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Biomedical subjects

S Kubo

Publications and source records attributed to S Kubo.

At least 37 records · Page 2Linked to original sources
PubMed2003

Carbon dioxide insufflation for chronic subdural haematoma: a simple addition to burr-hole irrigation and closed-system drainage.

Burr-hole irrigation with closed-system drainage is a common surgical method used for chronic subdural haematoma. However, the subdural space with air that entered during surgery sometimes remains for a prolonged period after surgery and may hamper uncomplicated healing of the subdural space. We combined a simple procedure, insufflation of carbon dioxide (CO2) into the subdural space through a drainage catheter, with conventional burr-hole irrigation and closed-system drainage. By this additional procedure, both the subdural space and the gas within the space decreased rapidly, and the subdural drain could be removed within 24 h. By promoting obliteration of the subdural space, this simple combined technique may contribute to early recovery and discharge of patients, and to a reduction in the recurrence rate of the disease.

Aged↗
PubMed2003

Surgical management of synchronous hepatocellular carcinoma and gastric cancer.

BACKGROUND/AIMS: The improvement of diagnostic modalities and operative techniques has resulted in prolonged survival for cancer patients, but has also led to the diagnosis of an increasing number of patients with synchronous hepatocellular carcinoma (HCC) and extrahepatic primary cancer. It is necessary to determine the optimal surgical strategies for synchronous HCC and gastric cancer. METHODS: In this retrospective study, clinicopathologic findings, diagnostic methods, treatment and outcome were reviewed in 13 patients who underwent curative surgery for synchronous HCC and gastric cancer. RESULTS: Twelve of the 13 patients were men older than 60 years. All patients had chronic hepatic disease, and hepatitis viral infection was detected in 9 patients. Examinations of the esophagus to search for esophageal varices before liver resection for HCC, and imaging studies to rule out liver metastasis before gastrectomy for gastric cancer can lead to the incidental finding of a synchronous carcinoma. The most frequent postoperative complication was massive ascites, which occurred in 4 patients who underwent lymph node dissection, 1 of whom died of perioperative hepatic failure. HCC recurred in 7 patients, 4 of whom died of their disease; only 1 patient died of recurrence of gastric cancer. CONCLUSION: Careful follow-up for recurrence of HCC is necessary because the most common cause of death in patients with synchronous carcinoma is recurrence of HCC.

Aged↗
PubMed2002

Island dynamics in the large-helical-device plasmas.

In the Large Helical Device plasma discharges, the size of an externally imposed island with mode number ( n/m = 1/1) decreases substantially when the plasma is collisionless ( nu(*)< approximately 1) and the beta is finite ( > approximately 0.1%) at the island location. For the collisional plasmas with finite beta, on the other hand, the size of the island increases. However, there is a threshold in terms of the vacuum island size below which the island enlargement is not seen.

Journal Article↗
PubMed2002

Replication and packaging of helper-dependent adenoviral vectors.

A helper-dependent adenovirus vector (HD AdV) that lacks all the coding sequences of viral proteins from the vector backbone was developed to overcome the problem of host cellular immune responses against E1-deleted AdV. One of the limitations of the current HD AdV system is its relatively inefficient propagation compared with that of E1-deleted AdV, which deters application of the HD AdV, especially in large animal models. We hypothesized that the low titers might be due in part to defects in replication and packaging of the vector DNA. We propagated two HD AdVs with similar marker gene cassettes and stuffer sequences, using two different helper viruses, and determined the replication and packaging efficiencies of viral DNA. Our analysis indicated a difference in replication and packaging efficiencies between the two vectors, which resulted in different propagation efficiencies. Furthermore, dl309, which is similar to the wild-type virus, demonstrated superior helper function over that of the loxP-containing helper virus, AdLC8cluc. These findings may have significant implications for the design of improved production systems of HD AdVs.

Adenoviridae↗
PubMed2002

Randomized clinical trial of long-term outcome after resection of hepatitis C virus-related hepatocellular carcinoma by postoperative interferon therapy.

BACKGROUND: Interferon therapy seems to decrease the incidence of recurrence after resection of hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). Effects of postoperative interferon therapy on the survival rate after resection of such HCC are still unclear. METHODS: A prospective randomized clinical trial of postoperative interferon therapy was performed. Thirty men were allocated randomly after liver resection to an interferon-alpha group (15 patients) or a control group. Patients in the interferon group received interferon-alpha 6 MIU intramuscularly every day for 2 weeks, then three times a week for 14 weeks and finally twice a week for 88 weeks. RESULTS: The response to interferon was complete in two patients, there was a biochemical response in six patients and no response in seven patients. Interferon administration was not completed in three patients because of adverse events. Liver function did not change or worsened after operation in the control group, and did not change or improved in the interferon group. The cumulative survival rate was higher in the interferon group than in the control group (P = 0.041). CONCLUSION: Postoperative interferon therapy seems to improve the outcome after resection of HCV-related HCC.

