Neutrophilic inflammation in severe persistent asthma

Airway inflammation in severe asthma is not well characterized but may involve neutrophils. We have compared induced sputum profiles in patients with asthma of varying severity and normal control subjects. We have also measured exhaled nitric oxide (NO) as a noninvasive marker of inflammation. Asthma severity was based on clinical features before treatment and the minimum medication required to maintain asthma control at the time of sputum induction, and classified as (1) mild: treated with inhaled beta(2)-agonist occasionally (n = 23; FEV(1), 91%; peak expiratory flow (PEF) variability, 10.5%), (2) moderate: requiring medium dose inhaled steroids to maintain control (n = 16; FEV(1), 88%; PEF variability, 9.1%), and (3) severe: despite using inhaled and oral steroids (n = 16; FEV(1), 61%; PEF variability, 36.2%). The asthmatic patients were nonsmokers with evidence of airway hyperresponsiveness or reversible airway obstruction, and free of respiratory tract infection for at least 6 wk. Sputum revealed significantly increased neutrophil numbers in severe asthma (53.0 [38.4- 73.5]%, p < 0.05) compared with mild asthma (35.4 [29.8-46.1]%) and normal control subjects (27.7 [20.6-42.2]%). Interleukin-8 (IL-8) and neutrophil myeloperoxidase (MPO) levels were increased in asthmatic patients, with the highest levels in severe asthma. Eosinophil numbers were increased in both mild and severe asthma, but interleukin-5 (IL-5) levels were highest in mild asthma, whereas eosinophil cationic protein (ECP) levels were highest in severe asthma. Exhaled NO levels were highest in asthmatic untreated with corticosteroids, but there was no significant difference between asthmatics using corticosteroids (Groups 2 and 3), regardless of clinical asthma severity. This confirms the role of eosinophils in asthma but suggests a potential role of neutrophils in more severe asthma.

Overweight, obesity and central obesity in women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND Polycystic ovary syndrome (PCOS) is closely associated with obesity but the prevalence of obesity varies between published studies. The objective of this research was to describe the prevalence of overweight, obesity and central obesity in women with and without PCOS and to assess the confounding effect of ethnicity, geographic regions and the diagnostic criteria of PCOS on the prevalence. METHODS MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting the prevalence of overweight, obesity or central obesity in women with and without PCOS. Data were presented as prevalence (%) and risk ratio (RR) [95% confidence interval (CI)]. Random-effect models were used to calculate pooled RR. RESULTS This systematic review included 106 studies while the meta-analysis included 35 studies (15129 women). Women with PCOS had increased prevalence of overweight [RR (95% CI): 1.95 (1.52, 2.50)], obesity [2.77 (1.88, 4.10)] and central obesity [1.73 (1.31, 2.30)] compared with women without PCOS. The Caucasian women with PCOS had a greater increase in obesity prevalence than the Asian women with PCOS compared with women without PCOS [10.79 (5.36, 21.70) versus 2.31 (1.33, 4.00), P < 0.001 between subgroups). CONCLUSIONS Women with PCOS had a greater risk of overweight, obesity and central obesity. Although our findings support a positive association between obesity and PCOS, our conclusions are limited by the significant heterogeneity between studies and further studies are now required to determine the source of this heterogeneity. Clinical management of PCOS should include the prevention and management of overweight and obesity.

Correlation between exhaled nitric oxide, sputum eosinophils, and methacholine responsiveness in patients with mild asthma

BACKGROUND

Eosinophils in induced sputum and exhaled nitric oxide (NO) are currently used as non-invasive markers in the assessment of airway inflammation in asthma. As both sputum eosinophils (%) and exhaled NO are raised in asthmatic subjects not receiving inhaled steroids and decreased following corticosteroid therapy, a relationship between them is plausible.

METHODS

Exhaled NO was measured by chemiluminescence analyser, sputum induction by 3.5% saline inhalation, and bronchial responsiveness was measured as PC20FEV1 methacholine in 35 stable asthmatic patients using beta 2 agonist alone and the correlation between these non-invasive markers of airway inflammation was studied.

RESULTS

There were significant correlations between exhaled NO and PC20 (r = -0.64), exhaled NO and sputum eosinophils (%) (r = 0.48), and also between sputum eosinophils (%) and PC20 (r = -0.40).

