| interaction of listeria monocytogenes and influenza in an animal model. | this study was designed to investigate the effects of viruses in the pathogenesis of listeria monocytogenes. the organisms used in this study were: listeria monocytogenes type 1 isolated from a local fatal case; mouse adapted influenza a/pr8/34 (honi); streptococcus pneumoniae group b (u.m. med. ctr.) and poliovirus type 2 mef--g3m2. balb-c mice were inoculated intraperitoneally with one ld50 of listeria monocytogenes. ten days later, the survivors were challenged intransally with 10 ld50 of inf ... | 1976 | 10263 |
| reconcentration of poliovirus from sewage. | virus can be adsorbed from effluents of sewage treatment plants on large-surface membranes. subsequent elution of virus requires large volumes, which in turn requires reconcentration of virus for assay. however, reconcentration of such viral eluates on small adsorbent surfaces is difficult because certain soluble sewage components are adsorbed along with the virus on the initial virus adsorbent and are removed along with the virus by the eluent. upon acidification of the initial eluate to reconc ... | 1976 | 10842 |
| studies on the characteristics of poliovirus type 3. iii. strain characteristics after passage in man. | the markers d, ist, ea1(oh)3 and rct at sub- and supraoptimal temperatures as well as neurovirulence (pmic) for monkeys was determined for strains isolated from children vaccinated with leon 12a1b vaccine, their contacts and from paralytic cases. the strains were isolated at early and late phases of excretion. the changes concerned mainly rct determined at supraoptimal temperatures, d and pmic markers, especially in strains isolated at the late phase of excretion. the passage through the human a ... | 1976 | 11664 |
| inactivation by bromine of single poliovirus particles in water. | quantitative electron microscopy shows that freon-extracted poliovirus, velocity banded in a sucrose gradient, contains over 95% single particles. this well-dispersed virus reacts quite rapidly with bromine in turbulent flowing water, losing plaque titer at the rate of one log10 unit in 10s at ph 7, 2 c, and at a bromine concentration of 2.2 mum. at 10 and 20 c the rate of disinfection (log10 plaque-forming units per second) is faster, and at both temperatures it increases in approximately linea ... | 1976 | 11745 |
| comparison of talc-celite and polyelectrolyte 60 in virus recovery from sewage: development of technique and experiments with poliovirus (type 1, sabin)-contaminated multilitre samples. | for virus recovery from sewage, a mixture of talc and celite was tested as a possible inexpensive substitute for polyelectrolyte 60 (pe 60). after adjustment of ph to 6 and the addition of 45-60 plaque forming units (pfu)/ml of poliovirus type i (sabin) to the sewage sample under test, 100 ml of it was passed through either a pe 60 (400 mg) or a talc (300 mg)-celite (100 mg) layer; the layer-adsorbed virus was eluted with 10 ml of 10% fetal calf serum (fcs) in saline (ph 7.2). in these experimen ... | 1976 | 10064 |
| poliovirus survival and movement in a sandy forest soil. | movement of poliovirus i (chat) through nonsterile core samples of a sandy forest soil was monitored, using several regimens of loading with either dechlorinated final effluent from an operating activated sludge treatment plant or distilled water. stimulated cycles of rainfall and effluent applications, resulting in ionic gradients, were shown to affect virus movement. such studies indicate that poliovirus applied in effluents may move considerable distances through this soil after rainfall. sur ... | 1976 | 5057 |
| studies on the in vitro uncoating of poliovirus. i. characterization of the modifying factor and the modifying reaction. | | 1976 | 4921 |
| virus inactivation by grapes and wines. | infusions and extracts of different grapes inactivated poliovirus; agents responsible for this property resided in the skin of the grape. commercial grape juice at both natural and neutral ph inactivate various enteric viruses and herpes simplex virus; a 1,000-fold reduction in poliovirus infectivity occurred after incubation with grape juice, ph 7.0, for 24 h at 4 degrees c. a variety of wines were antiviral but to a lesser extent than grape juice; red wines were more antiviral than white. anti ... | 1976 | 12719 |
| study of the conditions for concentrating the poliomyelitis virus and e. coli bacteriophages on ion-exchange resins. | | 1977 | 15925 |
| selective inhibiton of uncoating of echovirus 12 by rhodanine. a study on early virus-cell interactions. | | 1977 | 16383 |
| aggregation of poliovirus and reovirus by dilution in water. | poliovirus and reovirus were found to aggregate into clumps of up to several hundred particles when diluted 10-fold into distilled water from a stock preparation of minimal aggregation in 0.05 m phosphate buffer, ph 7.2, plus 22 to 30% sucrose. reovirus was also found to aggregate when diluted into phosphate-buffered saline. the aggregation was concentration dependent and did not occur when either virus was diluted into water 100-fold or greater. the aggregation of poliovirus was reversible by f ... | 1977 | 13711 |
| effect of acid ph, salts, and temperature on the infectivity and physical integrity of enteroviruses. | at 2 degrees and 30 degrees c, enteroviruses are more stable on the acid than on the alkaline side of neutrality. in the range from ph 3 to 9, temperature is so influential that the fastest inactivation rate at 2 degrees c is slower than the slowest inactivation rate at 30 degrees c. specific ions or salts also affect the rate of inactivation of enteroviruses. nacl and other chloride salts enhance the inactivation of poliovirus at ph 3. nacl is considerably less effective against poliovirus in t ... | 1976 | 13766 |
| characteristics of poliovirus type 3 strains after passage through monkey central nervous system. | cercopithecus aethiops monkeys were inoculated intracerebrally with sabin's type 3 polivoirus strain, and with strains isolated from subjects vaccinated with leon 12a1b and from their contacts. sample of brain, spinal cord, kidneys, lymph nodes, blood and spinal fluid were taken. from these materials, (except of kidneys) 23 poliovirus strains of type 3 were isolated. genetic markers rct 40.3, rct 41, d and ist were determined for these strains. the changes observed in genetic markers of strains ... | 1977 | 15438 |
