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Biomedical subjects

P M Howley

Publications and source records attributed to P M Howley.

177 records · Page 10Linked to original sources
PubMed1978

Characterization of K virus and its comparison with polyoma virus.

The antigenic relationship between the two murine papovaviruses, K virus and polyoma virus, was examined by serological techniques to determine whether they shared any antigenic components. No cross-reactivity was found associated with the viral (V) antigens by the indirect immunofluorescence, neutralization, or hemagglutination-inhibition tests. The tumor (T) antigens expressed in transformed cells or cells productively infected by either K or polyoma virus did not cross-react by indirect immunofluorescence. An antigenic relationship was detected, however, among the late proteins of K virus, polyoma virus, simian virus 40, and the human papovavirus BKV, when tested with either hyperimmune sera prepared against polyoma virus and simian virus 40 or sera prepared against disrupted virions. The nucleic acids of K and polyoma viruses were compared by agarose gel electrophoresis and restriction endonuclease analysis. No nucleotide sequence homology between the genomes of these two viruses was detectable by DNA-DNA hybridization techniques under stringent conditions. The genome of K virus was found to be slightly smaller than that of polyoma virus, and the cleavage patterns of the viral DNAs with six restriction endonucleases were different. These findings indicate that there is little relationship between these two murine papovaviruses.

Antigens, Viral↗
PubMed1977

Endocrine studies in cystinosis: compensated primary hypothyroidism.

Children with nephropathic cystinosis exhibit marked growth retardation. Improved medical management and renal transplantation have increased their life expectancy beyond the second decade. We have studied endocrine function in seven patients with cystinosis and reviewed autopsy findings of four patients and medical records of 24 others. One 10-year-old boy was overtly hypothyroid. The six other patients had normal studies of peripheral thyroid function but two had borderline and two had frankly elevated serum TSH levels. Stimulation tests of cortisol and growth hormone secretion and basal levels of serum NSILA-s were normal. Postmortem histology of the thyroid glands revealed extensive destruction and infiltration of the epithelium with cystine crystals. Despite the presence of cystine crystals in other endocrine tissues, there was no destruction of epithelium in glands other than in the thyroid. We conclude that in nephropathic cystinosis "compensated" primary hypothyroidism occurs frequently and early and may be diagnosed by measurement of serum TSH concentrations.

Child↗
PubMed1977

Isolation of simian virus 40 from rhesus monkeys (Macaca mulatta) with spontaneous progressive multifocal leukoencephalopathy.

Isolates of virus from the brain tissue of two naturally occurring cases of progressive multifocal leukoencephalopathy in rhesus monkeys (Macaca mulatta) have been characterized. Both isolates were demonstrated to be simian virus 40 (SV40) by serological tests and analysis of cleavage fragments of viral deoxyribonucleic acid produced by restriction endonuclease from Haemophilus influenzae. SV40 virions and the nonvirion T antigen were demonstrated in the brain lesions of one monkey by the fluorescent antibody staining technique. SV40 was not demonstrated in the brain of normal rhesus monkeys from the same colony with use of the same methods of viral isolation or demonstration of antigen.

Animals↗
PubMed1977

Oncogenicity of a nude mouse cell line transformed by a human papovavirus.

Primary cultures of NIH nude mouse (nu/nu) kidney cells were transformed with a human papovavirus (MMV). The transformed cell line expressed T-antigen, and MMV DNA was found to be associated with the cell DNA. When NIH nu/nu mice were inoculated with the transformed cells, they developed tumors at the injection site but failed to generate detectable levels of T-antibody. A control group of nu/+ littermates rejected the tumor inoculum but mounted an antibody response to T-antigen. It was proposed that nude mouse cells may be a suitable system to test oncogenicity of in vitro transformed cells.

Animals↗
PubMed1977

Uniform representation of the human papovavirus BK genome in transformed hamster cells.

The DNA of three cloned lines of hamster kidney cells transformed by human papovavirus BK DNA was examined by reassociation kinetics for viral sequences and found to contain 2.7 to 5.3 equivalents of viral DNA per diploid genome. In the one line examined with the four R-HindIII fragments of the human papovavirus BK genome, the entire viral genome was uniformly represented.

Animals↗
PubMed1976

Genome localization of simian virus 40 RNA species.

