RESUMEN

The aims of the study were to determine (1) whether the presence of High blood pressure (HBP) states in the youth associate a steeper rate of age-related change in arterial geometrical and wall properties with respect to subjects with no previous cardiovascular risk factor (CRF) exposure, (2) in which parameters and in what magnitude, and (3) the existence of a gender-related difference in the impact of this condition on arterial properties. 300 individuals (mean/range: 15/4-29 years; 133 females) were included. Two groups were assembled: (1) Reference: nonprevious exposure to traditional CRF and (2) HBP: subjects with arterial hypertension and/or elevated blood pressure (BP) levels during the study. Additionally, HBP subjects were separated in BP-related subgroups. Measured parameters were (1) central (aortic) arterial BP and aortic pulse wave analysis parameters, (2) carotid and femoral artery local (pressure-strain elastic modulus) and regional (pulse wave velocity; PWV) stiffness, and (3) arterial diameters and carotid intima-media thickness (CIMT). Age-related changes in these parameters (absolute values and z-scores) were explored by obtaining simple linear regression models for each group. HBP presented a steeper rate of change (accelerated vascular aging; VA) for most of the parameters assessed, mainly in central (aortic) hemodynamics. VA increased as the HBP level got higher. Both males' and females' aging rates were affected by this condition, but females presented a more marked relative age-related increase with HBP exposure. HBP states in the youth gradually associate accelerated VA, with a progressive hemodynamic-structural-functional onset of damage, with females presenting a more marked relative HBP-associated arterial repercussion.

Asunto(s)

Envejecimiento , Arterias/fisiopatología , Hipertensión/fisiopatología , Enfermedades Vasculares/fisiopatología , Adolescente , Adulto , Aorta/fisiopatología , Presión Arterial , Arterias Carótidas/fisiopatología , Grosor Intima-Media Carotídeo , Niño , Preescolar , Femenino , Arteria Femoral/fisiopatología , Hemodinámica , Humanos , Masculino , Análisis de la Onda del Pulso , Flujo Sanguíneo Regional , Factores de Riesgo , Factores Sexuales , Rigidez Vascular , Adulto Joven

RESUMEN

The aims of our work were to determine normal aging rates for structural and functional arterial parameters in healthy children, adolescents, and young adults and to identify gender-related differences in these aging rates. Methods. 161 subjects (mean: 15 years (range: 4-28 years), 69 females) were studied. Subjects included had no congenital or chronic diseases, nor had they been previously exposed to traditional cardiovascular risk factors. Arterial parameters assessed were (1) central blood pressure (BP) and aortic pulse wave analysis, (2) arterial local (pressure-strain elastic modulus) and regional (pulse wave velocity, PWV) stiffness, and (3) arterial diameters and carotid intima-media thickness (CIMT). Simple linear regression models (age as the independent variable) were obtained for all the parameters and the resulting rates of change were compared between genders. Results. No gender-related differences were found in mean values of arterial structural and functional parameters in prepubertal ages (4-8 years), but they started to appear at ~15 years. Boys showed a greater rate of change for central systolic BP, central pulse pressure, CIMT, and carotid-femoral PWV. Conclusion. Gender-related differences in arterial characteristics of adults can be explained on the basis of different growing-related patterns between boys and girls, with no existing differences in prepubertal ages.

RESUMEN

OBJECTIVES: To evaluate the resources available for early diagnosis and treatment of paediatric sepsis at hospitals in developing and developed countries. METHODS: This was a voluntary online survey involving 101 hospitals from 41 countries solicited through the World Federation of Pediatric Intensive and Critical Care Societies contact list and website. The survey was designed to assess the spectrum of sepsis epidemiology, patterns of applied therapies, availability of resources and barriers to optimal sepsis treatment. RESULTS: Ninety per cent of respondents represented a tertiary or general hospital with paediatric intensive care facilities, including 63% from developed countries. Adequate triage services were absent in more than 20% of centres. Insufficiently trained personnel and lack of a sepsis protocol was reported in 40% of all sites. While there were specific guidelines for sepsis management in 78% of centres (n = 100), protocols for assessing sepsis patients were not applied in nearly 70% of centres. Lack of parental recognition of sepsis and failure of referring centres to diagnose sepsis were identified as major barriers by more than 50% of respondents. CONCLUSIONS: Even among centres with no significant resource constraints and advanced medical systems, significant deficits in sepsis care exist. Early recognition and management remain a key issue and may be addressed through improved triage, augmented support for referring centres and public awareness. Focussed research is necessary at the institutional level to identify and address specific barriers.

