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Sample records for low-intensity pulsed ultrasound

  1. Low-intensity pulsed ultrasound in dentofacial tissue engineering.

    PubMed

    Tanaka, Eiji; Kuroda, Shingo; Horiuchi, Shinya; Tabata, Akira; El-Bialy, Tarek

    2015-04-01

    Oral and maxillofacial diseases affect millions of people worldwide and hence tissue engineering can be considered an interesting and clinically relevant approach to regenerate orofacial tissues after being affected by different diseases. Among several innovations for tissue regeneration, low-intensity pulsed ultrasound (LIPUS) has been used extensively in medicine as a therapeutic, operative, and diagnostic tool. LIPUS is accepted to promote bone fracture repair and regeneration. Furthermore, the effect of LIPUS on soft tissues regeneration has been paid much attention, and many studies have performed to evaluate the potential use of LIPUS to tissue engineering soft tissues. The present article provides an overview about the status of LIPUS stimulation as a tool to be used to enhance regeneration/tissue engineering. This review consists of five parts. Part 1 is a brief introduction of the acoustic description of LIPUS and mechanical action. In Part 2, biological problems in dentofacial tissue engineering are proposed. Part 3 explores biologic mechanisms of LIPUS to cells and tissues in living body. In Part 4, the effectiveness of LIPUS on cell metabolism and tissue regeneration in dentistry are summarized. Finally, Part 5 relates the possibility of clinical application of LIPUS in orthodontics. The present review brings out better understanding of the bioeffect of LIPUS therapy on orofacial tissues which is essential to the successful integration of management remedies for tissue regeneration/engineering. To develop an evidence-based approach to clinical management and treatment of orofacial degenerative diseases using LIPUS, we would like to be in full pursuit of LIPUS biotherapy. Still, there are many challenges for this relatively new strategy, but the up to date achievements using it promises to go far beyond the present possibilities.

  2. Low-Intensity Pulsed Ultrasound Treatment for Scaphoid Fracture Nonunions in Adolescents

    PubMed Central

    Carlson, Erik J.; Save, Ameya V.; Slade, Joseph F.; Dodds, Seth D.

    2015-01-01

    Background Treatment of scaphoid nonunion is challenging, leading clinicians to pursue innovation in surgical technique and adjunctive therapies to improve union rates. Purpose The purpose of this study was to investigate the use of low-intensity pulsed ultrasound as an adjunctive treatment modality following surgical treatment of scaphoid nonunion in adolescent patients, for whom this therapy has not yet been FDA-approved. Patients and Methods We performed a retrospective review of adolescent patients with scaphoid nonunion treated surgically followed by adjunctive low-intensity pulsed ultrasound therapy. All patients underwent 20 minutes of daily ultrasound therapy postoperatively until there was evidence of bony healing, based on both clinical and radiographic criteria. Final healing was confirmed by > 50% bone bridging on CT scan. Results Thirteen of fourteen (93%) patients healed at a mean interval of 113 days (range 61–217 days). There were no surgical or postoperative complications. One patient developed heterotopic bone formation about the scaphoid. Conclusions Our study suggests that low-intensity pulsed ultrasound therapy can safely be utilized as an adjunctive modality in adolescents to augment scaphoid healing following surgical intervention. Level of Evidence Level IV, Case series PMID:25945296

  3. Clinical applications of low-intensity pulsed ultrasound and its potential role in urology

    PubMed Central

    Lin, Guiting; Lei, Hongen; Lue, Tom F.; Guo, Yinglu

    2016-01-01

    Low-intensity pulsed ultrasound (LIPUS) is a form of ultrasound that delivered at a much lower intensity (<3 W/cm2) than traditional ultrasound energy and output in the mode of pulse wave, and it is typically used for therapeutic purpose in rehabilitation medicine. LIPUS has minimal thermal effects due to its low intensity and pulsed output mode, and its non-thermal effects which is normally claimed to induce therapeutic changes in tissues attract most researchers’ attentions. LIPUS have been demonstrated to have a rage of biological effects on tissues, including promoting bone-fracture healing, accelerating soft-tissue regeneration, inhibiting inflammatory responses and so on. Recent studies showed that biological effects of LIPUS in healing morbid body tissues may be mainly associated with the upregulation of cell proliferation through activation of integrin receptors and Rho/ROCK/Src/ERK signaling pathway, and with promoting multilineage differentiation of mesenchyme stem/progenitor cell lines through ROCK-Cot/Tpl2-MEK-ERK signaling pathway. Hopefully, LIPUS may become an effective clinical procedure for the treatment of urological diseases, such as chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), erectile dysfunction (ED), and stress urinary incontinence (SUI) in the field of urology. It still needs an intense effort for basic-science and clinical investigators to explore the biomedical applications of ultrasound. PMID:27141455

  4. Distinct anabolic response of osteoblast to low-intensity pulsed ultrasound.

    PubMed

    Naruse, Kouji; Miyauchi, Akimitsu; Itoman, Moritoshi; Mikuni-Takagaki, Yuko

    2003-02-01

    Low-intensity pulsed ultrasound, a form of mechanical energy transmitted as high-frequency acoustical pressure waves, provides noninvasive therapeutic treatment for accelerating fracture repair and distraction osteogenesis. Relatively young osteoblasts respond to ultrasound by transiently upregulating message levels of immediate-early genes as well as that of osteocalcin and insulin-like growth factor I (IGF-I). Osteocytes derived from newborn rat tibia and calvaria responded to a lesser extent only in c-fos and cyclooxygenase-2 (COX-2) messages. Compared with the stretched osteocytes, which use stretch-activated and parathyroid hormone (PTH)-potentiated Ca2+ influx as an entry route to the protein kinase A (PKA) signal transduction pathways, there was no evidence of Ca2+ internalization by any of the cells tested on exposure to the ultrasound. On the other hand, inhibitors of p38 mitogen-activated protein kinase (MAPK) and upstream phosphoinositide 3-kinase (PI3K) blocked COX-2 and osteocalcin upregulation by the ultrasound-exposed ST2, murine bone marrow-derived cells. This is distinct from the aforementioned osteocytic response to low-frequency stretching and implies the involvement of integrins. Our findings suggested that accelerated fracture repair and distraction osteogenesis by the low-intensity pulsed ultrasound depend, at least in part, on the stimulation of osteoblastic cells at relatively early stages of osteogenic lineage. Bone is under control of multiple regulatory mechanisms so that diverse physical forces can be reflected to the microenvironment of each cell, in turn, to the entire bone.

  5. Histologic evaluation of low-intensity pulsed ultrasound effects on bone regeneration in sinus lift.

    PubMed

    Kim, Sang Hun; Hong, Ki Seok

    2010-12-01

    Many techniques have been described for achieving vertical augmentation of the maxillary sinus. The aim of this study is to evaluate the effect of low-intensity pulsed ultrasound (LIPUS) to enhance bone regeneration after sinus floor elevation. The sinus lifting technique was performed through a lateral approach on 8 different sites of 5 patients (3 males and 2 females) and their mean age was 45.7 years old. The sites were randomly assigned to the control or test groups. The control group had 4 sites that received lateral sinus lifting procedure only, while the test group had 4 sites that received LIPUS application after the lateral sinus lifting procedure. 24-32 weeks (an average of 29 weeks) postoperatively, new bone formation in the augmented sinus sites was evaluated through histologic and histomorphometric analyses of the biopsy specimens obtained during implant placement. In the test group, the mean percentage of newly formed bone was 19.0±2.8%. In the control group, the mean percentage of newly formed bone was 15.2±3.1%. The percentage of newly formed bone was approximately 4% higher in those cases where the sinus was treated by LIPUS than the percentage in those cases where it was not used. The difference was statistically significant. Within the scope of this study, low-intensity pulsed ultrasound application after sinus lifting appeared to have a significant effect on the development of new bone formation.

  6. Low-intensity pulsed ultrasound treatment improved the rate of autograft peripheral nerve regeneration in rat

    PubMed Central

    Jiang, Wenli; Wang, Yuexiang; Tang, Jie; Peng, Jiang; Wang, Yu; Guo, Quanyi; Guo, Zhiyuan; Li, Pan; Xiao, Bo; Zhang, Jinxing

    2016-01-01

    Low intensity pulsed ultrasound (LIPUS) has been widely used in clinic for the treatment of repairing pseudarthrosis, bone fractures and of healing in various soft tissues. Some reports indicated that LIPUS accelerated peripheral nerve regeneration including Schwann cells (SCs) and injured nerves. But little is known about its appropriate intensities on autograft nerves. This study was to investigate which intensity of LIPUS improved the regeneration of gold standard postsurgical nerves in experimental rat model. Sprague-Dawley rats were made into 10 mm right side sciatic nerve reversed autologous nerve transplantation and randomly treated with 250 mW/cm2, 500 mW/cm2 or 750 mW/cm2 LIPUS for 2–12 weeks after operation. Functional and pathological results showed that LIPUS of 250 mW/cm2 significantly induced faster rate of axonal regeneration. This suggested that autograft nerve regeneration was improved. PMID:27102358

  7. Low-intensity pulsed ultrasound in lower limb bone stress injuries: a randomized controlled trial.

    PubMed

    Gan, Thomas Y; Kuah, Donald E; Graham, Kenneth S; Markson, Gregory

    2014-11-01

    To evaluate the effectiveness of low-intensity pulsed ultrasound (LIPUS) for the improvement of lower limb bone stress injuries in a civilian population. A prospective, randomized, double-blinded, placebo-controlled trial to compare LIPUS with placebo. Civilian private practice population in Sydney, Australia. Subjects were recruited if a grade II-IV bone stress injury was diagnosed on magnetic resonance imaging (MRI) of either the postero-medial tibia, fibula or second, third, or fourth metatarsal. Subjects of all levels of sporting activity were included. Thirty subjects were initially recruited, and 23 subjects were included in the final analysis. Subjects were randomized into either the treatment or placebo arm and matched to the site of injury (tibia, fibula, or metatarsal). Subjects in both arms used either treatment or placebo devices for 20 minutes daily for 4 weeks. Six clinical parameters (night pain, pain at rest, pain on walking, pain with running, tenderness, and pain with single leg hop) were compared before and after intervention. The changes in MRI grade and bone marrow edema size were also compared. There were no significant differences between the treatment and placebo conditions for changes in MRI grading (2.2 vs 2.4, P = 0.776) or bone marrow edema size (3 vs 4.1, P = 0.271). There were no significant differences between the treatment and placebo conditions for the 6 clinical parameters. Low-intensity pulsed ultrasound was found not to be an effective treatment for the healing of lower limb bone stress injuries in this study. However, this was measured over a relatively short duration of 4 weeks in a small, mostly female population. This double-blinded, randomized, placebo-controlled trial has shown that LIPUS is not an effective treatment for lower limb bone stress injuries.

  8. Low Intensity Pulsed Ultrasound (LIPUS) for the treatment of intervertebral disc degeneration

    NASA Astrophysics Data System (ADS)

    Horne, Devante; Jones, Peter; Salgaonkar, Vasant; Adams, Matt; Ozilgen, B. Arda; Zahos, Peter; Tang, Xinyan; Liebenberg, Ellen; Coughlin, Dezba; Lotz, Jeffrey; Diederich, Chris

    2017-02-01

    Discogenic back pain presents a major public health issue, with current therapeutic interventions limited to short-term symptom relief without providing regenerative remedies for diseased intervertebral discs (IVD). Many of these interventions are invasive and can diminish the biomechanical integrity of the IVDs. Low intensity pulsed ultrasound (LIPUS) is a potential treatment option that is both non-invasive and regenerative. LIPUS has been shown to be a clinically effective method for the enhancement of wound and fracture healing. Recent in vitro studies have shown that LIPUS stimulation induces an upregulation functional matrix proteins and downregulation of inflammatory factors in cultured IVD cells. However, we do not know the effects of LIPUS on an in vivo model for intervertebral disc degeneration. The objective of this study was to show technical feasibility of building a LIPUS system that can target the rat tail IVD and apply this setup to a model for acute IVD degeneration. A LIPUS exposimetry system was built using a 1.0 MHz planar transducer and custom housing. Ex vivo intensity measurements demonstrated LIPUS delivery to the center of the rat tail IVD. Using an established stab-incision model for disc degeneration, LIPUS was applied for 20 minutes daily for five days. For rats that displayed a significant injury response, LIPUS treatment caused significant upregulation of Collagen II and downregulation of Tumor Necrosis Factor - α gene expression. Our preliminary studies indicate technical feasibility of targeted delivery of ultrasound to a rat tail IVD for studies of LIPUS biological effects.

  9. The Role of Low-Intensity Pulsed Ultrasound on Cartilage Healing in Knee Osteoarthritis: A Review.

    PubMed

    Rothenberg, Joshua B; Jayaram, Prathap; Naqvi, Usker; Gober, Joslyn; Malanga, Gerard A

    2017-06-09

    Ultrasound (US) is a therapeutic modality that has been used in the treatment of musculoskeletal conditions for decades. In recent years, there have been technological advancements using low-intensity pulsed ultrasound (LIPUS) as a clinical modality. The purpose of this review was to critically examine the medical literature to determine the effects of LIPUS on the chondrogenic properties of knee osteoarthritis. A literature search of 3 major databases (PubMed, Scopus, and EMBASE) was performed. Two independent physician reviewers screened titles and abstracts, yielding a total of 18 relevant articles after the inclusion and exclusion criteria were applied. Results favored that LIPUS has a promising effect on the cellular elements in articular cartilage, specifically on chondrocytes in knee osteoarthritis. Although the use of LIPUS is encouraging based on basic science and preclinical data, there is a paucity of evidence with respect to humans. Consequently, there is insufficient evidence to recommend for or against LIPUS in clinical OA populations. We suggest future directions for research centered on LIPUS in both human and animal models to delineate the effect on the biologic properties of cartilage in knee osteoarthritis. To be determined. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  10. Preliminary Study on the Efficacy of Low Intensity Pulsed ultrasound for Osteoporosis

    NASA Astrophysics Data System (ADS)

    Yamanaka, Makoto; Koji, Akiyama; Tokita, Akihumi; Ishijima, Muneaki; Nozawa, Masahiko; Kurosawa, Hisashi

    2005-03-01

    Low-intensity pulsed ultrasound (LIPUS) has recently been shown to accelerate long bone fracture healing, but its effect on osteoporosis is not clear. The aim of this study is to investigate whether bone mineral density (BMD) of distal one-third radius of older woman is influenced with LIPUS. Six Japanese women who were outpatients at our hospital were recruited in this study and ranged from seventy to seventy-four years of age. In this study LIPUS exposed unilateral distal one-third of the radius for 20 min/once, 3 times and over every week for six months. The contralateral side was not exposed. The intensity of ultrasound was 30 mW/cm2 spatial-average temporal-average. Bone status was assessed by dual energy X-ray absorptiometry at baseline and 3 and 6 months later. Medication for osteoporosis were not changed. A significant increases in BMD at the treatment site were found in 3 women without alendronate and menatetrenone medication (averaged 4.5%). No significant differences were found in women on these medications. No remarkable changes were found away from the treatment site. These results suggest the possibility of effectiveness of LIPUS applied to a local area of osteoporosis and that pharmacological intervention is capable of influencing the effect of LIPUS for osteoporosis.

  11. Enhancement of cardiomyogenesis in stem cells by low intensity pulsed ultrasound

    NASA Astrophysics Data System (ADS)

    Teo, Ailing; Morshedi, Amir; Wang, Jen-Chieh; Lim, Mayasari; Zhou, Yufeng

    2017-03-01

    Low intensity pulsed ultrasound (LIPUS) has been shown to enhance bone and cartilage regeneration from stem cells. Gene expression of angiotensin II type 1 (AT1) receptor can be increased in LIPUS-treated osteoblasts. The AT1 receptor is a known mechanoreceptor in cardiomyocytes. It suggests that LIPUS may enhance cardiomyogenesis via mechanotransduction by increasing AT1 expression. Murine embryonic stem cells (ESCs) were treated daily by 10-min 1MHz LIPUS at spatial-average temporal-peak acoustic intensities of 30 mW/cm2 and 300 mW/cm2 in both continuous and pulsed wave (20% duty cycle) for 10 days. Polymerase chain reaction (PCR), immunocytochemistry, and beating rate were used to evaluate the cardiac viability quantitatively. After the treatment of LIPUS, beating rate of contractile areas and cardiac gene expression, such as α- and β-myosin heavy chain, were improved. Furthermore, no deleterious effects to the development of cardiac proteins were observed. All results suggest that LIPUS stimulation has the capacity of enhancing cardiomyogenesis from embryonic stem cells. With the benefit and the ease in incorporating LIPUS into various culture platforms, LIPUS has the potential to produce cardiomyocytes for clinical use in the future.

  12. Does Pulsed Low Intensity Ultrasound Allow Early Return to Normal Activities When Treating Stress Fractures?

    PubMed Central

    Brand, Jeff C; Brindle, Tim; Nyland, John; Caborn, David NM; Johnson, Darren L

    1999-01-01

    We sought to evaluate the efficacy of daily pulsed low intensity ultrasound (LIUS) with early return to activities for the treatment of lower extremity stress fractures. Eight patients (2 males, 6 females) with radiographic and bone scan confirmed tibial stress fractures participated in this study. Additionally, a case report of a tarsal navicular stress fracture is described. All patients except one were involved in athletics. Prior to the study, subjects completed a 5 question, 10 cm visual analog scale (VAS) regarding pain level (10 = extreme pain, 1 = no pain) and were assessed for functional performance. Subjects received 20-minute LIUS treatments 5 times a week for 4 weeks. Subjects maintained all functional activities during the treatment period. Seven patients with posterior-medial stress fractures participated without a brace. Subjects were re-tested after 4 weeks of treatment. Mann-Whitney U tests (VAS data) and paired t-tests (functional tests) assessed statistical significance (p<0.05). Although the intensity of practice was diminished in some instances, no time off from competitive sports was prescribed for the patients with the tibial stress fractures. The patient with the anterior tibial stress fracture underwent tibial intramedullary nailing at the conclusion of a season of play. In this uncontrolled experience, treatment of tibial stress fractures with daily pulsed LIUS was effective in pain relief and early return to vigorous activity without bracing for the patients with posterior-medial stress fractures. PMID:10847513

  13. Design evolution enhances patient compliance for low-intensity pulsed ultrasound device usage

    PubMed Central

    Pounder, Neill M; Jones, John T; Tanis, Kevin J

    2016-01-01

    Poor patient compliance or nonadherence with prescribed treatments can have a significant unfavorable impact on medical costs and clinical outcomes. In the current study, voice-of-the-customer research was conducted to aid in the development of a next-generation low-intensity pulsed ultrasound (LIPUS) bone healing product. An opportunity to improve patient compliance reporting was identified, resulting in the incorporation into the next-generation device of a visual calendar that provides direct feedback to the patient, indicating days for which they successfully completed treatment. Further investigation was done on whether inclusion of the visual calendar improved patient adherence to the prescribed therapy (20 minutes of daily treatment) over a 6-month period. Thus, 12,984 data files were analyzed from patients prescribed either the earlier- or the next-generation LIPUS device. Over the 6-month period, overall patient compliance was 83.8% with the next-generation LIPUS device, compared with 74.2% for the previous version (p<0.0001). Incorporation of the calendar feature resulted in compliance never decreasing below 76% over the analysis period, whereas compliance with the earlier-generation product fell to 51%. A literature review on the LIPUS device shows a correlation between clinical effectiveness and compliance rates more than 70%. Incorporation of stakeholder feedback throughout the design and innovation process of a next-generation LIPUS device resulted in a measurable improvement in patient adherence, which may help to optimize clinical outcomes. PMID:27942237

  14. Low-intensity pulsed ultrasound therapy: a potential strategy to stimulate tendon-bone junction healing*

    PubMed Central

    Ying, Zhi-min; Lin, Tiao; Yan, Shi-gui

    2012-01-01

    Incorporation of a tendon graft within the bone tunnel represents a challenging clinical problem. Successful anterior cruciate ligament (ACL) reconstruction requires solid healing of the tendon graft in the bone tunnel. Enhancement of graft healing to bone is important to facilitate early aggressive rehabilitation and a rapid return to pre-injury activity levels. No convenient, effective or inexpensive procedures exist to enhance tendon-bone (T-B) healing after surgery. Low-intensity pulsed ultrasound (LIPUS) improves local blood perfusion and angiogenesis, stimulates cartilage maturation, enhances differentiation and proliferation of osteoblasts, and motivates osteogenic differentiation of mesenchymal stem cells (MSCs), and therefore, appears to be a potential non-invasive tool for T-B healing in early stage of rehabilitation of ACL reconstruction. It is conceivable that LIPUS could be used to stimulate T-B tunnel healing in the home, with the aim of accelerating rehabilitation and an earlier return to normal activities in the near future. The purpose of this review is to demonstrate how LIPUS stimulates T-B healing at the cellular and molecular levels, describe studies in animal models, and provide a future direction for research. PMID:23225850

  15. Pulsed low-intensity ultrasound therapy for chronic lateral epicondylitis: a randomized controlled trial.

    PubMed

    D'Vaz, A P; Ostor, A J K; Speed, C A; Jenner, J R; Bradley, M; Prevost, A T; Hazleman, B L

    2006-05-01

    Pulsed low-intensity ultrasound therapy (LIUS) has been found to be beneficial in accelerating fracture healing and has produced positive results in animal tendon repair. In the light of this we undertook a randomized, double-blind, placebo controlled trial to assess the effectiveness of LIUS vs placebo therapy daily for 12 weeks in patients with chronic lateral epicondylitis (LE). Patients with LE of at least 6 weeks' duration were recruited from general practice, physiotherapy and rheumatology clinics, and had to have failed at least one first-line treatment including non steroidal anti-inflammatory drugs (NSAIDs) and corticosteroid injection. Participants were assigned either active LIUS or placebo. Treatment was self-administered daily for 20 min over a 12-week period. The primary end-point was a 50% improvement from baseline in elbow pain measured at 12 weeks using a patient-completed visual analogue scale. Fifty-five subjects aged 18-80 were recruited over a 9-month period. In the active group 64% (16/25) achieved at least 50% improvement from baseline in elbow pain at 12 weeks compared with 57% (13/23) in the placebo group (difference of 7%; 95% confidence interval -20 to 35%). However, this was not statistically significant (chi(2) = 0.28, P = 0.60). In this study LIUS was no more effective for a large treatment effect than placebo for recalcitrant LE. This is in keeping with other interventional studies for the condition.

  16. Effect of Low-intensity Pulsed Ultrasound on Postorthognathic Surgery Healing Process

    PubMed Central

    Tehranchi, Azita; Badiee, Mohamadreza; Younessian, Farnaz; Badiei, Mohamadreza; Haddadpour, Sahar

    2017-01-01

    Background: Orthognathic surgery can cause discomforts such as pain, inflammation, and edema. One of the challenges is bone regeneration at surgery area. The aim of this study is to evaluate the effect of low-intensity pulsed ultrasound (LIPUS) therapy on bone regeneration and pain relief after surgery. Materials and Methods: Following mandibular surgery of nine patients, LIPUS treatment was applied to the left or right side for 3 weeks and 20 min/day. The other side was treated with sham-LIPUS as the control group. Digital panoramic radiographies were obtained immediately after surgery and 3 weeks later. Bone density at surgery site was assessed using Digora version 2.8 software. The data were analyzed with one-sample Kolmogorov–Smirnov and t-paired test. Postoperation pain was evaluated by means of visual analog scale. Results: Increase in bone density at border and medulla was 23 and 28.33 for experimental group and 13 and 13.55 units in control group, respectively. The differences are statistically significant (P < 0.01). Variance analysis showed that decrease in experienced pain during 3 weeks after surgery was significantly different between groups (P < 0.01). Conclusion: LIPUS can be an effective way to increase bone modeling and decrease pain following orthognathic surgeries. PMID:28713732

  17. Clinical and immunohistopathological aspects of venous ulcers treatment by Low-Intensity Pulsed Ultrasound (LIPUS).

    PubMed

    de Ávila Santana, Luísiane; Alves, José Marcos; Andrade, Thiago Antônio Moretti; Kajiwara, João Kazuyuki; Garcia, Sérgio Britto; Gomes, Fernanda Guzzo; Frade, Marco Andrey Cipriani

    2013-04-01

    The immunological mechanisms that are triggered by Low-Intensity Pulsed Ultrasound (LIPUS) in wound healing are unknown. In the present study, experimental groups were used to assess the treatment of chronic venous ulcers with 30mW/cm(2) SATA peripheral LIPUS three times per week compared to a daily treatment of 1% silver sulfadiazine (SDZ). The ulcers of the SDZ group (n=7) (G1) and LIPUS group (n=9) (G2) were photographed five times three months, and the images were analyzed using ImageJ software to quantify the total area (S), fibrin/sphacel area (yellow) and granulation area (red). The healing process was evaluated by the wound healing rate (WHR), granulation tissue rate (GTR) and fibrin/sphacel tissue rate (FTR). The ulcers were biopsied on days 1 and 45 and stained for collagen fiber quantification (picrosirius) and CD68(+) protein and VEGF (vascular endothelial growth factor) expression using HRP-streptavidin (horseradish peroxidase-streptavidin). On day 90, G2 had a mean 41% decrease in the ulcer area, while no decrease was observed in G1 (p<0.05). An increased tendency toward positive labeling of collagen fibers and VEGF (p>0.05) was observed in G2 compared to G1, and the number of CD68(+) cells was greater in G2 than in G1 (p<0.05). LIPUS presents superior activity compared to SDZ in stimulating the inflammatory and proliferative (angiogenesis and collagenesis, respectively) phases of chronic venous wound healing.

  18. Low-intensity pulsed ultrasound therapy: a potential strategy to stimulate tendon-bone junction healing.

    PubMed

    Ying, Zhi-min; Lin, Tiao; Yan, Shi-gui

    2012-12-01

    Incorporation of a tendon graft within the bone tunnel represents a challenging clinical problem. Successful anterior cruciate ligament (ACL) reconstruction requires solid healing of the tendon graft in the bone tunnel. Enhancement of graft healing to bone is important to facilitate early aggressive rehabilitation and a rapid return to pre-injury activity levels. No convenient, effective or inexpensive procedures exist to enhance tendon-bone (T-B) healing after surgery. Low-intensity pulsed ultrasound (LIPUS) improves local blood perfusion and angiogenesis, stimulates cartilage maturation, enhances differentiation and proliferation of osteoblasts, and motivates osteogenic differentiation of mesenchymal stem cells (MSCs), and therefore, appears to be a potential non-invasive tool for T-B healing in early stage of rehabilitation of ACL reconstruction. It is conceivable that LIPUS could be used to stimulate T-B tunnel healing in the home, with the aim of accelerating rehabilitation and an earlier return to normal activities in the near future. The purpose of this review is to demonstrate how LIPUS stimulates T-B healing at the cellular and molecular levels, describe studies in animal models, and provide a future direction for research.

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

    PubMed

    Bernal, Aurora; Pérez, Laura M; De Lucas, Beatriz; Martín, Nuria San; Kadow-Romacker, Anke; Plaza, Gustavo; Raum, Kay; Gálvez, Beatriz G

    2015-12-01

    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 non-invasive 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.

  20. Inhibitory effects of low-intensity pulsed ultrasound sonication on the proliferation of osteosarcoma cells.

    PubMed

    Matsuo, Toshihiro; Sato, Keiji; Matsui, Takuya; Sawada, Shigeyuki; Muramatsu, Yoshitaka; Kawanami, Katsuhisa; Deie, Masataka

    2017-09-01

    To date, there is limited data on the biological effects of low-intensity pulsed ultrasound (LIPUS) on primary malignant bone tumors. The purpose of the present study was to investigate the antitumor effects of LIPUS on osteosarcoma cells. The effects of LIPUS on cell viability, induction of apoptosis, mitochondrial membrane potential and intracellular signaling molecules in the LM8 osteosarcoma cell line were investigated. LIPUS inhibited cell viability (P=0.0022) and mitochondrial membrane potential (P=0.0019) in LM8 cells. Flow cytometry analysis and terminal deoxynucleotidyl transferase dUTP nick end labeling staining revealed significantly higher numbers of apoptotic (P<0.0001) and necrotic cells (P=0.0091) compared with cells without treatment. LIPUS treatment significantly increased phosphorylated Akt (P<0.0001) and IκBα (P=0.0001) levels, and reduced phosphorylated mitogen-activated protein kinase 7 (P<0.0001) and phosphorylated checkpoint kinase 1 (P=0.0008) levels. These results suggest that LIPUS is a non-invasive adjuvant therapy that is able to inhibit cellular proliferation in osteosarcoma cells.

  1. Low-intensity pulsed ultrasound stimulation promotes osteoblast differentiation through hedgehog signaling.

    PubMed

    Matsumoto, Kenichi; Shimo, Tsuyoshi; Kurio, Naito; Okui, Tatsuo; Ibaragi, Soichiro; Kunisada, Yuki; Obata, Kyoichi; Masui, Masanori; Pai, Pang; Horikiri, Yuu; Yamanaka, Nobuyuki; Takigawa, Masaharu; Sasaki, Akira

    2017-10-05

    Low-intensity pulsed ultrasound (LIPUS) has been used as an adjunct to fracture healing therapies, but the mechanisms underlying its action are not known. We reported that sonic hedgehog (SHH) signaling was activated in osteoblasts at the dynamic remodeling site of a bone fracture. Mechanical stimulation is a crucial factor in bone remodeling, and it is related to the primary cilia as a sensor of hedgehog signaling. Here we observed that LIPUS promoted callus formation in accord with Gli2-positive cells after 14 days at the mouse femur fractured site compared with a control group. An immunofluorescence analysis showed that the numbers of primary cilia and cilia/osterix double-positive osteoblasts were increased at the fracture site by LIPUS. LIPUS stimulated not only the number and the length of primary cilia, but also the levels of ciliated protein, Ift88 mRNA, and SHH, Gli1 and Gli2 in MC3T3-E1 cells. Further experiments revealed that LIPUS stimulated osteogenic differentiation in the presence of smoothened agonist (SAG) treatment. These results indicate that LIPUS stimulates osteogenic differentiation and the maturation of osteoblasts by a primary cilium-mediated activation of hedgehog signaling. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Low-intensity Pulsed Ultrasound Stimulation for Tendon-Bone Healing: A Dose-dependent Study.

    PubMed

    Lu, Hongbin; Liu, Fei; Chen, Can; Wang, Zhanwen; Chen, Huabin; Qu, Jin; Zhang, Tao; Xu, Daqi; Hu, Jianzhong

    2017-10-07

    This study aimed to evaluate the dosage effect of low-intensity pulsed ultrasound stimulation (LIPUS) on tendon-bone (T-B) healing. Standard partial patellectomies were performed on 120 mature New Zealand rabbits randomly assigned into three groups: a control group (daily mock sonication, 20 min), a qd group (daily ultra-sonication, 20 min), and a bid group (ultra-sonication twice a day, 20 min each time). The rabbits were sacrificed 8 or 16 weeks postoperatively, and the microarchitectural, histological, and mechanical properties of the patella-patellar tendon (PPT) interface were evaluated. Micro-computed tomography analysis showed that the bid group exhibited more new bone formation and mineralization than the other groups in the T-B healing position at both 8 and 16 weeks postoperatively. Histological assessments confirmed the bid group exhibited a significantly better PPT interface than the other groups, as shown by the increased formation and remodeling of newly formed bone and a fibrocartilage layer. The biomechanical properties of the regenerated PPT interface significantly improved in the bid group. LIPUS treatment twice a day was more effective than the once-a-day treatment on tendon-bone healing.

  3. Design evolution enhances patient compliance for low-intensity pulsed ultrasound device usage.

    PubMed

    Pounder, Neill M; Jones, John T; Tanis, Kevin J

    2016-01-01

    Poor patient compliance or nonadherence with prescribed treatments can have a significant unfavorable impact on medical costs and clinical outcomes. In the current study, voice-of-the-customer research was conducted to aid in the development of a next-generation low-intensity pulsed ultrasound (LIPUS) bone healing product. An opportunity to improve patient compliance reporting was identified, resulting in the incorporation into the next-generation device of a visual calendar that provides direct feedback to the patient, indicating days for which they successfully completed treatment. Further investigation was done on whether inclusion of the visual calendar improved patient adherence to the prescribed therapy (20 minutes of daily treatment) over a 6-month period. Thus, 12,984 data files were analyzed from patients prescribed either the earlier- or the next-generation LIPUS device. Over the 6-month period, overall patient compliance was 83.8% with the next-generation LIPUS device, compared with 74.2% for the previous version (p<0.0001). Incorporation of the calendar feature resulted in compliance never decreasing below 76% over the analysis period, whereas compliance with the earlier-generation product fell to 51%. A literature review on the LIPUS device shows a correlation between clinical effectiveness and compliance rates more than 70%. Incorporation of stakeholder feedback throughout the design and innovation process of a next-generation LIPUS device resulted in a measurable improvement in patient adherence, which may help to optimize clinical outcomes.

  4. Effect of low-intensity pulsed ultrasound on orthodontically induced root resorption in beagle dogs.

    PubMed

    Al-Daghreer, Saleh; Doschak, Michael; Sloan, Alastair J; Major, Paul W; Heo, Giseon; Scurtescu, Cristian; Tsui, Ying Y; El-Bialy, Tarek

    2014-06-01

    We investigated the effect of low-intensity pulsed ultrasound (LIPUS) on orthodontically induced inflammatory root resorption in vivo. Ten beagle dogs were treated with an orthodontic appliance to move the mandibular fourth premolars bodily. The orthodontic movement was carried out for 4 wk with a continuous force of 1 N/side; using a split-mouth model, LIPUS was applied daily for 20 min. Fourth premolar and surrounding periodontal tissue were evaluated with micro-computed tomography and hematoxylin and eosin and tartrate-resistant acid phosphatase staining. We calculated the number, volume and distribution of root resorption lacunae and their percentage relative to total root volume, orthodontic tooth movement and periodontal ligament space. There was no significant difference in orthodontic tooth movement between the two sides. LIPUS significantly reduced the number of orthodontically induced inflammatory root resorption initiation areas by 71%, reduced their total volume by 68% and reduced their volume relative to the affected root total volume by 70%. LIPUS induced the formation of a precementum layer, thicker cementum and reparative cellular cementum.

  5. Identification of genes responsive to low intensity pulsed ultrasound in a human leukemia cell line Molt-4.

    PubMed

    Tabuchi, Yoshiaki; Ando, Hidetaka; Takasaki, Ichiro; Feril, Loreto B; Zhao, Qing-Li; Ogawa, Ryohei; Kudo, Nobuki; Tachibana, Katsuro; Kondo, Takashi

    2007-02-08

    We examined the gene expression of human leukemia Molt-4 cells treated with non-thermal low intensity pulsed ultrasound. Six hours after 0.3W/cm(2) pulsed ultrasound treatment, apoptosis (24+/-3.3%, mean+/-SD) with minimal cell lysis was observed. Of approximately 16,600 genes analyzed, BCL2-associated athanogene 3 (BAG3), DnaJ (Hsp40) homolog, subfamily B, member 1 (DNAJB1), heat shock 70 kDa protein 1B (HSPA1B), and heat shock 70 kDa protein 6 (HSPA6) showed increased levels of expression while isopentenyl-diphosphate delta isomerase (IDI1) and 3-hydroxy-3-methylglutaryl-coenzyme A synthase 1 (HMGCS1) showed decreased levels in the cells 3h after the ultrasound treatment. The expression levels of these six genes were confirmed by a real-time quantitative polymerase chain reaction. To our knowledge, this is the first report of DNA microarray analysis of genes that are differentially expressed in response to apoptosis induced by non-thermal low intensity pulsed ultrasound in human leukemia cells. The present results will provide a basis for further understanding of the molecular mechanisms of effects of not only low intensity pulsed ultrasound but also that of mechanical shear stress in the cells.

  6. Effect of low-intensity pulsed ultrasound therapy on a rat knee joint contracture model.

    PubMed

    Watanabe, Masanori; Kojima, Satoshi; Hoso, Masahiro

    2017-09-01

    [Purpose] Histopathological investigation of the effects of low-intensity pulsed ultrasound (LIPUS) on joint components using a rat knee joint contracture model. [Subjects and Methods] Nineteen, 9-week-old Wistar male rats were divided into a control group (n=6) and an experimental group. Rats in the experimental group underwent cast immobilization of the right rear limb for 8 weeks. They were then randomly divided into a non-treatment group (n=6), which was raised under normal conditions for 4 weeks, and a treatment group (n=7), which underwent LIPUS for 4 weeks. LIPUS irradiation was performed at a frequency of 3 MHz, an intensity of 30 mW/cm(2), and a pulse rate of 20% duty cycle. Irradiation was performed once daily for 10 min, 5 days per week. At the end of this period, tissue specimens in which the knee sagittal plane could be observed were prepared and observed using an optical microscope. [Results] The extension-limiting angle of the knee joint was significantly less in the treatment group compared with the non-treatment group. The posterior joint capsule was significantly thicker only in the non-treatment group, and the density was 53.5 ± 7.5% for the control group, 77.2 ± 5.7% for the non-treatment group, and 69.2 ± 2.9% for the treatment group, with significant differences existing across all groups. [Conclusion] LIPUS may widen the space between collagen fiber bundles of the joint capsule, thereby improving the range of motion.

  7. Effect of Low-Intensity Pulsed Ultrasound on Distraction Osteogenesis Treatment Time: A Meta-analysis of Randomized Clinical Trials.

    PubMed

    Raza, Hasnain; Saltaji, Humam; Kaur, Harmanpreet; Flores-Mir, Carlos; El-Bialy, Tarek

    2016-02-01

    The objectives of this systematic review with a meta-analysis were to critically analyze the available scientific literature regarding the effects of low-intensity pulsed ultrasound (US) on stimulating bone regeneration and bone maturation during distraction osteogenesis in humans and to determine whether the stimulatory effect of low-intensity pulsed US can effectively reduce the associated treatment time. Studies were considered for inclusion if they were randomized clinical trials that examined the effect of low-intensity pulsed US on distraction osteogenesis compared to conventional distraction osteogenesis. The primary outcome was reduced treatment time. Study selection, risk of bias assessment, and data extraction were performed in duplicate. A random-effects meta-analysis model was used when more than 3 trials were eligible for a quantitative analysis and considering the expected differences in interventions and measurement tools. Five randomized clinical trials, with a moderate to high risk of bias, met the eligibility criteria. Four trials examining tibial distraction osteogenesis in 118 patients were combined in a meta-analysis. A statistically significant difference for reduced treatment time between distraction osteogenesis with low-intensity pulsed US and standard distraction osteogenesis was evident (mean difference, -15.236 d/cm; random-effects 95% confidence interval, -19.902 to -10.569 d/cm; P < .0001). As for the mandible, only 1 clinical trial was available, which showed no significant effect of low-intensity pulsed US therapy on distraction osteogenesis. Current available evidence suggests that low-intensity pulsed US therapy may provide a reduction in the overall treatment time for tibial distraction osteogenesis. However, this conclusion should be considered with caution, given the moderate to high risk of bias in the included randomized clinical trials. © 2016 by the American Institute of Ultrasound in Medicine.

  8. Low-intensity pulsed ultrasound regulates proliferation and differentiation of osteoblasts through osteocytes

    SciTech Connect

    Li, Lei; Yang, Zheng; Zhang, Hai; Chen, Wenchuan; Chen, Mengshi; Zhu, Zhimin

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes inhibits proliferation of osteoblasts. Black-Right-Pointing-Pointer CM from LIPUS-stimulated osteocytes enhances differentiation of osteoblasts. Black-Right-Pointing-Pointer LIPUS stimulates MLO-Y4 cells to secrete PGE{sub 2} and NO. -- Abstract: Low-intensity pulsed ultrasound (LIPUS) has been used as a safe and effective modality to enhance fracture healing. As the most abundant cells in bone, osteocytes orchestrate biological activities of effector cells via direct cell-to-cell contacts and by soluble factors. In this study, we have used the osteocytic MLO-Y4 cells to study the effects of conditioned medium from LIPUS-stimulated MLO-Y4 cells on proliferation and differentiation of osteoblastic MC3T3-E1 cells. Conditioned media from LIPUS-stimulated MLO-Y4 cells (LIPUS-Osteocyte-CM) were collected and added on MC3T3-E1 cell cultures. MC3T3-E1 cells cultured in LIPUS-Osteocyte-CM demonstrated a significant inhibition of proliferation and an increased alkaline phosphatase activity. The results of PGE{sub 2} and NO assay showed that LIPUS could enhance PGE{sub 2} and NO secretion from MLO-Y4 cells at all time points within 24 h after LIPUS stimulation. We conclude that LIPUS regulates proliferation and differentiation of osteoblasts through osteocytes in vitro. Increased secretion of PGE{sub 2} from osteocytes may play a role in this effect.

  9. Low-intensity pulsed ultrasound reduces periodontal atrophy in occlusal hypofunctional teeth.

    PubMed

    Kasahara, Yuki; Usumi-Fujita, Risa; Hosomichi, Jun; Kaneko, Sawa; Ishida, Yuji; Shibutani, Naoki; Shimizu, Yasuhiro; Okito, Asuka; Oishi, Shuji; Kuma, Yoichiro; Yamaguchi, Hiroyuki; Ono, Takashi

    2017-09-01

    To clarify whether low-intensity pulsed ultrasound (LIPUS) exposure has recovery effects on the hypofunctional periodontal ligament (PDL) and interradicular alveolar bone (IRAB). Twelve-week-old male Sprague-Dawley rats were divided into three groups (n = 5 each): a normal occlusion (C) group, an occlusal hypofunction (H) group, and an occlusal hypofunction group subjected to LIPUS (HL) treatment. Hypofunctional occlusion of the maxillary first molar (M1) of the H and HL groups was induced by the bite-raising technique. Only the HL group was irradiated with LIPUS for 5 days. The IRAB and PDL of M1 were examined by microcomputed tomography (micro-CT) analysis. To quantify mRNA expression of cytokines involved in PDL proliferation and development, real-time reverse transcription quantitative PCR (qRT-PCR) was performed for twist family bHLH transcription factor 1 (Twist1), periostin, and connective tissue growth factor (CTGF) in the PDL samples. Micro-CT analysis showed that the PDL volume was decreased in the H group compared with that of the C and HL groups. Both bone volume per tissue volume (BV/TV) of IRAB was decreased in the H group compared with that in the C group. LIPUS exposure restored BV/TV in the IRAB of the HL group. qRT-PCR analysis showed that Twist1, periostin, and CTGF mRNA levels were decreased in the H group and increased in the HL group. LIPUS exposure reduced the atrophic changes of alveolar bone by inducing the upregulation of periostin and CTGF expression to promote PDL healing after induction of occlusal hypofunction.

  10. Does Low-intensity pulsed ultrasound treatment repair articular cartilage injury? A rabbit model study

    PubMed Central

    2014-01-01

    Background Low-intensity pulsed ultrasound (LIPUS) regiment has been used to treat fractures with non-union and to promote bone union in general. The effect of LIPUS on articular cartilage metabolism has been characterized. Yet, the effect of LIPUS to repair articular cartilage injury remains unclear in vivo. Methods We designed a study to investigate the effect of LIPUS on articular cartilage repairing in a rabbit severe cartilage injury model. Eighteen rabbits were divided into three groups: Sham-operated group, operated group without-LIPUS-treatment, operated group with-LIPUS-treatment (a daily 20-minute treatment for 3 months). Full-thickness cartilage defects were surgically created on the right side distal femoral condyle without intending to penetrate into the subchondral bone, which mimicked severe chondral injury. MR images for experimental joints, morphology grading scale, and histopathological Mankin score were evaluated. Results The preliminary results showed that the operated groups with-LIPUS-treatment and without-LIPUS-treatment had significantly higher Mankin score and morphological grading scale compared with the sham-operated group. However, there was no significant difference between the with-LIPUS-treatment and without-LIPUS-treatment groups. Cartilage defects filled with proliferative tissue were observed in the with-LIPUS-treatment group grossly and under MR images, however which presented less up-take under Alcian blue stain. Furthermore, no new deposition of type II collagen or proliferation of chondrocyte was observed over the cartilage defect after LIPUS treatment. Conclusion LIPUS has no significant therapeutic potential in treating severe articular cartilage injury in our animal study. PMID:24507771

  11. Preliminary Treatment of Achilles Tendinopathy Using Low-Intensity Pulsed Ultrasound.

    PubMed

    Hsu, Andrew R; Holmes, George B

    2016-02-01

    Achilles tendinopathy is a degenerative process of the tendon associated with diminished vascularity, microtrauma, and aging. Nonoperative treatments such as activity modification, immobilization, night splints, and physical therapy have good outcomes for the majority of patients. However, there are cohorts of patients that remain symptomatic despite use of all nonoperative measures that eventually require surgical intervention. The present study reports the preliminary short-term clinical outcomes of low-intensity pulsed ultrasound (LIPUS) for treatment for Achilles tendinopathy. Fourteen patients with clinically diagnosed Achilles tendinopathy who failed previous nonoperative treatments underwent LIPUS stimulation directly over the area of maximum tendon tenderness for 20 min/d for 8 weeks total. No other treatment modalities were used during the period of LIPUS stimulation. All patients had serial clinical exams and evaluations with an average follow-up of 12 months (range, 6-50 months). Excellent clinical outcomes with complete resolution of pain and other symptoms were obtained in 7 patients (50%). Two patients (14%) had good outcomes with mild tendon irritation and stiffness not requiring further intervention. Five patients (36%) had minimal benefit with continued pain, swelling, and tenderness over the Achilles and functional deficits. No patients had worsening pain or progression of disability requiring surgery. LIPUS is an additional noninvasive treatment modality for chronic Achilles tendinopathy that may potentially help improve clinical symptoms and delay and/or prevent the need for surgical intervention. While LIPUS is easy to use, well-tolerated, and has promising early clinical results, further research is needed to determine the long-term benefits, disadvantages, and cost-effectiveness of this alternative treatment for tendinopathy. Therapeutic, Level IV: Case series. © 2015 The Author(s).

  12. Efficacy of low-intensity pulsed ultrasound in the prevention of osteoporosis following spinal cord injury.

    PubMed

    Warden, S J; Bennell, K L; Matthews, B; Brown, D J; McMeeken, J M; Wark, J D

    2001-11-01

    Ultrasound (US), a high-frequency acoustic energy traveling in the form of a mechanical wave, represents a potential site-specific intervention for osteoporosis. Bone is a dynamic tissue that remodels in response to applied mechanical stimuli. As a form of mechanical stimulation, US is anticipated to produce a similar remodeling response. This theory is supported by growing in vitro and in vivo evidence demonstrating an osteogenic effect of pulsed-wave US at low spatial-averaged temporal-averaged intensities. The aim of this study was to investigate whether low-intensity pulsed US could prevent calcaneal osteoporosis in individuals following spinal cord injury (SCI). Fifteen patients with a 1-6 month history of SCI were recruited. Active US was introduced to one heel for 20 min/day, 5 days/week, over 6 weeks. The contralateral heel was simultaneously treated with inactive US. Patients were blind to which heel was being actively treated. Active US pulsed with a 10 microsec burst of 1.0 MHz sine waves repeating at 3.3 kHz. The spatial-averaged temporal-averaged intensity was set at 30 mW/cm(2). Bone status was assessed at baseline and following the intervention period by dual-energy X-ray absorptiometry and quantitative US. SCI resulted in significant bone loss. Bone mineral content decreased by 7.5 +/- 3.0% in inactive US-treated calcanei (p < 0.001). Broadband US attenuation and speed of sound decreased by 8.5 +/- 6.9% (p < 0.001) and 1.5 +/- 1.3% (p < 0.001), respectively. There were no differences between active and inactive US-treated calcanei for any skeletal measure (p > 0.05). These findings confirm the negative skeletal impact of SCI, and demonstrate that US at the dose and mode administered was not a beneficial intervention for SCI-induced osteoporosis. This latter finding may primarily relate to the inability of US to effectively penetrate the outer cortex of bone due to its acoustic properties.

  13. Pulsed low-intensity ultrasound: a new salvage procedure for delayed unions and nonunions after leg lengthening in children.

    PubMed

    Gebauer, Dieter; Correll, Johannes

    2005-01-01

    From 1998 to 2001, 112 lengthening procedures with or without deformity correction were performed in 108 children by external fixation with the Ilizarov method. Of these cases, 16.9% did not lead to a solid bone consolidation. Two children were operated the second time, mainly because of the parent's decision. Seventeen delayed unions or nonunions in 13 children were treated with low-intensity pulsed ultrasound. All 17 cases healed within 3 to 12 months without any risk of surgical intervention.

  14. Effect of low-intensity pulsed ultrasound on l929 fibroblasts

    PubMed Central

    Franco de Oliveira, Rodrigo; Pires Oliveira, Deise A. A.; Soares, Cristina Pacheco

    2011-01-01

    Introduction Ultrasound has proven to be an important therapeutic resource regarding musculoskeletal disease and is routinely used in physical therapy and medicine both therapeutically and diagnostically. The aim of the present study was to analyse the effects with different ultrasound intensities in order to establish the ideal radiation level in cell cultures. Material and methods Fibroblast cell cultures were divided into five groups: group I – control (did not receive irradiation); group II – 0.2 W/cm2 in pulsed mode at 10% (1 : 9 duty cycle); group III – 0.6 W/cm2 in pulsed mode at 10% (1 : 9 duty cycle); group IV – 0.2 W/cm2 in pulsed mode at 20% (2 : 8 duty cycle); and group V – 0.6 W/cm2 in pulsed mode at 20% (2 : 8 duty cycle). Each group was irradiated with 24-h intervals, observing the following post-irradiation incubation times: 24, 48, 72 and 96 h; after 24 h of each irradiation, cultures were analysed using the MTT method. Results Analysis of the results following ultrasound irradiation demonstrated that the effect of ultrasound with 0.6 W/cm2 in pulsed mode at 10% (1 : 9 duty cycle) was statistically significant in relation to ultrasonic irradiation in pulsed mode at 20% (2 : 8 duty cycle) (p < 0.05). Conclusions According to parameters used in the irradiation of cultivated fibroblasts, the pulse mode regime and the control of intensity are of fundamental importance for the optimal use of therapeutic ultrasound. Furthermore, low and medium intensities decreased cell damage, which establishes that acoustic pulsed energy induces the proliferation of fibroblast cells. PMID:22291760

  15. Low-Intensity Pulsed Ultrasound Stimulation Facilitates Osteogenic Differentiation of Human Periodontal Ligament Cells

    PubMed Central

    Hu, Bo; Zhang, Yuanyuan; Zhou, Jie; Li, Jing; Deng, Feng; Wang, Zhibiao; Song, Jinlin

    2014-01-01

    Human periodontal ligament cells (hPDLCs) possess stem cell properties, which play a key role in periodontal regeneration. Physical stimulation at appropriate intensities such as low-intensity pulsed ultrasound (LIPUS) enhances cell proliferation and osteogenic differentiation of mesechymal stem cells. However, the impacts of LIPUS on osteogenic differentiation of hPDLCs in vitro and its molecular mechanism are unknown. This study was undertaken to investigate the effects of LIPUS on osteogenic differentiation of hPDLCs. HPDLCs were isolated from premolars of adolescents for orthodontic reasons, and exposed to LIPUS at different intensities to determine an optimal LIPUS treatment dosage. Dynamic changes of alkaline phosphatase (ALP) activities in the cultured cells and supernatants, and osteocalcin production in the supernatants after treatment were analyzed. Runx2 and integrin β1 mRNA levels were assessed by reverse transcription polymerase chain reaction analysis after LIPUS stimulation. Blocking antibody against integrinβ1 was used to assess the effects of integrinβ1 inhibitor on LIPUS-induced ALP activity, osteocalcin production as well as calcium deposition. Our data showed that LIPUS at the intensity of 90 mW/cm2 with 20 min/day was more effective. The ALP activities in lysates and supernatants of LIPUS-treated cells started to increase at days 3 and 7, respectively, and peaked at day 11. LIPUS treatment significantly augmented the production of osteocalcin after day 5. LIPUS caused a significant increase in the mRNA expression of Runx2 and integrin β1, while a significant decline when the integrinβ1 inhibitor was used. Moreover, ALP activity, osteocalcin production as well as calcium nodules of cells treated with both daily LIPUS stimulation and integrinβ1 antibody were less than those in the LIPUS-treated group. In conclusion, LIPUS promotes osteogenic differentiation of hPDLCs, which is associated with upregulation of Runx2 and integrin β1, which

  16. Low-intensity pulsed ultrasound treatment for postoperative delayed union or nonunion of long bone fractures.

    PubMed

    Jingushi, Seiya; Mizuno, Kosaku; Matsushita, Takashi; Itoman, Moritoshi

    2007-01-01

    Postoperative delayed union and nonunion is the most common complication in fracture treatment. Recent studies have shown an accelerating effect of low-intensity pulsed ultrasound (LIPUS) on fracture repair. However, the indications for delayed union and nonunion are not clear. To clarify the factors which influence the effects of LIPUS, the data from a previous prospective multicenter study on LIPUS treatment for postoperative delayed union and nonunion of long bone fractures were reanalyzed. Seventy-two cases of long bone fracture, including those of the femur, tibia, humerus, radius, and ulna, were analyzed. The mean time from the most recent operation to the beginning of LIPUS treatment was 11.5 (3-68) months. The relationship between the background factors and the union rate was analyzed using a logistic regression method. In addition, long bone fractures in an upper extremity or in a lower extremity were analyzed separately. The union rate was 75% in all the cases of long bone fracture. There was a significant relationship between the union rate and the period from the most recent operation to the beginning of LIPUS treatment in all cases and in those that had long bone fracture of an upper extremity. There was also a significant relationship between the union rate and the time when a radiological improvement was first observed after the beginning of the treatment in all cases and in those with fractures in a lower extremity. When LIPUS treatment was started within 6 months of the most recent operation, 89.7% of all fractures healed. When an improvement in the radiological changes at the fracture site was observed after 4 months in those cases, then the sensitivity and specificity for union were more than 90%. LIPUS treatment should be started within 6 months of the most recent operation. Because LIPUS has been shown to be effective without causing either serious invasiveness or any undue risk to the patient, it may be considered the treatment of first choice

  17. Low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments affect degeneration of cultured articular cartilage explants.

    PubMed

    Tan, Lijun; Ren, Yijin; van Kooten, Theo G; Grijpma, Dirk W; Kuijer, Roel

    2015-03-01

    Articular cartilage has some capacity for self-repair. Clinically used low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments were compared in their potency to prevent degeneration using an explant model of porcine cartilage. Explants of porcine cartilage and human osteoarthritic cartilage were cultured for four weeks and subjected to daily LIPUS or PEMF treatments. At one, two, three and four weeks follow-up explants were prepared for histological assessment or gene expression (porcine only). Non-treated porcine explants showed signs of atrophy of the superficial zone starting at one week. Treated explants did not. In LIPUS-treated explants cell clusters were observed. In PEMF-treated explants more hypertrophic-like changes were observed at later follow up. Newly synthesized tissue was present in treated explants. Gene expression profiles did indicate differences between the two methods. Both methods reduced expression of the aggrecan and collagen type II gene compared to the control. LIPUS treatment of human cartilage samples resulted in a reduction of degeneration according to Mankin scoring. PEMF treatment did not. LIPUS or PEMF prevented degenerative changes in pig knee cartilage explants. LIPUS reduced degeneration in human cartilage samples. LIPUS treatment seems to have more potency in the treatment of osteoarthritis than PEMF treatment.

  18. A preliminary study into the effect of low-intensity pulsed ultrasound on chronic maxillary and frontal sinusitis.

    PubMed

    Ansari, Noureddin Nakhostin; Naghdi, Soofia; Farhadi, Mohammad; Jalaie, Shohreh

    2007-01-01

    Sinusitis is a very common acute or chronic illness that affects a significant percentage of individuals. Recently, therapeutic ultrasound was reported as a treatment for chronic sinusitis. The purpose of this study was twofold: 1) to evaluate the effectiveness of low-intensity pulsed ultrasound (US) in chronic sinusitis using a pretest-posttest research design and 2) to determine the level of association between the independent variables of initial presence of symptoms, age, gender, and duration of disease and the dependent variable of improvement of symptoms. Patients with chronic sinusitis were treated with low-intensity pulsed US, 3 days per week for 15 sessions. Fifty-seven patients (18 females and 39 males; mean age, 35 years) were included in the study. The results of the McNemar test showed a significant change in proportions of post nasal drip and nasal obstruction, two common leading symptoms of patients with chronic sinusitis (p < 0.001). Most of the major and minor symptoms showed significant changes after US therapy (p < 0.05). The total improvement of symptoms was 81.3%. The greatest improvement in symptoms was observed in nasal discharge (100%), followed by facial pain (95.4%) and postnasal drip (82.7%), three major factors in sinusitis. There was a significant, low association between the initial presence of symptoms and the improvement of symptoms after US therapy (chi(2) = 30.352; df = 12; p = 0.002; phi value = 0.356). A significant, low association was also noted between the age and the improvement of symptoms after intervention (chi(2) = 17.548; df = 6; p = 0.007; phi value = 0.270). It may be concluded that low-intensity pulsed US has a significant effect on chronic sinusitis and improves patient symptoms in our study group.

  19. Low intensity pulsed ultrasound increases the mechanical properties of the healing tissues at bone-tendon junction.

    PubMed

    Lu, Min-Hua; Zheng, Yong-Ping; Huang, Qing-Hua; Lu, Hong-Bin; Qin, Ling

    2009-01-01

    The re-establishment of bone-tendon junction (BTJ) tissues is involved in many trauma and reconstructive surgeries. A direct BTJ repair requires a long period of immobilization which may be associated with a postoperative weak knee. In this study, we investigated if low-intensity pulsed ultrasound treatment increases the material properties of healing tissues at bone-tendon junction (BTJ) after partial patellectomy using rabbit models. Standard partial patellectomy was conducted on one knee of twenty four rabbits which were randomly divided into an ultrasound group and a control group. The bony changes of BTJ complexes around the BTJ healing interface were measured by anteroposterior x-ray radiographs; then the volumetric bone-mineral density (BMD) of the new bone was assessed using a peripheral computed tomography scanner (pQCT). The stiffness of patellar cartilage, fibrocartilage at the healing interface and the tendon were measured in situ using a novel noncontact ultrasound water jet indentation system. Not only significantly more newly formed bone at the BTJ healing interface but also increased stiffness of the junction tissues were found in the ultrasound group compared with the controls at week 18. In addition, the ultrasound group also showed significantly 44% higher BMD at week 6 than controls.

  20. The effects of low-intensity pulsed ultrasound on fresh fracture: A meta-analysis.

    PubMed

    Lou, Shenghan; Lv, Houchen; Li, Zhirui; Zhang, Licheng; Tang, Peifu

    2017-09-01

    Low-intensity pulsed ultrasonography (LIPUS) is a form of mechanical stimulation that is delivered via a special device to the fracture site for the acceleration of fracture healing. We conducted a meta-analysis to assess the effect of LIPUS for fresh fractures in adults. MEDLINE, EMBASE and the Cochrane Library searched between Jan 1980 and Nov 2016. Studies should be quasi-randomized and randomized controlled trials (RCTs) comparing treatment with LIPUS to placebo or no treatment in adults with fresh fractures, reporting outcomes such as function; time to union; delayed union or non-union. Summary standard mean difference (SMD) and the risk ratio (RR) with their 95% confidence interval (CI) calculated with a random effects model. I statistic was used to assess the heterogeneity. Risk of bias was assessed by the Cochrane risk-of-bias tool. The GRADE system was used to evaluate the evidence quality. A total of 12 trials with 1099 patients were included. The pooled results showed that LIPUS significantly reduced the time to fracture union (SMD: 0.65, 95% CI: 1.13 to 0.17), improved the quality of life (SMD: 0.20, 95% CI: 0.03-0.37) without affecting the time to full weight bearing (SMD: 0.76, 95% CI: 1.92 to 0.4), the time to return to work (SMD: 0.06, 95% CI: 0.14 to 0.27), or the incidence rate of delayed union and nonunion (RR: 1.02, 95% CI: 0.60-1.74). Moderate-to-high quality evidence shows that LIPUS treatment reduces the time to fracture union and improves the quality of life without affecting functional recovery and incident rate of delayed union and nonunion, suggesting that LIPUS treatment may be a good treatment modality for adults with fresh fractures. However, there are some methodological limitations in the eligible trials, further studies are needed to determine the clinical circumstances under which LIPUS is truly valid and to examine the optimal approach for the use of this adjunctive therapy.

  1. Low-intensity pulsed ultrasound (LIPUS) prevents periprosthetic inflammatory loosening through FBXL2-TRAF6 ubiquitination pathway.

    PubMed

    Zhao, Xiang; Zhao, Gangsheng; Shi, Zhongli; Zhou, Chenhe; Chen, Yunlin; Hu, Bin; Yan, Shigui

    2017-04-05

    Previous studies have shown that Low intensity pulsed ultrasound(LIPUS) prevents polyethylene-debris-induced periprosthetic loosening in vivo, but the details of the mechanism by which it does so remain unclear. In this article, we used polyethylene debris induced RAW 264.7 cells as the in vitro model, and tested the effect of LIPUS on this model. Changes in the level of inflammatory cytokines, cell proliferation, and apoptosis were assessed. Gene overexpression and siRNA technique were applied, and the levels of expression of FBXL2, TRAF6, ERK, and related inflammatory cytokines were also measured. Results indicated that FBXL2-mediated TRAF6 ubiquitination and degradation also plays an important role in aseptic periprosthetic loosening process, and LIPUS prevents such loosening by strengthening this pathway.

  2. Low-intensity pulsed ultrasound (LIPUS) prevents periprosthetic inflammatory loosening through FBXL2-TRAF6 ubiquitination pathway

    PubMed Central

    Zhao, Xiang; Zhao, Gangsheng; Shi, Zhongli; Zhou, Chenhe; Chen, Yunlin; Hu, Bin; Yan, Shigui

    2017-01-01

    Previous studies have shown that Low intensity pulsed ultrasound(LIPUS) prevents polyethylene-debris-induced periprosthetic loosening in vivo, but the details of the mechanism by which it does so remain unclear. In this article, we used polyethylene debris induced RAW 264.7 cells as the in vitro model, and tested the effect of LIPUS on this model. Changes in the level of inflammatory cytokines, cell proliferation, and apoptosis were assessed. Gene overexpression and siRNA technique were applied, and the levels of expression of FBXL2, TRAF6, ERK, and related inflammatory cytokines were also measured. Results indicated that FBXL2-mediated TRAF6 ubiquitination and degradation also plays an important role in aseptic periprosthetic loosening process, and LIPUS prevents such loosening by strengthening this pathway. PMID:28378753

  3. Bone regeneration by low-level laser therapy and low-intensity pulsed ultrasound therapy in the rabbit calvarium.

    PubMed

    Acar, Ahmet Hüseyin; Yolcu, Ümit; Altındiş, Sedat; Gül, Mehmet; Alan, Hilal; Malkoç, Sıddık

    2016-01-01

    We evaluated the efficacy of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS), alone and in combination, in triggering new bone formation. Sixteen New Zealand white rabbits were given two calvarial defects by using a 6-mm trephine bur, then divided into four treatment groups: control, LLLT, LIPUS, and LLLT+LIPUS. The LLLT and LIPUS groups were treated three times a week for two weeks. The LLLT+LIPUS group received each treatment on the same day, 12h apart, three days a week for two weeks. The animals were sacrificed after three weeks. LLLT and LIPUS, alone and in combination, enhanced new bone formation in comparison to the untreated controls after three weeks (P<0.05); the combined therapy did not produce an additive effect. Our results demonstrate the efficacy of LLLT or LIPUS in triggering bone regeneration. Therapeutic dose and duration requires further study. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effects and Mechanisms of Low-Intensity Pulsed Ultrasound for Chronic Prostatitis and Chronic Pelvic Pain Syndrome.

    PubMed

    Lin, Guiting; Reed-Maldonado, Amanda B; Lin, Maofan; Xin, Zhongcheng; Lue, Tom F

    2016-07-01

    Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is one of the most common urologic diseases, and no curative treatments have been identified. Low-intensity pulsed ultrasound (LIPUS) has been successfully used in promoting tissue healing, inhibiting inflammation and pain, differentiating stem cells, and stimulating nerve regeneration/muscle regeneration, as well as enhancing angiogenesis. Very recently, LIPUS has been proven an effective approach for CP/CPPS. This review summarizes the possible mechanisms responsible for the therapeutic effect of LIPUS for CP/CPPS. To search publications relevant to the topics of this review, the search engine for life sciences of Entrez was used. We reviewed the available evidence from 1954 through 2015 concerning LIPUS for CP/CPPS. According to the literature, both transrectal and transperineal approaches of LIPUS are effective for CP/CPPS.

  5. Effects and Mechanisms of Low-Intensity Pulsed Ultrasound for Chronic Prostatitis and Chronic Pelvic Pain Syndrome

    PubMed Central

    Lin, Guiting; Reed-Maldonado, Amanda B.; Lin, Maofan; Xin, Zhongcheng; Lue, Tom F.

    2016-01-01

    Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) is one of the most common urologic diseases, and no curative treatments have been identified. Low-intensity pulsed ultrasound (LIPUS) has been successfully used in promoting tissue healing, inhibiting inflammation and pain, differentiating stem cells, and stimulating nerve regeneration/muscle regeneration, as well as enhancing angiogenesis. Very recently, LIPUS has been proven an effective approach for CP/CPPS. This review summarizes the possible mechanisms responsible for the therapeutic effect of LIPUS for CP/CPPS. To search publications relevant to the topics of this review, the search engine for life sciences of Entrez was used. We reviewed the available evidence from 1954 through 2015 concerning LIPUS for CP/CPPS. According to the literature, both transrectal and transperineal approaches of LIPUS are effective for CP/CPPS. PMID:27376284

  6. Osteogenic activity of human fracture haematoma-derived progenitor cells is stimulated by low-intensity pulsed ultrasound in vitro.

    PubMed

    Hasegawa, T; Miwa, M; Sakai, Y; Niikura, T; Kurosaka, M; Komori, T

    2009-02-01

    The haematoma occurring at the site of a fracture is known to play an important role in bone healing. We have recently shown the presence of progenitor cells in human fracture haematoma and demonstrated that they have the capacity for multilineage mesenchymal differentiation. There have been many studies which have shown that low-intensity pulsed ultrasound (LIPUS) stimulates the differentiation of a variety of cells, but none has investigated the effects of LIPUS on cells derived from human fracture tissue including human fracture haematoma-derived progenitor cells (HCs). In this in vitro study, we investigated the effects of LIPUS on the osteogenic activity of HCs. Alkaline phosphatase activity, osteocalcin secretion, the expression of osteoblast-related genes and the mineralisation of HCs were shown to be significantly higher when LIPUS had been applied but without a change in the proliferation of the HCs. These findings provide evidence in favour of the use of LIPUS in the treatment of fractures.

  7. Lipid Coated Microbubbles and Low Intensity Pulsed Ultrasound Enhance Chondrogenesis of Human Mesenchymal Stem Cells in 3D Printed Scaffolds

    PubMed Central

    Aliabouzar, Mitra; Zhang, Lijie Grace; Sarkar, Kausik

    2016-01-01

    Lipid-coated microbubbles are used to enhance ultrasound imaging and drug delivery. Here we apply these microbubbles along with low intensity pulsed ultrasound (LIPUS) for the first time to enhance proliferation and chondrogenic differentiation of human mesenchymal stem cells (hMSCs) in a 3D printed poly-(ethylene glycol)-diacrylate (PEG-DA) hydrogel scaffold. The hMSC proliferation increased up to 40% after 5 days of culture in the presence of 0.5% (v/v) microbubbles and LIPUS in contrast to 18% with LIPUS alone. We systematically varied the acoustic excitation parameters—excitation intensity, frequency and duty cycle—to find 30 mW/cm2, 1.5 MHz and 20% duty cycle to be optimal for hMSC proliferation. A 3-week chondrogenic differentiation results demonstrated that combining LIPUS with microbubbles enhanced glycosaminoglycan (GAG) production by 17% (5% with LIPUS alone), and type II collagen production by 78% (44% by LIPUS alone). Therefore, integrating LIPUS and microbubbles appears to be a promising strategy for enhanced hMSC growth and chondrogenic differentiation, which are critical components for cartilage regeneration. The results offer possibilities of novel applications of microbubbles, already clinically approved for contrast enhanced ultrasound imaging, in tissue engineering. PMID:27883051

  8. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation

    PubMed Central

    Zhou, Xuan; Castro, Nathan J.; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm2 intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  9. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-09-06

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application.

  10. Controllable permeability of blood-brain barrier and reduced brain injury through low-intensity pulsed ultrasound stimulation.

    PubMed

    Su, Wei-Shen; Tsai, Min-Lan; Huang, Sin-Luo; Liu, Shing-Hwa; Yang, Feng-Yi

    2015-12-08

    It has been shown that the blood-brain barrier (BBB) can be locally disrupted by focused ultrasound (FUS) in the presence of microbubbles (MB) while sustaining little damage to the brain tissue. Thus, the safety issue associated with FUS-induced BBB disruption (BBBD) needs to be investigated for future clinical applications. This study demonstrated the neuroprotective effects induced by low-intensity pulsed ultrasound (LIPUS) against brain injury in the sonicated brain. Rats subjected to a BBB disruption injury received LIPUS exposure for 5 min after FUS/MB application. Measurements of BBB permeability, brain water content, and histological analysis were then carried out to evaluate the effects of LIPUS. The permeability and time window of FUS-induced BBBD can be effectively modulated with LIPUS. LIPUS also significantly reduced brain edema, neuronal death, and apoptosis in the sonicated brain. Our results show that brain injury in the FUS-induced BBBD model could be ameliorated by LIPUS and that LIPUS may be proposed as a novel treatment modality for controllable release of drugs into the brain.

  11. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold.

  12. [Research on ultrasonic permeability of low intensity pulsed ultrasound through PTFE membrane and Bio-Gide collagen membrane].

    PubMed

    Chai, Zhaowu; Zhao, Chunliang; Song, Jinlin; Deng, Feng; Yang, Ji; Gao, Xiang; Liu, Minyi

    2013-12-01

    The aim of the present study was to detect the transmission rate of ultrasonic low intensity pulsed ultrasound (LIPUS) through polytetrafluoroethylene (PTFE) membrane (Thickness: 0.01 mm) and Bio-Gide collagen membrane, and to provide the basis for the barrier membrane selection on the study of LIPUS combined with guided tissue regeneration (GTR). The ultrasonic (LIPUS, frequency 1.5 MHz, pulse width 200 micros, repetition rate 1.0 kHz) transmission coefficient of the two kinds of barrier membrane were detected respectively through setting ten groups from 10 to 100mW/cm2 every other 10 mW/cm2. We found in the study that the ultrasonic transmission coefficient through 0.01 mm PTFE membrane was 78.1% to 92.%, and the ultrasonic transmission coefficient through Bio-Gide collagen membrane was 43.9% to 55.8%. The ultrasonic transmission coefficient through PTFE membrane was obviously higher than that through Bio-Gide collagen membrane. The transmission coefficient of the same barrier membrane of the ultrasonic ion was statistically different under different powers (P < 0.05). The results showed that the ultrasonic transmittance rates through both the 0.01 mm PTFE membrane and Bio-Gide collagen membrane were relatively high. We should select barrier membranes based on different experimental needs, and exercise ultrasonic transmission coefficient experiments to ensure effective power.

