Sociodemographic, clinical and treatment characteristics of current rapid-cycling bipolar disorder: a multicenter Chinese study

BACKGROUND

Rapid cycling bipolar disorder (RCBD), characterized by four or more episodes per year, is a complex subtype of bipolar disorder (BD) with poorly understood characteristics.

METHOD

This multicenter, observational, longitudinal cohort study enrolled 520 BD patients across seven psychiatric institutions in China from January 2013 to January 2014. Participants were divided into RCBD and non-RCBD (NRCBD) groups based on the frequency of mood episodes in the preceding year. Data collection utilized a standardized form, supplemented by a medical record review, focusing on sociodemographic, clinical, and treatment characteristics. Statistical analysis involved independent samples t-tests, Kruskal-Wallis H tests, Chi-square or Fisher's exact tests, with Bonferroni correction applied to account for multiple comparisons, and multivariable logistic regression to identify characteristics associated with RCBD.

RESULTS

Among the BD cohort, 9.4% were identified as current RCBD. Compared to NRCBD, RCBD patients had a shorter duration from the first psychiatric consultation to the diagnosis of BD, a reduced duration of their longest period of euthymia, a lower proportion of lifetime hospitalization history due to BD, and less use of electroconvulsive therapy (ECT) within the last 12 months. Additionally, they presented higher baseline scores on the Mood Disorder Questionnaire (MDQ) and the Brief 16-item Quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR16). However, after applying the Bonferroni correction, these differences were not statistically significant. Multivariable logistic regression analysis identified three factors that were independently associated with RCBD: time from first psychiatric consultation to BD diagnosis (Odds Ratio [OR] = 0.512, P = 0.0416), lifetime hospitalization history due to BD (OR = 0.516, P = 0.0476), and ECT treatment within the past 12 months (OR = 0.293, P = 0.0472).

CONCLUSION

This study revealed that the duration from first psychiatric consultation to BD diagnosis, lifetime hospitalization history due to BD, and ECT treatment in the past year were associated with RCBD. Recognizing these factors could contribute to enhance the early identification and clinical outcomes of RCBD. Trial Registration Number Registry ClinicalTrials.gov NCT01770704. Date of Registration: First posted on January 18, 2013.

Clinicodemographic correlates of psychotic features in bipolar disorder - a multicenter study in China

BACKGROUND

Psychotic symptoms are prevalent in patients with bipolar disorder (BD). However, nearly all previous studies on differences in sociodemographic and clinical factors between patients with (BD P +) and without (BD P-) psychotic symptoms were conducted in Western populations, and limited information is known in China.

METHOD

A total of 555 patients with BD from seven centers across China were recruited. A standardized procedure was used to collect patients' sociodemographic and clinical characteristics. The patients were divided into BD P + or BD P- groups based on the presence of lifetime psychotic symptoms. Mann-Whitney U test or chi-square test was used to analyze differences in sociodemographic and clinical factors between patients with BD P + and BD P-. Multiple logistic regression analysis was conducted to explore factors that were independently correlated with psychotic symptoms in BD. All the above analyses were re-conducted after the patients were divided into BD I and BD II group according to their types of diagnosis.

RESULTS

A total of 35 patients refused to participate, and the remaining 520 patients were included in the analyses. Compared with patients with BD P-, those with BD P + were more likely to be diagnosed with BD I and mania/hypomania/mixed polarity in the first mood episode. Moreover, they were more likely to be misdiagnosed as schizophrenia than major depressive disorder, were hospitalized more often, used antidepressants less frequently, and used more antipsychotics and mood stabilizers. Multivariate analyses revealed that diagnosis of BD I, more frequent misdiagnosis as schizophrenia and other mental disorders, less frequent misdiagnosis as major depressive disorder, more frequent lifetime suicidal behavior, more frequent hospitalizations, less frequent use of antidepressants, more frequent use of antipsychotics and mood stabilizers were independently correlated with psychotic symptoms in BD. After dividing the patients into BD I and BD II groups, we observed notable differences in sociodemographic and clinical factors, as well as clinicodemographic correlates of psychotic features between the two groups.

CONCLUSIONS

Differences in clinical factors between patients with BD P + and BD P- showed cross-cultural consistency, but results on the clinicodemographic correlates of psychotic features were not. Notable differences between patients with BD I and BD II were found. Future work exploring the psychotic features of BD needs to take types of diagnosis and cultural differences into consideration.

TRIAL REGISTRATION

This study was first registered on the website of the ClinicalTrials.gov ( https://clinicaltrials.gov/ ) on 18/01/2013. Its registration number is NCT01770704.

The effect of the time to remission on residual symptoms and functioning among depressive patients

OBJECTIVES

To explore the effect of time to remission on residual symptoms, functioning and quality of life (QOL) of the patients with major depressive disorder (MDD).

METHOD

A total of 434 patients were enrolled from 16 sites of China. The Quick Inventory of Depressive Symptomatology-Self Report (QIDS-SR) and self-rating scales were assessed at baseline, and months 1, 3 and 6. Baseline remitters were defined as those subjects with a QIDS-SR score ≤ 5 at baseline. Later remitters was defined as those reaching remission one month (Month 1 remitters) or three month (Month 3 remitters) after baseline. Persistent non-remitters were defined as those with QIDS-SR score > 5 at all 3 assessments. A follow-up assessment was done at month 6 to examine outcomes. Cross-lagged models indicated QIDS-SR predicted social functioning and QOL.

RESULTS

Totally, 179 patients at baseline achieved remission. An additional 141 participants remitted at month 1 (n = 94) or month 3 (n = 47), and 63 patients were persistent non-remitters. There were significant differences between all groups on depression severity at baseline. QOL was similar for both late remitter groups, which was better than non-remitters, but lower than early-remitters. Late remitters and non-remitters showed significant differences on change of functioning and QOL (P < 0.001) at each visit. By 6 months, all remitting groups showed lower depression severity and better social functioning and QOL than persistent non-remitters. Cross-lagged models indicated QIDS-SR predicted social functioning and QOL.

CONCLUSION

We confirmed the association of earlier remission with a better quality of remission at early stage; but the time to remission does not affect future functioning and QOL.

[Predictive value of the product of plasma colchicine concentration and poisoning time for the prognosis of colchicine poisoning patients]

Objective: To investigate the predictive value of the product of first plasmacolchicine concentration and poisoning time for the prognosis of colchicine poisoning patients, and to provide a basis for early prognosis assessment. Methods: October 2021, patients with colchicine poisoning admitted in the First Affiliated Hospitol of Wenzhou Medical University from January 2017 to September 2021 were collected, including general information such as patient gender, age, oral colchicine dose, poisoning time, the first laboratory test index andplasma colchicine concentration after admission. The patients were divided into survival group and death group according to their prognosis. The differences in clinical indicators such as admission plasma colchicine concentration, blood routine, blood biochemistry, coagulation function, and blood gas analysis were compared between the two groups, and their predictive value for the prognosis of patients were analyzed. Results: A total of 23 patients with colchicine poisoning, aged 20-85 years, were included in this study, of which 15 cases (65.22%) survived and 8 cases (34.78%) died. The first plasma colchicine concentration at admision were 0.42-53.61 ng/ml. The plasma colchicine concentration and the concentration-time product were 10.08-2147.04 h·ng/ml.Compared with the survival group, the plasma colchicine concentration and the concentration-time product in the death group were significantly increased, and the differences were statistically significant (P<0.05). Univariate logistic regression analysis showed that first plasma concentration and poisoning time>132.48 h·ng/ml, high C-reactive protein, high D-dimer, high absolute value of BE were the risk factors for the prognosis of patients with colchicine poisoning (OR=12.000, 95%CI: 1.1181-128.836; OR=1.053, 95%CI: 1.009-1.098; OR=1.219, 95%CI: 1.039-1.429; OR=1.360, 95%CI: 1.1.044-1.773; P<0.05). High prothrombin time activity was protective factor affecting the prognosis of colchicine poisoning patients (OR=0.941, 95%CI: 0.892~0.993; P<0.05). ROC curve analysis showed that the areas under the curves of first plasma concentration and poisoning time, C-reactive protein, absolute value of BE, D-dimer for predicting the prognosis of patients with colchicine poisoning were 0.918, 0.888, 0.867, 0.837, respectively, and the areas under the curves of prothrombin time activityfor predicting the prognosis of patients with colchicine poisoning was 0.788 (P<0.05) . Conclusion: The product of the first plasma colchicine concentration at admission and poisoning time is closely related to the prognosis of patients with colchicine poisoning, it can be used as a predictor for early evaluation of the prognosis of poisoned patients.

