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Biomedical subjects

H Tauchi

Publications and source records attributed to H Tauchi.

At least 55 records · Page 3Linked to original sources
PubMed1993

Cell cycle dependence for the induction of 6-thioguanine-resistant mutations: G2/M stage is distinctively sensitive to 252Cf neutrons but not to 60Co gamma-rays.

Cell cycle dependence for the induction of 6-thioguanine-resistant mutation was investigated using synchronized mouse L5178Y cells after exposure to 4 Gy to 60Co gamma-rays or 1 Gy of 252Cf radiation (fission neutrons). Maximal mutation frequency was observed immediately after release from colcemid block (G2/M phase) after 252Cf radiation, whereas it was 1 h after the release (G1 phase) after 60Co gamma-rays. When the mutation frequency was plotted against the surviving fraction, a general correlation was observed between the two parameters except for G2/M and G1 phases which were more mutable per lethal event for 252Cf and 60Co radiations, respectively.

Animals↗
PubMed1993

Age dependency of mitochondrial DNA decrease differs in different tissues of rat.

Mitochondrial DNA contents were measured using non-radioactive DNA probes for specific mtDNA sequences. The nuclear repetitive DNA sequence, LINE, was used as an internal standard marker. Age-dependent decreases in the mtDNA/nucDNA ratio in rat hepatic cells were confirmed with this method and, furthermore, a similar decrease was found in cardiac muscles. On the other hand, in thigh skeletal muscles such a decrease was not observed, slight increases being rather found in 18- to 24-month-old rats. The possible relationship of the decrease in mtDNA and the mechanism underlying animal senescence was discussed.

Aging↗
PubMed1993

Quantitative immunohistochemistry of parvalbumin expression in the rat diaphragm.

Parvalbumin is a calcium-binding protein involved in the mechanism of Ca++ exchange between sarcoplasmic reticulum and the myofibrils. This characteristic promotes a direct correlation between the amount of parvalbumin and the velocity of contraction-relaxation of skeletal muscle fibers. To quantify the expression of parvalbumin in the rat diaphragm, transverse paraffin sections of this muscle were processed immunohistochemically using antiparvalbumin monoclonal antibody. The stained sections were inspected on an image analysis device to evaluate the intensity of the immunoreaction and to make morphologic measurements of the muscle fibers. The immunoreaction intensity data allowed the division of fibers in fast- and slow-twitch types. The rat diaphragm was characterized as a fast-twitch muscle due to the presence of 59.8% of fast-twitch fibers. The fibers' lesser diameter values showed that the slow-twitch fibers had a small diameter as compared to the fast-twitch ones (P < .001). The method used suggests that immunohistochemistry for parvalbumin assisted by image analysis is a feasible technique to separate fast- and slow-twitch skeletal muscle fibers in paraffin sections and to characterize their morphologic profiles.

Animals↗
PubMed1992

Quantitation of changes in mitochondrial DNA during aging and regeneration of rat liver using non-radioactive DNA probes.

By using DNA probes prepared from cloned cells which contain mitochondrial DNA (mtDNA) sequences in plasmids, the specific detection of mtDNA became possible in the presence of large excess of nuclear DNA by DNA-DNA hybridization. For this purpose, we prepared mtDNA probes labeled with non-radioactive substrate, which allowed a wider possibility of application. This method revealed that the contents of mtDNA in rat liver are strikingly decreased during aging. Furthermore, it was observed that although mtDNA content increased upon partial hepatectomy even in old rats, it decreased to the pre-operation level rather rapidly within 1 week after reaching peak in regenerated liver.

Aging↗
PubMed1992

Effect of TPA, okadaic acid and 1 alpha,25-dihydroxyvitamin D3 on neoplastic transformation induced by 60Co gamma-rays or 252Cf fission neutrons in Balb/c 3T3 cells.

The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA), 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3] and okadaic acid were individually examined on the neoplastic transformation of Balb/c 3T3 cells which were exposed to either 60Co gamma-rays or 252Cf fission neutrons. The addition of 1 alpha,25(OH)2D3, or TPA, enhanced the transformation induced by gamma-rays or low doses of fission neutrons. No enhancement was observed by the addition of okadaic acid except at toxic concentrations (5 ng/ml) and with higher doses of radiation. Moreover, the enhancement of transformation by either 1 alpha,25(OH)2D3 or TPA decreased as the radiation dose was increased. The enhancement ratio, calculated by least-square analysis from 0 Gy to 1 Gy, was greater for 1 alpha,25(OH)2D3 than for TPA, and also greater for gamma-ray irradiation than for neutron irradiation. These results suggest that the promotion of radiation-induced transformation depends on the level of the initial damage caused by radiation; and that the differences in the enhancement properties of different chemicals may be due to different individual triggering mechanisms involved in the transformation process.

