Application of MALDI-TOF mass spectrometry for identification of Nocardia species.

BACKGROUND: Nocardiosis, despite its rarity and underreporting, is significant due to its severe impact, characterized by high morbidity and mortality rates. The development of a precise, reliable, rapid, and straightforward technique for identifying the pathogenic agent in clinical specimens is crucial to reduce fatality rates and facilitate timely antimicrobial treatment. In this study, we aimed to identify Nocardia spp. in clinical isolates, using MALDI-TOF MS as the primary method, with molecular methods as the gold standard. Clinical Nocardia isolates were identified using 16S rRNA/hsp65/gyrB/secA1/rpoB gene sequencing. Identification performance of the Bruker MALDI Biotyper 3.1 (V09.0.0.0_8468) and MBT Compass 4.1 (V11.0.0.0_10833) for Nocardia identification was evaluated. RESULTS: Seventy-six Nocardia isolates were classified into 12 species through gene sequencing. The MALDI Biotyper 3.1 (V09.0.0.0_8468) achieved 100% genus-level accuracy and 84.2% species accuracy (64/76). The MBT Compass 4.1 with the BDAL Database (V11.0.0.0_10833) improved species identification to 98.7% (75/76). The updated database enhanced species level identification with scores > 1.7, increasing from 77.6% (59/76) to 94.7% (72/76), a significant improvement (P = 0.001). The new and simplified extraction increased the proportion of strains identified to the species level with scores > 1.7 from 62.0% (18/29) to 86.2% (25/29) (P = 0.016). An in-house library construction ensured accurate species identification for all isolates. CONCLUSIONS: The Bruker mass spectrometer can accurately identify Nocardia species, albeit with some variations observed between different database versions. The MALDI Biotyper 3.1 (V09.0.0.0_8468) has limitations in identifying Nocardia brasiliensis, with some strains only identifiable to the genus level. MBT Compass 4.1 (V11.0.0.0_10833) effectively addresses this shortfall, improving species identification accuracy to 98.7%, and offering quick and reliable identification of Nocardia. Both database versions incorrectly identified the clinically less common Nocardia sputorum as Nocardia araoensis. For laboratories that have not upgraded their databases and are unable to achieve satisfactory identification results for Nocardia, employing the new and simplified extraction method can provide a degree of improvement in identification outcomes.

Evaluation of a Cryptococcus capsular polysaccharide detection FungiXpert LFA (lateral flow assay) for the rapid diagnosis of Cryptococcosis.

Cryptococcus is an opportunistic pathogenic fungus and is the major cause of fungal meningitis. The cryptococcal antigen (CrAg) lateral flow assay (LFA) is an immunochromatographic test system that has simplified diagnosis as a point-of-care test. In this study, we evaluated the diagnostic performance of Cryptococcal capsular polysaccharide detection FungiXpert (Genobio Pharmaceutical, Tianjin, China) using serum and cerebrospinal fluid (CSF) samples for the diagnosis of cryptococcosis and investigated the cross-reaction of the assays to pathogenic fungi and bacterium by comparing it to the U.S. Food and Drug Administration (US FDA)-approved IMMY CrAg LFA. Eighty CSF and 119 serum/plasma samples from 158 patients were retrospectively collected to test for qualitative or semi-quantitative detection of CrAg. Cross-reaction of the assays was tested using 28 fungi and 1 bacterium. Compared to IMMY CrAg LFA, the FungiXpert LFA demonstrated 99.1% sensitivity and 98.9% specificity in the qualitative test. In the 96 semi-quantitative CrAg assay results, 39 (40.6%) test titers of FungiXpert LFA were 1-2 dilutions higher than those of IMMY CrAg LFA. The Intraclass Correlation Coefficient of the Semi-quantitative results of CrAg titer tests via the two assays was 0.976. Similar to IMMY CrAg LFA, FungiXpert LFA showed cross-reactivity with Trichosporon asahii. Compared with the IMMY CrAg LFA, the FungiXpert LFA showed an equal, yet, excellent performance. However, it is important to note that these two assays have potential cross-reactivity to T. asahii when diagnosing patients. FungiXpert LFA is a rapid screening method for the effective and practical diagnosis and treatment of cryptococcosis. LAY SUMMARY: The FungiXpert LFA was developed to diagnose fungal meningitis caused by Cryptococcus yeasts, by using serum or cerebrospinal fluid. It was compared to an existing lateral flow assay (LFA). The FungiXpert LFA performed well in qualitative and semi-quantitative tests.

