Causative Microorganisms Isolated from Patients with Intra-Abdominal Infections and Their Drug Resistance Profiles: An 11-Year (2011-2021) Single-Center Retrospective Study.

Objective: To investigate the distribution and antimicrobial susceptibility of causative microorganisms recovered from patients with intra-abdominal infections (IAIs). Methods: A total of 2,926 bacterial and fungal strains were identified in samples collected from 1,679 patients with IAIs at the Peking Union Medical College Hospital between 2011 and 2021. Pathogenic bacteria and fungi were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing (AST) was performed using the VITEK 2 compact system and the Kirby-Bauer method. AST results were interpreted based on the M100-Ed31 clinical breakpoints of the Clinical and Laboratory Standards Institute. Results: Of the 2,926 strains identified, 49.2%, 40.8%, and 9.5% were gram-negative bacteria, gram-positive bacteria, and fungi, respectively. Escherichia coli was the most prevalent pathogen in intensive care unit (ICU) and non-ICU patients; however, a significant decrease was observed in the isolation of E. coli between 2011 and 2021. Specifically, significant decreases were observed between 2011 and 2021 in the levels of extended-spectrum ß-lactamase (ESBL)-producing E. coli (from 76.9% to 14.3%) and Klebsiella pneumoniae (from 45.8% to 4.8%). Polymicrobial infections, particularly those involving co-infection with gram-positive and gram-negative bacteria, were commonly observed in IAI patients. Moreover, Candida albicans was more commonly isolated from hospital-associated IAI samples, while Staphylococcus epidermidis had a higher ratio in community-associated IAIs. Additionally, AST results revealed that most antimicrobial agents performed better in non-ESBL-producers than in ESBL-producers, while the overall resistance rates (56.9%-76.8%) of Acinetobacter baumanmii were higher against all antimicrobial agents than those of other common gram-negative bacteria. Indeed, Enterococcus faecium, Enterococcus faecalis, S. epidermidis, and S. aureus were consistently found to be susceptible to vancomycin, teicoplanin, and linezolid. Similarly, C. albicans exhibited high susceptibility to all the tested antifungal drugs. Conclusion: The distribution and antimicrobial susceptibility of the causative microorganisms from patients with IAIs were altered between 2011 and 2021. This finding is valuable for the implementation of evidence-based antimicrobial therapy and provides guidance for the control of hospital infections.

Analysis of 50 cases of bloodstream infection with Listeria monocytogenes / 中国热带医学

@#Abstract: Objective　To analyze the characteristics of bloodstream infection of Listeria monocytogenes and provide basis for the diagnosis and treatment of the disease. Methods　We retrospectively analyzed the cases of Listeria monomyrhosi bloodstream infection in Peking Union Medical College Hospital (PUMCH) from April 2012 to April 2022. The age, sex, onset time, underlying disease, symptoms, diagnosis, treatment and prognosis of the patients were analyzed, as well as the changes of white blood cells (WBC), neutrophils, lymphocytes, and C-reactive protein (CRP) before and after anti-infection treatment. Results　Fifty cases of Listeria monocytogenes bloodstream infection confirmed by blood culture were involved. The age of patients ranged from 0 to 82 (43.7±20.0) years old, among whom 20.0% were over 60 years old. The onset time of patients was the highest in spring (44.0%), followed by winter (24.0%), and relatively fewer in summer and autumn (14.0%-18.0%). The median diagnosis time was 3 days (1-60 days). After the etiological diagnosis, 45 patients (90.0%) had underlying diseases or pregnancy status, and 45 patients were adjusted to the target antibacterial treatment mainly with carbapenems (48.9%) and penicillins (44.4%). The level of WBC, neutrophils, lymphocytes, monocytes, and CRP after treatment were significantly lower than those pre-treatments (P<0.05). Among all patients, 36 cases (72.0%) were treated according to the Antimicrobial Treatment Guidelines for Fever Sanford, of which 26 cases (72.2%) were discharged from the hospital, two cases died, one case was transferred to other hospitals, and 7 cases had a poor prognosis. Conclusions　Autoimmune diseases, tumor diseases, pregnant patients are susceptible to Listeria monocytogenes infection. Penicillins are the first choice for effective empiric therapy. For the patients allergic to penicillins, trimethoprim/sulfamethoxazole or meropenem could be used.

