Adaptaciones cardiacas hemodinámicas, estructurales y funcionales a un programa de ejercicio físico supervisado durante el embarazo: ensayo clínico aleatorizado = Hemodynamic, structural and functional cardiac adaptations in a supervised physical exercise program during pregnancy: a randomized controlled trial

Introducción: Diversos cambios ocurren en el sistema cardiovascular materno durante el embarazo, lo que genera un gran estrés sobre este sistema especialmente durante el tercer trimestre, pudiendo acentuarse en presencia de determinados factores de riesgo. Los objetivos de este estudio fueron, valorar las adaptaciones cardiovasculares producidas por un programa específico de ejercicio físico; su seguridad sobre el sistema cardiovascular materno y los resultados del embarazo; y su eficacia en el control de los factores de riesgo cardiovascular. Material y métodos: El diseño del estudio fue un ensayo clínico aleatorizado. 151 gestantes sanas fueron evaluadas mediante un ecocardiograma y un electrocardiograma en la semana 20 y 34 de gestación. Un total de 89 gestantes participaron en un programa de ejercicio físico (GE) desde el primer hasta el tercer trimestre de embarazo, constituido principalmente por 25-30 minutos de trabajo aeróbico (55-60% de la frecuencia cardiaca de reserva), trabajo de fortalecimiento general y específico, y un trabajo de tonificación del suelo pélvico; desarrollado 3 días a la semana con una duración de 55-60 minutos cada sesión. Las gestantes aleatoriamente asignadas al grupo de control (GC; n=62) permanecieron sedentarias durante el embarazo. El estudio fue aprobado por el Comité Ético de investigación clínica del Hospital Universitario de Fuenlabrada. Resultados: Las características basales fueron similares entre ambos grupos. A diferencia del GC, las gestantes del GE evitaron el descenso significativo del gasto cardiaco indexado, entre el 2º y 3ºT de embarazo, y conservaron el patrón geométrico normal del ventrículo izquierdo; mientras que en el GC cambió hacia un patrón de remodelado concéntrico. En la semana 20, las gestantes del GE presentaron valores significativamente menores de frecuencia cardiaca (GC: 79,56±10,76 vs. GE: 76,05±9,34; p=0,04), tensión arterial sistólica (GC: 110,19±10,23 vs. GE: 106,04±12,06; p=0,03); tensión arterial diastólica (GC: 64,56±7,88 vs. GE: 61,81±7,15; p=0,03); tiempo de relajación isovolumétrica (GC: 72,94±14,71 vs. GE: 67,05±16,48; p=0,04); y un mayor tiempo de deceleración de la onda E (GC: 142,09±39,11 vs. GE: 162,10±48,59; p=0,01). En la semana 34, el GE presentó valores significativamente superiores de volumen sistólico (GC: 51,13±11,85 vs. GE: 56,21±12,79 p=0,04), de llenado temprano del ventrículo izquierdo (E) (GC: 78,38±14,07 vs. GE: 85,30±16,62; p=0,02) y de tiempo de deceleración de la onda E (GC: 130,35±37,11 vs. GE: 146,61±43,40; p=0,04). Conclusión: La práctica regular de ejercicio físico durante el embarazo puede producir adaptaciones positivas sobre el sistema cardiovascular materno durante el tercer trimestre de embarazo, además de ayudar en el control de sus factores de riesgo, sin alterar la salud materno-fetal. ABSTRACT Background: Several changes occur in the maternal cardiovascular system during pregnancy. These changes produce a considerable stress in this system, especially during the third trimester, which can be increased in presence of some risk factors. The aims of this study were, to assess the maternal cardiac adaptations in a specific exercise program; its safety on the maternal cardiovascular system and pregnancy outcomes; and its effectiveness in the control of cardiovascular risk factors. Material and methods: A randomized controlled trial was designed. 151 healthy pregnant women were assessed by an echocardiography and electrocardiography at 20 and 34 weeks of gestation. A total of 89 pregnant women participated in a physical exercise program (EG) from the first to the third trimester of pregnancy. It consisted of 25-30 minutes of aerobic conditioning (55-60% of their heart rate reserve), general and specific strength exercises, and a pelvic floor muscles training; 3 times per weeks during 55-60 minutes per session. Pregnant women randomized allocated to the control group (CG) remained sedentary during pregnancy. The study was approved by the Research Ethics Committee of Hospital Universitario de Fuenlabrada. Results: Baseline characteristics were similar between groups. Difference from the CG, pregnant women from the EG prevented the significant decrease of the cardiac output index, between the 2nd and 3rd trimester of pregnancy, and preserved the normal left ventricular pattern; whereas in the CG shifted to concentric remodeling pattern. At 20 weeks, women in the EG had significant lower heart rate (CG: 79,56±10,76 vs. EG: 76,05±9,34; p=0,04), systolic blood pressure (CG: 110,19±10,23 vs. EG: 106,04±12,06; p=0,03); diastolic blood pressure (CG: 64,56±7,88 vs. EG: 61,81±7,15; p=0,03); isovolumetric relaxation time (GC: 72,94±14,71 vs. GE: 67,05±16,48; p=0,04); and a higher deceleration time of E Wave (GC: 142,09±39,11 vs. GE: 162,10±48,59; p=0,01). At 34 weeks, the EG had a significant higher stroke volume (CG: 51,13±11,85 vs. EG: 56,21±12,79 p=0,04), early filling of left ventricular (E) (CG: 78,38±14,07 vs. EG: 85,30±16,62; p=0,02) and deceleration time of E wave (CG: 130,35±37,11 vs. EG:146,61±43,40; p=0,04). Conclusion: Physical regular exercise program during pregnancy may produce positive maternal cardiovascular adaptations during the third trimester of pregnancy. In addition, it helps to control the cardiovascular risk factors without altering maternal and fetus health.

