Adequate fragmentation was achieved in all. We feel that complete clearance should be achieved with minimal number of shocks, energy and need for ancillary procedures. Clinically insignificant residual fragments (CIRF) can be a source of recurrent stone formation and hence not considered as success. Overall complete clearance was achieved in 42 (79.2%) renal units at the end of three months. Seven (13.2%) patients had CIRF which was being conservatively followed. Ancillary procedures were required in four (7.5%) renal units, which included PCNL in three and ureteroscopy in one child.Since the first pediatric series reported by Woodside and associates in 1985,[et al.,[et al.,[et al.,[Studies demonstrate minimal scarring and insignificant loss of renal function after PCNL. Dawaba eet al., reported,[et al., showed t,[et al., also shoet al.,[et al.,[Improvement in technology and miniaturization of instruments, with availability of more efficient energy sources for intracorporeal lithotripsy has revolutionized endourological procedures in children. Helal et al., reported,[et al., describeWith the availability of holmium-Yttrium Almunium Garnet (Ho: YAG) laser, smaller pneumatic lithoclast and ultrasound probes, PCNL can be performed using smaller nephroscopes. We designed a smaller lithoclast probe with suction for use through a pediatric nephroscope and found it highly effective and safe in children. Various studies have demonstrated the safety of Ho: YAG laser in children. Ultrasound-guided puncture is a good alternative to fluoroscopy and has the advantage of avoiding radiation and preventing visceral injury.et al.,[Complications are similar to adults. Intraoperative bleeding requiring blood transfusion, injury to the pelvicaliceal system and sepsis are major concerns with PCNL in children. Kroovand et al., proposed3 (range: 94-989) with 130 complex calculi. In our earlier published data the stone clearance rate was 89.8%. With ancillary procedures (SWL), stone clearance increased to 96% at three months.[Indications for PCNL in children are similar to those in adults and include large burden stone more than 2cm, hard renal stone (> 900HU on CT scan) between 1 to 2cm, significant renal obstruction, urinary infection, failure of SWL and significant volume of residual stones after open surgery. We have performed PCNL in 222 renal units in children (mean age 8.9 ± 3.9 years) from 1997 till date. Mean stone bulk was 335.6±122.6 mme months. For chile months. [Figure e months..Percutaneous nephrolithotomy and SWL are safe and efficacious in managing pediatric stones of 1-2cm; however, the choice should be tailored to the three-dimensional stone size and composition, using 3-D CT scan. When we Recurrence is a major problem as follow-up is not assured due to poor socioeconomics. In this scenario, SWL has higher retreatment rates requiring more ancillary procedures, thus defeating the purpose of giving the patient complete stone clearance with minimal morbidity and a single hospital stay. However,et al.,[et al.[Laparoscopic renal surgery is still not widely performed by pediatric urologists due to higher operative time, logistic support, lack of indications and sufficient surgeon experience. Laparoscopic retroperitoneal surgery has a definite role in the management of patients requiring open surgery for calculus disease but indications in pediatric patients are not well defined. Casale et al., reported.,[et al. successfet al.,[Van savage et al., noted thet al.[et al.,[Stone-free rates with SWL vary from 75-100% depending on the size of the stone. Landau et al. found th.[et al., found siWith the advent of smaller instruments and laser lithotripsy, URS for management of pediatric urolithiasis has become more common. With the availability of 4.5 and 6Fr semi-rigid ureteroscopes and a 6.9Fr flexible ureterorenoscope with Ho: YAG laser energy source, instrument-related complications are uncommon. Ho-YAG laser fibers are small and flexible with a short depth of penetration (0.4 mm), allowing it to be used safely with pediatric endoscopes. Further, laser fragmentation produces 2-3 mm fragments that can pass very easily down the ureter. Most series have employed ureteral stent placement, following ureteroscopic lithotripsy in pediatric patients. We reported successful use of supine antegrade flexible ureteroscopy in treating impacted upper ureteric calculi in a six-year-old pediatric patient.et al.,[et al.,[It has been shown that ureteral dilatation does not increase the risk of stricture and significant vesicoureteric reflux (VUR). Caione et al., reported,[et al., have sho,[et al.,40 The mo,[et al.,Ureteroscopy