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Biomedical subjects

R Evans

Publications and source records attributed to R Evans.

At least 451 records · Page 25Linked to original sources
PubMed1977

Effect of X-irradiation on host-cell infiltration and growth of a murine fibrosarcoma.

Whole body X-irradiation (400 rad) of C57BL mice, either before or after i.m. implantation of the syngeneic fibrosarcoma, FS6, influenced both the growth of the tumours and their cellular composition, particularly their macrophage content. Pre-irradiation resulted in slower initial growth of tumours, and a concomitant lack of host-cell infiltration, but when tumours began to grow at a rate parallel to controls infiltration by host cells was demonstrable. Similarly, irradiation of the tumour-bearing host resulted in a temporary cessation of growth, and a decrease in the macrophage content, which did not return to control levels for 2-3 weeks after irradiation. The significance of these results is discussed in relation to the possibility that infiltrating host cells, particularly macrophages, may stimulate the growth of this tumour.

Animals↗
PubMed1976

Inhibition of antibody-dependent cellular cytotoxicity and immunoglobulin synthesis by an antiserum prepared against a human B-cell Ia-like molecule.

Rabbit antisera to the human B-cell-specific antigen complex, p23,30, was used to define further the functional heterogeneity of isolated human lymphocyte subpopulations. Specific depletion of p23,30-bearing cells from Ig-negative cell populations and Ig-negative, E rosette-negative (Null) populations by either complement-mediated lysis or by physical separation on goat antirabbit Fab immunoabsorbent columns, eliminates the antibody-dependent cellular cytotoxic (ADCC) function. Furthermore, binding of anti-p23,30 serum to the effector cell surface inhibits ADCC but does not interfere with EA rosette formation. Apparently p23,30 represents a cell surface site which is distinct from the Fc receptor but which is important in the triggering of ADCC. In addition, depletion of p23,30-bearing cells from unfractionated cell populations, Ig-positive B-cell populations and Ig-negative, E rosette-negative (Null) populations eliminates the capacity of these populations to secrete immunoglobulin during subsequent culturing. Thus both the Ig-secreting cells and the ADCC effector cells within the Ig-negative, E rosette-negative (Null) population reside in the same population of cells which bears the p23,30 antigen.

Antibody Formation↗
PubMed1976

Child-rearing attitudes of subjects who vary in guilt.

The present study sought to determine whether high- and low-guilt Ss differ in their child-rearing attitudes. High-guilt Ss were found to be more likely to prefer an overprotective orientation combined with harsh punitive control. In general, attitudes of the high-guilt Ss were seen as more likely to produce psychological disturbance in their children.

Attitude↗
PubMed1976

The effect of atropine and albuterol aerosols on the human bronchial response to histamine.

This study was designed to determine whether histamine-induced bronchoconstriction in human asthmatics is mediated by the parasympathetic nervous system and involves cholinergic pathways. Inhalation challenges were performed on 14 adult asthmatic patients using the standardized procedure for inhalation challenge recently recommended by the Asthma and Allergic Disease Centers panel. The effect of pretreatment with either aerosolized atropine sulfate or aerosolized albuterol, a specific beta-2 adrenergic agonist, was studied. The comulative units of histamine required for induction of a positive bronchial response (20% or greater drop in FEV1 from baseline) was used as the basis of comparison of the effects of these drugs. This value was expressed as the PD20-FEV1 to histamine. Analysis of the data showed that aerosolization of sufficient atropie to effect a cholinergic blockade, as shown by inhibition of the bronchial response to inhaled methacholine, only minimally affected the bronchial response to histamine (p less than 0.05). However, the administration of albuterol markedly shifted the response to histamine (p less than 0.005). Although there was a statistically significant change in the mean PD20-FEV1 to histamine following atropine blockade, this effect was small in comparison to that which could be demonstrated with a beta agonist. It would thus appear that the major influence of histamine is not through cholinergic pathways.

Administration, Intranasal↗
PubMed1976

The effect of immunotherapy on humoral and cellular responses in ragweed hayfever.