  13. Using low-intensity pulsed ultrasound to improve muscle healing after laceration injury: an in vitro and in vivo study.

    PubMed

    Chan, Yi-Sheng; Hsu, Kuo-Yao; Kuo, Chia-Hua; Lee, Shin-Da; Chen, Su-Ching; Chen, Wen-Jer; Ueng, Steve Wen-Neng

    2010-05-01

    The purpose of this study was to determine whether low-intensity pulsed ultrasound (LIPUS) could enhance the regeneration of myofibers and shorten the healing time in injured muscle. NIH C2C12 cells, a well-known myoblastic cell line, are subclones derived from the mouse myoblast cell line established from normal adult C3H mouse leg muscle. The cells differentiate rapidly and produce extensive contracting myotubes expressing characteristic muscle proteins. We exposed C2C12 cells to LIPUS therapy using the EXOGEN 2000+ system ultrasound apparatus (Exogen Inc., Piscataway, NJ, USA) with a total treatment of 20 min every 24 h. At intervals of 2, 4, 6 and 8 days, cell growth was measured by the increase in cell number and western blot analysis of myogenin and actin. Forty mice (C57BL10J+/+) were divided into five groups of eight animals each and used in the published laceration injury model. The gastrocnemius muscle of the left leg was lacerated in all the animals. The control group (sham ultrasound) did not undergo LIPUS therapy. The ultrasound 7-, 14-, 21- and 28-day groups (only changing the number of days during which the ultrasound was applied to the injured muscle) were treated with LIPUS (20 min/day) for 7, 14, 21 and 28 consecutive days, respectively. All animals were sacrificed at 4 weeks after the injury. Evaluation methods included muscle regeneration and muscle contractile properties. LIPUS therapy produced a significantly higher proliferative rate and cell number at days 6 and 8 (p < 0.05). Densitometric evaluation revealed an increase in myogenin and actin proteins in cells treated with LIPUS in the 4-, 6- and 8-day groups. The regeneration of myofibers, fast-twitch and tetanus of LIPUS-treated muscles (21 and 28 days) was significantly greater relative to control muscles. There was no major strength difference between the normal non-injured muscle and the group treated with LIPUS for 28 days. In conclusion, this was the first experimental study to show

  14. Effects of Low-intensity Pulsed Ultrasound and Cryotherapy on Recovery of Joint Function and C-reactive Protein Levels in Patients after Total Knee Replacement Surgery

    PubMed Central

    Kang, Jeong Il; Kim, Yong-Nam; Choi, Hyun

    2014-01-01

    [Purpose] We investigated the effect of low-intensity pulsed ultrasound and cryotherapy on joint function recovery and C-reactive protein (CRP) levels of patients with total knee replacement. [Subjects] Forty-six patients with total knee replacement were recruited and allocated to either low-intensity pulsed ultrasound therapy (n=15), cryotherapy (n=15), or a combination of both (n=16). Therapy was administered once a day, 5 times a week for 3 weeks. To determine functional joint recovery and reduction of inflammation, changes in the Korean Western Ontario and McMaster Universities Arthritis Index (K-WOMAC), range of motion (ROM), and CRP were assessed postsurgically and four times over a 3-week period. Using one-way analysis of variance (ANOVA), homogeneity tests were performed based on participants’ general characteristics. To recognize changes in time-variant K-WOMAC, ROM, and CRP values between groups, repeated measures ANOVA was performed, and Tukey’s test was used for post-test analysis. Values at α=0.05 were considered significant. [Results] We found a difference between groups and times, and the group that received the combined therapies showed greater changes in outcomes than the group that received low-intensity pulsed ultrasound therapy alone. [Conclusion] Applying both low-intensity pulsed ultrasound and cryotherapy can relieve inflammation and enhance joint function in patients who undergo total knee replacement. PMID:25140090

  15. The effects of low-intensity pulsed ultrasound on tendon-bone healing in a transosseous-equivalent sheep rotator cuff model.

    PubMed

    Lovric, Vedran; Ledger, Michael; Goldberg, Jerome; Harper, Wade; Bertollo, Nicky; Pelletier, Matthew H; Oliver, Rema A; Yu, Yan; Walsh, William R

    2013-02-01

    The purpose of this study was to examine the effects Low-intensity Pulsed Ultrasound has on initial tendon-bone healing in a clinically relevant extra-articular transosseous-equivalent ovine rotator cuff model. Eight skeletally mature wethers, randomly allocated to either control group (n = 4) or treatment group (n = 4), underwent rotator cuff surgery following injury to the infraspinatus tendon. All animals were killed 28 days post surgery to allow examination of early effects of Low-intensity Pulsed Ultrasound treatment. General improvement in histological appearance of tendon-bone integration was noted in the treatment group. Newly formed woven bone with increased osteoblast activity along the bone surface was evident. A continuum was observed between the tendon and bone in an interdigitated fashion with Sharpey's fibres noted in the treatment group. Low-intensity Pulsed Ultrasound treatment also increased bone mineral density at the tendon-bone interface (p < 0.01), while immunohistochemistry results revealed an increase in the protein expression patterns of VEGF (p = 0.038), RUNX2 (p = 0.02) and Smad4 (p = 0.05). The results of this study indicate that Low-intensity Pulsed Ultrasound may aid in the initial phase of tendon-bone healing process in patients who have undergone rotator cuff repair. This treatment may also be beneficial following other types of reconstructive surgeries involving the tendon-bone interface.

  16. Protective effects of low-intensity pulsed ultrasound on aluminum-induced cerebral damage in Alzheimer's disease rat model

    NASA Astrophysics Data System (ADS)

    Lin, Wei-Ting; Chen, Ran-Chou; Lu, Wen-Wei; Liu, Shing-Hwa; Yang, Feng-Yi

    2015-04-01

    The protein expressions of neurotrophic factors can be enhanced by low-intensity pulsed ultrasound (LIPUS) stimulation in the brain. The purpose of this study was to demonstrate the protective effect of LIPUS stimulation against aluminum-induced cerebral damage in Alzheimer's disease rat model. LIPUS was administered 7 days before each aluminum chloride (AlCl3) administration, and concomitantly given with AlCl3 daily for a period of 6 weeks. Neurotrophic factors in hippocampus were measured by western blot analysis. Behavioral changes in the Morris water maze and elevated plus maze were examined in rats after administration of AlCl3. Various biochemical analyses were performed to evaluate the extent of brain damages. LIPUS is capable of prompting levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and vascular endothelial growth factor (VEGF) in rat brain. AlCl3 administration resulted in a significant increase in the aluminum concentration, acetylcholinesterase activity and beta-amyloid (Aβ) deposition in AlCl3 treated rats. LIPUS stimulation significantly attenuated aluminum concentration, acetylcholinesterase activity, Aβ deposition and karyopyknosis in AlCl3 treated rats. Furthermore, LIPUS significantly improved memory retention in AlCl3-induced memory impairment. These experimental results indicate that LIPUS has neuroprotective effects against AlCl3-induced cerebral damages and cognitive dysfunction.

  17. Low-intensity pulsed ultrasound (LIPUS) and cell-to-cell communication in bone marrow stromal cells.

    PubMed

    Sena, Kotaro; Angle, Siddhesh R; Kanaji, Arihiko; Aher, Chetan; Karwo, David G; Sumner, Dale R; Virdi, Amarjit S

    2011-07-01

    Low-intensity pulsed ultrasound (LIPUS) is an established therapy for fracture repair and has been used widely in the clinics, but its underlying mechanism of action remains unclear. The aim of the current research was to determine the effect of LIPUS on gap junctional cell-to-cell intercellular communication in rat bone marrow stromal cells (BMSC) in vitro and to determine whether the ability of BMSCs to communicate by gap junctions would affect their response to LIPUS. Single or daily-multiple LIPUS treatment at 1.5MHz, 30mW/cm(2), for 20min was applied to BMSC. We demonstrated that BMSC form functional gap junctions and single LIPUS treatment significantly increased the intracellular dye transfer between BMSC. In addition, activated phosphorylation of ERK1/2 and p38 by LIPUS stimulation was diminished when cells were treated with a gap junction inhibitor 18β-glycyrrhetinic acid (18β). We further demonstrated that 18β diminished the significant increase in alkaline phosphatase activity following LIPUS stimulation. These results suggest a potential role of gap junctional cell-to-cell intercellular communication on the effects of LIPUS in BMSC.

  18. Enhancement of Neurotrophic Factors in Astrocyte for Neuroprotective Effects in Brain Disorders Using Low-intensity Pulsed Ultrasound Stimulation.

    PubMed

    Yang, Feng-Yi; Lu, Wen-Wei; Lin, Wei-Ting; Chang, Chi-Wei; Huang, Sin-Luo

    2015-01-01

    Astrocytes play an important role in the growth and survival of developing neurons by secreting neurotrophic factors. The goal of this study was to investigate how low-intensity pulsed ultrasound (LIPUS) stimulation directly affects brain astrocyte function. Here, we report that LIPUS stimulation increased protein levels of BDNF, GDNF, VEGF, and GLUT1 in rat brain astrocytes as measured by western blot analysis. Histological outcomes including demyelination and apoptosis were examined in rats after administration of aluminum chloride (AlCl3). At the mechanistic level, integrin inhibitor (RGD peptide) attenuated the LIPUS-induced neurotrophic factor expression. The data suggest that neurotrophic factor protein levels may be promoted by LIPUS through activation of integrin receptor signaling. In addition, LIPUS stimulation protected cells against aluminum toxicity as demonstrated by an increase in the median lethal dose for AlCl3 from 3.77 to 6.25 mM. In in vivo histological evaluations, LIPUS significantly reduced cerebral damages in terms of myelin loss and apoptosis induced by AlCl3. The results of this study demonstrate that transcranial LIPUS is capable of enhancing the protein levels of neurotrophic factors, which could have neuroprotective effects against neurodegenerative diseases. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Protective effects of low-intensity pulsed ultrasound on aluminum-induced cerebral damage in Alzheimer's disease rat model

    PubMed Central

    Lin, Wei-Ting; Chen, Ran-Chou; Lu, Wen-Wei; Liu, Shing-Hwa; Yang, Feng-Yi

    2015-01-01

    The protein expressions of neurotrophic factors can be enhanced by low-intensity pulsed ultrasound (LIPUS) stimulation in the brain. The purpose of this study was to demonstrate the protective effect of LIPUS stimulation against aluminum-induced cerebral damage in Alzheimer's disease rat model. LIPUS was administered 7 days before each aluminum chloride (AlCl3) administration, and concomitantly given with AlCl3 daily for a period of 6 weeks. Neurotrophic factors in hippocampus were measured by western blot analysis. Behavioral changes in the Morris water maze and elevated plus maze were examined in rats after administration of AlCl3. Various biochemical analyses were performed to evaluate the extent of brain damages. LIPUS is capable of prompting levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and vascular endothelial growth factor (VEGF) in rat brain. AlCl3 administration resulted in a significant increase in the aluminum concentration, acetylcholinesterase activity and beta-amyloid (Aβ) deposition in AlCl3 treated rats. LIPUS stimulation significantly attenuated aluminum concentration, acetylcholinesterase activity, Aβ deposition and karyopyknosis in AlCl3 treated rats. Furthermore, LIPUS significantly improved memory retention in AlCl3-induced memory impairment. These experimental results indicate that LIPUS has neuroprotective effects against AlCl3-induced cerebral damages and cognitive dysfunction. PMID:25873429

  20. Effect of low-intensity pulsed ultrasound on biocompatibility and cellular uptake of chitosan-tripolyphosphate nanoparticles

    PubMed Central

    Wu, Junyi; Liu, Gaojun; Qin, Yi-Xian; Meng, Yizhi

    2014-01-01

    Using low molecular weight chitosan nanoparticles (CNPs) prepared by an ionic gelation method, the authors report the effect of low-intensity pulsed ultrasound (US) on cell viability and nanoparticle uptake in cultured murine preosteoblasts. Particle size and zeta potential are measured using dynamic light scattering, and cell viability is evaluated using the of [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt; MTS] assay. Results show that 30 min delivery of CNPs at 0.5 mg/mL is able to prevent loss of cell viability due to either serum starvation or subsequent exposure to US (1 W/cm2 or 2 W/cm2, up to 1 min). Additionally, flow cytometry data suggest that there is a close association between cellular membrane integrity and the presence of CNPs when US at 2 W/cm2 is administered. PMID:25280857

  1. Protective effects of low-intensity pulsed ultrasound on aluminum-induced cerebral damage in Alzheimer's disease rat model.

    PubMed

    Lin, Wei-Ting; Chen, Ran-Chou; Lu, Wen-Wei; Liu, Shing-Hwa; Yang, Feng-Yi

    2015-04-15

    The protein expressions of neurotrophic factors can be enhanced by low-intensity pulsed ultrasound (LIPUS) stimulation in the brain. The purpose of this study was to demonstrate the protective effect of LIPUS stimulation against aluminum-induced cerebral damage in Alzheimer's disease rat model. LIPUS was administered 7 days before each aluminum chloride (AlCl3) administration, and concomitantly given with AlCl3 daily for a period of 6 weeks. Neurotrophic factors in hippocampus were measured by western blot analysis. Behavioral changes in the Morris water maze and elevated plus maze were examined in rats after administration of AlCl3. Various biochemical analyses were performed to evaluate the extent of brain damages. LIPUS is capable of prompting levels of brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), and vascular endothelial growth factor (VEGF) in rat brain. AlCl3 administration resulted in a significant increase in the aluminum concentration, acetylcholinesterase activity and beta-amyloid (Aβ) deposition in AlCl3 treated rats. LIPUS stimulation significantly attenuated aluminum concentration, acetylcholinesterase activity, Aβ deposition and karyopyknosis in AlCl3 treated rats. Furthermore, LIPUS significantly improved memory retention in AlCl3-induced memory impairment. These experimental results indicate that LIPUS has neuroprotective effects against AlCl3-induced cerebral damages and cognitive dysfunction.

  2. Genes Responsive to Low-Intensity Pulsed Ultrasound in MC3T3-E1 Preosteoblast Cells

    PubMed Central

    Tabuchi, Yoshiaki; Sugahara, Yuuki; Ikegame, Mika; Suzuki, Nobuo; Kitamura, Kei-ichiro; Kondo, Takashi

    2013-01-01

    Although low-intensity pulsed ultrasound (LIPUS) has been shown to enhance bone fracture healing, the underlying mechanism of LIPUS remains to be fully elucidated. Here, to better understand the molecular mechanism underlying cellular responses to LIPUS, we investigated gene expression profiles in mouse MC3T3-E1 preosteoblast cells exposed to LIPUS using high-density oligonucleotide microarrays and computational gene expression analysis tools. Although treatment of the cells with a single 20-min LIPUS (1.5 MHz, 30 mW/cm2) did not affect the cell growth or alkaline phosphatase activity, the treatment significantly increased the mRNA level of Bglap. Microarray analysis demonstrated that 38 genes were upregulated and 37 genes were downregulated by 1.5-fold or more in the cells at 24-h post-treatment. Ingenuity pathway analysis demonstrated that the gene network U (up) contained many upregulated genes that were mainly associated with bone morphology in the category of biological functions of skeletal and muscular system development and function. Moreover, the biological function of the gene network D (down), which contained downregulated genes, was associated with gene expression, the cell cycle and connective tissue development and function. These results should help to further clarify the molecular basis of the mechanisms of the LIPUS response in osteoblast cells. PMID:24252911

  3. Effects of low-intensity pulsed ultrasound on new trabecular bone during bone-tendon junction healing in a rabbit model: a synchrotron radiation micro-CT study.

    PubMed

    Lu, Hongbin; Zheng, Cheng; Wang, Zhanwen; Chen, Can; Chen, Huabin; Hu, Jianzhong

    2015-01-01

    This study was designed to evaluate the effects of low-intensity pulsed ultrasound on bone regeneration during the bone-tendon junction healing process and to explore the application of synchrotron radiation micro computed tomography in three dimensional visualization of the bone-tendon junction to evaluate the microarchitecture of new trabecular bone. Twenty four mature New Zealand rabbits underwent partial patellectomy to establish a bone-tendon junction injury model at the patella-patellar tendon complex. Animals were then divided into low-intensity pulsed ultrasound treatment (20 min/day, 7 times/week) and placebo control groups, and were euthanized at week 8 and 16 postoperatively (n = 6 for each group and time point). The patella-patellar tendon specimens were harvested for radiographic, histological and synchrotron radiation micro computed tomography detection. The area of the newly formed bone in the ultrasound group was significantly greater than that of control group at postoperative week 8 and 16. The high resolution three dimensional visualization images of the bone-tendon junction were acquired by synchrotron radiation micro computed tomography. Low-intensity pulsed ultrasound treatment promoted dense and irregular woven bone formation at week 8 with greater bone volume fraction, number and thickness of new trabecular bone but with lower separation. At week 16, ultrasound group specimens contained mature lamellar bone with higher bone volume fraction and thicker trabeculae than that of control group; however, there was no significant difference in separation and number of the new trabecular bone. This study confirms that low-intensity pulsed ultrasound treatment is able to promote bone formation and remodeling of new trabecular bone during the bone-tendon junction healing process in a rabbit model, and the synchrotron radiation micro computed tomography could be applied for three dimensional visualization to quantitatively evaluate the

  4. Low-Intensity Pulsed Ultrasound Enhances Angiogenesis and Ameliorates Left Ventricular Dysfunction in a Mouse Model of Acute Myocardial Infarction.

    PubMed

    Shindo, Tomohiko; Ito, Kenta; Ogata, Tsuyoshi; Hatanaka, Kazuaki; Kurosawa, Ryo; Eguchi, Kumiko; Kagaya, Yuta; Hanawa, Kenichiro; Aizawa, Kentaro; Shiroto, Takashi; Kasukabe, Sachie; Miyata, Satoshi; Taki, Hirofumi; Hasegawa, Hideyuki; Kanai, Hiroshi; Shimokawa, Hiroaki

    2016-06-01

    Left ventricular (LV) remodeling after acute myocardial infarction still remains an important issue in cardiovascular medicine. We have recently demonstrated that low-intensity pulsed ultrasound (LIPUS) therapy improves myocardial ischemia in a pig model of chronic myocardial ischemia through enhanced myocardial angiogenesis. In the present study, we aimed to demonstrate whether LIPUS also ameliorates LV remodeling after acute myocardial infarction and if so, to elucidate the underlying molecular mechanisms involved in the beneficial effects of LIPUS. We examined the effects of LIPUS on LV remodeling in a mouse model of acute myocardial infarction, where the heart was treated with either LIPUS or no-LIPUS 3 times in the first week (days 1, 3, and 5). The LIPUS improved mortality and ameliorated post-myocardial infarction LV remodeling in mice. The LIPUS upregulated the expression of vascular endothelial growth factor, endothelial nitric oxide synthase, phosphorylated ERK, and phosphorylated Akt in the infarcted area early after acute myocardial infarction, leading to enhanced angiogenesis. Microarray analysis in cultured human endothelial cells showed that a total of 1050 genes, including those of the vascular endothelial growth factor signaling and focal adhesion pathways, were significantly altered by the LIPUS. Knockdown with small interfering RNA of either β1-integrin or caveolin-1, both of which are known to play key roles in mechanotransduction, suppressed the LIPUS-induced upregulation of vascular endothelial growth factor. Finally, in caveolin-1-deficient mice, the beneficial effects of LIPUS on mortality and post-myocardial infarction LV remodeling were absent. These results indicate that the LIPUS therapy ameliorates post-myocardial infarction LV remodeling in mice in vivo, for which mechanotransduction and its downstream pathways may be involved. © 2016 American Heart Association, Inc.

  5. Effect of low-intensity pulsed ultrasound on osteogenic human mesenchymal stem cells commitment in a new bone scaffold.

    PubMed

    Carina, Valeria; Costa, Viviana; Raimondi, Lavinia; Pagani, Stefania; Sartori, Maria; Figallo, Elisa; Setti, Stefania; Alessandro, Riccardo; Fini, Milena; Giavaresi, Gianluca

    2017-07-27

    Bone tissue engineering is helpful in finding alternatives to overcome surgery limitations. Bone growth and repair are under the control of biochemical and mechanical signals; therefore, in recent years several approaches to improve bone regeneration have been evaluated. Osteo-inductive biomaterials, stem cells, specific growth factors and biophysical stimuli are among those. The aim of the present study was to evaluate if low-intensity pulsed ultrasound stimulation (LIPUS) treatment would improve the colonization of an MgHA/Coll hybrid composite scaffold by human mesenchymal stem cells (hMSCs) and their osteogenic differentiation. LIPUS stimulation was applied to hMSCs cultured on MgHA/Coll hybrid composite scaffold in osteogenic medium, mimicking the microenvironment of a bone fracture. hMSCs were seeded on MgHA/Coll hybrid composite scaffold in an osteo-inductive medium and exposed to LIPUS treatment for 20 min/day for different experimental times (7 days, 14 days). The investigation was focused on (i) the improvement of hMSCs to colonize the MgHA/Coll hybrid composite scaffold by LIPUS, in terms of cell viability and ultrastructural analysis; (ii) the activation of MAPK/ERK, osteogenic (ALPL,COL1A1,BGLAP,SPP1) and angiogenetic (VEGF, IL8) pathways, through gene expression and protein release analysis, after LIPUS stimuli. LIPUS exposure improved MgHA/Coll hybrid composite scaffold colonization and induced in vitro osteogenic differentiation of hMSCs seeded on the scaffold. This work shows that the combined use of new biomimetic osteo-inductive composite and LIPUS treatment could be a useful therapeutic approach in order to accelerate bone regeneration pathways.

  6. When Is a Fracture Not "Fresh"? Aligning Reimbursement With Patient Outcome After Treatment With Low-Intensity Pulsed Ultrasound.

    PubMed

    Zura, Robert; Xu, Zekun Jack; Della Rocca, Gregory J; Mehta, Samir; Steen, R Grant

    2017-05-01

    The clinical value of low-intensity pulsed ultrasound (LIPUS) for fresh fracture is known. Yet, in the absence of a definition of what "fresh" is, payers have adopted study inclusion criteria drawn from randomized clinical trials as de facto definitions of which patients should be treated, with "fresh" defined as <1 week old. Patients with fracture may thus be ineligible for LIPUS treatment after week 1, which potentially denies access to patients who could benefit from LIPUS. We seek to characterize the inflection point at which heal rate declines. Prospective cohort. Food and Drug Administration-mandated nationwide postmarketing surveillance registry. Observational cohort of 5983 registry enrollees. LIPUS, 20 min/d. Fracture heal rate. Logistic regression was used to model the odds ratio of nonunion from week 1 to week 12. Covariates in the model included age, gender, body mass index, open fracture, and smoking. We estimated the time point at which a fracture responds to LIPUS as well as during the first week after fracture. There was significant bone-to-bone variation; metatarsal was "fresh" until week 7, ankle until week 9, humerus until week 10, and femur and radius until week 12. Healing was significantly impacted by patient age, body mass index, and open fracture (all, P ≤ 0.02). Our results suggest that fractures of the metatarsal, femur, humerus, ankle, and radius respond to LIPUS treatment, as if they were still fresh at least 6 weeks longer than the eligibility allowed under current coverage policies. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

  7. Low-intensity pulsed ultrasound enhances angiogenesis and ameliorates contractile dysfunction of pressure-overloaded heart in mice.

    PubMed

    Ogata, Tsuyoshi; Ito, Kenta; Shindo, Tomohiko; Hatanaka, Kazuaki; Eguchi, Kumiko; Kurosawa, Ryo; Kagaya, Yuta; Monma, Yuto; Ichijo, Sadamitsu; Taki, Hirofumi; Kanai, Hiroshi; Shimokawa, Hiroaki

    2017-01-01

    Chronic left ventricular (LV) pressure overload causes relative ischemia with resultant LV dysfunction. We have recently demonstrated that low-intensity pulsed ultrasound (LIPUS) improves myocardial ischemia in a pig model of chronic myocardial ischemia through enhanced myocardial angiogenesis. In the present study, we thus examined whether LIPUS also ameliorates contractile dysfunction in LV pressure-overloaded hearts. Chronic LV pressure overload was induced with transverse aortic constriction (TAC) in mice. LIPUS was applied to the whole heart three times in the first week after TAC and was repeated once a week for 7 weeks thereafter (n = 22). Animals in the control groups received the sham treatment without LIPUS (n = 23). At 8 weeks after TAC, LV fractional shortening was depressed in the TAC-Control group, which was significantly ameliorated in the TAC-LIPUS group (30.4±0.5 vs. 36.2±3.8%, P<0.05). Capillary density was higher and perivascular fibrosis was less in the LV in the TAC-LIPUS group than in the TAC-Control group. Myocardial relative ischemia evaluated with hypoxyprobe was noted in the TAC-Control group, which was significantly attenuated in the TAC-LIPUS group. In the TAC-LIPUS group, as compared with the control group, mRNA expressions of BNP and collagen III were significantly lower (both P<0.05) and protein expressions of VEGF and eNOS were significantly up-regulated associated with Akt activation (all P<0.05). No adverse effect related to the LIPUS therapy was noted. These results indicate that the LIPUS therapy ameliorates contractile dysfunction in chronically pressure-overloaded hearts through enhanced myocardial angiogenesis and attenuated perivascular fibrosis. Thus, the LIPUS therapy may be a promising, non-invasive treatment for cardiac dysfunction due to chronic pressure overload.

  8. Low-intensity pulsed ultrasound enhances bone morphogenetic protein expression of human mandibular fracture haematoma-derived cells.

    PubMed

    Huang, W; Hasegawa, T; Imai, Y; Takeda, D; Akashi, M; Komori, T

    2015-07-01

    We previously demonstrated that human mandibular fracture haematoma-derived cells (MHCs) play an important role in mandibular fracture healing and that low-intensity pulsed ultrasound (LIPUS) accelerates this effect by stimulating various osteogenic cytokines. In the present study, we investigated how LIPUS affects the expression of bone morphogenetic proteins (BMPs), which are also known to have the ability to induce bone formation. MHCs were isolated from human mandibular fracture haematomas and the cells were divided into two groups: a LIPUS (+) group and a LIPUS (-) group, both of which were cultured in osteogenic medium. LIPUS was applied to the LIPUS (+) group 20 min a day for 4, 8, 14, and 20 days (1.5 MHz, 30 mW/cm(2)). Real-time PCR and immunofluorescence studies were carried out to determine the expression of BMP-2, 4, and 7. Compared to the LIPUS (-) group, gene expression levels were significantly increased in the LIPUS (+) group for BMP-2 on day 20 (67.38 ± 26.59 vs. 11.52 ± 3.42, P < 0.001), for BMP-4 on days 14 (45.12 ± 11.06 vs. 9.20 ± 2.88, P = 0.045) and 20 (40.96 ± 24.81 vs. 3.22 ± 1.53, P = 0.035), and for BMP-7 on day 8 (48.11 ± 35.36 vs. 7.03 ± 3.96, P = 0.034). These findings suggest that BMP-2, 4, and 7 may be mediated by LIPUS therapy during the bone repair process.

  9. A comparison of the low-level laser versus low intensity pulsed ultrasound on new bone formed through distraction osteogenesis.

    PubMed

    Kocyigit, Ismail Doruk; Coskunses, Fatih Mehmet; Pala, Elvan; Tugcu, Funda; Onder, Ercument; Mocan, Asriye

    2012-08-01

    To assess and compare the effects of low-intensity pulsed ultrasound stimulation (LIPUS) and low-level laser therapy (LLLT) on the bone mineral density (BMD) of bone formed through distraction osteogenesis (DO) using dual energy x-ray absorptiometry (DEXA). LIPUS and LLLT are noninvasive supporting treatment concepts used for wound healing. LIPUS has been used to accelerate bone healing through the therapeutic effect arising from piezoelectric and angiogenetic effects on cell membranes. LLLT known as "photobiomodulation" is used in the treatment of soft and hard tissue injuries. The study was conducted with 15 New Zealand rabbits randomly divided into three groups of 5 according to treatment, as follows: Group A: DO was performed with no further treatment; Group B: DO was performed followed by 30 mW/cm(2) LIPUS at 1 Mhz for 20 min/day during the distraction period; Group C: DO was performed followed by 25 mW/cm(2) LLLT at 650 nm for 10 min/day during the distraction period. DEXA was used to examine the treated areas prior to surgery and at 30 and 60 days postoperatively. In the control group, the mean BMD values at both 30 and 60 days postoperatively were below the baseline level, whereas they were above at the same time intervals in the LIPUS group. In the LLLT group, the mean BMD value at 30 days postoperatively was below the baseline level, whereas it was above the baseline level at 60 days postoperatively. LIPUS and LLLT applied during the distraction period accelerated the DO treatment.

  10. Reversal of the Detrimental Effects of Simulated Microgravity on Human Osteoblasts by Modified Low Intensity Pulsed Ultrasound

    PubMed Central

    Zia Uddin, Sardar M.; Hadjiargyrou, Michael; Cheng, Jiqi; Zhang, Shu; Hu, Minyi; Qin, Yi-Xian

    2013-01-01

    Microgravity (MG) is known to induce bone loss in astronauts during long duration spare mission due to lack of sufficient mechanical stimulation under microgravity. It has been demonstrated that mechanical signals are essential for maintain cell viability and motility, and possibly serve as a countermeasure to the catabolic effects of MG. The objective of this study was to examine the effects of high frequency acoustic wave signals on osteoblasts in a simulated microgravity (SMG) environment (created using 1D clinostat bioreactor) using a modified low intensity pulsed ultrasound (mLIPUS). Specifically, we evaluated the hypothesis that osteoblasts [human fetal osteoblastic (hFob) cell line] exposure to mLIPUS for 20 min per day at 30 mW/cm2 will significantly reduce the detrimental effects of SMG. Effects of SMG with mLIPUS were analyzed using the MTS assay for proliferation, Phalloidin for F-actin staining, Sirius red stain for collagen and Alizarin red for mineralization. Our data showed that osteoblast exposure to SMG results in significant decreases in proliferation (~ −38% and ~ −44% at day 4 and 6, respectively, p<0.01), collagen content (~ −22%, p<0.05) and mineralization (~ −37%, p < 0.05) and actin stress fibers. In contrast, mLIPUS stimulation in SMG condition significantly increases the rate of proliferation (~24% by day 6, p<0.05), collagen content (~52%, p < 0.05) and matrix mineralization (~25%, p<0.001) along with restoring formation of actin stress fibers in the SMG-exposed osteoblasts. These data suggest that the acoustic wave can potentially be used as a countermeasure for disuse osteopenia. PMID:23453382

  11. [Effect of low intensity pulsed ultrasound on expression of TGF-β1 and Smads during dentin injury and repair].

    PubMed

    Wang, Fei; Zuo, Jing; Li, Yueheng; Yang, Zhengyan; Luo, Jun

    2017-09-28

    To explore the effect of low intensity pulsed ultrasound (LIPUS) on TGF-β1/Smad 2, 3 signal pathway during the dentin injury and repair.
 Methods: Among 25 Sprague-Dawley rats, 5 rats served as a blank control group without treatment. The remaining 20 rats received modified caries preparation inbilateral maxillary first molars to establish a model of dentin-pulp injury and repair. The right maxillary first molars served as a LIPUS group, which received LIPUS irradiation (frequency: 1.5 MHz, pulse width: 200 μs, pulse repetition frequency: 1 kHz, spatial averaged temporal averaged intensity: 30 mW/cm2, 20 min/d), and the left maxillary first molars served as a cavity-prepared group, which received fake LIPUS irradiation. The rats were sacrificed at 1, 3, 5, 7 and 14 days after LIPUS irradiation. Immunohistochemical staining and Image-pro plus 6.0 were applied to detect the expression and distribution of transforming growth factor-beta1 (TGF-β1) and small mothers against decapentaplegic 2/3(Smad 2 and Smad 3).
 Results: Immunohistochemical staining showed that the expression of TGF-β1 and Smad 2, 3 were low innormal pulp, but they were increased in different degree after dentin injury. The result of image analysis showed that the expression of TGF-β1 in the cavity-prepared group gradually increased at the first day and peaked at day 5, and then it returned to normal level at day 14. However, the expression of TGF-β1 in the LIPUS group were significantly higher than that in the cavity-prepared group at day 3 and 5 (both P<0.05). The expressions of Smad 2,3 in both the LIPUS group and the cavity-prepared group were consistently increased all the way, but the expressions in the LIPUS group were higher compared with that in the cavity-prepared group (P<0.05).
 Conclusion: The TGF-β1/Smad 2, 3 signal pathway can be activated during the dentin injury and repair. LIPUS can up-regulate the expression of TGF-β1 and Smad 2, 3 in the early period, which may take

  12. Healing of fracture nonunions treated with low-intensity pulsed ultrasound (LIPUS): A systematic review and meta-analysis.

    PubMed

    Leighton, Ross; Watson, J Tracy; Giannoudis, Peter; Papakostidis, Costas; Harrison, Andrew; Steen, R Grant

    2017-07-01

    Bone fractures fail to heal and form nonunions in roughly 5% of cases, with little expectation of spontaneous healing thereafter. We present a systematic review and meta-analysis of published papers that describe nonunions treated with low-intensity pulsed ultrasound (LIPUS). Articles in PubMed, Ovid MEDLINE, CINAHL, AMED, EMBASE, Cochrane Library, and Scopus databases were searched, using an approach recommended by the Methodological Index for Non-Randomized Studies (MINORS), with a Level of Evidence rating by two reviewers independently. Studies are included here if they reported fractures older than 3 months, presented new data with a sample N≥12, and reported fracture outcome (Heal/Fail). Thirteen eligible papers reporting LIPUS treatment of 1441 nonunions were evaluated. The pooled estimate of effect size for heal rate was 82% (95% CI: 77-87%), for any anatomical site and fracture age of at least 3 months, with statistical heterogeneity detected across all primary studies (Q=41.2 (df=12), p<0.001, Tau(2)=0.006, I(2)=71). With a stricter definition of nonunion as fracture age of at least 8 months duration, the pooled estimate of effect size was 84% (95% CI: 77%-91.6%; heterogeneity present: Q=21 (df=8), p<0.001, Tau(2)=0.007, I(2)=62). Hypertrophic nonunions benefitted more than biologically inactive atrophic nonunions. An interval without surgery of <6months prior to LIPUS was associated with a more favorable result. Stratification of nonunions by anatomical site revealed no statistically significant differences between upper and lower extremity long bone nonunions. LIPUS treatment can be an alternative to surgery for established nonunions. Given that no spontaneous healing of established nonunions is expected, and that it is challenging to test the efficacy of LIPUS for nonunion by randomized clinical trial, findings are compelling. LIPUS may be most useful in patients for whom surgery is high risk, including elderly patients at risk of delirium, or

  13. Low Intensity Pulsed Ultrasound Enhanced Mesenchymal Stem Cell Recruitment through Stromal Derived Factor-1 Signaling in Fracture Healing

    PubMed Central

    Wei, Fang-Yuan; Leung, Kwok-Sui; Li, Gang; Qin, Jianghui; Chow, Simon Kwoon-Ho; Huang, Shuo; Sun, Ming-Hui; Qin, Ling; Cheung, Wing-Hoi

    2014-01-01

    Low intensity pulsed ultrasound (LIPUS) has been proven effective in promoting fracture healing but the underlying mechanisms are not fully depicted. We examined the effect of LIPUS on the recruitment of mesenchymal stem cells (MSCs) and the pivotal role of stromal cell-derived factor-1/C-X-C chemokine receptor type 4 (SDF-1/CXCR4) pathway in response to LIPUS stimulation, which are essential factors in bone fracture healing. For in vitro study, isolated rat MSCs were divided into control or LIPUS group. LIPUS treatment was given 20 minutes/day at 37°C for 3 days. Control group received sham LIPUS treatment. After treatment, intracellular CXCR4 mRNA, SDF-1 mRNA and secreted SDF-1 protein levels were quantified, and MSCs migration was evaluated with or without blocking SDF-1/CXCR4 pathway by AMD3100. For in vivo study, fractured 8-week-old young rats received intracardiac administration of MSCs were assigned to LIPUS treatment, LIPUS+AMD3100 treatment or vehicle control group. The migration of transplanted MSC to the fracture site was investigated by ex vivo fluorescent imaging. SDF-1 protein levels at fracture site and in serum were examined. Fracture healing parameters, including callus morphology, micro-architecture of the callus and biomechanical properties of the healing bone were investigated. The in vitro results showed that LIPUS upregulated SDF-1 and CXCR4 expressions in MSCs, and elevated SDF-1 protein level in the conditioned medium. MSCs migration was promoted by LIPUS and partially inhibited by AMD3100. In vivo study demonstrated that LIPUS promoted MSCs migration to the fracture site, which was associated with an increase of local and serum SDF-1 level, the changes in callus formation, and the improvement of callus microarchitecture and mechanical properties; whereas the blockade of SDF-1/CXCR4 signaling attenuated the LIPUS effects on the fractured bones. These results suggested SDF-1 mediated MSCs migration might be one of the crucial mechanisms

  14. Re-evaluation of low intensity pulsed ultrasound in treatment of tibial fractures (TRUST): randomized clinical trial

    PubMed Central

    Bhandari, Mohit; Einhorn, Thomas A; Schemitsch, Emil; Heckman, James D; Tornetta, Paul; Leung, Kwok-Sui; Heels-Ansdell, Diane; Makosso-Kallyth, Sun; Della Rocca, Gregory J; Jones, Clifford B; Guyatt, Gordon H

    2016-01-01

    Objective To determine whether low intensity pulsed ultrasound (LIPUS), compared with sham treatment, accelerates functional recovery and radiographic healing in patients with operatively managed tibial fractures. Design A concealed, randomized, blinded, sham controlled clinical trial with a parallel group design of 501 patients, enrolled between October 2008 and September 2012, and followed for one year. Setting 43 North American academic trauma centers. Participants Skeletally mature men or women with an open or closed tibial fracture amenable to intramedullary nail fixation. Exclusions comprised pilon fractures, tibial shaft fractures that extended into the joint and required reduction, pathological fractures, bilateral tibial fractures, segmental fractures, spiral fractures >7.5 cm in length, concomitant injuries that were likely to impair function for at least as long as the patient’s tibial fracture, and tibial fractures that showed <25% cortical contact and >1 cm gap after surgical fixation. 3105 consecutive patients who underwent intramedullary nailing for tibial fracture were assessed, 599 were eligible and 501 provided informed consent and were enrolled. Interventions Patients were allocated centrally to self administer daily LIPUS (n=250) or use a sham device (n=251) until their tibial fracture showed radiographic healing or until one year after intramedullary fixation. Main outcome measures Primary registry specified outcome was time to radiographic healing within one year of fixation; secondary outcome was rate of non-union. Additional protocol specified outcomes included short form-36 (SF-36) physical component summary (PCS) scores, return to work, return to household activities, return to ≥80% of function before injury, return to leisure activities, time to full weight bearing, scores on the health utilities index (mark 3), and adverse events related to the device. Results SF-36 PCS data were acquired from 481/501 (96%) patients, for whom

  15. Comparison of low-intensity pulsed ultrasound and pulsed electromagnetic field treatments on OPG and RANKL expression in human osteoblast-like cells.

    PubMed

    Borsje, Manon A; Ren, Yijin; de Haan-Visser, H Willy; Kuijer, Roel

    2010-05-01

    To compare two clinically applied treatments to stimulate bone healing-low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF)-for their effects on RANKL and OPG expression in osteoblast-like cells in vitro. LIPUS or PEMF was applied to Saos-2 cells for 10 minutes or 3 hours. RANKL and OPG expressions were analyzed at 0, 4, 8, or 12 hours after treatment with real-time PCR. Secreted protein levels in culture supernatant were analyzed at the same posttreatment time points using specific ELISA assays. Neither LIPUS nor PEMF had an effect on RANKL protein expression. OPG protein was significantly increased by LIPUS after 0 and 4 hours (brief short-term effect) and was increased almost 2.5-fold by PEMF after 8 hours. The mRNA levels of OPG and RANKL were hardly affected by LIPUS treatment at any time point. PEMF induced a fivefold increase in RANKL mRNA expression at t = 0. A brief PEMF treatment of 10 minutes resulted in downregulation of RANKL expression after 0 and 4 hours and upregulation at 12 hours. OPG mRNA was downregulated after 8 hours. The effects of LIPUS or PEMF expression on OPG and RANKL are limited. From our experiments, it seems that LIPUS treatment resulted in a quick protein response, while the response of cells to PEMF (3 hours) was delayed. The increase in OPG protein at 8 hours post PEMF treatment is indicative of reduction of osteolysis.

  16. Influence of low-intensity pulsed ultrasound on osteogenic tissue regeneration in a periodontal injury model: X-ray image alterations assessed by micro-computed tomography.

    PubMed

    Wang, Yunji; Chai, Zhaowu; Zhang, Yuanyuan; Deng, Feng; Wang, Zhibiao; Song, Jinlin

    2014-08-01

    This study was conducted to evaluate, with micro-computed tomography, the influence of low-intensity pulsed ultrasound on wound-healing in periodontal tissues. Periodontal disease with Class II furcation involvement was surgically produced at the bilateral mandibular premolars in 8 adult male beagle dogs. Twenty-four teeth were randomly assigned among 4 groups (G): G1, periodontal flap surgery; G2, periodontal flap surgery+low-intensity pulsed ultrasound (LIPUS); G3, guided tissue regeneration (GTR) surgery; G4, GTR surgery plus LIPUS. The affected area in the experimental group was exposed to LIPUS. At 6 and 8weeks, the X-ray images of regenerated teeth were referred to micro-CT scanning for 3-D measurement. Bone volume (BV), bone surface (BS), and number of trabeculae (Tb) in G2 and G4 were higher than in G1 and G3 (p<0.05). BV, BS, and Tb.N of the GTR+LIPUS group were higher than in the GTR group. BV, BS, and Tb.N of the LIPUS group were higher than in the periodontal flap surgery group. LIPUS irradiation increased the number, volume, and area of new alveolar bone trabeculae. LIPUS has the potential to promote the repair of periodontal tissue, and may work effectively if combined with GTR. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Low-intensity pulsed ultrasound induces apoptosis in osteoclasts: Fish scales are a suitable model for the analysis of bone metabolism by ultrasound.

    PubMed

    Suzuki, Nobuo; Hanmoto, Taizo; Yano, Sachiko; Furusawa, Yukihiro; Ikegame, Mika; Tabuchi, Yoshiaki; Kondo, Takashi; Kitamura, Kei-ichiro; Endo, Masato; Yamamoto, Toshio; Sekiguchi, Toshio; Urata, Makoto; Mikuni-Takagaki, Yuko; Hattori, Atsuhiko

    2016-05-01

    Using fish scales in which osteoclasts and osteoblasts coexist on the calcified bone matrix, we examined the effects of low-intensity pulsed ultrasound (LIPUS) on both osteoclasts and osteoblasts. At 3h of incubation after LIPUS treatment, osteoclastic markers such as tartrate-resistant acid phosphatase (TRAP) and cathepsin K mRNA expressions decreased significantly while mRNA expressions of osteoblastic markers, osteocalcin, distal-less homeobox 5, runt-related transcription factor 2a, and runt-related transcription factor 2b, increased significantly. At 6 and 18h of incubation, however, both osteoclastic and osteoblastic marker mRNA expression did not change at least present conditions. Using GeneChip analysis of zebrafish scales treated with LIPUS, we found that cell death-related genes were upregulated with LIPUS treatment. Real-time PCR analysis indicated that the expression of apoptosis-related genes also increased significantly. To confirm the involvement of apoptosis in osteoclasts with LIPUS, osteoclasts were induced by autotransplanting scales in goldfish. Thereafter, the DNA fragmentation associated with apoptosis was detected in osteoclasts using the TUNEL (TdT-mediated dUTP nick end labeling) method. The multi-nuclei of TRAP-stained osteoclasts in the scales were labeled with TUNEL. TUNEL staining showed that the number of apoptotic osteoclasts in goldfish scales was significantly elevated by treatment with LIPUS at 3h of incubation. Thus, we are the first to demonstrate that LIPUS directly functions to osteoclasts and to conclude that LIPUS directly causes apoptosis in osteoclasts shortly after exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Enhancement of Cell Ingrowth, Proliferation, and Early Differentiation in a Three-Dimensional Silicon Carbide Scaffold Using Low-Intensity Pulsed Ultrasound

    PubMed Central

    Lin, Liangjun

    2015-01-01

    Concerns over the use of autografts or allografts have necessitated the development of biomaterials for bone regeneration. Various studies have been performed to optimize the cultivation of osteogenic cells using osteoconductive porous scaffolds. The aim of this study was to evaluate the osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a silicon carbide (SiC) porous ceramic scaffold promoted with low-intensity pulsed ultrasound. MC3T3-E1 mouse preosteoblasts were seeded onto scaffolds and cultured for 4 and 7 days with daily of 20-min ultrasound treatment. The cells were evaluated for cell attachment, morphology, viability, ingrowth depth, volumetric proliferation, and early differentiation. After 4 and 7 days of culture and ultrasound exposure, the cell density was higher in the ultrasound-treated group compared with the sham-treated group on SiC scaffolds. The cell ingrowth depths inside the SiC scaffolds were 149.2±27.3 μm at 1 day, 310.1±12.6 μm for the ultrasound-treated group and 248.0±19.7 μm for the sham control at 4 days, and 359.6±18.5 μm for the ultrasound-treated group and 280.0±17.7 μm for the sham control at 7 days. They were significantly increased, that is, 25% (p=0.0029) and 28% (p=0.0008) increase, respectively, with ultrasound radiation force as compared with those in sham control at 4 and 7 days postseeding. The dsDNA contents were 583.5±19.1 ng/scaffold at 1 day, 2749.9±99.9 ng/scaffold for the ultrasound-treated group and 2514.9±114.7 ng/scaffold for the sham control at 4 days, and 3582.3±325.3 ng/scaffold for the ultrasound-treated group and 2825.7±134.3 ng/scaffold for the sham control at 7 days. There was a significant difference in the dsDNA content between the ultrasound- and sham-treated groups at 4 and 7 days. The ultrasound-treated group with the SiC construct showed a 9% (p=0.00029) and 27% (p=0.00017) increase in the average dsDNA content at 4 and 7 days over

  19. Enhancement of cell ingrowth, proliferation, and early differentiation in a three-dimensional silicon carbide scaffold using low-intensity pulsed ultrasound.

    PubMed

    Wu, Lin; Lin, Liangjun; Qin, Yi-Xian

    2015-01-01

    Concerns over the use of autografts or allografts have necessitated the development of biomaterials for bone regeneration. Various studies have been performed to optimize the cultivation of osteogenic cells using osteoconductive porous scaffolds. The aim of this study was to evaluate the osteogenic efficiency of bone cell ingrowth, proliferation, and early differentiation in a silicon carbide (SiC) porous ceramic scaffold promoted with low-intensity pulsed ultrasound. MC3T3-E1 mouse preosteoblasts were seeded onto scaffolds and cultured for 4 and 7 days with daily of 20-min ultrasound treatment. The cells were evaluated for cell attachment, morphology, viability, ingrowth depth, volumetric proliferation, and early differentiation. After 4 and 7 days of culture and ultrasound exposure, the cell density was higher in the ultrasound-treated group compared with the sham-treated group on SiC scaffolds. The cell ingrowth depths inside the SiC scaffolds were 149.2±27.3 μm at 1 day, 310.1±12.6 μm for the ultrasound-treated group and 248.0±19.7 μm for the sham control at 4 days, and 359.6±18.5 μm for the ultrasound-treated group and 280.0±17.7 μm for the sham control at 7 days. They were significantly increased, that is, 25% (p=0.0029) and 28% (p=0.0008) increase, respectively, with ultrasound radiation force as compared with those in sham control at 4 and 7 days postseeding. The dsDNA contents were 583.5±19.1 ng/scaffold at 1 day, 2749.9±99.9 ng/scaffold for the ultrasound-treated group and 2514.9±114.7 ng/scaffold for the sham control at 4 days, and 3582.3±325.3 ng/scaffold for the ultrasound-treated group and 2825.7±134.3 ng/scaffold for the sham control at 7 days. There was a significant difference in the dsDNA content between the ultrasound- and sham-treated groups at 4 and 7 days. The ultrasound-treated group with the SiC construct showed a 9% (p=0.00029) and 27% (p=0.00017) increase in the average dsDNA content at 4 and 7 days over

  20. Comparative study of the effects of low-intensity pulsed ultrasound and low-level laser therapy on injured muscle repair

    NASA Astrophysics Data System (ADS)

    Renno, Ana Claudia Muniz; Toma, Renata Luri; Feitosa, Suellen Maurin; Fernandes, Kelly; de Oliveira, Poliani; Parizotto, N.; Ribeiro, Daniel Araki

    2011-03-01

    Muscle tissue is one of the most frequently affected by injury, whether during sports activities, or work activities. In this context, biochemical and biophysical resources have been studied to minimize the time of muscle regeneration. Among these, low intensity pulsed ultrasound (US) and low level laser therapy (LLLT) may be highlighted. Despite a series of evidences about the positive effects of these resources in the process of tissue regeneration, the cellular and morphological changes triggered by LLLT and U.S. are still largely unknown. Thus, the aim of this study was to investigate the effects of US and LLLT on muscle repair after cryolesion by means of histopathological analysis and immunohistochemistry for COX-2. A total of thirty five male Wistar rats were randomly distributed into 4 groups: intact control group; injured control group: muscle injured animals without any treatment; laser treated group: muscle injured animals treated with 830 nm laser and ultra-sound treated group: muscle injured animals treated with US. The treatments started 24 hours post-surgery and were performed during 6 sessions. The animals exposed to lasertherapy pointed out minor degenerative changes of muscle tissue. In the same way, exposure to ultrasound was able to reduce tissue injuries induced by cryolesion, but less intense than laser therapy. Strong COX-2 positive cells were found in rats submitted to cryolesion only, whereas COX-2 immunoexpression was lower in laser treated or ultrasound treated groups. In summary, this study reveals that both lasertherapy and ultrasound have positive effects on muscle repair in rats.

  1. A preliminary study of the effect of low intensity pulsed ultrasound on new bone formation during mandibular distraction osteogenesis in rabbits.

    PubMed

    Xie, L K; Wangrangsimakul, K; Suttapreyasri, S; Cheung, L K; Nuntanaranont, T

    2011-07-01

    This study assesses the effect of low intensity pulsed ultrasound (LIPUS) on new bone formation during mandibular distraction osteogenesis (DO) in rabbits. 24 rabbits underwent DO on the right side of the mandible. 12 rabbits received a daily 20-min LIPUS (1.5 MHz, 30 mW/cm2) treatment on the first day of the distraction until they were killed at week 0 (immediately after the distraction), week 2 and week 4 after the distraction. Four rabbits were killed at each time point. The other 12 rabbits followed the same protocol without the ultrasound treatment. A plain radiography, a micro-CT scan, a microhardness test and a histological examination were used to evaluate new bone formation in the distraction gap. At week 0 and week 2 after the distraction, the treatment groups showed higher radiopacity and microhardness (p<0.05), and more bone formation was detected by the histological examination. At week 4 after the distraction, there was no statistical difference between the two groups. In this study, LIPUS accelerated new bone formation during the distraction period and 2 weeks after the distraction, which implies that the effective time for using LIPUS is in the early stage of DO. Copyright © 2011 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  2. Treatment of chronic (>1 year) fracture nonunion: heal rate in a cohort of 767 patients treated with low-intensity pulsed ultrasound (LIPUS).

    PubMed

    Zura, Robert; Della Rocca, Gregory J; Mehta, Samir; Harrison, Andrew; Brodie, Chris; Jones, John; Steen, R Grant

    2015-10-01

    Established fracture nonunions rarely heal without secondary intervention. Revision surgery is the most common intervention, though non-surgical options for nonunion would be useful if they could overcome nonunion risk factors. Our hypothesis is that low-intensity pulsed ultrasound (LIPUS) can enhance heal rate (HR) in fractures that remain nonunion after one year, relative to the expected HR in the absence of treatment, which is expected to be negligible. We collated outcomes from a prospective patient registry required by the U.S. Food & Drug Administration. Patient data were collected over a 4-year period beginning in 1994 and were individually reviewed and validated by a registered nurse. Patients were only included if they had four data points available: date when fracture occurred; date when LIPUS treatment began; date when LIPUS treatment ended; and a dichotomous outcome of healed vs. failed, assessed by clinical and radiological criteria. Data were used to calculate two derived variables: days to treatment (DTT) with LIPUS, and days on treatment (DOT) with LIPUS. Every validated chronic nonunion patient (DTT>365 days) with complete data is reported. Heal rate for chronic nonunion patients (N=767) treated with LIPUS was 86.2%. Heal rate was 82.7% among 98 patients with chronic nonunion ≥5 years duration, and 12 patients healed after chronic nonunion >10 years (HR=63.2%). There was more patient loss to follow-up, non-compliance, and withdrawal, comparing chronic nonunion patients to all other patients (p<0.0001). Patient age was the only factor associated with failure to heal among chronic nonunions (p<0.004). Chronic nonunion patients averaged 3.1 surgical procedures prior to LIPUS, but some LIPUS-treated patients were able to heal without revision surgery. Among 91 patients who received LIPUS ≥90 days after their last surgery, HR averaged 85.7%, and the time from last surgery to index use of LIPUS averaged 449.6 days. Low-intensity pulsed ultrasound

  3. Efficacy of focused low-intensity pulsed ultrasound therapy for the management of knee osteoarthritis: a randomized, double blind, placebo-controlled trial

    PubMed Central

    Jia, Lang; Wang, Yan; Chen, Jinyun; Chen, Wenzhi

    2016-01-01

    The aim of this study was to investigate the effects of focused low-intensity pulsed ultrasound (FLIPUS) therapy on the functional and health status of patients with knee osteoarthritis (KOA). A total of 106 subjects with bilateral KOA were randomized sequentially into two groups. Group I received FLIPUS + diclofenac sodium, and group II received sham FLIPUS + diclofenac sodium. The therapeutic effects of the interventions were evaluated by measuring changes in VAS pain, the WOMAC scores, and the LI scores after 10 days of treatment as well as changes in LI and VAS at follow-up, 4 and 12 weeks later. In addition, changes in the range of motion, ambulation speed, and the SF-36 in each group were recorded after 10 days of treatment. Compared with those in group II, patients in group Ishowed significant improvements in VAS, WOMAC, LI, ambulation speed, and most items in the SF-36 after 10 days of treatment. In addition, patients in group I showed significant improvements in LI and VAS at follow-up. There were no FLIPUS-related adverse events during and after the interventions. In conclusion, FLIPUS is a safe and effective treatment modality for relieving pain and improving the functions and quality of life of patients with KOA. PMID:27748432

  4. Low-intensity pulsed ultrasound (LIPUS) inhibits LPS-induced inflammatory responses of osteoblasts through TLR4-MyD88 dissociation.

    PubMed

    Nakao, Juna; Fujii, Yasuyuki; Kusuyama, Joji; Bandow, Kenjiro; Kakimoto, Kyoko; Ohnishi, Tomokazu; Matsuguchi, Tetsuya

    2014-01-01

    Previous reports have shown that osteoblasts are mechano-sensitive. Low-intensity pulsed ultrasound (LIPUS) induces osteoblast differentiation and is an established therapy for bone fracture. Here we have examined how LIPUS affects inflammatory responses of osteoblasts to LPS. LPS rapidly induced mRNA expression of several chemokines including CCL2, CXCL1, and CXCL10 in both mouse osteoblast cell line and calvaria-derived osteoblasts. Simultaneous treatment by LIPUS significantly inhibited mRNA induction of CXCL1 and CXCL10 by LPS. LPS-induced phosphorylation of ERKs, p38 kinases, MEK1/2, MKK3/6, IKKs, TBK1, and Akt was decreased in LIPUS-treated osteoblasts. Furthermore, LIPUS inhibited the transcriptional activation of NF-κB responsive element and Interferon-sensitive response element (ISRE) by LPS. In a transient transfection experiment, LIPUS significantly inhibited TLR4-MyD88 complex formation. Thus LIPUS exerts anti-inflammatory effects on LPS-stimulated osteoblasts by inhibiting TLR4 signal transduction.

  5. The osteogenic activity of human mandibular fracture haematoma-derived cells is stimulated by low-intensity pulsed ultrasound in vitro.

    PubMed

    Imai, Y; Hasegawa, T; Takeda, D; Akashi, M; Lee, S Y; Niikura, T; Shibuya, Y; Kurosaka, M; Komori, T

    2014-03-01

    Low intensity pulsed ultrasound (LIPUS) stimulation is a clinically established treatment method used to accelerate long bone fracture healing; however, this method is currently not applied to mandibular fractures. In this study, we investigated the effects of LIPUS on human mandibular fracture haematoma-derived cells (MHCs) in order to explore the possibility of applying LIPUS treatment to mandibular fractures. MHCs were isolated from five patients. The cells were divided into two groups: (1) LIPUS (+) group: MHCs cultured in osteogenic medium with LIPUS treatment; and (2) LIPUS (-) group: MHCs cultured in osteogenic medium without LIPUS treatment. The osteogenic differentiation potential and proliferation of the MHCs were compared between the two groups. The waveform used was equal to the wave conditions of a clinical fracture healing system. The gene expression levels of ALP, OC, Runx2, OSX, OPN, and PTH-R1 and mineralization were increased in the LIPUS (+) group compared to the LIPUS (-) group. There were no significant differences in cell proliferation between the two groups. These findings demonstrate the significant effects of LIPUS on the osteogenic differentiation of MHCs. This study provides significant evidence for the potential usefulness of the clinical application of LIPUS to accelerate mandibular fracture healing.

  6. Osteogenic effects of low-intensity pulsed ultrasound, extracorporeal shockwaves and their combination - an in vitro comparative study on human periosteal cells.

    PubMed

    Tam, Kam-Fai; Cheung, Wing-Hoi; Lee, Kwong-Man; Qin, Ling; Leung, Kwok-Sui

    2008-12-01

    Our previous studies have shown that on human periosteal cells, low-intensity pulsed ultrasound (LIPUS) has an immediate stimulatory effect whereas extracorporeal shockwaves (ESW) have an delayed stimulatory effect. Therefore, we hypothesized that a combined ESW and LIPUS treatment might provide additive or synergistic effects on periosteal cells, by using ESW to trigger a biological activity while using LIPUS to maintain the stimulated activity. Human periosteal cells were subjected to a single session of ESW treatment on day 0 and/or daily LIPUS treatments or no treatment (control). The cell viability, proliferation, and alkaline phosphatase activity on day 6 and day 18 as well as matrix mineralization on day 35 were measured. Results revealed that LIPUS alone had early positive effects on the activities on day 6 only. In contrast, ESW alone had an early destructive effect but exerted delayed stimulatory effects on the cellular activities on day 18. The combined treatment of ESW plus LIPUS produced effects that were comparable to the ESW treatment alone. Although these findings suggest that ESW and LIPUS stimulate the periosteal cells in two different ways and at different times, their additive or synergistic effects could not be proven.

  7. Different performances of CXCR4, integrin-1β and CCR-2 in bone marrow stromal cells (BMSCs) migration by low-intensity pulsed ultrasound stimulation.

    PubMed

    Xiao, Weixiong; Xu, Qian; Zhu, Zhimin; Li, Lei; Chen, Wenchuan

    2017-02-01

    Low-intensity pulsed ultrasound (LIPUS) is an established therapy for fracture healing where bone marrow stromal cells (BMSCs) migration is crucial to bone regeneration. This work focused on different performances of C-X-C-receptor 4 (CXCR4), integrin-1β and chemokine-chemokine receptor2 (CCR-2) in BMSCs migration by LIPUS stimulation. Single 20-min LIPUS treatment was applied to BMSCs during wound healing assay with or without the inhibitor AMD3100. The migration rate of BMSCs with LIPUS stimulation exhibited a higher closure rate than that of BMSCs without LIPUS stimulation, which was 1.89 μm/h and 1.38 μm/h, respectively. After LIPUS stimulation, significant elevation of the expression of CXCR4, integrin-1β and CCR-2 was observed. When AMD3100 was added, the migration rate of the BMSCs was obviously declined with or without LIPUS treatment. Furthermore, the expression of CXCR4 was significantly down-regulated by AMD3100, while integrin-1β and CCR-2 were less affected. It suggested that the enhancement of the migration of the BMSCs by LIPUS was inhibited by AMD3100. The results confirmed that LIPUS stimulation was able to activate and improve migration of BMSCs. Nevertheless, CXCR4 and both integrin-1β and CCR-2 had different roles in BMSCs migration after LIPUS treatment.

  8. Effects of Low-Intensity Pulsed Ultrasound on Orthodontic Tooth Movement and Orthodontically Induced Inflammatory Root Resorption in Ovariectomized Osteoporotic Rats.

    PubMed

    Dahhas, Feras Y; El-Bialy, Tarek; Afify, Ahmed R; Hassan, Ali H

    2016-03-01

    This study investigated the effects of low-intensity pulsed ultrasound (LIPUS) on orthodontic tooth movement (OTM) and orthodontically induced inflammatory root resorption (OIRR) in ovariectomized osteoporotic rats. Forty-eight 28-d-old female Wistar rats were divided into ovariectomized and intact groups. In both groups, animals were left untreated; treated with 50 g mesially directed orthodontic force on the maxillary first molars using nickel-titanium closed-coil springs for 28 d; or treated with the same orthodontic protocol along with a 20-min LIPUS application on alternate days for 28 d. Extent of OTM and amount of OIRR of mesial roots were measured on three-dimensionally reconstructed micro-computed tomography images. Ovariectomy increased OIRR (p < 0.05). LIPUS reduced root volumetric loss regardless of ovariectomy status (p < 0.05); only ovariectomized animals had decreased OTM (p < 0.05). LIPUS normalizes OTM and attenuates OIRR in ovariectomized osteoporotic rats. It may therefore be beneficial in women with postmenopausal osteoporosis.

  9. Activation of Mechanosensitive Transcription Factors in Murine C2C12 Mesenchymal Precursors by Focused Low-Intensity Pulsed Ultrasound (FLIPUS).

    PubMed

    Puts, Regina; Rikeit, Paul; Ruschke, Karen; Kadow-Romacker, Anke; Hwang, Soyoung; Jenderka, Klaus-Vitold; Knaus, Petra; Raum, Kay

    2016-10-01

    In this paper, we investigated the mechanoresponse of C2C12 mesenchymal precursor cells to focused low-intensity pulsed ultrasound (FLIPUS). The setup has been developed for in vitro stimulation of adherent cells in the defocused far field of the ultrasound propagating through the bottom of the well plate. Twenty-four-well tissue culture plates, carrying the cell monolayers, were incubated in a temperature-controlled water tank. The ultrasound was applied at 3.6-MHz frequency, pulsed at 100-Hz repetition frequency with a 27.8% duty cycle, and calibrated at an output intensity of ISATA = 44.5 ±7.1 mW/cm(2). Numerical sound propagation simulations showed no generation of standing waves in the well plate. The response of murine C2C12 cells to FLIPUS was evaluated by measuring activation of mechanosensitive transcription factors, i.e., activator protein-1 (AP-1), specificity protein 1 (Sp1), and transcriptional enhancer factor (TEAD), and expression of mechanosensitive genes, i.e., c-fos, c-jun, heparin binding growth associated molecule (HB-GAM), and Cyr-61. FLIPUS induced 50% ( p ≤ 0.05 ) and 70% ( p ≤ 0.05 ) increases in AP-1 and TEAD promoter activities, respectively, when stimulated for 5 min. The Sp1 activity was enhanced by about 20% ( p ≤ 0.05 ) after 5-min FLIPUS exposure and the trend persisted for 30-min ( p ≤ 0.05 ) and 1-h ( p ≤ 0.05 ) stimulation times. Expressions of mechanosensitive genes c-fos ( p ≤ 0.05 ), c-jun ( p ≤ 0.05 ), HB-GAM ( p ≤ 0.05 ), and cystein-rich protein 61 ( p ≤ 0.05 ) were enhanced in response to 5-min FLIPUS stimulation. The increase in proliferation of C2C12s occurred after the FLIPUS stimulation ( p ≤ 0.05 ), with AP-1, Sp1, and TEAD possibly regulating the observed cellular activities.

  10. Pathological fracture of the femur in Alagille syndrome that was treated with low-intensity pulsed ultrasound stimulation and an Ilizarov ring fixator: a case report

    PubMed Central

    2014-01-01

    Background Alagille syndrome is a multisystem disorder, which is characterized by hypoplasia of the intrahepatic bile ducts, malformations of the cardiovascular system, eyes, and vertebral column, and abnormal facies. Several of the characteristics of Alagille syndrome may result in an especially high risk of fracture. The majority of patients suffer from chronic cholestasis, which can have a variety of adverse effects on bone metabolism. In Alagille syndrome, fractures primarily occur in the lower limb long bones in the absence of significant trauma. Case presentation A 9-year-old Japanese girl with Alagille syndrome was admitted to our institution with marked hyperbilirubinemia and a pathological fracture of the femur. She had been diagnosed with biliary atresia at the age of 1 month and treated with surgical bile duct reconstruction, vitamins D and K, and ursodeoxycholic acid. However, her liver dysfunction and hyperbilirubinemia worsened. The pathological fracture of the femur was treated with low-intensity pulsed ultrasound stimulation (LIPUS) and an Ilizarov ring fixator. Seventy-four days after surgery, the patient had anatomically and functionally recovered. There was no leg-length discrepancy and no angular malalignment of the lower extremities as measured clinically and radiographically. The range of motion of the hip, knee, and ankle of the patient’s operative leg matched the range of motion in the nonoperative leg. Conclusion To the best of our knowledge, there are no reports on use of the Ilizarov frame and LIPUS in diaphyseal femoral fractures in Alagille syndrome. This case report provides evidence that this procedure is successful for managing such diaphyseal fractures in Alagille syndrome. PMID:25004954

  11. All-in-one low-intensity pulsed ultrasound stimulation system using piezoelectric micromachined ultrasonic transducer (pMUT) arrays for targeted cell stimulation.

    PubMed

    Lee, Wonjun; Yoo, Seungjun; Jung, Joontaek; Kang, Woojin; Wang, Wei; Moon, Cheil; Choi, Hongsoo

    2017-09-19

    A novel cell-stimulation system was fabricated using 10 × 29 piezoelectric micromachined ultrasonic transducer (pMUT) arrays for targeted ultrasonic cell stimulation. Both the diameter of a single pMUT element and the edge-to-edge gap were 120 μm, and the size of a pMUT array was 2.27 × 6.84 mm, to be placed at the bottom of a Transwell. The measured resonance frequency of a single pMUT element was 1.48 ± 0.13 MHz and the measured acoustic intensity of the pMUT array was 0.15 ± 0.03 MPa at 1 mm away from the transducer. A pMUT array was mounted on a print circuit board (PCB), which was designed in accordance with the size of a 12-well Transwell. The Transwell was placed on the PCB and wire bonding was performed to electrically connect the PCB and pMUT arrays. After wiring, the PCB and pMUT arrays were coated with 2.6-μm thick parylene-C to ensure biocompatibility and waterproofing. PC12 cells were used for ultrasonic cell stimulation tests to examine the proposed all-in-one low-intensity pulsed ultrasound stimulation system. Various stimulation times and duty cycles were used simultaneously for cell proliferation in a confined cell culture environment. All stimulation groups showed increased cell proliferation rates, in the range 138-166%, versus the proliferation rate of the control group.

  12. Low-Intensity Pulsed Ultrasound Stimulation Enhances Heat-Shock Protein 90 and Mineralized Nodule Formation in Mouse Calvaria-Derived Osteoblasts

    PubMed Central

    Miyasaka, Munemitsu; Nakata, Hidemi; Hao, Jia; Kim, You-Kyoung; Kasugai, Shohei

    2015-01-01

    Low-intensity pulsed ultrasound (LIPUS) has demonstrated its positive effects on osteogenic differentiation of mesenchymal stem cells and the proliferation and differentiation of osteoblasts, negative effects on osteoclast growth, and promotion of angiogenesis, leading to improvement of the tissue perfusion. Heat-shock proteins (HSPs) are initially identified as molecules encouraged and expressed by heat stress or chemical stress to cells and involved in the balance between differentiation and apoptosis of osteoblasts. However, it remains unclear if the effect of LIPUS on osteoblast differentiation could involve HSP expression and contribution. In this study, mouse calvarial osteoblasts were exposed to LIPUS at a frequency of 3.0 MHz by 30 mW/cm2 for 15 min or to 42°C heat shock for 20 min at day 3 of cell culture and examined for osteogenesis with pursuing induction of HSP27, HSP70, and HSP90. LIPUS as well as heat shock initially upregulated HSP90 and phosphorylation of Smad1 and Smad5, encouraging cell viability and proliferation at 24 h, enhancing mineralized nodule formation stronger by LIPUS after 10 days. However, HSP27, associated with BMP2-stimulated p38 mitogen-activated protein kinase during osteoblast differentiation, was downregulated by both stimulations at this early time point. Notably, these two stimuli maintained Smad1 phosphorylation with mineralized nodule formation even under BMP2 signal blockage. Therefore, LIPUS might be a novel inducer of osteoblastic differentiation through a noncanonical signal pathway. In conclusion, LIPUS stimulation enhanced cell viability and proliferation as early as 24 h after treatment, and HSP90 was upregulated, leading to dense mineralization in the osteoblast cell culture after 10 days. PMID:26421522

  13. Low-intensity pulsed ultrasound enhances posterior spinal fusion implanted with mesenchymal stem cells-calcium phosphate composite without bone grafting.

    PubMed

    Hui, Celine Fan Fong; Chan, Chun Wai; Yeung, Hiu Yan; Lee, Kwong Man; Qin, Ling; Li, Gang; Leung, Kwok Sui; Hu, Yun Yu; Cheng, Jack Chun Yiu

    2011-06-01

    Experimental study on the effect of low-intensity pulsed ultrasound (LIPUS) on rabbit spinal fusion with mesenchymal stem cell (MSC)-derived osteogenic cells and bioceramic composite. To investigate the efficacy of LIPUS in enhancing fusion rate and bone formation with porous tricalcium phosphate (TCP) bioceramic scaffold impregnated with MSCs without any bone grafts. The goal of spinal fusion in the corrective spinal surgery for spinal deformities is to achieve solid bony fusion between selected vertebral segments. Previous studies with bone morphogenetic proteins and genetically manipulated materials revealed significant difficulties in actual clinical application. Alternative such as LIPUS has been shown to be effective in enhancing healing of fracture and nonunion clinically. Its potential for enhancing spinal fusion warrants further in-depth study. Posterolateral intertransverse processes spinal fusion at the L5 and L6 levels were evaluated in New Zealand white rabbit model. The animals were divided into three groups with (A) TCP alone, (B) TCP with differentiated MSCs, and (C) TCP with differentiated MSCs and LIPUS treatment. At week 7 postoperation, manual palpation, peripheral quantitative computed tomography, and histomorphometric assessments were performed. At week 7 postoperation, a statistically significant increase in clinical fusion by manual palpation was observed in group C animals treated with LIPUS (86%) in comparing with groups A (0%) and B (14%) without LIPUS. With peripheral quantitative computed tomographic analysis, the bone volume of group C fusion mass was significantly larger than the other two groups. Group C fusion also had better osteointegration length between host bone and implanted composite and more new bone formed in the TCP implants. Importantly, all the group C animals had osteochondral bridging--early stage of bony fusion histologically. Endochondral ossification was observed at the junction between the cartilaginous and osseous

  14. Relation of low-intensity pulsed ultrasound to the cell density of scaffold-free cartilage in a high-density static semi-open culture system.

