Resumo em Inglês:

Lipopolysaccharide (LPS)-induced endotoxemia triggers the secretion of proinflammatory cytokines and can cause acute lung injury (ALI). The high mobility group box 1 (HMGB1) protein plays an important role as a late mediator of sepsis and ALI. Galantamine (GAL) is a central acetylcholinesterase inhibitor that inhibits the expression of HMGB1. This study evaluated the effects of GAL by measuring levels of inflammatory mediators and observing histopathological features associated with LPS-induced ALI. Sixty 8-10 week old male Sprague-Dawley rats (200-240 g) were randomized into three groups as follows: control group, LPS group (7.5 mg/kg LPS), and LPS+GAL group (5 mg/kg GAL before LPS administration). Histopathological examination of lung specimens obtained 12 h after LPS administration was performed to analyze changes in wet-to-dry (W/D) weight ratio, myeloperoxidase (MPO) activity, and HMGB1 expression level. Additionally, plasma concentrations of tumor necrosis factor-α, interleukin-6, and HMGB1 were measured using an enzyme-linked immunosorbent assay at 0 (baseline), 3, 6, 9, and 12 h after LPS administration. Mortality in the three groups was recorded at 72 h. LPS-induced ALI was characterized by distortion of pulmonary architecture and elevation of MPO activity, W/D weight ratio, and levels of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-6, and HMGB1. Pretreatment with GAL significantly reduced the LPS-induced lung pathological changes, W/D weight ratio, levels of pro-inflammatory cytokines and MPO activity (ANOVA). Moreover, GAL treatment significantly decreased the mortality rate (ANOVA). In conclusion, we demonstrated that GAL exerted a protective effect on LPS-induced ALI in rats.

Resumo em Inglês:

The aim of this study was to evaluate the effects of sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNTs) and HY-functionalized SWCNTs (HY-SWCNTs) on the behavior of primary osteoblasts, as well as to investigate the deposition of inorganic crystals on titanium surfaces coated with these biocomposites. Primary osteoblasts were obtained from the calvarial bones of male newborn Wistar rats (5 rats for each cell extraction). We assessed cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and by double-staining with propidium iodide and Hoechst. We also assessed the formation of mineralized bone nodules by von Kossa staining, the mRNA expression of bone repair proteins, and the deposition of inorganic crystals on titanium surfaces coated with HY, SWCNTs, or HY-SWCNTs. The results showed that treatment with these biocomposites did not alter the viability of primary osteoblasts. Furthermore, deposition of mineralized bone nodules was significantly increased by cells treated with HY and HY-SWCNTs. This can be partly explained by an increase in the mRNA expression of type I and III collagen, osteocalcin, and bone morphogenetic proteins 2 and 4. Additionally, the titanium surface treated with HY-SWCNTs showed a significant increase in the deposition of inorganic crystals. Thus, our data indicate that HY, SWCNTs, and HY-SWCNTs are potentially useful for the development of new strategies for bone tissue engineering.

Resumo em Inglês:

The aim of this study was to determine the effects of intermittent passive manual stretching on various proteins involved in force transmission in skeletal muscle. Female Wistar weanling rats were randomly assigned to 5 groups: 2 control groups containing 21- and 30-day-old rats that received neither immobilization nor stretching, and 3 test groups that received 1) passive stretching over 3 days, 2) immobilization for 7 days and then passive stretching over 3 days, or 3) immobilization for 7 days. Maximal plantar flexion in the right hind limb was imposed, and the stretching protocol of 10 repetitions of 30 s stretches was applied. The soleus muscles were harvested and processed for HE and picrosirius staining; immunohistochemical analysis of collagen types I, III, IV, desmin, and vimentin; and immunofluorescence labeling of dystrophin and CD68. The numbers of desmin- and vimentin-positive cells were significantly decreased compared with those in the control following immobilization, regardless of whether stretching was applied (P<0.05). In addition, the semi-quantitative analysis showed that collagen type I was increased and type IV was decreased in the immobilized animals, regardless of whether the stretching protocol was applied. In conclusion, the largest changes in response to stretching were observed in muscles that had been previously immobilized, and the stretching protocol applied here did not mitigate the immobilization-induced muscle changes. Muscle disuse adversely affected several proteins involved in the transmission of forces between the intracellular and extracellular compartments. Thus, the 3-day rehabilitation period tested here did not provide sufficient time for the muscles to recover from the disuse maladaptations in animals undergoing postnatal development.

