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1.
J Cyst Fibros ; 16(3): 418-424, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28284526

RESUMEN

BACKGROUND: Diabetes is common in cystic fibrosis (CF). Glucose can be detected in the airway when the blood glucose is elevated, which favours bacterial growth. We investigated the relationship between dysglycemia and lung pathogens in CF. METHODS: Cross-sectional and prospective analysis of CF patients (N=260) who underwent a 2h-oral glucose tolerance test. Clinical data was collected. RESULTS: Stenotrophomonas maltophilia (S. maltophilia) was the sole bacteria increased in dysglycemic (AGT: 20.2%, CFRD: 21.6%) patients compared to normotolerants (NGT: 8.7%). S. maltophilia positive patients with dysglycemia had more pulmonary exacerbation events compared to NGTs (1.22 vs 0.63, P=0.003). The interaction between S. maltophilia colonisation and glucose tolerance status significantly increases the risk of lower lung function (P=0.003). Its growth was not affected by the evolution of the glucose tolerance after three years follow-up. CONCLUSION: Prevalence of S. maltophilia was higher in dysglycemic patients, supporting the idea that S. maltophilia is a marker of disease severity in CF.


Asunto(s)
Fibrosis Quística , Intolerancia a la Glucosa , Infecciones por Bacterias Gramnegativas , Sistema Respiratorio/microbiología , Infecciones del Sistema Respiratorio , Stenotrophomonas maltophilia/aislamiento & purificación , Adulto , Glucemia/análisis , Canadá/epidemiología , Estudios Transversales , Fibrosis Quística/sangre , Fibrosis Quística/microbiología , Fibrosis Quística/fisiopatología , Femenino , Intolerancia a la Glucosa/sangre , Intolerancia a la Glucosa/diagnóstico , Intolerancia a la Glucosa/microbiología , Infecciones por Bacterias Gramnegativas/sangre , Infecciones por Bacterias Gramnegativas/epidemiología , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Masculino , Prevalencia , Estudios Prospectivos , Infecciones del Sistema Respiratorio/sangre , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/microbiología , Índice de Severidad de la Enfermedad , Estadística como Asunto
2.
Respir Med Case Rep ; 20: 48-50, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-27995056

RESUMEN

BACKGROUND: Patients with Cystic Fibrosis are subject to repeated respiratory tract infections, with recent increasing isolation of unusual pathogens. Ralstonia species have lately been isolated at our institution, an organism historically frequently misidentified as Burkholderia or Pseudomonas. The prevalence of Ralstonia spp. in cystic fibrosis populations has yet to be determined, along with its clinical implications. CASE PRESENTATIONS: Seven patients out of the 301 followed at our cystic fibrosis clinic have had Ralstonia strains identified in their respiratory tract. Most strains identified were multi-drug resistant. After aquisition of Ralstonia spp., the patients' clinical course was characterized by more frequent and more severe respiratory infections along with prolonged hospitalizations, greater decline of lung function, and greater mortality. The mortality rate in this group of patients was 86%. No other factor that could explain such a dramatic evolution was identified upon review of patient data. Some of the strains involved were recognized as clones on Pulse Field Electrophoresis Gel, raising the question of person-to-person transmission. CONCLUSION: New pathogens are identified with the evolution of the microbiota in cystic fibrosis respiratory tracts. In our cohort of patients, acquisition of Ralstonia spp. was associated with dramatic outcomes in terms of disease acceleration and raised mortality rates. It is of critical importance to continue to better define the prevalence and clinical impact of Ralstonia in cystic fibrosis populations.