Bases para un diseño metodológico de estimulación binaural como terapia acústica en neurología

La medicina y la ingeniería del siglo XXI han dado como fruto numerosos avances para la sociedad aunque en la mayoría de los casos los tratamientos suelen ser costosos e invasivos. La educación que recibe la sociedad sobre la salud es escasa, ya que sólo vamos al médico cuando realmente estamos enfermos. Este trabajo presenta nuestra apuesta por las terapias complementarias, para el desarrollo de una metodología terapéutica no invasiva y con un costo muy bajo. La finalidad de esta Tesis, que se enmarca en un equipo multidisciplinar, fruto de la estrecha colaboración en el que participan psicopedagogos, ingenieros y médicos, es perfilar una metodología que luego pueda ser aplicable a patologías neurológicas. Aquí, dejamos sentadas las bases. Faltarán nuevos investigadores que continúen este camino para tener una base de datos lo suficientemente extensa de registros de sujetos que hayan sido sometidos a terapia binaural, para poder sacar unas conclusiones sólidas. La aportación de esta Tesis deja cubierta la aplicación, selección, procesado de señal y desarrollo de algoritmos, test cognitivos indicados para el caso específico que nos ocupa, cálculo de incertidumbre del sistema utilizado para la aplicación del estímulo y desarrollo de un test psicoacústico específico. EL empleo del sonido en medicina como es la musicoterapia o sonoterapia ha experimentado una gran difusión en los últimos años, más de 100.000 nuevas citas bibliográficas han aparecido con respecto al año anterior. Sin embargo, son escasísimas las que hacen referencia a las características físico acústicas del sonido empleado, tan sólo hemos encontrado una par de ellas que correlacionan las características físicas del sonido con el tipo de respuesta terapéutica. No encontramos citas bibliográficas específicas que planteen un modelo experimental científico capaz de reproducir las mismas respuestas ante los mismos parámetros y estímulos. En esta Tesis proponemos el uso de estimulación sonora binaural, que consiste en la utilización de dos tonos puros idénticos pero ligeramente diferentes en frecuencia que se presentan de manera separada cada uno en un oído, como consecuencia, la persona que recibe la estimulación percibe un tercer tono, llamado tono binaural, formado por la diferencia de frecuencia de ambos variando su amplitud. Existen estudios que sugieren que dichas frecuencias binaurales pueden modificar los patrones eléctricos de la actividad cerebral y los niveles de arousal, conociéndose en la literatura bajo el nombre de “entrainment”. Tras la revisión bibliográfica del estado del arte, podemos concluir que es necesario el desarrollo de estudios doble ciego bien diseñados, con el objetivo de establecer una base sólida sobre los efectos de este tipo de estimulación, ya que la mayoría de los beneficios documentados se refieren a muestras muy pequeñas y con poco rigor científico, siendo los resultados positivos obtenidos debidos al efecto placebo. La tecnología binaural es barata siendo cualquier avance en esta dirección de interés público. El objetivo concreto de la investigación es estudiar el potencial de las ondas binaurales en un área en particular: tareas que requieren atención y concentración. Se busca obtener cualquier cambio en las ondas cerebrales que se puedan correlar con la mejoras. A la vista de los resultados de estas investigaciones se intentará aplicar esta metodología en neuropatologías que presenten alguna deficiencia en el área de atención como es el Trastorno de espectro Autista. En esta Tesis presentamos los resultados de dos estudios independientes, el primero para sentar las bases del método (tiempos, diseño de estimulaciones, procesado) en una muestra de 78 adultos sanos, el segundo a partir de los resultados obtenidos en el primero, afinando la metodología y para un grupo de 20 niños entre 8 y 12 años, los resultados del segundo estudio sirven para justificar su aplicación en niños con TEA que presenten déficit de atención. ABSTRACT Medicine and engineering in the 21st century have resulted in advances for society but in most cases the treatments are often costly and invasive. The health education society receive is scarce, since only go to the doctor when we are really sick. With this work I present my commitment to complementary therapies, my little grain of sand in the development of a noninvasive therapeutic approach and very low cost, well and can be used in a preventive manner resulting in a society with less sick. The purpose of this thesis is to outline a methodology that can then be applied to neurological diseases, here we lay the groundwork. New researchers are needed to continue this path for a sufficiently extensive records database of subjects who have undergone binaural therapy, and so to draw firm conclusions. The contribution of this thesis includes: the application, selection, signal processing and algorithm development, indicated cognitive tests for the specific case at hand, calculation of system uncertainty of the system and development of a specific psychoacoustic test. The use of sound in medicine, such as music therapy or sound therapy has experienced a great diffusion in recent years, more than 100,000 new citations have appeared over the previous year but very few are those referring to acoustic physical characteristics of sound employee, we have only found a couple of them that physical sound characteristics are correlated with the therapeutic response. We found no specific citations posing a scientific experimental model capable of reproducing the same answers to the same parameters and stimuli. In this thesis we propose the use of binaural sound stimulation which involves the use of two identical but slightly different in frequency pure tones presented separately each in one ear, as a result the subject perceives a third tone, called binaural tone, formed by the difference in frequency with amplitude variations Studies suggest that these binaural frequencies can modify the electrical patterns of brain activity and arousal levels, being known in the literature under the name of “entrainment”. After the literature review of the state of the art, we conclude, it is necessary to develop well-designed double-blind studies, in order to establish a solid foundation on the effects of such stimulation, since most of the documented benefits relate to very small samples and unscientific may be obtained positive results due to the placebo effect. The binaural technology is cheap being any progress in this direction in the public interest. The specific objective of the research is to study the potential of binaural waves in a particular area: tasks requiring attention and concentration also we want to get any change in brain waves that can correlate with improvements. In view of the results of this research we seek to apply this methodology in neuropathology presenting any deficiency in the area of attention such as Autism Spectrum Disorder. In this thesis we present the results of two independent studies, the first to lay the foundation of the method (times, stimulation design, processing) in a sample of 78 healthy adults, the second from the results obtained in the first, refine the methodology for a group of 20 children between 8 and 12 years, the results of the second study used to justify its use in children with ASD that present attention deficit.

