Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 38
Filter
1.
Clín. investig. ginecol. obstet. (Ed. impr.) ; 50(3): [100878], Jul-Sep. 2023. tab, ilus
Article in English | IBECS | ID: ibc-223308

ABSTRACT

Background: Ovarian cancer is the fifth deadliest cancer among women. There is no effective screening method. It has been suggested that ovarian cancer originates from precursor lesions in the fimbriae of the fallopian tubes. Objective: The aim of this study was to determine the level of knowledge of opportunistic bilateral salpingectomy by gynecologists. Methods: A cross-sectional study was carried out and a survey was sent electronically to gynecologists and gynecology residents. Demographic characteristics as well as questions of interest related to clinical practice and indication for surgery were included. Results: 52 subjects were included, 21 women and 31 men, with a mean age of 40.7 years. Thirty-five board certified gynecologists, as well as 17 gynecology residents, were included as part of the total survey group. Thirty-six individuals (69.2%) reported performing elective salpingectomy. The motivation they had to perform salpingectomy as a method of sterilization was: “reduction in the risk of ovarian cancer in the future” (55.6%). The indication for elective salpingectomy while performing other procedures was: “to prevent ovarian cancer” (61.1%). Certified gynecologists (42.9%) as well as residents (41.1%) considered “transvaginal ultrasound screening” as the best primary prevention method for ovarian cancer in low-risk women. Conclusions: Opportunistic bilateral salpingectomy is safe and cost-effective. However, when gynecologists are interviewed to find out their level of knowledge, there is poor acceptance of opportunistic bilateral salpingectomy in Mexico. A training strategy should be designed in the gynecology residency in order to motivate ovarian cancer prevention.(AU)


Antecedentes: El cáncer de ovario es el quinto cáncer más mortal entre las mujeres. No existe un método de detección eficaz. Se ha sugerido que el cáncer de ovario se origina a partir de lesiones precursoras en las fimbrias de las trompas de Falopio. Objetivo: Determinar el nivel de conocimiento de los ginecólogos sobre la salpingectomía bilateral oportunista. Métodos: Se envió una encuesta por vía electrónica a médicos ginecólogos y residentes de Ginecología. Se incluyeron características demográficas, así como preguntas de interés relacionadas con la práctica clínica y la indicación de cirugía. Resultados: Se incluyeron 52 sujetos, 21 mujeres y 31 hombres, con una edad media de 40,7 años. Treinta y cinco ginecólogos certificados, así como 17 residentes de ginecología, se incluyeron como parte del grupo total. Treinta y seis individuos (69,2%) informaron haber realizado salpingectomía electiva. La motivación que tuvieron para realizar la salpingectomía como método de esterilización fue: «reducción del riesgo de cáncer de ovario en el futuro» (55,6%). La indicación de salpingectomía electiva mientras se realizaban otros procedimientos fue: «para prevenir el cáncer de ovario» (61,1%). Los ginecólogos certificados (42,9%) y los residentes (41,1%) consideraron la «detección con ultrasonido transvaginal» como el mejor método de prevención primaria para el cáncer de ovario en mujeres de bajo riesgo. Conclusiones: Cuando entrevistamos a los ginecólogos detectamos poca aceptación de la salpingectomía bilateral oportunista en México. Se debe diseñar una estrategia de formación en la residencia de Ginecología para motivar la prevención del cáncer de ovario.(AU)


Subject(s)
Humans , Female , Salpingectomy , Internship and Residency , Ovarian Neoplasms , Genital Neoplasms, Female , Knowledge , Education, Medical , Mexico , Gynecology , Obstetrics and Gynecology Department, Hospital
2.
Int. j. morphol ; 37(4): 1203-1209, Dec. 2019. graf
Article in English | LILACS | ID: biblio-1040112

ABSTRACT

In vitro modeling of neurodegenerative diseases is now possible by using patient-derived induced pluripotent stem cells (iPS). Through them, it is nowadays conceivable to obtain human neurons and glia, and study diseases cellular and molecular mechanisms, an attribute that was previously unavailable to any human condition. Amyotrophic lateral sclerosis (ALS) is one of the diseases that has gained a rapid advance with iPS technology. By differentiating motor neurons from iPS cells of ALS- patients, we are studying the mechanisms underlying ALS- disease onset and progression. Here, we introduce a cellular platform to help maintain longevity of ALS iPS-motor neurons, a cellular feature relevant for most late-onset human diseases. Long term cultures of patient-derived iPS cells might prove to be critical for the development of personalized-drugs.


Actualmente es posible modelar in vitro enfermedades neurodegenerativas humanas mediante el uso de células madre pluripotentes inducidas (iPS) derivadas del paciente. A través de ellas, es hoy concebible obtener neuronas y glía humanas, y estudiar mecanismos celulares y moleculares de enfermedades, un atributo que anteriormente no era posible para ninguna condición humana. La esclerosis lateral amiotrófica (ELA) es una de las enfermedades que se ha beneficiado con la tecnología de iPS. Al diferenciar neuronas motoras de células iPS obtenidas de pacientes con ELA, hemos iniciado estudios sobre los mecanismos que subyacen a la aparición y progresión de la enfermedad. Aquí, presentamos el desarrollo de una plataforma celular que permite extender la longevidad de las neuronas motoras derivadas de iPS, una característica relevante para la mayoría de las enfermedades humanas de inicio tardío. Los cultivos a largo plazo de células iPS provenientes de pacientes pueden ser determinantes en el desarrollo de terapias asociadas a la medicina de precisión.


