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Biomedical subjects

T Chiba

Publications and source records attributed to T Chiba.

At least 469 records · Page 26Linked to original sources
PubMed1991

Flow cytometric DNA analysis with use of normal lymph node cells as an internal reference standard in ovarian cancer.

Fresh frozen and paraffin-embedded tumor specimens of 21 patients with ovarian cancer were investigated by means of flow cytometry. In 4 patients, the fresh frozen tumor specimens (fresh tumor specimens) of ovarian tumors were measured for the DNA ploidy and index. We used the paraffin-embedded normal lymph node tissue specimens which were acquired from retroperitoneal lymphadenectomy as the internal reference standard (IS). In all 21 patients, the paraffin-embedded tumor specimens mixed with a lymph node specimen as an IS (tumor specimen with IS) were measured. In addition, all 21 paraffin-embedded tumor specimens without a lymph node tissue specimen (tumor specimens without IS) were measured. In 4 cases which were measured with the fresh tumor specimens, all 4 tumor specimens with IS had the same patterns of DNA ploidy as the fresh tumor specimens. Of 21 patients, 6 patients showed different DNA ploidy patterns between the tumor specimens with and without IS. Furthermore, all of these 6 patients showed diploidy in the tumor specimens without IS while showing aneuploidy in the tumor specimens with IS. Fourteen (66.7%) of 21 tumor specimens with IS were aneuploidy despite aneuploidy of only 8 (38.1%) tumor specimens without IS. All 4 patients with stage I had diploidy in the tumor specimens with IS, and 13 (81.3%) of 16 patients with stage III or IV had aneuploidy. All 8 patients with diploidy in the tumor specimens with IS had survived for 1-2 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneuploidy↗
PubMed1991

Linkage between capsaicin-stimulated calcitonin gene-related peptide and somatostatin release in rat stomach.

Calcitonin gene-related peptide (CGRP) is present in the stomach, and exogenous CGRP stimulates gastric somatostatin release. A study was undertaken to elucidate the functional linkage between CGRP and somatostatin in the stomach. Newborn Wistar rats were made CGRP deficient by intraperitoneal injection of capsaicin 2 days after birth, and then 2.5 mo later, release of CGRP and somatostatin was examined by vascular perfusion of the isolated stomach. In CGRP-deficient rats, neither the content nor basal secretion of gastric somatostatin differed from that in normal rats, and although none of several secretagogues induced CGRP secretion, the somatostatin response to glucagon was well preserved, indicating the presence of normally functioning D cells. On the other hand, arterial infusion of capsaicin significantly increased the release of not only CGRP but also somatostatin from the stomach of normal rats. In CGRP-deficient rats, however, capsaicin produced no corresponding effect. Finally, human CGRP-(8-37), a CGRP-receptor antagonist, completely inhibited the increase of gastric somatostatin induced by both rat alpha-CGRP and capsaicin infusion in normal rats. Thus the capsaicin-induced increase of somatostatin release appears to be mediated by CGRP in the stomach.

Animals↗
PubMed1991

Histopathology and distribution of cells harboring bovine leukemia virus (BLV) proviral sequences in ovine lymphosarcoma induced by BLV inoculation.

Six sheep with lymphosarcoma induced by hypodermic inoculation of bovine leukemia virus (BLV) materials were examined to elucidate the relation between pathologic lesions and integration of BLV provirus in cellular DNAs. Antibodies to BLV gp-antigens had been detected since the 3rd week after the inoculation, and BLV was positive when checked 3 months later. Lymphosarcomas followed the leukemic phase in 4 sheep. The other 2 sheep showed initial lesions of lymphosarcoma and were aleukemic clinically. Five animals were killed by enthanasia and autopsied at 2.5 to 3.5 years postinoculation (pi) because of their diseased condition. One animal died 10 years pi following the 4th leukemic episode. Sarcomatous lesions were confirmed grossly and histologically, and the proliferating neoplastic cells were classified into lymphocytic, prolymphocytic, lymphoblastic and histiocytic types. Integration of BLV provirus in cellular DNAs of the peripheral blood lymphocytes (PBL) and neoplastic cells of sarcomatous lesions was examined by Southern blotting technique. BLV provirus was demonstrated in the PBL of all infected animals and in most of the sarcomatous lesions of the spleen, kidney and lymph nodes except 4 lymph nodes showing slight neoplastic infiltration. The results indicated that ovine lymphosarcoma could be caused by BLV and the cells carrying proviral information seemed to be disseminated and proliferate in the lesions.

