Articles: human.
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Comparative Study
Color-detection thresholds in rhesus macaque monkeys and humans.
Macaque monkeys are a model of human color vision. To facilitate linking physiology in monkeys with psychophysics in humans, we directly compared color-detection thresholds in humans and rhesus monkeys. Colors were defined by an equiluminant plane of cone-opponent color space. ⋯ These asymmetries may reflect differences in retinal circuitry for S-ON and S-OFF. At plateau performance, the two species also had similar detection thresholds for all colors, although monkeys had shorter reaction times than humans and slightly lower thresholds for colors that modulated L/M cones. We discuss whether these observations, together with previous work showing that monkeys have lower spatial acuity than humans, could be accounted for by selective pressures driving higher chromatic sensitivity at the cost of spatial acuity amongst monkeys, specifically for the more recently evolved L − M mechanism.
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Developmental neocortical malformations resulting from abnormal neurogenesis, disturbances in programmed cell death, or neuronal migration disorders may cause a long-term hyperexcitability. Early generated Cajal-Retzius and subplate neurons play important roles in transient cortical circuits, and structural/functional disorders in early cortical development may induce persistent network disturbances and epileptic disorders. In particular, depolarizing GABAergic responses are important for the regulation of neurodevelopmental events, like neurogenesis or migration, while pathophysiological alterations in chloride homeostasis may cause epileptic activity. ⋯ The neocortical focus may be surrounded by widespread molecular, structural, and functional disturbances, which are difficult to recognize with imaging technologies. However, modern imaging and electrophysiological techniques enable focused hypotheses of the neocortical epileptogenic zone, thus allowing more specific epilepsy surgery. Focal cortical malformation can be successfully removed with minimal rim, close to or even within eloquent cortex with a promising risk-benefit ratio.
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Acta Anaesthesiol Scand · Jan 2014
Infusion rate and plasma volume expansion of dextran and albumin in the septic guinea pig.
Intravenous fluid treatment of hypovolaemia in states of increased capillary permeability, e.g. sepsis, is often accompanied by adverse oedema formation. A challenge is therefore to achieve and maintain normovolaemia using as little plasma volume substitution as possible to minimise interstitial oedema. In the present study, we evaluated the importance of infusion rate for the plasma volume expanding effects of 6% dextran 70 and 5% human albumin in a guinea pig sepsis model. ⋯ The study performed on a guinea pig sepsis model showed that the plasma volume expanding effects of fixed volumes of 6% dextran 70 and 5% albumin were greater when given at a slow than at a fast infusion rate.
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Am. J. Respir. Crit. Care Med. · Jan 2014
Clinical TrialLong-Term Facilitation of Ventilation in Humans with Chronic Spinal Cord Injury.
Intermittent stimulation of the respiratory system with hypoxia causes persistent increases in respiratory motor output (i.e., long-term facilitation) in animals with spinal cord injury. This paradigm, therefore, has been touted as a potential respiratory rehabilitation strategy. ⋯ Ventilatory long-term facilitation can be evoked by brief periods of hypoxia in humans with chronic spinal cord injury. Thus, intermittent hypoxia may represent a strategy for inducing respiratory neuroplasticity after declines in respiratory function that are related to neurological impairment. Clinical trial registered with www.clinicaltrials.gov (NCT01272011).
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Diabetol Metab Syndr · Jan 2014
The goal of blood pressure in the hypertensive patient with diabetes is defined: now the challenge is go from recommendations to practice.
The recent Latin American and European guidelines published this year has proposed as a goal for blood pressure control in patients with diabetes type 2 a value similar or inferior to 140/90 mmHg. High blood pressure is the leading cause of cardiovascular diseases and deaths globally. Although once hypertension is detected, 80% of individuals are on a pharmacologic therapy only a minority is controlled. ⋯ As reviewed in this article many clinical trials have demonstrated not only the lack of benefits of lowering the BP below 130/80 mmHg, but also the J-shaped relationship in DM patients. Overall we discuss the importance of define the group of patients in whom significant BP reduction could be particularly dangerous and, on the other hand, those with a high risk of stroke who could benefit most from an intensive hypotensive therapy. In any case, the big challenge now is avoid the therapeutic inertia (leaving diabetic patients with BP values of 140/90 mmHg or higher) at all costs, as this would lead to an unacceptable toll in terms of human lives, suffering, and socioeconomic costs.