Silicosis in a grey iron foundry. The persistence of an ancient disease

An industrial hygiene and medical survey was conducted in an iron foundry to study the occurrence of silicosis. Breathing zone exposures to respirable crystalline silica had been very high in 1977 [1 045 micrograms/m3 (geometric mean) for coremakers and 198 micrograms/m3 for fettlers]; exposures in 1980 and 1982 were substantially lower. A radiographic evaluation of 188 workers revealed silicosis in 18 (9.6%). Eight had category 1 profusion of small rounded pulmonary lesions (by the 1980 classification of the International Labour Office); two had category 2; and eight had category 3. Two had progressive massive fibrosis. Four workers without silicosis in 1977 had developed lesions by 1980. The prevalence increased from 1.5% among workers employed less than 20 years to 53% among longer term workers. No association was found between the prevalence of silicosis and cigarette smoking. Chronic cough was more common in workers with heavy current dust exposure than in those with light exposure, more common in smokers than in nonsmokers, and more common in silicotics than in nonsilicotics. A multiplicative interaction existed between dust exposure and smoking in the etiology of cough. Silicosis continues to exist in American foundries. Cigarette smoking does not contribute to the causation of silicosis, but it aggravates the attendant respiratory symptoms.     

Causation, therapy and complications of treating mandibular fractures - a retrospective analysis of 10 years]

BACKGROUND: Fractures of the mandible are a common form of facial injury. The aetiological factors associated with mandibular fractures and the trends in these factors over a 10-year period are reported. METHODS: A retrospective survey was carried out of 724 patients presenting with a fracture of the mandible over the 10-year-period 1994-2003. Patients; records were reviewed and analyzed according to age, sex, cause of injury, anatomic site of fracture, treatment and postoperative complications. RESULTS: Over the 10-year-period the rate of mandibular fractures remained constant (mean 40,7%). There were no changes in the age group (mean 33,3 years) or in the higher prevalence in male (male-female-ratio 2,3 : 1). The major causes of fractures were assaults (38,6%) and accidental fall (27,3%). The most common fracture site was the condylar region (47,0%) followed by the angle (29,4%). Most fractures were treated by closed reduction until 2002, thereafter surgical treatment increased noticeable. The complication rate was 8,9% and the most common complications were hardware exposure and infection. CONCLUSION: Fractures of the mandible are a prevalent form of facial injury. Aetiological factors show no significant change over the 10-year-period. Complication-rate is low and will support the tendency towards surgical treatment.     

Early cardiovascular changes with ibopamine: evidence for a biphasic haemodynamic action.

1. The haemodynamic effects of ibopamine, an oral dopamine derivative, were studied in eight patients with left ventricular dysfunction using invasive catheterisation techniques. 2. An early rise was seen in the mean right atrial pressure (P less than 0.05), the mean capillary wedge pressure (P less than 0.01) and the mean pulmonary arterial pressure (P less than 0.001) which occurred at 15 min and persisted for 30 min. 3. A second, later, positive chronotropic effect was seen as an increase in the heart rate (P less than 0.05) at 45 min with an increased cardiac output (P less than 0.05) persisting above baseline values at 1 h, but with no change in stroke volume. 4. These results support a biphasic mode of action for ibopamine which may be explained by a time phase difference in alpha- and beta-adrenoceptor stimulatory effects.     

Is the Cotrel-Dubousset really universal in the surgical treatment of idiopathic scoliosis?

We reviewed the results of 22 cases of Cotrel-Dubousset (C-D) instrumentation, 16 cases of anterior approach, and 200 cases of posterior approach by Harrington instrumentation and modifications of Harrington procedure. Posterior spinal fusion and instrumentation by C-D gives better correction and stabilization in thoracic and balanced double major curves. We no longer use the Harrington procedure and its modification. In lumbar and short thoracolumbar curves, VDS is still preferred. In some double major curves combined procedures, VDS and C-D are used to obtain more correction with a shorter fusion area.     

