Showing papers in "Archives of Virology in 1975"
TL;DR: Application of binary ethylenimine in the preparation of foot-and-mouth disease vaccines considerably reduces the potential danger associated with handling pure ethylnimine and other aziridines.
Abstract: Foot-and-mouth disease virus was inactivated with binary ethylenimine formed apart from or directly in the virus suspension by the cyclization of 2-bromoethylamine hydrobromide or 2-chloroethylamine hydrochloride under alkaline conditions. The inactivation rates with binary ethylenimine prepared apart from the virus suspension in dilute sodium hydroxide with either 2-bromoethylamine hydrobromide or 2-chlorethylamine hydrochloride were higher than with pure ethylenimine. When binary ethylenime was prepared directly in the virus suspension only 2-bromoethylamine hydrobromide gave acceptable inactivation rates. The reduced inactivation rates for binary ethylenimine directly prepared in the virus suspension are due to the different cyclization rates of 2-bromoethylamine hydrobromide and 2-chloroethylamine hydrochloride and to the interference of bicarbonate in the cyclization reaction. The complement fixing antigen of foot-and-mouth disease virus was not affected by binary ethylenimine inactivation. Vaccines prepared with foot-and-mouth disease virus inactivated by binary ethylenimine were comparable in their immunogenicity to vaccines prepared with ethylenimine or N-acetylethylenimine used as inactivants. Application of binary ethylenimine in the preparation of foot-and-mouth disease vaccines considerably reduces the potential danger associated with handling pure ethylenimine and other aziridines.
202 citations
TL;DR: Findings strongly suggest that Akabane virus is the etiological agent of the outbreaks in Japan and further studies are needed, particularly isolation of the virus, demonstration of infection with the virus in lesions by immunofluorescence and production of intrauterine infection by experimental infection of pregnant cows.
Abstract: In the outbreak of abortions, premature births, stillbirths and congenital arthrogryposis-hydranencephaly (AH) syndrome in Japan during the summer through winter of 1972-73 and 1973-74, precolostral sera from calves with congenital AH syndrome and normal calves were tested for neutralizing antibodies against some arboviruses, i.e. Akabane, Aino, Getah and Japanese encephalitis (JE) viruses. The incidence of antibody for Akabane virus was very high in calves with AH syndrome (49/59 or 83 per cent) as compared with normal calves (3/11 or 27 per cent), indicating an intimate correlation between the AH syndrome and precolostral anti-Akabane antibody. Three stillborn fetuses also had anti-Akabane antibody. On the other hand, no precolostral serum antibody for the other viruses was detected in any of the calves tested. The mothers of these calves, normal and with AH syndrome, had anti-Akabane antibody in high percentages (44/52 or 85 per cent and 7/8 or 88 per cent), whereas a few of the mothers had antibodies for the other viruses. Serological surveys indicate a wide dissemination of Akabane virus in epizootic areas during the summer months of 1972 and 1973. Thus, 8 groups of cattle in epizootic areas showed high rates of seroconversion for Akabane virus during the 1972 or 1973 summer. Very high incidences of Akabane antibody were shown among cattle in epizootic areas but extremely low incidences in near-by non-epizootic areas. The geographic distribution of anti-Akabane antibody among cattle throughout the country in the 1973 spring generally agrees with the pattern of case distribution in the 1972--73 outbreak. All these findings strongly suggest that Akabane virus is the etiological agent of the outbreaks. Further studies are needed, particularly isolation of the virus, demonstration of infection with the virus in lesions by immunofluroescence and production of intrauterine infection by experimental infection of pregnant cows.
114 citations
TL;DR: An over production of viral coded materials, including non-polygonal membranes seems to be an important feature of the replicative cycle of ASFV in this cell system.
Abstract: Cultures from pig bone marrow cells were infected with ASFV and the replication cycle was studied. In the cytoplasmic replication areas there are a differentiation of membrane segments. Some of them are polygonal, which give rise to virus particles. An over production of viral coded materials, including non-polygonal membranes seems to be an important feature of the replicative cycle of ASFV in this cell system. Viruses are released enveloped with a cellular membrane. Paracrystalline arrays of viruses are seldom seen in the cytoplasm. At no time did we see viruses in the nucleus. Infected cells showed marked cytopathic effect, beginning at early times post infection.
