Effects of dextromethorphan on nicotine-induced reward, behavioral sensitization, withdrawal signs, and drug seeking-related behavior in rats

Introduction

Tobacco products are addictive, with nicotine serving as the major addictive ingredient. Chronic tobacco use or chronic administration of nicotine alone results in both physiological and psychological dependence. Our previous studies indicated that dextromethorphan (DM) could effectively attenuate dependence of morphine and methamphetamine. Thus, we further investigated the possible effects of DM on nicotine dependence.

Methods

Conditioned place preference (CPP) test was used to examine nicotine-induced rewarding effects as well as the drug-seeking related behavior in rats. Nicotine dependence was induced by continuous subcutaneous infusion of nicotine via an osmotic minipump for 7 days and abstinence was initiated by removal of the pump. Withdrawal signs were observed and quantified. Locomotor activity was measured to determine the behavioral sensitization induced by nicotine. To investigate the activity of mesolimbic dopaminergic neuronal activity in correlation with the effects of nicotine, the animals were sacrificed and the nucleus accumbens (NAc), dorsal striatum (DS) and medial prefrontal cortex (mPFC) were dissected and used to determine the contents of dopamine and its metabolites by HPLC.

Results

Our results showed that DM could suppress nicotine-induced rewarding effect and drug seeking-related behavior. In addition, co-administration and post-treatment of DM could both attenuate nicotine withdrawal signs. Moreover, DM could suppress nicotine-induced behavioral sensitization. In neurochemical experiments, co-administration and post-treatment of DM abolished nicotine-induced increase of the DA turnover rate in the mPFC, but not in the NAc and DS.

Conclusions

These results suggest that DM have a great therapeutic potential in the treatment of nicotine dependence.

Implications

Our results showed that dextromethorphan could suppress nicotine-induced rewarding effect and drug seeking-related behaviour. In addition, co-administration and post-treatment of dextromethorphan could both attenuate nicotine withdrawal signs. Moreover, dextromethorphan could suppress nicotine-induced behavioural sensitization. In neurochemical experiments, co-administration and post-treatment of dextromethorphan abolished nicotine-induced increase of the dopamine turnover rate in the medial prefrontal cortex, but not in the nucleus accumbens and dorsal striatum. These results suggest that dextromethorphan have a great therapeutic potential in the treatment of nicotine dependence.

Sex Difference of Angiotensin IV-, LVV-Hemorphin 7-, and Oxytocin-Induced Antiallodynia at the Spinal Level in Mice With Neuropathic Pain

BACKGROUND

We demonstrated previously that angiotensin IV (Ang IV) and LVV-hemorphin 7 (LVV-H7) act through the blockade of insulin-regulated aminopeptidase to decrease oxytocin degradation, thereby causing antihyperalgesia at the spinal level in rats. We determined that intrathecal oxytocin can induce significant antihyperalgesia in male rats with inflammation but not in female rats. Thus, we speculate that Ang IV, LVV-H7, and oxytocin can induce antiallodynia, which could be of great therapeutic potential. Because the antihyperalgesia by using these peptides was with sex difference, their possible antiallodynia was examined in male and female mice for comparison. We investigated whether Ang IV, LVV-H7, and oxytocin produce antiallodynia at the spinal level in mice and whether this antiallodynia differs between the sexes.

METHODS

Partial sciatic nerve ligation surgery was performed on adult male and female C57BL/6 mice from the same litter (25-30 g). The effects of intrathecal injections of Ang IV (25.8 nmol), LVV-H7 (27.2 nmol), and oxytocin (0.125 or 1.25 nmol) were assessed through the von Frey test 3 days after partial sciatic nerve ligation.

RESULTS

Intrathecal injection of Ang IV, LVV-H7, and oxytocin all produced a potent antiallodynia in male mice. However, these antiallodynia effects were either extremely weak or absent in female mice at the same dose.

CONCLUSIONS

Intrathecal Ang IV, LVV-H7, and oxytocin can all cause significant antiallodynia in male mice. The Ang IV-, LVV-H7-, and oxytocin-induced antiallodynia effects differed between the sexes at the spinal level in mice.

Release parameters during progressive degeneration of dopamine neurons in a mouse model reveal earlier impairment of spontaneous than forced behaviors

To determine the role of reduced dopaminergic transmission for declines of forced versus spontaneous behavior, we used a model of Parkinson's disease with progressive degeneration of dopamine (DA) neurons, the MitoPark mouse. Mice were subjected to rotarod tests of motor coordination, and open field and cylinder tests for spontaneous locomotor activity and postural axial support. To measure DA release in dorsal striatum and the shell of Nucleus Accumbens (NAc), we used ex vivo fast-scan cyclic voltammetry in 6- to 24-week-old mice. To determine decline of DA transporter function, we used 18FE-PE2I positron emission tomography. We show here that fast-scan cyclic voltammetry is a sensitive tool to detect evoked DA release dysfunction in MitoPark mice and that electrically evoked DA release is affected earlier in nigrostriatal than mesolimbic DA systems. DA reuptake was also affected more slowly in NAc shell. Positron emission tomography data showed DA uptake to be barely above detection levels in 16- and 20-week-old MitoPark mice. Rotarod performance was not impaired until mice were 16 weeks old, when evoked DA release in striatum had decreased to ≈ 40% of wild-type levels. In contrast, impairment of open field locomotion and rearing began at 10 weeks, in parallel with the initial modest decline of evoked DA release. We conclude that forced behaviors, such as motivation not to fall, can be partially maintained even when DA release is severely compromised, whereas spontaneous behaviors are much more sensitive to impaired DA release, and that presumed secondary non-dopaminergic system alterations do not markedly counteract or aggravate effects of severe impairment of DA release. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.

Nicotine-Induced Conditional Place Preference Is Affected by Head Injury: Correlation with Dopamine Release in the Nucleus Accumbens Shell

BACKGROUND

Traumatic brain injury is known to impact dopamine-mediated reward pathways, but the underlying mechanisms have not been fully established.

METHODS

Nicotine-induced conditional place preference was used to study rats exposed to a 6-psi fluid percussion injury with and without prior exposure to nicotine. Preference was quantified as a score defined as (C1 - C2) / (C1 + C2), where C1 is time in the nicotine-paired compartment and C2 is time in the saline-paired compartment. Subsequent fast-scan cyclic voltammetry was used to analyze the impact of nicotine infusion on dopamine release in the shell portion of the nucleus accumbens. To further determine the influence of brain injury on nicotine withdrawal, nicotine infusion was administered to the rats after fluid percussion injury. The effects of fluid percussion injury on conditional place preference after prior exposure to nicotine and abstinence or withdrawal from nicotine were also assessed.

RESULTS

After traumatic brain injury, dopamine release was reduced in the nucleus accumbens shell, and nicotine-induced conditional place preference preference was significantly impaired. Preference scores of control, sham-injured, and fluid percussion injury groups were 0.1627±0.04204, 0.1515±0.03806, and -0.001300±0.04286, respectively. Nicotine-induced conditional place preference was also seen in animals after nicotine pretreatment, with a conditional place preference score of 0.07805±0.02838. Nicotine preexposure substantially increased tonic dopamine release in sham-injured animals, but it did not change phasic release; nicotine exposure after fluid percussion injury enhanced phasic release, though not to the same levels seen in sham-injured rats. Conditioned preference was related not only to phasic dopamine release (r=0.8110) but also to the difference between tonic and phasic dopamine levels (r=0.9521).

CONCLUSIONS

Traumatic brain injury suppresses dopamine release from the shell portion of the nucleus accumbens, which in turn significantly alters reward-seeking behavior. These results have important implications for tobacco and drug use after traumatic brain injury.

