Effects of high temperature and LPS injections on the hemocytes of the crab Neohelice granulata.

Temperature fluctuations, particularly elevated temperatures, can significantly affect immune responses. These fluctuations can influence the immune system and alter its response to infection signals, such as lipopolysaccharide (LPS). Therefore, this study was designed to investigate how high temperatures and LPS injections collectively influence the immune system of the crab Neohelice granulata. Two groups were exposed to 20 °C (control) or 33 °C for four days. Subsequently, half were injected with 10 µL of physiological crustacean (PS), while the rest received 10 µL of LPS [0.1 mg.kg-1]. After 30 min, the hemolymph samples were collected. Hemocytes were then isolated and assessed for various parameters using flow cytometry, including cell integrity, DNA fragmentation, total hemocyte count (THC), differential hemocyte count (DHC), reactive oxygen species (ROS) level, lipid peroxidation (LPO), and phagocytosis. Results showed lower cell viability at 20 °C, with more DNA damage in the same LPS-injected animals. There was no significant difference in THC, but DHC indicated a decrease in hyaline cells (HC) at 20 °C following LPS administration. In granular cells (GC), an increase was observed after both PS and LPS were injected at the same temperature. In semi-granular cells (SGC), there was a decrease at 20 °C with the injection of LPS, while at a temperature of 33 °C, the SGC there was a decrease only in SGC injected with LPS. Crabs injected with PS and LPS at 20 °C exhibited higher levels of ROS in GC and SGC, while at 33 °C, the increase was observed only in GC and SGC cells injected with LPS. A significant increase in LPO was observed only in SGC cells injected with PS and LPS at 20 °C and 33 °C. Phagocytosis decreased in animals at 20 °C with both injections and exposed to 33 °C only in those injected with LPS. These results suggest that elevated temperatures induce changes in immune system parameters and attenuate the immune responses triggered by LPS.

Effect of CPAP vs. mandibular advancement device for excessive daytime sleepiness, fatigue, mood, sustained attention, and quality of life in patients with mild OSA.

OBJECTIVE: This study's objective was to compare the best long-term treatment, mandibular advancement device (MAD) or continuous positive airway pressure (CPAP), for patients with mild obstructive sleep apnea (OSA) in improving excessive daytime sleepiness, fatigue, mood, sustained attention, and quality of life. METHODS: This study was a single-blind, parallel, randomized clinical trial with controls. The sample was composed of individuals between 18 and 65 years of age with a body mass index of < 35 kg/m2 and apnea/hypopnea index above five and less than 15. Participants were submitted to physical examination, polysomnography, and the following questionnaires: Pittsburgh Sleep Quality Index, Berlin Questionnaire, Epworth Sleepiness Scale, Stanford Sleepiness Scale, Karolinska Sleepiness Scale, Modified Fatigue Impact Scale, Functional Outcomes of Sleep Questionnaire, Beck Anxiety Inventory, and Beck Depression Inventory. They were also presented with the following tests: maintenance of wakefulness test and psychomotor vigilance task. RESULTS: Of 79 patients, 25 were in the MAD group, 31 in the CPAP group, and 23 in the control group. Polysomnographic parameters were best normalized with CPAP compared with MAD. Fatigue was improved in the MAD and CPAP groups, with no difference between these treatments. Quality of life was also improved with both treatments, but CPAP was superior to MAD. Daytime sleepiness, mood, and sustained attention showed no difference with the interventions. Greater adherence was obtained with MAD patients than with CPAP measured by hours of use. CONCLUSIONS: Treatment with CPAP was better at normalizing polysomnographic parameters and improving quality of life in patients with mild OSA. Both treatments improved fatigue with no difference between the two treatments. Neither treatment improved daytime sleepiness, mood or sustained attention. CLINICAL TRIALS DATABASE: NTC01461486.

Can hypoosmotic shock and calcium influx lead to translocation of aquaporin-1 in shrimp muscle cells?

