Formation of aminosuccinyl derivative from β-phenacyl aspartyl peptides catalyzed by sodium thiophenoxide

In the solid-phase synthesis of cholecystokinin 30–33, Trp-Met-Asp-Phe- amide, the β-phenacyl ester was used to protect the β-carboxyl of aspartyl residue. The ester was cleaved, on the solid support, with a 1 M solution of sodium thiophenoxide in DMF, prior to ammonolysis. The product, after purification by countercurrent distribution, was identified as a mixture of isoasparaginyl and aspartyl peptides. A study of the deprotection step, with sodium thiophenoxide, on a model peptide (t-butyloxycarbonyl-β-phenacyl-aspartyl-phenylalanineamide) showed the rapid formation of the aminosuccinyl derivative, catalyzed by this reagent.     

DIURETIC RADIONUCLIDE RENOGRAPHY IN UPPER URINARY TRACT OBSTRUCTION

Diuretic renography using radioidine sodium hippurate and a frusemide stimulus was used to differentiate between obstructive and nonobstructive dilatation of the urinary tract. Information was recorded by a gamma camera on line to a computer. Sixty-seven uretero-renal units (URU) were studied in 33 patients with an average age of 9¹/₂ years. The diuretic renogram correctly indicated obstructions in 18 URU but gave false positive results in another five. Of these five, four had severely Impaired function. The renogram indicated nonobstruction in 49 URU, and gave false negative results in another two; of these two one patient had a duplex kidney with a poorly functioning ureteric segment and the other patient had gross reflux and megaureters. The diuretic renogram is useful in the investigation of equivocal upper urinary tract obstruction but may be unreliable in situations of inadequate renal function.     

Fluorometric microassay of trypsin and enteropeptidase in children — comparison with a titrimetic assay

Abstract Two trypsin assay methods for the estimation of this enzyme in duodenal fluid from children have been compared. Assay results for a fluorometric method based on the use of N-carbobenzoxy-diglycyl-L-arginyl-2-naphthylamide hydrochloride (GANA) as the trypsin substrate were found to correlate well (r=0.91, P<0.001) with those obtained with a much less sensitive titrimetric assay which used benzoylarginine ethylester hydrochloride (BAEE) as substrate. The higher sensitivity of the fluorometric assay has allowed accurate determination of trypsin activity in 10 μl aliquots of duodenal fluid. This low volume requirement makes the assay suitable for studies on infants of all ages and conserves duodenal fluid for use in other investigations often warranted during the assessment of childhood malabsorption.
The fluorometric assay has also been used to monitor the separation of enteropeptidase from trypsin(ogen) by chromatography on Sephacryl S-200 in samples of duodenal fluid from two children. Different proteolytic pathway deficiencies were confirmed in these children.     

An Analysis of 114 Consecutive Patients with Complete One-Year Follow-Up

This study assesses the clinical and electrode complications associated with the use of the epicardial screw-on electrode technique for permanent ventricular pacing. The records of 114 consecutive patients who received screw-on epicardial electrodes were analyzed in-hospital and at one year following implantation. We compared two techniques of implanting the screw-on electrode: 72 transmediastinal (TM) and 42 subxiphoid (SX) procedures. Baseline clinical inequalities were not apparent between the SX and TM patients. There was one operative death in the SX series and none among the TM patients. Total hospital mortality was 4% in the SX group and 2% in the TM group. In-hospital morbidity in the SX series (13/72-18%) was less than the TM group (14/42-33%), largely due to pleural entry and necessity for more frequent chest tube placement in TM patients. Electrode complications were low in both groups (3% in-hospital and 3% late; total 6/114, or 5%). Morbidity and mortality of these approaches to direct myocardial pacing remain noticeably higher than reported results of some transvenous series. Excellent electrode stability can be attained using the screw-on electrode, however, and the SX approach offers lower hospital morbidity than the TM method.     

HEXAHYDRO DERIVATIVE OF (D-MET2, PRO-NH25]-ENKEPHALIN GIVES RISE TO PHYSICAL DEPENDENCE

Filippi et al. (1979) have claimed that substitution of cyclohexylalanine for phenylalanine in leucine-enkephalin and its L-Ser³ derivative resulted in synthetic analogs which were non-addicting. We have examined the hexahydro derivative of [D-Mer², Pro-NH⁵₂]-enkephalin, a potent analgesic agent, to determine if dependence liability can be separated from short-term opiate actions after hydrogenation of the phenylalanine residue. In contrast to Filippi et al.'s observations, we found that the hexahydro derivative of [D-Met², Pro-NH⁵₂]-enkephalin gives rise to physical dependence and that its short-term potencies generally paralleled its long-term ability to produce physical dependence.     

ACHALASIA CARDIA: A REVIEW OF 100 CASES

Achalasia cardia is the commonest benign obstructive lesion of the oesophagus in India. We have reviewed 100 cases over a 20-year period. This is the largest series that has been reported from India. Some unusual features were observed. Males were more often affected than females in a ratio of 2.3:1. Children below the age of 10 years are not often affected, but we had 10 subjects in this age group. In our series dysphagia for solids has been the main presenting feature. Barium swallow X-ray studies of the oesophagus were diagnostic. The treatment of choice has been surgical, and a modified Heller's operation has been the chosen procedure. Our preference is for the thoracic approach. Postoperative complications were few. Long-term follow-up of 65 patients over a 19-year period revealed excellent results in SO patients (76.9%). good results in 10 (15.4%), and fair and poor results in two (3.1%) and three (4.6%)patient's respectively. The fair and poor results occurred in patients with recurrence of symptoms or stricture formation due to reflux oesophagitis. The excellent results, even on long-term follow-up, we believe are due to the adequate myotomy that was performed.