Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Public Health Action ; 7(Suppl 1): S94-S99, 2017 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-28744446

RESUMEN

Setting: Recognising the importance of infection prevention and control (IPC), a minimum standards tool (MST) was developed in Liberia to guide the safe (re-) opening and provision of care in health facilities. Objectives: To analyse the implementation of specific IPC measures after the 2014 Ebola virus outbreak between June 2015 and May 2016, and to compare the relative improvements in IPC between the public and private sectors. Design: A retrospective comparative cohort study. Results: We evaluated 723 (94%) of the 769 health facilities in Liberia. Of these, 437 (60%) were public and 286 (40%) were private. There was an overall improvement in the MST scores from a median of 13 to 14 out of a maximum possible score of 16. While improvements were observed in all aspects of IPC in both public and private health facilities, IPC implementation was systematically higher in public facilities. Conclusions: We demonstrate the feasibility of monitoring IPC implementation using the MST checklist in post-Ebola Liberia. Our study shows that improvements were made in key aspects of IPC after 1 year of evaluations and tailored recommendations. We also highlight the need to increase the focus on the private sector to achieve further improvements in IPC.


Contexte : En reconnaissance de l'importance de la prévention et contrôle de l'infection (PCI), le Liberia a élaboré le « minimum standards tool ¼ (MST) afin de guider en toute sécurité l'ouverture/réouverture des structures de santé et la prestation de soins.Objectifs : Analyser la mise en œuvre des mesures spécifiques de PCI après la flambée épidémique d'Ebola en 2014, entre juin 2015 et mai 2016, et comparer les améliorations relatives de la PCI entre le secteur public et privé.Schéma : Une étude rétrospective comparative de cohorte.Résultats : Nous avons évalué 723 (94%) des 769 structures de santé au Liberia. Parmi elles, 437 (60%) étaient publiques et 286 (40%), privées. Il y a eu une amélioration générale des scores MST depuis une médiane de 13 à 14, avec un score maximal de 16. Des améliorations ont été observées dans tous les aspects de la PCI à la fois dans les structures de santé publiques et privées, mais la mise en œuvre de la PCI a été systematiquement plus élevée dans les structures publiques.Conclusions: Nous avons démontré la faisabilité du suivi de la mise en œuvre de la PCI grâce à la check-list de la MST dans le Liberia d'après Ebola. Nous avons montré des améliorations dans des aspects clés de la PCI après une année d'évaluation et adapté les recommandations de la PCI. Nous mettons également en lumière le besoin d'accorder davantage d'attention au secteur privé, de manière à faire davantage de progrès dans la PCI.


Marco de referencia: Al reconocer la importancia de las medidas de prevención y control de las infecciones (PCI), se elaboró en Liberia un instrumento de normas mínimas encaminado a orientar la apertura o reapertura y la prestación de servicios en los establecimientos de atención de salud de manera segura.Objetivos: Analizar la ejecución de medidas específicas de PCI después de la epidemia del Ébola del 2014, entre junio del 2015 y mayo del 2016, y comparar los progresos relativos en la materia entre el sector público y el sector privado.Método: Un estudio retrospectivo de cohortes comparativo.Resultados: Se evaluaron 723 de los 769 establecimientos de salud de Liberia (94%). De estos, 437 pertenecían al sector público (60%) y 286 (40%) al sector privado. Se observó una mejoría global en las puntuaciones del instrumento de normas mínimas de una mediana de 13 a 14, sobre una puntuación máxima de 16. Hubo progresos en todos los aspectos de PCI en los establecimientos del sector público y privado, pero su aplicación fue sistemáticamente más alta en los centros del sector público.Conclusiones: El presente estudio puso en evidencia la factibilidad de vigilar la ejecución de las medidas de PCI utilizando la lista de verificación del instrumento de normas mínimas, después de la epidemia del Ébola en Liberia. Los resultados revelaron progresos en aspectos primordiales, después de un año de evaluaciones y recomendaciones adaptadas en materia de PCI. Se destacó además la necesidad de aumentar la atención prestada al sector privado, con el fin de promover mayores progresos en este campo.

