Behavioral responses of males to estradiol-treated females in the budgerigar (<Emphasis Type="Italic">Melopsittacus undulatus</Emphasis>)

We investigated the effects of estradiol-treated females on the behavior of male budgerigars. In comparison to control females, females given implants of estradiol showed elevated nest behavior and darker cere color, which are characteristics of breeding females. After we confirmed the efficacy of estradiol treatment on behavior and morphology, each female was paired with a male mate. Males paired with estradiol-treated females showed more courtship behavior (auditory and visual display, and courtship feeding) to their mates than males paired with control females. These data indicate that budgerigar females with a high estrogen level enhance males' courtship behavior. Since males did not show response to estradiol-treated females soon after females were introduced, effects of estradiol-treated female budgerigars may be mediated by the endocrine system, rather than wholly by the nervous system, of males. Electronic Publication     

The Large Isoform of Myelin-Associated Glycoprotein Is Scarcely Expressed in the Quaking Mouse Brain

Two polypeptide isoforms of myelin-associated glycoprotein (MAG) with molecular masses of 72 and 67 kDa are produced by alternative splicing of the exon 12 portion. Our previous work has demonstrated that in the quaking mouse brain this alternative splicing is lacking and that the mRNA coding the large MAG isoform (L-MAG) is scarcely expressed, whereas that of small MAG isoform (S-MAG) is overexpressed. In the present study, we prepared antisera specific to the S-MAG and L-MAG amino acid residues, respectively. Immunoblots showed that the L-MAG band was scarcely detectable in the quaking mouse brain, whereas the S-MAG band had an apparently higher molecular mass than in the normal control. Our immunohistochemical study also showed that L-MAG was scarcely stained in the quaking mouse brain. These results seemed to reflect a reduction in content of L-MAG mRNA and abnormal glycosylation in the quaking mouse brain.     

N-glycan structures of a recombinant mouse soluble Fcγ receptor II

N-glycans of a recombinant mouse soluble Fc receptor II (sFcRII) expressed in baby hamster kidney cells were released from glycopeptides by digestion with glycoamidase A (from sweet almond), and the reducing ends of the oligosaccharides were reductively aminated with 2-aminopyridine. The derivatized N-glycans were separated and structurally identified by a three-dimensional high-performance liquid chromatography (HPLC) mapping technique on three kinds of HPLC columns [Takahashi, et al. (1995) Anal. Biochem. 226: 139–46]. Eighteen different major N-glycan structures were identified, of which six were neutral (45%), five mono-sialyl (49%), one di-sialyl (4.6%), five tri-sialyl (1.1%), and one tetra-sialyl (0.3%). All N-glycan structures determined were complex type with fucosylation at the N-acetylglucosamine residue of the reducing end, and N-acetylneuraminic acid, when present, was -(2,3)-linked. The existence of a unique structure containing both N-acetylgalactosamine and -(2,3)-N-acetylneuraminic acid residues at the reducing ends, as below, was confirmed by MALDI-TOF mass spectrometry.     

Suppressors of temperature-sensitive mutations in a ribosomal protein gene, rpsL (S12), of Escherichia coli K12

Summary Temperature-sensitive (ts) mutations were isolated within a ribosomal protein gene (rpsL) of Escherichia coli K12. Mutations were mapped by complementation using various transducing phages and plasmids carrying the rpsL gene, having either a normal or a defective promoter for the rpsL operon. One of these mutations, ts118, resulted in a mutant S12 protein which behaved differently from the wild-type S12 on CM-cellulose column chromatography. Suppressors of these ts mutations were isolated and characterized; one was found to be a mutation of a nonribosomal protein gene which was closely linked to the RNAase III gene on the E. coli chromosome. This suppressor, which was recessive to its wild-type allele, was cloned into a transducing phage and mapped finely. A series of cold-sensitive mutations, affecting the assembly of ribosomes at 20°C, was isolated within the purL to nadB region of the E. coli chromosome and one group, named rbaA, mapped at the same locus as the suppressor mutation, showing close linkage to the RNAase III gene.     

Regulation of pathologic retinal angiogenesis in mice and inhibition of VEGF-VEGFR2 binding by soluble heparan sulfate