72 citations
TL;DR: Serological studies indicate that bovine RS virus is widespread in Iowa cattle and that it is involved in some outbreaks of respiratory disease.
Abstract: The isolation and characterization of a bovine respiratory syncytial (RS) virus is described. Serological studies indicate that bovine RS virus is widespread in Iowa cattle and that it is involved in some outbreaks of respiratory disease. Experimental infection in calves indicates that the virus can cause illness in calves, particularly those with serum neutralizing antibody.
71 citations
TL;DR: Most characteristical changes were dermal edema and spongiosis with mononuclear cell infiltration as well as the detection of measle virus-like microtubular structures (nucleocapsids) in the endothelium of dermal capillaries.
Abstract: Measles skin lesions were studied by light and electron microscopy. In the epidermis multinucleated giant cells were observed just beneath the hypertrophic horney layer at the maximum stage of rash; they were believed to result by an abnormal process of hyper- or parakeratosis. Neither typical inclusions nor viral nucleocapsids could be detected in any part of the epidermal layer. Most characteristical changes were dermal edema and spongiosis with mononuclear cell infiltration as well as the detection of measle virus-like microtubular structures (nucleocapsids) in the endothelium of dermal capillaries. Is is assumed that measles exanthema is a manifestation of an Arthus reaction elicited by viral antigen in the endothelium of dermal capillaries.
71 citations
TL;DR: Seven-day-old embryonated hen eggs were infected with African Horse Sickness virus by the yolk sac and intravenous routes, and Culicoides variipennis midges which took a blood meal from infected eggs became infected with virus, and after 7 days at 26°–27° C transmitted virus to uninfected eggs.
Abstract: Seven-day-old embryonated hen eggs were infected with African Horse Sickness virus by the yolk sac and intravenous routes. Virus reached a high titre in the blood of infected embryos. Culicoides variipennis midges which took a blood meal from infected eggs became infected with virus, and after 7 days at 26 degrees - 27 degrees C transmitted African Horse Sickness virus to uninfected eggs. C. variipennis may therefore be considered a biological vector of African Horse Sickness virus in the laboratory.
51 citations
47 citations
TL;DR: The greater part of the examined NDV strains were found, irrespective of virulence properties, to be thermostable, since the loss of infectivity titre did not exceed 2 logarithmic orders after exposure at 50° C for 60 minutes.
Abstract: The thermal inactivation rate constant for infectivity of a total of 24 Newcastle disease virus (NDV) strains was determined at 50° and 56° C. The greater part of the examined NDV strains were found, irrespective of virulence properties, to be thermostable, since the loss of infectivity titre did not exceed 2 logarithmic orders after exposure at 50° C for 60 minutes. Thermostable (I+) and thermolabile (I−) strains with respect to infectivity were uniformly encountered among the 12 avirulent (lentogenic) and 10 fully virulent (velogenic) strains studied. Strains with both heat stable (Ha+) and heat labile (Ha−) haemagglutinin were found in the lentogenic group, whereas haemagglutinins of all examined velogenic strains were heat stable. On the basis of I/Ha character,i.e. combination of thermosensitivity of infectivity and haemagglutinin, all examined strains could be classified into one of three categories: I−Ha− (8 lentogenic strains), I+Ha+ (4 lentogenic and 7 velogenic strains) and I−Ha+ (2 mesogenic and 3 velogenic strains). The possible fourth combination, I+Ha−, was not encountered among the strains studied. Determination of the I/Ha character may be helpful in clarifying the origin of a lentogenic NDV strain.
46 citations
TL;DR: A virus was isolated from a group of feedlot cattle with acute respiratory disease that was characterized by physicochemical methods as an adenovirus and identified serologically as a bovine adenOVirus type 3.
