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Biomedical subjects

W Meinke

Publications and source records attributed to W Meinke.

At least 19 recordsLinked to original sources

Isolation and characterization of the major capsid protein of bovine papilloma virus type 1.

The major capsid protein of bovine papilloma virus type 1 (BPV-1) was isolated by gel filtration following disruption of purified virus particles with guanidine hydrochloride. The capsid protein, VP1, has a mol. wt. of about 53 500. Amino acid composition studies of VP1 showed that it is a highly acidic protein containing almost twice the average number of acidic residues than basic residues. Relatedness was observed between VP1 and the major capsid proteins of simian virus 40 (SV40) and polyoma virus.

Amino Acids↗

Virus detection by nucleic acid hybridization: examination of normal and ALS tissues for the presence of poliovirus.

A nucleic acid hybridization assay was developed as a sensitive assay for the presence of poliovirus RNA in human tissue. The assay could detect the presence of an average of one poliovirus per 200 cells. A method for determining the extent of degradation of the tissue RNA was developed and used to show that a significant fraction of human central nervous system (CNS) autopsy material contains highly degraded RNA which is unsuitable for hybridization studies. A total of 15 different control and amyotrophic lateral sclerosis tissues were assayed for the presence of poliovirus-like RNA. Virus RNA was detected in one of the control tissues and in none of the ALS tissues.

Amyotrophic Lateral Sclerosis↗

Immunologic detection of condylomata acuminata-specific antigens.

A rabbit serum fraction was prepared which contained antibody specific for unique antigen(s) found in human condylomata acuminata tissue but not in other human papillomatous or normal tissues. Indirect immunofluorescent staining of cryostat sections of human tissues demonstrated an intense nuclear fluorescence in cells of the prickle cell layer of condylomata acuminata sections. Nuclear fluorescence was not apparent in cells in the basal or dermal layers. The serum fraction did not elicit nuclear fluorescence in epithelial cells of tissue from human vulva, human foreskin, juvenile hand wart, plantar wart, or squamous cell papilloma of the cervix. This demonstration of antigens unique to epithelial cells of condylomata acuminata may prove useful in the often difficult diagnosis of cervical condylomata.

Antigens, Neoplasm↗

Simian virus 40-related DNA sequences in a human brain tumor.

Papovaviruses can induce experimental brain neoplasms in animals, and some papovaviruses have been implicated in the formation of various human tumors. We examined a series of seven human brain tumors removed at craniotomy for the presence of viral DNA sequences by the technique of DNA-DNA hybridization. Simian virus 40 (SV40) DNA was labeled in vitro and used as a "probe" for detecting related DNA sequences in cellular DNA extracted from brain tumors. SV40-related DNA sequences were found in DNA extracted from one tumor, a glioblastoma multiforme. It was calculated that approximately 1.2 viral genome equivalents per diploid cell were present in the tumor. Since the rate of reassociation of the probe deviated from ideal second-order kinetics, it is surmised that either only a portion of the SV40 genome was present in tumor cells or, alternatively, that the probe detected a related human papovavirus.

Animals↗

Flow microfluorometric analysis of herpesvirus infected BHK-21 and BALB/3T3 cell cultures.

The interaction of herpes simplex type 1 with two eukaryotic cell lines (BHK-21 and BALB/3T3) was investigated by flow microfluorometric analysis after cell staining with mithramycin. Uninfected, lytically infected and persistently infected cell populations were examined. Viral replication within an infected cell population could be detected via FMF analysis. The low levels of viral replication occurring within persistently infected cell populations were also detectable. A marked degree of correlation was noted between morphological observations of infected cultures and the FMF profiles obtained. The results deomonstrate the great potential of this technique for the early detection and analysis of viral infection.

Cell Count↗

Bovine papilloma virus: presence of virus-specific DNA sequences in naturally occurring equine tumors.

Four of five spontaneous benign equine connective tissue tumors of unknown etiology and a bovine papilloma virus (BPV)-induced equine tumor contained BPV-specific DNA sequences as determined by DNA-DNA hybridization of DNA from tumors with BPV DNA labeled in vitro. Analysis of the kinetics of reassociation indicated that 20-75% of the BPV genome was present in the various tumors. The number of partial BPV genome equivalents ranged from 60 to 500 copies per diploid quantity of cellular DNA. Thermal denaturation profiles of duplexes formed between labeled BPV DNA and DNA from tumor cells indicated two tumors contained viral DNA with base sequences identical to BPV DNA. Three tumors (including DNA from the BPV-induced tumor) contained BPV-related DNA sequences that were less thermally stable. The decrease in thermal denaturation temperature may be due to the presence of (adenine + thymine)-rich regions of the BPV genome in the tumor cells.

Animals↗

In vitro-labeled DNA for detecting viral genomes in multiple sclerosis: I. Papovaviruses.

