Quercetin inhibits LPS-induced delay in spontaneous apoptosis and activation of neutrophils

OBJECTIVE

To investigate the effects of quercetin, an herbal flavonoid, on LPS-induced delay in spontaneous apoptosis, adhesion molecules (CD62L, CD11b/CD18) expression of neutrophils, and superoxide (O(2)(-)) generation by LPS-primed fMLP-induced human neutrophils.

METHODS

Neutrophils were incubated in the presence or absence of lipopolysaccharide (LPS) at a final concentration of 1 microg/ml for 24 hours. Some wells with neutrophils were pre-treated with quecetin at the final concentration ranging from 0-100 microM for 30 min and then 1 microg/ml LPS was added into the cultures for 24 hours. The apoptosis of neutrophils was evaluated by flowcytometry analysis of propidum iodide (PI)-staining of the nuclei and annexin V staining of phosphatidylserine (PS) in the cell membrane. Agarose gel electrophoresis of low molecular weight DNA was performed to analyze DNA fragmentation. The effects of quercetin on adhesion molecules were detected by using flowcytometry analysis. The generation of O(2) (-) by LPS-primed fMLP-induced neutrophils was determined by reduced cytochrome c assay.

RESULTS

LPS markedly inhibited the spontaneous apoptosis of neutrophils, but the inhibitory effect was abrogated after the pre-treatment of neutrophils with quercetin (approximately 40 microM) for 30 min. Quercetin (40 microM) also prevented LPS-induced down-regulation of CD62L expression, up-regulation of CD11b/CD18 expression, and O(2) (-) generation by fMLP-induced neutrophils.

CONCLUSION

As one of the pro-inflammatory factors, LPS aggravates inflammation through priming neutrophils to synthesize/release cytotoxic contents and prolonging functional lifespan of neutrophils by delaying the spontaneous apoptosis. Thus, our data suggest to us that quercetin might decrease the susceptibility of neutrophils to pro-inflammatory factors (e. g. LPS), which could partially explain the anti-inflammatory mechanisms of quercetin.

Human cystic echinococcosis in two Mongolian communities in Hobukesar (China) and Bulgan (Mongolia)

In order to investigate the prevalence of human cystic echinococcosis (CE) in traditional Mongolian communities in western Mongolia and Xinjiang (northwest China), studies were carried out between 1995 and 2000, on two ethnically identical populations in Hobukesar (China) and Bulgan (Mongolia). The prevalence of human hepatic CE in the two communities was significantly different. In Hobukesar, human CE prevalence by ultrasound was 2.7% (49/1844), while in Bulgan it was 0.2% (4/1609) (P<0.001). Dog surveys showed that coproantigen-positive rates or dog necropsy positives were similar in both communities (35.0% in Hobukesar and 35.7% in Bulgan). Comparing possible risk factors, there appeared to be some significant differences between the two communities, which might contribute to the observed difference in CE prevalence. These included: the proportion of herdsman or farmers recorded; the proportions of dog ownership and livestock ownership; and the proportion of families practising home slaughter. The presence of a Russian dog-dosing programme up to the mid-1980s may explain the lower prevalence of human CE in the Bulgan population; no similar programme operated in the China-administered Hobukesar community.

Contrast-enhanced MRI of the menisci of the knee using ultrashort echo time (UTE) pulse sequences: imaging of the red and white zones

The objective of this study was to demonstrate the red and white zones of the meniscus of the knee using MRI. Ultrashort echo time (UTE) pulse sequences with an initial TE of 0.08 ms and later echoes at 5.95 ms, 11.08 ms and 17.70 ms were used to image the meniscus of the knee in two normal subjects before and after intravenous administration of gadodiamide. Difference images were formed by subtraction of later echo images from the first. The difference images showed obvious enhancement in an area consistent in location and dimensions with the red zone of the meniscus. Regions of interest placed within this area, central to it (corresponding to the white zone), and peripheral to it (corresponding to perimeniscal tissue) all showed increases in signal intensity after intravenous contrast administration. The greatest change in signal intensity in these regions of interest was seen with the shortest TE and in perimeniscal tissue on the original images. The increase in signal intensity was greatest in the red zone on the difference images. Using UTE pulse sequences and difference images derived from them, it is possible to visualize enhancement selectively in the red zone of the meniscus. Less obvious but significant changes in signal intensity were also present in the white zone.

Applicability of CORVUS pencil beam model and scatter dose model for intensity modulated neutron therapy

Intensity modulated neutron radiotherapy (IMNRT) is currently being investigated as a mechanism to improve dose conformality in neutron radiotherapy, thereby minimizing normal tissue toxicity. This study investigates the applicability of two different dose calculation algorithms for IMNRT, a commercial system which utilizes a finite size pencil beam (FSPB) model, and an in-house planning system which uses a differential scatter air ratio (DSAR) method. Calculated dose distributions were compared with measured profiles for validation purposes. The beam-profiles matched to within +/-3% in the central region of the field. The 80-20% penumbra width as measured using an ionization chamber varied as 0.6 cm and 1.0 cm for 3 x 3 and 10 x 10 cm2 profile at a depth of 2.5 cm. The FSPB model fitted the data to a penumbra width of 0.1 cm for both 3 x 3 and 10 x 10 cm2 profiles. These results indicate that the commercial system needs further investigation. However, the in-house planning system has been validated for small irregular fields for IMNRT to an accuracy of +/-5%. Absolute dose measurements agreed with the calculated doses to within +/-3%.

