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1.
BMC Med ; 16(1): 159, 2018 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-30143037

RESUMEN

The original article [1] contains errors in Table 1 affecting some of the presented oligonucleotide sequences and readthrough values in Table 1.

2.
Gene Ther ; 21(8): 759-66, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24919419

RESUMEN

Site-specific endonucleases can be engineered for custom recognition of any genetic locus and used for gene targeting. Yet, the prolonged expression and accumulation of these nucleases in cells lead to toxic effect. Here we describe an efficient and quantitative method for introducing nucleases into cells as proteins packaged within lentiviral vector particles. I-CreI-derived meganucleases, which can be engineered as single-chain proteins, were incorporated into lentiviral vector particles either without modification or as fusions with cyclophilin A. The small amount of nuclease delivered by the viral particles is sufficient to induce efficient targeted mutagenesis in human HEK293H and primary T cells. When a repair template sequence was packaged in the lentiviral vector, high levels of homologous gene targeting were obtained and toxicity was markedly reduced.


Asunto(s)
Marcación de Gen/métodos , Endonucleasas/química , Endonucleasas/genética , Vectores Genéticos , Células HEK293 , Humanos , Lentivirus/genética , Mutagénesis Sitio-Dirigida/métodos , Linfocitos T/enzimología
3.
Diabetologia ; 56(2): 330-9, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23178930

RESUMEN

AIMS/HYPOTHESIS: The main objective of this work was to discover new drugs that can activate the differentiation of multipotent pancreatic progenitors into endocrine cells. METHODS: In vitro experiments were performed using fetal pancreatic explants from rats and mice. In this assay, we examined the actions on pancreatic cell development of glibenclamide, a sulfonylurea derivative, and glycine hydrazide (GlyH-101), a small-molecule inhibitor of cystic fibrosis transmembrane conductance regulator (CFTR). We next tested the actions of GlyH-101 on in vivo pancreatic cell development. RESULTS: Glibenclamide (10 nmol/l-100 µmol/l) did not alter the morphology or growth of the developing pancreas and exerted no deleterious effects on exocrine cell development in the pancreas. Unexpectedly, glibenclamide at its highest concentration promoted endocrine differentiation. This glibenclamide-induced promotion of the endocrine pathway could not be reproduced when other sulfonylureas were used, suggesting that glibenclamide had an off-target action. This high concentration of glibenclamide had previously been reported to inhibit CFTR. We found that the effects of glibenclamide on the developing pancreas could be mimicked both in vitro and in vivo by GlyH-101. CONCLUSIONS/INTERPRETATION: Collectively, we demonstrate that two small-molecule inhibitors of the CFTR, glibenclamide and GlyH-101, increase the number of pancreatic endocrine cells by increasing the size of the pool of neurogenin 3-positive endocrine progenitors in the developing pancreas.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística/antagonistas & inhibidores , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Gliburida/farmacología , Glicina/análogos & derivados , Hidrazinas/farmacología , Páncreas/citología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Femenino , Glicina/farmacología , Inmunoquímica , Ratones , Proteínas del Tejido Nervioso/metabolismo , Técnicas de Cultivo de Órganos , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Embarazo , Ratas , Ratas Wistar , Reacción en Cadena en Tiempo Real de la Polimerasa
4.
Allergy ; 67(3): 403-12, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22188019

RESUMEN

BACKGROUND: Nasal polyposis, a chronic inflammatory disease affecting the upper airways, is a valuable and accessible model to investigate the mechanisms underlying chronic inflammation. The main objective of this study was to investigate a potential involvement of the unfolded protein response (UPR) in the context of oxidative stress and inflammation in nasal epithelial cells from nasal polyps (NP). METHODS: Epithelial cells from NP (n = 20) and normal mucosa (Controls, n = 15) in primary culture were analyzed by global proteomic approach and cell biology techniques for the glucose-regulated protein 78 (GRP78), the spliced X-box-binding protein 1 (sXBP-1), the glucose-regulated protein 94 (GRP94), and the calreticulin (immunoblot, mass spectrometry, immunocytochemistry). RESULTS: Proteomics analysis of human nasal epithelial cells in culture revealed the activation of the unfolded protein response in NP. Systematic cell biology and biochemical analysis of two markers (GRP78, sXBP-1) in the presence and absence of oxidative stress in NP showed a susceptibility of the unfolded protein response to oxidative stress compared to controls at least partially linked to an abnormal redox state of the protein disulfide-isomerase 4. This unfolded protein response was correlated with mitochondrial depolarization and secretion of interleukin 8 (IL-8) and leukotriene B4 (LTB4) and was prevented by mitochondrial antioxidant. CONCLUSIONS: We show the existence of UPR in nasal epithelial cells that is linked to oxidative stress leading to IL-8 and LTB4 secretions. These mechanisms may participate in chronic inflammation in nasal polyposis.


