Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
1.
Phys Med Biol ; 60(22): 8851-67, 2015 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-26531765

RESUMEN

In this study we present a novel fully automated Hippocampal Unified Multi-Atlas-Networks (HUMAN) algorithm for the segmentation of the hippocampus in structural magnetic resonance imaging. In multi-atlas approaches atlas selection is of crucial importance for the accuracy of the segmentation. Here we present an optimized method based on the definition of a small peri-hippocampal region to target the atlas learning with linear and non-linear embedded manifolds. All atlases were co-registered to a data driven template resulting in a computationally efficient method that requires only one test registration. The optimal atlases identified were used to train dedicated artificial neural networks whose labels were then propagated and fused to obtain the final segmentation. To quantify data heterogeneity and protocol inherent effects, HUMAN was tested on two independent data sets provided by the Alzheimer's Disease Neuroimaging Initiative and the Open Access Series of Imaging Studies. HUMAN is accurate and achieves state-of-the-art performance (Dice[Formula: see text] and Dice[Formula: see text]). It is also a robust method that remains stable when applied to the whole hippocampus or to sub-regions (patches). HUMAN also compares favorably with a basic multi-atlas approach and a benchmark segmentation tool such as FreeSurfer.


Asunto(s)
Algoritmos , Enfermedad de Alzheimer/patología , Hipocampo/patología , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Neuroimagen/métodos , Humanos , Redes Neurales de la Computación , Reconocimiento de Normas Patrones Automatizadas
2.
Phys Med ; 31(8): 1085-1091, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26481815

RESUMEN

The hippocampus has a key role in a number of neurodegenerative diseases, such as Alzheimer's Disease. Here we present a novel method for the automated segmentation of the hippocampus from structural magnetic resonance images (MRI), based on a combination of multiple classifiers. The method is validated on a cohort of 50 T1 MRI scans, comprehending healthy control, mild cognitive impairment, and Alzheimer's Disease subjects. The preliminary release of the EADC-ADNI Harmonized Protocol training labels is used as gold standard. The fully automated pipeline consists of a registration using an affine transformation, the extraction of a local bounding box, and the classification of each voxel in two classes (background and hippocampus). The classification is performed slice-by-slice along each of the three orthogonal directions of the 3D-MRI using a Random Forest (RF) classifier, followed by a fusion of the three full segmentations. Dice coefficients obtained by multiple RF (0.87 ± 0.03) are larger than those obtained by a single monolithic RF applied to the entire bounding box, and are comparable to state-of-the-art. A test on an external cohort of 50 T1 MRI scans shows that the presented method is robust and reliable. Additionally, a comparison of local changes in the morphology of the hippocampi between the three subject groups is performed. Our work showed that a multiple classification approach can be implemented for the segmentation for the measurement of volume and shape changes of the hippocampus with diagnostic purposes.


Asunto(s)
Algoritmos , Hipocampo , Imagenología Tridimensional/métodos , Imagen por Resonancia Magnética
3.
Artículo en Inglés | MEDLINE | ID: mdl-24110298

RESUMEN

A wireless 64-channel ElectroCorticoGram (ECoG) recording implant named WIMAGINE(®) has been designed for clinical applications. This active implantable medical device is able to record ECoG on 64 electrodes with selectable gain and sampling frequency, with less than 0.7 µVRMS input referred noise in the [0.5 Hz - 300 Hz] band. It is powered remotely through an inductive link at 13.56 MHz, communicates wirelessly on the MICS band at 402-405 MHz with a custom designed base station connected to a PC and complies with the regulations applicable to class III AIMD. The design of the housing and the antenna have been optimized to ease the surgery and to take into account all the requirements of a clinical trial in particular patient safety and comfort. The main features of this WIMAGINE(®) implantable device and its architecture will be presented, as well as its performances and in vivo validations.


