A novel platelet risk score for stratifing the tumor immunophenotypes, treatment responses and prognosis in bladder carcinoma: results from real-world cohorts.

Background: Although the durable efficacy of immune checkpoint inhibitors (ICIs) in BLCA has been confirmed in numerous studies, not all patients benefit from their application in the clinic. Platelets are increasingly being found to be closely associated with cancer progression and metastasis; however, their comprehensive role in BLCA remains unclear. Methods: We comprehensively explored platelet expression patterns in BLCA patients using an integrated set of 244 related genes. Correlations between these platelet patterns with tumor microenvironment (TME) subtypes, immune characteristics and immunotherapy efficacies were explored. In addition, a platelet risk score (PRS) was generated for individual prognosis and verified the ability to predict prognosis, precise TME phenotypes, and immunotherapy efficacies. Results: Genes were clustered into two patterns that represented different TME phenotypes and had the ability to predict immunotherapy efficacy. We constructed a PRS that could predict individual prognosis with satisfactory accuracy using TCGA-BLCA. The results remained consistent when PRS was validated in the GSE32894 and Xiangya cohort. Moreover, we found that our PRS was positively related to tumor-infiltrating lymphocytes (TILs) in the TCGA-BLCA and Xiangya cohort. As expected, patients with higher PRS exhibited more sensitive to immunotherapy than patients with lower PRS. Finally, we discovered that a high PRS indicated a basal subtype of BLCA, whereas a low PRS indicated a luminal subtype. Conclusion: Platelet-related genes could predict TME phenotypes in BLCA. We constructed a PRS that could predict the TME, prognosis, immunotherapy efficacy, and molecular subtypes in BLCA.

Baicalin regulates TLR4/IκBα/NFκB signaling pathway to alleviate inflammation in Doxorubicin related cardiotoxicity.

Cancers and the toxic and side effects of their treatment have always been a major problem for human beings. Doxorubicin (DOX) is one of the classical anthracycline antineoplastic drugs, but it can cause different degrees of heart damage and even serious heart failure. The incidence of myocardial toxicity increased significantly when the cumulative dose of the drug was more than 550 mg/m2, and the relevant mechanism was related to the inflammatory reaction, reactive oxygen species and the apoptosis of cardiomyocytes in the myocardium. Relevant studies have shown that baicalein (Ba) can inhibit NFκB-related inflammatory signaling pathway protects cardiac function, but whether it can inhibit DOX induced cardiotoxicity has not been reported. Therefore, in animal studies, we explored the effects of doxorubicin and baicalein on cardiac function, TLR4/IκBα/NFκB signaling pathway and related inflammatory indicators in rats. In cell experiments, by silencing or overexpressing TLR4, we explored whether baicalein could achieve anti-inflammatory effect through regulating TLR4/IκBα/NFκB signaling pathway and ultimately inhibit doxorubicin induced cardiotoxicity.

Higher Trait Impulsivity and Altered Frontostriatal Connectivity in Betel-Quid Dependent Individuals.

Objective: Betel quid dependency (BQD) is characterized by functional and structural brain alterations. Trait impulsivity may influence substance dependence by impacting its neurobiological underpinnings in the frontostriatal circuit. However, little is known about the trait impulsivity and its neural correlates in individuals with BQD. Methods: Forty-eight participants with BQD and 22 normal controls (NCs) were recruited and scanned on a 3T MRI scanner. Barratt impulsiveness scale (BIS) was used to measure trait impulsivity: motor, attention, and no plan impulsivity. We used voxel-based morphometry (VBM) to assess the relationship between trait impulsivity and gray matter volumes. The relevant clusters identified were served as regions of interest (ROI) seeds. The whole-volume psycho-physiological interactions (PPI) analysis was used to investigate the changes of functional connectivity related to ROI seeds in the cue-reactivity task condition (BQ and control images). Results: Behaviorally, the BQD group showed significantly higher trait impulsivity including motor and no plan impulsivity than the NCs group. VBM analyses showed that motor impulsivity was negatively associated with gray matter volume of right caudate in the whole sample. No difference in gray matter volume between the two groups was observed. PPI analyses showed that there was a significantly decreased functional connectivity between the right caudate and right dorsolateral prefrontal cortex (DLPFC) when watching BQ related images than control images in individuals with BQD. Furthermore, functional connectivity between the right caudate and right DLPFC was negatively correlated with BQ dependency scores. Conclusions: Our study demonstrated the structural basis of trait impulsivity in the caudate and provided evidence for abnormal interactions within frontostriatal circuitsin individuals with BQD, which may provide insight into the selection of potential novel therapeutic targets for the treatment of BQ dependency.

