Osteopontin, CCL5 and CXCL9 are independently associated with psoriasis, regardless of the presence of obesity.

Psoriasis is an autoimmune disease associated with the production of pro-inflammatory cytokines. The identification of these molecules in the pathogenesis of psoriasis facilitated the use of monoclonal antibodies to block their actions as a treatment for severe psoriasis. An increased inflammatory response has been documented in patients with obesity, a condition that is associated with the occurrence and severity of psoriasis. Osteopontin (OPN), TNF and CXCL9 levels are enhanced in patients with psoriasis, although OPN has been documented in the adipose tissue of obese patients without psoriasis. The prevalence of obesity is much higher in psoriasis patients compared with the general population. Thus, we aimed to evaluate the relationship between cytokine levels and psoriasis in the context of obesity. We compared OPN and CXCL9 plasma levels among 117 psoriasis patients and 27 healthy body mass index-matched subjects using ELISA. We also analyzed the TNF, CCL2 and CCL5 levels in a smaller subgroup of patients and matched controls. Median OPN, CCL5 and CXCL9 levels were significantly higher in psoriasis patients compared with the controls, independent of obesity. There was no difference between the median CCL2 levels in the psoriasis patients and the controls (P<0.05), although the CCL2 levels were elevated in obese patients compared with non-obese psoriasis patients (P<0.001). Facial involvement and the psoriasis area severity index (PASI) score were not associated (P<0.05) with OPN levels or elevated levels of chemokines. There was no significant correlation between the OPN and CXCL9 levels or the OPN and TNF levels in psoriasis patients. This work confirms that OPN, CCL5 and CXCL9 plasma levels are higher in psoriasis patients and provides evidence that their higher levels are not a consequence of obesity. Furthermore, the results demonstrate that OPN production is independent of TNF-α and CXCL9.

Polymer induced flocculation and separation of particulates from extracts of lignocellulosic materials.

Biofuels from lignocellulosic materials like wood are renewable and sustainable alternatives to petroleum and other fossil fuels. Wood can be grown and harvested without adding to the carbon load of the atmosphere and thus can be part of the solution to the problem posed by global climate changes. Recently much interest has developed on the concept of the forest product biorefinery, where wood is hydrolyzed prior to conventional pulping and papermaking processes and the hydrolyzate consisting of hemicellulose sugars are to be used as a feedstock for biofuels or bioplastics. The purification of the hydrolyzate stream and the separation of fermentable sugars from it thus constitutes an important step in biorefinery processes. The separation of particulate material from wood hydrolyzates is considered in this paper. Sugar maple hardwood was extracted with hot water at 160 degrees C. The extracts contain hemicelluloses (primarily xylooligomers, xylose and xylan), acetic acid and smaller amounts of lignin. The colloidal stability of the extracts plays a critical role in the separation and purification of the wood extracts. Here, we report the size and charge of the particles in the extract measured using standard instruments based on light scattering and microelectrophoresis. Particles were found to be in the size range from approximately 220nm to 270nm. Zeta potential measurements showed them to be negatively charged. By treating the extracts with a cationic flocculating agent poly-DADMAC, it was possible to preferentially precipitate out the colloidal fraction containing lignin and lignin derived compounds. Upon the addition of poly-DADMAC the turbidity of the suspension reduced from 920 NTU to 4 NTU in a 24 h period and particulates sedimented from the extract. The lignin concentration was reduced in the supernatant, while the sugar content remained unchanged. The addition of an indifferent electrolyte hindered the effectiveness of the polyelectrolyte. The optimum pH for the effectiveness of the polymer was found to be around 4.5. In order to accelerate the sedimentation of the particles, Kaolin was added to attach to the flocs after adding the polyelectrolyte. Kaolin helped accelerate the separation of the particulates by almost an order of magnitude. This work shows that flocculation with a cationic polyelectrolyte followed by separation by sedimentation, centrifugation or microfiltration can be an effective technique to purify biorefinery wood extracts.