Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to assess the microbial water quality in canal waters throughout the Florida Keys, a survey was conducted to determine the concentration of microbial fecal indicators and the presence of human pathogenic microorganisms. A total of 19 sites, including 17 canal sites and 2 nearshore water sites, were assayed for total coliforms, fecal coliforms, Escherichia coli, Clostridium perfringens, enterococci, coliphages, F-specific (F(+)) RNA coliphages, Giardia lamblia, Cryptosporidium parvum, and human enteric viruses (polioviruses, coxsackie A and B viruses, echoviruses, hepatitis A viruses, Norwalk viruses, and small round-structured viruses). Numbers of coliforms ranged from <1 to 1, 410, E. coli organisms from <1 to 130, Clostridium spp. from <1 to 520, and enterococci from <1 to 800 CFU/100 ml of sample. Two sites were positive for coliphages, but no F(+) phages were identified. The sites were ranked according to microbial water quality and compared to various water quality standards and guidelines. Seventy-nine percent of the sites were positive for the presence of enteroviruses by reverse transcriptase PCR (polioviruses, coxsackie A and B viruses, and echoviruses). Sixty-three percent of the sites were positive for the presence of hepatitis A viruses. Ten percent of the sites were positive for the presence of Norwalk viruses. Ninety-five percent of the sites were positive for at least one of the virus groups. These results indicate that the canals and nearshore waters throughout the Florida Keys are being impacted by human fecal material carrying human enteric viruses through current wastewater treatment strategies such as septic tanks. Exposure to canal waters through recreation and work may be contributing to human health risks.
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PMID:Detection of viral pathogens by reverse transcriptase PCR and of microbial indicators by standard methods in the canals of the Florida Keys. 1047 24

Aquaporins are a family of homologous membrane proteins that function as highly selective water channels. Aquaporin-5 (AQP5) is uniquely present in lacrimal and salivary glands, where it accounts for normal tear and saliva production. We tested the hypothesis that orally administered human interferon-alpha (HuIFN-alpha) benefits persons with xerostomia by augmenting the production of AQP5 protein by parotid gland epithelium. Cells from three human parotid glands were cultured with and without human lymphoblastoid IFN-alpha, and assayed for AQP5 mRNA levels by reverse transcriptase polymerase chain reaction (RT-PCR), and AQP5 protein levels by Western blot. Intracellular localization of AQP5 protein was done using confocal microscopy. The functional integrity of the glandular tissue was confirmed by RT-PCR analysis of alpha-amylase 1 and basic proline-rich protein transcripts. AQP5 was constitutively expressed in human parotid gland tissue, with AQP5 protein restricted to the plasma membranes and cytoplasmic vesicles of acinar cells. IFN-alpha augmented AQP5 transcription and protein production in a concentration-dependent manner, and increased the size of intensity of staining of AQP5-containing cytoplasmic vesicles in acinar cells. We conclude that IFN-alpha upregulates AQP5 gene expression in human parotid acinar cells in vitro. To our knowledge, this is the first demonstration that IFN-alpha regulates the gene expression of an aquaporin.
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PMID:Interferon-alpha upregulates gene expression of aquaporin-5 in human parotid glands. 1047 40

