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Biomedical subjects

I D Wilson

Publications and source records attributed to I D Wilson.

At least 145 records · Page 8Linked to original sources
PubMed1982

Light microscopic morphometric analysis of rat ileal mucosa: II. Component quantitation of Paneth cells.

A quantitative light microscopic morphometric analysis of lysozyme- and IgA-containing Paneth cells within the ileal mucosa of physiologically manipulated and control (sham operation) animals was performed. The experimental groups of rats included animals raised in a gnotobiotic environment (microbial reduction) and animals with ileal self-filling blind (microbial proliferation) and Thiry-Vella (intestinal discontinuity) loops. The unlabeled antibody enzyme immunohistochemical localization technique was employed for the identification of intracellular lysozyme and IgA. Component quantitation was performed by use of a micrometer component quantitator. Marked Paneth cell hyperplasia was noted in association with gnotobiosis and with the Thiry-Vella fistula. This observation quantitatively confirms previous subjective impressions of increased Paneth cell differentiation in association with those physiologic states. Since the neurovascular component of the Thiry-Vella fistula is intact, the normal intraluminal succus entericus would appear to be involved in modulation of Paneth cell differentiation. The recognition of Paneth cell hyperplasia in association with the Thiry-Vella fistula suggests that this may be a useful experimental model for an evaluation of the life cycle and functional characteristics of this cell population. The results also revealed that no significant change in the volume percentage of Paneth cells and a decreased volume percentage of Paneth cells containing IgA occurred in association with the self-filling blind loop. A decreased volume percentage of IgA-containing immunocytes in association with the blind loop has previously been reported. The data are most consistent with the interpretation that the Paneth cell and immunocyte response to antigenic stimulation are interrelated and that the Paneth cell population has a restricted latitude of response to microbial proliferation.

Animals↗
PubMed1982

A quantitative morphometric analysis of rat ileal Thiry-Vella fistulae.

Controversy exists regarding the mechanism and degree of mucosal alterations occurring in defunctionalized segments of intestine. This study compares the results of a quantitative analysis of mucosal components, including Paneth cells and immunocytes, between in-continuity and defunctionalized (Thiry-Vella) segments of rat ileum. The micrometer component quantitator was used for the light microscopic morphometric analysis. Intracellular lysozyme and IgA were identified employing the unlabeled antibody enzyme immunohistochemical staining technique. The vol% of the ileal mucosal components of animals from the control group and from the in-continuity segments of the experimental group were comparable. Analysis of the Thiry-Vella fistulae, however, revealed a statistically significant decrease in the vol% of columnar epithelial cells and increase in the vol% of lysozyme-containing Paneth cells and interstitium of the lamina propria. Since Thiry-Vella fistulae are neurovascularly intact, mucosal alterations imply a causal relationship to interaction with chyme. The data suggest that chyme has both a stimulatory (on the columnar epithelium) and suppressive (on the the Paneth cell population) effect. The vol% of IgA-containing Paneth cells and the percentage of the lamina propria represented by IgA-containing immunocytes were also substantially decreased. Normally secretory IgA is the immunoglobulin of highest concentration intraluminally and among immunocytes within the lamina propria, presumably in response to local antigenic stimulation. The presence of immunoglobulin within Paneth cells may reflect the phagocytosis of immunoglobulin complexed antigens. The data suggest that the degree of local antigenic stimulation is decreased in Thiry-Vella fistulae.

Animals↗
PubMed1982

The contemporary natural history of mental disorder in old age.

A classificatory system for mental disorders in the elderly proposed by Roth in 1955 was examined in a contemporary population. Ninety per cent of patients could be allocated to the five psychosyndromes originally defined. Examination of outcome in the present sample, at six month and two years, showed important differences. The outlook for patients with paranoid psychoses showed an improvement though for those with affective illness (at 2 years) there was little change. Of special importance was the increased long-term survival of very elderly female patients with senile dementia. This, in conjunction with the general rise in admissions for mental disorders in the aged over the past 25 years, has considerable implications for the future development of psychiatric services for the elderly mentally ill.

Affective Disorders, Psychotic↗
PubMed1982

Cholinergic stimulation of immunoglobulin A secretion in rat intestine.

This study was undertaken to assess a possible role for cholinergic agents in the regulation of intestinal immunoglobulin A secretion. Intestinal loops, constructed in anesthetized rats, were perfused with phosphate buffered normal saline. Immunoglobulin A concentrations were measured by radioimmunoassay. When compared with the effect of normal saline in the same rats, intravenous injection of pilocarpine, 10 mg/kg, increased immunoglobulin A concentrations in perfusates from ileal loops (p less than 0.001). Qualitatively similar results were obtained with muscarine and bethanechol, from jejunal and colonic loops, and from unanesthetized rats. Immunoglobulin A concentrations increased four- to eightfold during maximal cholinergic stimulation. Atropine, 250 micrograms intravenously, completely blocked the effect of pilocarpine on immunoglobulin A secretion (p less than 0.005), and also inhibited basal intestinal immunoglobulin A secretion for 40 min after injection. As determined on 10%-40% sucrose density gradients, much of the immunoglobulin A secreted after cholinergic stimulation sedimented in the 11S range. These data indicate that intestinal secretion of immunoglobulin A is stimulated by the muscarinic effect of cholinergic agonists, and suggest that basal secretion of immunoglobulin A may be influenced by the parasympathetic nervous system.

Anesthesia, General↗
PubMed1980

Comparison of high-performance liquid chromatography and gas chromatography for the analysis of ecdysteroids.

