Objectives To establish a model of carotid atherosclerotic (AS)stenosis in rabbits and to preliminarily investigate the expression of asparaginyl endopeptidase. Methods Fourteen New Zealand white rabbits were divided into either an model group (n = 8)or a sham operation group (n = 6)according to the random number table. The carotid intima was injured by operation in the model group. The rabbits in both groups were fed with high fat diets containing magnesium for 10 weeks. The rabbits were weighted and their blood lipids were tested every 2 weeks. At the end of the fifth and tenth weeks after procedure,the plaque and vessel stenosis of the rabbits were observed by MRI. At the end of the tenth week after proce-dure,the specimens were collected and sliced. Hematoxylin and eosin (HE)staining was used to observe the pathological changes. Immunohistochemical staining was used to analyze the expression of asparaginyl endopeptidase (AEP). Results One rabbit in the model group died of carotid artery injury. After being fed with high-fat diets,the body quality and the level of blood lipid were increased in the rabbits of both groups compared with those before procedure (all P < 0. 01). At the end of the fifth and tenth weeks after procedure,MRI revealed that the luminal stenosis rates in the operation group were 16 ± 11% and 53 ± 20% respectively. There was significant difference within the group (t = - 4. 83,P < 0. 01). MRI revealed no luminal stenosis twice in the sham operation group. HE staining showed intimal hyperplasia,AS plaque formation,lipid deposition in plaques,macrophage and smooth muscle cells migration and infiltration forming foam cells in the model group. No AS formation was observed in the sham operation group. The expression of AEP was higher in the rabbit carotid artery tissue in the model group,and it expressed rarely in the sham surgery group. The absorbance values were 0. 072 0 ± 0. 028 0 and 0. 002 0 ± 0. 000 9 respectively. There was significant difference (t = 6. 61,P < 0. 01). Conclusions The methods of injuring carotid intima combined with magnesium containing high-fat diet may exactly,reliably,and quickly establish an AS carotid artery stenosis model. AEP may associat with the occurrence of AS plaques.

Objective To evaluate the clinical outcome of external bracket fixation in the treat- ment of complex tibia diaphysis fracture involving intra-articular fractures.Methods Forty-two cases of complex tibia diaphysis fracture with proximal and distal intra-articular fractures treated surgically in our hospital from January 1999 to January 2004 were analyzed.The complex tibia diaphysis fractures were categorized according to the AO classification as type C2 (multiple segments fracture) and type C3 (ir- regular fracture),proximal and distal intra-articular fractures in 23 and 19 cases,respectively.Definite operation was done within one week.Twenty-two cases were treated with simple external fixator,and 20 cases treated with screws and external fixator.Results All the 42 cases were followed-up regularly. According to AO evaluation of the knee and ankle joint movement,83% (35/42 cases) of the cases gained satisfactory functional outcome,14% (6/42 cases) had quite satisfactory results and 2% (1/42 case) had unsatisfactory functional outcome.Conclusion External bracket fixation can obtain outcome of relative length of the tibia and fibula,tube structure reconstruction,smoothness of the articular surface and the parallel and symmetric relation of knees and ankles for complex tibia diaphysis fracture with proxi- mal and distal intra-articular fracture.The arthritis resulting in pain in movement and restriction of func- tion is considered to be the most important factor affecting the joint function.Early functional exercise is important for best recovery of knee and ankle function.

The DNA fragment sized 2 139bp, the same Sequence with AtKup1 gene from Arabidopsis thalianna was used as the templates for DNA family shuffling. The shuffeld AtKup1 gene library was expressed in the mutant of 5. cerevisae in which potassium transporter gene TRK1 and TRK2 were knocked out by homologous recombination. Then the screening was carried out in the low potassium media containing 5. 0 mmol/L KC1 and no histidine in it. it was found that both of diverse and wild AtKup1 gene can rescues the trk1△trk2△yeast mutant strain in low [ K + ] medium. The growth of 2 clones yeast containing diverse AtKup1 were beter than that of AtKup1 wild gene transformant. The sequencig results of the shuffeld AtKup1 showed that there were 2 nucleotide changed, which resulted in 2 amino acid variations in it compared with the original AtKup1. The potassium uptaking capacity of shuffled AtKup1 gene increased significantly when it was transformed into tobacco.

Depression is a serious mental illness with a high incidence. At present, we do not fully understand the specific pathological mechanisms of depression, and the efficacy of drug treatments is very limited. Recent studies have shown that epigenetic changes that occur in specific brain regions may be a key mechanism by which environmental factors to interact with individuals to influence the risk of depression. Therefore, drugs that target epigenetic regulation may become a new direction for the development of antidepressants. Histone deacetylase inhibitors (HDACi) are a class of compounds that inhibit histone deacetylase activity, which has been reported to be associated with depression; this article addresses the use of HDACi in preclinical studies, and their potential therapeutic role and limitations of use in depression.