A rapid, semiquantitative reverse transcriptase-polymerase chain reaction assay was developed to investigate signal transduction events involved in the induction of Crassulacean acid metabolism (CAM) in detached common ice plant (Mesembryanthemum crystallinum) leaves. Transcript abundance of Ppc1, a gene encoding the CAM-specific isoform of phosphoenolpyruvate carboxylase, increased rapidly in response to osmotic stress (dehydration and mannitol), ionic stress (NaCl), and exogenous abscisic acid treatment, but failed to accumulate in response to exogenous cytokinin or methyl jasmonate. Stress-induced accumulation of Ppc1, GapC1, and Mdh1 transcripts was inhibited by pretreating leaves with the calcium chelator ethyleneglycol-bis(aminoethyl ether)-N,N'-tetraacetic acid, suggesting that extracellular calcium participates in signaling events leading to CAM induction. Treatment of unstressed detached leaves with ionomycin, a Ca(2+) ionophore, and thapsigargin, a Ca(2+)-ATPase inhibitor, enhanced Ppc1 transcript accumulation, indicating that elevations in cytosolic [Ca(2+)] are likely to participate in signaling CAM induction. Inhibitors of Ca(2+)- or calmodulin-dependent protein kinases (N-[6-aminohexyl]-5-chloro-1-napthalenesulfonamide, Lavendustin C) and protein phosphatase 1 and 2A (okadaic acid) activity suppressed Ppc1 transcript accumulation in response to ionic and osmotic stresses, as well as abscisic acid treatment. These results suggest that both protein phosphorylation and dephosphorylation events participate in signaling during CAM induction. In contrast, pretreatment with cyclosporin A or ascomycin, inhibitors of protein phosphatase 2B activity, stimulated Ppc1 gene expression either directly or indirectly through promoting water loss.
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PMID:Signaling events leading to crassulacean acid metabolism induction in the common ice plant 1051 46

The elimination of human viruses, phages, bacteria and Cryptosporidium oocysts by a new generation commercial Aquaguard purifier for the domestic treatment of drinking water, has been evaluated. The unit basically consists of a candle prefilter, activated carbon filter and ultraviolet irradiation compartment. Drinking water seeded with selected laboratory test strains of resistant micro-organisms was passed through the unit. Similar tests were carried out with sewage-contaminated river water and secondary treated waste water containing naturally occurring organisms. Test procedures were based on internationally accepted principles for the evaluation of point-of-use water treatment units, including a standard test protocol of the United States Environmental Protection Agency. Reduction in numbers of seeded test organisms at several log levels higher than those expected in water for which the unit is intended, was determined by the cultivation of viable organisms. In the case of seeded viruses and Cryptosporidium parvum oocysts the qualitative absence of nucleic acid was determined by the reverse transcriptase polymerase chain reaction (RT-PCR). At the design flow rate of one litre per minute, numbers of polio, hepatitis A, adeno types 2 and 41, rota SA11, human rota and astro viruses, as well as somatic and MS2 coliphages, and Escherichia coli, Streptococcus faecalis, Clostridium perfringens, total coliform bacteria, enterococci, heterotrophic bacteria and C. parvum oocysts, were reduced by more than 99.999% in all waters tested. This efficiency conforms to specifications for such units. The quality of the treated water was well within microbiological limits of international specifications for drinking water.
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PMID:Elimination of viruses, phages, bacteria and Cryptosporidium by a new generation Aquaguard point-of-use water treatment unit. 1054 30

An apparently healthy 7-year-old boy attempted to demonstrate his ability to dive into a whirlpool but was retrieved from the water in a state of unconsciousness after several minutes. Resuscitation was unsuccessful. No characteristic signs of drowning were found at the autopsy but examination of the lymph nodes and the cardiac muscle indicated a pre-existent infection. The histological examination revealed a slight degree of predominantly lymphocytic infiltration of the cardiac muscle. IgM antibodies against Coxsackie virus were detected in the serum sample by means of ELISA. The reverse transcriptase polymerase chain reaction (RT-PCR) performed on an extract of formalin-fixed, paraffin-embedded cardiac muscle tissue revealed a DNA sequence specific for Coxsackie B3 virus. Therefore, cardiac failure was due to a myocardial virus infection and the additional strain caused by diving. This case report emphasizes the importance of modern molecular biological methods in cases of sudden death including death by hydrocution.
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PMID:Hydrocution in a case of Coxsackie virus infection. 1055 May 96

