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Biomedical subjects

Y Hata

Publications and source records attributed to Y Hata.

At least 397 records · Page 22Linked to original sources
PubMed1989

[Alveolar hydatid disease of the liver in children--radiographic findings].

The alveolar hydatid disease of the liver is uncommon in childhood. Six were less than 15 years old in our hospital. Among the first three patients, two had hepatomegaly, and the third patients had liver dysfunction. The latest three patients were detected by serological test and ultrasonographic examination in the mass screening when the lesions were too small to produce symptoms. Then CT and angiography were done for more precise examination. For the good prognosis, an early diagnosis and complete removal of the lesion are indispensable.

Adolescent↗
PubMed1989

[Evaluation of the elastase: alpha 1-antitrypsin balance in patients with bacterial pneumonia using bronchoalveolar lavage].

This study was designed to evaluate the elastase: alpha 1-antitrypsin balance in patients with bacterial pneumonia. To accomplish this, bronchoalveolar lavages were performed in patients with pneumonia and normal non-smokers. Cell differentiation counts and elastase/alpha 1-antitrypsin balances in alveolar lavage fluid were examined. To quantify antielastase capacity, total immunoreactive alpha 1-antitrypsins and active alpha 1-antitrypsins were measured in alveolar lavage fluids. To quantify elastase burden, elastase: alpha 1-antitrypsin complexes and enzymatic elastase activities in alveolar lavage fluids were measured. Significantly increased proportions of neutrophils were recovered from the alveolar lavage fluids of patients with pneumonia compared to normal non-smokers. In alveolar lavage fluids of patients with pneumonia, alpha 1-antitrypsin was inactivated and enzymatic elastase activities were demonstrated. It was concluded that elastase: alpha 1-antitrypsin imbalance do occur in alveolar lavage fluids of patients with pneumonia.

Adult↗
PubMed1989

[High-resolution computed tomography for diagnosing pulmonary complications in patients with lung cancer].

The diagnostic value of high-resolution computed tomography has been assessed in 10 lung cancer patients with pulmonary infiltrates. This method was used to evaluate the radiographic appearance of the new pulmonary disease. The expectorated sputum of each patient was examined for a bacteriologic and cytologic diagnosis. In some patients, the flexible bronchofiberscopy that was accompanied by bronchoalveolar lavage was performed so as to establish the etiologic diagnosis. In conclusion, high-resolution computed tomography was found to be useful in diagnosing pulmonary complications in lung cancer patients.

Adult↗
PubMed1989

Correction of congenital microtia using the tissue expander.

We attempted auricular reconstruction using Radovan-type inflatable silicone expanders in six children and one adult, with the complete hypoplastic, the conchal remnant, and constricted type of microtia. Ear frameworks, including the helix, anthelix, concha, and tragus, were prepared using autologous rib cartilage. Based on the surface area of the normal adult auricle, the silicone expander was tentatively shaped and sized into a rotated semiellipse and expanded with 70 cc saline. Auricular reconstruction on the framework was completed at the time of insertion in four of the seven patients, requiring no elevation of the ear. The reconstructed auricle was satisfactory in both color and texture and had nearly normal sensation. Mild complications were noted in three of the seven patients. However, no resorption of the inserted rib cartilage has been observed 14 months to 2 years and 5 months after the operation. Slight shrinkage of the expanded skin was noted in each patient.

Adolescent↗
PubMed1988

Inhibition contributes to orientation selectivity in visual cortex of cat.

Neurons in the visual cortex are selectively responsive to light or dark bars presented at particular orientations. On the basis of physiological data, this orientation selectivity is hypothesized as being due at least partially to intracortical inhibitory mechanisms. But this hypothesis has been challenged by intracellular recordings indicating that excitatory inputs themselves are orientation-selective, so inhibition may not contribute to the observed selectivity. Also, there is controversy about the presence of intracortical horizontal connections mediating inhibition for selectivity and about the theoretical validity of such inhibitory connections. Using cross-correlation analysis of the activities of two neurons recorded simultaneously, we find that inhibitory interactions exist between cells with somewhat different, but not orthogonal, orientation preferences. This suggests that intracortical horizontal inhibition operates between 'orientation columns' to sharpen the orientation tuning of cortical neurons.

Action Potentials↗
PubMed1988

Cellular glutathione conjugation of aziridines in isolated rat hepatocytes.

