44 research outputs found
Examining the effects of a professional development program on teachers' pedagogical practices and students' motivational resources and achievement in written french
We tested the effects of a professional development program (CASIS) on teachers' pedagogical practices and students'
motivation and achievement in written French. CASIS involved a two-day workshop in which we taught
teachers to use collaboration, autonomy support, authentic tasks, involvement, and structure. We conducted a
quasi-experimental longitudinal study among 18 elementary school teachers and 277 of their students. The results
showed large group effect sizes for four of the five pedagogical practices and increased intrinsic motivation
for students whose teachers attended CASIS. The discussion centers on the implications of these findings for research
and practice
TLN-4601 suppresses growth and induces apoptosis of pancreatic carcinoma cells through inhibition of Ras-ERK MAPK signaling
Abstract Background TLN-4601 is a structurally novel farnesylated dibenzodiazepinone discovered using Thallion's proprietary DECIPHER® technology, a genomics and bioinformatics platform that predicts the chemical structures of secondary metabolites based on gene sequences obtained by scanning bacterial genomes. Our recent studies suggest that TLN-4601 inhibits the Ras-ERK MAPK pathway post Ras prenylation and prior to MEK activation. The Ras-ERK MAPK signaling pathway is a well-validated oncogenic cascade based on its central role in regulating the growth and survival of cells from a broad spectrum of human tumors. Furthermore, RAS isoforms are the most frequently mutated oncogenes, occurring in approximately 30% of all human cancers, and KRAS is the most commonly mutated RAS gene, with a greater than 90% incidence of mutation in pancreatic cancer. Results To evaluate whether TLN-4601 interferes with K-Ras signaling, we utilized human pancreatic epithelial cells and demonstrate that TLN-4601 treatment resulted in a dose- and time-dependent inhibition of Ras-ERK MAPK signaling. The compound also reduced Ras-GTP levels and induced apoptosis. Finally, treatment of MIA PaCa-2 tumor-bearing mice with TLN-4601 resulted in antitumor activity and decreased tumor Raf-1 protein levels. Conclusion These data, together with phase I/II clinical data showing tolerability of TLN-4601, support conducting a clinical trial in advanced pancreatic cancer patients
Defective migration of neuroendocrine GnRH cells in human arrhinencephalic conditions
Patients with Kallmann syndrome (KS) have hypogonadotropic hypogonadism caused by a deficiency of gonadotropin-releasing hormone (GnRH) and a defective sense of smell related to olfactory bulb aplasia. Based on the findings in a fetus affected by the X chromosome–linked form of the disease, it has been suggested that hypogonadism in KS results from the failed embryonic migration of neuroendocrine GnRH1 cells from the nasal epithelium to the forebrain. We asked whether this singular observation might extend to other developmental disorders that also include arrhinencephaly. We therefore studied the location of GnRH1 cells in fetuses affected by different arrhinencephalic disorders, specifically X-linked KS, CHARGE syndrome, trisomy 13, and trisomy 18, using immunohistochemistry. Few or no neuroendocrine GnRH1 cells were detected in the preoptic and hypothalamic regions of all arrhinencephalic fetuses, whereas large numbers of these cells were present in control fetuses. In all arrhinencephalic fetuses, many GnRH1 cells were present in the frontonasal region, the first part of their migratory path, as were interrupted olfactory nerve fibers that formed bilateral neuromas. Our findings define a pathological sequence whereby a lack of migration of neuroendocrine GnRH cells stems from the primary embryonic failure of peripheral olfactory structures. This can occur either alone, as in isolated KS, or as part of a pleiotropic disease, such as CHARGE syndrome, trisomy 13, and trisomy 18
The Pre-Modern Manuscript Trade and its Consequences, ca. 1890-1945
This collection brings together current research into the development of the market for pre-modern manuscripts. Between 1890 and 1945 thousands of manuscripts made in Europe before 1600 appeared on the market. Many entered the collections in which they have remained, shaping where and how we encounter the books today. These collections included libraries that bear
their founders’ names, as well as national and regional public libraries. The choices of the super-rich shaped their collections and determined what was available to those with fewer resources. In addition, wealthy collectors sponsored scholarship on their manuscripts and participated in exhibitions, raising the profile of some books. The volume examines the collectors, dealers, and
scholars who engaged with pre-modern books, and the cultural context of the manuscript trade in this era
L'oxydation biologique des stéroïdes
L'hydroxylation enzymatique, en particulier à des sites chimiquement inactifs, de même que la scission oxydative de la chaîne latérale des stéroïdes demeurent des phénomènes partiellement connus. La section théorique de cette thèse revise les grandes théories sur le sujet. La première partie de notre travail expérimental rapporte l'influence inhibitrice de substituants méthyle ou éthinyle en position 17x de stéroïdes de la série androstane sur l'hydroxylation enzymatique par des préparations acellulaires de l'Aspergillus Ochraceus. La deuxième partie est consacrée à l'étude chimique et biochimique de deux dérivés 17x-hydroperoxyprégnènes, la 17x-hydroperoxyprogestérone et la 17x-hydroperoxypregnénolone. L'évaluation de leur rôle possible comme intermédiaires dans les réactions l'hydroxylation biologique nous amène à élaborer une hypothèse nouvelle sur la biosynthèse des hormones corticosurrénaliennes. Après une étude de l'interaction entre ces substrats hydroperoxydes et des préparations de cytochrome P-450 du cortex surrénalien de bovins, nous rapportons la synthèse de la 17x-hydroperoxyprogestérone marquée à l'oxygène-18 et le résultat de sa conversion par une préparation microsomale de cortex surrénalien. La conversion enzymatique de la 17x-18 0-hydroperoxyprogestérone en androstènedione marqué, catalysée par cette préparation microsomale en l'absence d'oxygène constitue, à notre avis, une découverte originale qui nous permet de proposer un nouveau mécanisme de scission de la chaîne latérale des dérivés 20-cétoprégnanes en milieu biologique animal
L'oxydation biologique des stéroïdes
L'hydroxylation enzymatique, en particulier à des sites chimiquement inactifs, de même que la scission oxydative de la chaîne latérale des stéroïdes demeurent des phénomènes partiellement connus. La section théorique de cette thèse revise les grandes théories sur le sujet. La première partie de notre travail expérimental rapporte l'influence inhibitrice de substituants méthyle ou éthinyle en position 17x de stéroïdes de la série androstane sur l'hydroxylation enzymatique par des préparations acellulaires de l'Aspergillus Ochraceus. La deuxième partie est consacrée à l'étude chimique et biochimique de deux dérivés 17x-hydroperoxyprégnènes, la 17x-hydroperoxyprogestérone et la 17x-hydroperoxypregnénolone. L'évaluation de leur rôle possible comme intermédiaires dans les réactions l'hydroxylation biologique nous amène à élaborer une hypothèse nouvelle sur la biosynthèse des hormones corticosurrénaliennes. Après une étude de l'interaction entre ces substrats hydroperoxydes et des préparations de cytochrome P-450 du cortex surrénalien de bovins, nous rapportons la synthèse de la 17x-hydroperoxyprogestérone marquée à l'oxygène-18 et le résultat de sa conversion par une préparation microsomale de cortex surrénalien. La conversion enzymatique de la 17x-18 0-hydroperoxyprogestérone en androstènedione marqué, catalysée par cette préparation microsomale en l'absence d'oxygène constitue, à notre avis, une découverte originale qui nous permet de proposer un nouveau mécanisme de scission de la chaîne latérale des dérivés 20-cétoprégnanes en milieu biologique animal