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Biomedical subjects

T Itoh

Publications and source records attributed to T Itoh.

At least 541 records · Page 30Linked to original sources
PubMed1997

Role of volume weighted mean nuclear volume for predicting disease outcome in patients with renal cell carcinoma.

PURPOSE: Histological grading of malignancy in renal cell carcinoma is based on qualitative, morphological examination and suffers from poor reproducibility. On the other hand, estimate of volume weighted mean nuclear volume, which was developed based on a stereological technique, is an easy method to perform with high reproducibility. Furthermore, it has been reported that mean nuclear volume is remarkably correlated with prognosis of bladder and prostate cancer. We compared mean nuclear volume to a histological grading method and TNM classification in determining the prognosis of renal cell carcinoma using a Cox proportional hazards model. MATERIALS AND METHODS: A retrospective, prognostic study was done of 65 patients with renal cell carcinoma diagnosed by radical nephrectomy or needle punch biopsy between January 1978 and November 1995. Unbiased estimates of mean nuclear volume were compared to TNM classification and histological grading to determine prognostic value. RESULTS: Univariate analysis indicated that all TNM classifications, histological grades and estimates of mean nuclear volume were significantly correlated with prognosis of renal cell carcinoma. However, multivariate analysis revealed that estimates of mean nuclear volume and metastasis at diagnosis were the 2 most powerful independent predictors of disease specific survival. CONCLUSIONS: Our results indicate that estimates of mean nuclear volume are prognostically superior to morphological grading of renal cell carcinoma. We recommend mean nuclear volume estimates as an adjunct to subjective histological grading in patients with this disease.

Carcinoma, Renal Cell↗
PubMed1997

Roles of JAK kinase in human GM-CSF receptor signals.

The IL-3 and GM-CSF (hGMR) receptors consist of two subunits, alpha and beta, both of which are members of the cytokine receptor superfamily. Phosphorylation of tyrosine residues of hGMR beta subunit and several cellular proteins are observed with hGM-CSF stimulation. We analyzed role of tyrosine residue of hGMR beta subunit and nature of tyrosine kinase, JAK2 in hGMR signals using several hGMR beta subunit mutants. In addition to box1 region, a membrane distal region (a.a. 544-589) of hGMR beta is required for c-fos activation. Only one tyrosine residue (Tyr577) exists within the region 544-589, and substitution of Tyr577 to phenylalanine in GMR beta 589 resulted in the loss of c-fos activation. In contrast, the same substitution in a wild type receptor did not affect GM-CSF-induced activities such as c-fos mRNA induction and proliferation but abolished Shc phosphorylation. These results suggest that the activation of Shc is not essential for c-fos activation and several tyrosine residues co-ordinate to activate c-fos activation. It is well documented that IL-3 or GM-CSF activates JAK2 in BA/F3 cells. However the role of JAK2 in IL-3/GM-CSF functions is largely unknown. We examined the role of JAK2 in GM-CSF-induced signaling pathways. Dominant negative JAK2 (delta JAK2) lacking the C-terminus kinase domain, suppressed IL-3/GM-CSF induced c-fos activation, c-myc activation and proliferation suggesting that JAK2 is involved in both signaling pathways. PTP1D and Shc are phosphorylated by IL-3/GM-CSF in BA/F3 cells, however these phosphorylation events were inhibited by expression of delta JAK2. Taken together, these results indicate that JAK2 is a primary kinase regulating all the known activities of GM-CSF. JAK2 mediates GM-CSF induced c-fos activation through receptor phosphorylation and Shc/PTP1D activation.

Cell Division↗
PubMed1997

[A case of total arch replacement for traumatic aortic arch rupture].