Glutathione conjugation of aziridines was found in isolated rat hepatocytes in experiments using the optical isomers of (1- and d-) aziridinecarboxylic acid (AZC) and (1- and d-) 1-methyl-2-beta-naphthylaziridine (NAZ). 1-AZC much more effectively consumed glutathione than d-AZC, and the yield of the glutathione conjugate during 2 hr of incubation exceeded 200% of the cellular glutathione detected at the initiation of the incubation. Such a high yield of 1-AZC-GSH conjugate would occur only when conjugation efficiently proceeds without interference against the GSH resynthesis route in the liver cells. The cytotoxicity of 1-AZC was very weak and did not affect cell viability of the isolated hepatocytes even after the formation of AZC-GSH conjugate. Consequently, we supposed that GSH is not essential for supporting the viability of the isolated hepatocytes. For very slow GSH conjugate formation of d-AZC, we envisaged poor membrane transport of the d-isomer resembling to the selective incorporation of d- and 1-proline observed in some plant cells. Both isomers of NAZ were markedly cytotoxic and depressed the cell viability. The yield of the glutathione conjugate from NAZ did not exceed the cellular GSH level detected at the initial stage of incubation. The highly cytotoxic compound nitrosomethane, generated in the first biotransformation step of the metabolism of NAZ, can obstruct the resynthesis route of GSH by inhibiting the ATP generation process as discussed previously (Ref. 3). Decreasing the cellular GSH by treatment with 1-AZC enhanced the susceptibility of the isolated hepatocytes to NAZ toxicity. d-AZC did not affect the viability of cells treated with NAZ.

Animals↗
PubMed1988

Actions of excitatory amino acid antagonists on geniculo-cortical transmission in the cat's visual cortex.

To test the possibility that glutamate and aspartate are transmitters at geniculo-cortical synapses and to elucidate which type of receptors for the excitatory amino acids (EAA) operate at these synapses, we studied effects of microiontophoretic administration of EAA antagonists on the responses of visual cortical neurons to afferent electrical and visual stimulation in the cat. The antagonists used were kynurenate, a non-selective antagonist for all classes of EAA receptors and 2-amino-5-phosphonovalerate (APV), a selective antagonist for N-methyl-D-aspartate (NMDA)-preferring receptors. The administration of kynurenate suppressed responses elicited by electrical stimulation of the dorsal lateral geniculate nucleus (LGN) and optic chiasm (OX) of 65% of the cells tested. This suppression was more marked for the short-latency responses which were evoked monosynaptically from the LGN, than for the longer-latency responses. In contrast with the effectiveness of kynurenate, APV failed to suppress electrically and visually elicited responses in 66% of the cortical cells. Such differences between kynurenate and APV were particularly prominent in layers IV and VI, which receive direct inputs from the LGN, but were less marked or were not recognizable in layers II + III and V. These results support previous suggestions that EAAs may be excitatory transmitters in the cerebral cortex, at least at geniculo-cortical synapses, and indicate further that EAA receptors of the "non-NMDA type" may be involved in afferent synaptic transmission in the cat's visual cortex.

2-Amino-5-phosphonovalerate↗
PubMed1988

Dose-dependent hypolipidemic effect of an inhibitor of HMG-CoA reductase, pravastatin (CS-514), in hypercholesterolemic subjects. A double blind test.

The hypolipidemic effect of a new HMG-CoA reductase inhibitor, pravastatin, was examined. The reductions of serum cholesterol and LDL-cholesterol were dose-dependent and significant differences were observed between placebo and 10 or 20 mg groups (P less than 0.01), and 10 and 20 mg (P less than 0.05) groups. The reduction rate of cholesterol after 8 weeks during medication was 16.1% in the 10 mg group, 20.5% in the 20 mg group compared to baseline serum cholesterol levels. LDL-cholesterol decreased by 23.9% in the 10 mg group, and 29.8% compared to baseline LDL-cholesterol in the 20 mg group. The lowering of total cholesterol was entirely attributed to a reduction in LDL-cholesterol.

Adult↗
PubMed1988

Sphincteromyectomy and sphincteroplasty in chronic constipation with megarectum.

An operative procedure for patients with chronic constipation with megarectum and its results is presented. Eleven cases of idiopathic chronic constipation showing megarectum on barium enema underwent this operation. Bowel habits of operated patients were evaluated at 1 to 5 years after the operation. Complete cure was obtained in eight cases. Three cases were improved but needed occasional suppositories. This procedure, sphincteromyectomy and sphincteroplasty, may be an operation of choice for chronic constipation with megarectum, when nonoperative methods fail.

Adolescent↗
PubMed1988

[Establishment of the human hepatocellular carcinoma cell line and its characteristics].

c-Hc-4 has been established and maintained for more than seven years. The hepatocellular carcinoma originated in 45-year old man with liver cirrhosis. The cell grew in vitro forming a sheet of monolayered cells and firmly attaching to the inner surface of cultured flasks. Morphologically they showed epithelial-like pattern. The doubling time was about 20 hours. Their modal chromosome number was 58. Serial heterologous transplantation in nude mice was successful. The histological finding was almost the same patterns as those in the primary tumor. The cultured cells produced alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA).

Animals↗