Eighteen months general practice experience with urban practice nurses.

Experience working with practice nurses under the present urban practice nurse scheme is described very briefly. Financial matters are touched on briefly, as are points for and against the scheme. The personal conclusions reached with regard to patient acceptance, opportunities to practise a more preventive type of medicine and the relief of excessive pressures on the doctor, appear to make the continuance and extension of the scheme well worthwhile.     

Regional variation and control of cutaneous gas exchange in bullfrogs.

Previous work has demonstrated regional differences in morphometric diffusing capacity and cutaneous blood flow in anuran amphibians, leading to the prediction of a higher rate of cutaneous gas exchange across the dorsal skin of bullfrogs. Regionally measured cutaneous O2 and CO2 flux rates (MO2 and MCO2) support this prediction: flux rates across the dorsal skin are 15-32% greater than across the ventral skin in both pulmonary ventilating and apneic (anesthetized) bullfrogs. The rates of cutaneous gas exchange were much greater in anesthetized frogs; however, MO2 and MCO2 did not increase in parallel, which decreased the cutaneous respiratory exchange ratio from 3.5 to 2.0 in apneic frogs. Regional differentiation in cutaneous gas exchange suggests the possibility of independent regulation; however, cutaneous MCO2 varied little in response to changes in O2 content above these regions, neither in the anesthetized nor awake bullfrogs. The bullfrogs are able to increase whole body cutaneous gas flux during prolonged apnea but were not able to respond to changes in local O2 content.     

Peripheral retinal vasculature in normal Jamaican children.

A prospective study of the peripheral retinal vasculature in a Jamaican cohort of subjects with sickle cell disease has been in progress over a period of 12 years using fluorescein angiography. Various vascular patterns were identified but their significance was unclear since no comparable records were available in subjects of a similar age with normal (AA) haemoglobin genotype. Fluorescein retinal angioscopy and angiography have been performed in 76 haemoglobin AA controls participating in the cohort study. The peripheral retinal capillary bed could be seen and photographed in a limited portion of the temporal peripheral fundus in a majority of this group, and there was considerable variation in the vascular pattern which could be characterised. These observations allow deviations from normal to be identified in the retinal vasculature in subjects with sickle cell disease.     

Effect of longterm misoprostol coadministration with non-steroidal anti-inflammatory drugs: a histological study.

Prostaglandins are widely used in the prevention and healing of non-steroidal anti-inflammatory drug (NSAID) induced gastric and duodenal ulcers, but their longterm effect on the human gastric mucosa is unknown. This study assessed the effect of coadministration of prostaglandins with NSAIDs on the histology of the gastroduodenal mucosa. Histological appearances (using the Sydney system) of gastric biopsy specimens from 180 patients receiving longterm NSAID treatment of whom 90 had been receiving misoprostol (400-800 micrograms/day) for one to two years were studied. Both groups of patients were comparable with regard to clinical and demographic details. There was no significant difference (p > 0.1) in the prevalence of chronic gastritis (total, corpus or antrum only) between patients receiving (36 of 90 (40%)) or not receiving misoprostol (35 of 90 (39%)). Chronic gastritis was equally associated with the presence of Helicobacter pylori, 86% and 73% (p > 0.1), respectively, in the two groups. Significantly fewer patients receiving misoprostol had reactive gastritis than those receiving only NSAIDs (8 (9%) versus 27 (30%), p < 0.01). Reactive gastritis was not associated with H pylori. Thirty nine (43%) of the misoprostol treated patients had normal histology compared with 16 (18%) receiving only NSAIDs (p < 0.01). These results show two different patterns of gastric damage in patients receiving NSAIDs, namely chronic and reactive gastritis. Misoprostol treatment was associated with a significantly reduced prevalence of reactive gastritis and it is suggested that this, along with its antisecretory action, may explain the reduced prevalence of gastroduodenal lesions when coadministered with NSAIDs.     

The fate of free autogenous fascial grafts in the rabbit

Fascial grafts were taken from 34 New Zealand rabbits and implanted above and below the cranial periosteum in the same animal. They were placed as four-layered folded grafts and as single-layered grafts. When harvested from 6 to 14 months after transplantation, the multi-layered grafts and the single-layered grafts on bone had maintained their bulk but consisted histologically of only a retained collagen matrix with no viable cellular structure. The one-layered grafts on periosteum, however, retained their cellular make-up with normal vascularity and normal cellular structure when harvested at approximately the same intervals.     

Feline islands of Calleja complex: I. Cytoarchitectural organization and comparative anatomy

Cytoarchitectural analyses demonstrated that the islands of Calleja complex (ICC) is highly developed and discretely organized in the cat. The feline complex is clearly divided into morphological units, each containing a granular Callejal island and a population of satellite neurons. These ICC units change progressively in cytoarchitecture from the lateral to the medial edge of the olfactory tubercle. In particular, the islands flatten, sink into the tubercular molecular layer, and increase in cell density, while their satellite neurons increase in number and decrease in size. The lateromedial transformation was judged to take place in five stages, resulting in the successive appearance of lateral, lateral transitional, central, medial transitional, and medial ICC units. The first two unit types display prominently two additional components of the feline ICC-namely, clusters of dwarf cells and small pyramidal-like neurons constituting the densocellular layer cupping the base of lateral Callejal islands. All of the various types of ICC units contact the tubercular molecular layer via their dwarf and/or granule cell components, raising the possibility of direct olfactory input to the entire Callejal complex (apart from the isla magna). Output from the complex is presumed to arise from the satellite neurons, which are distinguished from adjoining cell populations by their close association with Callejal islands, typical chromophilic character, and relatively large size (15-42 micron in soma length). In the tubercular ICC, these neurons are most numerous immediately above Callejal islands in a fiber-rich zone continuous with the supratubercular zone and hence with the ventral pallidum. In the accumbal ICC, satellite neurons are most conspicuous in granule-cell-poor spaces within the isla magna, where many non-granular neurons are uncharacteristically small and chromophobic. The isla magna itself is unusual not only for its large size but for lateral extensions encircling a group of accumbal neurons far caudally. Such extensions are one of several indications that the isla magna is intimately associated with the nucleus accumbens. A comparative anatomical survey of the ICC in rats, cats, and macaque monkeys demonstrated a number of species differences. Of particular interest is the finding that the complex is unambiguously divided into discrete island-satellite cell units only in cats and macaques. In these species, the complex is also distinguished by a predominance of superficial islands and an especially prominent isla magna. ICC units, however, were most conspicuous in cats.