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Biomedical subjects

Takatsugu Yamamoto

Publications and source records attributed to Takatsugu Yamamoto.

At least 19 recordsLinked to original sources
PubMed2006

Influence of interferon therapy on outcome after surgery for hepatitis C virus-related hepatocellular carcinoma.

Influence of interferon (IFN) therapy on postoperative outcomes in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) is still inconclusive. Of 518 patients who underwent hepatic resection for HCV-related HCC, 312 patients with Japan integrated staging score 0-2 were included in this study. Of 50 patients underwent IFN therapy, 29 patients who obtained a normalized alanine aminotransferase (ALT) activity irrespective of disappearance of serum HCV RNA were classified as the response group, while 21 patients were classified as the non-response group because their ALT activities were not normalized and serum HCV RNA persisted. The non-IFN group included 262 patients who had not received IFN therapy. The tumor-free and the overall survival rates for patients in the response group were significantly higher than those in other groups. Only one patient in the response group died of HCC recurrence, and the proportion of deaths associated with liver disease (HCC recurrence or cirrhosis) was significantly lower in the response group than other two groups. IFN therapy can improve postoperative outcomes in patients with HCV-related HCC because of suppression of recurrence and preventing progress of cirrhosis, especially when IFN therapy has controlled their active hepatitis.

Journal Article↗
PubMed2006

Reliability of rapid urinary test for antibody to Helicobacter pylori in adult patients with proteinuria.

A urinary test for detecting the anti-H. pylori antibody using immunochromatography (RAPIRAN) is considered suitable for the screening purpose. However, this may yield spurious results in the presence of proteinuria. The present study was conducted to evaluate the diagnostic performance of RAPIRAN in patients with proteinuria. Urine and serum samples of adult inpatients with proteinuria were used for analyses. The diagnosis of H. pylori infection was made based on the seropositivity of anti-H. pylori antibody using 2 different serum tests. Fifty-one subjects were eligible for analyses. The serum tests showed negative and positive in 25 and 26 patients, respectively. Two of 25 seropositive patients had a negative result in RAPIRAN, and 1 provided invalid data. All of seronegative patients showed negative in RAPIRAN. The overall accuracy was 95.0%. The present study showed that RAPIRAN has diagnostic quality enough to use clinically also in patients with proteinuria.

Adult↗
PubMed2006

Clinical significance of serum cytokeratin-19 fragment (CYFRA 21-1) in hepatocellular carcinoma.

BACKGROUND/PURPOSE: CYFRA 21-1, a soluble fragment of cytokeratin 19, is increased in serum in some patients with hepatocellular carcinoma, but the clinical significance of this increase is still unknown. METHODS: Serum concentrations of CYFRA 21-1 were measured in 240 patients with hepatocellular carcinoma prior to hepatic resection. The relationships between serum CYFRA 21-1 concentrations and clinicopathologic features were analyzed. RESULTS: The sensitivity of CYFRA 21-1 as a test for hepatocellular carcinoma was 18.8%. Serum CYFRA 21-1 was significantly higher in patients with portal vein tumor thrombus, and serum CYFRA 21-1 increased with the progression of portal vein tumor thrombus. Tumor size was related to serum CYFRA 21-1, but there were no significant correlations between serum CYFRA 21-1 concentrations and tumor differentiation or number of tumors. Although patients with stage IV tumor had significantly higher CYFRA 21-1 concentrations than those with stages I, II, and III, CYFRA 21-1 was not associated with postoperative prognosis. CONCLUSIONS: Although high concentrations of CYFRA 21-1 were often detected in patients with a tumor diameter greater than 5 cm or tumor thrombus in the major portal vein, CYFRA 21-1 is not a useful diagnostic tool for hepatocellular carcinoma because of its low sensitivity.

Adult↗
PubMed2006

Clinicopathological implications of immunohistochemically demonstrated mucin core protein expression in hepatocellular carcinoma.

