Clinical improvement after intraarticular and intraosseous injections of platelet rich plasma combined with hyaluronic acid for knee osteoarthritis. Case series.

INTRODUCTION: knee osteoarthritis (KOA) is known as the most common form of osteoarthrosis with a 6% prevalence in people over 30 years old, and more than 40% in the population over 70 years old. The use of PRP led to diverse results and this disparity can be attributed to the dissimilar methods of PRP preparation. This study aims to assess the functional effects of intraosseous (IO) and intraarticular (IA) injections of platelet rich plasma (PRP) followed by IA injections of hyaluronic acid (HA). OBJECTIVES: this study aimed to assess the functional effects of intraosseous (IO) and intraarticular (IA) injections of platelet rich plasma (PRP) followed by IA injections of hyaluronic acid (HA), administered 3 and 4 weeks after the initiation of treatment in 33 patients with grade II-III (Ahlback scale) knee osteoarthritis (KOA). MATERIAL AND METHODS: retrospectively, 33 patients were assessed using the Western Ontario and McMaster Universities (WOMAC) osteoarthritis index and visual analogue scale (VAS) score. They were followed-up for 12.92 months on average. Patients were divided into three groups based on age and four groups based on the follow-up period. RESULTS: the pre-operative mean of the WOMAC index was 44.35 ± 20.20 and the post-operative mean was 22.81 ± 17.25 (p < 0.001). The pre-operative and post-operative mean of the VAS scores were 5.79 ± 2.01 and 2.41 ± 1.43 (p < 0.001), respectively. The largest improvement in WOMAC (from 42.86 to 13.69) was observed in the youngest patients (44 to 55 years old) and the largest reduction in VAS (from 6.89 to 2.22) was seen in patients aged 56 to 70 years. CONCLUSION: the combination of IO and IA plasma rich in growth factor (PRGF) treatment with the IA-HA treatment yielded excellent results, diminishing pain and improving motor functionality in patients with KOA.

INTRODUCCIÓN: la artrosis de rodilla (OA) es conocida como la forma más común de osteoartrosis con una prevalencia de 6% en personas mayores de 30 años y más de 40% en la población mayor de 70 años. El uso de plasma rico en plaquetas (PRP) condujo a resultados diversos y esta disparidad puede atribuirse a los diferentes métodos de preparación del PRP. Este estudio tiene como objetivo evaluar los efectos funcionales de las inyecciones intraóseas (IO) e intraarticulares (IA) de plasma rico en plaquetas (PRP) seguidas de inyecciones IA de ácido hialurónico (AH). OBJETIVOS: este estudio tuvo como objetivo evaluar los efectos funcionales de las inyecciones intraóseas (IO) e intraarticulares (IA) de plasma rico en plaquetas (PRP) seguidas de inyecciones IA de ácido hialurónico (AH), administrada 3 y 4 semanas después del inicio del tratamiento en 33 pacientes con osteoartrosis de rodilla (OR) grado II-III (escala de Ahlbäck). MATERIAL Y MÉTODOS: retrospectivamente, se evaluó a 33 pacientes utilizando el índice de osteoartritis de las Universidades Western Ontario y McMaster (WOMAC) y la puntuación de la escala visual analógica (EVA). Se les realizó un seguimiento medio de 12.92 meses. Los pacientes se dividieron en tres grupos según la edad y cuatro grupos según el período de seguimiento. RESULTADOS: la media preoperatoria del índice WOMAC fue de 44.35 ± 20.20 y la media postoperatoria fue de 22.81 ± 17.25 (p < 0.001). La media preoperatoria y postoperatoria de las puntuaciones de la EVA fue de 5.79 ± 2.01 y 2.41 ± 1.43 (p < 0.001), respectivamente. La mayor mejoría en WOMAC (de 42.86 a 13.69) se observó en los pacientes más jóvenes (44 a 55 años) y la mayor reducción de la EVA (de 6.89 a 2.22) se observó en pacientes de 56 a 70 años. CONCLUSIÓN: la combinación del tratamiento de plasma rico en factores de crecimiento (PRGF) IO e IA con el tratamiento IA-AH produjo excelentes resultados, disminuyendo el dolor y mejorando la funcionalidad motora de los pacientes con OR.

