AIMTo investigate the protective effects and mechanism of action of aspirin on focal cerebral ischemia-reperfusion rats.

METHODSThe right middle cerebral artery of the rat was occluded by inserting a thread through internal carotid artery for 2 h, and then reperfused for 24 h. Different doses of aspirin were intragastricly administrated at reperfusion 0 h and 6 h. The injured area of the brain and cerebral edema were estimated. The contents of prostacyclin (PGI2), thromboxane (TXA2), and endothelin (ET) in plasma were measured by 125I radioimmunoassay method. The content of nitric oxide (NO) in plasma was measured by the nitrate reductase method. The malondialdehyde (MDA) content in brain tissue was determined by the thiobarbituric acid method. The superoxide dismutase content (SOD) in brain tissue was assayed by the xanthine oxidase method. The content of adenosin 5'-triphosphate (ATP) in brain tissue was separated by capillary electrophoresis.

RESULTSThe injured area of the brain and the cerebral edema of occluded side were dramatically reduced after 6 and 60 mg.kg-1 doses of aspirin were administrated intragastricaly. The ratio of PGI2/TXA2 in plasma was increased by aspirin in a dose-dependent manner. In brain tissue of the occluded side, the MDA content was reduced from 9.0 +/- 0.75 to 6.48 +/- 0.74, and the ATP level was increased from 10.26 +/- 1.02 to 25.65 +/- 3.45 by the 60 mg.kg-1 dose of aspirin. No significant effect on SOD content was observed. In plasma, the NO content was significantly decreased from 24.76 +/- 1.88 to 8.17 +/- 0.79, and the ET level was increased from 254.85 +/- 21.14 to 278.43 +/- 16.79 by 6 mg.kg-1 dose of aspirin.

CONCLUSIONThe neuroprotective effects of aspirin on focal cerebral ischemia-reperfusion rats might be attributed to its effects by increasing the ratio of PGI2 and TXA2, reducing lipid peroxides and improving the energy metabolism.

Animals ; Aspirin ; administration & dosage ; therapeutic use ; Brain Ischemia ; blood ; complications ; metabolism ; Disease Models, Animal ; Epoprostenol ; blood ; Male ; Malondialdehyde ; metabolism ; Neuroprotective Agents ; therapeutic use ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; etiology ; pathology ; prevention & control ; Superoxide Dismutase ; metabolism ; Thromboxane A2 ; blood

OBJECTIVETo investigate the effects of benzo[a]pyrene (B[a]P) exposure on the behaviors and hippocampal oxidative stress and ATPase in rats and the molecular mechanism of neurobehavioral toxicity of B[a]P.

METHODSA total of 120 male SD rats (21 days old) were randomly and equally assigned to five groups: blank control group, vegetable oil (solvent control) group, and 2.5, 5, and 10 mg/kg B[a]P exposure groups. The rats in B[a]P exposure groups were injected intraperitoneally with B[a]P once a day for 4 consecutive weeks. Then, Morris water maze and shuttle box were used to evaluate the learning and memory abilities of rats; colorimetric assay was used to measure the activities of superoxide dismutase (SOD), Na(+)/K(+)-ATPase, and Ca(2+)/Mg(2+)-ATPase and the content of malonaldehyde (MDA) in the hippocampus; the concentration of Ca(2+) in the hippocampus was measured by fluorescent labeling.

RESULTSCompared with the blank control group and solvent control group, the B[a]P exposure groups exhibited significant increases in escape latency, active avoidance response latency, and passive avoidance response latency and significant decreases in number of platform crossings and active avoidance response frequency in the last test (P < 0.05 for all comparisons), with a dose-effect relationship. In addition, the B[a]P exposure groups had significantly lower activities of SOD, Na(+)/K(+)-AT-Pase, and Ca(2+)/Mg(2+)-ATPase and significantly higher MDA level and Ca(2+) concentration than the blank control group and solvent control group (P < 0.05 for all comparisons), with a dose-effect relationship.

CONCLUSIONThe neurobehavioral toxicity of B[a]P may be related to increased oxidative stress and decreased activities of Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase in the hippocampus of rats.