Characterization of Cavities Using the GPR, LIDAR and GNSS Techniques

The study of the many types of natural and manmade cavities in different parts of the world is important to the fields of geology, geophysics, engineering, architectures, agriculture, heritages and landscape. Ground-penetrating radar (GPR) is a noninvasive geodetection and geolocation technique suitable for accurately determining buried structures. This technique requires knowing the propagation velocity of electromagnetic waves (EM velocity) in the medium. We propose a method for calibrating the EM velocity using the integration of laser imaging detection and ranging (LIDAR) and GPR techniques using the Global Navigation Satellite System (GNSS) as support for geolocation. Once the EM velocity is known and the GPR profiles have been properly processed and migrated, they will also show the hidden cavities and the old hidden structures from the cellar. In this article, we present a complete study of the joint use of the GPR, LIDAR and GNSS techniques in the characterization of cavities. We apply this methodology to study underground cavities in a group of wine cellars located in Atauta (Soria, Spain). The results serve to identify construction elements that form the cavity and group of cavities or cellars. The described methodology could be applied to other shallow underground structures with surface connection, where LIDAR and GPR profiles could be joined, as, for example, in archaeological cavities, sewerage systems, drainpipes, etc.

Infrared thermography and shoulder pain in wheelchair users = Termografía infrarroja y dolor de hombro en usuarios de sillas de ruedas

