Sodium channel beta-subunits modulate channel gating, assembly, and cell surface expression in heterologous cell systems. We generated beta2(-/-) mice to investigate the role of beta2 in control of sodium channel density, localization, and function in neurons in vivo. Measurements of [(3)H]saxitoxin (STX) binding showed a significant reduction in the level of plasma membrane sodium channels in beta2(-/-) neurons.
View Article and Find Full Text PDFModern imaging techniques such as computed tomography (CT) and ultrasound (US) are in the majority of cases able to detect local and metastatic spread of malignancy. Increasingly, the requirement is for even more accurate pre-operative tumour staging to enable the use of new surgical techniques, neo-adjuvant therapies and, postoperatively, to enable detection of tumour recurrence on follow-up. Recent imaging research has focused on magnetic resonance imaging (MRI) for the detection of local tumour extension particularly for rectal tumours and on positron emission tomography (PET) and radioimmunoscintigraphy (RIS) for the detection of metastatic nodal and soft tissue disease.
View Article and Find Full Text PDFThis study investigated the toxicity and efficacy of a 13-cis retinoic acid, carboplatin, and paclitaxel (Taxol) regimen in 18 patients with recurrent or metastatic squamous cell carcinomas (12 head and neck, 4 cervix, 1 esophagus, and 1 anus). Three patients were treated at each dose level with fenretamide (Accutane) 1 mg/kg/d orally for 14 days, carboplatin AUC of 5 mg/ml.min intravenously (IV) and paclitaxel at a dose of 135, 155, 175, 195, 205, or 225 mg/m(2) IV on day 8 every 4 weeks for 6 cycles.
View Article and Find Full Text PDFThrombin appears to underlie myometrial contractions in response to intrauterine bleeding. In a similar fashion, thrombin generated within the uterus in the absence of active bleeding could also produce contractions. These studies sought to determine whether functionally active prothrombin is expressed in the pregnant and nonpregnant rat uterus.
View Article and Find Full Text PDFAm J Obstet Gynecol
November 2001
Objective: The phosphatidylinositol signaling pathway appears to play a significant role in the intracellular events leading to agonist-stimulated phasic myometrial contractions. The studies described in this report were performed to characterize phospholipase C isoform expression at the protein level and to confirm histologic localization of these proteins within the myometrial smooth muscle layers of the uterus.
Methods: For these studies, uterine tissue was obtained from timed- pregnant and spontaneously cycling adult female Sprague-Dawley rats.
The fucose alpha(1-->2) galactose beta structure is expressed by uterine epithelial cells in the mouse and has been implicated in blastocyst adhesion events thought to be required for murine implantation. Fucalpha(1-->2)Galbeta moieties and cognate fucosyltransferases are also expressed by epithelial cells of the male reproductive tract and have been implicated in sperm maturation events that may contribute to fertilization. To determine directly if Fucalpha(1-->2)Galbeta moieties are required for fertility, we have generated strains of mice that are deficient in genes encoding FUT1 and FUT2, a pair of GDP-L-fucose:beta(1-->4)-D-galactosyl-R 2-alpha-L-fucosyltransferase enzymes (EC 2.
View Article and Find Full Text PDFThe protein neural retina leucine zipper (Nrl) is a basic motif-leucine zipper transcription factor that is preferentially expressed in rod photoreceptors. It acts synergistically with Crx to regulate rhodopsin transcription. Missense mutations in human NRL have been associated with autosomal dominant retinitis pigmentosa.
View Article and Find Full Text PDFJ Soc Gynecol Investig
January 2002
Objective: Thrombin generated during the active clotting of blood appears to be a potent uterotonic agonist; however, the mechanism underlying this effect on uterine smooth muscle is not well understood. We performed studies to confirm the uterotonic effects of thrombin and to determine whether prostaglandin production plays a role during the uterotonic effects of thrombin or clotting blood.
Methods: Uterine contraction studies were performed using adult nonpregnant and near-term pregnant rats.
Proc Natl Acad Sci U S A
August 2001
Adenosine is a determinant of metabolic control of organ function increasing oxygen supply through the A2 class of adenosine receptors and reducing oxygen demand through A1 adenosine receptors (A1AR). In the kidney, activation of A1AR in afferent glomerular arterioles has been suggested to contribute to tubuloglomerular feedback (TGF), the vasoconstriction elicited by elevations in [NaCl] in the macula densa region of the nephron. To further elucidate the role of A1AR in TGF, we have generated mice in which the entire A1AR coding sequence was deleted by homologous recombination.
View Article and Find Full Text PDFThe accumulation of unfolded protein in the endoplasmic reticulum (ER) attenuates protein synthesis initiation through phosphorylation of the alpha subunit of eukaryotic translation initiation factor 2 (eIF2alpha) at Ser51. Subsequently, transcription of genes encoding adaptive functions including the glucose-regulated proteins is induced. We show that eIF2alpha phosphorylation is required for translation attenuation, transcriptional induction, and survival in response to ER stress.
View Article and Find Full Text PDFJ Neuroophthalmol
March 2001
Objectives: To investigate the visual outcomes of patients with gliomas of the anterior visual pathway and the clinical features associated with prognosis.
Materials And Methods: During retrospective review, demographic and clinical data were abstracted from medical records of patients seen at the Bascom Palmer Eye Institute between January 1, 1970 and December 31, 1998.
Results: Of the 42 patients identified, 68% were female, and 55% had neurofibromatosis (NF) type I.