Subject(s)
Humans , Animals , Mice , Induced Pluripotent Stem Cells/cytology , Amyotrophic Lateral Sclerosis/metabolism , Immunohistochemistry , Cell Line , Coculture Techniques , Amyotrophic Lateral Sclerosis/pathology , Amyotrophic Lateral Sclerosis/therapy
4.
Plant Dis ; 101(8): 1362-1372, 2017 Aug.
Article in English | MEDLINE | ID: mdl-30678602

ABSTRACT

Isolation and characterization of common scab (CS) pathogen Streptomyces spp. from Uruguayan potato tubers and soil samples were done in response to significant economic losses due to CS on potato in autumn 2010. Seventy of the 331 isolates were classified as pathogenic owing to their ability to induce necrosis on tuber disks and stunting of radish seedling. Streptomyces spp. causing CS on potato in Uruguay were found to represent a range of different species by virtue of their diverse morphological and physiological traits as well as rep-PCR, rpoB phylogenetic analysis, and multi-locus sequences analysis. We identified isolates primarily as Streptomyces scabiei, S. acidiscabies, and S. europaeiscabiei. However, some of the pathogenic isolates still remain to be identified at the species level. This highlights the need for improved methods for discrimination among pathogenic Streptomyces species. The presence of Streptomyces pathogenicity island (PAI) genes was analyzed, including genes encoding for thaxtomin synthetase (txtA, txtB), tomatinase (tomA), and a necrosis protein (nec1). Among the isolates that were pathogenic, 50% contained the four pathogenicity genes, 33% had an atypical composition of PAI marker genes, and 17% did not contain any genes. The absence of the genes reported to be involved in thaxtomin biosynthesis (txtA, txtB) was confirmed by whole-genome sequencing of two representative strains of this group. This finding suggests the participation of other virulence factors in plant pathogenicity.


Subject(s)
Solanum tuberosum , Streptomyces , Genes, Fungal/genetics , Phylogeny , Plant Diseases , Polymerase Chain Reaction , Solanum tuberosum/microbiology , Streptomyces/classification , Streptomyces/genetics , Streptomyces/metabolism , Uruguay , Virulence Factors/genetics
5.
Genome Announc ; 4(1)2016 Feb 11.
Article in English | MEDLINE | ID: mdl-26868406

ABSTRACT

Xanthomonas oryzae pv. oryzae is the etiological agent of bacterial rice blight. Three distinct clades of X. oryzae pv. oryzae are known. We present the complete annotated genome of the African clade strain AXO194 using long-read single-molecule PacBio sequencing technology. The genome comprises a single chromosome of 4,674,975 bp and encodes for nine transcriptional activator-like (TAL) effectors. The approach and data presented in this announcement provide information for complex bacterial genome organization and the discovery of new virulence effectors, and they facilitate target characterization of TAL effectors.

6.
Gene ; 573(1): 115-22, 2015 Nov 15.
Article in English | MEDLINE | ID: mdl-26187068

ABSTRACT

The key protein in the canonical Wnt pathway is ß-catenin, which is phosphorylated both in absence and presence of Wnt signals by different kinases. Upon activation in the cytoplasm, ß-catenin can enter into the nucleus to transactivate target gene expression, many of which are cancer-related genes. The mechanism governing ß-catenin's nucleocytoplasmic transport has been recently unvealed, although phosphorylation at its C-terminal end and its functional consequences are not completely understood. Serine 646 of ß-catenin is a putative CK2 phosphorylation site and lies in a region which has been proposed to be important for its nucleocytoplasmic transport and transactivation activity. This residue was mutated to aspartic acid mimicking CK2-phosphorylation and its effects on ß-catenin activity as well as localization were explored. ß-Catenin S6464D did not show significant differences in both transcriptional activity and nuclear localization compared to the wild-type form, but displayed a characteristic granular nuclear pattern. Three-dimensional models of nuclei were constructed which showed differences in number and volume of granules, being those from ß-catenin S646D more and smaller than the wild-type form. FRAP microscopy was used to compare nuclear export of both proteins which showed a slightly higher but not significant retention of ß-catenin S646D. Altogether, these results show that C-terminal phosphorylation of ß-catenin seems to be related with its nucleocytoplasmic transport but not transactivation activity.


