Observation of the Exotic 0_{2}

We report here the first observation of the 0_{2}^{+} state of ^{8}He, which has been predicted to feature the condensatelike α+^{2}n+^{2}n cluster structure. We show that this state is characterized by a spin parity of 0^{+}, a large isoscalar monopole transition strength, and the emission of a strongly correlated neutron pair, in line with theoretical predictions. Our finding is further supported by the state-of-the-art microscopic α+4n model calculations. The present results may lead to new insights into clustering in neutron-rich nuclear systems and the pair correlation and condensation in quantum many-body systems under strong interactions.

Positive-Parity Linear-Chain Molecular Band in

An inelastic excitation and cluster-decay experiment ^{2}H(^{16}C,^{4}He+^{12}Be or ^{6}He+^{10}Be)^{2}H was carried out to investigate the linear-chain clustering structure in neutron-rich ^{16}C. For the first time, decay paths from the ^{16}C resonances to various states of the final nuclei were determined, thanks to the well-resolved Q-value spectra obtained from the threefold coincident measurement. The close-threshold resonance at 16.5 MeV is assigned as the J^{π}=0^{+} band head of the predicted positive-parity linear-chain molecular band with (3/2_{π}^{-})^{2}(1/2_{σ}^{-})^{2} configuration, according to the associated angular correlation and decay analysis. Other members of this band were found at 17.3, 19.4, and 21.6 MeV based on their selective decay properties, being consistent with the theoretical predictions. Another intriguing high-lying state was observed at 27.2 MeV which decays almost exclusively to ^{6}He+^{10}Be(∼6 MeV) final channel, corresponding well to another predicted linear-chain structure with the pure σ-bond configuration.

Is vertebroplasty a risk factor for subsequent vertebral fracture, meta-analysis of published evidence?

UNLABELLED: In our paper, we systemically retrieved the eligible study evaluating whether increased incidence of subsequent vertebral fracture is associated with vertebroplasty. Main effect sizes were vertebral fracture rates reported in terms of hazard ratio (HR) for time-to-event data or relative risk (RR) for dichotomous outcome. Our results do not support the hypothesis that vertebroplasty contributes to increased risk of subsequent vertebral fracture, neither adjacent nor total vertebral fracture. INTRODUCTION: Vertebroplasty has been implicated in significant changes in vertebral strength, vertebral shape, and consequently increased risk for subsequent vertebral fracture, especially the adjacent level. Here, we further tested the hypothesis whether new-onset vertebral fracture is a natural result of osteoporosis or consequence of cement augmentation. METHODS: Relevant literatures were retrieved using PubMed, Web of Knowledge, and Cochrane Central Register of Controlled Trials (CENTRAL), supplemented by a hand-search of the reference lists of selected articles. Eligible studies assessed whether increased morbidity of subsequent vertebral fracture is associated with vertebroplasty. Main effect sizes were vertebral fracture rates reported in terms of hazard ratio (HR) for time-to-event data or relative risk (RR) for dichotomous outcome. Random-effects model was used to account for clinical or methodological heterogeneity across studies. RESULTS: Thirteen studies with a number of 2,551 individuals (1,631 in vertebroplasty group and 920 in control group) were suitable for this meta-analysis. In trials that reported adjacent vertebral fracture as time-to-event data (two trials, n = 328), we found a similar incidence of vertebral fracture in percutaneous vertebroplasty (PVP) group compared to conservative therapy (HR 0.60, 95% confidence interval 0.29 to 1.26; P = 0.18). In trials that reported overall vertebral fracture as time-to-event data (three trials, n = 704), vertebroplasty was associated with a slightly increased but non-significant risk for vertebral fracture (HR 1.14, 95% confidence interval 0.65 to 2.00; P = 0.65). The outcome was further confirmed in the secondary meta-analysis of studies that reported vertebral fracture as dichotomous data. Subgroup analysis according to study design revealed no difference either. CONCLUSIONS: Our results do not support the hypothesis that vertebroplasty contributes to increased risk of subsequent vertebral fracture, neither adjacent nor total vertebral fracture. However, adequately designed randomized controlled trials are warranted to confirm the present findings.

