A comparison of dental ultrasonic technologies on subgingival calculus removal: a pilot study.

PURPOSE: This pilot study compared the clinical endpoints of the magnetostrictive and piezoelectric ultrasonic instruments on calculus removal. The null hypothesis stated that there is no statistically significant difference in calculus removal between the 2 instruments. METHODS: A quasi-experimental pre- and post-test design was used. Eighteen participants were included. The magnetostrictive and piezoelectric ultrasonic instruments were used in 2 assigned contra-lateral quadrants on each participant. A data collector, blind to treatment assignment, assessed the calculus on 6 predetermined tooth sites before and after ultrasonic instrumentation. Calculus size was evaluated using ordinal measurements on a 4 point scale (0, 1, 2, 3). Subjects were required to have size 2 or 3 calculus deposit on the 6 predetermined sites. One clinician instrumented the pre-assigned quadrants. A maximum time of 20 minutes of instrumentation was allowed with each technology. Immediately after instrumentation, the data collector then conducted the post-test calculus evaluation. RESULTS: The repeated analysis of variance (ANOVA) was used to analyze the pre- and post-test calculus data (p≤0.05). The null hypothesis was accepted indicating that there is no statistically significant difference in calculus removal when comparing technologies (p≤0.05). Therefore, under similar conditions, both technologies removed the same amount of calculus. CONCLUSION: This research design could be used as a foundation for continued research in this field. Future studies include implementing this study design with a larger sample size and/or modifying the study design to include multiple clinicians who are data collectors. Also, deposit removal with periodontal maintenance patients could be explored.

A study of the efficacy of ultrasonic waves in removing biofilms.

OBJECTIVE: The removal of adherent biofilms was assessed using ultrasonic waves in a non-contact mode. MATERIALS AND METHODS: In in vitro experiments, Streptococcus mutans (S. mutans) biofilms were exposed to ultrasonic waves at various frequencies (280 kHz, 1 MHz, or 2 MHz), duty ratios (0-90%), and exposure times (1-3 minutes), and the optimal conditions for biofilm removal were identified. Furthermore, the effect of adding a contrast medium, such as micro bubbles (Sonazoid), was examined. The spatial distribution and architecture of S. mutans biofilms before and after ultrasonic wave exposure were examined via scanning electron microscopy. The biofilm removal effect was also examined in in vivo experiments, using a custom-made oral cleaning device. RESULTS: When a 280 kHz probe was used, the biofilm-removing effect increased significantly compared to 1 and 2 MHz probes; more than 80% of the adherent biofilm was removed with a duty cycle of 50-90% and a 3 minutes exposure time. The maximum biofilm-removing effect was observed with a duty cycle of 80%. Furthermore, the addition of micro bubbles enhanced this biofilm-removing effect. In in vivo experiments, moderate biofilm removal was observed when a 280 kHz probe was used for 5 minutes. CONCLUSIONS: This study demonstrated that ultrasonic wave exposure in a non-contact mode effectively removed adherent biofilms composed of S. mutans in vitro.

The effect of ultrasound on angiogenesis: an in vivo study using the chick chorioallantoic membrane.

PURPOSE: Ultrasound therapy induces clinical healing of irradiated avascular mandibular bone and fractures. In vitro ultrasound in tissue culture has been shown to stimulate bone formation synthesis and bone remodeling factors and to stimulate osteoblast proliferation. Therefore, the aim of the present study was to investigate the effect of short-wave (1-MHz) and long-wave (45-kHz) ultrasound on the vascularity of the chorioallantoic membrane (CAM) of a fertilized egg. MATERIALS AND METHODS: The nature of the angiogenic effect was investigated using the CAM of a fertilized egg by: (1) application of sonicated fibroblast media incorporated into methylcellulose disks onto the CAM and (2) direct application of the ultrasound, using both long-wave (45-kHz) and short-wave (1-MHz) frequencies at a range of intensities, to the surface of the egg. Angiogenesis was assessed quantitatively by three independent observers. RESULTS: Both ultrasound methods showed evidence of an angiogenic effect compared to controls. The most effective results were seen with direct application of a 45-kHz wave at an intensity of 15 mW/cm(2) and indirect application of the media of fibroblasts ultrasonicated at 1 MHz with an intensity of 0.4 W/cm(2). CONCLUSION: This model confirms that ultrasound can induce neoangiogenesis in vivo.