CONCLUSION

The correlation between exhaled NO and PC20 suggests that exhaled NO or the mechanisms leading to its increase may contribute to airway hyperresponsiveness in asthma. Furthermore, the relationship between sputum eosinophils (%), exhaled NO, and PC20 highlight the potential use of eosinophils (%) in induced sputum and exhaled NO to monitor the severity of asthma.

The effect of obesity on polycystic ovary syndrome: a systematic review and meta-analysis

While many women with polycystic ovary syndrome (PCOS) are overweight, obese or centrally obese, the effect of excess weight on the outcomes of PCOS is inconsistent. The review aimed to assess the effects of overweight, obesity and central obesity on the reproductive, metabolic and psychological features of PCOS. MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting outcomes according to body mass index categories or body fat distribution. Data were presented as mean difference or risk ratio (95% confidence interval). This review included 30 eligible studies. Overweight or obese women with PCOS had decreased sex hormone-binding globulin (SHBG), increased total testosterone, free androgen index, hirsutism, fasting glucose, fasting insulin, homeostatic model assessment-insulin resistance index and worsened lipid profile. Obesity significantly worsened all metabolic and reproductive outcomes measured except for hirsutism when compared to normal weight women with PCOS. Overweight women had no differences in total testosterone, hirsutism, total-cholesterol and low-density lipoprotein-cholesterol compared to normal weight women and no differences in SHBG and total testosterone compared to obese women. Central obesity was associated with higher fasting insulin levels. These results suggest that prevention and treatment of obesity is important for the management of PCOS.

Changes in sputum eosinophils predict loss of asthma control

Exacerbations of asthma are likely to be due to an increase in airway inflammation. We have studied noninvasive markers of airway inflammation in asthma exacerbations induced by reducing the dose of inhaled corticosteroids. Following a 2-wk run-in period, mild exacerbations were induced in subjects with stable asthma controlled with medium- to high-dose inhaled corticosteroids (beclomethasone dipropionate >/= 800 microg or equivalent daily) by switching them to budesonide 200 microg daily given from a dry-powder inhaler (Turbohaler). Fifteen subjects were enrolled and were seen twice weekly for 8 wk after steroid reduction. At each visit, exhaled nitric oxide (NO), and methacholine airway responsiveness were measured and spirometry and sputum induction were performed. Mild exacerbation was defined as: (1) a decrease in morning peak expiratory flow (PEF) of >/= 20% but < 30% on at least two consecutive days as compared with the mean for the last 7 d of the run-in period; (2) awakening on two consecutive nights because of asthma; or (3) increased use of a short-acting beta(2)-agonist to eight or more puffs daily. Eight subjects did not develop exacerbations during the 8-wk study, whereas seven subjects developed mild exacerbations at Week 4 (n = 1), Week 6 (n = 1), and Week 8 (n = 5). The only significant difference between these two groups at baseline was a higher baseline sputum eosinophil count in subjects with subsequent exacerbations (p < 0.05). The increases in sputum eosinophils and exhaled NO were correlated with decreases in airway function, including decreases in morning PEF and FEV(1). However, multiple regression analysis suggested that the change in sputum eosinophils is a potentially useful marker in predicting loss of asthma control reflected by loss of airway function.

Characterization of the Shank family of synaptic proteins. Multiple genes, alternative splicing, and differential expression in brain and development

