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1.
BMC Res Notes ; 16(1): 269, 2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37833749

RESUMEN

OBJECTIVES: Publication is one of the crucial parameters in research, and the inability to publish has been noted in many medical students' projects due to different reasons. This cross-sectional study aimed to determine the obstacles that prevented medical students in a health science university from publishing their research from 2018 to 2021. First, an online survey was distributed to assess the obstacles to publication perceived by the medical students. Second, a total of 81 research projects were evaluated by scientific reviewers and their final decision about the publication was recorded. RESULTS: In total, 162 students filled out the survey. The barriers faced by the students were various. They included an unsupportive research supervisor, a lack of time, an insufficient sample size, and many others. In the reviewer's evaluation, out of 81 projects, 70 projects (86.4%) were recommended to be published after minor or major modifications, while 11 projects (13.6%) were rejected due to poor writing style, poor results interpretation, and incorrect methodology. CONCLUSION: Articulating the barriers to undergraduate medical research publication is important in boosting publication rates and research experience of graduating medical students. Medical research educators and research supervisors should strongly consider creating a framework that tackles existing obstacles and any future matters.


Asunto(s)
Investigación Biomédica , Estudiantes de Medicina , Humanos , Estudios Transversales , Encuestas y Cuestionarios , Investigadores
2.
Cell Rep ; 36(5): 109495, 2021 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-34348148

RESUMEN

Scn2a encodes the voltage-gated sodium channel NaV1.2, a main mediator of neuronal action potential firing. The current paradigm suggests that NaV1.2 gain-of-function variants enhance neuronal excitability, resulting in epilepsy, whereas NaV1.2 deficiency impairs neuronal excitability, contributing to autism. However, this paradigm does not explain why ∼20%-30% of individuals with NaV1.2 deficiency still develop seizures. Here, we report the counterintuitive finding that severe NaV1.2 deficiency results in increased neuronal excitability. Using a NaV1.2-deficient mouse model, we show enhanced intrinsic excitability of principal neurons in the prefrontal cortex and striatum, brain regions known to be involved in Scn2a-related seizures. This increased excitability is autonomous and reversible by genetic restoration of Scn2a expression in adult mice. RNA sequencing reveals downregulation of multiple potassium channels, including KV1.1. Correspondingly, KV channel openers alleviate the hyperexcitability of NaV1.2-deficient neurons. This unexpected neuronal hyperexcitability may serve as a cellular basis underlying NaV1.2 deficiency-related seizures.


Asunto(s)
Envejecimiento/fisiología , Canal de Sodio Activado por Voltaje NAV1.2/deficiencia , Neuronas/fisiología , Potenciales de Acción , Animales , Regulación hacia Abajo , Activación del Canal Iónico , Ratones Endogámicos C57BL , Canal de Sodio Activado por Voltaje NAV1.2/metabolismo , Canales de Potasio/metabolismo
3.
Cancer Treat Res Commun ; 25: 100220, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33333411

RESUMEN

BACKGROUND: Breast cancer (BC) is a major health issue threatening women's life. No reliable epidemiological data on BC diagnosed by oncologists/senologists are available in Algeria. METHODS: The BreCaReAl study, a non-interventional prospective cohort study, included adult women with confirmed BC in Algeria. Disease incidence, patients and disease characteristics, treatment patterns, and mortality rate were recorded up to 12 months of follow-up. RESULTS: Overall, 1,437 patients were analysed: median age was 48 [41;57] years and 337 (23.5%) women had a family history of BC. BC incidence was 22.3 (95% CI: 21.5; 23.2) cases per 100,000 inhabitants over 8 months. Delayed diagnosis was reported in 400 (29.2%) patients. First line of treatments were mainly chemotherapy and surgery. Twenty-eight serious adverse events were reported including 10 (37.0%) events which led to death. Mortality rate reached 3.2% at 12 months CONCLUSION: A delayed diagnosis highlights the importance of implementing more effective screening strategies.


Asunto(s)
Neoplasias de la Mama/epidemiología , Oncólogos/normas , Serología/normas , Argelia , Femenino , Humanos , Persona de Mediana Edad
4.
Adv Prev Med ; 2019: 2102156, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30805218

RESUMEN

Telemedicine is now in vogue, allowing through computer and communication tools to be deployed in the field of health, such as cardiology, area in which it has shown interest, in international studies. As the population ages, older people are increasingly concerned with this innovative practice. We take a look at telemedicine projects in France concerning the elderly, in the field of cardiology.