Nuclear receptors which interact with the retinoid X receptor are involved in the regulation of epidermal differentiation and development. We have recently shown that activators of the peroxisome proliferator-activated receptor and of the farnesoid X-activated receptor accelerate epidermal barrier maturation in fetal rat skin in vitro. In this study we asked whether cutaneous development in utero was affected by peroxisome proliferator-activated receptor or farnesoid X-activated receptor activators, or by an activator of another retinoid X receptor partner, liver X receptor. Activators of the peroxisome proliferator-activated receptor (clofibrate or linoleic acid), farnesoid X-activated receptor (farnesol or juvenile hormone III), or liver X receptor (22R-hydroxycholesterol), were injected into the amniotic fluid of fetal rats on gestational day 17. Fetal epidermal barrier function and morphology was assessed on day 19. Whereas vehicle-treated fetal rats displayed no measurable barrier (transepidermal water loss > 10 mg per cm2 per h), a measurable barrier was induced by the intra-amniotic administration of all activators tested (transepidermal water loss range 4.0-8.5 mg per cm2 per h). By light microscopy, control pups lacked a well-defined stratum corneum, whereas a distinct stratum corneum and a thickened stratum granulosum were present in treated pups. By electron microscopy, the extracellular spaces of the stratum corneum in control pups revealed a paucity of mature lamellar unit structures, whereas these structures filled the stratum corneum interstices in treated pups. Additionally, protein and mRNA levels of loricrin and filaggrin, two structural proteins of stratum corneum, were increased in treated epidermis, as were the activities of two lipid catabolic enzymes critical to stratum corneum function, beta-glucocerebrosidase and steroid sulfatase. Finally, peroxisome proliferator-activated receptor-alpha and -delta and liver X receptor-alpha and -beta mRNAs were detected in fetal epidermis by reverse transcriptase-polymerase chain reaction and northern analyses. The presence of these receptors and the ability of their activators to stimulate epidermal barrier and stratum corneum development suggest a physiologic role for peroxisome proliferator-activated receptor and liver X receptor and their endogenous ligands in the regulation of cutaneous development.
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PMID:Fetal epidermal differentiation and barrier development In vivo is accelerated by nuclear hormone receptor activators. 1057 35

In this study, Norwalk-like virus (NLV) RNA was detected by reverse transcriptase PCR (RT-PCR) in sewage water concentrates. Sequence analysis of the RT-PCR products revealed identical sequences in stools of patients and related sewage samples. In 6 of 11 outbreak-unrelated follow-up samples, multiple NLV genotypes were present. Levels as high as 10(7) RNA-containing particles per liter were found. These data show that high loads of NLVs may be present in sewage and warrant further studies addressing the efficacy of NLV removal by sewage water treatment processes.
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PMID:Molecular detection of Norwalk-like caliciviruses in sewage. 1058 31

Designing altered peptide ligands to generate specific immunological reactivity when bound to class I major histocompatibility complexes is important for both therapeutic and prophylactic reasons. We have previously shown that two altered peptides, derived from human immunodeficiency virus (HIV)-reverse transcriptase (RT) residues 309-317, are more immunogenic in vitro than the wild-type peptide. One peptide variant, I1Y, was able to stimulate RT-specific cytotoxic T cells from the blood of three HIV-infected individuals better than the wild-type RT peptide. Both I1Y and I1F peptide variants increase the cell surface half-life of the peptide-class I complex approximately 3-fold over that of the RT peptide but have different immunological activities. These peptides are candidates for the design of vaccines for HIV due to their increased immunogenicity. To understand the basis for the increased cell surface stability compared with wild-type peptide and to understand the differences in T cell recognition between I1Y and I1F, we determined the x-ray crystal structures of the two class I MHC-peptide complexes. These structures indicate that the increased cell surface half-life is due to pi-pi stacking interactions between Trp-167 of HLA-A2.1 and the aromatic P1 residues of I1F and I1Y. Comparison of the structures and modeling potential T cell receptor (TCR) interactions suggests that T cell interactions and immunogenicity are different between I1Y and I1F for two reasons. First, subtle changes in the steric and polar properties of the I1Y peptide affect TCR engagement. Second, water-mediated hydrogen bond interactions between the P1-Tyr and the P4-Glu peptide residues increase peptide side chain rigidity of residues critical for TCR engagement.
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PMID:The structural basis for the increased immunogenicity of two HIV-reverse transcriptase peptide variant/class I major histocompatibility complexes. 1060 Dec 90

