Insulin inhibition of hepatic cAMP-dependent protein kinase: decreased affinity of protein kinase for cAMP and possible differential regulation of intrachain sites 1 and 2.

In hepatocytes stimulated with 8-bromo-cAMP, insulin decreases the affinity of the cAMP-dependent protein kinase for cAMP, shifting the Ka without affecting the Vmax activity. This occurs under conditions where cyclic adenine nucleotide concentrations are unchanged. We report here that glycogenolysis stimulated by 8-(4-chlorophenylthio)-cAMP, an analog with 100 times tighter affinity than cAMP for the protein kinase regulatory subunit, was only slightly antagonized by insulin. The tight binding of this analog appears to overcome the protein kinase affinity change induced by insulin. The relative importance of the two intrachain cAMP binding sites of the cAMP-dependent protein kinase regulatory subunit was investigated by using analogs with relative selectivity for each site. Analogs exhibiting preferential binding to site 2 were far less sensitive to insulin antagonism than were analogs binding preferentially at site 1 and less well at site 2. No other property of these analogs, including the rate of hydrolysis by phosphodiesterase, the IC50 for phosphodiesterase, the Ka for protein kinase, or the type I versus type II kinase specificity, could account for the ability of insulin to antagonize glycogenolysis stimulated by these analogs. These data indicate that insulin may act to decrease the affinity of protein kinases for cAMP through a possible regulation of intrachain site 2 binding.     

Presence of the DRB4*0103102N null allele in different DRB1*04-positive individuals

The DRB4 gene encoding the DR53 antigen is present in DRB1*04-, DRB1*07- and DRB1*09-positive individuals. Eight allelic variants of DRB4 have been recognized, 5 resulting in an expressed DR53 antigen and 3 belonging to the null alleles. So far the DRB4*0103102N null allele had been found exclusively in individuals carrying the haplotype DR7,-DQ9. High-resolution typing of HLA class II by polymerase chain reaction using sequence-specific primers (PCR-SSP) and/or sequence-based typing of kidney patients and their families revealed the presence of the DRB4*0103102N null allele segregating with DRB1*04 and DQB1*03 in 4 different families. Three different haplotypes on which the null allele was located, were recognized by family studies: DRB1*0401, DQB1*0301; DRB1*0402, DQB1*0302 and DRB1*0404, DQB1*0302. Determination of the DR53 specificity of antisera reacting with DR53-positive individuals has always been difficult due to the simultaneous presence of DR4, 7 or 9. Identification of DR4-positive DR53-negative individuals as described here, provided the serological reactions with DR53-antisera and revealed the antibody specificities in the antisera used.     

Prenatal spontaneous closure of gastroschisis: a paradoxal evolution with poor outcome

Usually considered as an isolated malformation carrying a rather good postnatal prognosis, gastroschisis may however occasionally bear an unfavourable outcome despite reassuring ultrasound follow-up. We report on the case of a fetus with gastroschisis diagnosed at 13 weeks of gestation followed by a progressive bowel absorption and closure of the abdominal defect at 24 weeks, associated with a 10 to 15mm intra-abdominal bowel tract dilatation. At birth, the infant did not show any recognizable ventral wall defect or scar. Surgical exploration was decided due to the presence of a high level bowel tract occlusion associated with a dilated proximal jejunum on standard abdominal X-ray radiograph. Long-segment atresia of the midintestine without any possible surgical option was observed. The infant died at day 5.     