Asunto(s)
Electrodos Implantados , Electroencefalografía/instrumentación , Prótesis Neurales , Neuronas/fisiología , Tecnología Inalámbrica , Animales , Potenciales Evocados Visuales/fisiología , Humanos , Primates
4.
Ann Ig ; 25(5): 377-87, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24048176

RESUMEN

BACKGROUND: Oral and poster presentations at congresses are essential to spread scientific knowledge among the medical community. Many scientific societies have analyzed the quality of papers presented at their meetings but no information on abstracts' evaluation has been presented in Public Health field. DESIGN AND METHODS: This study aims to examine the quality of abstracts presented at annual meetings of Italian Public Health Society (SItI) in the period 2005-2010 through a validated checklist grid, evaluating eight dimensions: Inherency, Structure, Originality, Objectives, Study design, Sources, Results, Conclusions. Each item was scored from 0 to 3 points (max score: 24) and we used the average score in our study (15) as threshold of good quality. A multivariate analysis was performed in order to investigate predictors of score of abstracts presented. RESULTS: A total of 4,399 abstracts (1,172 oral communications, 3,227 posters) was examined. Around 60% were submitted by Universities and around 40% were from Central Italy. The highest quality was found in the fields of Vaccines (average score 18.9), Infectious Diseases (18) and in abstracts submitted by Universities (16.4). Predictors of lower quality identified were geographical area and affiliation (p= 0.002). Abstracts containing well-written Results, Conclusions and Objectives (3 points) were more likely to be of high quality(OR=55.6, OR=41.9, and OR=157.4; p>0.001) CONCLUSIONS: This is the first European study evaluating the quality of abstracts in the public health field. A reliable evaluation tool is fundamental to offer a transparent methodology of assessment and to improve the quality of research.


Asunto(s)
Indización y Redacción de Resúmenes/normas , Congresos como Asunto , Salud Pública , Lista de Verificación , Recolección de Datos , Bases de Datos Bibliográficas , Estudios de Evaluación como Asunto , Italia , Variaciones Dependientes del Observador , Proyectos Piloto , Control de Calidad , Mejoramiento de la Calidad
5.
Artículo en Inglés | MEDLINE | ID: mdl-23366009

RESUMEN

A wireless, low power, 64-channel data acquisition system named WIMAGINE has been designed for ElectroCorticoGram (ECoG) recording. This system is based on a custom integrated circuit (ASIC) for amplification and digitization on 64 channels. It allows the RF transmission (in the MICS band) of 32 ECoG recording channels (among 64 channels available) sampled at 1 kHz per channel with a 12-bit resolution. The device is powered wirelessly through an inductive link at 13.56 MHz able to provide 100mW (30mA at 3.3V). This integration is a first step towards an implantable device for brain activity monitoring and Brain-Computer Interface (BCI) applications. The main features of the WIMAGINE platform and its architecture will be presented, as well as its performances and in vivo studies.


Asunto(s)
Electrodos Implantados , Electroencefalografía/instrumentación , Tecnología Inalámbrica/instrumentación , Algoritmos , Animales , Interfaces Cerebro-Computador , Diseño de Equipo , Humanos , Monitoreo Fisiológico/instrumentación , Prótesis Neurales/estadística & datos numéricos , Primates , Cuadriplejía/rehabilitación , Ondas de Radio , Tecnología de Sensores Remotos/instrumentación , Telemetría/instrumentación
6.
Surg Endosc ; 15(9): 1038-41, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11443421

RESUMEN

BACKGROUND: Cholecystoenteric fistula (CF) is a rare complication of cholelithiasis. The aim of this study was to evaluate the safety and risk of complications when the laparoscopic approach is applied in patients with CF. METHODS: A questionnaire was mailed to all surgeons with experience of >100 cholecystectomies working in Naples, Italy, and the neighboring area. RESULTS: Between February 1990 and May 1999, 34 patients presented with cholecystoenteric fistula (0.2% of >15,000 laparoscopic cholecystectomies performed in the same period). These patients were allocated into two groups: the LT group (those who underwent laparotomic conversion after the diagnosis of CF), which consisted of 20 patients, four men and 16 women, with a mean age of 66.5 +/- 9.3 years (range, 46-85) and the LS group (laparoscopically treated patients), which consisted of 14 patients, three men and 11 women, with a mean age of 65.6 +/- 8.8 years (range, 51-74). They types of CF observed were as follows: in the former group of patients, cholecystoduodenal fistulas (n = 11, 55%), cholecystocolic fistulas (n = 5, 25%), cholecystojejunal fistulas (n = 3, 15%), and cholecystogastric fistulas (n = 1, 5%); in the latter group, cholecystoduodenal fistulas (n = 8, 5.1%), and cholecystocolic fistulas (n = 4, 28.6) and cholecystojejunal fistulas (n = 2, 14.3%). Stapler closure of CF was done in four LT patients and three LS patients with cholecystoduodenal fistula; it was also done in three LT patients and three LS patients with cholecystocolic fistula. Hand-sutured fistulectomy was performed in six LT patients and three LS patients with cholecystoduodenal fistula, in two LT patients with cholecystocolic fistula, and in all patients with cholecystojejunal or cholecystogastric fistula. There were no deaths or intraoperative complications in either group. One patient in the LT group developed a bronchopneumonia postoperatively. Postoperative hospital stay was significantly longer in LT patients-17 +/- 4 vs 3+/-1 days (p < 0.001). CONCLUSION: Cholecystoenteric fistula is an occasional intraoperative finding during laparoscopic cholecystectomy. The results of this study, which are based on the collective experiences of 19 surgeons, illustrate the growing success of the laparoscopic approach to this condition, including a decreasing rate of conversion to open surgery over the last 3 years.


