The bounds of meta-analytics and an alternative method

OBJECTIVES

Meta-analysis is a statistical appraisal of the data analytic implications of published articles (Y), estimating parameters including the odds ratio and relative risk. This information is helpful for evaluating the significance of the findings. The Higgins I2 index is often used to measure heterogeneity among studies. The objectives of this article are to amend the Higgins I2 index score in a novel and innovative way and to make it more useful in practice.

METHODS

Heterogeneity among study populations can be affected by many sources, including the sample size and study design. They influence the Cochran Q score and, thus, the Higgins I2 score. In this regard, the I2 score is not an absolute indicator of heterogeneity. Q changes by bound as Y increases unboundedly. An innovative methodology is devised to show the conditional and unconditional probability structures.

RESULTS

Various properties are derived, including showing that a zero correlation between Q and Y does not necessarily mean that they are independent. A new alternative statistic, S2, is derived and applied to mild cognitive impairment and coronavirus disease 2019 vaccination for meta-analysis.

CONCLUSIONS

A hidden shortcoming of the Higgins I2 index is overcome in this article by amending the Higgins I2 score. The usefulness of the proposed methodology is illustrated using 2 examples. The findings have potential health policy implications.

Meta-analysis of primary care delivered buprenorphine treatment retention outcomes

Background: Currently, the capacity to provide buprenorphine treatment (BT) is not sufficient to treat the growing number of people in the United States with opioid use disorder (OUD). We sought to examine participant retention in care rates of primary care delivered BT programs and to describe factors associated with retention/attrition for participants receiving BT in this setting.Objectives: A PRISMA-guided search of various databases was performed to identify the articles focusing on efficacy of BT treatment and OUD.Method: A systematic literature search identified 15 studies examining retention in care in the primary care setting between 2002 and 2020. Random effects meta-regression were used to identify retention rates across studies.Results: Retention rates decreased across time with a mean 0.52 rate at one year. Several factors were found to be related to retention, including: race, use of other drugs, receipt of counseling, and previous treatment with buprenorphine.Conclusions: While we only investigate BT through primary care, our findings indicate retention rates are equivalent to the rates reported in the specialty care literature. More work is needed to examine factors that may impact primary care delivered BT specifically and differentiate participants that may benefit from care delivered in specialty over primary care as well as the converse.

COVID-19 Vaccine Hesitancy and Uptake among Minority Populations in Tennessee

COVID-19 vaccine hesitancy and uptake among Southern states in the US has been problematic throughout the pandemic. To characterize COVID-19 vaccine hesitancy and uptake among medically underserved communities in Tennessee. We surveyed 1482 individuals targeting minority communities in Tennessee from 2 October 2021 to 22 June 2022. Participants who indicated that they did not plan to receive or were unsure whether to receive the COVID-19 vaccine were considered vaccine-hesitant. Among participants, 79% had been vaccinated, with roughly 5.4% not likely at all to be vaccinated in the next three months from the date that the survey was conducted. When focusing particularly on Black/AA people and white people, our survey results revealed a significant association between race (Black/AA, white, or people of mixed Black/white ancestry) and vaccination status (vaccinated or unvaccinated) (p-value = 0.013). Approximately 79.1% of all participants received at least one dose of a COVID-19 vaccine. Individuals who were concerned with personal/family/community safety and/or wanted a return to normalcy were less likely to be hesitant. The study found that the major reasons cited for refusing the COVID-19 vaccines were distrust in vaccine safety, concerns about side effects, fear of needles, and vaccine efficacy.

SISTER (Sisters Inspiring Sisters to Engage in Relevant Diabetes Self-Care) Diabetes Study: Protocol for diabetes medical nutrition therapy randomized clinical trial among African American women

BACKGROUND

African American (AA) women with type 2 diabetes (T2D) carry disproportionate diabetes-related morbidity and mortality burdens. Diabetes medical nutrition therapy (MNT) improves glycemic, blood pressure, and cholesterol control, all critical in preventing and reducing diabetes complications. Yet, MNT does not address low motivation for dietary intake management, which is frequently reported among AA women with T2D living in the Southeastern US.

METHODS

A randomized controlled trial will be used to test the central hypothesis that diabetes MNT plus culturally-tailored motivational interviewing (MI) (diabetes MNT plus MI) is more effective than diabetes MNT alone (diabetes MNT). Two hundred ninety-one Southeastern AA women who are at risk for development and/or progression of T2D complications will be randomized to diabetes MNT plus MI or diabetes MNT. Both groups will include: 1) a 3-month active intervention period, consisting of group-based, nutritionist-facilitated MNT sessions; 2) a 3-month maintenance intervention period, including one group-based, nutritionist-facilitated maintenance support session; and 3) a 6-month inactive period. Culturally-adapted MI exercises will be integrated into the diabetes MNT plus MI group only. Primary (HbA1c) and secondary (systolic blood pressure, LDL cholesterol) outcomes will be assessed at baseline and 3, 6, and 12 months following the active intervention period.

DISCUSSION

The results from this study, called the SISTER (Sisters Inspiring Sisters to Engage in Relevant Diabetes Self-Care) Diabetes Study, are vital to the adoption and uptake of rigorously-tested MNT interventions that address motivation among AA women with T2D as a way to reduce their risk and/or progression of diabetes-related complications.

Transforming Medical Education to Provide Gender-Affirming Care for Transgender and Gender-Diverse Patients: A Policy Brief

Transgender and gender-diverse (TGD) patients experience a greater burden of health disparities compared with their heterosexual/cisgender counterparts. Some of the poorer health outcomes observed in these populations are known to be associated with the prevalence of implicit bias, bullying, emotional distress, alcoholism, drug abuse, intimate partner violence, sexually transmitted infections (eg, human immunodeficiency virus and human papilloma virus), and cancer. The TGD populations face unique barriers to receiving both routine and gender-affirming health care (acquiring hormones and gender-affirming surgeries). Additional barriers to implementing affirming care training for TGD patients are lack of expertise among medical education faculty and preceptors both in undergraduate and in graduate medical education programs. Drawing on a systematic review of the literature, we propose a policy brief aimed at raising awareness about gender-affirming care among education planners and policy makers in government and advisory bodies.

Curricular Interventions in Medical Schools: Maximizing Community Engagement Through Communities of Practice

This article explains the importance of a communities of practice (CoP) model for continually aligning medical education and clinical transformation with contemporary health issues. It describes the evolution and advantages of using CoP as a model for transforming medical education and clinical practice and applies the CoP methodology to addressing the changing needs of socially vulnerable populations (LGBTQ [lesbian, gay, bisexual, transgender, and queer/questioning], persons experiencing homelessness, and migrant farm workers). In conclusion, this article describes CoP-led activities, achievements, and value creation in medical education by the National Center for Medical Education Development and Research established at the Meharry Medical College.

