Tracheal instillation of urban PM2.5 suspension promotes acute cardiac polarization changes in rats

The mechanisms by which PM2.5 increases cardiovascular mortality are not fully identified. Autonomic alterations are the current main hypotheses. Our objective was to determine if PM2.5 induces acute cardiac polarization alterations in healthy Wistar rats. PM2.5 samples were collected on polycarbonate filters. Solutions containing 10, 20, and 50 µg PM2.5 were administered by tracheal instillation. P wave duration decreased significantly at 20 µg (0.99 ± 0.06, 0.95 ± 0.06, and 0.96 ± 0.07; P < 0.001), and 50 µg (0.98 ± 0.06, 0.98 ± 0.07, and 0.96 ± 0.08; 60, 90 and 120 min, respectively) compared to blank filter solution (P < 0.001). PR interval duration decreased significantly at 20 µg (0.99 ± 0.06, 0.98 ± 0.07, and 0.97 ± 0.08) and 50 µg (0.99 ± 0.05, 0.97 ± 0.0, and 0.95 ± 0.05; 60, 90, and 120 min, respectively) compared to blank filter and 10 µg (P < 0.001). QRS interval duration decreased at 20 and 50 µg in relation to blank filter solution and 10 µg (P < 0.001). QT interval duration decreased significantly (P < 0.001) with time in animals receiving 20 µg (0.94 ± 0.12, 0.88 ± 0.14, and 0.88 ± 0.11) and 50 µg (1.00 ± 0.13; 0.97 ± 0.11 and 0.98 ± 0.16; 60, 90 and 120 min, respectively) compared to blank filter solution and 10 µg (P < 0.001). PM2.5 induced reduced cardiac conduction time, within a short period, indicating that depolarization occurs more rapidly across ventricular tissue.

Noninvasive assessment of endothelial function and ST segment changes during exercise testing in coronary artery disease

Endothelial function (EF) plays an important role in the onset and clinical course of atherosclerosis, although its relationship with the presence and extent of coronary artery disease (CAD) has not been well defined. We evaluated EF and the ST segment response to an exercise test in patients with a broad spectrum of CAD defined by coronary angiography. Sixty-two patients submitted to diagnostic catheterization for the evaluation of chest pain or ischemia in a provocative test were divided into three groups according to the presence and severity of atherosclerotic lesions (AL): group 1: normal coronaries (N = 19); group 2: CAD with AL <70% (N = 17); group 3: CAD with AL ≥70% (N = 26). EF was evaluated by the percentage of flow-mediated dilatation (%FMD) in the brachial artery during reactive hyperemia induced by occlusion of the forearm with a pneumatic cuff for 5 min. Fifty-four patients were subjected to an exercise test. Gender and age were not significantly correlated with %FMD. EF was markedly reduced in both groups with CAD (76.5 and 73.1% vs 31.6% in group 1) and a higher frequency of ischemic alterations in the ST segment (70.8%) was observed in the group with obstructive CAD with AL ≥70% during the exercise test. Endothelial dysfunction was observed in patients with CAD, irrespective of the severity of injury. A significantly higher frequency of ischemic alterations in the ST segment was observed in the group with obstructive CAD. EF and exercise ECG differed among the three groups and may provide complementary information for the assessment of CAD.

Changes in the hormone and lipid profile of obese adolescent Saudi females with acne vulgaris

Acne vulgaris is a multifactorial disease affecting a majority of the adolescent population. The objective of this study was to test for a correlation between fasting serum lipid profiles and levels of testosterone, insulin, leptin, and interleukin 1-β (IL-1β) and the incidence of severe acne vulgaris in obese adolescent females. Four groups of adolescent females were studied: obese with acne, obese without acne, non-obese with acne, and non-obese without acne. Obese females with acne, compared to obese females without acne and non-obese subjects, had significantly higher serum triglycerides, low-density lipoprotein cholesterol and apolipoprotein-B (apo-B) (mean ± SD: 197 ± 13.7 vs 171 ± 11.5, 128 ± 8.3 vs 116 ± 7.7, 96 ± 13.7 vs 85 ± 10.3 mg/dL, respectively) but significantly lower high-density lipoprotein cholesterol and apo-A1 levels (40 ± 3.3 vs 33 ± 3.5 and 126 ± 12 vs 147 ± 13 mg/dL). Serum testosterone, insulin and leptin levels were significantly higher in obese subjects with or without acne compared to non-obese females with or without acne (3 ± 0.5 vs 2.1 ± 0.47, 15.5 ± 3.3 vs 11.6 ± 3, 0.9 ± 0.2 vs 0.6 ± 0.15 nmol/mL, respectively). Serum IL-1b was significantly elevated in obese and non-obese subjects with acne compared to subjects without acne; in those without acne, these levels were higher in obese than non-obese subjects (2.4 ± 0.2, 1.4 ± 0.1 vs 1.8 ± 0.12 and 1.3 ± 0.11 pg/mL, respectively). Our results indicate that there is a relationship between obesity (BMI >27) and acne. By early recognition, the etiology and treatment protocol of acne may prevent unwanted conditions.

