Alcohol dehydrogenase system acts as the sole pathway for methanol oxidation in Desulfofundulus kuznetsovii strain TPOSR.

Desulfofundulus kuznetsovii is a thermophilic, spore-forming sulphate-reducing bacterium in the family Peptococcaceae. In this study, we describe a newly isolated strain of D. kuznetsovii, strain TPOSR, and compare its metabolism to the type strain D. kuznetsovii 17T. Both strains grow on a large variety of alcohols, such as methanol, ethanol and propane-diols, coupled to the reduction of sulphate. Strain 17T metabolizes methanol via two routes, one involving a cobalt-dependent methyl transferase and the other using a cobalt-independent alcohol dehydrogenase. However, strain TPOSR, which shares 97% average nucleotide identity with D. kuznetsovii strain 17T, lacks several genes from the methyl transferase operon found in strain 17T. The gene encoding the catalytically active methyl transferase subunit B is missing, indicating that strain TPOSR utilizes the alcohol dehydrogenase pathway exclusively. Both strains grew with methanol during cobalt starvation, but growth was impaired. Strain 17T was more sensitive to cobalt deficiency, due to the repression of its methyl transferase system. Our findings shed light on the metabolic diversity of D. kuznetsovii and their metabolic differences of encoding one or two routes for the conversion of methanol.

Intracranial self-stimulation reverses impaired spatial learning and regulates serum microRNA levels in a streptozotocin-induced rat model of Alzheimer disease.

BACKGROUND: The assessment of deep brain stimulation (DBS) as a therapeutic alternative for treating Alzheimer disease (AD) is ongoing. We aimed to determine the effects of intracranial self-stimulation at the medial forebrain bundle (MFB-ICSS) on spatial memory, neurodegeneration, and serum expression of microRNAs (miRNAs) in a rat model of sporadic AD created by injection of streptozotocin. We hypothesized that MFB-ICSS would reverse the behavioural effects of streptozotocin and modulate hippocampal neuronal density and serum levels of the miRNAs. METHODS: We performed Morris water maze and light-dark transition tests. Levels of various proteins, specifically amyloid-ß precurser protein (APP), phosphorylated tau protein (pTAU), and sirtuin 1 (SIRT1), and neurodegeneration were analyzed by Western blot and Nissl staining, respectively. Serum miRNA expression was measured by reverse transcription polymerase chain reaction. RESULTS: Male rats that received streptozotocin had increased hippocampal levels of pTAU S202/T205, APP, and SIRT1 proteins; increased neurodegeneration in the CA1, dentate gyrus (DG), and dorsal tenia tecta; and worse performance in the Morris water maze task. No differences were observed in miRNAs, except for miR-181c and miR-let-7b. After MFB-ICSS, neuronal density in the CA1 and DG regions and levels of miR-181c in streptozotocin-treated and control rats were similar. Rats that received streptozotocin and underwent MFB-ICSS also showed lower levels of miR-let-7b and better spatial learning than rats that received streptozotocin without MFB-ICSS. LIMITATIONS: The reversal by MFB-ICSS of deficits induced by streptozotocin was fairly modest. CONCLUSION: Spatial memory performance, hippocampal neurodegeneration, and serum levels of miR-let-7b and miR-181c were affected by MFB-ICSS under AD-like conditions. Our results validate the MFB as a potential target for DBS and lend support to the use of specific miRNAs as promising biomarkers of the effectiveness of DBS in combatting AD-associated cognitive deficits.

Acetic acid stress response of the acidophilic sulfate reducer Acididesulfobacillus acetoxydans.