We report a case of aortic arch rupture due to blunt chest trauma. A 64-year-old woman was crushed under a wood when she was working. On her arrival to our hospital, she was in shock state due to cardiac tamponade. Her chest roentogenogram showed fracture of her right-sided ribs and mediastinal widening. Her chest CT revealed hematoma around the aortic arch. Her transesophageal echography (TEE) demonstrated an intimal flap in the aortic arch. An emergency operation was performed immediately under the hypothermic circulatory arrest with a selective cerebral perfusion. As the intimal disruption was found to be extended to three fourths of the circumference of aortic arch, total arch replacement was performed. In this case, the TEE was useful for the immediate diagnosis of the aortic rupture. This was the first successful case of total arch replacement for a traumatic arch rupture.

Aorta, Thoracic↗
PubMed1997

[Are directional coronary atherectomy and Palmaz-Schatz stent more efficacious than conventional balloon angioplasty for treating de novo coronary artery lesions?].

It is unclear whether new devices such as directional coronary atherectomy (DCA) or Palmaz-Schatz stent implantation improve long-term outcomes compared with conventional balloon angioplasty in patients with stable angina and de novo coronary artery lesions of type A or type B except for complete occlusive lesions investigated by the American College of Cardiology/American Heart Association task force on percutaneous transluminal coronary angioplasty. A total of 146 patients with stable angina and simple lesions were assigned to either conventional balloon angioplasty (62 patients), DCA (50 patients), or Palmaz-Schatz implantation (34 patients). The acute results and late outcomes were assessed by coronary angiography. The results of the three procedures were similar with respect to procedural success and complications. Patients who underwent stenting or DCA had a larger immediate increase in the diameter of the lumen and a larger luminal diameter immediately after the procedure than those who underwent balloon angioplasty. At six months follow-up, the patients treated by stenting continued to have a larger luminal diameter and a lower rate of restenosis than those treated with balloon angioplasty (2.30 +/- 0.66 vs 1.85 +/- 0.83 mm, p < 0.005; 5.9% vs 29%, p < 0.05) and DCA (2.30 +/- 0.66 vs 1.90 +/- 0.96 mm, p < 0.05; 5.9% vs 24%, NS). The patients treated with balloon angioplasty had a smaller late loss than those treated with DCA or Palmaz-Schatz stent. The patients treated with DCA had a larger loss index than those treated with balloon angioplasty or Palmaz-Schatz stent. Stenting was a significant factor in decreasing the rate of restenosis by logistic regression analysis, compared with balloon angioplasty. The angiographic outcomes were better in patients who received a stent than in those who received other treatments. This study suggests that even lesions stable for treatment by balloon angioplasty and DCA can also be treated with Palmaz-Schatz stents.

Aged↗
PubMed1997

Ultrastructural demonstration of mast cells in varicose veins of lower limbs: presence of mast cell-mediated mechanism.

OBJECTIVE: Mast cells are suggested to play an essential role during development of varices in the lower limbs. EXPERIMENTAL DESIGN: Investigation of the ultrastructure of mast cells in varicose lesions. SETTING: Saga Medical School, Yamamoto Surgical Hospital. PATIENTS: Eighteen varicose veins of 17 patients and 9 normal saphenous veins of 9 patients were examined. Patients who had undergone sclerotherapy for varices were excluded. INTERVENTIONS: Radical stripping surgery was performed on all varicose veins. MEASURES: Ultrastructural observations. RESULTS: In normal saphenous veins, mast cells usually singly embedded in dense collagen bundles as resident cells. They have characteristic crystalline granules of storage type. In varicose veins, mast cells show different features such as an increase of altered granules of discharging type, degranulation and intimate relationship with fibroblasts and lymphocytes. CONCLUSIONS: The observations suggest the presence of mast cell-mediated mechanism by releasing some mediators in the development of varices.

Adult↗
PubMed1997

Proton MR spectroscopy of delayed cerebral radiation in monkeys and humans after brachytherapy.

