Oxidative Stress and Apoptosis of Human Brain Microvascular Endothelial Cells Induced by Free Fatty Acids

Damage to endothelial cells is a key event in the pathogenesis of atherosclerosis and vascular disease. This study aimed to determine whether free fatty acids (FFAs) induced oxidative stress and apoptosis in human brain microvascular endothelial cells (HBMVECs) in vitro and, if so, which signalling pathway mediated these effects. After culture in different concentrations of FFAs for 24-72 h, cell viability/proliferation was determined using a cell counting kit, apoptosis was detected by measuring caspase-3 activity and by using annexin V-conjugated fluorescein isothiocyanate/propidium iodide staining, and oxidative stress was evaluated by measuring the levels of reactive oxygen species (ROS) and mitochondrial membrane potential (MMP). The HBMVECs exposed to FFAs showed significantly decreased cell proliferation, increased apoptosis and ROS levels, and decreased MMP. In conclusion, the results showed that high levels of FFAs induced oxidative stress, which damaged HBMVECs and resulted in apoptosis.

First Report of Sooty Blotch and Flyspeck Caused by Species of Dissoconium, Mycosphaerella, and Peltaster on Hawthorn Fruit in China

Sooty blotch and flyspeck (SBFS), a disease complex comprised of as many as 30 putative species of fungi, occurs on the cuticle of pome fruits in moist production regions worldwide, inciting cosmetic damage that causes significant economic losses (1). Chinese hawthorn (Crataegus pinnatifida Bge.) is an economically important tree species in China. Its fruit are sold fresh or dried and are used as a culinary spice as well as an ingredient in Chinese traditional medicine. In October of 2007, Chinese hawthorn fruit exhibiting SBFS signs were sampled from supermarkets in Yangling, Shaanxi Province and Luoyang, Henan Province, China. Thalli directly from the hawthorn fruit were transferred onto potato dextrose agar (PDA) slants under a dissecting microscope and cultured at 22 ± 1°C in darkness. DNA was extracted from pure isolates and the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA (nrDNA) was amplified and sequenced using primers ITS-1F and ITS4 (3). Phylogenetic analysis of the ITS sequences revealed that the 35 isolates generated in this study included five species in three genera: Dissoconium sp. (18 isolates), Mycosphaerella sp. (5 isolates), and Peltaster sp. 1 (4 isolates), Peltaster sp. 2 (4 isolates), and Peltaster sp. 3 (4 isolates). To fulfill Koch's postulates and verify that these fungi could also infest apple fruit, two representative isolates of each putative species were inoculated onto mature intact hawthorn and apple (cv. Fuji) fruit that had been surface disinfested with 75% ethanol and allowed to dry. Inoculum was prepared by comminuting 1-month-old cultures growing on PDA into a suspension of mycelial fragments and conidia (10⁵ to ~10⁶ CFU/ml) in a blender with sterile deionized water (SDW). Each isolate was inoculated on three hawthorn and three apple fruit by using cotton swabs. As controls, two surface-disinfested hawthorn and apple fruit were swabbed with SDW. After the inoculated hawthorn and apple fruit had been incubated in a moist chamber at 22 ± 1°C for 1 month, all inoculated hawthorn and apple fruit exhibited SBFS signs similar to those of the original colonies on hawthorn fruit, but the controls did not. Reservoir hosts have been inferred to play an important role in SBFS by providing the fungi with overwintering habitat and inoculum for infestations on apple. Many reservoir hosts have been reported in the United States and Japan (2). To our knowledge, this is the first report of fungi in the SBFS complex on hawthorn fruit and the first confirmation that fungi growing on hawthorn fruit can produce SBFS signs on apple fruit. These results identify hawthorn as a potential inoculum source for SBFS in apple orchards. References: (1) J. C. Batzer et al. Mycologia 97:1283, 2005. (2) K. Hemnani et al. Phytopathology 98(suppl):S66, 2008. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, 1990.