3.
Pediatr Obes ; 12 Suppl 1: 38-46, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-27863167

RESUMEN

BACKGROUND: Physical activity (PA) during pregnancy might contribute to reduce neonatal adiposity, a predictor of metabolic disturbances. OBJECTIVE: The objective of the study was to evaluate the association between maternal PA intensity and neonatal body composition. METHODS: Maternal PA measured by accelerometry and nutrition were documented during pregnancy, as well as neonatal body composition by dual-energy X-ray absorptiometry following delivery. Associations between PA at 17 and 36 weeks (time spent in moderate PA (MPA), vigorous PA (VPA) status and their interaction) and neonatal body composition were addressed by multivariate regression analyses. RESULTS: From 104 women, 50 (48%) and 16 (18%) performed VPA at 17 and 36 weeks of pregnancy. Performing VPA at either time was associated with a decreased birthweight (BW), while only VPA at 17 weeks decreased neonatal adiposity (fat percentage: -2.3 ± 0.8%, p = 0.003). MPA at 36 weeks was associated with an increased lean mass (2.0 ± 0.8 g per min day-1 , p = 0.012). Significant interactions were found for BW and bone mineral content (BMC). MPA at 17 weeks tended to increase BW, but not BMC, in the no VPA strata. By contrast, high levels of MPA (≥112 min d-1 ) combined with VPA at 17 weeks reduced neonatal BMC and BW compared with no VPA (BMC: -5.4 ± 2.0 g, p = 0.008, BW: -302.8 ± 83.7 g, p = 0.0003). Differences were not significant with low MPA levels. CONCLUSIONS: Exercise intensity modulates neonatal body composition. The long-term significance of a reduced BW, adiposity and BMC with VPA requires further study.


Asunto(s)
Adiposidad/fisiología , Composición Corporal/fisiología , Ejercicio Físico/fisiología , Absorciometría de Fotón , Acelerometría , Adulto , Peso al Nacer , Densidad Ósea , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Embarazo , Análisis de Regresión
4.
J Biol Regul Homeost Agents ; 29(2 Suppl 1): 29-37, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26634585

RESUMEN

Cystic fibrosis is one of the most common fatal genetic diseases (1 in 2500 births). The defect causing the disease is localized on the 7q31 gene, which codifies for the CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) transmembrane protein. CFTR is a chloride channel localized on the epithelial cells of the mucosa of the respiratory tract, pancreatic ducts, biliary tree, intestine, vas deferens and sweat glands. More than 2000 different mutations are currently known; some are prominent or relatively frequent, ranging from one population to another. The most frequent complications of cystic fibrosis are those affecting the bronchial tree. Patients suffer from recurrent lung infections, which involve a progressive loss of lung function. The pulmonary infections are frequent or chronic and limit the quality of life of patients. In addition to being enormously exposed to antibiotics, they have many more opportunities to develop hypersensitivity reactions to these molecules. Only a complete allergy work-up with a detailed analysis of the clinical history, skin tests and provocation test can show if the patient has actually experienced an allergic hypersensitivity reaction. Desensitization is to be considered as a treatment that may help patients benefit from antibiotic treatment in those cases in which they have a proven allergy to a certain molecule.

5.
J Environ Manage ; 95 Suppl: S165-9, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21658837

RESUMEN

The practice of intensive animal production in certain areas has resulted in excessive manure production for the available regional land base. Consequently, there is a need to develop treatment technologies to recover the valuable nutrients that manure contains so that the resulting product can be transported and used as fertilizer on agricultural land. The project presented here used electrodialysis in a dilution/concentration configuration to transfer the manure ammonia in the diluate solution by electromigration to an adjacent solution separated by an ion-exchange membrane under the driving force of an electrical potential. Then, air stripping from the electrodialysis-obtained concentrate solution without pH modification was used to isolate the ammonia in an acidic solution. An optimal process operating voltage of 17.5 V was first determined on the basis of current efficiency and total energy consumption. During the process, the swine manure pH varied from 8.5 to 8.2, values favourable for NH(4)(+) electromigration. Total ammonia nitrogen reached 21,352 mg/L in the concentrate solution, representing approximately seven times the concentration in the swine manure. Further increases in concentration were limited by water transfer from the diluate solution due to electroosmosis and osmosis. Applying vacuum to the concentrate reservoir was found to be more efficient than direct concentrate solution aeration for NH(3) recuperation in the acid trap, given that the ammonia recuperated under vacuum represented 14.5% of the theoretical value of the NH(3) present in the concentrate solution as compared to 6.2% for aeration. However, an excessively low concentrate solution pH (8.6-8.3) limited NH(3)volatilization toward the acid trap. These results suggest that the concentrate solution pH needs to be raised to promote the volatile NH(3) form of total ammonia nitrogen.