METHODS: We examined the expression of mucin core protein 1 (MUC1) immunohistochemically in 186 surgical specimens of histopathologically nonmucinous hepatocellular carcinoma (HCC) and compared the clinicopathological features in patients with MUC1-positive HCC (MUC1-positive group) with those in patients with MUC1-negative HCC (MUC1-negative group). RESULTS: MUC1 immunoreactively was present in 85 of the 186 HCCs. Of the clinicopathological variables examined, the serum concentration of alpha-fetoprotein, tumor differentiation, bile duct invasion, lymph node metastasis, and cytokeratin 19 expression exhibited significant associations with MUC1 expression. Although cumulative and tumor-free survival rates were not different between the two groups, the percentage of patients with first recurrence of HCC in distant organs (distant metastasis) within 2 years after surgery was significantly higher in the MUC1-positive group than in the MUC1-negative group (P = 0.0104). The risk ratio of MUC1 positivity for this type of distant metastasis was 3.156 (95% confidence interval, 1.064-9.358). CONCLUSIONS: In patients with MUC1-positive HCC, careful follow-up is necessary, not only for intrahepatic recurrence but also for distant metastasis, after the resection of primary HCC.

Adult↗
PubMed2006

Immunohistochemical demonstration of c-Kit protooncogene product in gallbladder cancer.

BACKGROUND/PURPOSE: Although some gallbladder carcinomas are immunoreactive for c-Kit, the reasons for the c-Kit expression and its clinicopathologic implications are unknown. METHODS: We investigated the prevalence of c-Kit immunoreactivity, its clinicopathologic correlates (including microvessel density and postoperative outcome), and the possible mechanisms of c-Kit expression. We reviewed retrospectively, the clinicopathologic records of 47 patients who had undergone macroscopically complete gallbladder carcinoma resection. The numbers of patients at pathologic stages I to IV, according to current TNM-based staging, were 10, 5, 18, and 14, respectively. For immunohistochemical examination, we used monoclonal antibodies against c-Kit and CD 34 (progenitor cell markers), cytokeratin 7 and cytokeratin 19 (cholangiocyte markers), and OCH1E5 (a hepatocyte marker). Control tissue samples were from five gallbladder specimens each with chronic cholecystitis, polyp, and adenoma. RESULTS: Cytoplasmic immunostaining for c-Kit was detected in 21 of the 47 gallbladder carcinomas (45%), and in 1 of the 15 control specimens (diagnosis, chronic cholecystitis). Young age was significantly associated with c-Kit positivity; however, there were no significant differences in the incidence of c-Kit positivity among other variables, including tumor stage and outcome. However, microvessel density was significantly higher in c-Kit-positive gallbladder carcinoma compared with c-Kit-negative gallbladder carcinoma. None of the 47 cancer specimens or the 15 control specimens were stained for CD34 and OCH1E5, but all 47 cancer specimens were stained for cytokeratins 7 and 19. CONCLUSIONS: Gallbladder carcinomas positive for c-Kit are unlikely to arise from immature cells, but may be associated with neovascularization. Angiogenesis inhibitors, such as tyrosine kinase inhibitors, therefore, may suppress the growth of some gallbladder cancers.

Adult↗
PubMed2006

Assessment of the gastric emptying velocity by the 13C-octanoate breath test: deconvolution versus a Wagner-Nelson analysis.

BACKGROUND: The dynamic change in gastric emptying on a minute-by-minute basis (gastric velocity) is evaluated by the 13C-octanoate breath test with deconvolution analysis. However, deconvolution is impractical, because it requires dual experiments to obtain 13CO2 excretion profiles following intraduodenal and oral administration of 13C-octanoate. We investigated whether the Wagner-Nelson method, used in drug absorption studies, can determine the velocity profile based on a single experiment as accurately as deconvolution, and whether the velocity assessed by the Wagner-Nelson method is sensitive enough to detect subtle changes in gastric emptying induced by butylscopolamine. METHODS: Five male volunteers underwent a 4-h breath test twice, after intraduodenal administration of 20 ml normal saline containing 100 mg 13C-octanoate and after ingestion of a 320-kcal muffin containing 100 mg 13C-octanoate. Deconvolution determined the velocity profile by subtracting duodenal from oral data, and the Wagner-Nelson method produced it from only oral data. The velocity profiles were compared between the two methods. Another six male subjects underwent the breath test by ingesting a muffin twice, once with and once without 20 mg oral butylscopolamine. The velocity profiles generated by the Wagner-Nelson analysis and the conventional 13CO2 excretion curves were compared between the two occasions. RESULTS: The two techniques yielded identical velocity profiles. The velocity profile detected a significant change in the emptying pattern induced by butylscopolamine (initial acceleration with subsequent deceleration), while the conventional breath curves failed to detect this change. CONCLUSIONS: Velocity assessment by a Wagner-Nelson analysis can precisely describe altered gastric emptying, based on a single experiment.

