Investigating the relationship of schools reopening to increases in COVID-19 infections using event study methodology: The case of the Delta variant.

BACKGROUND: Hypothesis: School reopening had a significant impact on COVID-19 infection rates across USA states. METHODS: Eight states with fully reopened public schools were studied. States who did not previously have stay-at-home orders for a minimum of 30 days were excluded from the study so that increases in infection rates would be solely due to the economies of reopening. This study used event study methodology with a 30-day estimation window. This allowed us to determine if increases in COVID-19 infection rates were significant following schools reopening. RESULTS: Eight states were analyzed, and seven of the states had positive and significant COVID-19 infection increases. The other state's increase was negative and significant. CONCLUSIONS: This study found that reopening of schools had an initial 5-day increase in COVID-19 infections in seven of eight states whose data were examined. With schools being re-opened nationwide in Fall 2021, this indicates that with the Delta variant there is an expected significant increase in infections.

Relationship of George Floyd protests to increases in COVID-19 cases using event study methodology.

BACKGROUND: Protests ignited by the George Floyd incident were examined for any significant impact on COVID-19 infection rates in select US cities. METHODS: Eight US cities were studied in which protestors in the tens of thousands were reported. Only cities that reside in states whose stay-at-home orders had been rescinded or expired for a minimum of 30 days were included in the sample to account for impact of growth rates solely due to economies reopening. Event study methodology was used with a 30-day estimation period to examine whether growth in COVID-19 infection rates was significant. RESULTS: In the eight cities analyzed, all had positive abnormal growth in infection rate. In six of the eight cities, infection rate growth was positive and significant. CONCLUSIONS: In this study, it was apparent that violations of Centers for Disease Control and Prevention (CDC)-recommended social distancing guidelines caused a significant increase in infection rates. The data suggest that to slow the spread of COVID-19, CDC guidelines must be followed in protest situations.

Structure-activity relationship between carboxylic acids and T cell cycle blockade.

This study was designed to examine the potential structure-activity relationship between carboxylic acids, histone acetylation and T cell cycle blockade. Toward this goal a series of structural homologues of the short-chain carboxylic acid n-butyrate were studied for their ability to block the IL-2-stimulated proliferation of cloned CD4+ T cells. The carboxylic acids were also tested for their ability to inhibit histone deacetylation. In addition, Western blotting was used to examine the relative capacity of the carboxlic acids to upregulate the cyclin kinase-dependent inhibitor p21cip1 in T cells. As shown earlier n-butyrate effectively inhibited histone deacetylation. The increased acetylation induced by n-butyrate was associated with the upregulation of the cyclin-dependent kinase inhibitor p21cip1 and the cell cycle blockade of CD4+ T cells. Of the other carboxylic acids studied, the short chain acids, C3-C5, without branching were the best inhibitors of histone deacetylase. This inhibition correlated with increased expression of the cell cycle blocker p21cip1, and the associated suppression of CD4+ T cell proliferation. The branched-chain carboxylic acids tested were ineffective in all the assays. These results underline the relationship between the ability of a carboxylic acid to inhibit histone deacetylation, and their ability to block T cell proliferation, and suggests that branching inhibits these effects.

Anti-anaphylactic action of nordihydroguaiaretic acid in antigen sensitized guinea pigs.

Therapeutic natural products and medicinal herbs has gained popularity. The anti-antigenic action of the plant alkaloid nordihydroguaiaretic acid (NDGA) was studied in ovalbumin (OA)-sensitized guinea pigs. In one series of experiments conscious, non-sedated guinea pigs were challenged with OA aerosol. Specific airway resistance (SRAW) was monitored using a two-chambered whole-body plethysmograph. OA aerosol increased SRAW above that produced by vehicle administration. Prior NDGA administration by a 1min 0.9% aerosol (w/vol) attenuated the increase in SRAW resulting from OA challenge. In the anesthetized guinea pig pretreated with indomethacin, pyrilamine and propranolol, intravenous OA injection increased intra-tracheal pressure above vehicle injection. Intravenous NDGA administration (5mg/kg) reduced the intra-tracheal pressure increases. In a third series of experiments plasma leukotriene C4 was measured by radio-immunoassay in 3 groups challenged with OA aerosol: vehicle-treated OA-sensitized, OA-sensitized receiving NDGA and vehicle treated guinea pigs. NDGA pretreatment reduced plasma LTC4 in response to OA challenge in OA sensitized guinea pigs. This study demonstrates that NDGA is an effective antigenic agent when given by aerosol or intravenous injection in either conscious or anesthetized guinea pigs, respectively. The mechanism of action of NDGA is presumed primarily be due to the blockage of 5-lipoxygenase and therefore the synthesis of leukotrienes.

Drug testing for newborn exposure to illicit substances in pregnancy: pitfalls and pearls.

Estimates of the prevalence of drug usage during pregnancy vary by region and survey tool used. Clinicians providing care to newborns should be equipped to recognize a newborn who has been exposed to illicit drugs during pregnancy by the effects the exposure might cause at the time of delivery and/or by drug testing of the newborn. The purpose of this paper is to provide an overview of the literature and assess the clinical role of drug testing in the newborn. Accurate recognition of a newborn whose mother has used illicit drugs in pregnancy cannot only impact decisions for healthcare in the nursery around the time of delivery, but can also provide a key opportunity to assess the mother for needed services. While drug use in pregnancy is not an independent predictor of the mother's ability to provide a safe and nurturing environment for her newborn, other issues that often cooccur in the life of a mother with a substance abuse disorder raise concerns for the safety of the discharge environment and should be assessed. Healthcare providers in these roles should advocate for unbiased and effective treatment services for affected families.