Asunto(s)
Células Epiteliales/patología , Inflamación/inmunología , Mucosa Nasal/inmunología , Pólipos Nasales/fisiopatología , Estrés Oxidativo , Respuesta de Proteína Desplegada , Antioxidantes/farmacología , Células Cultivadas , Chaperón BiP del Retículo Endoplásmico , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Humanos , Interleucina-8/metabolismo , Leucotrieno B4/metabolismo , Mucosa Nasal/citología , Pólipos Nasales/inmunología , Proteoma , Proteómica
5.
J Racial Ethn Health Disparities ; 9(2): 620-629, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-33721290

RESUMEN

Latinx in the USA experience disparities in morbidity and mortality when compared to their non-Hispanic White counterparts. Patient-centered culturally sensitive health care (PC-CSHC) has been deemed a best practice approach to alleviate and eliminate these disparities. However, literature on how Latinx patients perceive their care and what indicators of PC-CSHC may be most related to treatment outcomes is limited. This study collected data from 81 adult Latinx participants who had been admitted to an inpatient care unit to understand the following: (a) their perception of their providers' PC-CSHC in three different areas: Competence/Confidence, Sensitivity/Interpersonal, and Respect/Communication; (b) whether there are differences between English- and Spanish-speaking Latinx patients in their perception of their providers' PC-CSHC; and (c) whether these PC-CSHC indicators were associated to patient satisfaction, patient-provider communication, and therapeutic alliance. Participants were mostly male, older than 55 years of age, and working or lower class, with English as their primary language. Results showed that patients rated their providers' Competence (M = 3.57, SD = .46) higher than both Sensitivity, t(68) = .04, p = .04, (M = 3.49, SD =.54), and Respect, t(53) = 2.765, p = .008, (M = 3.38, SD = .57). English-speaking Latinx were overall less satisfied with their providers than Spanish-speaking Latinx, in particular in their communication. Finally, higher provider cultural sensitivity appears to be a predictor of patient satisfaction, patient-provider communication, and working alliance. Implications for refining provider trainings to treat this vulnerable and understudied (i.e., Latinx) population are discussed.


Asunto(s)
Asistencia Sanitaria Culturalmente Competente , Hispánicos o Latinos , Satisfacción del Paciente , Alianza Terapéutica , Adulto , Comunicación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Relaciones Médico-Paciente
6.
Hum Reprod ; 26(2): 330-6, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21126966

RESUMEN

BACKGROUND: The aim of this study was to determine if oral contraceptive (OC) use affects body weight, body composition and metabolism in primates. METHODS: Reproductive-age female rhesus monkeys of normal and obese BMI were studied to document baseline weight stability, then treated continuously with an OC (dosed to achieve equivalent human serum levels for a 30 µg ethinyl estradiol/150 µg levonorgestrel preparation) for 237 days. Monkeys were monitored for changes in body weight, levels of physical activity (measured by a triaxial Actical accelerometer), food/caloric intake, percent body fat (dual energy X-ray absorptiometry, DEXA) and metabolism (24 h metabolic rate and serum metabolic substrate and hormone concentrations). RESULTS: All 10 monkeys completed the study protocol with no adverse events. While body weight (-0.73% change) and percent body fat (-1.78% change) of the normal BMI group did not significantly decrease from baseline, obese monkeys showed a significant decrease in body weight (-8.58% change, P < 0.01) and percent body fat (-12.13% change P = 0.02) with OC treatment. In both the obese (P = 0.03) and the normal BMI (P = 0.01) groups, there was a significant increase in basal metabolic rate with OC use. No changes were seen in food intake, activity level or % lean muscle mass with OC use for either BMI-based group. CONCLUSIONS: Overall, OC use appears to cause a slight increase in basal metabolic rate in female monkeys, leading to a decrease in body weight and percent body fat in obese individuals.


