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)

Cyclo(His-Pro) (CHP) is a gut-neuropeptide that influences both appetite and carbohydrate metabolism. This study was undertaken to determine whether concentrations of CHP correlated with various clinical markers of nutritional status and progression of HIV infection. Serum concentrations of CHP were analyzed in a clinical sample of 100 HIV-positive patients whose HIV clinical status ranged from asymptomatic to advanced disease with weight loss. We found a relationship between CHP concentrations and serum albumin and hemoglobin levels, markers of chronic nutrition and disease. However, no correlation was seen between CHP and cortisol concentrations, a marker of acute stress. To analyze the relationship of HIV clinical stage and CHP, patients were divided into three subgroups: asymptomatic, mildly symptomatic, and clear-cut AIDS. CHP concentrations were significantly correlated with HIV clinical stage. These data lead to the hypothesis that CHP is a marker of disease progression and that it potentially plays a role in modulating the nutrition of HIV-infected patients.
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PMID:Relationship between serum cyclo(His-Pro) concentrations and the nutritional status of HIV-infected patients. 813 57

Association of the human immunodeficiency virus type 1 (HIV-1) gag polyprotein precursor with cellular membranes is necessary for assembly of virions. We used in vitro synthesized HIV-1 gag to study its association with isolated cellular membranes. Rabbit reticulocyte lysates programmed with HIV-1 gag mRNA incorporated [35S]methionine and [3H]myristate into two predominant species of 55 kDa and 40 kDa. Radioimmunoprecipitation with HIV-1-specific antibodies suggested that the 55-kDa protein represented the polyprotein precursor (Pr55gag), while the 40-kDa protein was a mixture of N- or C-terminal truncations of the gag precursor. The Pr55gag protein bound to cellular membranes, while the 40-kDa mixed protein species did not. Membrane binding studies with C terminus-truncated and point mutants revealed that the seven-amino acid sequence located between the two Cys-His arrays in the nucleocapsid region was necessary for stable association to occur. Therefore, we propose that signals in addition to myristate are required for the membrane association of HIV-1 gag proteins and that these signals include a domain in the nucleocapsid protein.
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PMID:Characterization of human immunodeficiency virus type 1 Pr55gag membrane association in a cell-free system: requirement for a C-terminal domain. 818 54

The microsporidian Enterocytozoon bieneusi has been recognized as an important cause of chronic diarrhea in severely immunodeficient adults infected with human immunodeficiency virus (HIV). We report the first case of intestinal E. bieneusi infection in a child. The 9-year-old boy with connatal HIV infection presented with failure to thrive, chronic diarrhea, and intermittent abdominal pain. His CD4 lymphocyte count was 0.05 x 10(9)/L and dropped to 0.01 x 10(9)/L. No HIV-associated opportunistic infection other than oral hairy leukoplakia and oral candidiasis had been found before microsporidia were detected. Treatment of microsporidiosis with albendazole was of no benefit. During follow-up, the boy also developed intestinal cryptosporidiosis. Evaluation of chronic diarrhea in severely immunodeficient HIV-infected children should include examination for intestinal microsporidia. We recommend the use of a new coprodiagnostic technique that allows detection of microsporidial spores in stool specimens. Furthermore, consideration of dual or even multiple parasitic infections in the differential diagnosis of chronic diarrhea may have both important clinical and epidemiological implications.
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PMID:Intestinal coinfection with Enterocytozoon bieneusi and Cryptosporidium in a human immunodeficiency virus-infected child with chronic diarrhea. 821 93

A 38-year-old man, HIV-positive for 6 years, developed fever and cough with deterioration in his general state. Chest radiography demonstrated an infiltration in the left upper lobe and computed tomography showed a septated cavity. Three bronchioalveolar lavages over 4 weeks recovered Klebsiella, Candida, Pseudomonas and Staphylococcus in the lavage fluid. Acid-fast rods were not found in any of the microscopic preparations. His clinical condition and the radiological findings deteriorated despite appropriate antibiotic administration. A further cavity occurred in the right upper lobe and the inflammatory infiltrations extended further. Although no acid-fast organism had been demonstrated, tuberculostatic treatment was begun (daily 300 mg isoniazid, 600 mg rifampicin, 900 mg streptomycin, 2 g pyrazinamide). His general condition and the radiological findings rapidly improved. Four weeks after culturing the lavage fluid atypical Mycobacterium xenopi was isolated. This case illustrates the difficulty of diagnosing an atypical mycobacterial infection. It takes time and effort, but it is of great importance because up to 50% of patients with AIDS contract such infection. Early and appropriate treatment will significantly improve quality of life and life expectancy.
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PMID:[Pneumonia due to a rare atypical Mycobacterium in AIDS]. 822 23

