Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
septic shock is consistently the most common causative factor identified for acute kidney injury ( aki ) in critical illness , and has been associated with nearly 50% of cases internationally . despite advances in our understanding of the pathophysiology of septic aki ,
treatment aimed at reversing or preventing septic aki remains primarily based on supportive haemodynamic management . in the previous issue of critical care , legrand and colleagues examine the association between haemodynamic targets of resuscitation ( cardiac output , mean or diastolic blood pressure , central venous pressure ( cvp ) and central venous oxygen saturation ) and development or persistence of aki in a single centre study of patients with septic shock admitted to a surgical icu .
the authors found that only higher cvp and low diastolic blood pressure were associated with increased risk of development of new aki , or persistence of renal dysfunction present at icu admission . in these patients
importantly , the association between cvp and aki remained when potentially confounding effects of positive fluid balance and higher positive end - expiratory pressure were accounted for in a multivariable analysis .
so , a 5  mmhg increase in cvp predicted 2.7-fold odds of new or persistent aki .
furthermore , when the association between different levels of mean cvp and aki was examined in a non - parametric logistic regression , there was a trend for higher cvp to be associated with worse renal outcome for all levels of cvp from 4  mmhg upward , so that a cvp of 15  mmhg was associated with an approximately 80% risk of new or persistent aki , compared to approximately 30% at a cvp of 6  mmhg .
these findings are important because current surviving sepsis campaign guidelines recommend fluid resuscitation of patients with sepsis - induced tissue hypoperfusion to target a cvp of 8 to 12  mmhg ( or 12 to 15  mmhg in mechanically ventilated patients ) within 6 hours of presentation . in patients with sepsis - induced hypotension
the rationale for cvp targeted fluid resuscitation is to ensure ' adequate cardiac preload and hence maintain cardiac output and organ perfusion .
however , absolute levels or changes in cvp poorly predict cardiovascular response as sepsis - induced hypotension is multi - factorial , related to changes in myocardial performance , vascular tone , regional blood flow distribution , venous reservoir capacity and capillary permeability . in contrast
, elevated cvp will cause a direct and predictable increase of renal venous pressure that , experimentally , has been associated with elevated renal interstitial and intra - tubular pressure .
resultant renal venous congestion can reduce renal blood flow ( lower trans - renal pressure gradient ) and decrease the pressure gradient for ultrafiltration ( higher intra - tubular pressure ) . in septic shock ,
. aggressive fluid resuscitation beyond reversal of hypovolaemia to arbitrary cvp targets could result in increased venous congestion without substantial benefit to forward renal perfusion , thus predisposing to renal dysfunction .
the association between elevated cvp and renal dysfunction has been made previously in the setting of chronic cardiac failure .
now legrand and colleagues have provided evidence that such an association is observed in septic shock and its treatment .
their findings are also in accord with secondary analysis of the vasopressin in septic shock trial , which reported that a more positive fluid balance and elevated cvp were associated with increased mortality in patients with septic shock even when accounting for differences in baseline illness severity and demographics .
although these observational findings are hypothesis - generating rather than confirmatory , they add weight to the literature suggesting the adverse effects of fluid overload in critical illness and aki in particular , effects that may be mediated in part by venous congestion causing impaired organ function .
it is now important to determine whether uncritical pursuit of cvp targets such as those advocated by the surviving sepsis campaign might , in some patients , add insult to sepsis - induced organ injury .
prospective data are required to evaluate the true contribution of raised venous pressure to renal and other organ dysfunction and to determine better endpoints for fluid resuscitation in sepsis .
rajkumar rajendram bsc mbbs mrcp frca fficm , specialty registrar in anaesthesia , royal free hospital , london .
john r prowle ma msc md mrcp fficm , consultant in renal medicine and intensive care , the royal london hospital , london .

Answer:
in critical illness , septic shock is a contributing factor in nearly half of all cases of acute kidney injury ( aki ) .
 traditional approaches to prevention of organ dysfunction in early sepsis have focused on prevention of hypoperfusion by optimisation of systemic haemodynamics , primarily by fluid resuscitation .
 fluid administration to a target central venous pressure ( cvp ) of 8 to 12  mmhg ( 12 to 15  mmhg in mechanically ventilated patients ) is currently recommended for the early resuscitation of septic shock .
 however , in the previous issue of critical care , legrand and colleagues report that higher cvp in the first 24 hours of icu admission with septic shock was associated with increased risk for development or persistence of aki over the next 5 days .
 this study highlights a potential association between venous congestion and the development of septic aki , suggesting that cvp - targeted fluid resuscitation in septic shock might not be beneficial for renal function .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
the fda - approved da vinci surgical system is a novel approach to perform minimally invasive surgery and is considered a  second revolution  in surgery after the introduction of laparoscopic surgery .
this system was introduced in april 2003 at our institution , with 90 pediatric patients undergoing a variety of procedures performed by our surgical group . among these procedures ,
several reports have been published on this subject , concluding that it is a feasible , safe alternative . despite some of its potential benefits
, there has yet to be any improvement shown by using the robot over the standard laparoscopic or open technique .
our objective in this study was to compare results using the robot system with that of laparoscopic and open techniques in our pediatric patients to determine the potential for acceptance as a standard approach in this population .
following irb approval , 150 charts of patients who underwent nissen procedures from 1994 to 2005 were divided into 3 treatment groups defined by technical approach , either robotic ( r ) ( n=50 ) , laparoscopic ( l ) ( n=50 ) , or open ( o ) ( n=50 ) .
groups were case - matched and performed by several surgeons and residents , under the care of one of the 3 staff surgeons at our facility .
the robot system used was the da vinci ( intuitive surgical , mountain view , ca , usa ) .
the fourth arm was used in a minority of pediatric patients due to the short distance between ports leading to the restricted movement of the working arms outside the patient .
we now use a 5-mm scope in addition to the 11-mm stereoscopic scope more typically used .
all cases were performed with the patient in a reverse trendelenburg position under general anesthesia and complete paralysis with an age - appropriate esophageal dilator in place .
port placement with the robot followed laparoscopic standards with the exception of ports being placed more distant to one another to allow broader external movements .
in open cases , unless the patient had a previous midline scar , a left subcostal incision was performed .
regardless of the surgical approach , once the equipment was inside the abdominal cavity , identical steps were taken to dissect the gastroesophageal junction and wrap the gastric fundus around the esophagus .
descriptive and analytical statistics were applied to compare surgical times , length of hospitalization , and outcomes using kruskal - wallis and tukey tests for continuous data and the chi - square text for nominal data .
in the 150 nissen cases included in this study , patients were younger and smaller in the open group ( 8555 months , 2417 kg , p<0.05 ) compared with those in the robotic ( 11764 months , 3723 kg ) and laparoscopic groups ( 10771 months , 3324 kg ) ( table 1 ) .
the most common indication for the procedure was reflux refractory to medical management either as the sole reason or associated with failure to thrive or neurological impairment , or both of these [ r = 39(78% ) , l = 50(100% ) , o = 34(68% ) ] .
other indications include a failed previous antireflux procedure , reflux associated with oromotor dysfunction , hiatal hernias , aspiration with an acute life - threatening event , and esophageal stricture .
robot operative times proved significantly longer compared with times for laparoscopic and open procedures ( r 16061 min , l = 107 + 31 min , o = 7327 min , p<0.05 ) .
the number of gastrostomy tubes done in addition to the nissen fundoplication in the robot group were similar to that of the other groups [ r = 17/50 ( 34% ) , l = 24/50 ( 48% ) , o = 11/50 ( 22% ) , p>0.05 ] .
the robot group experienced 2 conversions to the open approach ( 2/50 4% ) , comparable to the laparoscopic conversion rate ( 1/50 2% ) .
open cases resulted in longer hospitalization compared with the robot - assisted cases [ r = 2.944.5 d , o = 3.52.8 , p<0.05 ] .
complication rates were equivalent between groups , including hiatal hernia , tight wrap requiring dilatation , and wound infection [ r = 7(14% ) , l = 8(16% ) , o = 5(10% ) , p=0.387 ] . the most common complication with the da vinci and laparoscopic approaches was a tight wrap , requiring dilatation [ r = 4/50 , 8% and l = 3/50 , 6% ] , whereas in the open series , wound infections were more common ( 2/50 , 4% ) . on 30-day follow - up ,
the presence of transient symptoms including dysphagia , abdominal pain , feeding aversion , and gas bloating were equivalent [ r = 15 ( 30% ) , l = 14(28% ) , o = 6(12% ) , p=0.06 ] .
in our experience , the robot proved to be an acceptable approach for laparoscopic nissen fundoplication .
this parallels the findings reported on early experiences from other centers . as in previous randomized trials , our experience with nissen fundoplication shows comparable efficacy of the robotic and laparoscopic approaches , with similar morbidity . the laparoscopic procedure , whether da vinci assisted or not , demonstrated a slight reduction in hospital stay compared with the open technique .
patient demographics , surgical times , and complication rates according to surgical approach denotes significant difference between the robot vs. open group .
of the 2 robot cases that were converted to open , one was due to intraoperative hypotension and arrhythmia and the other due to difficult dissection following failed prior repair .
postoperatively , the presence of transient symptoms was similar between groups , reaching up to 30% .
there was a trend towards fewer symptoms in the open group that may be due to achieving a tighter wrap in the robot and laparoscopic groups leading to more gas bloating and abdominal complaints .
however , in long - term follow - up , all patients achieved symptomatic relief .
the learning curve for the da vinci system played a key role in our surgical times despite previous reports .
the 50 robotic cases in our study were distributed among the 3 surgical faculty and 4 pediatric surgery residents during this time .
in addition to this , the robot requires several extra steps to achieve assembly in a sterile fashion and to change the instruments .
we believe these factors combined would explain why the robot - assisted procedures resulted in both longer operative and total room times compared with the open series .
we expect reduced surgical times once the operating surgeons overcome this 10-case learning curve and reduced setup time as well with more practice and repetition of use . therefore , like others , we have found no proven outcome benefits of using the robot in low- or medium - difficulty cases compared with the laparoscopic approach .
potential benefits over standard laparoscopy include 3-dimensional image quality , camera steadiness , and the dexterity of the instrumentation for dissection and suturing .
to better delineate cases that benefit most from each one of the 3 techniques , randomized prospective trials utilizing surgeons past the learning curve is required .
robot - assisted surgery is equivalent to standard laparoscopic surgery in terms of complications and length of stay , with both having significantly increased operation times but reduced length of stay compared with open surgery .
improved results are expected once the learning curve is overcome . however , potential outcome benefits have yet to be proven .

