Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is my great honor to dedicate this article to Professor Ludwig C. Yen at the occasion of the Annual Meeting of the Chinese Society of Microbiology, commemorating his 101st Birthday. I have had the privilege of being one of the earliest students of Professor Yen, and as a staff member working for 16 years under him, I have been benefited enormously from his teachings. I am most grateful to Dr. Czausiung Yang and the executive board members of the Chinese Society of Microbiology for giving me this opportunity to present some of my research activities which would be relevant to Professor Yen's teachings. Introduction to the evolutionary view of host-parasite relationship was one of the many contributions Professor Yen made to enlighten students and colleagues as early as in 1940. As promulgated by Professor Yen, natural history of infectious diseases has witnessed the reality of Theobald Smith's premise, "pathogenicity of microorganisms is an accident in the evolutionary processes of host-parasite relationship, and the outcome of evolutionary forces is a modus vivendi (a feasible compromise) according to which the parasite and the host reach some sort of equilibrium which permits the survival of both"(1). These evolutionary concept has since become a common knowledge for modern students of infectious diseases. The natural history of recently discovered human retroviruses such as HTLVs (human T-lymphotropic viruses) and HIVs (human immunodeficiency viruses) has amply demonstrated the truth of the premise. I shall review some results of our research which would be of relevance to the evolution of viral quasispecies and variants, viral oncogenes, and the cellular as well as viral regulatory genes. I shall focus on the roles played by these genes in the delicate and complex balance of host-virus relationships, and on their association with cellular differentiation and oncogenesis.
Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1991 Feb
PMID:An evolutionary view of viral regulatory genes. 165 42

The prevalence of antibodies to hepatitis C virus (anti-HCV) was investigated among different populations in Taiwan, where anti-HCV was detected in 0.8% (24/2,994) of adult volunteer blood donors, 0.1% (1/1,305) of youngsters and children, 12.5% (8/64) of adult volunteer blood donors with elevated alanine aminotransferase (ALT), 36.5% (23/63) of hemodialysis patients, 4.1% (13/318) of male homosexuals, 25.4% (16/63) of cases positive for antibodies to human immunodeficiency virus (anti-HIV), 82.2% (578/703) of intravenous drug users (IVDUs), and 10.3% (23/223) of female prostitutes (FPs). Among patients with chronic liver diseases including chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC), the overall prevalence rate for anti-HCV was 34.1% (42/123), and a higher prevalence was noted in hepatitis B surface antigen (HBsAg)-negative cases than in HBsAg-positive cases. The prevalence of anti-HCV in volunteer blood donors and high prevalence found in IVDUs, hemodialysis patients, anti-HIV positive cases, and FPs are consistent with those results from other countries. These findings suggest that hepatitis C virus (HCV) infection is transmitted by both blood-borne and sexual contact routes. Among flavivirus infections, anti-HCV was detected in 0.3% (1/289) and 1.3% (4/310) of Japanese encephalitis and dengue fever patients, respectively. In conclusion, in Taiwan, an area with high endemicity of hepatitis B virus (HBV) infection, the epidemiological status of HCV infection is similar to that observed in other countries, and no serum cross-reactivity was noticed between HCV and flavivirus infections.
Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1991 Feb
PMID:Prevalence of antibodies to hepatitis C virus (anti-HCV) in different populations in Taiwan. 165 45

The binding of substrates to recombinant reverse transcriptase from human immunodeficiency virus (HIV) and the natural enzyme from avian myeloblastosis virus (AMV) has been examined by analyzing both the ribonuclease H and the RNA-dependent DNA polymerase activities. With 3'-end-labeled globin mRNA hybridized to (dT)15 as the substrate in the ribonuclease H reaction, the enzymes partially deadenylated the mRNA in a distributive manner. Under these conditions, there was a rapid initial burst followed by a prolonged, but much slower, steady-state rate. The biphasic reaction made possible determinations of kinetic constants as follows: values for Km, KD, and kcat were, respectively, 27 nM, 11 nM, and 5 x 10(-3) s-1 for the HIV enzyme and 30 nM, 9 nM, and 5 x 10(-3) s-1, respectively, for the avian enzyme. These constants were used to derive other parameters: The rate of association of the template-primer with reverse transcriptase was approximately 2 x 10(5) M-1 s-1, and the rate of dissociation was approximately 2 x 10(-3) s-1, regardless of the source of the enzyme. The rate of release of the product was essentially equivalent to the value of kcat indicated above for each of the enzymes. The polymerase reaction was evaluated under processive conditions of synthesis; values of Km and kcat of approximately 6 nM and approximately 2.5 s-1, respectively, for the human enzyme, and approximately 10 nM and approximately 2 s-1, respectively, for the avian enzyme were observed. The interaction of substrates with HIV reverse transcriptase was characterized further with the aid of ribonucleoside-vanadyl complexes. These complexes inhibited the polymerase and ribonuclease H activities of the enzyme competitively with respect to globin mRNA.(dT)15. Values of Ki ranging from 1 to 3 mM were obtained. With respect to deoxyribonucleoside triphosphate substrates in the polymerase reaction, mixed inhibition was observed. Deoxyribonucleoside triphosphates had no effect on kinetic parameters governing the ribonuclease H activity of the HIV enzyme but apparently facilitated the formation of active enzyme. These data fit a model in which one template-primer binding site serves both the polymerase and the ribonuclease H catalytic sites.
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PMID:Reverse transcriptase from human immunodeficiency virus: a single template-primer binding site serves two physically separable catalytic functions. 171 23

