Immunocompromised Children With Acute Respiratory Distress Syndrome Possess a Distinct Circulating Inflammatory Profile.

Immunocompromised status, with and without stem cell transplant, confers a worse prognosis in pediatric acute respiratory distress syndrome. An improved understanding of the biochemical profile of immunocompromised children with acute respiratory distress syndrome would inform whether specific pathways are targetable, or merely bystanders, in order to improve outcomes in this high-risk subgroup. OBJECTIVES: We aimed to identify a biomarker profile of immunocompromised children, with and without stem cell transplant, independent of illness severity. DESIGN SETTINGS AND PARTICIPANTS: This was a secondary analysis of a prospective cohort study of intubated children with Berlin-defined acute respiratory distress syndrome with existing biomarker measurements conducted in a large academic PICU between 2014 and 2019. MAIN OUTCOMES AND MEASURES: Biomarker levels were compared between immunocompetent and immunocompromised children, with and without stem cell transplant, both prior to and after adjusting for severity of illness. RESULTS: In 333 children with acute respiratory distress syndrome, 84 were immunocompromised, of whom 39 had a stem cell transplant. Circulating neutrophil levels were strongly correlated with biomarkers, with 14 of 18 measured proteins differentially expressed in patients with versus without neutropenia. In order to identify biomarker levels independent of severity of illness, acute respiratory distress syndrome etiology, and neutrophil levels, we computed predicted (log-transformed) biomarker levels after adjusting for confounders using linear regression and then compared these severity-adjusted levels between immunocompetent and immunocompromised (with and without stem cell transplant) subjects using analyses of variance and post hoc Bonferroni. After multivariable adjustment, 11 biomarkers were higher in immunocompromised subjects without stem cell transplant, relative to immunocompetent, implicating endotheliopathy (angiopoietin-2), tissue damage (procollagen type III N-terminal peptide), and innate immunity. A single biomarker, C-C motif chemokine ligand 22, was lower in immunocompromised subjects with and without stem cell transplant. CONCLUSIONS AND RELEVANCE: Immunocompromised children with acute respiratory distress syndrome were characterized by elevations in pro-inflammatory and endothelial damage biomarkers. Our study provides insight into mechanisms underlying the molecular heterogeneity of this population and potentially identifies targetable pathways to mitigate their increased mortality risk.

Organocatalytic Enantioselective Sulfa-Michael Additions to α,ß-Unsaturated Diazoketones.

Enantioselective sulfa-Michael additions to α,ß unsaturated diazocarbonyl compounds have been developed. Quinine-derived squaramide was found to be the best catalyst to promote C-S bond formation in a highly stereoselective fashion for alkyl and aryl thiols. The easy-to-follow protocol allowed the preparation of 22 examples in enantiomeric ratios up to 97:3 and reaction yields up to 94%. The mechanism and origins of enantioselectivity were determined through density functional theory (DFT) calculations.

Enantioselective S-H Insertion Reactions of α-Carbonyl Sulfoxonium Ylides.

The first example of enantioselective S-H insertion reactions of sulfoxonium ylides is reported. Under the influence of thiourea catalysis, excellent levels of enantiocontrol (up to 95 % ee) and yields (up to 97 %) are achieved for 31 examples in S-H insertion reactions of aryl thiols and α-carbonyl sulfoxonium ylides.

Painted black: Iguana melanoderma (Reptilia, Squamata, Iguanidae) a new melanistic endemic species from Saba and Montserrat islands (Lesser Antilles).

