Association between serum methylmalonic acid and chronic kidney disease in adults: a cross-sectional study from NHANES 2013-2014.

Introduction: Chronic kidney disease(CKD) is a global medical problem. Serum methylmalonic acid(MMA) is a serum marker associated with many diseases. This study aimed to investigate the association between MMA and CKD. Methods: Data from the National Health and Nutrition Examination Survey (NHANES) 2013-2014 were downloaded and analyzed. The association between MMA and CKD was confirmed by using multiple logistic regression modeling. The smooth curve fitting method was used to investigate the nonlinear relationship between them. Subgroup analyses and interaction tests were used to verify the stability of the association between different subgroups. Threshold effect analysis was used to determine the optimal control point for MMA. Results: There was a unique W-shaped nonlinear relationship between MMA and the risk of CKD, with a positive correlation between them (OR=1.66,95% CI:1.27, 2.17; P=0.0002). As the stage of CKD progressed, MMA levels increased. Age, hypertension, and serum vitamin B12 had significant influences on the association between MMA and the risk of CKD. Conclusion: Our findings revealed that serum MMA accumulation was positively associated with the risk of CKD. Serum MMA level may be a novel index to predict the development and course of CKD. This study may help in the early identification of people at risk for chronic kidney disease and provide new ideas and approaches for prevention and treatment.

Association between serum Klotho and major depression: Results from the NHANES 2007-2016 and Mendelian randomization studies.

BACKGROUND: Major depression is a public health problem facing the world. This study aimed to identify the risk factors for major depression and clarify their causal effects. METHODS: Data from the National Health and Nutrition Examination Survey (NHANES). Multifactorial logistic regression analysis was used to calculate the effect of each variable on major depression. Subgroup analyses and interaction tests were conducted to observe the stability of the association between them. Nonlinear correlations were explored using restricted cubic spline plots. The causal effects of serum Klotho on major depression were assessed using Mendelian randomization (MR) analysis. RESULTS: A total of 8359 participated in the study. After adjusting for all covariates, the risk of having major depression was 1.47 times higher for each unit rise in serum Klotho (OR = 1.47, 95 % CI = 1.07-2.02; P = 0.0183). MR analysis showed no causal relationship between serum Klotho levels and risk of major depression (OR = 1.09, 95 % CI = 0.91-1.30; P = 0.4120). Sensitivity analysis verified the reliability of the results. CONCLUSIONS: Serum Klotho is positively associated with an increased risk of major depression in the U.S. population, but MR analyses did not show genetic causality between Klotho and major depression in individuals of European ancestry. Based on the results of the current study, no indication maintaining high levels of Klotho may increase the risk of major depression. LIMITATIONS: The main limitation of this study is the inconsistency of the cross-sectional study and the MR population.

Low Expression of GRIM-19 Correlates with Poor Prognosis in Patients with Upper Urinary Tract Urothelial Carcinoma.

PURPOSE: This study aimed to clarify the expression of a gene associated with Retinoid- Interferon-Induced Mortality-19 (GRIM-19) in Upper Urinary Tract Urothelial Carcinoma (UUTUC) and its prognostic significance for UUTUC patients. MATERIALS AND METHODS: Immunohistochemical (IHC) staining was used to determine the GRIM-19 expression in 70 paired samples. Progression-Free Survival (PFS) and Cancer-Specific Survival (CSS) were assessed using the Kaplan-Meier method. The independent prognostic factors for PFS and CSS were analyzed by multivariable Cox regression models. RESULTS: IHC staining showed that GRIM-19 expression was significantly decreased in UUTUC, and its cellular location changed from being both cytoplasmic and nuclear to only cytoplasmic. Kaplan- Meier analysis revealed that the patients with tumors expressing low GRIM-19 had a significantly higher risk for tumor progression (P = 0.002) and cancer-specific mortality (P < 0.001) compared to those with high GRIM-19 levels. The Cox regression showed that both GRIM-19 expression (P = 0.025) and lymph node metastasis (LN) (P = 0.007) were independent predictors of progression in the muscle-invasive (MIC) subgroup. GRIM-19 expressions (entire cohort: P = 0.011; MIC subgroup: P = 0.025), LN (entire cohort: P = 0.019; MIC subgroup: P = 0.007), and progression (entire cohort: P < 0.001; MIC subgroup: P < 0.001) were independent predictors of cancer-specific survival. CONCLUSION: Low expression of GRIM-19 in patients with UUTUC had significantly shorter PFS or CSS compared to those with high GRIM-19-expressing tumors. High GRIM-19 expression was also strongly associated with longer PFS in MIC patients. It indicates that GRIM-19 might serve as a promising prognostic biomarker for UUTUC patients.