5.
Curr Gerontol Geriatr Res ; 2018: 9042180, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30310388

RESUMEN

Telemedicine is now in vogue, being deployed through computer and communication tools in various health fields, such as diabetology, nephrology, dermatology, neurology, and cardiology. With population ageing, geriatrics is coming into sharp focus. Telemedicine practices differ for home-based or institutionalized patients in long-term care homes. We take a look at telemedicine projects in France concerning the elderly.

7.
Cryo Letters ; 37(2): 110-4, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27224522

RESUMEN

BACKGROUND: Cardiac muscle cryopreservation is a challenge for both diagnostic procedure requiring viable tissues and therapeutic advance in regenerative medicine. Mitochondria are targets of both direct and indirect damages, secondary to congelation per se and/or to cryoprotectant's toxic effects, which participate to diminution of viability and/or functioning of cells after freezing. At the cardiac muscle level, only one study had investigated mitochondrial respiration after cryopreservation. OBJECTIVE: To determine the effect of cryopreservation on mitochondrial respiration of cardiac muscle. MATERIALS AND TMETHODS: We recorded mitochondrial respiration through complexes I, II, III and IV along with mitochondrial coupling in fresh and cryopreserved rat left ventricles samples and assessed difference of the means, correlation and agreement between the measures in all samples. RESULTS: Mitochondrial respiration was partly maintained up to 70% in cryopreserved samples whatever the substrate. A significant correlation was observed between fresh and cryopreserved samples (r = 0.71, p < 0.0001). However, mitochondrial coupling significantly decreased after cryopreservation (- 1.44 ± 0.15; p < 0.005) suggesting that mitochondrial intactness was not totally preserved by cryopreservation. Further, the fluctuations around the mean difference were wide (-14.06, +5.08 µmol/min/g), increasing with respiration rates (p < 0.0001). CONCLUSION: Thus, fresh samples extemporaneous analysis should be preferred when available despite the fact that cryopreservation using DMSO partly protect cardiac mitochondrial respiration and coupling. These data support the interest to further refine cryopreservation methods.


Asunto(s)
Criopreservación , Crioprotectores/farmacología , Dimetilsulfóxido/farmacología , Mitocondrias/metabolismo , Miocardio , Consumo de Oxígeno , Animales , Oxidación-Reducción , Ratas , Ratas Wistar
8.
Rev Med Interne ; 37(9): 587-93, 2016 Sep.
Artículo en Francés | MEDLINE | ID: mdl-26852082

RESUMEN

INTRODUCTION: Monitoring patients with heart failure by telemedicine systems is a potential means susceptible to optimize the management of these patients and avoid life-threatening emergencies. In this context, we experimented in internal medicine unit an e-platform E-care dedicated to automated, intelligent detection of situations at risk of heart failure. METHODS: The E-care platform based on medical sensors (blood pressure, heart rate, O2, weight), communicating (Bluetooth), to go up, in real time, to an intelligent physiological information and an analysis of the ontology medical, leading ultimately to the generation of alerts. After a development phase (proof of concept), the E-care platform has been deployed and tested by health professionals and patients in an internal medicine unit with 20 beds, opened on emergencies to the Strasbourg University Hospitals. RESULTS: One hundred and eighty patients were included and 1500 measurements were obtained. The patient profile included in this experiment was an elderly patient, with comorbidity in 90% of cases, with a loss of autonomy in 25%. Health professionals were using E-care platform every day to their great satisfaction. This experiment made it possible to validate the technology choices, to consolidate the system, and to test the robustness of the platform E-care. The collection continuously allowed us to have the critical number of patients for more detailed analysis of the relevance of alerts related to heart impairment. A preliminary analysis showed the relevance of the generated alerts. CONCLUSION: Preliminary results following the deployment of E-care platform in hospitals appear to show the relevance of technological choices, tools and solutions developed and adopted. This telemedicine system allows automatic, non-intrusive, generate alerts related to the detection of situations at risk for heart failure. Ultimately, E-care was capable of preventing hospitalization. A home deployment is currently underway.