    PubMed

    Uenaka, Kazuhiro; Imai, Shinji; Ando, Kosei; Matsusue, Yoshitaka

    2010-11-01

    A scaffold-free cartilage construct, analogous to those found during embryonic precartilage condensation, has received much attention as a novel modality for tissue-engineered cartilage. In the present study, we developed an uncomplicated culture system by which scaffold-free cartilage-like tissues are produced using cell-cell interactions. With this system, we attempted to prevent dedifferentiation and reverse the phenotypic modulations by adjusting the cell density. We investigated whether low-intensity pulsed ultrasound (LIPUS) enhances matrix synthesis of the scaffold-free cartilage construct. Rat articular chondrocytes multiplied in monolayers were seeded onto the synthetic porous membrane at stepwise cell densities (i.e., 1.0, 2.0, and 4.0 × 10(7) cells/cm(2)) to allow formation of a scaffold-free cartilage construct via cell-cell interaction. The cartilage constructs were then stimulated by LIPUS for 20 min/day. To investigate the effect of LIPUS stimulation on matrix synthesis, expression of mRNA for cartilage matrix molecules was quantified by a real-time reverse transcription-polymerase chain reaction. Synthesis of type II collagen, type I collagen, and proteoglycan was also assessed histologically. Only the chondrocytes cultured at high cell densities in the 2.0 × 10(7)cells/cm(2) group became concentrated and formed a plate-like construct similar to native articular cartilage by macroscopic and histological assessments. Statistical analysis on the matrix gene expression demonstrated that the levels of type II collagen and aggrecan mRNA of the 2.0 × 10(7)cells/cm(2) group were significantly higher than with the other two cell-density groups. Interestingly, the LIPUS application led to a statistically significant enhancement of aggrecan gene expression only in the 2.0 × 10(7) cells/cm(2) group. The current study presents a semi-open static culture system that facilitates production of the scaffold-free constructs from monolayer-cultured chondrocytes

  15. Recombinant human parathyroid hormone (PTH 1-34) and low-intensity pulsed ultrasound have contrasting additive effects during fracture healing.

    PubMed

    Warden, Stuart J; Komatsu, David E; Rydberg, Johanna; Bond, Julie L; Hassett, Sean M

    2009-03-01

    Fracture healing is thought to be naturally optimized; however, recent evidence indicates that it may be manipulated to occur at a faster rate. This has implications for the duration of morbidity associated with bone injuries. Two interventions found to accelerate fracture healing processes are recombinant human parathyroid hormone [1-34] (PTH) and low-intensity pulsed ultrasound (LIPUS). This study aimed to investigate the individual and combined effects of PTH and LIPUS on fracture healing. Bilateral midshaft femur fractures were created in Sprague-Dawley rats, and the animals treated 7 days/week with PTH (10 microg/kg) or a vehicle solution. Each animal also had one fracture treated for 20 min/day with active-LIPUS (spatial-averaged, temporal-averaged intensity [I(SATA)]=100 mW/cm(2)) and the contralateral fracture treated with inactive-LIPUS (placebo). Femurs were harvested 35 days following injury to permit micro-computed tomography, mechanical property and histological assessments of the fracture calluses. There were no interactions between PTH and LIPUS indicating that their effects were additive rather than synergistic. These additive effects were contrasting with LIPUS primarily increasing total callus volume (TV) without influencing bone mineral content (BMC), and PTH having the opposite effect of increasing BMC without influencing TV. As a consequence of the effect of LIPUS on TV but not BMC, it decreased volumetric bone mineral density (vBMD) resulting in a less mature callus. The decreased maturity and persistence of cartilage at the fracture site when harvested offset any beneficial mechanical effects of the increased callus size with LIPUS. In contrast, the effect of PTH on callus BMC but not TV resulted in increased callus vBMD and a more mature callus. This resulted in PTH increasing fracture site mechanical strength and stiffness. These data suggest that PTH may have utility in the treatment of acute bone fractures, whereas LIPUS at an I(SATA) of

  16. Role of Reactive Oxygen Species during Low-Intensity Pulsed Ultrasound Application in MC-3 T3 E1 Pre-osteoblast Cell Culture.

    PubMed

    Kaur, Harmanpreet; Siraki, Arno G; Uludağ, Hasan; Dederich, Douglas N; Flood, Patrick; El-Bialy, Tarek

    2017-08-11

    We evaluated the activation of mitogen-activated protein kinase (MAPK) activation through reactive oxygen species (ROS) by application of low-intensity ultrasound (LIPUS) to MC-3 T3 E1 pre-osteoblasts. The cells were subjected to one LIPUS application for either 10 or 20 min, and the control group was exposed to a sham transducer. For ROS inhibition, 10 μM diphenylene iodonium (DPI) was added to the cells an hour before LIPUS application. Samples were collected 1, 3, 6, 12 and 24 h after LIPUS application, and cells were evaluated for ROS generation, cell viability, gene expression and MAPK activation by immunoblot analyses. LIPUS caused a significant increase in ROS and cell viability in the non-DPI-treated group. Expression of RUNX2, OCN and OPN mRNA was higher in the LIPUS-treated groups at 1 h in both the DPI-treated and non-DPI-treated groups; RUNX2 and OCN mRNA levels increased at 6 h. ERK1/2 activation was increased in the LIPUS-treated groups. These results indicate that LIPUS activates MAPK by ROS generation in MC-3 T3 E1 pre-osteoblasts. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  17. Low-intensity pulsed ultrasound activates ERK1/2 and PI3K-Akt signalling pathways and promotes the proliferation of human amnion-derived mesenchymal stem cells.

    PubMed

    Ling, Li; Wei, Tianqin; He, Lianli; Wang, Yaping; Wang, Yan; Feng, Xiushan; Zhang, Wenqian; Xiong, Zhengai

    2017-09-22

    This study was to investigate the effect and mechanism of low-intensity pulsed ultrasound (LIPUS) on the proliferation of human amnion-derived mesenchymal stem cells (hAD-MSCs). Human amnion-derived mesenchymal stem cells were isolated from the amnion of term placentas and identified by flow cytometry and differentiation culture. Proliferation of hAD-MSCs was investigated by Cell Counting Kit-8, cell cycle and EdU assays. Western blotting was used to determine the protein expression levels. Human amnion-derived mesenchymal stem cells were successfully isolated from the amnion and identified as multipotent mesenchymal stem cells. Low-intensity pulsed ultrasound promoted the proliferation of hAD-MSCs. Cell cycle analysis showed that LIPUS promoted cells to enter S and G2/M phases from G0/G1 phase. Western blot results showed that LIPUS promoted the phosphorylation and activation of ERK1/2 and Akt and significantly upregulated expression of cyclin D1, cyclin E1, cyclin A2 and cyclin B1. ERK1/2 inhibitor (U0126) and PI3K inhibitor (LY294002) significantly reduced LIPUS-induced phosphorylation of ERK1/2 and Akt, respectively, which in turn reduced the LIPUS-induced proliferation of hAD-MSCs. Low-intensity pulsed ultrasound can promote the proliferation of hAD-MSCs, and ERK1/2 and PI3K-Akt signalling pathways may play important roles in this process. © 2017 John Wiley & Sons Ltd.

  18. Low-intensity pulsed ultrasound treatment as an alternative to vascular bone graft surgery for a 5-year-long ulnar non-union in a patient with haemochromatosis.

    PubMed

    Povlsen, Sebastian Daniel; Povlsen, Bo

    2015-11-03

    We present the case of a 75-year-old woman with haemochromatosis who developed a 5-year-long right ulnar non-union after a shortening osteotomy to correct a malunited Colles' fracture. Standard surgical treatment for ulnar non-unions was attempted on 19 March 2008 and again on 20 April 2009, but the non-union persisted on 8 May 2012, as confirmed by CT scan. Vascular bone grafting and refixation was then considered, but the patient declined this extensive operation, instead choosing to try non-invasive low-intensity pulsed ultrasound treatment with an Exogen device. Just 4 months later, complete union as confirmed by CT scan was achieved. This is the first case demonstrating the efficacy of ultrasound treatment for long-standing non-unions resistant to surgery in patients with haemochromatosis, a disorder where iron deposition can provide suboptimal circumstances for bone healing. Our finding suggests that low-intensity pulsed ultrasound devices could be used as a first-line treatment for stable non-unions instead of revision surgery.

  19. Low-Intensity Pulsed Ultrasound Treatment at an Early Osteoarthritis Stage Protects Rabbit Cartilage From Damage via the Integrin/Focal Adhesion Kinase/Mitogen-Activated Protein Kinase Signaling Pathway.

    PubMed

    Xia, Peng; Shen, Shihao; Lin, Qiang; Cheng, Kai; Ren, Shasha; Gao, Mingxia; Li, Xueping

    2015-11-01

    To investigate whether low-intensity pulsed ultrasound (US) has different protective effects on early and late rabbit osteoarthritis cartilage via the integrin/focal adhesion kinase (FAK)/mitogen-activated protein kinase (MAPK) signaling pathway. Thirty-six New Zealand White rabbits were divided into early control, early osteoarthritis, early treatment, late control, late osteoarthritis, and late treatment groups. The early and late osteoarthritis and treatment groups underwent anterior cruciate ligament transection. The remaining groups underwent sham operations with knee joint exposure. The early and late treatment groups were exposed to low-intensity pulsed US 4 and 8 weeks after surgery. After 6 weeks of US exposure, pathologic changes on the articular surface of the femoral condyle were assessed by modified Mankin scores. Expression of type II collagen, matrix metalloproteinase, integrin β1, phosphorylated FAK, and MAPKs (including extracellular signal-regulated kinase 1/2, MAPK 38, and c-Jun N-terminal kinase) was assessed by Western blot analysis. Cartilage damage was less severe in the early treatment group than the early osteoarthritis group. The Mankin score was significantly lower in the early treatment group than the early osteoarthritis group (P < .05). There was no significant difference in cartilage damage or Mankin score between the late treatment and late osteoarthritis groups. There was a significant increase in type II collagen expression but a significant decrease in matrix metalloproteinase 13 expression in the early treatment group compared to the early osteoarthritis group, whereas no significant difference was found between the late treatment and late osteoarthritis groups. Integrin β1 and phosphorylated FAK expression was significantly higher, and phosphorylated extracellular signal-regulated kinase 1/2 and phosphorylated MAPK 38 expression was significantly lower in the early treatment group than the early osteoarthritis group. Our

  20. A REVIEW OF LOW-INTENSITY ULTRASOUND FOR CANCER THERAPY

    PubMed Central

    WOOD, ANDREW K. W.; SEHGAL, CHANDRA M.

    2015-01-01

    The literature describing the use of low-intensity ultrasound in four major areas of cancer therapy was reviewed - sonodynamic therapy, ultrasound mediated chemotherapy, ultrasound mediated gene delivery and antivascular ultrasound therapy. Each technique consistently resulted in the death of cancer cells and the bioeffects of ultrasound were primarily attributed to thermal actions and inertial cavitation. In each therapeutic modality, theranostic contrast agents composed of microbubbles played a role in both therapy and vascular imaging. The development of these agents is important as it establishes a therapeutic-diagnostic platform which can monitor the success of anti-cancer therapy. Little attention, however, has been given to either the direct assessment of the underlying mechanisms of the observed bioeffects or to the viability of these therapies in naturally occurring cancers in larger mammals; if such investigations provided encouraging data there could be a prompt application of a therapy technique in treating cancer patients. PMID:25728459

  1. The effects of low-intensity pulsed ultrasound and pulsed electromagnetic fields bone growth stimulation in acute fractures: a systematic review and meta-analysis of randomized controlled trials.

    PubMed

    Hannemann, P F W; Mommers, E H H; Schots, J P M; Brink, P R G; Poeze, M

    2014-08-01

    The aim of this systematic review and meta-analysis was to evaluate the best currently available evidence from randomized controlled trials comparing pulsed electromagnetic fields (PEMF) or low-intensity pulsed ultrasound (LIPUS) bone growth stimulation with placebo for acute fractures. We performed a systematic literature search of the medical literature from 1980 to 2013 for randomized clinical trials concerning acute fractures in adults treated with PEMF or LIPUS. Two reviewers independently determined the strength of the included studies by assessing the risk of bias according to the criteria in the Cochrane Handbook for Systematic Reviews of Interventions. Seven hundred and thirty-seven patients from 13 trials were included. Pooled results from 13 trials reporting proportion of nonunion showed no significant difference between PEMF or LIPUS and control. With regard to time to radiological union, we found heterogeneous results that significantly favoured PEMF or LIPUS bone growth stimulation only in non-operatively treated fractures or fractures of the upper limb. Furthermore, we found significant results that suggest that the use of PEMF or LIPUS in acute diaphyseal fractures may accelerate the time to clinical union. Current evidence from randomized trials is insufficient to conclude a benefit of PEMF or LIPUS bone growth stimulation in reducing the incidence of nonunions when used for treatment in acute fractures. However, our systematic review and meta-analysis suggest that PEMF or LIPUS can be beneficial in the treatment of acute fractures regarding time to radiological and clinical union. PEMF and LIPUS significantly shorten time to radiological union for acute fractures undergoing non-operative treatment and acute fractures of the upper limb. Furthermore, PEMF or LIPUS bone growth stimulation accelerates the time to clinical union for acute diaphyseal fractures.

  2. Applying low-intensity pulsed ultrasounds (LIPUS) to a zoledronate-associated atypical femoral shaft fracture without cessation of zoledronate therapy for 3 years follow up: a case report

    PubMed Central

    Arakawa, Shoutaro; Saito, Mitsuru; Kubota, Makoto; Suzuki, Hidehiko; Tsuchida, Shigeki; Hashimoto, Kurando; Marumo, Keishi

    2015-01-01

    Summary Reports are increasing regarding atypical femoral fractures (AFFs) caused by minor trauma in patients using bisphosphonates (BPs) for long periods. Patients with malignant skeletal metastases potentially are at greater risk for these AFFs, especially considering the high dose and the duration of treatment with BPs. We evaluated a case of atypical femoral shaft fracture treated with an intramedullary nail in a patient treated for five years with zoledronate who had breast cancer with metastases to bone. Although bone union was achieved without cessation of zoledronate therapy by applying low-intensity pulsed ultrasounds (LIPUS), the remodeling phase of the fracture healing process was delayed. For BPs-associated AFFs, LIPUS is an alternative to parathyroid hormone (PTH) analogs such as teriparatide that are contraindicated in patients with malignant skeletal metastases. LIPUS is an effective treatment for fracture healing and may avoid the necessity to discontinue BP therapy. PMID:26811711

  3. A Review on Brain Stimulation Using Low Intensity Focused Ultrasound

    PubMed Central

    Rezayat, Ehsan; Toostani, Iman Ghodrati

    2016-01-01

    Brain stimulation techniques are important in both basic and clinical studies. Majority of well-known brain stimulating techniques have low spatial resolution or entail invasive processes. Low intensity focused ultrasound (LIFU) seems to be a proper candidate for dealing with such deficiencies. This review recapitulates studies which explored the effects of LIFU on brain structures and its function, in both research and clinical areas. Although the mechanism of LIFU action is still unclear, its different effects from molecular level up to behavioral level can be explored in animal and human brain. It can also be coupled with brain imaging assessments in future research. PMID:27563411

  4. Improvement of activated sludge bacteria growth by low intensity ultrasound

    NASA Astrophysics Data System (ADS)

    Yan, Y. X.; Ding, J. Y.; Gao, J. L.

    2016-08-01

    Influence of low intensity ultrasound (US) on growth rate of bacteria separated from aerobic activated sludge was studied. In order to reveal the optimal ultrasonic conditions,specific oxygen uptake rate (SOUR) of activated sludge was first detected and results showed that the maximum SOUR was obtained (increased by 40%) at US intensity of 3 Wcm-2 and irradiation time of 10min. Under the optimal conditions, 2 species of bacteria isolated from activated sludge were sonicated and then cultivated for 36h, and increment of 6% and 10% of growth rate were detected for the 2 species of bacteria, respectively, indicating US irradiation of suitable parameters effectively improved activated sludge bacteria growth.

  5. Neuroprotective Effect of Low-Intensity Pulsed Ultrasound Against MPP(+)-Induced Neurotoxicity in PC12 Cells: Involvement of K2P Channels and Stretch-Activated Ion Channels.

    PubMed

    Zhao, Lu; Feng, Yi; Shi, Aiwei; Zhang, Lei; Guo, Shifang; Wan, Mingxi

    2017-09-01

    Parkinson's disease is the second most common neurodegenerative disease. It is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta. 1-Methyl-4-phenylpyridinium (MPP(+)) is a dopaminergic neuronal toxin that is widely used in constructing Parkinson's disease models in vitro. Low-intensity pulsed ultrasound (LIPUS) is a non-invasive therapeutic approach that has neuromodulation and neuroprotective effects in the central neural system; however, whether LIPUS can provide protection for dopaminergic neurons against MPP(+)-induced neurocytotoxicity remains unknown. In this study, we found that pre-treatment with LIPUS (1 MHz, 50 mW/cm(2), 20% duty cycle and 100-Hz pulse repetition frequency, 10 min) inhibited MPP(+)-induced neurotoxicity and mitochondrial dysfunction in PC12 cells. LIPUS decreased MPP(+)-induced oxidative stress by modulating antioxidant proteins, including thioredoxin-1 and heme oxygenase-1, and prevented neurocytotoxicity via the phosphoinositide 3-kinase (PI3K)-Akt and ERK1/2 pathways. Furthermore, these beneficial effects were attributed to the activation of K2P channels and stretch-activated ion channels by LIPUS. These data indicate that LIPUS protects neuronal cells from MPP(+)-induced cell death through the K2P channel- and stretch-activated ion channel-mediated downstream pathways. The data also suggest that LIPUS could be a promising therapeutic method in halting or retarding the degeneration of dopaminergic neurons in Parkinson's disease in a non-invasive manner. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  6. Prolonged stimulation with low-intensity ultrasound induces delayed increases in spontaneous hippocampal culture spiking activity.

    PubMed

    Kim, Hyun-Bum; Swanberg, Kelley M; Han, Hee-Sok; Kim, Jung-Chae; Kim, Jun-Woo; Lee, Sungon; Lee, C Justin; Maeng, Sungho; Kim, Tae-Seong; Park, Ji-Ho

    2017-03-01

    Ultrasound is a promising neural stimulation modality, but an incomplete understanding of its range and mechanism of effect limits its therapeutic application. We investigated the modulation of spontaneous hippocampal spike activity by ultrasound at a lower acoustic intensity and longer time scale than has been previously attempted, hypothesizing that spiking would change conditionally upon the availability of glutamate receptors. Using a 60-channel multielectrode array (MEA), we measured spontaneous spiking across organotypic rat hippocampal slice cultures (N = 28) for 3 min each before, during, and after stimulation with low-intensity unfocused pulsed or sham ultrasound (spatial-peak pulse average intensity 780 μW/cm(2) ) preperfused with artificial cerebrospinal fluid, 300 μM kynurenic acid (KA), or 0.5 μM tetrodotoxin (TTX) at 3 ml/min. Spike rates were normalized and compared across stimulation type and period, subregion, threshold level, and/or perfusion condition using repeated-measures ANOVA and generalized linear mixed models. Normalized 3-min spike counts for large but not midsized, small, or total spikes increased after but not during ultrasound relative to sham stimulation. This result was recapitulated in subregions CA1 and dentate gyrus and replicated in a separate experiment for all spike size groups in slices pretreated with aCSF but not KA or TTX. Increases in normalized 18-sec total, midsized, and large spike counts peaked predominantly 1.5 min following ultrasound stimulation. Our low-intensity ultrasound setup exerted delayed glutamate receptor-dependent, amplitude- and possibly region-specific influences on spontaneous spike rates across the hippocampus, expanding the range of known parameters at which ultrasound may be used for neural activity modulation. © 2016 Wiley Periodicals, Inc.

  7. Intramuscular Heating Characteristics of Multihour Low-Intensity Therapeutic Ultrasound

    PubMed Central

    Rigby, Justin H.; Taggart, Rebecca M.; Stratton, Kelly L.; Lewis, George K.; Draper, David O.

    2015-01-01

    Context The heating characteristics of a stationary device delivering sustained acoustic medicine with low-intensity therapeutic ultrasound (LITUS) are unknown. Objective To measure intramuscular (IM) heating produced by a LITUS device developed for long-duration treatment of musculoskeletal injuries. Design Controlled laboratory study. Setting University research laboratory. Patients or Other Participants A total of 26 healthy volunteers (16 men, 10 women; age = 23.0 ± 2.1 years, height = 1.74 ± 0.09 m, mass = 73.48 ± 14.65 kg). Intervention(s) Participants were assigned randomly to receive active (n = 20) or placebo (n = 6) LITUS at a frequency of 3 MHz and an energy intensity of 0.132 W/cm2 continuously for 3 hours with a single transducer or dual transducers on the triceps surae muscle. We measured IM temperature using thermocouples inserted at 1.5- and 3-cm depths into muscle. Temperatures were recorded throughout treatment and 30 minutes posttreatment. Main Outcome Measure(s) We used 2-sample t tests to determine the heating curve of the LITUS treatment and differences in final temperatures between depth and number of transducers. Results A mild IM temperature increase of 1°C was reached 10 ± 5 minutes into the treatment, and a more vigorous temperature increase of 4°C was reached 80 ± 10 minutes into the treatment. The maximal steady-state IM temperatures produced during the final 60 minutes of treatment at the 1.5-cm depth were 4.42°C ± 0.08°C and 3.92°C ± 0.06°C using 1 and 2 transducers, respectively. At the 3.0-cm depth, the maximal steady-state IM temperatures during the final 60 minutes of treatment were 3.05°C ± 0.09°C and 3.17°C ± 0.05°C using 1 and 2 transducers, respectively. We observed a difference between the temperatures measured at each depth (t78 = −2.45, P = .02), but the number of transducers used to generate heating was not different (t78 = 1.79, P = .08). Conclusions The LITUS device elicited tissue heating equivalent

  8. The effect of low-intensity therapeutic ultrasound in induced fracture of rat tibiae

    PubMed Central

    Fontes-Pereira, Aldo José; Teixeira, Renato da Costa; de Oliveira, Antônio Jorge Barbosa; Pontes, Roberto Waldesmand Farias; de Barros, Rui Sérgio Monteiro; Negrão, José Nazareno Cunha

    2013-01-01

    OBJECTIVE: To analyze the possible effects of low-intensity ultrasound on induced tibia fracture of rats in a dose commonly used in physical therapy treatments. METHODS: Twenty male Wistar rats were divided into two groups with 10 animals each. In the ultrasound group (USG), the animals were submitted to bone fracture and treatment with therapeutic ultrasound (TUS). Ultrasonic parameters are: frequency of 1.0 MHz, intensity of 0.2 W/cm2, pulsed mode at 20%, applied in stationary form during 10 minutes on the fracture region, for five weeks. The control group (CG) was submitted to bone fracture but not treated with ultrasound. RESULTS: The radiographies showed better consolidation in USG compared to CG. The statistical tests for alkaline phosphatase and serum calcium did not show significant difference between groups. CONCLUSION: According to this study, TUS, applied with these parameters (not commonly used for bone therapy) accelerates bone healing, confirmed by radiography, yet the biochemical analysis was not conclusive. One reason for this inconsistency may have been some inadequacy of the biochemical protocol, currently under investigation. Level of Evidence II, Prospective comparative study. PMID:24453637

  9. [Mechanism of low intensity ultrasound effect on mitochondria].

    PubMed

    Selivanov, V A; Zinchenko, V P; Sarvazian, A P

    1982-01-01

    Ultrasound of 0,2 Wt/cm2 intensity affects the ionic transport across the mitochondrial membrane in vitro. In the presence of 1 mM EGTA in the incubation medium ultrasound slows down K+ exit into the external medium after the addition of an uncoupling agent (2,4-dinitrophenol). With the addition of 100 divided by 400 mM Ca2+ to the starting medium ultrasound makes the amount of Ca2+ absorbed by mitochondrial decrease and the rate of Ca2+/H+ electroneutral exchange increase. Without Ca2+ ultrasound does not influence the rate of coupled and 2,4-dinitrophenol uncoupled respiration and oxidative phosphorylation, i.e. does not produce strong functional changes.

  10. Hemostatic Effects of Microbubble-Enhanced Low-Intensity Ultrasound in a Liver Avulsion Injury Model

    PubMed Central

    Feng, Guiying; Liu, Jianhua; Zhao, Xiaochen; Wei, Jinglu; Ou, Wencai; Xiao, Shuyi; Hu, Zhiwen; Wei, Hongqin; Liu, Zheng

    2014-01-01

    Objectives Microbubble-enhanced therapeutic ultrasound (MEUS) can block the blood flow in the organs. The aim of this study was to evaluate the hemostatic effect of microbubble-enhanced pulsed, low-intensity ultrasound in a New Zealand White rabbit model of avulsion trauma of the liver. The therapeutic ultrasound (TUS) transducer was operated with the frequency of 1.2 MHz and an acoustic pressure of 3.4 MPa. Microbubble-(MB) enhanced ultrasound (MEUS) (n = 6) was delivered to the distal part of the liver where the avulsion was created. Livers were treated by TUS only (n = 4) or MB only (n = 4) which served as controls. Bleeding rates were measured and contrast enhanced ultrasound (CEUS) was performed to assess the hemostatic effect, and liver hemoperfusion before and after treatment. Generally, bleeding rates decreased more than 10-fold after the treatment with MEUS compared with those of the control group (P<0.05). CEUS showed significant declines in perfusion. The peak intensity value and the area under the curve also decreased after insonation compared with those of the control group (P<0.05). Histological examination showed cloudy and swollen hepatocytes, dilated hepatic sinusoids, perisinusoidal spaces with erythrocyte accumulation in small blood vessels, obvious hemorrhage around portal areas and scattered necrosis in liver tissues within the insonation area of MEUS Group. In addition, necrosis was found in liver tissue 48 h after insonation. We conclude that MEUS might provide an effective hemostatic therapy for serious organ trauma such as liver avulsion injury. PMID:24788757

  11. Remodeling of chromatin under low intensity diffuse ultrasound.

    PubMed

    Noriega, Sandra; Budhiraja, Gaurav; Subramanian, Anuradha

    2012-08-01

    A variety of mechanotransduction pathways mediate the response of fibroblasts or chondrocytes to ultrasound stimulation. In addition, regulatory pathways that co-ordinate stimulus-specific cellular responses are likely to exist. In this study, analysis was confined to the hypothesis that ultrasound stimulation (US) influences the chromatin structure, and that these changes may reflect a regulatory pathway that connects nuclear architecture, chromatin structure and gene expression. Murine fibroblasts seeded on tissue culture plates were stimulated with US (5.0 MHz (14 kPa), 51-s per application) and the thermal denaturation profiles of nuclei isolated from fibroblasts were assessed by dynamic scanning calorimetry (DSC). When compared to the thermal profiles obtained from the nuclei of non-stimulated cells, the nuclei obtained from stimulated cells showed a change in peak profiles and peak areas, which is indicative of chromatin remodeling. Independently, US was also observed to impact the histone (H1):chromatin association as measured indirectly by DAPI staining. Based on our work, it appears plausible that US can produce a remodeling of chromatin, thus triggering signal cascade and other intracellular mechanisms.

  12. Pilot Clinical Studies of Long Duration, Low Intensity Therapeutic Ultrasound for Osteoarthritis.

    PubMed

    Langer, Matthew D; Levine, Vanessa; Taggart, Rebecca; Lewis, George K; Hernandez, Lyndon; Ortiz, Ralph

    2014-04-01

    Osteoarthritis is one of the leading causes of disability in the aging population. Long duration, low intensity therapeutic ultrasound has had promising impact in animal models to slow the progression of the disease and provide joint relief. Two pilot studies were conducted using a novel, wearable platform for delivering ultrasound to evaluate the potential clinical benefits of ultrasound therapy on knee osteoarthritis. There was a pain reduction effect from using ultrasound, as high as fifty two percent in one study. As well, initial data demonstrates that mobility may be increased for patients experiencing mild to moderate arthritis of the knee.

  13. A prototype stimulator system for noninvasive Low Intensity Focused Ultrasound delivery.

    PubMed

    Mulgaonkar, Amit P; Singh, Rahul S; Babakhanian, Meghedi; Culjat, Martin O; Grundfest, Warren S; Gorgulho, Alessandra; Lacan, Goran; De Salles, Antonio A F; Bystritsky, Alexander; Melega, William P

    2012-01-01

    A prototype Low Intensity Focused Ultrasound (LIFU) stimulator system was developed to evaluate non-invasive neuromodulation in a large animal model. We conducted a feasibility study on a Göttingen minipig, demonstrating reversible, targeted transcranial neuromodulation. The hypothalamus of the minipig was repeatedly stimulated with LIFU which evoked temporally correlated increases in both heart rate and blood pressure.

  14. Low Intensity Uniform Ultrasound Accelerates Enzymatic Hydrolysis of Cellulose Plant Matter

    USDA-ARS?s Scientific Manuscript database

    The work reported here is based on acceleration of enzymatic hydrolysis of plant biomass substrate by introduction of low intensity, uniform ultrasound field into a reaction chamber (bio-reactor). This method may serve as an improvement of rates in the hydrolysis of cellulosic materials to sugars, ...

  15. Accurate acoustic power measurement for low-intensity focused ultrasound using focal axial vibration velocity

    NASA Astrophysics Data System (ADS)

    Tao, Chenyang; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong; Hu, Jimin

    2017-07-01

    Low-intensity focused ultrasound is a form of therapy that can have reversible acoustothermal effects on biological tissue, depending on the exposure parameters. The acoustic power (AP) should be chosen with caution for the sake of safety. To recover the energy of counteracted radial vibrations at the focal point, an accurate AP measurement method using the focal axial vibration velocity (FAVV) is proposed in explicit formulae and is demonstrated experimentally using a laser vibrometer. The experimental APs for two transducers agree well with theoretical calculations and numerical simulations, showing that AP is proportional to the square of the FAVV, with a fixed power gain determined by the physical parameters of the transducers. The favorable results suggest that the FAVV can be used as a valuable parameter for non-contact AP measurement, providing a new strategy for accurate power control for low-intensity focused ultrasound in biomedical engineering.

  16. Effects of Low-Intensity Continuous Ultrasound on Hematological Parameters of Rats

    PubMed Central

    Mehrpour, M.; Shakeri-Zadeh, A.; Basir, P.; Jamei, B.; Ghaheri, H.; Shiran, M.B.

    2016-01-01

    Background: Low intensity ultrasound (US) has some well-known bio-effects which are of great importance to be considered. Objective: We conducted the present study to investigate the effects of low intensity continuous ultrasound on blood cells count in rat. Methods: Rats were anesthetized and blood samples were collected before US exposure. Then, they were exposed to US with nominal intensity of 0.2 W/cm2 at frequency of 3 MHz for a period of 10 minutes and this protocol was repeated for 7 days. Twenty four hours after the last US exposure, secondary blood samples were collected and the changes in blood parameters were evaluated. Results: Analysis revealed that platelets, hematocrit (HCT) and hemoglobin (HGB) were significantly different between experimental and sham groups but no difference between sham and control groups was observed. The results show that HCT and HGB of exposed rats were significantly reduced. Conclusion: This study shows that low intensity US may lead to side effects for hematological parameters such as reduction in the levels of HGB and HCT. PMID:27853727

  17. Electrophysiological Source Imaging of Brain Networks Perturbed by Low-intensity Transcranial Focused Ultrasound

    PubMed Central

    Yu, Kai; Sohrabpour, Abbas

    2016-01-01

    Objective Transcranial focused ultrasound (tFUS) has been introduced as a noninvasive neuromodulation technique with good spatial selectivity. We report an experimental investigation to detect noninvasive electrophysiological response induced by low-intensity tFUS in an in vivo animal model, and perform electrophysiological source imaging (ESI) of tFUS-induced brain activity from noninvasive scalp EEG recordings. Methods A single ultrasound transducer was used to generate low-intensity tFUS (Ispta<1 mW/cm2) and induce brain activation at multiple selected sites in an in vivo rat model. Up to 16 scalp electrodes were used to record tFUS-induced EEG. Event related potentials (ERPs) were analyzed in time, frequency, and spatial domains. Current source distributions were estimated by ESI to reconstruct spatio-temporal distributions of brain activation induced by tFUS. Results Neuronal activation was observed following low-intensity tFUS, as correlated to tFUS intensity and sonication duration. ESI revealed initial focal activation in cortical area corresponding to tFUS stimulation site, and the activation propagating to surrounding areas over time. Conclusion The present results demonstrate the feasibility of noninvasively recording brain electrophysiological response in vivo following low-intensity tFUS stimulation, and the feasibility of imaging spatio-temporal distributions of brain activation as induced by tFUS in vivo. Significance The present approach may lead to a new means of imaging brain activity using tFUS perturbation and a closed-loop ESI-guided tFUS neuromodulation modality. PMID:27448335

  18. Enhancement of ANAMMOX activity by low-intensity ultrasound irradiation at ambient temperature.

    PubMed

    Yu, Jin-Jin; Chen, Hui; Zhang, Jue; Ji, Yu-Xin; Liu, Qi-Zhen; Jin, Ren-Cun

    2013-08-01

    This paper aims to investigate the enhancement effect of low intensity intermittent ultrasound irradiation on the efficiency of anaerobic ammonium oxidation (ANAMMOX) process at ambient temperature. With intermittently irradiated (ultrasound intensity of 0.19 w/cm(2), exposure time of 0.2 min), the reactor (RU) had a nitrogen removal rate (NRR) of 5.49 kgTN/m(3)/d at 14.8°C, while the NRR was 1.53 kgTN/m(3)/d in the control reactor (RC). At the end of operation, the contents of polysaccharide, protein, TTC-dehydrogenase and VSS were 6.82 mg/mgVSS, 26.79 mg/mgVSS, 0.58 mgTF/L/H and 10.11 gVSS/L in RU, higher than the levels in the RC. These results demonstrated that it is possible to achieve stable and highly efficient operation in an ANAMMOX reactor at low ambient temperature by implementation of ultrasonication.

  19. Remote excitation of neuronal circuits using low-intensity, low-frequency ultrasound.

    PubMed

    Tyler, William J; Tufail, Yusuf; Finsterwald, Michael; Tauchmann, Monica L; Olson, Emily J; Majestic, Cassondra

    2008-01-01

    Possessing the ability to noninvasively elicit brain circuit activity yields immense experimental and therapeutic power. Most currently employed neurostimulation methods rely on the somewhat invasive use of stimulating electrodes or photon-emitting devices. Due to its ability to noninvasively propagate through bone and other tissues in a focused manner, the implementation of ultrasound (US) represents a compelling alternative approach to current neuromodulation strategies. Here, we investigated the influence of low-intensity, low-frequency ultrasound (LILFU) on neuronal activity. By transmitting US waveforms through hippocampal slice cultures and ex vivo mouse brains, we determined LILFU is capable of remotely and noninvasively exciting neurons and network activity. Our results illustrate that LILFU can stimulate electrical activity in neurons by activating voltage-gated sodium channels, as well as voltage-gated calcium channels. The LILFU-induced changes in neuronal activity were sufficient to trigger SNARE-mediated exocytosis and synaptic transmission in hippocampal circuits. Because LILFU can stimulate electrical activity and calcium signaling in neurons as well as central synaptic transmission we conclude US provides a powerful tool for remotely modulating brain circuit activity.

  20. In vitro cell system for studying molecular mechanisms of action associated with low intensity focused ultrasound

    NASA Astrophysics Data System (ADS)

    Babakhanian, Meghedi; Fan, Richard E.; Mulgaonkar, Amit P.; Singh, Rahul; Culjat, Martin O.; Danesh, Shahab M.; Toro, Ligia; Grundfest, Warren; Melega, William P.

    2012-03-01

    Low intensity focused ultrasound (LIFU) is now being considered as a noninvasive brain therapy for clinical applications. We maintain that LIFU can efficiently deliver energy from outside the skull to target specific brain regions, effecting localized neuromodulation. However, the underlying molecular mechanisms that drive this LIFU-induced neuromodulation are not well-defined due, in part, to our lack of understanding of how particular sets of LIFU delivery parameters affect the outcome. To efficiently conduct multiple sweeps of different parameters and determine their effects, we have developed an in-vitro system to study the effects of LIFU on different types of cells grown in culture. Presently, we are evaluating how LIFU affects the ionic flux that may underlie neuronal excitation and inhibition observed in-vivo. The results of our in-vitro studies will provide a rationale for selection of optimal LIFU parameter to be used in subsequent in-vivo applications. Thus, a prototype ultrasound cell assay system has been developed to conduct these studies, and is described in this work.

  1. Low-intensity focused ultrasound mediated localized drug delivery for liver tumors in rabbits.

    PubMed

    Gong, Yuping; Wang, Zhigang; Dong, Guifang; Sun, Yang; Wang, Xi; Rong, Yue; Li, Maoping; Wang, Dong; Ran, Haitao

    2016-09-01

    To explore the antitumor effects of low-intensity focused ultrasound (LIFU) mediated localized drug delivery of adriamycin-microbubble-PLGA nanoparticle complexes on rabbits VX2 liver tumor. ADM-NMCs were prepared by covalent linking of ADM-PLGA nanoparticles (ADM-NPs) to the shell of the microbubbles. A fixed water bag filled with microbubbles was subjected to LIFU and non-focused ultrasound respectively, and the ultrasound images of which were recorded before and after ultrasonication. A total of 54 VX2 liver tumor-burdened rabbits were divided into six groups randomly, including control, ADM-NPs combined with LIFU, microbubbles combined with LIFU, ADM-NPs and microbubbles combined with LIFU, ADM-NMCs combined with LIFU and ADM-NMCs combined with Non-FUS. The tumor volume and volume inhibition rate (VIR) of tumor progression were calculated and compared. Apoptotic cells were labeled by terminal deoxyuridine nick end. Proliferating cell nuclear antigen was detected by immunohistochemistry. The median survival time of the animals were recorded and compared. ADM-NMCs were successfully prepared with an average diameter of 1721 nm. The highest VIR and apoptotic index (AI) were found in the group of ADM-NMCs combined with LIFU while the lowest proliferating index (PI) was simultaneously observed in this group. The median survival time of the rabbits in the ADM-NMCs combined with LIFU group was the longest (71days) among all groups. ADM-NMCs combined with LIFU could inhibit the rabbits VX2 liver tumor progress by delaying the tumor proliferation and accelerating apoptosis, which presents a novel process for liver tumor targeting chemotherapy.

  2. Evaluation of the potential clinical application of low-intensity ultrasound stimulation for preventing osteoporotic bone fracture.

    PubMed

    Woo, Dae Gon; Ko, Chang-Yong; Kim, Han Sung; Seo, Jong Bum; Lim, Dohyung

    2010-07-01

    This study evaluated the possible clinical application of low-intensity ultrasound (LIUS) stimulation for preventing osteoporotic bone fracture. Eight virgin 14-week-old ICR mice (weight 24.0 +/- 0.7 g) were ovariectomized to induce osteoporosis. The right hind limbs (US limbs) were stimulated with LIUS, whereas the left hind limbs (CON limbs) were not stimulated. LIUS was applied for 20 min a day, 5 days a week over a 6-week period using the following parameters: 1.5 MHz frequency, 1.0 kHz pulse repetition, 30 mW/cm(2) intensity, and 200 mus pulse length. The effective structural modulus increased significantly (p < 0.05) in the US limbs over time with the increased bone quantity, whereas that in CON limbs remained statistically constant (p > 0.05). In addition, the elastic modulus in the US limbs was generally enhanced by an increased bone quality, compared with the CON limbs. Therefore, LIUS stimulation may effectively reduce the risk of osteoporotic bone fracture by increasing the mechanical characteristics of bone via improvements in both the effective structural and elastic modulus of the osteoporotic bone. In conclusion, LIUS may potentially prove very effective clinically for preventing osteoporotic bone fractures.

  3. Numerical studies of the spectrum of low-intensity ultrasound scattered by bubbles

    NASA Astrophysics Data System (ADS)

    Eatock, B. C.; Nishi, R. Y.; Johnston, G. W.

    1985-05-01

    The magnitude of the nonlinear effect in the scattering of ultrasound by nitrogen bubbles in water is examined numerically, for ultrasonic frequencies and amplitudes typical of diagnostic medical devices, to determine the suitability of this effect for the detection of bubbles in blood or tissue for application in decompression research. Numerical solutions of the modified 'Rayleigh' equation, including the effects of acoustic, thermal, and viscous damping, and the dependence of the polytropic exponent on frequency are presented for pulsed ultrasound. For the chosen conditions, it is shown that nonlinear scattering is significant only for the population of bubbles which are smaller than, or close to, resonance size, and primarily for those bubbles that are one-half resonance size.

  4. Modeling linear vibration of cell nucleus in low intensity ultrasound field.

    PubMed

    Or, Meir; Kimmel, Eitan

    2009-06-01

    Therapeutic ultrasound of low to medium intensity is known to induce alterations in structure and functioning of cells and tissues, both in vivo and in vitro. Such effects, including excitation or inhibition of action potentials, enhanced angiogenesis rate, increased membrane permeability and changes in molecular expression, cannot be attributed in many cases to rising temperatures or the presence of gas bubbles. This study attempts to find a possible alternative explanation for the cases where neither thermal effects nor cavitation mechanisms count. We focus our attention on the complex and dense structure of cell cytoplasm, looking for periodic separating forces and relative motion between intracellular elements, such as the nucleus, and the structure in which they are embedded. It is hypothesized that relative oscillatory displacements between intracellular elements of different densities might appear in cells in response to low intensity therapeutic ultrasound (LITUS). Those displacements might induce alterations in cell structure and functioning. A linear model is constructed and solved for a spherical object, representing a typical organelle such as the nucleus, within a homogenous viscoelastic medium that vibrates uniformly. The structure in which the object is embedded is described by four different rheologic models, including viscous fluid, elastic solid, and Voigt and Maxwell viscoelastic constructs. It is found that cyclic intracellular displacements comparable with and even larger than the mean thermal fluctuations may be obtained due to LITUS irradiation in conditions where the relative motion of organelles is dominated by elastic response, or where the effective viscosity of the cytoplasm is low. Resonance frequency at which intracellular vibration of maximal amplitude is obtained is found to lie within the low LITUS frequency range, i.e., tens to hundreds of kHz. Local intracellular strain on the order of 0.5% is found for 1 microm organelle in 10

  5. Low intensity ultrasound inhibits brain oedema formation in rats: potential action on AQP4 membrane localization.

    PubMed

    Karmacharya, Mrigendra Bir; Kim, Kil Hwan; Kim, See Yoon; Chung, Joonho; Min, Byoung-Hyun; Park, So Ra; Choi, Byung Hyune

    2015-06-01

    Brain oedema is a major contributing factor to the morbidity and mortality of a variety of brain disorders. Although there has been considerable progress in our understanding of pathophysiological and molecular mechanisms associated with brain oedema so far, more effective treatment is required and is still awaited. Here we intended to study the effects of low intensity ultrasound (LIUS) on brain oedema. We prepared the rat hippocampal slice in vitro and acute water intoxication in vivo models of brain oedema. We applied LIUS stimulation in these models and studied the molecular mechanisms of LIUS action on brain oedema. We found that LIUS stimulation markedly inhibited the oedema formation in both of these models. LIUS stimulation significantly reduced brain water content and intracranial pressure resulting in increased survival of the rats. Here, we showed that the AQP4 localization was increased in the astrocytic foot processes in the oedematous hippocampal slices, while it was significantly reduced in the LIUS-stimulated hippocampal slices. In the in vivo model too, AQP4 expression was markedly increased in the microvessels of the cerebral cortex and hippocampus after water intoxication but was reduced in the LIUS-stimulated rats. These data show that LIUS has an inhibitory effect on cytotoxic brain oedema and suggest its therapeutic potential to treat brain oedema. We propose that LIUS reduces the AQP4 localization around the astrocytic foot processes thereby decreasing water permeability into the brain tissue. © 2014 British Neuropathological Society.

  6. Structural and permeability sensitivity of cells to low intensity ultrasound: Infrared and fluorescence evidence in vitro.

    PubMed

    Domenici, Fabio; Giliberti, Claudia; Bedini, Angelico; Palomba, Raffaele; Udroiu, Ion; Di Giambattista, Lucia; Pozzi, Deleana; Morrone, Stefania; Bordi, Federico; Congiu Castellano, Agostina

    2014-04-01

    This work is focused on the in vitro study of the effects induced by medical ultrasound (US) in murine fibroblast cells (NIH-3T3) at a low-intensity of exposure (spatial peak temporal average intensity Ita<0.1Wcm(-2)). Conventional 1MHz and 3MHz US devices of therapeutic relevance were employed with varying intensity and exposure time parameters. In this framework, upon cells exposure to US, structural changes at the molecular level were evaluated by infrared spectroscopy; alterations in plasma membrane permeability were monitored in terms of uptake efficiency of small cell-impermeable model drug molecules, as measured by fluorescence microscopy and flow cytometry. The results were related to the cell viability and combined with the statistical PCA analysis, confirming that NIH-3T3 cells are sensitive to therapeutic US, mainly at 1MHz, with time-dependent increases in both efficiency of uptake, recovery of wild-type membrane permeability, and the size of molecules entering 3T3. On the contrary, the exposures from US equipment at 3MHz show uptakes comparable with untreated samples.

  7. Apoptosis induced by low-intensity ultrasound in vitro: Alteration of protein profile and potential molecular mechanism

    NASA Astrophysics Data System (ADS)

    Feng, Yi; Wan, Mingxi

    2017-03-01

    To analyze the potential mechanism related to the apoptosis induced by low intensity focused ultrasound, comparative proteomic method was introduced in the study. After ultrasound irradiation (3.0 W/cm2, 1 minute, 6 hours incubation post-irradiation), the human SMMC-7721 hepatocarcinoma cells were stained by trypan blue to detect the morphologic changes, and then the percentage of early apoptosis were tested by the flow cytometry with double staining of FITC-labelled Annexin V/Propidium iodide. Two-dimensional SDS polyacrylamide gel electrophoresis was used to get the protein profile and some proteins differently expressed after ultrasound irradiation were identified by MALDI-TOF mass spectrometry. It's proved early apoptosis of cells were induced by low intentisy focused ultrasound. After ultrasound irradiation, the expressing characteristics of several proteins changed, in which protein p53 and heat shock proteins are associated with apoptosis initiation. It is suggested that the low-intensity ultrasound-induced apoptotic cancer therapy has the potential application via understanding its relevant molecular signaling and key proteins. Moreover, the comparative proteomic method is proved to be useful to supply information about the protein expression to analyze the metabolic processes related to bio-effects of biomedical ultrasound.

  8. Low intensity ultrasound induces apoptosis via MPT channel on mitochondrial membrane: Target for regulating cancer therapy or not?

    NASA Astrophysics Data System (ADS)

    Feng, Yi; Wan, Mingxi

    2017-03-01

    To discuss how the mitochondrion is involved in low intensity ultrasound induced apoptosis, HepG2 cells were irradiated by low intensity focused ultrasound (ISPTA = 3W/cm2, 1 min) and then cultured from 3-12 h post irradiation in the study. The morphological alteration was examined by light and fluorescent microscopy respectively. Cell viability and apoptosis were examined by trypan blue staining and flow cytometry with double staining of FITC-labelled Annexin-V/PI. Key proteins responded to irradiation were screened out by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and shotgun proteomic methods with Agilent 1100 HPLC-Chip-MS technology. Representative apoptotic morphological characteristics and increased percentage of apoptotic cells were achieved. Six important proteins (4 up-regulated and 2 down-regulated) were selected and analyzed. It revealed low intensity focused ultrasound could induce apoptosis in HepG2 cells and the US-induced apoptosis was mitochondria-dependent and caspases-dependent. Moreover, mitochondrial membrane permeability transition (MPT) is related to ultrasound induced apoptosis, but VDAC may be not the main MPT channel. Understanding it could help to assist the cancer therapy by regulating the MPT as the target.

  9. Linear alkyl benzene sulphonate (LAS) degradation by immobilized Pseudomonas aeruginosa under low intensity ultrasound.

    PubMed

    Lijun, Xiang; Bochu, Wang; Zhimin, Li; Chuanren, Duan; Qinghong, Wang; Liu, Liu

    2005-01-15

    We studied the LAS degradation of immobilized Pseudomonas aeruginosa with low-intensity ultrasonic and the influence of original LAS concentration, pH, rotary velocity and different conditions of low-intensity ultrasonic irradiation on the degradation of LAS. In our experiment, the degradation rate of LAS was the main index. We found that low-intensity ultrasonic irradiation could improve the metabolism of microorganism cells and promote the LAS biodegradation of immobilized cells. In the experiment, 50 mg/l LAS were used to simulate wastewater, and low-intensity ultrasonic was considered. We found the influence was obvious, and the optimal degradation rate was acquired when the conditions of ultrasonic were frequency 24 kHz, power 8 W, stimulation time 5 s, intermissive time 30 s, and total time 10 min. The LAS degradation rate of immobilized cells with ultrasonic were respectively 40% and 9.5% higher than that of the suspending cells and immobilized cells without irradiation.

  10. Induction of Apoptosis in U937 Cells by Using a Combination of Bortezomib and Low-Intensity Ultrasound

    PubMed Central

    Saliev, Timur; Feril, Loreto B.; Ogawa, Koichi; Watanabe, Akiko; Begimbetova, Dinara; Molkenov, Askhat; Alimbetov, Dauren; Tachibana, Katsuro

    2016-01-01

    Background We scrutinized the feasibility of apoptosis induction in blood cancer cells by means of low-intensity ultrasound and the proteasome inhibitor bortezomib (Velcade). Material/Methods Human leukemic monocyte lymphoma U937 cells were subjected to ultrasound in the presence of bortezomib and the echo contrast agent Sonazoid. Two types of acoustic intensity (0.18 W/cm2 and 0.05 W/cm2) were used for the experiments. Treated U937 cells were analyzed for viability and levels of early and late apoptosis. In addition, scanning electron microscopy analysis of treated cells was performed. Results The percentage of cells that underwent early apoptosis in the group treated with ultrasound and Sonazoid was 8.0±1.31% (intensity 0.18 W/cm2) and 7.0±1.69% (0.05 W/cm2). However, coupling of bortezomib and Sonazoid resulted in an increase in the percentage of cells in the early apoptosis phase, up to 32.50±3.59% (intensity 0.18 W/cm2) and 33.0±4.90% (0.05 W/cm2). The percentage of U937 cells in the late apoptosis stage was not significantly different from that in the group treated with bortezomib only. Conclusions Our findings indicate the feasibility of apoptosis induction in blood cancer cells by using a combination of bortezomib, ultrasound contrast agents, and low-intensity ultrasound. PMID:28003640

  11. Effects of carbon-nitrogen ratio on nitrogen removal in a sequencing batch reactor enhanced with low-intensity ultrasound.

    PubMed

    Jin, Ruofei; Liu, Guangfei; Li, Chunling; Xu, Rongjuan; Li, Hongyang; Zhang, Lunxiang; Zhou, Jiti

    2013-11-01

    A sequencing batch reactor (SBR) enhanced with low-intensity ultrasound was designed to study the removal of nitrogen under different carbon-nitrogen (C/N) ratios. The results showed that the removal efficiencies of CODCr and nitrogen were inversely proportional to C/N ratios. The CODCr of the effluent in the control reactor (CR) and the low-intensity ultrasound-enhanced reactor (UER) were lower than 40 mg L(-1). With a decrease in C/N ratio, the NH4(+)-N removal load of the CR showed little change, while the NH4(+)-N removal load of UER increased from 21.2 to 56.1mg NH4(+)-N/g mixed liquid suspended solids per day. To further understand effects of low-intensity ultrasound, the denaturing gel gradient electrophoresis (DGGE) analysis showed that the similar coefficients of the community structures in the UER and CR were 86%, 52% and 29% when the C/N ratios were 15:1, 10:1, 5:1, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. [Effect of low-intensity ultrasound on endothelin-1 and nitrogen monoxide in uterine tissues of SD rats following abortion].

    PubMed

    Zhang, Yanxia; Guo, Jufang; Lin, Chuan; Lu, Lu; Li, Chengzhi

    2014-01-01

    To investigate the effect of low-intensity ultrasound on the contents of endothelin (ET-1) and nitrogen monoxide (NO) in uterine tissues of SD rats after abortion. Thirty female pregnant rats were randomly divided into treatment group and control group and received mifepristone and misoprostol to induce abortion. The rats in the treatment group were treated by low-intensity ultrasound for 30 min/day for 5 consecutive days, and those in the control group received sham treatment. The uterine tissue was then taken and homogenized for measurement of ET-1 and NO contents using enzyme-linked immunosorbent assay and chemical testing. ET-1 content in the uterine tissues was significantly higher in the treatment group than in the control group (P<0.05), but NO content showed no significant difference between the two groups (P>0.05). Low-intensity ultrasound can promote the contraction of uterine smooth muscles by increasing the level of ET-1 to modulate the homeostasis of ET-1 and NO.

  13. Caveolin-1 Mediates Low-Intensity Ultrasound-Induced Apoptosis via Downregulation of Signal Transducer and Activator of Transcription 3 Phosphorylation in Laryngeal Carcinoma Cells.

    PubMed

    Ye, Qingsheng; Meng, Cuida; Shen, Yannan; Ji, Jianjun; Wang, Xiaochun; Zhou, Sheng; Jia, Lili; Wang, Yanqun

    2016-09-01

    Low-intensity ultrasound therapy has been found to be a potential tool in the management of malignant tumors in recent years. However, the molecular mechanism underlying low-intensity ultrasound-induced apoptosis is still not clear. In this study, we investigated the effects of low-intensity ultrasound-induced apoptosis in HEp-2 cells. We found that low-intensity ultrasound significantly induced apoptosis, and the expression level of caveolin-1 (Cav-1) was dramatically increased after ultrasound treatment of HEp-2 cells. After inhibiting the expression level of Cav-1 using siRNA transfection, we found that the cellular apoptosis induced by low-intensity ultrasound was significantly suppressed. In addition, inhibition of Cav-1 expression promoted phosphorylation of signal transducer and activator of transcription 3 (STAT3), suggesting that the STAT3 signaling pathway was involved in low-intensity ultrasound-induced apoptosis via Cav-1 regulation. Our results indicate that Cav-1/STAT3 signaling pathway may mediate low-intensity ultrasound-induced apoptosis, and this technology could potentially be used clinically for the treatment of cancers.

  14. Sustained acoustic medicine: a novel long duration approach to biomodulation utilizing low intensity therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Langer, Matthew D.; Lewis, George K.

    2015-05-01

    Therapeutic ultrasound is an established technique for biomodulation used by physical therapists. Typically it is used to deliver energy locally for the purpose of altering tissue plasticity and increasing local circulation. Access to ultrasound therapy has been limited by equipment and logistic requirements, which has reduced the overall efficacy of the therapy. Ultrasound miniaturization allows for development of portable, wearable, self-applied ultrasound devices that sidestep these limitations. Additionally, research has shown that the timescale of acoustic stimulation matters, and directly affects the quality of result. This paper describes a novel, long duration approach to therapeutic ultrasound and reviews the current data available for a variety of musculoskeletal conditions.

  15. Chronic exposure to pulsed low-intensity microwaves is carcinogenic and tumorogenic

    NASA Astrophysics Data System (ADS)

    Lundquist, Marjorie

    2004-03-01

    To study health effects of lifetime exposure to low-intensity pulsed radiation >890 MHz, one controlled laboratory study of SPF* rats[1-3] and two of mice[4,5] were conducted, but only one[4] reported that its data showed an association between irradiation and cancer; reports of the other two studies minimized or denied such association. Critical review of these identified data evaluation errors; their correction enables a conclusion of microwave carcinogenicity from each study (the rat study also shows an association with endocrine-system primary malignancies and with a benign tumor of the adrenal medulla), enhancing the credibility of an epidemiological study[6] reporting a brain cancer risk for users of both analog and digital cellular phones. [1] J. Raloff. Science News 126(7):103(1984). [2] K. R. Foster & A. W. Guy. Sci Am 255(3):32-39(1986). [3] C.-K. Chou et al. Bioelectromagnetics 13:469-496(1992). [4] M. H. Repacholi et al. Radiat Res 147:631-640(1990)SPF\\. [5] T. D. Utteridge et al. Radiat Res 158:357-364(2002)non-SPF\\. [6] L. Hardell et al. Int J Oncol 22:399-407(2003). * SPF = specific-pathogen-free

  16. Effects of low-intensity ultrasound on the growth, cell membrane permeability and ethanol tolerance of Saccharomyces cerevisiae.

    PubMed

    Dai, Chunhua; Xiong, Feng; He, Ronghai; Zhang, Weiwei; Ma, Haile

    2017-05-01

    Effects of low-intensity ultrasound (at different frequency, treatment time and power) on Saccharomyces cerevisiae in different growth phase were evaluated by the biomass in the paper. In addition, the cell membrane permeability and ethanol tolerance of sonicated Saccharomyces cerevisiae were also researched. The results revealed that the biomass of Saccharomyces cerevisiae increased by 127.03% under the optimum ultrasonic conditions such as frequency 28kHz, power 140W/L and ultrasonic time 1h when Saccharomyces cerevisiae cultured to the latent anaphase. And the membrane permeability of Saccharomyces cerevisiae in latent anaphase enhanced by ultrasound, resulting in the augment of extracellular protein, nucleic acid and fructose-1,6-diphosphate (FDP) contents. In addition, sonication could accelerate the damage of high concentration alcohol to Saccharomyces cerevisiae although the ethanol tolerance of Saccharomyces cerevisiae was not affected significantly by ultrasound.

  17. Development of a Cancer Treatment with the Concomitant Use of Low-Intensity Ultrasound: Entering the Age of Simultaneous Diagnosis and Treatment

    PubMed Central

    Emoto, Makoto

    2014-01-01

    In recent years, studies using ultrasound energy for cancer treatment have advanced, thus revealing the enhancement of drug effects by employing low-intensity ultrasound. Furthermore, anti-angiogenesis against tumors is now attracting attention as a new cancer treatment. Therefore, we focused on the biological effects and the enhancement of drug effects brought by this low-intensity ultrasound energy and reported on the efficacy against a uterine sarcoma model, by implementing the basic studies, for the first time, including the concomitant use of low-intensity ultrasound irradiation, as an expected new antiangiogenic therapy for cancer treatment. Furthermore, we have succeeded in simultaneously utilizing low-intensity ultrasound in both diagnosis and treatment, upon real time evaluation of the anti-tumor effects and anti-angiogenesis effects using color Doppler ultrasound imaging. Although the biological effects of ultrasound have not yet been completely clarified, transient stomas were formed (Sonoporation) in cancer cells irradiated by low-intensity ultrasound and it is believed that the penetration effect of drugs is enhanced due to the drug being more charged inside the cell through these stomas. Furthermore, it has become clear that the concomitant therapy of anti-angiogenesis drugs and low-intensity ultrasound blocks the angiogenic factor VEGF produced by cancer cells, inhibits the induction of circulating endothelial progenitor cells in the bone marrow, and expedites angiogenic inhibitor TSP-1. Based on research achievements in recent years, we predict that the current diagnostic device for color Doppler ultrasound imaging will be improved in the near future, bringing with it the arrival of an age of “low-intensity ultrasound treatment that simultaneously enables diagnosis and treatment of cancer in real time.” PMID:26852677

  18. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network

    PubMed Central

    Xing, Jida; Chen, Jie

    2015-01-01

    In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared to our previous

  19. Design of a Thermoacoustic Sensor for Low Intensity Ultrasound Measurements Based on an Artificial Neural Network.

    PubMed

    Xing, Jida; Chen, Jie

    2015-06-23

    In therapeutic ultrasound applications, accurate ultrasound output intensities are crucial because the physiological effects of therapeutic ultrasound are very sensitive to the intensity and duration of these applications. Although radiation force balance is a benchmark technique for measuring ultrasound intensity and power, it is costly, difficult to operate, and compromised by noise vibration. To overcome these limitations, the development of a low-cost, easy to operate, and vibration-resistant alternative device is necessary for rapid ultrasound intensity measurement. Therefore, we proposed and validated a novel two-layer thermoacoustic sensor using an artificial neural network technique to accurately measure low ultrasound intensities between 30 and 120 mW/cm2. The first layer of the sensor design is a cylindrical absorber made of plexiglass, followed by a second layer composed of polyurethane rubber with a high attenuation coefficient to absorb extra ultrasound energy. The sensor determined ultrasound intensities according to a temperature elevation induced by heat converted from incident acoustic energy. Compared with our previous one-layer sensor design, the new two-layer sensor enhanced the ultrasound absorption efficiency to provide more rapid and reliable measurements. Using a three-dimensional model in the K-wave toolbox, our simulation of the ultrasound propagation process demonstrated that the two-layer design is more efficient than the single layer design. We also integrated an artificial neural network algorithm to compensate for the large measurement offset. After obtaining multiple parameters of the sensor characteristics through calibration, the artificial neural network is built to correct temperature drifts and increase the reliability of our thermoacoustic measurements through iterative training about ten seconds. The performance of the artificial neural network method was validated through a series of experiments. Compared to our previous

  20. Study to evaluate the effect of low-intensity pulsed electrical currents on levels of oedema in chronic non-healing wounds.

    PubMed

    Young, S; Hampton, S; Tadej, M

    2011-08-01

    To evaluate the efficacy of a medical device, Accel-Heal, which generates a low-intensity pulsed direct current, on the management of oedema in chronic leg ulcers, using high-frequency diagnostic ultrasound. High-frequency diagnostic ultrasound (20MHz) with an axial resolution of 60um was used to assess the effect of an electrical stimulation device delivering a low-intensity pulsed current on levels of oedema in chronic non-healing venous and mixed aetiology leg ulcers for a period of 10 days. Thirty patients' wounds were monitored over a 3-month period, during which time changes in levels of oedema in the wound bed and surrounding tissues were imaged and measured. A significant fall in the, previously high level, of periwound oedema was noted in the patient population after 10 days of device application. By 20 days after the first application of the device the level of periwound oedema had decreased by approximately 60% of the original level, which was maintained up to the 90-day follow-up. Occurring in parallel with this, scans of the wound bed showed a rapid decrease in the levels of oedema as the new wound matrix was laid down. The electrical stimulation device appeared to be effective in reducing oedema levels in a range of chronic wounds and their surrounding tissues. The study was funded by a grant from Synapse micro-current Ltd.

  1. Low intensity and frequency pulsed electromagnetic fields selectively impair breast cancer cell viability.

    PubMed

    Crocetti, Sara; Beyer, Christian; Schade, Grit; Egli, Marcel; Fröhlich, Jürg; Franco-Obregón, Alfredo

    2013-01-01

    A common drawback of many anticancer therapies is non-specificity in action of killing. We investigated the potential of ultra-low intensity and frequency pulsed electromagnetic fields (PEMFs) to kill breast cancer cells. Our criteria to accept this technology as a potentially valid therapeutic approach were: 1) cytotoxicity to breast cancer cells and; 2) that the designed fields proved innocuous to healthy cell classes that would be exposed to the PEMFs during clinical treatment. MCF7 breast cancer cells and their normal counterparts, MCF10 cells, were exposed to PEMFs and cytotoxic indices measured in order to design PEMF paradigms that best kill breast cancer cells. The PEMF parameters tested were: 1) frequencies ranging from 20 to 50 Hz; 2) intensities ranging from 2 mT to 5 mT and; 3) exposure durations ranging from 30 to 90 minutes per day for up to three days to determine the optimum parameters for selective cancer cell killing. We observed a discrete window of vulnerability of MCF7 cells to PEMFs of 20 Hz frequency, 3 mT magnitude and exposure duration of 60 minutes per day. The cell damage accrued in response to PEMFs increased with time and gained significance after three days of consecutive daily exposure. By contrast, the PEMFs parameters determined to be most cytotoxic to breast cancer MCF-7 cells were not damaging to normal MCF-10 cells. Based on our data it appears that PEMF-based anticancer strategies may represent a new therapeutic approach to treat breast cancer without affecting normal tissues in a manner that is non-invasive and can be potentially combined with existing anti-cancer treatments.

  2. Low Intensity and Frequency Pulsed Electromagnetic Fields Selectively Impair Breast Cancer Cell Viability

    PubMed Central

    Crocetti, Sara; Beyer, Christian; Schade, Grit; Egli, Marcel; Fröhlich, Jürg; Franco-Obregón, Alfredo

    2013-01-01

    Introduction A common drawback of many anticancer therapies is non-specificity in action of killing. We investigated the potential of ultra-low intensity and frequency pulsed electromagnetic fields (PEMFs) to kill breast cancer cells. Our criteria to accept this technology as a potentially valid therapeutic approach were: 1) cytotoxicity to breast cancer cells and; 2) that the designed fields proved innocuous to healthy cell classes that would be exposed to the PEMFs during clinical treatment. Methods MCF7 breast cancer cells and their normal counterparts, MCF10 cells, were exposed to PEMFs and cytotoxic indices measured in order to design PEMF paradigms that best kill breast cancer cells. The PEMF parameters tested were: 1) frequencies ranging from 20 to 50 Hz; 2) intensities ranging from 2 mT to 5 mT and; 3) exposure durations ranging from 30 to 90 minutes per day for up to three days to determine the optimum parameters for selective cancer cell killing. Results We observed a discrete window of vulnerability of MCF7 cells to PEMFs of 20 Hz frequency, 3 mT magnitude and exposure duration of 60 minutes per day. The cell damage accrued in response to PEMFs increased with time and gained significance after three days of consecutive daily exposure. By contrast, the PEMFs parameters determined to be most cytotoxic to breast cancer MCF-7 cells were not damaging to normal MCF-10 cells. Conclusion Based on our data it appears that PEMF-based anticancer strategies may represent a new therapeutic approach to treat breast cancer without affecting normal tissues in a manner that is non-invasive and can be potentially combined with existing anti-cancer treatments. PMID:24039828

  3. Influence of the anisotropic mechanical properties of the skull in low-intensity focused ultrasound towards neuromodulation of the brain.

    PubMed

    Metwally, Mohamed K; Han, Hee-Sok; Jeon, Hyun Jae; Khang, Gon; Kim, Tae-Seong

    2013-01-01

    Lately, neuromodulation of the brain is considered one of the promising applications of ultrasound technology in which low-intensity focused ultrasound (LIFU) is used noninvasively to excite or inhibit neuronal activity. In LIFU, one of critical barriers in the propagation of ultrasound wave is the skull, which is known to be highly anisotropic mechanically: this affects the ultrasound focusing, thereby neuromodulation effects. This study aims to investigate the influence of the anisotropic properties of the skull on the LIFU via finite element head models incorporating the anisotropic properties of the skull. We have examined the pressure and stress distributions within the head in LIFU. Our results show that though most of the pressure that reaches to the brain is due to the longitudinal wave propagation through the skull, the normal stress in the transverse direction of the wave propagation has the main role to control the pressure profile inside the brain more than the shear stress. The results also show that the anisotropic properties of skull contribute in broadening the focal zone in comparison to that of the isotropic skull.

  4. Skin temperature increase mediated by wearable, long duration, low-intensity therapeutic ultrasound

    NASA Astrophysics Data System (ADS)

    Langer, Matthew D.; Huang, Wenyi; Ghanem, Angi; Guo, Yuan; Lewis, George K.

    2017-03-01

    One of the safety concerns with the delivery of therapeutic ultrasound is overheating of the transducer-skin interface due to poor or improper coupling. The objective of this research was to define a model that could be used to calculate the heating in the skin as a result of a novel, wearable long-duration ultrasound device. This model was used to determine that the maximum heating in the skin remained below the minimum threshold necessary to cause thermal injury over multiple hours of use. In addition to this model data, a human clinical study used wire thermocouples on the skin surface to measure heating characteristics during treatment with the sustained ultrasound system. Parametric analysis of the model determined that the maximum temperature increase is at the surface of the skin ranged from 40-41.8° C when perfusion was taken into account. The clinical data agreed well with the model predictions. The average steady state temperature observed across all 44 subjects was 40°C. The maximum temperature observed was less than 44° C, which is clinically safe for over 5 hours of human skin contact. The resultant clinical temperature data paired well with the model data suggesting the model can be used for future transducer and ultrasound system design simulation. As a result, the device was validated for thermal safety for typical users and use conditions.

  5. Ultrasound with low intensity assisted the synthesis of nanocrystalline TiO2 without calcination.

    PubMed

    Ghows, Narjes; Entezari, Mohamad H

    2010-06-01

    A novel method has been developed for the preparation of nano-sized TiO(2) with anatase phase. Nanoparticles with diameter about 6 nm were prepared at a relatively low temperature (75 degrees C) and short time. The synthesis was carried out by the hydrolysis of titanium tetra-isopropoxide (TTIP) in the presence of water, ethanol, and dispersant under ultrasonic irradiation (500 kHz) at low intensity. The results show that variables such as water/ethanol ratio, irradiation time, and temperature have a great influence on the particle size and crystalline phases of TiO(2) nanoparticles. Characterization of the product was carried out by different techniques such as powder X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and UV-vis spectroscopy.

  6. [Effect of low intensity pulse-modulated electromagnetic radiation on activity of alkaline phosphatase in blood serum].

    PubMed

    Pashovkina, M S; Akoev, I G

    2001-01-01

    The change in alkaline phosphotase activity in vitro with frequencies modulation at low intensity of pulse-modulated electromagnetic radiation was experimentally shown (EMR, 2375 MHz, intensity: 0.8, 8.0; 40.0 microW/cm2; range modulation: 30-310 Hz; time of interaction: 1-3 min). Revealed effects could be regarded as an evidence of informative character of interaction of modulated EMR.

