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Biomedical subjects

B Haas

Publications and source records attributed to B Haas.

At least 73 records · Page 4Linked to original sources

Detection of foot-and-mouth disease virus in nasal swabs of asymptomatic cattle by RT-PCR within 24 hours.

A method for extracting RNA from animal-derived materials that provides foot-and-mouth disease viral template suitable for Tth polymerase-dependent synthesis of cDNA and subsequent PCR is described. Viral genomes were detected in less than 24 h. Nasal swabs that can be easily and repeatedly collected, proved suitable for virus detection by PCR, even during the asymptomatic stages of infection.

Animals↗

Inactivation of viruses in liquid manure.

The stability of some viruses and methods of virus inactivation in liquid manure are reviewed. The authors discuss experimental data on the stability of foot and mouth disease virus, classical swine fever virus, Aujeszky's disease virus, African swine fever virus, swine influenza virus, porcine paramyxovirus, bovine virus diarrhoea virus and transmissible gastroenteritis of pigs virus. Recommendations and practical advice are given for the choice and application of chemical disinfectants for slurry.

Animals↗

[Treatments of ischemic cardiopathies (IC) and modalities of prescription of aspirin in the three French MONICA centers in 1990].

In 1990, the three French MONICA centres recorded comparable frequencies of myocardial infarction admitted and not admitted to hospital. However, the mortality on the 28th day revealed an excess hospital mortality in Lille compared to Strasbourg and Toulouse (p < 0.001). Toulouse infarct patients were younger. The emergency management of coronary patients subsequently admitted to hospital also differed (16.7% patients in Lille vs 40% in Strasbourg and 24.3% in Toulouse) (p < 0.01). In Lille, 41.6% of patients had known coronary heart disease vs 30.4% in Toulouse and 38.4% in Strasbourg (p < 0.05). These three characteristics influenced the mortality. During admission, considerable differences were observed in the therapeutic strategies in the 3 centres: in Toulouse, angioplasty was predominant (51.4%) together with prescription of calcium channel blockers (65.5%) and aspirin (82.5%). In Lille, there were a high prescription (20.3%) of antiplatelets other than aspirin during the acute phase compared to Toulouse (0.6%) and Strasbourg (7.3%). In Strasbourg, the cardiologists of the department rarely used angioplasty during the acute phase, but were the leading prescribers of beta-blockers. Fibrinolysis was performed in 4 out of 10 patients in the three centres. Aspirin was used in more than 7 out of 10 patients during the acute phase in all MONICA centres, but at a variable dosage: doses greater than or equal to 250 mg per day were prescribed in Toulouse (97.6%) and Strasbourg 82.8%), while, in Lille, only one out of 2 patients received this dosage (50.6%).

Acute Disease↗

Proteasome-associated RNAs are non-specific.

The RNA isolated from RNase-treated proteasome preparations from human erythrocytes, HeLa cells, the archaeon Thermoplasma acidophilum and also from recombinant proteasomes of T. acidophilum expressed in Escherichia coli was characterized. The RNA associated with structurally similar protein particles, namely with the two molecular chaperones, groEL from E. coli and with the thermosome from T. acidophilum, served as controls. Electrophoretic analysis on polyacrylamide gels of the radioactively end-labelled RNA revealed a very similar size distribution pattern, irrespectively of the protein particles from which they had been isolated. The predominant RNA species were in the size ranges 80 nucleotides and 120 nucleotides, respectively. Partial sequencing of their terminal regions by mobility-shift analysis revealed that, of the proteasomes from human erythrocytes, the approximately 80-nucleotide-long RNA consists of a heterogenous population of mostly tRNA species because they carried the tRNA-specific 3'-terminal sequence motif 5'-CCA-3'. The RNA in the size range 120 nucleotides isolated from the proteasomes of human erythrocytes and of T. acidophilum was also heterogeneous and displayed, in the terminal regions, a remarkable sequence similarity to the corresponding regions of the 5S rRNA from the same and different organisms. The total content of RNA of all the protein particles was quantified and found to be consistently sub-stoichiometric. All these findings strongly suggest that RNA associated with the proteasomes and with the molecular chaperones originate from the abundant cellular pool of the tRNAs and 5S rRNAs which bind non-specifically to these large protein particles.

Bacterial Proteins↗

European brown hare syndrome virus: relationship to rabbit hemorrhagic disease virus and other caliciviruses.

Monoclonal antibodies directed against the capsid protein of rabbit hemorrhagic disease virus (RHDV) were used to identify field cases of European brown hare syndrome (EBHS) and to distinguish between RHDV and the virus responsible for EBHS. Western blot (immunoblot) analysis of liver extract of an EBHS virus (EBHSV)-infected hare revealed a single major capsid protein species of approximately 60 kDa that shared epitopes with the capsid protein of RHDV. RNA isolated from the liver of an EBHSV-infected hare contained two viral RNA species of 7.5 and 2.2 kb that comigrated with the genomic and subgenomic RNAs of RHDV and were recognized by labeled RHDV cDNA in Northern (RNA) hybridizations. The nucleotide sequence of the 3' 2.8 kb of the EBHSV genome was determined from four overlapping cDNA clones. Sequence analysis revealed an open reading frame that contains part of the putative RNA polymerase gene and the complete capsid protein gene. This particular genome organization is shared by RHDV but not by other known caliciviruses. The deduced amino acid sequence of the capsid protein of EBHSV was compared with the capsid protein sequences of RDDV and other caliciviruses. The amino acid sequence comparisons revealed that EBHSV is closely related to RHDV and distantly related to other caliciviruses. On the basis of their genome organization, it is suggested that caliciviruses be divided into three groups.