The Lesser Antilles, in the Eastern Caribbean, is inhabited by three Iguana species: the Lesser Antillean iguanaIguana delicatissima, which is endemic to the northernmost islands of the Lesser Antilles, the introduced common iguana from South America, Iguana iguana iguana, represented also by the two newly described endemic subspecies Iguana iguana sanctaluciae from Saint Lucia and Iguana iguana insularis from Saint Vincent and the Grenadines, and Grenada, and the introduced Iguana rhinolopha from Central America. Drawing on both morphological and genetic data, this paper describes the Iguana populations from Saba and Montserrat as a new species, Iguana melanoderma. This species is recognized on the basis of the following combination of characteristics: private microsatellite alleles, unique mitochondrial ND4 haplotypes, a distinctive black spot between the eye and tympanum, a dorsal carpet pattern on juveniles and young adults, a darkening of body coloration with aging (except for the anterior part of the snout), a black dewlap, pink on the jowl, the high number of large tubercular nape scales, fewer than ten medium sized-triangular dewlap spikes, high dorsal spikes, and lack of horns on the snout. This new melanistic taxon is threatened by unsustainable harvesting (including for the pet trade) and both competition and hybridization from escaped or released invasive alien iguanas (I. iguana iguana and I. rhinolopha) from South and Central America, respectively. The authors call for action to conserve Iguana melanoderma in Saba and Montserrat and for further research to investigate its relationship to other melanistic iguanas from the Virgin Islands and coastal islands of Venezuela.

A Review on the Study of Cyanotoxins in Paleolimnological Research: Current Knowledge and Future Needs.

Cyanobacterial metabolites are increasingly studied, in regards to their biosynthesis, ecological role, toxicity, and potential biomedical applications. However, the history of cyanotoxins prior to the last few decades is virtually unknown. Only a few paleolimnological studies have been undertaken to date, and these have focused exclusively on microcystins and cylindrospermopsins, both successfully identified in lake sediments up to 200 and 4700 years old, respectively. In this paper, we review direct extraction, quantification, and application of cyanotoxins in sediment cores, and put forward future research prospects in this field. Cyanobacterial toxin research is also compared to other paleo-cyanobacteria tools, such as sedimentary pigments, akinetes, and ancient DNA isolation, to identify the role of each tool in reproducing the history of cyanobacteria. Such investigations may also be beneficial for further elucidation of the biological role of cyanotoxins, particularly if coupled with analyses of other abiotic and biotic sedimentary features. In addition, we identify current limitations as well as future directions for applications in the field of paleolimnological studies on cyanotoxins.

A story of nasal horns: two new subspecies of Iguana Laurenti, 1768 (Squamata, Iguanidae) in Saint Lucia, St Vincent amp; the Grenadines, and Grenada (southern Lesser Antilles).

The Lesser Antilles, in the Eastern Caribbean, were long considered to have only two species in the genus Iguana Laurenti 1768: the Lesser Antillean iguana Iguana delicatissima, which is endemic to parts of the Lesser Antilles, and the Common green iguana Iguana iguana, which also occurs throughout Central and South America. No subspecies are currently recognised. However, herpetologists and reptile collectors have pointed out strong physical differences between some of the island populations of Iguana iguana and those from the continent. Drawing on both morphological and genetic data, this paper describes two subspecies of the Common green iguana Iguana iguana from the southern Lesser Antilles, specifically the countries of Saint Lucia Iguana iguana sanctaluciae and Iguana iguana insularis from St Vincent the Grenadines, and Grenada. The form on the island of Saint Vincent has not been identified. The new subspecies are described based on the following unique combination of characters: Presence of high median and medium to small lateral horns on the snout; Small subtympanic plate not exceeding 20% of the eardrum size; Two or three scales of decreasing size anterior to the subtympanic plate; Fewer than ten small to medium triangular gular spikes; Medium sized dewlap; Low number of small to medium dispersed nuchal tubercles; Dark brown iris, with the white of the eye visible; Oval, prominent nostril; Short and relatively flat head; High dorsal spines; No swelling of the jowls in reproductively active males.                Iguana iguana sanctaluciae has in adults vertical black stripes on body and tail and a black dewlap whereas Iguana iguana insularis is pale grey or creamy white in adults.                Both subspecies are globally threatened by unsustainable hunting (including the pet trade) and by invasive alien species,     including hybridization from invasive iguanas from South and Central America (I. iguana iguana and I. rhinolopha, considered here as full species) that have become established in all three countries. The authors call for stronger measures to conserve the remaining purebred Iguana i. insularis and Iguana i. sanctaluciae ssp. nov. throughout their ranges and for further research to identify other cryptic species and subspecies of Iguana in the Lesser Antilles.

