Relativistic boost as the cause of periodicity in a massive black-hole binary candidate.

Because most large galaxies contain a central black hole, and galaxies often merge, black-hole binaries are expected to be common in galactic nuclei. Although they cannot be imaged, periodicities in the light curves of quasars have been interpreted as evidence for binaries, most recently in PG 1302-102, which has a short rest-frame optical period of four years (ref. 6).

Phosphorylation of Tyr245 in the open-inhibited state of Abelson kinase does not induce downstream signaling.

Binding of tyrosine kinase inhibitors such as imatinib was shown to induce a novel open-inhibited conformation of BCR-ABL, in which Tyr245 is exposed and prone to phosphorylation. To evaluate whether this leads to priming of the kinase in cellular systems, we probed activation of downstream signaling as a result of Tyr245 phosphorylation in a series of cellular washout experiments. While a spike in Tyr245 phosphorylation was observed both in overexpression and endogenous settings, no induction of downstream signaling was detected, showing that the priming hypothesis is not relevant for the therapeutic situation.

Overexpression of Wnt target genes in adenomas of familial adenomatous polyposis patients.

Germline mutations within the adenomatous polyposis coli (APC) gene, a key member of the Wnt signalling pathway, have been shown to cause adenoma development in familial adenomatous polyposis (FAP), a dominantly inherited predisposition to colorectal cancer. Although it has been suggested for several years that alterations within the Wnt pathway are the underlying events for the development of colorectal adenomas in FAP patients, no detailed analysis of the gene expressions of Wnt pathway members has been available in fresh colorectal tissue of FAP patients, so far. Thus, we investigated potential differences in the expressions of APC and its Wnt partners conductin, beta-catenin, cyclin D1, and c-myc in normal colorectal mucosa and matched adenoma tissue of 14 FAP patients using real-time quantitative PCR.

Endothelial, but not the inducible, nitric oxide synthase is detectable in normal and portal hypertensive rats.

Background: Chronic portal hypertension is accompanied by a nitric oxide (NO) dependent vasodilation. Three isoforms of NO producing synthases (NOS) are characterized: neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Sources of increased NO levels in chronic hypertension is disputed.

Expression of COX-2 and Wnt pathway genes in adenomas of familial adenomatous polyposis patients treated with meloxicam.

Background: Familial adenomatous polyposis (FAP) is an autosomal, dominantly inherited predisposition to colorectal cancer caused by germline mutations within the adenomatous polyposis coli (APC) gene, a key member of the Wnt signalling pathway. A new class of non-steroidal anti-inflammatory drugs (NSAIDs), the specific cyclooxygenase 2 (COX-2) inhibitors, have recently been applied for the treatment of FAP patients.

Patients And Methods: The expressions of the Wnt members and targets APC, c-myc, cyclin D1 and COX-2, as measured by real-time quantitative RT-PCR, have been evaluated in fresh samples of normal colorectal mucosa and matched adenoma tissue of six unrelated FAP patients before and after treatment with meloxicam.