Role of caveolin-1 in the pathogenesis of tissue fibrosis by keloid-derived fibroblasts in vitro

BACKGROUND

Recent studies have suggested that caveolin-1 (cav-1) plays an important role in the regulation of transforming growth factor (TGF)-β1 signalling and participates in the pathogenesis of tissue fibrosis. However, its effects on dermal fibrosis keloids are unknown.

OBJECTIVES

To investigate the effect of cav-1 in the pathogenesis of tissue fibrosis by keloid fibroblasts.

METHODS

Keloid fibroblasts were cultured and exposed to different concentrations of cav-1 cell-permeable peptides (cav-1p) in the presence of TGF-β1. Keloid fibroblast phenotypes and protein production were analysed by real-time reverse transcriptase-polymerase chain reaction, Western blot, and multiplex enzyme-linked immunosorbent assay techniques. The effect of cav-1p on cell viability was evaluated by MTT assay.

RESULTS

Cav-1 was markedly decreased in the keloid-derived fibroblasts. Moreover, cav-1p significantly reduced TGF-β receptor type I levels and Smad2/3 phosphorylation in response to added TGF-β1. Additionally, TGF-β1 decreased cav-1 expression in human skin fibroblasts. Cav-1 was able to suppress TGF-β1-induced extracellular matrix production in cultured keloid fibroblasts through regulation of the mitogen-activated protein kinase pathway.

CONCLUSIONS

Cav-1 appears to participate in the pathogenesis of tissue fibrosis in keloid. Restoration of cav-1 function by treatment with a cell-permeable peptide corresponding to the cav-1 scaffolding domain may be a novel therapeutic approach in keloid.

The Golden Potato Cyst Nematode Globodera rostochiensis Pathotype Ro1 in the Saint-Amable Regulated Area in Quebec, Canada

The golden potato cyst nematode, Globodera rostochiensis (Wollenweber, 1923) Behren, is an economically important parasite of potato (Solanum tuberosum L. subsp. tuberosum) and is recognized as a quarantine pest internationally (2). This pest attacks potato plants and causes stunting of the haulm and the root system, leaf yellowing, and tuber yield losses (2). The pathotype scheme proposed by Kort et al. distinguishes five pathotypes (Ro1, Ro2, Ro3, Ro4, and Ro5) of G. rostochiensis using differential Solanum clones (1). Several resistance genes and quantitative trait loci (QTL) that have been identified in wild Solanum species confer resistance to different G. rostochiensis pathotypes and have been introgressed into commercial potato cultivars (2). Determining G. rostochiensis pathotype(s) is essential to implement efficient management strategies, which include using resistant potato varieties. G. rostochiensis was discovered in the municipality of Saint-Amable, Quebec (QC), Canada in 2006 (3) and was subsequently characterized (4). In this study, cysts were collected from 11 representative infested fields and confirmed to be G. rostochiensis (3). The pathotypes of these nematodes were assessed on seven differential clones (S. tuberosum subsp. tuberosum cv. Desiree, S. tuberosum × S. andigena cv. Maris Piper, S. kurtzianum hybrid 60.21.19, S. vernei hybrid 62.33.3, S. vernei hybrid 58.1642/4, S. vernei hybrid 65.346/19, and S. multidissectum hybrid P55/7) in 2007 and 2009. Briefly, in each 1-liter plastic pot containing 907 g (2 lbs) of soil (3:1 loam/grit v v-1), a single differential Solanum clone was planted and 15 cysts from 1 of 11 fields were inoculated. Five replicates were set up for each Solanum-nematode combination and the pots were arranged in a completely randomized design in a greenhouse at 22°C with a 16-h light period per day. Nine weeks after inoculation, cysts were extracted from each pot and counted. Reproduction factor (Rf) for each replicate was calculated (Rf = Pf/Pi; Pf is the final cyst number and Pi is the initial cyst number added to each pot). Rf values were used to categorize the differential clones into two groups, "susceptible" leading to increase in nematode numbers (Rf > 1) and "resistant" resulting in decrease in nematode numbers (Rf ≤ 1) (1). Our results in 2007 and 2009 were consistent and the pathotype of the nematodes collected from all the fields were identified as Ro1. To our knowledge, this is the first time that the pathotype of G. rostochiensis in the Saint-Amable regulated area was identified. Accordingly, potato cultivars carrying genes or QTL resistant to G. rostochiensis pathotype Ro1 can be used to reduce the nematode numbers in infested fields in the Saint-Amable area, QC. References: (1) J. Kort et al. Nematologica 23:333, 1977. (2) R. J. Marks and B. B. Brodie. Potato Cyst Nematodes: Biology, Distribution, and Control. 1st ed. CAB International, Wallingford, 1998. (3) F. Sun et al. Plant Dis. 91:908, 2007. (4) Q. Yu et al. Can. J. Plant Pathol. 32:264, 2010.

