Effects of leptin on hypothalamic arcuate neurons in Wistar and Zucker rats: an in vitro study

Leptin, a product of the ob gene, decreases food intake and body weight in both Wistar and Zucker obese rats when administered centrally or peripherally. To examine whether these leptin effects might be mediated through a neuropeptide Y (NPY) signaling pathway in the medial part of the arcuate nucleus of the hypothalamus (vmARC), the effects of leptin on vmARC neurons in Wistar and Zucker obese rats were examined electrophysiologically using brain slice preparations. Bath application of leptin inhibited about 60% of the vmARC neurons recorded in slices from Wistar rats. Similar inhibitory effects of leptin on vmARC neurons were also observed under low-Ca2+, high-Mg2+ Ringer's solution. However, inhibitory effects were almost absent under Ringer's solution containing a protein kinase C inhibitor, chelerythrine chloride. In slices from Zucker obese rats, leptin inhibited only about 25% of the vmARC neurons recorded, and the proportion of neurons inhibited was significantly smaller for these rats than for Wistar rats. These results suggest that reductions in food intake and body weight induced by leptin in both Wistar and Zucker obese rats are partly mediated via inhibition of an NPY signaling pathway in the vmARC.     

Sculpting the cardiac outflow tract

The cardiac outflow tract is the site of anomalies that affect a substantial proportion of individuals with congenital heart defects. The morphogenesis of this site is complex, and requires coordinated development of many cell types and tissues. It is therefore not surprising that developmental mistakes arise here, and that the steps and mechanisms of morphogenesis are still controversial and poorly understood, despite advances in molecular techniques. Recent findings have provided new insight into mechanisms of outflow tract morphogenesis, including clarification of its origins and the fate of cardiomyocytes, as well as invading cell populations. Application of new and old techniques and a wide range of approaches to tackle the unanswered questions about the outflow tract calls for collaboration among investigators from different disciplines including anatomists, physiologists, and molecular biologists.     

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.     

Community-level flowering phenology and fruit set: Comparative study of 25 woody species in a secondary forest in Japan

We investigated the flowering phenology, pollinator visitation, and fruit set of 25 animal-pollinated woody species in a warm temperate secondary forest in Japan. Various species flowered sequentially from February to October. The principal pollinators were bumblebees, honey-bees, flies and/or beetles and birds; bumblebees and flies/beetles pollinated most trees. The duration of flowering was shorter for species that bloomed in the middle of the season than it was for species that bloomed earlier or later in the season. The timing of flowering was more synchronous within species that had a shorter flowering duration; this was also detected when phylogenetically independent contrasts were calculated. This could be important for the effective pollination of species with a short flowering duration because such species bloom sequentially over a short period of less than 1month around May. Fruit set was related not to pollinator type, sex expression, flowering sequence (in order of the date of peak flowering) or flowering duration, but to the relative abundance of the species in the forest. This correlation was detected for fly- and beetle-pollinated species but not for bumblebee-pollinated species. Thus, relatively rare plant species with opportunistic pollinators might experience limited fruit set because of insufficient pollinator services. Bagging experiments conducted on eight hermaphrodite species revealed that the fruit set of bagged flowers was nearly zero, lower than that of control flowers. These results indicate the importance of pollinators for successful reproduction and thus for the coexistence of plants in this secondary forest.     

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.     

Peptide mapping and assessment of cryoprotective activity of 26/27-kDa dehydrin from soybean seeds

To characterize the molecular weight diversity of seed dehydrin among soybean cultivars, 26/27-kDa soybean dehydrins were purified and compared in peptide mapping patterns, partial amino acid sequences, and cryoprotective activity on enzyme. In reverse phase chromatograms of their trypsin digests, we detected several distinctive peaks, one of which was attributed to a part of the internal glycine-rich region. Partial amino acid sequences of peptide fragments from trypsin and S. aureus V8 protease cleavage were found to be identical to the Mat9 translation. The CP50 of purified 26/27-kDa dehydrins were estimated to be 0.30 and 0.11 microM, respectively.     

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.     

Macrolide antibiotics inhibit prostaglandin E2 synthesis and mRNA expression of prostaglandin synthetic enzymes in human leukocytes

We investigated the action of macrolide antibiotics, which are considered to have anti-inflammatory activity, on lipopolysaccharide (LPS)-stimulated prostaglandin (PG) E2 synthesis and the expression of mRNAs for cytosolic phospholipase A2 (cPLA2), cyclooxygenase (COX)-1, and COX-2 in human leukocytes. The production of LPS-stimulated PGE2 was significantly increased in peripheral polymorphonuclear leukocytes (PMNLs) and in mononuclear leukocytes (MNLs). Amounts of mRNAs for COX-2 and cPLA2, but not for COX-1, were enhanced by LPS in PMNLs and MNLs. The LPS-enhanced PGE2 synthesis and the expression of cPLA2 and COX-2 mRNAs were inhibited by clarithromycin, azithromycin and dexamethasone in PMNLs and MNLs. The mRNA expression of COX-1 in PMNLs was decreased by clarithromycin and azithromycin. Macrolide antibiotics inhibited PGE2 synthesis in human leukocytes by suppressing cPLA2, COX-1, and COX-2 mRNA expression. These data indicate one mechanism of macrolide anti-inflammatory activity.     

Effectiveness of Trivalent Inactivated Influenza Vaccine in Children Estimated by a Test-Negative Case-Control Design Study Based on Influenza Rapid Diagnostic Test Results

We assessed vaccine effectiveness (VE) against medically attended, laboratory-confirmed influenza in children 6 months to 15 years of age in 22 hospitals in Japan during the 2013–14 season. Our study was conducted according to a test-negative case-control design based on influenza rapid diagnostic test (IRDT) results. Outpatients who came to our clinics with a fever of 38°C or over and had undergone an IRDT were enrolled in this study. Patients with positive IRDT results were recorded as cases, and patients with negative results were recorded as controls. Between November 2013 and March 2014, a total of 4727 pediatric patients (6 months to 15 years of age) were enrolled: 876 were positive for influenza A, 66 for A(H1N1)pdm09 and in the other 810 the subtype was unknown; 1405 were positive for influenza B; and 2445 were negative for influenza. Overall VE was 46% (95% confidence interval [CI], 39–52). Adjusted VE against influenza A, influenza A(H1N1)pdm09, and influenza B was 63% (95% CI, 56–69), 77% (95% CI, 59–87), and 26% (95% CI, 14–36), respectively. Influenza vaccine was not effective against either influenza A or influenza B in infants 6 to 11 months of age. Two doses of influenza vaccine provided better protection against influenza A infection than a single dose did. VE against hospitalization influenza A infection was 76%. Influenza vaccine was effective against influenza A, especially against influenza A(H1N1)pdm09, but was much less effective against influenza B.