OBJECTIVETo establish determination method of formic acid, lactic acid, acetic acid and succinic acid in dental plaque with high performance liquid chromatography (HPLC).

METHODSAfter the samples were centrifuged, 2 microL supernatant was transferred to a 1 mL centrifuge tube and diluted in water, then was determined with HPLC. The mixture of phosphate buffer and methanol (97:3) as mobile phase throughout the experiment. The determination of organic acid was performed on Phenomenex C18 column and at their maximum absorption wave.

RESULTSThe linear ranges of formic acid, lactic acid, acetic acid and succinic acid were 0.110-500, 0.049-500, 0.047-500, 0.084-500 microg/mL. The detection limits were 0.110, 0.049, 0.047, 0.084 microg/mL. The relative standard derivation were 9.5%, 7.9%, 4.3%, 4.2%. The average recoveries of samples were 82%-112%, 82%-102.5%, 90%-115%, 80%-110%.

CONCLUSIONThe method was simple, quick and adapt for analysis of organic acid in dental plaque.

Chromatography, High Pressure Liquid ; Dental Plaque ; Formates

BACKGROUNDPulmonary embolism (PE) is rare and seldom considered in adolescent patients; however it occurs with a greater frequency than is generally recognized, and it is a potentially fatal condition. The aim of the current study was to understand its epidemiology, clinical features and the cause of delay of its diagnosis in adolescents.

METHODSA retrospective analysis of nine adolescents with acute PE admitted to the Peking University Third Hospital over the past 16-year period was performed. The epidemiology, clinical features and risk factors of the adolescents were described and compared with those of adults and elderly patients. The time to diagnosis and misdiagnosed diseases were analyzed. Pretest probability of PE was assessed retrospectively by the Wells score and revised Geneva score.

RESULTSThe incidence of PE was 43.6 per 100 000 hospitalized adolescents in our hospital. The incidence of PE in adolescents was much lower than that in adults and PE is diagnosed in about 1/50 of elderly people. The clinical features in adolescents were similar to those in adults. But fever and chest pain were more common in adolescents (P < 0.05). The major risk factors included surgery, systemic lupus erythematosus (SLE), thrombocytopenia, long-term oral glucocorticoids and trauma. The mean diagnostic time was (7.8 ± 8.4) days. Six cases had a delayed diagnosis. The mean delay time from symptom onset to diagnosis was (11.0 ± 8.8) days. The time of presentation to diagnosis in patients initially admitted to the emergency department was less than one day, and was much shorter than the time in outpatients, (9.4 ± 7.5) days. Most of the patients were initially misdiagnosed with a respiratory tract infection. Most patients' values of Wells score or revised Geneva score were in the moderate or high clinical probability categories; 88% by Well score vs. 100% by revised Geneva score.

CONCLUSIONSPE was seldom considered in the adolescent patients by physicians, especially outpatient physicians, so the diagnosis was often delayed. If adolescent patients complain of dyspnea or chest pain or syncope with/without fever, and they had risk factors such as surgery, thrombocytopenia and trauma, PE should be considered and included in the differential diagnosis.

Adolescent ; Adult ; Diagnosis, Differential ; Diagnostic Errors ; Humans ; Male ; Probability ; Pulmonary Embolism ; diagnosis ; epidemiology ; etiology ; Retrospective Studies ; Risk Factors

OBJECTIVETo investigate the effect of interleukin-2 (IL-2) on myocardial impairment during ischemia/reperfusion or anoxia/reoxygenation.

METHODSChemical anoxia was introduced in the isolated rat ventricular myocytes by Krebs-Henseleit (K-H) solution containing 10(-3) mol/L sodium dithionite. The video-tracking system and spectrofluorometric method were employed to verify the cell contraction and calcium homeostasis of the single myocyte. Radioimmunoassay was used to analyze the IL-2 levels in myocardium.

RESULTSThe levels of IL-2 in myocardium subjected to ischemia/reperfusion were elevated [(14.34+/-5.99 compared with 22.25+/-3.68)ng/g, P<0.01]. During anoxia, cell contraction and the amplitude of electrically induced calcium transient were depressed and the parameters did not return to the pre-anoxia level during reoxygenation. IL-2 at 200 U/L administered during anoxia aggravated the effect of reoxygenation on cell contraction and calcium transient. After perfusion with IL-2, the malondialdehyde content of myocardial mitochondria was elevated.

CONCLUSIONCoexistence of IL-2 during anoxia aggravates the effect of reoxygenation on the cell contraction and calcium homeostasis in the isolated rat ventricular myocytes, in which the mitochondrial lipid peroxidation induced by IL-2 is involved.

