Ultrasound／Microbubble Enhances Foreign Gene Expression in ECV304 Cells and Murine Myocardium

The success of gene therapy is largely dependent onthe development of vectors or vehicles that can selectivelyand efficiently deliver a therapeutic gene to cells or targetissues with minimal toxicity. Viruses are efficient transducing vectors. However, the safety concerns regardingthe use of virus vector in human make nonviral deliverysystem an attractive focus. Nonviral vectors are particularly suitable with respect to the simplicity of use, possibility of large-scale production and lack of s…     

Induction of Haploid Androgenesis in Pacific Oyster by UV Irradiation

Androgenesis, development from paternal but not maternal chromosomes, can be induced in some organisms including fish, but has not been induced previously in mollusk. In this study we investigated the induction of haploid androgenesis in the Pacific oyster by ultraviolet irradiation and observed nuclear behavior in the androgenetic eggs. Irradiation for 90 seconds at a UV intensity of 72 erg/mm² per second (6480 erg/mm²) was the optimal dose to achieve haploid androgenesis. The fertilization and development rates of D-shaped larvae decreased with increasing exposure time, and the development of the genetically inactivated eggs terminated before reaching the D-shaped stage. Cytologic observations showed that UV irradiation did not affect germinal vesicle breakdown or chromosomal condensation but caused various nuclear behavioral patterns during meiosis and first mitosis: 21.7% of eggs extruded all maternal chromosomes as 2 or 3 polar bodies, and 59.1% of eggs formed one female pronucleus. The maternally derived nucleus did not participate, or partially participated, in the first karyokinesis. The cytologic evidence demonstrates that the male genome is directing development in haploids produced by UV irradiation.     

SCOPmap: Automated assignment of protein structures to evolutionary superfamilies

Background  

Inference of remote homology between proteins is very challenging and remains a prerogative of an expert. Thus a significant drawback to the use of evolutionary-based protein structure classifications is the difficulty in assigning new proteins to unique positions in the classification scheme with automatic methods. To address this issue, we have developed an algorithm to map protein domains to an existing structural classification scheme and have applied it to the SCOP database.     

Linckosides C-E, three new neuritogenic steroid glycosides from the Okinawan starfish Linckia laevigata

Three new steroid glycosides, linckosides C-E, were isolated from the Okinawan starfish Linckia laevigata. Their structures and partial stereochemistry were elucidated by spectroscopic methods and chemical derivatization. These metabolites are additional members of the linckosides that were previously discovered as a novel class of neuritogenic compounds. Each of them possesses two monosaccharide units at C-3 of a polyhydroxylated steroidal aglycon and at the side chain (C-28 or C-29). Linckosides C and D are the first steroids that possess a hydroxyisopropyl substituent at C-24 of the side chain. These compounds are not only potent inducers of neurite outgrowth on PC12 cells but also significant enhancers of nerve growth factor (NGF) to induce the neurite outgrowth. The structure-activity relationships within the linckosides revealed that the presence of xylopyranose at the side chain was important rather than arabinofuranose, but that the diversity of the side chain carbon skeleton was not.     

Analysis of part of the<Emphasis Type="Italic">Trichophyton rubrum</Emphasis> ESTs

Trichophyton rubrum (T. rubrum) is the most common of the superficial fungi. In an effort to better understand the genetic and biochemical makeup ofT. rubrum, we generated cDNA libraries from 3 growth stages and used these to isolate 4002 unique expressed sequence tags (ESTs). Sequence comparisons with the Genbank database allowed 1226 of the ESTs to be assigned putative functions or matched with homologs from other organisms. Of the remaining ESTs, 989 were only weakly similar to known sequences and 1787 had no identifiable functions, suggesting that they represent novel genes. We further analyzed the presence of several important genes involved in the growth, metabolism, signal transduction, pathogenesis and drug resistance inT. rubrum. This information was used to newly elucidate important metabolic pathways inT. rubrum. Taken together, our results should form the molecular basis for continued research on the physiological processes and pathogenic mechanisms ofT. rubrum, and may lead to a better understanding of fungal drug resistance and identification of new drug targets.     

