Micro-/bio-/nano-/syn-encapsulations and co-treatments of bioactive microbial feed supplementation in augmenting finfish health and aquaculture nutrition: a review

Finfish and fish products are globally the most acknowledged health-promoting foods. The rising incidence of pathogenic and disease outbreaks have had a sizeable impact on aquaculture. Microbial supplementation of food in the form of probiotics, prebiotics, and their controlled release combinations (=co-encapsulations) as 'synbiotics' is noted for its significant biotherapeutic and health benefits. Supplementation of probiotic microbial feed additives in the fish diet claims to improve fish health by modulation of resident intestinal microbiota and by introducing healthy microbiota procured from an exogenous source, capable of combating pathogens, improving nutrient uptake, assimilation, growth as well as survival. Prebiotics are selectively digestible substrates beneficially used by host gut microbes to enhance probiotic effects. Formulating a fish diet with augmented probiotics and prebiotic microbial bio-supplements can ensure a sustainable alternative for establishing fish health in a naturally susceptible aquaculture scenario. Micro-encapsulation, co-encapsulation, and nano-encapsulation are novel strategies of biotechnical interventions in functional feeds for finfish. These aim to improve probiotic persistence, survivability, and efficacy in commercial formulations during probiotic transit through the host-gut environment. This review discusses the importance of co-treatment and encapsulation strategies for improving probiotic and prebiotic potential in aquafeed formulations, reliably improving finfish health and nutritional returns from aquaculture, and, consequently, for consumers.

The impact of reclassification of C3 predominant glomerulopathies on diagnostic accuracy, outcome and prognosis in patients with C3 glomerulonephritis

Background

C3 glomerulonephritis is a recently described entity with heterogeneous histopathological features. This study was conducted to assess the effect of reclassification of C3 glomerulopathies on renal outcomes, mortality, and response to therapy.

Methods

We undertook a retrospective analysis of 857 renal biopsies collected at The Canberra Hospital. Samples with predominant C3 staining were reviewed by a renal histopathologist. Of 31 biopsies with predominant C3 staining, 10 fulfilled histological criteria for C3 glomerulonephritis, while the remaining 21 cases were used as C3 Controls.

Results

Aside from a higher incidence of C3 glomerulonephritis in Torres Strait islanders (40% vs 5% C3 Controls, p = 0.04), presentation demographics were similar between the two groups. Median creatinine at diagnosis was higher in patients with C3 glomerulonephritis (253 umol/L IQR 103–333 vs 127 umol/L C3 Controls, IQR 105–182, p = 0.01).

Prior to reclassification, a majority of C3 glomerulonephritis cases were diagnosed as membranoproliferative glomerulonephritis (60% vs 5% (C3 Controls) p < 0.01). Electron microscopy demonstrated all C3 glomerulonephritis patients had C3 deposition (100% vs 38% p = 0.02), these deposits were amorphous in nature (50% vs 5% respectively p = 0.007).

C3 glomerulonephritis patients had shorter median follow-up (405 days IQR 203–1197 vs 1822 days respectively, IQR 1243–3948, p = 0.02). Mortality was higher in C3 glomerulonephritis patients (30% vs 14% in C3 Controls (log rank p = 0.02)).

Conclusion

We have devised a diagnostic and treatment algorithm based on the results of literature review and our current study. Further prospective assessment is required to review diagnostic and treatment outcomes for this disease in Australian centres.

Inflammatory bowel disease in patients with Hirschsprung's disease: a systematic review and meta-analysis

AIM AND OBJECTIVES

Hirschsprung-associated enterocolitis (HAEC) continues to be an important cause of morbidity in patients with Hirschsprung's disease (HSCR). HAEC can occur at any time during the course of the disease. The reported incidence of HAEC before surgery ranges from 6 to 50%, and after surgery, it ranges from 2 to 35%. HAEC and inflammatory bowel disease (IBD) have similar clinical presentation including diarrhea, hematochezia, and abdominal pain. In recent years, isolated cases of IBD have been reported in patients who had surgical treatment for HSCR. The exact pathogenesis of HAEC or IBD is not known. However, both conditions are characterized by an abnormal intestinal mucosal barrier function, which may be a common pathway. The purpose of this meta-analysis was to determine the clinical presentation and outcome in patients with HSCR who developed IBD after pull-through operation.

MATERIALS AND METHODS

A systematic literature search for relevant articles was performed in four databases using the combinations of the following terms "inflammatory bowel disease", "Crohn/Crohn's disease", "ulcerative colitis", and "Hirschsprung disease/Hirschsprung's disease" for studies published between 1990 and 2017. The relevant cohorts of HSCR associated with IBD were systematically searched for clinical presentation and outcomes.

RESULTS

14 studies met defined inclusion criteria, reporting a total of 66 patients who had HSCR associated with IBD. Mean age at first operation for HSCR was 5.8 months, mean age at diagnosis of IBD was 7.7 years, and the majority of patients were male (73%). The extent of aganglionosis was total colonic aganglionosis in 41% of patients, long segment in 45%, and rectosigmoid in 14%. The majority of patients underwent a Duhamel procedure (84%) for HSCR. The distribution of IBD was Crohn's disease in 72.3% of patients, ulcerative colitis in 16.9%, and others in 10.8%. Eight articles (47 patients) reported about HAEC, and 22 patients (47%) had experienced HAEC after surgery for HSCR.

CONCLUSION

Male patients with extensive colonic aganglionosis who continue to suffer from postoperative HAEC after a Duhamel procedure are more susceptible to develop IBD. Recognition of IBD may be important in the long-term follow-up of HSCR patients who have had postoperative HAEC.

Liver Function Tests Abnormalities and Hepatitis B Virus & Hepatitis C Virus Co-infection in Human Immunodeficiency Virus (HIV)-infected Patients in India

BACKGROUND

While highly active anti-retroviral therapy (HAART) has improved survival of HIV-infected patients, there is increasing liver disease and progressive Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) related liver disease.

AIMS

To study the liver function tests (LFT) and HBV and HCV co-infection in HIV-infected patients.

MATERIAL AND METHODS

All HIV-positive patients presenting to a tertiary level hospital from April 2009 to April 2011 were evaluated. Baseline LFT, CD4/CD8 counts, ultrasound abdomen, HBsAg, IgG anti-HBc, HBVDNA, Anti-HCV and HCVRNA were done in all patients. LFT was repeated monthly or more frequently with anti-tubercular therapy (ATT)/HAART.

