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Biomedical subjects

J B McCormick

Publications and source records attributed to J B McCormick.

At least 127 records · Page 7Linked to original sources
PubMed1985

[Dengue in Burkina Faso (ex-Upper Volta): seasonal epidemics in the urban area of Ouagadougou].

During the rainy season of 1982 30 patients (29 european and 1 voltaic) presented with an intense dengue-like syndrome in Ouagadougou city. 73.3% of these cases possessed anti-flavivirus fluorescent antibodies while 30%, were positive for specific anti-Dengue IgM antibodies. Vero type E 6 cell cultures were used to isolate six strains of Dengue 2 virus; monoclonal antibodies were used for viral identification. These strains constitute the first isolates of human Dengue virus in Upper Volta. Authors present conditions of virus isolations, describe the observed syndrome and discuss the epidemiological interest of this outbreak.

Adolescent↗
PubMed1984

Ribavirin suppresses replication of lymphadenopathy-associated virus in cultures of human adult T lymphocytes.

The in-vitro effect of ribavirin on the replication of lymphadenopathy-associated virus (LAV), one of the prototype viruses aetiologically associated with lymphadenopathy syndrome and acquired immunodeficiency syndrome, was tested. Ribavirin, a nucleoside, suppressed the replication of LAV in cultures of human adult T lymphocytes. Suppression occurred at ribavirin concentrations of 50 micrograms/ml or higher.

Adult↗
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↗
PubMed1984

Physicochemical inactivation of Lassa, Ebola, and Marburg viruses and effect on clinical laboratory analyses.

Clinical specimens from patients infected with Lassa, Ebola, or Marburg virus may present a serious biohazard to laboratory workers. We have examined the effects of heat, alteration of pH, and gamma radiation on these viruses in human blood and on the electrolytes, enzymes, and coagulation factors measured in laboratory tests that are important in the care of an infected patient. Heating serum at 60 degrees C for 1 h reduced high titers of these viruses to noninfectious levels without altering the serum levels of glucose, blood urea nitrogen, and electrolytes. Dilution of blood in 3% acetic acid, diluent for a leukocyte count, inactivated all of these viruses. All of the methods tested for viral inactivation markedly altered certain serum proteins, making these methods unsuitable for samples that are to be tested for certain enzyme levels and coagulation factors.

Blood Chemical Analysis↗
PubMed1983

Circadian variation in the urinary excretion of electrolytes and trace elements in men.

Three-hour urine specimens were collected over a period of 27 hours from 11 healthy adult male subjects. Each specimen was analyzed for Na, K, Ca, Mg, and Zn using atomic absorption spectrophotometry. Each sample was also dialyzed, pH 7.35, and subsequently analyzed for Na, K, P, Ca, Mg, Zn, Fe, Pb, Al, Ni, Cu, Mo, Hg, Cr, Cd, and Mn using a multielemental argon-plasma emission system. The data were evaluated on conventional time plots (chronograms) and as computer-determined "cosinor" plots. A population circadian rhythm with a statistical significance was detected for total Na, K, Ca, and Mg, and for nondialyzable Na, K, P, Ca, Zn, and Mo. For almost every element studied the increase from lowest to highest 3-hour group mean along the 24-hour time scale was more than 100%. The 24-hour excretion of Na, K, Ca, Mg, and Zn appeared in good agreement with the so-called "normals." The nondialyzable levels of Fe, Pb, Al, Ni, Cu, Mo, Hg, Cr, Cd, and Mn were similar to the total urinary excretions reported in the literature.

Adult↗
PubMed1983

Antigenic analysis of strains of Ebola virus: identification of two Ebola virus serotypes.

A sensitive radioimmunoassay has been adapted for Ebola virus antigens and antibodies to them. It uses 125I-labeled staphylococcal protein A and a specially designed filter manifold. The assay is applicable to the sera of humans and to a wide range of animal sera. Virus isolates from two discrete outbreaks of Ebola hemorrhagic fever that occurred in 1976 were shown by this assay to be antigenically distinct. This lack of identity was further confirmed by cross-absorbing antisera to each isolate with antigens of the heterologous virus strain. The advantages of this assay include the use of noninfectious antigens, the requirement for only small quantities of serum, the capability of screening large numbers of sera, the speed of execution, and the objectivity of end point determination.

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

Detection of viral antigens in formalin-fixed specimens by enzyme treatment.

Enzyme treatment (protease or trypsin) was applied to formalin-fixed paraffin-embedded materials and virus-infected cultured cells to detect viral antigens by immunofluorescence. The viral antigens were demonstrated in several organs of autopsy or biopsy cases of which diagnoses had been established by immunofluorescence or virus isolation using frozen materials, or suspected on the basis of serology and/or histopathological findings. These included herpes simplex, varicella-zoster, cytomegalo, subacute sclerosing panencephalitis, progressive multifocal leukoencephalopathy, Japanese B encephalitis, measles, acute hemorrhagic conjunctivitis, Lassa and Korean hemorrhagic fever. Antigen could be recovered also in virus-infected cells (herpes simplex, measles, Lassa, Ebola, Marburg, Rift Valley, Congo and Korean Hemorrhagic fever) by enzyme treatment after periods of formalin fixation of four weeks and storage of three months. In herpes simplex virus-infected mouse brain, antigen was detected after fixation for three months in formalin.

Adolescent↗
PubMed1983

Immunofluorescence studies of disseminated Hantaan virus infection of suckling mice.

Hantaan virus, the etiological agent of Korean hemorrhagic fever, was inoculated intracerebrally or intraperitoneally into suckling mice, and the course of the infection was followed by infectivity titration and immunofluorescence studies. Mice became ill and were moribund by 13 to 14 days postinfection. In mice inoculated either intracerebrally or intraperitoneally, virus antigen was present in brain, heart, lungs, liver, and kidney. Less consistently, specific fluorescence was observed in spleen, pituitary gland, thymus, lymph nodes, adrenal, pancreas, salivary glands, trigeminal ganglia, adipose tissue, intestine, and muscle. In all of these tissues, the primary target of infection was the capillary endothelium. In mice inoculated intracerebrally, virus antigen was present mainly in choroid plexus, hippocampal nuclei, and meninges, but in mice inoculated intraperitoneally, central nervous system infection was marked by antigen accumulation in cortical nuclei and thalamus.

Animals↗