Shank1, Shank2, and Shank3 constitute a family of proteins that may function as molecular scaffolds in the postsynaptic density (PSD). Shank directly interacts with GKAP and Homer, thus potentially bridging the N-methyl-D-aspartate receptor-PSD-95-GKAP complex and the mGluR-Homer complex in synapses (Naisbitt, S., Kim, E., Tu, J. C. , Xiao, B., Sala, S., Valtschanoff, J., Weinberg, R. J., Worley, P. F., and Sheng, M. (1999) Neuron 23, 569-582; Tu, J. C., Xiao, B., Naisbitt, S., Yuan, J. P., Petralia, R. S., Brakeman, P., Doan, A., Aakalu, V. K., Lanahan, A. A., Sheng, M., and Worley, P. F. (1999) Neuron 23, 583-592). Shank contains multiple domains for protein-protein interaction including ankyrin repeats, an SH3 domain, a PSD-95/Dlg/ZO-1 domain, a sterile alpha motif domain, and a proline-rich region. By characterizing Shank cDNA clones and RT-PCR products, we found that there are four sites for alternative splicing in Shank1 and another four sites in Shank2, some of which result in deletion of specific domains of the Shank protein. In addition, the expression of the splice variants is differentially regulated in different regions of rat brain during development. Immunoblot analysis of Shank proteins in rat brain using five different Shank antibodies reveals marked heterogeneity in size (120-240 kDa) and differential spatiotemporal expression. Shank1 immunoreactivity is concentrated at excitatory synaptic sites in adult brain, and the punctate staining of Shank1 is seen in developing rat brains as early as postnatal day 7. These results suggest that alternative splicing in the Shank family may be a mechanism that regulates the molecular structure of Shank and the spectrum of Shank-interacting proteins in the PSDs of adult and developing brain.

Inhaled corticosteroids increase interleukin-10 but reduce macrophage inflammatory protein-1alpha, granulocyte-macrophage colony-stimulating factor, and interferon-gamma release from alveolar macrophages in asthma

We determined the effect of inhaled corticosteroid, budesonide, on the release of the anti-inflammatory cytokine, interleukin-10 (IL-10), and of pro-inflammatory cytokines, macrophage inflammatory protein-1alpha (MIP-1alpha), interferon-gamma (IFN-gamma), and granulocyte-macrophage colony-stimulating factor (GM-CSF), from blood monocytes and alveolar macrophages of mild asthmatic subjects in a double-blind, cross-over, placebo-controlled study. Budesonide reduced bronchial hyperresponsiveness and improved baseline FEV1. Alveolar macrophages were obtained by bronchoalveolar lavage performed at the end of each treatment phase. IL-10 from blood monocytes was not altered, but both IL-10 mRNA and protein expression from alveolar macrophages stimulated by lipopolysaccharide and IL-1beta were increased after corticosteroid therapy. By contrast, alveolar macrophages released significantly less MIP-1alpha, IFN-gamma, and GM-CSF after steroid treatment. In comparison to alveolar macrophages from normal nonasthmatic volunteers, those from asthmatic patients released more MIP-1alpha, IFN-gamma, and GM-CSF but lower amounts of IL-10 particularly at baseline and after IL-1beta stimulation. The ability of steroids to inhibit pro-inflammatory cytokines but to enhance the anti-inflammatory cytokine such as IL-10 may contribute to their beneficial actions in asthma. Asthma is characterized by alveolar macrophages exhibiting both an enhanced capacity to release pro-inflammatory cytokines and a reduced capacity to produce IL-10.

Protease-activated receptors in human airways: upregulation of PAR-2 in respiratory epithelium from patients with asthma

BACKGROUND

Protease-activated receptors (PARs), which are G protein-coupled receptors that are activated after proteolytic cleavage of the amino terminus of the receptor, are likely to play a major role in airway inflammation. PARs are activated by endogenous proteases, including thrombin (PAR-1, -3, and -4) and tryptase (PAR-2 and -4), both of which are present in inflamed airways.

OBJECTIVE

The purpose of this study was to compare the expression and distribution of PARs in biopsy specimens obtained from asthmatic and normal subjects and to examine the effect of inhaled corticosteroids on PAR expression.

METHODS

Biopsy specimens were obtained from 10 normal and 20 asthmatic patients, and sections were stained for PAR-1, -2, -3, and -4 through use of specific antibodies. Staining was scored semiquantitatively for both intensity and distribution.

RESULTS

Staining for all PARs was seen on the epithelium and smooth muscle in biopsy specimens from both normal and asthmatic subjects. In the epithelium, PAR-1 and -3 staining appeared to be apically concentrated, whereas PAR-2 and -4 staining was more diffuse. In normal subjects, epithelial staining intensity of PAR-1 and -3 was significantly greater than for PAR-4 (P < .05). Staining for PAR-1, -3, and -4 in biopsy specimens from asthmatic subjects was similar to that in specimens from normal subjects, irrespective of whether the former were using inhaled corticosteroids. However, PAR-2 staining in asthmatic epithelium was significantly increased in comparison with normal epithelium. Expression of PARs in airway smooth muscle did not differ between groups.