| development of a quantitative method for detecting enteroviruses in estuarine sediments. | several investigators have reported on the detection of enteric viruses in marine sediments, but none determined the efficiency of their methods and only limited volumes of sediment were sampled. the purpose of this investigation was to develop a quantitative method for detecting enteroviruses in marine sediments so that their relative proportion to viruses freely suspended in estuarine water could be more accurately determined. poliovirus was found to adsorb readily to natural marine sediments ... | 1977 | 20839 |
| identification of the virucidal agent in wastewater sludge. | anaerobically digested sludge contains an agent that causes irreversible inactivation of poliovirus. it has now been shown that the agent responsible for this activity is ammonia. the effect of ammonia on poliovirus appears to be typical for picornaviruses, but reovirus, an enteric virus of another group, is quite resistant to this compound. because ammonia is not virucidal in its charged state, it expresses significant activity only at ph values greater than 8. therefore, increasing the ph of s ... | 1977 | 17367 |
| concentration of enteroviruses from large volumes of turbid estuary water. | a method is described for the efficient concentration of viruses from large volumes of highly turbid estuary water. virus in acidified seawater in the presence of aluminum chloride is adsorbed to a 10-in. (about 25.4 cm) fibreglass depth cartridge and 2- and 0.65-micron epoxy-fibreglass filters in series. this filter series is capable of efficiently adsorbing enteroviruses from 50 u.s. gallons (about 190) of estuary water of varying salinity and turbidity. adsorbed viruses were eluted from the f ... | 1977 | 17465 |
| concentration of enteroviruses from estuarine water. | pleated cartridge filters readily adsorb viruses in estuarine water at low ph containing aluminum chloride. adsorbed viruses are efficiently recovered by treating filters with glycine buffer at high ph. by using these procedures, it was possible to recover approximately 70% of the poliovirus added to 400 liters of estuarine water in 3 liters of filter eluate. reconcentration of virus in the filter eluate in small volumes that are convenient for viral assays was more difficult. reconcentration me ... | 1977 | 18088 |
| discovery of an agent in wastewater sludge that reduces the heat required to inactivate reovirus. | an agent that causes heat inactivation of reovirus to occur at reduced temperatures has been found in both raw and anaerobically digested sludge. this agent is originally associated with sludge solids but can be washed from these solids by blending with water. the activity of the agent was considerably greater in alkaline than in acid solutions, probably because it is insoluble at low ph. the agent was shown to be nonvolatile and heat stable up to 300 degrees c but was inactivated within 30 min ... | 1977 | 23072 |
| application of a tricin-buffered modification of the cmrl-1969 medium in cell and virus cultivation (author's transl). | cmrl-1969 medium (healy et al., 1971) was modified by using 0.02 molar n-tris-(hydroxymethyl)-methyl-glycin (= tricin) instead of bicarbonate as the buffer substance. several permanent cell lines and primary cell cultures did not show growth differences in the two medium variants. like other non volatile buffers tricin abolishes the initial increase of the ph in freshly split or newly fed closed vessel cultures, but in 0.02 m concentration maintains the same buffering capacity of the medium as c ... | 1977 | 24962 |
| viral aggregation: effects of salts on the aggregation of poliovirus and reovirus at low ph. | as a first step toward the understanding of virus particle interactions in water, we have used the modified single particle analysis test to follow the aggregation of poliovirus and reovirus as induced by low ph in suspensions containing varying amounts of dissolved salts. salts composed of mono-, di-, and trivalent cations and mono- and divalent anions were tested for their ability to reduce or increase the aggregation of these viruses in relation to that obtained by low ph alone. mono- and div ... | 1978 | 28078 |
| concentration of poliovirus from tap water onto membrane filters with aluminum chloride at ambient ph levels. | a method is described for the concentration of an enterovirus from large volumes of tap water by addition of small amounts of aluminum chloride to enhance virus removal by membrane filters. tap water treated with 2 x 10(-5) m aluminum chloride showed a slight decrease in ph (less than 0.5), a slight increase in turbidity, and enhanced removal of poliovirus by membrane filters. virus was quantitatively recovered by treating the filters with a basic buffer, and this eluate was reconcentrated to a ... | 1978 | 25048 |
| the effect of inhibitors of cellular rna synthesis on stimulation of mouse encephalomyocarditis virus reproduction by poliovirus in hela and mio cells. | inoculation of hela and mio cells with a guanidine-dependent mutant of poliovirus (gd-polio) in the absence of guanidine resulted in stimulation of mouse encephalomyocarditis (emc) virus reproduction. no stimulation was found to occur in the presence of actinomycin d, on pre-treatment of the cells with cordycepin, or on their uv irradiation or enucleation. in contrast to hela cells, the enhancement of emc virus reproduction by gd-polio in mio cells required no current synthesis of cellular rnas: ... | 1978 | 27964 |
| viral aggregation: quantitation and kinetics of the aggregation of poliovirus and reovirus. | the aggregation of poliovirus and reovirus was followed in buffers at various ph values by means of a single particle analysis (spa) test. the spa test used here was modified from the original test reported earlier to prevent disaggregation of virus clumps from invalidating the results. the modified spa test demonstrated that the efficiency of aggregation, which is a measure of the percentage of collisions which are effective in producing an aggregate, may vary widely depending on the conditions ... | 1978 | 28077 |