Aged↗
PubMed2002

Morphological study of demineralized dentine after caries removal using two different methods.

BACKGROUND: Caries-affected dentine is the usual substrate bonded to in everyday clinical practice. The first step for most of the current dentine adhesive systems is etching or conditioning. It is therefore important to understand the effect of etchant/conditioner on caries-affected dentine. METHODS: Twelve extracted carious permanent molars were examined. Six teeth had caries removed using burs after staining with a caries detector dye, and caries from the other six was removed using Carisolv. After caries removal, three teeth from each group were left untreated. The remaining teeth were sectioned to obtain two normal dentine samples and two caries-affected dentine samples from each tooth. One half of the normal dentine samples and one half of the caries-affected dentine samples were treated with 35 per cent phosphoric acid, and the remaining samples were treated with 20 per cent polyacrylic acid/3 per cent aluminium chloride. The samples were observed using field emission scanning electron microscopy (FE-SEM). RESULTS: Phosphoric acid treated samples showed more obvious intertubular dentine microporosity and greater depth of demineralization in caries-affected dentine. Polyacrylic acid treated samples showed some residual smear layer. However, the peritubular and intertubular collagen network was easily observed in Carisolv treated dentine. The depth of demineralization was not as distinct as that of the phosphoric treated samples. CONCLUSIONS: From this study it was shown that etched 'normal' dentine and etched caries-affected dentine had different surface appearances. Furthermore, the two caries removal techniques resulted in different caries-affected dentine surfaces after acid treatment that may influence the longevity of bonds from adhesive restorative materials.

Acid Etching, Dental↗
PubMed2002

Adenovirus as an integrating vector.

Recombinant adenoviral vectors have served as one of the most efficient gene delivery vehicles in vivo thus far. Multiply attenuated or completely gutless adenoviral vectors have been developed to achieve long-term gene expression in animal models by overcoming cellular immunity against de novo synthesized adenoviral proteins. However, since adenovirus lacks native integration machinery, the goal of gene therapy obtaining permanent expression cannot be realized with current adenoviral vector systems. Recent studies have shown that replication-incompetent adenoviral vectors randomly integrate into host chromosomes at frequencies of 0.001-1% of infected cells. To improve the integration frequencies of adenoviral vectors, a variety of hybrid vectors combining the highly efficient DNA delivery of adenovirus with the integrating machinery of retroviruses, adeno-associated viruses, and transposons, have been emerging. These hybrid vectors have shown promise, at least in in vitro systems. Furthermore, adenoviral vectors have shown potential as gene targeting vectors. These developments should eventually lead to more effective gene therapy vectors that can transduce a myriad of cell types stably in vivo.

Adenoviridae↗
PubMed2001

Drastic up-regulation of Fcepsilonri on mast cells is induced by IgE binding through stabilization and accumulation of Fcepsilonri on the cell surface.

It has been shown that IgE binding to FcepsilonRI on mast cells results in increased FcepsilonRI expression, which in turn enhances IgE-dependent chemical mediator release from mast cells. Therefore, prevention of the IgE-mediated FcepsilonRI up-regulation would be a promising strategy for management of allergic disorders. However, the mechanism of IgE-mediated FcepsilonRI up-regulation has not been fully elucidated. In this study, we analyzed kinetics of FcepsilonRI on peritoneal mast cells and bone marrow-derived mast cells. In the presence of brefeldin A, which prevented transport of new FcepsilonRI molecules to the cell surface, levels of IgE-free FcepsilonRI on mast cells decreased drastically during culture, whereas those of IgE-bound FcepsilonRI were stable. In contrast, levels of FcgammaRIII on the same cells were stable even in the absence of its ligand, indicating that FcepsilonRI alpha-chain, but not beta- and gamma-chains, was responsible for the instability of IgE-free FcepsilonRI. As far as we analyzed, there was no evidence to support the idea that IgE binding to FcepsilonRI facilitated synthesis and/or transport of FcepsilonRI to the cell surface. Therefore, the stabilization and accumulation of FcepsilonRI on the cell surface through IgE binding appears to be the major mechanism of IgE-mediated FcepsilonRI up-regulation.