VITATOPS, the VITAmins TO prevent stroke trial: rationale and design of a randomised trial of B-vitamin therapy in patients with recent transient ischaemic attack or stroke (NCT00097669) (ISRCTN74743444)

BACKGROUND

Epidemiological studies suggest that raised plasma concentrations of total homocysteine (tHcy) may be a common, causal and treatable risk factor for atherothromboembolic ischaemic stroke, dementia and depression. Although tHcy can be lowered effectively with small doses of folic acid, vitamin B(12) and vitamin B(6), it is not known whether lowering tHcy, by means of B vitamin therapy, can prevent stroke and other major atherothromboembolic vascular events.

AIM

To determine whether the addition of B-vitamin supplements (folic acid 2 mg, B(6) 25 mg, B(12) 500 microg) to best medical and surgical management will reduce the combined incidence of stroke, myocardial infarction (MI) and vascular death in patients with recent stroke or transient ischaemic attack (TIA) of the brain or eye.

DESIGN

A prospective, international, multicentre, randomised, double blind, placebo-controlled clinical trial.

SETTING

One hundred and four medical centres in 20 countries on five continents.

SUBJECTS

Eight thousand (6600 recruited as of 5 January, 2006) patients with recent (<7 months) stroke (ischaemic or haemorrhagic) or TIA (brain or eye).

RANDOMISATION

Randomisation and data collection are performed by means of a central telephone service or secure internet site.

INTERVENTION

One tablet daily of either placebo or B vitamins (folic acid 2 mg, B(6) 25 mg, B(12) 500 mug).

PRIMARY OUTCOME

The composite of stroke, MI or death from any vascular cause, whichever occurs first. Outcome and serious adverse events are adjudicated blinded to treatment allocation.

SECONDARY OUTCOMES

TIA, unstable angina, revascularisation procedures, dementia, depression. STATISTICAL POWER: With 8000 patients followed up for a median of 2 years and an annual incidence of the primary outcome of 8% among patients assigned placebo, the study will have at least 80% power to detect a relative reduction of 15% in the incidence of the primary outcome among patients assigned B vitamins (to 6.8%/year), applying a two-tailed level of significance of 5%.

CONCLUSION

VITATOPS aims to recruit and follow-up 8000 patients between 1998 and 2008, and provide a reliable estimate of the safety and effectiveness of folic acid, vitamin B(12), and vitamin B(6) supplementation in reducing recurrent serious vascular events among a wide range of patients with TIA and stroke throughout the world.

Differential regulation of collagen types I and III expression in cardiac fibroblasts by AGEs through TRB3/MAPK signaling pathway

Advanced glycation end products (AGEs) play an important role in collagen deposition in diabetic cardiomyopathy. TRB3, a mammalian homolog of Drosophila tribbles, functions to increase glucose intolerance and regulates cell proliferation. We demonstrated that AGEs induce collagen type I expression but inhibit collagen type III expression, accompanied by increased TRB3 expression. Furthermore, the collagen type I induced byAGEs was down-regulated after inhibition of ERK and p38-MAPK, the collagen type III reduced by AGEs was up-regulated after inhibition of ERK. The expression of collagen types I and III regulated by AGEs through MAPK was partly reversed after treatment with TRB3 siRNA. It suggests that the TRB3/MAPK signaling pathway participates in the regulation of collagen types I and III by AGEs and may provide new therapeutic strategies for diabetic cardiomyopathy.

Microarray analysis of microRNA expression in peripheral blood cells of systemic lupus erythematosus patients

MicroRNAs (miRNAs) are noncoding RNA molecules of 21-24 nt that regulate the expression of target genes in a post-transcriptional manner. Evidence indicates that miRNAs play essential roles in embryogenesis, cell differentiation and pathogenesis of human diseases. This study describes a comparison between the miRNA profile of the systemic lupus erythematosus (SLE) patients and the controls to develop further understanding of the pathogenesis of SLE. Peripheral blood mononuclear cells were isolated from blood samples of 23 SLE patients, 10 idiopathic thrombocytopenic purpura patients and 10 healthy controls. The miRNA microarray chip analysis identified 16 miRNAs differentially expressed in SLE. The chip results were confirmed by northern blot analysis. This work indicates that miRNAs are potential diagnosis biomarkers and probable factors involved in the pathogenesis of SLE.