Acid mine drainage (AMD) waters are a severe environmental threat, due to their high metal content and low pH (pH <3). Current technologies treating AMD utilize neutrophilic sulfate-reducing microorganisms (SRMs), but acidophilic SRM could offer advantages. As AMDs are low in organics these processes require electron donor addition, which is often incompletely oxidized into organic acids (e.g., acetic acid). At low pH, acetic acid is undissociated and toxic to microorganisms. We investigated the stress response of the acetotrophic Acididesulfobacillus acetoxydans to acetic acid. A. acetoxydans was cultivated in bioreactors at pH 5.0 (optimum). For stress experiments, triplicate reactors were spiked until 7.5 mM of acetic acid and compared with (non-spiked) triplicate reactors for physiological, transcriptomic, and membrane lipid changes. After acetic acid spiking, the optical density initially dropped, followed by an adaptation phase during which growth resumed at a lower growth rate. Transcriptome analysis revealed a downregulation of genes involved in glutamate and aspartate synthesis following spiking. Membrane lipid analysis revealed a decrease in iso and anteiso fatty acid relative abundance; and an increase of acetyl-CoA as a fatty acid precursor. These adaptations allow A. acetoxydans to detoxify acetic acid, creating milder conditions for other microorganisms in AMD environments.

EEG signals from tinnitus sufferers at identifying their sound tinnitus.

The present database contains brain activity of subjective tinnitus sufferers at identifying their sound tinnitus. The main objective of this database is to provide spontaneous Electroencephalographic (EEG) activity at rest, and evoked EEG activity when tinnitus sufferers attempt to identify their sound tinnitus among 54 tinnitus sound examples. For the database, 37 volunteers were recruited: 15 ones without tinnitus (Control Group - CG), and 22 ones with tinnitus (Tinnitus Group - TG). For EEG recording, 30 channels were used to record two conditions: 1) basal condition, where the volunteer remained in a state of rest with the open eyes for two minutes; and 2) active condition, where the volunteer must have identified his/her sound stimulus by pressing a key. For the active condition, a sound-tinnitus library was generated in accordance with the most typical acoustic properties of tinnitus. The library consisted in ten pure tones (250 Hz, 500 Hz, 1 kHz, 2 kHz, 3 kHz, 3.5 kHz, 4 kHz, 6 kHz, 8 kHz, 10 kHz), a White Noise (WN), a Narrow Band noise-High frequencies (NBH, 4 kHz-10 kHz), a Narrow Band noise-Medium frequencies (NBM,1 kHz-4 kHz), a Narrow-Band noise Low frequencies (NBL, 250 Hz-1 kHz), ten pure tones combined with WN, ten pure tones superimposed with NBH, ten tones with NBM and ten pure tones combined with NBL. In total, 54 sound-tinnitus were applied for both groups. In the case of CG, volunteers must have identified a sound at 3.5 kHz. In addition to EEG information, a csv-file with audiometric and psychoacoustic information of volunteers is provided. For TG, this information refers to: 1) hearing level, 2) type of tinnitus, 3) tinnitus frequency, 4) tinnitus perception, 5) Hospital Anxiety and Depression Scale (HADS) and 6) Tinnitus Functional Index (TFI). For CG, the information refers to: 1) hearing level, and 2) HADS.

A novel mechanism for dissimilatory nitrate reduction to ammonium in Acididesulfobacillus acetoxydans.

