Biomedical subjects

Pin-Nan Cheng

Publications and source records attributed to Pin-Nan Cheng.

12 recordsLinked to original sources

PubMed2006

CD81 down-regulation on B cells is associated with the response to interferon-alpha-based treatment for chronic hepatitis C virus infection.

The lymphocytic CD81 molecule, capable of modulating type-1/-2 T-helper responses and serving as a putative receptor for hepatitis C virus (HCV), might influence the outcome of anti-HCV treatment. This study characterized the interferon-alpha-induced alteration of lymphocytic CD81. The CD81 levels in healthy subjects and naïve chronic HCV patients were compared, with the results showing that the two groups had comparable surface CD81 levels for total peripheral blood lymphocytes, subpopulation-B, -T, and -NK cells. In vitro interferon-alpha treatment could suppress the CD81 expression from both groups. Subsequently, we compared the in vitro interferon-alpha modulatory effects on lymphocytic CD81 from patients having received anti-HCV therapy with either sustained virological response (SVR) or without SVR. There was a significant down-regulation of the B-cell's CD81 only in the SVR group. The CD81 modulation was further investigated using Daudi lymphoid cell line, showing declined surface CD81 levels following treatment with interferon-alpha, interferon-beta or polyI:C. Thus, interferons could directly decrease CD81 expression. The interferon-alpha effect could be restored by 2-aminopurine, suggesting that double-stranded RNA activated kinase might be involved in the suppression of CD81. In conclusion, CD81 down-regulation is a primary host response to interferon-alpha-based therapy and an immunophenotype associated with anti-HCV SVR.

Adult↗

PubMed2006

Seroprevalence of hepatitis E virus infection among institutionalized psychiatric patients in Taiwan.

BACKGROUND: Hepatitis E virus infection (HEV) remains unclear in institutionalized psychiatric patients. OBJECTIVES: To investigate the prevalence and risk factors of HEV infection in a psychiatric institution in Taiwan. STUDY DESIGN: A total of 754 patients with psychiatric disorders were enrolled in the study. Clinical features, review of patient charts, and interviews with families were recorded for analysis. Antibody to HEV was tested using a commercial enzyme-linked immunosorbent assays. RESULTS: The prevalence of HEV infection in institutionalized patients was as high as 14.5%. Males had higher prevalence than females. It was also found prevalence increased significantly by age group. When compared with patients 30 years old or less, those in the 31-40 year old age group had an odds ratio of 4.89 [95% confidence interval (CI), 1.15-20.82], 41-50 years old of 6.30 (95% CI, 1.48-26.83), and 50 years or older of 6.20 (95% CI, 1.44-26.74). In multivariate logistic regression analysis, age and male gender were the independent risk factors. CONCLUSIONS: Institutionalized psychiatric patients had higher prevalence of HEV infection. In addition, there was an age-related increase in exposure to HEV with males that had a higher HEV seropositivity.

Adult↗

PubMed2006

Is [N+-H...O] hydrogen bonding the most important noncovalent interaction in macrocycle-dibenzylammonium ion complexes?

We report a new host molecule in which one diethylene glycol chain (i.e., a loop possessing only three oxygen atoms) incorporated along with two phenolic aromatic rings is linked by a xylene spacer into a macroring. The design of the molecular structure of this macrocycle "amplifies" any potential [cation...pi], [N+-H...pi], and [N+C-H...pi] interactions between the dibenzylammonium (DBA+) ion and the phenolic rings of the macrocycle; as such, these species display a very strong binding affinity in CD3NO2 (Ka = 15,000 M(-1)). The macroring also coordinates to bipyridinium ions in a [2]pseudorotaxane fashion, which makes it the smallest macrocycle (i.e., a 25-membered ring) known to complex both DBA+ and bipyridinium ions in solution. To confirm unambiguously that these pseudorotaxanes exist in solution, we synthesized their corresponding interlocked molecules, namely rotaxanes and catenanes.