Exercise Ameliorates Motor Deficits and Improves Dopaminergic Functions in the Rat Hemi-Parkinson's Model

To determine the influences of exercise on motor deficits and dopaminergic transmission in a hemiparkinson animal model, we measured the effects of exercise on the ambulatory system by estimating spatio-temporal parameters during walking, striatal dopamine (DA) release and reuptake and synaptic plasticity in the corticostriatal pathway after unilateral 6-OHDA lesions. 6-OHDA lesioned hemiparkinsonian rats were exercised on a fixed speed treadmill for 30 minutes per day. Controls received the same lesion but no exercise. Animals were subsequently analyzed for behavior including gait analysis, rotarod performance and apomorphine induced rotation. Subsequently, in vitro striatal dopamine release was analyzed by using FSCV and activity-dependent plasticity in the corticostriatal pathway was measured in each group. Our data indicated that exercise could improve motor walking speed and increase the apomorphine-induced rotation threshold. Exercise also ameliorated spatiotemporal impairments in gait in PD animals. Exercise increased the parameters of synaptic plasticity formation in the corticostriatal pathway of PD animals as well as the dynamics of dopamine transmission in PD animals. Fixed speed treadmill training 30 minutes per day could ameliorate spatial-temporal gait impairment, improve walking speed, dopamine transmission as well as corticostriatal synaptic plasticity in the unilateral 6-OHDA lesioned rat model.

Historical epidemiology of hepatitis C virus in select countries-volume 4

Due to the introduction of newer, more efficacious treatment options, there is a pressing need for policy makers and public health officials to develop or adapt national hepatitis C virus (HCV) control strategies to the changing epidemiological landscape. To do so, detailed, country-specific data are needed to characterize the burden of chronic HCV infection. In this study of 17 countries, a literature review of published and unpublished data on HCV prevalence, viraemia, genotype, age and gender distribution, liver transplants and diagnosis and treatment rates was conducted, and inputs were validated by expert consensus in each country. Viraemic prevalence in this study ranged from 0.2% in Hong Kong to 2.4% in Taiwan, while the largest viraemic populations were in Nigeria (2 597 000 cases) and Taiwan (569 000 cases). Diagnosis, treatment and liver transplant rates varied widely across the countries included in this analysis, as did the availability of reliable data. Addressing data gaps will be critical for the development of future strategies to manage and minimize the disease burden of hepatitis C.

The present and future disease burden of hepatitis C virus infections with today's treatment paradigm: Volume 4

Factors influencing the morbidity and mortality associated with viremic hepatitis C virus (HCV) infection change over time and place, making it difficult to compare reported estimates. Models were developed for 17 countries (Bahrain, Bulgaria, Cameroon, Colombia, Croatia, Dominican Republic, Ethiopia, Ghana, Hong Kong, Jordan, Kazakhstan, Malaysia, Morocco, Nigeria, Qatar and Taiwan) to quantify and characterize the viremic population as well as forecast the changes in the infected population and the corresponding disease burden from 2015 to 2030. Model inputs were agreed upon through expert consensus, and a standardized methodology was followed to allow for comparison across countries. The viremic prevalence is expected to remain constant or decline in all but four countries (Ethiopia, Ghana, Jordan and Oman); however, HCV-related morbidity and mortality will increase in all countries except Qatar and Taiwan. In Qatar, the high-treatment rate will contribute to a reduction in total cases and HCV-related morbidity by 2030. In the remaining countries, however, the current treatment paradigm will be insufficient to achieve large reductions in HCV-related morbidity and mortality.

Strategies to manage hepatitis C virus infection disease burden-Volume 4

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 17 countries in Africa, Asia, Europe, Latin America and the Middle East, and interventions for achieving the Global Health Sector Strategy on viral hepatitis targets-"WHO Targets" (65% reduction in HCV-related deaths, 90% reduction in new infections and 90% of infections diagnosed by 2030) were considered. Scaling up treatment and diagnosis rates over time would be required to achieve these targets in all but one country, even with the introduction of high SVR therapies. The scenarios developed to achieve the WHO Targets in all countries studied assumed the implementation of national policies to prevent new infections and to diagnose current infections through screening.

Melatonin reverses morphine tolerance by inhibiting microglia activation and HSP27 expression

AIMS

Melatonin has been reported to attenuate opioid tolerance. In this study, we explored the possible mechanism of melatonin in diminishing morphine tolerance.

MAIN METHODS

Two intrathecal (i.t.) catheters were implanted in male Wistar rats for drug delivery. One was linked to a mini-osmotic pump for morphine or saline infusion. On the seventh day, 50μg of melatonin or vehicle was injected through the other catheter instantly after discontinuation of morphine or saline infusion; 3h later, 15μg of morphine or saline was injected. The antinociceptive response was then measured using the tail-flick test every 30min for 120min.

KEY FINDINGS

The results showed that chronic morphine infusion elicited antinociceptive tolerance and upregulated heat shock protein 27 (HSP27) expression in the dorsal horn of the rat spinal cord. Melatonin pretreatment partially restored morphine's antinociceptive effect in morphine-tolerant rats and reversed morphine-induced HSP27 upregulation. In addition, chronic morphine infusion induced microglial cell activation and was reversed by melatonin treatment.

SIGNIFICANCE

The present study provides evidence that melatonin, acting via inhibiting morphine-induced neuroinflammation, can be useful as a therapeutic adjuvant for patients under long-term opioid treatment for pain relief.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Effect of naltrexone on neuropathic pain in mice locally transfected with the mutant μ-opioid receptor gene in spinal cord

BACKGROUND AND PURPOSE

Opioid antagonists, such as naloxone and naltrexone, exhibit agonistic properties at the mutated μ receptor, MOR-S196ACSTA. In our previous study, systemic naloxone (10 mg·kg(-1) , s.c.) elicited antinociceptive effect without the induction of tolerance, dependence or rewarding effect in mice 2 weeks after intrathecal administration of double-stranded adeno-associated virus-MOR-S196ACSTA-eGFP. Here, we have investigated if this antinociceptive paradigm would be effective in a mouse model of neuropathic pain.

EXPERIMENTAL APPROACH

Spinal nerves were ligated in male C57BL/6 mice 3 or 4 weeks after intrathecal injection of the lentivirus encoding the construct of MOR-S196ACSTA-eGFP (LV-MOR-S196ACSTA). Anti-allodynic effects of daily s.c.injections of saline, naltrexone (10 mg·kg(-1) ) or morphine (10 mg·kg(-1) ) were assessed by the von Frey test. After 14 days of treatment with saline, naltrexone or morphine, signs of natural withdrawal were measured at 22 and 46 h after the last injection. To determine the rewarding effects induced by morphine or naltrexone, the conditioned place preference test was carried out.

KEY RESULTS

Anti-allodynic effects, as measured by von Frey test, increased after naltrexone or morphine treatment in mice transfected with LV-MOR-S196ACSTA in the spinal cord. Cessation of treatment with morphine, but not naltrexone, induced natural withdrawal and rewarding effects.

CONCLUSIONS AND IMPLICATIONS

Systemic injection of naltrexone after the expression of a mutant μ opioid receptor, MOR-S196ACSTA, in the spinal cord may have therapeutic potential for chronic neuropathic pain, without the development of dependence or addiction.

LINKED ARTICLES

This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.

Naloxone can act as an analgesic agent without measurable chronic side effects in mice with a mutant mu-opioid receptor expressed in different sites of pain pathway

Midbrain periaqueductal gray (PAG) and spinal cord dorsal horn are major action sites of opioid analgesics in the pain pathway. Our previous study has shown that opioid antagonists activate MORS196A-CSTA (a mutant of mu-opioid receptor) as full agonists in vitro cell models and naloxone showed antinociceptive effects after the expression of MORS196A-CSTA in the spinal cord in mice. The purpose of this study is to investigate the site-directed antinociceptive effects of naloxone in mice injected with dsAAV-MORS196A-CSTA-EGFP at spinal cord or at periaqueductal gray. MORS196A-CSTA-EGFP was administered to ICR mice using dsAAV as vector. We measured MORS196A-CSTA-EGFP expression by detecting the EGFP visualization with a fluorescence microscope. The antinociceptive effect of naloxone was determined by tail-flick test and hot plate test. Drug rewarding effect was evaluated by the conditioned place preference test. Naloxone (10 mg/kg, s.c.) elicited both supraspinal and spinal antinociceptive responses in mice injected with the virus at PAG while only spinal antinociceptive response was observed in mice injected with virus at dorsal horn region. Chronic naloxone treatment did not induce physical dependence or rewarding effect in mice injected with MORS196A-CSTA-EGFP in spinal cord or PAG. These data suggest that the observed naloxone-induced antinociceptive response is the consequence of the local expression of MORS196A-CSTA at specific sites of pain pathway. Injection of such MOR mutant and the systemic administration of naloxone can be a new strategy in the management of chronic pain without the various side effects associated with the use of morphine.