Asunto(s)
Composición Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Anticonceptivos Orales Combinados/farmacología , Obesidad/fisiopatología , Animales , Metabolismo Basal/efectos de los fármacos , Ingestión de Energía/efectos de los fármacos , Etinilestradiol/administración & dosificación , Femenino , Levonorgestrel/administración & dosificación , Macaca mulatta
7.
Science ; 244(4911): 1469-72, 1989 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-2472007

RESUMEN

Chloride channels mediate absorption and secretion of fluid in epithelia, and the regulation of these channels is now known to be defective in cystic fibrosis. Indanyl-oxyacetic acid 94 (IAA-94) is a high-affinity ligand for the chloride channel, and an affinity resin based on that structure was developed. Solubilized proteins from kidney and trachea membranes were applied to the affinity matrix, and four proteins with apparent molecular masses of 97, 64, 40, and 27 kilodaltons were eluted from the column by excess IAA-94. A potential-dependent 36Cl- uptake was observed after reconstituting these proteins into liposomes. Three types of chloride channels with single-channel conductances of 26, 100, and 400 picosiemens were observed after fusion of these liposomes with planar lipid bilayers. Similar types of chloride channels have been observed in epithelia.


Asunto(s)
Cloruros/aislamiento & purificación , Canales Iónicos , Corteza Renal/análisis , Proteínas de la Membrana/aislamiento & purificación , Tráquea/análisis , Animales , Bacteriorodopsinas/metabolismo , Bovinos , Canales de Cloruro , Cloruros/fisiología , Cloro/metabolismo , Cromatografía de Afinidad , Conductividad Eléctrica , Electroforesis en Gel de Poliacrilamida , Indanos , Canales Iónicos/fisiología , Luz , Liposomas/metabolismo , Potenciales de la Membrana/efectos de los fármacos , Proteínas de la Membrana/fisiología , Peso Molecular , Radioisótopos , Valinomicina/farmacología
8.
Contraception ; 97(5): 422-427, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29409834

RESUMEN

BACKGROUND: As part of a program to develop a novel estradiol-releasing contraceptive vaginal ring (CVR), we evaluated the pharmacokinetic (PK) profile of CVRs releasing segesterone acetate (Nestorone® (NES)) combined with one of three different estradiol (E2) doses. STUDY DESIGN: A prospective, double-blind, randomized, multi-centered study to evaluate a 90-day CVR releasing NES [200mcg/day] plus E2, either 10mcg/day, 20mcg/day, or 40mcg/day in healthy reproductive-age women with regular cycles. Participants provided blood samples twice weekly for NES and E2 levels during the first 60 days (ring 1) and the last 30 days (ring 2) of use. A subset underwent formal PK assessments at ring initiation, ring exchange (limited PK), and study completion. RESULTS: The main study enrolled 197 women; 22 participated in the PK substudy. Baseline characteristics between the main and PK participants were comparable, with an average BMI of 25.8 kg/m2 (SD 4.3). In the PK substudy, all three rings showed similar NES PK: mean area under the curve (AUC(0-72)) 34,181 pg*day/mL; concentration maximum (Cmax) 918 pg/mL; time to maximum concentration (Tmax) 3.5 h. For E2, the Cmax occurred at 2 h, and was significantly higher with the 20 mcg/day ring (mean 390 pg/mL); 10 mcg/day, 189 pg/mL, p=.003; 40 mcg/day, 189 pg/mL, p<.001), and declined rapidly to≤50 pg/mL for all doses by 24 h. For all subjects, the median E2 levels remained under 35 pg/mL during treatment. CONCLUSION: PK parameters of NES were not affected when paired with different doses of E2, but E2 levels from all three doses were lower than anticipated and no dose response was observed. IMPLICATIONS: While these novel estradiol-releasing combination contraceptive vaginal rings provided sustained release of contraceptive levels of Nestorone over 90 days, the E2 levels achieved were not consistent with bone protection, and a dose-response was not observed.