Subject(s)
Active Transport, Cell Nucleus , Transcriptional Activation , beta Catenin/metabolism , Amino Acid Sequence , Animals , Humans , Molecular Sequence Data , Phosphorylation , Sequence Homology, Amino Acid , beta Catenin/chemistry
7.
Neuroscience ; 145(2): 484-94, 2007 Mar 16.
Article in English | MEDLINE | ID: mdl-17306467

ABSTRACT

Brain-derived neurotrophic factor (BDNF) effects on the establishment of glycinergic and GABAergic transmissions in mouse spinal neurons were examined using combined electrophysiological and calcium imaging techniques. BDNF (10 ng/ml) caused a significant acceleration in the onset of synaptogenesis without large effects on the survival of these neurons. Amplitude and frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) and miniature inhibitory postsynaptic currents (mIPSCs) associated to activation of glycine and GABA(A) receptors were augmented in neurons cultured with BDNF. The neurotrophin effect was blocked by long term tetrodotoxin (TTX) addition suggesting a dependence on neuronal activity. In addition, BDNF caused a significant increase in glycine- and GABA-evoked current densities that partly explains the increase in synaptic transmission. Presynaptic mechanisms were also involved in BDNF effects since triethylammonium(propyl)-4-(2-(4-dibutylamino-phenyl)vinyl)pyridinium (FM1-43) destaining with high K(+) was augmented in neurons incubated with the neurotrophin. The effects of BDNF were mediated by receptor tyrosine kinase B (TrkB) and mitogen-activated protein kinase kinase (MEK) activation since culturing neurons with either (9S,10R,12R)-2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-9,12-epoxy-1H-diindolo[1,2,3-fg:3',2',1'- kl]pyrrolo[3,4-i][1,6]benzodiazocine-10-carboxylic acid methyl ester (K252a) or 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one (PD98059) blocked the augmentation in synaptic activity induced by the neurotrophin.


Subject(s)
Brain-Derived Neurotrophic Factor/metabolism , Glycine/metabolism , Neural Pathways/embryology , Neurons/metabolism , Synapses/ultrastructure , gamma-Aminobutyric Acid/metabolism , Animals , Brain-Derived Neurotrophic Factor/pharmacology , Cell Differentiation/drug effects , Cell Differentiation/physiology , Cells, Cultured , Enzyme Inhibitors/pharmacology , Inhibitory Postsynaptic Potentials/drug effects , Inhibitory Postsynaptic Potentials/physiology , MAP Kinase Kinase 1/antagonists & inhibitors , MAP Kinase Kinase 1/metabolism , Mice , Mice, Inbred C57BL , Neural Inhibition/drug effects , Neural Inhibition/physiology , Neural Pathways/drug effects , Neural Pathways/metabolism , Neuronal Plasticity/drug effects , Neuronal Plasticity/physiology , Neurons/ultrastructure , Pyridinium Compounds , Quaternary Ammonium Compounds , Receptor, trkB/drug effects , Receptor, trkB/metabolism , Receptors, GABA-A/drug effects , Receptors, GABA-A/metabolism , Receptors, Glycine/drug effects , Receptors, Glycine/metabolism , Sodium Channel Blockers/pharmacology , Spinal Cord/cytology , Spinal Cord/drug effects , Spinal Cord/embryology , Synapses/drug effects , Synapses/metabolism , Synaptic Transmission/drug effects , Synaptic Transmission/physiology
8.
J Neurochem ; 100(5): 1143-54, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17217420

ABSTRACT

In this study, we describe a novel form of anti-homeostatic plasticity produced after culturing spinal neurons with strychnine, but not bicuculline or 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Strychnine caused a large increase in network excitability, detected as spontaneous synaptic currents and calcium transients. The calcium transients were associated with action potential firing and activation of gamma-aminobutyric acid (GABA(A)) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors as they were blocked by tetrodotoxin (TTX), bicuculline, and CNQX. After chronic blockade of glycine receptors (GlyRs), the frequency of synaptic transmission showed a significant enhancement demonstrating the phenomenon of anti-homeostatic plasticity. Spontaneous inhibitory glycinergic currents in treated cells showed a fourfold increase in frequency (from 0.55 to 2.4 Hz) and a 184% increase in average peak amplitude compared with control. Furthermore, the augmentation in excitability accelerated the decay time constant of miniature inhibitory post-synaptic currents. Strychnine caused an increase in GlyR current density, without changes in the apparent affinity. These findings support the idea of a post-synaptic action that partly explains the increase in synaptic transmission. This phenomenon of synaptic plasticity was blocked by TTX, an antibody against brain-derived neurotrophic factor (BDNF) and K252a suggesting the involvement of the neuronal activity-dependent BDNF-TrkB signaling pathway. These results show that the properties of GlyRs are regulated by the degree of neuronal activity in the developing network.


