ABSTRACT
To clarify the relation of essential metals to cadmium (Cd) toxicity, we evaluated metallothionein expression and analyzed the subcellular distribution of essential metals using in-air micro-Particle-Induced X-ray Emission (PIXE). Four mice were dosed orally with 100 mg/L of Cd in drinking water for 1.5 or 2 years. Frozen samples of organs were used for micro-PIXE analysis and formalin-fixed samples were used for metallothionein staining. Immunohistochemically, metallothionein induction by 1.5y-Cd exposure was higher in the renal cortex than in the liver. Metallothionein expression was reduced after 2y-Cd administration compared to the 1.5y-Cd-exposed mice. Cd-induced tissue damage became marked in the 2y-Cd-exposed mice compared to the 1.5y-Cd-exposed mice, in which nephrotoxicity was more prominent than hepatotoxicity. Cd yield was higher in the renal cortex of the 2y-Cd-exposed mouse than in that of the 1.5y-Cd-exposed mouse, whereas no such increasing tendency was found in the liver. Compared to the control, the Cd-exposed mice markedly accumulated zinc in the liver and renal cortex. In the Cd-exposed mice, iron was mildly accumulated in the renal cortex and was slightly deprived in the liver. Elemental maps showed that a large amount of Cd was spatially combined with zinc in the 1.5y-Cd mouse. Free Cd became abundant in the 2y-Cd-exposed mouse. In addition, a small amount of Cd was colocalized with iron. The data suggest that zinc may contribute to protect against oral-administrated Cd toxicity, and impaired induction of MT may participate in hepato-nephrotoxicity of the 2y-Cd-exposed mouse.
Subject(s)
Cadmium/pharmacology , Spectrometry, X-Ray Emission/methods , Administration, Oral , Animals , Cadmium/administration & dosage , Female , Immunohistochemistry , Iron/metabolism , Kidney/drug effects , Kidney/metabolism , Liver/drug effects , Liver/metabolism , Metallothionein/metabolism , Mice , Mice, Inbred ICR , Zinc/metabolismABSTRACT
SETTING: Representative sample survey of knowledge, attitudes and practices (KAP) for tuberculosis among private general practitioners (GPs) in 1993 in Korea, OBJECTIVE: To investigate the KAP of general practitioners on the prevention and treatment of tuberculosis. DESIGN: Questionnaire surveys were performed for 923 private general practitioners through 29 health centres. RESULTS: 49% of GPs considered that the Korean tuberculosis situation is not serious. 54% were worried about infection from patients. 47% answered that BCG vaccination causes untoward reactions with no or limited effectiveness. 47% considered the National Tuberculosis Programme (NTP) unfavourably. Over 50% did not consider sputum examination essential in case finding/diagnosis, and 75% in monitoring of treatment response. For initial treatment of active tuberculosis, only 11% were prescribing the current Korean NTP's six-month standard regimen. 73% were giving currently non-recommendable regimens, and 16% unacceptably bad regimens. However, this situation could be improved, as 80% of GPs expressed the wish to acquire knowledge. CONCLUSION: Many misunderstandings were found in the field of transmission, BCG vaccination and the performance of the NTP; sputum examinations were considerably neglected in case finding/diagnosis and treatment monitoring. As for treatment, 89% were giving either non-recommendable regimens or bad regimens.
