Prevalence of primary glaucoma in an urban south Indian population.

Glaucoma is fast emerging as a major cause of blindness in India. In order to estimate the prevalence of primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) in an urban South Indian population, we examined 972 individuals aged 30-60 years, chosen using a cluster sampling technique from 12 census blocks of Vellore town. They underwent a complete ocular examination, including applanation tonometry and gonioscopy, at the Medical College Hospital. Characteristic field defects on automated perimetry was a diagnostic requisite for POAG. Prevalence (95% CI) of POAG, PACG, and ocular hypertension were 4.1 (0.08-8.1), 43.2 (30.14-56.3), and 30.8 (19.8-41.9) per 1,000, respectively. All the PACG cases detected were of the chronic type. Hitherto unavailable community-based information on primary glaucoma in our study population indicates that PACG is about five times as common as POAG.

Inhibition of post-ischemic reperfusion injury of the kidney by diamine oxidase.

To elucidate the role of histamine in the pathogenesis of post-ischemic reperfusion injury of tissues, the effect of diamine oxidase (DAO) was studied on the changes in renal functions induced by 30 min occlusion followed by reperfusion of the renal vessels of unilaterally nephrectomized rats. Kinetic analysis using radiolabeled albumin revealed that vascular permeability of the kidney increased markedly after reperfusion. Although the intensity of neutrophil-dependent chemiluminescence of the blood remained unchanged during the occlusion, it increased significantly after reperfusion. Histological examination revealed a marked degeneration of glomeruli and proximal tubules in the reperfused kidney. Transtubular transport of phenolsulfophthalein (PSP) decreased markedly after reperfusion with concomitant increase in plasma levels of creatinine. Intravenously administered DAO markedly inhibited the reperfusion-induced increase in vascular permeability, preserved the structure of the kidney and normalized the rate of clearance of PSP and creatinine. Combined use of diphenylhydramine and ranitidine also inhibited the reperfusion injury of the kidney. These results suggested that histamine and its receptors might play critical roles in post-ischemic reperfusion injury of the kidney.

Acute and subacute inhalation toxicity of dichlorosilane in male ICR mice.

Using male ICR mice, the LC50 and acute and subacute inhalation toxicity of dichlorosilane (SiH2Cl2, DCS) and the fate of DCS released into the air were investigated. DCS resolved and minute particles including silicon and chloride were observed, when DCS was released into the air. Most particles were under 1 micron in diameter. The LC50 of DCS at 4-h exposure was 144 ppm (nominal concentration). In the acute inhalation study, ten mice in each group were exposed to 64 ppm (nominal concentration) DCS for 1, 2, 4 or 8 h. Body weight loss, wheezing and piloerection were observed in mice exposed for 2 h or more. Histopathologically, injury to the nasal mucosa and trachea were observed in all exposed mice. Mice exposed to 32 ppm (nominal concentration) DCS for 2 or 4 weeks also exhibited depression of body weight gain, wheezing and piloerection. Squamous metaplasia of the nasal mucosa and tracheal epithelium was observed in both 2- and 4-week exposure groups. Exposure to DCS was irritant or corrosive to the respiratory tract with both acute and subacute inhalation. Apart from silane (SiH4), toxic effects of DCS seem to be characterized by chloride compounds derived from DCS.

A basic framework of working environment control for occupational health in Japan.

This review deals with three aspects of occupational health practices in Japan, i.e., working environment control, work practice management and health care, with an emphasis upon working environment control. Control of chemical hazards and physical agents in working environment is of prime importance to prevent workers from health impairments due to the hazardous agents. The Japanese legislative system for control of hazardous agents in working environment is characterized by "workplace control", and it is different from "control of personal exposure based on exposure limits of hazardous substances". Hazardousness of working environment contaminated with a toxic substance is assessed by screening air sampling at workplace designated as Measurement A and by fixed point air sampling designated as Measurement B. Working environment was categorized as Control Class I, II or III with both geometric mean and geometric standard deviation of concentrations of the hazardous agent with reference to an "administrative control level". The nationwide survey of air concentrations of dust and lead at workplaces revealed that the present Japanese system of working environment control had been effective to reduce the number of the harmful workplaces evaluated as Control Class III, the worst category, in the decade of 1984-1993 throughout Japan.

Inhibition of post-ischemic reperfusion injury of the small intestine by diamine oxidase.

To elucidate the role of diamines in the pathogenesis of post-ischemic reperfusion-induced tissue injury, the effect of diamine oxidase was studied in the rat whose superior mesenteric artery was occluded for 15 min followed by 30 min reperfusion. Kinetic analysis using radiolabeled albumin revealed that the mucosal permeability of the reperfused small intestine increased significantly. Histological examination of the reperfused intestine revealed a marked degeneration of its mucosal layer. Intravenous administration of diamine oxidase inhibited the reperfusion-induced increase in mucosal permeability of the intestine almost completely and preserved the structure of the small intestine. H1-antagonist chlorphenilamine and H2-antagonist famotidine also inhibited the reperfusion injury of the small intestine. These and other results suggested that extracellular diamines might play critical roles in post-ischemic reperfusion-induced injury of the small intestine.

Inhibition of posthemorrhagic transfusion-induced gastric injury by a long-acting superoxide dismutase derivative.

Although oxygen-free radicals have been postulated to play an important role in the pathogenesis of gastric mucosal injury induced by posthemorrhagic blood transfusion, direct evidence supporting this hypothesis is lacking. Superoxide dismutase (SOD) has been shown to inhibit oxygen toxicity in vitro in various types of cell injury. However, in some cases, oxidative tissue injury cannot be decreased efficiency predominantly due to its rapid elimination by renal glomerular filtration. To overcome such frustrating situations, we have synthesized a SOD derivative that circulates bound to albumin with a half-life of 6 hr. When blood was withdrawn from the rat (22 ml/kg) for 30 min followed by transfusion of the extracted blood, marked gastric mucosal lesions occurred within 30 min after transfusion. Intravenously injected SOD derivative markedly decreased gastric mucosal injury. Kinetic analysis using 125I-labeled albumin revealed that the vascular permeability of the stomach increased significantly after transfusion by a SOD derivative inhibitable mechanism. Thus, superoxide radical and/or its metabolite(s) play a critical role in the pathogenesis of posthemorrhagic transfusion-induced gastric injury.

[Breast cancer associated with pregnancy].

Two cases of breast cancer associated with pregnancy were reported and the immunological assessment was performed in the second case. Case 1: A 36 year-old woman in the first trimester of pregnancy and having a large axillary mass and breast lump was admitted. She was diagnosed as having Stage IIIb breast cancer. After interruption of pregnancy, she received an extended radical mastectomy and radiotherapy. However, she died nine months after surgery for brain and liver metastases. Case 2: A 30 year-old woman in her second trimester of pregnancy was admitted for a large breast mass. She was diagnosed as having Stage IIIa breast cancer. Interruption of pregnancy was again necessary to perform surgery followed by chemotherapy. After an extended radical mastectomy she was placed on a combination chemotherapy regimen with cyclophosphamide, adriamycin and 5-FU. In both cases tumors began to develop rapidly at pregnancy. Immunological studies in Case 2 showed a depression of T-lymphocyte function and NK cell activity. Our study suggests that the depression of cell-mediated immunity during pregnancy may promote tumor growth.