Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “parainfluenza virus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,513 records · Page 84Linked to original sources
PubMed2004

[Acute respiratory tract infections due to a human metapneumovirus in children: descriptive study and comparison with respiratory syncytial virus infections].

BACKGROUND: A new paramyxovirus, the human metapneumovirus was recently isolated. We report the first French cases collected between 2000 and 2002. MATERIAL AND METHODS: Samples were obtained from nasopharyngeal aspirates from children hospitalised for acute respiratory tract infection in hospitals of Caen and Flers in Basse-Normandie. Human metapneumovirus was studied by polymerase chain reaction on negative samples for respiratory syncytial virus, influenza A and B virus, parainfluenza (1, 2 and 3) virus, adenovirus, coronavirus and rhinovirus. Comparison between metapneumovirus virus and respiratory syncytial virus infections was done after matching sex, age and infection month. RESULTS: Twenty-six human metapneumovirus infections were identified. A comparative study of a matched group of children infected by respiratory syncytial virus found no significative difference for hospitalisation motive, clinical criteria and treatment. CONCLUSION: The human metapneumovirus is responsible for typical acute bronchiolitis in children.

Acute Disease↗
PubMed2004

Surveillance of respiratory viral infections among pediatric outpatients in northern Taiwan.

BACKGROUND: Viruses are a frequent cause of upper respiratory tract infections in children. Like Taiwan, there were few virological surveillance systems for respiratory viral infections among children in developing countries. MATERIALS AND METHODS: During August 1995 and July 1997, 6-10 throat swab specimens per week were taken from pediatric outpatients with acute, febrile upper respiratory tract infections (URTI). The specimens were randomly obtained by two pediatricians at Chang Gung Children's Hospital and sent for virus isolation and identification. RESULTS: A total of 910 specimens were collected and 365 specimens (40%) were positive for at least 1 virus and included 81 enterovirus, 73 adenovirus, 58 influenza B virus, 54 influenza A virus, 48 cytomegalovirus (CMV), 25 herpes simplex virus-1 (HSV-1), 7 parainfluenza virus, 3 respiratory syncytial virus (RSV) and 16 mixed viruses. Adenovirus and enterovirus were identified throughout the study period. No seasonal variation was noted for adenovirus while enterovirus peaked between May and July and also during September and November. Influenza viruses, both A and B, were identified during two periods, respectively and altogether, influenza viruses could be detected almost throughout the year. An association between the virus type identified and the mean age of patients was found (P-value = 0.0001 by ANOVA test). The mean age of patients infected with influenza viruses, either A or B, was significantly higher than those of patients infected with adenovirus, HSV-1, CMV and enterovirus. CONCLUSION: The results of this study demonstrate that adenovirus and enterovirus are the two most common viruses isolated from pediatric outpatients with acute, febrile URTIs and can be identified throughout the year in northern Taiwan. Influenza viruses also can be identified throughout the year and during the epidemic, a child older than 5 years of age with acute febrile URTI is likely to be a case of influenza.

Adenoviridae↗
PubMed1996

Ambulatory patients with community-acquired pneumonia: the frequency of atypical agents and clinical course.