The biological route of nitrate reduction has important implications for the bioavailability of nitrogen within ecosystems. Nitrate reduction via nitrite, either to ammonium (ammonification) or to nitrous oxide or dinitrogen (denitrification), determines whether nitrogen is retained within the system or lost as a gas. The acidophilic sulfate-reducing bacterium (aSRB) Acididesulfobacillus acetoxydans can perform dissimilatory nitrate reduction to ammonium (DNRA). While encoding a Nar-type nitrate reductase, A. acetoxydans lacks recognized nitrite reductase genes. In this study, A. acetoxydans was cultivated under conditions conducive to DNRA. During cultivations, we monitored the production of potential nitrogen intermediates (nitrate, nitrite, nitric oxide, hydroxylamine, and ammonium). Resting cell experiments were performed with nitrate, nitrite, and hydroxylamine to confirm their reduction to ammonium, and formed intermediates were tracked. To identify the enzymes involved in DNRA, comparative transcriptomics and proteomics were performed with A. acetoxydans growing under nitrate- and sulfate-reducing conditions. Nitrite is likely reduced to ammonia by the previously undescribed nitrite reductase activity of the NADH-linked sulfite reductase AsrABC, or by a putatively ferredoxin-dependent homolog of the nitrite reductase NirA (DEACI_1836), or both. We identified enzymes and intermediates not previously associated with DNRA and nitrosative stress in aSRB. This increases our knowledge about the metabolism of this type of bacteria and helps the interpretation of (meta)genome data from various ecosystems on their DNRA potential and the nitrogen cycle.IMPORTANCENitrogen is crucial to any ecosystem, and its bioavailability depends on microbial nitrogen-transforming reactions. Over the recent years, various new nitrogen-transforming reactions and pathways have been identified, expanding our view on the nitrogen cycle and metabolic versatility. In this study, we elucidate a novel mechanism employed by Acididesulfobacillus acetoxydans, an acidophilic sulfate-reducing bacterium, to reduce nitrate to ammonium. This finding underscores the diverse physiological nature of dissimilatory reduction to ammonium (DNRA). A. acetoxydans was isolated from acid mine drainage, an extremely acidic environment where nitrogen metabolism is poorly studied. Our findings will contribute to understanding DNRA potential and variations in extremely acidic environments.

Family Involvement and at-Home Physical Therapy on Duchenne Muscular Dystrophy: A Randomized Controlled Trial.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a genetic condition that causes muscle weakness and begins in early childhood. To treat its complications, the rehabilitation program includes physical therapy, mainly on the musculoskeletal and the respiratory complications that appear on the evolution of the disease. This study aims to explore the effects of physical therapy with or without an at-home program on motor function among children with DMD. METHODS: A randomized controlled trial was carried out for one year (one group with at-home and conventional physical therapy and another with conventional physical therapy). Motor function was measured using the Motor Function Measure (MFM) scale, the Vignos and Brooke scales, the Timed-up-and-Go test, and the six-minute walk distance test. RESULTS: Twenty-seven participants with DMD participated in this study. In the at-home and conventional physical therapy group, better motor function at the distal and global level was maintained, per the results of the MFM scale (P < 0.05). The rest of the variables did not achieve statistically significant changes. CONCLUSIONS: Our results suggest that complementing conventional treatment with at-home treatment in which the family is involved maintains better motor function, in participants with DMD.

De Novo Donor-Specific Antibodies after Heart Transplantation: A Comprehensive Guide for Clinicians.

Antibodies directed against donor-specific human leukocyte antigens (HLAs) can be detected de novo after heart transplantation and play a key role in long-term survival. De novo donor-specific antibodies (dnDSAs) have been associated with cardiac allograft vasculopathy, antibody-mediated rejection, and mortality. Advances in detection methods and international guideline recommendations have encouraged the adoption of screening protocols among heart transplant units. However, there is still a lack of consensus about the correct course of action after dnDSA detection. Treatment is usually started when antibody-mediated rejection is present; however, some dnDSAs appear years before graft failure is detected, and at this point, damage may be irreversible. In particular, class II, anti-HLA-DQ, complement binding, and persistent dnDSAs have been associated with worse outcomes. Growing evidence points towards a more aggressive management of dnDSA. For that purpose, better diagnostic tools are needed in order to identify subclinical graft injury. Cardiac magnetic resonance, strain techniques, or coronary physiology parameters could provide valuable information to identify patients at risk. Treatment of dnDSA usually involves plasmapheresis, intravenous immunoglobulin, immunoadsorption, and ritxumab, but the benefit of these therapies is still controversial. Future efforts should focus on establishing effective treatment protocols in order to improve long-term survival of heart transplant recipients.

