Pleistocene climate oscillations have shaped the expansion and contraction speciation model of the globose Eriosyce sect. Neoporteria cacti in Central Chile.

BACKGROUND AND AIMS: Pleistocene climatic oscillations, characterized by arid (interglacial) and pluvial (glacial) phases, have profoundly impacted the floras of Mediterranean climates. Our study investigates the hypothesis that these climatic extremes have promoted phases of range expansion and contraction in the Eriosyce sect. Neoporteria, resulting in pronounced genetic structuring and restricted gene flow. METHODS: Utilizing nuclear microsatellite markers, we genotyped 251 individuals across 18 populations, encompassing all 14 species and one subspecies within the Eriosyce sect. Neoporteria. Additionally, Species Distribution Models (SDMs) were employed to reconstruct past (Last Interglacial, Last Glacial Maximum, Mid-Holocene) and current potential distribution patterns, aiming to delineate the climatic influences on species' range dynamics. KEY RESULTS: The gene flow analysis disclosed disparate levels of genetic interchange among species, with marked restrictions observed between entities that are geographically or ecologically separated. Notably, E. subgibbosa from Hualpen emerged as genetically distinct, warranting its exclusion for clearer genetic clustering into north, central, and south clusters. The SDMs corroborated these findings, showing marked range expansions during warmer periods and contractions during colder times, indicating significant shifts in distribution patterns in response to climatic changes. CONCLUSIONS: Our findings emphasize the critical role of Pleistocene climatic fluctuations in driving the dynamic patterns of range expansions and contractions that have led to geographic isolation and speciation within the Eriosyce sect. Neoporteria. Even in the face of ongoing gene flow, these climate-driven processes have played a pivotal role in sculpting the species' genetic architecture and diversity. This study elucidates the complex interplay between climatic variability and evolutionary dynamics among Mediterranean cacti in central Chile, highlighting the necessity of considering historical climatic millenial oscillations in conservation and evolutionary biology studies.

An unusual manifestation of Langerhans cell histiocytosis in the gastrointestinal tract.

Langerhans cell histiocytosis (LCH) is a monoclonal proliferative disease that can affect multiple organs. It is a rare disorder, and children are the most commonly affected. Its classification depends on whether the disease is localized (usually bone or skin) or systemic. We present the case of a 49-year-old woman with a previous diagnosis of LCH in 2018 with only cutaneous involvement, managed with topical corticosteroids. After developing hypertransaminasemia, a PET-CT scan was performed, showing dissemination of the disease with bone, hepatosplenic and gynecological involvement. In addition, hypermetabolic lesions were described in the cecum with ileocecal adenopathies. A colonoscopy was performed showing in the cecum and ascending colon multiple sessile polyps of 5-10mm with central fibrin-coated erosions, from which biopsies were obtained. Histology revealed typical features of LCH with positive staining for CD1A, S100 and Langerin.

Somatosensory Evoked Potentials Reveal Reduced Embodiment of Emotions in Autism.

Consistent with current models of embodied emotions, this study investigates whether the somatosensory system shows reduced sensitivity to facial emotional expressions in autistic compared with neurotypical individuals, and whether these differences are independent from between-group differences in visual processing of facial stimuli. To investigate the dynamics of somatosensory activity over and above visual carryover effects, we recorded EEG activity from two groups of autism spectrum disorder (ASD) or typically developing (TD) humans (male and female), while they were performing a facial emotion discrimination task and a control gender task. To probe the state of the somatosensory system during face processing, in 50% of trials we evoked somatosensory activity by delivering task-irrelevant tactile taps on participants' index finger, 105 ms after visual stimulus onset. Importantly, we isolated somatosensory from concurrent visual activity by subtracting visual responses from activity evoked by somatosensory and visual stimuli. Results revealed significant task-dependent group differences in mid-latency components of somatosensory evoked potentials (SEPs). ASD participants showed a selective reduction of SEP amplitudes (P100) compared with TD during emotion task; and TD, but not ASD, showed increased somatosensory responses during emotion compared with gender discrimination. Interestingly, autistic traits, but not alexithymia, significantly predicted SEP amplitudes evoked during emotion, but not gender, task. Importantly, we did not observe the same pattern of group differences in visual responses. Our study provides direct evidence of reduced recruitment of the somatosensory system during emotion discrimination in ASD and suggests that this effect is not a byproduct of differences in visual processing.SIGNIFICANCE STATEMENT The somatosensory system is involved in embodiment of visually presented facial expressions of emotion. Despite autism being characterized by difficulties in emotion-related processing, no studies have addressed whether this extends to embodied representations of others' emotions. By dissociating somatosensory activity from visual evoked potentials, we provide the first evidence of reduced recruitment of the somatosensory system during emotion discrimination in autistic participants, independently from differences in visual processing between typically developing and autism spectrum disorder participants. Our study uses a novel methodology to reveal the neural dynamics underlying difficulties in emotion recognition in autism spectrum disorder and provides direct evidence that embodied simulation of others' emotional expressions operates differently in autistic individuals.

