New Evidence on BPA's Role in Adipose Tissue Development of Proinflammatory Processes and Its Relationship with Obesity.

Bisphenol A (BPA) is a xenobiotic with endocrine disruptor properties which interacts with various receptors, eliciting a cellular response. In the plastic industry, BPA is widely used in the production of polycarbonate and epoxy-phenolic resins to provide elastic properties. It can be found in the lining of canned foods, certain plastic containers, thermal printing papers, composite dental fillings, and medical devices, among other things. Therefore, it is a compound that, directly or indirectly, is in daily contact with the human organism. BPA is postulated to be a factor responsible for the global epidemic of obesity and non-communicable chronic diseases, belonging to the obesogenic and diabetogenic group of compounds. Hence, this endocrine disruptor may be responsible for the development of metabolic disorders, promoting in fat cells an increase in proinflammatory pathways and upregulating the expression and release of certain cytokines, such as IL6, IL1ß, and TNFα. These, in turn, at a systemic and local level, are associated with a chronic low-grade inflammatory state, which allows the perpetuation of the typical physiological complications of obesity.

New Insights on the Role of Connexins and Gap Junctions Channels in Adipose Tissue and Obesity.

Due to the inability to curb the excessive increase in the prevalence of obesity and overweight, it is necessary to comprehend in more detail the factors involved in the pathophysiology and to appreciate more clearly the biochemical and molecular mechanisms of obesity. Thus, understanding the biological regulation of adipose tissue is of fundamental relevance. Connexin, a protein that forms intercellular membrane channels of gap junctions and unopposed hemichannels, plays a key role in adipogenesis and in the maintenance of adipose tissue homeostasis. The expression and function of Connexin 43 (Cx43) during the different stages of the adipogenesis are differentially regulated. Moreover, it has been shown that cell-cell communication decreases dramatically upon differentiation into adipocytes. Furthermore, inhibition of Cx43 degradation or constitutive overexpression of Cx43 blocks adipocyte differentiation. In the first events of adipogenesis, the connexin is highly phosphorylated, which is likely associated with enhanced Gap Junction (GJ) communication. In an intermediate state of adipocyte differentiation, Cx43 phosphorylation decreases, as it is displaced from the membrane and degraded through the proteasome; thus, Cx43 total protein is reduced. Cx is involved in cardiac disease as well as in obesity-related cardiovascular diseases. Different studies suggest that obesity together with a high-fat diet are related to the production of remodeling factors associated with expression and distribution of Cx43 in the atrium.

Antimicrobial and Antibiofilm Capacity of Chitosan Nanoparticles against Wild Type Strain of Pseudomonas sp. Isolated from Milk of Cows Diagnosed with Bovine Mastitis.

Bovine mastitis (BM) is the most prevalent bacterial infection in the livestock sector, affecting the dairy industry greatly. The prevention and treatment of this disease is mainly made via antibiotics, but the increasing antimicrobial resistance of pathogens has affected the efficiency of conventional drugs. Pseudomonas sp. is one of the pathogens involved in this infection. The therapeutic rate of cure for this environmental mastitis-causing pathogen is practically zero, regardless of treatment. Biofilm formation has been one of the main virulence mechanisms of Pseudomonas hence presenting resistance to antibiotic therapy. We have manufactured chitosan nanoparticles (NQo) with tripolyphosphate (TPP) using ionotropic gelation. These NQo were confronted against a Pseudomonas sp. strain isolated from milk samples of cows diagnosed with BM, to evaluate their antimicrobial and antibiofilm capacity. The NQo showed great antibacterial effect in the minimum inhibitory concentrations (MIC), minimum bactericidal concentration (MBC) and disk diffusion assays. Using sub lethal concentrations, NQo were tested for inhibition of biofilm formation. The results show that the nanoparticles exhibited biofilm inhibition and were capable of eradicate pre-existing mature biofilm. These findings indicate that the NQo could act as a potential alternative to antibiotic treatment of BM.

Student experiences of two small group learning-teaching formats: Seminar and fishbowl.

INTRODUCTION: As teaching strategies, the seminar and fishbowl approaches promote active learning and shift the focus from the teacher to the learner. The aim of this study was to compare the self-reported perceptions of each student-centred teaching technique amongst a group of dental students as well as resultant quiz scores after each teaching technique. MATERIAL AND METHODS: During the first semester of 2017, all year-3 (N = 88) Semiology and year-5 (N = 71) Oral Surgery students participated in weekly seminars in which teams of students from both cohorts were given an actual clinical case to study; a diagnosis and treatment plan would be rendered, and an oral case presentation would be presented to the rest of the class. In the second semester, the same students tried to solve similar clinical cases using the fishbowl training format. A course coordinator provided final feedback, and the session culminated with a quiz. Students were invited to provide quantitative and qualitative perceptions whilst quiz scores obtained during seminar and fishbowl teaching formats were compared. RESULTS AND DISCUSSION: A total of 97 (61%) seminar and 92 (58%) fishbowl students provided insights regarding these teaching techniques. Both cohorts believed the fishbowl format allowed them to be actively involved. However, only year-3 students gave the fishbowl format a significantly higher score than the seminar format, considering it an attractive format that allowed them to learn. In contrast, year-5 students believed the seminars met their expectations better than the fishbowl format. Interesting clinical cases as well as the final round of feedback were qualitative themes reported by both cohorts. The mean seminar and fishbowl quiz scores were statistically significant different for year-3 students (P < 0.0001), but not for year-5 students (P = 0.09). CONCLUSIONS: These findings suggest that a more structured small-group learning-teaching format can be implemented for younger students whilst at the same time allowing more flexible organisation for senior students.

