| new ganglioside analogs that inhibit influenza virus sialidase. | synthetic thioglycoside-analogs of gangliosides such as neu5ac alpha(2-s-6)glc beta(1-1)ceramide (1) and the gm3 analog neu5ac alpha(2-s-6)gal beta(1-4)glc beta(1-1)ceramide (2), competitively inhibited gm3 hydrolysis by the sialidase of different subtypes of human and animal influenza viruses with an apparent ki value of 2.8 x 10(-6) and 1.5 x 10(-5) m, respectively. the inhibitory activity of the ganglioside gm4 analog [neu5ac alpha(2-s-6)gal beta(1-1)ceramide (3)], in which the glucose of 1 w ... | 1990 | 2136350 |
| nucleotide sequence and some biological properties of the ns gene of a newly isolated influenza b virus mutant which has a long carboxyl terminal deletion in the ns1 protein. | by a heterotypic cross between influenza viruses a/wsn (h1n1) and b/yamagata/1/73, we obtained a mutant of b/yamagata (awby-234), which expressed a greatly truncated ns1 protein with molecular weight of 13,500. direct sequencing of the ns gene of the mutant revealed a deletion of a single uridine base at the position 310, 311, or 312 of the plus sense rna, giving rise to a new stop codon at the position 314-316. the resulting ns1 protein was predicted to be composed of only 90 amino acids, compa ... | 1990 | 2136779 |
| [prevention of influenza a. effectiveness and tolerance of rimantadine hydrochloride]. | the prophylactic effectiveness of rimantadine hydrochloride (rh) during an outbreak of influenza a was evaluated in a double-blind study versus placebo (p). after identification of 111 homes with one affected member, 301 household contacts were enrolled and given either rh (151 contacts from 56 households) or a placebo (150 contacts from 55 households). each treatment was given for ten days. overall, at least one contact developed influenza in 8 of the 56 rh group households and 19 of the 55 pla ... | 1990 | 2137233 |
| production of interleukin 1 and tumour necrosis factor activities in bronchoalveolar washings following infection of mice by influenza virus. | mice were infected with influenza a virus by aerosol. bronchoalveolar washings obtained from infected mice contained interleukin 1 (il-1) and tumour necrosis factor (tnf) activities. il-1 was present at day 4 post-infection but not at day 7. tnf activity was present at day 4 and day 7 post-infection. the presence of both these monokines was coincident with increased cell populations in the lungs. in vitro studies demonstrated that macrophages from non-infected mice produce il-1 and tnf activitie ... | 1990 | 2137872 |
| a 36 nucleotide deletion mutation in the coding region of the ns1 gene of an influenza a virus rna segment 8 specifies a temperature-dependent host range phenotype. | previously a spontaneous 36 nucleotide deletion in the coding region of ns1 was detected in the ns gene of a reassortant virus (cr43-3) recovered from a dual infection by the influenza a/ann arbor/6/60 cold-adapted (ca) mutant and wild-type (wt) influenza a/alaska/6/77 (h3n2). the hemagglutinin, neuraminidase and ns genes were derived from the wild type virus parent while the other 5 genes were derived from the ca parent. the cr43-3 reassortant virus exhibited: (i) a host range (hr) phenotype, i ... | 1990 | 2138396 |
| replication of h1n1 influenza viruses in cultured mouse embryo brain cells: virus strain and cell differentiation affect synthesis of proteins encoded in rna segments 7 and 8 and efficiency of mrna splicing. | the aims of these studies are (1) to determine whether, and by what mechanism(s), underexpression of m1 and/or ns1 protein restricts replication and cytopathogenicity in mouse brain cells of human influenza viruses which are closely related to the neurovirulent wsn variant but not selected for the neurovirulent phenotype; (2) to learn, ultimately, whether similarly restricted replication in natural infections might be enough to cause direct or indirect, immunologically mediated, neuropathology. ... | 1990 | 2140629 |
| analysis of influenza a virus temperature-sensitive mutants with mutations in rna segment 8. | temperature-sensitive (ts) mutants of influenza virus strain a/udorn/72 (h3n2 subtype) with lesions in rna segment 8 exhibited intrasegmental complementation, and were divided in two complementation groups (h1 and h2) on mdck cells. the nucleotide sequence of segment 8 was determined for three of these mutants. the h1 strains, icr1629 and spc45, have a single amino acid substitution in the coding region of the non-structural protein ns1, whereas the h2 strain, icr516, has a substitution in the n ... | 1990 | 2141068 |
| t-cell functions in ovarian cancer patients treated with viral oncolysates: i. increased helper activity to immunoglobulins production. | we investigated the humoral and cellular responses of ovarian cancer patients treated with viral oncolysates (vo) tumor vaccines. all patients treated with vo developed tumor cell surface-reacting antibodies and anti-hemagglutinin antibodies. furthermore, pbmc from these patients developed cellular proliferative responses to the cellular oncolysates (co). the in vitro proliferating population consisted mainly of cd4+ cells, as demonstrated by depletion experiments using the corresponding monoclo ... | 1990 | 2142392 |
| renal pathology in specific-pathogen-free chickens inoculated with a waterfowl-origin type a influenza virus. | five-week-old specific-pathogen-free chickens inoculated intravenously with a waterfowl-origin type a influenza virus (a/mallard/ohio/184/86) had swollen and mottled kidneys on days 3, 5, and 7 postinoculation (pi) and multiple raised nodules on days 5, 10, and 20 pi. histologically, the kidneys had multifocal heterophilic tubulointerstitial nephritis with epithelial necrosis on day 3 pi, lymphoplasmacytic tubulointerstitial nephritis on day 5 pi, and fibrosing interstitial nephritis with cortic ... | 1990 | 2142419 |
| persistence of avian influenza viruses in water. | persistence of five avian influenza viruses (aivs) derived from four waterfowl species in louisiana and representing five hemagglutinin and neuraminidase subtypes was determined in distilled water at 17 c and 28 c. infectivity was determined over 60 days by microtiter endpoint titration. one aiv was tested over 91 days at 4 c. linear regression models for these viruses predicted that an initial concentration of 1 x 10(6) tcid50/ml water could remain infective for up to 207 days at 17 c and up to ... | 1990 | 2142420 |
| effects of ph, temperature, and salinity on persistence of avian influenza viruses in water. | the combined effects of water temperature, salinity, and ph on persistence of avian influenza virus (aiv) were evaluated in a model distilled-water system using three isolates from ducks sampled in cameron parish, louisiana. variables were tested within the ranges normally associated with surface water. differences were detected between temperature (17 c and 28 c), ph (6.2, 7.2, 8.2), and salinity (0 ppt and 20 ppt), with a strong interactive effect observed between ph and salinity. estimated pe ... | 1990 | 2142421 |
| specific inhibition of the synthesis of influenza virus late proteins and stimulation of early, m2, and ns2 protein synthesis by 3-deazaadenosine. | 3-deazaaristeromycin and 3-deazaadenosine (3da-ado) both interfere with the methylation of rna, but only 3da-ado is metabolized to the corresponding homocysteine derivative. in contrast to 3-deazaaristeromycin, 3da-ado inhibits the synthesis of late influenza a virus proteins in chicken embryo cells (cec), while it causes an overproduction of early proteins and of the nonstructural proteins ns2 and m2. only the former effect of 3da-ado can be reversed by concomitant addition of adenosine, but no ... | 1990 | 2142557 |
