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Biomedical subjects

T Tomiyama

Publications and source records attributed to T Tomiyama.

At least 55 records · Page 3Linked to original sources
PubMed1999

How many biopsies should be performed during percutaneous transhepatic cholangioscopy to diagnose biliary tract cancer?

BACKGROUND: The sensitivity of biopsy in the diagnosis of cholangiocarcinoma using percutaneous transhepatic cholangioscopy is not well defined. METHODS: Patients with a biliary tract malignancy (n = 52) underwent directed biopsy during percutaneous transhepatic cholangioscopy using a 1.8 mm diameter forceps. Histologic findings were correlated with endoscopic appearance. RESULTS: A diagnosis of carcinoma was made in all four patients with a tumor of the major duodenal papilla and in all 15 patients with a polypoid bile duct tumor with two biopsies from the mass. In 19 patients with stenotic bile duct cancer, a positive diagnosis was made in 95% of cases when three biopsies were taken from the margin of the stenotic area. When cholangioscopy showed a tortuous, dilated vessel (n = 10), the diagnosis of cancer was made with two biopsies taken from the margin of the stenosis. In 14 patients with metastatic bile duct cancer, the diagnosis was made in only 43% of cases when three biopsies were taken from the margin of the stenosis. When combined with results from the three biopsies taken from within the area of stenosis, the sensitivity for diagnosing pancreatic cancer improved from 20% to 60%. CONCLUSIONS: Directed cholangioscopic biopsies are highly sensitive for the diagnosis of cholangiocarcinoma but less sensitive for cancer metastatic to the bile duct. The numbers and locations of the biopsies required to make a diagnosis of carcinoma depend on the origin and cholangioscopic appearance of the tumor.

Adult↗
PubMed1999

Limitation of cholangiography in assessing longitudinal spread of extrahepatic bile duct carcinoma to the hepatic side.

BACKGROUND: Preoperative assessment of longitudinal spread of bile duct carcinoma (BDC) to the hepatic side remains a difficult problem for diagnostic imaging. METHODS: We studied the accuracy of cholangiography in assessing BDC. In 54 patients with extrahepatic bile duct cancer, cholangiographic findings were compared retrospectively with the histological findings of the resected specimens. RESULTS: Histological examination of specimens indicated longitudinal spread of the tumour to the hepatic side in 22 of 54 patients. The accuracy of cholangiography in assessing the extent of the longitudinal spread was only 34/54 (63%). When the cholangiographic images showed a main tumour with a collapsed edge, there was a significantly higher frequency of longitudinal spread compared with tumours with sharp edges (P< 0.05). In contrast, the accuracy of mapping biopsy under percutaneous transhepatic cholangioscopy (n=24) was 83%. CONCLUSIONS: Cholangiography cannot accurately assess the extent of the longitudinal spread of bile duct cancer. When cholangiographic images show a tumour with a collapsed edge, preoperative or intraoperative histological examination is essential to determine a suitable surgical line.

Adenocarcinoma↗
PubMed1999

Influence of bile duct diameter on the therapeutic quality of endoscopic balloon sphincteroplasty.

BACKGROUND AND STUDY AIMS: Endoscopic balloon sphincteroplasty (EBS) has been reported to be a safe alternative to sphincterotomy for the treatment of bile duct stones. We evaluated the factors which influence the therapeutic efficacy of EBS. PATIENTS AND METHODS: A total of 118 consecutive patients with bile duct stones were treated by EBS. After conventional endoscopic retrograde cholangiography (ERC), EBS was done using a biliary dilation catheter (balloon diameter, 8mm). The duct was then cleared using Dormia baskets or retrievel balloon catheters. When the stones were greater than 8 mm in diameter, mechanical lithotripsy was performed before extraction. Complete stone clearance was assessed by balloon-ERC and intraductal ultrasonography. Therapeutic efficacy was assessed using univariate and multivariate analysis. Patients were classified into three groups according to the bile duct diameter: nondilated (bile duct < or = 10 mm), mildly dilated (10 mm < bile duct < or = 15 mm), and severely dilated group (bile duct > 15 mm). RESULTS: In 113 of 118 (96%) patients, the stones were completely cleared with one to six endoscopic sessions (mean 1.6 sessions). In the nondilated group, 24 of 28 (85%) patients were cleared of stones in one session (mean 1.2 sessions), without the use of mechanical lithotripsy in 23 of 28 (82 %) patients. In the mildly dilated group, 23 of 38 (61 %) patients were cleared of stones in one session (mean 1.5 sessions). In contrast, in the severely dilated group, only 16 of 52 (31 %) patients were cleared of stones in one session (mean 2.0 sessions). Stone size, number of stones, and use of mechanical lithotripsy were independent variables which influenced the success of stone clearance in one session after EBS. CONCLUSION: When EBS is done in patients with bile duct stones, bile duct diameter may be a good indicator of therapeutic efficacy. In patients with severely dilated bile ducts (> 15 mm), EBS is of limited effectiveness.