The effects of beta-adrenergic blockade on body composition in free-fed and diet-restricted rats

The effects of the non-selective beta-adrenergic blocking agent propranolol (known for its anti-lipolytic activity) on body composition were investigated in growing male rats on normal unrestricted diet (N = 7) and on diet restriction (N = 7, 95% of controls). Three animals in each group were injected i.p. with 30 mg propranolol per kg body weight (bw) dissolved in saline, 5 days/week. This dose attenuates exercising heart rate by 25% and exercise training-induced enzyme activity. The remaining animals received saline. Fat, glycogen, moisture and non-ether extractable residue were determined in the homogenized residue of the whole animal. After 9 weeks on the experimental regimen, bw gain was significantly lower in the diet restricted rats, whereas propranolol had no effect on the bw gain. The percentage of fat, moisture and non-ether extractable residue were unchanged by either propranolol or diet restriction. However, glycogen content was significantly lower in the beta-blocked rats either with or without diet restriction. These data indicated that neither beta-adrenergic blockade nor minimal diet restriction influences the percentage body fat, whereas body glycogen content is decreased under both conditions.     

Isolated tracheo-oesophageal fistula in neonates

INTRODUCTION: Congenital isolated tracheo-oesophageal fistulae without oesophageal atresia account for about 4% of tracheo-oesophageal malformations. An Otolaryngologist, even with a paediatric practice, is unlikely to treat a lot of cases during his career. We report 3 cases and discuss the investigations and management of the fistulae. PATIENTS AND METHODS: Three neonates with an isolated congenital tracheo-oesophageal fistula were treated between 1997 and 2002. We describe their presentation, investigation and treatment. We present radiology, endoscopic and surgical images for one case. RESULTS: The mean age at diagnosis of congenital isolated fistula was 6.7 days. In retrospect, the symptoms were usually present from birth. A barium swallow had demonstrated the tracheo-oesophageal fistula in 2 infants. In all three cases the fistula was clearly visualized by tracheoscopy. The most distal fistula was 25 millimetres below the true vocal cords. The closure of the fistula was made by cervicotomy in all cases. Our results are discussed with regards to the literature. CONCLUSION: Congenital tracheo-oesophageal fistulae are rare malformations. Diagnostic delay is common. Tracheo-oesophageal endoscopy is the investigation of choice. Good results are obtained with surgery treatment via a cervical approach. The management of such fistulae requires medical teams familiar with neonatal endoscopy and cervical surgery.     

Utilisation du robot en chirurgie oncologique pédiatrique

The video-assisted and mini-invasive surgery currently is a considerable development due to the technical progress of the instrumentation involved. It is particularly effective in oncologic surgery both in terms of diagnostic aim and in curative purpose. Many indications, however, need to be discussed with respect to the carcinologic surgery rules. The mini-invasive surgery presents a safe and increased quality of dissection limiting blood loss and allowing early beginning of a post-operative adjuvant treatment. The mini-invasive surgery, particularly the video-assisted surgery, seems to have a good scope in the oncologic surgical management. The place of the robotics surgery will improve for the indications where a better surgical precision will be required.     

Outcome of alimentary tract duplications operated on by minimally invasive surgery: a retrospective multicenter study by the GECI (Groupe d’Etude en Coeliochirurgie Infantile)

Background

Alimentary tract duplications (ATD) are a rare cause of intestinal obstruction in childhood. There are many case reports but few series about laparoscopy or thoracoscopy for ATD. The aim of our study was to report the outcome of minimally invasive surgery (MIS) for ATD.

Methods

This was a retrospective multicenter study from the GECI (Groupe d’Etude en Coeliochirurgie Infantile). We reviewed the charts of 114 patients operated on by MIS for ATD from 1994 to 2009.

Results

Sixty-two patients (54?%) had a prenatal diagnosis. Forty-nine patients (43?%) were symptomatic before surgery: 33 of those patients (63?%) with postnatal diagnosis compared to 16 (25?%) with prenatal diagnosis (P?P?P?=?0.01). The median follow-up was 3?months (range?=?1–120). Eighteen of the 27 patients who underwent partial surgery had an ultrasound examination during follow-up. Five (18?%) of them had macroscopic residue.

Conclusion

This study showed that MIS for ATD is feasible with a low rate of complications. Patients with prenatal diagnosis should have prompt surgery to prevent symptoms, despite a high rate of conversion in small infants.