Evaluation of asthma control: a questionnaire-based survey in China

BACKGROUND

Little is known about asthma control and perception of asthma among asthmatic patients in China. This study marked the first survey conducted on a national scale that aimed at obtaining baseline information on asthma control and patients' perception of asthma and providing a point of reference for future studies.

METHODS

This face-to-face, questionnaire-based survey was conducted from April 2007 to March 2008 with 3 069 asthmatic patients from the respiratory outpatient clinics of 36 general hospitals located in 10 geographically dispersed cities.

RESULTS

Consistent with the Global Initiative for Asthma (GINA) guidelines, 28.7% and 45.0% of our patients achieved control and partial control, respectively. Of the patients in the study, only 21.8% had used a peak flow meter (PFM), and 6.6% of these patients used it daily. Inhaled corticosteroids (ICS) plus a long-acting β2 agonist (LABA) and ICS were the two most common medication regimens and were used in 45.6% and 30.4% of patients, respectively. Asthma had a significant effect on the patients' life and work. A considerable number of hospitalizations, emergency department visits, and sick days were observed.

CONCLUSION

Despite improvements in asthma control and ICS and PFM compliance compared with past literature, the current level of asthma control countrywide continues to fall short of the goals set in the GINA.

The impact of concomitant allergic rhinitis on asthma control: a cross-sectional nationwide survey in China

OBJECTIVES

Understanding the interactions between allergic rhinitis (AR) and asthma is important for asthma management. This study explored the clinical features of AR as a comorbidity in Chinese asthmatic patients and its impact on asthma control.

METHODS

This cross-sectional survey was conducted among 20 051 patients with asthma in an out-patient setting and covered all of the territories of China. The patients were interviewed face-to-face. A standardized questionnaire was completed by each patient. AR was defined according to the ARIA criteria. The level of asthma control was assessed by the Asthma Control Test. A score ≤19 indicated poorly controlled asthma.

RESULTS

AR was present in 69.9% of patients with asthma. Of them, 72.4% had intermittent symptoms, and 93.1% presented with moderate/severe symptoms. Cold air, irritant air and household mites were the most common triggers for AR. A higher percentage of patients with AR experienced poorly controlled asthma compared with those without AR (56.2% versus 51.5%, p < 0.001). AR was associated with an increased risk of poorly controlled asthma [odds ratio (OR): 1.21, p < 0.001]. Moderate/severe or persistent symptoms were associated with a higher risk of poorly controlled asthma than those with mild or intermittent symptoms (OR: 2.34 and 1.78, respectively, p < 0.001). In contrast, diagnosed AR (OR: 0.84, p < 0.001), being currently treated with medication (OR: 0.91, p = 0.004) and a prior skin prick test (OR: 0.90, p = 0.003) showed a significantly negative association with poorly controlled asthma.

CONCLUSION

This study confirms that concomitant AR and asthma are highly prevalent in China and that AR is associated with poor asthma control.

[A survey of knowledge on common cold in outpatient clinics]

OBJECTIVE

To investigate outpatients' cognition towards common cold and their habituated medication so as to provide evidence for future public healthcare education.

METHODS

Patients who attended hospital for diagnosis and treatment of common cold at least within past three months were asked to fill a questionnaire independently so as to learn their cognition towards common cold and medication habit.

RESULTS

Among the patients underwent survey, 52.21% had incorrect knowledge about common cold; 12.99% didn't know about the hazards of common cold; 34.80% couldn't distinguish common cold from influenza; 30.07% considered common cold couldn't get relief without treatment; 68.24% didn't know about the proper effects of influenza vaccination; 61.14% often took oral medicine even intravenous injection when they caught a common cold; 59.77% often took medication from drugstore without prescription by doctor, and a few asked doctors to prescribe medicine on their request; 19.42% didn't know about the side effects of drug for cold treatment; and 19.72% didn't know about the active ingredients of drug for cold treatment. There were significant differences in the common cold cognition among population of different ages and education background. The older or the higher education status patients had a better cognition (P < 0.01).

CONCLUSION

There exist a certain degree of wrong cognition towards common cold among patients of different literacy degree and different age. Public health education on common cold need to be further strengthened.

[A survey of knowledge on common cold and its treatment situation among physicians from various levels of hospitals in mainland China]

OBJECTIVE

To investigate the cognition of the common cold and current situation of the treatment among physicians from various levels of hospitals in Chinese mainland, so as to provide evidence for future continuing medical education and rational medication.

METHODS

A questionnaire designed for this survey was used to learn about the general information, cognitive degree of the common cold and prescription habits of physician who prescribed for cold within last three months, from various levels hospitals.

RESULTS

A total of 1001 physicians were interviewed. Among them, 749 physicians chose right options that the cold was the common cold and the influenza with 79.84% in resident physicians and 56.76% in chief physicians. A total of 745 physicians chose options that the course of common cold will be lasting 4 to 7 days; 895 physicians chose options that old people are the most susceptible for complication; 669 physicians thought the common cold was the most common infection in winter; 841 physicians used clinical methods to diagnose the common cold; 736 physicians thought although the cold was a kind of self-limited disease and symptomatic treatment could alleviate symptoms and improve life quality, patients should see doctor in time if it turns to severer; and 745 physicians held the opinion that treatment of the common cold should focus on relieving symptoms first. In addition, 61.60% physicians had made prescription based on clinical symptoms; 505 (54.24%) of them thought compound drugs were priority in treating the common cold. However, there were still 43 physicians prescribed antibiotics for common cold.

CONCLUSIONS

There is misunderstanding and discrepancy in cognition towards common cold and treatment among physicians from various levels of hospitals in mainland China. Physicians should standardize diagnosis and treatment for the common cold according to the domestic and foreign guidelines.

Atomic structure of nanoclusters in oxide-dispersion-strengthened steels

Oxide-dispersion-strengthened steels are the most promising structural materials for next-generation nuclear energy systems because of their excellent resistance to both irradiation damage and high-temperature creep. Although it has been known for a decade that the extraordinary mechanical properties of oxide-dispersion-strengthened steels originate from highly stabilized oxide nanoclusters with a size smaller than 5 nm, the structure of these nanoclusters has not been clarified and remains as one of the most important scientific issues in nuclear materials research. Here we report the atomic-scale characterization of the oxide nanoclusters using state-of-the-art Cs-corrected transmission electron microscopy. This study provides compelling evidence that the nanoclusters have a defective NaCl structure with a high lattice coherency with the bcc steel matrix. Plenty of point defects as well as strong structural affinity of nanoclusters with the steel matrix seem to be the most important reasons for the unusual stability of the clusters at high temperatures and in intensive neutron irradiation fields.

Novel C/Cu sheath/core nanostructures synthesized via low-temperature MOCVD

C/Cu sheath/core nanocable arrays were mass-produced on various substructures, such as Si, SiO(2), Cu or glass, by using a one-step low-temperature metal-organic chemical vapor deposition. The novel nanostructures consist of a faceted Cu nanowire core with six side surfaces and four top surfaces, and a sheath of carbon. The as-synthesized nanocables are demonstrated excellent oxidization resistance and field emission properties, and are expected to be excellent candidates as nano-interconnectors, or nanocables, in electronic devices and nano-emitters for field emissions.