SuRxgWell: study protocol for a randomized controlled trial of telemedicine-based digital cognitive behavioral intervention for high anxiety and depression among patients undergoing elective hip and knee arthroplasty surgery.

BACKGROUND: Mood disorders (anxiety, depression), sleep disorders, and catastrophizing lead to increased post-operative pain perception, increase in postoperative opioid consumption, decreased engagement with physical activity, and increased resource utilization in surgical patients. Psychosocial disorders significantly affect postoperative outcome. Unfortunately, studies focused on perioperative psychological assessment and treatment are scarce. We propose to test whether digital cognitive behavioral intervention (dCBI) can help surgical patients. dCBI such as RxWell™ is a proven treatment for mood disorders in medical patients such as reducing depression in patients with inflammatory bowel disease. We hypothesize that RxWell™ will also be effective in surgical patients. This study aims to test whether RxWell™ can improve preoperative mood disorders and subsequently reduce postoperative pain and opioid requirement in patients scheduled for primary total hip and knee arthroplasty (THA, TKA). We named the trial as the SuRxgWell trial. METHODS: This is a randomized, controlled trial that will enroll primary and unilateral THA or TKA patients with anxiety and/or depression symptoms before surgery to receive the SuRxgWell dCBI program and investigate its impact on postoperative outcomes including postoperative pain, anxiety, depression, sleep disorder, and catastrophizing. After signing an informed consent, subjects will be screened using the PROMIS questionnaires, and subjects with a T-score of ≥ 60 on the short Patient-Reported Outcomes Measurement Information System (PROMIS) 4a Anxiety and/or short PROMIS 4a Depression questionnaires will be randomized to either usual care (control group) or the cognitive behavioral intervention, RxWell™, plus usual care (intervention group). The control group will receive information on how to locate tools to address anxiety and depression, whereas the intervention group will have access to SuRxgWell 1 month prior to surgery and up to 3 months after surgery. The allocation will be 3:1 (intervention to control). Investigators will be blinded, but research coordinators approaching patients and research subjects will not. The primary outcome will be day of surgery anxiety or depression symptoms measured with the PROMIS Short Form v1.0 -Anxiety 4a/Depression and Generalized Anxiety Disorder Measure (GAD-7) and Patient Health Questionnaire (PHQ-8). Secondary end points include measuring other health-related quality of life outcomes including sleep disturbance, fatigue, ability to participate in social roles, pain interference, cognitive function, pain catastrophizing, and physical function. Other secondary outcomes include collecting data about preoperative and postoperative pain scores, and pain medication usage, and orthopedic functional recovery at baseline, day of surgery, and 1, 2, and 3 months after the surgery with the Pain Catastrophizing Scale, the Knee injury and Osteoarthritis Outcome Score (KOOS), and Hip injury and Osteoarthritis Outcome Score (HOOS). In addition, subjects will be asked to complete a GAD-7 and PHQ-8 questionnaires bi-weekly (via the RxWell™ app for the interventional group or REDCAP for the control group). Data about postsurgical complications, and resource utilization will also be recorded. We will also receive monthly reports measuring the usage and engagement of RxWell use for each participant randomized to that arm. The primary hypotheses will be assessed with intention-to-treat estimates, and differences in primary outcome will be tested using independent two sample t-tests. This trial is registered to the ClinicalTrials.gov database (NCT05658796) and supported by the DAPM, UPMC Health Plan, and the NIH. DISCUSSION: Our trial will evaluate the feasibility of digital cognitive behavioral intervention as a perioperative tool to improve anxiety and depression before and after major orthopedic surgery in comparison to education. If digital cognitive behavioral intervention proves to be effective, this might have important clinical implications, reducing the incidence of chronic postsurgical pain and improving outcomes.

Disruption of Aldehyde Dehydrogenase 2 protects against bacterial infection.

