春丰50苦瓜的选育

以曼谷青皮、碧绿1号和钦州大肉苦瓜为育种材料,采用双父本混合花粉杂交和后代系谱选择育成优良自交系,再经配合力测定选出优良一代杂种春丰50。该品种生长势强,果实粗棒形,纵径26.3cm,横径6.45cm,皮色翠绿油亮,一般单果质量420g左右。平均每667m~2产量3 500kg。     

Relationship between the intracellular calcium concentration changes and left ventricular hypertrophy and function in the spontaneously hypertensive rats

AIM:To elucidate the relationship between the intracellular calcium concentration changes and left ventricular hypertrophy and function in the spontaneously hypertensive rats (SHR).METHODS:Intracellular free calcium concentrations were measured by Fura 2 methodology and left ventricular function quantitated by cardiac catheterization in 20 SHR aged 10, 22, and 34 weeks and 20 age-matched Wistar-kyoto (WKY) rats.RESULTS:(1) The systolic blood pressure(SBP), intracellular calcium concentrations and left ventricular mass / body weight index (LVM/BW) were significantly higher in all three age groups of SHR than the corresponding groups of WKY; (2) Compared with age-matched WKY groups, the peak left ventricular pressure descending rate(-dp／dt_max) decreased while left ventricular relaxation time constant (τ)increased significantly in SHR aged 22 and 34 weeks. The peak left ventricular pressure ascending rate(dp／dt_max) and the left ventricular contractility index were significantly increased only in the 34 weeks SHR; (3) Intracellular calcium concentrations showed a positive correlation with LVM/BW,SBP,-dp／dt_max and τ(r=0.47-0.83,P<0.01)and a negative correlation with dp／dt_max and the left ventricular contractility index (r=-0.46,P<0.05 and r=-0.81, P<0.01).CONCLUSION:Intracellular calcium overload is one of the potential mechanisms in the induction of left ventricular hypertrophy as well as of systolic and diastolic dysfunction.     

Role of p38MAPK in production of pro-inflammatory cytokines in Kupffer cells from severe acute pancreatitis rats

AIM:To investigate the role of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway in the Kupffer cells (KCs) production of pro-inflammatory cytokines, tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β), in severe acute pancreatitis (SAP) rats.METHODS:Sprague-Dwaley rats were randomized into three groups:①sham operation rats, ②SAP rats, ③SAP rats given the p38 MAPK inhibitor CNI-1493(10 mg/kg, iv). The SAP model was induced by the bili-pancreatic duct infusion with 5% sterile soduim taurocholate solution. Rats from each group were killed at 12 h after sham operation or SAP and Kupffer cells (KCs) were isolated. The mRNA expressions of TNF-α and IL-1β (by quantitative real-time RT-PCR) and p38 MAPK activity (by Western blot analysis) in KCs were examined. The levels of TNF-α and IL-1β in plasma were determined by ELISA.RESULTS:There was a significant acvitation of p38 MAPK in KCs harvested from SAP rats than those from sham operation rats. SAP also promoted the mRNA expressions of TNF-α and IL-1β in KCs and the plasma levels of TNF-α and IL-1β. These events were significantly inhibited by treatment with CNI-1493.CONCLUSIONS:p38 MAPK activation is one important aspect of the signaling events that may mediate the KCs production of pro-inflammatory cytokines, TNF-α and IL-1β, in SAP rats. The inhibition of the p38 MAPK may be a potential target in the prevention and treatment of SAP.     

Quick detection of sex determining region protein gene in mouse fetuses

AIM: To detect quickly the Y-chromosome specific sex determining region protein (Sry) gene in mouse fetuses on embryonic day 14.5 with a PCR method. METHODS: We designed specific primers with the OLIGO 5. 0 software. Templates were prepared in 30 minutes by the following way. About 1 mg embryonic tissue but not fetal liver was suspended, and treated with 200μL of lysis buffer, consisting of PCR buffer containing 20 mg/L proteinase K, 0. 5% NP-40, and 0.05% Tween 40, at 60°C for 15 minutes, heated for 5 minutes at 100 °C, 10μL was used as template. The PCR react ion was performed in 50μL, using two sets of primers specific for Sry gene (chromosome Y) and IL-3 gene (chromosome 11) . PCR conditions and cycle numbers were optimized. The assessment of the results was done by electrophoresis in 3% agarose run at high voltage. The specificity of the method was conf irmed by fluorescent in situ hybridization (FISH) using a specific male probe on embryonic tissue cells. RESULTS: Electrophoresis showed that PCR product of male control DNA consisted of a 649 bp product representing the IL-3 gene and a 444 bp product representing the Y-specific Sry gene, female control DNA only one 649 bp product. Fetuses with two bands matching those as seen inmale control DNA are the presumpt ive male fetuses. Fetuses, only the IL-3-associated 649 bp band, are the presumptive female fetuses. These were confirmed by FISH. The ent ire procedure took <3. 5 h. CONCLUSION: The established PCR assay offers a quick, simple, accurate, and sensitive detection of sex determining region protein gene in mouse fetuses. This method allowed the preparation and culture of pure male and female hematopoietic stem cells from fetal tissue.     