Adult↗
PubMed2006

Hepatocellular carcinoma arising from nonalcoholic steatohepatitis: report of two cases.

Sporadic cases of hepatocellular carcinoma (HCC) originating from nonalcoholic steatohepatitis (NASH) have recently been reported. Thus, we investigated the prevalence of NASH in patients with HCC. A review of the clinical records of 481 patients who underwent liver resection for HCC in our department between January 1991 and December 2003 revealed only two (0.4%) patients with HCC associated with NASH. Both of these patients had noninsulin-dependent diabetes mellitus, and neither had a history of alcohol consumption or blood transfusion. All serologic markers for hepatitis B and C viruses were negative. Histological examination of the noncancerous hepatic tissue revealed NASH with moderate hepatic fibrosis in one patient and cirrhosis in the other. Thus, clinical follow-up and screening for HCC should be done for patients with hepatic fibrosis caused by NASH, even though this form of hepatitis is an uncommon cause of HCC.

Aged↗
PubMed2006

Comparison between gastric scintigraphy and the [13C]-acetate breath test with Wagner-Nelson analysis in humans.

1. The [(13)C]-acetate breath test (ABT) quantifies gastric emptying as the half [(13)CO(2)]-excretion time (T(1/2b)), but T(1/2b) differs from the scintigraphic half-emptying time (T(1/2s)). The aims of the present study were to accurately determine the half-emptying time by ABT with Wagner-Nelson analysis (T(1/2WN)), to compare T(1/2WN) with T(1/2s) and to validate the Wagner-Nelson strategy in ABT. 2. For a comparative study, eight volunteers simultaneously underwent ABT and scintigraphy. Anterior images were acquired and breath samples were collected every 15 min for 4.0 h after ingestion of a 200 kcal liquid meal labelled with 37 MBq [(99m)Tc]-colloidal sulphur and 100 mg [(13)C]-acetate. For the validation experiment, another six volunteers underwent ABT, on two randomized occasions, using the 200 kcal liquid meal with 100 mg [(13)C]-acetate. On either of the two occasions, a gel-forming agent was stirred into the meal to intentionally delay gastric emptying by increasing meal viscosity. Breath samples were collected at regular 15 min intervals for 4 h post ingestion. 3. The Wagner-Nelson equation for ABT is F(t) = (A(breath)(t) + C(t)/0.65)/A(breath)(infinity), where F(t) is a fractional dose of the [(13)C] label emptied, C(t) is the [(13)CO(2)] excretion (% dose/h), A(breath)(t) is the area under the C(t) curve (% dose) and A(breath)(infinity) is the ultimate [(13)CO(2)] recovery in breath (% dose). The percentage gastric retention was estimated as 100 x (1 - F(t)). The time plots of scintigraphic activity and 100 x (1 - F(t)) were fitted to y(t) = 100 x e(-Kxt), K values were estimated mathematically for each plot by regression analysis and T(1/2s) and T(1/2WN) were calculated as (ln2)/K. The time versus pulmonary [(13)CO(2)] excretion plots were fitted to z(t) = m x k x beta x e(-kt)(1 - e(-kxt))(beta-1), where m, k and beta are constants; T(1/2b) was calculated as -(ln(1 - 2(-1/beta))]/k. 4. Values of T(1/2WN) were closer to T(1/2s) than T(1/2b), although T(1/2WN) and T(1/2b) yielded significant under- and overestimation of T(1/2s), respectively. The high viscosity meal significantly prolonged T(1/2WN) and T(1/2b); T(1/2WN) could detect the delayed transit of the viscous meal more sensitively than T(1/2b). 5. The Wagner-Nelson method improves the accuracy of the ABT.

