Switchable Cycloadditions of Mesoionic Dipoles: Refreshing up a Regioselective Approach to Two Distinctive Heterocycles.

Mesoionic rings are among the most versatile 1,3-dipoles, as witnessed recently by their incorporation into bio-orthogonal strategies, and capable of affording unconventional heterocycles beyond the expected scope of Huisgen cycloadditions. Herein, we revisit in detail the reactivity of thiazol-3-ium-4-olates with alkynes, leading to thiophene and/or pyrid-2-one derivatives. A structural variation at the parent mesoionic dipole alters sufficiently the steric outcome, thereby favoring the regioselective formation of a single transient cycloadduct, which undergoes chemoselective fragmentation to either five- or six-membered heterocycles. The synthetic protocol benefits largely from microwave (MW) activation, which enhances reaction rates. The mechanism has been interrogated with the aid of density functional theory (DFT) calculations, which sheds light into the origin of the regioselectivity and points to a predictive formulation of reactivity involving competing pathways of mesoionic cycloadditions.

Within-subject biological variation estimates using an indirect data mining strategy. Spanish multicenter pilot study (BiVaBiDa).

OBJECTIVES: The estimates of biological variation (BV) have traditionally been determined using direct methods, which present limitations. In response to this issue, two papers have been published addressing these limitations by employing indirect methods. Here, we present a new procedure, based on indirect methods that analyses data collected within a multicenter pilot study. Using this method, we obtain CVI estimates and calculate confidence intervals (CI), using the EFLM-BVD CVI estimates as gold standard for comparison. METHODS: Data were collected over a 18-month period for 7 measurands, from 3 Spanish hospitals; inclusion criteria: patients 18-75 years with more than two determinations. For each measurand, four different strategies were carried out based on the coefficient of variation ratio (rCoeV) and based on the use of the bootstrap method (OS1, RS2 and RS3). RS2 and RS3 use symmetry reference change value (RCV) to clean database. RESULTS: RS2 and RS3 had the best correlation for the CVI estimates with respect to EFLM-BVD. RS2 used the symmetric RCV value without eliminating outliers, while RS3 combined RCV and outliers. When using the rCoeV and OS1 strategies, an overestimation of the CVI value was obtained. CONCLUSIONS: Our study presents a new strategy for obtaining robust CVI estimates using an indirect method together with the value of symmetric RCV to select the target population. The CVI estimates obtained show a good correlation with those published in the EFLM-BVD database. Furthermore, our strategy can resolve some of the limitations encountered when using direct methods such as calculating confidence intervals.

Outdoor Activity Associated with Higher Self-Reported Emotional Well-Being During COVID-19.

Shifts in activity patterns during the COVID-19 pandemic might have impacted the benefits of outdoor activities for mental health. By leveraging an existing mobile application, we collected self-reported data on daily outdoor activities, emotional well-being, and the influence of COVID-19 on participant's outdoor activity levels during April-July 2020. Individuals reporting outdoor activities, in greenspaces or in their residence, had higher well-being scores and this effect increased with age. Self-reported impacts of COVID-19 on emotional well-being were associated with lower well-being scores. This work suggests that outdoor activities may have improved mental health during the COVID-19 pandemic.

Frequent Alteration of Annexin A9 and A10 in HPV-Negative Head and Neck Squamous Cell Carcinomas: Correlation with the Histopathological Differentiation Grade.

The annexin protein superfamily has been implicated in multiple physiological and pathological processes, including carcinogenesis. Altered expression of various annexins has frequently been observed and linked to the development and progression of various human malignancies. However, information is lacking on the expression and clinical significance of annexin A9 (ANXA9) and A10 (ANXA10) in head and neck squamous cell carcinomas (HNSCC). ANXA9 and ANXA10 expression was evaluated in a large cohort of 372 surgically treated HPV-negative HNSCC patients and correlated with the clinicopathologic parameters and disease outcomes. Down-regulation of ANXA9 expression was found in 42% of HNSCC tissue samples, compared to normal epithelia. ANXA9 expression in tumors was significantly associated with oropharyngeal location and histological differentiation grade (P < 0.001). In marked contrast, ANXA10 expression was absent in normal epithelium, but variably detected in the cytoplasm of cancer cells. Positive ANXA10 expression was found in 64% of tumors, and was significantly associated with differentiation grade (P < 0.001), being also more frequent in oropharyngeal tumors (P = 0.019). These results reveal that the expression of both ANXA9 and ANXA10 is frequently altered in HNSCC and associated to the tumor differentiation grade, suggesting that they could be implicated in the pathogenesis of these cancers.