OBJECTIVES: To determine the etiology of community-acquired pneumonia in patients treated in an ambulatory setting, using serological methods, and to compare presenting symptoms, radiographic manifestations, and clinical outcomes of patients with pneumonia of "atypical" and undetermined etiology. PATIENTS AND METHODS: This prospective cohort study was conducted in emergency room and outpatient facilities of Victoria General Hospital, Halifax, Nova Scotia, and in offices of participating family doctors based in Halifax. One hundred forty-nine adults with acute onset of one or more symptoms or signs suggestive of pneumonia and radiographic evidence of pneumonia who provided informed consent were enrolled. Patients known to be HIV positive or who had been discharged from a hospital within the previous 10 days were ineligible for enrollment. Demographic features and clinical data were collected by direct patient interview and chart review by trained research nurses. Outcome measures included quantitative evaluation of pneumonia-specific symptoms, and responses to the Short Form 36 Health Survey at presentation and at 30 days after presentation. Information was also collected on each patient's health prior to pneumonia, as well as the time until each patient's self-reported return to work and to usual activities. The etiology of pneumonia was determined by testing acute and convalescent serum samples for antibodies to Legionella pneumophila serogroup 1, Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, Coxiella burnetii, adenovirus, respiratory syncytia virus, influenza viruses A and B, and parainfluenza viruses 1, 2, 3. RESULTS: The study population consisted of 149 patients, 54 (36%) of whom were men, with a mean age (+/- SD) of 41 +/- 15 years. An etiological diagnosis was made in 74 (49.7%) patients using serological methods. Etiological agents included M pneumoniae 34 (22.8%); C pneumoniae 16 (10.7%); M pneumoniae and C pneumoniae 5 (3.4%); C burnetii 4 (2.7%); influenza A virus 4 (2.7%); and other agents 6% (7.4%). Three patients (2%) had a conventional bacterial etiology, and 72 patients (48.3%) had pneumonia of undetermined etiology. Patients with pneumonia of known (atypical) and undetermined etiology were similar in terms of age, gender, race, education, employment, and comorbidity. Despite a higher proportion of patients with pneumonia of known etiology reporting sweats, chills, and headache at presentation, the two groups were similar for symptom severity and bother. The patients with pneumonia of undetermined etiology were more likely to have multilobar pneumonia (P < 0.02). Both patients with atypical pneumonia and those with pneumonia of undetermined etiology suffered severe deterioration of physical functioning with a marked but incomplete recovery at 30 days. Those with atypical pneumonia had higher physical functioning and general mental health scores at 30 days. CONCLUSIONS: Nearly half the cases of ambulatory community-acquired pneumonia are due to "atypical" agents. It is not possible to reliably distinguish patients with atypical pneumonia from those with pneumonia of undetermined etiology by clinical features at baseline. The outcomes in terms of resolution of symptoms, functional status, return to work, and return to usual activities are essentially similar in the two groups.

Adult↗
PubMedDate not supplied

Nosocomial viral infections: II. Guidelines for prevention and control of respiratory viruses, herpesviruses, and hepatitis viruses.

This article reviews the most likely mechanisms of transmission of the commonly encountered respiratory viruses (influenza, respiratory syncytial virus, parainfluenza, rhinovirus), herpesviruses, and hepatitis viruses, and presents the guidelines used currently for prevention and control that are in use at Strong Memorial Hospital.

Cross Infection↗
PubMed1985

Synthesis and antitumor and antiviral activities of a series of 1-beta-D-ribofuranosyl-5-halocytosine (5-halocytidine) cyclic 3',5'-monophosphates.

A series of 1-beta-ribofuranosyl-5-halocytosine cyclic 3',5'-monophosphates (1-4) has been prepared. Direct halogenation of cytidine 3',5'-monophosphate (cCMP) yielded the Cl, Br, and I compounds while 5-F-cCMP (1) was obtained on cyclization of the 5'-monophosphate. On in vitro testing of 1-4 against L1210 and P388 leukemias, only 1 showed significant low-level activity (ID50 = 3.1 X 10(-4) mmol/L). Derivatives 2-4 were inactive at 10(-1) mmol/L and also proved to have low viral ratings against a series of RNA and DNA virus strains in vitro. By contrast the 5-F-cCMP showed moderate activity against VV, HSV-1, and HSV-2 strains (VR = 0.6-0.9). Both 5-fluorocytidine and 5-fluorocytidine 5'-monophosphate had marked antiviral activity (VR = 1.0-2.1) with the above viruses as well as with parainfluenza virus type 3. The nucleoside and nucleotide also were more active than 5-F-cCMP against L1210 and P388 cells. However, comparison of the cytotoxicities and antiviral ED50 values of 5-F-cCMP, 5-fluorocytidine 5'-monophosphate, and 5-fluorocytidine suggests a potential therapeutic advantage for 5-F-cCMP. Possible rationales for these activities are discussed in terms of 5-F-cCMP and the corresponding 5'-monophosphate as potential prodrugs and as sources, following enzymatic deamination, of cytotoxic 5-fluorouridine or its 5'-monophosphate.

Animals↗
PubMed1999

Viral aetiology of lower respiratory tract infection in young Malaysian children.

OBJECTIVE: To study the viral aetiology of lower respiratory tract infection (LRTI) in young Malaysian children. METHODOLOGY: A retrospective review was performed of LRTI patients aged less than 24 months who were admitted to the University Malaya Medical Centre between 1982 and 1997. Respiratory viruses in their nasopharyngeal secretion were identified by indirect immunofluorescence, viral culture, or both. RESULTS: A total of 5691 children were included in the study. The mean age was 8.6 +/- 6.6 months and the M:F ratio was 1.6:1. The most common diagnosis was pneumonia (52%) followed by bronchiolitis (45%) and croup (2%). Positive viral isolation rate was 22.0%. Respiratory syncytial virus (RSV) was the commonest virus isolated (84%), followed by parainfluenza virus (8%), influenza virus (6%) and adenovirus (2%). Patients with positive virus isolation were younger (7.8 +/- 6.2 vs 8.7 +/- 6.7 months, P = 0.0001) and were more likely to have bronchiolitis. CONCLUSION: Young Malaysian children admitted with LRTI had a 22% viral isolation rate and RSV was the commonest virus isolated.

