Biotemplated fabrication of N/O co-doped porous carbon confined spinel NiFe2O4 heterostructured mimetics for triple-mode sensing of antioxidants and ameliorating packaging properties

In this work, shrimp shell-derived magnetic NiFe2O4/N, O co-doped porous carbon nanozyme with superior oxidase (OXD)-like activity was prepared and used for colorimetric/photothermal/smartphone dual-signal triple-mode detection of antioxidants in fruits and beverages. The magnetic NiFe2O4/N, O co-doped porous carbon (MNPC) material was triumphantly fabricated using a combined in-situ surface chelation and pyrolysis method. The resultant MNPC composite exhibits a superior OXD-like activity, which can effectively oxidize 3,3',5,5'-tetramethylbenzidine (TMB) for yielding colorimetric/temperature dual-signal (CTDS) in absence of H2O2. This CTDS output sensor was successfully used for the determination of ascorbic acid and tannic acid. The proposed CTDS sensor with good specificity and high sensitivity can satisfy different on-site analysis requirements. Interestingly, the MNPC as a sustainable filler was further used for improving packaging properties of polyvinyl alcohol film. In short, this work offers a large-scale and cheap method to fabricate magnetic carbon-based nanozyme for monitoring antioxidants and ameliorating packaging properties.

[Molecular mechanisms of quinolone resistance in non-typhoidal Salmonella]

By conducting retrospective analysis, this study aim to investigate the resistance mechanism of quinolones in non-typhoidal Salmonella (NTS). A total of 105 strains of NTS isolated from clinical specimens from the Fifth Affiliated Hospital of Southern Medical University from May 2020 to February 2021 were used as research objects. VITEK2 Compact automatic identification drug sensitivity analysis system and serological test were used to identify the strains. The sensitivity of the strains to ciprofloxacin, levofloxacin and nalidixic acid was detected by AGAR dilution method. The whole genome of 105 strains of NTS was sequenced. Abricate and other softwares were used to analyze drug-resistant genes, including plasmid-mediated quinolone resistance gene (PMQR) and Quinolone resistance determination region (QRDR). Serotypes and ST types were analyzed using SISTR and MLST, and phylogenetic trees were constructed. The results showed that the NTS isolated in this region were mainly ST34 Salmonella typhimurium (53.3%). The drug sensitivity results showed that the drug resistance rates of NTS to ciprofloxacin, levofloxacin and nalidixic acid were 30.4%, 1.9% and 22.0%, respectively, and the intermediate rates of ciprofloxacin and levofloxacin were 27.6% and 54.2%.A total of 46 (74.2%) of the 62 quinolone non-susceptible strains carried the PMQR gene, mainly qnrS1 (80.4%), followed by aac(6')-Ib-cr(15.2%); there were 14 NTS and 8 NTS had gyrA and parC gene mutations, respectively. The gyrA was mutations at the amino acid position 87, Asp87Tyr, Asp87Asn, Asp87Gly, and Thr57Ser mutations were detected in parC. In conclusion, this study found that NTS had relatively high resistance to quinolones, carrying qnrS1 gene mainly resulted in decreased sensitivity of NTS to ciprofloxacin and levofloxacin, and gyrA:87 mutation mainly resulted in NTS resistance to Nalidixic acid; Salmonella typhimurium in clinical isolates showed clonal transmission and required further epidemiological surveillance.

Combined exposure to manganese and iron decreases oxidative stress-induced nerve damage by increasing Nrf2/HO-1/NQO1 expression

BACKGROUND

Manganese (Mn) and iron (Fe) are essential trace elements for humans, yet excessive exposure to Mn or Fe can accumulate in the central nervous system (CNS) and cause neurotoxicity. The purpose of this study was to investigate the effects of Mn and Fe exposure, alone or in combination, on inducing oxidative stress-induced neurological damage in rat cortical and SH-SY5Y cells, and to determine whether combined exposure to these metals increases their individual toxicity.

METHODS

SH-SY5Y cells and male Sprague-Dawley rats were used to observe the effects of oxidative stress-induced neurological damage induced by exposure to manganese and iron alone or in combination. To detect the expression of anti-oxidative stress-related proteins, Nrf2, HO-1, and NQO1, and the apoptosis-related proteins, Bcl2 and Bax, and the neurological damage-related protein, α-syn. To detect reactive oxygen species generation and apoptosis. To detect the expression of the rat cortical protein Nrf2. To detect the production of proinflammatory cytokines.

RESULTS

We demonstrate that juvenile developmental exposure to Mn and Fe and their combination impairs cognitive performance in rats by inducing oxidative stress causing neurodegeneration in the cortex. Mn, Fe, and their combined exposure increased the expression of ROS, Bcl2, Bax, and α-syn, activated the inflammatory factors IL-6 and IL-12, inhibited the activities of SOD and GSH, and induced oxidative stress-induced neurodegeneration both in rats and SH-SY5Y cells. Combined Mn-Fe exposure attenuated the oxidative stress induced by Mn and Fe exposure alone by increasing the expression of antioxidant factors Nrf2, HO-1, and NQO1.

CONCLUSION

In both in vivo and in vitro studies, manganese and iron alone or in combination induced oxidative stress, leading to neuronal damage. In contrast, combined exposure to manganese and iron mitigated the oxidative stress induced by exposure to manganese and iron alone by increasing the expression of antioxidant factors. Therefore, studies to elucidate the main causes of toxicity and establish the molecular mechanisms of toxicity should help to develop more effective therapeutic modalities in the future.

Signal Transduction Associated with Mn-induced Neurological Dysfunction

Manganese (Mn) is a heavy metal that occurs widely in nature and has a vital physiological role in growth and development. However, excessive exposure to Mn can cause neurological damage, especially cognitive dysfunction, such as learning disability and memory loss. Numerous studies on the mechanisms of Mn-induced nervous system damage found that this metal targets a variety of metabolic pathways, for example, endoplasmic reticulum stress, apoptosis, neuroinflammation, cellular signaling pathway changes, and neurotransmitter metabolism interference. This article reviews the latest research progress on multiple signaling pathways related to Mn-induced neurological dysfunction.

Diagnostic value of the vascular index measured by superb microvascular imaging for evaluating breast tumors: a meta-analysis

AIM

This meta-analysis aims to assess the accuracy of superb microvascular imaging (SMI) using the vascular index (VI) in the diagnosis of breast tumors.

MATERIAL AND METHODS

PubMed, Web of Science, Embase, Cochrane Library and Scopus were searched for relevant literature by two researchers until March 14, 2023. The Stata Version 16.0 software was utilized to compute the pooled values for sensitivity (Sen), specificity (Spe), positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odd ratios (DOR). Heterogeneity among the included literature was assessed using the I2 statistic and Q test. Conducting influence analysis was used to ensure the robustness of the pooled conclusions and the Deeks' funnel plot asymmetry test to assess publication bias. We also performed the summary receiver operating characteristic (SROC) curve.