Answer:
background : robot - assisted surgery must be evaluated before its acceptance as an option for standard therapy in the pediatric population .
 our objective is a comparison of results using the robot system with results for the laparoscopic and open approaches.methods:following irb approval , robot - assisted procedures were case - matched with controls , selected from 1994 to 2005 .
 data for 150 nissen cases were divided equally into 3 groups [ robot ( r ) , laparoscopic ( l ) , and open ( o ) ] , comparing surgical times , length of hospitalization , and outcomes.results:the average age ( r = 11764 months , l = 10771 months , o = 8555 months , p<0.05 ) and weight ( r = 3723 kg , l = 3324 kg , o = 2417 kg , p<0.05 ) of the open group were lower comparatively .
 robot operative times proved significantly longer compared with laparoscopic and open time ( r = 16061 min , l = 107 + 31 min , o = 7327 min , p<0.05 ) .
 the robot had 2 conversions ( 2/50 , 4% ) , comparable to the laparoscopic conversion rate ( 1/50 , 2% ) .
 open cases resulted in longer hospitalization [ r = 2.944.5 days , l = 3.547.8 days , o = 3.52.8 , p<0.05 ] .
 complication rates were equivalent between groups .
 the most common complication with the da vinci and laparoscopic approaches was tight wrap requiring dilation [ r = 4/50 ( 8% ) and l = 3/50 ( 6%)].conclusion : robot - assisted surgery is equivalent to standard laparoscopic surgery in terms of complications and length of stay , with both having significantly increased operation times but reduced length of stay compared with open surgery .
 further experience with this technology is needed to overcome the learning curve and reduce operative times .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
cannabis is a prominent political , health , and law enforcement issue in north america that is currently receiving a great deal of attention .
as we watch the effects of the legalization of cannabis in colorado , washington , alaska , oregon , and the district of columbia , other jurisdictions are debating the future of this illicit drug .
how can we prevent commercialization promoting increased rates of use within a legalization model ? where does marijuana for medical purposes fit into the picture , if at all ?
a critical piece of information often missing from these debates or not addressed adequately is the scientific evidence about the effects of cannabis use on a person 's overall health .
this concern is even more pressing when it comes to the cognitive , physical , and mental health harms to adolescents who use cannabis .
it is critical we ask these questions because adolescence is a time of rapid development that helps lay the foundation for success later in life .
conversely , it can also set the stage for experiencing challenges in adulthood , as youth are disproportionately more likely than adults to experience greater harms from drug use .
their brains are undergoing rapid and extensive development that can be negatively affected by cannabis use .
there is certainly cause for concern about the amount and frequency of cannabis use among youth . according to the 2014 monitoring the future ( mtf ) survey in the us , 35.1% of high school seniors reported pastyear use of cannabis , with 5.8% reporting daily or near daily use .
comparable prevalence rates are reported in canada , with 22% of 1519yearolds and 26% of 2024yearolds reporting pastyear use of cannabis in 2013 according to the canadian tobacco , alcohol and drugs survey . moreover
, a 2013 unicef report noted that canada 's youth are the highest users of cannabis when compared to students in other developed countries .
the mtf survey also indicates a growing perception among young people that cannabis is a relatively harmless drug , and there is strong evidence that perception of harm is inversely related to rates of use . knowing that youth are disproportionately heavy users of cannabis
, what specific concerns should this raise about short and longterm consequences and how do we incorporate these concerns in the debate ?
recent evidence shows that early and frequent use of cannabis has been linked with deficits in shortterm cognitive functioning , reduced iq , impaired school performance , and increased risk of leaving school early  all of which can have significant consequences on a young person 's life trajectory.1 of note , the impact of cannabis use on iq has been the topic of recent debate among experts in the field and further research aimed at understanding this relationship will provide much needed clarity .
heavy cannabis use in adolescence is also a risk factor for psychosis , a risk that is heightened if users have a preexisting vulnerability to that condition.1 cannabis use can also lead to dependence , with evidence from longitudinal studies in the us estimating the risk of developing cannabis dependence to be one in six among those users who initiated in adolescence,2 a rate higher than that reported among adults .
recent data from the 2012 canadian community health survey reveal that more than one in 20 young canadians aged 1524 met the criteria for cannabis abuse or dependence during the past year . there is also growing evidence from the human literature that early and frequent use of cannabis can alter structural aspects of the developing brain , including those that are responsible for memory , decisionmaking , and executive functioning.1 however , we do not yet know the full extent of the impact of early cannabis use on changes in brain function and behavior of young people , which underscores the need for further investment in research in this area . beyond longerterm consequences , cannabis can also acutely impair cognitive and motor functions like perception , coordination , and balance for hours after use .
this impairment presents a safety hazard for drivers getting behind the wheel , as well as for other motorists and pedestrians .
in fact , the risk of car crashes doubles for drivers who get behind the wheel after using cannabis and this risk is further elevated if cannabis use is combined with other substances , most notably alcohol .
recent data from the national fatality database indicate that cannabis was the most common illicit drug present among fatally injured drivers aged 1524 in canada between 2000 and 2010 .
the drug abuse warning network , which monitors the health impact of drugs in the us , estimated that in 2011 , there were nearly 456,000 drugrelated emergency department visits in which cannabis use was mentioned in the medical record .
data from the canadian institute for health information reveal that from 2006 to 2011 , youth aged 1524 spent the largest number of days in a hospital for a primary diagnosis of mental and behavioral disorders due to the use of cannabinoids . furthermore , the number of days spent in a hospital increased by almost 40% during the same time period.3
  these findings are particularly troubling because recent research from canada has revealed that young people are confused about cannabis and do not have the knowledge they need about the risks associated with this drug to make more informed decisions.4 some have expressed questionable beliefs about the effects of cannabis , indicating that it helps to improve their focus at school and can prevent  or even cure  cancer .
youth also expressed mixed beliefs as to whether cannabis improves or impairs driving performance , and felt that cannabis and driving was not as dangerous as drunk driving .
youth talked about how cannabis is natural and so they did not really think of it as a drug .
the findings from this reviewed research highlight the complexity of the issues surrounding youth consumption of cannabis . youth are confused with the mixed messages they are receiving from discussions ranging from legalization to the use of cannabis for medical purposes , which points to the need for a coordinated , comprehensive , factual , and consistent approach to increasing awareness of this drug and its impact .
as primary care is an important intervention point for youth experiencing harms related to cannabis , there is an urgent need to develop practical , evidenceinformed tools to assist healthcare providers in the early identification of cannabis use and cannabis dependence , as well as tools to deliver interventions to treat potential problems .
examples of such tools may include screening instruments to screen for cannabis use that warrants clinical intervention , as well as brief intervention strategies aimed at addressing the problematic substance use revealed during the screening process .
there is also an urgent need for further research aimed at improving the understanding of differences between the short and longterm effects of cannabis use , particularly on the developing adolescent brain .
such research should include mechanistic studies regarding alteration of cellular structure and function related to cannabis to determine the impact on adolescent brain development .
of particular concern are the impacts of the dramatic increase in concentrations of tetrahydrocannabinol ( thc ) , the main psychoactive ingredient of the cannabis plant , over the past 25 years .
the average potency of federally seized cannabis in the us has steadily increased from 3.5% in 1985 to 13.2% in 2012.5 in light of such an increase in potency , some historical findings about the health and developmental effects of cannabis use might not be relevant when trying to predict effects on contemporary users .
more research is also needed to shed light on the influence of cannabis policy on public health , public safety , and other outcomes .
the current understanding of the impact of cannabis policy on market forces , such as healthcare costs , lost productivity costs , and tax revenues , for example , is very limited , as is overall understanding of how perception , use , and outcomes interrelate around this drug . in an effort to help  clear the smoke ,  the canadian centre on substance abuse is currently undertaking a comprehensive review and synthesis of the literature on the effects of cannabis use during adolescence that will highlight key areas for action in policy , practice , and research
. this muchneeded work will provide clarity to misperceptions about cannabis , and make sense of some conflicting evidence about the effects of cannabis use and the impact of early or regular use during a time when the brain is still developing . by integrating neuroscience with the behavioral and social context of cannabis use by youth
, this report will provide a muchneeded resource for those working with youth and those involved in making decisions about policies , programs , or practices related to cannabis .
aj porathwaller has provided expert testimony at the standing committee on health 's ( hesa ) recent report on marijuana 's health risks and harms , october 2014 .