The effect of motivational strategy on voluntary plasma donation, a field trial

BACKGROUND

Plasma protein therapies (PPTs) are a group of medicines extracted from human plasma through fractionation. The manufacture of adequate amounts of PPTs requires a large volume of human plasma. WHO emphasized that whole blood and blood component donations should be voluntary and non-remunerated. So, motivating people to donate plasma is crucial. In this study, we evaluated the impact of social media on motivating blood donors to donate plasma without any compensation and the moderating effects of blood donation history on plasma donation.

METHODS AND MATERIALS

we allocated blood donors (n = 501) to intervention and control groups randomly. Participants in the intervention group got educational and motivational messages through a WhatsApp channel. Then, we followed up all participants for six months and registered the information of the plasma donation during this period.

RESULT

In the intervention group, 6.8% had returned to donate plasma, while this was 2% in the control group (p = 0.016, OR:3.59, 95%CI:1.3-9.89). Among regular blood donors in the intervention group, 17.86% had returned to donate plasma but, no regular donor returned to donate plasma in the control group (p = 0.055). In addition, 10.8% of donors who had academic education in the intervention group returned to donate plasma, although this was 2.54% in the control group (P = 0.0485).

CONCLUSION

Our findings suggest that the educational interventions have more effects on academically educated donors to motivate them to donate plasma.

An Analysis of COVID-19 Mortality During the Dominancy of Alpha, Delta, and Omicron in the USA

BACKGROUND

The objective of the study was to measure the risk of death due to COVID-19 in relation to individuals' characteristics, and severity of their disease during the dominant periods of Alpha, Delta, and Omicron variants have influenced mortality rates.

METHODS

This study was conducted using COVID-19 Centers for Disease Control and Prevention (CDC) Case Surveillance Public Data Taskforce for 57 states, and United States territories between January 1, 2020 and March 20, 2022. Multivariable binary Hyperbolastic regression of type I was used to analyzes the data.

RESULTS

Seniors and ICU-admitted patients had the highest risk of death. For each additional percent increase in fully vaccinated individuals, the odds of death deceased by 1%. The odds of death prior to vaccine availability, compared to post vaccine availability, was 1.27. When comparing the time periods each variant was dominant, the odds of death was 3.45-fold higher during Delta compared to Alpha. All predictor variables had P-values ≤.001.

CONCLUSION

There was a noticeable difference in the odds of death among subcategories of age, race/ethnicity, sex, PMCs, hospitalization, ICU, vaccine availability, variant, and percent of fully vaccinated individuals.

The Effect of Naloxone Access Laws on Fatal Synthetic Opioid Overdose Fatality Rates

BACKGROUND

Increases in fatal synthetic opioid overdoses over the past 8 years have left states scrambling for effective means to curtail these deaths. Many states have implemented policies and increased service capacity to address this rise. To better understand the effectiveness of policy level interventions we estimated the impact of the presence of naloxone access laws (NALs) on synthetic opioid fatalities at the state level.

METHODS

A multivariable longitudinal linear mixed model with a random intercept was used to determine the relationship between the presence of NALs and synthetic opioid overdose death rates, while controlling for, Good Samaritan laws, opioid prescription rate, and capacity for medication for opioid use disorder (MOUD), utilizing a quadratic time trajectory. Data for the study was collected from the National Vital Statistics System using multiple cause-of-death mortality files linked to drug overdose deaths.

RESULTS

The presence of an NAL had a significant (univariate P-value = .013; multivariable p-value = .010) negative relationship to fentanyl overdose death rates. Other significant controlling variables were quadratic time (univariate and multivariable P-value < .001), MOUD (univariate P-value < .001; multivariable P-value = .009), and Good Samaritan Law (univariate P-value = .033; multivariable P-value = .018).

CONCLUSION

Naloxone standing orders are strongly related to fatal synthetic opioid overdose reduction. The effect of NALs, MOUD treatment capacity, and Good Samaritan laws all significantly influenced the synthetic opioid overdose death rate. The use of naloxone should be a central part of any state strategy to reduce overdose death rate.

The COVID-19 Vaccine and Pregnant Minority Women in the US: Implications for Improving Vaccine Confidence and Uptake

The American College of Obstetricians and Gynecologists (AGOG) recommends the FDA-approved Pfizer and Moderna mRNA COVID-19 vaccines and boosters for all eligible pregnant women in the US. However, COVID-19 vaccine confidence and uptake among pregnant minority women have been poor. While the underlying reasons are unclear, they are likely to be associated with myths and misinformation about the vaccines. Direct and indirect factors that deter minority mothers in the US from receiving the mRNA COVID-19 vaccines require further investigation. Here, we examine the historical perspectives on vaccinations during pregnancy. We will examine the following aspects: (1) the influenza and tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccinations during pregnancy; (2) the exclusion of pregnant and lactating women from COVID-19 vaccine trials; (3) COVID-19 vaccine safety during pregnancy, obstetric complications associated with symptomatic COVID-19 during pregnancy, COVID-19 vaccine hesitancy among pregnant minority women, and racial disparities experienced by pregnant minority women due to the COVID-19 pandemic as well as their potential impact on pregnancy care; and (4) strategies to improve COVID-19 vaccine confidence and uptake among pregnant minority women in the US. COVID-19 vaccine hesitancy among minority mothers can be mitigated by community engagement efforts that focus on COVID-19 vaccine education, awareness campaigns by trusted entities, and COVID-19-appropriate perinatal counseling aimed to improve COVID-19 vaccine confidence and uptake.

Breakthrough COVID-19 Infections in the US: Implications for Prolonging the Pandemic

The incidence of COVID-19 breakthrough infections-an infection that occurs after you have been vaccinated-has increased in frequency since the Delta and now Omicron variants of the SARS-CoV-2 coronavirus have become the dominant strains transmitted in the United States (US). Evidence suggests that individuals with breakthrough infections, though rare and expected, may readily transmit COVID-19 to unvaccinated populations, posing a continuing threat to the unvaccinated. Here, we examine factors contributing to breakthrough infections including a poor immune response to the vaccines due to the fact of advanced age and underlying comorbidities, the natural waning of immune protection from the vaccines over time, and viral variants that escape existing immune protection from the vaccines. The rise in breakthrough infections in the US and how they contribute to new infections, specifically among the unvaccinated and individuals with compromised immune systems, will create the need for additional booster vaccinations or development of modified vaccines that directly target current variants circulating among the general population. The need to expedite vaccination among the more than 49.8 million unvaccinated eligible people in the US is critical.

The effect of homelessness on viral suppression in an underserved metropolitan area of middle Tennessee: potential implications for ending the HIV epidemic

BACKGROUND

A wealth of scientific evidence supports the effectiveness of HIV prophylaxis and treatment. Homelessness is strongly associated with the health status and viral suppression among underserved populations and can undermine the national plan to eliminate HIV by 2030. This retrospective observational study examined the extent in which homelessness affects HIV treatment in an underserved urban area of Middle Tennessee in 2014-2019.

