Epidemiological-environmental study of lead acid battery workers. II. Acute effects of sulfuric acid on the respiratory system

Two hundred and twenty-five (225) workers in five lead acid battery plants were administered a questionnaire containing work-related symptoms, underwent spirometry, and had personal samples for H2SO4 taken over the shift. Most personal samples were less than 1 mg/m3 H2SO4. Mass median aerodynamic diameter of H2SO4 from area samples in the formation areas was 2.6-10 micron. Workers with a higher exposure to acid did not have an increased rate of acute work-related symptoms. Changes in pulmonary function over the shift were not related to levels of airborne lead or airborne acid, sex, age, or smoking status. In acclimated workers, there is no evidence of acute symptoms or reductions in pulmonary function over the shift at concentrations less than 1 mg/m3.     

A comparison of two methods for the computer analysis of arterial blood pressure waveforms

Two different methods, one analogue and one digital, for the analysis of the arterial blood pressure waveform are described and compared. Little difference was found in the systolic and diastolic pressures determined by the two methods.     

New assessment of the prognostic significance of histopathology in Hodgkin's disease for laparotomy-negative stage I and stage II patients.

This paper describes preliminary radiotherapy results in 90 patients with Stage I and II Hodgkin's disease who were evaluated by laparotomy, including splenectomy, and liver and bone marrow biopsies. As a result of selection by laparotomy, the estimated five-year survival rate for these patients was 96%. No statistically significant differences were detected in the disease-free survival for patients with mixed cellularity, nodular sclerosis, and lymphocytic predominance disease. Since only one patient with lymphocytic depletion was in this series, no statement can be made regarding this rare histopathology. Patterns of new disease differed for Stage I and II patients. The major difference was that patients with nodular sclerosing Stage II presentations involving the mediastinum were at considerable risk of developing subsequent disease in the pulmonary parenchyma or the pleura. This finding, together with the demonstration that a histologic diagnosis of mixed cellularity did not carry an inferior prognosis, indicates the need for reassessment of the appropriateness of applying treatment programs based on results of lymphangiographically staged patients to Stage I and II patients evaluated by laparotomy.     

The role of chromosome 15 in murine leukemogenesis. I. Contrasting behavior of the tumor vs. normal parent-derived chromosomes no. 15 in somatic hybrids of varying tumorigenicity

G-banding analysis was carried out on a series of hybrids derived from the fusion of a chromosome 15-trisomic murine T-cell leukemia of AKR origin and normal diploid fibroblasts or lymphocytes of the CBT6T6 strain. Due to the 14; 15 translocation involved in the generation of the T6 marker, the chromosomes No. 15 and 14 derived from the normal and the tumor parent can be distinguished cytogenetically. Highly tumorigenic, in vitro maintained hybrids, and high-tumorigenic segregants of originally low-tumorigenic in vitro hybrids, selected by in vivo passage, showed a similar cytogenetic pattern. It was characterized by the amplification of the tumor-derived chromosomes No. 15 from the expected 3 to 5.5 ± 0.2 copies and a concomitant decrease of the normal derived T(14;15)6 from 2 copies to 0.9 ± 0.2. All other autosomes except No. 14 showed only minor random variations, around the expected number of 4 copies. The tumor-derived chromosome 14 was amplified from the expected 2 to 3 copies. The lowtumorigenic hybrids showed the opposite pattern with a decrease in the number of the tumor-derived 15 chromosome from 3 to 2.6 ± 0.1 and the maintenance of the two normal parent derived T(14;15)6 chromosomes. These findings suggest the existence of a qualitative difference between the 15 chromosomes derived from the tumor vs. the normal parent, due to mutation or proviral DNA insertion in the tumor-derived homologue. Amplification of the changed locus and a decrease in the dosage of its normal counterpart appear to favor tumorigenicity.     

Age and sex influence on pulmonary hypertension of chronic hypoxia and on recovery

To study the influence of age and sex on the hemodynamic and structural response of the pulmonary vascular bed to chronic hypobaric hypoxia, "infant" Sprague-Dawley rats from 8 days old and "adult" rats from 9 wk old, each group including both sexes, were exposed to half atmospheric pressure for 1 mo and then allowed to recover in room air for up to 3 mo. During hypoxic exposure, pulmonary artery hypertension (Ppa) developed in all groups. The level of Ppa was similar in both male and female infant and in male adult rats but was significantly lower (P < 0.01) in the female adult rats. After recovery in room air, only partial regression of Ppa had occurred in all groups (P < 0.001). In male and female adult rats, recovery values were similar but infant rats had more residual Ppa than adults (P < 0.001). The structural changes that developed during hypoxia, especially the abnormal presence of muscle in small and peripheral intra-acinar arteries, were more severe in male adult rats compared with female adults (P < 0.01) and in infants of both sexes compared with male adults (P < 0.01). After recovery, residual structural changes were present in all rat groups but were most severe in the infants (P < 0.01).