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Biomedical subjects

J F Huang

Publications and source records attributed to J F Huang.

At least 19 recordsLinked to original sources
PubMed2005

Microwave tumour coagulation plus in situ treatment with cytokine-microparticles: induction of potent anti-residual tumour immunity.

After local microwave coagulation and subsequent intra-tumoural injection of microparticles encapsulating interleukin-2 and granulocyte-macrophage colony-stimulating factor, the anti-tumour efficacy against subcutaneous Lewis lung carcinoma in syngeneic mice was evaluated. This treatment elicited a potent systemic anti-tumour immunity that protected treated mice from re-challenge with the same tumour cells and caused the distal tumours in a bilateral tumour model to be rejected. Cytotoxicity assay indicated that both T- and natural killer cells acted as the effector cells in the anti-tumour immunity. These data highlight the feasibility of microwave-pre-treated in situ cancer vaccination for clinical use.

Animals↗
PubMed2005

Molecular characterization of a new begomovirus infecting Senecio scandens in China.

Three begomovirus isolates, G46, G83 and G84 from Senecio scandens showing yellow mosaic symptoms were collected from Guangxi Province, P.R. China. The isolates were detected by PCR using universal primers for begomoviruses. Comparison of partial DNA-A sequences (approximately 500 bp) of the isolates revealed their 98.7-99.1% identity. The isolate G46, chosen for complete DNA-A sequencing, consisted of 2746 nt and had a typical genomic organization of begomoviruses. The G46 DNA-A had the highest sequence identity (72.4%) with that of Ageratum leaf curl virus among begomoviruses. The molecular data suggest that the isolate G46 is a new begomovirus (species), for which the name Senecio yellow mosaic virus (Senecio yellow mosaic virus) is proposed.

Asteraceae↗
PubMed2001

Color Doppler velocity profile assessment of portal hemodynamics in cirrhotic patients with portal hypertension: correlation with esophageal variceal bleeding.

PURPOSE: Using the color Doppler velocity profile (CDVP), we investigated portal hemodynamics and their relationship with esophageal variceal bleeding (EVB) in patients with cirrhosis and portal hypertension. METHODS: The hemodynamics of the portal trunk, right anterior portal branch, and splenic vein were evaluated in 69 cirrhotic patients with portal hypertension and 46 healthy volunteers. The CDVP, a recently developed Doppler software, was used to measure blood flow velocity and flow volume; evaluate the spatial distribution of flow velocities in the cross-section of a vessel (velocity profile), as reflected by the profile parameter (n); and assess changes in flow volume over time (flow profile). The congestion index was calculated by dividing the cross-sectional area by the maximum cross-sectional velocity (CSVmax). The hemodynamic features were compared between patients without a history of EVB [EVB(-)] and those with a history of EVB [EVB(+)], and a logistic regression model was employed to identify factors associated with EVB. RESULTS: Compared with the healthy group, the cirrhotic group had a significantly lower mean CSVmax in the portal trunk and right anterior portal branch (both p < 0.01), a significantly elevated mean flow volume in the splenic vein and portal trunk (both p < 0.01), a significantly elevated mean ratio of splenic vein flow volume to portal trunk flow volume (SV/PT) (p < 0.001), and a significantly greater mean congestion index in the portal trunk, right anterior portal branch, and splenic vein (all p < 0.01). In the cirrhotic group, there was a significantly higher incidence of a flat flow pattern in the right anterior portal branch and a phasic flow pattern in the splenic vein than in the healthy group (both p < 0.01). Among cirrhotic patients, the EVB(+) group had a significantly greater mean flow volume in the splenic vein (p < 0.01), greater mean SV/PT (p < 0.01), greater mean spleen size (p < 0.05), and lower mean portal trunk n value (p < 0.05) compared with the EVB(-) group. Logistic regression analysis revealed that the SV/PT and portal trunk n value were independent EVB-related factors. CONCLUSIONS: The results suggest that portal hemodynamics in cirrhotic patients are characterized by passive congestion and increased blood flow. However, these 2 features had different preponderances in different parts of the portal venous system. Increased flow in the splenic vein may be the primary source of increased portal flow and may play a role in the development of EVB. The SV/PT and portal trunk n value may be valuable factors for predicting EVB.

Adolescent↗
PubMed2001

Hepatitis C virus infection among teenagers in an endemic township in Taiwan: epidemiological and clinical follow-up studies.

