Influence of ankle loading on the relationship between temporal pressure and motor coordination during a whole-body paired task

We investigated whether ankle loading modifies the relationship between temporal pressure and motor coordination during a whole-body paired task. Eight young healthy adults standing in an erect posture performed multiple series of simultaneous rapid leg flexions paired with ipsilateral index finger extensions. They repeated the task ten times in three load conditions: unloaded, loaded (where additional 5-kg inertia was attached to the ankles), and post-loaded (immediately following the loaded condition). These conditions were conducted in two blocks of temporal pressure: self-initiated (SI) versus reaction time (RT). When participants were unloaded, the results showed that index finger extension preceded swing heel-off in RT, and conversely in SI. By contrast, when the participants were loaded, swing heel-off preceded index finger extension in both SI and RT, showing that loading modified the relationship between temporal pressure and movement synchronization in RT only. However, loading did not induce any increase in the error of synchronization. Furthermore, in both the unloaded and loaded conditions, the duration of “anticipatory postural adjustments” (APA) was shorter when the temporal pressure was increased. Interestingly, the shorter APA duration was compensated by an increase in APA amplitude. Thus, loading did not modify the relationship between temporal pressure and anticipatory postural dynamics. Post-loaded and unloaded conditions produced the same results. These results show that the central nervous system optimally adapts the relationship between temporal pressure and motor coordination to transitory changes in the mechanical properties of the lower limbs, here due to ankle loading.     

Ultrasound Effect on Neural Differentiation of Gingival Stem/Progenitor Cells

Dental pulp loss due to caries or pulpitis can affect the longevity of teeth. Dental pulp tissue engineering necessitates the use of progenitor cells that has the potential to differentiate into neural, vascular and odontoblasts like cells. Previous reports have shown that human gingival progenitor cells (HGPCs) can be differentiated into different cell types; however neural differentiation of these cells, to the best of our knowledge, has not been reported. Low intensity pulsed ultrasound (LIPUS) has been reported to enhance cell differentiation. The aims of this study were (1) to explore the potential neural differentiation of HGPCs and (2) to investigate the effect of LIPUS on the differentiation of HGPCs when incubated under neuroinductive conditions. The HGPCs were isolated from human interdental papilla proximal to the premolar teeth that were extracted for orthodontic purpose. The HGPCs were induced to differentiate into neural lineage using a neuroinductive culture medium. HGPCs were divided into four groups; control group, neuro-induction (NI) group, ultrasound group (LIPUS), and a combined NI+LIPUS group. HGPCs were harvested for immunostaining and q-PCR after 1 day. Immunostaining for neuron specific antigens and q-PCR suggested that HGPCs can be differentiated into neural lineage and that selected neurodifferentiation markers can be enhanced by LIPUS.     

Visual pigments and opsin expression in the juveniles of three species of fish (rainbow trout,zebrafish, and killifish) following prolonged exposure to thyroid hormone or retinoic acid

Thyroid hormone (TH) and retinoic acid (RA) are powerful modulators of photoreceptor differentiation during vertebrate retinal development. In the embryos and young juveniles of salmonid fishes and rodents, TH induces switches in opsin expression within individual cones, a phenomenon that also occurs in adult rodents following prolonged (12 week) hypothyroidism. Whether changes in TH levels also modulate opsin expression in the differentiated retina of fish is unknown. Like TH, RA is essential for retinal development, but its role in inducing opsin switches, if any, has not been studied. Here we investigate the action of TH and RA on single‐cone opsin expression in juvenile rainbow trout, zebrafish, and killifish and on the absorbance of visual pigments in rainbow trout and zebrafish. Prolonged TH exposure increased the wavelength of maximum absorbance (λ_max) of the rod and the medium (M, green) and long (L, red) wavelength visual pigments in all fish species examined. However, unlike the opsin switch that occurred following TH exposure in the single cones of small juvenile rainbow trout (alevin), opsin expression in large juvenile rainbow trout (smolt), zebrafish, or killifish remained unchanged. RA did not induce any opsin switches or change the visual pigment absorbance of photoreceptors. Neither ligand altered cone photoreceptor densities. We conclude that RA has no effect on opsin expression or visual pigment properties in the differentiated retina of these fishes. In contrast, TH affected both single‐cone opsin expression and visual pigment absorbance in the rainbow trout alevin but only visual pigment absorbance in the smolt and in zebrafish. The latter results could be explained by a combination of opsin switches and chromophore shifts from vitamin A1 to vitamin A2. J. Comp. Neurol. 522:98–117, 2014. © 2013 Wiley Periodicals, Inc.     

