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Biomedical subjects

R Evans

Publications and source records attributed to R Evans.

At least 379 records · Page 21Linked to original sources
PubMed1984

Foreign bodies in the hand.

A prospective study was carried out on 164 consecutive cases presenting at the Accident Department with foreign bodies in the hand. The distal segment of the digits was the commonest site. The late, symptomatic presentation of patients, together with the development of symptoms in patients managed conservatively indicate that foreign bodies should be removed. General anaesthesia is rarely required, but an effective "block" with a tourniquet is necessary, as infiltration anaesthesia has a high failure rate, and secondary exploration a high complication rate. Glass fragments are almost always visible on plain x-rays.

Accidents, Occupational↗
PubMed1983

Predisposition of [125I]5-iodo-2'-deoxyuridine-labeled normal and neoplastic mouse fibroblasts to lysis by normal macrophages.

During an investigation into the apparent natural cytotoxicity of normal peritoneal macrophages toward the murine MCA/76-9, MCA/76-45, and MCA/76-64 sarcoma cells in vitro, it was found that the peritoneal macrophages from nine different inbred strains of mice, as well as spleen and tumor-associated macrophages, preferentially lysed [125I]5-iodo-2'-deoxyuridine [( 125I]dUrd)-labeled target cells. However, unlabeled target cells were actively proliferating under the same conditions. Proliferation of target cells occurred independently of the lytic event, as measured by counting residual tumor cells at intervals or by pulsing cultures with tritiated thymidine [( 3H]dThd), both of which parameters were relatively the same in the presence or absence of macrophages. Moreover, macrophage-enhanced lysis of [125I]dUrd-labeled cells was not confined to tumor cells since adherent labeled nontransformed C57BL/6J 3T3 cells, mouse embryo fibroblasts, and suspended concanavalin A-stimulated lymphoblasts were also induced to release 125I faster in the presence than in the absence of macrophages. Prelabeled L1210 lymphoma cells were not lysed by normal macrophages. Lipopolysaccharide (LPS) treatment of resident peritoneal macrophages did not induce a stronger lytic effect than that induced by untreated macrophages, but it did result in macrophage-mediated inhibition of DNA synthesis by tumor cells. LPS-treated thioglycollate-elicited macrophages induced a higher specific 125I release from tumor cells than the release from untreated macrophages. Tumor target cells prelabeled with the less radiotoxic [131I]dUrd were also more predisposed to the lytic action of normal macrophages, while [3H]dThd-labeled target cells were relatively unaffected by the presence of macrophages. Thus certain types of normal and neoplastic cells may become highly susceptible to macrophages or their products after the target cell DNA had incorporated radioactive IdUrd.

Animals↗
PubMed1983

Heterogeneity of human NK cells: comparison of effectors that lyse HSV-1-infected fibroblasts and K562 erythroleukemia targets.

In this study, we compared the natural killer (NK) cells that lyse HSV-1-infected NK(HSV-1) or uninfected [NK-(FS)] fibroblasts to those that lyse K562 erythroleukemia cells [NK(K562)]. Activity against all three targets was found in Percoll gradient fractions enriched for large granular lymphocytes, which suggests that these effector cells have a common morphology. In competition studies between 51Cr-labeled targets and unlabeled targets, both the infected and the uninfected fibroblasts competed for lysis of NK(HSV-1) and NK(FS) activity, whereas K562 cells competed poorly. In contrast, when 51Cr-labeled K562 cells were used, the unlabeled K562 cells competed well, but HSV-1-infected and uninfected fibroblasts competed poorly. Panning studies and complement elimination experiments using monoclonal antibodies were performed to describe cell surface markers on the NK cell populations. Treatment with an antibody to an la framework antigen reduced NK(HSV-1) but not NK(K562) activity. In contrast, the majority of NK(K562) effectors were recognized by antibodies to the E-rosette receptor (Lyt-3 and OKT11A), whereas NK(HSV-1) activity was much less sensitive to this antibody. OKM1, OKT10, and Leu-7 (HNK-1) markers were found on a portion, but not all, of the cells that lysed both the HSV-FS and K562 targets, while treatment with HLA plus complement totally abrogated both NK activities. Taken together, these data are consistent with the concept that human NK cells are heterogeneous and that we are dealing with at least three subpopulations of effector cells--one that kills the infected or uninfected fibroblasts; one that kills K562 cells; and a third population that may be able to kill all three targets. Patient studies provide additional evidence for heterogeneity within the NK cells that lyse the fibroblasts and K562 cells. We have studied a number of individuals who have normal NK activity with one target (HSV-FS or K562) but have low or no activity against the other. These patients provide strong evidence not only that NK cells are heterogeneous but also that these NK subpopulations can be regulated independently of each other in vivo.

Adult↗
PubMed1982

Prognostic value of the estrogen receptor level in pathologic stage I and II adenocarcinoma of the breast.

The relationship between estrogen receptor levels and recurrence of breast cancer was examined in 302 patients with adenocarcinoma of the breast, pathologic stage (PS) I and II. All 117 patients with PS II adenocarcinoma of the breast received adjunctive chemotherapy. In this series, there was no association between the estrogen receptor level and recurrence in either the 185 patients with PS I adenocarcinoma of the breast or the 117 patients with PS II adenocarcinoma of the breast. The most important prognostic variable was the presence or absence of axillary metastases.