Asunto(s)
Anticonceptivos Femeninos/farmacocinética , Dispositivos Anticonceptivos Femeninos , Estradiol/farmacocinética , Norprogesteronas/farmacocinética , Adulto , Anticoncepción , Anticonceptivos Femeninos/administración & dosificación , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Estradiol/administración & dosificación , Femenino , Humanos , Norprogesteronas/administración & dosificación , Estudios Prospectivos , Estados Unidos , Adulto Joven
10.
Cancer Res ; 61(4): 1693-8, 2001 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-11245485

RESUMEN

The inhibition of the Na+/K+-ATPase by cardiotonic drugs like ouabain deeply perturbs both the properties of the cell membrane and the ionic composition of the cytoplasm and hence alters fundamental cell reactions. These three types of reactions may be involved in the stimulation of multidrug resistance 1 (MDR-1) gene expression and the synthesis of permeability glycoprotein [P-glycoprotein (P-gp)]. We have determined whether ouabain, which binds to an extracellular motif of the Na+/K+-ATPase, stimulates MDR-1 gene expression by measuring both mRNA and protein and whether the resulting P-gp extrudes hydrophobic compounds and causes resistance to antimitotic agents. The experiments were performed on Calu-3 cells, a human cell line from a pulmonary carcinoma. Northern blotting showed that treating the cells with submicromolar concentrations of ouabain stimulated MDR-1 gene expression within 24 h. The ouabain-induced stimulation of MDR-1 expression was not restricted to Calu-3 cells but also occurred in human carcinomatous colon (T-84 and HT-29) and hepatic (H7V3) cells. However, it is not ubiquitous because it was not found in HeLa cells. The stimulation was reproduced by other Na+/K+-ATPase inhibitors and occurred via enhanced gene transcription, apparently due to the increased cytosolic calcium concentration. Ouabain also increased the membrane content of P-gp, as detected by immunoblotting and immunohistology. We have developed a microvideo assay based on the properties of acetoxymethyl ester calcein and calcein to show that this P-gp extruded the hydrophobic acetoxymethyl ester calcein. Ouabain also caused the Calu-3 cells to become resistant to doxorubicin and vinblastine. Thus, although ouabain acts extracellularly, it may stimulate MDR-1 gene expression and P-gp synthesis and make cells resistant to hydrophobic cytotoxic compounds.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/biosíntesis , Resistencia a Múltiples Medicamentos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genes MDR/efectos de los fármacos , Ouabaína/farmacología , Mucosa Respiratoria/efectos de los fármacos , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Antibióticos Antineoplásicos/farmacocinética , Antibióticos Antineoplásicos/farmacología , Antineoplásicos Fitogénicos/farmacocinética , Antineoplásicos Fitogénicos/farmacología , Transporte Biológico/efectos de los fármacos , Cardiotónicos/farmacología , Línea Celular , Doxorrubicina/farmacocinética , Doxorrubicina/farmacología , Resistencia a Antineoplásicos , Inhibidores Enzimáticos/farmacología , Fluoresceínas/farmacocinética , Colorantes Fluorescentes/farmacocinética , Humanos , ARN Mensajero/genética , Mucosa Respiratoria/metabolismo , Mucosa Respiratoria/fisiología , Estimulación Química , Células Tumorales Cultivadas , Vinblastina/farmacocinética , Vinblastina/farmacología
11.
J Proteomics ; 145: 246-253, 2016 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-27397611

RESUMEN

UNLABELLED: We have previously shown (i) that the cystic fibrosis transmembrane regulator (CFTR) locates to lipid raft-like microdomains of epithelial cells upon TNF-α proinflammatory stimulation; and (ii) that TNF-α increases the membrane localization and the channel function of F508del-mutated CFTR. In the present work, we hypothesized that CFTR mutations modify the proteome of lipid rafts in the same proinflammatory conditions. We prepared lipid rafts from HeLa cells transfected with either wild-type or F508del-CFTR and incubated for 10min with 100U/mL of TNF-α. Proteins were extracted, trypsin digested, and peptides analyzed by high resolution MS. Proteins were quantified by a stable isotope labeling with amino acids in cell culture approach. Out of the 22 proteins differentially recruited in lipid rafts after proinflammatory exposure, 17 were increased in F508del cells with respect to wild-type, including two G-protein coupled receptors, three anion transporters, and one cell surface mucin. In both HeLa and bronchial epithelial cells we confirmed that G-protein coupled receptor 5A relocates to lipid rafts along with F508del-CFTR after TNF-α treatment. These results could enlighten the cross-talk between CFTR and TNF-α and its impact on the cell response to proinflammatory challenge. BIOLOGICAL SIGNIFICANCE: CFTR mutations are at the origin of cystic fibrosis. The latter disease is characterized, among other symptoms, by a defective management of infection and inflammation in the airways. Short exposure to the proinflammatory cytokine TNF-α targets mutated CFTR to the plasma membrane and increases its chloride channel activity. The results hereby presented show a substantial modification of the lipid raft proteome in the same conditions, and may enlighten the effect of this cytokine and the role of CFTR in the cell response to inflammation.


