Equilibrium of adsorption of mixed milk protein/surfactant solutions at the water/air interface

Ellipsometry and surface profile analysis tensiometry were used to study and compare the adsorption behavior of beta-lactoglobulin (BLG)/C10DMPO, beta-casein (BCS)/C10DMPO and BCS/C12DMPO mixtures at the air/solution interface. The adsorption from protein/surfactant mixed solutions is of competitive nature. The obtained adsorption isotherms suggest a gradual replacement of the protein molecules at the interface with increasing surfactant concentration for all studied mixed systems. The thickness, refractive index, and the adsorbed amount of the respective adsorption layers, determined by ellipsometry, decrease monotonically and reach values close to those for a surface covered only by surfactant molecules, indicating the absence of proteins from a certain surfactant concentration on. These results correlate with the surface tension data. A continuous increase of adsorption layer thickness was observed up to this concentration, caused by the desorption of segments of the protein and transforming the thin surface layer into a rather diffuse and thick one. Replacement and structural changes of the protein molecules are discussed in terms of protein structure and surface activity of surfactant molecules. Theoretical models derived recently were used for the quantitative description of the equilibrium state of the mixed surface layers.

AttenuatedSalmonellaandShigellaas Carriers for DNA Vaccines

The discovery that genes can be functionally transferred from bacteria to mammalian cells has suggested the possible use of bacterial vectors as gene delivery vehicles for vaccines. Attenuated invasive human intestinal bacteria, such as Salmonella and Shigella, have been used as plasmid DNA vaccine carriers and their potency has been evaluated in several animal models. This delivery system allows the administration of DNA vaccines together with associated bacterial immunostimulators directly to professional antigen presenting cells via human mucosal surfaces. Various strategies have been taken to improve the use of this delivery system to achieve robust immune responses at both mucosal and systemic sites of the immunized animals.

Effect of early insulin therapy on nuclear factor kappaB and cytokine gene expressions in the liver and skeletal muscle of high-fat diet, streptozotocin-treated diabetic rats

To clarify the effect of early insulin therapy on nuclear factor kappaB (NFkappaB) pathway and inflammatory cytokine responses in the liver and skeletal muscle in type 2 diabetes. High-fat diet and low dose streptozotocin (STZ) induced diabetic rats were given NPH insulin or gliclazide for 3 weeks initiated at the 3rd day after STZ injection as early treatment and NPH for 3 weeks at 1 month as late treatment. Intraperitoneal glucose tolerance test (IPGTT) was performed at 3rd day after the end of treatment. Early interventions caused a decrease in glucose-insulin index in IPGTT, promoted glucose transporter 4 (Glut4) gene and protein expressions in muscle and reduced phosphoenolpyruvate carboxykinase (PEPCK) protein levels in the liver. There was an increase in inhibitor kappaB (IkappaBalpha) protein and a decrease in NFkappaB p65 DNA binding activity. A decreased level in mRNAs encoding tumor necrosis factor (TNF)alpha in the liver and muscle and interleukin (IL)-1beta in the liver were observed. Our results suggested that early insulin treatment inhibits NFkappaB activity and inflammatory cytokine responses in the liver and skeletal muscle that were involved in the amelioration of insulin resistance in type 2 diabetic rats.

Treatment with anti-CC chemokine receptor 3 monoclonal antibody or dexamethasone inhibits the migration and differentiation of bone marrow CD34 progenitor cells in an allergic mouse model

BACKGROUND

The migration and in situ differentiation of CD34(+) progenitors contribute to inflammatory eosinophilia in asthma and corticosteroids have been widely used in asthma. However, little is know about whether and how corticosteroids modulate the migration and differentiation of CD34(+) progenitors. This study was aimed to investigate the impact of anti-CC chemokine receptor 3 (CCR3) or dexamethasone on inflammatory eosinophilia in asthma and possible mechanism(s) underlying the action of dexamethasone or anti-CCR3 on migration and differentiation of CD34(+) progenitors in asthmatic context.

