GABA induces behavioral and developmental metamorphosis in planktonic molluscan larvae

Swimming planktonic larvae of the marine gastropod mollusc Haliotis rufescens require exogenous GABA or its homologs for induction of their genetically programed behavioral and developmental metamorphosis to the adult form. This requirement is stereochemically specific and absolute; GABA at 10(-6) M is fully effective in the induction of cellular differentiation, proliferation and organogenesis. The kinetics of the development of larval competence for GABA induction, and of the early metamorphic processes induced by GABA, are described. Biochemical, histological and electron micrographic analyses suggest that cyclic AMP, calcium, and a glycopeptide secretion from the cephalic sensory complex may mediate transduction of the GABA signal in the control of behavioral and morphogenetic changes induced by this environmentally deployed transmitter substance. This first observation and characterization of a major role for GABA in the control of differentiation and development, and the experimentally tractable system in which these are demonstrated, are of significance for further biomedical research.

The use of internal and external vascular conduits for correction of D-transposition of the great arteries and double-outlet right ventricle with pulmonary atresia

Between 1967 and 1978, an 11-year-old boy had undergone 3 separate systemic-pulmonary artery shunt operations. Two of the 3 shunt operations failed. The patient was restudied because of progressive cyanosis and was diagnosed as having D-transposition of the great arteries and double-outlet right ventricle with pulmonary atresia. Repair was successfully accomplished with the use of an internal vascular conduit and an external vascular conduit with a glutaraldehyde-treated porcine valve. Four months after the corrective procedure, the patient's exercise tolerance had improved dramatically.

Medial deviation of the pelvic ureters after abdominoperineal resection of the rectum

Pre- and postoperative urograms of 47 patients undergoing abdominoperineal resection were reviewed for ureteral deviation and obstruction. Postoperative medial deviation occurred in 11 patients (23.4%). Both ureters were involved in six of these patients. Ureteral deviation was identified as early as 3 days after surgery. Obstruction of the ureters occurred in four patients and was due to tumor in three of these.

Extraosseous tumor uptake of 99m technetium phosphate compounds in children with abdominal neuroblastoma

Sixteen patients with abdominal neuroblastoma had 99m Technetium Phosphate Compounds (99m TC-PC) bone scans as a preoperative evaluation for metastatic disease. Ten patients (62%) had extraosseous tumor uptake while six patients (38%) did not. There was no difference in the incidence of tumor calcification, tumor necrosis or hydronephrosis in the two groups. However, VMA levels were significantly higher in the group with extraosseous tumor uptake. Various bone seeking radionuclides are compared to 99m TC-PC and possible mechanism for extraosseous uptake of such radionuclides are postulated. Awareness of the frequency of such uptake should reduce the possibility of errors in the interpretation of bone scans in patients with neuroblastoma.

The effect of surgical operation on venous plasma free amino acids

The effects of abdominal operation on the antecubital vein plasma amino acid concentration were examined. With four groups, each containing ten patients, factors such as severity of surgical operation, anesthesia, and postoperative nutrition were examined. Immediately after operation there is a fall in the plasma concentrations of most amino acids; the nonessential amino acids (glutamate, proline, glycine, alanine, histidine, and arginine) continue to fall during the 2 postoperative days, whereas the essential amino acids (isoleucine, leucine, phenylalanine, and lysine, with tyrosine) are at higher concentration at 48 hours than immediately after operation. Comparison of a group of patients undergoing an operation of moderate severity (vagotomy and pyloroplasty or cholecystectomy) with those having the more severe procedure of resection of aortic aneurysm with Dacron graft replacement suggests that these general changes in amino acid concentrations do not appear to be due to the severity of the operation, although cystine levels were lower, and phenylalanine levels were higher, in the graft-replacement group. The changes did not appear to be the result of anesthesia. Increasing the postoperative glucose intake was associated with higher plasma alanine and lower methionine levels. It is suggested that, in surgical patients, cystine and tyrosine may become essential amino acids and rises in phenylalanine and methionine indicate transient liver dysfunction. The data give support to the view that a high calorie intake after operation has a beneficial effect.

An ethology-based catalogue of facial/vocal behaviour in infancy

The ethological approach is suggested as a fruitful research strategy in the study of how infants express emotions. This approach led to the development of a large catalogue of facial/vocal behaviour which was used in the systematic observation of 75 girl and boy infants, who in the last quarter of the first year of life were placed in a series of standardized laboratory situations. Each of the 42 facial expressions contained in the catalogue is precisely defined according to the expressive elements of the brow, eyes, mouth and other facial regions. The vocalizations are also operationally defined. The possible ways that the facial expressions and vocalizations could be combined in the expression of emotional behaviour in infants are discussed.

Plasma amino acid changes in the postsurgical newborn during intravenous nutrition with a synthetic amino acid solution

Plasma amino acid concentrations during the therapeutic use of a crystalline amino acid solution are presented and discussed. In an attempt to avoid potentially dangerous hyperaminoacidemia, a maximum infusion rate of 350 mg nitrogen/kg/day was chosen. This resulted in the majority of the amino acids remaining within two standard deviations of normal mean,3 although levels of aspartate, glutamate, proline, valine, and isoleucine are in excess of this limit. No amino acid level is as much as one standard deviation below the mean, the lowest in this respect being lysine. A moderate increase in nitrogen provision is probably desirable to improve weight gain, but this solution would result in undesirable increases in these amino acid concentrations.

Reduction of Glyoxylate by Human Serum

Glyoxylate is enzymically reduced by human serum. Optimal concentrations of hydrogen ion, substrate, and coenzyme for this reduction by sera from healthy persons and from patients with disease of the heart or liver have been determined at 37°C. At this temperature, the reaction proceeds faster than with pyruvate or 2-oxobutyrate but more slowly than with hydroxypyruvate. Lactate dehydrogenase appears to be the enzyme involved.

Generalized glycogenosis in siblings

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