NR2B subunit of NMDA receptor at nucleus accumbens is involved in morphine rewarding effect by siRNA study

BACKGROUND

Chronic use of morphine causes rewarding effects and behavioral sensitization, which may lead to the development of craving for morphine. A number of studies indicate that the NMDA receptors may be involved in these effects, especially the NR2B-containing NMDA receptors. It is also well recognized that the nucleus accumbens (NAc) and the ventral tegmental area (VTA) are involved in drug addiction, including morphine addiction.

AIMS

In this study, we further investigate the role of the NR2B subunit of NMDA receptors at NAc or VTA in morphine rewarding effects and behavioral sensitization.

METHODS AND RESULTS

The siRNA against the NR2B subunit of NMDA receptors was locally injected to decrease the expression of NR2B at NAc or posterior VTA in male Sprague-Dawley (S.D.) rats in the present study. The rats were then treated with morphine chronically. A conditioned place preference (CPP) test was used to examine the rewarding effect, and locomotor activity was measured to determine the behavioral sensitization induced by chronic morphine treatment. Results showed that morphine-induced rewarding behavior but not behavioral sensitization was abolished when the NR2B subunit of NMDA receptors at the NAc were significantly decreased. The dopamine turnover rate was not altered by the decrease of NR2B subunit at NAc.

CONCLUSION

These findings suggest that the NR2B subunit of NMDA receptors at the NAc is involved in morphine-induced rewarding effect and may not be through directly interacting with dopamine neurons.

Intrathecal delivery of a mutant micro-opioid receptor activated by naloxone as a possible antinociceptive paradigm

Direct injection of double-stranded adeno-associated virus type 2 (dsAAV2) with a mu-opioid receptor (MOR) mutant [S4.45(196)A], and a reporter protein (enhanced green fluorescent protein) into the spinal cord (S2/S3) dorsal horn region of ICR mice resulted in antinociceptive responses to systemic injection of opioid antagonist naloxone without altering the acute agonist morphine responses and no measurable tolerance or dependence development during subchronic naloxone treatment. To develop further such mutant MORs into a therapeutic agent in pain management, a less invasive method for virus delivery is needed. Thus, in current studies, the dsAAV2 was locally injected into the subarachnoid space of the spinal cord by intrathecal administration. Instead of using the MORS196A mutant, we constructed the dsAAV2 vector with the MORS196ACSTA mutant, a receptor mutant in which naloxone has been shown to exhibit full agonistic properties in vitro. After 2 weeks of virus injection, naloxone (10 mg/kg s.c.) elicited antinociceptive effect (determined by tail-flick test) without tolerance (10 mg/kg s.c., b.i.d. for 6 days) and significant withdrawal symptoms. On the other hand, subchronic treatment with morphine (10 mg/kg s.c., b.i.d.) for 6 days induced significant tolerance (4.8-fold) and withdrawal symptoms. Furthermore, we found that morphine, but not naloxone, induced the rewarding effects (determined by conditioned place preference test). These data suggest that local expression of MORS196ACSTA in spinal cord and systemic administration of naloxone has the potential to be developed into a new strategy in the management of pain without addiction liability.

Decoy receptor 3 ameliorates experimental autoimmune encephalomyelitis by directly counteracting local inflammation and downregulating Th17 cells

To investigate the therapeutic potential of decoy receptor 3 (DcR3) in multiple sclerosis (MS), we used intrathecal (IT) administration of DcR3 into C57/BL6 mice with experimental autoimmune encephalomyelitis (EAE). DcR3 significantly ameliorated EAE symptoms as shown by a lower clinical score and less inflammation in the spinal cord. The expression of TNF-alpha, IFN-gamma, and IL-17 was lower in the spinal cord in IT DcR3-treated mice. Flow cytometry showed a drastic reduction in IL-17-producing CD4 T cells, slightly fewer IFN-gamma producing CD4 T cells and more IL-4-producing CD4 T cells isolated from the central nervous system (CNS) of IT DcR3-treated mice than of controls. Myelin oligodendrocyte glycoprotein (MOG)-specific T cell proliferation was significantly inhibited in DcR3-treated mice. The IL-17 concentration was lower and the IL-4 concentration higher in the supernatants of MOG-stimulated splenocytes from DcR3-treated mice. An adoptive transfer study showed that splenocytes from DcR3-treated mice retained this disease-inhibiting ability. Our data suggest that DcR3 has potential as a suppressor of CNS inflammation in EAE, which may be attributed to either direct inhibition of CNS inflammation or suppression of encephalitogenic Th17 cells. In conclusion, we demonstrate a therapeutic effect of DcR3 in EAE, suggesting its potential for treating human MS.

IL-10 promoter gene polymorphisms and sustained response to combination therapy in Taiwanese chronic hepatitis C patients

BACKGROUND AND AIMS

Host genetic factors may affect clinical outcomes of hepatitis C virus (HCV) infection; however, the possible mechanisms remain largely unknown. The role of immunopathogenesis in chronic hepatitis C leads to extensive exploration of host immunity including inflammatory cytokines.

METHODS

We examined interleukin 10 (IL-10) promoter gene polymorphisms at positions -1082, -819, and -592 relative to transcription start site and studied their association with response to 24 weeks of pegylated interferon plus ribavirin treatment in 143 chronic hepatitis C patients, of whom 97 (67.8%) achieved a sustained virologic response (SVR). In addition, 134 healthy adults were used as controls.

RESULTS

Of chronic hepatitis C patients, 111 (77.6%) were genotype 1 infection, 32 (22.4%) were genotype 2 infection. Patients with sustained virologic response were younger and had higher pretreatment ALT levels than those without. No statistical difference was found between chronic hepatitis C patients who achieved SVR or not in terms of gender, HCV genotype, pretreatment HCV RNA levels, and severity of liver disease. The serum IL-10 levels were comparable between healthy controls and chronic hepatitis C patients as well as between HCV patients with and without SVR. The distribution of IL-10 promoter gene polymorphisms at positions -1082, -819, and -592 relative to transcription start site was comparable between HCV patients and healthy controls as well as HCV patients with and without SVR. A high frequency of ATA haplotype of common IL-10 promoter gene SNPs was found in both chronic hepatitis C patients (70.3%) and healthy controls (69.8%). However, ATA haplotype was not associated with SVR in chronic hepatitis C patients.

CONCLUSIONS

Our data fail to demonstrate the influence of IL-10 promoter gene polymorphisms on the response to combination therapy in Taiwanese chronic hepatitis C patients. The impact of genetic variations in IL-10 haplotype on the response to anti-HCV treatment among different ethnic populations deserves further examination.

One-Stage Reconstruction of the Penis with Free Skin Flap: Report of Three Cases

Three cases of penile defect of varying extent were reconstructed with free skin flaps from the forearm based on the radial artery. In two cases, part of the forearm flap was used to reconstruct the urethra, and the rest of the flap to reconstruct the corpus penis. A piece of autogenous cartilage was then inserted between the two layers. All procedures were completed in a one-stage operation. In the third case, a free skin graft was used for urethral reconstruction. Surgery in all three cases was successful, providing a penis of acceptable appearance as well as excellent urinary function.

Motorcycle emissions and fuel consumption in urban and rural driving conditions

This work reports sampling of motorcycle on-road driving cycles in actual urban and rural environments and the development of representative driving cycles using the principle of least total variance in individual regions. Based on the representative driving cycles in individual regions, emission factors for carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NO(x)=NO+NO(2)) and carbon dioxide (CO(2)), as well as fuel consumption, were determined using a chassis dynamometer. The measurement results show that the representative driving cycles are almost identical in the three largest cities in Taiwan, but they differ significantly from the rural driving cycle. Irrespective of driving conditions, emission factors differ insignificantly between the urban and rural regions at a 95% confidence level. However, the fuel consumption in urban centers is approximately 30% higher than in the rural regions, with driving conditions in the former usually poor compared to the latter. Two-stroke motorcycles generally have considerably higher HC emissions and quite lower NO(x) emissions than those of four-stroke motorcycles. Comparisons with other studies suggest that factors such as road characteristics, traffic volume, vehicle type, driving conditions and driver behavior may affect motorcycle emission levels in real traffic situations.