Acetates↗
PubMed2006

Influence of surface roughness on crack formation in a glass-ceramic bonded to a resin composite base.

The objective of the present study was to assess the influence of the roughness of a loaded surface on crack formation in a mica-based glass-ceramic bonded to a resin composite base. Five different surface roughnesses were created on glass-ceramic discs by serial wet-grinding with silicone carbide abrasives. The thicknesses of the ceramic discs were 1.50 +/- 0.01 mm. Resin composite discs were bonded to the ceramic surfaces opposite to the ground surfaces using an adhesive resin composite cement and a silane coupling agent. A compressive load was then applied at the center of the ground ceramic surface. The loads at initial radial and cone crack formations in the ceramic were measured macroscopically. In three of the five groups, the initial radial crack formations could not be observed due to the high roughness of these surfaces. Statistical analysis was performed using Student's t test for initial radial cracks and one-way ANOVA for the cone cracks. There were no significant differences between the two groups for the initial radial cracks or among the five groups for the cone cracks (P < 0.05). The roughness of the loaded surface had no influence on crack formation in the bonded mica-based glass-ceramic.

Aluminum Silicates↗
PubMed2005

Immunohistologic attempt to find carcinogenesis from hepatic progenitor cell in hepatocellular carcinoma.

AIM: To clarify whether hepatocellular carcinoma (HCC) originates from hepatic progenitor cells and whether there is any correlation with the clinicopathologic factors of HCC, we reviewed 217 resected HCC specimens. METHODS: Immunohistochemical examination of cytokeratin (CK) 7, CK19, CD34, and CD117 (c-KIT) was performed. Overexpression of CK7 and CK19 indicates differentiation from cholangiocellular and hepatic progenitor cells, while overexpression of CD34 and CD117 indicates hepatic stem cells. Fresh specimens were obtained from 20 HCC patients for mutation of the c-KIT gene. RESULTS: CK7, CK19, and CD117 were positive in 41, 9.7, and 0.9% of the HCC specimens, respectively, and CD34 was never positive. None of the fresh HCC specimens demonstrated a c-KIT mutation. CK19 positivity was significantly correlated with a positive hepatitis B core antibody, and with poor survival outcome, and tended to correlate with poor histologic differentiation. CONCLUSION: These results suggest that: (i) about 10% of HCCs with typical histologic features originate from an intermediate hepatic progenitor cell, such as the canal of Hering and oval cells in the rat, or acquire the characteristics of cholangiocellular epithelium by metaplasia; (ii) HCC with typical histologic features rarely originates from hepatic stem cells, and (iii) patients with CK19-positive HCC have a poor prognosis.

Analysis of Variance↗
PubMed2005

Marginal toughness of bonded dental ceramics evaluated by determination of the crack length.

OBJECTIVES: The objective of this study was to evaluate the toughness of dental ceramics near a bonded interface using indentation microfracture. METHODS: The ceramics used in the present study were two leucite-reinforced ceramics (IPS Empress and Finesse), one lithia-based ceramic (IPS Empress 2) and one mica-based ceramic (OCC). The ceramic discs were processed according to the manufacturers instructions and were bonded to resinous discs using a resin composite cement. The bonded specimens were sectioned perpendicularly, and micro-Vickers indentations were imprinted at several distances from the bonded interface in the polished ceramic sections. The lengths between the two ends of the radial cracks along the bonded interface were measured. RESULTS: Crack lengthening was recognized when the distance was within 70 microm. In each ceramic, the indentation crack length at 40 microm from the interface was significantly longer than the length at the inner point of the ceramic material (p<0.05). The order of the mean indentation crack lengths at 40 microm was OCC>Finesse>IPS Empress 2>IPS Empress, while the order at 490 microm was Finesse>OCC>IPS Empress>IPS Empress 2. There was a difference between the orders at 40 microm and at 490 microm. SIGNIFICANCE: The behaviour of the indentation crack near the interface differs from that which is distant from the interface. Therefore, it is impossible to estimate the marginal toughness of the ceramic based on the indentation microfracture at the inner point of the ceramic.

