Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have tested the sequence UUC CAG UCA GAC CU, at position 9016--9029 within the HIV-1(SF2) nef open reading frame, for accessibility to antisense and hammerhead ribozyme attack. The accessibility was first studied using a phosphorothioate-modified 14-nt DNA oligo (complementary to the nef9016--9029 site). A dose-dependent repression of HIV-1(SF2) growth was observed in human peripheral blood mononuclear cells after exogenous administration of the oligo to the cell culture medium. A hammerhead ribozyme with a 6+7-nt antisense specificity for the nef9016--9029 site (hhRz.nef9016--9029) was constructed and transfected into the human T-cell line HUT78. Again, a dose-dependent repression of virus growth was observed when different individual clones expressing hhRz.nef9016--9029 were infected with HIV-1(SF2). A complete abrogation of virus production was observed after infection with a low (0.5 TCID50) HIV-1 titer. Increasing doses (2.5 and 12.5 TCID50) of HIV-1 virus yielded a low production (10(3)-fold reduced) of virus particles in most cases; but a complete, or close to complete, abrogation was observed even in individual cultures infected with the highest dose. Presence of proviral pol and gag sequences in hhRz.nef9016--9029-expressing HUT78 clones was assayed, using PCR. Interestingly, since no pol and gag PCR products could be detected, the results strongly indicated that the hammerhead ribozyme was already acting on the infecting HIV RNA before its reverse transcription and integration as proviral DNA. In summary, the results obtained in this study support the nef9016--9029 site as a strong new candidate for ribozymal gene therapy against HIV-1 infection.
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PMID:A novel ribozyme target site located in the HIV-1 nef open reading frame. 862 25

Th1 and Th2 cells play a central role in immunoregulation during infection. We show that Helicobacter pylori induces Th1 cytokine responses early (2 weeks) but predominantly Th2 responses later (6 weeks) in infection. The switch is principally mediated by urease-specific CD4(+) T cells, and correlates with a loss of urease-specific high-avidity JNK(+) Th1 and gain of low-avidity JNK(-) (possibly Th2) cells at the later stage of infection, concomitant with a 100-fold higher colonization level of H. pylori at 6 weeks than at 2 weeks that might tolerize high-avidity Th1 cells. Furthermore, differentiation of HIV gp160-specific CD4(+) Th and CD8(+) cytotoxic T lymphocytes (CTL) into effector cells is impaired in 6-week H. pylori-infected mice immunized with vaccinia expressing gp160, and serum IL-12 stimulated by vaccinia infection is barely detectable. Adoptive transfer of urease-specific Th2 cells to mice infected only with gp160-expressing vaccinia abrogates Th1 polarization of the gp120 response, down-modulates virus-specific CTL responses, and delays virus clearance. Therefore, the H. pylori urease-mediated immunoregulation in the switch from JNK(+) Th1 to JNK(-) Th2 phenotype, and the preceding low IL-12 response, are likely critical steps in the impairment of antiviral immunity.
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PMID:Impaired development of HIV-1 gp160-specific CD8(+) cytotoxic T cells by a delayed switch from Th1 to Th2 cytokine phenotype in mice with Helicobacter pylori infection. 1118 Jan 17

Cryptococcus neoformans is a pathogenic fungus that causes life-threatening meningoencephalitis in immunocompromised patients (HIV-positive patients), and lymphoproliferative disorders in patients subjected to organ transplantation and other immunosuppressive therapies. This fungus is commonly found in soil and avian excreta, mainly from pigeon and turkey. We describe the isolation and characterization of 17 clinical and 10 environmental (pigeon excreta) isolates from the Brazilian state Rio Grande do Sul. We analyzed capsule formation, carbon assimilation pattern, canavanine-glycine-bromothymol blue (CGB) reaction, and nitrate and urease tests, as well as susceptibility to antifungal drugs. The genetic variability among C. neoformans isolates was studied using randomly amplified polymorphic DNA (RAPD) analysis. Eight of 22 arbitrary polymerase chain reaction primers used confirmed genetic polymorphism among the environmental isolates tested, suggesting that it remains feasible to use RAPD analysis as a typing method. Three of the selected primers yielded 10 molecular subclasses. The majority of the clinical isolates were assigned to the molecular subclass F. The RAPD data obtained reinforce the developing consensus about the population structure of this fungus.
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PMID:Epidemiological aspects of clinical and environmental Cryptococcus neoformans isolates in the Brazilian state Rio Grande do Sul. 1252 Nov 20

