Defective Ca(2+) handling proteins regulation during heart failure

Abnormal release of Ca(2+) from sarcoplasmic reticulum (SR) via the cardiac ryanodine receptor (RyR2) may contribute to contractile dysfunction in heart failure (HF). We previously demonstrated that RyR2 macromolecular complexes from HF rat were significantly more depleted of FK506 binding protein (FKBP12.6). Here we assessed expression of key Ca(2+) handling proteins and measured SR Ca(2+) content in control and HF rat myocytes. Direct measurements of SR Ca(2+) content in permeabilized cardiac myocytes demonstrated that SR luminal [Ca(2+)] is markedly lowered in HF (HF: DeltaF/F(0) = 26.4+/-1.8, n=12; control: DeltaF/F(0) = 49.2+/-2.9, n=10; P<0.01). Furthermore, we demonstrated that the expression of RyR2 associated proteins (including calmodulin, sorcin, calsequestrin, protein phosphatase 1, protein phosphatase 2A), Ca(2+) ATPase (SERCA2a), PLB phosphorylation at Ser16 (PLB-S16), PLB phosphorylation at Thr17 (PLB-T17), L-type Ca(2+) channel (Cav1.2) and Na(+)- Ca(2+) exchanger (NCX) were significantly reduced in rat HF. Our results suggest that systolic SR reduced Ca(2+) release and diastolic SR Ca(2+) leak (due to defective protein-protein interaction between RyR2 and its associated proteins) along with reduced SR Ca(2+) uptake (due to down-regulation of SERCA2a, PLB-S16 and PLB-T17), abnormal Ca(2+) extrusion (due to down-regulation of NCX) and defective Ca(2+) -induced Ca(2+) release (due to down-regulation of Cav1.2) could contribute to HF.

Differentiation of ruminant transmissible spongiform encephalopathy isolate types, including bovine spongiform encephalopathy and CH1641 scrapie

With increased awareness of the diversity of transmissible spongiform encephalopathy (TSE) strains in the ruminant population, comes an appreciation of the need for improved methods of differential diagnosis. Exposure to bovine spongiform encephalopathy (BSE) has been associated with the human TSE, variant Creutzfeldt-Jakob disease, emphasizing the necessity in distinguishing low-risk TSE types from BSE. TSE type discrimination in ruminants such as cattle, sheep, goats and deer, requires the application of several prion protein (PrP)-specific antibodies in parallel immunochemical tests on brain homogenates or tissue sections from infected animals. This study uses in a single incubation step, three PrP-specific antibodies and fluorescent Alexa dye-labelled anti-mouse Fabs on a Western blot. The usual amount of brain tissue needed is 0.5 mg. This multiplex application of antibodies directed towards three different PrP epitopes enabled differential diagnosis of all established main features of classical scrapie, BSE and Nor98-like scrapie in sheep and goats, as well as the currently known BSE types C, H and L in cattle. Moreover, due to an antibody-dependent dual PrP-banding pattern, for the first time CH1641 scrapie of sheep can be reliably discriminated from the other TSE isolate types in sheep.

Short axis contact in the chaining of ellipsoidal particles of polar molecule dominated electrorheological fluid

We simulate the effect of the chaining direction of ellipsoidal particles of polar molecule dominated electrorheological (PM-ER) fluids using commercially available COMSOL Multiphysics® software for the distribution of electric field and the total electrostatic energy. It is proved that adding ferroelectric materials to the channels parallel to the short axis would make the short axis parallel to the field direction when the ellipsoidal particles are chained under an electric field. According to our simulation, while the concentration of the channels stays constant, the greater the dielectric constant of the inserted material, the stronger the maximum local electric field will be.

Postconditioning and remote postconditioning of ischemic rat cardiac grafts

BACKGROUND

Global warm ischemia of transplanted cardiac grafts is associated with apoptosis and subsequent tissue necrosis. It is suggested that postconditioning (PostC) may ameliorate the early outcome of cardiac grafts after ischemia-reperfusion. We investigated whether PostC and remote postconditioning (RPostC) have a histopathologic impact after transplantation of warm ischemic rat cardiac grafts.

MATERIALS AND METHODS

Thirteen rats were randomized to undergo either PostC or RPostC after heterotopic transplantation of ischemic cardiac grafts. Six rats without intervention besides transplantation served as controls (control). The recipient rats were sacrificed 24 h after transplantation to evaluate histopathology and apoptotic index.

RESULTS

No significant differences were observed between the study groups in terms of graft heat shock protein 70 and oxygen radical absorbing capacity, an indicator of antioxidant capacity. While apoptosis and PCARB, a marker of protein oxidation and oxidative stress, decreased after RPostC (p < 0.05), contraction band necrosis was less prominent in both PostC and RPostC.

CONCLUSION

Both PostC and RPostC have a histopathologic impact after 24 h of reperfusion of warm ischemic rat cardiac grafts.

