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Biomedical subjects

K Noguchi

Publications and source records attributed to K Noguchi.

At least 181 records · Page 10Linked to original sources
PubMed1997

Selection of prognostic factors of acute hepatitis type non-A, non-B for patient listing for liver transplantation.

The aim of this study was to select prognostic factors from information available on admission in order to list patients for liver transplantation before the onset of hepatic encephalopathy in patients with fatal hepatitis type non-A, non-B. Information regarding patient profile and biochemical data obtained on admission was analyzed by multiple stepwise logistic regression, and independent prognostic factors related to death were selected. Four parameters were selected as independent prognostic factors. Patient age (over 50 years), serum total bilirubin level (over 10 mg/dl), peripheral leukocyte count, and prothrombin time were independently related to death. Positive predictive value, negative predictive value, and predictive accuracy were 0.86, 0.79, and 0.84, respectively. Our model is able to predict a patient's fatal outcome much earlier than other currently used models. It will be helpful for early referral to a transplant center.

Adult↗
PubMed1997

Effects of 5-(4-piperidyl) isoxazol-3-ol (4-PIOL), a GABA(A) receptor partial agonist, on recombinant human GABA(A) receptors.

gamma-Aminobutyric acidA (GABA(A)) gated chloride ion channels were expressed from human recombinant cDNA using the baculovirus/Sf-9 insect cell expression system. The electrophysiological effects in whole-cell currents of 5-(4-piperidyl) isoxazol-3-ol (4-PIOL), a GABA(A) receptor partial agonist, were investigated on GABA(A) receptor complexes of alpha1beta2gamma2S subunits as well as a slightly modified construct of alpha1(valine 121)beta2gamma2S subunits. Here we report that (1)4-PIOL induces an inward whole-cell current in a concentration-dependent manner in both alpha1(val 121)beta2gamma2S and alpha1(ile 121)beta2gamma2S receptor subunit combinations. (2) The 4-PIOL induced whole-cell currents were more pronounced in alpha1(val 121)beta2gamma2S than in alpha1(ile 121)beta2gamma2S receptor subunit combinations. (3) 4-PIOL inhibited GABA-induced responses on alpha1(ile 121)beta2gamma2S and alpha1(val 121)beta2gamma2S receptor combinations with similar potency.

Animals↗
PubMed1997

Decreased agonist sensitivity of human GABA(A) receptors by an amino acid variant, isoleucine to valine, in the alpha1 subunit.

Recombinant human GABA(A) receptors were investigated in vitro by coexpression of cDNAs coding for alpha1, beta2, and gamma2 subunits in the baculovirus/Sf-9 insect cell system. We report that a single amino acid exchange (isoleucine 121 to valine 121) in the N-terminal, extracellular part of the alpha1 subunit induces a marked decrease in agonist GABA(A) receptor ligand sensitivity. The potency of muscimol and GABA to inhibit the binding of the GABA(A) receptor antagonist [3H]SR 95531 (2-(3-carboxypropyl)-3-amino-6-(4-methoxyphenyl)pyridazinium bromide) was higher in receptor complexes of alpha1(ile 121) beta2gamma2 than in those of alpha1(val 121) beta2gamma2 (IC50 values were 32-fold and 26-fold lower for muscimol and GABA, respectively). The apparent affinity of the GABA(A) receptor antagonist bicuculline methiodide to inhibit the binding of [3H]SR 95531 did not differ between the two receptor complex variants. Electrophysiological measurements of GABA induced whole-cell Cl- currents showed a ten-fold decrease in the GABA(A) receptor sensitivity of alpha1 (val 121) beta2gamma2 as compared to alpha1(ile 121) beta2gamma2 receptor complexes. Thus, a relatively small change in the primary structure of the alpha1 subunit leads to a decrease selective for GABA(A) receptor sensitivity to agonist ligands, since no changes were observed in a GABA(A) receptor antagonist affinity and benzodiazepine receptor binding.

Baculoviridae↗
PubMed1997

Targeted disruption of the mouse Stat3 gene leads to early embryonic lethality.