[Association between a novel regulatory genetic variants and lung cancer risk in Chinese: a two-stage case-control study]

Objective: Regulatory quantitative trait loci (regQTL) theory can help to evaluate the regulation function of single nucleotide polymorphisms (SNPs) on crucial biological signals from a three-dimensional perspective. The aim of this study was to investigate the effect of these regQTL-SNPs on the susceptibility of lung cancer. Methods: Based on the regQTL theory, using the database of identified lung cancer regQTL-SNPs, we screened the SNPs that may function as regQTL in the reported susceptible regions of lung cancer by genome-wide association study(GWAS), and a two-stage case-control study was conducted (screening stage: 2 331 lung cancer cases and 3 077 healthy controls; validation stage: 626 lung cancer cases and 667 healthy controls) to definite the association of related regQTL-SNPs with the susceptibility of lung cancer. Results: A total of 8 regQTL-SNPs were screened in the reported susceptible regions of lung cancer by GWAS. Among which, 3 SNPs were significantly associated with the risk of lung cancer (P<0.05) in the screening stage. Further validation results indicated that the variant T allele of rs6998591 in ADRA1A was significantly associated with increased risk of lung cancer (additive model: OR=1.33, 95%CI:1.01-1.74, P=0.040). In addition, the variant G allele of rs11202916 in ACTA2 was significantly associated with decreased risk of lung cancer (recessive model: OR=0.71, 95%CI:0.52-0.96, P=0.026). Stratified analysis indicated that the variant T allele of rs6998591 significantly increased lung squamous cell carcinoma risk (additive model: OR=1.53, 95%CI: 1.01-2.32, P=0.043), while the variant G allele of rs11202916 significantly decreased lung adenocarcinoma risk (additive model: OR=0.83, 95%CI: 0.69-0.98, P=0.031). Gene-environment interaction analysis indicated that the risk of developing lung cancer increased by 235% in smoking individuals carrying rs6998591 variant T allele compared with those non-smoking individuals carrying no rs6998591 variant T allele(OR=3.35,95%CI:2.10-5.34,P<0.001). Conclusion: There are two regQTL-SNPs that could significantly affect the susceptibility of lung cancer in the GWAS reported susceptible regions of lung cancer.

[Association between sleep and prevalence of hypertension in elderly population]

Objective: To explore the association between sleep duration, sleep quality and the prevalence of hypertension in the elderly aged 65 years and above. Methods: This study was conducted among the elderly in communities in Yiwu, China from April to July, 2019, and participants were recruited through physical examination in the hospital. Face-to-face interview was performed to obtain basic information. Sleep duration and sleep quality were evaluated by Pittsburgh Sleep Quality Index (PSQI). Associations between sleep duration, sleep quality and hypertension were evaluated by multivariate logistic regression analysis. Results: A total of 3 169 elderly persons, aged ≥65 years old, were included in the study. The overall prevalence of hypertension was 50.8%. The elderly with very poor sleep quality and short sleep duration accounted for 22.4% and 28.5%, respectively. After adjusting for demographic characteristics, socioeconomic status, lifestyle and health status, the OR of hypertension for the elderly with very poor sleep quality was 1.42 (95%CI: 1.12-1.80) compared with those with very good sleep quality. Compared with the elderly with sleep duration of 6-7 h a night, the OR of hypertension for those with sleep duration <6 h was 1.37 (95%CI: 1.15-1.65). As the sleep quality decreased, the risk for hypertension increased. An U-shaped association was found between sleep duration and risk of hypertension. Subgroup analyses showed that this association existed in both men and women, but only significant in the elderly aged <75 years. Conclusion: Poor sleep quality and short sleep duration were associated with risk for hypertension in the elderly.

Optofluidic gradient refractive index resonators using liquid diffusion for tunable unidirectional emission

Resonators have been used in a wide range of fields, such as biochemical detection and microscale lasers. In recent years, optofluidic resonators have attracted a significant amount of attention owing to their unique liquid environments. Liquids containing biochemical samples can be designed to pass through the ring resonators or to directly form droplets, for sample sensing. Liquid diffusion is an important property in optofluidic applications, such as gradient refractive index lenses and waveguides. However, liquid diffusion has not been used in the study of optofluidic resonators, for both possible sensing characteristics, and unidirectional emission that is mostly acted as light sources. Here, we introduce a gradient refractive index profile formed by liquid diffusion in annular channels into a circular resonator, forming a gradient-index resonator with a tunable unidirectional emission. For both simulations and experiments, the squeezed and non-rotationally symmetrical light intensity profile was first obtained in a circular resonator. The squeezed light profile enables unidirectional emission in circular resonators, which is difficult to achieve in conventional ones. The squeezed light profile and unidirectional emission are determined by the refractive index difference of the liquids used, the dimension of the circular channels, and the working wavelengths. In experiments, different dimensions of bending radii were demonstrated and a tunable squeezed light intensity profile and unidirectional emission were exhibited. Interestingly, the squeezed coefficient of light, which was about 1.8 for a bending radius of 100 μm, enabled emission with a divergence angle as small as 14 degrees, which could be used for laser emission applications in the future. This work reveals the significant potential of the novel liquid gradient refractive index resonator, which provides a practicable approach for optofluidic resonator emission applications and also has potential for use in optofluidic sensing based on the squeezed light profile.

[Changes of serum lipoprotein-related phospholipase A2 in patients with white matter lesion based on KIM classification and its correlation with carotid atherosclerotic plaque]

Objective: To explore the relationships between serum lipoprotein-associated phospholipase A2 (Lp-PLA2) and KIM-based white matter lesion (WML) and carotid atherosclerotic plaque. Methods: From November 2018 to July 2019, 155 patients admitted to the Department of Neurology of the First Affiliated Hospital of Anhui Medical University were enrolled, with 125 cases of brain MRI manifestations of white matter lesions allocated to WML group and 30 cases of normal MRI in control group (NC group). According to KIM classification, WML patients were further divided into juxtaventricular white matter lesion (JVWML) group (n=30), periventricular white matter lesion (PVWML) group (n=33), juxtacortical white matter lesion (JCWML) group (n=30) and deep white matter lesion (DWML) group (n=32). Clinical Data of vascular risk factors in all subjects was collected and reviewed. Serum Lp-PLA2 content was determined by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). Carotid atherosclerosis plaques were detected by carotid artery ultrasonography and divided into stable and vulnerable plaques, and thus total score of each plaque was subsequently calculated according to the Crouse method. Results: The Lp-PLA2 ((117±37) ng/ml vs (95±30) ng/ml), stable Crouse plaque integral (CPI) (0 (0,2.5) vs 0) and unstable CPI (0 (0,3.4) vs 0) in the WML group were significantly higher than those in the NC group (all P<0.05). Lp-PLA2 ((138±41) ng/ml) and unstable CPI (1.5(0,3.8)) in the PVWML group were significantly higher than those in the NC group (all P<0.05). Lp-PLA2 levels in the PVWML group were significantly higher than those in the JVWML group ((100±28) ng/ml) and JCWML group ((101±27) ng/ml) (all P<0.05). Correlation analysis revealed that blood glucose (r=0.600, P=0.000), triglyceride (TG) (r=0.371, P=0.034), low-density lipoprotein cholesterol (LDL-C) (r=0.367, P=0.036) and Lp-PLA2 (r=0.567, P=0.001) were positively correlated with unstable CPI in PVWML group, while it is negatively correlated with HDL-C (r=-0.368, P=0.035). Multivariate linear regression of all relevant factors and unstable CPI in the PVWML group showed that blood glucose (b=0.463, P<0.01) and Lp-PLA2 (b=0.347, P<0.05) were still positively correlated with unstable CPI. Conclusions: Serum Lp-PLA2 is an indicator of atherosclerosis, which is associated with carotid instability plaques in periventricular WML, suggesting that inflammatory mechanism plays an important role in the development of ischemic white matter lesions.

Does early and late life depression differ in residual symptoms, functioning and quality of life among the first-episode major depressive patients

AIMS & OBJECTIVES

Age differences exist in many aspects in patients with major depressive disorder (MDD). The present study aims to examine the effect of age on treatment outcomes in first-episode MDD.

METHODOLOGY

A total of 982 first-episode major depressive patients, who were above 18 years old and admitted in both psychiatric hospitals and units of general hospitals were recruited for the present study. These patients were newly treated and responded to 8-12 weeks of antidepressant treatment. Depressive symptoms, psychosocial functioning and quality of life were measured using standardized instruments. The study population was divided into three age groups: early adult (18-44 years old), middle adult (45-59 years old), and late adult (60-85 years old).