The topographical locations on the simian virus 40 (SV40) genome of the templates for virus-specific RNA species present late in the lytic infection were determined by RNA-DNA hybridization experiments with the Hind restriction enzyme fragments. Two classes of late virus-specific cytoplasmic mRNA's can be separated on the basis of either sedimentation properties in neutral sucrose or electrophoretic mobility in polyacrylamide gels. In the 16S class, two species of RNA were identified by hybridization experiments. One of these species was complementary to sequences of the early template on the minus (E) strand (0.175 to 0.655 map units), and the other more abundant species was complementary to sequences present in the late template on the plus (L) strand (0.655 to 0.175 map units). In addition two species were detected in the 16S class of late cytoplasmic virus-specific mRNA. One of these species was the major late RNA detected and consisted of a polyadenylated transcript complementary to the plus (L) DNA strands of Hind fragments K, F, J, and G (0.945 to 0.175 map units). This species appears to specify the major capsid protein (VP1). A less abundant nonpolyadenylated 16S RNA species complementary to the plus (L) strands of Hind fragments C, D, and E (0.655 to 0.945 map units) may result from post-transcriptional processing or nonspecific degradation of the 19S viral RNA complementary to the plus (L) strand.

Base Sequence↗
PubMed1975

Homology and relationship between the genomes of papovaviruses, BK virus and simian virus 40.

A number of hybridization techniques have been used to assess the homology between the genomes of BK virus (BKV) and simian virus 40 (SV40). A noncontiguous set of homologous sequences has been localized primarily within the late region of the SV40 genome, and these sequences presumably account for the cross-reaction between V-antigens of the two viruses. The reason for the relatively strong crossreaction between SV40 and BKV T-antigens is still unclear. The sequence homology and similarity in genomic organization suggest a close relationship between these papovaviruses.

BK Virus↗
PubMed1975

Characterization of human papovavirus BK DNA.

The DNA of the BK virus (BKV) human papovavirus was found to be heterogeneous, consisting of at least four discrete species of DNA. Only the largest of these four species, BKV DNA (i), which has a molecular weight calculated to be 96% that of simian virus 40 (SV40) DNA, was infectious. Homogeneous preparations of BKV DNA were obtained, however, from virions purified after low multiplicity infections of human embryonic kidney cells. BKV DNA (i) was shown to contain a single R-Eco RI and four R-Hind cleavage sites. The R-Eco RI site was localized in the largest R-Hind cleavage fragment. Radiolabeled BKV DNA reassociated slightly faster than SV40 DNA; 20 to 30% polynucleotide sequence homology was demonstrated between the genomes of BKV and SV40 when the reaction was monitored by chromatography on hydroxyapatite.

Animals↗
PubMed1975

Physical map of the BK virus genome.

Two new human papovavirus isolates (JMV and MMV) from the urines of patients with Wiskott-Aldrich syndrome were morphologically and serologically identical to BK virus (BKV). The genomes of these two new isolates were found to be indistinguishable from prototype BKV DNA in a variety of nucleic acid hybridization experiments. Like BKV DNA, JMV and MMV DNAs share approximately 20% of their polynucleotide sequences with simian virus 40 DNA. The genome of JMV was indistinguishable from that of BKV by restriction endonuclease analysis; MMV DNA contained three instead of four R-Hind cleavage sites and one rather than no R-HpaII cleavage sites. Physical maps of the BKV and MMV genomes were constructed using restriction endonucleases, and these maps were oriented to the map of simian virus 40 DNA.

BK Virus↗
PubMedDate not supplied

Dissociation of transforming and trans-activation functions for bovine papillomavirus type 1.

It has been shown that genetic information encoded by the 3' open reading frames (ORFs), E2, E3, E4 and E5, of bovine papillomavirus type 1 (BPV-1), is sufficient to induce cellular transformation of certain mouse cells. The product of the E2 ORF has further been shown to be responsible for the trans-activation of a transcriptional regulatory element located in the noncoding region (NCR) of the BPV-1 genome. To examine whether or not the E2 trans-activation function is encoded by the same gene that encodes the 3' ORF viral transformation function, we have now analysed the expression of the trans-activation function in series of mouse C127 cells transformed by BPV-1 deletion mutants. In addition, using mutated complementary DNA clones generated by the insertion of a premature translational termination linker into different sites of a BPV-1 cDNA clone containing the 3' ORFs intact, we demonstrate that transformation and transcriptional trans-activation functions can be dissociated and that they map respectively to the E5 and E2 ORFs.

Acetyltransferases↗