may provide more efficient stone clearance and hence should be preferred for distal ureteral stones, larger stones and impacted stones. We have performed URS in 86 patients . Ureteroscopy was possible with 6Fr semi-rigid ureteroscope in 81 while 6.8/7.5Fr flexible ureteroscope was used in five patients. Seventy-two (83.7%) patients had mid or lower ureteric stones and 14 (16.2%) patients had upper ureteric stones. Foty-eight (55.8%) patients required ureteric dilatation. Double J stent was placed postoperatively in 36 (41.8%). The procedure was successfully completed in all except one who required simultaneous antegrade flexible URS. Mean hospital stay was three days.Vesical stones in the pediatric age group in India, often present with a large stone burden. Vesical calculi can be managed by transurethral or percutaneous suprapubic lithotripsy. In children, especially in boys, because of the small caliber penile urethra and concerns about iatrogenic urethral stricture, transurethral cystolithotripsy may be more difficult. It is safe if stone burden is less than 1cm. Percutaneous cystolithotomy (PCCL) is a safe alternative with low morbidity and complication rate for large burden vesical stone.–45 PercuWe have performed 81 bladder stone surgeries between 1995 and 2006. The mean age of the patients was 6.4 ± 2.3 years, range 1-15 years. The surgeries performed were cystolithotripsy (n=60), PCCL (n=13) and open cystolithotomy (n=8). We have used pneumatic, ultrasound and laser energy for stone fragmentation. In the pediatric age group (less than five years), a 7.5Fr ureteroscope/pediatric cystoscope was used.Sometimes small stones migrate from the upper urinary tract into the bladder and then are ejected out per urethra with the urinary stream. Infrequently, during passage through the urethra the calculus gets impacted even when there is no distal organic obstruction. The management of such recently impacted calculus varies according to the site and nature of the calculus. The methods to deal with the situation are to bring out the stone by forward milking or external urethrotomy if situated in the anterior urethra. The former procedure is quite traumatizing to the urethral wall and should be restricted to only smooth contour stone in presence of non-obstructed urethra. External urethrotomy even as a primary procedure is best avoided in penile urethra. Stone can also be removed with gentle pulling with artery forceps if lodged at the submeatus under proper anesthesia. In the case of posterior urethral stone, push back by applying vigorous per urethral xylocaine jelly and single attempt of per urethral catheterization(PUC) is worth trying. If unsuccessful, it is advisable to do suprapubic cystostomy (SPC) to prevent further urethral damage. After initial decompression of bladder with PUC / SPC, later endoscopic removal of the stone can be undertaken.et al.,[et al.,[et al., compared the efficacy of open cystolithomy and cystolitholapaxy in pediatric patients with primary bladder stones. The operative time was similar in the two groups. The hospital stay was significantly less after endourologic procedures than after open surgery. However, there were significantly more complications in the endourologic procedures.[Open stone surgery should be offered in situations where it is at least a viable and reasonable alternative to less invasive modalities. The pros and cons of the treatment should be explained in an unbiased manner to the attendants to effectively perform and implement this form of treatment if chosen. Sakkas eet al., estimateet al., The pooret al., Zargoosh,[et al., reported,[et al., Open surocedures.Pediatric urolithiasis poses a technical challenge to the urologist. Aims of the management should be complete clearance of stones, preservation of renal function and prevention of recurrence. Despite the consensus of SWL being the initial treatment of choice for most stones in pediatric patients, there are certain indications for other modalities as well. With improvement in instrumentation and technology, endoscopic management has become safe and effective. Percutaneous nephrolithotomy and SWL are safe and efficacious in managing pediatric stones of 1-2cm. Indications for PCNL in children are large stone burden, significant renal obstruction and renal infection. Ureteroscopy provides efficient stone clearance in mid and lower ureteric stones. Transurethral cystolithotripsy is generally avoided in pediatric patients, but is feasible in single vesical stone less than 1cm. Percutaneous cystolithotomy or open cystolithotomy is generally the alternative for pediatric vesical stones.