Packaging of retroviral genomic RNA during virion assembly is thought to be mediated by specific interactions between the gag polyprotein and RNA sequences (often termed the psi or E region) near the 5' end of the genome. For many retroviruses, including human immunodeficiency virus type 1 (HIV-1), the portions of the gag protein and the RNA that are required for this interaction remain poorly defined. We have used an RNA gel mobility shift assay to measure the in vitro binding of purified glutathione S-transferase-HIV-1 gag fusion proteins to RNA riboprobes. Both the complete gag polyprotein and the nucleocapsid (NC) protein alone were found to bind specifically to an HIV-1 riboprobe. Either Cys-His box of NC could be removed without eliminating specific binding to the psi riboprobe, but portions of gag containing only the MA and CA proteins without NC did not bind to RNA. There were at least two binding sites in HIV-1 genomic RNA that bound to the gag polyprotein: one entirely 5' to gag and one entirely within gag. The HIV-1 NC protein bound to riboprobes containing other retroviral psi sequences almost as well as to the HIV-1 psi riboprobe.
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PMID:Specific binding of human immunodeficiency virus type 1 gag polyprotein and nucleocapsid protein to viral RNAs detected by RNA mobility shift assays. 823 Apr 41

The sequence of 8734 nucleotides (nt) from the 5'-end of the beet yellows closterovirus (BYV) RNA was determined to complete the 15,480-nt sequence of the virus genome. The 5'-terminal two-thirds of the sequence are occupied by two overlapping open reading frames (ORFs) 1a and 1b, encoding products with calculated M(r) of 295K and 48K, respectively. The RNA sequence surrounding the stop codon in ORF 1a shows structural elements typical of ribosomal frameshifting signals in a number of animal and plant viruses. It is predicted that the ORF 1b product is expressed via a +1 ribosomal frameshifting as the 348K ORF 1a/1b fusion protein. This putative protein contains the array of methyltransferase, RNA helicase, and RNA-dependent RNA polymerase domains that is conserved in the Sindbis-like supergroup of positive-strand RNA viruses. The 348K protein of BYV is longer than the putative replicases of the most closely related viruses (tobra- and tobamoviruses) by about 1300 amino acids distributed between two unique regions, one at the N-terminus, and the other in the central portion. The N-terminal domain showed sequence similarity to the helper component papain-like protease of potyviruses. By using in vitro translation of the T7 transcripts encoding the N-terminal 92K peptide of the BYV ORF 1a product, we found that the N-terminal fragment of 588 amino acids is released from the translation product by cleavage at the Gly-Gly dipeptide. Site-directed mutagenesis of either of the predicted catalytic residues Cys-509 and His-569 or of the Gly-588 at the cleavage site completely abolished the cleavage. The central unique region of the 348K protein contains a domain distantly resembling the aspartic protease of HIV and other lentiviruses. As shown previously, the 3'-terminal portion of the BYV genome encompasses seven more ORFs, one of which codes for a protein related to the HSP70 cell heat shock proteins, whereas two others encode the capsid protein and its diverged copy. Thus, despite the apparent evolutionary relationship with Sindbis-like viruses, BYV comprises a collection of genomic modules absorbed from different sources and has a unique expression strategy.
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PMID:Beet yellows closterovirus: complete genome structure and identification of a leader papain-like thiol protease. 825 66

The V3 loop of the HIV (human immunodeficiency virus)-1 envelope glycoprotein gp120 likely plays a role in HIV-1 infectivity. Although the amino acid sequence of the V3 loop is hypervariable, it contains a conserved region, Gly-Pro-Gly-Arg, that shows similarity to the active-site Gly-Pro-Cys-Arg sequence of inter-alpha-trypsin and trypstatin proteinase inhibitors. The purpose of the present work was to identify proteinases recognizing substrates with basic amino acids in the P1 substrate site that are present in MOLT-4 cells, a human CD4-positive T helper lymphocyte cell line, and to characterize these enzymes in terms of substrate, pH and ionic-strength preferences, size and susceptibility to various inhibitors, including 24- and 36-amino-acid-long V3 loop peptides. Extraction of MOLT-4 cells at low ionic strength solubilized nearly all of the trypsin-like activity, which was separable into five peaks of activity by chromatography on Mono-Q: Peaks 1, 2a, 2b, 3 and 4. All showed a neutral pH optimum, and all except Peak 4 showed optimal activity at high ionic strength. Peak 1 preferred Tos-Gly-Pro-Arg, p-nitroanilide (-pNA) substrate; Peaks 2-4 preferred benzyloxycarbonyl-Val-Leu-Gly-Arg-pNA. Peak 1, a zinc-dependent enzyme with serine and histidine in the active site, exhibited an M(r) of 75,000 on Superose 12 and was poorly inhibited by V3 loop peptides. Peak 2 contained two overlapping peaks, called 2a and 2b, that exhibited properties of zinc-dependent metalloproteinases. Gel filtration of Peak 2 activities revealed a major peak of activity at 81 kDa and a shoulder centred at 240 kDa. Each was modestly inhibited by V3 loop peptides. Peak 3, a zinc-dependent proteinase, exhibited a molecular mass of 100 kDa by gel filtration and was particularly sensitive to inhibition by V3 loop peptides. Peak 4 exhibited a molecular mass of 1100 kDa by gel filtration and was not inhibited by V3 loop peptides. None of these enzymes could be classified as mast-cell tryptase, and material in MOLT-4 cells cross-reactive with anti-(human tryptase) antibodies was not detected. Whether any of the MOLT-4 proteinases described in this study play a role in HIV-1 infectivity remains to be examined.
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PMID:Separation and partial characterization of proteinases with substrate specificity for basic amino acids from human MOLT-4 T lymphocytes: identification of those inhibited by variable-loop-V3 peptides of HIV-1 (human immunodeficiency virus-1) envelope glycoprotein. 831 3

