TMPO-AS1 is an independent prognostic factor for patients with laryngeal squamous cell carcinoma

SUMMARY OBJECTIVE Long noncoding RNA (lncRNAs) are frequently abnormally expressed in tumors and involved in the occurrence and progression of human cancer. Recently, a disease-related lncRNA, TMPO antisense RNA 1 (TMPO-AS1), was identified to be dysregulated in several tumors. Hence, we aimed to demonstrate whether TMPO-AS1 could be a promising prognostic marker for patients with laryngeal squamous cell carcinoma (LSCC). METHODS RT-PCR was performed to test TMPO-AS1 expressions in 187 LSCC specimens compared with matched normal specimens. Chi-squared tests were used to determine the associations between TMPO-AS1 expressions and the clinicopathological characteristics of LSCC patients. Then, the clinical outcome of LSCC patients who had lower or higher TMPO-AS1 expression was analyzed using Kaplan-Meier assays. Finally, a Cox proportional hazards model was carried out to evaluate the prognostic values of TMPO-AS1 and other clinical features. RESULTS We found that TMPO-AS1 was distinctly upregulated in human LSCC tissues compared with corresponding normal specimens (p < 0.01). Higher expressions of TMPO-AS1 were observed to be positively associated with the clinical stage (p = 0.020) and lymph node metastasis (p = 0.027). A clinical study in 187 patients revealed that patients with TMPO-AS1 low expressions had poorer survival than those with TMPO-AS1 high expressions (p = 0.0012). In addition, the result of multivariate assays demonstrated TMPO-AS1 expression is an independent predictor for the overall survival of LSCC patients. CONCLUSIONS TMPO-AS1 might be considered a novel molecule involved in LSCC progression, which provides a possible prognostic biomarker.

RESUMO OBJETIVO RNAs longos não-codificantes (INcRNAs) são frequentemente expressos anormalmente em tumores e estão envolvidos na ocorrência e progressão do câncer humano. Recentemente, um INcRNA relacionado com a doença, o TMPO antisense RNA 1 (TMPO-AS1), foi identificado como desregulado em vários tumores. Por isso, procuramos demonstrar se o TMPO-AS1 poderia ser um marcador de prognóstico promissor para pacientes com carcinoma de células escamosas da laringe (LSCC). MÉTODOS RT-PCR foi realizado para medir as expressões do TMPO-AS1 em 187 espécimes de LSCC em comparação com espécimes normais correspondentes. Foram utilizados testes Qui-quadrado para determinar as associações entre as expressões do TMPO-AS1 e as características clínicas dos pacientes com LSCC. Em seguida, o desfecho clínico dos pacientes com LSCC que tinham uma expressão do TMPO-AS1 inferior ou superior foi analisado com ensaios Kaplan-Meier. Por último, o modelo de riscos proporcionais de Cox foi utilizado para avaliar o valor prognóstico do TMPO-AS1 e outras características clínicas. RESULTADOS Observamos que o TMPO-AS1 estava claramente super-regulado nos tecidos de LSCC humanos em comparação com os espécimes normais correspondentes (p<0,01). Expressões mais elevadas de TMPO-AS1 estavam positivamente associadas ao estágio clínico (p=0,020) e à metástase linfática (p=0,027). Um estudo clínico com 187 pacientes revelou que aqueles com expressões mais baixas de TMPO-AS1 tiveram uma sobrevida pior do que aqueles com expressões elevadas de TMPO-AS1 (p=0,0012). Além disso, o resultado de ensaios multivariados demonstrou que a expressão do TMPO-AS1 é um preditor independente para a sobrevida global de pacientes com LSCC. CONCLUSÕES TMPO-AS1 pode ser considerado uma molécula nova envolvida na progressão do LSCC, o que proporciona um possível biomarcador de prognóstico.

