Test-retest reliability of Patrick's hip range of motion test in healthy college-aged men

This study determined the test-retest reliability of Patrick's test as a hip range of motion assessment method. Fifty healthy college-aged men (mean age = 20.0 years) were studied during 2 testing sessions separated by 24 hours. A single inexperienced tester performed all the measurements in this study. Before data collection, the tester participated in a 15-minute instructional session on how to perform Patrick's test. To determine the range of motion associated with Patrick's test, the tester passively flexed, abducted, and externally rotated the hip of the lower extremity that was to be tested while subjects were in a supine position, so that the lateral malleolus of the tested lower extremity rested just superior to their opposite extended knee. The vertical distance between a mark on the lateral border of the patella of the tested lower extremity and the treatment table was then measured. The results revealed that Patrick's test demonstrated high test-retest reliability (intraclass correlation coefficient = 0.93). The results of this study support the use of Patrick's test as being a reliable measure of general hip motion when used by an inexperienced tester who participated in a 15-minute instructional session on how to perform Patrick's test.     

A large-conductance anion channel of the Golgi complex

An acidic lumenal pH is vital for the proper posttranslational modifications and sorting of proteins and lipids from the Golgi complex. We characterized ion channels present in Golgi fractions that have been cleared of transiting proteins. A large conductance anion channel was observed in approximately 30% of successful channel incorporations into the planar lipid bilayer. The channel, GOLAC-2, has six levels (one closed and five open). The open states are each approximately 20% increments of the maximal, 325 pS conductance. The channel was approximately 6 times more selective for Cl(-) over K(+). Binomial analysis of percent occupancy for each conducting level supports the hypothesis of five independent conducting pathways. The conducting levels can coordinately gate because full openings and closings were often observed. Addition of 3 to 5 mM reduced glutathione to the cis chamber caused dose-dependent increases in single channel conductance, indicating that the channel may be regulated by the oxidation-reduction state of the cell. We propose that GOLAC-2 is a co-channel complex consisting of five identical pores that have a coordinated gating mechanism. GOALC-2 may function as a source of counter anions for the H(+)-ATPase and may be involved in regulating charge balance and membrane potential of the Golgi complex.     

Genomic affinities in Arachis section Arachis (Fabaceae): molecular and cytogenetic evidence

Section Arachis is the largest of nine sections in the genus Arachis and includes domesticated peanut, A. hypogaea L. Most species are diploids (x=10) with two tetraploids and a few aneuploids. Three genome types have been recognized in this section (A, B and D), but the genomes are not well characterized and relationships of several newly described species are uncertain. To clarify genomic relationships in section Arachis, cytogenetic information and molecular data from amplified fragment length polymorphism (AFLP) and the trnT-F plastid region were used to provide an additional insight into genome composition and species relationships. Cytogenetic information supports earlier observations on genome types of A. cruziana, A. herzogii, A. kempff-mercadoi and A. kuhlmannii but was inconclusive about the genome composition of A. benensis, A. hoehnei, A. ipaensis, A. palustris, A. praecox and A. williamsii. An AFLP dendrogram resolved species into four major clusters and showed A. hypogaea grouping closely with A. ipaensis and A. williamsii. Sequence data of the trnT-F region provided genome-specific information and showed for the first time that the B and D genomes are more closely related to each other than to the A genome. Integration of information from cytogenetics and biparentally and maternally inherited genomic regions show promise in understanding genome types and relationships in Arachis.     

Rapid changes in initiation-limited rates of protein synthesis in rat thymic lymphocytes correlate with energy charge.

Depriving rat thymocytes of energy-providing substrates for 2 hr results in a 75–80% drop in rates of protein synthesis and a shift of ribosomes from active polysomes to inactive monomers and dimers. Glucose prevents these changes or, when added to starved cells, rapidly reverses them. Restoration of protein synthesis is associated with reversal of the 7% decline in the adenylate energy charge seen in starved cells. The data is consistent with the hypothesis that glucose increases initiation in starved cells, probably via effects on the balance of adenine nucleotides. Data with other substrates support this concept. The inability of glucose to fully restore energy charge in the presence of glucocorticoids or rotenone correlates with the limitation of protein synthesis.     

Fibroblast growth factor-2 stimulates cell proliferation and decreases sexually dimorphic cell death in an avian song control nucleus

The neural system controlling song in birds has proven a useful model for investigating how neuronal growth and survival are regulated by sexual differentiation. The present study focused on one song control area, the robust nucleus of the archistriatum (RA), and explored how sex differences in the proliferation of putative glia cells in this region influence sexually dimorphic cell survival. In zebra finches (Poephila guttata), RA neuron death is much greater in young females than in males, resulting in marked sex differences in RA neuron number. An earlier study indicated that just prior to this sexually dimorphic neuron death the proliferation of putative glia cells within the RA is significantly lower in females than in males and remains so throughout the peak of neuron death. This suggests that sex differences in glia (or glia-derived molecules) might regulate neuron survival during sexual differentiation of the RA. To determine whether increased cell proliferation within the RA favors increased cell survival, we infused the potent glia mitogen fibroblast growth factor-2 (FGF-2) into the RA unilaterally in young females. We find that FGF-2 infusions increase RA cell proliferation and concurrently decrease the incidence of degenerating RA cells, results consistent with the hypothesis that glia exert neurotrophic effects on RA neurons during sexual differentiation. © 1998 John Wiley & Sons, Inc. J Neurobiol 37: 573–581, 1998     

Dexamethasone induces gelsolin synthesis and altered morphology in L929 cells

When L929 cells are exposed to 5 μg/ml dexamethasone, synthesis of a 90,000 M(r) polypeptide is induced within 12 h. Flattening of the cells begins at about this time and progresses to become quite prominent after 48 h of exposure. Two-dimensional PAGE and partial proteolytic fingerprints identify the 90,000 M(r) polypeptide as gelsolin, a Ca(++)-dependent inhibitor of actin polymerization. Thus, this system provides evidence that gelsolin may have a role in regulating cell shape in response to physiological agents such as glucocorticoids.