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Biomedical subjects

T Yao

Publications and source records attributed to T Yao.

At least 109 records · Page 6Linked to original sources
PubMed1999

Clinical evaluation of 3D-CT cholangiography for preoperative examination in laparoscopic cholecystectomy.

Three-dimensional-computed tomography (3D-CT) cholangiography is a 3D shaded surface display image of the biliary tract obtained by using helical CT after intravenous cholangiography or cholangiography per percutaneous transhepatic cholangio-drainage tube. We investigated whether 3D-CT cholangiography could provide a useful image, for preoperative examination in laparoscopic cholecystectomy. Sixty-five patients with biliary diseases were examined by 3D-CT cholangiography. Helical scanning was performed on a Proceed Accell (GE Medical Systems, Waukesha, WI, USA). Three-dimensional images were created using an independent workstation. A clear image of the common bile duct was obtained for all patients (100%) by 3D-CT cholangiography. The gallbladder was well visualized in 54 (93%) and the cystic duct was shown to be opacified in 55 (95%) of the 58 patients with a gallbladder. Thirty-one patients were diagnosed as having gallstones by 3D-CT cholangiography (sensitivity. 72.1%; specificity, 100%; accuracy, 79.3%), while 43 were diagnosed as having cholecystolithiasis by ultrasonography. The advantages of 3D-CT cholangiography were a low level of invasiveness, easily obtained images compared to those obtained with endoscopic retrograde cholangiography (ERC), good opacification, and provision of a three-dimensional understanding of the biliary system, especially of the cystic duct. When combined with ultrasonography and routine liver function tests, 3D-CT cholangiography was considered very useful for obtaining information before laparoscopic cholecystectomy. It allowed the omission of ERC in many patients who were considered to have no common bile duct stone, by employment of 3D-CT cholangiography.

Adult↗
PubMed1999

HLA class II alleles in Japanese patients with inflammatory bowel disease.

The association of various HLA class II loci with Crohn's disease (CD) and ulcerative colitis (UC) has yet to be fully elucidated. To determine whether there is an association of HLA class II genes (DR, DQ and DP alleles) with inflammatory bowel disease (IBD), HLA class II genes for polymorphisms were analyzed at the DNA level in 111 patients with CD, 81 with UC and 525 healthy controls by the polymerase chain reaction-sequence specific oligonucleotide probe method. Allele and haplotype frequencies were compared between these populations. Results were as follows: 1) the presence of DQB1*0402 (RR=3.90, Pc=0.0001) was positively associated with CD; 2) the presence of DRB1*1502 (RR=4.51, P<1X10(-8)), DRB5*0102 (RR=4.70, Pc<1x10(-8)), DQA1*0103 (RR=3.72, Pc=1x10(-5)), DQB1*06011 (RR=3.78, PC=1x10(-5)), DPA1*0201 (RR=3.23, Pc=0.0001) and DPB1*0901 (RR=4.83, PC<1x10(8)) was positively associated and that of DRB4*0101 (RR=0.20, Pc<1X10(-8)) and DQA1*0302 (RR=0.34, Pc=0.001) negatively associated with UC; 3) haplotype analysis showed a positive association between the presence of DRB1*0410-DQA1*0302-DQB1*0402 and DRB1*0802-DQA1*0401-DQB1*0402 with CD, and a negative association between the presence of DRB1*1502-DQA1*0103-DQB1*06011 and CD, there was no association of DRB1*08032-DQA1*0103-DQB1*06011 with CD; and 4) in UC, a positive association with the presence of DRB1*1502-DQA1*0103-DQB1*06011 was found, but DRB1*08032-DQA1*0103-DQB1*06011 was not associated with it. In conclusion, in CD in the Japanese population, HLA-linked disease susceptibility alleles appear to be DQB1*0402 and DRB1*1502, a disease resistance allele. In UC, DRB1*1502 appears to be a disease susceptibility allele.

Adolescent↗
PubMed1999

Villous tumor of the colon and rectum with special reference to roles of p53 and bcl-2 in adenoma-carcinoma sequence.