Animals ; Benzo(a)pyrene ; toxicity ; Ca(2+) Mg(2+)-ATPase ; metabolism ; Hippocampus ; drug effects ; metabolism ; Male ; Oxidative Stress ; drug effects ; Rats ; Rats, Sprague-Dawley ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Superoxide Dismutase ; metabolism

OBJECTIVETo investigate the effects of preweaning enrichment on the expression of activity-regulated cytoskeletal protein (Arc), an immediate early gene, and on the long-term memory in rats.

METHODSForty neonatal Sprague-Dawley rats were randomly assigned to control group (standard environment, n=20) and experimental group (enriched environment, n=20). The experimental group received enriched environment exposure from postnatal day 10 until weaning (2 weeks, 20 minutes per day). The open field and novel object recognition tests were performed at postnatal day 28. Arc expression was detected by Western blotting and immunohistochemistry.

RESULTSThere was no significant difference in the open field test between the two groups. However, in the novel object recognition test, the experimental group rats performed significantly better than the control rats after 1 and 24-hr retention. The preference index in the experimental group after 1-hr (59.61%+/-9.61% vs 50.46%+/-9.34%; P<0.05) and 24-hr retention (62.72%+/-14.12% vs 52.39%+/-9.16%; P<0.05 ) was significantly higher than that in the control group. Arc expression in both areas CA1 and DG of hippocampus in the experimental group increased significantly compared with that in the control group (P<0.01).

CONCLUSIONSPreweaning enrichment can up-regulate the expression of immediate early gene, Arc, in the hippocampus of the rats, and promote their long-term memory.

Animals ; Cytoskeletal Proteins ; analysis ; Female ; Hippocampus ; chemistry ; physiology ; Immunohistochemistry ; Male ; Memory ; Nerve Tissue Proteins ; analysis ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the protective effects of irbesartan against cardiac inflammation associated with diabetes and obesity in the db/db mouse model of type 2 diabetes and explore the underlying mechanisms.

METHODSTwenty- four 10-week-old diabetic db/db mice were equally randomized into irbesartan treatment (50 mg/kg per day) group and model group, using 12 nondiabetic littermates (db/+) as the controls, The mice were treated with irbesartan or saline vehicle for 16 consecutive weeks, after which the heart pathology was observed and the heart weight, body weight, and serum levels of fasting blood glucose (FBG), total cholesterol(TC), and triglycerides(TG) were measured. The expression of nuclear factor-kappaB (NF-κB) p65 in the myocardium was assessed with immunohistochemistry, the protein levels of P-IκBα ,IκBα and β-actin were analyzed with Western blotting, and the pro-inflammatory cytokines IL-6 and TNF-α mRNA were detected using quantitative real-time PCR (qPCR).

RESULTSCompared with db/+ mice, the saline-treated db/db mice developed obesity, hyperglycemia and hyperlipidemia (P<0.01). Histopathological examination of the heart tissue revealed inflammatory cell infiltration, increased myocardial interstitium and disorders of myocardial fiber arrangement. The diabetic mice showed increased P-IαBα and decreased IκBα protein levels, enhanced activity and expression of NF-κB in the hearts, and increased mRNA expression of IL-6 and TNF-α in the myocardium. These abnormalities were all associated with increased inflammatory response. Treatment with irbesartan improved the heart architecture and attenuated high glucose-induced inflammation in the diabetic mice.

CONCLUSIONTreatment with irbesartan attenuates cardiac inflammation in type 2 diabetic db/db mice, and this effect was probably associated with the suppression of cardiac angiotensin II and NF-κB signaling pathway.

Actins ; metabolism ; Angiotensin II ; metabolism ; Animals ; Biphenyl Compounds ; pharmacology ; Cardiovascular Diseases ; drug therapy ; Diabetes Mellitus, Experimental ; complications ; Diabetes Mellitus, Type 2 ; complications ; Inflammation ; drug therapy ; Interleukin-6 ; metabolism ; Mice ; Obesity ; complications ; Random Allocation ; Real-Time Polymerase Chain Reaction ; Signal Transduction ; Tetrazoles ; pharmacology ; Transcription Factor RelA ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo investigate the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates from Chinese children in seven cities.

METHODA total of 134 MRSA isolates were collected from nine hospitals. Multilocus sequence typing and spa typing were analyzed by polymerase chain reaction (PCR), and staphylococcal chromosomal cassette mec (SCCmec) type was analyzed by multiplex PCR. The Panton-Valentine leukocidin (pvl) gene was also detected.

