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1.
Sci Rep ; 9(1): 18889, 2019 12 11.
Artículo en Inglés | MEDLINE | ID: mdl-31827137

RESUMEN

Intervertebral disc (IVD) degeneration and consequent low back pain (LBP) are common and costly pathological processes that require improved treatment strategies. Transient Receptor Potential (TRP) channels constitute a family of multimodal ion channels that have recently emerged as contributors to disc pathologies and were thus proposed as potential therapeutic targets, although limited data on their presence and function in the IVD exist. The purpose of this study was to determine the mRNA and protein expression of TRP channels in non-degenerated and degenerated human IVD tissue (with different pain intensity and chronicity) using gene array, conventional qPCR and immunohistochemistry. We could demonstrate that 26 out of 28 currently known TRP channels are expressed in the IVD on the mRNA level, thereby revealing novel therapeutic candidates from the TRPC, TRPM and TRPML subfamilies. TRPC6, TRPM2 and TRPML1 displayed enhanced gene and protein expression in degenerated IVDs as compared to non-degenerated IVDs. Additionally, the gene expression of TRPC6 and TRPML1 was influenced by the IVD degeneration grade. Pain intensity and/or chronicity influenced the gene and/or protein expression of TRPC6, TRPM2 and TRML1. Interestingly, decreased gene expression of TRPM2 was observed in patients treated with steroids. This study supports the importance of TRP channels in IVD homeostasis and pathology and their possible application as pharmacological targets for the treatment of IVD degeneration and LBP. However, the exact function and activation of the highlighted TRP channels will have to be determined in future studies.


Asunto(s)
Dolor de Espalda/metabolismo , Regulación de la Expresión Génica , Degeneración del Disco Intervertebral/metabolismo , Disco Intervertebral/metabolismo , Canales de Potencial de Receptor Transitorio/metabolismo , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Dolor de Espalda/genética , Dolor de Espalda/patología , Femenino , Humanos , Disco Intervertebral/patología , Degeneración del Disco Intervertebral/genética , Degeneración del Disco Intervertebral/patología , Masculino , Persona de Mediana Edad , Canales de Potencial de Receptor Transitorio/genética
3.
ISA Trans ; 64: 241-246, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27329853

RESUMEN

The knowledge of the broken rotor bars characteristic frequencies and amplitudes has a great importance for all related diagnostic methods. The monitoring of motor faults requires a high resolution spectrum to separate different frequency components. The Discrete Fourier Transform (DFT) has been widely used to achieve these requirements. However, at low slip this technique cannot give good results. As a solution for these problems, this paper proposes an efficient technique based on a neural network approach and Hilbert transform (HT) for broken rotor bar diagnosis in induction machines at low load. The Hilbert transform is used to extract the stator current envelope (SCE). Two features are selected from the (SCE) spectrum (the amplitude and frequency of the harmonic). These features will be used as input for neural network. The results obtained are astonishing and it is capable to detect the correct number of broken rotor bars under different load conditions.


Asunto(s)
Análisis de Falla de Equipo/métodos , Redes Neurales de la Computación , Algoritmos , Simulación por Computador , Bases de Datos Factuales , Análisis de Fourier , Aprendizaje Automático
4.
J Thromb Haemost ; 14(4): 807-14, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26792007