Asunto(s)
Colecistectomía Laparoscópica/métodos , Colelitiasis/cirugía , Fístula/epidemiología , Fístula/cirugía , Enfermedades de la Vesícula Biliar/epidemiología , Enfermedades de la Vesícula Biliar/cirugía , Fístula Intestinal/epidemiología , Fístula Intestinal/cirugía , Anciano , Colangiopancreatografia Retrógrada Endoscópica , Colecistectomía Laparoscópica/estadística & datos numéricos , Colelitiasis/diagnóstico , Colelitiasis/epidemiología , Comorbilidad , Contraindicaciones , Enfermedades Duodenales/epidemiología , Enfermedades Duodenales/cirugía , Estudios de Factibilidad , Femenino , Fístula/diagnóstico , Enfermedades de la Vesícula Biliar/diagnóstico , Fístula Gástrica/epidemiología , Fístula Gástrica/cirugía , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
7.
Clin Nephrol ; 52(6): 339-43, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10604640

RESUMEN

AIM: Renovascular hypertension (RVH) is associated with a high prevalence of target organ damage and a high mortality. We have undertaken this follow-up study to assess the role played by comorbid conditions, and pharmacological treatment on survival, and on renal function in 64 patients with diffuse atherosclerotic vascular and renovascular disease (RVD). PATIENTS AND METHODS: The patients were followed for an average period of 37.3+/-20.4 months. RESULTS: At the end of the follow-up we found a cumulative survival at 5 years of 60%+/-10. Cerebrovascular and cardiovascular disease were responsible for 92% of deaths. A decrease in creatinine clearance >10 ml/min at 5 years was found in 65% of patients, 3 of whom ended in dialysis. Multivariate analysis of predictors of survival showed that treatment with angiotensin converting enzyme inhibitors (ACEi) was significantly associated with a favourable outcome (p = 0.019). Conversely, proteinuria had a negative effect. Renal survival was best predicted by the level of renal function at entry (p = 0.02), and was not influenced by pharmacological treatment. CONCLUSION: We conclude that ACEi exerts a beneficial effect on survival without affecting renal function in patients with RVD due to unilateral renal stenosis.


Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Hipertensión Renovascular/mortalidad , Enfermedades Renales/mortalidad , Anciano , Anciano de 80 o más Años , Arteriosclerosis/etiología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Hipertensión Renovascular/complicaciones , Hipertensión Renovascular/tratamiento farmacológico , Enfermedades Renales/complicaciones , Enfermedades Renales/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Análisis de Supervivencia , Resultado del Tratamiento
9.
J Cardiovasc Surg (Torino) ; 40(6): 803-9, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10776709

RESUMEN

BACKGROUND: The aim of the present study was to evaluate the systemic inflammatory response to CPB in paediatric patients undergoing surgical correction of congenital heart diseases. EXPERIMENTAL DESIGN: comparative investigation. SETTING: paediatric cardiology hospital INTERVENTION: ICAM-1, IL-8, and IL-6 production were analysed before and during CPB, and after surgery in 9 paediatric patients, submitted to cardiocirculatory arrest (Group A); and in 11 without cardiocirculatory arrest (Group B). MEASURES: ICAM-1, IL-8, and IL-6 production were analysed from arterial samples before and during CPB, and after surgery. RESULTS: In group A vs group B a significant increase of IL-8 was detected during (297+/-250 vs 11+/-19 pg x ml(-1), p<0.001) and after (100+/-230 vs n.d. pg x ml(-1)) surgery and was correlated with the duration of operation (r=0.759; p=0.0001) and clamping time (r=0.738; p<0.05). After surgery in group A, IL-6 levels (35+/-43 pg x ml) were higher than those in group B (2+/-5 pg x ml), and a good correlation was observed between IL-6 and duration of aortic clamping (r=0.714; p=0.048), cardiac arrest, (r=0.714; p=0.048), and length of surgery (r=0.867; p=0.04). CONCLUSIONS: In children who underwent CPB with cardiocirculatory arrest cytokine production seems related to duration of operation and amplified by ischemia-reperfusion phenomena.


