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25 result(s) for "Sandoval, Alejandro F"
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Sleeve gastrectomy facilitates weight loss and permits cardiac transplantation in patients with severe obesity and a left ventricular assist device (LVAD)
IntroductionPatients suffering from advanced heart failure may undergo left ventricular assist device (LVAD) placement as a bridge to cardiac transplantation. However, those with a BMI above 35 kg/m2 are generally not considered eligible for transplant due to their elevated cardiac risk. We review our experience with bariatric surgery in this high-risk population to assess its safety and efficacy in reducing BMI to permit cardiac transplantation.MethodsWe retrospectively reviewed all patients on durable LVAD support who underwent sleeve gastrectomy (SG) at Mount Sinai Hospital between August 2018 and December 2022. Electronic medical records were reviewed to analyze patient demographics, surgical details, and outcomes regarding weight loss and heart transplantation.ResultsWe identified twelve LVAD patients who underwent SG. Three were performed laparoscopically and 9 via robotic approach. Four patients (33.3%) underwent an orthotopic heart transplant (OHTx). Half of these patients were female. For patients who underwent OHTx, mean age at LVAD placement was 41.0 (R30.6–52.2), at SG was 43.9 (R32.7–55.0) and at OHTx was 45.3 years (R33.3–56.8). Mean BMI increased from 38.8 at LVAD placement to 42.5 prior to SG. Mean time from SG to OHTx was 17.9 months (R6-7-27.5) during which BMI decreased to mean 32.8 at the time of OHTx. At most recent follow-up, mean BMI was 31.9. All patients were anticoagulated prior to surgery; one required return to the operating room on post-operative day 1 after SG for bleeding and one was re-admitted on post-operative day 7 for hematochezia treated conservatively.ConclusionSG is a safe and effective operation in patients with severe obesity and heart failure requiring an LVAD. 66.7% of our cohort achieved target BMI < 35 and 33.3% underwent heart transplantation. Longer term follow-up is needed to clarify full bridge-to-transplant rate and long-term survival outcomes.
Mangrove carbon sustains artisanal fish and other estuarine consumers in a major mangrove area of the southern Caribbean Sea
Estuaries are highly productive habitats that support fisheries production. However, the importance of mangrove carbon to estuarine consumers can differ considerably among systems. In this study, we used stable isotopes (δ13C, δ15N) to investigate the importance of mangrove carbon as an energy source to estuarine consumers in the Atrato River Delta, Colombia, an area where fringing mangroves dominate the coastline and where other productive coastal habitats that may otherwise support the food web are absent. Basal resources and consumers were collected from mangrove and nearshore habitats during the rainy season. Results revealed a food web with a maximum length of 4.6 trophic positions. Bayesian mixing models indicated that most consumers used a mixture of basal sources, which suggests intertwined energetic pathways. However, mixing models also indicated that some species relied more heavily on some basal sources than others and revealed trophic pathways (food chains). Mangrove carbon directly supported herbivorous crabs (Sesarmidae) and indirectly supported planktivorous fish (Engraulidae) and piscivorous fish. Mangrove carbon also contributed significantly to the diet of 2 of the most common fish species in the local artisanal fishery: Centropomus undecimalis (mean: 46%; credibility interval [CI]: 1−80%) and C. pectinatus (mean: 33%; CI: 1−78%). Our findings highlight that mangrove carbon can be an important food source in areas without other productive coastal habitats and can play an important role in sustaining the production of fisheries.
Dummy regression to predict dry fiber in Agave lechuguilla Torr. in two large-scale bioclimatic regions in Mexico
Agave lechuguilla Torr., of the family Agavaceae, is distributed from southwestern United States to southern Mexico and is one of the most representative species of arid and semiarid regions. Its fiber is extracted for multiple purposes. The objective of this study was to generate a robust model to predict dry fiber yield ( Dfw ) rapidly, simply, and inexpensively. We used a power model in its linear form and bioclimatic areas as dummy variables. Training, generation (80%) and validation (20%) of the model was performed using machine learning with the package ‘ caret’ of R. Using canonical correlation analysis (CCA), we evaluated the relationship of Dwf to bioclimatic variables. The principal components analysis (PCA) generated two bioclimatic zones, each with different A . lechuguilla productivities. We evaluated 499 individuals in four states of Mexico. The crown diameter ( Cd ) of this species adequately predicts its fiber dry weight (R 2 = 0.6327; p < 0.05). The intercept (β 0 ), slope [ lnCd (β 1 )], zone [( β 2 )] and interaction [ lnCd :Zona ( β 3 )] of the dummy model was statistically significant (p < 0.05), giving origin to an equation for each bioclimatic zone. The CCA indicates a positive correlation between minimum temperature of the coldest month (Bio 6) and Dwf (r = 0.84 and p < 0.05). In conclusion, because of the decrease in Bio 6 of more than 0.5°C by 2050, the species could be vulnerable to climate change, and A . lechuguilla fiber production could be affected gradually in the coming years.