Pharmacological activation of insulin-degrading enzyme improves insulin secretion and glucose tolerance in diet-induced obese mice.

AIM: To investigate the use of synthetic preimplantation factor (sPIF) as a potential therapeutic tool for improving glucose-stimulated insulin secretion (GSIS), glucose tolerance and insulin sensitivity in the setting of diabetes. MATERIALS AND METHODS: We used a preclinical murine model of type 2 diabetes (T2D) induced by high-fat diet (HFD) feeding for 12 weeks. Saline or sPIF (1 mg/kg/day) was administered to mice by subcutaneously implanted osmotic mini-pumps for 25 days. Glucose tolerance, circulating insulin and C-peptide levels, and GSIS were assessed. In addition, ß-cells (Min-6) were used to test the effects of sPIF on GSIS and insulin-degrading enzyme (IDE) activity in vitro. The effect of sPIF on GSIS was also tested in human islets. RESULTS: GSIS was enhanced 2-fold by sPIF in human islets ex vivo. Furthermore, continuous administration of sPIF to HFD mice increased circulating levels of insulin and improved glucose tolerance, independently of hepatic insulin clearance. Of note, islets isolated from mice treated with sPIF exhibited restored ß-cell function. Finally, genetic (shRNA-IDE) or pharmacological (6bK) inactivation of IDE in Min-6 abolished sPIF-mediated effects on GSIS, showing that both the protein and its protease activity are required for its action. CONCLUSIONS: We conclude that sPIF is a promising secretagogue for the treatment of T2D.

Effects of saturated versus unsaturated fatty acids on metabolism, gliosis, and hypothalamic leptin sensitivity in male mice.

BACKGROUND: Development of obesity and its comorbidities is not only the result of excess energy intake, but also of dietary composition. Understanding how hypothalamic metabolic circuits interpret nutritional signals is fundamental to advance towards effective dietary interventions. OBJECTIVE: We aimed to determine the metabolic response to diets enriched in specific fatty acids. METHODS: Male mice received a diet enriched in unsaturated fatty acids (UOLF) or saturated fatty acids (SOLF) for 8 weeks. RESULTS: UOLF and SOLF mice gained more weight and adiposity, but with no difference between these two groups. Circulating leptin levels increased on both fatty acid-enriched diet, but were higher in UOLF mice, as were leptin mRNA levels in visceral adipose tissue. In contrast, serum non-esterified fatty acid levels only rose in SOLF mice. Hypothalamic mRNA levels of NPY decreased and of POMC increased in both UOLF and SOLF mice, but only SOLF mice showed signs of hypothalamic astrogliosis and affectation of central fatty acid metabolism. Exogenous leptin activated STAT3 in the hypothalamus of all groups, but the activation of AKT and mTOR and the decrease in AMPK activation in observed in controls and UOLF mice was not found in SOLF mice. CONCLUSIONS: Diets rich in fatty acids increase body weight and adiposity even if energy intake is not increased, while increased intake of saturated and unsaturated fatty acids differentially modify metabolic parameters that could underlie more long-term comorbidities. Thus, more understanding of how specific nutrients affect metabolism, weight gain, and obesity associated complications is necessary.