Abstract: A virus was isolated from a group of feedlot cattle with acute respiratory disease that was characterized by physicochemical methods as an adenovirus and identified serologically as a bovine adenovirus type 3. Intratracheal inoculation of three 4 month old colostrum deprived calves resulted in pyrexia, hyperpnea, dyspnea, anorexia and in one animal a mild diarrhea.
43 citations
TL;DR: Neutralizing activity against d Dengue virus types 1–4 was observed in milk samples from 5 non-immune and 29 dengue immune women and did not decrease over a period of ten months after delivery.
Abstract: Neutralizing activity against dengue virus types 1--4 was observed in milk samples from 5 non-immune and 29 dengue immune women. Anti-dengue activity in milk and colostrum was found only in the lipid component. The inhibitory activity is directed against the virus and not cell surfaces. When immunoglobulin types IgM,IgA, IgG were isolated from colostrum from dengue immune women, no antibody activity was found. Anti-dengue activity in human milk did not decrease over a period of ten months after delivery.
43 citations
TL;DR: Type 9 African horse-sickness virus multiplied to a high titre in both Culicoides nubeculosus and C. variipennis after intrathoracic inoculation and after oral ingestion, and it is suggested that C. Variipennis can act as a biological vector of African horse's sickness virus.
Abstract: Type 9 African horse-sickness virus multiplied to a high titre in bothCulicoides nubeculosus andC. variipennis after intrathoracic inoculation and inC. variipennis after oral ingestion. The orally infectedC. variipennis were able to transmit the virus by biting after 13 days incubation at 26° C but not after 6 days incubation. Intrathoracically inoculatedC. variipennis were able to transmit the virus after 4 days incubation. It is suggested thatC. variipennis can act as a biological vector of African horse-sickness virus.
TL;DR: The influence of pH on the growth of transmissible gastroenteritis virus (TGEV) in adult pig thyroid cell culture, and on the stability of the virus was studied.
Abstract: The influence of pH on the growth of transmissible gastroenteritis virus (TGEV) in adult pig thyroid cell culture, and on the stability of the virus was studied. At pH 6.5 the yield of virus was 10 fold higher than cultures held at pH 7.2 and 100 fold higher than those at pH 8.0. The adsorption, penetration and uncoating steps of the viral replicative cycle were shown to be unaffected by pH variation. Synthesis of TGEV RNA during the first 12 hours post infection was found to be unaffected by pH variation between the range 6.5–8.0. After 12 hours breakdown of this RNA appeared to occur in cultures held at pH 7.2 and 8.0 but not at pH 6.5.
TL;DR: It is suggested that prostaglandins exert an inhibitory effect on the replication phase of the virus by influencing the growth of the WISH cells.
Abstract: Influence of prostaglandins E2 (PGE2) and F2α (PGF2α) on multiplication of myxovirus parainfluenza 3 was investigated. At concentrations of 0.01–1 µg/ml prostaglandins had no direct cytotoxic effects. PGE2 and PGF2α inhibited multiplication of parainfluenza 3 virus at concentrations 0.1–10 µg/ml. The inhibitory effect was most pronounced when the prostaglandins were added to medium for the whole period of virus multiplication (48 hours) while little or no effect was found when prostaglandins were added before virus inoculation or for 2 hours after infection. It is suggested that prostaglandins exert an inhibitory effect on the replication phase of the virus by influencing the growth of the WISH cells.
TL;DR: Biologically, the purified rubella virus preparation showed high infectivity, a high hemagglutination titre and a weak neuraminidase activity under defined conditions.
Abstract: A simple and reproducible method for the production of purified rubella virus is described. Purified virus was subjected to morphological and chemical analysis. The virus particles were rather pleomorphic (60 nm diameter), sometimes with one or more peripheral protrusions. The viral surface, revealed by negative staining, was composed of spikes 6 nm long, featuring enlarged ends.
TL;DR: Two virus strains which had been suspected to be the etiological agents of infectious bursitis (Gumboro disease) and of inclusion body hepatitis of chickens were characterized by their morphology, their peptide composition and the segmented genome of their double-stranded RNA to be typical reoviruses.