Signal transducer and activator of transcription (STAT) proteins have been shown to mediate biological actions in response to cytokines. Stat3, a member of the STAT family, is activated by a variety of cytokines, including the interleukin 6 family of cytokines, leptin, granulocyte colony-stimulating factor, and epidermal growth factor. To address the biological function of Stat3, we generated mice deficient in Stat3 by gene targeting. No viable Stat3-deficient mice could be obtained from heterozygote intercross. Analysis of embryos at several gestation times revealed that Stat3-deficient embryos showed a rapid degeneration between embryonic days 6.5 and 7.5, although they developed into the egg cylinder stage until embryonic day 6.0. These results demonstrate that Stat3 is essential for the early development of mouse embryos.

Animals↗
PubMed1997

Actin cleavage by CPP-32/apopain during the development of apoptosis.

Interleukin-1beta-converting enzyme (ICE)/ced-3 family proteases play key roles in apoptosis. However, cellular substrates for ICE family proteases involved in apoptosis are not well understood. We previously showed that actin is cleaved in vitro by an ICE family protease, distinct from ICE itself, which is activated during VP-16-induced apoptosis. In this report, we demonstrate that the actin-cleaving ICE-family protease in the apoptotic cell extract is the activated CPP-32/apopain. CPP-32 effectively cleaves actin protein to 15 kDa and 31 kDa fragments. Studies with an antibody raised against Gly-Gln-Val-Ile-Thr peptide, the N-terminal sequence of the cleaved 15 kDa actin fragment, showed that actin is also cleaved in vivo during the development of apoptosis. Moreover, Benzyloxycarbonyl-Glu-Val-Asp-CH2OC(O)-2,6,-dichlorobenzene (Z-EVD-CH2-DCB), a selective inhibitor of CPP-32(-like) protease, efficiently inhibited the cleavage of actin and the apoptosis of VP-16-treated U937 cells. Our present results indicate that actin is the substrate of CPP-32/apopain(-like) protease both in vitro and in vivo and suggest the role of actin in the control of cell growth and apoptosis.

Actins↗
PubMed1997

Enhancement of tumor cell susceptibility to tumor-infiltrating lymphocytes by cisplatin.

Some means of enhancing the susceptibility of tumor cells to tumor-infiltrating lymphocytes (TIL) are required in adoptive immunotherapy. This study was designed to investigate whether or not tumor cell lysis by TIL was enhanced by treatment of the tumor cells with cisplatin, and also to clarify the mechanism of cisplatin's action on tumor cells. Autologous tumor cells and established cancer cell lines, including KATO-III and MKN-28, were used. Cytotoxic activities of TIL, the surface antigens of tumor cells, conjugation of TIL and tumor cells, and the production of TNF alpha from TIL were analyzed. Tumor cells treated with 2 micrograms/ml cisplatin for 12 h in vitro were more susceptible to bulk-cultured TIL and TIL clones. The surface antigens of tumor cells were not altered by the treatment with cisplatin. Cisplatin-treated tumor cells showed a higher binding ratio to TIL than did non-treated tumor cells. The anti-(tumor necrosis factor) (anti-TNF) or anti-TNF receptor antibody blocked the enhancement of cytotoxic activity by cisplatin. Thus, it was clarified that cisplatin enhanced the susceptibility of tumor cells to bulk-cultured TIL and TIL clones. Furthermore, the enhancement of cytotoxic activity by TIL in cisplatin-treated tumor cells was caused by a higher binding ratio to TIL and higher susceptibility to the TNF produced by TIL.

Antigens, Neoplasm↗
PubMed1997

MRI of acute cerebral infarction: a comparison of FLAIR and T2-weighted fast spin-echo imaging.