We investigated the in vitro effect of the water-soluble, highly stable thalidomide analogue CC-3052 on HIV-1 expression and TNF-alpha production in latently infected promonocytic U1 cells, acutely infected T cells and monocyte-derived human macrophages (MDM), and in mitogen-stimulated ex vivo cultures from patients with primary acute HIV-1 infection. HIV-1 expression was assessed by Northern blot analysis of RNAs, and ELISA for p24 antigen release and reverse transcriptase (RT) activity. TNF-alpha expression was evaluated by RT-polymerase chain reaction (PCR)-ELISA for mRNA and ELISA for protein secretion. We demonstrated that CC-3052 is able to inhibit HIV-1 expression, as evaluated by mRNA, p24 release and RT activity, in phorbol myristate acetate (PMA)- and cytokine-stimulated U1 cells. Furthermore, CC-3052 inhibited HIV-1 expression, as evaluated by p24 and RT activity, in acutely infected MDM and T cells. As far as TNF-alpha is concerned, CC-3052 significantly reduced TNF-alpha mRNA and protein secretion in PMA-stimulated U937 and U1 cells, and in PMA-stimulated uninfected and acutely infected MDM. Consistently, the addition of CC-3052 reduced TNF-alpha production in phytohaemagglutinin (PHA) and lipopolysaccharide (LPS)-stimulated whole blood cultures from patients during the primary acute phase of HIV-1 infection. Since TNF-alpha is among the most potent enhancers of HIV-1 expression, the effect of CC-3052 on TNF-alpha may account for its inhibitory activity on HIV-1 expression. Given the well documented immunopathological role of TNF-alpha and its correlation with viral load, advanced disease and poor prognosis, CC-3052 could be an interesting drug for the design of therapeutic strategies in association with anti-retroviral agents.
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PMID:The thalidomide analogue CC-3052 inhibits HIV-1 and tumour necrosis factor-alpha (TNF-alpha) expression in acutely and chronically infected cells in vitro. 1060 73

Calbindin D28k has been reported to be involved in the transcellular calcium transport along the rat distal tubule. It has also been shown that chronic metabolic acidosis (CMA) induces significant hypercalciuria. The present study investigated whether CMA affects the mRNA and the protein expression of calbindin D28k along isolated distal tubule (DT) of rats. The animals were made acidotic by adding 0.28 mol/L NH4Cl to the drinking water for 7 d. This maneuver was associated with an increase in plasma ionized calcium. Inulin clearance experiments demonstrated that metabolic acidosis did not affect GFR, but it significantly increased both total and fractional urinary calcium excretion. To define the role of calbindin D28k, total RNA was extracted from DT, identified, and microdissected from collagenase-treated kidneys. cDNA was synthesized from RNA using reverse transcriptase and oligo(dT)(12-18) primers. Calbindin D28k mRNA abundance was semiquantified by a competitive reverse transcription-PCR, using an internal standard of cDNA that differed from the wild-type calbindin D28k by a deletion of 86 bp. The reverse transcription-PCR was performed starting from the same amount of total RNA. For each set of experiments, control and acidotic rats were studied in parallel. The identity of the DT was further verified by the presence of the thiazide-sensitive NaCl cotransporter (rTSC1) mRNA. Calbindin D28k mRNA abundance was 0.89 +/- 0.21 amol/ng total RNA in DT of CMA rats (n = 5) compared with 0.30 +/- 0.12 amol/ng total RNA of control rats (n = 5) (P < 0.05). Using specific rabbit polyclonal anti-calbindin D28k antibody, Western blotting was performed starting from thin slices of outer cortex. Densitometric analysis revealed that in acidotic rats (n = 7) there was a 17 +/- 5% (P < 0.05) increase in calbindin D28k protein abundance compared with controls (n = 7). These results indicate that in the rat, ammonium chloride loading induces an increase in filtered ionized calcium load that is associated with a significant upregulation of calbindin D28k both at the mRNA and protein level. These last effects will help to reduce the concomitant hypercalciuria, thus mitigating the consequence of CMA on calcium metabolism.
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PMID:Effect of chronic metabolic acidosis on calbindin expression along the rat distal tubule. 1066 27


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