Effect of the chemoprotectant tempol on anti-tumor activity of cisplatin / 南方医科大学学报

OBJECTIVE@#To investigate the effect of the chemoprotectant tempol on the anti-tumor activity of cisplatin (DDP).@*METHODS@#The cellular toxicity of tempol in human colon cancer SW480 cells and mouse colon cancer CT26 cells were evaluated using MTT and cell counting kit-8 assays. CalcuSyn software analysis was used to determine the interaction between tempol and DDP in inhibition of the cell viability. A subcutaneous homograft mouse model of colon cancer was established. The mice were randomly divided into control group, tempol group, cisplatin group and tempol + DDP treatment group with intraperitoneal injections of the indicated agents. The tumor size, body weight and lifespan of the mice were measured, and HE staining was used to analyze the cytotoxic effect of the agents on the kidney and liver. Immunohistochemistry and Western blotting were performed to detect the expression of Bax and Bcl2 in the tumor tissue, and TUNEL staining was used to analyze the tumor cell apoptosis. The level of reactive oxygen species (ROS) in the tumor tissue was determined using flow cytometry.@*RESULTS@#Tempol showed inhibitory effects on the viability of SW480 and CT26 cells. CalcuSyn software analysis showed that tempol had a synergistic anti-tumor effect with DDP (CI < 1). In the homograft mouse model, tempol treatment alone did not produce obvious anti-tumor effect. HE staining showed that the combined use of tempol and DDP alleviated DDP-induced fibrogenesis in the kidneys, but tempol also reduced the anti-tumor activity of DDP. Compared with the mice treated with DDP alone, the mice treated with both tempol and DDP had a significantly larger tumor size ( < 0.01) and a shorter lifespan ( < 0.05). Tempol significantly reversed DDP-induced expression of Bax and Bcl2 in the tumor tissue and tumor cell apoptosis ( < 0.001), and obviously reduced the elevation of ROS level in the tumor tissue induced by DDP treatment ( < 0.05).@*CONCLUSIONS@#Tempol can attenuate the anti-tumor effect of DDP while reducing the side effects of DDP. Caution must be taken and the risks and benefits should be carefully weighed when considering the use of tempol as an anti-oxidant to reduce the toxicities of DDP.

Inflammation induced by increased frequency of intermittent hypoxia is attenuated by tempol administration

The levels of serum inflammatory cytokines and the activation of nuclear factor kappa B (NF-κB) and hypoxia inducible factor-1α (HIF-1α) in heart tissues in response to different frequencies of intermittent hypoxia (IH) and the antioxidant tempol were evaluated. Wistar rats (64 males, 200-220 g) were randomly divided into 6 experimental groups and 2 control groups. Four groups were exposed to IH 10, 20, 30, or 40 times/h. The other 2 experimental groups were challenged with IH (30 times/h) plus tempol, either beginning on day 0 (IH30T0) or on day 29 (IH30T29). After 6 weeks of challenge, serum levels of tumor necrosis factor (TNF)-α, intracellular adhesion molecule (ICAM)-1, and interleukin-10 were measured, and western blot analysis was used to detect NF-κB p65 and HIF-1α in myocardial tissues. Serum levels of TNF-α and ICAM-1 and myocardial expression of NF-κB p65 and HIF-1α were all significantly higher in IH rats than in controls (P<0.001). Increased IH frequency resulted in more significant changes. Administration of tempol in IH rats significantly reduced levels of TNF-α, ICAM-1, NF-κB and HIF-1α compared with the non-tempol-treated group (F=16.936, P<0.001). IH induced an inflammatory response in a frequency-dependent manner. Additionally, HIF-1α and NF-κB were increased following IH administration. Importantly, tempol treatment attenuated this effect.

Role of renal sympathetic nerve and oxidative stress in foot shock-induced hypertension in rats / 生理学报

