Kumiko Ogoshi

Magnetic resonance imaging shows delayed ischemic striatal neurodegeneration.

Brief focal ischemia leading to temporary neurological deficits induces delayed hyperintensity on T1‐weighted magnetic resonance imaging (MRI) in the striatum of humans and rats. The T1 hyperintensity may stem from biochemical alterations including manganese (Mn) accumulation after ischemia. To clarify the significance of this MRI modification, we investigated the changes in the dorsolateral striatum of rats from 4 hours through 16 weeks after a 15‐minute period of middle cerebral artery occlusion (MCAO), for MRI changes, Mn concentration, neuronal number, reactivities of astrocytes and microglia/macrophages, mitochondrial Mn‐superoxide dismutase (Mn‐SOD), glutamine synthetase (GS), and amyloid precursor protein. The cognitive and behavioral studies were performed in patients and rats and compared with striatal T1 hyperintensity to show whether alteration in brain function correlated with MRI and histological changes. The T1‐weighted MRI signal intensity of the dorsolateral striatum increased from 5 days to 4 weeks after 15‐minute MCAO, and subsequently decreased until 16 weeks. The Mn concentration of the dorsolateral striatum increased after ischemia in concert with induction of Mn‐SOD and GS in reactive astrocytes. The neuronal survival ratio in the dorsolateral striatum decreased significantly from 4 hours through 16 weeks, accompanied by extracellular amyloid precursor protein accumulation and chronic glial/inflammatory responses. The patients and rats with neuroradiological striatal degeneration had late‐onset cognitive and/or behavioral declines after brief focal ischemia. This study suggests that (1) the hyperintensity on T1‐weighted MRI after mild ischemia may involve tissue Mn accumulation accompanied by Mn‐SOD and GS induction in reactive astrocytes, (2) the MRI changes correspond to striatal neurodegeneration with a chronic inflammatory response and signs of oxidative stress, and (3) the subjects with these MRI changes are at risk for showing a late impairment of brain function even though the transient ischemia is followed by total neurological recovery. Ann Neurol 2003;54:732–747

Decrease in bone strength of cadmium-treated young and old rats

A decrease in mechanical strength of bones was observed both in young and old rats for long periods of administration of cadmium. Young (3-week-old) female rats were given 0 (control), 5 and 10 ppm cadmium in drinking water, respectively, for 20 weeks. Old (18-month old) female rats were given 0 (control) and 40 ppm cadmium in drinking water, respectively, for 7 months. The compression strengths of bones of young rats which were given 10 ppm cadmium, and those of old rats which were given 40 ppm cadmium, significantly decreased at the distal end portion of femur. Cadmium contents in bones in the 10 ppm and 40 ppm groups were about 110 and 210 ng/g dry weight, respectively. The present result confirmed that cadmium has a lesional effect on the mechanical strength of bone at the concentration of 100–200 ng/g in dry weight of bone, for both young and old rats.

Decrease in the mechanical strength of bones of rats administered cadmium

The mechanical properties of the bones of young, adult and old rats administered various concentrations of cadmium were measured to prove the direct effect of cadmium on the bones of young rats. The young rats were divided into three subgroups, which were administered 0 (control), 5 and 10 ppm cadmium, respectively. The adult rats were subdivided into six groups, administered 0, 10, 20, 40, 80 and 160 ppm cadmium, respectively. The old rats were divided into three subgroups, which were administered 0, 80, and 160 ppm cadmium, respectively. The length of the administration was 4 weeks in every group. The decrease in the mechanical strengths of bones of young rats administered with cadmium was observed. On the other hand, no change in mechanical strength of bones was observed in the case of adult and old rats, administered up to 160 ppm cadmium. The correlation between the cadmium in bones and the decrease in the strength of the bone shows that cadmium directly affects the mechanical properties of bones of young rats.

Decrease in compressive strength of the femoral bone in rats administered stannous chloride for a short period

Abstract The compressive strength of the entire femur of each rat, which was administered 0, 50, 150, 300, or 600 ppm of tin in the form of stannous chloride in drinking water, and commercial laboratory chow (contaminated with 52.4 ppm of tin) for 4 weeks, was measured in an Instron machine. The distal epiphysial compressive strength decreased significantly in the groups administered more than 300 ppm of tin. The present study demonstrates that inorganic tin has a toxic effect on the bone and suggests that the safe levels of tin is much lower than ever reported.