RESUMEN

BACKGROUND: Infections after diagnosis of primary chronic immune thrombocytopenia (cITP) have mostly been connected to the immunomodulation treatment. Infections may trigger autoimmune diseases and may be a complication of an already impaired immune system. OBJECTIVES: To investigate the association of cITP with infection before diagnosis. We also estimated the incidence of cITP based on the new definition by the International ITP Working Group. METHODS: We identified 1087 adults with primary cITP between 2006 and 2012 using the Swedish Patient Register. Data on infections not already associated with secondary ITP were also retrieved from the register. The standardized incidence ratios (SIRs), using the rates from the general population, and 95% confidence intervals (CIs) were estimated as a measure of relative risk. We used data from the Prescribed Drug Register to estimate SIR for anti-infective treatment. RESULTS: The incidence of cITP was 2.30 per 100 000 person-years (95% CI, 2.15-2.45). cITP was associated with an increased risk of serious infections requiring inpatient or outpatient care within 5 years before cITP diagnosis (SIR = 8.74; 95% CI, 7.47-10.18). Higher magnitude SIRs were observed for candidiasis, viral infection at an unspecified site and acute upper respiratory infections. For anti-infective drugs the SIR was 1.37 (1.25-1.50) and the highest SIRs were observed for amoxicillin, macrolides, nitrofurantoin and antivirals. CONCLUSION: Patients with cITP have increased risks of infection and anti-infective treatments before their cITP diagnosis, with a more marked risk for candidiasis and viral infections. The findings indicate that infection is not only related to the immunomodulation treatment but also to the disease itself.


Asunto(s)
Infecciones/complicaciones , Púrpura Trombocitopénica Idiopática/complicaciones , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Estudios de Cohortes , Susceptibilidad a Enfermedades , Femenino , Humanos , Sistema Inmunológico , Inmunosupresores/uso terapéutico , Incidencia , Infecciones/epidemiología , Infecciones/etiología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Púrpura Trombocitopénica Idiopática/epidemiología , Púrpura Trombocitopénica Idiopática/etiología , Sistema de Registros , Riesgo , Suecia , Adulto Joven
5.
Br J Ophthalmol ; 99(6): 773-7, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25563765

RESUMEN

AIMS: The aim of this study was to assess the efficacy and safety of pre-Descemet's membrane (DM) sutures associated with intracameral air injection for management of acute corneal hydrops associated with keratoconus. METHODS: We carried out a retrospective interventional study of seven consecutive cases. Three to seven pre-DM sutures with 10-0 nylon were applied perpendicularly to the tear as close as possible to DM, under general anaesthesia. An air bubble was injected into the anterior chamber at the end of each procedure. RESULTS: Corneal oedema began to decrease from day 1 after surgery in all our patients. Best-corrected visual acuity progressed from 2.13 to 1.65 logMar (p=0.031) 1 month after surgery, and from 2.13 to 0.84 logMar (p=0.016) 2 months after surgery. The mean corneal thickness measured by anterior segment optical coherence tomography decreased from 1472 µm (range 689-2770 µm) on day 0 to 909 µm (range 484-1640 µm) on day 1 (p=0.016), 716 µm (range 484-1380 µm) on day 15 (p=0.016) and 528 µm (range 404-618 µm) 1 month after surgery. CONCLUSIONS: Our results suggest that intrastromal pre-DM sutures and intracameral air injection could promptly restore imperviousness of posterior stroma. This technique seems to be a safe and useful procedure to shorten acute corneal hydrops.


Asunto(s)
Edema Corneal/cirugía , Lámina Limitante Posterior/cirugía , Endotaponamiento , Queratocono/complicaciones , Técnicas de Sutura , Suturas , Enfermedad Aguda , Adolescente , Adulto , Aire , Terapia Combinada , Edema Corneal/diagnóstico , Edema Corneal/etiología , Lámina Limitante Posterior/lesiones , Femenino , Humanos , Queratocono/diagnóstico , Masculino , Nylons , Estudios Retrospectivos , Rotura/prevención & control , Tomografía de Coherencia Óptica , Resultado del Tratamiento , Agudeza Visual/fisiología , Adulto Joven
6.
Pak J Biol Sci ; 15(3): 132-40, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-22866543

