YKL-40: a potential biomarker for osteoarthritis

Current pharmacotherapy for osteoarthritis (OA) alleviates pain and inflammation but does not protect the articular cartilage from further damage or affect disease progression. Biological markers such as YKL-40 may provide a snapshot of current events in joint tissues, allowing rapid assessment of treatments. This review discusses recent data regarding YKL-40, with an emphasis on the relationship between YKL-40 and OA. The presence of YKL-40 in cartilage and synovium in OA patients correlates with histopathological changes and may reflect local disease activity. In addition, the levels of YKL-40 in serum and synovial fluid also seem to correlate with disease severity. The functional role of YKL-40 is not yet clear, but its production as part of the inflammatory response in articular chondrocytes may modulate the cellular response to proinflammatory cytokines, acting to limit connective tissue degradation. Further elucidation of its roles and relationships may enable YKL-40 to act as a useful biomarker in the development of therapies for OA.

Aggrecanase and aggrecan degradation in osteoarthritis: a review

Aggrecanase-mediated aggrecan degradation is a significant event in early-stage osteoarthritis (OA). Aggrecanases belonging to the 'A Disintegrin And Metalloproteinase with ThromboSpondin motifs' (ADAMTS) family of proteinases play a significant role in aggrecan depletion in osteoarthritic cartilage. There has been considerable interest in the possible role of these aggrecanases, especially ADAMTS-4 and ADAMTS-5, as therapeutic targets in OA. This article discusses recent data regarding ADAMTS-4 and ADAMTS-5 in OA, with emphasis on the relationship between aggrecanase and aggrecan degradation as well as the role of aggrecanase in OA.

Fluidization of granular media wetted by liquid 4He

We explore experimentally the fluidization of vertically agitated polymethylmethacrylate spheres wetted by liquid 4He . By controlling the temperature around the lambda point, we change the properties of the wetting liquid from a normal fluid (helium I) to a superfluid (helium II). For wetting by helium I, the critical acceleration for fluidization (Gamma_{c}) shows a steep increase close to the saturation of the vapor pressure in the sample cell. For helium II wetting, Gamma_{c} starts to increase at about 75% saturation, indicating that capillary bridges are enhanced by the superflow of the unsaturated helium film. Above saturation, Gamma_{c} enters a plateau regime where the capillary force between particles is independent of the bridge volume. The plateau value is found to vary with temperature and shows a peak at 2.1K , which we attribute to the influence of the specific heat of liquid helium.

The development and genetic diversity of H5N1 influenza virus in China, 1996-2006

Since it was first detected in 1996, the Goose/Guangdong/1/1996 (Gs/GD) H5N1 influenza virus and its reassortants have spread to over 60 countries, with over 20 distinct genetic reassortants previously recognized. However, systematic analysis of their interrelationship and the development of genetic diversity have not been explored. As each of those reassortants was first detected in China, here 318 full-length H5N1 virus genomes isolated from 1996 to 2006 in this region were phylogenetically analyzed. Our findings revealed two major group reassortment events in 2001 and 2002 that were responsible for the generation of the majority of the 44 distinct Gs/GD genotypes identified, excepting those 1997 variants. Genotype replacement and emergence occurred continually, with 34 transient genotypes detected while only 10 variants were persistent. Two major replacements of predominant genotypes were also observed: genotype B replaced by Z in 2002 and then genotype Z replaced by the now predominant genotype V in 2005.

Dynamics of alpha helix formation in the CSAW model

We study the folding dynamics of polyalanine (Ala20), a protein fragment with 20 residues whose native state is a single alpha helix. We use the CSAW model (conditioned self-avoiding walk), which treats the protein molecule as a chain in Brownian motion, with interactions that include hydrophobic force and internal hydrogen bonding. We find that large-scale structures form before small-scale structures, and obtain the relevant relaxation times. We find that helix nucleation occurs at two separate points on the protein chain, one near each end. The evolution of small- and large-scale structures involves different mechanisms. While the former can be described by rate equations that govern the growth of helical content, the latter is akin to the relaxation of an elastic solid.