Anthropogenic disturbance promotes hybridization between Banksia species by altering their biology

Putative hybrids between Banksia hookeriana and B. prionotes were identified among 12 of 106 populations of B. hookeriana located at or near anthropogenically disturbed sites, mainly roadways, but none in 156 undisturbed populations. Morphometrics and AFLP markers confirmed that a hybrid swarm existed in a selected disturbed habitat, whereas no intermediates were present where the two species co-occurred in undisturbed vegetation. Individuals of both species in disturbed habitats at 12 sites were more vigorous, with greater size and more flower heads than their counterparts in undisturbed vegetation. These more fecund plants also showed a shift in season and duration of flowering. By promoting earlier flowering of B. hookeriana plants and prolonging flowering of B. prionotes, anthropogenic disturbance broke the phenological barrier between these two species. We conclude that anthropogenic disturbance promotes hybridization through increasing opportunities for gene flow by reducing interpopulation separation, increasing gamete production and, especially, promoting coflowering.

Quantum phase transition in quasi-one-dimensional BaRu6O12

We report the first systematic study of the electrical transport and magnetic properties of BaRu6O12, which has a quasi-one-dimensional (quasi-1D) hollandite structure. We show that BaRu6O12 is quasi-1D electronically as well. Its physical properties were found to be extremely sensitive to disorder. Furthermore, a transition from being metallic with a resistance drop around 2 K to being weakly insulating as the applied magnetic field was increased was also found. We propose that these two features are related to the possible presence of a quantum phase transition in this material system.

Linear and non-linear methods for automatic seizure detection in scalp electro-encephalogram recordings

The electro-encephalogram is a time-varying signal that measures electrical activity in the brain. A conceptually intuitive non-linear technique, multi-dimensional probability evolution (MDPE), is introduced. It is based on the time evolution of the probability density function within a multi-dimensional state space. A synthetic recording is employed to illustrate why MDPE is capable of detecting changes in the underlying dynamics that are invisible to linear statistics. If a non-linear statistic cannot outperform a simple linear statistic such as variance, then there is no reason to advocate its use. Both variance and MDPE were able to detect the seizure in each of the ten scalp EEG recordings investigated. Although MDPE produced fewer false positives, there is no firm evidence to suggest that MDPE, or any other non-linear statistic considered, outperforms variance-based methods at identifying seizures.

Branched crystal morphology of linear polyethylene crystallized in a two-dimensional diffusion-controlled growth field

The branched crystal morphology of linear polyethylene formed at various temperatures from thin films has been studied by atomic-force microscopy (AFM), transmission electron microscopy (TEM), electron diffraction (ED) pattern and polymer decoration technique. Two types of branched patterns, i.e. dendrite and seaweed patterns, have been visualized. The fractal dimension d(f) = 1.65 of both dendrite and some of seaweed patterns was obtained by using the box-counting method, although most of the seaweed patterns are compact. Selected-area ED patterns indicate that the fold stems tilt about 34.5( degrees ) around the b-axis and polymer decoration patterns show that the chain folding direction and regularity in two (200) regions are quite different from each other. Because of chain tilting, branched crystals show three striking features: 1) the lamella-like branches show two (200) regions with different thickness; 2) the crystals usually bend towards the thin region; 3) the thick region grows faster by developing branches, thus branches usually occur outside the thick region. The branched patterns show a characteristic width w, which gives a linear relationship with the crystallization temperature on a semilogarithmic plot.

Macroscopic and roentgenographic anatomy of the skull of the ferret (Mustela putorius furo)

Normal macroscopic and roentgenographic features of the skull of the ferret (Mustela putorius furo) were examined and described. Data were based on a sample of 100 (50 male and 50 female) adult ferrets of known body weight and age. The skull was described macroscopically according to six standard views, i.e. dorsal, lateral, ventral, caudal, cranial and midsagittal. The mandible was described separately. The roentgenographic characteristics of the ferret skull were demonstrated only in lateral and dorsoventral projections. Furthermore, the skull length and width as well as the minimum frontal width were measured, and skull indices were derived from relevant measurements. Sexual dimorphism was examined both morphologically and craniometrically. Besides the common features of a carnivore skull, the ferret skull is relatively elongated and flat with a short facial region. The skulls of adult male ferrets are about 17% longer and 22% wider than those of the females. Significant sexual dimorphism also exists regarding certain skull indices. The general features and some dimensional parameters of the adult ferret skull support the contention that the ferret would be an interesting and workable alternative animal model in craniofacial research.

(13)C NMR investigation of the superconductor MgCNi(3) up to 800 K

We report (13)C NMR characterization of the new superconductor MgCNi(3) [T. He et al., Nature (London) 411, 54 (2001)]. We found that both the uniform spin susceptibility and the spin fluctuations show a strong enhancement with decreasing temperature, and saturate below approximately 50 K and approximately 20 K, respectively. The nuclear spin-lattice relaxation rate 1/(13)T(1) exhibits typical behavior for isotropic s-wave superconductivity with a coherence peak below T(c) = 7.0 K that grows with decreasing magnetic field.

