Preparation of alkyl microporous organic network-based capillary column for an efficient gas chromatographic separation of position isomers.

The large surface area, excellent thermal stability and easy modification make microporous organic networks (MONs) good candidates in the field of gas chromatography (GC). Due to the limited species and highly conjugated networks of MONs, their applications are still in infancy and restricted. To accelerate their developments and to enrich their types in GC, here we report the first example of synthesizing alkyl MON and its capillary column for GC separation of position isomers. Linear 1,8-dibromooctane is used as the alkyl monomer instead of traditional aromatic ones to construct novel alkyl MON to decrease the inherent conjugated characteristic of MONs. The alkyl MON exhibits good thermal stability (up to 350°C), large surface area (1173 m2 g-1), and non-polar character, allowing good resolution for alkanes, alkyl benzenes, alcohols, ketones, and diverse position isomers, including dichlorobenzene, trichlorobenzene, bromotoluene, nitrotoluene, methylbenzaldehyde, and ionone with the limits of detection (0.003 mg mL-1) and limits of quantitation of (0.10 mg mL-1). The in situ growth-prepared alkyl MON column demonstrates remarkable duration time and precisions for the retention relative standard deviations, (RSDs%, intra-day, n = 7), 0.06%-0.53% (intra-day, n = 7), and 2.87%-10.59% (column-to-column, n = 3). In addition, the fabricated alkyl MON-coated capillary column offers better resolution than three commercial GC columns for the resolution of methylbenzaldehyde, bromotoluene, and chlorotoluene isomers. This work reveals the practicability for synthesizing alkyl MONs and demonstrates their prospects for position isomers separation.

A comparative study of microbial changes in dental plaque before and after single- and multiappointment treatments in patients with severe early childhood caries.

BACKGROUND: The status of dental caries is closely related to changes in the oral microbiome. In this study, we compared the diversity and structure of the dental plaque microbiome in children with severe early childhood caries (S-ECC) before and after general anaesthesia and outpatient treatment. METHODS: Forty children aged 3 to 5 years with S-ECC who had completed whole-mouth dental treatment under general anaesthesia (C1) or in outpatient settings (C2) were selected, 20 in each group. The basic information and oral health status of the children were recorded, and the microbial community structure and diversity of dental plaque before treatment (C1, C2), the day after treatment(C2_0D), 7 days after treatment (C1_7D, C2_7D), 1 month after treatment (C1_1M, C2_1M), and 3 months after treatment (C1_3M, C2_3M) were analysed via 16 S rRNA high-throughput sequencing technology. RESULTS: (1) The alpha diversity test showed that the flora richness in the multiappointment group was significantly greater at posttreatment than at pretreatment (P < 0.05), and the remaining alpha diversity index did not significantly differ between the 2 groups (P > 0.05). The beta diversity analysis revealed that the flora structures of the C1_7D group and the C2_3M group were significantly different from those of the other time points within the respective groups (P < 0.05). (2) The core flora existed in both the pre- and posttreatment groups, and the proportion of their flora abundance could be altered depending on the caries status of the children in both groups. Leptotrichia abundance was significantly (P < 0.05) lower at 7 days posttreatment in both the single- and multiappointment groups. Corynebacterium and Corynebacterium_matruchotii were significantly more abundant in the C1_1M and C1_3M groups than in the C1 and C1_7D groups (P < 0.05). Streptococcus, Haemophilus and Haemophilus_parainfluenzae were significantly more abundant in the C1_7D group than in the other groups (P < 0.05). CONCLUSION: A single session of treatment under general anaesthesia can cause dramatic changes in the microbial community structure and composition within 7 days after treatment, whereas treatment over multiple appointments may cause slow changes in oral flora diversity.

Rearrangement of 2-(benzofuran-2-yl)-3-phenylpyridines via photoinduced 6π-electrocyclization.

By photoinduced 6π-electrocyclization of 2-(benzofuran-2-yl)-3-phenylpyridine derivatives 1, a method for the synthesis of trans-dihydrobenzo[f]quinolines 2, cis-dihydrobenzo[f]quinolines 3 and 8b-methyl-1,8b-dihydrobenzo[f]quinolines 4 was developed. Irradiation of 2-(benzofuran-2-yl)-3-phenylpyridine 1 in acetone-H2O (5 : 1, v/v) with a 313 nm UV lamp under an argon atmosphere at room temperature successfully yielded 2, which was further converted into 3 at elevated temperature (200 °C) in glycerol. However, irradiating 2-(3-methylbenzofuran-2-yl)-3-phenylpyridines 1 in CH2Cl2 with a 254 nm UV lamp gave 4 in good yields. The syntheses of 2, 3 and 4via the 6π-electrocyclization rearrangement of 1 not only offer high atom efficiency but also do not require transition metal catalysts or additives.