Increased 18F-FDG uptake and expression of Glut1 in the EMT transformed breast cancer cells induced by TGF-beta

As carcinomas progress, the tumors may lose epithelial morphology and acquire mesenchymal characteristics typically called epithelial-mesenchymal transition (EMT), which is commonly associated with increased cell migration, enables cells to dissociate from their original tissue and form metastasis in distant organs. In addition to molecular and morphologic changes, the EMT transformed cells also showed the change of sensitivity to chemotherapeutics. In order to detect the EMT transition in vivo clinically, we detected the change of metabolism of MCF-7 cells after being induced by TGF-beta to form EMT condition by MTT and 18F-FDG uptake.

Pharmacokinetics and delta1-cortienic acid excretion after intravenous administration of prednisolone and loteprednol etabonate in rats

Detailed pharmacokinetic (PK) studies in rats were performed (i)to compare the PK of prednisolone (PRN) and loteprednol etabonate (LE, a soft corticosteroid) as well as their common inactive metabolite delta1-cortienic acid (delta1-CA), (ii) to investigate the excretion of delta1-CA after PRN and LE administration, and (iii) to investigate the effect of delta1-unsaturation on the excretion of delta1-CA versus CA. Following a 10 mg x kg(-1) intravenous bolus dose, the total clearance (CL(tot)) of PRN (27.0 +/- 1.4 mL x min(-1) kg(-1)) was significantly lower than that of LE (67.4 +/- 11.6 mL x min(-1) kg(-1)) or delta1-CA (53.8 +/- 1.4 mL x min(-1) kg(-1)) indicating that the metabolism/elimination of PRN in the liver (primarily, conjugation) may be less efficient than that of LE (primarily, hydrolysis) or delta1-CA (unchanged). The volume of distribution (Vd(ss)) of PRN (823 +/- 78 mL x kg(-1)) was significantly lower than that of LE (3078 +/- 79 mL x kg(-1)) indicating that LE is more distributed to lipophilic tissues. Excretion studies have confirmed that delta1-CA is indeed a metabolite of PRN. After intravenous injection of 10 mg x kg(-1), less than 1% of the administered PRN was excreted as delta1-CA by 4 h (0.38 +/- 0.10% in bile and 0.18 +/- 0.04% in urine), significantly less than for LE (17.01 +/- 2.09% in bile and 2.53 +/- 1.17% in urine) indicating that extent of this metabolic transformation can indeed be affected by molecular design. At doses of 100 mg/kg, the proportion of delta1-CA excreted after PRN administration (0.12 +/- 0.03% in bile and 0.19 +/- 0.03% in urine) was similar to that of CA excreted after hydrocortisone administration (0.11 +/- 0.03% in bile and 0.22 +/- 0.04% in urine) indicating that the presence of the delta1 double bond (delta1-unsaturation) does not affect significantly this metabolic conversion.

Ultrathin W-Al dual interlayer approach to depositing smooth and adherent nanocrystalline diamond films on stainless steel

The adherence of diamond coated on steel is commonly low and needs to be strengthened with thick intermediate layers. In this paper, a nanoscale W-Al dual metal interlayer has been applied on SS304 substrates to facilitate deposition of continuous, adherent and smooth diamond thin films. During the microwave plasma-enhanced chemical vapor deposition process, the Al inner layer 30 nm thick diffuses into steel surface inhibiting carbon diffusion and graphitization. The W outer layer 20 nm thick is transformed into W carbides, both preventing carbon diffusion and enhancing diamond nucleation. The diamond films synthesized are of high purity and have smooth surfaces and dense structures. Indentation and shear deformation tests indicate high delaminating tolerance of the diamond films.

Aflatoxin-albumin adducts and correlation with decreased serum levels of vitamins A and E in an adult Ghanaian population

A study of aflatoxin (AF) exposure and the levels of vitamins A and E was carried out with a group of 507 Ghanaian participants. AFB(1)-albumin adducts (AFB-AA) were measured by radioimmunoassay and vitamins A and E were measured by high-performance liquid chromatography (HPLC). The average level of serum AFB-AA was 0.94 +/- 0.64 (range = 0.1-4.44) pmol mg(-1) albumin. Mean levels of vitamins A and E were 1.32 +/- 0.48 (range = 0.41-4.85) micromol l(-1) and 15.68 +/- 4.12 (range = 6.35-30.40) micromol l(-1), respectively. A significantly negative correlation was found between serum AFB-AA and vitamin A levels (r = -0.110, p = 0.013). An even stronger, significant negative, correlation was found between serum AFB-AA and vitamin E levels (r = -0.149, p < 0.001). Serum AFB-AA levels were statistically higher (median = 0.985 pmol mg(-1) albumin) in subjects who had low levels of both vitamins A and E as compared with the levels (median = 0.741 pmol mg(-1) albumin) subjects who had high vitamins A and E levels (p(trend) = 0.001). To verify these findings, blood samples were again collected from 165 of the 507 people 3 months after the initial collection. Significantly negative correlations were confirmed between levels of serum AFB-AA and both vitamins A (r = -0.232, p = 0.003) and E (r = -0.178, p = 0.023). Again, high serum AFB-AA concentrations (median = 1.578 pmol mg(-1) albumin) were found in subjects with low levels of vitamins A and E compared with the concentrations (median = 1.381 pmol mg(-1) albumin) in subjects with high levels of vitamins A and E (p(trend) = 0.002). These data show that AF exposure was associated with decreased levels of serum vitamins A and E in high-risk human populations, which may significantly influence the incidence of AF-related adverse health effects.