Amino Acid Sequence↗

[Towards a decrease of myocardial infarction in the Bas-Rhin region? Results of the 6 first years of the Strasbourg MONIC Register].

The Bas-Rhin MONICA Register shows trends in myocardial infarction and other acute ischemic events between 1984 and 1989. Coronary heart disease mortality decreased by 27% in men and 30% in women. Morbidity trends were less favourable. The annual event rate for total acute ischemic events remained stable. However, a decrease of 14% for myocardial infarction was seen in men, particularly in patients with a past history of coronary disease. Another positive point is that the 28-day mortality rate in recent infarctions decreased in men by 33% during the 5 year period.

Acute Disease↗

Quantification of apolipoprotein A-IV in human plasma by immunonephelometry.

We developed a nephelometric procedure for determining concentrations of human plasma apolipoprotein (apo) A-IV. Results obtained correlate well with those measured by an established electroimmunodiffusion assay (r = 0.98; n = 56). Intra- and interassay CVs were 2.4% and 2.0%, respectively, indicating excellent precision and reproducibility. Various conditions of sample treatment, such as adequate storage, freezing, and thawing, did not affect results significantly. However, keeping samples at room temperature for 4 days led to a slight increase in measured values. Preincubation with a cholesterinesterase-detergent mixture abolished interference from triglyceride-rich lipoproteins, allowing assay of samples containing triglycerides as great as 10 g/L. The assay is easily applicable to clinical laboratories for routine diagnostic use, as shown with hypertriglyceridemic plasmas and samples with a broad range of apo A-IV concentrations.

Adolescent↗

RNA-directed RNA polymerase from tomato leaves. I. Purification and physical properties.

An RNA-directed RNA polymerase (RdRP, EC 2.7.7.48) from tomato leaf tissue was purified to electrophoretic homogeneity. A terminal transferase activity that was found to cofractionate with RdRP from DEAE-Sepharose and DNA-cellulose columns was removed by chromatography on a Mono Q column. The highly purified RdRP exhibits a specific activity of 500 nmol x mg-1 x 30 min-1, which corresponds to a 100,000-fold enrichment of the enzyme. In buffer containing 50% glycerol, its activity decreased by about 15%/month. RdRP activity coincided with the silver staining intensity of a single 128-kDa polypeptide when the fractions eluted from the Mono Q column were analyzed by electrophoresis in a SDS-polyacrylamide gel. Its molecular mass and its sedimentation coefficient of 6.6 S indicate that RdRP is a nearly globular molecule. The catalytic activity of RdRP is resistant to alpha-amanitin and actinomycin D. In tomato leaves systemically infected with potato spindle tuber viroid, the activity of RdRP was found to be increased about 3-fold compared with RdRP isolated from healthy leaf tissue.

Chromatography, Affinity↗

RNA-directed RNA polymerase from tomato leaves. II. Catalytic in vitro properties.

The catalytic properties of electrophoretically homogeneous RNA-directed RNA polymerase (RdRP, EC 2.7.7.48) from tomato leaf tissue were studied with the aid of oligonucleotides of defined sequence. It was found that RdRP catalyzes in vitro the transcription of short single-stranded RNA and DNA molecules into precisely complementary RNA copies up to the full length of these templates. The transcription of RNA- and DNA-oligonucleotide templates was equally effective. Differences in transcription efficiency were found to depend on nucleotide sequence rather than on the RNA or DNA nature of the single-stranded nucleic acid. Double-stranded nucleic acids such as poly(A).poly(U) and a double-stranded DNA 14-mer were not transcribed. The RdRP-directed transcription could be primed because RNA and DNA dinucleotides and trinucleotides complementary to the 3'-terminal nucleotides of the template were extended by the enzyme. The unprimed transcription was shown to start preferentially at the 3'-terminal nucleotides of the template. RdRP is capable of adding a single noncomplementary nucleotide to the 3' terminus of about 50% of the runoff transcripts. AMP was preferred over GMP, whereas CMP and UMP were terminally added at very low frequency.

Base Sequence↗

Serological studies on the potential synergism of porcine reproductive and respiratory syndrome virus and influenza-, corona- and paramyxoviruses in the induction of respiratory symptoms in swine.

Sera from 265 finishing pigs belonging to 70 herds, in which severe respiratory disorders were observed, were examined for antibody prevalence to porcine reproductive and respiratory syndrome virus (PRRSV), influenza virus subtypes H3N2 and H1N1, porcine respiratory corona virus (PRCV) and a recently described porcine paramyxovirus (PPMV). By immunoperoxidase-monolayer assay 69.1% of these sera were positive for PRRSV. Hemagglutination inhibiting activity was found in 55.1% of the sera for influenza virus subtype H1N1 (strain A/swine/Arnsberg/1/81). in 51.3% for influenza virus subtype H3N2 (strain A/Hong Kong/1/68) and in 14.3% for PPMV. PRCV specific antibodies, as determined by differential competitive blocking enzyme-linked immunosorbent assay were demonstrated in 192 of 236 (81.3%) sera. In order to reveal associations interspecific coefficients were calculated for antibody prevalence between PRRSV and the other viruses. Positive associations to PRRSV titres were found to PRCV, PPMV and influenza virus subtype H1N1 titres. chi-square analysis showed the statistical significance of associations regarding PRCV and influenza virus subtype H1N1. Depletion of lung macrophages after PRRSV infection is discussed as a possible mechanism for the promotion of secondary infections.

Animals↗