Observation of enhanced monopole strength and clustering in (12)Be.

In a recent breakup-reaction experiment using a Be12 beam at 29 MeV/nucleon, the 0+ band head of the expected He4+He8 molecular rotation was clearly identified at about 10.3 MeV, from which a large monopole matrix element of 7.0±1.0 fm2 and a large cluster-decay width were determined for the first time. These findings support the picture of strong clustering in Be12, which has been a subject of intense investigations over the past decade. The results were obtained thanks to a specially arranged detection system around zero degrees, which is essential in determining the newly emphasized monopole strengths to signal the cluster formation in a nucleus.

[Experimental study on substance P in the regulation of degranulation of cultured murine mast cells].

Objective: To investigate the effect of interleukin-4 (IL-4) stimulation on the expression of FcεRⅠα and NK-1R on mature mast cells(MC) cultured and differentiated from mouse bone marrow stem cells, and then to study if these MC also respond to substance P (SP) both in FcεRⅠα and NK-1R dependent manners. Methods: Bone marrow cells were aseptically flushed from BALB/c mouse femurs into complete RPMI 1640, followed by culture with stem cell factor (SCF 100 µg/L), IL-3 (15 µg/L) and IL-4 (0, 10, 15, 20 and 25 µg/L, respectively). The culture medium was changed once a week. The morphological changes of culture cells were observed under inverted microscope. After 4 weeks culture, the cells were collected and appraised by toluidine blue staining and flow cytometry. The expressions of surface CD117, FcεRⅠα and NK-1R on these cells were detected by flow cytometry and Western blot. Bone marrow MC were activated with SP (0, 0.01, 0.1, 1.0 and 10 mg/L, respectively) for 30 min. The histamine released into the supernatant and stored in the protoplasm was quantified by enzyme linked immunosorbent assay (ELISA). The percentage of histamine release was calculated as a percent of total histamine content. Results: When different concentrations of IL-4 (0, 10, 15, 20, 25 µg/L)were added into RPMI 1640, the positive rates of CD117 on MC surface were expressed as (94.8±1.3)%, (95.7±2.5)%, (94.1±1.3)%, (96.6±1.0)%, and (96.6±1.1)%, respectively, and there was no significant difference among these groups (F=8.51, P>0.05). The positive rates of FcεRⅠα were expressed as (81.5±2.6)%, (84.2±1.8)%, (91.8±2.0)%, (91.6±1.6)%, and (93.0±2.6)%, respectively, and there was statistically increasing among these groups (F=15.76, P<0.05). Then MC were activated by SP (0, 0.01, 0.1, 1.0, 10 mg/L), histamine from 20 µg/L IL-4 group were released (20.08±1.50)%, (32.76±2.99)%, (42.90±3.36)%、(50.21±1.29)%, (56.10±3.60)%, as similar as from 0 µg/L IL-4 were (19.37±2.02), (19.50±1.50), (21.77±1.91), (32.00±2.50), (33.56±1.25), there was significantly different when compared with each other (all P<0.05). Bone marrow MC were shown to have the highest expression of FcεRⅠα and NK-1R in culture of 20 µg/L IL-4 by the detection of Western blot, meanwhile these MC could be activated to degranulate by a lower concentration of SP (0.01 mg/L), with the release rate of histamine from MC showing a positive correlation with SP concentrations. On the other hand, MC with high expression of FcεRⅠα and little expression of NK-1R cultured with 0 µg/L IL-4, could also be activated by a much higher concentration of SP (1.0 mg/L). Conclusions: Bone marrow mast cells were shown to be successfully differentiated and to express NK-1R and FcεRⅠα upon co-culture with SCF and IL-3 or SCF, IL-3 and IL-4.When IL-4 was added into RPMI 1640, bone marrow MC could highly produce FcεRⅠα and NK-1R, thus building a better model of MC degranulation regulated by SP. And SP-controlled MC degranulation may be mediated through both FcεRⅠα (immunologically) and NK-1R (non-IgE mediated or non-immunologically) pathway.