The ALDH2*2 (rs671) allele is one of the most common genetic mutations in humans, yet the positive evolutionary selective pressure to maintain this mutation is unknown, despite its association with adverse health outcomes. ALDH2 is responsible for the detoxification of metabolically produced aldehydes, including lipid-peroxidation end products derived from inflammation. Here, we demonstrate that host-derived aldehydes 4-hydroxynonenal (4HNE), malondialdehyde (MDA), and formaldehyde (FA), all of which are metabolized by ALDH2, are directly toxic to the bacterial pathogens Mycobacterium tuberculosis and Francisella tularensis at physiological levels. We find that Aldh2 expression in macrophages is decreased upon immune stimulation, and that bone marrow-derived macrophages from Aldh2 -/- mice contain elevated aldehydes relative to wild-type mice. Macrophages deficient for Aldh2 exhibited enhanced control of Francisella infection. Finally , mice lacking Aldh2 demonstrated increased resistance to pulmonary infection by M. tuberculosis , including in a hypersusceptible model of tuberculosis, and were also resistant to Francisella infection. We hypothesize that the absence of ALDH2 contributes to the host's ability to control infection by pathogens such as M. tuberculosis and F. tularensis , and that host-derived aldehydes act as antimicrobial factors during intracellular bacterial infections. One sentence summary: Aldehydes produced by host cells contribute to the control of bacterial infections.

Redox gradient shapes the abundance and diversity of mercury-methylating microorganisms along the water column of the Black Sea.

In the global context of seawater deoxygenation triggered by climate change and anthropogenic activities, changes in redox gradients impacting biogeochemical transformations of pollutants, such as mercury, become more likely. Being the largest anoxic basin worldwide, with high concentrations of the potent neurotoxic methylmercury (MeHg), the Black Sea is an ideal natural laboratory to provide new insights about the link between dissolved oxygen concentration and hgcAB gene-carrying (hgc+) microorganisms involved in the formation of MeHg. We combined geochemical and microbial approaches to assess the effect of vertical redox gradients on abundance, diversity, and metabolic potential of hgc+ microorganisms in the Black Sea water column. The abundance of hgcA genes [congruently estimated by quantitative PCR (qPCR) and metagenomics] correlated with MeHg concentration, both maximal in the upper part of the anoxic water. Besides the predominant Desulfobacterales, hgc+ microorganisms belonged to a unique assemblage of diverse-previously underappreciated-anaerobic fermenters from Anaerolineales, Phycisphaerae (characteristic of the anoxic and sulfidic zone), Kiritimatiellales, and Bacteroidales (characteristic of the suboxic zone). The metabolic versatility of Desulfobacterota differed from strict sulfate reduction in the anoxic water to reduction of various electron acceptors in the suboxic water. Linking microbial activity and contaminant concentration in environmental studies is rare due to the complexity of biological pathways. In this study, we disentangle the role of oxygen in shaping the distribution of Hg-methylating microorganisms consistently with MeHg concentration, and we highlight their taxonomic and metabolic niche partitioning across redox gradients, improving the prediction of the response of marine communities to the expansion of oxygen-deficient zones. IMPORTANCE Methylmercury (MeHg) is a neurotoxin detected at high concentrations in certain marine ecosystems, posing a threat to human health. MeHg production is mainly mediated by hgcAB gene-carrying (hgc+) microorganisms. Oxygen is one of the main factors controlling Hg methylation; however, its effect on the diversity and ecology of hgc+ microorganisms remains unknown. Under the current context of seawater deoxygenation, mercury cycling is expected to be disturbed. Here, we show the strong effect of oxygen gradients on the distribution of potential Hg methylators. In addition, we show for the first time the significant contribution of a unique assemblage of potential fermenters from Anaerolineales, Phycisphaerae, and Kiritimatiellales to Hg methylation, stratified in different redox niches along the Black Sea gradient. Our results considerably expand the known taxonomic diversity and ecological niches prone to the formation of MeHg and contribute to better apprehend the consequences of oxygen depletion in seawater.

Near-infrared fluorescence cholangiography in dogs: A pilot study.