RESULTS

Abnormal LFT were seen in 143/320 (44.6%) HIV-infected patients (n = 320; M-282, F-38; mean age-35.4 ± 7.3 years). Baseline LFT was abnormal in 48 (15%) [hepatotropic viruses-19, alcohol-24, NAFLD-1, disseminated TB-1, idiopathic-03). Subsequent LFT derangement developed in 95/272 (34.9%). In the majority, the LFT abnormality was mild (119/143-83.2%) and multi-factorial [HAART 132 (76.4%), alcohol 69 (48.2%), ATT 31 (21.7%), HBV 16 (11.2%), HCV 15 (10.4%)]. Using multivariate analysis, abnormal LFT were associated with HAART (OR, 5.92; 95%CI, 2.83-12.37), ATT (OR, 2.06; 95%CI, 1.06-3.99) or HCV infection (OR, 2.54; 95%CI, 1.03-6.26). Significant hepatotoxicity requiring drug modification was seen in only 7 cases. HBV, HCV and HBV + HCV co-infection were seen in 37 (11.6%), 28 (8.8%) and 2 (0.6%) respectively. Occult co-infections were rare [HBV-1 (0.3%); HCV-3 (0.9%)].

CONCLUSION

While LFT abnormalities in HIV are common, they are usually mild and multifactorial. HBV and HCV co-infections were seen in 11.6% and 8.8%, respectively. Occult HBV and HCV infections were rare.

Long-term results of transanal pull-through for Hirschsprung's disease: a meta-analysis

INTRODUCTION

Several operative techniques have been developed for the treatment of Hirschsprung's disease (HD) in the past decades. Since one-stage transanal pull-through (TAPT) was first performed in 1998, multiple studies have shown favourable short-and midterm results compared to other techniques with shorter operation length, shorter hospital stay and lower complication rates. The aim of this meta-analysis was to determine the longterm results following TAPT for HD.

METHODS

A systematic literature search for relevant articles was performed in four databases using the following terms "Hirschsprung/Hirschsprung's disease", "aganglionosis", "transanal", "pullthrough/pull-through", "longterm/long-term" "results", "follow-up" and "outcome". A meta-analysis was conducted for relevant articles for one-stage transanal pull-through for HD with a minimal follow-up of median 36 months regarding constipation, incontinence/soiling, enterocolitis and secondary operations. Odds ratio (OR) with 95 % confidence intervals (CI) were calculated.

RESULTS

Six studies with 316 patients matched the set criteria and were included in this analysis. Overall 45 (14.2 %) patients had disturbances of bowel function (OR 0.05, 95 % CI 0.03-0.07, p < 0.00001). Of these, 24 (53.3 %) patients experienced constipation, 8 (17.8 %) incontinence/soiling and 13 (28.9 %) enterocolitis. 10 (3.2 %) patients developed complications requiring secondary surgery. Most patients had a daily defecation frequency of 1-3 bowel movements 3 years postoperatively, resembling the stooling patterns of healthy controls.

CONCLUSION

Nearly 15 % of all patients operated with TAPT for HD continue to experience persistent bowel symptoms with constipation as the main problem. Further studies on the long-term outcome of children operated with this technique for HD are necessary to evaluate stooling patterns, urinary and sexual function as well as general quality of life during adolescence and adulthood.

Knockout mouse models of Hirschsprung's disease

PURPOSE

Hirschsprung's disease (HSCR) is a developmental disorder of the enteric nervous system, which occurs due to the failure of neural crest cell migration. Rodent animal models of aganglionosis have contributed greatly to our understanding of the genetic basis of HSCR. Several natural or target mutations in specific genes have been reported to produce developmental defects in neural crest migration, differentiation or survival. The aim of this study was to review the currently available knockout models of HSCR to better understand the molecular basis of HSCR.

METHODS

A review of the literature using the keywords "Hirschsprung's disease", "aganglionosis", "megacolon" and "knockout mice model" was performed. Resulting publications were reviewed for relevant mouse models of human aganglionosis. Reference lists were screened for additional relevant studies.

RESULTS

16 gene knockout mouse models were identified as relevant rodent models of human HSCR. Due to the deletion of a specific gene, the phenotypes of these knockout models are diverse and range from small bowel dilatation and muscular hypertrophy to total intestinal aganglionosis.

CONCLUSIONS

Mouse models of aganglionosis have been instrumental in the discovery of the causative genes of HSCR. Although important advances have been made in understanding the genetic basis of HSCR, animal models of aganglionosis in future should further help to identify the unknown susceptibility genes in HSCR.

Strategies to manage hepatitis C virus (HCV) infection disease burden - volume 2

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 15 countries, and the relative impact of two scenarios was considered: (i) increased treatment efficacy while holding the treated population constant and (ii) increased treatment efficacy and increased annual treated population. Increasing levels of diagnosis and treatment, in combination with improved treatment efficacy, were critical for achieving substantial reductions in disease burden. In most countries, the annual treated population had to increase several fold to achieve the largest reductions in HCV-related morbidity and mortality. This suggests that increased capacity for screening and treatment will be critical in many countries. Birth cohort screening is a helpful tool for maximizing resources. In most of the studied countries, the majority of patients were born between 1945 and 1985.

The present and future disease burden of hepatitis C virus (HCV) infections with today's treatment paradigm - volume 2

Morbidity and mortality attributable to chronic hepatitis C virus (HCV) infection are increasing in many countries as the infected population ages. Models were developed for 15 countries to quantify and characterize the viremic population, as well as estimate the number of new infections and HCV related deaths from 2013 to 2030. Expert consensus was used to determine current treatment levels and outcomes in each country. In most countries, viremic prevalence has already peaked. In every country studied, prevalence begins to decline before 2030, when current treatment levels were held constant. In contrast, cases of advanced liver disease and liver related deaths will continue to increase through 2030 in most countries. The current treatment paradigm is inadequate if large reductions in HCV related morbidity and mortality are to be achieved.

Historical epidemiology of hepatitis C virus (HCV) in select countries - volume 2

Chronic hepatitis C virus (HCV) infection is a leading cause of liver related morbidity and mortality. In many countries, there is a lack of comprehensive epidemiological data that are crucial in implementing disease control measures as new treatment options become available. Published literature, unpublished data and expert consensus were used to determine key parameters, including prevalence, viremia, genotype and the number of patients diagnosed and treated. In this study of 15 countries, viremic prevalence ranged from 0.13% in the Netherlands to 2.91% in Russia. The largest viremic populations were in India (8 666 000 cases) and Russia (4 162 000 cases). In most countries, males had a higher rate of infections, likely due to higher rates of injection drug use (IDU). Estimates characterizing the infected population are critical to focus screening and treatment efforts as new therapeutic options become available.

The impact of Clostridium difficile on paediatric surgical practice: a systematic review

PURPOSE

The pathogenic potential of Clostridium difficile in children remains a controversial subject as healthy infants can be colonised by this organism. However recent analyses have clarified that C. difficile is an important enteropath in paediatric populations, particularly in antibiotic-associated diarrhoea. Paediatric surgical patients including those with Hirschsprung's disease (HD) may be especially vulnerable to C. difficile infection (CDI) and complicated C. difficile enterocolitis such as pseudomembranous colitis may require surgical management if refractory to medical therapy. Reports of increasing prevalence and emergence of hyper-virulent strains of C. difficile worldwide prompted an examination of the literature to assess the impact of CDI on current paediatric surgical practise.

