Preparation and characterization of polysulfone ultrafiltration membranes for concentrating waste tuna broth

Three sets of ultrafiltration (UF) membranes were prepared containing the following proportions (w/w) of polysulfone and dimethylacetamide: 14.5/85.5, 15.0/85.0 and 15.5/84.5. The membranes were characterized in terms of water flux, molecular weight (MW) cut-off, fouling, average pore size and ratio of pore surface area to membrane area. Membrane water flux was found to decrease as the polysulfone concentration or membrane thickness was increased. Scanning electron microscopy showed an asymmetric pore structure and indicated that the variation in water flux between membrane sets were probably due to differences in the number of pores per unit membrane area and not to differences in pore diameter. The MW cut-off for all the membranes was found to be close to 66 kD. The permeate flux for standard proteins decreased with increasing protein MW. A decrease in water flux was also observed after the UF runs; this could be explained by membrane fouling.

Defatted waste tuna broth, which was obtained from a fish canning plant as steam condensate after autoclaving fresh tuna, was ultrafiltered using the prepared membranes. The rejection coefficient for either protein or carbohydrate solute of the tuna broth was approximately 54.5% while solute recovery was about 90%. The ultrafiltered broth had negligible turbidity and odor.     

Prognostic and Predictive Roles of KRAS Mutation in Colorectal Cancer

The RAS gene family is among the most studied and best characterized of the known cancer-related genes. Of the three human ras isoforms, KRAS is the most frequently altered gene, with mutations occurring in 17%–25% of all cancers. In particular, approximately 30%–40% of colon cancers harbor a KRAS mutation. KRAS mutations in colon cancers have been associated with poorer survival and increased tumor aggressiveness. Additionally, KRAS mutations in colorectal cancer lead to resistance to select treatment strategies. In this review we examine the history of KRAS, its prognostic value in patients with colorectal cancer, and evidence supporting its predictive value in determining appropriate therapies for patients with colorectal cancer.