Estimación de la dinámica de líquidos intracraneales mediante análisis cuantitativo de imágenes de resonancia magnética de contraste de fase / Estimating intracranial fluid dynamics using quantitative analyses of phase contrast magnetic resonance images

ObjetivoEstimar las relaciones dinámicas entre los fluidos craneoespinales (líquido cefalorraquídeo [LCR] y sangre) en el espacio ventricular, subaracnoideo cerebral y subaracnoideo espinal mediante la cuantificación de imágenes de resonancia magnética (RM) en contraste de fase.Material y métodosSe analizaron 15 sujetos voluntarios sanos en la misma franja horaria y bajo la misma intensidad de campo (3T). Para cada estudio se realizaron 4 exploraciones en contraste de fase: 2 secuencias para el cálculo de LCR (acueducto de Silvio y espacio perimedular C2-C3) y 2 para el cálculo del flujo sanguíneo (arterias carótidas internas y vertebrales, seno sagital superior y recto). En todos los sujetos se calcularon los parámetros de amplitud (volumen sistólico, flujo promedio, índices de pulsatibilidad y distensibilidad, amplitud del gradiente de presión absoluta y relación de volumen de fluido de LCR por ciclo) y temporales (retrasos frente a la entrada de flujo arterial).ResultadosRespecto a la entrada de sangre arterial, el desplazamiento de sangre venosa (al 22 y 38% del ciclo cardíaco en los senos recto y sagital superior, respectivamente) y del LCR (al 12 y 25% de ciclo cardíaco en el espacio perimedular C2-C3 y el acueducto de Silvio, respectivamente) describen la distribución de la pulsatibilidad de los fluidos intracraneales. Se obtienen índices de distensibilidad para los compartimientos encefálico y medular en una población normal.ConclusionesMediante los mapas de velocidad de flujo obtenidos con RM es posible describir de manera cuantitativa las relaciones dinámicas de los fluidos intracraneales e inferir el comportamiento elástico encefálico y medular (AU)

ObjectiveTo estimate the dynamic relations between cerebrospinal fluid (CSF) and blood in the cerebral and spinal subarachnoid spaces and in the ventricles by quantifying phase contrast magnetic resonance imaging (MRI).Material and methodsWe analyzed 15 healthy volunteers during the same time of day and using the same magnetic field strength (3T). Each study consisted of four phase contrast sequences: two to calculate the CSF (aqueduct of Sylvius and the C2-C3 perimedullary space) and two to calculate the blood flow (internal carotid and vertebral arteries, superior sagittal sinus, and straight sinus). We calculated the amplitude parameters (systolic volume, mean flow, pulsatility and compliance indexes, absolute pressure gradient, and ratio of CSF volume per cycle) and temporal parameters (delays respect to arterial flow).ResultsWith respect to the input of arterial blood, the displacement of venous blood (22% and 38% of the cardiac cycle in the straight sinus and superior sagittal sinus, respectively) and of CSF (12% and 25% of the cardiac cycle in the C2-C3 perimedullary space and in the aqueduct of Sylvius, respectively) show the distribution of the pulsatility of the intracranial fluids. We calculated the indexes of compliance of the encephalic and medullary compartments in normal subjects.ConclusionsIt is possible to quantitatively describe the dynamic relations between intracranial fluids and infer the elastic behavior of the brain and spinal canal by using flow velocity maps obtained with phase contrast MRI (AU)

[Estimating intracranial fluid dynamics using quantitative analyses of phase contrast magnetic resonance images]. / Estimación de la dinámica de líquidos intracraneales mediante análisis cuantitativo de imágenes de resonancia magnética de contraste de fase.