  7. Low-Intensity Ultrasound Combined with Hematoporphyrin Monomethyl Ether in the Treatment of Experimental Periodontitis in Rats

    PubMed Central

    Zhuang, Deshu; Ji, Zongshan; Wang, Xiaochun; Zhou, Qi; Cao, Wenwu

    2016-01-01

    Objectives. This study aims to evaluate the efficacy of hematoporphyrin monomethyl ether- (HMME-) mediated sonodynamic therapy (SDT) on experimental periodontal disease in rats. Methods. Periodontal disease was induced by submerging ligatures at the first maxillary molar subgingival region in forty-eight male SD rats. After 30 days, the ligatures were removed. The rats were randomly allocated into four groups; the experimental SDT group was treated through hypodermic injection of 40 μg/mL HMME and 3 W/cm2 low-intensity ultrasound irradiation (1 MHz, 600 s). Those in control groups received 40 μg/mL HMME alone (control 1 group) or 3 W/cm2 ultrasound irradiation alone (control 2 group) or were subjected to neither HMME nor ultrasound (control 3 group). After 10 days of treatment, all rats were euthanized, the maxilla was obtained for histological examination, and the alveolar bone level was evaluated by histometric analysis. Results. The control groups showed more bone loss (P < 0.05) after 10 days of treatment than the SDT group. There is no significant difference among the control groups (P > 0.05). Conclusions. HMME mediated SDT was an effective therapy of experimental periodontal tissue in rats. PMID:27975058

  8. Low-intensity continuous ultrasound triggers effective bisphosphonate anticancer activity in breast cancer

    NASA Astrophysics Data System (ADS)

    Tardoski, Sophie; Ngo, Jacqueline; Gineyts, Evelyne; Roux, Jean-Paul; Clézardin, Philippe; Melodelima, David

    2015-11-01

    Ultrasound (US) is a non-ionizing pressure wave that can produce mechanical and thermal effects. Bisphosphonates have demonstrated clinical utility in bone metastases treatment. Preclinical studies suggest that bisphosphonates have anticancer activity. However, bisphosphonates exhibit a high affinity for bone mineral, which reduces their bioavailibity for tumor cells. Ultrasound has been shown to be effective for drug delivery but in interaction with gas bubbles or encapsulated drugs. We examined the effects of a clinically relevant dose of bisphosphonate zoledronate (ZOL) in combination with US. In a bone metastasis model, mice treated with ZOL+US had osteolytic lesions that were 58% smaller than those of ZOL-treated animals as well as a reduced skeletal tumor burden. In a model of primary tumors, ZOL+US treatment reduced by 42% the tumor volume, compared with ZOL-treated animals. Using a fluorescent bisphosphonate, we demonstrated that US forced the release of bisphosphonate from the bone surface, enabling a continuous impregnation of the bone marrow. Additionally, US forced the penetration of ZOL within tumors, as demonstrated by the intratumoral accumulation of unprenylated Rap1A, a surrogate marker of ZOL antitumor activity. Our findings made US a promising modality to trigger bisphosphonate anticancer activity in bone metastases and in primary tumors.

  9. Low-intensity continuous ultrasound triggers effective bisphosphonate anticancer activity in breast cancer

    PubMed Central

    Tardoski, Sophie; Ngo, Jacqueline; Gineyts, Evelyne; Roux, Jean-Paul; Clézardin, Philippe; Melodelima, David

    2015-01-01

    Ultrasound (US) is a non-ionizing pressure wave that can produce mechanical and thermal effects. Bisphosphonates have demonstrated clinical utility in bone metastases treatment. Preclinical studies suggest that bisphosphonates have anticancer activity. However, bisphosphonates exhibit a high affinity for bone mineral, which reduces their bioavailibity for tumor cells. Ultrasound has been shown to be effective for drug delivery but in interaction with gas bubbles or encapsulated drugs. We examined the effects of a clinically relevant dose of bisphosphonate zoledronate (ZOL) in combination with US. In a bone metastasis model, mice treated with ZOL+US had osteolytic lesions that were 58% smaller than those of ZOL-treated animals as well as a reduced skeletal tumor burden. In a model of primary tumors, ZOL+US treatment reduced by 42% the tumor volume, compared with ZOL-treated animals. Using a fluorescent bisphosphonate, we demonstrated that US forced the release of bisphosphonate from the bone surface, enabling a continuous impregnation of the bone marrow. Additionally, US forced the penetration of ZOL within tumors, as demonstrated by the intratumoral accumulation of unprenylated Rap1A, a surrogate marker of ZOL antitumor activity. Our findings made US a promising modality to trigger bisphosphonate anticancer activity in bone metastases and in primary tumors. PMID:26578234

  10. Low-intensity continuous ultrasound triggers effective bisphosphonate anticancer activity in breast cancer.

    PubMed

    Tardoski, Sophie; Ngo, Jacqueline; Gineyts, Evelyne; Roux, Jean-Paul; Clézardin, Philippe; Melodelima, David

    2015-11-18

    Ultrasound (US) is a non-ionizing pressure wave that can produce mechanical and thermal effects. Bisphosphonates have demonstrated clinical utility in bone metastases treatment. Preclinical studies suggest that bisphosphonates have anticancer activity. However, bisphosphonates exhibit a high affinity for bone mineral, which reduces their bioavailability for tumor cells. Ultrasound has been shown to be effective for drug delivery but in interaction with gas bubbles or encapsulated drugs. We examined the effects of a clinically relevant dose of bisphosphonate zoledronate (ZOL) in combination with US. In a bone metastasis model, mice treated with ZOL+US had osteolytic lesions that were 58% smaller than those of ZOL-treated animals as well as a reduced skeletal tumor burden. In a model of primary tumors, ZOL+US treatment reduced by 42% the tumor volume, compared with ZOL-treated animals. Using a fluorescent bisphosphonate, we demonstrated that US forced the release of bisphosphonate from the bone surface, enabling a continuous impregnation of the bone marrow. Additionally, US forced the penetration of ZOL within tumors, as demonstrated by the intratumoral accumulation of unprenylated Rap1A, a surrogate marker of ZOL antitumor activity. Our findings made US a promising modality to trigger bisphosphonate anticancer activity in bone metastases and in primary tumors.

  11. Low intensity focused ultrasound (LOFU) modulates unfolded protein response and sensitizes prostate cancer to 17AAG

    PubMed Central

    Saha, Subhrajit; Bhanja, Payel; Partanen, Ari; Zhang, Wei; Liu, Laibin; Tomé, Wolfgang; Guha, Chandan

    2014-01-01

    The hypoxic tumor microenvironment generates oxidative Endoplasmic Reticulum (ER) stress, resulting in protein misfolding and unfolded protein response (UPR). UPR induces several molecular chaperones including heat-shock protein 90 (HSP90), which corrects protein misfolding and improves survival of cancer cells and resistance to tumoricidal therapy although prolonged activation of UPR induces cell death. The HSP90 inhibitor, 17AAG, has shown promise against various solid tumors, including prostate cancer (PC). However, therapeutic doses of 17AAG elicit systemic toxicity. In this manuscript, we describe a new paradigm where the combination therapy of a non-ablative and non-invasive low energy focused ultrasound (LOFU) and a non-toxic, low dose 17AAG causes synthetic lethality and significant tumoricidal effects in mouse and human PC xenografts. LOFU induces ER stress and UPR in tumor cells without inducing cell death. Treatment with a non-toxic dose of 17AAG further increased ER stress in LOFU treated PC and switch UPR from a cytoprotective to an apoptotic response in tumors resulting significant induction of apoptosis and tumor growth retardation. These observations suggest that LOFU-induced ER stress makes the ultrasound-treated tumors more susceptible to chemotherapeutic agents, such as 17AAG. Thus, a novel therapy of LOFU-induced chemosensitization may be designed for locally advanced and recurrent tumors. PMID:25594042

  12. [The effect of low-intensity pulsed sound waves delivered by the Exogen device on Staphylococcus aureus morphology and genetics].

    PubMed

    Ayan, Irfan; Aslan, Gönül; Cömelekoğlu, Ulkü; Yilmaz, Nejat; Colak, Mehmet

    2008-01-01

    We investigated the effect of low-intensity pulsed sound waves delivered by the Exogen device, which is recommended for the treatment of delayed union and nonunion in orthopedic surgery, on the colony number, antimicrobial susceptibility, bacterial morphology, and genetics of Staphylococcus aureus, which is a frequent pathogen in orthopedic infections. Thirty tubes containing 0.5 McFarland suspensions of S. aureus (ATCC 25923) were used. Fifteen tubes forming the test group were subjected to low-intensity sound waves by the Exogen device for 20 minutes. The remaining 15 tubes were untreated as controls. The two groups were then compared with respect to colony number, antibiotic susceptibility, and genotypic properties. The tubes were examined histologically by electron microscopy. The test tubes treated with sound waves showed a significantly lower number of bacteria colonies compared to the control tubes (p<0.001). The two groups were similar with respect to antibiotic susceptibility and genotypic properties. Bacterial cell wall structure in the control group was of normal appearance, whereas partial destruction and break-up were observed in test samples. Bacterial cell wall thickness was significantly higher in the test group compared to the control group (41.54 nm and 24.27 nm, respectively; p<0.001). Low-intensity sound waves may be beneficial as a prophylactic measure to prevent infections in primary orthopedic operations and as an adjuvant therapy for infected nonunions.

  13. Effect of low-intensity focused ultrasound on endothelin-1, nitrogen monoxide and oxytocin receptor in the uterine tissues of Sprague-Dawley rats following abortion

    PubMed Central

    ZHANG, YANXIA; GUO, JUFANG; LIN, CHUAN; LU, LU; LI, CHENGZHI

    2016-01-01

    The aim of the present study was to investigate the effect of low-intensity focused ultrasound on endothelin-1 (ET-1), nitrogen monoxide (NO) and oxytocin receptor (OXTR) levels in the uterine tissues of Sprague-Dawley (SD) rats following abortion. A total of 30 SD rats undergoing complete abortion were randomly divided into ultrasound irradiation and sham irradiation groups (15 rats per group). The rats in the ultrasound irradiation group were treated with low-intensity ultrasound (sound intensity, 2 W/cm2; frequency, 0.8 MHz) for 30 min daily for 5 consecutive days, and those in the sham irradiation group received sham treatment. The uterine tissue was removed to measure the levels of ET-1, NO and OXTR using the enzyme-linked immunosorbent assay and immunohistochemistry, respectively. The ET-1 level in the uterine tissues was significantly higher in the ultrasound irradiation group compared to the sham irradiation group (P<0.05); however, the NO level was similar in the 2 groups (P>0.05). In the uterine myometrium and endometrium, the strong positive expression of OXTR was observed in the ultrasound irradiation group, which was significantly higher compared to the sham irradiation group (P<0.05). Low-intensity ultrasound could promote uterine involution by increasing ET-1 levels, modifying the balance of ET-1 and NO, and enhancing the expression of OXTR in the uterine myometrium and endometrium. PMID:26998272

  14. Effect of low-intensity focused ultrasound on endothelin-1, nitrogen monoxide and oxytocin receptor in the uterine tissues of Sprague-Dawley rats following abortion.

    PubMed

    Zhang, Yanxia; Guo, Jufang; Lin, Chuan; Lu, L U; Li, Chengzhi

    2016-03-01

    The aim of the present study was to investigate the effect of low-intensity focused ultrasound on endothelin-1 (ET-1), nitrogen monoxide (NO) and oxytocin receptor (OXTR) levels in the uterine tissues of Sprague-Dawley (SD) rats following abortion. A total of 30 SD rats undergoing complete abortion were randomly divided into ultrasound irradiation and sham irradiation groups (15 rats per group). The rats in the ultrasound irradiation group were treated with low-intensity ultrasound (sound intensity, 2 W/cm(2); frequency, 0.8 MHz) for 30 min daily for 5 consecutive days, and those in the sham irradiation group received sham treatment. The uterine tissue was removed to measure the levels of ET-1, NO and OXTR using the enzyme-linked immunosorbent assay and immunohistochemistry, respectively. The ET-1 level in the uterine tissues was significantly higher in the ultrasound irradiation group compared to the sham irradiation group (P<0.05); however, the NO level was similar in the 2 groups (P>0.05). In the uterine myometrium and endometrium, the strong positive expression of OXTR was observed in the ultrasound irradiation group, which was significantly higher compared to the sham irradiation group (P<0.05). Low-intensity ultrasound could promote uterine involution by increasing ET-1 levels, modifying the balance of ET-1 and NO, and enhancing the expression of OXTR in the uterine myometrium and endometrium.

  15. Modification of semiconductor materials with the use of plasma produced by low intensity repetitive laser pulses

    NASA Astrophysics Data System (ADS)

    Wolowski, J.; Rosiński, M.; Badziak, J.; Czarnecka, A.; Parys, P.; Turan, R.; Yerci, S.

    2008-03-01

    This work reports experiments concerning specific application of laser-produced plasma at IPPLM in Warsaw. A repetitive pulse laser system of parameters: energy up to 0.8 J in a 3.5 ns-pulse, wavelength of 1.06 μm, repetition rate of up to 10 Hz, has been employed in these investigations. The characterisation of laser-produced plasma was performed with the use of "time-of-flight" ion diagnostics simultaneously with other diagnostic methods. The results of laser-matter interaction were obtained in dependence on laser pulse parameters, illumination geometry and target material. The modified SiO2 layers and sample surface properties were characterised with the use of different methods at the Middle-East Technological University in Ankara and at the Warsaw University of technology. The production of the Ge nanocrystallites has been demonstrated for annealed samples prepared in different experimental conditions.

  16. Effects of low-intensity pulsed electromagnetic fields on the early development of sea urchins

    SciTech Connect

    Falugi, C.; Grattarola, M.; Prestipino, G.

    1987-06-01

    The effects of weak electromagnetic signals on the early development of the sea urchin Paracentrotus lividus have been studied. The duration and repetition of the pulses were similar to those used for bone healing in clinical practice. A sequence of pulses, applied for a time ranging from 2 to 4 h, accelerates the cleavages of sea urchin embryo cells. This effect can be quantitatively assessed by determining the time shifts induced by the applied electromagnetic field on the completion of the first and second cleavages in a population of fertilized eggs. The exposed embryos were allowed to develop up to the pluteus stage, showing no abnormalities.

  17. Effects of low-intensity pulsed electromagnetic fields on the early development of sea urchins.

    PubMed Central

    Falugi, C; Grattarola, M; Prestipino, G

    1987-01-01

    The effects of weak electromagnetic signals on the early development of the sea urchin Paracentrotus lividus have been studied. The duration and repetition of the pulses were similar to those used for bone healing in clinical practice. A sequence of pulses, applied for a time ranging from 2 to 4 h, accelerates the cleavages of sea urchin embryo cells. This effect can be quantitatively assessed by determining the time shifts induced by the applied electromagnetic field on the completion of the first and second cleavages in a population of fertilized eggs. The exposed embryos were allowed to develop up to the pluteus stage, showing no abnormalities. Images FIGURE 3 FIGURE 4 PMID:3607217

  18. Mechanism of rat osteosarcoma cell apoptosis induced by a combination of low-intensity ultrasound and 5-aminolevulinic acid in vitro.

    PubMed

    Li, Y N; Zhou, Q; Yang, B; Hu, Z; Wang, J H; Li, Q S; Cao, W W

    2015-08-14

    We investigated the killing effect of low-intensity ultrasound combined with 5-aminolevulinic acid (5-ALA) on the rat osteosarcoma cell line UMR-106. Logarithmic-phase UMR-106 cells were divided into a control group, ultrasound group and 5-ALA group. The cell apoptotic rate, production of reactive oxygen species, and the change in mitochondrial membrane potential were analyzed by flow cytometry; ultrastructural changes were observed by transmission electron microscopy. Using low-intensity ultrasound at 1.0 MHz and 2.0 W/cm(2) plus 5-ALA at a concentration of 2 mM, the apoptotic rate of the sonodynamic therapy group was 27.2 ± 3.4% which was significantly higher than that of the control group, ultrasound group, and 5-ALA group (P < 0.05). The production of reactive oxygen species was 32.6 ± 2.2% and the decrease in mitochondrial membrane potential was 39.5 ± 2.5%. The 33342 staining showed nuclear condensation and fragmentation in the ultrasound group and 5-ALA group. Structural changes in the cell membrane, mitochondria, Golgi apparatus, and other organelles observed by transmission electron microscopy included formation of apoptotic bodies. The killing effect of low-intensity ultrasound combined with 5-ALA on UMR-106 cells was significant. Cell apoptosis played a vital role in the killing effect, and the mitochondria pathway contributed to the apoptosis of UMR-106 cells.

  19. Applications of ions produced by low intensity repetitive laser pulses for implantation into semiconductor materials

    NASA Astrophysics Data System (ADS)

    Wołowski, J.; Badziak, J.; Czarnecka, A.; Parys, P.; Pisarek, M.; Rosinski, M.; Turan, R.; Yerci, S.

    This work reports experiment concerning specific applications of implantation of laser-produced ions for production of semiconductor nanocrystals. The investigation was carried out in the IPPLM within the EC STREP `SEMINANO' project. A repetitive pulse laser system of parameters: energy up to 0.8 J in a 3.5 ns-pulse, wavelength of 1.06 μ m, repetition rate of up to 10 Hz, has been employed in these investigations. The characterisation of laser-produced ions was performed with the use of `time-of-flight' ion diagnostics simultaneously with other diagnostic methods in dependence on laser pulse parameters, illumination geometry and target material. The properties of laser-implanted and modified SiO2 layers on sample surface were characterised with the use of different methods (XPS + ASD, Raman spectroscopy, PL spectroscopy) at the Middle East Technological University in Ankara and at the Warsaw University of Technology. The production of the Ge nanocrystallites has been demonstrated for annealed samples prepared in different experimental conditions.

  20. Efficacy of pulsed low-intensity electric neuromuscular stimulation in reducing pain and disability in patients with myofascial syndrome.

    PubMed

    Iodice, P; Lessiani, G; Franzone, G; Pezzulo, G

    2016-01-01

    Myofascial pain syndrome (MPS) is characterized by chronic pain in multiple myofascial trigger points and fascial constrictions. In recent years, the scientific literature has recognized the need to include the patient with MPS in a multidimensional rehabilitation project. At the moment, the most widely recognized therapeutic methods for the treatment of myofascial syndrome include the stretch and spray pressure massage. Microcurrent electric neuromuscular stimulation was proposed in pain management for its effects on normalizing bioelectricity of cells and for its sub-sensory application. In this study, we tested the efficacy of low-intensity pulsed electric neuromuscular stimulus (PENS) on pain in patients with MPS of cervical spine muscles. We carried out a prospective-analytic longitudinal study at an outpatient clinic during two weeks. Forty subjects (mean age 42±13 years) were divided into two groups: treatment (TrGr, n=20) and control group (CtrlGr, n=20). Visual-analog scale (VAS) values, concerning the spontaneous and movement-related pain in the cervical-dorsal region at baseline (T0) and at the end of the study (T1), showed a reduction from 7 to 3.81 (p < 0.001) in TrGr. In the CtrlGr, VAS was reduced from 8.2 to 7.2 (n.s.). Moreover, the pressure pain threshold at T0 was 2.1 vs 4.2 at T1 (p < 0.001) in TrG. In the CtrlGR we observed no significant changes. Modulated low-intensity PENS is an innovative therapy permitting to act on the transmission of pain and on the restoration of tissue homeostasis. It seems to affect the transmission of pain through the stimulation of A-beta fibers. The above results show that low-intensity PENS can be considered as an effective treatment to reduce pain and disability in patients with MPS.

  1. Characteristics of the pulsed ultrasound field.

    PubMed Central

    Wien, K. D.; Harder, D.

    1982-01-01

    Pulsed ultrasound fields show some quantitative differences from continuous fields. In order to support the analysis of bioeffects of pulsed ultrasound fields these differences are characterized. For each observation point, the sound pulse is calculated by wavelet addition. The total pulse length has a maximum near the transducer surface, corresponding to large differences in acoustical pathlength from the surface elements. Accordingly, the spectrum varies strongly in the near field. In the far field, pulse-length and spectrum are almost constant as long as frequency-dependent absorption is negligible. The radiation field at each point is described by the time integral of sound intensity over one pulse (energy transport per unit area) and by the corresponding "dose" (absorbed energy per unit volume in one pulse). Differences between the spatial distributions of these two quantities are mainly detectable in the near field, which is also the region where differences between continuous and pulsed ultrasound (at the same centre frequency) are considerable. PMID:6950776

  2. High-intensity attosecond X-ray source generation by using low-intensity spatial inhomogeneous mid-infrared pulse combined with an ultraviolet pulse

    NASA Astrophysics Data System (ADS)

    Feng, Liqiang; Liu, Hang

    2017-01-01

    We theoretically investigate the high-order harmonic spectra and the attosecond pulse generation from He+ ion driven by the spatial inhomogeneous combined field, consisting of a two-color low-intensity mid-infrared pulse (1013 W/cm2) and an ultraviolet (UV) pulse (1012 W/cm2). The numerical results show that due to the spatial inhomogeneous effect, the harmonic cutoffs are remarkably extended, and a 986 eV super-continuum can be obtained. Further with the proper introduction of an UV pulse (from 60 nm to 20 nm) to the two-color field, the harmonic yields are enhanced, especially for adding the 30 nm pulse case, a 1113 eV super-continuum (corresponding to a 34.1 dB enhanced field) with less harmonic modulation and six orders of magnitude enhancement can be obtained. Similar calculations have been performed for He atom and an 896 eV super-continuum with four orders of magnitude enhancement can be produced. Time-frequency harmonic distribution and time-dependent electron populations show that the single short quantum path contribution is responsible for the less harmonic modulation and the laser-induced electron excitation is responsible for the harmonic enhancement. Finally, by properly superposing the harmonics, a series of sub-50-as pulses including the whole X-ray region with 3-6 orders of magnitude enhancement can be obtained.

  3. Yeast cell inactivation related to local heating induced by low-intensity electric fields with long-duration pulses.

    PubMed

    Guyot, Stéphane; Ferret, Eric; Boehm, Jean-Baptiste; Gervais, Patrick

    2007-01-25

    The effects of electric field (EF) treatments on Saccharomyces cerevisiae viability were investigated using a PG200 electroporator (Hoefer Scientific Instrument, San Fransisco, CA, USA) with specific attention to induced thermal effects on cell death. Lethal electric fields (1.5 kV cm(-1) for 5 s) were shown to cause heat variations in the cell suspension medium (water+glycerol), while corresponding classical thermal treatments at equivalent temperatures had no effect on the cells viability. Variations of the electrical conductivity of the intra- and extracellular matrix caused by ions and solutes transfer across the membrane were shown to be involved in the observed heating. The results permitted to build a theoretical model for the temperature variations induced by electric fields. Using this model and the electrical conductivity of the different media, a plausible explanation of the cell death induced by low-intensity electric fields with long-duration pulses has been proposed. Indeed, cell mortality could in part be caused by direct and indirect effects of electric fields. Direct effects are related to well known electromechanical phenomena, whereas indirect effects are related to secondary thermal stress caused by plasma membrane thermoporation. This thermoporation was attributed to electrical conductivity variations and the corresponding intracellular heating.

  4. Low-intensity focused ultrasound (LIFU)-induced acoustic droplet vaporization in phase-transition perfluoropentane nanodroplets modified by folate for ultrasound molecular imaging.

    PubMed

    Liu, Jianxin; Shang, Tingting; Wang, Fengjuan; Cao, Yang; Hao, Lan; Ren, JianLi; Ran, Haitao; Wang, Zhigang; Li, Pan; Du, Zhiyu

    2017-01-01

    The commonly used ultrasound (US) molecular probes, such as targeted microbubbles and perfluorocarbon emulsions, present a number of inherent problems including the conflict between US visualization and particle penetration. This study describes the successful fabrication of phase changeable folate-targeted perfluoropentane nanodroplets (termed FA-NDs), a novel US molecular probe for tumor molecular imaging with US. Notably, these FA-NDs can be triggered by low-intensity focused US (LIFU) sonication, providing excellent US enhancement in B-mode and contrast-enhanced US mode in vitro. After intravenous administration into nude mice bearing SKOV3 ovarian carcinomas, 1,1'-dioctadecyl-3,3,3',3' -tetramethylindotricarbocya-nine iodide-labeled FA-NDs were found to accumulate in the tumor region. FA-NDs injection followed by LIFU sonication exhibited remarkable US contrast enhancement in the tumor region. In conclusion, combining our elaborately developed FA-NDs with LIFU sonication provides a potential protocol for US molecular imaging in folate receptor-overexpressing tumors.

  5. Low-intensity focused ultrasound (LIFU)-induced acoustic droplet vaporization in phase-transition perfluoropentane nanodroplets modified by folate for ultrasound molecular imaging

    PubMed Central

    Liu, Jianxin; Shang, Tingting; Wang, Fengjuan; Cao, Yang; Hao, Lan; Ren, JianLi; Ran, Haitao; Wang, Zhigang; Li, Pan; Du, Zhiyu

    2017-01-01

    The commonly used ultrasound (US) molecular probes, such as targeted microbubbles and perfluorocarbon emulsions, present a number of inherent problems including the conflict between US visualization and particle penetration. This study describes the successful fabrication of phase changeable folate-targeted perfluoropentane nanodroplets (termed FA-NDs), a novel US molecular probe for tumor molecular imaging with US. Notably, these FA-NDs can be triggered by low-intensity focused US (LIFU) sonication, providing excellent US enhancement in B-mode and contrast-enhanced US mode in vitro. After intravenous administration into nude mice bearing SKOV3 ovarian carcinomas, 1,1′-dioctadecyl-3,3,3′,3′ -tetramethylindotricarbocya-nine iodide-labeled FA-NDs were found to accumulate in the tumor region. FA-NDs injection followed by LIFU sonication exhibited remarkable US contrast enhancement in the tumor region. In conclusion, combining our elaborately developed FA-NDs with LIFU sonication provides a potential protocol for US molecular imaging in folate receptor-overexpressing tumors. PMID:28184161

  6. CO2 bubbling-based 'Nanobomb' System for Targetedly Suppressing Panc-1 Pancreatic Tumor via Low Intensity Ultrasound-activated Inertial Cavitation

    PubMed Central

    Zhang, Kun; Xu, Huixiong; Chen, Hangrong; Jia, Xiaoqing; Zheng, Shuguang; Cai, Xiaojun; Wang, Ronghui; Mou, Juan; Zheng, Yuanyi; Shi, Jianlin

    2015-01-01

    Noninvasive and targeted physical treatment is still desirable especially for those cancerous patients. Herein, we develop a new physical treatment protocol by employing CO2 bubbling-based 'nanobomb' system consisting of low-intensity ultrasound (1.0 W/cm2) and a well-constructed pH/temperature dual-responsive CO2 release system. Depending on the temperature elevation caused by exogenous low-intensity therapeutic ultrasound irradiation and the low pH caused by the endogenous acidic-environment around/within tumor, dual-responsive CO2 release system can quickly release CO2 bubbles, and afterwards, the generated CO2 bubbles waves will timely explode before dissolution due to triggering by therapeutic ultrasound waves. Related bio-effects (e.g., cavitation, mechanical, shock waves, etc) caused by CO2 bubbles' explosion effectively induce instant necrosis of panc-1 cells and blood vessel destruction within panc-1 tumor, and consequently inhibit the growth of panc-1 solid tumor, simultaneously minimizing the side effects to normal organs. This new physiotherapy employing CO2 bubbling-based 'nanobomb' system promises significant potentials in targetedly suppressing tumors, especially for those highly deadly cancers. PMID:26379793

  7. CO2 bubbling-based 'Nanobomb' System for Targetedly Suppressing Panc-1 Pancreatic Tumor via Low Intensity Ultrasound-activated Inertial Cavitation.

    PubMed

    Zhang, Kun; Xu, Huixiong; Chen, Hangrong; Jia, Xiaoqing; Zheng, Shuguang; Cai, Xiaojun; Wang, Ronghui; Mou, Juan; Zheng, Yuanyi; Shi, Jianlin

    2015-01-01

    Noninvasive and targeted physical treatment is still desirable especially for those cancerous patients. Herein, we develop a new physical treatment protocol by employing CO2 bubbling-based 'nanobomb' system consisting of low-intensity ultrasound (1.0 W/cm(2)) and a well-constructed pH/temperature dual-responsive CO2 release system. Depending on the temperature elevation caused by exogenous low-intensity therapeutic ultrasound irradiation and the low pH caused by the endogenous acidic-environment around/within tumor, dual-responsive CO2 release system can quickly release CO2 bubbles, and afterwards, the generated CO2 bubbles waves will timely explode before dissolution due to triggering by therapeutic ultrasound waves. Related bio-effects (e.g., cavitation, mechanical, shock waves, etc) caused by CO2 bubbles' explosion effectively induce instant necrosis of panc-1 cells and blood vessel destruction within panc-1 tumor, and consequently inhibit the growth of panc-1 solid tumor, simultaneously minimizing the side effects to normal organs. This new physiotherapy employing CO2 bubbling-based 'nanobomb' system promises significant potentials in targetedly suppressing tumors, especially for those highly deadly cancers.

  8. Circumvention of cisplatin resistance in ovarian cancer by combination of cyclosporin A and low-intensity ultrasound.

    PubMed

    Yu, Tinghe; Yang, Yan; Zhang, Jiao; He, Haining; Ren, Xueyi

    2015-04-01

    Cisplatin resistance is a challenge in the treatment of ovarian cancer. The aim of this study was to explore if ultrasound can overcome chemoresistance and enhance chemosensitization due to cyclosporin A. Ultrasound and/or cyclosporin A were employed to overcome cisplatin resistance in human ovarian cancer cell line COC1/DDP. Mechanisms were explored from the perspective of: DNA damage, intracellular platinum level, detoxification, and genes related to drug efflux and DNA repair. In vivo therapeutic efficacy was validated in a short-term model (subrenal cell-clot transplantation) in mice and the survival benefit was investigated in an orthotopic cancer model in mice using HO-8910PM cells. The findings were: (i) ultrasound enhanced the effect of cisplatin leading to a lower cell-survival rate (IC50 decreased from 3.19 to 0.35 μg/ml); (ii) ultrasound enhanced cisplatin via direct (increasing the intercellular level of active platinum) and indirect (decreasing the glutathione level, and expression of LRP and ERCC1 genes) mechanisms that intensified cisplatin-induced DNA damage, thus enhancing cell apoptosis and necrosis; (iii) cisplatin followed by ultrasound led to small tumor sizes in the short-term model without exacerbation of the systemic toxicity, and prolonged the survival times in the orthotopic model; and (iv) ultrasound synergized the sensitization due to cyclosporin A in vitro and in vivo. These data demonstrated that ultrasound combined with cyclosporin A overcame cisplatin resistance in ovarian cancer. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Pulse Compression Techniques for Laser Generated Ultrasound

    NASA Technical Reports Server (NTRS)

    Anastasi, R. F.; Madaras, E. I.

    1999-01-01

    Laser generated ultrasound for nondestructive evaluation has an optical power density limit due to rapid high heating that causes material damage. This damage threshold limits the generated ultrasound amplitude, which impacts nondestructive evaluation inspection capability. To increase ultrasound signal levels and improve the ultrasound signal-to-noise ratio without exceeding laser power limitations, it is possible to use pulse compression techniques. The approach illustrated here uses a 150mW laser-diode modulated with a pseudo-random sequence and signal correlation. Results demonstrate the successful generation of ultrasonic bulk waves in aluminum and graphite-epoxy composite materials using a modulated low-power laser diode and illustrate ultrasound bandwidth control.

  10. Pulsed ultrasound expands the extracellular and perivascular spaces of the brain

    PubMed Central

    Hersh, David S.; Nguyen, Ben A.; Dancy, Jimena G.; Adapa, Arjun R.; Winkles, Jeffrey A.; Woodworth, Graeme F.; Kim, Anthony J.; Frenkel, Victor

    2017-01-01

    Diffusion within the extracellular and perivascular spaces of the brain plays an important role in biological processes, therapeutic delivery, and clearance mechanisms within the central nervous system. Recently, ultrasound has been used to enhance the dispersion of locally administered molecules and particles within the brain, but ultrasound-mediated effects on the brain parenchyma remain poorly understood. We combined an electron microscopy-based ultrastructural analysis with high-resolution tracking of non-adhesive nanoparticles in order to probe changes in the extracellular and perivascular spaces of the brain following a non-destructive pulsed ultrasound regimen known to alter diffusivity in other tissues. Freshly obtained rat brain neocortical slices underwent sham treatment or pulsed, low intensity ultrasound for 5 minutes at 1 MHz. Transmission electron microscopy revealed intact cells and blood vessels and evidence of enlarged spaces, particularly adjacent to blood vessels, in ultrasound-treated brain slices. Additionally, ultrasound significantly increased the diffusion rate of 100 nm, 200 nm, and 500 nm nanoparticles that were injected into the brain slices, while 2000 nm particles were unaffected. In ultrasound-treated slices, 91.6% of the 100 nm particles, 20.7% of the 200 nm particles, 13.8% of the 500 nm particles, and 0% of the 2000 nm particles exhibited diffusive motion. Thus, pulsed ultrasound can have meaningful structural effects on the brain extracellular and perivascular spaces without evidence of tissue disruption.Keywords: Ultrasound, Extracellular space, Nanoparticle, Diffusion PMID:27369449

  11. Estimation of the distribution of low-intensity ultrasound mechanical index as a parameter affecting the proliferation of spermatogonia stem cells in vitro.

    PubMed

    Moghaddam, Zeinab Hormozi; Mokhtari-Dizaji, Manijhe; Movahedin, Mansoureh; Ravari, Mohammad Ehsan

    2017-07-01

    Considering the use of physical and mechanical stimulation, such as low-intensity ultrasound for proliferation and differentiation of stem cells, it is essential to understand the physical and acoustical mechanisms of acoustic waves in vitro. Mechanical index is used for quantifying acoustic cavitation and the relationship between acoustic pressure and the frequency. In this study, modeling of the mechanical index was applied to provide treatment protocol and to understand the effective physical processes on reproducibility of stem cells. Due to low intensity of ultrasound, Rayleigh integral model has been used for acoustic pressure computation. The acoustic pressure and mechanical index equations are modeled and solved to estimate optimal mechanical index for 28, 40, 150kHz and 1MHz frequencies. This model are solved in different intensities and distances from transducer in cylindrical coordinates. Based on the results of the mechanical index, regions with threshold mechanical index of 0.7 were identified for extracting of radiation arrangement to cell medium. Acoustic pressure distribution along the axial and radial was extracted. In order to validate the results of the modeling, the acoustic pressure in the water and near field depth was measured by a piston hydrophone. Results of modeling and experiments show that the model is consistent well to experimental results with 0.91 and 0.90 correlation of coefficient (p<0.05) for 1MHz and 40kHz. Low-intensity ultrasound with 0.40 mechanical index is more effective on enhancing the proliferation rate of the spermatogonia stem cells during the seven days of culture. In contrast, higher mechanical index has a harmful effect on the spermatogonial stem cells. Thus, considering cavitation threshold of different materials is necessary to find effective mechanical index ranges on proliferation for the used frequencies. This acoustic propagation model and ultrasound mechanical index assessments can be used with acceptable

  12. Controlling the acoustic streaming by pulsed ultrasounds.

    PubMed

    Hoyos, Mauricio; Castro, Angélica

    2013-01-01

    We propose a technique based on pulsed ultrasounds for controlling, reducing to a minimum observable value the acoustic streaming in closed ultrasonic standing wave fluidic resonators. By modifying the number of pulses and the repetition time it is possible to reduce the velocity of the acoustic streaming with respect to the velocity generated by the continuous ultrasound mode of operation. The acoustic streaming is observed at the nodal plane where a suspension of 800nm latex particles was focused by primary radiation force. A mixture of 800nm and 15μm latex particles has been also used for showing that the acoustic streaming is hardly reduced while primary and secondary forces continue to operate. The parameter we call "pulse mode factor" i.e. the time of applied ultrasound divided by the duty cycle, is found to be the adequate parameter that controls the acoustic streaming. We demonstrate that pulsed ultrasound is more efficient for controlling the acoustic streaming than the variation of the amplitude of the standing waves.

  13. Pulsed ultrasound expands the extracellular and perivascular spaces of the brain.

    PubMed

    Hersh, David S; Nguyen, Ben A; Dancy, Jimena G; Adapa, Arjun R; Winkles, Jeffrey A; Woodworth, Graeme F; Kim, Anthony J; Frenkel, Victor

    2016-09-01

    Diffusion within the extracellular and perivascular spaces of the brain plays an important role in biological processes, therapeutic delivery, and clearance mechanisms within the central nervous system. Recently, ultrasound has been used to enhance the dispersion of locally administered molecules and particles within the brain, but ultrasound-mediated effects on the brain parenchyma remain poorly understood. We combined an electron microscopy-based ultrastructural analysis with high-resolution tracking of non-adhesive nanoparticles in order to probe changes in the extracellular and perivascular spaces of the brain following a non-destructive pulsed ultrasound regimen known to alter diffusivity in other tissues. Freshly obtained rat brain neocortical slices underwent sham treatment or pulsed, low intensity ultrasound for 5min at 1MHz. Transmission electron microscopy revealed intact cells and blood vessels and evidence of enlarged spaces, particularly adjacent to blood vessels, in ultrasound-treated brain slices. Additionally, ultrasound significantly increased the diffusion rate of 100nm, 200nm, and 500nm nanoparticles that were injected into the brain slices, while 2000nm particles were unaffected. In ultrasound-treated slices, 91.6% of the 100nm particles, 20.7% of the 200nm particles, 13.8% of the 500nm particles, and 0% of the 2000nm particles exhibited diffusive motion. Thus, pulsed ultrasound can have meaningful structural effects on the brain extracellular and perivascular spaces without evidence of tissue disruption.

  14. The effect of noncontact, low-intensity, low-frequency therapeutic ultrasound on lower-extremity chronic wound pain: a retrospective chart review.

    PubMed

    Gehling, Marie L; Samies, John H

    2007-03-01

    Pain associated with chronic wounds and related wound care modalities presents a persistent clinical challenge in patient care, yet evidence supporting the effects of interventions on wound pain remains sparse. In response to initial clinical observations that several patients with painful chronic lower-extremity wounds reported a reduction in wound pain shortly after ultrasound therapy was initiated, a retrospective chart review and analysis of reported pain scores was conducted. The records of 15 consecutive patients (eight women, seven men, age range 28 to 88 years) with painful, nonhealing, lower-extremity wounds treated for 2 to 4 weeks with noncontact, low-intensity, low-frequency therapeutic ultrasound were reviewed and recorded pain scores abstracted. Mean pain scores decreased from 8.07 (+/- 1.91) pre-treatment to 1.67 (+/- 1.76) post-treatment (P = 0.0003). No patients reported worsening pain after treatment commenced. This preliminary evidence suggests that prospective, controlled clinical studies to evaluate the effect of this treatment on wound-related pain are warranted.

  15. Optimization of low-frequency low-intensity ultrasound-mediated microvessel disruption on prostate cancer xenografts in nude mice using an orthogonal experimental design

    PubMed Central

    YANG, YU; BAI, WENKUN; CHEN, YINI; LIN, YANDUAN; HU, BING

    2015-01-01

    The present study aimed to provide a complete exploration of the effect of sound intensity, frequency, duty cycle, microbubble volume and irradiation time on low-frequency low-intensity ultrasound (US)-mediated microvessel disruption, and to identify an optimal combination of the five factors that maximize the blockage effect. An orthogonal experimental design approach was used. Enhanced US imaging and acoustic quantification were performed to assess tumor blood perfusion. In the confirmatory test, in addition to acoustic quantification, the specimens of the tumor were stained with hematoxylin and eosin and observed using light microscopy. The results revealed that sound intensity, frequency, duty cycle, microbubble volume and irradiation time had a significant effect on the average peak intensity (API). The extent of the impact of the variables on the API was in the following order: Sound intensity; frequency; duty cycle; microbubble volume; and irradiation time. The optimum conditions were found to be as follows: Sound intensity, 1.00 W/cm2; frequency, 20 Hz; duty cycle, 40%; microbubble volume, 0.20 ml; and irradiation time, 3 min. In the confirmatory test, the API was 19.97±2.66 immediately subsequent to treatment, and histological examination revealed signs of tumor blood vessel injury in the optimum parameter combination group. In conclusion, the Taguchi L18 (3)6 orthogonal array design was successfully applied for determining the optimal parameter combination of API following treatment. Under the optimum orthogonal design condition, a minimum API of 19.97±2.66 subsequent to low-frequency and low-intensity mediated blood perfusion blockage was obtained. PMID:26722279

  16. Optimization of low-frequency low-intensity ultrasound-mediated microvessel disruption on prostate cancer xenografts in nude mice using an orthogonal experimental design.

    PubMed

    Yang, Y U; Bai, Wenkun; Chen, Yini; Lin, Yanduan; Hu, Bing

    2015-11-01

    The present study aimed to provide a complete exploration of the effect of sound intensity, frequency, duty cycle, microbubble volume and irradiation time on low-frequency low-intensity ultrasound (US)-mediated microvessel disruption, and to identify an optimal combination of the five factors that maximize the blockage effect. An orthogonal experimental design approach was used. Enhanced US imaging and acoustic quantification were performed to assess tumor blood perfusion. In the confirmatory test, in addition to acoustic quantification, the specimens of the tumor were stained with hematoxylin and eosin and observed using light microscopy. The results revealed that sound intensity, frequency, duty cycle, microbubble volume and irradiation time had a significant effect on the average peak intensity (API). The extent of the impact of the variables on the API was in the following order: Sound intensity; frequency; duty cycle; microbubble volume; and irradiation time. The optimum conditions were found to be as follows: Sound intensity, 1.00 W/cm(2); frequency, 20 Hz; duty cycle, 40%; microbubble volume, 0.20 ml; and irradiation time, 3 min. In the confirmatory test, the API was 19.97±2.66 immediately subsequent to treatment, and histological examination revealed signs of tumor blood vessel injury in the optimum parameter combination group. In conclusion, the Taguchi L18 (3)(6) orthogonal array design was successfully applied for determining the optimal parameter combination of API following treatment. Under the optimum orthogonal design condition, a minimum API of 19.97±2.66 subsequent to low-frequency and low-intensity mediated blood perfusion blockage was obtained.

  17. [Analysis of pulsed bioelectric activity of rabbit cerebral cortex in response to low-intensity microwave radiation].

    PubMed

    Luk'ianova, S N; Monseeva, N V

    1998-01-01

    In experiments on 22 rabbits the influence of a pulse microwave irradiation on extracellular activity of separate nervous cells of sensorimotori and occipital areas of a cortex brain is shown. The reaction could consist in activation or in braking frequency of the discharges, that was connected to frequency impulsation in an initial background. The researched mode of a microwave irradiation (1.5 GHz, duration of a pulsed-0.4 microsecond, frequency of their recurrence 1000 Hz, DFEpulsed-300 microW/sm2) had a corrigizing action.

  18. [Experimental data on reaction of neurons of the brain to low-intensity package-pulsing microwave irradiation].

    PubMed

    Moiseeva, N V

    1996-01-01

    In experiments on non-movement rabbits with help specially made from organic glass of micromanipulator and non-artefactions electrodes and wires study the bioelectrical activity separate neurons on moment of package-pulsing microwaves irradiation (1.5 GHz, duration of pulse-0.4 ms, frequency their recurrences 1000 Hz, duration of packs-16 ms, frequency their recurrences-0.12 Hz, energy-0.3 mW/sm2). The results of experiments are compared with control series, where is carried out false irradiation.

  19. Clinical Trials Involving Biphasic Pulsed Current, MicroCurrent, and/or Low-Intensity Direct Current.

    PubMed

    Houghton, Pamela E

    2014-02-01

    Significance: This invited critical review will summarize an expansive body of literature regarding electrical stimulation (ES) and wound healing. Several clinical reports have been published in which ES has been evaluated as a therapy to speed the closure of chronic wounds. Different forms of ES have been applied in varying ways and described using inconsistent terminology by researchers and clinicians around the world. It is important to compile this research and to critically appraise the findings so that clinicians who are not familiar with this field can interpret the research. Recent Advances: More recently, ES has been delivered at subsensory levels (termed microcurrent in this review) using very small electrical devices contained within wound dressing. While these newer technologies have obvious technical advances, what research has been published to date about these new devices has not produced findings that suggest this form of ES can accelerate wound closure. Critical Issues: Reviewing a collection of published reports on this subject reveals that not all forms of ES produce beneficial results. Rather, only certain ES protocols such as monophasic pulsed current applied to the wound and biphasic pulsed current current that is applied for 2 h daily to periulcer skin at intensities which produce motor responses have consistently demonstrated positive results. Future Directions: Optimal stimulus parameters and treatment schedule for ES used to treat chronic wounds need to be determined. Researchers publishing in this field should provide detailed information about their ES treatment protocol and use a similar terminology to describe the ES waveform and stimulus parameters.

  20. [The influence of pulsed low-intensity laser radiation of the red (635 nm) and infrared (904 nm) spectra on the human mesenchymal stem cells in vitro].

    PubMed

    Moskvin, S V; Kliuchnikov, D Iu; Antipov, E V; Volchkov, S E; Kiseleva, O N

    2014-01-01

    Mesenchymal stem cells (MSC) have for a long time been an object of investigation with a view to elucidating the prospects for their application in clinical medicine and cosmetology. One of the approaches to the non-specific regulation of the activity of these cells at the stage of preliminary in vitro combination is the treatment with low-intensity laser radiation (LILR). The objective of the present study was to evaluate the possibility of using pulsed LILR of the infrared and red spectra for this purpose. We used the 4th passage adhesive MSC cultures based at the umbilical tissue of a donor who gave the informed consent to participate in the study. The source of illumination was a Lazmik-VLOK laser therapeutic apparatus (RU No RZN 2014/1410 dated 06.02.2014) with the matrix laser infrared radiation heads (wavelength 904 nm, light pulse length 108 ns, frequency 1500 Hz). The apparatus was operated either in the multi-frequency Lazmik regime [Moskvin S.V., 2014] with mean power density 0.05 and 0.14 mW/cm2 and the red spectrum (wavelength 635 nm, light pulse length 144 ns, frequency 1500 Hz) or in the multi-frequency Lazmik regime [Moskvin S.V., 2014] with mean power density 0.03 and 0.12. The exposition was 5 min in both regimes. The study has demonstrated that neither the morphological structure nor the viability of mesenchymal stem cells changed under the influence of energy and time parameters used in experiments. The number of cells was shown to slightly increase in comparison with control. The most pronounced effect was documented after illumination with pulse infrared (904 nm) LILR in the multi-frequency Lazmik regime. The maximum effect was observed during a period between days 1 and 3 of cultivation.

  1. The effects of power on-off durations of pulsed ultrasound on the destruction of cancer cells.

    PubMed

    Fang, H Y; Tsai, K C; Cheng, W H; Shieh, M J; Lou, P J; Lin, W L; Chen, W S

    2007-06-01

    Low-intensity ultrasound irradiation is a potential method for suppressing cancer cell proliferation, inducing apoptosis and delivering specific cytotoxic genes or drugs into tumors topographically in future cancer therapies. However, ultrasound attenuates rapidly in tissue and produces heat. Pulsed ultrasound is frequently used to minimize pain and possible thermal damage to the surrounding normal tissue during therapy, since it results in smaller temperature increases. This study compared three pulsed-ultrasound strategies for destroying cancer cells, measuring their induced temperature increases to determine the optimal pulsing parameters. We performed three types of experiment, involving ultrasound with (1) a fixed duty cycle of 50% with variable on- and off-times, (2) a fixed off-time with variable on-times, and (3) a fixed on-time with variable off-times. The results show that for different types of cultured cells (HeLa, HT-29, Ca9-22 and fibroblast) exposed to ultrasound of the same frequency (1 MHz) and energy, long pulses combined with off-times that are 5-10 times longer (on-/-off-times pairs of 5/25, 25/250, or 250/2500 ms/ms) cause significant cell destruction whilst avoiding temperature increases of more than 1.5 degrees C. Furthermore, the correlation between the temperature increase and the percentage of surviving cells is low. Pulsed ultrasound with a long on-time and an even longer off-time exerts a high cytotoxic effect but a smaller temperature increase compared with non-pulsed ultrasound. This indicates that the cytotoxic effects observed in the current study were not purely due to the thermal effects of the ultrasound.

  2. Failure to reproduce period-dependent song cycles in Drosophila is due to poor automated pulse-detection and low-intensity courtship

    PubMed Central

    Kyriacou, Charalambos P.; Green, Edward W.; Piffer, Arianna; Dowse, Harold B.

    2017-01-01

    Stern has criticized a body of work from several groups that have independently studied the so-called “Kyriacou and Hall” courtship song rhythms of male Drosophila melanogaster, claiming that these ultradian ∼60-s cycles in the interpulse interval (IPI) are statistical artifacts that are not modulated by mutations at the period (per) locus [Stern DL (2014) BMC Biol 12:38]. We have scrutinized Stern’s raw data and observe that his automated song pulse-detection method identifies only ∼50% of the IPIs found by manual (visual and acoustic) monitoring. This critical error is further compounded by Stern’s use of recordings with very little song, the large majority of which do not meet the minimal song intensity criteria which Kyriacou and Hall used in their studies. Consequently most of Stern’s recordings only contribute noise to the analyses. Of the data presented by Stern, only perL and a small fraction of wild-type males sing vigorously, so we limited our reanalyses to these genotypes. We manually reexamined Stern’s raw song recordings and analyzed IPI rhythms using several independent time-series analyses. We observe that perL songs show significantly longer song periods than wild-type songs, with values for both genotypes close to those found in previous studies. These per-dependent differences disappear when the song data are randomized. We conclude that Stern’s negative findings are artifacts of his inadequate pulse-detection methodology coupled to his use of low-intensity courtship song records. PMID:28174268

  3. Pulmonary Capillary Hemorrhage Induced by Fixed-Beam Pulsed Ultrasound.

    PubMed

    Miller, Douglas L; Dou, Chunyan; Raghavendran, Krishnan

    2015-08-01

    The induction of pulmonary capillary hemorrhage (PCH) by pulsed ultrasound was discovered 25 y ago, but early research used fixed-beam systems rather than actual diagnostic ultrasound machines. In this study, results of exposure of rats to fixed-beam focused ultrasound for 5 min at 1.5 and 7.5 MHz were compared with recent research on diagnostic ultrasound. One exposure condition at each frequency used 10-μs pulses delivered at 25-ms intervals. Three conditions involved Gaussian modulation of the pulse amplitudes at 25-ms intervals to simulate diagnostic scanning: 7.5 MHz with 0.3- and 1.5-μs pulses at 100- and 500-μs pulse repetition periods, respectively, and 1.5 MHz with 1.7-μs pulses at 500-μs repetition periods. Four groups were tested for each condition to assess PCH areas at different exposure levels and to determine occurrence thresholds. The conditions with identical pulse timing resulted in smaller PCH areas for the smaller 7.5-MHz beam, but both had thresholds of 0.69-0.75 MPa in situ peak rarefactional pressure amplitude. The Gaussian modulation conditions for both 7.5 MHz with 0.3-μs pulses and 1.5 MHz with 1.7-μs pulses had thresholds of 1.12-1.20 MPa peak rarefactional pressure amplitude, although the relatively long 1.5-μs pulses at 7.5 MHz yielded a threshold of 0.75 MPa. The fixed-beam pulsed ultrasound exposures produced lower thresholds than diagnostic ultrasound. There was no clear tendency for thresholds to increase with increasing ultrasonic frequency when pulse timing conditions were similar.

  4. Ultrasound vibrometry using orthogonal- frequency-based vibration pulses.

    PubMed

    Zheng, Yi; Yao, Aiping; Chen, Shigao; Urban, Matthew W; Lin, Haoming; Chen, Xin; Guo, Yanrong; Chen, Ke; Wang, Tianfu; Chen, Siping

    2013-11-01

    New vibration pulses are developed for shear wave generation in a tissue region with preferred spectral distributions for ultrasound vibrometry applications. The primary objective of this work is to increase the frequency range of detectable harmonics of the shear wave. The secondary objective is to reduce the required peak intensity of transmitted pulses that induce the vibrations and shear waves. Unlike the periodic binary vibration pulses, the new vibration pulses have multiple pulses in one fundamental period of the vibration. The pulses are generated from an orthogonal-frequency wave composed of several sinusoidal signals, the amplitudes of which increase with frequency to compensate for higher loss at higher frequency in tissues. The new method has been evaluated by studying the shear wave propagation in in vitro chicken and swine liver. The experimental results show that the new vibration pulses significantly increase tissue vibration with a reduced peak ultrasound intensity, compared with the binary vibration pulses.

  5. Ultrasound Vibrometry Using Orthogonal Frequency Based Vibration Pulses

    PubMed Central

    Zheng, Yi; Yao, Aiping; Chen, Shigao; Urban, Matthew W.; Lin, Haoming; Chen, Xin; Guo, Yanrong; Chen, Ke; Wang, Tianfu; Chen, Shiping

    2014-01-01

    New vibration pulses are developed for shear wave generation in a tissue region with preferred spectral distributions for ultrasound vibrometry applications. The primary objective of this work is to increase the frequency range of detectable harmonics of the shear wave. The secondary objective is to reduce the required peak intensity of transmitted pulses that induce the vibrations and shear waves. Unlike the periodic binary vibration pulses, the new vibration pulses have multiple pulses in one fundamental period of the vibration. The pulses are generated from an orthogonal-frequency wave composed of several sinusoidal signals of which the amplitudes increase with frequency to compensate for higher loss at higher frequency in tissues. The new method has been evaluated by studying the shear wave propagation in in vitro chicken and swine liver. The experimental results show that the new vibration pulses significantly increase tissue vibration with a reduced peak ultrasound intensity, compared with the binary vibration pulses. PMID:24158291

  6. Pulsed Magneto-motive Ultrasound Imaging Using Ultrasmall Magnetic Nanoprobes

    PubMed Central

    Mehrmohammadi, Mohammad; Oh, Junghwan; Mallidi, Srivalleesha; Emelianov, Stanislav Y.

    2011-01-01

    Nano-sized particles are widely regarded as a tool to study biologic events at the cellular and molecular levels. However, only some imaging modalities can visualize interaction between nanoparticles and living cells. We present a new technique, pulsed magneto-motive ultrasound imaging, which is capable of in vivo imaging of magnetic nanoparticles in real time and at sufficient depth. In pulsed magneto-motive ultrasound imaging, an external high-strength pulsed magnetic field is applied to induce the motion within the magnetically labeled tissue and ultrasound is used to detect the induced internal tissue motion. Our experiments demonstrated a sufficient contrast between normal and iron-laden cells labeled with ultrasmall magnetic nanoparticles. Therefore, pulsed magneto-motive ultrasound imaging could become an imaging tool capable of detecting magnetic nanoparticles and characterizing the cellular and molecular composition of deep-lying structures. PMID:21439255

  7. Enhancement of Sonochemical Reaction by Dual-Pulse Ultrasound

    NASA Astrophysics Data System (ADS)

    Xu, Zheng; Yasuda, Keiji

    2011-07-01

    In order to apply sonochemistry in wastewater treatment, enhancement of sonochemical reaction is necessary. Oxidation of potassium iodide and the degradation of acid orange 7 in aqueous solution using ultrasound irradiation were performed at 490 kHz. Power-modulated pulsed waves were employed and the enhancement of reaction amount was observed compared with using continuous wave. The enhancement ratio for irradiation to rigid wall was larger than that for irradiation to free surface. Moreover, the best modulated pulsed on time was experimentally determined and the effect of the superposition of pulsed waves (dual-pulse) was studied. Enhancement was also observed and calculated separately when using dual-pulse ultrasound. The enhancement upon the use of the dual-transducer was ascribed to the enlargement of sonochemical reaction field. The enhancement upon the incorporating pulsed waves was ascribed to both the reduction of reaction threshold effect and the residual acoustical pressure at the pulsed off time.

  8. Short-term effect of low-intensity, pulsed, electromagnetic fields on gait characteristics in older adults with low bone mineral density: a pilot randomized-controlled trial.

    PubMed

    Giusti, Andrea; Giovale, Massimo; Ponte, Marco; Fratoni, Francesco; Tortorolo, Umberto; De Vincentiis, Armando; Bianchi, Gerolamo

    2013-04-01

    To evaluate the short-term effects of a 10-min exposure to low-intensity, pulsed, electromagnetic fields (PEF) on gait characteristics in older adults with low bone mineral density. In a single-center, double-blind, randomized-controlled trial, community-dwelling older adults aged ≥ 70 years were randomized (3:2 ratio) to receive a 10-min treatment with PEF (mean intensity 1.5 mW) or placebo. The following gait parameters were assessed at baseline and just after the intervention/placebo with the GAITRite Portable Walkway system: self-selected gait speed (cm/s), stride length (cm), support base (cm) and double support phase (s). In the intervention group (25 patients), both self-selected gait speed and stride length increased significantly from baseline, whereas the double support phase decreased. In the placebo group, all gait parameters except for support base remained unchanged. The mean percent increase (± standard deviation) of self-selected gait speed was significantly (P = 0.010) greater in the intervention group (20.1 ± 15.6) compared with the placebo group (10.5 ± 13.1), whereas no significant difference in the mean percent variation of the other parameters was found between the two groups. During the intervention, no adverse event was observed. A similar proportion of patients in the two groups reported one fall in the 30 days after the intervention/placebo. This is the first randomized-controlled trial showing the potential beneficial effects of PEF on gait characteristics in older adults. Further phase III randomized trials are warranted to establish their potential benefits (e.g. fall prevention) on fall-related health outcomes in elderly patients. © 2012 Japan Geriatrics Society.

  9. A pilot treatment study for mild traumatic brain injury: Neuroimaging changes detected by MEG after low-intensity pulse-based transcranial electrical stimulation.

    PubMed

    Huang, Ming-Xiong; Swan, Ashley Robb; Quinto, Annemarie Angeles; Matthews, Scott; Harrington, Deborah L; Nichols, Sharon; Bruder, Barry J; Snook, Corey C; Huang, Charles W; Baker, Dewleen G; Lee, Roland R

    2017-09-19

    Mild traumatic brain injury (mTBI) is a leading cause of sustained impairments in military service members, Veterans, and civilians. However, few treatments are available for mTBI, partially because the mechanism of persistent mTBI deficits is not fully understood. We used magnetoencephalography (MEG) to investigate neuronal changes in individuals with mTBI following a passive neurofeedback-based treatment programme called IASIS. This programme involved applying low-intensity pulses using transcranial electrical stimulation (LIP-tES) with electroencephalography monitoring. Study participants included six individuals with mTBI and persistent post-concussive symptoms (PCS). MEG exams were performed at baseline and follow-up to evaluate the effect of IASIS on brain functioning. At the baseline MEG exam, all participants had abnormal slow-waves. In the follow-up MEG exam, the participants showed significantly reduced abnormal slow-waves with an average reduction of 53.6 ± 24.6% in slow-wave total score. The participants also showed significant reduction of PCS scores after IASIS treatment, with an average reduction of 52.76 ± 26.4% in PCS total score. The present study demonstrates, for the first time, the neuroimaging-based documentation of the effect of LIP-tES treatment on brain functioning in mTBI. The mechanisms of LIP-tES treatment are discussed, with an emphasis on LIP-tES's potentiation of the mTBI healing process.

  10. The Effect of Pulsing on Transverse Ultrasound Efficiency and Chatter.

    PubMed

    Wright, Alex J; Bohner, Austin D; Bernhisel, Ashlie A; Zaugg, Brian; Barlow, William R; Pettey, Jeff H; Olson, Randall J

    2017-08-28

    To evaluate the effects of micropulse, long pulse and continuous ultrasound on transverse ultrasound using Abbott Medical Optics' (AMO) WhiteStar Signature Pro with the Ellips FX handpiece. In vitro laboratory study METHODS: This study was conducted at the John A. Moran Eye Center Laboratory, University of Utah, Salt Lake City, UT, USA. Porcine lenses were hardened in formalin for 2 hours and equilibrated in BSS over a 24-hour period. The lenses were then cubed in 2.0mm by 2.0mm pieces. These pieces were stored in BSS until the time of experimentation. The AMO WhiteStar Signature Pro machine with the Ellips FX handpiece and a 0.9mm bent dewey tip with a 30-degree bevel were used for phacoemulsification. Three runs of 20 lenses each were performed, measuring efficiency and chatter. Transverse ultrasound varied in the three runs and included continuous, 6ms on/off micropulse, and 50ms on/off long pulse. Micropulse was more efficient than long pulse by 43% (P = .00003) and continuous by 42% (P = .000387). There were also less chatter events with micropulse than with long pulse and continuous ultrasound. However, this difference did not reach significance. 6ms on and 6ms off micropulse transverse three-dimensional ultrasound is more efficient and produces less chatter events than both long pulse and continuous ultrasound. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Enhancement of the cytotoxicity and selectivity of doxorubicin to hepatoma cells by synergistic combination of galactose-decorated γ-poly(glutamic acid) nanoparticles and low-intensity ultrasound.

    PubMed

    Tsai, Wei-Bor; Lai, Hsin-Yu; Lee, Jyun-Lin; Lo, Chia-Wen; Chen, Wen-Shiang

    2014-05-20

    Specific drug delivery to solid tumors remains one of the challenges in cancer therapy. The aim of this study was to combine three drug-targeting strategies, polymer-drug conjugate, ligand presentation and ultrasound treatment, to enhance the efficacy and selectivity of doxorubicin (DXR) to hepatoma cells. The conjugation of DXR to γ-poly(glutamic acids) (γ-PGA) decreased the cytotoxicity of DXR, while the conjugation of galactosamine (Gal) to the γ-PGA-DXR conjugate restored the cytotoxic efficacy of DXR on hepatoma cells due to increased uptake of DXR. Furthermore, low-intensity ultrasound treatment increased the cell-killing ability of γ-PGA-DXR conjugates by 20%. The in vitro results showed the potential of the γ-PGA-DXR-Gal conjugate for future clinical applications.

  12. Maintenance of membrane integrity and increase of taxanes production in hazel (Corylus avellana L.) cells induced by low-intensity ultrasound.

    PubMed

    Safari, Masoumeh; Ghanati, Faezeh; Hajnoruzi, Abazar; Rezaei, Ayatollah; Abdolmaleki, Parviz; Mokhtari-Dizaji, Manigeh

    2012-06-01

    Suspension-cultured hazel cells were ultrasonicated at power densities of 4 and 455 mW for 4-40 min. Both treatments stimulated the production of major taxanes: Taxol, 10-deacetylbaccatin, and baccatin III. The highest amounts of these taxanes (0.46, 0.26, and 0.07 mg/l, respectively) were obtained at 8 and 20 min of the treatment at 455 mW. Ultrasound had no adverse effects on cell viability, growth, or membrane integrity. Increased release of taxanes by ultrasound resulted not from increased membrane permeability but more likely from stimulation of taxanes biosynthesis.

  13. COMPARATIVE STUDY OF THE EFFECTS OF LOW-LEVEL LASER AND LOW-INTENSITY ULTRASOUND ASSOCIATED WITH BIOSILICATE® ON THE PROCESS OF BONE REPAIR IN THE RAT TIBIA

    PubMed Central

    Oliveira, Poliani de; Fernandes, Kelly Rosseti; Sperandio, Evandro Fornias; Pastor, Fabio Alexandre Casarin; Nonaka, Keico Okino; Parizotto, Nivaldo Antonio; Renno, Ana Claudia Muniz

    2015-01-01

    Objective: Verify the effects of the association between Biosilicate® and ultrasound and, Biosilicate® and laser in bone consolidation process of rats, through the biomechanical and histological analysis. Methods: Forthy male rats were used. The animals were randomized into four groups (n=10): control group fracture no treated (CGF); group treated with Biosilicate® (BG); group treated with Biosilicate® and laser (BLG); group treated with Biosilicate® and ultrasound (BUG). Results: The biomechanical analysis showed no significant difference among any groups after 14 days post-surgery. In the morphometric analysis, the control group showed moderate presence of new formed bone tissue inside the defects areas and the Biosilicate® group showed similar results. Despite those facts, the biomaterial osteogenic potential was demonstrated by the great amount of cells and bone tissue around the particles. Curiously, the Biosilicate® plus laser or ultrasound groups showed lower amounts of bone tissue deposition when compared with control fracture and Biosilicate® groups. Conclusion: The data from this study can conclude that Biosilicate® was able to accelerate and optimized the bone consolidation, through the modulation of the inflammatory process and the stimulation of new bone formation. However, when resources were associated, there are no positive results. PMID:27027088

  14. Pulse sequences for uniform perfluorocarbon droplet vaporization and ultrasound imaging.

    PubMed

    Puett, C; Sheeran, P S; Rojas, J D; Dayton, P A

    2014-09-01

    Phase-change contrast agents (PCCAs) consist of liquid perfluorocarbon droplets that can be vaporized into gas-filled microbubbles by pulsed ultrasound waves at diagnostic pressures and frequencies. These activatable contrast agents provide benefits of longer circulating times and smaller sizes relative to conventional microbubble contrast agents. However, optimizing ultrasound-induced activation of these agents requires coordinated pulse sequences not found on current clinical systems, in order to both initiate droplet vaporization and image the resulting microbubble population. Specifically, the activation process must provide a spatially uniform distribution of microbubbles and needs to occur quickly enough to image the vaporized agents before they migrate out of the imaging field of view. The development and evaluation of protocols for PCCA-enhanced ultrasound imaging using a commercial array transducer are described. The developed pulse sequences consist of three states: (1) initial imaging at sub-activation pressures, (2) activating droplets within a selected region of interest, and (3) imaging the resulting microbubbles. Bubble clouds produced by the vaporization of decafluorobutane and octafluoropropane droplets were characterized as a function of focused pulse parameters and acoustic field location. Pulse sequences were designed to manipulate the geometries of discrete microbubble clouds using electronic steering, and cloud spacing was tailored to build a uniform vaporization field. The complete pulse sequence was demonstrated in the water bath and then in vivo in a rodent kidney. The resulting contrast provided a significant increase (>15 dB) in signal intensity.

  15. Analytical formula for residual current density excited in the process of gas ionization by a few-cycle laser pulse in the low-intensity limit

    NASA Astrophysics Data System (ADS)

    Silaev, A. A.; Vvedenskii, N. V.

    2015-03-01

    This work is devoted to analytical study of excitation of the residual current density (RCD) in the process of gas ionization by a few-cycle laser pulse. The RCD remains in the laser-produced plasma after the passage of the laser pulse and is as an initial push leading to excitation of the plasma oscillations which can radiate terahertz waves. We derive simple closed-form analytical formula for RCD for relatively small peak intensity of few-cycle laser pulse, which corresponds to small final degree of ionization. The dependences of the RCD on laser pulse parameters are discussed.

  16. Influence of stimulus pulse width on M-waves, H-reflexes, and torque during tetanic low-intensity neuromuscular stimulation.

    PubMed

    Lagerquist, Olle; Collins, David F

    2010-12-01

    Neuromuscular electrical stimulation (NMES) has been shown to generate contractions that include a central recruitment of motoneurons; however, the effect of pulse width on electromyographic (EMG) and torque responses during NMES are not well documented. Soleus EMG and isometric plantarflexion torque were recorded from 14 subjects with NMES delivered to the tibial nerve using 50, 200, 500, and 1000 μs pulse widths. M-waves were significantly smaller during 20 Hz NMES compared with responses evoked by single pulses of 200, 500, and 1000 μs, but not 50 μs pulse widths. At all pulse widths, stimulation at 20 Hz depressed soleus H-reflexes compared with single pulses. Two seconds of 100 Hz NMES significantly increased H-reflexes and torque during the subsequent 20 Hz NMES with 200, 500, and 1000 μs, but not 50 μs, pulse widths. NMES delivered using wide pulses generated larger contractions with a relatively greater central contribution than narrow pulses. This may help reduce atrophy and produce fatigue-resistant contractions for rehabilitation.

  17. Why Are Short Pulses More Efficient in Tissue Erosion Using Pulsed Cavitational Ultrasound Therapy (Histotripsy)?

    NASA Astrophysics Data System (ADS)

    Wang, Tzu-Yin; Maxwell, Adam D.; Park, Simone; Xu, Zhen; Fowlkes, J. Brian; Cain, Charles A.

    2010-03-01

    Histotripsy produces mechanical tissue fractionation through controlled cavitation. The histotripsy induced tissue erosion is more efficient with shorter (i.e., 3-6 cycles) rather than longer (i.e. 24 cycles) pulses. In this study, we investigated the reasons behind this observation by studying dynamics of the cavitating bubble clouds and individual bubbles during and after a therapy pulse. Bubble clouds were generated at a gel-water interface using 5 to 30-cycle 1 MHz pulses at P-/P+>19/125-MPa pressure and 1-kHz pulse repetition frequency. The evolution of the overall bubble cloud and individual bubbles were studied using high speed photography. Results show that: 1) within the first 10-15 cycles, the overall cloud grew to its maximum size; the individual bubbles underwent violent expansion and collapse, and grew in size with each cycle of ultrasound; 2) between the 15th cycle and the end of the pulse, the overall cloud size did not change even if further cycles of ultrasound were delivered; the individual bubbles no longer underwent violent collapse; 3) after the pulse, the overall cloud gradually dissolved; the individual bubbles may coalesce into larger bubbles for 0-40 μs, and then gradually dissolved. These observations suggest that violent growth and collapse of individual bubbles occur within the first few cycles of ultrasound pulse most often. This may explain why extremely short pulses are more energy efficient in histotripsy-induced tissue erosion.

  18. New coding concept for fast ultrasound imaging using pulse trains

    NASA Astrophysics Data System (ADS)

    Misaridis, Thanasis; Jensen, Joergen A.

    2002-04-01

    Frame rate in ultrasound imaging can be increased by simultaneous transmission of multiple beams using coded waveforms. However, the achievable degree of orthogonality among coded waveforms is limited in ultrasound, and the image quality degrades unacceptably due to interbeam interference. In this paper, an alternative combined time-space coding approach is undertaken. In the new method all transducer elements are excited with short pulses and the high time-bandwidth (TB) product waveforms are generated acoustically. Each element transmits a short pulse spherical wave with a constant transmit delay from element to element, long enough to assure no pulse overlapping for all depths in the image. Frequency shift keying is used for per element coding. The received signals from a point scatterer are staggered pulse trains which are beamformed for all beam directions and further processed with a bank of matched filters (one for each beam direction). Filtering compresses the pulse train to a single pulse at the scatterer position with a number of spike axial sidelobes. Cancellation of the ambiguity spikes is done by applying additional phase modulation from one emission to the next and summing every two successive images. Simulation results presented for QLFM and Costas spatial encoding schemes show that the proposed method can yield images with range sidelobes down to -45 dB using only two emissions.

  19. Pulsed ultrasound assisted dehydration of waste oil.

    PubMed

    Xie, Wei; Li, Rui; Lu, Xiaoping

    2015-09-01

    A method to aid the separation of the oil phase from waste oil emulsion of refineries had been developed by using a pulsed ultrasonic irradiation technology. Compared with conventional continuous ultrasonic irradiation, it is found that pulsed ultrasonic irradiation is much better to make water drop coalescence and hence dehydration of waste oil. The effects of ultrasonic irradiation parameters on waste oil dehydration are further discussed. The orthogonal experiment is also designed to investigate the degrees of influence of ultrasonic parameters and the optimal technological conditions. Under the optimal experimental conditions, the water content of waste oil is decreased from 65% to 8%, which thereby satisfies the requirements of refineries on the water content of waste oil after treatment (<10%). Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Enhanced therapeutic anti-inflammatory effect of betamethasone upon topical administration with low frequency, low intensity (20 kHz, 100 mW/cm2) ultrasound exposure on carrageenan-induced arthritis in mice model

    PubMed Central

    Cohen, Gadi; Natsheh, Hiba; Sunny, Youhan; Bawiec, Christopher R.; Touitou, Elka; Lerman, Melissa A.; Lazarovici, Philip; Lewin, Peter A.