METHODS

The literature was searched using a combination of the MESH terms "hirschsprung's disease", "enterocolitis", "clostridium difficile", and "children". Cases of Hirschsprung's associated enterocolitis (HAEC) investigated for C. difficile and complicated CDI in non HD patients were identified and analysed for clinical parameters, diagnostic evaluations, surgical interventions and outcome.

RESULTS

Pathogen isolation in HAEC was infrequently described. Only 98 children have been reported with C. difficile during an episode of HAEC over the last 40 years and aetiology remains unclear as asymptomatic carriage of C. difficile in HD occurs. Nonetheless 34 confirmed cases of pseudomembranous colitis complicating HD are reported in the literature with an associated 50 % mortality rate. Over 20 % of non Hirschsprung's patients with reported severe or complicated CDI required operative intervention. The need for surgery was associated with the presence of co-morbidity and high mortality occurred in this group.

CONCLUSION

Severe or complicated CDI in both HD and non HD paediatric patients is associated with high mortality and often requires surgical intervention. Although these patient cohorts represent a small number of cases, CDI should be suspected in children presenting with enterocolitis to enable early diagnosis and timely surgical intervention, particularly in patients with co-morbid conditions or preceding antibiotic use.

Randomised clinical trial: Lactobacillus GG modulates gut microbiome, metabolome and endotoxemia in patients with cirrhosis

BACKGROUND

Safety of individual probiotic strains approved under Investigational New Drug (IND) policies in cirrhosis with minimal hepatic encephalopathy (MHE) is not clear.

AIM

The primary aim of this phase I study was to evaluate the safety, tolerability of probiotic Lactobacillus GG (LGG) compared to placebo, while secondary ones were to explore its mechanism of action using cognitive, microbiome, metabolome and endotoxin analysis in MHE patients.

METHODS

Cirrhotic patients with MHE patients were randomised 1:1 into LGG or placebo BID after being prescribed a standard diet and multi-vitamin regimen and were followed up for 8 weeks. Serum, urine and stool samples were collected at baseline and study end. Safety was assessed at Weeks 4 and 8. Endotoxin and systemic inflammation, microbiome using multi-tagged pyrosequencing, serum/urine metabolome were analysed between groups using correlation networks.

RESULTS

Thirty MHE patients (14 LGG and 16 placebo) completed the study without any differences in serious adverse events. However, self-limited diarrhoea was more frequent in LGG patients. A standard diet was maintained and LGG batches were comparable throughout. Only in the LGG-randomised group, endotoxemia and TNF-α decreased, microbiome changed (reduced Enterobacteriaceae and increased Clostridiales Incertae Sedis XIV and Lachnospiraceae relative abundance) with changes in metabolite/microbiome correlations pertaining to amino acid, vitamin and secondary BA metabolism. No change in cognition was found.

CONCLUSIONS

In this phase I study, Lactobacillus GG is safe and well-tolerated in cirrhosis and is associated with a reduction in endotoxemia and dysbiosis.

A new genome scan for primary nonsyndromic vesicoureteric reflux emphasizes high genetic heterogeneity and shows linkage and association with various genes already implicated in urinary tract development

Primary vesicoureteric reflux (VUR), the retrograde flow of urine from the bladder toward the kidneys, results from a developmental anomaly of the vesicoureteric valve mechanism, and is often associated with other urinary tract anomalies. It is the most common urological problem in children, with an estimated prevalence of 1–2%, and is a major cause of hypertension in childhood and of renal failure in childhood or adult life. We present the results of a genetic linkage and association scan using 900,000 markers. Our linkage results show a large number of suggestive linkage peaks, with different results in two groups of families, suggesting that VUR is even more genetically heterogeneous than previously imagined. The only marker achieving P < 0.02 for linkage in both groups of families is 270 kb from EMX2. In three sibships, we found recessive linkage to KHDRBS3, previously reported in a Somali family. In another family we discovered sex-reversal associated with VUR, implicating PRKX, for which there was weak support for dominant linkage in the overall data set. Several other candidate genes are suggested by our linkage or association results, and four of our linkage peaks are within copy-number variants recently found to be associated with renal hypodysplasia. Undoubtedly there are many genes related to VUR. Our study gives support to some loci suggested by earlier studies as well as suggesting new ones, and provides numerous indications for further investigations.

Adriamycin-Induced Models of VACTERL Association

Animal models are of great importance for medical research. They have enabled analysis of the aetiology and pathogenesis of complex congenital malformations and have also led to major advances in the surgical and therapeutic management of these conditions. Animal models allow us to comprehend the morphological and molecular basis of disease and consequently to discover novel approaches for both surgical and medical therapy. The anthracycline antibiotic adriamycin was incidentally found to have teratogenic effects on rats, producing a range of defects remarkably similar to the VACTERL association of congenital anomalies in humans, providing a reproducible animal model of this condition. VACTERL association is a spectrum of birth defects which includes vertebral, anal, cardiovascular, tracheo-oesophageal, renal and limb anomalies. In recent years, adriamycin rodent models of VACTERL have provided valuable insights into the pathogenesis of this complex association, particularly in relation to tracheo-oesophageal malformations. The adriamycin rat model and adriamycin mouse model are now well established in the investigation of the morphology of faulty organogenesis and the regulation of gene expression in tracheo-oesophageal anomalies.

Investigation of L-type Ca(2+) current in the aganglionic bowel segment in Hirschsprung's disease

BACKGROUND

Studies on animal models of Hirschsprung's disease (HD) suggest that L-type Ca(2+) channels are down-regulated in the aganglionic bowel segment, however, this has yet to be confirmed in HD patients. The objective of this study was to test the hypothesis that L-type Ca(2+) current density is decreased in smooth muscle cells (SMC) obtained from the aganglionic bowel segment of patients with HD in comparison with those from the ganglionic segment.

METHODS

Smooth muscle cells were freshly isolated from colon samples obtained from HD patients undergoing pull-through surgery. L-type Ca(2+) currents were recorded using the perforated patch configuration of the whole cell voltage clamp technique and the expression levels of CACNA1C transcripts (which encode L-type Ca(2+) channels) in the ganglionic and aganglionic bowel segments were compared using real-time quantitative PCR.

KEY RESULTS

All SMC displayed robust currents that had activation/inactivation kinetics typical of L-type Ca(2+) current, were inhibited by nifedipine and enhanced by the L-type Ca(2+) channel agonists FPL 64176 and Bay K 8644. Moreover, FPL 64176 activated currents were also inhibited by nifedipine. However, there was no significant difference in L-type Ca(2+) current density, CACNA1C subunit expression or sensitivity to the pharmacological agents noted above, between SMC isolated from the ganglionic and aganglionic regions of the HD colon.

