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1.
BMC Cardiovasc Disord ; 24(1): 15, 2024 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-38172687

RESUMEN

BACKGROUND: Patients with repaired Tetralogy of Fallot (rTOF) often develop pulmonary regurgitation (PR) and right ventricle (RV) dysfunction, experiencing increased mortality and morbidity rates in adulthood. Pulmonary valve replacement (PVR) timing to address PR is controversial. Cardiac Magnetic Resonance (CMR) is the gold standard for morpho-functional evaluation of complex cardiopathies. This study aims to identify CMR parameters predictive of adverse outcomes to help defining the best therapeutic management of rTOF patients. METHODS: 130 rTOF patients who underwent CMR (2006-2019) were enrolled in this retrospective single-center study. CMR, clinical, ECG and exercise data were analyzed. Univariate and multivariate analyses identified clinical and CMR parameters predictive of adverse outcomes both individually (e.g., death, arrhythmias, heart failure (HF), pharmacological therapy, QRS ≥ 160ms) and as composite outcome. RESULTS: Univariate analysis confirmed RV volumes and RV ejection fraction corrected for PR as adverse outcome predictors and identified interesting correlations: pulmonary artery bifurcation geometry and abnormal interventricular septum (IVS) motion with arrhythmias (p < .001; p = .037), HF (p = .049; p = .005), composite outcome (p = .039; p = .009); right atrium (RA) dimensions with the composite outcome and the outcomes individually (p < .001). The best predictive models by multivariate analysis included sex (male), RV and RA dilation for QRS ≥ 160ms, time form repair to CMR, age at TOF repair and IVS fibrosis for pharmacological therapy. CONCLUSIONS: Besides RV volumes, new adverse prognostic factors could guide rTOF therapeutic management: pulmonary arteries morphology, abnormal IVS motion, RV dysfunction, RA dilation. Perspective multicentric evaluation is needed to specify their effective role.


Asunto(s)
Insuficiencia Cardíaca , Insuficiencia de la Válvula Pulmonar , Tetralogía de Fallot , Disfunción Ventricular Derecha , Humanos , Masculino , Tetralogía de Fallot/diagnóstico por imagen , Tetralogía de Fallot/cirugía , Estudios Retrospectivos , Imagen por Resonancia Magnética , Insuficiencia de la Válvula Pulmonar/diagnóstico por imagen , Insuficiencia de la Válvula Pulmonar/etiología , Insuficiencia de la Válvula Pulmonar/cirugía , Espectroscopía de Resonancia Magnética , Función Ventricular Derecha , Disfunción Ventricular Derecha/diagnóstico por imagen , Disfunción Ventricular Derecha/etiología
2.
Eur J Orthop Surg Traumatol ; 29(5): 975-982, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30737557

RESUMEN

BACKGROUND: Posterior stabilization in patients treated with laminectomy for spondylotic cervical myelopathy is still a debate. Despite both being reported in literature by several authors, some controversies still exist. The aim of this study is to compare clinical and radiological outcomes in patients treated with laminectomy or laminectomy with posterior stabilization. MATERIAL AND METHODS: We retrospectively evaluated 42 patients affected by cervical myelopathy (mean age 70.43 ± 5.03 years), 19 treated with laminectomy (group A) and 23 with laminectomy and posterior instrumentation (group B). Neurological status was assessed with Nurick scale, pain with VAS and radiological parameters with C2-C7 SVA, T1 slope and C2-C7 lordosis, clinical function with modified Japanese Orthopaedic Association score (JOA). Also, surgery time and blood loss were recorded. Student's t test was used for continuous variables, while Kruskal-Wallis test was used for categorical values. RESULTS: No differences were found in postoperative Nurick scale (p = 0.587), VAS (p = 0.62), mJOA (p = 0.197) and T1 slope (p = 0.559), while laminectomy with fusion showed better postoperative cervical lordosis (p = 0.007) and C2-C7 SVA (p < 0.00001), but higher blood loss (p < 0.00001) and surgical time (p < 0.00001). Both groups showed better Nurick scale (p = 0.00017 for group A and p = 0.00081 for group B), VAS (p = 0.02 for group A and p = 0.046 for group B) and mJOA (p < 0.00001 for both groups) than preoperative values. CONCLUSIONS: Both treatments are a valuable choice, offering some benefits and disadvantages against each other. Each procedure must be carefully evaluated on the basis of patients' general status, preoperative pain, signs of instability and potential benefits from cervical alignment correction.


