Population of lungs by mast cells.

Mast cells are tissue-resident cells that are localized particularly in the skin, gastrointestinal tract and respiratory tract. They are mainly recognised for their role in adaptive immunity and allergy where cross-linking of surface-bound IgE results in acute mediator release giving early symptoms, and cytokine production contributing to chronic changes. The mast cell is now also increasingly recognized for its role in innate immunity conferred by its repertoire of complement and Toll receptors. Thus, mast cell deletion has been shown to suppress certain innate immune responses in murine models. Our interest is in the mechanisms involved in population of tissues by mast cells, particularly the airways. Mast cells are released from the bone marrow into the blood as committed precursors. These cells circulate in very low numbers and accumulate in tissues where they proliferate and mature under the influence of local cytokines and growth factors that define the mature phenotype appropriate for their location. Chemoattraction is important at critical phases in the life history of the mast cell, i.e. movement towards and through the bone marrow sinus endothelium, recruitment to tissues and movement within the tissues to the location of the mature cell. These phases are dependent on chemoattractants generated at specific locations acting on cell surface receptors whose repertoire evolves as the mast cell matures.

Selective suppression of leukocyte recruitment in allergic inflammation.

Allergic diseases result in a considerable socioeconomic burden. The incidence of allergic diseases, notably allergic asthma, has risen to high levels for reasons that are not entirely understood. With an increasing knowledge of underlying mechanisms, there is now more potential to target the inflammatory process rather than the overt symptoms. This focuses attention on the role of leukocytes especially Th2 lymphocytes that regulate allergic inflammation and effector cells where eosinophils have received much attention. Eosinophils are thought to be important based on the high numbers that are recruited to sites of allergic inflammation and the potential of these cells to effect both tissue injury and remodelling. It is hoped that future therapy will be directed towards specific leukocyte types, without overtly compromising essential host defence responses. One obvious target is leukocyte recruitment. This necessitates a detailed understanding of underlying mechanisms, particularly those involving soluble chemoattractants signals and cell-cell adhesion molecules.

Development of an integrated model for heat transfer and dynamic growth of Clostridium perfringens during the cooling of cooked boneless ham.

Numerous small meat processors in the United States have difficulties complying with the stabilization performance standards for preventing growth of Clostridium perfringens by 1 log10 cycle during cooling of ready-to-eat (RTE) products. These standards were established by the Food Safety and Inspection Service (FSIS) of the US Department of Agriculture in 1999. In recent years, several attempts have been made to develop predictive models for growth of C. perfringens within the range of cooling temperatures included in the FSIS standards. Those studies mainly focused on microbiological aspects, using hypothesized cooling rates. Conversely, studies dealing with heat transfer models to predict cooling rates in meat products do not address microbial growth. Integration of heat transfer relationships with C. perfringens growth relationships during cooling of meat products has been very limited. Therefore, a computer simulation scheme was developed to analyze heat transfer phenomena and temperature-dependent C. perfringens growth during cooling of cooked boneless cured ham. The temperature history of ham was predicted using a finite element heat diffusion model. Validation of heat transfer predictions used experimental data collected in commercial meat-processing facilities. For C. perfringens growth, a dynamic model was developed using Baranyi's nonautonomous differential equation. The bacterium's growth model was integrated into the computer program using predicted temperature histories as input values. For cooling cooked hams from 66.6 degrees C to 4.4 degrees C using forced air, the maximum deviation between predicted and experimental core temperature data was 2.54 degrees C. Predicted C. perfringens growth curves obtained from dynamic modeling showed good agreement with validated results for three different cooling scenarios. Mean absolute values of relative errors were below 6%, and deviations between predicted and experimental cell counts were within 0.37 log10 CFU/g. For a cooling process which was in exact compliance with the FSIS stabilization performance standards, a mean net growth of 1.37 log10 CFU/g was predicted. This study introduced the combination of engineering modeling and microbiological modeling as a useful quantitative tool for general food safety applications, such as risk assessment and hazard analysis and critical control points (HACCP) plans.