Effect of cholesteryl ester on the distribution of fluorescent cholesterol analogues in triacylglycerol-rich emulsions.

Lipid emulsions consisting of a surface monolayer of phospholipid enclosing a core of neutral lipid (cholesteryl ester and/or triacylglycerol) are useful models of the lipid phase of lipoproteins. The physical state of the emulsion surface may determine the extent and nature of interaction of enzymes and lipid transfer proteins (e.g., lipoprotein lipase, cholesteryl ester transfer protein) with the particle. Unesterified cholesterol, which is a major determinant of the physical state of the surface phase, is able to partition between surface and core compartments. This report describes a fluorescence quenching method which determines the equilibrium distribution of a fluorescent cholesterol analogue (dehydroergosterol) between the surface and core compartments of triacylglycerol-rich emulsions. Quenching by iodide is used to distinguish a pool of unesterified cholesterol readily accessible to the aqueous phase. Quenching by 5-nitroxystearate identifies a pool of unesterified cholesterol in the phospholipid monolayer and the pool of unesterified cholesterol in the core compartment is found by difference. It is shown that the substitution of cholesteryl oleate for triolein in the core of the emulsion substantially increases the partition of unesterified cholesterol into the core compartment with a consequent depletion of unesterified cholesterol in the surface monolayer. The distribution of unesterified cholesterol between surface and core compartments is largely enthalpically driven.

Hydration and stability of sulfatide-containing phosphatidylethanolamine small unilamellar vesicles.

The effect of sulfatide on membrane hydration of 1, 2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) small unilamellar vesicles (SUVs) was investigated using steady-state and time-resolved fluorescence spectroscopy. The degree of hydration in the headgroup region of the bilayer lipids was assessed with the fluorescence lifetime of N-(5-dimethylaminonaphthalene-1-sulfonyl)dipalmitoylphosphatidylethan olamine along with the ratio of its fluorescence intensities measured in samples prepared either in D2O- or in H2O-based buffers. Similarly, hydration of acyl chains near the headgroup region and that close to the bilayer center were studied using 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene and 1-palmitoyl-2-[2-[4-(6-phenyl-trans-1,3, 5-hexatrienyl)phenyl]ethyl]carbonyl]-3-sn-phosphatidylcholine as probes. Increasing sulfatide concentration up to 30 mol% resulted in an increase in surface hydration and a decrease in interchain hydration. These were correlated with an increase in bilayer stability of the DOPE/sulfatide SUVs. Moreover, variation of pH was found to affect the hydration and stability of the bilayer vesicles. No further change in headgroup hydration and interchain hydration near the bilayer center was observed at sulfatide concentrations >/=30 mol%. At such high sulfatide concentrations, bilayer hydration and stability were no longer pH-sensitive. The effects of sulfatide on hydration and stability of DOPE bilayer vesicles are discussed by taking into account the electrostatic and geometrical properties of the sulfated galactosyl headgroups.

Stability and pH sensitivity of sulfatide-containing phosphatidylethanolamine small unilamellar vesicles.

The bilayer stabilization effect of sulfatide and the pH sensitivity of sulfatide-containing 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) small unilamellar vesicles were examined by light scattering and the release of entrapped calcein. At 30 mol% sulfatide, stable DOPE/sulfatide vesicles were formed at the physiological pH and their stability was preserved in the presence of human plasma. These vesicles were found to be pH-sensitive and became leaky at pH 6.0 or when there was a pH-gradient across the membrane bilayer. Under such conditions, the amount of calcein released after 24 h incubation at 37 degrees C was increased by one-fold compared to that found at pH 7.4. Our results suggest that the hydration and partial dehydration of the headgroup of sulfatide upon changing pH play an essential role in determining the pH sensitivity of DOPE/sulfatide vesicles, while the importance of the condensing effect of the glycolipid on membrane bilayer is less significant.