| mutation in ns2, a nonstructural protein of influenza a virus, extragenically causes aberrant replication and expression of the pa gene and leads to generation of defective interfering particles. | several consecutive undiluted passages of infectious virus are usually required to obtain defective interfering particles of influenza virus. in contrast, a reassortant (wa-182) of influenza a/wsn, which we isolated, whose ns gene was replaced with the ns gene of a/aichi, was readily converted to defective interfering form after only a single high-multiplicity infection. the defective interfering particles of wa-182 were devoid of the pa gene (rna segment 3) but possessed several species of subg ... | 1990 | 2143025 |
| pulmonary antibacterial defenses during mild and severe influenza virus infection. | severe influenza virus infections with pneumonic involvement are known to predispose the lungs to bacterial superinfections due to dysfunctions in the alveolar macrophage (am) phagocytic system. to determine whether milder forms of influenza without pneumonic involvement have a similar outcome, pulmonary antibacterial defenses and am phagocytosis were compared in murine models of mild and severe influenza virus a/hk/68 infections. bactericidal activity was quantitated by the intrapulmonary killi ... | 1990 | 2143751 |
| evolution of the ns genes of the influenza a viruses. ii. characteristics of the amino acid changes in the ns1 proteins of the influenza a viruses. | we compared the amino acid sequences of the ns1 proteins of human, equine, and avian influenza viruses. the ratios of the amino acid substitutions per nucleotide substitutions in the ns1 proteins were about 27-45%, suggesting the existence of constraints on the amino acid changes of the ns1 protein in evolution. as a measure of constraints exerted on the regions of a protein, a changeability index is proposed. there was a highly conserved region between amino acid residues 30 and 50. the c-termi ... | 1990 | 2144065 |
| evolution of the ns genes of the influenza a viruses. i. the genetic relatedness of the ns genes of animal influenza viruses. | we compared the nucleotide sequences of the ns genes of 13 animal influenza viruses belonging to human, swine, avian, and equine viruses for the study of the genetic relatedness of the ns genes in animal influenza viruses. the ns genes of three virus strains a/chicken/brescia/02, a/equine/prague/56, and a/equine/miami/63 were newly sequenced. the base sequence homologies between the ns genes of avian, human, swine, and the a/equine/miami/63 viruses were 87.8% or higher. on the other hand, the ba ... | 1990 | 2144066 |
| regulation of human cytotoxic t lymphocyte development by il-7. | the effects of il-7 on the generation of human ctl in alloantigen-, virus-, and lectin-stimulated systems were examined. addition of il-7 at the onset of cultures resulted in marked (up to 80-fold) augmentation of cytotoxicity accompanied by smaller (1.5- to 4-fold) increases in total lymphocyte number. studies of ctl development in purified lectin-stimulated cd8+ t cell populations demonstrated that il-7 could act directly on the cd8+ lymphocyte subset to augment cytotoxicity. in mlc, the il-7- ... | 1990 | 2145359 |
| late dominance of the inflammatory process in murine influenza by gamma/delta + t cells. | the inflammatory response in the lungs of mice infected with an influenza a virus consists largely of macrophages and cd3+ t cells. most t lymphocytes recovered before day 7 after infection express mrna for the t cell receptor alpha/beta (tcr-alpha/beta), while tcr-gamma/delta mrna+ cells are found at much higher frequency over the next 7 d. the predominant surface phenotype for the tcr-gamma/delta mrna+ population is cd3+4-8-tcr-alpha/beta-. some lymphocytes expressing all the known v gamma gen ... | 1990 | 2145388 |
| mechanisms of neutralization of influenza virus in tracheal epithelial and bhk cells vary according to igg concentration. | the interaction of igg-neutralized type a influenza virus with differentiated epithelial cells of mouse trachea, bhk cells, and chicken erythrocytes was studied using three mouse monoclonal antibodies (igg2a) each directed against a different antigenic site on the hemagglutinin. at high hiu:hau ratios virus was neutralized greater than 99%, monodisperse, and attached to tracheal epithelial and bhk cells in normal amounts. the majority (70-80%) of neutralized virus failed to attach to erythrocyte ... | 1990 | 2145688 |
| e3/19k from adenovirus 2 is an immunosubversive protein that binds to a structural motif regulating the intracellular transport of major histocompatibility complex class i proteins. | we have previously expressed in transgenic mice a chimeric h-2kd/kk protein called c31, which contains the extracellular alpha 1 domain of kd, whereas the rest of the molecule is of kk origin. this molecule functions as a restriction element for alloreactive and influenza a-specific cytotoxic t lymphocytes (ctl) but is only weakly expressed at the cell surface of splenocytes. here, we show that the low cell surface expression is the result of slow intracellular transport and processing of the c3 ... | 1990 | 2147948 |
| [experimental microbiological research on instrument and denture disinfection with a disinfectant spray for dental practice and the use of patients. 2. virological studies; the evaluation summary]. | carrier experiments using echo- and influenza-viruses on denture basis resins and fragments of orthodontic appliances resulted in good and even very good virucidal effects of disinfectant sprays desident and fesia-sept. the application of the disinfectant as spray seem to be advantageous, but is not recommendable. the diverse causes of this conclusion are discussed and an alternative way is proposed. | 1990 | 2149903 |
| [human leukocytic interferon as an agent for emergency prevention of influenza and other acute respiratory diseases in children's preschool institutions]. | | 1990 | 2150098 |
| [the clinico-epidemiological characteristics of the course of a mixed epidemic of influenza and respiratory syncytial infection in novoshakhtinsk in the summer of 1986]. | in the summer of 1986 the epidemic, whose etiological agents were influenza viruses a (h1n1) and respiratory syncytial virus, was registered among the population of novoshakhtinsk. in a number of mines 15.3-16.7% of the employees were affected. influenza viruses a (h1n1) proved to be closely related in their antigenic and biological properties to viruses isolated in the ussr in march-june 1986, as well as to viruses a (h1n1), the etiological agents of the epidemic which developed in the ussr in ... | 1990 | 2151553 |
| characterization of influenza a virus activation of the human neutrophil. | neutrophil dysfunction consequent to influenza a virus infection has been described in vivo and in vitro and may contribute to the serious bacterial sequelae which occur in influenza-infected hosts. on the premise that such dysfunction may represent a form of "deactivation," we sought to characterize neutrophil activation by the virus in comparison with other agonists. the virus induces a respiratory burst in which h2o2 (but not o2-) are formed. preceding the respiratory burst, a rise in intrace ... | 1990 | 2153030 |