RESULTS

Earlier age was associated with greater symptom severity, severer depressive symptoms in hypersomnia, concentration/decision making, negative view of the self, suicide ideation and restlessness, more impaired function, poorer satisfaction in social relationship and economic status, when compared to late adults with MDD (all P < 0.05). In the multivariable analyses, among the other variables, early age remained as an independent correlation of residual depressive severity (middle age vs. early age: OR = 0.631, 95%CI[0.462, 0.862]; old age vs. early age: OR = 0.521, 95%CI[0.348, 0.780]) and functional impairment. Comorbidity of physical illness had a negative contribution to all treatment outcomes.

CONCLUSION

In first major depressive episode, early age was strongly associated with depressive severity and functional impairment after responding to antidepressant treatment. Early-life depression may be an indicator of MDD for poor clinical outcomes and high clinical burden.

Microglia M1/M2 polarization contributes to electromagnetic pulse-induced brain injury

The development of electronic technology has attracted attention on the biological effects of electromagnetic fields (EMFs) and electromagnetic pulse (EMP). It remains controversial whether EMP irradiation is neurotoxic or beneficial for recovery from injuryies such as cerebral ischemia. Microglia is innate immune cells in the brain, exhibiting either neurotoxicity or neuroprotection effect during various central nervous system diseases, depending on their activation into a classical (M1) or alternative (M2) phenotype, respectively. The Toll-like receptor-4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor kappa B (NFκB) pathway is important for microglia activation. In this study, we investigated the effect of EMP on neuronal apoptosis and microglia polarization in vivo and in vitro, using an EMP of 400 kV/m and 1 hertz for 200 pulses. Short EMP irradiation (≤24 h) resulted in microglial conversion from the resting to the M1-type state, activation of the TLR4/MyD88/NFκB pathway, higher levels of inflammatory cytokines including interleukin (IL)-6, IL-1β and tumor necrosis factor-α, as well as neuronal apoptosis induction. In contrast, long EMP irradiation (3 days) resulted in microglial activation into the M2-type, decreased apoptosis and inflammatory mediator production, and increased levels of the neuroprotective effectors IL-10, transforming growth factor beta, and brain-derived neurotrophic factor. EMP induces both neuronal damage and neuronal recovery by influencing the switch of M1/M2 polarization and the TLR4/MyD88/NFκB pathway.

[Effects of left heart function changes on cerebral small vessel diseases and its cognitive impairment]

Objective: To explore the correlation of left heart function changes with cognitive impairment in patients with cerebral small vessel diseases (CSVD). Methods: From February 2012 to June 2018, 199 CSVD patients admitted to the Department of Neurology of the First Affiliated Hospital of Anhui Medical University were enrolled as CSVD group. A total of 103 healthy elderly persons without cognition disorders were included as normal control group (NC group). According to the diagnostic criteria, CSVD patients were divided into 112 CSVD patients with vascular cognitive impairment (CSVD-VCI group) and 87 CSVD patients without cognitive impairment (CSVD-NCI group). Neuroimaging markers of CSVD (including lacunar infarction and white matter hyperintensity) were assessed through brain MRI. Cognitive function was evaluated by The Mini-Mental State Examination (MMSE), the Cambridge Cognitive Examination-Chinese Version (CAMCOG-C), etc. Routine echocardiography was performed to evaluate left ventricular ejection fraction (LVEF), left atrial diameter (LAD) and other parameters. Results: Compared with NC group, the LVEF level was significantly decreased in CSVD group [(65±5)% and (63±6)%, respectively] (P=0.007), while LAD level was significantly increased in CSVD group (P=0.024). The LVEF level of CSVD-VCI group [(62±6)%] was significantly lower than that of CSVD-NCI group [(64±5)%] (P=0.02). Correlation analysis revealed MMSE and CAMCOG-C scores in CSVD group were positively correlated with LVEF level (r=0.210, P=0.003; r=0.238, P=0.001). Logistic regression analysis revealed that declined LVEF was an independent risk factor associated with CSVD (OR=0.937, 95%CI 0.890-0.986) and CSVD-VCI (OR=0.900, 95%CI 0.829-0.977). Conclusions: Left heart function changes play important roles in the occurrence of CSVD and severity of its cognitive impairment. The declined LVEF may represent an independent risk factor for CSVD and its cognitive impairment.

[Case-control study on the influencing factors related to cognitive impairment in the elderly population of China]

Objective: To explore the influencing factors affecting the cognitive impairment of the elderly population in China. Methods: A stratified multi-stage cluster sampling was used in 6 provinces (autonomous administrative regions and municipalities) to select the sample. A total 24 000 urban and rural residents aged 60 years and above received a set of standardized questionnaire interview, physical examinations, laboratory test of lipid and glucose levels of blood and apolipoprotein E (APOE) genotype. The primary screening of cognitive function was assessed by using the Chinese Version of Ascertain Dementia 8, and then suspicious cognitive impairment cases with more than two abnormal results would receive the further cognitive function assessment by using the Mini-Mental State Examination (MMSE). 1 300 cases with cognitive impairment and 2 600 controls without cognitive impairment were recruited and matched according to their age, gender and resident area in a 1∶2 case-control study. The conditional logistic regression model was used to analyze the association between relevant factors and cognitive impairment. Results: Factors negatively associated with cognitive impairment and their OR (95%CI) values were primary or middle school as 0.63 (0.51-0.77), high school and above as 0.59 (0.39-0.88), daily neighborhood communication as 0.61 (0.50-0.75), weekly participating in social activities 0.59 (0.44-0.79), daily tea drinking as 0.71 (0.58-0.88) and doing regular exercise as 0.71 (0.57-0.88), reading newspaper (occasional: 0.50 (0.37-0.67); frequent: 0.40 (0.28-0.57)), playing majiang or cards (occasional: 0.51 (0.34-0.74); frequent: 0.50 (0.36-0.68)) respectively. Factors positively associated with cognitive impairment and their OR (95%CI) values were APOE-ε4 heterozygote as 1.31 (1.08-1.58), homozygote as 2.74 (1.52-5.00), diabetes onset before 50 years of age and after as 9.03 (3.07-33.60) and 4.40 (3.18-6.17), stroke as 1.90 (1.35-2.69), asthma as 1.95 (1.11-3.42) respectively. Conclusion: APOE-ε4 alleles, lower educational level, stroke, asthma, diabetes are risk factors of cognitive impairment in the elderly. Keeping a healthy lifestyle and preventing chronic diseases in the whole life course could significantly reduce the incidence of cognitive impairment in the elderly.

Precise label-free leukocyte subpopulation separation using hybrid acoustic-optical chip

Leukocyte subpopulations contain crucial physiological information; hence, precise and specific leukocyte separation is very important for leukemia diagnosis and analysis. However, conventional centrifugation and immunofluorescence-based separation methods are inaccurate and inconvenient due to the overlapping cell size and density or complex marking processes. Herein, we report a new label-free technology for precise leukocyte subpopulation separation by synergy of acoustic and optical technologies. Standing surface acoustic wave (SSAW) solved the problem of gentle and precise focusing of cells in optical systems. In addition, SSAW was used for the separation of granulocytes, which have evident size distinction from other components. In case of lymphocytes and monocytes, which have overlap in size/density, optical force could distinguish them accurately based on the RI difference, with the convenience of acoustic pre-focusing. In this experiment, separation of three types of leukocyte subtypes with considerable throughput and purity was conducted, through which we obtained 99% pure lymphocytes, 98% pure monocytes, and 95% pure granulocytes. Experimental results prove that the device has robust ability in separating leukocyte phenotypes and have the advantages of being non-invasive, label-free and precise. In the future, this convenient hybrid method will be a potential powerful tool for auxiliary clinical diagnosis and analysis.

