Search PubMed⌕ Search

Biomedical subjects

M Simpson

Publications and source records attributed to M Simpson.

At least 73 records · Page 4Linked to original sources
PubMed1987

Acute Ehrlichia platys infection in the dog.

Ten dogs were inoculated with Ehrlichia platys (E. platys) from an acutely infected dog. Two dogs were necropsied on each of days 7, 14, 21, 28, and 35 post-inoculation, and tissues were collected and either fixed in formalin or frozen for light microscopic examination of lesions or E. platys antigen localization in tissues. Serum antibody titers to E. platys and serum aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase activities were also determined. The significant light microscopic findings were lymph node follicular hyperplasia and crescent-shaped hemorrhages in the splenic periarteriolar lymphoid sheaths beginning day 7 post-inoculation. There was significant megakaryocyte hyperplasia of bone marrow on days 28 and 35 post-inoculation. Ehrlichia platys antigen was in macrophages at 14 days post-inoculation which corresponded to the initial decline in platelet numbers. Initial thrombocytopenia and splenic crescent-shaped hemorrhages were temporally related, however the degree of lesion development and prominence were not related to subsequent platelet numbers.

Acute Disease↗
PubMed1986

Activities of some key enzymes of carbohydrate, ketone body, adenosine and glutamine metabolism in liver, and brown and white adipose tissues of the rat.

In general, the activities of enzymes in brown adipose tissue (BAT) are more similar to those in white adipose tissue than those in liver. Thus the activities of the glycolytic enzymes hexokinase and 6-phosphofructokinase are high but those of glucose 6-phosphatase and fructose bisphosphatase are non-detectable in the two adipose tissues. The activity of HMG-CoA synthase was non-detectable in BAT indicating that this tissue, unlike liver, cannot produce ketone bodies from fatty acid oxidation but, since the tissue possesses a high activity of HMG-CoA lyase, it might produce ketone bodies from leucine catabolism. The findings suggest that 'metabolically' brown adipose tissue can be classified better as an adipose tissue than as a peripheral liver. A high activity of 3-oxoacid CoA transferase but a non-detectable activity of 3-hydroxybutyrate dehydrogenase suggests that BAT can utilise acetoacetate but not 3-hydroxybutyrate for heat generation during cold exposure plus starvation.

Adenosine↗
PubMed1986

Surfboard-related ocular injuries.

Three cases of ocular trauma caused by surfboards are reported. The severe nature of the injuries is discussed and the prevalence of this type of injury is reviewed.

Adult↗
PubMed1985

Gliding movement of and bidirectional transport along single native microtubules from squid axoplasm: evidence for an active role of microtubules in cytoplasmic transport.

Native microtubules prepared from extruded and dissociated axoplasm have been observed to transport organelles and vesicles unidirectionally in fresh preparations and more slowly and bidirectionally in older preparations. Both endogenous and exogenous (fluorescent polystyrene) particles in rapid Brownian motion alight on and adhere to microtubules and are transported along them. Particles can switch from one intersecting microtubule to another and move in either direction. Microtubular segments 1 to 30 microns long, produced by gentle homogenization, glide over glass surfaces for hundreds of micrometers in straight lines unless acted upon by obstacles. While gliding they transport particles either in the same (forward) direction and/or in the backward direction. Particle movement and gliding of microtubule segments require ATP and are insensitive to taxol (30 microM). It appears, therefore, that the mechanisms producing the motive force are very closely associated with the native microtubule itself or with its associated proteins. Although these movements appear irreconcilable with several current theories of fast axoplasmic transport, in this article we propose two models that might explain the observed phenomena and, by extension, the process of fast axoplasmic transport itself. The findings presented and the possible mechanisms proposed for fast axoplasmic transport have potential applications across the spectrum of microtubule-based motility processes.

Animals↗
PubMed1985

Binding of antihuman globulin by exfoliated renal tubular cells following kidney transplantation.

Exfoliated renal tubular epithelial cells (RTCs) from kidney allograft recipients may bind antibody against human globular proteins. Urine from sixty consecutive transplant recipients was studied in the first month following transplantation to relate this binding to the clinical course and rejection. The spun, washed sediment was incubated with fluoresceinated goat antihuman globulin and examined under light and fluorescent microscopy for fluoresceinated RTCs. Of 28 patients who were never positive, 27 manifested no clinical rejection episodes. Of 22 total rejection episodes, 21 were preceded by the appearance of fluorescent RTCs. Five patients in this group did not revert to negative in this test, and all went on to loss of graft from acute rejection. Of 46 patients who were discharged from the hospital with negative RTCs, only four were readmitted within one month for treatment of rejection. In contrast, of the 11 patients who were positive at the time of discharge, 10 were readmitted in the first month. Graft survival was only 55% (6/11) in this latter group as compared with 91% (42/46) in the former. There were 11 patients with transiently positive tests who did not warrant a clinical diagnosis of rejection. In no case of acute tubular necrosis (ATN) alone or in obstructive uropathy was the assay positive. However, in some cases, in which the ATN merged imperceptibly into rejection, the RTCs started to fluoresce well in advance of the clinical suspicion of rejection. Information obtained from this examination may be used to assess the cause of renal failure in the early posttransplant period and to differentiate rejection from ATN and obstruction. This phenomenon of fluorescent RTCs may be an early manifestation of an immunological change occurring in a cell that is targeted by the host for rejection.

Antibodies, Anti-Idiotypic↗
PubMed1984

Gnathostomiasis. Infestation in an Asian immigrant.

