Variations in the chondroitin sulfate-protein linkage region of aggrecans from bovine nasal and human articular cartilages

Aggrecan-derived chondroitin sulfate (CS) chains, released by beta-elimination, were derivatized with p-aminobenzoic acid or p-aminophenol; radioiodinated; and subjected to graded or complete degradations by chondroitin ABC lyase to generate linkage region fragments of the basic structure DeltaGlyUA-GalNAc-GlcUA-Gal-Gal-Xyl-R (where DeltaGlyUA represents 4, 5-unsaturated glycuronic acid, and R is the adduct), by chondroitin AC lyase to generate the shorter fragment DeltaGlyUA-Gal-Gal-Xyl-R, or by chondroitin C lyase to generate the same fragment when it was linked to a 6-O-sulfated or unsulfated GalNAc at the nonreducing end. Fragments were separated by size using gel chromatography, by charge using ion-exchange chromatography, and by size/charge using electrophoresis and then characterized by stepwise degradations from the nonreducing end by using mercuric acetate to remove all terminal DeltaGlyUA, by bacterial glycuronidase to remove the same residue when linked to unsulfated or 6-O-sulfated GalNAc/Gal, by mammalian 4-sulfatase to remove sulfate from terminal GalNAc 4-O-sulfate, by chondro-4-sulfatase to remove 4-O-sulfate from other GalNAc/Gal residues, and by beta-galactosidase to remove terminal Gal. Results with CS from bovine nasal cartilage aggrecan show that, in nearly all chains, Xyl and probably also the first Gal are unsubstituted, whereas the second Gal is 4-O-sulfated in one CS chain out of five. The first disaccharide repeat is sulfated at C-4 of GalNAc in one chain out of three and unsulfated in the other two. A sulfated first disaccharide is always joined to an unsulfated GlcUA-Gal-Gal sequence. In contrast, CS from human articular cartilage usually has a sulfated first disaccharide repeat. In CS from young human cartilage, sulfate groups are mostly at C-4 of GalNAc in the major part of the chain, but at C-6 in the nonreducing distal portion. In CS from old cartilage, sulfation at C-6 of GalNAc is a major feature from the nonreducing end down to approximately positions 4 and 5 from the linkage region, where GalNAc 4-O-sulfate is common.     

Genetic and environmental influences on personality trait stability and growth during the transition to adulthood: A three-wave longitudinal study.

During the transition to adulthood individuals typically settle into adult roles in love and work. This transition also involves significant changes in personality traits that are generally in the direction of greater maturity and increased stability. Competing hypotheses have been offered to account for these personality changes: The intrinsic maturation hypothesis suggests that change trajectories are endogenous, whereas the life-course hypothesis suggests that these changes occur because of transactions with the social environment. This study investigated the patterns and origins of personality trait changes from ages 17 to 29 using 3 waves of Multidimensional Personality Questionnaire data provided by twins. Results suggest that (a) trait changes were more profound in the first relative to the second half of the transition to adulthood; (b) traits tend to become more stable during the second half of this transition, with all the traits yielding retest correlations between .74 and .78; (c) Negative Affectivity declined over time, and Constraint increased over time; minimal change was observed on agentic or communal aspects of Positive Emotionality; and (d) both genetic and nonshared environmental factors accounted for personality changes. Overall, these genetically informed results support a life-course perspective on personality development during the transition to adulthood. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A microfabricated inductively coupled plasma generator

The design, fabrication, and characterization of a surface micromachined plasma generator is described for the first time in this paper. The plasma is sustained without electrodes by inductively coupling a ~150-MHz current into a region of low-pressure gas, Both argon and air plasmas have been generated over a range of gas pressures from 0.1 to 10 torr (13.3-1333 Pa). Typically, the power used to sustain the plasma is 350 mW, although ~1.5 W is required to initiate the discharge. Network analysis of the plasma generator circuit shows that over 99% of the applied RF power can be absorbed by the device. Of this, ~50% is absorbed by the plasma and the remainder of the power is dissipated as ohmic heating. An argon ion current of up to 4.5 mA/cm² has been extracted from the plasma and the electron temperature is 52 000 K at 0.1 torr. This plasma source is intended for electronic excitation of gas samples so that the presence of impurities and toxins may be detected using optical emission spectroscopy     