The aim of the study was to elucidate the epidemiological features of Hepatitis C virus (HCV) infection among teenagers in an endemic area by conducting a mass screening study. We also investigated the clinical outcome of the anti-HCV-positive subjects by conducting subsequent short-term and long-term follow-up studies. All 2837 students of two junior middle schools in Tzukuan, aged 13-16 years, were invited to be screened for anti-HCV, HBsAg, AST and ALT in October 1995. A total of 2726 (96%) students responded. Anti-HCV, HCV RNA and aminotransferase levels were evaluated among anti-HCV-positive students 1 month and 30 months later, respectively. A total of 38 (1.4%; M/F = 22/16) participants were anti-HCV-positive. The anti-HCV-positive students had higher rates of exposures to transfusion, anti-HCV-positive families and surgery. The prevalence (2.8%) of the 7 maritime villages was markedly higher than that (0.7%) of the other 8 villages (P < 0.001). Subsequent follow-up studies demonstrated that there might be 5 cases of acute or recent HCV infection, and 6 cases who had recovered from chronic HCV infection.

Adolescent↗
PubMed2001

The serological and molecular epidemiology of GB virus C/hepatitis G virus infection in a hepatitis C and B endemic area.

OBJECTIVES: To investigate the serological and molecular characteristics of GB virus C/hepatitis G virus (GBV-C/HGV) infection in the hepatitis C virus (HCV)/hepatitis B virus (HBV)-endemic areas in Taiwan. METHODS: Sera from 200 residents from Masago, an HCV/HBV-endemic community in Taiwan, and 400 blood donors were tested for GBV-C/HGV RNA by using nested reverse transcription-polymerase chain reaction and for antibodies to GBV-C/HGV E2-protein (anti-E2) by an enzyme-linked immunosorbent assay. Phylogenetic analysis of GBV-C/HGV was performed. RESULTS: The prevalence of GBV-C/HGV viraemia, anti-E2 and GBV-C/HGV exposure among residents of Masago was significantly higher than that among donors (17.0%, 25.5% and 39.5% vs. 3.3%, 7.5% and 10.3%, respectively; all P < 0.0001). In Masago, the prevalence of GBV-C/HGV exposure was significantly higher in residents exposed to HCV than in those without HCV exposure (45.8% vs. 24.1%;P< 0.005). Based on multivariate analyses, HCV viraemia was the only significant factor associated with elevated levels of alanine aminotransferase in Masago. Phylogenetic analysis showed all 34 GBV-C/HGV isolates from Masago clustered within genotype 3. CONCLUSIONS: GBV-C/HGV was highly prevalent in Masago, an HCV/HBV-endemic community in Taiwan. HCV viraemia played the most important clinical hepatopathic role in the area. Infections with other hepatitis viruses did not influence the anti-E2 seroconversion from GBV-C/HGV infections.

Adult↗
PubMed2001

Intraoperative liver ultrasound: the Chinese experience.

This article introduces the experience in intraoperative liver ultrasound in China. Intraoperative liver ultrasound was mainly used in patients treated for hepatocellular carcinoma (HCC) and hepatolithiasis, with purposes for further diagnosis and decision making and guidance of surgical procedures. With respect to detection of liver tumors, intraoperative ultrasound (IOUS) was significantly more sensitive, especially in small foci, as compared with preoperative ultrasound and computed tomography scanning, as well as intraoperative inspection and palpation. It was also more precise in localizing lesions than preoperative imaging investigations. Intraoperative echoangiography via hepatic arterial injection of carbon dioxide was shown not only to help assess position of catheter and vascularity of tumors but also to improve sensitivity in detecting small tumor foci in patients undergoing hepatic arterial chemoembolization. Intraoperative ultrasound was also used to guide hepatectomies. It ensured to obtain curative resection of the tumors and maximum preservation of functioning hepatic parenchyma simultaneously. For hepatolithiasis, IOUS offered accurate localization of stones, lithotomy (with its guidance), reduction of the rate of residual stones, and follow-up of the outcome of lithotomy.

Journal Article↗
PubMed2001

Hepatocellular carcinoma: US-guided percutaneous microwave coagulation therapy.