Animals↗
PubMed1991

A case of syndrome of inappropriate secretion of antidiuretic hormone associated with diabetes mellitus.

A 46-year-old man, presenting with headache, nausea, and lassitude, was diagnosed as having diabetes mellitus and hyponatremia, and admitted to Tohoku University Hospital. Insulin treatment improved the hyperglycemia but aggravated hyponatremia, which was proved to be elicited by the inappropriate secretion of antidiuretic hormone (SIADH). An acute water load failed to suppress ADH release in the supine posture but slightly increased plasma atrial natriuretic peptide (ANP). On the other hand, plasma ADH markedly increased in response to an upright posture, accompanied by a fall in blood pressure and a rise in heart rate. After treatment with droxidopa "a sympathomimetic drug", ambulatory blood pressure gradually increased and hyponatremia disappeared. However, blood pressure and ADH responses to upright posture were not improved by treatment with the drug. Moreover, plasma ADH was still not sufficiently suppressed by acute water loading in the supine position, but plasma ANP markedly increased, thereby resulting in urinary dilution and natriuresis. These results suggest that exaggerated ADH release (SIADH) was brought about by the baroreceptor reflex stimulated by the postural hypotension, and also by the impaired osmoregulation associated with diabetic neuropathy, and that droxidopa improved cardiovascular function and increased ANP release with resultant urinary dilution and natriuresis in spite of slightly increased ADH release.

Blood Pressure↗
PubMed1991

Aclacinomycin, an anti-leukemic anthracycline, impairs human neutrophil functions.

The effects of aclacinomycin, an anti-leukemic anthracycline, on human neutrophil functions were investigated. The release of superoxide (O2-) in neutrophils stimulated by opsonized zymosan, myristate, or phorbol myristate acetate was inhibited by aclacinomycin in a dose- and time-dependent manner. The phagocytosis of yeast particles and oil droplets, and membrane potential changes stimulated by phorbol myristate acetate were also inhibited by aclacinomycin. On the other hand, the O2(-)-producing enzyme (NADPH oxidase) in the particulate fraction prepared from myristate-stimulated neutrophils was not affected by aclacinomycin. When high concentrations of aclacinomycin (10-100 micrograms/ml) were employed, significant inhibition of O2- release, phagocytosis, and membrane potential changes was observed within 5 min. Phagocytic activity was also inhibited when neutrophils were preincubated for 13 h at 37 degrees C with a low concentration (40 ng/ml) of aclacinomycin, which could be obtained by intravenous administration of 20 mg aclacinomycin. Myristate-induced O2- release was not impaired by cytosine arabinoside (2-800 micrograms/ml), vincristine (0.1-100 micrograms/ml), adriamycin (25-100 micrograms/ml), or daunomycin (5-75 micrograms/ml) when the cells were preincubated with these drugs for 5 min at 37 degrees C. These findings suggest that aclacinomycin inhibits the respiratory burst by impairing the activating system of NADPH oxidase and phagocytic activity.

Aclarubicin↗
PubMed1991

[Detection of human papillomavirus types 16, 18 and 33 in exfoliated cervical cells by polymerase chain reaction].

Human papillomavirus (HPV) types 16, 18 and 33 were identified by means of the polymerase chain reaction using exfoliated cells from the uterine cervix in 361 patients. Of 261 patients without cervical lesions, 10(3.8%) patients had HPV DNA whereas 7(70.0%) of 10 patients with invasive cervical carcinomas had HPV DNA. The younger patients' group (29 year-old or less) without cervical lesions had a 6.5% HPV positive rate which was distinctly higher than the older patients' groups. No menopausal patient without cervical lesions had HPV DNA. In the cervical dysplasia group, the HPV DNA positive rate tended to be higher in the older patients. Type 16 was detected more often than types 18 or 33. However, the detectable incidence of type 16 in the follow up group was lower than in the cervical carcinoma groups. The younger patients without cervical lesions had a higher incidence of type 16 than the older patients. The younger patients with cervical neoplastic lesions had a lower incidence of type 16 than the older patients. These results suggest that type 16 has a higher frequency of cervical HPV infections than types 18 and 33. In addition, human papillomavirus is not the only causative factor in cervical carcinomas.