Asunto(s)
Fibrosis Quística/patología , Microdominios de Membrana/química , Proteoma/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Bronquios , Células Cultivadas , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Células Epiteliales , Células HeLa , Humanos , Inflamación , Mutación , Proteoma/análisis , Proteómica/métodos
12.
Data Brief ; 9: 51-6, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27626054

RESUMEN

Cystic fibrosis (CF) is a genetic disease due to mutations in the cystic fibrosis transmembrane regulator (CFTR), F508del-CFTR being the most frequent. Lipid raft-like microdomains (LRM) are regions of the plasma membrane that present a high cholesterol content and are insoluble to non-ionic detergents. LRM are essential functional and structural platforms that play an important role in the inflammatory response. CFTR is a known modulator of inflammation in LRM. Here we provide mass spectrometry data on the global impact of CFTR mutation and TNF-a stimulation on the LRM proteome. We used the Stable Isotope Labeling by Amino Acids in Cell Culture (SILAC) approach to quantify and identify 332 proteins in LRM upon TNF-a stimulation in CF cells and 1381 for the global proteome. We report two detailed tables containing lists of proteins obtained by mass spectrometry and the immunofluorescence validation results for one of these proteins, the G-protein coupled receptor 5A. These results are associated with the article "Changes in lipid raft proteome upon TNF-α stimulation of cystic fibrosis cells" (Chhuon et al., in press [1]).

13.
Biochim Biophys Acta ; 1146(2): 183-90, 1993 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-8452854

RESUMEN

The anion conductive pathways in preparations of endoplasmic reticulum (ER)-enriched microsomes from pig pancreas were investigated. The rate of swelling induced by cation ionophores (nigericin (nig) and/or valinomycin (val)) was measured in iso-osmotic solutions by light scattering, in the presence or absence of an inward Cl- and/or pH gradients. The rate of swelling in the presence of the inward Cl- gradient and ionophores was faster than that of controls. Low pH did not change the swelling rate in the presence of valinomycin, but it increased it in the presence of nigericin. When the Cl- gradient was abolished, valinomycin plus the pH gradient increased the rate of swelling, and this was further enhanced by nigericin. Anion transport inhibitors reduced the swelling rate. The nigericin-induced swelling was stimulated by ATP and GTP. The non-hydrolysable analogues, adenosine 5'-[beta,gamma-methylene]triphosphate, guanosine 5'-[beta-thio]triphosphate and guanosine 5'-[beta-thio]diphosphate, increased the rate of swelling, whereas adenosine 5'-[gamma-thio]triphosphate inhibited it. ADP, CTP and UTP had no effect. These data suggest the presence of a Cl-/OH- exchanger and a Cl- conductance in microsomes. They indicate that nucleotides may regulate the Cl-/OH- exchanger. Nucleotides do not need to be hydrolyzed but phosphorylation may occur to counter-balance the nucleotide-induced stimulation.


Asunto(s)
Cloruros/metabolismo , Retículo Endoplásmico/efectos de los fármacos , Hidróxidos/metabolismo , Nucleótidos/farmacología , Páncreas/efectos de los fármacos , Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-disulfónico/análogos & derivados , Ácido 4-Acetamido-4'-isotiocianatostilbeno-2,2'-disulfónico/farmacología , Adenosina Difosfato/farmacología , Adenosina Trifosfato/farmacología , Animales , Retículo Endoplásmico/metabolismo , Guanosina Trifosfato/farmacología , Concentración de Iones de Hidrógeno , Intercambio Iónico , Microsomas/efectos de los fármacos , Nigericina , Páncreas/metabolismo , Porcinos , Valinomicina
14.
Biochim Biophys Acta ; 1152(2): 319-27, 1993 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-8218333

