Biomedical subjects

R J O'Brien

Publications and source records attributed to R J O'Brien.

75 records · Page 5Linked to original sources

PubMedDate not supplied

Respiratory status of surface coal miners in the United States.

The United States Public Health Service examined 1,438 surface coal miners to determine the prevalence of coal worker's pneumoconiosis (CWP), chronic bronchitis, and ventilatory impairment among them. Four percent (fifty-nine individuals) showed some roentgenographic evidence of pneumoconiosis, but only seven miners had films interpreted as CWP of category 2 or greater (according to the UICC/Cincinnati classification system). Moreover, most of the affected miners had worked in underground coal mines for prolonged periods. Significant decrements in pulmonary function to increasing exposure to surface mine dust were demonstrated only in the forced vital capacity of smokers. Increased prevalence of chronic bronchitis with increasing exposure was found in all smoking categories. However, significant airway obstruction was an uncommon finding (6.6%) in nonsmoking miners. Employment in surface mining was not likely to cause either the development of CWP or clinically significant respiratory impairment.

Adult↗

PubMedDate not supplied

Rifabutin (ansamycin LM 427): a new rifamycin-S derivative for the treatment of mycobacterial diseases.

Rifabutin (ansamycin LM 427), a semisynthetic spiropiperidyl derivative of rifamycin S, shows good in vitro activity against most mycobacterial species, including Mycobacterium avium complex. In animal models, the drug is more active against both Mycobacterium tuberculosis and Mycobacterium leprae than in rifampin, and studies indicate that rifabutin is active against some rifampin-resistant strains of both species. The drug has a long half-life (16 hr) in humans and a marked tissue tropism, with tissue levels five- to 10-fold higher than that in the serum. In animals rifabutin is no more toxic than rifampin. A large experience from the compassionate use of rifabutin for life-threatening mycobacterial infections in humans, most commonly disseminated M. avium complex disease in patients with AIDS, has also indicated relative drug safety. Although some data suggest that rifabutin is effective, firm conclusions about drug efficacy await results from controlled clinical trials.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Persistence of influenza A/New Jersey/76 (Hsw1N1) antibody one year after vaccination.

Serum HI and neuraminidase-inhibiting (NI) antibody measurements were made at 3, 32 and 50 weeks after inactivated influenza Hsw1N1 vaccination of 438 adults in 1976. Although the highest postvaccination geometric mean HI titers were observed in persons greater than or equal to 52 years of age, the rate of antibody decline was similar in adults of all ages. In 14 children who had a seroconversion following two doses of whole virus or split virus vaccine, the geometric mean HI antibody titer was lower after the second vaccine dose than the peak titer observed in adults, and the decrease in titer was also more rapid by 4 to 7 months. One year after influenza Hsw1N1 vaccination of adults, the prevalence of homologous HI antibody greater than or equal to 40 was 71% to 97%, whereas only two of the 14 children maintained similar titers at 5 to 7 months. Neuraminidase-inhibiting antibody titer formation occurred more frequently in those without prevaccination NI antibody, but the rate of decline was also greatest in this initially seronegative group. The rate of antibody decline at one year in the population with preexisting antibody was similar to that observed for HI antibody decline in a primed population. Heterologous influenza A/Victoria/3/75 (H3N2) HI antibody formation occurred in 22% of adults aged 25 to 51 after Hsw1N1 vaccination and in 12% of those over the age of 51, but the rate of heterologous antibody decline was more rapid than that observed for homologous antibody.

Adult↗