Similarity of an Aroclor-based and a full congener-based method in determining total PCBs and a modeling approach to estimate Aroclor speciation from congener-specific PCB data

Polychlorinated biphenyls (PCBs) have entered the environment in North America as Aroclor technical mixtures. Most methods used for the determination of total PCB levels in environmental samples visually match patterns of sample peaks to those in Aroclor standards. Concern over the accuracy of Aroclor-based measurements on compositionally modified samples coupled with advancements in analytical techniques have led to congener-specific PCB analysis. In this study, the PCB data from 27 tissue samples determined by an Aroclor-based method and a full congener method were compared in terms of total PCB concentration to assess the reliability of this Aroclor technique for total PCB determination. Our data show a strong correlation between the sum of Aroclors and the total PCBs obtained from the full congener determinations. We also developed a model using the compositional data from three Aroclors (1242, 1254, and 1260) to determine the amount of compositional alteration from original Aroclor patterns in environmental samples. Full congener data, from a variety of tissue types and trophic levels, examined using this method showed that compositional modification from original Aroclor patterns increases with trophic level, with the greatest modification observed in seal and killer whale samples. This result agrees both with expectation and with what has been found in other studies. Such techniques, which connect congener-specific PCB data to Aroclor contamination, may prove useful to investigations into environmental and metabolic fate and transfer processes.

Disturbances in hepatic cell-cycle regulation in mice with assembly-deficient keratins 8/18

Simple epithelial tissues such as liver and pancreas express keratins 8 (K8) and 18 (K18) as their major intermediate filament proteins. K8 and K18 null mice and transgenic mice that express mutant K18 (K18C) manifest several hepatocyte abnormalities and demonstrate that K8/18 are important in maintaining liver tissue and cell integrity, although other potential functions remain uncharacterized. Here, we report an additional abnormal liver phenotype, which is similar in K8 null, K18 null, and K18C mouse models. Liver histologic examination showed large polynuclear areas that lacked cell membranes, desmosomal structures, and filamentous actin. Similar, but less prominent, areas were observed in the pancreas. The parenchyma outside the polynuclear areas displayed irregular sinusoidal structures and markedly enlarged nuclei. Most K8 null hepatocytes were positive for the proliferating cell nuclear antigen (PCNA) with a doubled DNA content in comparison with the predominantly PCNA-negative wild-type hepatocytes. The distribution of the 14-3-3zeta protein was also altered in K8 null mice. Taken together, our results indicate that absence of keratin filaments causes disturbances in cell-cycle regulation, driving cells into the S-G2 phase and causing aberrant cytokinesis. These effects could stem from disturbed functions of K8/18-dependent cell-cycle regulators, such as the signaling integrator, 14-3-3.

[A comparison between the effects of albuterol and isoproterenol in bronchodilation test]

OBJECTIVE

To compare albuterol with isoproterenol as a bronchodilator in pulmonary function test and their value in the diagnosis and differential diagnosis of asthma.

METHODS

Two groups (59 patients with asthma and 37 patients with COPD) were included in this study, and the patients of each group were randomly divided into 2 subgroups. The patients in the 2 subgroups inspired the two drugs in a cross-over by odd or even days. The pulmonary functions were evaluated.

RESULTS

The changing rates of pulmonary functions induced by the two drugs in the two groups were positively correlated (P < 0.005), The changing rates of FEV1, MMEF, Raw, sGaw induced by albuterol were higher than the ones induced by isoproterenol in patients with asthma(P < 0.02), however the changing rates of FVC and PEF in asthma cases and all the above parameters in COPD cases were not significantly different between the two drugs(P > 0.10). The comparison of positive case number between asthma and COPD cases induced by both drugs showed significant difference(P < 0.005); especially, when the positive rate of sGaw induced by albuterol in asthma cases reached 98%, the positive rates in COPD cases was generally much lower.

CONCLUSION

Bronchodilation test is a valuable diagnostic method for asthma. In this study, albuterol was superior to isoproterenol. The most sensitive index in bronchodilation test was sGaw, then in order, FEV1(92%), MMEF and Raw; the FVC and PEF were relatively insensitive.

[The effect of leukotriene antagonist on the parameters of dose-response curve obtained after methacholine challenge test]

OBJECTIVE

To investigate the effect of leukotriene antagonist (zafirlucast) on the parameters of dose-response curve (DRC) obtained after methacholine challenge test.

METHODS

A therapy trial was conducted with the use of zafirlucast in 20 cases of cough variant asthma (CVA) and 20 cases of asthma. Placebo was used in 4 cases of CVA and 10 cases of asthma for comparison with the two therapy groups respectively. Before and after the zafirlucast treatment a series of parameters of DRC were obtained after the methacholine challenge test and were calculated. These included the response threshold (PC35sGaw), the dose-response slope (DRS), the ratio of the area under the curve to the logarithm of the maximal concentration (AUC/1 g[Cmax]), and the maximal response.

RESULTS

Zafirlucast significantly increased the PC35sGaw in the CVA and asthma groups. It conspicuously decreased all the parameters of DRS and AUC/1 g[Cmax] except for maximal response in the cases of CVA, and it had no significant effects on all the parameters of DRS and AUC/1 g[Cmax] except for PC35sGaw in the cases of asthma.

CONCLUSION

Short-term use of Zafirlucast in asthmatic patients could improve the parameters of dose-response curve obtained after the methacholine challenge test.