RESUMEN

The effect of plant growth-promoting Rhizobacteria (PGPR) and exogenous application of compatible solutes on seed germination and root concentrations of sodium and potassium of two wheat varieties (Triticum durum L.) were evaluated under saline stress. In this experiment, Azotobacter vinelandii strain DSM85, glycine betaine and proline were used. Inoculated seeds for each variety were placed on Whatman paper in 9 cm Petri dishes containing 15 mL of distilled water or NaCl solutions at various concentrations (control, 100, 200, 300 mM) supplemented with or without glycine betaine (GB) or proline at 5 mM. The results indicated that addition of proline (5 mM) stimulated the production of indol acetic acid and the growth of A. vinelandii at 200 and 300 mM NaCl, respectively. The germination rate index and the germination final percentage decreased significantly (p < 0.05) with increasing salinity level. The germination was significantly diminished at 300 mM with significant variation among varieties and Waha variety had higher germination percentage than Bousselam variety. Inoculation of seeds by A. vinelandii and exogenous application of proline had significantly positive effect on the germination at this concentration of NaCl. The rate of accumulation of Na+ in roots was important at 100 mM and increased at 200 mM. The concentration of K+ decreased when salinity increased. The effect of inoculation or inoculation with proline decreased the accumulation of Na' and reduced the loss of K+ under salt stress. From the present study we can conclude that the use of A. vinelandii strain DSM85 and external application of low concentrations of proline on seeds might be considered as a strategy for the protection of plants under saline stress.


Asunto(s)
Azotobacter vinelandii/metabolismo , Raíces de Plantas/metabolismo , Triticum/genética , Bacterias/metabolismo , Betaína/química , Germinación , Ácidos Indolacéticos/química , Raíces de Plantas/microbiología , Potasio/química , Prolina/química , Prolina/genética , Salinidad , Semillas/metabolismo , Semillas/microbiología , Sodio/química , Cloruro de Sodio/farmacología , Triticum/microbiología , Agua
7.
Pak J Biol Sci ; 15(6): 267-76, 2012 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-24175423

RESUMEN

The use of microbial technology in agriculture is expanding quickly with the identification of new bacterial strains which are more effective in promoting the growth of plants. The rhizobacteria that promote the growth of plants can have a positive effect on the productivity of crops especially when subjected to salt stress. A nitrogen-fixing bacterium was isolated from the wheat rhizosphere of an arid region. The strain was identified on the basis of tests API20E and 16S rRNA sequencing, as Pantoea agglomerans lma2. This strain degraded several carbon sources: sugars (fructose, ribose, dextrin, salicin...), lipids (lecithin, tributyrin and tween 80), proteins (gelatin, casein), grew on KCN and could grow from pH 4 to 8 and had an optimum at pH 7. The growth temperature showed a maximum at 30 degrees C and the bacteria could tolerate from 4 to 41 degrees C and the growth rate was higher when the NaCl concentration was between 100 and 300 mM. The performance of activities enhancing the growth of plants of P. agglomerans lma2 was significantly better in the presence of salt. Rates of Indole Acetic Acid (IAA), siderophores production and solubilization of phosphate increased between 100 and 400 mM NaCl compared to the control without salt. The maximum values were saved to 300 mM for the production of siderophores (18.32%) and solubilization of phosphate (1061.49 microg mL(-1)) and 100 mM for the production of IAA (161 microg mL(-1)). A significant correlation existed between these three activities. These results showed that P. agglomerans lma2 with its Plant Growth Promoting Rhizobacteria (PGPR) and halophilic properties could constitute a good fertilizer in arid and saline zone.