Animals ; Calcium ; metabolism ; Interleukin-2 ; physiology ; Lipid Peroxidation ; Male ; Malondialdehyde ; blood ; Mitochondria, Heart ; metabolism ; Myocardial Ischemia ; physiopathology ; Myocardial Reperfusion Injury ; physiopathology ; Rats ; Rats, Sprague-Dawley

BACKGROUNDHuman urotensin II (UII) is the most potent mammalian vasoconstrictor identified so far. Our previous study showed that UII is a potent mitogen of airway smooth muscle cells (ASMC) inducing ASMC proliferation in a dose-dependent manner. The signal transduction pathway of UII mitogenic effect remains to be clarified. This study was conducted to investigate the signal transduction pathway in the proliferation of ASMC induced by UII.

METHODSIn primary cultures of rat ASMCs, activities of protein kinase C (PKC), mitogen-activated protein kinase (MAPK) and calcineurin (CaN) induced by UII were measured. The effect of CaN on PKC and MAPK was studied by adding cyclosporin A (CsA), a specific inhibitor of CaN. Using H7 and PD98059, inhibitors of PKC and MAPK, respectively, to study the effect of PKC and MAPK on CaN. The cytosolic free calcium concentration induced by UII was measured using Fura-2/AM.

RESULTSUII 10(-7) mol/L stimulated ASMC PKC and MAPK activities by 44% and 24% (P < 0.01), respectively, after incubating for 20 minutes. It increased CaN activity in a time-dependent manner, being 1.68 times as that of control for 24 hours (P < 0.01). It promoted the cytosolic free calcium concentration increase of 18% (P < 0.01). CsA 10(-6) mol/L and H7 50 micromol/L inhibited UII-stimulated CaN activity by 45% (P < 0.01) and 21% (P < 0.05), respectively, while PD98059 50 micromol/L had no effect on CaN activity (P > 0.05). CsA 10(-6) mol/L inhibited UII-stimulated PKC activity by 14% (P < 0.05), while having no effect on MAPK activity (P > 0.05).

CONCLUSIONSUII increases cytosolic free calcium concentration and activates PKC, MAPK and CaN. The signal transduction pathway between PKC and CaN has cross-talk.

Animals ; Calcineurin ; metabolism ; Cells, Cultured ; Enzyme Activation ; Mitogen-Activated Protein Kinases ; metabolism ; Mitogens ; pharmacology ; Myocytes, Smooth Muscle ; cytology ; Protein Kinase C ; metabolism ; Rats ; Signal Transduction ; physiology ; Trachea ; cytology ; Urotensins ; pharmacology

The major idea of this article is to discuss standardization and normalization for the product standard of medical devices. Analyze the problem related to the physical performance requirements and test methods during product standard drafting process and make corresponding suggestions.
Device Approval ; Equipment and Supplies ; standards ; Materials Testing ; methods ; Weights and Measures

OBJECTIVETo investigate the clinical significance of anaphylatoxin C3a in induced sputum in patients with asthma.

METHODSThe patients with acute exacerbation of asthma treated at our department between September, 2006 and February, 2007 were included in the study. The demographic data, medical history, levels of lung function and C3a levels in induced sputum were assessed.

RESULTSA total of 33 patients were included in the study. The level of C3a in induced sputum was significantly higher in patients with acute exacerbation of asthma (2.24 ng/ml, range 1.68-5.58 ng/ml) than that in patients with asthma remission (0.7 ng/ml, range 0.24-2.31 ng/ml, P<0.05). Sputum C3a levels in the remission patients were significantly higher than those in the healthy controls (0.12 ng/ml, range 0.07-0.39 ng/ml, P<0.05). The levels of C3a in patients with severe exacerbation (4.69 ng/ml, range 2.69-6.59 ng/ml) were significantly higher than those in patients with mild exacerbation (0.25 ng/ml, range 0.09-0.40 ng/ml) and moderate exacerbation (2.21 ng/ml, range 1.16-3.41 ng/ml) (P<0.01), and were significantly higher in patients with moderate exacerbation than in those in mild exacerbation (P<0.01). The level of C3a in induced sputum was positively correlated with the number of total cell count (r=0.718, P<0.05), eosinophils (r=0.495, P<0.05) and macrophages (r=0.600, P<0.05) in patients with acute exacerbation of asthma.

CONCLUSIONInduced sputum C3a level can serve as an important clinical biomarker for clinical asthma management.

Asthma ; physiopathology ; Biomarkers ; chemistry ; Case-Control Studies ; Complement C3a ; chemistry ; Eosinophils ; Humans ; Leukocyte Count ; Macrophages ; Sputum ; chemistry