Increases in drug-related infant mortality in the United States

OBJECTIVES

We explored temporal trends in drug-related infant deaths in the United States (U.S.) from 2018 to 2022.

METHODS

We used data from the Centers for Disease Control and Prevention Wide-ranging Online Data for Epidemiologic Research (WONDER). A total of 295 drug-involved infant deaths were identified from 2018 to 2022 (provisional mortality data for year 2022) based on the underlying cause of death.

RESULTS

In the U.S. from 2018 to 2022, there was a significant 2.2-fold increase in drug-involved infant mortality. The observed increases were higher in non-Hispanic White and Black infants. The findings show that drug-involved infant deaths were more likely to occur in the postneonatal period, defined as ages 28-364 days (81.4 %) compared to the neonatal period. The most prevalent underlying causes of death included assault (homicide) by drugs, medicaments and biological substances (35.6 %) followed by poisoning due to exposure to narcotics and psychodysleptics (hallucinogens) (15.6 %). The most common multiple causes of drug-involved infant deaths were psychostimulants with abuse potential of synthetic narcotics.

CONCLUSIONS

Drug-related infant mortality has increased significantly from 2018 to 2022. These increases are particularly evident among White and Black infants and occurred predominantly in the postneonatal period. These findings require more research but also indicate the need to address drug-involved infant deaths as preventable clinical and public health issues. Effective strategies to reduce drug-involved infant deaths will require preventing and treating maternal substance use disorders, enhancing prenatal care access, and addressing broader social and behavioral risk factors among vulnerable maternal and infant populations.

Promoting Artificial Intelligence for Global Breast Cancer Risk Prediction and Screening in Adult Women: A Scoping Review

Background: Artificial intelligence (AI) algorithms can be applied in breast cancer risk prediction and prevention by using patient history, scans, imaging information, and analysis of specific genes for cancer classification to reduce overdiagnosis and overtreatment. This scoping review aimed to identify the barriers encountered in applying innovative AI techniques and models in developing breast cancer risk prediction scores and promoting screening behaviors among adult females. Findings may inform and guide future global recommendations for AI application in breast cancer prevention and care for female populations. Methods: The PRISMA-SCR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) was used as a reference checklist throughout this study. The Arksey and O'Malley methodology was used as a framework to guide this review. The framework methodology consisted of five steps: (1) Identify research questions; (2) Search for relevant studies; (3) Selection of studies relevant to the research questions; (4) Chart the data; (5) Collate, summarize, and report the results. Results: In the field of breast cancer risk detection and prevention, the following AI techniques and models have been applied: Machine and Deep Learning Model (ML-DL model) (n = 1), Academic Algorithms (n = 2), Breast Cancer Surveillance Consortium (BCSC), Clinical 5-Year Risk Prediction Model (n = 2), deep-learning computer vision AI algorithms (n = 2), AI-based thermal imaging solution (Thermalytix) (n = 1), RealRisks (n = 2), Breast Cancer Risk NAVIgation (n = 1), MammoRisk (ML-Based Tool) (n = 1), Various MLModels (n = 1), and various machine/deep learning, decision aids, and commercial algorithms (n = 7). In the 11 included studies, a total of 39 barriers to AI applications in breast cancer risk prediction and screening efforts were identified. The most common barriers in the application of innovative AI tools for breast cancer prediction and improved screening rates included lack of external validity and limited generalizability (n = 6), as AI was used in studies with either a small sample size or datasets with missing data. Many studies (n = 5) also encountered selection bias due to exclusion of certain populations based on characteristics such as race/ethnicity, family history, or past medical history. Several recommendations for future research should be considered. AI models need to include a broader spectrum and more complete predictive variables for risk assessment. Investigating long-term outcomes with improved follow-up periods is critical to assess the impacts of AI on clinical decisions beyond just the immediate outcomes. Utilizing AI to improve communication strategies at both a local and organizational level can assist in informed decision-making and compliance, especially in populations with limited literacy levels. Conclusions: The use of AI in patient education and as an adjunctive tool for providers is still early in its incorporation, and future research should explore the implementation of AI-driven resources to enhance understanding and decision-making regarding breast cancer screening, especially in vulnerable populations with limited literacy.

Digital Health Interventions for Cancer Prevention Among Racial and Ethnic Minority Groups in the United States: A Scoping Review

OBJECTIVE

The COVID-19 pandemic abruptly accelerated the use of digital health for cancer care. Previously, researchers identified a variety of digital health interventions for cancer prevention. The purpose of the present scoping review was to identify digital health interventions for cancer prevention designed for racial/ethnic minority groups.

METHODS

The scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews and was guided by the Arksey and O'Malley methodological framework. A search of PubMed, Ovid MEDLINE, and CINAHL for peer-reviewed research articles published from database inception to August 21, 2023, was conducted. Peer-reviewed studies published in English that employed digital health interventions for cancer prevention, that were conducted among racial/ethnic minority groups, and that were conducted in the United States were included. Also included were cancer prevention interventions for people who did not have cancer, people who did have cancer, and cancer survivors. Excluded were interventions that included non-Hispanic White individuals, interventions performed outside the United States, interventions that combined face-to-face methods with digital strategies, and interventions that did not clearly include digital health. Articles that focused on technologies for collecting and transmitting health data (e.g., remote patient monitoring) without an explicit tie-in to cancer prevention intervention outcomes were also excluded.

RESULTS

Following screening, eight articles met the eligibility criteria. Six of the articles were published prior to the COVID-19 pandemic, and two were published during it. The digital health interventions for cancer prevention in racial/ethnic minority groups included screening (n = 5), emotional support and education (n = 1), human papillomavirus vaccination (n = 1), and education and treatment (n = 1). A consistently measured outcome was intervention efficacy. Four authors explicitly stated that theories or theoretical constructs were employed to guide intervention development. Also, no interventions were created using novel devices such as emerging technologies.

CONCLUSIONS

We identified several notable gaps regarding digital health for cancer prevention among racial/ethnic minority groups. Addressing these gaps may help guide continued innovation in the use of digital health for cancer prevention among racial/ethnic minority groups.

Perception of Risk of Harm from Cannabis Use Among Women of Reproductive Age with Disabilities

Objectives: To examine perceived risk of harm from weekly cannabis use among reproductive-aged women with disabilities. Methods: Using data from the 2021 National Survey on Drug Use and Health, we assessed perceived risk of harm associated with weekly cannabis use among women of reproductive age by disability status. Disabilities included sensory, cognitive, and those related to daily activities. Logistic regression was employed to examine correlates of risk perception associated with weekly cannabis in this subpopulation of women. Results: A significantly higher percentage of women with any disability perceived no risk associated with weekly cannabis use (37.9%) compared to those with no disabilities (26.1%). Approximately, 60.0% of women with disabilities who used cannabis in the past 12 months perceived no risk of harm from weekly cannabis use. Overall, women with disabilities and cannabis use in the past 12 months had higher adjusted odds (AOR=2.90, 95% CI=2.10-4.10) of perceiving no risk associated with weekly use of cannabis compared to women without any disability and no cannabis use. Other significant factors associated with an increased likelihood of perceiving no risk of harm from weekly use of cannabis included younger women, having higher income, being in good health, and using alcohol or tobacco. Conclusions: Perceived risk of harm associated with weekly cannabis use is particularly low among women with disabilities who use cannabis. Given current attitudes toward cannabis as a harmless drug, and the potential adverse health outcomes, it is imperative to monitor and understand women's perceptions of risk of harm from cannabis use for clinical guidance, provider and patient education, and public health programs to support evidence-based approaches in addressing its use among vulnerable populations such as those of reproductive age with disabilities.

