Efficacy of reflective insulation in reducing heat stress on dairy calves housed in polyethylene calf hutches.

The objective of this study was to determine the ability of radiant insulation hutch covers to moderate the effect of ambient temperature and radiant energy on calves housed in polyethylene hutches. The insulation had a double layer of polyethylene bubble film laminated between a layer of aluminum foil and white polyethylene (reflectance = 95%, R value (ft(2) · °F ·h/Btu) = 2.7). In each of two experiments (exp.), hutches were either uninsulated (control) or covered with reflective insulation across the top and sides of the hutch leaving the front, back, and pen exposed. Each hutch had a 1.2 × 1.8-m attached outdoor wire pen. In both exp., rate of increase of interior hutch temperature relative to ambient temperature was lower in insulated hutches (P < 0.001) indicating they were warmer at low THI and cooler at high THI. In exp. 1, increase in respiration rate and ear canal temperature of the calves, relative to THI, were moderated in insulated hutches (P < 0.001). In Exp. 2, respiration rate was not affected by treatment (P = 0.50), but increased with increasing THI (P < 0.001). Mean ADG did not differ among treatments in either exp. (P > 0.21). Insulating calf hutches with reflective insulation moderated hutch microclimate, and improved calf comfort, but did not translate to improvements in economically relevant variables such as ADG.

Maximal heart rate and treadmill performance of healthy women in relation to age.

Maximal treadmill exercise heart rate, work capacity and electrocardiographic response were studied in 95 asymptomatic, predominantly sedentary women between the ages of 19 and 69 years. Average maximal heart rate (MHR) was found inversely related to age, such that MHR = 216 -0.88 (years of age) +/- 10 beats/min (X +/- 1 SD). Treadmill exercise endurance was 7.64 min +/- 1.99. The reduction of treadmill endurance with advancing age was not statistically significant. Asymptomatic ST-segment depression occurred in 6% of subjects. In 5% the ST segment sloped upward, and in 1% it was flat. Mean age of women with ST depression was 52 years, compared with 39 years mean age of all subjects. Premature beats during exercise were found in 20 of 95 subjects, and were not related to age. Graded exercise testing of women employing target heart rates should use heart rate tablets developed especially for women. These tables do not require correction for athletically trained for sedentary life-style.

Acute percutaneous transluminal coronary angioplasty complicated by embolism to a coronary artery remote from the site of infarction.

Percutaneous transluminal coronary angioplasty has emerged as a mode of treatment in patients with both chronic and acute coronary syndromes. Among the recognized complications of coronary angioplasty is coronary embolism. This case report describes a case of acute anterior myocardial infarction which was treated with angioplasty of the left anterior descending coronary artery. Postdilation angiography revealed obstruction of the posterior descending artery (in a left dominant system). The use of thrombolytic therapy previous to angioplasty is briefly discussed.

Pap tests of rural black women.

Cervical cancer is an important cause of cancer mortality in black women. Pap tests may prevent such deaths, but poor, rural black women are relatively less likely than others to be screened. In order to understand why that is so, the authors surveyed 149 women in three rural North Carolina counties. Thirty-three percent of the women interviewed had not had a Pap test in the preceding three years. Variables independently associated with not having a recent Pap test included: having no identifiable source of medical care; having more than one source of gynecologic care; having an internist provide gynecologic care; and perceiving psychological barriers to Pap tests and pelvic examinations. Income, educational level, and health insurance status were not associated with having a recent Pap test. Although access to care remains a problem for some, better use should be made of the medical care encounters available.

Accuracy of women's self-report of their last Pap smear.

We compared interview data and physician records on when women last had a Pap smear in a sample of 98 rural Black women. We found 20 per cent of women could not accurately report on whether a Pap smear had been done within three years (sensitivity = 0.95, specificity = 0.47). Source of gynecological care and perceived barriers to obtaining a Pap smear but not education were associated with inaccurate reports. Self-report may be a misleading measure of Pap smear screening in comparable groups of women.

Field evaluation of enzyme-linked immunosorbent assay for the serodiagnosis of tuberculosis.

An enzyme-linked immunosorbent assay (ELISA) was evaluated as a serodiagnostic test for active tuberculosis in La Paz, Bolivia. ELISA was compared with sputum smear in 277 persons presenting to the Instituto de Torax and was used for screening in 1,458 military personnel. The test was performed under field conditions on 4-microliter samples of capillary blood obtained by finger prick. ELISA was found to have a sensitivity of 69% and a specificity of 88%. Sputum smear had a sensitivity of 79% and a specificity of 100%. ELISA was found to have undiminished sensitivity and specificity in patients who were sputum-negative, and the two tests could be combined to achieve a sensitivity of 92% and specificity of 88%. Positive and negative predictive values were highest for populations with tuberculosis prevalences in the range of that seen among patients presenting to the Instituto de Torax in Bolivia, but ELISA also led to the diagnosis of tuberculosis in 5 of 1,458 soldiers tested in the screening program.

Modulation of human neutrophil effector functions by monoclonal antibodies against surface membrane molecules of 94,000 and 180,000 molecular weight.

Function-related antigens on the neutrophil (PMN) surface were identified using two newly developed PMN-specific mouse monoclonal antibodies. These IgG antibodies, designated Ab 1-14 and Ab 1-15, were selected for detailed study after initial testing revealed their significant inhibition of PMN superoxide generation in response to N-formyl-Met-Leu-Phe (FMLP) (64% for 1-14 and 64% for 1-15; P less than .05). In further experiments, Ab 1-14 augmented PMN adhesion (by 111%; P less than .01) and degranulation (by 52%; P less than .05) in response to FMLP, while Ab 1-15 inhibited these responses by 42% and 29%, respectively (P less than .05). Ab 1-14 reduced PMN chemotaxis in response to FMLP by 37% (P less than .02), and unlike Ab 1-15, Ab 1-14 significantly reduced unstimulated PMN binding of complement-coated sheep red blood cells. Ab 1-14 and Ab 1-15 significantly reduced PMN superoxide production in response to phorbol myristate acetate (PMA) (14% and 23%, respectively; P less than .05). Whereas 1-14 was found to increase PMA-induced cell degranulation significantly (175%), Ab 1-15 did not alter degranulation response to PMA. Immunoprecipitation showed that Ab 1-14 and Ab 1-15 recognized respective surface antigens of 94,000 mol wt and 130,000 to 180,000 mol wt. Our findings suggest that the surface molecules identified by these two monoclonal antibodies play a significant role in neutrophil activation by both FMLP and PMA.