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H Kato

Publications and source records attributed to H Kato.

At least 19 recordsLinked to original sources

Identification and phylogenetic analysis of hepatitis C virus in forensic blood samples obtained from injecting drug users.

Injecting drug users (IDUs) are a high-risk group for contracting hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) infections. In Japan, data on the prevalence of those blood-borne viruses among IDUs are very limited. Blood samples were obtained from 12 cadavers of IDUs sent to Nagoya City University for the purpose of judicious autopsy and two alive IDUs with hepatitis C referred to a local hospital at the same period. The viruses were detected by polymerase chain reaction and phylogenetic analysis was performed. Two (16.6%) of the 12 autopsy cases were positive for HCV, but no case was positive for either HBV or HIV. Phylogenetic analysis of the two HCV isolates revealed that one was classified into genotype 1b and another was genotype 2b. Furthermore, nucleotide sequences of two isolates recovered from IDUs with hepatitis C were identical, that indicated the transmission of HCV between them, and those HCV were phylogenetically classified into genotype 2a. The prevalence of HCV infection among IDUs in Japan, despite the case of judicious autopsy, seems to be high, but HIV infection seems to be rare. The transmission of HCV between IDUs was demonstrated, and this indicates that phylogenetic analysis would applicable to also forensic analysis. HCV isolates identified in this study did not phylogenetically segregate, thus multiple transmission route of HCV among IDUs seems be exist in Japan.

Adult↗

RhoA and RhoC proteins promote both cell proliferation and cell invasion of human oesophageal squamous cell carcinoma cell lines in vitro and in vivo.

There is growing evidence that Rho proteins are deregulated by overexpression in tumours; and according to some reports, this correlates with disease progression. Our previous clinical study had demonstrated a correlation between RhoA expression and tumour progression in oesophageal squamous cell carcinoma (ESCC). These findings prompted us to study, using nude mice, pathological roles of Rho proteins in human ESCC cells. Western blot analysis in ESCC cell lines, in addition to cell proliferation and in vitro migration assays, were performed to observe the malignant potential of RhoA and RhoC in untransfected and transfected cells. Constitutively active RhoA, RhoC and dominant negative RhoA (dnRhoA) proteins were transfected to ESCC (TE-1 and TE-2) cells. The stably transfected cells were injected into nude mice, and the growth and metastasis of these cells to the lungs were analysed. Tumour tissues were then examined using immunohistochemical methods for proteins Ki-67 (MIB-1), FAK, MMP-1, MMP-9 and TIMP-3. Protein levels of RhoA and RhoC in ESCC cell lines were visualised by Western blotting, and showed highest expression in TE-2 cells. Results from the migration assay illustrated that both RhoA and RhoC play a role in migration of ESCC cells. In TE-2 transfected cells, RhoC showed greater migration compared to RhoA. By using an experimental metastasis model in nude mice, RhoA was found to promote more tumour growth than RhoC, whereas RhoC induced lung metastasis in comparison to RhoA. Ki-67 labelling index was used to evaluate the proliferation potential of tumour tissue inoculated from nude mice. In TE-2 cells RhoA gave a proliferation capacity of 24.8+/-0.5, which was significantly higher than those of TE-2 RhoC 10+/-0.4 (P<0.01). Strong immunoreactivity for FAK, MMP-1 and MMP-9 proteins was present in all tumour cells. By contrast, loss of TIMP-3 expression was observed in all tumour cells. In conclusion, our results indicate that pro-oncogenic Rho proteins are involved in promoting tumour growth, cell migration and metastasis in human ESCC cells in nude mice. The results from this study suggest that active Rho proteins may induce a transforming effect that leads to a malignant phenotype.

Animals↗

Phase II trial of oral S-1 combined with gemcitabine in metastatic pancreatic cancer.

We conducted a phase II trial of gemcitabine with S-1, oral fluorouracil (5-FU) prodrug tegafur combined with two modulators, 5-chloro-2, 4-dihydroxypyridine and potassium oxonate, to evaluate the activity and toxicity of such a combination in metastatic pancreatic cancer (MPC) patients. Patients who had pathologically proven pancreatic cancer with metastatic lesions were eligible candidates for entry into the study. S-1 was given orally (30 mg m(-2)) b.i.d. for 14 consecutive days and gemcitabine (1000 mg m(-2)) was given on days 8 and 15. The cycle was repeated every 21 days. We enrolled 33 MPC patients. The median number of cycles was eight (range 1-20). Grade 3-4 toxicities were leucopenia (33%), neutropenia (55%), anaemia (9%), thrombocytopenia (15%), anorexia (6%), fever (9%), and interstitial pneumonia (6%). Objective responses were obtained in 16 patients (one complete response and 15 partial responses; response rate, 48%; 95% confidence interval (CI), 33-65). Median survival and 1-year survival rate were 12.5 months (95% CI, 5.9-19.1) and 54% (95% CI, 36-72), respectively. Combination chemotherapy with GEM and S-1 was well tolerated and yielded a significantly high response rate.