Expressed-emotion development and course of schizophrenic illness: considerations based on results of a CFI replication

This study examines the correlation between development of expressed emotion (EE) in relatives and course of illness of 99 DSM-III schizophrenic patients. Patients whose relatives were high EE at baseline and at the 2nd CFI approximately 20 months later had a poor prognosis at the very outset of the study and an unfavourable course of illness. They had a higher rehospitalisation rate, more symptoms, lower psychosocial assessment, and a poorer 2-year and even 8-year outcome. Patients from families with a fluctuating EE or a consistently low EE had better courses. Expessed emotion is therefore a valid predictor not only of symptomatic relapses, but also of other important aspects of schizophrenia. The connection between EE index and course of illness seerns not to be simply reactive or causal, but complex and non-uniform.     

Intermittent obstruction of a Bjork-Shiley mitral valve prosthesis--an unusual diagnosis aided by Doppler ultrasound

Obstruction of a Bjork-Shiley mitral valve prosthesis occurred in a 41 year old woman due to pannus tissue growing over the valve and impairing disc opening. The unusual intermittent nature of the obstruction was clearly demonstrated by Doppler ultrasound. The pannus was excised and the valve prosthesis replaced successfully with a Carpentier-Edwards xenograft.     

Benzene and leukemia. An epidemiologic risk assessment

To assess quantitatively the association between benzene exposure and leukemia, we examined the mortality rate of a cohort with occupational exposure to benzene. Cumulative exposure for each cohort member was estimated from historical air-sampling data and, when no sampling data existed, from interpolation on the basis of existing data. The overall standardized mortality ratio (a measure of relative risk multiplied by 100) for leukemia was 337 (95 percent confidence interval, 154 to 641), and that for multiple myeloma was 409 (95 percent confidence interval, 110 to 1047). With stratification according to levels of cumulative exposure, the standardized mortality ratios for leukemia increased from 109 to 322, 1186, and 6637 with increases in cumulative benzene exposure from less than 40 parts per million-years (ppm-years), to 40 to 199, 200 to 399, and 400 or more, respectively. A cumulative benzene exposure of 400 ppm-years is equivalent to a mean annual exposure of 10 ppm over a 40-year working lifetime; 10 ppm is the currently enforceable standard in the United States for occupational exposure to benzene. To examine the shape of the exposure-response relation, we performed a conditional logistic-regression analysis, in which 10 controls were matched to each cohort member with leukemia. From this model, it can be calculated that protection from benzene-induced leukemia would increase exponentially with any reduction in the permissible exposure limit.     

Induced luteolysis in the primate: rapid loss of luteinizing hormone receptors

The molecular mechanisms involved in luteolysis are still unclear in the primate. This study aimed to investigate the effect of induced luteolysis on the ovarian luteinizing hormone (LH) receptor and the steroidogenic enzyme, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) in the marmoset monkey. Luteolysis was induced in the mid-luteal phase either directly by systemic prostaglandin F2alpha (PGF2alpha), or indirectly by LH withdrawal using systemic gonadotrophin releasing hormone antagonist (GnRHant) treatment. The LH receptor was studied by isotopic mRNA in-situ hybridization and in-situ ligand binding and 3beta-HSD expression was studied using isotopic mRNA in-situ hybridization and immunohistochemistry. Induced luteolysis was associated with a reduction in the expression of LH receptor (P < 0.0001) and 3beta-HSD mRNA, closely followed by a reduction in the LH receptor (P < 0.05) and 3beta-HSD protein concentrations within 24 h. There were no differences in the findings whether luteolysis was induced with PGF2alpha or GnRHant. This study shows that disparate mechanisms to induce luteolysis in the primate result in an identical rapid loss of the LH receptor and 3beta-HSD. In conclusion, induced luteolysis leads to rapid loss of the steroidogenic pathway in luteal cells.