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61.
Rizatriptan (MK-462) is a potent 5HTID receptor agonist. This multicenter, double-blind, placebo-controlled, outpatient study investigated the clinical efficacy, safety, and tolerability of rizatriptan (2.5, 5, and 10 mg) as a function of dose for acute migraine. Patients with moderate or severe migraine (n = 417) were treated with placebo (n = 67), rizatriptan 2.5 mg (n = 75), 5 mg (n = 130), or rizatriptan 10 mg (n = 145). Headache severity, functional disability, and migraine symptoms were measured immediately before dosing (0) and at 0.5, 1, 1.5, 2, 3, and 4 h post-dose. Patients were permitted to take a second dose of test drug at 2 h if their headache pain was moderate or severe (i.e., placebo initially-->rizatriptan 10 mg as optional second dose; rizatriptan 2.5 mg, 5 mg, or 10 mg initially-->placebo as optional second dose). An upward dose-response relationship was observed among placebo, rizatriptan 2.5 mg, 5 mg, and 10 mg in the primary efficacy measure of proportion of patients reporting pain relief, i.e., a change in headache severity to "no pain or mild pain" at 2 h post-dose. The relationship was evident even at the first recorded timepoint, 30 min, and was statistically significant at 1.5 h and beyond. At the primary timepoint of 2 h after the initial dose, the proportion of patients reporting pain relief was 47.6% for rizatriptan 10 mg; 45.4% for rizatriptan 5 mg; 21.3% for rizatriptan 2.5 mg; and 17.9% for placebo. Seventy percent of patients on rizatriptan 10 mg reported pain relief at 4 h. Patients who took rizatriptan 5 mg and 10 mg were significantly less functionally disabled than those who took placebo at 1.5 and 2 h post-dose. Rizatriptan 10 mg was consistently more effective than 5 mg, although the differences were not statistically significant. The most frequent clinical adverse events were dizziness, somnolence, and asthenia/fatigue. No patients were discontinued for any adverse experiences and there were no serious adverse experiences. 相似文献
62.
PURPOSE: Rhabdomyosarcomas (RMS) are heterogeneous in their clinical presentation, histology, and cytogenetics. The growth of some RMS cells has been found to be regulated by the tyrosine kinase insulin-like growth factor (IGF) type I receptor. However, RMS cells exhibit variable sensitivity to inhibitors of tyrosine kinases and IGF receptors. Collectively, these heterogeneous features suggest that differences exist in the growth regulatory pathways of RMS. The objective of this study is to identify active tyrosine kinase signal transduction pathways in embryonal and alveolar RMS cells. METHODS: RMS tumor samples and cell lines representing both embryonal and alveolar histologic subtypes have been analyzed by immunoprecipitation and immunoblotting techniques to characterize phosphotyrosyl protein patterns and to identify tyrosine phosphorylated proteins. RESULTS: RMS cells can be characterized based on the patterns of phosphotyrosyl proteins, including the phosphorylation status of the catenin-like protein Cas1 and the signal adapter protein SHC, and the activation of IGF type I receptor signaling cascades including the formation of SHC-GRB2 signal protein complexes and MAP kinase activation. CONCLUSIONS: Rhabdomyosarcomas, especially the embryonal histologic subtype, are heterogeneous at the level of tyrosine kinase signal transduction. It will be important to characterize the growth regulatory pathways active in individual RMS tumors before targeting molecular therapies to this malignancy. 相似文献
63.
Arun Muthukkumaran Shrayas Raghunathan Arjun Ravichandran Raghunathan Rengaswamy 《American Institute of Chemical Engineers》2023,69(7):e18068
With the ever-increasing volume of scientific literature, there is a strong need to develop methods that allow rigorous information identification. In this contribution, a state-of-the-art natural language processing (NLP) model was used to select perovskite materials for electrocatalytic applications from literature. This was accomplished by obtaining word embeddings for perovskite materials from the NLP model and subsequently designing downstream tasks to discover perovskite-based electrocatalyst materials. However, embeddings could be obtained only for materials available in the literature. Consequently, a novel methodology was devised to generate embeddings for newly designed materials. Results from the analysis showed that the computed embeddings could be used to rank materials for their suitability for electrocatalytic applications. Further, the word embeddings were also employed as features in predicting the electrocatalytic activity of perovskite-based electrocatalysts. The analysis demonstrated that the fidelity of regression models increased when the embeddings were used as features. 相似文献
64.