Demands and countermeasures for outpatients and emergency patients during the outbreak of coronavirus disease 2019 in large general hospital. / 大型综合性医院2019å† çŠ¶ç— æ¯’ç— ç–«æƒ æœŸé—´é—¨æ€¥è¯Šæ‚£è€ å°±è¯Šéœ€æ±‚åŠåº”å¯¹.

OBJECTIVES: To discuss the demands and countermeasures for outpatients and emergency patients during the outbreak of coronavirus disease 2019 (COVID-19) in large general hospital. METHODS: By analyzing patients' demands, outpatient service system and emergency system complemented each other with the help of "internet medical" to provide online medical treatment, self-diagnosed pneumonia program, online pharmacies, outpatient appointment and online pre-examination services, open green channels for special patients, and to provide referral services for critical patients. The COVID-19 suspected patients and other common fever patients were separated from other patients. RESULTS: From January 28 to March 1, we have received 26 000 patients online, 1 856 special patients, 2 929 suspected patients and common fever patients including 31 confirmed patients, 0 case of misdiagnosis and cross-infection. CONCLUSIONS: Targeting patient's demands and taking appropriate measures are effective on meeting the needs of outpatients' and emergency patients' medical services.

Knowledge, attitude, and practice survey regarding coronavirus disease 2019 among residents in Hunan Province. / æ¹–å—çœå± æ°‘2019å† çŠ¶ç— æ¯’ç— çŸ¥è¯†ã€æ€åº¦ä¸Žåº”å¯¹è¡Œä¸º.

OBJECTIVES: To evaluate residents' knowledge, attitude and behavior towards coronavirus disease 2019 (COVID-19) in Hunan Province, and to explore the factors influencing behaviors. METHODS: A self-designed questionnaire was used to conduct an online survey for 4 139 Hunan residents. The contents included general population information, residents' knowledge, attitude and practice to COVID-19. RESULTS: Mean scores of knowledge, attitude, and behavior were 29.82±3.16, 6.71±1.12, and 14.93±1.45, respectively. Residents had the highest score of major symptoms of COVID-19 (3.96±0.39), but the lowest was the main transmission routes (3.47±0.89). A total of 22.68% of the residents were very or relatively afraid of the outbreak, but 95.22% of the residents had confidence in defeating COVID-19. In behavior dimension, "handling of suspicious symptoms" had the lowest score (3.58±0.75). The behavior implementation rate of "keep the surfaces of household items clean" (80.50%), "doing more exercise, reasonable diet, working and resting regularly" (84.59%), and "avoid hand contacting with eyes, mouth or nose" (89.51%) were relatively low. Pearson correlation coefficient showed that the knowledge, attitude, and practices score were correlated with each other (knowledge vs behavior: r=0.366; knowledge vs attitude: r=0.041; attitude vs behavior: r=0.100; all P<0.05). Multiple linear regression analysis showed that the knowledge, attitude and behavior on COVID-19 were mostly influenced by education background (all P<0.05), and the independent factors affecting behavior included knowledge and attitude, gender, permanent residence, education background (all P<0.05). CONCLUSIONS: Residents in Hunan Province have a good knowledge, attitude, and behavior to COVID-19. Nevertheless there are still weak links to be improved in all dimensions. It is necessary to strengthen knowledge and behavior of family protection, and care for residents' psychological health, especially persons with low education degree, male and rural residents.

Improved Efficiency of Perovskite Light-Emitting Diodes Using a Three-Step Spin-Coated CH3NH3PbBr3 Emitter and a PEDOT:PSS/MoO3-Ammonia Composite Hole Transport Layer.