    2015-01-01

    The purpose of this work was to investigate whether low frequency, low intensity (LFLI, 20 kHz, <100 mW/cm2, spatial-peak, temporal-peak) ultrasound (US), delivered by a light-weight (<100g), tether-free, fully wearable, battery powered applicator is capable of reducing inflammation in a mouse model of Rheumatoid Arthritis (RA). The therapeutic, acute, anti-inflammatory effect was estimated by the relative swelling induced in mice hind limb paws. In an independent, indirect approach, the inflammation was bio-imaged by measuring glycolytic activity with near infrared labeled 2-deoxy-glucose (2DG). The outcome of the experiments indicated that the combination of US exposure with topical application of 0.1% w/w betamethasone gel, exhibited statistically significant (p<0.05) enhanced anti-inflammatory properties in comparison with the drug or US treatment alone. The present study underscores the potential benefits of LFLI US assisted drug delivery. However, the proof of concept presented indicates the need for additional experiments to systematically evaluate and optimize the potential of, and the conditions for, safe, LFLI ultrasound promoted non-invasive drug delivery. PMID:26003010

  1. Two-dimensional Temperature Imaging Using Pulse-Echo Ultrasound

    NASA Astrophysics Data System (ADS)

    Ebbini, Emad S.

    2006-05-01

    A review of the basic principles of 2D temperature estimation using pulse-echo ultrasound is given. Some of the limitations of this technique are addressed and new solutions are described. In particular, temperature imaging artifacts due to the thermoacoustic lens effects are described. A reconstructive imaging method employing a physics-based 2D filter and a projection method is presented. Results from phantom and tissue heating experiments employing different energy sources are shown.

  2. Pulsed Ultrasound Enhances Nanoparticle Penetration into Breast Cancer Spheroids

    PubMed Central

    Grainger, Stephanie J.; Serna, Juliana Valencia; Sunny, Steffi; Zhou, Yun; Deng, Cheri X.; El-Sayed, Mohamed E.H.

    2010-01-01

    Effective treatment of solid tumors requires homogenous distribution of anticancer drugs within the entire tumor volume to deliver lethal concentrations to resistant cancer cells and tumor-initiating cancer stem cells. However, penetration of small molecular weight chemotherapeutic agents and drug-loaded polymeric and lipid particles into the hypoxic and necrotic regions of solid tumors remains a significant challenge. This article reports the results of pulsed ultrasound enhanced penetration of nano-sized fluorescent particles into MCF-7 breast cancer spheroids (300-350 μm diameter) as a function of particle size and charge. With pulsed ultrasound application in the presence of microbubbles, small (20 nm) particles achieve 6-20 folds higher penetration and concentration in the spheroid's core compared to those not exposed to ultrasound. Increase in particle size to 40 nm and 100 nm results in their effective penetration into the spheroid's core to 9 and 3 folds, respectively. In addition, anionic carboxylate particles achieved higher penetration (2.3, 3.7, and 4.7 folds) into the core (0.25r) of MCF-7 breast cancer spheroids compared to neutral (2.2, 1.9, and 2.4 folds) and cationic particles (1.5, 1.4 and 1.9 folds) upon US exposure for 30, 60, and 90 seconds under the same experimental conditions. These results demonstrate the feasibility of utilizing pulsed ultrasound to increase the penetration of nano-sized particles into MCF-7 spheroids mimicking tumor tissue. The effects of particle properties on the penetration enhancement were also illustrated. PMID:20957996

  3. Noninvasive thrombolysis using pulsed ultrasound cavitation therapy - histotripsy.

    PubMed

    Maxwell, Adam D; Cain, Charles A; Duryea, Alexander P; Yuan, Lingqian; Gurm, Hitinder S; Xu, Zhen

    2009-12-01

    Clinically available thrombolysis techniques are limited by either slow reperfusion (drugs) or invasiveness (catheters) and carry significant risks of bleeding. In this study, the feasibility of using histotripsy as an efficient and noninvasive thrombolysis technique was investigated. Histotripsy fractionates soft tissue through controlled cavitation using focused, short, high-intensity ultrasound pulses. In vitro blood clots formed from fresh canine blood were treated by histotripsy. The treatment was applied using a focused 1-MHz transducer, with five-cycle pulses at a pulse repetition rate of 1kHz. Acoustic pressures varying from 2 to 12MPa peak negative pressure were tested. Our results show that histotripsy can perform effective thrombolysis with ultrasound energy alone. Histotripsy thrombolysis only occurred at peak negative pressure >or=6MPa when initiation of a cavitating bubble cloud was detected using acoustic backscatter monitoring. Blood clots weighing 330mg were completely broken down by histotripsy in 1.5 to 5min. The clot was fractionated to debris with >96% weight smaller than 5mum diameter. Histotripsy thrombolysis treatment remained effective under a fast, pulsating flow (a circulatory model) as well as in static saline. Additionally, we observed that fluid flow generated by a cavitation cloud can attract, trap and further break down clot fragments. This phenomenon may provide a noninvasive method to filter and eliminate hazardous emboli during thrombolysis.

  4. Effects of low-intensity pulsed electromagnetic fields on bone microarchitecture, mechanical strength and bone turnover in type 2 diabetic db/db mice.

    PubMed

    Li, Jianjun; Zeng, Zhaobin; Zhao, Yantao; Jing, Da; Tang, Chuhua; Ding, Yin; Feng, Xue

    2017-09-07

    Type 2 diabetic patients have impaired bone quality, leading to increased fracture risk. Substantial evidence demonstrates that pulsed electromagnetic fields (PEMF) could resist osteopenia/osteoporosis induced by estrogen deficiency and disuse. However, the effects of PEMF on osteopenia/osteoporosis associated with diabetes, especially for more prevalent type 2 diabetes, remain poorly understood. We herein investigated the skeletal effects and mechanisms of PEMF (15 Hz, 20 Gs) on leptin receptor-deficient db/db mice with typical type 2 diabetic symptoms. Our µCT results showed that 12-week PEMF exposure significantly improved both cancellous and cortical bone microarchitecture in db/db mice. Three-point bending and biomechanical indentation testing demonstrated that PEMF improved whole-bone structural properties and tissue-level material properties in db/db mice. PEMF significantly promoted bone formation in db/db mice evidenced by increased serum osteocalcin and bone mineral apposition rate, whereas PEMF exerted no observable alteration in bone resorption. Real-time PCR showed that PEMF upregulated tibial gene expression of osteoblastogenesis-related of canonical Wnt/β-catenin signaling but not osteoclastogenesis-related RANKL-RANK signaling in db/db mice. Our findings demonstrate that PEMF improved bone quantity and quality with obvious anabolic activities in db/db mice, and imply that PEMF might become a clinically applicable treatment modality for improving bone quality in type 2 diabetic patients.

  5. Temperature-dependent photovoltage response in La0.9Li0.1MnO3/SrTiO3-Nb heterojunction induced by a low intensity pulse laser

    NASA Astrophysics Data System (ADS)

    Wang, Jianyuan; Bai, Jianying; Xing, Hui; Wang, Shuanhu; Wang, Min; Jin, Kexin; Chen, Changle

    2017-02-01

    The photovoltage response under low intensity pulse laser (473 nm) in the perovskite manganite p-n junction La0.9Li0.1MnO3/SrTiO3:Nb is investigated within a wide temperature range. The maximum photovoltage occurs at around the metal-insulator transition temperature (TMI, 250 K) of La0.9Li0.1MnO3 rather than the lowest temperature, which indicates that the low density charge induced by a weak light can be significantly affected by the leakage rather than the thermal carriers. Moreover, the time response of photovoltage shows distinct temperature-dependent and light intensity-dependent regularities in the temperature regions TTMI respectively. The mechanisms are discussed according to the charge transport and magnetic phase transition of La0.9Li0.1MnO3.

  6. Loss of gas from echogenic liposomes exposed to pulsed ultrasound

    NASA Astrophysics Data System (ADS)

    Raymond, Jason L.; Luan, Ying; Peng, Tao; Huang, Shao-Ling; McPherson, David D.; Versluis, Michel; de Jong, Nico; Holland, Christy K.

    2016-12-01

    The destruction of echogenic liposomes (ELIP) in response to pulsed ultrasound excitations has been studied acoustically previously. However, the mechanism underlying the loss of echogenicity due to cavitation nucleated by ELIP has not been fully clarified. In this study, an ultra-high speed imaging approach was employed to observe the destruction phenomena of single ELIP exposed to ultrasound bursts at a center frequency of 6 MHz. We observed a rapid size reduction during the ultrasound excitation in 139 out of 397 (35%) ultra- high-speed recordings. The shell dilation rate, which is defined as the microbubble wall velocity divided by the instantaneous radius, \\dot{{R}}  /R, was extracted from the radius versus time response of each ELIP, and was found to be correlated with the deflation. Fragmentation and surface mode vibrations were also observed and are shown to depend on the applied acoustic pressure and initial radius. Results from this study can be utilized to optimize the theranostic application of ELIP, e.g. by tuning the size distribution or the excitation frequency.

  7. Stark Widths Of Ionized Xenon UV Lines Of Low Intensity

    SciTech Connect

    Cirisan, M.; Djurovic, S.; Pelaez, R. J.; Aparicio, J. A.; Mar, S.

    2007-04-23

    Stark width measurements of several low intensity Xe II spectral lines (5d - 4f transitions) in UV region, are presented here for the first time. These measurements were obtained from helium - xenon pulsed arc plasma.

  8. Use of Ultrasound Pulses Combined with Definity for Targeted Blood-Brain Barrier Disruption

    NASA Astrophysics Data System (ADS)

    McDannold, Nathan; Vykhodtseva, Natalia; Hynynen, Kullervo

    2007-05-01

    We have developed a method to combine an ultrasound contrast agent (USCA) with low-intensity focused ultrasound pulses combined to produce temporary blood-brain barrier disruption (BBBD), a potential non-invasive means for targeted drug delivery in the brain. All of our previous work used the USCA Optison. The purpose of this work was to test the feasibility of using the USCA Definity for BBBD. Thirty-six non-overlapping locations were sonicated through a craniotomy in experiments in the brains of nine rabbits (4 locations per rabbit; US frequency: 0.69MHz, burst: 10ms, PRF: 1Hz, duration: 20s; pressure amplitude: 0.2-1.5 MPa). Eleven locations were sonicated using Optison at 0.5 MPa. For both agents, the probability for BBBD was estimated to be 50% at 0.4 MPa using probit regression. In histology, small isolated areas of extravasated erythrocytes were observed in some locations. At 0.8 MPa and above, this extravasation was sometimes accompanied by tiny (dimensions of 100 μm or less) regions of damaged brain parenchyma. The magnitude of the BBBD was larger with Optison than with Definity at 0.5 MPa (P=0.04), and more areas with extravasated erythrocytes were observed (P=0.03). We conclude that BBBD is possible using Definity for the dosage of USCA and the acoustic parameters tested in this study. While the probability for BBBD as a function of pressure amplitude and the type of acute tissue effects was similar to findings with Optison, under these experimental conditions, Optison produced a larger effect.

  9. Low Intensity Conflict: Global Challenges.

    ERIC Educational Resources Information Center

    Motley, James Berry

    1987-01-01

    Examines the increase in low intensity conflict (LIC) such as terrorism and subversion, since World War II and discusses the United States ability to deal with it. States that LICs continue to increase, making U.S. involvement inevitable. Describes necessary preparations and actions for meeting this challenge. (GEA)

  10. Pulsed Ultrasound Enhances the Killing of Escherichia coli Biofilms by Aminoglycoside Antibiotics In Vivo

    PubMed Central

    Rediske, Andrea M.; Roeder, Beverly L.; Nelson, Jared L.; Robison, Rachel L.; Schaalje, G. Bruce; Robison, Richard A.; Pitt, William G.

    2000-01-01

    Escherichia coli biofilms on two polyethylene disks were implanted subcutaneously into rabbits receiving systemic gentamicin. Ultrasound was applied for 24 h to one disk. Both disks were removed, and viable bacteria were counted. Pulsed ultrasound significantly reduced bacterial viability below that of nontreated biofilms without damage to the skin. PMID:10681355

  11. Study of the onset of the acoustic streaming in parallel plate resonators with pulse ultrasound.

    PubMed

    Castro, Angelica; Hoyos, Mauricio

    2016-03-01

    In a previous study, we introduced pulse mode ultrasound as a new method for reducing and controlling the acoustic streaming in parallel plate resonators (Hoyos and Castro, 2013). Here, by modifying other parameters such as the resonator geometry and the particle size, we have found a threshold for particle manipulation with ultrasonic standing waves in confined resonators without the influence of the acoustic streaming. We demonstrate that pulse mode ultrasound open the possibility of manipulating particles smaller than 1 μm size.

  12. Inertial cavitation initiated by polytetrafluoroethylene nanoparticles under pulsed ultrasound stimulation.

    PubMed

    Jin, Qiaofeng; Kang, Shih-Tsung; Chang, Yuan-Chih; Zheng, Hairong; Yeh, Chih-Kuang

    2016-09-01

    Nanoscale gas bubbles residing on a macroscale hydrophobic surface have a surprising long lifetime (on the order of days) and can serve as cavitation nuclei for initiating inertial cavitation (IC). Whether interfacial nanobubbles (NBs) reside on the infinite surface of a hydrophobic nanoparticle (NP) and could serve as cavitation nuclei is unknown, but this would be very meaningful for the development of sonosensitive NPs. To address this problem, we investigated the IC activity of polytetrafluoroethylene (PTFE) NPs, which are regarded as benchmark superhydrophobic NPs due to their low surface energy caused by the presence of fluorocarbon. Both a passive cavitation detection system and terephthalic dosimetry was applied to quantify the intensity of IC. The IC intensities of the suspension with PTFE NPs were 10.30 and 48.41 times stronger than those of deionized water for peak negative pressures of 2 and 5MPa, respectively. However, the IC activities were nearly completely inhibited when the suspension was degassed or ethanol was used to suspend PTFE NPs, and they were recovered when suspended in saturated water, which may indicates the presence of interfacial NBs on PTFE NPs surfaces. Importantly, these PTFE NPs could sustainably initiate IC for excitation by a sequence of at least 6000 pulses, whereas lipid microbubbles were completely depleted after the application of no more than 50 pulses under the same conditions. The terephthalic dosimetry has shown that much higher hydroxyl yields were achieved when PTFE NPs were present as cavitation nuclei when using ultrasound parameters that otherwise did not produce significant amounts of free radicals. These results show that superhydrophobic NPs may be an outstanding candidate for use in IC-related applications.

  13. Multifunctional pulse generator for high-intensity focused ultrasound system

    NASA Astrophysics Data System (ADS)

    Tamano, Satoshi; Yoshizawa, Shin; Umemura, Shin-Ichiro

    2017-07-01

    High-intensity focused ultrasound (HIFU) can achieve high spatial resolution for the treatment of diseases. A major technical challenge in implementing a HIFU therapeutic system is to generate high-voltage high-current signals for effectively exciting a multichannel HIFU transducer at high efficiencies. In this paper, we present the development of a multifunctional multichannel generator/driver. The generator can produce a long burst as well as an extremely high-voltage short pulse of pseudosinusoidal waves (trigger HIFU) and second-harmonic superimposed waves for HIFU transmission. The transmission timing, waveform, and frequency can be controlled using a field-programmable gate array (FPGA) via a universal serial bus (USB) microcontroller. The hardware is implemented in a compact printed circuit board. The test results of trigger HIFU reveal that the power consumption and the temperature rise of metal-oxide semiconductor field-effect transistors were reduced by 19.9% and 38.2 °C, respectively, from the previous design. The highly flexible performance of the novel generator/driver is demonstrated in the generation of second-harmonic superimposed waves, which is useful for cavitation-enhanced HIFU treatment, although the previous design exhibited difficulty in generating it.

  14. All-optical pulse-echo ultrasound probe for intravascular imaging (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Colchester, Richard J.; Noimark, Sacha; Mosse, Charles A.; Zhang, Edward Z.; Beard, Paul C.; Parkin, Ivan P.; Papakonstantinou, Ioannis; Desjardins, Adrien E.

    2016-02-01

    High frequency ultrasound probes such as intravascular ultrasound (IVUS) and intracardiac echocardiography (ICE) catheters can be invaluable for guiding minimally invasive medical procedures in cardiology such as coronary stent placement and ablation. With current-generation ultrasound probes, ultrasound is generated and received electrically. The complexities involved with fabricating these electrical probes can result in high costs that limit their clinical applicability. Additionally, it can be challenging to achieve wide transmission bandwidths and adequate wideband reception sensitivity with small piezoelectric elements. Optical methods for transmitting and receiving ultrasound are emerging as alternatives to their electrical counterparts. They offer several distinguishing advantages, including the potential to generate and detect the broadband ultrasound fields (tens of MHz) required for high resolution imaging. In this study, we developed a miniature, side-looking, pulse-echo ultrasound probe for intravascular imaging, with fibre-optic transmission and reception. The axial resolution was better than 70 microns, and the imaging depth in tissue was greater than 1 cm. Ultrasound transmission was performed by photoacoustic excitation of a carbon nanotube/polydimethylsiloxane composite material; ultrasound reception, with a fibre-optic Fabry-Perot cavity. Ex vivo tissue studies, which included healthy swine tissue and diseased human tissue, demonstrated the strong potential of this technique. To our knowledge, this is the first study to achieve an all-optical pulse-echo ultrasound probe for intravascular imaging. The potential for performing all-optical B-mode imaging (2D and 3D) with virtual arrays of transmit/receive elements, and hybrid imaging with pulse-echo ultrasound and photoacoustic sensing are discussed.

  15. 5. Accelerated Fracture Healing Targeting Periosteal Cells: Possibility of Combined Therapy of Low-Intensity Pulsed Ultrasound (LIPUS), Bone Graft, and Growth Factor (bFGF).

    PubMed

    Uchida, Kentaro; Urabe, Ken; Naruse, Koji; Mikuni-Takagaki, Yuko; Inoue, Gen; Takaso, Masashi

    2016-08-01

    We have studied the mechanism of fracture healing, and the effect of LIPUS, bone graft and growth factor on accelerating fracture healing. We present here the results of our research. To examine callus formation cells in fracture healing, we made marrow GFP chimera mice and a fracture model of marrow mesenchymal stem cell GFP chimera mice. It was demonstrated that periosteal cells were essential for callus formation. We focused on periosteal cells and examined the effect of LIPUS. In an in vitro experiment using a cultured part of the femur, LIPUS promoted ossification of the periosteal tissue. Further, LIPUS accelerated VEGF expression in the experiment using the femoral fracture model of mice. From these results, it was suggested that activation of periosteal cells might play a role in the fracture healing mechanism of LIPUS. Next, we discussed the possibility of combined therapy of LIPUS, bone graft and growth factor. Therapy involving the topical administration of bFGF using a controlled release system and bone graft could promote callus formation. In addition, LIPUS was able to promote membranaceous ossification after the bone graft. It was suggested that combined therapy of LIPUS, bone graft and bFGF could be a new option for treating fractures.

  16. GPU simulation of nonlinear propagation of dual band ultrasound pulse complexes

    SciTech Connect

    Kvam, Johannes Angelsen, Bjørn A. J.; Elster, Anne C.

    2015-10-28

    In a new method of ultrasound imaging, called SURF imaging, dual band pulse complexes composed of overlapping low frequency (LF) and high frequency (HF) pulses are transmitted, where the frequency ratio LF:HF ∼ 1 : 20, and the relative bandwidth of both pulses are ∼ 50 − 70%. The LF pulse length is hence ∼ 20 times the HF pulse length. The LF pulse is used to nonlinearly manipulate the material elasticity observed by the co-propagating HF pulse. This produces nonlinear interaction effects that give more information on the propagation of the pulse complex. Due to the large difference in frequency and pulse length between the LF and the HF pulses, we have developed a dual level simulation where the LF pulse propagation is first simulated independent of the HF pulse, using a temporal sampling frequency matched to the LF pulse. A separate equation for the HF pulse is developed, where the the presimulated LF pulse modifies the propagation velocity. The equations are adapted to parallel processing in a GPU, where nonlinear simulations of a typical HF beam of 10 MHz down to 40 mm is done in ∼ 2 secs in a standard GPU. This simulation is hence very useful for studying the manipulation effect of the LF pulse on the HF pulse.

  17. Arterial pulse wave propagation velocity in healthy dogs by pulse wave Doppler ultrasound.

    PubMed

    Nogueira, Rodrigo B; Pereira, Lucas A; Basso, Alice F; da Fonseca, Ingrid S; Alves, Lorena A

    2017-03-01

    The aim of this study was to prospectively evaluate the carotid-femoral pulse wave velocity (PWV) values in healthy dogs using pulse wave Doppler ultrasound. A secondary aim was to determine the feasibility of this method and to report the intra- and interobserver reproducibilities of the PWV in conscious dogs. The data were studied in 30 healthy, adult, male (n = 15) and female (n = 15) dogs. The time interval marked between the R wave peak of the electrocardiogram and the intersection of the blood flow wave upstroke of the Doppler spectrum with the baseline of zero frequency was determined for the carotid (T1) and for the femoral (T2) arteries. The distance covered by the pulse wave (L) was determined. The PWV was then calculated using the following formula: L/T2 - T1. The mean values of PWV calculated from the total sample (n = 30) evaluated were 13.41 ± 2.20 m/s. No significant statistical difference was observed for the PWV measurements between males (14.82 ± 3.18 m/s) and females (12.64 ± 2.45 m/s). The analysis revealed no intra nor interobserver differences. A reasonable reproducibility of the PWV measurements was showed by intraclass correlation coefficients (ICC), and the coefficients of variation (CV). These data demonstrate that noninvasive vascular Doppler analysis is a feasible and reproducible method to determine the carotid-femoral PWV in dogs.

  18. Alternate pulses of ultrasound and electricity enhanced electrochemical process for p-nitrophenol degradation.

    PubMed

    Xie, Fengchun; Xu, Yun; Xia, Kunyuan; Jia, Caixia; Zhang, Pin

    2016-01-01

    A novel alternated ultrasonic and electric pulse enhanced electrochemical process was developed and used for investigating its effectiveness on the degradation of p-nitrophenol (PNP) in an aqueous solution. The impacts of pulse mode, pH, cell voltage, supporting electrolyte concentration, ultrasonic power and the initial concentration of PNP on the performance of PNP degradation were evaluated. Possible pathway of PNP degradation in this system was proposed based on the intermediates identified by GC-MS. Experimental results showed that 94.1% of PNP could be removed at 2h in the dual-pulse ultrasound enhanced electrochemical (dual-pulse US-EC) process at mild operating conditions (i.e., pulse mode of electrochemical pulse time (TEC)=50 ms and ultrasonic pulse time (T US)=100 ms, initial pH of 3.0, cell voltage of 10 V, Na2SO4 concentration of 0.05 M, ultrasonic powder of 48.8 W and initial concentration of PNP of 100mg/L), compared with 89.0%, 58.9%, 2.4% in simultaneous ultrasound enhanced electrochemical (US-EC) process, pulsed electrochemical (EC) process and pulsed ultrasound (US), respectively. Moreover, energy used in the dual-pulse US-EC process was reduced by 50.4% as compared to the US-EC process. The degradation of PNP in the pulsed EC process, US-EC process and dual-pulse process followed pseudo-first-order kinetics. Therefore, the dual-pulse US-EC process was found to be a more effective technique for the degradation of PNP and would have a promising application in wastewater treatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Comparison of Thresholds for Pulmonary Capillary Hemorrhage Induced by Pulsed-wave and B-mode Ultrasound

    NASA Astrophysics Data System (ADS)

    Miller, Douglas L.; Dou, Chunyan; Raghavendran, Krishnan

    Pulsed ultrasound was found to induce pulmonary capillary hemorrhage (PCH) in mice about 25 years ago but remains a poorly understood risk factor for pulmonary diagnostic ultrasound. In early research using laboratory fixed beam ultrasound, thresholds for PCH had frequency variation from 1-4 MHz similar to the Mechanical Index. In recent research, thresholds for B mode diagnostic ultrasound from 1.5-12 MHz had little dependence on frequency. To compare the diagnostic ultrasound method to laboratory pulsed exposure, thresholds for fixed beam ultrasound were determined using comparable methods at 1.5 and 7.5 MHz. PCH thresholds were lower for simple fixed-beam pulse modes than for B mode and in approximate agreement with early research. However, for comparable timing parameters, PCH thresholds had little dependence on ultrasonic frequency. These findings suggest that the MI may not be directly useful as a dosimetric parameter for safety guidance in pulmonary ultrasound.

  20. Hadamard-Encoded Multi-Pulses for Contrast-Enhanced Ultrasound Imaging.

    PubMed

    Gong, Ping; Song, Pengfei; Chen, Shigao

    2017-08-30

    The development of contrast-enhanced ultrasound (CEUS) imaging offers great opportunities for new ultrasound clinical applications such as myocardial perfusion imaging and abdominal lesion characterization. In CEUS imaging, the contrast agents (i.e., microbubbles) are utilized to improve the contrast between blood and tissue based on their high nonlinearity under low ultrasound pressure. In this paper, we propose a new CEUS pulse sequence by combining Hadamard-encoded multi-pulses (HEM) with fundamental frequency bandpass filter (i.e., filter centered on transmit frequency). HEM consecutively emits multi-pulses encoded by a second-order Hadamard matrix in each of the two transmission events (i.e., pulse-echo events), as opposed to conventional CEUS methods which emit individual pulses in two separate transmission events (i.e., pulse inversion, amplitude modulation, and pulse inversion amplitude modulation combined). In HEM imaging, the microbubble responses can be improved by the longer transmit pulse, and the tissue harmonics can be suppressed by the fundamental frequency filter, leading to significantly improved contrast-to-tissue ratio (CTR) and signal-to-noise ratio (SNR). In addition, the fast polarity change between consecutive coded pulse emissions excites strong nonlinear microbubble echoes, further enhancing the CEUS image quality. The spatial resolution of HEM image is compromised as compared to other microbubble imaging methods due to the longer transmit pulses and the lower imaging frequency (i.e., fundamental frequency). However, the resolution loss was shown to be negligible and could be offset by the significantly enhanced CTR, SNR and penetration depth. These properties of HEM can potentially facilitate robust CEUS imaging for a many clinical applications, especially for deep abdominal organs and heart.

  1. COMPARATIVE STUDY OF THE EFFECTS OF LOW-LEVEL LASER AND LOW-INTENSITY ULTRASOUND ASSOCIATED WITH BIOSILICATE(®) ON THE PROCESS OF BONE REPAIR IN THE RAT TIBIA.

    PubMed

    Oliveira, Poliani de; Fernandes, Kelly Rosseti; Sperandio, Evandro Fornias; Pastor, Fabio Alexandre Casarin; Nonaka, Keico Okino; Parizotto, Nivaldo Antonio; Renno, Ana Claudia Muniz

    2012-01-01

    Verify the effects of the association between Biosilicate® and ultrasound and, Biosilicate® and laser in bone consolidation process of rats, through the biomechanical and histological analysis. Forthy male rats were used. The animals were randomized into four groups (n=10): control group fracture no treated (CGF); group treated with Biosilicate® (BG); group treated with Biosilicate® and laser (BLG); group treated with Biosilicate® and ultrasound (BUG). The biomechanical analysis showed no significant difference among any groups after 14 days post-surgery. In the morphometric analysis, the control group showed moderate presence of new formed bone tissue inside the defects areas and the Biosilicate® group showed similar results. Despite those facts, the biomaterial osteogenic potential was demonstrated by the great amount of cells and bone tissue around the particles. Curiously, the Biosilicate® plus laser or ultrasound groups showed lower amounts of bone tissue deposition when compared with control fracture and Biosilicate® groups. The data from this study can conclude that Biosilicate® was able to accelerate and optimized the bone consolidation, through the modulation of the inflammatory process and the stimulation of new bone formation. However, when resources were associated, there are no positive results.

  2. Pulsed Ultrasound Fails To Diminish Delayed-Onset Muscle Soreness Symptoms

    PubMed Central

    Stay, Jeffrey C.; Richard, Mark D.; Draper, David O.; Schulthies, Shane S.; Durrant, Earlene

    1998-01-01

    Objective: We investigated the effects of pulsed ultrasound on swelling, muscle soreness perception, relaxed-elbow extension angle, and muscular strength. Design and Setting: Eight sets of concentric and eccentric actions induced delayed-onset muscle soreness of the elbow flexors. Group 1 received 20% pulsed ultrasound treatments (1-MHz, 7 minutes, 1.5 W/ cm2 temporal peak intensity) twice a day immediately after postexercise assessments and at 3, 24, 27, 48, 51, 72, and 75 hours postexercise. Group 2 received sham treatments immediately after postexercise assessments and at 3,27, 51, and 75 hours postexercise and true treatments of pulsed ultrasound at 24, 48, and 72 hours postexercise. Group 3 received sham treatments of no ultrasonic output immediately after postexercise assessments and at 3, 24, 27, 48, 51, 72, and 75 hours postexercise. Subjects: Thirty-six college-age females. Measurements: We recorded upper-arm circumference, perceived soreness, relaxed-elbow extension angle, and elbow-flexion strength before (pretest), immediately postexercise, and at 24, 48, 72, and 96 hours postexercise. Results: We noted differences over time but no treatment effect between groups or interactions between time and group for upper-arm circumference, perceived soreness, relaxed-elbow extension angle, or elbow-flexion strength. Conclusions: Pulsed ultrasound as used in this study did not significantly diminish the effects of delayed-onset muscle soreness on soreness perception, swelling, relaxed-elbow extension angle, and strength. PMID:16558532

  3. Direct Measurement of Basilar Membrane Motion Using Pulsed-Wave Doppler High-Frequency Ultrasound

    NASA Astrophysics Data System (ADS)

    Torbatian, Z.; Garland, P.; Adamson, R. B. A.; Bance, M.; Brown, J. A.

    2011-11-01

    We present a preliminary report on the use of a new technique for measuring the motion of the basilar membrane, high-frequency ultrasound Doppler vibrometry. Using a custom-built, 1 mm diameter probe, we collected ultrasonic reflections from intracochlear structures and applied pulsed-wave Doppler vibrometry to measure the basilar membrane response to pressure applied in the ear canal.

  4. Understanding ultrasound induced sonoporation: definitions and underlying mechanisms.

    PubMed

    Lentacker, I; De Cock, I; Deckers, R; De Smedt, S C; Moonen, C T W

    2014-06-01

    In the past two decades, research has underlined the potential of ultrasound and microbubbles to enhance drug delivery. However, there is less consensus on the biophysical and biological mechanisms leading to this enhanced delivery. Sonoporation, i.e. the formation of temporary pores in the cell membrane, as well as enhanced endocytosis is reported. Because of the variety of ultrasound settings used and corresponding microbubble behavior, a clear overview is missing. Therefore, in this review, the mechanisms contributing to sonoporation are categorized according to three ultrasound settings: i) low intensity ultrasound leading to stable cavitation of microbubbles, ii) high intensity ultrasound leading to inertial cavitation with microbubble collapse, and iii) ultrasound application in the absence of microbubbles. Using low intensity ultrasound, the endocytotic uptake of several drugs could be stimulated, while short but intense ultrasound pulses can be applied to induce pore formation and the direct cytoplasmic uptake of drugs. Ultrasound intensities may be adapted to create pore sizes correlating with drug size. Small molecules are able to diffuse passively through small pores created by low intensity ultrasound treatment. However, delivery of larger drugs such as nanoparticles and gene complexes, will require higher ultrasound intensities in order to allow direct cytoplasmic entry.

  5. Characterization and Ultrasound-Pulse Mediated Destruction of Ultrasound Contrast Microbubbles

    NASA Astrophysics Data System (ADS)

    Sarkar, Kausik; Jain, Pankaj; Chatterjee, Dhiman

    2006-05-01

    Intravenously injected encapsulated microbubbles improve the contrast of an ultrasound image. Their destruction is used in measuring blood flow, stimulating arteriogenesis, and drug delivery. We measure attenuation and scattering of ultrasound through solution of commercial contrast agents such as Sonazoid and Definity. We have developed a number of different interfacial rheology models for the encapsulation of such microbubbles. By matching with experimentally measured attenuation, we obtain the characteristic rheological parameters. We compare model predictions with measured subharmonic responses. We also investigate microbubble destruction under acoustic excitation by measuring time-varying attenuation data.

  6. Application of MR-guided focused pulsed ultrasound for destroying clots in vitro using thrombolytic drugs

    NASA Astrophysics Data System (ADS)

    Hadjisavvas, V.; Ioannides, K.; Damianou, C.

    2011-09-01

    In this paper an MR-guided focused pulsed ultrasound system for the treatment of stroke using thrombolytic drugs in a model in vitro is presented. A single element spherically focused transducer of 5 cm diameter; focusing at 10 cm and operating at 0.5 MHz or 1 MHz was used. The transducer was mounted in an MR compatible robot. The artery was modelled using a silicone tube. Tissue was modelled using polyaclylimide gel. Coagulated blood was used to model thrombus. A thermocouple was placed in the thrombus in order to measure the thrombus temperature. The effect of power, beam, and frequency was investigated. The goal was to maintain a temperature increase of less than 1 °C during the application of pulse ultrasound (called safe temperature). With the application of ultrasound alone there was no notable destruction of the thrombus. With the combination of ultrasound and thrombolytic drugs destruction occurred after 60 mins of pulse exposure (PRF = 1 s, duty factor = 10%, and with thrombus placed at 1 cm deep in the tissue). This simple in vitro model was proven very successful for evaluating MRgFUS as a modality for treating stroke. In the future we plan to apply this treatment protocol in live animals and humans.

  7. Pulsed-ultrasound tagging of light in living tissues

    NASA Astrophysics Data System (ADS)

    Lev, Aner; Rubanov, E.; Pomerantz, Ami; Sfez, Bruno G.

    2004-07-01

    Ultrasound can be used in order to locally modulate, or tag, light in a turbid medium. This tagging process is made possible due to the extreme sensitivity of laser speckle distribution to minute changes within the medium. This hybrid technique presents several advantages compared to all-optical tomographic techniques, in that the image resolution is fixed by the ultrasound focus diameter. To our best knowledge, only in vitro experiments have been performed, either on tissue-like phantoms or meat. However a strong difference exists between these sample and living tissues. In living tissues, different kind of liquids flow through the capillaries, strongly reducing the sspeckle autocorrelation time. We have performed experiments on both mice and humans, showing that the autocorrelation time is much shorter than what was previously thought. We show however that it is possible to obtain signal with acceptable signal to noise ratio down to a few cm depth. We will also discuss the origin and characteristics of the speckle noise.

  8. Surfactant shedding and gas diffusion during pulsed ultrasound through a microbubble contrast agent suspension.

    PubMed

    O'Brien, Jean-Pierre; Stride, Eleanor; Ovenden, Nicholas

    2013-08-01

    Interest in coated microbubbles as agents for therapeutic and quantitative imaging applications in biomedical ultrasound has increased the need for their accurate theoretical characterization. Effects such as gas diffusion, variation in the properties of the coating and the resulting changes in bubble behavior under repeated exposure to ultrasound pulses are, however, still not well understood. In this study, a revised equation for microbubble motion is proposed that includes the effects of gas diffusion, as well as adsorption, desorption and shedding of a surfactant from the bubble surface. This is incorporated into a nonlinear wave propagation model to account for these additional time dependent effects in the response of microbubble populations. The results from the model indicate there can be significant changes in both bubble behavior and the propagated pulse over time. This is in agreement with existing experimental data but is not predicted by existing propagation models. The analysis indicates that changes in bubble dynamics are dominated by surfactant shedding on the timescale of a diagnostic ultrasound pulse and gas diffusion over the timescale of the pulse repetition frequency. The implications of these results for the development of more accurate algorithms for quantitative imaging and for therapeutic applications are discussed.

  9. Low intensity blood flow restriction training: a meta-analysis.

    PubMed

    Loenneke, Jeremy P; Wilson, Jacob M; Marín, Pedro J; Zourdos, Michael C; Bemben, Michael G

    2012-05-01

    The primary objective of this investigation was to quantitatively identify which training variables result in the greatest strength and hypertrophy outcomes with lower body low intensity training with blood flow restriction (LI-BFR). Searches were performed for published studies with certain criteria. First, the primary focus of the study must have compared the effects of low intensity endurance or resistance training alone to low intensity exercise with some form of blood flow restriction. Second, subject populations had to have similar baseline characteristics so that valid outcome measures could be made. Finally, outcome measures had to include at least one measure of muscle hypertrophy. All studies included in the analysis utilized MRI except for two which reported changes via ultrasound. The mean overall effect size (ES) for muscle strength for LI-BFR was 0.58 [95% CI: 0.40, 0.76], and 0.00 [95% CI: -0.18, 0.17] for low intensity training. The mean overall ES for muscle hypertrophy for LI-BFR training was 0.39 [95% CI: 0.35, 0.43], and -0.01 [95% CI: -0.05, 0.03] for low intensity training. Blood flow restriction resulted in significantly greater gains in strength and hypertrophy when performed with resistance training than with walking. In addition, performing LI-BFR 2-3 days per week resulted in the greatest ES compared to 4-5 days per week. Significant correlations were found between ES for strength development and weeks of duration, but not for muscle hypertrophy. This meta-analysis provides insight into the impact of different variables on muscular strength and hypertrophy to LI-BFR training.

  10. Ultrasound treatment of nonunion of the hook of the hamate in sports activities.

    PubMed

    Fujioka, Hiroyuki; Tanaka, Juichi; Yoshiya, Shinichi; Tsunoda, Masaya; Fujita, Kenji; Matsui, Nobuzo; Makino, Takeshi; Kurosaka, Masahiro

    2004-03-01

    Two cases of nonunion of the hook of the hamate were treated with low-intensity pulsed ultrasound. The patients were baseball players and had been injured as a result of hitting repeatedly. Nonunion was detected on computed tomography (CT) and was exposed to ultrasound for 20 min a day for 4 months. In both cases pain at the hypothenar eminence disappeared, and bone union was confirmed on CT at the end of the ultrasound treatment.

  11. Effect of pulsed and continuous therapeutic ultrasound on healthy skeletal muscle in rats

    PubMed Central

    Vásquez, Bélgica; Navarrete, Javiera; Farfán, Emilio; Cantín, Mario

    2014-01-01

    Ultrasound therapy is used to treat injuries in joints, nerves and tendons. Part of the radiation generated is absorbed by nearby undamaged tissues, such as muscles. The aim was to evaluate histomorphological changes in the healthy gastrocnemius muscle in rats irradiated with continuous ultrasound (CUS) and pulsed ultrasound (PUS). Healthy adult rats were used, separated into two groups: CUS and PUS. Both were irradiated in the gastrocnemius muscle for 10 days: the CUS group in continuous mode (3 MHz, 1.0 W/cm2, 1 min/session) and the PUS group in pulsed mode (3 MHz, 1.0 W/cm2, 100 Hz, 50% duty cycle, 1 min/session). The contralateral muscles were used as a control. Their histological characteristics were analyzed, and the area and perimeter of the muscle fibers were measured. The connective tissue showed no histological changes. The area of muscle fibers of the irradiated groups was significantly greater (CUS 1325.2±182.1 μm2, p=0.0278 and PUS 1019.4±125.3 μm2, p=0.0398) than the control, and the CUS area was greater than the PUS (p=0.0383). The perimeter of muscle fibers showed significant differences between the irradiated groups (CUS 148±11.12 μm, p=0.0178 and PUS 129.3±8.83 μm, p=0.0236) compared to the control, as well as differences between CUS and PUS (p=0.0319). The application of ultrasound on healthy muscle produces hypertrophy of the muscle fibers, greater when continuous mode is used. It is advisable to apply pulsed, focused ultrasound therapies with sound heads sufficient for the tissue or zone to be treated, thereby reducing the risk of altering the adjacent healthy tissue. PMID:24551303

  12. Low intensity infrared laser induces filamentation in Escherichia coli cells

    NASA Astrophysics Data System (ADS)

    Fonseca, A. S.; Presta, G. A.; Geller, M.; Paoli, F.

    2011-10-01

    Low intensity continuous wave and pulsed emission modes laser is used in treating many diseases and the resulting biostimulative effect on tissues has been described, yet the photobiological basis is not well understood. The aim of this wok was to evaluate, using bacterial filamentation assay, effects of laser on Escherichia coli cultures in exponential and stationary growth phase. E. coli cultures, proficient and deficient on DNA repair, in exponential and stationary growth phase, were exposed to low intensity infrared laser, aliquots were spread onto microscopic slides, stained by Gram method, visualized by optical microscopy, photographed and percentage of bacterial filamentation were determined. Low intensity infrared laser with therapeutic fluencies and different emission modes can induce bacterial filamentation in cultures of E. coli wild type, fpg/ mutM, endonuclease III and exonuclease III mutants in exponential and stationary growth phase. This study showed induction of bacterial, filamentation in E. coli cultures expose to low intensity infrared laser and attention to laser therapy protocols, which should take into account fluencies, wavelengths, tissue conditions, and genetic characteristics of cells before beginning treatment.

  13. Pulsed ultrasound modulated optical tomography with harmonic lock-in holography detection.

    PubMed

    Ruan, Haowen; Mather, Melissa L; Morgan, Stephen P

    2013-07-01

    A method that uses digital heterodyne holography reconstruction to extract scattered light modulated by a single-cycle ultrasound (US) burst is demonstrated and analyzed. An US burst is used to shift the pulsed laser frequency by a series of discrete harmonic frequencies which are then locked on a CCD. The analysis demonstrates that the unmodulated light's contribution to the detected signal can be canceled by appropriate selection of the pulse repetition frequency. It is also shown that the modulated signal can be maximized by selecting a pulse sequence which consists of a pulse followed by its inverted counterpart. The system is used to image a 12 mm thick chicken breast with 2 mm wide optically absorbing objects embedded at the midplane. Furthermore, the method can be revised to detect the nonlinear US modulated signal by locking at the second harmonic US frequency.

  14. Low Intensity Conflict: A Selected Bibliography

    DTIC Science & Technology

    1992-05-01

    175. (Periodical) Hanke, James S., and Crerar, John H . "Shifting Threat Moves toward Lower Intensity Conflicts." SIGNAL, Vol. 45, December 1990, pp...Brassey’s, 1990. (U240 P38 1990) Pfaltzgraff, Robert L., Jr., and Shultz, Richard H ., Jr., eds. THE UNITED STATES ARMY: CHALLENGES AND MISSIONS FOR...8: "Doctrine and Forces for Low-Intensity Conflict," by Richard H . Shultz, Jr. Schroer, David J. SUCCESS IN LOW INTENSITY CONFLICT: CON- CLUSIONS

  15. Operational Art and Low Intensity Conflict

    DTIC Science & Technology

    1987-03-23

    LfSHAHY R£S£ ASCH REPGfiTS DIVJ8I0H mmEm. m.mHmh CLIC PAPERS OPERATIONAL ART IN LOW INTENSITY CONFLICT Army-Air Force Center for Low Intensity...this long-term nature. TABLE A Indo China I 1946 -54 Malaya 1948-60 Indo-China II 1962-75 - Algeria 1954-62 Cuba 1956-59 Zimbabwe 1969-79 17

  16. Pulsed radiofrequency on radial nerve under ultrasound guidance for treatment of intractable lateral epicondylitis.

    PubMed

    Oh, Dae Seok; Kang, Tae Hyung; Kim, Hyae Jin

    2016-06-01

    Lateral epicondylitis is a painful and functionally limiting disorder. Although lateral elbow pain is generally self-limiting, in a minority of people symptoms persist for a long time. When various conservative treatments fail, surgical approach is recommended. Surgical denervation of several nerves that innervate the lateral humeral epicondyle could be considered in patients with refractory pain because it denervates the region of pain. Pulsed radiofrequency is a minimally invasive procedure that improves chronic pain when applied to various neural tissues without causing any significant destruction and painful complication. This procedure is safe, minimally invasive, and has less risk of complications relatively compared to the surgical approach. The radial nerve can be identified as a target for pulsed radiofrequency lesioning in lateral epicondylitis. This innovative method of pulsed radiofrequency applied to the radial nerve has not been reported before. We reported on two patients with intractable lateral epicondylitis suffering from elbow pain who did not respond to nonoperative treatments, but in whom the ultrasound-guided pulsed radiofrequency neuromodulation of the radial nerve induced symptom improvement. After a successful diagnostic nerve block, radiofrequency probe adjustment around the radial nerve was performed on the lateral aspect of the distal upper arm under ultrasound guidance and multiple pulsed treatments were applied. A significant reduction in pain was reported over the follow-up period of 12 weeks.

  17. Pulsed magneto-motive ultrasound imaging to detect intracellular trafficking of magnetic nanoparticles

    PubMed Central

    Mehrmohamamdi, Mohammad; Qu, Min; Ma, Li L.; Romanovicz, Dwight K.; Johnston, Keith P.; Sokolov, Konstantin V.; Emelianov, Stanislav Y.

    2012-01-01

    As applications of nanoparticles in medical imaging and biomedicine rapidly expand, the interactions of nanoparticles with living cells have become an area of active interest. For example, intracellular trafficking of nanoparticles – an important part of cell-nanoparticle interaction, has been well studied using plasmonic nanoparticles and optical or optics-based techniques due to the change in optical properties of the nanoparticle aggregates. However, magnetic nanoparticles, despite their wide range of clinical applications, do not exhibit plasmonic-resonant properties and therefore their intracellular aggregation cannot be detected by optics-based imaging techniques. In this study, we investigated the feasibility of a novel imaging technique – pulsed magneto-motive ultrasound (pMMUS), to identify intracellular trafficking of endocytosed magnetic nanoparticles. In pulsed magneto-motive ultrasound imaging a focused, high intensity, pulsed magnetic field is used to excite the cells labeled with magnetic nanoparticles, and ultrasound imaging is then used to monitor the mechanical response of the tissue. We demonstrated previously that clusters of magnetic nanoparticles amplify the pMMUS signal in comparison to signal from individual nanoparticles. Here we further demonstrate that pMMUS imaging can identify interaction between magnetic nanoparticles and living cells, i.e. intracellular aggregation of nanoparticles within the cells. The results of our study suggest that pMMUS imaging can not only detect the presence of magnetic nanoparticles but also provides information about their intracellular trafficking non-invasively and in real-time. PMID:21926454

  18. Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials

    PubMed Central

    Maxwell, Adam D.; Cain, Charles A.; Hall, Timothy L.; Fowlkes, J. Brian; Xu, Zhen

    2012-01-01

    In this article, the negative pressure values at which inertial cavitation consistently occurs in response to a single, 2-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex-vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (Pcav) for a single pulse as a function of peak negative pressure (p−) followed a sigmoid curve, with the probability approaching 1 when the pressure amplitude was sufficient. The statistical threshold (defined as Pcav = 0.5) was between p− = 26.0–30.0 MPa in all samples with a high water content, but varied between p− = 13.7 to > 36 MPa for other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p− = 28.2 MPa was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at different pressure levels and dimensions of cavitation-induced lesions in tissue. PMID:23380152

  19. Probability of cavitation for single ultrasound pulses applied to tissues and tissue-mimicking materials.

    PubMed

    Maxwell, Adam D; Cain, Charles A; Hall, Timothy L; Fowlkes, J Brian; Xu, Zhen

    2013-03-01

    In this study, the negative pressure values at which inertial cavitation consistently occurs in response to a single, two-cycle, focused ultrasound pulse were measured in several media relevant to cavitation-based ultrasound therapy. The pulse was focused into a chamber containing one of the media, which included liquids, tissue-mimicking materials, and ex vivo canine tissue. Focal waveforms were measured by two separate techniques using a fiber-optic hydrophone. Inertial cavitation was identified by high-speed photography in optically transparent media and an acoustic passive cavitation detector. The probability of cavitation (P(cav)) for a single pulse as a function of peak negative pressure (p(-)) followed a sigmoid curve, with the probability approaching one when the pressure amplitude was sufficient. The statistical threshold (defined as P(cav) = 0.5) was between p(-) = 26 and 30 MPa in all samples with high water content but varied between p(-) = 13.7 and >36 MPa in other media. A model for radial cavitation bubble dynamics was employed to evaluate the behavior of cavitation nuclei at these pressure levels. A single bubble nucleus with an inertial cavitation threshold of p(-) = 28.2 megapascals was estimated to have a 2.5 nm radius in distilled water. These data may be valuable for cavitation-based ultrasound therapy to predict the likelihood of cavitation at various pressure levels and dimensions of cavitation-induced lesions in tissue.

  20. Stable cavitation induces increased cytoplasmic calcium in L929 fibroblasts exposed to 1-MHz pulsed ultrasound.

    PubMed

    Tsukamoto, Akira; Higashiyama, Satoru; Yoshida, Kenji; Watanabe, Yoshiaki; Furukawa, Katsuko S; Ushida, Takashi

    2011-12-01

    An increase in cytoplasmic calcium (Ca(2+) increase) is a second messenger that is often observed under ultrasound irradiation. We hypothesize that cavitation is a physical mechanism that underlies the increase in Ca(2+) in these experiments. To control the presence of cavitation, the wave type was controlled in a sonication chamber. One wave type largely contained a traveling wave (wave type A) while the other wave type largely contained a standing wave (wave type B). Fast Fourier transform (FFT) analysis of a sound field produced by the wave types ascertained that stable cavitation was present only under wave type A ultrasound irradiation. Under the two controlled wave types, the increase in Ca(2+) in L929 fibroblasts was observed with fluorescence imaging. Under wave type A ultrasound irradiation, an increase in Ca(2+) was observed; however, no increase in Ca(2+) was observed under wave type B ultrasound irradiation. We conclude that stable cavitation is involved in the increase of Ca(2+) in cells subjected to pulsed ultrasound.

  1. Ultrasound-modulated optical imaging using a photorefractive interferometer and a powerful long pulse laser

    NASA Astrophysics Data System (ADS)

    Rousseau, Guy; Blouin, Alain; Monchalin, Jean-Pierre

    2009-02-01

    Ultrasound-modulated optical imaging is an emerging biodiagnostic technique which provides the optical spectroscopic signature and the spatial localization of an optically absorbing object embedded in a strongly scattering medium. The transverse resolution of the technique is determined by the lateral extent of ultrasound beam focal zone while the axial resolution is obtained by using short ultrasound pulses. The practical application of this technique is presently limited by its poor sensitivity. Moreover, any method to enhance the signal-to-noise ratio must satisfy the biomedical safety limits. In this paper, we propose to use a pulsed single-frequency laser source to raise the optical peak power applied to the scattering medium and to collect more ultrasonically tagged photons. Such a laser source allows illuminating the tissues mainly during the transit time of the ultrasonic wave. A single-frequency Nd:YAG laser emitting 500-μs pulses with a peak power superior to 100 W was used. Tagged photons were detected with a GaAs photorefractive interferometer characterized by a large optical etendue. When pumped by high intensity laser pulses, such an interferometer provides the fast response time essential to obtain an apparatus insensitive to the speckle decorrelation encountered in biomedical applications. Consequently, the combination of a large-etendue photorefractive interferometer with a high-power pulsed laser could allow obtaining both the sensitivity and the fast response time necessary for biomedical applications. Measurements performed in 30- and 60-mm thick optical phantoms made of titanium dioxide particles dispersed in sunflower oil are presented. Results obtained in 30- and 60-mm thick chicken breast samples are also reported.

  2. An efficient pulse compression method of chirp-coded excitation in medical ultrasound imaging.

    PubMed

    Yoon, Changhan; Lee, Wooyoul; Chang, Jin; Song, Tai-kyong; Yoo, Yangmo

    2013-10-01

    Coded excitation can improve the SNR in medical ultrasound imaging. In coded excitation, pulse compression is applied to compress the elongated coded signals into a short pulse, which typically requires high computational complexity, i.e., a compression filter with a few hundred coefficients. In this paper, we propose an efficient pulse compression method of chirp-coded excitation, in which the pulse compression is conducted with complex baseband data after downsampling, to lower the computational complexity. In the proposed method, although compression is conducted with the complex data, the L-fold downsampling is applied for reducing both data rates and the number of compression filter coefficients; thus, total computational complexity is reduced to the order of 1/L(2). The proposed method was evaluated with simulation and phantom experiments. From the simulation and experiment results, the proposed pulse compression method produced similar axial resolution compared with the conventional pulse compression method with negligible errors, i.e., ≫36 dB in signal-to-error ratio (SER). These results indicate that the proposed method can maintain the performance of pulse compression of chirp-coded excitation while substantially reducing computational complexity.

  3. Ultrasound

    MedlinePlus

    Ultrasound is a type of imaging. It uses high-frequency sound waves to look at organs and ... liver, and other organs. During pregnancy, doctors use ultrasound to view the fetus. Unlike x-rays, ultrasound ...

  4. A simulation model for predicting the temperature during the application of MR-guided focused ultrasound for stroke treatment using pulsed ultrasound

    NASA Astrophysics Data System (ADS)

    Hadjisavvas, V.; Damianou, C.

    2011-09-01

    In this paper a simulation model for predicting the temperature during the application of MR-guided focused ultrasound for stroke treatment using pulsed ultrasound is presented. A single element spherically focused transducer of 5 cm diameter, focusing at 10 cm and operating at either 0.5 MHz or 1 MHz was considered. The power field was estimated using the KZK model. The temperature was estimated using the bioheat equation. The goal was to extract the acoustic parameters (power, pulse duration, duty factor and pulse repetition frequency) that maintain a temperature increase of less than 1 °C during the application of a pulse ultrasound protocol. It was found that the temperature change increases linearly with duty factor. The higher the power, the lower the duty factor needed to keep the temperature change to the safe limit of 1 °C. The higher the frequency the lower the duty factor needed to keep the temperature change to the safe limit of 1 °C. Finally, the deeper the target, the higher the duty factor needed to keep the temperature change to the safe limit of 1 °C. The simulation model was tested in brain tissue during the application of pulse ultrasound and the measured temperature was in close agreement with the simulated temperature. This simulation model is considered to be very useful tool for providing acoustic parameters (frequency, power, duty factor, pulse repetition frequency) during the application of pulsed ultrasound at various depths in tissue so that a safe temperature is maintained during the treatment. This model could be tested soon during stroke clinical trials.

  5. Effects of Pulsed Ultrasound Therapy on Sensory Nerve Conduction Parameters and the Pain Threshold Perceptions in Humans.

    PubMed

    Schuhfried, Othmar; Vukanovic, Damir; Kollmann, Christian; Pieber, Karin; Paternostro-Sluga, Tatjana

    2017-08-01

    Therapeutic ultrasound is an often-used clinical modality in the nonsurgical treatment of entrapment neuropathies. To date, the possible mechanism of action of pulsed ultrasound therapy on the peripheral nerve in the treatment of entrapment neuropathies is unclear. To examine the effects of pulsed ultrasound therapy on peripheral nerve conduction parameters. A prospective, randomized, single blind, crossover study. Outpatient clinic of a university department of physical medicine and rehabilitation. Twelve healthy volunteers between 22 and 38 years of age (8 male, 4 female). Each patient (blinded) received ultrasound therapy (1W/cm(2), pulsed: 1:5; over the course of the superficial branch of the radial nerve of the nondominant arm) and placebo (intensity: zero). The interval between the individual interventions was 1 week. The sensory nerve conduction velocity, sensory nerve action potential, supramaximal stimulation intensity of the sensory fibers of the radial nerve, and the pressure pain threshold in the sensory area of the radial nerve before and after an ultrasound-therapy and placebo intervention. To compare the results of the intervention with placebo, a paired-samples t test was applied. Compared with placebo, a significant increase after pulsed ultrasound therapy was found for the supramaximal stimulation intensity (P = .02). For the other primary outcome parameters, a significant difference was not found. The immediate effect of pulsed ultrasound therapy on a sensory nerve is minimal. Therefore, the previously reported benefit of pulsed ultrasound therapy in entrapment neuropathies might be not due to its effect on the sensory nerve. I. Copyright © 2017 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  6. Monitoring of transient cavitation induced by ultrasound and intense pulsed light in presence of gold nanoparticles.

    PubMed

    Sazgarnia, Ameneh; Shanei, Ahmad; Shanei, Mohammad Mahdi

    2014-01-01

    One of the most important challenges in medical treatment is invention of a minimally invasive approach in order to induce lethal damages to cancer cells. Application of high intensity focused ultrasound can be beneficial to achieve this goal via the cavitation process. Existence of the particles and vapor in a liquid decreases the ultrasonic intensity threshold required for cavitation onset. In this study, synergism of intense pulsed light (IPL) and gold nanoparticles (GNPs) has been investigated as a means of providing nucleation sites for acoustic cavitation. Several approaches have been reported with the aim of cavitation monitoring. We conducted the experiments on the basis of sonochemiluminescence (SCL) and chemical dosimetric methods. The acoustic cavitation activity was investigated by determining the integrated SCL signal acquired over polyacrylamide gel phantoms containing luminol in the presence and absence of GNPs in the wavelength range of 400-500 nm using a spectrometer equipped with cooled charged coupled devices (CCD) during irradiation by different intensities of 1 MHz ultrasound and IPL pulses. In order to confirm these results, the terephthalic acid chemical dosimeter was utilized as well. The SCL signal recorded in the gel phantoms containing GNPs at different intensities of ultrasound in the presence of intense pulsed light was higher than the gel phantoms without GNPs. These results have been confirmed by the obtained data from the chemical dosimetry method. Acoustic cavitation in the presence of GNPs and intense pulsed light has been suggested as a new approach designed for decreasing threshold intensity of acoustic cavitation and improving targeted therapeutic effects.

  7. Correlation of Hemorrhage Near Developing Opossum Skull With Pulsed Ultrasound Exposure Parameters.

    PubMed

    Kumar, Viksit; Bigelow, Timothy A; Mullin, Kathleen; Sakaguchi, Donald S

    2015-08-01

    High-intensity focused ultrasound (HIFU) has been used noninvasively for therapeutic applications. Before HIFU can be used therapeutically on a human fetus, the bioeffects related to HIFU must be studied, and the mechanism causing the bioeffects should be understood. Previous studies have shown that HIFU, when targeted on fetal rat and mice bones. resulted in hemorrhage. However, the mechanism responsible has not been identified. In this study, we looked at ultrasound parameters related to hemorrhage in an effort to better understand the mechanism. Brazilian opossum pups (7-8 postnatal days) were exposed to a 1.1-MHz f/1 spherically focused transducer (6.3 cm focal length). Four treatment groups of n = 14 and a control group of n = 14 were exposed to rarefactional pressures of 3.6 to 6 MPa with spatial-peak temporal average intensity values of 5.4 to 10.8 W/cm(2). The pulse repetition frequency was varied from 500 to 1000 Hz with exposure durations of 1 to 4 minutes. Four groups with sample sizes of 14 had hemorrhage percentages of 43%, 36%, 29%, and 36%, respectively. Hemorrhage occurrence and size were found to correlate strongly with the nonlinear product of energy density and number of pulses, with correlation values of 0.92 and 0.97, respectively. The dependence of hemorrhage on energy density and the number of pulses suggests that the hemorrhage may be due to high-stress, low-cycle mechanical fatigue damage. Hence, for therapeutic applications, the product of energy density and number of pulses should not exceed a certain predetermined limit. © 2015 by the American Institute of Ultrasound in Medicine.

  8. Ultrasound generation through a fiber optic delivery system using pulsed laser energy

    SciTech Connect

    Carlson, N.M.; Johnson, J.A.

    1990-01-01

    Short duration laser pulses can generate high frequency, broadband ultrasound in a material without contacting the surface. For these noncontacting techniques to be useful on the shop floor, in remote applications, and in harsh environments, a dependable delivery system must be developed. Fiber optic techniques have been used to deliver either moderate laser energy for a large number of pulses or a large laser energy for a few pulses for the purpose of generating acoustic waves. However, transmitting high energy pulses continuously through a fiber is required for practical sensing systems. Fiber optics systems are currently used for a long duration pulses (of the order of milliseconds) in laser welding applications; e.g. a welding systems developed for manufacture of headlamps uses a fiber optic delivery system. The key to the success of this welding systems is the coupling technique used to deliver laser power to the fiber. Because the pulse duration is on the order of several milliseconds, the power density in the fiber is several orders of magnitude below the power densities required for ultrasonic applications. 17 refs., 2 figs.

  9. In vivo Pulsed Magneto-motive Ultrasound Imaging Using High-performance Magnetoactive Contrast Nanoagents

    PubMed Central

    Mehrmohammadi, Mohammad; Shin, Tae-Hyun; Qu, Min; Kruizinga, Pieter; Truby, Ryan L.; Lee, Jae-Hyun

    2014-01-01

    Previously, pulsed magneto-motive ultrasound (pMMUS) imaging has been introduced as a contrast-agent-assisted ultrasound-based imaging modality capable of visualizing biological events at the cellular and molecular level. In pMMUS imaging, a high intensity pulsed magnetic field is used to excite cells or tissue labeled with magnetic nanoparticles. Then, ultrasound (US) imaging is used to monitor the mechanical response of the tissue to an externally applied magnetic field (i.e., tissue displacement). Signal to noise ratio (SNR) in pMMUS imaging can be improved by using superparamagnetic nanoparticles with larger saturation magnetization. Metal-doped magnetic nanoparticles with enhanced tunable nanomagnetism are suitable candidates to improve the SNR and, therefore, sensitivity of pMMUS imaging, which is essential for in vivo pMMUS imaging. In this study, we demonstrate the capability of pMMUS imaging to identify the presence and distribution of zinc-doped iron oxide nanoparticles in live nude mice bearing A431 (human epithelial carcinoma) xenograft tumors. PMID:24080913

  10. Simulation of diagnostic ultrasound image pulse sequences in cavitation bioeffects research.

    PubMed

    Miller, Douglas L; Dou, Chunyan; Wiggins, Roger C

    2007-10-01

    Research on cavitational bioeffects of diagnostic ultrasound (DUS) typically involves a diagnostic scanner as the exposure source. However, this can limit the ranges of exposure parameters for experimentation. Anesthetized hairless rats were mounted in a water bath and their right kidneys were exposed to ultrasound. Amplitude modulation with Gaussian envelopes simulated the image pulse sequences (IPSs) produced by diagnostic scanning. A 10 mulkgmin IV dose of Definity((R)) contrast agent was given during 1-5 min exposures. Glomerular capillary hemorrhage was assessed by histology. A stationary exposure approximated the bioeffects induced by DUS within the beam area. However, the use of five closely spaced exposures more faithfully reproduced the total effect produced within a DUS scan plane. Single pulses delivered at 1 s intervals induced the same effect as the simulated DUS. Use of 100 ms triangle-wave modulations for ramp-up or ramp-down of the IPS gave no effect or a large effect, respectively. Finally, an air-backed transducer simulating DUS without contrast agent showed a zero effect even operating at twice the present DUS guideline upper limit. Relatively simple single-element laboratory exposure systems can simulate diagnostic ultrasound exposure and allow exploration of parameter ranges beyond those available on present clinical systems.

  11. Biodiesel production from soybean oil deodorizer distillate enhanced by counter-current pulsed ultrasound.

    PubMed

    Yin, Xiulian; You, Qinghong; Ma, Haile; Dai, Chunhua; Zhang, Henan; Li, Kexin; Li, Yunliang

    2015-03-01

    Biodiesel production from soybean oil deodorizer distillate enhanced by counter-current pulsed ultrasound was studied. Effect of static probe ultrasonic enhanced transesterification (SPUE) and counter-current probe ultrasonic enhanced transesterification (CCPUE) on the biodiesel conversion were compared. The results indicated that CCPUE was a better method for enhancing transesterification. The working conditions of CCPUE were studied by single-factor experiment design and the results showed that the optimal conditions were: initial temperature 25 °C, methanol to triglyceride molar ratio 10:1, flow rate 200 mL/min, catalyst content 1.8%, ultrasound working on-time 4 s, off-time 2 s, total working time 50 min. Under these conditions, the average biodiesel conversion of three experiments was 96.1%. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Ultrasound-guided Pulsed Radiofrequency Lesioning of the Phrenic Nerve in a Patient with Intractable Hiccup

    PubMed Central

    Kang, Keum Nae; Park, In Kyung; Suh, Jeong Hun; Leem, Jeong Gill

    2010-01-01

    Persistent and intractable hiccups (with respective durations of more than 48 hours and 1 month) can result in depression, fatigue, impaired sleep, dehydration, weight loss, malnutrition, and aspiration syndromes. The conventional treatments for hiccups are either non-pharmacological, pharmacological or a nerve block treatment. Pulsed radiofrequency lesioning (PRFL) has been proposed for the modulation of the excited nervous system pathway of pain as a safe and nondestructive treatment method. As placement of the electrode in close proximity to the targeted nerve is very important for the success of PRFL, ultrasound appears to be well suited for this technique. A 74-year-old man suffering from intractable hiccups that had developed after a coronary artery bypass graft and had continued for 7 years was referred to our pain clinic. He had not been treated with conventional methods or medications. We performed PRFL of the phrenic nerve guided by ultrasound and the hiccups disappeared. PMID:20830266

  13. Photoacoustic and ultrasound imaging using dual contrast perfluorocarbon nanodroplets triggered by laser pulses at 1064 nm.

    PubMed

    Hannah, Alexander S; VanderLaan, Donald; Chen, Yun-Sheng; Emelianov, Stanislav Y

    2014-09-01

    Recently, a dual photoacoustic and ultrasound contrast agent-named photoacoustic nanodroplet-has been introduced. Photoacoustic nanodroplets consist of a perfluorocarbon core, surfactant shell, and encapsulated photoabsorber. Upon pulsed laser irradiation the perfluorocarbon converts to gas, inducing a photoacoustic signal from vaporization and subsequent ultrasound contrast from the resulting gas microbubbles. In this work we synthesize nanodroplets which encapsulate gold nanorods with a peak absorption near 1064 nm. Such nanodroplets are optimal for extended photoacoustic imaging depth and contrast, safety and system cost. We characterized the nanodroplets for optical absorption, image contrast and vaporization threshold. We then imaged the particles in an ex vivo porcine tissue sample, reporting contrast enhancement in a biological environment. These 1064 nm triggerable photoacoustic nanodroplets are a robust biomedical tool to enhance image contrast at clinically relevant depths.

  14. Doppler ultrasound in the measurement of pulse wave velocity: agreement with the Complior method

    PubMed Central

    2011-01-01

    Aortic stiffness is an independent predictor factor for cardiovascular risk. Different methods for determining pulse wave velocity (PWV) are used, among which the most common are mechanical methods such as SphygmoCor or Complior, which require specific devices and are limited by technical difficulty in obtaining measurements. Doppler guided by 2D ultrasound is a good alternative to these methods. We studied 40 patients (29 male, aged 21 to 82 years) comparing the Complior method with Doppler. Agreement of both devices was high (R = 0.91, 0.84-0.95, 95% CI). The reproducibility analysis revealed no intra-nor interobserver differences. Based on these results, we conclude that Doppler ultrasound is a reliable and reproducible alternative to other established methods for the measurement of aortic PWV. PMID:21496271

  15. Cancer treatment using an optically inert Rose Bengal derivative combined with pulsed focused ultrasound

    NASA Astrophysics Data System (ADS)

    Kim, Yoo-Shin; Rubio, Valentina; Qi, Jianjun; Xia, Rongmin; Shi, Zheng-Zheng; Peterson, Leif; Tung, Ching-Hsuan; O'Neill, Brian E.

    2012-10-01

    Pulsed high intensity focused ultrasound (HIFU) produced has been combined with a photo-insensitive Rose Bengal derivative (RB2) to provide a synergistic cytotoxicity requiring the presence of both ultrasonic cavitation and drug. In vitro tests have shown that a short treatment (less than 30 s) of pulsed HIFU with peak negative pressure >7 MPa (˜27 W acoustic power at 1.4 MHz) destroys >95 % of breast cancer cells MDA-MB-231 in suspension with >10 μM of the compound. Neither the pulsed HIFU nor the RB2 compound was found to have any significant impact on the viability of the cells when used alone. Introducing an antioxidant (Nacetylcysteine) reduced the effectiveness of the treatment. In vivo tests using these same cells growing as a xenograft in nu/nu mice were also done. An ultrasound contrast agent (Optison) and lower frequency (1.0 MHz) was used to help initiate cavitation at the tumor site. We were able to demonstrate tumor regression with cavitation alone, however, addition of RB2 compound injected i.v. yielded a substantial synergistic improvement over either cavitation or RB2 injection alone.

  16. Pulsed laser generation of ultrasound in a metal plate between the melting and ablation thresholds

    SciTech Connect

    Every, A. G.; Utegulov, Z. N.; Veres, I. A.

    2015-03-31

    The generation of ultrasound in a metal plate exposed to nanosecond pulsed laser heating, sufficient to cause melting but not ablation, is treated. Consideration is given to the spatial and temporal profiles of the laser pulse, penetration of the laser beam into the sample, the evolution of the melt pool, and thermal conduction in the melt and surrounding solid. The excitation of the ultrasound takes place over a few nanoseconds, and occurs predominantly within the thermal diffusion length of a micron or so beneath the surface. Because of this, the output of the thermal simulations can be represented as axially symmetric transient radial and normal surface force distributions. The epicentral displacement response at the opposite surface to these forces is obtained by two methods, the one based on the elastodynamic Green’s functions for plate geometry determined by the Cagniard generalized ray method, and the other using a finite element numerical method. The two approaches are in very close agreement. Numerical simulations are reported of the epicentral displacement response of a 3.12mm thick tungsten plate irradiated with a 4 ns pulsed laser beam with Gaussian spatial profile, at intensities below and above the melt threshold. Comparison is made between results obtained using available temperature dependent thermophysical data, and room temperature materials constants except near the melting point.

  17. Effect of frequency characteristic of excitation pulse on lateral spatial resolution in coded ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Fujita, Hiroki; Hasegawa, Hideyuki

    2017-07-01

    Recently, portable ultrasonic diagnostic equipment has frequently been used in clinical situations. The use of portable ultrasonic diagnostic equipment expands various diagnosis areas, such as remote medical diagnosis, and emergent diagnosis at disaster. It is expected that portable ultrasonic diagnostic equipment will be used more frequently in the future. To make ultrasonic diagnostic equipment portable, the number of transducer elements in an ultrasonic probe should be reduced significantly. Therefore, the transmit-receive sensitivity of the ultrasonic probe is degraded. For the improvement of the signal-to-noise ratio (SNR) of the received ultrasonic echo, coded excitation was introduced in ultrasonic imaging. Owing to pulse compression applied to the received echo signal, its SNR significantly improved without the degradation of the range spatial resolution. However, the lateral spatial resolution in coded ultrasound imaging has not been investigated in previous studies. The present study showed that the lateral resolution in coded ultrasound imaging using a typical code, 5-bit Barker code, was worse than that using a conventional short pulse. Such degradation was discussed in terms of the frequency characteristics of the impulse response of the ultrasonic transducer and the excitation pulse. Also, the Gaussian phase coherence factor was introduced as one of the methods to overcome such degradation in lateral spatial resolution.

