Effect of diuretic use on 30-day postdialysis mortality in critically ill patients receiving acute dialysis

Background

The impact of diuretic usage and dosage on the mortality of critically ill patients with acute kidney injury is still unclear.

Methods and Results

In this prospective, multicenter, observational study, 572 patients with postsurgical acute kidney injury receiving hemodialysis were recruited and followed daily. Thirty-day postdialysis mortality was analyzed using Cox''s proportional hazards model with time-dependent covariates. The mean age of the 572 patients was 60.8±16.6 years. Patients with lower serum creatinine (p = 0.031) and blood lactate (p = 0.033) at ICU admission, lower predialysis urine output (p = 0.001) and PaO₂/FiO₂ (p = 0.039), as well as diabetes (p = 0.037) and heart failure (p = 0.049) were more likely to receive diuretics. A total of 280 (49.0%) patients died within 30 days after acute dialysis initiation. The analysis of 30-day postdialysis mortality by fitting propensity score-adjusted Cox''s proportional hazards models with time-dependent covariates showed that higher 3-day accumulated diuretic doses after dialysis initiation (HR = 1.449, p = 0.021) could increase the hazard rate of death. Moreover, higher time-varying 3-day accumulative diuretic doses were associated with hypotension (p<0.001) and less intense hemodialysis (p<0.001) during the acute dialysis period.

Background and Significance

Higher time-varying 3-day accumulative diuretic dose predicts mortality in postsurgical critically ill patients requiring acute dialysis. Higher diuretic doses are associated with hypotension and a lower intensity of dialysis. Caution should be employed before loop diuretics are administered to postsurgical patients during the acute dialysis period.     

Distinct neural activity associated with focused-attention meditation and loving-kindness meditation

This study examined the dissociable neural effects of ānāpānasati (focused-attention meditation, FAM) and mettā (loving-kindness meditation, LKM) on BOLD signals during cognitive (continuous performance test, CPT) and affective (emotion-processing task, EPT, in which participants viewed affective pictures) processing. Twenty-two male Chinese expert meditators (11 FAM experts, 11 LKM experts) and 22 male Chinese novice meditators (11 FAM novices, 11 LKM novices) had their brain activity monitored by a 3T MRI scanner while performing the cognitive and affective tasks in both meditation and baseline states. We examined the interaction between state (meditation vs. baseline) and expertise (expert vs. novice) separately during LKM and FAM, using a conjunction approach to reveal common regions sensitive to the expert meditative state. Additionally, exclusive masking techniques revealed distinct interactions between state and group during LKM and FAM. Specifically, we demonstrated that the practice of FAM was associated with expertise-related behavioral improvements and neural activation differences in attention task performance. However, the effect of state LKM meditation did not carry over to attention task performance. On the other hand, both FAM and LKM practice appeared to affect the neural responses to affective pictures. For viewing sad faces, the regions activated for FAM practitioners were consistent with attention-related processing; whereas responses of LKM experts to sad pictures were more in line with differentiating emotional contagion from compassion/emotional regulation processes. Our findings provide the first report of distinct neural activity associated with forms of meditation during sustained attention and emotion processing.     

Developmental changes and regional localization of Dspp, Mepe, Mimecan and Versican in postnatal developing mouse teeth

It has been implicated noncollagenous proteins act as important regulators during odontogenesis. To test the hypothesis that the roles of Dspp, Mepe, Versican and Mimecan in the regulation of odontogenesis may be complementary, comparative investigations on the localization of four proteins were performed by immunohistochemical staining using mouse first molar at different developmental stages as a model. In postnatal 1- day-old mice, all the proteins, excluding Mepe, showed co-expression in young odontoblasts. At postnatal 3, strong immunoreactions for all proteins were detected in odontoblasts. Interestingly, Mepe was present within both cytoplasm and nucleus in odontoblasts. In mice older than 5 days, the expression of Dspp, Mimecan and Versican accumulated in subodontoblastic layer of the coronal pulp at high levels while the co-expression of Mepe and Mimecan significantly existed in predentin. The temporal-spatial specific pattern and unique co-localization of Dspp, Mepe, Mimecan and Versican suggest they play complementary roles during odontogenesis.     

Two species of Lirula on Abies from Yunnan, Southwest China

Based on a recent investigation of species of the Rhytismatales in the eastern Himalayas in China, two species of Lirula on Abies were found, one of which is described as a new species, Lirula yunnanensis, which differs from Lirula japonica mainly by ascomatal structure and conidiomatal features, while the other is Lirula exigua, a new record for China. An analysis of the combined sequences of ITS + LSU r DNA showed that Lirula macrospora and Lophodermium piceae were closely related and that Lirula yunnanensis and Lophodermium autumnale were grouped together. The genus of Lirula should be redefined based on more molecular data. Lirula exigua was distantly related to Lirula species and its systematic position has to be confirmed by further molecular data. A key for known species of Lirula worldwide is provided.     