Bronchiolitis↗
PubMed2002

Viruses associated with outbreaks of equine respiratory disease in New Zealand.

AIM: To identify viruses associated with respiratory disease in young horses in New Zealand. METHODS: Nasal swabs and blood samples were collected from 45 foals or horses from five separate outbreaks of respiratory disease that occurred in New Zealand in 1996, and from 37 yearlings at the time of the annual yearling sales in January that same year. Virus isolation from nasal swabs and peripheral blood leukocytes (PBL) was undertaken and serum samples were tested for antibodies against equine herpesviruses (EHV-1, EHV-2, EHV-4 and EHV-5), equine rhinitis-A virus (ERAV), equine rhinitis-B virus (ERBV), equine adenovirus 1 (EAdV-1), equine arteritis virus (EAV), reovirus 3 and parainfluenza virus type 3 (PIV3). RESULTS: Viruses were isolated from 24/94 (26%) nasal swab samples and from 77/80 (96%) PBL samples collected from both healthy horses and horses showing clinical signs of respiratory disease. All isolates were identified as EHV-2, EHV-4, EHV-5 or untyped EHV. Of the horses and foals tested, 59/82 (72%) were positive for EHV-1 and/or EHV-4 serum neutralising (SN) antibody on at least one sampling occasion, 52/82 (63%) for EHV-1-specific antibody tested by enzyme-linked immunosorbent assay (ELISA), 10/80 (13%) for ERAV SN antibody, 60/80 (75%) for ERBV SN antibody, and 42/80 (53%) for haemagglutination inhibition (HI) antibody to EAdV-1. None of the 64 serum samples tested were positive for antibodies to EAV, reovirus 3 or PIV3. Evidence of infection with all viruses tested was detected in both healthy horses and in horses showing clinical signs of respiratory disease. Recent EHV-2 infection was associated with the development of signs of respiratory disease among yearlings [relative risk (RR)=2.67, 95% CI=1.59-4.47, p=0.017]. CONCLUSIONS: Of the equine respiratory viruses detected in horses in New Zealand during this study, EHV-2 was most likely to be associated with respiratory disease. However, factors other than viral infection are probably important in the development of clinical signs of disease.

Journal Article↗
PubMed2002

Equine respiratory viruses in foals in New Zealand.

AIMS: To identify the respiratory viruses that are present among foals in New Zealand and to establish the age at which foals first become infected with these viruses. METHODS: Foals were recruited to the study in October/ November 1995 at the age of 1 month (Group A) or in March/ April 1996 at the age of 4-6 months (Groups B and C). Nasal swabs and blood samples were collected at monthly intervals. Nasal swabs and peripheral blood leucocytes (PBL) harvested from heparinised blood samples were used for virus isolation; serum harvested from whole-blood samples was used for serological testing for the presence of antibodies against equine herpesvirus (EHV)-1 or -4, equine rhinitis-A virus (ERAV), equine rhinitis-B virus (ERBV), equine adenovirus 1 (EAdV-1), equine arteritis virus (EAV), reovirus 3 and parainfluenza virus type 3 (PIV3). Twelve foals were sampled until December 1996; the remaining 19 foals were lost from the study at various times prior to this date. RESULTS: The only viruses isolated were EHV-2 and EHV-5. EHV-2 was isolated from 155/157 PBL samples collected during the period of study and from 40/172 nasal swabs collected from 18 foals. All isolations from nasal swabs, except one, were made over a period of 2-4 months from January to April (Group A), March to April (Group B) or May to July (Group C). EHV-5 was isolated from either PBL, nasal swabs, or both, from 15 foals on 32 occasions. All foals were positive for antibodies to EHV-1 or EHV-4, as tested by serum neutralisation (SN), on at least one sampling occasion and all but one were positive for EHV-1 antibodies measured by enzyme-linked immunosorbent assay (ELISA) on at least one sampling occasion. Recent EHV-1 infection was evident at least once during the period of study in 18/23 (78%) foals for which at least two samples were collected. SN antibodies to ERBV were evident in 19/23 (83%) foals on at least one sampling occasion and 15/23 foals showed evidence of seroconversion to ERBV. Antibodies to ERAV were only detected in serum samples collected from foals in Group A and probably represented maternally-derived antibodies. Haemagglutination inhibition (HI) antibody titres 1:10 to EAdV-1were evident in 21/23 (91%) foals on at least one sampling occasion and 16/23 foals showed serological evidence of recent EAdV-1 infection. None of the 67 serum samples tested were positive for antibodies to EAV, reovirus 3 or PIV3. There was no clear association between infection with any of the viruses isolated or tested for and the presence of overt clinical signs of respiratory disease. CONCLUSIONS: There was serological and/or virological evidence that EHV-1, EHV-2, EHV-5, EAdV-1 and ERBV infections were present among foals in New Zealand. EHV-2 infection was first detected in foals as young as 3 months of age. The isolation of EHV-2 from nasal swabs preceded serological evidence of infection with other respiratory viruses, suggesting that EHV-2 may predispose foals to other viral infections.

