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Biomedical subjects

R Bell

Publications and source records attributed to R Bell.

At least 271 records · Page 15Linked to original sources
PubMed1985

The kinetics of the production of granulocyte-monocyte colony stimulating activity (GM-CSA) by isolated human monocytes: response to bacterial endotoxin.

When mononuclear phagocytes are stimulated by bacterial endotoxins, they produce Granulocyte-Monocyte Colony-Stimulating Activity (GM-CSA). In order to study the kinetics of the production of GM-CSA by human monocytes, we prepared suspensions of these cells and studied their response to Salmonella typhi endotoxin. We found that when human monocytes were exposed to this preparation of endotoxin, they synthesized GM-CSA de novo and subsequently secreted it into the extracellular environment; however, within hours, the cells became highly refractory to further stimulation by endotoxin. The resistance to endotoxin which these cells rapidly acquired in vitro could not be accounted for by cell attrition, the accumulation of toxic metabolites in the cultures, negative feedback inhibition by newly synthesized GM-CSA, depolarization of the plasma membrane of the cells, or by degradation of endotoxin. When we studied the binding of tritium-labeled endotoxin to viable monocytes, we found that after monocytes were initially exposed to endotoxin, their subsequent ability to bind lipopolysaccharide molecules onto the surface of the plasma membrane was reduced. When we subjected concentrated supernates from endotoxin-stimulated monocyte cultures to gel filtration and isoelectric focusing, we noted that GM-CSA derived from human monocytes had an apparent molecular weight of approximately 42,000 daltons. Our results indicate that resistance to bacterial endotoxins acquired by mononuclear phagocytes may play a role in the immunologic phenomenon of immediate endotoxin tolerance observed in vivo and may in part be due to down-regulation of endotoxin binding to the outer surface of the cell.

Cells, Cultured↗
PubMed1984

Glucocorticoid receptors in leukemia cells: an appraisal.

There is growing interest in the molecular events which govern response to therapy in the leukemias. Glucocorticoid therapy would appear to be a fertile area for study as much is known about mechanism of steroid hormone action. In this paper we review current knowledge of glucocorticoid receptor numbers and function in leukemic blast cells and their relationship to steroid treatment and outcome.

Animals↗
PubMed1984

Comparative study of the effects of intravenous administration of aminophylline, salbutamol and terbutaline in patients suffering from reversible airways obstruction.

A study was carried out in 20 patients with reversible airways obstruction to compare the bronchodilator potency of salbutamol (250 micrograms), terbutaline (500 micrograms) and aminophylline (250 mg), given by slow intravenous injection. Patients received each of the three treatments, on separate days, in random order using a double-blind design. Measurements were made of pulmonary function, pulse rate and blood pressure and side-effects were recorded before and at intervals up to 4 hours after drug administration. All three drugs improved pulmonary function to a significant degree and this effect was observed at 5 minutes post-treatment and lasted for 3 hours. Terbutaline and salbutamol had a significantly greater effect than aminophylline, but there was no difference between salbutamol and terbutaline. Both salbutamol and terbutaline produced tachycardia of a similar magnitude, and which returned to initial values within 90 minutes post-injection. Aminophylline did not cause tachycardia and this difference compared with the beta-agonists on pulse rate was statistically significant (p less than 0.001). Salbutamol caused a significantly greater incidence of palpitations than did either aminophylline (p less than 0.01) or terbutaline (p less than 0.05). No other differences between treatments were observed.

Adult↗
PubMed1984

Sex differences in the use of alcohol and tranquilizers: testing a role convergence hypothesis.

Research on adult alcohol and tranquilizer use provides strong evidence of fundamental sex differences in the use of the two types of drugs. Current explanations posited for these differences center around differential sex roles and sex role expectations. Much of the discussion of these differences suggests that as male and female roles converge, these behavioral differences should decrease. Using data from a statewide survey of Illinois adults, we provide a preliminary test of a sex role convergence hypothesis for alcohol and tranquilizer use. To do so, we use a multinomial extension of logistic multiple regression. After controlling for demographic and sex role characteristics, the results show that females have a much higher probability of using tranquilizers rather than alcohol than men do. Thus, the role convergence hypothesis is not supported for the use of these two types of drugs.

Adolescent↗
PubMed1984

Characterization of glucocorticoid receptors in animal lymphoblastic disease: correlation with response to single-agent glucocorticoid treatment.