Molecular epidemiology and antifungal susceptibilities of Cryptococcus species isolates from HIV and non-HIV patients in Southwest China.

To investigated the molecular epidemiology and in vitro antifungal susceptibility of Cryptococcus isolates from West China Hospital from HIV and non-HIV patients between 2009 and 2015. A total of 132 C. neoformans and C. gattii were subjected to antifungal susceptibility testing by E-test method. Among the 132 isolates, 42 C. neoformans and C. gattii were analyzed by mating type and URA5-RFLP. A total of 113 C. neoformans and C. gattii were subjected to multi-locus sequence typing (MLST). MLST results revealed that ST5 was the major molecular type. The wild-type (WT) phenotype was seen in 91.5-100% of C. neoformans isolates for amphotericin B, 5-flucytosine, fluconazole, and voriconazole. However, 72.3% (94/130) of C. neoformans isolates were non-wild-type (non-WT) to itraconazole by E-test method. In the sixth study year, the geometric mean, MIC50 and MIC90 of fluconazole were the highest (P < 0.001). Among 132 patients. 52 were coinfected with HIV and 80 were HIV-negative. Isolates from HIV and non-HIV patients showed no differences in susceptibility to amphotericin B (P = 0.544), 5-flucytosine (P = 0.063), fluconazole (P = 0.570), voriconazole (P = 0.542), and itraconazole (P = 0.787). Our study showed that Cryptococcus in southwest China showed a low degree of genetic diversity. The increased MIC values of fluconazole are noted. Cryptococcus isolates from HIV and non-HIV patients have shown no differences in susceptibility to five antifungal agents.

Associations between meteorological variation and rupture of intracranial aneurysm in Fujian, China: A 5-year multicenter study.

OBJECTIVE: By exploring the exposure-response relationships between meteorological factors and rupture of intracranial aneurysm (IA) to reveal the influence of meteorological variation on IA rupture under the specific climate in Fujian, China. METHOD: 7515 cases of IA rupture from several municipal medical institutions in Fujian Province as well as local meteorological data during the same period were collected from 2013 to 2017. Poisson regression and Spearman correlation analysis were applied to explore the distribution characteristics of IA rupture and how it is associated with meteorological parameters. Poisson generalized additive model was established to further analyze the exposure-response relationships between meteorological factors and IA rupture, and its hysteresis effects. RESULT: The IA rupture exhibited a negative correlation with temperature (rs = -0.323, 95% CI: -0.539 ~ -0.068) and a positive correlation with atmospheric pressure (rs = 0.397, 95% CI: 0.152-0.597) or pressure difference (rs = 0.296, 95% CI: 0.038-0.517), 21.05 â„ƒ and 1000.14 hPa were the risk thresholds for the onset ascribed to variation in temperature and atmospheric pressure, respectively. Temperature and atmospheric pressure also exerted hysteresis effects on IA rupture. Cold will increase the rupture risk in the subsequent 1-3 days, and high pressure will raise the morbidity in the next 1-2 days. Besides, drastic variations in temperature and atmospheric pressure were also associated with the higher risk of IA rupture in the next 2 days and 1 day, respectively. CONCLUSION: Temperature and atmospheric pressure have a negative and positive correlation with IA rupture in Fujian, China, respectively. Variation in temperature and atmospheric pressure exert different degrees of hysteresis effects on IA rupture.

[Galactomannan Tests of Bronchoalveolar Lavage Fluid for Diagnosing Invasive Pulmonary Aspergillosis].