On the asymmetric autocatalysis of aldol reactions: The case of 4-nitrobenzaldehyde and acetone. A critical appraisal with a focus on theory.

Under neutral conditions, spontaneous mirror symmetry breaking has been occasionally reported for aldol reactions starting from achiral reagents and conditions. Chiral induction might be interpreted in terms of autocatalysis exerted by chiral mono-aldol or bis-aldol products as source of initial enantiomeric excesses, which may account for such experimental observations. We describe here a thorough Density Functional Theory (DFT) study on this complex and otherwise difficult problem, which provides some insights into this phenomenon. The picture adds further rationale to an in-depth analysis by Moyano et al, who showed the isolation and characterization of bis-aldol adducts and their participation in a complex network of reversible steps. However, the lack of enantiodiscrimination (ees vanish rapidly in solution) suggests, according to the present results, a weak association in complexes formed by the catalysts and substrates. The latter would also be consistent with almost flat transition states having similar heights for competitive catalyst-bound transition structures (actually, we were unable to locate them at the level explored). Overall, neither autocatalysis as once conjectured nor mutual inhibition of enantiomers appears to be operating mechanisms. Asymmetric amplification in early stages harnessing unavoidable enantiomeric imbalances in reaction mixtures of chiral products represents a plausible interpretation.

Dysregulation of Mir-196b in Head and Neck Cancers Leads to Pleiotropic Effects in the Tumor Cells and Surrounding Stromal Fibroblasts.

The miR-196 family members have been found dysregulated in different cancers. Therefore, they have been proposed as promising biomarkers and therapeutic targets. This study is the first to investigate the role of miR-196b in the development and progression of head and neck squamous cell carcinomas (HNSCC), and also the impact on the surrounding tumor microenvironment. Increased miR-196b levels were detected in 95% of primary tumors and precancerous lesions, although no significant differences were observed between non-progressing versus progressing dysplasias. Furthermore, increased levels of both miR-196a and miR-196b were successfully detected in saliva samples from HNSCC patients. The functional consequences of altered miR-196 expression were investigated in both HNSCC cell lines and cancer-associated fibroblasts (CAFs) by transfection with specific pre-miR precursors. Results showed that both miR-196a and miR-196b elicit cell-specific responses in target genes and downstream regulatory pathways, and have a distinctive impact on cell proliferation, migration and invasion. These data reveal the early occurrence and prevalence of miR-196b dysregulation in HNSCC tumorigenesis, suggesting its utility for early diagnosis and/or disease surveillance and also as a non-invasive biomarker in saliva. The pleiotropic effects of miR-196a/b in HNSCC cell subpopulations and surrounding CAFs may complicate a possible therapeutic application.

Annexin A1 down-regulation in head and neck squamous cell carcinoma is mediated via transcriptional control with direct involvement of miR-196a/b.

Annexin A1 (ANXA1) down-regulation is an early and frequent event in the development of head and neck squamous cell carcinomas (HNSCC). In an attempt to identify the underlying mechanisms of reduced ANXA1 protein expression, this study investigated ANXA1 mRNA expression in HNSCC specimens by both in situ hybridization and RT-qPCR. Results showed a perfect concordance between the pattern of ANXA1 mRNA and protein detected by immunofluorescence in tumors, precancerous lesions and normal epithelia, reflecting that ANXA1 down-regulation occurs at transcriptional level. We also found that both miR-196a and miR-196b levels inversely correlated with ANXA1 mRNA levels in paired HNSCC tissue samples and patient-matched normal mucosa. In addition, endogenous levels of ANXA1 mRNA and protein were consistently and significantly down-regulated upon miR-196a and miR-196b over-expression in various HNSCC-derived cell lines. The direct interaction of both mature miR-196a and miR-196b was further confirmed by transfection with Anxa1 3'UTR constructs. Combined bioinformatics and functional analysis of ANXA1 promoter activity contributed to identify key regions and potential mediators of ANXA1 transcriptional control. This study unveils that, in addition to miR-196a, miR-196b also directly targets ANXA1 in HNSCC.