RESUMEN

Our current in Mexico is that it represents a serious health problem not yet recognized as low-energy fractures in older adults account for approximately 10% of subjects over 65 years (compared with 29% in Japan) about 4.4 million fractures in patients over 70 years, taking into account that we are a nation of 112 million, the problem is minor compared with other diseases in this and other population groups. In the Mexican health system, orthopedic services instead share with other health priorities, so that the authorities do not understand osteoporosis as a health problem, not observe increased morbidity and mortality that implicitly leads, there are few centers to support the diagnosis of osteoporosis (densitometers do not have), and recruitment, diagnosis and management of patients who have suffered a broken ground mechanically compromised. Have increased the frequency of fractures in osteoporotic ground, and institutional level has only treatments based on calcitriol and calcium to maintain bone mineral density. In the Mexican health system, orthopedic services instead share with other health priorities, so that the authorities do not understand osteoporosis as a health problem, not observe increased morbidity and mortality that implicitly leads, there are few centers to support the diagnosis of osteoporosis (we don't count with densitometers), and recruitment, diagnosis and management of patients who have suffered a broken ground mechanically compromised. Have increased the frequency of fractures in osteoporotic ground, and institutional level has only treatments based on calcitriol and calcium to maintain bone mineral density.

Asunto(s)

Osteoporosis/diagnóstico , Osteoporosis/terapia , Anciano , Calcio/uso terapéutico , Humanos , Guías de Práctica Clínica como Asunto , Vitamina D/uso terapéutico

RESUMEN

El presente estudio se realizó con el objetivo de describir, mediante un enfoque cualitativo, los roles que desempeñan profesionales de enfermería en instituciones geriátricas de Bogotá, los que fueron expresados por ellas mismas, de acuerdo con sus experiencias en el área. El estudio se realizó con el propósito de aportar nuevos conocimientos que puedan servir como base para mejorar la calidad del cuidado de enfermería al adulto mayor que recibe servicios de instituciones geriátricas. La investigación se llevó a cabo con un abordaje cualitativo utilizando la técnica de entrevistas semiestructuradas profundas y permitió concluir que casi en su totalidad, las instituciones geriátricas carecen de profesionales de enfermería, a pesar de la reglamentación de la Secretaría Distrital de Salud – Resolución 110 de 1995, en la que se establece que “la Profesión de Enfermería debe hacer presencia las 24 horas del día en aquellas instituciones en las cuales es atendido el adulto mayor con limitaciones físicas o psíquicas, con requerimiento de cuidado, con enfermedades crónicas o de alto riesgo y en instituciones de atención a pacientes terminarles, así como en hogares día” (1), puesto que las acciones de promoción y prevención y las actividades de incorporación social, son las de mayor importancia y donde la enfermería tiene un amplio campo de acción. Ante las limitaciones presentadas para el contacto con enfermeras en dichas instituciones, debido a la ausencia de este cargo, fue necesario buscar la participación de dos docentes universitarias expertas en el área, quienes reconocieron que los roles que desempeña el Profesional de Enfermería corresponden a: rol asistencial, administrativo, gerencial y educativo, y dentro de éste, el de proyección social; rol investigativo y finalmente, una de ellas relató sus experiencias en el ejercicio independiente de la profesión, con adultos mayores. Se concluyó que las enfermeras participantes tienen claridad acerca de los roles propios de enfermería en el cuidado al adulto mayor y sus relatos coincidieron con la teoría existente al respecto; pero se requiere abrir espacios para que se desarrollen tales roles en las instituciones geriátricas de Bogotá, ya que se cuenta con profesionales capacitados, puesto que el área del adulto mayor forma parte de las competencias de formación profesional específica, establecidas para los programas de Enfermería en Colombia.