Selective suppression of leukocyte recruitment in allergic inflammation

Allergic diseases result in a considerable socioeconomic burden. The incidence of allergic diseases, notably allergic asthma, has risen to high levels for reasons that are not entirely understood. With an increasing knowledge of underlying mechanisms, there is now more potential to target the inflammatory process rather than the overt symptoms. This focuses attention on the role of leukocytes especially Th2 lymphocytes that regulate allergic inflammation and effector cells where eosinophils have received much attention. Eosinophils are thought to be important based on the high numbers that are recruited to sites of allergic inflammation and the potential of these cells to effect both tissue injury and remodelling. It is hoped that future therapy will be directed towards specific leukocyte types, without overtly compromising essential host defence responses. One obvious target is leukocyte recruitment. This necessitates a detailed understanding of underlying mechanisms, particularly those involving soluble che-moattractants signals and cell-cell adhesion molecules.

Solubility, tensile, and color properties of modified soy protein isolate films.

Protein solubility (PS) values of different soy protein isolate (SPI) films were determined in water, 0.01 N HCl, 0.01 N NaOH, 4 M urea, and 0.2 M 2-mercaptoethanol. Tensile and color (L, a, and b values) properties of films also were determined. Control films were cast from heated (70 degrees C for 20 min), alkaline (pH 10) aqueous solutions of SPI (5 g/100 mL of water) and glycerin (50% w/w of SPI). Additional films were cast after incorporation of dialdehyde starch (DAS) at 10% w/w of SPI or small amounts of formaldehyde in the film-forming solutions. Also, control film samples were subjected to heat curing (90 degrees C for 24 h), UV radiation (51.8 J/m(2)), or adsorption of formaldehyde vapors. PS of control films was highest (P < 0.05) in 2-mercaptoethanol, confirming the importance of disulfide bonds in SPI film formation. All treatments were effective in reducing (P < 0.05) film PS in all solvents. Both DAS and adsorbed formaldehyde rendered the protein in films practically insoluble in all solvents. Adsorption of formaldehyde vapors and heat curing also substantially increased (P < 0.05) film tensile strength from 8.2 to 15.8 or 14.7 MPa, respectively. However, heat curing decreased (P < 0.05) film elongation at break from 30 to 6%. Most treatments had small but significant (P < 0.05) effects on b color values, with DAS-containing films having the greatest (P < 0. 05) mean b value (most yellowish). Also, DAS-containing, heat-cured, and UV-irradiated films were darker, as evidenced by their lower (P < 0.05) L values, than control films. It was demonstrated that PS of SPI films can be notably modified through chemical or physical treatments prior to or after casting.

Rheology of zein solutions in aqueous ethanol.

Aqueous ethanol solutions prepared with commercial zein exhibited Newtonian behavior. Temperature, zein concentration, and ratio of water to ethanol affected viscosity of the zein solutions. The influence of temperature on zein solution viscosity was expressed by an Arrhenius-type equation. As zein concentration increased, solution viscosity exponentially increased. Generally speaking, viscosity decreased when the ethanol concentration increased. Parameters were estimated for an Arrhenius-type equation to describe the viscosity as a function of temperature, zein concentration, and ethanol concentration.

Differences in body image and depression among obese women with and without binge eating disorder.

Obese individuals with binge eating disorder (BED) differ from obese non-binge eating (NBE) individuals in a number of clinically relevant ways. This study examined attitudinal responses to various measures of body image in women seeking obesity treatment, by comparing NBE participants (n = 80) to those with BED (n = 48). It was hypothesized that women with BED would demonstrate greater attitudinal disturbance of body image compared to NBE individuals. It was further hypothesized that significant differences between groups would remain after statistically controlling for degree of depression. Consistent with the primary hypothesis, BED participants reported significantly increased attitudinal disturbance in body dissatisfaction and size perception compared to NBE participants. Although shared variance was observed between measures of depression and body image on some items, several aspects of increased body image disturbance remained after statistically controlling for depression. Treatment implications and recommendations for future research are discussed.

Onset of binge eating, dieting, obesity, and mood disorders among subjects seeking treatment for binge eating disorder.

Binge eating disorder (BED) identified in adulthood is often clinically associated with obesity and a lifetime history of affective disorders. Several authors have suggested that dieting may predispose individuals to binge eating which then may lead to obesity. However, few BED studies have examined the chronology of the onset of binge eating, dieting, obesity, and mood disorders. This study evaluated retrospective reports from 30 women participating in a BED treatment study. Although the majority of subjects in this adult sample were obese, initiation of binge eating behavior usually occurred during adolescence at a time when most subjects reported being of normal weight. Obesity developed several years after the age of onset of meeting BED criteria. Onset of binge eating usually predated that of dieting or major depressive disorder in the majority of subjects. The results support the importance of early intervention for binge eating.