Structural, dynamic, and hydration properties of quercetin and its aggregates in solution.

Quercetin is a flavonoid present in the human diet with multiple health benefits. Quercetin solutions are inhomogeneous even at very low concentrations due to quercetin's tendency to aggregate. We simulate, using molecular dynamics, three systems of quercetin solutions: infinite dilution, 0.22 M, and 0.46 M. The systems at the two highest concentrations represent regions of the quercetin aggregates, in which the concentration of this molecule is unusually high. We study the behavior of this molecule, its aggregates, and the modifications in the surrounding water. In the first three successive layers of quercetin hydration, the density of water and the hydrogen bonds formations between water molecules are smaller than that of bulk. Quercetin has a hydrophilic surface region that preferentially establishes donor hydrogen bonds with water molecules with relative frequencies from 0.12 to 0.46 at infinite dilution. Also, it has two hydrophobic regions above and below the planes of its rings, whose first hydration layers are further out from quercetin (≈0.3 Å) and their water molecules do not establish hydrogen bonds with it. Water density around the hydrophobic regions is smaller than that of the hydrophilic. Quercetin molecules aggregate inπ-stacking configurations, with a distance of ≈0.37 nm between the planes of their rings, and form bonds between their hydroxyl groups. The formation of quercetin aggregates decreases the hydrogen bonds between quercetin and the surrounding water and produces a subdiffusive behavior in water molecules. Quercetin has a subdiffusive behavior even at infinite dilution, which increases with the number of molecules within the aggregates and the time they remain within them.

PieloRM: una nueva herramienta en el estudio de pielonefritis aguda en pediatría / PyeloMR (PieloRM): a new tool in the study of acute pyelonephritis in children

Para determinar la existencia de compromiso parenquimatoso renal en infección del tracto urinario en niños, la tendencia actual es utilizar métodos de imágenes lo menos invasivos posibles, disminuyendo al máximo la exposición a radiación ionizante. La resonancia magnética ha demostrado utilidad en la pesquisa de pielonefritis aguda. Desarrollamos por esto un protocolo de resonancia magnética (PieloRM), que permite de manera rápida, segura y no invasiva detectar compromiso inflamatorio parenquimatoso renal, eventuales complicaciones y alteraciones anatómicas preexistentes. Se utilizan secuencias anatómicas potenciadas en T2 y difusión en los planos axial y coronal en el eje largo de los riñones, sin contraste endovenoso ni anestesia, con técnica de privación de sueño, abrigar y alimentar en lactantes y niños más pequeños. La duración total del examen no sobrepasa los 15 minutos.

Current trend to determine kidney involvement in urinary tract infection in children consider less invasive and lower radiation exposure. Magnetic resonance has been reported has a useful tool in acute pyelonephritis suspicion. We developed a fast, safety, non-contrast magnetic resonance protocol to detect renal parenchymal inflammatory changes in children. Complications and anatomical alterations were also possible to be evaluated. Axial and coronal T2-weighted images for anatomical characterization and diffusion weighted images were obtain for kidney representation. Feed and wrap technique and sleep deprivation, with non-additional sedation or anesthesia was used in a 15 minutes total examination protocol.

Lesión por estrés de la fisis distal del fémur: reporte de un caso y revisión del tema / Distal physis femur stress injury

En este reporte presentamos el caso de un niño de 14 años sin antecedentes mórbidos, que consulta por un cuadro de gonalgia, confirmándose el diagnóstico mediante resonancia magnética (RM) de lesión por estrés de la fisis distal del fémur. La literatura muestra que este tipo de lesiones son frecuentes en pacientes jóvenes deportistas y que el mecanismo que lleva al engrosamiento fisiario se produce por un trauma repetido que genera estrés mecánico y distracción del cartílago de crecimiento. El objetivo de esta publicación es aportar un caso a la literatura y dar a conocer la importancia de la radiología en el diagnóstico precoz de esta enfermedad, para que de esta forma el paciente no presente complicaciones futuras.

In this case report we present a 14-year-old patient with no previous medical history, who asked for knee pain. He was diagnosed with stress injury of the femur physis. The literature shows that this type of injuries are frequent in young athletes and the mechanism that leads to physeal widening is produced by a repeated trauma that generates mechanical stress and distraction of the growth cartilage. The aim of this case report is to show the relevance of radiology in the early diagnosis of this disease preventing future complications.