Asunto(s)

Anciano , Enfermería Geriátrica , Hospitales Geriátricos , Rol de la Enfermera , Servicios de Salud para Ancianos , Colombia

RESUMEN

OBJECTIVE: To determine the efficacy, tolerance and safety of intramuscular injections of porcine type I collagen-PVP in patients with RA in a long term-therapy. METHODS: The study was a double blind placebo-controlled and included 30 patients with active RA (ACR). Patients were treated with intramuscular injections of 2 ml of collagen-PVP (3.4 mg of collagen) or 2 ml of placebo during 6 months. The follow up was done during the next 6 months. The primary endpoints included the Ritchie index (RI), swollen joint count, disease activity score (DAS), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The secondary endpoints included morning stiffness, pain intensity on a visual analogue scale (VAS), and Spanish-health assessment questionnaire (HAQ-DI). Improvement was determined using American College of Rheumatology response criteria (ACR20, 50 and 70). RESULTS: Collagen-PVP was safe and well tolerated. There were no adverse events. Patients had a statistically significant improvement (p < 0.05) in collagen-PVP-treated vs. placebo at 6 months of treatment in: swollen joint count (7.1 +/- 0.8 vs. 16.0 +/- 1.6), RI (8.1 +/- 0.8 vs. 15.2 +/- 1.5), morning stiffness (9.2 +/- 3.1 vs. 29.1 +/- 5.9 min), HAQ-DI (50.0 +/- 10.8 vs. 22.9 +/- 10.3), DAS (3.0 +/- 0.2 vs. 4.9 +/- 0.3), ACR20 (78.6 vs. 71.4%), ACR50 (57.1 vs. 0%) and ACR70 (7.1 vs. 0%) and CRP (1.1 +/- 0.4 vs. 2.5 +/- 0.7). Patients treated with collagen-PVP required lower doses of methotrexate vs. placebo (12.6 +/- 0.6 vs. 14.2 +/- 0.7 at 6 months and 12.3 +/- 0.8 vs. 15.4 +/- 0.6 at 12 months; p < 0.05). Serological or haematological parameters remained unchanged. CONCLUSION: Collagen-PVP has been shown to be a safe and well-tolerated drug for the long-term treatment of RA. Combination of collagen-PVP plus methotrexate was more efficacious than methotrexate alone. This biodrug can be useful in the treatment of RA.

Asunto(s)

Antirreumáticos/uso terapéutico , Artritis Reumatoide/tratamiento farmacológico , Colágeno Tipo I/uso terapéutico , Povidona/uso terapéutico , Adulto , Animales , Antirreumáticos/administración & dosificación , Artritis Reumatoide/fisiopatología , Colágeno Tipo I/administración & dosificación , Método Doble Ciego , Quimioterapia Combinada , Femenino , Estado de Salud , Humanos , Inyecciones Intramusculares , Masculino , Persona de Mediana Edad , Povidona/administración & dosificación , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Porcinos

RESUMEN

Apyrase/ATP-diphosphohydrolase hydrolyzes di- and triphosphorylated nucleosides in the presence of a bivalent ion with sequential release of orthophosphate. We performed studies of substrate specificity on homogeneous isoapyrases from two potato tuber clonal varieties: Desiree (low ATPase/ADPase ratio) and Pimpernel (high ATPase/ADPase ratio) by measuring the kinetic parameters K(m) and k(cat) on deoxyribonucleotides and fluorescent analogues of ATP and ADP. Both isoapyrases showed a broad specificity towards dATP, dGTP, dTTP, dCTP, thio-dATP, fluorescent nucleotides (MANT-; TNP-; ethene-derivatives of ATP and ADP). The hydrolytic activity on the triphosphorylated compounds was always higher for the Pimpernel apyrase. Modifications either on the base or the ribose moieties did not increase K(m) values, suggesting that the introduction of large groups (MANT- and TNP-) in the ribose does not produce steric hindrance on substrate binding. However, the presence of these bulky groups caused, in general, a reduction in k(cat), indicating an important effect on the catalytic step. Substantial differences were observed between potato apyrases and enzymes from various animal tissues, concerning affinity labeling with azido-nucleotides and FSBA (5'-p-fluorosulfonylbenzoyl adenosine). PLP-nucleotide derivatives were unable to produce inactivation of potato apyrase. The lack of sensitivity of both potato enzymes towards these nucleotide analogues rules out the proximity or adequate orientation of sulfhydryl, hydroxyl or amino-groups to the modifying groups. Both apyrases were different in the proteolytic susceptibility towards trypsin, chymotrypsin and Glu-C.

