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B Levels (b + level)
Selected AbstractsDetermination of a novel diarylheptanoid (Juglanin B) from green walnut husks (Juglans regia L.) in rat plasma by high-performance liquid chromatographyBIOMEDICAL CHROMATOGRAPHY, Issue 3 2010Xin-Yi Huang Abstract A simple and reliable analytical method based on high-performance liquid chromatography (HPLC) coupled with a diode array detector (DAD) was developed for the determination of a novel diarylheptanoid (Juglanin B) from green walnut husks (Juglans regia L.) in rat plasma using rhoiptelol as an internal standard. Chromatographic separation was carried out on a Sinochrom ODS-AP C18 column (250 × 4.6 ,m i.d., 5 mm) with acetonitrile,10 mM postassium dihydrogen phosphate (pH = 3; 55:45, v/v) as mobile phase, and the detection wavelength was set at 214 nm. The plasma samples were prepared using methanol as protein precipitator. The extraction recovery of Juglanin B ranged from 70.26 to 78.59%, and the calibration curve had a good linearity in the range 0.08,50 ,g/mL (r2 = 0.9932). The RSDs of intra- and inter-day precision ranged from 1.19 to 4.92% and 4.35 to 4.54%, respectively. The HPLC-DAD method described is a simple, rapid and reliable method for the determination of Juglanin B level and for use in studies involving pharmacokinetics. Copyright © 2009 John Wiley & Sons, Ltd. [source] Inhibition of tyrosine kinase receptor type B synthesis blocks axogenic effect of estradiol on rat hypothalamic neurones in vitroEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2004V. I. Brito Abstract 17-,-estradiol (E2) increases axonal growth and tyrosine kinase receptor (Trk)B levels of male-derived hypothalamic neurones in vitro. To investigate whether the axogenic response depends on the upregulation of TrkB, we analysed neuritic growth and neuronal polarization in cultures treated with an antisense oligonucleotide against TrkB mRNA. In cultures without E2, treatment with 7.5 or 10 µm antisense reduced TrkB levels and the percentage of neurones showing an identifiable axon; the number and length of minor processes were increased. In cultures treated with 5 µm antisense, morphometric parameters were normal although total TrkB levels were reduced. The same dose prevented the E2-dependent increase of TrkB levels and suppressed the axogenic effect of E2. These results indicate that TrkB is necessary for normal neuronal growth and maturation and further suggest that an increase in TrkB is necessary for E2 to exert its axogenic effect in male-derived neurones. [source] The ,-tubulin complex protein Alp4 provides a link between the metaphase checkpoint and cytokinesis in fission yeastGENES TO CELLS, Issue 4 2002Leah Vardy Background:, The progression of cytokinesis requires cyclin B destruction by the anaphase promoting complex (APC/C) and, in fission yeast, activation of the septation initiation network (SIN) is also essential. The ,-tubulin complex (,-TuC) localizes to the centrosome throughout the cell cycle and is directly involved in the organization of the mitotic spindle. Results:, We have previously shown that the mutant defective in alp4+ (Spc97/GCP2) displays bipolar spindle defects due to a failure in the recruitment of the ,-TuC on to the spindle pole body (SPB, the centrosome equivalent). Here we show that in these mutants the Mad2 checkpoint is activated, yet septation proceeds due to the untimely activation of the SIN. The Sid1 kinase, the downstream effector of the SIN, is recruited prematurely to both, instead of only one, of the SPBs, which triggers septation despite the presence of monopolar spindles. Remarkably, cyclin B levels, which would normally have declined, remain high at the SPB in septated mutant cells. Conclusions:, We propose a novel role of the ,-TuC in inhibiting activation of the SIN until cyclin B is destroyed. Given the ubiquitous existence of the ,-TuC, this mechanism may be conserved throughout evolution and function to couple cytokinesis to mitotic exit. [source] Inhibition of CK2 Activity by TGF-,1 Promotes I,B-, Protein Stabilization and