PubMed Health⌕ Search

Biomedical subjects

M Simpson

Publications and source records attributed to M Simpson.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1980

Effects of chromosome constitution on growth and longevity of human skin fibroblast cultures.

Employing standardized cell-culture methods, 10 euploid and 22 constitutionally aneuploid human skin fibroblast strains were assessed in triplicate for total growth potential, growth rates, population-doubling times, and cloning. In addition, longitudinal growth rate studies were carried out with otherwise isogenic 45,X and 47,XXX clonal cultures derived from a mosaic parental strain. Growth rates and longevities were cell-strain specific and highly reproducible among sister cultures of a given strain. There was no systematic correlation between chromosome constitution and any of the measured growth parameters. Trisomic as well as monosomic strains showed the same degree of variability with respect to these parameters as did euploid cultures. In particular, 4 trisomy 21 strains were not unusually short-lived, nor were clones with the 47,XXX constitution compared to those with 45,X karyotypes. We therefore conclude that the cumulative number of in vitro doublings preceding senescence of fibroblast-like cells cultured from skin does not differ significantly among cultures derived from humans who have a normal karyotype, trisomy 13, 18, or 21, the 45,X constitution, or various combinations of extra X and Y chromosomes.

Aneuploidy↗
PubMed1980

Oral and rectal absorption of chloral hydrate and its betaine complex.

Chloral hydrate and its betaine complex was administered orally and rectally to nine healthy male subjects. The urinary excretion, which was a reflection of absorption, of a metabolite, trichloroacetic acid, was determined. No statistically significant difference was found between the oral absorption of chloral hydrate and its betaine complex and between the rectal absorption of chloral hydrate and its betaine complex. A statistical difference was found between the oral and rectal absorption of chloral hydrate and between the oral and rectal absorption of chloral betaine.

Administration, Oral↗
PubMed1980

The relation between bone loss and calcium balance in women.

1. We have examined the relation between the rate of cortical bone loss and other measured variables in 108 women, untreated and on various therapies, observed for nearly 300 patient years. The majority of the subjects were postmenopausal women with various degrees of simple osteoporosis, but a few cases of hyperparathyroidism and other calcium disorders were included. 2. Calcium balance, bone resorption rats, urinary hydroxyproline and plasma alkaline phosphatase were shown to be related to the rate of bone loss; patients with the more negative balance or the higher values of the other variables had significantly higher rates of loss. The rate of bone loss was independent of the rate of bone formation.

Aged↗
PubMed1980

Studies on the mechanism of action of rabbit anti-mouse thymocyte serum. I. Induction of suppressor cells.

Treatment of B6AF1 (C57BL/6 x A/Jax) mice with either rabbit anti-mouse thymocyte serum (ATS) or with both ATS and sheep red blood cells (SRBCs) resulted in the generation of splenic suppressor cells within 5 days. Suppressor activity was determined by injecting secondary syngeneic recipients with both donor cells and SRBCs. Five days later the SRBCs hemolytic effect of their spleen cells was determined. Suppressor cells were found in either whole spleen or enriched T cell suspensions from mice treated with ATS and SRBCs and in only enriched T cell suspensions from mice treated with ATS alone. These results support the possibility that ATS induces a population of suppressor cells and that these cells may be responsible in part for the immune suppression noted after treatment with ATS.

Animals↗
PubMed1980

Using discriminant function analysis with clinical, demographic and historical variables to diagnose schizophrenia.

An effort was made to formalize the critical clinical, demographic and historical features of schizophrenia through the development of a reliable assessment questionnaire. The criterion diagnosis was established via traditional hospital procedures and was substantiated by psychometric measures. Raters with comparable diagnostic experience were familiarized with each of the clinical, demographic and historical features before evaluating the presence or absence in a sample of both psychiatric in-patients and out-patients. A structured, standardized interview was used to reduce inconsistency and oversight due to variability in interviewing techniques and coverage of psychopathology. Using the coefficients of the discriminative functions of five major symptoms (loose associations, autism, loss of ego boundaries, emotional blunting, delusions) and two demographic and historical features (family history of mental illness, poor social relations) correctly classified 98 per cent of the total sample of 253 patients. A subsequent investigation demonstrated the utility and generalizability of the proposed system. The assets and liabilities of using such an approach are discussed.

Adolescent↗
PubMed1979

Predictive validity of the Rorschach Prognostic Rating Scale with schizophrenic patients.

The prognostic validity of the Rorschach Rating Scale was assessed with schizophrenic patients. Through the use of a standardized structured interview and a diagnostic system for schizophrenia based on the use of discriminant function analysis with nonpathognomonic symptom combinations, a reliable and valid system was used to establish the criterion diagnosis. Outcome criteria used included a variety of measures of schizophrenic thought disorder. The results help to establish the practical utility of the PRS empirically with schizophrenic patients by demonstrating efficient prediction when other relevant demographic and nontest variables have been controlled. Furthermore, the concept of ego strength from which the PRS was developed does not appear to be too global a characteristic when the area for change is specifically delineated.

Adolescent↗
PubMed1979

Calcium requirement and calcium therapy.

The mean calcium requirement of normal adults has been estimated from 212 calcium balances on 84 normal subjects and found to be 578 mg. The calcium allowance required to ensure that 95% of normal adults are in calcium balance is about 900 mg. Calcium requirement is relatively higher than that of phosphorus or magnesium because plasma calcium--and therefore urine calcium--is maintained at the expense of the skeleton in the presence of calcium deficiency, whereas plasma phosphate and magnesium--and therefore urine phosphate and magnesium--fall on phosphorus and magnesium deficient diets. Calcium requirement appears to rise at the menopause, and postmenopausal bone loss can be reduced by calcium supplements. In postmenopausal osteoporosis, the severe negative calcium balance can be corrected by giving calcium or calcium and vitamin D, but vitamin D alone is not beneficial. Similarly, bone loss, height loss and further vertebral compression can be reduced by calcium or calcium and vitamin D but not by vitamin D alone.

Bone Diseases↗
PubMed1978

Mass and infrared spectra of diaryl and aryl alkyl sulfate diesters.

The synthesis and the infrared and mass spectra of diaryl and aryl alkyl sulfate diesters are described. The mass spectra of these two classes of compounds consistently showed an intense molecular ion and two or three additional intense, diagnostic ions. Their infrared spectra also gave information useful for characterizing and differentiating these two classes of compounds.

Benzene Derivatives↗
PubMed1978

The conversion of aryl sulfate ester salts to alkyl aryl derivatives suitable for analysis by electron impact mass spectrometry.

A series of monosubstituted (CH3, CH3O, Cl Br or NO2 at the O, m and p position) phenyl sulfate ester salts were derivatized to form n-propyl aryl sulfate diesters. The derivatization was accomplished by reacting aryl sulfate ester salts, AgClO4 and n-propyl iodide in SO2 at--40 degree C. The mass spectra of all the n-propyl aryl sulfate esters showed an intense molecular ion and intense diagnostic peaks at M--42 ([aryl--OSO3H]+) and M--122 ([ARYL--OH]+). The utility of this procedure for derivatizing selected sulfate ester conjugated xenobiotics and steroids was demonstrated.

Arylsulfonates↗