[Thyroglobulin measurement in fine-needle aspiration washout fluid for detection of differentiated thyroid cancer lymph nodes metastases]

Objective: To investigate the feasibiity of detecting lymph node metastasis in differentiated thyroid cancer patients by thyroglobin（Tg）measurement in fine-needle aspiration washout fluid. Method: Forty-seven differentiated thyroid cancer patients with cervical lymph node metastasis were included in this study. Fine-needle aspirations were performed on lymph nodes which were surgically resected for measurement of Tg in washout fluid. Diagnostic sensitivity, specificity and accuracy were evaluated according to three predetermined Tg threshold values: FNA-Tg/serum Tg＞1, 10 ng/ml and 100 ng/ml. Result: The meadian value of FNA-Tg in metastatic lymph node (n=46) was 5 177 ng/ml (1.79-408 300 ng/ml)，while lymph node without metastasis (n=11) showed a meadian level of 0.63 ng/ml (0.04-125.4 ng/ml). With the threshold of FNA-Tg level at FNA-Tg/serum Tg＞1, 10 ng/ml and 100 ng/ml respectively, the diagnostic sensitivity was 91.3%, 97.83% and 93.48% respectively,the specificity was 81.82%,63.64% and 90.90% respectively,and the accuracy was 89.47%,91.22% and 92.98% respectively. Conclusion: Thyroglobin measurement in fine-needle aspiration washout fluid is effective to diagnose lymph node metastasis in differentiated thyroid cancer.

Optofluidic differential colorimetry for rapid nitrite determination

Nitrite detection plays a very important role in environmental monitoring and for industrial purposes. The commonly used colorimetric analysis requires the measurement of a system's calibration curve by asynchronously preparing and detecting a dozen standard samples, leading to time-consuming, slow and cumbersome procedures. Here, we present a differential colorimetry method that determines the nitrite level based on the paired chromaticity gradient, formed by coupling the colour reaction into the microfluidic network. The two gradients reshape each other and contain enough information for the quantitative analysis of the sample being tested, without the need for a calibration curve. The independence of the two gradients of the absorbance change caused by the detecting system and water quality results in a high stability and anti-interference performance, with the assistance of its self-correcting ability. This differential colorimetry method requires little time and energy consumption as only one sample is needed. Standard nitrite solutions of 0.50 mM and 0.33 mM have been determined with an error of 1.16% and 0.50%, respectively. These measurements are advantageous in terms of greater stability by up to 10 times and accuracy by 6 times, compared with the calibration curve approaches. It is foreseeable that this differential colorimetry method will find a wide range of applications in the field of chemical detection.

Real-time detection and monitoring of the drug resistance of single myeloid leukemia cells by diffused total internal reflection

Real-time detection and monitoring of the drug resistance of single cells have important significance in clinical diagnosis and therapy. Traditional methods operate a number of times for each individual concentration, and innovation is required for the design of more simple and efficient manipulation platforms with necessary higher sensitivity. Here, we have developed a novel diffused total internal reflection (TIR) method to perform drug metabolism and cytotoxicity analysis of trapped myeloid leukemia cells. Molm-13 cells, a type of acute myeloid leukemia cell, were chosen and injected into the device and fittingly captured by cell traps. Differing from previous studies, a series of different concentrations of azelaic acid (AZA) drug could be used from 0 mM to 50 mM through convection and diffusion processes in a single chip, with each concentration region featuring 50 cells, with a total of 549 cell trapping units. Thanks to the high sensitivity of the TIR method, only cells with the same drug concentration could be illuminated in the detection process. By adjusting the incident angle, we could exactly detect and monitor the drug resistance of the cells using different drug concentrations and the experimental resolution of the drug concentration was as small as 5 mM. Images of the membrane integrity and morphology of the cells in the bright field were measured and we also monitored the cell viabilities in the dark field over 2 hours. The effects of AZA on the Molm-13 cells were explored in different concentrations at the single cell level. Compared with the results of the traditional MTT assay method, the experimental results are more simple and accurate. A cell death of 5% at an AZA concentration of 5 mM was observed after 30 minutes, while a concentration of 40 mM corresponded to a 98% cell death. The designed method in this study provides a novel toolkit to control and monitor drug resistance at the single cell level more easily with higher sensitivity and we believe it has significant potential application in single cell quality assessment and medicine analysis in clinical practice.

Optofluidic marine phosphate detection with enhanced absorption using a Fabry-Pérot resonator

Real-time detection of phosphate has significant meaning in marine environmental monitoring and forecasting the occurrence of harmful algal blooms. Conventional monitoring instruments are dependent on artificial sampling and laboratory analysis. They have various shortcomings for real-time applications because of the large equipment size and high production cost, with low target selectivity and the requirement of time-consuming procedures to obtain the detection results. We propose an optofluidic miniaturized analysis chip combined with micro-resonators to achieve real-time phosphate detection. The quantitative water-soluble components are controlled by the flow rate of the phosphate solution, chromogenic agent A (ascorbic acid solution) and chromogenic agent B (12% ammonium molybdate solution, 80% concentrated sulfuric acid and 8% antimony potassium tartrate solution with a volume ratio of 80 : 18 : 2). Subsequently, an on-chip Fabry-Pérot microcavity is formed with a pair of aligned coated fiber facets. With the help of optical feedback, the absorption of phosphate can be enhanced, which can avoid the disadvantages of the macroscale absorption cells in traditional instruments. It can also overcome the difficulties of traditional instruments in terms of size, parallel processing of numerous samples and real-time monitoring, etc. The absorption cell length is shortened to 300 μm with a detection limit of 0.1 μmol L^-1. The time required for detection is shortened from 20 min to 6 seconds. Predictably, microsensors based on optofluidic technology will have potential in the field of marine environmental monitoring.

The significance of Akt/NF-κb signaling pathway in the posterior cataract animal model

OBJECTIVE

To establish SD rat posterior capsular opacification (posterior capsular opacification- PCO) animal model, and to detect the expression of Akt/NF-kb signaling pathway in the PCO model.

METHODS

30 healthy SD rats were randomly divided into control group (0d) and the experimental groups (7d and 14 d), there were 10 rats at all time points. All rats (right eye) were treated with the lens capsule, and the inflammatory reaction of the anterior segment of the eye and the occurrence of PCO at different time points were observed under the microscope. The TGF-β concentration of humor aquosus was measured at the different time points by ELISA method. Eyeballs were removed after the rats were killed. RT-PCR method was used to detect the gene expression levels of Akt and NF-κb and Westen Blot method to detect the protein expression of Akt, p-Akt, NF-κb and p-NF-κb.

RESULTS

TGF-β concentration, Akt and NF-κb gene expression, and Akt, p-Akt, NF-κb and p-NF-κb protein expression in humor aquosus, increased with the time and the time-dependence was significant.

CONCLUSION

Akt/NF-κb signaling pathway may be closely related to the occurrence and development of PCO, which may be related to the role of protein phosphorylation (Fig. 5, Ref. 20).

A switchable 3D liquid-liquid biconvex lens with enhanced resolution using Dean flow

Liquid-liquid (L²) microlenses have great potential for various applications in imaging and detection systems. Traditional L² microlenses are almost two-dimensional (2D) due to the modulation of flow rates in planer chips. Fundamental difficulties in effective application to cell imaging and analysis arise due to the limitations of 2D profiles. Herein, we demonstrate the feasible design of three-dimensional (3D) L² biconvex lenses to detect flowing cells. Using the auxiliary curved microchannels, a 3D L² lens is formed using Dean flow. The shape of the 3D biconvex lens and its focal length can be modulated by tuning the flow rates of the liquids. 3D light focusing was successfully achieved and the focal length could be modulated by around 435 μm, from 3554 μm to 3989 μm, in the experiment. The numerical aperture of the 3D L² lens was also measured and its range was 0.175-0.198. Compared to a traditional objective lens with the same magnification (4×/0.1), the resolution of the 3D L² biconvex lenses was improved 1.79-fold due to being completely immersed in liquid. Mouse myeloma cells sp2/0 and acute promyelocytic leukemia cells NB4 were imaged in the contrast experiments. The time response of experimental manipulation was about 2.7 ms. This 3D biconvex lens has great application prospects for cell imaging and analysis systems in lab-on-a-chip settings.

Elevated PT, APPT and PT/INR possibly associated with doxycycline and cefoperazone co-administration: A case report

WHAT IS KNOWN AND OBJECTIVE

Little is known regarding changes in blood coagulation parameters associated with tetracycline antibiotics. We report a possible case of elevated PT, APPT and PT/INR associated with doxycycline and cefoperazone co-administration.

CASE SUMMARY

An 83-year-old Chinese male inpatient with severe pneumonia, chronic renal insufficiency and malnutrition experienced elevated PT, APPT and PT/INR which occurred within a few days of doxycycline added to his cefoperazone treatment and returned to normal after removal of it.

WHAT IS NEW AND CONCLUSION

Very close monitoring of coagulation parameters might be advisable in those subjects when administering doxycycline and cefoperazone concomitantly.