Asunto(s)
Amoníaco/análisis , Diálisis/métodos , Estiércol , Nitrógeno/aislamiento & purificación , Porcinos , Aire , Crianza de Animales Domésticos/métodos , Animales , Electroquímica/métodos , Concentración de Iones de Hidrógeno , Vacio , Eliminación de Residuos Líquidos/métodos
6.
Influenza Other Respir Viruses ; 4(4): 171-8, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20629771

RESUMEN

BACKGROUND: During the first wave of A/California/7/2009(H1N1) influenza, high rates of hospitalization in children under 5 years were seen in many countries. Subsequent policies for vaccinating children varied in both type of vaccine and number of doses. In Canada, children 36 months to <10 years received a single dose of 0.25 ml of the GSK adjuvanted vaccine (Arepanrix) equivalent to 1.9 microg HA. Children 6 months to 35 months received two doses as did those 36-119 months with chronic medical conditions. METHOD: We conducted a community-based case-control vaccine effectiveness (VE) review of children under 10 years with influenza like illness who were tested for H1N1 infection at the central provincial laboratory. Laboratory-confirmed influenza was the primary outcome, and vaccination status the primary exposure to assess VE after a single 0.25-ml dose. RESULTS: If vaccination was designated to be effective after 14 days, no vaccinated child had laboratory-confirmed influenza compared to 38% of controls. The VE of 100% was statistically significant for children <10 years of age and <5 years considered separately. If vaccination was considered effective after 10 days, VE dropped to 96% overall but was statistically significant and over 90% in all age subgroups, including those under 36 months. CONCLUSIONS: A single 0.25-ml dose of the GSK adjuvanted vaccine (Arepanrix) protects children against laboratory-confirmed pandemic influenza potentially avoiding any increased reactogenicity associated with second doses. Adjuvanted vaccines offer hope for improved seasonal vaccines in the future.


Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Subtipo H1N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/administración & dosificación , Gripe Humana/prevención & control , Canadá/epidemiología , Estudios de Casos y Controles , Niño , Preescolar , Brotes de Enfermedades , Femenino , Humanos , Esquemas de Inmunización , Lactante , Vacunas contra la Influenza/inmunología , Masculino , Pandemias , Resultado del Tratamiento , Vacunación/estadística & datos numéricos
7.
Ann Surg Oncol ; 17(5): 1414-21, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20131017

RESUMEN

BACKGROUND: Standard of care is to perform a complete lymph node dissection (CLND) in melanoma patients with positive sentinel lymph nodes (SLNs). However, less than 20% will have metastases in non-SLNs. The S classification was described to predict the non-SLN status, hoping to identify a subset of patients who can be spared the CLND. We tried to validate the feasibility and usefulness of this classification. MATERIALS AND METHODS: We performed a retrospective chart review. All melanoma cases between 1996 and 2006 were included, and 359 patients with SLN biopsies were identified. All pathology slides were reviewed with an emphasis on the S classification. RESULTS: There were 365 SLN biopsies performed. A total of 82 patients (22.8%) had positive SLNs, while 277 patients (77.2%) had negative SLNs. There were 22 patients classified as SI, 18 as SII, 37 as SIII, and 5 were unclassified. On CLND, only 10 patients (12.2%) had positive non-SLNs. None of these were classified as SI while 2 patients (11%) were classified as SII and 8 (22%) as SIII. The S category was found to be a predictor of non-SLN status, and this reached statistical significance (P = 0.044). On univariate analysis, only an increasing Breslow depth and ulceration were predictive of a non-SI status. CONCLUSION: Our results suggest that the S classification is easily feasible and predicts the status of non-SLNs. No patient with SI status was found to have additional non-SLN positive nodes. A larger-scale, prospective trial should be done to confirm these results and possibly spare patients the morbidity of CLND with a positive SLN.


