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Biomedical subjects

S Nakachi

Publications and source records attributed to S Nakachi.

12 recordsLinked to original sources
PubMed2001

Wide use of skin-lightening soap may cause mercury poisoning in Kenya.

In a previous study, we speculated that some of the high mercury levels observed in head hair from a total of 14 subjects who resided around Lake Victoria, Tanzania, might be attributable to the habitual use of toilet soap containing considerable amounts of mercury (Harada et al. Sci Total Environ 1999;227:249-256). In August 1998, the current study was conducted to investigate if such mercury-containing soap was also available in the surroundings of Lake Victoria, Kenya, and if so, its toxic effects. A total of nine goldminers, 44 fishermen and their families, and 12 residents of Kisumu City, Kenya, volunteered for the study. Fourteen types of toilet soap were collected in Kisumu. Total mercury content was very significantly higher than in European-made soap (0.47-1.7%, as mercury iodide) compared with Kenya-made soap (0.41 x 10(-4)-6.2 x 10(-4)%). Indeed, all the subjects with a high hair mercury level (> 36.1 ppm) had made habitual use of European-made soap, accompanied by various symptoms, such as tremor, lassitude, vertigo, neurosthenia, and black and white blots, suggesting inorganic-mercury poisoning. On the other hand, any subject who had used soap other than the European-made soap, did not exceed a mercury level of 10 ppm in hair that is well within normal limits (Harada et al. Sci Total Environ 1999:227:249-256). The findings obtained suggest that the mercury-containing soap must be barred from circulation without delay, and that the residents' health in addition to the environmental pollution in Lake Victoria (Kenya as well as Tanzania) should be kept under close observation.

Adult↗
PubMed1999

Monitoring of mercury pollution in Tanzania: relation between head hair mercury and health.

Through 1996 into 1997, a spot investigation on mercury contamination was conducted three times in Tanzania, especially around the Lake Victoria. A total of 150 goldminers, 103 fishermen and their families, and 19 residents of Mwanza City volunteered for the current study. A high total mercury level of 48.3 ppm (near to 50 ppm, a critical level of Minamata disease) and over in the head hair was observed in six goldminers (highest value, 953 ppm), four fishermen and their families (highest value, 416 ppm), and four Mwanza people (highest value, 474 ppm). With the exception of these 14 subjects, however, each mean total mercury level was well within the normal range (below 10 ppm). Out of the goldminers examined, 14 cases were diagnosed as a mild form of inorganic-mercury poisoning according to their clinical symptoms (such as polyneuropathy mercurialis, neuroasthemia, or tremor mercurialis) and the low ratio of methylmercury to total mercury, whereas neither inorganic-mercury poisoning nor methylmercury poisoning (Minamata disease) was noted in the fishermen and their families or in the Mwanza people. In addition, some subjects who showed a high total mercury level made habitual use of toilet soap containing much mercury. The findings obtained suggest that the mercury pollution in Tanzania is not very serious, however, it should be observed continuously.

Adolescent↗
PubMed1998

[Analysis of air pollution and prevalence rate of allergic diseases among elementary school children in Kawaguchi and Hatogaya city].

Kawaguchi and Hatogaya City are located on the northern edge of Tokyo. We analysed between air pollution and prevalence rate of allergic diseases among elementary school children in this area. A prevalence rate of allergic diseases in 1996 May and June was as follows; bronchial asthma 13.5%, atopic dermatitis 24.5%, allergic rhinitis and/or conjunctivitis 22.8%, urticaria 12.4%, food allergy 7.8% and drug allergy 2.2%, respectively. Air pollution of this area was analysed to check the levels of nitrogen dioxide (NO2), sulfur dioxide (SO2) and suspended particulate matters (SPM). NO2 pollution was relatively high in urban area, and SPM pollution was especially high around the highways. SO2 pollution was lower than the environmental standard. No relationship was found between the prevalence rate of bronchial asthma, atopic dermatitis, allergic rhinitis and/or conjunctivitis and air pollution, but it was found that these diseases are slightly related to population density (p < 0.1, p < 0.01, p < 0.1, respectively).

Air Pollutants↗
PubMed1993

[Estimation of asbestos exposure among workers repairing asbestos cement pipes used for conduits].