Caloric restriction prevents oxidative damage induced by the carcinogen clofibrate in mouse liver.

Long-term caloric restriction in rodents is known to decrease levels of oxidative damage, which may contribute to an 'anti-ageing' effect. We show here that a shorter period (10 months) of caloric restriction had only small effects on levels of oxidative DNA and protein damage in the livers of mice, but completely attenuated increased oxidative damage caused by the carcinogen clofibrate. Since clofibrate is thought to exert its actions by increasing oxidative damage, our data suggest that 10 months of caloric restriction can increase the resistance of tissues to agents inducing oxidative stress. This may be an important factor in explaining how caloric restriction decreases cancer incidence.

Mechanism of clofibrate hepatotoxicity: mitochondrial damage and oxidative stress in hepatocytes.

Peroxisome proliferators have been found to induce hepatocarcinogenesis in rodents, and may cause mitochondrial damage. Consistent with this, clofibrate increased hepatic mitochondrial oxidative DNA and protein damage in mice. The present investigation aimed to study the mechanism by which this might occur by examining the effect of clofibrate on freshly isolated mouse liver mitochondria and a cultured hepatocyte cell line, AML-12. Mitochondrial membrane potential (Delta Psi(m)) was determined by using the fluorescent dye 5,5',6,6'-tetrachloro-1,1', 3,3'-tetraethyl-benzimidazolylcarbocyanine iodide (JC-1) and tetramethylrhodamine methyl ester (TMRM). Application of clofibrate at concentrations greater than 0.3 mM rapidly collapsed the Delta Psi(m) both in liver cells and in isolated mitochondria. The loss of Delta Psi(m) occurred prior to cell death and appeared to involve the mitochondrial permeability transition (MPT), as revealed by calcein fluorescence studies and the protective effect of cyclosporin A (CsA) on the decrease in Delta Psi(m). Levels of reactive oxygen species (ROS) were measured with the fluorescent probes 5-(and-6)-carboxy-2',7'-dichlorofluorescein diacetate (DCFDA) and dihydrorhodamine 123 (DHR123). Treatment of the hepatocytes with clofibrate caused a significant increase in intracellular and mitochondrial ROS. Antioxidants such as vitamin C, deferoxamine, and catalase were able to protect the cells against the clofibrate-induced loss of viability, as was CsA, but to a lesser extent. These results suggest that one action of clofibrate might be to impair mitochondrial function, so stimulating formation of ROS, which eventually contribute to cell death.

Mitochondrial damage by the "pro-oxidant" peroxisomal proliferator clofibrate.

Clofibrate is a peroxisome proliferator that can cause hepatic cancer in rodents. It has been suggested that oxidative damage is involved in this hepatocarcinogenesis, although the data are conflicting. We confirmed that clofibrate causes oxidative damage in nuclei from the livers of mice treated with this substance, measured both as protein carbonyls and levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA. In addition, clofibrate also affects mitochondria, causing elevated levels of carbonyls and 8-OHdG, increased state 4 respiration and decreased adenosine triphosphatase (ATPase) activity. No evidence for clofibrate-induced lipid peroxidation in mitochondria was obtained. We propose that mitochondria may be a major target of injury and a source of oxidative stress in clofibrate-treated animals.

Antinociceptive activity of liposome-entrapped calcitonin by systemic administration in mice.

Porcine calcitonin (pCT) encapsulated in sulfatide-containing reverse-phase evaporation vesicles (REVs) was shown to induce long-lasting and dose-dependent antinociceptive effect by systemic injection in mice. Its antinociceptive activity is found to be dependent on the route of administration. In contrast, neither unencapsulated pCT nor pCT encapsulated in sulfatide-free REVs was effective. These results suggest that pCT entrapped in sulfatide-containing liposomes might be able to cross the blood-brain barrier (BBB) and to produce central antinociception in mice.