OBJECTIVE: To estimate the dynamic relations between cerebrospinal fluid (CSF) and blood in the cerebral and spinal subarachnoid spaces and in the ventricles by quantifying phase contrast magnetic resonance imaging (MRI). MATERIAL AND METHODS: We analyzed 15 healthy volunteers during the same time of day and using the same magnetic field strength (3T). Each study consisted of four phase contrast sequences: two to calculate the CSF (aqueduct of Sylvius and the C2-C3 perimedullary space) and two to calculate the blood flow (internal carotid and vertebral arteries, superior sagittal sinus, and straight sinus). We calculated the amplitude parameters (systolic volume, mean flow, pulsatility and compliance indexes, absolute pressure gradient, and ratio of CSF volume per cycle) and temporal parameters (delays respect to arterial flow). RESULTS: With respect to the input of arterial blood, the displacement of venous blood (22% and 38% of the cardiac cycle in the straight sinus and superior sagittal sinus, respectively) and of CSF (12% and 25% of the cardiac cycle in the C2-C3 perimedullary space and in the aqueduct of Sylvius, respectively) show the distribution of the pulsatility of the intracranial fluids. We calculated the indexes of compliance of the encephalic and medullary compartments in normal subjects. CONCLUSIONS: It is possible to quantitatively describe the dynamic relations between intracranial fluids and infer the elastic behavior of the brain and spinal canal by using flow velocity maps obtained with phase contrast MRI.

[Experience of an interdisciplinary anesthesiology and nursing team for providing anesthesia outside the operating room]. / Experiencia de un equipo interdisciplinar de anestesiología y enfermería en un circuito de anestesia fuera de quirófano.

OBJECTIVE: To report on the creation and development of an interdisciplinary anesthesiology and nursing team to provide anesthesia outside the operating room. MATERIAL AND METHODS: We describe the creation of an interdisciplinary team and preanesthesia evaluation protocols for using nurses specializing in anesthesia for procedures outside the operating room. We analyzed the anesthetic procedures performed outside the operating room, the rate of suspensions due to failure of the procedure, and their impact on the rate of associated complications, from October 2006 to October 2007. RESULTS: Since the start of the project, 586 procedures outside the operating room have been performed. No suspensions or delays were observed that were due to comorbidity not detected in the preanesthesia evaluation carried out by the nurses. The incidences of complications and inadequate sedations were comparable to those reported for other similar interdisciplinary groups in this area. CONCLUSIONS: The creation of an interdisciplinary team of anesthesiologists and specialized nurses for providing anesthesia outside the operating room optimizes resources and improves routine clinical practice. It has allowed for universal preanesthesia evaluation, improved the distribution of resources, and proven a stimulus to the care-giving process.

[Normal values for cerebrospinal fluid flow dynamics in the aqueduct of Sylvius through optimized analysis of phase-contrast MR images]. / Valores de normalidad de la dinámica del flujo de líquido cefalorraquídeo en el acueducto de Silvio mediante análisis optimizado de imágenes de contraste de fase en resonancia magnética.

OBJECTIVE: To establish normal values for the different parameters that characterize the cerebrospinal fluid (CSF) flow dynamics in the aqueduct of Sylvius (velocity, flow, volume per cycle, and CSF production) obtained from phase-contrast MR images using a reliable and reproducible post-processing method. The optimized semiautomatic method eliminates interobserver variability and corrects errors due to low amplitude movements, aliasing, and the partial volume effect. MATERIAL AND METHODS: We studied 42 healthy subjects without neurological or cerebrovascular disease or disturbances in CSF dynamics. Images were acquired on a 1.5 T MR scanner using a phase-contrast sequence. All images were acquired during the same time frame (14:00 to 18:00) to avoid circadian influences. RESULTS: we obtained normal values for each of the parameters that characterize CSF dynamics in the aqueduct (maximum diastolic and systolic velocity, mean velocity, maximum diastolic and systolic flow, mean flow, production rate, and stroke volume). Although trends were noted, neither sex nor age (< 25, 26-50, >51 years old) had a statistically significant effect on any parameter (p> or =0.05). DISCUSSION: Although measurements of CSF flow dynamics parameter are sensitive to various factors (temporal and spatial resolutions of the MR sequence, circadian rhythms, age, sex, and MR equipment manufacturer), an optimized post-processing method enables reliable and reproducible values and ranges for normal subjects to be established.