A strain of Histoplasma capsulatum var. duboisii (deposited as IFM 50954 in Chiba University) was isolated from the cerebrospinal fluid of a female Ugandan patient infected with HIV. The isolate had in vitro urease activity on Christensen's urea agar slants, although the common belief is that H. capsulatum var. duboisii is urease negative, and is, considered one of the characteristic markers that distinguishes the three varieties of H. capsulatum. Forty H. capsulatum var. capsulatum, five H. capsulatum var. duboisii, and five H. capsulatum var. farciminosum isolates were evaluated for urease activity on Christensen's urea agar slants and for other qualitative and quantitative urease assays of activity. All 50 isolates of H. capsulatum used in this study were positive for urease activity, suggesting that urease activity may be universal characteristic of H. capsulatum. We also compared the urease activity and pathogenicity of seven H. capsulatum isolates that convert into yeast-form cells. Although isolate IFM 50954 showed moderate virulence in mice and moderate urease activity among tested H. capsulatum isolates, there was no correlation between level of urease activity and pathogenicity. In addition, scanning electron microscopy revealed that some microconidia of isolate IFM 50954 formed "double-cell" configurations that were attached to each other by narrow bases.
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PMID:Histoplasma capsulatum variety duboisii isolated in Japan from an HIV-infected Ugandan patient. 1461 97

A 53-year-old, male patient presented with pain in the middle area of the back of his left foot. The painful area was associated with a reddish dome-shaped swelling of 24 by 18 mm which had ulcerated in the center part. Histopathologically, the cutaneous lesion consisted of an ulcer surrounded by abscess and granuloma and numerous acid-fast organisms were observed. Subsequently, the area just below the left inguinal area developed redness and swelling approaching the size of a quail egg. The patient responded favorably with rifampicin, levofloxacin, and minocycline therapy. The patient was immunodeficient, but negative for HIV-1 and HIV-2 antibodies and the etiology of his immunodeficient state is unclear. Skin tissues or pus were cultured at 37 degrees C on 2% Ogawa and BBL MGIT. Acid-fast organisms were recovered on MGIT within 4 to 12 days, while 2% Ogawa medium failed to recover acid-fast bacteria. Using growth from the positive MGIT tube as inoculum, MycoBroth, 7H9 broth, 7H11.2% Ogawa supplemented with or without iron complexes, and blood agar were inoculated and cultured at 30 and 37 degrees C. Growth at 30 and 37 degrees C was seen with MycoBroth, 7H9, hemin (60 microM) or ferric ammonium citrate (15 mg/ml) supplemented 7H11 and blood agar as well as 7H11 supplemented with factor X. Growth at 30 degrees C only was observed for ferric ammonium citrate supplemented 7H9 and 2% Ogawa. Generally, growth at 30 degrees C was better than that at 37 degrees C in all media. No growth at either temperature was observed with hemin or factor X supplemented 2% Ogawa. With respect to the biochemical characterization, the isolate was negative for niacin, nitrate reduction, urease, arylsulfatase, Tween 80 hydrolysis, catalase, 68 degrees C catalase, acid phosphatase, and tellurite reduction, while strongly positive for neutral red test. Sequencing of the 16S rRNA gene showed the isolate to be consistent with Mycobacterium haemophilum. Based on the composite characterization, the isolate was identified as M. haemophilum. This is the second case report of M. haemophilum infection in Japan in the literature.
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PMID:[Bacteriological features of Mycobacterium haemophilum isolated from skin lesions in an immunodeficient patient]. 1521 60

The prevalence of H. pylori infection in AIDS patients has been controversial. A. controlled prospective and descriptive study was conducted in a group of 64 HIV-infested patients. H. pylori detection was carried out by endoscopic study during which two biopsy samples of gastric antrum and body were taken for the histologic study and other 2 samples of gastric antrum and body for urease testing. H.pylori infection prevalence was 56.3%. The comparison group was composed by 110 serologically HIV-negative patients, with an infection prevalence rate of 77.2%. In the HIV-AIDS group, the frequency of gastric ulcer was 1,5% and no duodenal ulcer was found whereas the comparison group showed a frequency of gastric and duodenal ulcers of 1.8 and 15.5% respectively. HIV+/AIDS patients in category I exhibited an H. pylori infection prevalence of 68.7%, category II, 39.2% and category III, 21,0%. A reversed association was observed between the level of immune deterioration and the prevalence of H. pylori infection.
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PMID:[Helicobacter pylori infection in a group of HIV/AIDS patients]. 1584 24