First Record of Trichodorus primitivus and Morphological and Molecular Identification of Longidorus elongatus from Canada

During July 2008, sandy loam soil samples were collected near the rhizosphere of Kentucky bluegrass (Poa pratensis L.) and tall fescue (Festuca arundinacea Schreb.) at a depth of 15 to 20 cm from Caledonia Park, Toronto, Canada. Samples were suspended in water and nematodes were collected on sieves with 250- and 74-μm openings. Among the nematodes recovered were one species of Longidorus Micoletzky, 1922 (4) and one species of Trichodorus Cobb, 1913. The Trichodorus species (2), was identified as T. primitivus (de Man, 1880) Micoletzky, 1922, in which females have rod-like sclerotized pieces parallel to the vagina lumen, each with dimensions of 3.1 × 1.2 μm and at a distance of 2 to 3 μm from each other; and males have spicules with a wide nonoffset capitulum and very narrow blade, three ventromedian cervical papillae (CP), and three precloacal supplements with the anterior one at the level of the capitulum of retracted spicules. Males showed unusual variation in the position of CP2 (i.e., posterior to the onchiostyle region, except for one specimen with CP2 located within the posterior onchiostyle region, which is typical for the species). The morphometric data for nine males are: L, 665 to 805 μm; a, 23.0 to 27.5; b, 3.7 to 5.2; c, 46 to 56; onchiostyle, 47 to 52 μm; and spicules, 32.5 to 40.5 μm. Measurements for 13 females are: L, 630 to 775 μm; a, 20.5 to 24.8; b, 3.5 to 5.5; c, 75.5 to 158.5; and V, 54 to 61%. To our knowledge, this is the first report of T. primitivus in Canada. According to Chen et al. (1), the Longidorus species was identified as L. elongatus (de Man, 1876) Micoletzky, 1922 (3). The morphometric data for females (n = 13) are: L, 5.1 to 6.0 mm; a, 78.5 to 106.5; b, 11.5 to 13.5; c, 86.0 to 120.5; V, 45.5 to 53.0%; odontostyle, 79 to 91 μm; odontophore, 57.5 to 66.5 μm; and tail length, 44.5 to 59.0 μm. Males were not found. Four juvenile stages were identified. J1 (n = 2) with a body length of 1.1, 1.2 mm and replacement/functional odontostyle 59, 59/53.5, 54.5 μm, J2 (n = 2) with L: 1.7, 2.0 mm and replacement/functional odontostyle 62.5, 68.0/58.7 μm, 59.0, J3 (n = 2): L: 2.8, 3.0 mm and replacement/functional odontostyle 76.5, 77/66.5, 67.0 μm and J4 (n = 2) with L: 3.6, 3.8 mm and replacement/functional odontostyle 87.0, 90.5/75.0, 77.5 μm. Due to large morphometric overlap in Longidorus species identification, 2,472 bp of the near full-length 18S and the internal transcribed spacer 1 region of rDNA (Accession No. GU199044) were sequenced. The Blastn search of the partial 18S revealed 100% identity with a population of L. elongatus from Scotland (GenBank No. AY687992, 1,707 bp compared), 99% identity (3 bp difference, 1,707 bp compared) with a population of L. elongatus from Iran (EU503141) and 99% identity (4 bp difference, 1,707 bp compared) with a population of L. elongatus (AF036594, sample location unknown). A Blastn search of the 18S and ITS region revealed only 1 to 3 bp differences with two populations of L. elongatus from Switzerland (AJ549986 and AJ549987) and a population of L. elongatus (AF511417) from Scotland. These molecular data further confirmed the identity of the population from Canada to be L. elongatus. References: (1) Q. Chen et al. Fundam. Appl. Nematol. 20:15, 1997. (2) W. Decraemer. Kluwer Academic Publishers, Dordrecht, the Netherlands, 1995. (3) J. G. de Man. Tijdschr. Ned. Dierk. Ver. 2:78, 1876. (4) H. Micoletzky. Archiv. Naturgesch. 87:1, 1922.