Asunto(s)
Insuficiencia Cardíaca/diagnóstico , Monitoreo Fisiológico/métodos , Telemedicina/métodos , Anciano , Servicio de Cardiología en Hospital , Femenino , Humanos , Medicina Interna/métodos , Masculino , Medición de Riesgo
9.
Acta Gastroenterol Belg ; 76(2): 231-4, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23898561

RESUMEN

BACKGROUND AND AIMS: There are few studies examining the quality of life (QOL) of patients with haemorrhoidal disease. Transanal heamorrhoidal dearterialization (THD) is a treatment modality for heamorrhoidal disease in which a Doppler transducer is used to locate the supplying arteries that are subsequently ligated. The aim of this study was to assess symptoms and QOL changes following THD. PATIENTS AND METHODS: This was a prospective evaluation of QOL and symptom changes following THD. Patient symptoms, demographics and QOL were recorded preoperatively and 1-month post-operatively following THD using the medical outcomes study short-form-36 (SF-36). RESULTS: Thirteen patients undergoing THD were evaluated. One month following THD symptoms of haemorrhoid protrusion, bleeding, anal pain, painful defaecation, constipation and tenesmus, had all significantly reduced (P <0.05). Limitations in usual role activities because of physical health problems (53.8 +/- 10.5 Vs 90.4 +/-4.5, P = 0.004), vitality, energy and fatigue (45 +/- 6.9 Vs 73.5 +/- 5.0, P= 0.003), general mental health, psychologic distress and wellbeing (60.9 +/- 6.9 Vs 83.1 +/- 5.9, P= 0.023), limitations in social activities because of physical or emotional problems (58.7 +/- 8.8 Vs 84 +/- 5.9, P = 0.025), and physical pain (52.9 +/- 7.9 Vs 84.6 +/- 6.4, P= 0.005) scores had all improved 1-month following THD. CONCLUSIONS: THD significantly reduces symptoms of haemorrhoidal disease and improves specific aspects of QOL 1-month following surgery.


Asunto(s)
Procedimientos Quirúrgicos del Sistema Digestivo/psicología , Hemorroides/cirugía , Satisfacción del Paciente , Calidad de Vida , Ultrasonografía Doppler/métodos , Procedimientos Quirúrgicos Vasculares/métodos , Adulto , Estudios de Casos y Controles , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Femenino , Estudios de Seguimiento , Hemorroides/diagnóstico por imagen , Hemorroides/psicología , Humanos , Ligadura/métodos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Estudios Prospectivos , Recto/irrigación sanguínea , Recto/diagnóstico por imagen , Encuestas y Cuestionarios , Factores de Tiempo
10.
J Environ Radioact ; 101(12): 1024-31, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20832920

RESUMEN

This paper presents a novel approach of measuring radon in-water in the field by inserting a MEDUSA gamma-ray detector into a 210 L or 1000 L container. The experimental measurements include investigating the effect of ambient background gamma-rays on in-field radon measurement, calibrating the detector efficiency using several amounts of KCl salt dissolved in tap water, and measuring radon in borehole water. The results showed that there is fairly good agreement between the field and laboratory measurements of radon in water, based on measurements with Marinelli beakers on a HPGe detector. The MDA of the method is 0.5 Bq L⁻¹ radon in-water.


Asunto(s)
Monitoreo de Radiación/métodos , Radón/análisis , Contaminantes Radiactivos del Agua/análisis , Abastecimiento de Agua/análisis , Calibración , Espectrometría gamma , Abastecimiento de Agua/normas
11.
J Colloid Interface Sci ; 337(1): 88-96, 2009 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-19527906

RESUMEN

This paper describes colloidal particles that are designed to induce hyper-intensity contrast (T(1) relaxation) in MRI. The contrast agents consist of discrete gadolinium complexes tethered to 10 nm diameter silver nanoparticles. The gadolinium complexes (1) [Gd(DTPA-bisamido cysteine)](2-) and (2) [Gd(cystine-NTA)(2)](3-), undergo chemisorption to particle surfaces through thiol or disulfide groups, respectively, to form two new contrast agents. The resulting nanoparticulate constructs are characterized on the basis of their syntheses, composition, spectra and contrast enhancing power. The average r(1) relaxivities of the of the surface bound complexes (obtained at 9.4 T and 25 degrees C) are 10.7 and 9.7 s(-1) mM(-1), respectively, as compared to 4.7 s(-1) mM(-1) for the clinical agent Magnevist. Correspondingly, the respective whole particle relaxivities are 27927 and 13153 s(-1) mM(-1).


