409 research outputs found

    K-Ar biotite ages of the coarse-grained granites from the Inada area, Ibaraki Prefecture: Evaluation of suitability for a new K-Ar dating standard

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    K-Ar ages have been determined on biotite fractions of three coarse-grained granites from the Inada area, Ibaraki Prefecture. Ages are 65.0 +/- 2.3 Ma for Inada-I, 63.7 +/- 2.2 Ma for Inada-II and 62.1 +/- 2.8 Ma for Inada-III. The Inada-II sample is a better candidate than the other two samples as a K-Ar dating standard on the basis of thin section observation and K-Ar dating results. However, a chlorite removal step is necessary to make the new dating standard

    Biphasic Roles of Clock Genes and Bone Morphogenetic Proteins in Gonadotropin Expression by Mouse Gonadotrope Cells

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    Roles of Clock genes and the bone morphogenetic protein (BMP) system in the regulation of gonadotropin secretion by gonadotropin-releasing hormone (GnRH) were investigated using mouse gonadotropin L beta T2 cells. It was found that luteinizing hormone (LH)beta mRNA expression level in L beta T2 cells changed gradually over time, with LH beta expression being suppressed in the early phase up to 12 h and then elevated in the late phase 24 h after GnRH stimulation. In addition, the mRNA expression levels of Clock genes, including Bmal1, Clock, Per2, and Cry1, also showed temporal changes mimicking the pattern of LH beta expression in the presence and absence of GnRH. Notably, the expression levels of Bmal1 and Clock showed strong positive correlations with LH beta mRNA expression levels. Moreover, a functional link of the ERK signaling of mitogen-activated protein kinases (MAPKs) in the suppression of LH beta mRNA expression, as well as Bmal1 and Clock mRNA expression by GnRH at the early phase, was revealed. Inhibition of Bmal1 and Clock expression using siRNA was involved in the reduction in LH beta mRNA levels in the late phase 24 h after GnRH stimulation. Furthermore, in the presence of BMP-6 and -7, late-phase Bmal1 and LH beta mRNA expression after GnRH stimulation was significantly attenuated. Collectively, the results indicated that LH expression in gonadotrope cells exhibits Bmal1/Clock-dependent fluctuations under the influence of GnRH and that the fluctuations are regulated by ERK and BMPs in the early and late stages, respectively, in a phase-dependent manner after GnRH stimulation.</p

    Orexin A Enhances Pro-Opiomelanocortin Transcription Regulated by BMP-4 in Mouse Corticotrope AtT20 Cells

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    Orexin is expressed mainly in the hypothalamus and is known to activate the hypothalamic-pituitary-adrenal (HPA) axis that is involved in various stress responses and its resilience. However, the effects of orexin on the endocrine function of pituitary corticotrope cells remain unclear. In this study, we investigated the roles of orexin A in pro-opiomelanocortin (POMC) transcription using mouse corticotrope AtT20 cells, focusing on the bone morphogenetic protein (BMP) system expressed in the pituitary. Regarding the receptors for orexin, type 2 (OXR2) rather than type 1 (OX1R) receptor mRNA was predominantly expressed in AtT20 cells. It was found that orexin A treatment enhanced POMC expression, induced by corticotropin-releasing hormone (CRH) stimulation through upregulation of CRH receptor type-1 (CRHR1). Orexin A had no direct effect on the POMC transcription suppressed by BMP-4 treatment, whereas it suppressed Smad1/5/9 phosphorylation and Id-1 mRNA expression induced by BMP-4. It was further revealed that orexin A had no significant effect on the expression levels of type I and II BMP receptors but upregulated inhibitory Smad6/7 mRNA and protein levels in AtT20 cells. The results demonstrated that orexin A upregulated CRHR signaling and downregulated BMP-Smad signaling, leading to an enhancement of POMC transcription by corticotrope cells

    Favorable Outcome of Repeated Salvage Surgeries for Rare Metastasis to the Ligamentum Teres Hepatis and the Upper Abdominal Wall in a Stage IV Gastric Cancer Patient

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    Gastric cancer with peritoneal metastases is typically a devastating diagnosis. Ligamentum teres hepatis (LTH) metastasis is an extremely rare presentation with only four known cases. Herein, we report salvage surgery of successive metastases to the abdominal wall and LTH in a patient originally presenting with advanced gastric cancer with peritoneal metastasis, leading to long-term survival. A 72-year-old man with advanced gastric cancer underwent curative-intent distal gastrectomy with D2 lymph node dissection for gastric outlet obstruction. During this procedure, three small peritoneal metastases were detected in the lesser omentum, the small mesentery, and the mesocolon; however, intraoperative abdominal lavage cytology was negative. We added cytoreductive surgery for peritoneal metastasis. The pathological diagnosis of the gastric cancer was tubular adenocarcinoma with pT4aN1pM1(PER/P1b)CY0 stage IV (Japanese classification of gastric carcinoma/JCGC 15th), or T4N1M1b stage IV (UICC 7th). Post-operative adjuvant chemotherapy with S-1 (TS-1)+cisplatin (CDDP) was administered for 8 months followed by S-1 monotherapy for 4 months. At 28 months after the initial surgery, a follow-up computed tomography (CT) detected a small mass beneath the upper abdominal wall. The ass showed mild avidity on 18F-fluorodeoxyglucose positron-emission (FDG-PET) CT. Salvage resection was performed for diagnosis and treatment, and pathological findings were consistent with primary gastric cancer metastasis. At 49 months after the initial gastrectomy, a new lesion was detected in the LTH with a similar level of avidity on FDG-PET CT as the abdominal wall metastatic lesion. We performed a second salvage surgery for the LTH tumor, which also showed pathology of gastric cancer metastasis. There has been no recurrence up to 1 year after the LTH surgery. With multidisciplinary treatment the patient has survived almost 5 years after the initial gastrectomy. Curative-intent gastrectomy with cytoreductive surgery followed by adjuvant chemotherapy for advanced gastric cancer with localized peritoneal metastasis might have had a survival benefit in our patient. Successive salvage surgeries for oligometastatic lesions in the abdominal wall and the LTH also yielded favorable outcomes

    Optimizing Charge Switching in Membrane Lytic Peptides for Endosomal Release of Biomacromolecules.

