Yi-Ming Arthur Chen

The Therapeutic Potential of Human Umbilical Mesenchymal Stem Cells from Wharton's Jelly in the Treatment of Rat Liver Fibrosis

We investigated the effect of human umbilical mesenchymal stem cells (HUMSCs) from Whartons jelly on carbon tetrachloride (CCl4)–induced liver fibrosis in rats. Rats were treated with CCl4 for 4 weeks, and this was followed by a direct injection of HUMSCs into their livers. After 4 more weeks of CCl4 treatment (8 weeks in all), rats with HUMSC transplants [CCl4 (8W)+HUMSC liver] exhibited a significant reduction in liver fibrosis, as evidenced by Sirius red staining and a collagen content assay, in comparison with rats treated with CCl4 for 8 weeks without HUMSC transplants [CCl4 (8W)]. Moreover, rats in the CCl4 (8W)+HUMSC (liver) group had significantly lower levels of serum glutamic oxaloacetic transaminase, glutamic pyruvate transaminase, α‐smooth muscle actin, and transforming growth factor‐β1 in the liver, whereas the expression of hepatic mesenchymal epithelial transition factor–phosphorylated type (Met‐P) and hepatocyte growth factor was up‐regulated, in comparison with the CCl4 (8W) group. Notably, engrafted HUMSCs scattered mostly in the hepatic connective tissue but did not differentiate into hepatocytes expressing human albumin or α‐fetoprotein. Instead, these engrafted, undifferentiated HUMSCs secreted a variety of bioactive cytokines that may restore liver function and promote regeneration. Human cytokine assay revealed that the amounts of human cutaneous T cell–attracting chemokine, leukemia inhibitory factor, and prolactin were substantially greater in the livers of the CCl4 (8W)+HUMSC (liver) group, with considerably reduced hepatic inflammation manifested by a micro positron emission tomography scan. Our findings suggest that xenogeneic transplantation of HUMSCs is a novel approach for treating liver fibrosis and may be a promising therapeutic intervention in the future. Liver Transpl 15:484–495, 2009.

HIV-1 in Taiwan

Taiwan is entering a new and dangerous phase of its HIV-1/AIDS epidemic. By the end of 2006 13 702 individuals (including 599 foreigners) had been reported as infected with HIV-1 to the Centers for Disease Control of Taiwan. In 2003 HIV-1 rates in first-time blood donors military conscripts and pregnant women were measured at 5.2 57.0 and 12.0 per 100 000 respectively. Data from that year indicated HIV-1 rates of 0.09% for intravenous drug users 0.2% for female sex workers 1.9% for patients with sexually transmitted infections and 6.7% for men who have sex with men in saunas or bath houses. Since then the number of people living with HIV-1/AIDS in Taiwan has jumped sharply from an 11% increase in 2003 to a 77% increase in 2004 and a 123% increase in 2005. However after the implementation of a harm-reduction programme a 10% decrease was seen in 2006. The current estimated number of HIV-1/AIDS cases in Taiwan is about 30 000 which suggests that the infection rate there could be greater than that in China: 30 000 per 23 million (1/767) compared with 650 000 per 1.3 billion (1/2000). (excerpt)

Failure to prescribe pneumocystis prophylaxis is associated with increased mortality, even in the cART era: results from the Treat Asia HIV observational database.

BackgroundPneumocystis jiroveci pneumonia (PCP) prophylaxis is recommended for patients with CD4 counts of less than 200 cells/mm3. This study examines the proportion of patients in the TREAT Asia HIV Observational Database (TAHOD) receiving PCP prophylaxis, and its effect on PCP and mortality.MethodsTAHOD patients with prospective follow up had data extracted for prophylaxis using co-trimoxazole, dapsone or pentamidine. The proportion of patients on prophylaxis was calculated for each calendar year since 2003 among patients with CD4 counts of less than 200 cells/mm3. The effect of prophylaxis on PCP and survival were assessed using random-effect Poisson regression models.ResultsThere were a total of 4050 patients on prospective follow up, and 90% of them were receiving combination antiretroviral therapy. Of those with CD4 counts of less than 200 cells/mm3, 58% to 72% in any given year received PCP prophylaxis, predominantly co-trimoxazole. During follow up, 62 patients developed PCP (0.5 per 100 person-years) and 169 died from all causes (1.36/100 person-years). After stratifying by site and adjusting for age, CD4 count, CDC stage and antiretroviral treatment, those without prophylaxis had no higher risk of PCP, but had a significantly higher risk of death (incident rate ratio 10.8, p < 0.001). PCP prophylaxis had greatest absolute benefit in patients with CD4 counts of less than 50 cells/mm3, lowering mortality rates from 33.5 to 6.3 per 100 person-years.ConclusionsApproximately two-thirds of TAHOD patients with CD4 counts of less than 200 cells/mm3 received PCP prophylaxis. Patients without prophylaxis had significantly higher mortality, even in the era of combination ART. Although PCP may be under-diagnosed, these data suggest that prophylaxis is associated with important survival benefits.