Adenocarcinoma mucinoso pulmonar con patrón de células en anillo de sello: una entidad infrecuente / Mucinous adenocarcinoma of the lung with signet-ring cell pattern: an infrequent entity

El adenocarcinoma mucinoso de pulmón con patrón de células en anillo de sello es una entidad infrecuente de diagnóstico fácil. Presentamos el caso de un paciente de 55 años con antecedente de cardiopatía isquémica y diagnóstico actual de adenocarcinoma primario pulmonar con patrón de células en anillo de sello. Es necesario descartar un origen primario extrapulmonar, principalmente de localización digestiva. Las técnicas inmunohistoquímicas son de gran utilidad a la hora de establecer diagnósticos diferenciales.

Mucinous adenocarcinoma of the lung with signet-ring cell pattern is an infrequent entity of easy diagnosis. We report the case of a 55 year-old patient with preexisting ischemic heart disease and recent diagnosis of pulmonary adenocarcinoma with signet-ring cell pattern. It is necessary discard a primary extrapulmonar location (digestive tract). Immunohistochemistry is a useful tool in the differential diagnosis.

Molecular phylogeny and evolution of the coronin gene family.

The coronin gene family comprises seven vertebrate paralogs and at least five unclassified subfamilies in nonvertebrate metazoa, fungi and protozoa, but no representatives in plants or distant protists. All known members exhibit elevated structural conservation in two unique domains of unknown function (DUF1899 and DUF1900) interspaced by three canonical WD40 domains (plus additional pseudo domains) that form part of a 7-bladed beta-propeller scaffold, plus a C-terminal variable "coiled coil domain" responsible for oligomerization. Phylogenetic analysis of the N-terminal conserved region in known members (i.e.420 aa in 250 taxa) established the origin of the founding monomeric unit and a dimeric paralog in unicellular eukaryotes. The monomeric ancestor duplicated to two distinct lineages in basal metazoa and later propagated during the whole genome duplications in primitive chordates 450-550 million years ago to form six vertebrate-specific genes. The delineation of 12 subfamily clades in distinct phyla provided a rational basis for proposing a simplified, universal nomenclature for the coronin family in accordance with evolutionary history, structural relationships and functional divergence.Comparative genomic analysis of coronin subfamily locus maps and gene organization provided corroboratory evidence for their chromosomal dispersal and structural relatedness. Statistical analysis of evolutionary sequence conservation by profile hidden Markov models (pHMM) and the prediction of Specificity Determining Positions (SDPpred) helped to characterize coronin domains by highlighting structurally conserved sites relevant to coronin function and subfamily divergence. The incorporation of such evolutionary information into 3D models facilitated the distinction between candidate sites with a structural role versus those implicated in dynamic, actin-related cytoskeletal interactions. A highly conserved "KGD" motif identified in the coronin DUF1900 domain has been observed in other actin-binding proteins such as annexins and is a potential ligand for integrins and C2 domains known to be associated with structural and signalling roles in the membrane cytoskeleton. Molecular evolution studies provide a comprehensive overview of the structural history of the coronin gene family and a systematic methodology to gain deeper insight into the function(s) of individual members.

Evolutionary and functional diversity of coronin proteins.

This chapter discusses various aspects of coronin phylogeny, structure and function that are of specific interest. Two subfamilies of ancient coronins of unicellular pathogens such as Entamoeba, Trypanosoma, Leishmania and Acanthamoeba as well as of Plasmodium, Babesia, and Trichomonas are presented in the first two sections. Their coronins generally bind to F-actin and apparently are involved in proliferation, locomotion and phagocytosis. However, there are so far no studies addressing a putative role of coronin in the virulence of these pathogens. The following section delineates genetic anomalies like the chimeric coronin-fusion products with pelckstrin homology and gelsolin domains that are found in amoeba. Moreover, most nonvertebrate metazoa appear to encode CRN8, CRN9 and CRN7 representatives (for these coronin symbols see Chapter 2), but in e.g., Drosophila melanogaster and Caenorhabditis elegans a CRN9 is missing. The forth section deals with the evolutionary expansion of vertebrate coronins. Experimental data on the F-actin binding CRN2 of Xenopus (Xcoronin) including a Cdc42/Rac interactive binding (CRIB) motif that is also present in other members of the coronin protein family are discussed. Xenopus laevis represents a case for the expansion of the seven vertebrate coronins due to tetraploidization events. Other examples for a change in the number of coronin paralogs are zebrafish and birds, but (coronin) gene duplication events also occurred in unicellular protozoa. The fifth section of this chapter briefly summarizes three different cellular processes in which CRN4/CORO1A is involved, namely actin-binding, superoxide generation and Ca(2+)-signaling and refers to the largely unexplored mammalian coronins CRN5/CORO2A and CRN6/CORO2B, the latter binding to vinculin. The final section discusses how, by unveiling the aspects of coronin function in organisms reported so far, one can trace a remarkable evolution and diversity in their individual roles anticipating a rather complex and intricate involvement of coronins in a variety of cellular processes.