Answer:
cannabis is the most commonly used illicit substance among youth .
 recent policy developments and ongoing debate related to this drug underscore the urgent need to  clear the smoke  and better understand what the scientific evidence says about the health and behavioral effects of cannabis use , particularly on youth whose brains are undergoing rapid and extensive development .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
seizures are the most common neurological events of childhood with approximately 35% of children experiencing a seizure at some point in their lives 25% of whom subsequently go on to develop epilepsy .
the prevalence of epilepsy in india is 4.9 to 6.2 per 1000 population . of these patients with epilepsy , 43%
comprises of children and adolescents .  intractable epilepsy  is defined as a failure to respond to at least two antiepileptic drugs ( aeds ) given over at least a two - year period . a single definition for  intractable
 epilepsy can not suit all situations as definitions of intractability are individualized to the patient . of these patients
deemed to be intractable , approximately 50% are estimated to have surgically remediable epilepsy [ 4 , 5 ] .
 hemispheric epilepsy  ( he ) refers to epileptiform activity in all four lobes of one hemisphere , and when it involves more than two lobes of the brain , it is termed  subhemispheric epilepsy  ( she ) [ 4 , 6 , 7 ] .
these hemispheric brain lesions are commonly associated with early onset of catastrophic epilepsies and multiple seizure types that inhibit brain development .
these respond well to early hemispheric / subhemispheric disconnective / resective surgeries [ 69 ] .
an analysis was done of the pre- and postsurgical data of 34 children who underwent disconnective epilepsy surgeries , that is , a peri - insular hemispherotomy ( pih ) or a peri - insular posterior quadrantectomy ( pipq ) for hemispheric / subhemispheric epilepsy from april 2000 to march 2011 .
the hemisphere contralateral to the hemiparesis was shown by radiological ( mri / computerised tomography ( ct ) ) and functional ( scalp eeg / eeg video telemetry ) imaging to have a unilateral diffuse abnormality and the remaining hemisphere was normal . when the epileptogenic zone encompassed large areas of the temporal , parietal and occipital lobes with sparing of the frontal lobe
the decision was dependant on good concordance between the imaging ( mri , ct , nuclear studies ) , eeg , clinical and neuropsychological evaluations , and a clear localization of the lesion to the unilateral - affected region .
the indications for pipq were the same as for hemispheric epilepsy , the pathology being localized to involve the temporal , parietal , and occipital lobes .
the presence of residual voluntary motor function of the contralateral distal musculature , that is , finger opposition and foot tapping , was the indication for pipq preserving eloquent uninvolved sensorimotor cortex .
all patients went through a presurgical evaluation including a study of the seizure semiology , neurological examination , multiple electroencephalogram ( eeg ) examinations ( video telemetry ) , magnetic resonance imaging ( mri ) , and neuropsychological evaluation .
the focus of the evaluation was to identify a surgically remediable epilepsy syndrome with good electro - clinico - radiological concordance .
if the structural lesion responsible for epilepsy could be safely removed without causing deterioration in the functional status , the patient was considered for epilepsy surgery . however , if there was no concordance in investigations in the phase i evaluation , the patient would enter a phase ii evaluation which would include prolonged invasive eeg monitoring , nuclear medicine studies ( positron emission tomography ( pet ) and single photon emission computerized tomography ( spect ) ) , and a wada ( sodium amylobarbital ) test . however , none of our patients required a phase ii evaluation .
( figure 1 ) this is a surgical method of functional hemispherectomy that enables disconnection of the hemisphere through peri - insular windows requiring limited removal of the fronto - parieto - temporal opercular cortices . following the surgical principles of  anatomical subtotal removal of the hemisphere and complete disconnection ,
 the pih is a radical hemispheric tractotomy based on the concept of maximum disconnection with minimal excision .
it resulted from the demonstration that the hemisphere could be disconnected , made nonfunctional , through very small removal of brain tissue [ 9 , 14 , 15 ] .
a pipq was performed in all cases of subhemispheric epilepsy and the surgery tailored to encompass the whole epileptogenic lesion yet preserving the central region , which is still functional .
( figure 2 ) in this technical variant , there is a minimal removal of brain tissue but complete disconnection of the remaining major part of the abnormal cortex , which is left anatomically intact and viable by preservation of the arteries and veins irrigating these lobes . the primary motor and sensory cortices
are identified and recognized from the study of the mri and correlation with intraoperative surface anatomy , based on gyral pattern , arteries , and veins [ 6 , 7 ] .
the identification of the functional cortex is also aided by electrophysiological means under general anaesthesia before the disconnection .
this identification maximizes both the extent of resection and the safety of surgery [ 6 , 7 ] . in this variant
, the mesial temporal structures are resected , but the temporal neocortex is disconnected and not resected followed by a parieto - occipital disconnection [ 6 , 7 ] .
the data was analyzed with nonparametric tests because of the small sample size among the children with poor outcome following surgery ( engel 's class ii
nonparametric  square test and mann - whitney u test was were to compare the categorical and continuous variables between the groups .
p < 0.05 ( two tailed ) was considered significant and data was analyzed using spss ( version 19 ) .
the mean age of seizure onset was 3.8 years ( range : from neonates to 12 years ) .
the mean duration of epilepsy was 4 years ( range : from 3 months to 14 years ) .
28 children ( 82.3% ) had a seizure frequency of 2 episodes / day , while 11 ( 32.3% ) had at least one episode of status epilepticus prior to surgery .
epilepsy was due to rasmussen 's encephalitis ( re ; n = 11 ) ( figure 3 ) , infantile hemiplegia seizure syndrome ( ihss ; n = 12 ) ( figure 4 ) , hemimegalencephaly ( hm ; n = 3 ) ( figure 5 ) , sturge weber syndrome ( sws ; n = 4 ) ( figure 6 ) , and postencephalitic sequelae ( pes ; n
twenty - seven ( 79.4% ) patients underwent pih for lesions causing hemispheric epilepsy , and seven ( 20.6% ) underwent pipq for lesions causing subhemispheric epilepsy .
the seizure outcome after surgery was assessed by engel 's classification   and is described along with followup in table 1 .
we recorded 11 variables and analyzed them to arrive at predictive variables of a complete seizure freedom .
we found that age of seizure onset ( p = 0.03 ) and the etiology of the disease causing epilepsy ( p = 0.007 ) were predictive variables for the same .
patients who had re , sws , pes , and ihss had good seizure outcomes following surgery .
the results of our cognitive outcomes that have been published before   show that the mental and social age showed a steady increase after surgery .
however , in the long term , intelligence quotient ( iq ) showed only a gradual gain on followup .
older age of onset of seizures and a shorter duration of seizures prior to surgery were predictive of positive cognitive gains following surgery .
complications in this series included pseudomeningocele in 2 ( 5.8% ) and low pressure hydrocephalus in 1 ( 2.9% ) who required a low pressure ventriculoperitoneal shunt .
this is quite low as compared to other published series ( table 4 ) [ 911 ] .
we also had 15 patients who developed postoperative fever , but csf cultures were sterile .
this could have been due to an aseptic meningitis due to the presence of blood products in the disconnected cavity .
our series documents 91.1% seizure freedom , which is similar to other published studies [ 9 , 12 , 1621 ] . following functional hemispherectomy ,
seizure free outcomes have ranged from 52 to 90% [ 9 , 1621 ] . this range could be explained by differences in patient selection or technical pitfalls such as incomplete removal in anatomical hemispherectomy and incomplete disconnection in functional hemispherotomy [ 14 , 19 ] .
we found the age of seizure onset to be a strong predictor of seizure freedom ( table 2 ) .
this finding is also supported by other studies [ 3 , 22 , 23 ] .
a younger age of seizure onset is usually seen in children with developmental cortical malformations and multifocal epilepsy , which are proven to have poor seizure control .
the etiology of the disease producing epilepsy is also a strong predictor of seizure freedom ( table 3 ) .
the best results in our series were obtained in children suffering from re , sws , pes , and ihss ( table 3 ) .
ihss and sws are seen in the perinatal age group , and they are generally unilateral with complete sparing of the opposite side . there has been evidence to support that in such cases , early surgical intervention facilitates good seizure control and helps the uninvolved hemisphere to develop and take over the functions of both sides
. however , in one patient with ihss , we had a class ii seizure outcome and this was in the initial part of the series , which could be attributed to incomplete disconnection , and this patient was lost to follow up .
all patients with re had a class i seizure outcome as this disease also strictly affects only one hemisphere . however ,
the seizure outcome in patients with hm was not satisfactory as described in literature , and this has been reported in other series too [ 9 , 1721 ] .
the likely explanation could be the presence of migrational abnormalities in the so - called  preserved hemisphere  or early development of an epileptic encephalopathy , already in utero .
we found a significant gain in the mental and social age in the immediate postsurgical period which continued into the second and third years of followup .
our study   also showed that older age of onset of seizures showed positive mental and social age gains at followup .
onset of intractable epilepsy within the first 24 months of life is a significant risk factor for mental retardation , especially if seizures occur daily [ 12 , 24 ] .
most of these children have a low dq / iq to begin with and the improvement in cognitive skills after surgery is poorer in these children .
furthermore , our study   also showed that a shorter duration of seizures prior to surgery is predictive of positive mental and social age gains , a finding that is in keeping with those of freitag and tuxhorn   and basheer et al . .
in general , children with ie in our country are not exposed adequately to environmental stimuli as schooling is discontinued in the presence of seizures . with good postoperative seizure control ,
the child 's attention capacities increase and they engage in social interaction with their family and peers .
an improved school attendance due to seizure freedom improves their adaptive skills that in turn helps the child improve his performance in activities of daily living .
in our experience , over 90% of children with hemispheric and subhemispheric epilepsy syndromes achieve an excellent seizure outcome with less morbidity following epilepsy surgery . age of seizure onset and etiology of the disease causing epilepsy are independent predictive variables of a good seizure outcome .
following seizure freedom , improvement of function in the residual brain occurs that in turn leads to improvement in adaptive and social functions and quality of life .