Dietary Galactooligosaccharides Supplementation as a Gut Microbiota-Regulating Approach to Lower Early Life Arsenic Exposure.

Prebiotics may stimulate beneficial gut microorganisms. However, it remains unclear whether they can lower the oral bioavailability of early life arsenic (As) exposure via regulating gut microbiota and altering As biotransformation along the gastrointestinal (GI) tract. In this study, weanling mice were exposed to arsenate (iAsV) via diet (7.5 µg As g-1) amended with fructooligosaccharides (FOS), galactooligosaccharides (GOS), and inulin individually at 1% and 5% (w/w). Compared to As exposure control mice, As concentrations in mouse blood, liver, and kidneys and As urinary excretion factor (UEF) were reduced by 43.7%-74.1% when treated with 5% GOS. The decrease corresponded to a significant proliferation of Akkermansia and Psychrobacter, reduced percentage of inorganic arsenite (iAsIII) and iAsV by 47.4% and 65.4%, and increased proportion of DMAV in intestinal contents by 101% in the guts of mice treated with 5% GOS compared to the As control group. In contrast, FOS and inulin either at l% or 5% did not reduce As concentration in mouse blood, liver, and kidneys or As UEF. These results suggest that GOS supplementation may be a gut microbiota-regulating approach to lower early life As exposure via stimulating the growth of Akkermansia and Psychrobacter and enhancing As methylation in the GI tract.

Quantitative Insights into a Plasmonic Ruler Equation from the Perspective of Enhanced Near Field.

The plasmonic shift of resonance wavelength induced by near-field coupling enables one to measure nanoscale distances optically. Empirically, the well-known ruler equation correlating plasmon shift with interparticle spacing was proposed. Though it has been widely used in analyzing simulation and experimental outcomes, little is known about the underlying physical mechanism of the characteristic exponential form of the plasmon ruler equation and the universal decay constant therein. In this work, we attempt to decrypt these from the perspective of plasmon near-field enhancement. Based on an analytical quasi-normal mode formula for plasmon shifts, we proved that the exponential decaying electric field is the critical reason that results in the exponential form of the plasmon ruler equation and quantitatively, we found that the universal decay constant in the plasmon ruler equation actually reflects the range of the enhanced near field. This work hopefully helps to deepen the understanding of the mechanism of light-matter interaction in corresponding plasmonic processes.

Mutually exclusive substrate selection strategy by human m3C RNA transferases METTL2A and METTL6.

tRNAs harbor the most diverse posttranscriptional modifications. The 3-methylcytidine (m3C) is widely distributed at position C32 (m3C32) of eukaryotic tRNAThr and tRNASer species. m3C32 is decorated by the single methyltransferase Trm140 in budding yeasts; however, two (Trm140 and Trm141 in fission yeasts) or three enzymes (METTL2A, METTL2B and METTL6 in mammals) are involved in its biogenesis. The rationale for the existence of multiple m3C32 methyltransferases and their substrate discrimination mechanism is hitherto unknown. Here, we revealed that both METTL2A and METTL2B are expressed in vivo. We purified human METTL2A, METTL2B, and METTL6 to high homogeneity. We successfully reconstituted m3C32 modification activity for tRNAThr by METT2A and for tRNASer(GCU) by METTL6, assisted by seryl-tRNA synthetase (SerRS) in vitro. Compared with METTL2A, METTL2B exhibited dramatically lower activity in vitro. Both G35 and t6A at position 37 (t6A37) are necessary but insufficient prerequisites for tRNAThr m3C32 formation, while the anticodon loop and the long variable arm, but not t6A37, are key determinants for tRNASer(GCU) m3C32 biogenesis, likely being recognized synergistically by METTL6 and SerRS, respectively. Finally, we proposed a mutually exclusive substrate selection model to ensure correct discrimination among multiple tRNAs by multiple m3C32 methyltransferases.

Profiling the lncRNA-miRNA-mRNA interaction network in the submandibular gland of diabetic mice.