Hepatocyte-targeted psiRNA delivery mediated by galactosylated poly(ethylene glycol)-graft-polyethylenimine in vitro

Gene silencing in liver disease could be achieved by delivering siRNA with nonviral vectors. However, the transfection efficiency of plasmid siRNA (psiRNA) applied through this approach in hepatocytes is generally low. Based on the fact that the asialoglycoprotein receptors present on hepatocytes can recognize galactose, we synthesized galactosylated poly(ethylene glycol)-graft-polyethylenimine (Gal-PEG-PEI) as a nonviral psiRNA carrier for hepatocyte targeting. Our results indicate that 0.2% (molar percentage) of amine groups of PEI was conjugated with PEG having galactose on its distal end. Increasing the molar ratios of Gal-PEG-PEI to psiRNA in complexation led to a decrease in particle size but an increase in zeta potential of complexes. The transfection efficiency of nanocomplexes, that is, Gal-PEG-PEI/psiRNA, in HepG2 cell line depends on the N/P value, which reflects the molar ratio of Gal-PEG-PEI to psiRNA in the complex. The highest transfection efficiency was 37.34%, which was obtained at N/P 8. At the same N/P value, the transfection efficiency with the nontargeting PEG-PEI/psiRNA or Lipofectamine 2000/psiRNA was much lower. The transfection efficiency of Gal-PEG-PEI/psiRNA dropped to 3.60% from 37.34% after an excessive amount of free galactose was added into the medium for HepG2 cell incubation. By contrast, the similar phenomenon was observed neither when using PEG-PEI or Lipofectamine 2000 as a delivery vector nor in human embryonic kidney 293 cell line lacking ASGR. Real-time PCR analysis and western blot assay demonstrate that the knockdown of HLA-E gene expression by psiRNA/Gal-PEG-PEI (N/P 8) can reach about 60% in HepG2 cells after a 48-h transfection.

Atomic-scale structural evolution and stability of supercooled liquid of a Zr-based bulk metallic glass

In this Letter, direct experimental evidence is provided for understanding the thermal stability with respect to crystallization in the Zr(41.2)Ti(13.8)Cu(12.5)Ni(10)Be(22.5) glass-forming liquid. Through high-resolution transmission electron microscopy, the atomic-structure evolution in the glass-forming liquid during the isothermal annealing process is clearly revealed. In contrast with the existing theoretical models, our results reveal that, prior to nanocrystallization, there exists a metastable state prone to forming icosahedralike atomic clusters, which impede the subsequent crystallization and hence stabilize the supercooled liquid. The outcome of the current research underpins the topological origin for the excellent thermal stability displayed by the Zr-based bulk metallic glass.

[In vitro study on the mechanism of myocardial injury induced by Formoterol and the protective effect of Budesonide in rats]

AIM

To investigate the mechanism of myocardial injury induced by Formoterol (FORM) in vitro and the protective effect of Budesonide (BUD) against such cardiac damage in rats.

METHODS

FORM was added in the media of isolated rat myocardial tissues in a concentration gradients of 0 μmol/L, 0.01 μmol/L, 0.05 μmol/L, 0.1 μmol/L, 0.5 μmol/L, 1 μmol/L, 5 μmol/L, respectively, or combined with BUD in a concentration of 10 μmol/L, for 72 hours in vitro. The cardiac troponin I (cTnI) and heart-type fatty acid-binding protein (H-FABP) in supernatant were detected with ELISA method. The mRNA level of glycogen synthase kinase-3β (GSK-3β) was detected with RT-PCR. Sarco(endo) plasmic reticulum Ca(2+);-ATPase (SERCA2) and GSK-3β protein expression were detected with Western blot.

RESULTS

(1) The values of cTnI and H-FABP were significantly higher in FORM groups, compared with the control group(P<0.05), and there was a difference between different FORM concentration gradients (P<0.05) except 1 μmol/L and 5 μmol/L groups. In FORM and BUD combined groups, the values of cTnI and H-FABP were significantly lower than FORM groups(P<0.05). (2) With the increase of FORM concentration, there were lower expression of SERCA2 (P<0.05) and higher expression of GSK-3β protein (P<0.05). But there was no significant statistic difference of GSK-3β mRNA between FORM treated groups (P>0.05).

CONCLUSION

(1) FORM can induce injury in rat's isolated myocardial tissues and the injury is concentration depended. BUD shows protective effect against FORM induced myocardial injury. (2) The mechanism of FORM induced myocardial injury may be associated with the lower expression of SERCA2, which is mediated by GSK-3β.

[Effect of RNA interference on CTGF expression and collagen synthesis induced by hypoxia in rat cardiac fibroblasts]

OBJECTIVE

To investigate the effect of the lentiviral vector pGCL-GFP transferred connective tissue growth factor (CTGF) short hairpin RNA (CTGF-ShRNA) on CTGF expression, cell proliferation and collagen synthesis induced by hypoxia in rat cardiac fibroblasts (CFs).

METHODS

CTGF-ShRNA plasmids successfully constructed and screened. CFs of adult Sprague-Dawley (SD) rats isolated with the method of trypsin digestion and differential anchoring velocity which randomly divided into the control group, the hypoxia group, Hypo+pGCL-GFP group and Hypo+CTGF-ShRNA group. The mRNA and protein levels of CTGF were detected by means of semi-quantitative reverse transcriptional polymerase chain reaction (RT-PCR) and Western blot 24 h later. Proliferation of CFs was observed by WST-1 coloricmetric assay and synthesis of collagen was observed by the hydroxyproline.

RESULTS

Successfully constructed and screened CTGF short hairpin RNA. Compared with control group, the expression of CTGF mRNA and protein levels induced by hypoxia in CFs were markedly up-regulated in Hypoxia, Hypo + pGCL-GFP and Hypo + CTGF-ShRNA group (P < 0.05). CFs proliferation and collagen synthesis in Hypoxia, Hypo+pGCL-GFP and Hypo+CTGF-ShRNA group were significantly higher than that of the control group (P < 0.05). In comparison to Hypoxia and Hypo+pGCL-GFP group, the CTGF mRNA and protein levels induced by hypoxia in CFs were markedly down-regulated in Hypo + CTGF-ShRNA group (P < 0.01). CFs proliferation and collagen synthesis in Hypo+CTGF-ShRNA group were significantly lower than that of the Hypoxia and Hypo+pGCL-GFP group (P < 0.01).

CONCLUSION

CTGF mRNA and protein expression, CFs proliferation and collagen synthesis induced by hypoxia in CFs effectively inhibited by CTGF-ShRNA.

Effects of formoterol-budesonide on airway remodeling in patients with moderate asthma

AIM

To evaluate the effect of inhaled formoterol-budesonide on airway remodeling in adult patients with moderate asthma.

METHODS

Thirty asthmatic patients and thirty control subjects were enrolled. Asthmatic subjects used inhaled Symbicort 4.5/160 μg twice daily for one year. The effect of formoterol-budesonide on airway remodeling was assessed with comparing high-resolution computer tomography (HRCT) images of asthmatic patients and controls, as well as expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness.

RESULTS

The differences in age and gender between the two groups were not significant. However, differences in FVC %pred, FEV(1) %pred, and PC(20) between the two groups were significant. After treatment with formoterol-budesonide, the asthma patients' symptoms were relieved, and their lung function was improved. The WT and WA% of HRCT images in patients with asthma was increased, whereas treatment with formoterol-budesonide caused these values to decrease. The expression of MMP-9, TIMP-1, and TGF-β(1) in induced sputum samples increased in patients with asthma and decreased dramatically after treatment with formoterol-budesonide. The WT and WA% are correlated with the expression levels of cytokines and growth factors, inflammatory cell count in induced sputum, and airway hyper-responsiveness, while these same values are correlated negatively with FEV(1)/FVC and FEV(1)%.

CONCLUSION

Formoterol-budesonide might interfere in chronic inflammation and airway remodeling in asthmatic patients. HRCT can be used to effectively evaluate airway remodeling in asthmatic patients.

