Comparative nutritional value for amino acids,oligopeptides and soybean protein

In recent years our view on the absorption of protein digestion products has undergone a radical change. We now believe that intralumen hydrolysis of intake proteins to free amino acids is only partial. It has thus been hypothesized that partial protein hydrolysates or oligopeptide mixtures are nutritionally superior to corresponding amino acid mixtures. With this consideration for a background, we developed a sophisticated technique of protease-catalyzed modification of soy protein to produce enzymatically modified proteins (EMP) having different levels of covalently attached methionine. We also carried out feeding tests with protein-malnourished rats, with the result that for their recovery from a state of malnutrition, an EMP containing peptide-bound methionine at 3% was significantly more effective than the corresponding amino acid mixture and even the soy protein itself. Discussions stress the importance of applying such a technique to production of an oligopeptide rather than a free amino acid nitrogen source as a foodstuff for therapeutic use.     

Are Monkeys Aesthetists? Rensch (1957) Revisited.

Three experiments assessed whether capuchin monkeys (Cebus apella) and squirrel monkeys (Saimiri sciureus) prefer regular and symmetrical visual patterns. Pictorial representations of faces were included in 1 stimulus set. When the monkeys could pick up and manipulate small cards bearing the stimuli, all preferences expressed by capuchins and most of those expressed by squirrel monkeys were for regular stimuli. Symmetry of the patterns was influential but not essential. Some preferences were also found for faces. When images of the patterns were presented on a touch screen, capuchins continued to express preferences especially for regular and symmetrical stimuli, but they showed some avoidance of faces. Squirrel monkeys responded less discriminatingly to the touch screen stimuli. The findings provide support for B. Rensch's (1957) claim that monkeys prefer visual stimuli that humans find aesthetically pleasing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Material design of bioabsorbable inorganic/organic composites for bone regeneration

Two new bioabsorbable inorganic/organic composite materials were developed for bone regeneration. One material used was beta-TCP/PLGC in which poly(L-lactide-co-glycolide-co-epsilon-caprolactone) and beta-tricalcium phosphate were used as the matrix and filler, respectively. The other material used was HAp/Col-a soft nanocomposite of hydroxyapatite and type I collagen. Using these composites, two bone implants were designed. The efficacy of these implants was investigated by applying them to the critical-sized bone defects that were created in the canine tibia. Although no tissue engineering techniques such as application of growth factors or stem cells was utilized, successful healing was observed. These results suggested that bone regeneration in the critical-sized defects is possible without the use of growth factors or stem cells if the materials and the bone implants are suitably designed.     

A Helix‐Stabilized Cell‐Penetrating Peptide as an Intracellular Delivery Tool

Two types of cationic cyclic α,α‐disubstituted α‐amino acids: Api (which possesses a lysine mimic side chain) and Api^C2Gu (which possesses an arginine mimic side chain), were developed. These amino acids were incorporated into an arginine‐based peptide sequence [(l ‐Arg‐l ‐Arg‐dAA)₃: dAA=Api or Api^C2Gu], and the relationship between the secondary structures of the resulting peptides and their ability to pass through cell membranes was investigated. The peptide containing Api^C2Gu formed a stable α‐helical structure and was more effective at penetrating cells than the nonhelical Arg nonapeptide (R₉). Furthermore, the peptide was able to deliver plasmid DNA into various types of cells in a highly efficient manner.     