Resumo em Inglês:

Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10). Phenylephrine (Phe) and acetylcholine (Ach) dose-response curves were performed by venous infusion with simultaneous venous and arterial blood pressure monitoring. Plasma nitrite/nitrate (NOx) was measured by chemiluminescence. The CMA group had a blood pH of 7.15±0.03, which was associated with reduced bicarbonate (13.8±0.98 mmol/L) and no change in the partial pressure of arterial carbon dioxide (PaCO2). The AMA group had a pH of 7.20±0.01, which was associated with decreases in bicarbonate (10.8±0.54 mmol/L) and PaCO2 (47.8±2.54 to 23.2±0.74 mmHg) and accompanied by hyperventilation. Phe or ACh infusion did not affect arterial or venous blood pressure in the CMA group. However, the ACh infusion decreased the arterial blood pressure (ΔBP: -28.0±2.35 mm Hg [AMA] to -4.5±2.89 mmHg [control]) in the AMA group. Plasma NOx was normal after CMA but increased after AMA (25.3±0.88 to 31.3±0.54 μM). These results indicate that AMA, but not CMA, potentiated the Ach-induced decrease in blood pressure and led to an increase in plasma NOx, reinforcing the effect of pH imbalance on vascular tone and blood pressure control.

Resumo em Inglês:

β-Citronellol is an alcoholic monoterpene found in essential oils such Cymbopogon citratus (a plant with antihypertensive properties). β-Citronellol can act against pathogenic microorganisms that affect airways and, in virtue of the popular use of β-citronellol-enriched essential oils in aromatherapy, we assessed its pharmacologic effects on the contractility of rat trachea. Contractions of isolated tracheal rings were recorded isometrically through a force transducer connected to a data-acquisition device. β-Citronellol relaxed sustained contractions induced by acetylcholine or high extracellular potassium, but half-maximal inhibitory concentrations (IC50) for K+-elicited stimuli were smaller than those for cholinergic contractions. It also inhibited contractions induced by electrical field stimulation or sodium orthovanadate with pharmacologic potency equivalent to that seen against acetylcholine-induced contractions. When contractions were evoked by selective recruitment of Ca2+ from the extracellular medium, β-citronellol preferentially inhibited contractions that involved voltage-operated (but not receptor-operated) pathways. β-Citronellol (but not verapamil) inhibited contractions induced by restoration of external Ca2+ levels after depleting internal Ca2+ stores with the concomitant presence of thapsigargin and recurrent challenge with acetylcholine. Treatment of tracheal rings with L-NAME, indomethacin or tetraethylammonium did not change the relaxing effects of β-citronellol. Inhibition of transient receptor potential vanilloid subtype 1 (TRPV1) or transient receptor potential ankyrin 1 (TRPA1) receptors with selective antagonists caused no change in the effects of β-citronellol. In conclusion, β-citronellol exerted inhibitory effects on rat tracheal rings, with predominant effects on contractions that recruit Ca2+ inflow towards the cytosol by voltage-gated pathways, whereas it appears less active against contractions elicited by receptor-operated Ca2+ channels.

Resumo em Inglês:

High plasma levels of homocysteine (Hcy) promote the progression of neurodegenerative diseases. However, the mechanism by which Hcy mediates neurotoxicity has not been elucidated. We observed that upon incubation with Hcy, the viability of a neuroblastoma cell line Neuro2a declined in a dose-dependent manner, and apoptosis was induced within 48 h. The median effective concentration (EC50) of Hcy was approximately 5 mM. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) nuclear translocation and acylation has been implicated in the regulation of apoptosis. We found that nuclear translocation and acetylation of GAPDH increased in the presence of 5 mM Hcy and that higher levels of acetyltransferase p300/CBP were detected in Neuro2a cells. These findings implicate the involvement of GAPDH in the mechanism whereby Hcy induces apoptosis in neurons. This study highlights a potentially important pathway in neurodegenerative disorders, and a novel target pathway for neuroprotective therapy.