RESULTMost MRSA strains were isolated from pneumonia and skin and soft tissue infection (SSTIs) patients, accounting for 82.1%. Overall, 16 sequence types (STs) were obtained, and CC59 (51.7%) was found to be the most prevalent, which included ST 59 and ST 338, followed by ST239 (16.4%). SCCmec types II, III, IV, and V were also identified in the current study. SCCmec type IV was the most predominant type at 50.0%, followed by SCCmec type V at 23.9% and III at 23.9%. SCCmec subtypes IVa, IVc, and IVg were found among SCCmec type IV strains, whereas IVa was the main subtype at 77.6%. Twenty-six spa types were also identified, among which the predominant type was t437 (47.8%). The prevalence of pvl genes and the SCCmec type of strain was relevant, and the pvl gene positive rate was higher in SCCmec type IV and V-type strains than in SCCmec type II and III strains (58.6% vs. 14.3%, P < 0.05); there was a significant difference between them. In the strains isolated from pneumonia and SSTIs, ST59-MRSA-IVa(t437) was the predominant clone. There were five clones detected from the strains isolated from septicemia, with ST59-MRSA-IVa(t437) and ST59-MRSA-V(t437) as the main clones (57.1%). Various predominant clones existed in different regions. ST59-MRSA-IVa(t437) was the prevalent clone in the Guangzhou, Beijing, Chongqing, and Shenzhen areas, whereas ST239-MRSA-III(t037) was the prevalent clone in the Shanghai area. Fifty percent of the isolates from the Wenzhou area belonged to ST910-MRSA-V(t318), whereas three clinical strains isolated from the Shenyang region belonged to three different types.

CONCLUSIONThe results indicate that MRSA isolates from Chinese children are largely associated with the ST59-MRSA-IV(t437) and ST239-MRSA-III(t037) clones. These two may belong to community-acquired MRSA and hospital-acquired ones, respectively. Different prevalent clones were detected in different diseases and different regions. Therefore, there is a need to conduct further research on clinical isolates, which can guide the choice of antibiotic treatment and the examination of MRSA prevalence.

Adolescent ; Bacterial Typing Techniques ; Child ; Child, Preschool ; China ; epidemiology ; DNA, Bacterial ; genetics ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Methicillin-Resistant Staphylococcus aureus ; classification ; genetics ; isolation & purification ; Prevalence ; Staphylococcal Infections ; epidemiology ; microbiology

OBJECTIVETo investigate the expression of N-cadherin in bone marrow leukemic cells derived from acute leukemia patients and its clinical significances.

METHODSA total of 113 patients with acute leukemia were enrolled in this study. Flow cytometry was employed to detect the expression of N-Cadherin in bone marrow leukemic cells from acute leukemia patients and the relationships between the N-cadherin expression and the clinical characteristics of patients with acute leukemia were analyzed.

RESULTSThe expression of N-Cadherin in bone marrow leukemic cells deriveted from patients with acute leukemia was variable with 0%-99.7%. For adult AML patients, the positive rate of CD34 in N-cadheringroup was significantly higher than that in N-cadheringroup(67.39% vs 33.33%)(P=0.013), while the differences of total CR rate and rate of CR after 1 cycle of induction treatment were not significant between these 2 groups(P>0.05). As to ALL patients, N-cadheringroup had significant lower WBC count (21.31±7.07 vs 51.10±23.69)(P=0.008) and lower percentage of peripheral blood blast (43.22±5.75% vs 66.45±5.65%)(P=0.015). The CR rate after 1 cycle of induction treatment and rate of overall CR were lower and the relapse rate was higher in N-cadherinALL group than those in N-cadherinALL group, but the differences were not significant (P>0.05). For childhood ALL, the positive rate of CD33 in N-cadheringroup was significantly higher than that in N-cadheringroup(47.62% vs 0%)(P=0.012). The relapse rate was higher in N-cadheringroup than that in N-cadheringroup (30.00% vs 0%)(P=0.115). The median survival time, 3-year overall OS rate and 3-year relapse-free survival rate in N-cadheringroups of adult AML, non-M3 AML, ALL and chidhood ALL paients were superior to N-cadheringroups, but the differences were not significant.

CONCLUSIONThe expression of N-cadherin in bone marrow leukemic cells relates to some clinical features of patients with acute leukemia and to some extent has inferior effect on survival of patients with acute leukemia.