2.
Curr Oncol ; 18(6): 285-94, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22184490

RESUMEN

BACKGROUND: Although arthralgia is a known adverse effect of aromatase inhibitor (ai) treatment in postmenopausal breast cancer patients, few studies have carried out a comprehensive evaluation of the nature, onset, and incidence of musculoskeletal (msk) pain in these patients. We therefore used a pilot study to identify conditions or markers predictive of pain. METHODS: For 24 weeks, we monitored 30 eligible postmenopausal women starting ai therapy. Pre-existing and incident msk conditions and pain were assessed clinically and with ultrasonography of the hands and wrists. In addition, patient questionnaires were used to assess pain before and during ai therapy. Biochemical markers were measured at baseline and at regular intervals after anastrozole therapy began. Gene profiling studies were carried out before and 48 hours after the initial ai administration. RESULTS: Over the 24-week study period, 20 participants (67%) showed no pain symptoms; 5 (17%) experienced low or moderate pain at baseline, which did not increase with ai treatment; and during therapy, 5 (17%) showed exacerbation of pain attributable to osteoarthritis of the hand and to finger flexor tenosynovitis. Although all 30 participants had some degree of msk conditions before anastrozole therapy started, the pre-existing conditions did not necessarily predispose the women to increased pain during anastrozole treatment. Higher levels of urinary N-telopeptides of type i collagen were associated with the groups presenting pain, suggesting a higher extent of pre-existing bone resorption, without significant evolution over the 24-week treatment period. Slightly higher levels of 1,25(OH)(2) vitamin D(3) were observed at baseline in patients with pain increase, but did not significantly change during treatment; however, average levels of 25(OH) vitamin D(3) increased, likely because of supplementation. Although biochemical markers did not discriminate efficiently between pain groups, a signature of 166 genes in peripheral blood mononuclear cells was identified that could stratify patients into the various groups observed in this pilot study. The gene signature was enriched in components of inflammatory signalling and chemokine expression, of antitumoural immunity pathways, and of metabolic response to hormones and xenobiotics, although no clinically significant association could be made in the present study, considering the small number of patients. Nevertheless, the observed trend suggests the feasibility of developing surrogate predictive markers of msk pain. Patient compliance was high in this study and was not affected by pain exacerbation. CONCLUSIONS: Baseline msk assessment showed pre-existing causes for pain in most of the study patients before initiation of the ai. Exacerbation of existing osteoarthritis pain and tenosynovial symptoms was the primary cause of pain increase. Musculoskeletal pain assessment at baseline and prompt treatment of pain symptoms may help to optimize adherence to ai therapy. The value of routinely assessing inflammatory markers such as C-reactive protein and erythrocyte sedimentation rate was not supported by our pilot study. Gene expression profiles in peripheral blood mononuclear cells may be further explored in larger-scale studies as stratification markers to identify patients at risk of developing arthralgia.

3.
Bioorg Med Chem Lett ; 12(18): 2583-6, 2002 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-12182865

RESUMEN

Potent and selective ligands for the human EP3 prostanoid receptor are described. Biaryl compounds bearing a tethered ortho substituted acidic moiety were identified as potent EP3 antagonists based on the SAR described herein. The binding affinity of key compounds on all eight human prostanoid receptors is reported.


Asunto(s)
Receptores de Prostaglandina E/efectos de los fármacos , Sulfonamidas/química , Sulfonamidas/farmacología , Humanos , Subtipo EP3 de Receptores de Prostaglandina E , Relación Estructura-Actividad
4.
In Vitro Cell Dev Biol Anim ; 37(7): 434-9, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11573818