Reaction of metallotetraphenylporphyrins on hydroxyl-modified silver colloid and Ag2O colloid by surface-enhanced Raman scattering

This paper reports a novel reaction of metallotetraphenylporphyrins on hydroxyl-modified silver colloid and Ag2O colloid. Surface-enhanced Raman spectra of Ag(II) and Cu(II) complexes of tetraphenylporphyrin (TPP) adsorbed on the hydroxyl-modified Ag colloid and Ag2O colloid have been studied. The time-dependent SERS spectra of MTPP (M = Ag, Cu) on hydroxyl-modified Ag colloid were recorded and dramatic change on SERS spectra was observed. The final spectra were found to be strikingly different from the corresponding normal Raman spectra (NRS), with the appearance of new Raman bands at 1614. 1417, 947, 674 and 292 cm(-1). The UV-visible absorption spectrum of MTPP on hydroxyl-modified Ag colloid exhibits a broad shoulder near 460 nm. Similar spectral phenomena were also observed for AgTPP and CuTPP adsorbed on Ag2O colloid. The observed spectral alterations were ascribed to new species formation due to the irreducible oxidation of MTPP on the colloids.

Tibioperoneal (outflow lesion) angioplasty can be used as primary treatment in 235 patients with critical limb ischemia: five-year follow-up

BACKGROUND

In a prospective, nonrandomized, consecutive series of tibioperoneal vessel angioplasty (TPVA), critical limb ischemia (CLI) patients' data were analyzed with regard to immediate and follow-up success.

METHODS AND RESULTS

TPVA was successful in 270 of 284 critically ischemic limbs (95%), with 167 limbs (59%) requiring dilatation of 333 ipsilateral inflow obstructions to access and successfully dilate 486 of 529 (92%) tibioperoneal lesions. A clinical success (relief of rest pain or improvement of lower-extremity blood flow) was attained in 270 limbs at risk (95%). Clinical 5-year follow-up of 215 of 221 successful CLI patients (97%) with 266 successfully revascularized limbs revealed that bypass surgery occurred in 8% and significant amputations in 9% of limbs; 91% of the limbs were salvaged. The cohort's probability of survival was 56%: 58% for Fontaine class III and 33% for class IV patients. Class III compared with class IV patients had significantly (P<0.05) fewer surgical bypasses (3% versus 16%) and amputations: above-knee, 1% versus 4%; below-knee, 3% versus 12%; and transmetatarsal, <1% versus 21%.

CONCLUSIONS

TPVA, often in combination with inflow lesions, is an effective primary treatment for critical limb ischemia. The poor cumulative survival reflects the existence of severe comorbidities, which could potentially be affected by aggressive and effective cardiovascular diagnostic and therapeutic strategies.

[Measurement of the parameters of dose-response curve obtained after the methacholine challenge test]

OBJECTIVE

To investigate the clinical value in the measurement of parameters of the dose-response curve (DRC) obtained after the methacholine challenge test.

METHODS

Twenty-seven cases of cough variant asthma (CVA), 29 of mild asthma, 19 of moderate asthma, and 15 healthy volunteers underwent the methacholine challenge test. The dose-response curves were constructed. The following parameters were calculated: position (PC35sGaw), dose-response curve (DRS), ratio of the area under the curve to the logarithm of the maximal concentration (AUC/lg[Cmax]) and maximal response.

RESULTS

A plateau appeared in 11 cases among the healthy subjects, while a plateau appeared only in 2 cases of CVA and 2 of asthma. There were no significant differences among the asthmatic groups in the measurements of PC35sGaw and AUC/lg[Cmax] (geometric mean PC35sGaw: mild asthmatics = 0.369, moderate asthmatics = 0.251, cough variant asthmatics = 0.547), AUC/lg[Cmax] was significantly greater in the asthmatic groups than in the normal group [AUC/lg [Cmax](mean +/- s): mild asthmatics = 24.7 +/- 4.7, moderate asthmatics = 26.6 +/- 4.3, cough variant asthmatics = 25.6 +/- 3.7, normal subjects = 15.5 +/- 4.3, P < 0.01]. DRS of moderate asthmatics was significantly greater as compared with cough variant asthmatics (geometric mean DRS: mild asthmatics = 30.761, moderate asthma-tics = 59.020, cough variant asthmatics = 19.231, P < 0.05), but there was no difference between the other groups. PC35sGaw was negatively correlated with DRS (r = 0.866, P < 0.001) and with AUC/lg[Cmax] (r = 0.502, P < 0.001).

CONCLUSION

Four parameters of DRC obtained after the methacholine challenge represent airway sensitivity and reactivity respectively. The parameters of DRC of asthmatic patients are different from those of normal subjects. The sensitivity is related to the reactivity, but they are not completely parallel with each other.

TNF-alpha mediates SDF-1 alpha-induced NF-kappa B activation and cytotoxic effects in primary astrocytes

Stromal-derived cell factor-1 alpha (SDF-1 alpha; CXCL12) and its receptor, CXCR4, are constitutively expressed on neuroepithelial cells and are believed to be involved in both development and pathological processes, such as AIDS-associated neurologic disorders. Here, we demonstrate that SDF-1 alpha activates NF-kappa B, stimulates production of chemokines and cytokines, and induces cell death in primary astrocytes, effects that depend on ongoing secretion of TNF-alpha. SDF-1 alpha upregulated TNF-alpha mRNA and protein secretion, as well as TNF receptor 2 expression. TNF-alpha treatment mimicked SDF-1 alpha induction of NF-kappa B, IL-1 alpha/beta, and RANTES, as well as cell death; neutralizing antibodies against TNF-alpha opposed these responses. We also found that SDF-1 alpha activated Erk1 and Erk2 (Erk1/2) MAPK in a biphasic fashion. Early Erk1/2 activation was stimulated directly by SDF-1 alpha and late activation was mediated by TNF-alpha. PD98059 suppression of early Erk1/2 activation correlated with reduction of SDF-1 alpha-induced TNF-alpha expression. Late Erk1/2 activation was involved in TNF-alpha-stimulated NF-kappa B activation and cytokine induction. SDF-1 alpha was induced in reactive CXCR4-positive astrocytes near axotomized spinal cord motor neurons, consistent with autocrine SDF-1/CXCR4 signaling in these cells. We propose that these novel effects of SDF-1 alpha are relevant to the pathogenic and developmental roles of SDF-1 alpha in the CNS.

