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Biomedical subjects

G Morris

Publications and source records attributed to G Morris.

At least 109 records · Page 6Linked to original sources
PubMed1982

Chemical composition of sheep bones as influenced by molybdenum supplementation.

Two corn silage diets containing .4 and 10 to 12 ppm molybdenum (dry matter) were fed ad libitum to two groups of six crossbred wethers each. Wethers were kept on these diets for 7 mo, and at slaughter various bones of front legs were dissected. Wethers fed added molybdenum had more molybdenum and zinc in bones than controls. Greater concentration was in the later ossifying portion of the bone than in the more mature areas. Copper, magnesium, phosphorus, calcium, and total ash of sheep bones were unaffected by dietary molybdenum. The compact shaft contained more ash, calcium, phosphorus, and magnesium than the proximal and distal part of the bone. No differences were significant in nitrogen, carbon dioxide, and uronic acid contents of the various bones between the two diets. Site of bone sampling, however, influenced organic composition of bones. Nitrogen concentration was greater at proximal and distal ends of bone than in the shaft. Carbon dioxide varied similarly but in a reciprocal fashion.

Animals↗
PubMed1981

Factor VIII-related activities in therapeutic concentrates.

Recent studies have suggested that factor VIII exists in plasma as a complex containing two distinct antigens (VIII R:Ag and VIII C:Ag) and two different biological activities (VIII:C and VIII R:RCo). Concentrations of these four entities have been measured in all the different types of therapeutic material used for treatment of hemophilia and von Willebrand's disease. In all materials, the ratio of VIII R:Ag to VIII:C was greater than 1: however, there were significant differences between concentrates, and the lowest ratio was found in cryoprecipitate. In VIII R:Ag assays, the freeze-dried concentrates gave nonparallel dose-response curves compared with plasma, indicating alterations in molecular form during purification. Values for VIII C:Ag were much lower than the corresponding VIII R:Ag values, and ratios of VIII C:Ag to VIII:C were close to 1 in many of the concentrates, suggesting that the low yields of VIII:C in some production processes could result from losses of VIII:C molecules rather than from denaturation. Measurement of VIII R:RCo by a platelet counting method gave lower values in most concentrates than by an aggregometry technique. It is proposed that the platelet counting method may reflect closely the biological activity of the concentrates in treatment of von Willebrand's disease.

Antigens↗
PubMed1981

The cells of the tracheobronchial epithelium of the mouse: a quantitative light and electron microscope study.

The epithelium of the conducting airways of the mouse consists of a single layer of cells. The number, type and form of these cells have been investigated at five airway levels from the trachea to the distal conducting bronchi with both light and electron microscopes. Contrary to what is found in other species, the majority (50-60%) of cells in the murine airway epithelium are Clara cells. Mucus-producing tissue was infrequent throughout the airways, though epithelial mucous cells occurred in increased numbers at the carina and in the primary bronchus. No mucous or serous cells or submucosal glands were seen in intralobular airways. On a morphological basis, three distinct forms of Clara cell were recognized. On occasion, cells were observed which were apparently transitional types between these and also between Clara cells and mucous or ciliated cells. It is suggested that the 'transforming' cells may indicate a role for the Clara cell as a developmental cell involved in the epithelial cell turnover. Evidence is also provided that Clara cells may undergo both apocrine and merocrine secretion and, it is argued that the latter may be of a PAS + ve material. Free nerve endings were not seen in the epithelium. This may be related to athe restricted ability of mice to cough. It is suggested that the lack of mucus-producing tissue and of cough reflex may be due to the small diameter of the mouse airways.

Animals↗
PubMed1980

The distribution and structure of cells in the tracheal epithelium of the mouse.