Echinococcus granulosus: protoscolicidal effect of high intensity focused ultrasound.

High intensity focused ultrasound (HIFU) is a new non-invasive technique which can cause cell death and tissue necrosis by focusing high-energy ultrasonic waves on a single location. The aim of our work is to investigate the damaging effect of HIFU on Echinococcus granulosus protoscolices, as well as its inhibitory effect on growth of hydatid cysts derived from protoscolices. The damaging effect of HIFU on protoscolices was investigated by following parasite mortality after irradiation, while the inhibitory effect was investigated by infection experiments in vivo. The results demonstrated that HIFU was able to damage protoscolices and the protoscolicidal effect was dose-dependent and showed late-onset. The growth of protoscolices that survived the exposure to HIFU was obviously suppressed in vitro, and the mean weight of hydatid cysts resulting from such protoscolices in the experimental group was less than that in controls. Evidences including the protoscolicidal effect, fragmentized protoscolices and low post exposure temperatures, suggest that cavitation may contribute to the protoscolicidal effect of HIFU. In addition, the structure of the germinal membrane in cysts developing from the irradiated protoscolices was not as normal or intact as that from non-irradiated ones, and morphological changes related to degeneration were observed, suggesting that HIFU could prevent protoscolices from developing normal germinal membrane and consequently stop the proliferation of secondary hydatid cysts. HIFU demonstrated damaging effect on protoscolices, inhibited the growth of protoscolices in vitro and in vivo, and could be a possible therapeutic option for cystic echinococcosis.

Planejamento, síntese e avaliação biológica de derivados pirrólicos com potencial atividade antiinflamatória / Design, synthesis and evaluation of biological derivatives pyrroles potentially antiinflamatory activity

Os antiinflamatórios não-esteróides (AINEs) estão entre os fármacos mais prescritos e utilizados do mundo. Estes fármacos inibem as ciclooxigenases, enzimas responsáveis pela transformação do ácido araquidônico em prostaglandinas flogísticas, pela ação da fosfolipase A2. A síntese de compostos antiinflamatórios contendo núcleo pirrólico em suas estruturas vem sendo um tópico muito atrativo e bastante estudado, que somado ao conhecimento do sítio de interação do fármaco ao receptor possibilita o planejamento de estruturas de novas substâncias candidatas a protótipos de novos fármacos, por meio da modificação molecular. Nesse contexto, o presente trabalho teve como objetivo o planejamento, síntese e avaliação biológica de derivados pirrólicos com potencial atividade antiinflamatória, com base nas estruturas da indometacina, protótipo da classe dos derivados de ácido arilalcanóico e dos diarilheterociclos (COXIBES). Sendo assim, foram obtidos cinco compostos em rendimentos satisfatórios, a partir de acetoacetato de etila, via metodologia de Hantzsch e ciclofuncionalização, utilizando ultrassom, que resultou na redução do tempo de reação e do consumo de solvente, seguindo os princípios da Química Verde. Os compostos 5a e 5b mostraram-se promissores, a partir de ensaios "in vitro"

The nonsteroidal antiinflammatory drugs (NSAIDs) are among the most prescribed and used drugs in the world. These drugs inhibit the cyclooxygenases, enzymes responsible for conversion of arachidonic acid into phlogistic prostaglandins, by the action of phospholipase A2. The synthesis of compounds containing pyrrole nucleus in their structures has been a topic very attractive and well studied, that knowledge added to the site of interaction of the drug to the receptor enables the planning of new structures of substances candidates for prototypes of new drugs through of molecular modification. In this context, this work aimed at the design, synthesis and biological evaluation of pyrrole derivatives with potential antiinflammatory activity, based on the structures of indomethacin, the prototype of arylalkanoic acid class and diarylheterocycles (coxibs). Thus, five compounds were obtained in good yields from ethyl acetoacetate, route of Hantzsch and cyclofunctionalization methods, using ultrasound, which resulted in the reduction of the reaction time and consumption of solvent, following the principles of Green Chemistry. The 5a and 5b compounds were shown to be promising, from tests in vitro

Neurobiology of 50-kHz ultrasonic vocalizations in rats: electrode mapping, lesion, and pharmacology studies.