A 24-year-old male homosexual drug addict was admitted in coma and circulatory failure after a 10 g overdose of acebutolol. The usual resuscitative measures were undertaken, together with administration of adrenaline and gastric lavage. Six hours of external cardiac massage and pacing, and high catecholamine doses (36 mg.h-1 of adrenaline and 60 micrograms.kg-1 x min-1 of dobutamine) were required before the circulatory system became again spontaneously efficient. After this acute episode, the patient improved despite acute tubular necrosis. On the third day, bilateral alveolar and interstitial lesions were found on the chest film. Bronchoalveolar lavage and protected distal brushings were carried out. Both Aeromonas hydrophila and Staphylococcus aureus were found in the cultured brushings. Treatment with ceftriaxone, vancomycin and amikacin was introduced. This nosocomial pneumonia was very haemorrhagic, resulting in several bloody casts responsible for several episodes of atelectasis. The patient was definitely extubated on the 18th day, and left the ICU 23 days later without any sequela. His HIV status was negative. Four other infections with the same strain of Aeromonas hydrophila occurred at the same time as this patient's. The common source for this germ was found to be soft water. Several measures have since been undertaken: removal of a centralized water softener, filtration and higher chlorine content in the water circuit, and updating of intensive care protocols for disinfection of equipment.
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PMID:[Nosocomial Aeromonas hydrophila pneumonia complicating toxic coma]. 833 70

The human immunodeficiency virus type 1 (HIV-1) nucleocapsid protein contains two copies of a sequence motif, the cysteine-histidine box, that is conserved among retroviruses. To identify the functionally relevant positions of a cysteine-histidine box, each amino acid in the proximal copy of the motif was individually substituted by site-directed mutagenesis. Mutations at 5 of 14 positions abolished virus replication and reduced the viral RNA content of mutant particles to between 10 and 20% of parental levels. Mutations at other positions had either no or only a minor effect on virus replication and virion RNA content. In vitro binding of RNA to bacterially expressed mutant Pr55gag polyprotein correlated well with the effects of the mutations on particle-associated viral RNA levels. The two different copies of the motif in the HIV-1 nucleocapsid protein are not functionally equivalent, since the conversion of the proximal motif to an exact copy of the distal motif results in a defect in virus replication and a reduction in the viral RNA content of mutant particles. The simultaneous substitution of functionally relevant positions in both motifs led to a significant decline in gag protein export, indicating that the nucleocapsid domain of the gag precursor is also required for efficient assembly or release of the virion.
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PMID:Mapping of functionally important residues of a cysteine-histidine box in the human immunodeficiency virus type 1 nucleocapsid protein. 837 56

In order to study the relationship between virus populations in a human immunodeficiency virus type 1 (HIV-1)-infected mother and her infant, we analysed a 276 bp fragment, including the V3 region, of genomic HIV-1 RNA purified from serum. Samples were collected from the mother 6, 4 and 2 months prior to delivery, during delivery and 10 months after childbirth (samples MA to ME, respectively) and from the infant at birth (cord blood) and the ages of 6 weeks and 9 months. A heterogeneous sequence population was observed in the maternal samples (mean nucleotide variation of 2.4 to 4.2%, range 0 to 8.3%). Until the age of 6 weeks the sequence population in the infant was highly homogeneous (mean nucleotide variation < or = 0.7%, range 0 to 2.5%). At 9 months of age, the infant's virus population showed more heterogeneity (mean nucleotide variation of 1.8%, range 0.4 to 3.6%) and a drift in the consensus sequence was observed. The evolution of the V3 region in the mother was characterized by accumulation of amino acid substitutions diverging from the virus population observed in the infant. The mean nucleotide distance between the maternal sequence populations and the sequence population of the child at birth was 2.8, 2.6, 3.7, 5.2 and 5.3% for the samples MA, MB, MC, MD and ME, respectively. Nearly complete replacement at position 308, previously described as antigenically important, from a proline to a histidine was observed during pregnancy, whereas all clones of the child's virus at birth and at 6 weeks contained a proline at that position. In conclusion, intra-uterine transmission is associated with a homogeneous sequence population in the child at birth, which is more closely related to the sequence population present in the mother during the first and second trimester of pregnancy than to the sequence population at delivery.
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PMID:Genomic human immunodeficiency virus type 1 RNA variation in mother and child following intra-uterine virus transmission. 837 56


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