Valores de normalidad de la dinámica del flujo de líquido cefalorraquídeo en el acueducto de Silvio mediante análisis optimizado de imágenes de contraste de fase en resonancia magnética / Normal values for cerebrospinal fluid flow dynamics in the aqueduct of Sylvius through optimized analysis of phase-contrast MR images

Objetivo: establecer valores de normalidad de los diferentes parámetros que caracterizan la dinámica del líquido cefalorraquídeo (LCR) en el acueducto de Silvio (velocidad, flujo, volumen por ciclo y producción), obtenidos de las imágenes de resonancia magnética (RM) por contraste de fase empleando un método de posproceso fiable y reproducible. El método semiautomático optimizado presenta una variabilidad nula de los resultados interobservador y corrige los errores debidos a los movimientos de baja amplitud, al submuestreo (aliasing) y al efecto del volumen parcial. Material y métodos: se analizó a 42 sujetos sanos sin alteraciones neurológicas, hidrocefalia ni enfermedades cerebrovasculares. Las imágenes se adquirieron en un equipo de RM de 1,5 T con una secuencia de contraste de fase. Todas las exploraciones se adquirieron en la misma franja horaria (de 14:00 a 18:00 h) para evitar influencias circadianas. Resultados: se obtuvieron valores de normalidad para cada uno de los parámetros que caracterizan la dinámica del LCR en el acueducto de Silvio (velocidades máximas diastólica y sistólica, velocidad promedio, flujos máximos diastólico y sistólico, flujo promedio, producción de LCR y volumen por ciclo). Aunque hubo una tendencia, ni el sexo ni la edad (< 25, 26-50 y > 51 años) influyeron estadísticamente en los parámetros calculados. Conclusiones: aunque las mediciones de los parámetros de la dinámica del flujo de LCR son sensibles a múltiples factores (resolución temporal y espacial de la secuencia RM, ritmo circadiano, edad y sexo, y fabricante del equipo de RM), un método optimizado de posproceso permite establecer valores y rangos de normalidad precisos y reproducibles (AU)

Objective: to establish normal values for the different parameters that characterize the cerebrospinal fluid (CSF) flow dynamics in the aqueduct of Sylvius (velocity, flow, volume per cycle, and CSF production) obtained from phase-contrast MR images using a reliable and reproducible post-processing method. The optimized semiautomatic method eliminates interobserver variability and corrects errors due to low amplitude movements, aliasing, and the partial volume effect. Material and methods: we studied 42 healthy subjects without neurological or cerebrovascular disease or disturbances in CSF dynamics. Images were acquired on a 1.5 T MR scanner using a phase-contrast sequence. All images were acquired during the same time frame (14:00 to 18:00) to avoid circadian influences. Results: we obtained normal values for each of the parameters that characterize CSF dynamics in the aqueduct (maximum diastolic and systolic velocity, mean velocity, maximum diastolic and systolic flow, mean flow, production rate, and stroke volume). Although trends were noted, neither sex nor age (< 25, 26-50, > 51 years old) had a statistically significant effect on any parameter (p ¡Ý 0.05). Discussion: although measurements of CSF flow dynamics parameter are sensitive to various factors (temporal and spatial resolutions of the MR sequence, circadian rhythms, age, sex, and MR equipment manufacturer), an optimized post-processing method enables reliable and reproducible values and ranges for normal subjects to be established (AU)

[Assessment of reliable quantification of the dynamics of cerebrospinal fluid by magnetic resonance imaging in idiopathic normal pressure hydrocephalus]. / Valoración de la cuantificación fiable de la dinámica del líquido cefalorraquídeo en el acueducto de Silvio mediante resonancia magnética en la hidrocefalia normopresiva idiopática.