Asbestos cement pipes (ACPs) containing 15 to 20% chrysotile or crocidolite have been used for underground conduits. Even today 16.2% of all conduits in Japan are ACPs, though the production of ACPs was suspended in 1985. When such a conduit is accidentally damaged the workers belonging to the Waterworks Bureau of a local government cut off the damaged conduit using a high-speed disk cutter and replace it with a new conduit. This operation develops a cloud of dust and the workers involved run the risk of asbestos exposure. It was the aim of the present study to estimate asbestos exposure levels among these workers. First, in the experiment, we established the typical working conditions and requested an experienced worker to cut an ACP using a high-speed disc cutter in a hole dug in the ground as he routinely does. The experiment was repeated three times. During a bout of each experiment, dust was sampled at several points both inside and outside the hole. Second, a self-administered questionnaire survey was conducted to obtain information from the workers regarding their working conditions in cutting ACPs. The subjects of the survey were 1,048 men belonging to conduit repair sections of the Waterworks Bureau of 119 local governments. The results obtained can be summarized as follows. 1) Each bout of cutting ACPs required about five minutes. The concentration of asbestos fibers longer than 5 microns with 3:1 aspect ratio ranged from 48 to 170 fibers/ml (92 fibers/ml on an average) inside and 1.7 to 15 fibers/ml outside the hole. The concentration inside the hole exceeded the ceiling limit (10 fibers/ml) recommended for asbestos by the Japanese Association of Industrial Health. A concentration of 92 fibers/ml is equivalent to 0.96 fibers/ml as 8-h time-weighted average. 2) The number of subjects with experience of cutting ACPs was 849 (81.0%). The average length of service in conduit repair section was 14.2 yr. Based on the information obtained from each subject regarding the average working days per yr for each decade from 1946, the cumulative days to date expended in cutting ACPs was estimated to average 235 d, that is, 17 d per yr. Only 18.1% of the subjects used a protective respiratory device.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

[Occupational dust exposure and prevalence of respiratory symptoms among conduit repair workers].

The amount of water supply in Japan was 16 billion ton as of 1989. Water from rivers and other sources is purified, sterilized and then supplied to the residents through conduits. When conduits are accidentally damaged, they must be repaired by the workers of the Waterworks Bureau of the local government. In this task, the workers are exposed to airborne dust which develops while digging and filling the ground and cutting the conduit and the concrete covering the road. The purpose of the present study was to estimate the airborne dust exposure level among the workers and to investigate its effect on their respiratory organs. First, we measured the total dust exposure concentration of 20 conduit repair workers and the total dust concentration in 10 office rooms. Second, we conducted a self-administered questionnaire survey to estimate the prevalence of respiratory symptoms among the employees of 119 Waterworks Bureaus. The subjects of the analysis were 322 conduit repair workers and as their controls 345 clerical/engineering workers. The results can be summarized as follows: 1) The average daily total dust exposure while repairing conduits ranged from 0.27 to 5.05 mg/m3 (mean = 0.91 mg/m3), while that while exchanging water meters from 0.23 to 0.52 mg/m3 (mean 0.41 mg/m3). These values were 4.6 and 2.1 fold higher than the total dust concentration in office rooms (mean = 0.20 mg/m3). 2) With the use of fluorescent X-ray method, iron and aluminum were detected in all samples collected while repairing conduits and the intensity of X-ray increased with increase in weight of collected dust. Iron exposure concentration ranged from 0.006 to 0.095 mg/m3, which is much higher than the levels in the air in urban areas. Iron and aluminum could not be detected by fluorescent X-ray method in most of the samples collected in office rooms. These findings indicate that the main element in the dust collected while repairing conduits is soil, while that in office rooms is tobacco smoke. 3) Among the smokers, the prevalence of cough and phlegm was significantly higher in conduit repair workers than in clerical/engineering workers. A similar tendency was observed among ex-smokers and non-smokers, but the difference was not significant.

Adult↗
PubMed1993

[Neonatal blood IgE levels on filter paper as indicators of atopic disease--a follow-up at the age 18 months and 5 years].

Measurements of IgE levels in the blood of neonates were investigated using filter paper for blood collection in mass screening of congenital metabolic disorders by time-resolved fluoroimmunometric assay. In an analysis of the present result, IgE value of at least 0.015 U/ml, the measurement limit, were considered as high. High IgE levels in filter paper blood were seen in 28 (7.2%) of the 389 cases. When the relation with serum IgE levels at 18 months of age was investigated in 134 of 389 subjects, high serum IgE levels were also found in 86.7% of the subjects with high IgE levels in filter paper blood. In addition, when the relation between family history of atopic disease and presence of atopic disease in the first 18 months of age was investigated in 203 of the 389 subjects, 90% of the subjects with a family history of atopic disease and high IgE levels in filter paper blood developed atopic disease. On the other, 50% and 24.7% of the subjects with low IgE levels in filter paper blood and an atopic family history or no atopic family history, developed atopic disease, respectively. There were significant differences among these three groups (p < 0.01). When the relation between IgE levels in filter paper blood and presence of atopic disease in the first 5 years of age was investigated in 87 of the 389 subjects. 95% of the subjects with high IgE levels in filter paper blood developed atopic disease, though 57% of the subjects with low IgE levels developed atopic disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1991

Increased expression of Fc epsilon R2/CD23 on peripheral blood B lymphocytes and serum IgE levels in Kawasaki disease.

