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Biomedical subjects

Y Noguchi

Publications and source records attributed to Y Noguchi.

At least 91 records · Page 5Linked to original sources
PubMed1999

Insulin resistance was connected with the alterations of substrate utilization in patients with cancer.

To elucidate the contribution of insulin resistance to substrate utilization, insulin sensitivity and substrate oxidation were examined in 19 cancer patients and five normal controls using the euglycemic hyperinsulinemic glucose clamp technique combined with indirect calorimetry. Glucose uptake and storage were significantly decreased in cancer patients compared with that of controls. In cancer patients, both glucose storage and oxidation were positively correlated with metabolized glucose as measured by the M value in cancer patients. Decrease in glucose uptake was mainly a reflection of decreased glucose storage rather than glucose oxidation. Inversely fat oxidation was negatively correlated with both the M value and glucose oxidation in cancer patients. In cancer patients with insulin resistance, decreased glucose uptake was closely associated with a rapid decrease in glucose storage, an increase in fat oxidation and a mild decrease in glucose oxidation, suggesting that insulin resistance was connected with the alterations of substrate utilization which may induce host depletion.

Adult↗
PubMed1999

Glucose uptake in the human gastric cancer cell line, MKN28, is increased by insulin stimulation.

The expression of the insulin-responsive glucose transporter (GLUT) 4 was studied in three histologically different human gastric cancer cell lines, MKN28, MKN45, and STSA. RT-PCR demonstrated GLUT1 and GLUT4 mRNA in all three cell lines. MKN28 cells expressed GLUT4 protein more than MKN45 and STSA cells by immunohistochemistry. Insulin stimulation of MKN28 cells resulted in a 22% increase in glucose uptake over that found under basal conditions (0.60 +/- 0.05 fmol/cell per min after insulin stimulation versus 0.53 +/- 0.07 fmol/cell per 3 min at basal). No increase in glucose uptake occurred with insulin stimulation in MKN45 or STSA cells. We conclude that the insulin responsive GLUT4 is expressed in MKN28, MKN45, and STKM1 human gastric cancer cell lines, albeit in different amounts. The greater expression of this transporter in MKN28 cells is likely responsible for the cell's ability to increase glucose uptake with insulin stimulation. However, the role played by GLUT4 in regulating the amount of glucose uptake would not be large in those human gastric cancer cell lines.

Biological Transport↗
PubMed1999

73-kDa heat shock cognate protein interacts directly with P27Kip1, a cyclin-dependent kinase inhibitor, during G1/S transition.

Although heat shock proteins (HSPs) were discovered as inducible proteins by the physical stress to protect cells, recent evidence has suggested that HSPs are likely involved in cell cycle control under normal conditions without stress. In the present study, we demonstrated that 73hsc (heat shock cognate protein), which belongs to the HSP70 family of molecular chaperones, interacts with P27Kip1, an inhibitor of cyclin-dependent kinase, during G1/S transition. 73hsc was detected in the immunoprecipitates with anti-P27Kip1 antibody and, vice versa, P27Kip1 was present in the immunoprecipitates with anti-73hsc antibody by Western blotting using growth-stimulated rat thyroid FRTL-5 cells. This complex formation of 73hsc and P27Kip1 was cell cycle dependent and its maximum formation was observed at G1/S transition where the level of P27Kip1 dramatically decreased. ATP dissociated this complex formation in a dose-dependent manner. These data indicated that 73hsc might be involved in the cell cycle progression through the regulation of cell cycle regulators such as P27Kip1.

Adenosine Diphosphate↗
PubMed1999

Inhibition of IRS-1 phosphorylation and the alterations of GLUT4 in isolated adipocytes from cachectic tumor-bearing rats.

