A novel home-based method for preparing suspensions of anti-TB drugs.

BACKGROUND: Tablets are the most widely available dosage form for the treatment of TB; however, adult tablets fail to meet the needs of young children who cannot swallow these tablets or require dose titration. We tested a new, simple device (XTEMP-R®) and the methodology for converting tablets of TB drugs into a homogeneous suspension for home use by children and caregivers.METHODS: XTEMP-R is a new device used for converting tablets into liquid preparations. Four TB drugs - pretomanid, delamanid, clofazimine and bedaquiline - were dispersed in the device utilizing water and simple syrup. The reproducibility of accurately delivering aliquots from the suspension upon preparation and upon redispersion after storing for 2 days was studied.RESULTS: Suspensions of each of the drugs tested were easily prepared in about 10 min and were visually uniform in consistency. Dosages in 2 and 5 mL were assessed in suspension, and those in 5 mL tested upon redispersion after 2 days. The observed range for these dosages spanned from 94.6% to 101.1% of the theoretical concentration for the suspensions under examination. The cleaned device had no detectable residual drug.CONCLUSION: XTEMP-R can be used at home by caregivers to prepare doses of suspensions accurately for children and patients who cannot swallow tablets.

Factors Contributing to Delays to Accessing Appendectomy in Low- and Middle-Income Countries: A Scoping Review.

BACKGROUND: Appendicitis is one of the most common emergency surgical conditions worldwide. Delays in accessing appendectomy can lead to complications. Evidence on these delays in low- and middle-income countries (LMICs) is lacking. The aim of this review was to identify and synthesise the available evidence on delays to accessing appendectomy in LMICs. METHODS: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis Extension for Scoping Reviews framework. The delays and their interconnectivity in LMICs were synthesised and interpreted using the Three Delays framework. We reviewed Africa Wide EBSCOhost, PubMed-Medline, Scopus, Web of Science, African Journals Online (AJOL), and Bioline databases. RESULTS: Our search identified 21 893 studies, of which 78 were included in the final analysis. All of the studies were quantitative. Fifty per cent of the studies included all three types of delays. Delays in seeking care were influenced by a lack of awareness of appendicitis symptoms, and the use of self and alternative medication, which could be linked to delays in receiving care, and the barrier refusal of medical treatment due to fear. Financial concerns were a barrier observed throughout the care pathway. CONCLUSION: This review highlighted the need for additional studies on delays to accessing appendectomy in additional LMICs. Our review demonstrates that in LMICs, persons seeking appendectomy present late to health-care facilities due to several patient-related factors. After reaching a health-care facility, accessing appendectomy can further be delayed owing to a lack of adequate hospital resources.

Stable, compounded bedaquiline suspensions to support practical implementation of pediatric dosing in the field.

BACKGROUND: Bedaquiline (BDQ) tablets are indicated as part of a combination regimen for the treatment of multidrug-resistant TB in adults, adolescents and children. A dispersible tablet formulation is now approved but is not currently available in all settings. The aim of this study was to develop stable extemporaneous liquid formulations of BDQ that can be stored at room temperature or 30°C for several weeks, to support pragmatic pediatric dosing in the field and reduce wastage.METHODS: BDQ tablets were suspended in simple syrup and a sugar-free vehicle. Each 20 mg/mL formulation was stored at room temperature or 30°C for 30 days in amber dispensing bottles. Appearance, BDQ potency, pH and microbial counts were determined on Days 0, 15 and 30.RESULTS: The BDQ potency in both formulations remained at 98-101% of the theoretical concentration for 30 days. The appearance, pH and microbial count of sugar-free formulation did not change during the 30-day storage. The simple syrup formulation was stable for 15 days as microbial growth was observed on Day 30.CONCLUSIONS: BDQ may be prepared in syrup or sugar-free suspensions: syrup suspensions can be stored for 15 days at room temperature and 30C, whereas sugar-free suspensions can be stored for 30 days at room temperature and 30C. This information will support practical BDQ dosing for children in the field.

Extemporaneously compounded liquid formulations of clofazimine.

