Sarcopenia y albúmina sanguínea: revisión sistemática con metaanálisis

Sarcopenia is characterized by loss of muscle mass during aging, which can have consequences for the individuals'' health. There are many ways to detect it, among them, with the use of blood biomarkers such as albumin, although the association between the two has not been confirmed yet.This review synthesizes the knowledge on the association between sarcopenia and serum albumin among elderly individuals through a systematic review and meta-analysis focused on the etiology and risk factors. We used the Joanna Briggs Institute software for the review and conducted a search in MEDLINE, Embase, CINAHL, and LILACS databases while two reviewers conducted an independent manual search. EpiDat, version 3.1 was used for the meta-analysis; mean differences with the albumin scores disaggregated by sarcopenia were analyzed by the random-effects model. The degree of heterogeneity was assessed with the DerSimonian and Laird Q test.We analyzed 630 articles and finally included 14 in the review. Higher blood albumin levels were found in the meta-analysis, which was statistically significant among the elderly adults who did not present sarcopenia compared to those who did. Although there are studies exploring the association between albumin and sarcopenia, there is a need to continue evaluating its association with biological markers and comparing them to verify which can be used to detect sarcopenia among the elderly.     

Melanocortin-4 receptor gene mutations in a Dutch cohort of obese children

The most common monogenic form of obesity is caused by mutations in the gene encoding the melanocortin-4 receptor (MC4R). We have screened the MC4R coding sequence in 291 patients of a Dutch outpatient pediatric obesity clinic. We analyzed the minimal promoter region of the gene in a random subgroup of 217 children. Our aims were (i) to determine the frequency of MC4R mutations in a cohort of Dutch clinically obese children and (ii) to search for mutations in the promoter of the gene. Eleven MC4R coding variants were detected. Five children had mutations that have been shown to affect receptor function by other research groups (p.Y35X, p.I251fs, p.G231S). These children did not have earlier onset of obesity or higher BMI-SDS than the remainder of the cohort. One child had a novel nonsynonymous coding mutation (p.L304F). This variant showed a markedly decreased cell surface expression in in vitro experiments and is thus expected to be pathogenic. We detected 12 variants in the MC4R flanking regions. Five of these were not previously described (c.-1101C>T, c.-705A>T, c.-461A>G, c.-312T>C, c.-213A>G). We investigated these mutations by family studies and a bioinformatic approach. We conclude that rare heterozygous mutations in the coding sequence of MC4R account for some severe obesity cases in the Dutch population. These patients are difficult to recognize in a clinical setting. We generated a list of all MC4R variants that were described in the literature so far, which can aid the interpretation of mutations found in a diagnostic setting.     

Phylogenetic position of Zygogonium ericetorum (Zygnematophyceae,Charophyta) from a high alpine habitat and ultrastructural characterization of unusual aplanospores

Zygogonium ericetorum, the type species of the genus, was studied from a natural population collected in Mt. Schönwieskopf, Tyrol, Austria. Generic concepts of Zygogonium and Zygnema were tested with atpB, psbC, and rbcL gene sequence analysis, which showed a sister relationship between Z. ericetorum and Mesotaenium, in an early branching clade sister to a grouping of Zygnema and several other filamentous and unicellular zygnematalean taxa. A variety of light, confocal, transmission electron microscopy, and cytochemical techniques provided new data on the variable chloroplast shape of Z. ericetorum, and its aplanospore structure and development, which has been previously considered taxonomically important but has been ambiguously interpreted. Zygogonium can be distinguished from other zygnematophytes (particularly Zygnema), based on the combination of two characters: (i) irregular, compressed plate‐like chloroplasts and (ii) residual cytoplasmic content left in sporangia outside of the fully developed aplanospores or zygospores. The presence of a sporangial wall that separates the spores from the parent cell should be excluded from the definition of Zygogonium, because it is also observed in Zygnema. Similarly, the ecological characterization of Zygogonium as acidophilic is not unique to the genus. The names of 18 species currently belonging to Zygogonium are here changed to Zygnema, because of incompatibility with this new proposed Zygogonium concept. In the species transferred to Zygnema, chloroplasts are typically stellate in three‐dimensions, and the entire content of fertile cells is transformed into the spore, so there is no cytoplasmic residue.     