Asunto(s)
Ganglios Linfáticos/patología , Melanoma/clasificación , Melanoma/patología , Biopsia del Ganglio Linfático Centinela , Canadá , Estudios de Factibilidad , Femenino , Humanos , Metástasis Linfática , Masculino , Melanoma/cirugía , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos
8.
Australas Radiol ; 50(3): 237-40, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16732821

RESUMEN

We report a target sign on ultrasound and peripheral rim enhancement on gadolinium (Gd)-enhanced MRI images in metastasis to the breast from melanoma. These classic signs, as reported in the liver (ultrasound target sign) and in primary breast cancers (Gd rim enhancement), are probably also of value in cases of metastatic lesions to the breast.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/secundario , Imagen por Resonancia Magnética , Melanoma/patología , Ultrasonografía Mamaria , Adulto , Neoplasias de la Mama/diagnóstico por imagen , Medios de Contraste , Femenino , Humanos
10.
J Exp Bot ; 52(365): 2301-11, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11709580

RESUMEN

Carbohydrate metabolism was investigated during spruce somatic embryogenesis. During the period of maintenance corresponding to the active phase of embryogenic tissue growth, activities of soluble acid invertase and alkaline invertase increased together with cellular glucose and fructose levels. During the same time, sucrose phosphate synthase (SPS) activity increased while sucrose synthase (SuSy) activity stayed constant together with the cellular sucrose level. Therefore, during maintenance, invertases were thought to generate the hexoses necessary for embryogenic tissue growth while SuSy and SPS would allow cellular sucrose to be kept at a constant level. During maturation on sucrose-containing medium, SuSy and SPS activities stayed constant whereas invertase activities were high during the early stage of maturation before declining markedly from the second to the fifth week. This decrease of invertase activities resulted in a decreased hexose:sucrose ratio accompanied by starch and protein deposition. Additionally, carbohydrate metabolism was strongly modified when sucrose in the maturation medium was replaced by equimolar concentrations of glucose and fructose. Essentially, during the first 2 weeks, invertase activities were low in tissues growing on hexose-containing medium while cellular glucose and fructose levels increased. During the same period, SuSy activity increased while the SPS activity stayed constant together with the cellular sucrose level. This metabolism reorganization on hexose-containing medium affected cellular protein and starch levels resulting in a decrease of embryo number and quality. These results provide new knowledge on carbohydrate metabolism during spruce somatic embryogenesis and suggest a regulatory role of exogenous sucrose in embryo development.


Asunto(s)
Metabolismo de los Hidratos de Carbono , Picea/metabolismo , Glucosiltransferasas/metabolismo , Glicósido Hidrolasas/metabolismo , Hexosas/metabolismo , Picea/enzimología , Picea/crecimiento & desarrollo , Proteínas/metabolismo , Semillas/enzimología , Semillas/crecimiento & desarrollo , Semillas/metabolismo , Almidón/metabolismo , Sacarosa/administración & dosificación , Sacarosa/análisis , beta-Fructofuranosidasa
11.
J Exp Bot ; 52(364): 2089-95, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11604447

RESUMEN

An efficient and reproducible procedure for the transformation of white spruce (Picea glauca [Moench] Voss) embryogenic tissues was developed using A. tumefaciens-mediated gene transfer. Rapidly dividing white spruce embryogenic tissues were co-cultivated with disarmed A. tumefaciens strains containing additional copies of the virulence regions from plasmid PToK47. The plasmid pBi121, containing the neomycin phosphotransferase II (nptII) gene providing kanamycin resistance as a selectable marker and the beta-glucuronidase (uidA) reporter gene, was used as binary vector. The highest frequency of transformation (15 transformed tissues g(-1) FW of treated embryogenic tissue) was obtained with 5-d-old tissues grown in liquid medium and co-cultivated with Agrobacterium for 2 d in the same medium but containing 50 microM acetosyringone. Recovery of kanamycin-resistant tissues was improved when tissues were first grown for 10 d on a timentin-containing medium (400 mg l(-1)), to prevent bacterial overgrowth, before application of the selection pressure. After 6 weeks on kanamycin-selection medium, resistant tissues were obtained and showed stable uidA expression. The presence of the transgenes was demonstrated by PCR analysis and their integration into the genome was confirmed by Southern hybridization. Transgenic plants were regenerated from transformed tissues within 4 months after co-culture.


