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R Kawashima

Publications and source records attributed to R Kawashima.

125 records · Page 7Linked to original sources
PubMed1984

Effect of calcitonin on salivary phosphorus and calcium excretion in sheep.

Three thyroidectomized sheep were infused intravenously with porcine calcitonin at a rate of 30 mi.u./h per kg and three sham-operated sheep were infused with vehicle for 5 h. Saliva was collected from the left parotid duct by cannulation for 10 min in every hour. Salivary secretion rates were not changed in either thyroidectomized or sham-operated sheep throughout the experiment. Before the infusion, salivary phosphorus excretion was less in thyroidectomized sheep than in sham-operated animals. Calcitonin infusion increased salivary phosphorus excretion and decreased serum phosphorus concentrations in thyroidectomized sheep. Vehicle infusion did not affect salivary phosphorus excretion in sham-operated sheep. Serum concentrations and salivary excretion of calcium were decreased by calcitonin infusion into thyroidectomized sheep but were not changed in sham-operated sheep infused with vehicle. Calcitonin infusion increased serum parathyroid hormone concentrations in thyroidectomized sheep after the decrease of serum calcium concentrations. However, vehicle infusion did not affect serum parathyroid hormone concentrations in sham-operated sheep. There was little change of cyclic AMP excretion during the experiment in either thyroidectomized or sham-operated sheep. It is concluded that calcitonin increases salivary phosphorus excretion in sheep.

Animals↗
PubMed1984

Effects of intravenous glucose or epinephrine injection on plasma concentrations of potassium, magnesium and insulin in sheep.

The experiment was conducted to study the relationships among glucose, insulin, potassium, magnesium and calcium concentrations in the blood plasma following intravenous glucose or epinephrine injection. Plasma concentrations of potassium and magnesium were lowered after the respective injection of glucose and epinephrine. When compared to epinephrine injection, an injection of glucose solution decreased potassium and magnesium concentrations in plasma more rapidly. Moreover, the recovery of the concentration levels of these minerals was faster when the animals were injected with glucose rather than epinephrine. These changes were inversely related to those of plasma insulin concentrations. The results may indicate that increased insulin secretion caused by glucose or epinephrine injection results in decreases of the plasma magnesium as well as potassium concentration in sheep.

Animals↗
PubMed1983

Suppressive effect of calcitonin on intestinal absorption of calcium and phosphorus in sheep.

This study was carried out to determine the effect of calcitonin on calcium and phosphorus absorption in sheep. Six sheep, which were prepared with a carotid loop and a portal venous catheter, were used. Thyroidectomized sheep were injected intramuscularly with porcine calcitonin at feeding time. Serum calcium concentrations did not change in intact or thyroidectomized sheep after feeding but calcium venoarterial blood differences in thyroidectomized sheep were higher than in intact sheep 8 h after feeding. Serum calcium concentrations and calcium veno-arterial blood differences were decreased by calcitonin injection into thyroidectomized sheep. Calcitonin injection also reduced the serum phosphorus concentrations. Phosphorus veno-arterial blood differences in thyroidectomized sheep were much less than in intact sheep before feeding although the blood differences were not affected by calcitonin injection in thyroidectomized sheep. The results indicated that calcitonin decreased calcium absorption, which caused a reduction in the serum calcium concentrations, and that calcitonin injection did not affect phosphorus absorption in thyroidectomized sheep.

Animals↗
PubMed1981

Specific cytosol binding proteins for 25(OH)D3 and 1.25(OH)2D3 in human breast cancers.

Binding proteins for 1.25 (OH) 2D3 were investigated in thirty breast cancers. Human breast cancer was shown to contain specific, high affinity cytosol binding proteins for 1.25 (OH) 2D3 and 25 (OH) D3. The binding protein for 1.25 (OH) 2D3 sedimented at 3.7 S and the binding protein for 25 (OH) D3 at about 6.0 S on sucrose density gradient analysis containing 0.3 M KCl and 1 mM dithiothreitol in buffer. Kd for 1.25 (OH) 2D3 were from 0.1 x 10(-11) M to 7.1 x 10(-11) M measured by Scatchard plots. Competition binding studies indicated that the relative specificity of the binding protein for 1.25 (OH) 2D3 much greater than 25 (OH) D3 greater than 1 alpha (OH) D3, 24,25 (OH)2D3 greater than D3 much greater than Estradiol-17 beta. 1.25 (OH) 2D3 receptor-positive was detected in twenty-eight out of thirty breast cancers.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

Gas-liquid chromatographic determination of hexestrol residues in adipose tissue.