PURPOSE: To determine whether radiation necrosis can be differentiated from residual/recurrent tumor by proton MR spectroscopy. METHODS: We studied the effects of interstitial brachytherapy on the brains of healthy monkeys and in humans with glioblastoma multiforme. The effects of radiation therapy on normal brain tissue in monkeys were assessed with sequential proton MR spectroscopic studies 1 week to 6 months after brachytherapy. Proton MR spectroscopy was also performed in five patients with residual/recurrent glioblastoma multiforme (three of whom had radiation necrosis after brachytherapy), seven patients with newly diagnosed untreated glioblastoma multiforme, and 16 healthy volunteers, who served as a control group. RESULTS: In monkeys, the ratio of N-acetylaspartate (NAA) to creatine-phosphocreatine (Cr) and the ratio of choline-containing compounds (Cho) to Cr of the reference point were significantly lower 1 week after brachytherapy than before treatment. The ratio of NAA to Cho of the irradiated area tended to be higher 1 week after brachytherapy than before irradiation. These peak metabolic ratios showed characteristic changes 6 months after treatment. In two of three monkeys, lipid signal was elevated 6 months after irradiation. In the clinical study, the ratio of NAA to Cho in the area of radiation necrosis was significantly different from that in glioblastoma multiforme when compared with the contralateral hemisphere after irradiation. In addition, lipid signal was detected in all patients with radiation necrosis. CONCLUSION: It might be possible to use proton MR spectroscopy to differentiate radiation necrosis from residual/recurrent glioblastoma multiforme on the basis of comparisons with the contralateral hemisphere after radiation therapy.

Adult↗
PubMed1997

Veno-right ventricle bypass as a lung support system during pulmonary surgery without ventilation.

A special lung support technique is required during carinal or tracheal surgery Veno-venous extracorporeal membrane oxygenation (ECMO) has become an accepted technique for temporary lung support. Therefore, the purpose of our experiments was to evaluate the effect of veno-venous ECMO (veno-right ventricle bypass) without ventilatory support. In five mongrel dogs, two venous drainage cannula were inserted into the superior vena cava through the right jugular vein and the inferior vena cava through the right femoral vein. In addition, a venous return cannula was inserted into the right ventricle (RV) through the right jugular vein. The veno-right ventricle (veno-RV) bypass system was composed of a centrifugal pump and membrane oxygenator; pump flow was maintained at 88 +/- 14 ml/kg/min. Excellent hemodynamics and good oxygenation were obtained. On the basis of these results, we conclude that veno-RV bypass may be used as lung support during pulmonary surgery even though the native lung is not ventilated during the veno-RV bypass procedure.

Animals↗
PubMed1997

Clinical significance of hepatitis GB virus C infection in alcoholic liver disease.

Recently, hepatitis GB virus C (HGBV-C) has been recovered from patients with non-A-E hepatitis. However, it has been unclear whether HGBV-C may be related to the development of alcoholic liver disease (ALD) or not. In this study, we determined HGBV-C RNA in sera from alcoholic patients without markers for hepatitis C and B viruses to evaluate the role of HGBV-C in ALD. Serum samples were obtained from 68 patients with ALD and 40 nonalcoholic patients with chronic type C liver disease. HGBV-C RNA was detected in only 3 of 68 (4.4%) patients with ALD, in 2 of 27 patients with hepatic fibrosis, and in 1 of 5 patients with chronic hepatitis. There was no HGBV-C RNA in sera from patients with fatty liver, alcoholic hepatitis, or cirrhosis. Serum levels of AST, ALT, and gamma-glutamyltranspeptidase in alcoholic patients with, as well as without, HGBV-C RNA decreased to normal levels after abstinence. In addition, an inflammatory change was not observed in liver biopsy specimens obtained from two HGBV-C-positive patients with alcoholic hepatic fibrosis. Our results clearly suggest that the prevalence of HGBV-C infection in patients with ALD is rare and that HGBV-C may not play an important role in the development of liver disease in alcoholics.

Alcohol Drinking↗
PubMed1997

[Collapse of the nasal endotracheal tube in the nasal cavity].