Journal Article↗
PubMed2004

A 1-year experience with human metapneumovirus in children aged <5 years.

Human metapneumovirus (hMPV) is a recently discovered respiratory pathogen. We tested respiratory specimens for the presence of hMPV by reverse-transcription polymerase chain reaction. These specimens were obtained over a 1-year period from children aged <5 years and had negative results by the direct fluorescent antibody test for respiratory syncytial virus, influenza A and B, parainfluenza viruses 1-3, and adenovirus. Overall, 54 (8.1%) of 668 individuals tested positive for hMPV. During March and April of the study period, hMPV was detected in 17.6% and 25.0% of specimens tested, respectively. At least 2 distinct genotypes of hMPV circulated during the study period. Fever, tachypnea, cough, rhinorrhea, retractions of the chest wall, and wheezing were common findings. Of hMPV-positive children, 60.4% were aged <12 months. hMPV accounted for a small but significant proportion of respiratory-tract disease in infants and children.

Australia↗
PubMed1981

In vitro identification and characterization of a virus isolated from a dog with neurological dysfunction.

A virus, 78-238, isolated from the cerebrospinal fluid of a dog with neurological dysfunction, was characterized as a paramyxovirus. This conclusion was supported by viral cytopathic effects and morphological appearance of virions and nucleocapsids in infected cells. Nucleocapsids were found in the cytoplasm of all infected cells and in the nuclei of 0.001% of these cells. Growth curves revealed that a high percentage (>/=76%) of infectious progeny virus was cell released. Persistent infection of Vero cells with 78-238 showed a consistently high percentage of fluorescence-positive cells and a low proportion of hemadsorption-positive cells. Serological studies indicate that the virus was closely related to Simian virus 5 and reference canine parainfluenza virus.

Animals↗
PubMed1993

Isolation of seven respiratory viruses in shell vials: a practical and highly sensitive method.

The isolation of respiratory viruses in shell vials was compared with isolation in tube cultures in order to determine the sensitivity of the former, rapid method. Twenty of 21 influenza virus and 15 of 15 parainfluenza virus isolates were recovered in shell vials. One hundred twenty-seven of 138 respiratory syncytial virus isolates were detected in shell vials, but only 10 of 21 adenovirus isolates were positive by the rapid method. Shell vials are very effective for the diagnosis of respiratory viral infections, except for those caused by adenovirus.

Adenoviruses, Human↗
PubMed1996

Simultaneous rapid culture for four respiratory viruses in the same cell monolayer using a differential multicolored fluorescent confirmatory stain.

A simultaneous rapid culture for influenza virus types A and B, parainfluenza virus, and respiratory syncytial virus was developed in a 96-well plate format with a culture-confirmatory stain using multiple fluorescent tags. Performance characteristics were comparable to those of standard and/or single rapid-culture methods as shown by parallel testing of 590 fresh clinical specimens and retrospective testing of 190 previously positive frozen specimens. The quadruple culture required less specimen volume than separate cultures, was significantly quicker than standard tube culture, was less labor intensive than separate cultures, and was less expensive than the other methods.

Evaluation Studies as Topic↗
PubMed2001

Early detection of acute rhinovirus infections by a rapid reverse transcription-PCR assay.