BACKGROUND: Hyposalivation is one of the common symptoms of diabetes. Although long non-coding RNAs (lncRNAs) have recently been reported to play important roles in the pathogenesis of diabetes, the role of lncRNAs in diabetes-induced hyposalivation remains unknown. METHODS: The present study aimed to explore the function of lncRNA-microRNA-mRNA regulatory network in the submandibular gland (SMGs) under the context of diabetes. LncRNA expression profile of the SMGs was analyzed using microarray technology. Differentially expressed lncRNAs were confirmed using real-time quantitative PCR. Bioinformatics analyses were performed, and Coding-non-coding gene co-expression (CNC) and competing endogenous RNA (ceRNA) networks were constructed to explore the potential mechanisms of diabetes-induced hyposalivation. RESULTS: A total of 1273 differentially expressed lncRNAs (536 up-regulated and 737 downregulated) were identified in the SMGs tissues of db/db mice. CNC and ceRNA network analyses were performed based on five differentially expressed lncRNAs validated by real-time quantitative PCR. Gene Ontology analysis of target genes of CNC network revealed that "calcium ion binding" was a highly enriched molecular function. Kyoto Encyclopedia of Genes and Genomes pathway analysis of target genes of ceRNA network revealed that the "mammalian target of rapamycin signaling pathway" was significantly enriched. CONCLUSIONS: On the whole, the findings of the present study may provide insight into the possible mechanism of diabetes-induced hyposalivation.

Novel variants of engineered water soluble mu opioid receptors with extensive mutations and removal of cysteines.

We have shown that water-soluble variants of the human mu opioid receptor (wsMOR) containing a reduced number of hydrophobic residues at the lipid-facing residues of the transmembrane (TM) helices can be expressed in E. coli. In this study, we tested the consequences of increasing the number of mutations on the surface of the transmembrane domain on the receptor's aqueous solubility and ligand binding properties, along with mutation of 11 cysteine residues regardless of their solvent exposure value and location in the protein. We computationally engineered 10 different variants of MOR, and tested four of them for expression in E. coli. We found that all four variants were successfully expressed and could be purified in high quantities. The variants have alpha helical structural content similar to that of the native MOR, and they also display binding affinities for the MOR antagonist (naltrexone) similar to the wsMOR variants we engineered previously that contained many fewer mutations. Furthermore, for these full-length variants, the helical content remains unchanged over a wide range of pH values (pH 6 ~ 9). This study demonstrates the flexibility and robustness of the water-soluble MOR variants with respect to additional designed mutations in the TM domain and changes in pH, whereupon the protein's structural integrity and its ligand binding affinity are maintained. These variants of the full-length MOR with less hydrophobic surface residues and less cysteines can be obtained in large amounts from expression in E. coli and can serve as novel tools to investigate structure-function relationships of the receptor.

Synthesis of 6-phenylbenzo[h]quinolines via photoinduced dehydrogenative annulation of (E)-2-phenyl-3-styrylpyridines.

A concise and environmentally friendly protocol was developed for the synthesis of 6-phenylbenzo[h]quinolines. 6-Phenylbenzo[h]quinolines were obtained in good yields via irradiation of (E)-2-phenyl-3-styrylpyridines with a 254 nm UV light (64 W) in EtOH under an argon atmosphere in the presence of TFA. The reaction is a dehydrogenative annulation reaction that proceeds through 6π-electrocyclization, a [1,5]-H shift, 1,3-enamine tautomerization, and elimination of a hydrogen molecule to afford 6-phenylbenzo[h]quinolines. The described protocol not only avoids the usage of a transition metal catalyst and an oxidant but also has the advantages of high atom efficiency and mild reaction conditions.

Association between Serum Uric Acid and Hypertension in Han and Yugur of Gansu Province: The China National Health Survey.

