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Biomedical subjects

T Hashimoto

Publications and source records attributed to T Hashimoto.

At least 217 records · Page 12Linked to original sources
PubMed1994

[Quantitative analysis of EEG background activity in drug-naive schizophrenic patients].

In this study we performed quantitative EEG analyses in 12 drug-naive patients who fulfilled DSM-IIIR criteria for schizophrenia and in a group of 12 healthy subjects. The schizophrenic patients were found to have slower activity (delta and theta) than the controls. These differences were most marked in the frontal region for delta band and in the occipital region for theta band. The schizophrenic patients also had more beta 1 activity, particularly in the occipital leads. Conversely, they had less alpha 2 activity over all regions examined. Our findings indicate cerebral dysfunction in schizophrenia and are in line with the hypothesis of hypofrontality in this disorder.

Adult↗
PubMed1994

[Neurophysiologic studies on patients with migration disorder].

Neurophysiologic studies on six patients (five lissencephaly and one schizencephaly) with migration disorder were performed in order to evaluate the CNS function by multimodality evoked potentials. All cases revealed abnormalities in SSEP, four cases lost components below P 3 or had low voltage of P 3 indicating brainstem dysfunction in the somatosensory pathway. Two cases lost component below N 1 indicating sensory cortical dysfunction. Three cases revealed ABR abnormalities including a low amplitude of wave V, and one case revealed a prolonged peak latency of wave I and a low amplitude of all components. Two cases revealed abnormalities of poor cortical components in SEP, two cases in VEP, and three cases in MLR. Five cases had normal findings in P-SEP and three cases in VEP. The result of this study demonstrates that patients with migration disorder are frequently associated with cortical, brainstem and peripheral dysfunctions and has heterogeneity in pathophysiology.

Brain↗
PubMed1994

[Innate resistance to thymidylate synthase inhibition after 5-fluorouracil treatment--a rationale of combined use of cisplatin and its optimal administration dose].

We examined the changes of the number of FdU MP binding sites of thymidylate thynthase (TS-BS) in Yoshida sarcoma after administration of 5-FU to the tumor bearing rats. We also investigated the optimal dose of CDDP for the increase of intracellular folate level. In the group received consecutive 7-days administration of UFT (U-7 group), total TS-BS was significantly increased compared with non-treatment group and the group received only UFT (U-1 group). For free TS-BS, however, there was no difference despite of UFT administration. Thymidylate synthase inhibition rate (TSIR) was, therefore, significantly high in U-7 group compared with U-1 group. It seemed necessary to take some counter measure for the induction of TS in the tumor tissue when 5-FU chemotherapy was performed. The optimal dose of CDDP as a modulator of 5-FU was 1 mg/kg in rat when it was estimated from the changes of intracellular folate levels after administration, which was less than the dose to reveal its own anticancer effect.

Animals↗
PubMed1994

[A case of Mycobacterium avium complex pulmonary disease in the early phase].

A 51-year-old female was admitted to our hospital due to hemoptysis. Chest radiography revealed infiltrations in the middle lobe. Computed tomography (CT) of the thorax showed clusters of small nodules associated with a small cavity in the middle lobe, ligula and lower lobe of the right lung. Bronchiectasis was not detected. Transbronchial lung biopsy specimen (B4a) showed epithelioid cell granulomas with giant cells, and Mycobacterium avium was isolated in 4-week cultures of bronchial washings. This could be a case of early phase of pulmonary Mycobacterium avium complex infection in a patient without a so-called underlying condition. CT findings were characteristic and useful for the early diagnosis of MAC infection.

Biopsy↗
PubMed1994

[Portal-transfer of an orally administered anti-cancer agent analysis of the time course of portal blood and systemic blood levels of preoperatively administered UFT].

The transfer of an orally administered anti-cancer agent, UFT, into the portal vein was examined in 21 patients with hepatic metastasis of colorectal cancer (synchronous metastasis in 9 and metachronous metastasis in 12 cases) encountered at our department. The time course of tegafur, 5-FU and uracil levels in portal blood was traced for maximum 6 hrs, starting 2 hrs after the final oral dose of UFT. The portal blood tegafur level was 11.89 +/- 4.31 micrograms/ml at 2 hrs after the final dose and decreased gradually thereafter, reaching to 8.48 +/- 8.42 micrograms/ml at 6 hrs after the final dose. Unlike the portal blood tegafur level, the portal blood 5-FU level did not show any similar tendency; it remained almost unchanged at 0.018 +/- 0.006 microgram/ml and approximately equal to the serum 5-FU level throughout the observation period.