BACKGROUND: Clofazimine (CFZ) is routinely used worldwide for the treatment of leprosy and TB. However, no liquid or dispersible tablet formulations of CFZ are currently available commercially for patients with challenges ingesting soft gelatin capsules or solid formulations. The aim of this research was to develop stable extemporaneous liquid formulations of CFZ that can be stored at room temperature for several weeks to enable practical dosing in the field. METHODS: Two formulations were prepared in syrup and sugar-free vehicles with CFZ tablets using a simple method that can be used in a routine pharmacy. Suspensions were stored at room temperature and at 30°C for 30 days. Formulation aliquots were tested on Days 0, 15 and 30 for appearance, pH, potency and microbial counts. RESULTS: Appearance remained unchanged during storage. The pH of both formulations was between 4.0 and 6.0. Potency was between 90% and 110% for 30 days in the syrup formulation and for 15 days in the sugar-free formulation. Microbial counts met United States Pharmacopeia 1111 limits for oral aqueous liquids and specific organisms were absent. CONCLUSIONS: A simple field-friendly method was successfully developed for the preparation of CFZ liquid formulations using commonly available ingredients. This will permit practical dosing and titration for children and other patients with swallowing challenges.

Sugar and sugar-free liquid formulations of delamanid for patients with rifampicin-resistant TB.

BACKGROUND: Delamanid (DLM) tablets are recommended for the treatment of rifampicin-resistant TB. However, no liquid or dispersible tablet formulation of DLM is currently commercially available for patients with challenges ingesting these tablets. The aim of this study was to develop stable extemporaneous liquid formulations of DLM that can be stored at room temperature for several weeks.METHODS: DLM tablets were suspended in 1) simple syrup and 2) a specially formulated sugar-free vehicle. These suspensions containing DLM 5 mg/mL were stored in plastic prescription bottles at room temperature or 30°C for 30 days. These suspensions were evaluated for appearance, potency, pH, and microbial counts at Days 0, 15, and 30.RESULTS: The potency of DLM in each formulation remained at 98-104% of the theoretical concentration for 30 days. The appearance, pH, and microbial count did not change for the sugar-free formulation during the 30-day storage period. Microbial growth, however, was observed in the simple syrup formulation on Day 30 but not on Day 15.CONCLUSION: DLM can be formulated in sugar or sugar-free suspensions and stored at room temperature or 30°C for at least 15 and 30 days, respectively.

Stable sugar and sugar-free suspensions of pretomanid.

BACKGROUND: Pretomanid (PMD) tablets are indicated as part of a combination regimen for the treatment of adults with pulmonary extensively drug-resistant, treatment-intolerant or non-responsive multidrug-resistant TB. No commercial liquid formulation is currently available for patients unable to swallow these tablets.OBJECTIVE: To develop stable extemporaneous liquid formulations of PMD that can be stored at room temperature or 30°C for at least 4 weeks.METHODS: Crushed PMD tablets were formulated into 20 mg/mL suspensions in a simple syrup and sugar-free formulation. The PMD formulations were stored at room temperature and at 30°C for 30 days in dispensing bottles. Appearance, pH, potency and microbial counts of the suspensions were determined on Days 0, 15 and 30.RESULTS: The potency of PMD remained at 99.7-103.4% of the theoretical concentration in each formulation. The appearance, pH and microbial count did not change during the 30-day storage period. Simple syrup formulations did not require preservatives for microbial stability.CONCLUSIONS: PMD oral suspension formulations in simple syrup or in sugar-free vehicle were easily prepared by utilising commonly available equipment and ingredients and were stable for 30 days. These formulations are appropriate alternatives for patients with swallowing difficulties.

Cancer and Covid-19: Collectively catastrophic.

The Covid-19 pandemic has spread rapidly across the globe, resulting in more than 3 million deaths worldwide. The symptoms of Covid-19 are usually mild and non-specific, however in some cases patients may develop acute respiratory distress syndrome (ARDS) and systemic inflammation. Individuals with inflammatory or immunocompromising illnesses, such as cancer, are more susceptible to develop ARDS and have higher rates of mortality. This is mediated through an initial hyperstimulated immune response which results in elevated levels of pro-inflammatory cytokines and a subsequent cytokine storm. This potentiates positive feedback loops which are unable to be balanced by anti-inflammatory mediators. Therefore, elevated levels of IL-1ß, as a result of NLRP3 inflammasome activation, as well as IL-6 and TNF-α amongst many others, contribute to the progression of various cancer types. Furthermore, Covid-19 progression is associated with the depletion of CD8+ and CD4+ T cells, B cell and natural killer cell numbers. Collectively, a Covid-19-dependent pro-inflammatory profile and immune suppression promotes the optimal microenvironment for tumourigenesis, initiation and immune evasion of malignant cells, tumour progression and metastasis as well as cancer recurrence. There are, however, therapeutic windows of opportunity that may combat both Covid-19 and cancer to improve patient outcomes.