Label-free identification of the microstructure of rat spinal cords based on nonlinear optical microscopy

The spinal cord is a vital link between the brain and the body and mainly comprises neurons, glial cells and nerve fibres. In this work, nonlinear optical (NLO) microscopy based on intrinsic tissue properties was employed to label-freely analyze the cells and matrix in spinal cords at a molecular level. The high-resolution and high-contrast NLO images of unstained spinal cords demonstrate that NLO microscopy has the ability to show the microstructure of white and grey matter including ventral horn, intermediate area, dorsal horns, ventral column, lateral column and dorsal column. Neurons with various sizes were identified in grey matter by dark spots of nonfluorescent nuclei encircled by cytoplasm-emitting two-photon excited fluorescence signals. Nerve fibres and neuroglias were observed in white matter. Besides, the spinal arteries were clearly presented by NLO microscopy. Using spectral and morphological information, this technique was proved to be an effective tool for label-freely imaging spinal cord tissues, based on endogenous signals in biological tissue. With future development, we foresee promising applications of the NLO technique for in vivo, real-time assessment of spinal cord diseases or injures.

Switchable 3D optofluidic Y-branch waveguides tuned by Dean flows

Optical branch waveguides are one of the most important optical elements and have been widely exploited for optical communication systems. However, prevailing devices are typically solid and have limit in tunability. Liquid optical devices have attracted more interest for the advantage of tunability of liquid media, but their signals suffer serious leakage if the refractive index (RI) of liquid is smaller than that of solid channels. This paper demonstrates the tunable three-dimensional (3D) optofluidic Y-branch waveguides in plannar microchannels by simply introducing Dean flow. This device can reconfigure 3D Y-branch profiles and separate the intensity of light as tunable ratio from 0 to 1 by adjusting the flow rates with low loss. Different from the prevailing 2D liquid counterparts, the 3D configuration offer much more freedom in the selection of liquid media as liquid's RI can be totally independent to the solid channel structure. The transmission loss through the device is estimated to 0.97 db when the splitting angle is 10°, which shows the light is confined better in the 3D liquid structures than traditional 2D liquid counterparts. The Y-branch waveguides show potential in applications of integrated optofluidic devices.

Tunable focusing properties using optofluidic Fresnel zone plates

A Fresnel zone plate (FZP) is a unique diffractive optical device and widely used in integrated optical systems such as interferometers and antennas. A traditional FZP utilizes solid materials and cannot be modulated in real time for desired focusing properties. This paper reports a tunable optofluidic FZP based on a solid-liquid hybrid structure. This FZP consists of two parts including a fast microfluidic mixer, which can adjust the refractive index of liquids from 1.332 to 1.432, and subsequently an optical FZP with a solid-liquid combination. Simulations and experiments successfully showed the real-time tunability of the focusing properties such as peak intensity, focal spot sizes and focal lengths. The focal spot size can be modulated from 16 μm to 80 μm at λ₀ = 532 nm in experiments with focal length changes of approximately 700 μm. Moreover, it can be easily switched between focusing, defocusing and collimation. The dispersion with different wavelengths was also investigated, showing that these types of focusing properties are quite different from a traditional optofluidic lens by refraction or reflection. It is foreseeable that such a hybrid FZP may find wider applications in lab-on-a-chip systems and optical devices.

Aquaporin 4 inhibition decreased synthesis of cytokines by acetazolamide in the hippocampus of rats with pentrazol-induced chronic epilepsy

Epilepsy refers to a clinical syndrome generated by spontaneous seizures in the central nervous system. Epilepsy triggers a complex pathological process including inflammatory response and aquaporin 4 (AQP4) increase. It has been reported that AQP4 helps to enhance the immunological function of the central nervous system in pathological conditions, but the relationship between AQP4 and inflammatory cytokines is poorly understood in chronic epilepsy processes. As an inhibitor of sulfonamide carbonic anhydrase (CA), acetazolamide (AZA) may inhibit water infiltration through AQP4. In this context, pentylenetetrazole (PTZ) is used to induce the chronic epilepsy model in rats to study the chronic epilepsy effects of AQP4 inhibition on proinflammatory cytokine expression in the hippocampus and proinflammatory cytokine quantification analysis of the plasma. Based on the assumption that AQP4 regulates proinflammatory cytokine expression, this article aims to demonstrate this effect in chronic epilepsy of rats. Rats were divided into four groups and were treated with different drugs: saline (Control), acetazolamide (AZA), pentylenetetrazole (PTZ), and pentylenetetrazole plus acetazolamide (PTZ+AZA). The data showed that seizures increased proinflammatory cytokine expression and that AZA significantly inhibited AQP4 expression. Overall, the results suggested that AQP4 inhibition could weaken excitotoxicity in epileptogenesis by reducing proinflammatory cytokines in the hippocampus. The findings provide a new insight into the involvement of cerebral edema insult and proinflammatory cytokines in the process of chronic epilepsy.

Optofluidic restricted imaging, spectroscopy and counting of nanoparticles by evanescent wave using immiscible liquids

Conventional flow cytometry (FC) suffers from the diffraction limit for the detection of nanoparticles smaller than 100 nm, whereas traditional total internal reflection (TIR) microscopy can only detect few samples near the solid-liquid interface mostly in static states. Here we demonstrate a novel on-chip optofluidic technique using evanescent wave sensing for single nanoparticle real time detection by combining hydrodynamic focusing and TIR using immiscible flows. The immiscibility of the high-index sheath flow and the low-index core flow naturally generate a smooth, flat and step-index interface that is ideal for the TIR effect, whose evanescent field can penetrate the full width of the core flow. Hydrodynamic focusing can focus on all the nanoparticles in the extreme centre of the core flow with a width smaller than 1 μm. This technique enables us to illuminate every single sample in the running core flow by the evanescent field, leaving none unaffected. Moreover, it works well for samples much smaller than the diffraction limit. We have successfully demonstrated the scattering imaging and counting of 50 nm and 100 nm Au nanoparticles and also the fluorescence imaging and counting of 200 nm beads. The effective counting speeds are estimated as 1500, 2300 and 2000 particles per second for the three types of nanoparticles, respectively. The optical scattering spectra were also measured to determine the size of individual Au nanoparticles. This provides a new technique to detect nanoparticles and we foresee its application in the detection of molecules for biomedical analyses.

Nucleotide variation in the Toxoplasma gondii micronemal protein 8 gene

Toxoplasma gondii is a successful opportunistic protozoan distributed worldwide, which can infect all vertebrates, leading to serious infection, blindness, and abortion. Micronemal (MIC) proteins are critically important for T. gondii infection, as they participate in various stages of the Toxoplasma life cycle, including invasion and attachment to host cells. MIC8 secretion relies on the concentration of intracellular calcium, and can mediate the invasion of T. gondii by interacting with soluble MIC3. To investigate genetic diversity of the MIC8 gene, 16 T. gondii strains from different hosts and geographical locations, and two reference isolates (ToxoDB: TGME49_245490 and TGVEG_245490) were examined in this study. The results showed that all the examined MIC8 genes are 2055 bp, with an A+T content ranging from 50.2 to 50.6%. Conversely, lower levels of variation were detected within their nucleotide and amino acid sequences. Phylogenetic analyses indicated that three classical genotypes of T. gondii and the ToxoDB#9 genotype did not group exclusively via Bayesian inference, maximum parsimony, neighbor joining, and/or maximum likelihood assays based on the nucleotide and amino acid sequences of the MIC8 gene. In summary, the T. gondii MIC8 gene is not a suitable marker for population genetic studies of this parasite.

Tunable self-imaging effect using hybrid optofluidic waveguides

Multimode interference (MMI) is a typical self-imaging phenomenon and has been widely exploited for optical devices like couplers and splitters. Usually, it utilizes solid waveguides only and thus has very limited tunability in self-imaging properties. This paper reports our original work on tunable MMI using a hybrid optofluidic waveguide. It is generated by the diffusion between miscible flows in a microchannel and consists of two parts: gradient-index liquid-liquid waveguide for light modulation and step-index liquid-solid waveguide for image formation. Simulation and experiments have shown successful realization of the real-time tuning of self-imaging properties. For detail, the image point (focal spot) width could be modulated from 7 μm to 16 μm, and the self-imaging period changes in the range of 500 μm by varying the fluid properties. It is foreseeable that such a hybrid optofluidic waveguide may find wider applications in lab-on-a-chip systems and optical devices.