Adenocarcinoma↗
PubMed1982

Macrophages and neoplasms: new insights and their implication in tumor immunobiology.

In this review, I have attempted to draw together some recent findings of current importance in tumor-macrophage interactions. The widespread distribution of macrophages through the body, the ease of monocyte mobilization to inflammatory sites, the exquisite synthetic machinery of the macrophage and its potent antitumor activity, when this can be evoked by nonspecific means, imply a critical role for cells of this lineage in regulation and control of the neoplastic state. These new insights into the immunobiology of the macrophage revive our hopes both for a keener understanding of the complexity existing between the host and its neoplasm and for the development of successful therapies based on scientifically proven rationales.

Animals↗
PubMed1982

Variability in the measurement of specific immunoglobulin E antibody by the RAST procedure.

This is a report of a study from the Committee on In Vitro Tests of the American Academy of Allergy, which evaluated variance of the RAST procedure when different allergic sera were tested by 12 Committee member laboratories using the Phadebas RAST kit (Pharmacia Diagnostics, Piscataway, N.J.) and when serial dilutions of a ragweed allergic sera were sent to nine different commercial laboratories in the U.S.A. The Phadebas RAST was found to differentiate high-, medium-, and low-titer allergic sera. The test was not useful in measuring smaller changes (less than 61%) in specific IgE antibody that might result from treatment with immunotherapy. Alternative methods of reporting the data, percent total activity and percent negative control, were not superior to the Phadebas RAST unit. Four of the commercial laboratories surveyed did not differentiate by their own measure of significance medium- from low-titer ragweed allergic sera.

Alternaria↗
PubMed1982

Evidence for DNA modification in the maintenance of X-chromosome inactivation of adult mouse tissues.

The role of DNA modification in the maintenance of mammalian X-chromosome inactivation was investigated by using the technique of DNA transformation in mammalian cells. The ability of inactive X-chromosome DNA from adult mouse tissues to act in transformation for the X-linked hypoxanthine phosphoribosyltransferase gene (Hprt) could be ascertained by utilizing a recently discovered electrophoretic variant form of the hypoxanthine phosphoribosyltransferase enzyme and a previously available X:autosome translocation. Our findings indicate that inactive X-chromosome DNA from several tissues of adult female mice is strikingly inefficient, in comparison to active X-chromosome DNA, in eliciting genetic transformation for hypoxanthine phosphoribosyltransferase. These results provide in vivo evidence that is consistent with DNA modification playing an important role in the maintenance of X-chromosome inactivation.

Animals↗
PubMed1982

A retrospective on the "New Perspective".

The working document entitled A New Perspective on the Health of Canadians, often referred to as the "Lalonde Report," was released in 1974. Its suggestion that present patterns of morbidity and mortality were not particularly amenable to health care interventions, and seemed rather to be the result of lifestyle, environment, or underlying biological patterns, has attracted a great deal of attention, both in Canada and elsewhere. This article examines the responses of various interested groups to the Lalonde Report, with particular attention to the assumptions and biases that each group brought to bear on the report, and to the conflicting perspectives on the report which resulted.

Canada↗
PubMed1981

Five year follow-up of effects of treatment of mild and moderate hypertension.

A five-year follow-up study of the effects of treating patients with both mild and moderate hypertension was performed. The patients were identified during a hospital-based community survey of hypertension. A total of 961 patients were divided into four groups. The first group, the controls, were age- and sex-matched normotensive subjects selected sequentially from the same survey. The second group were patients defined as well-controlled hypertensives; the third group were patients whose blood pressures were less well-controlled; and the fourth group consisted of patients who, for various reasons, were not treated and as such acted as an untreated control group. Both mortality and morbidity were considerably greater in the untreated patients than in the normal subjects. The well-controlled hypertensive patients showed no difference in either morbidity or mortality from normal subjects. The less well-controlled patients had a significantly greater cardiovascular morbidity but no excess mortality over groups 1 and 2. This was true for both mild and moderate hypertension and for women as well as men. These findings therefore confirm the conclusions of other recent studies that good control of hypertension at all levels and in both sexes is justified by the reduction in morbidity and that even less than excellent control is of considerable benefit.

Blood Pressure↗
PubMed1981

A U.S. reference for human immunoglobulin E.

The Committee on In Vitro Tests of the American Academy of Allergy has collected a large pool of human serum containing high titers of total IgE for the purpose of establishing a U.S. reference material. This pool is free from hepatitis B surface antigen. The serum pool has been subaliquoted, lyophilized and tested for total IgE content. The paper radioimmunosorbent test (PRIST) technique was used for this measurement. All laboratories used the same lot of reagents. The Second International Reference Preparation was used as the reference standard in each assay. Multiple replicates of the pooled sera was tested for total IgE content with one set of reagents by each of the 14 participating committee laboratories. The results for total IgE content (IU) of the vials were: mean of means, 899; median of means, 901; weighted mean, 898; with an overall coefficient of variation of 15.3%. This new IgE reference material is available to all laboratories for use as a primary reference standard from the Research Resources Branch, NIAID-NIH, Bethesda, MD 20205.

Humans↗