Asunto(s)
Agrobacterium tumefaciens/genética , Picea/genética , Plantas Modificadas Genéticamente , Agrobacterium tumefaciens/efectos de los fármacos , Farmacorresistencia Microbiana , Regulación Bacteriana de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Kanamicina/farmacología , Picea/embriología , Picea/microbiología , Plásmidos/genética , Semillas/embriología , Semillas/genética , Semillas/microbiología , Transformación Genética/efectos de los fármacos
12.
J Rehabil Med ; 33(5): 230-4, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11585155

RESUMEN

In this study, we investigated corticospinal excitability during mental simulation of a leg extension movement with the technique of transcranial magnetic stimulation. Motor evoked potentials were recorded in both knee extensors (quadriceps) and flexors (biceps femoris) in 19 trained participants (healthy volunteers). The amplitude and latency of motor evoked potentials were compared in three conditions: (1) at rest, (2) during motor imagery, and (3) at rest, immediately after motor imagery. The results showed a significant effect (p < 0.001) of conditions on motor evoked potentials amplitude in the quadriceps but not in the biceps femoris. During motor imagery, the size of motor evoked potentials in the quadriceps increased significantly (p < 0.001) compared with rest and post-imagery conditions. Changes in motor evoked potentials latency across conditions were not significant, however. These results are consistent with previous studies in the upper limb and suggest that corticospinal excitability can be enhanced during motor imagery to facilitate responses in specific lower limb muscles.


Asunto(s)
Rodilla/inervación , Rodilla/fisiología , Movimiento/fisiología , Tractos Piramidales/fisiología , Adolescente , Adulto , Canadá , Terapia por Estimulación Eléctrica , Electromiografía , Potenciales Evocados Motores/fisiología , Femenino , Humanos , Magnetismo , Masculino , Relajación Muscular/fisiología , Valores de Referencia , Descanso/fisiología
13.
J Biol Chem ; 276(41): 38052-60, 2001 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-11498541

RESUMEN

Amino acids have emerged as potent modulators of the mTOR/p70 S6 kinase pathway. The involvement of this pathway in the regulation of insulin-stimulated glucose transport was investigated in the present study. Acute exposure (1 h) to a balanced mixture of amino acids reduced insulin-stimulated glucose transport by as much as 55% in L6 muscle cells. The effect of amino acids was fully prevented by the specific mTOR inhibitor rapamycin. Time course analysis of insulin receptor substrate 1 (IRS-1)-associated phosphatidylinositol (PI) 3-kinase activity revealed that incubation with amino acids speeds up its time-dependent deactivation, leading to a dramatic suppression (-70%) of its activity after 30 min of insulin stimulation as compared with its maximal activation (5 min of stimulation). This accelerated deactivation of PI 3-kinase activity in amino acid-treated cells was associated with a concomitant and sustained increase in the phosphorylation of p70 S6 kinase. In marked contrast, inhibition of mTOR by rapamycin maintained PI 3-kinase maximally activated for up to 30 min. The marked inhibition of insulin-mediated PI 3-kinase activity by amino acids was linked to a rapamycin-sensitive increase in serine/threonine phosphorylation of IRS-1 and a decreased binding of the p85 subunit of PI 3-kinase to IRS-1. Furthermore, amino acids were required for the degradation of IRS-1 during long term insulin treatment. These results identify the mTOR/p70 S6 kinase signaling pathway as a novel modulator of insulin-stimulated glucose transport in skeletal muscle cells.


Asunto(s)
Aminoácidos/metabolismo , Resistencia a la Insulina , Insulina/metabolismo , Músculo Esquelético/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Quinasas S6 Ribosómicas/metabolismo , Transducción de Señal , Transporte Biológico , Línea Celular , Activación Enzimática , Retroalimentación , Glucosa/metabolismo , Hidrólisis , Proteínas Sustrato del Receptor de Insulina , Músculo Esquelético/citología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-akt , Serina-Treonina Quinasas TOR , Tirosina/metabolismo
14.
Diabetes ; 50(8): 1901-10, 2001 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-11473054