| fluoro carbocyclic nucleosides: synthesis and antiviral activity of 2'- and 6'-fluoro carbocyclic pyrimidine nucleosides including carbocyclic 1-(2-deoxy-2-fluoro-beta-d-arabinofuranosyl)-5-methyluracil and carbocyclic 1-(2-deoxy-2-fluoro-beta-d-arabinofuranosyl)-5-iodouracil. | the racemic carbocyclic 2'-fluoroarabinosyl pyrimidine nucleosides 8, 9 (c-fiau), 12, and 13 (c-fmau) and the 2'-fluororibosyl pyrimidine nucleosides 17, 20, and 21 were prepared from their respective protected 2'-fluoro amino diols 5 and 14. the carbocyclic 2'-2'-difluorothymidine analogue 27 was obtained from the protected difluoro amino diol 24 which was prepared from the ketone 23 and (diethylamino)sulfur trifluoride (dast). the chiral carbocyclic 2'-deoxy-6'-fluorouridines 33, 34, 38, and 3 ... | 1990 | 2153201 |
| emerging viruses, emerging threat. | | 1990 | 2153314 |
| fatal swine influenza pneumonia during late pregnancy. | serious morbidity or death from swine influenza infection is unusual in the immunocompetent host. we present a fatal case of pneumonia caused by this virus in a previously healthy 32-year-old woman during her third trimester of pregnancy, and review all published case reports of swine influenza in united states civilians. pregnancy may be a predisposing factor to fulminant infection with swine influenza virus. | 1990 | 2153372 |
| viral lower respiratory tract infections in filipino children. | viral causes of acute lower respiratory tract infection were studied prospectively between 15 june and 31 october 1984 in 312 filipino children less than 5 years old living in periurban slums and middle-class housing. the cause was based on viral antigen detection, virus isolation, and antibody assays. there were 131 children (41.2%) who were admitted to the hospital, and 150 (47%) had an infiltrate on chest radiograph. a total of 198 viral infections were confirmed in 162 patients (51.9%), 42.3 ... | 1990 | 2153734 |
| cloning and sequence analyses of cdnas for interferon- and virus-induced human mx proteins reveal that they contain putative guanine nucleotide-binding sites: functional study of the corresponding gene promoter. | the human protein p78 is induced and accumulated in cells treated with type i interferon or with some viruses. it is the human homolog of the mouse mx protein involved in resistance to influenza virus. a full-length cdna clone encoding the human p78 protein was cloned and sequenced. it contained an open reading frame of 662 amino acids, corresponding to a polypeptide with a predicted molecular weight of 75,500, in good agreement with the mr of 78,000 determined on sodium dodecyl sulfate gels for ... | 1990 | 2154602 |
| experimental influenza a virus myocarditis in mice. light and electron microscopic, virologic, and hemodynamic study. | to elucidate the heart involvement associated with influenza virus infection, the authors studied the hearts of influenza a/pr/8/34 virus-inoculated icr mice by light and electron microscopy, cardiac catheterization, virus assay, and indirect immunofluorescence. light microscopy showed small necrotic foci with inflammatory cell infiltration spreading in the myocardium on days 3 to 7 and evidence of healing by day 9 after inoculation. electron microscopy demonstrated that necrotic cell debris was ... | 1990 | 2154929 |
| [the effect of parvovirus vaccination in sows through their 4th parity and the role of influenza h1n1 virus]. | the effects of vaccination of a porcine parvovirus (ppv) in gilts and the first four litters were studied in a pig-breeding herd. in addition to determination of the technical results, ppv and influenza (h1n1) titres were measured. from the serological findings it was apparent that ppv and influenza (h1n1) virus circulated during the trial. the number of total-born and live-born piglets was significantly higher in the first litter when ppv-vaccinated and non-vaccinated gilts were compared. on th ... | 1990 | 2156355 |
| surveillance of viral respiratory tract infections over a one year period in mainly hospitalized austrian infants and children by a rapid enzyme-linked immunosorbent assay diagnosis. | in order to obtain more information on viral respiratory tract infections in austrian infants and children, nasopharyngeal secretions from 1432 infants and children, collected from october 1984 to october 1985, were screened for the presence of respiratory syncytial virus (rsv), adenoviruses, parainfluenza virus type 1, 2, and 3, and influenza viruses type a and b, by enzyme-linked immunosorbent assay (elisa). the results obtained were analyzed with respect to incidence, seasonal distribution an ... | 1990 | 2156381 |
| experimental infection of ponies with equine influenza (h3n8) viruses by intranasal inoculation or exposure to aerosols. | infection of seronegative welsh mountain ponies was established by intranasal instillation or exposure to nebulised aerosol of egg grown h3n8 viruses. pyrexia and coughing were noted following intranasal instillation and high titres of virus were recovered from the nasopharynx. exposure to aerosol resulted in more severe clinical signs characterised by high temperatures, dyspnoea, anorexia and coughing; lower levels of virus were recovered from the nasopharynx. the severity of clinical signs and ... | 1990 | 2156688 |
| immune response to oil-emulsion vaccines with single or mixed antigens of newcastle disease, avian influenza, and infectious bronchitis. | inactivated newcastle disease virus (ndv), avian influenza virus (aiv), and infectious bronchitis virus (ibv) antigens were evaluated for immunological efficacy in monovalent and polyvalent vaccines. vaccinated broilers were bled for hemagglutination-inhibition (hi) tests at 1- or 2-week intervals. half of the chickens were challenged with the largo isolate of velogenic viscerotropic (vv) ndv at 8 weeks post-vaccination, and the remainder were challenged with the massachusetts 41 strain ibv at 9 ... | 1990 | 2157390 |
| prevention and control of influenza. recommendations of the immunization practices advisory committee (acip) | | 1990 | 2159107 |
| [vaccinations in pigs]. | efficacious and safe gi-negative vaccines are available for vaccination against aujeszky's disease. an intensive vaccination programme carried out consistently will result in the reduction of virus circulating among pig populations. combined vaccination and culling of gi-seropositive pigs may lead to eradication of aujeszky's disease virus in a stock. vaccination of susceptible gilts, sows and boars against parvovirus infections is advisable. the actual period for which a sow is protected agains ... | 1990 | 2161569 |
| resistance to influenza virus and vesicular stomatitis virus conferred by expression of human mxa protein. | mxa and mxb are interferon-induced proteins of human cells and are related to the murine protein mx1, which confers selective resistance to influenza virus. in contrast to the nuclear murine protein mx1, mxa and mxb are located in the cytoplasm, and their role in the interferon-induced antiviral state was unknown. in this report we show that transfected cell lines expressing mxa acquired a high degree of resistance to influenza a virus. surprisingly, mxa also conferred resistance to vesicular st ... | 1990 | 2161946 |