Giant anharmonicity and nonlinear electron-phonon coupling in MgB2: a combined first-principles calculation and neutron scattering study

First-principles calculations of the electronic band structure and lattice dynamics for the new superconductor MgB (2) are carried out and found to be in excellent agreement with our inelastic neutron scattering measurements. The numerical results reveal that the E(2g) in-plane boron phonons near the zone center are very anharmonic and strongly coupled to the planar B sigma bands near the Fermi level. This giant anharmonicity and nonlinear electron-phonon coupling is key to quantitatively explaining the observed high T(c) and boron isotope effect in MgB (2).

Ultraviolet irradiation blocks cellular responses to transforming growth factor-beta by down-regulating its type-II receptor and inducing Smad7

Transforming growth factor-beta (TGF-beta) is a multi-functional cytokine that regulates cell growth and differentiation. Cellular responses to TGF-beta are mediated through its cell surface receptor complex, which activates transcription factors Smad2 and Smad3. Here we report that UV irradiation of mink lung epithelial cells causes near complete inhibition of TGF-beta-induced Smad2/3-mediated gene expression. UV irradiation inhibited TGF-beta-induced phosphorylation of Smad2 and subsequent nuclear translocation and DNA binding of Smad2/3. Specific cell surface binding of TGF-beta was substantially reduced after UV irradiation. This loss of TGF-beta binding resulted from UV-induced down-regulation of TGF-beta type II receptor (T beta RII) mRNA and protein. UV irradiation significantly inhibited T beta RII promoter reporter constructs, indicating that UV reduction of T beta RII expression involved transcriptional repression. In contrast to its effects on T beta RII, UV irradiation rapidly induced Smad7 mRNA and protein. Smad7 is known to antagonize activation of Smad2/3 and thereby block TGF-beta-dependent gene expression. UV irradiation stimulated Smad7 promoter reporter constructs, indicating that increased Smad7 expression resulted, at least in part, from increased transcription. Overexpression of Smad7 protein to the level induced by UV irradiation inhibited TGF-beta-induced gene expression 30%. Maintaining T beta RII levels by overexpression of T beta RII prevented UV inhibition of TGF-beta responsiveness. Taken together, these data indicate that UV irradiation blocks cellular responsiveness to TGF-beta through two mechanisms that impair TGF-beta receptor function. The primary mechanism is down-regulation of T beta RII, and the secondary mechanism is induction of Smad7.

Safety of three toothbrushes

PURPOSE

To assess the oral soft tissue safety and tolerability of two electric toothbrushes, the Crest Spin Brush and Colgate ActiBrush, and one manual toothbrush, the Oral B 40.

MATERIALS AND METHODS

A total of 104 subjects were enrolled in this single center, randomized, examiner-blind parallel study over a 4-wk test period. Subjects were randomized to treatment and were instructed to brush in their normal manner, twice per day for 60 s. A detailed oral soft tissue examination and interview were conducted by a trained clinician at baseline, 3 days and 4 wks to assess clinical signs and symptoms associated with use of the toothbrushes.

RESULTS

Over the 4-wk period, a total of 19 subjects (18% of the study population) were observed for signs/symptoms. The adverse events were distributed across test groups with 12 subjects in the Oral B 40 group, 4 subjects in the Crest Spin Brush group, and 3 subjects in the Colgate ActiBrush group experiencing at least one adverse event. All adverse events were mild in severity indicating the general safety of all three toothbrushes. The most frequently encountered event was localized gingivitis. The Oral B 40 test group was observed with more adverse events when compared to the Crest Spin Brush and Colgate ActiBrush at 4 wks but not at 3 days. The proportion of subjects experiencing an adverse event in the Crest Spin Brush test group was similar to that of Colgate ActiBrush group. All three toothbrushes were generally well tolerated by subjects enrolled in the study with the Crest Spin Brush and Colgate ActiBrush being the best tolerated.

CLINICAL SIGNIFICANCE

The results of this study indicated that abnormal oral soft tissue findings were distributed among the treatment groups, indicating that daily use of an electric toothbrush is at least as safe as a manual toothbrush.

[The effects of quercetin and isorhamnetin on oxidative modification of VLDL induced by Cu2+]

OBJECTIVE

To observe the effects of quercetin(Que) and isorhamnetin (Iso) on the oxidative modification of very low density lipoprotein (VLDL).

METHODS

Human VLDL was prepared by one-step ultracentrifuge and oxidized by Cu2+ in vitro; Que and Iso in different concentrations were added to VLDL before incubation with Cu2+. The MDA, vitamin E contents and the activity of superoxide dismutase(SOD) in ox-VLDL were determined.

RESULTS

Compared with ox-VLDL group, Que and Iso decreased MDA production in a dependent concentration-manner, Que and Iso also elevated Vit E level and SOD activity markedly.