RESUMEN

The Cl- conductance of endoplasmic reticulum-enriched pancreatic microsomes was identified. Its regulation by nucleotides was investigated by measuring the rate of cation ionophore-induced microsome swelling in the presence of an inward Cl- gradient. The conductance was solubilized and reconstituted into liposomes. The Cl- conductance in intact microsomes was inhibited by stilbene (10(-4) M) and indanyloxyacetic acid (10(-5) M) derivatives. ATP increased Cl- conductance with half-maximal stimulation at 8 x 10(-6) M. Other trinucleotides (GTP, CTP and UTP) were without effect at 10(-4) M. The non-hydrolysable analogue of ATP, adenosine 5'-[beta gamma-methylene]triphosphate (AppCH2p) increased Cl- conductance with a potency similar to that of ATP. The same concentration of adenosine 5'-[gamma-thio]triphosphate (ATP gamma S) which is a substrate for kinases, had no effect. ATP stimulation of Cl- conductance was inhibited by stilbene derivatives. The data suggest the presence of at least one ATP-binding site, and show that the ATP does not need to be hydrolyzed and that its spatial conformation is important for activating the Cl- conductance. Solubilized microsomal proteins reconstituted into liposomes retained their stilbene-inhibited, ATP-stimulated Cl- conductance. A 167 kDa protein was detected by anti-CFTR antibodies in the intact microsomes, but not in the solubilized proteins. The 64 kDa protein (a component of a ubiquitous Cl- channel) was detected in the both intact and solubilized microsomes. These results suggest that this Cl- conductance is not a CFTR protein.


Asunto(s)
Adenosina Trifosfato/análogos & derivados , Cloruros/metabolismo , Retículo Endoplásmico/metabolismo , Páncreas/metabolismo , Animales , Sitios de Unión , Canales de Cloruro/metabolismo , Conductividad Eléctrica/efectos de los fármacos , Glicolatos/farmacología , Liposomas/química , Microsomas/metabolismo , Páncreas/ultraestructura , Estilbenos/farmacología , Porcinos
15.
Biochim Biophys Acta ; 731(2): 211-6, 1983 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-6682679

RESUMEN

The effects of D-glucose addition to a glucose-free luminal perfusate were investigated in the proximal tubule of Necturus kidney, by electrophysiological techniques. The main findings are: (1) In the presence of sodium, D-glucose produces 10.5 mV +/- 1.1 (S.E.) depolarization. (2) Phlorizin reduces the magnitude of this response to 2.1 +/- 0.1 mV. (3) The glucose-evoked depolarization, delta VG, does not alter the intracellular K+ activity nor is it affected by peritubular addition of ouabain. (4) Isosmotic reduction of Na+ concentration in luminal perfusate from 95 to 2 mmol/l (choline or Li+ substituting for Na+) does not change the magnitude of delta VG; complete removal of sodium from the lumen lowers the value of delta VG (3.2 +/- 0.2 mV) but the response is not abolished. This observation suggests that the D-glucose carrier of renal tubules in Necturus is poorly specific with regard to the cotransported cation species.


Asunto(s)
Proteínas Portadoras/metabolismo , Glucosa/metabolismo , Túbulos Renales Proximales/metabolismo , Animales , Membrana Celular/metabolismo , Cinética , Proteínas de Transporte de Monosacáridos , Necturus , Florizina/farmacología
16.
Biochim Biophys Acta ; 514(1): 137-44, 1978 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-718904

RESUMEN

The effects of 0.5 mM 4-acetamido-4'-isothiocyano-stilbene-2,2' disulfonic acid on the electrical properties of the peritubular membrane were studied in the proximal tubule of the perfused Necturus kidney. The addition of stilbene isothiocyanate disulfonic acid in peritubular perfusate resulted in an average 4.5 mV hyperpolarization with no detectable changes of peritubular membrane input conductance. The depolarization elicited by high-K media was enhanced by 18% in the presence of stilbene isothiocyanate disulfonic acid, an observation indicating that the inhibitor increased the contribution of potassium to membrane potential, presumably by decreasing anionic permeabilities. The hyperpolarizing effect of stilbene isothiocyanate disulfonic acid was abolished when peritubular bicarbonate was removed from the medium and isoosmotically replaced by chloride. These data suggest that (a) intracellular bicarbonate activity is higher than that predicted from passive distribution, (b) stilbene isothiocyanate disulfonic acid decreases P HCO3, thus hyperpolarizing the membrane, (c) chloride distribution appears to be passive when bicarbonate is removed from the peritubular perfusate. The state of Cl distribution when extracellular bicarbonate is at physiologic concentration cannot be assessed from the present data.