Lokesh Rajulapati Sivadurgaprasad Chinta Bala Shyamala Raghunathan Rengaswamy 《American Institute of Chemical Engineers》2022,68(6):e17715
Model building and parameter estimation are traditional concepts widely used in chemical, biological, metallurgical, and manufacturing industries. Early modeling methodologies focused on mathematically capturing the process knowledge and domain expertise of the modeler. The models thus developed are termed first principles models (or white-box models). Over time, computational power became cheaper, and massive amounts of data became available for modeling. This led to the development of cutting edge machine learning models (black-box models) and artificial intelligence (AI) techniques. Hybrid models (gray-box models) are a combination of first principles and machine learning models. The development of hybrid models has captured the attention of researchers as this combines the best of both modeling paradigms. Recent attention to this field stems from the interest in explainable AI (XAI), a critical requirement as AI systems become more pervasive. This work aims at identifying and categorizing various hybrid models available in the literature that integrate machine-learning models with different forms of domain knowledge. Benefits such as enhanced predictive power, extrapolation capabilities, and other advantages of combining the two approaches are summarized. The goal of this article is to consolidate the published corpus in the area of hybrid modeling and develop a comprehensive framework to understand the various techniques presented. This framework can further be used as the foundation to explore rational associations between several models. 相似文献
65.
Manoj Gaur Jaya Lohani R. Raman V.R. Balakrishnan P. Raghunathan S.V. Eswaran 《Synthetic Metals》2010,160(19-20):2061-2064
Diode devices (glass/ITO/polymer/Al) have been fabricated using poly (3-hexylthiophene) (P3HT) crosslinked with two different biaryl crosslinkers. Crosslinking was performed by exposing the thin films with different wt% of crosslinker to UV irradiation and progress of crosslinking was monitored by IR spectroscopy. An increase in hole mobility of two orders of magnitude has been observed after crosslinking. 相似文献
66.
PL Grimaldi 《Canadian Metallurgical Quarterly》1996,27(3):24, 26-24, 27
Many employers are contracting mental or behavioral health services separately from other types of health care. Capitation rates are paid for a defined set of benefits. Mental health services are capitated in two ways; both approaches are discussed. 相似文献
67.
Serotonin (5-hydroxytryptamine; 5-HT) elicits external carotid vasoconstriction in vagosympathectomized dogs via 5-HT1B/1D receptors and a mechanism unrelated to the 5-HT1, 5-HT2, 5-HT3 and 5-HT4 types. In order to further explore the nature of this novel mechanism, the canine external carotid effects of 2-(2-aminoethyl)-quinoline (D-1997), a novel 5-HT1 receptor agonist, were analyzed and compared with those of 5-HT and sumatriptan. Intracarotid (i.c.) infusions of 5-HT, D-1997 and sumatriptan to vagosympathectomized dogs dose-dependently decreased external carotid conductance, the rank order of agonist potency being 5-HT > sumatriptan > D-1997. The effects to D-1997 were resistant to intravenous (i.v.) pretreatment with 5-HT2 and 5-HT3/5-HT4 receptor antagonists. Remarkably, the effects induced by lower (10-100 microg/min), but not higher (300-1000 microg/min), doses of D-1997 were blocked by high doses of methiothepin (1 and 3 mg/kg, i.v.), as previously shown with 5-HT. In addition, GR-127935 (1-10 microg/kg, i.v.), partially and dose-dependently antagonized D-1997-induced responses. However, the effects of D-1997 remained unaltered after blockade of alpha- and beta-adrenoceptors, muscarinic, nicotinic, histamine and dopamine receptors, or inhibition of 5-HT-uptake or cyclo-oxygenase, depletion of biogenic amines or blockade of Ca2+ channels. These results may support our previous contention that lower doses of 5-HT elicit external carotid vasoconstriction in vagosympathectomized dogs by activation of 5-HT1B/1D receptors, whilst higher doses of 5-HT stimulate a novel vasoconstrictor mechanism. 相似文献
68.
The specific recognition by Escherichia coli RNA polymerase of single-stranded oligodeoxyribonucleotides (oligos) with the sequence of the -10 promoter region on the nontemplate strand has been studied. Binding was monitored by observing the increase in fluorescence of 2-aminopurine residues incorporated in the oligos. The effects of salt on the rates of formation and dissociation of RNA polymerase.oligo complexes are relatively small, from which we conclude that electrostatic interactions contribute minimally to the favorable binding free energy. From the convex temperature dependence of ln Ka (Ka is the equilibrium association constant), we infer that a large apparent negative heat capacity, of 1-2 kcal M-1 K-1, accompanies complex formation, which is interpreted as due to a conformational change in RNA polymerase. Contrary to expectation, the forward rate constant for binding of oligos is more than 10-fold smaller than that for open complex formation at strong promoters. This suggests that in comparison to an oligo, promoter DNA may be better able to accelerate this required conformational change in the RNA polymerase. Oligo binding was shown to compete with the interaction between RNA polymerase and promoters, indicating that the two bind to overlapping sites on the RNA polymerase 相似文献
69.
For ultrasonographic B-scan images collected by means of a handheld transducer moving in the elevational direction, frame spacings are computed with a speckle-decorrelation algorithm, without additional positioning hardware. Fully developed speckle volumes are automatically segmented and spacing computed from the decorrelation curves. Position accuracy is within 10% for phantoms and 15% for breast studies. The algorithm provides image-based registration, which allows accurate three-dimensional volume rendering. 相似文献
70.