Subject(s)
Neuronal Plasticity , Neurons/drug effects , Receptors, Glycine/physiology , Strychnine/pharmacology , Synapses/drug effects , 6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology , Action Potentials , Animals , Bicuculline/pharmacology , Brain-Derived Neurotrophic Factor/physiology , Calcium/physiology , Cells, Cultured , Homeostasis , Mice , Mice, Inbred C57BL , Neurons/physiology , Receptor, trkB/physiology , Receptors, Glycine/antagonists & inhibitors , Spinal Cord/cytology , Synapses/physiology , Synaptic Transmission
9.
Proc Natl Acad Sci U S A ; 103(41): 15079-84, 2006 Oct 10.
Article in English | MEDLINE | ID: mdl-17005722

ABSTRACT

Increased expression of casein kinase 2 (CK2) is associated with hyperproliferation and suppression of apoptosis in cancer. Mutations in the tumor suppressor APC (adenomatous polyposis coli) are frequent in colon cancer and often augment beta-catenin-T cell factor (Tcf)/lymphoid enhancer binding factor (Lef)-dependent transcription of genes such as c-myc and cyclin-D1. CK2 has also been implicated recently in the regulation of beta-catenin stability. To identify mechanisms by which CK2 promotes survival, effects of the specific CK2 inhibitors 4,5,6,7-tetrabromobenzotriazole (TBB) and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole were assessed. TBB and 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole significantly decreased proliferation and increased apoptosis of HT29(US) colon cancer cells. RT-PCR and immunoblot analysis revealed that both inhibitors decreased survivin mRNA and protein levels in HT29(US) cells. Similar effects were observed with TBB in human DLD-1 and SW-480 colorectal cells as well as ZR-75 breast cancer cells and HEK-293T embryonic kidney cells. Expression of GFP-CK2alpha in HEK-293T cells resulted in beta-catenin-Tcf/Lef-dependent up-regulation of survivin and increased resistance to anticancer drugs. Augmented beta-catenin-Tcf/Lef-dependent transcription and resistance to apoptosis observed upon GFP-CK2alpha expression were abolished by TBB. Alternatively, HEK-293T cells expressing GFP-survivin were resistant to TBB-induced apoptosis. Finally, siRNA-mediated down-regulation of CK2alpha in HEK-293T cells coincided with reduced beta-catenin and survivin levels. Taken together, these results suggest that CK2 kinase activity promotes survival by increasing survivin expression via beta-catenin-Tcf/Lef-mediated transcription. Hence, selective CK2 inhibition or down-regulation in tumors may provide an attractive opportunity for the development of novel cancer therapies.


Subject(s)
Casein Kinase II/physiology , Lymphoid Enhancer-Binding Factor 1/physiology , Microtubule-Associated Proteins/biosynthesis , Microtubule-Associated Proteins/genetics , Neoplasm Proteins/biosynthesis , Neoplasm Proteins/genetics , TCF Transcription Factors/physiology , Transcription, Genetic/physiology , beta Catenin/physiology , Casein Kinase II/antagonists & inhibitors , Cell Line , HT29 Cells , Humans , Inhibitor of Apoptosis Proteins , Survivin , Transcription, Genetic/drug effects , Triazoles/pharmacology , Up-Regulation/drug effects , Up-Regulation/genetics
10.
Neuroscience ; 108(3): 493-506, 2001.
Article in English | MEDLINE | ID: mdl-11738262

ABSTRACT

Using fluorometric and immunocytochemical techniques, we found that high glycine concentrations or blockade of glycine receptors increases neurite outgrowth in developing mouse spinal cord neurons. Glycine- and GABA(A)-activated currents were demonstrated during applications of glycine and GABA (50-100 microM) in 5 days in vitro (DIV) neurons. Long application (> or =10 min) of 100 microM glycine desensitized the membrane response by more than 95%. Application of glutamate in the absence of external Mg(2+), at several membrane potentials, did not produce any detectable membrane response in these cells. Immunocytochemical studies with NR1 and GluR1 antibodies showed a delayed appearance of N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors respectively. Spontaneous synaptic activity was readily observed in 5 DIV neurons. The use of various receptor antagonists (strychnine, bicuculline, DL-2-amino-5-phosphonovalerate [APV], 6-cyano-7-nitroquinoxaline-2,3-dione [CNQX]) revealed that this activity was predominantly glycinergic, and to a smaller extent, GABAergic. In the presence of bicuculline, APV and CNQX, we detected abundant spontaneous depolarizing potentials which often reached the action potential threshold. Further evidence for functional synaptic activity was provided by the detection of co-localization of gephyrin and synaptophysin at 5 DIV using confocal microscopy. Fluorometric studies with Fluo-3, a Ca(2+) indicator, in 5 DIV cultures showed the presence of spontaneous fluctuations associated with tetrodotoxin-sensitive synaptic events. The number of neurons displaying these fluctuations was significantly increased (>100%) when the cells were bathed in a strychnine-containing solution. On the other hand, these synaptically mediated Ca(2+) events were blocked by the co-application of strychnine and bicuculline. This suggests that glycine and GABA(A) receptors provide a fundamental regulation of both neuronal excitability and intracellular Ca(2+) at this early time of development.The neurotrophic effects of agonists and antagonists for glycine, GABA(A) and glutamate receptors were examined in neurons cultured for 2 or 5 DIV. From all the agonists used, only high concentrations of glycine increased neurite outgrowth in 5 DIV neurons. We found that strychnine also increased neurite outgrowth, whereas tetrodotoxin (1 microM), nimodipine (4 microM) and bicuculline (20 microM) completely blocked it. On the other hand, APV (50 microM) and CNQX (20 microM) were unable to affect neurite outgrowth. These data suggest that spinal glycine receptors depress neurite outgrowth by shunting neuronal excitability. Outgrowth induction possibly results from the enhanced activity found after the inhibition of glycinergic activity. We postulate that this resets the intracellular calcium at a concentration that favors neurite outgrowth.