Cellular and molecular mechanisms of insulin resistance in isolated adipocytes from methylcholanthrene-induced sarcoma-bearing rats were investigated by measuring 3-O-[14C]methyl glucose transport activity, glucose transporter-4 (GLUT4) protein in both plasma membrane and low-density microsomes, and insulin-stimulated tyrosine phosphorylation of the insulin receptor (IR) and insulin receptor substrate-1 (IRS-1). Compared to both pair-fed and freely fed controls, tumor-bearing rats (TBR) had a decreased insulin-stimulated glucose transport activity with a lower Vmax and a higher EC50. GLUT4 protein in low-density microsomes from adipocytes maintained at the basal state was less in TBR than in controls. In insulin-stimulated adipocytes, GLUT4 protein in plasma membranes was also less in tumor-bearing rats than in controls. Insulin-induced tyrosine phosphorylation of IRS-1 was less in TBR than controls, but that of the IR was similar among the three groups. These data suggest that the insulin resistance seen in adipose cells of these tumor-bearing rats was caused in part by a decreased amount of GLUT4 protein in both basal and insulin-stimulated states resulting from the selective inhibition of insulin-stimulated phosphorylation of IRS-1.

Adipocytes↗
PubMed1999

Direct interaction between a quinoline derivative, MS-209, and multidrug resistance protein (MRP) in human gastric cancer cells.

MS-209 is a novel quinoline derivative reversing P-glycoprotein-mediated multidrug resistance (MDR). We investigated the interaction between MS-209 and multidrug resistance protein (MRP) in MRP-overexpressing human gastric cancer cells. We measured [3H]leukotriene C4 uptake into the membrane vesicles of the cells and intracellular calcein and [3H]vincristine accumulation with or without MS-209. In multi-drug-resistant MKN45R0.8 cells selected by doxorubicin, MS-209 dose dependently reduced MRP-mediated [3H]leukotriene C4 uptake and increased calcein accumulation. In both resistant and unselected cell lines expressing the MRP gene, MS-209 increased [3H]vincristine accumulation in proportion with the level of MRP mRNA expression and enhanced the cytotoxicity of etoposide, doxorubicin, and vincristine. The reversal effects correlated with the level of MRP mRNA expression in these cells. Our results indicate that MS-209 effectively reverses intrinsic and acquired MRP-mediated MDR of gastric cancer cells by interacting directly with MRP.

ATP-Binding Cassette Transporters↗
PubMed1999

Isolation of Biopterin-alpha-glucoside from Spirulina (Arthrospira) platensis and Its Physiologic Function.

: A fluorescent substance was isolated from the cyanobacterium with a yield of 4.5 mg per 10 g of dried Spirulina (Arthrospira) platensis cells by gentle extraction and ethanol fractionation followed by column chromatography. The fluorescent substance, which has absorption maxima at 256 nm and 362 nm (pH 8.4), was identified as biopterin-alpha-glucoside by spectrophotometry and nuclear magnetic resonance spectroscopy. Biopterin-alpha-glucoside prevented decolorization of the photosynthetic pigments, chlorophyll a, phycocyanin, and carotenoids in photosynthetic vesicles of Spirulina platensis cells, by ultraviolet irradiation.

Journal Article↗
PubMed1999

A clinicopathologic study of transient osteoporosis of the hip.

OBJECTIVE: It has been proposed that transient osteoporosis of the hip (TOH) may represent the early reversible phase of osteonecrosis of the femoral head (ON). The purpose of this study was to investigate the clinicopathologic characteristics of three cases of TOH. DESIGN AND PATIENTS: A bone biopsy was performed on three patients who had been diagnosed as having TOH based on the clinical course, radiograph, bone scintigram, and MR images. The biopsy specimens were studied histopathologically by light and electron microscopy. RESULTS: The most characteristic feature of TOH was focal areas of thin and disconnected bone trabeculae covered by osteoid seams and active osteoblasts. The surrounding bone marrow tissue showed edematous changes and mild fibrosis, frequently associated with vascular congestion and/or interstitial hemorrhage. No osteonecrotic region was observed in either the bone trabeculae or the bone marrow tissue. All patients have improved clinically and in the 3.5-9 years of follow-up have shown no evidence of ON. CONCLUSIONS: This study supports the concept that transient osteoporosis of the hip is a distinct entity.