A 27-year-old female with maxillary maldevelopment was admitted for mandibular sagittal splitting osteotomy with mandibular progeny. General anesthesia was induced with 100 mg of propofol and 8 mg of vecuronium. When a soft and preformed 7.0 mm North-Polar-nasotracheal tube (Portex) was inserted into the nasopharynx through the left nasal cavity, it was very difficult to advance beyond the choana. After nasotracheal intubation, the buking became harder than before when she had been ventilated with a face mask. The peak airway pressure had reached higher than 50 cmH2O with ventilation of 500 ml tidal volume. Bronchoscopy revealed that the fiberscope (3.5 mm O.D.) could not go through the choanal stenosis, because it was too narrow. Therefore, she had to be intubated by a spiral tube, 6.0 mm I.D., through the other nasal cavity with assistance of bronchoscopy, instead of the North-Polar-tube. So, we have to pay attention to the possibility of compression and collapse of a soft nasotracheal tube in the nose of the patient with choanal stenosis due to maxillary maldevelopment.

Adult↗
PubMed1996

A 570-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 28.0-40.1 min region on the linkage map.

The 569,750 base pair sequence corresponding to the 28.0-40.1 min region on the genetic map of Escherichia coli K-12 (W3110) was determined. This region includes the replication terminus region and contained at least 549 potential open reading frames. Among them, 160 (29%) were previously reported, 174 (32%) were homologous to other known genes, 102 (18%) were identical or similar to hypothetical genes registered in databases, and the remaining 113 (21%) did not show a significant similarity to any other gene. Of interest was the finding of a large number of genes and gene clusters in and near the replication termination region which had been thought to be genetically silent. Those included a cluster of genes for fatty acid beta-oxidation, the third copy of the pot (spermidine/putrescine transport system) gene cluster, the second dpp (dipeptide transport system) operon, the second dsm (anaerobic dimethyl sulfoxide reductase) operon, a cluster of fim (fimbrial) genes and a DNA helicase-like gene with a high molecular weight. In addition, we found the dnaC- and dnaT-like genes in the cryptic prophage, Rac, and a number of genes originated probably from plasmids.

Chromosome Mapping↗
PubMed1996

A 460-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 40.1-50.0 min region on the linkage map.

The 465,813 base pair sequence corresponding to the 40.1-50.0 min region on the genetic map of Escherichia coli K-12 (W3110) was determined. Analysis of the sequence revealed that this region contained at least 466 potential open reading frames, of which 187 (40%) were previously reported, 105 (23%) were homologous to other known genes, 103 (22%) were identical or similar to hypothetical genes registered in databases, and the remaining 71 (15%) did not show a significant similarity to any other gene. At the 45.2-46.0 min region, we found a very large cluster of about 30 genes, whose functions are involved in the biosynthesis of polysaccharides as the components of outer membranes. In addition, we identified a new asn-tRNA gene, designated asnW, between the asnT and asnU genes and a new lysogenic phage attachment site as the cis-element.

Attachment Sites, Microbiological↗
PubMed1996

The responses of skin blood flow, mean arterial pressure and R-R interval induced by cold stimulation with cold wind and ice water.

This study was designed to evaluate the peripheral circulation response to cold wind stimulation. Skin blood flow (SBF), ECG R-R intervals (RRs) and mean arterial pressure (MAP) were measured in ten healthy men under strictly controlled conditions. Cold wind flow and ice water bath were prepared as cold stimulations. The subjects were exposed to each cold stimulation and the values of the responses were simultaneously recorded. The cold wind stimulation reduced SBF (maximally 40.4 +/- 3.2%) and increased MAP (maximally 106.9 +/- 1.3%), but did not affect RRs. On the other hand, all parameters were affected by the ice water stimulation, which reduced SBF to 16.4 +/- 1.2% and RRs to 85.1 +/- 3.0%, and increased MAP to 130.6 +/- 2.4% compared with the control state. All subjects suffered from intense pain during the ice water but not the cold wind stimulation, and two of them were eliminated from this study because of vagotonia. After phentolamine iontophoresis was used to block the receptor of peripheral alpha-adrenergic nerve terminals, the cold wind stimulation did not affect SBF. These results suggest that cold wind stimulation is a useful test for evaluating peripheral alpha-adrenergic nerve function in relation to cold sensation, without increase of RRs and noxious pain.

