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Biomedical subjects

V Misra

Publications and source records attributed to V Misra.

At least 19 recordsLinked to original sources
PubMed1992

Sequences of the bovine herpesvirus 1 homologue of herpes simplex virus type-1 alpha-trans-inducing factor (UL48).

A virion protein of herpes simplex virus type-1, called Vmw65, alpha TIF or VP16, interacts with cellular transcription factors to transactivate immediate early viral genes. We have cloned and determined the nucleotide sequence of the gene encoding the homologous protein in bovine herpesvirus 1 (BHV-1). The amino acid sequence of the BHV-1 protein is similar to that of alpha TIF, except in the C-terminal one-third of the protein. Since the ability of alpha TIF to activate transcription is dependent on this region, our results suggest that the BHV-1 homologue either does not act as a transactivator or activates genes by a different mechanism.

Amino Acid Sequence↗
PubMed1992

Proton exchange in DNA-luzopeptin and DNA-echinomycin bisintercalation complexes: rates and processes of base-pair opening.

Imino proton exchange studies are reported on the complexes formed by bisintercalation of luzopeptin around the two central A.T pairs of the d(CCCATGGG) and d(AGCATGCT) duplexes and of echinomycin around the two central C.G pairs of the d(AAACGTTT) and d(CCAAACGTTTGG) duplexes. The depsipeptide backbone of the drugs occupies the minor groove of the complexes at the bisintercalation site. The exchange time of the amide protons of the depsipeptide rings provides a lower estimate of the complex lifetime: 20 min at 15 degrees C for the echinomycin complexes and 4 days at 45 degrees C for the luzopeptin complexes. The exchange time of imino protons is always shorter than the complex lifetime. Hence, base pairs open even within the complexed oligomers. For the two base pairs sandwiched between the aromatic rings of the drug, the base-pair lifetime is strongly increased, and the dissociation constant is correspondingly reduced. Hence, the lifetime of the open state is unchanged. This suggests similar open states in the free duplex and in the complex. In contrast to the sandwiched base pairs, the base pairs flanking the intercalation site are not stabilized in the complex. Thus, the action of the bisintercalating drug may be compared to a vise clamping the inner base pairs. Analysis suggests that base-pair opening may require prior unwinding or bending of the DNA duplex.

Ammonia↗
PubMed1992

Detection of pathogenic Yersinia enterocolitica by polymerase chain reaction and digoxigenin-labeled polynucleotide probes.

Yersinia enterocolitica is widespread in nature, but only a few bioserotypes are involved in human infections. Pigs are considered to be the major reservoirs of pathogenic strains. It is essential to have an accurate and rapid method for the detection of pathogenic yersiniae. To achieve this objective, 19-base synthetic oligonucleotide primers were used in a polymerase chain reaction (PCR) to detect the ail gene (which is conserved only in pathogenic strains) in strains of Y. enterocolitica and related species originating from pigs or pork products. Digoxigenin-labeled probes derived from the ail, inv, and yst genes were also evaluated on these strains. The PCR amplified a 273-bp fragment of the ail gene involved in eukaryotic cell invasion and serum resistance. The PCR detected template DNA only in strains of Y. enterocolitica traditionally classified as human pathogens but not in biotype 1A strains and related species. Other members of the family Enterobacteriaceae were also negative for the target gene. The digoxigenin-labeled ail probe gave identical results to the PCR. By use of this nonisotopic method, inv-homologous DNA was detected only among yersiniae, except for Y. ruckeri. Although all pathogenic serotypes of Y. enterocolitica were positive for the heat-stable enterotoxin yst gene, two strains of biotype 1A, one Y. intermedia strain, and six other species of the Enterobacteriaceae were also positive. Our results support the notion that pigs constitute an important reservoir of pathogenic Y. enterocolitica and that the inv-homologous sequence is Yersinia specific.

Bacteria↗
PubMed1992

Detection of equine herpesvirus and differentiation of equine herpesvirus type 1 from type 4 by the polymerase chain reaction.

Although both equine herpesvirus type 1 (EHV-1) and equine herpesvirus type 4 (EHV-4) can be associated with respiratory disease, epizootics caused by EHV-1 are much more serious because the virus can cause abortions and paralysis. It is, therefore, important to identify the type of EHV involved in an outbreak by a test that is quick, sensitive, and reliable. We have adapted the polymerase chain reaction (PCR) to detect and distinguish between EHV-1 and EHV-4 in the same reaction. Primers for PCR were designed from the sequences of the glycoprotein B genes of EHV-1 and EHV-4. The PCR products derived from EHV-1 and EHV-4 were 135 and 326 base pairs, respectively, and could be readily separated by electrophoresis. The identity of the PCR products was confirmed by determining their nucleotide sequence, which agreed with the published sequence of the gB genes. The test could be performed directly on virus pelleted from small volumes (300 microL) of medium in which nasal swabs were transported and did not rely on the presence of infectious virus. The PCR was unaffected by conditions that reduced the infectivity of a virus preparation by 99%. The PCR detected EHV-4 in 5 of 10 nasal mucous samples taken from an outbreak of respiratory disease in race horses. Virus isolation in indicator cells was successful in detecting virus in four of the five samples positive by PCR.

