Implications of enolase in the RANKL-mediated osteoclast activity following spinal cord injury

Spinal Cord Injury (SCI) is a debilitating condition characterized by damage to the spinal cord, resulting in loss of function, mobility, and sensation. Although increasingly prevalent in the US, no FDA-approved therapy exists due to the unfortunate complexity of the condition, and the difficulties of SCI may be furthered by the development of SCI-related complications, such as osteoporosis. SCI demonstrates two crucial stages for consideration: the primary stage and the secondary stage. While the primary stage is suggested to be immediate and irreversible, the secondary stage is proposed as a promising window of opportunity for therapeutic intervention. Enolase, a metabolic enzyme upregulated after SCI, performs non-glycolytic functions, promoting inflammatory events via extracellular degradative actions and increased production of inflammatory cytokines and chemokines. Neuron-specific enolase (NSE) serves as a biomarker of functional damage to neurons following SCI, and the inhibition of NSE has been demonstrated to reduce signs of secondary injury of SCI and to ameliorate dysfunction. This Viewpoint article involves enolase activation in the regulation of RANK-RANKL pathway and summarizes succinctly the mechanisms influencing osteoclast-mediated resorption of bone in SCI. Our laboratory proposes that inhibition of enolase activation may reduce SCI-induced inflammatory response and decrease osteoclast activity, limiting the chances of skeletal tissue loss in SCI.     

Simple phase meter with lead/lag indication

A simple and inexpensive circuit for measuring the phase angle difference between two waves with lead/lag indication is described. The proposed circuit may be adopted in the laboratory as an attachment to a commercially available analogue/ digital multimeter to measure the phase difference. The response is linear over a range 0 to + 180^° and is unaffected by the input frequencies in the range 6 Hz–1.2 kHz. For distorted waveforms, the paper also gives a simple scheme to measure the displacement angle which in turn suggests its use in a high-power-factor self-compensated alternating voltage controller.     

Antioxidative ability of native and thermized sour whey in oxidation‐catalysed model systems†

Antioxidative properties of sour (cottage) were evaluated with (thermized) and without (native) heat treatment (80°C for 30 min). A model system comprising a Tween 20 stabilized peanut oil in phosphate buffer (pH 7.0) emulsion containing lipid oxidation catalysts, FeCl ₃, H₂O₂ and ascorbate was used. Native sour whey powder (SWP) was significantly better than thermized whey in terms of limiting the formation of thiobarbituric acid‐reactive substances and peroxide value. Antioxidative ability was best at pH 3.0 and decreased with increasing pH. SWP (20%, w/v) was significantly better than all commonly used antioxidants tested after 96 h of incubation at 40°C.     

Emulsifying Properties of Food Proteins: Development of a Standardized Emulsification Method

A recirculating valve-homogenizer was used to compare the emulsifying properties of bovine serum albumin and milk proteins. The energy input per unit volume was directly obtained from the mean maximum valve head pressure per stroke. The mean maximum velocity of the emulsion in the valve head was 83m sec^?1 during a valve opening time of 150 × 10 ^?3 sec reflecting a large velocity gradient per stroke of 4.2 × 10^?6 m³ The method detected changes in the emulsifying activity of proteins resulting from chemical modification, and from process or environmental factors, e.g., ionic strength. The valve-head pressure profile was used to compare the fluidity of the emulsions at different levels of energy input per unit volume (E) and an apparent viscosity index (AVI) has been proposed.     

Emulsifying Properties of Food Proteins: Bovine Mi cellar Casein

The capacity of micellar casein isolated from bovine milk to stabilize oil in water (0:w) emulsions was studied. Emulsion surface area per unit mass of protein, i.e., emulsifying activity (EA), was highest at a protein concentration of 1% and o:w ratio of 1:9. The surface concentration of micellar casein was related to the o:w ratio being highest at an o:w of 4:6. Interfacial surface area decreased at pH 6.7 reflecting micellar stability and improved with increasing pH apparently because of destabilization of the casein micelle. Emulsion stability was high when the EA was high. The apparent viscosity of the emulsions was inversely related to EA.     

