Biomedical subjects

T Shuto

Publications and source records attributed to T Shuto.

At least 19 recordsLinked to original sources

PubMed2006

Role of adenosine A1 receptors in the modulation of dopamine D1 and adenosine A2A receptor signaling in the neostriatum.

Adenosine is known to modulate the function of neostriatal neurons. Adenosine acting on A(2A) receptors increases the phosphorylation of dopamine- and cAMP-regulated phosphoprotein of M(r) 32 kDa (DARPP-32) at Thr34 (the cAMP-dependent protein kinase [PKA] site) in striatopallidal neurons, and opposes dopamine D2 receptor signaling. In contrast, the role of adenosine A(1) receptors in the regulation of dopamine/DARPP-32 signaling is not clearly understood. Here, we investigated the effect of adenosine A(1) receptors on D(1), D(2) and A(2A) receptor signaling using mouse neostriatal slices. An A(1) receptor agonist, 2-chloro-N(6)-cyclopentyladenosine (100 nM), caused a transient increase, followed by a transient decrease, in DARPP-32 Thr34 phosphorylation. Our data support the following model for the actions of the A(1) receptor agonist. The A(1) receptor-induced early increase in Thr34 phosphorylation was mediated by presynaptic inhibition of dopamine release, and the subsequent removal of tonic inhibition by D(2) receptors of A(2A) receptor/G(olf)/cAMP/PKA signaling. The A(1) receptor-induced late decrease in Thr34 phosphorylation was mediated by a postsynaptic G(i) mechanism, resulting in inhibition of D(1) and A(2A) receptor-coupled G(olf)/cAMP/PKA signaling in direct and indirect pathway neurons, respectively. In conclusion, A(1) receptors play a major modulatory role in dopamine and adenosine receptor signaling.

Adenosine↗

PubMed2005

Recurrence rate and transplantability after liver resection in patients with hepatocellular carcinoma who initially met transplantation criteria.

To understand the recurrence rate and transplantability after liver resection (LR), which are essential factors to predict the prognosis of initial resection and salvage transplantation for hepatocellular carcinoma (HCC), we reviewed the clinical records of 279 consecutive HCC patients who met the Milan criteria and underwent LR between 1990 and 2000. Recurrence-free survival rates after 1, 2, 3, 5, and 10 years following LR were 84%, 62%, 49%, 29%, and 17%, respectively. Multivariate analysis using clinical factors such as age, sex, histological differentiation, serum levels of alpha-fetoprotein and 7S domain of type IV collagen (7S collagen), platelet counts, indocyanin green retention test after 15 minutes, and type of LR (resection of one or more segments, or less than one segment) revealed 7S collagen to be a independent factor that significantly affects recurrence-free survival. Yearly recurrence rates up to 5 years after resection ranged from 14% to 27%, averaging 20%. Concerning 169 patients who underwent tests for 7S collagen, the average yearly recurrence rate (27%) in patients with 7S collagen levels 8.0 ng/mL or higher was remarkably greater than that in the patients with levels less than 8.0 ng/mL (16%). The transplantability rate at the time of recurrence meeting the Milan criteria was roughly 60%. There were no pre-LR factors that significantly predicted transplantability. This result indicates that patients with lower 7S collagen levels are more eligible for initial LR and then salvage LT rather than primary LT.

Adult↗

PubMed2004

Repeated gamma knife radiosurgery for multiple metastatic brain tumours.

BACKGROUND: The effectiveness of repeated gamma knife radiosurgery (GKS) for the treatment of multiple metastatic brain tumours was evaluated. METHODS: This study included 16 patients with 242 tumours, 10 men and 6 women with a mean age of 60.3 years at initial GKS, who underwent GKS four times or more for newly developed metastatic tumours. FINDINGS: Sixteen patients underwent a total of 83 GKS procedures (range 4 to 8, mean 5.2). The mean number of metastases at each GKS procedure was 2.9 and the number of tumours tended to increase at the 5th GKS procedure compared with the 1st, but not significantly. The mean interval between each procedure was 4.8 months and was not significantly different. Median survival was 22.4 months (range 9.4-78.9 months) and the primary site was not correlated with survival time. The total number of treated tumours tended to correlate to survival time, but not significantly. Use of adjuvant whole brain radiation also had no significant effect on survival time. The Karnofsky performance status was maintained at more than 70 in most patients, but decreased significantly between initial and final GKS. Death due to progression of brain lesions occurred in only about 30% of patients regardless of the multiple newly developed brain metastases. CONCLUSIONS: Repeated radiosurgery for brain metastases is effective and relatively long survival can be expected in some patients associated with a low risk of radiation-induced injury.

