The effect of the cibarial armature on blood meal haemolysis of four anopheline mosquitoes

The cibarial armatures of Anopheles albitarsis Lynch Arribalzaga, A. aquasalis Curry, A. bellator Dyar & Knab and A. homunculus Komp are described for the first time. Ten to 15 minutes after blood feeding, higher levels of blood haemolysis were observed among A. bellator (14.9 percent) and A. homunculus (14 percent) mosquitoes which possessed type C cibarial armatures than among A. albitarsis (3.3 percent) and A. aquasalis (3.2 percent) which possessed type B cibarial armatures. In contrast, there were no significant differences among the four species in levels of extra-erythrocytic haemolysis when measured immediately after one hour. The blood processing physiology observed for the four anopheline species is discussed at the enzymatic, mechanical and taxonomic levels as it relates to innate vector competence (AU)

Obstruction of the alimentary tract in St. Vincent - abstract

This study assesses the aetiology and incidence of alimentary tract obstruction seen by a single surgeon from 1964 to 1985 in St. Vincent. The data were from the clinical and operation records, private museum and library of photographs, and X-ray pictures. Of 299 cases, 231 (77 percent) were acute and 68 (23 percent) chronic. The commonest acute obstruction was of the appendix by faecoliths or fibrosis, 53 percent; hernial obstruction constituted 15 percent, small bowel obstruction by bands 10 percent, intussusception 9 percent, atresia of the bowel 5 percent, obturation of the lumen 4 percent, congenital pyloric stenosis 3 percent and volvulus due to malrotation and in a mentally ill patient 0.4 percent each. Cancer was the commonest chronic cause, 46 percent; fibrotic pyloric stenosis 26 percent, infection 15 percent, oesophageal achalasia 6 percent, obturation of the lumen by faeces 4 percent, jejunal leiomyoma and oral teratoma 1 percent each. Congenital conditions were 9 percent of all cases (atresia accounting for 44 percent). Operations for alimentary tract obstruction were 11 percent of the 2, 727 abdominal operations performed in the 22 years. Noteworthy were the absence of obstruction in infantile umbilical herniae, 2 fatal cases of herniation of ileum through tears in the mesentery, 40 percent of intussusceptions betwee 4 and 43 years, frozen pelvis in actinomycosis, advanced oesophageal achalasia in an 18-year-old, mango bolus obstruction, and 3 tumours at rare sites - teratoma of the mouth, carcinoid of the pyloric canal and an ileal leiomyosarcoma. This study demonstrates the causes and incidence of alimentary tract obstruction in St. Vincent (AU)

The physiology of gastric secretion

The stomach secretes a number of substances, viz: (1)hydrochloric acid; (2) proteolytic enzymes - the pepsin group and gelatinase; (3) the hormone - gastrin; (4) intrinsic factor; (5) mucus; (6) blood group substances; and (7) a variety of anions and cations. The production and secretion of (1) to (5) are controlled according to the requirements of the body. This programme attempts to explain how these substances are produced and the mechanisms which control their secretion. (AU)

Nitrogen metabolism in the rat

The intermediary metabolism of 6 isotopic amino acids, 15N-aspartic acid, 15N-glutamic acid, 15N-alanine, 15N-glutamine (amide-15N), 15N-glycine and 15N-lysine (O-15N), and 15N-ammonium chloride were investigated. The aim of this study was to establish the precursor-product relationships existing between these amino acids, ammonia and urea in the amino-N pools of the major organs and tissue beds of the normal postprandial rat with the specific objective of following the movement of nitrogen to urea synthesis. It was hoped to ascertain whether glutamic acid played a central role in providing nitrogen for urea synthesis and whether there existed any relationship between 15N distribution patterns of the different isotopes and WBTP rates calculated from hepatic and renal urea-N enrichments. The method employed involved the administration of tracer quantities of the isotopes by the constant infusion technique and measuring the 15N excess of ammonia-N, glutamine amide-N, alanine-N, glutamate-N, aspartate-N and urea-N. It was found that nitrogen from 15N-alanine, 15N-aspartic acid and 15N-glutamic acid was distributed evenly in most of the amino-N pools studied. Nitrogen from the other four isotopes was distributed unevenly, preferentially to ammonia, glutamine amide and urea. 15N-glycine and 15N-lysine were only sparingly metabolised. WBPT rates obtained from urea-N enrichments were not affected by the nitrogen distribution patterns of the isotopes but by the extent to which they metabolised. WBPT rates calculated from ammonia-N enrichments were unduly affected by the extent to which each isotope contributed nitrogen to ammoniagenesis. Glutamic acid does not seem to be the precursor of both nitrogens used for urea synthesis. It supplies only one nitrogen. It is possible that urea is synthesised from an amino-N received via the glutamate to aspartate pathway and an amide-N received via the glutamine to ammonia to carbamyl phosphate pathway. Free ammonia entering the liver is first fixed as glutamine amide before being used for urea synthesis. (AU)