The present study was aimed to investigate the roles of renal sympathetic nerve and oxidative stress in the development of foot shock-induced hypertension. Ninety rats were divided into 6 groups (the number of each group was 15): control group, foot shock group, denervation of renal sympathetic nerve group, denervation of renal sympathetic nerve + foot shock group, Tempol treatment + foot shock group, denervation of renal sympathetic nerve + Tempol treatment + foot shock group. Rats were received electrical foot shock for 14 days (2-4 mA, 75 V, shocks of 50-100 ms every 30 s, for 4 h each session through an electrified grid floor every day). Renal sympathetic ablation was used to remove bilateral renal sympathetic nerve in rats (rats were allowed to recover for one week before the beginning of the foot shock procedure). The antioxidant Tempol was injected intraperitoneally at 1 h before foot shock. Systolic blood pressure was measured at 1 h after foot shock on day 0, 3, 7, 10 and 14. Contents of thiobarbituric acid reactive substance (TBARS), renin, angiotensin II (AngII) and glutathione peroxidase (GSH-Px) in plasma were measured by ELISA after 14-day foot shock. The results showed that systolic blood pressure of foot shock group was significantly increased (P < 0.05) compared with that of control group from day 7 to day 14 of foot shock. Denervation of renal sympathetic nerve and/or Tempol treatment significantly reduced the increase of systolic blood pressure induced by foot shock. Levels of TBARS, renin and AngII in plasma were increased significantly in foot shock group compared with that of control group (P < 0.05). Plasma GSH-Px concentration was decreased in foot shock group rats compared with that of control group (P < 0.05). Denervation of renal sympathetic nerve and/or tempol treatment significantly reduced the increase in TBARS, renin, AngII levels induced by foot shock in comparison with that of foot shock group (P < 0.05), but had no effects on the reduction of GSH-Px concentration. The results suggest that renal sympathetic nerve may play an important role in the development of foot shock-induced hypertension, and renal sympathetic nerve may influence oxidative stress and directly or indirectly activate renin-angiotensin-aldosterone system, so the foot shock-induced high blood pressure may be maintained and hypertension may therefore be produced.

Lipoic acid, but not tempol, preserves vascular compliance and decreases medial calcification in a model of elastocalcinosis

Vascular calcification decreases compliance and increases morbidity. Mechanisms of this process are unclear. The role of oxidative stress and effects of antioxidants have been poorly explored. We investigated effects of the antioxidants lipoic acid (LA) and tempol in a model of atherosclerosis associated with elastocalcinosis. Male New Zealand white rabbits (2.5-3.0 kg) were fed regular chow (controls) or a 0.5% cholesterol (chol) diet+104 IU/day vitamin D2 (vitD) for 12 weeks, and assigned to treatment with water (vehicle, n=20), 0.12 mmol·kg-1·day-1 LA (n=11) or 0.1 mmol·kg-1·day-1 tempol (n=15). Chol+vitD-fed rabbits developed atherosclerotic plaques associated with expansive remodeling, elastic fiber disruption, medial calcification, and increased aortic stiffness. Histologically, LA prevented medial calcification by ∼60% and aortic stiffening by ∼60%. LA also preserved responsiveness to constrictor agents, while intima-media thickening was increased. In contrast to LA, tempol was associated with increased plaque collagen content, medial calcification and aortic stiffness, and produced differential changes in vasoactive responses in the chol+vitD group. Both LA and tempol prevented superoxide signals with chol+vitD. However, only LA prevented hydrogen peroxide-related signals with chol+vitD, while tempol enhanced them. These data suggest that LA, opposite to tempol, can minimize calcification and compliance loss in elastocalcionosis by inhibition of hydrogen peroxide generation.

Toxic effects of strychnine and strychnine N-oxide on zebrafish embryos / 中国天然药物

AIM@#The application of strychnine (S) is limited due to its toxicity; strychnine N-oxide (SNO) is a derivative of strychnine. The aim was to employ zebrafish embryos to investigate and compare the developmental toxicity induced by S and SNO.@*METHODS@#The toxicity of S and SNO was examined through the hatching rate and survival rate. Morphological changes of the zebrafish were observed with a dissecting microscope. Apoptosis was detected through acridine orange (AO) staining and flow cytometry. Apoptotic genes were measured by RT-PCR.@*RESULTS@#Embryo malformation was observed in the embryos exposed to S at 200 μmol·L(-1). When SNO concentration was increased to 1 mmol·L(-1), scoliolosis, and pericardial edema could be seen in some embryos. Results from fluorescence microscopy and flow cytometry analysis showed that S at 200 μmol·L(-1) induced apoptosis, whereas the apoptotic rate in the SNO-treated group (200 μmol·L(-1)) was much lower than that in the S group. RT-PCR analysis showed that p53 mRNA expression and the ratio of Bax/Bcl-2 in the S group were significantly altered compared with the control group (*P < 0.05). Moreover, Bax mRNA expression in both S and SNO group were significantly different from that in the control group (**P < 0.01).@*CONCLUSION@#These results lead to the conclusion that SNO has significantly lower toxicity than S in zebrafish embryos.