Adult↗
PubMed1991

Co-localization of ras gene products and cathepsin L in cytoplasmic vesicles in v-Ha-ras-transformed NIH3T3 mouse fibroblasts.

Subcellular localisation of Ha-ras gene products (p21) and cathepsin L was investigated by immunocytochemical studies. Western blotting analysis by using v-Ha-ras p21 deletion-insertion mutants indicated that NCC-RAS-001 and -004 monoclonal antibodies recognize epitopes within amino acids 126-140 and 146-165, respectively, of Ha-ras p21. Indirect immunofluorescent studies using these antibodies showed that ras p21 is distributed in patch-shaped structures in the cytoplasm. Cathepsin L whose activity is effectively inhibited by p21s in vitro was found in the regions where p21s are concentrated. These p21-concentrated regions may be derived from endosome-like vesicles because they are also labeled with Lucifer Yellow. The co-localization of p21 and cathepsin L in cytoplasmic vesicles was also confirmed by electron microscopic immunocytochemistry.

3T3 Cells↗
PubMed1991

[Detection of hepatitis C virus antibody in non-A non-B liver diseases].

Hepatitis C virus antibody (anti-HCV) was assessed in serum samples from patients with non-A, non-B liver diseases using an Ortho HCV ELISA kit. In patients with posttransfusion hepatitis, anti-HCV was found in 89% and the interval between onset and anti-HCV seroconversion was 51 to 168 (mean 80) days. Anti-HCV remained positive with fluctuating serum GPT levels in 88% of the patients in whom anti-HCV seroconversion was observed. In chronic liver diseases, anti-HCV was found in 70 to 100%, being more common in patients who had a history of blood transfusion. The average interval between transfusion and detectable anti-HCV was 21.5 years. Anti-HCV was also found occasionally in patients having normalized serum GPT level after the onset, HBV carrier with posttransfusion hepatitis and patients with autoimmune hepatitis. Decreasing anti-HCV titer was noted with the normalization of serum GPT levels in the patients who received interferon therapy. These findings suggest that anti-HCV is closely associated with blood transfusion and HCV infection plays an important role in non-A, non-B liver diseases. The improvement of the current HCV assay system seems to contribute to further evaluation of the clinical entity of HCV infection.

Adult↗
PubMed1991

[An effect of priming task repetition on memory processes in an epileptic with amnesia].

The purpose of this paper is to investigate memory processes in an epileptic with amnesia. Selective impairment of memory in organic amnesia has been reported in some clinical observations. They also demonstrated that organic amnesia can retain some aspects of learning experience, despite their inability to recollect them. We investigated an effect of priming task repetition on memory processes in a female with organic amnesia aged 28 (probable encephalitic patient) and eight control college students aged 20-26. In this paper, her memory processes were analyzed, using the same picture priming task, carried twelve times during the period of seven months. We used semantic priming paradigm. Three types of prime-target pair were used: identical, semantically related and unrelated. After a prime picture, a target picture appeared on the CRT display. She was asked to name each target as rapidly and accurately as possible. We analysed reaction time (RT) in naming the picture targets, error rate, and verbal reports of the priming task in the pre- and post-examination interview. In the first examination, priming effect was observed in her RT as in the controls'. This suggests that she retained some amount of semantic memory, and the structure of her semantic memory closely resembled that in the controls. Naming RT reduced and error rate decreased with repetition of the examination. This suggests that she acquired picture naming skill during early few examinations. However it was difficult for her to recognize and recollect the picture stimuli in this period. Further, she did not show any episodic memory of the examinations. There was dissociation between improved RT performance and poor verbal reports during early few examinations. When the same priming task was repeated in early few examinations, the priming effect became weaker in her RT. In the controls, on the contrary, the priming effect remained during the whole task repetition. Semantic strategy was apparently used in the controls, but not in the amnesic patient. She apparently used strategy of non-semantic association between the prime and target. In the last few examinations, her naming RT delayed and the priming effect was observed again as in the first examination. She seemed to use semantic strategy. In addition to this priming effect, she re-collected a few pictures and showed some episodic memory of the examination.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1990

Two cytosolic components of the neutrophil NADPH oxidase, P47-phox and P67-phox, are not flavoproteins.