A clinical trial assessing the safety and efficacy of the CB1R inverse agonist taranabant in obese and overweight patients: low-dose study

OBJECTIVE

To evaluate the weight loss efficacy, safety and tolerability of taranabant, a CB1R inverse agonist, in obese and overweight patients.

DESIGN

Multicenter, double-blind, randomized, placebo-controlled study.

SUBJECTS

Patients >or=18 years old, BMI 27-43 kg m(-2), were randomized to placebo (n=209) or taranabant 0.5 mg (n=207), 1 mg (n=208) or 2 mg given orally once daily (n=417) for 52 weeks.

MEASUREMENTS

Key efficacy measurements included body weight (BW), waist circumference (WC), lipid endpoints and glycemic endpoints.

RESULTS

Based on a last observation carried forward analysis of the all-patients-treated population, mean change in BW for taranabant 0.5, 1, and 2 mg and placebo was -5.4, -5.3, -6.7 and -1.7 kg, respectively (P<0.001 for all doses vs placebo). The proportions of patients who lost at least 5 and 10% of their baseline BW at week 52 were significantly higher for all taranabant doses vs placebo (P<0.001 for all doses). Reductions in WC, percentage of body fat, and triglycerides were significant for taranabant 2 mg and in triglycerides for taranabant 1 mg vs placebo. There was no effect of taranabant vs placebo on other lipid or glucose-related endpoints. Incidences of adverse experiences classified in the gastrointestinal (diarrhea and nausea), nervous system (dizziness/dizziness postural), psychiatric-related (irritability and anger/aggression) and vascular (flushing/hot flush) organ systems were higher and statistically significant in the taranabant 2-mg group compared with the placebo group. Irritability was higher and statistically significant in all taranabant groups compared with the placebo group.

CONCLUSION

All three doses of taranabant-induced clinically meaningful and statistically significant weight loss. Incidences of adverse experiences in organ systems known to express CB1R were higher in taranabant groups.

A practical method for quantifying atherosclerotic lesions in rabbits

The rabbit has been widely used for the study of human atherosclerosis; however, the method for analysis of the atherosclerotic lesions has not been standardized between laboratories. The present study reports a practical method for quantifying the changes that occur in aortic atherosclerosis of rabbits. Male Japanese white rabbits were fed with either a standard chow or a diet containing 10% fat and 0.3% cholesterol for 16 weeks. Plasma concentrations of glucose, insulin, total cholesterol, triglycerides and high-density lipoprotein were measured. Aortic atherosclerotic lesions were assessed in quantitative fashion using an image analysis system that measured (1) the gross area of the entire aorta affected by atherosclerosis as defined by Sudan IV staining, (2) the microscopical intimal lesion defined by the elastic van Gieson stain and (3) the infiltration of macrophages and smooth muscle cell proliferation as determined immunohistochemically. The rabbits developed severe aortic atherosclerosis without apparent abnormality of glucose metabolism. The quantitative method described here will be useful for the further investigation of atherosclerosis in rabbits.