The perceived influence of diversity factors on effective strategy implementation in a higher education institution.

Managing diversity is one of the major challenges in higher education institutions in South Africa. Additionally, effective strategy implementation is vital for an institution to be successful and sustainable. Questionnaires were distributed to the management of Walter Sisulu University, South Africa, to investigate the relationship between diversity factors and effective strategy implementation. The questionnaires interrogated the effect of the acculturation process, the degree of structural integration, the degree of informal integration, institutional bias and intergroup conflict, and how these factors influence strategy implementation. Structural equation modelling (SEM) was employed as the statistical tool to confirm the hypothetical model. Results of this study revealed that there is no statistically significant relationship between diversity and strategy implementation at the institution, and imply that diversity among staff do not impact on the successful achievement of strategic objectives in the institution. The findings of the study are contrary to empirical evidence by other studies.

Deriving an optimal threshold of waist circumference for detecting cardiometabolic risk in sub-Saharan Africa.

BACKGROUND: Waist circumference (WC) thresholds derived from western populations continue to be used in sub-Saharan Africa (SSA) despite increasing evidence of ethnic variation in the association between adiposity and cardiometabolic disease and availability of data from African populations. We aimed to derive a SSA-specific optimal WC cut-point for identifying individuals at increased cardiometabolic risk. METHODS: We used individual level cross-sectional data on 24 181 participants aged ⩾15 years from 17 studies conducted between 1990 and 2014 in eight countries in SSA. Receiver operating characteristic curves were used to derive optimal WC cut-points for detecting the presence of at least two components of metabolic syndrome (MS), excluding WC. RESULTS: The optimal WC cut-point was 81.2 cm (95% CI 78.5-83.8 cm) and 81.0 cm (95% CI 79.2-82.8 cm) for men and women, respectively, with comparable accuracy in men and women. Sensitivity was higher in women (64%, 95% CI 63-65) than in men (53%, 95% CI 51-55), and increased with the prevalence of obesity. Having WC above the derived cut-point was associated with a twofold probability of having at least two components of MS (age-adjusted odds ratio 2.6, 95% CI 2.4-2.9, for men and 2.2, 95% CI 2.0-2.3, for women). CONCLUSION: The optimal WC cut-point for identifying men at increased cardiometabolic risk is lower (⩾81.2 cm) than current guidelines (⩾94.0 cm) recommend, and similar to that in women in SSA. Prospective studies are needed to confirm these cut-points based on cardiometabolic outcomes.International Journal of Obesity advance online publication, 31 October 2017; doi:10.1038/ijo.2017.240.

Recent advances in understanding hypertension development in sub-Saharan Africa.

Consistent reports indicate that hypertension is a particularly common finding in black populations. Hypertension occurs at younger ages and is often more severe in terms of blood pressure levels and organ damage than in whites, resulting in a higher incidence of cardiovascular disease and mortality. This review provides an outline of recent advances in the pathophysiological understanding of blood pressure elevation and the consequences thereof in black populations in Africa. This is set against the backdrop of populations undergoing demanding and rapid demographic transition, where infection with the human immunodeficiency virus predominates, and where under and over-nutrition coexist. Collectively, recent findings from Africa illustrate an increased lifetime risk to hypertension from foetal life onwards. From young ages black populations display early endothelial dysfunction, increased vascular tone and reactivity, microvascular structural adaptions as well as increased aortic stiffness resulting in elevated central and brachial blood pressures during the day and night, when compared to whites. Together with knowledge on the contributions of sympathetic activation and abnormal renal sodium handling, these pathophysiological adaptations result in subclinical and clinical organ damage at younger ages. This overall enhanced understanding on the determinants of blood pressure elevation in blacks encourages (a) novel approaches to assess and manage hypertension in Africa better, (b) further scientific discovery to develop more effective prevention and treatment strategies and

Cardiac Troponin T as Early Marker of Subclinical Cardiovascular Deterioration in Black Hypertensive Women.

