Search PubMed⌕ Search

Biomedical subjects

J S Beck

Publications and source records attributed to J S Beck.

At least 163 records · Page 9Linked to original sources
PubMed1981

Serum inhibitory factor in lepromatous leprosy: its effect on the pre-S-phase cell-cycle kinetics of mitogen-stimulated normal human lymphocytes.

The sera of ten Egyptian man with long-standing lepromatous leprosy (LL) (mean duration 17.4 years) that had failed to respond to dapsone treatment were shown to inhibit mitogen stimulation responses of normal human lymphocytes. When first tested, the sera partly inhibited the response to phytohaemagglutinin (PHA) and pokeweed mitogen and virtually abolished that to concanavalin A (Con A): after repeated freezing and thawing, the Con A inhibition had disappeared, whereas the PHA response was still partly inhibited. The inhibitory serum factor(s) had similar actions on lymphocytes from each of six normal donors. Although the sera varied in potency, they showed similar dose-response curves when tested against lymphocytes from a single donor. The principal action of the sera was to reduce the number of cells responding to mitogen, without modifying the kinetics of recruitment or rate of volume growth during G1-phase in those cells that were unaffected by the inhibitory substances(s). Study of PHA dose-response curves and of the effect of delayed addition of LL serum suggested that the serum factor(s) act by diminishing the responsiveness of the cells, rather than by reducing the concentrations of free mitogen or by blocking cell membrane mitogen receptors. The serum from one apparently healthy attendant, who had nursed leprosy patients for 30 years but who did not have leprosy or other chronic infective disease, inhibited completely stimulation by all three mitogens in a manner different from that of LL sera. Serum from the other 13 control patients did not modify the response of normal lymphocytes to stimulation by any of the three mitogens studied. It was concluded that the inhibitory factor(s) in the serum of patients with LL were a consequence of the disease and not of the environment in which the patients lived. Microscopy confirmed that the techniques used for recovery of the cultured cells did not introduce bias into the volume spectroscopy measurements.

Adult↗
PubMed1981

Prognostic value of measurement of elastosis in breast carcinoma.

The extent of elastosis in the stroma within the anatomical "tumour" in 80 patients with breast carcinoma was assessed by observational microscopy using a 4-point grading system, and measured by semiautomated histometry as an area percentage with a Quantimet 720 image-analysing computer. In this retrospective study, measurement of elastosis in tissue removed at time of initial diagnosis was shown to have little value for prediction of duration of survival.

Adult↗
PubMed1981

A study of the histological basis of textural analysis.

In an attempt to quantitate histological structure by textural analysis, the characters of a stained microscopical field were recorded as a frequency polygon of the relative areas defined by successive increments of optical density: this is known as the optical density/area (OD/A) profile. In a study of lymph-nodes in Hodgkin's disease and of carcinoma of the female breast, each stained tissue section was found to have an OD/A profile of characteristic shape: moreover, in each of the lesions studied it was shown that the shape of the profile could be replicated by summing the profiles of each constituent cell type and intercellular matrix in proportions determined by differential cell counts and direct measurement of the degree of cell packing in the tissue. In an investigation of the influence of specimen preparation on OD/A profile, it was shown that density of staining and section thickness were important variables. Using the density of staining of tissue lymphocytes as an internal standard, a simple method was developed of compensating for differences in the density of Mayer's haemalum staining greater than those met with in practice. Attempts to compensate for intentionally large differences in section thickness were much less successful, but this was considered to be relatively unimportant since, in practice, the variation in thickness of sections cut on a modern microtome by a competent microtomist had been shown to be slight and to have a negligible effect on the OD/A profile.

Breast Neoplasms↗
PubMed1981

The effect of strenuous physical exercise on circulating blood lymphocytes and serum cortisol levels.

Venous blood was removed from healthy subjects immediately before and at intervals after exercise on a bicycle ergometer. Immediately after exercise, the subjects developed a lymphocytosis in which (a) the E-rosette percentage fell by 10% but their absolute number in the circulating blood rose by more than 70%, (b) the percentage of PHA-stimulated cells fell, but their absolute numbers increased considerably and (c) the absolute numbers of Con A- and PWM-responding cells increased. The numbers of lymphocytes in the various subpopulations had returned virtually to the pre-exercise levels 15 minutes after stopping exercise. During the response to exercise, the characteristics of the cells in the various subpopulations did not show any major changes, despite considerable and rapid fluctuations in numbers: it is suggested that exercise discharges intravascularly sequestered cells and that cortisol may be involved in re-sequestration of stress-released cells. It is recommended that, in clinical studies on circulating lymphocyte numbers and populations, the patient should be rested for at least 15 minutes before venesection.

