Interaction of calmodulin and ophiobolin A, a fungal phytotoxin

Ophiobolin A, a fungal phytotoxin which can stimulate the net leakage of electrolytes and glucose from maize seedling roots, is a potent inhibitor of calmodulin. The inhibition at pH 7.0 is time-dependent and could not be reversed by dialysis, dilution, nor denaturation, and was more pronounced in the presence than in the absence of Ca(\u272+). The direct interaction between ophiobolin A and calmodulin is shown by the quenching of the intrinsic tyrosine fluorescence of bovine brain calmodulin upon the addition of ophiobolin A. Maize calmodulin, reacted with ophiobolin A, has a smaller electrophoretic mobility than untreated calmodulin. Ophiobolin A reacts with primary amino groups to give conjugated enamine products with (lamda)max from 270-285 nm. With the (epsilon)-amino group of N-(alpha)-acetyl-L-lysine, the (lamda)max is 272 nm. The same (lamda)max is also observed when bovine brain calmodulin reacts with ophiobolin A. The above suggests that ophiobolin A reacts with the (epsilon)-amino group of lysine residues in calmodulin to form a conjugated enamine product. By using UV measurements, one calmodulin molecule reacts with two molecules of ophiobolin A. The reaction with one molecule of ophiobolin A, however, completely inhibits the calmodulin. Calmodulin treated with ophiobolin A is resistant to tryptic cleavage at lysine 77. Dictyostelium discoideum calmodulin, which has glutamine instead of lysine at residue 77, is inhibited equally by ophiobolin A in the phosphodiesterase assay. Thus apparently, lysine 77 in the brain calmodulin is not essential for the interaction with ophiobolin A and that lysine 75 is the more probable site of reaction. Several similarities exist between the inhibition of maize calmodulin by ophiobolin A in vitro and the effects of ophiobolin A on excised roots. Both are irreversible and time-dependent. The concentration of ophiobolin A for half-maximal inhibition of calmodulin in the phosphodiesterase assay is similar to that for phytotoxicity. In both cases, ophiobolin A derivatives behave similarly, i.e., 18-bromo-19-methoxyophiobolin A is as potent as ophiobolin A, whereas 3-anhydro-ophiobolin A and 6-epi-ophiobolin A are less potent. A smaller amount of active calmodulin was measured in the extract from roots treated with ophiobolin A than in those from untreated roots. These similarities suggest that calmodulin is a target protein for the phytotoxicity of ophiobolin A

The Economics of Late Marriage.

The trend of late marriage is found in various countries across the world in recent years. Discussion on this matter in the past mainly explored the problem from a social-cultural perspective. This paper attempts a different approach by trying to look at the matter from the perspective of both man and women and explains the causes of their actions by applying some economic theory

Growth-differentiation factor-8 (GDF-8) in the uterus: its identification and functional significance in the golden hamster

Transforming growth factor-beta superfamily regulates many aspects of reproduction in the female. We identified a novel member of this family, growth-differentiation factor 8 (GDF-8) in the 72 h post coital uterine fluid of the golden hamster by proteomic techniques. Uterine GDF-8 mRNA decreased as pregnancy progressed while its active protein peaked at 72 h post coitus (hpc) and thereafter stayed at a lower level. At 72 hpc, the GDF-8 transcript was localized to the endometrial epithelium while its protein accumulated in the stroma. Exogenous GDF-8 slowed down proliferation of primary cultures of uterine smooth muscle cells (SMC) and endometrial epithelial cells (EEC). In addition, GDF-8 attenuated the release of LIF (leukaemia inhibiting factor) by EEC. As for the embryo in culture, GDF-8 promoted proliferation of the trophotoderm (TM) and hatching but discouraged attachment. Our study suggests that GDF-8 could regulate the behavior of preimplantation embryos and fine-tune the physiology of uterine environment during pregnancy

The Impact of Transcatheter Atrial Septal Defect Closure in the Older Population A Prospective Study

ObjectivesWe sought to prove that device closure of atrial septal defect (ASD) in older patients not only improves cardiac function but also results in symptomatic relief by improving functional class.BackgroundAtrial septal defect accounts for approximately 10% of all congenital cardiac defects. It is possible that ASD closure in older patients may derive benefits, though this is not well established. We therefore aim to prospectively assess the clinical status and functional class of older patients after transcatheter ASD closure.MethodsThis was a prospective study of all patients age 40 years or more who underwent device closure of a secundum ASD between April 2004 and August 2006. Investigations including atrial and brain natriuretic peptide levels, electrocardiography, chest X-ray, transthoracic echocardiogram, 6-min walk test, and quality of life questionnaire were performed before and at 6 weeks and 1 year after the procedure.ResultsTwenty-three patients (median age 70 years, 13 women) had transcatheter device closure of ASD. Median ASD size was 18 mm (range 9 to 30 mm). Median pulmonary artery pressure was 22 mm Hg (range 12 to 27 mm Hg). At 1 year, New York Heart Association functional class improved (p = 0.004) in 16 patients with significant improvement in 6-min walk-test distance (p = 0.004) and physical (p = 0.002) as well as mental health score (p = 0.03). There were no major complications. One year following closure there was a significant change in left ventricular end-diastolic (p = 0.001) and end-systolic dimensions (p = 0.001) and also significant reduction in right ventricular end-diastolic dimension (p < 0.001).ConclusionsOur data demonstrated that ASD closure at advanced age results in favorable cardiac remodeling and improvement of functional class