Improving grain yield, stress resilience and quality of bread wheat using large-scale genomics.

Bread wheat improvement using genomic tools is essential for accelerating trait genetic gains. Here we report the genomic predictabilities of 35 key traits and demonstrate the potential of genomic selection for wheat end-use quality. We also performed a large genome-wide association study that identified several significant marker-trait associations for 50 traits evaluated in South Asia, Africa and the Americas. Furthermore, we built a reference wheat genotype-phenotype map, explored allele frequency dynamics over time and fingerprinted 44,624 wheat lines for trait-associated markers, generating over 7.6 million data points, which together will provide a valuable resource to the wheat community for enhancing productivity and stress resilience.

Mechanistic Insights into a Chiral Phosphoric Acid-Catalyzed Asymmetric Pinacol Rearrangement.

The first catalytic enantioselective pinacol rearrangement was reported by Antilla and co-workers in 2010. The reaction was catalyzed by a chiral phosphoric acid and resulted in high levels of enantioselectivity (up to 96% ee). The present study uses density functional theory to investigate the mechanism and origins of stereoselectivity of this important reaction and to explain the difference in selectivity between different catalysts. An OH···O hydrogen bond between the intermediate indolyl alcohol and the phosphate group from the catalyst together with a CH···O hydrogen bond between the indole and the phosphate group were observed in the preferred activation mode for the stereodetermining [1,2]-aryl shift. A stronger CH···O interaction in the major transition state was found to contribute to the high levels of enantioselectivity. A more bulky catalyst (TRIP) was found to impede the formation of the key CH···O interaction, leading to lower levels of enantioselectivity.

Ecosystem heterogeneity and diversity mitigate Amazon forest resilience to frequent extreme droughts.

The impact of increases in drought frequency on the Amazon forest's composition, structure and functioning remain uncertain. We used a process- and individual-based ecosystem model (ED2) to quantify the forest's vulnerability to increased drought recurrence. We generated meteorologically realistic, drier-than-observed rainfall scenarios for two Amazon forest sites, Paracou (wetter) and Tapajós (drier), to evaluate the impacts of more frequent droughts on forest biomass, structure and composition. The wet site was insensitive to the tested scenarios, whereas at the dry site biomass declined when average rainfall reduction exceeded 15%, due to high mortality of large-sized evergreen trees. Biomass losses persisted when year-long drought recurrence was shorter than 2-7 yr, depending upon soil texture and leaf phenology. From the site-level scenario results, we developed regionally applicable metrics to quantify the Amazon forest's climatological proximity to rainfall regimes likely to cause biomass loss > 20% in 50 yr according to ED2 predictions. Nearly 25% (1.8 million km2 ) of the Amazon forests could experience frequent droughts and biomass loss if mean annual rainfall or interannual variability changed by 2σ. At least 10% of the high-emission climate projections (CMIP5/RCP8.5 models) predict critically dry regimes over 25% of the Amazon forest area by 2100.

Microbialite genetic diversity and composition relate to environmental variables.

Microbialites have played an important role in the early history of life on Earth. Their fossilized forms represent the oldest evidence of life on our planet dating back to 3500 Ma. Extant microbialites have been suggested to be highly productive and diverse communities with an evident role in the cycling of major elements, and in contributing to carbonate precipitation. Although their ecological and evolutionary importance has been recognized, the study of their genetic diversity is yet scanty. The main goal of this study was to analyse microbial genetic diversity of microbialites living in different types of environments throughout Mexico, including desert ponds, coastal lagoons and a crater-lake. We followed a pyrosequencing approach of hypervariable regions of the 16S rRNA gene. Results showed that microbialite communities were very diverse (H' = 6-7) and showed geographic variation in composition, as well as an environmental effect related to pH and conductivity, which together explained 33% of the genetic variation. All microbialites had similar proportions of major bacterial and archaeal phyla.