Adult↗

PubMed2003

Cytokeratin-19 fragments in serum (CYFRA 21-1) as a marker in primary liver cancer.

Using an electrochemiluminescence immunoassay, CYFRA 21-1 concentrations were measured in sera from 187 patients with primary liver cancer (164 with hepatocellular carcinoma (HCC) and 23 with intrahepatic cholangiocarcinoma (ICC)) and 87 patients with benign liver diseases. Concentrations of CYFRA 21-1 were significantly higher in patients with ICC (5.0; interquartile range 3.1-10.7 ng ml(-1)) than in those with benign liver disease (1.4; 1.0-1.9; Mann-Whitney U-test, P<0.0001) or HCC (1.7; 1.1-2.7; Mann-Whitney U-test, P<0.0001). Using cutoff values selected for 95% specificity in the benign group (3.0 ng ml(-1)), CYFRA 21-1 showed higher sensitivity for ICC (87.0%) than three commonly used markers including alpha-fetoprotein (17.4%), carcinoembryonic antigen (34.8%), and carbohydrate antigen 19-9 (60.9%). Serum CYFRA 21-1 increased in ICC from stages I/II to IV (Kruskal-Wallis test, P=0.0102). CYFRA 21-1 concentration increased with extent of local invasion, but not nodal status. Serum CYFRA 21-1 represents a useful diagnostic test for ICC that offers high sensitivity. CYFRA 21-1 reflected differences in tumour burden, suggesting applicability to staging and follow-up.

Adult↗

PubMed2003

Gamma knife radiosurgery for metastatic tumours in the brain stem.

BACKGROUND: Stereotactic radiosurgery has become important in the treatment of metastatic brain tumours and is often the first choice modality for eloquent or deep locations such as the brain stem. This study evaluated the efficacy of gamma knife radiosurgery (GKS) for the treatment of brain stem metastases. METHODS: The medical records of 25 patients with 31 tumours, 11 men and 14 women aged 42 to 78 years (mean 57.1 years), who underwent GKS for metastatic tumours in the brain stem were retrospectively reviewed. The results of GKS were evaluated according to the change in tumour size on neuro-imaging. FINDINGS: The most common location of the primary malignancy was the lung followed by the breast. Adenocarcinoma was found in 19 patients (24 lesions). No case of squamous cell carcinoma was found. The mean calculated tumour volume was 2.1 cm(3) and the mean prescription dose to the tumour margin was 13.0 Gy. Mean duration of neuro-imaging follow up was 5.2 months and the overall tumour control rate was 77.4%. There was a significant correlation between the marginal dose delivered and the effect on neuro-imaging. New radiation-induced injury in the surrounding brain occurred in only 2 patients. INTERPRETATION: GKS for brain stem metastases using a marginal dose of 15 Gy or less is effective and relatively safe. Accurate targeting of the tumour and safe dose planning are essential to obtain satisfactory results with GKS for brain stem metastases.

Adenocarcinoma↗

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

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

Fibroblasts from the inner granulation tissue of the pseudocapsule in hips at revision arthroplasty induce osteoclast differentiation, as do stromal cells.