Answer:
objectives : to study the outcome of disconnective epilepsy surgery for intractable hemispheric and sub - hemispheric pediatric epilepsy .
 methods : a retrospective analysis of the epilepsy surgery database was done in all children ( age < 18 years ) who underwent a peri - insular hemispherotomy ( pih ) or a peri - insular posterior quadrantectomy ( pipq ) from april 2000 to march 2011 .
 all patients underwent a detailed pre surgical evaluation .
 seizure outcome was assessed by the engel 's classification and cognitive skills by appropriate measures of intelligence that were repeated annually .
 results : there were 34 patients in all .
 epilepsy was due to rasmussen 's encephalitis ( re ) , infantile hemiplegia seizure syndrome ( ihss ) , hemimegalencephaly ( hm ) , sturge weber syndrome ( sws ) and due to post encephalitic sequelae ( pes ) .
 twenty seven ( 79.4% ) patients underwent pih and seven ( 20.6% ) underwent pipq .
 the mean follow up was 30.5 months . at the last follow up , 31 ( 91.1% ) were seizure free .
 the age of seizure onset and etiology of the disease causing epilepsy were predictors of a class i seizure outcome .
 conclusions : there is an excellent seizure outcome following disconnective epilepsy surgery for intractable hemispheric and subhemispheric pediatric epilepsy . an older age of seizure onset , re ,
 sws and pes were good predictors of a class i seizure outcome .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
thyroid lesions containing gross fat include heterotopic fat nests , thyrolipoma , teratoma , liposarcoma , and thyroid cancers of the papillary or follicular type ( 234567 ) .
most of these cases are only described upon obtaining pathological data after surgery ; radiologic methods are of limited use ( 89 ) . with the approval of the institutional review board of our hospital ,
we reported the case of an intrathyroid nodule composed mainly of gross fat detected by computed tomography ( ct ) and confirmed by lobectomy as a follicular variant of papillary thyroid cancer ( fvptc ) with mature fat .
a 58-year - old woman presented with an incidentally detected mass in the thyroid on routine ultrasonography ( us ) at a primary clinic .
the patient had a 10-year history of diabetes mellitus and hypertension , and was currently taking medication .
physical examination revealed a firm mass of approximately 3 cm in size in the right anterior neck .
laboratory tests revealed that serum anti - microsomal antibody , anti - thyroglobulin antibody , thyroglobulin , calcitonin , t3 , free t4 , and thyroid - stimulating hormone levels were within normal ranges .
ultrasonography revealed an ovoid lesion with a smooth margin of approximately 2.9  2  1.3 cm in size .
the nodule was generally hyperechoic , with the peripheral portion more hyperechoic than the central area .
the perithyroidal fat , muscle , and vertebral bodies were therefore not clearly visualized ( fig .
doppler us did not show any vascular signals in the nodule . based on these findings
a board - certified radiologist performed us - guided fine needle aspiration using a freehand technique with a 23-gauge needle and a 5-ml disposable plastic syringe .
cytologic smears were made on glass slides and immediately fixed in 95% alcohol for both papanicolaou staining and may - grunwald - giemsa staining .
cytology revealed atypia of undetermined significance or a follicular lesion of undetermined significance with negative for braf mutations and positive for an nras 61 mutation .
the thyroid ct protocol at our hospital includes pre - contrast , early , and delayed phases .
early phase images ( 40 seconds ) were scanned from the hyoid bone to the thoracic inlet to cover the entire thyroid and level iii - vi lymph nodes .
delayed scans ( 90 seconds ) covered the area from the skull base to the upper mediastinum .
all scans were acquired with a slice thickness of 2.5 mm and reconstruction increment of 2.5 mm .
pre - contrast ct showed markedly low attenuation ( mean ct number , -80 hounsfield units [ hu ] ) , in a well - defined mass with fine reticular and thick septa - like structures in the parenchyma of the right mid - to - upper portion of the thyroid ( fig .
1b ) . to measure the enhancement pattern of the tumor , 25 mm of the region of interest was placed in the area of the fatty mass , including the reticular and thick septa - like soft tissue lesions .
the tumor was enhanced in the early phase ( mean ct number , 16 hu ) and was washed out in the delayed phase ( mean ct number , -13 hu ) ( fig .
the tumor was ovoid in the longitudinal direction , had a lobular appearance in the axial plane , and was completely encapsulated in the thyroid parenchyma , with no evidence of extrathyroidal extension .
based on these findings , we suspected a fat - containing , neoplastic lesion of the thyroid gland , such as thyrolipoma , teratoma , lipoma , low - grade liposarcoma , or a follicular tumor with stromal fat . considering the results from cytopathology and the gene mutation analysis
it showed a yellowish , homogeneous , and well - demarcated nodular lesion measuring 2.5  2.2  1.5 cm at the upper - to - mid pole .
microscopic examination revealed a well - circumscribed , thin , fibrous , and capsulated nodule with mature fat .
there were atypical follicular cells with nuclear enlargement , nuclear overlapping , chromatin clearing , and nuclear grooves without papillary structures in the nodule ( fig .
on immunohistochemistry , the tumor cells stained positive for hbme-1 ( dako , glostrup , denmark , 1:100 ) and galectin-3 ( novocastra , newcastle upon tyne , uk , 1:200 ) . finally , we tested for the v600e and k601e mutations in exon 15 of the braf gene and codons 12 , 13 , and 61 of the kras and nras genes .
in our case , the tumor was a yellowish , homogeneous , and well - demarcated nodular lesion on gross examination , with negative value of attenuation on ct , suggesting fat .
however , it was difficult to recognize the tumor as a fat containing mass on us examination .
the hyperechoic nature of the mass and the curtain - like hyperechoic shadowing posterior to the mass may suggest rich fatty component .
we suspected that the hyperechoic shadowing might have been due to a reverberating artifact caused by innumerable fat globules and septa of the tumor , similar to the artifact frequently observed along the thick abdominal walls that consist of several layers of fat globules surrounded by connective tissues , skin , and fascia . computed tomography and gross specimen findings of our case were very similar to those of thyrolipoma , a benign fat - containing tumor ( 810 ) .
thyrolipoma is considered a variant of follicular adenoma , which is characterized by a well - circumscribed and encapsulated nodule resulting from the proliferation of thyroid follicles admixed with mature fat ( 1011 ) .
this case could have been misdiagnosed as a follicular neoplasm or thyrolipoma , as the tumor cells did not show a papillary growth pattern upon microscopic examination and the gross features were very similar to thyrolipoma .
two reports provided the ct and magnetic resonance imaging findings of thyrolipoma ( 812 ) .
the mass predominantly had fat attenuation and distinct margins in the thyroid gland . however , the authors only performed pre - contrast ct on the lesion .
therefore , it is uncertain whether thyrolipoma and thyroid cancer with massive stromal fat can be differentiated by ct with contrast enhancement . in our case ,
the tumor was enhanced in the early phase and slightly washed out in the delayed phase .
fat - containing thyroid cancer of the papillary or follicular type , have only been reported from pathological studies ( 2456 ) .
fat tissue was observed only by microscopy , so it was assumed that small amounts of fat tissue could not be detected by ct .
we also assumed that the detectability of the fat component is variable , as it depends on the total number of fat cells in the mass .
mature teratoma can be recognized if the fat - containing mass contains calcification , bone or cartilage , and cystic components .
however , this is not possible , as radiological images do not always exhibit all these attributes ( 7 ) .
ct images of liposarcoma ( 3 ) in the thyroid gland are very similar to those in our case , and differentiating between teratoma , thyrolipoma , liposarcoma , and papillary thyroid cancer with massive fat may be impossible using radiology alone .
some investigators have insisted that fat cells are derived from displaced remnants of embryonic structures in the thyroid . in amyloid goiter ,
schrder and bcker ( 1 ) postulated that adipose tissue may be derived from metaplasia of stromal fibroblasts due to either impaired circulation and diffusion or tissue hypoxia caused by amyloid deposition .
derienzo and truong ( 5 ) suggested that the fat cells in thyrolipoma and follicular carcinoma might be neoplastic tissue because 1 ) fat did not exist in the normal thyroid , 2 ) fat was a major component of the tumor , 3 ) there was no evidence of degenerative changes such as dystrophic calcification , cystic or hemorrhagic degeneration , or amyloid deposition , 4 ) fat was widely distributed in the tumor , and 5 ) there were similar fat - containing tumors in other organs such as thymolipoma , parathyroid adenoma , and fat - containing fibroadenoma of the breast .
our case showed similar microscopic features to theirs in agreement with the suggestion that the fat cells might be neoplastic cells themselves . in summary
these findings included a hyperechoic mass with a smooth margin with a reverberating artifact and no detectable doppler signal on us .
ct revealed a well - encapsulated fat - attenuation mass with enhancing septa - like structures .
fvptc should be included in the differential diagnosis of fat - containing focal lesions in the thyroid , in addition to thyrolipoma , teratoma , liposarcoma , and small focal fat nests near the capsule .
moreover , fine needle aspiration cytology with gene analysis may be helpful in determining the nature of fatty tumors before surgery .

