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1.
Neoplasma ; 65(1): 66-74, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29322790

RESUMEN

HCC (hepatocellular carcinoma), which can be induced by cirrhosis and viral hepatitis infection, is the most frequent form of liver cancer. This study is performed to investigate the mechanisms of HCC. GSE57957 was obtained from Gene Expression Omnibus database, including 39 HCC samples and 39 adjacent non-tumorous samples. The DEGs (differentially expressed genes) were screened using the limma package in R, and then were conducted with enrichment analysis using "BioCloud" platform. Using STRING database, WebGestalt tool, as well as ITFP and TRANSFAC databases, PPI (protein-protein interaction) pairs, miRNA (microRNA)-target pairs, and TF (transcription factor)-target pairs separately were predicted. Followed by integrated network was constructed by Cytoscape software and module analysis was performed using the MCODE plugin of Cytoscape software. There were 518 DEGs identified from the HCC samples, among which 17 up-regulated genes (including MCM2, MCM6, and CDC20) and 5 down-regulated genes could also function as TFs. In the integrated network for the down-regulated genes, FOS and ESR1 had higher degrees, and both of them were targeted by miR-221 and miR-222. Additionally, MCM2 had interaction with MCM6 in the up-regulated module with the highest score. MCM2, MCM6, CDC20, FOS, ESR1, miR-221 and miR-222 might affect the pathogenesis of HCC.


Asunto(s)
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , MicroARNs/genética , Factores de Transcripción/genética , Perfilación de la Expresión Génica , Redes Reguladoras de Genes , Humanos , Mapas de Interacción de Proteínas
2.
Nanotechnology ; 21(12): 125704, 2010 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-20195018

RESUMEN

This paper investigates the effect of intertube van der Waals interaction on the stability of pristine and covalently functionalized carbon nanotubes under axial compression, using molecular mechanics simulations. After regulating the number of inner layers of the armchair four-walled (5, 5)@(10, 10)@(15, 15)@(20, 20) and zigzag four-walled (6, 0)@(15, 0)@(24, 0)@(33, 0) carbon nanotubes, the critical buckling strains of the corresponding tubes are calculated. The results show that each of the three inner layers in the functionalized armchair nanotube noticeably contributes to the stability of the outermost tube, and together increase the critical strain amplitude by 155%. However, the three inner layers in the corresponding pristine nanotube, taken together, increase the critical strain of the outermost tube by only 23%. In addition, for both the pristine and functionalized zigzag nanotubes, only the (24, 0) layer, among the three inner layers, contributes to the critical strain of the corresponding outermost tube, by 11% and 29%, respectively. The underlying mechanism of the enhanced stability related to nanotube chirality and functionalization is analyzed in detail.

3.
Eur Rev Med Pharmacol Sci ; 24(6): 2911-2927, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32271409

RESUMEN

We reviewed studies comparing survival outcomes such as overall survival (OS), progression free survival (PFS), and toxicity profile between patients treated with Pegylated Liposomal Doxorubicin (PLD) combination and those treated with paclitaxel combination for ovarian cancer. We conducted systematic searches in various databases including Medline, Cochrane Controlled Register of Trials (CENTRAL), ScienceDirect, and Google Scholar from inception until August 2019. We used the Cochrane risk of bias tool to assess the quality of published trials. We carried out a meta-analysis with random-effects model and reported pooled Hazard ratios (HR) or Risk ratios (RR) with 95% confidence intervals (CIs). In total, we analysed 7 studies including 3,676 participants. All the studies were randomized controlled trials, while majority of studies had low bias risks. We did not find significant evidence for any of these outcomes except progression free survival (favoured PLD combination therapy pooled HR=0.87; 95% CI: 0.77-0.98). Worst grade toxicities like allergy (pooled RR: 1.86; 95% CI: 1.06-3.24) and neurotoxicity (pooled RR: 5.59; 95% CI: 1.43-21.84) were significantly higher among patients receiving paclitaxel combination therapy when compared to patients receiving PLD combination therapy. To summarize, PLD combination therapy is non-inferior to paclitaxel combination therapy in the management of ovarian cancer with respect to survival outcomes and worst grade toxicity profile. However, clinical recommendations cannot be made, as the evidence is not conclusive or significant enough.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carboplatino/uso terapéutico , Doxorrubicina/análogos & derivados , Neoplasias Ováricas/tratamiento farmacológico , Paclitaxel/uso terapéutico , Supervivencia sin Enfermedad , Doxorrubicina/uso terapéutico , Femenino , Humanos , Polietilenglicoles/uso terapéutico , Ensayos Clínicos Controlados Aleatorios como Asunto
4.
Eur Rev Med Pharmacol Sci ; 24(11): 5970-5978, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32572910