Benzylammonium Compounds↗

PubMed2006

[3]Pseudorotaxane-like complexes formed between bipyridinium dications and bis-p-xylyl[26]crown-6.

[structure: see text]. The crown ether BPX26C6 forms a [3]pseudorotaxane-like complex with the N,N'-dimethyl-4,4'-bipyridinium dication both in solution and in the solid state. The facile one-pot synthesis of a [2]rotaxane from neutral precursors-BPX26C6, 4,4'-dipyridyl, and 3,5-di-tert-butylbenzyl bromide-suggests that BPX26C6 may bind to (mono)pyridinium cations in a [2]pseudorotaxane-like manner.

Journal Article↗

PubMed2006

A macrocycle/molecular-clip complex that functions as a quadruply controllable molecular switch.

Herein, we report the synthesis of a molecular clip with TTF side-walls and its binding behavior towards electron-deficient guests, namely the formation of macrocycle/molecular-clip supramolecular complexes in solution. Four different sets of external stimuli--the K(+)/[2.2.2]cryptand, NH(4) (+)/Et(3)N and (p-BrPh)(3)NSbCl(6)/Zn pairs, and heating/cooling cycles-control the movement of this molecular switch between its threaded and unthreaded states and provide color changes that are observable by the naked eye. This macrocycle/molecular-clip complex system can be considered not only as a quadruple-use molecular switch, but can also be operated by three of these stimuli as a three-input molecular NOR-functioning logic gate that may be monitored by UV-visible spectroscopy.

Crown Ethers↗

PubMed2005

Hepatotoxicity associated with acarbose therapy.

OBJECTIVE: To report a case of acarbose-induced hepatotoxicity and compare other reported cases from the literature. CASE SUMMARY: A 57-year-old woman with type 2 diabetes mellitus for about 10 years had been treated with insulin glargine 20 units/day since December 19, 2002. Acarbose 100 mg 3-times-daily add-on therapy for inadequate glycemic control was started on June 5, 2003. Six months later, the woman complained of gastrointestinal discomfort; the acarbose dose was decreased to 50 mg 3 times daily thereafter. Laboratory examination later revealed alanine aminotransferase (ALT) 640 U/L (upper reference value 55). To elucidate the possibilities of adverse reactions caused by concurrent use of nutritional supplements and medication, we discontinued propolis extract, Ginkgo biloba, placeta extract, and estrogen. Although no remarkable symptoms were noted thereafter, the abnormal ALT values persisted, and no definite viral or autoimmune etiologies were identified. Acarbose was discontinued in August 2004; aspartate aminotransferase and ALT values returned to normal in October 2004. DISCUSSION: In addition to ruling out other possible etiologic factors, we assessed the probability of acarbose-induced hepatotoxicity by observing the close time relationship between drug administration and the development of signs and symptoms, as well as the close time relationship between drug withdrawal and the normalization of abnormal liver function test values. An objective causality assessment revealed that an adverse drug reaction was probable as determined by both the Naranjo probability scale and the Roussel Uclaf Causality Assessment Method score. CONCLUSIONS: Although acarbose-induced hepatotoxicity appears to be uncommon, diabetic patients receiving long-term acarbose therapy should be closely monitored for this adverse effect.

Acarbose↗

PubMed2005

A switchable macrocycle-clip complex that functions as a NOR logic gate.

We have synthesized a new molecular switch-based on a macrocycle-clip complex-whose switching behavior not only can be controlled through the use of either K+-[2,2,2]cryptand or NH4+-Et3N systems but also provides color changes that are visible to the naked eye; consequently, this system operates as a two-input NOR functioning molecular logic gate.

Journal Article↗

PubMed2002

A reverse-transcription competitive PCR assay based on chemiluminescence hybridization for detection and quantification of hepatitis C virus RNA.

