Modeling hypothalamic pathophysiology in vitro for metabolic, circadian, and sleep disorders.

The hypothalamus, a small and intricate brain structure, orchestrates numerous neuroendocrine functions through specialized neurons and nuclei. Disruption of this complex circuitry can result in various diseases, including metabolic, circadian, and sleep disorders. Advances in in vitro models and their integration with new technologies have significantly benefited research on hypothalamic function and pathophysiology. We explore existing in vitro hypothalamic models and address their challenges and limitations as well as translational findings. We also highlight how collaborative efforts among multidisciplinary teams are essential to develop relevant and translational experimental models capable of replicating intricate neural circuits and neuroendocrine pathways, thereby advancing our understanding of therapeutic targets and drug discovery in hypothalamus-related disorders.

Survey on antimicrobial resistance knowledge and perceptions in university students reveals concerning trends on antibiotic use and procurement.

BACKGROUND: The World Health Organization (WHO) has declared that antimicrobial resistance is one of the top ten global public health threats humanity is facing. To tackle this problem, it is necessary to not only address it in the hospital setting, but even more so in the community. In this context, understanding people's knowledge, attitudes, and practices towards antimicrobial resistance is of utmost importance. Accordingly, we investigated whether students from the Université de Montréal (Quebec, Canada) had perceptions and behaviours that could foster bacterial resistance. METHODS: We conducted an observational, cross-sectional, prospective, and descriptive study from November 30 to December 11, 2020. We applied an online questionnaire (Google Forms) adapted from the WHO survey entitled 'Antibiotic resistance: Multi-country public awareness survey.' RESULTS: Overall, 106 participants were included in this study. Most of them demonstrated reasonable understanding and behaviours related to antimicrobial resistance. Erroneous response proportions ranged from 0.9% to 25.5%, except for the statement 'Antibiotic resistance occurs when your body becomes resistant to antibiotics, and they no longer work,' where 63.2% of participants answered that it was true, even though it is false. Regarding antibiotic use, 28.3% of participants said they already had used antibiotics without a doctor's prescription. Of these, 55.2% were Canadian students. CONCLUSIONS: This study indicates a possible misuse of antimicrobials in an area where antibiotics should not be easily accessible without a prescription. It is necessary to investigate why these medications are being used without being prescribed. Furthermore, we demonstrate a need to increase public awareness to better understand antimicrobial resistance's theoretical basis.

INTRODUCTION: Selon l'Organisation mondiale de la Santé (OMS), la résistance antimicrobienne (RAM) est l'une des dix menaces sanitaires pour l'humanité. Pour faire face à ce problème, il est nécessaire de l'aborder non seulement dans le cadre hospitalier, mais encore davantage au sein de la communauté. Dans ce contexte, il est primordial de comprendre les connaissances, les attitudes et les pratiques de la population vis-à-vis de la résistance antimicrobienne. Ainsi, les chercheurs ont cherché à savoir si les perceptions et les comportements de la communauté étudiante de l'Université de Montréal (Québec, Canada) pouvaient contribuer à la propagation de la résistance bactérienne. MÉTHODES: Les chercheurs ont réalisé une étude observationnelle de type transversal, prospectif et descriptif entre le 30 novembre et le 11 décembre 2020. Ils ont utilisé un questionnaire en ligne (formulaires Google) adapté du sondage de l'OMS intitulé Antibiotic resistance: Multi-country public awareness survey. RÉSULTATS: Au total, 106 participants ont été inclus dans l'étude. La plupart ont démontré avoir une compréhension et des comportements raisonnables au sujet de la RAM. Les proportions de réponses erronées se situaient entre 0,9 % et 25,5 %, sauf pour la proposition « La résistance aux antibiotiques survient lorsque votre corps devient résistant aux antibiotiques et qu'ils ne fonctionnent plus ¼, pour laquelle 63,2 % des participants ont répondu que c'était vrai, même si c'est faux. En ce qui concerne l'utilisation des antibiotiques, 28,3 % des participants ont déclaré avoir déjà utilisé des antibiotiques sans prescription médicale, et 55,2 % d'entre eux étaient des étudiants canadiens. CONCLUSIONS: La présente étude signale la possibilité que les antimicrobiens soient mal utilisés dans une région où les antibiotiques ne devraient pas être facilement accessibles sans prescription. Une étude s'impose pour savoir pourquoi ces médicaments sont utilisés sans être prescrits. De plus, les chercheurs démontrent la nécessité de sensibiliser le public aux fondements théoriques de la résistance antimicrobienne.