The effect of specific immunotherapy on several in vitro responses to ragweed antigen E has been evaluated in 17 atopic patients with ragweed hayfever. The methods employed were leukocyte histamine release, measurement of specific IgE anti-ragweed antibody and specific IgG anti-ragweed antibody, lymphocyte proliferation, and the production of two lymphocyte mediators (migration inhibitory factor and mitogenic factor). The duration of treatment and symptom improvement were also recorded for comparison. Immunotherapy was associated with a decrease in leukocyte sensitivity for histamine release to ragweed antigen E in a majority of the patients. In addition, there was a significant decrease in IgE anti-ragweed antibody and a significant increase in IgG anti-ragweed antibody. Immunotherapy also resulted in a significant decrease in lymphocyte responsiveness to ragweed antigen E as measured by proliferation and the production of mediators. Symptomatic improvement was best correlated with the presence of IgG anti-ragweed antibody responses. The production of this antibody was also associated with a decrease in lymphocyte responsiveness. The results of this study indicate that specific immunotherapy in ragweed-sensitive patients induces alterations in immunologic reactivity to ragweed antigen in vitro. This response is antigen specific, includes elements of both humoral and cellular immunity, and may account for the clinical improvement that is often observed in patients who undergo this form of therapy.

DNA Replication↗
PubMed1976

Quantitative levels of immunoglobulin E in advanced tuberculosis.

Quantitative levels of immunoglobulin E (IgE) were determined in samples of sera obtained from 29 patients with proven moderate to far-advanced tuberculosis. The sensitive radioimmunoassay test for IgE was used. Statistical analysis of the results revealed no difference in IgE values as compared to a control group of normal sera. In contrast to other chronic pulmonary infections, such as bronchopulmonary aspergillosis, the IgE level in pulmonary tuberculous infection is of no diagnostic significance. Simultaneous determination of levels of immunoglobulins G, A, M, and D (IgG, IgA, IgM, IgD) in these same sera by radial immunodiffusion showed elevated IgG and lowered IgM levels in the tuberculous patients, confirming previous studies. The significance of these alterations in immunoglobulin levels is unclear and may represent a secondary phenomenon rather than a primary host response.

Adult↗
PubMed1976

Humoral immunity of parasitized, malnourished children.

The nutrition, intensity of parasitism, complete blood count, and the serum immunoglobulin concentration of 63 children were studied. Hyperimmunoglobulinemia was present in the vast majority of subjects regardless of their nutritional status. The IgA and IgM concentrations were moderately increased, the IgG was increased threefold, and the IgE was markedly increased in concentration. The concentrations of the immunoglobulins were related significantly to the intensity of parasitism.

Ascariasis↗
PubMed1976

Studies on a new polyether antibiotic, Ro 21-6150.

A new polyether antibiotic, Ro 21-6150, has been isolated from culture broths of Streptomyces hygroscopicus, strain X-14563. Ro 21-6150 has ionophore properties and is active in vitro against gram-positive bacteria.

Animals↗
PubMed1976

Cyclophosphamide, adriamycin, methotrexate, and procarbazine (CAMP)--effective four-drug combination chemotherapy for metastatic non-oat cell bronchogenic carcinoma.

Twenty-three patients with metastatic non-oat cell bronchogenic carcinoma (MNOBC) were treated with cyclophosphamide, adriamycin, methotrexate, and procarbazine (CAMP) after radiation therapy. Objective responses were seen in 11 of 23 patients (48%) with a projected median survival time of 12.5 months for responding patients and patients with stable disease. Lung, liver, and cutaneous sites of involvement proved to be highly responsive; bone involvement was less responsive. CAMP is an effective combination in the treatment of MNOBC and its use in patients with less advanced disease should be explored.

Adenocarcinoma↗
PubMed1975

Macrophage-mediated cytotoxicity: its possible role in rheumatoid arthritis.

The association of macrophages with destructive processes in transplantation and tumoral, bacterial, and protozoan immunity illustrates their versatility in different situations. Their participation in inflammatory responses, including graft rejection and rheumatoid arthritis, would guarantee focal areas of high concentrations of hydrolytic enzymes and other macrophage products. That erosion of synovial tissue occurs in the presence of enzymes known to be associated with macrophages suggests that the large numbers of infiltrating macrophages and destruction of synovial tissue may be related.

Animals↗
PubMed1975

Erotic stimuli and aggression: facilitation or inhibition.

The present experiment attempted to reconcile previous results on the relationship of erotic stimuli and aggression. Subjects were either insulted or not insulted prior or subsequent to observing erotic stimuli of varying levels of arousal inducements. It was found, in support of prior research, that mildly erotic stimuli had an inhibiting effect on aggression when viewed subsequent to anger arousal, whereas highly erotic stimuli tended to maintain aggression at a level similar to nonerotic exposure. Prior viewing of erotic stimuli, however, had a facilitative effect on aggressive behavior. It was proposed that erotic stimuli have two components (arousal and attentional shift) that interact with anger arousal to either inhibit or facilitate aggressive behavior. The article considers the implications of this two-component system for future research on erotic and aggressive stimuli.

Aggression↗