Age and growth of Lestrolepis japonica (Aulopiformes: Paralepididae) in Kagoshima Bay,southern Japan

 Age and growth of a paralepidid, Lestrolepis japonica, were determined from sagittal otoliths of specimens collected from April 2001 to February 2002 in Kagoshima Bay, southern Japan. Marginal growth increments indicated that the annulus was formed once a year, in August and September. Four groups were recognized, having none, one, two, or three annuli, respectively. Age in months was assigned to each individual on the basis of August as the birth month. The maximum recorded age was 48 months. Growth was expressed by von Bertalanffy's equation, L _t  = 171.91{1 − exp[−0.148(t + 0.403)]}, t being the age in months and L _t the standard length (mm) at age t. Received: July 15, 2002 / Revised: November 18, 2002 / Accepted: December 10, 2002     

Extracellular phycoerythrin-like protein released by freshwater cyanobacteria <Emphasis Type="Italic">Oscillatoria</Emphasis> and <Emphasis Type="Italic">Scytonema</Emphasis> sp.

During growth of the freshwater cyanobacteria, Oscillatoria sp. BTCC/A0004, and Scytonema sp. TISTR 8208, a pink pigment is released into the growth medium. The pigment from each source had a molecular weight of approximately 250 kDa and had adsorption maxima at 560 and 620 nm. These results suggest that pink pigment is a phycoerythrin-like protein. It inhibited the growth of green algae, Chlorella fusca and Chlamydomonas reinhardtii, but not other cyanobacteria or true bacteria. The concentration at which growth inhibition 50% occurred was 0.5, 6 and more than 10 mg ml⁻¹, respectively.     

Role of V3 independent domains on a dualtropic human immunodeficiency virus type 1 (HIV-1) envelope gp120 in CCR5 coreceptor utilization and viral infectivity

The molecular mechanism of human immunodeficiency virus type 1 (HIV-1) entry into cells involves specific interactions between the viral envelope glycoprotein gp120 and two target cell proteins, CD4 and either CCR5 or CXCR4 chemokine receptors. In order to delineate the functional role of HIV-1 gp120 subdomains of dualtropic strains in CCR5 coreceptor usage, we used a panel of chimeric viruses in which the V1/V2 and V3 domains of gp120 from the dualtropic HIV-1(KMT) isolate were introduced either alone or in combination into the T-tropic HIV-1(NL4-3) background. These chimeric constructs were employed in cell-cell fusion and cell-free virus infectivity assays using cell lines expressing CD4 and the CCR5 chemokine receptor. In both assays, the V3 domain of HIV-1(KMT) but not the V1/V2 domain proved to be the principal determinant of CCR5 coreceptor usage. However, in the cell-free viral infectivity assay although a chimeric virus with a combined V1/V2 and V3 domains of HIV-1(KMT) efficiently fused with coreceptor expressing cells, yet its infectivity was markedly diminished in CCR5 as well as CXCR4 expressing cells. Restoring a comparable level of infection of such chimeric virus required the C3-V5 domain from HIV-1(KMT) to be introduced. Our present findings confirmed that the V3 domain is the major determinant of fusion activity and cellular tropism, and demonstrated a dispensable role for the V1/V2 domain. In addition the C3-V5 domain appeared to play an important role in viral infectivity when the corresponding V1/V2 and V3 domains are present.     

Everolimus prolonged survival in transgenic mice with EGFR-driven lung tumors

Everolimus is an orally administered mTOR inhibitor. The effect, and mechanism of action, of everolimus on lung cancers with an epidermal growth factor receptor (EGFR) mutation remain unclear. Four gefitinib-sensitive and -resistant cell lines were used in the present work. Growth inhibition was determined using the MTT assay. Transgenic mice carrying the EGFR L858R mutation were treated with everolimus (10 mg/kg/day), or vehicle alone, from 5 to 20 weeks of age, and were then sacrificed. To evaluate the efficacy of everolimus in prolonging survival, everolimus (10 mg/kg/day) or vehicle was administered from 5 weeks of age. The four cell lines were similarly sensitive to everolimus. Expression of phosphorylated (p) mTOR and pS6 were suppressed upon treatment with everolimus in vitro, whereas the pAKT level increased. The numbers of lung tumors with a long axis exceeding 1 mm in the everolimus-treated and control groups were 1.9±0.9 and 9.4±3.2 (t-test, p<0.001), respectively. pS6 was suppressed during everolimus treatment. Although apoptosis and autophagy were not induced in everolimus-treated EGFR transgenic mice, angiogenesis was suppressed. The median survival time in the everolimus-treated group (58.0 weeks) was significantly longer than that in the control group (31.2 weeks) (logrank test, p<0.001). These findings suggest that everolimus had an indirect effect on tumor formation by inhibiting angiogenesis and might be effective to treat lung tumors induced by an activating EGFR gene mutation.     