Insulin-degrading enzyme ablation in mouse pancreatic alpha cells triggers cell proliferation, hyperplasia and glucagon secretion dysregulation.

AIMS/HYPOTHESIS: Type 2 diabetes is characterised by hyperglucagonaemia and perturbed function of pancreatic glucagon-secreting alpha cells but the molecular mechanisms contributing to these phenotypes are poorly understood. Insulin-degrading enzyme (IDE) is present within all islet cells, mostly in alpha cells, in both mice and humans. Furthermore, IDE can degrade glucagon as well as insulin, suggesting that IDE may play an important role in alpha cell function in vivo. METHODS: We have generated and characterised a novel mouse model with alpha cell-specific deletion of Ide, the A-IDE-KO mouse line. Glucose metabolism and glucagon secretion in vivo was characterised; isolated islets were tested for glucagon and insulin secretion; alpha cell mass, alpha cell proliferation and α-synuclein levels were determined in pancreas sections by immunostaining. RESULTS: Targeted deletion of Ide exclusively in alpha cells triggers hyperglucagonaemia and alpha cell hyperplasia, resulting in elevated constitutive glucagon secretion. The hyperglucagonaemia is attributable in part to dysregulation of glucagon secretion, specifically an impaired ability of IDE-deficient alpha cells to suppress glucagon release in the presence of high glucose or insulin. IDE deficiency also leads to α-synuclein aggregation in alpha cells, which may contribute to impaired glucagon secretion via cytoskeletal dysfunction. We showed further that IDE deficiency triggers impairments in cilia formation, inducing alpha cell hyperplasia and possibly also contributing to dysregulated glucagon secretion and hyperglucagonaemia. CONCLUSIONS/INTERPRETATION: We propose that loss of IDE function in alpha cells contributes to hyperglucagonaemia in type 2 diabetes.

Butyric Acid Precursor Tributyrin Modulates Hippocampal Synaptic Plasticity and Prevents Spatial Memory Deficits: Role of PPARγ and AMPK.

BACKGROUND: Short chain fatty acids (SCFA), such as butyric acid (BA), derived from the intestinal fermentation of dietary fiber and contained in dairy products, are gaining interest in relation to their possible beneficial effects on neuropsychological disorders. METHODS: C57BL/6J male mice were used to investigate the effect of tributyrin (TB), a prodrug of BA, on hippocampus (HIP)-dependent spatial memory, HIP synaptic transmission and plasticity mechanisms, and the expression of genes and proteins relevant to HIP glutamatergic transmission. RESULTS: Ex vivo studies, carried out in HIP slices, revealed that TB can transform early-LTP into late-LTP (l-LTP) and to rescue LTP-inhibition induced by scopolamine. The facilitation of l-LTP induced by TB was blocked both by GW9662 (a PPARγ antagonist) and C-Compound (an AMPK inhibitor), suggesting the involvement of both PPARγ and AMPK on TB effects. Moreover, 48-hour intake of a diet containing 1% TB prevented, in adolescent but not in adult mice, scopolamine-induced impairment of HIP-dependent spatial memory. In the adolescent HIP, TB upregulated gene expression levels of Pparg, leptin, and adiponectin receptors, and that of the glutamate receptor subunits AMPA-2, NMDA-1, NMDA-2A, and NMDA-2B. CONCLUSIONS: Our study shows that TB has a positive influence on LTP and HIP-dependent spatial memory, which suggests that BA may have beneficial effects on memory.

Success, safety, and usefulness of right colon retroflexion for the detection of additional colonic lesions not visualized with standard frontal view.