| bovine and mouse serum beta inhibitors of influenza a viruses are mannose-binding lectins. | normal bovine and mouse sera contain a component, termed beta inhibitor, that inhibits the infectivity and hemagglutinating activity of influenza a viruses of the h1 and h3 subtypes. to investigate the nature of the interaction of beta inhibitors with influenza a viruses we isolated a mutant of the virus mem71h-beln (h3n1) that could grow in the presence of bovine serum. the mutant virus was resistant to hemagglutination inhibition by mouse serum as well as by bovine serum and had undergone chan ... | 1990 | 2162043 |
| new acquisitions in the chemotherapy of viral infections. | the development of new antiviral agents has gained increasing momentum. it has kept pace with the identification of specific sites ("targets") in the virus replicative cycle at which potential antiviral drug can interact. the current armamentarium of available antiviral drugs consists of amantadine and rimantadine (against influenza a), ribavirin (against respiratory syncytial virus infection), idoxuridine and trifluridine (against herpetic keratitis), vidarabine and acyclovir (against herpes si ... | 1990 | 2162118 |
| [morphometric analysis of immunologic deficiency in newborn mice developing after transplacental transmission of live or inactivated influenza a virus]. | morphometric evaluation of the thymus and spleen was used to characterize the complex immunological deficiency in suckling mice developing as a result of transplacental transmission of both live and inactivated influenza virus. | 1990 | 2163566 |
| polarized sorting of viral glycoproteins to the axon and dendrites of hippocampal neurons in culture. | cultured hippocampal neurons were infected with a temperature-sensitive mutant of vesicular stomatitis virus (vsv) and a wild-type strain of the avian influenza fowl plague virus (fpv). the intracellular distribution of viral glycoproteins was monitored by immunofluorescence microscopy. in mature, fully polarized neurons the vsv glycoprotein (a basolateral protein in epithelial mdck cells) moved from the golgi complex to the dendritic domain, whereas the hemagglutinin protein of fpv (an apically ... | 1990 | 2163770 |
| rapid diagnosis of equine influenza. | during an epizootic of equine influenza in norway caused by influenza a/equine (h3n8) virus the efficacy of rapid virus diagnosis by the indirect immunofluorescence technique was evaluated. the antiserum used in the test was a polyclonal influenza a virus antiserum with reactivity directed mainly against the common nucleoprotein and matrix protein. this antiserum possessed sufficient reactivity for the detection of virus-infected exfoliated nasopharyngeal cells. nasopharyngeal smear samples from ... | 1990 | 2164275 |
| fusion-mediated microinjection of liposome-enclosed dna into cultured cells with the aid of influenza virus glycoproteins. | influenza viruses were able to mediate fusion of dna-loaded liposomes with living cultured cells such as monkey cos-7 cells. this was inferred from the appearance of cat activity in recipient cells incubated with the combination of influenza viruses and liposomes loaded with the plasmid psv2cat. influenza virions were found to be as efficient as intact sendai virions in mediating microinjection of foreign dna into living cells. also, reconstituted envelopes bearing either influenza glycoproteins ... | 1990 | 2164484 |
| effect of influenza virus strains on lipid metabolism of infected hek cells. | we have shown previously that in infected hel cells varicella-zoster virus (vzv) causes a shift from polar to neutral lipid synthesis and that some strains of the virus depressed total lipid synthesis. in this report we show that vzv produces a similar effect on the lipid metabolism of infected human embryonic kidney cells. the pattern of lipid synthesis in human embryonic kidney cells infected with either of two strains of influenza type a virus was similar to that of control uninfected cells, ... | 1990 | 2165041 |
| alterations in influenza a virus specific immune injury in mice anesthetized with halothane or ketamine. | cd-1 mice infected with a sublethal dose of influenza a virus were anesthetized for 2 h with halothane. these mice were compared to a control group which was similarly infected using ketamine sedation. mice anesthetized with halothane showed less physical signs of illness and demonstrated less lung histopathology than the control group of mice. virus titers were reduced in the group of animals exposed to halothane 12 h after infection, but were the same as the infected controls at all other time ... | 1990 | 2165044 |
| human malignant melanoma cell line (hmv-ii) for isolation of influenza c and parainfluenza viruses. | hmv-ii, a human malignant melanoma cell line, was compared with other cell lines (mdck, vero, and llc-mk2) and primary cultures of monkey kidney (pmk) cells for the isolation and quantification of influenza and parainfluenza viruses. hmv-ii cells were superior to mdck and llc-mk2 cells in quantification of the influenza c virus and were used successfully in the isolation of the virus from clinical specimens. the hmv-ii cell line was also more sensitive for isolating parainfluenza viruses from cl ... | 1990 | 2166075 |
| sequential virus infections, bacterial superinfections, and fibrogenesis. | parainfluenza 1 (sendai) and influenza a virus pneumonitis cause severe lung damage, which, upon resolution, is followed by persistent alveolitis and parenchymal changes characterized by patchy consolidation and collagen deposition in the affected areas. to determine whether these long-term sequelae of the virus pneumonias are cumulative, mice were infected by aerosol inhalation with sendai virus, influenza a virus, or sendai followed 30 days later by influenza virus infection. at 90 days after ... | 1990 | 2166456 |
| effects of chicken embryo age on time to death following infection by avian influenza viruses: implications for distinguishing highly pathogenic isolates. | when white leghorn (wl) chick embryos ranging in age from 8 to 13 days were inoculated with a variety of avian influenza virus (aiv) isolates, strain-specific differences in embryo mean death times (mdt) were observed. non-highly pathogenic (nhp) strains killed 8 or 9 day-old embryos much more rapidly than 12 or 13 day-old embryos. highly pathogenic (hp) strains, however, were less sensitive to embryo age resulting in similar mdts in both older and younger embryos. these observations were consis ... | 1990 | 2166979 |
| close relationship between mink influenza (h10n4) and concomitantly circulating avian influenza viruses. | strains of an influenza h10n4 virus have been isolated during an outbreak of a respiratory disease in mink on the south-east coast of sweden. this was the first example of a disease in mammals caused by the h10 subtype. we compared the a/mink/sweden/84 strain with two recent avian h10n4 isolates, one from fowl and another from a mallard, both isolated in great britain in 1985 as well as the prototype a/chicken/germany/n/49 (h10n7). the comparison was carried out by genomic analysis of the strain ... | 1990 | 2167060 |
| synthesis and antiviral activity of 3'-deoxy-3'-c-hydroxymethyl nucleosides. | a series of 3'-branched-chain sugar nucleosides, in particular 3'-deoxy-3'-c-hydroxmethyl nucleosides, have been synthesized and evaluated as antiviral agents. reaction of 1-(2,3-epoxy-5-o-trityl-beta-d-lyxo-pentofuranosyl) derivatives 12 and 13, of uracil and thymine, respectively, with 5,6-dihydro-2-lithio-5-methyl-1,3,5-dithiazine 14 afforded the corresponding 3'-functionalized nucleosides 15 and 16, respectively. replacement of the trityl group with tertbutyldiphenylsilyl allowed high yieldi ... | 1990 | 2167981 |
