The effects of Eleutherococcus senticosus and Panax ginseng on steroidal hormone indices of stress and lymphocyte subset numbers in endurance athletes.

A clinical trial was undertaken to investigate the effects of Eleutherococcus senticosus (ES) and Panax ginseng (PG) on competitive club-level endurance athletes engaged in their normal in-season training. Participants were matched for training stress and received a 33% ethanolic extract (8 mL/day) containing either ES, PG (equivalent to 4 g and 2 g/day of dried root, respectively), or a placebo. A pre-test and post-test were used to evaluate the effects of six weeks of supplementation on cortisol, testosterone, and testosterone to cortisol ratio (TCR) as well as circulating numbers of total T-cells, T-helper cells (CD4), T-suppressor cells (CD8), CD4 to CD8 ratio, natural killer cells, and B lymphocytes. None of the immune system variables changed significantly nor showed any clear trend from pre to post test in any of the treatment groups. No significant change in testosterone, cortisol or TCR was observed in the PG group. In the ES group, however, TCR decreased by 28.7% from 0.0464 to 0.0331 (P=0.03). The main contribution to this decrease appeared to be a non-significant (P= 0.07) 31% trend towards increased cortisol rather than a very small non-significant (P = 0.36) 7% decrease in the calculated mean for testosterone. This result suggested that contrary to initial expectation, ES increased rather than decreased hormonal indices of stress, which may be consistent with animal research suggesting a threshold of stress below which ES increases the stress response and above which ES decreases the stress response.     

(dC-dA)n.(dG-dT)n sequences have evolutionarily conserved chromosomal locations in Drosophila with implications for roles in chromosome structure and function.

In situ hybridization of (dC-dA)n.(dG-dT)n to the polytene chromosomes of Drosophila melanogaster reveals a clearly non-random distribution of chromosomal sites for this sequence. Sites are distributed over most euchromatic regions but the density of sites along the X chromosome is significantly higher than the density over the autosomes. All autosomes show approximately equal levels of hybridization except chromosome 4 which has no detectable stretches of (dC-dA)n.(dG-dT)n. Another striking feature is the lack of hybridization of the beta-heterochromatin of the chromocenter. The specific sites are conserved between different strains of D. melanogaster. The same overall chromosomal pattern of hybridization is seen for the other Drosophila species studied, including D. simulans, a sibling species with a much lower content of middle repetitive DNA, and D. virilis, a distantly related species. The evolutionary conservation of the distribution of (dC-dA)n.(dG-dT)n suggests that these sequences are of functional importance. The distribution patterns seen for D. pseudoobscura and D. miranda raise interesting speculations about function. In these species a chromosome equivalent to an autosomal arm of D. melanogaster has been translocated onto the X chromosome and acquired dosage compensation. In each species the new arm of the X also has a higher density of (dC-dA)n.(dG-dT)n similar to that seen on other X chromosomes. In addition to correlations with dosage compensation, the depletion of (dC-dA)n.(dG-dT)n in beta-heterochromatin and chromosome 4 may also be related to the fact that these regions do not normally undergo meiotic recombination.     

The leukotriene B4 paradox: neutrophils can, but will not, respond to ligand-receptor interactions by forming leukotriene B4 or its omega-metabolites.

Leukotriene B4 (5S,12R-dihydroxy-6,14-cis,8,10-trans-eicosatetraenoic acid, LTB4) is released from neutrophils exposed to calcium ionophores. To determine whether LTB4 might be produced by ligand-receptor interactions at the plasmalemma, we treated human neutrophils with serum-treated zymosan (STZ), heat-aggregated IgG and fMet-Leu-Phe (fMLP), agonists at the C3b, Fc and fMLP receptors respectively. STZ (10 mg/ml) provoked the formation of barely detectable amounts of LTB4 (0.74 ng/10(7) cells); no omega-oxidized metabolites of LTB4 were found. Adding 10 microM-arachidonate did not significantly increase production of LTB4 or its metabolites. Addition of 50 microM-arachidonate (an amount which activates protein kinase C) before STZ caused a 40-fold increase in the quantity of LTB4 and its omega-oxidation products. Neither phorbol myristate acetate (PMA, 200 ng/ml) nor linoleic acid (50 microM), also activators of protein kinase C, augmented generation of LTB4 by cells stimulated with STZ. Neither fMLP (10(-6) M) nor aggregated IgG (0.3 mg/ml) induced LTB4 formation (less than 0.01 ng/10(7) cells). Moreover, cells exposed to STZ, fMLP, or IgG did not form all-trans-LTB4 or 5-hydroxyeicosatetraenoic acid; their failure to make LTB4 was therefore due to inactivity of neutrophil 5-lipoxygenase. However, adding 50 microM-arachidonate to neutrophil suspensions before fMLP or IgG triggered LTB4 production, the majority of which was metabolized to its omega-oxidized products (fMLP, 20.2 ng/10(7) cells; IgG, 17.1 ng/10(7) cells). The data show that neutrophils exposed to agonists at defined cell-surface receptors produce significant quantities of LTB4 only when treated with non-physiological concentrations of arachidonate.     