RESULTS

Among 692 HIV-seropositive patients, the proportion of homeless patients increased from 13.5% in 2014 to 27.7% in 2019, thrice the national average for HIV-seropositive people (8.4%) and twice that of HIV positive patients who are participating in Ryan White programs nationwide (12.9%). Our findings suggest that homeless patients were half as likely to achieve viral suppression as compared to those who had a permanent/stable home [OR 0.48 (0.32-0.72), p-value < 0.001].

CONCLUSION

Our study indicates that homelessness may play an important role in viral suppression among persons living with HIV/AIDS in Middle Tennessee.

Correction to: An introduction to new robust linear and monotonic correlation coefficients

An amendment to this paper has been published and can be accessed via the original article.

Mechanistic role of antioxidants in rescuing delayed gastric emptying in high fat diet induced diabetic female mice

Diabetic gastroparesis (DG) exhibits delayed gastric emptying (GE) due to impaired gastric non-adrenergic, non-cholinergic (NANC) relaxation. These defects are due to loss or reduction of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) that causes reduced expression and/or dimerization of neuronal nitric oxide synthase alpha (nNOSα) gene expression and function. We investigated the effect of potent Nrf2 activators (cinnamaldehyde [CNM] & curcumin [CUR]) on GE in obesity-induced diabetic female mice. We fed adult female homozygous Nfe2l2-/- (Nrf2 KO) and wild-type (WT) female mice with either a high-fat diet (HFD) or a normal diet (ND) for a period of 16 weeks. Groups of HFD mice were fed with CUR or CNM either at 6th or 10th week respectively. Our results demonstrate that supplementation of CNM or CUR restored impaired nitrergic relaxation and attenuated delayed GE in HFD fed mice. Supplementation of CNM or CUR normalized altered gastric antrum protein expression of (1) p-ERK/p-JNK/MAPK/p-GSK-3β, (2) BH4 (Cofactor of nNOS) biosynthesis enzyme GCH-1 and the GSH/GSSG ratio, (3) nNOSα protein & dimerization and soluble guanylate cyclase (sGC), (4) AhR and ER expression, (5) inflammatory cytokines (TNF α, IL-1β, IL-6), (6)TLR-4, as well as (7) reduced oxidative stress markers in WT but not in Nrf2 KO obesity-induced chronic diabetic female mice. Immunoprecipitation experiments revealed an interaction between nNOS and Nrf2 proteins. Our results conclude that Nrf2 activation restores nitrergic-mediated gastric motility and GE by normalizing inflammation and oxidative stress induced by obesity-induced chronic diabetes.

An introduction to new robust linear and monotonic correlation coefficients

BACKGROUND

The most common measure of association between two continuous variables is the Pearson correlation (Maronna et al. in Safari an OMC. Robust statistics, 2019. https://login.proxy.bib.uottawa.ca/login?url=https://learning.oreilly.com/library/view/-/9781119214687/?ar&orpq&email=^u). When outliers are present, Pearson does not accurately measure association and robust measures are needed. This article introduces three new robust measures of correlation: Taba (T), TabWil (TW), and TabWil rank (TWR). The correlation estimators T and TW measure a linear association between two continuous or ordinal variables; whereas TWR measures a monotonic association. The robustness of these proposed measures in comparison with Pearson (P), Spearman (S), Quadrant (Q), Median (M), and Minimum Covariance Determinant (MCD) are examined through simulation. Taba distance is used to analyze genes, and statistical tests were used to identify those genes most significantly associated with Williams Syndrome (WS).

RESULTS

Based on the root mean square error (RMSE) and bias, the three proposed correlation measures are highly competitive when compared to classical measures such as P and S as well as robust measures such as Q, M, and MCD. Our findings indicate TBL2 was the most significant gene among patients diagnosed with WS and had the most significant reduction in gene expression level when compared with control (P value = 6.37E-05).

CONCLUSIONS

Overall, when the distribution is bivariate Log-Normal or bivariate Weibull, TWR performs best in terms of bias and T performs best with respect to RMSE. Under the Normal distribution, MCD performs well with respect to bias and RMSE; but TW, TWR, T, S, and P correlations were in close proximity. The identification of TBL2 may serve as a diagnostic tool for WS patients. A Taba R package has been developed and is available for use to perform all necessary computations for the proposed methods.

Pre-Exposure Prophylaxis Training among Medical Schools in the United States

Pre-Exposure Prophylaxis (PrEP) has been shown to be an effective method of HIV prevention for men who have sex with-men (MSM) and -transgender women (MSTGWs), serodiscordant couples, and injection drug users; however fewer than 50 000 individuals currently take this regimen. Knowledge of PrEP is low among healthcare providers and much of this lack of knowledge stems from the lack or exposure to PrEP in medical school. We conducted a cross sectional survey of medical schools in the United States to assess the degree to which PrEP for HIV prevention is taught. The survey consisted Likert scale questions assessing how well the students were prepared to perform each skill associated with PrEP delivery, as well as how PrEP education was delivered to students. We contacted 141 medical schools and 71 responded to the survey (50.4%). PrEP education was only reported to be offered at 38% of schools, and only 15.4% reported specific training for Lesbian, Gay, Bisexual, and Transgender (LGBT) patients. The most common delivery methods of PrEP content were didactic sessions with 11 schools reporting this method followed by problem-based learning, direct patient contact, workshops, and small group discussions. Students were more prepared to provide PrEP to MSM compared to other high-risk patients. Few medical schools are preparing their students to prescribe PrEP upon graduation. Further, there is a need to increase the number of direct patient contacts or simulations for students to be better prepared.

Recommendations for Increasing Physician Provision of Pre-Exposure Prophylaxis: Implications for Medical Student Training

There is growing evidence that pre-exposure prophylaxis (PrEP) prevents HIV acquisition. However, in the United States, approximately only 4% of people who could benefit from PrEP are currently receiving it, and it is estimated only 1 in 5 physicians has ever prescribed PrEP. We conducted a scoping review to gain an understanding of physician-identified barriers to PrEP provision. Four overarching barriers presented in the literature: Purview Paradox, Patient Financial Constraints, Risk Compensation, and Concern for ART Resistance. Considering the physician-identified barriers, we make recommendations for how physicians and students may work to increase PrEP knowledge and competence along each stage of the PrEP cascade. We recommend adopting HIV risk assessment as a standard of care, improving physician ability to identify PrEP candidates, improving physician interest and ability in encouraging PrEP uptake, and increasing utilization of continuous care management to ensure retention and adherence to PrEP.