BACKGROUND: It has previously been shown that many osteoclast precursors are included in the granulation tissue within the pseudocapsule obtained at revision arthroplasty from hips with osteolysis. In vitro culture of only cells isolated from the granulation tissue has been previously shown to generate many mature osteoclasts. OBJECTIVE: To investigate the presence or otherwise of supporting cells, similar to stromal cells, which differentiate osteoclasts within the granulation tissue. METHODS: Cells isolated from the granulation tissue were cultured alone, and after four weeks fibroblast-like cells (granulation fibroblasts) remained. Rat non-adherent bone marrow cells (NA-BMCs) were co-cultured with the granulation fibroblasts with or without 1alpha,25(OH)2D3 (10(-8) M) or heat treated ROS 17/2.8 cell conditioned medium (ht ROSCM), or both. Multinucleated cells (MNCs), which formed, were assessed by biochemical and functional characterisation of osteoclasts. Receptor activator of NFkappaB ligand (RANKL) was investigated by immunohistochemistry. RESULTS: Co-culture of NA-BMCs and granulation fibroblasts caused the formation of tartrate resistant acid phosphatase (TRAP) positive MNCs, which had the calcitonin receptor (CTR), the Kat-1 antigen, which is specific to the surface of rat osteoclasts, and the ability to form pits in the presence of both 1alpha,25(OH)2D3 and ht ROSCM or in the presence of just ht ROSCM. RANKL was detected in fibroblast-like cells in the granulation tissue. CONCLUSION: These data suggest that granulation fibroblasts support osteoclast differentiation, as do osteoblasts/stromal cells, and may play a part in aseptic loosening.

Aged↗

PubMed2001

Activation of NF-kappa B by nontypeable Hemophilus influenzae is mediated by toll-like receptor 2-TAK1-dependent NIK-IKK alpha /beta-I kappa B alpha and MKK3/6-p38 MAP kinase signaling pathways in epithelial cells.

Nontypeable Hemophilus influenzae (NTHi) is an important human pathogen in both children and adults. In children, it causes otitis media, the most common childhood infection and the leading cause of conductive hearing loss in the United States. In adults, it causes lower respiratory tract infections in the setting of chronic obstructive pulmonary disease, the fourth leading cause of death in the United States. The molecular mechanisms underlying the pathogenesis of NTHi-induced infections remain undefined, but they may involve activation of NF-kappa B, a transcriptional activator of multiple host defense genes involved in immune and inflammatory responses. Here, we show that NTHi strongly activates NF-kappa B in human epithelial cells via two distinct signaling pathways, NF-kappa B translocation-dependent and -independent pathways. The NF-kappa B translocation-dependent pathway involves activation of NF-kappa B inducing kinase (NIK)--IKK alpha/beta complex leading to I kappa B alpha phosphorylation and degradation, whereas the NF-kappa B translocation-independent pathway involves activation of MKK3/6--p38 mitogen-activated protein (MAP) kinase pathway. Bifurcation of NTHi-induced NIK-IKK alpha/beta-I kappa B alpha and MKK3/6--p38 MAP kinase pathways may occur at transforming growth factor-beta activated kinase 1 (TAK1). Furthermore, we show that toll-like receptor 2 (TLR2) is required for NTHi-induced NF-kappa B activation. In addition, several key inflammatory mediators including IL-1 beta, IL-8, and tumor necrosis factor-alpha are up-regulated by NTHi. Finally, P6, a 16-kDa lipoprotein highly conserved in the outer membrane of all NTHi and H. influenzae type b strains, appears to also activate NF-kappa B via similar signaling pathways. Taken together, our results demonstrate that NTHi activates NF-kappa B via TLR2-TAK1-dependent NIK--IKK alpha/beta-I kappa B alpha and MKK3/6--p38 MAP kinase signaling pathways. These studies may bring new insights into molecular pathogenesis of NTHi-induced infections and open up new therapeutic targets for these diseases.

Calcium-Calmodulin-Dependent Protein Kinases↗

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

IL-6 up-regulates CNTF mRNA expression and enhances neurite regeneration.

Interleukin-6 (IL-6) is a neurotrophic cytokine, however, its direct effect on nerve regeneration has not been well characterized. We therefore examined the effect of IL-6 on neurite regeneration using the rat dorsal root ganglion. IL-6 significantly enhanced neurite regeneration from transected nerve terminals. We also examined the mRNA expression of IL-6 family cytokines and their receptors during the regeneration. The mRNA expressions of IL-6, IL-6 receptor, leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF) receptor alpha, and LIF receptor beta showed no significant differences by the addition of IL-6. In contrast, IL-6 enhanced the mRNA expression of gp130 and CNTF. In addition, CNTF significantly increased neurite regeneration when added exogenously. Our data suggest that IL-6 enhanced regeneration via up-regulating CNTF expression.