Aged↗
PubMed1999

Simple and rapid identification of the Mycobacterium tuberculosis complex by immunochromatographic assay using anti-MPB64 monoclonal antibodies.

A newly developed immunochromatographic assay (MPB64-ICA) for identification of the Mycobacterium tuberculosis complex was evaluated with 20 reference strains of mycobacterial species and 111 clinical isolates. MPB64-ICA displayed a very strong reaction band with organisms belonging to the M. tuberculosis complex but not with mycobacteria other than M. tuberculosis (MOTT bacilli), except for one of four M. marinum strains tested and one M. flavescens strain, both of which gave very weak signals. The effectiveness of MPB64-ICA in combination with two liquid culture systems (MB-REDOX and MGIT) was tested. A total of 108 of 362 sputum specimens processed were positive for acid-fast bacilli. Samples taken from the cultures on the same days when either of the two culture systems became positive for mycobacteria were assayed with MPB64-ICA. Of 108 cultures with mycobacteria, 51 showed a positive signal with the test, in which the presence of the M. tuberculosis complex was demonstrated later by the Accuprobe for M. tuberculosis complex. In addition, MPB64-ICA could correctly detect the M. tuberculosis complex in mixed cultures of the M. tuberculosis complex and MOTT bacilli. These results indicate that MPB64-ICA can be easily used for rapid identification of the M. tuberculosis complex in combination with culture systems based on liquid media without any technical complexity in clinical laboratories.

Antibodies, Bacterial↗
PubMed1999

Endometrial development was improved by transdermal estradiol in patients treated with clomiphene citrate.

The objective of this study was to examine the effect of transdermal estrogen therapy on the endometrial thickness and serum hormone levels in anovulatory patients treated with clomiphene citrate (CC). There was a significant difference in endometrial thickness between the CC + transdermal estrogen group and the CC only group from day -2 to day +2. Serum estradiol (E2) levels in the CC + transdermal estrogen group were significantly higher than those in the CC only group on day -2 and day 0. Our results support that addition of transdermal E2 to the treatment protocol of the women treated with CC elicited a favorable response of the endometrium.

Administration, Cutaneous↗
PubMed1998

Characterization of biliary strictures using intraductal ultrasonography: comparison with percutaneous cholangioscopic biopsy.

BACKGROUND: We determined the accuracy of intraductal ultrasonography (IDUS) in distinguishing between bile duct cancer and benign bile duct disease. METHODS: Patients (n=42) who required bile duct biopsy using percutaneous transhepatic cholangioscopy (PTCS) to evaluate bile duct strictures or filling defects were studied. A thin-caliber ultrasonic probe (2.0 mm diameter and 20 MHz frequency) was inserted into the bile duct, and its images were prospectively reviewed before PTCS. RESULTS: Disruption of the bile duct wall structure, seen on IDUS, was associated with malignancy in 25 of 26 patients. When IDUS demonstrated a lesion with normal bile duct structure, six of nine patients were found to have no malignancy. IDUS demonstrated no intraductal lesion in seven patients, and bile duct biopsy also did not indicate cancer in any of these patients. The accuracy, sensitivity, and specificity of IDUS for diagnosing bile duct cancer were 76%, 89%, and 50%, respectively. When used in tandem with IDUS, the sensitivity of bile cytology (64%) and PTCS (93%) improved to 96% and 100%, respectively. CONCLUSIONS: The accuracy of IDUS for diagnosing bile duct cancer was less than that of PTCS (95%). However, the sensitivity for bile cytology, or bile duct biopsy improved when performed in combination with IDUS.

Adult↗
PubMed1998

Influence of biliary drainage catheter on bile duct wall thickness as measured by intraductal ultrasonography.

OBJECTIVE: To determine the influence of biliary drainage catheter placement on bile duct wall thickness, we performed intraductal ultrasonography (IDUS) in patients before and after biliary drainage. METHODS: Patients underwent IDUS before and after either short-term (n = 9, 6 to 8 days) or long-term (n = 9, 14 to 35 days) biliary drainage using a thin (2.0 mm diameter), 20 MHz probe inserted by means of a transpapillary route or a percutaneous tract. The bile duct wall thickness (mean +/- standard deviation) was retrospectively measured at the upper portion of the common hepatic duct. RESULTS: The bile duct wall thickness increased from 0.8+/-0.4 mm (predrainage) to 2.0+/-1.6 mm (post-drainage) in the long-term group (p < 0.001) but was not significantly increased in the short-term group. CONCLUSIONS: The bile duct wall thickness as measured on IDUS appears to be increased after placement of biliary drainage catheters.