Asunto(s)
Puente Cardiopulmonar , Paro Cardíaco Inducido , Cardiopatías Congénitas/cirugía , Molécula 1 de Adhesión Intercelular/sangre , Interleucina-6/sangre , Interleucina-8/sangre , Síndrome de Respuesta Inflamatoria Sistémica/diagnóstico , Niño , Preescolar , Femenino , Cardiopatías Congénitas/inmunología , Humanos , Lactante , Masculino , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/inmunología , Factores de Riesgo , Síndrome de Respuesta Inflamatoria Sistémica/inmunología
10.
J Vasc Res ; 34(4): 312-20, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9256092

RESUMEN

We examined the effects of hypoxic/ischemic stress on cerebral arteriolar responses to oxytocin in anesthetized piglets. Pial arteriolar diameters were measured using a cranial window and intravital microscopy. First, we evaluated arteriolar responses to topical application of oxytocin during normoxic conditions. We then determined whether 5-10 min of arterial hypoxia, ischemia, or asphyxia alters oxytocin-induced responses. Arterial hypoxia was produced by inhalation of 7.5% O2-92.5% N2 for 10 min. Ischemia was achieved by increasing intracranial pressure for 10 min. Asphyxia was achieved by turning off the ventilator for 5 min. During normoxic conditions, oxytocin dilated pial arterioles by 9 +/- 1% at 10(-8) and by 16 +/- 1% at 10(-6) mol/l (n = 47, p < 0.05). Arteriolar responses to oxytocin did not change with repeated applications (n = 10). Following hypoxia, dilator effect of oxytocin was not changed at 10(-8) (8 +/- 2%) but it was reduced at 10(-6) mol/l (7 +/- 2%; p < 0.05, n = 8). After asphyxia or ischemia, oxytocin did not dilate arterioles at 10(-8) mol/l, whereas 10(-6) mol/l resulted in a mild vasoconstriction (-4 +/- 3 to -6 +/- 4%, n = 6 and 8). Topically applied superoxide dismutase did not preserve arteriolar responses to oxytocin after asphyxia although the arterioles did not constrict to 10(-6) mol/l oxytocin (n = 5). Dilatation of cerebral arterioles in response to oxytocin was reversed to constriction by N(omega)-nitro-L-arginine methyl ester (L-NAME) (15 mg/kg, i.v.; n = 5) and by endothelial impairment by intra-arterial infusion of phorbol ester (10[-5] mol/l; n = 5). We conclude that the absence of pial arteriolar dilation to oxytocin after ischemia and asphyxia indicates endothelial dysfunction which may be involved in the pathology of perinatal brain injury.


Asunto(s)
Isquemia Encefálica/fisiopatología , Encéfalo/irrigación sanguínea , Circulación Cerebrovascular/efectos de los fármacos , Hipoxia/fisiopatología , Oxitocina/farmacología , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico , Animales , Animales Recién Nacidos , Femenino , Masculino , Óxido Nítrico/fisiología , Canales de Potasio/fisiología , Endoperóxidos de Prostaglandinas Sintéticos/farmacología , Superóxidos/metabolismo , Porcinos , Tromboxano A2/análogos & derivados , Tromboxano A2/farmacología , Vasoconstricción , Vasoconstrictores/farmacología , Vasodilatación
11.
J Cereb Blood Flow Metab ; 16(6): 1158-64, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8898688