Asunto(s)
Vértebras Cervicales , Laminectomía , Enfermedades de la Médula Espinal , Fusión Vertebral , Espondilosis/complicaciones , Anciano , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/fisiopatología , Vértebras Cervicales/cirugía , Femenino , Humanos , Italia , Laminectomía/efectos adversos , Laminectomía/métodos , Masculino , Examen Neurológico/métodos , Evaluación de Resultado en la Atención de Salud , Estudios Retrospectivos , Enfermedades de la Médula Espinal/diagnóstico , Enfermedades de la Médula Espinal/etiología , Enfermedades de la Médula Espinal/fisiopatología , Enfermedades de la Médula Espinal/cirugía , Fusión Vertebral/instrumentación , Fusión Vertebral/métodos
3.
Eur Spine J ; 26(Suppl 4): 546-551, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28324215

RESUMEN

INTRODUCTION: The osteoporosis prevalence in population is age related. The aim of this single-center observational study was evaluate the middle- to long-term performance of cement (PMMA) augmented fenestrated pedicle screws in elderly patients with thoraco-lumbar compressive fractures by osteoporosis. MATERIALS AND METHODS: From 2011 to 2015 we treated 52 patients (20 males and 32 females) suffering from somatic osteoporotic fractures (T10-L2). The average age was 73.4 years, with an age range between 65 and 82 years. The treatment consisted of stabilization with pedicle screw augmentation with PMMA cement. Patients were clinically evaluated with Visual Analyzing System scale (VAS scale) and with low back disability questionnaire Oswestry, in pre and post surgery and during the follow up at 12 and 24 months. RESULTS: A total of 410 fenestrated pedicle screws with PMMA augmentation were implanted. No cases of loosening or pulling out of screws were recorded. There have been n 3 cases of thrombophlebitis, treated with oral anticoagulant drugs and 1 case of post-operative death due to ventricular fibrillation. No neurological complications occurred during the study. The mean VAS score decreased from 8.5 to 4.8 and the result remained stable during follow up. Oswestry questionnaire showed a mean decrease of low back pain of 24% in post-op period. CONCLUSION: Fenestrated screws with PMMA augmentation offers a possibility to treat patients with reduced bone quality due to severe osteoporosis.


Asunto(s)
Vértebras Lumbares/cirugía , Fracturas Osteoporóticas/cirugía , Fracturas de la Columna Vertebral/cirugía , Vértebras Torácicas/cirugía , Anciano , Anciano de 80 o más Años , Femenino , Fracturas por Compresión , Humanos , Masculino , Tornillos Pediculares , Polimetil Metacrilato , Resultado del Tratamiento
5.
Sci Total Environ ; 861: 160639, 2023 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-36470388

RESUMEN

The detection and attribution of methane in aquifers overlying oil and gas reservoirs has recently gained increasing attention internationally. The Surat Basin, in the Great Artesian Basin (GAB), Australia, hosts a coal seam gas (CSG) reservoir, with feedlots, town water supply, mines and agriculture that extract groundwater from aquifers that underly and overly the gas reservoir. This study aimed to use a multi-isotopic approach to differentiate biogenic methane generated in situ in GAB aquifers and the Condamine Alluvium, from the biogenic CSG produced from the underlying Walloon Coal Measures reservoir, to understand if gas had migrated or not. Dissolved methane (0.001 to 160 mg/l) and total methane concentrations (up to 91,818 ppmv) were measured using closed sampling methods and were higher than from open direct fill sampling (<0.001 to 25.4 mg/l), especially in gassy bores that contain dissolved methane above 10 to 13 mg/l. The CSG production waters and a gassy overlying aquifer bore had the most depleted water isotopes, and also the most enriched δ13C-DIC indicating strong methanogenesis. The majority of aquifers have isotopic signatures (δ13C-DIC, CH4 and CO2) indicating in situ methane production by primary CO2 reduction or fermentation, distinct from secondary microbial CO2 reduction in the CSG reservoir. Fractionation factors support methane production mainly via CO2 reduction, with fermentation in a subset of aquifer samples. The gas wetness parameters (636 to 20,000) are consistent with mainly microbial gases, with low dissolved ethane (max 0.04 mg/l). The majority of aquifer and alluvium samples in this study are consistent with in situ methane production, not migration, however in several gassy bores the methane source could not be clearly identified. This study is broadly applicable to understanding methane sources in aquifers overlying CSG reservoirs.


