Diatoms as a paleoproductivity proxy in the NW Iberian coastal upwelling system (NE Atlantic)

The objective of the current work is to improve our understanding of how water column diatom's abundance and assemblage composition is seasonally transferred from the photic zone to seafloor sediments. To address this, we used a dataset derived from water column, sediment trap and surface sediment samples recovered in the NW Iberian coastal upwelling system. Diatom fluxes (2.2 (+/- 5.6) 10(6) valves m(-2) d(-1)) represented the majority of the siliceous microorganisms sinking out from the photic zone during all studied years and showed seasonal variability. Contrasting results between water column and sediment trap diatom abundances were found during downwelling periods, as shown by the unexpectedly high diatom export signals when diatom- derived primary production achieved their minimum levels. They were principally related to surface sediment remobilization and intense Minho and Douro river discharge that constitute an additional source of particulate matter to the inner continental shelf. In fact, contributions of allochthonous particles to the sinking material were confirmed by the significant increase of both benthic and freshwater diatoms in the sediment trap assemblage. In contrast, we found that most of the living diatom species blooming during highly productive upwelling periods were dissolved during sinking, and only those resistant to dissolution and the Chaetoceros and Leptocylindrus spp. resting spores were susceptible to being exported and buried. Fur-thermore, Chaetoceros spp. dominate during spring-early summer, when persistent northerly winds lead to the upwelling of nutrient-rich waters on the shelf, while Leptocylindrus spp. appear associated with late-summer upwelling relaxation, characterized by water column stratification and nutrient depletion. These findings evidence that the contributions of these diatom genera to the sediment's total marine diatom assemblage should allow for the reconstruction of different past upwelling regimes.CAIBEX [CTM2007-66408-C02-01/MAR]; REIMAGE [CTM2011-30155-C03-03]; Spanish Government, EXCAPA project [10MDS402013PR]; Xunta de Galicia; EU FEDER [INTERREG 2009/2011-0313/RAIA/E]; RAIA. co [INTERREG2011/2013-052/RAIA.co/1E]; CALIBERIA project [PTDC/MAR/102045/2008]; Fundacao para a Ciencia e a Tecnologia (FCT-Portugal) [COMPETE/FEDER-FCOMP01-0124-FEDER-010599]; Xunta de Galicia (Spain) [SFRH/BPD/111433/2015]; FCT (Portugal) [SFRH/BPD/111433/2015]; [SFRH/BD/88439/2012

La anatomía en México: un vistazo a la historia

La anatomía es una de las ciencias médicas más antiguas, y en su evolución histórica ha pasado por diversos periodos. En México ha permanecido en los currículos de las escuelas de medicina en forma bastante discreta y sin grandes cambios, conservando su formato y técnicas de enseñanza. En nuestros días son necesarios algunos cambios para actualizar los contenidos y, sobre todo, empatarlos con las tendencias curriculares actuales. Este artículo muestra una revisión general de los periodos por las que ha pasado la anatomía en nuestro país, precolonial (a.C.-1521), poscolonial (1521-1910), moderna (1910-2000) y actual (2000-presente)

iTRAQ Quantitative Proteomic Analysis of Vitreous from Patients with Retinal Detachment

Rhegmatogenous retinal detachment (RRD) is a potentially blinding condition characterized by a physical separation between neurosensory retina and retinal pigment epithelium. Quantitative proteomics can help to understand the changes that occur at the cellular level during RRD, providing additional information about the molecular mechanisms underlying its pathogenesis. In the present study, iTRAQ labeling was combined with two-dimensional LC-ESI-MS/MS to find expression changes in the proteome of vitreous from patients with RRD when compared to control samples. A total of 150 proteins were found differentially expressed in the vitreous of patients with RRD, including 96 overexpressed and 54 underexpressed. Several overexpressed proteins, several such as glycolytic enzymes (fructose-bisphosphate aldolase A, gamma-enolase, and phosphoglycerate kinase 1), glucose transporters (GLUT-1), growth factors (metalloproteinase inhibitor 1), and serine protease inhibitors (plasminogen activator inhibitor 1) are regulated by HIF-1, which suggests that HIF-1 signaling pathway can be triggered in response to RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Also, the accumulation of photoreceptor proteins, including phosducin, rhodopsin, and s-arrestin, and vimentin in vitreous may indicate that photoreceptor degeneration occurs in RRD. Nevertheless, the differentially expressed proteins found in this study suggest that different mechanisms are activated after RRD to promote the survival of retinal cells through complex cellular responses.CENTRO-07-ST24-FEDER-002014; POCI-01-0145-FEDER-007491; CNB-CSIC proteomics lab is a member of ProteoRed, supported by PRB2-ISCIII grant [PT13/0001]; Novartis Farma-Produtos Farmacêuticos; PhD fellowship of Sciences Faculty financed by ICI and Santander.info:eu-repo/semantics/publishedVersio

