-
Volume 3,
Issue 1,
1968
Volume 3, Issue 1, 1968
- Articles
-
-
-
A Serological Comparison of Some Iridescent Non-occluded Insect Viruses
More LessSUMMARYTipula iridescent virus and Sericesthis iridescent virus were found to be serologically related by complement-fixation, tube-precipitation and agar-gel diffusion tests. They were unrelated to mosquito iridescent virus when compared by complement fixation. The Tipula virus isolated from Pieris brassicae (L.), Porthetria dispar (L.) and Galleria mellonella (L.) larvae behaved identically in the system tested and were related to, but distinct from Tipula virus particles isolated from Tipula paludosa Meigen larvae. It is suggested that host antigens are incorporated in the Tipula virus particle.
-
-
-
Requirement of Arginine for the Replication of Herpes Virus
More LessSUMMARYArginine in the medium was essential for the replication of herpes simplex virus in RK13 cells. Virus adsorption, penetration and eclipse were not affected. When the medium of arginine-deficient infected cultures was exchanged for complete medium, virus growth resumed with the appearance of a near-synchronous infection. Resumption of virus growth was immediate if the exchange was made in the first 7 days, but if it was later a delay resulted which increased as the duration of deprivation increased. A threshold concentration of arginine was found for herpes virus growth. Virus yield was increased when the arginine concentration was raised over a limited range, but further addition of arginine did not continue to improve the yield. Undialysed calf serum could not be substituted successfully for arginine in herpes virus replication, although it supported cell growth and the replication of vaccinia and coxsackie B3 viruses.
-
-
-
Dark Reactivation of Ultraviolet-irradiated Tobacco Necrosis Virus
More LessSUMMARYSome damage caused in tobacco necrosis virus by u.v. radiation could be repaired in darkness in Chenopodium amaranticolor (dark reactivation) but not in French bean or in tobacco. By contrast, photoreactivation of the irradiated virus was observed in French bean and in tobacco but not in Chenopodium. The kind of damage in u.v.-irradiated virus that is susceptible to repair by photoreactivation appears to be repaired by dark reactivation in Chenopodium. In conditions without evidence of any repair, the quantum yield for inactivation of the nucleic acid inside the virus is about 6.5 × 10−4, and the amount of radiation energy that must be absorbed by the nucleic acid to reduce infectivity to 50% is about 0.3 j/mg.
-
-
-
The Complement-fixation Test for Avian Leukosis
More LessSUMMARYSera from hamsters bearing tumours induced by the Schmidt-Ruppin strain of Rous sarcoma virus (sr-RSV) contain antibodies to the avian leukosis group specific antigen and an antigen of chick origin. The ‘chick embryo antigen’ is found in chick embryos infected and uninfected with avian leukosis viruses and in chicken tumours induced by avian leukosis viruses; for example, Rous sarcoma wing web tumour and plasma from avian myeloblastosis virus infected chickens. The ‘chick embryo antigen’ has been detected in sr-RSV hamster tumour cells. Cultured chick fibroblasts do not contain the ‘chick embryo antigen’ and thus the avian-leukosis group specific antigen can be specifically detected by complement fixation using sr-RSV tumour-bearing hamster sera. This COFAL test is as sensitive as the Rubin interference test (RIF test) and unlike the RIF test will detect all known avian leukosis viruses.
-
-
-
Interferon Production by Semliki Forest Virus Inactivated with Hydroxylamine
More LessSUMMARYThe inactivation of Semliki Forest virus by hydroxylamine was a first-order reaction. The ability of the partially inactivated virus to induce the production of infective virus, virus haemagglutinin, virus-induced RNA synthesis, virus-induced RNA polymerase and interferon were all inactivated with first-order kinetics. It is concluded that functional nucleic acid is essential for interferon production in this system.
-
-
-
Effect of Actinomycin D on Growth of Rubella Virus in Tissue Cultures
More LessSUMMARYMultiplication of rubella virus in primary and continuous-line African green-monkey kidney cells was delayed by addition of low doses of actinomycin D to the culture medium before or at the time of infection. Addition of the drug 2 hr after infection was less effective. However, virus replication became normal after 3 to 8 days, although cellular RNA synthesis in drug-treated control cultures continued to be inhibited.