RESULTS

Six studies included 1200 breast lesions. The ultimate results in the VI of SMI are as follows: The pooled Sen was 0.80 (95% confidence interval(CI), 0.75-0.85), the pooled Spe was 0.68 (95% CI 0.63-0.74), the pooled PLR was 2.54 (95% CI 2.07-3.12), the pooled NLR was 0.29 (95% CI 0.22-0.38), the pooled DOR was 8.91 (95% CI 5.62-14.13), and the area under the SROC (AUC) was 0.81.

CONCLUSION

The application of SMI using VI may have the potential to benefit the patients and represents a valuable quantitative parameter of SMI for the diagnosis of breast neoplasms.

Protective Effects of Sodium Para-Aminosalicylic Acid on Lead and Cadmium Co-Exposure in SH-SY5Y Cells

Background: Combined exposure to lead and cadmium is common in occupational environments. However, the effects of co-exposure to Pb-Cd on neurotoxicity have not been fully clarified. Sodium para-aminosalicylic acid (PAS-Na) has previously been shown to protect neurons from Pb-induced toxicity. This study aimed to investigate the beneficial effect of PAS-Na against co-exposure to Pb-Cd-induced neurodegeneration in SH-SY5Y cells. Methods: The MTT assay was used to detect the effects of Pb and Cd alone, or in combination, on SH-SY5Y cell survival. The effects of Pb and Cd alone or in combination on oxidative stress were assessed by reactive oxygen species (ROS) level. Nrf2, the master switch for antioxidant responses, was detected by immunofluorescence. Protein expression levels of PI3K, Akt, p-Akt, Nrf2 and HO-1 were determined by Western blot analysis. Results: MTT assay results established that the survival rate of SH-SY5Y cells was not significantly affected by exposure to 1 μmol/L lead, 0.25 μmol/L cadmium, and 1-fold Pb-Cd mixture (1 μmol/L Pb + 0.25 μmol/L Cd), while 10-fold Pb-Cd combined exposure (10 μmol/L Pb + 2.5 μmol/L Cd) significantly reduced the survival rate of SH-SY5Y cells. Combined Pb-Cd exposure significantly increased intracellular ROS levels, and N-Acetyl-L-cysteine (NAC) treatment in the 10 μmol/L Pb + 2.5 μmol/L Cd group significantly decreased ROS expression levels, attenuating the levels of oxidative stress. Protein expression of PI3K and p-Akt significantly decreased in the 10 μmol/L Pb + 2.5 μmol/L Cd group, while the expression of PI3K and p-Akt protein increased after PAS-Na intervention. Immunofluorescence analysis showed that levels of Nrf2 in the nucleus increased in the 10 μmol/L Pb + 2.5 μmol/L Cd group, along with Nrf2 protein levels, suggesting that Nrf2 was translocated from the cytoplasm into the nucleus upon combined Pb-Cd exposure. In addition, HO-1 protein expression level, a downstream gene product of Nrf2, was increased. In response to NAC intervention, HO-1 protein expression levels significantly decreased. PAS-Na had the same intervention effect as NAC. Conclusion: Combined exposure to Pb-Cd induced oxidative stress and cytotoxicity in SH-SY5Y cells. PAS-Na displayed antagonistic effects on neurodegenerative changes induced by combined Pb-Cd exposure; hence, it may afford a novel treatment modality for exposure to these metals.

Sodium para-aminosalicylic acid ameliorates brain neuroinflammation and behavioral deficits in juvenile lead-exposed rats by modulating MAPK signaling pathway and alpha-synuclein

Lead (Pb) is a developmental neurotoxin that can disrupt brain development and damage the brain regions responsible for executive function, behavioral regulation and fine motor control. Sodium para-aminosalicylic acid (PAS-Na) is a non-steroidal anti-inflammatory drug that can cross the blood-brain barrier. The purpose of this study was to examine the effects of juvenile rat Pb exposure on behavioral changes and brain inflammation, and the efficacy of PAS-Na in ameliorating these effects. The results showed that Pb exposure during the juvenile period (from weaning to adult period) delayed rats' growth development and impaired their motor learning. Pb exposure not only increased Pb concentrations in several brain regions (including hippocampus, striatum and substantia nigra), but also disrupted metal-homeostasis in the brain, as higher levels of iron (Fe) and calcium (Ca) were observed in the substantia nigra. Moreover, Pb activated the MAPK pathway and increased levels of inflammatory factors such as IL-1β, TNF-α and IL-6 in the hippocampus, striatum and substantia nigra. Furthermore, Pb increased the levels of alpha-synuclein (α-syn) in these brain sites. PAS-Na improved the motor deficits and brain inflammation in the Pb-exposed rats. Moreover, the elevated Pb, Fe and Ca concentrations in the brain were significantly reduced by PAS-Na, which contains amino, carboxyl and hydroxyl functional groups, suggesting that it may act as a chelator of brain metals. In addition, PAS-Na inhibited the Pb-induced MAPK pathway activation and α-syn accumulation in the same brain regions. Taken together, our novel study suggest that PAS-Na shows efficacy in improving the Pb-induced behavioral changes in rats by inhibiting MAPK-dependent inflammatory pathways and reducing α-syn accumulation.

Sodium Para-Aminosalicylic Acid Modulates Autophagy to Lessen Lead-Induced Neurodegeneration in Rat Cortex

Lead (Pb) is a common heavy metal contaminant in the environment, and it may perturb autophagy and cause neurodegeneration. Although sodium para-aminosalicylic (PAS-Na) has been shown to protect the brain from lead-induced toxicity, the mechanisms associated with its efficacy have yet to be fully understood. In this study, we evaluated the efficacy of PAS-Na in attenuating the neurotoxic effects of lead, as well as the specific mechanisms that mediate such protection. Lead exposure resulted in weight loss and injury to the liver and kidney, and PAS-Na had a protective effect against this damage. Both short-term and subchronic lead exposure impaired learning ability, and this effect was reversed by PAS-Na intervention. Lead exposure also perturbed autophagic processes through the modulation of autophagy-related factors. Short-term lead exposure downregulated LC3 and beclin1 and upregulated the expression of p62; subchronic lead exposure upregulated the expression of LC3, beclin1, and P62. It follows that PAS-Na had an antagonistic effect on the activation of the above autophagy-related factors. Overall, our novel findings suggest that PAS-Na can protect the rat cortex from lead-induced toxicity by regulating autophagic processes. (1) Short-term lead exposure inhibits autophagy, whereas subchronic lead exposure promotes autophagy. (2) PAS-NA ameliorated the abnormal process of lead-induced autophagy, which had a protective effect on the cerebral cortex.