Thermal Imaging to Assess the Health Status in Wildlife Animals under Human Care: Limitations and Perspectives
Promoting animal welfare in wildlife species under human care requires the implementation of techniques for continuously monitoring their health. Infrared thermography is a non-invasive tool that uses the radiation emitted from the skin of animals to assess their thermal state. However, there are no established thermal windows in wildlife species because factors such as the thickness or color of the skin, type/length of coat, or presence of fur can influence the readings taken to obtain objective, sensitive values. Therefore, this review aims to discuss the usefulness and application of the ocular, nasal, thoracic, abdominal, and podal anatomical regions as thermal windows for evaluating zoo animals’ thermal response and health status. A literature search of the Web of Science, Science Direct, and PubMed databases was performed to identify relevant studies that used IRT with wild species as a complementary diagnostic tool. Implementing IRT in zoos or conservation centers could also serve as a method for determining and monitoring optimal habitat designs to meet the needs of specific animals. In addition, we analyze the limitations of using IRT with various wildlife species under human care to understand better the differences among animals and the factors that must be considered when using infrared thermography.
A 500-year tale of co-evolution, adaptation, and virulence:Helicobacter pyloriin the Americas
Helicobacter pyloriis a common component of the human stomach microbiota, possibly dating back to the speciation ofHomo sapiens. A history of pathogen evolution in allopatry has led to the development of genetically distinctH. pylorisubpopulations, associated with different human populations, and more recent admixture amongH. pylorisubpopulations can provide information about human migrations. However, little is known about the degree to which someH. pylorigenes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzedH. pylorigenomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723H. pyloristrains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions fromH. pyloripopulations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel AmericanH. pylorisubpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.
Feeding habits and trophic level of the smooth hammerhead shark, Sphyrna zygaena (Carcharhiniformes: Sphyrnidae), off Ecuador
As apex predators, sharks are known to play an important role in marine food webs. Detailed information on their diet and trophic level is however needed to make clear inferences about their role in the ecosystem. A total of 335 stomachs of smooth hammerhead sharks, Sphyrna zygaena, were obtained from commercial fishing vessels operating in the Ecuadorian Pacific between January and December 2004. A total of 53 prey items were found in the stomachs. According to the Index of Relative Importance (%IRI), cephalopods were the main prey (Dosidicus gigas, Sthenoteuthis oualaniensis, Ancistrocheirus lesueurii and Lolliguncula [Loliolopsis] diomedeae). Sphyrna zygaena was thus confirmed to be a teutophagous species. The estimated trophic level of S. zygaena was between 4.6 and 5.1 (mean ± SD: 4.7 ± 0.16; males: 4.7; females: 4.8). Levin's index (BA) was low (overall: 0.07; males: 0.08; females: 0.09), indicating a narrow trophic niche. We found that sharks <150 cm in total length consumed prey of coastal origin, whereas sharks ≥150 cm foraged in oceanic waters and near the continental shelf. The analyses indicate that S. zygaena is a specialized predator consuming mainly squids.
Regulation of Nitrate Uptake by the Seagrass Zostera marina During Upwelling
Prolonged nitrogen (N) fertilization can impact seagrass survival and productivity; however, the effects of N enrichment pulses (e.g., upwelling or sediment resuspension) remain poorly understood. This study examined the effects of short-term (1 h) pulsing of nitrate ( N O 3 − ) enrichment, simulating an upwelling event, on dissolved inorganic carbon (DIC) and N O 3 − uptake capacities, critical in controlling eelgrass productivity. Zostera marina dominates submerged vegetation in coastal lagoons influenced by upwelling in the California Current system. Laboratory incubations were conducted in winter (non-upwelling) and spring (upwelling) with shoots collected from San Quintín Bay meadows, Baja California, Mexico, differentially exposed to upwelled N O 3 − . Results suggest that N O 3 − enrichment stimulated DIC and N O 3 − uptake in winter, reflecting the close relationship between carbon metabolism and N O 3 − assimilation. Eelgrass shoots showed reduced N O 3 − incorporation in spring; neither N O 3 − uptake nor photosynthesis increased when exposed to high N O 3 − . Saturation of spring shoots at lower ambient N O 3 − concentrations may be interpreted as a physiological strategy to restrict metabolically costly N O 3 − incorporation during upwelling; this regulation of N O 3 − uptake strongly contrasts to the apparently full exploitation of this nutrient by seaweeds also dominant within the bay, as indicated in previous works. Despite their reduced N O 3 − uptake, eelgrass meadows near the bay mouth acquire N O 3 − at rates up to 4.2 mmol N m⁻² day⁻¹. This represents nontrivial water column N O 3 − removal compared to the estimated oceanic N O 3 − supply (~ 7.1 mmol m⁻² day⁻¹) during upwelling, highlighting the importance of Z. marina beds in controlling the lagoonal N-budget.
