bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hepatitis B virus DNA levels and outcomes in chronic hepatitis B # †
Authors: Chen Chien-Jen , Yang Hwai-I , Iloeje Uchenna H. 
Published: July 2010

Abstract
Serum hepatitis B virus (HBV) DNA levels can fluctuate markedly during the course of chronic HBV infection. Both case-control and cohort studies have shown a significant, dose-response association between serum HBV DNA levels measured at the time of initial evaluation and the subsequent risk of cirrhosis. A similar direct relationship has been shown for the risk of hepatocellular carcinoma (HCC) in cross-sectional, case-control, and cohort studies. Interventional studies have shown a strong correlation between the indices of disease activity seen on liver biopsy and levels of serum HBV DNA. These studies have also shown that reduction in HBV DNA levels correlate strongly with improvements in liver histology. For patients with HCC, prognosis (including risk of death, metastasis, and recurrence following surgery) is worse with higher serum HBV DNA levels. The preponderance of the evidence in the published literature demonstrates that serum HBV DNA level is an important and independent risk factor for disease progression in chronic hepatitis B. The relative importance of serial HBV DNA measurements, the loss of hepatitis B e and surface antigens, as well as the emergence of HBV mutants in the progression of chronic hepatitis B, especially in young patients, is an important need for future research. (Hepatology 2009;49:S72–S84.)
The natural history of chronic hepatitis B virus infection #
Authors: McMahon Brian J. 
Published: July 2010

Abstract
Chronic hepatitis B virus (HBV) infection has a complicated course. Three phases are identified: an immune tolerant phase with high HBV DNA and normal alanine aminotransferase (ALT) levels associated with minimal liver disease; an immune active phase with high HBV DNA and elevated ALT levels with active liver inflammation; and an inactive phase with HBV DNA levels < 2000 IU/mL and normal ALT levels with minimal inflammation and fibrosis on liver biopsy. Affected persons can move progressively from one phase to the next and may revert backward. The primary adverse outcomes of chronic HBV infection are hepatocellular carcinoma (HCC) and cirrhosis. Published natural history studies were reviewed and ranked by the strength of evidence regarding the study design. Factors with the highest evidence of risk for development of HCC or cirrhosis from population-based prospective cohort studies include male sex, family history of HCC, HBV DNA level above 2000 IU/mL in persons above age 40, HBV genotypes C and F, and basal core promoter mutation. Those with the next highest level of evidence include aflatoxin exposure, and heavy alcohol and tobacco use. Improved methods to identify persons at highest risk of developing HCC or cirrhosis are needed to allow intervention earlier with antiviral therapy in appropriate patients. Future studies should include prospective follow-up of established population-based cohorts as well as new cohorts recruited from multiple centers stratified by HBV genotypes/subgenotypes and clinical phase to determine the incidence of the various HBV phases, HCC, and cirrhosis. Also, nested case-control studies assessing immunological and host genetic factors among persons with active and inactive disease phases, HCC, and cirrhosis could be conducted using these types of cohorts. (Hepatology 2009;49:S45–S55.)
Monitoring during and after antiviral therapy for hepatitis B #
Authors: Andersson Karin L. , Chung Raymond T. 
Published: July 2010

