National prevalence and trends of HIV transmitted drug resistance in Mexico.

BACKGROUND: Transmitted drug resistance (TDR) remains an important concern for the management of HIV infection, especially in countries that have recently scaled-up antiretroviral treatment (ART) access. METHODOLOGY/PRINCIPAL FINDINGS: We designed a study to assess HIV diversity and transmitted drug resistance (TDR) prevalence and trends in Mexico. 1655 ART-naïve patients from 12 Mexican states were enrolled from 2005 to 2010. TDR was assessed from plasma HIV pol sequences using Stanford scores and the WHO TDR surveillance mutation list. TDR prevalence fluctuations over back-projected dates of infection were tested. HIV subtype B was highly prevalent in Mexico (99.9%). TDR prevalence (Stanford score>15) in the country for the study period was 7.4% (95% CI, 6.2∶8.8) and 6.8% (95% CI, 5.7∶8.2) based on the WHO TDR surveillance mutation list. NRTI TDR was the highest (4.2%), followed by NNRTI (2.5%) and PI (1.7%) TDR. Increasing trends for NNRTI (p = 0.0456) and PI (p = 0.0061) major TDR mutations were observed at the national level. Clustering of viruses containing minor TDR mutations was observed with some apparent transmission pairs and geographical effects. CONCLUSIONS: TDR prevalence in Mexico remains at the intermediate level and is slightly lower than that observed in industrialized countries. Whether regional variations in TDR trends are associated with differences in antiretroviral drug usage/ART efficacy or with local features of viral evolution remains to be further addressed.

Microbead-based affinity chromatography chip using RNA aptamer modified with photocleavable linker.

A microbead-based affinity chromatography chip (micro-BACC) controlling hundreds of nanoliters of reaction volume was developed to separate and analyze hepatitis C virus (HCV) RNA polymerase protein by immobilization of an RNA aptamer on beads. A photocleavable linker was conjugated in between the beads and the aptamer to elute the bound RNA polymerase from the RNA aptamer in one step by UV irradiation, resulting in an efficient method to elute and identify the target molecule bound on RNA using a mass spectrometer. This linker showed a cleavage activity over 70% upon UV irradiation at 1050 mW/cm2 for more than 5 min. The photoelution method could prevent the target molecule from contaminations in affinity chromatography caused by elution solutions of high salt concentration, extreme pH and detergent, respectively. In this chip, sample reagents up to 800 nL could be metered quantitatively into the bead chamber using a nanoliter dispenser working, based on surface-guided flow control and pneumatic control by external air pressure on the chip. RNA polymerase eluted after UV irradiation was successfully analyzed by trypsin treatment without additional purification. As a result, using the aptamer, we could detect RNA polymerase from 800 nL hepatitis C patient serum containing 96 fmol HCV RNA polymerase. The detection limit of this system was estimated to be 9.6 fmol HCV RNA polymerase.

Identification of beta-subunit of bacterial RNA-polymerase--a non-species-specific bacterial protein--as target of antibodies in primary biliary cirrhosis.

