Isolation and identification of lateral bud growth inhibitor,indole-3-aldehyde,involved in apical dominance of pea seedlings

A lateral bud growth inhibitor was isolated from etiolated pea seedlings and identified as indole-3-aldehyde. The indole-3-aldehyde content was significantly higher in the diffusates from explants with apical bud and indole-3-acetic acid treated decapitated explants, in which apical dominance is maintained, than in those from decapitated ones releasing apical dominance. When the indole-3-aldehyde was applied to the cut surface of etiolated decapitated plants or directly to the lateral buds, it inhibited outgrowth of the latter. These results suggest that indole-3-aldehyde plays an important role as a lateral bud growth inhibitor in apical dominance of pea seedlings.     

Increased binding and chemotactic capacities of PDGF-BB on fibroblasts in radiation pneumonitis

Although pulmonary fibrosis is a frequent and serious consequence of radiotherapy for thoracic malignant diseases such as lung cancer, the pathogenesis of this radiation-induced lung disorder remains unclear. To clarify the mechanisms underlying radiation pneumonitis and pulmonary fibrosis, we investigated the expression of platelet-derived growth factor receptor (PDGFR) on fibroblasts obtained from irradiated rat lungs and on control fibroblasts. Whole lungs of male Wistar rats were irradiated with a single dose of 15 Gy, and lung fibroblasts were isolated at 4 weeks after the irradiation. The chemotactic response of irradiated lung fibroblasts to PDGF-BB was significantly higher than that of control lung fibroblasts, whereas there was no significant difference between irradiated lung fibroblasts and control lung fibroblasts in the response to PDGF-AA. Receptor binding assay showed more specific binding sites for PDGF-BB on irradiated lung fibroblasts than on control lung fibroblasts, and the displacement of (125)I-labeled PDGF binding to fibroblasts by unlabeled PDGF showed that (125)I-labeled PDGF-BB was displaced by PDGF-BB but not by PDGF-AA. These results suggest that the increased binding sites for PDGF-BB on irradiated lung fibroblasts correspond mainly to PDGFRB. Scatchard analysis of the saturation data demonstrated an approximately twofold increase both in the number of PDGF-BB binding sites and in the binding affinity in irradiated lung fibroblasts compared to that in control lung fibroblasts. Those results suggest that the increased chemotactic response of irradiated lung fibroblasts to PDGF-BB is related to the overexpression of PDGFRB, which may have an important role in the pathogenesis of radiation-induced pneumonitis and pulmonary fibrosis.     

The spindle pole body of the pathogenic yeast Exophiala dermatitidis: variation in morphology and positional relationship to the nucleolus and the bud in interphase cells

The spindle pole body (SPB) in the interphase cell of the pathogenic yeast Exophiala dermatitidis was studied in detail. The SPB was located on the outer nuclear envelope and was 342 +/- 86 nm long in a haploid strain. It consisted of two disk elements that measured 151 +/- 43 nm in diameter and 103 +/- 17 nm in thickness, connected by a rod-shaped midpiece that measured 56 +/- 20 nm in length and 37 +/- 9 nm in diameter. There were considerable variations in size and morphology of interphase SPB. Some disk elements appeared spherical but others were more flattened, and there was variation in electron density. A few SPBs did not have the midpiece. The SPB of a diploid strain was 486 +/- 118 nm long, thus significantly bigger than that of the haploid strain. The SPB tended to be localized away from the nucleolus (110 +/- 48 degrees), but close to the bud (78 +/- 45 degrees). The present study highlights the necessity of observing a large number of micrographs in three-dimensions to describe accurately the ultrastructure of the SPB in yeast.     