INTRODUCTION: Serum uric acid (SUA) has been found correlated with an increased risk of hypertension, but evidence is sparse regarding the association in Gansu Province, especially in Yugur people. This study aimed to explore the nonlinear relationship between SUA levels and hypertension in Han and Yugur people in China. METHODS: The cross-sectional study samples (n = 5,327) were from the China National Health Survey (CNHS) in Gansu Province. Participants were selected using a multistage stratified cluster sampling method. SUA was measured by enzymatic methods. The restricted cubic spline regression was performed to evaluate the shape of the association. RESULTS: The overall prevalence of hypertension and hyperuricemia was 28.4% and 17.0%, respectively, in this study. Comparing the highest (>416.4 µmol/L) to the lowest (<254.1 µmol/L) SUA level groups, the multivariable adjusted differences and 95% confidence intervals (CIs) in blood pressure (BP) were 6.15 (4.22, 8.08) mm Hg and 4.87 (3.51, 6.23) mm Hg for SBP and DBP in Han, and 2.22 (-0.73, 5.18) mm Hg and 2.56 (0.38, 4.75) mm Hg for SBP and DBP in Yugur people, respectively. The corresponding odds ratios (95% CIs) for hypertension were 3.16 (2.26, 4.43) and 2.37 (1.46, 3.89) in Han and Yugur people, respectively. The restricted cubic spline regression models illustrated that both BP level and the risk of hypertension increased with elevated SUA levels in Han and Yugur people. CONCLUSIONS: SUA was significantly and independently associated with an increased risk of hypertension in Han and Yugur people. Prospective studies are needed to confirm these findings.

The C-terminus of the mu opioid receptor is critical in G-protein interaction as demonstrated by a novel graphene biosensor.

Several water-soluble variants of the human mu opioid receptor (wsMORs) have been designed and expressed, which enables the detection of opioids in the nM to pM range using biosensing platforms. The tools previously developed allowed us to investigate MOR and G-protein interactions in a lipid free system to demonstrate that the lipid bilayer might not be essential for the G-protein recognition and binding. In this study, we are able to investigate G-protein interactions with MOR by using graphene enabled technology, in a lipid free system, with a high sensitivity in a real time manner. A new wsMOR with the native C-terminus was designed, expressed and then immobilized on the surfaces of scalable graphene field effect transistor (GFET)-based biosensors, enabling the recording of wsMOR/G-protein interaction with an electronic readout. G-protein only interacts with the wsMOR in the presence of the native MOR C-terminus with a KA of 32.3±11.1 pM. The electronic readout of such interaction is highly reproducible with little variance across 50 devices in one biosensor array. For devices with receptors that do not have the native C-terminus, no significant electronic response was observed in the presence of G-protein, indicating an absence of interaction. These findings reveal that lipid environment is not essential for the G-protein interaction with MOR, however, the C-terminus of MOR is essential for G-protein recognition and high affinity binding. A system to detect MOR-G protein interaction is developed. wsMOR-G2_Cter provides a novel tool to investigate the role of C terminus in the signaling pathway.

Disruption of tight junctions contributes to hyposalivation of salivary glands in a mouse model of type 2 diabetes.

Tight junction (TJ) plays an important role in regulating paracellular fluid transport in salivary glands; however, little is known about the involvement of TJs in diabetes salivary glands. This study aimed to investigate the alterations of TJs and their possible contribution in diabetes-induced hyposalivation. Here, we observed that the morphologies of submandibular glands (SMGs) were impaired, characterized by enlarged acini accumulation with giant secretory granules, which were significantly reduced in atrophic ducts in SMGs of db/db mice, a spontaneous model of type-2 diabetes. However, the secretory granules were increased and scattered in the acini of diabetes parotid glands (PGs). Other ultrastructural damages including swollen mitochondria, expansive endoplasmic reticulum, and autophagosomes were observed in the diabetes group. The levels of TJ proteins including claudin-1 (Cldn1) and claudin-3 (Cldn3) were increased, whereas those of claudin-4 (Cldn4), occludin (Ocln), and zonula occludens-1 (ZO-1) were decreased in SMGs of db/db mice. Higher Cldn1 and Cldn3 and lower claudin-10 (Cldn10) and Ocln levels were observed in PGs of diabetes mice. Taken together, the structures of SMGs and PGs were impaired in diabetes mice, and the disruption of TJ integrity in both SMGs and PGs may contribute to diabetes-induced hyposalivation.

High Biologically Effective Dose Radiotherapy for Brain Metastases May Improve Survival and Decrease Risk for Local Relapse Among Patients With Small-Cell Lung Cancer: A Propensity-Matching Analysis.