Metallic liquids and glasses: atomic order and global packing

In this Letter, we have revealed the common structural behavior of metallic glasses through scrutinizing the evolution of pair distribution functions from metallic liquids to glasses and statistically analyzing pair distribution functions of 64 metallic glasses. It is found that the complex atomic configuration in metallic glasses can be interpreted globally as a combination of the spherical-periodic order and local translational symmetry. The implications of our study suggest that the glass transition could be visualized mainly as a process involving in local translational symmetry increased from the liquid to glassy states.

Atomistic free-volume zones and inelastic deformation of metallic glasses

The amorphous nature of metallic glasses and their mechanical properties make them interesting for structural applications. However, the interplay between the nature of atomic structures in metallic glasses and mechanical properties remains poorly understood. In this study, high-frequency dynamic micropillar tests have been used to probe both atomic clusters and flow defects in metallic glasses. We show that loosely bonded atomistic free-volume zones that are enveloped elastically by tightly bonded atomic clusters show a deformation character similar to supercooled liquids. At room temperature, the effective viscosity of these free-volume zones is of the order of 1 x 10(8) Pa s before the occurrence of shear banding. The confined liquid-like deformation of free-volume zones leads to significant mechanical hysteresis in micropillars under dynamic loading, providing important insight into how atomistic structural features affect the deformation behaviours in metallic glasses in the apparent elastic regime. The inelastic behaviour also serves as the basis for the superior damping resistance of metallic glasses.

Ductile ordered intermetallic alloys

Many ordered intermetallic alloys have attractive high-temperature properties; however, low ductility and brittle fracture limit their use for structural applications. The embrittlement in these alloys is mainly caused by an insufficient number of slip systems (bulk brittleness) and poor grain-boundary cohesion. Recent studies have shown that the ductility and fabricability of ordered intermetallics can be substantially improved by alloying processes and control of microstructural features through rapid solidification and thermomechanical treatments. These results demonstrate that the brittleness problem associated with ordered intermetallics can be overcome by using physical metallurgical principles. Application of these principles will be illustrated by results on Ni(3)Al and Ni(3)V-Co(3)V-Fe(3)V. The potential for developing these alloys as a new class of high-temperature structural materials is discussed.

[Bicuculline inhibits airway remodeling in a murine model of chronic asthma]

OBJECTIVE

To investigate the effect of bicuculline, a selective GABAA receptor antagonist, on airway remodeling in the murine model of chronic allergen-induced asthma.

METHODS

Forty BALB/C mice were randomized into 4 groups, namely the control group, asthmatic model (induced by ovalbumin sensitization and challenge) group, budesonide inhalation group and bicuculline inhalation group. The mice were sacrificed 24 h after the last ovalbumin inhalation, and the lungs were lavaged with PBS and the total cells, eosinophils and lymphocytes counts were examined. Periodic acid-Schiff (PAS) staining was used for counting mucin-positive goblet cells in the lung tissue, and Masson Trichrome staining was used to evaluate collagen deposition. GABAARbeta2 and VEGF were quantified by immunohistochemistry.

RESULTS

The numbers of the total cells, eosinophils and lymphocytes counts in BALF were significantly greater in the bicuculline group than in the control and budesonide groups (P<0.01), but comparable to those in the asthmatic model group (P>0.05). The airway collagen deposition in the bicuculline group was comparable to that in the control and budesonide group (P>0.05), but was significantly less than that in the asthmatic model group (P<0.05). Significant differences were found in the airway histological mucus index between the bicuculline group and the other 3 groups (P<0.05). The airway GABAARbeta2-positive cell percentage in the bicuculline group was significantly greater that those in the control and budesonide (P<0.01 and 0.05), but similar with that in the asthmatic model group (P>0.05). The percentage of pulmonary perivascular VEGF-positive cells in the bicuculline group was significantly greater in the control and budesonide groups (P<0.01 and P<0.05), but comparable to that in the asthmatic model group (P>0.05).

CONCLUSION

GABAARbeta2 is expressed in both the airway epithelium and smooth muscles. Bicuculline inhalation can effectively suppress collagen deposition with a stronger inhibitory effect on mucus hypersecretion than budesonide.

Thermodynamic origins of shear band formation and the universal scaling law of metallic glass strength

We report a universal scaling law, tau_{y} = 3R(T_{g}-RT)/V, that uncovers an inherent relationship of the yield strength tau_{y} with the glass transition temperature T_{g} and molar volume V of metallic glasses. This equation is derived from fundamental thermodynamics and validated by various metallic glasses with well-defined yielding. The linearity between tau_{y} and T_{g} demonstrates the intrinsic correlation between yielding and glass-liquid transition, which contributes to the basic understanding of the strength and deformation of glassy alloys.

Deformation crossover: from nano- to mesoscale

In situ synchrotron and neutron diffraction were used to study deformation mechanisms in Ni over a broad range of grain sizes. The experimental data show that unlike in coarse-grained metals, where the deformation is dominated by dislocation slip, plastic deformation in nanocrystalline Ni is mediated by grain-boundary activities, as evidenced by the lack of intergranular strain and texture development. For ultrafine-grained Ni, although dislocation slip is an active deformation mechanism, deformation twinning also plays an important role, whose propensity increases with the grain size.

Catalytic growth of metallic tungsten whiskers based on the vapor-solid-solid mechanism

Metallic W whiskers with tip diameters of 50-250 nm and lengths of 2-4 µm have been successfully synthesized in large quantities using Co-Ni alloyed catalysts. The relatively low growth temperature of 850 °C and the large catalyst size (over 100 nm) suggest that the growth of the W whiskers must be governed by the vapor-solid-solid mechanism. Our results show that the vapor-solid-solid model is suitable not only for the growth of nano-scaled whiskers with diameters below 100 nm, but also for submicro-scaled whiskers with diameters well above 100 nm. This technique has great potential to synthesize well controlled metallic whiskers.

Hyperbaric oxygen induces endogenous neural stem cells to proliferate and differentiate in hypoxic-ischemic brain damage in neonatal rats

BACKGROUND AND PURPOSE

Studies suggest that after brain injury, hyperbaric oxygen (HBO2) is neuroprotective by stimulating cell proliferation. We examine whether HBO2 promotes neural stem cells (NSC) to proliferate and differentiate in neonatal hypoxic-ischemic (HI) rats.

METHODS

Seven-day-old rat pups were subjected to unilateral carotid artery ligation followed by 2 hours of hypoxia (8% O2). HBO2 was administered (2 ATA (atmospheres absolutes), once daily for 7 days) within 3 hours after HI. The proliferating neural stem cells in the subventricular zone (SVZ) and dentate gyrus (DG) were dynamically examined by 5-bromo-2-deoxyuridine (BrdU)/nestin immunofluorescence. Nestin protein was detected by western blot analysis at various time points (from 6 hours to 14 days) after HI. The migrating NSC were examined by BrdU/doublecortin (DCX) immunofluorescence 7 and 14 days after HI. The phenotype of the newborn cells was identified by BrdU/beta-tubulin, BrdU/ glial fibrillary acidic protein (GFAP) and BrdU/O4 (oligodendrocyte marker) immunofluorescence. Myelin basic protein (MBP) was examined by immunohistochemistry and pathological changes of the brain tissue were detected 28 days after HI.

RESULTS

In neonatal HI rats treated with HBO2, the proliferation of endogenous NSC was observed in the SVZ and DG. Cell numbers peaked 7 days after HI and proliferating NSC migrated to the cerebral cortex at 14 d after HI. Twenty-eight days after HI, an increase in newly generated neurons, oligodendrocytes and MBP was observed in the HBO2 group compared to the untreated and HI-treated rats.

CONCLUSIONS

This study suggests that HBO2 treatment may promote neurogenesis of the endogenous NSC in neonatal HI rats, contributing to repair of the injured brain.