Answer:
thyroid cancer may have small adipose structures detected by microscopy . however , there are no reports of thyroid cancer with gross fat evaluated by radiological methods .
 we reported a case of a 58-year - old woman with a fat containing thyroid mass .
 the mass was hyperechoic and ovoid in shape with a smooth margin on ultrasonography .
 on computed tomography , the mass had markedly low attenuation suggestive of fat , and fine reticular and thick septa - like structures .
 the patient underwent a right lobectomy .
 the mass was finally diagnosed as a follicular variant of papillary thyroid cancer with massive stromal fat .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
cleft lip and palate ( clp ) is one of the most common craniofacial anomalies of humans .
varied incidence of clp deformity caused due to unknown precise etiology is reported in the literature with severity ranging from minor notching of lip or bifid uvula to complete unilateral or bilateral cleft of the lip and palate .
newborns with abnormal oro - nasal communication face the threat to life due to difficulty in feeding . hence , there arises an acute demand of feeding appliance that serves as an obturator in the cleft area , in view of the complications of feeding tube .
a feeding appliance or obturator is a prosthetic aid that is used to restore the separation between oral and nasal cavities .
in addition , it is also the primary step in the fabrication of different devices such as palatal obturator , articulation development prosthesis , palatopharyngeal obturator , palatal lift prosthesis , nasal conformer , and appliances for presurgical infant orthopedic or presurgical nasoalveolar molding , those that are introduced to enhance speech , esthetics , and function .
it has been emphasized in literature that every precaution must be taken while making impression for neonates and infants with cleft palate , and surgeons ' presence is needed to manage airway emergency .
maneuvering the child 's head position forward to avoid the aspiration of impression material has been the only suggested precaution .
this does not ensure complete control over the impression material and avoidance of complication of impression material being pushed too deep into the nasal cavity or distally through the pharynx .
this clinical report presents dental putty - gauge hybrid impression technique as a simple and safe method of maxillary impression making in neonates and infants with cleft palate , permitting complete control over impression material during functional movements .
on extraoral examination , there was bilateral complete cleft lip with forward placed premaxilla [ figure 1 ] .
intraoral examination revealed a median cleft of the palate involving complete soft and hard palate [ figure 2 ] .
they were explained the treatment plan for fabrication of feeding plate and consent was obtained .
extraoral view showing bilateral cleft lip intraoral view showing cleft lip and palate it was planned to make the maxillary impression when the infant was fully awake , without any premedication or anesthesia .
the infant was seated upright in his mother 's lap in dental chair with face forward .
small size of the mouth opening did not permit the use of impression tray or flat wooden stick as carrier for the material . thus , it was planned to make impression with finger - loaded impression material . fast setting elastomeric putty impression material ( express std ,
3 m espe , usa ) was mixed and loaded on the index finger and an adequately large piece of gauze was wrapped all over the loaded impression material with loose ends wrapped toward the hand [ figures 3 and 4 ] .
the gauze permitted control over the material and restricted the excessive displacement of impression material toward the nasal cavity and pharynx [ figure 5 ] .
thick consistency of the impression material did not permit leakage of material through the gauze and kept it within the flexible confines of the gauze .
the resultant sucking pressure embedded the gauze threads in the putty impression material as the easily moldable gauge did not offer any resistance .
after the impression material was set , the impression was removed in toto from the patient 's mouth [ figures 6 and 7 ] .
then , the impression was poured in dental stone ( kalstone , kalabhai karson pvt ltd ) .
, mumbai , maharashtra , india ) and the master cast was obtained [ figure 8 ] .
single visit feeding obturator was fabricated using clear , flexible thermal - forming material with a midline extraoral extension for a hole to tie a safety thread [ figure 9 ] .
dental putty loaded on the index finger gauze wrapped around the putty impression material loaded on the finger maxillary impression made with functional movements by neonate hybrid impression retrieved in toto dental putty maxillary impression clear soft feeding obturator with safety thread attached feeding obturator in situ parents were demonstrated about the use and hygiene maintenance of the feeding plate .
a regular follow - up after 24 h and monthly follow - ups later were scheduled and the parents were advised to use the appliance till surgical intervention .
a cleft palate hampers intraoral pressure built - up required for suction and favors nasal reflex of food , thus posing challenge of middle ear infections .
feeding is an immediate concern for newborn with clp where the role of dentist and the feeding plate is evident .
various head and body positions and diverse impression materials have been used to make maxillary impression in neonates and infants with suggestions to take all precautions including the presence of surgeon to handle airway emergency . a feeding appliance bridges the gap between oral and nasal cavities .
feeding obturator becomes urgent in clp infants considering the health of the infant as surgical treatment usually starts at 23 months of age .
however , little is found in literature regarding the impression required to fabricate these maxillary appliances .
impression making is the initial , crucial , and clinical step in cleft palate of infants and poses a challenge because of lack of cooperation from patient , inadequate size of oral cavity , and nonavailability of suitable impression trays .
there is a risk of breakage of some parts of impression material that may get lodged in the undercut in the defect or the child can swallow or aspirate the material .
difficulty in withdrawal of impression , cyanotic events , and asphyxiation has been encountered during impression making
. displaced intranasal impression material may remain undetected for a very long period of time .
impression compound softened and placed on finger is the commonly used method to make preliminary impression .
individualized impression trays for clp have been designed and the tray handle has also been used to carry the material . impression making under general anesthesia has been adopted for infants .
adequate suctioning and resuscitation facilities should be available chairside . in case of airway emergency ,
it is advised to maneuver the infant position and head position to keep the tongue forward to avoid posterior displacement of impression material . making the child to cry throughout the impression procedure
however , it does not prevent the thin consistency material passing down the pharynx . in this case , the child was not crying during the procedure , but performed the functional movements to mold the impression material to obtain accurate anatomic details .
cleft palate affects feeding , facial growth , dentition development , speech , and may cause psychological problems for the child and parents as acceptance of the parents for the dysmorphic child can be difficult .
however , in the present case , parents were involved in the care from the start of therapy that provided assurance and motivation to them .
a variety of impression materials have been advocated ; however , putty type vinyl polysiloxane has been used in this case because its high viscosity reduces the risk of aspiration and there is no risk of thermal injury to the delicate oral mucosa of the neonate unlike that with the use of wax or thermoplastic impression compound . the use of gauze wrapped around the impression material throughout the functional movements completely removed the chances of aspiration or swallowing of material making , it a risk - free procedure in an awake child as young as 1-day - old .
however , in this patient , soft , clear , and flexible thermoplastic material was used as it permitted a single - step appliance fabrication .
the feeding plate was delivered without any delay , on the same day in view of the urgency for feeding the newborn .
the prosthetic therapy delivered through feeding plate remains a suitable treatment modality until the time prenatal diagnosis and intrauterine fetal surgery through feto - endoscopic approach for human fetus with a clp are well established .
this article describes the successful immediate oral rehabilitation of clp neonate achieved with simple feeding appliance and risk - free procedure that decreased the stress for the parents and the child and provided instant feeding ability .
maxillary impression procedure in infants with cleft palate poses a unique set of challenges and we should be well - equipped for every precaution while making impression .
the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s )
has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal .
the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .
the authors certify that they have obtained all appropriate patient consent forms . in the form the patient(s )
has / have given his / her / their consent for his / her / their images and other clinical information to be reported in the journal .
the patients understand that their names and initials will not be published and due efforts will be made to conceal their identity , but anonymity can not be guaranteed .

Answer:
cleft lip and palate is one of the most common craniofacial anomalies of humans .
 intraoral impression making is the first clinical step in the fabrication of feeding appliance for infants with oro - nasal communication .
 it is difficult to control the flow of the impression material in the cleft area and undercuts in a child patient .
 this clinical report presents a simple and safe impression technique for maxillary impression making in neonates and infants with cleft palate .
 a gauze piece was used to confine the impression material during functional movements of sucking while impression making in an awake child to avoid the risk of aspiration or swallowing .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
uncontrolled bleeding remains major challenge , responsible for 40% trauma - related deaths , which could be prevented by timely intervention . in blunt trauma , extent of hemorrhage
can not be determined by physical examination , as vital signs may not give a clear picture in all the patients , especially young healthy once .
although abnormal vital signs does indicate shock but the absence of abnormality does not exclude hypoperfusion in trauma patients .
decision - making is difficult , regarding surgical intervention to treat injuries hidden from physical examination .
these patients are intensely vasoconstricted and may suffer end organ ischemia even with normal systolic blood pressure ( sbp ) .
although shock index ( si ) can be a useful parameter in acute hemorrhage , but it still needs more study in its support to be better than simple vital sign analysis .
blood ammonia has been shown to be elevated in hemorrhagic shock in animals and humans .
intestinal bacterial enzymes acting on it produces ammonia which is freely diffusible and moreover liver in not fit for detoxification of ammonia .
we investigated the significance of ammonia levels estimation in blunt trauma abdomen patients to predict internal hemorrhage , complications and correlated with need of intervention .
one hundred blunt trauma abdomen patients ( > 12 years old ) presented in trauma ward / emergency department of tertiary care hospital were included in the study .
group i required blood transfusion 2 units and/or intervention to control bleeding within 24 h following admission .
it was analyzed within 20 min of sampling on autoanalyser cobas 6000 ( roche diagnostics india pvt ltd ) .
routine investigations such as blood sugar , kidney function test , hemogram , x - ray chest , and ultrasound abdomen were done at admission .
group i comprised 62 patients , forty patients needed intervention and blood transfusion both , whereas 22 patients needed only 2 units of blood .
average age was 31.84  14.8 and 32.37  13.6 years , respectively , almost same in both the groups .
most of the patients had more than one organ system involved and most frequently injured organ was liver ( 40% ) followed by spleen ( 29% ) .
mean si and arterial ammonia levels were significantly higher in group i compared to group ii patients [ table 1 ] .
about 88.7% patient of group i had si > 0.9 compared to only 13.1% patients in group ii [ table 2 ] .
significantly higher number of patients developed complications in group i compared to group ii ( 38 vs. 7 ) and 8% mortality rate was noted in group i only .
patients , who developed complications or died , had higher levels of ammonia at admission [ table 3 and figure 1 ] .
