Presenting symptoms of acute coronary syndrome in older and younger adults in Trinidad & Tobago

BACKGROUND AND AIM: Acute Coronary Syndrome (ACS) is a major cause of mortality in Trinidad and Tobago. As life expectancy increases, Emergency Departments in Trinidad and Tobago are admitting more older patients (age ≥ 65). Previous studies have demonstrated differences in the presenting symptoms between older and younger patients with ACS. However, to our knowledge, no such work has been done on older patients in the developing world. The aim of this study was to determine the differences in the reported symptoms of ACS between the older patients (age ≥ 65) and younger adults (age 18 – 64) in the ED. The primary objective was to compare the differences in frequency of symptoms of ACS between the older and younger adults. A secondary objective was to determine if differences in reported symptoms also exist between older men and older women. CONCLUSIONS: This study demonstrates significant differences in symptoms between older and younger patients as well as between older men and women. Clinical assessment of older patients with ACS should be tailored to their common presenting features. Further work is needed to develop a clinical assessment tool for older patients with ACS that accounts for differences in presentation

Age changes in the structure of human Atrioventricular annuli

Atrioventricular annuli are important in hemodynamic stability and support to tricuspid and mitral valves. Anatomical features of the annuli such as circumference, organization of connective tissue fibers, myocardium and cellularity may predispose to annular insufficiency and valvular incompetence. These pathologies increase with age and are more common in females, although the anatomical basis for this disparity remains unclear. This study therefore aimed to investigate age-related changes in the structure of human atrioventricular annuli. One hundred and one hearts (48males, 53 females) from subjects (15 to 60 years) were studied in three age groups (≤ 20 yrs, 21-39 yrs and 40-60 yrs). Annular circumferences were measured and corrected for heart weight. Routine histology was carried out on 21 hearts. Differences in annular circumference between the age groups were determined using one-way ANOVA while gender differences were determined using independent Students’t-test. Overall, females had significantly larger annular circumference than males after correcting for heart weight (p ≤0.05). The annular circumference generally increased with age however there was a significant increase in the 21-39 year age group (p ≤0.05). Microscopically, myocardium was consistently present in males but absent in females except in one specimen. The collagen fiber density increased with age in both gender as the fibers became more irregular. The annular cellularity, elasticity and myocardial content also declined with increasing age. The significantly wider annular circumference in the 21-39 year age group is clinically important as wider circumference is associated with decreased heart valve co-aptation and valvular incompetence. This may suggest an earlier predisposition to this pathology in the study population. The age-related decrease in annular cellularity, elasticity and myocardial content may explain the higher incidence of valvular incompetence with increasing age.Key words: Atrioventricular annuli; Age changes; Valve incompetence

Sternal foramina and variant xiphoid morphology in a Kenyan population

Sternal foramina may pose a great hazard during sternal puncture, due to inadvertent cardiac or great vessel injury. They can also be misinterpreted as osteolytic lesions in cross-sectional imaging of the sternum. On the other hand, variant xiphoid morphology such as bifid, duplicated, or trifurcated may be mistaken for fractures during imaging. The distribution of these anomalies differs between populations, but data from Africans is scarcely reported. This study therefore aimed to investigate the distribution and frequency of sternal foramina and variant xiphoid morphology in a Kenyan population. Eighty formalin-fixed adult sterna (42 males [M], 38 females [F]) of age range 18–45 years were studied during dissection at the Department of Human Anatomy, University of Nairobi. Soft tissues were removed from the macerated sterna by blunt dissection and foramina recorded in the manubrium, body, and xiphoid process. The xiphisternal ending was classified as single, bifurcated (2 xiphoid processes with a common stem), or duplicated (2 xiphoid processes with separate stems). Results were analysed using SPSS version 17.0. Foramina were present in 11 specimens (13.8%): 7 M, 4 F. The highest frequency was in the sternal body (n = 9), where they predominantly occurred at the 5th intercostal segment. Xiphoid foramina were present in 2 specimens (both males) (2.5%), while manubrial foramen was not encountered. The xiphisternum ended as a single process in 64 cases (34 M, 30 F) (80%). It bifurcated in 10 cases (5 M, 5 F) (12.5%), and duplicated in 6 cases (4 M, 2 F) (7.5%). There were no cases of trifurcation. Sternal foramina in Kenyans vary in distribution and show higher frequency than in other populations. These variations may complicate sternal puncture, and due caution is recommended. The variant xiphisternal morphology may raise alarm for xiphoid fractures and may therefore be considered a differential

Eliminating Human African Trypanosomiasis: Where Do We Stand and What Comes Next>