A reverse-transcription competitive PCR (RT-cPCR) combined with chemiluminescence hybridization was designed for the detection and quantitative determination of serum hepatitis C virus (HCV) RNA. The concentration of HCV RNA was calculated based on an external standard curve that was generated by coamplification of internal competitor and target sequences in serial dilutions. The detection limit of the chemiluminescence RT-cPCR was 100 copies/ml (94 IU/ml). Meanwhile, the linear range for quantitation extended from 850 copies/ml (795 IU/ml) to 4.95x10(7) copies/ml. The performance of the current assay for measuring circulating HCV levels from 26 anti-HCV-antibody positive patients was compared with that of branched-chain DNA (bDNA) and nested RT-PCR assays. Eighteen patients had HCV RNA levels that exceeded the quantitation limit by the chemiluminescence RT-cPCR, but only 11 patients were quantitation-positive by the bDNA. A significant correlation of the quantitation values was found between the chemiluminescence RT-cPCR and the bDNA (R2=0.8391). Among the eight patients with HCV RNA titers below the quantitation limit, four remained positive by the chemiluminescence cRT-PCR, demonstrating the results in agreement with those using the nested RT-PCR. Furthermore, good linearity was revealed for the HCV genotypes 1b, 2a, 2b in 3-order magnitude diluted serum samples. In conclusion, the proposed chemiluminescence RT-cPCR method can detect quantitatively HCV RNA as accurately as the bDNA method and has sensitivity as high as nested RT-PCR.

Branched DNA Signal Amplification Assay↗

PubMedDate not supplied

Molecular evidence for transmission of GB virus-C/Hepatitis G virus infection within family: close relationship between mother and child.

BACKGROUND/AIMS: GBV-C/Hepatitis G virus (HGV) is transmitted parentally, but some of the transmitted routes are still unclear. This study was conducted to investigate the relationship of family members in the transmission of HGV. METHODOLOGY: The study group enrolled 11 children from four index mothers with HGV viremia, whereas the control group had 14 children from seven matched mothers without HGV infection. Detection of circulating HGV RNA and anti-E2 antibody was conducted. Comparison of partially HGV nucleotide sequences at the 5' non-coding and non-structure 5 regions was performed among the infected family members. RESULTS: There was higher HGV viremia in children from the index mothers with HGV infection than those from mothers in control (3/11 vs. 0/14, p < 0.05). Nucleotide sequences analysis showed higher similarity between mothers and their children in the same family (98.6% to 100%) than between mothers of different families (87.8% to 92.4%). The phylogenetic construction also demonstrated distinct sequence clusters for mother and child/children of each family. CONCLUSIONS: The relationship of HGV transmission between mother and children was closely related in family. Spread of HGV might occur intrafamilially.

Adolescent↗

PubMedDate not supplied

High-dose interferon-alpha 2b plus ribavirin combination therapy for GB virus-C/hepatitis G virus infection--a study in patients with chronic hepatitis C.

BACKGROUND/AIMS: The efficacy of interferon-alpha and ribavirin combination therapy for GB virus C/hepatitis G virus infection is not well understood. We previously conducted a double-blind, placebo-controlled trial using high-dose interferon-alpha 2b with or without ribavirin for patients with interferon-alpha-relapsed chronic hepatitis C. METHODOLOGY: Fifty-two patients were randomly assigned and completed the 24-week treatment of interferon-alpha 2b (6 million units three times per week) plus ribavirin (1000 to 1200 mg/daily), or plus a matched placebo. Patients were then followed for an additional 24 weeks. RESULTS: Of the 52 patients, 5 patients (9.6%) had hepatitis G virus viremia before or during enrollment. Two patients received interferon-alpha 2b alone and three patients received interferon-alpha 2b and ribavirin combination therapy. At the end of treatment, all of the 5 patients had undetectable hepatitis G virus RNA in sera. Early loss of hepatitis G virus RNA at week 4 of treatment was observed in the 2 patients on combination therapy. Hepatitis G virus RNA reappeared at the end of follow-up in these 5 patients. CONCLUSIONS: In conclusion, interferon-alpha 2b and ribavirin combination therapy could induce earlier loss of hepatitis G virus RNA than interferon-alpha 2b alone. Either interferon-alpha 2b alone or interferon-alpha 2b and ribavirin combination therapy achieved transient but not sustained virological response to hepatitis G virus viremia.

