BACKGROUND: Organic chemicals have been known to cause allergic diseases such as bronchial asthma and hypersensitivity pneumonitis; however, the possibility that they do not cause irreversible pulmonary fibrosis has not been considered. Polyacrylic acid (PAA), an organic chemical, has caused irreversible progressive pulmonary fibrosis in exposed workers, indicating its potential to induce pulmonary inflammation and fibrosis. Although intratracheal instillation studies are commonly used for evaluating lung pathology, traditional methods face challenges with chemical substances, particularly nanoparticles, which tend to aggregate in suspension and prevent uniform pulmonary distribution. Such aggregation alters the qualitative and quantitative responses to lung injury, limiting accurate assessment of lung pathology. To overcome this limitation, we developed a 'molecular dispersion method' that uses pH modification to negative charges to PAA particles, maintaining their dispersion. Using this method, we investigated the effects of PAA on pulmonary inflammation and fibrosis in a rat model. METHODS: F344 rats were intratracheally instilled with PAA using molecular dispersion (0.1 mg/rat, 1.0 mg/rat), PAA without molecular dispersion (1.0 mg/rat), and normal saline (control group). Rats were sacrificed at 3 days, 1 week, 1 month, 3 months, and 6 months after exposure to examine inflammatory and fibrotic responses. RESULTS: PAA caused persistent increases in neutrophil influx in the bronchoalveolar lavage fluid (BALF) from 3 days to 1 month following instillation. In histopathological findings, the group with molecular dispersion had almost no inflammatory masses in the lung tissue compared to the group without molecular dispersion, and exhibited relatively uniform dispersion. CONCLUSION Intratracheal instillation of dispersed PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA might have pulmonary inflammogenicity and fibrogenicity. Intrapulmonary dispersion of PAA particles following intratracheal instillation studies using the molecular dispersion method was similar to that following inhalation studies.
Animals ; Rats, Inbred F344 ; Acrylic Resins/adverse effects* ; Rats ; Inhalation Exposure/adverse effects* ; Male ; Pulmonary Fibrosis/pathology* ; Pneumonia/pathology* ; Lung/pathology* ; Bronchoalveolar Lavage Fluid/cytology*

In accordance with the new model-core-curriculum for medical education, the current status of education about the science of radiation health was surveyed in all medical schools in Japan. Among the four learning points related to the “Biological effects of radiation and radiation hazards” , about half of the schools covered issues on “radiation and human body” and the “effect of medical radiation exposure” in one, or less than one, 60-minutes class, but did not touch on “radiation risk communication” and “radiological disaster medicine” . A significant deviation of human resources was also observed between schools. Learning tools such as presentation files and video content were preferred as education support materials. Therefore, development and distribution of the learning tools, especially in “radiation risk communication” and “radiological disaster medicine” , may be a first step to promoting high-quality education on the science of radiation health risk in each school’s curriculum.

1) Common training for the introduction of research and the elective and individual guidance for research should be devised in a manner attractive to graduate students of medicine.
2) To train researchers, a graduate school of clinical medicine should be established as a professional school, separate from an ordinary graduate school.
3) To promote basic medical sciences, the capacity of graduate schools of basic medical sciences should be reduced despite the number of teachers and the bold plan for the financial support of students.

The aim of this study was to evaluate the association between a number of variables and the smokingbehavior of students at 2 medical and 4 nursing schools. Multivariate analysis was applied to clarify theassociation between the Brinkman index and 12 other independent variables.
The study population consisted of 1, 207 medical and 682 nursing students in Japan.
1) 35.4% of medical students (1-6th grades), 12.5% of nursing students and 28.7% of medical students (1-3rd grades) smoked. Medical students in the 5th or 6th grade smoked more frequently than the otherstudents.
2) Smokers in medical school and those giving up smoking in nursing school had more knowledge aboutsmoking and its physical effects than the others.
3) Multiple regression analysis showed that the coefficients of determination for the Brinkman indiceswere 0.197 in medical school (1-6th grades), 0.055 in nursing school and 0.106 in medical schools (1-3rd grades). The main independent variables were age, sex and maternal smoking history.

Two hundred and thirty adipose tissues were collected from inpatients, who had undergone an operation and an autopsy in the Saku Central Hospital from 1980 to 1982. Organochlorine pesticides were extracted from the adipose tissues and determined by gas-liquid chromatography with an electron-capture detector.
The mean value was 1, 429 ppm for total BHC among males, and 1.665 ppm among females, 4.893 ppm and 3.791 ppm for total DDT, 1.082 ppm and 0.782 ppm for PCB, respectively. Regression analysis between the total BHC residue and the ages of patients indicated a positive correlation for both sexs. As for the relation between the rate of obesity and the residues, low rates of obesity (-10%--19%) were most significantly correlated with high values of total BHC, total DDT and PCB.
We also discussed relations between cancerous diseases and the residues.

Over the past eight years, small doses of an organophosphorous insecticide known in Japan as Sumithion (fenitrothion) have been administered weekly to rehsus monkeys and beagles. In this report, the results obtained during the past three years are discussed.
During the period, two monkeys and one hound died. Pathohistological examination revealed degeneration and disappearance-regeneration of liver tissues, edema of oculomotor muscle stomas, spinal cords and oculomotorius nerve fibers, and atrophy of limph nodes. These are considered the effects of the insecticide.
The surviving animals did not develop any abnormal changes or signs associated with Sumithion-induced disorders. Weight loss was not observed. Routine blood tests were negative. However, serum chemical analyses conducted in the seventh year showed that there are statistically significant differences in GPT, LDH and cholinestrase activity among the animals.

We investigated the content of NO₃-N in the well water of the eastern, middle and nothern districts of Nagano Prefecture. The NO₃-N content seasonally changes and takes on the pattern of a high in summer and a low in winter.
Rain is considered to dilute the contaminated well water, but it lets NO₃-N flow from the soil into the.well water, when the rain is poured by a typhoon. As a result, a high content of NO₃-N is measured in the well water.
The water sample of 25 out of 85 wells in Matsukawa Town exceeded the tolerance level of NO₃-N (10 ppm, but 44.3 ppm in terms of NO₃^-).
By crop area, the amount of NO₃-N was highest in the fruitgrowing area, which was followed in order of the vegetable-growing area, the flower-growing and the rice planting area.
We consider that the contamination of well water is caused both by chemical fertilizers and the less absorbility of the soil.