BACKGROUND: Missed adenomas are the main concern for endoscopists. Right colon retroflexion (RCR) seems to increase the adenoma detection rate (ADR), but important variation in success and usefulness of this maneuver has been reported in the literature AIMS: Primary objective: to assess additional adenoma detection rate (AADR) detected during the RCR attempt. Secondary objectives: to assess success rates of RCR, variables associated with it, and safety of RCR. METHODS: This is a prospective, unicentric, non-randomized study. Consecutive colonoscopies done by six endoscopists (3 of them with < 3 years of experience and 3 with > 3 years) from March to May 2017 were included. Olympus colonoscopes were used (CF-H190, CF-H180) Demographic, clinical, and endoscopic variables were collected. RESULTS: 463 colonoscopies were included. RCR success rate was 93.1% (431/463 colonoscopies). Forty additional lesions were visualized during RCR in 34/463 colonoscopies (7.3%). Additional adenomas were detected in 31/463 colonoscopies (6.7%; OR 0.07). HISTOLOGY: low-grade dysplasia adenomas in 29/40 (72.5%) lesions; 3/40 (7.5%), adenomas with high-grade dysplasia; and 7/40 (17.5%) sessile serrated lesions. Additional adenoma detection contributed to modify the colonoscopy surveillance interval in 25 patients (5.4% of the cohort). Variables associated with RCR success in multivariate analysis were no previous abdominal surgery, length of colonoscope insertion in cecum < 80 cm, and use of Olympus 190 series colonoscopes. No differences between endoscopists' experience were found. RCR was a safe maneuver, with no adverse events in our study. CONCLUSIONS: RCR is a feasible and safe maneuver that can increase ADR, so its routine inclusion in colonoscopy practice should be considered.

Targeting Insulin-Degrading Enzyme in Insulin Clearance.

Hepatic insulin clearance, a physiological process that in response to nutritional cues clears ~50-80% of circulating insulin, is emerging as an important factor in our understanding of the pathogenesis of type 2 diabetes mellitus (T2DM). Insulin-degrading enzyme (IDE) is a highly conserved Zn2+-metalloprotease that degrades insulin and several other intermediate-size peptides. Both, insulin clearance and IDE activity are reduced in diabetic patients, albeit the cause-effect relationship in humans remains unproven. Because historically IDE has been proposed as the main enzyme involved in insulin degradation, efforts in the development of IDE inhibitors as therapeutics in diabetic patients has attracted attention during the last decades. In this review, we retrace the path from Mirsky's seminal discovery of IDE to the present, highlighting the pros and cons of the development of IDE inhibitors as a pharmacological approach to treating diabetic patients.

Pancreatic ß-cell-specific deletion of insulin-degrading enzyme leads to dysregulated insulin secretion and ß-cell functional immaturity.

Inhibition of insulin-degrading enzyme (IDE) has been proposed as a possible therapeutic target for type 2 diabetes treatment. However, many aspects of IDE's role in glucose homeostasis need to be clarified. In light of this, new preclinical models are required to elucidate the specific role of this protease in the main tissues related to insulin handling. To address this, here we generated a novel line of mice with selective deletion of the Ide gene within pancreatic beta-cells, B-IDE-KO mice, which have been characterized in terms of multiple metabolic end points, including blood glucose, plasma C-peptide, and intraperitoneal glucose tolerance tests. In addition, glucose-stimulated insulin secretion was quantified in isolated pancreatic islets and beta-cell differentiation markers and insulin secretion machinery were characterized by RT-PCR. Additionally, IDE was genetically and pharmacologically inhibited in INS-1E cells and rodent and human islets, and insulin secretion was assessed. Our results show that, in vivo, life-long deletion of IDE from beta-cells results in increased plasma C-peptide levels. Corroborating these findings, isolated islets from B-IDE-KO mice showed constitutive insulin secretion, a hallmark of beta-cell functional immaturity. Unexpectedly, we found 60% increase in Glut1 (a high-affinity/low-Km glucose transporter), suggesting increased glucose transport into the beta-cell at low glucose levels, which may be related to constitutive insulin secretion. In parallel, IDE inhibition in INS-1E and islet cells resulted in impaired insulin secretion after glucose challenge. We conclude that IDE is required for glucose-stimulated insulin secretion. When IDE is inhibited, insulin secretion machinery is perturbed, causing either inhibition of insulin release at high glucose concentrations or constitutive secretion.

Usefulness of fully covered self-expandable biliary metal stents for the treatment of post-sphyncterotomy ERCP bleeding.