Asunto(s)
Proteínas Bacterianas/fisiología , Pantoea/fisiología , Desarrollo de la Planta , Rhizobium/fisiología , Proteínas Bacterianas/genética , Concentración de Iones de Hidrógeno , Ácidos Indolacéticos/metabolismo , Fijación del Nitrógeno , Pantoea/genética , Pantoea/aislamiento & purificación , ARN Ribosómico 16S/genética , Sideróforos/metabolismo , Cloruro de Sodio , Estrés Fisiológico , Temperatura
8.
FASEB J ; 23(5): 1521-8, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19126595

RESUMEN

Low birth weight (LBW) followed by accelerated postnatal growth is associated with increased risk of developing age-associated diseases such as type 2 diabetes. Gestational protein restriction in rats causes LBW, beta-cell dysfunction, and reduced longevity. These effects may be mediated by accelerated cellular aging. This study tested the hypothesis that LBW followed by rapid postnatal catch-up growth leads to islet telomere shortening through alterations in antioxidant defense capacity, stress/senescence marker proteins, and DNA repair mechanisms at the gene expression level. We used our rat model of gestational protein restriction (recuperated offspring) and control offspring. Southern blotting revealed shorter (P<0.001) islet telomeres in recuperated animals compared to controls. This was associated with increased expression of peroxiredoxin 1 (P<0.05), peroxiredoxin 3 (P<0.01), and heme oxygenase-1 (HO-1) (P<0.05), which are up-regulated under stress conditions. MnSOD expression was significantly (P<0.05) decreased in recuperated offspring, suggesting partial impairment of mitochondrial antioxidant defenses. Markers of cellular senescence p21 and p16 were also increased (P<0.01 and P<0.05, respectively) in the recuperated group. We conclude that maternal diet influences expression of markers of cellular stress and telomere length in pancreatic islets. This may provide a mechanistic link between early nutrition and growth and type 2 diabetes.


Asunto(s)
Senescencia Celular/fisiología , Islotes Pancreáticos/citología , Fenómenos Fisiologicos Nutricionales Maternos , Deficiencia de Proteína/complicaciones , Telómero/metabolismo , Animales , Reparación del ADN/fisiología , Femenino , Perfilación de la Expresión Génica , Embarazo , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo
9.
Ann Biol Clin (Paris) ; 64(6): 565-73, 2006.
Artículo en Francés | MEDLINE | ID: mdl-17162259

RESUMEN

Iron deficiency (ID) is the most common nutritional deficiency worldwide especially among young children, women in pregnancy and breastfeeding. This study was undertaken to assess the prevalence of ID in 1288 pupil ranging in age from 11 to 14 years. Haemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular Hb (MCH), serum iron (Fe) serum transferrin (Trf), serum ferritin (Ft) and an inflammtory proteic profil (IPP) were measured. The IPP combines the analysis of protein variations: protein results are converted in percent of normal values referenced for the technique used. It has been suggested that on the protein profile, an increase in serum transferrin level compared to a normal serum albumin level (DAT: difference albumin-transferrin), appears early in the course of ID. Iron deficiency was defined by a low serum ferritin (< 15 ng/mL) and/or a pathologic DAT (> 28%). Approximately, 33.8% of children had Ft < 15 ng/mL and 12,8% had DAT > 28% while ferritin values were in the normal range. Diagnosis performance (sensitivity, specificity and diagnosis efficacy) of ferritin and DAT were compared to the performance of high serum transferrin receptor (sTfR) values in 2 populations presenting or not a biological inflammation. Only the diagnosis efficacy of DAT was constant in both situations. In conclusion, the serum ferritin concentration is the first indicator of body storage iron identifying ID, however normal or elevated values of ferritin may be difficult to interpret particulary in the presence of inflammation. sTfR and DAT values are thus reliable indicators of ID in such circumstances.


Asunto(s)
Anemia Ferropénica/sangre , Anemia Ferropénica/diagnóstico , Albúmina Sérica/metabolismo , Transferrina/metabolismo , Adolescente , Anemia Ferropénica/epidemiología , Niño , Femenino , Hemoglobinas/análisis , Humanos , Hierro/sangre , Masculino , Túnez/epidemiología
10.
Diabetologia ; 46(11): 1497-511, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-13680128

