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.
Cyclic N-Oxides ; Zirconium

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.
Cardiopulmonary Resuscitation ; Cyclic N-Oxides ; Hemodynamics ; Humans ; Manikins ; Music ; Outcome Assessment (Health Care) ; Quality Improvement ; Students, Medical ; Survival Rate ; Thorax

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.
Cyclic N-Oxides ; Estrogen Receptor alpha ; Estrogens ; Genetic Variation ; Genotype ; Humans ; Introns ; Polymorphism, Single Nucleotide ; Puberty ; Reference Values

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.
Cyclic N-Oxides ; Estrogen Receptor alpha ; Estrogens ; Genetic Variation ; Genotype ; Humans ; Introns ; Polymorphism, Single Nucleotide ; Puberty ; Reference Values

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.
Animals ; Antioxidants ; pharmacology ; Blood Pressure ; Cyclic N-Oxides ; pharmacology ; Denervation ; Electric Stimulation ; Hypertension ; physiopathology ; Kidney ; innervation ; Oxidative Stress ; Rats ; Renin-Angiotensin System ; Spin Labels ; Sympathetic Nervous System ; physiology

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.
Animals ; Butyrates ; Cyclic N-Oxides ; Embryonic Structures ; Hand ; Imidazoles ; Neurites ; Neurons ; Nitric Oxide ; Nitric Oxide Synthase ; PC12 Cells ; Rats ; RNA, Messenger

AIMTo investigate the chemical constituents of the bulbs of Fritillaria wabuensia.

METHODSChromatography techniques were used to isolate the chemical constituents. EI-MS, 1HNMR, 13 CNMR and DEPT were used to determine the structures of the isolated constituents.

RESULTSThree alkaloids were isolated from the bulbs of Fritillaria wabuensia, and were identified as imperialine (I), imperialine-beta-N-oxside (II), isoverticine-beta-N-oxide (III).

CONCLUSIONIsoverticine-beta-N-oxide was isolated from the bulbs of Fritillaria wabuensia for the first time. Isoverticine-beta-N-oxide is a new alkaloid.

Cevanes ; chemistry ; isolation & purification ; Cyclic N-Oxides ; chemistry ; isolation & purification ; Fritillaria ; chemistry ; Molecular Structure ; Plants, Medicinal ; chemistry ; Triterpenes ; chemistry ; isolation & purification

This article describes the preparation of the N-tert-butyl-alpha-phenylnitrone (PBN) liposomes and their related characteristics. The PBN liposomes were prepared by film dispersion-supersonic method and the formula of liposomes was optimized by orthogonal uniform design. RP-HPLC was used to qualify the amount of PBN that entered into the hepatoma cells. Necrosis rate was also investigated by fluorescence activated cell sorter (FACS) after PBN liposomes transfection. Result showed that the mean particle size, entrapment efficiency, and polydispersity of the resulting PBN-liposome were 137.5 nm, 71.52% and 0.286, respectively. PBN liposomes can enter into the tumor cell stably and they have higher affinity to hepatoma cell compared with free PBN resulting in a higher necrosis rate after transfection. These results provide a potential method for early diagnosis and treatment of cancer using specific spin trapping probe targeting tumor cells.
Carcinoma, Hepatocellular ; pathology ; Cyclic N-Oxides ; chemistry ; Electron Spin Resonance Spectroscopy ; Humans ; Nanoparticles ; chemistry ; Spin Labels ; Spin Trapping ; methods ; Tumor Cells, Cultured

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.
Constriction ; Cyclic N-Oxides ; Endothelial Cells ; Estrenes ; Fluorescence ; Fura-2 ; Heparin ; Humans ; Lipoproteins ; Lipoproteins, LDL ; Lysophosphatidylcholines ; Pyrrolidinones ; Sarcoplasmic Reticulum ; Spin Labels

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.
Animals ; Antineoplastic Agents ; Antioxidants ; Apoptosis ; Cell Line, Tumor ; Cell Proliferation ; Cisplatin ; Cyclic N-Oxides ; pharmacology ; Drug Resistance, Neoplasm ; Humans ; Mice ; Spin Labels