Cáncer de piel / Cancer of the skin

Profusamente ilustrado con fotografías, este texto es una exposición completa y actual, sobre neoplasias de la piel. Obra exelente. Su índice es: biología de la invasión y metástasis cancerosas cutáneas, epidemiología, posibles precursores de procesos malignos apidérmicos, carcinoma de células basales,escamosas y carcinoma verrugoso, oncogénesis viral en malignidades cutáneas, papulosis bowenoide, epidermodisplasia verruciforme, detección temprana de melanomas malignos: papel del exámen médico y el autoexámen de la piel, nevos displásicos, lesiones precursoras: nevos melanocíticos congénitos, melanoma maligno: correlaciones clinicopatológicas y tratamiento, factores pronóstico que influyen en la supervivencia de personas con melanoma maligno cutáneo, carcinomas de los anexos de la piel, enfermedad de Paget mamaria y extramamaria, lesiones seudosarcomatosas (neoplásicas y no neoplásicas) de la piel y tejidos superficiales, carcinoma de células de Merkel, neoplasias vasculares de la piel y asociadas con el SIDA, linfomas de células T cutáneos, enfermedades genéticas que predisponen a procesos malignos, cánceres metastáticos en la piel, manifestaciones dermatológicas de procesos malignos internos, nevo de grandes células fusiformes o epitelioides(nevo de Spitz), queratoacantoma, seudolinfomas cutáneos, técnicas de biopsia y principios quirúrgicos generales en el tratamiento del cáncer de piel, curetaje y electrodesecación terapéuticos, criocirugía, quimioterapia, cirugía con láser, cirugía plástica reconstructiva, radioterapia, inmunoterapia en el tratamiento de melanomas malignos, comprensión y tratamiento psicológico del paciente, el papel del oftalmólogo, problemas medicolegales en el manejo con pacientes con cáncer cutáneo

Cáncer de piel / Cancer of the skin

Profusamente ilustrado con fotografías, este texto es una exposición completa y actual, sobre neoplasias de la piel. Obra exelente. Su índice es: biología de la invasión y metástasis cancerosas cutáneas, epidemiología, posibles precursores de procesos malignos apidérmicos, carcinoma de células basales,escamosas y carcinoma verrugoso, oncogénesis viral en malignidades cutáneas, papulosis bowenoide, epidermodisplasia verruciforme, detección temprana de melanomas malignos: papel del exámen médico y el autoexámen de la piel, nevos displásicos, lesiones precursoras: nevos melanocíticos congénitos, melanoma maligno: correlaciones clinicopatológicas y tratamiento, factores pronóstico que influyen en la supervivencia de personas con melanoma maligno cutáneo, carcinomas de los anexos de la piel, enfermedad de Paget mamaria y extramamaria, lesiones seudosarcomatosas (neoplásicas y no neoplásicas) de la piel y tejidos superficiales, carcinoma de células de Merkel, neoplasias vasculares de la piel y asociadas con el SIDA, linfomas de células T cutáneos, enfermedades genéticas que predisponen a procesos malignos, cánceres metastáticos en la piel, manifestaciones dermatológicas de procesos malignos internos, nevo de grandes células fusiformes o epitelioides(nevo de Spitz), queratoacantoma, seudolinfomas cutáneos, técnicas de biopsia y principios quirúrgicos generales en el tratamiento del cáncer de piel, curetaje y electrodesecación terapéuticos, criocirugía, quimioterapia, cirugía con láser, cirugía plástica reconstructiva, radioterapia, inmunoterapia en el tratamiento de melanomas malignos, comprensión y tratamiento psicológico del paciente, el papel del oftalmólogo, problemas medicolegales en el manejo con pacientes con cáncer cutáneo