Aged↗

Time dependent alterations of co-localization of S100beta and GFAP in the MPTP-treated mice.

S100beta is a calcium-binding peptide produced by astrocytes. This protein is expressed at high levels in brain and is known as a marker of brain damage. However, little is known about the role of S100beta protein during neuronal damage caused by MPTP. To determine exactly changes of expression of S100beta protein in relation to changes of glial cells, we investigated immunohistochemically the expression of S100beta protein using MPTP-treated mice. The present study showed that tyrosine hydroxylase (TH) immunoreactivity was decreased in the striatum and substantia nigra from 5 h and 1 day after MPTP treatment, respectively. Thereafter, a severe reduction in TH immunoreactivity was observed in the striatum and substantia nigra 1, 3 and 7 days after MPTP treatment. In our double-labeled immunostaining, the number of S100-positive/GFAP-negative cells decreased from 1 day up to 7 days after MPTP treatment. In contrast, the number of double-labeled S100/GFAP-immnoreactive cells increased from 1 day up to 7 days after MPTP treatment. The number of S100beta-positive/GFAP-negative cells also decreased 3 and 7 days after MPTP treatment. In contrast, the number of double-labeled S100beta/GFAP-immunoreactive cells increased from 1 day up to 7 days after MPTP treatment. The present study demonstrates that S100beta/GFAP-positive cells may play some role in the pathogenesis of MPTP-induced dopaminergic neurodegeneration in the striatum. The present results also suggest the presence of the S100beta protein in a subpopulation of GFAP-negative astrocytes in the striatum after MPTP treatment. These results suggest that the modulation of astrocytic activation may offer a novel therapeutic strategy of Parkinson's disease.

Animals↗

Closed rupture of the flexor tendons of the little finger secondary to non-union of fractures of the hook of the hamate.

We report six patients with closed flexor tendon rupture affecting the little finger, occurring secondarily to non-union of the hook of the hamate bone. The ununited fragments were separated from the basal part of the hook by more than 1mm. The fragments were also rounded and showed marginal sclerosis. Non-union was located in the middle part of the hook in three patients, the tip in two, and the base in one. At operation, the fragments were removed in all patients. Five patients were treated by free tendon grafts using three palmaris and two plantaris grafts and one underwent tendon transfer. Postoperative total range of active motion of the little finger averaged 218 degrees (range 185-265 degrees ). All patients returned to their original employment. This series would suggest that flexor tendon rupture can occur after fracture of the hook of the hamate bone, even when the ununited fragment is small and/or rounded.

Adult↗

Experimental and theoretical elastic cross sections for electron collisions with the C3H6 isomers.

In the present work we report cross sections for electron collisions with the isomers propene (C3H6) and cyclopropane (c-C3H6). Electron-scattering differential cross sections (DCS) are reported for measurements carried out for energies 1.5-100 eV and the angular range of 20 degrees-120 degrees. Elastic integral cross sections (ECS), DCS, and momentum-transfer cross sections (MTCS) are reported for calculations carried out using the Schwinger multichannel method with pseudopotentials for the energy range of 2.0-40 eV and angular range of 0 degrees-180 degrees. The resemblance of the pi* shape resonance in the cross sections, observed at 1.5-2.0 eV for propene, to those in C2H4 and C2F4 clearly points to the effect of the double bond in the molecular structures for these molecules. Below 60 eV, we observed clear differences in peak positions and magnitudes between the DCS, ECS, and MTCS for C3H6 and c-C3H6, which we view as the isomer effect.

Journal Article↗

Basic and clinical research on photodynamic therapy at Tokyo Medical University Hospital.

BACKGROUND AND OBJECTIVES: We have been engaged in basic and clinical research on photodynamic therapy (PDT) and photodynamic diagnosis (PDD) for more than 25 years. STUDY DESIGN/MATERIALS AND METHODS: PDT for 264 centrally located early-stage lung cancer lesions yielded an initial complete response (CR) rate of 84.8%. PDT is now becoming a standard option for centrally located stage 0 (TisN0M0) and stage I (T1N0M0) lung cancer. It is an attractive option for elderly patients in poor physical condition. RESULTS: Recent results of interstitial PDT for peripheral-type lung cancers suggest that it may be a promising local curative treatment modality for lesions less than 1.0 cm in diameter. CONCLUSIONS: In this article, we introduce our recent clinical trials of PDT for lung cancers (both central and peripheral), and new techniques of PDD in sentinel node navigation biopsy for breast cancers. Moreover, we introduce basic research on cancers and infectious diseases in order to expand the clinical applications of PDT.