Sex Difference of Ribosome in Stroke-Induced Peripheral Immunosuppression by Integrated Bioinformatics Analysis.

Ischemic stroke (IS) greatly threatens human health resulting in high mortality and substantial loss of function. Recent studies have shown that the outcome of IS has sex specific, but its mechanism is still unclear. This study is aimed at identifying the sexually dimorphic to peripheral immune response in IS progression, predicting potential prognostic biomarkers that can lead to sex-specific outcome, and revealing potential treatment targets. Gene expression dataset GSE37587, including 68 peripheral whole blood samples which were collected within 24 hours from known onset of symptom and again at 24-48 hours after onset (20 women and 14 men), was downloaded from the Gene Expression Omnibus (GEO) datasets. First, using Bioconductor R package, two kinds of differentially expressed genes (DEGs) (nonsex-specific- and sex-specific-DEGs) were screened by follow-up (24-48 hours) vs. baseline (24 hours). 30 nonsex-specific DEGs (1 upregulated and 29 downregulated), 79 female-specific DEGs (25 upregulated and 54 downregulated), and none of male-specific DEGs were obtained finally. Second, bioinformatics analysis of female-specific DEGs was performed. Gene Ontology (GO) functional annotation analysis shows that DEGs were mainly enriched in translational initiation, cytosolic ribosome, and structural constituent of ribosome. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis shows that the top 6 enrichment pathways are ribosome, nuclear factor--kappa B (NF-kappa B) signaling pathway, apoptosis, mineral absorption, nonalcoholic fatty liver disease, and pertussis. Three functional modules were clustered in the protein-protein interaction (PPI) network of DEGs. The top 10 key genes of the PPI network constructed were selected, including RPS14, RPS15A, RPS24, FAU, RPL27, RPL31, RPL34, RPL35A, RSL24D1, and EEF1B2. Sex difference of ribosome in stroke-induced peripheral immunosuppression may be the potential mechanism of sex disparities in outcome after IS, and women are more likely to have stroke-induced immunosuppression. RPS14, RPS15A, RPS24, FAU, RPL27, RPL31, RPL34, RPL35A, RSL24D1, and EEF1B2 may be novel prognostic biomarkers and potential therapeutic targets for IS.

Prevalence and risk factors of nocturnal enuresis among children ages 5-12 years in Xi'an, China: a cross-sectional study.

BACKGROUND: Nocturnal enuresis (NE) has a negative impact on children's health and imposes a long-term burden on families. With economic development and cultural improvements, parents and medical professionals pay more attention to NE. The aim of this study was to investigate the prevalence and risk factors of NE among children ages 5-12 years in Xi'an, China. METHODS: A stratified cluster sampling method was used to conduct a cross-sectional study of NE in 10 kindergartens and 20 primary schools in Xi'an. We used univariate analysis to compare the prevalences of characteristics such as gender, duration of disposable diaper (DD) use, toilet training onset time, daily living habits, academic performance, and family history of NE. Logistic regression analysis was used to calculate odds ratio and to determine risk factors of NE. RESULTS: The study included 6568 children ages 5-12 years, of which 262 (3.99%) had NE. The prevalence rates of NE decreased with age, with the highest prevalence at age 5 (9.09% for boys; 6.03% for girls). However, the prevalence increased with duration of DD use. Children experienced more NE if they never accepted toilet training (7.83%) or if they drank sugary beverages during the day (5.36%). Sleep disorders, sweets intake, drinking low amounts of plain water during the day, and family history of NE, were statistically associated with NE. CONCLUSION: NE was closely associated with a family history of NE, being male, long-term use of DD, delayed toilet training, drinking sugary beverages and/or consuming little plain water, and sleep disorders. A supportive parental attitude towards NE and timely medical treatment can improve the quality of life of enuretic children.