Knowledge, attitudes, and practices towards COVID-19 among residents of Quang Binh, Vietnam

Introduction: The COVID-19 pandemic is raging worldwide; the number of new cases and deaths is increasing daily. This study aims to examine the knowledge, attitudes, and practices (KAP) toward COVID-19 among residents of Quang Binh, Vietnam. Methodology: A cross-sectional study was conducted between the 1st and 10th of March 2022 in Quang Binh with 413 participants through convenience sampling. A self-designed questionnaire was used for data collection, using SPSS (IBM Corp, Armonk, NY) version 26.0 for management and analysis. Results: Among the 413 participants, 80.5% of participants had good knowledge about COVID-19. Kinh people and those with a high level of education have higher odds of having good knowledge. 78.2% of participants had a positive attitude and 78.2% had good practice toward COVID-19. Knowledge-Practice scores and Attitude-Practice scores have a positive correlation. TV (65.4%) and the internet (66.6%) are the most popular channels for information about COVID-19. Common barriers for participants taking COVID-19 prevention measures were "due to the demands of life" (61%) or "due to the specificity of the work" (47.7%). Conclusions: Residents of Quang Binh have a moderate KAP towards COVID-19. Health education programs are needed to improve knowledge about COVID-19 among Quang Binh residents, with a focus on ethnic minorities and people with low levels of education.

[Effect Factors and Model Prediction of Soil Heavy Metal Bioaccessibility]

The soil environmental pollution situation has been severe in recent years, but studies on evaluating with bioavailability testing and prediction models are lacking, which makes it difficult to accurately assess the ecological risks of contaminated soil. As an important indicator of bioavailability, the bioaccessibility of cadmium (Cd), arsenic (As), copper (Cu), zinc (Zn), and lead (Pb) in the soil was analyzed in this study. The bioaccessibility content and their corresponding soil property data were screened and systematically analyzed to explore the relationship between bioaccessibility content and soil properties. Furthermore, some testing methods for bioaccessibility were summarized to analyze the relationship between bioaccessibility content, test methods, and bioavailability content. Additionally, the bioaccessibility content prediction models were established. The results showed that there was a strong correlation between the bioaccessibility content and the total content of heavy metals (P<0.01) and a significant (P<0.05) correlation with the soil pH. Different test methods had obvious effects on bioavailability. The proportion of bioaccessibility content determined via various test methods was as follows:in vitro gastrointestinal tract simulation>chemical reagent extraction. The proportions of bioaccessibility content of Cd and Pb in natural soil were relatively high, with mean values of 42.12% and 37.33%, respectively, indicating that Cd and Pb had higher risks of being absorbed by soil organisms. Moreover, 30 bioaccessibility prediction models for five heavy metals were constructed, which involved the soil properties and test methods. The results of this study can provide scientific information and bioaccessibility prediction models that can help in accurately assessing the ecological risks of contaminated soil.

Nesfatin-1 in lipid metabolism and lipid-related diseases

Nesfatin-1, an anorexic neuropeptide discovered in 2006, is widely distributed in the central nervous system and peripheral tissues. It has been shown to be involved in the regulation of food intake and lipid metabolism, inhibiting fat accumulation, accelerating lipid decomposition, and in general, inhibiting the development of lipid-related diseases, such as obesity and metabolic syndrome. Potential mechanisms of Nesfatin-1 action in lipid metabolism and lipid-related diseases will be discussed as well as its role as a biomarker in cardiovascular disease. This review expected to provide a new strategy for the diagnosis and prevention of clinically related diseases.

[Depression symtoms and related factors of fire fighters]

Objective: To analysis the status of the mental health and related factors of fire fighters in Tianjin Binhai New District, and to provide suggestions for their psychological health protection. Methods: 399 fire fighters in Tianjin Binhai New District were selected as study subjects in Jan to April 2019. Depression symptoms were measured by the depression module of the Patient Health Questionnaire (PHQ-9) . The Chinese version of Efrort Reword Imbalance (ERI) Questionnnaire were used to investigate and evaluate their occupational stress. Chi-Square test was used to analysis Categorical data. Binary logistic regression model was used to analysis the ralated factors of depression. Results: Among the 399 fire fighters, 71.1% (280/394) were found high level of depression symptom. The detection rates of depression symptoms in the related influceing factors ERI、station、disease、life pressure、eating habits and sleep disorder occupational stress were difierent (P<0.05) . Sleep disorder, life pressure and ERI occupational stress were risk factors for depressive symptoms (OR=1.921, 95% CI=1.002-3.682; OR=2.852, 95% CI=1.561-5.212; OR=2.367, 95% CI=1.163-4.818, P<0.05) . Conclusion: The rate of depression of fire fighters is relatively higher. Government should pay attention to and take measures to improve the psychological condition of fire fighters.

[CD44 regulates biological behavior and Ras signaling pathway in nasopharyngeal carcinoma stem cells]

Objective: To study the biological behavior of nasopharyngeal carcinoma stem cells and to explore the activation of Ras signaling pathway regulated by CD44. Methods: CNE2-SC and 5-8F-SC were nasopharyngeal carcinoma stem cells and obtained by serum-free suspension culture. Cell counting kit-8 (CCK-8) assay, colony formation assay, Transwell migration assay, cell adhesion array were used to investigate the growth, proliferation, migration and adhesion of nasopharyngeal carcinoma stem cells. Western blot test was used to detect the expressions of Ras signaling pathway related proteins and siRNA-mediated interference was used to determine the activation of Ras signaling pathway regulated by CD44. Results: The growth rates of CNE2-SC and 5-8F-SC cells were significantly lower than those of nasopharyngeal carcinoma cells at 24, 48 and 72 hours after inoculation (P<0.05). After 14 days of implantation, the colony formation rates of CNE2-SC (44.5±1.9)% and 5-8F-SC (47.4±1.8)% were higher than those of CNE2 (34.9±1.5)% and 5-8F (37.2±1.7)%, respectively(P<0.01). The migration cell number of CNE2-SC was (87.6±7.8), 3.97 times higher than that of CNE2 (P<0.01). The migration cell number of 5-8F-SC was (67.2±5.7), 3.07 times higher than 5-8F (P<0.01). The adhesion rates of CNE2-SC and CNE2 cells were (42.1±7.6)% and (8.9±2.0)%, respectively at 3 hours after inoculation and were (82.4±5.0)% and (12.1±2.2)% at 6 hours after inoculation, respectively. The adhesion rate of CNE2-SC cells was higher than that of CNE2 cells (all P<0.01). The adhesion rates of 5-8F-SC and 5-8F cells were (53.6±6.1)% and (7.3±1.5)% at 3 hours after inoculation, and (90.7±3.6)% and (11.0±1.2)% at 6 hours after inoculation, respectively. The adhesion rate of 5-8F-SC cells was higher than that of 5-8F cells (P<0.01). The expression levels of CD44, Ras and N-cadherin were significantly higher, while phosphatase and tensin homolog deleted on chromosome 10 (PTEN), E-cadherin in nasopharyngeal carcinoma stem cells were lower than those of the nasopharyngeal carcinoma cells. Furthermore, the levels of phosphorylated mitogen extracellular kinase1/2 (p-MEK1/2) and phosphorylated extracellular signal-regulated protein kinase1/2 (p-ERK1/2)were significantly increased in nasopharyngeal carcinoma stem cells (P<0.01). Correlation analysis showed that the protein expression levels of CD44 was highly positively correlated with RAS in nasopharyngeal carcinoma stem cells(r=0.985, P=0.002; r=0.962, P=0.038). Deletion of CD44 in CNE2-SC decreased the expression levels of HER-2, Ras and p-ERK1/2, p-Akt and phosphorylated protein kinase C-δ(p-PKCδ) (P<0.01). Conclusions: Despite compare to the nasopharyngeal carcinoma cell, nasopharyngeal carcinoma stem cells grows at a relatively slow rate, the capacities of clone formation, migration, adhesion are promoted. This may be related to the CD44-regulated abnormal activation of Ras signaling pathway.

