Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We prepared and crystallized five complexes of the human histocompatibility molecule HLA-A2 with peptides derived from human immunodeficiency virus type 1, human T lymphotropic virus type 1, influenza A virus and hepatitis B virus proteins. Each HLA-A2 complex was refolded in vitro from insoluble proteins produced in bacteria; to crystallize, two of the complexes required seeding with microcrystals of another complex. Maintained at -160 degrees C, single co-crystals of each of the five peptide-HLA-A2 complexes yielded complete X-ray diffraction data sets to a resolution of approximately 2.5 A. After a sufficient number of diffraction peaks were acquired during data collection, the direct analysis of integrated intensities established the point group of the co-crystal, thus allowing an efficient data collection strategy to be designed. The subsequent examination of systematic absences revealed that the five peptide-HLA-A2 co-crystals formed in space groups P1, P2(1), or P2(1)2(1)2(1). Molecular replacement structure solutions yielded unambiguous protein electron density maps, thus confirming the space group determinations. The system of obtaining HLA-A2 co-crystal structures described here is applicable to other crystallographic problems where structures of several related molecules from uncharacterized single crystals are required.
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PMID:Five viral peptide-HLA-A2 co-crystals. Simultaneous space group determination and X-ray data collection. 751 39

Cooperation between B cells specific for an antigen exposed on a viral structure and T helper (Th) cells specific for an internal antigen, as demonstrated with influenza, hepatitis B and rabies viruses, has been termed intrastructural help. Th cells specific for internal proteins of HIV, which are much less mutated than its exposed antigens, may be valuable in vaccine design against this virus. We investigated the human Th repertoire specific for the core HIV antigen reverse transcriptase (p66), and determined whether these cells could be candidate intrastructural T helpers. CD4+ T lines and clones were generated from non-immune individuals by stimulation with p66-pulsed antigen-presenting cells (APC). Specific lines were obtained with p66 from 19 out of 21 (90%) of these individuals, vs. 7 out of 29 (24%) with gp120. Diverse epitopes were recognized by different individuals, and various V beta genes were used by these clones. Clones using the same V beta genes were of diverse origin, according to VDJ region sequence. Of these lines 45% responded to p66 in the context of HIV virions. Moreover, p66-specific clones could respond to APC that had internalized HIV complexed with envelope-specific monoclonal antibodies, suggesting that p66-specific Th cells may participate in intrastructural help. These studies indicate that p66-specific Th cells are detectable in vitro in most naive individuals and exhibit clonal heterogeneity, and that the majority recognize an HIV conserved antigen. They respond to p66 following processing of whole virions and are clearly candidates for intrastructural help. If confirmed in vivo, p66 should be included among vaccine candidates investigated to optimize the anti-HIV Th response.
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PMID:Human T helper cells specific for HIV reverse transcriptase: possible role in intrastructural help for HIV envelope-specific antibodies. 753 50

To assess the efficacy of recombinant alfa 2b-interferon treatment "Heberon alfa R" in children with chronic active hepatitis (CAH) B virus, we conducted a long-term study (three years) in 22 children infected with hepatitis B virus (17 males and 5 females), age range 3 to 15 years. Diagnostic criteria included the clinical picture, laboratory tests, virus markers (HBeAg, HBsAg), laparoscopy and liver biopsy. Children under 12 years received 3 million IU of interferon per day whereas those older than 12 years received 6 million IU of interferon per day by intramuscular injection, three times per week for four months. Alanine aminotransferase (ALT) levels had been elevated for six months in all patients and hepatitis B viral infection was replicative. A variance analysis was made to evaluate ALT response to interferon administration and the Mc Nemar test was used to analyze HBeAg/anti-HBe behavior. Seventeen (77%) out of 22 patients responded to treatment (clearance of HBeAg and ALT levels returned to normal. HBeAg seroconversion (anti-HBe) occurred in 36% of patients during the first year (p < 0.01) and it increased to 50% by the third year follow-up. ALAT levels also decreased and the difference was statistically significant (p < 0.01). This occurred during and after treatment with a steady and increasing tendency to return to normal levels within the first and third year. Side effects were scarce, transient and tolerable and they only appeared during the initial phase of treatment; symptoms were mainly influenza-like and they disappeared very soon. There were no late side effects such as medullar depression, renal toxicity and glycemia alterations.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Long term study of the treatment with recombinant alfa 2b interferon in chronic active hepatitis due to B virus in children and adolescents]. 755 76

A defect in the immune response of patients with chronic renal failure leads to low response rates and insufficient antibody concentrations following a number of highly recommended vaccinations. This has been shown before for immunization against hepatitis B and influenza. Few data are available concerning the efficacy of vaccination with tetanus toxoid in these patients. In a prospective, controlled study we vaccinated seronegative patients with chronic renal failure not on dialysis, patients on chronic intermittent hemodialysis, and patients after kidney transplantation with tetanus toxoid. The results were compared with those of a control group consisting of 13 age-matched patients with mild essential hypertension and normal kidney function. Only 11 of 20 (55%) patients in the chronic renal failure group and 16 of 23 (69%) in the dialysis group had a protective antibody response after triple vaccination. In contrast, all the patients in the control group and six of seven transplant patients seroconverted. The response to tetanus toxoid was highly associated with the response to a previously administered vaccination against hepatitis B. Responders to this vaccination also had a better response rate to tetanus toxoid. The antibody concentrations after vaccination were lower in all patient groups compared with the controls; the lowest titers were found in the transplant patients. Therefore, renal patients will need revaccination much earlier, and tetanus toxoid antibody levels should be checked if a patient is injured and potentially requires vaccination.
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PMID:Tetanus immunization and its association to hepatitis B vaccination in patients with chronic renal failure. 764 53