While the number of new detected cases of HAT is falling, say the authors, sleeping sickness could suffer the "punishment of success," receiving lower priority by public and private health institutions

Structure and dynamics of nanoconfined water and aqueous solutions

This review is devoted to discussing recent progress on the structure, thermodynamic, reactivity, and dynamics of water and aqueous systems confined within different types of nanopores, synthetic and biological. Currently, this is a branch of water science that has attracted enormous attention of researchers from different fields interested to extend the understanding of the anomalous properties of bulk water to the nanoscopic domain. From a fundamental perspective, the interactions of water and solutes with a confining surface dramatically modify the liquid's structure and, consequently, both its thermodynamical and dynamical behaviors, breaking the validity of the classical thermodynamic and phenomenological description of the transport properties of aqueous systems. Additionally, man-made nanopores and porous materials have emerged as promising solutions to challenging problems such as water purification, biosensing, nanofluidic logic and gating, and energy storage and conversion, while aquaporin, ion channels, and nuclear pore complex nanopores regulate many biological functions such as the conduction of water, the generation of action potentials, and the storage of genetic material. In this work, the more recent experimental and molecular simulations advances in this exciting and rapidly evolving field will be reported and critically discussed

New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.

Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes

Arm-in-cage testing of natural human-derived mosquito repellents

BACKGROUND: Individual human subjects are differentially attractive to mosquitoes and other biting insects. Previous investigations have demonstrated that this can be attributed partly to enhanced production of natural repellent chemicals by those individuals that attract few mosquitoes in the laboratory. The most important compounds in this respect include three aldehydes, octanal, nonanal and decanal, and two ketones, 6-methyl-5-hepten-2-one and geranylacetone [(E)-6,10-dimethylundeca-5,9-dien-2-one]. In olfactometer trials, these compounds interfered with attraction of mosquitoes to a host and consequently show promise as novel mosquito repellents. METHODS: To test whether these chemicals could provide protection against mosquitoes, laboratory repellency trials were carried out to test the chemicals individually at different concentrations and in different mixtures and ratios with three major disease vectors: Anopheles gambiae, Culex quinquefasciatus and Aedes aegypti. RESULTS: Up to 100% repellency was achieved depending on the type of repellent compound tested, the concentration and the relative composition of the mixture. The greatest effect was observed by mixing together two compounds, 6-methyl-5-hepten-2-one and geranylacetone in a 1:1 ratio. This mixture exceeded the repellency of DEET when presented at low concentrations. The repellent effect of this mixture was maintained over several hours. Altering the ratio of these compounds significantly affected the behavioural response of the mosquitoes, providing evidence for the ability of mosquitoes to detect and respond to specific mixtures and ratios of natural repellent compounds that are associated with host location. CONCLUSION: The optimum mixture of 6-methyl-5-hepten-2-one and geranylacetone was a 1:1 ratio and this provided the most effective protection against all species of mosquito tested. With further improvements in formulation, selected blends of these compounds have the potential to be exploited and developed as human-derived novel repellents for personal protection

Mutations in HNF1A Result in Marked Alterations of Plasma Glycan Profile

A recent genome-wide association study identified hepatocyte nuclear factor 1-α (HNF1A) as a key regulator of fucosylation. We hypothesized that loss-of-function HNF1A mutations causal for maturity-onset diabetes of the young (MODY) would display altered fucosylation of N-linked glycans on plasma proteins and that glycan biomarkers could improve the efficiency of a diagnosis of HNF1A-MODY. In a pilot comparison of 33 subjects with HNF1A-MODY and 41 subjects with type 2 diabetes, 15 of 29 glycan measurements differed between the two groups. The DG9-glycan index, which is the ratio of fucosylated to nonfucosylated triantennary glycans, provided optimum discrimination in the pilot study and was examined further among additional subjects with HNF1A-MODY (n = 188), glucokinase (GCK)-MODY (n = 118), hepatocyte nuclear factor 4-α (HNF4A)-MODY (n = 40), type 1 diabetes (n = 98), type 2 diabetes (n = 167), and nondiabetic controls (n = 98). The DG9-glycan index was markedly lower in HNF1A-MODY than in controls or other diabetes subtypes, offered good discrimination between HNF1A-MODY and both type 1 and type 2 diabetes (C statistic ≥ 0.90), and enabled us to detect three previously undetected HNF1A mutations in patients with diabetes. In conclusion, glycan profiles are altered substantially in HNF1A-MODY, and the DG9-glycan index has potential clinical value as a diagnostic biomarker of HNF1A dysfunction