To evaluate whether high biologically effective dose (BED) radiotherapy improves local control and survival outcomes for patients with brain metastases (BMs) from small-cell lung cancer (SCLC) and to determine possible prognostic factors. From January 1998 to June 2018, 250 patients with BM from SCLC were retrospectively analyzed. The Cutoff Finder program was used to classify patients by BED. Overall survival (OS) and BM progression-free survival (BM-PFS) were analyzed using the Kaplan-Meier method and log-rank test. A Cox regression model was used to calculate the hazard ratio and 95% CI for prognostic factors for OS among the study population and propensity score (PS)-matched patients. A BED of 47.4 was taken as the optimal cutoff value. Both OS and BM-PFS were significantly improved in the high-BED (>47.4 Gy) than in the low-BED (≤47.4 Gy) group (median OS: 17.5 months vs 9.5 months, P < .001, median BM-PFS: 14.4 months vs 8.3 months, P < .001). Biologically effective dose (P < .001), Eastern Cooperative Oncology Group performance status (P = .047), smoking (P = .005), and pleural effusion (P = .004) were independent prognostic factors for OS. Propensity score matching with a ratio of 1:2 resulted in 57 patients in the high-BED group and 106 patients in the low-BED group. In the PS-matched cohort, OS and BM-PFS were significantly prolonged in the high-BED group compared with the low-BED group (P < .001). Biologically effective dose >47.4 Gy improves survival among patients with BM from SCLC. Eastern Cooperative Oncology Group score, smoking, and pleural effusion independently affect OS of SCLC patients with BM.

Molecular Interaction Between Butorphanol and κ-Opioid Receptor.

BACKGROUND: The misuse of opioids stems, in part, from inadequate knowledge of molecular interactions between opioids and opioid receptors. It is still unclear why some opioids are far more addictive than others. The κ-opioid receptor (KOR) plays a critical role in modulating pain, addiction, and many other physiological and pathological processes. Butorphanol, an opioid analgesic, is a less addictive opioid with unique pharmacological profiles. In this study, we investigated the interaction between butorphanol and KOR to obtain insights into the safe usage of this medication. METHODS: We determined the binding affinity of butorphanol to KOR with a naltrexone competition study. Recombinant KORs expressed in mammalian cell membranes (Chem-1) were used for G-protein activation studies, and a human embryonic kidney-293 (HEK-293) cell line stably transfected with the human KOR was used for ß-arrestin study as previously described in the literature. The effects of butorphanol on KOR internalization were investigated using mouse neuroblastoma Neuro2A cells stably transfected with mKOR-tdTomato fusion protein (N2A-mKOR-tdT) cells overexpressing KOR. The active-state KOR crystal structure was used for docking calculation of butorphanol to characterize the ligand binding site. Salvinorin A, a full KOR agonist, was used as a control for comparison. RESULTS: The affinity of KOR for butorphanol is characterized by Kd of 0.1 ± 0.02 nM, about 20-fold higher compared with that of the µ-opioid receptor (MOR; 2.4 ± 1.2 nM). Our data indicate that butorphanol is more potent on KOR than on MOR. In addition, butorphanol acts as a partial agonist of KOR in the G-protein activation pathway and is a full agonist on the ß-arrestin recruitment pathway, similar to that of salvinorin A. The activation of the ß-arrestin pathway is further confirmed by KOR internalization. The in silico docking model indicates that both salvinorin A and butorphanol share the same binding cavity with the KOR full agonist MP1104. This cavity plays an important role in determining either agonist or antagonist effects of the ligand. CONCLUSIONS: In conclusion, butorphanol is a partial KOR agonist in the G-protein activation pathway and a potent KOR full agonist in the ß-arrestin recruitment pathway. The structure analysis offers insights into the molecular mechanism of KOR interaction and activation by butorphanol.

Ratiometric fluorescent nanosensors for ultra-sensitive detection of mercury ions based on AuNCs/MOFs.

Ratiometric fluorescent nanosensors were developed to detect mercury ions (Hg2+) using enhanced dual emissions from glutathione stabilized gold nanoclusters/indium-based metal-organic frameworks modified with cysteine (AuNCs/MIL-68(In)-NH2/Cys). The nanosensors exhibited bright pink fluorescence with AuNCs evenly distributed on MIL-68(In)-NH2. Under 370 nm excitation, the obtained sensor presented double fluorescence emission around 438 nm and 668 nm, which was attributed to MIL-68(In)-NH2 and GSH-AuNCs, respectively. The fluorescence emission was remarkably enhanced after modification with Cys. In the presence of Hg2+, the red fluorescence peak at 668 nm was quenched, while the blue fluorescence peak at 438 nm was slightly altered. The prepared AuNCs/MIL-68(In)-NH2/Cys nanosensors exhibited two linear ranges for the detection of Hg2+, namely from 20 pM to 0.2 µM and 0.2 µM to 60 µM, with a detection limit of 6.7 pM. They also presented high selectivity towards other ions and good performance in real water samples. Moreover, a radial star-shaped microfluidic paper-based analytical device (µPAD), as a straightforward and convenient platform, was successfully fabricated for the visual detection of Hg2+ with a wide detection range from 5 nM to 50 µM.