RESUMEN

The interaction between ATP-sensitive K+ channels (KATP) and nitric oxide (NO) was studied in pial arterioles of piglets. We examined the effects of N omega-nitro-L-arginine methyl ester (L-NAME), a general inhibitor of nitric oxide synthase (NOS), and 7-nitroindazole (7-NI), a selective inhibitor of neuronal NOS, on aprikalim-induced cerebral vasodilation. Topically applied, aprikalim, a selective activator of KATP, dilated arterioles by 11 +/- 7% at 10(-8) M and 17 +/- 6% at 10(-6) M. After L-NAME treatment (15 mg/kg, i.v.), the response was reduced (4 +/- 4% and 12 +/- 7%, respectively; n = 8, p < 0.05). Administration of 7-NI (50 mg/kg, i.p.) did not change pial arteriolar responsiveness to aprikalim. However, both L-NAME and 7-NI reduced the vasodilator responses to 10(-4) M N-methyl-D-aspartate (NMDA) (by 73% and by 36%, respectively). Furthermore, 7-NI treatment abolished the glutamate-induced dilatation of pial arterioles. Administration of L-NAME reduced the NOS activity in the cerebral cortex by 88%, whereas the reduction after the 7-NI treatment was 44%. Pre-treatment and coadministration of 10(-5) M glibenclaminde, a specific inhibitor of KATP or L-NAME administration, did not change the dilatory response to sodium nitroprusside. We conclude that NO may be involved in aprikalim-induced dilation of pial arterioles.


Asunto(s)
Encéfalo/irrigación sanguínea , Óxido Nítrico/metabolismo , Canales de Potasio/metabolismo , Animales , Animales Recién Nacidos , Inhibidores Enzimáticos/farmacología , Indazoles/farmacología , Microcirculación/fisiología , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico Sintasa/antagonistas & inhibidores , Porcinos , Vasodilatación/efectos de los fármacos
12.
Stroke ; 27(9): 1634-9; discussion 1639-40, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8784141

RESUMEN

BACKGROUND AND PURPOSE: Recent studies in piglets show that either asphyxia or global cerebral ischemia, which combines effects of hypoxia and hypercapnia, transiently attenuates N-methyl-D-aspartate (NMDA)-induced pial arteriolar dilation. The purpose of this study was to determine individually the effects of hypoxic hypoxia and normoxic hypercapnia on NMDA-dependent cerebrovascular reactivity. In addition, we examined mechanisms involved in reduced cerebral vascular dilation to NMDA. METHODS: In anesthetized piglets, we examined pial arteriolar diameters using a cranial window and intravital microscopy. Arteriolar responses to topically applied NMDA were determined under control conditions and after arterial hypoxia or arterial hypercapnia. In addition, arteriolar responses to NMDA were examined in animals given indomethacin (10 mg/kg IV) or superoxide dismutase (100 U/mL, topical application) before hypoxia. RESULTS: Under control conditions, application of NMDA produced a dose-related dilation of pial arterioles (eg, 9 +/- 1% to 10(-5), 15 +/- 2% to 5 x 10(-5), and 28 +/- 5% to 10(-4) mol/L NMDA above baseline, respectively, in the hypoxic group; n = 6, P < .05). After transient exposure to 15 minutes of hypoxic hypoxia, arteriolar responses to NMDA were reduced at 30 minutes and at 60 minutes (10(-4) mol/L NMDA dilated by 12 +/- 5% and 18 +/- 5%, respectively; n = 6, P < .05). Five minutes of hypoxic hypoxia also reduced dilatation to NMDA. Indomethacin or superoxide dismutase preserved arteriolar responses to NMDA after 15 minutes of hypoxia. Pial arteriolar responses to NMDA remained unimpaired during and after hypercapnia. CONCLUSIONS: Short-term severe hypoxic hypoxia and reventilation impair the NMDA-induced dilatation of pial arterioles. Respiratory acidosis alone does not modify pial arteriolar reactivity to NMDA. The reduced responsiveness of the cerebral blood vessels to NMDA caused by hypoxia appears to be due to action of oxygen radicals.


Asunto(s)
Circulación Cerebrovascular/efectos de los fármacos , Hipercapnia/fisiopatología , Hipoxia/fisiopatología , N-Metilaspartato/farmacología , Vasodilatación , Enfermedad Aguda , Animales , Animales Recién Nacidos , Arteriolas/efectos de los fármacos , Arteriolas/fisiopatología , Femenino , Masculino , Piamadre/irrigación sanguínea
13.
Intensive Care Med ; 22(8): 735-41, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8880240