Apoptosis of Immortalized HepatocytesHEPATOLOGY, Issue 6 2003Lakita G. Cavin Nuclear factor ,B (NF-,B) is an antiapoptotic factor involved in development, regeneration, and neoplastic progression of the liver. Previously, we have shown that stabilization of inhibitor ,B (I,B)-, protein following treatment of hepatocytes with transforming growth factor (TGF)-,1 promoted NF-,B repression, which then permitted induction of AP-1/SMAD-mediated liver cell death. Because basal I,B-, protein turnover is regulated by protein kinase CK2, here we have elucidated the regulation of CK2 kinase activity and its role in control of NF-,B levels following treatment with TGF-,1. We show that both messenger RNA (mRNA) and protein levels of the CK2, catalytic subunit are down-regulated following TGF-,1 stimulation in murine hepatocyte cells. The ensuing inhibition of CK2 kinase activity promotes stabilization of I,B protein, which is followed by the shutoff of constitutive NF-,B activity and induction of apoptosis. Ectopic expression of CK2, inhibits TGF-,1-induced apoptosis through sustained activation of NF-,B. Conversely, expression of a kinase-dead mutant of CK2, potentiates TGF-,1 cell killing. Importantly, we show that hepatocellular carcinomas (HCCs) derived from TGF-,1 transgenic mice and human HCC cell lines display enhanced CK2 I,B kinase activity that contributes in part to an elevated NF-,B activity in vivo. In conclusion, inhibition of CK2 expression levels by TGF-,1 is crucial for the induction of apoptosis of hepatocytes. Circumvention of this process by up-regulation of CK2 activity in transformed cells may contribute to the promotion of TGF-,1-induced liver carcinogenesis. [source] Gonadal dysfunction in male cancer patients before cytotoxic treatmentINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2010Niels J. Van Casteren Summary Male patients diagnosed with cancer are often referred for semen cryopreservation before gonadotoxic treatment but often have low semen quality. The aim of this study was to evaluate which type of cancer affects gonadal function and proposes a risk factor for low pre-treatment semen quality. Between January 1983 and August 2006, 764 male cancer patients were referred for semen cryopreservation prior to chemotherapy and radiotherapy. We compared semen characteristics and reproductive hormones between different groups of cancer patients. In addition, we evaluated the role of tumour markers in patients with testicular germ-cell tumours (TGCT) on fertility. Abnormal semen parameters were found in 489 men (64%) before cancer treatment. Patients with TGCT and extragonadal germ-cell tumours had significantly lower sperm concentrations and inhibin B levels than all other patient groups. No semen could be banked in 93 patients (12.2%). Eight hundred and thirty-nine of 927 (90%) produced semen samples were adequate for cryopreservation. Inhibin B in all groups showed to be the best predictor of semen quality. Although pre-treatment raised tumour markers were associated with a decrease in inhibin B and increased follicle stimulating hormone, both predictive for low semen quality; no direct linear association could be found between raised beta-HCG, alfa-fetoprotein and semen quality. Only 1/3 of cancer patients had normal semen parameters prior to cancer treatment. Patients with TGCT and extragonadal GCT have the highest risk for impaired semen quality and gonadal dysfunction at the time of semen cryopreservation. [source] Dietary-feeding of grape seed extract prevents azoxymethane-induced colonic aberrant crypt foci formation in fischer 344 ratsMOLECULAR CARCINOGENESIS, Issue 7 2010Balaiya Velmurugan Abstract Chemoprevention by dietary agents/supplements has emerged as a novel approach to control various malignancies, including colorectal cancer (CRC). This study assessed dietary grape seed extract (GSE) effectiveness in preventing azoxymethane (AOM)-induced aberrant crypt foci (ACF) formation and associated mechanisms in Fischer 344 rats. Six-week-old rats were injected with AOM, and fed control diet or the one supplemented with 0.25% or 