Trait biogeography of marine copepods – an analysis across scales

Functional traits, rather than taxonomic identity, determine the fitness of individuals in their environment: traits of marine organisms are therefore expected to vary across the global ocean as a function of the environment. Here, we quantify such spatial and seasonal variations based on extensive empirical data and present the first global biogeography of key traits (body size, feeding mode, relative offspring size and myelination) for pelagic copepods, the major group of marine zooplankton. We identify strong patterns with latitude, season and between ocean basins that are partially (c. 50%) explained by key environmental drivers. Body size, for example decreases with temperature, confirming the temperature‐size rule, but surprisingly also with productivity, possibly driven by food‐chain length and size‐selective predation. Patterns unrelated to environmental predictors may originate from phylogenetic clustering. Our maps can be used as a test‐bed for trait‐based mechanistic models and to inspire next‐generation biogeochemical models.     

Effect of Sodium Bicarbonate Administration on Mortality in Patients with Lactic Acidosis: A Retrospective Analysis

Background

Lactic acidosis is a common cause of high anion gap metabolic acidosis. Sodium bicarbonate may be considered for an arterial pH <7.15 but paradoxically depresses cardiac performance and exacerbates acidosis by enhancing lactate production. This study aimed to evaluate the cause and mortality rate of lactic acidosis and to investigate the effect of factors, including sodium bicarbonate use, on death.

Methods

We conducted a single center analysis from May 2011 through April 2012. We retrospectively analyzed 103 patients with lactic acidosis among 207 patients with metabolic acidosis. We used SOFA and APACHE II as severity scores to estimate illness severity. Multivariate logistic regression analysis and Cox regression analysis models were used to identify factors that affect mortality.

Results

Of the 103 patients with a mean age of 66.1±11.4 years, eighty-three patients (80.6%) died from sepsis (61.4%), hepatic failure, cardiogenic shock and other causes. The percentage of sodium bicarbonate administration (p = 0.006), catecholamine use, ventilator care and male gender were higher in the non-survival group than the survival group. The non-survival group had significantly higher initial and follow-up lactic acid levels, lower initial albumin, higher SOFA scores and APACHE II scores than the survival group. The mortality rate was significantly higher in patients who received sodium bicarbonate. Sodium bicarbonate administration (p = 0.016) was associated with higher mortality. Independent factors that affected mortality were SOFA score (Exp (B) = 1.72, 95% CI = 1.12–2.63, p = 0.013) and sodium bicarbonate administration (Exp (B) = 6.27, 95% CI = 1.10–35.78, p = 0.039).

Conclusions

Lactic acidosis, which has a high mortality rate, should be evaluated in patients with metabolic acidosis. In addition, sodium bicarbonate should be prescribed with caution in the case of lactic acidosis because sodium bicarbonate administration may affect mortality.     

Morphological,molecular and MALDI-TOF MS identification of ticks and tick-associated pathogens in Vietnam

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been reported as a promising and reliable tool for arthropod identification, including the identification of alcohol-preserved ticks based on extracted leg protein spectra. In this study, the legs of 361 ticks collected in Vietnam, including 251 Rhiphicephalus sanguineus s.l, 99 Rhipicephalus (Boophilus) microplus, two Amblyomma varanensis, seven Dermacentor auratus, one Dermacentor compactus and one Amblyomma sp. were submitted for MALDI-TOF MS analyses. Spectral analysis showed intra-species reproducibility and inter-species specificity and the spectra of 329 (91%) specimens were of excellent quality. The blind test of 310 spectra remaining after updating the database with 19 spectra revealed that all were correctly identified with log score values (LSV) ranging from 1.7 to 2.396 with a mean of 1.982 ± 0.142 and a median of 1.971. The DNA of several microorganisms including Anaplasma platys, Anaplasma phagocytophilum, Anaplasma marginale, Ehrlichia rustica, Babesia vogeli, Theileria sinensis, and Theileria orientalis were detected in 25 ticks. Co-infection by A. phagocytophilum and T. sinensis was found in one Rh. (B) microplus.     