Abstract: Two virus strains which had been suspected to be the etiological agents of infectious bursitis (Gumboro disease) and of inclusion body hepatitis of chickens were characterized by their morphology, their peptide composition and the segmented genome of their double-stranded RNA to be typical reoviruses. Although the 2 avian strains did not clearly differ in their serological behaviour, the size of some of their RNA segments were not identical. Both strains replicated in tissue cultures prepared from the chorioallantoic membrane of embryonated eggs with growth characteristics of reoviruses.
TL;DR: The finding of accumulations of virus particles in association with smooth membranes is of importance in respect of the recent biochemical evidence of poliovirus assembly in relation to smooth membranes.
Abstract: An electron microscopic study of kitten kidney cells infected with a feline calicivirus (a member of the family Picornaviridae) has been carried out Although cells appeared to be synchronised by the light microscope, electron microscopic changes were extremely variable The first observable and consistent changes occurred in the nucleus followed by the formation of membrane bound vesicles in the cytoplasm A variety of arrangements of virus particle accumulation were observed in infected cells These included crystalline arrays, membranous cisternae and accumulation of particles in fine fibrillar material The finding of accumulations of virus particles in association with smooth membranes is of importance in respect of the recent biochemical evidence of poliovirus assembly in relation to smooth membranes
TL;DR: Avian infectious bronchitis virus grownin ovo was purified by differential centrifugation and isopycnic sedimentation in density gradients and found to comprise up to sixteen polypeptides, four of which were glycopeptides.
Abstract: Avian infectious bronchitis virus grownin ovo was purified by differential centrifugation and isopycnic sedimentation in density gradients. The purified virus was analysed by SDS polyacrylamide gel electrophoresis and found to comprise up to sixteen polypeptides, four of which were glycopeptides. Bromelain treatment of the particles removed three polypeptides and two glycopeptides.
TL;DR: A poxvirus isolated from the respiratory tract of raccoons in a forest and swamp area near Aberdeen, Maryland, was characterized by biological, serological, and biophysical methods and was shown to be related to the vaccinia-variola subgroup by serological andBiophysical methods.
Abstract: A poxvirus isolated from the respiratory tract of raccoons in a forest and swamp area near Aberdeen, Maryland, was characterized by biological, serological, and biophysical methods. The virus was shown to be related to the vaccinia-variola subgroup by serological and biophysical methods, but measurably different from the other viruses of this group by biological methods. It causes flaccid paralysis in 1-day-old suckling mice and does not grow well on CAM after two or three passages.
TL;DR: Antiherpetic activity of AME was demonstrated inin vitro inactivation tests and in cell culture systems against herpes zoster and five strains of herpes simplex virus.
Abstract: Antiherpetic activity of AME was demonstrated inin vitro inactivation tests and in cell culture systems against herpes zoster and five strains of herpes simplex virus.
TL;DR: Negatively-stained preparations revealed morphological similarities with both the bluetongue virus group, and the virus of infectious pancreatic necrosis of trout, which indicated that the small particle found in such preparations is a degradation product of the large particle.
Abstract: The virus of infectious bursal disease of chickens was studied by immune electron microscopy. Negatively-stained preparations revealed morphological similarities with both the bluetongue virus group, and the virus of infectious pancreatic necrosis of trout. Results indicated that the small particle found in such preparations is a degradation product of the large particle.
TL;DR: Serologic evidence and viral isolations seem to indicate that polyomaviruses (BK type) might cause a chronic infection in humans.