CONCLUSION

Asthma per se is associated with increased PAR-2 expression in bronchial epithelium. Importantly, staining was not influenced by inhaled corticosteroids. These results suggest that PAR-2 might be involved in airway inflammation.

Effect of differing doses of inhaled budesonide on markers of airway inflammation in patients with mild asthma

BACKGROUND

It is desirable to prescribe the minimal effective dose of inhaled steroids to control asthma. To ensure that inflammation is suppressed whilst using the lowest possible dose, a sensitive and specific method for assessing airway inflammation is needed.

METHODS

The usefulness of exhaled nitric oxide (NO), sputum eosinophils, and methacholine airway responsiveness (PC20) for monitoring airway inflammatory changes following four weeks of treatment with an inhaled corticosteroid (budesonide via Turbohaler) were compared. Mild stable steroid naive asthmatic subjects were randomised into two double blind, placebo controlled studies. The first was a parallel group study involving three groups receiving either 100 micrograms/day budesonide (n = 8), 400 micrograms/day budesonide (n = 7), or a matched placebo (n = 6). The second was a crossover study involving 10 subjects randomised to receive 1600 micrograms budesonide or placebo. The groups were matched with respect to age, PC20, baseline FEV1 (% predicted), exhaled NO, and sputum eosinophilia.

RESULTS

There were significant improvements in FEV1 following 400 micrograms and 1600 micrograms budesonide (11.3% and 6.5%, respectively, p < 0.05). This was accompanied by significant reductions in eosinophil numbers in induced sputum (0.7 and 0.9 fold, p < 0.05). However, levels of exhaled NO were reduced following each budesonide dose while PC20 was improved only with 1600 micrograms budesonide. These results suggest that exhaled NO and PC20 may not reflect the control of airway inflammation as accurately as the number of eosinophils in sputum. There were dose dependent changes in exhaled NO, sputum eosinophils, and PC20 to inhaled budesonide but a plateau response of exhaled NO was found at a dose of 400 micrograms daily.

CONCLUSION

Monitoring the number of eosinophils in induced sputum may be the most accurate guide to establish the minimum dose of inhaled steroids needed to control inflammation. This, however, requires further studies involving a larger number of patients.

Type 2 diabetes-associated genetic variants discovered in the recent genome-wide association studies are related to gestational diabetes mellitus in the Korean population

AIMS/HYPOTHESIS

New genetic variants associated with susceptibility to type 2 diabetes mellitus have been discovered in recent genome-wide association (GWA) studies. The aim of the present study was to examine the association between these diabetogenic variants and gestational diabetes mellitus (GDM).

METHODS

The study included 869 Korean women with GDM and 345 female and 287 male Korean non-diabetic controls. We genotyped the single nucleotide polymorphisms (SNPs) rs7756992 and rs7754840 in CDKAL1; rs564398, rs1333040, rs10757278 and rs10811661 in the CDKN2A-CDKN2B region; rs8050136 in FTO; rs1111875, rs5015480 and rs7923837 in HHEX; rs4402960 in IGF2BP2; and rs13266634 in SLC30A8. In addition, rs7903146 and rs12255372 in TCF7L2; rs5215 and rs5219 in KCNJ11; and rs3856806 and rs1801282 in PPARG were genotyped. The genotype frequencies in the GDM patients were compared with those in the non-diabetic controls.

RESULTS

Compared with controls (men and women combined), GDM was associated with rs7756992 and rs7754840 (OR 1.55, 95% CI 1.34-1.79, p = 4.17 x 10(-9)) in CDKAL1; rs10811661 (OR 1.49, 95% CI 1.29-1.72, p = 1.05 x 10(-7)) in the CDKN2A-CDKN2B region; rs1111875 (OR 1.27, 95% CI 1.09-1.49, p = 0.003), rs5015480, and rs7923837 in HHEX; rs4402960 (OR 1.18, 95% CI 1.01-1.38, p = 0.03) in IGF2BP2; rs13266634 (OR 1.24, 95% CI 1.07-1.43, p = 0.005) in SLC30A8; and rs7903146 (OR 1.58, 95% CI 1.03-2.43, p = 0.038) in TCF7L2. The risk alleles of the SNPs rs7756992 and rs7754840 in CDKAL1; rs10811661 in the CDKN2A-CDKN2B region; and rs1111875, rs5015480 and rs7923837 in HHEX were associated with significant decreases in the insulin AUC during a 100 g OGTT performed at the time of diagnosis of GDM.