Changes in sodium appetite evoked by lesions of the commissural nucleus of the tractus solitarius

Ablation of the area postrema/caudal nucleus of the tractus solitarius (NTS) complex increases sodium intake, but the effect of selective lesions of the caudal NTS is not known. We measured depletion-induced sodium intake in rats with electrolytic lesions of the commissural NTS that spared the area postrema. One day after the lesion, rats were depleted of sodium with furosemide (10 mg/kg body weight, sc) and then had access to water and a sodium-deficient diet for 24 h when 1.8% NaCl was offered. Water and saline intakes were measured for 2 h. Saline intake was higher in lesioned than in sham-lesioned rats (mean ± SEM: 20 ± 2 vs 11 ± 3 mL/2 h, P < 0.05, N = 6-7). Saline intake remained elevated in lesioned rats when the tests were repeated 6 and 14 days after the lesion, and water intake in these two tests was increased as well. Water intake seemed to be secondary to saline intake both in lesioned and in sham-lesioned rats. A second group of rats was offered 10% sucrose for 2 h/day before and 2, 7, and 15 days after lesion. Sucrose intake in lesioned rats was higher than in sham-lesioned rats only 7 days after lesioning. A possible explanation for the increased saline intake in rats with commissural NTS lesions could be a reduced gastrointestinal feedback inhibition. The commissural NTS is probably part of a pathway for inhibitory control of sodium intake that also involves the area postrema and the parabrachial nucleus.

Climatic changes: what if the global increase of CO2 emissions cannot be kept under control?

Climatic changes threaten the planet. Most articles related to the subject present estimates of the disasters expected to occur, but few have proposed ways to deal with the impending menaces. One such threat is the global warming caused by the continuous increase in CO2 emissions leading to rising ocean levels due to the increasing temperatures of the polar regions. This threat is assumed to eventually cause the death of hundreds of millions of people. We propose to desalinize ocean water as a means to reduce the rise of ocean levels and to use this water for populations that need good quality potable water, precisely in the poorest regions of the planet. Technology is available in many countries to provide desalinated water at a justifiable cost considering the lives threatened both in coastal and desertified areas.

Functional changes of dendritic cells in hypersensivity reactions to amoxicillin

A better understanding of dendritic cell (DC) involvement in responses to haptenic drugs is needed, because it represents a possible approach to the development of an in vitro test, which could identify patients prone to drug allergies. There are two main DC subsets: plasmacytoid DC (pDC) and myeloid DC (mDC). β-lactams form hapten-carrier conjugates and may provide a suitable model to study DC behavior in drug allergy reactions. It has been demonstrated that drugs interact differently with DC in drug allergic and non-allergic patients, but there are no studies regarding these subsets. Our aim was to assess the functional changes of mDC and pDC harvested from an amoxicillin-hypersensitive 32-year-old woman who experienced a severe maculopapular exanthema as reflected in interleukin-6 (IL-6) production after stimulation with this drug and penicillin. We also aim to demonstrate, for the first time, the feasibility of this method for dendritic cell isolation followed by in vitro stimulation for studies of drug allergy physiopathology. DC were harvested using a double Percoll density gradient, which generates a basophil-depleted cell (BDC) suspension. Further, pDC were isolated by blood DC antigen 4-positive magnetic selection and gravity filtration through magnetized columns. After stimulation with amoxicillin, penicillin and positive and negative controls, IL-6 production was measured by ELISA. A positive dose-response curve for IL-6 after stimulation with amoxicillin and penicillin was observed for pDC, but not for mDC or BDC suspension. These preliminary results demonstrate the feasibility of this methodology to expand the knowledge of the effect of dendritic cell activation by drug allergens.

Sildenafil decreases rat tracheal hyperresponsiveness to carbachol and changes canonical transient receptor potential gene expression after antigen challenge

Inhibition of type-5 phosphodiesterase by sildenafil decreases capacitative Ca2+ entry mediated by transient receptor potential proteins (TRPs) in the pulmonary artery. These families of channels, especially the canonical TRP (TRPC) subfamily, may be involved in the development of bronchial hyperresponsiveness, a hallmark of asthma. In the present study, we evaluated i) the effects of sildenafil on tracheal rings of rats subjected to antigen challenge, ii) whether the extent of TRPC gene expression may be modified by antigen challenge, and iii) whether inhibition of type-5 phosphodiesterase (PDE5) may alter TRPC gene expression after antigen challenge. Sildenafil (0.1 µM to 0.6 mM) fully relaxed carbachol-induced contractions in isolated tracheal rings prepared from naive male Wistar rats (250-300 g) by activating the NO-cGMP-K+ channel pathway. Rats sensitized to antigen by intraperitoneal injections of ovalbumin were subjected to antigen challenge by ovalbumin inhalation, and their tracheal rings were used to study the effects of sildenafil, which more effectively inhibited contractions induced by either carbachol (10 µM) or extracellular Ca2+ restoration after thapsigargin (1 µM) treatment. Antigen challenge increased the expression of the TRPC1 and TRPC4 genes but not the expression of the TRPC5 and TRPC6 genes. Applied before the antigen challenge, sildenafil increased the gene expression, which was evaluated by RT-PCR, of TRPC1 and TRPC6, decreased TRPC5 expression, and was inert against TRPC4. Thus, we conclude that PDE5 inhibition is involved in the development of an airway hyperresponsive phenotype in rats after antigen challenge by altering TRPC gene expression.