Bioactivity of human growth hormone in serum: validation of an in vitro bioassay

GH, in clinical practice, is determined by RIA, but RIA estimates may not accurately reflect serum GH bioactivity. The available measures of GH bioactivity lack either sensitivity, specificity, or a physiologically relevant end point. The objective of this research was to develop a physiologically relevant GH bioassay which would not only measure the bioactivity of purified GH preparations, but would also have sufficient sensitivity to measure GH bioactivity in human serum. The method consisted of incubating murine 3T3-F442A adipocytes in serum-free medium containing BSA, 14C-glucose, and increasing concentrations of GH or test materials for 24 h, followed by measurement of conversion of glucose to lipid. Interference by nonspecific serum factors was reduced by the addition of 10 micrograms/liter insulin, 25 nM dexamethasone, and 37 nM estradiol to the medium. In the presence of 10 micrograms/liter insulin, 50 micrograms/liter insulin-like growth factor-1 did not alter the ability of GH to suppress lipid accumulation. Epinephrine and glucagon could suppress lipid accumulation but only at concentrations greatly in excess of the physiological range in serum. Twenty two thousand dalton hGH produced dose-dependent suppression of lipid accumulation which was linear between 0.625 and 10 micrograms/liter (r = 0.926; P = 0.0001) with a half-maximal response of 3.0 +/- 0.2 micrograms/liter (n = six experiments). The intra- and interassay coefficients of variation were 7% and 19%, respectively. The assay was specific for GH since addition of human PRL produced suppression of lipid accumulation only at concentrations where contamination of the preparation by GH became a significant factor. ACTH also suppressed lipid accumulation but only at doses of 1000 micrograms/liter or greater. Human placental lactogen and hLH, hFSH, and hTSH did not cross-react with GH in this assay. Addition of human serum did not alter the slope of ED50 of the GH dose-response curve. Pools of serum from prepubertal and pubertal boys and girls, subjects treated with arginine or insulin, a diabetic girl, and a boy with gigantism who had a serum GH content of 80 micrograms/liter by RIA and 40 micrograms/liter by bioassay, produced dose response curves parallel to that of the GH standard curve. Serum from patients with hypopituitarism did not produce significant suppression of lipid accumulation in any assay. Recovery of 5 micrograms/liter GH added to human serum was 94%. Twenty thousand dalton GH also suppressed lipid accumulation in this assay, but was 2-fold less potent than 22,000 dalton GH.(ABSTRACT TRUNCATED AT 400 WORDS)     

Organ-specific over-sulfation of glycosaminoglycans and altered extracellular matrix in a mouse model of cystic fibrosis

Very recently we proposed that hyperactivity of endothelial Ca2+/cGMP signaling under hyperglycemic conditions is due to superoxide anion (O2-) release. The present study was designed to investigate changes in endothelial glutathione (GSH) levels in response to high D-glucose and possible prevention of the high-D-glucose-initiated changes in Ca2+/cGMP signal by antioxidants. Under hyperglycemic conditions, GSH content increased by 29% within 4 h. Co-incubation with 10 mM GSH during high-D-glucose treatment normalized the Ca2+/cGMP response associated with an increase in GSH content by 222%. Vitamin C (250 microM) markedly diminished the high-D-glucose-mediated hyperreactivity of endothelial Ca2+ entry (by 40%) and Ca2+ release (by 52%). Similar to GSH, co-incubation with vitamin E (alpha-tocopherol; 50 micrograms/ml) and probucol (50 microM) completely prevented the high-D-glucose-initiated hyperreactivity of the endothelial Ca2+/cGMP response. Vitamin E, probucol, GSH and vitamin C diminished the high-D-glucose-mediated O2- release by 78, 65, 89 and 46%, respectively. These data suggest that antioxidants prevent high-D-glucose-initiated changes in endothelial Ca2+/cGMP response by scavenging the overshoot of O2-.