Acrylic Resins↗
PubMed2005

Alcohol abuse as an etiologic factor for hepatocellular carcinoma in Japan.

The etiologic role of alcoholic liver disease for hepatocellular carcinoma is uncertain. To assess the role of alcoholic liver disease on the development of carcinoma, we examined history of alcohol abuse and viral markers in the sera and/or resected specimens in 454 patients who underwent liver resection for hepatocellular carcinoma. Sera from 20 of the 454 patients were negative for hepatitis B, C, and D viruses. Of the 20 patients, one patient had autoimmune hepatitis, one had primary biliary cirrhosis, two had non-alcoholic steatohepatitis. Of the remaining 16 patients, 8 patients were alcohol abusers and 5 of the 8 patients were heavy alcohol abusers. Hepatitis G virus was not detected in sera form the 16 patients. Although hepatitis B x gene was detected in the cancerous and/or non-cancerous tissues in all three alcohol abusers but not heavy abusers and in 5 of 6 non-alcohol abusers whose surgical specimens were available, the gene was detected in only one of the five heavy alcohol abusers. The five heavy alcohol abusers had advanced hepatic fibrosis and active hepatitis. Alcoholic liver disease with advanced hepatic fibrosis and active hepatitis is a possible cause for the development of hepatocellular carcinoma.

Journal Article↗
PubMed2005

Reliability of urinary tests for antibody to Helicobacter pylori in patients with pulmonary tuberculosis.

AIM: Although the quality of currently available urinary tests for detecting antibody to Helicobacter pylori (H pylori) have been proved in some populations, the accuracy has not been studied regarding patients who suffer from pulmonary tuberculosis with multi-drug treatments. The present study was conducted to evaluate the accuracy of these urinary tests for antibody to H pylori in these patients. METHODS: Serum samples from 61 inpatients with pulmonary tuberculosis were tested using enzyme immunoassay, and urine samples were assayed by enzyme-linked immunosorbent assay method (URINELISA) and immunochromatography method (RAPIRAN). Medicines prescribed to the patients were recorded for medical charts, to evaluate the influences on the results of urinary tests. RESULTS: The sensitivity, specificity, and consistency of URINELISA against the serum test were 93.1%, 65.6%, and 78.6% respectively, and those of RAPIRAN were 86.2%, 93.7%, and 90.1% respectively, which were almost equal to the data previously reported. Prescribed medicines had little influence on the results. CONCLUSION: The two urinary tests for detecting H pylori antibody have a diagnostic accuracy in patients with pulmonary tuberculosis given multiple anti-tuberculosis drugs.

Adult↗
PubMed2005

Serosal invasion in TNM staging of mass-forming intrahepatic cholangiocarcinoma.

BACKGROUND/PURPOSE: The Liver Cancer Study Group of Japan established a tumor-nodule-metastasis (TNM) staging system for mass-forming intrahepatic cholangiocarcinoma, with T determined by tumor number and size and vascular or serosal invasion. Serosal invasion is not considered in the designation established by the International Union Against Cancer. METHODS: Sixty-three patients who underwent hepatic resection for mass-forming intrahepatic cholangiocarcinoma were investigated retrospectively, with the investigation including univariate and multivariate analyses of potential prognostic factors. RESULTS: By log-rank test, tumor size more than 3.0 cm, vascular invasion, lymph node metastasis, intrahepatic metastasis, and involved resection margin, but not serosal invasion, were associated significantly with poor prognosis. Even in patients with serosal invasion, the postoperative outcome was much better in those without than in those with vascular invasion. Multivariate analysis identified vascular invasion, lymph node metastasis, and an involved resection margin as independent prognostic factors. When serosal invasion was excluded from tumor staging, the 5-year survival rates became more clearly stratified: 100% in those with stage I disease, 62% in those with stage II, 25% in those with stage III, and 7% for patients with stage IV. CONCLUSIONS: Serosal invasion showed no survival impact after hepatic resection for mass-forming intrahepatic cholangiocarcinoma. When serosal invasion was omitted from the TNM staging proposed by the Liver Cancer Study Group of Japan, stratification of postoperative survival between stages was more effective.

Adult↗