A Prospective Study of Recovery of Salivary Gland Function After Calculus Removal by Sialendoscopy.

Sialendoscopy is gaining popularity in treating obstructive sialolithiasis as a gland preserving procedure. The study aimed to determine if the salivary glands recovered apart from symptomatic improvement after interventional sialendoscopy for calculus removal. A prospective comparative study was conducted in a tertiary care center on 24 patients diagnosed with sialolithiasis. The eligibility criterion was patients who underwent calculus removal through interventional sialendoscopy. All patients underwent objective and subjective methods of assessments of function of the salivary glands with the help of salivary Technetium (Tc) 99 Scintigraphy, measurement of salivary flow rate, Chronic obstructive sialadenitis symptoms (COSS), and xerostomia index (XI) questionnaires. Assessments were done before the procedure and repeated after 3 months. Categorical variables were expressed using frequency and percentage. Numerical variables were represented using mean and standard deviation. To test the statistical significance of the difference in the mean of the four parameters Wilcoxen sign ranked test was used. According to our study improvement in functionality was noted in all of the subjective and objective parameters assessed namely Tc scintigraphy, salivary flow rate, COSS questionnaire, and XI questionnaire, with a statistically significant p value (< 0.001). Functionality of salivary gland showed improvement within 3 months of calculus removal through sialendoscopy. There was a marked improvement in the symptoms after sialendoscopy. This study demonstrates that removal of obstructing calculus results in rapid recovery of glandular function thereby emphasizing the need for salivary gland preservation. Level of evidence: Level III.

Microbial engineering for the production and application of phytases to the treatment of the toxic pollutants: A review.

Phytases are a group of digestive enzymes which are commonly used as feed enzymes. These enzymes are used exogenously in the feeds of monogastric animals thereby it improves the digestibility of phosphorous and thus reduces the negative impact of inorganic P excretion on the environment. Even though these enzymes are widely distributed in many life forms, microorganisms are the most preferred and potential source of phytase. Despite the extensive availability of the phytase-producing microbial consortia, only a few microorganisms have been known to be exploited at industrial level. The high costs of the enzyme along with the incapability to survive high temperatures followed by the poor storage stability are noted to be the bottleneck in the commercialization of enzymes. For this reason, besides the conventional fermentation approaches, the applicability of cloning, expression studies and genetic engineering has been implemented for the past few years to accomplish the abovesaid benefits. The site-directed mutagenesis as well as knocking out have also validated their prominent role in microbe-based phytase production with enhanced levels. The present review provides detailed information on recent insights on the modification of phytases through heterologous expression and protein engineering to make thermostable and protease-resistant phytases.

Microbial engineering for the production of isobutanol: current status and future directions.

Fermentation-derived alcohols have gained much attention as an alternate fuel due to its minimal effects on atmosphere. Besides its application as biofuel it is also used as raw material for coating resins, deicing fluid, additives in polishes, etc. Among the liquid alcohol type of fuels, isobutanol has more advantage than ethanol. Isobutanol production is reported in native yeast strains, but the production titer is very low which is about 200 mg/L. In order to improve the production, several genetic and metabolic engineering approaches have been carried out. Genetically engineered organism has been reported to produce maximum of 50 g/L of isobutanol which is far more than the native strain without any modification. In bacteria mostly last two steps in Ehrlich pathway, catalyzed by enzymes ketoisovalerate decarboxylase and alcohol dehydrogenase, are heterologously expressed to improve the production. Native Saccharomyces cerevisiae can produce isobutanol in negligible amount since it possesses the pathway for its production through valine degradation pathway. Further modifications in the existing pathways made the improvement in isobutanol production in many microbial strains. Fermentation using cost-effective lignocellulosic biomass and an efficient downstream process can yield isobutanol in environment friendly and sustainable manner. The present review describes the various genetic and metabolic engineering practices adopted to improve the isobutanol production in microbial strains and its downstream processing.

Predicting COVID-19 Vaccine Efficacy from Neutralizing Antibody Levels

Recent studies using data accrued from global SARS-CoV-2 vaccination efforts have demonstrated that breakthrough infections are correlated with levels of neutralizing antibodies. The decrease in neutralizing antibody titers of vaccinated individuals over time, combined with the emergence of more infectious variants of concern has resulted in waning vaccine efficacy against infection and a rise in breakthrough infections. Here we use a combination of neutralizing antibody measurements determined by a high throughput surrogate viral neutralization test (sVNT) together with published data from vaccine clinical trials and comparative plaque reduction neutralization test (PRNT) between SARS-CoV-2 variants to develop a model for vaccine efficacy (VE) against symptomatic infection. Vaccine efficacy estimates using this model show good concordance with real world data from the US and Israel. Our work demonstrates that appropriately calibrated neutralizing antibody measurements determined by high throughput sVNT can be used to provide a semi-quantitative estimate of protection against infection. Given the highly variable antibody levels among the vaccinated population, this model may be of use in identification of individuals with an elevated risk of breakthrough infections.