RESUMEN

A few models have been established to study cancer cells in vitro. However, the cellular interactions have rarely been studied specifically using bioengineered cancer constructs combining human carcinoma cells and tumor-associated fibroblasts. We developed an in vitro model of tridimensional bioengineered cancer tissue constructs (bCTC) by seeding mammary epithelial cancer cells or normal keratinocytes over a mesenchymal layer containing tumor-derived fibroblastic cells or normal skin fibroblasts. After the introduction of epithelial cells, each construct was cultured for another 10 d. Histologic analyses showed that carcinoma cell lines could invade the subjacent mesenchymal layer and that the capacity to migrate was related to the invasive potential of cancer cells and the type of fibroblasts used, while noninvasive populations did not. Of the tested epithelial cells, MDA-MB-231 and, to a lesser degree, HDQ-P1 cell lines were invasive, and the invasion was deeper into the mesenchymal component containing tumor-derived fibroblasts. However, with normal skin fibroblasts, the mesenchymal layer was degraded twice faster than with tumor-derived fibroblastic cells. MDA-MB-231 cells and normal keratinocytes induced the highest level of gelatinase B, and the level was lowest with the MCF-7 cell line. The activated form of gelatinase B was, however, induced to the highest levels in the keratinocyte-seeded bCTC containing tumor-derived but not normal fibroblasts. MDA-MB-231 was the only epithelial cancer cell line whose activity of gelatinase A was reduced when cocultured with tumor-derived fibroblasts but not under normal fibroblast stimulation. Finally, a 50/48-kDa gelatinase band has been observed in bCTCs with noninvasive epithelial cells only. Our study demonstrates the selective secretion of gelatinases according to the phenotype of the cells seeded in the various bCTCs.


Asunto(s)
Comunicación Celular , Células Epiteliales/patología , Mesodermo/patología , Neoplasias/patología , Mama , Neoplasias de la Mama/patología , Técnicas de Cocultivo , Medios de Cultivo , Humanos , Inmunohistoquímica , Queratinocitos , Queratinas/análisis , Metaloproteinasa 2 de la Matriz/análisis , Metaloproteinasa 9 de la Matriz/análisis , Metaloproteinasas de la Matriz/metabolismo , Invasividad Neoplásica , Células Tumorales Cultivadas , Vimentina/análisis
5.
Bioorg Med Chem ; 9(8): 1977-84, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11504634

RESUMEN

Potent and selective antagonists of the human EP3 receptor have been identified. The structure-activity relationship of the chemical series was conducted and we found several analogues displaying sub-nanomolar K(i) values at the EP3 receptor and micromolar activities at the EP1, EP2 and EP4 receptors. The effect of added human serum albumin (HSA) on the binding affinity at the EP3 receptor was also investigated.


Asunto(s)
Cinamatos/farmacología , Antagonistas de Prostaglandina/farmacología , Receptores de Prostaglandina E/metabolismo , Sulfonamidas/farmacología , Cinamatos/química , Humanos , Antagonistas de Prostaglandina/química , Receptores de Prostaglandina E/efectos de los fármacos , Subtipo EP3 de Receptores de Prostaglandina E , Relación Estructura-Actividad , Sulfonamidas/química
6.
J Exp Bot ; 52(357): 821-7, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11413218

RESUMEN

A greenhouse experiment on broccoli (Brassica oleracea var. italica, cvs Windsor and Arcadia) was carried out in order to demonstrate that supplying nitrogen (N) to meet the nitrogen demands of plant growth stages, through N phasing, improves plant growth and yield, as compared to fertilizing at the conventional, optimal, constant N rate. Two broccoli cultivars and two rates of starter nitrogen fertilizer (optimum, 250 mg l(-1) and sub-optimum, 150 mg l(-1)), were combined with three timings of fertigation change. Shifting N rate, at 60% and 75% of the market plant growth cycle significantly increased shoot dry weight and head fresh weight, compared to the constant-N rates treatments (controls). The highest yield and shoot dry weight were obtained when the N-rate was switched from the optimum level (250 mg l(-1)) to the sub-optimum level (150 mg l(-1)) at inflorescence initiation. The nitrogen-to-growth-stage-fitness effect was determined and partitioned into rate effect and phasing effect. The phasing effect was greatest, on both shoot dry weight and head fresh weight, at inflorescence initiation, and subsequently decreased until harvest time. None of the interactions was significant. The results demonstrated the superiority of nitrogen supply phasing over the conventional fixed-rate-supply method.