RESUMEN

OBJECTIVE: The aim of this study was to investigate the effects of long non-coding ribonucleic acid regulator of reprogramming (lncRNA ROR) on the proliferation and apoptosis of endometrial cancer (EC) cells, and to explore its possible underlying mechanism. PATIENTS AND METHODS: The expression levels of lncRNA ROR and Notch1 in EC tissues were detected via quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The changes in Notch1 protein were detected via Western blotting. Subsequently, the regulatory mechanism of lncRNA ROR on Notch1 was analyzed using Luciferase reporter gene assay. Moreover, the changes in cell proliferation and apoptosis were determined through cell counting kit-8 (CCK-8) assay and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, respectively. RESULTS: Both lncRNA ROR and Notch1 were highly expressed in EC tissues (p<0.05). After overexpression of lncRNA ROR, HEC-1A cells had significantly enhanced proliferation (p<0.05) and weakened apoptosis (p<0.05). Meanwhile, the mRNA and protein levels of Notch1 rose remarkably compared with those in control group (p<0.05). Luciferase reporter gene assay revealed that lncRNA ROR could bind to the Notch1 regulatory factor miR-34a and inhibit its activity. CONCLUSIONS: LncRNA ROR regulates the proliferation and apoptosis of EC cells via promoting the expression of Notch1 protein.


Asunto(s)
Neoplasias Endometriales/metabolismo , ARN Largo no Codificante/metabolismo , Receptor Notch1/metabolismo , Apoptosis , Proliferación Celular , Neoplasias Endometriales/patología , Femenino , Humanos , MicroARNs/genética , MicroARNs/metabolismo , ARN Largo no Codificante/genética , Receptor Notch1/genética , Células Tumorales Cultivadas
5.
J Oral Rehabil ; 36(4): 284-91, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19220714

RESUMEN

The purpose of this study was to investigate influences of buccal bi-cortical anchorages on natural frequency (NF) values of dental implants in different diameters utilizing the three-dimensional finite element method. Three degrees of buccal bi-cortical engagements were generated in D2 and D3 bone quality models, which were 0-mm engagement (i.e. implants just had contact with the buccal cortex), 0.5-mm (i.e. implants were penetrated into the buccal cortex by 0.5 mm) and 1.0-mm engagement, while only 0- and 0.5-mm engagement were simulated in D4 bone models. The uni-cortical engagement was set as the control. By the modal analysis, NF values of bending and axial vibration mode were computed as a function of different bi-cortical engagements. The results showed that buccal bi-cortical anchorages significantly enhanced bending and axial NF values. The increasing rates resulting from 0.5-mm engagement ranged from 10.5 to 42.3%, with a mean of 24.3%. From 0- to 0.5-mm engagement, the NF values maintained an increasing trend, and from 0.5- to 1.0-mm engagement, the values levelled off or even decreased. In 0.5- and 1.0-mm engagement models, increasing implant diameter resulted in small increases of NF values. In conclusion, buccal bi-cortical anchorages could significantly increase both bending and axial NF values of dental implants, but extra-buccal cortical bone engagement could not produce considerable incremental increases of NF values as anticipated. Increasing implant diameter could result in limited increases of NF values in case of implants being bi-cortically anchored.