| field survey of enteric viruses in solid waste landfill leachates. | because municipal solid waste may contain fecal material from a variety of sources, there is concern that the leachate discharged from some solid waste landfills may contain enteric pathogens, including enteric viruses. in this study, 22 leachate samples from 21 different landfills in the united states and canada were examined for enteric viruses. the sites represented a broad range of conditions for solid waste landfills and the leachate samples ranged from 10.3 to 18 liters in volume. enteric ... | 1978 | 28677 |
| efficiency of beef extract for the recovery of poliovirus from wastewater effluents. | the efficiency of poliovirus elution from fiber glass cartridge filters (k27), epoxy-fiber glass-asbestos filters (m780), and pleated cartridge filters was assessed by using 3% beef extract (ph 9.0) or 0.1 m glycine (ph 11.5). poliovirus type i, strain lsc, was seeded into 20- to 25-gallon (ca. 75.6- to 95.6-liter) samples of treated sewage effluent and concentrated by using a filter adsorption-elution technique. virus elution was accomplished by using either two 600-ml portions of 3% beef extra ... | 1978 | 30391 |
| improved methods for detecting enteric viruses in oysters. | new and improved methods for concentrating enteroviruses, reoviruses, and adenoviruses from oysters have been developed and evaluated. viruses are efficiently adsorbed to homogenized oyster meat by adjusting the homogenate to ph 5.0 and a conductivity of less than or equal to 2,000 mg of nacl per liter. after low-speed centrifugation, the virus-free supernatant is discarded and the viruses are eluted from the sedimented oyster solids with ph 7.5 glycine-nacl having a conductivity of 8,000 mg of ... | 1978 | 29555 |
| inactivation of enteroviruses by ascorbic acid and sodium bisulfite. | poliovirus type 1, coxsackievirus type a9, and echovirus type 7 were inactivated by sodium bisulfite and ascorbic acid. inactivation rates depended upon concentration, temperature, and ph. rna infectivity was lost during inactivation; the capsid was also altered by these inactivating agents, as determined by enzyme sensitivity assays and by tests of adsorption to cells. structural modifications of the virus particles were not identical, suggesting that the mechanism of inactivation by ascorbic a ... | 1978 | 29558 |
| development of quantitative methods for the detection of enteroviruses in sewage sludges during activation and following land disposal. | the development and evaluation of methods for the quantitative recovery of enteroviruses from sewage sludge are reported. activated sewage sludge solids were collected by centrifugation, and elution of the solid-associated virus was accomplished by mechanical agitation in glycine buffer at ph 11.0. eluted viruses were concentrated either onto an aluminum hydroxide floc or by association with a floc which formed de novo upon adjustment of the glycine eluate to ph 3.5. viruses which remained in th ... | 1978 | 29559 |
| antiviral effect of apple beverages. | a variety of apple beverages were tested for antiviral activity against poliovirus 1 or coxsackievirus b5. freshly prepared apple juice was particularly antiviral, but its activity declined more readily than that of commercial juice in response to heat and storage. the component responsible for activity was located both in the pulp and skin; after ultrafiltration, activity was present in fractions greater and less than molecular weight 10,000. virus infectivity was not restored from virus-apple ... | 1978 | 32832 |
| concentration of poliovirus from tap water using positively charged microporous filters. | microporous filters that are more electropositive than the negatively charged filters currently used for virus concentrations from water by filter adsorption-elution methods were evaluated for poliovirus recovery from tap water. zeta plus filters composed of diatomaceous earth-cellulose-"charge-modified" resin mixtures and having a net positive charge of up to ph 5 to 6 efficiently adsorbed poliovirus from tap water at ambient ph levels 7.0 to 7.5 without added multivalent cation salts. the adso ... | 1979 | 36844 |
| development of a quantitative method for the detection of enteroviruses in soil. | a method is described for efficiently concentrating enteroviruses from soil. viruses were eluted from soil by mechanical agitation in high ph glycine buffer containing ethylenediaminetetraacetic acid. the eluted viruses were concentrated on a floc that formed de novo upon adjustment of the soil eluate to 0.06 m aluminum chloride and ph 3.5. viruses not pelleted with the floc were concentrated by adsorption to and elution from membrane filters. this method yielded an average efficiency of 66% rec ... | 1979 | 36845 |
| measurement of the inactivation kinetics of poliovirus by ozone in a fast-flow mixer. | inactivation kinetics of poliovirus type 1 in ozone demand-free water was investigated by utilizing a fast-flow mixing apparatus. ozonated water and a solution of ozone demand-free water containing a known quantity of poliovirus type 1 were introduced simultaneously into a mixing chamber, both at a constant rate. this mixture was then passed through a narrow tube of known length and diameter into a neutralizing solution. by altering the rate of introduction and/or tube length, different contact ... | 1979 | 36847 |
| influence of ph, salinity, and organic matter on the adsorption of enteric viruses to estuarine sediment. | this study was designed to determine the degree of adsorption of enteric viruses to marine sediment and factors controlling this association. adsorption and elution characteristics of several enteroviruses and one rotavirus to estuarine sediments were studied under varying conditions of ph, salinity, and presence of soluble organics. greater than 99% of the added poliovirus type 1 (lsc), coxsackievirus type b3 (nancy), echovirus type 7 (wallace), and rotavirus (sa-11) adsorbed to sediment. echov ... | 1979 | 39508 |