Abstract: Ten renal transplant recipients showing a significant increase in human polyomavirus antibodies, indicative of an acute infection, were followed up serologically over periods ranging from two months to more than two years. Fifty-four serum specimens were available for the study and they were tested by both haemagglutination-inhibition and complement-fixation. Polyomavirus antigens were prepared from the BK and SV 40-like strains of polyomaviruses, and from the SV 40 virus. One strain of polyomavirus, related to the BK strain, was isolated from the urine of one of these patients. Two other BK strains were recovered from the urine and kidney, respectively, of transplant recipients not included in this study. Sera of these two patients were not obtained until the transplantation was made; they were already highly positive for polyomavirus antibodies, precluding the demonstration of an increase in antibody titer. Serologic results have shown that HAI antibodies persist at high titers throughout the observation period. This persistence ranged from two to four months (four cases), seven to eleven months (three cases) and thirteen to twenty months (three cases). In none of the cases could a decrease of high titer be demonstrated. Moreover, density gradient studies have shown that specific IgM antibodies also tend to persist over many months. Similar serologic results were obtained in complement-fixation tests with a BK antigen. Titers were at least 1 in 30 in the study group, but were not observed among healthy blood donors. All sera were uniformly negative for SV 40 and SV 40-like antigens. One polyomavirus isolation was successful from urine obtained six months after initial serologic evidence for a polyomavirus infection. The other two viruses were isolated from materials taken four and seven months after first detection of polyomavirus antibodies at high titer. Both serologic evidence and viral isolations seem to indicate that polyomaviruses (BK type) might cause a chronic infection in humans.
TL;DR: Suitable dilutions of HSV preparations inoculated into microcultures of confluent monolayers of human foreskin or Vero cells, in individual wells of plastic “microplates”, induced viral cytopathic effects that resulted from the infection of the cultures by single virus particles.
Abstract: Suitable dilutions of herpes simplex virus (HSV) preparations inoculated into microcultures of confluent monolayers of human foreskin or Vero cells, in individual wells of plastic “microplates”, induced viral cytopathic effects that resulted from the infection of the cultures by single virus particles. The clonal nature of the viral progeny in isolated wells was supported by visual control over the development of viral foci and by statistical analysis. The method has the advantage of speed and economy, while it also yields a large primary clonal virus stock. HSV clones resistant to phosphonoacetic acid (PAA) and 5-iodo-2′-deoxyuridine (IUdR) could be readily isolated by the described technique.
TL;DR: A hepatotropic variant of avian influenza virus A/Turkey/England 63 (Hav 1, Nav 3) was selected by serial passages in mouse liver by establishing adaptation to this organ and was found to improve during further passages as shown by increasing rates of replication in livers of ICR mice.
Abstract: A hepatotropic variant of avian influenza virus A/Turkey/England 63 (Hav 1, Nav 3) was selected by serial passages in mouse liver. Adaptation to this organ was established after 13in vivo passages and was found to improve during further passages as shown by increasing rates of replication in livers of ICR mice. The mutant virus finally selected was stable and differed from the original virus mainly in lethality upon intraperitoneal injection in mice, in its ability to grow to high titers in livers of susceptible animals and in plaque morphology in chick embryo fibroblasts. No differences were detected in hemagglutination inhibition and neutralization by standard mouse antisera. Pathogenicity for the liver was independent of the route of inoculation, included other laboratory animals sensitive to influenza virus and could be inhibited by amantadine. Fatal hepatitis in 50 per cent of susceptible mice by the intraperitoneal route required from 10 to 20 EID50. Pathological changes consisted of severe necrosis of liver parenchyma accompanied by release of F antigen into the serum and were apparently due to virus replication in hepatic cells as evidenced by immunofluorescence.
TL;DR: The growth of avian infectious bronchitis virus (IBV) in chick kidney cells at different pH values in the range 6.0–9.0 demonstrated that although the virus was released at a much faster rate at the higher pH values the titre tended to drop more quickly.
Abstract: The growth of avian infectious bronchitis virus (IBV) in chick kidney cells at different pH values in the range 6.0-9.0 demonstrated that although the virus was released at a much faster rate at the higher pH values the titre tended to drop more quickly. At the acid pH values the virus was released more slowly but reached a maximum titre similar to that at the higher pH values and showed only minimum reduction in infectivity up to 49 hours post inoculation. The stability of virus in tissue culture medium was shown to be directly related to pH 6.0-8.0, being more stable at the acid pH values. The degree of cytopathogenicity induced in chick kidney cells following infection with IBV was directly related to the pH at which the cells were incubated, occurring earlier and more extensively in cells at the higher pH values. Cell macromolecule synthesis in chick kidney cells was inhibited following infection with IBV and was apparently due to cell damage and death.