The relationship between overexpression of glial cell-derived neurotrophic factor and its RET receptor with progression and prognosis of human pancreatic cancer

We used immunohistochemical staining to assess protein over-expression of glial cell-derived neurotrophic factor (GDNF) and its RET receptor tyrosine kinase in patients with pancreatic cancer and benign pancreatic neoplasm, and assessed correlations with clinicopathological features and prognosis. Surgically resected pancreatic cancer patients (40/58, 68.9%) showed positive GDNF immunostaining, a significantly higher frequency than in patients with benign pancreatic tumour (3/11, 27.3%). Intrapancreatic neural invasion by cancer cells was significantly related to over-expression of GDNF. Strongly positive expression of GDNF was significantly more frequent than lesser grades of expression in patients with severe back pain before and 12 months after surgery. Expression of RET was significantly related to lymphatic invasion, survival rate after tumour resection and degree of tumour cell differentiation. We conclude that GDNF may be important in pancreatic cancer proliferation and metastasis, especially in patients with perineural invasion. Strongly positive expression of GDNF may be an indication for early intensified radiotherapy. RET expression in pancreatic cancer tissues may be a useful prognostic marker.

Chinese response to allergy and asthma in Olympic athletes

China is going to host the Games of the XXIX Olympiad from 8-24 August 2008 in Beijing. The number of athletes and accompanying individuals expected to arrive at China for the Beijing Olympics is estimated at over 10 000 and among them at least 2 000 (20%) are suspected to suffer from respiratory allergies. It is important to monitor the pollen counts and improve air quality in Beijing because Olympic athletes would be exposed to airborne allergens and pollutants during competitions which could hinder peak performance. The main pollen and spore families in Beijing are Artemisia, Ambrosia, Chenopodiaceae and Gramineae. They can reach around 307 000 grains of pollen/1000 m(3) of air in August. Economic development in China is usually linked with worsening of air quality. Due to the adoption of various control measures, the ambient air quality in a number of areas in Beijing has actually improved. The ambient air TSP and SO(2) levels in Beijing have been decreasing in the last decade. However, ambient air NO(x) level has been increasing due to the increased number of motor vehicles. Nevertheless, dedicated medical facilities in Beijing will provide medical services to athletes and delegations from all over the world during the Beijing Olympic Games.

No association found between the promoter variants of TNF-alpha and diabetic retinopathy in Chinese patients with type 2 diabetes

PURPOSE

Necrosis tumor factor (TNF) is known to be associated with diabetic retinopathy (DR). The objective of this study was to examine the genetic variations of TNF-alpha and assess their possible relationship to DR in type 2 diabetic patients in the Chinese population.

MATERIALS AND METHODS

We conducted a case-control association study between the promoter variants of TNF-alpha and diabetic retinopathy in Chinese patients with type 2 diabetes. We selected three variants in the promoter region of TNF-alpha, namely rs1800629, rs1041981, and rs2857713.

RESULTS

No individual SNP nor any haplotype was found to be associated with DR in our study.

CONCLUSION

This is the first study to report TNF-alpha polymorphisms in patients with DR in the Chinese population. The results suggest that the variants among the promoter of TNF-alpha are unlikely to play a major role in the susceptibility to DR in Chinese patients with type 2 diabetes.

Global patterns of gene expression in rice cultivars undergoing a susceptible or resistant interaction with the parasitic plant Striga hermonthica

Striga hermonthica is a root hemiparasite of cereals that causes devastating loss of yield. Recently, a rice cultivar, Nipponbare, was discovered, which exhibits post-attachment resistance to this parasite and quantitative trait loci (QTL) associated with the resistance were identified. Changes in gene expression in susceptible (IAC 165) and resistant (Nipponbare) rice cultivars were profiled using rice whole-genome microarrays. In addition to a functional categorization of changes in gene expression, genes that were significantly up-regulated within resistance QTL were identified. The resistance reaction was characterized by up-regulation of defence genes, including pathogenesis-related proteins, pleiotropic drug resistance ABC transporters, genes involved in phenylpropanoid metabolism and WRKY transcription factors. These changes in gene expression resemble those associated with resistance to microbial pathogens. Three genes encoding proteins of unknown function, within a major resistance QTL on chromosome 12, were highly up-regulated and are excellent candidate resistance genes. The susceptible interaction was characterized by large-scale down-regulation of gene expression, particularly within the functional categories plant growth regulator signalling and metabolism, biogenesis of cellular components and cell division. Up-regulated genes included nutrient transporters, enzymes of amino acid metabolism and some abiotic stress genes.