Antioxidant activity in plasma and rumen papillae development in lambs fed fermented apple pomace.

The effect of fermented apple pomace (FAP) on animal health, antioxidant activity (AA), hematic biometry (HBm) and the development of ruminal epithelium were investigated in a study with 24 finishing lambs (BW = 25.4 ± 3.3 Kg). Lambs were grouped by sex (12 male and 12 female) and fed (n = 6 per group of treatment) a basal fattening diet (Control diet, T1) or the basal diet supplemented to include 10.91% of fermented apple pomace (FAP diet, T2). The animals were kept 56 d in individual metabolic cages, with ad libitum access to water and feed. Two blood samples were collected from each animal on d 0, 28, and 56 to determine AA in plasma and hematic biometry (HBm). Four samples of ruminal tissue were taken postmortem to evaluate the development of ruminal epithelium based on the length (LP) and width (WP) of papillae. AA and HBm data were analyzed with a mixed model (fixed effects: diet, sampling, sex, and their interaction; using the experimental unit nested in the effect of the diet as the random effect). LP and WP were analyzed with a hierarchical model, as simple and nested effects in the sampling site, where the fixed effects were the diet and the sex of the animal and their interaction. There was an effect of diet on AA, which was higher (P < 0.06) in T2 vs. T1 at 56 d (24.34 vs. 21.79 mM Fe2). Leukocytes increased (P < 0.05) from 7.52*10(3) ± 1.29*10/(3)µL to 9.14*10(3) ± 1.24*10(3)/µL in all the animals in the experiment, with a marked increased (P < 0.05) at 28 d after beginning of the feeding period, with values within the normal range for this species and without effect of the diet (P > 0.05) for the other indicators of HBm. Males' LP was higher in T2 than in T1 (P < 0.05). It was concluded that the use of FAP in the diets of finishing sheep reaped benefits on animal health and the development of rumen epithelium by improving antioxidant activity in plasma and stimulating the growth of papillae.

Intra-articular administration of an antibody against CSF-1 receptor reduces pain-related behaviors and inflammation in CFA-induced knee arthritis.

Several studies have shown that blockade of colony stimulating factor-1 (CSF-1) or its receptor (CSF-1R) inhibits disease progression in rodent models of rheumatoid arthritis (RA); however, the role of the CSF-1/CSF-1R pathway in RA-induced pain and functional deficits has not been studied. Thus, we examined the effect of chronic intra-articular administration of a monoclonal anti-CSF-1R antibody (AFS98) on spontaneous pain, knee edema and functional disabilities in mice with arthritis. Unilateral arthritis was produced by multiple injections of complete Freund's adjuvant (CFA) into the right knee joint of adult male ICR mice. CFA-injected mice were then treated twice weekly from day 10 until day 25 with anti-CSF-1R antibody (3 and 10 µg/5 µL per joint), isotype control (rat IgG 10 µg/5 µL per joint) or PBS (5 µl/joint). Knee edema, spontaneous flinching, vertical rearing and horizontal exploratory activity were assessed at different days. Additionally, counts of peripheral leukocytes and body weight were measured to evaluate general health status. Intra-articular treatment with anti-CSF-1R antibody significantly increased horizontal exploratory activity and vertical rearing as well as reduced spontaneous flinching behavior and knee edema as compared to CFA-induced arthritis mice treated with PBS. Treatment with this antibody neither significantly affect mouse body weight nor the number of peripheral leukocytes. These results suggest that blockade of CSF-1R at the initial injury site (joint) could represent a therapeutic alternative for improving the functional disabilities and attenuating pain and inflammation in patients with RA.

Revisión de técnica y utilidades de la tomosíntesis digital de tórax en la actualidad / A review of current techniques and usefulness of digital chest tomosynthesis

Digital tomosynthesis (DTS) of the chest is an imaging technique composed of similar components to digital radiography (DR). Its advantages over DR: more precise diagnosis of the thoracic structure alterations, useful for confirming or ruling out suspected nodules, detection of patients at high risk of lung cancer and the monitoring of known lesions. The DTS creates coronal thoracic reconstructions with resolution superior to CT; however it is limited by its depth resolution and sensitivity to movement, occasionally hiding lesions adjacent to the pleura, diaphragm and mediastinum. The radiation dose of DTS and the cost is much lower than CT. More specific applications as well as the pulmonary nodules are under investigation, such as mycobacterial infection, cystic fibrosis and others. A basic understanding of the usefulness of thoracic DTS and its technique may be useful for the radiologist.