RESUMEN

AIMS/HYPOTHESIS: Fetal undernutrition can result in intrauterine growth restriction and increased incidence of Type 2 diabetes mellitus. Intrauterine malnutrition in form of an isocaloric low-protein diet given to female rats throughout gestation decreases islet-cell proliferation, islet size and pancreatic insulin content, while increasing the apoptotic rate and sensitivity to nitrogen oxide and interleukin-1beta. Hence, the influence of a low-protein diet on the development of beta-cells and islets could also be of interest for the pathogenesis of Type 1 and Type 2 diabetes mellitus. We hypothesise that the effects of a low-protein diet in utero are caused by intrauterine programming of beta-cell gene expression. METHODS: Pregnant Wistar rats were fed a low-protein diet (8% protein) or a control diet (20% protein) throughout gestation. At day 21.5 of gestation fetal pancreata were removed, digested and cultured for 7 days. Neoformed islets were collected and analysed by proteome analysis comprising 2-dimensional gel electrophoresis and mass spectrometry. RESULTS: A total of 2810 different protein spots were identified, 70 of which were changed due to the low-protein diet. From 45 of the changed protein spots, identification was obtained by mass spectrometry (64% success rate). Proteins induced by the low-protein diet were grouped according to their biological functions, e.g. cell cycle and differentiation, protein synthesis and chaperoning. CONCLUSIONS/INTERPRETATION: Our study offers a possible explanation of the alterations induced by a low-protein diet in islets. It shows that in Wistar rats the intrauterine milieu could program islet gene expression in ways unfavourable for the future of the progeny. This could be important for our understanding of the development of Type 1 and Type 2 diabetes mellitus.


Asunto(s)
Dieta con Restricción de Proteínas , Islotes Pancreáticos/embriología , Preñez/fisiología , Desnutrición Proteico-Calórica/embriología , Proteoma/genética , Animales , Células Cultivadas , Femenino , Edad Gestacional , Embarazo , Ratas , Ratas Endogámicas , Ratas Endogámicas WF , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
11.
Nucleic Acids Res ; 31(5): 1576-83, 2003 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-12595567

RESUMEN

Telomeres, the non-coding sequences at the ends of chromosomes, in the absence of telomerase, progressively shorten with each cell division. Shortening of telomeres can induce cell cycle arrest and apoptosis. The aim of this study was to investigate age- and gender-related changes in telomere length in the rat and to detect possible tissue- specific rates of telomere shortening. Changes with age in telomere lengths were assessed by Southern blotting in the kidney, pancreas, liver, lung and brain of male and female rats. We determined the percentage of telomeres in various molecular size regions rather than measuring the average telomere length. The latter was unable to detect telomere shortening in the tissues. The percentage of short telomeres increased with age in the kidney, liver, pancreas and lung of both males and females, but not in the brain. Males had shorter telomeres than females in all organs analysed except the brain, where the lengths were similar. These findings indicate that telomeres shorten in the rat kidney, liver, pancreas and the lung in an age-dependent manner. These data also provide a novel mechanism for the gender-related differences in lifespan and suggest a tissue-specific regulation of telomere length during development and ageing in the rat.


Asunto(s)
Envejecimiento/fisiología , Telómero/metabolismo , Animales , Animales Recién Nacidos , Southern Blotting , Encéfalo/metabolismo , ADN/genética , Femenino , Riñón/metabolismo , Hígado/metabolismo , Pulmón/metabolismo , Masculino , Páncreas/metabolismo , Ratas , Ratas Wistar , Factores Sexuales , Telómero/genética , Factores de Tiempo
12.
J Nutr ; 131(5): 1555-9, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11340115