The physiological variations during the crustacean molting cycle have intrigued researchers for many years. Maintaining osmotic homeostasis in the face of hemolymph dilution and dealing with dynamic intracellular and extracellular calcium fluctuations are challenges these animals continuously confront. It has recently been shown that water channels present in the cell membrane (aquaporins) are essential for water uptake during premolt and postmolt. This study aims to investigate whether hypoosmotic shock and intracellular and extracellular calcium variations can lead to translocation of Aquaporin 1 (AQP-1) from the intracellular region to the plasma membrane during premolt and postmolt, thus allowing increased water flow in these stages. For this, we investigate in vitro the rapid change of AQP-1 positions in the abdominal muscle cells in the freshwater shrimp, Palaemon argentinus. Using cell volume analysis and immunohistochemistry, we show that hypoosmotic conditions and an elevation of the intracellular and extracellular calcium concentrations are concurrent with the translocation of AQP-1 to the plasma membrane. These results indicate that calcium flux and hypoosmotic shock may be regulators of AQP 1 in the translocation process.

Oxygen sensing in crustaceans: functions and mechanisms.

Animals that live in changing environments need to adjust their metabolism to maintain body functions, and sensing these changing conditions is essential for mediating the short- and long-term physiological and behavioral responses that make these adjustments. Previous research on nematodes and insects facing changing oxygen levels has shown that these animals rapidly respond using atypical soluble guanylyl cyclases (sGCs) as oxygen sensors connected to downstream cGMP pathways, and they respond more slowly using hypoxia-inducible transcription factors (HIFs) that are further modulated by oxygen-sensing prolyl hydroxylases (PHs). Crustaceans are known to respond in different ways to hypoxia, but the mechanisms responsible for sensing oxygen levels are more poorly understood than in nematodes and insects. Our paper reviews the functions of and mechanisms underlying oxygen sensing in crustaceans. Furthermore, using the oxygen sensing abilities of nematodes and insects as guides in analyzing available crustacean transcriptomes, we identified orthologues of atypical sGCs, HIFs, and PHs in crustaceans, including in their chemosensory organs and neurons. These molecules include atypical sGCs activated by hypoxia (Gyc-88E/GCY-31 and Gyc-89D/GCY-33) but not those activated by hyperoxia (GCY-35, GCY-36), as well as orthologues of HIF-α, HIF-ß, and PH. We offer possible directions for future research on oxygen sensing by crustaceans.

Synthesis of pyrazoline fatty chain derivatives and its effects on melanoma cells.

Skin cancer is the most common type of cancer in Brazil, representing 30% of all cases. Among these, melanoma represents only 3% of malignant neoplasms; however, it is the most serious and has a high capacity for metastasis. For this reason, it is extremely important to identify more efficient compounds and treatments that stop or decrease the proliferation of melanoma, even in its more advanced stages. This work reports the synthesis and biological evaluation of two homologous series of pyrazoline fatty chain derivatives as potent antitumoral agents in the melanoma B16F10 cell line. Cells were treated with pyrazoline fatty chain compounds (3, 30, 300, and 3000 µM) for 0, 24, 48, and 72 h. Decreased cell viability was observed when using most compounds at different concentrations and times. The structure-activity relationship (SAR) between antitumoral activity and the number of carbons and lipophilicity, as well as the oxygen-sulfur bioisosteric exchange, was evaluated. Among the tested derivatives, the lipophilic compounds 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-carboxamide (2d) and 5-hydroxy-5-(trifluoromethyl)-3-undecyl-4,5-dihydro-1H-pyrazole-1-thiocarboxamide (3d) showed the best results in the B16F10 cell line, as they produced the best cell viability decrease effects. The presence of fatty unbranched undecyl chain in the molecular structure appears to be important for its antimelanoma properties.

Emersion behavior of the semi-terrestrial crab Neohelice granulata during hypoxic conditions: Lactate as a trigger.

Climate changes affecting aquatic environments are increasing, and the resultant environmental challenges require animals to adopt alternative compensatory behavioral and physiological strategies. In particular, low levels of dissolved O2 are a regular problem for estuarine animals, leading to activation of a series of behavioral and physiological responses. This study on the semi-terrestrial crab Neohelice granulata examined patterns of emersion behavior under different levels of dissolved O2 availability and the role of lactate in this behavior. Emersion behavior was recorded for 4.5 h for crabs in water at four different levels of dissolved O2 (6, 3, 2, and 1 mg O2/L) and with free access to air. Oxygen consumption and hemolymphatic lactate levels were measured using the same experimental design. Emersion behavior was also recorded for 70 min in normoxic water after lactate or saline injections. Crabs increased their emersion behavior only in severe hypoxia (1 mg O2/L), and O2 consumption decreased under more severe hypoxic conditions. Despite the increase in emersion behavior, which leads to higher O2 availability, an increase in hemolymphatic lactate levels indicates that the animals still need to resort to anaerobic pathways to fulfill their metabolic demand. Furthermore, animals injected with lactate showed higher emersion behaviors than animals injected with a saline solution even in normoxia. These results suggest that the increase in hemolymphatic lactate can act directly or indirectly as a trigger for the increase in emersion behavior in the semi-terrestrial crab N. granulata.