CONCLUSION

This experiment indicates that Que and Iso have similar inhibitory effects on the oxidative modification of VLDL.

High critical current density and enhanced irreversibility field in superconducting MgB2 thin films

The discovery of superconductivity at 39 K in magnesium diboride offers the possibility of a new class of low-cost, high-performance superconducting materials for magnets and electronic applications. This compound has twice the transition temperature of Nb3Sn and four times that of Nb-Ti alloy, and the vital prerequisite of strongly linked current flow has already been demonstrated. One possible drawback, however, is that the magnetic field at which superconductivity is destroyed is modest. Furthermore, the field which limits the range of practical applications-the irreversibility field H*(T)-is approximately 7 T at liquid helium temperature (4.2 K), significantly lower than about 10 T for Nb-Ti (ref. 6) and approximately 20 T for Nb3Sn (ref. 7). Here we show that MgB2 thin films that are alloyed with oxygen can exhibit a much steeper temperature dependence of H*(T) than is observed in bulk materials, yielding an H* value at 4.2 K greater than 14 T. In addition, very high critical current densities at 4.2 K are achieved: 1 MA cm-2 at 1 T and 105 A cm-2 at 10 T. These results demonstrate that MgB2 has potential for high-field superconducting applications.

Superconductivity in the non-oxide perovskite MgCNi3

The interplay of magnetic interactions, the dimensionality of the crystal structure and electronic correlations in producing superconductivity is one of the dominant themes in the study of the electronic properties of complex materials. Although magnetic interactions and two-dimensional structures were long thought to be detrimental to the formation of a superconducting state, they are actually common features of both the high transition-temperature (Tc) copper oxides and low-Tc material Sr2RuO4, where they appear to be essential contributors to the exotic electronic states of these materials. Here we report that the perovskite-structured compound MgCNi3 is superconducting with a critical temperature of 8 K. This material is the three-dimensional analogue of the LnNi2B2C family of superconductors, which have critical temperatures up to 16 K (ref. 2). The itinerant electrons in both families of materials arise from the partial filling of the nickel d-states, which generally leads to ferromagnetism as is the case in metallic Ni. The high relative proportion of Ni in MgCNi3 suggests that magnetic interactions are important, and the lower Tc of this three-dimensional compound-when compared to the LnNi2B2C family-contrasts with conventional ideas regarding the origins of superconductivity.

Pressure dependence of the superconducting transition temperature of magnesium diboride

We studied the pressure and temperature dependence of the electrical resistivity of the superconducting compound magnesium diboride (MgB(2)). The superconducting transition temperature decreases monotonically with pressure, being parabolic or linear, depending on samples. The rate of decrease under pressure is higher than in conventional superconductors. We discuss our results in terms of the semimetallic character of the electronic band structure of MgB(2).

Loss of superconductivity with the addition of Al to MgB2 and a structural transition in Mg1-x AlxB2

The basic magnetic and electronic properties of most binary compounds have been well known for decades. The recent discovery of superconductivity at 39 K in the simple binary ceramic compound magnesium diboride, MgB2, was therefore surprising. Indeed, this material has been known and structurally characterized since the mid 1950s (ref. 2), and is readily available from chemical suppliers (it is commonly used as a starting material for chemical metathesis reactions). Here we show that the addition of electrons to MgB2, through partial substitution of Al for Mg, results in the loss of superconductivity. Associated with the Al substitution is a subtle but distinct structural transition, reflected in the partial collapse of the spacing between boron layers near an Al content of 10 per cent. This indicates that superconducting MgB2 is poised very near a structural instability at slightly higher electron concentrations.

Strongly linked current flow in polycrystalline forms of the superconductor MgB2

The discovery of superconductivity at 39 K in magnesium diboride, MgB2, raises many issues, a critical one being whether this material resembles a high-temperature copper oxide superconductor or a low-temperature metallic superconductor in terms of its behaviour in strong magnetic fields. Although the copper oxides exhibit very high transition temperatures, their in-field performance is compromized by their large anisotropy, the result of which is to restrict high bulk current densities to a region much less than the full magnetic-field-temperature (H-T) space over which superconductivity is found. Moreover, the weak coupling across grain boundaries makes transport current densities in untextured polycrystalline samples low and strongly sensitive to magnetic field. Here we report that, despite the multiphase, untextured, microscale, subdivided nature of our MgB2 samples, supercurrents flow throughout the material without exhibiting strong sensitivity to weak magnetic fields. Our combined magnetization, magneto-optical, microscopy and X-ray investigations show that the supercurrent density is mostly determined by flux pinning, rather than by the grain boundary connectivity. Our results therefore suggest that this new superconductor class is not compromized by weak-link problems, a conclusion of significance for practical applications if higher temperature analogues of this compound can be discovered.

[Scaling the SF-36 in a Chinese population]

OBJECTIVE

To facilitate the cross-cultural comparison, we employed the principles of fuzzy mathematics in scaling the SF-36 in a Chinese population.

METHODS

We stratified an urban population according to the age, sex, and occupation, and selected 650 people to participate in the study. A total of 646 valid questionnaires were returned. In the 8 domains of the SF-36, the interval estimation of the scores of different alternative answers of 6 domains which have more than 2 alternative answers were conducted.

RESULTS

The fuzzy degrees of most interval estimations were less than 0.5, except 4 estimations in the domain "physical functions". The ordering of the scores of 8 domains was more similar to the original assumption by our scaling criteria than by the US scaling criteria.

