The coronary blood flow and vascular resistance responses to static hindlimb exercise were studied in 11 anesthetized dogs after beta- and combined alpha- and beta-adrenergic blockade to determine if this stress causes coronary vasoconstriction. After beta-blockade static exercise increased the blood pressure and double product, but decreased the right and left ventricular (LV) coronary blood flow and increased the coronary vascular resistance. These vascular changes primarily occurred in the epicardial and mid-myocardial but not the endocardial layers of the LV. Following combined alpha- and beta-adrenergic blockade, the systemic hemodynamic and coronary flow and resistance changes were abolished. These data suggest that alpha-adrenergic mediated coronary vasoconstriction occurs during static hindlimb exercise in dogs.

Adrenergic alpha-Antagonists↗

PubMedDate not supplied

Early cardiovascular adaptation to zero gravity simulated by head-down tilt.

The early cardiovascular adaptation to zero gravity, simulated by head-down tilt at 5 degrees, was studied in a series of 10 normal young men. The validity of the model was confirmed by comparing the results with data from Apollo and Skylab flights. Tilt produced a significant central fluid shift with a transient increase in central venous pressure, later followed by an increase in left ventricular size without changes in cardiac output, arterial pressure, or contractile state. The hemodynamic changes were transient with a nearly complete return to the control state within 6 hr. The adaptation included a diuresis and a decrease in blood volume, associated with ADH, renin and aldosterone inhibition.

Adaptation, Physiological↗

PubMedDate not supplied

A twelve-year clinical and immunologic evaluation of workers involved in the manufacture of trimellitic anhydride (TMA).

The spectrum of immunologic lung disease occurring in a population of 196 workers involved in the manufacture of trimellitic anhydride (TMA) was assessed from January 1976 through December 1987. Workers were evaluated clinically by history, blood counts and chemistries, chest x-ray, and pulmonary function studies. Immunologic tests included skin testing with trimellityl-human serum albumin (TM-HSA) and assay of total antibody (TA) and of IgE antibody binding of 125I-TM-HSA. Seventeen workers had IgE-mediated asthma/rhinitis with a positive prick test to TM-HSA and IgE antibody of 0.8-57 ng of TM-HSA bound/ml. Seven workers had a late respiratory systemic syndrome with TA from 760-56,000 ng of TM-HSA bound/ml. Four had both syndromes. Three had late onset asthma with TA of 3,700-10,000 and trace levels of IgE to TM-HSA. One had marked arthralgia and myalgia occurring hours after TMA exposure, without respiratory symptoms, with an elevated TA level of 24,000. Of 46 workers reporting no symptoms, 8% had low TA levels, while 16% of 113 with irritant symptoms had low TA levels. There was a reduction in the number of workers exhibiting an immunologic syndrome during 1982-1987-8% (7 of 85) compared to 23% (26 of 111) during 1976-1981--in spite of increased TMA production. This paralleled environmental control and worker education efforts. Cooperative research by an academic Allergy-Immunology program and industry has defined TMA clinical syndromes and provided methods of immunologic monitoring, resulting in a reduction in new cases in spite of increased production of TMA.

Adult↗

PubMedDate not supplied

A clinical and immunologic study of employees in a facility manufacturing trimellitic anhydride.

We conducted a 1-year cross-sectional survey of 474 employees of a large chemical manufacturing complex to relate trimellitic anhydride (TMA) exposure to serologic and clinical outcomes. In 1988-1989, employees were evaluated by history and immunologic assay of total (T) and IgE antibody to trimellityl human serum albumin (TM-HSA). All employees were assigned to a TMA exposure class, from 1 (highest) to 5 (lowest), by an industrial hygienist, independent of the clinical and immunological data. Thirty-two (6.8%) of 474 employees had a TMA immunologic syndrome, 31.6% with an irritant response and 61.6% with no symptoms. Twelve had asthma/rhinitis, 10 had the late respiratory systemic syndrome (LRSS), four had late onset asthma, one had late onset arthralgia, and five had a distant history of LRSS. Included in this survey of the entire work force were 321 new enrollees, who had not joined the previous (1976 to 1988) voluntary surveillance program. Only four (1.3%) of the new enrollee group had a TMA immunologic syndrome. Among new enrollees, there were lower mean total and IgE serum antibody levels in lower exposure classes and a higher percentage with elevated antibody levels in high exposure classes (for T, x2 = 17.5, p = .0016; for IgE, x2 = 76.7, p less than .0001). In the new enrollee population, demographic variables of age, sex, date of hire, and smoking status were examined related to antibody levels. Only current or former smoking was related to elevated total antibody levels.

Antibodies↗

PubMedDate not supplied

Geometrical studies of the left ventricle utilizing biplane cinefluorography.

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Animals↗

PubMedDate not supplied

Instantaneous changes in the left ventricular lengths occurring in dogs during the cardiac cycle.

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Animals↗

PubMedDate not supplied

Composition of the subscribers in a rural prepair group practice plan.

To determine the degree to which enrollees of the Greater Marshfield Community Health Plan were representative of the community the plan was designed to serve, a telephone survey of 1,838 households in the 30-township area was undertaken. The response rate was 93%, and data were obtained from 1,718 households containing 5,260 persons. Of these, 484 households had at least one health plan member. Since the plan accepts only persons under age 65, analysis of the data was limited to those persons aged 64 and younger. Results indicate that enrollees showed good representation of demographic variables such as age, sex, and relationship to the household head when they were compared to the under 65 population of the area. When the enrollee's socioeconomic characteristics (education, income, and occupation) were studied, it was found that, although enrollees showed good representation for most categories they tended to underrepresent the under 65 area population in the lowest income and education classes, as well as in the semiskilled or unskilled occupations. The opposite was true for the upper income and educational classes. Data on location of residence indicated that a strong relationship existed between enrollment and proximity to Marshfield, where the major health care center is located. The use of health services was found to be positively related to membership, with enrollees overrepresented among those with recent hospital or physician contacts. The ability to obtain coverage through employment or by other means was found not to be related to membership. Satisfaction as expressed by participants was much higher in the prepaid program than among those with other forms of coverage.

Adolescent↗