Molecular epidemiology of hepatitis B viral serotypes and genotypes in taiwan

Subtypes of hepatitis B virus (HBV) have specific geographic distributions and can serve as epidemiological markers. The relationship of HBV serotypes and genotypes in Taiwan and their correlation with the domiciles of origin in 122 patients with chronic HBV infection were investigated. The serotype of HBV was determined by comparing the surface gene encoding amino acids 22-148 of the major surface protein with published sequences. Genotyping of HBV was performed by polymerase chain reaction-restriction fragment length polymorphism. Serotype adw accounted for 70% (85/122) of all HBVs, with the remaining belonging to serotype adr. All adr HBVs were genotype C, regardless of the patient's domicile. Of the 85 adw HBVs, 69 (81%) were genotype B, 10 (12%) were genotype C, 5 (6%) were genotype F and only 1 (1%) was genotype A. In the 31 patients originating from mainland China, the prevalence of adr/genotype C was higher than in the 91 Taiwanese patients (15/31 vs. 22/91; p < 0.05). The distribution of the HBV serotypes and genotypes was not significantly different between 17 patients born in Taiwan (6 adw/genotype B, 2 adw/genotype C, 1 adw/genotype F and 8 adr/genotype C) and 14 patients born in mainland China (5 adw/genotype B, 2 adw/genotype C and 7 adr/genotype C). Our results indicate that in Taiwan, most HBVs of serotype adw are genotype B, and all HBVs of serotype adr are genotype C. Patients with origins in mainland China have a higher proportion of serotype adr/genotype C infection.

Molecular epidemiology of hepatitis B viral serotypes and genotypes in taiwan

Subtypes of hepatitis B virus (HBV) have specific geographic distributions and can serve as epidemiological markers. The relationship of HBV serotypes and genotypes in Taiwan and their correlation with the domiciles of origin in 122 patients with chronic HBV infection were investigated. The serotype of HBV was determined by comparing the surface gene encoding amino acids 22-148 of the major surface protein with published sequences. Genotyping of HBV was performed by polymerase chain reaction-restriction fragment length polymorphism. Serotype adw accounted for 70% (85/122) of all HBVs, with the remaining belonging to serotype adr. All adr HBVs were genotype C, regardless of the patient's domicile. Of the 85 adw HBVs, 69 (81%) were genotype B, 10 (12%) were genotype C, 5 (6%) were genotype F and only 1 (1%) was genotype A. In the 31 patients originating from mainland China, the prevalence of adr/genotype C was higher than in the 91 Taiwanese patients (15/31 vs. 22/91; p < 0.05). The distribution of the HBV serotypes and genotypes was not significantly different between 17 patients born in Taiwan (6 adw/genotype B, 2 adw/genotype C, 1 adw/genotype F and 8 adr/genotype C) and 14 patients born in mainland China (5 adw/genotype B, 2 adw/genotype C and 7 adr/genotype C). Our results indicate that in Taiwan, most HBVs of serotype adw are genotype B, and all HBVs of serotype adr are genotype C. Patients with origins in mainland China have a higher proportion of serotype adr/genotype C infection.

Probable reinfection with hepatitis C virus in a chronic hepatitis C patient with a sustained response to combination therapy

Superinfection with hepatitis C virus (HCV) in already chronically infected subjects has been documented. Whether a complete response to antiviral therapy is associated with protective immunity against reinfection with HCV remains unknown. We describe a patient who had a sustained biochemical and virologic response with loss of intrahepatic HCV RNA after a course of combination therapy using interferon plus ribavirin. Histopathologically, the chronic hepatitis was in remission on follow-up biopsy 6 months post-therapy. Unfortunately, 34 weeks post-therapy, a flare of hepatitis with reappearance of hepatitis C viremia was noted 2 months after he received injections from a non-licensed medical provider. Analysis of the core gene sequences showed a 95% homology between the HCV strains isolated before antiviral treatment and during the hepatitis flare. The data indicated that the hepatitis flare after a period of sustained response to combination therapy in this patient could have been caused by reinfection with homotypic HCV. Our observation indicates the lack of protective immunity against reinfection with HCV in patients with chronic hepatitis C, even after successful clearance of the virus. Therefore, reinforcing the education of these subjects to avoid HCV reinfection should be stressed.

Relation of Chlamydia pneumoniae infection in Taiwan to angiographically demonstrated coronary artery disease and to the presence of acute myocardial infarction or unstable angina pectoris

Reports of the association of Chlamydia pneumoniae (C. pneumoniae) infection with coronary artery disease (CAD) are scarce in the Oriental population. We therefore conducted a case-control study to explore this issue in Taiwan. There were 242 consecutive subjects (166 men and 76 women) who underwent cardiac catheterization at the National Taiwan University Hospital Cardiac Catheterization Laboratory. Patients with CAD (n = 156) had > or = 1 coronary artery lesion of > 50% diameter stenosis on angiography. Controls (n = 86) had no demonstrable CAD angiographically. Antibodies to C. pneumoniae were tested by using an enzyme-linked immunosorbent assay. The prevalence of antibodies to C. pneumoniae was as follows: immunoglobulin-G (IgG), 50% (122 of 242 patients); immunoglobulin-A (IgA), 72% (176 of 242 patients); and either IgG or IgA, 79% (192 of 242 patients ). The odds ratio (OR) for CAD with either IgG or IgA was 1.4 (95% confidence interval [CI] 0.7 to 2.7, p = 0.31). After adjusting for the known CAD risk factors, the OR decreased to 0.8 (95% CI 0.3 to 2.1, p = 0.60). The OR for unstable angina or acute myocardial infarction with the presence of either IgG or IgA was 0.5 (95% CI 0.2 to 1.1, p = 0.08) and 0.4 ( 95% CI 0.1 to 1.0, p = 0.049) after adjusting for other risk factors. These results suggest a high prevalence of C. pneumoniae infection in Taiwan. However, C. pneumoniae infection is not associated with angiographically documented CAD, and, in contrast, is a negative predictor for the development of acute coronary syndromes.

Acute exacerbations of chronic hepatitis B are rarely associated with superinfection of hepatitis B virus

There are 7 genotypes of hepatitis B virus (HBV). Whether superinfection of HBV carriers with different HBV genotypes occurs remains unknown. We therefore determined the HBV genotype and association between superinfection and acute exacerbation of disease in a cohort of 244 patients with chronic HBV infection who had elevated serum aminotransferase levels for at least 1 year. Within this group, 103 patients experienced acute exacerbation with an annual incidence of 13%, and 20 of the 103 patients had IgM antibody to hepatitis B core antigen (IgM anti-HBc). These 20 patients had a higher prevalence of genotype C infection (65%) than the remaining 83 anti-core IgM-negative patients (40%) who also had acute exacerbations (P <.05). Detailed analysis of HBV genotypes and sequences of the variable pre-S gene were determined in serial samples from 20 patients with IgM anti-HBc-positive acute exacerbations (group A), 20 patients with IgM anti-HBc-negative acute exacerbations (group B), and 20 patients without exacerbations (group C). Two (10%) of the group A patients had virologic evidence of HBV superinfection during acute exacerbation, one superinfected with heterotypic virus and the other with homotypic virus. The newly introduced virus disappeared after the exacerbation and the original virus resumed thereafter. The calculated prevalence of HBV superinfection in the hepatitis B carriers and those with acute exacerbations was 0.8% (2 of 244) and 1.9% (2 of 103), respectively. In conclusion, superinfection of HBV on hepatitis B carriers indeed occurs and may cause acute exacerbations, albeit at a low frequency even in hyperendemic areas of HBV infection.

Prolonged interferon treatment after combination interferon and ribavirin therapy in patients with chronic hepatitis C: a clinical trial of interferon relapsers and non-responders

BACKGROUND AND PURPOSE

For the retreatment of chronic hepatitis C patients relapsing after, or non-responsive to, previous interferon therapy, the efficacy of combination therapy with interferon alfa plus ribavirin is superior to interferon alone. The aim of this study was to determine whether prolonged interferon alfa treatment after 24-week combination therapy can further increase the efficacy of combination therapy.

METHODS

Nineteen interferon relapsers and 17 interferon non-responders were randomly assigned to receive either interferon alfa 5 million units (MU) thrice weekly plus oral ribavirin 1,200 mg daily for 24 weeks (regimen A) or interferon alfa 5 MU thrice weekly plus oral ribavirin 1,200 mg daily for 24 weeks followed by interferon alfa 3 MU thrice weekly for another 24 weeks (regimen B). Efficacy was assessed by normalization of serum aminotransferase concentrations and disappearance of serum hepatitis C virus (HCV) RNA at the end of treatment and at 24 weeks after stopping treatment.

