DDRE-49. TRANSIENT OPENING OF THE BLOOD-BRAIN BARRIER BY VASOACTIVE PEPTIDES TO INCREASE CNS DRUG DELIVERY: REALITY VERSUS WISHFUL THINKING?

BACKGROUND

Drug delivery to treat neurologic disease and cancers of the central nervous system (CNS) is severely limited by the blood-brain barrier (BBB). Vasoactive peptides (VAPs) such as regadenoson, adenosine, and labradimil have been shown in animal studies to transiently open the BBB, and regadenoson is currently under investigation in humans to determine if it might improve CNS drug delivery. There is currently limited information regarding the potential for other VAPs to open the BBB transiently.

METHODS

We performed a review of the literature evaluating the physiologic effects of vasoactive peptides on the vasculature of the brain and systemic organs. To assess the likelihood that a vasoactive peptide might transiently disrupt the BBB, we devised a four-tier classification system to organize data available in the literature which factors in alterations in BBB integrity and effects on normal brain vasculature and systemic blood vessels. This data was further sorted based on whether it comes from humans, animals, or in vitro systems.

RESULTS

We identified 38 VAPs with potential BBB permeability-altering properties. To date, none of these has been shown to open the BBB in humans. Thirteen VAPs increased BBB permeability in rodents. The remaining 25 had favorable physiologic effects on blood vessels but lack specific information on permeability changes to the BBB. We ranked VAPs in a four-tier ranking system related to their known physiologic actions.

CONCLUSION

Rodent studies document that analogs of bradykinin and adenosine transiently disrupt the BBB leading to higher chemotherapy concentrations in the CNS. VAPs remain an understudied class of drugs with the potential to increase drug delivery to the CNS. Dozens of VAPs have yet to be formally evaluated for this important clinical effect. This retrospective review summarizes the available data on VAPs highlighting agents that deserve further in vitro and in vivo investigations.

Firearm homicide mortality is influenced by structural racism in US metropolitan areas

INTRODUCTION

Metropolitan cities in the United States suffer from higher rates of gun violence. However, the specific structural factors associated with increased gun violence are poorly defined. We hypothesized that firearm homicide in metropolitan cities would be impacted by Black-White segregation index.

METHODS

This cross-sectional analysis evaluated 51 US metropolitan statistical areas (MSAs) using data from 2013 to 2017. Several measures of structural racism were examined, including the Brooking Institute's Black-White segregation index. Demographic data were derived from the US Census Bureau, US Department of Education, and US Department of Labor. Crime data and firearm homicide mortality rates were obtained from the Federal Bureau of Investigation and the Centers for Disease Control. Spearman ρ and linear regression were performed.

RESULTS

Firearm mortality was associated with multiple measures of structural racism and racial disparity, including White-Black segregation index, unemployment rate, poverty rate, single parent household, percent Black population, and crime rates. In regression analysis, percentage Black population exhibited the strongest association with firearm homicide mortality (β = 0.42, p < 0.001). Black-White segregation index (β = 0.41, p = 0.001) and percent children living in single-parent households (β = 0.41, p = 0.002) were also associated with higher firearm homicide mortality. Firearm legislation scores were associated with lower firearm homicide mortality (β = -0.20 p = 0.02). High school and college graduation rates were not associated with firearm homicide mortality and were not included in the final model.

CONCLUSION

Firearm homicide disproportionately impacts communities of color and is associated with measures of structural racism, such as White-Black segregation index. Public health interventions targeting gun violence must address these systemic inequities. Furthermore, given the association between firearm mortality and single-parent households, intervention programs for at-risk youth may be particularly effective.

LEVEL OF EVIDENCE

Epidemiological level II.

Asthma in COVID-19 patients: An extra chain fitting around the neck?

Introduction

The novel coronavirus disease 2019 (COVID-19) has rapidly spread across the globe. Pre-existing comorbidities have been found to have a dramatic effect on the disease course. We sought to analyze the effect of asthma on the disease progression and outcomes of COVID-19 patients.

Methods

We conducted a multi-center retrospective study of positively confirmed COVID-19 patients. The primary outcome of interest was in-hospital mortality. Secondary outcomes were the Intensive Care Unit (ICU) admission, intubation, mechanical ventilation, and length of hospital stay.

Results

A total of 502 COVID-19 adult patients (72 asthma and 430 non-asthma cohorts) with mean age of 60.7 years were included in the study. The frequency of asthma in hospitalized cohorts was 14.3%. Univariate analysis revealed that asthma patients were more likely to be obese (75% versus 54.2%, p = 0.001), with a higher frequency of intubation (40.3% versus 27.8%, p = 0.036), and required a longer duration of hospitalization (15.1 ± 12.5 versus 11.5 ± 10.6, p = 0.015). After adjustment, multivariable analysis showed that asthmatic patients were not associated with higher risk of ICU admission (OR = 1.81, 95%CI = 0.98–3.09, p = 0.06), endotracheal intubation (OR = 1.77, 95%CI = 0.99–3.04, p = 0.06) or complications (OR = 1.37, 95%CI = 0.82–2.31, p = 0.23). Asthmatic patients were not associated with higher odds of prolonged hospital length of stay (OR = 1.48, 95%CI = 0.82–2.66, p = 0.20) or with ICU stay (OR = 0.76, 95%CI = 0.28–2.02, p = 0.58). Kaplan-Meier curve showed no significant difference in the overall survival of the two groups (p = 0.65).

Conclusion

Despite the increased prevalence of hospitalization in elder asthmatic COVID-19 patients, after adjustment for other variables, it was neither associated with increased severity nor worse outcomes.

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Asthma is more prevalent in COVID-19 cohort than in the general population.

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Asthma was neither associated with disease severity nor negative outcomes.

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Asthma does not imply a worse outcome as compared to non-asthmatics.

Sex Ratio Manipulation and Selection for Attractiveness

Laboratory experiments performed on a monogamous estrildid, the zebra finch (Poephila guttata), indicate that sex ratio of offspring is affected by non-genetic markers (colored plastic leg bands) that vary in attractiveness to birds. Results suggest that natural selection favors individuals that produce offspring of the sex of the more attractive parent within a breeding pair.

Parental investment, mate choice, and mate quality

Current theory in sexual selection is extended to predict within-sex variability with regard to selectivity towards mates in different mating systems. Generally, the sex that invests more in the care of each offspring should be more selective of mates than the sex investing less. Within each sex, individuals of low male quality should be less selective than individuals of high quality, but there should be less variation in selectivity among individuals of the sex investing more. When only one sex contributes parental care, however, individuals of that sex should be uniformly selective, while the other sex is expected to mate indiscriminately. Using feral pigeons (Columba livia), these hypotheses are tested for the case in which both sexes contribute substantial parental care, but in which females contribute more than males. As predicted, females were found to be more selective of mates than males were. On certain criteria, males of lower quality were less selective of mates than males of higher quality.