Did Arsenic Contamination in the Inagawa River Occur in Geogenic Relation to the Great Hanshin (Kobe) Earthquake of 1995

Arsenic contamination in river and ground water was investigated in the Inagawa area of Kansai district, Japan, from August to October, 1995. Arsenic has been continually detected at a level about 2 times higher than the environmental standard in the two tributaries of the Inagawa River, i.e. the Kimo and the Shio Rivers. The arsenic contamination was probably caused by the topographical change after the Great Hanshin Earthquake.

Nutritional status of people living in Dzong village, in the northern mountainous area of Nepal.

A nutritional survey was carried out among residents (39 males and 46 females) of Dzong village in the northern area of the Gandaki region of Nepal. The results were compared with our previous findings. The mean body mass index value was under 21 for both sexes, but the mean percentage of body fat of females (17-19 years old, 25.8 +/- 9.4%; 20-29 years old, 31.0 +/- 8.4%) was higher than that of males (17-19 years old, 12.0 +/- 1.0%; 50-59 years old, 24.4 +/- 7.6%). Most serum nutritional markers for both sexes were generally at normal levels although the iron levels were lower and packed red cell volume levels were higher than normal. As determined by results of the 24-hr dietary recall survey, the main food groups consumed by both sexes were cereals, potatoes, pulses, meats and vegetables. The mean daily intake of nutrients was similar for both sexes, with a few exceptions. The relatively high serum TG levels of the subjects may have been due to the high consumption of carbohydrate-laden cereals. The amounts of food consumed were not adequate, resulting in a latent and chronic deficiency of nutrients, especially calcium and iron. These results suggest that improvements in the nutritional status of this group of people are necessary.

Food consumption and serum nutritional status of people living in the Kathmandu valley in Nepal

ObjectiveThe food consumption and serum nutritional status of people living in the Kathmandu valley, Nepal, were examined to obtain actual data for comparison with our previous findings.MethodsA dietary survey of 45 males and 60 females was carried out in March 1997 by the 24-hr dietary recall method and nutrient intake was calculated from food tables of India and Japan. Fasting venous blood samples were obtained and serum biochemical parameters were measured using clinical kits.ResultsThe mean body mass index values was at about the same level in both sexes, although the mean percentage body fat of females was higher than that of males, and vice versa for packed red cell volume. The main foods consumed by both sexes, were rice, potatoes, meats, milk & dairy products and vegetables, with a difference in the amounts consumed. Females did not drink alcoholic beverages. The mean daily intakes of energy, protein, lipids, iron and vitamin B group for the males were higher than those for the females, while those of vitamins A and C for the males were lower than those for the females. The mean values of serum biochemical parameters for both sexes were generally at the normal levels, but those of ALT and TG were at the higher end of the normal range. Differences of correlation between food groups and between serum parameters were observed depending on the sex, however, no clear relationship between food and nutrient intake and serum biochemical parameters were observed.ConclusionsThe present food intake study revealed that the amounts of food consumption for both sexes, especially for the females, were mostly insufficient although the serum parameters were at the normal levels. The energy intake of both sexes was lower than that of estimated requirements and those in Terai region. The relatively high serum TG level of the subjects may be due to the consumption of large amounts of cereals containing much carbohydrate. Our findings suggested a marked influence on food consumption by food price and income in spite of the easier food availability in the city, and also lack of knowledge about nutrients and health, thus there is need for improvement of the nutritional status of this group of people.

EFFECT OF CADMIUM ON BONES: STUDIES ON THE MECHANICAL STRENGTH OF RAT BONES AND THE ELECTRON PROBE MICRO-ANALYSIS

In our previous studies, it was shown that a small amount of cadmium, which was administered to young rats, decreased the mechanical strength of bones. But when adult rats were administered with a higher dose of cadmium, they accumulated far lower cadmium into bones and the decrease in the mechanical strength of bones did not occur. In the present study, we tested the mechanical strength of bones of young rats for a longer period of administration, and observed that the mechanical strength of bones constantly decreased. In order to explain how the accumulated cadmium in bones affects the weakening of the bones, we made electron probe microanalyses (EPMA) to find out the localization site of cadmium in bones and to analyse the change in the elements of bones.