| comparative adsorption of human enteroviruses, simian rotavirus, and selected bacteriophages to soils. | virus adsorption to soils is considered to be the most important factor in removing viruses after land treatment of wastewater. most of the studies on virus adsorption to soils have utilized poliovirus as the model system. in the present study, comparative adsorption of a number of different types and strains of human enteroviruses and bacteriophages to nine different soil types was studied. under the experimental conditions of this study, greater than 90% of all viruses adsorbed to a sandy loam ... | 1979 | 42350 |
| ph modification of the effects of detergents on the stability of enteric viruses. | the effect of detergents on the stability of enteric viruses was found to be highly dependent on ph. this was demonstrated primarily with two ionic detergents, sodium dodecyl sulfate (an anionic detergent) and dodecyltrimethylammonium chloride (a cationic detergent). both detergents were shown to be potent virucidal agents for reovirus, but the effects of sodium dodecyl sulfate were minimal near neutrality and much more pronounced at low than at high ph values. dodecyltrimethylammonium chloride ... | 1979 | 42351 |
| viral aggregation: buffer effects in the aggregation of poliovirus and reovirus at low and high ph. | the effects of the buffer employed in maintaining a given ph value were tested on the aggregation of two viruses, poliovirus and reovirus. poliovirus was found to aggregate at ph values of 6 and below, but not at ph 7 or above, except in borate buffer. reovirus aggregated at ph 4 and below, but was found to aggregate only in acetate or tris(hydroxymethyl)aminomethane-citrate buffers at ph 5. other buffers tested for aggregation of reovirus at ph 5 (succinate, citrate, and phosphate-citrate) indu ... | 1979 | 43706 |
| the latex agglutination test in virus diagnostic: identification of poliomyelitis and coxsackie viruses. | we examined the practical value of the latex agglutination test (la test) in diagnostic virology. viruses isolated from 125 specimens were identified in the la test. all results were in agreement with those observed by a neutralization test. the la test appears to be superior to conventional methods because of its easy handling and a rapid and reliable identification. | 1979 | 44781 |
| immunologic and virologic aspects of secretory immune system in human respiratory tract. | many external mucosal surfaces in man are replete with immunoglobulin containing plasma cells and thymic dependent (t) lymphocytes. immunization with viral vaccines administered via different routes have indicated that viral specific secretory immunoglobulins particularly of gamma a class are synthesized locally in the external mucosal surfaces. local availability of viral antigens especially after local mucosal immunization appears to be the most effective means of inducing viral specific secre ... | 1975 | 47823 |
| rubella-virus infection in juvenile rheumatoid arthritis. | antibody activity against mumps, measles, polio, and rubella viruses was determined in patients with juvenile rheumatoid arthritis (j.r.a.), rubella-vaccine associated arthritis, adult rheumatoid arthritis, other chronic systemic disorders (e.g., systemic lupus and dermatomyositis), and in a matched population of normal, non-rheumatoid (control) children. the antibody levels against mumps, measles, and poliovirus were similar in all patients. rubella-antibody levels in rheumatoid arthritis and o ... | 1975 | 48775 |
| enterovirus inactivation in soil. | the inactivation of radioactively labeled poliovirus type 1 and coxsackievirus b 1 in soils saturated with surface water, groundwater, and septic tank liquor was directly proportional to temperature. virus persistence was also related to soil type and the liquid amendment in which viruses were suspended. at 37 degrees c, no infectivity was recovered from saturated soil after 12 days; at 4 degrees c, viruses persisted for at least 180 days. no infectivity was recovered from dried soil regardless ... | 1979 | 44178 |
| low molecular weight substitutes for beef extract as eluents for poliovirus adsorbed to membrane filters. | basic solutions of beef extract and casein were able to elute poliovirus adsorbed to four membrane filters with different chemical compositions. hydrolyzed protein and individual amino acids were able to elute virus adsorbed to certain filters but were unable to elute virus adsorbed to other filters efficiently. a solution of 4 m urea buffered at ph 9 with 0.05 m lysine was able to elute greater than 60% of the virus adsorbed to each of the filters tested. certain solutions of amino acids were c ... | 1979 | 44223 |
| screen for type-c ribonucleic acid viruses in vaccines using the ribonucleic acid-dependent deoxyribonucleic acid polymerase assay. | the ribonucleic acid-dependent deoxyribonucleic acid polymerase assay was used to detect type-c viruses in live virus vaccines. conditions were first established to maximize the sensitivity of the assay. vaccines tested included live poliomyelitis, rubella, measles, mumps, and yellow fever. only yellow fever and measles vaccines known to have been produced in avian leukosis-contaminated cells showed evidence of type-c viruses using the assay. the result of the survey show that the assay has dire ... | 1975 | 51857 |
| viral aggregation: mixed suspensions of poliovirus and reovirus. | the aggregation of mixtures of two dissimilar viruses, poliovirus i (mahoney) and reovirus iii (dearing), was followed by electron microscopy under conditions known to induce either aggregation or dispersion of each virus separately. neither virus aggregated at ph 7 in an appropriate buffer, and no mixed aggregates were formed. under conditions of lowered ionic strength (by dilution into distilled water) poliovirus became aggregated, whereas reovirus did not, and again no mixed aggregates were f ... | 1979 | 44447 |
| poliovirus temperature-sensitivie mutants defective in cytopathic effects are also defective in synthesis of double-stranded rna. | the proportion of cells absorbing trypan blue (tb-+ character) can be used to measure the late c.p.e. of wild-type poliovirus (ts-+. tb-+), which was the same at restrictive (39-2 to 39-6 degrees c) or permissive (37 degrees c) temperatures. of twenty ts mutants, seven showed normal c.p.e. at 37 degrees c but were defective in c.p.e. (tb) at 39-5 degrees c; all seven tb mutants have previously been shown (cooper et al. 1971) to give evidence of a primary defect in replicase 1 activity (to make t ... | 1975 | 49394 |