Modeling dynamics of fatal opioid overdose by state and across time

Opioid overdose fatalities include deaths from natural opioids (morphine and codeine), semi-synthetic opioids (oxycodone, hydrocodone), synthetic opioids (prescription and illicit fentanyl, tramadol), methadone, and heroin. From 1999 to 2017, there were 702,568 drug overdose deaths in the U.S., with 399,230 attributed to opioids. This study aimed to assess the dynamics of opioid related fatalities throughout the U.S. from 2006-2016. This study is a secondary analysis of data obtained through the Kaiser Family Foundation's analysis of Centers for Disease Control and Prevention data, 1999-2016. The data obtained were from all 50 states and the District of Columbia. A total of 272,130 individuals were included in the analysis. This represents the number of opioid overdose deaths in the United States from 2006-2016. Descriptive analysis of overall rates was conducted and mapped for visualization. Novel predictive models of increase for each drug overdose category were developed and used to calculate rate changes. Finally, the elasticity of change in rate for each drug category was calculated annually for the past 11 years. The highest rate of opioid overdose-related death occurred in West Virginia (40.03 per 100,000). In our secondary analysis, we explored the change in the rate of opioid-related deaths from 2015 to 2016. The changing dynamics of fatal opioid overdose at the state level is critical to guiding policy makers in addressing this crisis. Rates of fatal opioid overdose vary across the states, but we identify some trends. Regional differences are identified in states with the highest overdose rates from all opioids combined.

Pressurized liquid extraction followed by liquid chromatography coupled to a fluorescence detector and atmospheric pressure chemical ionization mass spectrometry for the determination of benzo(a)pyrene metabolites in liver tissue of an animal model of colon cancer

Since metabolism is implicated in the carcinogenesis of toxicants, an efficient extraction method together with an analytical method is warranted to quantify tissue burdens of a carcinogen and/or its metabolites. Therefore, the aim of this study was to validate a pressurized liquid extraction (PLE) method for measuring metabolites of benzo(a)pyrene [B(a)P; a food-borne carcinogen] from tissue samples. The sample extraction was performed separately by PLE and liquid-liquid extraction (LLE). PLE followed by high-performance liquid chromatography coupled to online fluorescence detector (HPLC-FLD) was used to quantify separated analytes; and by ultra-high-performance liquid chromatography (UHPLC) coupled to atmospheric pressure chemical ionization tandem mass spectrometry (UHPLC-APCI-MS/MS) were used for confirmation purposes. The UHPLC-MS/MS was set-up in the atmospheric pressure chemical ionization (APCI) positive interface with selective reaction monitoring (SRM). The analytical performance characteristics of the PLE technique was assessed at different temperatures, pressure, number of cycles and solvent types. A methanol + chloroform + water mixture (30:15:10, v/v/v) yielded greater recoveries at an extraction temperature range of 60-80°C, pressure of 10 MPa and an extraction time of 10 min. The PLE method was validated by the analysis of spiked tissue samples and measuring recoveries and limits of quantitation for the analytes of interest using HPLC-FLD equipment. The optimized PLE-HPLC-FLD method was used to quantify the concentrations of B(a)P metabolites in liver samples obtained from a colon cancer animal model. Overall, PLE performed better in terms of extraction efficiency, recovery of B(a)P metabolites and shortened sample preparation time when compared with the classic LLE method.

Abstract B129: Does insurance status explain the racial disparity in survival outcome seen in upper aerodigestive tract cancers in the United States?

Upper Aerodigestive tract (UADT) cancers are primarily squamous cell carcinomas that affect the oral cavity (hard palate, front 2/3 of tongue, gums, mucosal lining of lips and cheeks, and the floor of the mouth), oropharynx (base of the tongue, soft palate, and tonsils), hypopharynx, larynx (epiglottis and vocal cords), and the upper third of the esophagus with a five-year survival rate of 65.3% for oral cavity and pharyngeal cancers. If the cancer is detected during the localized stage, the survival rate improves to 84.4% (SEER 18 2009-2015).There have been several risk factors implicated in the pathogenesis of UADT cancers such as, male gender, smoking, alcohol use, and infection with human papilloma virus (HPV) for oropharyngeal cancers. The current literature suggests that regardless of stage people of African descent have a lower incidence of UADT cancers, but higher mortality rates compared to Caucasians. There are many proposed explanations for this paradoxical trend seen in African Americans. However, there is a paucity of research addressing this problem. We seek to understand if socioeconomic status is the underlying factor driving this disparity. We analyzed de-identified data collected from the Surveillance, Epidemiology, and End Results (SEER) program for 114,510 UADT cancer patients diagnosed from 2007-2016. We hypothesized that people who were uninsured or on Medicaid would have a life expectancy that was significantly reduced compared to those that had private insurance or Medicare regardless of race, tumor grade, gender or site of the cancer. Our study design is retrospective cohort. Our multivariate analysis model utilizes survival analysis techniques such as Kaplan-Meier survival, hazard curves and proportional hazards regression to analyze the survival time of our patients as a function of demographic and clinical variables. Survival months ranged from 0 to 119 months, with 25,122 patients experiencing death due to UADT cancers. The proportional hazards regression revealed that across all insurance groups (Insured, Uninsured, Medicaid, and Unknown) the survival time for Non-Hispanic Black People was significantly reduced compared to the other race/ethnicities (Asians, Caucasians, Hispanics (all races)) with Non-Hispanic Caucasians having the highest survival rate. Determining that the racial disparity exists regardless of insurance status, tumor grade, gender, and site of cancer can guide future researchers to focus on biological differences or other factors such as lack of access to care that underlie disease survival for UADT cancers.

Citation Format: Joycemary G Amponsem, Dana Marshall, Derek Wilus, Mohammad Tabatabai. Does insurance status explain the racial disparity in survival outcome seen in upper aerodigestive tract cancers in the United States? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B129.

The Effects of Social, Personal, and Behavioral Risk Factors and PM2.5 on Cardio-Metabolic Disparities in a Cohort of Community Health Center Patients

(1) Background: Cardio-metabolic diseases (CMD), including cardiovascular disease, stroke, and diabetes, have numerous common individual and environmental risk factors. Yet, few studies to date have considered how these multiple risk factors together affect CMD disparities between Blacks and Whites. (2) Methods: We linked daily fine particulate matter (PM2.5) measures with survey responses of participants in the Southern Community Cohort Study (SCCS). Generalized linear mixed modeling (GLMM) was used to estimate the relationship between CMD risk and social-demographic characteristics, behavioral and personal risk factors, and exposure levels of PM2.5. (3) Results: The study resulted in four key findings: (1) PM2.5 concentration level was significantly associated with reported CMD, with risk rising by 2.6% for each µg/m3 increase in PM2.5; (2) race did not predict CMD risk when clinical, lifestyle, and environmental risk factors were accounted for; (3) a significant variation of CMD risk was found among participants across states; and (4) multiple personal, clinical, and social-demographic and environmental risk factors played a role in predicting CMD occurrence. (4) Conclusions: Disparities in CMD risk among low social status populations reflect the complex interactions of exposures and cumulative risks for CMD contributed by different personal and environmental factors from natural, built, and social environments.