High efficiency perovskite light-emitting diodes (PeLEDs) using PEDOT:PSS/MoO3-ammonia composite hole transport layers (HTLs) with different MoO3-ammonia ratios were prepared and characterized. For PeLEDs with one-step spin-coated CH3NH3PbBr3 emitter, an optimal MoO3-ammonia volume ratio (0.02) in PEDOT:PSS/MoO3-ammonia composite HTL presented a maximum luminance of 1082 cd/m2 and maximum current efficiency of 0.7 cd/A, which are 82% and 94% higher than those of the control device using pure PEDOT:PSS HTL respectively. It can be explained by that the optimized amount of MoO3-ammonia in the composite HTLs cannot only facilitate hole injection into CH3NH3PbBr3 through reducing the contact barrier, but also suppress the exciton quenching at the HTL/CH3NH3PbBr3 interface. Three-step spin coating method was further used to obtain uniform and dense CH3NH3PbBr3 films, which lead to a maximum luminance of 5044 cd/m2 and maximum current efficiency of 3.12 cd/A, showing enhancement of 750% and 767% compared with the control device respectively. The significantly improved efficiency of PeLEDs using three-step spin-coated CH3NH3PbBr3 film and an optimum PEDOT:PSS/MoO3-ammonia composite HTL can be explained by the enhanced carrier recombination through better hole injection and film morphology optimization, as well as the reduced exciton quenching at HTL/CH3NH3PbBr3 interface. These results present a promising strategy for the device engineering of high efficiency PeLEDs.

Elevated Prevalence of Abnormal Glucose Metabolism and Other Endocrine Disorders in Patients with ß-Thalassemia Major: A Meta-Analysis.

BACKGROUND: Endocrinopathies are common in patients with ß-thalassemia major despite parenteral iron chelation therapy with deferoxamine. Prevalence of abnormal glucose metabolism in previous studies was controversial. The aim of this study was to discuss the prevalence of abnormal glucose metabolism in ß-thalassemia major based on a meta-analysis. METHODS: PubMed, ScienceDirect, Springerlink, Ovid, Web of Science, MEDLINE, Wanfang database, and Chinese National Knowledge Internet were searched for relevant articles. Two authors selected the articles according to the inclusion criteria and then extracted the data. The prevalence of diabetes mellitus (DM) in ß-thalassemia major was defined as the primary outcome. The prevalence with the 95% confidence interval (95%CI) was used to evaluate the proportion of abnormal glucose metabolism and other endocrine disorders in patients with ß-thalassemia major. Subgroup analyses were applied to explore the prevalence in different regions. Sensitivity analysis and publication bias assessment were also conducted. RESULTS: A total of 44 studies with 16605 cases were included in this analysis. Diabetes mellitus was present in 6.54% (95% CI: 5.30%-7.78%). The fixed subgroup study revealed that the region with the highest prevalence was the Middle East (prevalence= 7.90%, 95% CI: 5.75%-10.05%). The accumulated meta-analysis revealed that the prevalence of DM in ß-thalassemia major was relatively steady in each year. The prevalence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and other endocrine disorders in ß-thalassemia major was 17.21% (95% CI: 8.43%-26.00%), 12.46% (95% CI: 5.98%-18.94%), and 43.92% (95% CI: 37.94%-49.89%), respectively. Sensitivity analysis showed that the pooled results were robust; publication bias assessment revealed that there was no significant evidence that the pooled results were influenced by publication bias. CONCLUSION: High prevalence of endocrine disorders involving abnormal glucose metabolism was detected in ß-thalassemia major. Treatment and prevention measurements may be necessary to prevent growth and endocrine problems.

Effects of Charge Transport Materials on Blue Fluorescent Organic Light-Emitting Diodes with a Host-Dopant System.

High efficiency blue fluorescent organic light-emitting diodes (OLEDs), based on 1,3-bis(carbazol-9-yl)benzene (mCP) doped with 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi), were fabricated using four different hole transport layers (HTLs) and two different electron transport layers (ETLs). Fixing the electron transport material TPBi, four hole transport materials, including 1,1-Bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC), N,N'-Di(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4'-diamine(NPB), 4,4'-Bis(N-carbazolyl)-1,1,-biphenyl (CBP) and molybdenum trioxide (MoO3), were selected to be HTLs, and the blue OLED with TAPC HTL exhibited a maximum luminance of 2955 cd/m2 and current efficiency (CE) of 5.75 cd/A at 50 mA/cm2, which are 68% and 62% higher, respectively, than those of the minimum values found in the device with MoO3 HTL. Fixing the hole transport material TAPC, the replacement of TPBi ETL with Bphen ETL can further improve the performance of the device, in which the maximum luminance can reach 3640 cd/m2 at 50 mA/cm2, which is 23% higher than that of the TPBi device. Furthermore, the lifetime of the device is also optimized by the change of ETL. These results indicate that the carrier mobility of transport materials and energy level alignment of different functional layers play important roles in the performance of the blue OLEDs. The findings suggest that selecting well-matched electron and hole transport materials is essential and beneficial for the device engineering of high-efficiency blue OLEDs.