Asunto(s)
Túbulos Renales Proximales/fisiología , Estilbenos/farmacología , Animales , Bicarbonatos/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/fisiología , Cloruros/farmacología , Potenciales de la Membrana/efectos de los fármacos , Perfusión , Urodelos
17.
Biochim Biophys Acta ; 732(1): 300-3, 1983 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-6688186

RESUMEN

Cell membrane potential, Vm, was monitored in rabbit hypertrophic cartilage metatarsals, amphibian proximal tubule and muscle cells during application of 1,25-dihydroxy vitamin D-3, 25-hydroxy vitamin D-3 or cholesterol (10(-10) M). 1,25-Dihydroxy vitamin D-3 elicited quick variations of Vm (in less than 1 min) in proximal tubular cells (whether injected in the lumen or in peritubular capillaries) and in cartilage. The precursor 25-hydroxy vitamin D-3 and cholesterol produced a small shift of Vm in proximal tubule only when applied from the luminal side, but this change was significantly smaller than that observed with 1,25-dihydroxy vitamin D-3. Muscle cells were unresponsive to both metabolites and cholesterol. It is concluded that rapid effects of 1,25-dihydroxy vitamin D-3 on Vm, in target cells, are specific, most likely due to permeability changes and not related to nuclear protein synthesis; they may contribute to early modulation of cell function.


Asunto(s)
Calcitriol/farmacología , Cartílago/patología , Membrana Celular/fisiología , Animales , Cartílago/fisiología , Hipertrofia , Túbulos Renales/fisiología , Túbulos Renales Proximales/fisiología , Potenciales de la Membrana/efectos de los fármacos , Músculos/fisiología , Especificidad de Órganos , Ouabaína/farmacología , Conejos
18.
J Gen Physiol ; 75(5): 553-87, 1980 May.
Artículo en Inglés | MEDLINE | ID: mdl-7381429

RESUMEN

The electrical properties of the proximal tubule of the in vivo Necturus kidney were investigated by injecting current (as rectangular waves) into the lumen or into the epithelium of single tubules and by studying the resulting changes of transepithelial (VL) and/or cell membrane potential (VC) at various distances from the source. In some experiments paired measurements of VL and VC were performed at two abscissas x and x'. The luminal length constant of about 1,030 micrometer was shown to provide a good estimate of the transepithelial resistance, specific resistance (RTE = 420 omega.cm2) and/or per unit length (rTE = 1.3 x 10(4) omega.cm). The apparent intraepithelial length constant was subject to distortions arising from concomitant current spread in the lumen. The resistances of luminal membrane (rL), basolateral membrane (rB), and shunt pathway (rS) were estimated by two independent methods at 3.5 x 10(4), 1.2 x 10(4), and 1.7 x 10(4) omega.cm, respectively. The corresponding specific resistances were close to 1,200, 600, and 600 omega.cm2. There are two main conclusions of this study. (a) The resistances of cell membranes and shunt pathway are of the same order of magnitude. The figure of the shunt resistance is at variance with the notion that the proximal tubule of Necturus is a leaky epithelium. (b) A rigorous assessment of the conductive properties of concentric cylindrical double cables (such as renal tubules) requires that electrical interactions arising from one cable to another be taken into account. Appropriate equations were developed to deal with this problem.


Asunto(s)
Túbulos Renales Proximales/fisiología , Urodelos/fisiología , Animales , Conductividad Eléctrica , Matemática , Modelos Biológicos
19.
Cochrane Database Syst Rev ; (3): CD004695, 2005 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-16034942