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    Endocytic pathways are practical routes for the intracellular delivery of biomacromolecules. Along with this, effective strategies for endosomal cargo release into the cytosol are desired to achieve successful delivery. Focusing on compositional differences between the cell and endosomal membranes and the pH decrease within endosomes, we designed the lipid-sensitive and pH-responsive endosome-lytic peptide HAad. This peptide contains aminoadipic acid (Aad) residues, which serve as a safety catch for preferential permeabilization of endosomal membranes over cell membranes, and His-to-Ala substitutions enhance the endosomolytic activity. The ability of HAad to destabilize endosomal membranes was supported by model studies using large unilamellar vesicles (LUVs) and by increased intracellular delivery of biomacromolecules (including antibodies) into live cells. Cerebral ventricle injection of Cre recombinase with HAad led to Cre/loxP recombination in a mouse model, thus demonstrating potential applicability of HAad in vivo

    On the Security of the Schnorr Signature Scheme and DSA against Related-Key Attacks

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    In the ordinary security model for signature schemes, we consider an adversary that may forge a signature on a new message using only his knowledge of other valid message and signature pairs. To take into account side channel attacks such as tampering or fault-injection attacks, Bellare and Kohno (Eurocrypt 2003) formalized related-key attacks (RKA), where stronger adversaries are considered. In RKA for signature schemes, the adversary can also manipulate the signing key and obtain signatures for the modified key. This paper considers RKA security of two established signature schemes: the Schnorr signature scheme and (a well-known variant of) DSA. First, we show that these signature schemes are secure against a weak notion of RKA. Second, we demonstrate that, on the other hand, neither the Schnorr signature scheme nor DSA achieves the standard notion of RKA security, by showing concrete attacks on these. Lastly, we show that a slight modification of both the Schnorr signature scheme and (the considered variant of) DSA yields fully RKA secure schemes

    Mutual Effects of Orexin and Bone Morphogenetic Proteins on Gonadotropin Expression by Mouse Gonadotrope Cells

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    Orexin plays a key role in the regulation of sleep and wakefulness and in feeding behavior in the central nervous system, but its receptors are expressed in various peripheral tissues including endocrine tissues. In the present study, we elucidated the effects of orexin on pituitary gonadotropin regulation by focusing on the functional involvement of bone morphogenetic proteins (BMPs) and clock genes using mouse gonadotrope L beta T2 cells that express orexin type 1 (OX1R) and type 2 (OX2R) receptors. Treatments with orexin A enhanced LH beta and FSH beta mRNA expression in a dose-dependent manner in the absence of GnRH, whereas orexin A in turn suppressed GnRH-induced gonadotropin expression in L beta T2 cells. Orexin A downregulated GnRH receptor expression, while GnRH enhanced OX1R and OX2R mRNA expression. Treatments with orexin A as well as GnRH increased the mRNA levels of Bmal1 and Clock, which are oscillational regulators for gonadotropin expression. Of note, treatments with BMP-6 and -15 enhanced OX1R and OX2R mRNA expression with upregulation of clock gene expression. On the other hand, orexin A enhanced BMP receptor signaling of Smad1/5/9 phosphorylation through upregulation of ALK-2/BMPRII among the BMP receptors expressed in L beta T2 cells. Collectively, the results indicate that orexin regulates gonadotropin expression via clock gene expression by mutually interacting with GnRH action and the pituitary BMP system in gonadotrope cells

    Enzymatic control of anhydrobiosis-related accumulation of trehalose in the sleeping chironomid, Polypedilum vanderplanki

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    Larvae of an anhydrobiotic insect, Polypedilum vanderplanki, accumulate very large amounts of trehalose as a compatible solute on desiccation, but the molecular mechanisms underlying this accumulation are unclear. We therefore isolated the genes coding for trehalose metabolism enzymes, i.e. trehalose-6-phosphate synthase (TPS) and trehalose-6-phosphate phosphatase (TPP) for the synthesis step, and trehalase (TREH) for the degradation step. Although computational prediction indicated that the alternative splicing variants (PvTpsα/β) obtained encoded probable functional motifs consisting of a typical consensus domain of TPS and a conserved sequence of TPP, PvTpsα did not exert activity as TPP, but only as TPS. Instead, a distinct gene (PvTpp) obtained expressed TPP activity. Previous reports have suggested that insect TPS is, exceptionally, a bifunctional enzyme governing both TPS and TPP. In this article, we propose that TPS and TPP activities in insects can be attributed to discrete genes. The translated product of the TREH ortholog (PvTreh) certainly degraded trehalose to glucose. Trehalose was synthesized abundantly, consistent with increased activities of TPS and TPP and suppressed TREH activity. These results show that trehalose accumulation observed during anhydrobiosis induction in desiccating larvae can be attributed to the activation of the trehalose synthetic pathway and to the depression of trehalose hydrolysis
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