Polycomb protein EZH2 regulates E2F1-dependent apoptosis through epigenetically modulating Bim expression

Deregulation of the pRB/E2F pathway, which occurs frequently in human malignancy, is often associated with inappropriate proliferation and/or apoptosis. While the role of E2F1 in apoptosis induction has been well-established, it remains unclear how this pro-apoptotic activity is regulated in cancer. Here we describe EZH2, an oncogenic polycomb histone methyltransferase and an E2F1 target, as an important regulator of E2F1-dependent apoptosis. We show that E2F1 induces EZH2 expression, which in turn antagonizes the induction of E2F1 pro-apoptotic target Bim expression. RNAi-mediated gene depletion of EZH2 enhances E2F1-dependent Bim expression, thereby promoting the pro-apoptotic activity of E2F1. Hence, the concomitant induction of EZH2 and Bim by E2F1 constitutes a fail-safe mechanism to allow tumor cells with aberrant E2F1 activity to evade apoptosis. These findings reveal a novel mechanism by which the apoptotic activity of E2F1 is restrained in human cancer and also provide the first evidence that EZH2 directly regulates apoptotic process in cancer cells.

Safety distance assessment of industrial toxic releases based on frequency and consequence: a case study in Shanghai, China

A case study on the safety distance assessment of a chemical industry park in Shanghai, China, is presented in this paper. Toxic releases were taken into consideration. A safety criterion based on frequency and consequence of major hazard accidents was set up for consequence analysis. The exposure limits for the accidents with the frequency of more than 10(-4), 10(-5)-10(-4) and 10(-6)-10(-5) per year were mortalities of 1% (or SLOT), 50% (SLOD) and 75% (twice of SLOD) respectively. Accidents with the frequency of less than 10(-6) per year were considered incredible and ignored in the consequence analysis. Taking the safety distance of all the hazard installations in a chemical plant into consideration, the results based on the new criterion were almost smaller than those based on LC50 or SLOD. The combination of the consequence and risk based results indicated that the hazard installations in two of the chemical plants may be dangerous to the protection targets and measurements had to be taken to reduce the risk. The case study showed that taking account of the frequency of occurrence in the consequence analysis would give more feasible safety distances for major hazard accidents and the results were more comparable to those calculated by risk assessment.

Treatment with peginterferon plus ribavirin vs. interferon plus ribavirin for 48 weeks in Chinese patients with chronic hepatitis C

INTRODUCTION

Virological responses to interferon (IFN) treatment for chronic hepatitis C (CHC) have been found to be correlated with racial differences. Furthermore, higher sustained virological response (SVR) rates were obtained in many randomised clinical trials (RCT) in Caucasian patients with CHC after treating with peg-IFN than those with IFN. However, it is not clear whether this conclusion can be adapted to patients of Chinese descent.

METHODS

A search of MEDLINE and China National Knowledge Infrastructure between 1966 and 2008 was performed. Trials comparing the use of peg-IFN plus ribavirin vs. IFN plus ribavirin in treating Chinese patients with CHC were assessed.

RESULTS

Of the 94 studies screened, seven RCTs including 398 patients (peg-IFN therapy 232, IFN therapy 166) were analysed. The SVRs obtained in patients treated with peg-IFN plus ribavirin were significantly higher than in patients treated with IFN plus ribavirin [70% vs. 35%, relative risk, 1.76; 95% confidence interval: 1.21-2.56; p (0.01)]. Withdrawal rates were similar between patients treated with peg-IFN plus ribavirin and IFN plus ribavirin.

CONCLUSION

Chinese patients with CHC also have a greater likelihood of achieving an SVR with peg-IFN plus ribavirin.

Effect of biological fouling on passive collectors used to estimate fish recruitment

Evidence is provided that biofouling of artificial substrata for estimating recruitment of nearshore reef fishes influences recruitment, and it is recommended that investigators consider the effects of fouling when estimating recruitment over space and time.

Intracellular oxidative stress and cadmium ions release induce cytotoxicity of unmodified cadmium sulfide quantum dots

OBJECTIVE

To fully understand the cytotoxicity of after-degradation QDs, we synthesized CdS QDs and investigated its toxicity mechanism.

