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Biomedical subjects

G G Miller

Publications and source records attributed to G G Miller.

At least 127 records · Page 7Linked to original sources
PubMed1973

Mason-Pfizer virus characterization: a similar virus in a human amniotic cell line.

Mason-Pfizer monkey virus (MP-MV) is a RNA virus with an RNA-instructed DNA polymerase first isolated from a rhesus monkey mammary adenocarcinoma in 1970. Until recently, there have been no other isolates. A continuous human amnion cell line, AO, was found to be producing a virus indistinguishable or closely related to the Mason-Pfizer virus as measured by morphological, immunological, and biochemical methods. By thin-section electron microscopy, the extracellular virus particle in AO line is 115 to 130 nm in diameter and has a preformed nucleoid (80 to 90 nm) before budding, properties which are also characteristic of MP-MV. Two proteins of the virus from the AO line were studied. By immunodiffusion, sera which react specifically with MP-MV give a line of identity with virus from the AO line. The AO viral RNA-instructed DNA polymerase purified by phosphocellulose chromatography was specifically inhibited by anti-MP-MV polymerase sera, and the AO cells contained both DNA and RNA sequences related to MP-MV (3)H-DNA. Viruses thus far indistinguishable from MP-MV have also recently been found by others in different human lines, raising again the question of the species of origin of MP-MV. Because the virus in the AO cells cannot be differentiated from MP-MV, we attempted to determine the origin of MP-MV virus by measuring DNA sequences related to MP-MV (3)H-DNA in uninfected human and rhesus monkey cells. The quantity of MP-MV-like DNA sequences in uninfected primate tissues was found to be much lower than the amount of DNA sequences of murine type-B or type-C viruses in uninfected murine tissues. Thus, it was not possible to determine whether the virus produced by AO cells or MP-MV was of human or monkey origin, or both.

Amnion↗
PubMedDate not supplied

DR beta peptides block the antigen-specific response but not the alloresponse of a dual-reactive T-cell clone.

It is generally assumed that alloreactivity and the response to foreign antigens are equivalent T-cell recognition events. We have addressed this issue by examining the antigen presentation of beef insulin by two DR1-restricted human T-clones. One of the clones was dual-reactive and exhibited alloreactivity. By employing 20 synthetic consecutive overlapping peptides representing the entire extracellular (residues 1-198) and intracellular (residues 222-273) parts of the DR2 beta molecule, the effects of each of these peptides on antigen presentation and alloreactivity were examined. The DR1-restricted response to beef insulin by both clones was inhibited by peptides from DR2 beta region 1-25. Other DR2 beta (residues 21-198 en 222-237) or control peptides had no effect. The DR3-associated alloresponse of the dual-reactive clone was not inhibited by any peptide. These observations suggest that recognition of antigen is fundamentally different from allorecognition.

Amino Acid Sequence↗
PubMedDate not supplied

[The HTHIV27 highly productive continuous cell line and its use for solving the fundamental and applied problems of HIV infection].

For the first time the detailed description of continuous cell line HTHIV27, remaining stable for more than 10 years, has been made. The stability of all biological characteristics and high productivity of the strain has made it possible to use it as a HIV producing strain for the construction of a diagnostic test system for the detection of antibodies to HIV. The lysate obtained on the basis of HIV producing cells HTHIV27 has been shown to possess a number of advantages in comparison with the analogous system based on lytically infected cells. On the basis of strain HTHIV27 an in vitro cell system for the analysis of the specific activity of chemotherapeutic preparations intended for the inhibition of HIV has been developed. The use of this newly obtained continuous cell line HTHIV27 has been shown to permit the evaluation of the antiviral activity of compounds, characterized by different molecular mechanisms for the suppression of viral activity.

Anti-HIV Agents↗
PubMedDate not supplied

[The types of virus-specific structures in cells of human origin producing oncornaviruses].

In the cell cytoplasm of human tissue cultures Detroit-6 and AO which produce B type oncorna-virus, two types of virus-specific structures were revealed. Structures of type I were aggregated fibrils of 3 and 6 nm diametre. Structures of type II were nucleoids of A-particles of 70-80 nm diametre. They were rather well separated from cell components by centrifugation sucrose density gradient and repeated centrifugation in the sucrose concentration gradient. Fibrils were found in the density regions of the equilibrium gradient of 1.26 and 1.19 g/cm3, whereas A-particles were detected in the sones of the density of 1.29 and 1.23-124 g/cm3. Their sedimentation coefficients in the sucrose concentration gradients were about 150S and 250S, respectively. From both structure types similar RNA classes were extracted sedimenting in 60S, 45S and 35S regions (sucrose concentration gradient). In addition, 20S RNA was found within the 150S structures. Both structures sa. However, hydridization degree of RNA isolated from both structures with DNA synthesized enzymatically on extracellular various (DNA I) and A-particles (DNA II) was different. With DNA-I, 50-80% of RNA isolated from the type I structures and less than 20% of RNA extracted from the type II structures were hybridized. At the same time, strictly opposite situation (50-80% of RNA II and 20% of RNA I) was observed for DNA-II. These data show lack of genetic connection between these types of cytoplasmic structures and possible role of type I structures in reproduction of oncorna-virus type B.