Animals↗
PubMed2001

Observation of the "self-healing" of an error field island in the large helical device.

It was observed that the vacuum magnetic island produced by an external error magnetic field in the large helical device shrank in the presence of plasma. This was evidenced by the disappearance of flat regions in the electron temperature profile obtained by Thomson scattering. This island behavior depended on the magnetic configuration in which the plasmas were produced.

Journal Article↗
PubMed2001

Reaction of D-glycals with azidotrimethylsilane.

The treatment of 2,3,4,6-tetra-O-acetyl-1,5-anhydro-D-arabino-hex-1-enitol with azidotrimethylsilane by the aid of a catalytic amount of Yb(OTf)(3) afforded 2,4,6-tri-O-acetyl-2,3-dideoxy-alpha-D-erythro-hex-2-enopyranosyl azide in high yield.

Arabinose↗
PubMed2001

Reduction of ion thermal diffusivity associated with the transition of the radial electric field in neutral-beam-heated plasmas in the large helical device.

Recent large helical device experiments revealed that the transition from ion root to electron root occurred for the first time in neutral-beam-heated discharges, where no nonthermal electrons exist. The measured values of the radial electric field were found to be in qualitative agreement with those estimated by neoclassical theory. A clear reduction of ion thermal diffusivity was observed after the mode transition from ion root to electron root as predicted by neoclassical theory when the neoclassical ion loss is more dominant than the anomalous ion loss.

Journal Article↗
PubMed2001

Effects of long-term postoperative interferon-alpha therapy on intrahepatic recurrence after resection of hepatitis C virus-related hepatocellular carcinoma. A randomized, controlled trial.

BACKGROUND: Interferon therapy decreases the incidence of hepatocellular carcinoma in patients with chronic hepatitis C. OBJECTIVE: To evaluate effects of interferon-alpha on recurrence after resection of hepatitis C virus-related hepatocellular carcinoma. DESIGN: Randomized, controlled trial. SETTING: University hospital, medical center, and affiliated hospital in Osaka, Japan. PATIENTS: 30 men were randomly allocated after resection to the interferon-alpha group (n = 15) or the control group (n = 15). INTERVENTION: Patients in the interferon-alpha group received interferon-alpha, 6 MIU intramuscularly daily for 2 weeks, then three times weekly for 14 weeks, and finally twice weekly for 88 weeks. MEASUREMENTS: Recurrence rates after resection. RESULTS: Recurrent tumors were detected in 5 patients in the interferon-alpha group and in 12 control patients. The recurrence rate was significantly lower in the interferon-alpha group than in the control group (P = 0.037). CONCLUSION: Postoperative interferon-alpha therapy appears to decrease recurrence after resection of hepatitis C virus-related hepatocellular carcinoma.

Antineoplastic Agents↗
PubMed2001

Clonal analysis of hepatocellular carcinoma and dysplastic nodule by methylation pattern of X-chromosome-linked human androgen receptor gene.

To investigate the monoclonality of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) and the origin of multiple lesions, patterns of inactivation of X-linked human androgen receptor gene were studied. Fourteen of 15 patients (93%) were heterozygous in the size of the target, and were informative for clonal analysis. Monoclonal composition was demonstrated in all 17 HCCs and two DNs, whereas all non-cancerous hepatic tissues were polyclonal. Of four patients with more than two lesions of HCC or DN, two patients had two lesions with different patterns of X-chromosome inactivation, indicating that the two lesions were multicentric in origin.

Adult↗
PubMed2001

Somatic mutation of mitochondrial DNA in cancerous and noncancerous liver tissue in individuals with hepatocellular carcinoma.

Unlike other types of cancer, hepatocellular carcinoma (HCC) is usually preceded by chronic inflammation caused by viral infection. The mutation of mitochondrial DNA (mtDNA) in hepatocarcinogenesis associated with viral infection was investigated. Compared with control liver tissue, the frequency of mtDNA mutations was markedly increased in both noncancerous and cancerous liver specimens from individuals with HCC. The accumulation of mtDNA mutations in HCC tissue reflected the degree of malignancy. The frequency of mtDNA mutations in HCC tissue was also greater than that described previously for other types of tumors. These observations suggest that the repeated destruction and regeneration of liver tissue associated with chronic viral hepatitis lead to the accumulation of mtDNA mutations. The genetic instability that results in the high rate of mtDNA mutation in cancerous liver tissue is also consistent with the multicentric hepatocarcinogenesis detected clinically.