Adult↗
PubMed1999

Molecular characterization of baculovirus Bombyx mori nucleopolyhedrovirus polyhedron mutants.

Four newly isolated and two previously isolated polyhedron mutants of Bombyx mori nucleopolyhedrovirus (BmNPV) were studied. Two polyhedron deficient mutants, #126 and #136, produced small uncrystallized particles of polyhedrin in the nuclei and cytoplasm of infected cells. Mutant #211 produced a large number of variably sized polyhedra in the nucleus and #220 produced a few large cuboidal polyhedra in the nucleus. Mutant #24 and #128 were previously isolated BmNPV mutants. Mutant #24 could not produce polyhedrin mRNA and polyhedra produced by mutant #128 lacked oral infectivity. Nucleotide sequence analysis indicated that five mutants (#126, #136, #211, #220 and #128) had amino acid substitutions in polyhedrin and mutant #24 had a point mutation only in the promoter region of the polyhedrin gene. Cotransfection experiments showed that the altered phenotypes were due to the mutations found in the polyhedrin gene regions. In mutants #126 and #136, amino acid sequences of the nuclear localization signal of polyhedrin were identical to those of wild-type BmNPV, suggesting that this sequence was necessary but not sufficient for nuclear localization of polyhedrin. Electron microscopic observation revealed that fewer occluded virions were contained in polyhedra of #128 and #220.

Animals↗
PubMed1999

Radial-sequence magnetic resonance imaging in evaluation of acetabular labrum.

We investigated the usefulness of a radial-sequence magnetic resonance imaging (MRI) technique in the visualization of the acetabular labrum, which surrounds the acetabulum. In 22 hip joints of 12 volunteers, T2-weighted images were obtained on 24 radial planes of the acetabular rim, set at 15 degrees -intervals, using the small tip angle gradient echo method. We examined 7 planes in the weight-bearing portion. The acetabular labrum in the weight-bearing portion was depicted in good contrast to the surrounding tissues. The shape of the labrum differed among individuals and also in the anterior and posterior portions of the labrum. The signal intensity of the labrum was low or partially moderate. There was a high signal intensity band on the base of the acetabular labrum in several portions, which should be carefully interpreted to avoid confusion with abnormality. We concluded that radial-sequence MRI could be a useful technique for evaluation of the condition of the acetabular labrum in the weight-bearing portion.

Acetabulum↗
PubMed1999

Hearing impairment in patients with acoustic neuroma--analysis by electrocochleography.

OBJECTIVE: In patients with acoustic neuroma, the site and severity of hearing impairment are important in discussing surgical approaches. Since the effectiveness of conventional auditory psychological testing is limited, we studied objectively hearing impairment of the cochlea and the cochlear nerve due to the tumor. METHODS: Electrocochleography (ECochG) was carried out in 21 patients with acoustic neuroma. Cochlear microphonic potential (CM) and action potential (AP) in ECochG evoked with clicks and short tone bursts were recorded through a transtympanic needle electrode technique. Cochlear function was studied using the detection thresholds of CM, and cochlear nerve involvement was analyzed by differences between AP and CM detection thresholds. RESULTS: The 1 kHz CM detection threshold was elevated in 17 (81.0%) of 21 patients indicating cochlear impairment. Of seven patients with normal hearing or mild sensorineural hearing loss in pure tone audiometry, three had a slightly elevated CM detection threshold. Of five patients with pronounced pure tone levels, four showed a CM response and were thought to have mild cochlear dysfunction. Cochlear nerve impairment was confirmed in three of four patients with well-developed CM based on elevated AP detection thresholds. Three patients had CM response but no AP response, suggesting severe cochlear nerve impairment. CONCLUSION: Disorders of the cochlea and the cochlear nerve can be evaluated with ECochG AP and CM measurement. The findings of ECochG are thought to be important information to judge hearing prognosis, thereby enhancing its clinical utility.