| anti-viral immunity induced by recombinant nucleoprotein of influenza a virus. iii. delivery of recombinant nucleoprotein to the immune system using attenuated salmonella typhimurium as a live carrier. | a plasmid encoding the influenza nucleoprotein gene from a/nt/60/68 virus was transduced into the attenuated salmonella typhimurium aroa- strain sl3261. the bacterial vector expressing the viral gene product was able to induce both humoral and cell-mediated immune responses to the nucleoprotein antigen. cd4+ virus-specific t cells capable of proliferation were readily induced and, in some circumstances, class ii major histocompatibility complex (mhc)-restricted cytotoxicity was detected. however ... | 1990 | 2168340 |
| the immunogenicity of vp7, a rotavirus antigen resident in the endoplasmic reticulum, is enhanced by cell surface expression. | the glycoprotein vp7, the major serotype antigen of rotaviruses, is localized to the endoplasmic reticulum (er) of the cell, where it is retained as a membrane-associated protein before assembly into mature virus particles. wild-type vp7 expressed by a recombinant vaccinia virus was also located internally and was poorly antigenic. using recombinant techniques, a correctly processed, secreted form of vp7 (s.c. stirzaker and g.w. both, cell 56:741-747, 1989) was modified by addition to its c term ... | 1990 | 2168965 |
| epidemic of fever of unknown origin in rural thailand, caused by influenza a (h1n1) and dengue fever. | in the late summer (rainy season) of 1987, a sharp outbreak of fever of unknown origin (fuo) in rural southern thailand was investigated by a field epidemiology team. in a random survey of households, 40 percent of the children and 20 percent of adults were reported to have had febrile illnesses within the last month. there was at least one death, possibly from reye's syndrome. testing 34 pairs of acute and convalescent sera showed significant hi antibody titer rises to influenza a (taiwan/(h1n1 ... | 1990 | 2169651 |
| examination of sera from game birds for antibodies against avian viruses. | | 1990 | 2171182 |
| successful competition in translation by the flavivirus kunjin with poliovirus during co-infections in vero cells. | infection with poliovirus effectively inhibited the translation of vero cell messengers (carrying type 1 or type 2 caps at the 5' end) and of influenza virus messengers (type 1 caps) in co-infections. in contrast, kunjin virus rna (type 1 caps) and semliki forest virus rna (a togavirus, with type 0 caps) continued to be translated in the presence of co-infecting poliovirus. translation of kunjin virus rna was also unaffected during co-infections with either influenza virus or semliki forest viru ... | 1990 | 2171465 |
| fluorescence anisotropy of viruses treated with formaldehyde and dimethyl-sulfoxide. | the fluorescence anisotropy changes observed in a-1 (h1n1) influenza and sendai parainfluenza viruses in aqueous suspensions when formaldehyde (0.1 to 1.0 p.c.) and dimethyl-sulfoxide (0.3 to 5.0 p.c.) were added, using both intrinsic fluorescence of viral proteins and that of the membrane fluorescent probe--dph, showed significant differences with regard to the virus and the history of the suspensions used, allowing under rigorous standardized conditions the use of fluorescence anisotropy measu ... | 1990 | 2171626 |
| amantadine attack on influenza a. | | 1990 | 2172115 |
| anti-viral immunity induced by recombinant nucleoprotein of influenza a virus. ii. protection from influenza infection and mechanism of protection. | protection against influenza a virus infection in mice immunized with recombinant nucleoprotein (rnp) was studied. nucleoprotein-immune mice were protected against a lethal challenge with a/puerto rico/8/34 (a/pr8) virus but showed considerable morbidity before recovery. local boosting of the immune system with rnp by intranasal immunization improved the protection in np-immune mice, and the decrease in morbidity after infection was reflected in accelerated clearance of virus from lungs. however ... | 1990 | 2172156 |
| an outbreak of acute gastroenteritis caused by a small round structured virus in a geriatric convalescent facility. | an outbreak of acute gastroenteritis (age) occurred in a 201-bed geriatric convalescent facility in los angeles county during december 1988 through january 1989. the attack rate was 55% among residents and 25% among employees. illnesses were characterized by vomiting and diarrhea to a lesser extent, and the absence of fever. bacterial and parasitic tests in a sample of patients were negative. a 27 nm small round structured virus (srsv) was identified in one of 30 stools studied by immune electro ... | 1990 | 2172363 |
| activity of rat mx proteins against a rhabdovirus. | upon stimulation with alpha/beta interferon, rat cells synthesize three mx proteins. sequence analysis of corresponding cdnas reveals that these three proteins are derived from three distinct genes. one of the rat cdnas is termed mx1 because it is most closely related to the mouse mx1 cdna and because it codes for a nuclear protein that, like the mouse mx1 protein, inhibits influenza virus growth. however, this protein differs from mouse mx1 protein, in that it also inhibits vesicular stomatitis ... | 1990 | 2173790 |
| acute bronchitis in the community: clinical features, infective factors, changes in pulmonary function and bronchial reactivity to histamine. | a descriptive study of acute bronchitis in patients without pre-existing pulmonary disease was undertaken in the community during the winter months of 1986-87. forty-two episodes were investigated in 40 individuals. the cardinal symptom was the acute onset of cough (100%), usually productive (90%). wheezing was noted by 62% of patients, but heard on auscultation in only 31%. a potential pathogen was isolated in 29% of cases with a virus (eight cases) being identified more frequently than either ... | 1990 | 2174179 |
| an elisa for detection of antibodies against influenza a nucleoprotein in humans and various animal species. | a double antibody sandwich blocking elisa, using a monoclonal antibody (mab) against influenza a nucleoprotein (np) was developed to detect antibodies against influenza. collections of serum samples were obtained from human and various animal species. all influenza a subtypes induced antibodies against hemagglutinins and np. a close correlation between titers of the hemagglutination inhibition (hi) test and the np-elisa was seen. antibodies against influenza np were demonstrated in serum samples ... | 1990 | 2174233 |
| removal of pathogenic human viruses by insoluble pyridinium-type resin. | cross-linked poly(n-benzyl-4-vinylpyridinium bromide) (bvp resin) was found to be very efficient in removing pathogenic human viruses from aqueous solution. in batch removal experiments using 50 g/l of bvp resin at 35 degrees c, the level of infectivity in suspensions of enterovirus, herpes simplex virus, poliovirus, and human immunodeficiency virus was reduced 1000-100,000 fold during a 2 h period. those of coxsackievirus and echovirus were reduced 60-600 fold during 1 h contact. the haemagglut ... | 1990 | 2174373 |