METHODS

Biomimetic method was proposed to synthesize cadmium sulfide (CdS) QDs. Thereafter MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was conducted to evaluate their cytotoxicity. To investigate the toxicity mechanism, we subsequently conducted intracellular reactive oxygen species (ROS) measurement with DCFH-DA, glutathione (GSH) measurement with DTNB, and cellular cadmium assay using atomic absorption spectrometer. Microsized CdS were simultaneously tested as a comparison.

RESULTS

MTT assay results indicated that CdS QDs are more toxic than microsized CdS especially at concentrations below 40 microg/ml. While microsized CdS did not trigger ROS elevation, CdS QDs increase ROS by 20-30% over control levels. However, they both deplete cellular GSH significantly at the medium concentration of 20 microg/ml. In the presence of NAC, cells are partially protected from CdS QDs, but not from microsized particles. Additionally, nearly 20% of cadmium was released from CdS nanoparticles within 24h, which also accounts for QDs' toxicity.

CONCLUSION

Intracellular ROS production, GSH depletion, and cadmium ions (Cd(2+)) release are possible mechanisms for CdS QDs' cytotoxicity. We also suggested that with QD concentration increasing, the principal toxicity mechanism changes from intracellular oxidative stress to Cd(2+) release.

Indoor air pollution from solid biomass fuels combustion in rural agricultural area of Tibet, China

In this study, we are trying to investigate the indoor air pollution and to estimate the residents' pollution exposure reduction of energy altering in rural Tibet. Daily PM(2.5) monitoring was conducted in indoor microenvironments like kitchen, living-room, bedroom, and yard in rural Tibet from December 2006 to March 2007. For kitchen air pollution, impact of two fuel types, methane and solid biomass fuels (SBFs), were compared. Questionnaire survey on the domestic energy pattern and residents' daily activity pattern was performed in Zha-nang County. Daily average PM(2.5) concentrations in kitchen, living-room, bedroom, and yard were 134.91 microg/m(3) (mean, n = 45, 95%CI 84.02, 185.80), 103.61 microg/m(3) (mean, n = 21, 95%CI 85.77, 121.45), 76.13 microg/m(3) (mean, n = 18, 95%CI 57.22, 95.04), and 78.33 microg/m(3) (mean, n = 34, 95%CI 60.00, 96.65) respectively. Using SBFs in kitchen resulted in higher indoor pollution than using methane. PM(2.5) concentrations in kitchen with dung cake, fuel wood and methane use were 117.41 microg/m(3) (mean, n = 18, 95%CI 71.03, 163.79), 271.11 microg/m(3) (mean, n = 12, 95%CI 104.74, 437.48), and 46.96 microg/m(3) (mean, n = 15, 95%CI 28.10, 65.82) respectively. Family income has significant influence on cooking energy choice, while the lack of commercial energy supply affects the energy choice for heating more. The effects of two countermeasures to improve indoor air quality were estimated in this research. One is to replace SBFs by clean energy like methane, the other is to separate the cooking place from other rooms and by applying these countermeasures, residents' exposure to particulate matters would reduce by 25-50% (methane) or 20-30% (separation) compared to the present situation.

PRACTICAL IMPLICATIONS

Indoor air pollution caused by solid biomass fuels is one of the most important burdens of disease in the developing countries, which attracts the attention of environment and public health researchers, as well as policy makers. This paper gives a pilot research on the indoor air pollution and estimated the effects of some intervention policies in Tibet of China, where the living habits of the residents are quite different from other parts of the world. This work would be an important supply to the indoor air pollution studies, and would be helpful in policy making.