BACKGROUND: post-sphyncterotomy endoscopic retrograde cholangiopancreatography (ERCP) bleeding is an adverse event with an estimated incidence rate of 1.34%. There is no established consensus about how to treat this particular type of gastrointestinal bleed. Placement of fully covered self-expandable biliary metal stents (FCSEBMS) has been evaluated as an alternative treatment with positive outcomes and a low complication rate. AIM: to report the results of a cohort of patients with post-sphyncterotomy bleeding treated in a tertiary care referral hospital with FCSEBMS. METHODS: a retrospective cases series study was performed including all post-ERCP bleeds treated with FCSEBMS (immediate or delayed) from January 2015 to June 2017. Clinical data, laboratory results and endoscopic reports were collected in order to evaluate the rebleeding rate after endoscopic treatment. Two different scenarios were considered: a) prophylactic stent placement after effective endoscopic treatment; and b) stents placed for the treatment of an active postsphyncterotomy bleed, refractory to standard endoscopic therapy. RESULTS: twenty-two patients (14 male, eight women) diagnosed with postsphyncterotomy bleeding were treated with FCSEBMS placement. The stents were placed prophylactically in 15 patients, while the stents were placed as a treatment for a refractory bleed in seven patients. No differences were found between both groups except for a higher anticoagulation rate in the treatment group. Clinical success was achieved in all but one patient, with no complications in relation to stent placement. Distal migration was described in two of the 22 patients included in the study. CONCLUSIONS: temporary placement of FCSEBMS seems to be a technically feasible treatment option for post-ERCP bleeding with a high clinical success rate. The complication rate was low, although randomized studies are needed.

Usefulness of Non-magnifying Narrow Band Imaging in EVIS EXERA III Video Systems and High-Definition Endoscopes to Diagnose Dysplasia in Barrett's Esophagus Using the Barrett International NBI Group (BING) Classification.

BACKGROUND: Narrow band imaging (NBI) allows identification of abnormal areas of Barrett's esophagus (BE) and could facilitate targeted biopsies. AIMS: We evaluated the diagnostic accuracy for dysplasia prediction using non-magnifying NBI in Evis Exera III processors and high-definition endoscopes using the Barrett International NBI Group (BING) classification, as well as inter/intraobserver agreement for dysplasia prediction and mucosal/vascular patterns. METHODS: Eight observers (4 staff endoscopists and 4 trainee endoscopists) evaluated 100 images selected from an anonymized bank of 470 photographs using the BING classification. Observers were to assign their individual assessment of the mucosal and vascular pattern, and prediction for dysplasia. Accuracy for dysplasia prediction and intra/interobserver agreement was calculated. RESULTS: Dysplasia prediction had an accuracy of 81.1%, sensitivity of 48.4%, and a specificity of 91%. Positive predictive value and negative predictive value (NPV) were 61.4 and 85.5%, respectively. Dysplasia prediction done with a high degree of confidence (vs. low degree of confidence) had better diagnostic accuracy (85.8 vs. 70.7%). Interobserver concordance for dysplasia was weak: Κ = 0.40. Agreement for mucosal and vascular patterns was 0.39 and 0.30, respectively. Intraobserver concordance (assessed 6 months after initial test) for mucosal pattern, vascular pattern, and dysplasia prediction was moderate: Κ = 0.56, Κ = 0.47 and Κ = 0.60, respectively. CONCLUSIONS: Our results showed that NBI had a significant accuracy in BE assessment for dysplasia prediction, high specificity (>90%), and NPV (>85%), with suboptimal sensitivity. NBI could be a useful additional tool for BE inspection and targeted biopsies, but cannot avoid the need for biopsies following the Seattle protocol.

Endoscopically placed stents: a useful alternative for the management of refractory benign cervical esophageal stenosis.