Asunto(s)
Brassica/crecimiento & desarrollo , Nitrógeno/metabolismo , Brassica/metabolismo , Hojas de la Planta/metabolismo
7.
Mol Pharmacol ; 59(6): 1446-56, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11353805

RESUMEN

The structure-activity relationship (SAR) of prostaglandin (PG) E(2) at the human EP(1) prostanoid receptor (designated hEP(1)) was examined via the binding and activation of this receptor by a series of 55 prostanoids and analogs. Using clonal human embryonic kidney 293 cell lines expressing recombinant hEP(1), affinity (K(i)), potency (EC(50)), and efficacy data were obtained using a radioligand competitive binding assay and an aequorin-based calcium functional assay. All compounds behaved as full agonists (90-100% of the response elicited by PGE(2)) in this assay, and the correlation between the K(i) and EC(50) values was highly significant (R(2) = 0.86). The results from the SAR analysis can be summarized as follows: 1) the existence and configuration of hydroxyl groups at the 11 and 15 positions of PGE(2) and prostanoid analog structures play a critical role in agonist activity; 2) the carboxyl group is also important for activity and modification of the carboxylic acid to various esters results in greatly reduced affinity and potency; 3) the activity of structures with moderate or weak potency can be enhanced by modification of the omega-tail; and 4) modifications to the ketone at the 9-position are better tolerated, with 9-deoxy-9-methylene-PGE(2) being the most potent agonist tested in the functional assay. The impact of other modifications on agonist potency is also discussed. The results from this study have identified, for the first time, the key structural features of PGE(2) and related prostanoids and prostanoid analogs necessary for activation of hEP(1).


Asunto(s)
Dinoprostona/metabolismo , Prostaglandinas/metabolismo , Receptores de Prostaglandina E/metabolismo , Sitios de Unión , Células Cultivadas , Dinoprostona/química , Humanos , Conformación Molecular , Prostaglandinas/química , Ensayo de Unión Radioligante , Subtipo EP1 de Receptores de Prostaglandina E , Relación Estructura-Actividad
8.
Pathol Res Pract ; 197(3): 175-81, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11314781

RESUMEN

The main drawback of the selective culture of human mammary epithelial cells from primary breast cancer is the overgrowth of tumor-associated stromal fibroblasts. This drawback may be overcome by using, in primary culture, lethally irradiated 3T3 cells which act as a feeder layer to maintain tumor-derived epithelial cell proliferation. These 3T3 cells, exposed to 60 Gy at confluence, form a specific cellular substrate which constitutes an obstacle to fibroblast attachment. Enzyme-disaggregated breast cells from six primary breast carcinomas were cocultured over lethally irradiated but living 3T3 cells. The method led to the purification of tumor-derived epithelial cells from all six cancer samples, and long-term culture was obtained in one. The epithelial nature of these purified tumor-derived epithelial cells was demonstrated by their general morphology and by the expression of cytokeratins and Epithelial Membrane Antigen. These results confirm the stimulatory effect of a this stromal feeder layer on breast epithelial cell growth and show that this stromal feeder layer can also control the fibroblast overgrowth. Our results provide an alternative approach in the selective culture of epithelial cells from primary breast carcinoma.


Asunto(s)
Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Técnicas de Cultivo/métodos , Células Epiteliales/patología , Células Tumorales Cultivadas/fisiología , Células 3T3/citología , Células 3T3/efectos de la radiación , Animales , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/química , Carcinoma Ductal de Mama/química , Técnicas de Cocultivo/métodos , Células Epiteliales/química , Células Epiteliales/fisiología , Femenino , Citometría de Flujo , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Ratones
9.
Bioorg Med Chem Lett ; 11(5): 747-9, 2001 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-11266183

RESUMEN

Potent and selective EP3 receptor ligands were found by making a library using solid-support chemistry. These compounds can be obtained by a Suzuki coupling reaction of a solid-supported benzyl bromide using various boronic acids. The yields obtained for this reaction were in the range of 24-95% of arylmethyl cinnamic acid 1 after cleavage from the Wang resin.