Dual Spatially Localized DNA Walker for Fast and Efficient RNA Detection.

DNA walkers, which are synthetic nanodevices that drive the processive movement of nucleic acids along a well-designed track, have emerged as a powerful tool in biosynthesis, biocomputing, and biosensing due to their exquisite programmability, good biocompatibility, and efficient signal amplification capacity. However, many existing approaches are still hindered by limited reaction kinetics. Herein, we designed a dual spatially localized DNA walker that utilized bipedal catalysts to drive high-speed stochastic movement along three-dimensional tracks via a proximity-driven catalytic hairpin assembly. We demonstrated that the dual colocalization of autocatalytic circuits significantly increased their local concentrations and accelerated reaction kinetics through proximity. We also showed that the use of bipedal catalysts further improved reaction rates compared with unipedal catalysts. Taking advantage of these unique features, we constructed an RNA-responsive PCHA walker for mRNA imaging in live cells, providing a novel and efficient tool for biomolecule detection and biological functions regulation.

Effects of Fumed Silica on Thixotropic Behavior and Processing Window by UV-Assisted Direct Ink Writing.

In this research, the effects of fumed silica (FS) on the Ultraviolet (UV)-ink rheological behavior and processing windows were discussed. Objects using different concentrations of FS inks were printed by the modified UV-Direct ink writing (DIW) printer. The function of fumed silica in the ink-based system has been verified, and the processing scope has been expended with a suitable amount of FS combined with the UV light. The results show that the combination of a suitable amount of FS with the UV-DIW system reaches fast and accurate printing with a larger processing window compared to the non-UV system. However, an excessively high concentration of FS will increase the yield stress of the ink, which also increases the requirement of extrusion unit and the die-swelling effects.

Gnas Promoter Hypermethylation in the Basolateral Amygdala Regulates Reconsolidation of Morphine Reward Memory in Rats.

Impairing reconsolidation may disrupt drug memories to prevent relapse, meanwhile long-term transcription regulations in the brain regions contribute to the occurrence of emotional memories. The basolateral amygdala (BLA) is involved in the drug-cue association, while the nucleus accumbens (NAc) responds to the drug reward. Here, we assessed whether DNA methyltransferases (Dnmts) in these two brain regions function identically in the reconsolidation of morphine reward memory. We show that Dnmts inhibition in the BLA but not in the NAc after memory retrieval impaired reconsolidation of a morphine reward memory. Moreover, the mRNA levels of Dnmt3a and Dnmt3b, rather than Dnmt1, in the BLA were continuously upregulated after retrieval. We further identified the differentially methylated regions (DMRs) in genes in the BLA after retrieval, and focused on the DMRs located in gene promoter regions. Among them were three genes (Gnas, Sox10, and Pik3r1) involved in memory modulation. Furthermore, Gnas promoter hypermethylation was confirmed to be inversely correlated with the downregulation of Gnas mRNA levels. The findings indicate that the specific transcription regulation mechanism in the BLA and NAc on reconsolidation of opiate-associated memories can be dissociable, and DNA hypermethylation of Gnas in the BLA is necessary for the reconsolidation of morphine reward memories.

Concentration of Microparticles Using Flexural Acoustic Wave in Sessile Droplets.