Asunto(s)
Implantes Dentales/normas , Retención de Prótesis Dentales/métodos , Prótesis Dental de Soporte Implantado/métodos , Análisis del Estrés Dental/métodos , Métodos de Anclaje en Ortodoncia/métodos , Fenómenos Biomecánicos/fisiología , Fuerza de la Mordida , Simulación por Computador , Diseño Asistido por Computadora/instrumentación , Retención de Prótesis Dentales/instrumentación , Prótesis Dental de Soporte Implantado/instrumentación , Análisis del Estrés Dental/instrumentación , Análisis de Elementos Finitos , Humanos , Modelos Biológicos , Métodos de Anclaje en Ortodoncia/instrumentación
6.
Eur J Obstet Gynecol Reprod Biol ; 141(1): 18-22, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18752884

RESUMEN

OBJECTIVE: To study the efficacy of uterine electrical stimulation (ES) with various parameters in delaying delivery in term- and preterm-laboring animals. STUDY DESIGN: Catheters and electrodes, as well as ES electrodes, were sutured onto the uterine horn in day-15 pregnant rats. ES with various durations/frequencies (five sets of parameters) was tested from gestation day 21 to determine its effects on uterine contractility. The best set of ES parameters was applied in term (day 21) and preterm (day 18-labor induced) animals to determine the effects of ES on delivery. RESULTS: (1) Significant reduction in uterine contractions (0.54+/-0.11 vs. 0.86+/-0.08 contractions per minute, P<0.001) was noted with ES of only one of the five sets of parameters (set #5 with pulse train of 10s on and 10s off, 28ms pulse width, frequency of 30Hz and amplitude of 4mA); (2) ES with parameter set 5 delayed delivery by 12.5h (P=0.01) and reduced area under the curve of intrauterine pressure in mmHgs (311+/-147.21 vs. 848.75+/-350.38, P<0.05) and AUC-electromyographic activity is area under rectified (i.e. absolute value) uterine EMG trace in mVs (145.25+/-93.1 vs. 410+/-182.46, P<0.05) in the term rats; and (3) similar effects were noted with ES in preterm rats with a delay in delivery by 28h (P<0.001), and a decrease in IUP-AUC (intrauterine pressure-area under curve) (101.5+/-55.45 vs. 551+/-269.06, P=0.017) and EMG-AUC (64.25+/-43.63 vs. 172.5+/-62.91, P=0.03). CONCLUSION: ES of the uterus with appropriate parameters inhibits uterine contractions and delays delivery in both term and preterm rats.


Asunto(s)
Estimulación Eléctrica , Nacimiento Prematuro/prevención & control , Tocólisis/métodos , Animales , Modelos Animales de Enfermedad , Electromiografía , Femenino , Embarazo , Ratas , Ratas Sprague-Dawley , Nacimiento a Término , Contracción Uterina/fisiología
7.
Nanoscale ; 8(6): 3760-7, 2016 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-26815838

RESUMEN

Based on first principles calculations and self-consistent solution of the linearized Boltzmann-Peierls equation for phonon transport approach within a three-phonon scattering framework, we characterize lattice thermal conductivities k of freestanding silicene, germanene and stanene under different isotropic tensile strains and temperatures. We find a strong size dependence of k for silicene with tensile strain, i.e., divergent k with increasing system size; however, the intrinsic room temperature k for unstrained silicene converges with system size to 19.34 W m(-1) K(-1) at 178 nm. The room temperature k of strained silicene becomes as large as that of bulk silicon at 84 µm, indicating the possibility of using strain in silicene to manipulate k for thermal management. The relative contribution to the intrinsic k from out-of-plane acoustic modes is largest for unstrained silicene, ∼39% at room temperature. The single mode relaxation time approximation, which works reasonably well for bulk silicon, fails to appropriately describe phonon thermal transport in silicene, germanene and stanene within the temperature range considered. For large samples of silicene, k increases with tensile strain, peaks at ∼7% strain and then decreases with further strain. In germanene and stanene, increasing strain hardens and stabilizes long wavelength out-of-plane acoustic phonons, and leads to similar k behaviors to those of silicene. These findings further our understanding of phonon dynamics in group-IV buckled monolayers and may guide transfer and fabrication techniques for these freestanding samples and engineering of k by size and strain for applications of thermal management and thermoelectricity.

