Antigenic structure of the hexacosapeptide melittin: evidence for three determinants, one with a helical conformation.

ELISA-based epitope analysis was performed using rabbit polyclonal antisera against melittin. Antigenic sites were found at the C-terminus, in the middle section and within the N-terminal helix. Antibodies against the helical segment could discriminate between two faces of the amphiphilic helix. The antigenic sites include the bulk of the melittin hexacosapeptide, which is synonymous with a very high epitope density.     

Sonographic and computerized tomography study of congenital choledochal cyst

In the neonatal period ultrasound and hepatobiliary functional scintigraphy are used to diagnose choledochal cysts. Initial sonography demonstrates hepatobiliary anatomy, hepatobiliary function is assessed by subsequent scintigraphy. The diagnosis can be confirmed by additional computed tomography as shown in this case report.     

Gastric outlet obstruction after long-term prostaglandin administration mimicking hypertrophic pyloric stenosis.

Prostaglandin E1 (PGE1) is widely used in neonates with cyanotic congenital heart disease who depend on the patency of the ductus arteriosus for oxygenation. Side effects of prostaglandin therapy are common and include respiratory depression, generalized flushing, and cardiovascular and neurological effects. Little is known about the complex effects on the gastrointestinal tract. We report on an infant with gastric outlet obstruction after long-term prostaglandin administration. At the age of 1 month, feeding problems developed with projectile vomiting. Ultrasonography showed progressive elongation of the antropyloric channel without wall thickening, which was causing gastric outlet obstruction. Three days after cardiac surgery and cessation of prostaglandin therapy, the infant fed normally and rapidly gained weight. The clinical signs in such patients can mimic hypertrophic pyloric stenosis. Therefore, the sonographic findings should not be confused with pyloric wall thickening to avoid a false diagnosis and unnecessary surgery. The symptoms diminish with cessation of the prostaglandin therapy after a corrective cardiac operation.     

Pharmacokinetics of peptide T in patients with Acquired Immunodeficiency Syndrome (AIDS)

1. The pharmacokinetics of Dalal-peptide T-NH2 (peptide T) was determined during phase I clinical trials in patients with acquired immunodeficiecy disease (AIDS) and AIDS related complex (ARC). Drug levels were determined by specific RIA, and in some cases with HPLC analysis, after intraveneous (i.v.) or intranasal (i.n.), via metered sprayer, administration.

2. The plasma kinetics appeared to be bi-phasic with a first compartment half-life of 30 to 60 minutes and a second plasma clearence rate of 4 to 6 hours, observed for both routes of administration. Peptide T, in one individual was confirmed to be present at 6 hrs in plasma, determined after HPLC isolation followed by specific RIA.

3. Bioavailabilty, determined for a 2 mg test dose in six individuals was 9.3 ± 6.9 nmol/L. Peak plasma levels of 41 ± 30 nmol/L after 10 mg i.n., 2.8 ± 5.9 nmol/L after 2mg i.n., and 0.13 ± 0.07 nmol/L after 0.4 mg i.n. were observed. In two individuals tested, peptide T was detected in CSF at levels 20% of the corresponding plasma level 90 and 145 minutes post i.v. administration. Peptide T was not detected in urine. I.N. administration was well tolerated for times up to 21 months.     

Recombinant interferon alfa-2a with or without vinblastine in metastatic renal cell carcinoma: results of a European multi-center phase III study.

A total of 178 patients with metastatic renal cell cancer were randomized to receive interferon alfa-2a (rIFN alfa-2a) or interferon alfa-2a+vinblastine (VLB). IFN alfa-2a was injected intramuscularly at a dose of 18 MIU 3 times a week and VLB was given intravenously at a dose of 0.1 mg/kg once every 3 weeks. The response rate was 11% for patients on monotherapy and 24% for those on combination treatment. The 5-year survival for 145 eligible patients was 9%, independently from the treatment arm. The performance status was significantly related to long-term prognosis, and 13% of the patients with performance status 0 were alive at 5 years, as compared to 6% and 0% for patients with a WHO grade of 1 and 2, respectively. The most frequent adverse events in both treatment arms were flu-like symptoms (95%), fatigue (70%) and gastrointestinal disturbances (68%). Leukopenia was observed more frequently with combination treatment (53%) than with IFN alfa-2a alone (30%). In conclusion, rIFN alfa-2a monotherapy at this dose and schedule has modest antitumor activity in metastatic renal cell cancer. The combination of rIFN alfa-2a+VLB results in a doubling of the response rate, but this does not translate into prolonged survival. Toxicity (except leukopenia) and tolerance were similar in both treatment arms.