Abstract
Recent studies suggest that long-term suppression of viral replication is critical to reducing the complications of chronic hepatitis B virus (HBV) infection. Monitoring for continued virological response during and after treatment is essential because current treatment options have limited success in achieving durable endpoints, and antiviral resistance may emerge during long-term therapy. Methods of monitoring treatment response include tests for serum aminotransferase levels, HBV DNA level, hepatitis B e antigen (HBeAg) and antibody (anti-HBe), hepatitis B surface antigen (HBsAg) or antibody (anti-HBs), and liver histology. Virological suppression and loss of HBeAg or HBsAg with or without seroconversion play a prominent role in decision-making regarding the success and duration of antiviral therapy. Guidelines recommend that testing for serum markers be repeated every 12-24 weeks during antiviral therapy and every 6-12 months afterward. Recent data also suggest that serum HBV DNA levels should be assessed at weeks 12 and 24 of therapy, because early viral response may predict the likelihood of sustained response and antiviral resistance. The use of serum HBV DNA levels for this purpose requires an assay with a wide range of quantification, such as real-time polymerase chain reaction assays, which have a 7-8 log10 dynamic range. Newer, investigational methods for monitoring treatment response include quantitative measurement of HBsAg, HBeAg, and intrahepatic covalently closed circular DNA. Conclusions: Better methods for defining durable treatment endpoints are needed. Other areas requiring further research include the optimal treatment duration and the establishment of the optimal use of early viral kinetics for decision-making during antiviral therapy. (Hepatology 2009;49:S166–S173.)
Antiviral resistance and hepatitis B therapy #
Authors: Ghany Marc G. , Doo Edward C. 
Published: July 2010

Abstract
The management of chronic hepatitis B currently rests with long-term therapy using oral nucleoside analogs. The major limitation of long-term therapy is antiviral resistance. Antiviral resistance is due to the high rate of mutations that can occur during hepatitis B virus (HBV) replication and the selection of these mutants due to a replication advantage in the presence of the antiviral agent. Indeed, high rates of antiviral resistance have been found with long-term use of lamivudine, in up to 76% of patients treated for 5 years or more. Rates of antiviral resistance are lower with adefovir therapy, ˜30% at 5 years. Newer more potent nucleoside analogs (tenofovir and entecavir) have proven to have much lower rates of antiviral resistance (<1% after 2 years in treatment-naïve subjects), but the long-term rates of resistance have yet to be fully defined. The appearance of these viral mutations (genotypic resistance) is usually followed by rises in HBV DNA levels (virological breakthrough) and then by rises in serum aminotransferase levels (biochemical breakthrough). The appearance of antiviral resistance can be accompanied by a transient but occasionally severe exacerbation of the underlying liver disease which in some instances has led to acute liver failure. Combinations of nucleoside analogs may offer an approach to preventing antiviral resistance, but the efficacy and safety of this approach have yet to be shown. A future research priority is to identify new agents active against HBV that target different steps in the viral life-cycle and might provide effective means to circumvent the antiviral resistance of nucleoside analogs. (Hepatology 2009;49:S174–S184.)
Benefits and risks of nucleoside analog therapy for hepatitis B #
Authors: Dienstag Jules L. 
Published: July 2010

Abstract
Five oral agents have been approved for the treatment of chronic hepatitis B, ranging in virological potency, clinical efficacy, barrier to resistance, and side-effect profile. The degree of histological, biochemical, and serological improvement with therapy generally corresponds to the degree of suppression of serum hepatitis B virus (HBV) DNA achieved with therapy. Conversely, for agents with a low barrier to resistance, the profundity of HBV DNA suppression in individual patients correlates inversely with the likelihood of resistance. The durability of hepatitis B e antigen (HBeAg) responses after a consolidation period of an additional 6–12 months of therapy is ˜80% in western populations, lower in Asian populations. Loss of hepatitis B surface antigen (HBsAg) during a year of oral-agent therapy is limited, except with the most potent agents, but extending therapy for a second year and beyond can yield frequencies of HBsAg responses close to those reported in trials of interferon-based therapy. The oral agents are approved for 1–2 years of therapy, but treatment is continued indefinitely in the majority of patients (except for the ˜20% of patients who are HBeAg-reactive who achieve a durable HBeAg response). HBeAg responses and virological/biochemical benefit continue to be maintained and to increase with continued therapy beyond the first year. Data continue to accumulate supporting the link between long-term HBV DNA suppression and reduction in hepatic fibrosis, hepatic decompensation, and liver-related mortality. All the benefits of a single year of injectable peginterferon therapy can be achieved with the newer, low-resistance oral agents continued beyond the first year, without interferon side effects. Future studies are needed to develop drug regimens that are even more effective in achieving clinical endpoints, that are not hampered by resistance, and that are more confined in treatment duration but are more durable. (Hepatology 2009;49:S112–S121.)
Clinical outcomes in adults with chronic hepatitis B in association with patient and viral characteristics: A systematic review of evidence # †
Authors: Taylor Brent C. , Yuan Jian-Min , Shamliyan Tatyana A. , Shaukat Aasma , Kane Robert L. , Wilt Timothy J. 
Published: July 2010