Bryophytes of Europe Traits (BET) data set: A fundamental tool for ecological studies

Bryophytes are a diverse group of organisms with unique properties, yet they are severely underrepresented in plant trait databases. Building on the recently published European Red List of bryophytes and previous trait compilations, we present the Bryophytes of Europe Traits (BET) data set, including biological traits such as those related to life history, growth habit, sexual and vegetative reproduction; ecological traits such as indicator values, substrate and habitat; and bioclimatic variables based on the species' European range. The data set includes values for 65 traits and 25 bioclimatic variables, containing more than 135,000 trait values with a completeness of 82.7% on average. The data set will enable future studies in bryophyte biology, ecology and conservation, and may help to answer fundamental questions in bryology.     

Coagulant thrombin-like enzyme (barnettobin) from Bothrops barnetti venom: Molecular sequence analysis of its cDNA and biochemical properties

The thrombin-like enzyme from Bothrops barnetti named barnettobin was purified. We report some biochemical features of barnettobin including the complete amino acid sequence that was deduced from the cDNA. Snake venom serine proteases affect several steps of human hemostasis ranging from the blood coagulation cascade to platelet function. Barnettobin is a monomeric glycoprotein of 52 kDa as shown by reducing SDS-PAGE, and contains approx. 52% carbohydrate by mass which could be removed by N-glycosidase. The complete amino acid sequence was deduced from the cDNA sequence. Its sequence contains a single chain of 233 amino acid including three N-glycosylation sites. The sequence exhibits significant homology with those of mammalian serine proteases e.g. thrombin and with homologous TLEs. Its specific coagulant activity was 251.7 NIH thrombin units/mg, releasing fibrinopeptide A from human fibrinogen and showed defibrinogenating effect in mouse. Both coagulant and amidolytic activities were inhibited by PMSF. N-deglycosylation impaired its temperature and pH stability. Its cDNA sequence with 750 bp encodes a protein of 233 residues. Indications that carbohydrate moieties may play a role in the interaction with substrates are presented. Barnettobin is a new defibrinogenating agent which may provide an opportunity for the development of new types of anti-thrombotic drugs.     

Environment and cancer in Brazil: an overview from a public health perspective

This paper presents the current pattern of cancer incidence in Brazil by analyzing the country's cancer epidemiological profile. The authors highlight the observed overlapping distribution of cancer incidence in Brazil in tumor sites normally associated with higher socioeconomic status (cancers of the breast, prostate, and colon/rectum, among others) and poverty (cervix, stomach, oral cavity, and penis). In addition to analyzing the demographic and social characteristics associated with current epidemiological distribution of cancer in Brazil, the authors present several of the most important environmental risk factors (smoking and exposure to radiation, pesticides, and other chemicals) and discuss their respective exposure levels in the Brazilian context.The article concludes with an evaluation of the principal challenges facing environmental cancer control programs in Brazil, particularly focusing on smoking and exposure to chemicals.     

The iterative process of plant species inventorying for obtaining reliable biodiversity patterns

We require representative data of species occurrence to explain plant diversity patterns, but most of the available information is incomplete and biased. To improve our knowledge, we suggest that species inventorying should be an iterative process encompassing the following: (1) the detection of taxonomic and geographical gaps; (2) the planning of a survey design to reduce such gaps; and (3) the evaluation of field sampling results. Here, we focus on the latter phase for the bryophytes of Terceira Island (Azores) for which we have previously estimated < 1% of the area as well surveyed based on historical collections. To examine the performance of our stratified survey based on two factors (land use and environmental regions), we used rarefaction curves, ANOVA tests and bootstrap sampling. We recorded 40% of all the species known for the island and presented eight new citations. The species assemblages remained similar between historical and current inventories. Most localities had completeness values > 85%, but we always exceeded the optimal sampling effort. Land uses and environmental regions affected species diversity, but, unexpectedly, to a different degree. Our study illustrates the difficulties of planning field surveys to obtain reliable biodiversity patterns, even when prior information and standardized sampling protocols are explicitly considered. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 491–503.     

Resolving the Azorean knot: a response to Carine & Schaefer (2010)

Carine & Schaefer (Journal of Biogeography, 2010, 37 , 77–89) suggest that the lack of past climate oscillations in the Azores may have contributed to the low plant endemism in this archipelago compared to that of the Canary Islands, a pattern they term the Azorean diversity enigma. Here we challenge their hypothesis, and discuss how the particular characteristics of the Azores may have driven current diversification patterns in this archipelago. We argue that the restricted number of Azorean endemic species and their wide distribution is explicable by the geological, geographical and ecological attributes of the archipelago. That is, the Azores are too young, too small, and too environmentally homogeneous to have hosted many in situ diversification events, so they do not host as many endemic species as other Macaronesian archipelagos, such as Madeira and especially the Canary Islands.