Asunto(s)
Agua Subterránea , Contaminantes Químicos del Agua , Metano/análisis , Dióxido de Carbono , Monitoreo del Ambiente , Contaminantes Químicos del Agua/análisis , Gases , Yacimiento de Petróleo y Gas , Carbón Mineral
6.
Eur Rev Med Pharmacol Sci ; 26(7): 2524-2542, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35442468

RESUMEN

OBJECTIVE: The purpose of this review is to discuss cardiovascular mortality as clinical outcome in the setting of both acute and chronic coronary syndromes (ACS and CCS) with a focus on the clinical evidence supporting the mortality benefit of ticagrelor across multiple subpopulations. MATERIALS AND METHODS: Papers considered for this review were retrieved from a PubMed search, using different combinations of keywords (e.g., mortality AND coronary syndrome AND dual antiplatelet therapy AND ticagrelor), without limitations in terms of publication date and language. RESULTS: Prevention of ischemic events and death is of outmost relevance in patients with ACS and CCS, given the high rate of recurrence of such events and fatalities. Owing to the evolving nature of patients with CCS, characterized by a broad spectrum of clinical presentations and previous medical history, as well as the advances in the therapeutic and invasive management of ACS, greater attention to the rate of hard clinical outcomes, improvement in the long-term prognosis, and reduction in the residual risk of recurrent events are increasingly reported among cardiologists. Dual antiplatelet therapy (DAPT) is the cornerstone of antithrombotic therapy aimed at lowering the rate of ischemic events and death in patients treated both conservatively and invasively after ACS, as well as improving prognosis in patients with CCS. Significant differences are emerging among oral P2Y12 inhibitors with regards to mortality benefit. CONCLUSIONS: Ticagrelor is an effective and well-tolerated option to attain a meaningful and clinically relevant reduction in cardiovascular mortality in both acute and chronic settings across a broad range of high-risk patient subpopulations with an acceptable payoff in terms of bleeding risk.


Asunto(s)
Síndrome Coronario Agudo , Intervención Coronaria Percutánea , Síndrome Coronario Agudo/tratamiento farmacológico , Aspirina/uso terapéutico , Humanos , Intervención Coronaria Percutánea/efectos adversos , Inhibidores de Agregación Plaquetaria , Factores de Riesgo , Ticagrelor/uso terapéutico , Resultado del Tratamiento
7.
Osteoporos Int ; 22(11): 2869-77, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21116815

RESUMEN

UNLABELLED: This study evaluates cytokines production in bone and bone marrow of patients with an osteoporotic fracture or with osteoarthritis by real time PCR, Western blot and immunohistochemistry. We demonstrate that the cytokine pattern is shifted towards osteoclast activation and osteoblast inhibition in patients with osteoporotic fractures. INTRODUCTION: Fragility fractures are the resultant of low bone mass and poor bone architecture typical of osteoporosis. Cytokines involved in the control of bone cell maturation and function are produced by both bone itself and bone marrow cells, but the roles of these two sources in its control and the amounts they produce are not clear. This study compares their production in patients with an osteoporotic fracture and those with osteoarthritis. METHODS: We evaluated 52 femoral heads from women subjected to hip-joint replacement surgery for femoral neck fractures due to low-energy trauma (37), or for osteoarthritis (15). Total RNA was extracted from both bone and bone marrow, and quantitative PCR was used to identify the receptor activator of nuclear factor kB Ligand (RANKL), osteoprotegerin (OPG), macrophage colony stimulating factor (M-CSF), transforming growth factor ß (TGFß), Dickoppf-1 (DKK-1) and sclerostin (SOST) expression. Immunohistochemistry and Western blot were performed in order to quantify and localize in bone and bone marrow the cytokines. RESULTS: We found an increase of RANKL/OPG ratio, M-CSF, SOST and DKK-1 in fractured patients, whereas TGFß was increased in osteoarthritic bone. Bone marrow produced greater amounts of RANKL, M-CSF and TGFß compared to bone, whereas the production of DKK-1 and SOST was higher in bone. CONCLUSIONS: We show that bone marrow cells produced the greater amount of pro-osteoclastogenic cytokines, whereas bone cells produced higher amount of osteoblast inhibitors in patients with fragility fracture, thus the cytokine pattern is shifted towards osteoclast activation and osteoblast inhibition in these patients.