Complexes of five peptides (from HIV-1, influenza A virus, HTLV-1, and hepatitis B virus proteins) bound to the human class I MHC molecule HLA-A2 have been studied by X-ray crystallography. While the peptide termini and their second and C-terminal anchor side chains are bound similarly in all five cases, the main chain and side chain conformations of each peptide are strikingly different in the center of the binding site, and these differences are accessible to direct TCR recognition. Each of the central peptide residues is seen to point up for some bound peptides, but down or sideways for others. Thus, although fixed at its ends, the structure of an MHC-bound peptide appears to be a highly complex function of its entire sequence, potentially sensitive to even small sequence differences. In contrast, MHC structural variation is relatively limited. These results offer a structural framework for understanding the role of nonanchor peptide side chains in both peptide-MHC binding affinity and TCR recognition.
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PMID:The antigenic identity of peptide-MHC complexes: a comparison of the conformations of five viral peptides presented by HLA-A2. 769 6

Allogeneic bone marrow transplant patients are severely immunocompromised during the immediate posttransplant period, and the risk for common and opportunistic infections may persist for many months. The role of reimmunization for these patients, however, remains unsettled. We briefly review current concepts regarding the recapitulation of immunity from the totipotential hematopoietic stem cells in the donor marrow. The fact that various components of the new immune system mature at different rates can have clinical consequences with regard to specific infections. Most previously immunized patients become antibody seronegative within a few months after allogeneic marrow transplantation. Adoptive transfer of specific antibody-producing cells from the donor to the recipient has been demonstrated in small clinical trials, and is augmented when both donor and recipient are vaccinated. Passive transfer of immunity is more easily achieved to recall antigens than to neoantigens. Primary immunization requires prolonged antigenic stimulation and mature T-cell function or help from natural killer cells. Most healthy patients generate adequate antibody titers to vaccinations that are given 12 months after transplantation, but the presence of chronic graft-versus-host disease can diminish the response. Currently available vaccines have been evaluated in marrow transplant patients. Protein antigens such as tetanus and diphtheria toxoids are more immunogenic than polysaccharide antigens such as pneumococcal vaccine. The new polysaccharide-protein conjugate vaccines, such as the Hemophilus influenzae type b vaccine, also appear more immunogenic. Inactivated poliovirus vaccine has been used successfully. Relatively few data are available about hepatitis B or influenza vaccines. The literature supports the use of standard vaccines in allogeneic bone marrow transplant patients. However, more data on the optimal methods and timing of immunization are needed. We present guidelines for a reimmunization schedule.
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PMID:Reimmunization after allogeneic bone marrow transplantation. 770 53

Early intervention for persons infected with human immunodeficiency virus (HIV) involves characterization of the stage of HIV disease, institution of therapy to prevent associated infections and postpone deterioration of immune function, and assistance in preventing transmission of the virus. This review examines the available data on the efficacy of current recommendations regarding the evaluation and management of persons with early HIV infection. Existing evidence supports the efficacy of physical examination, monitoring of the CD4+ cell count, tuberculin testing (with chemotherapy for persons who test positive), anergy testing, Papanicolaou testing and screening for gonorrhea and chlamydial infection (for high-risk women), screening for syphilis, antiretroviral therapy (for symptomatic patients), and guidance in reducing the transmission of HIV. Recommended measures for which evidence of clinical efficacy is less certain include immunization against infections due to influenza virus, Streptococcus pneumoniae, Haemophilus influenzae, and hepatitis B virus as well as antiretroviral therapy for asymptomatic persons. Quantitative measurement of viral titers appears promising for the monitoring of HIV disease and antiretroviral therapy; the correlations of these titers with clinical end points need to be confirmed.
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PMID:Early intervention for persons infected with human immunodeficiency virus. 779 7

A large portion of our older adult patients remain unimmunised or inadequately immunised against tetanus. The US is unique in that clinical tetanus occurs mostly in persons aged over 60 years. Worldwide, it is a disease of neonates. Both pneumococcal diseases and influenza cause markedly greater morbidity and mortality among elderly people compared with younger people. The prevalence of these chronic diseases can be decreased by immunising susceptible persons against the relevant infections. Hepatitis B is also a worldwide problem, causing a large number of acute infections and costly sequelae, 95% of which is preventable by hepatitis B vaccine. Rabies is a very lethal disease preventable by use of rabies vaccine. The decreased function of the aging immune system results in far fewer older persons developing antibodies following immunisation than their younger counterparts.
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PMID:Vaccinating elderly people. Protecting from avoidable disease. 782 95

Many infections that occur at the extremes of age are preventable by active or passive immunization. The immune response to vaccines in neonates and the elderly may be diminished when compared with other age groups, however this is usually outweighed by the benefits of providing protection at the age when the need is greatest. Immunoprophylactic agents used at birth include BCG vaccine, oral polio vaccine, varicella-zoster immunoglobulin and hepatitis B vaccine and immunoglobulin. In the elderly, influenza, pneumococcal and tetanus vaccines are often indicated, although the uptake in this age group is poor in comparison with neonates.
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PMID:Immunoprophylaxis at extremes of age. 784 68

Recent additions to the immunization schedule include acellular pertussis vaccine, and hepatitis B vaccine for all infants and selected adolescents. The third dose of OPV is recommended at 6 months of age and the first dose of MMR vaccine at 12 to 15 months. A new vaccine against Haemophilus influenzae type b has been licensed. Children aged 6 months and older with asthma, diabetes, or heart disease should receive influenza vaccine. Children aged 2 years and older with asplenia, immunosuppression, and nephrotic syndrome may be candidates for pneumococcal immunization.
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PMID:Childhood immunization guidelines: current and future. 785 58


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