Shear Stress Rescued the Neuronal Impairment Induced by Global Cerebral Ischemia Reperfusion via Activating PECAM-1-eNOS-NO Pathway.

Microvessel hypoperfusion following ischemic stress resulted in a decreased shear stress of brain microvascular endothelial cells (BMECs) and contributed to abnormal expression of PECAM-1 after global cerebral ischemia/reperfusion (I/R) injury. Here, we identified novel pathophysiologic and rehabilitative procedures specific to shear stress in microvascular endothelial cells in response to global cerebral I/R injury. We found that the decrease in cerebral blood flow of gerbils after global cerebral I/R injury reduces shear stress, and the abnormal change in shear stress leads to microvascular endothelial cell and neuron damage. Nevertheless, suitable high levels of shear stress contribute to rescuing the dysfunction and malformation of BMECs via regulating the PECAM-1-eNOS-NO pathway to enhance nitric oxide release, decrease the expression of caspase-3 to reduce apoptosis, and improve the shear-adaptability of endothelial cells, thereby playing a protective role in the gerbil brain.

Genotypic differences in CC224, CC363, CC449 and CC446 of Moraxella catarrhalis isolates based on whole genome SNP, MLST and PFGE typing.

Understanding the evolutionary path of M. catarrhalis from macrolide-susceptible to macrolide-resistant organism, is important for hindering macrolide resistance from propagation. Multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and whole genome SNP typing (WGST), as useful and practical typing tools, have both advantages and disadvantages. We studied the utility of these 3 typing methods, including the level of agreement, consistency and drawbacks, in characterizing M. catarrhalis clones and clonal complexes. We focused on four clonal complexes [CC224, CC363, CC449 (CCN10) and CC446 (CCN08)] and found that PFGE and WGST had a high level of agreement and a proper consistency of the same clone or very closely related clones, while MLST is less discriminatory for different clones. Furthermore, we also established an evolutionary distance cut-off value for "The same clone". Moreover, we detected macrolide-resistant M. catarrhalis in CC224, which had previously been considered as a macrolide-susceptible clonal complex. A higher number of isolates belonged to ST215 compared to ST446, implying that ST215 is more likely to be the primary founder. Our study also demonstrated that all the four clonal complexes belong to the M. catarrhalis lineage 1, which is considered to be related to increased virulence potential and serum resistance. We also observed that copB II was highly related to CC449 and LOS type B was mainly confined in CC224. In conclusion, these findings provide further insight into the evolutionary characteristics of M. catarrhalis.

[Effect of miR-214 on Fludarabine Resistance in Chronic Lymphocytic Leukemia].

OBJECTIVE: To investigate effect and mechanism of miR-214 in fludarabine resistance of chronic lympho-cytic leukemia (CLL). METHODS: A total of 10 patients with CLL resistante to fludarabine (Flu) and 10 healthy persons admitted to Hematology Department of our hospital in August 2014 - July 2018 were selected. Expression level of miR-214 in mononuclear cells in patients with CLL and healthy persons were determined by RT-PCR. Primary CLL cells from patients with CLL were divided into normal control group (control group), negative control group (miR-214-NC group) and viral transinfection group (miR-214-ASO group). After 24 h-transfection, CLL cells were cultured with different con-centration of Flu for 48 h, then the cell proliferation and apoptosis were detected, and the levels of down-stream genes and proteins releted with PTEN and PI3K/AKT signialing pathway were determined. RESULTS: The expression level of miR-214 in mononuclear cells of CLL patients significantly increased in comparison with healthy persons(P<0.05); the expression level of miR-214 in miR-214-ASO group significantly decreased (P<0.05); Absorbance in control group at Flu concentration of 3, 10 and 30 µmol/L was significantly decreased (P<0.05). Apoptosis rate in miR-214-ASO group at Flu concentration of 10 mmol/L significantly increased (P<0.05). At Flu concentration of 10 mmol/L, mRNA levels PTEN and BAD in miR-214-ASO group significantly increased (P<0.05), but mRNA levels of MDM2 and NF-κB significantly decreased (P<0.05). At Flu concentration of 10 mmol/L, protein levels of PTEN and p-BAD in miR-214-ASO group significantly increased (P<0.05), but protein levels of MDM2 and NF-κB significantly decreased (P<0.05). CONCLUSION: Inhibition of miR-214 can enhance the sensitivity of drug-resistant CLL cells to fludarabine, which may be raleted with the promotion of cell apotosis and regulation of down-stream molecules expression of PTEN/AKT signaling pathway.