OBJECTIVE: To determine the effect of indocyanine green (ICG) dose and timing of administration on near-infrared fluorescence (NIRF) imaging of the normal canine biliary tree. STUDY DESIGN: Preclinical prospective study. ANIMALS: Eight purpose-bred beagles. METHODS: The dogs were randomized to receive two of four intravenous ICG dose (low [L]:0.05 mg/kg or high [H]:0.25 mg/kg)/time (0 and 3 h prior to NIRF) combinations. NIRF images were collected every 10 min for 120 min. Target (cystic duct)-to-background (liver) ratios were calculated for all timepoints and compared. RESULTS: ICG cholangiography was successful in all dogs. The contrast ratio was above 1 in the L0 group by 20 min and reached its peak at 100 min. In the H0 group, the ratio was above 1 by 60 min and reached its peak at 90 min. Contrast ratios above 2 (fluorescence twice as bright in the cystic duct compared to the liver) were maintained from 180 to 300 min for L3 and H3 and was achieved after 80 min for L0. CONCLUSION: Low dose ICG provided better ratios early after injection compared to the high dose which remained highly concentrated in the liver tissue after injection. Both doses provided excellent visualization of the biliary tree at 3 h post injection, low dose ICG provided better ratios from 3 to 5 h post injection. Based on these results, 0.05 mg/kg of ICG administered at anesthetic premedication, or as early as 3 h prior to laparoscopic surgery should yield optimal fluorescence images. CLINICAL SIGNIFICANCE: This study provides guidelines for NIRF cholangiography in clinically normal dogs.

Rostral spread of lumbosacral epidural volumes of dye and contrast medium calculated using body weight or length of the vertebral column in dog cadavers.

The objective of this study was to compare the rostral spread of lumbosacral epidural volumes of a mixture of dye and contrast medium, calculated using body weight (BW) or vertebral column length (LE), in 22 dog cadavers. The dogs weighed 4.6 to 52.0 kg. Dogs were paired within a < 10% difference for BW and LE and with the same body condition score (BCS). Pairs of dogs were injected while in sternal recumbency through an epidural catheter with a volume mixture of iopamidol and dye, calculated based on BW: 0.2 mL/kg in one of the cadavers and based on LE: 0.05 mL/cm (< 50 cm), 0.07 mL/cm (50 to < 70 cm), 0.08 mL/cm (70 to < 80 cm), and 0.11 mL/cm (≥ 80 cm) in the other cadaver. The extent of rostral spread was determined using computed tomography for iopamidol and anatomical dissection for dye. Comparisons for dye and iopamidol within each dog, and for BW and LE within matched pairs, were completed with mixed linear models (P < 0.05). The number of vertebrae reached by dye was greater than the number reached by iopamidol in both BW and LE, but the rostral spread was not significantly different between BW and LE for all pairs. In conclusion, dye tends to spread further than iopamidol and therefore, these two methods should not be considered interchangeable when used in research studies.

L'objectif de cette étude était de comparer l'étalement rostral des volumes épiduraux lombo-sacrés d'un mélange de colorant et de produit de contraste, calculé en utilisant le poids corporel (PC) ou la longueur de la colonne vertébrale (LE), chez 22 cadavres de chiens. Les chiens pesaient de 4,6 à 52,0 kg. Les chiens ont été appariés avec une différence < 10 % pour PC et LE et avec le même score d'état corporel (PCS). Des paires de chiens ont reçu une injection alors qu'ils étaient en décubitus sternal à travers un cathéter péridural avec un mélange volumique d'iopamidol et de colorant, calculé sur la base du poids corporel : 0,2 mL/kg dans l'un des cadavres et sur la base de la LE : 0,05 mL/cm (< 50 cm), 0,07 mL/cm (50 à < 70 cm), 0,08 mL/cm (70 à < 80 cm) et 0,11 mL/cm (≥ 80 cm) dans l'autre cadavre. L'étendue de la propagation rostrale a été déterminée par tomodensitométrie pour l'iopamidol et dissection anatomique pour le colorant. Les comparaisons pour le colorant et l'iopamidol au sein de chaque chien, et pour PC et LE au sein de paires appariées, ont été complétées avec des modèles linéaires mixtes (P < 0,05). Le nombre de vertèbres atteintes par le colorant était supérieur au nombre atteint par l'iopamidol dans PC et LE, mais la propagation rostrale n'était pas significativement différente entre PC et LE pour toutes les paires. En conclusion, le colorant a tendance à se propager plus loin que l'iopamidol et, par conséquent, ces deux méthodes ne doivent pas être considérées comme interchangeables lorsqu'elles sont utilisées dans des études de recherche.(Traduit par Docteur Serge Messier).