Smoking prevention and cessation in the Africa and Middle East region: a consensus draft guideline for healthcare providers--executive summary

Despite the abundance of scientific evidence confirming the health consequences of smoking and other forms of tobacco use, the tobacco epidemic remains an important public health problem and by 2030 it is predicted that more than 80% of tobacco deaths will be in developing countries. In Africa and the Middle East, many local factors contribute to the initiation and maintenance of tobacco use. Although efforts to reduce the mortality and morbidity associated with smoking and tobacco dependence are underway, there is a need for guidance on how to utilize appropriate tobacco control policies and psychology- and pharmacology-based therapies to counter tobacco dependence as recommended by the Framework Convention on Tobacco Control (FCTC). A group of tobacco cessation experts from public health services and/or academic institutions in Africa and the Middle East participated in a series of four meetings held in Cairo, Cape Town, and Dubai between May 2008 and February 2011 to develop a draft guideline tailored to their region. This article provides the background to the development of this draft smoking cessation guideline and discusses how the recommendations can be implemented and progress monitored to promote both primary prevention and cessation of tobacco use within our countries. The draft guideline for Africa and the Middle East provides an important resource in combating the devastating effects of tobacco use in these regions which can be further localized through engagement with local stakeholders in the countries of the region.     

Clinical Utility of the Neuropsychological Assessment Battery (NAB) after Unilateral Stroke

The NAB is a comprehensive battery assessing five cognitive domains (Attention, Language, Memory, Spatial, Executive Function). Despite the advantage of co-normative domain data, its clinical utility is not well established because few studies have reported full-battery findings. The aim of this study was to determine if the NAB was sensitive to well documented hemispheric differences in language and spatial skills after unilateral stroke. We compared demographically matched control participants (n = 52) and individuals after left (LHD, n = 36) or right (RHD, n = 33) hemisphere damage due to stroke on the NAB, parts of the Western Aphasia Battery, and traditional visuospatial tasks. Both stroke groups showed impaired NAB Attention, Spatial, and Executive Functions relative to controls, while the LHD group was more impaired than control and RHD groups on Language and Memory modules. LHD patients with aphasia on traditional measures performed worse than control and non-aphasic LHD patients on all NAB domains. RHD patients with spatial impairment on traditional measures performed worse than controls, but not RHD patients without spatial impairment, on the NAB Spatial domain. Findings suggest the NAB is generally comparable to traditional language and visuospatial measures, and it sufficiently detects attention and executive deficits.     

Aspiration thrombectomy during primary percutaneous coronary intervention as adjunctive therapy to early (in-ambulance) abciximab administration in patients with acute ST elevation myocardial infarction: an analysis from Leiden MISSION! acute myocardial infarction treatment optimization program

Background: The benefits of early abciximab administration and thrombus aspiration in ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PPCI) have previously been elaborated. However, whether there is an adjunctive effect of thrombus aspiration among STEMI patients, with angiographic evidence of thrombus, receiving early prehospital abciximab remains unclear. Methods: In the context of a fixed protocol for PPCI, 158 consecutive patients with STEMI were enrolled, in whom abciximab was started early before hospital arrival (in‐ambulance); 79 patients who had PPCI with thrombus aspiration (thrombectomy‐facilitated PCI group), were compared to 79 who had PPCI without thrombus aspiration (conventional PCI group) in a prospective nonrandomized study. The primary end‐point was complete ST‐segment resolution within 90 minutes. Secondary end points included distal embolization, enzymatic infarct size as well as left ventricular ejection fraction (LVEF) assessed by gated single‐photon emission computed tomography. Major adverse cardiac events (MACEs) were evaluated up to 12 months. Results: Both groups were comparable for baseline characteristics. ST‐segment resolution was significantly higher in the thrombectomy‐facilitated group (P = 0.002), and multivariate analysis identified thrombectomy as an independent predictor of ST‐segment resolution (OR = 9.4, 95% CI = 2.6–33.5, P = 0.001). Distal embolization was higher in the conventional PCI group among patients with higher thrombus grades. No difference was observed between both groups in infarct size assessed by peak creatine kinase (p = 0.689) and peak Tn‐T levels (P = 0.435). Also, the LVEF at 3 months was similar (P = 0.957). At 12 month clinical follow‐up, thrombus aspiration was, however, associated with reduced all‐cause mortality (log‐rank p = 0.032). Conclusion: Among STEMI patients treated with PPCI and in‐ambulance abciximab, it appears that a selective strategy of thrombus aspiration still has additive benefit. (J Interven Cardiol 2012;25:1–9)