Sensitive detection of sulfhydryl groups in surface-confined metallothioneins and related species via ferrocene-capped gold nanoparticle/streptavidin conjugates

Metallothionein (MT), a cysteine-rich metalloprotein that is purported to play an important role in heavy metal accumulation and detoxification, and its related peptidic species were attached onto dithiobissuccinimidyl propionate self-assembled monolayers. The spatially accessible sulfhydryl groups present in these immobilized biomolecules, tagged with N-biotinoyl-N'-[6-maleimidohexanoyl]hydrazide, were detected voltammetrically at a sensitive level via the use of ferrocene (Fc)-capped gold nanoparticle/streptavidin conjugates. The method was established first by examining relatively simple peptides (e.g., glutathione). For the hexapeptidic species that resembles the N-terminus of MT with a sequence of Lys-Cys-Thr-Cys-Cys-Ala, concentration levels as low as 0.050 nM can be determined. Such a remarkable sensitivity is attributed to the presence of a large number of Fc caps present at each gold nanoparticle, which enhances the detection of a small number of surface-bound sulfhydryl groups. Microgravimetric measurements, performed with a quartz crystal microbalance, were used in tandem with voltammetry to quantify the number of tagged sulfhydryl groups. Through extraction of the metals present in MT adsorbate, it is demonstrated that this amplified voltammetric detection is also suitable for the investigation of the variation of the number of sulfhydryl groups present at an electrode and sensitive to the change of surface structure of an immobilized biomolecule. This work represents a new method for the determination of sulfhydryl groups inherent in surface-bound proteins or peptides and can facilitate the study on the environmental issues related to MTs.     

Effect of vitamin beverages on vitamin sufficiency of the workers of Pskov Hydroelectric Power-Plant

The research of influence of vitamin complexes in the form of a drink or kissel on vitamin sufficiency of working persons has been carried out. Long inclusion (6,5 months) in a diet of vitamin drinks containing about 80% from recommended daily consumption of vitamins, was accompanied by trustworthy improvement of vitamins C and B6 sufficiency and prevention of seasonal deterioration of beta-carotene status. As initially surveyed have been well provided with vitamins A and E, their blood serum level increase had not occurred.     

Assessment of nutritional status of patients in the later period after renal transplantation

This article summarizes the modern approach for estimation of nutritional status (medical history, anthropometric, clinical and biochemical measures) in patients in the late period after kidney transplantation. It is showed that main complications in the late posttransplant period (cardiovascular diseases, diabetes, obesity, malnutrition) determine the need of complex assessment of nutritional status in these patients with the object of improve outcomes after transplantation.     

Effect of coenzyme Q10 and taurine on the availability of vitamins in the rat experiment

It has been observed that coenzyme Q10 (100 mg per 1 kg body mass) and taurine (1% in drinking water) treatment of rats has differently directed effect on vitamin A and E level in liver and blood serum. Coenzyme Q10 consumption has been accompanied with a tendency to increasing or an increase of vitamin content, while taurine consumption lead to the reverse effect. Both coenzyme Q10 and taurine addition caused diene conjugates decrease in blood serum. Supplementary coenzyme Q10 or taurine intake did not influence on rat liver vitamin B1 and B2 content.     

A microbeam study of DNA double-strand breaks in bystander primary human fibroblasts

Radiation-induced bystander effect has been well documented. However, the mechanisms are poorly understood. How we incorporate this effect into the classical models of risk assessment remains an open question. Here, the induction of bystander effect was studied by assessing DNA double-strand break (DSB) formation in situ with the rapid and sensitive gamma-H2AX focus formation assay. Utilising the Columbia University single-cell microbeam system to deliver 2 or 20 individual alpha particles to selected cell nuclei in a precisely known proportion of cells in a population, the induced DNA DSB incidences were quantified 30 min and 18 h post-IR. The increase in DNA DSB incidence in bystander cells lacked of a linear dose response indicating that neither the dose of irradiation nor proportion of irradiated cells in a population, is a critical parameter. This study confirms a binary all-or-nothing model of triggering the bystander response. The delay and persistence of the bystander response suggests a different mechanism of DSB induction in bystander cells than in directly irradiated cells.     

Effects of grass silage and soybean meal supplementation on milk production and milk fatty acid profiles of grazing dairy cows

The effects of supplementation with grass silage and replacement of some corn in the concentrate with soybean meal (SBM) on milk production, and milk fatty acid (FA) profiles were evaluated in a replicated 4 × 4 Latin square study using 16 dairy cows grazing pasture composed of ryegrass, Kentucky bluegrass, and white clover. Each experimental period lasted for 3 wk. The 4 dietary treatments were PC, 20 h of access to grazing pasture, supplemented with 6 kg/d of corn-based concentrate mixture (96% corn; C); PCSB, 20 h of access to grazing pasture, supplemented with 6 kg/d of corn- and SBM-based concentrate mixture (78% corn and 18% SBM; CSB); SC, 7 h of access to grazing pasture during the day and 13 h of ad libitum access to grass silage at night, supplemented with 6 kg/d of C concentrate; and SCSB, 7 h of access to grazing pasture during the day and 13 h of ad libitum access to grass silage at night, supplemented with 6 kg/d of CSB concentrate. The concentrate mixtures were offered twice each day in the milking parlor and were consumed completely. Grass silage supplementation reduced dietary crude protein and concentration of total sugars, and dietary SBM inclusion increased dietary crude protein concentration and decreased dietary starch concentration. Milk yield and energy-corrected milk were increased by SBM supplementation of cows with access to grass silage. Milk protein concentration was lower in cows offered grass silage, regardless of whether SBM was fed. Dietary SBM inclusion tended to increase milk fat concentration. Plasma urea N was reduced by silage feeding and increased by SBM supplementation. Supplementation with grass silage overnight could represent a useful strategy for periods of lower pasture availability. Dietary inclusion of SBM in solely grazing cows had no effects on milk production and composition, exacerbated the inefficient capture of dietary N, and increased diet cost. Grass silage supplementation affected milk FA profiles, increasing both the FA derived from de novo synthesis and those derived from rumen microbial biomass, and decreasing the sum of C18 FA (mostly derived from diet or from mobilization of adipose tissue reserves). Milk fat concentrations of conjugated linoleic acid cis-9, trans-11, vaccenic acid (18:1 trans-11), and linolenic acid (18:3n-3) were unaffected by grass silage supplementation, suggesting that partial replacement of pasture by unwilted grass silage does not compromise the dietary quality of milk fat for humans.     

Modern strategy of nutrition management in type 2 diabetes

In the review the current state of nutrition management for patients with type 2 diabetes is given. On the basis of literature data analysis it was showed that optimally balance diet in type 2 diabetes must be based in principles of the strict control of energy value, quantity and quality of protein, fat, carbohydrates, fiber, adequate contents of vitamin, macro- and micronutrients according the needs for every patient.     

The comparative analysis of the parameters used for diagnostics of lowering mineralization of osteous tissue

With the purpose of a choice of optimal biochemical parameters for individual diagnostics of bone tissue mineralization disturbances bone mineral density (T-criterion), a blood serum level of the transport form of vitamin D (25-OH D), osteocalcin and calcitonin, and also calcium daily urine excretion and calcium excretion in morning urinary portion per creatinin has been determined. The most informative parameters have appeared T-criterion, blood serum level of 25-OH D3) or osteocalcin due their interchangeability, and also calcium urine excretion per creatinin.