Preparing Medical Students to Address the Needs of Vulnerable Patient Populations: Implicit Bias Training in US Medical Schools

Little is known about how medical students are trained to identify and reduce their own biases toward vulnerable patient groups. A survey was conducted among US medical schools to determine whether their curricula addressed physician implicit biases toward three vulnerable patient groups: lesbian, gay, bisexual, transgender, and questioning (LGBTQ) individuals, persons experiencing homelessness, and migrant farmworkers. Of 141 US medical schools, 71 (50%) responded. Survey respondents indicated that implicit bias is not routinely addressed in medical education, and training specific to vulnerable populations is infrequent. Recommendations for incorporating implicit bias training in medical school curricula are discussed.

Hepatitis C Coinfection and Mortality in People Living with HIV in Middle Tennessee

HIV and hepatitis C virus (HCV) coinfection is associated with poor health outcomes. This study was designed to assess risk factors for and mortality with coinfection before direct-acting antiviral treatment availability in a state with an evolving opioid epidemic. HCV infection was determined from review of the medical record at two clinics serving the majority of people living with HIV (PLWH) in care in Middle Tennessee from 2004 to 2013. Association of potential risk factors with HCV-positivity was assessed using logistic regression. Association of HCV-positivity with mortality was assessed with a Cox proportional hazards model, adjusting for selected covariates. A total of 3,501 patients were included: 24% female; 51% men who have sex with men; 47% white; 44% African American/black; median age of 38 at their first visit; median most recent CD4 count 502 cells/μL (301-716); and HIV viral load 47 copies/mL (39-605); followed for a median of 3.0 (1-5) years. Prevalence of HCV was 13%. Those with a history of injection drug use (IDU) demonstrated the highest odds of HCV-positivity [odds ratio 12.94; 95% confidence interval (CI) 9.39-17.83]. There were 305 deaths; median age at death was 47 years (40-53). HCV coinfection was associated with greater mortality (hazard ratio 1.61; 95% CI 1.20-2.17; p < .001). Among PLWH, HCV coinfection was associated with IDU and an independent predictor of mortality. These results affirm the importance of HCV coinfection and inform interventions targeting the continuum of HCV care, uptake of HCV treatment, and the impact of drug use in this population.

Adherence to Combination Antiretroviral Therapy among Pregnant Women Enrolled in a HIV Prevention Program in Rural North-central Nigeria

OBJECTIVE

Adherence to combination antiretroviral therapy (ART) among pregnant women is essential to attaining the goal of eliminating mother-to-child HIV transmission. The objective of this study was to determine which factors affect adherence to ART among HIV-positive women enrolled in a large prevention of mother-to-child HIV transmission (PMTCT) trial in rural north-central Nigeria.

METHODS

The parent study included 372 HIV-positive pregnant women enrolled in a cluster-randomized control trial conducted at 12 health facilities in Nigeria between 2013 and 2015. This secondary analysis included HIV-positive women (and their infants) from the original trial with documented adherence data (n=210, 56.5%). The primary outcome was maternal adherence to ART, determined by self-report and based on the visual analogue scale (VAS) of a validated medication adherence tool. Participants with a VAS score of ≥ 95% were classified as adherent. We employed multivariate logistic regression to evaluate the predictors of maternal ART adherence in the study sample.

RESULTS

Approximately 61.0% of study participants (128/210) were adherent to ART. The majority of adherent participants (62.5%, 80/128) were enrolled in the trial intervention arm. The most common cited response for non-adherence was fear of status disclosure. Adherence to ART was associated with study arm (intervention arm vs. control arm, adjusted Odds Ratio (aOR) [95% CI]: 16.95 [5.30-54.23]), maternal ethnicity (Gwari vs. Other, aOR = 0.13 [0.05-0.38]), and partner HIV status (HIV-positive vs. unknown, aOR = 3.14 [1.22-8.07]).

CONCLUSION AND GLOBAL HEALTH IMPLICATIONS

Adherence to ART among a cohort of pregnant women enrolled in a PMTCT trial in rural North-Central Nigeria was associated with trial arm, maternal self-reported ethnicity, and partner's HIV status. Increased understanding of the interplay between these factors will enable the development of more targeted and effective interventions.

Training to reduce LGBTQ-related bias among medical, nursing, and dental students and providers: a systematic review

BACKGROUND

Lesbian, gay, bisexual, transgender and questioning (LGBTQ) individuals experience higher rates of health disparities. These disparities may be driven, in part, by biases of medical providers encountered in health care settings. Little is known about how medical, nursing, or dental students are trained to identify and reduce the effects of their own biases toward LGBTQ individuals. Therefore, a systematic review was conducted to determine the effectiveness of programs to reduce health care student or provider bias towards these LGBTQ patients.

METHODS

The authors performed searches of online databases (MEDLINE/PubMed, PsycINFO, Web of Science, Scopus, Ingenta, Science Direct, and Google Scholar) for original articles, published in English, between March 2005 and February 2017, describing intervention studies focused on reducing health care student or provider bias towards LGBTQ individuals. Data extracted included sample characteristics (i.e., medical, nursing, or dental students or providers), study design (i.e., pre-post intervention tests, qualitative), program format, program target (i.e., knowledge, comfort level, attitudes, implicit bias), and relevant outcomes. Study quality was assessed using a five-point scale.

RESULTS

The search identified 639 abstracts addressing bias among medical, nursing, and dental students or providers; from these abstracts, 60 articles were identified as medical education programs to reduce bias; of these articles, 13 described programs to reduce bias towards LGBTQ patients. Bias-focused educational interventions were effective at increasing knowledge of LGBTQ health care issues. Experiential learning interventions were effective at increasing comfort levels working with LGBTQ patients. Intergroup contact was effective at promoting more tolerant attitudes toward LGBTQ patients. Despite promising support for bias education in increasing knowledge and comfort levels among medical, nursing, and dental students or providers towards LGBTQ persons, this systematic review did not identify any interventions that assessed changes in implicit bias among students or providers.

CONCLUSIONS

Strategies for assessing and mitigating implicit bias towards LGBTQ patients are discussed and recommendations for medical, nursing, and dental school curricula are presented.

Influence of Intimate Partner Violence (IPV) Exposure on Cardiovascular and Salivary Biosensors: Is There a Relationship?

BACKGROUND/PURPOSE

Intimate partner violence (IPV) is a global public health epidemic that initiates/exacerbates health consequences affecting a victim's lifespan. IPV can significantly predispose women to a lifetime risk of developing cardiovascular disease (CVD) due to the effects of stress and inflammation. This study investigates the correlation among IPV exposure, in-vivo CVD events, and inflammatory biomarkers as predictor indices(s) for CVD in female dental patients.