Expression of gustducin overlaps with that of type III IP3 receptor in taste buds of the rat soft palate

Type III IP3 receptor (IP3R3) is one of the common critical calcium-signaling molecules for sweet, umami, and bitter signal transduction in taste cells, and the total IP3R3-expressing cell population represents all cells mediating these taste modalities in the taste buds. Although gustducin, a taste cell-specific G-protein, is also involved in sweet, umami, and bitter signal transduction, the expression of gustducin is restricted to different subsets of IP3R3-expressing cells by location in the tongue. Based on the expression patterns of gustducin and taste receptors in the tongue, the function of gustducin has been implicated primarily in bitter taste in the circumvallate (CV) papillae and in sweet taste in the fungiform (FF) papillae. However, in the soft palate (SP), the expression pattern of gustducin remains unclear and little is known about its function. In the present paper, the expression patterns of gustducin and IP3R3 in taste buds of the SP and tongue papillae in the rat were examined by double-color whole-mount immunohistochemistry. Gustducin was expressed in almost all (96.7%) IP3R3-expressing cells in taste buds of the SP, whereas gustducin-positive cells were 42.4% and 60.1% of IP3R3-expressing cells in FF and CV, respectively. Our data suggest that gustducin is involved in signal transduction of all the tastes of sweet, umami, and bitter in the SP, in contrast to its limited function in the tongue.     

Effects of Systemic Administration of 1-Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine to Mice on Tyrosine Hydroxylase, l-3,4-Dihydroxyphenylalanine Decarboxylase, Dopamine β-Hydroxylase, and Monoamine Oxidase Activities in the Striatum and Hypothalamus

The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (30 mg/kg subcutaneously per day for 8 days) to C57BL/6N mice were studied on tyrosine hydroxylase (TH), L-3,4-dihydroxyphenylalanine decarboxylase (DDC), and monoamine oxidase (MAO) activities in the striatum, and TH, DDC, dopamine-beta-hydroxylase (DBH), and MAO activities in the hypothalamus. Treatment with MPTP led to a large decrease in TH activity and a parallel decrease in DDC activity in the striatum, as compared with the saline controls. In contrast, MPTP administration did not cause a decrease of the activities of TH, DDC, and DBH in the hypothalamus. There was also no reduction in MAO activities of striatum and hypothalamus. These data indicate that MPTP administration to mice results in specific degeneration of the dopaminergic nigrostriatal pathway and that DDC in the mouse striatum may mainly be localized in the dopaminergic neurons with TH.     

Microbial fucoidan degradation by Luteolibacter algae H18 with deacetylation

A bacterial strain that assimilates fucoidan from Cladosiphon okamuranus as sole carbon source was isolated as Luteolibacter algae H-18. It was found that it degraded fucoidan by intracellular enzymes, and that the degradation reactions were catalyzed by multiple enzymes. One enzyme, designated fraction B, was established to exhibit the deacetylation reaction of fucoidan. Other enzyme(s), designated fraction A, catalyzed the reaction(s) lowering the molecular weight of fucoidan.     

Characterization of Nocardithiocin Derivatives Produced by Amino Acid Substitution of Precursor Peptide notG

International Journal of Peptide Research and Therapeutics - Nocardithiocin is a thiopeptide compound produced by the pathogenic actinomycete Nocardia pseudobrasiliensis that displays activity...     

Emerging evidence for cell-autonomous axon guidance

Current models of axon guidance within the central nervous system (CNS) involve the presentation of environmental cues to navigating growth cones. The surrounding and target tissues present a variety of ligands that either restrict or promote growth, thus providing pathfinding instructions to developing axons. Recent findings show that RGMb, a GPI anchored extracellular protein present on retinal ganglion cells, down-regulates Wnt3a signaling by lowering LRP5 levels at the membrane surface. When RGMb is phosphorylated by the extracellular tyrosine kinase VLK, phosphorylated RGMb (p-RGMb) is internalized and carries LRP5 towards intracellular compartments. In the eye, a dorsal-high ventral-low gradient of VLK generates a dorsal-low ventral-high gradient of LRP5 that modulates Wnt3a signaling. These molecules, which are all expressed by individual RGCs, generate Wnt-signal gradients along the dorso-ventral axis of the retina, resulting in differential axon growth which in turn regulates proper retino-tectal/collicular map formation. This pathway represents a regulatory mechanism whereby extracellular phosphorylation generates what may be the first example of a unique self-guiding mechanism that affects neuronal-target connections independent of paracrine signals from the surrounding target tissue.