An Evaluation of HTML5 and WebGL for Medical Imaging Applications.

Despite the fact that a large number of web applications are used in the medical community, there are still certain technological challenges that need to be addressed, for example, browser plug-ins and efficient 3D visualization. These problems make it necessary for a specific browser plug-in to be preinstalled on the client side when launching applications. Otherwise, the applications fail to run due to the lack of the required software. This paper presents the latest techniques in hypertext markup language 5 (HTML5) and web graphics library (WebGL) for solving these problems and an evaluation of the suitability of the combination of HTML5 and WebGL for the development of web-based medical imaging applications. In this study, a comprehensive medical imaging application was developed using HTML5 and WebGL. This application connects to the medical image server, runs on a standard personal computer (PC), and is easily accessible via a standard web browser. The several functions required for radiological interpretation were implemented, for example, navigation, magnification, windowing, and fly-through. The HTML5-based medical imaging application was tested on major browsers and different operating systems over a local area network (LAN) and a wide area network (WAN). The experimental results revealed that this application successfully performed two-dimensional (2D) and three-dimensional (3D) functions on different PCs over the LAN and WAN. Moreover, it demonstrated an excellent performance for remote access users, especially over a short time period for 3D visualization and a real-time fly-through navigation. The results of the study demonstrate that HTML5 and WebGL combination is suitable for the development of medical imaging applications. Moreover, the advantages and limitations of these technologies are discussed in this paper.

Correlations among Psychological Resilience, Self-Efficacy, and Negative Emotion in Acute Myocardial Infarction Patients after Percutaneous Coronary Intervention.

OBJECTIVE: We investigated the influencing factors of the psychological resilience and self-efficacy of acute myocardial infarction (AMI) patients after percutaneous coronary intervention (PCI) and the relationships of psychological resilience and self-efficacy with negative emotion. METHODS: Eighty-eight participants were enrolled. Psychological resilience, self-efficacy, and negative emotion were assessed with the Psychological Resilience Scale, Self-Efficacy Scale, Zung Self-Rating Anxiety Scale (SAS), and Zung Self-Rating Depression Scale (SDS), respectively. Furthermore, the relationships of psychological resilience and self-efficacy with negative emotion were investigated. RESULTS: The average scores of psychological resilience, self-efficacy, anxiety, and depression were 70.08 ± 13.26, 21.56 ± 9.66, 53.68 ± 13.10, and 56.12 ± 12.37, respectively. The incidences of anxiety and depression were 23.90% (21/88) and 28.40% (25/88), respectively. The psychological resilience and self-efficacy scores of AMI patients after PCI varied significantly with age and economic status. SAS scores and SDS scores were significantly negatively correlated with psychological resilience and self-efficacy. CONCLUSION: Negative emotions in AMI patients after PCI are closely related to psychological resilience and self-efficacy. Therefore, anxiety and depression could be alleviated by improving the psychological resilience and self-efficacy of patients undergoing PCI, thus improving patients' quality of life.

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment.

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75°. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm(2), respectively, has decreased the CA to near 15°, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer's surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm(2) and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103°. The XPS results indicate ArF laser induced formation of Si-(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

Carrier-induced fast wavelength switching in tunable V-cavity laser with quantum well intermixed tuning section.

We report on the fast wavelength switching in V-cavity laser (VCL) with quantum well intermixed tuning section. The laser wavelength can be switched between 32 channels at 100 GHz spacing using a single electrode control. The fabrication process involves a quantum well intermixing (QWI) process using KrF laser irradiation and rapid thermal annealing (RTA). The tuning current is less than 40 mA, much lower than previously demonstrated tunable VCL based on electro-thermal-optic effect. The wavelength switching is also faster by three orders of magnitude. The dynamic switching characteristics between two channels with different numbers of intermediate channels are investigated. It shows that the switching time is about 1 ns between adjacent channels and increases up to 12 ns with increasing number of intermediate channels.

[Expression of fibrillin-1 in congenital bicuspid aortic valves].

