Saburo Usutani

Histochemical localization of copper in various organs of brindled mice after copper therapy

Copper (Cu) distribution in various organs of brindled mice (BM), an animal model of Menkes disease, was studied histochemically and by atomic‐absorption‐spectrophotometry 7 months after Cu injections. The results were compared with those of untreated BM. In the treated BM brain, a diffuse reduction in Cu‐related staining of neurons and astroglia was still evident, though it had improved to some extent. The reduction was noticeable in the thalamus, brain stem and cerebellum, although intensely stained capillaries were noted occasionally in the retrosplenial and mediobasal temporal areas, including the hippocampus. In the treated BM liver, near normalization of Cu distribution was observed. In the treated BM intestine, the main localization of Cu accumulation was in histiocytes/macrophages in the lamina propria, while in the untreated BM it was in the absorptive and secretory epithelial cells. In the treated BM kidney, there was no clear improvement in Cu distribution. These histochemical results were consistent with the data obtained by the spectrophotometric assay. Electron microscopic histochemistry of affected renal tubular epithelial cells revealed numerous silver grains, which represent Cu++ localization, distributed only within the cytoplasm outside organella and nucleus. This suggests impaired intracellular Cu transport from cytosol to organella, which in the kidney is refractory to the Cu therapy adopted.

ChronologicaI Observations of HistologicaI Changes, Cytochrome Oxidase Activity and Copper Level in the Brain of the Postnatal Brindled Mouse

Neuropathological and enzyme‐histochemical studies were performed on brindled mouse hemizygotes (BMs) and normal littermates at the age of 2 days, 7 days, 11 days and 14 days, together with an investigation of their tissue cop per levels. A greatly increased copper concentration was confirmed in the kidney and intestine and a greatly reduced concentration in the liver and brain of BMs. The copper concentration in the brain increased gradually with age in the normal littermates, whereas this did not occur in BMs. There was no significant difference in the tissue copper concentration between the cerebrum and the cerebellum brainstem in BMs or in normal littermates. Light and electron microscopy of the BM brain revealed progressive neuronal degeneration in association with increased mito‐chondrial changes (ballooning and crista disintegration). Enzyme histochemical examinations demonstrated a progressive comparative decrease (i.e., an increased difference from normal) of cytochrome oxidase activity in the BM brain. These data suggest that progressive degeneration of the brain in Menkes’disease is attributable to mitochon‐drial degeneration caused by a comparative decrease of both copper concentration and cytochrome oxidase activity in the brain.

Estimation of energy expenditure by heart rate. Application to apple working days.

エネルギー消費量の算定法としては従来, RMR法が用いられてきたが, 近年, 携帯用24時間心拍数記憶装置が開発されたことにより, 心拍数を用いるエネルギー消費量算定方法が試みられている。その一方法としてHR-VO2法がある。そこでリンゴ栽培従事者を対象とし, 勢定, 摘花, 摘果, 袋かけおよび収穫に従事した1労働日の24時間心拍数記録をもとに, エネルギー消費量をHR-VO2法で推定し, 一部についてはRMR法と比較してHR-VO2法の有用性を検討した。24時間心拍記録からみた作業中の心拍数水準は, 摘花, 摘果, 袋かけ等では90～100拍, 収穫でも110拍前後にとどまっており, Rodahlの作業強度分類では“moderate work”のレベルに該当した。また, 同じ作業でも, 午前に比べて午後の心拍水準が低下する傾向を示し, 心拍数の日周期リズムとは異なる挙動を示した。HR-VO2法で算定した各労働日のエネルギー消費量は, RMR法による報告値と比べほぼ妥当な値と思われた。収穫作業日の一例について, HR-VO2法とRMR法による消費エネルギー量を比較すると, 前者は2,654kcalで後者より376kcal (16.5%) 高かった。作業動作別エネルギー消費量について, 両者の相関関係をみるとr=0.987 (p 袋かけ≒摘花>摘果>剪定の順序であった。収穫は日本人の栄養所要量で示された生活活動強度IV (重い) に該当し, 春季農繁期の管理作業日は同じ強度III (やや高い) に該当した。したがって, HR-VO2法によるエネルギー消費量推定法は, 若干の問題点はあるものの, 生体の代謝水準を比較的正確に反映する方法であり, その簡便性と相まって, 今後, RMR法に代わって導入されることが望ましいと考えられる。

Studies on the Amount of Exposure to Pesticides and Blood Levels of Organophosphorus Pesticides of Farmers Engaging in Joint Control Works over Apple Orchards

The concentration of pesticide that was inspired by speed sprayer (SS) operatorsin spraying a low toxic organophosphorus pesticide (800-fold to 1000-fold dilutions of wettable agent) were measured by the impinger-one respirator-per man measuring system. The mean ± standard error was 0.01116 ± 0.00191 mg/m3.The operators were made to perform the spraying task every day, and the organophosphorus pesticide concentration in the serum was gas-chromatographically measured before and after the task on each day. The maximum concentration after daily task was 0.032μg/2ml in an operator, and 0.061μg/2ml in anassistant. The concentration was already trace or undetectable in many of them the following morning. No apparent tendency for the pesticide to be accumulated was observed even in the operators after spraying the pesticide for 2 consecutivedays.The 24-hour urine was collected from each subject to measure the outputof PNMC (p-nitro-m-crezol). The output tended to be greater in the assistants than in the operators. This finding may be attributed to the fact that the assistants are trasiently exposed to high concentrations of the pesticide in powder form.

MECHANIZATION OF BUSH CUTTING AND FATIGUE OF THE WORKERS

In the mechanization of industrial work, it is nor desirable hygienically that the mechanization increases not only the work output, but also the physical and mental loads on the workers. Based on this, studies were made on the work performance and fatigue of two groups (A and B) of the workers, engaged in afforestation, one cutting the bush with the reaping hook and the other with the machine (bush cleaner). Results were as folows: 1. Daily consumption of energy was higher in Groups A than in B, amounting to 3840 Cals., and 3220 Cals. respectively. 2. In spite of the above date, weekly values of physiological tests such as flicker fusion frequency, visual near point, and threshold of knee reflex, underwent significantly greater variation in Group B than in A. 3. Tests with the first urine specimens in every morning showed a tendency in values of Donaggio reaction and uropepsin excretion, and of the others, indicating that Group B was significantly in more stressful condition than A. 4. Values of the above tests changed more greately in B than in A during daily working hours. 5. From the above results, the following two points was thought to be desirable; namely, one is to interpose a rational recess during the driving time of the machine, the other is to improve technically the machine weighing 15 kg and transmitting great vibrations to the bodies of the workers.