8.
Transl Psychiatry ; 6: e748, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26926884

RESUMEN

An extensive literature links circadian irregularities and/or sleep abnormalities to mood disorders. Despite the strong genetic component underlying many mood disorders, however, previous genetic associations between circadian clock gene variants and major depressive disorder (MDD) have been weak. We applied a combined molecular/functional and genetic association approach to circadian gene polymorphisms in sex-stratified populations of control subjects and case subjects suffering from MDD. This approach identified significant sex-dependent associations of common variants of the circadian clock genes hClock, hPer3 and hNpas2 with major depression and demonstrated functional effects of these polymorphisms on the expression or activity of the hCLOCK and hPER3 proteins, respectively. In addition, hCLOCK expression is affected by glucocorticoids, consistent with the sex-dependency of the genetic associations and the modulation of glucocorticoid-mediated stress response, providing a mechanism by which the circadian clock controls outputs that may affect psychiatric disorders. We conclude that genetic polymorphisms in circadian genes (especially hClock and hPer3, where functional assays could be tested) influence risk of developing depression in a sex- and stress-dependent manner. These studies support a genetic connection between circadian disruption and mood disorders, and confirm a key connection between circadian gene variation and major depression.


Asunto(s)
Relojes Circadianos/fisiología , Ritmo Circadiano/fisiología , Trastorno Depresivo Mayor/fisiopatología , Variación Genética/fisiología , Relojes Circadianos/genética , Ritmo Circadiano/genética , Trastorno Depresivo Mayor/genética , Femenino , Variación Genética/genética , Humanos , Masculino , Factores Sexuales
9.
Transplantation ; 52(6): 984-8, 1991 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1721252

RESUMEN

University of Wisconsin solution has been used successfully in clinical kidney and liver preservation. The object of this study was to determine if low-potassium UW (LPUW) solution could be applied to pulmonary preservation. Rabbit lungs were stored after hypothermic pulmonary artery (PA) flush with four different solutions (group 1: low-potassium dextran (LPD) solution, group 2: high-potassium UW (HPUW) solution, group 3: LPUW solution, group 4: modified Euro-Collins (E-C) solution). The lungs were preserved at 10 degrees C for 30 hr and evaluated in an ex vivo ventilation/perfusion apparatus using fresh pooled venous rabbit blood. Mean PA flush pressures (MFP) during harvesting were significantly lower in groups 1 and 3 (8.1 +/- 1.0 mmHg and 7.3 +/- 0.6 mmHg, respectively; mean +/- SEM) than in groups 2 and 4 (15.5 +/- 1.7 mmHg and 12.3 +/- 0.9 mmHg, respectively). Lungs in groups 1 and 3 showed significantly higher PaO2 (103.5 +/- 8.0 mmHg and 89.3 +/- 7.2 mmHg) than groups 2 and 4 (48.3 +/- 7.7 mmHg, 66.7 +/- 4.7 mmHg). Groups 1 and 3 showed significantly lower wet/dry weight (W/D) ratios after reperfusion (6.21 +/- 0.15 and 6.39 +/- 0.23) than groups 2 and 4 (7.70 +/- 0.57 and 7.13 +/- 0.21, respectively). There were no significant differences in MFP, PaO2, PaCO2, mean pulmonary artery pressure, or W/D ratio between groups 1 and 3. These results suggest that LPUW solution may be as beneficial as LPD solution for pulmonary arterial flush and lung preservation.


