Osmotic diuresis-induced hypernatremia: better explained by solute-free water clearance or electrolyte-free water clearance?

Hypernatremia may result from inadequate water intake, excessive water loss or a combination of the two. Osmotic diuresis leads to losses of both solute and water. The relationship between solute and water losses determines the resulting changes in serum osmolality and sodium concentration. Total solute loss is routinely higher than loss of water in osmotic diuresis. Theoretically, then, decreases in serum osmolality (and serum sodium concentration) should follow. In clinical situations of osmotic diuresis, however, reduction in osmolality can take place, but not reduction in serum sodium concentration. It is of note that serum sodium concentration changes are related to urinary losses of sodium and potassium but not to the loss of total solute. In osmotic diuresis, the combined loss of sodium and potassium per liter of urine is lower than the concurrent serum sodium level. Consequently, hypernatremia can ensue. A patient who presented with osmotic diuresis and hypernatremia is described here. In this patient, we have shown that electrolyte-free water clearance is a better index of the effect of osmotic diuresis on serum sodium concentration than the classic solute-free water clearance.     

Structure-Function Analyses of New SARS-CoV-2 Variants B.1.1.7, B.1.351 and B.1.1.28.1: Clinical,Diagnostic, Therapeutic and Public Health Implications

SARS-CoV-2 (Severe Acute Respiratory Syndrome-Coronavirus 2) has accumulated multiple mutations during its global circulation. Recently, three SARS-CoV-2 lineages, B.1.1.7 (501Y.V1), B.1.351 (501Y.V2) and B.1.1.28.1 (P.1), have emerged in the United Kingdom, South Africa and Brazil, respectively. Here, we have presented global viewpoint on implications of emerging SARS-CoV-2 variants based on structural–function impact of crucial mutations occurring in its spike (S), ORF8 and nucleocapsid (N) proteins. While the N501Y mutation was observed in all three lineages, the 501Y.V1 and P.1 accumulated a different set of mutations in the S protein. The missense mutational effects were predicted through a COVID-19 dedicated resource followed by atomistic molecular dynamics simulations. Current findings indicate that some mutations in the S protein might lead to higher affinity with host receptors and resistance against antibodies, but not all are due to different antibody binding (epitope) regions. Mutations may, however, result in diagnostic tests failures and possible interference with binding of newly identified anti-viral candidates against SARS-CoV-2, likely necessitating roll out of recurring “flu-like shots” annually for tackling COVID-19. The functional relevance of these mutations has been described in terms of modulation of host tropism, antibody resistance, diagnostic sensitivity and therapeutic candidates. Besides global economic losses, post-vaccine reinfections with emerging variants can have significant clinical, therapeutic and public health impacts.     

Technical,scale, and size efficiency in nursing home care: A nonparametric analysis of Connecticut homes

Maindiratta (1990) questioned the usefulness of the concept of scale efficiency in production as the most productive scale size (MPSS) usually requires altering the scale of output produced. If the decision making unit (DMU) is required to deliver a specific output bundle, then altering output along with the input scale to reach the MPSS is not a valid recommendation. He proposed a measure of the size efficiency of a DMU. In this paper, we apply Data Envelopment Analysis (DEA) to examine the levels of technical, scale, and size efficiency of individual nursing homes providing health care to the elderly. The data used relate to the operations of 140 nursing homes from Connecticut, USA during the year 1982–83. Maindiratta's model is input-oriented. By contrast, our study is output-oriented and we appropriately reformulate Maindiratta's model. The findings show that in several cases size efficiency is less than unity. This suggests that the most efficient production of output would require restructuring of the nursing home under investigation as more than one small unit. We also compare the efficiency levels of ‘for-profit’ homes with those of ‘not-for-profit’ homes.     

Collateral damage: Corneal injury due to mask use during the COVID-19 pandemic - A case series

Though masks are the best shield against COVID-19, they can be a source of discomfort and ocular side effects. We discuss three cases of corneal injury due to mask use. Three patients, who were healthcare workers, presented with discomfort, photophobia, and pain in the eyes. While adjusting the mask, they had an ocular injury. There were multiple superficial linear abrasions in the eyes. They recovered with treatment. Though masks are imperative during the COVID-19 pandemic, it is important to be aware of a possible mask injury.     

Flow cytometry antifungal susceptibility testing of Aspergillus fumigatus and comparison of mode of action of voriconazole vis-à-vis amphotericin B and itraconazole

Aspergillus fumigatus isolates were tested with three antifungals by flow cytometry (FC) and fluorescence-activated cell sorting. FC results after 4 h correlated well with MICs obtained by the NCCLS M38-A method; voriconazole exhibited fungicidal activity, albeit to a lesser extent than amphotericin B, but to a greater extent than itraconazole.