| possible selection of virulent poliovirus strains in third-world countries. | in kenya for more than twenty years a remarkable periodicity has been observed in the circulation of type-1 poliovirus and in epidemics of poliomyelitis caused by this virus type. periodicity was less obvious for poliovirus types 2 and 3. cases of poliomyelitis increased, and this trend was only partly controlled by vaccination. it is postulated that virulent strains of poliovirus became dominant because of selection pressure. it is suggested that this selection pressure occurred earlier in econ ... | 1976 | 54685 |
| viruses, polymerases, and cancer. | | 1976 | 57644 |
| the inactivation of polio-, coxsackie- and semliki forest viruses by a tri-iodinated benzamido-derivative of glucose. | | 1976 | 64225 |
| jejunal viral antigen in multiple sclerosis and amyotrophic lateral sclerosis. | | 1977 | 65554 |
| synthesis of extensive, possibly complete, dna copies of poliovirus rna in high yields and at high specific activities. | the synthesis of large, possibly complete, complementary dna (cdna) copies of poliovirus rna by avian myeloblastosis virus dna polymerase is described. the cdna consists of two size classes, the larger of which is approximately 7500 nucleotides. in the presence of excess deoxynucleoside triphosphates, ribonucleoside triphosphates, or sodium pyrophosphate, only the larger material is obtained. yields of the large cdna are 50-75% of the input rna. | 1976 | 59925 |
| evidence for a cytoplasmic factor affecting the behaviour of poliovirus polypeptides during electrophoresis in sds [proceedings]. | | 1976 | 66021 |
| the effect of sodium metrizoate, d-glucosamine and n-acetylglucosamine on the infectivity of polio-, coxsackie, semliki forest- and measles virus in vitro [proceedings]. | | 1976 | 66022 |
| jejunal immunopathology in amyotrophic lateral sclerosis and multiple sclerosis. identification of viral antigens by immunofluorescence. | jejunal mucosa from 7 patients with amyotrophic lateral sclerosis (a.l.s.), 20 newly reported patients with multiple sclerosis (m.s.), and 35 control patients without either disease was studied by immunofluorescence. an immune reaction was present in all a.l.s. specimens and consisted of altered ratios of immunoglobulin-labelled cells in the lamina propria, complement-labelled cells in the same location, and, in some, immunoglobulin and complement deposits in the epithelial basement membrane. po ... | 1977 | 68222 |
| picornaviral structure and protein synthesis. | | 1976 | 65981 |
| studies on the characteristics of poliovirus type 3. ii. characteristics of "hot" clones. | markers d, ist, ea1(oh)3, rct (at sub- and supraoptimal temperatures) and neurovirulence were determined for clones isolated from two lots (s2 and s3) of vaccines containing poliovirus strain leon 12a1b. changes of markers rct, d and neurovirulence were observed in several clones isolated from s2 vaccine. no changes were observed in ist and ea1(oh)3 markers. | 1976 | 63237 |
| anticomplementary nature of smaller dna produced during synthesis of extensive dna copies of poliovirus rna. | the reverse transcriptase (rna-directed dna nucleotidyltransferase) from avian myeloblastosis virus is able to make an extensive, possibly complete, complementary dna copy of intact poliovirus rna. in the presence of high concentrations of deoxyribonucleoside triphosphates, ribonucleoside triphosphates, or sodium pyrophosphate, this dna is the only species produced. without these additives, however, a second size class of dna is also synthesized. this material has a sedimentation coefficient bet ... | 1976 | 62359 |
| human histocompatibility determinants and virus antigens: effect of measles virus infection on hla expression. | histocompatibility antigens on the surface of human lymphoblastoid cells were quantified by a microadsorption technique. during the course of measles virus infection, no quantitative or qualitations in surface hla antigens were observed. in contrast, infection with poliovirus type 1 or vesicular stomatitis virus, or treatment with puromycin (50 microgram/ml) resulted in a significant decrease in surface hla. these experiments suggest that an inhibition of host protein synthesis rather than the i ... | 1977 | 68989 |
| comparison of the antibodies elicited by the individual structural polypeptides of foot-and mouth disease and polio viruses. | antibody produced against preparations of vp1, one of the four structural polypeptides of foot-and-mouth disease virus, neutralized the virus and reacted with both full and empty particles in radioimmunoassays (ria). antiserum against vp2 reacted with artificial empty particles of the virus but not with full particles. in contrast, none of the individual polypeptides of poliovirus produced antisera which neutralized the virus nor reacted with it in ria. however, antisera produced with vp1 and vp ... | 1979 | 94352 |
| polio antibodies and hla antigens in amyotrophic lateral sclerosis. | amyotrophic lateral sclerosis (als) is a fatal, progressive disease of the central nervous system. its possible association with poliomyelitis was studied by measuring neutralizing antibodies against polio virus types 1, 2 and 3 in the sera and cerebrospinal fluids of 11 als-patients, but antibody titers did not markedly differ from those of the controls. the hla antigens of 12 als patients were also determined, in order to reveal any possible genetically-determined susceptibility to the disease ... | 1977 | 72426 |
| possible persistent virus in motor-neurone disease. | | 1977 | 73085 |
| production of cells and viruses in a new multiple-tube tissue culture propagator. | a novel method for large-scale culture of anchorage-dependent cells is described. culture vessels were constructed by using roller bottles and pyrex tubing. parallel glass tubes, equally spaced by silicone rings and inserted into the roller bottles, provided an increased culture area. the roller bottles were fitted with a second opening for medium recirculation. culture vessels of 1,000-, 4,000-, 8,000- and 16,000-cm2 growth area were constructed to propagate vero, bs-c-1, primary chicken embryo ... | 1979 | 115897 |
