Discriminating neural representations of physical and social pains: how multivariate statistics challenge the "shared representation" theory of pain.

Overlapping functional magnetic resonance imaging (fMRI) activity elicited by physical pain and social rejection has posited a common neural representation between the two experiences. However, Woo and colleagues (Nat Commun 5: 5380, 2014) recently used multivariate statistics to challenge the "shared representation" theory of pain. This study has implications in the way results from fMRI studies are interpreted and has the potential of broadening our understanding of different pain states and future development of personalized medicine.

Glucose transport and microvillus membrane physical properties along the crypt-villus axis of the rabbit.

Both transport function and microvillus membrane physical properties evolve as the enterocyte matures and migrates up the crypt-villus axis. We isolated enriched fractions of villus tip, mid-villus, and crypt enterocytes from which microvillus membrane vesicles were prepared. Using this material we characterized the alterations that occur in microvillus membrane fluidity as the rabbit enterocyte matures and correlated these with kinetic studies of glucose transport. With increasing maturity the microvillus membrane becomes more rigid due to both an increase in the cholesterol/phospholipid ratio and alterations in individual phospholipid subclasses. Maximal rates of glucose transport were greatest in microvillus membrane vesicles prepared from mature cells. However, the glucose concentration producing half-maximal rates of transport (Km) was significantly lower in crypt microvillus membrane vesicles, suggesting that a distinct glucose transporter existed in crypt enterocytes. This distinction disappeared when differences between membrane lipid environments were removed. By fluidizing villus-tip microvillus membrane vesicles, in vitro, to levels seen in the crypt microvillus membrane, we observed a reduction in the Km of this transport system. These data suggest that the kinetic characteristics of the sodium-dependent glucose transporter are dependent upon its local membrane environment.

Distribution of antibody to hepatitis A antigen in a population of commerical plasma doners.

Plasma samples from 245 regular plasma donors for Plasma Alliance, Inc. (Knoxville, Tenn.) were tested for the presence of antibody to hepatitis A antigen. Antibody was detected at an immune adherence hemagglutination titer of 1:10 or greater in 37% (91 of 245) of the donors. A statistically significant difference in the frequency of anti-hepatitis A was found between the 18- to 29-year-old group (30%) and the 30- to 49-year-old group (57%). No significant differences between whites and blacks or males afemales were observed. Eighty percent of the donors were in the age range of 18 to 29 years, whereas 48% of the higher-titered plasmas (1:1,000 or greater) were in the 30 to 49 age group. By preselection of donors, it would be possible to produce an immune serum globulin with a specific anti-hepatitis A titer.

Lectin-mediated drug targeting: selection of valency, sugar type (Gal/Lac), and spacer length for cluster glycosides as parameters to distinguish ligand binding to C-type asialoglycoprotein receptors and galectins.

PURPOSE: Common oligosaccharides of cellular glycoconjugates are ligands for more than one type of endogenous lectin. Overlapping specificities to beta-galactosides of C-type lectins and galectins can reduce target selectivity of carbohydrate-ligand-dependent drug targeting. The purpose of this study is to explore distinct features of ligand presentation and structure for design of cluster glycosides to distinguish between asialoglycoprotein-specific (C-type) lectins and galectins. METHODS: Extent of binding of labeled sugar receptors to two types of matrix-immobilized (neo)glycoproteins and to cells was evaluated in the absence and presence of competitive inhibitors. This panel comprised synthetic mono-, bi-, and trivalent glycosides with two spacer lengths and galactose or lactose as ligand part. RESULTS: In contrast to C-type lectins of hepatocytes and macrophages, bi- and trivalent glycosides do not yield a notable glycoside cluster effect for galectins-1 and -3. Also, these Ca2+-independent galactoside-binding proteins prefer to home in on lactose-bearing glycosides relative to galactose as ligand, while spacer length requirements were rather similar. CONCLUSIONS: Trivalent cluster glycosides with Gal/GalNAc as ligand markedly distinguish between C-type lectins and galectins. Undesired side reactivities to galectins for C-type lectin drug delivery will thus be minimal.