Abstract
We systematically reviewed the literature on the extent to which population characteristics or clinical features predict groups of individuals likely to develop advanced liver disease or die from chronic infection with hepatitis B virus (HBV). We searched Medline to include studies with reported cirrhosis, liver failure, liver cancer, or death outcomes after at least 1 year of follow-up from the measurement of predictive factors (age, age at infection, geographic location, race/ethnicity, sex, positive family history, presence of coinfections, HBV viral level, change in hepatitis B e antigen [HBeAg] status, genotype, HBV mutations, nonalcoholic fatty liver disease, alcohol consumption, liver enzymes, and liver biopsy finding). Evidence from 41 included articles suggested that cirrhosis, higher HBV viral level, and male sex were consistently associated with significantly increased risk of death and liver cancer. Evidence about the role of HBV genotype, HBeAg status, age and duration of infection, coinfections with hepatitis C virus, human immunodeficiency virus, hepatitis delta virus, and alanine aminotransferase levels were limited and inconsistent, but were deemed promising to identify patients at higher risk of clinical outcomes. Adults with chronic hepatitis B had increased risk for poorer health outcomes compared to the general population; however, the magnitude of risk varied greatly depending on baseline patient and disease characteristics, and typically clinical outcomes required many years to become manifest. Many adults with chronic hepatitis B had low absolute risks of clinical outcomes and likely would not benefit from immediate treatment. Baseline patient and disease characteristics provide important information about the risk of clinical outcomes and should be incorporated into monitoring or treatment decisions. (Hepatology 2009;49:S85–S95.)
Liver biopsy findings in chronic hepatitis B #
Authors: Mani Haresh , Kleiner David E. 
Published: July 2010

Abstract
Liver biopsy plays a central role in treatment algorithms in patients with hepatitis B and remains the gold standard for evaluating hepatic pathology. The pathology of hepatitis B is diverse and reflects the natural history of infection. An acute hepatitic pattern with lobular disarray is seen in acute infection, during acute flares of disease, and with acute hepatitis D superinfection. In chronic hepatitis B, inflammation is less pronounced in the immune-tolerant phase and is prominent during immune-mediated viral clearance. Active inflammation appears to be the driving force for development of fibrosis. Inflammatory grades and fibrosis stage are assigned as is done for hepatitis C. Although current management guidelines recommend liver biopsies only in select patients based on age, viral levels, and hepatitis B e antigen status, these clinical and biochemical parameters do not show consistent correlations with liver histology. Liver biopsy also helps identify preneoplastic lesions including large cell and small cell change. Unlike in other causes of chronic hepatitis, immunostains are widely used and can help determine the phase of infection. Liver biopsies can also identify additional pathology that may contribute to liver disease such as steatohepatitis, iron overload, autoimmune hepatitis, and drug-induced injury. Thus, liver biopsy can play an important role in staging and grading chronic hepatitis B and should be more widely used in assessing the need for therapy. (Hepatology 2009;49:S61–S71.)
Epidemiology of hepatitis B in the United States #
Authors: Kim Ray W. 
Published: July 2010