Las personas que usan la silla de ruedas como su forma de movilidad prioritaria presentan una elevada incidencia (73%) de dolor de hombro debido al sobreuso y al movimiento repetitivo de la propulsión. Existen numerosos métodos de diagnóstico para la detección de las patologías del hombro, sin embargo la literatura reclama la necesidad de un test no invasivo y fiable, y sugiere la termografía como una técnica adecuada para evaluar el dolor articular. La termografía infrarroja (IRT) proporciona información acerca de los procesos fisiológicos a través del estudio de las distribuciones de la temperatura de la piel. Debido a la alta correlación entre ambos lados corporales, las asimetrías térmicas entre flancos contralaterales son una buena indicación de patologías o disfunciones físicas subyacentes. La fiabilidad de la IRT ha sido estudiada con anterioridad en sujetos sanos, pero nunca en usuarios de sillas de ruedas. Las características especiales de la población con discapacidad (problemas de sudoración y termorregulación, distribución sanguínea o medicación), hacen necesario estudiar los factores que afectan a la aplicación de la IRT en usuarios de sillas de ruedas. La bibliografía discrepa en cuanto a los beneficios o daños resultantes de la práctica de la actividad física en las lesiones de hombro por sobreuso en usuarios de sillas de ruedas. Recientes resultados apuntan a un aumento del riesgo de rotura del manguito rotador en personas con paraplejia que practican deportes con elevación del brazo por encima de la cabeza. Debido a esta falta de acuerdo en la literatura, surge la necesidad de analizar el perfil termográfico en usuarios de sillas de ruedas sedentarios y deportistas y su relación con el dolor de hombro. Hasta la fecha sólo se han publicado estudios termográficos durante el ejercicio en sujetos sanos. Un mayor entendimiento de la respuesta termográfica al ejercicio en silla de ruedas en relación al dolor de hombro clarificará su aparición y desarrollo y permitirá una apropiada intervención. El primer estudio demuestra que la fiabilidad de la IRT en usuarios de sillas de ruedas varía dependiendo de las zonas analizadas, y corrobora que la IRT es una técnica no invasiva, de no contacto, que permite medir la temperatura de la piel, y con la cual avanzar en la investigación en usuarios de sillas de ruedas. El segundo estudio proporciona un perfil de temperatura para usuarios de sillas de ruedas. Los sujetos no deportistas presentaron mayores asimetrías entre lados corporales que los sedentarios, y ambos obtuvieron superiores asimetrías que los sujetos sin discapacidad reportados en la literatura. Los no deportistas también presentaron resultados más elevados en el cuestionario de dolor de hombro. El área con mayores asimetrías térmicas fue hombro. En deportistas, algunas regiones de interés (ROIs) se relacionaron con el dolor de hombro. Estos resultados ayudan a entender el mapa térmico en usuarios de sillas de ruedas. El último estudio referente a la evaluación de la temperatura de la piel en usuarios de sillas de ruedas en ejercicio, reportó diferencias significativas entre la temperatura de la piel antes del test y 10 minutos después del test de propulsión de silla de ruedas, en 12 ROIs; y entre el post-test y 10 minutos después del test en la mayoría de las ROIs. Estas diferencias se vieron atenuadas cuando se compararon las asimetrías antes y después del test. La temperatura de la piel tendió a disminuir inmediatamente después completar el ejercicio, e incrementar significativamente 10 minutos después. El análisis de las asimetrías vs dolor de hombro reveló relaciones significativas negativas en 5 de las 26 ROIs. No se encontraron correlaciones significativas entre las variables de propulsión y el cuestionario de dolor de hombro. Todas las variables cinemáticas correlacionaron significativamente con las asimetrías en múltiples ROIs. Estos resultados indican que los deportistas en sillas de ruedas exhiben una capacidad similar de producir calor que los deportistas sin discapacidad; no obstante, su patrón térmico es más característico de ejercicios prolongados que de esfuerzos breves. Este trabajo contribuye al conocimiento de la termorregulación en usuarios de sillas de ruedas durante el ejercicio, y aporta información relevante para programas deportivos y de rehabilitación. ABSTRACT Individuals who use wheelchairs as their main means of mobility have a high incidence (73%) of shoulder pain (SP) owing to overuse and repetitive propulsion movement. There are numerous diagnostic methods for the detection of shoulder pathologies, however the literature claims that a noninvasive accurate test to properly assess shoulder pain would be necessary, and suggests thermography as a suitable technique for joint pain evaluation. Infrared thermography (IRT) provides information about physiological processes by studying the skin temperature (Tsk) distributions. Due to the high correlation of skin temperature between both sides of the body, thermal asymmetries between contralateral flanks are an indicator of underlying pathologies or physical dysfunctions. The reliability of infrared thermography has been studied in healthy subjects but there are no studies that have analyzed the reliability of IRT in wheelchair users (WCUs). The special characteristics of people with disabilities (sweating and thermoregulation problems, or blood distribution) make it necessary to study the factors affecting the application of IRT in WCUs. Discrepant reports exist on the benefits of, or damage resulting from, physical exercise and the relationship to shoulder overuse injuries in WCUs. Recent findings have found that overhead sports increase the risk of rotator cuff tears in wheelchair patients with paraplegia. Since there is no agreement in the literature, the thermographic profile of wheelchair athletes and nonathletes and its relation with shoulder pain should also be analysed. Infrared thermographic studies during exercise have been carried out only with able-bodied population at present. The understanding of the thermographic response to wheelchair exercise in relation to shoulder pain will offer an insight into the development of shoulder pain, which is necessary for appropriate interventions. The first study presented in this thesis demonstrates that the reliability of IRT in WCUs varies depending on the areas of the body that are analyzed. Moreover, it corroborates that IRT is a noninvasive and noncontact technique that allows the measurement of Tsk, which will allow for advances to be made in research concerned with WCUs. The second study provides a thermal profile of WCUs. Nonathletic subjects presented higher side-to-side skin temperature differences (ΔTsk) than athletes, and both had greater ΔTsk than the able-bodied results that have been published in the literature. Nonathletes also revealed larger Wheelchair Users Shoulder Pain Index (WUSPI) score than athletes. The shoulder region of interest (ROI) was the area with the highest ΔTsk of the regions measured. The analysis of the athletes’ Tsk showed that some ROIs are related to shoulder pain. These findings help to understand the thermal map in WCUs. Finally, the third study evaluated the thermal response of WCUs in exercise. There were significant differences in Tsk between the pre-test and the post-10 min in 12 ROIs, and between the post-test and the post-10 in most of the ROIs. These differences were attenuated when the ΔTsk was compared before and after exercise. Skin temperature tended to initially decrease immediately after the test, followed by a significant increase at 10 minutes after completing the exercise. The ΔTsk versus shoulder pain analysis yielded significant inverse relationships in 5 of the 26 ROIs. No significant correlations between propulsion variables and the results of the WUSPI questionnaire were found. All kinematic variables were significantly correlated with the temperature asymmetries in multiple ROIs. These results present indications that high performance wheelchair athletes exhibit similar capacity of heat production to able-bodied population; however, they presented a thermal pattern more characteristic of a prolonged exercise rather than brief exercise. This work contributes to improve the understanding about temperature changes in wheelchair athletes during exercise and provides implications to the sports and rehabilitation programs.