CONCLUSIONS/INTERPRETATION

Some of the type 2 diabetes-associated genetic variants that were discovered in the recent GWA studies are also associated with GDM in Koreans.

Stem cells in liver regeneration, fibrosis and cancer: the good, the bad and the ugly

The worldwide shortage of donor livers to transplant end stage liver disease patients has prompted the search for alternative cell therapies for intractable liver diseases, such as acute liver failure, cirrhosis and hepatocellular carcinoma (HCC). Under normal circumstances the liver undergoes a low rate of hepatocyte 'wear and tear' renewal, but can mount a brisk regenerative response to the acute loss of two-thirds or more of the parenchymal mass. A body of evidence favours placement of a stem cell niche in the periportal regions, although the identity of such stem cells in rodents and man is far from clear. In animal models of liver disease, adopting strategies to provide a selective advantage for transplanted hepatocytes has proved highly effective in repopulating recipient livers, but the poor success of today's hepatocyte transplants can be attributed to the lack of a clinically applicable procedure to force a similar repopulation of the human liver. The activation of bipotential hepatic progenitor cells (HPCs) is clearly vital for survival in many cases of acute liver failure, and the signals that promote such reactions are being elucidated. Bone marrow cells (BMCs) make, at best, a trivial contribution to hepatocyte replacement after damage, but other BMCs contribute to the hepatic collagen-producing cell population, resulting in fibrotic disease; paradoxically, BMC transplantation may help alleviate established fibrotic disease. HCC may have its origins in either hepatocytes or HPCs, and HCCs, like other solid tumours appear to be sustained by a minority population of cancer stem cells.

The global burden of occupationally related low back pain: estimates from the Global Burden of Disease 2010 study

OBJECTIVES

The study was part of the Global Burden of Disease 2010 study and aimed to quantify the burden arising from low back pain (LBP) due to occupational exposure to ergonomic risk factors.

METHODS

Exposure prevalence was based on occupation distribution; estimates of relative risk came from a meta-analysis of relevant published literature. The work-related burden was estimated as disability-adjusted life years (DALYs). Estimates were made for each of 21 world regions and 187 countries, separately for 1990 and 2010 using consistent methods.

RESULTS

Worldwide, LBP arising from ergonomic exposures at work was estimated to cause 21.7 million DALYs in 2010. The overall population attributable fraction was 26%, varying considerably with age, sex and region. 62% of LBP DALYs were in males-the largest numbers were in persons aged 35-55 years. The highest relative risk (3.7) was in the agricultural sector. The largest number of DALYs occurred in East Asia and South Asia, but on a per capita basis the biggest burden was in Oceania. There was a 22% increase in overall LBP DALYs arising from occupational exposures between 1990 and 2010 due to population growth; rates dropped by 14% over the same period.

CONCLUSIONS

LBP arising from ergonomic exposures at work is an important cause of disability. There is a need for improved information on exposure distributions and relative risks, particularly in developing countries.

Effect of inhaled budesonide on lung function and airway inflammation. Assessment by various inflammatory markers in mild asthma

In a double-blind, cross-over study, we examined the effect of inhaled budesonide (800 microgram twice daily via Turbohaler) on lung function and various markers of airway inflammation including airway responsiveness to methacholine (PC20), exhaled nitric oxide (NO), eosinophils in induced sputum, bronchoalveolar lavage (BAL), and airway biopsies from 14 patients with mild asthma needing beta2- agonist therapy only. After inhaled steroids, there was a significant increase in FEV1 and PC20, and reduction in exhaled NO. Eosinophils in induced sputum and airway biopsy sections were also significantly decreased, although BAL eosinophil counts remained unchanged. At baseline, significant correlations were observed between exhaled NO and PC20 methacholine (r = 0.64, p < 0.05), exhaled NO and peak expiratory flow rate (PEFR) variability (r = 0. 65, p < 0.05), sputum eosinophils and FEV1 (r = -0.63, p = 0.05), and sputum eosinophils and log PC20 methacholine (r = -0.67, p < 0. 05). After treatment with inhaled steroids, there was a significant correlation between eosinophils in biopsy sections, and BAL, with log PC20 methacholine. It is likely that these parameters represent different aspects of the inflammatory process, which are all inhibited by inhaled steroids.