RESUMEN

Previous studies indicate that insulin secretion from the fetuses of dams fed a low protein (LP) diet is reduced in response to leucine or arginine. The aim of this study was to locate the defect in the insulin secretion pathway induced by a LP diet during gestation. The effects of various secretagogues acting at different levels of the insulin secretion cascade were investigated in vitro in fetal islets from dams fed either a normal or a LP diet during pregnancy. Insulin content, insulin secretion and the cAMP content were then measured. Although insulin content of LP islets did not differ from that of control islets, insulin secretion from LP fetal islets was reduced when challenged by amino acids or cAMP enhancers. This reduction did not appear to be related solely to an altered islet cAMP content. An impairment of insulin secretion remained after stimulation of fetal LP islets with either metabolic or nonmetabolic secretagogues. The insulin secretion by LP islets was restored to normal, however, with barium or cytochalasin-B. These findings demonstrate that an in utero isocaloric LP diet impairs insulin secretion of the fetus. This alteration is located at the exocytosis step in the insulin secretion cascade and not in the insulin pool of the beta cell.


Asunto(s)
Proteínas en la Dieta/farmacología , Feto/metabolismo , Insulina/metabolismo , Islotes Pancreáticos/efectos de los fármacos , Animales , Células Cultivadas , Proteínas en la Dieta/administración & dosificación , Femenino , Secreción de Insulina , Islotes Pancreáticos/metabolismo , Embarazo , Ratas , Ratas Wistar
13.
Lett Appl Microbiol ; 32(4): 243-7, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11298934

RESUMEN

AIMS: Detection and identification of new antagonistic activities towards Bacillus cereus and relatives. METHODS AND RESULTS: Twenty Bacillus thuringiensis strains were screened for their capacity to express bacteriocin-like agents. Strain BMG1.7, isolated from soil, showed an antagonistic activity called thuricin 7. Thuricin 7 was active against several species of the genus Bacillus, including three of the four known B. thuringiensis/B. cereus bacteriocin producers, as well as against Streptococcus pyogenes and Listeria monocytogenes strains. Antimicrobial activity was lost after treatment with proteinase K. The active protein had an apparent molecular weight of 11.6 kDa, and was secreted at the end of the exponential growth phase. Thuricin 7 retained 55% of the activity after incubation at 98 degrees C for 30 min. The mode of action of thuricin 7 was shown to be bactericidal and bacteriolytic. CONCLUSION: Thuricin 7 is a novel bacteriocin produced by a newly isolated Bacillus thuringiensis strain BMG1.7. SIGNIFICANCE AND IMPACT OF THE STUDY: The characteristics of thuricin 7 indicate that it is a new bacteriocin which may have interesting biotechnological applications due to its relatively large activity spectrum.


Asunto(s)
Bacillus thuringiensis/metabolismo , Bacteriocinas/biosíntesis , Bacteriocinas/aislamiento & purificación , Bacillus cereus/efectos de los fármacos , Bacillus thuringiensis/efectos de los fármacos , Bacillus thuringiensis/crecimiento & desarrollo , Bacillus thuringiensis/aislamiento & purificación , Bacteriocinas/farmacología , Medios de Cultivo , Bacterias Grampositivas/efectos de los fármacos , Microbiología del Suelo
14.
DNA Cell Biol ; 19(10): 589-99, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11058961

RESUMEN

Expression of the oncodevelopmental alpha-fetoprotein (AFP) gene is tightly regulated and occurs in the yolk sac, fetal liver and intestine, and cancerous liver cells. Transcription of the AFP gene is under the control of three enhancers that are very tissue specific. We have shown that the most upstream of these enhancers, located at -6 kb, works through the combined action of liver-enriched factors and nuclear receptors that bind to three regions of this DNA regulatory element. This study showed that orphan nuclear receptors of the ROR alpha, Re-verb alpha, and Rev-erb beta groups can bind as monomers with high affinity and specificity to an evolutionarily conserved AGGTCA motif in the functionally important region 1 of this AFP enhancer. Transient transfection experiments performed with human HepG2 hepatoma cells showed that overproduction of ROR alpha 4 stimulated the activity of the AFP enhancer in a dose-dependent manner, while that of Rev-erb alpha and Rev-erb beta had the opposite effect. These effects were highly specific and required the integrity of the AGGTCA motif. The action of these nuclear receptors also occurred in the context of the entire 7-kb regulatory region of the rat AFP gene. These results suggest that altering the amounts or activities of these orphan receptors in cells of hepatic or endodermal origin could modulate AFP gene expression in response to a variety of developmental or carcinogenic stimuli.