Acoustic manipulation of microparticles and cells has attracted growing interest in biomedical applications. In particular, the use of acoustic waves to concentrate particles plays an important role in enhancing the detection process by biosensors. Here, we demonstrated microparticle concentration within sessile droplets placed on the hydrophobic surface using the flexural wave. The design benefits from streaming flow induced by the Lamb wave propagated in the glass waveguide to manipulate particles in the droplets. Microparticles will be concentrated at the central area of the droplet adhesion plane based on the balance among the streaming drag force, gravity, and buoyancy at the operating frequency. We experimentally demonstrated the concentration of particles of various sizes and tumor cells. Using numerical simulation, we predicted the acoustic pressure and streaming flow pattern within the droplet and characterized the underlying physical mechanisms for particle motion. The design is more suitable for micron-sized particle preparation, and it can be valuable for various biological, chemical, and medical applications.

Analysis of UV Curing Strategy on Reaction Heat Control and Part Accuracy for Additive Manufacturing.

In this research, the relationship between the curing strategies and geometrical accuracy of parts under UV light was investigated. An IR camera was utilized to monitor the process using different combinations of photosensitive resin and curing strategies. The influences of curing strategies on different material compositions were studied with single-factor analysis. With the different exposure frequencies of the UV light, the peak temperature was adjusted to avoid overheating. The three-dimensional geometry of casting tensile bars was measured to investigate the shrinkage and warpage during the curing process. Different material compositions were also selected to study the effects of the maximum temperature on the shrinkage of the parts. The findings of this work show that, with the same amount of energy input, a more fragmented exposure allows for a more controllable max temperature, while one-time exposure leads to a high temperature during the process. With the decrease of the released heat from the reaction, the shrinkage of the casting part has a slightly increasing tendency. Moreover, the warpage of the parts decreased drastically with the decrease of temperature. The addition of fillers enhances the control over temperature and increases the geometrical accuracy.

New Considerations on the Determination of the Apparent Shear Viscosity of Polymer Melt with Micro Capillary Dies.

Capillary rheometers have been widely used for the rheological measurement of polymer melts. However, when micro capillary dies are used, the results are usually neither accurate nor consistent, even under the same measurement conditions. In this work, theoretical modeling and experimental studies were conducted for a more profound understanding of the mechanism by which the initial and boundary conditions influence the inaccuracy in the apparent shear viscosity determination with micro capillary dies (diameters: 500 µm, 200 µm, 100 µm). The results indicate that the amount of polymer initially in the barrel, the pre-compaction pressure and the capillary die diameter have a significant influence on the development of the micro scale inlet pressure, which directly determines the accuracy of the measurement at low and medium shear rates. The varying melt compressibility was confirmed to be the main factor directly related to the inaccuracy in the micro scale apparent shear viscosity determination. It is suggested that measures such as reducing the amount of polymer initially in the barrel and increasing the pre-compaction pressure could be used to reduce the measurement inaccuracy.

Rapid Enrichment of Submicron Particles within a Spinning Droplet Driven by a Unidirectional Acoustic Transducer.

Efficient and rapid particle enrichment at the submicron scale is essential for research in biomedicine and biochemistry. Here, we demonstrate an acoustofluidic method for submicron particle enrichment within a spinning droplet driven by a unidirectional transducer. The unidirectional transducer generates intense sound energy with relatively low attenuation. Droplets placed offset in the wave propagation path on a polydimethylsiloxane film undergo strong pressure gradients, deforming into an ellipsoid shape and spinning at high speed. Benefitting from the drag force induced by the droplet spin and acoustic streaming and the radial force induced by the droplet compression and expansion, the submicron particles in the liquid droplet quickly enrich toward the central area following a spiral trajectory. Through numerical calculations and experimental processes, we have demonstrated the possible mechanism responsible for particle enrichment. The application of biological sample processing has also been exploited. This study anticipates that the strategy based on the spinning droplet and particle enrichment method will be highly desirable for many applications.

Double dissociation of inhibitory effects between the hippocampal TET1 and TET3 in the acquisition of morphine self-administration in rats.

