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Biomedical subjects

R Kawashima

Publications and source records attributed to R Kawashima.

At least 109 records · Page 6Linked to original sources
PubMed1993

Changes of regional cerebral blood flow during listening to an unfamiliar spoken language.

The regional cerebral blood flow (rCBF) was measured with positron emission tomography in eight normal volunteers with the purpose of measuring rCBF changes related to the comprehension of an unfamiliar spoken languages. When attempting to comprehend the meaning of words, the left hemisphere showed dominant increases in rCBF, however, when subjects attempted to evaluate the emotional tone of the same spoken passage, relatively large increases in rCBF more found in the right hemisphere. The results indicate that there may be several different auditory representations of language which involve both left and right hemispheres, both of which may contribute to the overall comprehension of spoken language.

Adolescent↗
PubMed1993

Regional cerebral blood flow changes of cortical motor areas and prefrontal areas in humans related to ipsilateral and contralateral hand movement.

The regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) in ten normal right-handed volunteers with the purpose of comparing rCBF changes related to movements of the dominant (right) and non-dominant (left) hand. The hand movement task consisted of sequential opposition of the thumb to each finger. The rCBF measured was compared with a rest state. Movements of the dominant hand and the non-dominant hand, increased CBF significantly in the contralateral motor area (MA) and the premotor area (PMA) with small increases in rCBF in the supplementary motor area (SMA). However, movements of the non-dominant hand also elicited significant ipsilateral increases in rCBF in the MA and PMA (6.3% and 5.0%, respectively). Superior part of the prefrontal area (PFA) of the left hemisphere showed significant CBF increases to both left and right hand movement. Our findings indicate that rCBF changes in the motor areas and the PFA of one hemisphere are not related simply to movement of the contralateral hand. Non-dominant hand movement may in addition require activation of ipsilateral motor areas. That is, there appears to be functional asymmetry in the MA and PFA in humans even in this relatively simple and symmetric motor task.

Adult↗
PubMed1993

Influence of dietary medium- and long-chain triglycerides on fat deposition and lipogenic enzyme activities in rats.

The present study investigates fat deposition, variances of fatty acid (FA) composition, and lipogenic enzyme activities through dietary medium- and long-chain triglyceride (MCT and LCT) supplementation in growing rats. Eighteen male Wistar rats were divided into three groups and fed isocalorically for 4 weeks with control (based on AIN 76), MCT (C8:0 26%), or LCT (corn oil 25%) diets. Compared to the control group with 0.28 +/- 0.01, feed efficiency was lower in the MCT rats and greater in the LCT rats (0.24 +/- 0.01 and 0.33 +/- 0.01, respectively). Weights of perirenal and epididymal adipose tissue pads of the MCT rats were similar to those of the control group, but were significantly lower than those of the LCT group. Whole-body carcass components data of MCT rats showed the decrease in moisture and protein contents compared to those of control and LCT rats. Fat content of LCT rats was 25-30% higher than those of the MCT and control group. Glucose-6-phosphate dehydrogenase, citrate cleavage enzyme, and malic enzyme activities of liver and epididymal adipose tissue were markedly low in LCT rats. In the MCT group, however, lipogenic enzyme activities were not suppressed, and malic enzyme activity was drastically increased. FA composition of whole-body triglycerides and epididymal adipose tissue in MCT rats showed that C16:0 and C16:1 levels were higher than those of the LCT rats. In contrast, FA composition of the LCT group presented high C18:2 content.(ABSTRACT TRUNCATED AT 250 WORDS)

ATP Citrate (pro-S)-Lyase↗
PubMed1993

[A case of marked eosinophilia in peripheral blood induced by rhGM-CSF].

A 53-year-old man underwent chemotherapy (CDDP, VDS, MMC) for treatment of lung cancer. He was given 125 micrograms/m2 of GM-CSF subcutaneously every day for 8 consecutive days, in order to prevent neutropenia. Three days after starting GM-CSF therapy, marked eosinophilia in peripheral blood was observed. The maximum eosinophil count was 89% of leukocytes. Nine days after stopping the treatment with GM-CSF, the number of eosinophils had normalized spontaneously. There were no clinical symptoms except for slight fever, up to 37.5 degrees C. Moreover, there was no relationship between the number of eosinophils and the serum levels of cytokines (IL-3, IL-5, GM-CSF), although we observed minimal but significant elevation of serum ECP level. This case indicates that GM-CSF may induce marked eosinophilia rather than widely stimulating granulocytes and monocytes.