BACKGROUND: Hypertensive heart disease is a rising concern, especially among black South African women. As high sensitivity cardiac troponin T (cTnT) is a marker of cardiomyocyte damage, we determined the potential link of (i) systemic endothelial dysfunction (reflected by urinary albumin-to-creatinine ratio), (ii) large artery stiffness, (iii) cardiac volume load (estimated by the N-terminal prohormone B-type natriuretic peptide (Nt-proBNP)), and (iv) ECG left ventricular hypertrophy in post-menopausal black women. METHODS: In 121 (50 normotensive and 71 hypertensive) black women (mean age: 60.6 years), basic cardiovascular assessments including blood pressure and ECG were performed, along with plasma and urinary biomarkers including cTnT. RESULTS: The cTnT levels (p=0.049) along with Nt-proBNP (p=0.003), pulse pressure (p<0.0001) and the Cornell product (p=0.030) were higher in hypertensive than normotensive women. Only in hypertensive women, was cTnT independently associated with urinary albumin-to-creatinine ratio (ß=0.25; p=0.019), pulse pressure (ß=0.31; p=0.019), Nt-proBNP (ß=0.47; p<0.0001) and Cornell product (ß=0.31; p=0.018). An independent association between albumin-to-creatinine ratio and cTnT was also evident in normotensive women (ß=0.34; p=0.037). CONCLUSION: We found cTnT to be a useful marker in an elderly black population relating to several measures of cardiovascular deterioration - from subclinical endothelial dysfunction to left ventricular hypertrophy.

Endothelial activation and cardiometabolic profiles of treated and never-treated HIV infected Africans.

OBJECTIVE: The role the human immunodeficiency virus (HIV) and antiretroviral treatment on endothelial activation, and the subsequent relationship with cardiovascular disease, is not well understood. We investigated endothelial activation, inflammatory and cardiometabolic profiles, and measures of vascular structure and function of 66 antiretroviral treated (ART), 78 never-treated (no-ART) HIV infected and 165 HIV free Africans. METHODS: Blood samples were obtained for biochemical analysis and blood pressure, pulse wave velocity (PWV) and carotid intima-media thickness (IMT) measurements were performed. RESULTS: The HIV infection duration was at least five years and the treatment 2.86±0.13 years. The intracellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) levels were elevated in the HIV infected groups compared to the controls. The odds of higher adhesion molecule levels were increased when HIV infected (especially in the no-ART group); OR no-ART vs. no-HIV: ICAM 3.92 (2.2-7.0); VCAM 16.2 (7.5-35). ICAM and VCAM associated with HIV status and interleukin-6 (IL-6) in the total group (all p<0.01). In both HIV infected groups VCAM associated inversely with CD4 counts (no-ART: ß=-0.28, p=0.01; ART: ß=-0.22, p=0.07) and TC (no-ART: ß=-0.36, p<0.01; ART: ß=-0.27, p=0.03). The ART group had an unfavourable lipid profile compared to the no-ART group. The inflammatory markers (C-reactive protein (CRP) and IL-6), PWV and IMT did not differ between the three groups. CONCLUSION: HIV infected Africans showed endothelial activation when compared to HIV free controls. The endothelial activation was not accompanied by increased inflammation (as measured with CRP and IL-6), arterial stiffness or sub-clinical atherosclerosis.

Leptin is positively associated with blood pressure in african men with a low body mass index: the SAfrEIC study.

