SELF-REPORTED HEARING LOSS AMONG WORKERS EXPOSED TO INDUSTRIAL NOISE. ANALYSIS OF U.S. SURVEILLANCE DATA WITH REFERENCE TO THE AUSTRALIAN ENVIRONMENT

Aging and noise are the two main causes of hearing loss. To estimate the extent to which hearing loss is due to noise and is therefore preventable, an analysis was undertaken, using U.S. surveillance data, of the prevalence of hearing loss in workers in industries categorised according to the percentages of the workforce exposed to noise levels of 85 dBA or more. It was estimated that 13 per cent of the U.S. workforce was exposed to these noise levels, and that occupational noise exposure accounted for 20 per cent of self-reported hearing loss in the male workforce. Applying the industry-specific exposures to Australia, it is estimated that some 657,000 workers are exposed to noise levels of 85 dBA or more in this country. Australian Bureau of Statistics data indicate that constant noise accounts for 38 per cent of self-reported hearing loss in Australian adult males (although this figure would include hearing loss due to non-occupational noise). Data from both countries indicate that the prevalence of noise-induced hearing loss in females is negligible.     

Quantitative structure-activity relationships in MAO-inhibitory 2-phenylcyclopropylamines: Insights into the topography of MAO-A and MAO-B

Ten (E)-and (Z)-isomers of 2-phenylcyclopropylamine (PCA), 1-Me-PCA, 2-Me-PCA, N-Me-PCA, and N, N-diMe-PCA and fifteeno ⁻, m⁻, p⁻ isomers of (E)-PCA with substituents of Me, Cl, F, OMe, OH were synthesized in this laboratory and tested for the inhibition of rat brain mitochondrial MAO-A and MAO-B. The effects of substituents, their positions, and stereochemistry on the inhibition were assessed for the compounds with substituents at cyclopropyl and amino groups and QSAR analyses were performed using the potency data of ring-substituted compounds. The best correlated QSAR equations are as follows: pI₅₀=0.804 Π² Blo−1.069 Blm+0.334 Lp−1.709 HDp+7.897 (r=0.945, s=0.211, F=16.691, p=0.000) for the inhibition of MAO-A; pI₅₀=1.815 π-0.825 Π² R+0.900 Es²+0.869 Es³+0.796 Es⁴−0.992 HDp+0.562 HAo+3.893 (r=0.982, s=0.178, F=23.351, p=0.000) for the inhibition of MAO-B. Based on the potency difference between stereoisomers of cyclopropylamine-modified compounds and on QSAR results, it is proposed that the active sites of MAO-A are composed of one deep hydrophobic cavity near para position, two hydrophobic cavities interacting with Me group, a hydrophobic area accomodating phenyl and cyclopropyl backbone, steric boundaries, a hydrogen-acceptor site near para position, and an amino group binding site and that in addition to the same two hydrophobic cavities, hydrophobic area, steric boundaries, hydrogen-acceptor site, and amino group binding site, another steric boundary near para position and a hydrogen donating site near ortho position constitute active sites of MAO-B.     

Neuroendocrine effects in printing workers exposed to toluene.

The effect of exposure to toluene on plasma concentrations of testosterone, prolactin, luteinising (LH) and follicle stimulating (FSH) hormones was investigated in 47 rotogravure printers (time weighted average air toluene below 80 ppm; blood toluene concentration post-shift 0.19-7.99 mumol/l) and compared with a reference group. Increasing exposure concentrations of toluene (concentrations less than 5 to greater than 45 ppm) were significantly associated with decreasing plasma concentrations of LH (tau = -0.21, p = 0.003) and testosterone (tau = -0.25, p = 0.02). No correlation was found between cumulative exposure (ppm x years) and plasma hormone concentrations. The associations with exposure were present even when nine printers with heavy alcohol consumption were excluded. The study indicates an effect of low toluene exposure on the hypothalamus-pituitary axis, with a secondary decrease in testosterone secretion.     

Hepatotoxicity in HIV-infected children and adolescents on antiretroviral therapy.

CONTEXT AND OBJECTIVE: Adverse drug reactions are a significant problem in patients on antiretroviral therapy (ART). We determined liver enzyme elevation frequencies in HIV-infected children and adolescents receiving ART, and their association with risk factors. DESIGN AND SETTING: Cross-sectional study, at the Pediatrics Immunodeficiency Division, University Hospital, Universidade Estadual de Campinas. METHODS: Medical records of 152 children and adolescents (54.6% male; median age 7.48 years) were analyzed, with a mean of 2.6 liver enzyme determinations per patient. Clinically, patients were classified in categories N (6), A (29), B (78) and C (39). Serum levels of aspartate aminotransferase and alanine aminotransferase were evaluated. Hepatotoxicity was scored as grade 1 (1.1-4.9 times upper limit of normality, ULN), grade 2 (5.0-9.9 times ULN), grade 3 (10.0-15.0 times ULN) and grade 4 (> 15.0 times ULN). To assess hepatotoxicity risk factors, odds ratios (OR) and adjusted odds ratios (aOR) for age, gender, TCD4+ cell count, viral load and medication usage were calculated. RESULTS: We observed grade 1 hepatotoxicity in 19.7 % (30/152) patients. No cases of grade 2, 3 or 4 were detected. There was a significant association between hepatotoxicity and use of sulfonamides (OR, 3.61; 95% confidence interval (CI), 1.50-8.70; aOR, 3.58; 95% CI, 1.44-8.85) and antituberculous agents (OR, 9.23; 95% CI, 1.60-53.08; aOR, 9.05; 95% CI, 1.48-55.25). No toxicity was associated with ART. CONCLUSIONS: One fifth of patients experienced mild hepatotoxicity, attributed to antituberculous agents and sulfonamides. Our results suggest that ART was well tolerated.     