Aged↗
PubMed1998

A pilot study on modified endoscopic variceal ligation using endoscopic ultrasonography with color Doppler function.

OBJECTIVE: The purpose of the study was to evaluate feasibility of modified endoscopic variceal ligation (EVL), namely the "intensive ligation" method, using endoscopic ultrasonography with color Doppler function (EUS-CD). METHODS: Forty-five patients with esophageal varices were treated by modified EVL. Variceal hemodynamics in 38 patients were examined using EUS-CD, which showed abdominal hemodynamics in detail under physiological conditions before and after the modified procedure. RESULTS: 1) The median number of treatment sessions was 3.2, and 41 O-rings on average were required per individual patient. 2) The median nonrecurrence period after treatment was 18 months (Kaplan-Meier method). 3) Nine patients with a good response to modified EVL did not have recurrences for 16.9+/-2.8 months, and five with a poor response had recurrences at 5.8+/-2.2 months. Gastric varices were related to the response to modified EVL (p < 0.05, Mann-Whitney's U test). 4) Minor complications in modified EVL as well as standard EVL were experienced; however, we had a patient with the development of meningitis, which was a major septic complication. 5) Before modified EVL, EUS-CD demonstrated that good responders had undeveloped (grade I) gastric varices in five of nine (56%); however, poor responders had developed (grade III) gastric varices in four of five (80%) (p < 0.05, Mann-Whitney's U test]. 6) After modified EVL, EUS-CD revealed that six of nine (67%) good responders and one of five (20%) poor responders showed a decrease in color signals in supplying veins; however, none of the former (0%) and three of the latter (60%) showed an increase (p < 0.05, Mann-Whitney's U test]. CONCLUSION: Modified EVL was safe and effective, at least with regard to intermediate-term outcome, especially when treating patients with undeveloped gastric varices revealed by EUS-CD. Both good and poor responders showed no exacerbation of gastric varices after the modified procedure, ultrasonographically as well as endoscopically.

Adult↗
PubMed1998

[Mercury sensitization induced by environmental exposure].

We investigated mercury sensitization in relation to urinary and hair mercury concentrations. Patch tests were performed on 215 medical students and these tests demonstrated that 28 students were mercury-sensitized (13.0%). Life-styles were studied by questionnaire in 26 of the mercury sensitized students and 46 of the non-sensitized subjects. Urinary mercury concentrations were measured in 25 sensitized and 46 non-sensitized and hair mercury concentrations were measured in 19 sensitized and 22 non-sensitized subjects. The eating of fish was not significantly associated with mercury sensitization (one-tailed t-test). The number of teeth treated with metals in the sensitized group was significantly higher than in the control group (6.8 +/- 4.3 in sensitized vs. 4.8 +/- 4.1 in non-sensitized, one-tailed t-test. p < 0.05). The usage of mercurochrome was not significantly associated with mercury sensitization (chi-squared test). Urinary mercury concentrations were not significantly higher in sensitized subjects. Hair mercury concentrations were significantly higher in sensitized subjects (1.98 +/- 0.91 micrograms/g in sensitized vs. 1.23 +/- 0.53 in non-sensitized, one-tailed t-test p < 0.05). These results suggest that mercury sensitization is associated with increased hair mercury concentrations but not with urinary mercury concentrations. In this study it is confirmed that dental amalgam for treating teeth may be an important factor relating to mercury sensitization.

Adult↗
PubMed1998

[Differential diagnosis of pancreatic tumor by contrast enhanced color Doppler ultrasonography].

For evaluating abdominal hemodynamic changes and diagnosing mass lesion, recently color Doppler ultrasonography (CDUS) have been applied. However, there are limitations in visualizing Doppler signals in small vessels with low flow velocity. To overcome these shortcomings, several contrast agents that facilitate evaluation of abdominal hemodynamics have been developed. We underwent Contrast enhanced color Doppler ultrasonography (CECD) with a galactose-based contrast agent in three patients with pancreatic tumor. In the patient with tumor forming pancreatitis, only CECD visualized the color signal in and around the tumor. In the patient with duct cell cancer, CDUS and CECD visualized only the color signal of the splenic artery penetrating the tumor, whereas in the patient with islet cell tumor, CECD visualized numerous color signals in the tumor. CECD appears to be useful in diagnosing pancreatic tumor.

Adult↗
PubMed1997

Rifampicin inhibits the toxicity of pre-aggregated amyloid peptides by binding to peptide fibrils and preventing amyloid-cell interaction.

