Variations in regional strain under different afterload conditions may help to identify is-chemic myocardium

INTRODUCTION: Acute coronary syndromes are a major health problem worldwide. The Speckle Tracking Imaging has been proposed as ad-junctive for diagnosis and prognosis purposes in the context of NSTE-ACS. Purpose: We sought to determine the regional myocardial strain in ischemic versus non-ischemic segments in subjects with NSTE-ACS, before and during acute pressure overload. METHODS: Data from 2D-echocardiography were obtained from 21 patients (mean age, 50 ± 10 years) undergoing cinecoronariography for NSTE-ACS indications. A blinded observer performed an offline analysis to obtain the Systolic Positive Peak (P), Systolic Peak Strain (S), Peak Strain (G) and Time to Peak Strain (TTP) of each segment acquired before and during pressure overload-induced by left hand-grip (42± 8 Kg) combined with simultaneous pneumatic constriction of the right arm and both lower limbs. Moreover, LVEF and GLS were also calculated. A second blinded observer labelled the ischemic regions according to AHA-16 Bull's eye using data from cinecoronariography. RESULTS: The handgrip manuever caused mild reductions in the median LVEF (56 %; IQR 48 -58% vs 54%; IQR 51-56%) as well as the median GLS (-17%; IQR-19%-15% vs -16%; IQR -19-15%). For the analysis of regional myocardial function, we obtained 360 segments (29% labelled as ischemic) with optimal tracking quality. Mean regional strain changes during pressure overload were significantly different in ischemic vs non-ischemic segments for Peak S (1,07% x -0.5%; p-value <0,01) and Peak G (0.85% x -0.65%; p-value < 0.01) (Table). Notably, however, we found marked increases in the systolic deformation, restricted to the apical ischemic segments during pressure overload (Figure). CONCLUSIONS: Our data point to a distinct increase in the systolic deformation of the apical segments in contrast to the overall reductions in the GLS and EF in the ischemic left ventricle.

Melanin-concentrating hormone projections to areas involved in somatomotor responses.

The lateral hypothalamic area (LHA) participates in the integration of sensory information and somatomotor responses associated with hunger and thirst. Although the LHA is neurochemically heterogeneous, a particularly high number of cells express melanin-concentrating hormone (MCH), which has been reported to play a role in energy homeostasis. Treatment with MCH increases food intake, and MCH mRNA is overexpressed in leptin-deficient (ob/ob) mice. Mice lacking both MCH and leptin present reduced body fat, mainly due to increased resting energy expenditure and locomotor activity. Dense MCH innervation of the cerebral motor cortex (MCx) and the pedunculopontine tegmental nucleus (PPT), both related to motor function, has been reported. Therefore, we postulated that a specific group of MCH neurons project to these areas. To investigate our hypothesis, we injected retrograde tracers into the MCx and the PPT of rats, combined with immunohistochemistry. We found that 25% of the LHA neurons projecting to the PPT were immunoreactive for MCH, and that 75% of the LHA neurons projecting to the MCx also contained MCH. Few MCH neurons were found to send collaterals to both areas. We also found that 15% of the incerto-hypothalamic neurons projecting to the PPT expressed MCH immunoreactivity. Those neurons preferentially innervated the rostral PPT. In addition, we observed that the MCH neurons express glutamic acid decarboxylase mRNA, a gamma-aminobutyric acid (GABA) synthesizing enzyme. We postulate that MCH/GABA neurons are involved in the inhibitory modulation of the innervated areas, decreasing motor activity in states of negative energy balance.

Degree of threat to the biological diversity in the Ilha Grande State Park (RJ) and guidelines for conservation

The State Park of Ilha Grande is only a part (5,594 hectares) of the entire island (19,300 hectares) which is located off the south coast of Rio de Janeiro state, between the cities of Mangaratiba and Angra dos Reis. Approximately half of the Park area (47 percent) is covered by dense Atlantic forest. The secondary forest growth is in a process of ecological succession close to attaining maturity (43 percent) and the remaining part (10 percent) is composed of human-altered areas (1 percent), rocky outcrops with herbaceous vegetation (7 percent), mangroves and beaches (2 percent). The fauna is well represented but already shows signs of degradation with introduced species. The analysis of the degree of threat has shown that the dense forest habitat has a relatively stable status of conservation while the secondary forest, the mangrove and the herbaceous vegetation on rocky outcrops (and their fauna) are categorized as vulnerable. The area altered by human occupation is considered threatened. Since the coastal area where Ilha Grande is located is well known for its beautiful scenery (known as the green coast, because of the contrast between the ocean and the Atlantic forest covering the Serra do Mar mountain chain). There is a strong possibility for tourism to become the means in which to achieve economic sustainability for conservation. Contradictorily, tourism is also the major threat to local biodiversity and its landscape units. Because tourism is not organized and controlled, during high season the numbers grow above local capacity, giving rise to a proliferation of hotels, guesthouses and camping grounds. The resulting untreated open sewage, random garbage disposal and other harmful activities form the major threats to biodiversity

Tracking Regional Background in a Haze Attribution Experiment.

Emissions from distant source areas are often imagined to provide a steady background to the emissions of whatever local sources are being studied. As part of Project MOHAVE in summer 1992, several air mass markers and an injected stack tracer were measured hourly near the Grand Canyon. Observed haze events generally coincided with transients in methylchloroform and water vapor, which we interpret as endemic tags for air from southern California and the subtropics. The results depict a dynamic regional background.