Asunto(s)
Médula Ósea/metabolismo , Citocinas/metabolismo , Cabeza Femoral/metabolismo , Osteoartritis/metabolismo , Fracturas Osteoporóticas/metabolismo , Proteínas Adaptadoras Transductoras de Señales , Anciano , Anciano de 80 o más Años , Western Blotting , Proteínas Morfogenéticas Óseas/metabolismo , Femenino , Marcadores Genéticos , Humanos , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Factor Estimulante de Colonias de Macrófagos/metabolismo , Persona de Mediana Edad , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Osteoprotegerina/metabolismo , Ligando RANK/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Factor de Crecimiento Transformador beta/metabolismo
8.
Pediatr Cardiol ; 32(4): 527-9, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21327894

RESUMEN

Aortic regurgitation is a common complication of ventricular septal defects. The most common mechanism is right or noncoronary cusp prolapse. Other mechanisms are right or noncoronary cusp fibrosis resulting in thickening and restricted motion of the leaflets or infective endocarditis leading to cusp perforation. We describe a case of subacute and severe aortic regurgitation due to noncoronary cusp prolapse resulting in the development of a large aneurysm and rupture of the noncoronary sinus of Valsalva into the right atrium.


Asunto(s)
Rotura de la Aorta/complicaciones , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Ecocardiografía Doppler en Color/métodos , Defectos del Tabique Interventricular/diagnóstico por imagen , Seno Aórtico , Adulto , Rotura de la Aorta/diagnóstico por imagen , Rotura de la Aorta/cirugía , Insuficiencia de la Válvula Aórtica/etiología , Insuficiencia de la Válvula Aórtica/cirugía , Procedimientos Quirúrgicos Cardíacos/métodos , Diagnóstico Diferencial , Estudios de Seguimiento , Defectos del Tabique Interventricular/complicaciones , Defectos del Tabique Interventricular/cirugía , Humanos , Masculino
9.
Pediatr Med Chir ; 31(6): 252-7, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20333884

RESUMEN

INTRODUCTION: The aim of this paper was to report the management of a very rare malformative association of Left Pulmonary Artery (LPA) sling and Tracheal Lobe which is not still reported in scientific literature. MATERIALS AND METHODS: The Authors describe the clinical case of a 6 years old girl that was admitted for chronic respiratory symptoms associated with recurrent upper respiratory infections. The CT-scan with virtual bronchoscopy showed an ectopic bronchus arising from the right side of the upper third of the trachea and ending in an accessory pulmonary lobe, covered by normal pleura, located in the upper mediastinum. The tracheo-broncoscopy showed a stenotic tracheal lumen with complete cartilaginous ring with an evident vascular pulsation in the middle of stenotic tract. An angio-CT confirmed the vascular anomalies with the LPA which passes between the lower trachea and the accessory tracheal bronchus and the coexistence of a persistent left superior vena cava. The surgical approach, after the thoracoscopic exploration, was a double procedure through a median sternotomy with cardiopulmonary bypass has permitted to excise completely the tracheal lobe and to reimplant the left pulmonary artery into the main pulmonary artery. RESULTS: No more upper respiratory symptoms or pulmonary infections have been observed during the clinical and instrumental follow up. CONCLUSIONS: Current controversy in the management of Pulmonary Artery sling include surgical approach (median sternotomy versus left thoracotomy), use or non-use of cardiopulmonary bypass, and reimplantation versus translocation with distal tracheal resection. In our experience LPA reimplantation and tracheal lobe resection have been made easily and safely by the same sternotomy utilized for the cardio-pulmonary by-pass.


