Genetic variability in G2 and F2 region between biological clones of human respiratory syncytial virus with or without host immune selection pressure

Human respiratory syncytial virus (HRSV) is an important respiratory pathogens among children between zero-five years old. Host immunity and viral genetic variability are important factors that can make vaccine production difficult. In this work, differences between biological clones of HRSV were detected in clinical samples in the absence and presence of serum collected from children in the convalescent phase of the illness and from their biological mothers. Viral clones were selected by plaque assay in the absence and presence of serum and nucleotide sequences of the G2 and F2 genes of HRSV biological clones were compared. One non-synonymous mutation was found in the F gene (Ile5Asn) in one clone of an HRSV-B sample and one non-synonymous mutation was found in the G gene (Ser291Pro) in four clones of the same HRSV-B sample. Only one of these clones was obtained after treatment with the child's serum. In addition, some synonymous mutations were determined in two clones of the HRSV-A samples. In conclusion, it is possible that minor sequences could be selected by host antibodies contributing to the HRSV evolutionary process, hampering the development of an effective vaccine, since we verify the same codon alteration in absence and presence of human sera in individual clones of BR-85 sample.

simple and rapid HPLC-UV method for the determination of umckalin, as an herbal marker, in the cough syrup of pelargonium extract

A rapid and simple high performance liquid chromatography [HPLC] method with UV detection for the quantitation of umckalin, as an herbal marker, in Pelargonium extract cough syrup has been developed and validated. Chromatographic separation was achieved on a reverse phase Phenomenex-C[18] column [5 microm, 25 cm x 0.5 mm i.d.] using a mixture of acetonitrile and phosphoric acid [pH 2.5], in 25:75 [v/v] ratio, as a mobile phase at a flow rate of 1 mL/min under ambient conditions and with UV detection at 310 nm. The method, applied for umckalin quantitation, showed good linearity over the concentration range of 0.334 -1.667 microg/mL, with a correlation coefficient [r[2]] of 0.9996. The limit of detection [LOD] and limit of quantitation [LOQ] of umckalin were found to be 0.0344 and 0.1031 microg/mL, respectively. In addition, the developed HPLC method showed acceptable values of repeatability and intermediate precision and indicated high levels of method accuracy. Simplicity and validity of the method make it highly reliable and especially suitable for routine quality control analysis