Asunto(s)

Apirasa/química , Apirasa/metabolismo , Tubérculos de la Planta/enzimología , Solanum tuberosum/enzimología , Marcadores de Afinidad , Sitios de Unión , Isoenzimas , Cinética , Proteínas de Plantas , Desnaturalización Proteica , Especificidad por Sustrato

RESUMEN

Experimental data on the Escherichia coli transcriptional regulatory system has been used in the past years to predict new regulatory elements (promoters, transcription factors (TFs), TFs' binding sites and operons) within its genome. As more genomes of gamma-proteobacteria are being sequenced, the prediction of these elements in a growing number of organisms has become more feasible, as a step towards the study of how different bacteria respond to environmental changes at the level of transcriptional regulation. In this work, we present TRACTOR_DB (TRAnscription FaCTORs' predicted binding sites in prokaryotic genomes), a relational database that contains computational predictions of new members of 74 regulons in 17 gamma-proteobacterial genomes. For these predictions we used a comparative genomics approach regarding which several proof-of-principle articles for large regulons have been published. TRACTOR_DB may be currently accessed at http://www.bioinfo.cu/Tractor_DB, http://www.tractor.lncc.br/ or at http://www.cifn.unam.mx/Computational_Genomics/tractorDB. Contact Email id is tractor@cifn.unam.mx(AU)

Asunto(s)

Humanos , Genoma Bacteriano/genética , Bases de Datos de Ácidos Nucleicos , Gammaproteobacteria/genética , Secuencias Reguladoras de Ácidos Nucleicos , Regulón , Factores de Transcripción/metabolismo

RESUMEN

Comparative studies of intrinsic and extrinsic fluorescence of apyrases purified from two potato tuber varieties (Pimpernel and Desirée) were performed to determine differences in the microenvironment of the nucleotide binding site. The dissociation constants (K(d)) of Pimpernel apyrase for the binding of different fluorescent substrate analogs: methylanthranoyl (MANT-), trinitrophenyl (TNP-), and epsilon -derivatives of ATP and ADP were determined from the quenching of Trp fluorescence, and compared with K(d) values previously reported for Desirée enzyme. Binding of non-fluorescent substrate analogues decreased the Trp emission of both isoapyrases, indicating conformational changes in the vicinity of these residues. Similar effect was observed with fluorescent derivatives where, in the quenching effect, the transfer of energy from tryptophan residues to the fluorophore moiety could be additionally involved. The existence of energy transfer between Trp residues in the Pimpernel enzyme was demonstrated with epsilon -analogues, similar to our previous observations with the Desirée. From these results we deduced that tryptophan residues are close to or in the nucleotide binding site in both enzymes. Experiments with quenchers like acrylamide, Cs(+) and I(-), both in the presence and absence of nucleotide analogues, suggest the existence of differences in the nucleotide binding site of the two enzymes. From the results obtained in this work, we can conclude that the differences found in the microenvironment of the nucleotide binding site can explain, at least in part, the kinetic behaviour of both isoenzymes.