RESULTS

Overall, 67% of relapsers receiving regimen A and 80% of those receiving regimen B had sustained virologic responses 24 weeks after stopping treatment. In contrast, 45% of non-responders receiving regimen A and 63% of those receiving regimen B had sustained responses. The sustained response was more common in relapsers with non-1b HCV genotypes. The sustained response rate to combination therapy was 50% or more in patients with genotype 1b infection.

CONCLUSIONS

Prolonged interferon treatment after combination therapy has a comparable efficacy to combination therapy alone for the retreatment of chronic hepatitis C patients relapsing after, or non-responsive to, previous interferon therapy.

Universal hepatitis B vaccination and the decreased mortality from fulminant hepatitis in infants in Taiwan

OBJECTIVES

To assess the annual mortality rate associated with fulminant hepatitis in infants before and after the mass immunization program that was launched in Taiwan in July 1984.

STUDY DESIGN

From the National Mortality Registry System, the data on the mortality from fulminant hepatitis in infants from 1975 to 1998 were retrieved. Poisson regression analysis was used to assess the difference in average mortality from fulminant hepatitis in infants before (1975-1984) and after (1985-1998) the implementation of the mass hepatitis B vaccination program.

RESULTS

The ratio of yearly mortality from 1975 to 1998 was 1.10 (P <.001), representing a progressive decrease in the number of the cases. The average mortality associated with fulminant hepatitis in infants from 1975 to 1984 and from 1985 to 1998 was 5.36 and 1.71 per 100,000 infants, respectively. The ratio of the average mortality in the period from 1985 to 1998 to that in the period from 1975 to 1984 was 0.32 (P <.001).

CONCLUSIONS

These data indicate that since the institution of a program of mass hepatitis B vaccination in Taiwan, the mortality associated with fulminant hepatitis in infants has declined significantly.

Lamivudine treatment for hepatitis B reactivation in HBsAg carriers after organ transplantation: a 4-year experience

BACKGROUND

Reactivation of hepatitis B after organ transplantation in hepatitis B surface antigen (HBsAg) carriers may be fatal. In this study, we reported our experience of lamivudine treatment in HBsAg carriers who had post-transplant reactivation of hepatitis B.

METHODS

The patients were 15 men and one woman. Nine received kidney transplants, six received heart transplants, and one received a lung transplant. They developed a reactivation of hepatitis B 1-101 months (median, 14 months) after transplantation. They received lamivudine 100 mg daily on a compassionate-use basis, and had regular follow ups. The median pretreatment total serum bilirubin level was 3.0 mg/dL, and the alanine aminotransferase level was 357 U/L. Four of the 16 patients were positive for HBeAg. The serum hepatitis B virus (HBV) DNA levels were > 3000 pg/mL in 13 (81%) patients. Three were coinfected with hepatitis C virus.

RESULTS

The overall survival rate was 75%. All four fatal cases had a pretreatment total serum bilirubin level of > or = 3 mg/dL. Serum HBV-DNA soon became undetectable in 12 survivors. Of the 12 survivors, after a median treatment period of 101 weeks, a lamivudine-resistant strain with variation in the YMDD motif of the HBV polymerase gene developed in three (25%). None had significant adverse reactions to lamivudine treatment.

CONCLUSIONS

These results indicated that lamivudine is effective in the treatment of post-transplant hepatitis B reactivation, including patients with dual chronic hepatitis B and C. Early recognition of HBV reactivation and prompt lamivudine treatment are important to prevent mortality.

Hepatitis B virus variants in patients receiving lamivudine treatment with breakthrough hepatitis evaluated by serial viral loads and full-length viral sequences

Both viral loads and genome variations have been implicated in the pathogenesis of acute exacerbation of chronic hepatitis B. Hepatitis B exacerbation in patients receiving lamivudine treatment represented a unique setting to clarify their importance. Three organ recipients with posttransplantation hepatitis B exacerbation and 3 patients with chronic hepatitis B were studied. All received lamivudine treatment and their alanine aminotransferase (ALT) levels and hepatitis B virus (HBV) loads were regularly followed. Full-length genomic sequences before and during lamivudine treatment were determined in patients who had breakthrough of serum HBV DNA or elevation of serum ALT. Breakthrough of serum HBV DNA occurred after 6 to 15 months of lamivudine treatment in all. A rapid increase of viral load accompanying the emergence of tyrosine-methionine-aspartate-aspartate (YMDD) variant was followed by hepatitis B exacerbation in each patient. The mean number of nucleotide and amino acid substitutions per genome pair was equivalent in immunosuppressed or immunocompetent patients (6.3 vs. 6.3 for nucleotide, P >.05; 6.0 vs. 6.7 for amino acid, P >.05). Changes of nucleotide and amino acid beyond the YMDD motif were distributed along the whole HBV genome but none occurred within the known B-cell epitopes and human leukocyte antigen class I- or II-restricted T-cell epitopes. Our results suggest that a resurgence of viral load rather than changes of the known immunogenic viral epitopes is more closely associated with the development of hepatitis B exacerbation after the emergence of YMDD variants in patients receiving lamivudine treatment.

Post-partum acute exacerbation of chronic hepatitis in a hepatitis C-carrier mother

Hepatitis C virus infection is a global health problem; however, the interaction between pregnancy and chronic hepatitis C remains controversial. A Taiwanese woman with chronic hepatitis C had an uncomplicated pregnancy and gave birth to a female baby through spontaneous vaginal delivery. The serum levels of alanine aminotransferase and hepatitis C virus (HCV) RNA were measured before pregnancy, in the first and third trimesters, 1 and 3 months after delivery, respectively. During her pregnancy, the serum aminotransferase levels became normalized, while the serum HCV-RNA levels declined significantly and consecutively with the lowest viral load in the third trimester. One month after delivery, she had an abrupt elevation of serum HCV-RNA level, paralleling a hepatitis flare with serum aminotransferase level more than 20-fold the upper normal limit. The serum HCV-RNA levels declined thereafter, and serum aminotransferase levels became normalized 3 months postdelivery. She was infected with HCV genotype 1a throughout the entire follow-up period, and other causes of hepatitis flare were excluded. In conclusion, post-partum acute exacerbation of chronic hepatitis may occur in HCV-carrier mothers, and an abrupt elevation of serum HCV-RNA level may be associated with the acute exacerbation.

Efficacy of consensus interferon in the treatment of chronic hepatitis C

BACKGROUND AND AIMS

Consensus interferon (CIFN) is a newly developed type I interferon. The aim of this study was to investigate the safety and efficacy of CIFN in the treatment of patients with chronic hepatitis C and to determine the predictors for sustained response.

METHODS

Patients were randomized to receive 3 micrograms or 9 micrograms CIFN three times a week for 24 weeks, followed by 24 weeks of observation. Efficacy was assessed by normalization of serum transaminase levels and disappearance of serum hepatitis C virus (HCV)-RNA at the end of treatment and at 24 weeks after stopping treatment. Histologic response was defined as a decrease of at least two points in the Knodell necroinflammatory score at week 48 and was compared with baseline.

RESULTS

There were no serious adverse effects related to CIFN therapy. Overall, 44% of patients receiving 3 micrograms and 48% of patients receiving 9 micrograms had normalization of serum transaminase levels and disappearance of HCV viremia at the end of treatment. At 24 weeks after stopping treatment, 16% of patients in receiving 9 micrograms and 12% of patients receiving 3 micrograms had sustained responses. The histologic responses in patients receiving 9 micrograms and those receiving 3 micrograms were 60% and 36%, respectively. The necroinflammatory score was significantly reduced from baseline to week 48 in both groups. In addition, bodyweight < 60 kg and pretreatment serum HCV-RNA level < 0.5 MEq/mL can serve as predictors for sustained response to CIFN treatment.

CONCLUSIONS

These findings suggest that 9 micrograms CIFN is safe and effective in the treatment of patients with chronic hepatitis C.

Hepatitis B genotypes and the response to interferon therapy

BACKGROUND/AIMS

Possible pathogenic differences among hepatitis B virus (HBV) genotypes have been observed; however, the response to interferon therapy among HBV genotypes remains unknown. We therefore analyzed the efficacy of interferon alfa in the treatment of chronic hepatitis B patients with different HBV genotypes.