Villous tumors are rare and their histological diagnosis from biopsy specimens is often difficult. To ascertain its tumor progression, including the genetic events, would be useful for clinical treatment. Clinicopathological features and the expression of p53 and bcl-2 proteins were investigated in 50 villous tumors from 49 patients. The patients' ages ranged widely from 32 to 84 years (average, 61 years). Females were more frequently affected than males (male:female ratio, 20:29). Thirty-six (72%) of the villous tumors were present within the sigmoid colon and rectum. Histologically, 17 (34%) of these contained carcinomas in villous adenomas (CIVA), while 24 (73%) of 33 villous adenomas (VA) contained high-grade dysplasia. Most of the CIVA revealed well-differentiated adenocarcinoma, often with focal or diffuse mucin pools. Three lesions of invasive carcinomas were composed of extremely well-differentiated components. The average size of the CIVA (79 mm) was significantly larger than that of the VA (51 mm). Overexpression of p53 protein was recognized in 12% of VA, in 24% of mucosal components of CIVA and in 18% of invasive components of CIVA. Overexpression of bcl-2 was recognized in 57% of VA, 33% of mucosal components of CIVA, and 7% of invasive components of CIVA. Several characteristic features were recognized in villous tumors, which comprised: (i) a high frequency of coexistence of carcinoma; (ii) multiple foci of carcinomas arising in adenomatous tumors; (iii) a lower histological grade of carcinomas, often with mucin pools; (iv) the existence of extremely well-differentiated adenocarcinomas; and (v) less frequent expression of p53 protein in the carcinomatous components. According to these findings, the pathway of tumor progression in the villous tumors is possibly different from that of sporadic colorectal carcinomas. Because of the peculiarity of villous tumors, careful clinical management is required.

Adenocarcinoma↗
PubMed1999

The role of total parenteral nutrition in the management of patients with acute attacks of inflammatory bowel disease.

The aim of this study was to evaluate the effects of the prolonged duration of total parenteral nutrition (TPN) on the clinical, laboratory, and nutritional parameters and short-term outcome in acute attacks of ulcerative colitis and Crohn's colitis, and the difference in the response to TPN between the two diseases. Twenty-two patients with severely and moderately active ulcerative colitis (8 severe and 14 moderate) and 12 patients with Crohn's colitis were analyzed retrospectively. Eleven of 22 patients with ulcerative colitis were treated with TPN and corticosteroids (TPN group). The remaining 11 patients were treated with corticosteroids alone and hospital meals (oral diet group). Both groups were matched regarding disease severity at pretreatment. The clinical characteristics, and the initial and total dosages of corticosteroids for 3 weeks were similar between the two groups. The authors compared the changes in the clinical, inflammatory, and nutritional parameters and short-term outcome between the TPN and the oral diet groups with ulcerative colitis. The same evaluations were also made for 12 patients with Crohn's colitis who received TPN (CD group). The TPN group did not show any significant improvement in the clinical parameter, inflammatory signs, or nutritional state compared with the oral diet group with ulcerative colitis. The remission rate after 3 weeks of therapy and a colectomy rate also showed no significant difference between the two groups. In contrast, TPN resulted in a disappearance of clinical symptoms and an improvement in both the inflammatory and nutritional parameters in the CD group. Only one of the 12 patients with Crohn's colitis underwent colectomy. TPN induced no additional benefit in corticosteroid therapy in an acute attack of ulcerative colitis. In contrast, TPN may have primary effects on Crohn's colitis.

Adrenal Cortex Hormones↗
PubMed1999

Rapidly growing primary gastric B-cell lymphoma after eradication of Helicobacter pylori.

Helicobacter pylori (H. pylori) infection plays a decisive role in primary gastric B-cell lymphoma especially of mucosa-associated lymphoid tissue (MALT)-type. We treated a 47-year-old male patient with primary gastric B-cell lymphoma associated with H. pylori infection. Although antibiotic therapy for eradication of H. pylori caused great improvement in the low-grade MALT lymphoma-like lesion, the small areas of high-grade lesion rapidly formed a new bulky mass in only 8 weeks. This suggests that eradication of H. pylori is not effective for high-grade lymphoma.

Anti-Bacterial Agents↗
PubMed1999

[Comparison of the therapeutic effects and acid suppression of H2-receptor antagonist and proton pump inhibitor in patients with gastric body ulcer--a prospective controlled trial].

We studied, the rate and the affecting factor of ulcer healing of patients with gastric body ulcer treated by H2-receptor antagonist (H2-RA) and proton pump inhibitor (PPI). Gastric acidity was also examined using 24 hr pH monitoring. No difference was observed between the affecting factor of ulcer healing and healing rate (94.7% and 94.9%) among the patients treated by H2-RA or PPI. The average time below pH3 during treatment with H2-RA or PPI were 17.4 +/- 4.3 hr and 23.0 +/- 1.5 hr, respectively. Acid suppression was superior in PPI treated group than in H2-RA group. From these findings, we concluded that H2-RA had sufficient therapeutic efficacy in treating gastric body ulcer.

Anti-Ulcer Agents↗
PubMed1999

[Malignant lymphoma with c-myc gene rearrangement in a patient receiving long-term treatment for multiple myeloma].