Adult↗

Critical role of ADP interaction with P2Y12 receptor in the maintenance of alpha(IIb)beta3 activation: association with Rap1B activation.

OBJECTIVE: Platelet integrin alpha(IIb)beta3 plays a crucial role in platelet aggregation, and the affinity of alpha(IIb)beta3 for fibrinogen is dynamically regulated. Employing modified ligand-binding assays, we analyzed the mechanism by which alpha(IIb)beta3 maintains its high-affinity state. METHODS AND RESULTS: Washed platelets adjusted to 50 x 10(3) microL(-1) were stimulated with 0.2 U mL(-1) thrombin or 5 microm U46619 under static conditions. After the completion of alpha(IIb)beta3 activation and granule secretion, different kinds of antagonists were added to the activated platelets. The activated alpha(IIb)beta3 was then detected by fluorescein isothiocyanate (FITC)-labeled PAC1. The addition of 1 mum AR-C69931MX (a P2Y12 antagonist) or 1 mm A3P5P (a P2Y1 antagonist) disrupted the sustained alpha(IIb)beta3 activation by approximately 92% and approximately 38%, respectively, without inhibiting CD62P or CD63 expression. Dilution of the platelet preparation to 500 microL(-1) also disrupted the sustained alpha(IIb)beta3 activation, and the disruption by such dilution was abrogated by the addition of exogenous adenosine 5'-diphosphate (ADP) in a dose-dependent fashion. The amounts of ADP released from activated platelets determined by high-performance liquid chromatography were compatible with the amounts of exogenous ADP required for the restoration. We next examined the effects of antagonists on protein kinase C (PKC) and Rap1B activation induced by 0.2 U mL(-1) thrombin. Thrombin induced long-lasting PKC and Rap1B activation. AR-C69931MX markedly inhibited Rap1B activation without inhibiting PKC activation. CONCLUSIONS: Our data indicate that the continuous interaction between released ADP and P2Y12 is critical for the maintenance of alpha(IIb)beta3 activation.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

Production of interferon-gamma by microglia.

Neural cells do not usually interact with immune cells because of the lack of major histocompatibility complex (MHC) antigen expression. Interferon-gamma (IFN-gamma) enables this interaction via induction of MHC antigen expression in neural cells. Thus, IFN-gamma is a critical cytokine for the development of central nervous system (CNS) pathologies. IFN-gamma, however, is considered to be produced exclusively by lymphoid cells. Here, we show for the first time that murine microglia produce IFN-gamma in response to IL-12 and/or IL-18, using RT-PCR detection of IFN-gamma mRNA and Western blotting and immunohistochemical analysis for cytoplasmic expression of IFN-gamma. Stimulation of microglia with IL-12 and IL-18 resulted in MHC class II mRNA expression in microglia. Since IL-12 and IL-18 are produced in the CNS by glial cells, these cytokines may play a critical role in the initiation of neural-immune cell interaction and the induction of autoimmune processes in the CNS via induction of IFN-gamma and MHC antigens.

Animals↗

[Surgical resection of metachronous multiple lung cancer after complete response of small cell lung cancer; report of a case].

A 76-year-old man underwent combination chemotherapy with cisplatin and etoposide and 50 Gy radiotherapy for left-sided small cell lung cancer in 1999. He achieved clinical complete response and showed no sign of recurrence on follow-up study. In December 2004, chest computed tomography (CT) revealed a 1 cm nodule in the right lung. Although no diagnosis could be made by bronchoscope, we suspected metachronous multiple lung cancer because of high 18fluorodeoxyglucose uptake with positron emission tomography (PET). The patient underwent video-assisted thoracoscopic surgery in May 2005; the frozen section diagnosis was adenocarcinoma.

Adenocarcinoma↗

Variation of microvascular blood flow augmentation--supercharge in esophageal and pharyngeal reconstruction.

AIM OF THE STUDY: A gastric tube is commonly used in thoracic esophageal reconstruction. When a gastric tube is not available, pedicled jejunum transfer and colonic interposition are alternative methods. Oral end of the reconstructed esophagus occasionally has poor blood flow and may result in partial necrosis of the oral segment. We performed additional microvascular blood flow augmentation, the "supercharge" technique, to improve a blood flow circulation in the oral segment of the reconstructed esophagus. METHODS: A series of 86 esophageal reconstructions with microvascular blood flow augmentation using the "supercharge" technique were performed. Reconstructive methods included a gastric tube in five patients, a gastric tube combined with a free jejunual graft in one, an elongated gastric tube in eight, a pedicled colonic interposition in 22, and a pedicled jejunum in 50. Recipient vessels were used in neck or chest region. RESULTS: The color and blood flow of the transferred intestine appeared greatly improved after microvascular blood flow augmentation. Thrombosis was noticed in three patients during the surgery, and all thrombosies were salvaged by re-anastomosis. There were only three patients with partial graft necrosis of oral segment, two patients with anastomotic leakage, one anastomotic stricture. CONCLUSIONS: Augmentation of microvascular blood flow by this "supercharge" technique can be expected to reduce the risk of leakage and partial necrosis of the transferred intestine. This technique contributes to the successful reconstruction of esophageal defect.