OBJECTIVE: To determine the value of galactomannan (GM) in bronchoalveolar lavage fluid (BALF) for diagnosing invasive pulmonary aspergillosis. METHODS: According to the European Organization for Research and Treatment of Cancer / Invasive Fungal Infection Group (EORTC / IFICG) and the American Mycosis Research Group (MSG),and the American College of Infectious Diseases (IDSA) guidelines,295 patients with pulmonary aspergillosis (IPA) and high risk of invasive infections were divided into four groups: IPA group (42 cases),clinically diagnosed group (68 cases),suspected group (61 cases),and non-IPA group (124 cases). Their serum and BALF concentrations of GM were detected by enzyme-linked immunosorbent assay (ELISA).The clinically diagnosed and confirmed invasive pulmonary fungal infections (IPFI) were treated as golden standards (+). A GM value ≥ proposed threshold was deemed diagnostic test positive. Receiver operating characteristic (ROC) curves were drawn to determine the diagnostic efficiency of BALF GM assay for IPFI. The optimal cut-off point of BALF GM was determined using Youden index. RESULTS: BALF GM had an area under the curve (AUC) of 0.932 in diagnosing IPFI,with 87.5% sensitivity, 96.7% specificity, 87.5% positive predictive value,and 96.7% negative predictive value when the BALF GM value was set at 1.5 ng/mL as the optimal cut-off point. Higher BALF and serum GM values were found in the confirmed IPA group,followed by the clinical diagnosed group compared with the non-IPA group ( P<0.05). The threshold value was set at 0.5 ng/mL for serum GM and 1.5 ng/mL for bronchoalveolar lavage GM. Higher positive rates were found in the confirmed IPA group and the clinical diagnosed group compared with the non-IPA group ( P<0.05). Serum GM appeared to have higher false positives and false negative rates. CONCLUSION: BALF GM is a rapid and accurate indicator with high sensitivity and specificity for the early diagnosis of IPA.

[Antibiotic Resistance and Risk Factors for Mortality of Blood Stream Infections (BSIs) with Escherichia coli in Patients with Hematological Malignancies].

OBJECTIVE: To analyze the risk factors for mortality of blood stream infections (BSIs) caused by Escherichia coli in the patients with hematological malignancies. METHODS: There were 110 Escherichia coli BSIs patients with hematological malignancies included in recent five years. Among them,77 cases had BSIs caused by extended-spectrum-beta-lactamase (ESBL)-producing Escherichia coli (ESBL-EC group),while 33 cases had BSIs with non-ESBL-producing Escherichia coli (non-ESBL-EC group). The antibiotic resistance and clinical features were compared between the two groups,and the risk factors for death within 30 d were analyzed. RESULTS: Less than 10% of the isolates were resistant to carbapenems and amikacin. Between ESBL-EC group and non-ESBL-EC group,the clinical symptoms,prior use of antibiotics or antifungal agents,risk factors for infection,30 d mortality rates were not significantly different (P>0.05). A logistic regression analysis confirmed that non remission of hematologic malignancies (odds ratio=9.575,95% confidence interval 1.546-59.312,P=0.015) and inappropriate initial antibiotic therapy (odds ratio=8.806,95% confidence interval 1.527-50.772, P=0.015) were independent risk factors for 30 d mortality. CONCLUSION: The use of effective antimicrobial treatment as early as possible could reduce the risk of death for hematological malignancies patients suffering Escherichia coli BSIs.

[Etiology, Prognosis and Risk Factors of 181 Adult Community-acquired Acute Bacterial Meningitis].

OBJECTIVE: To understand the etiology, clinical prognosis and risk factors of adult community-acquired acute bacterial meningitis (ABM) and provide the evidence for clinical diagnosis and treatment. METHODS: We performed a retrospective study of 181 clinically diagnosed hospitalized patients with community-acquired adult ABM from Jan.2010 to Jan.2018. The patients were categorized as non-elderly (16≤age<65 years old, n=156 ) and elderly (age≥65 years old, n=25) group. The etiology, clinical features, prognosis and risk factors of the two groups were compared. RESULTS: Sixty-four of 181 patients (35.4%) had pathogens detected. The most common pathogens were Streptococcus pneumoniae (17.9%), Listeria monocytogenes (13.4%) and Klebsiella pneumoniae (10.5%). The mortality of the elderly group was higher than that of the non-elderly group (P<0.05). Univariate analysis showed that there was a significant difference between the elderly group and the non-elderly group in the incidence of hypertension, hypokalemia, pulmonary infection, ear-nose-throat ( ENT) infection, cerebrospinal fluid (CSF) protein concentration, head CT abnormalities and mortality. Logistic regression analysis showed that pulmonary infection and temperature ≥38.5 ℃ were independent risk factors for poor prognosis in the non-elderly group. CSF pressure ≥200 mmH2O was a independent risk factors for poor prognosis in the elderly group. CONCLUSION: The pathogens that cause acute bacterial meningitis in adult community are mainly Streptococcus pneumoniae, Listeria monocytogenes and Klebsiella pneumoniae.Pulmonary infection and temperature ≥38.5 ℃ are independent risk factors of poor prognosis in the non-elderly patients, as CSF pressure ≥200 mmH2O a independent risk factor in the elderly patients.