Abstract
Hepatitis B virus (HBV) remains an important cause of acute and chronic liver disease globally and in the United States. An encouraging trend is that the incidence of acute hepatitis B in the United States declined as much as 80% between 1987 and 2004, attributable to effective vaccination programs as well as universal precautions in needle use and in healthcare in general. Although encouraging, these decreases in acute infections have not translated into diminished prevalence or burden of chronic HBV infection. The prevalence for HBV in the United States has been estimated to be approximately 0.4%. However, these estimates have been based on surveys conducted in samples in which population groups with high prevalence of HBV infection, namely foreign-born minorities, were underrepresented. Voluntary screening data indicate prevalence in excess of 15% in some of these groups. Recent immigration trends suggest a substantial increase in the number of Americans with chronic HBV infection. This trend is reflected in the health and economic burden associated with HBV infection. The number of outpatient visits and hospitalizations for a HBV-related diagnosis increased several-fold during the 1990s. Similarly, the total charges for hospitalizations have been estimated to have increased from $357 million in 1990 to $1.5 billion in 2003. Most recent data indicate that death and liver transplant waitlist registration for HBV-related liver disease, which had been increasing, have now reached a plateau or started to decline. This encouraging trend might be attributable to recent advances in treatment for HBV infection; however, to the extent that the number of Americans living with chronic HBV is growing, careful clinical monitoring and continued epidemiologic surveillance remain important. (Hepatology 2009;49:S28–S34.)
Evaluation of the patient with hepatitis B #
Authors: Rotman Yaron , Brown Thomas A. , Hoofnagle Jay H. 
Published: July 2010

Abstract
The initial evaluation of a patient with hepatitis B virus infection should attempt to assess the disease activity and stage in the context of the known natural history of this infection and to properly assess the needs for treatment and surveillance. In addition to a medical history and focused physical examination, the initial evaluation usually requires serological, biochemical, and virological tests to confirm the diagnosis as well as an imaging study to establish a baseline for future monitoring. A liver biopsy is generally not needed but can provide useful information on prognosis, need for surveillance for hepatocellular carcinoma (HCC), and whether to recommend therapy. Follow-up monitoring is aimed at determining disease progression, development of complications, and reassessing the need for treatment. Monitoring frequency should be determined based on the activity and stage of disease. Initiation of screening for HCC should be based on age, race, sex, family history, and stage and duration of disease. The current recommended method of screening and surveillance for HCC is by ultrasonography and alpha-fetoprotein measurements every 6–12 months. Prospective studies are needed to evaluate the role of longitudinal application of noninvasive assays of fibrosis, such as serum fibrosis markers and transient elastography. Better biomarkers and imaging modalities are needed for early detection of HCC. Finally, studies are needed to better refine the indications and to balance the risks and benefits of antiviral therapy. (Hepatology 2009;49:S22–S27.)
The mechanical properties of films. II. The glass/rubber transition temperature
Authors: Holt T. , Bridge L. , Simpson W. 
Published: July 2010

AbstractA mechanical method of investigating transitional behaviour is described in which the stress developed in supported polymer films is observed as a function of temperature. The method has given information on transition temperatures which has been useful in work involving the dynamic elastic properties of the polymers and the WLF equation. The method is not sufficiently sensitive to resolve all the transitions observed dilatometrically and an empirical method of ‘averaging’ the latter gave results consistently 10–15°c higher than the ‘mechanical’ value.
The loss of mercury from fungicidal paints
Authors: Taylor C. G. 
Published: July 2010

AbstractReports have indicated that the use of mercury compounds as fungicides in paints may lead to poisoning of persons spending long periods in proximity to these paints. The loss of mercury from a typical fungicidal paint has been measured over a three‐month period by a radioactive tracer technique. Results indicate that, although loss occurs, its rate is not likely to cause, in a normal sized, adequately ventilated room, a concentration of mercury greater than the maximum accetable level for adult exposure.
Reactions of benzene in a microwave discharge reactor
Authors: Brooks B. W. , Sambrook R. M. 
Published: July 2010

AbstractA study has been made of the reactions of benzene in a continuous‐flow microwave‐discharge reactor. The distribution of reaction products was found to depend on the reactor pressure and flow‐rate. By accounting for all reaction products (solid, liquid and gas) an overall mass balance was obtained. The reactions are not the result of simple pyrolysis.The insertion of nickel wire into the reactor enhanced the reactions which proceed via a radical—radical mechanism. The addition of carbon dioxide to the benzene feed appeared to retard reactions which involve highly energetic ionisation processes. Thus, the presence of carbon dioxide changed the reaction selectivity. The carbon dioxide did not react chemically.Comparison with other work with benzene shows that the behaviour of this reactor system is significantly different from the behaviour of reactors which operate at a lower frequency. It is suggested that the distribution of electron energies in the microwave discharge is narrower than the energy distributions which are encountered in lower‐frequency and d.c. discharges.
Kinetics of benzene hydrogenation by supported nickel at low temperature
Authors: Kehoe J. P. G. , Butt J. B. 
Published: July 2010