Asunto(s)
Bronquios/anomalías , Anomalías Congénitas/cirugía , Arteria Pulmonar/anomalías , Esternotomía , Estenosis Traqueal/congénito , Angiografía , Niño , Anomalías Congénitas/diagnóstico , Anomalías Congénitas/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Radiografía Torácica , Factores de Tiempo , Tomografía Computarizada por Rayos X , Estenosis Traqueal/cirugía , Resultado del Tratamiento
10.
Psychiatry Res ; 272: 698-706, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30832189

RESUMEN

OBJECTIVES: To identify the variables that are associated with persistence to Aripiprazole-Long Acting (A-LAI), in adult patients with schizophrenia. METHODS: Observational, retrospective, non-interventional study involving 261 patients with schizophrenia. RESULTS: Eighty-six percent of study subjects were persistent for at least 6 months. All subjects with baseline CGI-S of 1 or 2, 95% of subjects with CGI-S of 3, 86% with CGI-S of 4, 82% of subjects with CGI-S of 5, 73% of subjects with CGI of 6 and 90% of subjects with CGI of 7 were persistent. A-LAI treatment continuation rate was higher in patients with: 1) baseline CGI score ≤ 4; 2) schizophrenia dimension (LDPS) mania score ≤ 5; 3) psychotic spectrum schizoid score ≤ 11. CONCLUSIONS: A relatively high number of patients (n = 225, 86%) were persistent to A-LAI for at least 6 months. Not surprisingly, very severe patients were more unlikely to be persistent. However, it is noteworthy that a large number of subjects with high CGI score at the time when A-LAI was started (82% of subjects with CGI-S of 5, 73% of subjects with CGI of 6 and 90% of subjects with CGI of 7) were persistent. Larger, controlled, prospective and longer studies are warranted.


Asunto(s)
Antipsicóticos/uso terapéutico , Aripiprazol/uso terapéutico , Esquizofrenia/tratamiento farmacológico , Adulto , Preparaciones de Acción Retardada/uso terapéutico , Femenino , Humanos , Italia , Masculino , Cumplimiento de la Medicación , Persona de Mediana Edad , Estudios Retrospectivos , Resultado del Tratamiento
11.
Eur J Anaesthesiol ; 25(8): 670-4, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18400142

RESUMEN

BACKGROUND AND OBJECTIVE: To evaluate the use of remifentanil-propofol administered as target-controlled infusion during awake fibreoptic intubation for anticipated difficult tracheal intubation in acromegalic patients. METHOD: In all, 20 consecutive acromegalic patients underwent elective endonasal endoscopic transsphenoidal pituitary surgery. After premedication with midazolam 0.03 mg kg(-1), initially a target-controlled infusion of remifentanil 1.0 ng mL(-1) and propofol 1.5 microg mL(-1) was started. The fibreoptic intubation was performed by the same physician experienced with the fibreoptic technique. During the fibreoptic procedure the target concentrations of remifentanil and propofol ranged between 1.0 and 5.0 ng mL(-1), and between 1.5 and 3.5 microg mL(-1), respectively. Changes in heart rate and mean arterial pressure were recorded during airway manipulation, during tracheal intubation, and at 1 and 3 min after. On the first postoperative day, patient recall and level of discomfort during fibreoptic intubation were evaluated. RESULTS: Endotracheal intubation was efficaciously and quickly secured in all patients. A significant increase in mean arterial pressure and heart rate was recorded only during tracheal intubation (P < 0.05). Oxygenation was sufficient and no bradypnea or apnoea was recorded. All patients later described their anaesthetic experience as satisfactory. During fibreoptic intubation, remifentanil (ng mL(-1)) and propofol (microg mL(-1)) mean effect-site concentrations were 3.2 +/- 0.3 and 2.0 +/- 1.0, respectively. CONCLUSION: Remifentanil and propofol target-controlled infusion provided satisfactory conscious sedation allowing for successful oral fibreoptic intubation in acromegalic patients with no recall.