3T3 Cells↗
PubMed1992

[Immunohistochemical studies on S-100 beta positive structures in the human hippocampus in regard to age and morphological change of dementia].

The histological localization of S-100 beta protein in the hippocampus of human autopsy brains of 47 males (71-103 years old) and 90 females (56-104 years old) was studied immunohistochemically. Astrocytes and their processes were positively stained, but neuronal cells were not stained. However, Alzheimer's neurofibrillary tangle-like, senile plaque-like and fibrillary spindle figures were stained positively. S-100 beta positive structures increased in grade with age, but not always equally on Alzheimer's neurofibrillary tangles or senile plaques stained by Bodian method. Astrocytes decreased in number with age, and showed marked compensatory hypertrophy of their processes. S-100 beta positive structures seemed to be related to astroglial changes in terms of degeneration or loss of synapses.

Aged↗
PubMed1992

[The first case of infantile type neuronal ceroid-lipofuscinosis in Japan].

We reported the first case of typical infantile-type neuronal ceroid-lipofuscinosis (INCL) in Japan. The patient was a 1-year-old girl presenting with rapidly progressive psychomotor deterioration and blindness. Muscular hypotonia, microcephaly and myoclonic jerks became marked with the progression of her disease. Diminution in amplitude of EEG, VEP and ERG was prominent in the initial stage, but ABR was normal. MRI showed progressive brain atrophy. Electron microscopic examination of the biopsied skin revealed granular matrix, the specific inclusion bodies, in the epithelial cell of sweet glands. Many sea-blue histiocytes were demonstrated in her bone marrow samples. INCL is a common progressive encephalopathy in the Scandinavian countries, but a typical case had not yet been fully reported in Japan. This prompted us to report our case. Future reports are need for the study of INCL in Japan.

Biopsy↗
PubMed1992

[Pharmacokinetics and clinical studies of panipenem/betamipron in the pediatric field].

Panipenem/betamipron (PAPM/BP) is a mixture of panipenem (PAPM), carbapenem antibiotic, and betamipron (BP), N-benzoyl-beta-alanine. The adverse reaction to PAPM of the kidney is reduced by the addition of BP to PAPM which inhibits the anion transport in the kidney tubules. We studied the pharmacokinetics and the clinical efficacies of PAPM/BP in children and we evaluated the antibacterial activities of PAPM by determining MIC values of PAPM in vitro against organisms isolated in our children's hospital from January to December, 1990. 1. Pharmacokinetics 10 mg/kg of PAPM/BP (10 mg PAPM/10 mg BP) was administered intravenously by drip infusion to 7 children. The mean blood concentration of PAPM was 14.8 micrograms/ml at the peak, and the mean half life was 0.9 hours in blood. PAPM was not detected in blood 3 hours after the time when the peak values were attained. 2. Clinical studies 10 mg/kg of PAPM/BP was administered intravenously 3 times a day to 18 cases including 15 of respiratory infections, 2 of otitis media and 1 of sepsis. The clinical efficacies of PAPM/BP were excellent or good in 17 out of the 18 cases. All causative organisms isolated in 5 cases, Methicillin-sensitive Staphylococcus aureus (MSSA) (1 case), Streptococcus pneumoniae (1), Haemophilus influenzae (2) and Branhamella catarrhalis (1) were eradicated in a few days upon the administrations of PAPM/BP. No adverse reactions due to PAPM/BP were observed, but a slight elevation of platelet counts in blood was observed in 1 case, which was normalized soon after the end of the treatment. 3. Antibacterial activities in vitro(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1991

[Effectiveness of etoposide on reactive histiocytosis and refractory state to platelet transfusion during therapy of leukemia: case report].

The patient is 11-year-old girl who was diagnosed as having hybrid acute leukemia (myeloid and lymphoid) from morphological (cytochemistry) findings, immunophenotype and genotype. During reinduction therapy after a second relapse, she presented hepatosplenomegaly and the remittent fever unresponsive to the intensified antibiotics. The diagnosis of reactive histiocytosis was made because of the remarkable elevation of serum ferritin value and proliferation of mature histiocytes in the bone marrow. Treatment with etoposide resulted in the disappearance of her fever and other symptoms. The subsequent refractoriness to platelet transfusion was also overcome by etoposide (p.o.) therapy. The results suggested that the treatment with etoposide might be effective for reactive histiocytosis and the related refractory state to platelet transfusion during therapy for leukemia.

