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Biomedical subjects

R A Beauchamp

Publications and source records attributed to R A Beauchamp.

8 recordsLinked to original sources
PubMed1993

Association between bovine collagen dermal implants and a dermatomyositis or a polymyositis-like syndrome.

OBJECTIVE: To determine whether an excess incidence of dermatomyositis or polymyositis or both exist in patients treated with injectable bovine collagen implants and to characterize the clinical picture. DESIGN: Historical cohort study (July 1980 through June 1988). PATIENTS: Patients were identified from personal experience or adverse reaction reports received by the manufacturer. SETTING: An 8-year period in the United States during which approximately 345,000 patients received implants. RESULTS: Eight patients with dermatomyositis and an additional patient with polymyositis were identified from approximately 345,000 patients receiving injectable bovine collagen implants from July 1980 through June 1988. The nine patients with dermatomyositis or polymyositis were diagnosed an average of 6.4 months (range, 0.7 to 24.9 months) after collagen implant or skin test exposure or both. Eight of the nine patients had a delayed-type hypersensitivity response at the test or treatment sites or both, and five of six patients tested were found to have increased serum antibodies to collagen. Compared with the general population, the incidence of dermatomyositis or polymyositis among collagen-treated patients was statistically increased (standardized incidence ratio, 5.05; 95% CI, 2.31 to 9.59; P < 0.0001). A similar analysis of the eight dermatomyositis case patients produced a standardized incidence ratio of 18.8 (CI, 8.1 to 37.0; P < 0.0001). Using a Monte Carlo simulation, an interval of 6.4 months or less from exposure to onset of disease was found to be an extremely rare event, occurring less than 72 times per one million simulation trials (CI, 57 to 91). CONCLUSIONS: Because these data suggest that an immunologic response to bovine type I or type III collagen or both caused this dermatomyositis or polymyositis-like syndrome, the risks versus benefits for the cosmetic use of collagen implants should be reassessed.

Adult↗
PubMed1983

The epidemiology of heat-related deaths, Texas--1950, 1970-79, and 1980.

A study of the deaths during a 1980 heat wave in Texas revealed death rates that were highest in males, the elderly, Blacks and those engaged in heavy labor, the latter two factors perhaps reflecting socioeconomic status. The data suggest that persistent high temperatures were related to death to a greater degree than the temperature peaks reached. Higher heat death rates in earlier years are believed to be attributable to the limited availability of air conditioning in those years.

Black or African American↗
PubMed1979

Comparison of bubble and membrane oxygenators in short and long perfusions.

Eighty patients had cardiopulmonary bypass (CPB), half having short (109 +/- 11 minutes) perfusions and half having long (188 +/- 14 min) perfusions. Twenty patients in each group were perfused with bubble oxygenators (Bentley, Harvey, or Galen) and 20 with membrane oxygenators (Modulung or Teflo). Hemodilution to a hematocrit value of 22.5% +/- 1.4% and hypothermia to 28 degrees +/- 2 degrees C were used in all patients. Complete hemograms, sequential multiple analyzer 18 tests, coagulation profiles, blood gases and pH, three immunoglobulins, and two complement fraction proteins were sampled as follows: three times before perfusion, one to ten times during perfusion, 1 hour immediately after perfusion, and 4, 24, and 48 hours postoperatively. Data in concentration terms were compared statistically and reported as mean and standard error for each subset. Additionally, rates of gain or loss were calculated in terms of quantity per liter of blood pumped per minute. During perfusion for both duration sets, use of a membrane oxygenator resulted in greater pump flows (4.55 +/- 0.15 L/min versus 3.75 +/- 0.11 L/min), lower total peripheral resistances (1,125 +/- 63 dynes.sec.cm-5 versus 1,652 +/- 115 dynes.sec.cm-5), and greater urinary outputs (9.4 +/- 1.1 ml/min versus 2.2 +/- 0.6 ml/min) than in the bubble oxygenator subsets. Comparisons of measured and calculated data in the immediate postperfusion interval showed no differences between bubble and membrane oxygenator subsets for short perfusions. In long perfusions, the membrane subset had lower plasma hemoglobin and white cell concentrations and generation rates, smaller (3 to 8 1/2 times) losses of IgG, IgM, C3 and shed blood necessitating less transfusion, and greater C4 losses. The membrane oxygenator systems used were more complex and costly and offered no advantages for short perfusion in adults. In anticipated long perfusions or where bleeding may be a problem, a membrane oxygenator appears more efficacious than bubble systems. For perfusions of less than 2 hours, membrane oxygenators had no biochemical or hematologic advantage over the bubble devices used in this study.