Asunto(s)
Anestésicos Intravenosos/administración & dosificación , Sedación Consciente , Intubación Intratraqueal/instrumentación , Piperidinas/administración & dosificación , Propofol/administración & dosificación , Acromegalia/cirugía , Adulto , Anciano , Análisis de Varianza , Presión Sanguínea/efectos de los fármacos , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Infusiones Intravenosas/instrumentación , Infusiones Intravenosas/métodos , Intubación Intratraqueal/métodos , Masculino , Recuerdo Mental/efectos de los fármacos , Persona de Mediana Edad , Satisfacción del Paciente , Estudios Prospectivos , Remifentanilo
12.
Bone Marrow Transplant ; 53(1): 58-63, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29084200

RESUMEN

Several guidelines have been published about management of chronic GvHD (cGvHD), but the clinical practice still remains demanding. The Gruppo Italiano Trapianto di Midollo Osseo (GITMO) has planned a prospective observational study on cGvHD, supported by a dedicated software, including the updated recommendations. In view of this study, two surveys have been conducted, focusing the management of cGvHD and ancillary therapy in cGvHD, to address the current 'real life' situation. The two surveys were sent to all 57 GITMO centers, performing allografting in Italy; the response rate was 57% and 66% of the interviewed centers, respectively. The first survey showed a great disparity especially regarding steroid-refractory cGvHD, although extracorporeal photo-apheresis resulted as the most indicated treatment in this setting. Another challenging issue was the strategy for tapering steroid: our survey showed a great variance, and this disagreement could be a real bias in evaluating outcomes in prospective studies. As for the second survey, the results suggest that the ancillary treatments are not standardized in many centers. All responding centers reported a strong need to standardize management of cGvHD and to participate in prospective trials. Before starting observational and/or interventional studies, a detailed knowledge of current practice should be encouraged.


Asunto(s)
Enfermedad Injerto contra Huésped/terapia , Enfermedad Crónica , Femenino , Enfermedad Injerto contra Huésped/patología , Humanos , Italia , Masculino
13.
J Contam Hydrol ; 92(3-4): 255-73, 2007 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-17337313

RESUMEN

Unsaturated (80% water saturated) packed column experiments were conducted to investigate the influence of grain size distribution and bacteria surface macromolecules on bacteria (Rhodococcus rhodochrous) transport and deposition mechanisms. Three sizes of silica sands were used in these transport experiments, and their median grain sizes were 607, 567, and 330 microm. The amount of retained bacteria increased with decreasing sand size, and most of the deposited bacteria were found adjacent to the column inlet. The deposition profiles were not consistent with predictions based on classical filtration theory. The experimental data could be accurately characterized using a mathematical model that accounted for first-order attachment, detachment, and time and depth-dependent straining processes. Visual observations of the bacteria deposition as well as mathematical modelling indicated that straining was the dominant mechanism of deposition in these sands (78-99.6% of the deposited bacteria), which may have been enhanced due to the tendency of this bacterium to form aggregates. An additional unsaturated experiment was conducted to better deduce the role of bacteria surface macromolecules on attachment and straining processes. In this case, the bacteria surface was treated using a proteolitic enzyme. This technique was assessed by examining the Fourier-transform infrared spectrum and hydrophobicity of untreated and enzyme treated cells. Both of these analytical procedures demonstrated that this enzymatic treatment removed the surface proteins and/or associated macromolecules. Transport and modelling studies conducted with the enzyme treated bacteria, revealed a decrease in attachment, but that straining was not significantly affected by this treatment.


Asunto(s)
Bacterias/metabolismo , Tamaño de la Partícula , Dióxido de Silicio/química , Bacterias/química , Adhesión Bacteriana , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Proteínas de la Membrana/química , Proteínas de la Membrana/metabolismo , Porosidad , Propiedades de Superficie
15.
J Mol Biol ; 170(3): 699-722, 1983 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-6415291

RESUMEN

We have injected circular DNA, labeled with 32P at a single restriction site, into germinal vesicles of Xenopus laevis oocytes in order to study the nucleosome arrangement on the assembled minichromosomes. Two types of genes were used in these studies, the somatic 5 S RNA gene unit of Xenopus borealis and the histone gene unit of Drosophila melanogaster. We find that injections of labeled DNA alone, at 1 ng DNA per oocyte, results in irregularly spaced nucleosomes and partially supercoiled DNA molecules. However, perfectly spaced nucleosomes are assembled and fully supercoiled DNA is recovered if 5 to 20 nanograms of cold vector DNA is coinjected with the labeled DNA. At the optimum chromatin assembly conditions, the nucleosomes are perfectly spaced with a 180 base-pair periodicity, but they are randomly positioned on the DNA. The assembly of a periodic chromatin structure is accompanied by a dramatic enhancement in the expression of the injected 5 S RNA gene.