SIRT2 Deficiency Exacerbates Hepatic Steatosis via a Putative Role of the ER Stress Pathway.

Nonalcoholic fatty liver disease (NAFLD), a condition strongly associated with obesity and insulin resistance, is characterized by hepatic lipid accumulation and activation of the endoplasmic reticulum (ER) stress response. The sirtuin 2 (SIRT2) protein deacetylase is emerging as a new player in metabolic homeostasis, but its role in the development of hepatic steatosis and its link with ER stress activation remains unknown. SIRT2-knockout (SIRT2-KO) and wild-type mice were fed either a control or a high-fat diet (HFD) for 4 weeks. Genetic manipulation of SIRT2 levels was performed in human hepatic cells. Although apparently normal under a control diet, SIRT2-KO mice showed accelerated body weight gain and adiposity on a HFD, accompanied by severe insulin resistance. Importantly, SIRT2-KO mice exhibited worsened hepatic steatosis independently from diet, consistent with upregulated gene expression of lipogenic enzymes and increased expression of ER stress markers. Exposure of hepatic cells to palmitate induced lipid accumulation, increased ER stress, and decreased SIRT2 expression. Moreover, SIRT2-silenced cells showed enhanced lipid accumulation and ER stress activation under basal conditions, whereas SIRT2 overexpression abrogated palmitate-induced lipid deposition and ER stress activation. Our findings reveal a role for SIRT2 in the regulation of hepatic lipid homeostasis, potentially through the ER stress response, suggesting that SIRT2 activation might constitute a therapeutic strategy against obesity and its metabolic complications.

Prolonged Outbreak of Carbapenem and Colistin-Resistant Klebsiella pneumoniae at a Large Tertiary Hospital in Brazil.

Multidrug-resistant gram-negative bacteria, such as carbapenem and colistin-resistant Klebsiella pneumoniae (ColR-CRKP), represent a major problem for health systems worldwide and have high lethality. This study investigated the genetic relationship, antimicrobial susceptibility profile, and resistance mechanisms to ColR-CRKP isolates from patients infected/colonized in a tertiary hospital in Salvador, Bahia/Brazil. From September 2016 to January 2018, 46 patients (56 ColR-CRKP positive cultures) were enrolled in the investigation but clinical and demographic data were obtained from 31 patients. Most of them were men (67.7%) and elderly (median age of 62 years old), and the median Charlson score was 3. The main comorbidities were systemic arterial hypertension (38.7%), diabetes (32.2%), and cerebrovascular disease (25.8%). The average hospitalization stay until ColR-CRKP identification in days were 35.12. A total of 90.6% used mechanical ventilation and 93.7% used a central venous catheter. Of the 31 patients who had the data evaluated, 12 had ColR-CRKP infection, and seven died (58.4%). Previous use of polymyxins was identified in 32.2% of the cases, and carbapenems were identified in 70.9%. The minimum inhibitory concentration (MIC) for colistin was > 16 µg/mL, with more than half of the isolates (55%) having a MIC of 256 µg/mL. The bla KPC gene was detected in 94.7% of the isolates, bla NDM in 16.0%, and bla GES in 1.7%. The bla OXA-48, bla VIM, and bla IMP genes were not detected. The mcr-1 test was negative in all 56 isolates. Alteration of the mgrB gene was detected in 87.5% (n = 49/56) of the isolates, and of these, 49.0% (24/49) had alteration in size probably due to IS903B, 22.4% (11/49) did not have the mgrB gene detected, 20.4% (10/49) presented the IS903B, 6.1% (3/49) had a premature stop codon (Q30*), and 2.1% (1/49) presented a thymine deletion at position 104 - 104delT (F35fs). The PFGE profile showed a monoclonal profile in 84.7% of the isolates in different hospital sectors, with ST11 (CC-258) being the most frequent sequence type. This study presents a prolonged outbreak of ColR-CRKP in which 83.9% of the isolates belonged to the same cluster, and 67.6% of the patients evaluated had not used polymyxin, suggesting the possibility of cross-transmission of ColR-CRKP isolates.