Eleven cases of severe type hemophiliacs who had received long-term factor VIII injections were tested for the serological markers of human immunodeficiency virus (HIV), hepatitis B virus and hepatitis C virus (HCV). The period of factor VIII concentrate injections ranged from 2 to 32 years. The seropositive rates of HIV and HCV were 9/11(82%) and 11/11(100%), respectively. The seropositive rate of hepatitis B surface antigen was only 1/11(9%), while the seropositive rates of antibody to hepatitis B core antigen and antibody to hepatitis B surface antigen were 9/11(82%) and 7/11(64%), respectively, Although the patients had no symptoms related to acquired immunodeficiency syndrome, they were noted to have inverted helper/suppressor T-lymphocyte ratio, suggesting that hemophiliacs with long-term factor VIII injections have a high incidence of HIV and HCV infection, with immunological aberration.
Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1991 Nov
PMID:HIV, HBV and HCV seropositivity in hemophiliacs. 172 73

A procedure to diagnose the infections by the human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) was proposed. The specimens were first screened by a mixed enzyme immunoassay (EIA) for the presence of antibodies to HIV-1 as well as to HIV-2. Those screened positive were thereafter confirmed and differentiated their antibody reactivities toward the antigens of HIV-1 and HIV-2 by Western blot (WB). This procedure was found to be one hundred percent accurate to diagnose 66 coded specimens with well defined seroreactivities to HIV-1 from Centers for Disease Control (CDC). While its accuracy in HIV-2 antibody testing could not be evaluated in the present study owing to the lack of HIV-2 standard reference specimens. With this procedure, six out of each of two groups of 176 foreigners and 719 individuals who visited the Taipei Municipal Venereal Disease Control Institute (TMVDCI) were screened repeatedly reactive by the mixed EIA. By WB only four of the first six and two of the second six were confirmed HIV-1 positive. Their antibody reactivities toward HIV-2 antigens were either absent or significantly much lower than those toward HIV-1 antigens. Furthermore, none reacted to the env proteins gp160 and gp120 of HIV-2. We therefore concluded that out of the 895 test individuals, only six were confirmed infected with HIV-1. There were neither HIV-2 infections nor dual infections. The similar pathogenicity and trans mission of HIV-2 as of HIV-1 justify an equal appreciation for HIV-2 testing. The present study indicated that a procedure starting with a mixed EIA aimed to diagnose HIV-1 as well as HIV-2 did not have any adverse effects on HIV-1 testing.
Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1990 Nov
PMID:Application of a procedure starting with an HIV-I/HIV-2 mixed EIA. 198 37

Carbovir is a carbocyclic guanosine analogue with potent in vitro activity against the human immunodeficiency virus. All of the activity resides in the (-)-enantiomer. An ion-paired liquid chromatographic assay for (-)-carbovir was developed on a Spherisorb C8 column with fluorescence detection (275 nm excitation, 345 nm emission). Guanosine nucleosides are fluorescent at a pH less than 2.5, and fluorescence detection resulted in a four-fold improvement in the limit of quantitation (0.039 microgram/ml) compared to the previously developed assay with ultraviolet detection. Standard curves were processed with an internal standard at (-)-carbovir concentrations of 0.039-40 micrograms/ml in whole rat blood with a solid-phase extraction technique. Total variability was less than 16% at all concentrations and less than 10% at concentrations greater than 0.3 microgram/ml. Within-day variability was less than 7.5% at concentrations greater than 0.3 microgram/ml. Urine was analyzed directly after dilution and an diethyl ether wash to remove impurities. The total coefficients of variation were less than 10% from 0.5-20 micrograms/ml in urine. The concentrations of (-)-carbovir in rat blood were detectable for as long as 8 h after intravenous and oral doses of 20 and 60 mg/kg, respectively.
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PMID:Improved fluorometric high-performance liquid chromatographic assay for (-)-carbovir in rat blood and urine. 209 97

Viral markers of hepatitis B virus (HBV), cytomegalovirus (CMV) and human immunodeficiency virus (HIV), immunoglobulins and complements, T-cell subpopulation antibodies (OKT series) and mitogen responses have been investigated in 68 multitransfused thalassemic patients and in 46 age-matched children. Results showed (1) 56 patients (82.4%) had been exposed to HBV; 29 patients (42.6%) had been exposed to CMV and none were HIV infection. (2) Increased IgG, IgA, OKIal, and decreased C3, OKT3, OKT4, OKT4/OTK8 ratio showed in patients as compared to controls. (3) An apparent increase in lymphocyte proliferation was seen in patients' cultures with or without mitogen (PHA and ConA) stimulation. (4) No definite factors such as sex, age at first transfusion, number of transfusions or HBsAg carrier status correlated with the abnormal change of immunological tests. (5) Immunological investigation, done on 2 occasions six months apart, revealed no significant modifications except that 13 patients (19%) who were initially seronegative for CMV converted to seropositive. These investigations suggest that, although saline-washed RBC was used for the transfused patients, there was high prevalence of HBV and CMV infection. Further studies of lymphocyte function (i.e. lymphokines) are needed to understand the increased spontaneous proliferation in culture and PHA, ConA mitogen responses.
Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1990 Feb
PMID:Immunologic and virologic status of multitransfused thalassemic patients. 216 12