[A clinical study on the significance of airway hyperresponsiveness monitoring in the adjustment of combined therapy for asthmatic patients]

OBJECTIVE

To monitor the changes of symptom scores, airway hyperresponsiveness (AHR, represented by PC(35) sGaw), FEV(1)% and PEF% in patients with mild and moderate persistent asthma who received combined therapy of inhaled corticosteroids (ICS) and long-acting beta(2) agonists (LABA) and to evaluate the clinical significance of PC(35) sGaw and other parameters in guiding the adjustment of asthma stepwise therapy.

METHODS

Patients with asthma were allocated randomly to group A (22 subjects), B (22 subjects), and C (21 subjects). The initial regimens for all patients in the first three months included ICS (fluticasone) plus LABA (salmeterol). For patients in group A, a fixed dosage was maintained for 18 months, while those in group B received tailored dosage or withdrawal of therapy according to the clinical control level (well or total control). The regimens for patients in group C included step-down or withdrawal according to PC(35) sGaw besides the clinical control. All subjects were followed-up for 18 months and the symptom scores, PC(35) sGaw, FEV(1)% and PEF% were measured and analyzed. The asthma clinical control levels of the three groups at end point were compared.

RESULTS

A total of 65 subjects were enrolled and 46 completed the study. From the first to the third month after treatment, the symptom scores, FEV(1)% and PEF% improved significantly (t = 9.54, 13.17, 14.27, 12.4, 6.72, 6.59, 8.31, 5.22, and 5.96, respectively, all P < 0.01), and then maintained at relatively normal levels in a narrow range without significant progressive improvement during the later phases of the study. Meanwhile AHR declined abruptly in the first three months (t = 9.71, 12.04, and 14.31 in group A, B, C, respectively, all P < 0.01), followed by a slow but continuous improvement from the third to ninth month, and then maintained at a very low level. AHR disappeared in 4 cases but relapsed in 1 case after therapy withdrawal. The asthma clinical control level at the end point of group A, group B and group C were 93.3%, 53.3% and 93.8%, respectively (group A and group C versus group B, P < 0.01, respectively; group A versus group C, P > 0.05). There were fewer patients who underwent step-down therapy or withdrawal in group C compared to group B. However, patients in group C gained better asthma control and experienced less exacerbations compared to those in group B.

CONCLUSIONS

(1) Combined therapy with ICS plus LABA significantly improves symptoms, lung function and AHR of asthmatic patients. (2) Adjustment of therapy based only on clinical parameters may lead to early step-down or withdrawal and therefore asthma exacerbations. (3) PC(35) sGaw, an index of AHR, may be valuable in assessing asthma severity, evaluating the efficacy of treatment and guiding medication adjustment.

Creep-resistant, Al2O3-forming austenitic stainless steels

A family of inexpensive, Al2O3-forming, high-creep strength austenitic stainless steels has been developed. The alloys are based on Fe-20Ni-14Cr-2.5Al weight percent, with strengthening achieved through nanodispersions of NbC. These alloys offer the potential to substantially increase the operating temperatures of structural components and can be used under the aggressive oxidizing conditions encountered in energy-conversion systems. Protective Al2O3 scale formation was achieved with smaller amounts of aluminum in austenitic alloys than previously used, provided that the titanium and vanadium alloying additions frequently used for strengthening were eliminated. The smaller amounts of aluminum permitted stabilization of the austenitic matrix structure and made it possible to obtain excellent creep resistance. Creep-rupture lifetime exceeding 2000 hours at 750 degrees C and 100 megapascals in air, and resistance to oxidation in air with 10% water vapor at 650 degrees and 800 degrees C, were demonstrated.

Effects of Astragalus membranaceus in promoting T-helper cell type 1 polarization and interferon-gamma production by up-regulating T-bet expression in patients with asthma

OBJECTIVE

To explore the effect of Astragalus membranaceus (AM) on T-helper cell type 1 (Thl) specific transcription factor T-box expressed in T cells (T-bet) expression and Thl/Th2 equilibrium.

METHODS

The levels of T-bet mRNA in peripheral blood mononuclear cells (PBMCs) from 15 patients with asthma and 15 healthy subjects were determined by reverse transcription-polymerase chain reaction (RT-PCR). PBMCs in asthma patients were incubated with AM and then the concentration of interferon gamma (IFN-gamma) and interleukin-4 (IL-4) in the supernate before and after AM intervention were determined by ELISA. The numbers of CD4 + CCR3 + and CD4 + CCR5 + cells were counted by flow cytometry.

RESULTS

The expression of T-bet mRNA and the level of IFN-gamma were lower, but level of serum IL-4 was higher in asthma patients when compared with those in healthy subjects respectively. After AM (60 microg/ml) intervention, the former two parameters raised and showed a positive correlation between them, while the level of IL-4 was decreased. The mean percentage of CD4 + CCR3 + cells in asthma patients was significantly higher but that of CD4 + CCR5 + cells was lower when compared with those in healthy subjects respectively. After AM intervention, the abnormal change in the two indexes was improved to certain extent, showing a reversing status of Th2 polarization.

CONCLUSION

AM could increase the expression of T-bet mRNA and Thl cytokines such as IFN-Y, and might reverse the Th2 predominant status in asthma patients.

Immune response, ciprofloxacin activity, and gender differences after human experimental challenge by two strains of enterotoxigenic Escherichia coli

In order to test vaccines against enterotoxigenic Escherichia coli (ETEC)-induced diarrhea, challenge models are needed. In this study we compared clinical and immunological responses after North American volunteers were orally challenged by two ETEC strains. Groups of approximately eight volunteers received 10(9) or 10(10) CFU of E. coli B7A (LT+ ST+ CS6+) or 10(8) or 10(9) CFU of E. coli H10407 (LT+ ST+ CFA/I+). About 75% of the volunteers developed diarrhea after challenge with 10(10) CFU B7A or either dose of H10407. B7A had a shorter incubation period than H10407 (P = 0.001) and caused milder illness; the mean diarrheal output after H10407 challenge was nearly twice that after B7A challenge (P = 0.01). Females had more abdominal complaints, and males had a higher incidence of fever. Ciprofloxacin generally diminished or stopped symptoms and shedding by the second day of antibiotic treatment, but four subjects shed for one to four additional days. The immune responses to colonization factors CS6 and colonization factor antigen I (CFA/I) and to heat-labile toxin (LT) were measured. The responses to CFA/I were the most robust responses; all volunteers who received H10407 had serum immunoglobulin A (IgA) and IgG responses, and all but one volunteer had antibody-secreting cell (ASC) responses. One-half the volunteers who received B7A had an ASC response to CS6, and about one-third had serum IgA or IgG responses. Despite the differences in clinical illness and immune responses to colonization factors, the immune responses to LT were similar in all groups and were intermediate between the CFA/I and CS6 responses. These results provide standards for immune responses after ETEC vaccination.

[A study on the relevance of airway inflammatory indices in induced sputum and airway hyperresponsiveness in asthmatics]

OBJECTIVE

To analyze the correlations between NO(3)(-)/NO(2)(-), eosinophil counts in induced sputum and airway hyperresponsiveness (AHR) and therefore to explore the clinical significance of these parameters in severity assessment and medication adjustment in patients with mild to moderate asthma.

METHODS

From February 2003 to June 2004, 35 outpatients with mild to moderate persistent asthma (mild: 9, moderate: 26) from Huaxi Hospital asthma clinic were treated with combined medications of inhaled corticosteroids (ICS) plus long-acting beta(2) agonist (LABA) for one year. The symptom scores were recorded, and AHR (represented by PC(35)sGaw), eosinophil counts and NO(3)(-)/NO(2)(-) concentrations in induced sputum were measured at regular intervals. Fifteen healthy volunteers served as control and eosinophil counts and NO(3)(-)/NO(2)(-) concentrations in induced sputum were measured.