[Hemodynamic response in cirrhotic patients with transjugular intrahepatic portosystemic shunt]

Objective: To discuss the effects of transjugular intrahepatic portosystemic shunt (TIPS) procedure on hemodynamics in cirrhotic patients. Methods: A total of 23 cirrhotic patients for TIPS insertion were enrolled from January 2018 to October 2018. Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), transthoracic echocardiography and non-invasive cardiac output measurement based on impedance cardiogram were carried out before and 24h, 1 month, 6 months after TIPS in order to observe cardiac function and hemodynamic changes after TIPS. Results: Significant increases in right atrial area [(17.2±4.0) cm(2) vs. (15.0±3.4) cm(2), P<0.05], right ventricular area [(15.1±3.8) cm(2) vs. (13.7±3.5) cm(2), P<0.05] and left ventricular volume [(97.4±21.5) ml vs. (91.1±22.7) ml, P<0.05] were observed 24 h after TIPS. These changes were accompanied with significant reduction in collapsible index of inferior vena cava [(20.7± 8.1)% vs. (28.6±11.3)%, P<0.01] and elevation in pulmonary arterial systolic pressure [(36.0±8.4) mmHg (1 mmHg=0.133 kPa) vs. (31.8±5.4) mmHg, P<0.01]. There also existed significantly elevated serum NT-proBNP [(551.2±325.1) ng/L vs. (124.2±94.4) ng/L, P<0.01], cardiac output [(5.82±0.96) L/min vs. (5.12±1.28) L/min, P<0.01], cardiac index [(3.47±0.64) L·min(-1)·m(-2) vs. (3.05±0.78) L·min(-1)·m(-2), P<0.01], early diastolic filling rate [(59.0±14.3)% vs. (54.5±11.0)%, P<0.05], and reduced systemic vascular resistance index (SVRi) [(1 798.4±357.3) dyne·s·cm(-5)·m(-2) vs. (2 195.7±508.7) dyne·s·cm(-5)·m(-2), P<0.01] 24 h after TIPS. At the end of 6-month follow-up, all these parameters, but not SVRi, returned towards baseline values. Moreover, peak early to late diastolic tissue velocity ratio at the level of lateral mitral annulus (E'/A') was significantly higher at the end of 6-month follow-up than that at baseline (1.06±0.32 vs. 0.90±0.45, P<0.05). Neither the right ventricular fractional area changes nor the left ventricular ejection fractions during the follow-up period were different from those at baseline (P>0.05). Conclusion: Cirrhotic patients who had no cardiovascular pathologies had adequate adaptation and good compensation ability to reach a new hemodynamic homeostasis for the increased volume load after TIPS insertion.

Artesunate inhibits atherosclerosis by upregulating vascular smooth muscle cells-derived LPL expression via the KLF2/NRF2/TCF7L2 pathway

Lipoprotein lipase (LPL) plays a central role in hydrolyzing triglyceride and its deficiency leads to atherosclerosis. Artesunate (ART), a derivative of artemisinin, has been demonstrated that ART reduces the formation of atherosclerotic plaques. However, it remains unclear whether ART-alleviated atherosclerotic lesion is involved in regulating lipid metabolism. ApoE^-/- mice were fed a high-fat diet to form atherosclerotic plaques and then injected with artesunate or not. Oil Red O, HE and Masson staining were performed to assess atherosclerotic plaques. Both Western blot and qRT-PCR were applied to detect protein expression. The Luciferase reporter gene and Chromatin immunoprecipitation assays were used to assess the interaction between proteins. Immunofluorescence assay was performed to show the localization of target proteins. In vitro, our data shown that ART increased LPL expression and inhibition of NRF2 blocked the binding of TCF7L2 to LPL promoter region in VSMCs. Downregulated Klf2 could decrease the nuclear enrichment of NRF2, TCF7L2 and LPL expression. In vivo, ART decreased atherosclerotic plaque formation and increased VSMC counts and LPL expression within atherosclerotic plaques. We observed the reduced tendency of serum lipids, and increased in serum LPL activity in mice. In support of vitro data, the markedly increased KLF2, TCF7L2 and LPL expression have been detected in aorta. Our study suggests that ART may be a novel therapeutic drug for inhibition of atherosclerotic plaque formation. The molecular mechanism may involve in upregulation of LPL expression via the KLF2/NRF2/TCF7L2 pathway in VSMCs.

[Distribution characteristics and correlation analysis of antibody detection value in myasthenia gravis]

Objective: To determine the factors affecting distribution and magnitude of antibody detection value in myasthenia gravis (MG). Methods: A total of 406 MG patients diagnosed at Department of Neurology, Peking University First Hospital from May 2015 to November 2017 were included.All of them exhibited muscle fatigue with decreased response in repetitive nerve stimulation test. There were 200 males and 206 females whose ages ranged from 2 to 85 years old. According to clinical classification of MG recommended by Myasthenia Gravis Foundation of America (MGFA), patients assigned to class I to class V included 200,140, 46, 15 and 5 cases, respectively. There were 33 cases of thymic hyperplasia and 63 cases of thymoma confirmed by radiological or pathological findings. Quantile plots and quantile regression model were used to determine the effects of age, gender and MGFA classification, thymus disease on acetylcholine receptors (AChR)antibody, acetylcholinesterase (AChE) antibody, Titin antibody, ryanodine receptor (RyR) antibody and muscle-specific tyrosine kinase (MuSK) antibody detection values detected by enzyme-linked immunosorbent assay (ELISA). Results: MGFA classification had effects on distribution of AChR antibody level. There was a positive correlation between age and AChR antibody level(P<0.05). Negative correlation was found between age and AChE, Titin and RyR antibody level (P<0.05). No significant correlation was shown between any factors and MuSK antibody level(P≥0.05). MGFA classification had a positive correlation with AChR antibody level (P<0.05) and no correlation with other antibody levels (P>0.05). Gender and thymus disease had no correlation with any tested antibody levels (P>0.05). Conclusion: MGFA classification has significant effects on distribution of AChR antibody level. Age and MGFA classification have positive correlation with AChR antibody level.