Adult↗

PubMedDate not supplied

Immune response to hepatitis B vaccine of subjects with isolated antibody to hepatitis B core antigen.

BACKGROUND/AIMS: For subjects with isolated antibody to hepatitis B core antigen, vaccination can help discriminate various diagnostic possibilities. The aim of this study was to evaluate the clinical significance of isolated antibody to hepatitis B core antigen. METHODOLOGY: A total of 1403 hospital personnel were screened for hepatitis B surface antigen, antibody to hepatitis B surface antigen and antibody to hepatitis B core antigen by radioimmunoassay. Thirty subjects were confirmed to have isolated antibody to hepatitis B core antigen, and 278 subjects lacked all hepatitis B virus markers. Twenty-five of the 30 subjects (group I) and 136 of the 278 subjects (group II) were vaccinated by hepatitis B vaccine at months 0, 1, 6; followed by checking antibody to hepatitis B surface antigen in geometric mean titres at months 1, 2, and 7. RESULTS: The geometric mean titres of antibody to hepatitis B surface antigen were higher in group I than in group II at month 1 (9.1 +/- 8.6 vs. 3.2 +/- 6.0, p < 0.05), and were lower in group I than group II at month 7 (267.2 +/- 17.2 vs. 2315.3 +/- 5.1, p < 0.05). Furthermore, primary response was higher in group II than group I (73.3% vs. 35.7%, p < 0.05), but anamnestic response and non-response were higher in group I than group II (50% vs 26.7%, p = 0.116 with a trend; 14.3% vs. 0%, p < 0.01, respectively). CONCLUSIONS: For subjects with isolated antibody to hepatitis B core antigen, a strategy concerning sequential vaccination followed by checking antibody to hepatitis B surface antigen might be adopted to avoid two extra vaccine dosages and ineffective vaccination.

Adult↗

PubMedDate not supplied

Interspousal transmission of hepatitis C virus: application of comparing the variability of HVR1 nucleotide region.

BACKGROUND/AIMS: The interspousal transmission of hepatitis C virus (HCV) has been a controversial issue in previous studies. We thus aim to investigate the possibility of HCV transmission between spouses by comparing the variability of HCV hypervariable region 1 (HVR1) between spouses and non-spouses. METHODOLOGY: Four spouses both positive for anti-HCV antibody and HCV RNA were enrolled in our study. Reverse transcriptional polymerase chain reaction (PCR) of HVR1 region was done from each patient for blood samples. The amplified PCR products were molecularly cloned, and eight to ten clones from each patient were analyzed. In addition to the phylogenetic analysis, comparing the variability of nucleotide and deduced amino acid sequences of HVR1 and outside HVR1 from these clones by a computer software program PHYLIP version 3.57 was performed in each patient, between spouse and among non-family patients. RESULTS: All eight patients were infected with genotype Ib HCV. The sequences of eight to ten clones of HCV HVR1 in each patient showed quasispecies nature of HCV. Moreover, the variabilities of nucleotide sequence and deduced amino acid sequence of HVR1 were much higher than those outside of HVR1. Between spouses, the variabilities of HVR1 were significantly lower (p<0.001) than those of non-family members in 3 of 4 families. Clones of the same patient displayed the closest relationship in the phylogenetic tree. In addition, spouses of three families showed a closer relationship than other non-family patients. CONCLUSIONS: This study strongly suggests that sexual transmission does exist, which can be confirmed by comparing the variability of HVR1 nucleotide region of HCV.

Female↗