This study evaluated whether androgen action is altered in rats treated neonatally with diethylstilbestrol (DES) at a dose that induced reproductive tract abnormalities. Rats were treated on alternate days 2-12 with 10 microg DES and studied on Day 18. DES-induced abnormalities included a 70% reduction in testis weight, distension and overgrowth of the rete, distension and reduction in epithelial height of the efferent ducts, underdevelopment of the epididymal duct epithelium, reduction in epithelial height in the vas deferens, and convolution of the extra-epididymal vas.
View Article and Find Full Text PDFGlomerular epithelial protein 1 (GLEPP1) is a receptor tyrosine phosphatase present on the apical cell surface of the glomerular podocyte. The GLEPP1 gene (PTPRO:) was disrupted at an exon coding for the NH(2)-terminal region by gene targeting in embryonic stem cells. Heterozygote mating produced the expected genotypic ratio of 1:2:1, indicating that the Ptpro(-/-) genotype does not lead to embryonic or neonatal lethality.
View Article and Find Full Text PDFAm J Obstet Gynecol
October 2000
Objective: A previous report from our laboratory demonstrated that thrombin stimulates myometrial contractions by activating the phosphatidylinositol signaling pathway in a dose-dependent fashion. The studies described in this report sought to determine whether thrombin and blood stimulate myometrial contractions both in vivo and in vitro and whether these uterotonic effects could be suppressed or prevented with thrombin inhibitors.
Study Design: In vitro contraction studies were performed with proestrus and estrus rat myometrial tissue.
Am J Obstet Gynecol
September 2000
Objective: The mechanisms underlying the stimulation of uterine contractions in the presence of intrauterine hemorrhage have not been well defined. Thrombin, a blood coagulation factor, activates membrane receptors to result in the stimulation of the phosphatidylinositol signaling pathway and the mobilization of cytosolic calcium in platelets. Our studies sought to determine whether thrombin stimulates similar events in myometrial smooth muscle.
View Article and Find Full Text PDFAm J Public Health
August 2000
Objectives: This report measured the effect of births at 22 weeks' gestation or earlier on infant mortality in Philadelphia, Pa.
Methods: The proportion of live-born deliveries at 22 weeks or earlier was calculated. Overall and race-specific infant mortality was calculated after excluding live-born deliveries at 22 weeks' gestation or earlier.
Objective: The role of diacylglycerol in the phosphatidylinositol-signaling pathway is to activate protein kinase C. In the myometrium, protein kinase C activation leads to inhibition of phasic contractions. These studies are designed to determine why stimulation of the phosphatidylinositol-signaling pathway caused by oxytocin does not cause a paradoxical suppression of contractions through diacylglycerol production and protein kinase C activation.
View Article and Find Full Text PDFJ Soc Gynecol Investig
February 2000
Objective: Activation of the phosphatidylinositol signaling pathway plays a key role during the generation of agonist-stimulated phasic myometrial contractions. Protein kinase C (PKC), a component of this signaling pathway, has been previously shown to produce feedback inhibition of agonist-stimulated myometrial contractions. The studies described in this report were performed to survey the tissue-specific expression of several PKC isoforms in the rat uterus.
View Article and Find Full Text PDFJ Soc Gynecol Investig
December 1999
These studies sought to test the hypothesis that tyrosine kinase-stimulated phasic myometrial contractions are mediated by activation of the phosphatidylinositol (PI)-signaling pathway and the generation of cytosolic calcium oscillations. For these studies, uterine tissue was obtained from adult female Sprague-Dawley white rats during the proestrus/estrus phase of the cycle. In vitro contraction studies were performed using pervanadate (a tyrosine phosphatase inhibitor) with and without inhibitors of the PI-signaling pathway, including 2-nitro-4-carboxyphenyl-N,N-diphenylcarbamate (a phospholipase C inhibitor), thimerosal (an inositol-trisphosphate receptor/channel inhibitor), and Ruthenium red (a ryanodine receptor inhibitor), and with oxytocin or prostaglandin F2 alpha (two classic uterotonic agonists).
View Article and Find Full Text PDFThese studies were performed to evaluate the effect of 2-aminoethoxydiphenyl borate (2-APB), a novel membrane-permeable inositol 1,4,5-trisphosphate-receptor inhibitor on agonist-induced, spontaneous, and KCl-stimulated in vitro myometrial contractions. 2-APB significantly inhibited spontaneous myometrial contractions as well as phasic contractions induced by various uterotonic agonists. Confiriming its effects on intracellular calcium release, 2-APB inhibited phasic contractions in the absence of extracellular calcium.
View Article and Find Full Text PDFIntrauterine gene transfer in mice by intraplacental microinjection of recombinant adenoviral or retroviral vectors carrying beta-galactosidase (beta-gal) reporter gene was analyzed in relation to gestational stage, viral titer and promoters. After injections of viral vectors on days 9.5, 11.
View Article and Find Full Text PDFSynthesis and structure-activity relationships (SAR) of orally active arginine vasopressin (AVP) receptor antagonists are discussed. Potent and orally active AVP receptor antagonists are produced when ring A of VPA-985 (1) is replaced with a 3-pyridinyl unit (2b).
View Article and Find Full Text PDFSynthesis and structure-activity relationships (SAR) of arginine vasopressin receptor (AVP) antagonists are described. Potent and orally active compounds are prepared when tricyclic 10,11-dihydro-5H-pyrrolo[2,1-c][1,4]benzodiazepine moiety in VPA-985 1 is replaced with a compound 7 or 12.
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