α<Subscript>1A</Subscript>- adrenergic receptor mediated pressor response to phenylephrine in anesthetized rat

To determine which subtype of α_1-adrenergic receptors plays a role in the regulation of blood pressure, with α_1--adrenergic receptor-mediated vasoconstriction in perfused hindlimb as a control, we compared the inhibitory effects of various aradrenergic receptor selective antagonists on the vasopressure responses to phenylephrine between the mean arterial pressure and hindlimb perfusion pressure in anesthetized rats. In Normotensive Wistar rats, the results showed that the inhibitory effects (dose ratios of ED₅₀, Dr) of α_-1adrenoceptor selective antagonist (prazosin, Dr 13.5 ± 3.6 vs. 15.1 ± 4.3, n = 11), /ga_1A-adrenoceptor selective antagonist (5-methyl-urapidil, Dr 2.4 ± 0.9 vs. 3.7 ± 2.3, n = 12; RS-17053, Dr 3.2 ± 1.6 vs. 4.4 ± 3.3, n =12) and α_1D- adrenoceptor selective antagonist (BMY7378, Dr 1.9 ±0.9 vs. 2.2 ± 0.8, n = 8) on phenylephrineinduced increases of perfusion pressure in the autoperfused femoral beds were the same as that in the mean arterial blood pressure in normotensive Wistar rats. The inhibitory effects of antagonists (RS-17053, Dr 3.4 ± 0.6 vs. 4.3 ± 0.9, n = 5; BMY7378, Dr 1.7 ± 0.5 vs. 1.7 ± 0.5, n = 8) in spontaneous hypertensive rats were similar with the Wistar rats. These results suggest that the mean arterial pressure induced by phenylephrine was mainly mediated by α_1A-adrenergic receptor in both the anesthetized Wistar rats and spontaneous hypertensive rats.     

Megator, an essential coiled-coil protein that localizes to the putative spindle matrix during mitosis in Drosophila

We have used immunocytochemistry and cross-immunoprecipitation analysis to demonstrate that Megator (Bx34 antigen), a Tpr ortholog in Drosophila with an extended coiled-coil domain, colocalizes with the putative spindle matrix proteins Skeletor and Chromator during mitosis. Analysis of P-element mutations in the Megator locus showed that Megator is an essential protein. During interphase Megator is localized to the nuclear rim and occupies the intranuclear space surrounding the chromosomes. However, during mitosis Megator reorganizes and aligns together with Skeletor and Chromator into a fusiform spindle structure. The Megator metaphase spindle persists in the absence of microtubule spindles, strongly implying that the existence of the Megator-defined spindle does not require polymerized microtubules. Deletion construct analysis in S2 cells indicates that the COOH-terminal part of Megator without the coiled-coil region was sufficient for both nuclear as well as spindle localization. In contrast, the NH2-terminal coiled-coil region remains in the cytoplasm; however, we show that it is capable of assembling into spherical structures. On the basis of these findings we propose that the COOH-terminal domain of Megator functions as a targeting and localization domain, whereas the NH2-terminal domain is responsible for forming polymers that may serve as a structural basis for the putative spindle matrix complex.     

Adiponectin acts in the brain to decrease body weight

Adiponectin (ADP) is an adipocyte hormone involved in glucose and lipid metabolism. We detected a rise in ADP in cerebrospinal fluid after intravenous (i.v.) injection, consistent with brain transport. In contrast to leptin, intracerebroventricular (i.c.v.) administration of ADP decreased body weight mainly by stimulating energy expenditure. Full-length ADP, mutant ADP with Cys39 replaced with serine, and globular ADP were effective, whereas the collagenous tail fragment was not. Lep(ob/ob) mice were especially sensitive to i.c.v. and systemic ADP, which resulted in increased thermogenesis, weight loss and reduction in serum glucose and lipid levels. ADP also potentiated the effect of leptin on thermogenesis and lipid levels. While both hormones increased expression of hypothalamic corticotropin-releasing hormone (CRH), ADP had no substantial effect on other neuropeptide targets of leptin. In addition, ADP induced distinct Fos immunoreactivity. Agouti (A(y)/a) mice did not respond to ADP or leptin, indicating the melanocortin pathway may be a common target. These results show that ADP has unique central effects on energy homeostasis.