RESUMEN

The cellular mechanism by which high-fat feeding induces skeletal muscle insulin resistance was investigated in the present study. Insulin-stimulated glucose transport was impaired ( approximately 40-60%) in muscles of high fat-fed rats. Muscle GLUT4 expression was significantly lower in these animals ( approximately 40%, P < 0.05) but only in type IIa-enriched muscle. Insulin stimulated the translocation of GLUT4 to both the plasma membrane and the transverse (T)-tubules in chow-fed rats. In marked contrast, GLUT4 translocation was completely abrogated in the muscle of insulin-stimulated high fat-fed rats. High-fat feeding markedly decreased insulin receptor substrate (IRS)-1-associated phosphatidylinositol (PI) 3-kinase activity but not insulin-induced tyrosine phosphorylation of the insulin receptor and IRS proteins in muscle. Impairment of PI 3-kinase function was associated with defective Akt/protein kinase B kinase activity (-40%, P < 0.01) in insulin-stimulated muscle of high fat-fed rats, despite unaltered phosphorylation (Ser473/Thr308) of the enzyme. Interestingly, basal activity of atypical protein kinase C (aPKC) was elevated in muscle of high fat-fed rats compared with chow-fed controls. Whereas insulin induced a twofold increase in aPKC kinase activity in the muscle of chow-fed rats, the hormone failed to further increase the kinase activity in high fat-fed rat muscle. In conclusion, it was found that GLUT4 translocation to both the plasma membrane and the T-tubules is impaired in the muscle of high fat-fed rats. We identified PI 3-kinase as the first step of the insulin signaling pathway to be impaired by high-fat feeding, and this was associated with alterations in both Akt and aPKC kinase activities.


Asunto(s)
Grasas de la Dieta/farmacología , Insulina/farmacología , Proteínas de Transporte de Monosacáridos/metabolismo , Proteínas Musculares , Músculo Esquelético/metabolismo , Proteína Quinasa C/metabolismo , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas/metabolismo , Animales , Glucemia/metabolismo , Membrana Celular/metabolismo , Transportador de Glucosa de Tipo 4 , Insulina/sangre , Proteínas Sustrato del Receptor de Insulina , Resistencia a la Insulina/fisiología , Isoenzimas , Cinética , Masculino , Microtúbulos/metabolismo , Músculo Esquelético/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas/metabolismo , Transporte de Proteínas/efectos de los fármacos , Proteínas Proto-Oncogénicas c-akt , Ratas , Ratas Wistar
15.
Am J Physiol Endocrinol Metab ; 281(1): E62-71, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11404223

RESUMEN

In the present study, we tested the hypothesis that fish protein may represent a key constituent of fish with glucoregulatory activity. Three groups of rats were fed a high-fat diet in which the protein source was casein, fish (cod) protein, or soy protein; these groups were compared with a group of chow-fed controls. High-fat feeding led to severe whole body and skeletal muscle insulin resistance in casein- or soy protein-fed rats, as assessed by the euglycemic clamp technique coupled with measurements of 2-deoxy-D-[(3)H]glucose uptake rates by individual tissues. However, feeding cod protein fully prevented the development of insulin resistance in high fat-fed rats. These animals exhibited higher rates of insulin-mediated muscle glucose disposal that were comparable to those of chow-fed rats. The beneficial effects of cod protein occurred without any reductions in body weight gain, adipose tissue accretion, or expression of tumor necrosis factor-alpha in fat and muscle. Moreover, L6 myocytes exposed to cod protein-derived amino acids showed greater rates of insulin-stimulated glucose uptake compared with cells incubated with casein- or soy protein-derived amino acids. These data demonstrate that feeding cod protein prevents obesity-induced muscle insulin resistance in high fat-fed obese rats at least in part through a direct action of amino acids on insulin-stimulated glucose uptake in skeletal muscle cells.


Asunto(s)
Grasas de la Dieta/farmacología , Proteínas en la Dieta/farmacología , Peces/metabolismo , Resistencia a la Insulina/fisiología , Músculo Esquelético/fisiología , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/metabolismo , Aminoácidos/farmacología , Animales , Células Cultivadas , Desoxiglucosa/metabolismo , Dieta , Glucosa/metabolismo , Técnica de Clampeo de la Glucosa , Cinética , Masculino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Miocardio/metabolismo , Ratas , Ratas Wistar , Factor de Necrosis Tumoral alfa/biosíntesis
16.
J Exp Bot ; 52(357): 761-9, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11413212