Blood Proteins↗
PubMed1992

The influence of dietary medium and long chain triglycerides on growth performances and fat deposition in growing rats.

The present study was undertaken to investigate the effects of dietary medium and long chain triglycerides (MCT and LCT) on fat deposition and fatty acid composition of adipose tissues of rats. Twenty-seven Wistar strain male rats were divided into three groups and fed semisynthetic experimental diets: Basal (AIN 76), MCT (basal+C8:0 10%), LCT (basal+corn oil 10%). Feed intake was measured every day and body weight was measured once a week. At the beginning, 4th and 8th week of experimental feeding, 3, 12, 12 rats were slaughtered, respectively. Liver, perirenal and epididymal adipose tissue pads were weighted and their fatty acid composition was determined. Chemical composition of wholebody carcass was measured. Body weight gain was greater in rats fed the LCT diet than in rats fed the basal and MCT diets. Feed intakes were decreased in rats fed the MCT and LCT diets compared to that of the basal group. Subsequently, when compared to the basal group rats, feed efficiencies in rats fed the MCT and LCT diets were improved at the level of 6 and 14% for 4 weeks, and then 17 and 24% for 8 weeks, respectively. The weight of perirenal and epididymal adipose tissue pads tended to be larger in rats fed the MCT and LCT diets than in the basal group, although not significant. There were not significant differences in wholebody composition among the three groups. But it appeared that in rats fed the MCT diet, moisture content tended to be decreased and crude protein content increased compared to the LCT group rats. Fatty acid composition of the rats fed the LCT diet showed a good reflection of dietary fatty acid composition. Unlike LCT, little of medium chain fatty acid (MCFA) itself were incorporated into liver or adipose tissues. However, it seems that fat deposition of the MCT group was accomplished not by incorporation of dietary fatty acids but by de novo fatty acids synthesis.

Adipose Tissue↗
PubMed1992

Preparation for reaching: a PET study of the participating structures in the human brain.

The regional cerebral blood flow (rCBF) was measured as an indicator of regional metabolic activity with positron emission tomography (PET) in eight subjects who, after seeing a screen with seven targets prepared themselves with their eyes closed to reach these targets. The preparation phase was associated with increases of rCBF in the prefrontal cortex, several remote visual association areas in the parietal lobe, the supramarginal gyrus, the ventrolateral thalamus and the cerebellar vermis. During the course of learning the activations in the parietal visual areas, the supramarginal gyrus and the prefrontal cortex prevailed as a sign of the visual spatial information; its transformation being kept in working memory. The other activations vanished. No activations were seen in the motor cortices, indicating that reaching is a task which does not require substantial preparatory activity of motor cortices prior to the go signal.

Adult↗
PubMed1991

Protein deficiency suppresses bone resorption in sheep based on a short-term in vivo bone model.

Six sheep were fed protein-deficient and control diets for 40 d for each diet in a crossover design. Each sheep was intramuscularly injected with 120 pmol.d-1.kg body wt-1 of 1,25-dihydroxycholecalciferol during the last 7 d of each dietary period. Approximately 100 mg of bone powder was implanted on the abdominal muscle on d 21 and d 28 of each dietary period. Plaques induced by the bone powder were harvested 12 d after the implantation. Tartrate-resistant acid phosphatase (TR-ACP) activity was lower and the number of multinucleated cells was smaller in plaques of animals during the protein-deficient period than during the control period. The administration of 1,25-dihydroxycholecalciferol increased the activity of TR-ACP and the number of multinucleated cells during both dietary treatments. However, TR-ACP activity was still lower and the cell number was still smaller during the protein-deficient period than during the control period when they were injected with 1,25-dihydroxycholecalciferol. These results suggest that protein deficiency reduces the activity of osteoclastic cell induction. The suppressive effect of protein deficiency on the induction and the activity of osteoclastic cells is not related to the action of 1,25-dihydroxycholecalciferol.

Animals↗
PubMed1990

Effect of thyroxine injection on bone growth in energy deficient rats.