Effects of dietary vitamin E and selenium on arginase activity in the liver, kidneys, and heart of rats treated with high doses of glucocorticoid

The effects of dietary intake of vitamin E and selenium on arginase activity in the liver, kidneys, and heart of rats treated with high doses of prednisolone were investigated. Rats were divided into five groups. Groups 3, 4, and 5 received a daily supplement in their drinking water of vitamin E, Se, and a combination of vitamin E and Se, respectively, for 30 days. For 3 days subsequently, the control group (group 1) was given a placebo, and the remaining four groups were injected intramuscularly with prednisolone. The tissue samples were collected from each group at 4, 8, 12, 24, and 48 h after the last administration of prednisolone. In the group treated with prednisolone alone, arginase activity in the liver was found to have increased at all the time periods, whereas it had decreased significantly in the heart at 48 h. Arginase activity in the kidneys was not affected by prednisolone. Compared to the control and prednisolone groups, arginase activity in the kidneys and heart of the vitamin E- and Se-supplemented groups was found to be significantly increased at all time periods, however, no difference was seen in the combination group. Arginase activity in the liver of the vitamin E-supplemented group was found to have decreased at all time periods, however, in the Se group compared to the prednisolone group it had reduced at 24 and 48 h only. In the combination group compared to the prednisolone group, liver arginase activity increased constantly up to 12 h returning to normal values at 48 h. Vitamin E and Se in combination may prevent the changes in arginase activity in various tissues caused by prednisolone.     

Polyphenols from some foodstuffs as inhibitors of ovalbumin permeation through caco-2 cell monolayers

Some spices showed high inhibitory activity against ovalbumin permeation through Caco-2 cell monolayers. Pimentol from allspice, rosmarinic acid and luteolin-7-O-beta-glucuronide from thyme, quercetin-3-O-beta-glucuronide from coriander and rutin from tarragon were identified as the active principles. A structure-activity relationship study among the active isolates and their related compounds indicated that the presence of a catechol structure played an important role in the inhibitory activity of each compound.     

N-cyanomethyl-2-chloroisonicotinamide induces systemic acquired resistance in arabidopsis without salicylic acid accumulation

Systemic acquired resistance (SAR) is a potent innate immunity system in plants that is induced through the salicylic acid-mediated pathway. N-cyanomethyl-2-chloroisonicotinamide (NCI) is able to induce a broad range of disease resistance in tobacco and rice and induces SAR marker gene expression without SA accumulation in tobacco. To clarify the detailed mode of action of NCI, we analyzed its ability to induce defense gene expression and resistance in Arabidopsis mutants that are defective in various defense signaling pathways. Wild-type Arabidopsis treated with NCI exhibited increased expression of several pathogenesis-related genes and enhanced resistance to the bacterial pathogen, Pseudomonas syringae pv. tomato DC3000. NCI induced disease resistance and PR gene expression in NahG transgenic plants, but not in the npr1 mutant. NCI could induce PR gene expression in the etr1-1, ein2-1 and jar1-1 mutants. Thus, NCI activates SAR, independently from ethylene and jasmonic acid, by stimulating the site between SA and NPR1.     

HMB-45 staining for cytology of primary melanoma of the vagina. A case report

BACKGROUND: Malignant melanoma in the vagina is very rare, but its diagnosis is usually easy if a melanin pigment is present. With cytodiagnosis, however, it is difficult to differentiate amelanotic melanoma or scantily pigmented melanoma from other conditions. In the present case, monoclonal antibody HMB-45, the efficacy of which has been established in histologic studies, was used in the cytodiagnosis of amelanotic melanoma in the vagina. CASE: A woman, aged 78 years, presented with a brownish, nodular tumor, diameter 3 cm, in the vagina. Scraping smears with Papanicolaou staining showed nonepithelial malignant cells without granules suggesting melanin. Smears stained with HMB-45 showed positive immunoreactivity. The diagnosis underwent histologic confirmation of amelanotic melanoma on the initial biopsy. CONCLUSION: Cytodiagnosis was made with HMB-45, which proved very effective in the differential cytodiagnosis of amelanotic melanoma and scantily pigmented melanoma, particularly because it obviated the need for tissue invasion.