METHODS

Fifty-eight genotype B or C infected chronic hepatitis B patients who had been treated with interferon alfa-2b were retrospectively studied. The response to interferon was defined as normalization of serum aminotransferase level, loss of hepatitis B e antigen and HBV DNA 48 weeks post-treatment.

RESULTS

Baseline data of both groups of patients were comparable; however, genotype C patients had a higher serum aminotransferase level and a higher frequency of core promoter mutation. The response rate was 41% and 15% in genotype B and C patients, respectively (p=0.045). In those with higher serum aminotransferase levels, the response rate was 50% and 17%, respectively (p=0.025). Additionally, younger age and genotype B infection may predict a better response to interferon alfa.

CONCLUSIONS

HBV genotype C, compared to genotype B, is associated with a higher frequency of core promoter mutation, and a lower response rate to interferon alfa therapy.

Hepatitis C virus load during pregnancy and puerperium

OBJECTIVE

To assess whether pregnancy and delivery influence serum levels of hepatitis C virus (HCV) in carrier mothers.

DESIGN

A prospective study.

SETTING

University department of obstetrics and gynaecology.

PARTICIPANTS

Ten pregnant HCV carriers (group A) and 8 nonpregnant HCV carriers (group B).

METHODS

Serum samples were collected for group A at first and third trimesters, delivery, postpartum 1, 3, 6, 9 and 12 months, and at every three months for 1 year for group B.

MAIN OUTCOME MEASURES

Each serum sample was tested for serum alanine aminotransferase (ALT), anti-HCV titre and HCV-cDNA concentration by a competitive polymerase chain reaction (PCR) with a sensitivity of 250 copies/mL serum.

RESULTS

In group A, the HCV levels remained unremarkably changed during pregnancy and delivery. However, all women had decreased HCV levels 1 and 3 months after delivery. Two women had undetectable serum HCV level postpartum and thereafter. Serum ALT values in 3 women were sporadically elevated, but did not correlate with decreased serum HCV levels. Anti-HCV titres remained unchanged during the study period. In two women from group B, the serum HCV levels were undetectable during follow up. Other 6 women showed fluctuations in the serum HCV levels but all were above 250 copies/mL. Serum ALT values were normal and anti-HCV titres remained stationary in all 8 nonpregnant carriers.

CONCLUSION

Serum HCV levels are decreased 1 and 3 months after delivery. This fact might suggest that puerperium is an optimal time for antiviral therapy in HCV carrier mothers.

Interspousal transmission of TT virus: low efficiency and lack of apparent risk factors

BACKGROUND

The TT virus (TTV) is a newly identified human DNA virus and little is known about its non-parenteral transmission. The aim of the present study was to explore the prevalence of TTV infection in spouses of index cases and the related risk factors.

METHODS

Serum TTV-DNA was studied in spouses of 41 subjects with TT viremia. For couples in which both husband and wife had TT viremia, nucleotide sequences of the open reading frame-1 region were analyzed by phylogenetic tree constructions.

RESULTS

Three (7%) of 41 spouses were positive for TTV-DNA. No differences were noted between index patients with seropositive spouses and those without seropositive spouses with regard to clinical characteristics, including parenteral risk factors and exposure duration. Nucleotide sequence comparison and phylogenetic tree analysis of the viral genome in three TTV-infected couples revealed the isolates to be closely related in two, with a homology of 97 and 98%, respectively.

CONCLUSIONS

These results suggest that interspousal transmission of TTV does occur; however,the efficiency of transmission is low compared with hepatitis C virus and GB virus-C. There are no apparent risk factors for transmission between spouses and further studies are needed to clarify other modes of non-parenteral transmission.

Effectiveness of second- and third-generation immunoassays for the detection of hepatitis C virus infection in pregnant women

OBJECTIVE

To compare the sensitivity and specificity of a third-generation anti-hepatitis C virus (anti-HCV) assay (HCV 3.0) with second-generation one (HCV 2.0), and correlate with HCV-RNA positivity by reverse-transcription polymerase chain reaction (RT-PCR).

METHODS

We enrolled 197 pregnant women without screening for alanine aminotransferase (ALT) (Group A) and 324 pregnant women with elevated ALT activity (> 45 IU/l) (Group B). Each serum sample was tested by second- and third-generation tests, and anti-HCV titer was determined by serial dilutions. Anti-HCV-positive samples were subjected to HCV-RNA assays.

RESULTS

Three (1.5%) and 4 (2.0%) of the 197 group A subjects were anti-HCV-positive by the second- and third-generation methods, respectively, while 17 (5.3%) and 21 (6.5%) of group B were positive, respectively. Three (1.5%) in group A and 8 (2.5%) in group B were HCV 2.0-negative, but positive for HCV 3.0. The sensitivity, specificity, positive and negative predictive values of HCV 2.0 and HVC 3.0 for positive HCV-RNA in both groups were 67 vs 100%, 30 vs 75%, 67 vs 92%, and 30 vs 100%, respectively. The anti-HCV-positive samples with optical density (O.D.) < 1.0 either by second- or third-generation test were negative for HCV-RNA, whereas samples with O.D. > or = 1.0 were all HCV-RNA-positive.

CONCLUSIONS

The performance of HCV 3.0 is better than that of HCV 2.0, and anti-HCV-positive samples with O.D. < 1.0 are negative for HCV-RNA.

Incidence and clinical presentation of posttransfusion TT virus infection in prospectively followed transfusion recipients: emphasis on its relevance to hepatitis

BACKGROUND

A novel transfusion-transmissible human DNA virus, TT virus (TTV), has been discovered recently. An attempt was made to determine the incidence and clinical outcome of TTV infection in recipients of blood transfusion.

STUDY DESIGN AND METHODS

Serial serum samples collected as part of a prospective study of posttransfusion hepatitis were examined for TTV DNA by a nested PCR assay.

RESULTS

Among 150 adults undergoing cardiac surgery, posttransfusion specimens from 59 individuals were positive for TTV DNA. Pretransfusion sera were found to be positive in 13 of these individuals. Therefore, 46 (33.6%) of the 137 previously uninfected patients developed new TTV viremia after transfusion. Among the 46 patients, 3 were coinfected with HCV, 5 were coinfected with HGV, and 38 were infected with TTV alone. No apparent symptoms or signs were noted in the 38 patients infected by TTV alone or the 5 infected with HGV plus TTV. The average peak serum ALT activity was 31 IU per L, with persistently normal levels in 34 of the 38 patients with TTV infection alone. In 8 other patients who subsequently developed well-documented non-A-G hepatitis, 3 were positive for TTV (3/8 vs. 46/137, p = 0.8). In 12 patients followed for more than 1 year, TTV viremia persisted in every case.

CONCLUSION

In this population, TTV is transmitted by transfusion to approximately 30 percent of patients who undergo cardiac surgery. Most of the infections appear to become persistent. Despite the high prevalence rate, TTV does not appear to cause hepatitis on its own.

Transmission of hepatitis C virus in Asia: past and present perspectives

Hepatitis C virus (HCV) infection is a major public health problem. The epidemiology of HCV infection in different parts of Asia is similar, with an average seroprevalence of hepatitis C antibody (anti-HCV) less than 2.5% in healthy adults. The infection is rarely seen in children. The major routes of HCV transmission in Asia during the past few decades have been through administration of therapeutic blood products and injecting drug use, similar to the pattern observed in other parts of the world. However, obvious parenteral routes of transmission only account for 30-60% of anti-HCV-positive cases, depending on the geographic area. Other inapparent parenteral or per-mucosal exposures, including medical intervention, tattooing, acupuncture, vertical and sexual transmission, accidental needlestick and household contact, are also possible routes of HCV transmission. Although screening of blood donors for anti-HCV and improvements in infection control have significantly decreased the exposure to HCV, it is believed that HCV is still spreading in some areas of Asia because of the lack of routine screening of donated blood, injecting drug usage, traditional medicine practices or medical treatment under suboptimal hygienic conditions that involve blood contamination, and tattooing. Accordingly, until effective and safe immunoprophylaxis is available, interruption of transmission routes, such as implementation of blood donor screening for anti-HCV, adequate sterilization of surgical instruments or the use of disposable medical instruments, especially needles and syringes, and avoidance of sharing personal grooming aids remains the mainstay to prevent HCV infection in Asia today.