A gas-liquid chromatographic (GLC) method is described for determining hexestrol residues in adipose tissue. The extraction and purification procedures were based on a published method for determining diethylstilbestrol. To increase precision and sensitivity, the sample was further cleaned up by silica gel column chromatography. The heptafluorobutyric (HFB) derivative of hexestrol was used for GLC analysis with HFB-docosanol as an internal standard. A variety of acetone-benzene mixtures were compared to determine the optimum ratio for hexestrol acylation. Acetone-benzene (90 + 10) or 100% acetone provided 16% higher GLC response than did a 50 + 50 mixture (P less than 0.001) and was selected for use in the acylation procedure. A system for evaporating excess reagents was also studied. Overall percent recovery reached 72 +/- 5. The method can be used to determine residual hexestrol at the 0.1 ppb level.

Acylation↗
PubMed1981

Immunoglobulin G heavy-chain allotypes as possible genetic markers for human cancer.

Serum samples from 343 unrelated, healthy Japanese, 194 hepatitis B surface antigen (HBsAg)-positive healthy carriers, 96 patients with primary hepatoma, 91 patients with lung cancer, 94 patients with breast cancer, and 87 patients with gastric cancer were examined for IgG heavy-chain allotypes (Gm). The Gm phenotypes of the sera from patients with breast cancer exhibited a distribution similar to that of the normal controls. However, compared to that of normal controls, the Gm phenotype (1,2,21,13,15,16) was significantly increased in the patients with primary hepatoma(chi 2 (1) = 15.12, corrected P less than 0.01) and in the patients with lung cancer (chi 2 (1) = 10.97, corrected P less than 0.05). Compared to that of normal controls, the haplotype Gm 1,2,21 was significantly increased in the patients with primary hepatoma (chi 2 (1) = 22.34, corrected P less than 0.01). Increased frequency of Gm 1,2,21 in primary hepatoma was also significant compared to that of HBsAg-positive healthy carriers (chi 2 (1) = 9.25, corrected P less than 0.05).

Genetic Markers↗
PubMed1978

Modified method for electron capture gas-liquid chromatographic determination of hexestrol residues in bovine tissues.

A gas-liquid chromatographic (GLC) method with electron capture detection was developed for determining hexestrol residues based on a GLC method for diethylstilbestrol residues. The extraction and purification procedures were based on a published procedure. Pentafluoropropionic (PFP) and heptafluorobutyric (HFB) anhydrides and other halogenated compounds were compared as acylation reagents. PFP anhydride was selected because it provided reproducible GLC responses. Of the 3 column packing materials tested, OV-17, OV-210, and QF-1, OV-17 was the most stable under the GLC conditions used. A pH 10.5--10.6 in the purification step gave higher recoveries than pH 10.3 or pH 10.8 and was selected for use. The method is suitable for determining residues of 0.5 ppb. The limit of sensitivity ranges from 0.1 to 0.2 ppb.

Animals↗
PubMed1977

Effects of thiamine administration on blood lactic and concentration and mineral metabolism in sheep.

The object of the present experiment is to determine the effect of thiamine administration on lactic acid concentration in blood plasma and the mineral metabolism in sheep given low and high concentrate rations. A high concentrate ration containing 90% concentrate and 10% roughage was fed to one group of sheep and a low concentrate ration containing 60% concentrate was given to the other group. Thiamine was intramuscularly injected into every sheep at a level of 50 mg of thiamine tetrahydrofurfuryl disulfide per day. No great difference was found in the plasma lactic acid concentration between the animals fed the low and high concentrate rations, and those between the control and thiamine injection periods. Thiamine injection appeared to increase urine and fecal magnesium excretion and significantly decreased magnesium balance (p less than 0.05). It may be conceivable that endogenous magnesium excretion is enhanced by thiamine administration in sheep.

Animals↗
PubMedDate not supplied

Functional anatomy of reaching and visuomotor learning: a positron emission tomography study.

The purpose of this study was to identify the functional cortical fields involved in reaching for targets in extrapersonal space, and to identify the specific fields representing visual target information in long-term memory. Ten healthy subjects were asked to learn the positions of seven circular targets that were repeatedly projected on a screen. The regional cerebral blood flow was measured with positron emission tomography during a rest state, at an early learning stage, at a later learning stage, and finally at 30 min after the course of learning had been completed. Mean rCBF change images for each task minus rest were calculated and fields of significant rCBF changes were identified. In all three task states, cortical fields were consistently activated in the left motor and premotor areas, the posterior part of the superior parietal lobule, and the right angular gyrus. When learning of the target positions had been achieved, additional fields appeared bilaterally in the posterior part of the superior parietal lobule, the right superior occipital gyrus, the left motor and premotor areas, the medial aspect of the superior frontal gyrus, the postcentral gyrus, the superior part of the cuneus, the inferior part of the angular gyrus, and the anterior part of the insula. The results indicate that there are at least two different types of functional fields in the posterior part of the superior parietal lobule; one is active during reaching for the targets when guided by internal representations of target positions; the other likely represents the storage sites of visual target information that is addressed in long-term memory.

