Multiple logistic regression analysis of risk factors for carcinogenesis of oral submucous fibrosis in mainland China

Oral submucous fibrosis (OSF), a chronic progressive disorder, is regarded as the premalignant lesion of oral squamous cell carcinoma (OSCC). Its distribution is associated with chewing betel quid (BQ). The objective of the present study was to investigate risk factors for the carcinogenesis of OSF in mainland China. A case-control study was performed in 42 patients with OSCC that originated from OSF and 40 OSF controls. Epidemiological data and information related to risk factors were collected using a short structured questionnaire. Odd ratios (OR) and 95% confidence intervals (CI) were derived from logistic regression analysis. In multivariate analysis, only age, duration of BQ chewing, duration of cigarette smoking, and OSF accompanied by oral leukoplakia or oral lichen planus were associated with significantly increased risk for the malignant transformation of OSF. These findings contribute to current knowledge on the prevention of carcinogenesis of OSF in mainland China.

Identification of a novel switch in the dominant forms of cell adhesion-mediated drug resistance in glioblastoma cells

The failure of malignant cells to undergo apoptosis is a major obstacle in cancer therapy, and thus identifying the underlining molecules involved therein is imperative for improving patient survival. An important mechanism of drug resistance is cell adhesion-mediated drug resistance (CAM-DR). In this study we identify a novel switch by which glioblastoma multiforme (GBM) cells alter the mode of CAM-DR. In the absence of a microenvironmental cue provided by components of the extracellular matrix (ECM), GBM cells are able to employ an alternative, but equally effective, mode of CAM-DR by forming spheres via cell-cell interactions. Intriguingly, when inhibiting cell-cell interactions in the absence of ECM components, either by low cell density or by inhibition of gap junctions (intercellular connexin tunnels) through chemical inhibition with carbenoxyolone or co-incubation with the connexin-mimicking Gap 27 Cx37,43 peptide, GBM cells were sensitized to tumor necrosis factor-related apoptosis-inducing ligand- and CD95-induced apoptosis. By demonstrating that GBM cells can alternate from one form of CAM-DR (cell-substrate tethering) to another (homocellular cell-cell adhesion) and that inhibition of both forms is necessary for apoptosis sensitization, our findings not only have important implications for novel approaches to restore defective apoptosis programs, but also reveal a novel role of gap junctions in GBM.

Intact Adelta-fibers up-regulate transient receptor potential A1 and contribute to cold hypersensitivity in neuropathic rats

Mechanisms underlying cold hypersensitivity in neuropathic states are unclear. Recent data indicate both transient receptor potential (TRP) M8 and TRPA1 play a role. In relation to TRPA1, there are reported increases in mRNA. However, it is unknown whether TRPA1 mRNA is translated into functional receptors, whether these receptors are found on peripheral nociceptors and what population of primary afferents expresses the receptors. The present study provides several lines of evidence that TRPA1 receptors are expressed on intact primary sensory neurons and contribute to cold hypersensitivity following spinal nerve ligation (SNL). Immunohistochemical studies show that expression of TRPA1 is significantly increased in the ipsilateral compared with the contralateral L4 dorsal root ganglion (DRG). Using mustard oil (MO, selective TRPA1 agonist), Ca(2+) imaging demonstrates an increase in the percentage of MO-sensitive L4 DRG cells in SNL compared with sham and naive rats. The magnitude of the Ca(2+) response evoked by MO is also significantly larger in SNL compared with sham and naive rats. Behavioral studies demonstrate that SNL results in increased nocifensive behaviors to mechanical and cold stimulation that is not seen in sham or naive rats. Behavioral responses in sham rats are no different from naive rats. In vitro single fiber recordings demonstrate Adelta-fibers (intact L4 axons) in the nerve-injured hind paw have conduction velocities no different from naive rats. In contrast, compared with naive rats, mechanical thresholds of the Adelta-fibers in SNL rats are significantly decreased, the proportion of cold-sensitive and MO-sensitive Adelta-fibers is significantly increased and the response magnitude of Adelta-fibers to MO is significantly increased. MO-induced activity in Adelta-fibers is significantly reduced by Ruthenium Red (TRPA1 receptor antagonist). These results demonstrate that TRPA1 is expressed on peripheral nociceptors, and they are up-regulated on intact Adelta-fibers following nerve injury, contributing to cold hypersensitivity.