Neutrophil gelatinase-associated lipocalin in kidney transplantation is an early marker of graft dysfunction and is associated with one-year renal function

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) has been suggested as potential early marker of delayed graft function (DGF) following kidney transplantation (KTx). We conducted a prospective study in 40 consecutive KTx recipients to evaluate serial changes of uNGAL within the first week after KTx and assess its performance in predicting DGF (dialysis requirement during initial posttransplant week) and graft function throughout first year. Urine samples were collected on post-KTx days 0, 1, 2, 4, and 7. Linear mixed and multivariable regression models, receiver-operating characteristic (ROC), and areas under ROC curves were used. At all-time points, mean uNGAL levels were significantly higher in patients developing DGF (n = 18). Shortly after KTx (3-6 h), uNGAL values were higher in DGF recipients (on average +242 ng/mL, considering mean dialysis time of 4.1 years) and rose further in following days, contrasting with prompt function recipients. Day-1 uNGAL levels accurately predicted DGF (AUC-ROC = 0.93), with a performance higher than serum creatinine (AUC-ROC = 0.76), and similar to cystatin C (AUC-ROC = 0.95). Multivariable analyses revealed that uNGAL levels at days 4 and 7 were strongly associated with one-year serum creatinine. Urinary NGAL is an early marker of graft injury and is independently associated with dialysis requirement within one week after KTx and one-year graft function.The authors recognize and thank Abbott Laboratories for their valuable contribution for donating kits used for testing almost 200 samples. The remaining kits were financed by funds of Unit for Multidisciplinary Investigation in Biomedicine, Porto, Portuga

Pancreas-Kidney Transplantation: Analysis of 150 patients from one Centre in Portugal

Introduction: Simultaneous pancreas-kidney transplantation (SPKT) outcomes are conditioned in the short-term mostly by post-operative complications. In the long-term, cardiovascular (CV) disease and immunological loss are the main limitations to transplant survival. Aims: To analyse retrospectively the results from 150 SPKT performed at our centre. Patients and Methods: The 81 females and 69 males had a mean age of 35±6 years; they were diabetic for 24±6 years and had been on dialysis for 30±21months (except 5 preemptive). Anti-lymphocyte globulin, tacrolimus, mycophenolate and steroids were used as immunosuppressive therapy. Deceased-donor mean age was 28±11 years. In 28.7% the transplant was performed with 6 HLA-mismatches. Results: Acute rejection’s incidence was 16%. Ten SPKT patients died; infection was the leading cause of death (five cases), followed by Cardiovascular/cerebrovascular disease (three cases). In 21 patients the pancreas failed, mainly due to thrombosis or bleeding (11 cases), and infection (five cases); in two it was due to late acute rejection. In four patients only the kidney failed, due to chronic rejection. Five patients lost both grafts, from late acute rejection in four and thrombosis in one. We analyzed the 110 SPKT patients (73.3%) with both grafts functioning. Their mean serum creatinine was 1.2±0.4mg/dl; creatinineclearance was 76±24 ml/min; fasting glycaemia was 81±10mg/dl; and HbA1c was 5.3±0.4%. Hypertension has been treated in 47.2% of patients, in the majority (28.2%) with only one drug. Hyperlipidaemia was observed in 19.1% and excessive weight (>25kg/m2) in 17.3%. Conclusions: From our cohort of SPKT, 93.3% of patients are alive, 73.3% have both grafts functioning. Rejection was the main cause of late pancreas loss. Early mortality was due to infection (3.3%). CV/cerebrovascular disease was the main cause of late mortality (2%). The prevalence of hyperlipidaemia and overweight was inferior to 20%. Hypertension was the most frequently found CV risk factor

Spatial and temporal variability in coccolithophore abundance and distribution in the NW Iberian coastal upwelling system