OBJECTIVE: To detect the expression of fibrillin-1 in congenital bicuspid aortic valves, and to investigate the molecular mechanism of congenital bicuspid aortic valves. METHODS: Specimens of aortic valve were obtained from 12 pediatric patients with congenital bicuspid aortic valve, 11 boys and 1 girl, aged 16.7 (10 - 18), including 5 cases of aortic stenosis (AS), 8 of aortic insufficiency (AI), and 1 of AS and AI, undergoing valve replacement, 8 children who died accidentally without cardiovascular system and collagen system diseases, 6 boys and 2 girls, aged 9.1 (1 - 17), collected in autopsy [normal (tricuspid) aortic valve controls], and 18 pediatric patients of rheumatic valvular heart disease with diseased tricuspid aortic valves who underwent aortic valve replacement, 13 boys and 5 girls, aged 16.5 (12 - 18) (rheumatic valvular heart disease controls). HE staining and light microscopy were conducted. Immunohistochemistry was used to detect the expression of fibrillin-1 in the aortic valves. RESULTS: Microscopy showed that the tissue structure of the congenital bicuspid aortic valves was unclear with hyperplasia of fibrous tissue. The grey degree value of fibrillin-1 of the congenital bicuspid aortic valve group was 170 +/- 10, significantly lower than those of normal aortic valve group and diseased tricuspid aortic valve group (126 +/- 8 and 73 +/- 16 respectively, both P < 0.05). There were not significant difference in the grey degree value of fibrillin-1 among the patients of congenital bicuspid aortic valves with AS, AI, and AS + AI (167 +/- 6, 171 +/- 8, and 168 +/- 6 respectively). CONCLUSION: The expression of fibrillin-1 is significantly reduced in congenital bicuspid aortic valves which may contribute to the morphological changes of the aortic valve leaflets and their resultant functional failure in congenital bicuspid aortic valves.

[Azoospermia factor microdeletion on Y chromosome in patients with idiopathic azoospermia or severe oligozoospermia].

OBJECTIVE: To investigate the correlation between male infertility and Y chromosome microdeletions of azoospermia factor (AZF) regions, and to establish a reliable genetic diagnosis in idiopathic infertile male patients with azoospermia or severe oligozoospermia. METHODS: Multiplex PCR amplification of 6 sequence-tagged sites in AZF regions of the Y chromosome was examined among 100 normal karyotype male patients with azoospermia or oligozoospermia. RESULTS: Four patients (4%) had Y chromosome microdeletions, the microdeletions of 3 patients were idiopathic azoospermic and those of the other 1 patient were secretory azoospermia. CONCLUSION: The PCR-based Y chromosome microdeletion screening is simple and effective in the diagnosis of patients with severe male infertility. Microdeletion of Y chromosome is one of the major causes of severe dyszooospermia.

Effects of chronic multiple stress on learning and memory and the expression of Fyn, BDNF, TrkB in the hippocampus of rats.

BACKGROUND: The effect of chronic stress on cognitive functions has been one of the hot topics in neuroscience. But there has been much controversy over its mechanism. The aim of this study was to investigate the effects of chronic multiple stress on spatial learning and memory as well as the expression of Fyn, BDNF and TrkB in the hippocampus of rats. METHODS: Adult rats were randomly divided into control and chronic multiple stressed groups. Rats in the multiple stressed group were irregularly and alternatively exposed to situations of vertical revolution, sleep expropriation and restraint lasting for 6 weeks, 6 hours per day with night illumination for 6 weeks. Before and after the period of chronic multiple stresses, the performance of spatial learning and memory of all rats was measured using the Morris Water Maze (MWM). The expression of Fyn, BDNF and TrkB proteins in the hippocampus was assayed by Western blotting and immunohistochemical methods. The levels of Fyn and TrkB mRNAs in the hippocampus of rats were detected by RT-PCR technique. RESULTS: The escape latency in the control group and the stressed group were 15.63 and 8.27 seconds respectively. The performance of spatial learning and memory of rats was increased in chronic multiple stressed group (P < 0.05). The levels of Fyn, BDNF and TrkB proteins in the stressed group were higher than those of the control group (P < 0.05). The results of immunoreactivity showed that Fyn was present in the CA3 region of the hippocampus and BDNF positive particles were distributed in the nuclei of CA1 and CA3 pyramidal cells as well as DG granular cells. Quantitative analysis indicated that level of Fyn mRNA was also upregulated in the hippocampus of the stressed group (P < 0.05). CONCLUSIONS: Chronic multiple stress can enhance spatial learning and memory function of rats. The expression of Fyn, BDNF and TrkB proteins and the level of Fyn mRNA are increased in the stessed rat hippocampus. These suggest that Fyn and BDNF/TrkB signal transduction pathways may participate in the process of the enhanced learning and memory during chronic multiple stress.