Outbreak of Stenotrophomonas maltophilia and Burkholderia cepacia Bloodstream Infections at a Hemodialysis Center.

Patients undergoing hemodialysis are at an increased risk for bloodstream infections (BSIs). Infection usually occurs because of contamination of water supply, water treatment, distribution systems, or reprocessing dialyzers. Here, we report an outbreak of BSIs caused by Stenotrophomonas maltophilia (n = 21) and Burkholderia cepacia (n = 22) among dialyzed patients at a large hemodialysis center in Brazil. Overall, three patients died (7%), two of which had bacteremia caused by S. maltophilia and the other had a B. cepacia infection. We collected water samples from different points of the hemodialysis system for culture and typing. Genetic patterns were identified through polymerase chain reaction-random amplified polymorphic DNA (PCR-RAPD) and pulsed-field gel electrophoresis. The same genotypes of S. maltophilia and B. cepacia recovered from blood cultures were found in dialysis water. Also, multiple genetic profiles were identified among water isolates, suggesting heavy contamination. Bacteremia cases persisted even after implementing standard control measures, which led us to believe that the piping system was contaminated with microbial biofilms. Soon after we changed the entire plumbing system, reported cases dropped back to the number typically expected, and the outbreak came to an end.

Bacterial diversity and prevalence of antibiotic resistance genes in the oral microbiome.

OBJECTIVES: This study aims to describe the oral microbiome diversity and prevalence of ARGs in periodontal health and disease. BACKGROUND: The human oral cavity harbors a complex microbial community known as the oral microbiome. These organisms are regularly exposed to selective pressures, such as the usage of antibiotics, which drive evolution and acquisition of antibiotic resistance genes (ARGs). Resistance among oral bacteria jeopardizes not only antibiotic therapy for oral infections, but also extra-oral infections caused by bacterial translocation. METHODS: We carried out a cross-sectional investigation. Saliva and subgingival plaque samples were collected during a clinical exam. 16S rRNA gene sequencing was performed to assess microbial diversity. Resistance genes were identified through PCR assays. RESULTS: Of the 110 participants, only 22.7% had healthy periodontium, while the majority was diagnosed with gingivitis (55.4%) and chronic periodontitis (21.8%). The composition of the oral microbiota differed from healthy and diseased samples, being Streptococcus spp. and Rothia spp. predominant in periodontal disease. Regarding ARGs, 80 (72.7%) samples were positive for at least one of genes screened, erm being the most frequent variant (58.2%), followed by blaTEM (16.4%), mecA (2.7%), pbp2b and aac(6 ') (1.8%). Neither genes coding resistance to carbapenems nor metronidazole were detected. CONCLUSIONS: Our findings indicate that there are no significant differences in terms of taxonomic enrichment between healthy and diseased oral microbiomes. However, samples retrieved from healthy patients had a more diverse microbial community, whereas diseased samples have lower taxonomic diversity. We have also identified clinically relevant ARGs, providing baseline information to guide antibiotic prescription in dentistry.