With the recent influx of southeast Asians into the United States, an increased incidence of human gnathostomiasis can be expected. A Laotian woman had had two weeks of pruritus associated with fleeting erythematous patches on her abdomen. A peripheral eosinophilia was present. She withdrew a Gnathostoma spinigerum from the skin of her abdomen. Gnathostomiasis is endemic in much of Asia and causes not only migratory cutaneous swellings with erythema but also serious visceral sequelae such as eosinophilic encephalomyelitis. Excision of the parasite is the treatment of choice when possible.

Adult↗
PubMed1983

Dissolution kinetics of a three-component solid I: ethylparaben, phenacetin, and salicylamide.

The dissolution rates of each component in compressed spheres consisting of three components were measured under sink conditions. A film diffusion model is discussed and presented diagrammatically to illustrate the 13 possible dissolution behaviors of a three-component solid. Experimental dissolution rates compare favorably to dissolution rates calculated according to the model at mass fractions representative of the 13 dissolution behaviors.

Kinetics↗
PubMed1983

Sex bias in the assessment of patient complaints.

This study investigates the contention that physicians have prejudicial attitudes toward female patients. One hundred twenty of 220 (58 percent) primary care physicians returned questionnaires that recorded their attitudes toward two hypothetical patients, one with a headache, one with abdominal pain. By changing only the gender of nouns and pronouns, two otherwise identical versions of each case had been constructed, one case describing a female patient, one a male patient. The physician subjects recorded their attitudes on a semantic differential scale designed to measure three dimensions of attitudes toward patients: authenticity, impression of severity of illness, and emotionality. The physicians judged the female patients to be more emotional (P less than .05) but no less authentic or ill than the male patients.

Attitude of Health Personnel↗
PubMed1982

Development of suppressor T cells by antilymphocyte serum treatment in mice.

Administration of rabbit anti-mouse lymphocyte serum (ALS) in mice results in the development of suppressor cells which can be detected by coculture mixed lymphocyte culture experiments. The putative suppressor cells inhibit nonspecifically the proliferative response as well as generation of cytotoxicity of normal responder cells. Suppressor activity is dose dependent and is not attributable to cell crowding, shifting of peak activity, or release of cell-bound ALS. Additional antigenic stimulation by skin allografting in ALS-treated mice shifts the specificity of suppressor cells from nonspecific to specific for skin donor alloantigen. ALS-induced suppressor cells are Lyt-1+2- T cells while suppressor cells present in ALS-treated, skin allograft-bearing mice are Lyt-1-2+ T cells. Both types of suppressor cells appear to bear I-J determinants. The possible mechanisms of suppressor cell induction by ALS and skin allografting are discussed.

Animals↗
PubMed1981

A left/right comparison of sequential bone loss from the metacarpals of postmenopausal women.

The rate of decrease of mean metacarpal cortical width was assessed by sequential radiographic morphometry for each hand separately in a series of 46 right-handed postmenopausal women observed for 222 patient-years. For the left hand, the mean rate was 0.0331 +/- 0.0053 mm/year and for the right, 0.0310 +/- 0.0060 mm/year. The difference between the hands in the rate of decrease was not significant. It is concluded that the higher work load of the dominant hand has no effect on the rate of bone loss from the metacarpals of postmenopausal women.

Aged↗
PubMed1981

Flow-cytogenetics. II. High-resolution ploidy measurements in human fibroblast cultures.

high-resolution flow-cytometric measurements of ethidium bromide/mithramycin-stained human fibroblast cultures reveal discrepancies between fluorescence pulse-height distributions and genome size as a function of cell strain, culture conditions, culture age, and proliferative stage. These discrepancies were quantitatively assessed by (1) evaluation of the variation of the widths of the 2c fluorescence pulse-height histogram peaks, (2) comparisons between sample to standard fluorescence ratios of 45,XO and 49,XXXXY cell strains, and (3) comparison of fluorescence intensities among cell populations of identical genome size but differing degrees of chromatin condensation (mitotic vs. nonmitotic cells of diploid and tetraploid cell strains). As in our previous studies with lymphocytes, our results suggest caution in equating fluorescence intensity with "DNA content" in flow measurements of nonhomogeneous cell populations. Conditions of cell culture and sample preparation must be standardized in order to compare "DNA content" differences by flow techniques. Remaining sources of variation presently limit detection to differences in DNA content of greater than 2%.

Cell Line↗
PubMed1980

Treatment of spinal osteoporosis in postmenopausal women.

Ninety-five postmenopausal women with unequivocably wedged or compressed vertebrae in whom the recognised causes of secondary osteoporosis had been excluded were studied, 41 having no treatment and the rest one or more of six different treatments. The treatment regimens comprised calcium supplements, vitamin D, calcium and vitamin D, ethinyloestradiol or--where oestrogens were contraindicated--norethisterone, 1 alpha-hydroxycholecalciferol (1 alpha-OHD3), or hormones with 1 alpha-OHD3. The seven groups were reasonably comparable in most respects except that the hormone-treated patients were younger and had a higher initial cortical area ratio than the others, and the calcium- and hormone-treated groups had the best initial radio-calcium absorption. The untreated osteoporotic patients lost cortical bone more rapidly than do normal postmenopausal women. Three treatments (calcium, hormones, and 1 alpha OHD3 plus hormones) appear to be useful in modifying the disease, and two treatments (vitamin D and 1 alpha-OHD3) useless or even harmful. Vitamin D and 1 alpha-OHD3 are more safely used in conjunction with oestrogens, which protect bone against resorption, than on their own.

Aged↗