TT virus infection in patients with chronic hepatitis B or C: influence on clinical, histological and virological features

Concomitant infection with TT virus and hepatitis B virus (HBV) or hepatitis C virus (HCV) is common. However, the effect of TTV infection on chronic hepatitis B or C is unknown. The prevalence of TTV infection, the effect of TTV infection on the clinical, histological and virological features of patients with chronic hepatitis B or C, and the influence of TTV infection on the HCV response to interferon alfa therapy were studied. A total of 100 asymptomatic hepatitis B surface antigen carriers, 220 patients with HBV-related chronic liver diseases, and 110 patients with chronic hepatitis C treated with interferon alfa (3 million units subcutaneously three times a week for 24 weeks) were enrolled. Serum HCV RNA and serum TTV DNA were detected by the polymerase chain reaction (PCR). Serum HBV DNA and serum HCV RNA level were quantified by branched DNA assays. Infection with TTV was detected in 21.5% of HBV carriers and 37% of HCV carriers. TTV infection had little effect on the clinicopathological course of chronic HBV infection. In chronic hepatitis C, clinical features, histological severity, serum HCV RNA levels, and the response to interferon alfa therapy did not differ between those with and without TTV infection. The loss of serum TTV DNA did not correlate with the biochemical response as did in the loss of serum HCV RNA. In conclusion, TTV infection is found frequently in patients with chronic hepatitis B or C in Taiwan; however, coinfection with TTV does not affect the clinicopathological course of chronic hepatitis B or C and the response to interferon alfa therapy.

Low incidence of hepatitis C virus transmission between spouses: a prospective study

BACKGROUND

Interspousal transmission of hepatitis C virus (HCV) has been documented; however, the annual risk of interspousal transmission remains unclear.

METHODS

A long-term prospective study to define the risk of interspousal transmission of HCV was conducted. One hundred and twelve index patients with chronic hepatitis C and their anti-HCV seronegative spouses were enrolled.

RESULTS

The mean follow-up period was 45.9 months. Antibodies to HCV (anti-HCV) and HCV-RNA were tested for in each seronegative spouse every year. Seroconversion of anti-HCV occurred in only one spouse, 2 years after enrollment, with a concomitant acute hepatitis. This subject and his spouse were infected with HCV genotype 1b. Nucleotide sequence comparison of the hypervariable region of their HCV genomes showed a homology of 98%. Further phylogenetic analysis suggested that they had virtually the same isolate. Accordingly, the annual risk of interspousal transmission of HCV infection was 0.23% per year.

CONCLUSIONS

These findings suggest a low incidence of interspousal transmission of HCV; however, the risk may be cumulative and such couples should be educated to avoid HCV infection from their spouses.

TT virus infection in patients with chronic hepatitis B or C: influence on clinical, histological and virological features

Concomitant infection with TT virus and hepatitis B virus (HBV) or hepatitis C virus (HCV) is common. However, the effect of TTV infection on chronic hepatitis B or C is unknown. The prevalence of TTV infection, the effect of TTV infection on the clinical, histological and virological features of patients with chronic hepatitis B or C, and the influence of TTV infection on the HCV response to interferon alfa therapy were studied. A total of 100 asymptomatic hepatitis B surface antigen carriers, 220 patients with HBV-related chronic liver diseases, and 110 patients with chronic hepatitis C treated with interferon alfa (3 million units subcutaneously three times a week for 24 weeks) were enrolled. Serum HCV RNA and serum TTV DNA were detected by the polymerase chain reaction (PCR). Serum HBV DNA and serum HCV RNA level were quantified by branched DNA assays. Infection with TTV was detected in 21.5% of HBV carriers and 37% of HCV carriers. TTV infection had little effect on the clinicopathological course of chronic HBV infection. In chronic hepatitis C, clinical features, histological severity, serum HCV RNA levels, and the response to interferon alfa therapy did not differ between those with and without TTV infection. The loss of serum TTV DNA did not correlate with the biochemical response as did in the loss of serum HCV RNA. In conclusion, TTV infection is found frequently in patients with chronic hepatitis B or C in Taiwan; however, coinfection with TTV does not affect the clinicopathological course of chronic hepatitis B or C and the response to interferon alfa therapy.

Hepatitis B genotypes correlate with clinical outcomes in patients with chronic hepatitis B

BACKGROUND & AIMS

Six genotypes (A-F) of hepatitis B virus (HBV) have been identified; however, the genotype-related differences in the pathogenicity of HBV remain unknown. Therefore, we investigated the prevalence of HBV genotypes in Taiwan and the association between distinct genotypes and severity of liver disease in a cross-sectional study.

METHODS

Using a molecular method, HBV genotypes were determined in 100 asymptomatic carriers and in 170 patients with histologically verified chronic liver disease and hepatocellular carcinoma (HCC).

RESULTS

All genotypes except genotype E were identified in Taiwan, and genotypes B and C were predominant. Genotype C was prevalent in patients with cirrhosis and in those with HCC who were older than 50 years compared with age-matched asymptomatic carriers (60% vs. 23%, P < 0.001, and 41% vs. 15%, P = 0.005, respectively). Genotype B was significantly more common in patients with HCC aged less than 50 years compared with age-matched asymptomatic carriers (80% vs. 52%, P = 0.03). This predominance was more marked in younger patients with HCC (90% in those aged </=35 years), most of whom did not have cirrhosis.

CONCLUSIONS

Our data suggest that HBV genotype C is associated with more severe liver disease and genotype B may be associated with the development of HCC in young Taiwanese. However, additional large-scale longitudinal studies are needed to confirm the relationship of HBV genotypes to liver disease severity and clinical outcomes.

Liver and peripheral blood mononuclear cells are not major sites for GB virus-C/hepatitis G virus replication

The pathogenesis and replication sites of GB virus-C/hepatitis G virus (GBV-C/HGV) in humans remain unclear. The presence of GBV-C/HGV and hepatitis C virus (HCV) RNA sequences in matched serum, peripheral blood mononuclear cells (PBMC) and liver samples in 10 patients with GBV-C/HGV infection, 8 of whom were coinfected with HCV was explored. Positive- and negative-strand GBV-C/HGV and HCV RNA were detected by strand-specific reverse-transcription polymerase chain reaction (RT-PCR), and virus titers were quantified by competitive PCRs. Positive-strand GBV-C/HGV RNA was detected in 7 of 10 PBMC samples of the patients with serum GBV-C/HGV RNA, but negative-strand GBV-C/HGV RNA was not found in these cells. Positive-strand GBV-C/HGV RNA was found in 9 liver samples, and 2 (22%) of them also had negative strand. In contrast, negative-strand HCV RNA was frequently found in PBMC and liver samples. A positive correlation between the titer of viral RNA in liver tissue and that in serum sample was demonstrated in HCV infection, but not in GBV-C/HGV infection. These findings suggest that liver and PBMC are not the major replication sites for GBV-C/HGV and that GBV-C/HGV is not a primary hepatotropic virus.

Prevalence and implication of TT virus infection: minimal role in patients with non-A-E hepatitis in Taiwan

TT virus (TTV) is a newly identified human DNA virus and little is known about its clinical significance. The aim of the study was to explore the prevalence of TTV infection in different risk populations and in patients with various liver diseases. Viral DNA was studied in 190 high-risk individuals, 97 household contacts, 52 patients with acute hepatitis A, 32 patients with non-A-E hepatitis including 13 fulminant hepatitis, 200 asymptomatic hepatitis B surface antigen (HBsAg) carriers, 100 patients with chronic hepatitis C, and 100 healthy adults. TTV infection was more frequent in high-risk groups (26-70%), patients with acute or fulminant non-A-E hepatitis (42-45%), and hepatitis C carriers (36%) than in healthy adults (10%) and hepatitis B carriers (15%). However, most of subjects with TTV infection alone had no or only mild hepatitis, and the same rate of TTV DNA in pre-hepatitis serum samples and constant serum TTV titers during hepatitis episodes were observed in two patients with acute non-A-E hepatitis. Phylogenetic analysis of the Taiwanese TTV isolates showed genetic heterogeneity and most (68%) isolates were TTV type 1. No particular strain was found to be associated with fulminant non-A-E hepatitis.