The development of opioid addiction involves DNA methylation. Accordingly, the DNA demethylation, induced by ten-eleven translocation (Tet) enzymes, may represent a novel approach to prevent opioid addiction. The present study examined the role of TET1 and TET3 in the development of morphine-seeking behavior in rats. We showed that 1 day of morphine self-administration (SA) training upregulated TET3 but not TET1 expression in the hippocampal CA1. With 7 days of morphine SA training, the expression of TET3 in the CA1 returned to the baseline level, while the TET1 expression was downregulated. No change of TET1 and TET3 in the nucleus accumbens shell was observed in morphine SA trained rats, or in the yoked morphine rats, or in rats trained for saccharin SA. Furthermore, we found that knocking down TET3 expression in the CA1 accelerated the acquisition of morphine SA, while overexpression of the catalytic domain of TET1 in the CA1 attenuated the acquisition. Together, these findings suggest that TET1 and TET3 in the CA1 are important epigenetic modulators involved in the morphine-seeking behavior and provide a new strategy in the treatment of opioid addiction.

Atomistic Investigation on the Wetting Behavior and Interfacial Joining of Polymer-Metal Interface.

Polymer-metal hybrid structures can reduce the weight of components while ensuring the structural strength, which in turn save cost and subsequently fuel consumption. The interface strength of polymer-metal hybrid structure is mainly determined by the synergistic effects of interfacial interaction and mechanical interlocking. In this study, the wetting behavior of polypropylene (PP) melt on metal surface was studied by molecular dynamics simulation. Atomistic models with smooth surface and nano-column arrays on Al substrate were constructed. Influences of melt temperature, surface roughness and metal material on the wetting behavior and interfacial joining were analyzed. Afterwards the separation process of injection-molded PP-metal hybrid structure was simulated to analyze joining strength. Results show that the initially sphere-like PP model gradually collapses in the wetting simulation. With a higher temperature, it is easier for molecule chains to spread along the surface. For substrate with rough surface, high density is observed at the bottom or on the upper surface of the column. The contact state is transitioning from Wenzel state to Cassie-Baxter state with the decrease of void fraction. The inner force of injection-molded PP-Fe hybrid structure during the separation process is obviously higher, demonstrating a greater joining strength.

Curing Kinetic Analysis of Acrylate Photopolymer for Additive Manufacturing by Photo-DSC.

In this research, the curing degree of an acrylate-based monomer using direct UV-assisted writing technology was characterized by differential photo calorimetry (Photo-DSC) to investigate the curing behavior. Triggered by the UV light, the duo function group monomer 1,6-Hexamethylene diacrylate (HDDA), photoinitiator 1173 and photoinhibitor exhibit a fast curing process. The exothermal photopolymerization reaction was performed in the isothermal mode in order to evaluate the different thermal effects that occurred during the photopolymerization process. The influences of both UV light intensity and exposure time were studied with single-factor analysis. The results obtained by photo-DSC also allow us to perform the kinetic study of the polymerization process: The results show that, for the reaction, the higher the UV intensity, the higher the curing degree together with faster curing speed. At the same time, the effect of the heat released during the exothermic reaction is negligible for the polymerization process. When increasing the exposure time, limited improvement of curing degree was shown, and the distribution is between 65-75%. The reaction enthalpy and related curing degree work as a function of time. The Avrami theory of phase change was introduced to describe the experimental data. The functions of a curing degree with light intensity and exposure time were achieved, respectively.

Application of metallic ureteral stents in gynecological malignancies: a literature review.

Ureteral obstruction caused by extrinsic compression from advanced pelvic malignancies are not unusual in urology, with gynecological origin being the most common. As minimally invasive treatments for malignant ureteral obstruction (MUO), metallic ureteral stents have been promoted to provide long-lasting urinary patency and overcome the inherent limits of traditional double-J stents. In this review, we demonstrated three types of frequently used metal stents, including coiled stents, self-expendable stents and thermo-expendable stents. The Wallstent presented discrepant patency rates ranging from 6% to 100%, along with a high occlusion rate. The Memokath 051 stent showed satisfactory patency rates, often > 90%, but also a specific higher migration rate. The Resonance stent provided overall promising results with published success rates ranging from 20% to 100%, which on the whole remains relatively high. The long-term effectiveness rendered metal stents as viable options for managing MUO.

DNMT3a in the hippocampal CA1 is crucial in the acquisition of morphine self-administration in rats.