Adult↗
PubMed1999

Does hoarseness of voice from recurrent nerve paralysis after esophagectomy for carcinoma influence patient quality of life?

BACKGROUND: Recurrent laryngeal nerve injury caused by esophageal cancer surgery is worrisome but often temporary; it is unclear when and how the paralysis is resolved. Hoarseness of voice from vocal cord paralysis (VCP) can have detrimental effects on postoperative patients. The aims of this study were to clarify the progress of nerve paralysis related to difficulty in talking after surgery and to assess whether hoarseness influences patient quality of life. STUDY DESIGN: Between 1985 and 1996, 141 esophageal cancer patients undergoing a resection by the Akiyama procedure were cancer free 1 year after surgery. Among them, 51 patients with VCP on discharge from the hospital were retrospectively reviewed. Their VCPs, body weights, and pulmonary functions were examined yearly. They were given a questionnaire relating to the difficulty in talking 1 year after surgery. RESULTS: VCP on discharge spontaneously healed within 1 year of surgery in 21 patients (41.2%), with the mean duration of difficulty in talking 5.7 months. The remaining 30 patients had persistent VCP 1 year after surgery; 4 VCPs spontaneously healed approximately 2 years after surgery. Eleven of the 30 patients with persistent VCP, who complained of severe hoarseness at 1 year postoperatively from inability to close the glottis during exertion, showed debilitation in performance status, abilities to go up stairs, and swallowing. In the group of patients with severe hoarseness, the percentage of ideal body weight (90.6%+/-11.0%) preoperatively and pulmonary functions at 3 years postoperatively were deteriorated, resulting in 3 patients with repeated aspiration pneumonia. CONCLUSIONS: The inability to compensate for aspiration, presenting as severe hoarseness, may be dependent on the preoperative nutritional state of patients along with degree of vocal cord atrophy and a decrease in pulmonary support. Persistent nerve paralysis deteriorates quality of life until it is adequately treated.

Airway Obstruction↗
PubMed1999

Inhibition of Df-protease associated with allergic diseases by polyphenol.

It was reported that Df-protease from house dust mite (Dermatophagoides farinae) catalyzes the activation of the kallikrein-kinin system in human plasma and is closely associated with mite-induced allergy. Therefore, to prevent the release of kinin by Df-protease, the inhibitory activity of polyphenols including catechins and flavonols was tested in vitro and in vivo. Among them, myricetin and epigallocatechin gallate (EGCg) effectively inhibited the amidase activity of Df-protease with K(i) values of 1 x 10(-)(8) and 6 x 10(-)(4) M, respectively. The kinin release in human plasma was extensively inhibited by the addition of EGCg in comparison with myricetin. Enhancement of vascular permeability in guinea pigs caused by Df-protease was markedly suppressed by EGCg.

Animals↗
PubMed1999

Thymidine phosphorylase/platelet-derived endothelial cell growth factor is upregulated in advanced solid types of gastric cancer.

Previous studies demonstrated that the immunohistochemical expression of thymidine phosphorylase (dThdPase) was related with distant metastasis and disease progression. In this study we investigated the production of dThdPase/platelet-derived endothelial cell growth factor in gastric cancer quantitatively. In a total of 75 tumour tissues and 60 normal gastric mucosa specimens, dThdPase protein concentrations were determined by ELISA. The amount of dThdPase was significantly higher in the tumour tissue than in the normal tissue. Intratumoural dThdPase concentrations were significantly higher in Borrmann types I and II macroscopically, in poorly differentiated and solid type histologically, in the medullary type of the tumour stroma, and in the tumour-invading serosa. In the medullary type of the amount of tumour stroma, protein levels of dThdPase were positively correlated with the vertical diameter of the tumour (r = 0.580, P = 0.019). By immunohistochemical study, dThdPase expression on tumour cells was observed in all seven specimens with high dThdPase protein levels, but not in all 14 cases with low dThdPase protein levels (P < 0.05). In summary, these data indicated that dThdPase is up-regulated in advanced solid types of gastric cancer, suggesting that dThdPase production in carcinoma cells might be induced by the microenvironment.