Different characteristics of cryptococcal meningitis between HIV-infected and HIV-uninfected patients in the Southwest of China.

Cryptococcus is the major pathogen that causes fungal meningitis. In the People's Republic of China, especially in the Southwest area, cryptococcal meningitis (CM) in HIV-uninfected patients is more common than in HIV-infected patients. We compared clinical features and laboratory data pertaining to CM in patients with different immunological statuses. Demographic data, clinical manifestations, and laboratory data from inpatients in West China Hospital Sichuan University were collected from June 2009 to June 2014. Patients were grouped according to HIV status. Continuous variables were evaluated by Student t-test or Wilcoxon rank sum tests. Categorical variables were analyzed by χ2 test. Among 85 patients with CM were identified, 53 (62.4%) were HIV-uninfected patients. CM occurred more frequently in males in the HIV-infected group. Compared with HIV-infected patients, HIV-uninfected patients had more leukocytes in their blood and more leukocytes and protein in cerebrospinal fluid. More HIV-uninfected patients had increased cerebrospinal fluid (CSF)/serum albumin ratios, while intrathecal immunoglobulin G (IgG) synthesis was significantly increased. The rate of in-hospital mortality of HIV-infected CM patients was higher. Clinical signs are similar between HIV-uninfected and HIV-infected CM patients. Fewer leukocytes and protein was detected in the CSF and lower local synthesis of IgG in the central nervous system in HIV-infected patients, which reflects their diminished immune response. These characteristics should be noted in order to avoid misdiagnosis. Meningeal enhancement and intrathecal IgG synthesis in the HIV-uninfected group was significantly higher, that may be performance of aggressive inflammatory response and might contribute to a better outcome.

Molecular characterisation of clinical Cryptococcus neoformans and Cryptococcus gattii isolates from Sichuan province, China.

Previous reports on the molecular characteristics of clinical isolates of Cryptococcus species in China have focused on isolates from southeast China. To obtain a more detailed molecular epidemiology, a total of 92 cryptococcal isolates were collected from Sichuan province. A total of 24 isolates from 12 other provinces were collected for comparative study. Genotypes and mating types of 116 Cryptococcus isolates were determined. Among the 116 isolates, 43 isolates (19 isolates from Sichuan and 24 isolates outside of Sichuan) were analysed by multi-locus sequence typing (MLST). All 116 clinical isolates were mating type α. Most isolates (114/116) were molecular type VNI and the remaining two isolates were VGI and VGII respectively. MLST results revealed five sequence types (STs) of C. neoformans including two novel STs, with most isolates identified as ST5. The two C. gattii isolates identified in our study were ST44 and ST159. Based on our report and previous studies, there are 15 C. neoformans STs in China which can be divided into three subgroups. The C. gattii isolate from Sichuan could be a scattered subtype of VGII (ST44). Our findings demonstrated that C. neoformans isolates in Sichuan are genetically homogeneous, and ST5 is the epidemic clone of C. neoformans in China.

Targeting Mitochondrial Dysfunction With LncRNAs in a Wistar Rat Model of Chronic Obstructive Pulmonary Disease.

BACKGROUND/AIM: Chronic obstructive pulmonary disease (COPD) has become a prominent healthcare issue in recent years. Cigarette smoking (CS) and fine particulate matter (PM2.5) are important causative factors for COPD. This study assessed the aberrant lncRNA profiles in the tissue of rats with COPD caused by CS or PM2.5 Materials and Methods: A COPD rat model was developed using CS (CSM) or PM2.5 (PMM), and lung tissue RNA was extracted. The Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) were used to investigate the correlations between the distinct lncRNAs and mRNA pathways. A coding-non-coding gene co-expression network (CNC) was constructed by establishing connections between differentially expressed long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) associated with mitochondrial dysfunction and the inflammatory response. RESULTS: A quantitative real-time reverse transcription PCR (qRT-PCR) experiment was performed to verify the expression of the particular lncRNAs. Microarray analysis of lung tissue from the COPD model revealed that 123 and 444 lncRNAs were substantially raised and reduced in PMM vs. the control group (Ctrl), respectively, as were 621 and 1,178 mRNAs. Meanwhile, 81 and 340 lncRNAs were consistently raised and lowered in CSM vs. Ctrl, respectively, as were 408 and 931 mRNAs. GO enrichment and KEGG pathway analysis indicated that the COPD model was connected to inflammatory responses, mitochondrial dysfunction, and others. CONCLUSION: XR_340674, ENSRNOT00000089642, XR_597045, and XR_340651 were decreased, and XR_592469 was elevated. These lncRNAs were shown to be related to mitochondrial dysfunction in the lung tissue of animals exposed to CS or PM2.5.

