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Biomedical subjects

Y Katsuta

Publications and source records attributed to Y Katsuta.

At least 55 records · Page 3Linked to original sources
PubMed1989

Cellular substrates for epileptiform activity induced by repeated tetanic stimulation in hippocampal slices.

Using intact and transected hippocampal slices, we investigated the relationship between CA3 and CA1 subfields in the generation of stimulus train-induced bursting. In intact slices, spontaneous bursts in CA3 always preceded those in CA1, whereas after-discharge bursts in CA3 followed those in CA1 when it was possible to distinguish differences in the burst onset. After transection between CA3 and CA1, neither spontaneous nor triggered bursts could be induced or maintained in isolated CA1, where only small after-discharge bursts with higher bursting frequency were observed. Some of the mechanisms underlying the generation of these stimulus train-induced bursts are discussed.

Animals↗
PubMed1988

Molecular cloning of the penicillin G acylase gene from Arthrobacter viscosus.

Penicillin G acylase was purified from the cultured filtrate of Arthrobacter viscosus 8895GU and was found to consist of two distinct subunits with apparent molecular weights of 24,000 (alpha) and 60,000 (beta). The partial N-terminal amino acid sequences of the alpha and beta subunits were determined with a protein gas phase sequencer, and a 29-base oligonucleotide corresponding to the partial amino acid sequence of the alpha subunit was synthesized. An Escherichia coli transformant having the penicillin G acylase gene was isolated from an A. viscosus gene library by hybridization with the 29-base probe. The resulting positive clone was further screened by the Serratia marcescens overlay technique. E. coli carrying a plasmid designated pHYM-1 was found to produce penicillin G acylase in the cells. This plasmid had an 8.0-kilobase pair DNA fragment inserted in the EcoRI site of pACYC184.

Amidohydrolases↗
PubMed1987

[Clinicopathological study of 9 cases presenting axillary masses only].

A clinicopathological study of 9 cases presenting axillary mass alone was reported. Histological diagnosis revealed 3 occult breast cancers, 2 apocrine gland adenocarcinomas of the skin, a carcinoma and a fibroadenoma in the axillary accessory breast, a neurogenic tumor in the axilla, and a benign lymphadenopathy. There were no clinical characteristics helpful in preoperative differential diagnosis. As the axilla includes the main lymphatic routes from the breast, the axillary tail of the breast and accessory breast, breast-associated tumors should be kept in mind in the management of patients with axillary mass as a sole clinical feature.

Adenocarcinoma↗
PubMed1986

[Cerebellopontine angle xanthogranuloma: report of a surgical case].

A Case of xanthogranuloma at the cerebellopontine angle is reported here in detail with a review of the literature. A 36-year-old male suffered from tinnitus and hearing disturbance for five months before admission. View of the internal auditory canal showed widening and destruction on the right side. Auditory brain stem response did not clarify any of wave. A slight high density area was revealed by CT with some degree of enhancement. A right paramedian suboccipital craniectomy revealed an encapsulated tumor at the right cerebellopontine angle extending into the internal auditory canal. The tumor was reddish-brown, creamy and 2 cm in diameter, which was totally extirpated. Twenty two days after the operation, the patient was discharged with a slight improvement of the right tinnitus. Seventeen surgical cases of intracranial xanthogranuloma were reviewed including the presented case. There were 10 males and seven females, and the age ranged from six to 57 years. Many of them were located in the choroid plexus or the dura mater. The presented case was the first reported one documenting a xanthogranuloma at the cerebellopontine angle. A solitary lesion was seen in 13 cases, and multiple lesions in four cases, among which Hand-Schüller-Christian disease was observed in two, and Weber-Christian disease in one. A high density area was revealed in eight out of nine cases, and some degree of enhancement was seen in nine. Surgical removal was performed totally in nine cases, subtotally in six, and partially in one. The outcome was excellent in eight cases, good in three, fair in one, poor in two, and dead in three.

Adult↗
PubMed1983

Severe hepatitis during ketoconazole therapy.

Ketoconazole is an imidazole derivative recently developed as an antifungal agent. There have been only a few established cases of hepatotoxicity in the literature. This report describes a case of presumed ketoconazole hepatotoxicity characterized by the development of severe hepatitis with marked centrilobular necrosis. The lack of hypersensitivity reactions in clinical findings and centrilobular location of necrosis suggested a host idiosyncrasy with metabolic abnormality as the effect of ketoconazole in the present case.

Adult↗
PubMed1983

Case report of adult T-cell leukemia with preceding long-standing cutaneous involvement.

This report documents an unusual case of adult T-cell leukemia (ATL) with a preceding phase of long-standing cutaneous involvement. After nine months of an aleukemic phase, characteristic leukemic cells of ATL, possessing inducer/helper phenotype without helper function, had appeared. In addition, antibodies to ATL virus-associated antigen (ATLA) were found in the serum of the patient and her family. The patient died after an 18-month clinical course due to generalized cytomegalovirus infection in spite of strong chemotherapy. At autopsy, leukemic involvement was restricted to the skin. We postulate that ATL may originate not only from the lymph nodes but also from the skin.

Aged↗
PubMed1982

Rotor's syndrome: a study on variations in pigment metabolism with age.

The effects of aging on the pigment metabolism in Rotor's syndrome were investigated in six cases examined at least twice at an average interval of 10.5 +/- 6.5 years and additional four cases examined only once. No significant increase was found in the total (TB) or direct (DB) bilirubin in serum. However, indirect bilirubin increased significantly from 1.21 +/- 0.72 mg/dl to 2.28 +/- 1.00 mg/dl (p less than 0.05) and DB/TB ratio (% Direct) decreased significantly from 77.3 +/- 6.6% to 64.4 +/- 8.7% (p less than 0.05). BSP retentions at 45 minutes increased significantly from 26.8 +/- 10.9% to 45.3 +/- 14.9% (p less than 0.05). A significant positive correlation between the values of BSP retained at 45 minutes and the age was also observed (p less than 0.01). These results suggest that the pigment metabolism in Rotor's syndrome deteriorates with the age.

Adolescent↗