Severe underweight may be a risk factor for hypertension in developing countries, although the manner whereby this occurs is unknown. Leptin is known to exert both beneficial and detrimental vascular effects, and is predictive of poor cardiovascular outcome at high levels, but also at low levels. We explored the relationship between blood pressure and leptin in black men from South Africa with a body mass index (BMI) in the underweight to normal range. We included 113 African men (BMI≤25 kg/m(2)) and took anthropometric, biochemical and cardiovascular measures. The blood pressure-leptin relationship was then investigated along quintiles of leptin and within BMI stratified median split (20 kg/m(2)) groups. Blood pressure increased across leptin quintiles 1-3 (p for trend≤0.040), whereas no relationship was observed along quintiles 3 to 5 (p for trend≥0.14) (adjusted for age and waist circumference). Blood pressure was similar in the two BMI median split groups (p≥0.083). In the low BMI group only, blood pressure associated positively with leptin following unadjusted, partial, and full adjustment (systolic blood pressure and diastolic blood pressure: R(2)=0.20-0.27, ß=0.32-0.34, p≤0.009). Decreasing leptin levels are not likely to contribute to hypertension prevalence in the underweight. Rather, in African men with a BMI≤20 kg/m(2), low leptin levels are positively and independently associated with elevated blood pressure, which is not seen at higher BMI (20-25 kg/m(2)). Our findings suggest a differential concentration dependent vascular effect of leptin in underweight and normal weight African men.

8-Oxo-7,8-dihydro-2'-deoxyguanosine, reactive oxygen species and ambulatory blood pressure in African and Caucasian men: the SABPA study.

Various studies indicate a relationship between increased oxidative stress and hypertension, resulting in increased DNA damage and consequent excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG). The aim of this study was to compare urinary 8-oxodG levels in African and Caucasian men and to investigate the association between ambulatory blood pressure (BP) and pulse pressure (PP) with 8-oxodG in these groups. We included 98 African and 92 Caucasian men in the study and determined their ambulatory BP and PP. Biochemical analyses included, urinary 8-oxodG, reactive oxygen species (ROS) (measured as serum peroxides), ferric reducing antioxidant power (FRAP), total glutathione (GSH), glutathione peroxidase (GPx) and glutathione reductase (GR) activity. The African men had significantly higher systolic (SBP) and diastolic blood pressure (DBP) (both p < 0.001). Assessment of the oxidative stress markers indicated significantly lower 8-oxodG levels (p < 0.001) in the African group. The African men also had significantly higher ROS (p = 0.002) with concomitant lower FRAP (p < 0.001), while their GSH levels (p = 0.013) and GR activity (p < 0.001) were significantly higher. Single and partial regression analyses indicated a negative association between urinary 8-oxodG levels with SBP, DBP and PP only in African men. These associations were confirmed in multiple regression analyses (SBP: R(2) = 0.41; ß = -0.25; p = 0.002, DBP: R(2) = 0.30; ß = -0.21; p = 0.022, PP: R(2) = 0.30; ß = -0.19; p = 0.03). Our results revealed significantly lower urinary 8-oxodG in African men, accompanied by a negative association with BP and PP. We propose that this may indicate a dose-response relationship in which increased oxidative stress may play a central role in the up-regulation of antioxidant defence and DNA repair mechanisms.

Cardiometabolic markers to identify cardiovascular disease risk in HIV-infected black South Africans.

BACKGROUND: The prevalence of HIV is the highest in sub-Saharan Africa; South Africa (SA) is one of the most affected countries with the highest number of adults living with HIV infection in the world. Besides the traditional risk factors for cardiovascular disease (CVD) in the general population, in people living with HIV there are specific factors - chronic inflammation, metabolic changes associated with the infection, therapy, and lipodystrophy - that potentially increase the risk for developing CVD. OBJECTIVE: This study proposes a screening discriminant model to identify the most important risk factors for the development of CVD in a cohort of 140 HIV-infected black Africans from the North West Province, SA. METHODS: Anthropometric measures, systolic blood pressure, diastolic blood pressure and the carotid-dorsalis pedis pulse wave velocity were determined. Blood was analysed to determine the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, triglycerides (TGs) and glucose. Partial least squares discriminant analysis was performed as a supervised pattern recognition method. Independent Student's t-tests were further employed to compare the means of risk factors on interval scales; for comparison of categorical risk factors between groups, chi2 tests were used. RESULTS: A TG:HDL-C ratio > or = 1.49, TC:HDL-C ratio > or = 5.4 and an HDL-C level < or = 0.76 mmol/l indicated CVD risk in this cohort of patients living with HIV. CONCLUSION: The results have important health implications for black Africans living with HIV as these lipid levels may be a useful indicator of the risk for CVD.

Evaluation of waist-to-height ratio to predict 5 year cardiometabolic risk in sub-Saharan African adults.