Tempol Attenuates Renal Fibrosis in Mice with Unilateral Ureteral Obstruction: The Role of PI3K-Akt-FoxO3a Signaling

This study investigated whether tempol, an anti-oxidant, protects against renal injury by modulating phosphatidylinositol 3-kinase (PI3K)-Akt-Forkhead homeobox O (FoxO) signaling. Mice received unilateral ureteral obstruction (UUO) surgery with or without administration of tempol. We evaluated renal damage, oxidative stress and the expression of PI3K, Akt, FoxO3a and their target molecules including manganese superoxide dismutase (MnSOD), catalase, Bax, and Bcl-2 on day 3 and day 7 after UUO. Tubulointerstitial fibrosis, collagen deposition, alpha-smooth muscle actin-positive area, and F4/80-positive macrophage infiltration were significantly lower in tempol-treated mice compared with control mice. The expression of PI3K, phosphorylated Akt, and phosphorylated FoxO3a markedly decreased in tempol-treated mice compared with control mice. Tempol prominently increased the expressions of MnSOD and catalase, and decreased the production of hydrogen peroxide and lipid peroxidation in the obstructed kidneys. Significantly less apoptosis, a lower ratio of Bax to Bcl-2 expression and fewer apoptotic cells in TUNEL staining, and decreased expression of transforming growth factor-beta1 were observed in the obstructed kidneys from tempol-treated mice compared with those from control mice. Tempol attenuates oxidative stress, inflammation, and fibrosis in the obstructed kidneys of UUO mice, and the modulation of PI3K-Akt-FoxO3a signaling may be involved in this pathogenesis.

Effect of inhibiting brain reactive oxygen species on sympathetic nerve activity in DOCA-salt hypertensive rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate whether brain reactive oxygen species mediate sympathoexcitation and arterial pressure elevation in DOCA-salt hypertensive rats.</p><p><b>METHODS</b>DOCA-salt hypertensive model was established in male SD rats by subcutaneous injection of DOCA after uninephrectomy and drinking 1% NaCl solution for 4 weeks. The baseline mean arterial pressure (MAP), heart rate (HR) and renal sympathetic nerve activity (RSNA) were recorded in the rats under mild anesthesia, and MAP changes following intravenous hexamethonium injection were observed. The responses of MAP, HR and RSNA to intracerebroventricular administration of tempol (20 µmol/L in 10 µl) were evaluated; plasma NE level was measured with ELISA, and ROS level and NAD(P)H oxidase activity in the hypothalamus were detected using chemiluminescence assay.</p><p><b>RESULTS</b>MAP and plasma NE levels were significantly increased in DOCA-salt rats as compared with those in the control group (P<0.01). In DOCA-salt hypertensive rats, intravenous hexamethonium injection induced a blood pressure reduction 240% of that in control rats, and significantly increased the levels of superoxide anion and NAD(P)H oxidase activity in the hypothalamus. Intracerebroventricular microinjection of tempol also resulted in more significant changes of MAP, HR and RSNA in DOCA-salt rats than in the control group (P<0.01).</p><p><b>CONCLUSION</b>Sympathoexcitation due to increased NAD(P)H oxidase-derived ROS levels in the hypothalamus may mediate arterial pressure elevation in DOCA-salt hypertensive rats.</p>

Estrogen receptor alpha polymorphism in boys with constitutional delay of growth and puberty

PURPOSE: There were a lot of reports regarding associations of polymorphisms in the estrogen receptor alpha (ESR1). with many disorders. But, those with constitutional delay of growth and puberty (CDGP) are not known. Our aim is to find out any association between CDGP and ESR1. METHODS: In a total of 27 subjects, we compared 7 CDGP patients with 20 healthy controls with their heights and sexual maturity rates were within normal range. We selected three single nucleotide polymorphisms from intron 1 of ESR1 (rs3778609, rs12665044, and rs827421) as candidates, respectively. RESULTS: In genotype analyses, the frequency of G/G genotype at rs827421 in intron 1 of ESR1 was increased in CDGP boys (P=0.03). CONCLUSION: The genetic variation of ESR1 can be a contributing factor of tempo of growth and puberty.