Asunto(s)
Cinamatos/síntesis química , Cinamatos/metabolismo , Técnicas Químicas Combinatorias , Receptores de Prostaglandina E/antagonistas & inhibidores , Receptores de Prostaglandina E/metabolismo , Cinamatos/química , Cinamatos/farmacología , Humanos , Ligandos , Estructura Molecular , Receptores de Prostaglandina E/química , Subtipo EP3 de Receptores de Prostaglandina E , Relación Estructura-Actividad
10.
J Fam Psychol ; 14(2): 286-303, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10870295

RESUMEN

Husbands' and wives' conversations with their respective best friend (N = 88) were coded to assess spouses' and friends' mutual influence in regulating support and interference with regard to spouses' marriage and to assess the impact of spouses' sex and marital satisfaction on the conversation processes. Dissatisfied husbands and wives expressed fewer positive and more negative views of marriage than satisfied husbands and wives and the friends in the 2 groups. There were no group and no sex differences in interference sequences. There were group and sex differences in support sequences. Friends of satisfied wives and those of dissatisfied husbands were more likely than satisfied wives and dissatisfied husbands to get support for their positive views of marriage. The findings are discussed with reference to the specific effects of outsiders' support and interference on satisfied and dissatisfied spouses.


Asunto(s)
Conflicto Psicológico , Identidad de Género , Relaciones Interpersonales , Matrimonio/psicología , Autorrevelación , Adulto , Femenino , Humanos , Control Interno-Externo , Masculino , Satisfacción Personal , Determinación de la Personalidad , Apoyo Social
11.
In Vitro Cell Dev Biol Anim ; 36(2): 96-103, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10718365

RESUMEN

Many studies are being conducted to define the role of growth factors in cutaneous physiology in order to add cytokines in a timely fashion for optimal tissue engineering of skin. This study is aimed at developing a multistep approach for the production of bioengineered skin substitutes, taking into account the effects of various growth factors according to the culture time. The use of a serum-supplemented medium throughout the whole culture period of skin substitutes was compared to the sequential use of specific additives at defined culture steps. Histological analysis revealed that serum was necessary for keratinocyte proliferation and migration on dermal substitutes during the first 2 d after their seeding. However, the serum-free medium presented some advantages when supplemented with different additives at specific culture steps. Interestingly, ascorbic acid added to the dermal substitutes before and after keratinocyte seeding maintained their cuboidal morphology in the basal epidermal layer. In the absence of serum, collagen matrix degradation slowed down, and a better multilayered epidermal organization was obtained, notably with retinoic acid. Stratum corneum formation was also enhanced by fatty acids. Thus, sequential addition of exogenous factors to the medium used to produce skin substitutes can improve their structural features and functional properties in vitro.


Asunto(s)
Queratinocitos/citología , Piel Artificial , Animales , Antioxidantes/farmacología , Ácido Ascórbico/farmacología , Cromatografía Líquida de Alta Presión , Colorantes , Medio de Cultivo Libre de Suero , Técnicas de Cultivo/métodos , Humanos , Queratinocitos/ultraestructura , Queratolíticos/farmacología , Ratones , Microscopía Electrónica , Tretinoina/farmacología
12.
Biochim Biophys Acta ; 1483(2): 285-93, 2000 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-10634944

RESUMEN

Stable cell lines that individually express the eight known human prostanoid receptors (EP(1), EP(2), EP(3), EP(4), DP, FP, IP and TP) have been established using human embryonic kidney (HEK) 293(EBNA) cells. These recombinant cell lines have been employed in radioligand binding assays to determine the equilibrium inhibitor constants of known prostanoid receptor ligands at these eight receptors. This has allowed, for the first time, an assessment of the affinity and selectivity of several novel compounds at the individual human prostanoid receptors. This information should facilitate interpretation of pharmacological studies that employ these ligands as tools to study human tissues and cell lines and should, therefore, result in a greater understanding of prostanoid receptor biology.


