Evidence for low‐level hybridization between two allochronic populations of the pine processionary moth,Thaumetopoea pityocampa (Lepidoptera: Notodontidae)

Divergence between populations sharing the same habitat can be initiated by different reproductive times, leading to allochronic differentiation. A spatially localized allochronic summer population (SP) of the pine processionary moth Thaumetopoea pityocampa, recently discovered in Portugal, occurs in sympatry with the local winter population (WP). We examined the level of genetic differentiation between the two populations and estimated the current gene flow within the spatial framework of their co‐occurrence. Mitochondrial data indicated that the two sympatric populations were genetically closer than other WP populations. Conversely, microsatellite genotyping uncovered greater differentiation between the two sympatric populations than between allopatric ones. While male trapping confirmed that reproduction of SP and WP occurred at distinct times, clustering approaches demonstrated the presence of a few LateSP individuals emerging within the WP flight period, although genetically identified as SP. We also identified rare recent hybridization events apparently occurring mainly in the margins of the current SP range. The ongoing gene flow detected between the ancestral and the emerging allochronic populations revealed an incomplete reproductive isolation, which must therefore be taken into account and integrated with studies focussed on ecological drivers, so that a complete understanding of the ongoing speciation process might be achieved.     

Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload

We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.     

The Effects of Hyperbaric Oxygen Therapy on Post-Training Recovery in Jiu-Jitsu Athletes

Objectives

The present study aimed to evaluate the effects of using hyperbaric oxygen therapy during post-training recovery in jiu-jitsu athletes.

Methods

Eleven experienced Brazilian jiu-jitsu athletes were investigated during and following two training sessions of 1h30min. Using a cross-over design, the athletes were randomly assigned to passive recovery for 2 hours or to hyperbaric oxygen therapy (OHB) for the same duration. After a 7-day period, the interventions were reversed. Before, immediately after, post 2 hours and post 24 hours, blood samples were collected to examine hormone concentrations (cortisol and total testosterone) and cellular damage markers [creatine kinase (CK), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH)]. Moreover, the rating of perceived exertion (RPE) and recovery (RPR) scales were applied.

Results

Final lactate [La] values (control: 11.9 ± 1.4 mmol/L, OHB: 10.2 ± 1.4 mmol/L) and RPE [control: 14 (13–17 a.u.), OHB: 18 (17–20 a.u.)] were not significantly different following the training sessions. Furthermore, there was no difference between any time points for blood lactate and RPE in the two experimental conditions (P>0.05). There was no effect of experimental conditions on cortisol (F_1,20 = 0.1, P = 0.793, η² = 0.00, small), total testosterone (F_1,20 = 0.03, P = 0.877, η² = 0.00, small), CK (F_1,20 = 0.1, P = 0.759, η² = 0.01, small), AST (F_1,20 = 0.1, P = 0.761, η² = 0.01, small), ALT (F_1,20 = 0.0, P = 0.845, η² = 0.00, small) or LDH (F_1,20 = 0.7, P = 0.413, η² = 0.03, small). However, there was a difference between the two experimental conditions in RPR with higher values at post 2 h and 24 h in OHB when compared to the control condition (P<0.05).

Conclusions

Thus, it can be concluded that OHB exerts no influence on the recovery of hormonal status or cellular damage markers. Nonetheless, greater perceived recovery, potentially due to the placebo effect, was evident following the OHB condition.     

Impact of Renal Sympathetic Denervation on Left Ventricular Structure and Function at 1-Year Follow-Up

Background

Catheter-based sympathetic renal denervation (RDN) is a recent therapeutic option for patients with resistant hypertension. However, the impact of RDN in left ventricular (LV) mass and function is not completely established. Our aim was to evaluate the effects of RDN on LV structure and function (systolic and diastolic) in patients with resistant hypertension (HTN).

Methods and Results

From a single centre prospective registry including 65 consecutive patients with resistant HTN submitted to RDN between July-2011 and April-2015, 31 patients with baseline and 1-year follow-up echocardiogram were included in this analysis. Mean age was 65±7 years, 48% were males, 71% had type 2 diabetes. Most had hypertension lasting for more than 10 years (90%), and were being treated with a median number of 6 anti-hypertensive drugs, including 74% on spironolactone. At 1-year, there was a significant decrease both on office SBP (176±24 to 149±13mmHg, p<0.001) and DBP (90±14 to 79±11mmHg, p<0.001), and also in 24h ABPM SBP (150±20 to 132±14mmhg, p<0.001) and DBP (83±10 to 74±9mmHg, p<0.001). There was also a significant decrease in LV mass from 152±32 to 136±34g/m² (p<0.001), an increase in LV end diastolic volume (93±18 to 111±27 mL, p = 0.004), an increase in LV ejection fraction (65±9 to 68±9%, p = 0.001) and mitral valve E deceleration time (225±49 to 247±51ms, p = 0.015) at 1-year follow up. There were no significant changes in left atrium volume index or in the distribution of patients among the different left ventricle geometric patterns and diastolic function subgroups.

Conclusions

In this single centre registry of patients with resistant hypertension, renal denervation was associated with significant reduction in both office and ABPM blood pressure and a significant decrease in left ventricle mass evaluated by transthoracic echocardiogram at 1 year follow-up.     

Central thermoregulatory effects of lactate in the toad Bufo paracnemis

Hypoxia induces a regulated decrease in body temperature (Tb; anapyrexia) in organisms ranging from protozoans to mammals, but very little is known about the mechanisms involved. Several candidates have been suggested to mediate hypoxia-induced anapyrexia, among them lactate, which is a classical companion of hypoxic stress in vertebrates. The present study was designed to assess the central thermoregulatory effects of lactate in Bujo paracnemis. Toads equipped with a temperature probe were tested over a thermal gradient (10–40°C). Lactate injected systemically (4.0 mmol kg⁻¹) caused a significant reduction of Tb from 24.6±2.1 to 17.4±3.9°C. To assess the role of central thermoregulatory mechanisms, a lower dose (0.4 mmol kg⁻¹) of lactate was injected into the fourth cerebral ventricle or systemically. Intracerebroventricular injection of lactate caused a similar decrease in Tb, whereas systemic injection caused no change. The data indicate that lactate may play a role in hypoxia-induced anapyrexia in central rather than peripheral sites.