Group II metabotropic glutamate receptor activation attenuates peripheral sensitization in inflammatory states

Several lines of evidence indicate that Group II metabotropic glutamate receptor (mGluR) activation can depress sensory transmission. We have reported the expression of Group II mGluRs on unmyelinated axons, many of which were presumed to be nociceptors, in the rat digital nerve [Carlton SM, Hargett GL, Coggeshall RE (2001b) Localization of metabotropic glutamate receptors 2/3 on primary afferent axons in the rat. Neuroscience 105:957-969]. The goals of the present study are to further our understanding of Group II modulation of nociceptor processing in the periphery, documenting behavioral changes using inflammatory models and documenting, for the first time, cutaneous single fiber activity following exposure to a Group II agonist (2R,4R)-4-aminopyrrolidine-2,4-dicarboxylate (APDC) and antagonist (2S)-2-amino-2-[(1S,2S)-2-carboxycycloprop-1-yl]-3-(xanth-9-yl) propanoic acid (LY341495, LY). The data indicate that peripheral Group II mGluR activation does not depress nociceptive behaviors or nociceptor fiber responses in the non-sensitized state (i.e. following brief nociceptive mechanical or thermal stimulation) but can depress these responses when nociceptors are sensitized by exposure to formalin or inflammatory soup. Group II mGluR agonist-induced inhibition can be blocked by a selective Group II antagonist. Peripheral Group II mGluR-induced inhibition evoked in these studies occurs through activation of local receptors and not through spinal or supraspinal mechanisms. The data indicate that administration of selective Group II agonists may be potent therapeutic agents for prevention of peripheral sensitization and for treatment of inflammatory pain.

Development of a SYBR Green I real-time PCR for quantitative detection of Vibrio alginolyticus in seawater and seafood

AIM

Vibrio alginolyticus is an economically important micro-organism. The main aim of the present study was to develop a real-time polymerase chain reaction (PCR) assay for rapid, sensitive and effective quantification of V. alginolyticus in seawater and seafood.

METHODS AND RESULTS

Purified DNA of V. alginolyticus, artificially inoculated seawater and seafood tissue homogenates were subjected to the gyrB-targeted real-time PCR assay. Natural seawater and seafood samples were analysed by this real-time PCR protocol. Specificity tests showed that positive result was obtained only with V. alginolyticus strains. The detection sensitivity was determined to be 0.4 pg of genomic DNA equivalent to 72 cells per PCR in pure culture and 100 cells in 1 ml of seawater or seafood tissue homogenates. Single cell detection is achieved after 3 h of sample enrichment.

CONCLUSIONS

A sensitive and specific SYBR Green I-based real-time PCR assay targeting gyrB gene was successfully developed to quantify V. alginolyticus within 6 h in seawater and seafood samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

No report on the molecular-based method was available for quantitative detection of V. alginolyticus. This work will provide a novel method for evaluation of the risk of V. alginolyticus to marine environmental health and seafood safety.

Effect of temperature on pharmacokinetics of enrofloxacin in mud crab, Scylla serrata (Forsskål), following oral administration

The study was conducted to evaluate the pharmacokinetics of enrofloxacin following a single oral gavage (10 mg kg(-1)) in mud crab, Scylla serrata, at water temperatures of 19 and 26 degrees C. Enrofloxacin concentration in haemolymph was determined using high-performance liquid chromatography (HPLC). A multiple and repeated haemolymph sampling from the articular cavity of crab periopods was developed. The haemolymph of an individual crab was successfully sampled up to 11 times from the articular cavity. The profile of haemolymph enrofloxacin concentration of an individual crab versus time was thus achieved. The mean haemolymph enrofloxacin concentration versus time was described by a two-compartment model with first-order absorption at two water temperatures. The peak concentrations of haemolymph enrofloxacin at 19 and 26 degrees C were 7.26 and 11.03 mug mL(-1), at 6 and 2 h, respectively. The absorption and distribution half-life time ( and t(1/2alpha)) at 19 degrees C were 3.7 and 4.5 h, respectively, which were markedly larger than the corresponding values (1.1 and 1.5 h) at 26 degrees C; the elimination half-life time (t(1/2beta)) was 79.1 and 56.5 h at 19 and 26 degrees C, respectively. The area under curve (AUC), total body clearance (Cl) and mean residence time (MRT(0-infinity)) at 19 degrees C were 636.0 mg L(-1) h, 0.016 L h(-1) kg(-1) and 102.5 h, respectively; the corresponding values at 26 degrees C were 583.4 mg L(-1) h, 0.018 L h(-1) kg(-1)and 63.7 h. These results indicate that enrofloxacin is absorbed and eliminated more rapidly in mud crab at 26 degrees C than at 19 degrees C.