Assessment of the social quality of life and the physical activity of adult celiac disease patients following a gluten-free diet in Lebanon

To date, the primary and only treatment recommended for effective management of celiac disease (CD) is adherence to a strict gluten-free diet (GFD) which entails a new approach to eating that affects the social quality of life (QoL) and physical activity (PA) of patients. This cross-sectional study aimed at assessing the social QoL and PA of adult Lebanese CD patients aged between 18 and 59 years old who are following a GFD. An online CD questionnaire was administered to 136 Lebanese celiac participants on a GFD. The findings of this study show a significant association between celiac patients following a GFD and their social QoL (P-value = 0.0001). The results also showed a significant association between the same population and their PA (p-value = 0.0001). Further awareness-raising and learning activities about gluten-free products are needed to improve the adherence to a strict GFD to facilitate its availability to the Lebanese population.

Social determinants of health and health inequities in breast cancer screening: a scoping review

Introduction

This scoping review aims to highlight key social determinants of health associated with breast cancer screening behavior in United States women aged ≥40  years old, identify public and private databases with SDOH data at city, state, and national levels, and share lessons learned from United States based observational studies in addressing SDOH in underserved women influencing breast cancer screening behaviors.

Methods

The Arksey and O'Malley York methodology was used as guidance for this review: (1) identifying research questions; (2) searching for relevant studies; (3) selecting studies relevant to the research questions; (4) charting the data; and (5) collating, summarizing, and reporting results.

Results

The 72 included studies were published between 2013 and 2023. Among the various SDOH identified, those related to socioeconomic status (n = 96) exhibited the highest frequency. The Health Care Access and Quality category was reported in the highest number of studies (n = 44; 61%), showing its statistical significance in relation to access to mammography. Insurance status was the most reported sub-categorical factor of Health Care Access and Quality.

Discussion

Results may inform future evidence-based interventions aiming to address the underlying factors contributing to low screening rates for breast cancer in the United States.

Corrigendum: Editorial: Period poverty

[This corrects the article DOI: 10.3389/frph.2023.1140981.].

Using Patient-Centered Dissemination and Implementation Frameworks and Strategies in Palliative Care Settings for Improved Quality of Life and Health Outcomes: A Scoping Review

BACKGROUND

There is a need for patient-provider dissemination and implementation frameworks, strategies, and protocols in palliative care settings for a holistic approach when it comes to addressing pain and other distressing symptoms affecting the quality of life, function, and independence of patients with chronic illnesses. The purpose of this scoping review is to explore patient-centered D&I frameworks and strategies that have been adopted in PC settings to improve behavioral and environmental determinants influencing health outcomes through evidence-based programs and protocols.

METHODS

The five step Arksey and O'Malley's (2005) York methodology was adopted as a guiding framework: (1) identifying research questions; (2) searching for relevant studies; (3) selecting studies relevant to the research questions; (4) charting the data; and (5) collating, summarizing, and reporting results.

RESULTS

Only 6 out of the 38 (16%) included studies applied a D&I theory and/or framework. The RE-AIM framework was the most prominently cited (n = 3), followed by the Diffusion of Innovation Model (n = 2), the CONNECT framework (n = 1), and the Transtheoretical Stages of Change Model (n = 1). The most frequently reported ERIC strategy was strategy #6 "Develop and organize quality monitoring systems", as it identified in all 38 of the included studies.

CONCLUSION

This scoping review identifies D&I efforts to translate research into practice in U.S. palliative care settings. Results may contribute to enhancing future D&I initiatives for dissemination/adaptation, implementation, and sustainability efforts aiming to improve patient health outcomes and personal satisfaction with care received.

Prevalence of Cosmetic Procedures among Lebanese Women

Lebanese women have been portrayed as conceited and obsessed with physical appearance and its beautification through cosmetic procedures. Despite the pervasiveness of this notion, no formal studies have been conducted to assess the true prevalence of cosmetic procedures among Lebanese women. Additionally, no data exist to elucidate trends in popularity of cosmetic procedures over time. A cross-sectional study was conducted across Lebanese universities where surveys were distributed to women aged 18-31 years to estimate the prevalence of surgical, noninvasive, and dental cosmetic procedures in young Lebanese women. The collected survey data were analyzed using the Statistical Package for the Social Sciences (SPSS). In a sample of 877 women, 44% reported having undergone at least one cosmetic procedure in their lifetime. The most popular procedures performed were laser hair removal (32%), teeth whitening (14%), and rhinoplasty (9.3%). The obtained results revealed an increasing prevalence of cosmetic procedures, mirroring global trends. A variety of factors have contributed to the increasing popularity of cosmetic procedures, namely, higher availability, better affordability, and wider social acceptance over time. (SKINmed. 2022;20:422-427).

The Healthy Native Youth Implementation Toolbox: Using Implementation Mapping to adapt an online decision support system to promote culturally-relevant sexual health education for American Indian and Alaska Native youth

Background

American Indian and Alaska Native (AI/AN) youth experience serious disparities in sexual and reproductive health, including the highest teen birth rate among racial/ethnic groups, and disproportionate rates of sexually transmitted infections (STI), including HIV. A growing number of evidence-based programs (EBPs) that integrate the strengths and cultural teachings of Native communities exist. Yet, multiple factors, including lack of trained personnel, limited resources, and geographic isolation, may hinder their adoption and implementation. Innovative implementation strategies that facilitate the adoption and implementation of sexual health EBPs in Native communities may help reduce these disparities.

Methods

We applied Implementation Mapping, a systematic planning framework that utilizes theory, empirical evidence, and community input, to adapt a theory-based, online decision support system, iCHAMPSS (CHoosing And Maintaining Effective Programs for Sex Education in Schools), to support underlying dissemination and implementation processes unique to Native communities. We used an iterative design process, incorporating input from Native practitioners and academicians, to ensure that the adapted decision support system reflects cultural identification, community values, and experiences.

Results

Grounded in diffusion of innovations, organizational stage theory, and social cognitive theory, the Healthy Native Youth Implementation Toolbox supports Native practitioners through five phases (Gather, Choose, Prepare, Implement, and Grow) to adopt, implement, and maintain a culturally-relevant, age-appropriate sexual health EBP. The Toolbox provides tools, ready-to-use templates, and guidance to plan, implement, and grow a culturally-relevant adolescent health program with their Tribe or community. Hosted within the Healthy Native Youth website (www.healthynativeyouth.org), the Toolbox comprises: (1) a curriculum portal with access to 15 culturally-relevant, age-appropriate evidence-based health promotion programs for AI/AN youth; (2) a "resource library" comprising 20+ support tools, templates, and links to external resources, and (3) "stories from the field" comprising testimonials from experienced Native educators, who have implemented sexual health programs.