| [intratypical antigenic differentiation of poliovirus strains circulating in mali by means of cross-adsorbed sera]. | the intratypic antigenic differentiation of poliovirus strains isolated from sick or healthy children in mali in 1975-1976 was performed. the method is based on the use of cross-adsorbed sera in the neutralization tests in which the virus is titrated by the plaque procedure or by the cytopathic effect. all the examined strains of serologic types i, ii, and iii were distinguished by the antigenic structure from the vaccine strains and were classified as "wild". quantitative differences in the ant ... | 1978 | 86237 |
| tetracycline-mediated photodynamic inactivation of animal viruses. | demethylchlortetracycline (dmct), doxycycline and, to a lesser extent, chlortetracycline were capable of mediating the in vitro photoinactivation of venezuelan equine encephalitis (vee) virus. other tetracyclines tested were found to be inactive in this respect. however, no correlation between chemical structure and photosensitizing activity could be established. the photoinactivation of vee virus by dmct proceeds through a photodynamic mechanism as shown by the absolute requirement of o2 for th ... | 1979 | 120411 |
| virus development in enucleate cells: echovirus, poliovirus, pseudorabies virus, reovirus, respiratory syncytial virus and semliki forest virus. | a group of rna viruses, echovirus, poliovirus, reovirus, respiratory syncytial virus and semliki forest virus have been examined for ability to grow in enucleate african green monkey kidney (bsci) cells. semliki forest virus produced an almost normal yield of virus but poliovirus, echovirus, reovirus and respiratory syncytial virus, although showing clear evidence of virus replication when compared with a nuclear dna virus (pseudorabies virus) gave much lower yields than those from nucleate cell ... | 1975 | 163289 |
| alteration of capsid proteins of coxsackievirus a13 by low ionic concentrations. | several group a coxsackieviruses (a13, 15, 18, and 21), but not polioviruses or group b coxsackieviruses, are rapidly inactivated in low ionic strength solutions at neutral ph. the extent of inactivation is dependent upon temperature and molarity. virions inactivated in this manner contain a normal complement of infectious rna which remains in a state resistant to the action of ribonuclease. however, more than 95% of the virus particles are unable to attach to susceptible cells. sodium dodecyl s ... | 1975 | 163352 |
| sensitization of hela cells for viral rna infection by cytochalasin b. | | 1975 | 163527 |
| in vitro assembly of polioviruses. iv. evidence for the existence of two assembly steps in the formation of empty capsids from 14 s particles. | | 1975 | 163531 |
| [results of immunization of seronegative children with live poliomyelitis vaccine]. | the humoral immunity status to poliomyelitis viruses was studied in a group of children under 3 years previously immunized at least 3 times with slv incorporated into dragee-candy. a regular increase with age of the number of subjects possessing virus-neutralizaing antibody to poliomyelitis viruses was demonstrated, the incidence of antibody to the three virus types being distributed by age groups as follows: under 1 year -- 24%, 1 year -- 53%, 2 years -- 71.2%, 3 years -- 84.8%. the immune resp ... | 1978 | 153652 |
| [status of herd immunity to poliomyelitis in children in the moscow region]. | the paper presents the results of 3-year observations of the status of herd immunity to poliomyelitis in 7 towns of the moscow region. in individual years antibody for poliomyelitis virus of 3 types was found in 63-74% of the examined children and from 2.7 to 7.5% of children were triple-negative. insufficient levels of herd immunity to poliovirus types i and iii were found. some factors are analysed which could have some influence on the decline of herd immunity. | 1975 | 123674 |
| [investigations on immunity against poliomyelitis (author's transl)]. | six virus laboratories from various parts of the german federal republic and west berlin undertook investigations into polio-myelitis immunity in 1972. a total of 267 persons aged up to 20 years were investigated for neutralizing antibodies against the three types of polio virus. the study showed that from the fourth year of life approximately 70% of the persons investigated had antibodies against all three types of polio virus. in some younger children the equivalent values were considerably lo ... | 1975 | 163177 |
| uptake and elimination of poliovirus by west coast oysters. | accumulation of poliovirus lsc-2ab by west coast oysters was determined by using a stationary seawater system, and depuration was determined by using both stationary and free-flow systems. results indicate that these shellfish have the same pattern of accumulation and localization of viruses as do east coast species. however, uptake appeared to occur more rapidly than described for east coast shellfish. there appeared to be a gradual diffusion of virus from the digestive area into the body. depu ... | 1975 | 163615 |
| ecology of respiratory virus transmission: a comparison of three communities in west bengal. | respiratory virus transmission in children was studied comparatively in three ecologically different low-income communities in west bengal: an isolated village, a suburban village, and a crowded urban community. continued use of contaminated pond water for bathing, irrigation of nasal passages, post-defecation washing of the anus, and washing of food vessels was common to all, as was intense crowding of indoor sleeping quarters during cold and wet seasons. intensity of infection was highest (26% ... | 1975 | 164134 |
| [persistence of latex agglutination inhibition antibodies in rabbits following application of poliomyelitis-, coxsackie-, echo- and encephalomyocarditis viruses. brief report]. | | 1975 | 164163 |
| sero-immunity to poliovirus in children and young women: england 1972-4. | a total of 292 children's sera and 706 antenatal sera from different parts of england were tested for the presence of poliovirus neutralizing antibodies. little vairation was found between different areas and types of community, but a lower porportion of the 5-14 year old children had antibody than younger children and young adult women. the proportion of the young population with antibody, and the current acceptance rates for oral poliovirus vaccine are barely satisfactory. | 1975 | 164503 |
