PubMed Health⌕ Search

Biomedical subjects

M P Kiley

Publications and source records attributed to M P Kiley.

At least 37 records · Page 2Linked to original sources
PubMed1984

Hantaan virus: identification of virion proteins.

SDS-PAGE and immunoprecipitation analyses were carried out on the virion and cell-associated proteins of Hantaan virus, the causative agent of haemorrhagic fever with renal syndrome (HFRS). Purified virions have a density of 1.17 g/ml in sucrose, and contain four proteins with molecular weights of 45 000 (45K), 56K, 72K and 200K, confirming recent evidence that the virus is a member of the family Bunyaviridae. Detergent treatment of virions indicates that the 45K protein is the virus nucleoprotein. Both the 72K and the 56K proteins were labelled with [3H]glucosamine and were removed from virions by bromelain treatment, indicating that they are envelope glycoproteins. The 200K protein was found only in [35S]methionine-labelled preparations. By analogy to prototype viruses of the family Bunyaviridae, these proteins were designated N, G1, G2, and L respectively. Three virus-specific proteins (N, G1, G2) were detected in virus-infected cells. These proteins were precipitable by human convalescent serum and by serum of a Rattus norvegicus trapped in the United States. No additional virus proteins were detected in infected cells. These results confirm recent morphological and RNA studies that Hantaan virus is a member of the family Bunyaviridae. Our results also support the suggestion that Hantaan virus be placed in a new genus of Bunyaviridae.

Animals↗
PubMed1983

Evidence for two subtypes of Ebola virus based on oligonucleotide mapping of RNA.

Ebola viruses isolated during outbreaks of acute hemorrhagic fever in Africa from 1976 to 1979 were examined by T1 oligonucleotide mapping of virion RNA. Two Ebola virus subtypes distinguishable by their oligonucleotide patterns were involved in the outbreaks of the disease during this three-year period. The first type was isolated in Zaire in 1976 and again in 1977; the second type caused outbreaks in Sudan in 1976 and again in 1979. Oligonucleotide patterns of the two groups of Ebola viruses (Zaire and Sudan) were remarkably similar within the group but differed between groups by approximately 60 oligonucleotides. We can conclude from this study (1) that the outbreaks of hemorrhagic fever which occurred concurrently in 1976 in Zaire and Sudan were caused by viruses that are genetically distinct; (2) that compared with other RNA viruses there was an unusually high genetic stability among viruses within Zaire and Sudan over two- and three-year periods, respectively; and (3) that the two genetic subtypes probably evolved from a common ancestor since they share common oligonucleotides.

Democratic Republic of the Congo↗
PubMed1983

Comparative analysis of the structural polypeptides of Ebola viruses from Sudan and Zaire.

Polypeptide structural analyses were performed by tryptic peptide mapping to assess the relationship between isolates of Ebola virus obtained in Sudan and Zaire. The results of these analyses indicate (1) that the Sudan and Zaire isolates are unique viral agents, (2) that multiple isolates within each group bear close resemblance to one another, (3) that suggestive evidence exists of conservation of homologous structure in the VP-2 (virion protein no. 2) nucleocapsid proteins of these viruses, and (4) that protein differences between the two Ebola virus subtypes appear to reside in the VP-1 and VP-3 virion polypeptides.

Democratic Republic of the Congo↗
PubMed1983

Development of an immunofluorescence focus assay for Ebola virus.

A 48-h indirect immunofluorescence focus assay for the quantitation of Ebola virus was developed, utilizing HeLa-229 cell monolayers. The dose dependency and the sensitivity of this assay as compared with conventional assays are reported. This indirect immunofluorescence focus assay can be used as a rapid, quantitative test for the detection of Ebola virus, an agent from Africa known to cause hemorrhagic fever.

Antibodies, Viral↗
PubMed1983

Viral haemorrhagic fever surveillance in Kenya, 1980-1981.

Following two cases of Marburg virus disease in Kenya in 1980, viral haemorrhagic fever surveillance was undertaken in western Kenya. Over a 21-month period investigations, including virus isolation attempts, patient and contact serology, visits to areas where suspected cases occurred, interviewing family members and neighbours of suspected cases and following up any additional illnesses in these areas, were carried out. During the study two cases were found that were likely to have been Ebola haemorrhagic fever based on rising antibody titres or positive serology in contacts. Diagnoses of hepatitis A, hepatitis B, malaria, bacterial septicaemia or other causes were arrived at in 24 cases. No diagnosis could be made in 26 instances. 741 human sera were tested for antibodies against Marburg, Ebola, Congo haemorrhagic fever, Rift Valley fever or Lassa fever viruses by indirect fluorescence. Eight sera were positive for Ebola virus antibodies, all of which were from suspected cases or contacts of suspected cases. Two sera were antibody positive to Congo virus and one had antibodies against Rift Valley fever virus. No Marburg or Lassa virus antibodies were detected.

Adolescent↗
PubMed1982

Morphological identification of the agent of Korean haemorrhagic fever (Hantaan virus)as a member of the Bunyaviridae.