The response of glandular gastric transcriptome to T-2 toxin in chicks

This study was conducted to determine the effect of T-2 toxin on the transcriptome of the glandular stomach in chicks using RNA-sequencing (RNA-Seq). Four groups of 1-day-old Cobb male broilers (n = 4 cages/group, 6 chicks/cage) were fed a corn-soybean-based diet (control) and control supplemented with T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, for 2 weeks. The histological results showed that dietary supplementation of T-2 toxin at 3.0 and 6.0 mg/kg induced glandular gastric injury including serious inflammation, increased inflammatory cells, mucosal edema, and necrosis and desquamation of the epithelial cells in the glandular stomach of chicks. RNA-Seq analysis revealed that there were 671, 1393, and 1394 genes displayed ≥2 (P < 0.05) differential expression in the dietary supplemental T-2 toxin at 1.0, 3.0, and 6.0 mg/kg, respectively, compared with the control group. Notably, 204 differently expressed genes had shared similar changes among these three doses of T-2 toxin. GO and KEGG pathway analysis results showed that many genes involved in oxidation-reduction process, inflammation, wound healing/bleeding, and apoptosis/carcinogenesis were affected by T-2 toxin exposure. In conclusion, this study systematically elucidated toxic mechanisms of T-2 toxin on the glandular stomach, which might provide novel ideas to prevent adverse effects of T-2 toxin in chicks.

[Inhibition of Yiqi Jiedu formula on proliferation of nasopharyngeal carcinoma cells by MAPK/ERK signaling pathway]

To study the effect of aqueous extracts of Yiqi Jiedu formula (YQ) on the proliferation of CNE2 cells in human nasopharyngeal carcinoma, and investigate its mechanism to provide a new theoretical basis for the clinical application of YQ. CNE2 cells were treated with different concentrations (0.125, 0.25, 0.5, 0.25 g·L⁻¹) of YQ, positive control medicine (cisplatin 4.0 mg·L⁻¹), inhibitor PD98059 (50 μmol·L⁻¹), activator isoproterenol hydrochloride (20 μmol·L⁻¹), activator isoproterenol hydrochloride (ISO)+YQ 0.5 g·L⁻¹. Then cell labeling by using real-time analyzer (RTCA) and CCK 8 method were used to detect cell proliferation activity, and the half inhibitory concentration (IC₅₀) was calculated. The cell cycle distribution was detected by fluorescence double dye flow cytometry PI staining, and Western blot method was used to detect the expression levels of related protein and MAPK/ERK signaling pathway. The results of RTCA and CCK-8 test showed that as compared with the control group, YQ group could effectively inhibit the proliferation of CNE2 cells (P<0.01), with a dose and time dependence, and 48 h IC₅₀ value was 0.5 g·L⁻¹. The results of cell cycle showed that after 48 h of water extract treatment, the cell cycle was significantly changed, the proportion of G₀/G₁ was reduced, the ratio of G₂/M increased, and the cell cycle was in G₂/M period (P<0.01). Western blot results showed that after 48 h treatment with different concentrations of aqueous extract, cell cycle-related proteins cyclinD1, cyclinD3 and CDK2 expression levels were down-regulated; MAPK/ERK signaling pathway related protein p-c-Raf, p-MEK, p-ERK1/2 expression level significantly lower as compared with the control group (P<0.05). After adding activator and inhibitor in MAPK/ERK signaling pathway on this basis, the results showed that after adding activator ISO, cell proliferation was significantly higher than that in the Control group; the cycle related proteins cyclinD1, cyclinD3, and CDK2 expression levels were increased; at the same time, key protein p-c-Raf, p-MEK, p-ERK1/2 expression levels in the signal pathways were relatively increased. While after the addition of inhibitor PD98059, the cell proliferation was significantly lower than that in the Control group, and the expression level of corresponding protein was decreased, which was significantly different from the Control group (P<0.05). So YQ could block cell cycle and inhibit the proliferation of CNE2 cells mainly by reducing the expression of MAPK/ERK signaling pathway key protein p-c-Raf, p-MEK and p-ERK1/2.

Mouse Models for Studying Oral Cancer: Impact in the Era of Cancer Immunotherapy

Model systems for oral cancer research have progressed from tumor epithelial cell cultures to in vivo systems that mimic oral cancer genetics, pathological characteristics, and tumor-stroma interactions of oral cancer patients. In the era of cancer immunotherapy, it is imperative to use model systems to test oral cancer prevention and therapeutic interventions in the presence of an immune system and to discover mechanisms of stromal contributions to oral cancer carcinogenesis. Here, we review in vivo mouse model systems commonly used for studying oral cancer and discuss the impact these models are having in advancing basic mechanisms, chemoprevention, and therapeutic intervention of oral cancer while highlighting recent discoveries concerning the role of immune cells in oral cancer. Improvements to in vivo model systems that highly recapitulate human oral cancer hold the key to identifying features of oral cancer initiation, progression, and invasion as well as molecular and cellular targets for prevention, therapeutic response, and immunotherapy development.

[Evaluation of a high-intensity fluorescent fluorophage method for diagnosis of drug-resistance in tuberculosis]

Objective: To evaluate the high-intensity green fluorescent protein fluorophage Φ(2)GFP10 method for drug susceptibility testing of tuberculosis for isoniazid(INH), rifampin(RIF), and streptomycin(SM). Methods: A total of 128 clinical M. tuberculosis strains were isolated from patients with suspected drug-resistant tuberculosis visiting Beijing Chest Hospital (Beijing, China) from April to June 2014.All of the isolates were tested by the phage assay, while conventional drug susceptibility tests were performing on Lwenstein-Jensen culture medium as reference. Results: The sensitivities of Φ(2)GFP10 assay for INH, RIF, and SM resistance detection were 100.0%, 98.1%(53/54), and 92.6%(50/54), respectively, while their specificities were 84.8%(56/66), 91.9%(68/74), and 91.9%(68/74), respectively. The agreement between the phage assay and the conventional assay for detecting INH, RIF, and SM resistance was 0.92, 0.95 and 0.92, respectively. The Φ(2) GFP10-phage assay could be done within 2 days for RIF and SM, and 3 days for INH. Conclusions: The Φ(2)GFP10-phage method for drug susceptibility test is very sensitive and specific. The method has the potential to be a valuable, rapid and economical screening method for detecting drug-resistant tuberculosis.