High temperature acclimation alters the emersion behavior in the crab Neohelice granulata.

An increase in environmental temperature can deleteriously affect organisms. This study investigated whether the semiterrestrial estuarine crab Neohelice granulata uses emersion behavior as a resource to avoid thermal stress and survive higher aquatic temperatures. We also examined whether this behavior is modulated by exposure to high temperature; whether, during the period of emersion, the animal loses heat from the carapace to the medium; and whether this behavior is altered by the temperature at which the animal has been acclimated. The lethal temperature for 50% of the population (LT50) was determined through 96-h mortality curves in animals acclimated at 20 °C and 30 °C. The behavioral profile of N. granulata during thermal stress was based on monitoring crab movement in aerial, intermediary, and aquatic zones. Acclimation at a higher temperature and the possibility of emersion increased the thermotolerance of the crabs and the synergistic effect of acclimation temperature. The possibility of leaving the hot water further increased the resistance of these animals to thermal stress. We observed that when the crab was subjected to thermal stress conditions, it spent more time in the aerial environment, unlike under control conditions. Under the experimental conditions, it made small incursions into the aquatic environment and stayed in the aerial environment for a longer time in order to cool its body temperature. The animals acclimated at 20 °C and placed into water at 35 °C remained in the aerial zone. The animals acclimated and maintained at 30 °C (control) that were placed in water at 35 °C with the possibility of emerging into hot air transited more frequently between the aquatic and aerial zones than did the animals that were put in water at 35 °C with the possibility of emerging into a cooler air environment. We conclude that emergence behavior allows N. granulata to survive high temperatures and that this behavior is influenced by acclimation temperature.

Synthesis and antioxidant activity of new lipophilic dihydropyridines.

Dihydropyridines (DHPs) obtained from Hantzsch multicomponent reactions are an important pharmaceutical class of compounds marketed as antihypertensive (e.g., nifedipine, nitrendipine, and amlodipine) drugs. This study synthesized new symmetrical and unsymmetrical long-chain fatty DHPs using multicomponent reactions under metal-free conditions with sulfamic acid as a catalyst. The DHPs were tested for antioxidant activity using three different methods. The insertion of a long chain into the DHP core contributed to antioxidant potential, and compounds derived from nitro aldehydes have better antioxidant potential than the antihypertensive drug nifedipine. In addition, fatty analogs to nifedipine derived from palmitic and oleic chains showed similar antioxidant activity to the common standards butylated hydroxytoluene and vitamin E. These results showed that our new synthesized products may find novel applications as antioxidant additives or for tools for use in drug discovery.

Damage caused during hypoxia and reoxygenation in the locomotor muscle of the crab Neohelice granulata (Decapoda: Varunidae).

The aim of this work was to determine whether different durations of severe hypoxia (0.5 mg O2 L(-1)) followed by reoxygenation cause damage to the locomotor muscle of the crab Neohelice granulata. We evaluated reactive oxygen species (ROS), lipid peroxidation (LPO), mitochondrial membrane potential, and aerobic fiber area of the locomotor muscle after different periods of hypoxia (1, 4, or 10h) followed by 30 or 120 min of reoxygenation. Additionally, changes in cell volume, mitochondrial dysfunction, and infiltration of hemocytes were evaluated after hypoxia and a subsequent 2, 24, or 48 h of reoxygenation. After hypoxia, neither ROS nor LPO increased. However, mitochondrial membrane potential and aerobic fiber area decreased in a time-dependent manner. After reoxygenation, the ROS and LPO levels increased and mitochondrial membrane potential decreased, but these quickly recovered in crabs exposed to 4h of hypoxia. On the other hand, alterations of mitochondria resulted in morphological changes in aerobic fibers, which required more time to recover during reoxygenation after 10h of hypoxia. The locomotor muscles of the crab N. granulata suffer damage after hypoxia and reoxygenation. The intensity of this damage is dependent on the duration of hypoxia. In all experimental situations analyzed, the locomotor muscle of this crab was capable of recovery.

Melatonin as a signaling molecule for metabolism regulation in response to hypoxia in the crab Neohelice granulata.