Subject(s)
Neurites/physiology , Neurons/physiology , Receptors, GABA-A/physiology , Receptors, Glycine/physiology , Spinal Cord/physiology , Animals , Calcium/metabolism , Embryo, Mammalian , Extracellular Space/metabolism , Glutamic Acid/metabolism , Glycine/pharmacology , Ligands , Mice , Mice, Inbred C57BL , Neurons/metabolism , Receptors, GABA-A/metabolism , Receptors, Glycine/metabolism , Spinal Cord/cytology , Spinal Cord/metabolism , Synapses/physiology , Time Factors , gamma-Aminobutyric Acid/metabolism
11.
J Cell Biochem ; 80(4): 491-503, 2001.
Article in English | MEDLINE | ID: mdl-11169733

ABSTRACT

Glucose transporters play an essential role in the acquisition of glucose by the brain. Elevated expression of glucose transporter-1 has been detected in endothelial cells of the blood-brain barrier and in choroid plexus cells of the blood-cerebrospinal fluid barrier. On the other hand, there is a paucity of information on the expression of glucose transporters in the ependymal cells that line the walls of the cerebral ventricles. The tanycytes are specialized ependymal cells localized in circumventricular organs such as the median eminence that can be segregated into at least three types, alpha, beta1 and beta2. The beta2 tanycytes form tight junctions and participate in the formation of the cerebrospinal fluid-median eminence barrier. Using immunocytochemistry and in situ hybridization, we analyzed the expression of hexose transporters in rat and mouse hypothalamic tanycytes. In both species, immunocytochemical analysis revealed elevated expression of glucose transporter-1 in alpha and beta1 tanycytes. Intense anti-glucose transporter-1 staining was observed in cell processes located throughout the arcuate nucleus, in the end-feet reaching the lateral sulcus of the infundibular region, and in cell processes contacting the hypothalamic capillaries. On the other hand, there was very low expression of glucose transporter-1 in beta2 tanycytes involved in barrier function. In contrast with the results of the cytochemical analysis, in situ hybridization revealed that tanycytes alpha, beta1, and beta2 express similar levels of glucose transporter-1 mRNA. Further analysis using anti-glial fibrillary acidic protein antibodies to identify areas rich in astrocytes revealed that astrocytes were absent from areas containing alpha and beta1 tanycytes, but were abundant in regions containing the barrier-forming beta2 tanycytes. Overall, our data reveal a lack of correlation between participation in barrier function and expression of glucose transporter-1 in hypothalamic tanycytes. Given the virtual absence of astrocytes in areas rich in alpha and beta1 tanycytes, we speculate whether the tanycytes might have astrocyte-like functions and participate in the metabolic coupling between glia and neurons in the hypothalamic area.


Subject(s)
Blood-Brain Barrier/physiology , Brain/metabolism , Cerebrospinal Fluid/metabolism , Ependyma/cytology , Hypothalamus/cytology , Hypothalamus/metabolism , Monosaccharide Transport Proteins/biosynthesis , Up-Regulation , Animals , Astrocytes/metabolism , Cell Nucleus/metabolism , Glial Fibrillary Acidic Protein/biosynthesis , Glucose Transporter Type 1 , Immunohistochemistry , In Situ Hybridization , Mice , Mice, Inbred C57BL , Models, Biological , Neuroglia/metabolism , Neurons/metabolism , RNA, Messenger/metabolism , Rats
12.
Neuroreport ; 11(13): 3007-10, 2000 Sep 11.
Article in English | MEDLINE | ID: mdl-11006984

ABSTRACT

The effect of glycine receptor activation on neurite outgrowth and survival was studied in 5 DIV (days in vitro) spinal neurons. These neurons were depolarized by spontaneous synaptic activity and by glycine, but not by glutamate. These responses were accompanied by increases in intracellular calcium concentration measured with Indo-1 and Fluo-3. Glycine (100 microM, 48 h) increased (46 +/- 6%) the number of primary neurites and total neuritic length. This effect was mediated by synaptic activity and calcium influx because TTX (1 microM) and nimodipine (4 microM) blocked the stimulatory effect of glycine. Neuronal survival, on the other hand, was not affected. This study shows for the first time the modulatory effect of glycine receptors on spinal neuron development.