Dezocine Alleviates Morphine-Induced Dependence in Rats.

BACKGROUND: Opioid dependence is a major public health issue without optimal therapeutics. This study investigates the potential therapeutic effect of dezocine, a nonaddictive opioid, in opioid dependence in rat models. METHODS: Dezocine was administered intraperitoneally to a morphine-dependent rat model to investigate its effect on withdrawal and conditioned place preference (CPP). Effect of dezocine on morphine withdrawal syndrome and CPP was analyzed using 2-way analysis of variance (ANOVA) followed by Tukey's post hoc test. Buprenorphine and vehicle solution containing 20% (v/v) dimethyl sulfoxide were used for positive and negative control, respectively. The astrocytes activation in nucleus accumbens was assessed by immunofluorescence assay of glial fibrillary acidic protein. Effect of dezocine and buprenorphine on the internalization of κ opioid receptor (KOR) was investigated using Neuro2A expressing KOR fused to red fluorescent protein tdTomato (KOR-tdT). Buprenorphine and dezocine were screened against 44 G-protein-coupled receptors, ion channels, and transporter proteins using radioligand-binding assay to compare the molecular targets. RESULTS: The mean withdrawal score was reduced in rats treated with 1.25 mg·kg dezocine compared to vehicle-treated control animals starting from the day 1 (mean difference: 7.8; 95% confidence interval [CI], 6.35-9.25; P < .0001 by 2-way ANOVA). Significance was observed at all treatment days, including day 7 (mean difference: 2.13; 95% CI, 0.68-3.58; P < .001 by 2-way ANOVA). Furthermore, dezocine inhibited the reinstatement of morphine-induced CPP (mean difference: 314; 95% CI, 197.9-430.1; P < .0001 by 2-way ANOVA) compared to the control group. Chronic morphine administration induced astrocytes activation in nucleus accumbens, which was attenuated by dezocine. Dezocine blocked the agonist-induced KOR internalization in vitro, 1 of the mechanisms involved in the downstream signaling and development of opioid dependence. Dezocine had affinity to norepinephrine and serotonin transporters and sigma-1 receptor, whereas buprenorphine showed no activity against these targets. CONCLUSIONS: Dezocine could potentially be used to alleviate opioid dependence. Due to the unique molecular target profile different from buprenorphine, it might have important value in studying the mechanisms of morphine dependence and developing novel therapeutic approaches.

Sodium 4-phenylbutyrate Attenuates High-fat Diet-induced Impaired Spermatogenesis.

OBJECTIVE: To determine the mitigating effects of sodium 4-phenylbutyrate (4-PBA) on high-fat diet (HFD)-induced spermatogenesis dysfunction. METHODS: Male rats (n = 30) were randomly divided into three groups: control, HFD, and 4-PBA (HFD +4-PBA). After 13 weeks, rats were euthanized. Testes and epididymis were harvested for further analysis. Sex hormones were detected, and hematoxylin and eosin staining was performed to examine the histological changes in the testes. Semen samples were collected to evaluate sperm quality. Spermatogenic cell apoptosis was detected by TUNEL assay. RESULTS: Compared with the control group, the final body weight and body weight gain were significantly higher in HFD-fed rats, while the testicle/body weight ratios were lower (P < 0.05). In HFD-fed rats, obvious pathological changes in the testicular tissue were observed. Treatment with 4-PBA attenuated HFD-induced histological damage, ameliorated the HFD-induced decrease in serum testosterone (T), and reduced the rate of testicular cell apoptosis (P < 0.05) in obese male rats. Finally, 4-PBA significantly improved semen parameters in HFD rats (P < 0.05). CONCLUSION: HFD exposure induced detrimental effects on spermatogenesis, semen quality, serum T level, and testicular cell apoptosis in rats. Treatment with 4-PBA ameliorated HFD？induced impaired spermatogenesis via inhibition of apop-tosis in rats. 4-PBA may have therapeutic value in the treatment of obesity？related impairment of spermatogenesis.

Mutations in KARS cause early-onset hearing loss and leukoencephalopathy: Potential pathogenic mechanism.

