Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.     

Population-based epidemiology of human immunodeficiency virus infection in Western Australia. Western Australian AIDS Advisory Committee

A total of 328 cases of infection with human immunodeficiency virus (HIV) in Western Australia in 1983-1987 was studied with respect to demographic factors, the risk profile, the clinical progression of disease, the utilization of inpatient services and trends in incidence over time. The crude incidence rates were 8.8 cases/100,000 person-years in men and 0.4 cases/100,000 person-years in women. Age-specific rates peaked at 25 to 29 years of age in men. The risk of HIV infection was associated with metropolitan residence, low socioeconomic level, and two specific occupational groups. Homosexual and bisexual men constituted 86% of all cases; the incidence rate of HIV infection in such men was approximately 1000-times higher than was the incidence rate by apparent sexual transmission in heterosexual persons. However, the proportion of cases that occurred in women or that apparently was caused by heterosexual sexual transmission increased from zero in 1983-1984 to 7.5% and 5.4%, respectively, in 1987. After two years of follow-up, 71% of preclinical (category-C) patients had developed signs, symptoms or evidence of immune dysfunction, and 12% of those patients with lymphadenopathy or with other early clinical features of disease (category-B) had progressed to the acquired immunodeficiency syndrome (AIDS). At 21 months of follow-up, the survival rate with AIDS was 9%. Patients with AIDS utilized an average of 68.9 short-stay hospital bed-days per person-year, while category-B patients used 11.5 hospital bed-days per person-year. Notifications of HIV infection increased each year from 1983 to 1986, but fell by 22% in 1987. The latter may have been as a result of chance, a screening artefact or a real reduction in the incidence rate.     

Chlordiazepoxide alters intravenous cocaine self-administration in rats

This investigation was designed to examine the effects of benzodiazepines on intravenous cocaine self-administration in rats. Pretreatment with low doses of the benzodiazepine receptor agonist, chlordiazepoxide (0.3 to 1.0 mg/kg, IP), resulted in small but nonsignificant increases in drug intake with 0.5 mg/kg cocaine, while higher doses (10 mg/kg, IP) significantly decreased drug intake in all rats tested. The effects of chlordiazepoxide on self-administration were attenuated when the concentration of cocaine was increased to 1.0 mg/kg, suggesting that chlordiazepoxide was opposing rather than augmenting the pharmacological actions of cocaine. Pretreatment with the benzodiazepine receptor antagonist, Ro 15-1788 (1.0 to 10 mg/kg, IP), had no effect on self-administration, suggesting that the reinforcing properties of cocaine do not result from direct interactions with benzodiazepine receptors. The result of this investigation demonstrate that chlordiazepoxide alters intravenous cocaine self-administration in rats. Although additional research will be necessary to confirm these data, the results of this investigation suggest that chlordiazepoxide may decrease the reinforcing efficacy of cocaine through indirect actions on dopaminergic neuronal activity potentially mediated through GABAergic mechanisms via benzodiazepine receptor activation.     

Determinants of chronic bronchitis and lung dysfunction in Western Australian gold miners

The relation of chronic bronchitis and respiratory dysfunction to age, tobacco smoking, and occupational exposure to surface and underground mining operations were examined in a cross sectional survey of 1363 men employed in the Kalgoorlie mining industry in 1985. Overall, the prevalence of chronic bronchitis was 14%. Eleven per cent of the workers had obstructive lung disorder (FEV1/FVC less than 0.70) and 9% had restrictive lung disorder (FVC less than 0.80 of predicted for height and age). There was little change in the prevalence of chronic bronchitis from that observed in a survey of the same industry in 1961-2. Only 1% of the workers in 1985 had radiographic signs of silicosis compared with 22% in 1961-2. Age, smoking, and underground mining experience all exerted strong effects on the development of chronic bronchitis with or without associated respiratory function abnormalities. After control of confounding by age and smoking, it was estimated that compared with a lifetime non-miner, the odds ratio (OR) of chronic bronchitis was 1.8 (95% confidence interval, 1.0-3.3) for one to nine years underground mining gold, 2.5 (1.2-5.2) for 10-19 years, and 5.1 (2.4-10.9) for 20 or more years. Underground mining of minerals other than gold was also associated with chronic bronchitis (OR = 5.1; 95% CI, 1.1-25.0) whereas exclusive surface mining had only a small empirical effect (OR = 1.3; 95% CI, 0.6-2.5). It is estimated that the proportion of cases of chronic bronchitis in working underground miners due to occupational factors is 50%. The results support the existence of an industrial cause of chronic bronchitis, although caution must be exercised in generalising the results to miners with progressive and sever respiratory impairment.     

A cluster of cases of streptococcal necrotizing fasciitis in Gloucestershire.

We describe the first cluster of cases of necrotizing fasciitis (NF) in this century in the United Kingdom (UK). Between 1 January and 30 June 1994 there were six cases (five confirmed, one probable) of Streptococcus pyogenes NF in west Gloucestershire, population 320,000. Two cases died. The first two patients probably acquired their infections during the course of elective surgery performed in the same operating theatre, possibly from a nasopharyngeal carrier amongst the theatre staff. The remaining infections were community-acquired. Of 5 S. pyogenes isolates there were 2 M1 strains, 1 M3, 1 M5 and 1 M non-typeable strain. S. pyogenes NF had not been recorded in west Gloucestershire in the preceding 10 years and the incidence of S. pyogenes bacteraemia in England and Wales had not risen in the past 5 years. The two presumably theatre-acquired infections raised several issues. The need for detailed bacteriological investigation of all cases of post-surgical NF was confirmed. Clusters of S. pyogenes infection following surgery should be managed by closure of the operating theatre until all staff have been screened for carriage. Closure of an operating theatre and screening of staff following a sporadic case is probably not justified because of the infrequency of surgical cross-infection with S. pyogenes. Regular, routine screening of theatre staff is neither practical nor necessary.