TL;DR: The immunofluorescent, immunoperoxidase, and hemadsorption cell-counting techniques were quantitatively evaluated for assessing interferon activity and were comparable in sensitivity, precision, and reproducibility.
Abstract: The immunofluorescent, immunoperoxidase, and hemadsorption cell-counting techniques were quantitatively evaluated for assessing interferon activity. The three assays exhibited parallel dose-responses and were comparable in sensitivity, precision, and reproducibility.
TL;DR: It was established that nuclear chromatin undergoes profound changes consisting of condensation usually into a single, rounded, central mass.
Abstract: The ultrastructural changes in a feline embryo continuous cell line infected with feline calicivirus at a multiplicity of infection of approximately 1 were studied. Virus was found only in the cytoplasm and was observed as single particles, as extensive, non-regular accumulations, as paracrystalline arrays, and as single or multiple linear arrays associated with microfibrils. Mature virus particles were readily distinguished from ribosomes in that they were larger (35 nm diameter) and consisted of a central, electron-dense core 20 nm diameter surrounded by a less electron-dense coat.
TL;DR: Analysis of the nucleic acid of infectious bronchitis virus by SDS polyacrylamide gel electrophoresis revealed an RNA of molecular weight 9.0×106 Daltons that was shown to have a sedimentation coefficient of 50.0%.
Abstract: Analysis of the nucleic acid of infectious bronchitis virus by SDS polyacrylamide gel electrophoresis revealed an RNA of molecular weight 9.0 times 10-6 Daltons. The RNA was shown to have a sedimentation coefficient of 50.
TL;DR: An agar-gel precipitation antigen prepared from the skin of chicken infected with JM strain of Marek's disease herpesvirus and cell extracts of cultures infected with either Type 2 plaque producing agent (PPA) of MDHV or turkey herpesv virus (HVT) (Type 2-Ag, HVT-Ag) had 1 precipitation line in common.
Abstract: An agar-gel precipitation antigen prepared from the skin (feather-Ag) of chicken infected with JM strain of Marek's disease herpesvirus (MDHV) and cell extracts of cultures infected with either Type 2 plaque producing agent (PPA) of MDHV or turkey herpesvirus (HVT) (Type 2-Ag, HVT-Ag) had 1 precipitation line in common. Hyperimmune sera to the common antigen (common-Ag) neutralized both cell-free virus of Type 2 PPA and HVT. However, these viruses were neutralized to a greater extent by homologous antiserum. Absorption of HVT antiserum or hyperimmune serum to Type 2 PPA with common-Ag reduced their neutralizing activity. This reduction was almost complete with homologous antigen but less complete with heterologous antigen. The location of antigen in Type 2 PPA and HVT infected cells was determined using hyperimmune serum to the common-Ag in fluorescent antibody tests. Antigen mainly occurred in the cytoplasm of cells corresponding to the rounded refractile cells in the plaques, whereas unfixed cells showed antigen on the cytoplasmic membrane. The common-Ag associated with MDHV or HVT infections might be a virus structural component which is associated with the envelope.
TL;DR: A microplate test was developed for the determination of neutralizing antibody titers against porcine parvovirus and was proved to be highly sensitive and reproducible.
Abstract: A microplate test was developed for the determination of neutralizing antibody titers against porcine parvovirus. End points were read directly by using haemagglutination techniques. The test was proved to be highly sensitive and reproducible.
TL;DR: The degree of purity of virus suspensions was found not to influence measurably the log n.v.p./HCU ratios with the only exception of the strain B/Hong Kong/8/73 differing uniformly from the other strains tested.
Abstract: The ratios of the number of virus particles (n.v.p.) to the hemagglutinating activity were determined for a series of influenza A and B strains using both the photometric HCU method and the HA pattern test. The logarithms of the ratios of n.v.p./HCU ranged from 7.06 to 7.54 and the logarithms of the ratios of n.v.p./HA from 6.87 to 7.56.