Feasibility and Safety of Transthoracic Echocardiography-Guided Transcatheter Closure of Atrial Septal Defects with Deficient Superior-Anterior Rims

Although previous studies showed that transthoracic echocardiography (TTE) can be used to guide transcatheter closure of atrial septal defect (ASD), whether TTE can be used to guide transcatheter closure of secundum ASD with a deficient superior-anterior rim is unknown and this critical issue was addressed in the present study. A total of 280 patients with secundum ASD who underwent transcatheter ASD closure were recruited and divided into groups A and B depending on ASD superior-anterior rim>4 mm (n = 118) or ≤4 mm (n = 162). TTE was used to guide Amplatzer-type septal occluder (ASO) positioning and assess residual shunt. Procedure success was defined as no, trivial and small residual shunt immediately after the procedure as assessed by color Doppler flow imaging. Group A and group B did not differ in complication rate (8.55% vs.7.55%), procedure success rate (98.3% vs. 95.0%) or complete closure rate immediately after the procedure (89.7% vs. 89.3%) or at 6-month follow-up (98.3% vs. 96.8%). The mean procedure and fluoroscopy time in group B were much longer than those in group A. In conclusion, the absence of a sufficient superior-anterior rim in patients undergoing percutaneous closure of secundum-type ASDs using fluoroscopic and TTE guidance is associated with slightly greater device malposition and migration as well as increased procedural and fluoroscopic times, but the overall complication rate did not differ with TTE guidance when compared to historical controls that used TEE guidance.     

Molecular basis of recognition of human osteopontin by 23C3, a potential therapeutic antibody for treatment of rheumatoid arthritis

Osteopontin plays an important role in the development and perpetuation of rheumatoid arthritis (RA). Antibodies targeting osteopontin have shown promising therapeutic benefits against this disease. We have previously reported a novel anti-RA monoclonal antibody, namely, 23C3, and shown it capable of alleviating the symptoms of RA in a murine collagen-induced arthritis model, restoring the cytokine production profile in joint tissues, and reducing T-cell recall responses to collagen type II. We describe here the crystal structure of 23C3 in complex with its epitope peptide. Analyses of the complex structure reveal the molecular mechanism of osteopontin recognition by 23C3. The peptide folds into two tandem β-turns, and two key residues of the peptide are identified to be critical for the recognition by 23C3: TrpP43 is deeply embedded into a hydrophobic pocket formed by AlaL34, TyrL36, LeuL46, TyrL49, PheL91, and MetH102 and therefore has extensive hydrophobic interactions with 23C3, while AspP47 has a network of hydrophilic interactions with residues ArgH50, ArgH52, SerH53, and AsnH56 of the antibody. Besides the complementarity-determining region loops, the framework region L2 of 23C3 is also shown to interact with the epitope peptide, which is not common in the antibody-antigen interactions and thus could be exploited in the engineering of 23C3. These results not only provide valuable information for further improvement of 23C3 such as chimerization or humanization for its therapeutic application, but also reveal the features of this specific epitope of osteopontin that may be useful for the development of new antibody drugs against RA.     

MORPHOLOGICAL AND GENETIC VARIATION IN THE POPULATIONS OF SARGASSUM HEMIPHYLLUM (PHAEOPHYCEAE) IN THE NORTHWESTERN PACIFIC1

Difficulty in species identification of Sargassum (Sargassaceae, Fucales) is partly attributed to the high polymorphism among its individuals and populations. This study aimed at assessing morphological and genetic variations in two varieties, var. hemiphyllum J. Agardh and var. chinense J. Agardh, of Sargassum hemiphyllum (Turner) C. Agardh, a widely distributed species in the northwestern Pacific. We investigated 26 measurable, five numerical, and 33 categorical morphological parameters associated with different branching levels of specimens from each of six localities within its distribution range using cluster analysis (CA) and principal coordinate analysis (PCoA). Leaf size of the primary and secondary branching levels and the vesicle size of the secondary branches of the specimens examined were determined to be the most important morphological parameters that were significantly different among populations. Change in leaf and vesicle length of individuals among the six populations followed a latitudinal gradient, with smaller leaves and vesicles associated with northern populations and larger ones in the southern populations. The possible influence of the gradual change in sea surface temperatures (SSTs) along this gradient in the northwestern Pacific on leaf and vesicle morphologies of this species was suggested. PCR‐RFLP analysis of the RUBISCO spacer in the chloroplast genome revealed two distinct and highly homogenous clades, a China clade and a Japan‐Korea clade, which corresponded to var. chinense and var. hemiphyllum, respectively. The formation of refugia along the “Paleo‐coast” in the East China Sea during glacial periods is suggested to have led to the vicariance of ancestral populations of S. hemiphyllum and thus to have promoted genetic differentiation. The massive freshwater outflow of the Yellow and Yangtze rivers may continue to act as a barrier, prolonging the allopatric distribution of the two varieties.     

Phosphomimetic mutations increase phospholamban oligomerization and alter the structure of its regulatory complex

To investigate the effect of phosphorylation on the interactions of phospholamban (PLB) with itself and its regulatory target, SERCA, we measured FRET from CFP-SERCA or CFP-PLB to YFP-PLB in live AAV-293 cells. Phosphorylation of PLB was mimicked by mutations S16E (PKA site) or S16E/T17E (PKA+CaMKII sites). FRET increased with protein concentration up to a maximum (FRET(max)) that was taken to represent the intrinsic FRET of the bound complex. The concentration dependence of FRET yielded dissociation constants (K(D)) for the PLB-PLB and PLB-SERCA interactions. PLB-PLB FRET data suggest pseudo-phosphorylation of PLB increased oligomerization of PLB but did not alter PLB pentamer quaternary structure. PLB-SERCA FRET experiments showed an apparent decrease in binding of PLB to SERCA and an increase in the apparent PLB-SERCA binding cooperativity. It is likely that these changes are secondary effects of increased oligomerization of PLB; a change in the inherent affinity of monomeric PLB for SERCA was not detected. In addition, PLB-SERCA complex FRET(max) was reduced by phosphomimetic mutations, suggesting the conformation of the regulatory complex is significantly altered by PLB phosphorylation.