[Clinical and Laboratory Characteristics of Disseminated Non-tuberculous Mycobacterial Disease].

Objective To explore the clinical and laboratory characteristics and the prognosis of disseminated non-tuberculous mycobacteria(NTM)diseases in human immunodeficiency virus(HIV)negative patients. Methods Cases of disseminated NTM disease were retrospectively collected in Peking Union Medical College Hospital from January 2012 to October 2018.Clinical manifestations,laboratory findings,treatment,and prognosis of these cases were retrieved from the electronic medical record system. Results Among the 23 HIV negative patients with disseminated NTM disease,21 had underlying diseases,with rheumatoid immune disease(n=7)as the most common one.The main clinical manifestation was fever(n=23).Laboratory tests showed anemia [hemoglobin(85.78±25.47)g/L],hypoalbuminemia [albumin 29(27-32)g/L],elevated erythrocyte sedimentation rate [(85.73±43.78)mm/h] and hypersensitive C-reactive protein [(112.00±70.90)mg/L],and reduction of lymphocyte count [0.69(0.29-2.10)×10 9/L].Lymphocyte subset analysis indicated reduction in CD4 + T cells [213(113-775)/µl],CD8 + T cells [267(99-457)/µl],B cells [39(4-165)/µl],and NK cells [88(32-279)/µl] and elevation of human leukocyte antigen-D related(HLA-DR),and CD38 expression in CD8 + T cells [HLA-DR +CD8 +/CD8 +,60(40-68)%;CD38 +CD8 +/CD8 +,81(65-90)%].The most common species of NTM was Mycobacterium intracellular(n=6).Lymphocyte,CD8 + T cell,B cell,and NK cell counts were significantly lower in dead patients than surviving patients(P =0.045,P=0.045,P=0.032,and P=0.010,respectively). Conclusions Disseminated NTM disease in HIV negative patients is mainly manifested as fever,anemia,hypoalbuminemia,and elevated inflammatory indicators.It is more likely to occur in immunocompromised patients.Patients with decreased lymphocytes,CD8 + T cells,B cells and NK cells tend to have a poor prognosis.

Molecular characterization of vancomycin-resistant enterococci isolated from a hospital in Beijing, China.

OBJECTIVE: To investigate the occurrence of vancomycin-resistant enterococci (VRE) isolated from patients in Peking Union Medical College Hospital, Beijing, China from 2011 to 2017, and to evaluate their resistance mechanisms and genetic relatedness. METHODS: All isolates were identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). Antibiotic susceptibility testing was performed using the broth microdilution method. Molecular characterization were detected by PCR and sequencing. Genotyping of VRE isolates was performed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) analysis. Virulence genes were detected by multiplex PCR. RESULTS: A total of 87 consecutive VRE were collected, including 84 isolates of vancomycin resistant Enterococcus faecium (VREfm) and 3 isolates of Enterococcus faecalis (VREfs). Urine (40.2%, 35/87) and blood (17.2%, 15/87) were the most commonly specimens. All VREfm isolates were resistant to ampicillin, and were susceptible to daptomycin, linezolid and tigecycline. The resistant rate of teicoplanin was 47.6%. All of the VREfm isolates carried the vanA gene, no isolates carried vanB. 11.9% (10/84) VREfm isolates carried both vanA and vanM. Among them, 76.2% (64/84) and 66.7% (56/84) carried esp and hyl, respectively. The 3 vancomycin resistant E. faecalis (VREfs) isolates were varied, and only one carried vanB. A total of 3 and 18 STs were detected among VREfs and VREfm strains, respectively. PFGE results indicated a genetic diversity among VREfm isolates. CONCLUSION: This study confirms that VREfm isolates associated with ST78 were the main epidemic lineage responsible for nosocomial infections in China, as were also observed in other nations worldwide.