CONCLUSION

The scaling criteria set in this study is more suitable for use in Chinese population and we suggest that the alternative answers of the domain "physical functions" be simplified to "yes" and "no".

TNF-alpha down-regulates CXCR4 expression in primary murine astrocytes

CXC chemokine receptor 4 (CXCR4) is a co-receptor for human immunodeficiency virus (HIV) infection and is believed to be involved in the pathogenesis of AIDS-associated neurologic disorders and brain tumors. The physiological roles of CXCR4 in developmental patterning of the nervous and hematopoietic system; gastrointestinal angiogenesis; and cardiac organogenesis were established by studies in gene-targeted mice. Studies on CXCR4 expression and regulation in neuroepithelial cells are fundamental for understanding its physiopathologic roles in the central nervous system (CNS). We show here that CXCR4 expression by primary mouse astrocytes is suppressed by exposure to tumor necrosis factor-alpha (TNF-alpha). TNF-alpha caused a pronounced down-regulation of CXCR4 mRNA in a dose- and time-dependent manner. TNF-alpha-mediated decrease of CXCR4 mRNA accumulation resulted in decreased CXCR4 protein expression. As a result, the ability of stromal cell-derived factor-1alpha (SDF-1alpha) to induce activation of MAP kinases, Erk1/2 was impaired. The half life of CXCR4 mRNA in the presence and absence of TNF-alpha stimulation was comparable, suggesting that TNF-alpha down-regulated CXCR4 mRNA at the transcriptional level. These results suggest that TNF-alpha could modulate HIV and brain tumor pathogenesis and immune-mediated inflammation in the central nervous system (CNS) by regulation of CXCR4 expression.

Dosimetric improvements following 3D planning of tangential breast irradiation

PURPOSE

To evaluate the dosimetric difference between a simple radiation therapy plan utilizing a single contour and a more complex three-dimensional (3D) plan utilizing multiple contours, lung inhomogeneity correction, and dose-based compensators.

METHODS AND MATERIALS

This is a study of the radiation therapy (RT) plans of 85 patients with early breast cancer. All patients were considered for breast-conserving management and treated by conventional tangential fields technique. Two plans were generated for each patient. The first RT plan was based on a single contour taken at the central axis and utilized two wedges. The second RT plan was generated by using the 3D planning system to design dose-based compensators after lung inhomogeneity correction had been made. The endpoints of the study were the comparison between the volumes receiving greater than 105% and greater than 110% of the reference dose, as well as the magnitude of the treated volume maximum dose. Dosimetric improvement was defined to be of significant value if the volume receiving > 105% of one plan was reduced by at least 50% with the absolute difference between the volumes being 5% or greater. The dosimetric improvements in 49 3D plans (58%) were considered of significant value. Patients' field separation and breast size did not predict the magnitude of improvement in dosimetry.

CONCLUSION

Dose-based compensator plans significantly reduced the volumes receiving > 105%, >110%, and volume maximum dose.

Characterization and evolutionary relevance of the sperm nuclear basic proteins from stickleback fish

We have characterized the sperm nuclear basic proteins (SNBPs) of the sticklebacks in the suborder Gasterosteoidei. The complete amino acid sequence of the protamines from Aulorhynchus flavidus, Pungitius pungitius, Gasterosteus aculeatus, (anadromous) and G. wheatlandi, as well as the sequences of the protamines of several species pairs of freshwater G. aculeatus, have been determined. Analysis of the primary structure of these proteins has shown that: a) despite the relatively low amino acid complexity and small molecular mass of these basic proteins, they are very good molecular markers at the generic level. The bootstrap parsimony analysis using their sequences provides a phylogenetic relationship for the old anadromous species of Gasterosteoidei which is identical to that obtained from morphological and behavioral analysis; b) the comparison of the sequences also suggests that protamines from the suborder Gasterosteoidei have most likely evolved from a common gene in the early Acanthopterygii by an extension of the carboxy terminal portion of the molecule; c) protamines are not good markers for recent postglacial freshwater isolates of G. aculeatus. However, in the unique case of Enos Lake (British Columbia), we have been able to detect an additional minor protamine component in the benthic forms of G. aculeatus that is not present in the limnetic forms. Thus, this new protamine must have appeared during the past 12,000 years concomitantly with the speciation of benthics and limnetics in this lake.

Genetic characterization of rebounding HIV-1 after cessation of highly active antiretroviral therapy

Despite prolonged treatment with highly active antiretroviral therapy (HAART), infectious HIV-1 continues to replicate and to reside latently in resting memory CD4(+) T lymphocytes, creating a major obstacle to HIV-1 eradication. It is therefore not surprising to observe a prompt viral rebound after discontinuation of HAART. The nature of the rebounding virus, however, remains undefined. We now report on the genetic characterization of rebounding viruses in eight patients in whom plasma viremia was undetectable throughout about 3 years of HAART. Taking advantage of the extensive length polymorphism in HIV-1 env, we found that in five patients who did not show HIV-1 replication during treatment, the rebound virus was identical to those isolated from the latent reservoir. In three other patients, two of whom had been free of plasma viremia but had showed some residual viral replication, the rebound virus was genetically different from the latent reservoir virus, corresponding instead to minor viral variants detected during the course of treatment in lymphoid tissues. We conclude that in cases with apparent complete HIV-1 suppression by HAART, viral rebound after cessation of therapy could have originated from the activation of virus from the latent reservoir. In patients with incomplete suppression by chemotherapy, however, the viral rebound is likely triggered by ongoing, low-level replication of HIV-1, perhaps occurring in lymphoid tissues.