From cytology to histology: diagnosis of a relapsed mediastinal lymphoma by endobronchial ultrasound transbronchial histological needle.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is highly accurate in diagnosing mediastinal lymphadenopathies of lung cancer and benign disorders, with the advantage that it is a minimally invasive technique, unlike open surgery and mediastinoscopy. However, the diagnostic accuracy of EBUS-TBNA for the diagnosis of lymphoma in patients with mediastinal lymphadenopathy is not well defined. The lack of tissue architecture obtained by cytological needles decreases the diagnostic accuracy for diagnosis and subtyping of de novo and relapsed mediastinal lymphomas. We present the first described case in the literature of an anaplastic large cell lymphoma relapsed, diagnosed on tissue fragments obtained by EBUS-TBNA with the particularity of using a histological needle.

Effect of intermittent hypoxia on the reproduction of rats exposed to high altitude in the Chilean Altiplano.

Environmental parameters such as the large day-night temperature differences, high light radiation, and low humidity may have a synergistic effect with low oxygen pressure. To evaluate the effects of the exposure to intermittent chronic hypobaric hypoxia (ICHH) in nature on rat reproduction, a group of rats was alternately moved to a location at 3400 meters over sea level (moml) for 7 days and returned the subsequent week to sea level; this procedure was repeated six times. Hematological and reproductive parameters were measured and analyzed. At the end of the experimental protocol, hematocrit and hemoglobin concentrations were significantly greater in the ICHH group compared to the control group (Nx) (p < 0.05). The diameter of the seminiferous tubule and the height of the spermatogenic epithelium in ICHH rats presented a significant decrease in relation to Nx rats (p < 0.05). Consequently, the number of epididymal spermatozoa in the experimental animals decreased compared to normal rats, with no evidence of recovery after 84 days. The offspring of the different matings between normal and hypoxic animals decreased proportionally to hypoxia exposure. The low oxygen and the changes in testicular temperature homeostasis would provide a novel local mechanism to explain the decrease in sperm cell production and the reduced number of puppies born. The alterations of the reproductive parameters of the hypoxic female, plus testicular injuries and diminished sperm in males, result in a significant decrease in the reproductive activity of the animals.

Experimental antihyperglycemic effect of diterpenoids of llareta Azorella compacta (Umbelliferae) Phil in rats.

Aqueous or ethanol infusions of Azorella compacta (llareta) in common with many other plants have been used as antidiabetic in the popular medicine in the altiplanic region of Chile. In order to determine if the diterpenic compounds chemically elucidated and isolated from this plant are responsible for this effect, streptozotocin diabetic rats (507 +/- 67 mg/mL glucose) were injected with two injections of diterpenic compounds mulinolic acid, azorellanol, and mulin-11,13-dien-20-oic acid at 180 mg/mL. Glycemia of animals treated with mulinolic acid and azorellanol was decreased to 243 +/- 2 and 247 +/- 14 mg/mL respectively, values very close to those reached by chlorpropamide injection used in controls. After 3 h treatment with mulin-11,13-dien-20-oic acid no effect was detected. The blood serum insulin in diabetic rats (146 +/- 58 pg/mL) was lower than in control rats. After injection of azorellanol, insulin was elevated to 247 +/- 23 pg/mL but with mulinolic acid, insulin was not changed. The antihyperglycemic effect of these compounds may explain the effectiveness of llareta in popular medicine. Because of the similarity to the hypoglycemic medication chlorpropamide, azorellanol could be acting on the beta cells of pancreatic islets, while mulinolic acid may act upon glucose utilization or production in the liver.

Use of an "acetaldehyde clamp" in the determination of low-KM aldehyde dehydrogenase activity in H4-II-E-C3 rat hepatoma cells.

The high-affinity (K(M)<1 microM) mitochondrial class 2 aldehyde dehydrogenase (ALDH2) metabolizes most of the acetaldehyde generated in the hepatic oxidation of ethanol. H4-II-E-C3 rat hepatoma cells have been found to express ALDH2. We report a method to assess ALDH2 activity in intact hepatoma cells that does not require mitochondrial isolation. To determine only the high-affinity ALDH2 activity it is necessary to keep constant low concentrations of acetaldehyde in the cells to minimize its metabolism by high-K(M) aldehyde dehydrogenases. To maintain both low and constant concentrations of acetaldehyde we used an "acetaldehyde clamp," which keeps acetaldehyde at a concentration of 4.2+/-0.4 microM. The clamp is attained by addition of excess yeast alcohol dehydrogenase, 14C-ethanol, and oxidized form of nicotinamide adenine dinucleotide (NAD(+)) to the hepatoma cell culture medium. The concentration of 14C-acetaldehyde attained follows the equilibrium constant of the alcohol dehydrogenase reaction. Thus, 14C-acetate is generated virtually by the low-K(M) aldehyde dehydrogenase activity. 14C-acetate is separated from the culture medium by an anionic resin and its radioactivity is determined. We showed that (1) acetate production is linear for 120 min, (2) addition of 160 microM cyanamide to the culture medium leads to a 75%-80% reduction of acetate generated, and (3) ALDH2 activity is dependent on cell-to-cell contact and increases after cells reach confluence. The clamp system allows the determination of ALDH2 activity in less than one million H4-II-E-C3 rat hepatoma cells. The specificity and sensitivity of the "acetaldehyde clamp" assay should be of value in evaluation of the effects of new agents that modify Aldh2 gene expression, as well as in the study of ALDH2 regulation in intact cells.