Asunto(s)
Elementos de Facilitación Genéticos/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores de Hormona Tiroidea , alfa-Fetoproteínas/metabolismo , Animales , Secuencia de Bases , Sitios de Unión , Unión Competitiva , Células CACO-2 , Pollos , Cloranfenicol O-Acetiltransferasa/genética , Cloranfenicol O-Acetiltransferasa/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Expresión Génica , Regulación de la Expresión Génica , Humanos , Ratones , Miembro 1 del Grupo D de la Subfamilia 1 de Receptores Nucleares , Miembro 1 del Grupo F de la Subfamilia 1 de Receptores Nucleares , Plásmidos , Unión Proteica , Proteínas/genética , Proteínas/metabolismo , ARN/genética , ARN/metabolismo , Ratas , Receptores Citoplasmáticos y Nucleares/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transactivadores/genética , Transactivadores/metabolismo , Transfección , Células Tumorales Cultivadas , alfa-Fetoproteínas/genética
15.
J Endocrinol ; 159(2): 341-8, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9795376

RESUMEN

An isocaloric low-protein (LP) diet (8% instead of 20% in controls) given to dams during gestation reduces the fractional insulin release of stimulated fetal islets. The LP diet lowers the plasma concentration of taurine in both pregnant rats and their fetuses. This study reports the effect of taurine on the in vitro release of insulin from control and LP fetal islets. Direct stimulation with taurine, methionine or leucine increased the release of insulin from control islets. Nevertheless, no effect on LP islets was observed with either taurine or methionine. The release of insulin from LP islets was reduced with leucine. The in vitro addition of taurine (0. 3 or 3 mM) to the culture medium increased the release of insulin from the control islets in response to arginine or leucine, but it did not restore the reduced responsiveness of LP islets to these amino acids. When 2.5% taurine was added to the drinking water of control or LP dams (groups C+T and LP+T) throughout gestation, the concentration of taurine increased in the serum of dams and fetuses of both groups. The release of insulin from the LP+T fetuses was restored to control levels when stimulated with taurine, methionine, leucine or arginine. In conclusion, taurine stimulated control fetal islets in vitro, but failed to do so in LP islets. However, the addition of taurine to the diet of LP dams restored to normal the release of insulin from LP fetal islets, indicating the importance of taurine during development for a normal fetal beta cell function.


Asunto(s)
Dieta con Restricción de Proteínas , Insulina/metabolismo , Islotes Pancreáticos/embriología , Islotes Pancreáticos/metabolismo , Taurina/farmacología , Análisis de Varianza , Animales , Arginina/farmacología , Técnicas de Cultivo , Femenino , Sangre Fetal/química , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Leucina/farmacología , Intercambio Materno-Fetal , Metionina/farmacología , Embarazo , Ratas , Estimulación Química , Taurina/sangre
16.
J Endocrinol ; 151(3): 501-6, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8994395