Changes of learning, memory and levels of CaMKII, CaM mRNA, CREB mRNA in the hippocampus of chronic multiple-stressed rats.

BACKGROUND: The effect of chronic stress on cognitive functions has been one of the hot topic in neuroscience. But there has been much controversy over its mechanism. Such single stressor applied in the past could not simulate complicated living circumstances that people confronted with. The aim of this study was to investigate the effects of chronic multiple-stress on learning and memory as well as on the levels of calcium/calmodulin-dependent protein kinase II (CaMKII), calmodulin (CaM) mRNA, and cAMP-response element binding protein (CREB) mRNA in the hippocampus of rats. METHODS: The rats were divided randomly into stressed and control groups. The stressed group was given chronic multiple-stress for 6 weeks to set up a chronic multiple-stressed model. The rats' performance of spatial learning and memory was tested using Morris Water Maze (MWM) and Y-maze. Meanwhile, the expressions of CaMKII, CaM mRNA and CREB mRNA of rats' hippocampus were detected by immunohistochemistry, Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. In addition, the width of synaptic cleft and the thickness of post-synaptic densities (PSD) were observed in the hippocampal CA3 region of rats by electron microscopy. RESULTS: After exposure to chronic multiple-stress for 6 weeks, the ability of learning and memory of the stressed group was higher than that of the control group (P < 0.05, P < 0.01). The width of synaptic cleft was smaller and the thickness of PSD was larger in the hippocampal CA3 region of the stressed group than in that of the control group (P < 0.01). The CaMK II immunostaining of the stressed group was stronger than that of the control group in the stratum radiatum and oriens of the hippocampal CA1 and CA3, especially in the stratum oriens. Quantitative analysis indicated that the expression of CaMK II, CaM mRNA, and CREB mRNA in the hippocampus of the stressed group was higher than that of the control group (P < 0.05, P < 0.01). CONCLUSIONS: The capacity of learning and memory can be enhanced after chronic multiple-stress. The increased levels of CaMK II, CaM mRNA, and CREB mRNA may contribute to the enhancing effect of chronic multiple-stress on learning and memory.

[Chronic multiple stress enhances learning and memory capability in rats].

The present study aimed at investigating the effects of chronic multiple stress on learning and memory functions of rats. Adult male Wistar rats were randomly divided into stressed and control groups. Rats in the stressed group were irregularly and alternately exposed to the situation of vertical revolution, sleep deprivation, noise stimulation, and night illumination 6 h per day for 6 weeks to prepare a chronic multiple stressed model. Learning and memory performance of rats was measured by using Morris water maze first and Y-maze afterwards. Neurons in the dentate gyrus(DG), CA3 and CA1 regions of the hippocampus were stained by using Cresyl violet method and counted. The results showed that: (1) After chronic multiple stress, compared with the control rats, the escape latency to the hidden platform in Morris water maze was significantly shortened in stressed rats. In stressed and control groups, the escape latency periods were (15.89+/-9.15) s and (27.30+/-12.51) s, respectively, indicating that spatial memory of the stressed rats was stronger than that of the control ones. In brightness-darkness discrimination learning in the Y- maze, the correct trials and correct percentage of entering safe arm was remarkably increased in the stressed rats, the correct rates of stressed and control groups were (79.01+/-1.23)% and (66.12+/-1.61)%, respectively, indicating that brightness-darkness discrimination learning ability of the stressed rats was better than that of the control ones. (2) After chronic multiple stress, nerve cell density in DG, CA1 and CA3 of the hippocampus in stressed rats was higher than that of the control group, the cell densities in DG, CA1 and CA3 of the stressed and the control group were (223.78+/-26.52), (112.07+/-14.23) and (105.55+/-18.12) as well as (199.13+/-15.36), (92.89+/-13.69), and (89.02+/-15.77) respectively. These results suggest that the chronic multiple stress may enhance the capability of spatial memory and brightness-darkness discrimination learning of rats. Possible reasons for the chronic multiple stress-induced learning and memory enhancement of rats were also discussed.