RESULTS

A total of 35 subjects were enrolled, of whom 26 completed one-year or longer follow-up. PC(35)sGaw of 26 subjects before treatment was 0.08 g/L, which became 1.40 g/L at the third months, and then maintained at a very low level (2.64 g/L) after the seventh month. NO(3)(-)/NO(2)(-) decreased from [(734 +/- 72) x 10(-3) g/L] to [(230 +/- 41) x 10(-3) g/L] by the third month (q = 6.26, P < 0.05), and [(137 +/- 27) x 10(-3) g/L] by the seventh month, which showed no significant difference with normal control (136 +/- 20) x 10(-3) g/L, q = 3.77, P > 0.05). Eosinophil counts decreased from (0.016 +/- 0.008) to (0.014 +/- 0.007) by the third month, which was not significantly different from normal control (q = 2.94, P > 0.05). In the first fifth months the concentration of NO(3)(-)/NO(2)(-) in induced sputum exhibited a significant negative correlation with PC(35)sGaw (r(1) = -0.872, r(2) = -0.653, r(3) = -0.639, r(4) = -0.656, all P < 0.05). But eosinophil counts had no correlation with PC(35)sGaw in the first three months (r(1) = 0.237, r(2) = 0.536, r(3) = 0.675, all P > 0.05).

CONCLUSION

The parameters related to airway inflammation including PC(35)sGaw and sputum NO(3)(-)/NO(2)(-) may be useful in assessing asthma severity, evaluating the efficacy of treatment and adjusting medication regimens.

[The roles of interleukin-5 and eotaxin in signal transmission between lung and bone marrow of rat asthmatic models]

OBJECTIVE

To explore the roles of interleukin-5 (IL-5) and eotaxin in signal transmission between lung and bone marrow in rat asthmatic models and to investigate the effects of different interventions on the signal transmission.

METHODS

Forty Wistar rats were randomly assigned to a control group and an asthma group (20 in each group). The asthmatic model were established by ovalbumin (OVA) sensitizing and challenging. The animals were sacrificed 30 min, 6 h, 12 h, 24 h, and 48 h after challenging, respectively. Slides were prepared from peripheral blood, bone marrow, and lung tissue respectively, and stained with HE. Then the total number and percentage of eosinophils (EOS) were counted. The concentrations of IL-5 and eotaxin in the lung homogenate at the different time points were determined by Enzyme-linked immunosorbent assay (ELISA). The bone marrow cells of the control rats and sensitized rats were incubated with lung homogenate of the different time points, and treated with dexamethasone (DXM), Galectin-3, anti-IL-5 polyclonal antibody, and montelukast, respectively. The bone marrow cell slides were stained with anti-IL-5 polyclonal antibody, anti-IL-5Ralpha polyclonal antibody, anti-eotaxin polyclonal antibody, anti-CD(34) polyclonal antibody, and anti-CCR(3) polyclonal antibody, respectively. The EOS and immunoactive cells were counted and represented as percentages of the total cells.

RESULT

The percentages of EOS in peripheral blood, bone marrow, and lung tissue from the asthma group were 0.0200 +/- 0.0020, 0.023 +/- 0.003, 0.0250 +/- 0.0090, and those from the control group were 0.0100 +/- 0.0030, 0.009 +/- 0.003, 0.0090 +/- 0.0020 respectively. The differences were significant between the two groups (t = 2.547, 2.718, 2.718, all P < 0.05). The peak levels of IL-5 and eotaxin were (89.3 +/- 2.4) pg/ml at 6 h and (4.9 +/- 0.5) pg/ml at 12 h after allergy challenge, respectively, then the levels returned to the baseline value after 48 h (1.45 +/- 0.23) pg/ml. Except at 30 min, all other lung homogenate samples induced the increase of percentages of IL-5(+), IL-5Ralpha(+), eotaxin(+), CD(34)(+) and CCR(3)(+) immunoactive cells. After treatment with Galectin-3, the percentages of IL-5(+), IL-5Ralpha(+), eotaxin(+), CD(34)(+) and CCR(3)(+) immunoactive cells decreased to 0.021 +/- 0.005, 0.074 +/- 0.007, 0.138 +/- 0.014, 0.067 +/- 0.010, 0.040 +/- 0.005, 0.087 +/- 0.012.

CONCLUSION

Galectin-3, a selective inhibitor of IL-5 mRNA transcription, potentially suppresses eosinophilic inflammation and might be a promising specific anti-asthma agent.

[STAT1 antisense oligonucleotides inhibit secretion of TNF-alpha, IL-8 and NO in alveolar macrophages of rats suffering from interstitial pulmonary fibrosis]

AIM

To investigate the effect of signal transducer and activator of transcription 1 (STAT1) antisense oligonucleotides (ASON) on secretion of TNF-alpha, IL-8 and NO by alveolar macrophages (AMs) of rats with bleomycin (BLM)-induced pulmonary fibrosis.

METHODS

Five adult female Wistar rats were intratracheally instilled with BLM. After 7 days, the rats were sacrificed under ketamine anaesthesia and bronchoalveolar lavage (BAL) was performed to obtain AMs. AMs were divided into four groups: STAT1 ASON, STAT1 sense oligonucleotides (SON), dexamethasone (DEX) and control groups. Culture medium was collected at 36 hours after adding STAT1 ASON, STAT1 SON and DEX, respectively. The concentrations of TNF-alpha, IL-8 and NO in the culture medium were detected.

RESULTS

The concentrations of TNF-alpha, IL-8 and NO in STAT1 ASON group were lower than those in STAT1 SON, DEX and control groups (P<0.05). Moreover, the concentrations of TNF-alpha, IL-8 and NO in DEX group were also lower than those in control and STAT1 SON groups (P<0.05). But compared with control group, the concentrations of TNF-alpha, IL-8 and NO in STAT1 SON group was not significantly different (P<0.05).

CONCLUSION

STAT1 ASON can inhibit the secretion of TNF-alpha, IL-8 and NO in AMs. STAT1 may become a target for treating pulmonary fibrosis.

Mechanical behavior of bulk amorphous alloys reinforced by ductile particles at cryogenic temperatures

The mechanical behavior of Zr-based bulk amorphous alloy composites (BAACs) was investigated at 77 K. The 5 vol. % Ta-BAAC maintained large plastic strains of approximately 13% with a 16% strength increase, when compared with that at 298 K. The interaction between shear bands and particles shows that shear extension in particles has limited penetration, and shear bands build up around particles. In addition to on the failure surface of the amorphous matrix, molten characteristics were also found on the surface of sheared particles. Pair distribution function studies were performed to understand the mechanical behavior.

Effect of phosphorus limitation on microbial floc structure and gene expression in activated sludge

The effect of limiting phosphorus (P) in activated sludge was investigated in laboratory-scale sequencing batch reactors (SBRs). Correlative microscopy revealed that P-limitation (COD:N:P = 100:5:0.05) leads to morphological changes in floc structure and the composition of extracellular polymeric substances (EPS). This was found to be accompanied by expression of quorum-sensing in an acyl homoserine lactone bioassay. Differential gene expression in relation to P-limitation was examined in a global profile using the Affymetrix Escherichia coli antisense genomic microarray. Three separate experiments were conducted where the impact of P-limitation was examined under batch conditions and in SBRs at stable operating conditions and within 3-7 days following a down-shift in P. Significant changes in open reading frames (ORF) and intergenic regions based on the E. coli microarray were observed. Several genes associated with cell structure, including slt, wbbH, fimH, amB, rfaJ and slp were found to be expressed. Quorum regulated genes were also found to be expressed including psiF which is known to be induced by P-starvation (92% confidence level; 1.45 log ratio).