Adolescent↗
PubMedDate not supplied

A four-dimensional probabilistic atlas of the human brain.

The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons between the ages of 18 and 90 years. Given the presumed large but previously unquantified degree of structural and functional variance among normal persons in the human population, the basis for this atlas and reference system is probabilistic. Through the efforts of the International Consortium for Brain Mapping (ICBM), 7,000 subjects will be included in the initial phase of database and atlas development. For each subject, detailed demographic, clinical, behavioral, and imaging information is being collected. In addition, 5,800 subjects will contribute DNA for the purpose of determining genotype- phenotype-behavioral correlations. The process of developing the strategies, algorithms, data collection methods, validation approaches, database structures, and distribution of results is described in this report. Examples of applications of the approach are described for the normal brain in both adults and children as well as in patients with schizophrenia. This project should provide new insights into the relationship between microscopic and macroscopic structure and function in the human brain and should have important implications in basic neuroscience, clinical diagnostics, and cerebral disorders.

Adolescent↗
PubMedDate not supplied

In vivo effects of apoptosis in asthma examined by a murine model.

BACKGROUND: One of the characteristic features of bronchial asthma is the accumulation of various inflammatory cells, predominantly eosinophils, at the subepithelial region beneath the basement membrane of the airway. Apoptosis is a form of physiological cell death, through which the cellular contents including biologically active substances are kept in the cell membrane and are removed without their harmful effects. So, attempts were made to clarify whether the induction of apoptosis is beneficial in asthma by using a murine model with ovalbumin (OA) as responsible allergen. METHODS: A/J mice, which are genetically predisposed to be hyperresponsive to acetylcholine, were immunized with OA and alum, accompanied by OA inhalation for 2 weeks, during which some of the mice were also treated with either anti-Fas monoclonal antibody or sham control hamster IgG intranasally. Airway responsiveness to acetylcholine was then analyzed by measuring airway resistance with a body plethysmograph box. Apoptosis was assessed by propidium iodide and TUNEL staining. RESULTS: Inhalation of OA increased both airway responsiveness to acetylcholine and the number of cells, mostly eosinophils, infiltrated into the airway. Administration of anti-Fas antibody induced apoptosis in the infiltrated eosinophils and abolished augmentation of airway hyperresponsiveness caused by OA inhalation. CONCLUSION: Induction of apoptosis in proinflammatory cells including eosinophils at the airway may have a beneficial effect on suppressing airway hyperresponsiveness.

Acetylcholine↗
PubMedDate not supplied

Apoptosis in normal tissues induced by anti-cancer drugs.

To investigate the damage mediated by anti-cancer drugs in normal cells, we examined the effect of such drugs on apoptosis of normal cells of the small intestinal epithelium and the bone marrow by in situ DNA end-labelling and transmission electron microscopy. Mice received a single dose of 5-fluorouracil (5-FU) or cisplatin, or repeated daily doses of 5-FU for 7 days. In mice treated with a single dose of 5-FU 50 mg/kg or cisplatin 5 mg/kg, the number of apoptotic cells appearing in the small intestine 12 h after injection was relatively small, but increased steadily reaching a peak after 36 h and then decreasing to close to that in the control group by 48 h. In bone marrow cells, results were similar in mice treated with single doses of 5-FU 50 mg/kg but apoptosis increased much less in those treated with cisplatin 5 mg/kg. The proportion of apoptotic cells reached peak values earlier at higher concentrations of 5-FU or cisplatin both in small intestine and in bone marrow. In the mice treated repeatedly with 5-FU 50 mg/kg, the proportion of apoptotic small intestinal epithelial cells reached a succession of peaks at 48-h intervals. Mice treated repeatedly with 5-FU 50 mg/kg also showed a rapid increase in diarrhoea symptoms and a steady decrease in the height of villi. Our results suggest it may be possible to prevent the side-effects of anti-cancer drugs by inhibiting apoptosis in the gastrointestinal tract.

Animals↗
PubMedDate not supplied

Functional organization of the human primary motor area: an update on current concepts.

Studies on the functional mapping of the human primary motor cortex (MI) are reviewed. In human subjects, the MI has been generally recognized as the cortical executive locus for all voluntary movements. However, some investigators have reported that activity in the MI is related to ipsilateral distal limb movements, and that the MI hand area contains subregions which are related to preparatory activity and subregions which change their activity with the learning of new motor skills. These recent findings challenge the traditional concepts of the functional role of the MI.

Brain Mapping↗