METHODS

Using an asthmatic mouse model, airway inflammation of anti-CCR3- or dexamethasone-treated mice and that of controls were characterized. And the migration and differentiation of CD34(+) progenitor cells were analyzed in vivo, ex vivo or in vitro.

RESULTS

Treatment with anti-CCR3 or dexamethasone significantly inhibited allergen-induced eosinophilia and CD34(+) progenitor cell infiltration in the lung, which was accompanied by lower levels of airway hyper-responsiveness and mucus production. Moreover, anti-CCR3 inhibited the eotaxin-mediated migration and IL-5/eotaxin-induced differentiation of CD34(+) progenitors in vitro. Dexamethasone was also shown to mitigate eotaxin-mediated migration and IL-5 or eotaxin-promoted differentiation of CD34(+) progenitor cells ex vivo, which were associated with the down-regulation of CCR3 expression on bone marrow progenitor cells.

CONCLUSIONS

Treatment with anti-CCR3 or dexamethasone can inhibit the migration and differentiation of CD34(+) progenitor cells by regulating the eotaxin/CCR3 axis in asthmatic mice. Our findings provide new insights into understanding the mechanism(s) underlying the action of dexamethasone and CCR3-mediated signaling in allergic inflammation and aid in the design of new immunotherapy for intervention of human asthma.

Modeling of Nociceptor Transduction in Skin Thermal Pain Sensation

All biological bodies live in a thermal environment with the human body as no exception, where skin is the interface with protecting function. When the temperature moves out of normal physiological range, skin fails to protect and pain sensation is evocated. Skin thermal pain is one of the most common problems for humans in everyday life as well as in thermal therapeutic treatments. Nocicetors (special receptor for pain) in skin play an important role in this process, converting the energy from external noxious thermal stimulus into electrical energy via nerve impulses. However, the underlying mechanisms of nociceptors are poorly understood and there have been limited efforts to model the transduction process. In this paper, a model of nociceptor transduction in skin thermal pain is developed in order to build direct relationship between stimuli and neural response, which incorporates a skin thermomechanical model for the calculation of temperature, damage and thermal stress at the location of nociceptor and a revised Hodgkin–Huxley form model for frequency modulation. The model qualitatively reproduces measured relationship between spike rate and temperature. With the addition of chemical and mechanical components, the model can reproduce the continuing perception of pain after temperature has returned to normal. The model can also predict differences in nociceptor activity as a function of nociceptor depth in skin tissue.

Metalloelastase in lungs and alveolar macrophages is modulated by extracellular substance P in mice

Metalloelastase (MMP-12), mainly produced by macrophages, has been shown to play a key role in the pathogenesis of emphysema in animal models. Chronic cigarette smoke increases pulmonary MMP-12, which is closely correlated with an elevation of pulmonary substance P (SP). Because alveolar macrophages (AMs) contain the neurokinin-1 receptor (NK1R), we tested whether SP was able to trigger the upregulation of MMP-12 synthesis in AMs by acting on the NK1R. AMs isolated from bronchoalveolar lavage cells in C3H/HeN mice were cultured with control medium or SP that was coupled without or with NK1R antagonists (CP-99,994 or aprepitant) for 24 h. We found that SP significantly increased the mRNA of MMP-12 and NK1R by 11-fold and 82%, respectively, in AMs (P<0.05), and these responses were abolished by NK1R antagonists with little change in the cells' viability. Because pulmonary SP is primarily released by bronchopulmonary C-fibers (PCFs), we further asked whether destruction of PCFs would reduce SP and MMP-12. Two groups of mice were pretreated with vehicle and neonatal capsaicin (NCAP) to degenerate PCFs, respectively. Our results show that NCAP treatment significantly decreased mRNA and protein levels of SP associated with a reduction NK1R and MMP-12 in the lungs and AMs. These findings suggest that SP has a modulatory effect on pulmonary MMP-12 by acting on NK1R to trigger MMP-12 syntheses in the AMs.