mean shock index and ammonia levels percentage of patients showing shock index 0.9/0.9 ammonia levels in patients with complications and mortality in group i receiver operating characteristic analysis of hospital stay , shock index , and ammonia levels the cutoff point for ammonia levels is > 58.85 mol / l ( sensitivity 77.42% and specificity 93.37% ) .
positive predictive value and negative predictive value at this point are 96.7% and 78.9% , respectively .
the cutoff point for ammonia levels is > 58.85 mol / l ( sensitivity 77.42% and specificity 93.37% ) .
positive predictive value and negative predictive value at this point are 96.7% and 78.9% , respectively .
roadside accidents were a major cause of trauma ( motor vehicle injury ) in our study probably due to increase population and number of vehicles on the road . similar cause has been reported by other studies also .
a maximum number of patients ( 78% ) were below the age of 40 years suggesting this age group people are more outgoing and rash drivers making them more prone to accidents .
male preponderance ( 93% ) noted in our study is higher than earlier studies , may be reflecting indian culture where male member of the family being breadwinner , needs to travel more than females .
the routine evaluation of blunt trauma abdomen patients includes various clinical parameters , physical examination , radiological and laboratory findings .
increased ammonia levels as observed in our study could itself be danger signal in these patients as it is sign of blood in abdominal cavity due to blunt trauma . intestinal bacterial enzymes acting on it produces ammonia which is freely diffusible and moreover liver in not fit for its detoxification as hemorrhage decreases hepatic blood flow through portal vein causing dysoxia of cells
. increased ammonia levels have been reported in animal hemorrhagic shock and in few human studies as well .
cutoff value for ammonia was also calculated to maximize sensitivity and specificity in identifying patients requiring intervention .
the purpose of this study was to augment the diagnostic accuracy of routine clinical assessment of such patient .
high ammonia levels in bleeding patients ( group i ) correlated well with si as 88.7% of these patients had si > 0.9 , i.e. , having potentially severe trauma requiring immediate treatment .
other workers have also reported similar si in bleeding patients . although si can be useful clinical parameter in acute hemorrhage which depicts severity of situation in heterogeneous patients presented in emergency but it still needs more study in its support to be single reliable parameter .
five patients died in group i had high ammonia levels ( 87.4 mol / l ) at admission .
high ammonia itself is toxic and can cause various complications , so it must be diagnosed and treated as early as possible .
moreover , trauma patient loses lots of valuable time in reaching trauma center , but once reached the hospital , they need to be diagnosed correctly and quickly .
biochemical marker which is time and cost effective such as ammonia estimation can predict need of intervention in these patients and best treatment can be provided in the golden hour .

Answer:
background : in blunt trauma , extent of hemorrhage can not be determined by physical examination , and vital signs may also not give clear picture in all the patients , especially young healthy ones .
 hemorrhagic shock has been reported to increase blood ammonia levels .
 arterial ammonia was analyzed in blunt trauma abdomen patients and correlated with shock index ( si ) .
 its predictive value was determined for timely decision of intervention.materials and methods : hundred blunt trauma abdomen patients presented in the emergency ward of tertiary care hospital were included in the study .
 group i comprised 62 patients requiring either blood transfusion 2 units and/or intervention to control bleeding within 24 h following admission .
 group ii had 38 patients : not requiring transfusion / intervention during hospital stay .
 arterial blood sample was taken immediately after admission ; ammonia was analyzed within 20 min of sampling on cobas 6000 ( roche ) .
 si was calculated .
 predictive value of ammonia was determined using receiver operating characteristic curve.results:ammonia levels and si were significantly ( p < 0.001 ) higher in group i compared to group ii patients ( 68.55  14.36
 umol / l vs. 37.55  7.41 umol / l and 1.28  0.5 vs. 0.74  0.12 , respectively ) .
 significantly higher number of patients in group i ( 88.7% vs. 13% ) had si > 0.9 .
 ammonia levels were significantly higher in patients with complications and in those expired.conclusions:ammonia levels were significantly higher in patients requiring blood transfusion / intervention in 24 h of admission .
 the best cutoff value to maximize sensitivity and specificity was ammonia > 58.85
 mol / l .
 ammonia estimation at admission can be clinically significant indicator of traumatic hemorrhage needing intervention .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
we conducted a preliminary screening of the 16s rrna methylase - producing bacilli on our gram - negative microbial stock of 2,877 strains isolated from japanese hospitals within the past several years .
arbekacin , a semisynthetic aminoglycoside belonging to the kanamycin group , requires 2 modifications at the ( 6  ) aminogroup and the ( 2   ) hydroxyl group for inactivation , so this agent is not inactivated by known plasmid - mediated aminoglycoside - modifying enzymes .
512 mg / l ) was used as a marker for screening the 16s rrna methylase - producing strains .
all arbekacin - resistant strains were subjected to polymerase chain reaction ( pcr ) analysis to detect rmta , rmtb , or arma , and all strains were pcr positive , except for a strain of acinetobacter demonstrating a very high level of resistance to arbekacin ( mic 1,024 mg / l ) .
this strain was later shown to produce both aminoglycoside 6-acetyltransferase and 2-adenyltransferase ( 12 ) , so arbekacin was inactivated in this strain by both 6-acetylation and 2-adenylation .
each pcr primer set was used to detect rmta and rmtb genes as in our previous reports ( 6,7 ) .
the pcr primers for amplification of arma were newly designed ( forward : 5-agg ttg ttt cca ttt ctg ag-3  , reverse : 5-tct ctt cca ttc cct tct cc-3  ) , and the predicted size of the amplicon was 590 bp .
these 3 sets of pcr primers were very reliable in detecting rmta , rmtb , and arma genes , respectively .
each pcr amplicon was then subjected to sequencing analyses on both strands to confirm its nucleotide sequences for detecting mutations in the methylase genes .
as reported in our previous study , rmta and rmtb genes had been found in p. aeruginosa isolates ( 6,10 ) and in 1 strain of s. marcescens ( 7 ) , respectively . as shown in the table , 5 p. aeruginosa strains isolated after our previous report ( 6 ) were rmta positive .
the rmtb gene was additionally identified in 4 k. pneumoniae , 2 e. coli , and 1 k. oxytoca strains in japan . to our surprise ,
the arma gene , which had been found in various gram - negative microbial species belonging to the family enterobacteriaceae exclusively in europe as reported by galimand et al .
( 13 ) , was also identified in japan in 1 strain each of e. coli , s. marcescens , and acinetobacter sp .
notably , the arma and rmtb genes were also recently identified in k. pneumoniae and e. coli in taiwan ( 9 ) .
furthermore , the genetic environment of the arma gene found in c. freundii isolated in poland was similar to that of k. pneumoniae isolated in france .
the genetic environments of the arma gene found in the 3 japanese microbial species , e. coli , s. marcescens , and acinetobacter sp . , ( genbank accession nos . ab116388 and ab117519 ) , were also similar to those found in europe ( genbank accession nos . af550415 and ay220558 ) .
these findings suggest that the arma - producing gram - negative nosocomial microbes that harbor a very similar genetic environment carrying the arma gene have spread globally .
as described previously , arbekacin still shows a very broad antimicrobial spectrum from gram - positive to gram - negative nosocomial microbes and has been approved solely to treat methicillin - resistant staphylococcus aureus ( mrsa ) infections in japan since 1990 to ensure the prudent use of this agent .
the emergence and presence of the 16s rrna methylase - producing gram - negative bacilli , however , has not been well recognized in japan to date ; arbekacin has not been listed among the antimicrobial agents for daily antimicrobial susceptibility testing of gram - negative microbes .
the use of semisynthetic aminoglycosides , including arbekacin , in japanese clinical settings for > 10 years may have promoted the emergence and dissemination of the 16s rrna methylase - producing gram - negative microbes in japan .
the large amount of various aminoglycosides used in livestock - farming environments could have also been a selective pressure for the emergence and spread of pathogenic microbes that harbor genetic determinants for the newly identified 16s rrna methylases , as exemplified by recent isolation of arma - producing e. coli from swine in spain ( genbank accession no .
since acquisition of multidrug resistance against clinically important antimicrobial agents such as carbapenems and fluoroquinolones has been developing rapidly worldwide , the acceleration of even greater aminoglycoside resistance among gram - negative bacilli promises to become an actual clinical concern in the near future , just as vancomycin - resistant enterococci ( vre ) did in the 1990s ( 14 ) .
the emergence of gram - positive cocci including mrsa and vre that acquire the 16s rrna methylase could also be a grave clinical matter , although fortunately no such hazardous microbes have been identified .
thus , steps must be taken to further block proliferation of these multidrug - resistant gram - negative super microbes , including p. aeruginosa , k. pneumoniae , and acinetobacter spp .
, as well as multidrug - resistant cocci such as mrsa and vre , which have acquired an extraordinarily high level of resistance to various aminoglycosides through production of 16s rrna methylases , especially in clinical environments .

