The endocrine pancreas of the Cape fur seal, Arctocephalus pusillus (Schreber, 1776): an immunocytochemical study

The indirect peroxidase method was employed to study the endocrine pancreas of the Cape fur seal. Immunoreactivity to insulin was confined to the cores of the islets and the insulin cells were more abundant than the other endocrine cell types, which occurred mainly in the mantles of the islets. Of these, glucagon cells were the most numerous, followed by somatostatin and pancreatic polypeptide (PP) cells. The latter were observed in the mantles of the islets and scattered in the exocrine tissue of the duodenal lobe. The marked variation in the shape and the distribution of the endocrine cells in the mantles of the islets seen in the pancreas of the seal, seems to be typical of carnivorous species like the cat and dog.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

An immunohistochemical study of various peptide-containing endocrine cells and neurones at the equine ileocaecal junction

The ileocaecal junctions of 5 horses and 2 donkeys were examined by using antisera to the following peptides: somatostatin, glucagon, gastrin, neurotensin, vasoactive intestinal peptide (VIP), peptide histidine isoleucine (PHI), calcitonin gene-related peptide (CGRP), substance P (SP) and neuropeptide Y (NPY). Antisera to somatostatin, neurotensin and NPY demonstrated endocrine cells in the ileal- and caecal parts of the ileocaecal junction, while immunoreactivity for glucagon was demonstrated in endocrine cells of the ileal part only. Nerve cell bodies showing immunoreactivity to SP, VIP, CGRP and PHI were demonstrated in the myenteric and submucosal plexuses and were associated with small blood vessels in the submucosa of all the regions tested. Ramified nerve fibres in the submucosa immunoreactive to SP, VIP, CGRP and PHI extended to the mucosa and to small blood vessels in the submucosa. Nerve fibres showing immunoreactivity to SP, VIP and PHI extended to the circular smooth muscle layer of the ileocaecal junction.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Screening of the venoms of two Parabuthus scorpion species on isolated cardiomyocytes

Crude, diluted venoms of Parabuthus transvaalicus and P. granulatus were tested on isolated cardiomyocytes. Ventricular myocytes were subjected to hypercontractility tests and whole-cell voltage clamp. Both venoms had a profound influence on the hypercontractility of cardiomyocytes, which was markedly decreased when they were pre-absorbed with commercial antiserum. Whole-cell clamp results showed an increase in the sodium current, and a retardation of the time course of inactivation, implicating the presence of an a toxin in both venoms.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Association between personality factors and consulting specialty of practice of doctors at an academic hospital in Bloemfontein, South Africa

Background. Studies found an association between personality types and field of specialty. The current study could assist aspiring specialists in deciding which specialty they are best suited for by comparing their own personalities with the results.Objectives. To explore the personality characteristics of doctors in three consulting and four surgical specialties at an academic hospital in Bloemfontein, South Africa.Methods. In this analytical cross-sectional study, questionnaires, including the Zuckerman-Kuhlman Personality Questionnaire, were handed out. Overall, 58 consultants and senior registrars from the departments of Family Medicine, Paediatrics and Internal Medicine (response rate 71.6%) and 70 consultants and senior registrars from surgical specialties (response rate 60.3%) participated.Results. Family medicine had the lowest median score for impulsive sensation seeking (21.1%) and aggression-hostility (11.8%), and highest for parties and friends (33.3%). Paediatrics scored highest for neuroticism-anxiety (44.7%) and aggression-hostility (23.5%). Internal medicine scored highest for sociability (25.0%) and isolation intolerance (37.8%), and lowest for neuroticism-anxiety (36.8%) and activity (47.1%). Overall, the consulting group scored lower than the surgical group for impulsive sensation seeking, aggression-hostility, sociability and activity, and higher for neuroticism-anxiety.Conclusion. The study identified personality types of some specialties, and revealed differences between characteristics of local specialists compared with findings from studies elsewhere

Cardiotoxicity of the skin of the red-banded rubber frog, Phrynomerus bifasciatus (Smith 1847)

The skin of the red-banded rubber frog is said to secrete an unidentified toxin. Whole skin extract as well as HPLC fractions were tested for toxicity on viable, isolated cardiomyocytes. The skin extract and one of its fractions were shown to be cardiotoxic. Whole-cell clamping tests demonstrated that both extract and fraction interfered with the function of the potassium channels of the cardiomyocytes and that the toxic substance has an affinity for the IK₁ channels. Investigations are in progress to isolate and characterize the toxic substance.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.Medical Research Council. PU for CHE.mn201

A light microscopic and immunocytochemical study of the gastro-intestinal tract of the ostrich (Struthio camelus L.)