We analyzed the expression of Fc epsilon R2/CD23 on the peripheral blood B lymphocytes of 10 patients with Kawasaki disease (KD) using a fluorescence-activated cell sorter. The absolute count of CD23-positive B lymphocytes and the ratio of CD23-positive B lymphocytes to B lymphocytes were high during the acute stage of KD in comparison to those during the convalescent stage and in control subjects. In addition, both the increased number of CD23-positive B lymphocytes and the increased serum IgE levels appeared during the latter part of the acute stage. These results suggest that the increased number of CD23-positive B lymphocytes during the latter part of the acute stage in KD reflect the activation of B lymphocytes and have an important role in IgE-mediated immunity.

Antibodies, Monoclonal↗
PubMed1990

Reduction of peripheral blood macrophages/monocytes in Kawasaki disease by intravenous gammaglobulin.

The effects of intravenous gammaglobulin (IVGG) on changes in the peripheral blood mononuclear cell subsets during acute Kawasaki disease (KD) were studied by a random selection trial of IVGG plus Aspirin (group G) compared to Aspirin alone (group A). Group G received IVGG with 200 mg/kg per day x 5 dose. The absolute counts of peripheral blood mononuclear cell subsets were assayed by a fluorescence-activated cell sorter using monoclonal antibodies of Leu series. Before therapy, patients in each treatment group had increased counts of CD14 + macrophage/monocytes compared to healthy childhood controls (P less than 0.01). After IVGG treatment group G underwent a greater decrease in their CD14 + macrophage/monocyte counts (P less than 0.01) than group A. The changes of CD3+ T cells. Leu 7+ NK/K cells and CD19+ B cells in the peripheral blood mononuclear cell subsets with treatment in group G, were similar to those in group A. These results suggest the possibility that IVGG therapy is effective in KD by modulating macrophages/monocytes.

Aged↗
PubMed1990

Expression of Fc epsilon R2/CD23 on peripheral blood macrophages/monocytes in Kawasaki disease.

We analyzed the expression of Fc epsilon R2/CD23 on peripheral blood macrophages/monocytes in 12 patients with Kawasaki disease (KD) using a fluorescence-activated cell sorter. The absolute counts of CD14+ macrophages/monocytes and CD23+ macrophages/monocytes were high, and were positively correlated during the acute stage of KD. These results indicate that the increased number of macrophages/monocytes during acute KD have the Fc epsilon R2/CD23 antigen present on the surface of the cells, suggesting that peripheral blood macrophages/monocytes have been activated.

Acute Disease↗
PubMed1990

Neonate blood IgE levels on filter paper as indicators of atopic disease.

Measurements of IgE levels in the blood of neonates were investigated using filter paper for blood collection in mass screening of congenital metabolic disorders. Time-resolved fluoroimmunometric assay system for the measurement of filter paper blood IgE levels was also studied. In an analysis of the present results, IgE values of at least 0.015U/ml, the measurement limit, were considered as high. High IgE levels in filter paper blood were seen in 28 (7.2%) of the 389 cases. When the relation with serum IgE levels at 18 months of age was investigated in 134 of 389 subjects, high serum IgE levels were also found in about 86.7% of the subjects with high IgE levels in filter paper blood. In addition, when the relation between family history of atopic disease and presence of atopic disease in the first 18 months of age was investigated in 203 of the 389 subjects, about 90% of the subjects with a family history of atopic disease and high IgE levels in filter paper blood developed atopic disease. Since filter paper blood is routinely collected in Japan, IgE levels in this blood should be widely checked for the prediction of onset of atopic disease in infants.

Female↗
PubMed1990

[Work load of nursery teachers in a nursery school. Relationship between age of children and work load].

Time study of six nursery teachers of children aged 0 to 5 was conducted at a public nursery school to ascertain their work load, and the results obtained were examined from the following two viewpoints. First, comparison was made between the results obtained by the following two methods of analysis; 1) An observer recorded the work contents and the working postures of a nursery teacher at place of work in one-minute units. 2) The nursery teacher was recorded on video tape and the analysis of the work contents and the working postures was made in one-second units. Second, comparison was made between the work loads (work content, working posture, walking, lifting children and recess) of nursery teachers of children of different age group. The results could be summarized as follows: 1. The results of analysis made by the two methods of the work contents and the working postures were in good agreement. 2. The higher the age of children in the class, the longer was the cumulative time for "indoor group nurture" and the shorter was the cumulative time for "help and care for feeding", "help and care for afternoon nap" and "help and care for excretion". 3. The higher the age of children in the class, the longer was the cumulative time of "standing" in a nursery teacher and the shorter was the cumulative time of "sitting on the floor". The total time of "bending forward", "squatting" and "rising on the knee" occupied 20% of the working hours on an average and was not related clearly to the age of children. 4. The frequency of walking was not found to be related to the age of children. 5. The nursery teachers of children aged 0 and 1 lifted children much more frequently among all nursery teachers. 6. The recess away from children was rarely observed throughout the day.

Age Factors↗