La Tomosíntesis digital (TSD) de tórax es una técnica de imagen compuesta por piezas similares que la radiografía digital (RD). Sus ventajas de sobre RD: diagnóstico más preciso de las alteraciones estructuras torácicas, útil para confirmar o descartar la sospecha de nódulos, detección de los pacientes de alto riesgo de cáncer pulmonar y seguimiento de lesiones conocidas. La TSD crea reconstrucciones coronales torácicas con resolución superior a TC. Sin embargo, está limitada por su resolución de profundidad y susceptibilidad al movimiento, ocultando ocasionalmente lesiones adyacentes a pleura, diafragma y mediastino. La dosis de radiación de TSD y el costo son más bajos que la TC. Más aplicaciones específicas además de los nódulos pulmonares están bajo investigación, como la infección por micobacterias, fibrosis quística y otras. Una comprensión básica de la utilidad de TSD torácica y su técnica puede ser útil para el radiólogo.

Manifestaciones abdominales de las anomalías del Situs Ambiguous en el adulto: a propósito de cuatro casos / Situs Ambiguous abnormalities in adults: a study of four cases

Las Anomalías del Situs (ASIT) han sido descritas principalmente en la población pediátrica y existe escasa información sobre éstas en el adulto. Son anomalías muy raras; en el caso del Situs Ambiguous (SAMB) en el adulto sólo se han publicado pocas series de casos. SAMB, también llamado heterotaxia o Síndrome de heterotaxia, es definido como la posición anormal o ambigua de los órganos y vasos, que además pueden asociarse a alteraciones morfológicas características de cada órgano. Existen dos grandes grupos dentro de los SAMB: Poliesplenia y Asplenia. En la presente publicación se expone una revisión bibliográfica específica, la cual tiene énfasis en clasificación de las ASIT del adulto y los hallazgos abdominales en los casos de SAMB. Será complementada clínica e imaginológicamente con cuatro casos de estudios tomográficos abdominales.

Anomalies Situs (ASIT) has been described mainly in the pediatric population and there is little information on this in adults. These are very rare abnormalities; in the case of Situs Ambiguous (SAMB) in adults, there have only been a few published case series. SAMB, also called heterotaxy or heterotaxy Syndrome, is defined as the abnormal or ambiguous positioning of organs and vessels, that could also be associated with morphological alterations characteristic of each organ. There are two main groups within SAMB: polysplenia and asplenia. This publication present a specific literature review, with emphasis on the classification of adult ASIT and abdominal findings in cases of SAMB. It will be complemented clinically and radiologically with four cases of abdominal tomographic imaging studies.

The investigation of congenital infection by Trypanosoma cruzi in an endemic area of Chile: three protocols explored in a pilot project.

Given the increasing travel of pregnant women from areas were Trypanosoma cruzi is endemic, the congenital transmission of the parasite has become a global public-health problem. In a recent pilot study, which ran in Chile from 2006 to 2010, three strategies for exploring and managing T. cruzi-infected mothers and their infected or uninfected neonates were investigated. Any protocols applied to the investigation of such mother-and-child pairs need to include the detection of infection in pregnant women, the detection of infection, if any, in the children born to the women, the appropriate treatment of the infected neonates, and the serological-parasitological follow-up of all of the neonates until their medical discharge.

The majority of myelinated and unmyelinated sensory nerve fibers that innervate bone express the tropomyosin receptor kinase A.