CONCLUSIONS & INFERENCES

In contrast to studies on genetic animal models of HD, L-type Ca(2+) currents are not down-regulated in the aganglionic bowel segment of HD patients and are therefore unlikely to account for the impaired colonic peristalsis observed in these patients.

Modified-orientation log to assess hepatic encephalopathy

BACKGROUND

The subjectivity of the West-Haven criteria (WHC) hinders hepatic encephalopathy (HE) evaluation. The new HE classification has emphasised assessment of orientation. The modified-orientation log (MO-log, eight questions, scores 0-24; 24 normal) is adapted from a validated brain injury measure.

AIM

To validate MO-log for HE assessment in cirrhosis.

METHODS

Cirrhotics admitted with/without HE were administered MO-log. We collected cirrhosis/HE details, admission/daily MO-logs and WHC (performed by different examiners), time to reach normal mentation (MO-log ≥23) and MO-log/WHC change (Δ) over day 1. Outcomes were in-hospital mortality, duration to normal mentation and length-of-stay (LOS). Regressions were performed for each outcome. MO-log inter-rater reliability was measured.

RESULTS

Ninety-six HE (55 ± 8 years, MELD 21) and 20 non-HE (54 ± 5 years, MELD 19) in-patients were included. In HE patients, median admission WHC was 3 (range 1-4). Mean MO-log was 12 ± 8 (range 0-22). Their LOS was 6 ± 5 days and 13% died. Time to reach normal mentation was 2.4 ± 1.7 days. Concurrent validity: there was a significant negative correlation between admission MO-log and WHC (r = -0.79, P < 0.0001). Discriminant validity: admission MO-logs were significantly lower in those who died (7 vs. 12, P = 0.03) and higher in those admitted without HE (23.6 vs. 12, P < 0.0001). MO-log improved in 69% on day 1 (ΔMO-log 4 ± 8) which was associated with lower duration to normal mentation (2 vs. 3.5 days, P = 0.03) and mortality (3% vs.43%, P < 0.0001), not ΔWHC. Regression models for all outcomes included admission/ΔMO-log but not WHC as a predictor. Inter-rater reliability: ICC for MO-log inter-rater observations was 0.991.

CONCLUSIONS

Modified-orientation log is a valid tool for assessing severity and is better than West-Haven criteria in predicting outcomes in hospitalised hepatic encephalopathy patients.

The spatio-temporal patterning of Hoxa9 and Hoxa13 in the developing zebrafish enteric nervous system

BACKGROUND

Hirschsprung's disease is characterised by the absence of ganglion cells in the distal bowel, a process which is controlled by complex genetic pathways. Homeobox genes have a major role in gut development and this is depicted by the enteric Hox code which describes the different spatial and temporal expression of Hox genes. Hoxa9 and Hoxa13 mutations have been discovered in patients with Hirschsprung's disease (HD). The aim of this study was to determine the spatio-temporal pattern of Hoxa9 and Hoxa13 in enteric nervous system (ENS) development using the zebrafish model.

METHODS

Purified plasmids that contained the gene of interest were obtained and inoculated into culture medium to exponentially increase the number of bacteria containing the plasmid. Cells were then harvested by centrifugation and plasmid DNA was extracted, which was then linearised and precipitated. RNA digoxigenin-labelled probes were made by in vitro transcription reaction. In situ hybridisation was carried out using these probes on zebrafish embryos which were collected from 24 to 120 h post fertilisation (hpf), by which time the zebrafish intestine is fully developed. Embryos were then mounted in glycerol and imaged using an Olympus B40 microscope and images were taken using an Olympus Super F1.8 digital camera.

RESULTS

At 24 hpf, Hoxa9 expression is seen in the forebrain and hindbrain and also in the very distal myotome whereas Hoxa13 expression, however, is seen only at the forebrain and hindbrain. At 48 hpf, Hoxa9- and Hoxa13-labelled cells are seen migrating distally from the forebrain into the notochord and spinal cord. At 72 hpf, Hoxa9-labelled cells can be seen throughout the spinal cord whereas Hoxa13 positive cells are seen migrating down from the spinal cord and in the proximal gut. By 96 hpf, Hoxa9- and Hoxa13-labelled cells have migrated down the full length of the spinal cord and along the proximal and mid intestine. By 120 hpf, Hoxa9 and Hoxa13 positive cells can be seen along the entire length of the zebrafish intestine.

CONCLUSIONS

These results show further evidence that Hoxa9 and Hoxa13 are involved in the early and organised patterning of ENS development in the zebrafish model.

COUP-TFII gene expression is upregulated in embryonic pleuroperitoneal folds in the nitrofen-induced congenital diaphragmatic hernia rat model

INTRODUCTION

The nitrofen model of congenital diaphragmatic hernia (CDH) creates a Bochdalek-type diaphragmatic defect and has been widely used to investigate the pathogenesis of CDH. However, the exact pathogenesis of the diaphragmatic defect in this model is still poorly understood. Chicken ovalbumin upstream promotor-transcription factor II (COUP-TFII) is expressed in the embryonic pleuroperitoneal folds (PPF) in the early stage of development and in the diaphragm in the late days of gestation. COUP-TFII is known to be a strong repressor of the retinoid signaling pathway (RSP), which plays an important role in diaphragm development. Furthermore, it has been recently shown that COUP-TFII is upregulated during early gestation in the nitrofen-induced hypoplastic lung. We designed this study to investigate the hypothesis that COUP-TFII gene expression is upregulated during early diaphragmatic development in the PPF.

MATERIAL AND METHODS

Timed pregnant rats were exposed to either olive oil (Control) or nitrofen (CDH) on day 9 of gestation (D9). Fetuses were sacrificed on D13, D18 or D21. The PPF was dissected from D13 fetuses using laser capture microdissection. Diaphragms were dissected from D18 and D21 fetuses under the dissection microscope. The relative mRNA expression levels of COUP-TFII were determined using real-time PCR. Immunohistochemistry was performed to evaluate diaphragmatic protein expression and the distribution of COUP-TFII.Results On D13, gene expression levels of COUP-TFII in the PPF were significantly increased in the CDH group (82.93 ± 11.85) compared to Controls (46.22 ± 8.09; p < 0.05), whereas there were no differences at later time points. The immunoreactivity of diaphragmatic COUP-TFII was markedly increased in the PPF in the CDH group compared to controls on D13. No difference in immunoreactivity was observed on D18 and D21.

CONCLUSION

Upregulation of COUP-II gene expression in the PPF may contribute to the diaphragmatic defect in the nitrofen CDH model by inhibiting the RSP.

PROMIS computerised adaptive tests are dynamic instruments to measure health-related quality of life in patients with cirrhosis

BACKGROUND

Cirrhotic patients have an impaired health-related quality of life (HRQOL), which is usually analysed using static paper-pencil questionnaires. The Patient Reported Outcomes Measurement Information System (PROMIS) computerised adaptive testing (CAT) are flexible, freely available, noncopyrighted, HRQOL instruments with US-based norms across 11 domains. CAT presents five to seven questions/domain depending on the patient's response, from large validated question banks. This provides brevity and precision equivalent to the entire question bank.