Melatonin has been identified in a variety of crustacean species, but its function is not as well understood as in vertebrates. The present study investigates whether melatonin has an effect on crustacean hyperglycemic hormone (CHH) gene expression, oxygen consumption (VO2) and circulating glucose and lactate levels, in response to different dissolved-oxygen concentrations, in the crab Neohelice granulata, as well as whether these possible effects are eyestalk- or receptor-dependent. Melatonin decreased CHH expression in crabs exposed for 45 min to 6 (2, 200 or 20,000 pmol·crab-1) or 2 mgO2·L-1 (200 pmol·crab-1). Since luzindole (200 nmol·crab-1) did not significantly (p > 0.05) alter the melatonin effect, its action does not seem to be mediated by vertebrate-typical MT1 and MT2 receptors. Melatonin (200 pmol·crab-1) increased the levels of glucose and lactate in crabs exposed to 6 mgO2·L-1, and luzindole (200 nmol·crab-1) decreased this effect, indicating that melatonin receptors are involved in hyperglycemia and lactemia. Melatonin showed no effect on VO2. Interestingly, in vitro incubation of eyestalk ganglia for 45 min at 0.7 mgO2·L-1 significantly (p < 0.05) increased melatonin production in this organ. In addition, injections of melatonin significantly increased the levels of circulating melatonin in crabs exposed for 45 min to 6 (200 or 20,000 pmol·crab-1), 2 (200 and 20,000 pmol·crab-1) and 0.7 (200 or 20,000 pmol·crab-1) mgO2·L-1. Therefore, melatonin seems to have an effect on the metabolism of N. granulata. This molecule inhibited the gene expression of CHH and caused an eyestalk- and receptor-dependent hyperglycemia, which suggests that melatonin may have a signaling role in metabolic regulation in this crab.

Responses to ROS inducer agents in zebrafish cell line: differences between copper and UV-B radiation.

Fish are commonly exposed to environmental pollutants, which in turns could induce an oxidative stress. So, it is important to understand the effects and the responses elicited by these toxicants in fish species, being fish cell lines important tools for this purpose. Thus, the aim of the present study was to compare the effects of copper and UV-B radiation exposure on zebrafish hepatocytes (ZFL lineage) in terms of reactive oxygen species (ROS) levels, sulfhydril groups content and mRNA levels of important genes related to cellular response to toxic agents. Exposure of ZFL cells to UV-B radiation (23.3 mJ/cm(2)) significantly increased levels of intracellular ROS and mRNA of both superoxide dismutase isoforms (sod1 and sod2), three glutathione S-transferase isoforms (gstα, gstµ and gstπ) and a heat shock protein (hsp70). However, no changes in nonprotein sulfhydryl groups (NP-SH) content, as well as in the mRNA levels of genes related to glutathione (GSH) synthesis and recycling, were observed. Contrary to this, copper exposure (20 mg/L) diminished NP-SH content and increased the levels of mRNA of genes related to GSH synthesis (gclc and gs). Moreover, copper exposure increases the mRNA levels of some genes related to antioxidant defenses (gpx and gstπ), biotransformation reactions (cyp1a1) and protein repair (hsp70). In conclusion, these results demonstrated that both toxicants could increase ROS levels in ZFL cell line, but the responses are different, which could be related to activation of different signaling pathways.

Exercise tolerance with helium-hyperoxia versus hyperoxia in hypoxaemic patients with COPD.

The purpose of this study was to investigate whether helium-hyperoxia (HeHOx) would allow greater tolerance to maximal and submaximal exercise compared to hyperoxia (HOx) on isolation in hypoxaemic chronic obstructive pulmonary disease (COPD) patients under long-term oxygen therapy. In a double-blind study, 24 males in the Global Initiative for Chronic Obstructive Lung Disease functional class IV (forced expiratory volume in 1 s 35.2±10.1% predicted and arterial oxygen tension 56.2±7.5 mmHg) were submitted to incremental and constant load cycling at 70-80% peak work rate while breathing HOx (60% nitrogen and 40% oxygen) or HeHOx (60% helium and 40% oxygen). HeHOx improved resting airflow obstruction and lung hyperinflation in all but two patients (p<0.05). Peak work rate and time to exercise intolerance were higher with HeHOx than HOx in 17 (70.8%) out of 24 patients and 14 (66.6%) out of 21 patients, respectively (p<0.05). End-expiratory lung volumes were lower with HeHOx, despite a higher ventilatory response (p<0.05). HeHOx speeded on-exercise oxygen uptake kinetics by ∼30%, especially in more disabled and hyperinflated patients. Fat-free mass was the only independent predictor of higher peak work rate with HeHOx (r(2) = 0.66, p<0.001); in contrast, none of the resting characteristics or exercise responses were related to improvements in time to exercise intolerance (p>0.05). Helium is a valuable ergogenic aid when added to HOx for most long-term oxygen therapy-dependent patients with advanced COPD.

