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Volume 30 (1975 - 197･･･
- Issue 6 Pages 593-
- Issue 5 Pages 523-
- Issue 4 Pages 461-
- Issue 3 Pages 387-
- Issue 2 Pages 289-
Volume 30, Issue 4
Displaying 1-5 of 5 articles from this issue
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Masahiko Taira1975 Volume 30 Issue 4 Pages 461-489
Published: October 28, 1975
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThe studies conducted at Kumamoto University concluded that the Minamata disease is caused by methyl mercury. In the course of a nationwide survey made thereafter on environmental pollution by mercury, methyl mercury was detected in fish and human hairs which were supposedly free from artificial contamination by mercury. In particular, 60 to 70% of mercury found in tuna caught in oceans has been reported to be in the form of methyl mercury. An abnormally high mercury content in fish has also been reported in Sweden. Westöö carried out analyses of mercury in fish and other foodstuffs and claimed that 80 to 100% of mercury is present as methyl mercury.
To elucidate the origin of such methyl mercury in nature and the effects of methyl mercury on mankind from the standpoint of public health, microbiological and ecological studies were undertaken on microbial conversion of inorganic mercury into organic mercury and of a process of the biological chain. A mercury-resistant bacterium belonging to Pseudomonas was separated from sewage water and biological synthesis and decomposition of organic mercury by this bacterium were investigated. Following this, microorganisms growing in a zone of mercury deposits, soils, rivers and seas and certain eumycetes were found to possess the ability to synthesize organic mercury. Hence, the possibility of conversion of inorganic mercury into organic mercury in nature was recognized. Furthermore, the extent of synthesis of organic mercury and the extent of accumulation of methyl mercury in fish by way of biological concentration were studied with the aid of ecological means. The microbially synthesized methyl mercury is concentrated by the food chain and an unusually high mercury content is sometimes found in fish. However, accumulation of methyl mercury in fish seldom proceeds to such a high level as to cause mercury poisoning, unless continual flow of methyl mercury in abnormally large quantities is present, as has been known in the case of the Minamata disease. Therefore, detection of an abnormally large amount of mercury in fish or shellfish suggests artificial contamination by mercury in one way or another, and a countermeasure must be worked out.View full abstractDownload PDF (3262K) -
Observations in Summer and in WinterHisanori Nagata, Yuzo Takahashi1975 Volume 30 Issue 4 Pages 490-496
Published: October 28, 1975
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSWhen the number of deaths (excluding deaths due to external causes) of Kyoto citizens which occurred in Kyoto city every day from July 18 to September 10, 1971 and from January 7 to March 1, 1972 were investigated, it was found that the number of deaths fluctuated considerably from day to day both in summer and in winter (Fig. 1)
As variables indicating meteorological conditions, X1: mean of average air temperature on the day and the previous day of the death (mean of two days), X2: mean of average air temperature on the day and the preceeding six days of the death (mean of seven days), X3, X4: average humidity (mean of two days and mean of seven days), X5, X6: average wind velocity (mean of two days and mean of seven days), X7, X8: average SO2 concentration in air (mean of two days and mean of seven days), X9, X10: maximum (in summer) or minimum (in winter) air temperature (mean of two days and mean of seven days), X11: difference of maximum and minimum air temperature (mean of two days), X12: difference of mean air temperature between the day and the previous day of the death were adopted, and the correlations between the daily number of deaths and each of the above variables were calculated (Table 4) In summer X1, X2, X9, X10 and X11 were positively and X3 was negatively correlated with the daily number of deaths, but in winter no variables significantly correlated with the daily number of deaths. Furthermore, the multiple regression equation of the daily number of deaths on eight predictor variables (X1-X8) was obtained (table 5). However, the multiple correlation coefficient in summer was only slightly greater than the correlation coefficient between the daily number of deaths and average air temperature (mean of two days) and that in winter was not statistically significant.
Based on these findings, the extent and the mode of the effect of meteorological conditions, especially of air temperature on death or human health in summer and in winter were discussed.View full abstractDownload PDF (885K) -
Teruko Yamane, Nobuo Fukuda, Jiro Inaba, Yoshikazu Nishimura1975 Volume 30 Issue 4 Pages 497-502
Published: October 28, 1975
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSIn an attempt to study the effect of polychlorinated biphenyls on iodine metabolism, Kanechlor KC-400 (a mixture of PCB) was administered to rats.
At 3, 10, 20 and 30 days after a single oral administration of KC-400, the following studies were performed; 1) weighing of liver and thyroid, 2) Kinetics of whole-body 131I-thyroxine, 3) biliary excretion of 131I-thyroxine, 4) analysis of the radioactive components in the bile.
A single administration of 200mg dose of KC-400 drastically affected the iodine metabolism of rats as follows; the weights of liver and thyroid were increased at least for 30 days, elimination of thyroxine from the whole body was accelerated, the biliary excretion of thyroxine was enhanced at least for 20 days, and throxine gluculonide in bile increased for two hours after injection of 131I-thyroxine.View full abstractDownload PDF (1305K) -
Masahiro Nishizumi1975 Volume 30 Issue 4 Pages 503-513
Published: October 28, 1975
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSThe subcellular deposition sites of heavy metals (Pb, Cd and Zn) in their chronic overload were investigated for the liver and kidney of rats, using a modified sulfide-silver method in electron microscope. Silver particles were mainly seen in lysosomes and bile canaliculi in liver cells, and at basal invaginations and vacuoles in renal proximal tubular cells, reducing in amount after administration of BAL. They also infrequently appeared in mitochondria in these cells of the rats given heavy metals in higher concentration. These results suggest that the heavy metals observed are in the process of degradation and excretion in general, and might affect the energy metabolism and protein synthesis of the cells in far advanced poisoning.View full abstractDownload PDF (18381K) -
The Investigation of Temperature Rising Pattern and Amoebocyte Lysate TestAkio Shimohira1975 Volume 30 Issue 4 Pages 514-519
Published: October 28, 1975
Released on J-STAGE: February 17, 2009
JOURNAL FREE ACCESSDetection of pyrogen in injection is generally performed as provided by official regulations. The procedure of the Pyrogen Test depends upon the measurement of body temperature rise until 3 hours after injection in rabbits and does not affect the temperature rising pattern.
Comparetive investigations between bacterial pyrogens and hyperthermic chemicals were made by the observation of temperature rising pattern after injection. In addition, the method employing Amoebocyte lysate prepared by horseshoe crab was compared with the Pyrogen Test.
Results obtained are summarized as follows:
(1) Distinction between bacterial pyrogen and hyperthermic chemicals seemed to be possible by observing the rising temperature pattern.
(2) Carmine known as one of hyperthermic chemicals does not seem to cause fever by chemical substance-Carmine itself, but it may be derived from bacterial pyrogen.
(3) The pyrogenicity on rubber tube connected in disposable transfusion apparatuses seems to be derived from bacterial pyrogen.
(4) With the rise of fever activity in various LPS, a difference of detection sensitivity between Pre-Gel Test and the Pyrogen Test showed a tendency to decrease. Further studies on detection sensitivity in various LPS extracted from various germs would be required to confirm the peculiarity of LPS and preparation of Amoebocyte lysate.View full abstractDownload PDF (763K)
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