The European Regional Office of the World Health Organization  recently dramatically lowered its former  recommendations for cumulative aircraft noise exposure levels associated with risks of adverse public health effects. WHO’s recommendations, although lacking the force of law, are nonetheless of interest to aviation regulatory bodies and to the public at large. It is therefore important that WHO’s recent recommendations receive and withstand careful scrutiny. WHO’s (2018) recommendations are based on controversial assumptions, analyses and interpretations prepared by Guski et al. (2017). Gjestland (2018) identified a number of limitations of the opinions expressed by Guski et al. (2017). Guski et al. (2019) subsequently challenged some of Gjestland’s (2018) observations. This paper responds to the defenses offered by Guski et al. (2019) of the opinions expressed in their prior (2017) publication. The European Regional Office of the World Health Organization  recentlyLden = 45 dB to prevent adverse public health consequences. WHO’s newly identified noise exposure levels are an order of magnitude lower than those identified by WHO in 2000. WHO’s 2000 recommendations were not source-specific recommendations, but suggested a limit of LpA,16h = 55 dB to avoid health effects mediated by serious annoyance. The corresponding Lden value would have been higher for a full 24- (rather than 16-h) day period. A source-specific correction for aircraft, however, would have moved WHO’s recommendation in the opposite direction. WHO’s new [Lden = 45 dB from LpA,16h = 55 dB) represents “half as much noise” as WHO’s prior recommendation. This is a dramatic shift in the recommended “safe” limit on aircraft noise exposure, for which strong and reliable evidence is essential.WHO  stronglyGjestland’s  criticalGuski et al.  state thdn factors” are commonly referred to as “non-acoustic” , inter alia.Univariate regression  accounts for only about one third of the variance of individual annoyance responses. The prevalence of high annoyance in communities is also influenced by additional acoustic and non-acoustic factors, however. Acoustic factors include maximum levels, number of flights, fleet composition, and their respective distributions over time. Each of these factors also include errors of measurement and/or prediction. Non-acoustic factors include personal noise sensitivity and attitudes toward the noise source. In the aviation industry all “non- LThe latter (non-acoustic) factors are essentially useless for regulatory purposes, however, since they are unknown in advance, and cannot be used for a priori predictions of annoyance prevalence rates. Further, aircraft fly over all members of a community, not just those who may be more or less individually sensitive to aircraft noise exposure. As long as the preferred measure of community response to aircraft noise is the prevalence of a consequential degree of annoyance, non-acoustic influences on annoyance are simply free variables that contribute to errors of prediction. CTL analysis estimates the net effects of non-acoustic influences on annoyance in the aggregate, and by treating them systematically as deviations from an assumed growth rate of annoyance.den -based factors) may explain up to 33% of the variance, while the other two-thirds are explained by non-acoustic factors.” Guski et al. [Gjestland  commentsi et al.  insist tGjestland  notes inGjestland  identifiOne of the inclusion criteria for the meta-analysis of Guski et al.  was “stuThe annoyance questions of most modern noise surveys comply with ICBEN  recommenTo avoid known and unknown biases, the opinions of each and every member of a target population must have an equal probability of representation in social survey findings. This is commonly provided by random selection of a current and exhaustive list of the target population compiled into a sample frame. Examination of the sampling methods of the HYENA study at Heathrow reveal disturbing deviations from EPSEM  sampling. Eligible residents were contacted by mail by researchers at Imperial College. They received an information pack that requested their participation. At the same time a letter from HACAN, a noise interest group at Heathrow, was sent to its members and other voluntary organizations, urging them to participate in the survey. A follow-up letter is not uncommon in a mail survey but urging members of a select group , invites bias. HACAN’s letter further solicits self-selection for participation in the study as follows: “If you have not received an information pack….and would be interested in taking part, please contact .” See . EncouraLAeq 24h = 11 dB (Stockholm) and LAeq 24h = 22 dB (Milan). Such aircraft noise levels are only marginally credible as modeling estimates, much less as acoustic measurements. Guski et al. [Lden by applying a correction factor of 2.6414 dB [Likewise, there is reason to question the adequacy of the exposure estimates at several of the HYENA airports. Babisch et al. cite aircraft noise levels as low as .6414 dB . These vx-axis) by a community-specific annoyance decision criterion, expressed directly in units of decibels [CTL analysis assumes that the rate of growth of annoyance with transportation noise exposure is fully controlled by the duration-adjusted loudness of the exposure. This growth function is anchored to the noise-axis (decibels . CTL anae(−A/m) prediction laterally along the abscissa displays different segments of the ogival growth function that do not appear parallel when pinned at different exposure values to the abscissa.) Their disbelief is further conditioned on their view that univariate logistic regression is some form of gold standard for the derivation of exposure-effect relationships.The meta-analysis of Guski et al.  complete2. 2 for the CTL function and the polynomial regression functions preferred by Guski et al.A closer look at the actual response data reveals a different picture. Response data expressed as pairs of % HA and noise level have been found for all the surveys in the WHO full dataset except for the 2002 Amsterdam survey by Breugelmans et al. The results from these surveys are plotted in the panels of The comments by Guski et al.  do not iAs has been shown in Gjestland’s original paper , and fur