Molecular methods of measurement of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus infection: implications for occupational health practice

Over the past decade, several molecular techniques for the detection of human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) have been developed that have implications for occupational health practice. This review describes the techniques used for qualitative and quantitative detection of the viral genome, and briefly explains nucleic acid sequencing and analysis of phylogenetic trees. The review also discusses the current and potential uses of these techniques in investigations of transmission of bloodborne viruses by patient to worker and worker to patient, in the management of occupational exposure to blood, in research, and in the development of guidance and policy on infected healthcare workers who perform procedures prone to exposure.

Prevalence and implication of TT virus infection: minimal role in patients with non-A-E hepatitis in Taiwan

TT virus (TTV) is a newly identified human DNA virus and little is known about its clinical significance. The aim of the study was to explore the prevalence of TTV infection in different risk populations and in patients with various liver diseases. Viral DNA was studied in 190 high-risk individuals, 97 household contacts, 52 patients with acute hepatitis A, 32 patients with non-A-E hepatitis including 13 fulminant hepatitis, 200 asymptomatic hepatitis B surface antigen (HBsAg) carriers, 100 patients with chronic hepatitis C, and 100 healthy adults. TTV infection was more frequent in high-risk groups (26-70%), patients with acute or fulminant non-A-E hepatitis (42-45%), and hepatitis C carriers (36%) than in healthy adults (10%) and hepatitis B carriers (15%). However, most of subjects with TTV infection alone had no or only mild hepatitis, and the same rate of TTV DNA in pre-hepatitis serum samples and constant serum TTV titers during hepatitis episodes were observed in two patients with acute non-A-E hepatitis. Phylogenetic analysis of the Taiwanese TTV isolates showed genetic heterogeneity and most (68%) isolates were TTV type 1. No particular strain was found to be associated with fulminant non-A-E hepatitis.

Antiandrogen hepatotoxicity in patients with chronic viral hepatitis

OBJECTIVE

To assess whether patients with chronic viral hepatitis are at an increased risk for antiandrogen hepatotoxicity.

METHODS

We retrospectively reviewed 121 prostate cancer patients who received long-term antiandrogen, either flutamide (n = 56) or cyproterone acetate (n = 65), and had normal pretreatment serum alanine aminotransferase (ALT) levels. Serological markers of hepatitis B and C viruses (HBV and HCV) were checked in 42 of the 121 patients.

RESULTS

Twenty-two (18%) of the 121 patients had ALT elevations during antiandrogen therapy. Thirteen (59%) of the 22 patients were positive for either one of the two viral markers, including 7 for HBV, 4 for HCV, and 2 for both. This percentage was higher than the combined prevalence rate of positivity for HBV and/or HCV markers (<20%) in Taiwan. There was no significant differences in the percentage of positive makers among the two antiandrogen groups (p = 0.092). Although a higher incidence of hepatotoxicity was noted in the flutamide (13/56, 23%) than in the cyproterone acetate group (9/65, 14%), there were no significant differences between the two groups (p = 0.27). The time period between initiation of antiandrogen and first ALT elevation varied significantly (from 4 to 1,398 days with a median of 151 days). Half of the 14 HBV carriers and all of the 6 patients with anti-HCV developed antiandrogen hepatotoxicity.

CONCLUSION

Our limited data suggested that patients with chronic viral hepatitis probably are at a higher risk of developing antiandrogen hepatotoxicity. Close monitoring of liver functions in patients with chronic viral hepatitis is advised if antiandrogen therapy is necessary. However, a large-scale study is necessary for a definitive conclusion.

GB virus C infection in hemodialysis patients: molecular evidence for nosocomial transmission

Studies of the prevalence and clinical relevance of GB virus C (GBV-C) infection in 328 hemodialysis (HD) patients were done, and the possibility of nosocomial GBV-C transmission was explored by molecular epidemiology methods. For GBV-C viremic patients in a given HD unit, nucleotide sequences of the envelope region were analyzed by phylogenetic tree constructions. Of 328 HD patients, active hepatitis B virus, hepatitis C virus (HCV), and GBV-C infection were detected in 13%, 23%, and 17%, respectively. Except for a higher frequency of HCV coinfection, the demographic and clinical characteristics of patients with and without GBV-C infection were comparable. In contrast, patients with isolated HCV infection had significantly higher serum transaminase levels, longer time on HD, and more blood transfusions. Phylogenetic analysis showed several distinct clusters of closely related GBV-C isolates from one HD unit, suggesting the possibility of nosocomial transmission. These results suggest that GBV-C plays a minimal role in causing hepatitis in Taiwanese HD patients and in nosocomial transmission.

Comparison of two methods for quantification of hepatitis B viral DNA

BACKGROUND

Quantitation of serum hepatitis B virus (HBV) DNA has proven useful in assisting with patient management and treatment and several commercially available assays have been developed to quantify serum HBV-DNA levels.

METHODS

The performance of the cross-linking assay and the branched-DNA signal amplification (bDNA) assay for the quantitative measurement of HBV-DNA was studied in 99 hepatitis B surface antigen-positive and viraemic patients.

RESULTS

Of these samples, 82 (83%) were positive for HBV-DNA by both assays and four (4%) were below the cut-off for both assays. Of the remaining 13 samples, 10 contained measurable levels of HBV-DNA by the cross-linking assay alone and three other samples contained measurable levels of HBV-DNA by the bDNA assay alone. The sensitivity gain of the cross-linking assay relative to bDNA assay in this study population was 10/92 (11%). In addition, a linear regression analysis showed that the HBV-DNA levels obtained from both assays was significantly correlated (gamma=0.974, P< 0.0001).

CONCLUSIONS

These findings suggest that the recently developed cross-linking assay is more sensitive than the bDNA assay for the quantitative determination of HBV-DNA.

Minimal role of GB virus-C/hepatitis G virus in fulminant and subfulminant hepatitis in Taiwan

BACKGROUND

The role of GB virus-C/hepatitis G virus (GBV-C/HGV) in fulminant hepatitis (FH) and subfulminant hepatitis (SFH) remains unclear.

METHODS

Thirty-two FH or SFH patients, with adequate clinical information and serum specimens, were studied. Serum samples were tested for hepatitis markers and genomes of hepatitis A-E viruses, as well as GBV-C/HGV.

RESULTS

Of the cases of FH/SFH studied, one (3%) was caused by anti-tuberculosis agents, 26 (81%) had hepatotropic virus infection, and five (16%) had no identifiable cause. Of the 26 patients with hepatotropic virus infection, five had acute hepatitis B infection (one with acute hepatitis D virus (HDV) co-infection), one had acute hepatitis C infection, 16 were hepatitis B surface antigen carriers with reactivation or superimposed by unidentified agent(s) (two had triple virus infections), three were hepatitis B carriers with HDV superinfection, and one had GBV-C/HGV infection in addition to exposure to halothane. GBV-C/HGV-RNA was detected in only three of 32 patients (9%) and all had a history of blood transfusion or co-existing causative factors. Of the 26 patients with hepatotropic virus infection, 18 were tested for antibodies against GBV-C/HGV envelope protein and seven were reactive, suggesting past infection.

CONCLUSIONS

The role of GBV-C/HGV in causing FH and SFH is minimal in Taiwan and HBV infection remains the major aetiology. These findings also suggest the existence of as yet unrecognized agents, responsible for such catastrophic illnesses.

Efficacy of ribavirin plus interferon alpha on viraemia of GB virus-C/hepatitis G virus: comparison with interferon alpha alone

We investigated the efficacy of ribavirin plus interferon (IFN) alpha on GB virus-C (GBV-C)/hepatitis G virus (HGV) viraemia and compared it with that of interferon alpha alone in patients coinfected with hepatitis C virus (HCV) and GBV-C/HGV. Serum HCV and GBV-C/HGV-RNA were studied in eight patients with HCV and GBV-C/HGV coinfection, five received IFN alpha and three received oral ribavirin plus IFN alpha. Mean serum GBV-C/HGV titre at the end of therapy was significantly lower than the titre just before therapy and patients with lower pretreatment titre had a better sustained response rate. Sustained virological response of GBV-C/HGV to IFN alpha alone and ribavirin plus IFN alpha at the end of follow up was observed in one each, respectively. Thus, GBV-C/HGV in patients with HCV and GBV-C/HGV coinfection does respond to IFN alpha and ribavirin plus IFN alpha may not induce a higher sustained response.