Korean haemorrhagic fever (KHF) (Hantaan virus), a rodent-borne viral illness, is an important cause of human disease throughout much of Asia and Eastern Europe. The agent responsible for KHF has not yet been conclusively identified. Plaque-purified KHF virus was concentrated and then banded in a potassium tartrate gradient. Material from the 1.17-1.19 g/ml band was examined by electron microscopy and particles with a morphology identical to that of the family Bunyaviridae were found. The particles were aggregated by KHF serum but not by saline solution or non-immune serum. Identification of KHF virus as a member of the family Bunyaviridae implies a potential for spread by arthropod vectors.

Bunyaviridae↗
PubMed1982

Experimental infection of rhesus monkeys with Lassa virus and a closely related arenavirus, Mozambique virus.

As a model for the pathogenesis of Lassa fever in humans, nine rhesus monkeys were inoculated with Lassa virus. Three monkeys had had a previous asymptomatic experimental infection with Mozambique virus, a closely related arenavirus; these monkeys were protected from illness and viremia and manifested only mild pathologic lesions. The other animals developed severe disease and viremia. At necropsy, hepatocellular necrosis, interstitial pneumonia, a unique pulmonary arteritis, adrenal gland necrosis, encephalitis, and uveitis were prominent pathologic lesions which correlated with the organ titers of virus. One animal infected with Lassa virus developed prolonged viremia, a typical immune response, and sudden onset of lower limb paralysis after recovery; at necropsy chronic proliferative arteritis of the spinal cord, brain, and heart was evident. Similarities and differences in the pathologic lesions in this model and Lassa fever in humans indicate that care must be taken in interpreting the results of experiments concerning immune prophylaxis, pathogenesis, and treatment in rhesus monkeys.

Animals↗
PubMed1980

Ebola virus: identification of virion structural proteins.

Polyacrylamide gel electrophoresis of purified Ebola virus revealed the presence of four major virion structural proteins which we have designated VP1, VP2, VP3 and VP4. Vesicular stomatitis virus (VSV) proteins were used as mol. wt. markers, and the virion proteins were found to have mol. wt. of 125000 (VP1), 104000 (VP2), 40000 (VP3) and 26000 (VP4). VP1 was labelled with glucosamine and is probably a glycoprotein. The density of the Ebola virion was approx. 1.14g/ml in potassium tartrate. Virus nucleocapsids with a density of 1.32g/ml in caesium chloride were released when virions were treated with detergents. Proteins VP2 and VP3 were consistently associated with released nucleocapsids and are probably the major structural nucleocapsid proteins analogous to the N protein of VSV. Protein VP4 was reduced or absent in released nucleocapsids and is probably analogous to the membrane (M) protein of VSV and similar viruses. The glycoprotein (VP1) is larger than the glycoprotein of any known negative-strand RNA virus and is not labelled well with 35S-methionine. VP1 is solubilized by detergent treatment, suggesting that it is a component of the virion spikes and analogous to the G protein of VSV. Our results, in conjunction with analysis of Ebola virion RNA (Regnery et al. 1980), strongly suggest that the virus is a negative-strand RNA virus and, along with marburg virus, may constitute a new taxon within this group.

Capsid↗
PubMed1980

Virion nucleic acid of Ebola virus.

The virion nucleic acid of Ebola virus consists of a single-stranded RNA with a molecular weight of approximately 4.0 x 10(6). The virion RNA did not bind to oligodeoxythymidylic acid-cellulose under conditions known to bind RNAs rich in polyadenylic acid and was not infectious under conditions which yielded infectious RNA from Sindbis virus, suggesting that Ebola virus virion nucleic acid is a negative-stranded RNA.

Ebolavirus↗
PubMed1975

Isolation and characterization of temperature-sensitive mutants of measles virus.

Nine temperature-sensitive (ts) mutants of nonattenuated Edmonston strain measles virus were isolated from wild-type virus which was grown in the presence of 5-fluorouracil. Adsorption, temperature shift, and complementation experiments indicated that all these mutants were restricted at an intracellular stage of infection. However, all the mutants were more rapidly inactivated at 41 C than was wild-type virus, suggesting that the ts product of each mutant either influences or is a structural component of the virus. Three complementation groups were found to be represented among the mutants. Group A contained one mutant and it did not induce synthesis of detectable amounts of viral antigen at the nonpermissive temperature (39 C). Group B consisted of six mutants which did not induce viral antigen synthesis at 39 C and one mutant which did. Group C was represented by one mutant and it induced viral antigen synthesis at 39 C. The two mutants which induced sythesis of viral antigen also induced synthesis of relatively small amounts of virus-specific RNA at 39 C. These mutants, while producing cytoplasmic and nuclear accumulations of viral antigen at 39 C, were restricted in production of syncytia and hemadsorption. All the mutants were less neurovirulent than wild-type virus, as indicated by their inability to produce acute disease in newborn hamsters.

Adsorption↗
PubMed1974

Replication of measles virus: distinct species of short nucleocapsids in cytoplasmic extracts of infected cells.