AIM

To evaluate PROMIS CAT tools against 'legacy instruments' for cirrhotics and their informal caregivers.

METHODS

A total of 200 subjects: 100 cirrhotics (70 men, 53% decompensated) and 100 caregivers were administered the PROMIS and legacy instruments [Sickness Impact Profile (SIP), Beck depression/anxiety inventories, Pittsburgh Sleep-Quality Index (PSQI) and Epworth Sleepiness scale (ESS)] concurrently. Both legacy and PROMIS results for patients were compared with caregivers and US norms. These were also compared between compensated and decompensated patients. Preference for SIP or PROMIS was inquired of a selected group (n = 70, 50% patients). Test - retest reliability was assessed in another group of 20 patients.

RESULTS

Patients had significant impairment on all PROMIS domains apart from anger and anxiety compared with caregivers and US norms (P < 0.02 to <0.0001). Decompensated patients had significantly worse sleep, pain, social and physical function scores compared with compensated ones, similar to legacy instruments. There was a statistically significant correlation between PROMIS and their corresponding legacy instruments. The majority (71%) preferred PROMIS over SIP. PROMIS tools had significant test - retest reliability (ICC range 0.759-0.985) when administered 12 ± 6 days apart.

CONCLUSION

PROMIS computerised adaptive testing tools had significant concurrent and discriminant validity, test - retest reliability and subject preference for assessing HRQOL in cirrhotic patients.

Downregulation of FGFRL1 contributes to the development of the diaphragmatic defect in the nitrofen model of congenital diaphragmatic hernia

INTRODUCTION

The nitrofen model of Congenital Diaphragmatic Hernia (CDH) displays a diaphragmatic defect of the Bochdalek-type and has been widely used to investigate the pathogenesis of CDH. However, the exact pathomechanism of the diaphragmatic defect is still poorly understood. Fibroblast growth factor (FGF) receptor-like 1 (FGFRL1), a member of the FGF receptor family, plays a key role in physiological diaphragmatic development. FGFRL1 is expressed in the fetal diaphragm at low levels in early gestation and its expression steadily increases, becoming most pronounced in later gestational stages. It has been reported that FGFRL1 homozygous null mice have thin, partially amuscular diaphragms and die at birth due to respiratory failure. The aim of this study was to investigate the hypothesis that FGFRL1 gene expression in the diaphragm is downregulated during the later gestational stages in the nitrofen CDH model.

MATERIAL AND METHODS

Timed pregnant rats were exposed to either olive oil or 100 mg nitrofen on day 9 of gestation (D9). Cesarean section was performed on D18 or D21. Fetal diaphragms (n=40) were micro-dissected and divided into CDH group and controls. Total RNA was extracted from the diaphragms and the mRNA levels of FGFRL1 were determined using real-time PCR. Immunohistochemistry was performed to evaluate diaphragmatic protein expression of FGFRL1. Student's t-test and Mann-Whitney test were used, where appropriate. Statistical significance was considered for p<0.05.

RESULTS

Relative mRNA expression levels of FGFRL1 were significantly decreased in the CDH group compared to controls on D18 (3.63 ± 1.65 vs. 6.04 ± 3.12, p<0.05) and D21 (1.36 ± 1.01 vs. 2.57 ± 1.34, p<0.05). Immunoreactivity of FGFRL1 was markedly decreased in the diaphragms of the CDH group compared to controls on D18 and D21.

CONCLUSION

Our data provide strong evidence that downregulation of the FGFRL1 gene during the late stages of gestation may contribute to the development of the diaphragmatic defect in nitrofen-induced CDH.

Down-regulation of lung Kruppel-like factor in the nitrofen-induced hypoplastic lung

INTRODUCTION

Pulmonary hypoplasia is a primary cause of high morbidity and mortality in neonates with Congenital Diaphragmatic Hernia (CDH). However, the precise pathogenesis of PH associated with CDH is still not clearly understood. It has been recently reported that lung Kruppel-like factor (LKLF), a member of the Kruppel-like factor family of transcription factors, is predominantly expressed in lungs and plays an important role in lung morphogenesis and functional maturation. It has been reported that homozygous deletion of LKLF gene in mice results in reduced lung morphogenesis. It is further reported that chimeric mice derived from LKLF (-/-) embryonic stem cells exhibit delayed lung development especially in the later gestational stages. We therefore designed this study to test the hypothesis that the LKLF gene is down-regulated during later stages of lung development in nitrofen-induced hypoplastic lungs.

MATERIAL AND METHODS

Pregnant rats were exposed to either olive oil or nitrofen on day 9 of gestation (D9). Fetal lungs were harvested on D15, D18, and D21 and divided into 3 groups:control, nitrofen without CDH(CDH(-)) and nitrofen with CDH(CDH(+)) (n=24 for each group). Real-time RT-PCR analysis was performed to investigate pulmonary gene expression levels of LKLF. Differences between the 3 groups at each time point were tested statistically and significance was accepted at p<0.05. Immunohistochemistry was also performed to evaluate LKLF protein expression and distribution.

RESULTS

The relative mRNA expression levels of LKLF on D18 and D21 were significantly decreased (p<0.01) in CDH(-) and CDH(+) groups compared to controls. The gene expression levels of LKLF on D15 did not differ significantly between the nitrofen group and controls. Immunohistochemical study showed strong LKLF immunoreactivity on D18 and D21 in nitrofen-induced hypoplastic lung compared to controls, whereas no difference was seen on D15.

CONCLUSIONS

Our results provide evidence for the first time that LKLF is down-regulated in the later stages of lung development in nitrofen-induced hypoplastic lungs. These data suggest that the down-regulation of LKLF during this critical period of lung morphogenesis may impair lung development and maturation, resulting in pulmonary hypoplasia in the nitrofen CDH model.

IGFBP-4 gene overexpression in the nitrofen-induced hypoplastic lung

PURPOSE

The precise mechanism of pulmonary hypoplasia (HP) associated with congenital diaphragmatic hernia (CDH) remains unclear. Insulin-like growth factors (IGFs) play an essential role in fetal lung development through IGF receptors (IGFRs) by regulating cellular proliferation, differentiation and survival. It has been reported that the expression of genes involved in IGF-IGFR signaling is altered in the nitrofen-induced hypoplastic lung during the later stages of lung development. IGF-binding proteins (IGFBPs) control bioavailability, activity and disruption of IGFs through the high affinity IGFBP/IGF complexes. IGFBP-4 is a key inhibitor of IGF-IGFR signaling-mediated cell proliferation. It has been revealed that cell proliferation in fetal lung fibroblasts is inhibited by increased IGFBP-4 production. We hypothesized that IGFBP-4 gene expression is increased during the later stages of lung development in the nitrofen-induced CDH lung.