Animals↗
PubMed1992

Partial characterization of the gonadotropin-releasing hormone (GnRH) gene transcript in the rat ovary.

It has been hypothesized that GnRH or a GnRH-like peptide is produced in the rat ovary, but the presence of GnRH in the ovary has not been unequivocally demonstrated. This study was undertaken to determine whether the GnRH gene is expressed in the rat ovary and to compare the GnRH gene transcripts from the ovary and the hypothalamus. Twelve samples of total RNA from ovaries of individual rats were screened by reverse transcription-polymerase chain reaction (RT-PCR) for the presence of GnRH gene transcripts. Fragments of GnRH cDNA were amplified using pairs of specific primers. GnRH transcripts were detected in all the ovaries examined, and differed from hypothalamic GnRH transcripts in two ways: first, in the ovaries a greater proportion of GnRH transcripts contained intronic sequences; second, the major transcription start utilized in the ovary differed from that used in the hypothalamus. Although fully processed GnRH gene transcripts were detected by RT-PCR in both, ovary and hypothalamus, they were not detected in the ovary by Northern blot. The GnRH probe hybridized specifically to the predicted 0.6 kb transcript in the hypothalamus, and to a 3.3 kb transcript in the ovary. We conclude that in the ovary, most GnRH gene transcripts retain intronic sequences.

Animals↗
PubMed1992

Rational model for comparing vulnerability to environmental health risks at different locations.

Many factors must be considered in correlating the environmental quality of a location with the disease pattern. Therefore, an attempt is made to identify the rationale needed to correlate human disease patterns with pollutant loads and a simple, though arbitrary, and qualitative model for distinguishing areas more prone to environmental health risks is suggested.

Environmental Health↗
PubMed1992

Sucralfate versus ranitidine in non-ulcer dyspepsia: results of a prospective, randomized, open, controlled trial.

In an open trial, 100 patients with non-ulcer dyspepsia were randomized to receive either ranitidine 150 mg twice daily (n = 47) or sucralfate 1 g four times a day (n = 53) for four weeks. An 'intention to treat' analysis revealed that global relief in symptoms was significantly more frequent in the sucralfate group than in the ranitidine group after two weeks (77.4% vs 59.6%; p less than 0.05) and four weeks (86.8% vs 63.8%; p less than 0.001) of treatment. It is concluded that sucralfate is superior to ranitidine in providing symptomatic relief in patients with non-ulcer dyspepsia.

Adult↗
PubMed1991

Biochemical alterations in fish fingerlings (Cyprinus carpio) exposed to sublethal concentration of linear alkyl benzene sulphonate.

Fish fingerlings (Cyprinus carpio) were exposed to sublethal concentrations of linear alkyl benzene sulphonate (0.005 ppm) for 24, 48, and 96 h under static laboratory conditions. Alterations were noted in the levels of glycogen, lactic acid, sialic acid, and acid and alkaline phosphatases in the gill, liver, and kidney. This chemical may impair metabolic processes in fingerling carp, because increased exposure resulted in significant increases in lactic acid and decreases in glycogen and sialic acid along with inhibition of acid and alkaline phosphatase activity.

Animals↗
PubMed1991

Risk analysis in hazardous industries.

The importance of the approach of risk analysis in industry, as an anticipatory action to prevent disasters, and the principles involved in it are discussed. Toxicological considerations of long-term low-dose exposure during routine operations and short-term high-dose exposure after chemical accidents are outlined. On the basis of these concepts a rationale for preliminary assessment of disaster-prone industries is presented.

Industry↗
PubMed1991

Gallbladder dynamics in patients with irritable bowel syndrome and essential dyspepsia.

To assess whether gallbladder motility is altered in patients with irritable bowel syndrome (IBS) or essential dyspepsia (ED), we studied gallbladder function in 25 healthy volunteers, 20 patients with IBS, and 22 with ED. By real time ultrasonography, we studied the following parameters: (a) fasting gallbladder volume, (b) maximum percent of gallbladder emptied, (c) time required for maximal contraction, (d) residual volume after maximal contraction, and (e) percent fasting volume at 2 h. All parameters, except fasting gallbladder volume, were measured after a high-fat meal. The fasting gallbladder volume, maximum percent of gallbladder emptied, time required for maximal contraction, residual volume after maximal contraction, and percent fasting volume at 2 h in controls and patients with IBS was 19.3 +/- 8.8 ml and 24.4 +/- 9.7 ml, 67.1 +/- 10.7% and 67.6 +/- 13.5%, 41 +/- 20.6 min and 49.7 +/- 25.3 min, 6.2 +/- 3.3 ml and 7.6 +/- 5.3 ml, and 38.1 +/- 12.2% and 40.7 +/- 14.5%, respectively. The differences between the two groups were statistically not significant. The corresponding values in patients with ED were 15.5 +/- 6.3 ml, 57.6 +/- 16.5%, 51.8 +/- 29.3 min, 6.1 +/- 3.2 ml, 44.1 +/- 17%, respectively. Compared with controls there was no statistically significant difference in these parameters, except the maximum percent of gallbladder emptied, which was significantly less than that in controls (57.6 +/- 16.5% vs. 67.1 +/- 10.7%; p less than 0.05). Therefore, we could not find that patients with IBS have any abnormality of gallbladder function; postprandially, patients with ED have submaximal contraction of the gallbladder.