Voltage-Induced Ca²âº Release in Postganglionic Sympathetic Neurons in Adult Mice.

Recent studies have provided evidence that depolarization in the absence of extracellular Ca2+ can trigger Ca2+ release from internal stores in a variety of neuron subtypes. Here we examine whether postganglionic sympathetic neurons are able to mobilize Ca2+ from intracellular stores in response to depolarization, independent of Ca2+ influx. We measured changes in cytosolic ΔF/F0 in individual fluo-4 -loaded sympathetic ganglion neurons in response to maintained K+ depolarization in the presence (2 mM) and absence of extracellular Ca2+ ([Ca2+]e). Progressive elevations in extracellular [K+]e caused increasing membrane depolarizations that were of similar magnitude in 0 and 2 mM [Ca2+]e. Peak amplitude of ΔF/F0 transients in 2 mM [Ca2+]e increased in a linear fashion as the membrane become more depolarized. Peak elevations of ΔF/F0 in 0 mM [Ca2+]e were ~5-10% of those evoked at the same membrane potential in 2 mM [Ca2+]e and exhibited an inverse U-shaped dependence on voltage. Both the rise and decay of ΔF/F0 transients in 0 mM [Ca2+]e were slower than those of ΔF/F0 transients evoked in 2 mM [Ca2+]e. Rises in ΔF/F0 evoked by high [K+]e in the absence of extracellular Ca2+ were blocked by thapsigargin, an inhibitor of endoplasmic reticulum Ca2+ ATPase, or the inositol 1,4,5-triphosphate (IP3) receptor antagonists 2-aminoethoxydiphenyl borate and xestospongin C, but not by extracellular Cd2+, the dihydropyridine antagonist nifedipine, or by ryanodine at concentrations that caused depletion of ryanodine-sensitive Ca2+ stores. These results support the notion that postganglionic sympathetic neurons possess the ability to release Ca2+ from IP3-sensitive internal stores in response to membrane depolarization, independent of Ca2+ influx.

Construction and analysis of cardiac hypertrophy-associated lncRNA-mRNA network based on competitive endogenous RNA reveal functional lncRNAs in cardiac hypertrophy.

Cardiac hypertrophy (CH) could increase cardiac after-load and lead to heart failure. Recent studies have suggested that long non-coding RNA (lncRNA) played a crucial role in the process of the cardiac hypertrophy, such as Mhrt, TERMINATOR. Some studies have further found a new interacting mechanism, competitive endogenous RNA (ceRNA), of which lncRNA could interact with micro-RNAs (miRNA) and indirectly interact with mRNAs through competing interactions. However, the mechanism of ceRNA regulated by lncRNA in the CH remained unclear. In our study, we generated a global triple network containing mRNA, miRNA and lncRNA, and extracted a CH related lncRNA-mRNA network (CHLMN) through integrating the data from starbase, miRanda database and gene expression profile. Based on the ceRNA mechanism, we analyzed the characters of CHLMN and found that 3 lncRNAs (SLC26A4-AS1, RP11-344E13.3 and MAGI1-IT1) were high related to CH. We further performed cluster module analysis and random walk with restart for the CHLMN, finally 14 lncRNAs had been discovered as the potential CH related disease genes. Our results showed that lncRNA played an important role in the CH and could shed new light to the understanding underlying mechanisms of the CH.