METHODS

Pregnant Sprague-Dawley rats were exposed to either olive oil or nitrofen on day 9 (D9) of gestation. Fetuses were harvested by cesarean section on D18 and D21. Fetal lungs were divided into 3 groups: control, nitrofen without CDH [CDH(-)] and nitrofen with CDH [CDH(+)] (n=24 at each time point). Relative mRNA levels of IGFBP-4 were determined using real-time RT-PCR. Immunohistochemistry was performed to evaluate the protein expression of IGFBP-4.

RESULTS

The relative expression levels of IGFBP-4 mRNA were significantly increased in CDH(-) and CDH(+) groups on D18 and D21 compared to controls. Immunohistochemistry showed increased IGFBP-4 expression in mesenchymal compartments on D18 and D21 in hypoplastic lungs compared to controls.

CONCLUSION

Overexpression of pulmonary IGFBP-4 during the later stages of lung development may contribute to pulmonary hypoplasia in the nitrofen-induced CDH model by inhibiting IGF-mediated cell proliferation.

A serious drug interaction leading to spontaneous total hyphema

A 70 year-old diabetic man receiving anti-coagulant therapy (Warfarin) for pulmonary embolism secondary to factor V Leiden deficiency, presented to the hospital for chest pain. After initial evaluation, he was started on aspirin (300 mg) and clopidogrel (300 mg). Three days after he was discharged, he presented with preseptal cellulitis complicating left upper eyelid chalazion. Initially, he was treated with several anti-microbial agents used sequentially. Although, the cellulitis resolved, he developed total hyphema of the left eye. The complication seems to have resulted from a complex interaction amongst anti-microbial agents, Warfarin and anti-platelet agents.

Prevalence of Celiac Disease in Children with Unexplained Failure to Thrive

BACKGROUND

Gluten sensitive enteropathy or celiac disease (CD) is a disorder of small bowel that occurs upon exposure to gluten. A total of 67 children of either sex in the age group of 1-12 years with unexplained failure to thrive were studied for the prevalence of CD.

METHODS

This was a cross-sectional study. It included detailed history, clinical assessment, estimation of anti gliadin (AGA), tissue transglutaminase antibodies (tTGA) and duodenal biopsy. Treatment with gluten free diet and follow-up of diagnosed cases was done for one year.

RESULT

Sixteen cases (23.88%) had villous atrophy and positive serology, essential criteria for the diagnosis of CD. Forty six (69%) children were between 4-12 years of age. Male to female ratio was 2.3:1. Main symptoms were irritability (63%), diarrhea (56%) and weight loss (56%). Thirty seven (56%) children had weight less than 3(rd) percentile. tTGA was 100% sensitive and 90.2% specific. Duodenal biopsy showed decreased villious-crypt ratio in 81.25% and intra epithelial lymphocytosis in 81% children (p<0.000001). All the confirmed cases were advised strict gluten free diet for one year. On follow-up at six months, all children showed improvement in their symptoms and weight gain.

CONCLUSION

CD is an important cause of unexplained failure to thrive in children.

Laparoscopic appendectomy after conservative management of appendix mass

The purpose of this study was to demonstrate the safety and efficacy of laparoscopic appendicectomy following non-operative management of appendix mass in children. Medical records of 103 consecutive patients (61 males, 42 females) who underwent non-operative treatment of appendix mass followed by laparoscopic elective appendicectomy were examined. Their ages ranged from 2 years 5 months to 15 years (mean 8.3 years). All patients were treated conservatively by close observation, antibiotics and intravenous fluids. Once the child was fit for discharge laparoscopic elective appendicectomy was booked for 4-6 weeks later. Ninety-three children responded to the initial conservative treatment and were discharged after a mean hospital stay of 5.6 days (range 3-10 days). Ten (9.7%) did not respond to initial treatment and developed appendix abscess requiring drainage. Average hospital stay in the 97 patients who had laparoscopic elective appendicectomy was 2.5 days (range 1-5 days). Three patients developed complications after elective appendicectomy, a stitch abscess in one, paralytic ileus in one and wound infection in one. Histological examination revealed fibrosed or resolving appendicitis in 52, acute or subacute appendicitis in 24, carcinoid tumour in two and normal appendix in 19. Laparoscopic elective appendicectomy is a safe and effective method of treatment following conservative treatment of appendix mass. Not only does it make the dissection and resection of the appendix easier but it also has the added advantage of performing adhesiolysis.

Penile malignant peripheral nerve sheath tumour (schwannoma) in a three-year-old child without evidence of neurofibromatosis

Malignant schwannoma (malignant peripheral nerve sheath tumour, MPNST) is a rare high-grade tumour arising from peripheral nerves. We report the case of a 3-year-old male who presented with a non-tender lesion on the dorsum of his penis. The lesion was excised and a formal circumcision performed. Histology of the lesion revealed a spindle cell tumour. Immunohistochemistry showed the tumour cells to be strongly positive for S100 and Vimentin. A diagnosis of intermediate grade malignant peripheral nerve sheath tumour was made. Malignant schwannoma is rare in children and is previously unreported in the penis in the paediatric age group without evidence of neurofibromatosis.

Gastroschisis and exomphalos in Ireland 1998-2004. Does antenatal diagnosis impact on outcome?

Antenatal detection of anterior abdominal wall defects (gastroschisis and exomphalos) enables detailed prenatal planning and counselling with appropriate intrauterine transfer, delivery in a tertiary referral centre with prompt access to paediatric surgery and early surgical intervention. The authors believed that there was a relatively low rate of antenatal detection in Ireland and that an improved antenatal screening program would allow increased detection thus avoiding emergency retrievals from peripheral obstetric centres. Our hypothesis was that there was a significant difference in management and outcome in children with anterior abdominal wall defects detected antenatally and those detected at birth. All anterior abdominal wall defects in The Republic of Ireland are assessed and closed in two surgical centres, Our Lady's Hospital for Sick Children, and the Children's University Hospital, Dublin. A retrospective review of all admissions in both centres revealed 96 neonates with anterior wall defects (excluding bladder exstrophy and cloaca) over a 7 year period from 1998 to 2004 inclusive. Medical records, operative reports, neonatal databases and admission details were reviewed. The antenatal data search included anomaly detection, prenatal management plan and intrauterine transfer. Perinatal data included place of birth, weight, gestational age, mode of delivery, time to surgery and type of surgery, the time to establish full enteral feeding and the length of hospital stay were used as overall markers of outcome. Fifty-three patients had gastroschisis and 43 exomphalos with an antenatal detection rate of 53% (n = 28) and 34% (n = 15), respectively, with an overall detection rate of 44%. There was no significant difference in the median birth weight (2.83 vs. 2.85 kg), gestational age at birth (37 vs. 37 weeks), time to full feeding (12 vs.14 days) and length of stay (20 vs. 17 days) between those detected antenatally or postnatally, respectively. About 77 had a primary closure performed of which 63 infants had surgery within the first 24 h of life. There was no difference in the time to surgery, frequency of complications or the surgical outcome in either group. Intrauterine transfer did not affect any outcome measure assessed. The demographics and the presence of associated anomalies did not differ between the groups. The hypothesis that antenatal diagnosis in anterior abdominal wall defects improves outcome has been demonstrated to be false. Despite this result, the importance of antenatal screening and prenatal management of complex foetal conditions with consultation with experienced paediatric and neonatal staff is without doubt.