-
-
-
The Prevention of Early Vaccinia-virus-induced Cytopathic Effects by Inhibition of Protein Synthesis
More LessSUMMARYInfection of LLC-MK 2 cells with the International Health Division strain of vaccinia virus caused rounding of all cells within 2 to 3 hr after infection. Puromycin, at a concentration of 330 µg./ml., completely prevented the early virus-induced cytopathological changes as well as virus multiplication; however, at 33 µg./ml. the compound did not prevent the cytopathic effects of vaccinia virus, in spite of the fact that virus multiplication was largely inhibited. Treatment of cells for 4 hr with puromycin at 330 µg./ml. did not alter the rate of cell division when the compound was removed. When the antibiotic (330 µg./ml.) was removed from infected cultures after a treatment period of 4 hr, virus-induced cell damage began almost immediately after removal and by 1 hr all cells were rounded.
Actinomycin D, 5 µg./ml., also protected the cells from the early vaccinia-virus-induced cytopathic effects. At 0.5 µg./ml., although growth of virus was inhibited, no protection against viral cytopathic effects was observed.
In LLC-MK 2 cells virus-induced morphological damage was not prevented by p-fluorophenylalanine, 5-fluoro-2′-deoxyuridine, and isatin-β-thiosemicarbazone—compounds known to inhibit the reproduction of vaccinia virus. Ultraviolet-irradiated virus, which had lost its infectivity, was still capable of causing early cell damage.
These findings suggest that the early virus-induced cytopathological effects, previously considered the ‘toxic’ effects of the virus, are brought about by the synthesis of virus-induced protein(s).
-
-
-
Comparison of the in vitro Action of Ethidium Chloride on Animal Viruses with that of other Photodyes
More LessSUMMARYFour viruses were irreversibly photosensitized by 4 × 10−5 m-ethidium chloride but not by more dilute solutions. Photosensitization was greatest with vaccinia, pseudorabies, herpes tamarinus and reoviruses, intermediate with western equine encephalitis virus, and least with fowl plague and Newcastle disease viruses. Pseudorabies virus was also inactivated by ethidium chloride at 37° in the dark. The order of susceptibility of the viruses to other dyes varied according to the concentration of dye. Native thymus DNA, but not heated DNA, inhibited the action of ethidium chloride on viruses. Toluidine blue and neutral red were more strongly inhibited by heated DNA than by native DNA, and both DNAs inhibited the action of proflavine to the same extent.
Toluidine blue and proflavine catalysed the degradation of guanine by light in both native and heated thymus DNA. The action of neutral red differed in two respects: at a low ratio of dye to nucleotide molecules, the cytosine of native DNA was also degraded; at a higher ratio, only the guanine of heated DNA was destroyed. There was no effect of ethidium chloride on any of the four bases of DNA.
-
-
-
Genetic Characteristics of Echovirus Type 9 Strains: Selection and Characterization of Variants
More LessSUMMARYUsing different methods of selection, three main types of echovirus type 9 variants were obtained from a single isolate derived from a naturally occurring strain. The three variants pl 88, pl 43 and pl 29 differed in a number of genetic characters as follows: virulence for infant mice (v), capacity to grow at 40° as compared to 36.5° (t), cytopathic effect on epithelial cell lines of human origin (c), inhibition by rhesus monkey serum (m) and protection against heat inactivation by Al ions (a). They also differed in the size and time of appearance of plaques on monkey kidney cell monolayers. The pl 88 variant was mouse-virulent, grew at 40° to the same degree as at 36.5°, was not cytopathogenic on epithelial cell lines of human origin, was not inhibited by normal rhesus monkey serum, not protected by Alions from heat inactivation and produced early large plaques on baboon kidney cell monolayers. Accordingly its genetic markers are v + t + c − m − a −. The genetic markers of the pl 43 variant are v − t − c − m − a −; pl 43 differs from pl 88 only in the v and t markers. Though avirulent for mice, mouse-virulent variants could be selected from it by repeated passage in mice. pl 29 had the characters v −s t − c +. It was distinctly different from both pl 88 and pl 43 by its c marker and produced late and small plaques on baboon kidney cell monolayers. pl 29 was stable in its mouse avirulence and no virulent mutants could be obtained from it by repeated passage in mice. Progeny of pl 29 occurred in two ‘subforms’, m + a + and m − a −. The v −s t − c + m + a + form was identical in these characters with both the quigley and the prototype echovirus type 9, hill strains.
-
-
-
The Neutralization of Rous Sarcoma Virus
More LessSUMMARYThe neutralization of Bryan standard strain Rous sarcoma virus (bs-RSV) followed first-order kinetics after 15 min. incubation. No non-neutralizable fraction was observed when about 105 focus-forming units of representatives of subgroup A and subgroup B viruses were neutralized by homologous sera.