Análisis espectral de señales cardiacas mediante frecuencia dominante

La Ingeniería Biomédica surgió en la década de 1950 como una fascinante mezcla interdisciplinaria, en la cual la ingeniería, la biología y la medicina aunaban esfuerzos para analizar y comprender distintas enfermedades. Las señales existentes en este área deben ser analizadas e interpretadas, más allá de las capacidades limitadas de la simple vista y la experiencia humana. Aquí es donde el procesamiento digital de la señal se postula como una herramienta indispensable para extraer la información relevante oculta en dichas señales. La electrocardiografía fue una de las primeras áreas en las que se aplicó el procesado digital de señales hace más de 50 años. Las señales electrocardiográficas continúan siendo, a día de hoy, objeto de estudio por parte de cardiólogos e ingenieros. En esta área, las técnicas de procesamiento de señal han ayudado a encontrar información oculta a simple vista que ha cambiado la forma de tratar ciertas enfermedades que fueron ya diagnosticadas previamente. Desde entonces, se han desarrollado numerosas técnicas de procesado de señales electrocardiográficas, pudiéndose resumir estas en tres grandes categorías: análisis tiempo-frecuencia, análisis de organización espacio-temporal y separación de la actividad atrial del ruido y las interferencias. Este proyecto se enmarca dentro de la primera categoría, análisis tiempo-frecuencia, y en concreto dentro de lo que se conoce como análisis de frecuencia dominante, la cual se va a aplicar al análisis de señales de fibrilación auricular. El proyecto incluye una parte teórica de análisis y desarrollo de algoritmos de procesado de señal, y una parte práctica, de programación y simulación con Matlab. Matlab es una de las herramientas fundamentales para el procesamiento digital de señales por ordenador, la cual presenta importantes funciones y utilidades para el desarrollo de proyectos en este campo. Por ello, se ha elegido dicho software como herramienta para la implementación del proyecto. ABSTRACT. Biomedical Engineering emerged in the 1950s as a fascinating interdisciplinary blend, in which engineering, biology and medicine pooled efforts to analyze and understand different diseases. Existing signals in this area should be analyzed and interpreted, beyond the limited capabilities of the naked eye and the human experience. This is where the digital signal processing is postulated as an indispensable tool to extract the relevant information hidden in these signals. Electrocardiography was one of the first areas where digital signal processing was applied over 50 years ago. Electrocardiographic signals remain, even today, the subject of close study by cardiologists and engineers. In this area, signal processing techniques have helped to find hidden information that has changed the way of treating certain diseases that were already previously diagnosed. Since then, numerous techniques have been developed for processing electrocardiographic signals. These methods can be summarized into three categories: time-frequency analysis, analysis of spatio-temporal organization and separation of atrial activity from noise and interferences. This project belongs to the first category, time-frequency analysis, and specifically to what is known as dominant frequency analysis, which is one of the fundamental tools applied in the analysis of atrial fibrillation signals. The project includes a theoretical part, related to the analysis and development of signal processing algorithms, and a practical part, related to programming and simulation using Matlab. Matlab is one of the fundamental tools for digital signal processing, presenting significant functions and advantages for the development of projects in this field. Therefore, we have chosen this software as a tool for project implementation.

