Kanae Hosoda

Uptake of cadmium in meals from the digestive tract of young non-smoking Japanese female volunteers.

Uptake of Cadmium in Meals from the Digestive Tract of Young Non‐smoking Japanese Female Volunteers: Yuriko Kikuchi, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University

Biological monitoring of indium by means of graphite furnace atomic absorption spectrophotometry in workers exposed to particles of indium compounds.

Since the rapid expansion of III-V semiconductor and liquid crystal display production, the consumption of indium (In) has been increasing. From the mid-1990s, animal experiments have shown that the inhalation or intratracheal instillation of In compounds causes severe lung inflammation and mild adverse reproductive effects. Although the health effects of In on workers’ respiratory and reproductive systems have been unclear to date, assessing the exposure-effect relationships in Inexposed workers is a serious concern, but no information is available on the exposure-effect relationships in workers. This study attempted to estimate the In concentration in biological specimens of In-exposed workers, and to clarify the relationships among them.

Serum Levels of Retinol and Other Antioxidants for Hearing Impairment Among Japanese Older Adults

BACKGROUND The objective of this study was to assess the relation between serum levels of retinol and other antioxidants and hearing impairment in Japanese older adults. METHODS This is a community-based cross-sectional study comprising 762 residents aged 65 years or older in Kurabuchi, Gumma, Japan. We measured serum retinol and other antioxidants (alpha- and gamma-tocopherols, and carotenoids including beta-cryptoxanthin, alpha- and beta-carotenes, lycopene, and lutein plus zeaxanthin) by high-performance liquid chromatography and divided each measurement into quartiles. Hearing impairment was defined as a failure to hear a 30-dB hearing level (HL) signal at 1 kHz and a 40-dB HL signal at 4 kHz in the better ear in pure-tone audiometric tests. The odds ratios (OR) for hearing impairment were calculated for each of the upper three quartiles of retinol and other antioxidant levels relative to the lowest quartile. RESULTS Crude analysis showed that serum levels of retinol and provitamin A carotenoids (beta-cryptoxanthin, and alpha- and beta-carotenes) were inversely related to the prevalence of hearing impairment. The multiadjusted ORs (95% confidence intervals) for the highest quartile of retinol and the provitamin A family (combinations of provitamin A carotenoids) compared with the lowest were 0.51 (0.26-1.00) and 0.53 (0.27-1.02), respectively. A dose-response relationship was observed for retinol (p = .03) and provitamin A (p = .09). CONCLUSION Increased serum levels of retinol and provitamin A carotenoids were clearly associated with a decreased prevalence of hearing impairment.

Effects of intratracheally administered indium phosphide on male fischer 344 rats

Effects of Intratracheally Administered Indium Phosphide on Male Fischer 344 Rats: Takamoto Uemura, et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University—Objective—To examine the effects of intratracheally administered indium phosphide (InP) and distribution of indium on male Fischer 344 rats. Materials and methods—Rats were intratracheally given 0, 1, 10 or 100 mg/kg of InP with a mean diameter of 0.8pm and observed for 1 and 7 days. The bronchoalveolar lavage fluid (BALF) was examined biochemically and cytologically. Serum biochemical, hematological and histopathological examinations were done, and the indium concentration in organs and serum was determined. Findings—The number of neutrophils in BALF remarkably increased in a dose‐effect manner 1 and 7 days after administration and InP particles were phagocytized in the macrophages. Total protein (TP), lactate dehydrogenase (LDH), total phospholipid (TPL) and total cholesterol (T‐Cho) in BALF showed a clear dose‐effect relationship 7 days after administration. Indium was detected in the liver and spleen and increased in a dose‐related manner on the next day and 7 days after administration. Serum indium was detected in the group given more than 10 mg/kg but did not reveal a dose relationship. Histopathological examination of the lungs showed phagocytized InP particles in the macrophages and the migration of neutrophiles in the alveoli. InP particles remained in the bronchioles and alveoli until 7 days after. No histopathological changes were detected in the liver or spleen. A hematological study did not reveal significant findings, interpretation—Intratracheally administered InP particles cause pulmonary inflammation and those particles remain in the lower airways for at least 7 days. Phagocytosis of macrophages may contribute to their disposal and distribution to the liver and spleen. Further study is required with particles with a lower toxic activity than InP and with the same particle size as the InP used in this study, to clarify their specific toxicity. Simultaneously longer observation is needed to assess toxicity in the other organs after distribution.

In Vitro Solubility and In Vivo Toxicity of Indium Phosphide.

In Vitro Solubility and In Vivo Toxicity of Indium Phosphide: Isamu Kabe et al. Department of Preventive Medicine and Public Health, School of Medicine, Keio University—This study was designed to clarify the in vitro solubility and the in vivo basic toxicity of indium phosphide (InP). InP powder was clearly soluble in synthetic gastric fluid and quite insoluble in saline or synthetic lung fluid. Male ICR mice (SPF grade) were given InP at the doses of 0, 1,000, 3,000, and 5,000 mg/kg, intraperitoneally (i. p.) or orally (p. o.). During a 2‐week observation, no mice died. In i. p. treated mice, the serum indium concentration showed a dose‐dependent increase, and indium mainly accumulated in the lungs and liver. Dose‐dependent increases in lung and spleen weight were observed. Black granules of InP were deposited in the lymph nodes, spleen, lungs, and liver. Extramedullary granulopoiesis was observed. And eosinophilic exudates and mononuclear cells were seen in the pulmonary alveoli. Considering these findings, InP particles were presumably transferred to the spleen, liver, and lungs by way of lym‐ phokinetics, causing reticuloendothelial responses. Hematological examination showed increased proportions of stab cells and monocytes in 5000 mg/kg i.p. dosed mice. The p. o. administered mice showed no clear relationship between the dose and biological effects.

Reevaluation of urinary excretion of coproporphyrins in lead-exposed workers

Urinary concentrations of coproporphyrin I and III (CP I and III) were determined by high-performance liquid chromatography in 131 male workers exposed to lead, and the relationships between lead exposure and urinary coproporphyrins were reevaluated. CP I had a statistically significant correlation with lead in the blood (Pb-B), but it was not useful as an indicator of the effect of lead on heme metabolism. On the other hand, CP III had a good correlation with Pb-B and markedly increased when Pb-B levels exceeded 40 to 50 micrograms/100 ml. Both sensitivity and specificity were more than 80% when the health-based Pb-B limit and the screening level of CP III were fixed at 50 micrograms/100 ml and 50 micrograms/g creatinine, respectively. In conclusion, measurement of CP III is sufficiently sensitive and specific enough in practice for the early detection of health effects due to lead exposure in the same way as the measurement of delta-aminolevulinic acid in urine.

Short-term Changes in Cadmium in Feces, Blood and Urine after Dietary Cadmium Intake in Young Japanese Females

Diet and smoking are the major routes of cadmium (Cd) intake. In Japanese populations, dietary Cd intake is higher than in other countries, for example, China, Finland, Germany, Malaysia, and Sweden. In determining a tolerable daily/weekly intake of Cd from foods and beverages, the rate of absorption of Cd from the digestive organs is a crucial factor, but it remains controversial. To design a human volunteer experiment for assessing the absorption rate, a preliminary experiment was performed to clarify short-term intake-output balance of Cd and to estimate better biological monitoring parameters for Cd absorption.