Ketamine-mediated afferent-specific presynaptic transmission blocks in low-threshold and sex-specific subpopulation of myelinated Ah-type baroreceptor neurons of rats.

BACKGROUND: Ketamine enhances autonomic activity, and unmyelinated C-type baroreceptor afferents are more susceptible to be blocked by ketamine than myelinated A-types. However, the presynaptic transmission block in low-threshold and sex-specific myelinated Ah-type baroreceptor neurons (BRNs) is not elucidated.  METHODS: Action potentials (APs) and excitatory post-synaptic currents (EPSCs) were investigated in BRNs/barosensitive neurons identified by conduction velocity (CV), capsaicin-conjugated with Iberiotoxin-sensitivity and fluorescent dye using intact nodose slice and brainstem slice in adult female rats. The expression of mRNA and targeted protein for NMDAR1 was also evaluated.  RESULTS: Ketamine time-dependently blocked afferent CV in Ah-types in nodose slice with significant changes in AP discharge. The concentration-dependent inhibition of ketamine on AP discharge profiles were also assessed and observed using isolated Ah-type BRNs with dramatic reduction in neuroexcitability. In brainstem slice, the 2nd-order capsaicin-resistant EPSCs were identified and ~50% of them were blocked by ketamine concentration-dependently with IC50 estimated at 84.4 µM compared with the rest (708.2 µM). Interestingly, the peak, decay time constant, and area under curve of EPSCs were significantly enhanced by 100 nM iberiotoxin in ketamine-more sensitive myelinated NTS neurons (most likely Ah-types), rather than ketamine-less sensitive ones (A-types).  CONCLUSIONS: These data have demonstrated, for the first time, that low-threshold and sex-specific myelinated Ah-type BRNs in nodose and Ah-type barosensitive neurons in NTS are more susceptible to ketamine and may play crucial roles in not only mean blood pressure regulation but also buffering dynamic changes in pressure, as well as the ketamine-mediated cardiovascular dysfunction through sexual-dimorphic baroreflex afferent pathway.

Na+-induced Ca2+ influx through reverse mode of Na+-Ca2+ exchanger in mouse ventricular cardiomyocyte.

BACKGROUND: Dobutamine is commonly used for clinical management of heart failure and its pharmacological effects have long been investigated as inotropics via ß-receptor activation. However, there is no electrophysiological evidence if dobutamine contributes inotropic action due at least partially to the reverse mode of Na+-Ca2+ exchanger (NCX) activation. METHODS: Action potential (AP), voltage-gated Na+ (INa), Ca2+ (ICa), and K+ (Ito and IK1) currents were observed using whole-cell patch technique before and after dobutamine in ventricular cardiomyocytes isolated from adult mouse hearts. Another sets of observation were also performed with Kb-r7943 or in the solution without [Ca2+]o. RESULTS: Dobutamine (0.1-1.0 µM) significantly enhanced the AP depolarization with prolongation of AP duration (APD) in a concentration-dependent fashion. The density of INa was also increased concentration-dependently without alternation of voltage-dependent steady-status of activation and inactivation, reactivation as well. Whereas, the activities for ICa, Ito, and IK1 were not changed by dobutamine. Intriguingly, the dobutamine-mediated changes in AP repolarization were abolished by 3 µM Kb-r7943 pretreatment or by simply removing [Ca2+]o without affecting accelerated depolarization. Additionally, the ratio of APD50/APD90 was not significantly altered in the presence of dobutamine, implying that effective refractory period was remain unchanged. CONCLUSIONS: This novel finding provides evidence that dobutamine upregulates of voltage-gated Na+ channel function and Na+ influx-induced activation of the reverse mode of NCX, suggesting that dobutamine may not only accelerate ventricular contraction via fast depolarization but also cause Ca2+ influx, which contributes its positive inotropic effect synergistically with ß-receptor activation without increasing the arrhythmogenetic risk.

KCa1.1 is potential marker for distinguishing Ah-type baroreceptor neurons in NTS and contributes to sex-specific presynaptic neurotransmission in baroreflex afferent pathway.