RESUMEN

BACKGROUND: The avoidance of menstruation through extended or continuous administration (greater than 28 days of active pills) of combination oral contraceptives (COCs) has gained legitimacy through its use in treating endometriosis, dysmenorrhea, and menstruation-associated symptoms. Avoidance of menstruation through continuous use of COCs for reasons of personal preference may have additional advantages to women, including improved compliance, greater satisfaction, fewer menstrual symptoms, and less menstruation-related absenteeism from work or school. OBJECTIVES: To determine the differences between COCs dosed continuously (greater than 28 days of active pills) compared with traditional cyclic dosing (21 days of active pills and 7 days of placebo). Our hypothesis was that continuously administered COCs have equivalent efficacy and safety but improved bleeding profiles, amenorrhea rates, adherence, continuation, participant satisfaction, and menstrual symptoms compared with cyclic COCs. SEARCH STRATEGY: We searched computerized databases (Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, POPLINE, LILACS) for trials using continuous or extended COCs during the years 1966 to 2005. We also searched the references in review articles and publications identified for inclusion in the protocol. Investigators were contacted regarding additional references. SELECTION CRITERIA: All randomized controlled trials in any language comparing continuous (greater than 28 days of active pills) versus traditional cyclic administration (21 days of active pills and 7 days of placebo) of COCs for contraception. DATA COLLECTION AND ANALYSIS: Titles and abstracts identified from the literature searches were assessed for potential inclusion. Data were extracted onto data collection forms and then entered into RevMan 4.2. Peto odds ratios with 95% confidence intervals were calculated for all outcomes for dichotomous outcomes. Weighted mean difference was calculated for continuous outcomes. The trials were critically appraised by examining the following factors: study design, blinding, randomization method, group allocation concealment, exclusions after randomization, loss to follow-up, and early discontinuation. Because the included trials did not have a standard treatment (type of pill and time length for continuous dosing), we could not aggregate data into meta-analysis. MAIN RESULTS: Six randomized controlled trials met our inclusion criteria. Study findings were similar between 28-day and extended cycles in regard to contraceptive efficacy (i.e., pregnancy rates) and safety profiles. When compliance was reported, no difference between 28-day and extended cycles was found. Participants reported high satisfaction with both dosing regimens, but this was not an outcome universally studied. Overall discontinuation and discontinuation for bleeding problems were not uniformly higher in either group in most studies. The few studies that reported menstrual symptoms found that the extended cycle group fared better in terms of headaches, genital irritation, tiredness, bloating, and menstrual pain. Five out of the six studies found that bleeding patterns were either equivalent between groups or improved with continuous-dosing regimens. Endometrial lining assessments by ultrasound were done in a small number of participants but all endometrial stripe measurements were less than 5 mm. AUTHORS' CONCLUSIONS: Evidence from existing randomized control trials comparing COCs given continuously (greater than 28 days of active pills) to traditional monthly cyclic dosing (21 days of active pills and 7 days of placebo) is of good quality. However, the variations in type of pill and time length for continuous dosing make direct comparisons between regimens impossible. Future studies should choose a previously described type of pill and dosing regimen. More attention needs to be directed towards participant satisfaction and menstruation-associated symptoms.


Asunto(s)
Anticonceptivos Orales Combinados/administración & dosificación , Ciclo Menstrual/efectos de los fármacos , Esquema de Medicación , Femenino , Humanos , Ciclo Menstrual/fisiología , Menstruación/efectos de los fármacos , Menstruación/fisiología , Ensayos Clínicos Controlados Aleatorios como Asunto
20.
AIDS ; 4(9): 859-64, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2147550

RESUMEN

Proliferation of mononuclear cells from HIV-seropositive patients to B-cell mitogens was studied in the absence and presence of mixed lymphocyte culture supernatants (MLC-sup). The results show: (1) patients' responses to B-cell mitogens overlap with normal responses but are, on average, consistently lower than normal; (2) the addition of MLC-sup increases the proliferative responses to T-cell-independent mitogens, but does not bring patient's responses up to control levels; (3) HIV-positive patients in all clinical categories have decreased responses to B-cell mitogens. Although some patients with AIDS Centers for Disease Control (CDC) group IVC and IVD have the lowest responses, asymptomatic (CDC group II) and AIDS-related complex (ARC; CDC groups III/IVA and IVB) patients also show significant defects. (4) The same patients were recategorized using an immunological staging system. Those patients with more normal immunohematological parameters have significantly greater responses to mitogens compared with patients with more abnormal immunological parameters. The data suggest that immunological staging could provide more information than clinical classification with respect to the underlying immunopathogenic events occurring in HIV infection.


Asunto(s)
Complejo Relacionado con el SIDA/inmunología , Linfocitos B/inmunología , Infecciones por VIH/inmunología , Leucocitos Mononucleares/inmunología , Activación de Linfocitos , Mitógenos/farmacología , Humanos , Prueba de Cultivo Mixto de Linfocitos , Mitógenos de Phytolacca americana/farmacología , Pronóstico
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