Several observations suggest that bacteria induce autoimmunity in primary biliary cirrhosis (PBC). Since no PBC-specific bacterial species could be identified, it can be speculated that the triggers are non-species-specific bacterial proteins. This hypothesis would imply that several or even all bacterial species can trigger PBC. Therefore, we investigated whether PBC exhibits immune reactions to non-species-specific bacterial antigens. Yersinia enterocolitica O3 was screened for the presence of proteins that were labeled by immunoblotting using PBC sera. We focused our investigations on a 160-kDa protein, which was further enriched and characterized by partial N-terminal amino acid sequencing. The prevalence of antibodies to this protein was determined by immunoblotting in a variety of diseases. The 160-kDa protein was identified as the beta-subunit of bacterial RNA-polymerase, a highly conserved bacterial protein with a very high degree of sequence identity among all bacterial species. Antibodies to the beta-subunit of bacterial RNA polymerase were specific for this protein. Until now no mammalian protein could be found that cross-reacts with these antibodies. The prevalence of antibodies to the beta-subunit of bacterial RNA polymerase (ARPA) using the protein from Yersinia enterocolitica O3 (serum dilution 1:1000) was: healthy controls (HC, N = 101) 7.9%, primary biliary cirrhosis (PBC, N = 61) 32.8%, autoimmune hepatitis type 1 (AIH, N = 46) 26.1%, alcoholic liver cirrhosis (ALC, N = 44) 9.1%, Crohn's disease (CD, N = 38) 7.9%, ulcerative colitis (UC, N = 24) 8.3%, primary sclerosing cholangitis + UC (PSC/UC, N = 11) 0%, acute yersiniosis (Yers, N = 36) 19.4%, acute infection with Campylobacter jejuni (Camp, N = 10) 0%, acute Q-fever (QF, N = 16) 6.25%, chronic hepatitis C (HCV, N = 39) 7.7%, c-ANCA-positive vasculitis (Vasc, N = 40) 15%, systemic lupus erythematosus (SLE, N = 28) 10.7%, and malaria tropica (MT, N = 24) 16.7%. There was no significant difference between PBC and AIH. The group of autoimmune liver diseases (PBC + AIH, N = 107, 29.9%) differed highly significantly from HC, chronic inflammatory bowel diseases (CD + UC + PSC/UC, N = 73, 6.8%), ALC, and HCV and also differed significantly (P = 0.01) from the group with bacterial and parasitic diseases (Yers + Camp + QF + MT, N = 86,13.95%) and from the group with Vasc + SLE (N = 68,13.2%). Testing of ARPA using the protein from E. coli yielded nearly identical results. In conclusion, an increased prevalence of antibodies to the beta-subunit of bacterial RNA polymerase, a highly conserved non-species-specific bacterial protein, can be found in primary biliary cirrhosis, but also in autoimmune hepatitis type I. These findings do not add an argument for a bacterial trigger of PBC. Rather, they suggest that ARPA belong to the pool of natural antibodies that are up-regulated in autoimmune liver diseases.

DNA-dependent RNA polymerase enzymes affected in uraemic lymphocyte cells.

The DNA-dependent RNA polymerase activity and endonucleases in uraemic lymphocyte cells were investigated. It was found that the activity and quantity in three classes of polymerases are remarkably reduced. The reduction in enzyme activity is accompanied by increasing endonuclease activity. The relationship of polymerase enzymes with endonucleases is discussed.

[Metabolic differentiation of peripheral blood lymphocytes after kidney transplantation in relation to post-transplantation immuno- suppression in the light of the analysis of cellular activity of DNA transcription enzymes]. / Zróznicowanie metaboliczne limfocytów krwi obwodowej chorych po przeszczepieniu nerek w zaleznosci od zastosowanej immunosupresji potransplantacyjnej w swietle analizy komórkowej aktywnosci enzymów transkrypcyjnych DNA.

The activity of three classes DNA-dependent RNA polymerases in T and B lymphocyte cells nuclei isolated from peripheral blood of patients with transplanted kidney were investigated. Twenty three patients with transplanted organ in age 35 +/- 9.7 treated simultaneously with cyclosporin A and small doses of prednisone and thirteen persons after renal transplantation in age 34.8 +/- 6.3 treated conservatively (azathioprine plus prednisone) were studied. The enzymes activity was assayed by the measurement of [3H] UTP incorporated into acid insoluble product in the presence of alpha-amanitin when specified. Both, "bound" and "free" enzymes activity was analysed. "Bound" polymerase is defined by the ability to transcribe endogenous template in the absence of exogenous DNA. "Free" enzyme was determined by the additional transcription on exogenous, calf thymus DNA as template. The quantity of polymerase I subunits by Western blotting was also analysed. It was shown that the polymerizing enzymes activity strongly depend upon haemodialysis period of time prior to organ transplantation as well as upon the treatment after transplantation. Characteristically in case of T lymphocyte isolated from patients treated with cyclosporin A, the transplant rejection process was accompanied by large increasing in polymerase activity especially in polymerase I. The correlation in polymerase activity and transplant rejection time was clearly observed. In case of lymphocyte cells isolated from patients with renal transplant treated conservatively, the polymerase activity in both T and B cell was slightly reduced. The useful of polymerase assay for monitoring of patients with renal transplant is considered.