Two cytosolic proteins, p47-phox and p67-phox, have been shown to be essential components of the NADPH-dependent oxidase of human neutrophils, although the specific role of each of these proteins in the multicomponent electron transport complex is undetermined. The superoxide-generating activity of this oxidase can be reproduced in a cell-free system, combining cytosol and membranes from unstimulated neutrophils in the presence of fatty acid and NADPH. In the present studies, cytosol was treated with myristic acid, arachidonic acid, or sodium dodecyl sulfate in the absence of membranes and the resultant precipitate collected by centrifugation and analyzed. Both p47-phox and p67-phox precipitated in the presence of fatty acid. However, neither FAD nor FMN was localized in the precipitates, even though substantial amounts of p47-phox and p67-phox precipitated. These results suggest that neither p47-phox nor p67-phox is a flavoprotein and that neither, therefore, is the oxidase component which accepts electrons from NADPH.

Arachidonic Acid↗
PubMed1990

Induced circular dichroism of eosin-5-maleimide bound to band 3 of human erythrocytes.

The inhibition of anion exchange in human erythrocyte membrane by eosin-5-maleimide (EMI) was examined at various pH values. At the pH region between pH 6.0 and 8.0, EMI inhibited the sulfate efflux by about 90%. Further, the interaction of EMI molecules with erythrocyte ghosts was studied by induced circular dichroism (CD). At acidic pH, the EMI-ghost system showed a positive band at about 552 nm and negative bands at about 523 and 505 nm. When the ghosts had been preincubated with N-ethylmaleimide, which is a modifying reagent for cysteine residues, the intensity of the CD bands was decreased. On the other hand, when the ghosts had been preincubated with 4,4'-diisothiocyanostilbene-2,2'-disulfonate or eosin-5-isothiocyanate, which inhibit the anion exchange by binding to membrane from outside of the cell, EMI CD was not influenced. These results and the experiment of trypsin digestion, suggested that the induced CD originated from the complexation of EMI molecules with SH groups on band 3 protein. A conventional Gaussian analysis of the CD spectrum at pH 6.0 revealed that the CD spectrum was composed of three components; one of them may be from EMI monomers bound to a cryptic SH group on the 17K fragment and two of them were coupling-type CD bands originating from EMI dimer and/or trimer. The EMI dimer and trimer, which should be located predominantly on the cytoplasmic SH groups on the 43K fragment, were considered as 'stacking' and/or 'head to tail' arrangements. At pH 7.4, the CD spectrum originating from EMI monomers, which showed a negative band at about 560 nm and a positive band at about 535 nm, could be observed.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1990

Developmental changes of expression of non-muscle (beta and gamma) actin mRNAs in the central nervous system studied by in situ hybridization.

In situ hybridization of mRNAs for beta- and gamma-cytoplasmic non-muscle actin in the mouse central nervous system revealed their differential expression correlating with the developmental stages. Most intense expression of both isoactin mRNAs at the specific postnatal developmental stage was observed in pyramidal cells of cerebral cortex. Purkinje cells of the cerebellar cortex and facial motor neurons.

Actins↗
PubMed1990

CSF beta-endorphin, HVA and 5-HIAA of dementia of the Alzheimer type and Binswanger's disease in the elderly.

Cerebrospinal fluid (CSF) concentration of beta-endorphin (beta-Ep), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) was measured in 15 patients with dementia of the Alzheimer type (DAT) and in 16 patients suspected of having Binswanger's disease (BD) by MRI, which sometimes resembles DAT clinically. These were classified into three stages according to severity of dementia, Stage 1 (mild dementia)-Stage 3 (severe dementia). CSF levels of HVA decreased significantly in severe dementia, but the level of 5-HIAA did not correlate with dementia severity in both dementia groups. beta-Ep levels did not differ significantly between any stages of DAT, and among controls. beta-Ep levels, however, in BD Stage 1 (27.5 +/- 5.9 pg/ml) were significantly higher (p less than 0.05), but level in Stage 3 (6.7 +/- 2.0) was significantly lower (p less than 0.001) than in the controls (19.2 +/- 4.5). These results suggest that CSF beta-Ep may depend on the cause of dementia rather than severity of dementia, and could possibly distinguish the closely resembling BD from true DAT.

Alzheimer Disease↗