Diagnoses of alcohol abuse and other neuropsychiatric disorders among house painters compared with house carpenters.

The incidence of alcoholism and the incidence of other neuropsychiatric diagnoses were compared between the 767 house painters and the 1212 house carpenters, born in 1925 or later, who were members of the Stockholm branches of their respective trade unions in 1965 and who had been members for at least 10 years before 1970. Four different outcome registers were used: (1) the alcohol crime register, which contained all persons who had broken any law regulating the handling and consumption of alcohol (follow up period 1972-6). (2) The register of diagnoses at early retirement (follow up period 1971-84). (3) The register of diagnoses at discharge from inpatient psychiatric care (follow up period 1968-83). (4) The register of causes of death (follow up period 1965-86). Exposures to solvents and consumption of alcohol were evaluated by interviews with samples of the cohorts. A high average cumulative exposure to solvents was found among the painters. The mean consumption of alcohol was similar in the two cohorts. The incidence of diagnoses of neuropsychiatric disorders was higher in painters than in carpenters in all registers. Alcoholism was the most common neuropsychiatric disorder diagnosed and showed the highest relative risk. The excess of alcoholism among the painters was, however, due singularly to painters who had several registrations in the alcohol crime register or diagnoses of alcoholism in multiple registers. Thus the study implies that excessive alcohol consumption or severe damage due to alcohol, or both, but not less severe problems, were more common in painters than in carpenters. This suggests an interaction between exposure to solvents and intake of alcohol causing an increase in diagnosis of alcoholism among painters.     

抗凝血酶Ⅲ测定在评价肝脏功能中的应用

测定110例肝病的抗凝血酶Ⅲ(AT-Ⅲ)活性,62例低于正常(56.4％),均值为60.1±38.2％。50例正常对照为100.0±26.7％。重症肝炎、慢性活动性肝炎及失代偿期肝硬化活性显著下降,均值分别为12.9±13.0％、51.0±34.6％、43.3±29.6％.AT-Ⅲ活性在评价肝脏功能方面较凝血酶原时间敏感,具有一定的实用意义。     

Thrombin activatable fibrinolysis inhibitor and hemostatic changes in patients with type I diabetes mellitus with and without microvascular complications.

We investigated thrombin activatable fibrinolysis inhibitor (TAFI) and its influence on fibrinolysis by measuring pro-TAFI activity and total TAFI antigen in 38 patients with type I diabetes mellitus (18 with and 20 without microvascular complications), as well as in 20 healthy controls. The pro-TAFI levels in the two groups of patients did not differ from those in the control group. Total TAFI antigen [i.e. pro-TAFI, TAFI and inactive carboxypeptidase U (TAFIi)] tended to decrease in both the patient groups (59.7 +/- 7.2 and 73.4 +/- 8.9% with and without microvascular complications, respectively) compared with controls (91.9 +/- 12.2%) (P = 0.12). We also assessed the overall hemostatic potential (OHP) in plasma, the clot lysis time and the overall fibrinolytic potential. The OHP was significantly higher in patients with complications compared with controls (8.9 +/- 0.9 versus 6.7 +/- 0.4; P < 0.05) and also higher in the diabetics without complications (7.8 +/- 0.6), although the latter difference did not reach statistical significance. Levels of clot lysis time and overall fibrinolytic potential were similar in the two groups of patients and the controls. The increased OHP in plasma from diabetic patients with microvascular complications indicates an imbalance of the hemostatic system towards a prothrombotic state. No signs of impaired fibrinolysis were observed in patients with diabetes. Using the OHP method for estimation of overall hemostasis, it seems that TAFI does not influence either fibrinolysis or the increased thrombotic potential observed in patients with type I diabetes mellitus.     

选择性靶动脉栓塞在骶骨肿瘤切除术中的价值

目的 探讨和评估选择性靶动脉栓塞骶骨肿瘤后对外科切除肿瘤的价值和方法。方法 运用Seldinger技术，对9例骶骨肿瘤患者进行肿瘤供血动脉及肿瘤内血管全部彻底栓塞，栓塞材料应用明胶海绵，栓塞后1周内行手术切除术。结果 彻底的术前栓塞手术中失血量明显减少，9例骶骨肿瘤均得到彻底切除，平均失血量为1090ml。术后平均随访15个月，未见肿瘤局部复发。结论 骶骨肿瘤切除术前选择性靶动脉栓塞可有效减少术中出血，有利于肿瘤的彻底切除，为顺利切除骶骨肿瘤提供了有价值的方法。