Animals↗

PubMed2001

Subchondral changes in transient osteoporosis of the hip.

OBJECTIVE: To review the subchondral changes on MR imaging in transient osteoporosis of the hip (TOH) and to consider the pathophysiology. DESIGN AND PATIENTS: MR images of 12 hips of 11 consecutive patients with TOH were retrospectively studied. The diagnoses of TOH were confirmed on the basis of previously published criteria, including decreased bone density of the femoral head and/or neck on radiographs, bone marrow edema (BME) pattern on MR images, spontaneous resolution of the symptoms and a return to normal radiodensity. RESULTS: All 12 hips showed a BME pattern in the femoral head and/or neck. Linear patterns of very low signal intensity were identified on T1-weighted images in the subchondral area within the diffuse low signal intensity area in all 12 hips. On T2-weighted images, a low signal intensity line was observed in the corresponding area in eight hips only. These linear patterns were thought to represent subchondral fracture lines. CONCLUSIONS: The presence of a subchondral fracture may be important when considering the pathophysiology of TOH.

Adult↗

PubMed2001

Prognostic factors after recurrence of resected hepatocellular carcinoma associated with hepatitis C virus.

To clarify the variables related to survival after recurrence of resected hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV), we studied 17 clinicopathological factors in 99 patients with recurrence of HCC associated with HCV infection after hepatic resection. The 1-, 3-, and 5-year survival rates after first resection in these patients were 91%, 81%, and 49%, while after recurrence they were 81%, 51%, and 29%, respectively. Multivariate analysis showed that the following six variables were independent prognostic factors after recurrence: platelet count, albumin level, bilirubin level, number of hepatic lesions, distant metastasis, and any treatment at recurrence. A correlation between second hepatic resection (SHR) and liver function tests was seen in regard to albumin and total bilirubin values at recurrence. Indeed, hepatic function and progression of intrahepatic tumors at recurrence were significant prognostic factors after recurrence of HCC associated with HCV infection, while any treatment at recurrence was also a significant prognostic factor. Therefore, in order to improve prognosis after recurrence, we should actively treat the recurrent hepatic lesions whenever possible.

Carcinoma, Hepatocellular↗

PubMed2001

Renal pelvic carcinoma producing granulocyte colony-stimulating factor: report of a case.

A 69-year-old man was admitted to our hospital because of anorexia and weight loss. Abdominal computed tomography showed an irregularly contoured mass in his left renal pelvis. The patient had a remarkable degree of leukocytosis with no obvious focus of infection. An enzyme immunoassay of the serum revealed a remarkably high concentration of granulocyte colony-stimulating factor (G-CSF). The patient died 6 weeks after admission without a resection of the renal pelvic tumor. At autopsy, the tumor involved the pancreas, stomach, and descending colon. The histopathologic diagnosis was squamous cell carcinoma with sarcomatous change. Immunohistochemical staining using anti-G-CSF antibody demonstrated immunoreactivity in the cancer cells. To our knowledge, this is the first case of renal pelvic carcinoma proven to produce G-CSF reported in English.

Aged↗

PubMed2001

Pleural dissemination as a complication of preoperative percutaneous transhepatic biliary drainage for hilar cholangiocarcinoma: report of a case.

One potential risk of percutaneous transhepatic biliary drainage is tumor seeding along the catheter tract. A 57-year-old woman with obstructive jaundice due to hilar cholangiocarcinoma underwent an extended left hepatic lobectomy, a regional lymph node dissection, and a right hepaticojejunostomy 2 weeks after percutaneous transhepatic biliary drainage. Multiple right pleural masses were found on a chest radiogram 14 months after the operation. No recurrent lesions were detected in the abdominal cavity. A right panpleuropneumonectomy was performed; however, the patient died of respiratory failure due to tumor recurrence 9 months after the second operation. Preoperative percutaneous transhepatich biliary drainage was considered to have resulted in pleural implantation.

Cholangiocarcinoma↗

PubMed2001

Heterogeneity of hepatic parenchymal enhancement on computed tomography during arterial portography: quantitative analysis of correlation with severity of hepatic fibrosis.