A genome-wide scan for genes involved in primary vesicoureteric reflux

BACKGROUND

Vesicoureteric reflux (VUR) is the retrograde flow of urine from the bladder into the ureters. It is the most common urological anomaly in children, and a major cause of end-stage renal failure and hypertension in both children and adults. VUR is seen in approximately 1-2% of Caucasian newborns and is frequently familial.

OBJECTIVE AND METHODS

In order to search for genetic loci involved in VUR, we performed a genome-wide linkage scan using 4710 single-nucleotide polymorphisms (SNPs) in 609 individuals from 129 Irish families with >1 affected member.

RESULTS

Nonparametric linkage (NPL) analysis of the dataset yielded moderately suggestive linkage at chromosome 2q37 (NPL(max) = 2.67, p<0.001). Analysis of a subset without any additional features, such as duplex kidneys, yielded a maximum NPL score of 4.1 (p = 0.001), reaching levels of genome-wide statistical significance. Suggestive linkage was also seen at 10q26 and 6q27, and there were several smaller peaks.

CONCLUSION

Our results confirm the previous conclusion that VUR is genetically heterogeneous, and support the identification of several disease-associated regions indicated by smaller studies, as well as indicating new regions of interest for investigation.

T-cell epitope mapping of ORF2 and ORF3 proteins of human hepatitis E virus

Little data are available on cellular immune responses during infection with hepatitis E virus (HEV). We therefore mapped CD4 T-cell epitopes in open reading frame (ORF)2 and ORF3 proteins of HEV using lymphocyte proliferation assays and overlapping peptide libraries. Proliferation of peripheral blood mononuclear cells from 40 patients with acute hepatitis E and 21 healthy controls with recombinant HEV ORF2 protein or pools of overlapping HEV ORF2/ORF3 peptides was measured. HLA-DQB1 and HLA-DRB1 alleles were also determined. Mononuclear cells from patients with hepatitis E more often showed significant proliferation on stimulation with recombinant ORF2 protein than controls (32/40 vs 7/21), and had higher median (range) stimulation indices [2.6 (0.9-15.2) vs 1.3 (0.6-12.9)]. Peptide pools corresponding to amino acids 73-156, 289-372, 361-444 and 505-588 of HEV ORF2 protein were associated with significant proliferation. Individual peptides in these pools did not show a clear pattern of stimulation. HEV ORF3 peptide pools did not induce proliferative responses. Lymphocyte proliferation in response to the peptide pool corresponding to amino acids 289-372 of HEV ORF2 protein was associated with presence of HLA-DRB1 allele 010X. These data on mapping of T-cell epitopes in HEV proteins may prove useful for designing HEV vaccines and for studying the immunopathogenesis of hepatitis E.

Hepatitis C virus-related fibrosing cholestatic hepatitis in a renal transplant recipient

Fibrosing cholestatic hepatitis (FCH) is a severe and progressive form of liver dysfunction seen in organ transplant recipients and immunosuppressed patients; it is usually associated with hepatitis B virus infection. We report 36-year-old man, a renal transplant recipient, also developed FCH with hepatitis C virus infection and succumbed to it.

Mucinous cystadenoma of the ovary in perimenarchal girls

Ovarian masses in children are an uncommon occurrence. They represent less than 2% of all tumours in girls less than 16 years of age. Mucinous tumours of the ovary occur principally in middle adult life and are extremely rare prior to menarche. To the best of our knowledge, there are only 13 previous cases of benign mucinous cystadenoma (MCA) of the ovary in perimenarchal girls reported in the literature. We present six cases of this rare tumour. We reviewed the charts of six patients who presented with large MCA of the ovary. The patient's ages ranged from 13 to 14 years (mean 13.6 years). Two were premenarchal and four were within 1 year of menarche. All children presented with marked abdominal distension and discomfort. Except for one child who had ultrasound scan alone, all the others had either CT or MRI scan as well. Ultrasound demonstrated a large multiloculated cystic mass arising from the pelvis reaching the level of the xiphoid. CT demonstrated an enormous mass occupying almost the entire abdomen. The mass was partly solid, partly cystic and the cystic elements were multiloculated in all patients. Three patients demonstrated contralateral hydronephrosis on imaging. Laparotomy revealed a tumour arising from the left ovary in five patients and from the right ovary in one. Several litres of fluid were aspirated in order to deliver the tumour from the abdomen. All patients underwent oophorectomy or salpingo-oophorectomy. Histology revealed benign MCA of the ovary in all cases. On follow up, ranging from 2.4 to 5 years, all patients were well with no evidence of recurrence. MCA in perimenarchal girls usually affects the left ovary. Although this tumour is rare, this diagnosis should be considered in 11 to 15-year-old girls presenting with a very large abdominal mass.

Risk Factors of Hepatotoxicity During Anti-tuberculosis Treatment

BACKGROUND

Antituberculosis treatment (ATT) induced hepato-toxicity is common, but risk factors predicting its development are poorly understood. The present study evaluates the clinical risk factors predicting the development of hepatotoxicity in Indian patients with tuberculosis on antituberculosis treatment.

METHODS

Three groups of patients were studied at three service hospitals over a 3 year period from 2000-2002. Patients given ATT were followed up with monthly LFTs. Consecutive patients who developed Liver dysfunction (rise in SGPT > 5 times upper limit of normal) were studied, along with matched controls who did not. Markers for hepatitis B were also noted in these patients once in 6 months. A third group of patients who did not receive ATT but were HBsAg positive, were also similarly followed up. The possible association of age and sex of the patient, alcoholism, unrecognized chronic liver disease, hepatitis B virus carrier status and nutritional status with ATT-induced hepatitis was assessed. Statistical analysis was carried out by Chi square test/Fisher's exact test using WHO provided software Epi Info 6. Sixty-nine patients with ATT-induced hepatotoxicity were prospectively studied. In addition 128 patients on anti-tuberculosis drugs without hepatotoxicity and 39 HBsAg carriers not on ATT were followed up for 1 year.

RESULTS

Age, Sex, history of alcohol intake and BMI were not found to be related to development of hepatotoxicity. Presence of HBV infection or an underlying silent chronic liver disease were found to significantly increase the risk of development of ATT-induced hepatotoxicity. Continuation of ATT after development of jaundice was associated with a high fatality rate. It was possible to re-introduce isoniazid in 96% and rifampicin in 88% of patients with ATT induced hepatotoxicity.

