Development of Risk-Taking, Perspective-Taking, and Inhibitory Control During Adolescence

Structural and functional brain development is thought to lead to different developmental progressions of cognitive control, risk/reward processing, and social cognition during adolescence. We compared these abilities in a cross-sectional sample of 90 adolescents aged 12, 15, or 17 years old, using computerized measures of inhibitory control (Go/No-Go task), risk-taking (Balloon Analogue Risk task), and social perspective-taking (Director task). Fifteen-year-olds exhibited better inhibitory control than 12-year-olds, while 17-year-olds exhibited greater perspective-taking than younger adolescents. Risk-taking was greater in older adolescents than 12-year-olds when controlling for inhibitory control. These findings are consistent with earlier findings obtained in separate samples.

Gram-negative organisms in peritoneal dialysis peritonitis: an early indication for surgery in patients with haemolytic uraemic syndrome?

PURPOSE

Haemolytic uraemic syndrome (HUS) is the commonest childhood cause of acute renal failure. Peritoneal dialysis peritonitis (PDP) is a well-recognised complication, with some children requiring surgical intervention (SI). The aim of this study is to determine whether the presence of enteric organisms in cases of PDP might predict the need for SI.

METHODS

Retrospective, 5-year (2009-2014) case note review of all HUS cases requiring PD presenting to a single centre. Mann-Whitney U test was used for continuous non-parametric data and χ (2) for categorical data.

RESULTS

48 children required PD for HUS, 18/48 (38 %) developed PDP and of these 5/18 (28 %) required SI (subtotal colectomy n = 4, small bowel resection n = 1). Peritoneal fluid was cultured as part of the work-up for PDP. The presence of enteric organisms was associated with a 10.4 fold relative risk of requiring surgery (p = 0.02, 95 % CI 1.5-71.9), with 4/5 of these patients requiring surgery (median 17 days post-culture result). Only 1/13 patients not requiring surgery grew gram-negative bacteria.

CONCLUSION

The presence of enteric bacteria in patients with PDP significantly decreases the chances of successful conservative management. In these patients early involvement of the surgical team is essential with a low threshold for SI.

Ileocaecal valve: how important is it?

PURPOSE

Our aim was to investigate the importance of the ileocaecal valve and its reconstruction in patients that are not suffering from short bowel syndrome and Crohn's disease.

METHODS

Casenotes of 99 children with hemicolectomy and 24 children with terminal ileal resection were reviewed and sorted into three groups. Group 1: ileocaecal valve resection (limited hemicolectomy), Group 2: hemicolectomy, Group 3: terminal ileal resection between 10 and 25 cm. Patients with Crohn's, short bowel syndrome and incomplete follow-up were excluded.

RESULTS

Chronic diarrhoea was documented in 7/26 cases (27%) in Group 1, 6/23 patients (26%) in Group 2, and none of the 13 patients had diarrhoea in Group 3. Pearson Chi-square test showed significant difference between Group 1 and Group 3 (p = 0.038) and between Group 2 and Group 3 (p = 0.043). But there was no significant difference between Group 1 and Group 2 (p = 0.947).

CONCLUSION

Chronic diarrhoea is a significant complication after limited hemicolectomy not only in Crohn's disease and short bowel syndrome. This is likely to originate from the loss of the ileocaecal valve itself rather than the loss of the ileal or colonic segment. Our results justify attempts to reconstruct the ileocaecal valve.

Thymectomy for inducing remission in juvenile myasthenia gravis

PURPOSE

The aim of this study was to determine the efficacy of thymectomy to induce remission in juvenile myasthenia gravis.

METHODS

A retrospective review of all patients undergoing a thymectomy for the treatment of juvenile myasthenia gravis was performed at a single tertiary referral centre between 1997 and 2009 (N = 8). All cases were moderate to severe cases (Osserman stage ≥ 2a). All operations were open. Median follow-up was 18 months (range 1-77). Postoperative progress was assessed using the De Filippi classification of remission.

MAIN RESULTS

Only two minor complications were reported. Mean operative time was 120 min (range 80-290 min). Mean postoperative stay was 17 days (range 3-52 days). Remission was observed in 5 of 8 patients (62%) at last known follow up.