Background/Aims: In patients with chronic liver disease, heterogeneous enhancement of liver parenchyma is often noted on computed tomography during arterial portography (CTAP). We investigated the factors contributing to the heterogeneous enhancement and its relationship with postoperative histopathological findings. Methodology: Eighty-seven patients who had undergone a right lobectomy for liver tumor after CTAP were evaluated. The heterogeneity of hepatic parenchymal enhancement on CTAP was assessed quantitatively using standard deviation of mean CT numbers for five ROIs (S.D.) set in the right hepatic lobe, and comparatively evaluated among three histological groups (liver cirrhosis (LC, n=41), chronic hepatitis (CH, n=33), and normal liver (Normal, n=13)). Severity of fibrosis and degree of splenomegaly (Sp) were taken up as factors contributory to the heterogeneity, and were assessed for correlation with the S.D. Results: The range (mean) of S.D. was LC, 3.07-17.64 (9.10); CH, 1.83-11.12 (6.77); and Normal, 2.06-8.89 (5.64) (Scheffe's F-test: LC vs CH, P<0.0005; LC vs Normal, P<0.0002). The higher fibrosis group exhibited significantly greater S.D. values as compared with the lower fibrosis group (Scheffe's F-test: P<0.00003). Coefficient of correlation between the S.D. and the Sp was 0.295 (P<0.005). Conclusion: There was a fair possibility of LC in patients with heterogeneous enhancement of liver parenchyma on CTAP. The severity of liver fibrosis and the degree of splenomegaly were considered to be factors contributing to the heterogeneous enhancement.

Journal Article↗

PubMed2001

Previous or occult hepatitis B virus infection in hepatitis C virus-associated hepatocellular carcinoma without hepatic fibrosis.

We investigated the role of hepatitis B virus infection in development of hepatocellular carcinoma in hepatitis C virus-infected patients without hepatic fibrosis. Of 253 patients, 8 lacked hepatic fibrosis (group 1); group 2 included the remaining 245 patients. Clinicopathologic findings were compared between the groups. Hepatitis B x gene was sought in cancers and adjoining noncancerous liver. Group 1 showed better liver function parameters and milder active hepatitis than group 2. The proportion of patients with anti-hepatitis B virus antibody tended to be higher in group 1 than in group 2. The proportion of patients with hepatitis B x RNA in cancers was significantly higher in group 1 than in group 2. All group 1 patients had previous or occult hepatitis B virus infection. Previous or occult hepatitis B virus infection may be critical in development of hepatocellular carcinomas in hepatitis C virus-infected patients without hepatic fibrosis.

Aged↗

PubMed2001

Reactivation of viral replication after liver resection in patients infected with hepatitis B virus.

OBJECTIVE: To investigate the mechanisms and risk factors underlying postoperative reactivation of hepatitis after liver resection for hepatitis B virus-related hepatocellular carcinoma. SUMMARY BACKGROUND DATA: Although risk factors for acute hepatic failure after liver resection have been reported in patients with chronic liver disease, the issue of reactivation of hepatitis B virus replication after liver resection is unresolved. METHODS: Fifty-five patients with hepatocellular carcinoma and hepatitis B surface antigen underwent liver resection. In 25 of these 55 patients, serum levels of hepatitis B virus DNA and the type of hepatitis B virus were determined before and after surgery. RESULTS: Postoperative hepatitis occurred in 13 of the 55 patients (24%). Reactivation of viral replication occurred after liver resection in 7 of the 25 patients tested, and alanine aminotransferase activity increased in 6 of these 7 patients. High preoperative alanine aminotransferase activity, high levels of hepatitis B virus DNA, presence of wild-type DNA, and detection of hepatitis B core antigen in hepatocytes, all features of the immune clearance phase in the natural course of hepatitis B virus infection with no surgery, were more likely to be found in patients with reactivation than in patients without reactivation. CONCLUSIONS: During the immune clearance phase of hepatitis B virus infection, especially the period of acute exacerbation, changes in serum hepatitis B virus DNA level should be monitored for early warnings of reactivation of viral replication, likely to cause severe postoperative hepatitis and acute hepatic failure.

Adult↗