We encountered a 65-year-old woman with diffuse large B-cell lymphoma showing t(8;14)(q24;q32) and c-myc gene rearrangement that developed following 12 years of melphalan-based chemotherapy for multiple myeloma. Short-term remission was obtained by CHOP chemotherapy. However, shortly thereafter the patient died of an aggressive progression of lymphoma. It was suspected that the lymphoma was a secondary malignancy related to the treatment with cytotoxic agents and radiation for prolonged multiple myeloma. The chromosomal abnormality t(8;14)(q24;q32) is rare in secondary malignancies. Overexpression of c-myc by gene rearrangement may be associated with clinical courses manifested by the rapid progression of lymphoma.

Aged↗
PubMed1999

Effects of ramipril on cardiac gene transcription levels of angiotensin II receptors after myocardial infarction.

AIM: To study the early changes of cardiac angiotensin (Ang) II receptor gene transcription after myocardial infarction (MI) in rats chronically treated with the angiotensin-converting enzyme (ACE) inhibitor ramipril. METHODS: MI was induced by left anterior descending coronary artery ligation in rats and sham-operated rats were used as control. Rats were treated daily with ramipril (1 mg.kg-1) or water, initiated 1 wk before surgery. Quantitative RT-PCR was applied to determine the Ang II receptors AT1, AT2 receptor gene mRNA levels in the non-infarcted myocardium. RESULTS: AT1 and AT2 mRNA levels increased time point-dependently in the cardiac septum after MI reaching a peak on d 1. There was no significant difference of the myocardial AT1 and AT2 receptor mRNA levels between the ramipril-treated and water-treated rats after MI. CONCLUSION: The AT1 and AT2 receptor gene transcription in the non-infarcted myocardium was associated with the process of cardiac remodeling after MI but not affected by ACE inhibition.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

[Changes in blood pressure in normal rats transplanted with kidney of SHR].

The experiments were performed on spontaneously hypertensive rats (SHR) and Wistar Kyoto (WKY) rats of 12 weeks old. Systolic blood pressure in WKY recipients receiving an SHR or WKY rat kidney was observed and the influence of immuoinhibitor cyclosporin (CsA) on blood pressure was investigated. The systolic blood pressure (SBP) of tail artery was measured by tail cuff technique in 6 WKY recipients of one SHR kidney and 6 WKY recipients of a WKY kidney from before transplantation to 5 weeks after transplantation. At the time when kidneys were harvested for transplantation from 12-week-old SHR and WKY rats, the SBP in WKY recipients was not significantly different. The SBP in WKY recipients of an SHR kidney was significantly higher than that in WKY recipients of a WKY kidney at 3, 4 and 5 weeks after transplantation. The immunoinhibitor CsA exerted no effect on the arterial blood pressure in either intact or uninephrectomized SHR and WKY rats. The results indicate that the kidney of SHR plays an important role in the pathogenesis of genetic hypertension.

Animals↗
PubMed1999

[Changes in vasopressin V1 receptor mRNA level in rats with high blood pressure induced by chronic stress].

Using reverse transcription polymerase chain reaction (RT-PCR) combined with Southern blotting hybridization technique, the AVP V1 receptor mRNA was found to be widely distributed in central neuronal system and other tissues of rats, such as cerebral cortex, hypothalamus, medulla, liver and kidney. The receptor mRNA levels in the cortex, hypothalamus and medulla were decreased significantly in chronically stressed rats, as compared with normal controls (cortex: P < 0.05; hypothalamus: P < 0.01; medulla: P < 0.001). But no significant change was observed in tissues of heart, liver and kidney (heart: P > 0.05; liver: P > 0.05; kidney: P > 0.05). These results suggest that chronic stress may lead to a decrease of AVP V1 receptor density in the CNS as a result of decreased synthesis.

Animals↗
PubMed1999

[Purification of outer membrane proteins in Pseudomonas aeruginosa by high performance ion-exchange liquid chromatography].