Development of the retinal vascular network is strictly confined within the neuronal retina, allowing the intraocular media to be optically transparent. However, in retinal ischemia, pro-angiogenic factors (including vascular endothelial growth factor-A, VEGF-A) induce aberrant guidance of retinal vessels into the vitreous. Here, we show that the soluble heparan sulfate level in murine intraocular fluid is high particularly during ocular development. When the eyes of young mice with retinal ischemia were treated with heparan sulfate-degrading enzyme, the subsequent aberrant angiogenesis was greatly enhanced compared to PBS-injected contralateral eyes; however, increased angiogenesis was completely antagonized by simultaneous injection of heparin. Intraocular injection of heparan sulfate or heparin alone in these eyes resulted in reduced neovascularization. In cell cultures, the porcine ocular fluid suppressed the dose-dependent proliferation of human umbilical vein endothelial cells (HUVECs) mediated by VEGF-A. Ocular fluid and heparin also inhibited the migration and tube formation by these cells. The binding of VEGF-A and HUVECs was reduced under a high concentration of heparin or ocular fluid compared to lower concentrations of heparin. In vitro assays demonstrated that the ocular fluid or soluble heparan sulfate or heparin inhibited the binding of VEGF-A and immobilized heparin or VEGF receptor 2 but not VEGF receptor 1. The recognition that the high concentration of soluble heparan sulfate in the ocular fluid allows it to serve as an endogenous inhibitor of aberrant retinal vascular growth provides a platform for modulating heparan sulfate/heparin levels to regulate angiogenesis.     

The heterogeneity of human fibroblasts as determined from the effects of hydrocortisone on cell growth and specific dexamethasone binding

To elucidate the heterogeneity of human fibroblasts from lung and skin, the effects of hydrocortisone on cell proliferation and the specific dexamethasone binding to cells were studied. Hydrocortisone at physiological concentrations stimulated the proliferation in three strains of human fetal lung fibroblasts and inhibited it in two strains. There are two kinds of fibroblasts in the human fetal lung in addition to the human skin fibroblasts reported previously. Dexamethasone-binding experiments showed that human fibroblasts may be classified into two groups with respect to the dissociation constant (Kd) of the binding reaction. The heterogeneity of human fibroblasts shown by Kd could not be correlated to classification on the basis of the effects of hydrocortisone on cell proliferation. The differences in Kd for the binding reactions suggest differences in donor tissues from which human fibroblasts are derived.     

Association between dental health behaviours, mental/physical function and self-feeding ability among the elderly: a cross-sectional survey

Objectives : The aim of this study was to determine the association between dental health behaviour, mental/physical function and self‐feeding ability among the elderly. Subjects : A total of 414 elderly dental patients aged 65 years and older participated in this study. Methods : A survey was carried out for three years and seven months starting in January 1998 at the Chubu National Hospital. The patients or their carers were examined/interviewed about the severity of senile dementia, dental health behaviour, ability to rinse their mouths, ability to manage dentures, and ability to sit at a table during meals. To assess the association with self‐feeding ability among the elderly, cut‐offs were given for these variables, and then the odds ratios were calculated. Results : The strongest association to self‐feeding ability was marked by inability to rinse their own mouth, followed by inability to manage dentures, inability to sit at a table during meals, severe senile dementia and less frequency of toothbrushing. Conclusion : Elderly who have lost the feeding ability often could not maintain their dental health by themselves. Carers must provide not only a feeding service with acknowledgement of aspiration but oral care to prevent dental disease and fatal pneumonia in the elderly.     

Heparan sulfate 6-o-sulfotransferase is essential for muscle development in zebrafish

Heparan sulfate proteoglycans function in development and disease. They consist of a core protein with attached heparan sulfate chains that are altered by a series of carbohydrate-modifying enzymes and sulfotransferases. Here, we report on the identification and characterization of a gene encoding zebrafish heparan sulfate 6-O-sulfotransferase (hs6st) that shows high homology to other heparan sulfate 6-O-sulfotransferases. When expressed as a fusion protein in cultured cells, the protein shows specific 6-O-sulfotransferase activity and preferentially acts on the iduronosyl N-sulfoglycosamine. In the developing embryo, hs6st is expressed in the brain, the somites, and the fins; the same structures that were affected upon morpholino-mediated functional knockdown. Morpholino injections significantly inhibited 6-O- but not 2-O-sulfation as assessed by HPLC. Morphants display disturbed somite specification independent of the somite oscillator mechanism and have impaired muscle differentiation. In conclusion, our results show that transfer of sulfate to specific positions on glycosaminoglycans is essential for muscle development.     

Differences in growth of transplantable ascites hepatoma among various lines of Donryu rat

A total of 48 Donryu rats from 8 colonies of 5 lines were inoculated intravenously with 10(7) cells of the ascites hepatoma strain AH 66. All the conventional rats of the lines D-1 and D-2 died between 9 and 15 days after inoculation with a good growth of implanted tumor cells. On the other hand, SPF rats of the lines A-1, B-1, C and E survived for 60 days showing complete rejection of the implanted tumor cells. A 50% of conventionalized ex-SPF rats of the lines A-2 and B-2, which had been once established as SPF colonies, and thereafter had been "re-conventionalized", rejected the tumor cells. The present observations indicate that the microbial conditions of the animal, e.g. whether the animal is SPF or not, might play an important role in the growth of the implanted ascites hepatoma.