RESUMEN

OBJECTIVE: The aim of this study was to identify risk factors and to describe epidemiological patterns for early-(EOB) and late-onset bacteremias (LOB) after trauma. DESIGN: A prospective study conducted on 141 consecutive trauma patients. SETTING: A general intensive care unit (ICU) of a university hospital. PATIENTS: All multiple trauma patients admitted to our general intensive care unit (ICU) from December 1990 to May 1992 were prospectively enrolled in the study. The following information was collected for each patient and recorded in a computer database: demography, severity of trauma according to the Abbreviated Injury Scale (AIS), severity of coma according to the Glasgow Coma Scale (GCS), presence of pneumothorax, pulmonary contusion, rib fractures, hemothorax, and abdominal trauma, use of mechanical ventilation, and placement of central venous catheters. Bacteremias were defined as EOB when onset occurred within 96 h after trauma, and as LOB when appearing after 96 h from trauma. RESULTS: Thirty-seven patients developed bacteremia during their ICU stay (26%): 11 (29.7%) EOB and 26 (70.3%) LOB. Gram-positive cocci were isolated more frequently in EOB than in LOB (chi 2 = 4.1, P = 0.04). The risk of EOB was significantly increased by the presence of pulmonary contusion [relative risk (RR) 15.0; confidence interval (CI) 1.99-113.25], pneumonia before the onset of bacteremia (RR 3.56; CI 1.17-10.69), AIS score greater than 32 and an abdominal injury score greater than 9 (RR 3.11; CI 1.02-9.49), while intravascular catheters and mechanical ventilation did not represent risk factors for EOB. LOB had a very different pattern and their risk was significantly increased by exposure to intravascular catheters (RR 4.96; CI 1.23-19.94) and to mechanical ventilation lasting more than 7 days (RR 3.6; CI 1.6-8.1). CONCLUSIONS: Scoring with the AIS of the abdominal and thoracic trauma at admission to the ICU appears a useful tool for identifying trauma patients at increased risk of EOB. A rigorous policy of catheter placement and maintenance as a means of reducing late bacteremias in trauma patients is essential.


Asunto(s)
Bacteriemia/etiología , Traumatismo Múltiple/complicaciones , Traumatismos Abdominales/clasificación , Traumatismos Abdominales/complicaciones , Adulto , Cateterismo/efectos adversos , Distribución de Chi-Cuadrado , Femenino , Escala de Coma de Glasgow , Humanos , Unidades de Cuidados Intensivos , Masculino , Traumatismo Múltiple/clasificación , Neumonía/complicaciones , Estudios Prospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Traumatismos Torácicos/clasificación , Traumatismos Torácicos/complicaciones , Factores de Tiempo
14.
Am J Physiol ; 270(4 Pt 2): H1225-30, 1996 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8967360

RESUMEN

We examined the effects of total global ischemia on cerebral arteriolar responses to N-methyl-D-aspartate (NMDA) in anesthetized newborn pigs. Arteriolar responses to 10(-4) M NMDA were determined before and after 10 to 20 min of ischemia caused by increasing intracranial pressure. Before ischemia, NMDA dilated arterioles by 30 +/- 5% (baseline = 88 +/- 2 microns; n = 6). However, after 10 min of ischemia, arteriolar dilation was reduced to 10 +/- 3% at 1 h (P < 0.05). At 2 and 4 h, NMDA-induced dilation was not different from preischemia values. Twenty minutes of ischemia had similar effects. Coadministration of 100 U/ml of superoxide dismutase did not restore arteriolar dilation to NMDA at 1 h after ischemia. Sodium nitroprusside dilated by 14 +/- 3 and 40 +/- 5% at 10(-6) and 10(-5) M before ischemia, respectively, and arteriolar responsiveness was not changed by ischemia (n = 6). Cortical nitric oxide synthase (NOS) activity, measured by the in vitro conversion of L-[14C]arginine to L-[14C]citrulline, was unaffected by ischemia (n = 12). We conclude that decreases in cerebral arteriolar responsiveness to NMDA are not due to impairment of NOS activity, enhanced degradation or chelation of nitric oxide (NO), or reduced vascular smooth muscle responsiveness to NO.