Pseudomonas aeruginosa PAO1 was used in this study. Isolation of outer membrane was accomplished by treating the cell envelope with EDTA and lysozyme, followed by centrifugation. The outer membrane (10 mg of protein) was mixed with 34 mmol/L octyl beta-glucoside-5 mmol/L EDTA-10 mmol/L Tris-HCl (pH 8.0) and subjected to supersonic oscillation for 2 min. The centrifuged supernatant (100 kgf for 30 min at 20 degrees C) was applied onto a DEAE ion-exchange high performance liquid chromatographic column (TSK gel-DEAE-5PW column, 0.75 cm x 7.5 cm i.d.) that was equilibrated with a solution of 10 mmol/L Tris-HCl buffer (pH 8.0) containing 2.5 mmol/L beta-C12E8 and 1 mmol/L EDTA. The column was washed with the same solution and eluted with a linear gradient of 0-0.5 mol/L NaCl in the same solution and fractions A, B, C were collected. Proteins in these fractions were analyzed by SDS-polyacrylamide gel electrophoresis and quantified by the method of Lowry et al. Protein E(Mr 43,000), G(Mr 25,000) and H (Mr 19,000) flowed through the column without adsorption in fraction A. Protein C(Mr 70,000), D(Mr 46,000) and a small amount of F (Mr 34,000) were eluted in fraction B. Fraction A was concentrated with ultrafiltration and applied again onto a DEAE ion-exchange HPLC column equilibrated with 10 mmol/L Tris-HCl buffer, pH 8.0, containing 34 mmol/L beta-C12E8 and 1 mmol/L MgCl2. Fraction B was subjected to DEAE ion-exchange HPLC column in the presence of EDTA. This fraction was then applied onto a DEAE ion-exchange HPLC column equilibrated with 10 mmol/L Tris-HCl buffer, pH 8.0, containing 34 mmol/L octylglucoside and 1 mmol/L EDTA. By these procedures protein C, D and E were purified to apparent homogeneity as judged by SDS-PAGE. In this work, we purified the outer membrane proteins of Pseudomonas aeruginosa, and used a new technique selectively solubilizing the cytoplasmic membrane with sodium lauryl sarcosinate for isolating the outer membrane proteins of Pseudomonas aeruginosa because of its relative simplicity.

Adhesins, Bacterial↗
PubMed1998

Differential effect of B lymphocyte-induced maturation protein (Blimp-1) expression on cell fate during B cell development.

The B lymphocyte-induced maturation protein (Blimp-1) upregulates the expression of syndecan-1 and J chain and represses that of c-myc. We have transfected Blimp-1 into two sublines of the BCL1 B cell lymphoma that represent distinct stages of B cell development in secondary lymphoid tissues. After interleukin (IL)-2 and IL-5 stimulation, the BCL1 3B3 cells differentiate into centrocyte-like cells, whereas the BCL1 5B1b cells blast and appear to be blocked at the centroblast stage. This blasting effect and the increase in IgM secretion that follows it can be blocked by a dominant negative form of Blimp-1. At the same time, the ectopic expression of Blimp-1 in these partially activated cells induces an apoptotic response that also can be suppressed by the same dominant negative protein. A similar effect was noticed when Blimp-1 was expressed in the mature L10A and the immature WEHI-231 lines, indicating this may be a general effect at earlier stages of the B cell development, and distinct from the ability of Blimp-1 to induce maturation in late stages of differentiation. Truncation mutants indicate that the induction of the apoptotic response relies mainly on 69 amino acids within Blimp-1's proline-rich domain. We propose that Blimp-1 expression defines a checkpoint beyond which fully activated B cells proceed to the plasma cell stage, whereas immature and partially activated cells are eliminated at this point.

Apoptosis↗
PubMed1998

Amperometric biosensor with a composite membrane of sol-gel derived enzyme film and electrochemically generated poly(1,2-diaminobenzene) film.

A sol-gel silicate-based biosensor for glucose was made by utilizing a composite membrane of sol-gel enzyme film and electrochemically generated poly(1,2-diaminobenzene) film to improve the selectivity of the sol-gel enzyme sensors. The stability of the sensor was improved by exposing the enzyme layer to glutaraldehyde vapor. The glucose sensor responded rapidly (ca. 15 s) to glucose at 0.6 V (versus Ag/AgCl), without any interferences from electroactive species such as L-ascorbate and urate below 0.2 mM. Reliable results were obtained in the assays of glucose in controlled human sera, with both the steady-state and flow-injection measurements. Subsequently, the same sol-gel procedure was applied to the preparation of the sensors for galactose and cholesterol. The galactose and cholesterol sensors responded rapidly to galactose and cholesterol, respectively, although the sensitivity of these sensors was inferior to that of glucose sensor.

Biocompatible Materials↗
PubMed1998

A father and son with Turcot's syndrome: evidence for autosomal dominant inheritance: report of two cases.

Typical Turcot's syndrome is characterized by the association of a brain glioma together with multiple colonic polyposis, in which the number of polypoid lesions is small and the association of colonic cancer occurs at a younger age than in familial adenomatous polyposis. We describe a family in which both the father and his son presented with typical Turcot's syndrome without parental consanguinity. This is the first report of a family that is considered to follow an autosomal dominant inheritance. After reviewing 25 documented cases in which the average age of death was 20.3 years old, it was learned that the major cause of death was brain tumor (76 percent) and the minor cause was colon cancer (16 percent). Patients were very young and, therefore, unlikely to have produced a child before their death. These facts seem to support the theory that Turcot's syndrome is an autosomal dominant disorder.

Adenomatous Polyposis Coli↗