Asunto(s)
Pulmón , Soluciones Preservantes de Órganos , Preservación de Órganos/métodos , Potasio/análisis , Soluciones/química , Adenosina , Alopurinol , Animales , Análisis de los Gases de la Sangre , Dextranos , Glutatión , Soluciones Hipertónicas , Insulina , Conejos , Rafinosa
10.
Zhonghua Fu Chan Ke Za Zhi ; 29(4): 224-6, 253-4, 1994 Apr.
Artículo en Zh | MEDLINE | ID: mdl-8082446

RESUMEN

Effect of Mylis and Tiluoan on cervical ripening and blood levels of estradiol and progesterone of pregnant rats were studied. Dehydroepiandrosterone (DHA) is the main component in both of the drugs. Pregnant rats groups were given the drugs on the 19th day of gestation at dosage of 10, 20 and 40 mg/kg respectively. The results indicated that both drugs at different dose were able to significantly decrease the cervical extensibility, to dilate the cervical OS, increase the cervical wet weight, and elevate the blood estradiol level, lower the progesterone concentration. It indicated that DHA enhances estradiol synthesis and suppresses progesterone secretion.


Asunto(s)
Cuello del Útero/efectos de los fármacos , Deshidroepiandrosterona/análogos & derivados , Animales , Deshidroepiandrosterona/farmacología , Sulfato de Deshidroepiandrosterona , Estradiol/sangre , Femenino , Inicio del Trabajo de Parto/sangre , Embarazo , Progesterona/sangre , Ratas , Ratas Sprague-Dawley
11.
Zhongguo Zhong Yao Za Zhi ; 14(12): 731-4, 762, 1989 Dec.
Artículo en Zh | MEDLINE | ID: mdl-2699715

RESUMEN

This paper reviews recent developments in the research of solubility rate, bioavailability and pharmacokinetics of Chinese medicinal preparations. The significance of these developments for prescription improvement, dosage form selection, technological formulation and rational drug-taking has also been discussed.


Asunto(s)
Medicamentos Herbarios Chinos/farmacocinética , Animales , Disponibilidad Biológica , Medicamentos Herbarios Chinos/administración & dosificación , Humanos , Solubilidad
12.
Facts Views Vis Obgyn ; 4(4): 237-44, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-24753915

RESUMEN

In this paper we focus on preterm birth as a uterine contractility disorder caused by hypercontractility of the -myometrium. We describe changes in uterine function during term and preterm labor and delivery. We also examine the usefulness of measurement of uterine electromyographic (EMG) activity, noninvasively monitored from the -abdominal surface of pregnant patients. The use of progesterone treatment for preterm birth is discussed and we conclude that present therapies with progesterone could be improved by changing the route of administration. -Finally we show the results of recent studies that show that progesterone injections completely inhibit uterine EMG activity when given several days to hours before normal delivery. These studies illustrate how progesterone suppresses labor at term or preterm, probably through repression of genes which control excitability and conduction of electrical activity. However, direct profusion of soluble progesterone into the uterine cavity has little immediate inhibitory action and this may demonstrate that progesterone has no direct, nongenomic effects, at least in the rat model used. Further studies are required to determine the effects of progesterone on human uterine EMG activity and whether progesterone treatments will prevent preterm birth.