Exercise intolerance in post-coronavirus disease 2019 survivors after hospitalisation.

Rationale: Post-coronavirus disease 2019 (COVID-19) survivors frequently have dyspnoea that can lead to exercise intolerance and lower quality of life. Despite recent advances, the pathophysiological mechanisms of exercise intolerance in the post-COVID-19 patients remain incompletely characterised. The objectives of the present study were to clarify the mechanisms of exercise intolerance in post-COVID-19 survivors after hospitalisation. Methods: This prospective study evaluated consecutive patients previously hospitalised due to moderate-to-severe/critical COVID-19. Within mean±sd 90±10 days of onset of acute COVID-19 symptoms, patients underwent a comprehensive cardiopulmonary assessment, including cardiopulmonary exercise testing with earlobe arterialised capillary blood gas analysis. Measurements and main results: 87 patients were evaluated; mean±sd peak oxygen consumption was 19.5±5.0 mL·kg-1·min-1, and the tertiles were ≤17.0, 17.1-22.2 and ≥22.3 mL·kg-1·min-1. Hospitalisation severity was similar among the three groups; however, at the follow-up visit, patients with peak oxygen consumption ≤17.0 mL·kg-1·min-1 reported a greater sensation of dyspnoea, along with indices of impaired pulmonary function, and abnormal ventilatory, gas-exchange and metabolic responses during exercise compared to patients with peak oxygen consumption >17 mL·kg-1·min-1. By multivariate logistic regression analysis (receiver operating characteristic curve analysis) adjusted for age, sex and prior pulmonary embolism, a peak dead space fraction of tidal volume ≥29 and a resting forced vital capacity ≤80% predicted were independent predictors of reduced peak oxygen consumption. Conclusions: Exercise intolerance in the post-COVID-19 survivors was related to a high dead space fraction of tidal volume at peak exercise and a decreased resting forced vital capacity, suggesting that both pulmonary microcirculation injury and ventilatory impairment could influence aerobic capacity in this patient population.

Heart rate recovery in pulmonary arterial hypertension: relationship with exercise capacity and prognosis.

BACKGROUND: Delayed postexercise heart rate recovery (HRR) has been associated with disability and poor prognosis in chronic cardiopulmonary diseases. The usefulness of HRR to predict exercise impairment and mortality in patients with pulmonary arterial hypertension (PAH), however, remains largely unexplored. METHODS: Seventy-two patients with PAH of varied etiology (New York Heart Association classes I-IV) and 21 age- and gender-matched controls underwent a maximal incremental cardiopulmonary exercise test (CPET), with heart rate being recorded up to the fifth minute of recovery. RESULTS: Heart rate recovery was consistently lower in the patients compared with the controls (P < .05). The best cutoff for HRR in 1 minute (HRR(1 min)) to discriminate the patients from the controls was 18 beats. Compared with patients with HRR(1 min) ≤ 18 (n = 40), those with HRR(1 min) >18 (n = 32) had better New York Heart Association scores, resting hemodynamics and 6-minute walking distance. In fact, HRR(1 min) >18 was associated with a range of maximal and submaximal CPET variables indicative of less severe exercise impairment (P < .05). The single independent predictor of HRR(1 min) ≤ 18 was the 6-minute walking distance (odds ratio [95% CI] 0.99 [0.98-1.00], P < .05). On a multiple regression analysis that considered only CPET-independent variables, HRR(1 min) ≤ 18 was the single predictor of mortality (hazard ratio [95% CI] 1.19 [1.03-1.37], P < .05). CONCLUSIONS: Preserved HRR(1 min) (>18 beats) is associated with less impaired responses to incremental exercise in patients with PAH. Conversely, a delayed HRR(1 min) response has negative prognostic implications, a finding likely to be clinically useful when more sophisticated (and costlier) analyses provided by a full CPET are not available.

Skeletal muscle reoxygenation after high-intensity exercise in mitochondrial myopathy.