INTRODUCTION: Benign esophageal strictures are relatively frequent and can severely affect the quality of life of a patient. Stenting has been proposed for the treatment of refractory cases. Lesions affecting the cervical esophagus are more difficult to treat, and the placement of stents in this location has traditionally been restricted due to potential adverse events. The aim of this study was to describe the efficacy and safety of endoscopic stenting in the management of refractory benign cervical esophageal strictures (RBCES) in a single-center cohort study. METHODS: We analyzed 12 patients with RBCES (Kochman's criteria) and severe dysphagia. We recorded previous endoscopic treatments, stricture characteristics and demographic data. The two types of stents used were fully covered self-expandable metallic stents (FCSEMS) and uncovered biodegradable stents (BDS). FCSEMS were removed eight weeks after placement, and BDS were followed-up until degradation. We assessed technical and clinical success, rate of stricture recurrence and adverse events. RESULTS: The mean age of participants was 64 years (range 30-85). A total of 23 stents (13 FCSEMS and 10 BDS) were placed in 12 patients (median 1.92, range 1-4). The technical success rate was 96% (22/23 stents). Eight patients (66.6%) maintained adequate oral intake at the end of follow-up (median 33.3 months, range 3-84 months). Migration was recorded in 7/23 stents (30.4%) and epithelial hyperplasia in 4/23 stents (17.4%). No severe adverse events were noted. All patients complained of minor cervical pain after placement that was well controlled with mild analgesia. CONCLUSIONS: Endoscopic stent therapy seems to be effective and safe in the management of RBCES.

Therapeutic impact of colon capsule endoscopy with PillCam™ COLON 2 after incomplete standard colonoscopy: a Spanish multicenter study.

INTRODUCTION: Colon capsule endoscopy (CCE) is an alternative approach for the examination of the colon in patients who refuse colonoscopy or after incomplete colonoscopy (IC). We conducted a study to determine the frequency of complete colonoscopy after IC, the diagnostic yield of CCE, the therapeutic impact of lesions found in CCE, the level of colon cleanliness and the safety of the procedure. METHODS: We performed a prospective, multicenter study involving ten Spanish hospitals. Consecutive outpatients aged ≥ 18 years with previous IC were invited to participate. The latest version of the CCE device, PillCam™ COLON 2 (CCE-2), was administered to all patients according to the protocol. RESULTS: The study population comprised 96 patients. The most frequent cause of IC was the inability to move past a loop using standard maneuvers (75/96 patients, 78%). Complete visualization of the colon was obtained with CCE-2 in 69 patients (71.9%). Of the 27 patients in whom the CCE-2 did not reach the hemorrhoidal plexus, it passed the colonic segment explored with the previous colonoscopy in 20 cases; therefore, it could be inferred that a combined approach (CCE-2 plus colonoscopy) enabled complete visualization of the colonic mucosa in 92.7% of patients. CCE-2 revealed new lesions in 58 patients (60.4%). Polyps were the most frequent finding (41 patients; 42.7% of the total number of patients). In 43 of the 58 patients (44.8% of the total number of patients), the new lesions observed led to modification of therapy, which included a new colonoscopy for polyp resection or surgery in patients with colonic neoplasm. CONCLUSIONS: CCE-2 is a suitable diagnostic procedure that can lead to more frequent diagnosis of significant colonic lesions after IC.

The emotional homunculus: ERP evidence for independent somatosensory responses during facial emotional processing.

Current models of face perception propose that initial visual processing is followed by activation of nonvisual somatosensory areas that contributes to emotion recognition. To test whether there is a pure and independent involvement of somatosensory cortex (SCx) during face processing over and above visual responses, we directly measured participants' somatosensory-evoked activity by tactually probing (105 ms postvisual facial stimuli) the state of SCx during an emotion discrimination task while controlling for visual effects. Discrimination of emotional versus neutral expressions enhanced early somatosensory-evoked activity between 40 and 80 ms after stimulus onset, suggesting visual emotion processing in SCx. This effect was source localized within primary, secondary, and associative somatosensory cortex. Emotional face processing influenced somatosensory responses to both face (congruent body part) and finger (control site) tactile stimulation, suggesting a general process that includes nonfacial cortical representations. Gender discrimination of the same facial expressions did not modulate somatosensory-evoked activity. We provide novel evidence that SCx activation is not a byproduct of visual processing but is independently shaped by face emotion processing.

Nutrient regulation of glucagon secretion: involvement in metabolism and diabetes.