Fifty-kHz ultrasonic vocalizations have been proposed to reflect a positive appetitive affective state in rats, being consistently linked to the positive appetitive behavior. In the first study, we examined the brain substrates of 50-kHz ultrasonic vocalizations (USVs) by using localized electrical stimulation of the brain (ESB) at various sites that are known to mediate reward. We found that the brain areas that produced ESB-induced 50-kHz calls are the areas that have previously been shown to support the most vigorous self-stimulation behavior (prefrontal cortex, nucleus accumbens, ventral pallidum, lateral preoptic area, lateral hypothalamus, ventral tegmental area, and raphe). Importantly, all animals that showed repeatable ESB-induced 50-kHz USVs demonstrated self-stimulation behavior. In the second study, conditioned place preference was assessed following microinjection of the mu-opiate agonist Tyr-D-Ala-Gly-N-methyl-Phe-Gly-ol (DAMGO) directly into the ventral tegmental area (VTA) at a dose previously found to be rewarding. Animals that showed more 50-kHz USVs in response to drug injections compared to vehicle injections showed significant place preferences, whereas animals that did not show elevated vocalization to DAMGO did not show place preference. In experiment 3, we examined the effect of VTA electrolytic lesions, 6-OHDA lesions, and the effect of the D1/D2 dopamine antagonist flupenthixol (0 and 0.8 mg/kg, i.p.) on 50-kHz ultrasonic vocalizations. We found that these manipulations all selectively reduced 50-kHz ultrasonic vocalizations, and that these effects could be disassociated from any side effects. These data are consistent with the proposition that 50-kHz calls are tightly linked to reward in rats and that the neural circuit of 50-kHz calls closely overlaps that of ESB self-stimulation reward, drug reward, and the mesolimbic dopamine system.

Substance P injected into the dorsal periaqueductal gray causes anxiogenic effects similar to the long-term isolation as assessed by ultrasound vocalizations measurements.

Housing conditions change the emotional state of the animals. Ultrasound vocalizations (USVs) termed as 22 kHz are the usual components of the defensive responses of rats exposed to threatening conditions such as isolation. The amount of emission of 22 kHz USVs depends on the intensity of the aversive stimuli. While short periods of isolation caused an anxiolytic-sensitive enhancement of the defensive responses, long-term isolation tended to reduce the defensive performance of the animals to aversive stimuli. The dorsal periaqueductal gray (dPAG) is an important vocal center and a crucial structure for the expression of defensive response. While it has been shown that Substance P (SP) at this midbrain level is involved in the modulation of the defensive response, its role in the emission of ultrasound vocalizations has not been evaluated. In this study we examined whether the resocialization and local injections of SP into the dPAG have an influence on the isolation-induced 22 kHz USVs recorded within the frequency range of 18-26 kHz. Rats isolated for 1 day showed a significant increase in the number and duration of USVs, which were reversed by resocialization. On the other hand, 2-week isolation reduced the number and duration of 22 kHz USVs, which could not be reversed by resocialization. SP injections into the dPAG (35 pmol/0.2 microL) caused a reduction in the 22 kHz USVs. Pretreatment with the NK-1 receptor antagonist spantide (100 pmol/0.2 microL) blocked these effects but exhibited no effect when given alone. These findings suggest that 1-day and 2-week isolation recruit distinct brain defensive systems. Also, in agreement with the notion that intense fear is associated with the neural substrates of fear of the dPAG, activation of NK-1 receptors of this midbrain structure reduces the 22 kHz USVs.