Mealiness Detection in Agricultural Crops: Destructive and Nondestructive Tests: A Review

Mealiness is known as an important internal quality attribute of fruits/vegetables, which has significant influence on consumer purchasing decisions. Mealiness has been a topic of research interest over the past several decades. A number of destructive and nondestructive techniques are introduced for mealiness detection. Nondestructive methods are more interesting because they are rapid, noninvasive, and suitable for real-time purposes. In this review, the concept of mealiness is presented for potato, apple, and peach, followed by an in-depth discussion about applications of destructive and nondestructive techniques developed for mealiness detection. The results suggest the potential of electromagnetic-based techniques for nondestructive mealiness evaluation. Further investigations are in progress to find more appropriate nondestructive techniques as well as cost and performance.

Low-Intensity Pulsed Ultrasound Improves the Functional Properties of Cardiac Mesoangioblasts

Cell-based therapy is a promising approach for many diseases, including ischemic heart disease. Cardiac mesoangioblasts are committed vessel-associated progenitors that can restore to a significant, although partial, extent, heart structure and function in a murine model of myocardial infarction. Low-intensity pulsed ultrasound (LIPUS) is a noninvasive form of mechanical energy that can be delivered into biological tissues as acoustic pressure waves, and is widely used for clinical applications including bone fracture healing. We hypothesized that the positive effects of LIPUS on bone and soft tissue, such as increased cell differentiation and cytoskeleton reorganization, could be applied to increase the therapeutic potential of mesoangioblasts for heart repair. In this work, we show that LIPUS stimulation of cardiac mesoangioblasts isolated from mouse and human heart results in significant cellular modifications that provide beneficial effects to the cells, including increased malleability and improved motility. Additionally, LIPUS stimulation increased the number of binucleated cells and induced cardiac differentiation to an extent comparable with 5´-azacytidine treatment. Mechanistically, LIPUS stimulation activated the BMP-Smad signalling pathway and increased the expression of myosin light chain-2 together with upregulation of β1 integrin and RhoA, highlighting a potentially important role for cytoskeleton reorganization. Taken together, these results provide functional evidence that LIPUS might be a useful tool to explore in the field of heart cell therapy

Suppression of breast cancer growth and metastasis by a serpin myoepithelium-derived serine proteinase inhibitor expressed in the mammary myoepithelial cells

A serpin was identified in normal mammary gland by differential cDNA sequencing. In situ hybridization has detected this serpin exclusively in the myoepithelial cells on the normal and noninvasive mammary epithelial side of the basement membrane and thus was named myoepithelium-derived serine proteinase inhibitor (MEPI). No MEPI expression was detected in the malignant breast carcinomas. MEPI encodes a 405-aa precursor, including an 18-residue secretion signal with a calculated molecular mass of 46 kDa. The predicted sequence of the new protein shares 33% sequence identity and 58% sequence similarity to plasminogen activator inhibitor (PAI)-1 and PAI-2. To determine whether MEPI can modulate the in vivo growth and progression of human breast cancers, we transfected a full-length MEPI cDNA into human breast cancer cells and studied the orthotopic growth of MEPI-transfected vs. control clones in the mammary fat pad of athymic nude mice. Overexpression of MEPI inhibited the invasion of the cells in the in vitro invasion assay. When injected orthotopically into nude mice, the primary tumor volumes, axillary lymph node metastasis, and lung metastasis were significantly inhibited in MEPI-transfected clones as compared with controls. The expression of MEPI in myoepithelial cells may prevent breast cancer malignant progression leading to metastasis.