| new method for titration of virus infectivity by immunostaining. | we have developed a new method for titration of viruses utilizing automated microtiter technology. compared to existing methods such as plaque assay or hemagglutination titration of influenza virus, the new method offers distinct advantages in terms of time and effort. in addition because multiple replicates can easily be employed accuracy can be increased. | 1990 | 2175196 |
| [a morphological study of pneumopathies caused by associated para-influenza and influenza viruses]. | histological examination of lungs collected from mice inoculated with influenza a/pr 8/34 (h0n0) and/or parainfluenza type 3 viruses revealed the existence of lymphohistiocytic interstitial bronchopneumonia lesions. necrosis zones were found in the lungs of influenza virus infected animals. associated infection by the two viruses induced also the fibroblast and fibrocyte proliferation, at same average ratios. | 1990 | 2176531 |
| [the incidence of influenzal, para-influenzal and adenoviral antigens in keratoconjunctivitis patients during immunization with nivgrip vaccine]. | repeated intranasal administrations of nivgrip, influenza inactivated vaccine, to patients with chronic recurrent keratoconjunctivitis, led to a significant reduction of respiratory virus incidence, as revealed by the immunofluorescence test in the conjunctive epithelial cells. the effect is probably due to endogenous interferon stimulation by the vaccine, at the nasopharyngeal level. | 1990 | 2176535 |
| molecular evolution of human t-cell leukemia virus. | phylogenetic trees for the human t-cell leukemia virus type i (htlv-i) and its related viruses were constructed by use of nucleotide sequences of the long terminal repeat (ltr) and the tax gene. the trees showed that the viruses diverged from a common ancestral virus and that they are classified into two groups whose hosts are either primates or bovines. however, the topology of the trees for the viruses differed from that for the hosts. this suggests that htlv-i and htlv-i-related viruses evolv ... | 1990 | 2176698 |
| isolation and identification of viral agents in argentinian children with acute lower respiratory tract infection. | from a total population of 1,002 children with acute lower respiratory infection (alri), identification of virus was achieved in 304 cases. in this survey, 1,000 nasopharyngeal aspirate and 13 lung tissue samples were tested in four cell lines (hep-2, mrc-5, mdck, and llc-mk2) and by indirect immunofluorescence (iif), while 242 paired sera were studied by complement fixation. respiratory syncytial virus (rsv) was the most frequently detected agent (n = 183), followed by adenovirus (n = 28), para ... | 1990 | 2176736 |
| a hospital-based study of acute viral infections of the respiratory tract in thai children, with emphasis on laboratory diagnosis. | the hospital-based study described here examined the viruses found in 738 children less than 5 years old who presented at ramathibodi hospital, bangkok, thailand, from january 1986 to december 1987 with acute respiratory tract infections. three methods for detection of viral infection are compared: direct examination of epithelial cells of the respiratory tract with the use of fluorescent antibody staining, isolation of virus, and measurement of antibody in acute- and convalescent-phase sera. vi ... | 1990 | 2176738 |
| sero-epidemiological screening of pig sera collected at the slaughterhouse to detect herds infected with aujeszky's disease virus, porcine influenza virus and actinobacillus (haemophilus) pleuropneumoniae in the framework of an integrated quality control (iqc) system. | over a period of six months, approximately 4700 blood samples were collected from 97 pig-finishing farms in the provinces of noord-brabant and gelderland and screened for antibodies with respect to aujeszky's disease virus (adv), porcine influenza virus (pi) and actinobacillus (haemophilus) pleuropneumoniae (app). there were significant differences in the percentages of seropositive pigs between the two provinces, which may be related to the difference in the density of the pig population in the ... | 1990 | 2176752 |
| diagnosis of swine influenza with an immunofluorescence technique using monoclonal antibodies. | direct diagnosis of swine influenza infection by an indirect immunofluorescence technique using anti-nucleoproteine monoclonal antibody was compared with virus isolation. five 8-week-old pigs were inoculated with 2 x 10(7) eid50 of strain a h1n1sw/4115/85. clinical signs developed in only three pigs. antigen was detected in nasal epithelial cells obtained from all animals the first day after inoculation; the antigen was detected in one pig 6 days after the infection. fluorescence was present in ... | 1990 | 2176753 |
| evidence for a direct role for sialic acid in the attachment of encephalomyocarditis virus to human erythrocytes. | sialic acid residues are required in cellular receptors for many different mammalian viruses. sialic acid could have a direct role, being an integral part of the virus binding site on the receptor. alternatively, negatively charged sialic acid could have an indirect role, being responsible for holding the receptor in the required configuration for virus recognition, for instance, by interacting with positively charged amino acid residues found in the polypeptide chain of receptors. we have inves ... | 1990 | 2176879 |
| mm 46115, a new antiviral antibiotic from actinomadura pelletieri. characteristics of the producing cultures, fermentation, isolation, physico-chemical and biological properties. | six strains of actinomadura pelletieri were shown to produce a novel macrolide antibiotic, designated mm 46115. mm 46115 was active against parainfluenza virus 1 and 2 and gram-positive bacteria. methods are described for the production of mm 46115 by strain ip 729.63, and for the isolation of the compound from a butanol extract of the culture filtrate. | 1990 | 2177052 |
| influenza a and rhabdomyolysis. | a case of influenza a h3n2 resulting in unusually severe rhabdomyolysis and myoglobinuria is described. although a rare complication of viral infection, prompt treatment with intravenous fluids can prevent the serious complications which may follow. | 1990 | 2177078 |
| heptad repeat sequences are located adjacent to hydrophobic regions in several types of virus fusion glycoproteins. | extensive regions of heptad repeat units consistent with an alpha-helical coiled coil conformation are located adjacent to hydrophobic, potentially fusion-related regions in the amino acid sequences of paramyxovirus fusion and retrovirus envelope glycoproteins. similar arrangements of hydrophobic peptides and heptad repeat units exist in coronavirus peplomer proteins and influenza virus haemagglutinins. this suggests that there may be similarities in the structures of these proteins and in the f ... | 1990 | 2177097 |
| in vivo manipulation of igg2a production by isotype-specific autoantibodies. | repeated intranasal infection of balb/c mice with a/pr/8 influenza virus induced an intense antiviral igg response dominated by the igg2a subclass, and accompanied by the appearance of igg2a reactive autoantibodies. cells producing igg2a reactive autoantibodies could then be cloned as hybridomas from the virus infected animals. monoclonal antibodies produced by selected hybridomas u28, z26 and z41 produced igm-type antibodies with strong specificity for the igg2a isotype bearing "a" allotypic de ... | 1990 | 2177147 |