Expression signatures in lung cancer reveal a profile for EGFR-mutant tumours and identify selective PIK3CA overexpression by gene amplification

The development of targeted therapies creates a need to discriminate tumours accurately by their histological and genetic characteristics. Here, we aim to identify gene expression profiles and single markers that recapitulate the pathological and genetic background of non-small cell lung cancer (NSCLC). We performed cDNA microarray analysis on a series of 69 NSCLCs, with known mutation status for important genes, and six normal lung tissues. Unsupervised cluster analysis segregated normal lungs from lung tumours and lung tumours according to their histopathology and the presence of EGFR mutations. Several transcripts were highly overexpressed (by approximately 20 times) in squamous cell carcinomas (SCCs) relative to adenocarcinomas (ACs) and confirmed by immunohistochemistry in an independent cohort of 75 lung tumours. Expression of 13 genes constituted the most prominent hallmarks of EGFR-mutant tumours, including increased levels of proline dehydrogenase (PRODH) and down-regulation of X-box binding protein 1 (XBP1). No genes were differentially expressed, with a fold change >or= 4 or <or=0.25 and a significance level of 5% false-discovery rate, in tumours carrying mutations of TP53 or KRAS. In addition, we organized gene expression data by the position of each gene in the chromosome and observed a cluster of highly expressed genes in chromosome 3q, including PIK3CA, that was characteristic of SCCs. FISH analysis demonstrated a strong statistically significant association between increased levels of PIK3CA expression in these tumours and gene amplification (p < 0.0001; t-test). In conclusion, histopathological phenotypes and, likely, the presence of EGFR mutations confer lung tumours with a marked pattern of gene expression. Moreover, our cDNA microarray analysis identified increased PIK3CA expression due to gene amplification in lung squamous cell carcinomas: this may represent a marker of sensitivity to therapy with PI3K inhibitors.

Analysis of the human immunodeficiency virus type 1 gp41 membrane proximal external region arrayed on hepatitis B surface antigen particles

Vaccine immunogens derived from the envelope glycoproteins of the human immunodeficiency virus type 1 (HIV-1) that elicit broad neutralizing antibodies remain an elusive goal. The highly conserved 30 amino-acid membrane proximal external region (MPER) of HIV gp41 contains the hydrophobic epitopes for two rare HIV-1 broad cross-reactive neutralizing antibodies, 2F5 and 4E10. Both these antibodies possess relatively hydrophobic HCDR3 loops and demonstrate enhanced binding to their epitopes in the context of the native gp160 precursor envelope glycoprotein by the intimate juxtaposition of a lipid membrane. The hepatitis B surface antigen (HBsAg) S1 protein forms nanoparticles that can be utilized both as an immunogenic array of the MPER and to provide the lipid environment needed for enhanced 2F5 and 4E10 binding. We show that recombinant HBsAg particles with MPER (HBsAg-MPER) appended at the C-terminus of the S1 protein are recognized by 2F5 and 4E10 with high affinity compared to positioning the MPER at the N-terminus or the extracellular loop (ECL) of S1. Addition of C-terminal hydrophobic residues derived from the HIV-1 Env transmembrane region further enhances recognition of the MPER by both 2F5 and 4E10. Delipidation of the HBsAg-MPER particles decreases 2F5 and 4E10 binding and subsequent reconstitution with synthetic lipids restores optimal binding. Inoculation of the particles into small animals raised cross-reactive antibodies that recognize both the MPER and HIV-1 gp160 envelope glycoproteins expressed on the cell surface; however, no neutralizing activity could be detected. Prime:Boost immunization of the HBsAg-MPER particles in sequence with HIV envelope glycoprotein proteoliposomes (Env-PLs) did not raise neutralizing antibodies that could be mapped to the MPER region. However, the Env-PLs did raise anti-Env antibodies that had the ability to neutralize selected HIV-1 isolates. The first generation HBsAg-MPER particles represent a unique means to present HIV-1 envelope glycoprotein neutralizing determinants to the immune system.

