Identification of Novel Glucose-Dependent Alterations Responsible for Vascular Dysfunction in Type 2 Diabetes Mellitus (T2DM) I

Despite the plethora of drugs currently available for managing coronary artery disease (CAD) patients with or without type 2 diabetes mellitus (T2DM), yet CAD frequently progresses, necessitating a coronary artery bypass graft (CABG) procedure using human saphenous vein (HSV). However, over 70 % of the procedures fail after 10 years in T2DM patients. We propose that this is due in part to glucose-dependent alterations in the function of HSV smooth muscle cell (HSVSMC), a key cell type involved in vascular dysfunction. Therefore, in this project, we examined T2DM-dependent alterations, including protein O-GlcNAcylation, a dynamic and reversible post-translational modification, in the metabolic profile and function of HSVSMC from T2DM patients versus non-diabetic control. Under NHRA ethics approval (NHS REC:15/NE/0138), HSVSMCs were explanted from surplus HSV tissues from T2DM and non-diabetic patients undergoing CABG. Expression levels of O-GlcNAcase (OGA), O-GlcNAc transferase (OGT), and Glutamine-fructose-6P amidotransferase (GFAT) were determined in lysates of HSVSMCs from T2DM versus non-diabetic patients by SDS-PAGE and immunoblotting using specific antibodies. This experiment was repeated using lysates of HSVSMCs treated with high glucose (HG) concentrations (10 mM and 25 mM) for 48 hours. Our results showed that their expression levels were not significantly different in T2DM patients versus non-diabetic controls, and after treatment with HG concentrations. Furthermore, we used the Seahorse XFP analyzer to determine real-time mitochondrial function of HSVSMCs by measuring the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) after sequential addition of modulators of respiration; oligomycin, carbonyl cyanide p-(trifluoromethoxy) phenylhydrazone (FCCP), and rotenone and antimycin A. Results revealed that versus unstimulated cells, IL-6/sIL-6Rα and PDGF-BB caused an increase in OCR (102.5% and 93.9% in maximal respiration, respectively) and ECAR (basal glycolysis 101.6%; glycolytic reserve 76.3%; maximal glycolysis 117.1%; glycolytic reserve 99.3%, for PDGF-BB) in HSVSMCs from T2DM patients but not in those from non-diabetic control. However, this observed increase was abolished by ruxolitinib. Similarly, versus unstimulated cells, thrombin but not Ang II caused a significant increase in OCR (85.2% in maximal respiration) of HSVSMCs from T2DM patients, and this was abolished by trametinib. Furthermore, flow cytometry assay showed that both ruxolitinib and trametinib versus unstimulated cells significantly reduced mitochondrial reactive oxygen species’ production in HSVSMCs from both T2DM (133.2% and 154.8% respectively) and non-diabetic (114.8% and 107.4% respectively) patients. These findings suggest a JAK/STAT- and MAPK/ERK-mediated regulation of mitochondrial function of HSVSMCs, hence, potential targets for regulation of the function of HSVSMCs which can be explored for drug development to limit SV graft failure

Targeting Protein O-GlcNAcylation, a Link between Type 2 Diabetes Mellitus and Inflammatory Disease

Unresolved hyperglycaemia, a hallmark of type 2 diabetes mellitus (T2DM), is a well characterised manifestation of altered fuel homeostasis and our understanding of its role in the pathologic activation of the inflammatory system continues to grow. Metabolic disorders like T2DM trigger changes in the regulation of key cellular processes such as cell trafficking and proliferation, and manifest as chronic inflammatory disorders with severe long-term consequences. Activation of inflammatory pathways has recently emerged as a critical link between T2DM and inflammation. A substantial body of evidence has suggested that this is due in part to increased flux through the hexosamine biosynthetic pathway (HBP). The HBP, a unique nutrient-sensing metabolic pathway, produces the activated amino sugar UDP-GlcNAc which is a critical substrate for protein O-GlcNAcylation, a dynamic, reversible post-translational glycosylation of serine and threonine residues in target proteins. Protein O-GlcNAcylation impacts a range of cellular processes, including inflammation, metabolism, trafficking, and cytoskeletal organisation. As increased HBP flux culminates in increased protein O-GlcNAcylation, we propose that targeting O-GlcNAcylation may be a viable therapeutic strategy for the prevention and management of glucose-dependent pathologies with inflammatory components

