Organic films on an impervious surface (window glass) were sampled at paired indoor-outdoor sites in July 2000 and characterized for their paraffinic and polar organic compositions along an urban-rural transect. Four classes of polar compounds (C11-C31 aliphatic monocarboxylic, C6-C14 dicarboxylic, nine aromatic polycarboxylic, and five terpenoid acids) constituted between 81 and 95% (w/w) of the total organic fraction analyzed comprising n-alkanes (C10-C36), 46 PAH, 97 PCBs, and 18 OC pesticides. Concentrations of the polar compounds plus their precursors, n-alkanes, ranged from 8 to 124 microg m(-20 and were dominated by monocarboxylic acids (67-89%, w/w). On outdoor windows, n-alkanes, aromatic acids, and terpenoid acids decreased in concentration along the urban-rural transect. The carbon preference index values and the interpretations of individual compounds indicate that the main sources of n-alkanes were plant waxes followed by petrogenic sources; monocarboxylic and dicarboxylic acids were from plant waxes and animal fats. Results of principal component analysis showed closer correspondence between outdoor and indoor signatures than among locations. In outdoor films, these compounds are suggested to play an important role in mediating chemical fate in urban areas by air-film exchange and facilitating "wash-off" due to their surfactant-like properties. In indoor films, these compounds provide a medium for the accumulation of more toxic compounds.

Gastrointestinal lymphoma is the most common form of lymphoma in the cat. More recently, an ultrasonographic pattern associated with feline small cell T-cell gastrointestinal lymphoma has been recognized as a diffuse thickening of the muscularis propria of the small intestine. This pattern is also described with feline inflammatory bowel disease. To evaluate the similarities between the diseases, we quantified the thickness of the muscularis propria layer in the duodenum, jejunum and ileum of 14 cats affected by small cell T-cell lymphoma and inflammatory bowel disease (IBD) and 19 healthy cats. We found a significantly increased thickness of the muscularis propria in cats with lymphoma and IBD compared with healthy cats. The mean thickness of the muscularis propria in cats with lymphoma or IBD was twice the thickness than that of healthy cats, and was the major contributor to significant overall bowel wall thickening in the duodenum and jejunum. A muscularis to submucosa ratio >1 is indicative of an abnormal bowel segment. Colic lymph nodes in cats with lymphoma were increased in size compared with healthy cats. In cats with gastrointestinal lymphoma and histologic transmural infiltration of the small intestines, colic or jejunal lymph nodes were rounded, increased in size and hypoechoic.

An Escherichia coli strain, JM109, was successfully engineered into an efficient hyaluronic acid (HA) producer by co-expressing the only known class-II HA synthase from a Gram-negative bacterium (Pasteurella multocida) and uridine diphosphate-glucose dehydrogenase from E. coli K5 strain. The engineered strain produced about 0.5 g/L HA in shake flask culture and about 2.0-3.8 g/L in a fed-batch fermentation process in a 1-L bioreactor. The sharp increase in viscosity associated with HA accumulation necessitated pure oxygen supplement to maintain fermentation in aerobic regime. Precursor supply during HA synthesis was probed by glucosamine supplement, which shortens biosynthesis pathway and eliminates one step requiring ATP. HA synthesis was increased with glucosamine supplement from 2.7 to 3.7 g/L (37%), which was mirrored with a concomitant 42% decrease in pure oxygen input, suggesting a close connection between energy metabolism and precursor supply. Decoupling HA synthesis from cell growth by using fosfomycin (an inhibitor for cell wall synthesis) led to a 70% increase in HA synthesis, suggesting detrimental effects on HA synthesis from cell growth via precursor competition. This study demonstrates a potentially viable process for HA based on a recombinant E. coli strain. In addition, the precursor supply limitation identified in this study suggests new engineering targets in subsequent metabolic engineering efforts.

Escherichia coli is the most commonly used host for recombinant protein production and metabolic engineering. Extracellular production of enzymes and proteins is advantageous as it could greatly reduce the complexity of a bioprocess and improve product quality. Extracellular production of proteins is necessary for metabolic engineering applications in which substrates are polymers such as lignocelluloses or xenobiotics since adequate uptake of these substrates is often an issue. The dogma that E. coli secretes no protein has been challenged by the recognition of both its natural ability to secrete protein in common laboratory strains and increased ability to secrete proteins in engineered cells. The very existence of this review dedicated to extracellular production is a testimony for outstanding achievements made collectively by the community in this regard. Four strategies have emerged to engineer E. coli cells to secrete recombinant proteins. In some cases, impressive secretion levels, several grams per liter, were reached. This secretion level is on par with other eukaryotic expression systems. Amid the optimism, it is important to recognize that significant challenges remain, especially when considering the success cannot be predicted a priori and involves much trials and errors. This review provides an overview of recent developments in engineering E. coli for extracellular production of recombinant proteins and an analysis of pros and cons of each strategy.

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Neuronal excitability is an important determinant of both synaptic plasticity and learning in aged subjects.

Glucosamine (GlcN), an amino sugar, is a compound derived from substitution of a hydroxyl group of a glucose molecule with an amino group. GlcN and its acetylated derivative, N-acetylglucosamine (GlcNAc), have been widely used in food, cosmetics, and pharmaceutical industries and are currently produced by acid hydrolysis of chitin (a linear polymer of GlcNAc) extracted from crab and shrimp shells. Microbial fermentation by filamentous fungi or recombinant Escherichia coli, as an alternative method for the production of GlcN and GlcNAc, is attracting increasing attention because it is an environmentally friendly process. Although the microbial production of GlcN and GlcNAc is hampered by low yield and high production cost, considerable advances have been made in recent years. Here we review the applications, commercial market, and production of GlcN and GlcNAc, with emphasis on the metabolic and process engineering strategies used to improve GlcN and GlcNAc production by recombinant microbes.

Background Growing Up Milk (GUM) was developed to assist young children in meeting their nutritional requirements during the second year of life. However, there is limited evidence that GUM improves nutritional status and growth in young children. Objectives To evaluate the effect of consuming Growing Up Milk “Lite” (GUMLi) (reduced protein with synbiotics and micronutrients added) compared with standard cow milk as part of a whole diet for 1 y on body composition at 2 y of age. Methods GUMLi Trial was a multicenter, double-blind, randomized placebo-controlled trial conducted in Auckland and Brisbane. Healthy 1-y-olds were recruited and randomly assigned to receive either GUMLi or standard cow milk for 12 mo as part of a whole diet. The primary outcome was percentage body fat at 2 y of age measured by bioelectrical impedance. All regression models adjusted for baseline outcome and study center. Results 160 children (80 per arm) were randomly assigned, and 134 (67 per arm) were included in the modified intention-to-treat analyses. The mean percentage body fat at 12 mo was 23.3% (SD 7.9) in the GUMLi group and 25.7% (SD 7.2) in the cow milk group. After adjusting for baseline outcome and study location, the estimated mean difference in percentage body fat between the intervention and control at 12 mo was −2.19% (95% CI: −4.24, −0.15; P = 0.036). Per-protocol analysis showed a similar effect (mean difference: −2.09%; 95% CI: −4.16, −0.03; P = 0.047). Both fat mass and the fat mass index were significantly lower in the GUMLi group at 12 mo than in the cow milk group. Conclusions At 2 y of age, children who consumed a GUM with a lower protein content than cow milk over 12 mo had a lower percentage of body fat. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12614000918628.