BACKGROUND AND AIMS: Simple, low-cost central obesity measures may help identify individuals with increased cardiometabolic disease risk, although it is unclear which measures perform best in African adults. We aimed to: 1) cross-sectionally compare the accuracy of existing waist-to-height ratio (WHtR) and waist circumference (WC) thresholds to identify individuals with hypertension, pre-diabetes, or dyslipidaemia; 2) identify optimal WC and WHtR thresholds to detect CVD risk in this African population; and 3) assess which measure best predicts 5-year CVD risk. METHODS AND RESULTS: Black South Africans (577 men, 942 women, aged >30years) were recruited by random household selection from four North West Province communities. Demographic and anthropometric measures were taken. Recommended diagnostic thresholds (WC > 80 cm for women, >94 cm for men; WHtR > 0.5) were evaluated to predict blood pressure, fasting blood glucose, lipids, and glycated haemoglobin measured at baseline and 5 year follow up. Women were significantly more overweight than men at baseline (mean body mass index (BMI) women 27.3 ± 7.4 kg/m(2), men 20.9 ± 4.3 kg/m(2)); median WC women 81.9 cm (interquartile range 61-103), men 74.7 cm (63-87 cm), all P < 0.001). In women, both WC and WHtR significantly predicted all cardiometabolic risk factors after 5 years. In men, even after adjusting WC threshold based on ROC analysis, WHtR better predicted overall 5-year risk. Neither measure predicted hypertension in men. CONCLUSIONS: The WHtR threshold of >0.5 appears to be more consistently supported and may provide a better predictor of future cardiometabolic risk in sub-Saharan Africa.

Compromised bioavailable IGF-1 of black men relates favourably to ambulatory blood pressure: The SABPA study.

OBJECTIVES: Insulin-like growth factor-1 (IGF-1) has potent endothelial-protective, anti-platelet and anti-thrombotic activities, and also exerts mitogenic and proliferatory actions on vascular smooth muscle cells. Conflicting reports exist regarding the role of IGF-1 in vascular protection and atherogenesis. We therefore investigated the relationships of ambulatory blood pressure (BP) and carotid intima-media thickness (cIMT) with a range of components of the IGF-1 axis in a bi-ethnic population. METHODS: We included black (N = 86) and white (N = 101) men and measured growth hormone, total IGF-1, insulin-like growth factor binding protein-3 (IGFBP-3), and pregnancy-associated plasma protein-A (PAPP-A) levels. RESULTS: Ambulatory BP was almost 10 mmHg higher in black men (137/88 mmHg versus 128/80 mmHg; both p < 0.001), accompanied by an adverse profile of the IGF-axis for all measured components (all p < 0.01), including reduced bioavailable IGF-1 (IGF-1/IGFBP-3; p = 0.006) and tissue IGF-1 accessibility index as represented by IGF-1.PAPP-A/IGFBP-3 (p < 0.001). Single, partial and multiple regression analyses confirmed an independent inverse association between ambulatory systolic BP and bioavailable IGF-1 in black men (R(2) = 0.24; ß = -0.22; p = 0.035). cIMT was similar in the ethnic groups (p = 0.34), and was negatively associated with bioavailable IGF-1 in white men (R(2) = 0.42; ß = -0.17; p = 0.039) prior to adjustment for γ-glutamyl transferase (R(2) = 0.45; ß = -0.10; p = 0.25). CONCLUSION: Ambulatory systolic BP is inversely related to bioavailable IGF-1 in black men who displayed low IGF-1 concentrations. An inverse relation was found between cIMT and IGF-1 in white men, which disappeared after correction for γ-glutamyl transferase - opposing reports of a detrimental role of IGF-1 in the early stages of atherogenesis.

Differential Changes in Postsynaptic Density Proteins in Postmortem Huntington's Disease and Parkinson's Disease Human Brains.