Asunto(s)

Apirasa/metabolismo , Nucleótidos/metabolismo , Solanum tuberosum/enzimología , Triptófano/química , Acrilamida/química , Adenosina Difosfato/análogos & derivados , Adenosina Difosfato/metabolismo , Adenosina Trifosfato/análogos & derivados , Adenosina Trifosfato/metabolismo , Apirasa/química , Sitios de Unión , Cesio/química , Yoduros/química , Isoenzimas/química , Isoenzimas/metabolismo , Cinética , Nucleótidos/química , Fotoblanqueo , Solanum tuberosum/química , Espectrometría de Fluorescencia , Especificidad por Sustrato

RESUMEN

Shc protein phosphorylation has been extensively characterized as the initial step that activates a complex mitogenic pathway through its association with Grb2. In the present study, we investigated the adrenergic control of insulin-induced Shc phosphorylation and Shc-Grb2 association, and the modulating effect of streptozotocin-induced diabetes mellitus on Shc phosphorylation and Shc/Grb2 association. Acute treatment with epinephrine, which leads to a normoglycemic insulin-resistant state, does not affect insulin-induced Shc tyrosine phosphorylation or Shc-Grb2 association in liver, muscle, or fat. By contrast, a significant increase in insulin-induced Shc phosphorylation is observed in liver and muscle of rats treated with streptozotocin. The association of Shc/Grb2 is also increased in both tissues following insulin treatment. These data suggest that while epinephrine preserves the insulin-induced phosphorylation of Shc and the mitogenic pathway stimulated by Shc-Grb2 association, treatment with streptozotocin leads to a tissue-specific increase in the activity of the initial step that ultimately results in the activation of the Shc/Grb2 mitogenic pathway.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular , Tejido Adiposo/metabolismo , Agonistas Adrenérgicos/farmacología , Diabetes Mellitus Experimental/metabolismo , Epinefrina/farmacología , Insulina/fisiología , Hígado/metabolismo , Músculo Esquelético/metabolismo , Proteínas/metabolismo , Tirosina/metabolismo , Dominios Homologos src/genética , Animales , Proteína Adaptadora GRB2 , Fosforilación , Ratas , Receptor de Insulina/metabolismo , Proteínas Adaptadoras de la Señalización Shc , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src

RESUMEN

Insulin induces phosphorylation and activation of JAK2 tyrosine, as well as its association with STAT1 and SHP2 in insulin-sensitive tissues of intact rats, thus demonstrating a new pathway in transduction of insulin signals. We investigated this pathway in hearts of rats in three situations of insulin resistance: 72 h of fasting, chronic treatment with dexamethasone, and acute treatment with epinephrine. The acute treatment with epinephrine showed no difference in insulin-induced JAK2 tyrosine phosphorylation or JAK2/STAT1 and JAK2/SHP2 association in comparison with the control. In fasted rats the JAK2 protein concentration decreased, accompanied by a decrease in the stoichiometry of the phosphorylation to 70%, an increase in association of JAK2/STAT1 to 160%, and a decrease in JAK2/SHP2 association to 85%. In the dexamethasone-treated group, the JAK2 protein concentrations increased but the stoichiometry of its phosphorylation decreased to 20%, whereas the JAK2/STAT1 and JAK2/SHP2 associations changed by 70% and 170%, respectively. In fasting and dexamethasone-treated rats, therefore, insulin-induced JAK2 tyrosine phosphorylation decreases, and the JAK2 protein expression is differentially regulated such that the insulin-induced JAK2 association with SHP2 and STAT1 shows opposite interactions with the kinase.

Asunto(s)

Resistencia a la Insulina/fisiología , Miocardio/enzimología , Proteínas Tirosina Quinasas/metabolismo , Proteínas Proto-Oncogénicas , Animales , Proteínas de Unión al ADN/metabolismo , Dexametasona/farmacología , Activación Enzimática/efectos de los fármacos , Epinefrina/farmacología , Ayuno , Péptidos y Proteínas de Señalización Intracelular , Janus Quinasa 2 , Masculino , Miocardio/metabolismo , Fosforilación , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Proteína Tirosina Fosfatasa no Receptora Tipo 6 , Proteínas Tirosina Fosfatasas/metabolismo , Proteínas Tirosina Quinasas/química , Ratas , Ratas Wistar , Factor de Transcripción STAT1 , Transducción de Señal , Transactivadores/metabolismo , Tirosina/metabolismo