Estrogen receptor alpha polymorphism in boys with constitutional delay of growth and puberty

PURPOSE: There were a lot of reports regarding associations of polymorphisms in the estrogen receptor alpha (ESR1). with many disorders. But, those with constitutional delay of growth and puberty (CDGP) are not known. Our aim is to find out any association between CDGP and ESR1. METHODS: In a total of 27 subjects, we compared 7 CDGP patients with 20 healthy controls with their heights and sexual maturity rates were within normal range. We selected three single nucleotide polymorphisms from intron 1 of ESR1 (rs3778609, rs12665044, and rs827421) as candidates, respectively. RESULTS: In genotype analyses, the frequency of G/G genotype at rs827421 in intron 1 of ESR1 was increased in CDGP boys (P=0.03). CONCLUSION: The genetic variation of ESR1 can be a contributing factor of tempo of growth and puberty.

Electron paramagnetic resonance study of lipid and protein membrane components of erythrocytes oxidized with hydrogen peroxide

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to monitor membrane dynamic changes in erythrocytes subjected to oxidative stress with hydrogen peroxide (H2O2). The lipid spin label, 5-doxyl stearic acid, responded to dramatic reductions in membrane fluidity, which was correlated with increases in the protein content of the membrane. Membrane rigidity, associated with the binding of hemoglobin (Hb) to the erythrocyte membrane, was also indicated by a spin-labeled maleimide, 5-MSL, covalently bound to the sulfhydryl groups of membrane proteins. At 2% hematocrit, these alterations in membrane occurred at very low concentrations of H2O2 (50 µM) after only 5 min of incubation at 37°C in azide phosphate buffer, pH 7.4. Lipid peroxidation, suggested by oxidative hemolysis and malondialdehyde formation, started at 300 µM H2O2 (for incubation of 3 h), which is a concentration about six times higher than those detected with the probes. Ascorbic acid and α-tocopherol protected the membrane against lipoperoxidation, but did not prevent the binding of proteins to the erythrocyte membrane. Moreover, the antioxidant (+)-catechin, which also failed to prevent the cross-linking of cytoskeletal proteins with Hb, was very effective in protecting erythrocyte ghosts from lipid peroxidation induced by the Fenton reaction. This study also showed that EPR spectroscopy can be useful to assess the molecular dynamics of red blood cell membranes in both the lipid and protein domains and examine oxidation processes in a system that is so vulnerable to oxidation.

The Effect of Inclusion of Rhythmic Music on the Effectiveness of Basic Life Support (BLS) Education

PURPOSE: An adequate chest compression rate during CPR is associated with improved hemodynamics and primary survival rate. The purpose of this study was to compare performance based measures of chest compression (CC), including compression rate and depth, from two versions of a CPR course: Instructor-led (IL) training, and the same IL training but augmented with rhythmic music. METHODS: Ninety-one medical students having completed the BLS provider course, 4 months prior, participated in CPR quality improvement education. Participants performed 2 min of CC on a manikin utilizing an accelerometer-based system that measured both rate (CC/min) and depth (cm) of CC. CC parameters were evaluated three times: prior to the education, immediately after the education, and again after four months. CPR quality was analyzed using the manikin/accelerometer system. The primary outcome measures included: (1) compression rate, (2) compression depth, (3) percentage of compressions performed with adequate rate, (4) percentage of compressions performed with adequate depth, (5) absolute deviation from 100 in terms of compression rate, and (6) each 2 minute test was divided into 4 30 second sections, and any rate differences between the 4 sections were assessed. For the augmented IL study, popular music with a tempo of 100 beats per minute was utilized. RESULTS: There were no differences in CC rate and depth between the two IL trainings. However, students offered IL training augmented with musical rhythm performed CC with a higher percentage of adequate rate and depth. They also had less absolute deviation and variation of CC rate difference between the four, 30 second sections, than students instructed without the use of rhythmic music. CONCLUSION: Students receiving IL training augmented with music performed adequate, standardized CC with a steadier rate than those who received IL training without the benefit of music. This result provides evidence to support the use of rhythmic music in improving BLS education results.