This study addressed whether O(2) delivery during recovery from high-intensity, supra-gas exchange threshold exercise would be matched to O(2) utilization at the microvascular level in patients with mitochondrial myopathy (MM). Off-exercise kinetics of (1) pulmonary O(2) uptake VO(2P) (2) an index of fractional O(2) extraction by near-infrared spectroscopy (Δ[deoxy-Hb + Mb]) in the vastus lateralis and (3) cardiac output (Q'(T)) by impedance cardiography were assessed in 12 patients with biopsy-proven MM (chronic progressive external ophthalmoplegia) and 12 age- and gender-matched controls. Kinetics of VO(2P) were significantly slower in patients than controls (τ = 53.8 ± 16.5 vs. 38.8 ± 7.6 s, respectively; p < 0.05). Q'(T), however, declined at similar rates (τ = 64.7 ± 18.8 vs. 73.0 ± 21.6 s; p > 0.05) being typically slower than [Formula: see text] in both groups. Importantly, Δ[deoxy-Hb + Mb] dynamics (MRT) were equal to, or faster than, τVO(2P) in patients and controls, respectively. In fact, there were no between-group differences in τVO(2P)MRTΔ[deoxy-Hb + Mb] (1.1 ± 0.4 vs. 1.0 ± 0.2, p > 0.05) thereby indicating similar rates of microvascular O(2) delivery. These data indicate that the slower rate of recovery of muscle metabolism after high-intensity exercise is not related to impaired microvascular O(2) delivery in patients with MM. This phenomenon, therefore, seems to reflect the intra-myocyte abnormalities that characterize this patient population.

Chronic immune challenge is detrimental to female survival, feeding behavior, and reproduction in the field cricket Gryllus assimilis (Fabricius, 1775).

Physiological trade-offs among expensive fitness-related traits, such as reproduction and immunity, are common in life histories of animals. An immune challenge can have different effects on female reproduction mediated by resource allocation and acquisition. In this study, employing a widely used method to challenge the insect immune system (nylon implant), we assessed the effects of mounting a chronic immune response simulating three successive immune assaults on survival and reproduction of mated females of Gryllus assimilis. We also verified feeding behavior following an implantation, which can be important in explaining trade-off dynamics in terms of energy acquisition. For this, three experimental groups were designed (Control, Sham, and Implant) with oviposition rates, egg morphometry, and nymph vigour observed over 3 weeks, at which ovarian mass and unlaid eggs were quantified from remaining individuals. The results showed that chronic implants were detrimental to female survival and reproduction throughout the experiments; Surgical Sham had no effect on survival compared to the control, but did on reproductive aspects such as oviposition rates and hatchling vigour. These negative effects on reproduction in Sham disappeared in the last experimental week, but still strong in the implanted females. Such immune challenge affected the feeding behavior of implanted females by reducing food consumption compared to control after infection, which is probably explained by illness-induced anorexia that takes place to maximize the immune system performance as a part of sickness behavior, exacerbating the adverse effects observed on reproduction (i.e., fewer and smaller eggs, and low vigour of nymphs) and survival.

Risk prediction for Obstructive Sleep Apnea prognostic in Obese patients referred for bariatric surgery.

OBJECTIVES: (i) To assess the anthropometric measurements, along with the clinical characteristics and quality of life profiles of the studied patients; (ii) To determine the occurrence and severity of Obstructive Sleep Apnea (OSA), using polysomnography; and (iii) To identify the best anthropometric and clinical indicators to predict OSA in obese patients who are candidates for bariatric surgery. METHODS: a prospective observational study conducted in a private clinic, using consecutive sampling of patients eligible for bariatric surgery with a BMI ≥ 40, or with a BMI of ≥ 35 kg/m² accompanied by comorbidities associated with obesity. RESULTS: Sixty patients were initially selected, of whom 46 agreed to take part in the preoperative evaluation. OSA was observed in 76% of patients, 59% of whom had moderate-to-severe OSA, with a predominance of men in these groups. Among the variables suggesting statistical difference between groups, waist-to-hip ratio (WHR) was the only clinical factor associated with scores the apnea hypopnea index (AHI) ≥ 15, with a cut-off value of 0.95. The results showed that patients scoring above 0.95 are three times more likely to have moderate-to-severe apnea. CONCLUSION: The best risk factor for the prognostic of moderate-to-severe OSA was presenting a WHR score with a cut-off value of 0.95 or above.