Subject(s)
Nerve Growth Factors/metabolism , Neurites/metabolism , Neurons/metabolism , Receptors, Glycine/metabolism , Spinal Cord/metabolism , Animals , Calcium/metabolism , Cell Differentiation/physiology , Cells, Cultured , Fetus , Glycine/metabolism , Glycine/pharmacology , Mice , Mice, Inbred C57BL , Neurons/cytology , Receptors, Glycine/drug effects , Spinal Cord/cytology
13.
Eur J Pharmacol ; 354(2-3): 239-44, 1998 Aug 07.
Article in English | MEDLINE | ID: mdl-9754925

ABSTRACT

Using patch-clamp and fluorescence techniques we found that ethanol (10-200 mM) potentiated strychnine-sensitive glycine receptors without having detectable effects on lipid order parameters in mouse spinal cord neurons. Hepthanol (0.01-1 mM), in contrast, did not affect the glycine current, but it altered the core and surface of spinal neuron membranes as detected by changes in 1,6-diphenyl-1,3,5-hexatriene (DPH) and Laurdan fluorescence parameters. These findings support the idea that ethanol affects these membrane proteins without changing lipid fluidity.


Subject(s)
Ethanol/pharmacology , Membrane Lipids/metabolism , Neurons/drug effects , Receptors, Glycine/drug effects , Animals , Cells, Cultured , Chloride Channels/drug effects , Chloride Channels/physiology , Female , Glycine/metabolism , Membrane Fluidity , Mice , Mice, Inbred C57BL , Neurons/physiology , Receptors, Glycine/physiology , Spinal Cord/drug effects , Spinal Cord/physiology
14.
Synapse ; 28(3): 185-94, 1998 Mar.
Article in English | MEDLINE | ID: mdl-9488503

ABSTRACT

We studied several neurophysiological properties of in vitro maturing glycine receptors in mouse spinal cord neurons cultured for various times: 3-7 days (early), 10-12 days (intermediate), and 17-24 days (mature), using whole-cell and gramicidin-perforated techniques. The glycine-activated Cl- conductance increased about 6-fold during in vitro development, and the current density increased from 177+/-42 pA/pF in early to 504+/-74 pA/pF in mature neurons. The sensitivity to glycine increased transiently from 39+/-2.8 microM in early neurons to 29+/-1 microM in intermediate neurons. Using whole-cell recordings, we found that ECl did not change during development. With the gramicidin-perforated technique, on the other hand, ECl shifted from -27 to -52 mV with development. Thus, immature neurons were depolarized by the activation of glycine receptors, whereas mature neurons were hyperpolarized. The current decayed (desensitized) during the application of 500 microM glycine. The decay was single exponential and the time constant increased from 2,212+/-139 msec in early neurons to 4,580+/-1,071 msec in mature neurons. Picrotoxin (10 microM) inhibited the current to a larger extent in early neurons (46+/-6% of control), and the sensitivity of these receptors to strychnine (IC50) increased from 23+/-3 nM to 9+/-1 nM in mature neurons. In conclusion, several properties of spinal glycine receptors changed during in vitro neuronal maturation. This indicates that, similar to GABA(A) receptors, the functions of these receptors are developmentally regulated. These changes should affect the excitability of spinal neurons as well as other maturation processes.


Subject(s)
Neurons/physiology , Receptors, Glycine/physiology , Spinal Cord/cytology , Animals , Cells, Cultured , Central Nervous System Depressants/pharmacology , Chlorides/metabolism , Ethanol/pharmacology , Female , GABA Antagonists/pharmacology , Glycine/pharmacology , Glycine Agents/pharmacology , Membrane Potentials/drug effects , Mice , Mice, Inbred C57BL , Neurons/chemistry , Neurons/drug effects , Patch-Clamp Techniques , Picrotoxin/pharmacology , Pregnancy , Receptors, Glycine/agonists , Receptors, Glycine/antagonists & inhibitors , Spinal Cord/embryology , Strychnine/pharmacology , Synapses/chemistry , Synapses/drug effects , Synapses/metabolism , Zinc/pharmacology
15.
Brain Res ; 769(2): 203-10, 1997 Sep 26.
Article in English | MEDLINE | ID: mdl-9374187

ABSTRACT

Using patch-clamp techniques we studied several aspects of intracellular GABA(A) and glycine Cl- current regulation in cortical and spinal cord neurons, respectively. Activation of PKA with a permeable analog of cyclic AMP (cAMP) produced a potentiation of the Cl- current activated with glycine, but not of the current induced with GABA. The inactive analog was without effect. Activation of PKC with 1 microM PMA reduced the amplitude of the GABA(A) and glycine currents. Internal application of 1 mM cGMP, on the other hand, had no effect on the amplitude of either current. The amplitude of these inhibitory currents changed slightly during 20 min of patch-clamp recording. Internal perfusion of the neurons with 1 microM okadaic acid, a phosphatase inhibitor, induced potentiation in both currents. The amplitude of GABA(A) and glycine currents recorded with 1 mM internal CaCl2 and 10 mM EGTA (10 nM free Ca2+) decayed by less than 30% of control. Increasing the CaCl2 concentration to 10 mM (34 microM free Ca2+) induced a transient potentiation of the GABA(A) current. A strong depression of current amplitude was found with longer times of dialysis. The glycine current, on the contrary, was unchanged by increasing the intracellular Ca2+ concentration. Activation of G proteins with internal FAl4- induced an inhibition of the GABA(A) current, but potentiated the amplitude of the strychnine-sensitive Cl- current. These results indicate that GABA(A) and glycine receptors are differentially regulated by activation of protein kinases, G proteins and Ca2+. This conclusion supports the existence of selectivity in the intracellular regulation of these two receptor types.