Spatial and temporal dynamics of bark beetles in Chinese white pine in Qinling Mountains of Shaanxi Province, China

Spatial and temporal dynamics of bark beetles in single tree trunks of Pinus armandi were studied in Qinling Mountains, Shaanxi Province, China. Ten species of engraver bark beetles attacked from healthy to withered Chinese white pines, but seven species were commonly detected every year in Qinling forest ecosystem. Dendroctonus armandi and Hylurgops longipilis were common species at the lower of trunks, and Ips acuminatus, Polygraphus sinensis, and Pityogenes japonicus primary distributed in the middle of trunks, whereas population densities of Cryphalus lipingensis and C. chinlingensis centralized at the upper trunks and branches of Chinese white pines. On the time series, D. armandi, as a dominant species in Chinese white pines of Qinling forest ecosystem, mainly attacked healthy and weakened trees and cooperated with blue stain fungus that resulted in the declining abruptly resistance and triggered the secondary bark beetles to attack the infected or withered host trees. Attacking and colonizing phenology of bark beetles in Qinling forest ecosystem are caused by complex interactions among spatial and trophic competition and cooperation and exhibit particular spatial and temporal patterns. Our results support the view that competition and cooperation within bark beetles are a critical factor to influence bark beetles spatial and temporal distribution, and stability of bark beetles' ecosystem, D. armandi, I. acuminatus, P. japonicus, P. sinensis, C. lipingensis, C. chinlingensis, and H. longipilis in Chinese white pine of Qinling forest ecosystem.

Distribution and clinical significance of human papillomavirus subtypes in Shenzhen city, People's Republic of China

This study investigated the subtype distribution of the human papillomavirus (HPV) in the patients with condyloma accuminatum (CA) in Shenzhen city, China, and assessed the relationship between different HPV subtypes and cervical neoplasia. Type-specific prevalence and extent of multiple infections were assessed in the genital tract. CA samples collected from the 352 patients in the departments of dermatology and gynecology from the People's Hospital in Shenzhen during 2004-2006, using MY09/11 PCR and reverse dot blot hybridization for genotyping of 9-20 kinds of HPV subtypes. HPV status was studied in relation to the pathologic findings. HPV type diversity was wide. The low-risk HPV subtype 11 and 6 were the main subtypes, and multiple HPV infection rate was about 37% in HPV-positive samples. High-risk HPV (HR-HPV) types (16, 18, 58, 52, and 33) were the main subtypes in the CA of cervix, especially in the advanced stage cervical intraepithelial neoplasia (cervical intraepithelial neoplasia II(+) or above), multiple HR-HPV infection was found in 87% of HPV-positive samples. We conclude that HPV type 6 and 11 were the main subtypes in patients with CA in Shenzhen region, while HPV type 16 and 18 may be one of the main reasons for malignant changes of cervix, but this study cannot prove the association between multiple HPV infection and severity of cervix lesions.

Suppressive effects of antiandrogens, finasteride and flutamide on development of prostatic lesions in a transgenic rat model

Transgenic (TG) rats bearing a probasin promoter/simian virus 40 T antigen (SV40 Tag) construct were treated with antiandrogens to examine their ability to suppress prostate carcinogenesis. Finasteride and flutamide were administered to 10-week-old TG rats five times a week for 2, 5 and 7 weeks. Antiandrogen-treated prostates exhibited atrophic glandular structures with almost no expression of SV40 Tag and only weak signals for androgen receptors. Furthermore, quantitative data for ventral prostate adenocarcinomas showed significant decrease with antiandrogen treatment. Both finasteride and flutamide had the ability to suppress SV40 Tag-driven carcinogenesis through their different antiandrogenic mechanisms, suggesting that this TG model is suitable for exploring the potential of agents to inhibit prostate cancer development.