The antigenicity of a strain of bs-RSV was changed by growth on relatively resistant cells. The antigenicity of an A subgroup bs-RSV ‘pseudotype’ was changed by semi-cloning the virus. Both changes of antigenicity were expressed by a change of slope and a reduction of titre on cross-neutralization by the parent virus antiserum.
Antisera to a number of subgroup A leukosis viruses were examined for neutralization of the homologous bs-RSV ‘pseudotype’ and other subgroup A ‘pseudotypes’. The slopes of the neutralization curves for the heterologous systems differed from those of the homologous system. Neutralization indices derived from single points on the neutralization curves, because of the slope differences, did not show consistent cross-neutralization relationships of the viruses tested. When the slope differences were taken into account by comparing areas under the curves, the homologous system had an index at least 20% greater than the heterologous systems.
-
-
-
The Morphological and Biological Effects of Various Antisera on Avian Infectious Bronchitis Virus
More LessSummaryBiologically, homotypic and heterotypic antisera neutralized avian infectious bronchitis virus significantly more when unheated. Morphologically, using the electron microscope technique of negative staining, there was a clear distinction between the effects of homotypic and heterotypic antisera. Heated homotypic antiserum revealed antibody attached only to the projections of the virus, while with unheated homotypic serum heat labile components could be visualized but no basic change could be seen in particle morphology. Heterotypic serum contained antibodies directed both against the projections and the envelope of the virus. In addition, unheated heterotypic antiserum produced holes approximately 100 Å in diameter in the virus membrane, suggesting that a form of virus lysis takes place. Rabbit antiserum prepared against uninfected chick-embryo fibroblasts was able to produce similar holes in the virus envelope and this led us to postulate that the envelope component of avian infectious bronchitis virus is closely related to normal chick host material.
-
-
-
The Adsorption of Phage to Group N Streptococci. The Specificity of Adsorption and the Location of Phage Receptor Substances in Cell-wall and Plasma-membrane Fractions
J. D. Oram and B. ReiterSummaryThe specificities of adsorption and multiplication of phages attacking some strains of lactic streptococci (serological group N) were investigated. At multiplicities of infection (m.o.i.) of 0.1 to 1 p.f.u./coccus, the specificity of adsorption was similar to that of multiplication, but some strains also adsorbed one or more heterologous phages. At m.o.i. ≈ 100 both homologous and heterologous strains of streptococci were lysed from without. The specificity of adsorption to cell walls was the same as to whole cocci and, with the exception of 2 phages, was irreversible at 30°. Three types of phage receptors, with different specificities, were recognized in the cell wall. Extraction of streptococci with lipid-solvents did not affect the adsorption of those phages which were irreversibly adsorbed to cell walls but reduced the adsorption of other phages. The plasma membrane of Streptococcus lactis strain ml 3, but not the cell wall, inactivated phage ml 3 but not heterologous phages in the presence of electrolytes. The plasma membrane of a phage-resistant mutant of this strain did not inactivate phage although it was similar in chemical composition to that of the parent strain.
-
-
-
Association of Tobacco Rattle Virus with Mitochondria
More LessAs part of a study of the way in which tobacco rattle viruses multiply, we have examined the intracellular distribution of the cam isolate (Harrison & Woods, 1966) by means of electron microscopy of thin sections of leaves. The micrographs show a remarkable association between virus particles and mitochondria. Nothing comparable seems to have been reported with other viruses.
Tip leaves, about 2 cm. long, were taken from plants of Nicotiana clevelandii Gray 5 days after their lower leaves were inoculated with the cam isolate. Narrow strips of leaf blade were fixed in 5% (v/v) glutaraldehyde, post-fixed in 0.1% OsO4, stained during dehydration for 16 hr in a saturated solution of uranyl acetate in 70% (v/v) acetone, and embedded in methyl methacrylate + styrene (6:1, v/v). Sections, mostly about 600 Å thick, were cut with a Huxley ultramicrotome, using a glass knife.
-
-
-
Induction of Interferon by Coxiella burneti in Cell Cultures
More LessThe production of interferon or interferon-like inhibitors has been induced by practically every major viral group and by non-viral substances including bacteria, bacterial endotoxins, statolon, phytohaemagglutinins, and the nucleic acids and their derivatives (Ho et al. 1966). Although in vivo induction of an interferon-like inhibitor by Coxiella burneti and Rickettsia prowazeki has been demonstrated by Kazar (1966), the only rickettsial agent reported to induce the production of interferon in cell culture is R. tsutsugamushi (Hopps et al. 1964). The present communication describes the selective induction of interferon in cell cultures by another rickettsia, C. burneti.