Composition design for Laves phase-related body-centered cubic-V solid solution alloys with large hydrogen storage capacities

This paper analyzes the characteristics of alloy compositions with large hydrogen storage capacities in Laves phase-related body-centered cubic (bcc) solid solution alloy systems using the cluster line approach. Since a dense-packed icosahedral cluster A(6)B(7) characterizes the local structure of AB(2) Laves phases, in an A-B-C ternary system, such as Ti-Cr (Mn, Fe)-V, where A-B forms AB(2) Laves phases while A-C and B-C tend to form solid solutions, a cluster line A(6)B(7)-C is constructed by linking A(6)B(7) to C. The alloy compositions with large hydrogen storage capacities are generally located near this line and are approximately expressed with the cluster-plus-glue-atom model. The cluster line alloys (Ti(6)Cr(7))(100-x)V(x) (x = 2.5-70 at.%) exhibit different structures and hence different hydrogen storage capacities with increasing V content. The alloys (Ti(6)Cr(7))(95)V(5) and Ti(30)Cr(40)V(30) with bcc solid solution structure satisfy the cluster-plus-glue-atom model.

Recent progress in the development of inhibitors of human immunodeficiency virus (HIV) integrase for the management of HIV infection

Current therapy of acquired immune deficiency syndrome (AIDS) involves the use of a combination of at least three antiviral drugs to inhibit Human immunodeficiency virus 1 and 2 (HIV-1 and 2, in short HIV) replication via targeting of viral reverse transcriptase and protease. However, all anti-HIV drugs give rise to the new retroviral resistant strains. Therefore, new therapeutic agents against the emerging resistant HIV strains without secondary effects are very much needed. In HIV infection, the integration of viral DNA obtained from RNA genome into the chromosome of the host cell by viral integrase (IN) is essential for an effective viral replication. Moreover, no cellular IN has been found in the cells suggesting that viral IN appears to be one of the best candidates for the development of an antiviral drug. In recent years, promising results have proved that IN inhibitors are useful for treatment of retroviral infections. In this review, we briefly introduce IN and summarize potential inhibitors of IN, which are classified into several groups according to their origin and chemical structure. The resistance to the IN inhibitors is also discussed. Currently, several IN inhibitors are either being used in the clinical treatment or tested in clinical trials. Nevertheless, a great effort must be made to elicit wide knowledge with respect to the design of better viral inhibitors and the synthesis of new chemical derivatives with an anti-HIV activity.

Skin biothermomechanics for medical treatments

Electromagnetic heating, such as microwave, radiofrequency, and laser etc., is widely used in medical treatments. Recent advances in these technologies resulted in remarkable developments of thermal treatments for a multitude of diseases and injuries involving skin tissue. The comprehension of heat transfer and related thermomechanics in skin tissue during these treatments is thus of great importance, and can contribute to the further developments of these medical applications. Biothermomechanics of skin is highly interdisciplinary, involving bioheat transfer, burn damage, biomechanics, and physiology. The aim of this study is to develop a computational approach to examine the heat transfer process, heat-induced mechanical response, as well as the associated pain level, so that the differences among the clinically applied heating modalities can be quantified. In this paper, numerical simulation with the finite difference method (FDM) was used to analyze the temperature, burn damage, and thermal stress distributions in the skin tissue subjected to various thermal treatments. The results showed that the thermomechanical behavior of skin tissue is very complex: blood perfusion has little effect on thermal damage, but a large influence on skin temperature distribution, which, in turn, influences significantly the resulting thermal stress field; for laser heating, the peak temperature is higher for lasers with shorter wavelengths, but the peak is closer to the skin surface; the thermal stress due to laser and microwave heating is mainly limited to the top epidermis layer due to the exponential decrease of heat generation along skin depth; the thin (and commonly overlooked) stratum corneum layer dominates the thermomechanical response of skin tissue.