[Effects of tempol on in vitro development of mouse embryos under oxidative stress]

Etiologically, oxidative stress can be considered as one of the reasons for defective embryonic development which leads to developmental arrest due to necrosis or apoptosis. Under in vivo conditions, multiple mechanisms act to protect the embryo against reactive oxygen species [ROS], but under in vitro conditions most of these mechanisms are absent leading to higher levels of ROS in the culture medium. The objective of this study was to compare the antioxidant effects of Tempol, 4-hydroxy-2, 2, 6, 6-tetramethylpiperidine-l-oxyl, a permeable synthetic antioxidant, on mouse preimplantation embryonic development in vitro conditions in the presence or absence of oxidative stress. Mature oocytes from mouse were retrieved following ovarian stimulation by the administration of Pregnant Mare Serum Gonadotropin [PMSG] and hCG. Upon in vitro fertilization, the zygotes were cultured in different groups in HTF medium containing 4 mg/ml BSA. To study the effects of oxidative stress on embryo development, the zygotes were cultured for an hour in a medium containing different concentrations of H[2]O[2]. After washing, the zygotes were transferred to the culture plate. The zygotes were later placed in the media containing different concentrations of Tempol following their culture in 10 microM H[2]O[2] for one hour to study the effects of different concentrations of the substance in the absence of other oxidative stresses. The data were later compared and statistically analyzed. The pre-implantation embryonic development decreased significantly in the case group, compared to the control group after a short exposure to H[2]O[2], - the effect being more noticeable in higher concentrations. Tempol reduced the impairments resulting from the oxidative stress to some extent. Under in vitro conditions and a concentration of 0.5 microM, Tempol improved embryonic development quality, quantitatively and morphologically. Tempol increased the percentage of two-cell embryos from 91.78% in the control group to 96.99% [p < 0.05], blastocysts from 67.80% in the controls to 81.33% [p < 0.05] in the cases, and significantly decreased embryonic arrest from 32.19% in the controls to 18.67% in the cases [p < 0.05]. ROS has a major role in embryonic arrest, witnessed in embryo cultures in vitro conditions. The present study showed that supplementation of embryo cultures with Tempol improved the embryonic development. It seems that addition of permeable synthetic antioxidants, such as Tempol, to embryo cultures could protect embryos from oxidative damage and improve embryonic development

Nitric Oxide Is an Essential Mediator for Neuronal Differentiation of Rat Primary Cortical Neuron Cells

Nitric oxide (NO) regulates proliferation, differentiation and survival of neurons. Although NO is reported to involve in NGF-induced differentiation of PC12 cells, the role of NO has not been characterized in primary neuron cells. Therefore, we investigated the role of NO in neuronal differentiation of primary cortical neuron cells. Primary cortical neuron cells were prepared from rat embryos of embryonic day 18 and treated with NMMA (NOS inhibitor) or PTIO (NO scavenger). Neurite outgrowth of neuron cells was counted and the mRNA levels of p21, p27, c-jun and c-myc were measured by RT-PCR. Neurite outgrowth of primary cortical neuron cells was inhibited a little by NOS inhibitor and completely by NO scavenger. The mRNA levels of p21 and p27, differentiation-induced growth arrest genes were increased during differentiation, but they were decreased by NOS inhibitor or NO scavenger. On the other hand, the level of c-jun mRNA was not changed and the level of c-myc mRNA was increased during differentiation differently from previously reported. The levels of these mRNA were reversed in NOS inhibitor- or NO scavenger-treated cells. The level of nNOS protein was not changed but NOS activity was inhibited largely by NOS inhibitor or NO scavenger. These results suggest that NO is an essential mediator for neuronal differentiation of primary cortical neuron cells.