RESUMEN

Potato apyrase, a soluble ATP-diphosphohydrolase, was purified to homogeneity from several clonal varieties of Solanum tuberosum. Depending on the source of the enzyme, differences in kinetic and physicochemical properties have been described, which cannot be explained by the amino acid residues present in the active site. In order to understand the different kinetic behavior of the Pimpernel (ATPase/ADPase = 10) and Desirée (ATPase/ADPase = 1) isoenzymes, the nucleotide-binding site of these apyrases was explored using the intrinsic fluorescence of tryptophan. The intrinsic fluorescence of the two apyrases was slightly different. The maximum emission wavelengths of the Desirée and Pimpernel enzymes were 336 and 340 nm, respectively, suggesting small differences in the microenvironment of Trp residues. The Pimpernel enzyme emitted more fluorescence than the Desirée apyrase at the same concentration although both enzymes have the same number of Trp residues. The binding of the nonhydrolyzable substrate analogs decreased the fluorescence emission of both apyrases, indicating the presence of conformational changes in the neighborhood of Trp residues. Experiments with quenchers of different polarities, such as acrylamide, Cs+ and I- indicated the existence of differences in the nucleotide-binding site, as further shown by quenching experiments in the presence of nonhydrolyzable substrate analogs. Differences in the nucleotide-binding site may explain, at least in part, the kinetic differences of the Pimpernel and Desirée isoapyrases.

Asunto(s)

Adenosina Difosfato/metabolismo , Apirasa/metabolismo , Nucleótidos/metabolismo , Proteínas de Plantas/metabolismo , Solanum tuberosum/enzimología , Apirasa/química , Apirasa/aislamiento & purificación , Isoenzimas/química , Isoenzimas/aislamiento & purificación , Proteínas de Plantas/química , Proteínas de Plantas/aislamiento & purificación , Solanum tuberosum/química , Espectrometría de Fluorescencia

RESUMEN

Potato apyrase, a soluble ATP-diphosphohydrolase, was purified to homogeneity from several clonal varieties of Solanum tuberosum. Depending on the source of the enzyme, differences in kinetic and physicochemical properties have been described, which cannot be explained by the amino acid residues present in the active site. In order to understand the different kinetic behavior of the Pimpernel (ATPase/ADPase = 10) and Desirée (ATPase/ADPase = 1) isoenzymes, the nucleotide-binding site of these apyrases was explored using the intrinsic fluorescence of tryptophan. The intrinsic fluorescence of the two apyrases was slightly different. The maximum emission wavelengths of the Desirée and Pimpernel enzymes were 336 and 340 nm, respectively, suggesting small differences in the microenvironment of Trp residues. The Pimpernel enzyme emitted more fluorescence than the Desirée apyrase at the same concentration although both enzymes have the same number of Trp residues. The binding of the nonhydrolyzable substrate analogs decreased the fluorescence emission of both apyrases, indicating the presence of conformational changes in the neighborhood of Trp residues. Experiments with quenchers of different polarities, such as acrylamide, Cs+ and I- indicated the existence of differences in the nucleotide-binding site, as further shown by quenching experiments in the presence of nonhydrolyzable substrate analogs. Differences in the nucleotide-binding site may explain, at least in part, the kinetic differences of the Pimpernel and Desirée isoapyrases.

Asunto(s)

Adenosina Difosfato/metabolismo , Apirasa/metabolismo , Nucleótidos/metabolismo , Solanum tuberosum/enzimología , Apirasa/química , Apirasa/aislamiento & purificación , Cesio/química , Cesio/metabolismo , Yodo/química , Yodo/metabolismo , Isoenzimas/química , Solanum tuberosum/química , Espectrometría de Fluorescencia

RESUMEN

Objetivo: Nuestro objetivo fue el de evaluar la eficacia de la ecografía transvaginal para predecir las patologías endometriales halladas por biopsia en mujeres en edad climatérica con hemorragia uterina anormal. Diseño del Estudio: En un estudio prospectivo, longitudinal, observacional, 29 pacientes climatéricas con hemorragia uterina anormal, cuyas edades fluctuaban entre 35 y 55 años, fueron sometidas a ecografía transvaginal y posterior toma de biopsia endometrial. Se comparó el grosor endometrial y el resultado de histopatología, este último considerado como el diagnóstico definitivo. Resultados: Utilizando un valor referencial de 5mm, la Ecosonografía Transvaginal, en la predicción de las patologías endometriales...