0.5% (w/w) GSE in pre- and post-AOM or only post-AOM experimental protocols. At 16,wk of age, rats were sacrificed and colons were evaluated for ACF formation followed by cell proliferation, apoptosis, and molecular analyses by immunohistochemistry. GSE-feeding caused strong chemopreventive efficacy against AOM-induced ACF formation in terms of up to 60% (P,<,0.001) reduction in number of ACF and 66% (P,<,0.001) reduction in crypt multiplicity. Mechanistic studies showed that GSE-feeding inhibited AOM-induced cell proliferation but enhanced apoptosis in colon including ACF, together with a strong decrease in cyclin D1, COX-2, iNOS, and survivin levels. Additional studies showed that GSE-feeding also decreased AOM-caused increase in ,-catenin and NF-,B levels in colon tissues. Compared to control animals, GSE alone treatment did not show any considerable change in these biological and molecular events in colon, and was nontoxic. Together, these findings show the chemopreventive efficacy of GSE against the early steps of colon carcinogenesis in rats via likely targeting of ,-catenin and NF-,B signaling, and suggest its potential usefulness for the prevention of human CRC. © 2010 Wiley-Liss, Inc. [source] Panax notoginseng saponins attenuate acute lung injury induced by intestinal ischaemia/reperfusion in ratsRESPIROLOGY, Issue 6 2009Ling RONG ABSTRACT Background and objective: Acute lung injury remains a challenge for both clinicians and scientists. The effects of Panax notoginseng saponins (PNS) on acute lung injury induced by intestinal ischaemia/reperfusion (II/R) were studied in rats. Methods: Forty-eight Wistar rats were randomly assigned to four groups: (1) a sham-operated group that received laparotomy without II/R (n= 12); (2) a sham + PNS group, which was identical to group 1 except for PNS treatment (n= 12); (3) an II/R group that had 1 h of intestinal ischaemia followed by 3 h of reperfusion (n= 12); and (4) an II/R + PNS group that received 100 mg/kg of PNS, i.v., 15 min before reperfusion (n= 12). The effects of PNS administration on lung tissue histology, activities of oxidant and antioxidant enzymes, levels of malondialdehyde, nitric oxide and inducible nitric oxide synthase activity were examined. Levels of surfactant protein B, cell numbers in BAL fluid and plasma levels of pro-inflammatory cytokines were also examined. Results: Compared with the II/R group, pulmonary parenchymal damage, activities of oxidant enzymes, levels of malondialdehyde and nitric oxide, inducible nitric oxide synthase activity in lung tissue, and plasma levels of pro-inflammatory cytokines were significantly reduced by PNS treatment. In addition, the decreases in antioxidant enzyme activities were prevented in the II/R + PNS group. Total leukocyte and neutrophil counts were significantly decreased by PNS treatment. The decline in surfactant protein B levels in BAL fluid was reduced in the II/R + PNS group compared with the II/R group. Conclusions: Administration of PNS before reperfusion injury alleviates acute lung injury induced by II/R, and this is attributable to the antioxidant and anti-inflammatory effects of PNS. [source] Distribution and function of FSH receptor genetic variants in normal menANDROLOGIA, Issue 3 2002K. Asatiani Summary. Follicle stimulating hormone (FSH) plays a key role in the maintenance of qualitatively and quantitatively normal spermatogenesis. It controls gamete development through Sertoli cells, via binding to its receptor. The influence and importance of FSH receptor (FSHR) variants on Sertoli cell function is not completely understood and remains to be investigated. In this retrospective study, we explored the impact and action of two distinct FSHR isoforms, Thr307/Asn680 and Ala307/Ser680, in a large group of men. This investigation includes 288 normal healthy men, 86 of whom were proven fathers previously studied, and 202 were newly recruited subjects. The FSHR polymorphism at position 680 was analyzed in the whole group, while position 307 was investigated in 150 subjects, both of them by single-stranded conformation polymorphism (SSCP) gel