Tratamiento de afecciones músculo-esqueléticas con ondas de choque extracorpóreas / Extracorporeal shock wave therapy for musculoskeletal disorders

Extracorporeal shock waves are pressure waves used to treat certain musculoskeletal conditions. Focused wavetherapy, the same that is used in lithotripsy, but actingthrough a different mechanism, is used to treat pseudoarthritis and delayed consolidation, avascular necrosis of large joints, osteochondritis dissecans, calcific tendonitis and enthesopathies. We study its use in myocardial infarction. Results are positive, and this constitutes a non invasive alternative to surgery. It must be applied with anesthesia or analgesics and presents the same risks as lithotripsy. Radial wave therapy has shown good results in pathologies that do not respond well to conventional treatments, such as calcific tendonitis of the shoulder, frozen shoulder, plantar fasciitis (with or without calcaneal spurs), epicondilitis, trocanterous bursitis, patellar tendonitis,Achilles tendonitis, Morton’s neuroma, trigger points; and less favorable results in medial epicondylitis, andmore recently in diabetic foot. This therapy constitutes a non invasive alternative to surgery, practically riskfree. It is ambulatory and requires neither anesthesianor significant analgesics. It does not require sick leave. Shock waves act through the so called biological effect, producing analgesia and inducing osteogenesis, repairing tendons and other soft tissue damage, as well as reabsorbing calcium deposits. Results using shock waves are comparable to surgery, without the risks of complications associated to the later, with lower costs and less days of physical invalidity.

Smart wheelchairs: A literature review.

Several studies have shown that both children and adults benefit substantially from access to a means of independent mobility. While the needs of many individuals with disabilities can be satisfied with traditional manual or powered wheelchairs, a segment of the disabled community finds it difficult or impossible to use wheelchairs independently. To accommodate this population, researchers have used technologies originally developed for mobile robots to create "smart wheelchairs." Smart wheelchairs have been the subject of research since the early 1980s and have been developed on four continents. This article presents a summary of the current state of the art and directions for future research.

The use of pulsed ultrasound technology to improve environmental remediation: a comparative study.

Relatively little is known about the effects of pulsed ultrasound on the facilitation of chemical reactivity and remediation. Previous studies have indicated that sonochemistry using pulses may be either more or less effective than continuous wave (CW) ultrasonic irradiation. However, because of the time-modulated nature of the pulses used in these studies, less acoustic energy in general was transmitted to the solutions compared to CW sonication. The effectiveness of ultrasound when the pulse is adjusted so that the same amount of acoustic energy is input compared to continuous irradiation over a given time has not been previously explored. In this study we have embarked on a comparison of the efficacy of power-modulated pulsed (PMP) sonochemistry with more traditional time-modulated pulsing. As a prototypical reaction, we have explored the effects of pulse type on the degradation of acid orange, a common industrial colorant. An increase in the degradation rate by a factor of three was observed using PMP ultrasound compared with continuous irradiation under conditions of equivalent acoustic input power, while the use of time-modulated pulsed ultrasound from a commercially available direct-immersion (DI) horn-type sonicator exhibited a rate decrease compared to CW sonication. Possible mechanisms for the enhancement are discussed.

Theoretical study in applications of doublet mechanics to detect tissue pathological changes in elastic properties using high frequency ultrasound.

The mathematical framework of a new elastic theory-doublet mechanics (DM)-was reviewed. The fundamental difference between DM and classical continuum mechanics (CCM) is that the former has taken the discrete nature of tissue on the cellular level into account and the latter assumes tissue is uniform and continuous. Theoretical calculations based on DM were performed for reflection coefficients of a substrate-tissue layer-substrate assembly. Results of computer simulations have shown that ultrasound reflection coefficients in the range of 15-30 MHz are sensitive to changes in cell size and elastic moduli of tissue according to DM but not to CCM. Potential experimental applications of this technique to tissue characterization are discussed.

Determination of the acoustic output of a harmonic scalpel.