Quantification of brain creatine concentration using PRESS sequence and LCModel: comparison with HPLC method

To investigate the accuracy for quantification of brain total creatine (Cr) concentration using in vivo long echo time (TE) PRESS sequence with an external standard and LCModel. Ten swine and an external standard containing a detectable compounds of known concentration were studied by using 1.5 T GE Signa scanner and the standard head coil; the single-voxel proton magnetic resonance spectroscopy (1H-MRS) data was acquired from the 20-mm cubic VOI which was placed in the swine brain and external standard respectively by using the PRESS sequence with TE=135 msec, TR=1500 msec, and 128 scan averages. The quantification of Cr was accomplished by the linear combination of model spectra (LCModel). After MRS examination, each animal was sacrificed, and in vitro Cr concentration was analyzed by high performance liquid chromatography (HPLC). In the MRS group, the mean concentration of Cr was 9.37+/-0.137mmol/kg; in the HPLC group, the mean concentration of Cr was 8.905+/-0.126 mmol/kg. There were no statistically significant differences between two methods (P=0.491), which indicated that long TE PRESS sequence with an external standard can accurately detect the brain Cr concentration. The application of LCModel introduces more convenience for the MRS quantification.

Comparison of nutritional quality between Chinese indica rice with sck and cry1Ac genes and its nontransgenic counterpart

Nutritional assessment of transgenic crops used for human food and animal feed is an important aspect of safety evaluations. An insect-resistant rice (IRR) was generated by the stable insertion of sck, a modified cowpea trypsin inhibitor gene, and cry1Ac, encoding a crystal protein from Bacillus thuringiensis into the genome of a common variety of Chinese indica rice. The composition of the brown and milled rice grain from the resulted IRR line designated Liangyou Kefeng No. 6 was compared with that of the parental rice cultivar Liangyou 2186. Nutrients, including the proximates, amino acids, fatty acids, minerals, and vitamins, were measured. The antinutritive components such as phytic acid, lectin, and trypsin inhibitors were also examined. The data demonstrated that the nutritional quality of both the brown and milled rice grains from the transgenic line was substantially equivalent to that of the nontransgenic counterpart, and measured amounts of nutritional components fell within the range of values reported for other commercial lines.

Lifelong farm exposure may strongly reduce the risk of asthma in adults

BACKGROUND

Farm exposures may protect against childhood asthma, hay fever and eczema. Whether farm exposures also confer protection in adult farmers remains unclear. Moreover, little is known about the role of timing of exposure. We assessed the effects of current and childhood farm exposures on asthma, hay fever and eczema in farmers and a rural nonfarming control population.

METHODS

We conducted a cross-sectional questionnaire survey in 2509 farming families (response rate 78%) and 1001 nonfarming families (response rate 67%), which included 4288 farmers and 1328 nonfarmers.

RESULTS

Farmers were less likely to have asthma symptoms, hay fever and eczema; no significant differences were observed among dairy, sheep and beef, and horticulture farmers. A combination of current and childhood exposure was more strongly associated with shortness of breath (OR 0.50, CL 0.39-0.66), wheeze (OR 0.60, CL 0.49-0.73), asthma medication (OR 0.48, CL 0.37-0.63); and asthma ever (OR 0.56, CL 0.46-0.68) than current exposure alone (OR 0.63, CL 0.47-0.84; OR 0.80, CL 0.65-0.99; OR 0.68, CL 0.51-0.9; OR 0.69, CL 0.56-0.85 respectively) or childhood exposure alone (OR 0.97, CL0.65-1.44; OR 1.01, CL 0.75-1.34; OR 0.78, CL 0.51-1.19; OR 0.87, CL 0.63-1.19 respectively). Moreover, the combined number of years of farm exposure in childhood and adulthood showed a dose-dependent inverse association with symptom prevalence.

CONCLUSIONS

Although both current and childhood farm exposures may play a role in the observed low prevalence of asthma symptoms in adult farmers, continued long-term exposure may be required to maintain optimal protection.