METHODS

Of 37 women enrolled in this study, 19 were African-American (AA) and 18 non-African-American (non-AA) and their ages ranged from 19 to 63 years. IPV-exposure and stress-induced in-vivo CVD events such as Chest Pain (CP) and Heart palpitations were recorded from all enrolled subjects. Cardiovascular events were obtained through surveys by patient self-report. Saliva specimens were obtained from all women and were analyzed for CVD biomarkers using multiplex-ELISA.

RESULTS

The prevalence of IPV was 51% (19/37) and statistically equivalent for AA and non-AA. The results show differences in experience of 1) CP (p < 0.01) and 2) heart palpitations (p < 0.02) when IPV + participants are compared with IPV- AA and non-AA cohorts. Of 10 CVD biomarkers analyzed, significant correlations between IPV+ and IPV- subjects were observed for biomarkers that include Interleukin-1β/sCD40L; TNFα/sCD40L; Myoglobin/IL-1β; CRP/sCD40L; CRP/IL-6; CRP/TNFα; TNFα/siCAM; CRP/MMP9; TNF-α/Adiponectin (p < 0.01).

DISCUSSION/IMPLICATIONS

Analysis of in vivo CVD status showed that significant race/health disparities exist in IPV + cohorts, as well as increased expression of inflammatory mediators, specifically CRP, IL-1β, IL-6, MMP9. Women who have experienced IPV may be a target cohort for primary prevention of CVD. The use of salivary biomarkers and our protocol may provide a less invasive method to help increase identification of victims at risk for IPV and CVD and potentially decrease other health injuries associated with IPV exposure.

Hyperbolastic growth models: theory and application

Background

Mathematical models describing growth kinetics are very important for predicting many biological phenomena such as tumor volume, speed of disease progression, and determination of an optimal radiation and/or chemotherapy schedule. Growth models such as logistic, Gompertz, Richards, and Weibull have been extensively studied and applied to a wide range of medical and biological studies. We introduce a class of three and four parameter models called "hyperbolastic models" for accurately predicting and analyzing self-limited growth behavior that occurs e.g. in tumors. To illustrate the application and utility of these models and to gain a more complete understanding of them, we apply them to two sets of data considered in previously published literature.

Results

The results indicate that volumetric tumor growth follows the principle of hyperbolastic growth model type III, and in both applications at least one of the newly proposed models provides a better fit to the data than the classical models used for comparison.

Conclusion

We have developed a new family of growth models that predict the volumetric growth behavior of multicellular tumor spheroids with a high degree of accuracy. We strongly believe that the family of hyperbolastic models can be a valuable predictive tool in many areas of biomedical and epidemiological research such as cancer or stem cell growth and infectious disease outbreaks.

Treatment of de Quervain's disease

This study compared the use of a mixed steroid/lidocaine injection alone, an immobilization splint alone, and the simultaneous use of both in improving symptoms in de Quervain's disease. Ninety-three wrists were included in the study, with an average follow-up examination of 13 months. Complete relief of symptoms was noted in 28 of 42 wrists receiving an injection alone, 8 of 14 wrists receiving both an injection and splint, and 7 of 37 wrists receiving a splint alone. No significant difference was noted between the injection alone and injection plus splint groups. A significant difference was seen between the injection alone and splint alone groups and the injection/splint and splint alone groups. Twenty of 45 wrists that underwent operative release demonstrated a septum at the first dorsal compartment. When the need for operative release was used as an outcome result for treatment failure, the injection alone and splint alone groups demonstrated significance. We recommend the use of a mixed steroid/lidocaine injection alone as the initial treatment of choice in this condition. No additional benefit is appreciated by the addition of splint immobilization and, in fact, patients are less restricted with a lower financial burden without its use.

Changes in serum CPK, LDH, and their isoenzymes in the perioperative period in patients undergoing craniotomy

The perioperative changes in the serum concentration of creatine phosphokinase (CPK) and its isoenzymes MM, MB, and BB and of lactic dehydrogenase (LDH) and its isoenzymes LDH1 to LDH5 were determined during craniotomy in order to distinguish operation-induced changes in these enzymes from those due to acute myocardial infarction and malignant hyperthermia. Twenty-eight male patients, 29 to 76 years of age (mean +/- SD = 58 +/- 13.2 years), undergoing craniotomy for tumor reseaction (n = 26) or cerebral artery aneurysm clipping (n = 2) were included in this study. Ten serial blood samples were obtained from each patient: one sample before and another after induction of anesthesia, and eight samples after the incision, over a period of 70 h. The preinduction serum CPK level of 97 +/- 32 U/L (mean +/- SD) increased gradually and significantly and reached the peak level of 542 +/- 116 U/L 34 h after incision (p <0.05). Whereas all of the CPK isoenzymes increased in terms of U/L after incision, only the MM fraction (expressed as percent of total CPK) increased, and the MB and BB fractions (expressed as percent of total CPK) decreased. The preinduction serum LDH level of 150 +/- 42 U/L (mean +/- SD) increased gradually after incision and reached the peak level of 210 +/- 32 U/L 58 h after incision (p <0.05). LDH2 as a percent of total LDH decreased significantly, but the LDH1/LDH2 ratio did not change. LDH4 and LDH5, as percents of total LDH, increased significantly. The large increases in total serum CPK and the concomitant decrease in MB percent after craniotomy may minimize and/or mask the percentage increase in the MB level following acute myocardial infarction. The perioperative serum CPK level as a marker in the diagnosis of malignant hyperthermia should be interpreted in light of the present results and in conjunction with clinical symptomatology.

Enflurane depresses activity of the medullary inspiratory neurons in the cat

The effect of enflurane on the firing activity (spikes/sec) of the inspiratory neurons of the dorsal respiratory group (DRG) of the medulla oblongata was studied in decerebrate, paralyzed, mechanically ventilated cats before and after bilateral cervical vagotomy. Inspiratory neuronal activity, phrenic neurogram, arterial blood pressure, tracheal pressure, and end tidal CO2 concentration were recorded. Cells whose firing activity was in phase with that of the phrenic nerve were considered inspiratory neurons. Administration of 1 and 2% enflurane in oxygen produced gradual, significant, and dose-dependent depression of the cell activity with cervical vagi either intact or severed. Recovery of the cell activity occurred after termination of enflurane administration. In cats with intact vagi, 10 min after introduction of 1 and 2% enflurane, the cell activity (mean +/- SE) expressed as percentage of the control was 70 +/- 6% (P less than 0.05) and 48 +/- 5% (P less than 0.01), respectively. Bilateral cervical vagotomy did not affect the degree of cell depression due to enflurane. Hypercarbia induced by inhalation of 5% CO2 increased cell activity, but it did not block enflurane-induced cell depression, although it reduced it. It may be concluded that enflurane depresses the activity of the inspiratory neurons of the DRG. The results also suggest that the respiratory depressant effect of enflurane has a central component and that the DRG region may serve as a site to mediate the enflurane-induced respiratory depression.

