The effect of liquid carbohydrate ingestion on repeated maximal effort exercise in competitive cyclists

We investigated the effects of carbohydrate ingestion during recovery from high-intensity exercise on subsequent high-intensity exercise in trained cyclists. Aerobic power was determined, and the competitive cyclists (N = 7) were familiarized with the 100-kJ test protocol (100 KJ-TEST). The subjects performed a first 100 KJ-TEST (RIDE-1), ingested 0.7 g.(kg body mass)(-1) of Gatorlode (CHO) or placebo (PLC), rested for 60 minutes, and then performed a second 100 KJ-TEST (RIDE-2). Blood samples taken before (PRE-1) and after (POST-1) RIDE-1 and before (PRE-2) and after (POST-2) RIDE-2 were analyzed for plasma glucose ([glucose]), lactate, and nonesterified fatty acids ([NEFA]). No significant differences (p > 0.05) were observed between treatments in time to complete RIDE-1 (CHO = 270.3 +/- 29.0 seconds; PLC = 269.9 +/- 33.0 seconds) and RIDE-2 (CHO = 271.7 +/- 26.6 seconds; PLC = 275.3 +/- 30.6 seconds). Plasma [glucose] significantly decreased during the 60-minute recovery for PLC. There was an interaction effect for [NEFA] during recovery, with [NEFA] increasing for PLC and decreasing for CHO. Carbohydrate ingestion after maximal exercise does not appear to influence subsequent short-duration maximal effort exercise in competitive cyclists but does alter plasma [glucose] and [NEFA] relative to a PLC condition.     

Lipid Raft targeting of the TC10 amino terminal domain is responsible for disruption of adipocyte cortical actin

Overexpression of the Rho family member TC10alpha, disrupts adipocyte cortical actin structure and inhibits insulin-stimulated GLUT4 translocation when targeted to lipid raft microdomains. This appears to be independent of effecter domain function because overexpression of the wild-type (TC10/WT), constitutively GTP-bound (TC10/Q75L), and constitutively GDP bound (TC10/T31N) all inhibit adipocyte cortical actin structure and GLUT4 translocation. To examine the structural determinants responsible for these effects, we generated a series of chimera proteins between TC10 with that of H-Ras and K-Ras. Chimera containing the 79 (TC10-79/H-Ras), 41 (TC10-41/H-Ras), or 16 (TC10-16/H-Ras) amino acids of the TC10 amino terminal extension fused to H-Ras disrupted cortical actin and inhibited insulin-stimulated GLUT4 translocation. In contrast, the same amino terminal TC10 extensions fused to K-Ras had no significant effect on either GLUT4 translocation or cortical actin structure. Similarly, expression of TC10beta was without effect, whereas fusion of the amino terminal 8 amino acid of TC10alpha onto TC10beta resulted in an inhibition of insulin-stimulated GLUT4 translocation. Within the amino terminal extension point mutation analysis demonstrated that both a GAG and GPG sequences when lipid raft targeted was essential for these effects. Furthermore, expression of the amino terminal TC10 deletions DeltaNT-TC10/WT or DeltaNT-TC10/T31N had no detectable effect on cortical actin organization and did not perturb insulin-stimulated GLUT4 translocation. Surprisingly, however, expression of DeltaNT-TC10/Q75L remained fully capable of inhibiting insulin-stimulated GLUT4 translocation without affecting cortical actin. These data demonstrate that inhibitory effect of TC10 overexpression on adipocyte cortical actin organization is due to the specific lipid raft targeting of the unusual TC10 amino terminal extension.     

Platyamoeba nucleolilateralis n. sp. from the Chesapeake Bay Region

Members of the genus Platyamoeba are among the most common of the free-living brackish and marine amoebae; yet, to date only twelve species have been documented in the literature and only a limited number of habitats have been sampled globally. During the course of a systematic survey of salt-marsh amoebae along the east coast of the United States, a new species of Platyamoeba was discovered in sediment samples obtained from a salt marsh at Assateague Island, VA. The species can be distinguished from all other described species within the genus by the presence of a nucleus with a single parietal nucleolus and a floating form with long tapering pseudopods. Its shape varies from flabellate to spatulate as described for species of Platyamoeba and Vannella. The fine structure of the glycocalyx, however, is characteristic of Platyamoeba.     

The history of surface electromyography

The history of muscle pain and dysfunction is viewed through the lens of a four factor theory of histologic (tissue related) issues, psychologic (emotional) issues, sensory motor (movement) issues, and biomechanical (postural) issues. The historical antecedents of surface electromyography are reviewed.     

Haplotype blocks and linkage disequilibrium in the human genome

There is great interest in the patterns and extent of linkage disequilibrium (LD) in humans and other species. Characterizing LD is of central importance for gene-mapping studies and can provide insights into the biology of recombination and human demographic history. Here, we review recent developments in this field, including the recently proposed 'haplotype-block' model of LD. We describe some of the recent data in detail and compare the observed patterns to those seen in simulations.