Asunto(s)
Isquemia Encefálica/fisiopatología , Circulación Cerebrovascular/efectos de los fármacos , N-Metilaspartato/farmacología , Animales , Arteriolas/efectos de los fármacos , Arteriolas/fisiopatología , Encéfalo/enzimología , Femenino , Masculino , Óxido Nítrico Sintasa/metabolismo , Nitroprusiato/farmacología , Superóxido Dismutasa/farmacología , Porcinos , Vasodilatación
15.
Stroke ; 27(1): 134-8; discussion 139, 1996 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8553390

RESUMEN

BACKGROUND AND PURPOSE: Effects of anoxic stress on cerebrovascular responses to calcitonin gene-related peptide (CGRP) have not been examined previously. We determined the effects of total global ischemia on cerebral arteriolar responses to CGRP in newborn pigs. METHODS: Piglets were anesthetized and ventilated with a respirator. Pial arteriolar diameter was determined using a closed cranial window and intravital microscopy. Baseline arteriolar diameters ranged from 80 to 100 microns. Arteriolar responses to 10(-9) and 10(-8) mmol/L CGRP applied topically were determined before and 1, 2, and 4 hours after a 10-minute period of total global ischemia. Ischemia was caused by increasing intracranial pressure. RESULTS: Before ischemia, CGRP dilated arterioles by 14 +/- 2% (n = 6) and 24 +/- 3% (n = 7) at 10(-9) and 10(-8) mmol/L, respectively. However, after ischemia, arteriolar responses to 10(-9) mmol/L CGRP were reduced at 1 hour to 4 +/- 1%, at 2 hours to 3 +/- 2%, and at 4 hours to 5 +/- 4% (P < .05 for all comparisons). Similarly, arteriolar responses to 10(-8) mmol/L CGRP were reduced to 5 +/- 2% at 1 hour, 5 +/- 2% at 2 hours, and 10 +/- 6% at 4 hours (P < .05 for all comparisons). In time control animals, arteriolar responses to CGRP did not change over time. In other animals, we examined effects of pretreatment with indomethacin (5 mg/kg IV) on ischemia-induced decreases in arteriolar responses to CGRP. Indomethacin administration did not preserve arteriolar dilation to CGRP at 1 hour after ischemia, but responses were normal at 2 hours. CONCLUSIONS: Total global ischemia leads to prolonged attenuated dilator responses of cerebral arterioles to CGRP. In addition, indomethacin treatment alters effects of ischemia on CGRP-induced dilation.


Asunto(s)
Péptido Relacionado con Gen de Calcitonina/farmacología , Arterias Cerebrales/efectos de los fármacos , Arterias Cerebrales/fisiopatología , Ataque Isquémico Transitorio/fisiopatología , Vasodilatación , Vasodilatadores/farmacología , Animales , Animales Recién Nacidos , Antioxidantes/farmacología , Arteriolas/efectos de los fármacos , Arteriolas/fisiopatología , Inhibidores de la Ciclooxigenasa/farmacología , Femenino , Gliburida/farmacología , Indometacina/farmacología , Masculino , Bloqueadores de los Canales de Potasio , Prostaglandina-Endoperóxido Sintasas/farmacología , Especies Reactivas de Oxígeno/farmacología , Reperfusión , Daño por Reperfusión/fisiopatología , Superóxidos/antagonistas & inhibidores , Superóxidos/farmacología , Porcinos , Vasodilatación/efectos de los fármacos
16.
Chest ; 105(1): 224-8, 1994 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-8275735