Asunto(s)
Membrana Celular/metabolismo , Prostaglandinas/metabolismo , Receptores de Prostaglandina/metabolismo , Unión Competitiva , Línea Celular , Humanos , Ligandos , Ensayo de Unión Radioligante , Receptores de Prostaglandina/agonistas , Receptores de Prostaglandina/antagonistas & inhibidores , Proteínas Recombinantes/metabolismo
13.
Anal Biochem ; 276(2): 215-26, 1999 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-10603245

RESUMEN

The standard method to evaluate CYP3A inhibition is to study the conversion of the specific CYP3A probe testosterone to its 6 beta-hydroxy metabolite in human liver microsomes, in the absence and presence of potential inhibitors. Quantification of the 6 beta-hydroxy metabolite is achieved by HPLC resulting in a tedious and time-consuming assay. In order to increase the P450 inhibition throughput, efforts were made to find a CYP3A probe that would produce a fluorescent metabolite. This paper reports the discovery of DFB as a potential CYP3A fluorescent probe. DFB was significantly metabolized in human microsomes (approximately 1-2 nmol/(min. mg protein)) to give the fluorescent compound DFH. The involvement of CYP3A in the metabolism of DFB was determined using multiple approaches. First, incubations conducted with microsomes made from cell lines expressing single CYPs (Gentest Supersomes) indicated that CYP3A played a major role in the metabolism of DFB. Secondly, immunoinhibition studies conducted with CYP3A antibody resulted in >95% inhibition of DFB metabolism in HLM. Thirdly, inhibition studies with specific CYP1A1, 1A2, 2C8/9, 2C19, 2D6, and 2E1 chemical inhibitors did not suppress DFB activity in HLM. However, ketoconazole, miconazole, nicardipine, and nifedipine, all known CYP3A inhibitors, completely abolished the formation of DFH in HLM. The potency of several inhibitors determined using DFB and testosterone as CYP3A probes was consistent (R = 0.98). Finally, a good agreement was obtained for the formation of DFH and production of 6 beta-hydroxytestosterone when DFB and testosterone were incubated separately with various human liver microsome preparations (R = 0.94, N = 11). In order to use DFH as a fluorescent CYP3A marker in a 96-well plate format, it was important to remove the excess of NADPH at the end of the incubation because the fluorescence of NADPH interferes with DFH detection. This was achieved by adding oxidized glutathione and glutathione reductase to convert NADPH to NADP(+) which is not fluorescent. The liquid-handling steps were fully automated in a 96-well plate format and a template was designed to generate IC(50) curves and to address potential fluorescent interferences from the test compounds. The assay was found to be reproducible (intraday variability <10% and interday variability indicated less than a 2-fold variation in the IC(50) values) and is now routinely used in our laboratory to evaluate CYP3A inhibition of NCEs.


Asunto(s)
Hidrocarburo de Aril Hidroxilasas , Técnicas de Química Analítica/métodos , Inhibidores Enzimáticos del Citocromo P-450 , Colorantes Fluorescentes , Fluorobencenos , Furanos , Microsomas Hepáticos/enzimología , Oxidorreductasas N-Desmetilantes/antagonistas & inhibidores , Línea Celular , Técnicas de Química Analítica/instrumentación , Cromatografía Líquida de Alta Presión , Citocromo P-450 CYP3A , Sistema Enzimático del Citocromo P-450/metabolismo , Colorantes Fluorescentes/metabolismo , Fluorobencenos/metabolismo , Fluorometría , Furanos/metabolismo , Humanos , Técnicas In Vitro , Oxidorreductasas N-Desmetilantes/metabolismo
14.
Bioorg Med Chem Lett ; 9(18): 2699-704, 1999 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-10509919

RESUMEN

A new class of potent and selective ligands for the human EP1 prostanoid receptor is described. SAR studies reported herein allowed the identification of several potent dibenzazocinones bearing an acylsulfonamide side chain. The binding affinity of these compounds on all eight human prostanoid receptors is reported.