Cells, Cultured↗
PubMedDate not supplied

[Analysis of the long-term results of contact of human cell cultures with influenza virus].

Influenza A/Hong Kong/1/68 and A/Victoria/35/72 viruses may produce in primarily trypsinized human embryo kidney (HEK) cell culture a chronic form of persistence accompanied by periodic emergence of cytopathic changes arrested by additional medium change. This persistence causes morphological changes in HEK culture manifested in the substitution of epithelial elements by fibroblasts and prolongs the "life" of culture by over 100 days as compared to the controls. The chronic form of persistence of these viruses in human embryo lung diploid cell culture (HELDC) was accompanied by a cytoproliferogenic effect but did not lead to histomorphological changes and did not exert "oncogenic-lide" changes in cell membranes. Inapparent infection with A/Hong Kong/1/68 virus in HELDC did not cause any histomorphological and cytokaryological abnormalities and was accompanied by complete elimination of the virus from the culture. No oncornavirus contamination was found in HELDC cluture either in intact state or after inoculation with influenza virus.

Cell Line↗
PubMedDate not supplied

[2 types of oncornavirus viroins in epithelial cells from human milk].

Virions of types B and C similar to previously known mammal oncornaviruses were found in tissue cultures prepared from epithelial cells sedimented from the milk of a lactating woman with mammary cancer (HEC-31) and the milk of two clinically normal women (HEC-33 and HEC-34). In HEC-33 culture type C particles were predominant quantitatively. All the three milk specimens gave an identical precipitation line with antiserum for the milk of the mammary cancer patient as well as sequences forming molecular hybrids with DNA product of oncornavirus type D. At the same time, no positive immunologic reaction was obtained with the test system for oncornavirus type D from HEp-2 cells.

Antigens, Viral↗
PubMedDate not supplied

[Virus-specific structures in Sendai virus infected Ehrlich ascitic carcinoma cells].

A virus-specific structure representing a ribonucleoprotein (RNP) associated with cell membranes was found in the cytoplasm of Sendai virus-infected cells of Ehrlich ascitic carcinoma. RNP could be separated from the membranes by recentrifugation of this structure in cesium chloride density gradient. In the liquid fraction, a structure with the same buoyant density possessing infectious activity was found. All structural polypeptides of virions with the exception of the membrane protein are found in the composition of the intracellular and extracellular structures.

Animals↗
PubMedDate not supplied

[Influence of mycoplasma on the production of the oncogenic leukemia virus HTLV by HUT-102 T-lymphoblastoid cells].

A suspension culture of human T-lymphoblasts HUT-102 producing type C oncovirus (HTLV) was examined electron microscopically. Control decontaminated HUT-102 cells spontaneously contaminated with M. orale and exogenously infected with M. pneumoniae were examined in ultrathin sections. The variation statistics method demonstrated that in the mycoplasma-infected cells the number of HTLV virions was significantly higher than in control cultures. It is assumed that the increased production of HTLV is due to mycoplasma-induced changes of physico-chemical properties of the cell membrane which facilitate virion budding.

Cell Line↗
PubMedDate not supplied

[Ultrastructural organization of liposomes and isolated glycoproteins of enveloped viruses obtained by using the nonionic detergent MESK].

Materials on comparative ultrastructural analysis of isolated glycoproteins (GP) of influenza, parainfluenza, and Venezuelan equine encephalomyelitis viruses as well as liposomes reconstructed on their basis prepared with the use of MECK, a nonionic detergent, are presented. Original virions, subvirion particles, and isolated GP were characterized by typical morphology and remained intact in highly purified and concentrated suspensions owing to the use of the sparing and effective method of treatment with MECK. After removal of the detergent typical micellar aggregates were shown to form from GP monomers for all three viruses under study. The forming rosettes morphologically and biologically are similar to those isolated from ortho-, paramyxo-, and togaviruses using the Triton X-100 detergent. Stages of liposome formation and interaction with cell membrane were studied electron microscopically. A common feature for liposomes from GP of all the three viruses consisted in the formation of two morphological variants of structural complexes: filaments of various lengths and composition in them of GP and vesicles, the arrays of GP in which were similar or identical to those of viral membrane. Liposomes from Sendai virus GP possessed hemolytic activity, however, their interaction with the cell studied by means of the immunoferritine label occurred not by fusion but apparently as a result of destruction of the cell membrane at the sites of protein F contact with plasmalemma and formation in the latter of defects leading to erythrocyte lysis.

Animals↗