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Biomedical subjects

R Mann

Publications and source records attributed to R Mann.

At least 109 records · Page 6Linked to original sources
PubMed1989

Inflammatory bowel disease in rural sub-Saharan Africa: rarity of diagnosis in patients attending mission hospitals.

One hundred and eighteen missionaries working on 75 mission stations or hospitals in 24 sub-Saharan African countries provided information about their medical practice in the preceding year of 1981. Details were collected of the total number of patients seen and admitted during the year, and the number of cases of bloody diarrhoea, typhoid and inflammatory bowel disease. Over 1 million outpatients and about 190,000 inpatients were treated. These included 12,859 cases of bloody diarrhoea, of whom 1,914 had typhoid. Twenty-two cases of inflammatory bowel disease were also reported. Histological support was least available in West Africa and only 25% of hospitals had access to this facility. Nevertheless, the frequency with which inflammatory bowel disease in sub-Saharan Africa is difficult and limited by access to diagnostic facilities. It is likely to be some time before reliable estimates of the incidence and prevalence of Crohn's disease and ulcerative colitis in the rural African population can be made.

Africa, Eastern↗
PubMed1989

Ozone-induced inflammation in the lower airways of human subjects.

Although ozone (O3) has been shown to induce inflammation in the lungs of animals, very little is known about its inflammatory effects on humans. In this study, 11 healthy nonsmoking men, 18 to 35 yr of age (mean, 25.4 +/- 3.5), were exposed once to 0.4 ppm O3 and once to filtered air for 2 h with intermittent exercise. Eighteen hours later, bronchoalveolar lavage (BAL) was performed and the cells and fluid were analyzed for various indicators of inflammation. There was an 8.2-fold increase in the percentage of polymorphonuclear leukocytes (PMN) in the total cell population, and a small but significant decrease in the percentage of macrophages after exposure to O3. Immunoreactive neutrophil elastase often associated with inflammation and lung damage increased by 3.8-fold in the fluid while its activity increased 20.6-fold in the lavaged cells. A 2-fold increase in the levels of protein, albumin, and IgG suggested increased vascular permeability of the lung. Several biochemical markers that could act as chemotactic or regulatory factors in an inflammatory response were examined in the BAL fluid (BALF). The level of complement fragment C3 alpha was increased by 1.7-fold. The chemotactic leukotriene B4 was unchanged while prostaglandin E2 increased 2-fold. In contrast, three enzyme systems of phagocytes with potentially damaging effects on tissues and microbes, namely, NADPH-oxidase and the lysosomal enzymes acid phosphatase and beta-glucuronidase, were increased neither in the lavaged fluid nor cells. In addition, the amounts of fibrogenic-related molecules were assessed in BALF.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

[Efficacy of child and adolescent health protection in a district--approaches for studying the effectiveness].

The evaluation of the effectiveness of medical in particular preventive measures is an essential prerequisite for the determination of the priorities in the further improvement of medical care conceptions taking into account practical demands. Endeavours to define the terms of quality and effectiveness prove the difficulty of the problem. The description of approaches allows to deduce investigation approaches to judgements on the individual and collective state of health, and to coordinative and cooperative correlations in the medical care for children and adolescents for the purpose of optimizing a health care model on district level.

Adolescent↗
PubMed1988

An evaluation of the deterrent impact of Ontario's 12-hour licence suspension law.

The deterrent impact of Ontario's 12-hour licence suspension law, a law intended to mete out swift punishment is evaluated. A process model of deterrence is included. Time series analyses of the monthly log odds of number of positive B.A.C. fatalities over the number of negative B.A.C. fatalities indicated a small, short-term effect. The intermediate measures of four surveys of media coverage, Toronto residents, Ontario residents, and police forces supported these results, and affirmed the potential validity of the process model of deterrence. The results suggest that laws to increase the celerity and certainty of punishment will have little deterrent impact without enforcement and publicity of the new laws.

Accidents, Traffic↗
PubMed1988

Three-quarter prone approach to the pineal-tentorial region.

A three-quarter prone, operative approach to the pineal region is described: the three-quarter prone, operated-side-down position. This approach avoids the disadvantages of the approaches from other directions to this region and provides a comfortable position for the surgeon and assistant, minimal retraction of the parietal-occipital lobe, and access to the third ventricle, pineal region, midbrain, and superior vermis.

Brain Neoplasms↗
PubMed1988

Trauma associated with three- and four-wheeled all-terrain vehicles: is the four-wheeler an unrecognized health hazard?

All-terrain vehicle (ATV) accidents cause 7000 injuries and 20 deaths per month. In this prospective multicenter study comparing three- and four-wheelers, data were obtained on all ATV accident victims treated at 33 participating institutions in 13 Western Michigan counties from July-November, 1986 (N = 143) and on 51 accidents from the preceding 18 months. Of these 194 accidents, 29 per cent involved four-wheelers. In this 78 per cent male population (mean age 21), 23 per cent required hospitalization. One half of these victims sustained a fracture or dislocation and 14 per cent needed surgery. Thirteen per cent had serious neurologic injury. Average hospital bills were $294 for outpatients and $7669 for inpatients. Two thirds of the patients had some disability. Three fatalities were recorded. Analysis of the data showed the following: (1) the three-wheeled ATV design is significantly more unstable than that of the four-wheeler (P less than .001); (2) though more stable, the four-wheeled ATV was still associated with frequent accidents as severe as those involving three-wheelers; (3) riders under age 16 were more likely to be using their ATV improperly (P greater than .05) and had more severe injuries with a higher hospitalization rate, and (4) these ATV riders had inadequate training and protective gear. Lastly, recommendations are made that ATVs need their design flaws corrected for safer use, and that mandatory minimum age requirements, rider education, and helmet use should reduce injuries.