Conclusion

There is a continued need to design, test, and evaluate D&I strategies that are relevant to Native communities. The Healthy Native Youth Implementation Toolbox contributes to the dissemination and implementation of evidence-based, culturally-relevant sexual health education programs in diverse Native communities. Implementation Mapping provided a systematic approach to guide the adaptation process and integrate community voice with the ultimate goal of enhancing sexual health equity among AI/AN youth.

Addressing Food Insecurity during the COVID-19 Pandemic: Intervention Outcomes and Lessons Learned from a Collaborative Food Delivery Response in South Florida’s Underserved Households

Background: The COVID-19 pandemic highlighted underlying disparities in health, healthcare access, and other social factors that have been documented for racial/ethnic minorities. The social-distancing mandate exacerbated the impact of social determinants of health, such as unemployment and food insecurity, particularly among underserved minority populations. We highlight intervention outcomes and lessons learned from the Florida International University (FIU) Herbert Wertheim College of Medicine (HWCOM) NeighborhoodHELP’s response to pandemic-related food insecurity among Miami Dade County’s underserved population. Methods: Following the stay-at-home mandate, a weekly needs assessment of program households was conducted by the NeighborhoodHELP team, during which food insecurity emerged as a pandemic-related urgent need, rising from three percent of program Households in March 2020 to 36.9 percent six months later. Consequently, the program staff collaborated with another FIU department, community partners, and a benefactor to develop a food donation and delivery project. Results: Fifteen hundred and forty-three culturally appropriate food boxes were delivered to 289 participating households, comprising 898 household members, over a 14-month period. Conclusion: This project underscores the importance of leveraging community assets to address their needs during a crisis and the significance of sustained community engagement for researchers and service providers who work in underserved communities.

The Impact of COVID-19 on the Delivery of Educational Programs in Native American Communities: Qualitative Study

Background

Despite the availability of culturally responsive sexual health educational programs for American Indian and Alaska Native (AI/AN) youth, barriers to their uptake and utilization persist in tribal communities. These challenges were exacerbated by the COVID-19 pandemic, which required flexible program delivery using both in-person and virtual classrooms.

Objective

This exploratory study provides a preliminary understanding of the extent to which pre-existing challenges impact the delivery of culturally responsive sexual health education programs in Native communities and to what extent they were exacerbated by the COVID-19 pandemic. It also highlights the challenges faced by adolescent health advocates when adapting culturally responsive health curricula to online platforms. Finally, this study discloses major socioeconomic, health, and mental challenges experienced by AI/AN youth during the pandemic.

Methods

An exploratory, descriptive, qualitative design approach was adopted to carry out 5 individual and 1 collective in-depth key informant interviews. A total of 8 Native and non-Native sexual health educators served as key informants and shared their personal experiences with the delivery of sexual health education programs for youth during the COVID-19 pandemic. The interviews were conducted virtually from October to November 2020 using Zoom to reach participants dispersed across different regions of the United States. We followed the consolidated criteria for reporting qualitative research (COREQ) as a reference for the study methodology. We also used the Braun and Clarke framework (2006) to conduct a thematic analysis.

Results

Experts’ opinions were structured according to 5 main themes: (1) competing community priorities during COVID-19; (2) moving to web-based programming: skills, training, support; (3) recruiting youth; and (4) challenges for implementation in a household environment; and (5) recommendations to overcome implementation challenges. These themes are complementary, connected, and should be considered holistically for the development, dissemination, and implementation of online sexual health programs for AI/AN youth, specifically during the COVID-19 pandemic. The results raised the following points for discussion: (1) Building partnerships with schools and community organizations facilitates program adaptation and implementation, (2) there is a need to adopt a holistic approach when addressing youth sexual health in AI/AN communities, (3) a systematic and culturally responsive adaptation approach ensures effective virtual program delivery, and (4) community and youth engagement is essential for the success of virtual sexual health programs.

Conclusions

Findings can provide recommendations on actions to be taken by sexual health educators and guidelines to follow to ensure cultural sensitivity, effective adaptation, and successful implementation when setting out to advocate for online sexual health programs for AI/AN youth.

Barriers, frameworks, and mitigating strategies influencing the dissemination and implementation of health promotion interventions in indigenous communities: a scoping review

BACKGROUND

Many Indigenous communities across the USA and Canada experience a disproportionate burden of health disparities. Effective programs and interventions are essential to build protective skills for different age groups to improve health outcomes. Understanding the relevant barriers and facilitators to the successful dissemination, implementation, and retention of evidence-based interventions and/or evidence-informed programs in Indigenous communities can help guide their dissemination.

PURPOSE

To identify common barriers to dissemination and implementation (D&I) and effective mitigating frameworks and strategies used to successfully disseminate and implement evidence-based interventions and/or evidence-informed programs in American Indian/Alaska Native (AI/AN), Native Hawaiian/Pacific Islander (NH/PI), and Canadian Indigenous communities.

METHODS

A scoping review, informed by the York methodology, comprised five steps: (1) identification of the research questions; (2) searching for relevant studies; (3) selection of studies relevant to the research questions; (4) data charting; and (5) collation, summarization, and reporting of results. The established D&I SISTER strategy taxonomy provided criteria for categorizing reported strategies.

RESULTS

Candidate studies that met inclusion/exclusion criteria were extracted from PubMed (n = 19), Embase (n = 18), and Scopus (n = 1). Seventeen studies were excluded following full review resulting in 21 included studies. The most frequently cited category of barriers was "Social Determinants of Health in Communities." Forty-three percent of barriers were categorized in this community/society-policy level of the SEM and most studies (n = 12, 57%) cited this category. Sixteen studies (76%) used a D&I framework or model (mainly CBPR) to disseminate and implement health promotion evidence-based programs in Indigenous communities. Most highly ranked strategies (80%) corresponded with those previously identified as "important" and "feasible" for D&I The most commonly reported SISTER strategy was "Build partnerships (i.e., coalitions) to support implementation" (86%).

CONCLUSION

D&I frameworks and strategies are increasingly cited as informing the adoption, implementation, and sustainability of evidence-based programs within Indigenous communities. This study contributes towards identifying barriers and effective D&I frameworks and strategies critical to improving reach and sustainability of evidence-based programs in Indigenous communities.

REGISTRATION NUMBER

N/A (scoping review).

Assessment of the Reach, Usability, and Perceived Impact of "Talking Is Power": A Parental Sexual Health Text-Messaging Service and Web-Based Resource to Empower Sensitive Conversations with American Indian and Alaska Native Teens

BACKGROUND

Early sexual debut among American Indian and Alaska Native (AI/AN) adolescents has been associated with an increased risk of teenage pregnancies and sexually transmitted infections, along with an increased risk of having multiple lifetime sexual partners, and engaging in greater frequency of sex, substance abuse, and lack of condom use. A major protective factor against early sexual debut among AI/AN youth is the familial system. Interventions aiming to improve parent-child communication and parental warmth toward adolescent sexual health topics were reported to contribute to positive youth sexual health outcomes, specifically among minority youth. Healthy Native Youth thus developed the Talking is Power text-messaging service to guide parents and caring adults on how to initiate sensitive topics with youth and how to support them in making informed decisions regarding sex and healthy relationships.