The acoustic output of a harmonic scalpel was experimentally determined, and both the airborne ultrasound and the ultrasound transmitted in water were taken into account. The sound pressure level of airborne ultrasound was measured with a microphone and an artificial head, so that the free-field value and the sound level at the entrance at the bottom of the cavum conchae of the ear could be determined. The derived output power in water was obtained from a hydrophone measurement. The results were strongly influenced by cavitation effects, and it is shown that the power values with and without cavitation differ by more than a factor of 5. The measurement of acoustic output parameters forms the basis for describing the performance of the devices and for an assessment of the risk of harmful bioeffects on both the operator and the patient.

Low-intensity pulsed ultrasound accelerates bone maturation in distraction osteogenesis in rabbits.

We investigated the effects of low-intensity pulsed ultrasound on distraction osteogenesis in a rabbit model. Callotasis of the right tibia was performed in 70 male Japanese white rabbits using mini-external fixators. In the first part of the study in 64 animals using normal distraction (waiting period seven days; distraction rate 0.5 mm/12 hours; distraction period ten days), we evaluated the distraction site by radiography, measurement of the bone mineral density (BMD), mechanical testing, and histology. In the second part in six rabbits using fast distraction (waiting period 0 days; distraction rate 1.5 mm/12 hours; distraction period seven days) the site was evaluated radiologically. Half of the animals (35) had received ultrasound to their right leg (30 mW/cm2) for 20 minutes daily after ceasing distraction (ultrasound group), while rigid fixation only was maintained in the other half (control group). With normal distraction, the hard callus area, as shown by radiography, the BMD, and the findings on mechanical testing, were significantly greater in those receiving ultrasound than in the control group. Histological analysis showed no tissue damage attributable to exposure to ultrasound. With fast distraction, immature bone regeneration was observed radiologically in the control group, while bone maturation was achieved in the ultrasound group. We conclude that ultrasound can accelerate bone maturation in distraction osteogenesis in rabbits, even in states of poor callotasis.

Low-megahertz ultrasonic properties of bovine cancellous bone.

Ultrasound offers a noninvasive means to detect changes that occur to the density of cancellous bone as a result of degenerative diseases such as osteoporosis. Techniques based on the velocity and frequency dependence of attenuation of ultrasonic pulses propagated through cancellous bone have proven sensitive to bone density. Most previous studies have investigated these two parameters in the frequency range of 0.1-1.0 MHz. The present study had two goals. The first was to measure three ultrasonic parameters: longitudinal mode velocity; broadband ultrasonic attenuation (BUA); and apparent integrated backscatter (AIB), at higher frequencies using a broadband 2.25 MHz measurement system. The second goal was to assess the dependence of these parameters on bone density. Twenty-one specimens of cancellous bone acquired from the proximal end of four bovine tibiae were investigated in this study. The apparent density of the specimens (determined with the bone marrow removed and the specimens thoroughly dry) ranged between 0.3 and 0.9 g/cm(3). Ultrasonic measurements were performed along three mutually perpendicular directions corresponding to the anteroposterior (AP), mediolateral (ML), and superoinferior (SI) axes of the tibia. A linear regression was used to analyze the results of these measurements as a function of apparent density. Velocity demonstrated a highly significant linear increase with density for all three directions (AP: p < 0.001; ML: p < 0.001; SI: p < 0.01). AIB decreased with density in all three directions; however, only the ML and SI directions demonstrated a significant linear correlation (AP: p = n.s.; ML: p < 0.05; SI: p < 0.05). In the frequency range 0.5-1.0 MHz, BUA exhibited a significant linear increase in the AP and ML directions, but not the SI direction (AP: p < 0.05; ML: p < 0.01; SI: p = n.s.). In contrast, in the frequency range 1.0-2.0 MHz, BUA exhibited a highly significant increase with density in the SI direction, but no significant change in the AP and ML directions (AP: p = n.s., ML: p = n.s., SI: p < 0.001).

Sonographic evaluation of renal failure.