Solvent-induced construction of two zinc supramolecular isomers: synthesis, framework flexibility, sensing properties, and adsorption of dye molecules

Solvent-induced construction of two zinc supramolecular isomerism, sensing properties and adsorption of dye molecules.

The reliability of the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) among dermatologists, rheumatologists and neurologists

BACKGROUND

Previous studies have shown that skin disease in dermatomyositis (DM) is best assessed using the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). Although the CDASI has been validated for use by dermatologists, it has not been validated for use by other physicians such as rheumatologists and neurologists, who also manage patients with DM and assess skin activity in clinical trials.

OBJECTIVES

To assess the reliability of the CDASI among dermatologists, rheumatologists and neurologists.

METHODS

Fifteen patients with cutaneous DM were assessed using the CDASI and the Physician Global Assessment (PGA) by five dermatologists, five rheumatologists and five neurologists.

RESULTS

The mean CDASI activity scores for dermatologists, rheumatologists and neurologists were 21·0, 21·8 and 20·8, respectively. These mean scores were not different among the specialists. The CDASI damage score means for dermatologists, rheumatologists and neurologists were 5·3, 7·0 and 4·8, respectively. The mean scores between dermatologists and rheumatologists were significantly different, but the means between dermatologists and neurologists were not. The intraclass correlation coefficients (ICCs) for interrater reliability for CDASI activity and damage were good to excellent for dermatologists and rheumatologists, and moderate to excellent for neurologists. The ICCs for intrarater reliability for CDASI activity and damage were excellent for dermatologists and rheumatologists and moderate to excellent for neurologists. The PGA displayed lower interrater and intrarater reliability relative to the CDASI.

CONCLUSIONS

Our results confirm the reliability of the CDASI when used by dermatologists and rheumatologists. The data for its use by neurologists were not as robust.

[Clinical value of contrast-enhanced ultrasound in evaluating portal hypertension in patients with decompensated liver cirrhosis]

OBJECTIVE

To investigate the correlation between contrast-enhanced ultrasound parameters and hepatic venous pressure gradient (HVPG), and to develop a new noninvasive method for the evaluation of portal hypertension in patients with decompensated liver cirrhosis.

METHODS

One-hundred patients with decompensated liver cirrhosis were examined by contrast-enhanced ultrasound, and the dynamic images were collected for offline analysis. The contrast arrival time was obtained in the hepatic artery (HA), portal vein (PV), and hepatic vein (HV), and HA-HV transit time (HA-HVTT) and PV-HV transit time (PV-HVTT) were calculated. At the same time, HVPG was measured within 24 hours after contrast-enhanced ultrasound, Pearson correlation analysis was performed between each parameter and HVPG, and the receiver operating characteristic (ROC) curve was also used for analysis.

RESULTS

HV arrival time (HVAT), HA-HVTT, and PV-HVTT were negatively correlated with HVPG (r = -0.385, -0.409, and -0.572, respectively). The area under the ROC curve (AUROC) was 0.903 for PV-HVTT < 2.5 s in judging HVPG≥ l0 mmHg in patients with decompensated liver cirrhosis, and the sensitivity and specificity were 74.4% and 89.5%, respectively. The AUROC was 0.861 for PV-HVTT < 1.5 s in judging HVPG≥l6 mmHg in these patients, and the sensitivity and specificity were 80.4% and 81.5%, respectively.

CONCLUSIONS

HVAT and intrahepatic transit time demonstrate negative linear correlations with HVPG in patients with decompensated liver cirrhosis, and among all parameters, PV-HVTT shows the strongest correlation with HVPG and can be used to determine and predict the severity of portal hypertension.

Anti-N-methyl-d-aspartate receptor encephalitis in a patient with neuromyelitis optica spectrum disorders

We described a female patient with anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis occurring sequentially with neuromyelitis optica spectrum disorders (NMOSD). The 19-year-old patient initially presented a diencephalic syndrome with aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) and brain lesions which involving bilateral medial temporal lobes and periependymal surfaces of the third ventricle on magnetic resonance imaging (MRI). Ten months later, the patient developed cognitive impairment, psychiatric symptoms and dyskinesia with left basal ganglia lesions on brain MRI. Meanwhile, the anti-NMDAR antibodies were positive in the patient's serum and cerebrospinal fluid, while the screening tests for an ovarian teratoma and other tumors were all negative. Hence, the patient was diagnosed NMOSD and anti-NMDAR encephalitis followed by low-dose rituximab treatment with a good response. This case was another evidence for demyelinating syndromes overlapping anti-NMDAR encephalitis in Chinese patients.

Pseudoalteromonas xiamenensis sp. nov., a marine bacterium isolated from coastal surface seawater

A Gram-negative, oxidase- and catalase-positive, rod-shaped, non-spore-forming, motile, aerobic bacterium, designated Y2(T), was isolated from surface seawater of Yundang Lake, Xiamen, China. The strain was able to grow in the presence of 0.5-6.0% NaCl (optimum 1.0-1.5%), at pH 5-10 (optimum pH 8) and at 10-40 °C (optimum 25 °C). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Y2(T) belongs to the genus Pseudoalteromonas, with the highest sequence similarity of 94.9% to Pseudoalteromonas tunicata D2(T); within the genus Pseudoalteromonas, it showed the lowest similarity of 92.8% to Pseudoalteromonas denitrificans ATCC 43337(T). The G+C content of the chromosomal DNA of strain Y2(T) was 45.1 mol%. The predominant fatty acids were summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c), C(16 : 0), C(12 : 0) 3-OH and summed feature 8 (C(18 : 1)ω6c and/or C(18 : 1)ω7c). The only respiratory quinone detected was Q-8. Based on the phylogenetic and phenotypic characteristics, strain Y2(T) represents a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas xiamenensis sp. nov. is proposed; the type strain is Y2(T) ( = CGMCC 1.12157(T) = JCM 18779(T)).