Asunto(s)

Climaterio , Endometrio , Ultrasonografía , Hemorragia Uterina , Ecuador , Maternidades

RESUMEN

Shc is a novel type of tyrosine-phosphorylated protein activated in response to a wide variety of polypeptide ligands. In this study, we used immunoprecipitation and immunoblotting to examine the effect of insulin on Shc tyrosine phosphorylation and Shc/GRB2 association in insulin-sensitive tissues of the intact rat. Following an infusion of insulin, Shc was tyrosine-phosphorylated in the liver, skeletal muscle, and adipose tissue in a time- and dose-dependent fashion, which peaked 5 min after exposure to the hormone and, except in the case of adipose tissue, returned to basal values after 15 min. There was coimmunoprecipitation of Shc and the insulin receptor after stimulation with insulin. Receptor tyrosine kinase activity toward Shc was also observed. Following an infusion of insulin, Shc was found to associate with GRB2. These results demonstrate that after stimulation of rat tissues with insulin, Shc binds to the insulin receptor, is tyrosine-phosphorylated, and subsequently associated with GRB2.

Asunto(s)

Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular , Insulina/farmacología , Fosfotirosina/metabolismo , Proteínas/metabolismo , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Animales , Proteína Adaptadora GRB2 , Immunoblotting , Técnicas de Inmunoadsorción , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Fosforilación , Ratas , Ratas Wistar , Proteínas Tirosina Quinasas Receptoras/metabolismo , Receptor de Insulina/metabolismo , Proteínas Adaptadoras de la Señalización Shc , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src

RESUMEN

Extracellular nucleotides interact with specific receptors on the cell surface and are locally metabolized by ecto-nucleotidases. Biochemical characterization of the ATPase and ADPase activities detected in rat heart sarcolemma, under conditions where mitochondrial ATPase and adenylate kinase were blocked, supports our proposal that both activities correspond to a single enzyme, known as ATP-diphosphohydrolase or apyrase. The physiological function of this enzyme could be dephosphorylation of the nucleotides present in the interstitial heart compartment acting together with 5'-nucleotidase. Both hydrolytic activities have similarities in: sarcolemma localization, bivalent metal ion dependence, optimum pH, effect of several amino acid residue modifiers, competitive inhibition of nucleotide analogs, and broad nucleoside di-and triphosphate specificity. The ATPase activity could not be separated from the ADPase either through isoelectrofocusing or electrophoresis under acid conditions.

Asunto(s)

Apirasa/química , Apirasa/metabolismo , Miocardio/enzimología , Aminoácidos/química , Animales , Apirasa/antagonistas & inhibidores , Cationes/metabolismo , Cationes/farmacología , Membrana Celular/efectos de los fármacos , Membrana Celular/enzimología , Inhibidores Enzimáticos/farmacología , Femenino , Corazón/efectos de los fármacos , Concentración de Iones de Hidrógeno , Focalización Isoeléctrica , Metales/metabolismo , Metales/farmacología , Músculo Esquelético/enzimología , Miocardio/ultraestructura , Oligomicinas/farmacología , Ratas , Ratas Sprague-Dawley , Sarcolema/efectos de los fármacos , Sarcolema/enzimología , Especificidad por Sustrato