Blood Cell Count↗
PubMed1978

Durability of prosthetic heart valves.

Accelerated fatigue testing of clinical heart valves has been performed at cyclic rates of 33 to 35 cycles per second at 37 degrees C using water for non-biological valves and glutaraldehyde solutions for tissue valves. Flows were in the physiological range, and the pressure difference across each valve during closure was 100 +/- 25 mm Hg. The results showed that major fatigue occurred for the Starr-Edwards 2320 at 150 million cycles, the Hufnagel trileaflet at 124 million cycles, the Björk-Shiley Delrin disc at 140, the Björk-Shiley Pyrolite disc at 973, the Beall 103 at 60, the Hancock porcine at 62, the Carpentier-Edwards porcine at 34, and the Ionescu-Shiley porcine pericardial prosthesis at 65 million cycles. The Lillehei-Kaster was removed after 762 million cycles without discernible wear. Three facts emerged from the testing data: (1) the component worn in vitro wears in vivo; (2) the sites of in vitro fatigue on the component are identical to clinical specimens; and (3) those valves that have high durability in vitro have given similar performance in patients. The in vitro and clinical data for tissue valves do not correlate. The possible reasons for the discrepancy are discussed, and a note of caution is made regarding realistic expectations of clinical durability of tissue valves.

Bioprosthesis↗
PubMed1975

Fat and solid filtration in clinical perfusions.

The purpose of this study was to define the fat filtration characteristics of a packed polyester wool filter when used alone in the cardiotomy suction (12 cases) and the arterial lines (10 cases) during clinical hemodilution, extracorporeal circulation. The pressure gradient-flow relationship and the efficiency of removal of fibrin microparticles were first ascertained in vitro. Total fat was extracted from the polyester wool with a Soxhlet device. Whole blood and plasma lipids were measured before and after bypass. The results showed a 23 mm. Hg pressure drop across a wool filter with a water flow rate of 5 L. per minute and a 40 to 52 percent efficiency for fibrin microparticles 15 to 250 mu. The total lipid extracted from the cardiotomy filters averaged 376 plus or minus 72 mg. compared with 512 plus or minus 95 mg. in the arterial line filters, although there was no statistically significant difference. Additionally 245 plus or minus 101 mg. of nonlipid material were extracted from the arterial line filters. The postperfusion whole blood contained a higher concentration of lipid than the preperfusion blood when corrected for dilution. It was concluded that significant quantities of solids, two thirds of which were fat, were removed by packed polyester wool filters during total body perfusions. Most of the fat was derived from the cardiotomy suction system. The amount of filtered fat and solids increased with perfusion time. These findings endorse the concept of cardiotomy filtration during extracorporeal circulation.

Blood↗
PubMedDate not supplied

Acute health effects in a community after a release of hydrofluoric acid.

Approximately 3,000 persons were evacuated from a Texas community after 24,036 kg (53,000 lb) of caustic hydrofluoric acid (HF) were released from a nearby petrochemical plant. Emergency room and hospital records of 939 persons who were seen at two area hospitals were reviewed. Most persons who presented at the emergency rooms were female (56%) or black (60%), and their mean age was 33.9 y. The most frequently reported symptoms were eye irritation (41.5%), burning throat (21%), headache (20.6%), and shortness of breath (19.4%). Physical examination results were normal for 49% of the cases; however, irritation of the eyes, nose, throat, skin, and lungs were noted on other exams. Decreased pulmonary function was demonstrated by pulmonary function tests (forced expiratory volume in the first second, less than 80% of predicted value, 42.3%); hypoxemia (pO2 less than 80 mm Hg, 17.4%) and hypocalcemia (less than 8.5 mg/dl, 16.3%) were also noted. Ninety-four (10%) of the cases were hospitalized, and more than 83% of all cases were discharged with a primary diagnosis of "HF exposure." There are several reports of individuals who are acutely and chronically exposed to HF; however, we are unaware of other published reports that describe exposure of a community to HF. This incident represented a unique opportunity to study the immediate health impact on a community of residents who were exposed to a hazardous materials release. Results of this analysis suggest that (a) initial health problems should be followed up, (b) any long-term health effects of HF exposure must be assessed, and (c) the health impact on the population at risk should be determined.

Adolescent↗