An Improved Method for Discriminating ECG Signals using Typical Nonlinear Dynamic Parameters and Recurrence Quantification Analysis in Cardiac Disease Therapy

The discrimination of ECG signals using nonlinear dynamic parameters is of crucial importance in the cardiac disease therapy and chaos control for arrhythmia defibrillation in the cardiac system. However, the discrimination results of previous studies using features such as maximal Lyapunov exponent (&#955;<inf>max</inf>) and correlation dimension (D<inf>2</inf>) alone are somewhat limited in recognition rate. In this paper, improved methods for computing &#955;<inf>max</inf>and D<inf>2</inf>are purposed. Another parameter from recurrence quantification analysis is incorporated to the new multi-feature Bayesian classifier with &#955;<inf>max</inf>and D<inf>2</inf>so as to improve the discrimination power. Experimental results have verified the prediction using Fisher discriminant that the maximal vertical line length (V<inf>max</inf>) from recurrence quantification analysis is the best to distinguish different ECG classes. Experimental results using the MIT-BIH Arrhythmia Database show improved and excellent overall accuracy (96.3%), average sensitivity (96.3%) and average specificity (98.15%) for discriminating sinus, premature ventricular contraction and ventricular flutter signals.

Dysfunctional AMPK activity, signalling through mTOR and survival in response to energetic stress in LKB1-deficient lung cancer

LKB1, mutated in Peutz-Jeghers and in sporadic lung tumours, phosphorylates a group of protein kinases named AMP-activated protein kinase (AMPK)-related kinases. Among them is included the AMPK, a sensor of cellular energy status. To investigate the relevance of LKB1 in lung carcinogenesis, we study several lung cancer cells with and without LKB1-inactivating mutations. We report that LKB1-mutant cells are deficient for AMPK activity and refractory to mTOR inhibition upon glucose depletion but not growth-factor deprivation. The requirement for wild-type LKB1 to properly activate AMPK is further demonstrated in genetically modified cancer cells. In addition, LKB1-deficient lung primary tumours had diminished AMPK activity, assessed by complete absence or low level of phosphorylation of its critical substrate, acetyl-CoA carboxylase. We also demonstrate that LKB1 wild-type cells are more resistant to cell death upon glucose withdrawal than their mutant counterparts. Finally, modulation of AMPK activity did not affect PI3K/AKT signalling, an advantage for the potential use of AMPK as a target for cancer therapy in LKB1 wild-type tumours. Thus, sustained abrogation of cell energetic checkpoint control, through alterations at key genes, appear to be an obligatory step in the development of some lung tumours.

A dose escalating, placebo controlled, double blind, single dose and multidose, safety and tolerability study of fontolizumab, a humanised anti-interferon gamma antibody, in patients with moderate to severe Crohn's disease

INTRODUCTION

This study was designed to evaluate the safety of fontolizumab, a humanised anti-interferon gamma antibody, in patients with moderate to severe Crohn's disease (CD).

PATIENTS AND METHODS

Forty five patients with a CD activity index (CDAI) of 250-450 were randomised in a double blind, placebo controlled, dose escalating fashion to receive single doses of fontolizumab (0.1, 1.0, and 4.0 mg/kg) or placebo. By day 29, patients with clinical response were re-randomised to receive three additional doses of one half their initial fontolizumab dose or placebo at four weekly intervals. Primary objectives were safety and tolerability. Secondary outcomes included assessments of immunogenicity, clinical activity, and potential pharmacodynamic surrogates.

RESULTS

Treatment was generally well tolerated. There were slightly more reports of chills, flu-like syndrome, asthenia, nausea, and vomiting in the 1.0 mg and 4.0 mg/kg fontolizumab cohorts. Two serious adverse events rated as worsening of CD occurred under fontolizumab. Antibodies to fontolizumab were confirmed in one patient. No differences in clinical activity parameters were noted between any of the active treatment groups and placebo, with the placebo group having a particularly favourable outcome (60% response and 40% remission). By day 29, a more enhanced decrease in median Crohn's disease endoscopic index of severity (p = 0.02) and serum C reactive protein (p<0.001) was observed in the 4.0 mg/kg (n = 14) fontolizumab cohort compared with placebo (n = 10). Pharmacodynamic effects were observed by immunohistochemistry.

CONCLUSIONS

Fontolizumab was well tolerated with minimal immunogenicity at doses of up to 4.0 mg/kg in patients with CD. A biological activity of fontolizumab is suggested.