Bacterial meningitis in patients with sickle cell anemia in Salvador, Bahia, Brazil: a report on ten cases

ABSTRACT Sickle cell anemia (SCA) is a common genetic blood disorder, affecting millions worldwide. According to current evidence, individuals with SCA have more than 300 times greater risk to develop bacterial meningitis (BM) than the general population. Herein we have described the characteristics of a series of BM cases in SCA patients in Salvador, Brazil, during 13 years of hospital-based surveillance. Data on clinical presentation, laboratory parameters and outcomes were collected retrospectively by reviewing medical records. From 1999 to 2011, ten SCA patients were identified among the 2511 cases of BM (10/2511; 0.40%). These patients were more likely to be male (90%) and to be younger (median age 8.5 years). The causative agents were Streptococcus pneumoniae (n = 5) and Haemophilus influenzae (n = 1). The most frequent pneumococcal serotypes were 23 F (2 cases), 14, 18 F, 23B (one case each). Common medical complications were stroke (n = 3); heart failure (n = 2), respiratory problems (n = 2), renal dysfunctions (n = 2) and leg ulcers (n = 1). This study highlights the importance of S. pneumoniae as a causative agent of meningitis in individuals with SCA and shows the diversity of comorbidities associated with this condition.

Bacterial meningitis in patients with sickle cell anemia in Salvador, Bahia, Brazil: a report on ten cases.

Sickle cell anemia (SCA) is a common genetic blood disorder, affecting millions worldwide. According to current evidence, individuals with SCA have more than 300 times greater risk to develop bacterial meningitis (BM) than the general population. Herein we have described the characteristics of a series of BM cases in SCA patients in Salvador, Brazil, during 13 years of hospital-based surveillance. Data on clinical presentation, laboratory parameters and outcomes were collected retrospectively by reviewing medical records. From 1999 to 2011, ten SCA patients were identified among the 2511 cases of BM (10/2511; 0.40%). These patients were more likely to be male (90%) and to be younger (median age 8.5 years). The causative agents were Streptococcus pneumoniae (n=5) and Haemophilus influenzae (n=1). The most frequent pneumococcal serotypes were 23F (2 cases), 14, 18F, 23B (one case each). Common medical complications were stroke (n=3); heart failure (n=2), respiratory problems (n=2), renal dysfunctions (n=2) and leg ulcers (n=1). This study highlights the importance of S. pneumoniae as a causative agent of meningitis in individuals with SCA and shows the diversity of comorbidities associated with this condition.

Dichotomous Sirtuins: Implications for Drug Discovery in Neurodegenerative and Cardiometabolic Diseases.

Sirtuins (SIRT1-7), a class of NAD+-dependent deacylases, are central regulators of metabolic homeostasis and stress responses. While numerous salutary effects associated with sirtuin activation, especially SIRT1, are well documented, other reports show health benefits resulting from sirtuin inhibition. Furthermore, conflicting findings have been obtained regarding the pathophysiological role of specific sirtuin isoforms, suggesting that sirtuins act as 'double-edged swords'. Here, we provide an integrated overview of the different findings on the role of mammalian sirtuins in neurodegenerative and cardiometabolic disorders and attempt to dissect the reasons behind these different effects. Finally, we discuss how addressing these obstacles may provide a better understanding of the complex sirtuin biology and improve the likelihood of identifying effective and selective drug targets for a variety of human disorders.

Bloodstream infections caused by multidrug-resistant gram-negative bacteria: epidemiological, clinical and microbiological features.