心房钠泵因子对颈动脉窦压力感受器反射的易化作用

Effects of atriopeptin II (APII) on the carotid sinus baroreflex in anesthetized rats and on the sinus nerve afferent activity in the anesthetized rabbits were investigated. The results were as follows: (1) By perfusing the isolated left carotid sinus with APII (1 microgram/ml) in anesthetized rats (n = 10), the threshold pressure (TP) of the carotid baroreflex did not show any change, while the equilibrium pressure (EP), the saturation pressure (SP) and the operating range (OR) were decreased from 101 +/- 2.8 to 95 +/- 2.0 mmHg (P less than 0.05), 202 +/- 5.2 to 168 +/- 6.1 mmHg (P less than 0.001) and 128 +/- 5.5 to 93 +/- 6.3 mmHg (P less than 0.001), respectively. The function curve of the baroreflex was shifted to the left and downward with a peak slope (PS) increased during perfusing with APII. In contrast, by perfusing the carotid sinus with sodium nitroprusside (NP, 0.5 micrograms/ml), TP and EP remained unchanged, whereas SP and OR were increased from 188 +/- 6.4 to 218 +/- 6.0 mmHg (n = 6, P less than 0.01) and from 107 +/- 6.9 to 132 +/- 7.6 mmHg (P less than 0.05), respectively. The function curve of the baroreflex and its PS were not affected by NP. The sinus nerve afferent activity was quite stable with the perfusion of carotid sinus at constant intrasinus pressure (ISP) in the rabbits (n = 6) and increased during the elevation of ISP.(ABSTRACT TRUNCATED AT 250 WORDS)     

Caffeinated coffee, decaffeinated coffee, and the phenolic phytochemical chlorogenic acid up-regulate NQO1 expression and prevent H₂O₂-induced apoptosis in primary cortical neurons

Neurodegenerative disorders are strongly associated with oxidative stress, which is induced by reactive oxygen species including hydrogen peroxide (H₂O₂). Epidemiological studies have suggested that coffee may be neuroprotective, but the molecular mechanisms underlying this effect have not been clarified. In this study, we investigated the protective effects of caffeinated coffee, decaffeinated coffee, and the phenolic phytochemical chlorogenic acid (5-O-caffeoylquinic acid), which is present in both caffeinated and decaffeinated coffee, against oxidative neuronal death. H₂O₂-induced apoptotic nuclear condensation in neuronal cells was strongly inhibited by pretreatment with caffeinated coffee, decaffeinated coffee, or chlorogenic acid. Pretreatment with caffeinated coffee, decaffeinated coffee, or chlorogenic acid inhibited the H₂O₂-induced down-regulation of anti-apoptotic proteins Bcl-2 and Bcl-X_L while blocking H₂O₂-induced pro-apoptotic cleavage of caspase-3 and pro-poly(ADP-ribose) polymerase. We also found that caffeinated coffee, decaffeinated coffee, and chlorogenic acid induced the expression of NADPH:quinine oxidoreductase 1 (NQO1) in neuronal cells, suggesting that these substances protect neurons from H₂O₂-induced apoptosis by up-regulation of this antioxidant enzyme. The neuroprotective efficacy of caffeinated coffee was similar to that of decaffeinated coffee, indicating that active compounds present in both caffeinated and decaffeinated coffee, such as chlorogenic acid, may drive the effects.     

Inhibition of lipopolysaccharide-induced inducible nitric oxide synthase expression by endoplasmic reticulum stress

Endoplasmic reticulum (ER) stress is induced in infectious and inflammatory conditions, but its role in inflammatory responses still remains elusive. In this study we found tunicamycin (TM) and brefeldin A (BFA), two ER stressors, could attenuate lipopolysaccharide (LPS)-elicited inducible nitric oxide synthase (iNOS) gene expression in murine RAW264.7 macrophages, and this effect was not resulting from the effects on IKK or MAPKs activation. However, ER stressors could block NF-κB binding to the iNOS promoter in late-phase signaling evoked by LPS. Results indicated that inhibition of RelB nuclear translocation and p300 expression are involved in the anti-inflammatory actions of ER stressors. We also found that ER stressors could block LPS- and IFN (α, β, and γ)-mediated STAT1 phosphorylation. Our results suggest that activation of MKP-1 via a Ca/calmodulin/calcineurin pathway accounts for the inhibitory effect of ER stressors on IFN signaling. MKP-1 was downregulated by IFN-γ and is a newly identified protein phosphatase targeting STAT1. Taken together, these results indicate that multiple mechanisms are involved in the inhibition of LPS-induced iNOS gene expression by ER stressors. These include downregulation of RelB and p300, upregulation of MKP-1, and inhibition of the JAK/STAT signaling pathway.     