Asunto(s)
Cromatina/biosíntesis , Oocitos/metabolismo , Animales , Secuencia de Bases , Cromosomas/análisis , ADN/metabolismo , ADN Circular/metabolismo , ADN Superhelicoidal/metabolismo , Drosophila melanogaster , Femenino , Histonas/análisis , Nucleosomas/análisis , ARN Ribosómico/biosíntesis , Transcripción Genética , Xenopus laevis
16.
J Mol Biol ; 181(3): 333-49, 1985 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-4039007

RESUMEN

A cloned histone H4 gene of Xenopus laevis is efficiently transcribed after injection into germinal vesicles of X. laevis oocytes. Deletion analyses indicate that less than 140 base-pairs of 5' flanking sequences and 50 base-pairs of 3' flanking sequences are required for efficient transcription of this gene in Xenopus oocytes. Chromatin footprint analysis by a direct end-label technique reveals discrete DNase I-hypersensitive and micrococcal nuclease-hypersensitive sites at the 5' and 3' boundaries of the gene, which bracket the transcribed region of this minichromosome. The specific chromatin structure assembled around this homologous gene, together with the finding that histone genes of Drosophila melanogaster are not assembled into specific nucleoprotein structures within Xenopus oocytes, strongly suggest that sequence-specific and species-specific factors may be responsible for generating the chromatin-specific hypersensitive sites at the boundaries of active genes.


Asunto(s)
Cromatina , Genes , Histonas/genética , Animales , Autorradiografía , Secuencia de Bases , Mapeo Cromosómico , Cromosomas , Clonación Molecular , ADN , Desoxirribonucleasa I , Electroforesis en Gel de Poliacrilamida , Femenino , Nucleasa Microcócica , Oocitos , Transcripción Genética , Xenopus laevis
17.
Mech Dev ; 35(3): 193-203, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1768620

RESUMEN

In this paper we analyze the expression in follicular cells and regulation of the vitelline membrane protein gene we identified in region 32E of the second chromosome of D. melanogaster (VMP32E). We report germ line transformation results obtained with different kinds of gene fusion leading to the identification of a follicular cell subpopulation involved in the expression of the VMP32E. We have characterized two 5' non-transcribed regions (-465/-249; -135/-39) where the cis-acting transcriptional regulatory sequences, directing tissue and temporal specificity, are contained. The region between -465 and -249, which appears to control transcriptional high efficiency, does not behave as an enhancer as it is incapable of conferring any expression to a reporter gene. The region between -135 and -39 can confer temporal specificity of expression of the VMP32E gene, albeit at a very low level. Most interestingly, sequence similarities to ecdysone response elements raise the possibility of hormonal control also for VMP gene expression.


Asunto(s)
Proteínas del Huevo/genética , Regulación de la Expresión Génica , Oogénesis/genética , Folículo Ovárico/metabolismo , Secuencias Reguladoras de Ácidos Nucleicos , Membrana Vitelina/metabolismo , Animales , Secuencia de Bases , Northern Blotting , ADN , Sondas de ADN , Drosophila melanogaster/embriología , Drosophila melanogaster/genética , Femenino , Datos de Secuencia Molecular , Folículo Ovárico/embriología , Factores de Tiempo , Transcripción Genética , Transformación Genética , beta-Galactosidasa
18.
Exp Gerontol ; 40(1-2): 43-50, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15664731

