Surveillance of polychlorinated biphenyl congeneric patterns in human breast milk from 1973 to 2000 in Osaka, Japan

<p><b>OBJECTIVE</b>Because the analysis of polychlorinated biphenyls (PCBs) in 1970's was performed using a packed column gas chromatograph, with an electron capture detector to determine total-PCB concentration, analytical data obtained by this analysis do not meet the requirement for the risk assessment of PCB congeners. In this context, the present study was carried out to reevaluate the congeneric analysis data by analyzing breast milk fat specimens that have been kept frozen.</p><p><b>METHODS</b>PCB congeners in human breast milk were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) using a capillary column for the selected ion monitoring (SIM) of PCBs.</p><p><b>RESULTS</b>Twelve major PCB congeners were detected in breast milk. The concentrations of all congeners of PCBs in breast milk were found to decrease annually, and their changes over time differed greatly for each congener. Between 1973 and 2000, almost no changes in the proportions of the 12 congeners of heptachlorinated biphenyls (HpCBs) and hexachlorinated biphenyls (HxCBs) were found whereas a marked and a slight decrease in the proportion of pentachlorinated biphenyls (PeCBs) and tetrachlorinated biphenyls (TeCBs), respectively, were observed.</p><p><b>CONCLUSIONS</b>The PCB contamination of the Japanese population is estimated to be largely caused by seafood intake, but the proportions of PCB congeners in fish commodities were different from those in breast milk. The absorption, metabolism and therefore the accumulation of PCBs in the human body differ greatly depending on the congener.</p>

Surveillance of Polychlorinated Biphenyl Congeneric Patterns in Human Breast Milk from 1973 to 2000 in Osaka, Japan

Objective: Because the analysis of polychlorinated biphenyls (PCBs) in 1970’s was performed using a packed column gas chromatograph with an electron capture detector to determine total-PCB concentration, analytical data obtained by this analysis do not meet the requirement for the risk assessment of PCB congeners. In this context, the present study was carried out to reevaluate the congeneric analysis data by analyzing breast milk fat specimens that have been kept frozen. Methods: PCB congeners in human breast milk were analyzed by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) using a capillary column for the selected ion monitoring (SIM) of PCBs. Results: Twelve major PCB congeners were detected in breast milk. The concentrations of all congeners of PCBs in breast milk were found to decrease annually, and their changes over time differed greatly for each congener. Between 1973 and 2000, almost no changes in the proportions of the 12 congeners of heptachlorinated biphenyls (HpCBs) and hexachlorinated biphenyls (HxCBs) were found whereas a marked and a slight decrease in the proportion of pentachlorinated biphenyls (PeCBs) and tetrachlorinated biphenyls (TeCBs), respectively, were observed. Conclusions: The PCB contamination of the Japanese population is estimated to be largely caused by seafood intake, but the proportions of PCB congeners in fish commodities were different from those in breast milk. The absorption, metabolism and therefore the accumulation of PCBs in the human body differ greatly depending on the congener.

DIFFERENTIAL DIGITAL PHOTOPLETHYSMOGRAPHIC ANALYSIS OF MICROCIRCULATORY RESPONSES INDUCED BY ARM POSITION CHANGE AND IMAGE LOADING IN KENDO MASTERS / 体力科学

The purpose of this study was to investigate the differences and effects of positional loading (arm position change) and image loading in Budo (martial arts) competitors, mainly kendo (Japanese fencing) masters. The microcirculatory responses were measured by differential digital photoplethys-mography (ΔDPG) using the characteristics of Budo mental attitude, experience and skill as para-meters.<BR>The subjects were 7 kendo masters of the fifth grade or higher with mean experience of 29 years, 7 kendo athletes, 7 kyudo (Japanese archery) athletes, 5 karate athletes in university sports clubs and 9 middle-aged controls. Positional loading induced myogenic responses and image loading for examining sympathetic effects via the central nervous system on peripheral circulation were mea-sured in the subjects at rest in a sitting position. The following results were obtained<BR>The increase in the . ΔPG-P wave height in response to positional loading was markedly larger in the kendo masters. In particular, the increase when raising the right arm was significantly higher in the kendo masters than in the kyudo and karate athletes (P<0.05) . The decrease in the ΔDPG-P wave height when lowering the right arm was smallest in the kendo masters. There were differences in the peripheral vascular responses between kinds of Budo and levels of skill, which were induced by differences at the time of arm raising.<BR>The DPG-P wave height was significantly lower during stress imaging than before loading in all subjects. The effect of stress imaging was smallest in the kendo masters, and markedly large in the kyudo athletes (P<0.05) . During relaxation imaging, an increase in the ΔDPG-P wave height was observed in the kendo masters alone, and the occurrence of vascular dilation was confirmed.<BR>These results suggest that arteriolar responses of kendo masters are flexible and stable despite their long training period ; and the control and regulation of muscle vascular tone is well-maintained via the central nerve-sympathetic and myogenic coupling.