Subject(s)
Cerebral Cortex/metabolism , Intracellular Membranes/physiology , Neurons/metabolism , Receptors, GABA-A/metabolism , Receptors, Glycine/metabolism , Spinal Cord/metabolism , Aluminum Compounds/pharmacology , Animals , Calcium/physiology , Cells, Cultured , Cyclic AMP/analogs & derivatives , Electric Conductivity , Fluorides/pharmacology , Mice/embryology , Mice, Inbred C57BL , Neurons/physiology , Okadaic Acid/pharmacology , Receptors, GABA-A/drug effects , Receptors, GABA-A/physiology , Receptors, Glycine/drug effects , Receptors, Glycine/physiology , Spinal Cord/cytology , Tetradecanoylphorbol Acetate/pharmacology
16.
J Pharmacol Exp Ther ; 279(3): 1116-22, 1996 Dec.
Article in English | MEDLINE | ID: mdl-8968332

ABSTRACT

Ethanol (1-200 mM), a potent depressor of respiration and motor activity, potentiated the inhibitory Cl- current activated by glycine in 80% of the cultured mouse spinal (n = 236) neurons studied. Ethanol (100 mM) had no effect on the gamma-aminobutyric acidA current and slightly inhibited the N-methyl-D-aspartate current in these neurons. Ethanol increased the affinity of the receptors to glycine without changing the maximal amplitude of the glycine current. The EC50 was reduced from 54 +/- 3 microM in the absence of ethanol to 38 +/- 5 microM in the presence of ethanol. Activation of GTP binding proteins in the neurons with intracellular guanosine-5'-0-(2-thiotriiphosphate) (0.5 mM) enhanced the effect of ethanol, and application of a similar concentration of guanosine 5'-0-(2-thiodiphosphate had an inhibitory effect upon the current potentiation. The potentiating effect of ethanol persisted after culturing the neurons with pertussis toxin, but not with cholera toxin, an irreversible activator of Gs. Activation of cyclic AMP-dependent protein kinase by cyclic AMP and Sp-adenosine-3',5'-cyclic monophosphothioate triethylamine salt, but not of protein kinase C and protein kinase G, potentiated the glycine current. The effect of Sp-adenosine-3',5'-cyclic monophosphothioate triethylamine salt, but not of ethanol, was inhibited completely by the protein kinase A peptide inhibitor. These results suggest that ethanol potentiates the glycine activated Cl- current by modifying a signal transduction step other than protein kinase A.


Subject(s)
Chloride Channels/drug effects , Ethanol/pharmacology , Glycine/pharmacology , Neurons/drug effects , Spinal Cord/drug effects , Animals , Cholera Toxin/pharmacology , Drug Synergism , Enzyme Activation , Enzyme Inhibitors/pharmacology , Guanosine 5'-O-(3-Thiotriphosphate)/analogs & derivatives , Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology , Mice , Mice, Inbred C57BL , N-Methylaspartate/metabolism , Neurons/metabolism , Pertussis Toxin , Protein Kinase Inhibitors , Protein Kinases/metabolism , Spinal Cord/cytology , Spinal Cord/metabolism , Virulence Factors, Bordetella/pharmacology , gamma-Aminobutyric Acid/metabolism
17.
Rev Med Chil ; 124(9): 1036-44, 1996 Sep.
Article in Spanish | MEDLINE | ID: mdl-9197016

ABSTRACT

BACKGROUND: Microalbuminuria in diabetic patients is diagnostic of early renal involvement and angiotensin converting enzyme inhibitors reduce albumin excretion in these subjects. AIM: To assess the effects of an angiotensin converting enzyme inhibitor on urinary albumin excretion in non insulin dependent diabetic patients. PATIENTS AND METHODS: Diabetic patients with normal blood pressure were randomly assigned to receive enalapril 10 mg/day or placebo and followed during 18 months. Those with high blood pressure were randomly assigned to receive enalapril or acebutolol in doses necessary to normalize blood pressure and followed during 12 months. Every three months, urinary albumin excretion was measured in a four hour urine sample by radioimmunoassay. RESULTS: One hundred fifty two patients were recruited for the study and 46 were lost from follow up. In 17 subjects with normal blood pressure initial urinary albumin excretion below cutoff values (30 mg/24 h) and treated with enalapril, this parameter did not change; in 20 treated with placebo, it increased from 5.8 +/- 6.1 to 18.2 +/- 7.5 mg/24 h. In 11 patients with normal pressure and increased initial urinary albumin, this parameter did not change with enalapril and increased in 10 with placebo from 87.3 +/- 75.1 to 253.6 +/- 61.1 mg/24 h. In hypertensive patients with normal urinary albumin excretion, no changes in this parameter were observed in those treated with acebutolol (n = 10) or enalapril (n = 14). In hypertensives with high urinary albumin excretion, it decreased from 119.2 +/- 8.5 to 40.0 +/- 4.7 mg/24 h with enalapril treatment (n = 12), and no change was observed in those treated with acebutolol (n = 11). CONCLUSIONS: Enalapril decreases urinary albumin excretion in non insulin dependent diabetic patients.


