No magic bullet: Limiting in-school transmission in the face of variable SARS-CoV-2 viral loads.

In the face of a long-running pandemic, understanding the drivers of ongoing SARS-CoV-2 transmission is crucial for the rational management of COVID-19 disease burden. Keeping schools open has emerged as a vital societal imperative during the pandemic, but in-school transmission of SARS-CoV-2 can contribute to further prolonging the pandemic. In this context, the role of schools in driving SARS-CoV-2 transmission acquires critical importance. Here we model in-school transmission from first principles to investigate the effectiveness of layered mitigation strategies on limiting in-school spread. We examined the effect of masks and air quality (ventilation, filtration and ionizers) on steady-state viral load in classrooms, as well as on the number of particles inhaled by an uninfected person. The effectiveness of these measures in limiting viral transmission was assessed for variants with different levels of mean viral load (ancestral, Delta, Omicron). Our results suggest that a layered mitigation strategy can be used effectively to limit in-school transmission, with certain limitations. First, poorly designed strategies (insufficient ventilation, no masks, staying open under high levels of community transmission) will permit in-school spread even if some level of mitigation is present. Second, for viral variants that are sufficiently contagious, it may be difficult to construct any set of interventions capable of blocking transmission once an infected individual is present, underscoring the importance of other measures. Our findings provide practical recommendations; in particular, the use of a layered mitigation strategy that is designed to limit transmission, with other measures such as frequent surveillance testing and smaller class sizes (such as by offering remote schooling options to those who prefer it) as needed.

LEOPARD Syndrome.

LEOPARD syndrome (LS) is an autosomal dominantly inherited or sporadic disorder of variable penetrance and expressivity. The acronym LEOPARD stands for its cardinal clinical features including Lentigines, Electrocardiographic conduction abnormalities, Ocular hypertelorism, Pulmonary stenosis, Abnormalities of genitalia, Retardation of growth, and Deafness. We present herein a patient with LEOPARD syndrome and distinctive features. It was noteworthy that our patient presented with the concern of generalized lentiginosis and subsequent evaluation revealed that the patient had LEOPARD syndrome. In this report we would like to highlight the importance of detailed clinical examination and appropriate imaging in patients with multiple lentigines.

Effect of ethanol extract of Piper betle Linn leaf on healing of NSAID-induced experimental ulcer--a novel role of free radical scavenging action.

Treatment with ethanol extract of leaf of P. betle at a dose of 150 mg/kg body weight daily for 10 days, after induction of peptic ulcer by NSAID in albino rats, produced significant healing effect. During healing process, on treatment with the extractive, antioxidative factor, e.g. superoxide dismutase and catalase activity, mucus and total gastric tissue sulfhydryl group were increased. In contrast, oxidised lipid and oxidatively modified proteins were reduced to near normalcy, within 7 to 10 days, however, change in the untreated group was not significant. The extract also showed significant in vitro free radical scavenging action. The results suggest that the antioxidant or free radical scavenging activity of the plant extract, may be responsible for its healing action.

Potent antiulcerogenic activity of ethanol extract of leaf ofPiper betle Linn by antioxidative mechanism.

Pretreatment of an ethanolic extract of leaf ofPiper betle linn at a dose of 200mg/kg body weight, orally administered to rats for ten consecutive days, was found to possess a significant protective action against gastric lesions induced by indomethacin. The extract pretreatment resulted in significant increase in superoxide dismutase (SOD) and catalase (CAT) activity, increase in mucus, hexosamine and total thiol group content, but marked reduction in oxidatively damaged protein and peroxidised lipid levels as compared to untreated ulcerated control. The extract was also found to possess both superoxide and hydroxyl free radical scavenging action. The present observations establish the efficacy of the extract in prevention of experimentally induced peptic ulcer by indomethacin and antioxidant property appears to be predominantly responsible for such cytoprotective activity in the experimental model.

Antioxidant activity of ethanol extract of rhizome ofPicrorhiza kurroa on indomethacin induced gastric ulcer during healing.

Oral administration of ethanol extract of the rhizome ofPirorhiza kurroa at a dose of 20mg/kg body weight, for 10 consecutive days, was found to enhance the rate of healing on Indomethacin-induced gastric ulcer in rats, compared to the ulcerated group without treatment. The level of peroxidised lipid, in terms of thiobarbituric acid reactive species (TBARS), in gastric tissue, was increased in ulcerated rats which was restored to near normalcy on treatment with ethanol extract. The specific activity ofin vivo antioxidant enzymes, viz SOD and catalase and total tissue sulfhydryl (thiol) group, which were markedly decreased in ulcerated group, were found to be significantly elevated (p<0.05), on treatment with the above extract, at the specified dose, compared to the indomethacin-induced ulcerated group without any supporting treatment. The present study thus suggests that the ethanol extract of rhizome ofPicrorhiza kurroa, at the dose of 20mg/kg body weight, accelerated the healing of stomach wall of indomethacin induced gastric ulcerated rats by anin vivo free radical scavenging action.