METHODS

Descriptive statistics were used to demonstrate website analytics and reach per views and time spent on each page, and for displaying participants' responses to the questions on the usability of the Talking is Power text-messaging series. To assess the perceived impact of the series, the differences in mean percentage scores of the question assessing parental comfort in engaging in sexual health topics with youth between pre- and post-intervention were calculated using two-sample t-tests of equal variances. Descriptive content analysis was adopted to highlight emerging themes from open-ended items.

RESULTS

When looking at reach, 862 entrances were recorded during the specified time period (5.8% of total entrances to HNY website), while the bounce rate was set at 73.1% (22.6% greater than the industry average), and the exit rate was 54.3% (15.2% greater than the industry average). Series usability was highly ranked on the 5-Likert scale in terms of signing up for a similar series on a different topic, quality of images, texts, and links, relating to prompts, and change in sparking sensitive conversations with youth. High likelihood of recommending the series to a friend or colleague was also reported by participants (0-10). No significant difference in parental comfort levels was reported (p = 0.78 > 0.05). Main themes provided suggestions for improving the series mode of delivery, while others included positive feedback about the material, with the possibility of expanding the series to other adolescent health topics.

CONCLUSION

Lessons learned during the design, dissemination, and evaluation of the resource's usability, reach, and perceived impact may be of interest to other Indigenous communities who are in the process of adapting and/or implementing similar approaches.

Predictors of high trust and the role of confidence levels in seeking cancer-related information

One of the most commonly searched topics on the internet in the United States is cancer. Our study aims to provide a general overview of the predictors of trust for two health information sources, doctors and the internet, when seeking cancer-related information. The data were obtained from the 2018 HINTS 5 Cycle 2 survey, which was administered from January through May to a total of 3,504 respondents. We carried out next a series of ordinal logistic regression models to identify predictors of high trust in doctors and the internet separately for cancer-seeking information. Demographic predictor variables varied as predictors of high trust for cancer knowledge across both sources. Respondents who reported less confidence in their ability to seek cancer information had significantly higher odds of high trust in both doctors (OR = 8.43, CI: 5.58-12.73) and the internet (OR = 2.93, CI: 1.97-4.35) as compared to those who reported being "completely confident" in their ability to obtain cancer information. Understanding the key predictors of trust in doctors and the internet is crucial to the enhancement of health. The role of confidence as a predictor of trust in seeking cancer information has been shown to consistently influence the levels of trust attributed to each topic.

Using Intervention Mapping to Develop Health Education and Health Policy Components to Increase Breast Cancer Screening and Chemotherapy Adherence Among Syrian and Iraqi Refugee Women in Beirut, Lebanon

Introduction: Despite the continuous increase in the incidence of metastatic breast cancer among Syrian and Iraqi refugee women residing in camp settings in Lebanon, mammography and chemotherapy adherence rates remain low due to multiple social, economic, and environmental interfering factors. This in turn led to an alarming increase in breast cancer morbidity and mortality rates among the disadvantaged population. Methods: Intervention mapping, a systematic approach which guides researchers and public health experts in the development of comprehensive evidence-based interventions (EBIs) was used to plan a health education and health policy intervention to increase breast cancer screening and chemotherapy adherence among Iraqi and Syrian refugee women aged 30 and older who are residing in refugee camps within the Beirut district of Lebanon. Results: The generation of the logic model during the needs assessment phase was guided by an extensive review of the literature and reports published in peer-reviewed journals or by international/local organizations in the country to determine breast cancer incidence and mortality rates among refugee women of Syrian and Iraqi nationalities. The underlying behavioral and environmental determinants of the disease were identified from qualitative and quantitative studies carried out among the target population and also aided in assessing the sub-behaviors related to the determinants of breast cancer screening and chemotherapy completion as well as factors affecting policy execution to formulate performance objectives. We then developed matrices of change objectives and their respective methods and practical applications for behavior change at the intrapersonal, interpersonal, organizational, and societal levels. Both educational components (brochures, flyers) and technological methods (videos disseminated via Whats app and Facebook) will be adopted to apply the different methods selected (modeling, self-reevaluation, consciousness raising, persuasion, and tailoring). We also described the development of the educational and technological tools, in addition to providing future implementers with methods for pre-testing and pilot-testing of individual and environmental prototype components. Conclusion: The use of intervention mapping in the planning and implementation of holistic health promotion interventions based on information collected from published literature, case reports, and theory can integrate the multiple disciplines of public health to attain the desired behavioral change.

Detection of growth hormone abuse in sport

OBJECTIVE

To develop a test for GH abuse in sport.

DESIGN

A double blind placebo controlled study of one month's GH administration to 102 healthy non-competing but trained subjects. Blood levels of nine markers of GH action were measured throughout the study and for 56 days after cessation of GH administration. Blood samples were also taken from 813 elite athletes both in and out of competition.

RESULTS

GH caused a significant change in the nine measured blood markers. Men were more sensitive to the effects of GH than women. IGF-I and N-terminal extension peptide of procollagen type III were selected to construct formulae which gave optimal discrimination between the GH and placebo groups. Adjustments were made to account for the fall in IGF-I and P-III-P with age and the altered distribution seen in elite athletes. Using a cut-off specificity of 1:10,000 these formulae would allow the detection of up to 86% of men and 60% of women abusing GH at the doses used in this study.

CONCLUSIONS

We report a methodology that will allow the detection of GH abuse. This will provide the basis of a robust and enforceable test identifying those who are already cheating and provide a deterrent to those who may be tempted to do so.

The effect of four weeks of supraphysiological growth hormone administration on the insulin-like growth factor axis in women and men. GH-2000 Study Group

Measurements of serum insulin-like growth factor I (IGF-I) and related markers are routinely used in the diagnosis and treatment of GH deficiency and excess. The validity of these markers for assessment of exogenous GH exposure in healthy adults is, however, unknown. We therefore conducted a double blind, placebo-controlled GH treatment trial in 99 healthy subjects [49 women and 50 men; mean +/- SE age, 25.6+/-0.6 (women)/25.7+/-0.6 yr (men)]. Blood was collected weekly during a 4-week treatment period (days 1-28), and the subjects were subsequently followed for additional 8 weeks (days 29-84). The treatment arms included: I) 0.1 IU/kg x day GH (n = 30; GH 0.1), II) 0.2 IU/kg x day GH (n = 29; GH 0.2), and III) placebo (n = 40). At baseline no gender-specific differences existed, except that the acid-labile subunit (ALS) levels were higher in females. Serum insulin-like growth factor I (IGF-I) levels in males receiving GH increased significantly through day 42 with no significant difference between the 2 doses. The absolute IGF-I response was significantly lower in females, and there was a clear dose-response relationship. ALS levels in males increased through day 30 (P < 0.001). In females ALS levels were only modestly increased on day 28 compared with those in the placebo group (P < 0.02). IGF-binding protein-3 (IGFBP-3) levels in males increased significantly in the GH 0.1 and the GH 0.2 groups on day 30 (P < 0.03), whereas no solid IGFBP-3 increase was detected in females. IGFBP-2 levels decreased insignificantly during GH exposure in both genders. A gender-specific upper normal range for each analyte was arbitrarily defined as 4 SD above the mean level at baseline. On the basis of IGF-I levels alone, GH exposure in the GH 0.2 group was detected in 86% of the males and in 50% of the females on day 21. On day 42 GH exposure was only weakly detectable in males and was not detectable in females. We conclude that 1) males are significantly more responsive than females to exogenous GH; 2) the increase in IGF-I is more robust compared with those in IGFBP-3 and ALS; 3) IGFBP-2 changes very little during GH treatment; and 4) among IGF-related substances, IGF-I is the most specific marker of supraphysiological GH exposure.