INTRODUCTION: A combination of good clinical selection with reliable quantification of diverse parameters that characterize the dynamics of cerebrospinal fluid (CSF) flow from phase-contrast magnetic resonance imaging may identify patients with idiopathic normal pressure hydrocephalus (NPH). MATERIAL AND METHODS: We have carried out a quantitative analysis of 38 subjects (19 healthy subjects and 19 patients with suspected idiopathic NPH). The images were acquired using a 1.5 T MR unit with a phase-contrast sequence in an oblique-transversal plane perpendicular to the Sylvius aqueduct codified to 20 cm/s and with 27 observations per cardiac cycle by means of retrospective synchronization. The area was defined to half the height of the peak velocity, to maximize accuracy. Parameters quantified were mean flow, maximum systolic and diastolic flow, maximum systolic and diastolic velocity, mean velocity, CSF production and stroke volume. RESULTS: All the parameters measured showed a significant difference (ANOVA: p

Valoración de la cuantificación fiable de la dinámica del líquido cefalorraquídeo en el acueducto de Silvio mediante resonancia magnética en la hidrocefalia normopresiva idiopática / Assessment of reliable quantification of the dynamics of cerebrospinal fluid by magnetic resonance imaging in idiopathic normal pressure hydrocephalus

Introducción. Para identificar a pacientes con hidrocefalia normopresiva (HNP) idiopática es necesario combinar una buena selección clínica con la cuantificación fiable de diversos parámetros que caracterizan la dinámica del líquido cefalorraquídeo (LCR) en las imágenes por resonancia magnética (RM) obtenidas en contraste de fase. Material y métodos. Se realizó un análisis cuantitativo a 38 sujetos (19 pacientes con sospecha de HNP idiopática y 19 controles). Las imágenes se adquirieron usando un equipo de RM de 1,5 T con una secuencia contraste de fase perpendicular al acueducto de Silvio, codificada a 20 cm/s y con 27 lecturas por ciclo cardíaco mediante sincronización retrospectiva. Se definió el área del acueducto a mitad de la altura del pico de velocidad para maximizar la precisión. Los parámetros cuantificados fueron el flujo promedio, flujo máximo sistólico y diastólico, velocidad máxima sistólica y diastólica, velocidad promedio, producción de LCR y volumen por ciclo.Resultados. Todos los parámetros medidos presentaron una diferencia significativa (ANOVA: p <= 0,05) entre controles y pacientes, excepto la velocidad máxima sistólica (p=0,17). En el análisis discriminante se observó que los dos grupos (controles y pacientes) fueron clasificados correctamente en un 92,1% con el uso del flujo máximo sistólico y la producción de LCR.Conclusiones. La cuantificación semiautomática de la dinámica del LCR mediante RM diferencia a los pacientes con estado hiperdinámico de los sujetos control, con diferencias significativas que pueden usarse para clasificar las HNP idiopáticas

Introduction. A combination of good clinical selection with reliable quantification of diverse parameters that characterize the dynamics of cerebrospinal fluid (CSF) flow from phase-contrast magnetic resonance imaging may identify patients with idiopathic normal pressure hydrocephalus (NPH). Material and methods. We have carried out a quantitative analysis of 38 subjects (19 healthy subjects and 19 patients with suspected idiopathic NPH). The images were acquired using a 1.5 T MR unit with a phase-contrast sequence in an oblique-transversal plane perpendicular to the Sylvius aqueduct codified to 20 cm/s and with 27 observations per cardiac cycle by means of retrospective synchronization. The area was defined to half the height of the peak velocity, to maximize accuracy. Parameters quantified were mean flow, maximum systolic and diastolic flow, maximum systolic and diastolic velocity, mean velocity, CSF production and stroke volume. Results. All the parameters measured showed a significant difference (ANOVA: p<=0,05) between controls and patient except for the maximum systolic velocity (p=0.17). It was observed in the discriminant analysis that the two groups (controls and patients) were classified correctly in 92.1% with the use of the maximum systolic flow and CSF production. Conclusions. Semiautomatic quantification of the dynamics of CSF by means of MRI differentiates patients with hyperdynamic state from the control subjects, with significant differences that can be used to classify idiopathic HNP

Improved characterization of FSHD mutations.