13.
J Burn Care Res ; 31(5): 716-27, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20628306

RESUMEN

Based on the application of Laplace's law to compression garments, an equation for predicting garment pressure, incorporating the body circumference, the cross-sectional area of fabric, applied strain (as a function of reduction factor), and its corresponding Young's modulus, is developed. Design procedures are presented to predict garment pressure using the aforementioned parameters for clinical applications. Compression garments have been widely used in treating burning scars. Fabricating a compression garment with a required pressure is important in the healing process. A systematic and scientific design method can enable the occupational therapist and compression garments' manufacturer to custom-make a compression garment with a specific pressure. The objectives of this study are 1) to develop a pressure prediction model incorporating different design factors to estimate the pressure exerted by the compression garments before fabrication; and 2) to propose more design procedures in clinical applications. Three kinds of fabrics cut at different bias angles were tested under uniaxial tension, as were samples made in a double-layered structure. Sets of nonlinear force-extension data were obtained for calculating the predicted pressure. Using the value at 0° bias angle as reference, the Young's modulus can vary by as much as 29% for fabric type P11117, 43% for fabric type PN2170, and even 360% for fabric type AP85120 at a reduction factor of 20%. When comparing the predicted pressure calculated from the single-layered and double-layered fabrics, the double-layered construction provides a larger range of target pressure at a particular strain. The anisotropic and nonlinear behaviors of the fabrics have thus been determined. Compression garments can be methodically designed by the proposed analytical pressure prediction model.


Asunto(s)
Vendajes , Quemaduras/complicaciones , Cicatriz Hipertrófica/etiología , Cicatriz Hipertrófica/terapia , Vestuario , Textiles , Anisotropía , Diseño de Equipo , Humanos , Ensayo de Materiales , Modelos Biológicos , Presión , Estrés Mecánico
16.
J Chem Phys ; 124(2): 024711, 2006 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-16422630

RESUMEN

A complete surface reconstruction takes place after a local connection between two crossed tubes is established, leading to the creation of an extended X-shaped junction constituted by topological defects with smooth negative curvature. Molecular-dynamics simulations show that the surface reconstructions occur through (1) generalized Stone-Wales transformation and (2) the movement of sp and sp3 atoms and their transformation to sp2 atoms by bond rearrangement. Based on both the principle of energy minimization and a generalized Euler's rule, it is demonstrated that the most stable structure for X junctions contains only 12 heptagons. The annealing temperature influences the topological structure and stability of junctions.

17.
Am J Obstet Gynecol ; 185(4): 959-65, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11641685

RESUMEN

OBJECTIVE: To investigate the effect of cervical application of nonselective and selective inhibitors of nitric oxide synthases--N-nitro-L-arginine methyl ester, L-N-iminoethyl-lysine, and aminoguanidine--as well as inhibitors of cyclooxygenases--indomethacin, and nimesulide--on timing of delivery and fetal death and disease in pregnant rats. STUDY DESIGN: In a series of experimental protocols, timed-pregnant Sprague-Dawley rats (length of pregnancy, 22 days) were randomly allocated to daily cervical applications of (1) 0.04 mg (n = 6), 0.4 mg (n = 6), 4 mg (n = 6), or 40 mg (n = 6) L-N-iminoethyl-lysine or vehicle (n = 12) on days 19 to 22 of pregnancy; (2) 50 mg aminoguanidine (n = 6), 150 mg aminoguanidine (n = 6), or vehicle (n = 10) on days 19 to 22 of pregnancy; (3) 3 mg indomethacin (n = 6) or vehicle (n = 6) on days 19 to 22 of pregnancy; (4) 12.5 mg/kg nimesulide (n = 8), 25 mg/kg nimesulide (n = 8), 50 mg/kg nimesulide (n = 12), or vehicle (n = 12) on days 19 to 22 of pregnancy and 50 mg/kg nimesulide (n = 23) or vehicle (n = 23) on days 14 to 22 of pregnancy; (5) 50 mg/kg nimesulide (n = 10), 50 mg aminoguanidine plus 50 mg/kg nimesulide (n = 10), 50 mg aminoguanidine (n = 10), or vehicle (n = 10) on days 14 to 22 of pregnancy. The following variables were evaluated: proportion of animals that were delivered on day 23, time to delivery of the first pup (midnight on day 22 was considered to be 0 hour), number of stillborn pups, and average pup weight of each litter. RESULTS: Unlike L-N-iminoethyl-lysine, aminoguanidine, and indomethacin, 50 mg/kg nimesulide applied on the cervix daily for 8 days significantly increased the proportion of animals that were delivered on day 23 (18 of 23 versus 7 of 23; P =.003) and the time to delivery of the first pup by a mean of 10.8 hours (P <.001). Shorter treatment with nimesulide for 4 days increased only the time to delivery of the first pup at the 25-mg/kg dosage (P =.008). Simultaneous application of aminoguanidine and nimesulide significantly (P =.008) prolonged pregnancy to a degree similar to nimesulide alone. The experiment with N-nitro-L-arginine methyl ester was aborted because of severe maternal side effects. Unlike pups in the L-N-iminoethyl-lysine, aminoguanidine, and nimesulide groups, significantly more pups in the indomethacin group died in utero compared with the control group (36.1% versus 3.1%; P <.001), and the surviving pups had lower birth weights (P <.001). CONCLUSIONS: In an animal model, nimesulide was effective in delaying the onset of labor, was well tolerated during pregnancy, and affected cervical ripening directly independent of progesterone withdrawal. Conversely, cervical application of nitric oxide synthase and nonselective cyclooxygenase inhibitors do not extend the duration of pregnancy in the dosages studied, and some are associated with significant adverse effects in the mothers and fetuses.