Phoenixin: a novel peptide in rodent sensory ganglia

Phoenixin-14 amide, herein referred to as phoenixin, is a newly identified peptide from the rat brain. Using a previously characterized rabbit polyclonal antiserum against phoenixin, enzyme-immunoassay detected a high level (>4.5 ng/g tissue) of phoenixin-immunoreactivity (irPNX) in the rat spinal cords. Immunohistochemical studies revealed irPNX in networks of cell processes in the superficial dorsal horn, spinal trigeminal tract and nucleus of the solitary tract; and in a population of dorsal root, trigeminal and nodose ganglion cells. The pattern of distribution of irPNX in the superficial layers of the dorsal horn was similar to that of substance P immunoreactivity (irSP). Double-labeling the dorsal root ganglion sections showed that irPNX and irSP express in different populations of ganglion cells. In awake mice, intrathecal injection of phoenixin (1 or 5 μg) did not significantly affect the tail-flick latency as compared to that in animals injected with artificial cerebrospinal fluid (aCSF). Intrathecal administration of phoenixin (0.5, 1.25 or 2.5 μg) significantly reduced the number of writhes elicited by intraperitoneal injection of acetic acid (0.6%, 0.3 ml/30 g) as compared to that in mice injected with aCSF. While not affecting the tail-flick latency, phoenixin antiserum (1:100) injected intrathecally 10 min prior to the intraperitoneal injection of acetic acid significantly increased the number of writhes as compared to mice pre-treated with normal rabbit serum. Intrathecal injection of non-amidated phoenixin (2.5 μg) did not significantly alter the number of writhes evoked by acetic acid. Our result shows that phoenixin is expressed in sensory neurons of the dorsal root, nodose and trigeminal ganglia, the amidated peptide is bioactive, and exogenously administered phoenixin may preferentially suppress visceral as opposed to thermal pain.

Overexpression of Helicobacter pylori VacA N-terminal fragment induces proinflammatory cytokine expression and apoptosis in human monocytic cell line through activation of NF-κB

Vacuolating cytotoxin (VacA) is an important virulence factor in the pathogenesis of Helicobacter pylori-related diseases. The aim of this study was to investigate the function of the amino-terminal 476 residue fragment (p52) of VacA and the possible molecular mechanisms responsible for its induction of proinflammatory cytokines secretion and apoptosis. Human acute monocytic leukemia cell line THP-1 was used as an in vitro model to study proinflammatory cytokines secretion and apoptosis induced by transfection of a recombinant plasmid encoding the amino-terminal 476 residue fragment (p52) of VacA. The results showed that VacA p52 overexpression induced the production of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), nitric oxide, and reactive oxygen species in THP-1 cells in a time-dependent manner. VacA p52 overexpression also promoted THP-1 cells apoptosis. In addition, VacA p52 triggered the activation of nuclear factor kappa B (NF-κB), indicating a possible mechanism for its induction of proinflammatory cytokines secretion and cell apoptosis. Our study demonstrated that the induction of cytokines secretion and apoptosis by VacA p52 in THP-1 cells could be mediated through activation of nuclear factor kappa B.

Overexpression of Helicobacter pylori VacA N-terminal fragment induces proinflammatory cytokine expression and apoptosis in human monocytic cell line through activation of NF-κB

Vacuolating cytotoxin (VacA) is an important virulence factor in the pathogenesis of Helicobacter pylori-related diseases. The aim of this study was to investigate the function of the amino-terminal 476 residue fragment (p52) of VacA and the possible molecular mechanisms responsible for its induction of proinflammatory cytokines secretion and apoptosis. Human acute monocytic leukemia cell line THP-1 was used as an in vitro model to study proinflammatory cytokines secretion and apoptosis induced by transfection of a recombinant plasmid encoding the amino-terminal 476 residue fragment (p52) of VacA. The results showed that VacA p52 overexpression induced the production of tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), nitric oxide, and reactive oxygen species in THP-1 cells in a time-dependent manner. VacA p52 overexpression also promoted THP-1 cells apoptosis. In addition, VacA p52 triggered the activation of nuclear factor kappa B (NF-κB), indicating a possible mechanism for its induction of proinflammatory cytokines secretion and cell apoptosis. Our study demonstrated that the induction of cytokines secretion and apoptosis by VacA p52 in THP-1 cells could be mediated through activation of nuclear factor kappa B.

Irisin-immunoreactivity in neural and non-neural cells of the rodent

Irisin is a recently identified myokine secreted from the muscle in response to exercise. In the rats and mice, immunohistochemical studies with an antiserum against irisin peptide fragment (42-112), revealed that irisin-immunoreactivity (irIRN) was detected in three types of cells; namely, skeletal muscle cells, cardiomyocytes, and Purkinje cells of the cerebellum. Tissue sections processed with irisin antiserum pre-absorbed with the irisin peptide (42-112) (1 μg/ml) showed no immunoreactivity. Cerebellar Purkinje cells were also immunolabeled with an antiserum against fibronectin type II domain containing 5 (FNDC5), the precursor protein of irisin. Double-labeling of cerebellar sections with irisin antiserum and glutamate decarboxylase (GAD) antibody showed that nearly all irIRN Purkinje cells were GAD-positive. Injection of the fluorescence tracer Fluorogold into the vestibular nucleus of the rat medulla retrogradely labeled a population of Purkinje cells, some of which were also irIRN. Our results provide the first evidence of expression of irIRN in the rodent skeletal and cardiac muscle, and in the brain where it is present in GAD-positive Purkinje cells of the cerebellum. Our findings together with reports by others led us to hypothesize a novel neural pathway, which originates from cerebellum Purkinje cells, via several intermediary synapses in the medulla and spinal cord, and regulates adipocyte metabolism.

Abscisic acid plays an important role in the regulation of strawberry fruit ripening

The plant hormone abscisic acid (ABA) has been suggested to play a role in fruit development, but supporting genetic evidence has been lacking. Here, we report that ABA promotes strawberry (Fragaria ananassa) fruit ripening. Using a newly established Tobacco rattle virus-induced gene silencing technique in strawberry fruit, the expression of a 9-cis-epoxycarotenoid dioxygenase gene (FaNCED1), which is key to ABA biosynthesis, was down-regulated, resulting in a significant decrease in ABA levels and uncolored fruits. Interestingly, a similar uncolored phenotype was observed in the transgenic RNA interference (RNAi) fruits, in which the expression of a putative ABA receptor gene encoding the magnesium chelatase H subunit (FaCHLH/ABAR) was down-regulated by virus-induced gene silencing. More importantly, the uncolored phenotype of the FaNCED1-down-regulated RNAi fruits could be rescued by exogenous ABA, but the ABA treatment could not reverse the uncolored phenotype of the FaCHLH/ABAR-down-regulated RNAi fruits. We observed that down-regulation of the FaCHLH/ABAR gene in the RNAi fruit altered both ABA levels and sugar content as well as a set of ABA- and/or sugar-responsive genes. Additionally, we showed that exogenous sugars, particularly sucrose, can significantly promote ripening while stimulating ABA accumulation. These data provide evidence that ABA is a signal molecule that promotes strawberry ripening and that the putative ABA receptor, FaCHLH/ABAR, is a positive regulator of ripening in response to ABA.