Phylogenetic, Morphological, and Pathogenic Characterization of Alternaria Species Associated with Fruit Rot of Blueberry in California

Fruit rot caused by Alternaria spp. is one of the most important factors affecting the postharvest quality and shelf life of blueberry fruit. The aims of this study were to characterize Alternaria isolates using morphological and molecular approaches and test their pathogenicity to blueberry fruit. Alternaria spp. isolates were collected from decayed blueberry fruit in the Central Valley of California during 2012 and 2013. In total, 283 isolates were obtained and five species of Alternaria, including Alternaria alternata, A. tenuissima, A. arborescens, A. infectoria, and A. rosae, were identified based on DNA sequences of the plasma membrane ATPase, Alt a1 and Calmodulin gene regions in combination with morphological characters of the culture and sporulation. Of the 283 isolates, 61.5% were identified as A. alternata, 32.9% were A. arborescens, 5.0% were A. tenuissima, and only one isolate of A. infectoria and one isolate of A. rosae were found. These fungi were able to grow at temperatures from 0 to 35°C, and mycelial growth was arrested at 40°C. Optimal radial growth occurred between 20 to 30°C. Pathogenicity tests showed that all five Alternaria spp. were pathogenic on blueberry fruit at 0, 4, and 20°C, with A. alternata, A. arborescens, and A. tenuissima being the most virulent species, followed by A. infectoria and A. rosae. Previously A. tenuissima has been reported to be the primary cause of Alternaria fruit rot of blueberry worldwide. Our results indicated that the species composition of Alternaria responsible for Alternaria fruit rot in blueberry can be dependent on geographical region. A. alternata, A. arborescens, A. infectoria, and A. rosae are reported for the first time on blueberry in California. This is also the first report of A. infectoria and A. rosae infecting blueberry fruit.

Sequence variation in ROP8 gene among Toxoplasma gondii isolates from different hosts and geographical localities

The protozoan parasite Toxoplasma gondii has a worldwide distribution; it can cause serious diseases in humans and almost all other warm-blooded animals. Different genotypes of T. gondii result in different lesions in the same host. T. gondii rhoptry protein 8 (TgROP8) is a major factor of T. gondii acute virulence. We examined sequence variation in the TgROP8 gene among T. gondii isolates from different hosts and geographical localities. The TgROP8 gene was amplified from individual isolates and sequenced. A phylogenetic tree was constructed using Bayesian inference, maximum parsimony, and maximum likelihood based on the sequences obtained plus TgME49 from the ToxoDB database. The TgROP8 gene was 1728 bp in length for all the examined T. gondii strains, and their A+T contents were 45.37-45.95%. Sequence analysis detected 140 (0.06-5.56%) variable nucleotide positions resulting in 96 (0-10.78%) amino acid substitutions. Sequence variations in the TgROP8 gene resulted in polymorphic restriction sites for endonucleases BstBI, BsaI, and XhoI, which allowed the differentiation of the three classical genotype strains (types I, II, and III) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). However, phylogenetic analyses indicated that the TgROP8 gene is not a suitable genetic marker for population studies of T. gondii.

Differentiating the extent of cartilage repair in rabbit ears using nonlinear optical microscopy

Nonlinear optical microscopy (NLOM) was used as a noninvasive and label-free tool to detect and quantify the extent of the cartilage recovery. Two cartilage injury models were established in the outer ears of rabbits that created a different extent of cartilage recovery based on the presence or absence of the perichondrium. High-resolution NLOM images were used to measure cartilage repair, specifically through spectral analysis and image texture. In contrast to a wound lacking a perichondrium, wounds with intact perichondria demonstrated significantly larger TPEF signals from cells and matrix, coarser texture indicating the more deposition of type I collagen. Spectral analysis of cells and matrix can reveal the matrix properties and cell growth. In addition, texture analysis of NLOM images showed significant differences in the distribution of cells and matrix of repaired tissues with or without perichondrium. Specifically, the decay length of autocorrelation coefficient based on TPEF images is 11.2 ± 1.1 in Wound 2 (with perichondrium) and 7.5 ± 2.0 in Wound 1 (without perichondrium), indicating coarser image texture and faster growth of cells in repaired tissues with perichondrium (p < 0.05). Moreover, the decay length of autocorrelation coefficient based on collagen SHG images also showed significant difference between Wound 2 and 1 (16.2 ± 1.2 vs. 12.2 ± 2.1, p < 0.05), indicating coarser image texture and faster deposition of collagen in repaired tissues with perichondrium (Wound 2). These findings suggest that NLOM is an ideal tool for studying cartilage repair, with potential applications in clinical medicine. NLOM can capture macromolecular details and distinguish between different extents of cartilage repair without the need for labelling agents.

Sequence variation and bioinformatics analysis of Toxoplasma gondii GRA16 Gene

Toxoplasmosis is caused by the intracellular protozoan Toxoplasma gondii. It is anopportunistic zoonosis in warm-blooded animals and humans, with a worldwide distribution. Toxoplasma gondii dense granule protein 16 (TgGRA16) can modulate some functions in host cells and is considered a significant virulent factor of the parasite. The present study reports sequence variation in TgGRA16 gene among T. gondii strains from different hosts and geographical locations, and the construction of phylogenetic relationships of these T. gondii strains based on sequences of TgGRA16, and analysis of B cell epitopes in TgGRA16. Our results showed that all TgGRA16 gene sequences were 1518 bp and the C+G contents ranged from 52.17% to 52.59%. Sequence variation in the TgGRA16 gene was 0-1.51%. Phylogenetic analysis revealed that TgGRA16 gene sequence could not be used to differentiate the different T. gondii genotypes. Six B cell epitopes were predicted in TgGRA16. These results indicated that TgGRA16 gene is not an ideal marker for studying genetic relationships of T. gondii isolates, but may represent a good vaccine candidate against toxoplasmosis.

Viscosupplementation of synovial fluid with xanthan gum for treatment of osteoarthritis and its clearance kinetics in the rabbit knee joint

BACKGROUND

Injection of xanthan gum (XG) has been demonstrated to reduce the symptoms and progression of osteoarthritis (OA) in experimental models. Due to its high viscosity and stability, it may restore the rheological homeostasis of osteoarthritic synovial fluid (SF), and avoid numerous intra-articular injections.

OBJECTIVE

The present study investigated the effect of XG on the rheological properties of SF, and determined its residence time in the rabbit joint cavity.

METHODS

Rabbit knees were subject to intra-articular injection with XG or XG labeled with green fluorescence, and the SF was collected at different time. Rheological properties of SF with XG injected were compared with those with sodium hyaluronate injected. Resistance to oxidant damage was tested by adding H2O2 to the viscosupplement. Fluorescence intensity was measured for the SF with XG labeled with green fluorescence.

RESULTS

Results showed that XG could significantly improve the SF viscosity at 24, 96, 168 h, and increase the storage moduli (G') and loss moduli (G″) tested at frequency of 0.5 and 2.5 Hz. SF with XG injection exhibited a gel-like behavior at 24 h, in that G' exceed G″ over the entire oscillation frequency range. XG preparation had a high resistance to oxidant damage. Half-life of XG in the joint cavity was 35.9 h, with clearance obeying first-order kinetics.

CONCLUSIONS

Intra-articular injection of XG could improve the rheological properties of SF, and this effect could last for several days.

Low-level sequence variation in Toxoplasma gondii calcium-dependent protein kinases among different genotypes

The causative agent of toxoplasmosis, Toxoplasma gondii, can infect virtually all nucleated cell types of warm-blooded animals. In this study, we examined the sequence variation in calcium-dependent protein kinase 2 (CDPK2) genes among 13 T. gondii strains from different hosts and geographical locations. The results showed that the lengths of the complete CDPK2 DNA and cDNA sequences were 3671-3673 and 2136 bp, respectively, and the sequence variation was 0-0.9% among different T. gondii strains. Phylogenetic analysis based on the CDPK2 gene sequences revealed that T. gondii strains of the same genotypes were clustered in different clades. Further analysis of all the other T. gondii CDPK genes in genotype I (GT1), II (ME49), or III (VEG) strains indicated the T. gondii CDPK gene family is quite conserved, with sequence variation ranging from 0 to 1.40%. We concluded that CDPK2 as well as all the other CDPK genes in T. gondii cannot be used as proper markers for studying the variants of different T. gondii genotypes from different hosts and geographical locations, but their sequence conservation may be a useful feature promoting them as anti-T. gondii vaccine candidates in further studies.