Although the histological features and endocrine cells of the gastro-intestinal tract of the chicken have been well studied, little is known about these features of the gut of the ostrich. The present study was undertaken to elucidate the histology and peptide-storing endocrine cells of the ostrich. As a rule the histological features of the gastro-intestinal tract of the ostrich corresponded to that of the fowl. However, certain differences were observed. The superficial proventricular glands were simple, branched tubular glands, while the deep proventricular glands were restricted to a slipper-shaped area and extended into the muscularis mucosae. The gizzard had a variably developed muscularis mucosae, a feature that seems to be unique to the ostrich. The villi of the small intestine were long and branched profusely, forming a labyrinthine surface. No Paneth cells were observed. The mucosa of the ceca and the first part of the rectum was thrown in large circular folds, forming a compressed spiral. Numerous melanocytes were seen in the submucosa and the connective tissue around the blood vessels of the muscle layers at the tips of the ceca. A well developed subserosa was present throughout the gastro-intestinal tract. Endocrine cells immunoreactive to somatostatin, glucagon, gastrin, bombesin, neurotensin, substance P and pancreatic polypeptide were detected in the gastro-intestinal tract of the ostrich. The topographical distribution of those endocrine cells immunoreactive to glucagon, bombesin, neurotensin and substance P differed from that of the chicken. The results of this investigation inferred that at least one of the gut peptides of the ostrich (secretin) to be structurally different from its counterparts in mammal and chicken. Molecular heterogeneity of somatostatin was observed in endocrine cells situated in the deep ventricular glands of the ostrich.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Distribution of endocrine cells in the gut of the impala (Aepyceros melampus)

Immunocytochemical methods were employed to demonstrate endocrine cells, containing peptides and serotonin, in the gut of the impala. Cells immunoreactive to serotonin, somatostatin, gastrin, cholecystokinin, glucagon, neurotensin, secretin, glucose-dependant insulinotropic peptide and motilin were detected. Antisera raised to substance P and pancreatic polypeptide failed to stain any cells. The distribution of these peptide-containing cells is more in line with the situation in sheep than other ruminants. In contrast, the distribution and abundance of serotonin cells in the gut of the impala parallels the situation seen in game herbivores.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

The oesophagus and stomach of the African elephant : a histological, immunocytochemical and immunofluorescence study

Histological, immunocytochemical and immunofluorescence methods were employed to study the oesophagus and stomach of the elephant. The histological findings were in line with the situation in monogastric species like swine and man. In the mucosa of the stomach, endocrine cells were immunoreactive to gastrin, somatostatin, chromogranin A and serotonin. Nerve cells immunoreactive to somatostatin, bombesin, VIP, PHI and CGRP were detected in the submucosal and myenteric plexus of the stomach. In the stomach, the absence of glucagon cells and the presence of endocrine cells immunoreactive to PYY, are in contrast to the situation in mammals and need further investigation. Small gastric ulcers were observed in some of the specimens.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201

Influence of lactation on the prolactin secreting cells of the hypophysis of impala (Aepyceros melampus): An immunocytochemical and computer image analysis study

Acute stress in the course of wildlife management has been intensively investigated. Chronic stress, on the contrary, has not been researched at all, probably due to the difficulty in measuring it as a result of the overriding effect of the physiological response to the restraining of wild animals. It was therefore decided to evaluate the use of immunocytochemistry, combined with computer image analysis to try and determine the magnitude of the structural changes of various hormone-secreting cells of the hypophysis. Since it was a pilot study to determine whether the combination of immunocytochemistry with computer image analysis could be of value to distinguish between two normally diverse groups, it was decided to compare the relative activity of prolactin secreting cells of lactating and nonlactating impala ewes. After transforming the prolactin immunoreactive area data by log10 to fall inside the parameters for kurtosis and skewness, a significant difference (P < 0,05, 5-% level, 2-tail) with the parametric t-test could be shown between the mean prolactin immunoreactive area of lactating (3,0751 µm2) and non-lactating (3,0467 µm2) ewes. However, the Pearson product moment (r= 0,03) showed that this difference may not be important for all practical reasons. This may be due to either sampling errors or limitations of computer image analysis, as it was often difficult to distinguish individual prolactin immunoreactive areas. Furthermore, a significant increase in the total prolactin immunoreactive areas of lactating ewes was also established. This technique, however, could distinguish between the hypophyses of lactating and non-lactating impala ewes, and with further refinement could be a useful tool in determining chronic stress in wildlife populations.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat v.9 was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

A light microscopical study of the intestinal tract of the Nile crocodile (Crocodylus niloticus, Laurenti 1768)

Although the histology of the intestinal tract of Crocodylus niloticus is touched on in overall studies on reptilian intestinal tract, a more comprehensive light microscopical study on this area is lacking. Specimens for histological examination were taken from the duodenum, the jejunum, the ileum and the rectum. The data obtained revealed that the mucosa is thrown into folds and simple, slightly branched tubular intestinal glands. The mucosal folds diminished in height and eventually disappeared upon reaching the ileorectal junction. The epithelium covering the folds and crypts was of the simple columnar type. Clear marginal cells, goblet cells and argentaffin cells were observed throughout the intestinal tract. No Paneth cells were seen in this study. The lamina propria was rich in lymphocytic infiltrations while the muscularis mucosa consisted mainly of an outer longitudinal layer, the inner circular layer being rudimentary or absent. The submucosa was extremely narrow, and the circular and longitudinal layers of the tunica muscularis contained distinct layers of dense fibrous connective tissue. The histology of the intestinal tract of C. niloticus is shown to be in line with the situation in crocodilians and also exhibits a resemblance to that of carnivorous mammals.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201