Sonography is a critical component of the evaluation of both acute and chronic renal failure; however, most nephrologists have a limited knowledge of this procedure. The acoustic properties, limited spectrum of pathological changes, and ease of visualization of the kidneys, coupled with the safety, simplicity, and low cost of sonography, make it the modality of choice for renal imaging. This review discusses the basics of sonography as they apply to the kidney and describes the findings encountered in the more common causes of renal failure. Although many sonographic findings are nonspecific, their diagnostic use is greatly enhanced by a familiarity with the clinical presentation and a thorough understanding of renal pathophysiological characteristics. Therefore, nephrologists should be knowledgeable about renal sonography and participate in its interpretation.

Utilidad diagnóstica del ultrasonido en urgencias obstetricas Hospital de la Mujer Bertha Calderón Roque

Se realizo un estudio descriptivo, retrospectivo prolectivo y transversal, con el fin de estimar la utilidad del ultrasonido obstetrico en el diagnóstico de patologías abstetricas de urgencias a pacientes que acudieron al servicio de ultrasonografía desde la consulta externa y emergencia, en el período de octubre-diciembre 1999 a un total de 71 pacientes. Obteniendose que la mayor cantidad de pacientes corresponden a la mujer catalogada como en edad fértil, las características sociales de las pacientes estudiadas predomino las pacientes que han logrado alfabetizarse y con predominio del estado civil acompañada. Predominó la gestación avanzada, placentas maduras (grado III) con un líquido amniótico de características normales, se pudo observar que en este centro de referencia nacional, el diagnóstico clínico y el diagnóstico ultrasonográfico se corresponde en un 80.28 porciento de los casos y en el 29.57 porciento el diagnóstico ultrasonográfico es una urgencia obstetrica y corroborado con los hallazgos al finalizar el mismo, este porcentaje corresponde con la certeza clínica de una patología de urgencia obstetrica

Agentes ultra-sonográficos / Ultrassound contrast agents

Esta revisäo analisa o potencial e as limitaçöes dos agentes utra-sonográficos na ecocardiografia, na ultra-sonografia abdominal e nas anormalidades vasculares periféricas. Uma nova perspectiva para melhorar a imagem colorida na área da ecocardiografia e na circulaçäo periférica abriu-se pela introduçäo dos agentes ultra-sonográficos transpulmonares. Os contrastes ultra-sonográficos, pela intensificaçäo da taxa de sinal ruído, aumentam o potencial da imagem colorida na visibilizaçäo do fluxo de baixa intensidade ou do fluxo de vasos profundos. O objetivo deste trabalho é elevar o nível de conhecimento relativo aos agentes ultra-sonográficos e, assim, promover seu uso apropriado

Advances in ophthalmic ultrasound.

New ultrasound technologies, including three-dimensional imaging, tissue characterization, and very high frequency (50 MHz) ultrasound, have become available recently. We demonstrate how these technologies can be used alone and together to improve the use of ultrasound for diagnosis of ocular pathology.

Laparoscopia en la estadificación del cancer gastrico / Laparoscopy in gastric cancer starging

Con el fin de evaluar el papel de la laparoscopia en la estadificación del cáncer gástrico avanzado, se estudiaron 56 pacientes con diagnóstico endoscópico, radiológico e histológico de Adenocarcinoma gástrico. Se les realizó ultrasonido abdominal a todos los pacientes; en 21 pacientes se demostró extensión de la enfermedad y fueron excluidos de la laparoscopia y conducidos a tratamiento paliativo (endoscópico o quirúrgico). A los 35 pacientes con ultrasonido normal se les realizó laparoscopia, evidenciandose en 14 (40 por ciento) infiltración o metástasis. A los 21 pacientes (37 por ciento) sin evidencia de lesión a distancia se les realizó tratamiento quirúrgico con fines curativos

Colestasis grave asociada a hipertiroidismo / Severe cholestasis associated to hypertiroidism

Se informa el caso de una mujer de 29 años de edad con enfermedad de Graves-Basedow, que se relacionó con colestasis centrolobulillar no atribuida a la insuficiencia cardiaca ni a la exposición a hepatotóxicos. Las bilirrubinas séricas totales alcanzaron cifras de 52 mg/dL, 889.2 µmol/L. Con el tratamiento de hipertiroidismo se corrigió la colestasis