  18. Investigations into pulsed-high intensity focused ultrasound enhanced delivery: Preliminary evidence for a novel mechanism

    PubMed Central

    Hancock, Hilary A.; Smith, Lauren H.; Cuesta, Julian; Durrani, Amir K.; Angstadt, Mary; Palmeri, Mark L.; Kimmel, Eitan; Frenkel, Victor

    2009-01-01

    Pulsed-high intensity focused ultrasound (HIFU) exposures without ultrasound contrast agents have been used for non-invasively enhancing the delivery of various agents to improve their therapeutic efficacy in a variety of tissue models in a non-destructive manner. Despite the versatility of these exposures, little is known about the mechanisms by which their effects are produced. In this study pulsed-HIFU exposures were given in the flank muscle of mice, followed by the administration a variety of fluorophores, both soluble and particulate, by local or systemic injection. In vivo imaging (whole animal and microscopic) was used to quantify observations of increased extravasation and interstitial transport of the fluorophores as a result of the exposures. Histological analysis indicated that the exposures caused some structural alterations such as enlarged gaps between muscle fibers. These effects were consistent with increasing the permeability of the tissues; however they were found to be transient and reversed themselves gradually within 72 hrs. Simulations of radiation force induced displacements and the resulting local shear strain they produced were carried out to potentially explain the manner by which these effects occurred. A better understanding of the mechanisms involved with pulsed-HIFU exposures for non-invasively enhancing delivery will facilitate the process for optimizing their use. PMID:19616368

  19. Non-Invasive Thrombolysis Using Pulsed Ultrasound Cavitation Therapy – Histotripsy

    PubMed Central

    Maxwell, Adam D.; Cain, Charles A.; Duryea, Alexander P.; Yuan, Lingqian; Gurm, Hitinder S.; Xu, Zhen

    2009-01-01

    Clinically available thrombolysis techniques are limited by either slow reperfusion (drugs) or invasiveness (catheters), and carry significant risks of bleeding. In this study, the feasibility of using histotripsy as an efficient and non-invasive thrombolysis technique was investigated. Histotripsy fractionates soft tissue through controlled cavitation using focused, short, high-intensity ultrasound pulses. In-vitro blood clots formed from fresh canine blood were treated by histotripsy. The treatment was applied using a focused 1-MHz transducer, with 5-cycle pulses at a pulse repetition rate of 1 kHz. Acoustic pressures varying from 2 – 12 MPa peak negative pressure were tested. Our results show that histotripsy can perform effective thrombolysis with ultrasound energy alone. Histotripsy thrombolysis only occurred at peak negative pressure ≥6 MPa when initiation of a cavitating bubble cloud was detected using acoustic backscatter monitoring. Blood clots weighing 330 mg were completely broken down by histotripsy in 1.5 – 5 minutes. The clot was fractionated to debris with >96% weight smaller than 5 μm diameter. Histotripsy thrombolysis treatment remained effective under a fast, pulsating flow (a circulatory model) as well as in static saline. Additionally, we observed that fluid flow generated by a cavitation cloud can attract, trap, and further break down clot fragments. This phenomenon may provide a non-invasive method to filter and eliminate hazardous emboli during thrombolysis. PMID:19854563

  20. Imaging monitored loosening of dense fibrous tissues using high-intensity pulsed ultrasound

    NASA Astrophysics Data System (ADS)

    Yeh, Chia-Lun; Li, Pai-Chi; Shih, Wen-Pin; Huang, Pei-Shin; Kuo, Po-Ling

    2013-10-01

    Pulsed high-intensity focused ultrasound (HIFU) is proposed as a new alternative treatment for contracture of dense fibrous tissue. It is hypothesized that the pulsed-HIFU can release the contracted tissues by attenuating tensile stiffness along the fiber axis, and that the stiffness reduction can be quantitatively monitored by change of B-mode images. Fresh porcine tendons and ligaments were adapted to an ex vivo model and insonated with pulsed-HIFU for durations ranging from 5 to 30 min. The pulse length was 91 µs with a repetition frequency of 500 Hz, and the peak rarefactional pressure was 6.36 MPa. The corresponding average intensities were kept around 1606 W cm-2 for ISPPA and 72.3 W cm-2 for ISPTA. B-mode images of the tissues were acquired before and after pulsed-HIFU exposure, and the changes in speckle intensity and organization were analyzed. The tensile stiffness of the HIFU-exposed tissues along the longitudinal axis was examined using a stretching machine. Histology examinations were performed by optical and transmission electron microscopy. Pulsed-HIFU exposure significantly decreased the tensile stiffness of the ligaments and tendons. The intensity and organization of tissue speckles in the exposed region were also decreased. The speckle changes correlated well with the degree of stiffness alteration. Histology examinations revealed that pulsed-HIFU exposure probably damages tissues via a cavitation-mediated mechanism. Our results suggest that pulsed-HIFU with a low duty factor is a promising tool for developing new treatment strategies for orthopedic disorders.

  1. Mechanical bioeffects of pulsed high intensity focused ultrasound on a simple neural model.

    PubMed

    Wahab, Radia Abdul; Choi, Mina; Liu, Yunbo; Krauthamer, Victor; Zderic, Vesna; Myers, Matthew R

    2012-07-01

    To study how pressure pulses affect nerves through mechanisms that are neither thermal nor cavitational, and investigate how the effects are related to cumulative radiation-force impulse (CRFI). Applications include traumatic brain injury and acoustic neuromodulation. A simple neural model consisting of the giant axon of a live earthworm was exposed to trains of pressure pulses produced by an 825 kHz focused ultrasound transducer. The peak negative pressure of the pulses and duty cycle of the pulse train were controlled so that neither cavitation nor significant temperature rise occurred. The amplitude and conduction velocity of action-potentials triggered in the worm were measured as the magnitude of the pulses and number of pulses in the pulse trains were varied. The functionality of the axons decreased when sufficient pulse energy was applied. The level of CRFI at which the observed effects occur is consistent with the lower levels of injury observed in this study relative to blast tubes. The relevant CRFI values are also comparable to CRFI values in other studies showing measureable changes in action-potential amplitudes and velocities. Plotting the measured action-potential amplitudes and conduction velocities from different experiments with widely varying exposure regimens against the single parameter of CRFI yielded values that agreed within 21% in terms of amplitude and 5% in velocity. A predictive model based on the assumption that the temporal rate of decay of action-potential amplitude and velocity is linearly proportional the radiation force experienced by the axon predicted the experimental amplitudes and conduction velocities to within about 20% agreement. The functionality of axons decreased due to noncavitational mechanical effects. The radiation force, possibly by inducing changes in ion-channel permeability, appears to be a possible mechanism for explaining the observed degradation. The CRFI is also a promising parameter for quantifying neural

  2. Mechanical bioeffects of pulsed high intensity focused ultrasound on a simple neural model.

    PubMed

    Wahab, Radia Abdul; Choi, Mina; Liu, Yunbo; Krauthamer, Victor; Zderic, Vesna; Myers, Matthew R

    2012-07-01

    To study how pressure pulses affect nerves through mechanisms that are neither thermal nor cavitational, and investigate how the effects are related to cumulative radiation-force impulse (CRFI). Applications include traumatic brain injury and acoustic neuromodulation. A simple neural model consisting of the giant axon of a live earthworm was exposed to trains of pressure pulses produced by an 825 kHz focused ultrasound transducer. The peak negative pressure of the pulses and duty cycle of the pulse train were controlled so that neither cavitation nor significant temperature rise occurred. The amplitude and conduction velocity of action-potentials triggered in the worm were measured as the magnitude of the pulses and number of pulses in the pulse trains were varied. The functionality of the axons decreased when sufficient pulse energy was applied. The level of CRFI at which the observed effects occur is consistent with the lower levels of injury observed in this study relative to blast tubes. The relevant CRFI values are also comparable to CRFI values in other studies showing measureable changes in action-potential amplitudes and velocities. Plotting the measured action-potential amplitudes and conduction velocities from different experiments with widely varying exposure regimens against the single parameter of CRFI yielded values that agreed within 21% in terms of amplitude and 5% in velocity. A predictive model based on the assumption that the temporal rate of decay of action-potential amplitude and velocity is linearly proportional the radiation force experienced by the axon predicted the experimental amplitudes and conduction velocities to within about 20% agreement. The functionality of axons decreased due to noncavitational mechanical effects. The radiation force, possibly by inducing changes in ion-channel permeability, appears to be a possible mechanism for explaining the observed degradation. The CRFI is also a promising parameter for quantifying neural

  3. Evaluation of pulsed high intensity focused ultrasound exposures on metastasis in a murine model

    PubMed Central

    Hancock, Hilary; Dreher, Matthew R.; Crawford, Nigel; Pollock, Claire B.; Shih, Jennifer; Wood, Bradford J.; Hunter, Kent; Frenkel, Victor

    2014-01-01

    High intensity focused ultrasound (HIFU) may be employed in two ways: continuous exposures for thermal ablation of tissue (>60°C), and pulsed-exposures for non-ablative effects, including low temperature hyperthermia (37–45°C), and non thermal effects (e.g. acoustic cavitation and radiation forces). Pulsed-HIFU effects may enhance the tissue's permeability for improved delivery of drugs and genes, for example, by opening up gaps between cells in the vasculature and parenchyma. Inducing these effects may improve local targeting of therapeutic agents, however; concerns exist that pulsed exposures could theoretically also facilitate dissemination of tumor cells and exacerbate metastases. In the present study, the influence of pulsed-HIFU exposures on increasing metastatic burden was evaluated in a murine model with metastatic breast cancer. A preliminary study was carried out to validate the model and determine optimal timing for treatment and growth of lung metastases. Next, the effect of pulsed-HIFU on the metastatic burden was evaluated using quantitative image processing of whole-lung histological sections. Compared to untreated controls (2/15), a greater number of mice treated with pulsed-HIFU were found to have lungs “overgrown” with metastases (7/15), where individual metastases grew together such that they could not accurately be counted. Furthermore, area fraction of lung metastases (area of metastases/area of lungs) was ~30% greater in mice treated with pulsed-HIFU; however, these differences were not statistically significant. The present study details the development of an animal model for investigating the influence of interventional techniques or exposures (such as pulsed HIFU) on metastatic burden. PMID:19517258

  4. A new method for evaluating the degeneration of articular cartilage using pulse-echo ultrasound.

    PubMed

    Sun, Anyu; Bai, Xiaolong; Ju, Bing-Feng

    2015-03-01

    This paper presents a novel nondestructive ultrasonic technique for measuring the sound speed and acoustic impedance of articular cartilage using the pulsed Vz,t technique. Vz,t data include a series of pulsed ultrasonic echoes collected using different distances between the ultrasonic transducer and the specimen. The 2D Fourier transform is applied to the Vz,t data to reconstruct the 2D reflection spectrum Rθ,ω. To obtain the reflection coefficient of articular cartilage, the Vz,t data from a reference specimen with a well-known reflection coefficient are obtained to eliminate the dependence on the general system transfer function. The ultrasound-derived aggregate modulus (Ha) is computed based on the measured reflection coefficient and the sound speed. In the experiment, 32 cartilage-bone samples were prepared from bovine articular cartilage, and 16 samples were digested using 0.25% trypsin solution. The sound speed and Ha of these cartilage samples were evaluated before and after degeneration. The magnitude of the sound speed decreased with trypsin digestion (from 1663 ± 5.6 m/s to 1613 ± 5.3 m/s). Moreover, the Young's modulus in the corresponding degenerative state was measured and was correlated with the ultrasound-derived aggregate modulus. The ultrasound-derived aggregate modulus was determined to be highly correlated with the Young's modulus (n = 16, r>0.895, p<0.003, Pearson correlation test for each measurement). The results demonstrate the effectiveness of using the proposed method to assess the changes in sound speed and the ultrasound-derived aggregate modulus of cartilage after degeneration.

  5. Pulsed Focused Ultrasound Induced Displacements in Confined In Vitro Blood Clots

    PubMed Central

    Wright, Cameron C.; Hynynen, Kullervo; Goertz, David E.

    2015-01-01

    Ultrasound has been shown to potentiate the effects of tissue plasminogen activator (tPA) to improve clot lysis in a range of in vitro and in vivo studies as well as in clinical trials. One possible mechanism of action is acoustic radiation force induced clot displacements. In this study we investigate the temporal and spatial dynamics of clot displacements and strain initiated by focused ultrasound pulses. Displacements were produced by a 1.51 MHz f-number 1 transducer over a range of acoustic powers (1–85 W) in clots constrained within an agar vessel phantom channel. Displacements were tracked during and after a 5.45 ms therapy pulse using a 20 MHz high frequency ultrasound imaging probe. Peak thrombus displacements were found to be linear as a function of acoustic power up to 60 W before leveling off near 128 μm for the highest transmit powers. The time to peak displacement and recovery time of blood clots were largely independent of acoustic powers with measured values near 2 ms. A linear relationship between peak axial strain and transmit power was observed, reaching a peak value of 11% at 35 W. The peak strain occurred ~0.75 mm from the focal zone for all powers investigated in both lateral and axial directions. These results indicate that substantial displacements can be induced by focused ultrasound in confined blood clots, and that the spatial and temporal displacement patterns are complex and highly dependant on exposure conditions, which has implications for future work investigating their link to clot lysis and for developing approaches to exploit these effects. PMID:22194235

  6. Pulse-echo ultrasound transit time spectroscopy: A comparison of experimental measurement and simulation prediction.

    PubMed

    Wille, Marie-Luise; Almualimi, Majdi A; Langton, Christian M

    2016-01-01

    Considering ultrasound propagation through complex composite media as an array of parallel sonic rays, a comparison of computer-simulated prediction with experimental data has previously been reported for transmission mode (where one transducer serves as transmitter, the other as receiver) in a series of 10 acrylic step-wedge samples, immersed in water, exhibiting varying degrees of transit time inhomogeneity. In this study, the same samples were used but in pulse-echo mode, where the same ultrasound transducer served as both transmitter and receiver, detecting both 'primary' (internal sample interface) and 'secondary' (external sample interface) echoes. A transit time spectrum was derived, describing the proportion of sonic rays with a particular transit time. A computer simulation was performed to predict the transit time and amplitude of various echoes created, and compared with experimental data. Applying an amplitude-tolerance analysis, 91.7% ± 3.7% of the simulated data were within ±1 standard deviation of the experimentally measured amplitude-time data. Correlation of predicted and experimental transit time spectra provided coefficients of determination (R(2)%) ranging from 100.0% to 96.8% for the various samples tested. The results acquired from this study provide good evidence for the concept of parallel sonic rays. Furthermore, deconvolution of experimental input and output signals has been shown to provide an effective method to identify echoes otherwise lost due to phase cancellation. Potential applications of pulse-echo ultrasound transit time spectroscopy include improvement of ultrasound image fidelity by improving spatial resolution and reducing phase interference artefacts.

  7. A new method for evaluating the degeneration of articular cartilage using pulse-echo ultrasound

    NASA Astrophysics Data System (ADS)

    Sun, Anyu; Bai, Xiaolong; Ju, Bing-Feng

    2015-03-01

    This paper presents a novel nondestructive ultrasonic technique for measuring the sound speed and acoustic impedance of articular cartilage using the pulsed V(z,t) technique. V(z,t) data include a series of pulsed ultrasonic echoes collected using different distances between the ultrasonic transducer and the specimen. The 2D Fourier transform is applied to the V(z,t) data to reconstruct the 2D reflection spectrum R(θ,ω). To obtain the reflection coefficient of articular cartilage, the V(z,t) data from a reference specimen with a well-known reflection coefficient are obtained to eliminate the dependence on the general system transfer function. The ultrasound-derived aggregate modulus (Ha) is computed based on the measured reflection coefficient and the sound speed. In the experiment, 32 cartilage-bone samples were prepared from bovine articular cartilage, and 16 samples were digested using 0.25% trypsin solution. The sound speed and Ha of these cartilage samples were evaluated before and after degeneration. The magnitude of the sound speed decreased with trypsin digestion (from 1663 ± 5.6 m/s to 1613 ± 5.3 m/s). Moreover, the Young's modulus in the corresponding degenerative state was measured and was correlated with the ultrasound-derived aggregate modulus. The ultrasound-derived aggregate modulus was determined to be highly correlated with the Young's modulus (n = 16, r>0.895, p<0.003, Pearson correlation test for each measurement). The results demonstrate the effectiveness of using the proposed method to assess the changes in sound speed and the ultrasound-derived aggregate modulus of cartilage after degeneration.

  8. Heat Distribution in the Lower Leg from Pulsed Short-Wave Diathermy and Ultrasound Treatments

    PubMed Central

    Garrett, Candi L.; Draper, David O.; Knight, Kenneth L.

    2000-01-01

    Objective: To compare tissue temperature rise and decay after 20-minute diathermy and ultrasound treatments. Design and Setting: We inserted 3 26-gauge thermistor microprobes into the medial aspect of the anesthetized triceps surae muscle at a depth of 3 cm and spaced 5 cm apart. Eight subjects received the diathermy treatment first, followed by the ultrasound treatment. This sequence was reversed for the remaining 8 subjects. The diathermy was applied at a frequency of 27.12 MHz at the following settings: 800 bursts per second, 400-microsecond burst duration, 850-microsecond interburst interval, peak root mean square amplitude of 150 W per burst, and an average root mean square output of 48 W per burst. The ultrasound was delivered at a frequency of 1 MHz and an intensity of 1.5 W/cm2 in the continuous mode for 20 minutes over an area of 40 times the effective radiating area. The study was performed in a ventilated research laboratory. Subjects: Sixteen (11 men, 5 women) healthy subjects (mean age = 23.56 ± 4.73 years) volunteered to participate in this study. Measurements: We recorded baseline, final, and decay temperatures for each of the 3 sites. Results: The average temperature increases over baseline temperature after pulsed short-wave diathermy were 3.02°C ± 1.02°C in site 1, 4.58°C ± 0.87°C in site 2, and 3.28°C ± 1.64°C in site 3. The average temperature increases over baseline temperature after ultrasound were only 0.17°C ± 0.40°C, 0.09°C ± 0.56°C, and -0.43°C ± 0.41°C in sites 1, 2, and 3, respectively. The temperature dropped only 1°C in 7.65 ± 4.96 minutes after pulsed short-wave diathermy. Conclusions: We conclude that pulsed short-wave diathermy was more effective than 1-MHz ultrasound in heating a large muscle mass and resulted in the muscles' retaining heat longer. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5. PMID:16558608

  9. Safety of Pulsed High Intensity Focused Ultrasound for Enhanced Drug and Gene Delivery

    NASA Astrophysics Data System (ADS)

    Kam, Anthony W.; Wang, Honghui; Farahani, Keyvan; Thomasson, David; O'Neill, Brian; Angstadt, Mary; Jesson, Johnny; Li, King C. P.

    2007-05-01

    For a limited range of exposure parameters, pulsed high intensity focused ultrasound (HIFU) has been shown to increase the delivery of certain systemically administered macromolecular diagnostic and therapeutic agents in mice. The mechanism for the enhanced delivery has not been demonstrated definitively and, in principle, can include thermal, cavitational, and non-cavitation mechanical effects. The sonicated tissue has no damage on histology. As a step towards clinical translation, the safety of this technique needs to be assessed in a clinically relevant manner. In this study, the safety of pulsed HIFU is evaluated with near real-time phase shift magnetic resonance (MR) thermometry and anatomic MR imaging using rabbits as subjects. MR guidance enables pulsed HIFU enhanced delivery to be implemented safely from a thermal standpoint. Although the effects of pulsed HIFU are not seen on anatomic MR images, they may be detected on MR sequences sensitive to permeability, diffusion, and elasticity. Such work that may optimize pulsed HIFU enhanced delivery is in progress.

  10. Ultrasound contrast imaging: influence of scatterer motion in multi-pulse techniques.

    PubMed

    Lin, Fanglue; Cachard, Christian; Mori, Riccardo; Varray, Francois; Guidi, Francesco; Basset, Olivier

    2013-10-01

    In ultrasound contrast imaging, many techniques based on multiple transmissions have been proposed to increase the contrast-to-tissue ratio (CTR). They are generally based on the response of static scatterers inside the imaged region. However, scatterer motion, for example in blood vessels, has an inevitable influence on multi-pulse techniques, which can either enhance or degrade the technique involved. This paper investigates the response of static nonlinear media insonated by multi-pulses with various phase shifts, and the influence of scatterer motion on multi-pulse techniques. Simulations and experimental results from a single bubble and clouds of bubbles show that the phase shift of the echoes backscattered from bubbles is dependent on the transmissions' phase shift, and that the bubble motion influences the efficiency of multi-pulse techniques: fundamental and second-harmonic amplitudes of the processed signal change periodically, exhibiting maximum or minimum values, according to scatterer motion. Furthermore, experimental results based on the second-harmonic inversion (SHI) technique reveal that bubble motion can be taken into account to regulate the pulse repetition frequency (PRF). With the optimal PRF, the CTR of SHI images can be improved by about 12 dB compared with second-harmonic images.

  11. Cost-effective design of a concurrent photoacoustic-ultrasound microscope using single laser pulses

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Shao; Liu, Wei-Wen; Li, Pai-Chi

    2016-03-01

    A method for concurrent photoacoustic (PA) and ultrasound (US) imaging with single laser pulses was previously demonstrated. An optical-absorbing multilayer film that can generate a US pulse based on the thermoelastic effect is used. With such a film, the generated US can be adjusted so that it does not overlap with the spectrum of the PA signal generated by the light transmitting through the layer. Thus, the US signal and the PA signal can be generated and separated by using a single laser pulse with spectral filtering. In this study, we continue with the same concurrent imaging approach and propose a cost-effective and portable design. The design consists of a pulsed laser diode with the repetition rate up to 25 kHz and energy of 2 μJ/pulse. A multilayer film is employed to generate narrow band US signals under laser excitation for US imaging. With simple spectral filtering, the PA signals and the US signals can be separated. With optical resolution, the system has a theoretical lateral resolution of 2 μm in PA imaging and 200 μm in US imaging. One of the applications of the proposed microscope is for tumor biology, where angiogenesis is an essential topic for understanding tumor growth and tumor metastasis. We will demonstrate performance of the proposed system by imaging vasculature networks.

  12. Exploring the use of Low-intensity Ultrasonics as a Tool for Assessing the Salt Content in Pork Meat Products

    NASA Astrophysics Data System (ADS)

    García-Pérez, J. V.; de Prados, M.; Martínez-Escrivá, G.; González, R.; Mulet, A.; Benedito, J.

    Meat industry demands non-destructive techniques for the control of the salting process to achieve a homogeneous final salt content in salted meat products. The feasibility of using low-intensity ultrasound for characterizing the salting process of pork meat products was evaluated. The ultrasonic velocity (V) and time of flight (TF) were measured by through-transmission and pulse-echo methods, respectively, in salted meat products. Salting involved an increase of the V in meat muscles and a decrease of the time of flight in whole hams. Measuring the V before and after salting, the salt content could be estimated. Moreover, online monitoring of the salting process by computing the TF could be considered a reliable tool for quality control purposes.

  13. An ultrasound-based method for determining pulse wave velocity in superficial arteries.

    PubMed

    Rabben, Stein Inge; Stergiopulos, Nikos; Hellevik, Leif Rune; Smiseth, Otto A; Slørdahl, Stig; Urheim, Stig; Angelsen, Bjørn

    2004-10-01

    In this paper, we present a method for estimating local pulse wave velocity (PWV) solely from ultrasound measurements: the area-flow (QA) method. With the QA method, PWV is estimated as the ratio between change in flow and change in cross-sectional area (PWV = dQ/dA) during the reflection-free period of the cardiac cycle. In four anaesthetized dogs and 21 human subjects (age 23-74) we measured the carotid flow and cross-sectional area non-invasively by ultrasound. As a reference method we used the Bramwell-Hill (BH) equation which estimates PWV from pulse pressure and cross-sectional area. Additionally, we therefore measured brachial pulse pressure by oscillometry in the human subjects, and central aortic pulse pressure by micro-manometry in the dogs. As predicted by the pressure dependency of arterial stiffness, the estimated PWV decreased when the aortic pressure was lowered in two of the dogs. For the human subjects, the QA and BH estimates were correlated (R=0.43, p<0.05) and agreed on average (mean difference of -0.14 m/s). The PWV by the BH method increased with age (p<0.01) whereas the PWV by the QA method tended to increase with age (p<0.1). This corresponded to a larger residual variance (residual = deviation of the estimated PWV from the regression line) for the QA method than for the BH method, indicating different precisions for the two methods. This study illustrates that the simple equation PWV = dQ/dA gives estimates correlated to the PWV of the reference method. However, improvements in the basic measurements seem necessary to increase the precision of the method.

  14. Ultrasound-Guided Genicular Nerve Pulsed Radiofrequency Treatment For Painful Knee Osteoarthritis: A Preliminary Report.

    PubMed

    Kesikburun, Serdar; Yaşar, Evren; Uran, Ayça; Adigüzel, Emre; Yilmaz, Bilge

    2016-07-01

    Genicular nerve ablation with radiofrequency (RF) has recently emerged as a promising treatment in the management of osteoarthritis related knee pain. To date, genicular nerve injections have been performed under fluoroscopic guidance. To evaluate the effect of ultrasound-guided genicular nerve pulsed RF treatment on chronic knee pain and function in patients with knee osteoarthritis. Single-arm prospective study. University hospital and rehabilitation center in Turkey. A review was made of 29 patients with medial knee osteoarthritis who had undergone genicular nerve block in the previous 6 months. Patients with at least 50% reduction in the visual analog scale (VAS) score after genicular nerve block and with no on-going pain relief were selected for the study. Ultrasound-guided genicular nerve pulsed RF was applied to 15 knees of 9 patients. Pain and knee function were assessed with 100-mm VAS and Western Ontario and McMaster Universities (WOMAC) index throughout 3 months. A significant reduction in VAS scores was detected over time after the pulsed RF procedure (f: 69.24, P < 0.01). There was a significant improvement in the WOMAC scores (f: 539.68 , P < 0.01). The small number of participants, the lack of a control group, and short follow-up period were limitations of the study. Genicular nerve pulsed RF treatment has been found to be safe and beneficial in osteoarthritis related knee pain. Further studies with a larger population and randomized controlled study design are warranted to confirm the positive findings of this preliminary report.

  15. Ultrasound-guided pulsed radiofrequency treatment of the cervical sympathetic chain for complex regional pain syndrome

    PubMed Central

    Kim, Eung Don; Yoo, Woo Joo; Kim, Yoo Na; Park, Hue Jung

    2017-01-01

    Abstract The stellate ganglion is a common target to manage neuropathic pain in the upper extremities. However, the effect duration of a single stellate ganglion block is often temporary. To overcome the short-term effects of a single sympathetic block, pulsed radiofrequency (PRF) can be applied. The aim of the present study was to investigate the efficacy of PRF on the cervical sympathetic chain under ultrasound guidance for complex regional pain syndrome (CRPS). Twelve CRPS patients who underwent PRF on the cervical sympathetic chain were enrolled in this retrospective analysis. Under ultrasound guidance, PRF was performed for 420 seconds at 42°C on the C6- and C7-level sympathetic chain. The pain intensity decreased significantly at 1 week after the procedure. Overall, 91.7% of patients experienced at least moderate improvement. A positive correlation was observed between the extent of pain reduction at 1 week after PRF and the degree of overall benefit (r = 0.605, P = 0.037). This reduction in symptoms was maintained for a mean of 31.41 ± 26.07 days after PRF. There were no complications associated with this procedure. PRF on the cervical sympathetic chain, which can be performed easily and safely under ultrasound guidance, should be considered an option for managing CRPS of the upper extremities. PMID:28072749

  16. Pulsed radiofrequency under ultrasound guidance for the tarsal tunnel syndrome: two case reports.

    PubMed

    Chon, Jin Young; Hahn, Yun Jin; Sung, Choon Ho; Jung, Sung Hoon; Moon, Ho Sik

    2014-12-01

    Tarsal tunnel syndrome (TTS) is a compression neuropathy that results from entrapment of the posterior tibial nerve or its branches. TTS may be treated either by conservative measures, including physical therapy, medications, and steroid injections, or by surgical decompression. Despite a variety of treatments, a few cases of TTS will relapse, and many cases of recurrent TTS will require re-operation. Pulsed radiofrequency (PRF) is known to have a number of advantages for pain management, particularly as this technique does not cause neural compromise such as motor weakness. Here, we report a new application of ultrasound-guided PRF in two cases of intractable TTS. Both patients had a long duration of severe foot pain and had been treated with various therapeutic modalities without lasting relief. We applied ultrasound-guided PRF to the affected posterior tibial nerve in each patient, and both had significantly reduced pain intensity scores and analgesic requirements without any complications. Ultrasound-guided PRF for intractable TTS relieved severe foot pain. It may supersede surgery as a reliable treatment for intractable TTS.

  17. Ultrasound-assisted pulse electrodeposition and characterization of Co-W/MWCNTs nanocomposite coatings

    NASA Astrophysics Data System (ADS)

    Su, Fenghua; Liu, Cansen; Huang, Ping

    2014-08-01

    Co-W/MWCNTs nanocomposite coatings were synthesized by pulse electrodeposition with help of ultrasound agitation. Effect of agitation techniques of electrolyte on the microstructure and morphology of the nanocomposite coatings were evaluated. The Co-W/MWCNTs composite coating produced by mechanical agitation shows rough surface and has large and poorly dispersed CNT agglomerates in its layer and surface, resulting in this coating displaying low hardness and inferior wear resistance and friction reduction. Ultrasound agitation is much better than mechanical stirring to evenly distribute MWCNTs in the layer and surface of the composite coatings. The nanocomposite coatings produced with ultrasound agitation exhibits smoother surface, higher hardness and better tribological properties than the one produced with mechanical agitation. In addition, the ultrasonic power greatly affects the morphology and properties of the as-prepared composite coatings. As the ultrasonic power of 400 W was applied, a large number of MWCNTs are successfully incorporated and evenly distributed in the as-prepared composite coating, which result in this composite coating exhibiting the highest hardness and the best friction-reducing and anti-wear ability. In general, the differences of the friction and wear behaviors and the corresponding mechanisms of these coatings produced under different conditions are attributed to their different hardness and microstructures.

  18. Pulsed focused ultrasound changes nerve conduction of earthworm giant axonal fibers.

    PubMed

    Yoo, Sarah H; Croce, Phillip; Margolin, Ryan W; Lee, Stephanie D; Lee, Wonhye

    2017-03-01

    This study examined the effects of pulsed focused ultrasound (FUS) in disrupting nerve conduction. FUS operating at a 210 kHz fundamental frequency was administered to the medial and lateral giant axonal nerve fibers of earthworms in a burst of pulses (1 ms tone burst duration, 20 Hz pulse repetition frequency). The magnitude and latencies of the nerve potentials induced by electrical stimulation were measured under three experimental conditions - (I) no sonication, (II) sonication at 600 mW/cm spatial-peak temporal-average intensity (Ispta), and (III) sonication at 200 mW/cm Ispta. The sonication at 600 mW/cm temporarily decreased the magnitude of the action potential peak (~16%), whereas the baseline peak level was quickly restored in postsonication sessions. Sonication administered at a lower intensity (i.e. 200 mW/cm) did not alter the peak magnitude. The sonication did not alter the nerve conduction velocity. The acoustic intensities used in the experiment did not increase the temperature of the sonicated tissue. The results indicate that axonal neurotransmission can be disrupted temporarily by the application of pulsed FUS, suggesting its potential utility in modulating the functional connectivity established by white matter tracts in the brain.

  19. Pulsed magneto-motive ultrasound imaging to detect intracellular trafficking of magnetic nanoparticles.

    PubMed

    Mehrmohammadi, Mohammad; Qu, Min; Ma, Li L; Romanovicz, Dwight K; Johnston, Keith P; Sokolov, Konstantin V; Emelianov, Stanislav Y

    2011-10-14

    As applications of nanoparticles in medical imaging and biomedicine rapidly expand, the interactions of nanoparticles with living cells have become an area of active interest. For example, intracellular accumulation of nanoparticles-an important part of cell-nanoparticle interaction-has been well studied using plasmonic nanoparticles and optical or optics-based techniques due to the change in optical properties of the nanoparticle aggregates. However, magnetic nanoparticles, despite their wide range of clinical applications, do not exhibit plasmonic-resonant properties and therefore their intracellular aggregation cannot be detected by optics-based imaging techniques. In this study, we investigated the feasibility of a novel imaging technique-pulsed magneto-motive ultrasound (pMMUS)-to identify intracellular accumulation of endocytosed magnetic nanoparticles. In pMMUS imaging a focused, high intensity, pulsed magnetic field is used to excite the cells labeled with magnetic nanoparticles, and ultrasound imaging is then used to monitor the mechanical response of the tissue. We demonstrated previously that clusters of magnetic nanoparticles amplify the pMMUS signal in comparison to the signal from individual nanoparticles. Here we further demonstrate that pMMUS imaging can identify interaction between magnetic nanoparticles and living cells, i.e. intracellular accumulation of nanoparticles within the cells. The results of our study suggest that pMMUS imaging can not only detect the presence of magnetic nanoparticles but also provides information about their intracellular accumulation non-invasively and in real-time.

  20. Jets from pulsed-ultrasound-induced cavitation bubbles near a rigid boundary

    NASA Astrophysics Data System (ADS)

    Brujan, Emil-Alexandru

    2017-06-01

    The dynamics of cavitation bubbles, generated from short (microsecond) pulses of ultrasound and situated near a rigid boundary, are investigated numerically. The temporal development of the bubble shape, bubble migration, formation of the liquid jet during bubble collapse, and the kinetic energy of the jet are investigated as a function of the distance between bubble and boundary. During collapse, the bubble migrates towards the boundary and the liquid jet reaches a maximum velocity between 80 m s-1 and 120 m s-1, depending on the distance between bubble and boundary. The conversion of bubble energy to kinetic energy of the jet ranges from 16% to 23%. When the bubble is situated in close proximity to the boundary, the liquid jet impacts the boundary with its maximum velocity, resulting in an impact pressure of the order of tens of MPa. The rapid expansion of the bubble, the impact of the liquid jet onto the nearby boundary material, and the high pressure developed inside the bubble at its minimum volume can all contribute to the boundary material damage. The high pressure developed during the impact of the liquid jet onto the biological material and the shearing forces acting on the material surface as a consequence of the radial flow of the jet outward from the impact site are the main damage mechanisms of rigid biological materials. The results are discussed with respect to cavitation damage of rigid biological materials, such as disintegration of renal stones and calcified tissue and collateral effects in pulsed ultrasound surgery.

  1. Formation of Single Bubbles from a Submerged Orifice Using Pulsed Ultrasound Waves

    NASA Astrophysics Data System (ADS)

    Shirota, Minori; Imamura, Tomohiro; Kameda, Masaharu

    A new experimental method is presented in which single small gas bubbles are generated in a liquid from a submerged orifice using pulsed ultrasound waves. Pulsed ultrasound waves having a frequency of 15 kHz and a maximum pressure amplitude of approximately 10 kPa are irradiated to a bubble growing from an orifice. Single air bubbles ranging from approximately 0.05 to 0.2 mm in radius are obtained in silicone oil (kinematic viscosity: 1 mm2/s) by using two orifices (0.02 and 0.04 mm in diameter) and by shifting the onset of the detachment-assistance pressure wave. The bubble deformation and detaching processes were visualized and analyzed using high-speed video imaging and direct numerical simulation. Consequently, it is revealed that the bubbles are forced to elongate upward due to the fast oscillatory flow of gas through the orifice, and the elongation causes the bubbles to detach from the orifice. The size of the bubbles at detachment is well estimated by employing a common spherical bubble formation model.

  2. MATLAB/Simulink Pulse-Echo Ultrasound System Simulator Based on Experimentally Validated Models.

    PubMed

    Kim, Taehoon; Shin, Sangmin; Lee, Hyongmin; Lee, Hyunsook; Kim, Heewon; Shin, Eunhee; Kim, Suhwan

    2016-02-01

    A flexible clinical ultrasound system must operate with different transducers, which have characteristic impulse responses and widely varying impedances. The impulse response determines the shape of the high-voltage pulse that is transmitted and the specifications of the front-end electronics that receive the echo; the impedance determines the specification of the matching network through which the transducer is connected. System-level optimization of these subsystems requires accurate modeling of pulse-echo (two-way) response, which in turn demands a unified simulation of the ultrasonics and electronics. In this paper, this is realized by combining MATLAB/Simulink models of the high-voltage transmitter, the transmission interface, the acoustic subsystem which includes wave propagation and reflection, the receiving interface, and the front-end receiver. To demonstrate the effectiveness of our simulator, the models are experimentally validated by comparing the simulation results with the measured data from a commercial ultrasound system. This simulator could be used to quickly provide system-level feedback for an optimized tuning of electronic design parameters.

  3. ULTRASOUND PULSE-ECHO IMAGING USING THE SPLIT-STEP FOURIER PROPAGATOR

    SciTech Connect

    HUANG, LIANJIE; QUAN, YOULI

    2007-01-31

    Ultrasonic reflection imaging has the potential to produce higher image resolution than transmission tomography, but imaging resolution and quality still need to be further improved for early cancer detection and diagnosis. We present an ultrasound reflection image reconstruction method using the split-step Fourier propagator. It is based on recursive inward continuation of ultrasonic wavefields in the frequency-space and frequency-wavenumber domains. The inward continuation within each extrapolation interval consists of two steps. In the first step, a phase-shift term is applied to the data in the frequency-wavenumber domain for propagation in a reference medium. The second step consists of applying another phase-shift term to data in the frequency-space domain to approximately compensate for ultrasonic scattering effects of heterogeneities within the breast. We use synthetic ultrasound pulse-echo data recorded around a ring for heterogeneous, computer-generated numerical breast phantoms to study the imaging capability of the method. The phantoms are derived from an experimental breast phantom and a sound-speed tomography image of an in-vivo ultrasound breast data collected usi ng a ring array. The heterogeneous sound-speed models used for pulse-echo imaging are obtained using a computationally efficient, first-arrival-time (time-of-flight) transmission tomography method. Our studies demonstrate that reflection image reconstruction using the split-step Fourier propagator with heterogeneous sound-speed models significantly improves image quality and resolution. We also numerically verify the spatial sampling criterion of wavefields for a ring transducer array.

  4. Thresholds for inertial cavitation in albunex suspensions under pulsed ultrasound conditions.

    PubMed

    Chang, P P; Chen, W S; Mourad, P D; Poliachik, S L; Crum, L A

    2001-01-01

    Stabilized microbubbles used as echo-contrast agents can be destroyed by ultrasonic irradiation. We have identified two pressure thresholds at which these microbubbles undergo inertial cavitation (here, defined as the collapse of gas bubbles followed by emission of an acoustic broadband noise). The first threshold (P1) corresponds to the pressure at which all the microbubbles in a cavitation field lose their property as an effective scatterer because of fragmentation or deflation. The second threshold (P2) is associated with the acoustic reactivation of the remnants of the contrast agents and is related to the onset of more violent inertial cavitation. P1 and P2 were measured as a function of the concentration of Albunex (Molecular Biosystems Inc., San Diego, CA) contrast agent, the number of transmitting acoustic cycles, and the pulse repetition frequency (PRF). The ultrasound frequency used was 1.1 MHz, and the peak negative acoustic pressures ranged from 0 to 8 MPa. Our results, measured in Isoton II (Coulter Diagnostics, Miami, FL) and whole blood solutions, showed that P1 increased with increasing Albunex concentration and decreased with increasing PRF, whereas P2 decreased with increasing Albunex concentration and was independent of the PRF. Both P1 and P2 decreased with increasing number of acoustic cycles N for N < 10 and were independent of the number of cycles for N > 10. Ultrasound images of Albunex acquired by a commercial scanner showed echo enhancement not only at pressure levels below P1 but also at levels above P2. The threshold P2 was achieved at ultrasound energies above the diagnostic level. Inertial cavitation produced at P2 was associated with a higher level of hemolysis compared with P1. The results of this investigation have potential significance for both diagnostic and therapeutic ultrasound applications.

  5. Effect of pulsed ultrasound on the physicochemical characteristics and emulsifying properties of squid (Dosidicus gigas) mantle proteins.

    PubMed

    Higuera-Barraza, O A; Torres-Arreola, W; Ezquerra-Brauer, J M; Cinco-Moroyoqui, F J; Rodríguez Figueroa, J C; Marquez-Ríos, E

    2017-09-01

    Food technologists are always looking to improve the functional properties of proteins. In this sense, in last years ultrasound has been used to improve some functional properties. For this reason, and considering that jumbo squid is an important fishery in northwest Mexico, the purpose of this research was to determine the effect of pulsed ultrasound on the physicochemical characteristics and emulsifying properties of squid (Dosidicus gigas) mantle proteins. Pulsed ultrasound (20kHz, 20, and 40% amplitude) was applied for 30, 60, and 90s to a protein extract prepared from giant squid mantle causing an increase (p<0.05) in surface hydrophobicity (So) from 108.4±1.4 to 239.1±2.4 after application of pulsed ultrasound at 40% of amplitude for 90s. The electrophoretic profile and the total and reactive sulfhydryl contents were not affected (p⩾0.05) by the ultrasound treatment. The emulsifying ability of the protein solution was improved (p<0.05), whereas the Emulsifier Activity Index (EAI) varied from123.67±5.52m(2)/g for the control and increased up to 217.7±3.8m(2)/g after application of the ultrasound. The Stability Emulsifier Index (EEI) was improved at 40% of amplitude by 60 and 90s. The results suggested that pulsed ultrasound used as pretreatment induced conformational changes in giant squid proteins, which improved the interfacial association between protein-oil phases, thus contributing to the improvement of their emulsifient properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Pulsed application of focused ultrasound to the LI4 elicits deqi sensations: pilot study.

    PubMed

    Yoo, Seung-Schik; Lee, Wonhye; Kim, Hyungmin

    2014-08-01

    Focused ultrasound (FUS) techniques enable the delivery of acoustic pressure waves to a localized, specific region of anatomy, and mechanically stimulate the sonicated region when given in a train of pulses. The present pilot study examines if the pulsed application of acoustic waves focused to an acupuncture point (LI4, Hegu), i.e. FUS acupuncture, can elicit deqi sensations. The FUS was generated by a single-element ultrasound transducer, and delivered to the LI4 of acupuncture-naïve participants (n=10) for a duration of 1s using 2 ms tone-burst-duration and 50 Hz pulse repetition frequency. The subjective ratings of deqi descriptors were obtained across different conditions, i.e. FUS acupuncture using acoustic intensities of 1 and 3 W/cm(2) (spatial-peak temporal-averaged intensity, Ispta), sham sonication condition, tactile stimulation using a von Frey monofilament, and needle-based real and sham acupuncture. We also measured the presence of sharp pain, unpleasantness, and anxiety level during each condition. The FUS acupuncture given at 3 W/cm(2) elicited deqi sensation ratings similar to those acquired during the needle-based acupuncture condition across the subjects, with significantly reduced levels of non-deqi related sensations, such as sharp pain, anxiety and unpleasantness. The lower acoustic intensity also generated deqi sensations, but at a lesser degree than the ones acquired using the higher acoustic intensity. Neither the sham conditions nor the tactile stimulation elicited deqi sensations. The present data on acoustic acupuncture, with its exquisite spatial and depth control, along with the ability to electronically adjust its intensity, may suggest its potential utilization as an alternative mode of acupuncture, although further study is needed to probe its clinical efficacy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. High speed imaging of bubble clouds generated in pulsed ultrasound cavitational therapy--histotripsy.

    PubMed

    Xu, Zhen; Raghavan, Mekhala; Hall, Timothy L; Chang, Ching-Wei; Mycek, Mary-Ann; Fowlkes, J Brian; Cain, Charles A

    2007-10-01

    Our recent studies have demonstrated that mechanical fractionation of tissue structure with sharply demarcated boundaries can be achieved using short (< 20 micros), high intensity ultrasound pulses delivered at low duty cycles. We have called this technique histotripsy. Histotripsy has potential clinical applications where noninvasive tissue fractionation and/or tissue removal are desired. The primary mechanism of histotripsy is thought to be acoustic cavitation, which is supported by a temporally changing acoustic backscatter observed during the histotripsy process. In this paper, a fast-gated digital camera was used to image the hypothesized cavitating bubble cloud generated by histotripsy pulses. The bubble cloud was produced at a tissue-water interface and inside an optically transparent gelatin phantom which mimics bulk tissue. The imaging shows the following: (1) Initiation of a temporally changing acoustic backscatter was due to the formation of a bubble cloud; (2) The pressure threshold to generate a bubble cloud was lower at a tissue-fluid interface than inside bulk tissue; and (3) at higher pulse pressure, the bubble cloud lasted longer and grew larger. The results add further support to the hypothesis that the histotripsy process is due to a cavitating bubble cloud and may provide insight into the sharp boundaries of histotripsy lesions.

  8. Biological response in vitro of skeletal muscle cells treated with different intensity continuous and pulsed ultrasound fields

    NASA Astrophysics Data System (ADS)

    Abrunhosa, Viviane M.; Mermelstein, Claudia S.; Costa, Manoel L.; Costa-Felix, Rodrigo P. B.

    2011-02-01

    Therapeutic ultrasound has been used in physiotherapy to accelerate tissue healing. Although the ultrasonic wave is widely used in clinical practice, not much is known about the biological effects of ultrasound on cells and tissues. This study aims to evaluate the biological response of ultrasound in primary cultures of chick myogenic cells. To ensure the metrological reliability of whole measurement process, the ultrasound equipment was calibrated in accordance with IEC 61689:2007. The skeletal muscle cells were divided in four samples. One sample was used as a control group and the others were submitted to different time and intensity and operation mode of ultrasound: 1) 0.5 W/cm2 continuous for 5 minutes, 2) 0.5 W/cm2 pulsed for 5 minutes, 3) 1.0 W/cm2 pulsed for 10 minutes. The samples were analyzed with phase contrast optical microscopy before and after the treatment. The results showed alignment of myogenic cells in the sample treated with 0.5 W/cm2 continuous during 5 minutes when compared with the control group and the other samples. This study is a first step towards a metrological and scientific based protocol to cells and tissues treatment under different ultrasound field exposures.

  9. Characterization of the dynamic activities of a population of microbubbles driven by pulsed ultrasound exposures in sonoporation

    PubMed Central

    Fan, Z.; Chen, D.; Deng, C.X.

    2014-01-01

    Ultrasound driven microbubble activities have been exploited to transiently disrupt the cell membrane (sonoporation) for non-viral intracellular drug delivery and gene transfection both in vivo and in vitro. In this study, we investigated the dynamic behaviors of a population of microbubbles subjected to pulsed ultrasound exposures and their impact on adherent cells in terms of intracellular delivery and cell viability. By systematically analyzing the bubble activities at time scales relevant to pulsed ultrasound exposures, we identified two quantification parameters that categorized the diverse bubble activities subjected to various ultrasound conditions into three characteristic behaviors, i.e., stable cavitation/aggregation (Type I), growth/coalescence and translation (Type II), and localized inertial cavitation/collapse (Type III). Correlation of the bubble activities with sonoporation outcome suggested that Type III behavior resulted in intracellular delivery, while Type II behavior caused death of a large number of cells. These results provide useful insights for rational selection of ultrasound parameters to optimize outcomes of sonoporation and other applications that exploit the use of ultrasound-driven bubble activities. PMID:24486236

  10. In vitro comparative study of vibro-acoustography versus pulse-echo ultrasound in imaging permanent prostate brachytherapy seeds

    PubMed Central

    Mitri, F.G.; Davis, B.J.; Greenleaf, J.F.; Fatemi, M.

    2010-01-01

    Background Permanent prostate brachytherapy (PPB) is a common treatment for early stage prostate cancer. While the modern approach using trans-rectal ultrasound guidance has demonstrated excellent outcome, the efficacy of PPB depends on achieving complete radiation dose coverage of the prostate by obtaining a proper radiation source (seed) distribution. Currently, brachytherapy seed placement is guided by trans-rectal ultrasound imaging and fluoroscopy. A significant percentage of seeds are not detected by trans-rectal ultrasound because certain seed orientations are invisible making accurate intra-operative feedback of radiation dosimetry very difficult, if not impossible. Therefore, intra-operative correction of suboptimal seed distributions cannot easily be done with current methods. Vibro-acoustography (VA) is an imaging modality that is capable of imaging solids at any orientation, and the resulting images are speckle free. Objective and methods The purpose of this study is to compare the capabilities of VA and pulse-echo ultrasound in imaging PPB seeds at various angles and show the sensitivity of detection to seed orientation. In the VA experiment, two intersecting ultrasound beams driven at f1 = 3.00 MHz and f2 = 3.020 MHz respectively were focused on the seeds attached to a latex membrane while the amplitude of the acoustic emission produced at the difference frequency 20 kHz was detected by a low frequency hydrophone. Results Finite element simulations and results of experiments conducted under well-controlled conditions in a water tank on a series of seeds indicate that the seeds can be detected at any orientation with VA, whereas pulse-echo ultrasound is very sensitive to the seed orientation. Conclusion It is concluded that vibro-acoustography is superior to pulse-echo ultrasound for detection of PPB seeds. PMID:18538365

  11. The impact of pulsed electric fields and ultrasound on water distribution and loss in mushrooms stalks.

    PubMed

    Dellarosa, Nicolò; Frontuto, Daniele; Laghi, Luca; Dalla Rosa, Marco; Lyng, James G

    2017-12-01

    Pulsed electric fields (PEF) and ultrasound (US) are promising innovative technologies with the potential to increase mass transfer when combined with further processes which in turn can provide potential benefits in the recovery of valuable compounds from food by-products. To provide evidence of the mechanism of mass transfer enhancement, the present study assessed the impact of PEF and US treatments, applied individually and in combination, at low and high temperatures, on the tissue microstructure of mushroom stalks. Different indices such as quantitative water redistribution, water loss and qualitative release of compounds were evaluated. The combination of these physical methods demonstrated that PEF redistributed a greater proportion of intracellular water into extracellular spaces than US. However, the application of high temperature treatments alone showed an even greater proportion of intracellular water migration compared to PEF. When PEF was combined with US at low temperatures the difference was not significant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Ultrasound-modulated optical imaging using a powerful long pulse laser.

    PubMed

    Rousseau, Guy; Blouin, Alain; Monchalin, Jean-Pierre

    2008-08-18

    Ultrasound-modulated optical imaging (or tomography) is an emerging biodiagnostic technique which provides the optical spectroscopic signature and the localization of an absorbing object embedded in a strongly scattering medium. We propose to improve the sensitivity of the technique by using a pulsed single-frequency laser to raise the optical peak power applied to the scattering medium and thereby collect more ultrasonically tagged photons. Moreover, when the detection of tagged photons is done with a photorefractive interferometer, the high optical peak power reduces the response time of the photorefractive crystal below the speckle field decorrelation time. Results obtained with a GaAs photorefractive interferometer are presented for 30- and 60-mm thick scattering media.

  13. Ultrasound-Guided Pulsed Radiofrequency for Carpal Tunnel Syndrome: A Single-Blinded Randomized Controlled Study.

    PubMed

    Chen, Liang-Cheng; Ho, Cheng-Wen; Sun, Chia-Hung; Lee, Jiunn-Tay; Li, Tsung-Ying; Shih, Feng-Mei; Wu, Yung-Tsan

    2015-01-01

    We assessed the therapeutic efficiency of ultrasound-guided pulsed radiofrequency (PRF) treatment of the median nerve in patients with carpal tunnel syndrome (CTS). We conducted a prospective, randomized, controlled, single-blinded study. Forty-four patients with CTS were randomized into intervention or control groups. Patients in the intervention group were treated with PRF and night splint, and the control group was prescribed night splint alone. Primary outcome was the onset time of significant pain relief assessed using the visual analog scale (VAS), and secondary outcomes included evaluation of the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) results, cross-sectional area (CSA) of the median nerve, sensory nerve conduction velocity (SNCV) of the median nerve, and finger pinch strength. All outcome measurements were performed at 1, 4, 8, and 12 weeks after treatment. Thirty-six patients completed the study. The onset time of pain relief in the intervention group was significantly shorter (median onset time of 2 days vs. 14 days; hazard ratio = 7.37; 95% CI, 3.04-17.87) compared to the control group (p < 0.001). Significant improvement in VAS and BCTQ scores (p < 0.05) was detected in the intervention group at all follow-up periods compared to the controls (except for the severity subscale of BCTQ at week 1). Ultrasound-guided PRF treatment resulted in a lower VAS score and stronger finger pinch compared to the control group over the entire study. Our study shows that ultrasound-guided PRF serves as a better approach for pain relief in patients with CTS. ClinicalTrials.gov NCT02217293.

  14. Ultrasound-Guided Pulsed Radiofrequency for Carpal Tunnel Syndrome: A Single-Blinded Randomized Controlled Study

    PubMed Central

    2015-01-01

    Objective We assessed the therapeutic efficiency of ultrasound-guided pulsed radiofrequency (PRF) treatment of the median nerve in patients with carpal tunnel syndrome (CTS). Methods We conducted a prospective, randomized, controlled, single-blinded study. Forty-four patients with CTS were randomized into intervention or control groups. Patients in the intervention group were treated with PRF and night splint, and the control group was prescribed night splint alone. Primary outcome was the onset time of significant pain relief assessed using the visual analog scale (VAS), and secondary outcomes included evaluation of the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) results, cross-sectional area (CSA) of the median nerve, sensory nerve conduction velocity (SNCV) of the median nerve, and finger pinch strength. All outcome measurements were performed at 1, 4, 8, and 12 weeks after treatment. Results Thirty-six patients completed the study. The onset time of pain relief in the intervention group was significantly shorter (median onset time of 2 days vs. 14 days; hazard ratio = 7.37; 95% CI, 3.04–17.87) compared to the control group (p < 0.001). Significant improvement in VAS and BCTQ scores (p < 0.05) was detected in the intervention group at all follow-up periods compared to the controls (except for the severity subscale of BCTQ at week 1). Ultrasound-guided PRF treatment resulted in a lower VAS score and stronger finger pinch compared to the control group over the entire study. Conclusions Our study shows that ultrasound-guided PRF serves as a better approach for pain relief in patients with CTS. Trial Registration ClinicalTrials.gov NCT02217293 PMID:26067628

  15. Measurement of the contrast agent intrinsic and native harmonic response with single transducer pulse waved ultrasound systems.

    PubMed

    Verbeek, X A; Willigers, J M; Brands, P J; Ledoux, L A; Hoeks, A P

    1999-01-01

    Ultrasound contrast agents, i.e., small gas filled microbubbles, enhance the echogenicity of blood and have the potential to be used for tissue perfusion assessment. The contrast agents scatter ultrasound in a nonlinear manner and thereby introduce harmonics in the ultrasound signal. This property is exploited in new ultrasound techniques like harmonic imaging, which aims to display only the contrast agent presence. Much attention has already been given to the physical properties of the contrast agent. The present study focuses on practical aspects of the measurement of the intrinsic harmonic response of ultrasound contrast agents with single transducer pulse waved ultrasound systems. Furthermore, the consequences of two other sources of harmonics are discussed. These sources are the nonlinear distortion of ultrasound in a medium generating native harmonics, and the emitted signal itself which might contain contaminating harmonics. It is demonstrated conceptually and by experiments that optimization of the contrast agent harmonic response measured with a single transducer is governed by the transducer spectral sensitivity distribution rather than the resonance properties of the contrast agent. Both native and contaminating harmonics may be of considerable strength and can be misinterpreted as intrinsic harmonics of the contrast agent. Practical difficulties to filter out the harmonic component selectively, without deteriorating the image, may cause misinterpretation of the fundamental as a harmonic.

  16. Effect of pulse repetition frequency of high-intensity focused ultrasound on in vitro thrombolysis.

    PubMed

    Yang, Wenjing; Zhou, Yufeng

    2017-03-01

    Vascular occlusion by the thrombi is the main reason for ischemic stroke and deep vein thrombosis. High-intensity focused ultrasound (HIFU) and histotripsy or microtripsy pulses can effectively dissolve the blood clot with no use of thrombolytic agent and ultrasound contrast agent (microbubbles). In this study, HIFU bursts at the same duty cycle (2%) but varied pulse repetition frequency (PRF) from 1Hz to 1000Hz were delivered to in vitro porcine blood clot for 30s. Thrombolysis efficiency initially increases slightly with the PRF, 86.4±10.3%, 89.9±11.9, and 92.9±12.8% at the PRF of 1Hz, 10Hz, and 100Hz, respectively, without significant difference (p>0.05), but then drops dramatically to 37.9±6.9% at the PRF of 1000Hz (p<0.05). The particle size in the supernatant of dissolution is 547.1±129.5nm, which suggests the disruption of thrombi into the subcellular level. Thrombi motion during HIFU exposure shows violent motion and significant curling at the low PRF, rotation about its axis with occasional curling at the moderate PRF, and localized vibration at the high PRF due to the generation of acoustic radiation force and streaming. Quantitative analysis of recorded motion shows the axial displacement decreases with the PRF of delivered HIFU bursts, from 3.9±1.5mm at 1Hz to 0.7±0.4mm at 1000Hz. Bubble cavitation during HIFU exposure to the blood clot was also monitored. The increase of PRF led to the increase of inertial cavitation but the decrease of stable cavitation. In summary, the PRF of delivered HIFU bursts at the same output energy has a significant effect on the thrombi motion, bubble cavitation activities, and subsequently thrombolysis efficiencies.

  17. Evaluation of the increase in permeability of the blood-brain barrier during tumor progression after pulsed focused ultrasound.

    PubMed

    Yang, Feng-Yi; Wang, Hsin-Ell; Lin, Guan-Liang; Lin, Hui-Hsien; Wong, Tai-Tong

    2012-01-01

    The purpose of this study was to evaluate the permeability of the blood-brain barrier after sonication by pulsed high-intensity focused ultrasound and to determine if such an approach increases the tumor:ipsilateral brain permeability ratio. F98 glioma-bearing Fischer 344 rats were injected intravenously with Evans blue with or without blood-tumor barrier disruption induced by transcranial pulsed high-intensity focused ultrasound. Sonication was applied at a frequency of 1 MHz with a 5% duty cycle and a repetition frequency of 1 Hz. The permeability of the blood-brain barrier was assessed by the extravasation of Evans blue. Contrast-enhanced magnetic resonance images were used to monitor the gadolinium deposition path associated with transcranial pulsed high-intensity focused ultrasound, and the influencing size and location was also investigated. In addition, whole brain histological analysis was performed. The results were compared by two-tailed unpaired t-test. The accumulation of Evans blue in brains and the tumor:ipsilateral brain permeability ratio of Evans blue were significantly increased after pulsed high-intensity focused ultrasound exposure. Evans blue injection followed by sonication showed an increase in the tumor:ipsilateral brain ratio of the target tumors (9.14:1) of about 2.23-fold compared with the control tumors (x4.09) on day 6 after tumor implantation. Magnetic resonance images showed that pulsed high-intensity focused ultrasound locally enhances the permeability of the blood-tumor barrier in the glioma-bearing rats. This method could allow enhanced synergistic effects with respect to other brain tumor treatment regimens.

  18. Low intensity laser treatment of nerve injuries

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Guang; Liu, Timon Cheng-Yi; Luo, Qing-Ming

    2007-05-01

    The neural regeneration and functional recovery after nerve injuries has long been an important field in neuroscience. Low intensity laser (LIL) irradiation is a novel and useful tool for the treatment of many injuries and disorders. The aim of this study was to assess the role of LIL irradiation in the treatment of peripheral and central nerve injuries. Some animal experiments and clinical investigations have shown beneficial effects of LIL irradiation on neural tissues, but its therapeutic value and efficacy are controversial. Reviewing the data of experimental and clinical studies by using the biological information model of photobiomodulation, we conclude that LIL irradiation in specific parameters can promote the regeneration of injured peripheral and central nerves and LIL therapy is a safe and valuable treatment for superficial peripheral nerve injuries and spinal cord injury. The biological effects of LIL treatment depend largely on laser wavelength, power and dose per site and effective irradiation doses are location-specific.

  19. Low-Intensity Repetitive Exercise Induced Rhabdomyolysis.

    PubMed

    Tran, Mina; Hayden, Nicholas; Garcia, Brandon; Tucci, Veronica

    2015-01-01

    Rhabdomyolysis is a rare condition caused by the proteins of damaged muscle cells entering the bloodstream and damaging the kidneys. Common symptoms of rhabdomyolysis are muscle pain and fatigue in conjunction with dark urine; kidney damage is a common symptom among these patients. We present a case of a 23-year-old woman who displayed myalgia in the upper extremities caused by low-intensity and high-repetition exercise. She was successfully diagnosed and treated for exertional rhabdomyolysis. This patient had no significant medical history that would induce this condition. We urge the emergency medical community to observe and monitor patients that complain of myalgia to ensure they are not suffering from rhabdomyolysis even in atypical cases.

  20. Low-Intensity Repetitive Exercise Induced Rhabdomyolysis

    PubMed Central

    Tran, Mina; Hayden, Nicholas; Garcia, Brandon; Tucci, Veronica

    2015-01-01

    Rhabdomyolysis is a rare condition caused by the proteins of damaged muscle cells entering the bloodstream and damaging the kidneys. Common symptoms of rhabdomyolysis are muscle pain and fatigue in conjunction with dark urine; kidney damage is a common symptom among these patients. We present a case of a 23-year-old woman who displayed myalgia in the upper extremities caused by low-intensity and high-repetition exercise. She was successfully diagnosed and treated for exertional rhabdomyolysis. This patient had no significant medical history that would induce this condition. We urge the emergency medical community to observe and monitor patients that complain of myalgia to ensure they are not suffering from rhabdomyolysis even in atypical cases. PMID:26693360

  1. Dependence of pulsed focused ultrasound induced thrombolysis on duty cycle and cavitation bubble size distribution.

    PubMed

    Xu, Shanshan; Zong, Yujin; Feng, Yi; Liu, Runna; Liu, Xiaodong; Hu, Yaxin; Han, Shimin; Wan, Mingxi

    2015-01-01

    In this study, we investigated the relationship between the efficiency of pulsed, focused ultrasound (FUS)-induced thrombolysis, the duty cycle (2.3%, 9%, and 18%) and the size distribution of cavitation bubbles. The efficiency of thrombolysis was evaluated through the degree of mechanical fragmentation, namely the number, mass, and size of clot debris particles. First, we found that the total number and mass of clot debris particles were highest when a duty cycle of 9% was used and that the mean diameter of clot debris particles was smallest. Second, we found that the size distribution of cavitation bubbles was mainly centered around the linear resonance radius (2.5μm) of the emission frequency (1.2MHz) of the FUS transducer when a 9% duty cycle was used, while the majority of cavitation bubbles became smaller or larger than the linear resonance radius when a 2.3% or 18% duty cycle was used. In addition, the inertial cavitation dose from the treatment performed at 9% duty cycle was much higher than the dose obtained with the other two duty cycles. The data presented here suggest that there is an optimal duty cycle at which the thrombolysis efficiency and cavitation activity are strongest. They further indicate that using a pulsed FUS may help control the size distribution of cavitation nuclei within an active size range, which we found to be near the linear resonance radius of the emission frequency of the FUS transducer.

  2. Study of the inactivation of spoilage microorganisms in apple juice by pulsed light and ultrasound.

    PubMed

    Ferrario, Mariana; Alzamora, Stella Maris; Guerrero, Sandra

    2015-04-01

    The aim of this study was to evaluate the effect of ultrasound (US) (600 W, 20 kHz and 95.2 μm wave amplitude; 10 or 30 min at 20, 30 or 44 ± 1 °C) and pulsed light (PL) (Xenon lamp; 3 pulses/s; 0.1 m distance; 2.4 J/cm(2)-71.6 J/cm(2); initial temperature 2, 30, 44 ± 1 °C) on the inactivation of Alicyclobacillus acidoterrestris ATCC 49025 spores and Saccharomyces cerevisiae KE162 inoculated in commercial (pH: 3.5; 12.5 °Brix) and natural squeezed (pH: 3.4; 11.8 °Brix) apple juices. Inactivation depended on treatment time, temperature, microorganism and matrix. Combination of these technologies led up to 3.0 log cycles of spore reduction in commercial apple juice and 2.0 log cycles in natural juice; while for S. cerevisiae, 6.4 and 5.8 log cycles of reduction were achieved in commercial and natural apple juices, respectively. In natural apple juice, the combination of US + 60 s PL at the highest temperature build-up (56 ± 1 °C) was the most effective treatment for both strains. In commercial apple juice, US did not contribute to further inactivation of spores, but significantly reduced yeast population. Certain combinations of US + PL kept on good microbial stability under refrigerated conditions for 15 days.

  3. Computed ultrasound tomography in echo mode for imaging speed of sound using pulse-echo sonography: proof of principle.

    PubMed

    Jaeger, Michael; Held, Gerrit; Peeters, Sara; Preisser, Stefan; Grünig, Michael; Frenz, Martin

    2015-01-01

    The limitations of diagnostic echo ultrasound have motivated research into novel modalities that complement ultrasound in a multimodal device. One promising candidate is speed of sound imaging, which has been found to reveal structural changes in diseased tissue. Transmission ultrasound tomography shows speed of sound spatially resolved, but is limited to the acoustically transparent breast. We present a novel method by which speed-of-sound imaging is possible using classic pulse-echo equipment, facilitating new clinical applications and the combination with state-of-the art diagnostic ultrasound. Pulse-echo images are reconstructed while scanning the tissue under various angles using transmit beam steering. Differences in average sound speed along different transmit directions are reflected in the local echo phase, which allows a 2-D reconstruction of the sound speed. In the present proof-of-principle study, we describe a contrast resolution of 0.6% of average sound speed and a spatial resolution of 1 mm (laterally) × 3 mm (axially), suitable for diagnostic applications. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  4. Low intensity laser therapy: the clinical approach

    NASA Astrophysics Data System (ADS)

    Kahn, Fred

    2006-02-01

    Recently, there has been significant improvement in the process of research and application of Low Intensity Laser Therapy (LILT). Despite this positive direction, a wide discrepancy between the research component and clinical understanding of the technology remains. In our efforts to achieve better clinical results and more fully comprehend the mechanisms of interaction between light and cells, further studies are required. The clinical results presented in this paper are extrapolated from a wide range of musculoskeletal problems including degenerative osteoarthritis, repetitive motion injuries, sports injuries, etc. The paper includes three separate clinical studies comprising 151, 286 and 576 consecutive patient discharges at our clinic. Each patient studied received a specific course of treatment that was designed for that individual and was modified on a continuing basis as the healing process advanced. On each visit, clinical status correlation with the duration, dosage and other parameters was carried out. The essentials of the treatment consisted of a three stage approach. This involved a photon stream emanating from a number of specified gallium-aluminum-arsenide diodes; stage one, red light array, stage two consisting of an array of infrared diodes and stage three consisting of the application of an infrared laser diode probe. On average, each of these groups required less than 10 treatments per patient and resulted in a significant improvement / cure rate greater than 90% in all conditions treated. This report clearly demonstrates the benefits of LILT, indicating that it should be more widely adapted in all medical therapeutic settings.

  5. Ultrasound

    MedlinePlus Videos and Cool Tools

    ... baby's development in the uterus. Ultrasound uses inaudible sound waves to produce a two-dimensional image of the baby while inside the mother's uterus. The sound waves bounce off solid structures in the body ...

  6. Ultrasound

    MedlinePlus

    ... called multiples) To screen for birth defects, like spina bifida or heart defects . Screening means seeing if your ... example, if the ultrasound shows your baby has spina bifida, she may be treated in the womb before ...

  7. Ultrasound

    MedlinePlus

    ... a pregnant woman and assess her fetus Diagnose gallbladder disease Evaluate flow in blood vessels Guide a ... For some ultrasound exams, such as of the gallbladder, your doctor may ask that you not eat ...

  8. Intracranial Applications of MR Imaging-Guided Focused Ultrasound.

    PubMed

    Khanna, N; Gandhi, D; Steven, A; Frenkel, V; Melhem, E R

    2017-03-01

    Initially used in the treatment of prostate cancer and uterine fibroids, the role of focused ultrasound has expanded as transcranial acoustic wave distortion and other limitations have been overcome. Its utility relies on focal energy deposition via acoustic wave propagation. The duty cycle and intensity of focused ultrasound influence the rate of energy deposition and result in unique physiologic and biomechanical effects. Thermal ablation via high-intensity continuous exposure generates coagulative necrosis of tissues. High-intensity, pulsed application reduces temporally averaged energy deposition, resulting in mechanical effects, including reversible, localized BBB disruption, which enhances neurotherapeutic agent delivery. While the precise mechanisms remain unclear, low-intensity, pulsed exposures can influence neuronal activity with preservation of cytoarchitecture. Its noninvasive nature, high-resolution, radiation-free features allow focused ultrasound to compare favorably with other modalities. We discuss the physical characteristics of focused ultrasound devices, the biophysical mechanisms at the tissue level, and current and emerging applications.

  9. Low-intensity calibration source for optical imaging systems

    NASA Astrophysics Data System (ADS)

    Holdsworth, David W.

    2017-03-01

    Laboratory optical imaging systems for fluorescence and bioluminescence imaging have become widely available for research applications. These systems use an ultra-sensitive CCD camera to produce quantitative measurements of very low light intensity, detecting signals from small-animal models labeled with optical fluorophores or luminescent emitters. Commercially available systems typically provide quantitative measurements of light output, in units of radiance (photons s-1 cm-2 SR-1) or intensity (photons s-1 cm-2). One limitation to current systems is that there is often no provision for routine quality assurance and performance evaluation. We describe such a quality assurance system, based on an LED-illuminated thin-film transistor (TFT) liquid-crystal display module. The light intensity is controlled by pulse-width modulation of the backlight, producing radiance values ranging from 1.8 x 106 photons s-1 cm-2 SR-1 to 4.2 x 1013 photons s-1 cm-2 SR-1. The lowest light intensity values are produced by very short backlight pulses (i.e. approximately 10 μs), repeated every 300 s. This very low duty cycle is appropriate for laboratory optical imaging systems, which typically operate with long-duration exposures (up to 5 minutes). The low-intensity light source provides a stable, traceable radiance standard that can be used for routine quality assurance of laboratory optical imaging systems.

  10. Influence Of Low Intensity Laser Therapy On Diabetic Polyneuropathy

    NASA Astrophysics Data System (ADS)

    Abdel-Raoof, N. A.; Elnhas, N. G.; Elsayed, I. M.