Rapid and sensitive detection of Singapore grouper iridovirus by loop-mediated isothermal amplification

AIMS

The aim of this paper was to develop a loop-mediated isothermal amplification (LAMP) method for rapid, sensitive and inexpensive detection of Singapore grouper iridovirus (SGIV) in grouper (GP), Epinephelus sp.

METHODS AND RESULTS

A set of six specific primers was designed by targeting the SGIV ORF-014L. With Bst DNA polymerase large fragment, the target DNA can be amplified as early as 20 min at 65 degrees C in a simple water bath. The detection limit is about 0.02 fg (equivalent to 6.3 copies) of plasmid ORF-014L. LAMP products could be judged with three different methods. There were no cross-reactions with seven other aquatic animal viruses indicating high specificity of the LAMP. The LAMP method was applied to detect SGIV in virus-infected GP cells and GP tissues effectively.

CONCLUSIONS

The LAMP described in this study is a cheap, sensitive, specific and rapid protocol for the detection of SGIV in cells and in GP tissues.

SIGNIFICANCE AND IMPACT OF THE STUDY

The developed LAMP method can be simply applied both in field condition and in laboratory operation for specific detection of SGIV infection.

Molecular and cellular events in alcohol-induced muscle disease

Alcohol consumption induces a dose-dependent noxious effect on skeletal muscle, leading to progressive functional and structural damage of myocytes, with concomitant reductions in lean body mass. Nearly half of high-dose chronic alcohol consumers develop alcoholic skeletal myopathy. The pathogenic mechanisms that lie between alcohol intake and loss of muscle tissue involve multiple pathways, making the elucidation of the disease somewhat difficult. This review discusses the recent advances in basic and clinical research on the molecular and cellular events involved in the development of alcohol-induced muscle disease. The main areas of recent research interest on this field are as follows: (i) molecular mechanisms in alcohol exposed muscle in the rat model; (ii) gene expression changes in alcohol exposed muscle; (iii) the role of trace elements and oxidative stress in alcoholic myopathy; and (iv) the role of apoptosis and preapoptotic pathways in alcoholic myopathy. These aforementioned areas are crucial in understanding the pathogenesis of this disease. For example, there is overwhelming evidence that both chronic alcohol ingestion and acute alcohol intoxication impair the rate of protein synthesis of myofibrillar proteins, in particular, under both postabsorptive and postprandial conditions. Perturbations in gene expression are contributory factors to the development of alcoholic myopathy, as ethanol-induced alterations are detected in over 400 genes and the protein profile (i.e., the proteome) of muscle is also affected. There is supportive evidence that oxidative damage is involved in the pathogenesis of alcoholic myopathy. Increased lipid peroxidation is related to muscle fibre atrophy, and reduced serum levels of some antioxidants may be related to loss of muscle mass and muscle strength. Finally, ethanol induces skeletal muscle apoptosis and increases both pro- and antiapoptotic regulatory mechanisms.

An integrated assessment model of carbon sequestration benefits: a case study of Liping county, China

This research attempts to model the complexity of planting trees to increase China's CO(2) sequestration potential by using a GIS-based integrated assessment (IA) approach. We use the IA model to assess the impact of China's Grain for Green reforestation and afforestation program on farmer and state incomes as well as CO(2) sequestration in Liping County, Guizhou Province. The IA model consists of five sub-models for carbon sequestration, crop income, timber income, Grain for Green, and carbon credits. It also includes a complementary qualitative module for assessing program impacts by gender and ethnicity. Using four scenarios with various assumptions about types of trees planted, crop incomes by township, CO(2) credit prices, state subsidies, methods for estimating carbon sequestered, and harvesting of trees, we find great variation in the impact of the Grain for Green program on incomes and on carbon sequestered over a 48 year period at both the county and township levels.