PURPOSE: To evaluate the use of percutaneous microwave coagulation therapy for hepatocellular carcinoma, particularly with tumor nodules larger than 2 cm in diameter. MATERIALS AND METHODS: Fifty patients with 107 hepatocellular carcinoma nodules (mean diameter, 2.7 cm +/- 1.5 [SD]; range, 0.8-6.4 cm) were treated with percutaneous microwave coagulation therapy. Single electrode insertion was used in 46 nodules (43.0%) 2 cm or smaller, whereas multiple electrode insertion was applied in 61 (57.0%) nodules larger than 2 cm. RESULTS: At 1 month after therapy, technical success for tumors 2 cm or smaller and those larger than 2 cm was achieved in 45 (98%) and 56 (92%) nodules, respectively. After follow-up of 9 months or longer, local recurrence was found in one nodule (2%) sized 1.8 cm and in five nodules (8%) larger than 2 cm. At the end of the study, 26 (52%) of 50 patients were free of disease, and disease-free survival rates at 1 and 2 years were 55% and 41%, respectively. Overall survival rates at 1, 2, and 3 years were 96%, 83%, and 73%, respectively. CONCLUSION: Percutaneous microwave coagulation therapy is an effective and safe therapeutic modality for hepatocellular carcinoma. A multiple electrode insertion technique can enhance the effectiveness of this therapy in tumors 6 cm or smaller.

Adult↗
PubMed2001

Changing prevalence of hepatitis C virus genotypes: molecular epidemiology and clinical implications in the hepatitis C virus hyperendemic areas and a tertiary referral center in Taiwan.

To determine the hepatitis C virus (HCV) genotype distribution in Taiwan and to clarify the relationship between genotype and the pathogenesis of HCV infection, 1,164 subjects positive for serum HCV antibodies and HCV RNA from three HCV hyperendemic areas (Masago, Tzukuan, and Taoyuan) and a tertiary referral center in Taiwan were studied during 1995-1997. HCV genotypes and viral loads were determined using Okamoto's method and branched DNA assay, respectively. Genotype 1b was the most prevalent in Tzukuan (61.9%), Taoyuan (76.9%), and the referral center (47.0%). By contrast, genotype 2a was the major HCV type in Masago (63.5%). Prevalence of genotype 1b positively and that of genotype 2a negatively correlated to age, regardless of study populations (P < 0.01). Based on multivariate analysis, the significant factors associated with the presence of cirrhosis, with or without hepatocellular carcinoma, in chronic hepatitis C patients were genotype 1b and age. In conclusion, these results underline that independent HCV outbreaks continue in HCV hyperendemic areas in Taiwan, concomitant with a changing relative prevalence of HCV genotypes in relation to age. Both the correlation of genotype 1b with age (cohort effect) and intrinsic properties of HCV genotypes are probably responsible for the association between genotype and the pathogenesis of HCV infection.

Adolescent↗
PubMed2000

[Influence of lead on activity of nitric oxide synthase in neurons and vessel smooth muscle of small intestine in rats].

The beta-NADPH histochemical method was used to study the effect of lead on activity of nitric oxide synthase(NOS) in neurons and vessel smooth muscles of intestinal wall in rats. The results showed that the number of NOS positive neurons and fibers was decreased and degenerative changes of some NOS positive neurons were found after the lead acetate intraperitoneal injection. The activity of NOS in the vessel smooth muscles was reduced. It suggests that lead colic may be induced by reduction of NO in the neurons which innervate the gut smooth muscles.

Animals↗
PubMed2000

Intramolecular activation of a Ca(2+)-dependent protein kinase is disrupted by insertions in the tether that connects the calmodulin-like domain to the kinase.

Ca(2+)-dependent protein kinases (CDPK) have a calmodulin-like domain (CaM-LD) tethered to the C-terminal end of the kinase. Activation is proposed to involve intramolecular binding of the CaM-LD to a junction sequence that connects the CaM-LD to the kinase domain. Consistent with this model, a truncated CDPK (DeltaNC) in which the CaM-LD has been deleted can be activated in a bimolecular interaction with an isolated CaM-LD or calmodulin, similar to the activation of a calmodulin-dependent protein kinase (CaMK) by calmodulin. Here we provide genetic evidence that this bimolecular activation requires a nine-residue binding segment from F436 to I444 (numbers correspond to CPK-1 accession number L14771). Two mutations at either end of this core segment (F436/A and VI444/AA) severely disrupted bimolecular activation, whereas flanking mutations had only minor effects. Intramolecular activation of a full-length kinase was also disrupted by a VI444/AA mutation, but surprisingly not by a F436/A mutation (at the N-terminal end of the binding site). Interestingly, intramolecular but not bimolecular activation was disrupted by insertion mutations placed immediately downstream of I444. To show that mutant enzymes were not misfolded, latent kinase activity was stimulated through binding of an antijunction antibody. Results here support a model of intramolecular activation in which the tether (A445 to G455) that connects the CaM-LD to the kinase provides an important structural constraint and is not just a simple flexible connection.