Strategies to assemble therapeutic and imaging molecules into inorganic nanocarriers

Inorganic nanocarriers are potent candidates for delivering conventional anticancer drugs, nucleic acid-based therapeutics, and imaging agents, influencing their blood half-lives, tumor targetability, and bioactivity. In addition to the high surface area-to-volume ratio, they exhibit excellent scalability in synthesis, controllable shape and size, facile surface modification, inertness, stability, and unique optical and magnetic properties. However, only a limited number of inorganic nanocarriers have been so far approved for clinical applications due to burst drug release, poor target specificity, and toxicity. To overcome these barriers, understanding the principles involved in loading therapeutic and imaging molecules into these nanoparticles (NPs) and the strategies employed in enhancing sustainability and targetability of the resultant complexes and ensuring the release of the payloads in extracellular and intracellular compartments of the target site is of paramount importance. Therefore, we will shed light on various loading mechanisms harnessed for different inorganic NPs, particularly involving physical entrapment into porous/hollow nanostructures, ionic interactions with native and surface-modified NPs, covalent bonding to surface-functionalized nanomaterials, hydrophobic binding, affinity-based interactions, and intercalation through co-precipitation or anion exchange reaction.     

Physicochemical properties of low-fat and full-fat Cheddar cheeses

Low-fat (6% fat) and full-fat (32% fat) Cheddar cheese was manufactured and aged up to 6–9 months at 5°C. The objective was to study the impact of fat on the physicochemical properties of Cheddar cheese. Total soluble nitrogen (TSN) and protein nitrogen (TPSN) in aqueous extracts were determined by the Kjeldahl method. The peptide content of each cheese was determined with reverse phase chromatography (RPC). Low-fat Cheddar (LFC) had a markedly higher peptide content than full-fat Cheddar (FFC). The overall peptide quantity increased with age with a marked increase in hydrophobic peptide content. Rheological properties were determined using an Instron Universal Testing Machine. LFC had significantly higher stress values, indicating hard and rubbery texture, than FFC. Furthermore, LFC had lower strain values, indicating crumbliness.     

Water Plasticization and Crystallization of Lactose in Spray-dried Lactose/Protein Mixtures

ABSTRACT: Water plasticization led to depression of the glass transition causing significant changes in the physico-chemical and crystallization properties in storage of lactose and lactose/protein (3:1) mixtures. Glass transition (Tg) and crystallization temperatures (Tcr) were determined using differential scanning calorimetry. Whey protein isolate (WPI), albumin, and gelatin increased the Tg of dry powders; when Na-caseinate was used, a decrease was observed. In the presence of proteins and water, a decrease of Tg at aw ≤ 0.23 was observed. At aw ≤ 0.33, proteins increased the Tg In the anhydrous state, Tcr decreased in the presence of proteins possibly because of browning. WPI, Na-caseinate, albumin, and gelatin delayed lactose crystallization in humidified samples, with albumin and gelatin delaying it more than WPI at all storage humidities. Temperature difference between an observed instant crystallization and glass transition (Tcr to Tg) was larger for humidified samples containing proteins than for lactose. Various proteins and water affect crystallization behavior of amorphous lactose differently in spray-dried powders. This should be considered in evaluating sugar crystallization properties in food products including dairy powders.     

EFFICACY OF SOUR WHEY AS A SHELF‐LIFE ENHANCER: USE IN ANTIOXIDATIVE EDIBLE COATINGS OF BEEF STEAK*

ABSTRACT

Sour whey powder (SWP) based edible coatings, with and without carboxymethyl cellulose (CMC), were used to reduce oxidative degradation of cut beef steak stored at 2C for 5 days. Comparison was with calcium caseinate (CC) and soy protein isolate (SPI). Colorimetric measurements showed the mean of the color consistency index for L*, a*and b*scales of SWP to be highest with (18.3) and without CMC (19.8). Control gave a significantly lower value of 10.6. The percent inhibition of thiobarbituric acid reactive substances (TBARS) compared to control was 40.9, 38.9 and 48.9%, respectively for CC, SPI and SWP. In the same order, this value increased to 51.9, 45.1 and 59.2% when CMC was added to the coating. The peroxide value was also significantly reduced by SWP. Oxidative degradation as reflected by an increase in carbonyls and decrease in sulfhydryls was also reduced by SWP and it was better at this than the other proteins. Moisture barrier property of SWP based coating was the best and CMC significantly enhanced this property of CC and SPI though they did not fare well by themselves. Data show that SWP can effectively be used to extend quality and shelf life of beef steak.

PRACTICAL APPLICATIONS

In 2006, the U.S.A. produced more than 11.95 million metric tons of beef. Most of this was consumed as hamburger meat and steaks. Unfortunately, once the animal is slaughtered, meat undergoes oxidative degradation. Retail cut meats are particularly susceptible. Various antioxidative coatings have been tried with varying levels of success. The industry is keen for inexpensive and natural means. Recently, we successfully used sour whey, a byproduct of cottage cheese and/or caseinate manufacture, as natural antioxidative coating to extend shelf life of cut vegetables and apples. This part of our study investigates its efficacy in reducing oxidative degradation of retail cut beef steaks.