NMDA and AMPA-type glutamate receptors and their bound membrane-associated guanylate kinases (MAGUKs) are critical for synapse development and plasticity. We hypothesised that these proteins may play a role in the changes in synapse function that occur in Huntington's disease (HD) and Parkinson's disease (PD). We performed immunohistochemical analysis of human postmortem brain tissue to examine changes in the expression of SAP97, PSD-95, GluA2 and GluN1 in human control, and HD- and PD-affected hippocampus and striatum. Significant increases in SAP97 and PSD-95 were observed in the HD and PD hippocampus, and PSD95 was downregulated in HD striatum. We observed a significant increase in GluN1 in the HD hippocampus and a decrease in GluA2 in HD and PD striatum. Parallel immunohistochemistry experiments in the YAC128 mouse model of HD showed no change in the expression levels of these synaptic proteins. Our human data show that major but different changes occur in glutamatergic proteins in HD versus PD human brains. Moreover, the changes in human HD brains differ from those occurring in the YAC128 HD mouse model, suggesting that unique changes occur at a subcellular level in the HD human hippocampus.

The link between vascular deterioration and branched chain amino acids in a population with high glycated haemoglobin: the SABPA study.

Globally the prevalence of non-communicable diseases, such as hypertension and type 2 diabetes, are escalating. Metabolomic studies indicated that circulating branched chain amino acids (BCAAs) are associated with insulin resistance, coronary artery disease and increased risk for cardiovascular events. We aimed to extend the current understanding of the cardiovascular risk associated with BCAAs. We explored whether BCAAs are related to markers of cardiovascular disease in a bi-ethnic population and whether this relationship was influenced by chronic hyperglycaemia. We included 200 African and 209 Caucasian participants, and determined their ambulatory blood pressure and carotid intima-media thickness (cIMT). We analysed blood samples for glycated haemoglobin (HbA1c) and BCAAs. Participants were stratified into two groups according to their HbA1c value using the median cut-off value of 5.6%. Ambulatory BP, cIMT and BCAAs were significantly higher (all p < 0.001) in the high HbA1c group. Single regression analyses indicated significant positive associations of ambulatory blood pressure and cIMT with BCAAs (all p < 0.05) in both the groups. These associations between ambulatory systolic blood pressure (SBP) (r = 0.16, p = 0.035) and cIMT (r = 0.22, p = 0.004) with BCAAs remained in the high HbA1c group after adjusting for age, gender, ethnicity and body mass index (BMI) and were confirmed in multiple regression analyses (ambulatory SBP: R (2) = 0.17, ß = 0.21, p = 0.005 and cIMT: R (2) = 0.30, ß = 0.19, p = 0.003). Our results demonstrate that BCAAs are independently related to ambulatory BP and cIMT in individuals with high HbA1c levels and suggest that potential cardiovascular deterioration accompany the rise in BCAAs in conditions of hyperglycaemia.

Defensive coping facilitates higher blood pressure and early sub-clinical structural vascular disease via alterations in heart rate variability: the SABPA study.

OBJECTIVES: Defensive coping (AC) responses in urban African males have been associated with vascular responsiveness, partly explaining autonomic nervous system dysfunction. We therefore aimed to assess whether AC responses facilitate higher blood pressure and early sub-clinical structural vascular disease via alterations in frequency- and time-domain heart rate variability (HRV) responses. METHODS: We included 355 African and Caucasian men and women without pre-existing atrial fibrillation, aged 45 ± 9 years. Significant interaction on main effects (coping × ethnicity × gender) for left carotid intima media thickness far wall (L-CIMTf) and cross sectional wall area values necessitated selection of AC responders above mean via the Coping Strategy Indicator. We collected B-mode ultrasound L-CIMTf, ambulatory BP and-HRV data. Overnight fasting blood was obtained. RESULTS: Overall, Africans and AC Africans, mostly men, revealed a poorer lifestyle profile, higher prevalence of hypertensive status, disturbed sympathovagal balance and depressed HRV temporal and geometric patterns compared to the Caucasians (P ≤ 0.05). Moderately depressed non-linear and time-domain HRV (SDNN <100 ms) was prevalent in 28% of Africans compared to 11% of Caucasians. A similar trend was shown for the AC African participants (32%) compared to Caucasians (16%). Only depressed HRV time-domain (SDNN: adj. R(2) = 0.34; ß = -0.24; p = 0.08) and vagal-impaired heart rate responses (RMSSD: adj. R(2) = 0.28; ß = -0.28; p < 0.05) were associated with higher blood pressure and early structural vascular changes in AC African men. CONCLUSION: Defensive coping facilitated autonomic nervous system dysfunction, which was associated with higher blood pressure and sub-clinical structural vascular disease in an African male cohort.