Asunto(s)
Azocinas/farmacología , Compuestos de Bifenilo/farmacología , Receptores de Prostaglandina E/efectos de los fármacos , Azocinas/química , Azocinas/metabolismo , Compuestos de Bifenilo/química , Compuestos de Bifenilo/metabolismo , Humanos , Ligandos , Unión Proteica , Receptores de Prostaglandina E/metabolismo , Subtipo EP1 de Receptores de Prostaglandina E , Relación Estructura-Actividad
15.
Biochim Biophys Acta ; 1439(3): 341-52, 1999 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-10446422

RESUMEN

An in vitro human skin equivalent may be obtained by culturing human keratinocytes on a collagen gel containing fibroblasts. The anchored skin equivalent cultured at the air-liquid interface closely resembles human skin and is acceptable for in vitro percutaneous absorption. However, it is still more permeable than human skin. Since intercellular lipids have been recognized to play an important role in skin permeability, infrared spectroscopy and differential scanning calorimetry were performed on the stratum corneum of bovine or human skin equivalents grown at different days of air-liquid culture. The symmetric and asymmetric CH(2) stretching vibrations suggested that for all days observed, the intercellular lipids were less organized than those in human skin, irrespective of whether bovine or human collagen was used. Different culture conditions were also tested and the medium without serum and no epidermal growth factor at the air-liquid culture showed results significantly more comparable to human skin. Actually, the thermal behavior of in vitro stratum corneum showed transitions at lower temperatures than human skin. The transition around 80 degrees C, in the form of a lipid-protein complex, was absent. These results showed that the structural arrangement of intercellular lipids and their thermodynamic properties hold a crucial role in the barrier function of the stratum corneum.


Asunto(s)
Técnicas de Cultivo/métodos , Piel/química , Animales , Rastreo Diferencial de Calorimetría , Bovinos , Colágeno/química , Sistemas de Liberación de Medicamentos , Epidermis/química , Humanos , Lípidos/química , Permeabilidad , Espectroscopía Infrarroja por Transformada de Fourier/métodos
17.
J Reprod Fertil ; 117(2): 229-39, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10690190

RESUMEN

During the oestrous cycle and early pregnancy, the uterus undergoes a variety of morphological and physiological modifications involving uterine cell proliferation and differentiation as well as extensive tissue remodelling. Transforming growth factor beta (TGF-beta) has powerful effects on these events and thus is thought to have a critical role in uterine physiology. Endoglin is a transmembrane glycoprotein that binds TGF-beta 1 and -beta 3 and interacts with TGF-beta signalling receptors to modulate many effects of this growth factor in different types of cell. Studies in mice revealed the highest concentrations of endoglin in the reproductive tract, notably on stromal cells of cyclic and pregnant uteri. The objective of the present study was to investigate the role of endoglin expressed on uterine stromal cells in binding TGF-beta and in the cellular responses induced by this growth factor. Highly purified populations of uterine stromal cells were isolated by cell affinity to the monoclonal antibody MJ7/18, which is specific to mouse endoglin. Affinity labelling of these cells with 125I-labelled TGF-beta followed by immunoprecipitation with endoglin-specific polyclonal 1256:4b antiserum indicated that endoglin expressed at the surface of uterine stromal cells binds TGF-beta 1 and interacts with TGF-beta signalling receptors. Treatment of uterine stromal cells with different concentrations of TGF-beta 1 induced a biphasic proliferative response and addition of MJ7/18 as well as neutralizing TGF-beta antibodies showed endoglin to be a modulator of TGF-beta-induced stromal cell proliferation. Given the importance of TGF-beta in the regulation of uterine physiology, these results indicate a role for endoglin during uterine tissue remodelling and decidualization.