Responses of markers of bone and collagen turnover to exercise, growth hormone (GH) administration, and GH withdrawal in trained adult males

To examine the interactions between acute exercise and GH on markers of bone and collagen turnover and to assess the potential for detecting GH abuse in athletes using these markers, we studied 17 aerobically trained males (age, 26.9+/-1.5 yr). Sequential studies of exercise, GH administration, and GH withdrawal were undertaken. A randomized, controlled study of rest vs. exercise showed that exercise did not change serum osteocalcin; other markers of formation increased transiently (each P<0.001): bone-specific alkaline phosphatase (+16.1%), carboxyterminal propeptide of type I procollagen (+14.1%), and procollagen III N-terminal extension peptide (+5.0%). The carboxyterminal cross-linked telopeptide of type I collagen, a bone resorption marker, increased 9.7% (P = 0.018) in response to exercise. A randomized, double blind, placebo-controlled, parallel study of recombinant human GH treatment (0.15 IU/kg x day) for 1 week increased serum osteocalcin (net increase preexercise, +/-10.0%; P = 0.017), carboxyterminal propeptide of type I procollagen (+17.6%; P = 0.002), procollagen III N-terminal extension peptide (+48.4%; P = 0.001), and carboxyterminal cross-linked telopeptide of type I collagen (53.3%; P = 0.009). Disappearance half-times after cessation of recombinant human GH for pre- and postexercise markers ranged from 248-770 h. We conclude 1) endurance exercise transiently activates bone and collagen turnover; 2) brief GH administration results in similar but quantitatively greater augmentation; and 3) these data will assist in designing a GH detection strategy.

Responses of the growth hormone (GH) and insulin-like growth factor axis to exercise, GH administration, and GH withdrawal in trained adult males: a potential test for GH abuse in sport

GH abuse by elite athletes is currently undetectable. To define suitable markers of GH doping, we assessed the effects of acute exercise, GH administration, and GH withdrawal on the GH/insulin-like growth factor (IGF) axis in athletic adult males. Acute endurance-type exercise increased serum GH, GH-binding protein (GHBP), total IGF-I, IGF-binding protein (IGFBP)-3, and acid-labile subunit (ALS), each peaking at the end of exercise. IGFBP-1 increased after exercise was completed. Free IGF-I did not change with exercise. Recombinant human GH treatment (0.15 IU/kg x day) for 1 week increased serum total IGF-I, IGFBP-3, and ALS, exaggerating the responses to exercise. IGFBP-2 and IGFBP-1 were trivially suppressed. After GH withdrawal, the GH response to identical exercise was suppressed. Total IGF-I, IGFBP-3, and ALS returned to baseline over 3-4 days. In summary, 1) acute exercise transiently increased all components of the IGF-I ternary complex, possibly due to mobilization of preformed intact complexes; 2) GH pretreatment augmented the exercise-induced changes in ternary complexes; 3) postexercise IGFBP-1 increments may protect against delayed onset hypoglycemia; 4) serum total IGF-I, IGFBP-3, and ALS may be suitable markers of GH abuse; and 5) differences in disappearance times altered the sensitivity of each marker for detecting GH abuse.

Cardiovascular aspects in acromegaly: effects of treatment

Patients with acromegaly have significant morbidity and mortality, associated with cardiovascular disease. Acromegaly is often complicated by other diseases such as diabetes mellitus, hypertension, and coronary artery disease, so the existence of acromegalic cardiomyopathy remains uncertain. Cardiac performance was investigated in patients with uncomplicated acromegaly. A subgroup of hypertensive acromegalics was also studied. In addition, the effects of chronic octreotide therapy or surgery on cardiac structure and function in acromegaly were studied. Twenty-six patients and 15 healthy controls underwent gated blood-pool cardiac scintigraphy and echocardiography at rest and during exercise. Echocardiography was repeated after 6 months of octreotide therapy (n = 11). Cardiac scintigraphy was repeated after 12 and 24 months of octreotide therapy (n = 10) or 12 to 24 months after surgery (n = 8). ECG, blood pressure, and heart rate were monitored during cardiac scintigraphy. Left ventricular mass (LVM) was calculated from the findings of the echocardiography. Serum growth hormone (GH) levels and plasma insulin-like growth factor-1 (IGF-1) levels were monitored. LVM index was significantly higher (P < .003) in acromegalics than controls and in hypertensive acromegalics than normotensives, but all other indices of cardiac function were similar. Chronic octreotide decreased GH and IGF-1 levels and improved the structural abnormalities as measured by echocardiography. Chronic octreotide or surgery did not alter cardiac function parameters. Thus, important changes in cardiac structure and function occur in uncomplicated acromegaly, and improvements can be demonstrated after chronic octreotide therapy. Heart disease in acromegaly appears to be secondary to high circulating GH levels.

Effects of epinephrine on human muscle glucose and protein metabolism

Systemic epinephrine infusion causes hypoaminoacidemia and inhibits whole body leucine flux (proteolysis) in humans. Its specific action on muscle protein is not known and is difficult to assess during systemic epinephrine infusions, which affect plasma insulin, amino acid, and free fatty acid concentrations. During a steady-state infusion of L-[ring-2,6-3H]phenylalanine, we examined the effect of locally infused epinephrine on the metabolism of protein and glucose in forearm muscle of 10 healthy human volunteers. During local epinephrine infusion, systemic concentrations of glucose, phenylalanine, insulin, and epinephrine were unchanged and lactate declined (P < 0.02). Compared with baseline, epinephrine induced significant increases in forearm blood flow (P < 0.01) and net lactate release (P < 0.001) and a decrease in glucose uptake (P < 0.01) at both 2 and 4 h. At 2 and 4 h phenylalanine release from muscle proteolysis was suppressed (P < 0.01), and at 4 h the net phenylalanine balance was less negative than baseline (P < 0.02), indicating an anticatabolic effect on muscle protein. We conclude that in human forearm muscle epinephrine, at physiological concentrations, has a catabolic effect on muscle glycogen but an anticatabolic action on muscle protein. The mechanism of this latter effect is not known.