Drug-reinforced excessive operant responding is one fundamental feature of long-lasting addiction-like behaviors and relapse in animals. However, the transcriptional regulatory mechanisms responsible for the persistent drug-specific (not natural rewards) operant behavior are not entirely clear. In this study, we demonstrate a key role for one of the de novo DNA methyltransferase, DNMT3a, in the acquisition of morphine self-administration (SA) in rats. The expression of DNMT3a in the hippocampal CA1 region but not in the nucleus accumbens shell was significantly up-regulated after 1- and 7-day morphine SA (0.3 mg/kg/infusion) but not after the yoked morphine injection. On the other hand, saccharin SA did not affect the expression of DNMT3a or DNMT3b. DNMT inhibitor 5-aza-2-deoxycytidine (5-aza) microinjected into the hippocampal CA1 significantly attenuated the acquisition of morphine SA. Knockdown of DNMT3a also impaired the ability to acquire the morphine SA. Overall, these findings suggest that DNMT3a in the hippocampus plays an important role in the acquisition of morphine SA and may be a valid target to prevent the development of morphine addiction.

LncRNA SAMMSON overexpression distinguished glioblastoma patients from patients with diffuse neurosarcoidosis.

The MRI characteristics of diffuse neurosarcoidosis are similar to those of glioblastoma. Therefore, identification of novel biomarkers to distinguish these two diseases is needed. We found that lncRNA Survival Associated Mitochondrial Melanoma-Specific Oncogenic Non-Coding RNA (SAMMSON) was upregulated in plasma of glioblastoma patients but not in diffuse neurosarcoidosis patients comparing to healthy controls. Upregulated SAMMSON distinguished glioblastoma patients from diffuse neurosarcoidosis patients and healthy controls. MiR-622 in glioblastoma patients was inversely correlated with SAMMSON. SAMMSON overexpression caused the downregulated expression of miR-622 in glioblastoma cells, while miR-622 overexpression did not affect SAMMSON expression. SAMMSON overexpression mediated the increased proliferation rate of glioblastoma cells. MiR-622 overexpression played an opposite role and reduced the effects of SAMMSON overexpression. Therefore, plasma SAMMSON has diagnostic value for glioblastoma and SAMMSON overexpression may promote glioblastoma cell proliferation by downregulating miR-622.

Molecular Characterization and Expression of Vitellogenin and Vitellogenin Receptor of Thitarodes pui (Lepidoptera: Hepialidae), an Insect on the Tibetan Plateau.

Vitellogenin (Vg) and vitellogenin receptor (VgR) play important roles in the vitellogenesis of insects. In this study, we cloned and characterized the two corresponding genes (TpVg and TpVgR) in an economically important insect, Thitarodes pui (Lepidoptera: Hepialidae), from the Tibetan plateau. The full length of TpVg is 5566 bp with a 5373 bp open reading frame (ORF) encoding 1,790 amino acids. Sequence alignment revealed that TpVg has three conserved domains: a Vitellogenin_N domain, a DUF1943 domain, and a von Willebrand factor type D domain (VWD). The full length of TpVgR is 5732 bp, with a 5397 bp ORF encoding 1798 amino acids. BLASTP showed that TpVgR belongs to the low-density lipoprotein receptor (LDLR) gene superfamily. Structural analysis revealed that TpVgR has a group of four structural domains: a ligand-binding domain (LBD), an epidermal growth factor (EGF)-precursor homology domain, a transmembrane (TM) domain, and a cytoplasmic domain. In addition, TpVgR has four cysteine-rich LDL repeats in the first ligand-binding site and seven in the second. Quantitative real-time polymerase chain reaction analysis revealed that the expression levels of TpVg and TpVgR are much higher in later pupa than in either the larval or adult stage, implying that the synthesis and uptake of Vg in T. pui occurs in the later pupal stage. These results will help us to understand the molecular mechanism of the reproductive capacity and will provide new insight into the mass rearing and utilization of T. pui.

Application of resonance metallic stents for malignant ureteral obstruction.

