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Biomedical subjects

J Long

Publications and source records attributed to J Long.

At least 127 records · Page 7Linked to original sources

Urban and rural Indian drinking patterns: implications for intervention policy development.

Alcohol misuse has taken on epidemic proportions among some (but not all) American Indian populations. Cultural, psychological, socioeconomic and genetic etiologies have been offered to explain this social phenomenon. This study identifies the relative strengths of these causal models to differentiate among both current and lifelong drinking career patterns. Further, antecedent and drinking level differences between urban and rural Indian populations in California are described. Age, sex, level of stress as measured by the Cornell Medical Index, percent of Indian ancestry and level of drinking in the family of origin are less powerful predictors of drinking level. Policy implications of these findings include: the development of intervention programs which involve members of the patient's support network, accelerated interventions in rural Indian communities and mid-level interventions among younger and less debilitated, but identifiably "at risk", populations.

Adolescent↗

Cytoxicity of erythrocyte ghosts loaded with ribosome-inactivating proteins following fusion with CHO cells.

The ribosome-inactivating proteins gelonin, Momordica charantia inhibitor, pokeweed antiviral protein, and one from Saponaria officinalis were enclosed in human erythrocyte ghosts. The proteins once trapped in ghosts and fused with CHO cells inhibited colony formation at concentrations of approximately 1 ng/ml (3 X 10(-11) M), whereas the free proteins only had an effect at concentrations of greater than 1 microgram/ml.

Animals↗

The effect of antisecretagogues on gastric microflora.

We examined the effect of cimetidine in altering gastric microflora in patients undergoing gastric resection for peptic ulcer disease. Ten patients had administration of cimetidine stopped at least six hours before surgery. Their mean gastric pH was 2.02 +/- 1.51, and 0.4 +/- 0.97 organisms were isolated per patient. Ten patients were maintained on a regimen of cimetidine and their mean gastric pH was 5.69 +/- 1.80, with 3.2 +/- 1.62 organisms isolated per patient. We reached the following conclusions: cimetidine alters the gastric pH of preoperative patients; cimetidine therapy is associated with an increase in gastric flora; stopping administration of cimetidine six hours before surgery reacidifies the stomach, decreases the number of organisms isolated from the stomach, and decreases the risk of septic complications.

Bacteria↗

Effect of healing on small internal diameter arterial graft compliance.

Porosity is an essential component for long term function of small internal diameter synthetic vascular prostheses. Theoretically, porosity is required for healing by providing a scaffold for ingrowth of periprosthetic tissues. Porosity may be required for transfer of fluids and ions in prostheses even if tissue ingrowth does not occur. Increased permeability of vascular grafts has been shown to enhance tissue incorporation. Implants with pore sizes greater than 10 microns but less than 45 microns become ingrown with fibrohistiocytic tissue and capillaries. Implants with pore sizes greater than 45 microns are ingrown with organized fibrous tissue and minimal histiocytic response. The phenomenon of differential ingrowth may have important functional significance. Prostheses which heal with organized fibrous tissue have the potential for long term contracture, strangulation of vascularity and calcification. Fibrohistiocytic tissue has low mechanical strength and does not appear to contract or calcify. Elastomeric microporous vascular prostheses which are minimally ingrown or ingrown with fibrohistiocytic tissue maintain compliance after months of implantation. This study was designated to determine the effects of healing on the compliance of small internal diameter vascular replacements and to correlate the compliance to patency rates.

Animals↗

Thrombogenicity and the interaction of proteins, platelets and white cells.

Radioactive labeled protein and platelet studies suggest that an ideal vascular surface absorbs albumin and prevents platelet adherence and aggregation. This study examines the interaction of serum and plasma proteins, white cells, and platelets in the thrombotic response to small internal diameter vascular prostheses. Thirty-seven replamineform silicone rubber vascular prostheses, 4 mm internal diameter and 6 cm length, had 5% aspirin and 5% theophylline by weight dispersed in a luminal coating (D); the remaining 37 control (C) prostheses had an identical silicone rubber coating without drugs. Scanning electron and darkfield microscopy confirmed similar surface topography in C and D grafts. One C and one D graft were studied in parallel using a modified canine arteriovenous fistula. Consistently, D prosthesis had increased bleeding through the graft wall. The 7 serum and 8 plasma experiments demonstrated greater accumulation on the D prostheses, the greatest deposition occurring within the first 30 minutes. In 8 platelet experiments, D grafts accumulated more radioactivity at both the 5 and 30 minute intervals. Six mononuclear and 8 PMN experiments had less accumulation on the D grafts at 15 minutes and no consistent difference at 60 minutes. Elution of C and D Grafts demonstrated significant drug levels in only the D grafts at the beginning of the experiments and after 15 minutes of exposure of blood. We conclude: (1) aspirin and theophylline have an effect on the initial interaction of plasma proteins, platelets and white cells in the thrombogenic response, (2) the effect diminishes as time released drug levels decrease.

Animals↗

Noninvasive evaluation of peripheral vascular disease using transcutaneous oxygen tension.

Transcutaneous oxygen tension (PtcO2) was used for noninvasive determination of blood supply in 25 patients evaluated for peripheral arterial disease. PtcO2 values were compared with segmental Doppler pressure, pulse volume recording, pulse reappearance time, and angiography in patients being evaluated for wound healing problems, amputations, and peripheral bypass procedures. PtcO2 was measured using a heated (45 degrees C) Clark polarographic electrode to quantitate the oxygen which diffuses from the dermal capillaries to the skin surface. Control PtcO2 values recorded over the chest or shoulder taken while patients were breathing room air were 78 +/- 8 mm Hg. PtcO2 values greater than 50 mm Hg predicted success for levels of amputation and for wound healing without reconstructive procedures; values of 40 mm Hg or less were associated with continued wound problems and complication after amputation. Increased PtcO2 values after vascular reconstruction of the legs predicted improved clinical status on follow-up examinations up to 6 months. PtcO2 predicted the extent of vascular disease as well as the other noninvasive tests and angiography. We conclude that (1) PtcO2 tension is a simple, accurate, noninvasive method to determine the appropriate level of amputation, wound healing potential, and effectiveness of bypass procedures, and (2) PtcO2 values correlate well with angiography and noninvasive evaluations.

Aged↗

A new pressure measuring system for cushins and beds--with a review of the literature.

An interface pressure measuring device for the assessment of subject-cushion interface pressures at ten points has been described. Preliminary trials using 12 healthy subjects on four cushions and three spinal injury patients on six cushings, has been carried out. It was also found that the water and foam cushion distributed the pressure over a large area than the foam cushions.

Animals↗

Limited surgical excision as the basis of a comprehensive therapy for cancer of the breast.

A comprehensive program of therapy has evolved with collaborating roles for surgery, pathology, radiotherapy, and chemotherapy. Our experience includes 131 patients with breast cancer treated at the Massachusetts General Hospital since 1956 by limited excision of the cancer. The tumors of 10 patients were noninvasive or sluggishly so; the patients received no further therapy. Because of the invasive character of their tumor, 121 patients received heavy postoperative irradiation. In 12 of these 121, the irradiation has been followed by immediate and prolonged chemotherapy. It is too soon to judge the effect of the chemotherapy, but survival rates of those treated by limited excision and primary irradiation compare favorably with those of patients treated by radical mastectomy.

Adult↗