Maternal Folate Status and Preterm Birth in the Boston Birth Cohort

Preterm birth (PTB) is one of the most pressing challenges to maternal and child health in the United States (US). There remains an urgent need to identify important and modifiable risk factors for PTB among those most at risk- such as urban low income, Non-Hispanic blacks. This dissertation aimed to: i) evaluate the relationship between maternal folate status and risk of PTB and ii) investigate the biologic plausibility of the folate-PTB association by evaluating the role of folate on major pathogenic pathways leading to PTB –namely preeclampsia and intrauterine infection/inflammation (IUI). The analyses included 7565 mother-newborn dyads and a subsample (n=2313) with plasma folate assay at delivery in Boston Birth Cohort. There was an inverse relationship between the frequency of multivitamin supplement intake and PTB. Compared to less frequent use, multivitamin supplement intake 3-5 times/week (adjusted odds ratio (aOR)= 0.78, 95% confidence interval (CI): 0.64, 0.96) or >5 times/week (aOR= 0.77, 95% CI: 0.64, 0.93) throughout pregnancy was associated with reduced risk of PTB. Multivitamin supplement intake of three or more times a week in the 3rd trimester was associated with reduced odds of preeclampsia (aOR=0.77, 95% CI: 0.65, 0.93). Each interquartile increase in plasma folate reduced the odds of preeclampsia by 20% (aOR=0.80, 95% CI: 0.68,0.95). Preeclampsia mediated 62% of the relationship between multivitamin supplement intake and medically indicated PTB. Multivitamin supplement intake of three or more times a week in the 3rd trimester (aOR=0.74, 95% CI: 0.63, 0.87) was associated with reduced odds of IUI. Each interquartile increase in plasma folate reduced the odds of IUI by 15% (aOR=0.85, 95% CI: 0.73, 0.98). Joint analysis of IUI and multivitamin supplement intake showed that multivitamin intake attenuated the relationship between IUI and PTB. Findings from this study are relevant to policies and interventions, specifically among vulnerable populations. The results of this dissertation have a potential impact on ongoing research, clinical and programmatic efforts to improve prenatal nutrition and birth outcomes. Findings may inform the design and implementation of nutrition-based screening and interventions to prevent PTB and associated short-term and long-term consequences

Health behavior profiles and association with mental health status among US active-duty service members

IntroductionThis study investigated the clustering of health behaviors among US active duty servicemembers (ADSM) into risk profiles and explored the association between these profiles with ADSM sociodemographic characteristics and mental health status.MethodsThis study utilized secondary data from the 2018 Health Related Behaviors Survey (HRBS), a Department of Defense (DoD) self-administered online survey. Health behaviors included physical activity, screen use, sleep habits, tobacco/substance use, alcohol drinking, preventive health care seeking and condom use at last sex/having multiple sexual partners. Past-year mental health status was measured using the Kessler Screening Scale for Psychological Distress (K6). Latent class analysis (LCA) on health behaviors was used to cluster ADSMs into risk profiles. Multivariable logistic model was used to examine whether ADSM characteristics and mental health status were associated with ADSMs' risk profiles.ResultsThe LCA identified a four-class model that clustered ADSMs into the following sub-groups: (1) Risk Inclined (14.4%), (2) High Screen Users (51.1%), (3) Poor Sleepers (23.9%) and (4) Risk Averse (10.6). Over a tenth (16.4%) of ADSMs were categorized as having serious psychological distress. Being male, younger, less educated, in the Army, Marine Corps or Navy were associated with higher odds of being Risk Inclined (AOR ranging from 1.26 to 2.42). Compared to the reference group of Risk Adverse ADSMs, those categorized as Risk Inclined (AOR: 8.30; 95% CI: 5.16–13.36), High Screen Users (AOR: 2.44; 95% CI: 1.56–3.82) and Poor Sleepers (AOR: 5.26; 95% CI: 3.38–8.19) had significantly higher odds of having serious psychological distress.DiscussionStudy findings suggest opportunities to tailor behavioral and health promotion interventions for each of the distinct risk profiles. For example, ADSM described as Risk Inclined may benefit from preventive mental health services. Solutions for ADSM described as Poor Sleepers may include education on sleep hygiene; instituting duty schedules; and shifting military cultural norms to promote sleep hygiene as a pathway to optimal performance and thus military readiness. ADSM with low-risk behavior profiles such as those described as Risk Averse may prove beneficial in the roll-out of interventions as they act as peer-educators or mentors

Understanding the gap between access and use: a qualitative study on barriers and facilitators to insecticide-treated net use in Ghana