High-performance liquid chromatography (HPLC) with ultraviolet absorption detection, and gas chromatography (GC) with an electron-capture detector have been compared for their convenience in the analysis of ecdysteroids in invertebrate tissues. Analysis by HPLC on reversed-phase materials, including C18, C22 and CN bonded phases, was explored for the separation of both polar ecdysteroids and some of their possible biosynthetic intermediates of lower polarity. The HPLC method was found to be rapid and easy to use, but less sensitive than GC with electron-capture detection. The greater sensitivity and selectivity of GC was found to be important for the more difficult analyses.

Animals↗
PubMed1980

Immunohistochemical identification of immunoglobulin A on ultrathin tissue sections.

Antigenic determinants of the heavy chain of immunoglobulin A (IgA) were identified within immunocytes by immunohistochemical techniques applied to ultrathin sections of rat ileal mucosa embedded in eposy resin. Successful localization of IgA depended upon the utilization of chemical fixatives containing paraformaldehyde or physical fixation employing a freeze-drying technique. Partial removal of the epoxy resin from the ultrathin tissue section with metallic alkoxide solutions or pretreatment with H2O2 was essential prior to the sequential application of the immunological reagents. IgA was associated with the rough endoplasmic reticulum (RER) and nuclear regions of immunocytes. These results are similar to those of other investigators employing immunochemical localization before embedment.

Animals↗
PubMed1980

Ileal Paneth cells and IgA system in rats with severe zinc deficiency: an immunohistochemical and morphological study.

Morphological abnormalities in Paneth cells occur in patients with acrodermatitis enteropathica, a hereditary disease associated with zinc deficiency; furthermore, rat Paneth cells contain large amounts of zinc. This study was conducted to assess the effect of severe zinc deficiency in Sprague-Dawley rats on various parameters of Paneth cells. Morphology at both the light microscopical and ultrastructural levels, Paneth cell numbers per crypt and the intracellular distribution of lysozyme were not altered by zinc deficiency. A weak correlation (r = +0.38, P = 0.05) was noted between ileal zinc concentration and numbers of IgA-containing Paneth cells per crypt. These findings indicate that the morphological abnormalities noted in human Paneth cells in patients with acrodermatitis enteropathica cannot be reproduced by experimental severe zinc deficiency in rats. Furthermore, these generally negative findings suggest that the severe diarrhoea often associated with zinc deficiency is not attributable to abnormalities induced in Paneth cells by zinc deficiency.

Animals↗
PubMed1980

Immunohistochemical localization of IgA and secretory component in rat liver.

IgA is transported from rat blood into bile. The localization of IgA and secretory component in rat liver was studied in order to facilitate understanding of this IgA transport. Both indirect immunofluorescence and unlabeled antibody enzyme histochemical techniques were used. Immunoglobulin A was found surrounding bile canaliculi, within bile duct epithelium, on or near the plasma membranes of hepatocytes, within the cytoplasm of a few intensely stained hepatocytes, within the cytoplasm of intensely reactive cells found in or adjacent to the sinusoids, and in sparsely distributed plasma cells. Reactivity for secretory component was present surrounding bile canaliculi, within bile duct epithelium, or or near the plasma membranes of hepatocytes and in the cytoplasm of hepatocytes. These findings are compatible with the hypothesis that immunoglobulin A is transported from blood to bile through hepatocytes by a process involving secretory component. Bile duct epithelium may also have a role in immunoglobulin A transport.

Animals↗
PubMed1979

Evidence against the presence of circulating immune complexes in chronic inflammatory bowel disease.

Several investigators have reported the presence of circulating immune complexes in serum from patients with Crohn's disease and chronic ulcerative colitis. Because previous assays employed conditions which might have caused immunoglobulin aggregates to form in vitro, thus falsely suggesting the presence of immune complexes in vivo, we tested inflammatory bowel disease sera for immune complexes using four assays designed to minimize in vitro immunoglobulin aggregation. In three assays immune complexes were not detectable, while in a fourth, the Clq precipitin test, positive reactions occurred. These precipitin reactions did not have characteristics of immune complexes. Our data suggest that circulating immune complexes are either not present in patients with inflammatory bowel disease or that they occur infrequently or in low concentration.

Antigen-Antibody Complex↗
PubMed1979

Studies on the nature of heat-labile anti-complementary activity in normal human serum.

Heat-labile anti-complementary activity (ACA) appears in normal human serum during storage or heating as endogenous haemolytic activity disappears. Following gel filtration of unheated serum, two peaks of heat-labile ACA are present. The ACA of both whole and fractionated serum has previously been attributed to the presence of heat-labile immunoglobulin aggregates or immune complexes. Our data demonstrate that the heavy peak of ACA obtained by gel filtration does not bind to 125I-C1q or to Raji cells, and that its effect is abolished to C1INH, suggesting that it represents C1 rather than immunoglobulin aggregates or immune complexes. The lighter peak of ACA in fractionated serum has the functional characteristics of C1s and free C1s is demonstrable in fractions containing this activity. The ACA of whole serum likewise has functional characteristics of C1. The anti-complementary effect of C1 on guinea-pig complement would not be evident in the complement fixation assay until most endogenous haemolytic activity in human serum has been inactivated, either by heat or by storage. C1INH only partially inhibits this ACA in serum or in solutions containing isolated C1 in high concentrations. These observations indicate that heat-labile ACA in whole or fractionated sera is due to the presence of C1 and C1s and that this activity cannot be taken as evidence for the presence of immune complexes.

Agammaglobulinemia↗