Blood Component Transfusion↗
PubMed1989

Age-related changes in brush border enzymes under different dietary conditions.

We examined the age-related changes of renal brush border enzymes of male Donryu rats under different dietary conditions. High protein diet (51% casein) markedly decreased the activity of renal leucine aminopeptidase as compared with low protein diet (8% casein). No significant difference, however, was observed in the activity of renal maltase between high and low protein diets. Alkaline phosphatase activity from young adult (3-month-old) rats in the high protein diet group was significantly lower than that in the low protein diet groups. From these results, it is inferred that dietary conditions affect the age-related alteration of renal brush border enzymes. Together with the previous results, it is suggested that proteins of renal brush borders are altered differently during the aging process.

Aging↗
PubMed1989

[Morphological studies of the hippocampus of 100 elderly females in relation to age and grade of dementia].

The number of the nerve cells, appearance of Alzheimer's neurofibrillary tangles and of senile plaques in the hippocampus of 100 female autopsy cases aged 56-101 were compared in relation to age and grade of dementia. The number of nerve cells of granular and pyramidal layers decreased significantly with age, however, the decrease in number did not necessarily correlate with the grade of dementia. Appearance of Alzheimer's neurofibrillary tangles was increased in grade with age and with grade of dementia of all types. Appearance of senile plaques increased in grade only in cases with dementia of Alzheimer's type, but not in case with cerebrovascular type of dementia.

Age Factors↗
PubMed1989

[Micromeasurement of autofluorescent granules of the human hippocampus and cerebellum in relation to age and grade of dementia].

The amount of autofluorescent granules of nerve cells of the hippocampus and cerebellum in 92 female autopsy cases aged 56-101 was micrometrically compared with regard to their age and grade of dementia. Highly significant differences were found in the amount of pigment between the nerve cells of the granular and pyramidal layers of the hippocampus and between Purkinje cells and dental nuclear cells of cerebellum. No significant difference, however, was observed according to age or to grade of dementia.

Age Factors↗
PubMed1988

Age-related alteration of renal brush border leucine aminopeptidase in rat kidney cortex.

Renal brush border enzyme activities were significantly decreased with age. The decrease was observed in the homogenate and brush border fractions. Purified leucine aminopeptidase was significantly decreased in Vmax and Km value for leucyl-beta-naphthylamide in the old rats. Heat stability of leucine aminopeptidase from both old and young rats showed biphasic, and the enzyme from old rats was more stable at 60 degrees C than that of the young. However, other properties such as molecular weight, antigenicity, charge, and optimum pH were not significantly different between young and old rats. From these results, it is suggested that age-related alteration of leucine aminopeptidase is due to a conformational change of enzyme molecule; the conformational change might occur at the active sites of the enzyme.

Aging↗
PubMed1988

Morphometrical and biochemical analysis on autofluorescent granules in various tissues and cells of the rats under several nutritional conditions.

The effects of age and nutritional conditions on accumulation of autofluorescent granules in various organs and tissues of male Sprague-Dawley rats were compared morphometrically. The relative intensity of the specific fluorescence of these autofluorescent granules was similar in all tissues and cells examined. In almost all cases, there were more autofluorescent granules in the 12-month experiment than in the 4-month one. Multiple necrotic foci of myofibrils with an accumulation of autofluorescent granules were seen in striated muscles in the rats on vitamin E-deficient diets for 12 months. In splenocytes, renal proximal convoluted tubules and hepatic cells, autofluorescent granules quantitatively increased significantly with an increase of the corn oil contents in the diets. The increase was rather marked in the splenocytes and renal epithelia of vitamin E-deficient rats. In the Purkinje cells and bronchial epithelial cells, no significant differences were noted according to the difference in the vitamin E and corn oil contents in diets. The accumulation of autofluorescent granules was not merely considered to be an age-related change, but to be influenced by a relationship to the cell metabolism and functional activity in various organs.

Animals↗
PubMed1986

Difference in activation by Tris(hydroxymethyl)aminomethane of Ca,Mg-ATPase activity between young and old rat skeletal muscles.

Fresh weight of rat skeletal muscles (M. tibialis anterior) was decreased with age. Specific activity of myosin-ATPase in the homogenate was decreased significantly at later stages of age, but not Ca,Mg-ATPase activity. The activity of Ca,Mg-ATPase was activated by high concentration (more than 75 mM) of Tris(hydroxymethyl)aminomethane. The degree of the activation was observed to be an age-related change; the activation of Ca,Mg-ATPase activity in old rats was lower than that of young rats.

Aging↗