electrophoresis. The distribution frequency for position 680 was 29% for the Asn/Asn, 52% for the Asn-Ser, 19% for the Ser-Ser variant, and for position 307, 27% for the Thr-Thr, 55% for the Ala-Thr, 18% for the Ala-Ala, respectively. Polymorphism combinations that were different from Thr307/Asn680 , Ala307/Ser680 were found in four subjects. When subjects were grouped according to genotype at position 680, no significant differences between basal FSH, testosterone, inhibin B levels and semen parameters were found. This clinical finding demonstrates that, differently from females, in whom a significant correlation between FSHR polymorphism and basal FSH levels was found, the FSHR genotype has no influence on clinical parameters in males. [source] Therapeutic Effects and Anti-inflammatory Mechanisms of Heparin on Acute Lung Injury in RabbitsACADEMIC EMERGENCY MEDICINE, Issue 7 2008Meitang Wang MD Abstract Objectives:, The objectives were to investigate the potential beneficial effects and molecular mechanisms of heparin and low-molecular-weight heparin (LMWH) on acute lung injury (ALI). Methods:, Forty-eight rabbits were randomized into four groups: normal control group (Group A), lipopolysaccharide (LPS) group (Group B), LPS + heparin group (Group C), and LPS + LMWH group (Group D). The rabbit ALI model was established by intravenous (IV) injection with LPS. Alveolar,arterial O2 difference (PA-aO2), serum tumor necrosis factor , (TNF-,), circulating p38 mitogen-activated protein kinase (p38 MAPK) levels, lung nuclear factor (NF)-,B levels, and lung dry/wet (D/W) ratio were measured, and the lung injury scores were calculated. Results:, Lipopolysaccharide caused significant increases in PA-aO2, serum TNF-,, expression of p38 MAPK in polymorphonuclear neutrophils (PMNs), the lung injury scores, and nuclear factor-,B (NF-,B) activity in the lung tissue and caused a decrease in lung D/W ratio. A positive linear correlation was found between p38 MAPK and TNF-, at 1, 2, 4, and 6 hours (r = 0.68, 0.92, 0.93, and 0.93, respectively) and between NF-,B and p38 MAPK and TNF-, at 6 hours (r = 0.94 and 0.83, respectively). IV heparin or LMWH given after LPS treatment attenuated these changes in inflammatory response, oxygenation, p38 MAPK expression, and NF-,B activation. Conclusions:, The anti-inflammatory mechanisms of heparin in ALI may be inhibiting p38 MAPK and NF-,B activities, and then TNF-, overexpression, thus alleviating the inflammatory reaction. [source] Maternal IgG anti-A and anti-B titres predict outcome in ABO-incompatibility in the neonateACTA PAEDIATRICA, Issue 12 2009Egil Bakkeheim Abstract Aim:, To evaluate predictors for risk of severe hyperbilirubinaemia and kernicterus in ABO-incompatible neonates with emphasize on maternal IgG anti-A/-B titres. Methods:, Blood group O women in labour at Oslo University Hospital, Ullevål, were included in the years 2004,2006. Offspring with blood group A or B had direct antiglobulin test performed and IgG anti-A/-B levels measured in maternal plasma. Blood group A or B infants developing severe hyperbilirubinaemia, received in addition to phototherapy, immunoglobulin treatment and/or exchange transfusion (EXT). Results:, Of 253 neonates, 61.3% had blood group O, 29.6% blood group A and 9.1% blood group B. Twenty neonates with blood group A or B received at least one immunoglobulin treatment. In multivariate analysis, maternal antibody-titres were the only significant predictors for immunoglobulin treatment (p < 0.0001), EXTs (p < 0.05) and duration of phototherapy (p < 0.0001). The need for invasive treatment increased sharply for antibody titres ,512. Receiver operating characteristic analyses demonstrated that titres ,512 had a sensitivity of 90% and a specificity of 72% for predicting immunoglobulin treatment and thus severe hyperbilirubinaemia. Conclusion:, Maternal IgG anti-A/-B titres contribute to the prediction of risk of severe hyperbilirubinaemia in ABO-incompatible neonates, in addition to blood-grouping and direct antiglobulin-testing, especially following early discharge after delivery. [source] | |||||||||||||