Prognostic factors affecting the ruptured intracranial aneurysms: A 9-year multicenter study in Fujian, China.

BACKGROUND: A multicenter retrospective study was conducted to explore the factors affecting short-term prognosis and long-term outcomes of intracranial aneurysms (IA) rupture. Further, the prognosis prediction model was constructed based on survival analysis, contributing to the development of prevention strategies for aneurysmal subarachnoid hemorrhage. METHODS: Data of 1280 patients with IA rupture were gathered between 2014 and 2022 in Fujian, China. Logistic regression was implemented to study the short-term prognostic factors of IA rupture. Survival analysis of 911 patients among them was performed to explore the long-term outcome status by Cox risk assessment. Nomogram prognosis models were constructed using R software. RESULTS: The findings displayed that blood type O (OR = 1.79; P = 0.019), high systolic pressure (OR = 1.01; P < 0.001), Glasgow Coma score (GCS) 9-12 (OR = 2.73; P = 0.022), GCS < 9 (OR = 3.222; P = 0.006), diabetes (OR = 2.044; P = 0.040), and high white blood cell count (OR = 1.059, P = 0.040) were core influencing factors for poor short-term prognosis. Survival analysis revealed that age > 60 years (HR = 2.87; P = 0.001), hypertension (HR = 1.95; P = 0.001), conservative (HR = 6.89; P < 0.001) and endovascular treatment (HR = 2.20; P = 0.001), multiple ruptured IAs (HR = 2.37; P = 0.01), Fisher 3 (HR = 1.68; P = 0.09), Fisher 4 (HR = 2.75; P = 0.001), and Hunt-Hess 3 (HR = 0.55; P = 0.05) were the major risk factors for terrible long-term outcomes. CONCLUSIONS: People over 60 years with characteristics of type O blood, high systolic pressure, diabetes, high white blood cell count, and onset GCS < 12 will have more complications and a worse short-term prognosis. Those aged > 60 years with hypertension, conservative and endovascular treatment, multiple ruptured IAs, Fisher ≥ 3 and Hunt-Hess 3 have a greater risk of poor long-term prognosis.

The mediating and moderating role of personal strain and coping resource in the relationship between work stressor and quality of life among Chinese nurses.

OBJECTIVE: To determine whether personal strain and coping resources act as either mediator or moderator or both in the relationship between work stressor and quality of life among Chinese nurses. METHODS: A total of 1,012 nurses were selected from eight hospitals located in two provinces in China. Quality of life was measured with the Chinese version of the Short Form-36 Health Survey; work stressor, personal strain, and coping resources were evaluated using the Occupation Stress Inventory-Revised Edition. The hierarchical multiple regression procedure and Baron and Kenny's model of mediation were applied to test for moderation and mediation, respectively. A structural equation model was fit to assess the interrelationships among these variables. RESULTS: Work stressor was closely associated with quality of life, which was mediated and moderated by personal strain and coping resources. Personal strain also acted both as moderator and mediator in the relationship between coping resources and quality of life. The relationships were verified in the structural equation model. The greatest absolute value of the standardized total effects was seen in personal strain (0.817), followed by work stressor (0.634) and coping resources (0.488). CONCLUSIONS: Personal strain and coping resources have both mediating and moderating effects on the relationship between work stress and quality of life in a sample of Chinese nurses. An effective intervention strategy is needed to reduce work stress and ensure better quality of life.

Identification of the Potential Molecular Mechanism of TGFBI Gene in Persistent Atrial Fibrillation.