Leukoencephalopathies are a broad class of common neurologic deterioration for which the etiology remains unsolved in many cases. In a Chinese Han family segregated with sensorineural hearing loss and leukoencephalopathy, candidate pathogenic variants were identified by targeted next-generation sequencing of 144 genes associated with deafness and 108 genes with leukoencephalopathy. Novel compound heterozygous mutations p.R477H and p.P505S were identified in KARS, which encodes lysyl-tRNA synthetase (LysRS), as the only candidate causative variants. These two mutations were functionally characterized by enzymatic assays, immunofluorescence, circular dichroism analysis, and gel filtration chromatography. Despite no alteration in the dimer-tetramer oligomerization and cellular distribution by either mutation, the protein structure was notably influenced by the R477H mutation, which subsequently released the protein from the multiple-synthetase complex (MSC). Mutant LysRSs with the R477H and P505S mutations had decreased tRNALys aminoacylation and displayed a cumulative effect when introduced simultaneously. Our studies showed that mutations in KARS lead to a newly defined subtype of leukoencephalopathy associated with sensorineural hearing impairment. The combined effect of reduced aminoacylation and release of LysRS from the MSC likely underlies the pathogenesis of the KARS mutations identified in this study.

[Effects of dexamethasone on MRL/lpr mice with systemic lupus erythematosus complicated with cognitive dysfunction].

OBJECTIVE: To evaluate the effects of dexamethasone on systemic lupus erythematosus complicated with cognitive dysfunction.
 Methods: Ten wild type mice and 20 MRL/lpr mice were applied for the research. MRL/lpr mice were randomly assigned to a MRL/lpr group and a MRL/lpr + dexamethasone (1.5 mg/kg) group. Interleukin-6 (IL-6), IL-1ß, and tumor necrosis factor alpha (TNF-α) in serum and hippocampus were detected. The protein phosphorylation levels of phosphoinositide 3-kinase (P-PI3K), protein kinase B (P-Akt), NF-kappa-B inhibitor alpha (P-IκBa) and nuclear transcription factor kappa-B p65 (P-NF-κB p65) were detected by Western blot, the level of P-NF-κB p65 also was detected by immunohistochemistry. 
 Results: Treatment with dexamethasone (1.5 mg/kg) alleviated the cognitive dysfunction and decreased the levels of IL-6, IL-1ß and TNF-α in serum and hippocampus, and reduced the levels of P-PI3K, P-Akt, P-IκBa and P-NF-κB p65 in hippocampus in MRL/lpr mice.
 Conclusion: Dexamethasone may play a protective role in the cognitive function by decreasing the levels of TNF-α and IL-1ß in the hippocampus of MRL/lpr lupus mice.

Shifts of live bacterial community in secondary effluent by chlorine disinfection revealed by Miseq high-throughput sequencing combined with propidium monoazide treatment.

Chlorine disinfection is a commonly used disinfection process in wastewater treatment, but its effects on the indigenous bacterial community in treated wastewater have not been fully elucidated. In this study, secondary effluent samples collected in four wastewater treatment plants (WWTPs) were selected for chlorine disinfection. Shifts in the bacterial community compositions in secondary effluent samples upon chlorine disinfection, both immediately and after 24 h of storage, were investigated using Illumina MiSeq sequencing combined with propidium monoazide (PMA) treatment. The results showed that the phylum Proteobacteria was sensitive to chlorine, with the relative proportions of Proteobacteria decreased from 39.2 to 75.9 % in secondary effluent samples to 7.5 to 62.2 % immediately after chlorine disinfection. The phylogenetic analysis indicated that the most dominant genera belonging to Proteobacteria were sensitive to chlorine. In contrast, the phyla Firmicutes and Planctomycetes showed a certain resistance to chlorine, with their relative proportions increasing from 5.1 to 23.1 % and 0.8 to 9.3 % to 11.3 to 44.6 % and 1.5 to 13.3 %, respectively. Most dominant genera belonging to Firmicutes showed resistance to chlorine. A significant reduction in the richness and diversity of the bacterial community was observed after 24 h of storage of chlorinated secondary effluent. During the 24-h storage process, the relative proportions of most dominant phyla shifted in reverse from the changes induced by chlorine disinfection. Overall, chlorine disinfection not only changes the bacterial community compositions immediately after the disinfection process but also exerts further impacts over a longer period (24 h).