Amino Acid Sequence↗
PubMed2000

T cells can use either T cell receptor or CD28 receptors to absorb and internalize cell surface molecules derived from antigen-presenting cells.

At the site of contact between T cells and antigen-presenting cells (APCs), T cell receptor (TCR)-peptide-major histocompatibility complex (MHC) interaction is intensified by interactions between other molecules, notably by CD28 and lymphocyte function-associated antigen 1 (LFA-1) on T cells interacting with B7 (B7-1 and B7-2), and intracellular adhesion molecule 1 (ICAM-1), respectively, on APCs. Here, we show that during T cell-APC interaction, T cells rapidly absorb various molecules from APCs onto the cell membrane and then internalize these molecules. This process is dictated by at least two receptors on T cells, namely CD28 and TCR molecules. The biological significance of T cell uptake of molecules from APCs is unclear. One possibility is that this process may allow activated T cells to move freely from one APC to another and eventually gain entry into the circulation.

Animals↗
PubMed2000

The epidemiology of TT virus (TTV) infection in a hepatitis C and B virus hyperendemic area of southern Taiwan.

TT virus (TTV) is a newly isolated DNA virus from the serum of a patient with posttransfusion hepatitis of unknown etiology in 1997. To evaluate the clinical and molecular characteristics of TT virus (TTV) in a hepatitis C virus (HCV) and B (HBV) hyperendemic area (Masago), 200 residents were enrolled in the study. The sera were tested for alanine aminotransferase (ALT), HCV RNA and GB virus C/Hepatitis G virus (HGV) RNA, TTV DNA, HBsAg, anti-HCV and antibodies to HGV E2-protein (anti-E2). TTV DNA was positive in 99 of the 200 sera with a prevalence rate of 49.5%. The prevalence of HBsAg, anti-HCV, HCV RNA, HGV RNA, anti-E2 and HGV exposure (defined as positive for serum HGV RNA and/or anti-E2) was 38.9%, 69.5%, 64.5%, 17.0%, 25.5% and 39.5%, respectively. Neither clinical nor virological factors were associated with TTV viremia. The rate of ALT abnormality was significantly elevated in HCV RNA-positive (34.9%) than -negative (7.0%) residents (p < 0.001). HCV viremia was the only factor significantly associated with ALT elevation by multiple logistic regression (odds ratio: 6.96; 95% C.I.: 2.60-18.7). We concluded that in this HCV/HBV hyperendemic area, the prevalence of TTV DNA was high. No significant clinical factor was observed to be associated with TTV infection. TTV infection is not related to abnormal ALT levels and ALT abnormality was mainly attributable to HCV but not TTV, HBV or HGV infection.

Adult↗
PubMed2000

[Anatomical study and clinical applications of flaps based on cutaneous branches arising from posterior tibial vessels].

OBJECTIVE: To provide an anatomical basis for the clinical applications of the medial fascinocutaneous flap of calf and to verify its clinical value. METHODS: In 20 lower limb specimens of adult human cadavers, the number, course, size, position and distribution of septocutaneous branches of the posterior tibial vessels are marked by means of red latex and black ink irrigations through femur artery and septocutaneous branches of the posterior tibial artery respectively. RESULTS: The posterior tibial artery gives off several septocutaneous branches at the upper, middle and lower one-third of the leg respectively. Each septocutaneous artery has one or sometimes two concomitant veins. Based on this result, anterograde or reverse pedicled fasciocutaneous flap can be performed for the purpose of repairing soft tissue defects of leg and foot. The flap was clinically applied to treat leg and foot soft tissue defects in 12 cases with satisfactory results. CONCLUSION: The flap is easy to dissect, the posterior tibial artery can be preserved with high successful rate. Therefore, it offers an useful alternative in the repairing and reconstruction of nonextensive soft tissue defects in the leg and foot.

Adolescent↗
PubMed1999

TCR-Mediated internalization of peptide-MHC complexes acquired by T cells.

Peptide-major histocompatibility complex protein complexes (pMHCs) on antigen-presenting cells (APCs) are central to T cell activation. Within minutes of peptide-specific T cells interacting with APCs, pMHCs on APCs formed clusters at the site of T cell contact. Thereafter, these clusters were acquired by T cells and internalized through T cell receptor-mediated endocytosis. During this process, T cells became sensitive to peptide-specific lysis by neighboring T cells (fratricide). This form of immunoregulation could explain the "exhaustion" of T cell responses that is induced by high viral loads and may serve to down-regulate immune responses.

Animals↗