Facioscapulohumeral muscular dystrophy (FSHD) is caused by the shortest alleles of the 3.3kb-tandem repeat array D4Z4 at 4q35. Molecular diagnosis of FSHD depends upon the separation of unusually large alleles by pulse-field electrophoresis after EcoRI and EcoRI/BlnI digestion. The exact number of alleles could not however be directly inferred from the size of DNA fragments owing to polymorphisms in the telomeric region of the locus. Knowing the exact repeat number of disease causing alleles may benefit genetic counselling, help to understand the mechanism of this singular disease and the population dynamics of subtelomeric sequences variations. We present here a partial digestion mapping method giving the exact number of repeats for disease causing alleles, and we suggest that most inaccuracies induced by common polymorphisms could be reduced by using EcoRV in place of EcoRI. After studying more than 300 DNA samples with both the standard method and this new method, we show that alleles size can be evaluated with a precision of less than one half repeat, and that the variations in length of the truncated repeat in the telomeric region of the D4Z4 locus can be evaluated. The results suggest that at least one intact chromosome 4 type repeat at 4q35 is needed to cause FSHD.

Seasonality of Tylenchulus semipenetrans Cobb and Pasteuria sp. in Citrus Orchards in Spain.

Population densities of the Mediterranean biotype of Tylenchulus semipenetrans were monitored in soil and citrus roots at 3-month intervals for 3 consecutive years in four citrus orchards in the provinces of Tarragona (Amposta and Xalamera) and Valencia (Moncada and Ca rcer). Nematode population densities in soil peaked once a year in April or July depending on the orchard and year. Numbers of females per gram of root increased once or twice each year. The maximum density of eggs per gram of root was recorded in April at Xalamera and Ca rcer orchards, but there was no recognizable peak in the other two orchards. Numbers of nematodes in soil, females or eggs per gram of root, or eggs per female were correlated with either temperature or rainfall in the sampling month, 1 month before sampling, or in the second preceding month, depending on the orchard. Members of the Pasteuria group were present in the four citrus orchards, and a positive relationship occurred between nematodes in soil and bacterial parasitism (r(2) = 0.75) in the orchard at Amposta.

Genetic analysis of apomixis in Citrus and Poncirus by molecular markers.

Propagation of citrus rootstocks depends upon the production of clonal plants from nucellar seedlings. This makes apomixis one of the host important traits in breeding programs for citrus rootstocks. The genetic control of apomixis was studied in a 50-tree progeny derived from the cross C. volkameriana×P. trifoliata using 69 molecular markers and bulked segregant analysis. The proportion of nucellar seedlings was estimated by isoenzymatic analysis of 25 seedlings per tree for 2 consecutive years. The type of embryony (polyembryonic versus monoembryonic seeds) was also determined for fruit-yielding trees. Separate genetic maps for each parental species were developed. The integration and comparison of these maps could be accomplished using common multiallelic segregant loci. Differences in gene synteny between the two species-specific genetic maps were shown. Important distortions in the segregation of markers at several genomic regions, some of them also involving differences in the C-methylation pattern, have been observed, especially for the pollen parent. Analysis of quantitative trait loci (QTLs) revealed the presence of six genomic positions (two in P. trifoliata and four in C. volkameriana) contributing individually up to 24% of the total variation for apomixis. Within the same species, QTLs with positive and negative allele effects were present, even in the same linkage group. One of the markers associated to apomixis (Apo2) is also associated to embryony type. Therefore, the genetic control of apomictic reproduction found in citrus (nucellar embryony) is quite complex compared to what has been reported for gametophytic apomixis. Molecular markers linked to QTLs governing apomixis will be useful to assist selection of future apomictic rootstocks for citrus varieties.