Asunto(s)
Maduración Cervical/efectos de los fármacos , Inhibidores de la Ciclooxigenasa/farmacología , Muerte Fetal , Guanidinas/farmacología , Indometacina/farmacología , NG-Nitroarginina Metil Éster/administración & dosificación , Sulfonamidas/farmacología , Administración Tópica , Animales , Cuello del Útero/efectos de los fármacos , Cuello del Útero/fisiología , Parto Obstétrico/métodos , Femenino , Modelos Animales , Embarazo , Resultado del Embarazo , Preñez , Probabilidad , Ratas , Ratas Sprague-Dawley , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Resultado del Tratamiento
18.
Mol Hum Reprod ; 6(4): 382-9, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10729322

RESUMEN

The exact mechanisms that regulate cervical softening or ripening during pregnancy are not completely understood. The aim of this study was to estimate the effects of various agents on cervical softening during pregnancy in rats. Cervical resistance was examined after treatment with nitric oxide (NO) donors and inhibitors and different hormonal agents. Cervical resistance was significantly reduced (P< 0.05) in rats treated with the NO donors: sodium nitroprusside, molsidomine and prostaglandin E(2). However, treatments with the NO synthase (NOS) inhibitors N(omega)-nitro-L-arginine methyl ester (L-NAME) and L-N(6)-1-iminoethyl-lysine (L-NIL), or the prostaglandin synthesis inhibitor, indomethacin, significantly increased resistance (P<0.05). The antiprogesterone, onapristone, reduced cervical resistance and its effects were only partially blocked by the progesterone agonist, promegestone. Relaxin reduced cervical resistance and NOS inhibitors partially blocked the effect of relaxin. These studies demonstrate that NO regulates cervical ripening. Relaxin also softens the cervix and may act by stimulating NO synthesis. Progesterone seems important in the control of cervical ripening, but its role appears complex. NO and prostaglandin pathways may independently control ripening by acting in parallel or synergistically.