The development of a rhinovirus (RV)-RNA-specific reverse transcription (RT)-PCR assay is complicated by the close homology between the RV and enterovirus (EV) genomes in the highly conserved 5'-noncoding region, which is chosen for primer design in most RT-PCR assays. We have developed a sensitive, rapid, and RV-specific nested RT-PCR assay and have used it to test nasopharyngeal aspirates from 556 patients presenting with acute respiratory tract infections. RV RNA was detected by nested RT-PCR not only in all of 52 samples that were RV positive by virus isolation methods but also in 124 of 367 samples that were negative by virus isolation methods and enzyme-linked immunosorbent assay (ELISA). In addition, in 23 of 137 samples that were positive for a different respiratory virus by virus isolation and/or ELISA, RV RNA was detected by RT-PCR. EVs, adenoviruses, respiratory syncytial viruses, coronaviruses, and influenza and parainfluenza viruses, including clinical isolates as well as stock viruses, were not amplified in our RV-specific RT-PCR assay, indicating that this assay was highly specific. The processing time was less than 2 days for the RT-PCR, as opposed to up to 2 weeks for virus isolation. These results indicate that nested RT-PCR is more sensitive than conventional methods for the detection of RV in patients experiencing acute respiratory tract infections and represents the only reliable tool for the early laboratory diagnosis of RV infections. This is especially important in light of new opportunities for therapy currently being developed.

Adolescent↗
PubMed2003

Suboptimal detection of influenza virus in adults by the Directigen Flu A+B enzyme immunoassay and correlation of results with the number of antigen-positive cells detected by cytospin immunofluorescence.

To provide 24-h influenza diagnosis for adults presenting to the emergency department, the Directigen Flu A+B enzyme immunoassay (EIA) was performed in the chemistry laboratory during the night shift. Nasopharyngeal swabs were retested by cytospin-enhanced direct immunofluorescence (DFA; SimulFluor respiratory screen) when the virology laboratory opened. The influenza EIA detected 16 influenza A virus infections, whereas cytospin-enhanced DFA detected 31 influenza A virus infections as well as 3 respiratory syncytial virus, 2 adenovirus, and 1 parainfluenza virus infections. A positive EIA result usually correlated with 50 or more influenza virus cells positive by DFA.

Adult↗
PubMed2005

Aetiological role of viral and bacterial infections in acute adult lower respiratory tract infection (LRTI) in primary care.

BACKGROUND: Lower respiratory tract infections (LRTI) are a common reason for consulting general practitioners (GPs). In most cases the aetiology is unknown, yet most result in an antibiotic prescription. The aetiology of LRTI was investigated in a prospective controlled study. METHODS: Eighty adults presenting to GPs with acute LRTI were recruited together with 49 controls over 12 months. Throat swabs, nasal aspirates (patients and controls), and sputum (patients) were obtained and polymerase chain reaction (PCR) and reverse transcriptase polymerase chain reaction (RT-PCR) assays were used to detect Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella pneumophila, influenza viruses (AH1, AH3 and B), parainfluenza viruses 1-3, coronaviruses, respiratory syncytial virus, adenoviruses, rhinoviruses, and enteroviruses. Standard sputum bacteriology was also performed. Outcome was recorded at a follow up visit. RESULTS: Potential pathogens were identified in 55 patients with LRTI (69%) and seven controls (14%; p<0.0001). The identification rate was 63% (viruses) and 26% (bacteria) for patients and 12% (p<0.0001) and 6% (p = 0.013), respectively, for controls. The most common organisms identified in the patients were rhinoviruses (33%), influenza viruses (24%), and Streptococcus pneumoniae (19%) compared with 2% (p<0.001), 6% (p = 0.013), and 4% (p = 0.034), respectively, in controls. Multiple pathogens were identified in 18 of the 80 LRTI patients (22.5%) and in two of the 49 controls (4%; p = 0.011). Atypical organisms were rarely identified. Cases with bacterial aetiology were clinically indistinguishable from those with viral aetiology. CONCLUSION: Patients presenting to GPs with acute adult LRTI predominantly have a viral illness which is most commonly caused by rhinoviruses and influenza viruses.

Acute Disease↗
PubMed2006

A single-season prospective study of respiratory viral infections in lung transplant recipients.