By immunizing ground-state peptides or proteins, we can produce super catalytic antibodies possessing serine protease-like characteristics. The unique feature of super catalytic antibodies is their ability to decompose a target molecule that is being killed. The authors have succeeded in preparing super catalytic antibodies that destroy (i) the HIV-1 envelope protein gp41, (ii) chemokine receptor CCR5 peptide, and (iii) Helicobacter pylori urease, etc. Some of them can degrade antigens at high catalytic reaction rates. Regarding their Km and kcat, super catalytic antibodies show intermediary values between that of enzymes (high Km and kcat) and that of antibodies (low Km and kcat [=0]). The catalytic function of an antibody mostly resides in its light chain. From mouse Vkappa germline analysis, it became clear that super catalytic antibodies are generated from some discrete germlines such as bb1, cr1, cs1, bl1, bj2 and bd2. In these Vkappa germlines, at least one catalytic triad composed of three amino acid residues, namely, Asp1, Ser27a and His93, is encoded. Namely, the antibody light chains (super catalytic antibodies) generated from the germlines are inherently able to enzymatically decompose antigens. Thus, such antibody light chains can be referred to as antigenase (antigen-decomposing enzyme) and may have arisen during the evolution of antibodies to acquire a higher ability than that of enzymes for developing a sophisticated self-defense system for survival.
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PMID:Super catalytic antibody and antigenase. 1623 7

HIV infection leads to progressive deterioration of immunity. Upper gastrointestinal symptoms are often reported in patients with this infection. The aim of the study was to evaluate morphological changes in upper gastrointestinal tract mucosa and prevalence of opportunistic infections and Helicobacter pylori in HIV-infected people in relationship to the degree of immunosupression. We studied 94 HIV-infected patients with dyspeptic symptoms, 47 suffered from severe immunodeficiency expressed by low CD4+ lymphocyte count below 200/ mm3. Control group consisted of 52 non HIV-infected patients. During endoscopy, gastrointestinal tract mucosa was evaluated and biopsy samples were taken from gastric body and antrum for histopathological analysis and rapid urease test. In patients with CD4+ lymphocyte count below 200/mm3, endoscopic examination revealed significantly more frequent esophageal candidiasis (36%); whereas reflux esophagitis (13%) was significantly less often diagnosed in comparison to the rest of the patients. Duodenitis and duodenal erosions were also less frequent in them. Prevalence of Helicobacter pylori infection in gastric antrum was significantly lower in HIV-infected patients with severe immunodeficiency (40%) in comparison to the rest of the patients (72%) and control group (69%). Chronic active gastritis of the antral mucosa was less frequent in HIV-infected patients with CD4+ lymphocyte count below 200/mm3.
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PMID:[Studies on relationship between immunodeficiency in HIV-infected people and condition of upper gastrointestinal tract mucosa, prevalence of mycosis and Helicobacter pylori infection]. 1678 59

The chemical constituents of some species of Euphorbia, which grow mostly in semi-desert areas in Iran and on the Alborz Mountains in the north of Tehran, have been found to include chemotaxonomically important myrsinane diterpenoids and cycloartane triterpenoids. The Euphorbia plants collected in province of Azarbaijan in the northwestern part of Iran contained mostly derivatives of skin-irritating ingenol esters. Some of the diterpenoids with myrsinane carbon skeleton inhibited enzymes such as alpha-glycosidase, urease, HIV-1 reverse transcriptase, and prolyl endopeptidase. They also showed analgesic and DNA-damaging activities. The present review describes the chemistry and biological activity of several compounds isolated from different species of Iranian Euphorbia: diterpenoids with myrsinane skeletons, flavonoids, tannins, alkanes, sterols, mono-, sesqui- and triterpenoids, skin-irritating and tumor-promoting latexes and their active ingenol diterpenoids.
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PMID:Chemistry and biological activity of secondary metabolites in Euphorbia from Iran. 1688 6

Forty-five mycobacterial strains isolated from 23 Colombian HIV-positive patients were identified as members of the Mycobacterium avium complex (MAC) and were characterized using different molecular approaches. Seven of the isolates showed characteristic features that allowed them to be differentiated from other members of the complex. The isolates had a novel 16S-23S rRNA internal transcribed spacer (ITS 1) gene sequence which is described as a new sequevar, MAC-X. All of the seven novel isolates gave a positive result with the MAC-specific AccuProbe (Gen-Probe), but tested negative for Mycobacterium avium and Mycobacterium intracellulare species-specific probes (64 and 100 % of the isolates, respectively). The novel isolates could be differentiated phenotypically from other members of the MAC on the basis of the production of urease and by a consistent mycolic acid pattern. The novel isolates shared some characteristics with M. avium, such as the avium variant I (av-I) pattern of the hsp65 gene as determined by PCR restriction analysis and a positive PCR result for the mig (macrophage-induced) gene. However, the novel isolates showed a unique 16S rRNA gene sequence. DNA-DNA relatedness values, from 24 to 44 %, confirmed the distinction of the novel isolates from other members of the MAC at the genetic level and their status as members of a separate species. The novel isolates are proposed as representatives of a novel species, Mycobacterium colombiense sp. nov., that is closely related to M. avium within the MAC. The type strain is 10B(T) (=CIP 108962(T)=CECT 3035(T)).
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PMID:Mycobacterium colombiense sp. nov., a novel member of the Mycobacterium avium complex and description of MAC-X as a new ITS genetic variant. 1695 98


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