Asunto(s)
Medios de Contraste/química , Oro/química , Elementos de la Serie de los Lantanoides/química , Imagen por Resonancia Magnética/métodos , Nanopartículas del Metal , Espectroscopía de Resonancia Magnética , Microscopía Electrónica de Transmisión , Espectrofotometría Ultravioleta
12.
Appl Radiat Isot ; 66(11): 1623-6, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18515121

RESUMEN

Measurement of radon in water by gamma-ray spectrometry using a HPGe detector has been investigated to determine aquifer characteristics. The radon activity concentration is determined by taking the weighted average of the concentrations derived from gamma-ray lines associated with (214)Pb and (214)Bi decay. The role of accurate radon data to representatively sample aquifers was also investigated by studying a semi-cased borehole. A simplified physical model describing the change of radon concentration with the pumping time, reproduces the data and predicts the time for representative sampling of the aquifer.


Asunto(s)
Monitoreo de Radiación/métodos , Radioisótopos/análisis , Radón/análisis , Contaminantes Radiactivos del Suelo/análisis , Espectrometría gamma/métodos , Contaminantes Radiactivos del Agua/análisis , Dosis de Radiación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sudáfrica
13.
Clin Transplant ; 22(5): 542-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18394002

RESUMEN

BACKGROUND: Increased brain natriuretic peptide (BNP) in cardiovascular disease is thought to be a compensatory protective mechanism allowing to delay the occurrence of terminal heart failure. Heart transplantation should normalize the neuroendocrine balance but BNP remains elevated in stable heart-transplant recipients (Htx). Such increase has been related to persistent endothelial and cardiac dysfunctions. The purpose of this study was to determine whether selected Htx, presenting with normal hemodynamic and cardiac systolic and diastolic functions on both side of the heart, show a normalization of their BNP plasma values. METHODS: Of a cohort of well-being 26 Htx, we selected 12 patients with normal hemodynamics and left and right heart systolic and diastolic functions and compared their circulating BNP, cyclic guanosine monophosphate (cGMP) (the BNP second messenger) and endothelin-1 (ET) values with that of 12 age-, body mass index- and mean arterial pressure-matched controls. Cardiac function determination by echodoppler included cardiac filling pressures assessment using tissue Doppler imaging. Blood samples for biological and hormonal determinations were drawn at rest, within 15 min before echocardiography. RESULTS: As selected, hemodynamic and left and right heart systolic and diastolic functions were located in the normal range in Htx. Plasma ET value was also similar in Htx and controls (20.7 +/- 0.9 vs. 19.6 +/- 0.9 fmol/mL). However, circulating BNP, like cGMP, was still significantly increased after heart transplantation, when compared with controls (33.8 +/- 8.5 vs. 4.0 +/- 0.9 pg/mL, p = 0.002 and 8.2 +/- 1.1 vs. 4.4 +/- 0.3 nmol/L, p = 0.003) for BNP and cGMP, respectively, in Htx and controls. Interestingly, the sole correlation observed was between BNP and cGMP (r = 0.85, p < 0.0001) after heart transplantation. CONCLUSIONS: After heart transplantation, BNP remained increased despite the normalization of hemodynamic and cardiac systolic and diastolic functions. This suggests that such endocrine heart stimulation should not be viewed only as a hemodynamic marker in Htx. Further studies will be useful to investigate the role of pro-inflammatory cytokines and whether elevated BNP still possesses antifibrotic properties, further supporting the interest of enhancing its activity after heart transplantation.


Asunto(s)
Insuficiencia Cardíaca/sangre , Trasplante de Corazón/fisiología , Hemodinámica/fisiología , Péptido Natriurético Encefálico/sangre , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , GMP Cíclico/sangre , Ecocardiografía Doppler , Endotelina-1/sangre , Insuficiencia Cardíaca/fisiopatología , Humanos , Persona de Mediana Edad , Volumen Sistólico , Función Ventricular Izquierda/fisiología , Función Ventricular Derecha/fisiología
15.
Exp Cell Res ; 172(2): 432-8, 1987 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-3115801