We investigated the role of thyroxine on bone growth in energy deficient rats. Rats were fed a normal diet and injected with saline, or a low-energy diet and injected with saline or 0.1, 1, or 5 micrograms/100 g BW of thyroxine for 22 days. Thyroxine injections decreased body weight gain but did not affect bone length and width. The epiphyseal growth plate was thinner and the activities of bone alkaline and acid phosphatase in energy deficient and 5 micrograms/100 g BW thyroxine injected animals were lower than that of the other treatment groups. Serum total thyroxine and triiodothyronine concentrations were increased but somatomedin C concentration was decreased by injecting with 5 micrograms/100 g BW of thyroxine in energy deficient rats.

Acid Phosphatase↗
PubMed1990

Effects of a high protein diet on bone formation and calcium metabolism in rats.

The effects of a high protein diet on bone formation and calcium (Ca) metabolism were evaluated in rats using an ectopic endochondral bone induction model. A control diet (18% casein) or a high protein diet (18% casein + 20% lactalbumin) was given to 50-day-old rats. Ten days after the feeding of the experimental diet, rats were intramuscularly implanted with demineralized bone powder (day 0). On day 14 and day 21, the implanted bone powder was harvested, and blood and urine samples were also obtained. Urinary Ca excretion was not increased on day 12-14; however, it was elevated on day 19-21 in rats fed the high protein diet compared with rats fed the control diet. The high protein diet remarkably stimulated urinary sulfate excretion in both sampling periods, which reflected dietary sulfur-containing amino acids contents. Also, rats fed the high protein diet exhibited a decrease in serum Ca concentrations. There was little difference in Ca contents and the activities of alkaline phosphatase and acid phosphatase in the implants between control group and high protein diet group on day 14 and day 21. Histological examination in the implanted demineralized bone powder on day 14 indicated only cartilage in rats fed the high protein diet in contrast to the occurrences of osteogenesis and remodeling in those fed the control diet. Retarded bone formation in rats fed the high protein diet might be owing to, in part at least, a restricted amount of Ca utilized at the stage of cartilage calcification.

Acid Phosphatase↗
PubMed1990

Effect of 1 alpha-hydroxycholecalciferol administration on Mg metabolism in sheep.

The effect of 1 alpha-hydroxycholecalciferol (1 alpha-OH-D3) administration on Mg metabolism in sheep was studied. Three wethers were intramuscularly injected with 0.2 microgram/kg body weight of 1 alpha-OH-D3 for 3 days. Plasma Mg concentration was decreased and plasma Ca concentration was increased by 1 alpha-OH-D3 administration. However, the duration of hypomagnesemia was shorter than that of the increment in the plasma Ca concentration. The administration of 1 alpha-OH-D3 increased apparent Ca absorption and urinary Ca excretion. However, apparent absorption and urinary excretion of Mg was not changed by 1 alpha-OH-D3 administration. The amount of glomerular filtrated Mg was reduced concomitantly with the reduction of plasma Mg concentration and glomerular filtration rate when 1 alpha-OH-D3 was injected. The tubular reabsorption of Mg tended to be suppressed and the ratio of reabsorbed to filtrated Mg was significantly lowered by 1 alpha-OH-D3 administration. These results suggested that the stimulation of urinary Mg excretion might not be one of the major factors inducing hypomagnesemia although 1 alpha-OH-D3 suppressed reabsorption of Mg in the renal tubule.

Absorption↗
PubMed1989

Kinetic evaluation of 11C-1-aminocyclopentane carboxylic acid in rabbits bearing VX-2 tumors using positron emission tomography.

Tumor detection with 11C-1-aminocyclopentane carboxylic acid (11C-ACPC) showed that this amino acid has a high affinity for malignant tumors. We studied the kinetics of intravenously injected 11C-ACPC in the rabbit VX-2 tumor using positron emission tomography. Three female rabbits bearing VX-2 tumor in the thighs were used. High uptake of 11C-ACPC was seen in the tumor and liver. 11C-ACPC in plasma decreased rapidly after injection and its activity in the tumor increased with time. The kinetic evaluation of ACPC uptake into the tumor was performed using the unidirectional transport model. The average values of the transfer constant of 11C-ACPC for VX-2 tumor were 0.030 +/- 0.002 ml/min/g. This preliminary result may form the basis for a quantitative analysis of the in vivo distribution of 11C-labeled ACPC in tumors.

Amino Acids↗
PubMed1989

Effects of high protein diet and sodium bicarbonate supplementation on calcium metabolism in rats.