Testing the impact of calibration on molecular divergence times using a fossil-rich group: the case of Nothofagus (Fagales)

Although temporal calibration is widely recognized as critical for obtaining accurate divergence-time estimates using molecular dating methods, few studies have evaluated the variation resulting from different calibration strategies. Depending on the information available, researchers have often used primary calibrations from the fossil record or secondary calibrations from previous molecular dating studies. In analyses of flowering plants, primary calibration data can be obtained from macro- and mesofossils (e.g., leaves, flowers, and fruits) or microfossils (e.g., pollen). Fossil data can vary substantially in accuracy and precision, presenting a difficult choice when selecting appropriate calibrations. Here, we test the impact of eight plausible calibration scenarios for Nothofagus (Nothofagaceae, Fagales), a plant genus with a particularly rich and well-studied fossil record. To do so, we reviewed the phylogenetic placement and geochronology of 38 fossil taxa of Nothofagus and other Fagales, and we identified minimum age constraints for up to 18 nodes of the phylogeny of Fagales. Molecular dating analyses were conducted for each scenario using maximum likelihood (RAxML + r8s) and Bayesian (BEAST) approaches on sequence data from six regions of the chloroplast and nuclear genomes. Using either ingroup or outgroup constraints, or both, led to similar age estimates, except near strongly influential calibration nodes. Using "early but risky" fossil constraints in addition to "safe but late" constraints, or using assumptions of vicariance instead of fossil constraints, led to older age estimates. In contrast, using secondary calibration points yielded drastically younger age estimates. This empirical study highlights the critical influence of calibration on molecular dating analyses. Even in a best-case situation, with many thoroughly vetted fossils available, substantial uncertainties can remain in the estimates of divergence times. For example, our estimates for the crown group age of Nothofagus varied from 13 to 113 Ma across our full range of calibration scenarios. We suggest that increased background research should be made at all stages of the calibration process to reduce errors wherever possible, from verifying the geochronological data on the fossils to critical reassessment of their phylogenetic position.     

Sequence polymorphisms of Der f 1, Der p 1, Der f 2 and Der p 2 from Korean house dust mite isolates

Amino acid sequence variations have possible influences on the allergenicity of allergens and may be important factors in allergen standardization. This study was undertaken to investigate the sequence polymorphisms of group 1 and 2 allergens from Korean isolates of the house dust mites Dermatophagoides farinae and D. pteronyssinus. cDNA sequences encoding group 1 and 2 allergens were amplified by RT-PCR and compared the deduced amino acid sequences. Der f 1.0101, which appeared in 64.0 % of the 50 sequences analyzed, was found to be predominant. Among the Der p 1 sequences, Der p 1.0102 and 1.0105 were predominant (58 %). Among the Der f 2 sequences, Der f 2.0102 (40.7 %) and a new variant with Gly at position 42 (27.8 %) were predominant. The deduced amino acid sequences of 60 Der p 2 clones were examined, and 28 variants with 1-5 amino acid substitutions were found. Interestingly, all of the Der p 2 sequences had Thr instead of Lys at position 49. Two variants (Leu40, Thr49, and Asn114 (26.6 %); Val40, Thr49, and Asn114 (20.0 %)) were found to be the most predominant forms of Der p 2. Der p 1 has a high rate of sporadic substitutions and the group 2 allergens show a more regular pattern with orderly associations of amino acid substitutions. Der f 1 and Der p 2 from Korean mite isolates have unique amino acid sequence polymorphisms. These findings provide important data for house dust mite allergen standardization.