RESUMEN

Ischemic preconditioning (IP) has been proposed as an endogenous form of protection against ischemia reperfusion injury. IP, however, does not prevent post-ischemic dysfunction in the aging heart but may be partially corrected by exercise training and food restriction. We investigated the role of exercise training combined with food restriction on restoring IP in the aging heart. Effects of IP against ischemia-reperfusion injury in isolated hearts from adult (A, 6 months old), sedentary 'ad libitum' fed (SL), trained ad libitum fed (TL), sedentary food-restricted (SR), trained- and food-restricted senescent rats (TR) (24 months old) were investigated. Norepinephrine release in coronary effluent was determined by high performance liquid cromatography. IP significantly improved final recovery of percent developed pressure in hearts from A (p<0.01) but not in those from SL (p=NS) vs unconditioned controls. Developed pressure recovery was partial in hearts from TL and SR (64.3 and 67.3%, respectively; p<0.05 vs controls) but it was total in those from TR (82.3%, p=NS vs A; p<0.05 vs hearts from TL and SR). Similarly, IP determined a similar increase of norepinephrine release in A (p<0.001) and in TR (p<0.001, p=NS vs adult). IP was abolished by depletion of myocardial norepinephrine stores by reserpine in all groups. Thus, IP reduces post-ischemic dysfunction in A but not in SL. Moreover, IP was preserved partially in TR and SR and totally in TR. Complete IP maybe due to full restoration of norepinephrine release in response to IP stimulus.


Asunto(s)
Envejecimiento/fisiología , Restricción Calórica , Precondicionamiento Isquémico Miocárdico , Daño por Reperfusión Miocárdica/prevención & control , Condicionamiento Físico Animal/fisiología , Animales , Peso Corporal/fisiología , Ventrículos Cardíacos/patología , Masculino , Daño por Reperfusión Miocárdica/metabolismo , Daño por Reperfusión Miocárdica/fisiopatología , Norepinefrina/metabolismo , Tamaño de los Órganos/fisiología , Ratas , Ratas Wistar
19.
Gene ; 23(2): 175-83, 1983 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-6311685

RESUMEN

Ligation of a 5'-labeled DNA restriction fragment results in a circular DNA molecule carrying the two 32Ps at the reformed restriction site. Double digestions of the circular DNA with the original enzyme and a second restriction enzyme cleavage near the labeled site allows direct chemical sequencing of one 5'-labeled DNA strand. Similar double digestions, using an isoschizomer that cleaves differently at the 32P-labeled site, allows direct sequencing of the now 3'-labeled complementary DNA strand. It is possible to directly sequence both strands of cloned DNA inserts by using the above protocol and a multiple cloning site vector that provides the necessary restriction sites. The simultaneous and parallel visualization of both DNA strands eliminates sequence ambiguities. In addition, the labeled circular molecules are particularly useful for single-hit DNA cleavage studies and DNA footprint analysis. As an example, we show here an analysis of the micrococcal nuclease-induced breaks on the two strands of the somatic 5S RNA gene of Xenopus borealis, which suggests that the enzyme may recognize and cleave small AT-containing palindromes along the DNA helix.


Asunto(s)
ADN/genética , Animales , Secuencia de Bases , Enzimas de Restricción del ADN , ADN Circular/genética , ADN Recombinante , Nucleasa Microcócica , Plásmidos , Xenopus/genética
20.
Insect Biochem Mol Biol ; 25(5): 603-12, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7787843

RESUMEN

We performed a molecular analysis of the Aphidius ervi ribosomal gene structure. This insect belongs to a set of closely related Aphidiinae species of the genus Aphidius Nees, of relevant interest in biological control. We constructed A. ervi genomic libraries, cloned and characterized several rDNA repeating units and sequenced different regions of the rDNA cistrons. We have found that insertion sequences interrupt the A. ervi 28S rDNA genes: the sequences of the two 5' and 3' insertion-28S junctions show that the elements are present at the position where R1 elements have been found in various insect species. In addition, the insertion of the element produces a duplication of the 14 nt target region. The sequence analysis indicates that the A. ervi elements belong to the R1 retrotransposon family with a highly conserved reverse transcriptase domain.


Asunto(s)
ADN Ribosómico , Genes de Insecto , Retroelementos , Ribosomas/genética , Avispas/genética , Secuencia de Aminoácidos , Animales , Bacteriófago lambda , Secuencia de Bases , Southern Blotting , Heterogeneidad Genética , Datos de Secuencia Molecular , ARN Ribosómico 28S/genética , Recombinación Genética , Secuencias Repetitivas de Ácidos Nucleicos
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