Toolbox for Exploring Modular Gene Regulation in Synthetic Biology Training

We report a toolbox for exploring the modular tuning of genetic circuits, which has been specifically optimized for widespread deployment in STEM environments through a combination of bacterial strain engineering and distributable hardware development. The transfer functions of 16 genetic switches, programmed to express a GFP reporter under the regulation of the (acyl-homoserine lactone) AHL-sensitive luxR transcriptional activator, can be parametrically tuned by adjusting high/low degrees of transcriptional, translational, and post-translational processing. Strains were optimized to facilitate daily large-scale preparation and reliable performance at room temperature in order to eliminate the need for temperature controlled apparatuses, which are both cost-limiting and space-constraining. The custom-designed, automated, and web-enabled fluorescence documentation system allows time-lapse imaging of AHL-induced GFP expression on bacterial plates with real-time remote data access, thereby requiring trainees to only be present for experimental setup. When coupled with mathematical models in agreement with empirical data, this toolbox expands the scalability and scope of reliable synthetic biology experiments for STEM training

Circulating Levels of Adipocyte and Epidermal Fatty Acid–Binding Proteins in Relation to Nephropathy Staging and Macrovascular Complications in Type 2 Diabetic Patients

OBJECTIVE—To investigate the relationships of serum adipocyte fatty acid–binding protein (A-FABP) and epidermal fatty acid–binding protein (E-FABP) with renal dysfunction and macrovascular complications in type 2 diabetic patients

Automated whole-cell patch-clamp electrophysiology of neurons in vivo

Whole-cell patch-clamp electrophysiology of neurons is a gold-standard technique for high-fidelity analysis of the biophysical mechanisms of neural computation and pathology, but it requires great skill to perform. We have developed a robot that automatically performs patch clamping in vivo, algorithmically detecting cells by analyzing the temporal sequence of electrode impedance changes. We demonstrate good yield, throughput and quality of automated intracellular recording in mouse cortex and hippocampus.National Institutes of Health (U.S.) (NIH EUREKA Award program (1R01NS075421))National Institutes of Health (U.S.) ((NIH) Director′s New Innovator Award (DP2OD002002)National Science Foundation (U.S.) ((NSF) CAREER award (CBET 1053233))New York Stem Cell Foundation (Robertson Neuroscience Award)Dr. Gerald Burnett and Marjorie BurnettNational Science Foundation (U.S.) (grant CISE 1110947)National Science Foundation (U.S.) (grant EHR 0965945)American Heart Association (10GRNT4430029

Prognostic significance of CD26 in patients with colorectal cancer

Background: CD26, dipeptidyl peptidase IV, was discovered firstly as a membrane-associated peptidase on the surface of leukocyte. We previously demonstrated that a subpopulation of CD26+ cells were associated with the development of distant metastasis, enhanced invasiveness and chemoresistance in colorectal cancer (CRC). In order to understand the clinical impact of CD26, the expression was investigated in CRC patient's specimens. This study investigated the prognostic significance of tumour CD26 expression in patients with CRC. Examination of CD26+ cells has significant clinical impact for the prediction of distant metastasis development in colorectal cancer, and could be used as a selection criterion for further therapy. Methods: Tumour CD26 expression levels were studied by immunohistochemistry using Formalin-fixed paraffin embedded (FFPE) tissues in 143 patients with CRC. Tumour CD26 expression levels were correlated with clinicopathological features of the CRC patients. The prognostic significance of tumour tissue CD26 expression levels was assessed by univariate and multivariate analyses. Result: CD26 expression levels in CRC patients with distant metastasis were significantly higher than those in non-metastatic. High expression levels of CD26 were significantly associated with advanced tumour staging. Patients with a high CD26 expression level had significantly worse overall survival than those with a lower level (p<0.001). Conclusions: The expression of CD26 was positively associated with clinicopathological correlation such as TNM staging, degree of differentiation and development of metastasis. A high CD26 expression level is a predictor of poor outcome after resection of CRC. CD26 may be a useful prognostic marker in patients with CRC. © 2014 Lam et al.published_or_final_versio

miR-126-3p promotes matrix-dependent perivascular cell attachment, migration and intercellular interaction

microRNAs (miRNAs) can regulate the interplay between perivascular cells (PVC) and endothelial cells (EC) during angiogenesis, but the relevant PVC-specific miRNAs are not yet defined. Here, we identified miR-126-3p and miR-146a to be exclusively upregulated in PVC upon interaction with EC, determined their influence on the PVC phenotype and elucidate their molecular mechanisms of action. Specifically the increase of miR-126-3p strongly promoted the motility of PVC on the basement membrane-like composite and stabilized networks of endothelial cells. Subsequent miRNA target analysis showed that miR-126-3p inhibits SPRED1 and PLK2 expression, induces ERK1/2 phosphorylation and stimulates TLR3 expression to modulate cell-cell and cell-matrix contacts of PVC. Gain of expression experiments in vivo demonstrated that miR-126-3p stimulates PVC coverage of newly formed vessels and transform immature into mature, less permeable vessels. In conclusion we showed that miR-126-3p regulates matrix-dependent PVC migration and intercellular interaction to modulate vascular integrity