Background: Transforming growth factor beta-induced protein (TGFBI, encoded by TGFBI gene), is an extracellular matrix protein, widely expressed in variety of tissues. It binds to collagens type I, II, and IV and plays important roles in the interactions of cell with cell, collagen, and matrix. It has been reported to be associated with myocardial fibrosis, and the latter is an important pathophysiologyical basis of atrial fibrillation (AF). However, the mechanism of TGFBI in AF remains unclear. We aimed to detect the potential mechanism of TGFBI in AF via bioinformatics analysis. Methods: The microarray dataset of GSE115574 was examined to detect the genes coexpressed with TGFBI from 14 left atrial tissue samples of AF patients. TGFBI coexpression genes were then screened using the R package. Using online analytical tools, we determined the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, Gene Ontology (GO) annotation, and protein-protein interaction (PPI) network of TGFBI and its coexpression genes. The modules and hub genes of the PPI-network were then identified. Another dataset, GSE79768 was examined to verify the hub genes. DrugBank was used to detect the potential target drugs. Results: In GSE115574 dataset, a total of 1818 coexpression genes (769 positive and 1049 negative) were identified, enriched in 120 biological processes (BP), 38 cellular components (CC), 36 molecular functions (MF), and 39 KEGG pathways. A PPI-network with average 12.2-degree nodes was constructed. The genes clustered in the top module constructed from this network mainly play a role in PI3K-Akt signaling pathway, viral myocarditis, inflammatory bowel disease, and platelet activation. CXCL12, C3, FN1, COL1A2, ACTB, VCAM1, and MMP2 were identified and finally verified as the hub genes, mainly enriched in pathways like leukocyte transendothelial migration, PI3K-Akt signaling pathway, viral myocarditis, rheumatoid arthritis, and platelet activation. Pegcetacoplan, ocriplasmin, and carvedilol were the potential target drugs. Conclusions: We used microdataset to identify the potential functions and mechanisms of the TGFBI and its coexpression genes in AF patients. Our findings suggest that CXCL12, C3, FN1, COL1A2, ACTB, VCAM1, and MMP2 may be the hub genes.

A glutamatergic basal forebrain to midbrain circuit mediates wakefulness and defensive behavior.

Defensive behavior, a group of responses that evolved due to threatening stimuli, is crucial for animal survival in the natural environment. For defensive measures to be timely and successful, a high arousal state and immediate sleep-to-wakefulness transition are required. Recently, the glutamatergic basal forebrain (BF) has been implicated in sleep-wake regulation; however, the associated physiological functions and underlying neural circuits remain unknown. Here, using in vivo fiber photometry, we found that BF glutamatergic neuron is activated by various threatening stimuli, including predator odor, looming threat, sound, and tail suspension. Optogenetic activation of BF glutamatergic neurons induced a series of context-dependent defensive behaviors in mice, including escape, fleeing, avoidance, and hiding. Similar to the effects of activated BF glutamatergic cell body, photoactivation of BF glutamatergic terminals in the ventral tegmental area (VTA) strongly drove defensive behaviors in mice. Using synchronous electroencephalogram (EEG)/electromyogram (EMG) recording, we showed that photoactivation of the glutamatergic BF-VTA pathway produced an immediate transition from sleep to wakefulness and significantly increased wakefulness. Collectively, our results clearly demonstrated that the glutamatergic BF is a key neural substrate involved in wakefulness and defensive behaviors, and encodes these behaviors through glutamatergic BF-VTA pathway. Overexcitation of the glutamatergic BF-VTA pathway may be implicated in clinical psychiatric diseases characterized by exaggerated defensive responses, such as autism spectrum disorders.

[Induction of cell damage and change of miR-133b expression by paraquat in PC12 cells].

OBJECTIVE: To investigate the effect of paraquat on induction of cell damage and miR-133b expression in PC12 cells. METHODS: Cytotoxicity of PC12 cells was measured by MTT assay, following the PC12 cells treatment with 50, 100, or 300 µmol/L paraquat. Cell apoptosis was examined by the method of Annexin V-FITC/PI in flow cytometry (FCM) and the relative level of miR-133b expression was measured by real time RT-PCR, following the PC12 cells treatment with 100 or 300 µmol/L paraquat. RESULTS: Survival rate of PC12 cells treated with 100 or 300 µmol/L paraquat was lower than that of the vehicle control group (P < 0.01, P < 0.05), in the dose dependent pattern. Apoptotic rate of PC12 cells treated with 100, 300 µmol/L paraquat was higher than that of the vehicle control group (P < 0.05). The relative level of miR-133b expression of PC12 cells treated with 300 µmol/L paraquat was higher than that of the vehicle control group (P < 0.05). CONCLUSIONS: Paraquat may cause cell damage and induce apoptosis in PC12 cells, and induce miR-133b expression.