CONCLUSIONS

Spontaneous remission rates for myasthenia gravis are quoted to be between 20 and 29% while remission rates following thymectomy are 29-68% at 3 years. Although not all of our patients have had 3 years of follow up-the remission rate of 62% demonstrated by this study is encouraging. If reproducible over a larger series this provides evidence of the efficacy of thymectomy for treating juvenile myasthenia gravis in selected patients.

Laparostomy closure in stage 4S neuroblastoma

Laparostomy in children is a rare procedure, and there is little in the literature as to the best method for closure in children with an open abdomen. We describe 2 cases with stage 4S neuroblastoma that required emergency decompressive laparostomy. Both cases highlight advantages and disadvantages with known techniques for achieving skin and fascia closure. We believe this to be the first report of a combination of extracellular matrix mesh and vacuum therapy for successful fascial and skin closure in stage 4S neuroblastoma.

Pancreatic tissue in congenital segmental dilatation of intestine: case presentation and recommendation for treatment

Segmental dilatation of intestine (SDI) is a very uncommon condition affecting children. The case that we present suggests that SDI may have may histologic findings in common with vitellointestinal remnants. A limited resection or other minimal procedure to preserve bowel length is usually undertaken for SDI. However, this case illustrates that the dilated segments of small bowel should be completely excised, in the same fashion as for vitellointestinal duct remnants, because of the possible presence of ectopic gastric mucosa and exocrine pancreatic tissue.

Conservative management of bilateral Sertoli cell tumors of the testicle in association with the Carney complex: a case report

Large cell calcifying Sertoli cell tumor of the testicle is a rare, hormonally active sex cord-stromal tumor seen in patients with Carney complex. When such tumors occur bilaterally, treatment options for preserving fertility and addressing the secondary effects of excess hormone production must be considered. The availability of specific antiestrogen drugs means that bilateral orchiectomy for this benign tumor may no longer be warranted. Testicular-sparing surgery and advances in reproductive technology may also improve the overall prognosis for fertility. Gynecomastia in prepubescent boys can be emotionally very distressing. Approximately two thirds of teenaged boys will develop some degree of breast enlargement that spontaneously regresses as testosterone levels rise (Ill Med J 1938;73:113). In all cases, a thorough history and physical examination are required to exclude nonphysiologic causes such as drugs, pulmonary disease, chronic liver disease, exogenous estrogens, and estrogen-producing tumors (Seashore J. Disorders of the breast. In: Rowe MI, O'Neill JA, Grosfeld JL et al, editors. Pediatric surgery, 5th ed. St Louis (MO): Mosby Year Book, 1998). We report on a child who presented with a 2-year history of gynecomastia with associated bilateral testicular swellings and discuss a novel treatment strategy for managing bilateral testicular tumors in the context of the Carney complex.

Asymmetric reduction of alpha, beta-unsaturated ketone to (R) allylic alcohol by Candida chilensis

A pilot scale whole cell process was developed for the enantioselective 1,2-reduction of prochiral alpha,beta-unsaturated ketone to (R) allylic alcohol using Candida chilensis. Initial development showed high enantiomeric excess (EE > 95%) but low product yield (10%). Process development, using a combination of statistically designed screening and optimization experiments, improved the desired alcohol yield to 90%. The fermentation growth stage, particularly medium composition and growth pH, had a significant impact on the bioconversion while process characterization identified diverse challenges including the presence of multiple enzymes, substrate/product toxicity, and biphasic cellular morphology. Manipulating the fermentation media allowed control of the whole cell morphology to a predominantly unicellular broth, away from the viscous pseudohyphae, which were detrimental to the bioconversion. The activity of a competing enzyme, which produced the undesired saturated ketone and (R) saturated alcohol, was minimized to < or =5% by controlling the reaction pH, temperature, substrate concentration, and biomass level. Despite the toxicity effects limiting the volumetric productivity, a reproducible and scaleable process was demonstrated at pilot scale with high enantioselectivity (EE > 95%) and overall yield greater than 80%. This was the preferred route compared to a partially purified process using ultra centrifugation, which led to improved volumetric productivity but reduced yield (g/day). The whole cell approach proved to be a valuable alternative to chemical reduction routes, as an intermediate step for the asymmetric synthesis of an integrin receptor antagonist for the inhibition of bone resorption and treatment of osteoporosis.

