Relationship between condensed tannin structures and their ability to precipitate feed proteins in the rumen.

Background: Tannins can bind to and precipitate protein by forming insoluble complexes resistant to fermentation and with a positive effect on protein utilisation by ruminants. Three protein types, Rubisco, rapeseed protein and bovine serum albumin (a single high-molecular weight protein), were used to test the effects of increasing concentrations of structurally different condensed tannins on protein solubility/precipitation.

Results: Protein type (PT) influenced solubility after addition of condensed tannins (P < 0.

Effect of water hyacinth (eichhornia crassipes) silage on intake and nutrient digestibility in cattle fed rice straw and cottonseed cake.

Four crossbred Sindhi heifers with an average body weight (BW) of 135 kg and a mean age of 17 months were used to investigate the effect of feeding different combinations of rice straw and ensiled water hyacinth (EWH) supplemented with a source of protein in the form of cottonseed cake (CSC) on intake and digestibility. Four treatments consisting of graded levels of EWH were arranged in a 4×4 Latin square. The levels of EWH were set at: 0 (EWH0), 15 (EWH15), 30 (EWH30), and 45% (EWH45) of an expected total dietary dry matter (DM) intake of 30 g total DM per kg BW per day.

In vitro protein degradation of 38 sainfoin accessions and its relationship to tannin content by different assays.

This study compared 38 sainfoin and 2 Lotus accessions to their respective tannin contents, N buffer solubility, and in vitro protein degradation. Tannin contents were measured by a protein precipitation method using either bovine serum albumin or Rubisco and by the colorimetric HCl/butanol method. Precipitation of bovine serum albumin and Rubisco was highly correlated (R(2) = 0.

Speciation of selenium dietary supplements; formation of S-(methylseleno)cysteine and other selenium compounds.

Speciation of selenium is of interest because it is both essential and toxic to humans, depending on the species and the amount ingested. Following indications that selenium supplementation could reduce the incidence of some cancers, selenium-enriched yeast and other materials have been commercialized as supplements. Most dramatically however, the SELECT trial that utilized l-selenomethionine as the active supplement was terminated in 2008 and there is much debate regarding both the planning and the results of efficacy studies.

High incidence of adverse events in healthy volunteers receiving rifampicin and adjusted doses of lopinavir/ritonavir tablets.

Objective: Previous research in healthy volunteers has demonstrated that rifampicin and adjusted doses of lopinavir/ritonavir soft-gel capsules resulted in adequate exposure to lopinavir. Our objective was to study the combined use of rifampicin and the newly introduced lopinavir/ritonavir tablets.

Methods: A total of 40 healthy volunteers were planned to start with 600 mg rifampicin once daily from days 1-5.

Heterologous expression, purification, and characterization of recombinant rat cysteine dioxygenase.

Cysteine dioxygenase (CDO, EC 1.13.11.

Chromatographic speciation of anionic and neutral selenium compounds in Se-accumulating Brassica juncea (Indian mustard) and in selenized yeast.

Selenium-accumulating plants such as Brassica juncea (Indian mustard) concentrate the element in plant shoots and roots. Such behavior may provide a cost-effective technology to clean up contaminated soils and waters that pose major environmental and human health problems (phytoremediation). Such ability to transform selenium into bioactive compounds has important implications for human nutrition and health.

Selective detection and identification of Se containing compounds--review and recent developments.

The complexity of selenium (Se) chemistry in the environment and in living organisms presents broad analytical challenges. The selective qualitative and quantitative determination of particular species of this element is vital in order to understand selenium's metabolism and significance in biology, toxicology, clinical chemistry and nutrition. This calls for state-of-the-art analytical techniques such as hyphenated methods that are reviewed with particular emphasis on interfaced separation with element-selective detection and identification of the detected selenium compounds.

Effect of inhibitor concentration and end-product accumulation on estimates of ruminal in vitro protein degradation.

Effects of varying the concentrations of hydrazine sulfate (HS) and chloramphenicol (CAP), inhibitors of microbial-N uptake and protein synthesis, on rates of protein degradation estimated from net appearance of NH3 and total amino acids (TAA) were studied in a ruminal in vitro fermentation system. Without inhibitors, recoveries of N added as NH3 and TAA were 4 and 6% after 4-h incubations, and apparent degradation rates estimated from release of NH3 and TAA for casein, solvent soybean meal (SSBM), and expeller soybean meal (ESBM) approached 0. Increasing inhibitor concentrations from the standard amounts of 1 mM HS plus 30 mg of CAP/L to 2 mM HS plus 90 mg of CAP/ L gave rise to numerically greater N recoveries and degradation rates, but these differences were not statistically significant.

Extraction of arsenic species from spiked soils and standard reference materials.

The abilities of various extractants to recover four arsenic species [As(iii), As(v), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA)] from soils spiked with 20 micro g g(-1) As were investigated. The extractants were water, buffer solutions (citrate and ammonium dihydrogen phosphate), acidic solutions (phosphoric acid and acetic acid), a basic solution (sodium hydroxide) and household chemicals (vinegar and Coca Cola). Gentle shaking at room temperature with each extractant for 24 h gave different recoveries for the different arsenic species.

Identification and synthesis of a novel selenium-sulfur amino acid found in selenized yeast: Rapid indirect detection NMR methods for characterizing low-level organoselenium compounds in complex matrices.

After proteolytic digestion, aqueous extraction, and derivatization with diethyl pyrocarbonate or ethyl chloroformate, HPLC-inductively coupled plasma (ICP)-MS, GC-atomic emission detection (AED), and GC-MS analysis of high-selenium yeast stored at room temperature for more than 10 years showed selenomethionine as the major Se product along with substantial amounts of selenomethionine selenoxide hydrate and the previously unreported selenoamino acid having a Se-S bond, S-(methylseleno)cysteine. The identity of the latter compound was confirmed by synthesis. The natural product was shown to be different from a synthetic sample of the isomeric compound Se-(methylthio)selenocysteine.

Modern trends in the speciation of selenium by hyphenated techniques.

The complexity of selenium speciation in the environment and in living organisms results in broad analytical challenges. The importance of the selective determination of the particular species of this element, to understand its metabolism and biological significance in clinical chemistry, biology, toxicology, and nutrition, calls for state-of-the-art analytical techniques. In this paper hyphenated techniques are evaluated with particular emphasis on interfaced separation with element-selective detection and identification of the selenium compounds detected.