[Effects of the workplace violence on the sub-health status of nurses].

OBJECTIVE: To explore the effects of workplace violence on sub-health status of nurses and to provide the theoretical basis for preventing the workplace violence in the hospitals and improving the health status of nurses. METHODS: A total of 679 nurses were selected by using stratified cluster sampling method. The Chinese version of workplace violence scale (WVS) and sub-health scale were used to measure workplace violence and sub-health status, respectively. RESULTS: The subjects with middle age (30-45 years) were found to have the highest incidence of physical assault (24.5%) and emotional assault (52.2%) as compared with other subjects (P<0.05). The prevalence (23.6%) of emotional assault of subjects with lowest education levels was significantly lower than that of others (P<0.05). The nurses with work shift were more vulnerable to emotional assault (45.1%) than those without work shift (36.8%)(P<0.05). The prevalence of the workplace violence of nurses in the psychiatric department and emergency department was significantly higher than that of nurses in other departments (P<0.05). The results of multivariate analysis showed that workplace violence was an important risk factor for sub-health status of nurses when other potential confounding factors were taken into account. CONCLUSION: The results of present study showed that workplace violence plays an important role in sub-health status of nurses after adjusting other potential confounding factors. It is important to develop the prevention strategies for reducing the incidence of workplace violence and improving the sub-health status of nurses.

[Antagonism of tert-butylhydroquinone on neurotoxicity and oxidative stress induced by paraquat in PC12].

OBJECTIVE: To investigate the protective effects of the tert-butylhydroquinone (tBHQ) pretreatment on neurotoxicity and oxidative stress induced by paraquat (PQ) in PC12 cells. METHODS: Cytotoxicity of PC12 cells was measured by MTT assay, following the PC12 cells treatment with different concentrations of 100, 300 micromol/L PQ for 24 h and 48 h. PC12 cells were pretreated with or without 40 micromol/L tBHQ for 4 h, PC12 cells were exposed to PQ at the doses of 0, 100, 300 micromol/L for 24 h and 48 h, respectively. The viability of PC12 cells was measured by MTT assay, the apoptosis rates of PC12 cells were detected by flow cytometry (FCM) and the malondialdehyde (MDA) levels of PC12 cells were examine by thiobarbituric acid (TBA) method. RESULTS: When the exposure doses of PQ were 100 and 300 micromol/L for 24 h, the viability of PC12 cells pretreated with tBHQ was significantly higher than that of PC12 cells only exposed to PQ (P < 0.05 or P < 0.01). When the exposure dose of PQ was 100 micromol/L for 48 h, the viability of PC12 cells pretreated with tBHQ was significantly higher than that of PC12 cells only exposed to PQ (P < 0.01). When the exposure doses of PQ were 100 and 300 micromol/L for 24 h, the apoptosis rates and MDA levels of PC12 cells pretreated with tBHQ were significantly lower than those of PC12 cells only exposed to PQ (P < 0.05 or P < 0.01). CONCLUSIONS: tBHQ pretreatment can reduce the cytotoxicity, apoptosis and oxidative stress induced by PQ in PC12 cells.

Weekday and weekend sleep deprivation are associated with recurrent nightmare in adolescents: a cross-sectional study.

OBJECTIVE: Our study aimed to investigate the association between sleep deprivation and parasomnias including nightmare and sleepwalking in Chinese adolescents. METHODS: A total of 19,229 high school students aged 10-20 in Fuzhou were invited to complete questionnaires regarding sleep duration, parasomnias including nightmare and sleepwalking, and emotional problems. Subjects with sleep deprivation (SD) defined as sleeping less than 8 h either on weekdays or on weekends were categorized as three groups: weekday SD, weekend SD and habitual SD. RESULTS: The prevalence of recurrent nightmare was significantly higher for subjects with SD (SD vs non sleep deprivation (NSD): 7.6% vs 3.7%). In all subjects, habitual SD was associated with the highest risk of recurrent nightmare [Odds ratio (OR) = 2.19, 95% Confidential interval (95% CI) = 1.73-2.75, P < 0.001], followed by weekday SD (OR = 2.06, 95% CI = 1.64-2.61, P < 0.001) and weekend SD (OR = 1.45, 95% CI = 1.01-2.08, P = 0.045). No significant association was found between sleepwalking and sleep deprivation. In further age-based (10-13/14-17 years) and sex-based subgroup analyses, the findings were consistent except that association between weekend SD and recurrent nightmare disappeared among subjects aged 14-17 or among girls. CONCLUSIONS: Our study found a significant association between recurrent nightmare and sleep deprivation either on weekdays or on weekends in adolescents, which was stronger with more deprivation episodes. No significant association was found between sleepwalking and sleep deprivation. Association between weekend SD and recurrent nightmare disappeared among subjects aged 14-17 or among girls.