Mechanism of action of local anesthetics on synaptic transmission in the rat

The mechanism of action of local anesthetics on synaptic transmission and their effects on synaptic components and on electrophysiologic properties of the nerve cell body are not clear. Therefore, the effects of lidocaine and bupivacaine on pre- and postsynaptic mechanisms underlying synaptic transmission in sympathetic ganglia were studied utilizing the techniques of intracellular recording and stimulation on isolated superfused superior cervical ganglia of rats. Lidocaine and bupivacaine either depressed or completely blocked synaptic transmission in sympathetic ganglia in a dose-dependent manner. Blockade of axonal conduction in presynaptic fibers was preceded by increased latency (the latency increased from 11.2 +/- 0.9 to 16.5 +/- 1.4 ms, mean +/- SEM, P less than 0.01) when the drugs were applied to the presynaptic nerves. Application of the drugs directly to the ganglion produced alterations in postsynaptic membrane properties consisting of decreased membrane resistance (from 40 +/- 3 to 32 +/- 3 M omega, P less than 0.01), increased firing threshold (from 14 +/- 0.5 to 18 +/- 0.5 mV, P less than 0.01), and decreased action potential amplitude (P less than 0.01) and/or blockade of action potential generation. Resting postsynaptic membrane potential did not change significantly. These changes were reversible. However, even after the excitatory postsynaptic potential resulting from presynaptic nerve stimulation had fully recovered during washout of the local anesthetic, the threshold for evoking the spike potential (firing level) still remained elevated for both presynaptic and intracellular stimulation of the ganglion cell, suggesting prolonged cell depression.(ABSTRACT TRUNCATED AT 250 WORDS)

Disruption of the rhythmic activity of the medullary inspiratory neurons and phrenic nerve by fentanyl and reversal with nalbuphine

The effects of intravenous administration of fentanyl (50 and 100 micrograms/kg) on the discharge activity of the medullary inspiratory neurons and of the phrenic nerve were studied following vagotomy in nine decerebrate, paralyzed mechanically ventilated cats. In six cats, the inspiratory neurons explored were in the dorsal respiratory group (DRG) associated with the nucleus of the tractus solitarius (NTS), while in the remaining three, they were in the ventral respiratory group (VRG). In the former group, the rhythmic discharge of the inspiratory neurons was disrupted by fentanyl and replaced by a continuous discharge superimposed with irregularly occurring bursts. These changes were also reflected by the phrenic nerve discharge. Inspiratory neuronal activity increased significantly (P less than 0.05) at 1 and 5 min after completion of fentanyl injection. Disruption of the rhythmic activity of the inspiratory neurons and its replacement by a continuous and irregular discharge may lead to sustained contraction of inspiratory muscles and cessation of respiration. In the VRG, the activity of the inspiratory neurons was totally abolished by fentanyl. Thus, it appears that different groups of medullary inspiratory neurons have differential sensitivity to fentanyl. Nalbuphine, an opiate agonist-antagonist, restored the normal pattern and magnitude of the activity of the inspiratory neurons.

Comparison of cardiopulmonary variables with intermittent positive pressure ventilation and high-frequency jet ventilation during abdominal aortic operations

Cardiopulmonary variables with intermittent positive pressure ventilation (IPPV) and high-frequency jet ventilation (HFJV) were compared in 8 patients undergoing elective abdominal aortic operations under fentanyl-nitrous oxide anesthesia. Hemodynamics were stable under the two methods of ventilation, and most of the corresponding hemodynamic variables were statistically indifferent from each other. Alveolar gas exchange was also adequate with either method and most of the corresponding respiratory variables were not statistically different. The peak airway pressure was significantly less during HFJV than during IPPV (p less than 0.01). Diaphragmatic excursions are less during HFJV than during IPPV, resulting in a quieter surgical field. Therefore, hemodynamic stability and gas exchange adequacy coupled with less diaphragmatic excursions and lower peak airway pressure make HFJV an acceptable alternative to IPPV during abdominal aortic operations.

Serum creatine phosphokinase, lactic dehydrogenase, and their isoenzymes in the perioperative period

The purpose of the present investigation was to determine the normal perioperative variations in the serum concentration of creatine phosphokinase (CPK) and its isoenzymes MM, MB, and BB, and of lactic dehydrogenase (LDH) and its isoenzymes LDH1 to LDH5 to distinguish operation-induced changes in these enzymes from those due to acute myocardial infarction or malignant hyperthermia. In 30 patients, 52 to 75 years of age undergoing elective orthopedic operations, 10 serial blood samples were obtained in the perioperative period: two samples before skin incision and eight samples after the incision over a time span of 70 hours. The preinduction mean serum CPK level of 141 U/L increased gradually and significantly and reached a maximum mean concentration of 809 U/L 34 hours after incision (p less than 0.01). The CPK-MM percent increased after incision, whereas that of CPK-MB and CPK-BB decreased, although their absolute values in terms of U/L rose. The preinduction mean serum LDH value of 173 U/L increased gradually after incision and achieved peak levels at 34 hours (203 U/L) and 58 hours (210 U/L) after incision (p less than 0.05). The LDH1:LDH2 ratio did not change. The LDH5 percent increased and peaked 10 hours after incision (p less than 0.05). There was a significant correlation between severity of operation-induced tissue damage and the serum CPK concentration (p less than 0.001). The large increase in total CPK (primarily MM fraction) occurring after surgery may minimize the percentile effects caused by an increase in MB level due to myocardial infarction.

Effects of halothane on medullary inspiratory neurons of the cat

The effect of halothane on the electrical activity of inspiratory neurons of the nucleus tractus solitarius (NTS) was studied in decerebrate, paralyzed, mechanically ventilated cats. Simultaneous recording of the activity of the neurons of the NTS and the phrenic nerve was done to identify the inspiratory neurons. Cells whose firing activity was synchronous with that of the phrenic nerve were considered inspiratory neurons. Administration of 1% and 1.5% halothane in oxygen induced a dose-dependent depression of the cell activity (spikes/s) with the cervical vagi intact or severed. Five and ten minutes after inhalation of 1% halothane, the cell activity (mean +/- SE) expressed as per cent of the control was 55.3 +/- 9 and 27 +/- 7, respectively (P less than 0.001), before bilateral cervical vagotomy. The corresponding values for 1.5% halothane were 25 +/- 10.1 and 5.6 +/- 3, respectively. Upon termination of halothane administration, the cell activity gradually returned toward the control level. The cell response to halothane was not affected by bilateral cervical vagotomy. Hypercapnia produced by inhalation of 5% CO2 increased the cell activity, but halothane caused profound depression of the cells even in the presence of hypercapnia. Based on these results, it may be concluded that: halothane has inhibitory effects on the activity of the inspiratory neurons of the NTS; and halothane-induced respiratory depression has a central component and that the NTS may serve as a site of action of halothane for its respiratory depressant effect.