The effect of daily administration of IL-18 on cardiac structure and function

Recently, the cytokine Interleukin-18 (IL-18) has been shown to be increased as a result of cardiac surgery. Elevated IL-18 has been associated with neurological dysfunction, systemic inflammatory response syndrome (SIRS), and multiple organ dysfunction syndrome (MODS) post open-heart surgery. The intent of the study contained herein was to determine the effect of IL-18 administration on cardiac function and structure. Eight C57BL/6 female mice were treated daily with 0.5microg/mouse of recombinant IL-18 for 7 days. Long axis echocardiography (ECHO) measurements of the anatomical and hemodynamic function of the heart for all mice were studied 24h after the last dose. The left ventricular wet weights increased from 84 +/- 1 to 93 +/- 3 mg when comparing the placebo (n = 8) with the IL-18 groups, respectively (p = 0.01). With ECHO analysis, IL-18 significantly increased left ventricular (LV) mass, the left atrium dimensions (LA), and the left ventricular posterior wall thickness (LVPW) over the 8-day time period (p < 0.01). There was a 5-fold increase in interstitial cardiac collagen content and a 30% increase in myocyte size in the IL-18 compared with the control groups (p < 0.01). Administration of IL-18 appears to induce interstitial fibrosis and myocyte hypertrophy, resulting in increased ventricular stiffness. Thus, increased IL-18 during and post open-heart surgical procedures may induce left ventricular diastolic dysfunction and affect post-operative outcomes.

[Humoral immune response in mice to hybrid nucleic acid vaccines containing Plasmodium falciparum merozoite surface protein 1 block 17-based gene]

AIM

To analyse the humoral immune response in mice to nucleic acid vaccines (VR1012/HG-MSP1-17 for intracellular expression or VR1012/TPA/HG-MSP-17 for secretion) containing Plasmodium falciparum merozoite surface protein 1 (MSP1) 17 block gene and gene fragment of several T cell epitopes from MSA1, MSA2, RESA, IL-1 and TT.

METHODS

BALB/c or C57BL/6 mice received three times intramuscular immunization with 200 micrograms/100 microliters or 100 micrograms/100 microliters of VR1012/HG-MSP1-17 or VR1012/TPA/HG-MSP1-17 per mouse each time. Anti-HG or anti-MSP1-17 antibodies were monitored by indirect ELISA.

RESULTS

BALB/c and C57BL/6 mice immunized with 100 micrograms/100 microliters of VR1012/HG-MSP1-17 per mouse raised significantly anti-HG and anti-MSP1-17 antibodies, but the levels of antibodies were not high. BALB/c mice immunized with 200 micrograms/100 microliters of VR1012/HG-MSP1-17 per mouse raised higher anti-HG antibodies but not anti-MSP1-17 antibodies. BALB/c mice immunized with 200 micrograms/100 microliters of VR1012/TPA/HG-MSP1-17 per mouse raised low level of anti-HG antibodies only.

CONCLUSION

VR1012/HG-MSP1-17 is more immunogenic than VR1012/TPA/HG-MSP1-17.

Desmoplastic fibroma of the mandible

Desmoplastic fibroma (DF) of the bone, also know as desmoid tumour, is a rare non-metastasizing but locally aggressive tumour. In this case report, we present imaging findings of a histopathologically proven desmoplastic fibroma involving the left mandibular region in a 15-year-old Chinese patient. We have also discussed the usefulness of different imaging modalities (plain film radiography, CT and MRI) in DF diagnosis and treatment.

Degradation rate constants of steroids in sewage treatment works and receiving water

Steroid estrogens are one of the most important groups of endocrine disrupting chemicals (EDCs) which can cause adverse effects on wildlife species and humans. Natural estrogens, including estrone (E1) and estradiol (E2), and synthetic estrogen 17alpha-ethinylestradiol (EE2) together contribute to most of the estrogenic activity in sewage effluents and receiving water. Degradation, particularly aerobic biodegradation was found to be the dominant removal mechanism in these environments. There are a number of factors such as temperature, pH, SRT, HRT and biomass concentration that can affect the rate of biodegradation. This paper reports the results of investigations in to the relationship between the equivalent biomass concentration and degradation rate constants for compounds E1, E2 and EE2 in various environments. It was found that a higher biomass concentration leads to higher rate constants, and relatively good linear correlations (R2 =0.73, 0.79 and 0.73) between the logarithm of the rate constants and the corresponding logarithm equivalent biomass concentration (EBC) values were obtained.