Near-Infrared Spectroscopy and Its Potential for Point-Of-Care Testing

Point-of-care or ‘near-patient’ testing has received attention in recent years for its usefulness in rapid and reliable delivery of healthcare to a patient in a variety of clinical settings. Near-infrared spectroscopy (NIRS)-derived optical biomarkers (e.g., tissue oxygen saturation) have been utilized to monitor tissue vascularity and oxygenation status continuously in normal and patient populations. Despite its ease of use and modest cost, the NIRS modality is still not at point-of-care use in the healthcare sector as extensively as other physiological modalities such as Pulse Oximetry. This short communication examines the case for point-of-care testing with two examples of FDA-approved NIRS systems, and discusses the feasibility and implementation of the NIRS modality as a point-of-care technology

Genetic variation of CYP2C19 affects both pharmacokinetic and pharmacodynamic responses to clopidogrel but not prasugrel in aspirin-treated patients with coronary artery disease

The metabolic pathways leading to the formation of prasugrel and clopidogrel active metabolites differ. We hypothesized that decreased CYP2C19 activity affects the pharmacokinetic and pharmacodynamic response to clopidogrel but not prasugrel. Ninety-eight patients with coronary artery disease (CAD) taking either clopidogrel 600 mg loading dose (LD)/75 mg maintenance dose (MD) or prasugrel 60 mg LD/10 mg MD were genotyped for variation in six CYP genes. Based on CYP genotype, patients were segregated into two groups: normal function (extensive) metabolizers (EM) and reduced function metabolizers (RM). Plasma active metabolite concentrations were measured at 30 min, 1, 2, 4, and 6 h post-LD and during the MD period on Day 2, Day 14, and Day 29 at 30 min, 1, 2, and 4 h. Vasodilator-stimulated phosphoprotein (VASP) and VerifyNow (TM) P2Y12 were measured predose, 2, and 24 +/- 4 h post-LD and predose during the MD period on Day 14 +/- 3 and Day 29 +/- 3. For clopidogrel, active metabolite exposure was significantly lower (P = 0.0015) and VASP platelet reactivity index (PRI, %) and VerifyNow (TM) P2Y(12) reaction unit (PRU) values were significantly higher (P < 0.05) in the CYP2C19 RM compared with the EM group. For prasugrel, there was no statistically significant difference in active metabolite exposure or pharmacodynamic response between CYP2C19 EM and RM. Variation in the other five genes demonstrated no statistically significant differences in pharmacokinetic or pharmacodynamic responses. Variation in the gene encoding CYP2C19 in patients with stable CAD contributes to reduced exposure to clopidogrel's active metabolite and a corresponding reduction in P2Y(12) inhibition, but has no significant influence on the response to prasugrel

Data from: Obesity and the role of short duration submaximal work on cardiovascular and cerebral hemodynamics

The objective of this study was to compare gas exchange, cardiac and cerebral hemodynamic responses between 10 non-obese and 10 obese men during submaximal work. With the increasing prevalence of obesity, there is a need to understand the impact of obesity on work-induced responses. Participants completed a step-wise incremental cycling until they reached 60% of their age-predicted maximum heart rate. Gas exchange, cardiac and pre-frontal cortex hemodynamic responses were simultaneously measured during rest, work, and recovery. The non-obese group reached ~43% of their predicted maximal aerobic capacity as compared to ~34% in the obese group, with the non-obese working at a relatively higher workload and for more duration than the obese. The obese had elevated baseline heart rate and reduced whole-body oxygen uptake per body weight at baseline and task termination. Other cardiac and cerebral responses, although increased from baseline, were similar between groups during submaximal effort. In the obese, during recovery oxygen uptake and heart-rate recovery were slowest; cardiac output and rate pressure product were greatest, and left ventricle ejection time was shortest. However, both groups exhibited similar cerebral hemodynamics during recovery. These finding imply that, irrespective of their low aerobic fitness, obesity does not impair myocardial performance and cerebrovascular function during graded submaximal work, however, recovery from a short duration of work was influenced by their fitness level. Since a majority of activities of daily living are performed at individual’s submaximal level, understanding influence of obesity on submaximal work is critical

Oxygenation trends in vastus lateralis muscle during incremental and intense anaerobic cycle exercise in young men and women

A presbiopia é uma alteração fisiológica decorrente do envelhecimento que atinge biliões de pessoas em todo o mundo. A sua base fisiopatológica permanece controversa contudo a teoria de Helmholtz é a mais aceite pela comunidade científica. A presbiopia afeta o dia a dia dos indivíduos pelo que a sua correção é de extrema importância para melhorar a sua qualidade de vida. São várias as correções para a presbiopia, desde a utilização de óculos de leitura, aos tratamentos cirúrgicos. Todos os métodos de correção apresentam vantagens e desvantagens pelo que a sua análise é importante para uma escolha mais conscienciosa para cada indivíduo. Em suma, apesar dos inúmeros avanços médicos e tecnológicos, ainda não existe um método universalmente aceite pela comunidade médica para a correção da presbiopia, dado que os diferentes tratamentos apresentam diferentes vantagens para diferentes tipos de indivíduos. Conclui-se assim, após esta revisão bibliográfica, que a melhor correção para a presbiopia está dependente do indivíduo em causa.Presbyopia is a physiological change associated with aging which affects billions of people around the world. Although the pathophysiological of presbyopia remains controversial the Helmholtz theory is, still, the most accepted by the scientific community. Actually, as this problem affects the patients in all daily activities, the treatment of presbyopia is very important to improve their quality of life. There are several treatments for presbyopia, which include pharmacological treatments, reading glasses, contact lens and surgical treatments. All these treatments have advantages and disadvantages, that’s why the critical analysis of these parameters is important in order to choose carefully the best treatment for each patient. Concluding despite the numerous medical and technological advances, there is no treatment universally accepted by the medical community. This disagreement occurs due to the different types of presbyopia treatment which have various advantages and disadvantages according to the patients. In a nutshell, according to this literature review, the best treatment for presbyopia depends the patient

Cycling Cardiorespiratory Responses

Cardiorespiratory responses measured during a submaximal cycling task to 60% of age-predicted maximum heart rate. Measurements were made using a Cosmed k4b2 portable system

Summary of participants’ demographic and anthropometric characteristics in mean (standard deviation).

<p>Summary of participants’ demographic and anthropometric characteristics in mean (standard deviation).</p

Obesity and the Role of Short Duration Submaximal Work on Cardiovascular and Cerebral Hemodynamics - Fig 3

<p>Prefrontal cortex oxygenated hemoglobin (HbO₂; (a) left side, (b) right side) and total oxygenation index (TOI; (c) left side, (d) right side) in obese and non-obese groups during incremental submaximal cycling.</p