The clinical significance of initial DEAE chromatography of glucocorticoid binders in lymphoblastic disease was evaluated in an animal model. Domestic cats and dogs with lymphoblastic disease were treated with prednisone, 2 mg/kg/day, for 14 days, and the outcome of therapy was correlated with DEAE chromatograms of glucocorticoid binders, using 3H-triamcinolone as ligand. Six of 30 animals had a single-peak low-salt binder species, similar to that seen in a subset of human leukemia, and none of these responded. Of the 29 animals with chromatograms identical to normal tissues, 6 had a complete response and another 11 a partial response. This distribution of responders is statistically significant (p = 0.02). Thus, the leukemia-associated single-peak DEAE species appears to be associated with glucocorticoid resistance, as defined by clinical responsiveness. In contrast, the two-peak normal pattern is a necessary, but insufficient, criterion for defining responsive disease.

Animals↗
PubMed1983

ALL masquerading as AUL.

Of 597 cases of acute leukaemia in adults (greater than 16 years) seen at St. Bartholomew's Hospital, London, between May 1973 and January 1982, 412 were diagnosed as AML, 103 as ALL and 58 as Philadelphia chromosome positive blast crisis of CML (13 presenting as acute leukaemia and 45 having a prior chronic phase). The remaining 24 cases were considered to be acute undifferentiated leukaemia. Twenty-one of the latter were investigated using a panel of immunological markers at diagnosis and/or retrospectively using frozen cell suspensions. Eighteen out of 21 were shown to have a predominantly 'lymphoid' phenotype which comprised 12 cases of common ALL (two of whom were Ph1 positive), three cases of null-ALL, one case with a probable early thymic phenotype, and two cases with a monoclonal B lymphoblast phenotype. One 'common ALL' and one 'null-ALL' had a significant proportion of pre-B (cytoplasmic mu chain+) cells. One other case reacted with anti-myeloid sera. Leukaemic blasts from two patients were unreactive with all markers tested. No cases of glycophorin positive erythroleukaemia or anti-platelet (glycoprotein I) positive leukaemia were detected. These observations suggest that the overwhelming majority of acute leukaemias have an identifiable affiliation to the lymphoid or myeloid lineages and that patients diagnosed haematologically as 'AUL' might benefit by therapy appropriate for their leukaemic cell type.

Acute Disease↗
PubMed1983

Vincristine-induced bladder neuropathy.

We report a case of detrusor areflexia caused by vincristine neurotoxicity and documented by urodynamic testing. Vincristine commonly induces peripheral neuropathy but rarely causes voiding dysfunction. Neurourological evaluation aided in monitoring and understanding this problem.

Drug Therapy, Combination↗
PubMed1983

Assessing the outcomes of nursing-home patients.

This paper describes the development of multidimensional measures of nursing-home patients' functioning. The technique was designed to gather information directly from the patients, using demonstrated ability in place of self-report wherever possible. Six domains are tapped: physiologic, activities of daily living, affective, cognitive, social, and satisfaction. Test-retest reliability ranges from .59 for social interaction to .85 for affect. Validity was tested by replication on successive waves of data as well as discriminant and content validity.

Activities of Daily Living↗
PubMed1983

The prediction of preterm labour by recording spontaneous antenatal uterine activity.

The recording of spontaneous antenatal uterine activity was assessed as a predictor of preterm labour in a group of patients considered at high risk on the basis of a past history of preterm delivery. The recording of individual uterine contractions greater than or equal to 15 mmHg between 20 and 28 weeks gestation was found to be useful for the prediction of preterm labour in this high risk group.

Female↗
PubMed1983

Effect of protein deficiency on endogenous pyrogen-mediated acute phase protein responses.

Endogenous pyrogen (EP) is known to trigger a rise in the plasma concentrations of various acute phase reactant proteins. This study describes the effects of chronic protein deficiency in rabbits on EP-mediated changes in the plasma concentrations of fibrinogen, albumin, and alpha 2-macroglobulin. Injection (i.v.) of EP from healthy donors into protein-deprived rabbits produced a smaller rise in plasma fibrinogen and alpha 2-macroglobulin, and a smaller fall in plasma albumin than injection of EP into controls. Injection of EP, obtained from malnourished donors, into healthy rabbits also resulted in an attenuation of the acute phase protein response. These data are consistent with the hypothesis that EP activity is influenced by the nutritional status of both the donor and recipient of EP.

Animals↗
PubMed1983

Uses of the 1980 census for Hispanic health services research.

The 1980 Census data provide a valuable resource for health services research on Hispanics. Hispanics are the fastest growing minority group in the United States and yet there is a paucity of large-scale empirical research on their health care and access needs. This paper describes how the census can assist in: 1) estimating the overall health care needs of this group, 2) identifying target groups within the Hispanic population who may have special health care problems (e.g., children, elderly, pregnant women, etc.); and 3) using other data sources to improve the quality of studies carried out on Hispanics. It also discusses problems in using the census for Hispanic health services research and some strategies for dealing with these problems.

Educational Status↗