Kinetic analysis of glycogen synthase and PDC in cirrhotic rat liver and skeletal muscle

Glycogen synthase (GS) and pyruvate dehydrogenase complex (PDC) were kinetically analyzed in the liver and skeletal muscle of fasted and refed rats with thioacetamide-induced cirrhosis of the liver. In control rats, refeeding induced a 54% decrease in the A0.5 for glucose 6-phosphate (G-6-P) of hepatic GS (P < 0.001), reflecting allosteric activation of the enzyme. In skeletal muscle the A0.5 for G-6-P did not change after refeeding, whereas the activity ratio increased by 56% (P < 0.01), indicating a greater percentage of the active G-6-P-independent form of the enzyme. In cirrhotic rats, neither the A0.5 for G-6-P of liver GS nor the activity ratio of muscle GS was influenced by refeeding. Consequently, glycogen replenishment was significantly impaired both in the liver (2.56 +/- 0.2 vs. 5.11 +/- 0.4 g/100 g; P < 0.001) and skeletal muscle (0.45 +/- 0.01 vs. 0.52 +/- 0.02 g/100 g; P < 0.01). Refeeding increased the percentage of the active form of hepatic PDC both in control (+88%; P < 0.01) and cirrhotic rats (+91%; P < 0.001). In the latter, however, the rates of total and active PDC were significantly lower than in controls [-44% and -40% in fasted (P < 0.005) and refed (P < 0.005) rats, respectively]. Muscle PDC kinetics (both maximal velocity and Michaelis constant) and the percent active form were identical in cirrhotic and control rats, regardless of the nutritional state.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet aggregability in patients with a VVI pacemaker

Several studies have suggested an increased incidence of thromboembolic events in patients with VVI pacemaker (VVI patients); furthermore, other authors have demonstrated that a treatment with anticoagulants or antiplatelet drugs may be effective in reducing thromboembolic events, thus suggesting an increased formation of platelet thrombi in these patients. In this respect, platelet aggregability was investigated in ten VVI patients and ten age- and sex-matched subjects. beta-thromboglobulin (beta-Tg) and platelet factor 4 (PF4) plasma levels were determined as well as platelet aggregation induced by ADP, collagen, epinephrine, and arachidonic acid. Plasma beta-Tg levels were increased in the patient group (86 +/- 24 vs 24 +/- 13 ng/mL; P < 0.001) in presence of normal PF4 values (14 +/- 11 vs 13 +/- 6 ng/mL; NS). Aggregation curves showed abnormal values of maximal amplitude, slope, and lag time. In particular, maximal amplitude was significantly higher in VVI patients as compared with controls (ADP P < 0.01, collagen P < 0.001, adrenaline P < 0.01, arachidonic acid P < 0.05). These findings strongly suggest an increase of platelet activity in VVI patients.

Efficacy of ticlopidine in the prevention of thromboembolic events in patients with VVI pacemakers

This study was designed to evaluate whether long-term treatment with ticlopidine reduces the incidence of thromboembolic episodes in patients with a VVI pacemaker. One hundred eleven patients with a VVI pacemaker were randomly assigned to two groups: group A (52 patients) was treated with ticlopidine at the dose of 250 mg a day; and group B (59 patients) was not treated and served as a control group. The primary analysis of efficacy of ticlopidine was based on the occurrence of thromboembolic episodes and of cardiovascular and cerebrovascular deaths. The mean follow-up period was 66 months. In group A, there was a significant reduction in the incidence of thromboembolic episodes (P less than 0.05) with a smaller incidence of total cardiovascular and cerebrovascular deaths (8 in group A and 18 in group B; P = 0.05) as compared with group B. Twelve percent of patients had moderate side effects with 1 dropout (epistaxis). Our data confirm the high incidence of thromboembolic events in patients with a VVI pacemaker and demonstrate the efficacy of ticlopidine in preventing them.

Quantitation of forearm glucose and free fatty acid (FFA) disposal in normal subjects and type II diabetic patients: evidence against an essential role for FFA in the pathogenesis of insulin resistance

This study was designed to quantitate glucose and FFA disposal by muscle tissue in patients with type II diabetes and to investigate the relationship between FFA metabolism and insulin resistance. The forearm perfusion technique was used in six normal subjects and two groups of normal weight diabetic patients, i.e. untreated (n = 8) and insulin-treated (n = 6). The latter received 2 weeks of intensive insulin therapy before the study. Plasma insulin levels were raised acutely [950-1110 pmol/L) (130-150 microU/mL)], while the blood glucose concentration was clamped at its basal value [4.9 +/- 0.1 (+/- SE) mmol/L in the normal subjects, 5.7 +/- 0.5 in the insulin-treated diabetic patients, and 5.5 +/- 0.3 in the untreated diabetic patients] by a variable glucose infusion. During the control period, arterial FFA concentrations were similar in the three groups, and they decreased to a comparable extent (less than 0.1 mmol/L) in response to insulin infusion. During the control period, the mean forearm FFA uptake was 2.5 +/- 0.5 mumol/L.min in the normal subjects, 2.9 +/- 0.5 in the insulin-treated patients, and 2.1 +/- 0.5 in the untreated diabetic patients. During the insulin infusion, FFA uptake was profoundly suppressed to similar levels in the normal subjects (0.9 +/- 0.1 mumol/L.min), the insulin-treated diabetic patients (1.1 +/- 0.3), and the untreated diabetic patients (0.9 +/- 0.1; P less than 0.001). Forearm glucose uptake was similar in the three groups during the control period. It increased during the insulin infusion, but the response in both diabetic groups was less than that in the normal subjects. The total amounts of glucose taken up by the forearm during the study period were 5.2 +/- 0.7, 2.6 +/- 0.5, and 2.1 +/- 0.6 mmol/L.min in the normal subjects, the insulin-treated diabetic patients, and the untreated diabetic patients, respectively (P less than 0.01). We conclude that 1) insulin-mediated glucose uptake by forearm skeletal muscle is markedly impaired in type II diabetes and improves only marginally after 2 weeks of intensive insulin therapy; 2) in contrast, no appreciable abnormality in forearm FFA metabolism is demonstrable in insulin-treated type II diabetic patients; and 3) FFA do not contribute to the insulin-treated skeletal muscle insulin resistance that occurs in patients with type II diabetes mellitus.

Abnormalities of glucose metabolism induced by liver cirrhosis and glycosylated hemoglobin levels in chronic liver disease

The prevalence of impaired glucose tolerance (IGT) and diabetes mellitus (DM) such as defined by National Diabetes Data Group criteria, and glycosylated hemoglobin levels were assessed in a series of consecutive patients who had chronic active hepatitis (CAH) or cirrhosis in the absence of any known diabetogenic risk factors and who had normal fasting glycemic levels. Based on oral glucose tolerance test, the prevalence of IGT (15%) and DM (27%) in cirrhosis was significantly higher (p less than 0.005) than that observed in CAH (0%) and controls (0%). In contrast, HbA1 levels were not statistically different in cirrhotic patients (with normal or altered glucose tolerance) as compared with CAH and control subjects.