[The effect of STAT1 antisense oligonucleotides on lung fibroblast proliferation and hydroxyproline secretion]

OBJECTIVE

To investigate the effect of signal transducer and activator of transcription 1 (STAT1) antisense oligonucleotides on lung fibroblast proliferation and hydroxyproline secretion.

METHODS

Ten adult female Wistar rats were randomly divided into two groups: one group was intratracheally instilled with bleomycin (BLM), while another group with 0.9% NaCl solution (NS). After 7 days, the rats were killed by right ventricle of heart exsanguinations under ketamine anaesthesia, and bronchoalveolar lavage (BAL) was performed to obtain alveolar macrophage (AM). AMs from the BLM group were divided into four groups, treated with STAT1 antisense oligonucleotides, STAT1 sense oligonucleotides, dexamethasone and medium alone (control), respectively. AMs and media were collected after culture for 36 h. The mRNA and protein expression of STAT1 and ICAM-1 in AMs were detected by RT-PCR and Cell-ELISA, respectively. The conditioned media were co-cultured with lung fibroblasts for 30 h, and then the cell proliferation and the concentration of hydroxyproline were examined.

RESULTS

(1) The STAT1 mRNA expression by AMs in the STAT1 antisense oligonucleotides group (31.8 +/- 3.5) was lower than those of AMs in the STAT1 sense oligonucleotides group (64.2 +/- 4.3), the dexamethasone group (44.1 +/- 4.6) and the control group (65.5 +/- 4.6) (P < 0.05). Moreover, the STAT1 mRNA expression by AMs in the dexamethasone group was also lower than those of AMs in the STAT1 sense oligonucleotides group and the control group (P < 0.05), but the STAT1 mRNA expression by AMs in the STAT1 sense oligonucleotides group was not different from that of the control group (P > 0.05). The STAT1 mRNA expression by AMs in the NS group (14.9 +/- 3.1) was lower than those of AMs in the STAT1 antisense oligonucleotides group, the STAT1 sense oligonucleotides group, the dexamethasone group and the control group (P < 0.05). (2) The mRNA expression of ICAM-1 showed similar changes to the STAT1 mRNA expression by AMs. (3) The STAT1 protein expression by AMs in the STAT1 antisense oligonucleotides group (4.4 +/- 0.6) or in the NS group (3.7 +/- 0.4) was lower than those of AMs in the STAT1 sense oligonucleotides group (7.7 +/- 0.7), the dexamethasone group (5.9 +/- 0.4) and the control group (7.6 +/- 0.6) (P < 0.05); and the STAT1 protein expression by AMs in the dexamethasone group was also lower than those of AMs in the STAT1 sense oligonucleotides group and the control group (P < 0.05), but the STAT1 protein expression by AMs in the STAT1 sense oligonucleotides group was not different from that of the control group (P > 0.05). (4) The changes of ICAM-1 protein expression, lung fibroblast proliferation and hydroxyproline concentration were consistent with the changes of STAT1 protein expression by AMs.

CONCLUSIONS

STAT1 antisense oligonucleotides could inhibit the mRNA and the protein expression of STAT1 and ICAM-1 in AMs. STAT1 antisense oligonucleotides also inhibited lung fibroblast proliferation and hydroxyproline secretion.

[Simvastatin induces eosinophil apoptosis in vitro]

OBJECTIVE

To investigate the effect of simvastatin, a 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) inhibitor, on eosinophils (EOSs) apoptosis in asthma patients.

METHODS

Peripheral blood EOSs from 10 asthma patients were cultured in the presence or absence of simvastatin (1, 5, 10, 20 micromol/L), together with or without mevalonate (100 micromol/L) for 6, 12, 24, and 48 h. Apoptosis was monitored by annexin V/PI staining and flow cytometry. Caspase-3 was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

EOSs were particularly susceptible to apoptosis after incubated with 5 micromol/L simvastatin for 6, 12, 24, and 48 h [the rates of EOSs undergoing apoptosis were: (23 +/- 3)%, (24 +/- 3)%, (41 +/- 6)%, (70 +/- 12)% in control and (32 +/- 4)%, (47 +/- 7)%, (62 +/- 9)%, (86 +/- 14)% in simvastatin; compared with control at the same time point: P = 0.000]. EOS apoptosis occurred at doses of 1 micromol/L and was already maximal at 5 micromol/L after incubated with simvastatin for 12 h [the rates of EOSs undergoing apoptosis were: (24 +/- 3)% in control, (37 +/- 3)%, (51 +/- 3)%, (53 +/- 4)%, (52 +/- 4)% in 1, 5, 10, 20 micromol/L simvastatin, respectively; compared with control: P = 0.000]. The level of caspase-3 in EOSs was consistent with the rate of cell apoptosis [(8 +/- 3) microg/L in control, (14 +/- 4), (22 +/- 4), (24 +/- 4), (23 +/- 5) microg/L in 1, 5, 10, 20 micromol/L simvastatin, respectively; compared with control: P = 0.000 - 0.003]. However, Co-incubation of simvastatin with mevalonate (the production of HMGR) completely reversed the activity of simvastatin on EOS apoptosis even when the highest simvastatin (20 micromol/L) dose was used; the rates of EOSs undergoing apoptosis in the control, mevalonate plus simvastatin and simvastatin alone were (24 +/- 3)%, (52 +/- 4)% and (25 +/- 3)%, respectively; while the caspase-3 levels were (8 +/- 3) microg/L, (23 +/- 5) microg/L and (9 +/- 3) microg/L, respectively.

CONCLUSION

Simvastatin induces apoptosis of EOSs in asthma patients via its ability to block the synthesis of the important isoprenoid intermediates, which leads to the inhibition of small GTP-binding protein activity.

[Inhibitory effects of Galectin-3 on the inflammatory cytokines and chemokines in guinea pig asthma models]

OBJECTIVE

To elucidate the roles of interleukin-5 (IL-5), Eotaxin, and CCR-3 in eosinophilic inflammation in guinea pig asthma models and investigate the inhibitory effects of Galectin-3.

METHODS

Thirty-two guinea pigs were randomly assigned to control group, asthma group, Galectin-3 intervention group, and dexamethasone (DXM) intervention group. Asthma models were established by sensitizing-challenging the animals with ovalbumin(OVA). The asthmatic animals were treated with Galectin-3 at 0.5 mg/kg, or DXM at 1 mg/kg, respectively,by peritoneally injection one hour before each aerosol challenge from the 14th day to 16th day after sensitization while the control animals were treated with normal saline. The specimens of peripheral blood, bone marrow, and lung tissue on slides were prepared respectively and stained with HE. Then the total number and percentage of eosinophils (EOS) were counted. The lung tissue slide was stained immunochemically with anti-IL-5 polyclonal antibody, anti-Eotaxin polyclonal antibody, and anti-CCR-3 polyclonal antibody, respectively. The immunoactive cells were counted and represented as percentages in total cells.

RESULTS

The amounts of EOS in peripheral blood, bone marrow,and lung tissue as well as percentages of IL-5, Eotaxin,and CCR-3 immunoactive cells in the lung tissue from asthma group were increased significantly, compared to those from control group. DXM significantly decreased the amounts of EOS, percentages of IL-5, Eotaxin, and CCR-3 immunoactive cells (P < 0.05). Galectin-3 had an equivalent suppressive effects on the amounts of EOS and IL-5+ cells with DXM (P > 0.05) and down-regulated CCR-3 expression (P < 0.05) to a less extent when compared to DXM (P < 0.05), but had minimal effect on Eotaxin expression (P > 0.05).