Comparison of rostral spread of lumbosacral epidural volume calculated by body weight or length of the vertebral column in small-sized anesthetized dogs.

The first objective of this prospective, randomized, crossover experimental trial was to compare the rostral spread of lumbosacral epidural volume calculated by body weight (BW) or vertebral column length (LE) in 6 small, isoflurane-anesthetized female beagle dogs (BW: 7.5 to 10.2 kg; LE measured from the occipital crest to the sacrococcygeal space: 46 to 56 cm). The second objective was to assess the response to a noxious stimulus once the dogs recovered from anesthesia and to determine the effects of the injection on cardiopulmonary variables. While in sternal position, dogs were injected through an epidural catheter with a volume mixture of bupivacaine 0.25% and iopamidol 15% based on BW: 0.2 mL/kg or LE: 0.05 mL/cm (< 50 cm) or 0.07 mL/cm (50 to < 70 cm). Rostral spread was determined by counting the number of vertebrae reached by iopamidol using computed tomography. After anesthesia, cardiopulmonary variables, motor function, and responses to nociceptive stimuli were evaluated. Comparisons were completed with mixed linear models and 2-way analysis of variance (ANOVA) (P < 0.05). The volume of injectate (3.29 ± 0.74 versus 1.81 ± 0.21 mL; mean ± SD) and the number of vertebrae (22 ± 2 versus 19 ± 2 vertebrae) reached by iopamidol were significantly greater for LE than for BW. Response to nociception, time to return of pain sensation, motor function, and cardiopulmonary variables were similar between groups. In conclusion, dosing based on LE resulted in larger rostral spread than when based on BW in dogs of small size.

Le premier objectif de cet essai expérimental croisé prospectif randomisé était de comparer la propagation rostrale du volume épidural lombo-sacré calculé en fonction du poids corporel (PC) ou de la longueur de la colonne vertébrale (LE) chez 6 petites chiennes beagle anesthésiées à l'isoflurane (PC : 7,5 à 10,2 kg; LE mesuré de la crête occipitale à l'espace sacro-coccygien : 46 à 56 cm). Le deuxième objectif était d'évaluer la réponse à un stimulus nocif une fois que les chiens se sont remis de l'anesthésie et de déterminer les effets de l'injection sur les variables cardiopulmonaires. En position sternale, les chiens ont reçu une injection via un cathéter péridural d'un mélange volumique de bupivacaïne à 0,25 % et d'iopamidol à 15 % basé sur le poids corporel : 0,2 mL/kg ou LE : 0,05 mL/cm (< 50 cm) ou 0,07 mL/cm (50 à < 70 cm). La propagation rostrale a été déterminée en comptant le nombre de vertèbres atteintes par l'iopamidol en utilisant la tomodensitométrie. Après l'anesthésie, les variables cardiopulmonaires, la fonction motrice et les réponses aux stimuli nociceptifs ont été évaluées. Les comparaisons ont été complétées avec des modèles linéaires mixtes et une analyse de variance à 2 facteurs (ANOVA) (P < 0,05). Le volume d'injectat (3,29 ± 0,74 versus 1,81 ± 0,21 mL; moyenne ± SD) et le nombre de vertèbres (22 ± 2 versus 19 ± 2 vertèbres) atteints par l'iopamidol étaient significativement plus élevés pour LE que pour BW. La réponse à la nociception, le temps de retour de la sensation de douleur, la fonction motrice et les variables cardiopulmonaires étaient similaires entre les groupes. En conclusion, le dosage basé sur LE a entraîné une plus grande propagation rostrale que lorsqu'il était basé sur BW chez les chiens de petite taille.(Traduit par Docteur Serge Messier).

