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Biomedical subjects

B MacPherson

Publications and source records attributed to B MacPherson.

8 recordsLinked to original sources

Suramin inhibits the mixed lymphocyte reaction by suppressing lymphokine production.

New compounds with a greater potency than cyclosporin A (CyA) for thwarting host rejection of organ transplantation are being sought. Suramin sodium may be a novel drug to prevent or delay graft rejection and graft-vs-host disease (GVHD), because of its in vitro and in vivo immunosuppressive properties. Since the allogeneic mixed lymphocyte reaction (MLR) is considered to be the in vitro counterpart of the initial T-lymphocyte recognition and response to allogeneic histocompatibility antigens on grafted tissue or organ and to GVHD, we initially evaluated the in vitro suppressive effect of suramin in the allogeneic MLR. Suramin inhibited the H-2- and HLA-incompatible MLR in a dose-dependent manner. The suppressive effect was observed both in the primary and in the secondary MLR. The suppression of the MLR by suramin is due predominantly to the inhibition of interleukin-2 (IL-2) production by the responding T cells.

Animals

Pressure, flow and resistance characteristics of the pediatric Storz-Hopkins bronchoscopes.

Poiseuille's law describes the relationship between pressure and the flow of a gas or liquid of known viscosity through a conduit of known length and radius. In clinical bronchoscopy, resistance varies directly with changes in viscosity of the inspired gas and the length of the bronchoscope. According to Poiseuille's law, resistance varies inversely to the fourth power of the radius of the bronchoscope. Flow-pressure curves were generated for commonly used pediatric Storz-Hopkins bronchoscopes with and without telescopes and the resistance of each system was calculated. Extremely high resistance is encountered with the 2.5 x 20 cm bronchoscope with telescope in place, a fact that most pediatric endoscopists are well aware of. However, comparable resistance is encountered when the 3.5 x 30 cm bronchoscope is used with the telescope in place, a fact not well appreciated by most clinicians.

Airway Resistance

Effectiveness of a controlled drinking self-help manual: one-year follow-up results.

Following the description of six-month follow-up results by Heather et al. (1986), this article reports one-year follow-up for a cohort of media-recruited problem drinkers sent either a controlled drinking self-help manual or a general advice and information booklet. Among those remaining in the sample, mean reduction in drinking at six months had been retained at the one-year point. This stability of reduced consumption included respondents showing evidence of late dependence or high consumption at initial assessment. When respondents who had received other forms of treatment had been excluded, the results confirmed the superior effectiveness of the self-help manual in enabling problem drinkers to reduce consumption. Evidence for a superior outcome among respondents interviewed by telephone, rather than contacted solely by post, was again observed. Some limited evidence is presented as to the reliability and validity of self-reports of consumption in the main sample.

Alcohol Drinking

Reducing adolescent smoking: a comparison of peer-led, teacher-led, and expert interventions.

To test the effectiveness of a psychosocial strategy of smoking deterence on seventh grade students, the School Health Education Development project implemented peer-led, teacher-led, and expert-led interventions in six Vermont schools. Four additional schools served as control groups. The teacher-led approach reduced the rate of smoking onset and the intention to smoke in the future among highly vulnerable females but not among males. The peer-led approach reduced the behavioral intention to smoke for both sexes but did not affect current smoking behavior. The expert-led approach did not produce favorable effects. Both the peer-led and teacher-led interventions had positive, though not significant, effects on student perception of locus of control. In the control schools, females experienced higher levels of smoking onset than males. Generally, the study points toward further development of a teacher-led approach to smoking deterence based on the theory of adolescent psychosocial development and the principle of continuous reinforcement.

Adolescent

Hematologic findings in cases of mammary cancer metastatic to bone marrow.

The hematologic findings in 22 cases of mammary cancer metastatic to bone marrow are presented. Cancer of the breast was the most frequent neoplasm metastatic in bone marrow in this study of 2,878 bone-marrow examinations. All 22 patients who had carcinoma of the breast metastatic to bone marrow had clinical, radiographic, or hematologic evidence of widespread metastatic disease. Peripheral blood was abnormal in 58% of the cases, and in most of these cases two or more abnormalities were present. Bone-marrow biopsies were superior to particle sections and aspirates in identifying tumor, but correlations among all modalities were necessary for proper interpretation. Although the morphologic features of tumor cells in sections and smears were quite characteristic for carcinoma of the breast, pitfalls in interpretation were numerous and should be recognized. The mean survival time of these patients was only 6.9 months after identification of bone-marrow metastases. The significant response to chemotherapy obtained with some individuals, however, should encourage aggressive therapy of this disorder.

Bone Marrow Diseases

Experimental colitis.

Ulcerative colitis and Crohn's disease are complex, problematic diseases of unknown etiology in man, and appropriate experimental models would be useful in elucidating their pathogenesis and treatment. Although there have been numerous attempts to produce inflammatory ulcerative colonic disease in laboratory animals resembling those human disease forms, none has been entirely successful. Investigators have conducted experiments involving almost every etiological factor suggested for initiation of these diseases. The methods reviewed in this paper include production of experimental colitis by vascular impairment, and immunological methods such as bacterial infection, allergic reactions, direct and indirect hypersensitivity reactions, as well as autoimmune mechanisms. The results of carrageenan-induced colitis, irradiation, dietary, and drug-induced techniques are also discussed and the frequency and nature of spontaneous colonic lesions in animals is summarized.

Adult