515 research outputs found
Detection of hepatitis B virus X product using an open reading frame Escherichia coli expression vector.
Aplastic anemia and hepatitis C: Molecular biology exonerates another suspect
Objective. – To test the hypothesis that the rare, often fatal, syndrome of hepatitis-associated aplasia is associated with hepatitis C virus infection. Design. – Case series. Setting.-Tertiary referral centers in the United States, Japan, Italy, and Germany. Patients. – Twenty-eight patients with onset of aplastic anemia within 90 days after seeking medical attention for jaundice, or having serum transaminase levels 150% or more of normal (hepatitis-associated aplasia patients) and three patients who developed aplastic anemia following liver transplantation for non-A, non-B, hepatitis. Outcome Measures. - Presence of hepatitis C in serum, bone marrow, and liver samples, detected by the polymerase chain reaction; antibody testing; and percentage of activated peripheral cytotoxic T lymphocytes determined by immunophenotyping. Results. – Hepatitis ribonucleic acid was present in the serum samples of 10 (36%) patients with hepatitis-associated aplasia. However, hepatitic C virus viremia was associated with transfusions received after the onset of aplasia: seven (58%) of 12 patients with hepatitis-associated aplasia who had received 21 or more units of blood products at the time of serum sampling were viremic, compared with only three (19%) of 16 patients with hepatitis-associated aplasia who had received 20 or less units of blood products ( P <.05). Hepatitis C virus was not found in blood and bone marrow samples of three National Institutes of Health case patients tested at the time of diagnosis. None of three livers from non-A, non-B hepatitis patients who developed aplastic anemia after liver transplantation contained hepatitis C virus ribonucleic acid. Activated CD8 + T lymphocytes were elevated three- to 20-fold early in the course of hepatitis-associated aplasia. Conclusions. – Our results implicate a novel, non-A, non-B, and non-C agent in both hepatitis-associated aplasia and fulminant hepatitis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38390/1/1840170227_ftp.pd
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Prevalence and clinical correlates of YMDD variants during lamivudine therapy for patients with chronic hepatitis B
YMDD variants of hepatitis B virus (HBV) emerge in some patients with chronic hepatitis B who receive lamivudine. YMDD variants were examined in 794 patients in 4 controlled studies of 1 year's duration. The long-term effects of YMDD variants were examined in a subset of patients treated up to 4 years. YMDD variants were detected by polymerase chain reaction (PCR) and restriction fragment-length polymorphism assays. After 1 year, YMDD variants were detected in 81 (24%) of 335 patients. In these patients, the median serum HBV DNA concentration at 1 year was <20% of the baseline level, and serum alanine transaminase (ALT) levels and liver histologic findings had significantly improved. In patients with YMDD variants who were treated for up to 4 years, median HBV DNA and ALT levels showed improvements. Sex, baseline body mass index, and HBV DNA level were associated with emergence of YMDD variants. Patients with YMDD variants losing clinical response with a significant increase in the HBV DNA and ALT levels may require additional therapy.published_or_final_versio
Pros and Cons of Peginterferon Versus Nucleos(t)ide Analogues for Treatment of Chronic Hepatitis B
The emergence of new and more potent treatment options has markedly changed the treatment landscape of chronic hepatitis B. Both peginterferon and nucleos(t)ide analogues have considerable advantages and limitations, and current treatment guidelines refrain from clearly suggesting a first-line treatment option. Peginterferon offers the advantage of higher sustained response rates in both hepatitis B early antigen (HBeAg)-positive and HBeAg-negative patients, at the price of considerable side effects and high costs. Nucleos(t)ide analogues offer easy daily oral dosing, and newly registered agents can maintain viral suppression for prolonged treatment duration. However, relapse is common after therapy discontinuation and extended therapy therefore often necessary. Prolonged treatment with nucleos(t)ide analogues may enhance chances of virologic and serologic response at the potential cost of the emergence of viral resistance and side effects. Baseline and on-treatment prediction of response may help select patients for peginterferon therapy and can aid individualized treatment decisions concerning therapy continuation or discontinuation
Chemistry courses as the turning point for premedical students
Previous research has documented that negative experiences in chemistry courses are a major factor that discourages many students from continuing in premedical studies. This adverse impact affects women and students from under-represented minority (URM) groups disproportionately. To determine if chemistry courses have a similar effect at a large public university, we surveyed 1,036 students from three entering cohorts at the University of California, Berkeley. We surveyed students at the beginning of their first year at the university and again at the end of their second year. All subjects had indicated an interest in premedical studies at the time they entered the university. We conducted follow-up interviews with a stratified sub-set of 63 survey respondents to explore the factors that affected their level of interest in premedical studies. Using a 10-point scale, we found that the strength of interest in premedical studies declined for all racial/ethnic groups. In the follow-up interviews, students identified chemistry courses as the principal factor contributing to their reported loss of interest. URM students especially often stated that chemistry courses caused them to abandon their hopes of becoming a physician. Consistent with reports over more than 50 years, it appears that undergraduate courses in chemistry have the effect of discouraging otherwise qualified students, as reflected in their admission to one of the most highly selective public universities in the US, from continuing in premedical studies, especially in the case of URM students. Reassessment of this role for chemistry courses may be overdue
Basic Biomedical Sciences and the Future of Medical Education: Implications for Internal Medicine
The academic model of medical education in the United States is facing substantial challenges. Apprenticeship experiences with clinical faculty are increasingly important in most medical schools and residency programs. This trend threatens to separate clinical education from the scientific foundations of medical practice. Paradoxically, this devaluation of biomedical science is occurring as the ability to use new discoveries to rationalize clinical decision making is rapidly expanding. Understanding the scientific foundations of medical practice and the ability to apply them in the care of patients separates the physician from other health care professionals. The de-emphasis of biomedical science in medical education poses particular dangers for the future of internal medicine as the satisfaction derived from the application of science to the solving of a clinical problem has been a central attraction of the specialty. Internists should be engaged in the ongoing discussions of medical education reform and provide a strong voice in support of rigorous scientific training for the profession
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