OBJECTIVEThe aim of this study is to clarify the long-term dynamics of the red tide occurring in Lake Kawaguchi.

METHODSThe measurement of environmental factors and water sampling were carried out monthly at a fixed station in Lake Kawaguchi's center basin from April 1993 to March 2004. On June 26, 1995, the horizontal distribution ofPeridinium bipes was investigated using a plastic pipe, obtaining 0∼1-m layers of water column samples at 68 locations across the entire lake.

RESULTSP. bipes showed an explosive growth and formed a freshwater red tide in the early summer of 1995, when the nutrient level was higher than those in the other years, particularly the phosphate concentration in the surface layer. The dissolved total phosphorus (DTP) concentration was sufficient forP. bipes growth in that year. In the study of its horizontal distribution,P. bipes was found at all the locations. The numbers of cells per milliliter ranged from 67 to 5360, averaging 1094±987 cells/ml, with particularly high densities along the northern shore. Since then,P. bipes has annually averaged about 25 cells/ml in Lake Kawaguchi.

CONCLUSIONWe observed that the red tide caused byP. bipes correlates with a high DTP concentration in Lake Kawaguchi.

We have carried out the mass survey for diabetes mellitus by a 50 g GTT as the first screening since 1971. Average incidences of diabetic pattern, IGT pattern, borderline pattern and normal pattern in a Glucose Tolerance Test (GTT) were 2.3±1.8%, 6.6±1.7%, 19.8±6.6% and 71.4 ±7.8%, respectively. 21 males and 6 females were found to be diabetic by this survey for 11 years. Insulinogenic indices (I. Is.) of diabetic, IGT, borderline and normal patterns were 0.13±0.07, 0.70±0.37, 0.58±0.40 and 1.05±0.30, respectively, and the values of I. I. in diabetics and borderline diabetics were significantly lower than that in the normal pattern. A I. I. in the subjects who have revealed the normal glucose tolerance every year for 11 year, 2.62±1.28, was high in the normal range. On the other hand, a I. I. in the subjects who became overtly diabetic from the IGT, borderline or normal pattern, 0.36±0.31, was significantly lower. Therefore, taking into consideration that one of the characteristics of NIDDM is low insulin response to glucose, the mass survey for diabetes mellitus should be carried out by a Glucose Tolerance Test (GTT) as the first screening with the measurement of plasma insulin concentrations. A follow-up study for the low insulin responder is considered to be one of the most preferable investigations for the detection of the early stage of diabetes mellitus.

[Background] Presenteeism, defined as the practice of sick workers who come to work, and whose work performance effectiveness has been reduced due to various signs and symptoms, causes a significant financial loss to companies. However, comprehensive and effective occupational health countermeasures have not yet been presented. Therefore, we report here the results of an interim analysis to determine whether an allowance for acupuncture treatment is beneficial for workers' presenteeism. [Methods] A four-week randomized intergroup comparative study was conducted on office workers who were aware of their presenteeism. Participants were allocated to either the control group, in which regular recommended presenteeism countermeasures for each workplace were implemented arbitrarily, or to the intervention group in which an allowance of up to 8,000 was given for acupuncture treatment, in addition to the usual arbitrary measures. The primary endpoint was the WHO-HPQ relative presenteeism score: a score lower than 1 indicates lower work performance; and it was analyzed with the "full analysis set" population.[Results] A total of 52 patients were assigned to the intervention group (n = 30) and the control group (n = 22). On average, the intervention group received acupuncture treatments 1.4 times for stiff neck and shoulders (67%), lower back pain (26%), depression (5%), and allergies (2%), and paid a total of 7,219; and 6,556 was paid as an expense allowance. As a result, the relative presenteeism score was 0.95 in the intervention group, compared to 0.91 in the control group, with a between-group difference of 0.04 (ES (r) = 0.22, P = 0.12).[Conclusions] With a total of up to 8,000 offered to office workers who were aware of their presenteeism, an acupuncture treatment allowance for a four-week period was provided 1.4 times on average. The results suggested that the treatment allowance would increase workers' performance efficiency by about 4% (equivalent to 19,691 per person) compared to those without it.