Adult↗

[Mediastinal granular cell tumor: report of a case].

Mediastinal granular cell tumor is rare. We report a case of 16-year-old woman with a granular cell tumor in the right upper-middle mediastinum. Chest computed tomography (CT) and magnetic resonance imaging (MRI) revealed a 4.0 x 2.5 x 5.5 cm well circumscribed mass in the right upper-middle mediastinum. Tumor resection was performed. It was found that the tumor involved right vagus nerve. The tumor was completely excised with combined resection of the right vagus nerve peripheral to the right recurrent nerve. Histopathologically, the tumor consisted of round to polygonal cells with abundant eosinophilic granular cytoplasm, and diagnosed a granular cell tumor.

Adolescent↗

[Small sclerosing hemangioma combined with primary lung cancer; report of a case].

A 56-year-old woman underwent a surgery for right breast cancer when she was 51-year-old. In February 2002, computed tomography (CT) was performed as a part of a follow-up study and showed 2 small nodules in the lower lobe of her right lung: one was 10 mm nodule in S9, and another was 5 mm in S6. On a follow-up CT in March 2005, the S9 nodule had enlarged to 19 mm and was looked as ground glass opacity (GGO). We thought it was primary lung cancer. In contrast, the nodule in S6 had not enlarged and it was thought to be benign. In May 2005, right lower lobectomy was performed. The S9 nodule was diagnosed as adenocarcinoma, and the S6 nodule as sclerosing hemangioma.

Adenocarcinoma↗

[Penetrating thoracic injury].

PURPOSE: To clarify the clinical aspects of penetrating thoracic injury. PATIENTS AND METHODS: Eighteen patients with penetrating thoracic injury treated from 1987 to 2005 were evaluated. There were 13 men and 5 women. The age distribution was 8 to 69 years, with an average of 36.7 years. RESULTS: There were 14 patients with stab wound and 4 with impalement injury. Five patients with stab wound were those who attempted suicide. In 4 patients with impalement injuries, the cause was fall in 2, traffic accident in 1 and sports injury in 1. The calculated injury severity score (ISS) was over 15 in 4 patients, 6 to 14 in 12, and under 5 in 2. Thoracotomy was performed in 2 patients with cardiac tamponade, 3 with massive hemothorax and 1 with an impalement injury caused by an iron bar. All of them were rescued and got well. In the other cases, after cleansing and debridement, the wound was closed and thoracic drainage was performed. Only 1 patient with cardiac arrest on arrival died within 24 hours after reviving. CONCLUSIONS: Emergent thoracotomy is indicated for patients with massive bleeding including shock, continuous air leakage and cardiac tamponade. Since cardiac arrest is difficult to cure, appropriate cooperation with the rescue team is necessary to avoid preventable trauma death.

Adolescent↗

[Usefulness of ultrasonically activated scalpel for pulmonary resection in video-assisted thoracoscopic surgery].

We evaluated the reliability and efficacy of the ultrasonically activated scalpel (Harmonic Scalpel) for pulmonary resection in video-assisted thoracoscopic surgery (VATS). Fifty-six cases of primary or metastatic lung cancer with history of lobectomy or segmentectomy from July 2003 to June 2006 were investigated. The ultrasonically activated scalpel was used to separate aborted lobulation and segment in the surgery. The outcome of the operation using the ultrasonically activated scalpel revealed the mean operation time of 224.5 minutes and mean blood loss volume of 116.7 ml. The chest drainage catheter was removed at the postoperative day 3.4 and hospitalization lasted 10.4 days on average. By means of statistical analysis, no significant differences were noted when compared with the cases using surgical stapler to separate the lobules or segments of the lungs. Histopathological results showed destruction of alveolar structures and denaturation of cells at the cut surface of the resected lung through the use of the ultrasonically activated scalpel. This method resulted in good lung expansion and preservation of the residual lung volume. Furthermore, it prevented postoperative air leakage by appropriate treatment to the cut surfaces of the residual lung. Indeed, the method appears to be useful in the separation of lung tissues in severe aborted lobulation and segmentectomy by VATS.

Aged↗