BACKGROUND: Bloodstream infections (BSI) are associated with high morbidity and mortality. This scenario worsens with the emergence of drug-resistant pathogens, resulting in infections which are difficult to treat or even untreatable with conventional antimicrobials. The aim of this study is to describe the epidemiological aspects of BSI caused by multiresistant gram-negative bacilli (MDR-GNB). METHODS: We conducted a laboratory-based surveillance for gram-negative bacteremia over a 1-year period. The bacterial isolates were identified by MALDI-TOF/MS and the antimicrobial susceptibility testing was performed by VITEK®2. Resistance genes were identified through PCR assays. RESULTS: Of the 143 patients, 28.7% had infections caused by MDR-GNB. The risk factors for MDR bacteremia were male sex, age ≥ 60, previous antimicrobial use, liver disease and bacteremia caused by K. pneumoniae. K. pneumoniae was the most frequently observed causative agent and had the highest resistance level. Regarding the resistance determinants, SHV, TEM, OXA-1-like and CTX-M-gp1 were predominant enzymatic variants, whereas CTX-M-gp9, CTX-M-gp2, KPC, VIM, GES, OXA-48-like, NDM and OXA-23-like were considered emerging enzymes. CONCLUSIONS: Here we demonstrate that clinically relevant antibiotic resistance genes are prevalent in this setting. We hope our findings support the development of intervention measures by policy makers and healthcare professionals to face antibiotic resistance.

Dipeptidyl peptidase IV (DPP-IV) inhibition prevents fibrosis in adipose tissue of obese mice.

BACKGROUND: During the development of obesity the expansion of white adipose tissue (WAT) leads to a dysregulation and an excessive remodeling of extracellular matrix (ECM), leading to fibrosis formation. These ECM changes have high impact on WAT physiology and may change obesity progression. Blocking WAT fibrosis may have beneficial effects on the efficacy of diet regimen or therapeutical approaches in obesity. Since dipeptidyl peptidase IV (DPP-IV) inhibitors prevent fibrosis in tissues, such as heart, liver and kidney, the objective of this study was to assess whether vildagliptin, a DPP-IV inhibitor, prevents fibrosis in WAT in a mouse model of obesity, and to investigate the mechanisms underlying this effect. METHODS: We evaluated the inhibitory effect of vildagliptin on fibrosis markers on WAT of high-fat diet (HFD)-induced obese mice and on 3T3-L1 cell line of mouse adipocytes treated with a fibrosis inducer, transforming growth factor beta 1 (TGFß1). RESULTS: Vildagliptin prevents the increase of fibrosis markers in WAT of HFD-fed mice and reduces blood glucose, serum triglycerides, total cholesterol and leptin levels. In the in vitro study, the inhibition of DPP-IV with vildagliptin, neuropeptide Y (NPY) treatment and NPY Y1 receptor activation prevents ECM deposition and fibrosis markers increase induced by TGFß1 treatment. CONCLUSIONS: Vildagliptin prevents fibrosis formation in adipose tissue in obese mice, at least partially through NPY and NPY Y1 receptor activation. GENERAL SIGNIFICANCE: This study highlights the importance of vildagliptin in the treatment of fibrosis that occur in obesity.

Attraction of Culex mosquitoes to aldehydes from human emanations.

Anecdotes related to preferential mosquito bites are very common, but to date there is no complete explanation as to why one out of two people systematically receives more mosquito bites than the other when both are equally accessible. Here we tested the hypothesis that two constituents of skin emanations, 6-methyl-5-heptan-2-one (6-MHO) and geranylacetone (GA), are natural repellents and may account for differential attraction in different ratios. We studied skin emanations from two human subjects, confirmed in behavioral assays that female southern house mosquitoes are significantly more attracted to subject A (attractant) than to subject N (non-attractant), and tested their 6-MHO/GA ratios in a dual-choice olfactometer. Although repelling at high doses, 6-MHO/GA mixtures were not active at the levels emitted by human skin. We found, however, differential attraction elicited by the aldehydes in the ratios produced by subjects A and N. When tested in a dose commensurate with the level released from human skin and in the ratio produced by subject A, the aldehyde mixture significantly attracted mosquitoes. By contrast, an aldehyde mixture at the same ratio released by subject N did not attract mosquitoes. We, therefore, hypothesized that aldehydes may play a role in the commonly observed differential attraction.