Oxidative Stress and Apoptosis of Human Brain Microvascular Endothelial Cells Induced by Free Fatty Acids

Damage to endothelial cells is a key event in the pathogenesis of atherosclerosis and vascular disease. This study aimed to determine whether free fatty acids (FFAs) induced oxidative stress and apoptosis in human brain microvascular endothelial cells (HBMVECs) in vitro and, if so, which signalling pathway mediated these effects. After culture in different concentrations of FFAs for 24-72 h, cell viability/proliferation was determined using a cell counting kit, apoptosis was detected by measuring caspase-3 activity and by using annexin V-conjugated fluorescein isothiocyanate/propidium iodide staining, and oxidative stress was evaluated by measuring the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP). The HBMVECs exposed to FFAs showed significantly decreased cell proliferation, increased apoptosis and ROS levels, and decreased MMP. In conclusion, the results showed that high levels of FFAs induced oxidative stress, which damaged HBMVECs and resulted in apoptosis.

Role of hypoxia-inducible factor-1 alpha in the regulation of plasminogen activator activity in rat knee joint chondrocytes

OBJECTIVE

To examine the effects of hypoxia-inducible factor-1alpha (HIF-1alpha) on the plasminogen activator's (PA) activity and on the expression of components of PA system in articular chondrocytes of rats.

METHODS

Chondrocytes from rat knee joint cartilage were cultured under normoxic, hypoxic, CoCl(2) simulated hypoxic, and interleukin-1beta (IL-1beta)-stimulated conditions. siRNA targeting HIF-1alpha was transfected into cells cultured under hypoxic, simulated hypoxic, and IL-1beta-stimulated conditions to silence HIF-1alpha. PA activity was determined by the hydrolysis of the chromogenic substrate H-D-Val-Leu-Lys-pNA (S-2251). The mRNA levels were measured by quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). The intracellular/matrix-associate protein levels were detected by Western blot and the soluble protein levels were measured by enzyme linked immunosorbent assay (ELISA). Chromatin immunoprecipitation (CHIP) assay was performed to determine whether HIF-1alpha binds to the hypoxia response element (HRE) of target genes.

RESULTS

The enhancement of HIF-1alpha by CoCl(2) resulted in a decrease of PA activity, and the silence of HIF-1alpha by siRNA led to an increase of PA activity. The PA inhibitor-1 (PAI-1) mRNA and protein were increased by hypoxia or simulated hypoxia, which was reversed by the siRNA2-mediated silencing of HIF-1alpha. CHIP assay further confirmed that the induction of PAI-1 involved the binding of HIF-1alpha to the PAI-1 promoter, while the enhancement or silencing of HIF-1alpha did not affect the expression of urokinase type PA (uPA), tissue type PA (tPA) or uPA receptor (uPAR). Additionally, IL-1beta stimulated both HIF-1alpha and PAI-1 in articular chondrocytes, and the IL-1beta-mediated induction of PAI-1 was inhibited partly by HIF-1alpha silencing.

CONCLUSION

HIF-1alpha may inhibit the PA activity through stimulating the expression of PAI-1 in normal articular chondrocytes. The inhibition of HIF-1alpha in the PA activity of articular chondrocytes probably plays an important role in the maintenance of articular cartilage matrix.

Feasibility of focused ultrasound therapy for recurrent cervicitis with high-risk human papillomavirus infection

OBJECTIVE

To investigate the feasibility of focused ultrasound therapy for recurrent cervicitis with high-risk human papillomavirus (HR-HPV) infection.

METHODS

This was a prospective clinical study, in which 20 patients with HR-HPV-positive recurrent cervicitis were enrolled. Focused ultrasound therapy was performed by one gynecologist. All patients were followed up for 6 months after ultrasound therapy. Telephone interviews, colposcopic examinations and Hybrid Capture II tests were performed to assess the safety and effectiveness of focused ultrasound therapy for HR-HPV-positive cervicitis.

RESULTS

Ultrasound therapy was tolerated well, and no severe complications were observed in any patient. Vaginal discharge was found intermittently in 95% of patients. Without any intervention this disappeared 1 month after ultrasound therapy. Patients' symptoms were relieved significantly by ultrasound therapy, including 88.9% patients who had abundant leukorrhea, 80% who had pelvic pain and 87.5% who had postcoital bleeding. No colposcopic evidence of cervicitis remained postoperatively in 75% of patients, and cytological examination showed that the lesions had disappeared in 80% of patients. Follow-up HPV testing revealed that 75% of patients presented negative HR-HPV infection following treatment.

CONCLUSIONS

Focused ultrasound therapy is feasible and effective in the treatment of patients with HR-HPV-positive cervicitis. It may provide a useful non-invasive treatment for recurrent cervicitis with HR-HPV infection.