Purpose: To determine the effectiveness of the Resonance metallic stent in treating malignant ureteral obstruction (MUO) and clarify the risk factors that lead to stent failure. Material and methods: We retrospectively identified and analyzed the records of patients who had MUO and underwent placement of Resonance metallic stents from November 2014 to June 2017 in our hospital. Stent failure was defined as unexpected interventions including stent exchange, need of percutaneous nephrostomies (PCN) or ureterocutaneostomy. Results: A total of 22 stents were placed in 14 patients with MUO. The median follow-up was 145 days (4.8 months) and the maximum duration of stenting was 21.3 months. The technique success rate was 100%. Two patients experienced early postoperative increasing creatinine with oliguria but only one of them failed to achieve primary patency. The overall success rate was 90% (9/10). Conclusion: Resonance metallic stent is a safe and effective treatment for MUO and can maintain durable patency over 12 months. Preoperative urinary tract infection (UTI) and tumor invasion into the bladder are considered as risk factors of stent blockage and failure. Early postoperative elevated creatinine oliguria, suggestive with intrarenal and prerenal disease, should not be deemed to be stent failure.

Distinctive Changes of L-Type Calcium Channels and Dopamine Receptors in the Dorsomedial and Dorsolateral Striatum after the Expression of Habitual Cocaine-Seeking Behavior in Rats.

Habitual drug-seeking behavior is essential in the transition from recreational drug use to compulsive drug use and is regulated by the dopamine (DA) system of the dorsal striatum (DS). However, a comparative study of the two subtypes of DA receptors, D1 receptors (D1R) and D2 receptors (D2R), which have opposite regulatory functions, in habitual drug-seeking behavior is absent. Moreover, the effects of L-type calcium channels (LTCCs) and the subtypes Cav1.2 and Cav1.3, which are downstream of D1R and D2R, respectively, on habitual drug-seeking behavior have yet to be revealed. Therefore, based on the establishment of habitual cocaine-seeking behavior with changeable fixed interval (FI) self-administration (SA) training in rats, we compared the distinctive changes in D1R vs. D2R and Cav1.2 vs. Cav1.3 in the expression of habitual cocaine-seeking behavior in the dorsomedial striatum (DMS) and dorsolateral striatum (DLS). Our results showed that approximately forty percent of the animals exhibited habitual behavior after cocaine SA training. In addition, the total and membrane Cav1.2 and D1R in the DLS demonstrated higher expression, but the total and membrane Cav1.3 and D2R in the DMS demonstrated lower expression in well-established cocaine habitual behavior animals compared with non-established habitual behavior animals. These results suggested that upregulation of D1R-Cav1.2 signaling may enhance the function of the DLS and that inactivation of D2R-Cav1.3 caused depressed activity in the DMS during expression of habitual cocaine-seeking behavior. The imbalanced function between the DMS and DLS, which causes a shift from the DMS to the DLS, may mediate habitual behaviors.

Transcriptome characterization and gene expression analysis related to sexual dimorphism in the ghost moth, Thitarodes pui, a host of Ophiocordyceps sinensis.

Thitarodes pui is one of the host species of the Chinese caterpillar fungus Ophiocordyceps sinensis as a traditional Chinese medicine with economic and medical importance. The pupal and adult stages of T. pui are sexually dimorphic. In order to elucidate the molecular mechanisms involved in the sexually dimorphic development of T. pui, we compared the transcriptomes of female and male pupae and adults. We obtained 15,881,734, 16,962,086, 17,514,743, and 17,770,904 clean reads from female pupae, male pupae, female adults, and male adults, respectively. The reads obtained from the four samples were pooled and assembled into 65,165 unigenes, 23,597 of which were annotated. Candidate genes involved in sexual development were identified and analysed. Gene expression analysis revealed that 1406 genes were differentially expressed in male and female pupae, 448 of which were up-regulated in males and 958 were up-regulated in females. A total of 2025 genes were differentially expressed in male and females adults, 1304 of which were up-regulated in males and 721 were up-regulated in females. The functional enrichment of the differentially expressed genes indicated that reproduction and cuticle synthesis were regulated differently between the sexes. The transcriptome data obtained provide significant information regarding the genes involved in sexually dimorphic development, which will improve our understanding of the molecular mechanisms related to sexual dimorphism and helpful for the moth mass rearing which would provide enough host insects for the sustainable utilization of O. sinensis.