Combined use of exhaled hydrogen peroxide and nitric oxide in monitoring asthma

Oxidative stress contributes to airway inflammation and exhaled hydrogen peroxide (H2O2) and nitric oxide (NO) are elevated in asthmatic patients. We determined the concentrations of expired H2O2 and NO in 116 asthmatic (72 stable steroid-naive, 30 stable steroid-treated, and 14 severe steroid-treated unstable patients) and in 35 healthy subjects, and studied the relation between exhaled H2O2, NO, FEV1, airway responsiveness, and eosinophils in induced sputum. Both exhaled H2O2 and NO levels were elevated in steroid-naive asthmatic patients compared with normal subjects (0.72 +/- 0.06 versus 0.27 +/- 0.04 microM and 29 +/- 1.9 versus 6.5 +/- 0. 32 ppb, respectively; p < 0.001) and were reduced in stable steroid-treated patients (0.43 +/- 0.08 microM, p < 0.05, and 9.9 +/- 0.97 ppb, p < 0.001). In unstable steroid-treated asthmatics, however, H2O2 levels were increased, but exhaled NO levels were low (0.78 +/- 0.16 microM and 6.7 +/- 1.0 ppb, respectively). There was a correlation between expired H2O2, sputum eosinophils and airway hyperresponsiveness (methacholine PC20). Exhaled NO also correlated with sputum eosinophils, but not with airway hyperresponsiveness. Our findings indicate that measurement of expired H2O2 and NO in asthmatic patients provides complementary data for monitoring of disease activity.

Balance of matrix metalloprotease-9 and tissue inhibitor of metalloprotease-1 from alveolar macrophages in cigarette smokers. Regulation by interleukin-10

An imbalance between proteases and antiproteases may play a role in emphysema, which is characterized by increased degradation of extracellular matrix, and in airway remodeling in chronic bronchitis and asthma, in which there is increased collagen deposition. We assessed the effect of smoking on release of matrix metalloprotease-9 (MMP-9) and of its inhibitor, tissue inhibitor of metalloprotease-1 (TIMP-1), from alveolar macrophages, and determined the effects of proinflammatory (interleukin [IL]-1beta and lipopolysaccharide [LPS]) and antiinflammatory (IL-10) stimuli on the release of MMP-9 and TIMP-1. We performed bronchoalveolar lavage in 11 smokers and 11 nonsmokers, and cultured airway macrophages in the presence of control medium, IL-1beta, and LPS. Airway macrophages from smokers released greater amounts of MMP-9 and TIMP-1 at baseline and in response to IL-1beta and LPS than did those of nonsmokers. Airway macrophages from smokers produced more TNF-alpha and IL-10. IL-10 increased TIMP-1 release without modifying that of MMP-9, leading to a decrease in the MMP-9 to TIMP-1 ratio. Anti-IL-10 antibody had no effect on MMP-9 production induced by LPS. We conclude that the release of proteases and antiproteases by airway macrophages is increased in cigarette smokers, and can be regulated by exogenous IL-10.

Fabrication and characterization of graphene hydrogel via hydrothermal approach as a scaffold for preliminary study of cell growth

BACKGROUND

Three-dimensional assembly of graphene hydrogel is rapidly attracting the interest of researchers because of its wide range of applications in energy storage, electronics, electrochemistry, and waste water treatment. Information on the use of graphene hydrogel for biological purposes is lacking, so we conducted a preliminary study to determine the suitability of graphene hydrogel as a substrate for cell growth, which could potentially be used as building blocks for biomolecules and tissue engineering applications.

METHODS

A three-dimensional structure of graphene hydrogel was prepared via a simple hydrothermal method using two-dimensional large-area graphene oxide nanosheets as a precursor.

RESULTS

The concentration and lateral size of the graphene oxide nanosheets influenced the structure of the hydrogel. With larger-area graphene oxide nanosheets, the graphene hydrogel could be formed at a lower concentration. X-ray diffraction patterns revealed that the oxide functional groups on the graphene oxide nanosheets were reduced after hydrothermal treatment. The three-dimensional graphene hydrogel matrix was used as a scaffold for proliferation of a MG63 cell line.