| intracellular transport of soluble and membrane-bound glycoproteins: folding, assembly and secretion of anchor-free influenza hemagglutinin. | the influenza hemagglutinin precursor (ha0) and many other glycoproteins fold and oligomerize in the endoplasmic reticulum (er). only correctly folded oligomers are transported to the cell surface. to analyse the rules which determine this type of er sorting, we have extended our analysis of hemagglutinin transport to two soluble, anchor-free recombinant ha0s derived from x31/a/aichi/68 and a/japan/305/57 influenza a. the results showed that individual monomers rapidly acquired a folded structur ... | 1990 | 2178922 |
| differential interaction of virulent and attenuated influenza virus strains with ferret alveolar macrophages: possible role in pathogenicity. | the ferret provides a unique model for the study of human influenza. the interaction between alveolar macrophages and virus strains with different levels of virulence was examined in vitro. the greater virulence of wild-type a strains over type b and c viruses was reflected in the higher production of infectious virus progeny and subsequent cytopathology, even though the expression of viral antigens was equivalent for all strains tested. these included a/ann arbor/6/60 (h2n2) and a/rochester/1/8 ... | 1990 | 2181032 |
| use of live cold-adapted influenza a h1n1 and h3n2 virus vaccines in seropositive adults. | to investigate the immunogenicity and protective efficacy of cold-adapted influenza vaccine in individuals with underlying immunity to influenza a virus, we administered cold-adapted h1n1 and h3n2 vaccines to adults with prevaccination serum hemagglutination inhibition antibody titers of 1:16 or more and challenged them 1 month afterwards with homologous wild-type influenza a virus. both cold-adapted vaccines were immunogenic in seropositive adults. in addition, individuals receiving cold-adapte ... | 1990 | 2182673 |
| the expression of influenza virus hemagglutinin in the pancreatic beta cells of transgenic mice results in autoimmune diabetes. | insulin-dependent diabetes mellitus results from the autoimmune destruction of the insulin-producing beta cells of the pancreatic islets. the target antigen(s) involved in this immunopathological process has not been identified. our strategy was to determine whether expression of a novel surface antigen by murine pancreatic beta cells would result in insulin-dependent diabetes mellitus. we have generated lines of transgenic mice (rip-ha) that express the hemagglutinin of the a/japan/305/57 strai ... | 1990 | 2185889 |
| bacterial pneumonia in solid organ transplantation. | approximately 4% of recipients of solid organ transplants in the united states develop bacterial pneumonia in the posttransplant period, often in the first 3 months following transplantation. the incidence of bacterial pneumonia is highest in recipients of heartlung (22%) and liver transplants (17%), intermediate in recipients of heart transplants (5%), and lowest in renal transplant patients (1 to 2%). the crude mortality of bacterial pneumonia in solid organ transplantation has exceeded 40% in ... | 1990 | 2188317 |
| [laboratory diagnosis of respiratory syncytial virus infection]. | we study 18 children with acute respiratory infection diagnosed early by direct immunofluorescence (dif) using monoclonal antibodies to synticial respiratory virus (srv). antibodies to adenovirus, influenza virus a and b, parainfluenza virus 1, 2 and 3, mycoplasma, q fever, herpes and cytomegalovirus (cmv) are also studied. we consider that in most cases the diagnosis of infections caused by srv cannot be established by complement fixation, and should be accompanied by some antigen detection tec ... | 1990 | 2189329 |
| peptide binding to hla-dr1: a peptide with most residues substituted to alanine retains mhc binding. | major histocompatibility complex (mhc) glycoproteins play an important role in the development of an effective immune response. an important mhc function is the ability to bind and present 'processed antigens' (peptides) to t cells. we show here that the purified human class ii mhc molecule, hla-dr1, binds peptides that have been shown to be immunogenic in vivo. detergent-solubilized hla-dr1 and a papain-cleaved form of the protein lacking the transmembrane and intracellular regions have similar ... | 1990 | 2189723 |
| generation of seal influenza virus variants pathogenic for chickens, because of hemagglutinin cleavage site changes. | influenza virus a/seal/mass/1/80 (h7n7) was adapted to grow in mdck cells and chicken embryo cells (cec) in the absence of exogenous protease. the biological properties of the virus variants obtained coincided with intracellular activation of the hemagglutinin (ha) by posttranslational proteolytic cleavage and depended on the cell type used for adaptation. mdck cell-adapted variants contained point mutations in regions of the ha more distant from the cleavage site. it is proposed that these muta ... | 1990 | 2191148 |
| [genetic basis for construction of the life influenza type a vaccine using temperature-sensitive mutants]. | published data and authors' original material on the use of temperaturesensitive influenza virus mutants (ts) as donors in attenuation process aimed at obtaining the recombinant live influenza vaccines (liv) are reviewed. the so called cold adapted ts donors are shown to be superior for this aim. the data are presented in the review on the association of the mutations in the genome of cold adapted donors with attenuation, on the reactivity, immunogenicity and genetical stability of the recombina ... | 1990 | 2194119 |
| transgenic mice with intracellular immunity to influenza virus. | we have generated transgenic mice that express the intracellular anti-influenza virus protein mx1 under control of an interferon-responsive regulatory element. upon infection with influenza virus, mice of a high responder line produce mx1 protein locally at the sites of initial viral replication, exhibit little viral spread, and survive infection. mice of a low responder line show more extensive viral spread and survive infection only when virus is given at high doses. to survive low dose infect ... | 1990 | 2194673 |
| replication of a waterfowl-origin influenza virus in the kidney and intestine of chickens. | intravenous inoculation of chickens with a waterfowl-origin type a influenza virus resulted in high titers of virus in kidney tissues and viral nucleoprotein in renal tubular epithelial cells and in intestinal mucosal epithelial cells. virus titers in kidneys of four of eight clinically normal chickens sampled on days 3 and 5 postinoculation (pi), one dead chicken on day 3 pi, and one dead chicken on day 7 pi exceeded 10(6) mean embryo infectious dose per gram of tissue. using immunofluorescent ... | 1990 | 2196043 |
| conformational changes and fusion activity of influenza virus hemagglutinin of the h2 and h3 subtypes: effects of acid pretreatment. | marked differences were observed between the h2 and h3 strains of influenza virus in their sensitivity to pretreatment at low ph. whereas viral fusion and hemolysis mediated by influenza virus x:31 (h3 subtype) were inactivated by pretreatment of the virus at low ph, influenza virus a/japan/305/57 (h2 subtype) retained those activities even after a 15-min incubation at ph 5.0 and 37 degrees c. fusion with erythrocytes was measured by using the octadecylrhodamine-dequenching assay with both intac ... | 1990 | 2196382 |