Administration, Oral↗
PubMed1993

Toxic effect of a beta-amyloid peptide (beta 22-35) on the hippocampal neuron and its prevention.

A synthetic truncated beta-amyloid peptide, beta 22-35, was shown to have a cytotoxic effect on cultured neurons from the rat hippocampus in serum-free medium. The peptide formed aggregates and typical amyloid fibrils resembling those of the beta-amyloid protein (AP) in neutral buffer solution and showed characteristic staining with Congo red and thioflavin-S. The neurotoxicity of beta 22-35 was suppressed by addition of calf serum, dibutyryl cAMP or insulin to culture medium, but not by addition of NGF or substance P. beta 22-35 had no effect on the glial cells. These results suggest that the AP can induce neurotoxicity in the hippocampal cells in vitro and the toxicity may involve a disorder in the intracellular signal transduction.

Amyloid beta-Peptides↗
PubMed1993

Cytokeratins in normal thymus and thymic epithelial tumors.

BACKGROUND: Thymus consists of some distinct epithelial cells that contain different sets of cytokeratins (CK). Epithelium-derived tumors maintain the expression of some of the CK of the specific nontransformed cells. Therefore, it seems reasonable to hypothesize that thymic epithelial tumors may differentiate toward distinct subsets of intrathymic epithelial cells in terms of CK expression. METHODS: Eighty-one thymomas and 14 thymic carcinomas were studied immunohistologically using monoclonal antibodies specific for a single CK or a CK pair. RESULTS: Thymic epithelial neoplasms could not be distinguished from each other on the basis of the profile of CK expression because the degree of overlap was extensive. However, polygonal cell thymomas differentiate toward a CK13-positive cortical subset that is rare in normal thymus. Spindle cell thymomas differentiate toward a CK13-positive medullary subset. Mixed cell thymomas are comprised of a CK13-positive medullary subset and a CK13-negative medullary subset, both of which are typical in normal thymus. CK18 was expressed to a greater extent on the epithelium of thymic carcinomas than on that of thymomas. Polygonal cell thymomas more frequently were invasive than spindle and mixed cell thymomas. CONCLUSIONS: There is a possibility that the epithelium of polygonal cell thymomas is immature because it is a phenotypically unusual subset in normal thymus. A thymic carcinoma arising in a thymoma has been reported, although the relationship between the thymoma and the thymic carcinoma was not clear. Nevertheless, given the similar cellular differentiation of thymoma and thymic carcinoma, CK18-positive epithelium in thymomas may be transformed into thymic carcinoma cells in certain conditions.

Adenocarcinoma↗
PubMed1993

Molecular studies of mitochondrial acetoacetyl-coenzyme A thiolase deficiency in the two original families.

We describe mutations identified in stored skin fibroblast cell lines from two original probands (JB and JM), first reported with 2-methylacetoacetic aciduria, and shown later to have a deficiency of the K(+)-activated enzyme, mitochondrial acetoacetyl-coenzyme A thiolase (T2). JB is homozygous for a 4-base insertion (GCAG) which is derived mutation. The primary mutation is an AG/gt to AG/gc transition at the 5'-splice-junction site in intron 11. An alternative splice site 4 bp downstream (Ggcag/gt) is used which causes a frame shift and replaces 39 C-terminal residues by 70 nonfunctional residues. JM is homozygous for a mutation in the translation-initiation codon (ATG to AAG). By expression analyses the JB mutation (IVS11nt2) causes an unstable T2 polypeptide and the JM mutation (M1K) severely impairs T2 mRNA translation. The JB allele associates with Dutch ancestry (no consanguinity) and the JM allele with Chilean ancestry (distant consanguinity).

Acetyl-CoA C-Acetyltransferase↗
PubMed1993

Comparison of prostanoids and their precursor fatty acids in human hepatocellular carcinoma and noncancerous reference tissues.