Glucose homeostasis is precisely regulated by glucagon and insulin, which are released by pancreatic α- and ß-cells, respectively. While ß-cells have been the focus of intense research, less is known about α-cell function and the actions of glucagon. In recent years, the study of this endocrine cell type has experienced a renewed drive. The present review contains a summary of established concepts as well as new information about the regulation of α-cells by glucose, amino acids, fatty acids and other nutrients, focusing especially on glucagon release, glucagon synthesis and α-cell survival. We have also discussed the role of glucagon in glucose homeostasis and in energy and lipid metabolism as well as its potential as a modulator of food intake and body weight. In addition to the well-established action on the liver, we discuss the effects of glucagon in other organs, where the glucagon receptor is expressed. These tissues include the heart, kidneys, adipose tissue, brain, small intestine and the gustatory epithelium. Alterations in α-cell function and abnormal glucagon concentrations are present in diabetes and are thought to aggravate the hyperglycaemic state of diabetic patients. In this respect, several experimental approaches in diabetic models have shown important beneficial results in improving hyperglycaemia after the modulation of glucagon secretion or action. Moreover, glucagon receptor agonism has also been used as a therapeutic strategy to treat obesity.

Atrial functional and geometrical remodeling in highly trained male athletes: for better or worse?

PURPOSE: Highly trained athletes have an increased risk of atrial arrhythmias. Atrial geometrical and functional remodeling may be the underlying substrate. We analyze and relate atrial size, deformation and performance in professional handball players compared with non-sportive subjects. METHODS: 24 Professional handball players and 20 non-sportive males were compared. All subjects underwent an echocardiographic study with evaluation of left (LA), right atrial (RA) dimensions and deformation by strain (Sa) and strain rate (SRa). Atrial performance was assessed from the atrial stroke volume (SV). With computational geometrical models, we studied the relation between atrial volumes, strains and SV and compared atrial working conditions. We estimated the functional reserve and a resulting average wall stress. RESULTS: LA and RA volumes were larger in athletes than in controls (35.2 ± 8.8 vs. 24.8 ± 4.3 ml/m(2), p < 0.01 and 29.0 ± 8.4 vs. 19.0 ± 5.1 ml/m(2), p < 0.01 respectively). LASa and RASa during active atrial contraction were decreased in athletes (-12.2 ± 2.0 vs. -14.5 ± 2.1%, p < 0.01 and -12.1 ± 1.8 vs. -14.2 ± 1.5%, p < 0.01 respectively). LASV was similar between groups (6.6 ± 1.4 vs. 7.3 ± 1.1 ml, p = 0.19) and RASV was lower in athletes (6.2 ± 1.3 vs. 7.2 ± 1.1 ml, p < 0.01). Computational models showed that this different operational mode potentially increases performance reserve, but at the cost of higher atrial wall stress. CONCLUSION: A proportion of athletes with enlarged LA and RA showed different atrial contractile performance, likely resulting in atria working at higher wall stress.

Recognition of dance-like actions: memory for static posture or dynamic movement?

Dance-like actions are complex visual stimuli involving multiple changes in body posture across time and space. Visual perception research has demonstrated a difference between the processing of dynamic body movement and the processing of static body posture. Yet, it is unclear whether this processing dissociation continues during the retention of body movement and body form in visual working memory (VWM). When observing a dance-like action, it is likely that static snapshot images of body posture will be retained alongside dynamic images of the complete motion. Therefore, we hypothesized that, as in perception, posture and movement would differ in VWM. Additionally, if body posture and body movement are separable in VWM, as form- and motion-based items, respectively, then differential interference from intervening form and motion tasks should occur during recognition. In two experiments, we examined these hypotheses. In Experiment 1, the recognition of postures and movements was tested in conditions in which the formats of the study and test stimuli matched (movement-study to movement-test, posture-study to posture-test) or mismatched (movement-study to posture-test, posture-study to movement-test). In Experiment 2, the recognition of postures and movements was compared after intervening form and motion tasks. These results indicated that (1) the recognition of body movement based only on posture is possible, but it is significantly poorer than recognition based on the entire movement stimulus, and (2) form-based interference does not impair memory for movements, although motion-based interference does. We concluded that, whereas static posture information is encoded during the observation of dance-like actions, body movement and body posture differ in VWM.