CONCLUSION

This study provides further evidence for an eosinophil recruitment from bone marrow to circulation blood to lung in asthmatic response, in which overexpression of IL-5, Eotaxin, and CCR-3 could be involved. Galectin-3, a selective inhibitor of IL-5 mRNA transcription, might potentially suppress eosinophilc inflammation and be a compromising specific anti-asthma reagent.

The electrochemical evaluation of a Zr-based bulk metallic glass in a phosphate-buffered saline electrolyte

Bulk metallic glasses (BMGs) represent an emerging class of materials with an amorphous structure and a unique combination of properties. The objectives of this investigation were to define the electrochemical behavior of a specific Zr-based BMG alloy in a physiologically relevant environment and to compare these properties to standard, crystalline biomaterials as well as other Zr-based BMG compositions. Cyclic-anodic-polarization studies were conducted with a Zr52.5Cu17.9Ni14.6Al10.0Ti5.0 (at %) BMG in a phosphate-buffered saline electrolyte with a physiologically relevant oxygen content at 37 degrees C. The results were compared to three common, crystalline biomaterials: CoCrMo, 316L stainless steel, and Ti-6Al-4V. The BMG alloy was found to have a lower corrosion penetration rate (CPR), as compared to the 316L stainless steel, and an equivalent CPR, as compared to the CoCrMo and Ti-6Al-4V alloys. Furthermore, the BMG alloy demonstrated better localized corrosion resistance than the 316L stainless steel. However, the localized corrosion resistance of the BMG alloy was not as high as those of the CoCrMo and Ti-6Al-4V alloys in the tested environment. The excellent electrochemical properties demonstrated by the BMG alloy are combined with a low modulus and unparalleled strength. This unique combination of properties dramatically demonstrates the potential for amorphous alloys as a new generation of biomaterials.

Cell Cycle Stage Analysis of Rabbit Foetal Fibroblasts and Cumulus Cells

Synchronization of the cell cycle stages in G0/G1 phase is one of the key factors determining the success of nuclear transplantation. Serum deprivation, contact inhibition and chemical inhibitors are widely used methods for this purpose. In this study, cell cycle stages of foetal fibroblasts and cumulus cells were determined using flow cytometry [fluorescence-activated cell scan (FACS)]. Foetal fibroblasts (in vitro cultured for 72-120 h) and fresh cumulus cells were analysed in Experiment 1. Fifty to 55% proliferating fibroblasts remained in G0/G1 phase compared with 78% in confluent culture (p <0.05). In contrast to foetal fibroblasts, fresh cumulus cells maintained 90% of the population in the G0/G1 stage. When serum was retrieved from the proliferating fibroblasts from day 1 to day 5 (Experiment 2), proportions of G0/G1 cells increased from the initial ratio of 53 to 87% at day 4 of starvation, which was significantly higher than the non-starved proliferating cells (p <0.05). In Experiment 3, fibroblasts were treated with aphidicolin (0.1 microg/ml, 6 h), demicolcine (0.5 microg/ml, 10 h), or a combination of these two chemicals to synchronize the cell cycle stages. Surprisingly, no differences or significantly lower in the proportions of G0/G1)phase cells were detected (25-50%) compared with the uncontrolled growing cells (53%). These results suggested that fresh cumulus cells rest their cell cycle in G0/G1 stage. Serum deprivation became effective in the first 24 h and reached the highest proportions during days 4-5 after deprivation. Chemical synchronization of the cell cycle stage of rabbit foetal fibroblasts to G0/G1 phase appeared less effective compared to serum deprivation.

Structural amorphous steels

Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist's dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

[The effects of anti-inflammatory and anti-asthmatic agents on CD34+ hematopoietic cells in bone marrow of asthmatic mice]

OBJECTIVE

To observe the effects of glucocorticoids and cysteinyl leukotrienes 1 receptor antagonist on CD(34)(+) hematopoietic cells, and to study the rationality of a bone marrow-targeting anti-inflammatory strategy.

METHODS

Twenty-four BALB/c mice were sensitized and challenged by 1% ovalbumin (OVA) to establish the asthmatic model. Asthmatic mice were challenged by 1% OVA and divided into 4 groups: fed by sterile saline (group A), prednisone (group B), montelukast (group C) and prednisone plus montelukast (group D) respectively for two consecutive weeks. The mice were killed at 24 h after the last challenge, then bronchoalveolar lavage fluid (BALF), peripheral blood and bone marrow were prepared. Eosinophils in peripheral blood and BALF, nucleate cells in BALF, peripheral blood and bone marrow were counted. The percentage of CD(34)(+) cells, CD(4)(+), CD(8)(+) T lymphocyte to nucleate cells in peripheral blood and bone marrow were counted by flow cytometry. Immunocytochemistry and in situ hybridization were employed to detect the hematopoietic cells expression of CD(34)(+) and IL-5Ralpha mRNA in bone marrow (CD(34)(+) IL-5Ralpha mRNA(+) cells).

RESULTS

The number of EOS in BALF and peripheral blood and the number of CD(34)(+) cells in peripheral blood and bone marrow in group A were [(18.3 +/- 1.3) x 10(5)/L], [(2.5 +/- 0.4) x 10(8)/L], [(9.6 +/- 5.1) x 10(7)/L] and [(7.7 +/- 3.2) x 10(7)/femur] respectively, compared with the corresponding indices in group B [(4.6 +/- 1.7) x 10(5)/L, (1.5 +/- 0.3) x 10(8)/L, (3.9 +/- 2.1) x 10(7)/L, (3.3 +/- 1.8) x 10(7)/femur] and group D [(3.7 +/- 1.4) x 10(5)/L, (1.7 +/- 0.3) x 10(8)/L, (4.1 +/- 1.8) x 10(7)/L, (2.2 +/- 0.7) x 10(7)/femur]; the differences all were significant (all P < 0.01). The number of bone marrow CD(34)(+) IL-5Ralpha mRNA(+) in group B and D were (23 +/- 7)% and (21 +/- 4)%, as compared with the corresponding index in group A [(37 +/- 4)%], the differences were significant (P < 0.01); the number of eosinophils in BALF in group C was (12.2 +/- 1.1) x 10(5)/L, as compared with the corresponding index in group A [(18.3 +/- 1.3) x 10(5)/L], the difference was significant (P < 0.05).

CONCLUSIONS

Prednisone probably inhibits the proliferation, differentiation and emigration of CD(34)(+) cells in the bone marrow of asthmatic mice, and inhibits eosinophilopoiesis in bone marrow, eosinophil migration into peripheral blood and recruitment to the airways. Montelukast may suppress eosinophil infiltrating into lungs of asthmatic mice, but it does not inhibit the proliferation and emigration of CD(34)(+) cells and does not show apparent synergistic effect with prednisone.

Relationship between bone marrow-derived CD34 + cells expressing interleukin-5 receptor messenger RNA and asthmatic airway inflammation

BACKGROUND

Asthma is clinically related with the degree of eosinophilic inflammation. How asthmatic airway inflammation is affected is still poorly understood. So the effects of bone marrow-derived hematopoietic cells expressing CD(34) (CD(34)(+)) and interleukin-5 (IL-5) receptor messenger RNA (IL-5R mRNA+) on asthmatic airway inflammation were investigated.

