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Biomedical subjects

S R Smith

Publications and source records attributed to S R Smith.

At least 343 records · Page 19Linked to original sources
PubMed1982

The effect of surgical drainage materials on colonic healing.

The effect of surgical drainage materials on rat colonic healing has been investigated in a prospective randomized and controlled study. Latex, silicone rubber (Silastic), polyvinylchloride (PVC) and polytetrafluoroethylene (Teflon) tubes were implanted alongside a colonic anastomosis and compared with a 'no drain' group using mechanical and histological assessments. There was a significant increase in anastomotic leakage in the latex group in which there appears to be a local inhibition of healing. Silastic, PVC and Teflon were not found to interfere with healing. The continued use of latex drains in colonic surgery is therefore questioned.

Animals↗
PubMed1982

The clinical value of immunohistochemically demonstrable CEA in breast cancer: a possible method of selecting patients for adjuvant chemotherapy.

The production of carcinoembryonic antigen (CEA) by human breast cancer tissue has been studied in relation to the prognosis of patients with breast cancer. All of the patients were in a controlled trial of adjuvant chemotherapy for the treatment of operable breast cancer. CEA was studied in primary tumours and axillary node metastases from these patients using an immunoperoxidase (PAP) method. Sections of 290 primary carcinomas and 217 axillary metastases were examined for CEA. The CEA status of the primary tumours was of no value as a prognostic indicator nor in the selection of patients for chemotherapy. In contrast, patients could be divided into 3 groups on the basis of the CEA results in the axillary nodes. In one group, in which cases were strongly positive for CEA (24% of the total) the prognosis, as reflected by recurrence free survival, was relatively good and chemotherapy produced no further advantage. In another group in which cases were weakly positive for CEA (18% of the total) the prognosis was poor but chemotherapy produced significant improvement. In a third group, in which cases were negative for CEA (58% of the total) the prognosis was poor and was not improved by chemotherapy, at least in the short term. Thus, the CEA status of axillary metastases may be clinically useful.

Breast Neoplasms↗
PubMed1982

Indications for mediastinal lymph node evaluation.

Successful surgical therapy for bronchogenic carcinoma depends upon an accurate lymph node assessment. Criteria were developed and reported to identify patients who would benefit from mediastinoscopy prior to thoracotomy. This report summarizes the prospective use of the criteria between 1974 and 1977 and the total experience from 1970 to 1977. Selection of patients for prethoracotomy mediastinal evaluation is primarily based on chest roentgenogram and cell type. Left upper lobe lesions meeting the criteria were submitted to mediastinotomy if mediastinoscopy was negative. Eighty-seven potentially resectable lesions were evaluated prospectively, and the total experience included 202 patients. Mediastinal metastasis occurred in 39 patients of the current and 82 patients of the total series. When metastases to the mediastinum were documented, roentgenographic evidence of metastasis was seen in 20 of 39 (51 percent) of the current and 44 of 82 (54 percent) of the total series. There was roentgenographic evidence of metastasis in central lesions, peripheral masses, and small peripheral lesions with mediastinal metastases in 50 percent, 25 percent, and 78 percent of the cases, respectively. Mediastinal metastases were reported 80 percent of the time before thoracotomy using these criteria. The use of mediastinotomy on left upper lobe lesions identified six of seven of the unresectable cases missed by the mediastinoscopy. The criteria will identify patients at high risk for mediastinal metastases who benefit from prethoracotomy surgical evaluation.

Adenocarcinoma↗
PubMed1982

Metaphyseal changes in Perthes' disease: an experimental study.

Glass microspheres were introduced into the hind-limb circulation of 6 immature Gottingen mini-pigs so as to result in ischaemia of the developing proximal femur. Radiological abnormalities similar to those seen in the metaphysis in Perthes' disease were produced in 1 animal. Histological examination shows that these resulted from arrest of a portion of necrotic growth plate within the metaphysis with a corresponding defect within the growth plate. This was associated with ischaemia of the adjacent epiphysis. These changes support the suggestion that metaphyseal change in Perthes' disease are secondary to epiphyseal ischaemia. It is possible that the growth-plate defect may be the precursor of intrinsic deformity of the femoral head.

Animals↗
PubMed1981

Severe hypertriglyceridaemia responding to insulin and nicotinic acid therapy.