Involvement of catecholaminergic medullary pathways in cardiovascular responses to acute changes in circulating volume

Water deprivation and hypernatremia are major challenges for water and sodium homeostasis. Cellular integrity requires maintenance of water and sodium concentration within narrow limits. This regulation is obtained through engagement of multiple mechanisms and neural pathways that regulate the volume and composition of the extracellular fluid. The purpose of this short review is to summarize the literature on central neural mechanisms underlying cardiovascular, hormonal and autonomic responses to circulating volume changes, and some of the findings obtained in the last 12 years by our laboratory. We review data on neural pathways that start with afferents in the carotid body that project to medullary relays in the nucleus tractus solitarii and caudal ventrolateral medulla, which in turn project to the median preoptic nucleus in the forebrain. We also review data suggesting that noradrenergic A1 cells in the caudal ventrolateral medulla represent an essential link in neural pathways controlling extracellular fluid volume and renal sodium excretion. Finally, recent data from our laboratory suggest that these structures may also be involved in the beneficial effects of intravenous infusion of hypertonic saline on recovery from hemorrhagic shock.

Comparative proteomics analysis of chronic atrophic gastritis: changes of protein expression in chronic atrophic gastritis without Helicobacter pylori infection

Chronic atrophic gastritis (CAG) is a very common gastritis and one of the major precursor lesions of gastric cancer, one of the most common cancers worldwide. The molecular mechanism underlying CAG is unclear, but its elucidation is essential for the prevention and early detection of gastric cancer and appropriate intervention. A combination of two-dimensional gel electrophoresis and mass spectrometry was used in the present study to analyze the differentially expressed proteins. Samples from 21 patients (9 females and 12 males; mean age: 61.8 years) were used. We identified 18 differentially expressed proteins in CAG compared with matched normal mucosa. Eight proteins were up-regulated and 10 down-regulated in CAG when compared with the same amounts of proteins in individually matched normal gastric mucosa. Two novel proteins, proteasome activator subunit 1 (PSME1), which was down-regulated in CAG, and ribosomal protein S12 (RPS12), which was up-regulated in CAG, were further investigated. Their expression was validated by Western blot and RT-PCR in 15 CAG samples matched with normal mucosa. The expression level of RPS12 was significantly higher in CAG than in matched normal gastric mucosa (P < 0.05). In contrast, the expression level of PSME1 in CAG was significantly lower than in matched normal gastric mucosa (P < 0.05). This study clearly demonstrated that there are some changes in protein expression between CAG and normal mucosa. In these changes, down-regulation of PSME1 and up-regulation of RPS12 could be involved in the development of CAG. Thus, the differentially expressed proteins might play important roles in CAG as functional molecules.

Longitudinal brain volumetric changes during one year in non-elderly healthy adults: a voxel-based morphometry study

Previous cross-sectional magnetic resonance imaging (MRI) studies of healthy aging in young adults have indicated the presence of significant inverse correlations between age and gray matter volumes, although not homogeneously across all brain regions. However, such cross-sectional studies have important limitations and there is a scarcity of detailed longitudinal MRI studies with repeated measures obtained in the same individuals in order to investigate regional gray matter changes during short periods of time in non-elderly healthy adults. In the present study, 52 healthy young adults aged 18 to 50 years (27 males and 25 females) were followed with repeated MRI acquisitions over approximately 15 months. Gray matter volumes were compared between the two times using voxel-based morphometry, with the prediction that volume changes would be detectable in the frontal lobe, temporal neocortex and hippocampus. Voxel-wise analyses showed significant (P < 0.05, family-wise error corrected) relative volume reductions of gray matter in two small foci located in the right orbitofrontal cortex and left hippocampus. Separate comparisons for males and females showed bilateral gray matter relative reductions in the orbitofrontal cortex over time only in males. We conclude that, in non-elderly healthy adults, subtle gray matter volume alterations are detectable after short periods of time. This underscores the dynamic nature of gray matter changes in the brain during adult life, with regional volume reductions being detectable in brain regions that are relevant to cognitive and emotional processes.