The frequency and complications of respiratory viral infections (RVI) were studied in 50 ambulatory lung transplant patients during a single winter season, using viral antigens, viral cultures and PCR of nasal washes or bronchoalveolar lavages. Patients' survival, episodes of acute rejection and occurrence of bronchiolitis obliterans (BO) or BO syndrome (BOS) were monitored for 1 yr after the study. Overall, 32 (64%) patients had 49 symptomatic episodes. Documented infections included eight due to respiratory syncytial virus (RSV), one due to parainfluenza virus (PIV) and 10 due to influenza (FLU). Four of the FLU infections were serological rises without symptoms. Overall, 17 (34%) patients had documented viral infection; four patients had lower respiratory involvement and two (one RSV, one PIV) were hospitalised for aerosolised ribavirin treatment. After 1 yr there were three (6%) deaths unrelated to RVI. BO or BOS had occurred in one (6%) out of 17 patients with and three (12%) out of 33 without RVI. Respiratory viruses infected one-third of ambulatory lung transplant recipients in a single season. In conclusion, respiratory viral infection was not associated with subsequent graft dysfunction. Larger prospective studies are required to better define the acute and long-term morbidity of these infections.

Adult↗
PubMedDate not supplied

Clinical patterns and seasonal trends in respiratory syncytial virus hospitalizations in São Paulo, Brazil.

The respiratory viruses are recognized as the most frequent lower respiratory tract pathogens for infants and young children in developed countries but less is known for developing populations. The authors conducted a prospective study to evaluate the occurrence, clinical patterns, and seasonal trends of viral infections among hospitalized children with lower respiratory tract disease (Group A). The presence of respiratory viruses in children's nasopharyngeal was assessed at admission in a pediatric ward. Cell cultures and immunofluorescence assays were used for viral identification. Complementary tests included blood and pleural cultures conducted for bacterial investigation. Clinical data and radiological exams were recorded at admission and throughout the hospitalization period. To better evaluate the results, a non- respiratory group of patients (Group B) was also constituted for comparison. Starting in February 1995, during a period of 18 months, 414 children were included- 239 in Group A and 175 in Group B. In Group A, 111 children (46.4%) had 114 viruses detected while only 5 children (2.9%) presented viruses in Group B. Respiratory Syncytial Virus was detected in 100 children from Group A (41.8%), Adenovirus in 11 (4.6%), Influenza A virus in 2 (0.8%), and Parainfluenza virus in one child (0.4%). In Group A, aerobic bacteria were found in 14 cases (5.8%). Respiratory Syncytial Virus was associated to other viruses and/or bacteria in six cases. There were two seasonal trends for Respiratory Syncytial Virus cases, which peaked in May and June. All children affected by the virus were younger than 3 years of age, mostly less than one year old. Episodic diffuse bronchial commitment and/or focal alveolar condensation were the clinical patterns more often associated to Respiratory Syncytial Virus cases. All children from Group A survived. In conclusion, it was observed that Respiratory Syncytial Virus was the most frequent pathogen found in hospitalized children admitted for severe respiratory diseases. Affected children were predominantly infants and boys presenting bronchiolitis and focal pneumonias. Similarly to what occurs in other subtropical regions, the virus outbreaks peak in the fall and their occurrence extends to the winter, which parallels an increase in hospital admissions due to respiratory diseases.

Adolescent↗
PubMed1995

A colorimetric LDH assay for the titration of infectivity and the evaluation of anti-viral activity against ortho- and paramyxoviruses.

A rapid and precise screening assay was developed for in vitro evaluation of anti-orthomyxo- and anti-paramyxovirus agents. The procedure is spectrophotometrical assessment for viability of cells via extracellular leakage of lactic dehydrogenase (LDH). HMV-II cells, a human melanoma cell line was found to be suitable for the titration of virus infectivity and screening of anti-viral agents for orthomyxo- and paramyxoviruses. Comparative titration of infectivity of stock viruses by the LDH and the MTT in site reduction of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) methods with HMV-II cells as well as plaque titration with MDCK, Vero and HeLa cells was carried out. The LDH method was comparable or more sensitive for influenza viruses (FLUV)-A, B, C, parainfluenza viruses (PFLUV)-1, 2 and less sensitive for PFLUV-3, mumps virus (MPSV), measles viruses (MLSV) and respiratory syncytial virus (RSV) than the plaque titration. The 50% effective concentration (EC50) of 1-beta-D-ribofuranosyl-1, 2, 4-triazol-3-carboxamide (ribavirin) and 5-ethynyl-1-beta-D-ribofuranosyl-imidazole-4-carboxamide (EICAR) against orthomyxo- and paramyxoviruses were examined comparatively by the LDH, MTT and plaque reduction (PR) methods. The EC50 values of FLUV-C and PFLUV-1 were able to be evaluated only by the LDH but not by the MTT and PR methods. The LDH method with HMV-II cells simplifies the assay procedure and permits the evaluation of a large number of compounds for anti-orthomyxo- and anti-paramyxoviruses activity in vitro.

Antiviral Agents↗