The utilization of alternative splice acceptors for excision of the 5' major intron of human immunodeficiency virus type 1 RNA was observed after infection in vitro. Specific splice events were monitored by a cDNA-polymerase chain reaction. These splice events shared a common splice donor but utilized several alternative splice acceptors. In addition to identifying the previously documented splice acceptors for tat and nef (S. K. Arya, C. Guo, S. F. Josephs, and F. Wong-Staal, Science 229:69-73, 1985), nucleotide sequence analysis of cDNA-polymerase chain reaction fragments also revealed the following: (i) two splice acceptors 15 and 9 nucleotides upstream from the rev start codon, which are utilized to create transcripts suitable for specific rev expression; and (ii) use of the splice acceptor previously attributed to nef to generate a singly spliced, env-encoding transcript. Hybridization signals representing the nef/env, tat, and rev splice events increased in intensity between 6 and 12 h after infection of CEM cells with the LAV-1BRU strain of human immunodeficiency virus type 1. In contrast, the signal for utilization of the nef/env splice acceptor for the singly spliced env transcript appeared first at 12 h and increased to maximum intensity by 24 h. The nef/env splice acceptor was dominant at all time points examined. We propose that this dominance ensures efficient downstream splicing proximal to the env initiation codon in singly spliced transcripts. However, early after infection, the dominance of the nef/env splice acceptor appears to divert primary transcripts away from tat- and rev-specific processing paths. The relative proportions of hybridization signals representing these alternative splice events remained constant throughout the viral replicative cycle. This result suggests that trans-acting factors that might influence splice choices are not induced during infection, but rather that cis-acting, sequence-specific splice preferences determine the relative efficiency of alternative acceptor utilization.
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PMID:Alternative splice acceptor utilization during human immunodeficiency virus type 1 infection of cultured cells. 238 14

Antibody profiles for hepatitis B virus (HBV), hepatitis A virus (HAV), cytomegalovirus (CMV), Epstein-Barr virus (EBV) and human immunodeficiency virus (HIV) were determined on 55 serum samples collected from patients with chronic renal failure who were on long-term haemodialysis for periods ranging from 8 months to 5 years and 3 months. The exposure rates for HBV, HAV, CMV, EBV and HIV were 94.5%, 100%, 94.5%, 94.5% and 0% respectively. Among the 7 HBsAg carriers, 1 and 3 were positive for e antigen (HBeAg) and antibody to HBeAg (anti-HBe), respectively and three negative for both. These 7 carriers were also negative for anti-delta antibody. A comparison of the above antiviral profiles to those of voluntary blood donors and general population in this district revealed tht there is no difference for HBV, HAV, CMV and EBV exposure rates, VDRL, alpha-fetoprotein and CEA were also tested and the results showed no abnormalities. Only 3 patients had abnormally elevated SGOT and SGPT levels; the causes were undetermined because all of them gave positive HBV, HAV, CMV and EBV antibody profiles. In conclusion the screening of HBsAg and VDRL in the blood banks virtually eliminated possible infections of HBV and spirochate by blood transfusion and the patients with chronic renal failure who are maintained on long-term haemodialysis are generally not at higher risks of hepatitis-related viral infections.
Zhonghua Min Guo Wei Sheng Wu Ji Mian Yi Xue Za Zhi 1987 Nov
PMID:[Hepatitis-related viral markers in patients under long-term hemodialysis]. 245 21

A series of test substrates have been synthesized to establish the effect of termini on the putative exoribonuclease H activity of reverse transcriptase. Recombinant reverse transcriptase from human immunodeficiency virus, natural enzyme from avian myeloblastosis virus, and a known endonuclease, Escherichia coli ribonuclease H, cleaved relaxed, circular, covalently closed plasmids in which 770 consecutive residues of one strand were ribonucleotides. The avian enzyme also deadenylated capped globin mRNA with a covalently attached oligo(dT) tail at the 3' end. These results resolve a long-standing controversy--that the viral enzymes are obligatory exonucleases in vitro, based on their failure to cleave certain substrates for E. coli ribonuclease H, including circular poly(A).linear poly(T) and ribonucleotide-substituted supercoiled plasmids, but resemble endonucleases in vivo, based on their ability to degrade RNA in complex DNA.RNA hybrids. The data strongly suggest that the viral enzymes are endonucleases with exquisite sensitivity to the conformation of heteroduplexes. Inhibition of viral, but not cellular, ribonuclease H with ribonucleoside-vanadyl complexes further distinguishes these enzymes.
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PMID:Ribonuclease H activities associated with viral reverse transcriptases are endonucleases. 247 Nov 88


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