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 631 records · Page 35Linked to original sources

A fluorometric procedure for measuring the neuraminidase activity: its application to the determination of this activity in influenza and parainfluenza viruses.

A fluorometric procedure for quantitating the amount of N-acetylneuraminic acid enzymatically released by the neuraminidase activity from N-acetylneuraminyl-lactose (sialyl-lactose) has been developed. The liberated lactose is hydrolyzed with beta-galactosidase, and the released galactose is oxidized with galactose dehydrogenase and NAD+; finally, the NADH produced is measured by fluorometry (excitation at 340 nm and analysis of emitted light at 465 nm). The fluorometric assay is about 10-fold more sensitive than the spectrophotometric procedure that measures NADH at 340 nm. It readily measures amounts as little as 2 nmol of sialic acid, and does not require the use of radioactive isotopes. Interferences due to sucrose or other substances, which cause errors in some cases with the use of the periodate-thiobarbiturate method for neuraminidase activity determination, are avoided. The procedure reported here provides a sensitive, rapid, and relatively simple method (feasible with commercialized reagents) for measuring the neuraminidase activity not only in purified samples from different sources but also directly in biological materials such as viruses. The technique has been tested with some viruses recently isolated belonging to Orthomyxoviridae or Paramyxoviridae families, known to be rich in neuraminidase. Reciprocally, this method can also be employed for determining the sialic acid concentration in acylneuraminyl-lactose-containing compounds when using purified neuraminidase for hydrolysis.

Chemical Phenomena↗

Characterization of human parainfluenza virus type 2 RNAs in infected cells and by in vitro synthesis.

The RNA species synthesized in HPIV-2 infected CV-1 cells were identified and characterized. The largest RNA of approximately 5.5 x 10(6) in molecular weight (MW) based on electrophoretic mobility, was identified as the genomic RNA. The other small RNA species of MWs 2.4 x 10(6), 1.1 x 10(6), 0.77 x 10(6), 0.68 x 10(6) and 0.5 x 10(6) were identified as mRNAs. The five smallest RNAs were also synthesized in vitro and comigrated with RNAs synthesized in virus-infected cells. mRNAs synthesized both in vitro and in virus-infected cells were translated in vitro. NP, P, M and V proteins synthesized in vitro comigrated, when analyzed by SDS-PAGE, with the authentic proteins synthesized in virus-infected cells. Additionally, peptide mapping showed that the NP, P and M proteins synthesized in vitro were indistinguishable from their counterparts synthesized in infected cells. Analysis of the proteins from virions identified L, HN, NP, F (F1, F2), P, M and V proteins as virion structural proteins. Electrophoretic mobility of reduced and nonreduced F proteins was found to be different due to the conformational changes conferred by disulfide bonds.

Cell Line↗

Whole-genome evolutionary dynamics of human parainfluenza virus type 3 in Shanghai, China, 2016-2024.

• Fifty whole-genome sequencing revealed co-circulating HPIV-3 C3 sub-lineages C3f and C3a in Shanghai, China. • Whole-genome phylogeny dated the HPIV-3 tMRCA to ∼1925.6 and revealed two post-1990 demographic expansions. • Recombination signals detected in the HN gene and other regions may lead to discordance in partial-gene phylogenies. • The L gene showed the highest variability and harbored the largest number of putative positively selected sites.

Letter↗

Respiratory viral infections in immunocompetent and immunocompromised persons.

The acute respiratory illnesses are the most common type of acute illness in the United States today. The respiratory viruses--which include influenza viruses, parainfluenza viruses, respiratory syncytial virus (RSV), rhinoviruses, coronaviruses, and adenoviruses--cause the majority of these illnesses. Some of these viruses cause illness throughout the year, whereas others are most common in winter. All population groups experience these infections and illnesses. As the number of elderly persons and those with underlying disease increases, awareness is growing that these common infections can have serious consequences. This has recently been emphasized for immunocompromised persons. At the M.D. Anderson Cancer Center (MDACC), infection surveillance of mostly hospitalized adults with leukemia or a recent bone marrow transplant yielded a respiratory virus from 181 of 668 (27.1%) respiratory illness episodes. In descending order of frequency, infections with RSV, rhinoviruses, influenza viruses, parainfluenza viruses, and adenoviruses were detected in each of three surveillance years. High frequencies of nosocomial acquisition occurred, as has been noted in prior reports. Similarly, persistence of infection and high frequencies of pneumonia and death among infected patients occurred, which have also been noted earlier. At MDACC, pneumonia occurred in 58-78% of infected patients, and 22-44% died. The role of the virus infection in many cases of pneumonia is uncertain, but death from pure viral pneumonia is well documented. A number of immune deficiencies in this patient population and options for control of these infections have been described that can, respectively, account for the medical problem and provide ways to approach prevention and treatment.

Bone Marrow Transplantation↗