Simultaneous determination of aminoglycoside antibiotics in milk by liquid chromatography with tandem mass spectrometry

A multiresidue method was developed for determination of nine aminoglycoside antibiotics (streptomycin, dihydrostreptomycin, spectinomycin, neomycin, kanamycin, gentamicin, destomycin A, apramycin, and tobramycin) in milk by LC/MS/MS. The drugs were extracted with 0.01 mol/L potassium dihydrogen phosphate containing 2% trichloroacetic acid, and the extracted solution was cleaned on cation-exchange cartridge columns (Oasis WCX and Oasis MCX). LC separation was performed on a TSK-gel VMpak25 column (50 mmx2.0 mm i.d.) using gradient elution with 0.1% formic acid and acetonitrile containing 0.1% formic acid as the mobile phase. Recoveries of the drugs spiked at 0.01 or 0.1 microg/g in milk ranged from 66.1 to 110.8%, with a coefficient of variation of less than 17.1%. Limits of quantification of the drugs in milk were 0.001 approximately 0.01 microg/g. This method was used for analysis of milk from a lactating cow treated for clinical mastitis with two intramammary infusions of kanamycin (KM). Milk samples were analyzed during the withdrawal times at 12-hour intervals. KM concentrations were lower than the Japanese provisional MRLs (0.4 microg/g) at 60 hours after infusion, and subsequently fell to 0.01 microg/g.     

Irradiation effect of carbon negative-ion implantation on polytetrafluoroethylene for controlling cell-adhesion property

We have investigated the irradiation effect of negative-ion implantation on the changes of physical surface property of polytetrafluoroethylene (PTFE) for controlling the adhesion property of stem cells. Carbon negative ions were implanted into PTFE sheets at fluences of 1 × 10¹⁴-1 × 10¹⁶ ions/cm² and energies of 5-20 keV. Wettability and atomic bonding state including the ion-induced functional groups on the modified surfaces were investigated by water contact angle measurement and XPS analysis, respectively. An initial value of water contact angles on PTFE decreased from 104° to 88° with an increase in ion influence to 1 × 10¹⁶ ions/cm², corresponding to the peak shifting of XPS C1s spectra from 292.5 eV to 285 eV with long tail on the left peak-side. The change of peak position was due to decrease of C-F₂ bonds and increase of C-C bonds with the formation of hydrophilic oxygen functional groups of OH and CO bonds after the ion implantation. After culturing rat mesenchymal stem cells (MSC) for 4 days, the cell-adhesion properties on the C⁻-patterned PTFE were observed by fluorescent microscopy with staining the cell nuclei and their actin filament (F-actin). The clear adhesion patterning of MSCs on the PTFE was obtained at energies of 5-10 keV and a fluence of 1 × 10¹⁵ ions/cm². While the sparse patterns and the uncontrollable patterns were found at a low fluence of 3 × 10¹⁴ ions/cm² and a high fluence of 3 × 10¹⁵ ions/cm², respectively. As a result, we could improve the surface wettability of PTFE to control the cell-adhesion property by carbon negative-ion implantation.     

Neuroimmunological Implications of AQP4 in Astrocytes

The brain has high-order functions and is composed of several kinds of cells, such as neurons and glial cells. It is becoming clear that many kinds of neurodegenerative diseases are more-or-less influenced by astrocytes, which are a type of glial cell. Aquaporin-4 (AQP4), a membrane-bound protein that regulates water permeability is a member of the aquaporin family of water channel proteins that is expressed in the endfeet of astrocytes in the central nervous system (CNS). Recently, AQP4 has been shown to function, not only as a water channel protein, but also as an adhesion molecule that is involved in cell migration and neuroexcitation, synaptic plasticity, and learning/memory through mechanisms involved in long-term potentiation or long-term depression. The most extensively examined role of AQP4 is its ability to act as a neuroimmunological inducer. Previously, we showed that AQP4 plays an important role in neuroimmunological functions in injured mouse brain in concert with the proinflammatory inducer osteopontin (OPN). The aim of this review is to summarize the functional implication of AQP4, focusing especially on its neuroimmunological roles. This review is a good opportunity to compile recent knowledge and could contribute to the therapeutic treatment of autoimmune diseases through strategies targeting AQP4. Finally, the author would like to hypothesize on AQP4’s role in interaction between reactive astrocytes and reactive microglial cells, which might occur in neurodegenerative diseases. Furthermore, a therapeutic strategy for AQP4-related neurodegenerative diseases is proposed.