Mass and continuous distribution channels have significantly increased access to insecticide-treated nets (ITNs) in Ghana since 2000. Despite these gains, a large gap remains between ITN access and use.; A qualitative research study was carried out to explore the individual and contextual factors influencing ITN use among those with access in three sites in Ghana. Eighteen focus group discussions, and free listing and ranking activities were carried out with 174 participants; seven of those participants were selected for in-depth case study. Focus group discussions and case study interviews were audio-recorded, transcribed verbatim, and analysed thematically.; ITN use, as described by study participants, was not binary; it varied throughout the night, across seasons, and over time. Heat was the most commonly cited barrier to consistent ITN use and contributed to low reported ITN use during the dry season. Barriers to ITN use throughout the year included skin irritation; lack of airflow in the sleeping space; and, in some cases, a lack of information on the connection between the use of ITNs and malaria prevention. Falling ill or losing a loved one to malaria was the most powerful motivator for consistent ITN use. Participants also discussed developing a habit of ITN use and the economic benefit of prevention over treatment as facilitating factors. Participants reported gender differences in ITN use, noting that men were more likely than women and children to stay outdoors late at night and more likely to sleep outdoors without an ITN.; The study results suggest the greatest gains in ITN use among those with access could be made by promoting consistent use throughout the year among occasional and seasonal users. Opportunities for improving communication messages, such as increasing the time ITNs are aired before first use, as well as structural approaches to enhance the usability of ITNs in challenging contexts, such as promoting solutions for outdoor ITN use, were identified from this work. The information from this study can be used to inform social and behaviour change messaging and innovative approaches to closing the ITN use gap in Ghana

Trends in the completeness of birth registration in Nigeria: 2002-2010

Background: Nigeria is a signatory to the Convention on the Rights of the Child, which identifies birth registration as a child's right. However, it is unclear how much progress has been made toward attaining universal birth registration in the country. Methods: This paper reports findings from a secondary analysis of data from the 2007 and 2011 UNICEF Multiple Indicator Cluster Survey in Nigeria. Trends in birth registration completeness based on year of birth of children and age at survey were computed, tabulated, and graphed. Results: Birth registration completeness was 31.5Š and 41.5Š in 2007 and 2011 respectively. Children had better odds of registration across Nigeria in 2011 than in 2007 (OR 1.79, 95Š CI 1.59-2.01), except in the North East geopolitical zone (OR 0.76, 95Š CI 0.55-1.07). Likewise, older children had better odds of registration than those aged less than one year. Female children had worse chances of registration than their male counterparts (OR 0.92, 95Š CI 0.85-0.99). Conclusions: Birth registration improved in 2011 over 2007 across Nigeria except in the North East region. However, much still needs to be done to achieve universal birth registration. Birth registration appears to still be influenced by the gender and age of the child. Designing and implementing a strategic communication program to educate the population about the processes and benefits of early birth registration may further improve birth registration. Contribution: This paper provides a rigorous assessment of the progress made toward universal birth registration, which has not been previously demonstrated

Complex Transcriptional Profiles of the PPP1R12A Gene in Cells of the Circulatory System as Revealed by In Silico Analysis and Reverse Transcription PCR

The myosin light chain phosphatase target subunit 1 (MYPT1), encoded by the PPP1R12A gene, is a key component of the myosin light chain phosphatase (MLCP) protein complex. MYPT1 isoforms have been described as products of the cassette-type alternative splicing of exons E13, E14, E22, and E24. Through in silico analysis of the publicly available EST and mRNA databases, we established that PPP1R12A contains 32 exons (6 more than the 26 previously reported), of which 29 are used in 11 protein-coding transcripts. An in silico analysis of publicly available RNAseq data combined with validation by reverse transcription (RT)-PCR allowed us to determine the relative abundance of each transcript in three cell types of the circulatory system where MYPT1 plays important roles: human umbilical vein endothelial cells (HUVEC), human saphenous vein smooth muscle cells (HSVSMC), and platelets. All three cell types express up to 10 transcripts at variable frequencies. HUVECs and HSVSMCs predominantly express the full-length variant (58.3% and 64.3%, respectively) followed by the variant skipping E13 (33.7% and 23.1%, respectively), whereas in platelets the predominant variants are those skipping E14 (51.4%) and E13 (19.9%), followed by the full-length variant (14.4%). Variants including E24 account for 5.4% of transcripts in platelets but are rare (<1%) in HUVECs and HSVSMCs. Complex transcriptional profiles were also found across organs using in silico analysis of RNAseq data from the GTEx project. Our findings provide a platform for future studies investigating the specific (patho)physiological roles of understudied MYPT1 isoforms

Age and gender trends in insecticide-treated net use in sub-Saharan Africa: a multi-country analysis