A gene for non-specific X-linked mental retardation (MRX55) is located in Xp11.

A new family with a non-specific X-linked mental retardation (MRX55) is described. An X-linked recessive inheritance is suggested by the segregation from two healthy transmitting females of moderate mental retardation in three males, without any specific clinical, radiological or biological features. Two point linkage analysis demonstrated significant linkage between the disorder and several markers in Xp11 (Zmax = 2.11, theta = 0); multipoint linkage analyses confirmed the significant linkage with a maximum lod score (Z = 2.11 at theta = 0, at DXS8012). Recombination events observed with the flanking markers DXS1068 and DXS1275 delineate a 34 centimorgan interval in the pericentromeric region. The interval of assignment pointed out in this family overlaps with several MRX loci previously reported in Xp11 which are reviewed here in.

The female paraplegic in Spain: preliminary report.

A survey has been made of 70 out of the 166 female paraplegic and tetraplegic patients treated at the Spinal Unit of La Fe Hospital of Valencia in order to record the aetiology, main medical problems, domestic resettlement, functional, social and industrial rehabilitation of the patients. The results are discussed.

Lung volumes and mechanics of breathing in tetraplegics.

The purpose of this study was to investigate the influence of the paralysis of some respiratory muscles, due to a spinal cord lesion, on the lung volumes and the mechanics of breathing, specially on the maximal expiratory flows. Fifty-two tetraplegics have been studied, divided in two groups--according to the level of the lesion to investigate if there is any difference in the behaviour of both groups.

The para-articular ossifications in our paraplegics and tetraplegics: a survey of 704 patients.

The X-ray examination of 704 spinal cord injured patients have showed that in 20 per cent of the cases para-articular ossifications were present most frequently in the hips. They were less frequently found in non-traumatic and incomplete cases. No other clear relationship was found.

Higiene y sanidad

Las medidas higiénico-sanitarias que deben aplicarse en el procesamiento de productos carneos, surgen de observaciones realizadas en la práctica. En esta etapa experimental se constata si dichas medidas son aplicables al proceso productivo normal. Asimismo se evalúa hasta que punto garantizan en conjunción con la tecnología actual una mejor calidad del producto, y en consecuencia prolongan la vida util de las proteínas rojas. Las medidas de higiene y sanidad tratan de evitar que la carne sirva de medio de cultivo para microorganismos causantes de toxiinfecciones alimentarias, o de otro tipo de deterioro, que sean motivo de decomiso. Además del deterioro de origen microbiano, la presencia de elementos extraños harán peligrar la aptitud del producto para su consumo

Higiene y sanidad

Las medidas higiénico-sanitarias que deben aplicarse en el procesamiento de productos carneos, surgen de observaciones realizadas en la práctica. En esta etapa experimental se constata si dichas medidas son aplicables al proceso productivo normal. Asimismo se evalúa hasta que punto garantizan en conjunción con la tecnología actual una mejor calidad del producto, y en consecuencia prolongan la vida util de las proteínas rojas. Las medidas de higiene y sanidad tratan de evitar que la carne sirva de medio de cultivo para microorganismos causantes de toxiinfecciones alimentarias, o de otro tipo de deterioro, que sean motivo de decomiso. Además del deterioro de origen microbiano, la presencia de elementos extraños harán peligrar la aptitud del producto para su consumo

The flow-volume loop in tetraplegics.

We have studied the FVC and maximum flow-volume loop in 20 tetraplegics and the results have been compared with the predicted normal values. The FVC in sitting position is reduced at approximately half the normal predicted values and is significantly lower than in supine and Trendelenburg. At high lung volumes the flows are reduced at half the normal values. At low lung volumes the reduction is smaller (71.5 per cent).