Sexual-dimorphic neurocontrol of circulation has been described in baroreflex due largely to the function of myelinated Ah-type baroreceptor neurons (BRNs, 1st-order) in nodose. However, it remains unclear if sex- and afferent-specific neurotransmission could also be observed in the central synapses within nucleus of solitary track (NTS, 2nd-order). According to the principle of no mixed neurotransmission among afferents and differentiation of Ah- and A-types to iberiotoxin (IbTX) observed in nodose, the 2nd-order Ah-type BRNs are highly expected. To test this hypothesis, the excitatory post-synaptic currents (EPSCs) were recorded in identified 2nd-order BRNs before and after IbTX using brain slice and whole-cell patch. These results showed that, in male rats, the dynamics of EPSCs in capsaicin-sensitive C-types were dramatically altered by IbTX, but not in capsaicin-insensitive A-types. Interestingly, near 50% capsaicin-insensitive neurons in females showed similar effects to C-types, suggesting the existence of Ah-types in NTS, which may be the likely reason why the females had lower blood pressure and higher sensitivity to aortic depressor nerve stimulation via KCa1.1-mediated presynaptic glutamate release from Ah-type afferent terminals.

Topiramate protects against glutamate excitotoxicity via activating BDNF/TrkB-dependent ERK pathway in rodent hippocampal neurons.

Topiramate (TPM) was previously found to have neuroprotection against neuronal injury in epileptic and ischemic models. However, whether TPM protects against glutamate-induced excitotoxicity in hippocampal neurons is elusive. Our present work aimed to evaluate the protective effect of TPM against glutamate toxicity in hippocampal neurons and further figure out the potential molecular mechanisms. The in vitro glutamate excitotoxic model was prepared with 125µM glutamate for 20min. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) analysis and Hoechst 33342 staining were conducted to detect neuronal survival. The protein expressions of brain-derived neurotrophic factor (BDNF), TrkB, mitogen-activated protein kinase (MAPK) cascade (including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 MAPK), cyclic AMP response element binding protein (CREB), Bcl-2, Bax and ß-actin were detected via Western blot assay. Our results demonstrated that TPM protected hippocampal neurons from glutamate toxicity. Meanwhile, the pretreatment of TPM for 10min significantly prevented the down-regulation of BDNF and the phosphorylation of TrkB. Furthermore, the elevation of phosphorylated EKR expression was significantly inhibited after blockade of TrkB by TrkB IgG, while no alterations of phosphorylated JNK and p38 MAPK were found in the cultured hippocampal neurons. Besides, it was also found that the enhanced phosphorylation of CREB was evidently reversed under excitotoxic conditions after treating with U0126 (the selective inhibitor of ERK). The protein level of Bcl-2 was also observed to be remarkably increased after TPM treatment. In conclusion, these findings implicate that TPM exerts neuroprotective effects against glutamate excitotoxicity in hippocampal neurons and its protection may be modulated through BDNF/TrkB-dependent ERK pathway.

Role of calcium-sensing receptor in cardiac injury of hereditary epileptic rats.

BACKGROUND: It has been reported that epilepsy leads to cardiac injury, but the underlying mechanisms have not yet been elucidated. Studies indicated that the calcium-sensing receptor (CaSR) is involved in cardiomyocyte apoptosis. However, the role of CaSR in epilepsy-induced cardiac injury remains unclear. OBJECTIVE: The aim of this study was to investigate the effects of CaSR on cardiac injury of hereditary epileptic rats. METHODS: The tremor (TRM) rat was used as an epilepsy model. Apoptotic rate, collagen volume fraction, and the expression of CaSR, Bcl-2, Bax, caspase-3, extracellular signal-regulated protein kinase (ERK), c-Jun NH2-terminal protein kinase (JNK), p38 mitogen-activated protein kinase (MAPK), transforming growth factor-ß1 (TGF-ß1), connective tissue growth factor (CTGF), collagen I and collagen III protein were analyzed. RESULTS: The results showed that the CaSR protein was increased in TRM rat hearts. Cardiac apoptosis and fibrosis were also observed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and Masson's trichrome staining, respectively. Further results demonstrated that the expression of Bax, caspase-3, P-JNK, P-p38, TGF-ß1, CTGF, collagen I and collagen III protein were upregulated, whereas Bcl-2 and P-ERK were downregulated in TRM rat hearts. Moreover, these deleterious changes were further aggravated by GdCl3 and attenuated by NPS-2390. CONCLUSIONS: Our results suggest that CaSR promotes cardiac apoptosis and fibrosis in TRM rat through the induction of mitochondrial and MAPK pathways as well as the activation of TGF-ß1 and CTGF.