| isolation and characterization of 'dense particles' from poliovirus-infected hela cells. | dense poliovirus particles (buoyant density 1.44 g/ml in cscl) isolated from infected hela cells contain the normal four structural polypeptides vp1 to vp4, and 35s poliovirus rna. in addition, small amounts of vpo and single-stranded rna sedimenting slower than the poliovirus genome are present. dense particles have a low specific infectivity, are neutralized by type-specific poliovirus antisera, and are detected during growth as early as normal virus but disappear when virus production stops. ... | 1975 | 164520 |
| assembly of viruses. | | 1975 | 164048 |
| the importance of picornavirus infections in respiratory disease of man and other mammals. | picornaviruses may be divided, by physicochemical properties, into enteroviruses, cardioviruses, caliciviruses, rhinoviruses and foot-and-mouth diseases viruses. although the respiratory tract may be the primary site of entry and multiplication for enteroviruses, cardioviruses and fmd viruses, few agents in these groups cause respiratory disease. a notable exception is coxsackievirus a21 which is an important cause of upper respiratory tract diseases in military recruits. the picornaviruses whic ... | 1975 | 165133 |
| effect of mycoplasma pneumoniae on poliovirus replication. | results are presented which indicate that different species of mycoplasma may have varying effects on the replication of different viral types. | 1975 | 163801 |
| structural and functional alterations in cultured cells infected with cytocidal viruses. | | 1975 | 164054 |
| seroimmunity to poliomyelitis in an american community. | in an effort to determine the immune status of individuals in a natural community, neutralizing antibody titers for the three types of poliovirus were examined in 301 randomly sampled sera collected in 1966 and 308 specimens from 1971. the specimens were part of a larger collection obtained from residents of tecumseh, michigan. approximately 22 sera from each five-year age group between 5-70 years were tested. a somewhat smaller number from younger and older individuals were also studied. geomet ... | 1975 | 164770 |
| poliovirus-induced infectious double-stranded rna: effect of rna-degrading enzymes. | the infectivity of replicative form rna (rf-rna) isolated from poliovirus-infected hela cells is completely resistant to the action of t-1 rnase but decreases after exposure to rnase a in the presence of 0.3 m nacl. under these conditions neither enzyme produces single-stranded nicks in rf-rna. three endonuclease-free exonuleases (rnase ii, polynucleotide phosphorylase and spleen phosphodiesterase) rapidly destroy the infectivity of single-stranded rna, but do not alter the infectivity of rf-rna ... | 1975 | 166628 |
| irreversible inactivation by 2-amino-4,6-dichloropyrimidine of certain structural proteins of poliovirus. | | 1975 | 166865 |
| early alteration of poliovirus in infected cells and its specific inhibition. | hela cells infected with radioactive poliovirus type 2 were disrupted with ultrasonic treatment, followed by addition of a non-ionic detergent. two types of virus particles were found to sediment at 80 to 90% the rate of native virus. the first of these appeared to be a complex of native virus particles and membrane components, since treatment with 0-2% sds released infectious native particles. the second was non-infectious and its sedimentation rate was not greatly altered by sds. one hour afte ... | 1975 | 167116 |
| polyadenylic acid on poliovirus rna. ii. poly(a) on intracellular rnas. | the content, size, and mechanism of synthesis of 3'-terminal poly(a) on the various intracellular species of poliovirus rna have been examined. all viral rna species bound to poly(u) filters and contained rnase-resistant stretches of poly(a) which could be analyzed by electrophoresis in polyacrylamide gels. at 3 h after infection, the poly(a) on virion rna, relicative intermediate rna, polyribosomal rna, and total cytoplasmic 35s rna was heterogeneous in size with an average length of 75 nucleot ... | 1975 | 167193 |
| polyadenylic acid on poliovirus rna. iii. in vitro addition of polyadenylic acid to poliovirus rnas. | a crude rna polymerase preparation was made from hela cells infected for 3 h with poliovirus. all virus-specific rna species labeled in vitro (35s rna, replicative intermediate rna [ri], and double-stranded rna [dsrna]) would bind to poly(u) filters and contained rnase-resistant stretches of poly(a) which could be analyzed by electrophoresis in polyacrylamide gels. after incubation for 45 min with [3-h]atp in the presence of the other three nucleoside triphosphates, the labeled poly(a) on the ri ... | 1975 | 167194 |
| virus isolation and titration at 33 degrees and 37 degrees c. | various prototype viruses and original specimens were comparatively titrated in cell cultures at 33 degrees and 37 degrees c. higher titers at 37 degrees were consistently obtained with adenoviruses; for other viruses (enteroviruses, herpesvirus hominis, vaccinia virus, parainfluenza viruses) the titers were mostly identical at either temperature. original specimens and prototye strains showed the same behavior. the habit to cultivate viruses from throat swabs at 33 degrees c is unsatisfactory f ... | 1975 | 167268 |
| selective blockage of initiation of host protein synthesis in rna-virus-infected cells. | poliovirus mrna and mrna transcribed from vesicular stomatitis virus and reovirus genomes efficiently direct protein synthesis in vivo under experimental conditions where the initiation of host protein synthesis is selectively blocked. the selective blockage of host peptide chain initiation after exposure to hypertonic medium indicates that the translation of viral mrna is more efficiently initiated than is the translation of host mrna. it further suggests that virus directed suppression of host ... | 1975 | 165500 |