Resumo em Inglês:

Ropinirole (ROP) is a dopamine agonist that has been used as therapy for Parkinson's disease. In the present study, we aimed to detect whether gene expression was modulated by ROP in SH-SY5Y cells. SH-SY5Y cell lines were treated with 10 µM ROP for 2 h, after which total RNA was extracted for whole genome analysis. Gene expression profiling revealed that 113 genes were differentially expressed after ROP treatment compared with control cells. Further pathway analysis revealed modulation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway, with prominent upregulation of PIK3C2B. Moreover, batches of regulated genes, including PIK3C2B, were found to be located on chromosome 1. These findings were validated by quantitative RT-PCR and Western blot analysis. Our study, therefore, revealed that ROP altered gene expression in SH-SY5Y cells, and future investigation of PIK3C2B and other loci on chromosome 1 may provide long-term implications for identifying novel target genes of Parkinson's disease.

Resumo em Inglês:

Phosphorylated-cyclic adenosine monophosphate response element-binding protein (Phospho-CREB) has an important role in the pathogenesis of myocardial ischemia. We isolated the iridoid glycoside cornin from the fruit of Verbena officinalis L, investigated its effects against myocardial ischemia and reperfusion (I/R) injury in vivo, and elucidated its potential mechanism in vitro. Effects of cornin on cell viability, as well as expression of phospho-CREB and phospho-Akt in hypoxic H9c2 cells in vitro, and myocardial I/R injury in vivo, were investigated. Cornin attenuated hypoxia-induced cytotoxicity significantly in H9c2 cells in a concentration-dependent manner. Treatment of H9c2 cells with cornin (10 µM) blocked the reduction of expression of phospho-CREB and phospho-Akt in a hypoxic condition. Treatment of rats with cornin (30 mg/kg, iv) protected them from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics, and reduction of severity of myocardial damage. Cornin treatment also attenuated the reduction of expression of phospho-CREB and phospho-Akt in ischemic myocardial tissue. These data suggest that cornin exerts protective effects due to an increase in expression of phospho-CREB and phospho-Akt.

Resumo em Inglês:

This study evaluated the effect of muscle satellite cells (MSCs) overexpressing myogenin (MyoG) on denervated muscle atrophy. Rat MSCs were isolated and transfected with the MyoG-EGFP plasmid vector GV143. MyoG-transfected MSCs (MTMs) were transplanted into rat gastrocnemius muscles at 1 week after surgical denervation. Controls included injections of untransfected MSCs or the vehicle only. Muscles were harvested and analyzed at 2, 4, and 24 weeks post-transplantation. Immunofluorescence confirmed MyoG overexpression in MTMs. The muscle wet weight ratio was significantly reduced at 2 weeks after MTM injection (67.17±6.79) compared with muscles injected with MSCs (58.83±5.31) or the vehicle (53.00±7.67; t=2.37, P=0.04 and t=3.39, P=0.007, respectively). The muscle fiber cross-sectional area was also larger at 2 weeks after MTM injection (2.63×103±0.39×103) compared with MSC injection (1.99×103±0.58×103) or the vehicle only (1.57×103±0.47×103; t=2.24, P=0.049 and t=4.22, P=0.002, respectively). At 4 and 24 weeks post-injection, the muscle mass and fiber cross-sectional area were similar across all three experimental groups. Immunohistochemistry showed that the MTM group had larger MyoG-positive fibers. The MTM group (3.18±1.13) also had higher expression of MyoG mRNA than other groups (1.41±0.65 and 1.03±0.19) at 2 weeks after injection (t=2.72, P=0.04). Transplanted MTMs delayed short-term atrophy of denervated muscles. This approach can be optimized as a novel stand-alone therapy or as a bridge to surgical re-innervation of damaged muscles.