Relation among, trait anxiety, intolerance to uncertainty and early maltreatment experiences on fear discrimination learning and avoidance generalization online task.

BACKGROUND AND OBJECTIVES: Early aversive experiences, which have been associated with elevated anxiety and intolerance of uncertainty (IUS), may contribute negatively to fear conditioning learning. The aim of the present study was to analyze the relation among individual differences in childhood maltreatment experiences, trait anxiety, and IUS in adulthood; and to determine how these variables could affect fear learning discrimination and avoidance generalization. METHODS: We adapted an avoidance procedure in an online fear learning task. Two pictures of different lamp colors (CS+) were first associated with two aversive images (US), while a third color was not (CS-). Next, clicking a button during one CS + could effectively avoid the US (CS + av), but not during the other (CS + unav). Finally, avoidance generalization was tested to lamp colors that were between CS- and CS + av (safety dimension) and CS + av and CS + unav (avoidability dimension). With a sample of 67 participants, we measured ratings of relief, expectancy, and anxiety, as well as button presses and individual differences (STAI, IUS and MAES). RESULTS: Aversive early experiences were positively related to trait anxiety and intolerance of uncertainty. The results of the task further suggested that maltreatment experience contributes to be more attentive to aversive signals, which could be implicated in leading to difficulties in discrimination learning. LIMITATIONS: Online experiments implies some loss of control over subjects and environment that can threaten internal validity. Likewise, the commitment of participants may be low. CONCLUSIONS: Results suggest that early aversive experience and anxiety could contribute to the development of IUS, which likely contributes to the development of avoidance behavior.

Misinformation messages shared via WhatsApp in Mexico during the COVID-19 pandemic: an exploratory study.

Little is known about the role of WhatsApp in spreading misinformation during the start of the COVID-19 pandemic in Mexico. The aim of this study is to analyze the message content, format, authorship, time trends and social media distribution channels of misinformation in WhatsApp messages in Mexico. From March 18 to June 30, 2020 the authors collected all WhatsApp messages received via their personal contacts and their social networks that contained information about COVID-19. Descriptive and inferential statistics were used to analyze the scientifically inaccurate messages and the relationship between variables, respectively. Google image and video searches were carried out to identify sharing on other social media. Out of a total of 106 messages, the most frequently mentioned COVID-19 related message topics were prevention (20.0%), conspiracy (18.5%), therapy (15.4%) and origin of the virus (10.3%), changing throughout the pandemic according to users' concerns. Half of all WhatsApp messages were either images or videos. WhatsApp images were also shared on Facebook (80%) and YouTube (~50%). Our findings indicate that the design of information and health promotion campaigns requires to be proactive in adapting to the changes in message content and format of misinformation shared through encrypted social media.

As an encrypted social media platform with hardly accessible content, little is known about the role of WhatsApp in spreading misinformation messages (either false or misleading information) during the COVID-19 pandemic in Mexico. In this study, researchers studied the content, format, time and channel of distribution of WhatsApp messages containing information about COVID-19 collected via their personal contacts and their social networks from March 18 to June 30, 2020. Half of all messages were visually-appealing and the content changed according to the population´s concerns. WhatsApp messages were also distributed in several other social media platforms. Understanding the format and content of misinformation may help to design dynamic health information and promotion campaigns against it. Regulations of public social media such as Youtube can have a positive impact on WhatsApp.