Evidence for recent selection of the CCR5-delta 32 deletion from differences in its frequency between Ashkenazi and Sephardi Jews

Recent studies have shown higher frequencies of the CCR5-delta 32 allele and the CCR5-delta 32/delta 32 genotype, which confers protection against HIV infection, in northern Europe as compared to Mediterranean countries. Here, we analyse the prevalence of CCR5-delta 32 in 922 HIV seronegative blood donors in Israel to verify its frequency in Jews of Ashkenazi and Sephardi origin. A significant difference (P < 0.001) was found between the CCR5-delta 32 allele frequency in Ashkenazi (13.8%) vs (4.9%) Jews. In contrast, no significant difference was observed in the frequency of the CCR2-641 mutation between Ashkenazi (9.2%) and Sephardi (13.4%) Jews. Using the Island model we calculate that a minimal genetic migration rate of 3% per generation would have been necessary if the higher CCR5-delta 32 prevalence in Ashkenazi is to be fully explained by mixing with the indigenous north-European populations. This putative migration rate is 20-fold higher than that currently estimated from other genes, and would correspond to a non-realistic minimal current admixture of 80%. Thus, our results suggest that a positive selection process for CCR5-delta 32 should have occurred in northern Europe at most a 1000 years ago, after the Ashkenazi Jews separated from their Sephardi kin and moved to north Europe.

Prevalence of Bacteroides forsythus, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in subgingival microflora of Japanese patients with adult and rapidly progressive periodontitis

BACKGROUND, AIMS

This study investigated the prevalence of Bacteroides forsythus, Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans among various periodontitis patients and healthy individuals in Japan, and correlated it with clinical parameters.

METHOD

Subgingival plaque samples were collected from 21 patients with adult periodontitis (AP), 8 with rapidly progressive periodontitis (RPP) and 15 healthy individuals.

RESULTS

The frequency detected in culture was as follows: B. forsythus was found in 47.6% of AP sites and in 37.5% of RPP sites. P. gingivalis was identified in 64.3% of AP and 59.4% of RPP sites. A. actinomycetemcomitans was detected in 4.8% of AP and 3.1% of RPP sites. The 3 species were detected in only 2 of the healthy individuals. The proportion of B. forsythus in the total microflora in culture was 0.07% in the healthy group, 4.1% in AP and 2.4% in RPP. The proportions of P. gingivalis were 0% in the healthy group, 18.8% in AP and 16.2% in RPP. The proportion of A. actinomycetemcomitans was very low in all 3 groups. A DNA probe detected B. forsythus in 78.6% of AP and 65.6% of RPP sites, as well as P.gingivalis in 58.3% of AP and 59.4% of RPP sites. A. actinomycetemcomitans was detected in only 1.2% of AP sites. The 3 species were undetectable in the healthy group.

CONCLUSIONS

The prevalence and the proportion of B. forsythus and P. gingivalis were significantly correlated with clinical parameters, suggesting that B. forsythus and P. gingivalis are closely related to AP and RPP in the Japanese population.

[Chaos in electroencephalogram]

The history and current situation of EEG study were reviewed in the paper, with an emphasis on the application and the latest developments of chaos in EEG analysis. The problems in present study and the proposals for future investigations were finally discussed.

[Application of model 4650 type I compressor atomizer in bronchial challenge test]

This study was directed to the feasibility of applying a simple atomizer-model 4650 type I (abbrev. M)-to bronchial challenge test. 92 cases of asthma were divided into 3 groups randomly. All of them were subjected to the bronchial challenge test by M atomizer, and by standard Dosimeter atomizer (abbrev. D) as a comparison. In the test by M atomizer, the times for inspiring challenging medicine were 1, 1.5 and 2 minutes for the 3 groups respectively, while the time for D atomizer was 1 minute for all. The results showed no significant differences (P > 0.2-0.5) between the two atomizers in the 3 groups, their values were linear correlated. When the inspiring time was 1 minute for both M and D, the test needed a higher concentration of challenging medicine for M than for D, their coefficient of correlation (r = 0.285) was relatively low. When inspiring time postponed to 1.5 minute for M, the difference in medicine concentration between M and D was smallest (-0.075 g/L), r = 0.665. However, a further postponed inspiring time to 2 minute for M reversely broadened their difference. These results indicated that the efficiency of M atomizer was a little lower than that of D, postponing the inspiring time for M could make up this weakness. A 1.5 minute inspiring time for M atomizer was the suggestion. Some modifications on M atomizer were done by us for a better efficiency, and the cheap and popular M atomizer could be a good replacement in bronchial challenge test.

Intracellular sequestration of anti-tumor drugs by metallothionein

Acquired drug resistance is one of the most important problems in cancer chemotherapy. One of the mechanisms proposed to contribute to this phenomenon is the sequestration of alkylating agents by metallothionein (MT) in vivo. In this study cadmium-induced human bladder tumor T24 cells were exposed to the therapeutic agents chlorambucil and melphalan. MT-2a, was shown by capillary electrophoresis to comprise 56% of the MT isoforms in induced cells, and drug adducts of MT-2a were isolated and characterized by HPLC and electrospray ionization mass spectrometry. One to four equivalents of drug were found to be covalently adducted. Major binding sites on metallothionein were located in the C-terminal domain by peptide mapping, consistent with previous studies in vitro.