Activation of peroxisome proliferator-activated receptor γ (PPARγ) through NF-κB/Brg1 and TGF-ß1 pathways attenuates cardiac remodeling in pressure-overloaded rat hearts.

BACKGROUND/AIMS: Cardiac remodeling is a common pathophysiological change along with chronic hypertension and myocardial infarction. Recent evidence indicated that cardiac tissue expressed peroxisome proliferator-activated receptor γ (PPARγ). However, the functional role of PPARγ in cardiac remodeling remained unclear. The present study was designed to investigate the relationship between PPARγ activation and pressure overload-induced cardiac remodeling. METHODS: Cardiac remodeling model was successfully established by abdominal aorta ligation. Cardiac fibrosis and cardiomyocyte hypertrophy were simulated by 100 nM angiotensin II (Ang II) in vitro. Haemodynamic parameters, the expressions of Brg1, α-MHC, ß-MHC, transforming growth factor beta 1 (TGF-ß1), collagen-I, collagen-III and NF-κB were examined. RESULTS: Morphological and haemodynamic measurements showed that the activation of PPARγ improved the impaired cardiac function and decreased interstitial fibrosis in cardiac remodeling rats. Further results also showed that the activation of PPARγ inhibited the expressions of Brg1 and TGF-ß1 in the cardiac remodeling hearts. The activation of PPARγ also inhibited the proliferation and collagen production of cardiac fibroblasts, and down-regulated the activity of Brg1 and the expression of TGF-ß1 induced by Ang II in cultured neonatal rat cardiomyocytes and cardiac fibroblasts, respectively, through NF-κB pathway. CONCLUSIONS: These results suggested that PPARγ activation effectively inhibited cardiac remodeling processes by suppression of Brg1 and TGF-ß1 expressions through NF-κB pathway in the pressure-overloaded hearts induced by abdominal aorta ligation in rats.

Speciation of inorganic selenium in environmental water samples by inductively coupled plasma optical emission spectrometry after preconcentration by using a mesoporous zirconia coating on coal cinder.

A simple, novel, and selective flow-injection solid-phase extraction with inductively coupled plasma optical emission spectrometry method was developed for the speciation of inorganic selenium in environmental water samples. A mesoporous zirconia film was simply introduced to coat coal cinder by means of the sol-gel technique, and the adsorptive performance of the coated material for Se(IV)/Se(VI) was investigated in different media. Both Se(IV) and Se(VI) can be retained quantitatively by the material in HCl/NaOH (pH 1.0-9.0) media, while only Se(IV) was adsorbed quantitatively in sodium acetate buffer (pH 3.5-6.0). Thus, the assay of Se(VI) is based on subtracting Se(IV) from total selenium by controlling different adsorptive media without employing any redox procedure. Under the optimum conditions, the detection limit of Se(IV) is 9.0 ng/L with an enrichment factor of 100, and the relative standard deviation is 3.6% (n = 9, C = 5.0 ng/mL). The developed method was successfully applied to the speciation of inorganic selenium in environmental water samples with satisfactory results. In order to further verify the accuracy of the developed method, it was applied to analysis of total selenium in GSBZ 50031-94 certified reference environmental water, and the determined values coincided with the certified values very well.