METHODS

Balb/c mice were sensitized and challenged by ovalbumin (OVA) to establish an asthmatic model while control mice were sensitized and exposed to sterile saline. The mice were killed at different time points after being challenged by OVA and sterile saline. Then, bronchoalveolar lavage fluid (BALF), peripheral blood (PB) and bone marrow (BM) were prepared. Eosinophils in PB (PBEOS) and BALF (BALFEOS), nuclear cells in BALF, PB and BM were counted. By flow cytometry, the percentage of CD(34)(+) cells to nucleated cells in PB, BM and the relative number of CD(34)(+) cells in PB (PBCD(34)(+)) and BM (BMCD(34)(+)) were calculated. Immunocytochemistry and in situ hybridization were used to investigate the hematopoietic cells with co-localized expression of CD(34) and IL-5R mRNA in BM (BMCD34+IL-5R mRNA+). The percentage of BMCD34+IL-5R mRNA+ to BMCD(34)(+) was calculated.

RESULTS

Twelve hours after challenge by OVA, BALFEOS and PBEOS in the experimental group were significantly higher than those in the control group (P < 0.01). Twenty-four hours after OVA challenge, BALFEOS, PBEOS and BMCD34+IL-5R mRNA+ were elevated maximally, significantly different from those in the control group (P < 0.01). Forty-eight hours after OVA challenge, BALFEOS and BMCD34+IL-5R mRNA+ were still significantly higher than those of the controls (P < 0.01). The other markers reverted to normal. In 60 mice, BMCD34+IL-5R mRNA+ was closely correlated with the BALEOS, PBEOS, BMCD(34)(+) and BMCD(34)(+) (%) (P < 0.05).

CONCLUSIONS

The amount of CD(34)(+) cells expressing IL-5R mRNA increased in the BM of asthmatic model mice, which favors eosinophilopoiesis and eosinophilic airway inflammation. A signal pathway exists between the lungs and the bone marrow, which is involved in the initiation and maintenance of asthmatic airway inflammation.

In situ synchrotron study of phase transformation behaviors in bulk metallic glass by simultaneous diffraction and small angle scattering

We have used a new approach involving simultaneous diffraction and small angle scattering to study the amorphous-to-crystalline phase transformation in Zr-based bulk metallic glass. In situ, time-resolved data provided the first direct demonstration of a phase separation prior to crystallization. There is evidence that nucleation and growth of the crystalline phase occur in separate stages, with different kinetics. Our data support the view that crystalline nucleation is achieved via short-range diffusion of small atoms (e.g., Ni), whereas the growth is dictated by long-range diffusion.

[A study on the heterogeneous apoptosis of lymphocytes, eosinophils, and neutrophils from peripheral blood of asthmatic patients]

OBJECTIVES

To observe different responsiveness of lymphocytes, eosinophils, and neutrophils from peripheral blood of asthmatic patients to dexamethasone and montelukast-induced apoptosis and to explore the roles of Fas antigen and caspase-3 in the heterogeneity of cell apoptosis.

METHODS

Lymphocytes, eosinophils, and neutrophils were isolated from peripheral blood of 18 asthmatic patients. Cells were incubated in vitro and treated with dexamethasone and leukotriene receptor antagonist montelukast respectively. Cell apoptosis rates and Fas expression rates were examined by flowcytometry whereas caspase-3 levels in these cells were detected by enzyme linked immunosorbent assay (ELISA).

RESULTS

(1) Apoptosis rates: in vitro lymphocytes, eosinophils and neutrophils were compromised of spontaneous apoptosis at lower rates [(6.9 +/- 0.7)%, (31 +/- 11)% and (32 +/- 30)%, respectively]. With induction of dexamethasone, the apoptosis rates were (17.1 +/- 10.8)%, (44 +/- 22)% and (35 +/- 24)%. Montelukast markedly elevated the apoptosis rates of these three cells [(22.5 +/- 17.6)%, (50 +/- 27)% and (55 +/- 22)%, respectively] (compared to control, P < 0.01, < 0.05, > 0.05, respectively). (2) Fas expression: lymphocytes, eosinophils and neutrophils expressed low levels of Fas antigen at baseline [(1.50 +/- 0.07)%, (2.20 +/- 0.10)% and (1.21 +/- 0.09)%, respectively]. Dexamethasone induced Fas antigen expression levels of these cells of (6.58 +/- 2.10)%, (7.52 +/- 3.20)% and (3.24 +/- 2.34)%, and montelukast induced the expression levels of (5.06 +/- 1.66, 7.45 +/- 2.63, 3.03 +/- 2.47, P < 0.01, < 0.01, > 0.05, respectively). (3) caspase-3 levels: lymphocytes, eosinophils and neutrophils expressed constitutive caspase-3 levels of [(3.3 +/- 2.9) ng/L, (5 +/- 4) ng/L and (4.3 +/- 2.6) ng/L, respectively]. The dexamethasone induced caspase-3 levels were (6.7 +/- 3.1) ng/L, (6 +/- 3) ng/L and (3.1 +/- 1.8) ng/L. The montelukast induced levels were (5.2 +/- 3.7) ng/L, (8 +/- 4) ng/L, and (3.1 +/- 2.0) ng/L (compared to control, P < 0.01, < 0.01, > 0.05, respectively). It was demonstrated that dexamethasone and montelukast significantly induced apoptosis of lymphocytes and eosinophils which were assocreased with increased expression of Fas antigen and caspase-3. Dexamethasone was incapable of inducing neutrophils to apoptosis and had no significant effects on Fas expression and caspase-3 activity. Neutrophils underwent significant apoptosis after montelukast treatment, however, the induction was unlikely to be regulated by Fas and caspase-3 pathway.

CONCLUSIONS

In asthmatic inflammatory modulating and effective cells, neutrophils is distinct from lymphocytes and eosinophils in profile of apoptosis induced by glucocorticoids and leukotriene receptor antagonist. The signal pathway contributing neutrophil apoptosis heterogeneity may involve deficient caspase cascade or Fas/FasL.

Glass formation criterion for various glass-forming systems

A conceptual approach to evaluate glass-forming ability for various glass-forming systems has been proposed from a physical metallurgy point of view. It was found that the glass-forming ability for noncrystalline materials was related mainly to two factors, i.e., 1/(T(g)+T(l)) and Tx (wherein Tx is the onset crystallization temperature, T ( g) the glass transition temperature, and T(l) the liquidus temperature), and could be predicated by a unified parameter gamma defined as T(x)/(T(g)+T(l)). This approach was confirmed and validated by experimental data in various glass-forming systems including oxide glasses, cryoprotectants, and metallic glasses.

[Expression of Clara cell secretory protein in airways of rat asthma remodel]

OBJECTIVE

To investigate the mRNA expression of Clara cell secretory protein (CCSP) and the Clara cell number in airways of rat asthma remodel.

METHODS

A rat asthma model was established by sensitization and challenge with ovalbumin (OA). The mRNA expression of CCSP in the lung tissue, the CCSP level in bronchial alveolar lavage fluid (BALF), the thickness of the airways and the number of Clara cells in bronchioles were determined by RT-PCR, image analysis system, dot immunoblotting and immunohistochemistry methods.

RESULTS

There was a progressive decline in CCSP mRNA expression in the lung tissue of rat asthma model group (0.53 +/- 0.07 and 0.49 +/- 0.03, respectively, after 1 week and 2 weeks of challenge) as compared to that of control group (0.67 +/- 0.04). The CCSP levels in BALF of asthma model group (47.00 +/- 6.58 and 45.95 +/- 3.20, respectively, after 1 week and 2 weeks of challenge) were significantly decreased than that of control group (63.08 +/- 2.84, P < 0.01). The ratio(%) of Clara cells was also reduced after challenge. The WAt/Pbm, WAi/Pbm, and WAm/Pbm were significantly increased 2 weeks after OA challenge and were negatively correlated with the level of CCSP and its mRNA expression.

CONCLUSION

The Clara cells and CCSP may participate in the pathogenesis of asthma in the rat asthma remodel.