RESUMEN

Stimulation of membrane ruffling is one of the first events induced by addition of growth factors to quiescent cultures. In order to assess the importance of intact cytoskeleton in induction, by EGF + insulin, of early events such as stimulation of rRNA, c-fos, and actin mRNA expression, we studied the effect of cytochalasin D (CD) on these metabolisms. We observed that CD slightly increased rRNA synthesis in nonstimulated cells; conversely, it decreased rRNA synthesis in cells stimulated by EGF + insulin. The maximal inhibition observed was 60%. The c-fos mRNA was not expressed in control cells and was accumulated in cells stimulated by the mixture of EGF + insulin; this accumulation was inhibited by CD. Actin mRNA was expressed in control cells and its expression was stimulated by EGF + insulin. Addition of CD decreased actin mRNA accumulation in stimulated cells but increased this accumulation in unstimulated cells. Our results, taken together, show that CD specifically affected the stimulation of rRNA and mRNA expression induced by growth factors and suggest that intact cytoskeleton and possibly membrane ruffling favored this stimulation.


Asunto(s)
Actinas/biosíntesis , Citocalasinas/farmacología , Citoesqueleto/fisiología , Factor de Crecimiento Epidérmico/farmacología , Insulina/farmacología , Proteínas Proto-Oncogénicas/biosíntesis , ARN Mensajero/biosíntesis , ARN Ribosómico/biosíntesis , Transcripción Genética/efectos de los fármacos , Actinas/genética , Animales , Células Cultivadas , Citocalasina D , Citoesqueleto/efectos de los fármacos , Sinergismo Farmacológico , Factor de Crecimiento Epidérmico/antagonistas & inhibidores , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Ratones , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-fos , ARN Ribosómico/genética
16.
Cell Biol Int Rep ; 10(4): 249-55, 1986 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3518953

RESUMEN

Addition of EGF and insulin to quiescent cultures of 3T3 cells induce a rapid stimulation of ATP turnover. We show that, like growth factors, anisomycin and cycloheximide, two inhibitors of protein synthesis, induce in 3T3 cells, a rapid increase in ATP turnover. However, this effect was not the result of the inhibition of protein synthesis since puromycin, in the same experimental conditions, did not stimulate ATP turnover.


Asunto(s)
Adenosina Trifosfato/metabolismo , Anisomicina/farmacología , Cicloheximida/farmacología , Pirrolidinas/farmacología , Animales , Células Cultivadas , Factor de Crecimiento Epidérmico/farmacología , Sustancias de Crecimiento/farmacología , Insulina/farmacología , Ratones , Fosfatos/metabolismo , Puromicina/farmacología , Factores de Tiempo
17.
Exp Cell Res ; 163(1): 261-5, 1986 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-3510887

RESUMEN

We have demonstrated previously a rapid increase in ATP turnover soon after adding epidermal growth factor (EGF) and insulin to quiescent cultures of Swiss 3T3 cells. In the present work, we tried to determine whether this increase could be correlated with the early stimulation by growth factors of cell movements. We showed that cytochalasin B (CB), in complete or glucose-free medium, inhibited this early increase caused by growth factors, in phosphate incorporation in small organic acid-soluble compounds (Po). Cytochalasin D (CD) specifically inhibited the stimulation caused by growth factors of Po labelling and ATP turnover, but lacked all inhibitory effect on unstimulated cells. The inhibitory effect of CD was transient. We hypothesize that addition of EGF and insulin to quiescent 3T3 cell cultures induces a rapid and transient change in cell movements, which could be responsible for about half of the early increase in ATP degradation and turnover.


Asunto(s)
Adenosina Trifosfato/metabolismo , Citocalasina B/farmacología , Citocalasinas/farmacología , Factor de Crecimiento Epidérmico/farmacología , Insulina/farmacología , Animales , Línea Celular , Movimiento Celular/efectos de los fármacos , Medios de Cultivo , Citocalasina D , Ratones , Fosfatos/metabolismo
18.
Biochem Biophys Res Commun ; 133(1): 265-73, 1985 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-3907636

RESUMEN

We previously shown a rapid increase in ATP turnover after addition of epidermal growth factor and insulin to quiescent 3T3 cell cultures. Here, the relationship between this increase in ATP turnover and the activation by growth factors of Na+/H+ and Na+/K+ exchange systems was studied. Our results show that alkalinization of the medium enhances ATP turnover but they do not support the assumption that stimulation by growth factors of the Na+/H+ exchange induces an increase in ATP turnover since this increase was not inhibited by amiloride. Conversely, when ATP synthesis was abolished, the increase, in intracellular pH, by growth factors, was significantly decreased.