Identification and bioinformatic analysis of a putative calcium-dependent protein kinase (CDPK6) from Toxoplasma gondii

Toxoplasma gondii is recognized as an opportunistic human pathogen with a worldwide distribution. Development of effective vaccines is considered the only ideal way to control T. gondii infection. However, only one live vaccine is commercially available for use in sheep and goats. Therefore, the identification of more effective antigenic proteins is very important. In this study, we identified a novel putative calcium-dependent protein kinase of T. gondii, TgCDPK6, and further analyzed its potential antigenicity using a bioinformatic approach. The physical and chemical characteristics, transmembrane domain, epitopes, advanced structure, and functional sites of TgCDPK6 were predicted by multiple bioinformatic approaches. Twenty-six post-translational modification sites were identified in the protein. The secondary structure showed that 58.35% amino acids of TgCDPK6 are exposed to the solvent interface, and the high hydrophilic domains were distributed in amino acid positions 21-59, 68-81, 156-205, 245-271, 280-294, 297-324, 334-356, 367-393, 474-498, and 543-553. The advanced structure of TgCDPK6 was developed by a homology modeling method and was validated by PROCHECK, which showed that most amino acid residues were in the most favored regions. Using these analyses, 10 potential epitopes were predicted. The results indicated that TgCDPK6 could be a vaccine candidate antigen against T. gondii.

Characterization of the Toxoplasma gondii hsp60 gene sequences from different hosts and geographical locations

The intracellular protozoan Toxoplasma gondii is one of the most successful parasites, with the ability to invade all warm-blooded animals, including humans. T. gondii heat shock protein 60 (TgHSP60) plays an important role in intracellular survival and in the differentiation of the parasite, and is also recognized as being associated with its virulence. In the present study, we examined sequence variation in the hsp60 coding region among five T. gondii isolates from different hosts and geographical regions, which were compared with the corresponding sequences of strains ME49, 76K, and GT1 available in the ToxoDB databases. The length of the T. gondii hsp60 sequence was 1728 bp for all strains, and the A+T content ranged from 41.96 to 42.13%. The sequence alignment of the 8 T. gondii strains identified 20 variable positions (0-1.44%) and showed 1.16% overall sequence variation, suggesting a relatively considerable sequence diversity. Phylogenetic analysis of hsp60 sequences using Bayesian inference and maximum parsimony differentiated the two major clonal lineage types into their respective clusters, and thus separated atypical strains from classical genotypes. The results of the present study suggested that the coding region of the hsp60 gene may represent a novel genetic marker for intraspecies phylogenetic analyses of T. gondii.

Changes in cardiac aldosterone and its synthase in rats with chronic heart failure: an intervention study of long-term treatment with recombinant human brain natriuretic peptide

The physiological mechanisms involved in isoproterenol (ISO)-induced chronic heart failure (CHF) are not fully understood. In this study, we investigated local changes in cardiac aldosterone and its synthase in rats with ISO-induced CHF, and evaluated the effects of treatment with recombinant human brain natriuretic peptide (rhBNP). Sprague-Dawley rats were divided into 4 different groups. Fifty rats received subcutaneous ISO injections to induce CHF and the control group (n=10) received equal volumes of saline. After establishing the rat model, 9 CHF rats received no further treatment, rats in the low-dose group (n=8) received 22.5 μg/kg rhBNP and those in the high-dose group (n=8) received 45 μg/kg rhBNP daily for 1 month. Cardiac function was assessed by echocardiographic and hemodynamic analysis. Collagen volume fraction (CVF) was determined. Plasma and myocardial aldosterone concentrations were determined using radioimmunoassay. Myocardial aldosterone synthase (CYP11B2) was detected by quantitative real-time PCR. Cardiac function was significantly lower in the CHF group than in the control group (P<0.01), whereas CVF, plasma and myocardial aldosterone, and CYP11B2 transcription were significantly higher than in the control group (P<0.05). Low and high doses of rhBNP significantly improved hemodynamics (P<0.01) and cardiac function (P<0.05) and reduced CVF, plasma and myocardial aldosterone, and CYP11B2 transcription (P<0.05). There were no significant differences between the rhBNP dose groups (P>0.05). Elevated cardiac aldosterone and upregulation of aldosterone synthase expression were detected in rats with ISO-induced CHF. Administration of rhBNP improved hemodynamics and ventricular remodeling and reduced myocardial fibrosis, possibly by downregulating CYP11B2 transcription and reducing myocardial aldosterone synthesis.

Prevalence of Clonorchis sinensis infection in freshwater fishes in northeastern China

The prevalence of Clonorchis sinensis infection in freshwater fishes was surveyed in Heilongjiang Province, northeastern China, between August 2011 and September 2013. Thirteen species of freshwater fish (n=3221) and one species of shrimp (n=93) were collected from Songhua river, Nenjiang river and other lakes or ponds in 37 sites of 15 representative cities in Heilongjiang Province. They were individually examined by digestion technique, and the C. sinensis metacercariae were identified morphologically followed by confirmation using sequences of the second internal transcribed spacer of ribosomal DNA. Ten of the 13 examined species of freshwater fishes were infected with C. sinensis metacercariae, while all shrimps were negative. The overall prevalence of C. sinensis infection in 3221 examined freshwater fishes was 19.96%, with 42.57% (272/639) in Pseudorasbora parva, 22.55% (83/368) in Hemicculter leuciclus, 20.44% (121/592) in Carassius auratus, 17.71% (68/384) in Saurogobio dabryi, 10.85% (23/212) in Rhodeus ocellatus, 10.54% (48/455) in Phoxinus lagowskii, 8.20% (21/256) in Perccottus glehnii, 6.25% (5/80) in Misgurnus anguillicaudatus, 4.55% (1/22) in Xenocypris davidi, and 1.49% (1/67) in Cyprinus carpio. The average infection intensity in P. parva was 103.3 encysted metacercariae per gram of fish meat in Zhaoyuan city. The average prevalence of C. sinensis infection in Songhua river, Nenjiang river and lakes or ponds were 31.96% (503/1574), 11.30% (102/903) and 7.93% (59/744), respectively. The prevalence of C. sinensis infection in Zhaoyuan city (43.68%) was the highest among all sampling locations. These results revealed a high-prevalence of C. sinensis infection in freshwater fishes in Heilongjiang Province, northeastern China, posing significant public health concern.

Sequence variation in the Toxoplasma gondii eIF4A gene among strains from different hosts and geographical locations

Toxoplasma gondii is an opportunistic protozoan parasite that infects a wide range of animals, including humans. The T. gondii eukaryotic translation initiation factor 4A (eIF4A) protein is expressed in the tachyzoite, but its expression is markedly downregulated in the bradyzoite, and it is therefore considered to be associated with tachyzoite virulence. The present study examined sequence variation in the eIF4A gene among nine strains of different genotypes from different hosts and geographical localities using polymerase chain reaction amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference. The complete genomic sequence of the eIF4A gene was 3156 bp in length in the strain TgCgCaI, 3153 bp in the strain MAS, 3152 bp in the strain TgPNY, and 3154 bp in the other six strains. Sequence analysis identified 29 (0-0.8%) variable nucleotide positions among all strains, with 16 of these variations located in the coding region, while the other 12 were distributed between the two introns. Phylogenetic analyses revealed that these eIF4A sequences were not effective molecular markers for intra-species phylogenetic analysis and differential identification of T. gondii strains from different hosts and geographical locations. This study demonstrated the existence of low sequence variation in the eIF4A gene, suggesting that T. gondii eIF4A may represent a suitable candidate vaccine against toxoplasmosis.

Prevalence and genetic characterization of Toxoplasma gondii infection in bats in southern China

Toxoplasma gondii can infect a wide variety of warm-blooded animals, including bats. Limited information on T. gondii infection in bats is available in China. The objective of the present study was to determine prevalence and genetic diversity of T. gondii infection in bats in southern China. A total of 608 bats representing 12 species, including 120 Aselliscus stoliczkanus, 59 Myotis chinensis, 11 Miniopterus schreibersii, 53 Rhinolophus affinis, 32 Rhinolophus pusillus, 81 Hipposideros armiger, 28 Hipposideros fulvus, 32 Cynopterus brachyotis, 14 Cynopterus sphinx, 45 Eonycteris spelaea, 109 Hipposideros larvatus, and 24 Taphozous melanopogon, were collected from Yunnan and Guangxi provinces, southern China. They were examined for the presence of T. gondii DNA by amplification of the B1 gene using a nested PCR, and the positive samples were genotyped at 11 genetic loci (SAG1, 5'- and 3'-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Fifty-nine (9.7%) of these bats were detected positive by PCR but only five of these positive DNA samples were completely typed at all loci; of which 4 samples, 2 from A. stoliczkanus, and 2 from H. larvatus, belonged to ToxoDB Genotype #10, and the other one from H. larvatus was identified as ToxoDB Genotype #9 (http://toxodb.org/toxo/). To our knowledge, this is the first report of molecular detection and genetic characterization of T. gondii infection in bats in China. The results show that these bats are potential reservoirs for T. gondii transmission, which may pose a threat to human health.

