Early conception factor lateral flow assays for pregnancy in the mare

The ECF™ lateral flow assay test is marketed to detect non-pregnancy in mares. The objectives of the present study were to determine the accuracy of the ECF test, the accuracy of the electronic reader accompanying the ECF test, and agreement between two human readers and the electronic reader. Serum samples were collected from anestrus, cycling but not inseminated, and inseminated mares, and were evaluated with the ECF™ test (EDP Biotech Company, Knoxville, TN, USA) at The Ohio State University and at the EDP Biotech Laboratory. Specificity ranged from 0.07 to 0.16, the negative predictive value ranged from 0.15 to 0.33, and accuracy ranged from 0.43 to 0.52. The electronic reader did not add improve the accuracy or predictive values of the test. Based on the electronic reader, 80.0% of the serum samples collected from the anestrus mares were false positives; Readers 1 and 2 had 60.0 and 33.3% false positives, respectively. For samples collected during the estrous cycle, 83.9% were false positives by the electronic reader, whereas Readers 1 and 2 had 43.7 and 26.4% false positives. We concluded that, regardless of whether the test strips were evaluated by a human or electronic reader, this assay was not accurate for determination of the non-pregnant mare.     

Fluorescent energy transfer measurements on fluorescein isothiocyanate modified cytochrome P-450 LM2

The distance between the heme iron and the N-terminus of cytochrome P-450 LM2 was determined by fluorescence energy transfer measurements. Fluorescein isothiocyanate which was covalently bound to the N-terminal methionine was used as donor chromophor. The Ro value between fluorescein isothiocyanate and the heme was calculated to be 3.98 nm. The distance between the nitrogen of the N-terminal methionine and the heme was estimated with 2.84 +/- 0.23 nm excluding most likely the N-terminal amino acid of cytochrome P-450 LM2 to participate in the electron transfer to the heme iron. A cytochrome P-450 LM2 membrane model is proposed.     

Über die gesteigerte Peroxydaseaktivität in gestörtenPhaseolus-Artbastarden

Ohne ZusammenfassungMit 3 Textabbildungen     

Über die Fraktionierung des Protoplasmas vonPhaseolus-Arten undPhaseolus-Artbastarden

Zusammenfassung Es werden Beispiele für die Fraktionierung des Protoplasmas der Blätter vonPhaseolus vulgaris, Phaseolus coccineus undPhaseolus vulgaris ()×Phaseolus coccineus () mitgeteilt. Die Zahlen lassebn keine sicheren Unterschiede zwischen den entsprechenden partiklären und Grundplasmafraktionen der Elternarten und Bastarde erkennen, doch zeigen sich Differenzen, wenn die Partikel- und Grundplasmafraktionen jeweils zusammengefaßt und die Quotienten Partikel-Nucleinsäure/Grundplasma-Nucleinsäure (NS_P/NS_G) und Partikel-Eiweiß/Grundplasma-Eiweiß (E_P/E_G) gebildet werden. Diese Quotienten liegen beiPhaseolus vulgaris niedriger als beiPhaseolus coccineus, und bei den nichtgestörten Bastarden stimmt der Quotient E_P/E_G praktisch mit dem vonPhaseolus coccineus überein, wähert ist. Die gestörten Bastarde ähneln im Nucleinsäuregehalt den Elternarten und den normalen Bastarden, doch ist in allen Fraktionen, besonders stark in den Chloroplasten, der Eiweißanteil bezogen auf Frischsubstanz und Nucleinsäure vermindert.—Nucleinsäure und Eiweiß nehmen mit der Entwicklung der Blätter ab, dabei wird das Verhältnis Eiweiß/Nucleinsäure, eine Fraktion ausgenommen, stark zugungsten des Eiweißes verschoben, ferner findet eine Verschiebung der Quotienten NS_P/NS_G und E_P/E_G zugunsten der partikeln statt. Eine Abhängigkeit der Quotienten vom Gesamteiweiß oder der Gesamtnucleinsäure, die beide in den einzelnen Versuchen stark variieren, ist nicht festzustellen. Die Befunde zeigen, daß die in den Bastarden enthaltenen Kerngene vonPhaseolus coccineus das Verhältnis der Plasmakomponenten der Mutter, das bei völliger Unabhängigkeit und Selbständigkeit mit dem vonPhaseolus vulgaris übereinstimmen müßte, wesentlich beeinflussen. Sie werden unter dem Gesichtspunkt der Konkurrenzbeziehungen zwischen den Plasmakomponenten, deren Zusammenspiel den Stoffwechsel der Zellen ergibt, diskutiert.     

A loss of insulin-like growth factor-2 imprinting is modulated by CCCTC-binding factor down-regulation at senescence in human epithelial cells

The imprinted insulin-like growth factor-2 (IGF2) gene is an auto/paracrine growth factor expressed only from the paternal allele in adult tissues. In tissues susceptible to aging-related cancers, including the prostate, a relaxation of IGF2 imprinting is found, suggesting a permissive role for epigenetic alterations in cancer development. To determine whether IGF2 imprinting is altered in cellular aging and senescence, human prostate epithelial and urothelial cells were passaged serially in culture to senescence. Allelic analyses using an IGF2 polymorphism demonstrated a complete conversion of the IGF2 imprint status from monoallelic to biallelic, in which the development of senescence was associated with a 10-fold increase in IGF2 expression. As a mechanism, a 2-fold decrease in the binding of the enhancer-blocking element CCCTC-binding factor (CTCF) within the intergenic IGF2-H19 region was found to underlie this switch to biallelic IGF2 expression in senescent cells. This decrease in CTCF binding was associated with reduced CTCF expression in senescent cells. No de novo increases in methylation at the IGF2 CTCF binding site were seen. The forced down-regulation of CTCF expression using small interfering RNA in imprinted prostate cell lines resulted in an increase in IGF2 expression and a relaxation of imprinting. Our data suggest a novel mechanism for IGF2 imprinting regulation, that is, the reduction of CTCF expression in the control of IGF2 imprinting. We also demonstrate that altered imprinting patterns contribute to changes in gene expression in aging cells.     

Zur Methodik der Kautschukbestimmung in Pflanzen

Ohne Zusammenfassung