Adolescent↗
PubMed1996

Beta-tubulin binds Src homology 2 domains through a region different from the tyrosine-phosphorylated protein-recognizing site.

Src homology 2 (SH2) domains have been demonstrated to bind tyrosine-phosphorylated proteins that participate in signaling by growth factors and oncogenes by recognizing amino acid sequences containing phosphotyrosine residue. We found that SH2 domains such as Ash/Grb2, the 85-kDa subunit of phosphatidylinositol 3-kinase, and phospholipase Cgamma1 also bind beta-tubulin through a different region that recognizes phosphotyrosine in vitro and in vivo. Furthermore, binding occurs even when the SH2 domain is occupied by tyrosine-phosphorylated epidermal growth factor receptors. Using deleted constructs of Ash/Grb2 SH2, we found that carboxyl-terminal beta strands E and F, and alpha helix B (region "c") are required for binding. A synthetic peptide (FLWVVKFNSLNELVDYH) composed of region c inhibited the binding of beta-tubulin to the SH2 domains of Ash/Grb2, phosphatidylinositol 3-kinase, and phospholipase Cgamma1. The co-localization of SH2 proteins and microtubules is also confirmed by immunostaining. These data suggest that microtubules play important roles in the assembly of signaling molecules complexes containing SH2 proteins.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Sensitive determination of nitrotyrosine in human plasma by isocratic high-performance liquid chromatography.

A highly sensitive and simple isocratic high-performance liquid chromatographic method was developed for determination of 3-nitrotyrosine in human plasma with precolumn derivatization with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole. The precision of the method was satisfactory (coefficient of variation 4.8%), and the detection limit was established at 0.1 pmol of 3-nitrotyrosine allowing the determination at the level of 6 pmol/ml in human plasma. The recoveries of 3-nitrotyrosine and alpha-methyltyrosine, an internal standard, were 89.3 +/- 7.1 and 85.7 +/- 7.6%, respectively. The 3-nitrotyrosine level was 31 +/- 6 pmol/ml (mean +/- S.D., n = 9) in plasma from healthy volunteers. Since 3-nitrotyrosine is a stable product of peroxynitrite, an oxidant formed by a reaction of nitric oxide and superoxide radicals, the measurement of its plasma concentration may be useful as a marker of nitric oxide-dependent oxidative damage.

4-Chloro-7-nitrobenzofurazan↗
PubMed1996

Defect of thymocyte emigration in a T cell deficiency strain (CTS) of the mouse.

As bone marrow progenitors migrate to the thymus, differentiate into immunologically competent T cells, then leave the thymus and home to the peripheral lymphoid organs, each migration or homing is an essentially critical process for T cell differentiation. Homing of thymocytes into peripheral lymphoid organs has been extensively analyzed. On the contrary, little is known about the mechanism whereby mature thymocytes emigrate from the thymus to peripheral lymphoid organs. In this work, we show that the mutant T cell deficiency strain (CTS) of mouse, previously described as a peripheral T cell deficiency strain, has a novel defect of mature thymocyte emigration process. Flow-cytometric analysis demonstrated a marked decrease in T lymphocytes in peripheral lymphoid organs and an accumulation of mature thymocytes in the thymus. Histologic study revealed the high concentration of thymocytes within the giant perivascular space at thymic corticomedullary junction. These accumulating cells closely resemble normal peripheral T lymphocytes in terms of cell surface phenotype and responsiveness to mitogens or allogeneic cells. They were found to express the Mel-14 Ag, the homing receptor to lymph nodes, and had a high capability of homing to peripheral lymphoid organs when explanted thymocytes were injected i.v. The intrathymic labeling methods detected hardly any emigrating CTS thymocytes from the thymus. These results indicate that emigration defect lies in the thymus of CTS mice, and suggest that this mutation is due to abnormal releasing mechanisms occurring between the thymus and the bloodstream. Complete delineation of the precise mechanisms of this defect, however, requires further studies.

Animals↗