Abstract Background The degree to which insecticide-treated net (ITN) supply accounts for age and gender disparities in ITN use among household members is unknown. This study explores the role of household ITN supply in the variation in ITN use among household members in sub-Saharan Africa. Methods Data was from Malaria Indicator Surveys or Demographic and Health Surveys collected between 2011 and 2016 from 29 countries in sub-Saharan Africa. The main outcome was ITN use the previous night. Other key variables included ITN supply (nets/household members), age and gender of household members. Analytical methods included logistic regressions and meta-regression. Results Across countries, the median (range) of the percentage of households with enough ITNs was 30.7% (8.5–62.0%). Crude analysis showed a sinusoidal pattern in ITN use across age groups of household members, peaking at 0–4 years and again around 30–40 years and dipping among people between 5–14 and 50+ years. This sinusoidal pattern was more pronounced in households with not enough ITNs compared to those with enough ITNs. ITN use tended to be higher in females than males in households with not enough ITNs while use was comparable among females and males in households with enough ITNs. After adjusting for wealth quintile, residence and region, among households with not enough ITNs in all countries, the odds of ITN use were consistently higher among children under 5 years and non-pregnant women 15–49 years. Meta-regressions showed that across all countries, the mean adjusted odds ratio (aOR) of ITN use among children under 5 years, pregnant and non-pregnant women aged 15–49 years and people 50 years and above was significantly higher than among men aged 15–49 years. Among these household members, the relationship was attenuated when there were enough ITNs in the household (dropping 0.26–0.59 points) after adjusting for geographical zone, household ITN supply, population ITN access, and ITN use:access ratio. There was no significant difference in mean aOR of ITN use among school-aged children compared to men aged 15–49 years, regardless of household ITN supply. Conclusions This study demonstrated that having enough ITNs in the household increases level of use and decreases existing disparities between age and gender groups. ITN distribution via mass campaigns and continuous distribution channels should be enhanced as needed to ensure that households have enough ITNs for all members, including men and school-aged children

Malaria prevention and care seeking among gold miners in Guyana.

Despite being a priority population in malaria elimination, there is scant literature on malaria-related behavior among gold miners. This study explores the prevalence and factors influencing malaria prevention, care seeking and treatment behaviors in Guyana gold mining camps. A cross sectional survey was conducted among adult gold miners living in mining camps in the hinterland Regions 1 (Barima-Waini), 7 (Cuyuni-Mazaruni), and 8 (Potaro-Siparuni). Multivariable logistic regressions explored factors associated with miners' self-report of mosquito net use, prompt care-seeking; self-medication; and testing for malaria. A third of miners used a mosquito net the night preceding the survey and net use was higher among those who believed that net use was the norm in their camp (aOR: 3.11; 95% CI:1.65, 5.88). Less than half (45%) of miners had a fever in the past 12 months, among whom 36% sought care promptly, 48% tested positive for malaria while 54% self-medicated before seeking care. Prompt care-seeking was higher among miners with high malaria knowledge (aOR: 1.44; 95% CI: 1.01, 2.05). Similarly, testing rates increased with secondary education (aOR: 1.71; 95% CI: (1.16, 2.51), high malaria knowledge (aOR: 1.45; 95% CI: 1.02, 2.05), positive beliefs regarding malaria transmission, threat, self-diagnosis, testing and treatment, and, trust in government services (aOR: 1.59; 95% CI (1.12, 2.27) and experience of a prior malaria episode (aOR: 2.62; 95% CI: 1.71, 4.00). Self-medication was lower among male miners (aOR: 0. 52; 95% CI: 0.32, 0.86). Malaria prevention and care seeking behaviors among miners are somewhat low and influenced by mosquito net usage, perceived norms, malaria knowledge and prior episode of confirmed malaria. Study findings have implications for malaria interventions in the hinterland regions of Guyana such as the mass and continuous distribution of insecticide treated nets as well as community case management initiatives using trained malaria testing and treatment volunteers to curb malaria transmission among remote gold mining populations. These include efforts to identify and address gaps in distributing mosquito nets to miners and address miners' barriers to prompt care seeking, malaria testing and treatment adherence. Targeted social and behavior change messaging is needed on net acquisition, use and care, prompt care-seeking, malaria testing and treatment adherence. Additional efforts to ensure the overall sustainability of the community case management initiative include increased publicity of the community case management initiative among miners, use of incentives to promote retention rates among the community case management volunteer testers and public private partnerships between the Guyana Ministry of Health and relevant mining organizations