A partially purified suspension of the ad (California bovine) strain of Coxiella burneti containing 1 × 106 cell-infecting units/ml., prepared and assayed in accord with procedures described previously (Hahon & Cooke, 1966), was employed for induction of interferon in L cells and McCoy (human origin) cell cultures. Nutrient medium for both cell lines consisted of medium 199 with 0.5% lactalbumin hydrolysate and 10% calf serum.
-
-
-
The Cell to Cell Infection of Respiratory Syncytial Virus in HEp-2 Monolayer Cultures
S. Shigeta, Y. Hinuma, T. Suto and N. IshidaIn general, the properties of respiratory syncytial virus are similar to those of myxoviruses (Chanock, Roizman & Myers, 1957; Hamparian, Hilleman & Ketler, 1963). One of the interesting properties of respiratory syncytial virus infection in vitro is syncytium formation (Jordan, 1962; Kisch, Johnson & Chanock, 1962). It has also been reported that the development of syncytia is influenced by the composition of the medium, the type of host cells (Jordan, 1962) and the incubation temperature (Suto et al. 1965), but it is not inhibited by the presence of virus antibody in the medium (Taylor-Robinson & Doggett, 1963). In the present studies, we report evidence of cell to cell infection with respiratory syncytial virus by successful transfer of virus antigen from infected cells to uninfected cells in the presence of antiviral serum.
The long strain of respiratory syncytial virus supplied by Dr R. M. Chanock (National Institutes of Health, Bethesda, Md, U.S.A.) was used throughout.
-
-
-
Structure and Composition of Xanthomonas pruni Bacteriophage
More LessThis communication deals with the detailed morphology, buoyant density, and chemical composition of Xanthomonas pruni phage XP5 (Mandell & Eisenstark, 1953).
In agreement with earlier descriptions (Thornberry, Eisenstark & Anderson, 1948; Hickman, 1955), electron micrographs revealed that the phage has a polyhedral head, which, via a neck region, connects with a contractile tail. The phage head has a hexagonal outline, 600 Å across opposite apices.
The ‘neck’ connecting the phage head and tail is 80 Å in length, but the exact point at which it connects to head and tail is not clearly defined. The contractile tail is composed of an outer sheath and a central core, terminating with a base plate. Attached to the base plate are six tail spikes, each 100 Å long. In its extended form the sheath is 800 × 200 Å, with 20 cross bands (Pl. 1, fig. 1, 2).
-
-
-
Evidence for the Release of 28 S RNA from Turnip Yellow Mosaic Virus Heated in vitro
More LessThe RNA obtained by heating turnip yellow mosaic virus at about 40° was found by Lyttleton & Matthews (1958) to sediment at 2 to 5 S. Such RNA would almost certainly be extensively broken down and non-infectious, for there is much evidence that whole, infectious RNA from turnip yellow mosaic virus sediments at 28 S (Haselkorn, 1962; Dunn & Hitchborn, 1966). However, Kaper & Steere (1959) found that the RNA obtained from turnip yellow mosaic virus by heating was, in fact, infectious, which suggests that degradation of the RNA is not intrinsic to the process of disruption of the virus by heat. The experiments we describe were made in an effort to obtain further information on this point. In particular, the effect of taking precautions to reduce ribonuclease action on the released RNA was examined.
-
-
-
Spheroplast Formation in Cells of Escherichia coli Infected with a ∅X 174 Type Bacteriophage
More LessLittle is known about the intracellular changes in Escherichia coli infected with bacteriophage ∅X 174 (a tail-less phage with large capsomeres containing single-stranded DNA). Markert & Zillig (1965) found no detectable alteration in the structure of the cell wall in thin sections of lysing cells, the phage progeny being released by local ruptures in the cell envelope (cell wall/plasma membrane complex). The present communication describes a preliminary electron microscopic study of the lysis of E. coli c 2 by phage α 3 (Bradley, 1963), which is similar to ∅X 174 but has a wider host range. The results obtained show a completely different mechanism of lysis. Phage α 3 was grown to a high titre by the confluent lysis of host cells in nine double-agar-layer plates (diameter 15 cm.), which were then extracted with nutrient broth. The resulting suspension was used to infect a broth culture of E. coli c 2 (concentration 1 × 108 bacteria/ml.) at a multiplicity of 20 p.f.u. per bacterium.