Pyridostigmine reduces mortality of patients with severe SARS-CoV-2 infection: A phase 2/3 randomized controlled trial
: Background: Respiratory failure in severe coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Acetylcholine (ACh) reduces systemic inflammation in experimental bacterial and viral infections. Pyridostigmine increases the half-life of endogenous ACh, potentially reducing systemic inflammation. We aimed to determine if pyridostigmine decreases a composite outcome of invasive mechanical ventilation (IMV) and death in adult patients with severe COVID-19. Methods: We performed a double-blinded, placebo-controlled, phase 2/3 randomized controlled trial of oral pyridostigmine (60 mg/day) or placebo as add-on therapy in adult patients admitted due to confirmed severe COVID-19 not requiring IMV at enrollment. The primary outcome was a composite of IMV or death by day 28. Secondary outcomes included reduction of inflammatory markers and circulating cytokines, and 90-day mortality. Adverse events (AEs) related to study treatment were documented and described. Results: We recruited 188 participants (94 per group); 112 (59.6%) were men; the median (IQR) age was 52 (44–64) years. The study was terminated early due to a significant reduction in the primary outcome in the treatment arm and increased difficulty with recruitment. The primary outcome occurred in 22 (23.4%) participants in the placebo group vs. 11 (11.7%) in the pyridostigmine group (hazard ratio, 0.47, 95% confidence interval 0.24–0.9; P  = 0.03). This effect was driven by a reduction in mortality (19 vs. 8 deaths, respectively). Conclusion: Our data indicate that adding pyridostigmine to standard care reduces mortality among patients hospitalized for severe COVID-19.
A 500-year tale of co-evolution, adaptation, and virulence: Helicobacter pylori in the Americas
Helicobacter pylori is a common component of the human stomach microbiota, possibly dating back to the speciation of Homo sapiens . A history of pathogen evolution in allopatry has led to the development of genetically distinct H. pylori subpopulations, associated with different human populations, and more recent admixture among H. pylori subpopulations can provide information about human migrations. However, little is known about the degree to which some H. pylori genes are conserved in the face of admixture, potentially indicating host adaptation, or how virulence genes spread among different populations. We analyzed H. pylori genomes from 14 countries in the Americas, strains from the Iberian Peninsula, and public genomes from Europe, Africa, and Asia, to investigate how admixture varies across different regions and gene families. Whole-genome analyses of 723 H. pylori strains from around the world showed evidence of frequent admixture in the American strains with a complex mosaic of contributions from H. pylori populations originating in the Americas as well as other continents. Despite the complex admixture, distinctive genomic fingerprints were identified for each region, revealing novel American H. pylori subpopulations. A pan-genome Fst analysis showed that variation in virulence genes had the strongest fixation in America, compared with non-American populations, and that much of the variation constituted non-synonymous substitutions in functional domains. Network analyses suggest that these virulence genes have followed unique evolutionary paths in the American populations, spreading into different genetic backgrounds, potentially contributing to the high risk of gastric cancer in the region.
Electronic paper from facile, two-step deposition of CuS
A method is proposed to impregnate regular cellulosic paper with semi-conductive particles of copper sulfide. The method consists of a simple two-step procedure: first, metal (Cu) ions in solution are applied to the paper, and second, the aqueous application of a source of sulfide ions, which leads to the spontaneous formation of metal sulfides in the pores of the paper matrix, as evidenced by a color change. This methodology is easy to implement and involves very low-cost and easily available chemical agents, leading to the production of low-price semiconductor devices. In this work, the microscopic morphology and crystalline structures of films were studied, as well as their optical and electrical properties. The proposed sample preparation route could potentially be implemented in further research using different metals in order to obtain tunable physical properties, such as band gap, conductivity and conductivity carrier types.