Resumo em Inglês:

Various methods are available for preservation of vascular grafts for pulmonary artery (PA) replacement. Lyophilization and cryopreservation reduce antigenicity and prevent thrombosis and calcification in vascular grafts, so both methods can be used to obtain vascular bioprostheses. We evaluated the hemodynamic, gasometric, imaging, and macroscopic and microscopic findings produced by PA reconstruction with lyophilized (LyoPA) grafts and cryopreserved (CryoPA) grafts in dogs. Eighteen healthy crossbred adult dogs of both sexes weighing between 18 and 20 kg were used and divided into three groups of six: group I, PA section and reanastomosis; group II, PA resection and reconstruction with LyoPA allograft; group III, PA resection and reconstruction with CryoPA allograft. Dogs were evaluated 4 weeks after surgery, and the status of the graft and vascular anastomosis were examined macroscopically and microscopically. No clinical, radiologic, or blood-gas abnormalities were observed during the study. The mean pulmonary artery pressure (MPAP) in group III increased significantly at the end of the study compared with baseline (P=0.02) and final [P=0.007, two-way repeat-measures analysis of variance (RM ANOVA)] values. Pulmonary vascular resistance of groups II and III increased immediately after reperfusion and also at the end of the study compared to baseline. The increase shown by group III vs group I was significant only if compared with after surgery and study end (P=0.016 and P=0.005, respectively, two-way RM ANOVA). Microscopically, permeability was reduced by ≤75% in group III. In conclusion, substitution of PAs with LyoPA grafts is technically feasible and clinically promising.

Resumo em Inglês:

We aimed to evaluate the effectiveness and safety of bismuth-containing quadruple therapy plus postural change after dosing for Helicobacter pylori eradication in gastrectomized patients. We compared 76 gastric stump patients with H. pylori infection (GS group) with 50 non-gastrectomized H. pylori-positive patients who met the treatment indication (controls). The GS group was divided into GS group 1 and GS group 2. All groups were administered bismuth potassium citrate (220 mg), esomeprazole (20 mg), amoxicillin (1.0 g), and furazolidone (100 mg) twice daily for 14 days. GS group 1 maintained a left lateral horizontal position for 30 min after dosing. H. pylori was detected using rapid urease testing and histologic examination of gastric mucosa before and 3 months after therapy. Mucosal histologic manifestations were evaluated using visual analog scales of the updated Sydney System. GS group 1 had a higher prevalence of eradication than the GS group 2 (intention-to-treat [ITT]: P=0.025; per-protocol [PP]: P=0.030), and the control group had a similar prevalence. GS group 2 had a lower prevalence of eradication than controls (ITT: P=0.006; PP: P=0.626). Scores for chronic inflammation and activity declined significantly (P<0.001) 3 months after treatment, whereas those for atrophy and intestinal metaplasia showed no significant change. Prevalence of adverse reactions was similar among groups during therapy (P=0.939). A bismuth-containing quadruple therapy regimen plus postural change after dosing appears to be a relatively safe, effective, economical, and practical method for H. pylori eradication in gastrectomized patients.

Resumo em Inglês:

The oxygen uptake efficiency slope (OUES) is a submaximal index incorporating cardiovascular, peripheral, and pulmonary factors that determine the ventilatory response to exercise. The purpose of this study was to evaluate the effects of continuous exercise training and interval exercise training on the OUES in patients with coronary artery disease. Thirty-five patients (59.3±1.8 years old; 28 men, 7 women) with coronary artery disease were randomly divided into two groups: continuous exercise training (n=18) and interval exercise training (n=17). All patients performed graded exercise tests with respiratory gas analysis before and 3 months after the exercise-training program to determine ventilatory anaerobic threshold (VAT), respiratory compensation point, and peak oxygen consumption (peak VO2). The OUES was assessed based on data from the second minute of exercise until exhaustion by calculating the slope of the linear relation between oxygen uptake and the logarithm of total ventilation. After the interventions, both groups showed increased aerobic fitness (P<0.05). In addition, both the continuous exercise and interval exercise training groups demonstrated an increase in OUES (P<0.05). Significant associations were observed in both groups: 1) continuous exercise training (OUES and peak VO2 r=0.57; OUES and VO2 VAT r=0.57); 2) interval exercise training (OUES and peak VO2 r=0.80; OUES and VO2 VAT r=0.67). Continuous and interval exercise training resulted in a similar increase in OUES among patients with coronary artery disease. These findings suggest that improvements in OUES among CAD patients after aerobic exercise training may be dependent on peripheral and central mechanisms.