Bioactivity and mechanism of action of Lophozozymus pictor toxin.

The bioactivity of Lophozozymus pictor toxin (LPTX) and the possible mechanism of action of the purified toxin are described. LPTX is found to possess palytoxin-like bioactivities. Besides exhibiting cytotoxic and haemolytic properties, LPTX causes the release of K+ from erythrocytes and inhibits 2-[14C]deoxy-D-glucose uptake into HeLa cells. Although LPTX acts on HeLa cell and erythrocyte membranes, it does not interact with mitochondrial or liposomal membranes containing different phospholipid compositions. Ouabain, but not sphingomyelin, is able to prevent the toxic effects of LPTX. This antagonistic effect of ouabain on LPTX suggests that the toxin might mediate its toxic effects via the membrane Na+/K(+)-ATPase but not through interaction with membrane lipids.

Effect of ionic strength on the transfer of 1-pyrenemethyl-3 beta-hydroxy-22,23-bisnor-5-cholenate between bilayer vesicles containing phosphatidylserine.

The influence of ionic strength or the concentration of K+ ([K+]) of the aqueous phase on the spontaneous transfer of cholesterol between negatively charged bilayer vesicles composed of dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylserine (DPPS) (1:1, mole:mole) was studied using a pyrene-labelled cholesterol analogue, 1-pyrenemethyl-3 beta-hydroxy-22,23-bisnor-5-cholenate (PMC), as the probe. The decrease in PMC excimer fluorescence was best fitted to a bi-exponential function. Increasing [K+] from 0.1 M to 0.3 M had little effect on the shorter half-time (1.4 +/- 0.2 min) but increased the longer half-time from 16.3 +/- 1.9 min to 26.7 +/- 2.1 min. Fluorescence quenching and titration of an interface-located fluorophore, 1-anilinonaphthalene-8-sulfonic acid (ANS) revealed an increase in interfacial hydrophobicity upon increasing in ionic strength. The physical state of the acyl chains was not affected by ionic strength as indicated by a constant PMC excimer:monomer fluorescence intensity ratio. However, an increase in enthalpy change of the lipid phase transition from 15.7 kJ/mol ([K+] = 0.1 M) to 21.3 kJ/mol ([K+] = 0.3 M), together with a slight increase in the transition temperature, implies that interactions between adjacent molecules in the charged lipid bilayer vesicles became stronger at higher ionic strength. Our results suggest that the van der Waals attraction between PMC and phospholipid molecules could be affected by conformation changes in the charged head group region brought about by changes of ionic strength in the aqueous phase, with consequent effects on the desorption of cholesterol from the bilayer surface.

Steady-state fluorescence quenching for detecting acyl chain interdigitation in phosphatidylcholine vesicles.

In the present study we have demonstrated the detection of the transition of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) multilamellar vesicles from the noninterdigitated gel to the fully interdigitated gel phase in the presence of ethanol or ethylene glycol (EG) using the method of fluorescence quenching. This method is based on the change of accessibility of 2-(12-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl)amino)dodecanoyl-1-hexadecanoyl-sn-glycero-3- phosphatidyl-choline (NBD-PC), a membrane-buried fluorophore, to iodide, a quencher in the aqueous solution, during the phase transition. It is found that accessible fluorophore appears to increase at ethanol and EG concentrations known for inducing DPPC interdigitation. This increase in accessibility is either due to the relocation of the fluorescent moiety closer to the lipid-water interface or an increase in the ability of the quencher to penetrate into the loosely packed headgroup region of the interdigitated domain or both. Our results suggest the coexistence of interdigitated and noninterdigitated phases in the phospholipid vesicles and the method of fluorescence quenching might be useful in quantitating the percentage of phospholipids which are interdigitated.

Studies on lipid oxidation in fish phospholipid liposomes.