IN CONCLUSION

(a) HbA1 is an unsatisfactory test in the diagnosis of altered glucose tolerance in patients with cirrhosis, and (b) Cirrhosis (but not CAH) represents itself a risk factor for the development of glucose metabolism alterations. Therefore, routine oral glucose tolerance testing is warranted in these patients.

Glycogen depletion during prolonged exercise: influence of glucose, fructose, or placebo

We examined the influence of various carbohydrates of fuel homeostasis and glycogen utilization during prolonged exercise. Seventy-five grams of glucose, fructose, or placebo were given orally to eight healthy males 45 min before ergometer exercise performed for 2 h at 55% of maximal aerobic power (VO2max). After glucose ingestion, the rises in plasma glucose (P less than 0.01) and insulin (P less than 0.001) were 2.4- and 5.8-fold greater than when fructose was consumed. After 30 min of exercise following glucose ingestion, the plasma glucose concentration had declined to a nadir of 3.9 +/- 0.3 mmol/l, and plasma insulin had returned to basal levels. The fall in plasma glucose was closely related to the preexercise glucose (r = 0.98, P less than 0.001) and insulin (r = 0.66, P less than 0.05) levels. The rate of endogenous glucose production and utilization rose similarly by 2.8-fold during exercise in fructose group and were 10-15% higher than in placebo group (P less than 0.05). Serum free fatty acid levels were 1.5- to 2-fold higher (P less than 0.01) after placebo than carbohydrate ingestion. Muscle glycogen concentration in the quadriceps femoris fell in all three groups by 60-65% (P less than 0.001) during exercise. These data indicate that fructose ingestion, though causing smaller perturbations in plasma glucose, insulin, and gastrointestinal polypeptide (GIP) levels than glucose ingestion, was no more effective than glucose or placebo in sparing glycogen during a long-term exercise.

Role of plasma vasopressin in the impairment of water excretion in nephrotic syndrome

To verify whether or not an increased secretion of ADH may cause the water retention commonly observed in nephrotic syndrome, 16 nephrotic patients and 13 normal control subjects were studied in basal conditions and following a water load or an iso-osmotic blood volume expansion by 20% albumin infusion. In the basal condition there were no differences in plasma ADH, urine output, urinary osmolality (UOsm), and plasma renin activity between nephrotic patients and control subjects; POsm, PNa+, UNaV, and blood volume (BV) instead, were significantly lower in nephrotic patients than in control subjects. Following the water load control subjects reached a minimal UOsm of 82 +/- 12 mOsm/kg at 60 min and excreted completely the ingested water in 150 min; nephrotic patients reached a minimal UOsm of 160 +/- 111 mOsm/kg at 120 min, and the water was eliminated completely in 240 min. Plasma ADH decreased significantly in the first hour following water load only in control subjects. A significant direct correlation was observed between plasma ADH and POsm in control subjects (ADH = -85 + 0.30 POsm, P less than 0.001) but not in nephrotic patients. Plasma ADH was inversely correlated with BV in nephrotic patients (ADH = 15.47 -0.17 BV, P less than 0.001) but not in normal control subjects. In nephrotic patients with reduced BV the expansion of BV with 20% albumin was effective in reducing the plasma levels of ADH and promoting a water diuresis. Our results demonstrate a sustained volume mediated secretion of ADH in the nephrotic syndrome, which is responsible for the impairment in water excretion.

Effects of oral salt loading on beta-adrenergic receptor responsiveness in normal and hypertensive subjects

The effect of oral salt loading (400 mmol per day of NaCl for 7 days) on cardiac and pancreatic beta-receptor responsiveness has been evaluated in 12 patients with established essential hypertension and in seven age-matched control subjects. Cardiac beta-receptor responsiveness was evaluated by assessing the dose of isoprenaline which increased a stable heart rate by 25% (chronotropic dose 25%, CD 25%). Pancreatic beta-receptor responsiveness was measured by the incremental areas of insulin secretion induced by iv infusion of increasing amounts of isoprenaline. Before salt load, CD 25% was significantly higher in hypertensives compared with controls (7.84 +/- 1.34 micrograms vs 3.9 +/- 0.48 micrograms, P less than 0.05) while there was no difference in the isoprenaline-induced insulin secretion between the two groups of subjects. After salt loading, CD 25% was significantly reduced in hypertensive patients but was not modified in normal subjects. Therefore, the difference in CD 25% was no longer detectable between the two groups (5.5 +/- 1.42 micrograms vs 3.2 +/- 0.48 micrograms in normal subjects and in hypertensives, respectively, NS). Furthermore, salt loading failed to induce any change in isoprenaline-induced insulin secretion in either groups. These results support the existence of a relationship between sodium intake and adrenergic beta-receptor responsiveness in human hypertension.

Influence of acetylsalicylic acid on glucose turnover in normal man

This study was designed to evaluate the influence of intravenous infusion (72 mg min-1) of lysine acetylsalicylate (LAS), an inhibitor of endogenous prostaglandin synthesis, on glucose homeostasis in normal man. LAS infusion produced a transient decrease of both hepatic glucose production (Ra, p less than 0.01) and peripheral glucose uptake (Rd, p less than 0.01). Since Ra fell more than Rd, a slight but significant decrease of plasma glucose concentration occurred. Glucose metabolic clearance rate also showed a rapid, although transient, decrease after the start of LAS infusion. Plasma insulin rose twofold in response to LAS, while plasma glucagon remained unchanged. The failure of the glucose clearance to increase as a consequence of the augmented insulin levels suggests that salicylate compounds may cause a state of insulin resistance.

Renal function in borderline hypertensive first-degree relatives of essential hypertensives. Effects of sodium load

Renal function in the basal state and after sodium load has been investigated in 21 borderline, hypertensive, first-degree relatives of established hypertensives and in 21 age- and sex-matched, normal subjects with no family history of hypertension. During intravenous infusion of inulin and p-aminohippurate in saline, both groups showed a decrease in plasma aldosterone levels (p less than 0.05) but renal plasma flow (595 +/- 48 vs. 750 +/- 59 ml/min, p less than 0.05), diuresis (1.4 +/- 0.2 vs. 2.2 +/- 0.5 ml/min, p less than 0.05), natriuresis (0.21 +/- 0.02 vs. 0.3 +/- 0.02 mEq/min, p less than 0.05) and sodium clearance (1.05 +/- 0.1 vs. 2.4 +/- 0.4 ml/min, p less than 0.05) in borderline hypertensives were higher than in the control group. After the salt load (NaCl, 1.35% i.v., 5 ml/min for 2 h) there was an increase in blood pressure and a decrease in plasma aldosterone and potassium levels in both groups. However, borderline hypertensives showed higher diuresis, natriuresis, sodium clearance and also kaliuresis compared to normotensives. These results suggest that borderline hypertensives already present the changes in renal function which are characteristics of established hypertensives.

Inverted response of arginine vasopressin to postural change in patients with essential hypertension

1. This study was designed to compare the response of plasma arginine vasopressin (AVP) to head-up tilt in hypertensive patients and in normals. 2. As expected, plasma AVP showed a consistent increase (P less than 0.005) in normal subjects after tilt while plasma volume decreased significantly (P less than 0.02). On the contrary, in hypertensive patients, after tilt both plasma AVP (P less than 0.025) and plasma volume (P less than 0.05) decreased. 3. These findings, thus, indicate that essential hypertension is characterized by an inverted response of arginine vasopressin to postural change.