[Effect of deltamethrin on production of free radical and transcription factor Nrf2 in rats' brain tissue].

OBJECTIVE: To explore the effect of deltamethrin (DM) on production of free radical and transcription factor Nrf2 in rats' brain tissue. METHODS: 8 male rats were randomly assigned to four groups and administered with 1% W/W tertiary butylhydroquinone (tBHQ) or olive oil for 3 days, prior to exposure to DM and then with 12.50 mg or 0mg DM/Kg BW for 5 days. The level of free radical in rats' hippocampus tissue was detected by electron spin resonance (ESR) spectroscopy. 18 male rats were randomly assigned to three groups and administered with i.p. (daily dose was respectively 0, 3.13, 12.50 mg/kg DM) for five days. After treatment, Nrf2 protein levels in the cytoplasmic and nuclear fractions of both cerebral cortex and hippocampus tissue were measured by western blot. RESULTS: The level of free radical in hippocampus tissue of rats administered by DM and pretreatment with tBHQ prior to DM were increased to a 2.45-fold and 2.97-fold of values of control group, respectively (P < 0.05). Nrf2 protein levels in the cytoplasmic fractions of cerebral cortex of both low and high dose group were significantly increased, 1.68- fold and 1.34- fold of values of control group, respectively. Nrf2 protein levels in the nuclear fractions of cerebral cortex of both low and high dose group were increased in a dose- dependent model, 1.51-fold and 2.29-fold of values of control group, respectively (P < 0.01). Nrf2 protein levels in the cytoplasmic fractions of hippocampus tissue of both low and high dose group were increased in a dose- dependent model, 2.26-fold and 3.58-fold of values of control group, respectively. Nrf2 protein levels in the nuclear fractions of hippocampus tissue of both low and high dose group were increased, 2.42-fold and 2.45-fold of values of control group, respectively (P < 0.01). CONCLUSION: The studies in vivo demonstrate that DM treatment could induce free radical production and expression of Nrf2 protein in both cerebral cortex and hippocampus tissue and activate Nrf2.

[Protective effect of tert-butylhydroquinone on PC12 cells from neurotoxicity induced by manganese in vitro].

OBJECTIVE: To investigate the protective effect of the tert-butylhydroquinone (tBHQ) on PC12 cells from neurotoxicity induced by manganese. METHODS: Cytotoxicity of PC12 cells was measured by MTT assay, following the PC12 cells treatment with different concentrations of MnCl2 (300, 600, 900 µmol/L) for 24, 48 or 72 h. PC12 cells were pretreated with 40 µmol/L tBHQ for 12 h, followed by the treatment of 600 micromol/L or 300 µmol/L MnCl2 for 72 h. Cytotoxicity of PC12 cells was measured by MTT assay, and cell apoptosis was examined by the method of Annexin V-FITC/PI in flow cytometry (FCM). RESULTS: The proliferation of PC12 cells treated with 300, 600, 900 µmol/L MnCl2 was suppressed in the dose dependent pattern (P < 0.01). Proliferation of PC12 cells treated with 600 µmol/L MnCl2 was suppressed to 40% of that in control group (P < 0.01), but the proliferation rate of PC12 cell pretreated with 40 µmol/L tBHQ was 180% of that in control group (P < 0.01). Apoptotic rate of PC12 cells treated with 300 micromol/L MnCl2 was higher than the vehicle control group (P < 0.01). Apoptotic rate of 40 µmol/L tBHQ pretreatment followed by 300 µmol/L MnCl2 treatment was lower than that of MnCl2 treatment group (P < 0.01). The inhibition rate of apoptosis was 61%. CONCLUSIONS: Manganese may suppress PC12 cells proliferation and induce apoptosis. tBHQ can reduce PC12 cells proliferation suppressed by manganese and attenuate the apoptosis induced by manganese.