Adolescent↗
PubMed1980

A simple method for determining the extent of cellular contamination in peripheral blood lymphocyte preparations.

A method is described for calculating, from the size distribution of the cells, the extent of cellular contamination of lymphocyte concentrates prepared from venous blood. The precision of this method was checked by direct comparison with differential leucocyte counts obtained by direct microscopy on 29 samples chosen because they showed a wide range of intensity of contamination. By virtue of its technical simplicity, the method has proved useful in a diagnostic service laboratory for checking the purity of lymphocyte preparations either before performing lymphocyte function tests or after a period of 24 h in tissue culture.

Cell Separation↗
PubMed1979

Short-term triiodothyronine in prevention of temporary hypothyroidism after subtotal thyroidectomy for Graves' disease.

To determine whether short-term thyroid hormone replacement prevents or merely delays temporary hypothyroidism after surgery for Graves' disease, serum T3, thyroid-stimulating hormone, and T4 were measured every 2 months for 18 months in two groups of Graves' disease patients who had had subtotal thyroidectomy. Group I (18 patients) were given T3 20 microgram four times daily from surgery through the twelfth postoperative month. Group II (18 patients) received no treatment. Hypothyroidism occurred at some time during the 18-month period in 10 group-II patients, but was temporary in 7. Temporary hypothyroidism did not occur in group-I patients, whose mean T4 level rose to that in group II within 2 months of T3 withdrawal. Short-term T3 replacement after surgery for Graves' disease thus prevents (and does not simply delay) temporary postoperative hypothyroidism without increasing the frequency of permanent hypothyroidism.

Adult↗
PubMed1979

A new method of testing for mitogen-induced lymphocyte stimulation: measurement of the percentage of growing cells and of some aspects of their cell kinetics with an electronic particle counter.

Human lymphocytes were cultured with or without added PHA for periods not exceeding one day so that none of the cells had entered the first mitotic division. The size distribution of the cells was measured with an electronic particle counter and the results were collected in a multichannel analyser. An iterative stochastic model was developed to estimate the proportion of responding cells and their growth characteristics. This mathematical model was based on a few simple assumptions about the pattern of cell growth and was considered to fulfill basic requirements of plausibility and parsimony. The technique described in this paper makes measurement of the absolute percentage of responding cells and their average growth rate in mitogen-induced lymphocyte stimulation tests possible in routine diagnostic laboratories for the first time.

Adult↗
PubMed1979

A new method for semi-automated quantitation of E-rosettes using a particle size analyser (Coulter Channelyzer).

Visual counts of the number of SRBC attached to individual lymphocytes in E-rosette preparations from 3 healthy young adults were made by 3 experienced observers: from these data the size distribution profile of particles in each E-rosette preparation was calculated. In parallel experiments the size distribution profile was measured directly with a particle size analyser (Coulter Counter and Channelyzer): in every case the observed profile lay within the 95% confidence band around the reconstructed profiles. It was concluded that the Coulter Channelyzer profile is an accurate measurement of the E-rosette size distribution and that particle sizing could provide a reasonable basis for semi-automated tests for E-rosettes. A mathematical model has been developed by which the percentage of lymphocytes forming E-rosettes, the distribution of number of attached SRBC and the average avidity of the lymphocyte receptor for SRBC could be deduced from the size-distribution profiles. The method has a high degree of precision, and a good correlation (P less than 0.01) was obtained when the percentage of E-rosettes (defined for this purpose as having three or more attached SRBC) obtained from the new method was compared with results from standard light microscopy.

Animals↗
PubMed1979

Erythrocyte volume and count: a linear relation descriptive of population differences.

In a sample of 215 adult males the mean red cell volume decreases linearly with increasing red cell concentration. The mean corpuscular volume and the red cell count are found uncorrelated with age of subject. Of these subjects 69 are identified as smokers and 114 as nonsmokers. Linear regression analysis shows negative linear relation for the smoking-defined groups, with slopes judged to be no different. When the regression lines are constrained to be parallel the line for smokers is displaced upward by 2.7 fl. No difference is found in mean corpuscular haemoglobin concentration or reticulocyte count. Haematocrit, haemoglobin, mean corpuscular haemoglobin are also reported. Viscosity of blood is greater in smokers. Optical determination of cell volume and area confirms the linear relation of volume and count.

Adolescent↗