Adolescent↗
PubMed1991

The most abundant protein in bovine herpes 1 virions is a homologue of herpes simplex virus type 1 UL47.

The bovine herpesvirus type 1 (BHV-1) protein VP8 is present, in large amounts, in the tegument of virions. As a preliminary step towards determining the function of VP8 and the biological relevance for its abundant presence, we describe the mapping of the location of its gene and determination of its nucleotide sequence. The gene for VP8 was located between 0.088 and 0.108 map units on the BHV-1 genome and contained a 2226 bp reading frame encoding a 742 amino acid protein. The protein, produced in vitro by transcribing and translating the reading frame, was precipitated by monoclonal antibodies and polyclonal serum directed against VP8. The primary structure of VP8 showed considerable homology with the product of the UL47 reading frame of herpes simplex virus type 1.

Amino Acid Sequence↗
PubMed1991

Construction of herpes simplex viruses that are pseudodiploid for the glycoprotein B gene: a strategy for studying the function of an essential herpesvirus gene.

The primary structure of glycoprotein B (gB) is conserved strongly among many members of the Herpesviridae, including some that differ vastly in their natural properties. To determine whether the structural similarity between the gBs of herpes simplex virus type 1 (HSV-1) and bovine herpesvirus type 1 (BHV-1) was reflected in functional homology, we constructed pseudodiploid HSV-1 virions which, in addition to their own gene encoding gB, also contained a gene for encoding BHV-1 gB. Two kinds of pseudodiploid viruses were constructed. In one, the coding sequences of the BHV-1 gB gene were linked to the 5' flanking sequences of the HSV-1 thymidine kinase (TK) gene. In the other, the entire BHV-1 gB gene, including its own flanking sequences, was introduced into the TK gene. In cells infected with the viruses both HSV-1 and BHV-1 gB were made but they could be distinguished immunologically by monoclonal antibodies. Both glycoproteins were inserted into cellular and virion membranes but did not form oligomers with each other. A monoclonal antibody that binds to HSV-1 gB but not BHV-1 gB neutralized the parental HSV-1 and a revertant pseudodiploid virus from which the gene encoding BHV-1 gB had been excised, but was significantly less efficient at neutralizing the pseudodiploid viruses. This suggests that the BHV-1 homologue can complement the HSV-1 gB functions required for infectivity.

Animals↗
PubMed1991

Cleavage of the bovine herpesvirus glycoprotein B is not essential for its function.

Herpes simplex virus glycoprotein B (HSVgB) and its bovine herpesvirus homologue (BHVgB) share similar primary structures. These glycoproteins are present in the envelope of the virion and are believed to initiate infection by fusing the virus envelope with a host cell membrane. BHVgB, like the membrane-fusing glycoproteins of most enveloped viruses, is normally cleaved and is present as a disulphide-linked complex in the virus envelope and host cell membranes. HSVgB, however, remains uncleaved, presumably because it lacks a similar protease recognition sequence. To determine whether the cleavage of BHVgB is essential for its role in initiating infection, we altered the coding sequence of this glycoprotein by removing the protease cleavage site and making this region similar to that of HSVgB. The mutant BHVgB gene was expressed by an HSV recombinant virus in mouse L cells and produced an uncleaved BHVgB. The uncleaved BHVgB could complement the function of HSVgB which had been neutralized by monoclonal antibody H233. When expressed in mouse L cells, the uncleaved mutant BHVgB retained its ability to fuse membranes.

Amino Acid Sequence↗
PubMed1991

Detection of bovine viral diarrhea virus, using degenerate oligonucleotide primers and the polymerase chain reaction.

A technique for detection of bovine viral diarrhea virus (BVDV) from circulating blood leukocytes, using the polymerase chain reaction, is described. The published nucleotide sequences of 2 strains of BVDV and that of hog cholera virus were aligned and the information was used to design oligonucleotides coding for 2 regions of amino acid homology. The oligonucleotides were a mixed population including all possible codons for the conserved amino acids. These degenerate oligonucleotides were used in the polymerase chain reaction to detect viral RNA in cells infected in vitro, or in circulating blood leukocytes from infected animals. Virus was detected in over 60 samples from diverse isolates. The detection of BVDV by the polymerase chain reaction is a rapid, sensitive, and specific technique, which represents an improvement over existing technology.

Abortion, Veterinary↗