Although skeletal pain is a leading cause of chronic pain and disability, relatively little is known about the specific populations of nerve fibers that innervate the skeleton. Recent studies have reported that therapies blocking nerve growth factor (NGF) or its cognate receptor, tropomyosin receptor kinase A (TrkA) are efficacious in attenuating skeletal pain. A potential factor to consider when assessing the analgesic efficacy of targeting NGF-TrkA signaling in a pain state is the fraction of NGF-responsive TrkA+ nociceptors that innervate the tissue from which the pain is arising, as this innervation and the analgesic efficacy of targeting NGF-TrkA signaling may vary considerably from tissue to tissue. To explore this in the skeleton, tissue slices and whole mount preparations of the normal, adult mouse femur were analyzed using immunohistochemistry and confocal microscopy. Analysis of these preparations revealed that 80% of the unmyelinated/thinly myelinated sensory nerve fibers that express calcitonin gene-related peptide (CGRP) and innervate the periosteum, mineralized bone and bone marrow also express TrkA. Similarly, the majority of myelinated sensory nerve fibers that express neurofilament 200 kDa (NF200) which innervate the periosteum, mineralized bone and bone marrow also co-express TrkA. In the normal femur, the relative density of CGRP+, NF200+ and TrkA+ sensory nerve fibers per unit volume is: periosteum>bone marrow>mineralized bone>cartilage with the respective relative densities being 100:2:0.1:0. The observation that the majority of sensory nerve fibers innervating the skeleton express TrkA+, may in part explain why therapies that block NGF/TrkA pathway are highly efficacious in attenuating skeletal pain.

Neurosonografía y resonancia magnética en patología cerebral fetal severa / Ultrasound and magnetic resonance imaging in the prenatal evaluation of brain pathology

Abnormalities of the brain are among the most frequent congenital malformations and its incidence is probably higher than reported as many of the anomalies are only recognized postnatally. Fetal neurosonography performed transvaginally has become an important imaging technique based on its improved resolution and resulting better sensibility. Nevertheless, there are several maternal and fetal factors that can affect visualization rate and, therefore, it has been recommended that US should be complemented with 3D ultrasound and magnetic resonance imaging (MRI) in the prenatal evaluation of brain pathology. In the last years, the incorporation of ultrafast MRI has allowed to obtain high-quality images from the fetal lungs and brain. In this collaborative work from 2 public hospitals, we compare the diagnostic performance of fetal neurosonography and MRI in 17 cases of severe fetal brain abnormalities. MRI was able to confirm the diagnosis in 100 percent of the cases, adding important clinical information in 17 percent, although missed diagnoses were documented in 12 percent of them. These results are comparable to other published series, highlighting the diagnostic correlation between the 2 techniques. Nevertheless, ultrasound has the advantages of its wider availability and lower costs than MRI, which make it the prefered imaging modality when a fetal brain malformation is suspected.

Las malformaciones congénitas cerebrales son muy frecuentes y probablemente tengan una incidencia mayor aun a la descrita, pues muchas de ellas solo son reconocidas en la etapa postnatal. La neurosonografía fetal dirigida por vía transvaginal se ha incorporado los últimos años como el estándar de referencia en el diagnostico de estas malformaciones, especialmente por la mayor sensibilidad y una mejor resolución. Aun así, pueden existir condiciones maternas o fetales que obligan a complementar el estudio con otras tecnologías como el ultrasonido 3D y la resonancia magnética (RM). Con la incorporación de secuencias ultrarrápidas, la RM ha permitido obtener imágenes prenatales de calidad diagnostica donde destacan el estudio de malformaciones de tórax y del cerebro fetal. Este trabajo colaborativo de 2 centros públicos compara los resultados diagnósticos entre la neurosonografía y RM en 17 casos de patología neurológica fetal. La RM confirma el 100 por ciento de los diagnósticos, pero además entrega información adicional en un 17 por ciento pero omite información parcial en un 12 por ciento de los casos. Estos resultados son comparables a lo publicado en series extranjeras, destacando la alta correlación diagnostica entre los 2 métodos. Sin embargo, los beneficios que tiene el US en comparación con la RM, como la alta disponibilidad y el bajo costo, aconsejan su uso preferente en nuestro medio.

Electric dichroism transients of aqueous solutions of DNA.

In this work we develop a theory of reduced electric linear dichroism transients of DNA fragments in aqueous solution. The DNA fragments are modelled as rigid 'bent-rod molecules' (BRM) with the following physical parameters: electric charge, electric polarizability tensors and hydrodynamical ones, and the average transition probability tensor per molecule. In order to study the growth and decay of electric dichroism transients, the orientational distribution function of the molecules is needed. This function is obtained by solving the time-dependent Fokker-Planck equation in the presence of a low electric field E, using a perturbation method and the Fourier method with time-dependent coefficients. In our calculations the origin of the coordinate system is the mass centre of the BRM. With respect to this centre, the electric dipole moment of the molecule is zero. The developed theory adequately explains the experimental results. We show that the theoretical approach used in this work is equivalent to the one applied in the Brownian dynamics simulation work performed by Porschke and co-workers. We also analyse the effect of a possible electric dipole moment on the transients of the reduced electric linear dichroism in DNA bent fragments.