Asunto(s)
Adenosina Trifosfato/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Insulina/farmacología , Potasio/metabolismo , Sodio/metabolismo , Amilorida/farmacología , Animales , Células Cultivadas , Concentración de Iones de Hidrógeno , Ratones , Ouabaína/farmacología , Rubidio/metabolismo
19.
Exp Cell Res ; 158(2): 311-20, 1985 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-3891384

RESUMEN

Addition of a mixture of EGF + insulin to quiescent cell cultures synergistically stimulates the cells to reinitiate DNA synthesis and cell division. We have previously demonstrated that this mixture rapidly increases ATP turnover in quiescent cells. The present work shows that each of the two growth factors, EGF and insulin, when added separately to quiescent cells was able to stimulate the phosphorylation of the organic acid-soluble compounds (Po) pool and ATP turnover. The stimulation of ATP turnover was closely correlated with the increase in phosphorylation of the Po pool which suggests that Po labelling reflects the ATP turnover. In many experiments, the synergy between the two growth factors on the early increase in phosphorylation of the Po pool was clearly shown. Doubling the concentration of EGF (12-24 ng/ml) or insulin (50-100 ng/ml) did not increase early stimulation of phosphorylation of the Po pool, whereas simultaneous addition of the two growth factors induced a greater stimulation than that of each growth factor separately added. The augmentation in Po labelling after addition of EGF or insulin alone was transient. The synergistic effect of the two growth factors was more significant when determined 150 or 300 min after growth-factor addition. In our experimental conditions, each of the two growth factors, EGF and insulin, was able to induce a stimulation of DNA synthesis. However, the best stimulatory effect was observed with the mixture of the two which synergistically increased DNA synthesis determined between 6 and 24 h after growth-factor addition. The comparison between DNA replication and Po labelling suggests a correlation between the increase in DNA replication and in the total ATP synthesized in the first 5 h after cell stimulation by growth factors added separately or in combination.


Asunto(s)
Adenosina Trifosfato/metabolismo , Replicación del ADN/efectos de los fármacos , Factor de Crecimiento Epidérmico/farmacología , Insulina/farmacología , Animales , Sinergismo Farmacológico , Inosina/metabolismo , Cinética , Ratones , Fosfatos/metabolismo
20.
Exp Cell Res ; 149(2): 471-81, 1983 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-6196218

RESUMEN

Various early biochemical events have been observed after the addition of growth factors to quiescent cultures of 3T3 cells; however, the cascade of events which take place in the cells after growth-factor addition is not yet entirely known. Our results show that the addition of a mixture of two growth factors, i.e., Epidermal Growth Factor (EGF) and insulin, to quiescent cultures of 3T3 cells rapidly stimulated phosphate uptake and ATP turnover. Our present and previous results suggest that the increase in phosphate uptake is the consequence of the stimulation of ATP synthesis. This stimulation was not simply a consequence of an increase in oxidative phosphorylation or in glucose transport and metabolism. The change in ATP turnover was an early event observed as soon as 5 min after growth-factor addition; furthermore, it was not dependent on protein synthesis. This change may therefore be the result of post-synthetic modification of enzymes by phosphorylation. We do not know what cellular process is responsible for the increase in ATP turnover. Since growth-factor addition rapidly enhanced ATP degradation in quiescent 3T3 cell cultures, we assumed that this increase is the result of an increase in ATP degradation. We know that it was not due to a stimulation of an oligomycin-sensitive ATPase. We verified that it was not the consequence of early biochemical events like an increase in Na+/K+ ATPase or a stimulation of RNA or protein synthesis. However, it is of interest to note that the stimulation of ATP turnover due to the growth-factor addition was inhibited by quercetin.


Asunto(s)
Adenosina Trifosfato/metabolismo , Factor de Crecimiento Epidérmico/farmacología , Insulina/farmacología , Animales , Línea Celular , ADN/biosíntesis , Relación Dosis-Respuesta a Droga , Glucosa/metabolismo , Cinética , Ratones , Fosforilación Oxidativa , Fosfatos/metabolismo , Biosíntesis de Proteínas , Quercetina/farmacología , ARN/biosíntesis , ATPasa Intercambiadora de Sodio-Potasio/metabolismo
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