[Analysis of the activity of matrix DNA synthesis in the lymphocytes of patients after kidney transplantation and the role of the processes of degradation of DNA-dependent RNA polymerases in the overall cellular nucleolytic activity]. / Analiza aktywnosci enzymów syntezy matrycowego DNA w limfocytach chorych po przeszczepieniu nerek i udzial procesów degradacji polimeraz RNA zaleznych od DNA w calkowitej aktywnosci nukleolitycznej komórki.

The activity and quantity of deoxyribonucleases in T and B lymphocyte cells isolated from peripheral blood of patients with transplanted kidney were investigated. Twenty three patients with transplanted organ, aged 35 +/- 9.7, treated with cyclosporin A and thirteen individuals after renal transplantation in age 34.8 +/- 6.3 treated conservatively were studied. The enzyme activity was defined as resting DNase activity (DNase 0). Where specifiel the reaction mixture was supplied either with 5 mM MgCl2 (DNaseMg2+) or 1 mM MnCl2 (DNase1 x Mn2+) or 2 mM MnCl2 (DNase2 x Mn2+). Two enzyme groups with molecular mass 32 kDa and 14 to 18 kDa were analyzed. It was evidenced that the nuclease activity in B lymphocyte isolated from patients treated with cyclosporin A after organ transplantation was quite close to the control subjects. On the contrary, the nucleases activity and quantity increased in T lymphocyte of the same patients and increasing in enzymes activity was depending upon haemodialysis period of time prior to organ transplantation. Enzymes activity correlate with clinical parameters typical for kidney transplant rejection. The activity and quantity of nucleases was slightly reduced in both T and B lymphocytes isolated from patients treated conservatively after organ transplantation. The useful of nuclease assay for monitoring of kidney transplant rejection is discussed.

The control of ribosomal RNA transcription in lymphocytes. Evidence that the rate of chain elongation is the limiting factor.

During activation of lymphocytes by phytohaemagglutinin, the nuclear activity of RNA polymerase I increases with no proportional increase in the amount of catalytic efficiency of the enzyme in the cell. The mechanism by which rRNA transcription in lymphocytes is modified by phytohaemagglutinin stimulation was investigated. The following results were obtained. (a) In resting lymphocytes all RNA polymerase II molecules are bound to the template while a pool of excess free RNA polymerase I, not engaged in transcription, can be detected by its ability to transcribe added poly[d(A-T)]. (b) Although the free RNA polymerase I activity increases twofold to threefold during phytohaemagglutinin stimulation, there is no evidence that the free enzymes ever become engaged in transcription. (c) Most of the RNA chains in elongation in nuclei from resting lymphocytes are being elongated by class II RNA polymerase and their rate of elongation is much higher than that of other RNA species. (d) The same number of pre-rRNA chains are in the process of being elongated in nuclei from resting and stimulated lymphocytes. However, the rate of elongation of pre-rRNA, which is slow relative to the average in resting lymphocytes, increases twofold to threefold within 6 h of phytohaemagglutinin stimulation and rises to sixfold by 19 h. These results suggest that the control of rRNA transcription in phytohaemagglutinin-stimulated lymphocytes lies in the elongation step of transcription rather than in initiation, and that little or no additional rRNA template is transcribed in phytohaemagglutinin-stimulated lymphocytes.

[Stress and aging (author's transl)]. / Stress und Altern.

Under the influence of stress the function of hypothalamic-pituitary system seems to show aging changes, whereas the adrenocortical function is not changed in spite of degenerative morphological changes in aging. By the performance and interpretation of experiments it is necessary to pay attention to the different reaction of young and old animals.

Nucleotide polymerases in the developing avian erythrocyte.