AbstractA study of the kinetics of benzene hydrogenation at low temperatures is described which confirms and completes the present fragmentary information available in the literature. Such analysis may also be useful for the purposes of using the reaction as a model system in studies of reaction engineering problems.The results are consistent with a Rideal mechanism for the hydrogenation, proceeding via the molecular addition of hydrogen to adsorbed benzene. The very strong adsorption and the range of conditions over which zero order kinetics with respect to benzene are found support the π‐bonding theory for benzene chemisorption.
Continuously synchronised growth
Authors: Dawson P. S. S. 
Published: July 2010

AbstractThe advent of cell synchrony as a refinement in technique for cultivating microbes has given new dimensions to the study of microbial growth.By wedding synchrony to continuous culture, it becomes possible to convert and resolve the invariant (steady state) performance of asynchronous growth in a chemostat into a recognisable pattern of (cell cycle) activity, which repeats continually and occupies the mean doubling time periods of the cells growing in synchrony in a continuously synchronised culture. In this way, microbial growth and metabolism in a culture can be considered in terms of the individual cell instead of being related to the statistical mean of the cell population.Growth, continuous growth and continuously synchronised growth are considered in relation to these developments and an approach is made to account for the “physiological state”.
Kinetics of the vapour‐phase dehydrogenation of cyclohexane over palladium catalyst in a continuous stirred tank reactor
Authors: Rouleau D. , Klvana D. , Sang J. 
Published: July 2010

AbstractThe catalytic vapour‐phase dehydrogenation of cyclohexane has been investigated over a surface coated palladium catalyst in a continuous stirred tank reactor between 482 and 644°F and at different partial pressures (0 to 2 atm) of cyclohexane. The rate data obtained have been analysed by the Hougen—Watson method. Non‐linear least squares analyses combined with other statistical considerations were used to discriminate among rival models. The following Hougen—Watson type rate equation has been proposedThe constants in the rate equation have been expressed as functions of temperature.
Blistering in bituminous coatings
Authors: Biloen P. , Bonn R. , Marys P. D. , Spoon W. A. 
Published: July 2010

AbstractThermodynamical arguments together with the solutions of some diffusion equations lead to the theory that one of the causes of blistering of bituminous coatings is the variation in gas pressure; for instance the blistering of a coating that covers the inside of hydrophore installations. This theory has been confirmed by some experiments. A model is discussed that gives a quantitative description of the blistering. Laboratory results are discussed in view of the model predictions. A procedure is proposed to extrapolate the experimental results under laboratory conditions to practical conditions, i.e. simple laboratory experiments can be performed with a given type of bituminous coating that will show whether or not blistering will occur in practice.
Viscosity of methanol + benzene mixtures
Authors: Medani M. S. 
Published: July 2010

AbstractThe viscosity of pure methanol and benzene have been determined at 35, 40, 45, 50 and 55°C in a Canon—Fenske viscometer. Values of the viscosity coefficients were fitted to De Guzman's equation, i.e.

where it was shown that both A and Evisc for the two compounds are functions of temperature.The viscosity of 10 different concentration levels of methanol + benzene mixtures have also been measured at 35, 40 and 45°C. Points of maximum and minimum viscosities were shown to exist, the compositions of which vary with temperature.Estimates of the viscosity coefficients of methanol + benzene mixtures at 100, 120, 160 and 200°C have been made from the vapour‐liquid equilibrium data of this system. It was found that points of minimum viscosity still exist while points of maximum viscosity have disappeared. These phenomena are discussed in terms of the dissociation of methanol “polymers” and the formation of benzene + methanol complexes.