Sintering behavior and mechanical properties of zirconia compacts fabricated by uniaxial press forming

PURPOSE: The purpose of this study was to compare the linear sintering behavior of presintered zirconia blocks of various densities. The mechanical properties of the resulting sintered zirconia blocks were then analyzed. MATERIAL AND METHODS: Three experimental groups of dental zirconia blocks, with a different presintering density each, were designed in the present study. Kavo Everest(R) ZS blanks (Kavo, Biberach, Germany) were used as a control group. The experimental group blocks were fabricated from commercial yttria-stabilized tetragonal zirconia powder (KZ-3YF (SD) Type A, KCM. Corporation, Nagoya, Japan). The biaxial flexural strengths, microhardnesses, and microstructures of the sintered blocks were then investigated. The linear sintering shrinkages of blocks were calculated and compared. RESULTS: Despite their different presintered densities, the sintered blocks of the control and experimental groups showed similar mechanical properties. However, the sintered block had different linear sintering shrinkage rate depending on the density of the presintered block. As the density of the presintered block increased, the linear sintering shrinkage decreased. In the experimental blocks, the three sectioned pieces of each block showed the different linear shrinkage depending on the area. The tops of the experimental blocks showed the lowest linear sintering shrinkage, whereas the bottoms of the experimental blocks showed the highest linear sintering shrinkage. CONCLUSION: Within the limitations of this study, the density difference of the presintered zirconia block did not affect the mechanical properties of the sintered zirconia block, but affected the linear sintering shrinkage of the zirconia block.

Endogenous angiotensin II modulates nNOS expression in renovascular hypertension

Nitric oxide (NO) influences renal blood flow mainly as a result of neuronal nitric oxide synthase (nNOS). Nevertheless, it is unclear how nNOS expression is modulated by endogenous angiotensin II, an inhibitor of NO function. We tested the hypothesis that the angiotensin II AT1 receptor and oxidative stress mediated by NADPH oxidase contribute to the modulation of renal nNOS expression in two-kidney, one-clip (2K1C) hypertensive rats. Experiments were performed on male Wistar rats (150 to 170 g body weight) divided into 2K1C (N = 19) and sham-operated (N = 19) groups. nNOS expression in kidneys of 2K1C hypertensive rats (N = 9) was compared by Western blotting to that of 2K1C rats treated with low doses of the AT1 antagonist losartan (10 mg·kg-1·day-1; N = 5) or the superoxide scavenger tempol (0.2 mmol·kg-1·day-1; N = 5), which still remain hypertensive. After 28 days, nNOS expression was significantly increased by 1.7-fold in the clipped kidneys of 2K1C rats and by 3-fold in the non-clipped kidneys of 2K1C rats compared with sham rats, but was normalized by losartan. With tempol treatment, nNOS expression increased 2-fold in the clipped kidneys and 1.4-fold in the non-clipped kidneys compared with sham rats. The changes in nNOS expression were not followed by changes in the enzyme activity, as measured indirectly by the cGMP method. In conclusion, AT1 receptors and oxidative stress seem to be primary stimuli for increased nNOS expression, but this up-regulation does not result in higher enzyme activity.

Oxidized Low-density Lipoprotein- and Lysophosphatidylcholine-induced Ca2+ Mobilization in Human Endothelial Cells

The effects of oxidized low-density lipoprotein (OxLDL) and its major lipid constituent lysophosphatidylcholine (LPC) on Ca2+ entry were investigated in cultured human umbilical endothelial cells (HUVECs) using fura-2 fluorescence and patch-clamp methods. OxLDL or LPC increased intracellular Ca2+ concentration ([Ca2+]i), and the increase of [Ca2+]i by OxLDL or by LPC was inhibited by La3+ or heparin. LPC failed to increase [Ca2+]i in the presence of an antioxidant tempol. In addition, store-operated Ca2+ entry (SOC), which was evoked by intracellular Ca2+ store depletion in Ca2+-free solution using the sarcoplasmic reticulum Ca2+ pump blocker, 2, 5-di-t-butyl-1, 4-benzohydroquinone (BHQ), was further enhanced by OxLDL or by LPC. Increased SOC by OxLDL or by LPC was inhibited by U73122. In voltage-clamped cells, OxLDL or LPC increased [Ca2+]i and simultaneously activated non-selective cation (NSC) currents. LPC-induced NSC currents were inhibited by 2-APB, La3+ or U73122, and NSC currents were not activated by LPC in the presence of tempol. Furthermore, in voltage-clamped HUVECs, OxLDL enhanced SOC and evoked outward currents simultaneously. Clamping intracellular Ca2+ to 1 micrometer activated large-conductance Ca2+-activated K+ (BKCa) current spontaneously, and this activated BKCa current was further enhanced by OxLDL or by LPC. From these results, we concluded that OxLDL or its main component LPC activates Ca2+-permeable Ca2+-activated NSC current and BKCa current simultaneously, thereby increasing SOC.