Papovaviruses appear to be neurotropic and one, JC virus, is implicated as the cause of one type of demyelinating disease, progressive multifocal leukoencephalopathy. To investigate whether human papovaviruses play a role in multiple sclerosis, radioactively labeled DNA from BK virus, human papilloma virus, and simian virus 40 was used as a probe in order to detect related unlabeled DNA sequences in DNA isolated from multiple sclerosis brain and/or spinal cord. Labeled viral probes were denatured and DNA allowed to reassociate in the presence of excess unlabeled DNA from multiple sclerosis tissue or from controls. The reassociation rate of the probe is proportional to the concentration of viral DNA present, and an increase in the reassociation rate of the probe over that of control reactions would indicate the presence of unlabeled viral DNA in multiple sclerosis cellular DNA. However, addition of DNA derived from multiple sclerosis patients did not increase rates of reassociation of viral probes. Known human papovaviruses probably have no role in the pathogenesis of multiple sclerosis.

BK Virus↗

Quantitation of bovine papilloma viral DNA in viral-induced tumors.

Bovine papilloma virus (BPV) DNA was labeled in vitro under conditions of repair synthesis and subsequently used as a "probe" in DNA-DNA reassociation studies to detect BPV-specific DNA sequences in a viral-induced calf meningioma and hamster fibroma. In vitro labeled BPV DNA had denaturation characteristics expected for duplex DNA and denatured DNA reassociated with apparent second-order kinetics. Analysis of in vitro labeled BPV DNA reassociation rates in the presence of excess tumor DNA revealed that the calf meningioma contained approximately 700 to 800 BPV genome equivalents per diploid cell whereas the hamster fibroma contained about 150 incomplete BPV genome equivalents per diploid cell. Thermal denaturation of in vitro labeled BPV DNA which reassociated in the presence of the two tumor DNA preparations indicated less than 1.5% base pair mismatching.

Animals↗

Localization of cytoplasmic-membrane-associated DNA in human chromosomes.

In situ hybridization was used to localize the sites of the repeated sequences of cytoplasmic-membrane-associated DNA (cmDNA) in human chromosomes. cmDNA was mainly present in the heterochromatic regions of chromosomes 9. Although cmDNA has buoyant densities in neutral and alkaline CsCl gradients similar to those of human satellite C DNA, which also is localized in the heterochromatic region of chromosomes 9, cmDNA was not homologous to satellite C DNA as determined by DNA-complementary RNA hybridization. These results are in agreement with our previous studies, which indicated that cmDNA is a unique species of human DNA.

Binding Sites↗

Proteins in intracellular simian virus 40 nucleoportein complexes: comparison with simian virus 40 core proteins.

Intracellular nucleoprotein complexes containing SV40 supercoiled DNA were purified from cell lysates by chromatography on hydroxyapatite columns followed by velocity sedimentation through sucrose gradients. The major protein components from purified complexes were identified as histone-like proteins. When analyzed by electrophoresis in sodium dodecyl sulfate-polyacrylamide gels, complex proteins comigrated with viral core polypeptides VP4, VP5, VP6, and VP7. (3H) tryptophan was not detected in polypeptides from intracellular complexes or in the histone components from purified SV40 virus. However, a large amount of (3H) tryptophan was found in the viral polypeptide VP3 relative to that incorporated into the capsid polypeptides VP1 and VP2. Intracellular complexes contain 30 to 40% more protein than viral cores prepared by alkali dissociation of intact virus, but when complexes were exposed to the same alkaline conditions, protein also was removed from complexes and they subsequently co-sedimented with and had the same buoyant density as viral cores. The composition and physical similarities of nucleoprotein complex and viral cores indicate that complexes may have a role in the assembly of virions.

Amino Acids↗

Properties of nucleoprotein complexes containing replicating polyoma DNA.

Short-lived nucleoprotein complexes (r-py complex) containing replicating polyoma DNA were isolated from infected cells after lysis with Triton X-100. The Triton lysing procedure of Green, Miller, and Hendler (1971) releases most complexes containing supercoiled viral DNA (py complex) from nuclei, but liberates only a portion of r-py complexes. r-py Complexes are associated more strongly with nuclear sites but can be extracted by prolonged incubation of nuclei in lysing solution. Complexes containing replicating polyoma DNA appear to be precursors to stable complexes containing supercoiled DNA. Sedimentation and buoyant density studies indicate that protein is bound to both r-py complexes and py complexes at a ratio of protein to DNA of about 1 to 2/1. Both types of complexes sediment as if the viral DNA is more compact than free DNA and both undergo major reversible configurational changes with increased salt concentration. Changes resulting from enzymatic and chemical treatment indicate that there may be two or more protein components in both r-py complex and py complex. One component is digested by Pronase and trypsin while another is resistant to the enzymes but released by deoxycholate. The abundance and similarity in chemical and physical properties of protein bound to all forms of polyoma DNA suggest that part of the protein molecules may serve in a structural capacity.

Animals↗