Answer:
emergence of the newly identified 16s rrna methylases rmta , rmtb , and arma in pathogenic gram - negative bacilli has been a growing concern .
 arma , which had been identified exclusively in europe , was also found in several gram - negative pathogenic bacilli isolated in japan , suggesting global dissemination of hazardous multiple aminoglycoside resistance genes .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
unlike tears and ganglion cysts of the anterior cruciate ligament ( acl ) , mucoid degeneration is a less - understood entity .
the injury or loss of functional synovial lining protecting the acl is the primary lesion causing mucoid degeneration of acl though there was no significant preceding trauma that patients can relate to current symptoms.1 but the symptomatology , mri findings , and arthroscopy appearance are consistent.2 the excision of the degenerated acl has been the treatment of the choice , the authors believe that if the taut and hypertrophied acl were to be debulked and notchplasty done , full extension could be achieved without having to excise the entire acl .
the purpose of this study was to describe the clinical characteristics and diagnosis of mucoid degeneration of the acl and to assess the outcomes of arthroscopic treatment in a series of 20 patients .
the mean age was 42.2 years ( range 28 - 52 years ) in males and 39.4 years ( range 30 - 54 years ) in females .
all the patients had clinical symptoms of central knee pain behind patella without any prior trauma ( 18 patients on terminal extension and 2 patients on terminal flexion ) . in four patients , there was mean flexion deformity of 6. the type of activity performed was : physically active like running , sports , and army training ( n=6 , 30% ) ; moderately active doing routine work ( n=12 , 60% ) ; and sedentary ( n=2 , 10% ) .
the symptoms started insidiously , had a mean duration of 21 months ( range 1247 months ) without preceding significant trauma .
eighteen patients had extension deficit and two patients had limited flexion.34 there was medial joint pain in two patients .
anterior lachman and anterior drawer test showed firm endpoint in all patients , with + 1 laxity in three patients .
all patients were treated with nonsteroidal anti - inflammatory drugs and physiotherapy for a minimum of 2 months before contemplating magnetic resonance imaging ( mri ) and treatment .
plain roentgenograph of both the knees was done with anteroposterior weight bearing , lateral and skyline views .
radiographic diagnosis was made only when all three key criteria56 were met : ( 1 ) abnormally thickened and ill - defined acl , ( 2 ) maintenance of normal orientation and continuity , and ( 3 ) increased intraligamentous signals ( intermediate signal intensity on t1-weighted images and high signal intensity on t2-weighted and proton density weighted images [ figure 1 ] .
proton density show increasing intraligamentous signal intensity of the anterior cruciate ligament over the left knee arthroscopy was performed by use of a 30 lens through standard anterolateral and anteromedial portals .
all compartments were explored to evaluate the state of menisci , ligaments , and cartilage .
the chondral lesion of each patient was described according to the outerbridge classification.7 the locations of the lesions on the articular surfaces of the patella , trochlea , medial femoral condyle , lateral femoral condyle , medial tibial plateau , and lateral tibial plateau were recorded .
bulk specific to anteromedial ( am)posterolateral ( pl ) bundles of acl , its color , and its tautness hooked with probe were recorded .
impingement of acl fibers to lateral wall of intercondylar notch , and lateral compartment during flexion  extension maneuver were recorded [ figure 2 ] .
arthroscopic examination of a left knee , showing impingement ( arrow ) of hypertrophied posterolateral portion of acl to lateral wall and roof of intercondylar notch during extension the aim of surgery was to remove as much of the degenerative mass as possible without having to sacrifice the entire acl .
thus , the remaining acl consisted of some intact anteromedial or posterolateral portion of the acl interspersed with degenerate acl tissue .
care was taken to see that this remaining acl had intact attachment to the femoral condyle and did not impinge on the roof or lateral wall of the notch [ figure 3 ] . by use of basket forceps ,
the materials were stained with h and e and then with mucoid tissue - specific alcian blue [ figure 4 ] . in knees without notch narrowing , debridement of the hypertrophied acl was performed first beginning with the removal of small osteocartilaginous fragments from the upper portion of the lateral wall and roof by use of a 6.4-mm curved osteotome .
this allowed easier inspection of the inner space between the acl and the lateral wall , and accurate removal of impinging structures .
we decompressed the lateral wall and roof from anterior to posterior while performing a flexion  extension maneuver with a 4.5-mm motorized bur and curette .
care was taken to remove all visible impinging structures in the posterior portion of the notch .
copious debridement of mucoid hypertrophied lesions of the acl was performed by use of basket forceps as well as a 4.2-mm motorized shaver .
some of the mass was removed by first teasing between the anterior fibers of the acl using a probe and then removing it with an arthroscopy grabber .
the major posterior portion of the mass was removed using the basket punch ( acufex ) introduced through the anteromedial portal , with the arthroscope through the anterolateral portal .
the probe was used to assess the tension and the clearance of the remaining acl and the notch .
arthroscopic examination of a left knee , showing impingement of hypertrophied posterolateral portion of acl to lateral wall and roof of intercondylar notch during extension photomicrograph showing distorted collagen fibers with scanty myxomatous degeneration ( h and e stain , 40 ) during the followup , no immobilizer or brace was used except in one patient who had undergone acl reconstruction .
all other patients were encouraged to perform daily active range of motion exercises with quadriceps strengthening and allowed to carry full weight bearing loads immediately .
preoperative central knee pain on terminal extension was moderate in 10 knees and severe in 8 knees .
postoperatively , 12 knees showed complete pain relief and 7 showed pain improvement by at least 3 visual analogue scale ( vas ) grades , for a total of 16 had well to excellent results regarding pain on terminal extension .
preoperative average international knee documentation committee ( ikdc ) score8 was 33.6 which improved postoperatively to the average 73.2 .
the flexion deformity was found in four patients , with a mean angle of 6. postoperatively , it improved significantly with no deformity .
mris of all 20 patients showed an acl that appeared bulky , occupying almost the entire intercondylar notch , with a marked increased signal , particularly in the t2-weighted images , and with a mass - like configuration intertwined with its fibers with  celery stalk
sign.910 on mri , 6 patients had medial compartment arthritis , 4 patients had torn medial meniscus grade iii , and 1 patient had grade ii tear in posterior horn of lateral meniscus .
arthroscopy showed osteoarthritic changes in 9 knees and concomitant degenerative pathologies in 4 knees ; these included meniscal tears and synovitis .
six ( 30% ) degenerative lesions of the medial meniscus and 1 ( 0.5% ) degenerative lesion of lateral meniscus were noted .
three femoropatellar cartilaginous lesions ( 15% ) , 4 ( 20% ) medial femorotibial lesions ( two grade 1 , one grade 2 , one grade 3 ) , and 1 ( 0.5% ) lateral femorotibial lesion grade 1 were observed .
it filled the entire intercondylar notch and was unusually taut , toward 90 of flexion in 2 patients with hypertrophied am bundle of acl , and taut in extension in rest of the patients with hypertrophied pl bundle of acl .
the posterolateral portion of the acl bulged into the lateral compartment in extension impinging in the notch . by flexion
when each knee was brought into full extension , impingement of the hypertrophied acl to the lateral wall and roof of the intercondylar notch was observed.1112 impingement was particularly apparent in knees with a severely hypertrophied acl or narrowed notch , as well as limited knee joint extension .
arthroscopic treatment consisted of debridement of the afflicted portion of the acl in all cases . in six knees with evident notch narrowing
, notchplasty was performed first . because yellowish degenerative hypertrophied lesions were entangled around the posterolateral acl fibers , the anteromedial portion was retained in 18 patients . in 2 patients , posterolateral portion of acl was retained because of hypertrophied degenerated am bundle of acl .
although in one patient after debridement , the remaining portion of the acl was not enough to stabilize the knee , so we had to reconstruct the acl with hamstring graft which is comparable with the study by lintz et al.(7%).1 at an average followup time of 24 months ( range 12 - 36 months ) , all except two patients had a full range of painless motion .
it was 1 grade higher as compared with the opposite knee in 14 knees and the same as the opposite knee in 6 knees .
all patients had a firm endpoint on lachman test without any symptoms of instability , inferring some intact portion of the acl between the tibia and the femur .
two patients had pivot shift positive + 1 with glide and 18 patients had negative pivot shift .
a soft endpoint on anterior translation would imply no intact acl tissue in the intercondylar area . the histopathologic appearance and reports of the biopsy specimens were consistent with mucoid degeneration of the acl .
regression of the size and bulkiness of the treated acl was seen , with the t2-weighted images showing decreased signal with some intact acl fibers between the tibia and femur .
the mucoid hypertrophy of the acl is a rare condition found in middle - aged individuals .
mucoid degeneration of anterior cruciate ligament is not an uncommon pathology , but is often unknown . according to bergin
et al.6 and salvati et al.,13 reported its occurrence as 2 and 5% , respectively , of knee where mri was done .
our findings were incidental in initial 4 cases where clinical and radiological findings were not correlated as radiologist reported partial rupture of acl only . in practice and in the literature , it is often confused with a diagnosis of partial acl rupture . it becomes apparent in two subpopulations of patients .
the first group is younger , active , athletic , in whom we can assume an acl mechanism affected by real trauma or repeated microtraumas causing an early lesion.14 the second group is older and presents with progressive degenerative acl lesions , with frequent concomitant degenerative meniscal lesions .
the pathogenesis of mucoid degeneration is unclear , but injury , ganglion cysts , and degenerative process leading to loss of synovial lining have been implicated as the most likely etiologic factors in the production of this change . in younger group
the possible cause of repetitive minor trauma is impingement of the acl to the lateral wall and roof of the narrow notch , which has been reported to be more common in female patients.15 in second group there is subtle alterations in joint kinematics due to osteoarthritis , meniscal tears , and other degenerative changes , leading to stretching of cruciate ligaments .
fealy et al.16 suggested that knee pain on flexion might be caused by tensioning of the diseased am bundle of the acl .
for kumar et al.18 the pain is attributable to the effect of the acl mass in the posterior notch .
hsu et al.19 and kim et al.11 attribute it to incarceration of the pathological acl in the posterior femoro - tibial compartment .
however , we found that the hypertrophied acl bulged into the lateral compartment , impinged on the lateral tibiofemoral joint , and caused an extension or flexion block , depending on the position of the impingement in the lateral tibiofemoral joint .
we believe the most important source of pain is mechanical impingement , associated with unique function of the acl in providing nociceptive sensory signals .
it is mentioned elsewhere only by mcintyre et al.2 who reported one case of atraumatic acl rupture at 1 postoperative year after partial resection .
our results indicate that postoperative laxity , largely asymptomatic , can increase anterior laxity over time and evoke instability .
mucoid hypertrophy of the acl should be clinically suspected in elderly person presenting with persistent knee pain on terminal extension without preceding trauma , especially when associated with extension deficit , which is more common in elderly individual with degenerated knee .
arthroscopic debridement of mucoid hypertrophy of the acl in conjunction with notchplasty can effectively provide symptomatic improvement without instability .