Eicosanoid production and the compositions of precursor fatty acids were determined in human cancerous and reference liver tissues. Seventeen hepatectomized cases (12 cases of hepatocellular carcinoma (HCC) and 5 cases of metastatic liver cancer) were evaluated. The cancerous tissues and the noncancerous reference tissues were separated, lipids were extracted, and the fatty acids were determined as methyl esters by gas chromatography. Prostanoids (6-keto PGF1 alpha and TXB2) were measured by radioimmunoassay. In HCC, the levels of alpha-linolenic acid (omega-3) (0.41 +/- 0.38 x 100 micrograms/g) and docosahexaenoic acid (10.41 +/- 4.96 x 100 micrograms/g) in liver cancer tissue were significantly less than those in the reference tissues. In HCC, the levels of TXB2 reference (1.86 +/- 2.77 pg/mg wet weight) and 6-keto PGF1 alpha were 10-fold higher than those in reference tissues. We speculate that in HCC higher prostanoid levels in the liver are related in part to tumor metabolism.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Primary brain stem lesions caused by closed head injuries.

Traumatic lesions of the brain stem are of two types: primary, which are considered to be caused at the moment of impact, and secondary, associated with supratentorial mass lesion. Of the 239 patients with a serious head injury who showed a severe disturbance of consciousness upon admission and who had CT scan carried out immediately, 21 cases were considered to have a primary brain stem lesion with initial CT scan. A primary brain stem lesion was found in 21 of 239 (8.8%) of patients with serious head injury. Their injuries were caused primarily by traffic accidents. Sixteen of the 21 cases showed not only brain stem lesions but also other brain injuries such as cerebral contusion of the white and gray matter, callosal injury, intraventricular hemorrhage, and subarachnoid hemorrhage, which are considered to be caused by a diffuse shearing injury. Five cases who showed a single injury to the brain stem with no other brain lesions were considered to have a pure brain stem lesion. Primary brain stem lesions were observed on the dorsal side of the midbrain, where they can be differentiated from secondary brain stem lesions. These lesions are considered to result from the shearing mechanism in and around the brain stem very close to the tentorial edge, or to an injury of the lower brain stem by hyperextension of the cervical vertebrae. The prognosis of patients with a primary brain stem lesion was usually unfavorable, except in those with a single brain stem lesion.

Adolescent↗
PubMed1993

Thymic epithelial tumours: evaluation of malignant grade by quantification of proliferating cell nuclear antigen and nucleolar organizer regions.

Cellular proliferation was studied by quantification of proliferating cell nuclear antigen (PCNA) and argyrophilic nucleolar organizer regions (AgNORs) of cells in 29 thymic epithelial tumours: 8 noninvasive (7 cortical and 1 mixed) thymomas, 11 invasive/metastatic (all cortical) thymomas, and 10 thymic carcinomas. Thymic carcinoma showed the highest percentage of cells positive for PCNA (14.73 +/- 5.419%) and the largest mean number of AgNORs per nucleus (4.89 +/- 0.756). The mean percentage of PCNA-positive cells and number of AgNORs in thymoma groups were as follows: in noninvasive thymoma 2.96 +/- 1.256% and 2.73 +/- 0.647, respectively, and in invasive/metastatic thymoma 4.41 +/- 1.823% and 3.68 +/- 1.148, respectively. The differences in PCNA and AgNORs were statistically significant between thymic carcinoma and each of thymoma groups. The overlap of the values between these tumours was minimal in the PCNA stains, although it was considerable in AgNOR counts as previously noted. However, there was no statistically significant difference in these markers between noninvasive and invasive/metastatic thymomas. These results indicate that thymoma in general is a slow-growing tumour compared with thymic carcinoma and that noninvasive thymoma is similar to invasive/metastatic thymoma with regard to proliferative activity; these latter two tumours may represent an essentially identical type in different stages of progression.

Antigens, Neoplasm↗
PubMed1993

Differential changes in serotonin 5-HT1A and 5-HT2 receptor binding in patients with chronic schizophrenia.

Serotonin 5-HT1A and 5-HT2 receptors were examined in the postmortem brains of controls and patients with chronic schizophrenia. In the prefrontal cortex from patients with schizophrenia, 5-HT1A receptor binding was increased, while 5-HT2 receptor binding was decreased, when compared to controls. The increased 5-HT1A receptor binding or the decreased 5-HT2 receptor binding was observed in both the patients who had been medicated with neuroleptics at time of death and those who had not, at least 2 months prior to death. Thus, abnormalities of 5-HT receptor subtypes seem to exist in the brains of patients with chronic schizophrenia. 5-HT related agents might be beneficial for the treatment of schizophrenia.

Chronic Disease↗