RESUMEN

STUDY OBJECTIVES: The aim of the study was to identify risk factors for early onset pneumonia (EOP) in trauma patients, in order to seek possible intervention strategies. STUDY POPULATION: Participants included 124 consecutive trauma patients admitted to a general intensive care unit (ICU) of a university hospital from December 1990 to February 1992 inclusive. DATA COLLECTION: The following data were prospectively collected for each patient: demographics, severity of trauma according to the abbreviated injury scale (AIS), severity of coma according to the Glasgow coma scale (GCS), presence of pneumothorax, pulmonary contusion, rib fractures, hemothorax, and mechanical ventilation. All patients were monitored daily during the ICU stay for the onset of pneumonia, sepsis syndrome, septic shock, and adult respiratory distress syndrome (ARDS). Criteria for the diagnosis of pneumonia were: core temperature of greater than 38.3 degrees C, a WBC count of 10,000 cells/mm3, purulent tracheobronchial secretions, a worsening of pulmonary gas exchange, and persistent pulmonary infiltrates. All patients with suspected pneumonia underwent quantitative bronchoalveolar lavage (BAL) as well as blood cultures; BAL cultures were considered positive when they showed bacterial growth greater than 1 x 10(5) colony-forming unit (cfu)/ml, or less than 10(5), but with the same microorganism isolated in blood cultures. Pneumonia occurring within the first 96 h after trauma was considered EOP. DATA ANALYSIS: A stepwise logistic regression analysis was carried out in order to identify factors independently associated with an increased risk of EOP and late onset pneumonia (LOP). RESULTS: Overall mortality was 43.5 percent: mortality increased by age and AIS score. Forty one patients (33.1 percent) developed pneumonia: 26 (63.4 percent) were EOP and 15 (36.6 percent) were LOP. In the univariate analysis, an age greater than 40 years, the presence of pulmonary contusion, AIS of more than 4 for thorax and of more than 9 for abdomen, and the absence of mechanical ventilation (MV) during the first 4 days of hospitalization or MV lasting less than 24 h were significantly associated with an increased risk of acquiring EOP. Logistic regression analysis showed that the strongest risk factor for EOP was a combined severe abdominal and thoracic trauma, which increased the risk of EOP by 11 times; an age of more than 40 years and MV of less than 24 h during the first 4 days of hospitalization were also independent risk factors for EOP. Factors associated with LOP were an AIS score of more than 4 for abdomen and a length of MV of more than 5 days. CONCLUSION: In a trauma population, a combined severe abdominal and thoracic trauma represents a major risk factor for EOP. Mechanical ventilation administered during the first days after trauma seems to reduce the risk of EOP. As reported in previous studies, mechanical ventilatory support lasting more than 5 days is associated with an increased risk of LOP.


Asunto(s)
Traumatismo Múltiple/complicaciones , Neumonía/etiología , Escala Resumida de Traumatismos , Traumatismos Abdominales/complicaciones , Adulto , Anciano , Infecciones Bacterianas/diagnóstico , Líquido del Lavado Bronquioalveolar/química , Líquido del Lavado Bronquioalveolar/microbiología , Recuento de Colonia Microbiana , Contusiones/complicaciones , Cuidados Críticos , Femenino , Escala de Coma de Glasgow , Humanos , Lesión Pulmonar , Masculino , Persona de Mediana Edad , Neumonía/diagnóstico , Neumonía/microbiología , Estudios Prospectivos , Respiración Artificial , Síndrome de Dificultad Respiratoria/etiología , Factores de Riesgo , Tasa de Supervivencia , Traumatismos Torácicos/complicaciones
18.
Int J Clin Pharmacol Res ; 6(1): 61-7, 1986.
Artículo en Inglés | MEDLINE | ID: mdl-3082775

RESUMEN

Auranofin [S-triethylphosphine gold-2,3,4,6 tetra-O-acetyl-l-thio-beta-D-glucopyranoside) SK&F 39162) has been administered at 0.1-0.25 mg/kg/day as the sole remission-inducing drug to 46 children affected with juvenile chronic arthritis (JCA). There were 22 males and 24 females; 12 children were affected with pauciarticular onset JCA, 26 with polyarticular onset JCA and 8 with systemic onset JCA. Three sets of efficacy criteria were evaluated quarterly: eight clinical, (Ritchie Index, number of affected, swollen and limited joints, number of joint with increased temperature, morning stiffness, Steinbrocker functional class, physician's disease evaluation), three hematochemical and one therapeutical. In most patients a panel of immunological parameters was routinely performed inclusive of peripheral blood lymphocyte subsets, serum immunoglobulins and C3c-C4 complement components. Patients who showed a definite improvement of at least two out of the three orders of efficacy criteria were classified as responders to auranofin. Out of the 35 patients evaluable after at least six months of treatment there were 24 (68%) responders. Nonresponders had a basal higher level of serum IgA and a basal lower level of serum C4. Both responders and nonresponders presented a reduction of the T4/T8 ratio during auranofin treatment, while only in responders did the basal high levels of IgG and C3c show a definite decrease.


Asunto(s)
Antiinflamatorios/uso terapéutico , Artritis Juvenil/tratamiento farmacológico , Aurotioglucosa/análogos & derivados , Oro/análogos & derivados , Antiinflamatorios/efectos adversos , Artritis Juvenil/sangre , Artritis Juvenil/inmunología , Auranofina , Aurotioglucosa/efectos adversos , Aurotioglucosa/uso terapéutico , Niño , Preescolar , Complemento C3/análisis , Complemento C4/análisis , Femenino , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Lactante , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...