Protocolo de asepsia y utilización adecuada de recursos en hemodiálisis / No disponible

No disponible

Annexin A2 localizes to the basal epithelial layer and is down-regulated in dysplasia and head and neck squamous cell carcinoma.

Annexin A2 is a highly expressed gene with important roles in cell membrane physiology and is frequently dysregulated in cancer. The objective of this study was to determine the pattern of expression and prognostic significance of annexin A2 protein in head and neck squamous cell carcinoma. We assessed both quantitative changes and qualitative distribution of annexin A2 mRNA and protein expression in normal and diseased tissues by immunohistochemistry, immunofluorescence and in situ hybridization. Annexin A2 expression was confined to the basal and suprabasal cells of normal epithelium and the protein cellular location was consistently observed at the cell membrane. Expression levels correlated with histopathological grade, showing significant suppression in moderately and poorly differentiated tumours. We conclude that annexin A2 exhibits a characteristic pattern of expression, distinct from other annexins and suggestive of a cell-specific functional role. The marked reduction of annexin A2 in poorly differentiated tumours and dysplastic tissue is expected to result in a loss of function aimed at the coordination of membrane signalling enzyme complexes, actin polymerization and extracellular matrix proteolysis. The phenotypic consequences may become manifest in an alteration of epithelial tissue growth and remodelling with secondary influence on tumour development, progression and metastasis.

Annexin A1 expression in nasopharyngeal carcinoma correlates with squamous differentiation.

BACKGROUND: Alterations of annexin A1 (ANXA1) expression have been reported in various cancers. However, no data are available about the expression of this protein in nasopharyngeal carcinomas (NPCs). The objective of this study was to investigate the expression of ANXA1 in these tumors. METHODS: We examined noncancerous nasopharyngeal mucosa (4 cases) and NPC (20 cases) for ANXA1 expression using immunohistochemistry. RESULTS: All tumor tissues showed markedly reduced ANXA1 expression compared with a strong positive signal observed in the corresponding normal epithelia. We found that ANXA1 expression is associated with the histological type in NPC. Only squamous cell carcinomas presented a positive ANXA1 signal in differentiated areas whereas all poorly differentiated tumors exhibited negative staining. CONCLUSION: Our data show for the first time that ANXA1 expression is down-regulated in NPC and that its expression seems to be related with the squamous differentiation status of these tumors.

Annexin A1 down-regulation in head and neck cancer is associated with epithelial differentiation status.

Annexin A1 (ANXA1) protein expression was evaluated by Western blot in a series of 32 head and neck squamous cell carcinomas (HNSCCs) in a search for molecular alterations that could serve as useful diagnostic/prognostic markers. ANXA1 down-regulation was observed in 24 cases (75%) compared with patient-matched normal epithelium. In relation to clinicopathological variables, ANXA1 down-regulation was significantly associated with advanced T stages (P = 0.029), locoregional lymph node metastases (P = 0.038), advanced disease stage (P = 0.006), hypopharyngeal localization (P = 0.038), and poor histological differentiation (P = 0.005). ANXA1 expression was also analyzed by immunohistochemistry in paraffin-embedded sections from 22 of 32 HNSCCs and 8 premalignant lesions. All dysplastic tissues showed significantly reduced ANXA1 expression compared to a strong positive signal observed in adjacent normal epithelia (except basal and suprabasal cells). A close association was observed between ANXA1 expression and the histological grade in HNSCC. Well-differentiated tumors presented a positive ANXA1 signal in highly keratinized areas whereas moderately and poorly differentiated tumors exhibited very weak or negative staining. Our findings clearly identify ANXA1 as an effective differentiation marker for the histopathological grading of HNSCCs and for the detection of epithelial dysplasia.

Relationship between changes in drug score, D-glucaric acid excretion, and gamma-glutamyltransferase and beta-glucuronidase serum activities during anticonvulsant treatment.