RESUMEN

To examine the possible relationship between ethylene and the capacity of embryogenic cell lines to produce mature somatic embryos of black spruce (Picea mariana (Mill.) B.S.P.), two embryogenic cell lines which exhibit different maturation capacities were used to analyse ethylene biosynthesis and that of its immediate precursor, 1-aminocyclopropane-1- carboxylic acid (ACC). Several compounds known to alter ethylene metabolism were also evaluated for their effect on the number of mature somatic embryos produced. The results showed that in the high capacity cell line, ethylene production and endogenous ACC pools were less than in the low capacity cell line. It was also demonstrated that limiting ethylene biosynthesis by adding inhibitors of ethylene biosynthesis or its physiological action to the maturation medium promoted somatic embryo production for the low capacity cell line. Conversely, lowering ethylene biosynthesis reduced the number of somatic embryos in the high capacity cell line. These results were further substantiated by the finding that the effects of amino-oxyacetic acid (AOA), an inhibitor of ethylene biosynthesis, were partially reversed by adding ethylene to both embryogenic cell lines. It is concluded that ethylene is implicated in somatic embryogenesis of black spruce and that the low capacity cell line had excess, i.e. supraoptimal, ethylene production, whereas the high capacity cell line had nearly optimal ethylene production. The relationship between ethylene and other phytohormones, and the possible effects of the interaction between ethylene and polyamines on the maturation of the somatic embryos are discussed.


Asunto(s)
Etilenos/metabolismo , Semillas/citología , Árboles/embriología , Aminoácidos Cíclicos/farmacología , Ácido Aminooxiacético/farmacología , Línea Celular , Etilenos/antagonistas & inhibidores , Semillas/metabolismo , Nitrato de Plata/farmacología , Árboles/metabolismo
17.
Am J Hypertens ; 14(6 Pt 2): 38S-43S, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11411764

RESUMEN

In the past few years, a great deal of interest has been focused on the possibility that angiotensin peptides could have direct effects on target tissues independent of their hemodynamic effects. In addition, there has been much speculation on the potential biological roles of angiotensin peptides other than angiotensin II. Unfortunately, a direct test of these possibilities in whole animals has been difficult due to limitations in existing biological systems. In this review, we describe the characteristics of an engineered protein capable of directing the production of a wide variety of peptides to specific tissues and cell types in transgenic animals and discuss its potential applications.


Asunto(s)
Angiotensinas/fisiología , Fragmentos de Péptidos/fisiología , Ingeniería de Proteínas , Animales , Furina , Humanos , Proteínas de Transporte de Membrana , Péptidos/metabolismo , Subtilisinas/metabolismo
18.
Can J Surg ; 44(6): 428-31, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11764875

RESUMEN

OBJECTIVE: To determine the effectiveness of sentinel lymph-node (SLN) biopsy for melanoma of the trunk and extremities. DESIGN: Case series review. SETTING: Royal Victoria Hospital, a Canadian university hospital. PATIENTS: Thirty-six patients (18 women and 18 men) seen between October 1996 and December 1998 with melanoma 1 mm or more in thickness with clinically negative lymph-node basins. Follow-up was 396 days. INTERVENTIONS: SLN biopsy. Technetium-99m filtered sulfur colloid (0.5 mCi) was injected intradermally around the melanoma or the excision scar 10 to 15 minutes before the surgical skin preparation. The identification of the SLN(s) was done with a hand-held gamma probe. Local anesthesia was used mostly for inguinal SLN biopsy whereas general anesthesia was usually required for axillary SLN biopsy. Preoperative lymphoscintigraphy was used only for trunk melanomas. OUTCOME MEASURES: Morbidity, successful identification of the sentinel node and locoregional recurrence. RESULTS: The mean age of patients at diagnosis was 53.4 years (range from 22-76 yr). The melanomas were distributed between the lower extremities (20 patients), upper extremities (8 patients) and trunk (8 patients). The mean Breslow thickness was 2.35 mm (range from 1-8 mm). Lymphoscintigraphy accurately localized the lymph-node drainage basin for trunk melanomas. In 1 patient the SLN could not be identified because the radiocolloid failed to migrate (failure rate 2.8%). The average number of SLNs removed was 1.97. Eight patients (22%) had sentinel nodes positive for malignant disease. The postoperative complication rate was 8.5%. Seven of 8 patients with positive SLNs underwent a complete node dissection (1 patient refused). Of the completion dissections only 2 patients had positive non-SLNs. All patients with positive nodes received interferon alpha-2b as adjuvant treatment. At follow-up, 34 patients are alive with no evidence of disease, 1 patient with a positive SLN is alive with distant metastatic disease and 1 patient with a negative SLN is dead of disseminated disease. CONCLUSION: SLN biopsy is a feasible technique with an acceptable failure rate and is thus a useful tool in the surgical management of melanoma.