Persistence of polymicrobial abscesses in the poorly controlled diabetic host

Polymicrobial infections are frequently found in soft tissue infections of the lower extremities in diabetic patients. The relative susceptibility to and persistence of soft tissue polymicrobial infections of diabetic and nondiabetic mice using bacteria commonly found in clinical foot infections were studied. Subcutaneous abscesses were induced in three groups of diabetic and nondiabetic mice using: (1) E. coli and enterococcus, (2) enterococcus and Bacteroides fragilis (B. fragilis), and (3) E. coli and B. fragilis. Abscesses were removed at 1 and 2 wk for total colony counts. At 1 wk, there was a significantly greater bacterial growth in the abscesses of the diabetic mice compared with the nondiabetic mice only in the group injected with enterococcus and B. fragilis. There were significantly higher colony counts in the diabetic compared with the nondiabetic mice in all three groups at 2 wk after injection of the bacteria. Two weeks after injection of inocula containing B. fragilis, both in combination with E. coli or enterococcus, all nondiabetic mice had eradicated B. fragilis from the abscesses, but significant numbers of B. fragilis persisted in the abscesses of the diabetic mice. In the diabetic mice, the presence of enterococci was more synergistic for growth of B. fragilis than was the presence of E. coli. These studies demonstrate that the bacteria of polymicrobial soft tissue infections persist for a longer period of time in the diabetic compared with the nondiabetic host. In addition, B. fragilis has increased pathogenicity in the diabetic compared with the nondiabetic host, particularly in the presence of enterococci.

Fentanyl and alfentanil suppress brainstem pain transmission

The effects of intravenously administered fentanyl (25 micrograms/kg, n = 9; 50 micrograms/kg, n = 5) and alfentanil (12.5 micrograms/kg, n = 5; 25 micrograms/kg, n = 7) on the noxiously evoked, single-unit activity of cells in the nucleus reticularis gigantocellularis (NRGC) were studied in decerebrate cats. Only cells of the NRGC excited exclusively by supramaximal electrical stimulation of A delta fibers (noxious stimulation) of the superficial radial nerve were studied. The noxiously evoked activity of all cells in the NRGC was suppressed by the administration of opioids (by 58 and 88% for fentanyl, 25 micrograms/kg and 50 micrograms/kg, respectively; by 35 and 78% for alfentanil 12.5 micrograms/kg and 25 micrograms/kg, respectively). Fentanyl and alfentanil effects were antagonized by the intravenous administration of naloxone. These results indicate that opioid suppression of noxiously evoked activity is seen in neurons located in the brainstem, and thus suppression of brainstem neurons may be important in the production of fentanyl and alfentanil analgesia.

Effect of administration of estrogen to pregnant rabbits on the lipid content and composition of the fetal brain

Intramuscular injection of 17 beta-estradiol to pregnant rabbits did not produce any significant change in the phospholipid, neutral lipid and cholesterol content of the fetal brains, nor did it cause any significant difference in their wet and dry weights. It may be inferred that use of estrogen in the gestational period to enhance surfactant production and lung maturation in the fetus would not produce adverse effects on the fetal brain lipids.

Ureteral motility in sheep

Ureteral motility was studied in twenty-five sodium pentobarbital-anaesthetized sheep. Mean frequency of the peristaltic waves was 15 per min and the range was 11-19. Frequency was the same throughout the length of the ureter. Mean contraction pressure (cm H2O) was 40 in the upper ureter, 35 in the middle ureter and 31 in the lower ureter. Mean concentration time was 1 sec and range was 0.6-1.5. Mean relaxation time was 1.1 sec and range was 0.7-1.5. Diuresis induced by rapid intravenous administration of physiologic sodium chloride solution abolished the peristaltic activity.

Effects of saline extract of ovine hydatid cyst scoleces in sheep. Blockade of responses by compound 48/80

The effects of intravenous administration of the saline extract of the ovine hydatid cyst scoleces on the cardiovascular and respiratory systems were studied in sodium pentobarbital-anesthesized sheep. Scoleces were obtained from the lung hydatid cysts of freshly slaughtered sheep, sonicated in physiologic saline and centrifuged to recover the extract in the supernatant fluid. Administration of 1-4 ml of the saline extract resulted in hypotension, shallow rapid respiration, slight elevation of the central venous pressure and transient electrocardiographic changes. Pretreatment of the animals with atropine, 1 mg/kg S.C., or with the antihistamine antazoline, 5 mg/kg I.V., did not block the responses to the saline extract of hydatid cyst scoleces. Pretreatment with compound 48/80, a histamine releaser, abolished the reactions to the administration of the scoleces extract. It is concluded that ovine hydatid scoleces extract has profound cardiovascular and respiratory effects, and that histamine release seems to be involved in the induction of responses to the extract.

Effects of ovine hydatid cyst fluid in sheep before and after treatment with hydrocortisone, antihistamines and atropine

The cardiovascular and respiratory responses to scolex-free ovine hydatid cyst fluid were studied in 65 sodium pentobarbital-anesthetized sheep. The arterial blood pressure (ABP), central venous pressure (CVP), stethogram and electrocardiogram were recorded. Intra-venous administration of 10 ml or less hydatid fluid brought about moderate to severe fall in ABP and rapid respiration or permanent respiratory cessation in majority of the animals. Forty six percent of the sheep died of circulatory and respiratory failure after the first injection or the hydatid fluid. Boiled hydatid fluid did not lose its potency to evoke the above responses. Hydrocortisone, given 200 mg daily for seven days, failed to prevent the reactions to hydatid fluid. Intravenous administration of the antihistamines chlorpheniramine, 4 mg/kg, and antazoline, 5 mg/kg, caused only partial prevention of the responses in 8 out of 15 responsive sheep. Pretreatment of the animals with atropine, 0.5--1 mg/kg subcutaneously, did not block the reactions. The cardiovascular and respiratory responses to ovine hydatid fluid may be due to antigen-antibody reactions or some toxic component of the fluid.

Effect of electrical stimulation of the medullary respiratory neurons on respiratory air flow in cats. New findings on expiratory neurons

Respiratory air flow during electrical stimulation of the medullary respiratory neurons was measured in 25 sodium pentobarbital-anesthetized cats. The effect of variation of stimulus parameters on the air flow was studied too. The medullary respiratory neurons were localized by exploring the medulla with microelectrodes. The inspiratory neurons were found hetween 2 and 4 mm lateral to the midline, and from the level of the obex to 4 mm rostrally in the ventral reticular formation. The expiratory cells were between 2 and 3 mm lateral to the midline, extending from the level of the obex to 3 mm caudally, slightly less ventral than the inspiratory neurons. The maximal inspiratory and expiratory flow rates were 56 and 44 liters per minute respectively when the respiratory neurons were stimulated with a stimulus of 4 volts and 200 Hz/sec., while duration of the stimulating pulse was 0.5 millisecond. In general, the increase in air flow was proportional to the magnitude of the stimulus strength, stimulus frequency and duration of the stimulating pulse.