Preventing Extracellular Diffusion of Trigeminal Nitric Oxide Enhances Formalin-induced Orofacial Pain

Nitric oxide (NO), a diffusible gas, is produced in the central nervous system, including the spinal cord dorsal horn and the trigeminal nucleus, the first central areas processing nociceptive information from periphery. In the spinal cord, it has been demonstrated that NO acts as pronociceptive or antinociceptive mediators, apparently in a concentration-dependent manner. However, the central role of NO in the trigeminal nucleus remains uncertain in support of processing the orofacial nociception. Thus, we here investigated the central role of NO in formalin (3%)-induced orofacial pain in rats by administering membrane-permeable or -impermeable inhibitors, relating to the NO signaling pathways, into intracisternal space. The intracisternal pretreatments with the NO synthase inhibitor L-NAME, the NO-sensitive guanylate cyclase inhibitor ODQ, and the protein kinase C inhibitor GF109203X, all of which are permeable to the cell membrane, significantly reduced the formalin-induced pain, whereas the membrane-impermeable NO scavenger PTIO significantly enhanced it, compared to vehicle controls. These data suggest that an overall effect of NO production in the trigeminal nucleus is pronociceptive, but NO extracellularly diffused out of its producing neurons would have an antinociceptive action.

TEMPOL, a membrane-permeable radical scavenger, ameliorates lipopolysaccharide-induced acute lung injury in mice: a key role for superoxide anion

Acute lung injury [ALl] or acute respiratory distress syndrome is a serious clinical problem with high mortality. Oxidative stress was found to play a major role in mediating lung injury and antioxidants have been shown to be effective in attenuating ALI. In this study, we determine the effects of tempol, a membrane-permeable radical scavenger, in lipopolysaccharide [LPS] induced ALl and the underlying mechanism. ALl was induced by intraperitoneal injection of LPS [lmglkg] and mice were treated with tempol 30 mm before injection of LPS. One hour later, bronchoalveolar lavage fluid [BALF] was collected and subjected to estimation of total and differential cell counts as svell as the proinflammatory cytokines; tumor necrosis factor-alpha [TNF-alpha], interleukin-1beta [IL-1beta] and interferon-gamma [IFN-gamma]. Lung tissue damage was confirmed by histopathological changes and by immunohistochemical analysis of myeloperoxidase [MPO]. Moreover, lipid peroxidation, reduced glutathione [GSH] and nitric oxide [NO] were investigated in the lung tissue. Pretreatment with tempol produced significant attenuation of LPS-induced lung injury as well as inhibition of LPS mediated increase in MPO immunostaining, MDA and NO levels in lung tissue. Elevated cytokines levels in both BALF and lung tissue homogenates of ALl mice were significantly decreased after administration of tempol. These findings confirmed significant protection by tempol against LPS-induced acute lung injury and that superoxide anion scavenging appears to be a potential target for new potential therapy in pulmonary disorders

Anti-leishmanial and structure-activity relationship of ring substituted 3-phenyl-1-(1, 4-di-N-oxide quinoxalin-2-yl)-2-propen-1-one derivatives

A series of ring substituted 3-phenyl-1-(1,4-di-N-oxide quinoxalin-2-yl)-2-propen-1-one derivatives were synthesized and tested for in vitro leishmanicidal activity against amastigotes of Leishmania amazonensis in axenical cultures and murine infected macrophages. Structure-activity relationships demonstrated the importance of a radical methoxy at position R3', R4' and R5'. (2E)-3-(3,4,5-trimethoxy-phenyl)-1-(3,6,7-trimethyl-1,4-dioxy-quinoxalin-2-yl)-propenone was the most active. Cytotoxicity on macrophages revealed that this product was almost six times more active than toxic.