-
-
-
Effect of Withdrawal of Arginine and other Amino Acids on the Synthesis of Tumour and Viral Antigens of SV 40 Virus
More LessIn recent years the role of arginine in the replication of certain intranuclear DNA viruses has been well documented. Rouse, Bonifas & Schlesinger (1963) demonstrated that arginine is required for the replication of type 2 adenovirus and Tankersley (1964) and Sharon (1966) showed that it is essential for the multiplication of herpes virus. More recently, Rouse & Schlesinger (1967) showed for type 2 adenovirus, Russell & Becker (1968) for type 5 adenovirus and Becker, Olshevsky & Levitt (1967) for herpes virus that arginine is not required in the early steps of virus replication which include synthesis of viral DNA, but is essential for the production of complete infectious virions.
The purpose of this communication is to report on the effect of depletion in arginine and other amino acids on the replication of SV 40 virus, and on the synthesis of the early ‘T’ antigen (Pope & Rowe, 1964) and late viral coat proteins of this virus in BSC 1 cells.
-
Volumes and issues
-
Volume 106 (2025)
-
Volume 105 (2024)
-
Volume 104 (2023)
-
Volume 103 (2022)
-
Volume 102 (2021)
-
Volume 101 (2020)
-
Volume 100 (2019)
-
Volume 99 (2018)
-
Volume 98 (2017)
-
Volume 97 (2016)
-
Volume 96 (2015)
-
Volume 95 (2014)
-
Volume 94 (2013)
-
Volume 93 (2012)
-
Volume 92 (2011)
-
Volume 91 (2010)
-
Volume 90 (2009)
-
Volume 89 (2008)
-
Volume 88 (2007)
-
Volume 87 (2006)
-
Volume 86 (2005)
-
Volume 85 (2004)
-
Volume 84 (2003)
-
Volume 83 (2002)
-
Volume 82 (2001)
-
Volume 81 (2000)
-
Volume 80 (1999)
-
Volume 79 (1998)
-
Volume 78 (1997)
-
Volume 77 (1996)
-
Volume 76 (1995)
-
Volume 75 (1994)
-
Volume 74 (1993)
-
Volume 73 (1992)
-
Volume 72 (1991)
-
Volume 71 (1990)
-
Volume 70 (1989)
-
Volume 69 (1988)
-
Volume 68 (1987)
-
Volume 67 (1986)
-
Volume 66 (1985)
-
Volume 65 (1984)
-
Volume 64 (1983)
-
Volume 63 (1982)
-
Volume 62 (1982)
-
Volume 61 (1982)
-
Volume 60 (1982)
-
Volume 59 (1982)
-
Volume 58 (1982)
-
Volume 57 (1981)
-
Volume 56 (1981)
-
Volume 55 (1981)
-
Volume 54 (1981)
-
Volume 53 (1981)
-
Volume 52 (1981)
-
Volume 51 (1980)
-
Volume 50 (1980)
-
Volume 49 (1980)
-
Volume 48 (1980)
-
Volume 47 (1980)
-
Volume 46 (1980)
-
Volume 45 (1979)
-
Volume 44 (1979)
-
Volume 43 (1979)
-
Volume 42 (1979)
-
Volume 41 (1978)
-
Volume 40 (1978)
-
Volume 39 (1978)
-
Volume 38 (1978)
-
Volume 37 (1977)
-
Volume 36 (1977)
-
Volume 35 (1977)
-
Volume 34 (1977)
-
Volume 33 (1976)
-
Volume 32 (1976)
-
Volume 31 (1976)
-
Volume 30 (1976)
-
Volume 29 (1975)
-
Volume 28 (1975)
-
Volume 27 (1975)
-
Volume 26 (1975)
-
Volume 25 (1974)
-
Volume 24 (1974)
-
Volume 23 (1974)
-
Volume 22 (1974)
-
Volume 21 (1973)
-
Volume 20 (1973)
-
Volume 19 (1973)
-
Volume 18 (1973)
-
Volume 17 (1972)
-
Volume 16 (1972)
-
Volume 15 (1972)
-
Volume 14 (1972)
-
Volume 13 (1971)
-
Volume 12 (1971)
-
Volume 11 (1971)
-
Volume 10 (1971)
-
Volume 9 (1970)
-
Volume 8 (1970)
-
Volume 7 (1970)
-
Volume 6 (1970)
-
Volume 5 (1969)
-
Volume 4 (1969)
-
Volume 3 (1968)
-
Volume 2 (1968)
-
Volume 1 (1967)
Most Read This Month