Chlamydia psittaci exposure in pet birds

Chlamydia psittaci is a zoonotic pathogen with a wide range of avian hosts and may be transmitted to humans and cause severe disease. To assess the risk of psittacosis posed by pet birds, the seroprevalence of Chlamydia psittaci antibodies in 360 Eurasian siskins (Carduelis spinus), 289 oriental skylarks (Alauda arvensis) and 36 black-tailed grosbeaks (Coccothraustes migratorius) in Gansu province, north-western China was detected by an indirect haemagglutination assay. Twenty-seven out of 289 (9.34 %) Alauda arvensis, 45 out of 360 (12.50 %) Carduelis spinus and 2 out of 36 (5.56 %) Coccothraustes migratorius were positive for Chlamydia psittaci infection at a cut-off dilution of 1 : 16. The prevalence of Chlamydia psittaci was higher in Carduelis spinus (12.5 %) than in Alauda arvensis (9.34 %) and Coccothraustes migratorius (5.56 %); however, the differences were not statistically significant (P>0.05). Statistical analysis indicated that Chlamydia psittaci seroprevalence in adult pet birds (12.4 %, 67/540) was significantly higher than that in juvenile pet birds (4.83 %, 7/145) (P<0.01). There was no statistical difference in Chlamydia psittaci seroprevalence between male (12.4 %) and female (8.27 %) birds. To our knowledge, this is the first report indicating the seroprevalence of Chlamydia psittaci exposure in pet birds in China. Our results indicate that close contact with pet birds poses the risk of zoonotic transmission of Chlamydia psittaci.

Toxoplasma gondii rhoptry protein 38 gene: sequence variation among isolates from different hosts and geographical locations

Toxoplasma gondii is an obligate intracellular parasite that is able to infect almost all mammalian species, and may lead to toxoplasmosis of the host. In the present study, we examined sequence variation in rhoptry protein 38 (ROP38) genes among T. gondii isolates collected from different hosts and geographical regions. The complete ROP38 gene from 13 T. gondii isolates was amplified and sequenced. The results of sequence alignments showed that the lengths of the entire ROP38 gene ranged from 2646 to 2650 bp, with a sequence variation of 0.2-1.1%, among the 13 T. gondii isolates. This result indicated low sequence variation in the ROP38 gene. Phylogenetic analysis of ROP38 sequences using Bayesian inference showed that the clustering of the 13 T. gondii isolates was not consistent with their respective genotypes. This result indicates that the ROP38 gene is not a suitable genetic marker for population genetic studies of different T. gondii genotypes from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, and hence worthy of further research.

MH II-DAB gene expression in grass carp Ctenopharyngodon idella (Valenciennes) after infection with the ciliate parasite, Ichthyophthirius multifiliis

The grass carp, Ctenopharyngodon idella (Valenciennes), is one of the most extensively aquacultured freshwater fish in China. However, because of the lack of effective control measures and the high-density culture environment, considerable economic losses are caused by infection of C. idella with the parasitic ciliate, Ichthyophthirius multifiliis. The major histocompatibility (MH) DAB gene belongs to antigen-presented genes in the class II genomic region, which is associated with parasite resistance. To understand the relationship of the DAB gene with I. multifiliis infection in grass carp, the expression profiles of MH II-DAB were studied in tissues using real-time quantitative polymerase chain reaction. The results showed that expression of the MH II-DAB gene was up-regulated in head kidney after I. multifiliis infection, and the expression peak appeared earlier in the study (case) group than in the control group. The obvious up-regulation peak of MH II-DAB gene was found at days 2 and 4 in skin; at 12 h to day 4 in spleen; at 12 h and days 1 and 6 in gill; and at day 10 in blood, whereas the MH II-DAB gene was down-regulated in liver and intestines after I. multifiliis infection. These results have implications for better understanding C. idella resistance to I. multifiliis infection.

Seroprevalence of Chlamydia psittaci infection in market-sold adult chickens, ducks and pigeons in north-western China

Chlamydia psittaci, the agent of psittacosis in humans, infects a wide range of avian species. To assess the risk of psittacosis posed by domestic birds in the urban environment, the prevalence of C. psittaci antibodies in 413 chickens (Gallus domesticus; 305 caged and 108 free-range), 334 ducks (Anas spp.; 111 caged and 223 free-range) and 312 pigeons (Columba livia) in Lanzhou, north-western China, was detected using the indirect haemagglutination assay. The specific antibodies were found in sera of 55 (13.32 %) chickens, 130 (38.92 %) ducks and 97 (31.09 %) pigeons. Statistical analysis showed that the seroprevalence of C. psittaci infection in chickens was significantly lower than that in ducks and pigeons (P<0.05). The C. psittaci seroprevalence in caged and free-range chickens was 7.54 % and 29.63 %, respectively, and the difference was statistically significant (P<0.05). The C. psittaci seroprevalence in caged and free-range ducks was 26.13 % and 45.29 %, respectively (P<0.05). To our knowledge, this is the first study indicating the presence of C. psittaci infection in market-sold chickens, ducks and pigeons in north-western China. Close contact with these birds is associated with a risk of zoonotic transmission of C. psittaci. Public education should be implemented to reduce the risk of avian to human transmission of such a pathogenic agent.

A comparative study at two different altitudes with two dietary nutrition levels on rumen fermentation and energy metabolism in Chinese Holstein cows

The object of this study was to investigate the effect of two altitudes (1600 vs. 3600 m) with two nutritional levels [5.88 MJ/kg dry matter (DM) vs. 7.56 MJ/kg DM] on apparent total tract digestibility, rumen fermentation, energy metabolism, milk yield and milk composition in Chinese Holstein cows. Sixteen Chinese Holstein cows in their third lactation with close body weights, days in milk and milk yield were randomly divided into four groups, of which two were directly transferred from Lanzhou (altitude of 1600 m) to Lhasa (altitude of 3600 m). Four treatments (high plateau and high nutrition level, HA-HN; high plateau and low nutrition level, HA-LN; low plateau and high nutrition level, LA-HN; and low plateau and low nutrition level, LA-LN) were randomly arranged in a 2 × 2 factorial experimental design. Results indicated that the apparent total tract digestibility of a diet's DM, organic matter, crude protein, neutral detergent fibre and acid detergent fibre and DM intake were not affected by either altitude or nutrition level (p > 0.05). Milk protein percentage was higher for the diet with the high level of nutrition than for the diet with low nutrition level irrespective of altitude (p < 0.05). Percentages of milk fat and milk lactose were not affected by either altitude or nutrition level (p > 0.05). The metabolizable energy used for milk energy output was decreased by high altitude in comparison with that at low altitude (p < 0.05). No differences were observed in the live body weight or body condition score (BCS) of Chinese Holstein cows among all of the four treatments (p > 0.05).

Modulation of mouse macrophage proteome induced by Toxoplasma gondii tachyzoites in vivo

Toxoplasma gondii is an obligate intracellular protozoan parasite, which can invade and multiply within the macrophages of humans and most warm-blooded animals. Macrophages are important effector cells for the control and killing of intracellular T. gondii, and they may also serve as long-term host cells for the replication and survival of the parasite. In the present study, we explored the proteomic profile of macrophages of the specific pathogen-free Kunming mice at 24 h after infection with tachyzoites of the virulent T. gondii RH strain using two-dimensional gel electrophoresis combined with matrix-assisted laser desorption ionization time-of-flight (TOF)/TOF tandem mass spectrometry. Totally, 60 differentially expressed protein spots were identified. Among them, 52 spots corresponded to 38 proteins matching to proteins of the mouse, including actin, enolase, calumenin, vimentin, plastin 2, annexin A1, cathepsin S, arginase-1, arachidonate 12-lipoxygenase, and aminoacylase-1. Functional prediction using Gene Ontology database showed that these proteins were mainly involved in metabolism, structure, protein fate, and immune responses. The findings provided an insight into the interactive relationship between T. gondii and the host macrophages, and will shed new lights on the understanding of molecular mechanisms of T. gondii pathogenesis.