CONCLUSION

Guided filopodia protrusions of MG63 on the hydrogel were observed on the third day of cell culture, demonstrating compatibility of the graphene hydrogel structure for bioapplications.

Metabolic syndrome in polycystic ovary syndrome: a systematic review, meta-analysis and meta-regression

Women with polycystic ovary syndrome (PCOS) have increased risk of metabolic syndrome. The relative contribution of clinical, demographic or biochemical factors to metabolic syndrome in PCOS is not known. A literature search was conducted in MEDLINE, CINAHL, EMBASE and clinical trial registries. Of 4530 studies reviewed, 59 were included in the systematic review and 27 in the meta-analysis and meta-regression. In good and fair quality studies, women with PCOS had an overall increased prevalence of metabolic syndrome (odds ratio, OR 3.35, 95% confidence interval, CI 2.44, 4.59). Increased prevalence of metabolic syndrome occurred in overweight or obese women with PCOS (OR 1.88, 95% 1.16, 3.04) but not in lean women (OR 1.45, 95% CI 0.35, 6.12). In meta-regression analyses, the markers of metabolic syndrome diagnostic criteria (waist circumference, high-density lipoprotein cholesterol, triglyceride, blood pressure), BMI, glucose tolerance (2-hr oral glucose tolerance test) and surrogate markers of insulin resistance (HOMA-IR) but not markers of reproductive dysfunction (sex hormone binding globulin, testosterone, PCOS phenotypes) contributed significantly to the heterogeneity in the prevalence of metabolic syndrome. Women with PCOS have increased risk of metabolic syndrome which was associated with obesity and metabolic features but not with indices of hyperandrogenism.

Gleevec (STI571) influences metabolic enzyme activities and glucose carbon flow toward nucleic acid and fatty acid synthesis in myeloid tumor cells

Chronic myeloid leukemia cells contain a constitutively active Bcr-Abl tyrosine kinase, the target protein of Gleevec (STI571) phenylaminopyrimidine class protein kinase inhibitor. Here we provide evidence for metabolic phenotypic changes in cultured K562 human myeloid blast cells after treatment with increasing doses of STI571 using [1,2-13C2]glucose as the single tracer and biological mass spectrometry. In response to 0.68 and 6.8 microm STI571, proliferation of Bcr-Abl-positive K562 cells showed a 57% and 74% decrease, respectively, whereas glucose label incorporation into RNA decreased by 13.4% and 30.1%, respectively, through direct glucose oxidation, as indicated by the decrease in the m1/Sigma(m)n ratio in RNA. Based on the in vitro proliferation data, the IC50 of STI571 in K562 cultures is 0.56 microm. The decrease in 13C label incorporation into RNA ribose was accompanied by a significant fall in hexokinase and glucose-6-phosphate 1-dehydrogenase activities. The activity of transketolase, the enzyme responsible for nonoxidative ribose synthesis in the pentose cycle, was less affected, and there was a relative increase in glucose carbon incorporation into RNA through nonoxidative synthesis as indicated by the increase in the m2/Sigma(m)n ratio in RNA. The restricted use of glucose carbons for de novo nucleic acid and fatty acid synthesis by altering metabolic enzyme activities and pathway carbon flux of the pentose cycle constitutes the underlying mechanism by which STI571 inhibits leukemia cell glucose substrate utilization and growth. The administration of specific hexokinase/glucose-6-phosphate 1-dehydrogenase inhibitor anti-metabolite substrates or competitive enzyme inhibitor compounds, alone or in combination, should be explored for the treatment of STI571-resistant advanced leukemias as well as that of Bcr-Abl-negative human malignancies.