RESUMEN

Islets of rat fetuses born to mothers fed a low protein diet (LP) have a depressed insulin secretion in vitro in response to secretagogues. These fetuses have lower plasma levels of taurine than controls. The aim of this study was to analyze the effect of taurine on fetal islets insulin secretion. After 5 days of culture in serum containing standard RPMI medium, islets were cultured for 2 days in serum-free DME/F12 medium with 8.2 or 16.7 mM glucose alone or with taurine at 0.3 or 3 mM. They were then incubated for 120 min in Krebs Ringer solution with glucose alone (5.6 or 16.7 mM) or glucose (5.6 mM) added to leucine or arginine (both at 10 mM). In both concentrations of glucose, taurine increased the fractional insulin release by islets stimulated with secretagogues tested during the incubation. The effect did not seem to be mediated by changes in cAMP content. In a second set of experiments, islets cultured in RPMI medium for 7 days were incubated in the presence of Krebs Ringer solution with leucine (10 mM) or with sulfur amino acids (taurine at 10 mM, methionine or cysteine at 5 mM) for 120 min. Taurine and methionine stimulated insulin release at the same magnitude as leucine, whereas cysteine had no effect. In conclusion, taurine enhances insulin secretion by fetal islets, at least in vitro. Low taurine levels in fetuses from LP mothers might be implicated in their depressed insulin secretion.


Asunto(s)
Insulina/metabolismo , Islotes Pancreáticos/embriología , Islotes Pancreáticos/metabolismo , Taurina/farmacología , Animales , Técnicas de Cultivo , Cisteína/farmacología , Glucosa/farmacología , Secreción de Insulina , Islotes Pancreáticos/efectos de los fármacos , Leucina/farmacología , Metionina/farmacología , Ratas , Ratas Wistar , Estimulación Química
17.
Peptides ; 15(2): 341-51, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7911994

RESUMEN

The cholecystokinin (CCK)- and tyrosine hydroxylase (TH)-like immunoreactive (LI) axons and boutons were studied in the caudal and medial parts of the rat nucleus accumbens (NAC), using the indirect immunoperoxidase technique, at the electron microscopic level. Both CCK- and TH-LI boutons contained clear synaptic vesicles and large granular vesicles of similar size, but the CCK-LI boutons contained more large granular vesicles than TH-LI boutons. The CCK-LI and TH-LI boutons were heterogeneous. This finding might be related to the various immunoreactive neuronal types innervating the caudomedial NAC. However, the CCK-LI boutons (containing mostly small, round, clear synaptic vesicles) formed mainly asymmetrical synaptic contacts with dendritic spines whereas the TH-LI boutons (containing medium-sized as well as small, round, clear synaptic vesicles) formed mostly symmetrical synaptic contacts with dendritic shafts.


Asunto(s)
Colecistoquinina/aislamiento & purificación , Núcleo Accumbens/química , Tirosina 3-Monooxigenasa/aislamiento & purificación , Animales , Axones/química , Axones/enzimología , Axones/inmunología , Axones/ultraestructura , Colecistoquinina/inmunología , Femenino , Técnicas para Inmunoenzimas , Masculino , Núcleo Accumbens/enzimología , Núcleo Accumbens/inmunología , Ratas , Sinapsis/química , Sinapsis/enzimología , Sinapsis/inmunología , Sinapsis/ultraestructura , Tirosina 3-Monooxigenasa/inmunología
18.
Neurosci Lett ; 49(3): 331-5, 1984 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-6387545

RESUMEN

The cholecystokinin (CCK)-like immunoreactive nerve terminals were studied in the caudal and medial parts of the rat nucleus accumbens (NA), using the indirect immunoperoxidase technique, at the electron microscopic level. In the labelled axon terminals the immunoprecipitate is localized inside large dense-cored vesicles which are occasionally present, and surrounds small and medium-sized, round, clear synaptic vesicles. The immunoreactive nerve terminals participate in synapses of both asymmetrical and symmetrical types containing mostly small synaptic vesicles. The asymmetrical synapses are much more numerous and mainly axo-spinous. The symmetrical synapses are less frequent and are axo-dendritic or axo-somatic.


Asunto(s)
Colecistoquinina/metabolismo , Núcleo Accumbens/metabolismo , Núcleos Septales/metabolismo , Animales , Axones/metabolismo , Técnicas para Inmunoenzimas , Microscopía Electrónica , Terminaciones Nerviosas/metabolismo , Núcleo Accumbens/ultraestructura , Ratas , Ratas Endogámicas , Sinapsis/ultraestructura
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