Fish phospholipid liposomes were prepared and used as an artificial membrane system to study factors influencing lipid oxidation. The extent of lipid oxidation was indexed by measuring the amount of thiobarbituric acid reactive substances (TBARS) produced. Fe2+, Fe3+, and Cu2+ were potent prooxidants in catalysing lipid oxidation. These metal ions induced lipid oxidation in a dose dependent manner. However, Zn2+, Ni2+, and Mn2+ did not significantly (p > 0.05) affect lipid oxidation at all the concentrations (1, 10, or 100 microM) studied. Morin, luteolin (flavonoids), butein (chalcone), tannic acid, ellagic acid (polyphenols), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) (synthetic antioxidants) were potent antioxidants (producing < 50% TBARS compared to control) of Fe(2+)-catalyzed lipid oxidation. Morin, luteolin, and butein possess two hydroxyl substituents, a C4 ketone structure and a 2-3 double bond, all of which contributed to their antioxidative potential. Fe2+ caused some losses of polyunsaturated fatty acids (PUFA), whereas tannic acid protected the oxidation of several of the PUFA including C 16:1 (Palmitoleic acid), C 18:3 (Linolenic acid), C 20:4 (Arachidonic acid), C 20:5 (Eicosapentaenoic acid), and C 22:6 (Docosahexaenoic acid).

[Observation on the distribution of [14C] AT-1902 in mice].

Distribution of [14C] AT-1902 in mice was studied by means of whole body autoradiography. After [14C] AT-1902 was injected im to mice, radioactivity was rapidly taken up by various organs. The highest radioactivity was found in kidneys, then the liver, lung, tumor and skin etc. Lowest radioactivity was found in brain. It is suggested that [14C] AT-1902 may be excreted through the gastrointestinal tract and kidneys.

[Involvement of the biliary duct in patient with acute icteric hepatitis].

The biliary duct system was studied in 850 patients with acute icteric hepatitis. Acute inflammation of the biliary duct was found in 50.94% of all cases, and in most patients, the damage of the hepatic cells and the inflammatory process in the biliary duct system recovered synchronously. In the remaining 7% of the cases, the biliary duct inflammation underwent chronic process. At acute stage, extrahepatic bile duct obstruction was caused by edema, mucus emboli, and bile sludge in 9.18 of all cases, and surgical drainage of the common bile duct was performed in 1.4% of the cases. Using Victoria Blue method, HBsAg was detected in tissues of both extra-and intrahepatic bile duct system, and the bile was also found to contain HBsAg by means of ELISA method. The authors came to the conclusion that hepatitis virus causes damage to the biliary duct system as well as the liver cells.

[Surgical results of various injuries related to central slip in extensor tendon of the hand].

In this article the results of surgical repair in 41 cases with different degrees of the central tendon band injuries of hand were reported and the results were compared for different kinds of operation. In this series all patients with degree I injury (3 cases) achieved excellent result by direct repairing disrupted tendons. 25 cases with degree II injury were repaired using three different procedures, among which the method of splitting lateral bands with cross suture yielded better result. However, only 7 patients (47%) reached excellent and good result, The reason for that is due to attention paid insufficiently to key problems during operation. For degree III injury only 5 cases out of 13 attained excellent and good result by transplantation of free tendons. The main cause for that failure is that the operator misplaced the crossing point of the tendons.

A novel sequence-based coa genotyping method to discriminate nosocomial methicillin-resistant Staphylococcus aureus isolates.

AIM: To evaluate a novel sequence-based coa typing method in classification for nosocomial methicillin-resistant Staphylococcus aureus. METHOD: D1 and D2 regions of coa gene were used to discriminate methicillin-resistant Staphylococcus aureus and compared with other classical sequence-based methods with discriminate power. RESULTS: All MRSA isolates were divided into 11 types and about 20 subtypes with coa typing method here. The discriminate power of this coa typing method was better than MLST or spa method. CONCLUSION: It was demonstrated that this coa method is a simple, rapid, and effective technique applicable for outbreak or local nosocomial MRSA investigations in the future.