Accidents, Traffic↗
PubMed1987

Two classes of sympathetic nerves with different dopa decarboxylase immunoreactivities exist in dog vas deferens.

To determine whether dihydroxyphenylalanine (DOPA) decarboxylase (DDC) activity in the terminal regions of noradrenergic axons varies with axonal length, we compared the pattern of immunohistochemical staining for DDC in the 'short' terminal nerves of dog vas deferens with that in the 'long' nerves of spleen and atrium. The terminal nerves supplying the muscular coats of the vas deferens were, like those in spleen and heart, devoid of DDC immunoreactivity. The presence of this enzyme is therefore not characteristic of either short or long noradrenergic axons, in support of previous evidence that it is a specific marker for dopaminergic terminal nerves. Many axons supplying the mucosal epithelial cells in the vas deferens were DDC-positive, suggesting the existence of a dopaminergic innervation.

Animals↗
PubMed1987

Effector T cell differentiation in experimental interstitial nephritis. I. The development and modulation of effector lymphocyte maturation by I-J+ regulatory T cells.

Because mice susceptible to interstitial nephritis use different effector T cells than nonsusceptible mice, we analyzed the differentiation process of the effector T cell repertoire by using an in vitro culture technique. In the presence of helper T lymphocytes, accessory cells, IL 2, tubular antigen, and precursor effector cells, both Lyt-2+ nephritogenic effector cells and L3T4+ nonnephritogenic effector cells can be initially induced in both susceptible and nonsusceptible strains within 3 days of culture. In nonsusceptible mice, however, the Lyt-2+ nephritogenic cell is inhibited from further development and disappears, whereas in susceptible mice, its presence is preserved with a resulting effect of tissue destruction. This selection of effector T cell preference is regulated by I-J+ T lymphocytes which are co-functionally expressed with effector cell expansion. Unlike precursor effector lymphocytes, however, the maturation of the regulatory process requires a subset of I-J+ accessory cells and structurally intact tubular antigen. Our findings indicate, therefore, that both susceptible and nonsusceptible mice have the potential for the expression of interstitial nephritis, but nonsusceptible mice are formally protected from autoimmunity by the regulation of lymphocyte preference.

Animals↗
PubMed1987

Primary lymphoma of the uterine cervix.

Primary lymphoma of the cervix is very rare. A case report is presented and 24 cases published in the English literature are reviewed. Evaluation, staging, treatment, and prognosis of this rare tumor are discussed.

Adult↗
PubMed1986

Murine interstitial nephritis. V. The auto-induction of antigen-specific Lyt-2+ suppressor T cells diminishes the expression of interstitial nephritis in mice with antitubular basement membrane disease.

We observed the emergence of an antigen-specific Lyt-2+ suppressor T cell after the i.v. injection of tubular antigen-derivatized lymphocytes into mice already immunized to produce interstitial nephritis. The auto-induction of these suppressor T cells effectively attenuated both the expression of renal injury and a delayed-type hypersensitivity response to tubular antigen. This suppressive effect was also genetically restricted by gene products in I-J and Igh-1. Although this suppressor system had a marked inhibitory effect on the nephritogenic effector cell repertoire, there was no diminution of titers of antibodies to the tubular basement membrane. Our results demonstrate a protective role for antigen-specific suppressor cells in autoimmune renal injury, and the strategy for their induction may have important therapeutic implications for other immune-mediated disorders.

Animals↗
PubMed1986

Frontonasal "dysplasia," cerebral anomalies, and polydactyly: report of a new syndrome and discussion from a developmental field perspective.

We describe a boy with frontonasal "dysplasia"; cerebral anomalies, including agenesis of corpus callosum and probable Dandy-Walker malformation (absent superior vermis, hypoplastic cerebellum and brain stem, and possible posterior fossa cyst in this case); short neck, relatively long trunk with short limbs; cryptorchidism; and polydactyly of hands and feet. We suspect he has a previously undescribed syndrome of presently unknown cause. We also discuss this case from a developmental field perspective, in view of the unusual combination of cerebral and facial defects.

Abnormalities, Multiple↗
PubMed1986

Phenogenetics of triploid intersexes in Drosophila melanogaster.

Triploid intersexes homozygous for a mutant (msl-2) known to impede the hyperactivation of the X chromosome in diploid males differentiate into adults, sexually indistinguishable from their heterozygous sibs. A shift toward female sexual differentiation mediated by manipulating the rearing temperature is accompanied by an apparent increase in the level of an X-linked gene product. This unexpected result is rationalized in terms of differential lethality of individuals at the two extremities of the distribution of X-activity levels in intersexes raised at a particular temperature. No evidence of a mosaicism comparable to the sexual mosaicism exhibited could be found with respect to an X-linked gene product in triploid intersexes.

Animals↗
PubMed1986

Experimental strategies for the study of cellular immunity in renal disease.

This overview has examined some of the current experimental options available for the study of cellular immunity in the immunopathogenesis of renal disease. T cell immunity, where it has been examined, seems to have a particularly pivotal role in orchestrating and regulating functional patterns of renal injury. The use of the research methods presented here for the study of cell-mediated interactional events in kidney disease, however, has lagged behind similar efforts in other organ systems. We hope, therefore, this report will serve to stimulate and strengthen further interest in the cell biology of the nephritogenic immune response.

Animals↗