The tracheal epithelium of the mouse is a single layer of columnar cells resting on a basement membrane. Many of the cell types resemble those of other species. However, goblet cells are rare and ciliated cells occur only in scattered patches. Submucosal glands are absent from all but the highest reaches of the airway. The major proportion of the epithelial cells are non-ciliated. These usually project into the lumen of the trachea. Large amounts of smooth endoplasmic reticulum and many secretory vesicles occur within the cytoplasm. Secretory activity of these cells may be either apocrine or merocrine and these cells may transform into other cell types. It is suggested that these non-ciliated cells are Clara cells and that the mouse tracheal epithelium may make a useful model for the study of this type of cell.

Animals↗
PubMed1979

Binding of bovine immunoglobulins to pituitary intermediate lobe cells.

Basophilic granular cells of the bovine pituitary intermediate lobe and intraglandular colloid show an affinity for immunoglobulin IgG, IgA, and IgM. The cells were identified by direct and indirect fluorescent staining methods using blocking tests as controls. It is suggested that these cells may play some role in the synthesis and release of immunoglobulins or their determinants to the intact Ig molecule.

Animals↗
PubMed1977

Conformational studies on histone H3 and its CNBr peptides.

Histone H3 and H3 peptides 1--120, 1-90, 91-135, 91-120 and 121-135 have been prepared and examined for salt-induced conformational changes by circular dichroism measurements. It was found that reduced histone H3 and the reduced peptides 1-120, 91-135 and 91-120 exhibit biphasic changes with the formation of alpha-helix and beta structures. H3 peptide 1-90, on increasing the ionic strength to moderately high levels, monophasically formed appreciable quantities of alpha-helix and beta structures, while peptide 121-135 remained unfolded under all ionic strengths examined. All the above peptides except 121-135 also aggregate when the ionic strength is raised. The salt-induced near-ultraviolet circular dichroic spectra of histone H3 and peptide 1-90 were found to be very similar, suggesting that the conformational changes induced in the peptide 1-90 are essentially the same as those observed for the intact histone. These results support the contention that the polypeptide segments of this histone interact initially by parallel self-association followed by the formation of even larger aggregates on a longer scale.

Amino Acid Sequence↗
PubMed1975

A mechanical dissociation method for preparation of muscle cell cultures.

A cell preparation method by which large numbers of embryonic chick skeletal muscle cells may be obtained is described. The procedure requires fewer manipulations and much less time than standard trypsinization. By the criteria used, both methods are comparable with respect to percent viable cells and survival of plated cells. However, in addition to the ease of preparation, the mechanical dissociation method offers the significant advantage that the cell suspension is greatly enriched for myoblasts without the necessity of an additional preplating step.

Cell Separation↗
PubMed1974

Treatment of urinary retention.

In 50 patients retention of urine due to adenomatous enlargement of the prostate was relieved, in most cases by intraprostatic injections given for varying periods of time. No complications were encountered. Subsequently, some of the patients who did not respond adequately, and whose medical conditions improved, underwent prostateceomy. Histologically the removed prostates showed coagulation necrosis, with or without haemorrhage, but no inflammatory reaction.

Acetates↗
PubMed1969

Continuous punishment of free-operant avoidance in the rat.

Three groups of albino rats were trained under a free-operant avoidance (Sidman) procedure with equal shock-shock and response-shock intervals. After stable performance was achieved, the animals were concurrently exposed to a brief electric shock after each response. The procedures were as follows: Punishment Schedule I: punishment shock was introduced at an intensity approximately one quarter that of avoidance shock; increments of nearly this same size were made as stable performance was achieved at succeeding punishment shock intensities. Punishment Schedule II: punishment shock was introduced at approximately one-half the intensity of avoidance shock; after stable performance, punishment shock was increased to the same intensity as avoidance shock. Punishment Schedule III: punishment shock was introduced and maintained at the same intensity as avoidance shock. Punishment was continued for all groups until one of two suppression criteria was attained. All animals made fewer responses and received more avoidance shocks as a function of increasing punishment shock. Half of the animals under Punishment Schedule I required punishment shock higher than avoidance shock to meet their assigned suppression criterion. A comparison of all procedures showed that suppression was greater when punishment shock was initially at high intensity.

Journal Article↗