Fluid-attenuated inversion-recovery (FLAIR) sequences have been reported to provide high sensitivity to a wide range of central nervous system diseases. To our knowledge, however, FLAIR sequences have not been used to study patients with acute cerebral infarcts. We evaluated the usefulness of FLAIR sequences in this context. FLAIR sequences were acquired on a 0.5 T superconducting unit within 8 h of the onset in 19 patients (aged 26-80 years) with a total of 23 ischaemic lesions. The images were reviewed retrospectively by three neuroradiologists, and the FLAIR images were compared with T2-weighted fast spin-echo images. All but one of the ischaemic lesions involving grey matter was clearly demonstrated on FLAIR images as increased signal intensity in cortical or central grey matter. FLAIR images were particularly useful for detecting the hyperacute cortical infarcts within 3 h of onset, which were not readily detected on the spin-echo images. In 9 of 11 patients with complete proximal occlusion, the distal portion of the cerebral artery was visible as an area of high signal intensity on FLAIR images.

Acute Disease↗
PubMed1997

Filling defect sign in CT diagnosis of ruptured aneurysm.

We have encountered a ruptured aneurysm as a filling defect in cisternal blood on CT in patients with acute subarachnoid haemorrhage (SAH), as high-attenuation blood can act as a contrast medium. We term this finding the "filling defect sign". To evaluate the usefulness of the sign in the diagnosis of a ruptured aneurysm, we retrospectively analysed CT with 10-mm-thick slices obtained within 2 days of onset of SAH in 100 consecutive patients. The sign was observed in 30 of the 100 patients, and in 13 (68%) of 19 patients with a ruptured aneurysm more than 10 mm in diameter. The filling defect sign is useful in predicting the site of rupture.

Acute Disease↗
PubMed1997

Effects of oxygen and nitrate on growth of Escherichia coli and Pseudomonas aeruginosa in the presence of organic solvents.

Escherichia coli and Pseudomonas aeruginosa grown in the presence of certain harmful organic solvents become susceptible to these solvents during the cultivation. This susceptibility is conspicuous in the stationary phase of growth. The organic solvent tolerance levels of these microorganisms were maintained when the oxygen concentration was kept high. The tolerance levels were maintained also when these organisms were grown with nitrate present under anaerobic respiratory conditions.

Escherichia coli↗
PubMed1997

Vasodilation profile of CD-832, a novel dihydropyridine derivative in rabbit aorta.

1. CD-832, nifedipine and nitrendipine, but not nitroglycerin and nicorandil, inhibited the KCl-induced contraction of rabbit aortas. 2. CD-832, nitroglycerin and nicorandil, but not nifedipine and nitrendipine, inhibited the norepinephrine-induced contraction of aortas. The inhibitory effects of these agents were either potentiated or inhibited by zaprinast or methylene blue, respectively. 3. On the KCl-induced contraction, the duration of CD-832-induced vasodilation was longer than that of nifedipine. Concerning the norepinephrine-induced contraction, the duration of CD-832-induced vasodilation was longer than that of nicorandil. 4. These results suggest that the mechanism of CD-832-induced vasodilation concerns both Ca(2+)-antagonistic action and a nitratelike action. Furthermore, the vasodilation is long lasting.

Adrenergic alpha-Agonists↗
PubMed1997

bor1-1, an Arabidopsis thaliana mutant that requires a high level of boron.

bor1-1 (high boron requiring), an Arabidopsis thaliana mutant that requires a high level of B, was isolated. When the B concentration in the medium was reduced to 3 microM, the expansion of rosette leaves was severely affected in bor1-1 but not in wild-type plants. In a medium containing 30 microM B the mutant grew normally but showed female sterility, whereas the wild type was able to set seeds. These defects of the bor1-1 mutant were not detected with supplementation of 100 microM B. In vivo concentrations of B in bor1-1 mutants were lower than those of the wild type, especially in the inflorescence stems. Tracer experiments using 10B suggested that the mutant has defects in uptake and/or translocation of B. The mutation was mapped on the lower arm of chromosome 2.

Arabidopsis↗
PubMed1997

A functional role for death proteases in s-Myc- and c-Myc-mediated apoptosis.