Anti-diabetic activity of Aloe excelsa

OBJECTIVE

To investigate the effect of Aloe excelsa powder on diabetes.

DESIGN

The experiment was carried out in the laboratory on both normal and diabetic rats. Diabetes was induced in the rats by using streptozotocin. Thereafter, blood samples were taken from both the normal and diabetic rats and the sugar levels measured by using the Accutrend Alpha blood glucose monitoring kit.

SETTING

The experiment was conducted in the laboratory in the Faculty of Medicine at the University of Zimbabwe.

SUBJECTS

A total of 280 male albino rats weighing 250 g on average were used. They were obtained from the Animal House of the Medical School at the University of Zimbabwe.

MAIN OUTCOME MEASURES

Reduction in sugar levels.

RESULTS

The Aloe excelsa powder produced a dose-dependent reduction in the blood glucose in blood glucose levels. It also compared well with the effect of insulin.

CONCLUSION

This study shows that Aloe excelsa has significant activity on glucose levels in rats and this, therefore, confirms the claims by traditional healers that this plant has anti-diabetic effects.

Sialoblastoma

Tumours of the salivary gland are very uncommon in children. We present a case of sialoblastoma, a very rare congenital salivary-gland tumour, initially recognised on antenatal ultrasound. After histological diagnosis, a superficial parotidectomy was performed at 21 days of age with preservation of the facial nerve. There is no recurrence at2 years.

Ligand-induced recruitment of a histone deacetylase in the negative-feedback regulation of the thyrotropin beta gene

We have investigated ligand-dependent negative regulation of the thyroid-stimulating hormone beta (TSHbeta) gene. Thyroid hormone (T3) markedly repressed activity of the TSHbeta promoter that had been stably integrated into GH(3 )pituitary cells, through the conserved negative regulatory element (NRE) in the promoter. By DNA affinity binding assay, we show that the NRE constitutively binds to the histone deacetylase 1 (HDAC1) present in GH(3 )cells. Significantly, upon addition of T3, the NRE further recruited the thyroid hormone receptor (TRbeta) and another deacetylase, HDAC2. This recruitment coincided with an alteration of in vivo chromatin structure, as revealed by changes in restriction site accessibility. Supporting the direct interaction between TR and HDAC, in vitro assays showed that TR, through its DNA binding domain, strongly bound to HDAC2. Consistent with the role for HDACs in negative regulation, an inhibitor of the enzymes, trichostatin A, attenuated T3-dependent promoter repression. We suggest that ligand-dependent histone deacetylase recruitment is a mechanism of the negative-feedback regulation, a critical function of the pituitary-thyroid axis.

Expression of CD44 by rhabdomyosarcoma: a new prognostic marker?

The expression pattern of CD44 standard and variant isoforms are prognostically significant in a number of malignancies. The aim of this study was to evaluate the role of the standard isoform of CD44 in predicting the clinical behaviour of rhabdomyosarcoma. Immunohistochemical analysis of CD44 was undertaken using a panel of antibodies recognizing the three core domains of the CD44 molecule. Labelling was repeated in triplicate and reported blind with respect to histological type and outcome. Tumours were characterized as positive in more than 60% of tumour cells labelled and negative if less than 40% of tumour cells labelled. Tumours with 40-60% of tumour cells labelling were considered indeterminate. Eleven of 20 favourable histology tumours were positive for CD44 compared with one of seven unfavourable tumours (P = 0.07). Eleven of 12 patients with CD44-positive tumours are alive in first remission compared with five of 15 CD44-negative tumours (P = 0.001). Expression of CD44 correlates directly with prognosis; however, larger studies are required so that multivariate analysis can be undertaken.

Superior mesenteric artery syndrome presenting with acute massive gastric dilatation

A 14-year-old girl presenting with acute massive gastric dilatation secondary to duodenal obstruction by the superior mesenteric artery is described. The diagnosis was facilitated by contrast-enhanced abdominal computerized tomography. She was successfully treated by gastrostomy and subsequent duodenal derotation. This unique presentation of the superior mesenteric artery syndrome is discussed.