Baroreflex responsiveness in borderline hypertensives: a study with neostigmine

The baroreflex response to changes in transmural pressure throughout the arterial tree or limited to the carotid sinus was evaluated in ten borderline hypertensives and compared with that observed in ten normal subjects and in ten established hypertensives. Baroreceptor sensitivity was tested by evaluating both heart rate response to phenylephrine-induced increase in arterial pressure and heart rate and blood pressure changes induced by increased neck tissue pressure by means of a neck chamber. The heart rate response to phenylephrine (evaluated by the regression of the R-R interval versus the systolic blood pressure) was depressed both in borderline and established hypertensives as compared with controls. Similarly, the heart rate and the pressor response to increased neck tissue pressure were depressed in both groups of hypertensives. In borderline, but not in established hypertensives, neostigmine administration improved consistently the pressor baroreflex response to increased neck tissue pressure and the heart rate reflex response to both the employed stimuli. These findings indicate that a reduced parasympathetic activity is one of the components involved in the altered baroreflex sensitivity in borderline hypertensives.

Hyperglycemia inhibits glucose production in man independent of changes in glucoregulatory hormones

To evaluate the influence of hyperglycemia on hepatic glucose output in the absence of a rise in insulin, glucose was infused for 2 hours into six juvenile-onset diabetics receiving a constant infusion of insulin at a rate of 0.05-0.15 microM kg-1min-1. Prior to the infusion of glucose, insulin administration resulted in stable levels of plasma glucose (76 +/- 8 mg/dl) and glucose output (1.9 +/- 0.1 mg kg-1min-1). The addition of glucose produced a 2-3 fold rise in plasma glucose and a prompt fall in glucose output to 0.2-0.4 mg kg-1min-1, despite the unchanged rate of insulin infusion and the absence of a reduction in plasma glucagon or catecholamines. A similar decline in glucose output was observed when exogenous glucagon (1 ng kg-1-min-1) was added to the glucose infusion. We conclude that in the presence of basal insulin levels hyperglycemia inhibits glucose output independent of a rise in insulin or a fall in anti-insulin hormones.

Histamine mediation in muscular vasodilatation induced by beta adrenoceptor stimulation in dogs

This study was designed to investigate the possibility of a histamine mediation in muscular vasodilation induced by beta adrenoceptor stimulation. Accordingly, in seven dogs the effects of isoproterenol administration on the release of 14C-histamine from the perfused gracilis muscle were studied. Beta adrenoceptors stimulation induced a vasodilatation, as shown by a decrease in perfusion pressure(-43 +/- 12 mm Hg); simultaneously, a significant increase of the radioactivity measured in the venous blood effluent from the gracilis muscle was observed. Both these events were blocked by propranolol. In the other five dogs, chlorpheniramine was able to reduce the vasodilatation induced by the injection in the gracilis muscle of isoproterenol. Under control conditions, isoproterenol induced a fall in perfusion pressure of 44 +/- 5 mm Hg while, after chlorpheniramine, perfusion pressure decreased by only 24 +/- 4 mm Hg. The results of this study seem to confirm the possibility of a histamine mediation in isoproterenol-induced vasodilatation. However, further investigation is needed in order to identify the exact role of histamine in the geneis of this phenomenon.

Participation of beta receptors in reflex vasodilatation in the dog

The effects of propranolol, given by direct intraarterial injection, on the reflex vasodilatation induced in the atropinized isolated gracilis muscle by rapid intravenous administration of norepinephrine, were studied in dogs. In these studies, both atropine and atropine plus propranolol did not significantly alter the maximum fall in vascular resistance in the perfused gracilis muscle following intravenous norepinephrine; however, if the reflex responses were evaluated as integrated areas of vasodilatation, atropine attenuated the vasodilatation and the administration of propranolol further attenuated the reflex. In fact, the value of the integrated areas of vasodilatation was 52.8 +/- 9 mmHg/min in the basal state, 39 +/- 6 mmHg/min after administration of atropine, and 24 +/- 7 mmHg/min after propranolol, whereas the integrated areas of the systemic hypertension did not show any modification. These results prompt us to conclude that the adrenergic beta receptors participate in the reflex vasodilatation, although the mechanism of their action needs further elucidation.

Effects of theophylline on glucose kinetics in normal and sympathectomized rats

The influence of intraperitoneal administration of aminophylline on the rate of hepatic glucose production and peripheral uptake (Ra and Rd) was studied in normal and in adrenodemedullated and reserpinized rats by using the primed constant infusion of Glucose-2-3H. In normal rats, the dose of 100 mg. per kilogram of aminophylline produced a marked increase of Ra and Rd. Since Ra rose more rapidly than Rd did initially, hyperglycemia developed. Thereafter, glucose production and uptake increased to nearly the same extent, and a new steady state was reached at plasma glucose levels almost twice those of the baseline. Smaller and transient modifications were observed after the administration of 20 mg. per kilogram of aminophylline. With the higher dose, insulin levels markedly rose (reaching a tenfold peak above the basal value) while minor increments were observed with the lower dose. In a group of normal rats which were given glucose (10 mg. per kilogram per minute) in order to achieve a degree of hyperglycemia comparable to that brought about by the higher dose of aminophylline, an almost identical enhancement of glucose uptake was recorded. However, insulin levels were much higher in aminophylline-treated rats as compared to normal rats. From these finding it was concluded that aminophylline induces resistance to insulin effect. When aminophylline was injected into demedullated rats pretreated with reserpine, at the dose of 100 mg. per kilogram, a marked enhancement of Ra, and consequently of glycemia, was recorded initially; later, severe hypoglycemia developed depending on both a progressive exhaustion of hepatic glucose production and a marked increase of glucose utilization. Insulin levels dramatically increased in these experiments. These results suggest that aminophylline directly increases glucose production by the liver and insulin secretion. The simultaneous activation of the sympathetic system blunts the insulin response and counteracts the restraining effect of insulin on the liver and the stimulatory effect of insulin on overall glucose uptake as well.

Effects of different prostaglandins on glucose kinetics in the rat

The primed constant infusion of glucose-2−3H was used to study the influence of prostaglandins (PGs) infusion (2μg./min.) on glucose turnover in intact rats in the postabsorptive state. While PGA1 did not exert any appreciable effect on glucose production by the liver and on plasma glucose levels, prostaglandins of E-series significantly increased hepatic glucose output and consequently plasma glucose levels. In this regard, PGE1 appeared more effective than PGE2. In some experiments PGE1 was infused for two hours at the dose of 1.5μg./xmin.: glucose concentration rose to a maximum of 127 per cent above the control values and glucose production reached during the second hour of the infusion a level twice the base line (from 8.1 ±0.5 to 16.9±0.5 mg./kg. body weight/min.). These changes were paralleled by a proportional increase in glucose uptake by peripheral tissues which reached a level very near to that of hepatic output toward the end of the infusion.