Upon activation, cell surface death receptors, Fas/APO-1/CD95 and tumor necrosis factor receptor-1 (TNFR-1), are attached to cytosolic adaptor proteins, which in turn recruit caspase-8 (MACH/FLICE/Mch5) to activate the interleukin-1 beta-converting enzyme (ICE)/CED-3 family protease (caspase) cascade. However, it remains unknown whether these apoptotic proteases are generally involved in apoptosis triggered by other stimuli such as Myc and p53. In this study, we provide lines of evidence that a death protease cascade consisting of caspases and serine proteases plays an essential role in Myc-mediated apoptosis. When Rat-1 fibroblasts stably expressing either s-Myc or c-Myc were induced to undergo apoptosis by serum deprivation, a caspase-3 (CPP32)-like protease activity that cleaves a specific peptide substrate, Ac-DEVD-MCA, appeared in the cell lysates. Induction of s-Myc- and c-Myc-mediated apoptotic cell death was effectively prevented by caspase inhibitors such as Z-Asp-CH2-DCB and Ac-DEVD-CHO. Furthermore, exposing the cells to a serine protease inhibitor, 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), also significantly inhibited s-Myc- and c-Myc-mediated apoptosis and the appearance of the caspase-3-like protease activity in vivo. However, AEBSF did not directly inhibit caspase-3-like protease activity in the apoptotic cell lysates in vitro. Together, these results indicate that caspase-3-like proteases play a critical role in both s-Myc- and c-Myc-mediated apoptosis and that caspase-3-like proteases function downstream of the AEBSF-sensitive step in the signaling pathway of Myc-mediated apoptosis.

Animals↗
PubMed1997

Subacute and chronic subarachnoid hemorrhage: diagnosis with fluid-attenuated inversion-recovery MR imaging.

PURPOSE: To evaluate fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) imaging in the detection of subacute and chronic subarachnoid hemorrhage. MATERIALS AND METHODS: The authors performed 19 FLAIR MR imaging examinations at 0.5 T in 14 adult patients with subarachnoid hemorrhage 3-45 days after the ictus and 22 FLAIR examinations in 22 adult control subjects. The detection of subacute and chronic subarachnoid hemorrhage on FLAIR images was compared with the detection on conventional spin-echo MR and computed tomographic (CT) images. RESULTS: In the detection of subacute subarachnoid hemorrhage, FLAIR (100% detection) was significantly superior to T1-weighted imaging (36% detection, P < .01), T2-weighted imaging (0% detection, P < .02), and CT (45% detection, P < .02 [Fisher exact test]). Although FLAIR imaging (63% detection) was superior in chronic subarachnoid hemorrhage detection, there were no statistically significant differences between modalities. FLAIR imaging demonstrated all subarachnoid hemorrhage areas as high-signal-intensity areas within 18 days and up to a maximum of 45 days after the ictus. In a blind comparison, no FLAIR images acquired in control subjects were confused with those acquired in patients. CONCLUSION: FLAIR diagnostic images are superior to conventional MR or CT images in patients with subacute subarachnoid hemorrhage.

Acute Disease↗
PubMed1997

Secondary thalamic degeneration after cerebral infarction in the middle cerebral artery distribution: evaluation with MR imaging.

PURPOSE: To evaluate secondary degeneration of the ipsilateral thalamus after cerebral infarction in the middle cerebral artery (MCA) distribution by using magnetic resonance (MR) imaging. MATERIALS AND METHODS: Thirty patients (17 men, 13 women; aged 30-85 years) with embolic cerebral infarction in the MCA distribution underwent serial MR imaging 2 hours to 12 months after a stroke. In 23 of the 30 patients, the authors evaluated cerebral blood flow with single photon emission computed tomography (SPECT). RESULTS: T2-weighted spin-echo images disclosed a hyperintense area in the ipsilateral thalamus in 14 patients (47%) 1-12 months after stroke. The hyperintense area was confined to the dorsomedial or anterior and dorsomedial nuclei of the thalamus in nine of the 14 patients; it extended from the dorsomedial or anterior and dorsomedial nuclei to the ventral lateral nucleus or pulvinar in the remaining five patients. Hypoperfusion of the ipsilateral thalamus was observed in 21 of the 23 patients who underwent SPECT. Twelve of the 21 patients also showed a hyperintense area in the ipsilateral thalamus on the MR images. CONCLUSION: MR imaging is useful in evaluating secondary thalamic degeneration after cerebral infarction. In clinical practice, this secondary degeneration should not be mistaken for other lesions such as further cerebral infarction.