| function of two discrete regions is required for nuclear localization of polymerase basic protein 1 of a/wsn/33 influenza virus (h1 n1). | polymerase basic protein 1 (pb1) of influenza virus (a/wsn/33), when expressed from cloned cdna in the absence of other viral proteins, accumulates in the nucleus. we have examined the location and nature of the nuclear localization signal of pb1 by using deletion mutants and chimeric constructions with chicken muscle pyruvate kinase, a cytoplasmic protein. our studies showed some novel features of the nuclear localization signal of pb1. the signal was present internally within residues 180 to 2 ... | 1990 | 2196448 |
| comparison of live attenuated cold-adapted and avian-human influenza a/bethesda/85 (h3n2) reassortant virus vaccines in infants and children. | randomized, placebo-controlled studies with 10(3)-10(7) 50% tissue-culture infectious dose (tcid50) of avian-human (ah) and cold-adapted (ca) influenza a/bethesda/85 (h3n2) reassortant viruses were completed in 106 seronegative young children 6-48 months of age. although the reassortants differed in six of eight rna segments, they exhibited similar properties in level of attenuation, infectivity, immunogenicity, and efficacy. the 50% human infectious dose was 10(4.6) tcid50 for ah and 10(4.4) fo ... | 1990 | 2197335 |
| expression of influenza a and b virus nucleoprotein antigens in baculovirus. | full-length cdna clones of the nucleoprotein (np) genes of influenza a/ann arbor/6/60 and b/ann arbor/1/86 viruses were constructed from virion rna and subsequently expressed in spodoptera frugiperda (sf9) cells using the baculovirus vector, autographa californica nuclear polyhedrosis virus. western blot analysis of lysates prepared from sf9 cells infected with the recombinant viruses confirmed that the baculovirus-expressed np antigens were reactive with monoclonal antibodies specific for eithe ... | 1990 | 2197370 |
| rapid detection of respiratory syncytial virus and influenza a virus in cell cultures by immunoperoxidase staining with monoclonal antibodies. | peroxidase-labeled monoclonal antibodies against respiratory syncytial virus (rsv) and influenza a virus were used for immunoperoxidase staining (ips) of cell cultures inoculated with nasopharyngeal aspirates. cells were grown in 24-well plates, and specimens were inoculated by low-speed centrifugation. cultures were incubated for 2 days at 37 degrees c and then fixed, stained, and observed by light microscopy. ips was compared with standard virus isolation by using cultures of human diploid fib ... | 1990 | 2199488 |
| [influenza viruses studied by fluorescent immunoassay with temporary resolution]. | monoclonal antibodies, epidemic strains of influenza a and b viruses, conjugates were studied by fluorescence immunoassay with temporary resolution using equipment of different companies. differences and specificity of monoclonal antibodies to influenza a and b viruses were demonstrated. the highest sensitivity of the method with the test system used was determined, being 20 ng/ml of viral protein. the method was shown to be useful for influenza virus detection both in solutions containing purif ... | 1990 | 2202151 |
| sensitive enzyme immunoassay for the rapid diagnosis of influenza a virus infections in clinical specimens. | samples of nasopharyngeal secretion (nps) from 100 infants and small children admitted for acute respiratory disease during the period from january to march 1989 were examined for the presence of influenza a virus. all samples were tested by enzyme immunoassay (eia), fluorescent antibody (fa) technique and by isolation in cell culture 3-6 h after they were obtained from the patients. of 24 influenza strains found by isolation, 21 were detected by eia and 19 were fa+. in comparison with virus iso ... | 1990 | 2203125 |
| 4-methylumbelliferyl-alpha-glycosides of partially o-acetylated n-acetylneuraminic acids as substrates of bacterial and viral sialidases. | 4-o-acetylated, 7-o-acetylated, and 9-o-acetylated 4-methylumbelliferyl-alpha-n-acetyl-neuraminic acids (neu4,5ac2-mu, neu5,7ac2-mu, neu5,9ac2-mu) were tested as substrates of sialidases of vibrio cholerae and of clostridium perfringens. both sialidases were unable to hydrolyse neu4,5ac2-mu. this compound at 1 mm concentration did not inhibit significantly the cleavage of neu5ac-mu, the best substrate tested. the 4-o-acetylated sialic acid glycoside is hydrolysed slowly by the sialidase from fow ... | 1990 | 2206459 |
| specific structural alteration of the influenza haemagglutinin by amantadine. | amantadine hydrochloride specifically blocks the release of virus particles from h7 influenza virus infected cells. this appears to be the direct consequence of an amantadine induced change in the haemagglutinin (ha) to its low ph conformation. the effect is indirect and mediated via interaction of the drug with the m2 protein since mutants altered in this component alone are insensitive to amantadine. the timing of drug action, some 15-20 min after synthesis, and its coincidence with proteolyti ... | 1990 | 2209554 |
| epidemiological analysis of acute respiratory disease (ard) and characteristics of the influenza epidemic in bohemia during the season 1986/1987. | the authors analyze the findings of epidemiological and virological surveillance of ard in bohemia during the season 1986/1987. in all, 57.5% of the czech population was affected by acute respiratory disease (ard). there were 5,950,832 cases reported, 124,444 complications (2.1% of the overall morbidity rate) and 5,374 deaths due to influenza, bronchitis, pneumonia and chronic pulmonary affection. the influenza epidemic commenced during the 48-th calendary week (cw) and lasted 5 weeks till the 5 ... | 1990 | 2212637 |
| influenza b virus mrna synthesis in vivo: efficient transcription of vrnas 1, 2 and 3. | influenza b virus genomic rna (vrna) segments encoding polymerase proteins were shown to be efficiently transcribed in vivo, unlike those of influenza a virus. the results are discussed in connection with the primary structure of the 3' ends of vrna segments. | 1990 | 2212997 |
| nebulized albuterol in acute bronchiolitis. | in a double-blind, placebo-controlled trial, 40 infants between 6 weeks and 24 months of age who had a first episode of wheezing and other signs and symptoms of bronchiolitis were randomly assigned to receive either nebulized albuterol (0.15 mg/kg/dose) or placebo (saline solution) for two administrations 1 hour apart. the albuterol therapy resulted in a significantly greater improvement in the accessory muscle score (decreases 0.70 vs decreases 0.30; p = 0.03), oxygen saturation (increases 0.71 ... | 1990 | 2213394 |
| determination of influenza virus proteins required for genome replication. | an artificial vaccinia virus vector-driven replication system for influenza virus rna has been developed. in this system, a synthetic ns-like gene is replicated and expressed by influenza virus proteins supplied through infection with vaccinia virus recombinant vectors. the minimum subset of influenza virus proteins needed for specific replication and expression of the viral ribonucleoprotein was found to be the three polymerase proteins (pb1, pb2, and pa) and the nucleoprotein. | 1990 | 2214032 |