Hepatitis B and C virus coinfection in The TREAT Asia HIV Observational Database

Background and Aim:  Most studies of hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection with HIV have been conducted among Western patient populations. This study aims to assess rates of HBV and HCV coinfection, and their impact on response to antiretroviral therapy and mortality, using data from The TREAT Asia HIV Observational Database (TAHOD), a multi‐center cohort of patients with HIV in the Asia–Pacific region.

Characterization of glycine-N-methyltransferase-gene expression in human hepatocellular carcinoma

Messenger RNA differential display was used to study liver‐gene expression in paired tumor and non‐tumor tissues from hepatocellular carcinoma (HCC) patients. mRNA differential display and Northern‐blot analyses showed that a 0.8‐kb cDNA fragment was diminished or absent from the tumorous tissues of 7 HCC patients. The cDNA fragment was sequenced and found to have 98.7% nucleotide sequence homology with human glycine‐N‐methyltransferase cDNA (GNMT). In addition, there was no detectable level of GNMT expression in 4 human HCC cell lines, SK‐Hep1, Hep 3B, HuH‐7 and HA22T, examined by Northern‐blot assay. A full‐length GNMT cDNA clone‐9‐1‐2 was obtained by screening a Taiwanese liver cDNA library. In comparison with the GNMT cDNA sequence reported elsewhere, clone 9‐1‐2 had 4 nucleotide differences resulting in 1 amino‐acid change. Immunohistochemical staining with rabbit anti‐recombinant GNMT serum showed that GNMT protein almost completely disappeared in liver‐cancer cells, while it was abundant in the non‐tumorous liver cells. Down‐regulation of GNMT gene expression may be involved in the pathogenesis of liver cancer. Int. J. Cancer 75:787–793, 1998.© 1998 Wiley‐Liss, Inc.

Immunodeficiency at the start of combination antiretroviral therapy in low-, middle- and high-income countries

Objective:To describe the CD4 cell count at the start of combination antiretroviral therapy (cART) in low-income (LIC), lower middle-income (LMIC), upper middle-income (UMIC), and high-income (HIC) countries. Methods:Patients aged 16 years or older starting cART in a clinic participating in a multicohort collaboration spanning 6 continents (International epidemiological Databases to Evaluate AIDS and ART Cohort Collaboration) were eligible. Multilevel linear regression models were adjusted for age, gender, and calendar year; missing CD4 counts were imputed. Results:In total, 379,865 patients from 9 LIC, 4 LMIC, 4 UMIC, and 6 HIC were included. In LIC, the median CD4 cell count at cART initiation increased by 83% from 80 to 145 cells/&mgr;L between 2002 and 2009. Corresponding increases in LMIC, UMIC, and HIC were from 87 to 155 cells/&mgr;L (76% increase), 88 to 135 cells/&mgr;L (53%), and 209 to 274 cells/&mgr;L (31%). In 2009, compared with LIC, median counts were 13 cells/&mgr;L [95% confidence interval (CI): −56 to +30] lower in LMIC, 22 cells/&mgr;L (−62 to +18) lower in UMIC, and 112 cells/&mgr;L (+75 to +149) higher in HIC. They were 23 cells/&mgr;L (95% CI: +18 to +28 cells/&mgr;L) higher in women than men. Median counts were 88 cells/&mgr;L (95% CI: +35 to +141 cells/&mgr;L) higher in countries with an estimated national cART coverage >80%, compared with countries with <40% coverage. Conclusions:Median CD4 cell counts at the start of cART increased 2000–2009 but remained below 200 cells/&mgr;L in LIC and MIC and below 300 cells/&mgr;L in HIC. Earlier start of cART will require substantial efforts and resources globally.

Glycine N-methyltransferase-/- mice develop chronic hepatitis and glycogen storage disease in the liver.

