Studies on growth and steroid formation in tissue cultures of Holarrhena antidysenterica

Callus cultures derived from the hypocotyl of germinated seedlings of the plant, Holarrhena antidysenterica showed an inherent lack of organ-forming ability when grown under the influence of a wide range of exogenous growth factors. Several sterols were isolated from the callus, of which, the predominant ones were identified as cholesterol, 24-methylenecholesterol, 28-isofucosterol, sitosterol and stigmasterol.     

Microbial deracemisation of aromatic β-hydroxy acid esters

Aromatic β-hydroxy acid esters were found to undergo deracemisation using whole cells of Candida parapsilosis. The conditions for the deracemisation reaction were optimised where 75% isolated yield and >95% enantiomeric excess of the product was achieved. The effect of electron donating as well as electron withdrawing groups present in the standard substrate, ethyl 3-hydroxy 3-phenyl propionate was studied to establish the generality of the reaction. The enantiomeric excess of the product remains high (>95%) irrespective of the different substituents in the para position but substitution at the ortho position obstructs the process. Similarly, ethyl and methyl esters of the standard substrate undergo deracemisation reaction giving high ee of the product, but the benzyl ester of the standard substrate did not undergo deracemisation.     

Molecular size heterogeneity of human leukocyte interferon

Molecular sieving of human leukocyte interferon revealed an apparent molecular weight of 26,000. However, after denaturation by guanidine hydrochloride in the presence of a reducing agent and reactivation by extensive dialysis, a molecular weight of only 21,000 was observed. The reactivated human leukocyte interferon (mol wt 21,000) gave a single peak of activity when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, confirming that a single molecular weight species was generated by the denaturation and reactivation procedure. A partial unfolding of the molecule was evident when the interferon preparation was heated to 50 degrees C in the absence or presence of an unfolding agent and then sieved on Sephadex G-100 Superfine. These results suggest that the interferon molecule undergoes a proteolytic cleavage probably by a protease present in extracellular fluid. Thus, a peptide fragment dissociates from the parent molecule when human leukocyte interferon is denatured in the presence of a reducing agent, resulting in a drop of 5,000 in molecular weight; interestingly, the resultant 21,000 molecular weight form still retains its antiviral activity.     

Efficacy of live attenuated and inactivated influenza vaccines among children in rural India: A 2-year,randomized, triple-blind,placebo-controlled trial

BackgroundInfluenza is a cause of febrile acute respiratory infection (FARI) in India; however, few influenza vaccine trials have been conducted in India. We assessed absolute and relative efficacy of live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV) among children aged 2 to 10 years in rural India through a randomized, triple-blind, placebo-controlled trial conducted over 2 years.Methods and findingsIn June 2015, children were randomly allocated to LAIV, IIV, intranasal placebo, or inactivated polio vaccine (IPV) in a 2:2:1:1 ratio. In June 2016, vaccination was repeated per original allocation. Overall, 3,041 children received LAIV (n = 1,015), IIV (n = 1,010), nasal placebo (n = 507), or IPV (n = 509). Mean age of children was 6.5 years with 20% aged 9 to 10 years.Through weekly home visits, nasal and throat swabs were collected from children with FARI and tested for influenza virus by polymerase chain reaction. The primary outcome was laboratory-confirmed influenza-associated FARI; vaccine efficacy (VE) was calculated using modified intention-to-treat (mITT) analysis by Cox proportional hazards model (PH) for each year.In Year 1, VE was 40.0% (95% confidence interval (CI) 25.2 to 51.9) for LAIV and 59.0% (95% CI 47.8 to 67.9) for IIV compared with controls; relative efficacy of LAIV compared with IIV was −46.2% (95% CI −88.9 to −13.1). In Year 2, VE was 51.9% (95% CI 42.0 to 60.1) for LAIV and 49.9% (95% CI 39.2 to 58.7) for IIV; relative efficacy of LAIV compared with IIV was 4.2% (95% CI −19.9 to 23.5). No serious adverse vaccine-attributable events were reported. Study limitations include differing dosage requirements for children between nasal and injectable vaccines (single dose of LAIV versus 2 doses of IIV) in Year 1 and the fact that immunogenicity studies were not conducted.ConclusionsIn this study, we found that LAIV and IIV vaccines were safe and moderately efficacious against influenza virus infection among Indian children.Trial registrationClinical Trials Registry of India CTRI/2015/06/005902.

Anand Krishnan and co-workers study the efficacy and safety of influenza vaccines for children in India.