Rifampicin and its analogues, p-benzoquinone and hydroquinone, inhibited the toxicity of preformed aggregates of human islet amyloid polypeptide, amylin, to rat pheochromocytoma PC12 cells, when preincubated with the aggregated peptide before addition to cell cultures. Immunofluorescence microscopy showed that they prevented the adhesion of amylin aggregates to the cell surface, and this effect was induced probably by their binding to peptide fibrils during preincubation. Other quinone derivatives, i.e., p-methoxyphenol, AA-861 and idebenone, failed to inhibit the toxicity and cell-surface adhesion of amylin aggregates. Rifampicin analogues also inhibited the toxicity of pre-aggregated amyloid beta1-42 peptides, suggesting a common toxic mechanism of different amyloid peptides and their therapeutic potential for several amyloidoses.

Amyloid↗
PubMed1997

Color Doppler ultrasonography in the diagnosis of cavernous transformation of the portal vein.

OBJECTIVE: To improve diagnostic accuracy, we studied the use of color Doppler ultrasound (CDUS) in patients with cavernous transformation of the portal vein (CTPV). SUBJECTS AND METHODS: In 18 patients, the usefulness of CDUS was compared with that of B-mode US for visualizing and diagnosing CTPV. Sensitivity for detecting CTPV on B-mode US, CT, and CDUS was also compared in 14 patients who underwent angiography which showed typical findings of CTPV. In addition, we classified each patient based on the morphologic appearance in the ultrasound examination and correlated those findings with the etiology. RESULTS: CDUS proved to be superior to B-mode US in identifying collateral channels and was highly sensitive for detecting CTPV in 17 (94%) of the 18 patients. In comparison with angiography performed in 14 patients, B-mode US detected CTPV in 9 (64%) patients, contrast-enhanced CT in 7 (50%), and CDUS in 13 (93%), indicating that CDUS was the most reliable diagnostic tool. It was also possible to assess the etiology of CTPV using a combination of color Doppler findings. Detection of arterial flow patterns within the portal vein thrombus correlated with malignant findings on histologic examination, whereas benign thrombi showed no flow signals. CONCLUSION: CDUS proved to be a reliable and useful modality for diagnosing CTPV and evaluating the etiology of this entity.

Adult↗
PubMed1997

Possibility of differentiating small hyperechoic liver tumours using contrast-enhanced colour Doppler ultrasonography: a preliminary study.

We performed a preliminary study to investigate the possibility of differentiating small hyperechoic liver tumours, including hepatocellular carcinomas (HCCs), haemangiomas and focal fatty lesions, by administering a galactose-based contrast agent (SH/TA-508 (Levovist)) during colour Doppler ultrasonography (US). Ten patients (age range: 48-81 years) with small liver tumours (four HCCs, four hemangiomas and two focal fatty lesions) of less than 20 mm in diameter presented with hyperechoic masses with no intratumoural colour signals on conventional colour Doppler US. All patients subsequently underwent colour Doppler US with this contrast agent. Colour Doppler images of the tumours were assessed before and after the intravenous injection of 8 ml of the contrast agent at a concentration of 400 mg/ml. Prior to injection of the contrast agent, no intratumoural colour signals were observed in any cases. After injection, intratumoural colour signals appeared in all HCCs and in two haemangiomas with tumour-margin enhancement. The enhanced colour signals appeared to be related to cardiac contraction in the HCCs, but not in the haemangiomas. In the remaining two haemangiomas, only tumour-margin enhancement was observed. In the focal fatty lesions, neither intratumoural nor tumour-margin enhancement was observed. These results, although preliminary, suggest that the detection of colour Doppler signals is improved by using a contrast agent and the differences between enhanced colour signals from HCCs and haemangiomas may help differentiate hyperechoic HCCs from other hyperechoic tumours, including haemangiomas and focal fatty lesions.

Aged↗
PubMed1997

High prevalence of hantavirus infection in a group of Chinese patients with acute hepatitis of unknown aetiology.

In southwestern China, small but substantial numbers of patients with acute hepatitis were found without known hepatropic viral infections (hepatitis A, B, C, D or E, cytomegalovirus, Epstein-Barr virus) and were receiving no hepatotoxic drugs. Prevalence of antibodies, both neutralizing and specific immunoglobulin (Ig)M and IgG, to Hantaan virus were evaluated in a cohort of 136 such patients: 83 were of unknown aetiology, 53 had known viral hepatitis and 59 healthy subjects acted as controls. The results showed that the incidence of neutralizing antibody to Hantaan virus in acute hepatitis patients with non-hepatitis A-E virus infections (13 of 83) was significantly higher than in those with A-E infections (0 of 53, P<0.01). Furthermore, the incidence of specific IgM antibody to Hantaan virus in acute hepatitis patients with non-hepatitis A-E virus infections (6 of 83) was significantly higher than in those with A-E infections (0 of 53, P<0.05) and in healthy subjects (0 of 59, P < 0.05). These findings suggest that Hantaan virus may be an important agent, contributing, at least in southwestern China, to a significant number of the cases of acute hepatitis of unknown aetiology. This hantavirus infection resulted in an acute hepatitis, differing from the typical diseases: haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS).

Acute Disease↗