    2011-09-01

    Diabetic peripheral neuropathy is a consequence of diabetes-mediated impairment of blood flow, and resultant hypoxia of nerves that may develop within 10 years of the onset of diabetes in 40-50% of people with type 1 or type 2 diabetes. Low Intensity Laser Therapy (LILT) has been advocated for the treatment of chronic pain disorders as blood flow is an important determinant for pain relief. Comparing the effect of Helium-Neon Laser therapy versus Infrared laser therapy on blood vessels diameter and flow as well as level of sensation for neuropathy. Twenty diabetic patients suffering from neuropathy were enrolled in the study with age 45-55 years. They were assigned randomly into two equal groups in number; Group A underwent an application of He-Neon laser while Group B underwent an application of Infrared laser. Both groups received laser for 2 months. Blood flow velocity, and blood vessel diameter were investigated by using duplex Doppler ultrasound and peripheral neuropathy parameters were investigated by Semmes-Weinstein monofilament assessment. The results revealed that He-Neon laser as well as Infrared laser groups showed significant improvement in blood flow velocity, blood vessel diameter & neuropathy tested parameters after treatment but there was no significance difference between the two types of LILT. LILT is a safe, non-invasive and drug free method for improving blood flow & sensation in patients suffering from diabetic polyneuropathy in addition to preventing one of the most threatening microvascular complications of diabetes.

  11. Nonlinear propagation acoustics of dual-frequency wide-band excitation pulses in a focused ultrasound system.

    PubMed

    Måsøy, Svein-Erik; Standal, Øyvind; Deibele, Jochen M; Näsholm, Sven Peter; Angelsen, Bjørn; Johansen, Tonni F; Tangen, Thor Andreas; Hansen, Rune

    2010-11-01

    In this article, acoustic propagation effects of dual-frequency wide-band excitation pulses in a focused ultrasound system are demonstrated in vitro. A designed and manufactured dual-frequency band annular array capable of transmitting 0.9/7.5 MHz center frequency wide-band pulses was used for this purpose. The dual-frequency band annular array, has been designed using a bi-layer piezo-electric stack. Water tank measurements demonstrate the function of the array by activating the low- and high-frequency layers individually and simultaneously. The results show that the array works as intended. Activating the low- and high-frequency layers individually, results in less than -50 dB signal level from the high- and low-frequency layers respectively. Activating both layers simultaneously, produce a well defined dual-frequency pulse. The presence of the low-frequency pulse leads to compression, expansion, and a time delay of the high-frequency pulse. There is a phase shift between the low- and high-frequency pulse as it propagates from the array to the focus. This makes the latter described effects also dependent on the array configuration. By varying the low-frequency pressure, a shift of up to 0.5 MHz in center frequency of a 8.0 MHz transmitted high-frequency pulse is observed at the array focus. The results demonstrate the high propagation complexity of dual-frequency pulses.

  12. Enzymolysis kinetics, thermodynamics and model of porcine cerebral protein with single-frequency countercurrent and pulsed ultrasound-assisted processing.

    PubMed

    Zou, Ye; Ding, Yangyang; Feng, Weiwei; Wang, Wei; Li, Qian; Chen, Yao; Wu, Huiyu; Wang, Xintong; Yang, Liuqing; Wu, Xiangyang

    2016-01-01

    The present work investigated the enzymolysis kinetics, thermodynamics and model of porcine cerebral protein (PCP) which was pretreated by single-frequency countercurrent and pulsed ultrasound. The kinetic constants for ultrasonic pretreated and traditional enzymolysis have been determined. Results showed that the value of KM in ultrasonic PCP (UPCP) enzymolysis decreased by 9% over that in the traditional enzymolysis. The values of reaction rate constant (k) for UPCP enzymolysis increased by 207%, 121%, 62%, and 45% at 293, 303, 313 and 323 K, respectively. For the thermodynamic parameters, ultrasound decreased activation energy (Ea), change in enthalpy (ΔH) and entropy (ΔS) by 76%, 82% and 31% in PCP, respectively. However, ultrasound had little change in Gibbs free energy (ΔG) value in the temperature range of 293-323 K. Therefore, a general kinetic equation for the enzymolysis model of UPCP by a simple empirical equation was suggested. The experimental values fits with the enzymolysis kinetic model with a low average relative error (4%) confirmed that the kinetic model was accurate to reflect the enzymolysis process. The positive effect of single-frequency countercurrent and pulsed ultrasound in this study and application of the kinetic model may be useful for the release of bioactive peptides from meat processing by-products. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Heating of tissues in vivo by pulsed focused ultrasound to stimulate enhanced HSP expression

    NASA Astrophysics Data System (ADS)

    Kujawska, Tamara; Wójcik, Janusz; Nowicki, Andrzej

    2011-09-01

    The main aim of this work was numerical modeling of temperature fields induced in soft tissues in vivo by pulsed focused ultrasound during neurodegenerative disease treatment and experimental verification of the proposed model for a rat liver. The new therapeutic approach to neurodegenerative diseases consists of stimulation of enhanced expression of the Heat Shock Proteins (HSP) which are responsible for immunity of cells to stress. During therapy the temperature rise in tissues in vivo should not exceed 6 °C above level of the thermal norm (37 °C). First, the 3D acoustic pressure field, and the rate of heat production per unit volume due to that field, were calculated using our 3D numerical solver capable of predicting nonlinear propagation of pulsed high intensity waves generated from circular focused acoustic sources in multilayer configuration of attenuating media. The two-layer configuration of media (water—rat liver) assumed in calculations fairly well approximated both the real anatomic dimensions of rat liver and the geometric scheme of our experimental set-up. A numerical solution of the Pennes bio-heat transfer equation which accounted for the effects of heat diffusion, blood perfusion and metabolism rates, was employed to calculate the temperature fields induced in the rat liver by the ultrasonic beam. The numerical simulation results were verified experimentally using a thermocouple inserted in the liver of a rat under anesthesia at the beam focus. The quantitative analysis of the obtained results enabled estimation of the effects of several acoustic and thermal parameters of the rat liver in vivo on the temperature rise, as well as determination of exposure time for ultrasonic beams with varied acoustic power generated by a 2-MHz circular transducer of 15-mm diameter and 25-mm focal length, in order to avoid the tissue overheating that leads to cells necrosis, which would be unacceptable in neurodegenerative disease treatment.

  14. Investigation of Cellular and Molecular Responses to Pulsed Focused Ultrasound in a Mouse Model

    PubMed Central

    Burks, Scott R.; Ziadloo, Ali; Hancock, Hilary A.; Chaudhry, Aneeka; Dean, Dana D.; Lewis, Bobbi K.; Frenkel, Victor; Frank, Joseph A.

    2011-01-01

    Continuous focused ultrasound (cFUS) has been widely used for thermal ablation of tissues, relying on continuous exposures to generate temperatures necessary to induce coagulative necrosis. Pulsed FUS (pFUS) employs non-continuous exposures that lower the rate of energy deposition and allow cooling to occur between pulses, thereby minimizing thermal effects and emphasizing effects created by non-thermal mechanisms of FUS (i.e., acoustic radiation forces and acoustic cavitation). pFUS has shown promise for a variety of applications including drug and nanoparticle delivery; however, little is understood about the effects these exposures have on tissue, especially with regard to cellular pro-homing factors (growth factors, cytokines, and cell adhesion molecules). We examined changes in murine hamstring muscle following pFUS or cFUS and demonstrate that pFUS, unlike cFUS, has little effect on the histological integrity of muscle and does not induce cell death. Infiltration of macrophages was observed 3 and 8 days following pFUS or cFUS exposures. pFUS increased expression of several cytokines (e.g., IL-1α, IL-1β, TNFα, INFγ, MIP-1α, MCP-1, and GMCSF) creating a local cytokine gradient on days 0 and 1 post-pFUS that returns to baseline levels by day 3 post-pFUS. pFUS exposures induced upregulation of other signaling molecules (e.g., VEGF, FGF, PlGF, HGF, and SDF-1α) and cell adhesion molecules (e.g., ICAM-1 and VCAM-1) on muscle vasculature. The observed molecular changes in muscle following pFUS may be utilized to target cellular therapies by increasing homing to areas of pathology. PMID:21931834

  15. Direct effect of diagnostic ultrasound on genetically interesting molecules

    SciTech Connect

    Ciatti, S.; Domokos, G.; Koevesi-Domokos, S.; Milano, F.

    1981-01-01

    Ultrasound is a non-ionizing radiation and at typical intensities used in diagnostic sonography, macroscopic damage to tissues is negligible. Some recent experiments, however, provided evidence for possible genetic damage caused by relatively low-intensity ultrasound irradiation. Although the implications of such experiments concerning possible genetic damage caused by low intensity ultrasound irradiation are not yet completely understood, the very existence of such results raises an important theoretical question. Is it possible that a non-ionizing radiation can cause significant changes in the structure of a typical DNA molecule. Several mechanisms exist which are responsible for such changes including: (1) structural changes in the molecule due to sound absorption from a high harmonic of the repetition frequency of a pulsed ultrasound radiation; (2) structural changes due to multi-phonon absorption from low harmonics of the repetition frequency; and (3) break-up of the molecule as a consequence of the excitation of collective vibrations. The calculations presented suggest that, should damage to DNA in vitro caused by low-intensity ultrasound be confirmed beyond reasonable doubt, such catastrophic changes in the structure of DNA molecules are more likely to arise as a result of their collective modes rather than from a localizable breakup of some hydrogen bonds. (ERB)

  16. A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force.

    PubMed

    Yoon, Sangpil; Aglyamov, Salavat; Karpiouk, Andrei; Emelianov, Stanislav

    2012-08-07

    A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young's moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young's moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed.

  17. Noninvasive Ureterocele Puncture Using Pulsed Focused Ultrasound: An In Vitro Study

    PubMed Central

    Hsi, Ryan S.; Bailey, Michael R.; Casale, Pasquale; Lendvay, Thomas S.

    2014-01-01

    Abstract Purpose: To evaluate the feasibility of performing noninvasive puncture of pediatric ureteroceles with cavitation-based focused ultrasound (US) (histotripsy). Materials and Methods: A model for the ureterocele wall was developed from an excised bovine bladder wall. The model was exposed to focused US pulses in a water bath under three different US parameter sets for up to 300 seconds to create localized perforations in the wall. B-mode US imaging was used to monitor the treatment and assess potential imaging guidance and feedback. Results: Punctures were formed between 46–300 seconds, depending on the focused US exposure parameters and model wall thickness. Puncture diameter was controllable through choice of exposure parameters and could be varied between 0.8–2.8 mm mean diameter. US-induced cavitation was visible on B-mode imaging, which provided targeting and treatment feedback. Conclusions: Cavitation-based focused US can create punctures in a model that mimics the tissue properties of a ureterocele wall, under guidance from US imaging. PMID:24171441

  18. Therapeutic ultrasound plus pulsed electromagnetic field improves recovery from peripheral arterial disease in hypertension

    PubMed Central

    Lu, Zhao-Yang; Zhou, Hong-Sheng; Su, Zhi-Xiao; Qi, Jia; Zhang, Jian; Xue, Guan-Hua; Li, Yue; Hao, Chang-Ning; Shi, Yi-Qin; Duan, Jun-Li

    2017-01-01

    The objective of this investigation was to evaluate the therapy effect of combined therapeutic ultrasound (TUS) treatment and pulsed electromagnetic field (PEMF) therapy on angiogenesis in hypertension-related hindlimb ischemia. After subjecting excision of the left femoral artery, spontaneously hypertensive rats (SHRs) were randomly distributed to one of four groups: SHR; TUS treated SHR (SHR-TUS); PEMF treated SHR (PEMF-TUS); and TUS plus PEMF treated SHR (SHR-TUS-PEMF). Wistar-Kyoto rats (WKYs) with femoral artery excision were regarded as a control group. At day 14 after surgery, the TUS plus PEMF united administration had the greatest blood perfusion accompanied by elevated capillary density and the lowest TUNEL index. Interestingly, the united administration up-regulated the angiogenic factors expression of phosphorylated Akt (p-Akt), phosphorylated endothelial nitric oxide synthase (p-eNOS), vascular endothelial growth factor (VEGF), anti-apoptotic protein of Bcl-2 and down-regulated pro-apoptotic protein levels of Bax and Cleaved caspase-3 in vivo. Our results demonstrated that the united administration could significantly rescue hypertension-related inhibition of ischemia-induced neovascularization partly by promoting angiogenesis and inhibiting apoptosis.

  19. Pulsed magnetic field induced fast drug release from magneto liposomes via ultrasound generation.

    PubMed

    Podaru, George; Ogden, Saralyn; Baxter, Amanda; Shrestha, Tej; Ren, Shenqiang; Thapa, Prem; Dani, Raj Kumar; Wang, Hongwang; Basel, Matthew T; Prakash, Punit; Bossmann, Stefan H; Chikan, Viktor

    2014-10-09

    Fast drug delivery is very important to utilize drug molecules that are short-lived under physiological conditions. Techniques that can release model molecules under physiological conditions could play an important role to discover the pharmacokinetics of short-lived substances in the body. Here an experimental method is developed for the fast release of the liposomes' payload without a significant increase in (local) temperatures. This goal is achieved by using short magnetic pulses to disrupt the lipid bilayer of liposomes loaded with magnetic nanoparticles. The drug release has been tested by two independent assays. The first assay relies on the AC impedance measurements of MgSO4 released from the magnetic liposomes. The second standard release assay is based on the increase of the fluorescence signal from 5(6)-carboxyfluorescein dye when the dye is released from the magneto liposomes. The efficiency of drug release ranges from a few percent to up to 40% in the case of the MgSO4. The experiments also indicate that the magnetic nanoparticles generate ultrasound, which is assumed to have a role in the release of the model drugs from the magneto liposomes.

  20. Effects of beam steering in pulsed-wave ultrasound velocity estimation.

    PubMed

    Steinman, Aaron H; Yu, Alfred C H; Johnston, K Wayne; Cobbold, Richard S C

    2005-08-01

    Experimental and computer simulation methods have been used to investigate the significance of beam steering as a potential source of error in pulsed-wave flow velocity estimation. By simulating a typical linear-array transducer system as used for spectral flow estimation, it is shown that beam steering can cause an angle offset resulting in a change in the effective beam-flow angle. This offset primarily depends on the F-number and the nominal steering angle. For example, at an F-number of 3 and a beam-flow angle of 70 degrees , the velocity error changed from -5% to + 5% when the steering angle changed from -20 degrees to + 20 degrees . Much higher errors can occur at higher beam-flow angles, with smaller F-numbers and greater steering. Our experimental study used a clinical ultrasound system, a tissue-mimicking phantom and a pulsatile waveform to determine peak flow velocity errors for various steering and beam-flow angles. These errors were found to be consistent with our simulation results.

  1. Pulsed high intensity focused ultrasound increases penetration and therapeutic efficacy of monoclonal antibodies in murine xenograft tumors

    PubMed Central

    Wang, Shutao; Shin, In Soo; Hancock, Hilary; Jang, Beom-su; Kim, Hyung-sub; Lee, Sang Myung; Zderic, Vesna; Frenkel, Victor; Pastan, Ira; Paik, Chang H.; Dreher, Matthew R.

    2014-01-01

    The success of radioimmunotherapy for solid tumors remains elusive due to poor biodistribution and insufficient tumor accumulation, in part, due to the unique tumor microenvironment resulting in heterogeneous tumor antibody distribution. Pulsed high intensity focused ultrasound (pulsed-HIFU) has previously been shown to increase the accumulation of 111In labeled B3 antibody (recognizes Lewisy antigen). The objective of this study was to investigate the tumor penetration and therapeutic efficacy of pulsed-HIFU exposures combined with 90Y labeled B3 mAb in an A431 solid tumor model. The ability of pulsed-HIFU (1 MHz, spatial averaged temporal peak intensity = 2685 Wcm−2; pulse repetition frequency = 1 Hz; duty cycle = 5%) to improve the tumor penetration and therapeutic efficacy of 90Y labeled B3 mAb (90Y-B3) was evaluated in Ley-positive A431 tumors. Antibody penetration from the tumor surface and blood vessel surface was evaluated with fluorescently labeled B3, epi-fluorescent microscopy, and custom image analysis. Tumor size was monitored to determine treatment efficacy, indicated by survival, following various treatments with pulsed-HIFU and/or 90Y-B3. The pulsed-HIFU exposures did not affect the vascular parameters including microvascular density, vascular size, and vascular architecture; although 1.6-fold more antibody was delivered to the solid tumors when combined with pulsed-HIFU. The distribution and penetration of the antibodies were significantly improved (p-value < 0.05) when combined with pulsed-HIFU, only in the tumor periphery. Pretreatment with pulsed-HIFU significantly improved (p-value < 0.05) survival over control treatments. PMID:22732476

  2. Effects of varying duty cycle and pulse width on high-intensity focused ultrasound (HIFU)-induced transcranial thrombolysis.

    PubMed

    Hölscher, Thilo; Raman, Rema; Fisher, David J; Ahadi, Golnaz; Zadicario, Eyal; Voie, Arne

    2013-01-01

    The goal was to test the effects of various combinations of pulse widths (PW) and duty cycles (DC) on high-intensity focused ultrasound (HIFU)-induced sonothrombolysis efficacy using an in vitro flow model. An ExAblate™ 4000 HIFU headsystem (InSightec, Inc., Israel) was used. Artificial blood clots were placed into test tubes inside a human calvarium and exposed to pulsatile flow. Four different duty cycles were tested against four different pulse widths. For all study groups, an increase in thrombolysis efficacy could be seen in association with increasing DC and/or PW (p < 0.0001). Using transcranial HIFU, significant thrombolysis can be achieved within seconds and without the use of lytic drugs in vitro. Longer duty cycles in combination with longer pulse widths seem to have the highest potential to optimize clot lysis efficacy.

  3. Low Intensity TMS Enhances Perception of Visual Stimuli.

    PubMed

    Abrahamyan, Arman; Clifford, Colin W G; Arabzadeh, Ehsan; Harris, Justin A

    2015-01-01

    Transcranial magnetic stimulation (TMS) is a popular functional mapping tool in cognitive and sensory neuroscience. While strong TMS typically degrades performance, two recent studies have demonstrated that weak TMS, delivered to visual cortex, can improve performance on simple visual tasks. The improvement was interpreted as the summation of visually-evoked and TMS-elicited neuronal activity in visual cortex, but the nature of this interaction remains unclear. The present experiments sought to determine whether these weak pulses of TMS assist subjects to see the visual stimulus itself or create a distinct "melded" percept that may not be recognizable as the visual stimulus. We measured contrast thresholds in an orientation discrimination task in which participants reported the orientation (left or right) of gratings tilted 45° from vertical. Weak TMS improved sensitivity for identifying gratings, suggesting that TMS sums with but preserves orientation information so that the subject can recognize the visual stimulus. We explain the effect using a mechanism of non-linear transduction of sensory signals in the brain. The capability of low-intensity TMS to augment the neural signal while preserving information encoded in the stimulus can be employed as a novel approach to study the neural correlates of consciousness by selectively "pushing" an unconscious stimulus into consciousness. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Treatment of hepatic tumors by thermal versus mechanical effects of pulsed high intensity focused ultrasound in vivo

    NASA Astrophysics Data System (ADS)

    Peng, Song; Zhou, Ping; He, Wei; Liao, Manqiong; Chen, Lili; Ma, C.-M.

    2016-09-01

    The purpose of this study is to comparatively assess the thermal versus mechanical effects of pulsed high intensity focused ultrasound (HIFU) treatment on hepatic tumors in vivo. Forty-five rabbits with hepatic VX2 tumors were randomly separated into three groups (15 animals per group) before HIFU ablation. The total HIFU energy (in situ) of 1250 J was used for each tumor for three groups. In groups I and II, animals were treated with 1 MHz pulsed ultrasound at 1 Hz pulsed repetition frequency (PRF), 0.5 duty cycle (0.5 s on and 0.5 s off) and10 s duration for one spot sonication. For group II, in addition to HIFU treatment, microbubbles (SonoVue, Bracco, Milan, Italy) were injected via vein before sonication acting as a synergist. In group III, animals were treated with 1 MHz pulsed ultrasound at 10 Hz PRF, 0.1 duty cycle (0.1 s on and 0.9 s off) and 10 s duration for one sonication. The total treatment spots were calculated according to the tumor volume. Tumors were examined with contrast-enhanced computed tomography (CECT) immediately prior to and post HIFU treatment. Histopathologic assessment was performed 3 h after treatment. Our study showed that all animals tolerated the HIFU treatment well. Our data showed that mechanical HIFU could lead to controlled injury in rabbit hepatic tumors with different histological changes in comparison to thermal HIFU with or without microbubbles.

  5. Flow rate and duty cycle effects in lysis of Chlamydomonas reinhardtii using high-energy pulsed focused ultrasound.

    PubMed

    Riesberg, Grant; Bigelow, Timothy A; Stessman, Dan J; Spalding, Martin H; Yao, Linxing; Wang, Tong; Xu, Jin

    2014-06-01

    To consider microalgae lipid biofuel as a viable energy source, it is a necessity to maximize algal cell lysis, lipid harvest, and thus biofuel production versus the energy used to lyse the cells. Previous techniques have been to use energy consumptive ultrasound waves in the 10-40 kHz range in a stationary exposure environment. This study evaluated the potential of using 1.1 MHz ultrasound pulses in a new flow through type chamber on Chlamydomonas reinhardtii as a model organism for cell breakage. The ultrasound was generated using a spherically focused transducer with a focal length of 6.34 cm and an active diameter of 6.36 cm driven by 20 cycle sine-wave tone bursts at varied pulse repetition frequencies. First, variations in flow rate were examined at a constant duty cycle of 3.6%. After assessing flow rates, the duty cycle was varied to further explore the dependence on the tone burst parameters. Cell lysis was assessed by quantifying protein and chlorophyll release into the supernatant as well as by lipid extractability. Appropriate flow rates with higher duty cycles led to statistically significant increases in cell lysis relative to controls and other exposure conditions.

  6. Why Current Doppler Ultrasound Methodology Is Inaccurate in Assessing Cerebral Venous Return: The Alternative of the Ultrasonic Jugular Venous Pulse

    PubMed Central

    2016-01-01

    Assessment of cerebral venous return is growing interest for potential application in clinical practice. Doppler ultrasound (DUS) was used as a screening tool. However, three meta-analyses of qualitative DUS protocol demonstrate a big heterogeneity among studies. In an attempt to improve accuracy, several authors alternatively measured the flow rate, based on the product of the time average velocity with the cross-sectional area (CSA). However, also the quantification protocols lacked of the necessary accuracy. The reasons are as follows: (a) automatic measurement of the CSA assimilates the jugular to a circle, while it is elliptical; (b) the use of just a single CSA value in a pulsatile vessel is inaccurate; (c) time average velocity assessment can be applied only in laminar flow. Finally, the tutorial describes alternative ultrasound calculation of flow based on the Womersley method, which takes into account the variation of the jugular CSA overtime. In the near future, it will be possible to synchronize the electrocardiogram with the brain inflow (carotid distension wave) and with the outflow (jugular venous pulse) in order to nicely have a noninvasive ultrasound picture of the brain-heart axis. US jugular venous pulse may have potential use in neurovascular, neurocognitive, neurosensorial, and neurodegenerative disorders. PMID:27006525

  7. An ultrasound automated method for non-invasive assessment of carotid artery pulse wave velocity.

    PubMed

    Zardi, Enrico Maria; Di Geso, Luca; Afeltra, Antonella; Zardi, Domenico Maria; Giorgi, Chiara; Salaffi, Fausto; Carotti, Marina; Gutierrez, Marwin; Filippucci, Emilio; Grassi, Walter

    2017-09-02

    To validate the clinical applicability and feasibility of an automated ultrasound (US) method in measuring the arterial stiffness of patients with chronic inflammatory rheumatic diseases, comparing automated measurements performed by a rheumatologist without experience in vascular sonography with those obtained by a sonographer experienced in vascular US, using a standardized manual method.Twenty subjects affected by different chronic inflammatory rheumatic disorders were consecutively recruited. For each patient, the arterial stiffness of both common carotids was manually calculated. Subsequently, the measure of the pulse wave velocity (PWV) was obtained using an US device called Radio Frequency - Quality Arterial Stiffness (RF-QAS), provided by the same US system (ie, My Lab 70 XVG, Esaote SpA, Genoa, Italy) equipped with a 4-13 MHz linear probe. The reliability comparison between the two US methods was calculated using the intraclass correlation coefficient (ICC). ICC between the values obtained with the two methods for calculating the arterial stiffness resulted 0.789. A significant positive correlation between the two methods was also established with Pearson's (r=0.62, p<0.0001) and Spearman's analysis (r=0.66, p=0.001). A significant performance comparison was seen using Bland-Altman plot. The acquisition of the arterial stiffness parameter with the automated method required about 2 min for each patient. Clinical applicability of this US automated method to assess PWV at common carotid level by a rheumatologist is reliable and feasible in comparison with a conventional manual method. © American Federation for Medical Research (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Assessment of aortic pulse wave velocity by ultrasound: a feasibility study in mice

    NASA Astrophysics Data System (ADS)

    Faita, Francesco; Di Lascio, Nicole; Stea, Francesco; Kusmic, Claudia; Sicari, Rosa

    2014-03-01

    Pulse wave velocity (PWV) is considered a surrogate marker of arterial stiffness and could be useful for characterizing cardiovascular disease progression even in mouse models. Aim of this study was to develop an image process algorithm for assessing arterial PWV in mice using ultrasound (US) images only and test it on the evaluation of age-associated differences in abdominal aorta PWV (aaPWV). US scans were obtained from six adult (7 months) and six old (19 months) wild type male mice (strain C57BL6) under gaseous anaesthesia. For each mouse, diameter and flow velocity instantaneous values were achieved from abdominal aorta B-mode and PW-Doppler images; all measurements were obtained using edge detection and contour tracking techniques. Single-beat mean diameter and velocity were calculated and time-aligned, providing the lnD-V loop. aaPWV values were obtained from the slope of the linear part of the loop (the early systolic phase), while relative distension (relD) measurements were calculated from the mean diameter signal. aaPWV values for young mice (3.5±0.52 m/s) were lower than those obtained for older ones (5.12±0.98 m/s) while relD measurements were higher in young (25%±7%) compared with older animals evaluations (15%±3%). All measurements were significantly different between the two groups (P<0.01 both). In conclusion, the proposed image processing technique well discriminate between age groups. Since it provides PWV assessment just from US images, it could represent a simply and useful system for vascular stiffness evaluation at any arterial site in the mouse, even in preclinical small animal models.

  9. Detection of tissue harmonic motion induced by ultrasonic radiation force using pulse-echo ultrasound and Kalman filter.

    PubMed

    Zheng, Yi; Chen, Shigao; Tan, Wei; Kinnick, Randall; Greenleaf, James F

    2007-02-01

    A method using pulse echo ultrasound and the Kalman filter is developed for detecting submicron harmonic motion induced by ultrasonic radiation force. The method estimates the amplitude and phase of the motion at desired locations within a tissue region with high sensitivity. The harmonic motion generated by the ultrasound radiation force is expressed as extremely small oscillatory Doppler frequency shifts in the fast time (A-line) of ultrasound echoes, which are difficult to estimate. In slow time (repetitive ultrasound echoes) of the echoes, the motion also is presented as oscillatory phase shifts, from which the amplitude and phase of the harmonic motion can be estimated with the least mean squared error by Kalman filter. This technique can be used to estimate the traveling speed of a harmonic shear wave by tracking its phase changes during propagation. The shear wave propagation speed can be used to solve for the elasticity and viscosity of tissue as reported in our earlier study. Validation and in vitro experiments indicate that the method provides excellent estimations for very small (submicron) harmonic vibrations and has potential for noninvasive and quantitative stiffness measurements of tissues such as artery.

  10. Low-intensity, stocker-based channel catfish culture

    USDA-ARS?s Scientific Manuscript database

    Low-intensity Channel Catfish production is characterized by low stocking rates, low installed aeration capacity, and no automated dissolved oxygen monitoring. Two studies conducted in nine 0.25-acre ponds quantified production characteristics of stocker Channel Catfish stocked for low-intensity foo...

  11. A 3D time reversal cavity for the focusing of high-intensity ultrasound pulses over a large volume

    NASA Astrophysics Data System (ADS)

    Robin, J.; Arnal, B.; Tanter, M.; Pernot, M.

    2017-02-01

    Shock wave ultrasound therapy techniques, increasingly used for non-invasive surgery, require extremely high pressure amplitudes in precise focal spots, and large high-power transducers arranged on a spherical shell are usually used to achieve that. This solution allows limited steering of the beam around the geometrical focus of the device at the cost of a large number of transducer elements, and the treatment of large and moving organs like the heart is challenging or impossible. This paper validates numerically and experimentally the possibility of using a time reversal cavity (TRC) for the same purpose. A 128-element, 1 MHz power transducer combined with different multiple scattering media in a TRC was used. We were able to focus high-power ultrasound pulses over a large volume in a controlled manner, with a limited number of transducer elements. We reached sufficiently high pressure amplitudes to erode an Ultracal® target over a 10 cm2 area.

  12. Low-Power 2-MHz Pulsed-Wave Transcranial Ultrasound Reduces Ischemic Brain Damage in Rats.

    PubMed

    Alexandrov, Andrei V; Barlinn, Kristian; Strong, Roger; Alexandrov, Anne W; Aronowski, Jaroslaw

    2011-09-01

    It is largely unknown whether prolonged insonation with ultrasound impacts the ischemic brain tissue by itself. Our goal was to evaluate safety and the effect of high-frequency ultrasound on infarct volume in rats. Thirty-two Long-Evans rats with permanent middle cerebral and carotid artery occlusions received either 2-MHz ultrasound at two levels of insonation power (128 or 10 mW) or no ultrasound (controls). We measured cerebral hemorrhage, indirect and direct infarct volume as well as edema volume at 24 h. No cerebral hemorrhages were detected in all animals. Exposure to low-power (10 mW) ultrasound resulted in a significantly decreased indirect infarct volume (p = 0.0039), direct infarct volume (p = 0.0031), and brain edema volume (p = 0.01) compared with controls. High-power (128 mW) ultrasound had no significant effects. An additional experiment with India ink showed a greater intravascular penetration of dye into ischemic tissues exposed to low-power ultrasound. Insonation with high-frequency, low-power ultrasound reduces ischemic brain damage in rat. Its effect on edema reduction and possible promotion of microcirculation could be used to facilitate drug and nutrient delivery to ischemic areas.

  13. Treatment of meralgia paresthetica with ultrasound-guided pulsed radiofrequency ablation of the lateral femoral cutaneous nerve.

    PubMed

    Fowler, Ian M; Tucker, Anthony A; Mendez, Robert J

    2012-06-01

    A 23-year-old female with an 18-month history of left anterolateral thigh paresthesias and burning pain consistent with meralgia paresthetica was referred to our clinic after failing trials of physical therapy, nonsteroidal anti-inflammatories, gabapentin, and amitriptyline. We performed 3 lateral femoral cutaneous nerve blocks with corticosteroid over a 4-month period; however, each block provided only temporary relief. As this pain was limiting the patient's ability to perform her functions as an active duty service member, we elected to perform a pulsed radiofrequency treatment of the lateral femoral cutaneous nerve with ultrasound guidance and nerve stimulation. After locating the lateral femoral cutaneous nerve with ultrasound and reproducing the patient's dysthesia with stimulation, pulsed radiofrequency treatment was performed at 42°C for 120 seconds. The needle was then rotated 180° and an additional cycle of pulsed radiofrequency treatment was performed followed by injection of 0.25% ropivacaine with 4 mg of dexamethasone. At 1.5 and 3 month follow-up visits, the patient reported excellent pain relief with activity and improved ability to perform her duties as an active duty service member. ▪ Published 2011. This article is a U.S. Government work and is in the public domain in the USA. Pain Practice © 2011 World Institute of Pain.

  14. The combination of pulsed acousto-optic imaging and B-mode diagnostic ultrasound for three-dimensional imaging in ex vivo biological tissue

    NASA Astrophysics Data System (ADS)

    Sui, Lei; Murray, Todd W.; Roy, Ronald A.

    2006-02-01

    A multimode imaging system, producing conventional ultrasound (US) and acousto-optic (AO) images, has been developed and used to detect optical absorbers buried in excised biological tissue. A commercially-available diagnostic ultrasound imaging transducer is used to both generate B-mode ultrasound images and as a pump for AO imaging. Due to the fact that the steered and focused beam used for US imaging and the US source for pumping the AO image are generated from the same ultrasound probe, the acoustical and optical images are intrinsically co-registered. AO imaging is performed using short ultrasound pulse trains at a frequency of 5 MHz. The phase-modulated light emitted from the interaction region is detected using a photorefractive-crystal based interferometry system. Experimental results have previously been presented for the two-dimensional imaging in tissue-mimicking phantoms. In this paper, we report further experimental developments demonstrating three-dimensional fusion of B-mode ultrasound imaging and pulsed acousto-optic imaging in excised biological tissue (~2 cm thick). By mechanically scanning the ultrasound transducer array in a direction perpendicular to its imaging plane, both the acoustical and optical properties of an embedded target are obtained in three dimensions. The results suggest that AO imaging could be used to supplement conventional B-mode ultrasound imaging with optical contrast, and the multimode imaging system may find application in the detection and diagnosis of cancer.

  15. Ultrasound-Guided Pulsed Radiofrequency Application via the Pterygopalatine Fossa: A Practical Approach to Treat Refractory Trigeminal Neuralgia.

    PubMed

    Nader, Antoun; Bendok, Bernard R; Prine, Jeremy J; Kendall, Mark C

    2015-01-01

    Although pharmacological therapy is the primary treatment modality for trigeminal neuralgia associated pain, ineffective analgesia and dose limiting side effects often prompt patients to seek alternative pharmacological solutions such as interventional nerve blockade. Blockade of the Gasserian ganglion or its branches is an effective analgesic procedure for trigeminal neuralgia, traditionally performed using fluoroscopy or CT imaging. Ultrasonography allows point of care and real time visualization of needle placement within the surrounding anatomical structures. The use of ultrasonography with pulsed radiofrequency therapy for trigeminal neuralgia has not been reported. Our case is a 66-year-old male suffering from trigeminal neuralgia for 4 years that was refractory to pharmacologic therapy. Neurological examination was normal with no sensory deficit. Imaging showed no vascular compression or mass involving the trigeminal nerve. A diagnostic ultrasound-guided trigeminal nerve block via the pterygopalatine fossa with 4 mL of bupivacaine 0.25% and 4 mg dexamethasone provided immediate pain relief (100%) with sustained analgesia >50% at 2 weeks. Pain relief was not sustained at one month, with return to pretreatment symptoms. A series of injections were performed with similar intermittent analgesic effectiveness. The decision was made that the patient was a suitable candidate for pulsed radiofrequency application in the pterygopalatine fossa. We successfully used an alternative approach through the pterygopalatine fossa to treat trigeminal neuralgia using ultrasound guidance in an office setting. Our case demonstrates the utility of ultrasound-guidance pulsed radiofrequency treatment in the pterygopalatine fossa as a potential alternative to other percutaneous techniques for patients with medical refractory trigeminal neuralgia.

  16. Comparison of the Effects of Ultrasound-Guided Interfascial Pulsed Radiofrequency and Ultrasound-Guided Interfascial Injection on Myofascial Pain Syndrome of the Gastrocnemius.

    PubMed

    Park, So Min; Cho, Yun Woo; Ahn, Sang Ho; Lee, Dong Gyu; Cho, Hee Kyung; Kim, Sung Yup

    2016-10-01

    To investigate the comparative treatment effects of ultrasound-guided pulsed radiofrequency treatment (UG-PRF) in the gastrocnemius interfascial space and ultrasound-guided interfascial injection (UG-INJ) on myofascial pain syndrome. Forty consecutive patients with myofascial pain syndrome of the gastrocnemius were enrolled and were allocated to one of the two groups. Twenty patients were treated by UG-PRF delivered to the gastrocnemius interfascial space (UG-PRF group) and the other 20 patients were treated by interfascial injection (UG-INJ group). The primary outcome measure was the numeric rating score (NRS) for pain on pressing the tender point in the gastrocnemius, and the secondary outcome measure was health-related quality of life as determined by the Short Form-36 questionnaire (SF-36). NRSs were obtained at the first visit, immediately after treatment, and at 2 and 4 weeks post-treatment, and physical component summary scores (PCS) and mental component summary scores (MCS) of the SF-36 questionnaire were measured at the first visit and at 4 weeks post-treatment. Immediately after treatments, mean NRS in the UG-PRF group was significantly higher than that in the UG-INJ group (p<0.0001). However, at 2 and 4 weeks post-treatment, the mean NRS was significantly lower in the UG-PRF group (both p<0.0001). Similarly, at 4 weeks post-treatment, mean PCS and MCS were significantly higher in the UG-PRF group (p<0.0001 and p=0.002, respectively). Based on these results, the authors conclude that ultrasound-guided gastrocnemius interfascial PRF provides an attractive treatment for myofascial pain syndrome of the gastrocnemius.

  17. Comparison of the Effects of Ultrasound-Guided Interfascial Pulsed Radiofrequency and Ultrasound-Guided Interfascial Injection on Myofascial Pain Syndrome of the Gastrocnemius

    PubMed Central

    2016-01-01

    Objective To investigate the comparative treatment effects of ultrasound-guided pulsed radiofrequency treatment (UG-PRF) in the gastrocnemius interfascial space and ultrasound-guided interfascial injection (UG-INJ) on myofascial pain syndrome. Methods Forty consecutive patients with myofascial pain syndrome of the gastrocnemius were enrolled and were allocated to one of the two groups. Twenty patients were treated by UG-PRF delivered to the gastrocnemius interfascial space (UG-PRF group) and the other 20 patients were treated by interfascial injection (UG-INJ group). The primary outcome measure was the numeric rating score (NRS) for pain on pressing the tender point in the gastrocnemius, and the secondary outcome measure was health-related quality of life as determined by the Short Form-36 questionnaire (SF-36). NRSs were obtained at the first visit, immediately after treatment, and at 2 and 4 weeks post-treatment, and physical component summary scores (PCS) and mental component summary scores (MCS) of the SF-36 questionnaire were measured at the first visit and at 4 weeks post-treatment. Results Immediately after treatments, mean NRS in the UG-PRF group was significantly higher than that in the UG-INJ group (p<0.0001). However, at 2 and 4 weeks post-treatment, the mean NRS was significantly lower in the UG-PRF group (both p<0.0001). Similarly, at 4 weeks post-treatment, mean PCS and MCS were significantly higher in the UG-PRF group (p<0.0001 and p=0.002, respectively). Conclusion Based on these results, the authors conclude that ultrasound-guided gastrocnemius interfascial PRF provides an attractive treatment for myofascial pain syndrome of the gastrocnemius. PMID:27847719

  18. Bio-effects and safety of low-intensity, low-frequency ultrasonic exposure.

    PubMed

    Ahmadi, Farzaneh; McLoughlin, Ian V; Chauhan, Sunita; ter-Haar, Gail

    2012-04-01

    Low-frequency (LF) ultrasound (20-100 kHz) has a diverse set of industrial and medical applications. In fact, high power industrial applications of ultrasound mainly occupy this frequency range. This range is also used for various therapeutic medical applications including sonophoresis (ultrasonic transdermal drug delivery), dentistry, eye surgery, body contouring, the breaking of kidney stones and eliminating blood clots. While emerging LF applications such as ultrasonic drug delivery continue to be developed and undergo translation for human use, significant gaps exist in the coverage of safety standards for this frequency range. Accordingly, the need to understand the biological effects of LF ultrasound is becoming more important. This paper presents a broad overview of bio-effects and safety of LF ultrasound as an aid to minimize and control the risk of these effects. Its particular focus is at low intensities where bio-effects are initially observed. To generate a clear perspective of hazards in LF exposure, the mechanisms of bio-effects and the main differences in action at low and high frequencies are investigated and a survey of harmful effects of LF ultrasound at low intensities is presented. Mechanical and thermal indices are widely used in high frequency diagnostic applications as a means of indicating safety of ultrasonic exposure. The direct application of these indices at low frequencies needs careful investigation. In this work, using numerical simulations based on the mathematical and physical rationale behind the indices at high frequencies, it is observed that while thermal index (TI) can be used directly in the LF range, mechanical index (MI) seems to become less reliable at lower frequencies. Accordingly, an improved formulation for the MI is proposed for frequencies below 500 kHz.

  19. The Role of Military Working Dogs in Low Intensity Conflict

    DTIC Science & Technology

    1990-02-01

    lJji•;1 FILE COUY" ’ AD-A224 049 -7CLIC PAPERS THE ROLE OF MILITARY WORKING DOGS IN LOW INTENSITY CONFLICT*,. ’< " Army. Air Force Center for Low...Intensity Conflict Langley Air Force Base, Virginia (O I7 16 235’ REPORT DOCUMENTATIOJN PA~GE 30a’ 1 IOTSICUtiTY CLASS CAt " lb RIESTRI(TIVE VAWG o...TITLE (include Security Claw ifirctiofl) The Role of Military Working Dogs in Low Intensity Conflict 12. PERSONAL AUTHOR(S) LTC William H. Thornton

  20. MR-Guided Pulsed High-Intensity Focused Ultrasound Enhancement of Gene Therapy Combined With Androgen Deprivation and Radiotherapy for Prostate Cancer Treatment

    DTIC Science & Technology

    2009-09-01

    ultrasound . J. Acoust. Soc.Am. 72 1926-1932, (1982) (7) Neppiras E A. Acoustic cavitation . Physics reports 61(3): 159-251, (1980) (8) ter Haar G R, Daniels...Guided Pulsed High-Intensity Focused Ultrasound Enhancement of 5b. GRANT NUMBER W81XWH-08-1-0469 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...failing to This work is aimed to study MR guided high intensity focused ultrasound (MRgHIFU) enhancement of gene therapy for Prostate Cancer. The

  1. Ultrasound and electric pulses for transdermal drug delivery enhancement: Ex vivo assessment of methods with in vivo oriented experimental protocols.

    PubMed

    Zorec, Barbara; Jelenc, Jure; Miklavčič, Damijan; Pavšelj, Nataša

    2015-07-25

    In our present study we focus on two physical enhancement methods for transdermal drug delivery: ultrasound and electric pulses either alone or in combination. Great emphasis has been given on the design of the experimental system and protocols, so the results and the conclusions drawn from them would have greater relevance for in vivo use and later translation into clinical practice. Our results show a statistically significant enhancement of calcein delivery (after one hour of passive diffusion following treatment) already after 5 minutes of ultrasound application, or only 6 × 100 short high voltage electrical pulses. We also experimented with combinations of the two enhancement methods hoping for synergistic effects, however, the results showed no evident drastic improvement over single method. Looking closer at physics of both methods, this absence of synergy in our in vivo oriented experimental setting is not surprising. The mechanism of action of both methods is the creation of aqueous pathways in the stratum corneum leading to increased skin permeability. However, when used in combination (regardless of the order of methods), the second method was unsuccessful in adding many new aqueous pathways in the stratum corneum, as it acted preferentially near the sites of the existing ones.

  2. Horse-Mounted Troops in Low Intensity Conflict

    DTIC Science & Technology

    1991-06-01

    agency. HORSE -MOUNTED TROOPS IN LOW INTENSITY CONFLICT BY Lieutenant Colonel Peter W. J. Onoszko, IN Senior Service College Fellow Tufts University...COMPLETING FORM i. REPORT NUMBER 2. GOVT ACCESSION NO. 3. RECIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Horse ...Mounted Troops in Low Intensity Conflict Individual Study Project An argument for the development of a horse -mounted_ capability within United States

  3. A randomized, double-blind clinical trial comparing the effects of continuous and pulsed ultrasound in patients with chronic rhinosinusitis.

    PubMed

    Ansari, Noureddin Nakhostin; Fathali, Mojtaba; Naghdi, Soofia; Hasson, Scott; Jalaie, Shohreh; Rastak, Mohammad Saeed

    2012-02-01

    The objective of the present study was to compare the effects of continuous ultrasound (CUS) with pulsed ultrasound (PUS) in patients with chronic rhinosinusitis (CRS). In this prospective, randomized, double-blind, parallel group study, 40 patients (10 losses) with CRS participated. Patients received either continuous or pulsed (1:9) 1 MHz ultrasound (US) using a US head of 1 cm2 at 1 W/cm2 and 0.5 W/cm2 for the maxillary and frontal sinuses, respectively. Treatment was performed in 10 sessions, 3 days per week, with US given every other day. The primary outcome measure was percent improvement in the Sinusitis Symptom Score. Measurements were taken before and after 10 treatment sessions. The patients were followed up monthly for 2 months. After treatment, both groups improved significantly on the Sinusitis Symptoms Score. Patients who received PUS had significantly decreased total symptom scores compared with patients receiving CUS (mean change 9.8 vs. 5.6, p = 0.049). The percent improvement in the Sinusitis Symptom Score between the PUS group (65.2 SD 23.1) and the CUS group (43.9 SD 40.7) was not statistically significant (p = 0.09). The effect size for each treatment was large; PUS: d = 3.92 and CUS: d = 1.93. Symptom improvement in both groups was similar at the 2-month follow-up. These results support the use of therapeutic US for CRS. This pilot study gives only marginal evidence to favor PUS over CUS.

  4. Simultaneous Real-time Monitoring of Thermal and Mechanical Tissue Responses to Pulsed HIFU Using Pulse-Echo Ultrasound

    NASA Astrophysics Data System (ADS)

    Liu, Dalong; Ebbini, Emad S.

    2009-04-01

    Pulsed HIFU beams are being increasingly used in a number of therapeutic applications, including thermal therapy, drug and gene delivery, and hemostasis. This wide range of applications is based on a range of HIFU-tissue interactions from purely thermal to purely mechanical to produce the desired therapeutic effects. We have developed a real-time system for monitoring tissue displacements in response to pulsed HIFU beams at high PRFs. The imaging component of the system comprises an FPGA-based signal processing unit for real-time filtering of M-mode pulse-echo data followed by real-time speckle tracking for tissue displacements before, during, and after exposure to pulsed HIFU. The latter can be used in evaluating temperature and/or viscoelastic response to the applied HIFU beam. The high acquisition rate of the M-mode system, together with the real-time displacement tracking are necessary for simultaneous estimation and separation of the thermal and viscoelastic tissue responses. In addition, the system provides a real-time link to MATLAB-based nonlinear spectral estimation routines for cavitation detection. The system has been tested in vitro bovine heart tissue and the results show that the displacement tracking captures the full dynamics of tissue displacements for the full range of HIFU exposures of interest.

  5. Pulsed magnetic field versus ultrasound in the treatment of postnatal carpal tunnel syndrome: A randomized controlled trial in the women of an Egyptian population.

    PubMed

    Kamel, Dalia M; Hamed, Nashwa S; Abdel Raoof, Neveen A; Tantawy, Sayed A

    2017-01-01

    The aim of this study was to compare the effects of pulsed electromagnetic field versus pulsed ultrasound in treating patients with postnatal carpal tunnel syndrome. The study was a randomized, double-blinded trial. Forty postnatal female patients with idiopathic carpal tunnel syndrome were divided randomly into two equal groups. One group received pulsed electromagnetic field, with nerve and tendon gliding exercises for the wrist, three times per week for four weeks. The other group received pulsed ultrasound and the same wrist exercises. Pain level, sensory and motor distal latencies and conduction velocities of the median nerve, functional status scale and hand grip strength were assessed pre- and post-treatment. There was a significant decrease (P < 0.05) in pain level, sensory and motor distal latencies of the median nerve, and significant increase (P < 0.05) in sensory and motor conduction velocities of the median nerve and hand grip strength in both groups, with a significant difference between the two groups in favour of pulsed electromagnetic field treatment. However, the functional status scale showed intergroup no significant difference (P > 0.05). In conclusion, while the symptoms were alleviated in both groups, pulsed electromagnetic field was more effective than pulsed ultrasound in treating postnatal carpal tunnel syndrome.

  6. Unmyelinated Peripheral Nerves Can Be Stimulated in Vitro Using Pulsed Ultrasound.

    PubMed

    Wright, Christopher J; Haqshenas, Seyyed R; Rothwell, John; Saffari, Nader

    2017-10-01

    Appreciation for the medical and research potential of ultrasound neuromodulation is growing rapidly, with potential applications in non-invasive treatment of neurodegenerative disease and functional brain mapping spurring recent progress. However, little progress has been made in our understanding of the ultrasound-tissue interaction. The current study tackles this issue by measuring compound action potentials (CAPs) from an ex vivo crab walking leg nerve bundle and analysing the acoustic nature of successful stimuli using a passive cavitation detector (PCD). An unimpeded ultrasound path, new acoustic analysis techniques and simple biological targets are used to detect different modes of cavitation and narrow down the candidate biological effectors with high sensitivity. In the present case, the constituents of unmyelinated axonal tissue alone are found to be sufficient to generate de novo action potentials under ultrasound, the stimulation of which is significantly correlated to the presence of inertial cavitation and is never observed in its absence. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  7. PULSED FOCUSED ULTRASOUND TREATMENT OF MUSCLE MITIGATES PARALYSIS-INDUCED BONE LOSS IN THE ADJACENT BONE: A STUDY IN A MOUSE MODEL

    PubMed Central

    Poliachik, Sandra L.; Khokhlova, Tatiana D.; Wang, Yak-Nam; Simon, Julianna C.; Bailey, Michael R.

    2015-01-01

    Bone loss can result from bed rest, space flight, spinal cord injury or age-related hormonal changes. Current bone loss mitigation techniques include pharmaceutical interventions, exercise, pulsed ultrasound targeted to bone and whole body vibration. In this study, we attempted to mitigate paralysis-induced bone loss by applying focused ultrasound to the midbelly of a paralyzed muscle. We employed a mouse model of disuse that uses onabotulinumtoxinA-induced paralysis, which causes rapid bone loss in 5 d. A focused 2 MHz transducer applied pulsed exposures with pulse repetition frequency mimicking that of motor neuron firing during walking (80 Hz), standing (20 Hz), or the standard pulsed ultrasound frequency used in fracture healing (1 kHz). Exposures were applied daily to calf muscle for 4 consecutive d. Trabecular bone changes were characterized using micro-computed tomography. Our results indicated that application of certain focused pulsed ultrasound parameters was able to mitigate some of the paralysis-induced bone loss. PMID:24857416

  8. Continuous and pulsed ultrasound-assisted extractions of antioxidants from pomegranate peel

    USDA-ARS?s Scientific Manuscript database

    There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from dry peel of pomegranate marc were studied using ultrasound assis...

  9. Continuous and pulsed ultrasound-assisted extractions of antioxidants from pomegranate peel

    USDA-ARS?s Scientific Manuscript database

    There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from dry peel of pomegranate marc were studied using ultrasound-assis...

  10. Enhancement of Small Molecule Delivery by Pulsed-High Intensity Focused Ultrasound (pHIFU): A Parameter Exploration

    PubMed Central

    Zhou, Yufeng; Wang, Yak-Nam; Farr, Navid; Zia, Jasmine; Chen, Hong; Ko, Bong Min; Khokhlova, Tatiana; Li, Tong; Hwang, Joo Ha

    2015-01-01

    Chemotherapeutic drug delivery is often ineffective within solid tumors, but increasing the drug dose would result in systemic toxicity. The use of high-intensity focused ultrasound (HIFU) has the potential to enhance penetration of small molecules. However, operation parameters need to be optimized before the use of chemotherapeutic drug in vivo and translation to clinical trial. In this study, the effects of pulsed-HIFU (pHIFU) parameters (spatial-average pulse-average intensity, duty factor, and pulse repetition frequency) to the penetration as well as content of small molecules were evaluated in ex vivo porcine kidneys. Specific HIFU parameters resulted in over 40 times greater Evans blue content and 3.5 times the penetration depth compared to untreated samples. When selected parameters were applied to porcine kidneys in vivo, a 2.3-fold increase in concentration was obtained after a 2-minute pHIFU exposure. Altogether, pHIFU has shown to be an effective modality to enhance both the concentration and penetration depth of small molecules into tissue using the optimized HIFU parameters. Although, performed in normal tissue, this study has the promise of translation into tumor tissue. PMID:26803389

  11. A two-pulse technique for extracting 3rd harmonic from ultrasound contrast agent echo signal.

    PubMed

    Song, Jae-hee; Kim, Sang-min; Song, Tai-kyong

    2008-01-01

    Multi-pulse techniques like CPS (contrast pulse sequence) and TPS (triplet pulse sequence) are the most popular methods for separating the 3rd harmonic signals from received signal. Those two methods, however, transmit a pulse at least three times along each scanline with different phase and amplitude, which results in the frame rate reduction. In this paper, we propose a technique using two pulses whose phase difference is 90 degrees and a simple digital filter. The second harmonic signal is eliminated by summing two received signals as their phase difference becomes 180 degrees and then the fundamental signals are eliminated by using a digital filter. Computer simulations are performed for different values of signal bandwidths and filter specifications. The results show the maximum error is -35.5 dB compared to TPS.

  12. Management of pudendal neuralgia using ultrasound-guided pulsed radiofrequency: a report of two cases and discussion of pudendal nerve block techniques.

    PubMed

    Hong, Myong-Joo; Kim, Yeon-Dong; Park, Jeong-Ki; Hong, Hyon-Joo

    2016-04-01

    Pudendal neuralgia is characterized by chronic pain or discomfort in the area innervated by the pudendal nerve, with no obvious cause. A successful pudendal nerve block is crucial for the diagnosis of pudendal neuralgia. Blind or fluoroscopy-guided pudendal nerve blocks have been conventionally used for diagnosis and treatment; however, ultrasound-guided pudendal nerve blocks were also reported recently. With regard to the achievement of long-term effects, although pulsed radiofrequency performed under fluoroscopic guidance has been reported, that performed under ultrasound guidance is not well reported. This report describes two cases of pudendal neuralgia that were successfully managed using ultrasound-guided pulsed radiofrequency and presents a literature review of pudendal nerve block techniques. However, in the management of chronic neuropathic pain, physicians should keep in mind that the placebo effect related to invasive approaches must not be neglected.

  13. Low-intensity resistance training after high-intensity resistance training can prevent the increase of central arterial stiffness.

    PubMed

    Okamoto, T; Masuhara, M; Ikuta, K

    2013-05-01

    Although high-intensity resistance training increases arterial stiffness, low-intensity resistance training reduces arterial stiffness. The present study investigates the effect of low-intensity resistance training before and after high-intensity resistance training on arterial stiffness. 30 young healthy subjects were randomly assigned to a group that performed low-intensity resistance training before high-intensity resistance training (BLRT, n=10), a group that performed low-intensity resistance training after high-intensity resistance training (ALRT, n=10) and a sedentary control group (n=10). The BLRT and ALRT groups performed resistance training at 80% and 50% of one repetition maximum twice each week for 10 wk. Arterial stiffness was measured using carotid-femoral and femoral-ankle pulse wave velocity (PWV). One-repetition maximum strength in the both ALRT and BLRT significantly increased after the intervention (P<0.05 to P<0.01). Both carotid-femoral PWV and femoral-ankle PWV after combined training in the ALRT group did not change from before training. In contrast, carotid-femoral PWV after combined training in the BLRT group increased from before training (P <0.05). Femoral-ankle PWV after combined training in the both BLRT and ALRT groups did not change from before training. These results suggest that although arterial stiffness is increased by low-intensity resistance training before high-intensity resistance training, performing low-intensity resistance training thereafter can prevent the increase of arterial stiffness.

  14. Directivity patterns and pulse profiles of ultrasound emitted by laser action on interface between transparent and opaque solids: Analytical theory

    SciTech Connect

    Nikitin, Sergey M. E-mail: vitali.goussev@univ-lemans.fr; Tournat, Vincent; Chigarev, Nikolay; Castagnede, Bernard; Gusev, Vitalyi E-mail: vitali.goussev@univ-lemans.fr; Bulou, Alain; Zerr, Andreas

    2014-01-28

    The analytical theory for the directivity patterns of ultrasounds emitted from laser-irradiated interface between two isotropic solids is developed. It is valid for arbitrary combinations of transparent and opaque materials. The directivity patterns are derived both in two-dimensional and in three-dimensional geometries, by accounting for the specific features of the sound generation by the photo-induced mechanical stresses distributed in the volume, essential in the laser ultrasonics. In particular, the theory accounts for the contribution to the emitted propagating acoustic fields from the converted by the interface evanescent photo-generated compression-dilatation waves. The precise analytical solutions for the profiles of longitudinal and shear acoustic pulses emitted in different directions are proposed. The developed theory can be applied for dimensional scaling, optimization, and interpretation of the high-pressure laser ultrasonics experiments in diamond anvil cell.

  15. Accuracy of velocity and shear rate measurements using pulsed Doppler ultrasound: a comparison of signal analysis techniques.

    PubMed

    Markou, C P; Ku, D N

    1991-01-01

    An experimental investigation was instituted to evaluate the performance of Doppler ultrasound signal processing techniques for measuring fluid velocity under well-defined flow conditions using a 10-MHz multigated pulsed ultrasound instrument. Conditions of fully developed flow in a rigid, circular tube were varied over a Reynolds number range between 500 and 8000. The velocity across the tube was determined using analog and digital zero crossing detectors and three digital spectrum estimators. Determination of the Doppler frequency from analog or digital zero crossing detectors gave accurate velocity values for laminar and moderately turbulent flow away from the wall (0.969 less than or equal to r less than or equal to 0.986). Three digital spectrum estimators, Fast Fourier Transform, Burg autoregressive method, and minimum variance method, were slightly more accurate than the zero crossing detector (0.984 less than or equal to r less than or equal to 0.994), especially at points close to the walls and with higher levels of turbulence. Steep velocity gradients and transit-time-effects from high velocities produced significantly larger errors in velocity measurement. Wall shear rate estimates were most precise when calculated using the position of the wall and two velocity points. The calculated wall shears were within 20%-30% of theoretically predicted values.

  16. Optimization of Contrast-to-Tissue Ratio by Adaptation of Transmitted Ternary Signal in Ultrasound Pulse Inversion Imaging

    PubMed Central

    Girault, Jean-Marc

    2013-01-01

    Ultrasound contrast imaging has provided more accurate medical diagnoses thanks to the development of innovating modalities like the pulse inversion imaging. However, this latter modality that improves the contrast-to-tissue ratio (CTR) is not optimal, since the frequency is manually chosen jointly with the probe. However, an optimal choice of this command is possible, but it requires precise information about the transducer and the medium which can be experimentally difficult to obtain, even inaccessible. It turns out that the optimization can become more complex by taking into account the kind of generators, since the generators of electrical signals in a conventional ultrasound scanner can be unipolar, bipolar, or tripolar. Our aim was to seek the ternary command which maximized the CTR. By combining a genetic algorithm and a closed loop, the system automatically proposed the optimal ternary command. In simulation, the gain compared with the usual ternary signal could reach about 3.9 dB. Another interesting finding was that, in contrast to what is generally accepted, the optimal command was not a fixed-frequency signal but had harmonic components. PMID:23573167

  17. Flow patterns in carotid bifurcation models using pulsed Doppler ultrasound: effect of concentric vs. eccentric stenosis on turbulence and recirculation.

    PubMed

    Poepping, Tamie L; Rankin, Richard N; Holdsworth, David W

    2010-07-01

    Hemodynamics play a significant role in stroke risk, where thrombus formation may be accelerated in regions of slow or recirculating flow, high shear and increased turbulence. An in vitro investigation was performed with pulsed Doppler ultrasound (DUS) using the complete spectral data to investigate the three-dimensional (3-D) distribution of advanced parameters that may have potential for making a more specific in vivo diagnosis of carotid disease and stroke risk. The effect of stenosis symmetry and the potential of DUS spectral parameters for visualizing regions of recirculation or turbulence were explored. DUS was used to map pulsatile flow in four model geometries representing two different plaque symmetries (eccentricity) and two stenosis severities (mild, severe). Qualitative comparisons were made with flow patterns visualized using digital particle imaging. Color-encoded maps of DUS spectral parameters (mean velocity, spectral-broadening index and turbulence intensity) clearly distinguished regions of slow or recirculating flow and disturbed or turbulent flow. Distinctly different flow patterns resulted from stenoses of equal severity but different eccentricity. Noticeable differences were seen in both the size and location of recirculation zones and in the paths of high-velocity jets. Highly elevated levels of turbulence intensity were seen distal to severe stenosis. Results demonstrated the importance of plaque shape, which is typically not considered in standard diagnosis, in addition to stenosis severity. Copyright 2010 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  18. The leicester Doppler phantom--a digital electronic phantom for ultrasound pulsed Doppler system testing.

    PubMed

    Gittins, John; Martin, Kevin

    2010-04-01

    Doppler flow and string phantoms have been used to assess the performance of ultrasound Doppler systems in terms of parameters such as sensitivity, velocity accuracy and sample volume registration. However, because of the nature of their construction, they cannot challenge the accuracy and repeatability of modern digital ultrasound systems or give objective measures of system performance. Electronic Doppler phantoms are able to make use of electronically generated test signals, which may be controlled precisely in terms of frequency, amplitude and timing. The Leicester Electronic Doppler Phantom uses modern digital signal processing methods and field programmable gate array technology to overcome some of the limitations of previously described electronic phantoms. In its present form, it is able to give quantitative graphical assessments of frequency response and range gate characteristics, as well as measures of dynamic range and velocity measurement accuracy. The use of direct acoustic coupling eliminates uncertainties caused by Doppler beam effects, such as intrinsic spectral broadening, but prevents their evaluation.

  19. Heating simulations of pulsed high-intensity focused ultrasound in the presence of heterogeneous tissue

    NASA Astrophysics Data System (ADS)

    Zhou, Hao; Zheng, Yinfei; Duan, Huilong

    2017-03-01

    A numerical model for evaluating the distribution of the acoustic pressure and temperature beneath the abdominal wall or the chest wall under nonablative high-intensity ultrasound treatments is proposed. The nonlinear propagation of the ultrasound wave was simulated using a k-space pseudo-spectral method. The abdominal wall (heterogeneous medium) was presented by the digital tissue cross sections. The heating process was modeled by solving the bioheat equation using a finite difference time domain (FDTD) method. As indicated in the simulation, the presents of the heterogeneous tissue can influence the distribution of the acoustic intensity. The intensity beneath the abdominal wall was decreased by 2.2 dB on the focal point compared with homogeneous tissue and the temperature of the focused region in the tissue is reduced as a result. Furthermore, compared with conventional 2-order FDTD methods, the proposed model is still stable when the high dissipative tissue (e.g., bone) presents.

  20. CONTRAST-ENHANCED INTRAVASCULAR ULTRASOUND PULSE SEQUENCES FOR BANDWIDTH-LIMITED TRANSDUCERS

    PubMed Central

    Maresca, David; Renaud, Guillaume; van Soest, Gijs; Li, Xiang; Zhou, Qifa; Shung, K. Kirk; de Jong, Nico; van der Steen, Antonius F. W.

    2013-01-01

    We demonstrate two methods for vasa vasorum imaging using contrast-enhanced intravascular ultrasound, which can be performed using commercial catheters. Plaque neovascularization was recognized as an independent marker of coronary artery plaque vulnerability. IVUS-based methods to image the microvessels available to date require high bandwidth (−6 dB relative frequency bandwidth >70%), which are not routinely available commercially. We explored the potential of ultraharmonic imaging and chirp reversal imaging for vasa vasorum imaging. In vitro recordings were performed on a tissue-mimicking phantom using a commercial ultrasound contrast agent and a transducer with a center frequency of 34 MHz and a −6 dB relative bandwidth of 56%. Acoustic peak pressures <500 kPa were used. A tissue-mimicking phantom with channels down to 200 μm in diameter was successfully imaged by the two contrast detection sequences while the smallest channel stayed invisible in conventional intravascular ultrasound images. Ultraharmonic imaging provided the best contrast agent detection. PMID:23384459

  1. Analysis of ultrasound pulse-echo images for characterization of muscle disease

    NASA Astrophysics Data System (ADS)

    Leeman, Sidney; Heckmatt, John Z.

    1996-04-01

    This study aims to extract quantifiable indices characterizing ultrasound propagation and scattering in skeletal muscle, from data acquired using a real-time linear array scanner in a paediatric muscle clinic, in order to establish early diagnosis of Duchenne muscular dystrophy in young children, as well as to chart the progressive severity of the disease. Approximately 40 patients with gait disorders, aged between 1 and 11 years, were scanned with a real-time linear array ultrasound scanner, at 5 MHz. A control group consisted of approximately 50 boys, in the same age range, with no evidence or history of muscle disease. Results show that ultrasound quantitative methods can provide a tight clustering of normal data, and also provide a basis for charting the degree of change in diseased muscle. The most significant (quantitative) parameters derive from the frequency of the attenuation and the muscle echogenicity. The approach provides a discrimination method that is more sensitive than visual assessment of the corresponding image by even an experienced observer. There are also indications that the need for traumatic muscle biopsy may be obviated in some cases.

  2. Effects of pulsed therapeutic ultrasound on the treatment of people with knee osteoarthritis

    PubMed Central

    Rodríguez-Grande, Eliana-Isabel; Osma-Rueda, Jose-Luis; Serrano-Villar, Yannely; Ramírez, Carolina

    2017-01-01

    [Purpose] The aim was to evaluate the effect of therapeutic ultrasound on the pain, joint mobility, muscle strength, physical function, and quality of life of people with knee OA. [Subjects and Methods] One-site, one-arm, before-after study that included people with Grade II or III tibiofemoral osteoarthritis. Ten therapeutic ultrasound sessions (duty cycle=20%, ERA=10 cm2, BNR=6:1, SATP=2.2 W/cm2, SATA=0.44 W/cm2, frequency=1 MHz, time=4 minutes) were applied. Assessments of primary outcome variables: pain intensity and function, and secondary variables: joint mobility, muscle strength and quality of life, were performed at onset and end of therapy; an additional intermediate evaluation was included for the primary variables. [Results] Means of repeated measurements of pain intensity (pain at rest, pain on palpation and pain after functional activities) and function showed significant differences. There was a significant reduction in pain intensity at the end of functional activities as well as a significant increase in function and in quadriceps muscle strength. [Conclusion] Therapeutic ultrasound applied in accordance with the parameters used, could be recommended during the treatment of individuals with knee osteoarthritis, because it significantly decreased the intensity of pain after the 5th session, and this reduction was maintained until the end of the intervention. PMID:28932004

  3. [Low-intensity laser radiation in preventive measures].

    PubMed

    Ushkova, I N; Nal'kova, N Yu; Chernushevich, N I; Popov, A V; Kochetova, O A

    2013-01-01

    Results of preventive measures introduction in 524 PC users, 98 jewelry polishers and 64 metallic ship hull assemblers are given. The use of preventive measures, based on low-intensity laser radiation, was shown to prevent development of visual overfatigue and occupational musculoskeletal system diseases.

  4. Low-Intensity channel catfish culture re-visited

    USDA-ARS?s Scientific Manuscript database

    Channel catfish (Ictalurus punctatus) farmers can use a variety of management strategies to produce the larger-sized fish that processing plants increasingly seek. A low-intensity production strategy based on low stocking and aeration rates can be used to produce larger channel catfish. Stocker catf...

  5. [Mechanism of radiobiological effects of low intensity nonionizing electromagnetic radiation].

    PubMed

    Kudriashov, Iu B; Perov, Iu F; Golenitskaia, I A

    1999-01-01

    The results of the research of the biological effects of the non-ionizing electromagnetic radiation were studied from the position of "thermal" and "unthermal" mechanisms. The special attention was spared to analysing the information characterising the high sensitiveness of the human and animals organism to the very-low intensity electromagnetic fields.

  6. Control of broadband optically generated ultrasound pulses using binary amplitude holograms.

    PubMed

    Brown, Michael D; Jaros, Jiri; Cox, Ben T; Treeby, Bradley E

    2016-04-01

    In this work, the use of binary amplitude holography is investigated as a mechanism to focus broadband acoustic pulses generated by high peak-power pulsed lasers. Two algorithms are described for the calculation of the binary holograms; one using ray-tracing, and one using an optimization based on direct binary search. It is shown using numerical simulations that when a binary amplitude hologram is excited by a train of laser pulses at its design frequency, the acoustic field can be focused at a pre-determined distribution of points, including single and multiple focal points, and line and square foci. The numerical results are validated by acoustic field measurements from binary amplitude holograms, excited by a high peak-power laser.

  7. Inertial cavitation in theranostic nanoemulsions with simultaneous pulsed laser and low frequency ultrasound excitation

    NASA Astrophysics Data System (ADS)

    Arnal, Bastien; Wei, Chen-Wei; Xia, Jinjun; Pelivanov, Ivan M.; Lombardo, Michael; Perez, Camilo; Matula, Thomas J.; Pozzo, Danilo; O'Donnell, Matthew

    2014-03-01

    Ultrasound-induced inertial cavitation is a mechanical process used for site-localized therapies such as non-invasive surgery. Initiating cavitation in tissue requires very high intensity focused ultrasound (HIFU) and low-frequencies. Hence, some applications like thrombolysis require targeted contrast agents to reduce peak intensities and the potential for secondary effects. A new type of theranostic nanoemulsion has been developed as a combined ultrasound (US)/photoacoustic(PA) agent for molecular imaging and therapy. It includes a nanoscale emulsion core encapsulated with a layer of gold nanospheres at the water/ oil interface. Its optical absorption exhibits a spectrum broadened up to 1100 nm, opening the possibility that 1064 nm light can excite cavitation nuclei. If optically-excited nuclei are produced at the same time that a low-frequency US wave is at peak negative pressure, then highly localized therapies based on acoustic cavitation may be enabled at very low US pressures. We have demonstrated this concept using a low-cost, low energy, portable 1064 nm fiber laser in conjunction with a 1.24 MHz US transducer for simultaneous laser/US excitation of nanoemulsions. Active cavitation detection from backscattered signals indicated that cavitation can be initiated at very low acoustic pressures (less than 1 MPa) when laser excitation coincides with the rarefaction phase of the acoustic wave, and that no cavitation is produced when light is delivered during the compressive phase. US can sustain cavitation activity during long acoustic bursts and stimulate diffusion of the emulsion, thus increasing treatment speed. An in vitro clot model has been used to demonstrate combined US and laser excitation of the nanoemulsion for efficient thrombolysis.

  8. Ultrasound spectroscopy

    NASA Astrophysics Data System (ADS)

    Giles, C. L.

    An ultrasound spectrometer was designed, constructed and used to measure the frequency dependence of forward scattered ultrasound from biological specimens. A piezoelectric transducer was continuously tuned through the frequency range of 150 to 400 MHz, producing ultrasound of the same frequency. Pulse modulation of the input signal permitted a frequency resolution of 2 MHz. The received pulse was detected at various temporal positions of its amplitude, thereby allowing measurement of the interference of the scattered and unscattered ultrasound radiation. Because of system nonlinearities all received signals were calibrated with respect to the attenuation of ultrasound in water over the system frequency range. The attenuation of water over the frequency range of 150 to 400 MHz was measured. Forward scattering experiments were performed with both physical objects and biological specimens. Sapphire spheres and plastic cylinders exhibited the expected Mie scattering resonant structure.