Asunto(s)
Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo , Útero/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo , Animales , Anticuerpos Monoclonales/farmacología , Antígenos CD , División Celular/efectos de los fármacos , Células Cultivadas , Cromatografía de Afinidad , Electroforesis en Gel de Poliacrilamida , Endoglina , Femenino , Citometría de Flujo , Ratones , Ratones Endogámicos , Pruebas de Precipitina , Unión Proteica , Receptores de Superficie Celular , Estimulación Química , Factor de Crecimiento Transformador beta/farmacología , Útero/efectos de los fármacos , Molécula 1 de Adhesión Celular Vascular/inmunología
18.
Somatosens Mot Res ; 16(4): 391-401, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10632035

RESUMEN

Using the method of limits and a magnitude estimation procedure, the sense of touch was examined at multiple sites on the anterior torso of normal subjects. Their performance was compared with the performance of individuals having experienced a functionally complete spinal cord transection more than 6 months prior to the tests. Near the insentient regions of the spinal cord-injured patients there was a zone wherein the threshold for light touch was elevated and variable. Within this same transition zone, estimates of the magnitude of a brushing stimulus increased as a linear function of distance from the border for approximately 12 cm away from insentient skin. Throughout the rest of the thorax, spinal cord-injured patients displayed touch thresholds 67% higher than normals and, at the same test sites, spinal cord-injured patients offered estimates of the intensity of the brushing stimulus that averaged 62% higher than normal subjects. The greater intensity of the sensations experienced by spinal cord-injured patients with even very weak stimuli and the smaller range within which they were able to scale stimulus intensity, produced a situation wherein the patients made frequent errors of judgement even on skin regions far from the body parts affected by the lesion. These observations support the hypothesis that spinal cord lesions interrupt tonic modulatory mechanisms having global influences on the sense of touch. This loss produces an elevation of the touch threshold and a reduction of the normal dynamic range of tactile sensory perception for all skin surfaces on the anterior torso.


Asunto(s)
Abdomen/inervación , Traumatismos de la Médula Espinal/fisiopatología , Tórax/inervación , Tacto/fisiología , Abdomen/fisiología , Adulto , Análisis de Varianza , Femenino , Humanos , Hipoestesia/diagnóstico , Hipoestesia/fisiopatología , Modelos Lineales , Masculino , Persona de Mediana Edad , Estimulación Física , Valores de Referencia , Umbral Sensorial/fisiología , Piel/inervación , Fenómenos Fisiológicos de la Piel , Traumatismos de la Médula Espinal/diagnóstico , Tórax/fisiología
19.
Can J Surg ; 41(4): 283-8, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9711161

RESUMEN

OBJECTIVE: To decrease health costs and morbidity related to extracorporeal circulation, surgeons have modified the coronary artery bypass (CAB) technique so that it can be completed without the use of extracorporeal circulation. This study summarizes initial experience with direct coronary artery revascularization on the beating heart using a coronary stabilizer. DESIGN: A case series. SETTING: The Montreal Heart Institute, a university-affiliated centre, specializing in the treatment of cardiac illnesses. PATIENTS: Ten patients underwent CAB by this technique. They presented with double or triple coronary artery disease with no intramyocardial, heavily calcified, diffused atheromatous coronary vessels, or left main coronary disease. INTERVENTION: CAB grafting in the beating heart. The anterior wall was grafted in all patients, the inferior wall in 7 and the posterior wall in 7. MAIN OUTCOME MEASURES: Patient survival and graft patency. RESULTS: One patient died of multiple organ failure not related to the grafting technique itself, and 1 patient suffered a non-Q myocardial infarction. Early coronary angiography performed on 8 patients showed 100% graft patency, most with excellent distal runoff (21/22 grafts). CONCLUSION: In patients with adequate anatomy, performance of CAB without extracorporeal circulation can achieve excellent early results provided there is appropriate mechanical stabilization of the beating heart.


Asunto(s)
Angina Inestable/cirugía , Puente de Arteria Coronaria/métodos , Enfermedad Coronaria/cirugía , Anciano , Angina Inestable/fisiopatología , Puente de Arteria Coronaria/instrumentación , Enfermedad Coronaria/fisiopatología , Diseño de Equipo , Femenino , Supervivencia de Injerto , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...