Analysis of Variance↗
PubMed1999

Stool smears for diagnosis of intestinal acute graft-versus-host disease.

A patient with severe diarrhea was successfully diagnosed as having acute intestinal GVHD on stool smear through detection of detached intestinal epithelial cells with apoptosis. Since a stool smear can be easily obtained non-invasively, it is a possible tool for the diagnosis of acute intestinal GVHD.

Acute Disease↗
PubMed1999

How the lymph node metastases toward cervico-upper mediastinal region affect the outcome of patients with carcinoma of the thoracic esophagus.

BACKGROUND: The aim of this study was to establish whether the site of lymph node metastasis influences the survival of patients with carcinoma of the thoracic esophagus. METHODS: A series of 159 patients with lymph node metastasis who underwent right transthoracic R0 esophagectomy was analyzed retrospectively. Sites of the nodal metastasis were divided into two regions; the neck and/or upper mediastinum above (upward metastasis) and the abdomen and/or lower mediastinum below (downward metastasis) the tracheal carina. RESULTS: Univariate analysis of prognostic factors revealed the tumor location, distant lymphatic metastasis, number of metastatic nodes and upward metastasis influenced survival, but downward metastasis did not. Multivariate analysis showed that the number of metastatic nodes and upward metastasis were also significant prognostic factors. Thirty-one (33.3%) of the 93 patients with, but only 6 (9.1%) without, upward metastasis had recurrences in the neck and/or upper mediastinum (P = 0.0002). Eighteen (60.0%) of the 30 patients with extranodal invasion in the neck and/or upper mediastinum had recurrence in these regions. CONCLUSIONS: Nodal metastasis in the neck and/or upper mediastinum was a significant risk factor for prognosis, the same as the number of metastatic nodes.

Esophageal Neoplasms↗
PubMed1999

Cochlear microphonics for hearing preservation in vestibular schwannoma surgery.

OBJECTIVES: To determine whether cochlear function is beneficial in decision-making concerning the selection of hearing preservation surgery for vestibular schwannoma. STUDY DESIGN: Retrospective review of 44 patients undergoing tumor resection with a middle fossa approach. METHODS: Cochlear microphonics in electrocochleography together with tumor size, pure-tone average (PTA), speech discrimination score (SDS), auditory brainstem response (ABR), and compound action potentials were examined. As acoustic stimuli, short tone-bursts with frequencies of 0.5, 1, and 2 kHz were employed to measure cochlear microphonics and a click was used to obtain compound action potentials. We determined detection thresholds of cochlear microphonics and action potentials. RESULTS: The overall rate of preservation of serviceable hearing was 59.1% (26/44). There were significant differences between patients with and without serviceable postoperative hearing in PTA, SDS, finding of ABR, compound action potential detection threshold, and mean cochlear microphonic detection threshold (at 0.5, 1, and 2 kHz). However, tumor size was unrelated to hearing outcome. Serviceable hearing was preserved in 23 (76.7%) of 30 patients, with a mean cochlear microphonic detection threshold of 40 dB nHL or less, suggesting normal or slightly impaired cochlear function. Hearing recovery was recognized in three patients, who also had a mean cochlear microphonic detection threshold of 40 dB nHL or less. Of the three patients, two had lower cochlear microphonic detection thresholds than audiometric thresholds, demonstrating the existence of a retrocochlear component in their hearing loss. CONCLUSIONS: The cochlear microphonic detection threshold predicts not only hearing preservation but also hearing improvement in patients with vestibular schwannomas.

Adult↗