Evidence for dopaminergic innervation on kitten retinal ganglion cells

Effects of iontophoretically applied dopamine and its receptor antagonists on physiologically identified retinal ganglion cells were studied in the optically intact eye of pentobarbitone anaesthetised kittens (7-9 weeks of age) and the results were compared with the effects obtained from adult cats (18-22 weeks of age). In both the adult and the kitten, dopamine had an inhibitory effect on visually evoked and spontaneous activity of the retinal ganglion cells, irrespective of cell type. However, unlike in the adult, the effects of dopamine in kittens were variable and not dependent on retinal eccentricity. In adult cells, only L-sulpiride (a potent D2 receptor antagonist) reduced the inhibitory effect of exogenous dopamine, whereas in kitten cells, both alpha-flupenthixol (a potent D1 receptor antagonist) and L-sulpiride did so. When applied alone, neither alpha-flupenthixol nor affected the activity of ganglion cells in adults, but in kittens both antagonists produced an excitatory effect in some cells. Physiologically active dopaminergic innervation seemed, therefore, to be present on the immature ganglion cells, but was subsequently 'eliminated' during the course of postnatal development. Furthermore, in immature cells, both D1 and D2 type receptors are present but only D2 receptors remain in adult. Therefore, there is a mismatch between dopamine receptors and dopamine in the adult retina and this mismatch may be the consequence of a developmental event.     

Extracellular Enzyme Activities by Basidiobolus and Conidiobolus Isolates on Solid Media./Extrazelluläre Enzymaktivitäten bei Basidiobolus- und Condiobolus-Isólaten auf festen Medien

Summary: Fifty-seven isolates of Basidiobolus from reptiles and amphibians, and 7 other obtained from the American Type Culture Collection (ATCC) in Maryland were studied for their extracellular enzyme activities on solid media. The Conidiobolus isolates studied included 4 recovered from Nigerian soil and additional 4 obtained from the ATCC All these isolates produced active extracellular lipase and protease and failed to exhibit amylase, deoxyribonuclease and ribonuclease activities. The significance of the findings is discussed.
Zusammenfassung: Fünfundsiebzig Basidiobolus-Isolate aus Reptilien und Amphibien und sieben weitere aus der American Type Culture Collection (ATCC) in Maryland wurden auf Aktivtäten extrazellulärer Enzyme auf festen Medien untersucht Die untersuchten Conidiobolus-Isolate schlossen vier aus nigerianischen Böden und vier weitere aus der ATCC ein. Alle Isolate zeigten extrazellulär Lipase- und Proteaseaktivität Amylase-, Desoxyribonuclease- und Ribonucleaseaktivität war jedoch nicht nachzuweisen. Die Bedeutung dieser Befunde wird diskutiert.     

Haemoglobin A1 and congenital malformation

Two hundred and thirty pregnancies were studied in 196 diabetic women. Seven women with babies found to have major malformations had a higher median first trimester haemoglobin A1 (12.9%) than the median HbA1 (10.8%) in those with normal babies (p = 0.06). No relationship was found between the occurrence of minor malformations and first trimester maternal haemoglobin A1. Two of the seven congenital malformations were diagnosed antenatally at a time when therapeutic abortion could be offered. Expert antenatal ultrasound scanning should be offered to all pregnant diabetic women as poor glycaemic control at the time of conception and organogenesis, as evidenced by raised first trimester HbA1, predisposes to congenital malformation.     

Computed tomographic investigation of serosal and intramural gastrointestinal pathology

Various cases are presented demonstrating the role of computed tomography (CT) in the assessment of serosal and bowel wall pathology. Reference is made to the morphology of the lesions. Illustrative examples of tumors, secondary malignant dissemination, irradiation injury to the gut, and intramural gas associated with ulcerative colitis, are all illustrated.     

Mother's understanding of allergen induced asthma

Forty-nine children with asthma and their mothers were interviewed regarding their knowledge of asthma, factors that precipitated attacks, and how they attempted to reduce the probability of an attack. Many mothers and children were well aware of factors that precipitated attacks, but took little positive action to reduce attacks. The data suggest that much ill-health in asthmatic children could be reduced by improving education available to mothers and children.     

Hirschsprung's disease in young adults

Hirschsprung's disease is rarely seen in the young adult, and presents unique problems in management because of the massive dilatation and hypertrophy that occur proximal to the aganglionic rectum or the rectosigmoid colon. The diagnosis, which may be suspected by barium enema, is confirmed by suction or full-thickness biopsy of the rectum that may be complemented by anal manometry. Based on our experience with eight patients, a two-stage surgical reconstruction is recommended, with a preliminary sigmoid colostomy through the normally innervated colon and an associated defunctionalized stoma constituting the initial operation. The distal colonic stoma permits cleansing of the caudal colon while the normally innervated proximal colon reverts to near normal caliber, usually within 2 to 6 months. This approach is in accord with the recommendation of Fairgrieve. Reconstruction using a Duhamel or Soave procedure has given good results. The Duhamel procedure seems preferable when a considerable discrepancy remains between the ganglionic and aganglionic segments of rectum.