This study was conducted to determine the effect of a high protein diet on calcium metabolism in rat. Wistar strain male rats (50 days old) were divided into 5 groups (day 0): control diet (18% casein); high protein diet (18% casein +20% lactalbumin); high protein and 0.1% sodium bicarbonate diet; high protein and 0.2% sodium bicarbonate diet; and high protein and 0.4% sodium bicarbonate diet. On days 0, 1, 3, 5, 7, 9, urine samples were collected and, at the same time, feces were collected from half of the animals in each group. Urinary titratable acidity (TA-HCO3-), ammonium ion (NH4+), and net acid excretion (NAE) were measured as an index of acid-base balance in rat body. Urinary volume was rapidly increased and the increase of urinary volume continued throughout the study in rats fed the high protein diet. Urinary excretions of calcium and phosphorus were increased after day 3 and day 1, respectively, in rats fed the high protein diet. The high protein diet depressed calcium absorption and elevated phosphorus absorption from the digestive tract in rats fed the high protein diet. The high protein diet decreased TA-HCO3-, which was closely correlated with the decrease of NAE. Sodium bicarbonate supplementation to the high protein diet had little effect on urinary calcium excretion and NAE. This study suggested that there was no relationship between metabolic acidosis and hypercalciuria in rats fed the high protein diet.

Acidosis↗
PubMed1987

Effect of thyroxine injection on bone growth in malnourished rats at different growth stages.

This study investigated the role of thyroxine on bone growth by injecting it into malnourished weaned and suckling rats. Weaned rats were fed a normal diet or a low-protein, low-energy diet, and injected with saline or thyroxine (5 micrograms/100 g BW) for 22 days. Suckling pups were injected with saline or 2 micrograms of thyroxine, and reared by dams fed a normal diet or a low-protein diet for 15 days. Thyroxine injection decreased body weight gain in both growth stages. Bone length, width and weight were not affected by thyroxine injection in weaned rats. Thyroxine injection increased femur length and tail growth, but did not change bone width in suckling rats. The epiphyseal growth plate and zone of hypertrophic cartilage cells were thinner in malnourished rats than in normal rats at both growth stages, but the number of proliferating chondrocytes was greater in suckling rats that received thyroxine injections than in those that received saline injections. The disappearance of trabeculae was observed in both normal and malnourished weaned rats upon thyroxine injection. These results suggested that retarded bone growth due to malnutrition might be independent of thyroid function in both growth stages.

Animals↗
PubMed1985

Hexestrol residues and metabolites in the tissues of wethers injected with hexestrol dicaprylate or hexestrol.

Four young (23 kg body weight) and two mature wethers (52 and 92 kg body weight) were subcutaneously injected with hexestrol (HX) or HX dicaprylate (HX-D) and killed 41 d later. The HX residues, comprising free, glucuronide and KOH hydrolyzable forms plus metabolites were determined by gas chromatography after liquid-liquid extraction and silica gel chromatographic purification of tissue sample. The HX residues were observed to be at concentrations of .1 to 1.0 ppb in most of the tissues examined. Maturity of the animals and the two hormonal formulations resulted in little difference in residues. The KOH hydrolyzable fraction was hardly detected in the tissues examined. Free HX was a major residue in muscle, representing about 70% of HX residues. Glucuronide HX represented 70 to 80% of HX residues in liver and kidney. In lung, glucuronide and free HX were present in similar amounts. This study showed that the gross metabolic patterns of HX and its esters are similar to other estrogens and steroids.

Animals↗
PubMed1985

The influence of protein and/or energy deficiency on the growth of long bone in rats.

The effects of protein and/or energy deficiency on long bone growth were studied using rats of an average weight 100g. Four groups of Wistar rats were respectively fed on a normal diet, a low-energy diet, a low protein-diet, and a low-protein and low-energy diet for 45 days. Both energy and protein deficiency restricted gains of body weight and femur length and the activity of alkaline phosphatase in the tibia to the same extent. The epiphyseal growth plates of the femur in protein-deficient rats were as thin as those in energy-deficient rats. On the other hand, femur width and activity of acid phosphatase in the tibia were lower in protein-deficient animals than those in energy-deficient ones. Serum calcium concentrations and calcium content of bone were the same among all groups.

Acid Phosphatase↗