Subject(s)
Albumins/analysis , Albuminuria/drug therapy , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Diabetes Mellitus, Type 2/urine , Enalapril/therapeutic use , Adult , Aged , Albuminuria/etiology , Albuminuria/urine , Diabetes Mellitus, Type 2/complications , Double-Blind Method , Follow-Up Studies , Humans , Middle Aged
18.
Pharmacology ; 52(6): 371-6, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8844787

ABSTRACT

We studied the effects of diazepam, CL 218,872, Ro 15-1788, beta-CCM and Ro 15-4513 on the gamma-aminobutyric acid-activated current in adult and newborn rat superior cervical ganglion neurons. Diazepam (10-1,000 nmol/l) potentiated the current in a concentration-dependent manner. CL 218,872 was less effective and weaker than diazepam. The other ligands reduced the amplitude of the current. These peripheral receptors might be involved in some of the side effects of benzodiazepines.


Subject(s)
Neurons/drug effects , Receptors, GABA-A/metabolism , Superior Cervical Ganglion/drug effects , Age Factors , Animals , Animals, Newborn , Anti-Anxiety Agents/pharmacology , Diazepam/pharmacology , Electrophysiology , Flumazenil/pharmacology , Ligands , Neurons/metabolism , Neurons/physiology , Pyridazines/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, GABA-A/physiology , Superior Cervical Ganglion/metabolism , gamma-Aminobutyric Acid/pharmacology
19.
Rev Med Chil ; 122(10): 1163-8, 1994 Oct.
Article in Spanish | MEDLINE | ID: mdl-7659883

ABSTRACT

The clinical features and evolution of 40 patients with diabetes mellitus secondary to chronic pancreatitis were reviewed and compared with 40 insulin dependent diabetics, matched for the disease duration. The diagnosis of pancreatitis was confirmed by the existence of pancreatic calcifications, surgery or autopsy and was associated to alcoholism in males and biliary diseases in females. Diabetes appeared, as a mean, 3 years after the diagnosis of pancreatitis. Ninety percent of subjects required insulin and, in males, these requirements were higher than their matched controls. Episodes of ketoacidosis were less frequent than in insulin dependent patients (8 vs 48% p < 0.001) and pulmonary tuberculosis had a higher prevalence (22.5 vs 5% p < 0.01). Nephropathy was observed with equal frequency in both groups but the incidence of retinopathy was higher in postpancreatic diabetics (38 vs 20% p < 0.01). It is concluded that the features of diabetes secondary to chronic pancreatitis are similar to those of insulin dependent diabetes, with some quantitative differences.


Subject(s)
Diabetes Mellitus/etiology , Pancreatitis/complications , Adolescent , Adult , Aged , Aged, 80 and over , Chronic Disease , Female , Humans , Male , Middle Aged
20.
Rev Med Chil ; 119(10): 1140-6, 1991 Oct.
Article in Spanish | MEDLINE | ID: mdl-1845208

ABSTRACT

The efficacy and tolerance of 750 mg of Acipimox was tested in 38 pts with primary dyslipidemias: 20 type IIa, 12 type IIb, and 6 type IV. All pts had been poor responders to a 2 month diet according to the recommendations of the National Cholesterol Education Program. Clinical examination, eye fundus, and the following laboratory tests: total cholesterol (TC), HDL, triglycerides (TG), total bilirubin, alkaline phosphatase, oxalacetic and pyruvic transaminases, uric acid, plasmatic creatinine, albumin, postprandial glucose test, hematocrit, white blood and platelet count were performed 60 days before drug initiation, 60 and 180 days after treatment had been started. No side effects were observed (myositis, visual gastrointestinal). 50% of the pts had slight to moderate flushing which appeared the first 3 days and lasted 14 +/- 7 days after treatment had been started. Plasmatic creatinine increased from 0.89 to 1.86 mg/dl in pt with one kidney, returning to normal levels 30 days after Acipimox interruption. After 180 days of therapy in the IIa group TC was -27% (p < 0.001), HDL + 15% (p < 0.001); in the IIb group: TC-23% (p < 0.001), HDL +9% (NS), TG -48% (p < 0.001); and in the IV group: TC-10% (p < 0.05), HDL +20% (p < 0.001), TG-53% (p < 0.001). Acipimox is well tolerated and is useful as a lipid-lowering drug in type IIa, IIb and IV dyslipidemias. Further studies are necessary to clear effects of the drug on renal metabolism and on long term survival of coronary pts.


Subject(s)
Hyperlipidemias/drug therapy , Hypolipidemic Agents/therapeutic use , Pyrazines/therapeutic use , Adolescent , Adult , Aged , Cholesterol/blood , Female , Humans , Hyperlipidemias/blood , Male , Middle Aged , Triglycerides/blood
SELECTION OF CITATIONS
SEARCH DETAIL
...