Asunto(s)
Maduración Cervical/efectos de los fármacos , Preñez , Animales , Maduración Cervical/fisiología , Dinoprostona/metabolismo , Femenino , Lisina/análogos & derivados , Lisina/farmacología , Contracción Muscular , Músculo Liso/fisiología , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa de Tipo II , Nitroprusiato/farmacología , Embarazo , Progesterona/farmacología , Ratas , Ratas Sprague-Dawley , Relaxina/farmacología
19.
Am J Obstet Gynecol ; 184(4): 686-93, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11262473

RESUMEN

OBJECTIVE: Some but not all studies have shown that long-term nitric oxide synthase inhibition during pregnancy induces symptoms similar to those of preeclampsia that include hypertension, proteinuria, and intrauterine growth restriction. This study was undertaken to compare the effects of long-term nitric oxide synthase inhibition during pregnancy on blood pressure and fetal weight between Sprague-Dawley rats from outbred colonies of two different suppliers. STUDY DESIGN: Osmotic minipumps were inserted on day 10 or day 17 of pregnancy in Sprague-Dawley rats obtained from Charles River Laboratories, Inc, Wilmington, Mass, or Harlan Sprague Dawley, Inc, Indianapolis, Ind. The pumps were set to deliver vehicle only (control group) or N omega-nitro-L -arginine methyl ester (a nitric oxide synthase inhibitor) at a rate of 50 mg/d until postpartum day 7. Systolic blood pressures were measured daily with the tail-cuff method. Neonatal weights and survival were recorded. RESULTS: N omega-nitro-L -arginine methyl ester infusion initiated on gestational day 10 increased blood pressure relative to control levels in all rats studied. Harlan rats were much more sensitive to the hypertensive effect of N omega-nitro-L -arginine methyl ester. When N omega-nitro-L -arginine methyl ester infusion was initiated on gestational day 17, blood pressure increased only in Harlan rats. Pups born to Harlan rats treated with N omega-nitro-L -arginine methyl ester had lower birth weights and a higher stillbirth rate than did pups of Charles River rats. The degree of hypertension was significantly correlated with the deleterious effects of N omega-nitro-L -arginine methyl ester on the fetuses. CONCLUSION: Within the same strain of rats the effects of long-term nitric oxide synthase inhibition on blood pressure and fetal outcome depended on the original animal colony, with animals from Harlan Sprague Dawley being more sensitive than those from Charles River Laboratories. This difference in response between animals from different suppliers is most likely caused by genetic differences inbred into the strain. In addition to explaining some of the reported inconsistencies between laboratories, these results may also provide insights into the genetic basis of preeclampsia.


Asunto(s)
Óxido Nítrico/antagonistas & inhibidores , Animales , Presión Sanguínea/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Femenino , Muerte Fetal/inducido químicamente , Retardo del Crecimiento Fetal/inducido químicamente , Peso Fetal/efectos de los fármacos , Edad Gestacional , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Nitroarginina/farmacología , Embarazo , Ratas , Ratas Sprague-Dawley , Especificidad de la Especie
20.
J Perinat Med ; 27(3): 188-94, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10503180

RESUMEN

During pregnancy the role of the cervix shifts between two opposing functions. Throughout most of gestation, the cervix is rigid and resists tension in order to maintain the products of conception inside the uterus. At term, however, cervical function changes drastically in order to accommodate stretch and delivery. The events that control cervical function are not known. The aim of this study was to characterize changes in cervical resistance and collagen content during pregnancy in the rat. To determine the change in cervical resistance, non-pregnant and timed pregnant Sprague Dawley rats were sacrificed at various times. Their cervices were isolated and suspended in organ baths connected to a cervimeter for measurement of the stretch-tension relationship. In a different group of animals, cervical collagen content was measured using light-induced fluorescence in non-pregnant and, longitudinally, in pregnant rats. Cervical resistance and collagen content decreased progressively during pregnancy. The changes in cervical resistance mirrored those in cervical collagen content and the nadir in both occurred about two days prior to the onset of labor. Our study suggests that cervical preparation for delivery does not occur acutely at the time of labor and that cervical collagen content determines cervical resistance.


Asunto(s)
Cuello del Útero/fisiología , Colágeno/análisis , Fluorescencia , Preñez/fisiología , Animales , Fenómenos Biomecánicos , Femenino , Luz , Embarazo , Ratas , Ratas Sprague-Dawley
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