Choroid plexus epithelial expression of MDR1 P glycoprotein and multidrug resistance-associated protein contribute to the blood–cerebrospinal-fluid drug-permeability barrier

The blood–brain barrier and a blood–cerebrospinal-fluid (CSF) barrier function together to isolate the brain from circulating drugs, toxins, and xenobiotics. The blood–CSF drug-permeability barrier is localized to the epithelium of the choroid plexus (CP). However, the molecular mechanisms regulating drug permeability across the CP epithelium are defined poorly. Herein, we describe a drug-permeability barrier in human and rodent CP mediated by epithelial-specific expression of the MDR1 (multidrug resistance) P glycoprotein (Pgp) and the multidrug resistance-associated protein (MRP). Noninvasive single-photon-emission computed tomography with 99mTc-sestamibi, a membrane-permeant radiopharmaceutical whose transport is mediated by both Pgp and MRP, shows a large blood-to-CSF concentration gradient across intact CP epithelium in humans in vivo. In rats, pharmacokinetic analysis with 99mTc-sestamibi determined the concentration gradient to be greater than 100-fold. In membrane fractions of isolated native CP from rat, mouse, and human, the 170-kDa Pgp and 190-kDa MRP are identified readily. Furthermore, the murine proteins are absent in CP isolated from their respective mdr1a/1b(−/−) and mrp(−/−) gene knockout littermates. As determined by immunohistochemical and drug-transport analysis of native CP and polarized epithelial cell cultures derived from neonatal rat CP, Pgp localizes subapically, conferring an apical-to-basal transepithelial permeation barrier to radiolabeled drugs. Conversely, MRP localizes basolaterally, conferring an opposing basal-to-apical drug-permeation barrier. Together, these transporters may coordinate secretion and reabsorption of natural product substrates and therapeutic drugs, including chemotherapeutic agents, antipsychotics, and HIV protease inhibitors, into and out of the central nervous system.

Microvascular and tissue oxygen gradients in the rat mesentery

One of the most important functions of the blood circulation is O2 delivery to the tissue. This process occurs primarily in microvessels that also regulate blood flow and are the site of many metabolic processes that require O2. We measured the intraluminal and perivascular pO2 in rat mesenteric arterioles in vivo by using noninvasive phosphorescence quenching microscopy. From these measurements, we calculated the rate at which O2 diffuses out of microvessels from the blood. The rate of O2 efflux and the O2 gradients found in the immediate vicinity of arterioles indicate the presence of a large O2 sink at the interface between blood and tissue, a region that includes smooth muscle and endothelium. Mass balance analyses show that the loss of O2 from the arterioles in this vascular bed primarily is caused by O2 consumption in the microvascular wall. The high metabolic rate of the vessel wall relative to parenchymal tissue in the rat mesentery suggests that in addition to serving as a conduit for the delivery of O2 the microvasculature has other functions that require a significant amount of O2.

Dynamic mapping at the laminar level of odor-elicited responses in rat olfactory bulb by functional MRI

We have applied functional MRI (fMRI) based on blood oxygenation level-dependent (BOLD) image-contrast to map odor-elicited olfactory responses at the laminar level in the rat olfactory bulb (OB) elicited by iso-amyl acetate (10−2 dilution of saturated vapor) with spatial and temporal resolutions of 220×220×1,000 μm and 36 s. The laminar structure of the OB was clearly depicted by high-resolution in vivo anatomical MRI with spatial resolution of 110×110×1,000 μm. In repeated BOLD fMRI measurements, highly significant (P < 0.001) foci were located in the outer layers of both OBs. The occurrence of focal OB activity within a domain at the level of individual glomeruli or groups of glomeruli was corroborated on an intra- and inter-animal basis under anesthetized conditions with this noninvasive method. The dynamic studies demonstrated that the odor-elicited BOLD activations were highly reproducible on a time scale of minutes, whereas over tens of minutes the activations sometimes varied slowly. We found large BOLD signal (ΔS/S = 10–30%) arising from the olfactory nerve layer, which is devoid of synapses and composed of unmyelinated fibers and glial cells. Our results support previous studies with other methods showing that odors elicit activity within glomerular layer domains in the mammalian OB, and extend the analysis to shorter time periods at the level of individual glomeruli or groups of glomeruli. With further improvement, BOLD fMRI should be ideal for systematic analysis of the functional significance of individual glomeruli in olfactory information encoding and of spatiotemporal processing within the olfactory system.

Disease sequence from mutant rhodopsin allele to rod and cone photoreceptor degeneration in man

Mutations in the gene encoding rhodopsin, the visual pigment in rod photoreceptors, lead to retinal degeneration in species from Drosophila to man. The pathogenic sequence from rod cell-specific mutation to degeneration of rods and cones remains unclear. To understand the disease process in man, we studied heterozygotes with 18 different rhodopsin gene mutations by using noninvasive tests of rod and cone function and retinal histopathology. Two classes of disease expression were found, and there was allele-specificity. Class A mutants lead to severely abnormal rod function across the retina early in life; topography of residual cone function parallels cone cell density. Class B mutants are compatible with normal rods in adult life in some retinal regions or throughout the retina, and there is a slow stereotypical disease sequence. Disease manifests as a loss of rod photoreceptor outer segments, not singly but in microscopic patches that coalesce into larger irregular areas of degeneration. Cone outer segment function remains normal until >75% of rod outer segments are lost. The topography of cone loss coincides with that of rod loss. Most class B mutants show an inferior-nasal to superior-temporal retinal gradient of disease vulnerability associated with visual cycle abnormalities. Class A mutant alleles behave as if cytotoxic; class B mutants can be relatively innocuous and epigenetic factors may play a major role in the retinal degeneration.