Role of peripheral and spinal 5-HT6 receptors according to the rat formalin test.

The present study assessed the possible pronociceptive role of peripheral and spinal 5-HT(6) receptors in the formalin test. For this, local peripheral administration of selective 5-HT(6) receptor antagonists N-[3,5-dichloro-2-(methoxy)phenyl]-4-(methoxy)-3-(1-piperazinyl)-benzenesulphonamide (SB-399885) (0.01-1 nmol/paw) and 4-iodo-N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]benzene-sulfonamide hydrochloride (SB-258585) (0.001-0.1 nmol/paw) significantly reduced formalin-induced flinching. Local peripheral serotonin (5-HT) (10-100 nmol/paw) or 5-chloro-2-methyl-3-(1,2,3,6-tetrahydro-4-pyridinyl)-1H-indole hydrochloride (EMD-386088) (0.01-0.1 nmol/paw; a selective 5-HT(6) receptor agonist) augmented 0.5% formalin-induced nociceptive behavior. The local pronociceptive effect of 5-HT (100 nmol/paw) or EMD-386088 (0.1 nmol/paw) was significantly reduced by SB-399885 or SB-258585 (0.1 nmol/paw). In contrast to peripheral administration, intrathecal injection of 5-HT(6) receptor antagonists SB-399885 and SB-258585 (0.1-10 nmol/rat) did not modify 1% formalin-induced nociceptive behavior. Spinal 5-HT (50-200 nmol/rat) significantly reduced formalin-induced flinching behavior during phases 1 and 2. Contrariwise, intrathecal EMD-386088 (0.1-10 nmol/rat) dose-dependently increased flinching during phase 2. The spinal pronociceptive effect of EMD-386088 (1 nmol/rat) was reduced by SB-399885 (1 nmol/rat) and SB-258585 (0.1 nmol/rat). Our results suggest that 5-HT(6) receptors play a pronociceptive role in peripheral as well as spinal sites in the rat formalin test. Thus, 5-HT(6) receptors could be a target to develop analgesic drugs.

Identification of the Na+/H+ exchanger 1 in dorsal root ganglion and spinal cord: its possible role in inflammatory nociception.

mRNA and protein presence of Na+/H+ exchanger (NHE) 1 (NHE1) and 5 (NHE5) in dorsal root ganglion (DRG) and dorsal spinal cord as well as its possible role in three inflammatory nociception tests were determined. Local peripheral ipsilateral, but not contralateral, administration of NHE inhibitors 5-(N,N-dimethyl)amiloride hydrochloride (DMA, 0.3-30 microM/paw), 5-(N-ethyl-N-isopropyl)amiloride (EIPA, 0.3-30 microM/paw) and amiloride (0.1-10 microM/paw) significantly increased flinching but not licking behavior in the capsaicin and 5-HT tests. Moreover, DMA and EIPA (0.03-30 microM/paw) as well as amiloride (0.1-1 microM/paw) augmented, in a dose-dependent manner, 0.5% formalin-induced flinching behavior during phase II but not during phase I. Reverse transcription-polymerase chain reaction showed the expression of NHE1 and NHE5 in DRG and dorsal spinal cord. Western blot analysis confirmed the presence of NHE1 in DRG and spinal cord. Moreover, NHE5 was expressed in dorsal spinal cord, but not in DRG where a 45 kDa truncated isoform of NHE5 was identified. Collectively, these data suggest that NHE1, but not NHE5, plays an important role reducing inflammatory pain in rats.

[Bilateral bronchoalveolar lavage: a clinical case, method and discussion]. / Lavado broncoalveolar bilateral secuencial: caso clínico, método y discusión.