Adult↗
PubMed1997

Degeneration of the ipsilateral substantia nigra after striatal infarction: evaluation with MR imaging.

PURPOSE: To evaluate the degeneration of the ipsilateral substantia nigra after striatal infarction by using magnetic resonance (MR) imaging. MATERIALS AND METHODS: Twenty-five adult patients with embolic cerebral infarction of the middle cerebral artery distribution underwent MR imaging 0-4, 5-9, 12-15, and 27-29 days after the stroke. Sixteen of them also underwent follow-up MR imaging 2-12 months after the stroke. RESULTS: Ten patients had an infarct in the striatum with or without a cortical infarct (striatal infarction group); the other 15 patients had an infarct in the cerebral cortex of the middle cerebral artery distribution without a striatal infarct (cortical infarction group). In all 10 patients with striatal infarction, a hyperintense spot appeared in the ipsilateral substantia nigra on T2-weighted fast spin-echo images 7-12 days after the onset. This area became less intense and smaller 3 months later. In the cortical infarction group, no hyperintense spot in the ipsilateral substantia nigra was observed at any time. CONCLUSION: Degeneration of the substantia nigra ipsilateral to the striatal infarction was clearly demonstrated at MR imaging. This finding should not be mistaken for further cerebral infarction.

Aged↗
PubMed1997

[Uptake of Escherichia coli lipopolysaccharide and expression of tumor necrosis factor-alpha-mRNA by isolated rat intrahepatic bile duct epithelial cells].

OBJECTIVE: To study the uptake of E. coli lipopolysaccharide (LPS) and expression of tumor necrosis factor-alpha-mRNA in isolated intrahepatic bile duct epithelial cells. METHODS: Fluorescent immunohistochemical and in situ hybridization techniques and observations with a confocal laser scanning microscope. RESULTS: Positive reactions to LPS were found in the cytoplasm of isolated intrahepatic bile duct epithelial cells after incubation with S type LPS (S-LPS) for 15 minutes, and the FITC fluorescent intensity against LPS was significantly higher than that of controls. After incubation with S-LPS for 3 hours, FITC fluorescent intensities to the expression of tumor necrosis factor (TNF)-alpha-mRNA by flurescent in situ hybridization in the cytoplasm and nuclei of cultured bile duct epithelial cells were significantly higher than that of controls. The increase of FITC fluorescent intensity to TNF-alpha-mRNA expression showed a peak at 6 hours after incubation and at various time points after incubation with LPS, the increase of fluorescent intensities in the cytoplasm were much higher than that in the nuclei. CONCLUSION: It is suggested that LPS could act on and enter into isolated intrahepatic bile duct epithelial cells and stimulate the expression of TNF-alpha-mRNA.

Animals↗
PubMed1997

[Retrospective study of 107 patients with hematospermia].

A retrospective study on 107 men with hematospermia between 1986 and 1993 is reported. The age of the patients ranged from 16 to 73 years (mean 45.6 years). Sixty five patients (60.7%) were asymptomatic except for hematospermia. Hematospermia disappeared within one month in 43% of all the patients, and in 61% of those under 40 years of age. Thirty four patients had urological diseases; 15 patients had chronic prostatitis, 10 benign prostatic hyperplasia, 3 prostatic calculi, 1 genital tuberculosis, 1 prostate cancer, and 4 other diseases. Hematospermia was ascribed to hypertension in another 5 patients. However, the cause of hematospermia was not apparent in 79% of the patients under 40. We recommend a routine physical examination to detect infectious or inflammatory lesions, in younger patients with transient hematospermia whereas a through urological screening for more serious urogenital diseases, and measurement of blood pressure in older patients especially those with persistent hematospermia.

Adolescent↗