Avian erythroid cells were separated into five developmental stages by sedimentation on discontinuous isotonic albumin gradients. Solubilized enzyme activities from whole cells were partially purified and characterized by ion exchange and ion filtration chromatography and velocity sedimenttation analysis. Three nucleotide polymerase types were investigated: (a) DNA-dependent RNA polymerases; (b) RNA-dependent terminal ribonucleotidyltransferases, and (c) DNA-dependent DNA polymerases. The two characteristic forms of eucaryotic DNA-dependent RNA polymerases, polymerase I (nucleolar) and polymerase II (nucleoplasmic), were identified. Polymerase III was only marginally detectable even in the earliest developmental populations. At least two species of RNA-dependent terminal ribosyltransferases were present. One apparently was the poly(A) polymerase observed in other systems. The other terminal transferase was present in two chromatographic forms, required an RNA primer, and used UTP and/or CTP as particularly efficient substrates. Three DNA polymerase activities were resolved, two of which were characteristic of the alpha and beta DNA polymerases described in other eucaryotic systems. The third polymerase was not the gamma polymerase but a separate entity. Poly(dC)-dependent RNA polymerase activity, associated with the alpha polymerase, was relatively enriched in the third DNA polymerase species. The activity levels of the nucleotide polymerases were monitored as a function of red cell maturation. Characteristic declining patterns of activity were obtained for each enzyme which correlate well with the synthetic rates of their in vivo products where these are known. These results correlate well with the synthetic rates of their in vivo products where these are known. These results are consistent with the postulate that the general transcriptive and replicative control processes operating during development may involve changes in the level of the requisite polymerases.

[DNA-dependent RNA polymerases in human leukocytes. II different specific activities of the polymerases A and B in acute and chronic leukemia and their prognostic relevance (author's transl)]. / DNA-abhängige RNS-Polymerasen in menschlichen Leukocyten. II. Unterschiedliche spezifische Aktivitäten der Polymerasen A und B bei akuten und chronischen Hämoblastosen und ihre mögliche prognostische Bedeutung.

Specific Activities of DNA-dependent RNA polymerases A and B have been determined in nuclei from leukocytes in acute and chronic leukemia. Enzyme activities, dependent on exogenous DNA template, were determined in homogenates of nuclei from isolated mononuclear cells or from isolated granulocytes. Activities of polymerases A and B have been found significantly elevated in homogenates of nuclei from mononuclear cells in acute myelocytic leukemia, while they were found subnormal in corresponding cell fractions from chronic myelocytic leukemia and chronic lymphatic leukemia. During cytostatic treatment polymerase activities were approaching normal values. The prognostic relevance of these data for the course of human leukemia is discussed.

Reticulocyte RNA-dependent RNA polymerase.

A cytoplasmic, microsomal bound RNA-dependent RNA polymerase has been purified 2500-fold from rabbit reticulocyte lysates. The synthesis of RNA with the purified enzyme is absolutely dependent on the addition of an RNA template. The best template is hemoglobin messenger RNA, while bacteriophage RNA and poly(A,G) are less active, and DNA is completely inactive as a template. With poly(A,G) as a template, only UTP and CTP are incorporated into polynucleotide chains, indicating that the RNA polymerase is an RNA replicase and not a terminal transferase. With messenger RNA as a template, all four ribonucleoside triphosphates are required for maximal activity. The RNA-dependent RNA polymerase reaction is extremely sensitive to low concentrations of heme, rifamycin AF/013, and ribonuclease and resistant to actinomycin D and DNase. The discovery of RNA-directed RNA synthesis in reticulocytes offers an additional site for control of gene expression in mammalian cells and provides a possible mechanism for amplification of the expression of specific genes.

Action of rifamycin derivatives on RNA polymerase of human leukemic lymphocytes.

The mechanism of inhibition of human RNA polymerase by four rifamycin derivatives was investigated. Derivative AF/013 (3-formyl rifamycin SV:O-n-octyloxime) with strong hydrophobic side chains prevents the polymerase from binding to DNA and also affects the size of RNA synthesized. Derivative PR/19 (3'-acetyl-1'-benzyl-2'-methylpyrrolo[3,2-c]-4-desoxy-rifamycin SV) only affects RNA synthesis when RNA polymerase has been previously incubated with the drug or when the reaction was performed at high salt concentration [0.14 M (NH(4))(2)-SO(4)]. Our results suggest that these drugs exert their inhibitory actions by binding to the enzyme instead of DNA.