Bronchoalveolar lavage is the most effective treatment of alveolar proteinosis. We describe a variant of the usual technique. In a clinical case, we performed bronchoalveolar lavage sequentially in both lungs, without needing to stop the technique after completing the lavage of the first lung, with significant clinical improvement of the patient (pulmonary compliance and saturation). Given the amount of protein-like material lavaged, it was more effective and better tolerated in prone decubitus position. This variant permitted a shorter hospital stay. It avoided new sedation and intubation. The patient could be extubated at a few hours with good clinical tolerance. Lavage of both lungs permitted discharge to ward in less than 24 hours. The result at middle term was similar to the conventional technique. Lavage could be performed again on several occasions with the same clinical tolerance.

A procedure for the efficient selection of piezoelectric ceramics constituting high-power ultrasonic transducers.

The most characteristic narrow-band transducer structure for high-power ultrasonic applications is the well known piezoelectric sandwich which is reminiscent of the Langevin transducer. Such structure is generally used jointly with other components in the construction of industrial high-power transducers. One of the main objectives in the design and construction of such high-power transducers is to minimize energy losses. To that purpose the selection of the piezoelectric ceramic rings forming the sandwich requires clear and specific criteria. This paper deals with a numerical and experimental procedure for the accurate selection of the piezoelectric rings constituting high-power transducers, based on the analysis of the mechanical Q, the frequency and the resonance curve. The procedure was experimentally checked by constructing and characterizing several transducer structures.

A power ultrasonic technology for deliquoring.

Solid-liquid separation is a topic of permanent interest in many areas such as mineral recovery, food processing and sewage disposal. The adequate application of high-intensity ultrasonic fields may contribute to improve the efficiency of conventional deliquoring processes. Deliquoring refers to removal of liquid from a product without changing its phase. Different effects are involved in the application of high-intensity ultrasound for deliquoring, the most important of which are: the alternating acoustic stresses, the radiation pressure, the acoustic streaming, interface instabilities and cavitation. One of the main advantages of the ultrasonic energy in deliquoring processes is its ability to release the strongly bound moisture. This paper deals with the application of an ultrasonic procedure for deliquoring of slurries in which a high-intensity vibration, homogeneously distributed, is directly applied to the wet particulate material. The vibration travels through the solid-liquid medium and the rapid series of alternative compressions and rarefactions produce a kind of "sponge effect" which favours the migration of moisture through natural or acoustically created channels. The obtained results show that the new technique is very promising to assist filtration processes for solid-liquid separation of highly concentrated suspensions of fine particles.

Recent developments in vibrating-plate macrosonic transducers.

As is known, the stepped-plate transducer [Ultrasonics 16 (6) (1978) 267] represents an optimum system for the efficient generation of high-intensity sonic and ultrasonic radiation in fluid media. Nevertheless, the design of this transducer may be difficult to adapt to some specific problems. Such is the case of the treatment of large volumes in industrial installations. A solution is the enlargement of the surface of the radiating plate. However, that means to work at high-order vibration modes which implies numerous practical problems. Another case is the application of the stepped-plate transducer for the generation at sonic frequencies where the height of the steps of the radiating plate, which has to be half a wavelength of the radiation, becomes too high and it makes the transducer construction impractical. To face these specific situations a series of new designs in transducer development have been recently carried out. This paper presents the characteristics of two new transducer devices, one for the treatment of large industrial volumes and the other for low-frequency sonic applications. Both devices are based on vibrating-plate radiators and represent a novel approach to practical existing problems.

A macrosonic system for industrial processing

The development of high-power applications of sonic and ultrasonic energy in industrial processing requires a great variety of practical systems with characteristics which are dependent on the effect to be exploited. Nevertheless, the majority of systems are basically constituted of a treatment chamber and one or several transducers coupled to it. Therefore, the feasibility of the application mainly depends on the efficiency of the transducer-chamber system. This paper deals with a macrosonic system which is essentially constituted of a high-power transducer with a double stepped-plate radiator coupled to a chamber of square section. The radiator, which has a rectangular shape, is placed on one face of the chamber in order to drive the inside fluid volume. The stepped profile of the radiator allows a piston-like radiation to be obtained. The radiation from the back face of the radiator is also applied to the chamber by using adequate reflectors. Transducer-chamber systems for sonic and ultrasonic frequencies have been developed with power capacities up to about 5 kW for the treatment of fluid volumes of several cubic meters. The characteristics of these systems are presented in this paper.