The purpose of this study was to investigate the relationship of changes in the enzyme-inducing anticonvulsant daily dosage (drug score) to variations in urinary D-glucaric acid excretion and gamma-glutamyltransferase and beta-glucuronidase serum activities. These biochemical determinations were carried out before and after a mean period of 5.0 years in 16 adult epileptic patients (8 men and 8 women) treated with phenobarbital, phenytoin and/or carbamazepine and with a good therapeutic compliance. A significant correlation between D-glucaric acid excretion and drug score was obtained (r=0.508, p<0.001). When the interindividual variation was diminished by assessing the changes of these variables in the same subjects, the correlation was better (r=0.836, p<0.001). However, a statistical significance was not attained between the gamma-glutamyltransferase or beta-glucuronidase and drug score changes. Therefore the urinary excretion of D-glucaric acid appears to be more sensitive to changes in anticonvulsant drug score than serum gamma-glutamyltransferase and beta-glucuronidase.

Acidos grasos esengiales en eritrocitos de sangre umbilical de recién nacidos prematuros y de término, pequeños o adecuados a la edad gestacional / Essential fatty acids in cord blood erythrocytes for premature and term neonates, both small and adequate for gestational age

Objetivos: Comparar la composición porcentual de los ácidos grasas esenciales poliinsaturados de cadena larga en los fosfolípidos de los eritrocitos de lo sangre de cordón en nacidos de término y pretérmino. Método: La composición porcentual de los ácidos grasas escenciales se determinó por cromatograpia gas-líquido en once recién nacidos de término con peso adecuado para la edadgestacional, once de término pequeños para la edad gestacional y 22prematuros sanos de peso adecuado para la edad gestacional. Resultados: Con respecto los nacidos de término com peso adecuado, los contenidos de ácido araquidónico (20:4 6; ARA) v de ácido dcosahexaenoico (22:6 3; DHA) estaban significativamente diminuidos (p < 0,05) en los eritrocitos de los nacidos pretérmino de peso adecuado. En los de término pequeños sólo era menor la proporción de DHA (p < 0,05), mientras que el porcentaje de ácido linoleico (18:2 6) estaban aumentado, la relación ARA/DHA en los fosfolípidos diferenció significativamente (p < 0,05) a los tres grupos de recién nacidos, siendo menor (2,82) en los de término adecuados, intermedia en los pretérmino (3,46) y más alta (4,22) en los de término pequeños. Conlusión: Probablemente el apoyo nutricional perinatal con ácidos grasas poliinsaturados de cadena larga tendría que ser diferente para los recién nacidos de bajo peso de nacimiento prematuros y de término

Acidos grasos esenciales en eritrocitos de sangre umbilical de recién nacidos prematuros y de término, pequeños o adecuados a la edad gestacional / Essential fatty acids in red blood cells from umbilical cord of preterm and full term newborn infants with either adequate or low bithweight for gestational age

Objetivo: comparar la composición porcentual de los ácidos grasas esenciales poliinsaturados de cadena largo en los fosfolípidos de los eritrocitos de la sangre de cordón en racidos de término y pretérmino. Método: la composición porcenpual de los ácidos grasos escenciales se determinó por cromatografía gas-líquido en once recién nacidos de término con peso adecuado para la edad gestacional, 11 de término pequeños para la edad gestacional y 22 prematuros sanos de peso adecuado para la edad gestacional. Resultados: con respecto los nacidos de término con peso adecuado, los contenidos de ácidos arquidónico (20:4 w 6; ARA) y de ácido docosahexaenoico (22:6 w 3; DHA) estaban significativamente disminuidos (p <0,05) en los eritrocitos de los nacidos pretérmino de peso adecuado. En los de término pequeños sólo era menor la proporción de DHA (p< 0,05), mientras que el porcentaje de ácido linoleico (18:2 v 6) estaba aumentado. La relación ARA/DHA en los fosfolípidos diferenció significativamente (p< 0,05) a los tres grupos de recién nacidos, siendo menor (2,82) en los de término adecuados, intermedia en los pretérmino (3,46) y más alta (4,22) en los de término pequeños. Conclusión: probablemente el apoyo nutricional perinatal con ácidos grasos poliinsaturados de cadena larga tendría que ser diferente para los recién nacidos de bajo peso de nacimiento prematuros y de término