Answer:
background : mucoid degeneration of the anterior cruciate ligament ( acl ) is a less understood entity . the purpose of this study was to diagnose mucoid degeneration of anterior cruciate ligament and to assess the effectiveness of arthroscopic treatment in these patients.materials and methods : between december 2007 and november 2011 , 20 patients were diagnosed to be suffering from mucoid degeneration of anterior cruciate ligament ( acl ) on the basis of magnetic resonance imaging ( mri ) , histopathology , and arthroscopy findings .
 12 patients were males and 8 patients were females , with mean age of 42.2 years for males ( range 28 - 52 years ) and 39.4 years for females ( range 3054 years ) .
 they presented with pain on terminal extension ( n=10 ) and on terminal flexion ( n=2 ) without history of significant preceding trauma .
 mri showed an increased signal in the substance of the acl both in the t1- and t2-weighted images , with a mass - like configuration that was reported as a partial or complete tear of the acl by the radiologist . at arthroscopy ,
 the acl was homogenous , bulbous , hypertrophied , and taut , occupying the entire intercondylar notch .
 a debulking of the acl was performed by a judicious excision of the degenerated mucoid tissue , taking care to leave behind as much of the intact acl as possible . releasing it and performing a notchplasty treated impingement of the acl to the roof and lateral wall . in one patient , we had to replace acl due to insufficient tissue left behind to support the knee.results:good to excellent pain relief on terminal flexion  extension was obtained in 19 of 20 knees .
 the extension deficit was normalized in all knees .
 lachman and anterior drawer test showed a firm endpoint in all , and 85% ( n=17 ) showed good to excellent subjective satisfaction.conclusions:mucoid hypertrophy of the acl should be suspected in elderly persons presenting pain on terminal extension or flexion without preceding trauma , especially when there is no associated meniscal lesion or ligamentous insufficiency .
 they respond well to a judicious arthroscopic release of the acl with notchplasty .


Question:
You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
success in endodontic treatment is best defined by the contemporary endodontic triad of diagnosis , anatomy , and debridement . in the learning curve of endodontics ,
the incisor tooth forms the basics due to its simple morphology of one root - one canal .
the common developmental anomalies in a maxillary lateral incisor ( mli ) includes peg - shaped crown , radicular groove , talon cusp , and dens invaginatus ( di ) . from an endodontic perspective
considering the occurrence of additional canals , the literature shows that , mli with a maximum of four canals and with dens formation , three root canals have been reported .
teeth with di are often recognized clinically due to their unusual crown form or extremely marked foramen caecum and many a time may show no clinical signs of the malformation .
however , due to the limitation of conventional radiographs in assessing root canal configuration , complex root canal morphology due to dental anomalies such as multiple root canals , two roots and dens formation poses a considerable diagnostic challenge to achieve the required success .
nevertheless , advanced radiographic techniques such as the cone beam computed tomogram ( cbct ) helps in a three - dimensional evaluation of a particular tooth to overcome the limitations of conventional radiography .
the purpose of the present case report is to discuss the endodontic procedure adopted to negotiate the complex tooth morphology of a peg - shaped mli with di and five root canals ( frc ) .
the present case is about a 17-year - old male patient who was referred to the department of endodontics with a primary complaint of heaviness and pain in relation to the upper front tooth .
clinical evaluation revealed no significant extraoral findings . on intraoral examination , both the mlis appeared peg - shaped .
however , the right lateral incisor was associated with a soft tissue swelling in the labial vestibule [ figure 1a ] , tender on percussion and gave a negative response to electric pulp testing .
intra oral periapical radiograph of the maxillary right lateral incisor revealed ill - defined periapical radiolucency associated with an unusual canal morphology and di [ figure 1b ] . based on the clinical and radiological findings
( a ) peg - shaped lateral incisor with intra - oral swelling in the labial vestibule .
( b ) radiograph revealing periapical radiolucency associated with right lateral incisor and presence of dens invaginatus .
( d ) radiograph with instruments in five canals the need for an endodontic therapy was explained to the patient and was advised to take a course of analgesics and antibiotics ( amoxicillin 500 mg , metronidazole 400 mg , ibuprofen 400 mg thrice daily for 5 days ) .
the patient was administered local anesthesia of 2% lidocaine with 1:100,000 epinephrine . under rubber dam isolation ,
an access opening was made and an orifice ( c1 ) was visualized after copious amount of purulent discharge was allowed to drain through the c1 .
the endodontic explorer was placed in the c1 and verified with an apex locator ( sybron endo mini , sybron endo , glendora , usa ) and radiograph .
however , as the drainage of purulent discharge persisted , a calcium hydroxide intra - canal medicament ( calcicur , voco , cuxhaven , germany ) was placed and access cavity was temporarily sealed .
( cavit , 3 m espe ag , seefold , germany ) . after 3 days
, the calcium hydroxide was removed from c1 and subtle changes were noted at some points over the sub - pulpal floor , which suggested the possibility of additional canals away from the c1 that was located on the labial half . in order to locate the possibility of a palatal canal , the access cavity was redefined in the distopalatal ( dp ) region and the second canal ( c2 )
was identified and negotiated successfully . on further probing in the distolabial ( dl ) region , two additional orifices ( c3 and c4 )
however , the orifices of c3 and c4 were interconnected . with four instruments placed in the respective canals , the radiograph showed the presence of another unidentified canal .
the fifth canal orifice ( c5 ) was located at the mesiopalatal ( mp ) aspect , summing - up to five canals all with separate apical exit [ figure 1c and d ] .
each time an orifice was identified , it was checked with an apex locator to rule out perforation .
coronal flaring alone was performed with protaper rotary ni ti instruments ( dentsply , maillefer ) and subsequent cleaning and shaping was completed by hand instrumentation ( dentsply , maillefer ) due to the constricted coronal pulp space .
a cbct scanning was done to study the tooth morphology , which confirmed the presence of a single root with five canals with separate apical exit and a type iii di [ figure 2a and b ] .
( c ) radiograph taken after root canal filling and placement of temporary restoration in the access cavity .
( d ) follow - up radiograph after 12 months showing signs of healing one week later the tooth was obturated in the third visit , with gutta - percha and sealer ( apexit , ivoclar vivadent ) by cold lateral compaction technique [ figure 2c ] .
the patient was periodically monitored , with satisfactory healing and the follow - up period of 12 months was uneventful [ figure 2d ] .
dens invaginatus is a developmental malformation resulting from invagination of the crown or root before calcification has occurred . with a reported incidence from 0.04% to 10%
, di can be found affecting either the primary or the permanent dentition , and commonly involving the mlis .
cases of bilateral occurrence and rare cases are reported in molars , premolars , and maxillary central incisors .
an indian study reported a prevalence of 0.5% of surveyed teeth ; however , according to a chinese study , di was found in 517 permanent teeth from 67 chinese individuals , which account for 5% of di .
the literature shows that mli with a maximum of four canals has been reported , but as far as the author 's knowledge , this is the first case with frc , especially in a peg - shaped lateral incisor complicated by the presence of di . according to the literature , di in a mli is considered as unusual .
type 2 involves the root , but does not reach the apex , and in type 3 , the invagination extends past the periapical region with and without manifesting an additional apical foramen .
the pathways of infection in a di is found to be due to hypomineralized internal enamel and the thin canals or fissures in the dentin connecting the invagination to the pulp cavity through which microorganisms and irritating agents from the oral cavity gain access to the pulpal space leading to pulp alterations .
the challenge posed in this case is the restricted access coupled with complex and unpredictable morphology of the root canal system .
krape and fidler emphasized the need and suggested incisal edge as the predominant location of straight - line access in anterior teeth .
various treatment techniques have been reported in the literature , including preventive sealing or filling of the invagination , root canal treatment with or without endodontic apical surgery , intentional replantation and extraction .
removal of di using hand files and gates glidden drills and with the aid of an operating microscope and subsequent root canal treatment has also been described .
the presence of multiple root canals in a peg - shaped mli complicated by di poses substantial difficulty in diagnosis and treatment as well as achieving endodontic success for better prognosis .
the present case has been evaluated and negotiated with the aid of conventional radiographs and by applying law of symmetry , cemento enamel junction and orifice location .
the complicated tooth morphology with multiple root canals warrant use of cbct to define and confirm the canal morphology .
in line with a molar tooth , the multiple canals in this case is named according to the surface in which it is located namely c1  mesiolabial , c2  dp , c3 and c4  dl1 and dl2 , and c5  mp , respectively [ figure 1c ] .
case selection is the key in successful outcome of a treatment . treating a tooth with a unique morphology
definitely tests the clinical knowledge , skill of the operator and one should be ready for any kind of pulp space variant that could exist . although , cbct would have been beneficial to precisely define and confirm the canal location in a complicated morphology , the present case illustrates the successful negotiation with conventional radiographs .

Answer:
this case report describes endodontic treatment completed in a peg - shaped maxillary lateral incisor , with single root and five root canals of which , one is due to dens invaginatus .
 cone beam computed tomogram scanning confirmed the unique morphology of the tooth .
 new nomenclature for the five canals is proposed .