CONCLUSION

ATT-induced hepatitis is common and is potentially fatal. It is likely to occur in those with underlying silent chronic liver disease, HBV infection and have been given ATT without a definite evidence of tuberculosis. Discontinuation of ATT leads to rapid recovery in most cases and drugs can safely be introduced after recovery in a majority of cases.

Differences in nitrergic innervation of the developing chick cloaca and colorectum

The intrinsic innervation of the developing gut has long been a subject of investigation, but little is known regarding that of the embryonic cloaca. The cloaca, like the rest of the gastrointestinal tract, is intrinsically innervated by the enteric nervous system. Nitrergic neurons and fibres make up a large part of this system, thus, their distribution provides us with a useful insight into its development. Cloacal and colorectal tissue specimens were removed from chick embryos at embryonic days 11 (E11), E15 and E19. NADPH-diaphorase (NADPH-d) histochemistry was carried out using whole mount tissue preparations. Ganglia density, the number of NADPH-d-positive cells per ganglia in the myenteric plexus and cell size were calculated and statistical analysis was performed to compare both regions of the gut (P<0.001). There were significant differences in the ganglia density in the cloaca compared to the colorectum at E11 (P<0.05) and E15 (P<0.01), with the colorectum having a much denser network. In both the cloaca and the colorectum, ganglia density significantly decreased with age (P<0.001), while significant differences were observed in the number of NADPH-d-positive cells per ganglia in both regions through development. Total cell size was similar in both the cloaca and colorectum at each stage and increased in both regions through development, predominantly due to an increase in the cytoplasm. Results reveal striking differences in innervation between the chick embryo cloaca and colorectum. The sparse network of innervation evident within the cloaca in contrast to the dense network within the colorectum emphasizes the individuality of both regions. These results highlight the need for a further in-depth analysis of the enteric nervous system's development within the embryonic cloaca.

The effect of vagal neural crest ablation on the chick embryo cloaca

The cloaca, the caudal limit of the avian gastrointestinal tract, acts as a collecting chamber into which the gastrointestinal, urinary, and genital tracts discharge. It is intrinsically innervated by the enteric nervous system, which is derived from neural crest emigres that migrate from the vagal and sacral regions of the neural tube. Abnormal cloacal development can cause a number of anorectal anomalies, including persistent cloaca. Ablation of the vagal neural crest has previously been shown to result in an aganglionic hindgut to the extent of the colorectum. The aim of our study was to investigate the effect of vagal neural crest ablation on the cloaca, the limit of the hindgut in the developing chick embryo. Chick embryos were incubated until the 10-12 somite stage. The vagal neural tube corresponding to the level of somites 3-6 was then ablated, and eggs were incubated until harvested on embryonic day 11 (E11). Whole chick embryos were fixed, embedded in paraffin, and sectioned. Immunohistochemistry was then carried out using the HNK-1 monoclonal antibody to label neural crest cells, and results were assessed by light microscopy. Vagal neural crest ablation resulted in a dramatic decrease in the number of neural crest cells colonizing the chick embryo cloaca compared with control embryos. Ablated embryos contained only a small number of HNK-1-positive neural crest cells, which were scattered within the myenteric plexus in a disorganised pattern. Hypoganglionosis was also evident in other regions of the hindgut in ablated embryos. Ablation of the vagal neural crest results in a hypoganglionic cloaca in addition to hypoganglionosis of the hindgut. These results suggest that the cloaca is largely innervated by vagal neural crest emigres. Further studies involving quail-chick chimeras to investigate the exact contribution provided by both vagal and sacral neural crest cells to the cloaca should increase our understanding of the pathophysiology of conditions like persistent cloaca.

Regional differences in nitrergic neuronal density in the developing porcine urinary bladder

Nitric oxide (NO) is involved in normal bladder physiology by regulating local arteriolar tone and smooth muscle relaxation and modulating the production of extracellular matrix proteins in vitro. Little information is available regarding the nitrergic innervation of the bladder during development. In this study we investigated the changes in density and morphology of the intramural nitrergic neurons of the porcine urinary bladder during development using whole-mount preparation. Bladder specimens were obtained from porcine foetuses of gestational age 60 days (n=5) and 90 days (n=5) and from newborn piglets (n=5) after perfusion fixation. Bladders were divided into base, body, and dome. Whole-mount preparation using NADPH-diaphorase (NADPH-d) histochemistry was used to visualize nitrergic innervation of the urinary bladders and to measure density of NADPH-positive ganglia (including single neurons), number of NADPH-d positive neurons per ganglion, and size of individual neurons. One-way ANOVA and chi-square tests were used for statistical analysis with a p-value <0.05 considered statistically significant. NADPH-d positive ganglia were numerous in the muscular layer of all three age groups. At E60, ganglion density was significantly higher in the body (mean 880/cm(2)) than in the dome (397/cm(2)) or the base (676/cm(2)). The ganglion density significantly decreased with age. The number of NADPH-d positive neurons per ganglion increased significantly between E90 and birth (p<0.01). A marked increase in the size of individual neurons over time was also seen (p<0.001), predominantly due to an increase in cytoplasm. Our data on whole-mount preparations demonstrate that significant maturation in nitrergic neuronal density and morphology occurs in the porcine urinary bladder, at least until birth.

Bilateral megaureters in the Adriamycin rat model

Congenital obstructive uropathy is associated with significant morbidity and mortality in the human neonate. The pathophysiology of congenital obstructive uropathy is poorly understood. There are very few experimental models of prenatal obstruction of the urinary tract, except in the fetal lamb or inbred rats. Prenatal exposure to Adriamycin in a rat model leads to a spectrum of malformations including urinary tract anomalies. We hypothesized that Adriamycin administration during a particular time frame could yield a high incidence of urinary tract anomalies and therefore designed this study to investigate the rates of urinary tract anomalies at different windows of Adriamycin injection in rat embryos. Adriamycin (1.75 mg/kg) was administered intraperitoneally to pregnant rats at different times from days 6 to 10 of gestation. Control animals were given saline. Embryos recovered on gestational day 21 by cesarean section were examined for urinary tract anomalies, and malformations were noted. Sections were then processed for paraffin embedding, sectioned at 5 mum, and stained with hematoxylin and eosin for histological examination. Anomalies of the urinary tract occurred maximally following Adriamycin administration on days 7, 8, and 9 of gestation (91.6%) compared with 16% of controls. The most common urinary tract anomaly in the Adriamycin group was bilateral megaureters with a hypoplastic bladder (81%). Other anomalies included unilateral or bilateral ureterohydronephrosis with a normal-sized bladder, duplex kidney, and unilateral or bilateral renal agenesis. In conclusion, the critical embryologic window for the development of bilateral megaureters with a small bladder in the Adriamycin rat model occurs following Adriamycin administration on gestational days 7-9. This simple experimental model of bilateral megaureter may allow further research into the pathophysiology of this condition.