High-Aspect-Ratio Aluminum Borate Nanowire Bundles Supported by Sucrose

High-aspect-ratio and single-crystal aluminum borate (Al(18)B(4)O(33)) nanowire bundles with an ordered orientation were synthesized by using an innovative sucrose-assisted growth process. The process involves the dehydration and polycondensation of aluminum borate-sucrose solution to form a highly viscous precursor. The sucrose plays a crucial role in the growth of the nanowire bundles by supporting as a polymeric substrate and a type of adhesive template. Electron microscopy was used to characterize the high-aspect-ratio nanowire bundles. A possible growth mechanism for the nanowire bundles is proposed.

Characterization of the neurotrophic interaction between nerve growth factor and secreted alpha-amyloid precursor protein

The expression and secretion of amyloid precursor protein (beta APP) is increased in rat cerebral cortices that have been denervated by subcortical lesions of the nucleus basalis of Meynert. The physiological role of the secreted beta APP in response to this injury has not been established. We have previously shown that secreted beta APP produced by alpha-secretase activity (sAPP(alpha)) potentiates the neuritogenic activity of nerve growth factor (NGF) in vitro on naive PC12 cells. In this investigation, we have further characterized the neurotrophic interaction of NGF and sAPP(alpha) using differentiated PC12 cells and rat primary cortical neurons. NGF required the expression of beta APP to maintain a neuronal phenotype. Reduction of endogenous beta APP expression by introduction of antisense oligonucleotides in the presence of NGF resulted in loss of neurites from differentiated PC12 cells but no apparent cell death. Addition of exogenous sAPP(alpha) (60--200 pM) potentiated the protective activity of NGF in serum-deprived differentiated PC12 cells as determined by retention of neurites and cell viability. In addition, exogenous sAPP(alpha) increased neuron viability in both short-term (3 days) cortical neuron cultures grown in the absence of serum and in long-term (9 days) cultures grown with serum. Disruption of the insulin signaling pathway by reduction of IRS-1 expression inhibited the ability of sAPP(alpha) to potentiate neurotrophic activity. These observations suggest that sAPP(alpha) acts as an injury-induced neurotrophic factor that interacts with NGF to enhance neuronal viability using the insulin signaling pathway.

Death of PC12 cells and hippocampal neurons induced by adenoviral-mediated FAD human amyloid precursor protein gene expression

We used adenoviral-mediated gene transfer of human amyloid precursor proteins (h-APPs) to evaluate the role of various h-APPs in causing neuronal cell death. We were able to infect PC12 cells with very high efficiency because approximately 90% of the cells were cytochemically positive for beta-galactosidase activity when an adenoviral vector containing LacZ cDNA was used to infect cells. Cells infected with adenovirus containing h-APP cDNA showed high-level transcription and expression of h-APP as measured by reverse transcriptase-polymerase chain reaction and Western immunoblot analyses, respectively. Intracellular and extracellular levels of h-APP were elevated approximately 17-and 24-fold in cultures infected with recombinant adenovirus containing wild-type mutant and 13- and 17-fold with V642F mutant. No elevation in h-APP was seen in cultures infected with antisense h-APP or null adenovirus. H-APP levels were maximal 3 days after infection. Overexpression of V642F mutant h-APP in PC12 cells and hippocampal neurons resulted in about a twofold increase in death compared with overexpression of wild-type h-APP. These results demonstrate the usefulness of recombinant adenoviral mediated gene transfer in cell culture studies and suggest that overexpression of a familial Alzheimer's disease mutant APP may be toxic to neuronal cells.

Effects of PS1 deficiency on membrane protein trafficking in neurons

We have examined the trafficking and metabolism of the beta-amyloid precursor protein (APP), an APP homolog (APLP1), and TrkB in neurons that lack PS1. We report that PS1-deficient neurons fail to secrete Abeta, and that the rate of appearance of soluble APP derivatives in the conditioned medium is increased. Remarkably, carboxyl-terminal fragments (CTFs) derived from APP and APLP1 accumulate in PS1-deficient neurons. Hence, PS1 plays a role in promoting intramembrane cleavage and/or degradation of membrane-bound CTFs. Moreover, the maturation of TrkB and BDNF-inducible TrkB autophosphorylation is severely compromised in neurons lacking PS1. We conclude that PS1 plays an essential role in modulating trafficking and metabolism of a selected set of membrane and secretory proteins in neurons.

Rapid ATP loss caused by methamphetamine in the mouse striatum: relationship between energy impairment and dopaminergic neurotoxicity

To study the relationship between energy impairment and the effects of d-methamphetamine (METH) on dopaminergic neurons, ATP and dopamine levels were measured in the brain of C57BL/6 mice treated with either a single or four injections of METH (10 mg/kg, i.p.) at 2-h intervals. Neither striatal ATP nor dopamine concentrations changed after a single injection of METH, but both were significantly decreased 1.5 h after the multiple-dose regimen. The effects of METH on ATP levels appear to be selective for the striatum, as ATP concentrations were not affected in the cerebellar cortex and hippocampus after either a single or multiple injections of METH. In a second set of experiments, an intraperitoneal injection of 2-deoxyglucose (2-DG; 1 g/kg), an inhibitor of glucose uptake and utilization, was given 30 min before the third and fourth injections of METH. 2-DG significantly potentiated METH-induced striatal ATP loss at 1.5 h and dopamine depletions at 1.5 h and 1 week. These results indicate that a toxic regimen of METH selectively causes striatal energy impairment and raise the possibility that perturbations of energy metabolism play a role in METH-induced dopaminergic neurotoxicity.

Chick sympathetic neurons in culture respond differentially to nerve growth factor and conditioned medium from activated splenic lymphocytes

Chicken splenic cells, stimulated by concanavalin A, secreted a factor or factors into the culture medium which supported the survival of neurons from sympathetic ganglia of chick embryos. The effect of this conditioned medium (CM) was similar to the effect of nerve growth factor (NGF). However, the enhanced survival effect of CM was unaffected by K-252a, a protein kinase inhibitor which completely abolished the effect of NGF. 6-Thioguanine, an inhibitor of NGF-activated protein kinase N, blocked the survival effects of both NGF and CM on sympathetic neurons, but a dose required for the half-maximal inhibition for the survival effect of CM was 10 times higher than that for NGF. H-7, an inhibitor of protein kinase C, did not block the effect of either CM or NGF. On the other hand, the survival effect of both CM and NGF was blocked to the same extent by 5'-deoxy-5'-methylthioadenosine and LiCl. These results suggest that activated splenic cells secreted neuronal survival-promoting factor(s) into CM and that the cellular mechanisms promoting neuronal survival by CM are different from those promoting neuronal survival induced by NGF.