Asunto(s)
Melanoma/patología , Biopsia del Ganglio Linfático Centinela , Neoplasias Cutáneas/patología , Adulto , Anciano , Femenino , Humanos , Ganglios Linfáticos/diagnóstico por imagen , Metástasis Linfática , Masculino , Persona de Mediana Edad , Cintigrafía , Radiofármacos , Biopsia del Ganglio Linfático Centinela/efectos adversos , Azufre Coloidal Tecnecio Tc 99m
19.
J Cardiovasc Pharmacol ; 36(5 Suppl 1): S28-9, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11078327

RESUMEN

Endothelin (ET) is a 21 amino acid peptide produced following the cleavage of its precursor, big ET, by a metalloprotease, the endothelin-converting enzyme (ECE). In the study reported here we determined the minimal peptide sequence of big ET necessary for enzyme recognition and cleavage at the P1-P1' site. Furthermore, we have explored the role of the amino acids found at the boundaries of the cleavage site. To reach these goals. we synthesized a series of fragments, all containing the P1-P1' cleavage site, Trp21-Val22. Following the incubation of peptide fragments with a partly purified bovine ECE preparation and after analyzing the cleavage pattern by high-performance liquid chromatography (HPLC), we were able to identify big ET(18-23) amide as the minimal peptide core recognized and cleaved by the enzyme. This hydrolysis was inhibited by phosphoramidon but not by thiorphan, a characteristic of the ECE metalloprotease. However, none of the shorter peptides was able to inhibit the cleavage of big ET-1 by ECE, suggesting that they are not recognized by the enzyme. Particularly, it appears that aspartic acid 18 is a key residue for the recognition phenomenon. The delineation of the minimal structure will be a useful tool to further characterize ECE.


Asunto(s)
Ácido Aspártico Endopeptidasas/metabolismo , Endotelinas/metabolismo , Fragmentos de Péptidos/metabolismo , Precursores de Proteínas/metabolismo , Animales , Bovinos , Endotelina-1 , Enzimas Convertidoras de Endotelina , Endotelinas/química , Metaloendopeptidasas , Precursores de Proteínas/química , Relación Estructura-Actividad
20.
J AAPOS ; 4(3): 154-7, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10849391

RESUMEN

BACKGROUND: It has been suggested that a decrease in distance stereoacuity in patients with intermittent exotropia is a good indicator of diminishing control. However, there has been no adequate explanation for this reported reduction in distance stereoacuity in these patients. We postulate that the decrease in stereoacuity is related to blurred visual acuity created by an increasing demand on accommodation, which these patients use in an attempt to control the exodeviation. This can best be assessed by measuring binocular visual acuity (BVA). Analysis of BVA could provide a useful clinical tool to evaluate control measures used by patients with intermittent exotropia. METHODS: A prospective study of patients with intermittent exotropia, ranging in age from 6 to 60 years, was performed. Only those patients with the presence of either basic or divergence excess (simulated or true) type exodeviation were included in the study. The data analysis included the age of these patients, age at onset of the deviation, monocular and binocular visual acuity, oculomotor and fusional status, and near and distance stereoacuity. RESULTS: Data from 36 patients show that the measurements of BVA correlated well with a corresponding loss of distance stereoacuity but not with the size of the deviation. CONCLUSION: The decrease of stereoacuity reported in patients with exotropia can be explained by increased accommodation and decreased distance BVA. This measurement can be a simple method of quantifying the fusional control of patients with intermittent exotropia.


Asunto(s)
Exotropía/diagnóstico , Pruebas de Visión/métodos , Visión Binocular , Agudeza Visual , Acomodación Ocular , Adolescente , Adulto , Niño , Exotropía/fisiopatología , Exotropía/cirugía , Humanos , Persona de Mediana Edad , Músculos Oculomotores/patología , Músculos Oculomotores/fisiopatología , Músculos Oculomotores/cirugía , Pronóstico , Estudios Prospectivos
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