Muscle protein synthesis by positron-emission tomography with l-[methyl-11C]methionine in adult humans

Existing methods for assessing protein synthetic rates (PSRs) in human skeletal muscle are invasive and do not readily provide information about individual muscle groups. Recent studies in canine skeletal muscle yielded PSRs similar to results of simultaneous stable isotope measurements using l-[1-13C, methyl-2H3]methionine, suggesting that positron-emission tomography (PET) with l-[methyl-11C]methionine could be used along with blood sampling and a kinetic model to provide a less invasive, regional assessment of PSR. We have extended and refined this method in an investigation with healthy volunteers studied in the postabsorptive state. They received ≈25 mCi of l-[methyl-11C]methionine with serial PET imaging of the thighs and arterial blood sampling for a period of 90 min. Tissue and metabolite-corrected arterial blood time activity curves were fitted to a three-compartment model. PSR (nmol methionine⋅min−1⋅g muscle tissue−1) was calculated from the fitted parameter values and the plasma methionine concentrations, assuming equal rates of protein synthesis and degradation. Pooled mean PSR for the anterior and posterior sites was 0.50 ± 0.040. When converted to a fractional synthesis rate for mixed proteins in muscle, assuming a protein-bound methionine content of muscle tissue, the value of 0.125 ± 0.01%⋅h−1 compares well with estimates from direct tracer incorporation studies, which generally range from ≈0.05 to 0.09%⋅h−1. We conclude that PET can be used to estimate skeletal muscle PSR in healthy human subjects and that it holds promise for future in vivo, noninvasive studies of the influences of physiological factors, pharmacological manipulations, and disease states on this important component of muscle protein turnover and balance.

Signal changes in the spinal cord of the rat after injection of formalin into the hindpaw: Characterization using functional magnetic resonance imaging

Changes in metabolism and local circulation occur in the spinal cord during peripheral noxious stimulation. Evidence is presented that this stimulation also causes signal intensity alterations in functional magnetic resonance images of the spinal cord during formalin-induced pain. These results indicate the potential of functional magnetic resonance imaging in assessing noninvasively the extent and intensity of spinal cord excitation in this well characterized pain model. Therefore, the aim of this study was to establish functional magnetic resonance imaging as a noninvasive method to characterize temporal changes in the spinal cord after a single injection of 50 μl of formalin subcutaneously into the hindpaw of the anesthetized rat. This challenge produced a biphasic licking activity in the freely moving conscious animal. Images of the spinal cord were acquired within 2 min, enabling monitoring of the site and the temporal evolution of the signal changes during the development of formalin-induced hyperalgesia without the need of any surgical procedure. The time course of changes in the spinal cord functional image in the isoflurane-anesthetized animal was similar to that obtained from behavioral experiments. Also, comparable physiological data, control experiments, and the inhibition of a response through application of the local anesthetic agent lidocaine indicate that the signal changes observed after formalin injection were specifically related to excitability changes in the relevant segments of the lumbar spinal cord. This approach could be useful to characterize different models of pain and hyperalgesia and, more importantly, to evaluate effects of analgesic drugs.

Dynamic regulation of c-Jun N-terminal kinase activity in mouse brain by environmental stimuli

Activation of the recently identified c-Jun N-terminal kinases (JNKs) typically results in programmed cell death (apoptosis) in neurons and other cell types grown in culture. However, the effects of JNK activation in the central nervous system in vivo are unknown. At baseline, JNK activity in mice was on average 17-fold higher in brain than in peripheral organs, whereas JNK protein levels were similar. In brain, JNK was expressed primarily in neurons. Restraining mice or allowing them to explore a novel environment rapidly increased JNK activity 3- to 15-fold in various brain regions, but these manipulations did not increase brain activity of the extracellular signal-regulated kinase. Because noninvasive environmental stimuli that do not induce neurodegeneration elicited prominent increases in JNK activity in the brain, we conclude that acute activation of the JNK cascade in central nervous system neurons does not induce neuronal apoptosis in vivo. In contrast, the high baseline activity of JNK in the brain and the activation of the JNK cascade by environmental stimuli suggest that this kinase may play an important physiological role in neuronal function.