RESUMEN

ATP-diphosphohydrolase (apyrase. EC 3.6.1.5) has both ATPase and ADPase activity that are stimulated by bivalent metals, with Ca2+ being the most effective. The possible physiological function of this enzyme, associated with placental and renal microvilli, is related to the extracellular metabolism of nucleotides. A comparison of the biochemical properties of human placenta and rat kidney apyrase is presented, showing similarities in Mr. bivalent metal stimulation, nucleotide nonspecificity, insensitivity towards specific ATPase inhibitors, and lack of essential sulfhydryl and aliphatic hydroxyl groups. We describe the treatment of membrane preparations from both tissues with different detergents and the isoelectric focusing of the solubilized proteins to partially purify apyrase. An ectoenzyme localization is assigned both in microvillus membranes and in the vasculature on the basis of organ perfusion experiments with nucleotides in the presence of antibodies. Placental and kidney microvillus membranes inhibited ADP-induced platelet aggregation, in agreement with an extracellular role. Initial studies on enzyme regulation suggested the existence of at least two types of modulatory proteins: an activating protein in the cytosol of both tissues, and an inhibitory protein associated with placental microsomes. Possible hormonal regulation was investigated in kidneys using in vivo estradiol treatment, but only slight changes in total apyrase activity were observed.

Asunto(s)

Apirasa/metabolismo , Riñón/enzimología , Placenta/enzimología , Animales , Apirasa/química , Estradiol/farmacología , Humanos , Agregación Plaquetaria/efectos de los fármacos , Ratas

RESUMEN

ATP-diphosphohydrolase (apyrase, EC 3.6.1.5) has both ATPase and ADPase activity that are stimulated by bivalent metais, with Ca2+ being the most effective. The possible physiological function of this enzyme, associated with placental and renal microvilli, is related to the extracellular metabolism of nucleotides. A comparison of the biochemical properties of human placenta and rat kidney apyrase is presented, showing similaiities in Mr, bivalent metal stimulation, nucleotide nonspecificity, insensitivity towards specifjc ATPase inhibitors, and lack of essential sulfhydryl and aliphatic hydroxyl groups. We describe the treatment of membrane preparations from both tissues with different detergents and the isoelectric focusing of the solubilized proteins to partially purify apyrase. An ectoenzyme localization is assigned both in microvillus membranes and in the vasculature on the basis of organ perfusion experiments with nucleotides in the presence of antibodies. Placental and kidney microvillus membranes inhibited ADP-induced platelet aggregation, in agreement with an extracellular role. Initial studies on enzyme regulation suggested the existence of at least two types of modulatory proteins: an activating protein in the cytosol of both tissues, and an inhibitory protein associated with placental microsomes. Possible hormonal regulation was investigated in kidneys using in vivo estradiol treatment, but only slight changes in total apyrase activity were observed.

Asunto(s)

Humanos , Animales , Ratas , Apirasa/metabolismo , Riñón/enzimología , Placenta/enzimología , Agregación Plaquetaria , Apirasa/química , Estradiol/farmacología

RESUMEN

The author studied the use of intravenous Propofol for the relief of pain. He demonstrated that Propofol and 10 mg of Lidocaine intravenously decreased moderate or severe pain from 31.6% to 9% and that increasing the dose of Lidocaine did not significantly decrease the pain further. Fentanyl did not produce a statistically significant further diminution of the pain from the level of relief obtained with Propofol.

Asunto(s)

Fentanilo/uso terapéutico , Lidocaína/uso terapéutico , Dolor/tratamiento farmacológico , Propofol/efectos adversos , Adolescente , Adulto , Anciano , Niño , Femenino , Humanos , Inyecciones Intravenosas , Masculino , Persona de Mediana Edad , Dolor/inducido químicamente , Propofol/administración & dosificación

RESUMEN

Se revisaron 66 historias clínicas correspondientes a pacientes ingresados por psoriasis en el período de enero de 1982 a enero de 1983 en el Servicio de Dermatología del hospital provincial clínico-quirúrgico docente "Celia Sánchez Manduley", de Manzanillo. Los pacientes que presentaron recaídas no tuvieron porcentajes relevantes entre los que recibieron tratamiento tópico con Dermovate en relación con el grupo que fue tratado con queratolíticos(AU)

Asunto(s)

Humanos , Psoriasis/complicaciones