Progressive and spatially differentiated stability of microtubules in developing neuronal cells

The establishment of neural circuits requires both stable and plastic properties in the neuronal cytoskeleton. In this study we show that properties of stability and lability reside in microtubules and these are governed by cellular differentiation and intracellular location. After culture for 3, 7, and 14 d in nerve growth factor-containing medium, PC-12 cells were microinjected with X-rhodamine-labeled tubulin. 8-24 h later, cells were photobleached with a laser microbeam at the cell body, neurite shaft, and growth cone. Replacement of fluorescence in bleached zones was monitored by digital video microscopy. In 3-d cultures, fluorescence recovery in all regions occurred by 26 +/- 17 min. Similarly, in older cultures, complete fluorescence recovery at the cell body and growth cone occurred by 10-30 min. However, in neurite shafts, fluorescence recovery was markedly slower (71 +/- 48 min for 7-d and 201 +/- 94 min for 14-d cultures). This progressive increase in the stability of microtubules in the neurite shafts correlated with an increase of acetylated microtubules. Acetylated microtubules were present specifically in the neurite shaft and not in the regions of fast microtubule turnover, the cell body and growth cone. During the recovery of fluorescence, bleached zones did not move with respect to the cell body. We conclude that the microtubule component of the neuronal cytoskeleton is differentially dynamic but stationary.

Expression and release of interleukin-8 by human airway smooth muscle cells: inhibition by Th-2 cytokines and corticosteroids

Interleukin (IL)-8 is a C-X-C chemokine that potently chemoattracts and activates neutrophils. We determined whether IL-8 could be produced by human airway smooth muscle cells in culture and examined its regulation. TNF-alpha stimulated IL-8 mRNA expression and protein release in a time- and dose-dependent manner, whereas IFN-gamma alone had no effect. Both cytokines together did not induce greater IL-8 release compared to TNF-alpha alone. IL-1beta was more potent in inducing IL-8 release and, together with TNF-alpha, there was a synergistic augmentation of IL-8 release. IL-8 release induced by TNF-alpha and IFN-gamma was partly inhibited by the Th-2-derived cytokines IL-4, IL-10, and IL-13, as well as by dexamethasone. In addition to its contractile responses, airway smooth muscle cells have synthetic and secretory potential with the release of IL-8 and subsequent recruitment and activation of neutrophils in the airways. Release of IL-8 can be modulated by Th-2-derived cytokines and corticosteroids.

Steady state dynamics of intermediate filament networks

We have conducted experiments to examine the dynamic exchange between subunit and polymer of vimentin intermediate filaments (IF) at steady state through the use of xrhodamine-labeled vimentin in fluorescence recovery after photobleaching (FRAP) analysis. The xrhodamine-vimentin incorporated into the endogenous vimentin IF network after microinjection into fibroblasts and could be visualized with a cooled charge-coupled device (CCD) camera and digital imaging fluorescence microscopy. Bar shaped regions were bleached in the fluorescent IF network using a beam from an argon ion laser and the cells were monitored at various times after bleaching to assess recovery of fluorescence in the bleached zones. We determined that bleached vimentin fibers can recover their fluorescence over relatively short time periods. Vimentin fibers in living cells also can exhibit significant movements, but the recovery of fluorescence was not dependent upon movement of fibers. Fluorescence recovery within individual fibers did not exhibit any marked polarity and was most consistent with a steady state exchange of vimentin subunits along the lengths of IF.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Osteocyte shape is dependent on actin filaments and osteocyte processes are unique actin-rich projections

Osteocytes are derived from a select group of osteoblasts that have undergone a final differentiation. Due to their inaccessibility when embedded in the bone matrix, very little is known about the osteocyte cytoskeleton. This study provides an extensive analysis of the osteocyte cytoskeleton, based on the successful isolation of osteocytes from 16-day embryonic chick calvariae. We used OB7.3, a chicken osteocyte-specific monoclonal antibody, to confirm the osteocytic phenotype of the isolated cells and established culture conditions to promote growth of cells that most resemble osteocytes in vivo. Immunofluorescence staining with antitubulin, antivimentin, and antiactin showed the relative distribution of the microtubules, intermediate filaments, and actin filaments in both osteocyte cell body and processes. Field emission scanning electron microscopy revealed the three-dimensional relationships of the cytoskeletal elements and a unique organization of actin bundles that spanned the cell body and osteocyte processes. When combined with drug studies, these experiments demonstrate that actin filaments are crucial for the maintenance of osteocyte shape. Furthermore, we identified two actin-bundling proteins, alpha-actinin and fimbrin, in osteocyte processes. The prominence and unique distribution of fimbrin in osteocyte processes provides the possibility of its use as an intracellular marker to distinguish osteocytes from osteoblasts.