Carcinoma, Hepatocellular↗
PubMed2001

An autopsy case of neuroleptic malignant syndrome (NMS) and its immunohistochemical findings of muscle-associated proteins and mitochondria.

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal disorder. In forensic cases, post-mortem diagnosis of NMS is sometimes difficult if ante-mortem information, such as neuroleptic ingestion or signs and symptoms, cannot be obtained. A 39-year-old Japanese male on a neuroleptic treatment regimen suddenly became agitated and died. Autopsy revealed muscle rigidity and hyperthermia. Post-mortem examination of blood revealed elevation of creatine phosphokinase-MM (CK-MM) and lactate dehydrogenase-4 and dehydrogenase-5 (LDH-4 and LDH-5). In renal glomeruli and tubules, myoglobin was stained immunohistochemically. From these findings, the cause of death was considered to be NMS. To support the diagnosis of NMS, both skeletal and cardiac muscles were stained with actin, myoglobin, desmin and mitochondria antibodies immunohistochemically. Actin, myoglobin, desmin, and mitochondria had been lost from skeletal, but not from the cardiac muscle, which suggested that only the skeletal muscle was damaged. Moreover, because mitochondria had disappeared only from the skeletal muscle, it was considered that skeletal muscle degeneration was caused by mitochondrial damage. Therefore, it is suggested that immunostaining of skeletal muscle by antibodies for muscle-associated proteins and mitochondria is useful to corroborate a diagnosis of NMS.

Adult↗
PubMed2001

Assessment of the effect of revascularization early after CABG using ECG-gated perfusion single-photon emission tomography.

When an arterial graft is used, reversible perfusion defects on single-photon emission tomography (SPET) perfusion images are occasionally observed early after coronary artery bypass graft surgery (CABG), owing to the restricted flow capacity. The purpose of this study was to determine whether the functional information obtained with electrocardiography (ECG)-gated perfusion SPET could be helpful in evaluating the effect of revascularization early after CABG. Twenty-three patients (18 men and 5 women, mean age 65+/-9 years) underwent stress/re-injection thallium-201 ECG-gated SPET before and 4 weeks after CABG (13 with exercise and 10 with dipyridamole). Patency of all grafts was confirmed by coronary angiography 1 month after CABG. Cardiac functional data including the left ventricular ejection fraction (LVEF) and the transient ischaemic dilatation (TID) ratio were analysed using a commercially available automated program. The conventional stress and re-injection tomograms were interpreted by means of a five-point scoring system in a nine-segment model. Stress-induced reversible 201Tl perfusion defects were present in 64% of the myocardial segments bypassed by patent arterial grafts, in contrast to 42% of the myocardial segments bypassed by patent venous grafts (chi2=7.8, P=0.005). Of the 23 patients, 12 showed improvement in summed ischaemic scores (group 1), while 11 had no change or deterioration (group 2), although all grafts were patent on postoperative catheterization. The TID ratio improved in both group 1 and group 2 before and after CABG (1.14+/-0.13 vs 0.99+/-0.07, P=0.001 and 1.09+/-0.07 vs 0.94+/-0.05, P=0.002, respectively). However, LVEF did not significantly improve in group 1 or group 2 after CABG (42.5%+/-9.9% vs 47.5%+/-11.8%, and 52.1%+/-7.5% vs 53.1%+/-5.9%, respectively). Perfusion imaging or LVEF assessment is of limited value early after CABG. The TID ratio obtained with ECG-gated perfusion SPET may be a useful marker to evaluate the effect of revascularization early after surgery.

Aged↗
PubMed2001

Histologic factors affecting prognosis following hepatectomy for intrahepatic cholangiocarcinoma.

Long-term survival following hepatectomy for intrahepatic cholangiocarcinoma has been poor, and specific factors influencing survival are unclear. In a retrospective study we sought to determine prognostic factors related to survival in these patients. In 28 patients who underwent hepatic resection for intrahepatic cholangiocarcinoma, we investigated the relations of several histologic factors to patient survival by univariate and multivariate analyses. No deaths occurred during the first 30 days. Median and mean survival times following hepatectomy were 409 and 935 days, respectively. The respective survival rates at 1, 3, and 5 years were 57%, 27%, and 27%. Resection margin status, intrahepatic metastasis, lymph node involvement, and lymphatic invasion were significant predictors of outcome. In a multivariate analysis using the Cox proportional hazards model, only lymphatic invasion independently predicted survival. Curative resection with clear margins was found to prolong survival after surgery. Hepatectomy for intrahepatic cholangiocarcinoma without lymphatic invasion offers hope for long-term survival.

Adult↗