Effects of seasonality and moult cycle on the proliferation of nerve cells and on the labelling of ecdysone receptors in an estuarine crab.

Decapod crustaceans show proliferation of the nerve cells in the olfactory lobe throughout their lives. However, the regulation of this process is still poorly understood, since it may vary with endogenous and exogenous factors. The objective of the present investigation was to quantify the proliferation of nerve cells and number of nerve cells with ecdysone receptors in the clusters of the central olfactory system in Neohelice granulata, according to moult stages and in different seasons (summer and winter). Three injections of bromodeoxyuridine (BrdU) were administered to the crabs. Brains were sectioned by microtome and fixed on slides for immunohistochemistry with anti-BrdU and anti-EcR antibodies. The proliferation of nerve cells was higher in winter than in summer, probably because in winter the crabs do not breed and the premoult and postmoult periods are longer. Crabs in postmoult exhibited more BrdU-labelled cells than crabs in premoult or intermoult in winter, because of a greater number of mitoses related to an increase in body size and addition of olfactory receptor neurons. The number of EcR-labelled cells was higher in premoult than in postmoult or intermoult in winter. The proliferation of nerve cells is regulated seasonally and according to moult stages.

Reproductive Status Modulates Mortality Rate, Lifespan and Egg Production, but Do Not the Physiological Aging in the Field Cricket Gryllus assimilis (Fabricius, 1775) (Orthoptera: Gryllidae).

The effects of reproduction are variable among insects, as well as the time of mate. In animals, a trade-off is usually observed between reproduction and self-maintenance, mostly in females because of egg producing costs. In the present investigation, manifestations of aging and senescence at population and cellular levels were studied associated with the mating opportunities. The main goal of this study was to evaluate the effect of mating on lifespan and also on the physiological aging in adult Jamaican field cricket females, Gryllus assimilis (Fabricius, 1775). Three experimental groups were set: virgin, normal-mated (14 days old), and late-mated (30 days old) insects. Lifespan, age-specific mortality rate, number of eggs laid, and in situ amount of the age-pigment neurolipofuscin were quantified. Results showed a trade-off between reproductive females and lifespan, with the strongest effects found in late-mated. Age-specific mortality showed a faster increase for late-mated females from 35 to 50 days old, followed by normal-mated females (35 to 60 days old). Virgins had the lowest age-specific mortality of all, increasing just from 65 to 73 days old. Normal-mated had the highest number of eggs laid, followed by late-mated and virgins, respectively. Neurolipofuscin accumulation rate was similar among groups, which was reflected in similar physiological rate of aging. Results indicate that reproductive status did affect the life-history of these field cricket females.

Proportional Assist Ventilation Improves Leg Muscle Reoxygenation After Exercise in Heart Failure With Reduced Ejection Fraction.

BACKGROUND: Respiratory muscle unloading through proportional assist ventilation (PAV) may enhance leg oxygen delivery, thereby speeding off-exercise oxygen uptake ( V . ⁢ O 2 ) kinetics in patients with heart failure with reduced left ventricular ejection fraction (HFrEF). METHODS: Ten male patients (HFrEF = 26 ± 9%, age 50 ± 13 years, and body mass index 25 ± 3 kg m2) underwent two constant work rate tests at 80% peak of maximal cardiopulmonary exercise test to tolerance under PAV and sham ventilation. Post-exercise kinetics of V . ⁢ O 2 , vastus lateralis deoxyhemoglobin ([deoxy-Hb + Mb]) by near-infrared spectroscopy, and cardiac output (Q T ) by impedance cardiography were assessed. RESULTS: PAV prolonged exercise tolerance compared with sham (587 ± 390 s vs. 444 ± 296 s, respectively; p = 0.01). PAV significantly accelerated V . ⁢ O 2 recovery (τ = 56 ± 22 s vs. 77 ± 42 s; p < 0.05), being associated with a faster decline in Δ[deoxy-Hb + Mb] and Q T compared with sham (τ = 31 ± 19 s vs. 42 ± 22 s and 39 ± 22 s vs. 78 ± 46 s, p < 0.05). Faster off-exercise decrease in Q T with PAV was related to longer exercise duration (r = -0.76; p < 0.05). CONCLUSION: PAV accelerates the recovery of central hemodynamics and muscle oxygenation in HFrEF. These beneficial effects might prove useful to improve the tolerance to repeated exercise during cardiac rehabilitation.