The value of decreasing the duration of the infectious period of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection

Finding medications or vaccines that may decrease the infectious period of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could potentially reduce transmission in the broader population. We developed a computational model of the U.S. simulating the spread of SARS-CoV-2 and the potential clinical and economic impact of reducing the infectious period duration. Simulation experiments found that reducing the average infectious period duration could avert a median of 442,852 [treating 25% of symptomatic cases, reducing by 0.5 days, reproductive number (R₀) 3.5, and starting treatment when 15% of the population has been exposed] to 44.4 million SARS-CoV-2 cases (treating 75% of all infected cases, reducing by 3.5 days, R₀ 2.0). With R₀ 2.5, reducing the average infectious period duration by 0.5 days for 25% of symptomatic cases averted 1.4 million cases and 99,398 hospitalizations; increasing to 75% of symptomatic cases averted 2.8 million cases. At $500/person, treating 25% of symptomatic cases saved $209.5 billion (societal perspective). Further reducing the average infectious period duration by 3.5 days averted 7.4 million cases (treating 25% of symptomatic cases). Expanding treatment to 75% of all infected cases, including asymptomatic infections (R₀ 2.5), averted 35.9 million cases and 4 million hospitalizations, saving $48.8 billion (societal perspective and starting treatment after 5% of the population has been exposed). Our study quantifies the potential effects of reducing the SARS-CoV-2 infectious period duration.     

A High-Content Small Molecule Screen Identifies Sensitivity of Glioblastoma Stem Cells to Inhibition of Polo-Like Kinase 1

Glioblastoma multiforme (GBM) is the most common primary brain cancer in adults and there are few effective treatments. GBMs contain cells with molecular and cellular characteristics of neural stem cells that drive tumour growth. Here we compare responses of human glioblastoma-derived neural stem (GNS) cells and genetically normal neural stem (NS) cells to a panel of 160 small molecule kinase inhibitors. We used live-cell imaging and high content image analysis tools and identified JNJ-10198409 (J101) as an agent that induces mitotic arrest at prometaphase in GNS cells but not NS cells. Antibody microarrays and kinase profiling suggested that J101 responses are triggered by suppression of the active phosphorylated form of polo-like kinase 1 (Plk1) (phospho T210), with resultant spindle defects and arrest at prometaphase. We found that potent and specific Plk1 inhibitors already in clinical development (BI 2536, BI 6727 and GSK 461364) phenocopied J101 and were selective against GNS cells. Using a porcine brain endothelial cell blood-brain barrier model we also observed that these compounds exhibited greater blood-brain barrier permeability in vitro than J101. Our analysis of mouse mutant NS cells (INK4a/ARF^−/−, or p53^−/−), as well as the acute genetic deletion of p53 from a conditional p53 floxed NS cell line, suggests that the sensitivity of GNS cells to BI 2536 or J101 may be explained by the lack of a p53-mediated compensatory pathway. Together these data indicate that GBM stem cells are acutely susceptible to proliferative disruption by Plk1 inhibitors and that such agents may have immediate therapeutic value.     

Long-term effects of dietary isoflavones on uterine gene expression profiles

Isoflavones (ISOs) are bioactive food ingredients of the traditional East Asian diet and currently discussed as alternatives to classical hormone replacement therapies and for reducing the prevalence of hormone-dependent cancers. Although there are many studies on ISOs, not much is known about their long-term effects.Therefore, we performed an animal experiment analyzing the effects of three different diets: a phytoestrogen-free diet, a diet supplemented with genistein (700 μg/g diet) and an ISO-high diet (232 μg daidzein and 240 μg genistein/g) at two distinct time points, juvenile (21 days) and adult (97 days). Exposure started prior to mating of the parents and throughout the life of the offspring.We observed a stronger increase of uterine wet weights in juvenile offspring with genistein exposure (1018 ± 350 mg/kg BW) than with ISO-high diet (497 ± 133 mg/kg BW). Whereas the expression of proliferation related genes (PCNA; Ki67; IGF-1; IGF-1R), analyzed by real-time-qPCR and Western blot, were significantly down-regulated in juvenile animals exposed to genistein. Additionally, genistein exposure led to estrogenic responses, observed upon increase of complement C3 and decrease of estrogen receptors gene expressions, while the exposure to ISO-high diet did not show these effects.In conclusion, both the time point on which phytoestrogen exposure starts together with the composition of the ingested phytoestrogen containing diet are of great importance for the biological response of the offspring.     

Cyclic GMP-dependent and cyclic AMP-dependent protein kinases,protein kinase modulators and phosphodieterases in arteries and veins of dogs Distribution and effects of arteriovenous fistula and arterial occlusion

Possible involvement of cyclic GMP-dependent and cyclic AMP-dependent protein kinases, protein kinase modulators and cyclic nucleotide phosphodiesterases in functions of vascular tissues were investigated in the dog. All of the above activities, localized in the smooth muscle-rich inner layer of the blood vessels, were found to be higher in the arteries than in the veins. The peripheral arteries were disproportionately richer in cyclic GMP-dependent protein kinase (as indicated by high ratios of cyclic GMP-dependent to cyclic AMP-dependent protein kinase) than were the veins, with the exception of the pulmonary artery, an atypical arterial tissue exposed to low blood pressure. Interestingly, the protein kinase ratio for the aorta, an artery with no significant role in blood pressure regulation, was not higher than that for the vena cava. Creation of femoral arteriovenous fistulae in the dogs led to preferential reductions in the cyclic GMP-dependent enzyme activity both in the proximal and distal arteries, whereas it was elevated in the stressed vein distal to the anastomotic site. The cyclic GMP-dependent enzyme was preferentially reduced in the saphenous artery distal to occlusion. Changes in the cyclic GMP-dependent enzyme activity appeared to precede gross atrophy or hypertrophy of the vessels. It is suggested that the vascular cyclic GMP-dependent protein kinase may be closely related to peripheral resistance and its regulation.     

Hydrogenase activity in aged, nonviable Desulfovibrio vulgaris cultures and its significance in anaerobic biocorrosion

Batch cultures of Desulfovibrio vulgaris stored at 32 degrees C for 10 months have been found to retain 50% of the hydrogenase activity of a 1-day culture. The hydrogenase found in old cultures needs reducing conditions for its activation. Viable cell counts are negative after 6 months, showing that the hydrogenase activity does not depend on the presence of viable cells. These observations are of importance in the understanding of anaerobic biocorrosion of metals caused by depolarization phenomena.