A patient with unusually severe hypertriglyceridaemia (serum concentration initially 258 mmol/l or 22600 mg/dl) and hypercholesterolaemia is reported and discussed. The triglyceride elevation was found to reside within the very low density lipoprotein fraction and was probably attributable to the combination of diabetes mellitus and familial hypertriglyceridaemia. Treatment with insulin and restriction of dietary carbohydrate led to a 50% reduction in the triglyceride concentration, and the addition of nicotinic acid in modest doses led ultimately to a complete normalization of the patient's lipid values. A close correlation was noted between the falling triglyceride concentration and the rising serum sodium concentration during the course of successful therapy. Overall, it is felt likely that this patient's severe and reversible hypertriglyceridaemia was on the basis of excessively rapid lipolysis leading to high concentrations of very low density lipoprotein production. Combined therapy with insulin and nicotinic acid is recommended for other patients of this nature.

Diabetes Complications↗
PubMed1981

Comparative effects of azathioprine, cyclophosphamide and frentizole on cellular immunity in mice.

This report extends previous observations on the immunosuppressive properties of cyclophosphamide (CPA), azathioprine and frentizole (15) to include murine models of cellular immunity. Systemic and local graft vs host reactions (GVHR) were most effectively suppressed by CPA. In contrast to frentizole, both CPA and azathioprine were found to inhibit the proliferation of parental T-cells in a systemic GVHR. However, CPA was the only agent capable of inhibiting the proliferation of T-cells following contact sensitization with oxazolone. Mice pretreated with a high dose of CPA or frentizole prior to inoculation with the murine sarcoma virus exhibited accelerated tumor growth. However, there was no accelerated growth of murine sarcoma virus induced tumors or an SaI spindle cell fibrosarcoma during rather prolonged therapy with immunosuppressive doses of CPA, azathioprine or frentizole. Normal mice treated with CPA showed a more drastic reduction in lymphoid elements of the spleen and thymus than mice treated with azathioprine or frentizole. Studies on the mitogenic responsiveness of spleen cells obtained from normal mice after an eight day course of therapy suggested that CPA has some selectivity of action on B-cells and azathioprine on T-cells.

Animals↗
PubMed1981

An innovative family medicine clerkship.

A clinical clerkship in family medicine at Brown University has been developed utilizing many innovative educational modalities. These include games, simulations, group problem solving, research projects, videotaping, case presentations, field trips, sensitivity sessions, computer assisted instruction, patient management problems, slide-tape shows, and direct clinical experiences. These modalities are described together with a new approach to evaluation. Students' evaluations of the clerkship have been excellent, providing evidence that this clerkship offers a model of learning that is both effective and enjoyable.

Education, Medical, Undergraduate↗
PubMed1980

Parity and breast cancer: evidence of a dual effect.

Epidemiological studies have shown that early first pregnancy reduces the risk of developing breast cancer, which indicates that initiation of the disease occurs at an early age. Thus the subclinical lesion of breast cancer might already be present in the breast before childbearing begins and the growth of any such focus might be modified by the endocrine changes of pregnancy. To test this hypothesis the relation between parity and age at presentation was studied in 341 unselected patients with breast cancer presenting to a single clinic. The mean age at presentation was 5.2 years lower in parous than nulliparous women (p < 0.001) and fell with increasing parity. It is concluded that reproductive history influences not only the risk of breast cancer but also the latent interval of a proportion of breast carcinomas.

Adolescent↗
PubMed1980

Patient management by telephone: a training exercise for medical students.

An instructional exercise in telephone management of medical problems using experimental and didactic techniques was designed for medical students taking a family medicine clerkship. The effectiveness of this curriculum was evaluated by comparing the students' proficiency against a standard established through the use of a Delphi group opinion technique. This study indicates that formal training experiences for medical students in managing telephone complaints in a family practice setting can improve the students' performance.

Education, Medical, Undergraduate↗
PubMed1979

Comparative effects of azathioprine, cyclophosphamide and frentizole on humoral immunity in mice.

Data is presented comparing the activities of three immunosuppressive agents, cyclosphosphamide, frentizole and azathioprine in models of humoral immunity in mice. Cyclophosphamide and frentizole suppressed the primary and secondary plaque forming cell responses to sheep erythrocytes at lower doses than did azathioprine. Prolonged suppression of serum antibody titers occurred following short-term therapy with cyclophosphamide or frentizole, but not azathioprine. Azathioprine was also the least effective agent in suppressing a primary response to the T-independent antigen, trinitrophenylated lipopolysaccharide. All three agents were found to inhibit the induction and activity of suppressor cells at immunosuppressive doses.

Animals↗