Regional mapping panel for human chromosome 17: Application to neurofibromatosis type 1

A somatic cell hybrid mapping panel was constructed to localize cloned DNA sequences to any of 15 potentially different regions of human chromosome 17. Relatively high-resolution mapping is possible for 50% of the chromosome length in which 12 breakpoints are distributed over approximately 45 megabases, with an average spacing estimated at 1 breakpoint every 2-7 megabases. This high-resolution capability includes the pericentromeric region of 17 to which von Recklinghausen neurofibromatosis (NF1) has recently been mapped. Using 20 cloned genes and anonymous probes, we have tested the expected order and location of panel breakpoints and confirmed, refined, or corrected the regional assignment of several cloned genes and anonymous probes. Four markers with varying degrees of linkage to NF1 have been physically localized and ordered by the panel: the loosely linked markers myosin heavy chain 2 (25 cM) to p12----13.105 and nerve growth factor receptor (14 cM) to q21.1----q23; the more closely linked pABL10-41 (D17S71, 5 cM) to p11.2; and the tightly linked pHHH202 (D17S33) to q11.2-q12. Thus, physical mapping of linked markers confirms a pericentromeric location of NF1 and, along with other data, suggests the most likely localization is proximal 17q.     

Precise localization of NF1 to 17q11.2 by balanced translocation.

A female patient is described with von Recklinghausen neurofibromatosis (NF1) in association with a balanced translocation between chromosome 17 and 22 [46,XX,t(17;22)(q11.2;q11.2)]. The breakpoint in chromosome 17 is cytogenetically identical to a previously reported case of NF1 associated with a 1;17 balanced translocation and suggests that the translocation events disrupt the NF1 gene. This precisely maps the NF1 gene to 17q11.2 and provides a physical reference point for strategies to clone the breakpoint and therefore the NF1 gene. A human-mouse somatic cell hybrid was constructed from patient lymphoblasts which retained the derivative chromosome 22 (22pter----22q11.2::17q11.2----17qter) but not the derivative 17q or normal 17. Southern blot analysis with genes and anonymous probes known to be in proximal 17q showed ErbA1, ErbB2, and granulocyte colony-stimulating factor (CSF3) to be present in the hybrid and therefore distal to the breakpoint, while pHHH202 (D17S33) and beta crystallin (CRYB1) were absent in the hybrid and therefore proximal to the breakpoint. The gene cluster including ErbA1 is known to be flanked by the constitutional 15;17 translocation breakpoint in hybrid SP3 and by the acute promyelocytic leukemia (APL) breakpoint, which provides the following gene and breakpoint order: cen-SP3-(D17S33,CRYB1)-NF1-(CSF3,ERBA1, ERBB2)-APL-tel. The flanking breakpoints of SP3 and API are therefore useful for rapidly localizing new markers to the neurofibromatosis critical region, while the breakpoints of the two translocation patients provide unique opportunities for reverse genetic strategies to clone the NF1 gene.     

Crystallization of a small fragment of an aminoacyl tRNA synthetase

Single crystals of an amino-terminal fragment of Escherichia coli alanine tRNA synthetase have been prepared by the vapor diffusion method. The fragment extends to amino acid residue 368 and catalyzes the synthesis of alanyl adenylate. The crystals grow in the presence of alanine as rhombic plates in space group P2(1)2(1)2(1) and with unit cell dimensions of a = 67.9 A, b = 98.5 A and c = 123.6 A (1 A = 0.1 nm). They diffract to better than 3 A resolution.     

Zuotin, a putative Z-DNA binding protein in Saccharomyces cerevisiae.

A putative Z-DNA binding protein, named zuotin, was purified from a yeast nuclear extract by means of a Z-DNA binding assay using [32P]poly(dG-m5dC) and [32P]oligo(dG-Br5dC)22 in the presence of B-DNA competitor. Poly(dG-Br5dC) in the Z-form competed well for the binding of a zuotin containing fraction, but salmon sperm DNA, poly(dG-dC) and poly(dA-dT) were not effective. Negatively supercoiled plasmid pUC19 did not compete, whereas an otherwise identical plasmid pUC19(CG), which contained a (dG-dC)7 segment in the Z-form was an excellent competitor. A Southwestern blot using [32P]poly(dG-m5dC) as a probe in the presence of MgCl2 identified a protein having a molecular weight of 51 kDa. The 51 kDa zuotin was partially sequenced at the N-terminal and the gene, ZUO1, was cloned, sequenced and expressed in Escherichia coli; the expressed zuotin showed similar Z-DNA binding activity, but with lower affinity than zuotin that had been partially purified from yeast. Zuotin was deduced to have a number of potential phosphorylation sites including two CDC28 (homologous to the human and Schizosaccharomyces pombe cdc2) phosphorylation sites. The hexapeptide motif KYHPDK was found in zuotin as well as in several yeast proteins, DnaJ of E.coli, csp29 and csp32 proteins of Drosophila and the small t and large T antigens of the polyoma virus. A 60 amino acid segment of zuotin has similarity to several histone H1 sequences. Disruption of ZUO1 in yeast resulted in a slow growth phenotype.