A systematic investigation of the spatial and temporal variability in coccolithophore abundance and distribution through the water column of the NW Iberian coastal up-welling system was performed. From July 2011 to June 2012, monthly sampling at various water depths was conducted at two parallel stations located at 42 degrees N. Total coccosphere abundance was higher at the outer-shelf station, where warmer, nutrient-depleted waters favoured coccolithophore rather than phytoplanktonic diatom blooms, which are known to dominate the inner-shelf location. In seasonal terms, higher coccosphere and coccolith abundances were registered at both stations during upwelling seasons, coinciding with high irradiance levels. This was typically in conjunction with stratified, nutrient-poor conditions (i.e. relaxing upwelling conditions). However, it also occurred during some upwelling events of colder, nutrient-rich subsurface waters onto the continental shelf. Minimum abundances were generally found during downwelling periods, with unexpectedly high coccolith abundance registered in subsurface waters at the inner-shelf station. This finding can only be explained if strong storms during these downwelling periods favoured resuspension processes, thus remobilizing deposited coccoliths from surface sediments, and hence hampering the identification of autochthonous coccolithophore community structure. At both locations, the major coccolithophore assemblages were dominated by Emiliania huxleyi, small Gephyrocapsa group, Gephyrocapsa oceanica, Florisphaera profunda, Syracosphaera spp., Coronosphaera mediterranea, and Calcidiscus leptoporus. Ecological preferences of the different taxa were assessed by exploring the relationships between environmental conditions and temporal and vertical variability in coccosphere abundance. These findings provide relevant information for the use of fossil coccolith assemblages in marine sediment records, in order to infer past environmental conditions, of particular importance for Paleoceanography. Both E. huxleyi and the small Gephyrocapsa group are proposed as proxies for the upwelling regime with a distinct affinity for different stages of the upwelling event: E. huxleyi was associated with warmer, nutrient-poor and more stable water column (i.e. upwelling relaxation stage) while the small Gephyrocapsa group was linked to colder waters and higher nutrient availability (i.e. early stages of the upwelling event), similarly to G. oceanica. Conversely, F. profunda is suggested as a proxy for the downwelling regime and low-productivity conditions. The assemblage composed by Syracosphaera pulchra, Coronosphaera mediterranea, and Rhabdosphaera clavigera may be a useful indicator of the presence of subtropical waters conveyed northward by the Iberian Poleward Current. Finally, C. leptoporus is proposed as an indicator of warmer, saltier, and oligotrophic waters during the downwelling/winter regime.EXCAPA project - Xunta de Galicia [10MDS402013PR]; CALIBERIA project (Fundacao para a Ciencia e a Tecnologia - Portugal) [PTDC/MAR/102045/2008]; CALIBERIA project [COMPETE/FEDER-FCOMP-01-0124-FEDER-010599, BI/PTDC/MAR/102045/2008/2010-016, BI/PTDC/MAR/102045/2008/2010-022, BI/PTDC/MAR/102045/2008/2011-027]; Ministerio de Economia y Competitividad [CGL2015-68459-P]; Ministry of Education of Spain [AP2010-2559]; ETH Zurich Postdoctoral Fellowship from the Swiss Federal Institute of Technology in Zurich (ETHZ); Xunta de Galicia (Spain); FCT [SFRH/BPD/111433/2015]; Plurianual/Estrategico project [UID/Multi/04326/2013]info:eu-repo/semantics/publishedVersio

Anatomical Variants of Anterior Cerebral Arterial Circle: A Study by Multidetector Computerized 3D Tomographic Angiography

SUMMARY: One of the most common causes of stroke is rupture of aneurysms whose approach requires knowledge of anatomical variants. The aim of this study was to determine the prevalence of anatomical variants of the anterior cerebral artery (ACA) and the anterior communicating artery (AComA) by 3D computed tomography angiography (3D CTA) in Mexican individuals. A retrospective, observational, cross-sectional descriptive study of 283 patients, independent of sex or age, in which morphometric measurements of cerebral vessels were evaluated using contrasted 3D CTA from a period of two years was performed. We found at least one "atypical" variant in a third of the study population (33.93 %). The most common "atypical" variant was the absence of the AComA (14.1 %). A significant association between the hypoplastic variant of the right A1 segment and hypoplasia of the left A1 and the right A2 was found, while hypoplasia of the left A1 was associated with hypoplasia of the right A2. There is a difference in the prevalence of anatomical variants of the ACA-AComA complex in Mexican population in relation to other populations. The typical variant is the most prevalent form in the study population. However, the presence of atypical variants represents an important number that should be taken into account in clinical and surgical procedures. KEY WORDS: Anterior cerebral artery; Anatomical variant; Anterior communicating artery; Cerebral arterial circle; Subarachnoid hemorrhage; Cerebral endovascular surgery