| the inhibitory effects of mgcl2 on the inactivation kinetics of poliovirus by urea. | by analyzing the inhibitory effects of mg-2+ on the three-stage urea inactivation curve of poliovirus, it was concluded that urea inactivates poliovirus via a two-step reaction as follows: urea initially converts the native virus into an intermediate state which is still infectious but is now highly sensitive to inactivation. this reaction is unaffected by mg-2+ and is reversible. in the subsequent reaction, the sensitized virus is either irreversibly inactivated by urea or reversibly stablized ... | 1975 | 165542 |
| evidence for conformational states of poliovirions: effects of cations on reactivity of poliovirions to guanidine. | the kinetics of inactivation of poliovirions were determined in the presence of various concentrations of monovalent and divalent ions, methionine, guanidine and combinations of these at various temperatures. four states of the virion, under control of the ionic environment, could be recognized which were reversibly interchangeable and yet retained infectious potential. these states were detected by differential sensitivity of the virion to inactivation of infectivity by heat, urea and guanidine ... | 1975 | 165543 |
| comparative study of four microporous filters for concentrating viruses from drinking water. | four microporous virus-absorbent filter media for recovering low levels of virus from 380 liters of drinking water were compared. in addition two of the filter media were compared with 1,900 liters of drinking water. the filter media evaluated were mf nitrocellulose membranes (293 mm), aa cox m-780 epoxy-fiberglass-asbestos disks (267 mm), k-27 yarn-wound fiberglass cartridges + aa cox m-780 disks (127 mm), and balston epoxy-fiberglass tubes (24.5 by 63.5 mm). the filters were used to concentrat ... | 1975 | 167662 |
| the enhancing effect of copper, nickel, and cobalt ions on plaque formation by semliki forest virus (sfv) in chicken embryo fibroblasts. | in cultured chicken embryo fibroblasts treated with copper-(copper cation 10-minus 3.5-10-minus 5 m), nickel and cobalt salts an enhancement of the plating efficiency of semliki forest virus could be observed. this augmented plaque formation was most probably due to a higher adsorption rate of virions to the cell surface under the influence of the transition metal ions. the plating efficiency of west nile virus in chicken-embryo fibroblasts and, to a lesser degree, of poliovius type 1 and 2 in k ... | 1975 | 167680 |
| [a quantitative demonstration of igm with sensitized latex particles]. | | 1975 | 167688 |
| virus survival on inanimate surfaces. | the persistence of several types of viruses on hard, inanimate surfaces under different relative humidities, temperatures, and types of surfaces was investigated. no differences in survival on glass, vinyl asbestos tile, ceramic tile, and stainless steel were found. under conditions of low humidity and room temperature, adenovirus, poliovirus, and herpes simplex virus survived for at least 8 weeks. vaccinia and coxsackie viruses survived for at least 2 weeks but differences due to surfaces found ... | 1975 | 167927 |
| analysis of specificity of poliovirus inhibitors with inhibitor-resistant mutants of a strain of type 1 poliovirus. | attempts were made to analyze the specificity of inhibitory activities of normal bovine and equine sera to the mahoney strain of type 1 poliovirus. a total of five inhibitory factors were postulated to explain the complicated results. two of the three bovine inhibitors were identical in specificity to certain equine inhibitors despite differences in their mode of virus inactivation and their molecular size. in addition to this, inhibitors that could inactivate certain resistant mutants, but not ... | 1975 | 168261 |
| reaction of poliovirus rnas with antibodies to double-stranded rna demonstrated by an immunochemical binding assay. | an immunochemical binding assay was used to investigate the reactivity of radioactively labeled viral rnas from poliovirus-infected cells with antibodies to the synthetic double-stranded rna, poly(i)-poly(c). a rnase-free antibody-containing serum fraction was employed. poliovirus replicative form reacted with the antibodies to poly(i)-poly(c) as well as or better than poly(i)-poly(c). poliovirus replicative intermediate reacted with the antibodies to a greater extent than poliovirus single-stra ... | 1975 | 168403 |
| [poliomyelitis in the province of tucuman: isolation, typification and serological study of the virus isolated during the 1971 epidemic]. | | 1975 | 167412 |
| the molecular biology of poliovirus. | | 1975 | 167433 |
| surveillance of enterovirus infections in bangkok. i. isolation of enterovirus from faecal specimens of healthy children. | during the period august 1970 through july 1973, about 50 faecal specimens collected each month from healthy pre-school children of lower economic status in bangkok were studied for virus isolation using primary monkey kidney cells and new born mice. from a total of 1,823 samples, 557 (30.5%) were positive: 86 (4.8%) polioviruses, 77 (4.2%) coxsackieviruses b, 223 (12.2%) echoviruses, and 127 strains (7.0%) of unidentified viruses. altogether, 45 serotypes of enteric viruses were identified. mor ... | 1975 | 167453 |
| demonstration of virus in groundwater after effluent discharge onto soil. | the survival of virus present in secondary effluents discharged into a cypress dome was studied. isolations were made from concentrates of water drawn from 10-foot (304.80 cm) deep wells. data presented show vertical and lateral virus movement as well as survival within the dome for 28 days during a period of heavy rains when no effluent was being applied. due to the inefficiency of virus concentration procedures, it is proposed that much of the virus present was probably not demonstrated. a rap ... | 1975 | 168809 |
| non-random frequencies of short oligonucleotide sequences within poliomyelitis and encephalomyocarditis virus rnas. | in poliomyelitis and encephalomyocarditis virus rnas the relative frequencies of several short oligonucleotide sequences differ substantially from those expected on a random basis. the frequencies of cpgp-containing sequences are low, and the frequency of gpupapgp is considerably lower than that of gpapupgp. the relationship of these findings to those obtained from host cell rnas is descussed. | 1975 | 168559 |
| evidence for control of translation of the viral genome during replication of mengo virus and poliovirus. | | 1975 | 169625 |