Sca-1+ cells from mouse fetal liver can differentiate into neurons in vitro

AIM: To study whether Sca-1⁺ cells from fetal liver can be induced to differentiate into neuronal cells in vitro. METHODS:Sca-1⁺cells from 14 5-days-old murine fetal liver were isolated with a magnetic cell sorting kit, and were cultured in Dulbecco s modif ied Eagle s medium(DMEM)/F12 supplemented with 10%fetal bovine serum(FBS), and passaged at a rat io of 1 3 when cells reached more than 80%confluence.The 5 passage cells were induced by 10^-3mol/Lβ-mercaptoethanol(β-ME)and 5×10^-7 mol/L all-trans-retinoic acid(RA)for 24 hours, and then incubated in serum-free medium for 5 hours to 5 days.The characteristics of treated cel s were assayed by immunocytochemistry staining analysis at 5 hours, or 5 days.RESULTS: Cells treated with β-ME and RA exhibited neuronal phenotype and expressed neuron-specific protein such as neuron-specific nuclear protein (NeuN), neuronfilament-M, and neuron-specific tubulin-1 (TuJ-1) but not tau, MAP-2, or the astrocyte-specific marker glial fibrillary acidic protein (GFAP).CONCLUSION: Sca-1⁺ cells from fetal liver, of which most are regarded as hematopoietic stem cells, could differentiate into early immature neuronal cells in vitro. These findings suggest that Sca-1⁺ cells from fetal liver may be an alternative source in cell therapy and gene therapy of neural dysfunction.     

Rat urotensin-II-induced main pulmonary artery contractions are mediated by MAPK

AIM: To investigate rat Urotensin-II(rat U-II)-induced vasoconstriction of rat main pulmonary arteries and the role of mitogen-activated protein kinase(MAPK). METHODS: The main pulmonary artery was dissected from the male Sprague-Dawley rats and artery ring width was 3-4 mm. Concentration-response curves were generated to rat U-II(0.03 nmol/L-30 nmol/L).Inhibitor of MAPK, PD 98059(0.1 μmol/L-10 μmol/L) were added into the medium after rat U-II(30 nmol/L)induced vasoconstriction had reached plateau to construct the relaxant concentration-response curves and their EC₅₀ and E_max. RESULTS：Rat U-II was a potent vasoconstrictor of isolated rat main pulmonary arteries [EC₅₀=7.95±0.40, E_max=(14.28±6.34)% of the response to 60 mmol/L KCl]; PD 98059 caused concentration-dependent relaxations of rat U-II precontracted arteries [EC₅₀=5.91±0.45, E_max=(81.39±13.65)%]. CONCLUSION: Rat U-II was a potent vasoconstrictor of rat main pulmonary arteries and this response was mediated through MAPK.     

The transdifferentiation of Sca-1+ cells from murine fetal liver

AIM:To explore transdifferentiation potential of Sca-1⁺ cells from murine fetal liver. METHODS:2×10³ of Sca-1⁺ cells from male murine fetal liver were transfused into female mouse irradiated lethally with γ ray from ⁶⁰ Co source (10 Gy) via tail vein. Two months later, FISH and immunohistochemistry were used to detect the situation for transdifferentiating of the donor cells (male cells) in tissues of female recipient mouse. RESULTS:The renal tubular epitheliocyte-like and neurocyte-like cells with Y chromosome were found on the sections of renal and brain tissues from female recipient mice. These cells have phenotype characteristics of RCA⁺/CD₄₅^-F_4/80^- and NueN⁺/CD₄₅^-F_4/80^-, respectively. CONCLUSION:The evidence is provided for Sca-1⁺ cells from murine fetal liver to transdifferentiate into both renal and brain tissue cells.     

Therapeutic effects of recombinant human growth hormone on rat sepsis

AIM:To investigate therapeutic effects of recombinant human growth hormone(rhGH) on rat sepsis and its possible mechanisms.METHODS:Mean arterial pressure (MAP), levels of plasma TNFα, IL-1β and endotoxin, leukocyte count and survival rate within 1 week were determined after E. coli injection among control group, sepsis group and sepsis+rhGH group.RESULTS:(1)rhGH diminished the decrease of MAP, reduced plasma endotoxin and TNFα levels and increased neutrophil ratio in total leukocytes in sepsis rat. rhGH increased survival rate within 1 week on sepsis rat. (2)No changes were found in IL-1β level among the three groups.CONCLUSION:rhGH showed desirable beneficial effects on rat sepsis, which may attribute to: improving circulatory function;maintaining intestinal mucosa barrier, attenuating bacteria/endotoxin translocation and inhibiting the production and release of TNFα.     

Serum contents of E-selectin,sICAM-1, sVCAM-1 in patients with acute coronary syndrome

AIM:To explore the serum levels of certain adhesion molecules and its significance in acute coronary syndrome(ACS). METHODS:The subjects included 40 patients with acute myocardial infarction(AMI) and 40 patients with unstable angina pectoris (UAP). Among the 80 patients, 60 patients accepted a follow-up 4 months. At the same time we selected 40 controls from people who attended a routine health check in the university. Serum levels of E-selectin, sICAM-1, sVCAM-1 were measured by ELISA.RESULTS:Serum levels of E-selectin, sICAM-1, sVCAM-1 were significantly higher in the ACS group(AMI or UAP) than in the control group. Four months later, the levels of E-selectin, sICAM-1 became significantly lower in the follow-up group than in the ACS group, while sVCAM-1 showed no significant difference. CONCLUSION:Serum levels of E-selectin, sICAM-1 may have certain diagnostic value for ACS, and can be a useful marker reflecting the stability of the disease.