1,211 research outputs found
Impact of the New Measurement of the 12C + 12C Fusion Cross Section on the Final Compactness of Massive Stars
No full textWe discuss how the new measurement of the 12C + 12C fusion cross section carried out with the Trojan Horse Method affects the compactness of a star, i.e., basically the binding energy of the inner mantle, at the onset of the core collapse. In particular, we find that this new cross section significantly changes the dependence of the compactness on the initial mass with respect to previous findings obtained in Chieffi & Limongi by adopting the classical cross section provided by Caughlan & Fowler. A non-monotonic but well-defined behavior is also confirmed in this case and no scatter of the compactness around the main trend is found. Such an occurrence could impact the possible explodability of the stars
D-aspartate modulates transcriptional activity in Harderian gland of frog, Rana esculenta: Morphological and molecular evidence
No full textIn the green frog, Rana esculenta, a substantial amount Of D-aspartate (D-Asp) is found enclogenously within the Harderian gland (HG) following its synthesis from (L)-aspartate ((L)-Asp) by an aspartate racemase. The frog HG is an orbital seromucoid gland that displays seasonal changes in secretory activity. Our in vivo experiments, consisting of i.p. injection of 2.0 mu mol/g.b.w. (D)-Asp in frogs collected during two periods of differing glandular activity (high or medium-low secretory activity), revealed that HG can to take up and accumulate D-Asp and that this amino acid may modulate the exocrine secretion through a kinase pathway. Atatirnewhenthe gland shows relatively low secretory activity, i.p. administration of (D)-Asp rapidly induced activation of ERK1 and an increase in cells active in RNA synthesis. This increase in transcriptional activity was followed by a significant increase in Mucous secretion. By contrast, administration of exogenous (D)-Asp when HG was showing high activity rapidly induced inhibition of both ERK1 and transcriptional activity. Since D-Asp is known to be recognized by receptors for N-methyl-(D)-aspartic acid (NMDA), it is possible that in the HG, D-Asp mediated NMDA activation may enhance the kinase pathway. The above activation of opposing stimulatory and inhibitory processes could reflect different levels of NMDA-receptor activity, which could vary as a function of the level of gland activity. This study provides the first evidence of a role for this excitatory amino acid in exocrine secretion. The effects of (D)-Asp in HG appear to be specific since they were not seen in frogs treated with other (D)- or (L)-amino acids with known excitatory effects on neurosecretion. (c) 2005 Wiley-Liss, Inc
GPR30 is a potential therapeutic target in human carcinoma in situ and seminomas.
No full textThe G protein-coupled estrogen receptor (GPR30) is suggested to exert a role in non-nuclear estrogen signalling and is over-expressed in a variety of hormone dependent cancer entities. It is well established that oestrogens are involved in testicular germ cell tumours. In a recent paper published in Journal of Cellular Physiology, we show that down regulation of estrogen receptor ? (ER?) associates with GPR30 over-expression both in human testicular carcinoma in situ (CIS) and seminomas. In addition, we demonstrate that 17b-oestradiol induces the ERK1/2 activation through GPR30. The results suggested that exposure to oestrogens or oestrogen-mimics, in some as of yet undefined manner, diminishes the ERb-mediated growth restraint in CIS and in human testicular seminoma, indicating that GPR30 could be a potential therapeutic target to design specific inhibitors
Molecular biomarkers as potential targets for therapeutic strategies in human testicular germ cell tumors: an overview.
No full textTesticular germ cell tumors (TGCTs), the most common malignancy in males between 15 and 34 years of age and the most frequent cause of death from solid tumors in this age group. TGCTs can be subdivided into seminoma and non-seminoma germ cell tumors (NSGCTs), including embryonal cell carcinoma, choriocarcinoma, yolk sac tumor, and teratoma. Seminomas and NSGCTs do not only present distinctive clinical features, but they also show significant differences as far as therapy and prognosis are concerned. Seminomas are highly sensitive to both radiation and chemotherapy, with a good prognosis, non-seminomas are sensitive to platinum-based combination chemotherapy and are less susceptible to radiation, with the exception of teratomas. The different therapeutic outcome might be explained by inherent properties of the cells from which testicular neoplasia originate. The unique treatment sensitivity of TGCTs is unexplained so far, but it is likely to be related to intrinsic molecular characteristics of the PGCs/gonocytes, from which these tumors originate. Many discovered bio-markers including OCT3/4, SOX2, SOX17, HMGA1, HMGA2, PATZ1, GPR30, Aurora B, estrogen receptor b, and others have given further advantages to discriminate between histological subgroups. In addition, therapeutic approaches for the treatment of TGCTs have been proposed: humanized antibodies against receptors/surface molecules on cancer cells, inhibitors of serine–threonine, and tyrosine kinases, and others. The mini-review will be an overview on the molecular alterations identified in TGCTs and on novel targeted antineoplastic strategies that might help to treat chemotherapy resistant TGCTs
Memoria per la distanza e la direzione di stimoli da raggiungere: indipendenza dei due sistemi di codifica
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