Cytoplasmic extracts of Vero cells infected with wild-strain Edmonston measles virus were found to contain two and probably three distinct species of nucleocapsids. Species sedimenting at 200 and 110S contained RNA which sedimented at 50 and 16 to 18S, respectively. The third nucleocapsid species which sedimented at 170S was not present in all experiments and was not characterized in detail. Essentially all 200 and 170S, as well as a portion of the 110S, nucleocapsids were membrane associated and probably present in part in cell-associated virions. Five of six plaque purified strains derived from wild-type Edmonston virus produced only 200S nucleocapsids. One of these five plaque-purified strains subsequently produced both 200 and 110S nucleocapsids after being passaged by using undiluted inocula. These results suggest that measles virus may produce distinct classes of defective virus containing short nucleocapsids and subgenomic viral RNA.

Animals↗
PubMed1974

Replication of measles virus: continued synthesis of nucleocapsid RNA and increased synthesis of mRNA in the presence of cycloheximide.

The effect of cycloheximide on virus specific RNA synthesis in Vero cells infected with either wild-strain (Edmonston) or subacute sclerosing panencephalitis strain measles virus was investigated. At 3 days postinfection, cells treated with cycloheximide (2.6 x 10(-4) M) and then exposed to [(3)H]uridine showed a marked increase in labeled virus-specific RNA. A major portion of this incremental labeled RNA was putative viral mRNA which sedimented at 16, 22, and 30S. Five distinct classes of polyribosomes, which were not evident in untreated cells, were found in cycloheximide-treated cells and each contained similar species of virus-specific RNA. Viral nucleocapsid RNA, 50 and 18S, was synthesized and encapsidated in the presence of cycloheximide. The latter observation is in apparent contrast to reports that cycloheximide inhibits replication of RNA of classical paramyxoviruses, and may indicate that mechanisms for replicating RNA of measles virus are different from those for replicating RNA of paramyxoviruses.

Animals↗
PubMed1973

Characterization of influenza virus neuraminidases: peptide changes associated with antigenic divergence between early and late N2 neuraminidases.

Neuraminidases (EC 3.2.1.18) of 1957, 1960, and 1969 influenza virus strains were isolated after proteolytic digestion of viral hemagglutinin. Each neuraminidase was recovered with a final yield of about 15% and had similar specific activities. Immunization of rabbits with the neuraminidases elicited monospecific neuraminidase antibodies, with no antibodies to viral hemagglutinin. Further evidence of purity was the existence of only a single component, about 50,000 daltons in size, when reduced neuraminidase preparations were examined by sodium dodecyl sulfate acrylamide gel electrophoresis. However, storage of neuraminidase in solution resulted in the appearance of slightly smaller degradation products. Preparations of each neuraminidase were denatured under reducing conditions, and exposed sulfhydryl residues were blocked by reaction with (14)C-iodoacetamide. After tryptic digestion, peptide maps were prepared for the neuraminidases, and the (14)C-labeled cysteinyl peptides were then identified by autoradiography. About 20 peptides were present, in agreement with the number predicted from amino acid analysis for neuraminidase subunits of only one type. The 1957 and 1960 neuraminidases exhibited a small antigenic divergence from each other, and maps of their cysteinyl peptides appeared to be identical. The 1969 neuraminidase exhibited considerable antigenic divergence from the other two neuraminidases, and maps of 1969 neuraminidase peptides revealed two major and several minor differences from the other maps. Thus, antigenic divergence between the neuraminidases of Asian and Hong Kong influenza viruses is associated with a small number of changes in the primary structure of the neuraminidase subunit.

Antigens, Viral↗
PubMed1973

Comparative studies of wild-type and "cold-mutant" (temperature-sensitive) influenza viruses: polypeptide synthesis by an Asian (H2N2) strain and its cold-adapted variant.

The structure and replication of a cold-adapted, temperature-sensitive (TS) mutant of an Asian (H2N2) influenza virus was compared with that of its wild-type (WT) parent. Viruses were grown in a chicken kidney cell system, and at the nonpermissive temperature of 40 C, production of infectious TS virus was about 100,000-fold less than at 35 C, in contrast to WT virus. Major structural polypeptides of each virus grown at 35 C were similar, except that the hemagglutinin glycopolypeptide (HA) of the TS virions was slightly more heterogenous than that of WT virions. Synthesis of viral polypeptides was examined by sodium dodecyl sulfate acrylamide gel electrophoresis of pulse-labeled infected cells. This revealed a defect in the synthesis of TS viral hemagglutinin that was most pronounced at the nonpermissive temperature. Other TS viral polypeptides appeared to be synthesized normally at 40 C. A defect in the TS virus hemagglutinin was also indicated by serological studies that demonstrated that TS virus hemagglutinin had lost antigenic sites present on the WT virus. Thus, it is concluded that the virus mutant examined contains lesions in the hemagglutinin gene, although the possibility of additional unrecognized lesions is not excluded.

Adaptation, Biological↗