Glycine N‐methyltransferase (GNMT) affects genetic stability by regulating DNA methylation and interacting with environmental carcinogens. To establish a Gnmt knockout mouse model, 2 lambda phage clones containing a mouse Gnmt genome were isolated. At 11 weeks of age, the Gnmt−/− mice had hepatomegaly, hypermethioninemia, and significantly higher levels of both serum alanine aminotransferase and hepatic S‐adenosylmethionine. Such phenotypes mimic patients with congenital GNMT deficiencies. A real‐time polymerase chain reaction analysis of 10 genes in the one‐carbon metabolism pathway revealed that 5,10‐methylenetetrahydrofolate reductase, S‐adenosylhomocysteine hydrolase (Ahcy), and formiminotransferase cyclodeaminase (Ftcd) were significantly down‐regulated in Gnmt−/− mice. This report demonstrates that GNMT regulates the expression of both Ftcd and Ahcy genes. Results from pathological examinations indicated that 57.1% (8 of 14) of the Gnmt−/− mice had glycogen storage disease (GSD) in their livers. Focal necrosis was observed in male Gnmt−/− livers, whereas degenerative changes were found in the intermediate zones of female Gnmt−/− livers. In addition, hypoglycemia, increased serum cholesterol, and significantly lower numbers of white blood cells, neutrophils, and monocytes were observed in the Gnmt−/− mice. A real‐time polymerase chain reaction analysis of genes involved in the gluconeogenesis pathways revealed that the following genes were significantly down‐regulated in Gnmt−/− mice: fructose 1,6‐bisphosphatase, phosphoenolpyruvate carboxykinase, and glucose‐6‐phosphate transporter. Conclusion: Because Gnmt−/− mice phenotypes mimic those of patients with GNMT deficiencies and share several characteristics with GSD Ib patients, we suggest that they are useful for studies of the pathogenesis of congenital GNMT deficiencies and the role of GNMT in GSD and liver tumorigenesis. (HEPATOLOGY 2007.)

Cohort profile: The PharmAccess African (PASER-M) and the TREAT Asia (TASER-M) monitoring studies to evaluate resistance-HIV drug resistance in sub-Saharan Africa and the Asia-Pacific

This article discusses two multi-centre prospective cohort studies in Africa that assess the prevalence and incidence of HIV in people using the first-line ART treatment. Participants are enrolled in the study for approximately 18 months after which new participants are recruited. The HIV positive people in the study are evaluated during their regular clinic visits. Researchers are collecting information about various HIV subtypes in the affected population incidence of duel infections and disease progression and response to treatment. Due to the various clinics involved in the study the study benefits from a large number of patients with very different backgrounds and disease characteristics.

DC-SIGN mediates avian H5N1 influenza virus infection in cis and in trans

Abstract DC-SIGN, a C-type lectin receptor expressed in dendritic cells (DCs), has been identified as a receptor for human immunodeficiency virus type 1, hepatitis C virus, Ebola virus, cytomegalovirus, dengue virus, and the SARS coronavirus. We used H5N1 pseudotyped and reverse-genetics (RG) virus particles to study their ability to bind with DC-SIGN. Electronic microscopy and functional assay results indicate that pseudotyped viruses containing both HA and NA proteins express hemagglutination and are capable of infecting cells expressing α-2,3-linked sialic acid receptors. Results from a capture assay show that DC-SIGN-expressing cells (including B-THP-1/DC-SIGN and T-THP-1/DC-SIGN) and peripheral blood dendritic cells are capable of transferring H5N1 pseudotyped and RG virus particles to target cells; this action can be blocked by anti-DC-SIGN monoclonal antibodies. In summary, (a) DC-SIGN acts as a capture or attachment molecule for avian H5N1 virus, and (b) DC-SIGN mediates infections in cis and in trans.

Molecular epidemiology of HCV genotypes among injection drug users in Taiwan: Full-length sequences of two new subtype 6w strains and a recombinant form_2b6w.

Human immunodeficiency virus type 1 (HIV‐1) circulating recombinant form (CRF) 07_BC strain has caused serious outbreaks among injection drug users in Taiwan since 2004. The objective of this study was to conduct a molecular epidemiological study of HCV genotypes in intravenous drug users in Taiwan. Blood samples and questionnaires from 591 intravenous drug users infected with HIV‐1 were collected nationwide. In total, 180 samples were selected for HCV genotyping using multiplex PCR and phylogenetic analysis of the core, E1 and NS5B regions. The Inno‐Lipa assay was used to confirm multiple infections with different genotypes. Eighty percent had a single infection with subtype 1b being the most common subtype (24%), 12% had double infections and two had triple infections. In addition, three recombinant forms (RFs)‐2a1a, 3a1b, and 2b6w were identified. Phylogenetic analyses showed that the 3a, 6a, and 6n strains were clustered with strains present in Thailand and mainland China. Full‐length sequence analysis showed that two 6w strains shared 89.4–90.2% sequence homology with the 6(r) strain from the Guangdong Province, China. Bootscan analysis revealed that the recombination breakpoint of RF_2b6w was located at the NS2‐NS3 junction. In summary, the distribution of HCV genotypes among Taiwanese intravenous drug users was complex and more than 12% of the drug users were infected with more than one genotype of HCV. J. Med. Virol. 82:57–68, 2010.