  9. DNA fragmentation and nuclear phenotype in tendons exposed to low-intensity infrared laser

    NASA Astrophysics Data System (ADS)

    de Paoli, Flavia; Ramos Cerqueira, Larissa; Martins Ramos, Mayara; Campos, Vera M.; Ferreira-Machado, Samara C.; Geller, Mauro; de Souza da Fonseca, Adenilson

    2015-03-01

    Clinical protocols are recommended in device guidelines outlined for treating many diseases on empirical basis. However, effects of low-intensity infrared lasers at fluences used in clinical protocols on DNA are controversial. Excitation of endogenous chromophores in tissues and free radicals generation could be described as a consequence of laser used. DNA lesions induced by free radicals cause changes in DNA structure, chromatin organization, ploidy degrees and cell death. In this work, we investigated whether low-intensity infrared laser therapy could alter the fibroblasts nuclei characteristics and induce DNA fragmentation. Tendons of Wistar rats were exposed to low-intensity infrared laser (830 nm), at different fluences (1, 5 and 10 J/cm2), in continuous wave (power output of 10mW, power density of 79.6 mW/cm2). Different frequencies were analyzed for the higher fluence (10 J/cm2), at pulsed emission mode (2.5, 250 and 2500 Hz), with the laser source at surface of skin. Geometric, densitometric and textural parameters obtained for Feulgen-stained nuclei by image analysis were used to define nuclear phenotypes. Significant differences were observed on the nuclear phenotype of tendons after exposure to laser, as well as, high cell death percentages was observed for all fluences and frequencies analyzed here, exception 1 J/cm2 fluence. Our results indicate that low-intensity infrared laser can alter geometric, densitometric and textural parameters in tendon fibroblasts nuclei. Laser can also induce DNA fragmentation, chromatin lost and consequently cell death, using fluences, frequencies and emission modes took out from clinical protocols.

  10. Effect of hydrodynamic cavitation in the tissue erosion by pulsed high-intensity focused ultrasound (pHIFU).

    PubMed

    Zhou, Yufeng; Gao, Xiaobin Wilson

    2016-09-21

    High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in clinics. Besides the thermal ablation, tissue disintegration is also possible because of the interaction between the distorted HIFU bursts and either bubble cloud or boiling bubble. Hydrodynamic cavitation is another type of cavitation and has been employed widely in industry, but its role in mechanical erosion to tissue is not clearly known. In this study, the bubble dynamics immediately after the termination of HIFU exposure in the transparent gel phantom was captured by high-speed photography, from which the bubble displacement towards the transducer and the changes of bubble size was quantitatively determined. The characteristics of hydrodynamic cavitation due to the release of the acoustic radiation force and relaxation of compressed surrounding medium were found to associate with the number of pulses delivered and HIFU parameters (i.e. pulse duration and pulse repetition frequency). Because of the initial big bubble (~1 mm), large bubble expansion (up to 1.76 folds), and quick bubble motion (up to ~1 m s(-1)) hydrodynamic cavitation is significant after HIFU exposure and may lead to mechanical erosion. The shielding effect of residual tiny bubbles would reduce the acoustic energy delivered to the pre-existing bubble at the focus and, subsequently, the hydrodynamic cavitation effect. Tadpole shape of mechanical erosion in ex vivo porcine kidney samples was similar to the contour of bubble dynamics in the gel. Liquefied tissue was observed to emit towards the transducer through the punctured tissue after HIFU exposure in the sonography. In summary, the release of HIFU exposure-induced hydrodynamic cavitation produces significant bubble expansion and motion, which may be another important mechanism of tissue erosion. Understanding its mechanism and optimizing the outcome would broaden and enhance HIFU applications.

  11. Multi-frequency accelerating strategy for the contrast source inversion method of ultrasound waveform tomography using pulse data

    NASA Astrophysics Data System (ADS)

    Lin, Hongxiang; Azuma, Takashi; Qu, Xiaolei; Takagi, Shu

    2017-03-01

    In this work, we construct a multi-frequency accelerating strategy for the contrast source inversion (CSI) method using pulse data in the time domain. CSI is a frequency-domain inversion method for ultrasound waveform tomography that does not require the forward solver through the process of reconstruction. Several prior researches show that the CSI method has a good performance of convergence and accuracy in the low-center-frequency situation. In contrast, utilizing the high-center-frequency data leads to a high-resolution reconstruction but slow convergence on large numbers of grid. Our objective is to take full advantage of all low frequency components from pulse data with the high-center-frequency data measured by the diagnostic device. First we process the raw data in the frequency domain. Then multi-frequency accelerating strategy helps restart CSI in the current frequency using the last iteration result obtained from the lower frequency component. The merit of multi- frequency accelerating strategy is that computational burden decreases at the first few iterations. Because the low frequency component of dataset computes on the coarse grid with assuming a fixed number of points per wavelength. In the numerical test, the pulse data were generated by the K-wave simulator and have been processed to meet the computation of the CSI method. We investigate the performance of the multi-frequency and single-frequency reconstructions and conclude that the multi-frequency accelerating strategy significantly enhances the quality of the reconstructed image and simultaneously reduces the average computational time for any iteration step.

  12. Effect of hydrodynamic cavitation in the tissue erosion by pulsed high-intensity focused ultrasound (pHIFU)

    NASA Astrophysics Data System (ADS)

    Zhou, Yufeng; Gao, Xiaobin Wilson

    2016-09-01

    High-intensity focused ultrasound (HIFU) is emerging as an effective therapeutic modality in clinics. Besides the thermal ablation, tissue disintegration is also possible because of the interaction between the distorted HIFU bursts and either bubble cloud or boiling bubble. Hydrodynamic cavitation is another type of cavitation and has been employed widely in industry, but its role in mechanical erosion to tissue is not clearly known. In this study, the bubble dynamics immediately after the termination of HIFU exposure in the transparent gel phantom was captured by high-speed photography, from which the bubble displacement towards the transducer and the changes of bubble size was quantitatively determined. The characteristics of hydrodynamic cavitation due to the release of the acoustic radiation force and relaxation of compressed surrounding medium were found to associate with the number of pulses delivered and HIFU parameters (i.e. pulse duration and pulse repetition frequency). Because of the initial big bubble (~1 mm), large bubble expansion (up to 1.76 folds), and quick bubble motion (up to ~1 m s-1) hydrodynamic cavitation is significant after HIFU exposure and may lead to mechanical erosion. The shielding effect of residual tiny bubbles would reduce the acoustic energy delivered to the pre-existing bubble at the focus and, subsequently, the hydrodynamic cavitation effect. Tadpole shape of mechanical erosion in ex vivo porcine kidney samples was similar to the contour of bubble dynamics in the gel. Liquefied tissue was observed to emit towards the transducer through the punctured tissue after HIFU exposure in the sonography. In summary, the release of HIFU exposure-induced hydrodynamic cavitation produces significant bubble expansion and motion, which may be another important mechanism of tissue erosion. Understanding its mechanism and optimizing the outcome would broaden and enhance HIFU applications.

  13. Visualization of Electrical Trees by 80 MHz-band Pulsed Ultrasound

    NASA Astrophysics Data System (ADS)

    Kida, Satoshi; Murakami, Yoshinobu; Nagao, Masayuki; Hozumi, Naohiro

    Power modules are often molded with a resin, such as epoxy, for their protection and downsizing. The resin, which contains inorganic filler, is usually non-transparent. As optical inspection is not realistic, non-destructive inspections using X-ray or ultrasound is being performed. As for cracks and so-called “electrical tree” in the insulation, ultrasound may bring a good contrast, because there is a big difference in acoustic impedance between resin and air. There are some reports on ultrasonic observation for electrical trees, however, as thick specimens were employed, the spatial resolution was very poor due to the limitation of available frequency range. However, the diameter of electrical tree path is as thin as 5 μm. Enough resolution can't be obtained by the measurement with a low frequency range. Based on the above background, we tried to observe a “close but small” tree by ultrasonic imaging. Using the wide-band ultrasonic microscope, it was examined if a tree with 0.5 mm in scale could be observed with its fine structure. An ultrasonic image, in which branching in the tree can be discriminated. The spatial resolution was determined as 40∼50 μm. An image processing was carried out in order to acquire a clearer image. Assuming the Gaussian as a blur function, the original image was deconvolved.

  14. [Effects of low-frequency pulsed wave ultrasound on the shear properties of the interface of vancomycin-loaded acrylic bone cement-stem].

    PubMed

    Zhao, Q H; Zhu, F B; Cai, X Z; Yan, S G; He, R X

    2017-02-21

    Objective: To investigate the effects of low-frequency pulsed wave ultrasound on the shear properties of interface of the vancomycin -loaded acrylic bone cement-stem. Methods: The interfaces of 1% vancomycin-loaded acrylic bone cement-stem specimences were successfully manufactured and randomly divided into three groups: the control group, 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) ultrasound group, each group consisted of eight samples.Two ultrasound groups were exposed to a local ultrasonic field for 7 d, then immersed in PBS for 23 d, and the control groups were immersed in PBS for 30 d. After curing in air for 24 h, the shear strength of the stem-cement interface was determined by push-out test.The specimens were then photographed using SEM and analysed using Image-Pro Plus 6.0 to determine the porosity at the stem-cement interface. Results: The mean shear strength of stem-cement interface additionally decreased by 9% (P>0.05) and 17% (P<0.05) in 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) group respectively comparing with the control group, but no significant difference was found between the two ultrasound groups.The porosity at the stem-cement interface additionally increased by 44% (P>0.05) and 110% (P<0.05) in 450 mW/cm(2) ultrasound group and 1 200 mW/cm(2) group respectively comparing with the control group, furthermore.The porosity in 1 200 mW/cm(2) ultrasound group increased by 46% (P<0.05) comparing with the 450 mW/cm(2) group. There are much more fluid penetration along the stem-cement interface in ultrasound group . Conclusion: Low-frequency pulsed wave ultrasound signifiantly enhanced porosity and fluid penetration interface, and reduced the interface shear strength and initial stability.

  15. Evolving Medical Strategies for Low Intensity Conflicts - A Necessity.

    PubMed

    Dheer, Ajay; Jaiprakash; Sharma, H K; Singh, Jasdeep

    2003-04-01

    Military medicine is the development within the art and science which is designed to carry out a specialized, essential and a highly significant mission under the adverse conditions of war. Low Intensity Conflict (LIC) is a mode of warfare which has come to stay and the Indian Military has to confront it as such. It is a campaign of nerves, less military and more psychological, with soldiers inevitably fighting with hands behind their back. The dichotomy the soldier faces, results in high levels of frustration leading to various stress disorders. The key in casualty survival lies in correct and timely psychological first-aid for which every section and platoon commander should be trained. Post Trauma Stress Disorder caused as a result of traumatic experience can deplete unit's efficiency and therefore needs monitoring for early detection and treatment. Evolving medical strategies for Low Intensity Conflict Operations (LICO), therefore assumes significance.

  16. Modelling the propagation of ultrasound in the joint space of a human knee.

    PubMed

    White, Derrick; Evans, Joseph A; Truscott, John G; Chivers, Robin A

    2010-10-01

    There is strong evidence to support the clinical use of low-intensity pulsed ultrasound (LIPUS) to augment fracture healing. A previous experimental study showed that ultrasound can propagate in the joint space of a single human cadaveric knee. A full experimental investigation of this propagation is not possible due to poor reproducibility, the scarcity of human cadaveric tissues and the practical difficulties in making ultrasound measurements in the knee. The aim of the present work is to investigate whether a computer simulation (Wave2000 Pro®; Cyberlogic Inc., New York, NY, USA) can give a good representation of the experimental model. The simulations provided a good agreement with the experimental data, giving some confidence in the application of this computer simulation method as a means of determining whether ultrasound can propagate through different anatomical regions where bone is present.

  17. The low intensity X-ray imaging scope /Lixiscope/

    NASA Technical Reports Server (NTRS)

    Yin, L. I.; Trombka, J. I.; Seltzer, S. M.; Webber, R. L.; Farr, M. R.; Rennie, J.

    1978-01-01

    A fully portable, small-format X-ray imaging system, Lixiscope (low intensity X-ray imaging scope) is described. In the prototype, which has been built to demonstrate the feasibility of the Lixiscope concept, only well-developed and available components have been used. Consideration is given to the principles of operation of the device, some of its performance characteristics as well as possible dental, medical and industrial applications.

  18. Low-Intensity Conflicts and the United States Marine Corps

    DTIC Science & Technology

    1991-04-05

    POLI CY Back in 1i;:-:7 the United States Congress saw the immediate need for. policy and guidance i-, low-intensity conflicts. They directed the...s: RolIEs in Low’- Intersi ty ConiflIicts. " ilI itai-y F-.eview, Vaol - 2, 1 J anVi’.Aa -y 1990 , p.~-. Armstrong, Charles L . "The Decl1inie of Lovi

  19. Lessons Learned by Venezuela Fighting in Low Intensity Conflict

    DTIC Science & Technology

    1993-03-05

    BUILDING 122 CARLISLE, PA 17013-5050 ga. NAME OF FUNDING/SPONSORING I 8b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION I...Congress, 29 April 1960. 1 7Colonel Juan Biaggini Gutierrez et al., Los Cinco de Linea (Caracas: Direccion de Educaion del Ejercito, 4 August 1980), 102...Barracks, PA : U.S. Army War College, 3 August 1992. Low Intensity Conflict. Venezuela Case Study. Fort Leavenworth, KS: U.S. Army Command and General Staff

  20. The low intensity X-ray imaging scope /Lixiscope/

    NASA Technical Reports Server (NTRS)

    Yin, L. I.; Trombka, J. I.; Seltzer, S. M.; Webber, R. L.; Farr, M. R.; Rennie, J.

    1978-01-01

    A fully portable, small-format X-ray imaging system, Lixiscope (low intensity X-ray imaging scope) is described. In the prototype, which has been built to demonstrate the feasibility of the Lixiscope concept, only well-developed and available components have been used. Consideration is given to the principles of operation of the device, some of its performance characteristics as well as possible dental, medical and industrial applications.

  1. The Air Force Role in Low-Intensity Conflict

    DTIC Science & Technology

    1986-10-01

    Staff. A graduate of the Georgetown University School of Foreign Service (BSFS) and Florida State University (MA), Lieutenant Colonel Dean has served in...beyond. The volatility of the newly developing countries will be such that disruptions to lines of supply coupled with the vulnerability of key areas...counterinsurgency . A case study of modern low-intensity conflict, one in which air power has been playing a key role, will point out in real world

  2. Enhanced homing permeability and retention of bone marrow stromal cells (BMSC) by non-invasive pulsed focused ultrasound

    PubMed Central

    Ziadloo, Ali; Burks, Scott R.; Gold, Eric M.; Lewis, Bobbi K.; Chaudhry, Aneeka; Merino, Maria J.; Frenkel, Victor; Frank, Joseph A.

    2012-01-01

    Bone marrow stromal cells (BMSC) have shown significant promise in the treatment of disease, but their therapeutic efficacy is often limited by inefficient homing of systemically-administered cells, which results in low numbers of cells accumulating at sites of pathology. BMSC home to areas of inflammation where local expression of integrins and chemokine gradients are present. We demonstrated that non-destructive pulsed focused ultrasound (pFUS) exposures that emphasize the mechanical effects of ultrasound-tissue interactions induced local and transient elevations of chemoattractants (i.e., cytokines, integrins, and growth factors) in the murine kidney. pFUS-induced upregulation of cytokines occurred through approximately 1 day post-treatment and returned to contralateral kidney levels by day 3. This window of significant increases in cytokine expression was accompanied by local increases of other trophic factors and integrins that have been shown to promote BMSC homing. When BMSC were administered intravenously following pFUS treatment to a single kidney, enhanced homing, permeability, and retention of BMSC was observed in the treated kidney versus the contralateral kidney. Histological analysis revealed up to 8 times more BMSC in the peritubular regions of the treated kidneys on days 1 and 3 post-treatment. Furthermore, cytokine levels in pFUS-treated kidneys following BMSC administration were found to be similar to controls, suggesting modulation of cytokine levels by BMSC. pFUS could potentially improve cell-based therapies as a noninvasive modality to target BMSC homing by establishing local chemoattractant gradients and increasing expression of integrins to enhance tropism of BMSC toward treated tissues. PMID:22593018

  3. Advances in endonasal low intensity laser irradiation therapy

    NASA Astrophysics Data System (ADS)

    Jiao, Jian-Ling; Liu, Timon C.; Liu, Jiang; Cui, Li-Ping; Liu, Song-hao

    2005-07-01

    Endonasal low intensity laser therapy (ELILT) began in China in 1998. Now in China it is widely applied to treat hyperlipidemia and brain diseases such as Alzheimer's disease, Parkinson's disease, insomnia, poststroke depression, intractable headache, ache in head or face, cerebral thrombosis, acute ischemic cerebrovascular disease, migraine, brain lesion and mild cognitive impairment. There are four pathways mediating EILILT, Yangming channel, autonomic nervous systems and blood cells. Two unhealth acupoints of Yangming channal inside nose might mediate the one as is low intensity laser acupuncture. Unbalance autonomic nervous systems might be modulated. Blood cells might mediate the one as is intravascular low intensity laser therapy. These three pathways are integrated in ELILT so that serum amyloid β protein, malformation rate of erythrocyte, CCK-8, the level of viscosity at lower shear rates and hematocrit, or serum lipid might decrease, and melanin production/SOD activity or β endorphin might increase after ELILT treatment. These results indicate ELILT might work, but it need to be verified by randomized placebo-controlled trial.

  4. Transvaginal ultrasound

    MedlinePlus

    ... Uterine bleeding - transvaginal ultrasound; Menstrual bleeding - transvaginal ultrasound; Infertility - transvaginal ultrasound; Ovarian - transvaginal ultrasound; Abscess - transvaginal ultrasound

  5. Ultrasound pregnancy

    MedlinePlus

    Pregnancy sonogram; Obstetric ultrasonography; Obstetric sonogram; Ultrasound - pregnancy; IUGR - ultrasound; Intrauterine growth - ultrasound; Polyhydramnios - ultrasound; Oligohydramnios - ultrasound; ...

  6. Joint Low-Intensity Conflict Project Final Report. Volume 1. Analytical Review of Low-Intensity Conflict

    DTIC Science & Technology

    1986-08-01

    findings. Whenever the masculine gender is used, both genders , where appropriate, are intended. ii JOINT LOW-INTENSITY CONFLICT PROJECT FINAL REPORT...conflicts. 2 Osgood felt this opposition resulted from a number of popular perceptions: o Such involvements are messy and tend to spill over borders...half of which included the use of combat forces, the American public refused to continue to wage a large and messy war. Ultimately, the government

  7. Temporally-Specific Modification of Myelinated Axon Excitability In Vitro Following a Single Ultrasound Pulse

    DTIC Science & Technology

    1990-01-01

    corresponding to local temperature rises of the nerve trunk of no more than 0.25* C per pulse, thereby precluding bulk heating as a basis of this effect... Henneman 19Ua.. 1961b: Fry et al. 1958). and direct modification of A great deal of investigation concerning the effects of receptor potentials in...in vitro R. T. MlHRAf4 et aL V Z a S C 0. 0 20 40 s0 so 100 (a) Paet-Pulee Stliaton Delay (mus) 10 . c 1.6 c 4 at 0. 0 20 40 60 60 100 (b) paut

  8. Reduction in mechanical allodynia in complex regional pain syndrome patients with ultrasound-guided pulsed radiofrequency treatment of the superficial peroneal nerve

    PubMed Central

    Chae, Won Soek; Kim, Sang Hyun; Cho, Sung Hwan; Lee, Mi Sun

    2016-01-01

    The superficial peroneal nerve is vulnerable to damage from ankle sprain injuries and fractures as well as surgery to this region. And it is also one of the most commonly involved nerves in complex regional pain syndrome type II in the foot and ankle region. We report two cases of ultrasound-guided pulsed radiofrequency treatment of superficial peroneal nerve for reduction of allodynia in CRPS patients. PMID:27738506

  9. Effect of acoustic parameters on the cavitation behavior of SonoVue microbubbles induced by pulsed ultrasound.

    PubMed

    Lin, Yutong; Lin, Lizhou; Cheng, Mouwen; Jin, Lifang; Du, Lianfang; Han, Tao; Xu, Lin; Yu, Alfred C H; Qin, Peng

    2017-03-01

    SonoVue microbubbles could serve as artificial nuclei for ultrasound-triggered stable and inertial cavitation, resulting in beneficial biological effects for future therapeutic applications. To optimize and control the use of the cavitation of SonoVue bubbles in therapy while ensuring safety, it is important to comprehensively understand the relationship between the acoustic parameters and the cavitation behavior of the SonoVue bubbles. An agarose-gel tissue phantom was fabricated to hold the SonoVue bubble suspension. 1-MHz transmitting transducer calibrated by a hydrophone was used to trigger the cavitation of SonoVue bubbles under different ultrasonic parameters (i.e., peak rarefactional pressure (PRP), pulse repetition frequency (PRF), and pulse duration (PD)). Another 7.5-MHz focused transducer was employed to passively receive acoustic signals from the exposed bubbles. The ultraharmonics and broadband intensities in the acoustic emission spectra were measured to quantify the extent of stable and inertial cavitation of SonoVue bubbles, respectively. We found that the onset of both stable and inertial cavitation exhibited a strong dependence on the PRP and PD and a relatively weak dependence on the PRF. Approximate 0.25MPa PRP with more than 20μs PD was considered to be necessary for ultraharmonics emission of SonoVue bubbles, and obvious broadband signals started to appear when the PRP exceeded 0.40MPa. Moreover, the doses of stable and inertial cavitation varied with the PRP. The stable cavitation dose initially increased with increasing PRP, and then decreased rapidly after 0.5MPa. By contrast, the inertial cavitation dose continuously increased with increasing PRP. Finally, the doses of both stable and inertial cavitation were positively correlated with PRF and PD. These results could provide instructive information for optimizing future therapeutic applications of SonoVue bubbles.

  10. Photoacoustic measurement for glucose solution concentration based on tunable pulsed laser induced ultrasound

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen; Zhao, Dengji

    2012-12-01

    Noninvasive measurement of blood glucose concentration (BGC) has become a research hotspot. BGC measurement based on photoacoustic spectroscopy (PAS) was employed to detect the photoacoustic (PA) signal of blood glucose due to the advantages of avoiding the disturbance of optical scattering. In this paper, a set of custom-built BGC measurement system based on tunable optical parametric oscillator (OPO) pulsed laser and ultrasonic transducer was established to test the PA response effect of the glucose solution. In the experiments, we successfully acquired the time resolved PA signals of distilled water and glucose aqueous solution, and the PA peak-to-peak values(PPV) were gotten under the condition of excitated pulsed laser with changed wavelength from 1340nm to 2200nm by increasing interval of 10nm, the optimal characteristic wavelengths of distilled water and glucose solution were determined. Finally, to get the concentration prediction error, we used the linear fitting of ordinary least square (OLS) algorithm to fit the PPV of 1510nm, and we got the predicted concentration error was about 0.69mmol/L via the fitted linear equation. So, this system and scheme have some values in the research of noninvasive BGC measurement.

  11. Three-dimensional noninvasive ultrasound Joule heat tomography based on the acousto-electric effect using unipolar pulses: a simulation study.

    PubMed

    Yang, Renhuan; Li, Xu; Song, Aiguo; He, Bin; Yan, Ruqiang

    2012-11-21

    Electrical properties of biological tissues are highly sensitive to their physiological and pathological status. Thus it is of importance to image electrical properties of biological tissues. However, spatial resolution of conventional electrical impedance tomography (EIT) is generally poor. Recently, hybrid imaging modalities combining electric conductivity contrast and ultrasonic resolution based on the acousto-electric effect has attracted considerable attention. In this study, we propose a novel three-dimensional (3D) noninvasive ultrasound Joule heat tomography (UJHT) approach based on the acousto-electric effect using unipolar ultrasound pulses. As the Joule heat density distribution is highly dependent on the conductivity distribution, an accurate and high-resolution mapping of the Joule heat density distribution is expected to give important information that is closely related to the conductivity contrast. The advantages of the proposed ultrasound Joule heat tomography using unipolar pulses include its simple inverse solution, better performance than UJHT using common bipolar pulses and its independence of a priori knowledge of the conductivity distribution of the imaging object. Computer simulation results show that using the proposed method, it is feasible to perform a high spatial resolution Joule heat imaging in an inhomogeneous conductive media. Application of this technique on tumor scanning is also investigated by a series of computer simulations.

  12. Hemodynamic effect of percutaneous transluminal angioplasty for lower limb atherosclerosis. A study based on pulsed Doppler ultrasound flowmetry.

    PubMed

    Jørgensen, J J; Stranden, E; Gjølberg, T

    1987-01-01

    Measurements of ankle pressure index (API) and arterial flow velocity including calculation of pulsatility index (PI) from the common femoral and pedal arteries were performed in 89 limbs of 75 patients before and after percutaneous transluminal angioplasty (PTA) (63 iliac and 26 femoropopliteal). A pulsed wave Doppler ultrasound flowmeter was used. An increase of API at rest of at least 0.15 or the absence of pressure drop after exercise following PTA was used as criteria for a hemodynamically successful angioplasty. In patients with hemodynamically successful PTA of an iliac obstruction PI increased from 4.2 to 8.6 (p less than 0.001); 91 per cent of these patients improved clinically. When iliac angioplasty was hemodynamically unsuccessful, PI remained unchanged; 11 per cent of these patients improved clinically. All limbs with hemodynamically successful PTA of a femoropopliteal obstruction improved clinically and PI increased from 3.1 to 8.7 (p less than 0.001). After hemodynamically unsuccessful femoropopliteal PTA, PI remained unchanged though 25 per cent of these patients improved clinically. These results illustrate that measurement of arterial flow velocity with calculation of PI may be a useful supplement for the functional evaluation of the effect of PTA, since symptomatic response alone may be unreliable.

  13. Comparison between ultrasound-guided interfascial pulsed radiofrequency and ultrasound-guided interfascial block with local anesthetic in myofascial pain syndrome of trapezius muscle.

    PubMed

    Cho, Ik Tae; Cho, Yun Woo; Kwak, Sang Gyu; Chang, Min Cheol

    2017-02-01

    Myofascial pain syndrome (MPS) of the trapezius muscle (TM) is a frequently occurring musculoskeletal disorder. However, the treatment of MPS of the TM remains a challenge. We investigated the effects of ultrasound (US)-guided pulsed radiofrequency (PRF) stimulation on the interfascial area of the TM. In addition, we compared its effect with that of interfascial block (IFB) with 10 mL of 0.6% lidocaine on the interfascial area of the TM. Thirty-six patients with MPS of the TM were included and randomly assigned into 2 groups. Eighteen patients underwent PRF stimulation on the interfascial area of the TM (PRF group) and 18 patients underwent IFB with lidocaine on the same area (IFB group). Pain intensity was evaluated using a numerical rating scale (NRS) at pretreatment, 2, 4, and 8 weeks after treatment. At pretreatment and 8 weeks after treatment, quality of life was assessed using the Short Form-36 Health Survey (SF-36), which includes the physical component score (PCS) and the mental component score (MCS). One patient in the PRF group was lost to follow-up. Patients in both groups showed a significant decrease in NRS scores at 2, 4, and 8 weeks after treatments and a significant increase in PCS and MCS of the SF-36 at 8 weeks after treatments. Two weeks after each treatment, the decrements of NRS scores were not significantly different between the 2 groups. However, 4 and 8 weeks after the procedures, we found that the NRS score was significantly lower in the PRF group than in the IFB group. At 8 weeks after the treatments, PCS and MCS of the SF-36 in the PRF group were significantly higher than those in the IFB group. For the management of MPS of the TM, US-guided interfascial PRF had a better long-term effect on reducing the pain and the quality of life compared to US-guided IFB. Therefore, we think US-guided PRF stimulation on the interfascial area of the TM can be a beneficial alternative to manage the pain following MPS of the TM.

  14. Comparison between ultrasound-guided interfascial pulsed radiofrequency and ultrasound-guided interfascial block with local anesthetic in myofascial pain syndrome of trapezius muscle

    PubMed Central

    Cho, Ik Tae; Cho, Yun Woo; Kwak, Sang Gyu; Chang, Min Cheol

    2017-01-01

    Abstract Myofascial pain syndrome (MPS) of the trapezius muscle (TM) is a frequently occurring musculoskeletal disorder. However, the treatment of MPS of the TM remains a challenge. We investigated the effects of ultrasound (US)-guided pulsed radiofrequency (PRF) stimulation on the interfascial area of the TM. In addition, we compared its effect with that of interfascial block (IFB) with 10 mL of 0.6% lidocaine on the interfascial area of the TM. Thirty-six patients with MPS of the TM were included and randomly assigned into 2 groups. Eighteen patients underwent PRF stimulation on the interfascial area of the TM (PRF group) and 18 patients underwent IFB with lidocaine on the same area (IFB group). Pain intensity was evaluated using a numerical rating scale (NRS) at pretreatment, 2, 4, and 8 weeks after treatment. At pretreatment and 8 weeks after treatment, quality of life was assessed using the Short Form-36 Health Survey (SF-36), which includes the physical component score (PCS) and the mental component score (MCS). One patient in the PRF group was lost to follow-up. Patients in both groups showed a significant decrease in NRS scores at 2, 4, and 8 weeks after treatments and a significant increase in PCS and MCS of the SF-36 at 8 weeks after treatments. Two weeks after each treatment, the decrements of NRS scores were not significantly different between the 2 groups. However, 4 and 8 weeks after the procedures, we found that the NRS score was significantly lower in the PRF group than in the IFB group. At 8 weeks after the treatments, PCS and MCS of the SF-36 in the PRF group were significantly higher than those in the IFB group. For the management of MPS of the TM, US-guided interfascial PRF had a better long-term effect on reducing the pain and the quality of life compared to US-guided IFB. Therefore, we think US-guided PRF stimulation on the interfascial area of the TM can be a beneficial alternative to manage the pain following MPS of the TM. PMID:28151904

  15. Diagnostic Tools For Low Intensity Ion Micro-Beams

    SciTech Connect

    Finocchiaro, P.; Cosentino, L.; Pappalardo, A.; Vervaeke, M.; Volckaerts, B.; Vynck, P.; Hermanne, A.; Thienpont, H.

    2003-08-26

    We have developed two techniques for microscopic ion beam imaging and profiling, both based on scintillators, particularly suitable for applications in Deep Lithography with Protons (DLP) or with heavier ions. The first one employs a scintillating fiberoptic plate and a CCD camera with suitable lenses, the second makes use of a small scintillator optically coupled to a compact photomultiplier. We have proved the possibility of spanning from single beam particles counting up to several nA currents. Both devices are successfully being exploited for on-line control of low and very low intensity proton beams, down to a beam size of less than 50{mu}m.

  16. Fetal Echocardiography and Pulsed-wave Doppler Ultrasound in a Rabbit Model of Intrauterine Growth Restriction

    PubMed Central

    Hodges, Ryan; Endo, Masayuki; La Gerche, Andre; Eixarch, Elisenda; DeKoninck, Philip; Ferferieva, Vessilina; D'hooge, Jan; Wallace, Euan M.; Deprest, Jan

    2013-01-01

    Fetal intrauterine growth restriction (IUGR) results in abnormal cardiac function that is apparent antenatally due to advances in fetoplacental Doppler ultrasound and fetal echocardiography. Increasingly, these imaging modalities are being employed clinically to examine cardiac function and assess wellbeing in utero, thereby guiding timing of birth decisions. Here, we used a rabbit model of IUGR that allows analysis of cardiac function in a clinically relevant way. Using isoflurane induced anesthesia, IUGR is surgically created at gestational age day 25 by performing a laparotomy, exposing the bicornuate uterus and then ligating 40-50% of uteroplacental vessels supplying each gestational sac in a single uterine horn. The other horn in the rabbit bicornuate uterus serves as internal control fetuses. Then, after recovery at gestational age day 30 (full term), the same rabbit undergoes examination of fetal cardiac function. Anesthesia is induced with ketamine and xylazine intramuscularly, then maintained by a continuous intravenous infusion of ketamine and xylazine to minimize iatrogenic effects on fetal cardiac function. A repeat laparotomy is performed to expose each gestational sac and a microultrasound examination (VisualSonics VEVO 2100) of fetal cardiac function is performed. Placental insufficiency is evident by a raised pulsatility index or an absent or reversed end diastolic flow of the umbilical artery Doppler waveform. The ductus venosus and middle cerebral artery Doppler is then examined. Fetal echocardiography is performed by recording B mode, M mode and flow velocity waveforms in lateral and apical views. Offline calculations determine standard M-mode cardiac variables, tricuspid and mitral annular plane systolic excursion, speckle tracking and strain analysis, modified myocardial performance index and vascular flow velocity waveforms of interest. This small animal model of IUGR therefore affords examination of in utero cardiac function that is

  17. Pulmonary ultrasound and pulse oximetry versus chest radiography and arterial blood gas analysis for the diagnosis of acute respiratory distress syndrome: a pilot study.

    PubMed

    Bass, Cameron M; Sajed, Dana R; Adedipe, Adeyinka A; West, T Eoin

    2015-07-21

    In low-resource settings it is not always possible to acquire the information required to diagnose acute respiratory distress syndrome (ARDS). Ultrasound and pulse oximetry, however, may be available in these settings. This study was designed to test whether pulmonary ultrasound and pulse oximetry could be used in place of traditional radiographic and oxygenation evaluation for ARDS. This study was a prospective, single-center study in the ICU of Harborview Medical Center, a referral hospital in Seattle, Washington, USA. Bedside pulmonary ultrasound was performed on ICU patients receiving invasive mechanical ventilation. Pulse oximetric oxygen saturation (SpO2), partial pressure of oxygen (PaO2), fraction of inspired oxygen (FiO2), provider diagnoses, and chest radiograph closest to time of ultrasound were recorded or interpreted. One hundred and twenty three ultrasound assessments were performed on 77 consecutively enrolled patients with respiratory failure. Oxygenation and radiographic criteria for ARDS were met in 35 assessments. Where SpO2 ≤ 97%, the Spearman rank correlation coefficient between SpO2/FiO2 and PaO2/FiO2 was 0.83, p < 0.0001. The sensitivity and specificity of the previously reported threshold of SpO2/FiO2 ≤ 315 for PaO2/FiO2 ≤ 300 was 83% (95% confidence interval (CI) 68-93), and 50% (95% CI 1-99), respectively. Sensitivity and specificity of SpO2/FiO2 ≤ 235 for PaO2/FiO2 ≤ 200 was 70% (95% CI 47-87), and 90% (95% CI 68-99), respectively. For pulmonary ultrasound assessments interpreted by the study physician, the sensitivity and specificity of ultrasound interstitial syndrome bilaterally and involving at least three lung fields were 80% (95% CI 63-92) and 62% (95% CI 49-74) for radiographic criteria for ARDS. Combining SpO2/FiO2 with ultrasound to determine oxygenation and radiographic criteria for ARDS, the sensitivity was 83% (95% CI 52-98) and specificity was 62% (95% CI 38-82). For moderate-severe ARDS criteria (PaO2/FiO2

  18. Applications of ultrasound to enhance mycophenolic acid production.

    PubMed

    Zhao, Yupeng; Ang, Woon T; Xing, James; Zhang, Jian; Chen, Jie

    2012-09-01

    Reducing production costs for fermentation-based drugs (e.g., antibiotics) is crucial for the long-term sustainability of healthcare. In this study, we propose a novel low-intensity pulsed ultrasound (LIPUS) stimulation scheme using a nominal frequency of 1.5 MHz with a 20% duty cycle (200 μs ultrasound on and 800 μs ultrasound off) to increase production of fermentation-based drugs. We chose Penicillium brevicompactum as a model system to demonstrate the performance of our LIPUS system. Penicillium brevicompactum can produce mycophenolic acid (MPA), an immunosuppressive agent commonly used to prevent rejection after organ transplantation. We have stimulated Penicillium brevicompactum in 50 mL shake flasks using LIPUS during its fermentation. After a series of screening experiments to optimize ultrasound parameters (e.g., ultrasound intensities, treatment duration and treatment frequency per day), it was concluded that ultrasound stimulation can increase MPA production by as much as 60% when treated eight times a day for 10-min durations at an intensity (spatial peak temporal average) of 200 mW/cm(2). These findings elucidate a new approach to reduce the cost of producing fermentation-based drugs. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  19. Endurance training for elderly women: moderate vs low intensity.

    PubMed

    Foster, V L; Hume, G J; Byrnes, W C; Dickinson, A L; Chatfield, S J

    1989-11-01

    This investigation evaluated the efficacy of training at moderate-60% Maximal Heart Rate Reserve, HRRmax, (MOD) and low-40% HRRmax (LOW) intensities in a population of older American women (N = 16, mean age = 78.4 years). Prior to and immediately following a 10-week training program consisting of exercising at the prescribed heart-rate intensity with a caloric expenditure of 100 calories, the following measurements were performed: Maximal oxygen consumption (VO2max), Maximal Lactate Production (HLAmax), Maximal Heart Rate (HRmax), Maximal Workstage (WSmax), Total Cholesterol (TOTC), High Density Lipoprotein Cholesterol (HDLC), and Rate Pressure Product Max (RPPmax). Significant differences, p less than .05, were noted pre- to post-training for measures of VO2max, whether expressed in 1.min-1 or ml.kg-1.min-1, and WSmax. No statistical differences existed between the groups pre- or post-training for these measures. The results suggest that the low-intensity exercise prescription provides an adequate training stimulus for older women who have been sedentary and who might be at higher risk for cardiac or musculoskeletal injury, particularly at the initiation of an exercise program.

  20. Effects of caffeine on performance of low intensity tasks.

    PubMed

    Scott, William H; Coyne, Karen M; Johnson, Monique M; Lausted, Christopher G; Sahota, Manjit; Johnson, Arthur T

    2002-04-01

    31 college age men and women who consume less than three caffeinated beverages per week agreed to participate as subjects in research on the effects of acute caffeine intake on low intensity task performance. All subjects performed two randomly administered test conditions: (1) caffeine (5 mg/kg) and (2) placebo on separate visits following an initial 1-hr. orientation visit. Subjects were administered the beverage 30 min. prior to performing 12 separate tests assessing basic mathematics, simple response, logical reasoning, hand-eye coordination, and spatial and assembly skills. The Spielberger State Anxiety test was administered immediately after consuming the test beverage and once again at posttest. Analysis showed that caffeine did not significantly affect performance on all tests with the exception of the peripheral awareness (hand-eye coordination) test on which performance was higher after ingesting caffeine. The placebo treatment produced no effect on state anxiety, which contrasted with a significant rise in anxiety after caffeine consumption. State anxiety values were significantly greater after caffeine treatment relative to the placebo at pretest, and this difference persisted at posttest. These results demonstrated that the dose of caffeine increased scores on state anxiety for individuals who consumed less than three caffeinated beverages weekly but had very little effect on performance of low intensity tasks, except for a hand-eye coordination test involving peripheral awareness. Perhaps longer continuous performance of more demanding tasks would be more sensitive.

  1. Pulse Doppler ultrasound as a tool for the diagnosis of chronic testicular dysfunction in stallions

    PubMed Central

    Ortiz-Rodriguez, Jose M.; Anel-Lopez, Luis; Martín-Muñoz, Patricia; Álvarez, Mercedes; Gaitskell-Phillips, Gemma; Anel, Luis; Rodríguez-Medina, Pedro; Peña, Fernando J.

    2017-01-01

    values (high vascular perfusion). In contrast, subfertile stallions tend to present high values of PI and RI (high vascular resistance). The ROC curves revealed that the best Doppler parameters to predict sperm quality in stallions were: Doppler velocities (PSV, EDV and TAMV), the diameter of the capsular artery and TABF parameters (tissue perfusion parameters). Cut off values were established using a Youden´s Index to identify fertile stallions from stallions with testicular dysfunction. Spectral Doppler ultrasound is a good predictive tool for sperm quality since correlations were determined among Doppler parameters and markers of sperm quality. Doppler ultrasonography could be a valuable diagnostic tool for use by clinical practitioners for the diagnosis of stallions with testicular dysfunction and could be a viable alternative to invasive procedures traditionally used for diagnosis of sub-fertility disorders. PMID:28558006

  2. Pulsed counter-current ultrasound-assisted extraction and characterization of polysaccharides from Boletus edulis.

    PubMed

    You, Qinghong; Yin, Xiulian; Ji, Chaowen

    2014-01-30

    Four methods for extracting polysaccharides from Boletus edulis, namely, hot-water extraction, ultrasonic clearer extraction, static probe ultrasonic extraction, and pulsed counter-current probe ultrasonic extraction (CCPUE), were studied. Results showed that CCPUE has the highest extraction efficiency among the methods studied. Under optimal CCPUE conditions, a B. edulis polysaccharide (BEP) yield of 8.21% was obtained. Three purified fractions, BEP-I, BEP-II, and BEP-III, were obtained through sequential purification by DEAE-52 and Sephadex G-75 chromatography. The average molecular weights of BEP-I, BEP-II, and BEP-III were 10,278, 23,761, and 42,736 Da, respectively. The polysaccharides were mainly composed of xylose, mannose, galactose, and glucose; of these, mannose contents were the highest. The antioxidant activities of the BEPs were further investigated by measurement of their ability to scavenge DPPH and hydroxyl radicals as well as their reducing power. The results indicated that the BEPs have good antioxidant activity.

  3. Improved Estimation of Ultrasound Thermal Strain Using Pulse Inversion Harmonic Imaging

    PubMed Central

    Ding, Xuan; Nguyen, Man; James, Isaac; Marra, Kacey; Rubin, J. Peter; Leers, Steven A.; Kim, Kang

    2016-01-01

    Thermal (temporal) strain imaging (TSI) is being developed to detect the lipid rich core of atherosclerotic plaques and fatty liver disease. However, the effects of ultrasonic clutter on TSI have not been considered. In this study, we evaluated whether pulse inversion harmonic imaging (PIHI) could be used to improve estimates of thermal (temporal) strains. Using mixed castor oil-gelatin phantoms of different concentrations and artificially introduced clutter, we showed that PIHI improved the signal-to-noise ratio of TSI by an average of 213% or 52.1% as compared to 3.3 MHz and 6.6 MHz imaging. In a phantom constructed using human liposuction fat in the presence of clutter, the contrast-to-noise ratio was degraded by 35.1% for PIHI as compared to 62.4% and 43.7% for 3.3 MHz and 6.6 MHz imaging, respectively. These findings were further validated using an ex vivo carotid endarterectomy sample. PIHI can be used to improve estimates of thermal (temporal) strain in the presence of clutter. PMID:26948260

  4. Exploration and Practice in Photoacoustic Measurement for Glucose Concentration Based on Tunable Pulsed Laser Induced Ultrasound

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen; Zhao, Dengji; Xiong, Zhihua

    2015-07-01

    In this article, a tunable pulsed laser induced photoacoustic measurement setup of monitoring glucose concentration was established in the forward mode. In experiments, the time-resolved photoacoustic signal of glucose aqueous solution with different concentrations of 0-300 mg/dl were captured and averaged 512 times, and the photoacoustic peak-to-peak values were recorded using the wavelength scan in NIR region of 1300-2300 nm. The optimal characteristic wavelengths of glucose were determined via the difference spectral and the first derivative spectral algorithm, and correction models between peak-to-peak values of optimal wavelengths and concentration gradients were established using multivariate linear regression algorithm. Experimental results demonstrated that the profile and logarithm shape of time-resolved photoacoustic signal for glucose solutions were in good agreement with photoacoustic theories. The prediction effect of optimal wavelength of 1510 nm was best, its root-mean-square errors of correction and prediction were 12.14 and 8.45 mg/dl, respectively, the correlation coefficient reached 0.9856.

  5. Modern spectral analysis techniques for blood flow velocity and spectral measurements with pulsed Doppler ultrasound.

    PubMed

    David, J Y; Jones, S A; Giddens, D P

    1991-06-01

    Four spectral analysis techniques were applied to pulsed Doppler ultrasonic quadrature signals to compare the relative merits of each technique for estimation of flow velocity and Doppler spectra. The four techniques were 1) the fast Fourier transform method, 2) the maximum likelihood method, 3) the Burg autoregressive algorithm, and 4) the modified covariance approach to autoregressive modeling. Both simulated signals and signals obtained from an in vitro flow system were studied. Optimal parameter values (e.g., model orders) were determined for each method, and the effects of signal-to-noise ratio and signal bandwidth were investigated. The modern spectral analysis techniques were shown to be superior to Fourier techniques in most circumstances, provided the model order was chosen appropriately. Robustness considerations tended to recommend the maximum likelihood method for both velocity and spectral estimation. Despite the restrictions of steady laminar flow, the results provide important basic information concerning the applicability of modern spectral analysis techniques to Doppler ultrasonic evaluation of arterial disease.

  6. Ultrasound physics.

    PubMed

    Shriki, Jesse

    2014-01-01

    Bedside ultrasound has become an important modality for obtaining critical information in the acute care of patients. It is important to understand the physics of ultrasound in order to perform and interpret images at the bedside. The physics of both continuous wave and pulsed wave sound underlies diagnostic ultrasound. The instrumentation, including transducers and image processing, is important in the acquisition of appropriate sonographic images. Understanding how these concepts interplay with each other enables practitioners to obtain the best possible images. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. [Experimental justification of possible mechanisms of action of low intensity electromagnetic radiation (EMR) on animals' behavior].

    PubMed

    Pavlov, L N; Dubrovik, B V; Zhavoronkov, l P; Glushakova, V S

    2012-01-01

    Effects of EMR on the behavior of Wistar rats (196 males, 180-240 g of mass) under the conflict of opposed motivations: strong positive, drinking, motivation, and strong negative, pain, motivation were studied. The animals were exposed to low intensity EMR (40 microW/cm2) produced by two independent sources, 475 MHz (Albatross) with two orthogonal E vectors, and synchronization of rhythm modulation in the range of electroencephalography (EEG) frequency. The effect on behavior was observed during 10 min: 1) following the 5-minute exposure to EMR and 2) during the 10-minute exposure. Low intensity EMR of the above mentioned parameters and pulse modulation of 4, 8, 10 and 13 Hz was found to inhibit development of phobia to pain, increase the number of punishable contacts. It testifies to the existence of a weak anxiolytic effect which is similar to the effect of tranquilizers. If animals were exposed to EMR following administration of phenazepam, the radiation was shown to produce potentiation of the anxiolytic effect ofphenazepam. Effect of phenazepam is associated with activation ofbenzdiazipine receptors in the structure ofGABA-ergic receptor complex, which regulates neural membrane chloride channel conductance. We can suggest that anxiolytic and neurodepressive effects of EMR are realized to some extent at the level of ionophore and regulatory receptor complexes.

  8. Influence of Laser Irradiation Low Intensity on Reparative Osteogenesis and Angiogenesis Under Transosseous Osteosynthesis

    PubMed Central

    Iryanov, Yuri Mikhailovich

    2016-01-01

    Introduction: The use of non-medicinal facilities of correcting processes for various pathological conditions is one of the most urgent problems of modern medicine. The purpose of the work is to study the efficiency of low-intensive of infrared laser irradiation in promoting reparative osteogenesis and angiogenesis during fracture treatment under transosseous osteosynthesis with a qualitative and quantitative morphological analysis. Methods: A tibial fracture was modeled experimentally in rats from control and experimental groups, then repositioning and fixation of fragments performed. The fracture zone of the experimental group animals was exposed to pulsed infrared laser irradiation of low intensity. The animals from control group underwent irradiation simulation. The operated bones were investigated using x-ray, light and electron microscopy, x-ray electron probe microanalysis. Results: The sessions of laser irradiation decreased inflammatory process severity, activated fibrillogenesis and angiogenesis, accelerated the compactization of newly formed bone tissue, and enhanced its maturity degree while primary healing occurred in the fracture. Conclusion: Laser therapy of fracture zone ensures the formation of regenerated bone and fragment union within earlier periods. PMID:28144431

  9. Nonlinear simultaneous reconstruction of inhomogeneous compressibility and mass density distributions in unidirectional pulse-echo ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Hesse, Markus C.; Salehi, Leili; Schmitz, Georg

    2013-09-01

    In diagnostic ultrasound imaging, the image reconstruction quality is crucial for reliable diagnosis. Applying reconstruction algorithms based on the acoustic wave equation, the obtained image quality depends significantly on the physical material parameters accounted for in the equation. In this contribution, we extend a proposed iterative nonlinear one-parameter compressibility reconstruction algorithm by the additional reconstruction of the object’s inhomogeneous mass density distribution. The improved iterative algorithm is able to reconstruct inhomogeneous maps of the object’s compressibility and mass density simultaneously using only one conventional linear transducer array at a fixed location for wave transmission and detection. The derived approach is based on an acoustic wave equation including spatial compressibility and mass density variations, and utilizes the Kaczmarz method for iterative material parameter reconstruction. We validate our algorithm numerically for an unidirectional pulse-echo breast imaging application, and thus generate simulated measurements acquired from a numerical breast phantom with realistic compressibility and mass density values. Applying these measurements, we demonstrate with two reconstruction experiments the necessity to calculate the mass density in case of tissues with significant mass density inhomogeneities. When reconstructing spatial mass density variations, artefacts in the breast’s compressibility image are reduced resulting in improved spatial resolution. Furthermore, the compressibility relative error magnitude within a diagnostically significant region of interest (ROI) decreases from 3.04% to 2.62%. Moreover, a second image showing the breast’s inhomogeneous mass density distribution is given to provide additional diagnostic information. In the compressibility image, a spatial resolution moderately higher than the classical half-wavelength limit is observed.

  10. Enhanced Therapeutic Epidermal Growth Factor Receptor (EGFR) Antibody Delivery via Pulsed Ultrasound with Targeting Microbubbles for Glioma Treatment.

    PubMed

    Liao, Ai-Ho; Chou, Hsin-Yi; Hsieh, Yi-Lei; Hsu, Sheng-Chieh; Wei, Kuo-Chen; Liu, Hao-Li

    Pulsed-mode ultrasound (pUS) in combination with intravenously (IV) administered microbubbles (MBs) can enhance local drug delivery by temporarily enhancing capillary permeability. This study evaluates the use of epidermal growth factor receptor (EGFR)-targeting MBs after pUS treatment to enhance the effects of therapeutic-EGFR antibody delivery to glioma tumor cells in mice. Three animal groups were compared: (1) IV-injected non-targeting MBs, (2) IV-injected targeting MBs, and (3) IV-injected targeting MBs combined with pUS treatment. All animals were analyzed using high-frequency small-animal US imaging. The mean halftime of circulating targeting MBs was significantly increased from 3.13 min of targeting bubble alone to 5.86 min by targeting MBs combined with pUS treatment, compared to 2.34 min for non-targeting MBs. Compared to targeting bubble administration alone, pUS exposure prior to injection of targeting MBs was also significantly better at suppressing tumor growth when monitored for up to 35 days (p < 0.05). The final relative tumor volumes were 2664, 700, and 188 mm(3) for non-targeting MBs, targeting MBs, and targeting MBs combined with pUS treatment, respectively. pUS treatment prolonged the mean circulatory halftime of targeting MBs and enhanced the anti-tumor effect of EGFR antibodies in a human glioma model in mice. Targeting MBs combined with pUS treatment thus has potential for enhanced therapeutic antibody delivery for facilitating anti-glioma treatment.

  11. Nonlinear simultaneous reconstruction of inhomogeneous compressibility and mass density distributions in unidirectional pulse-echo ultrasound imaging.

    PubMed

    Hesse, Markus C; Salehi, Leili; Schmitz, Georg

    2013-09-07

    In diagnostic ultrasound imaging, the image reconstruction quality is crucial for reliable diagnosis. Applying reconstruction algorithms based on the acoustic wave equation, the obtained image quality depends significantly on the physical material parameters accounted for in the equation. In this contribution, we extend a proposed iterative nonlinear one-parameter compressibility reconstruction algorithm by the additional reconstruction of the object's inhomogeneous mass density distribution. The improved iterative algorithm is able to reconstruct inhomogeneous maps of the object's compressibility and mass density simultaneously using only one conventional linear transducer array at a fixed location for wave transmission and detection. The derived approach is based on an acoustic wave equation including spatial compressibility and mass density variations, and utilizes the Kaczmarz method for iterative material parameter reconstruction. We validate our algorithm numerically for an unidirectional pulse-echo breast imaging application, and thus generate simulated measurements acquired from a numerical breast phantom with realistic compressibility and mass density values. Applying these measurements, we demonstrate with two reconstruction experiments the necessity to calculate the mass density in case of tissues with significant mass density inhomogeneities. When reconstructing spatial mass density variations, artefacts in the breast's compressibility image are reduced resulting in improved spatial resolution. Furthermore, the compressibility relative error magnitude within a diagnostically significant region of interest (ROI) decreases from 3.04% to 2.62%. Moreover, a second image showing the breast's inhomogeneous mass density distribution is given to provide additional diagnostic information. In the compressibility image, a spatial resolution moderately higher than the classical half-wavelength limit is observed.

  12. Pulsed focused ultrasound pretreatment improves mesenchymal stem cell efficacy in preventing and rescuing established acute kidney injury in mice

    PubMed Central

    Burks, Scott R.; Nguyen, Ben A.; Tebebi, Pamela A.; Kim, Saejeong J.; Bresler, Michele N.; Ziadloo, Ali; Street, Jonathan M.; Yuen, Peter S. T.; Star, Robert A.; Frank, Joseph A.

    2014-01-01

    Animal studies have shown that mesenchymal stem cell (MSC) infusions improve acute kidney injury (AKI) outcomes when administered early after ischemic/reperfusion injury or within 24hr after cisplatin administration. These findings have spurred several human clinical trials to prevent AKI. However, no specific therapy effectively treats clinically obvious AKI or rescues renal function once advanced injury is established. We investigated if noninvasive image-guided pulsed focused ultrasound (pFUS) could alter the kidney microenvironment to enhance homing of subsequently infused MSC. To examine the efficacy of pFUS-enhanced cell homing in disease, we targeted pFUS to kidneys to enhance MSC homing after cisplatin-induced AKI. We found that pFUS enhanced MSC homing at 1 day post-cisplatin, prior to renal functional deficits, and that enhanced homing improved outcomes of renal function, tubular cell death, and regeneration at 5 days post-cisplatin compared to MSC alone. We then investigated whether pFUS+MSC therapy could rescue established AKI. MSC alone at 3 days post-cisplatin, after renal functional deficits were obvious, significantly improved 7-day survival of animals. Survival was further improved using pFUS+MSC. MSC, alone or with pFUS, changed kidney macrophage phenotypes from M1 to M2. This study shows pFUS is a neoadjuvant approach to improve MSC homing to diseased organs. pFUS with MSC better prevents AKI than MSC alone and allows rescue therapy in established AKI, which currently has no meaningful therapeutic options. PMID:25640064

  13. Improving the therapeutic efficacy of mesenchymal stromal cells to restore perfusion in critical limb ischemia through pulsed focused ultrasound.

    PubMed

    Tebebi, Pamela A; Kim, Saejeong J; Williams, Rashida A; Milo, Blerta; Frenkel, Victor; Burks, Scott R; Frank, Joseph A

    2017-02-07

    Mesenchymal stem cells (MSC) are promising therapeutics for critical limb ischemia (CLI). Mechanotransduction from pulsed focused ultrasound (pFUS) upregulates local chemoattractants to enhance homing of intravenously (IV)-infused MSC and improve outcomes. This study investigated whether pFUS exposures to skeletal muscle would improve local homing of iv-infused MSCs and their therapeutic efficacy compared to iv-infused MSCs alone. CLI was induced by external iliac arterial cauterization in 10-12-month-old mice. pFUS/MSC treatments were delayed 14 days, when surgical inflammation subsided. Mice were treated with iv-saline, pFUS alone, IV-MSC, or pFUS and IV-MSC. Proteomic analyses revealed pFUS upregulated local chemoattractants and increased MSC tropism to CLI muscle. By 7 weeks post-treatment, pFUS + MSC significantly increased perfusion and CD31 expression, while reducing fibrosis compared to saline. pFUS or MSC alone reduced fibrosis, but did not increase perfusion or CD31. Furthermore, MSCs homing to pFUS-treated CLI muscle expressed more vascular endothelial growth factor (VEGF) and interleukin-10 (IL-10) than MSCs homing to non-pFUS-treated muscle. pFUS + MSC improved perfusion and vascular density in this clinically-relevant CLI model. The molecular effects of pFUS increased both MSC homing and MSC production of VEGF and IL-10, suggesting microenvironmental changes from pFUS also increased potency of MSCs in situ to further enhance their efficacy.

  14. Improving the therapeutic efficacy of mesenchymal stromal cells to restore perfusion in critical limb ischemia through pulsed focused ultrasound

    PubMed Central

    Tebebi, Pamela A.; Kim, Saejeong J.; Williams, Rashida A.; Milo, Blerta; Frenkel, Victor; Burks, Scott R.; Frank, Joseph A.

    2017-01-01

    Mesenchymal stem cells (MSC) are promising therapeutics for critical limb ischemia (CLI). Mechanotransduction from pulsed focused ultrasound (pFUS) upregulates local chemoattractants to enhance homing of intravenously (IV)-infused MSC and improve outcomes. This study investigated whether pFUS exposures to skeletal muscle would improve local homing of iv-infused MSCs and their therapeutic efficacy compared to iv-infused MSCs alone. CLI was induced by external iliac arterial cauterization in 10–12-month-old mice. pFUS/MSC treatments were delayed 14 days, when surgical inflammation subsided. Mice were treated with iv-saline, pFUS alone, IV-MSC, or pFUS and IV-MSC. Proteomic analyses revealed pFUS upregulated local chemoattractants and increased MSC tropism to CLI muscle. By 7 weeks post-treatment, pFUS + MSC significantly increased perfusion and CD31 expression, while reducing fibrosis compared to saline. pFUS or MSC alone reduced fibrosis, but did not increase perfusion or CD31. Furthermore, MSCs homing to pFUS-treated CLI muscle expressed more vascular endothelial growth factor (VEGF) and interleukin-10 (IL-10) than MSCs homing to non-pFUS-treated muscle. pFUS + MSC improved perfusion and vascular density in this clinically-relevant CLI model. The molecular effects of pFUS increased both MSC homing and MSC production of VEGF and IL-10, suggesting microenvironmental changes from pFUS also increased potency of MSCs in situ to further enhance their efficacy. PMID:28169278

  15. Pulse

    MedlinePlus

    ... the underside of the opposite wrist, below the base of the thumb. Press with flat fingers until ... determine if the patient's heart is pumping. Pulse measurement has other uses as well. During or immediately ...

  16. Low intensity X-ray and gamma-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Yin, L. I. (Inventor)

    1982-01-01

    A low intensity X-ray and gamma ray spectrometer for imaging, counting, and energy resolving of single invisible radiation particles is described. The spectrometer includes a converting device for converting single invisible radiation particles to visible light photons. Another converting device converts the visible light photons to photoelectrons. A fiber optics coupling device couples together the two converting devices. An intensifying device intensifies the photoelectrons by an average gain factor of between 10 to the 4th power and 10 to the 7th power. The tensifying device is an anti-ion feedback microchannel plate amplifier which is operated substantially below saturation. A displaying device displays the intensified photoelectrons. The displaying device 32 indicates the spatial position, number, and energy of the incoming single invisible radiation particles.

  17. Heating of blood by low-intensity laser radiation

    NASA Astrophysics Data System (ADS)

    Korolevich, Alexander N.; Astafyeva, Liudmila G.; Dubina, Natali S.; Vecherinski, Sergei I.; Belsley, Michael S.

    2003-10-01

    Theoretical and experimental studies of the influence of low-intensity laser radiation, on the velocity of microcirculation of the erythrocytes of patients with the cardiovascular disease "in vivo" are carried out. Dynamic light scattering techniques were used to monitor the variation in the perfusion of micro capillary blood flow during irradiation under "in vivo" conditions and compared to the change in average size of aggregates of the blood effects observed "in vitro" using static scattering of light. It is shown that the process of the fragmentation of erythrocytes depends on amount of energy absorbed by biological tissues. This conclusion is supported by the good qualitative agreement with the theoretical model, based on the heat transfer theory within the dermis.

  18. Low-intensity exercise, vascular occlusion, and muscular adaptations.

    PubMed

    Teramoto, Masaru; Golding, Lawrence A

    2006-01-01

    The study investigated the effects of low-intensity exercise on muscular fitness when combined with vascular occlusion. Nineteen college male and female students performed two sets of a 5-min step exercise using a 12-inch bench three times per week for 5 weeks. During the step exercise, blood flow to one leg was restricted (vascular occlusion) with a blood pressure cuff, while the other leg was not occluded. Muscular strength of the occluded leg was significantly increased over the nonoccluded leg (p < 0. 05). Muscular endurance and muscle mass were improved after 5 weeks of training (p < 0.05); however, the changes between the two legs were not significantly different (p > 0.05). Exercise with vascular occlusion has the potential to be an alternative form of training to promote muscular strength.

  19. Basic studies on intravascular low-intensity laser therapy

    NASA Astrophysics Data System (ADS)

    Liu, Timon Cheng-Yi; Duan, Rui; Wang, Shuang-Xi; Liu, Jiang; Cui, Li-Ping; Jin, Hua; Liu, Song-Hao

    2006-09-01

    Intravascular low intensity laser therapy (ILILT) was originally put forward in USA in 1982, but popularized in Russia in 1980s and in China in 1990s, respectively. A randomized placebo-controlled study has shown ILILT clinical efficacy in patients suffering from rheumatoid arthritis. As Chinese therapeutic applications of ILILT were the most widely in the world, its basic research, such as intracellular signal transduction research, blood research in vitro, animal blood research in vivo, human blood research in vivo and traditional Chinese medicine research, was also very progressive in China. Its basic studies will be reviewed in terms of the biological information model of photobiomodulation in this paper. ILILT might work in view of its basic studies, but the further randomized placebo-controlled trial and the further safety research should be done.

  20. Adaptations of mouse skeletal muscle to low intensity vibration training

    PubMed Central

    McKeehen, James N.; Novotny, Susan A.; Baltgalvis, Kristen A.; Call, Jarrod A.; Nuckley, David J.; Lowe, Dawn A.

    2013-01-01

    Purpose We tested the hypothesis that low intensity vibration training in mice improves contractile function of hindlimb skeletal muscles and promotes exercise-related cellular adaptations. Methods We subjected C57BL/6J mice to 6 wk, 5 d·wk−1, 15 min·d−1 of sham or low intensity vibration (45 Hz, 1.0 g) while housed in traditional cages (Sham-Active, n=8; Vibrated-Active, n=10) or in small cages to restrict physical activity (Sham-Restricted, n=8; Vibrated-Restricted, n=8). Contractile function and resistance to fatigue were tested in vivo (anterior and posterior crural muscles) and ex vivo on the soleus muscle. Tibialis anterior and soleus muscles were evaluated histologically for alterations in oxidative metabolism, capillarity, and fiber types. Epididymal fat pad and hindlimb muscle masses were measured. Two-way ANOVAs were used to determine effects of vibration and physical inactivity. Results Vibration training resulted in a 10% increase in maximal isometric torque (P=0.038) and 16% faster maximal rate of relaxation (P=0.030) of the anterior crural muscles. Posterior crural muscles were unaffected by vibration, with the exception of greater rates of contraction in Vibrated-Restricted mice compared to Vibrated-Active and Sham-Restricted mice (P=0.022). Soleus muscle maximal isometric tetanic force tended to be greater (P=0.057) and maximal relaxation was 20% faster (P=0.005) in Vibrated compared to Sham mice. Restriction of physical activity induced muscle weakness but was not required for vibration to be effective in improving strength or relaxation. Vibration training did not impact muscle fatigability or any indicator of cellular adaptation investigated (P≥0.431). Fat pad but not hindlimb muscle masses were affected by vibration training. Conclusion Vibration training in mice improved muscle contractility, specifically strength and relaxation rates, with no indication of adverse effects to muscle function or cellular adaptations. PMID:23274599

  1. Integrated Heterodyne MOEMS for detection of low intensity signals

    NASA Astrophysics Data System (ADS)

    Elman, Noel M.; Krylov, Slava; Sternheim, Marek; Shacham-Diamand, Yosi

    2006-01-01

    A novel MEMS-based modulation scheme is presented as a method to enhance the signal-to-noise ratio (SNR) of silicon photodiodes adapted for the detection of light-emitting bio-reporter signals. Photodiodes are an attractive photodetector choice because they are VLSI compatible, easily miniaturized, highly scalable, and inexpensive. Silicon photodiodes exhibit a wide response range extending from the ultraviolet (UV) to the near infrared (IR) part of the spectrum, which in principle is appropriate for sensing low intensity optical signals. Silicon photodiodes, however, exhibit limited sensitivity to optical dc signals, as the magnitude of the low frequency noise is comparable to signal magnitude. Optical modulation prior to photodetection overcomes the inherent low frequency noise of photodetectors and system detection circuits. The enhancement scheme is based on a design of high frequency optical modulators that operate in the 1-2 kHz range in order to overcome the low frequency spectral noise. We have denominated this MEMS-based scheme Integrated Heterodyne Optical System (IHOS). The modulation efficiency of the proposed architecture can reach up to 50 percent. In order to implement the MOEMS optical modulators, a new two-mask fabrication process was developed that combines high-aspect ratio and low aspect ratio structures at the same device layer (aspect ratio is defined as a ratio between the structure height to its width). Long stroke electrostatic combdrive actuators integrated with folded flexures (high aspect-ratio) were fabricated together to drive large aperture shutters (low aspect ratio). We have denominated this process MASIS (Multiple Aspect Ratio Structural Integration). Under resonant excitation at approximately 1 kHz, MOEMS modulators demonstrated maximum displacement of about 40 microns at an actuation voltage of 15 V peak in air, and 3.5 V peak in vacuum (8 mTorr). Results of analytical solutions and finite element analysis (FEA) simulations are

  2. Low-intensity treadmill exercise promotes rat dorsal wound healing.

    PubMed

    Zhou, Wu; Liu, Guo-hui; Yang, Shu-hua; Mi, Bo-bin; Ye, Shu-nan

    2016-02-01

    In order to investigate the promoting effect of low-intensity treadmill exercise on rat dorsal wound healing and the mechanism, 20 Sprague-Dawley rats were randomly divided into two groups: exercise group (Ex) and non-exercise group (non-ex). The rats in Ex group were given treadmill exercise for one month, and those in non-ex group raised on the same conditions without treadmill exercise. Both groups received dorsal wound operation with free access to food and water. By two-week continuous observation and recording of the wound area, the healing rate was analyzed. The blood sample was collected at day 14 post-operation via cardiac puncture for determination of the number of endothelial progenitor cells (EPCs) by flow cytometry, and the concentrations of relevant cytokines such as basic fibroblast growth factor (bFGF), endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) were measured by ELISA. The skin tissue around the wound was dissected to observe the vascular density under the microscope after HE staining, to detect the mRNA level of VEGFR2 and angiopoietin-1 (Ang-1) receptor using RT-qPCR, and protein expression of a-smooth muscle actin (αSMA) and type III collagen (ColIII) using Western blotting. It was found that the wound area in Ex group was smaller at the same time point than in non-ex group. The number of circulating EPCs was greater and the concentrations of vasoactive factors such as VEGF, eNOS and bFGF were higher in Ex group than in non-ex group. HE staining displayed a higher vessel density in Ex group than in non-ex group. Moreover, the mRNA expression of VEGFR2 and Ang-1 detected in the wound tissue in Ex group was higher than in non-ex group. Meanwhile, the protein expression of αSMA and ColIII was more abundant in Ex group than in non-ex group. Conclusively, the above results demonstrate Ex rats had a higher wound healing rate, suggesting low-intensity treadmill exercise accelerates wound healing. The present

  3. Intensification of Enzymatic Bio-Processing of Cotton by Low Intensity Uniform Ultrasound Field

    USDA-ARS?s Scientific Manuscript database

    Use of enzymatic processing in textile applications is becoming increasingly popular, primarily because of rapid introduction of a new variety of highly efficient enzymes. In general, enzymatic bio-processing generates less toxic and readily biodegradable wastewater effluents. However, enzymatic bio...

  4. Acceleration of the Enzymatic Hydrolysis of Cotton Waste Celluloses by Low Intensity Uniform Ultrasound Field

    USDA-ARS?s Scientific Manuscript database

    The cost-competitive production of bio-ethanol and other biofuels is currently impeded, mostly by high cost and low efficiency of enzymatic hydrolysis of feedstock biomass and especially plant celluloses. Despite substantial reduction in the cost of production of cellulolytic enzymes in recent times...

  5. Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Tsuneda, H.; Matsukawa, S.; Takayanagi, S.; Mizuno, K.; Yanagitani, T.; Matsukawa, M.

    2015-02-01

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity.

  6. Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    SciTech Connect

    Tsuneda, H.; Matsukawa, S.; Takayanagi, S.; Matsukawa, M.; Mizuno, K.; Yanagitani, T.

    2015-02-16

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity.

  7. Immunomodulating action of low intensity millimeter waves on primed neutrophils.

    PubMed

    Safronova, Valentina G; Gabdoulkhakova, A G; Santalov, B F

    2002-12-01

    Comparative investigation of the susceptibility of intact and primed neutrophils of the NMRI strain mice to low intensity millimeter wave (mm wave) irradiation (41.95 GHz) was performed. The specific absorption rate was 0.45 W/kg. Isolated neutrophils were primed by a chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) at a subthreshold concentration of 10 nM for 20 min, and then the cells were activated by 1 microM fMLP. Production of the reactive oxygen species (ROS) was estimated by the luminol dependent chemiluminescence technique. It was found that the preliminary mm wave irradiation of the resting cells at 20 degrees C did not act on the ROS production induced by the chemotactic peptide. The exposure of the primed cells results in a subsequent increase in the fMLP response. Therefore, the primed neutrophils are susceptible to the mm waves. Specific inhibitors of the protein kinases abolished the mm wave effect on the primed cells. The data indicate that protein kinases actively participate in transduction of the mm wave signal to effector molecules involved in neutrophil respiratory burst.

  8. Psychological effects of low intensity conflict (LIC) operations

    PubMed Central

    Chaudhury, Suprakash; Goel, D.S.; Singh, Harcharan

    2006-01-01

    Background: A burgeoning clinical and empirical literature has provided incontrovertible evidence that combat operations exact a heavy toll in terms of human suffering not only on combatants but also military support personnel. Though the Indian army is engaged in low intensity conflict (LIC) operations for over five decades, the psychological effects of LIC deployment on soldiers have not been adequately studied. Aims: To evaluate the psychological effects of deployment in LIC operations on service personnel. Methods: Five hundred and sixty-eight servicemen engaged in LIC operations and equal number of age- and rank-matched personnel in adjoining peace areas were evaluated with a self-made questionnaire, General Health Questionnaire (GHQ), Carroll Rating Scale for Depression (CRSD), State-Trait Anxiety Inventory (STAI), Michigan Alcoholism Screening Test (MAST), Impact of Events Scale (IES), Perceived Stress Questionnaire (PSQ), Multidimensional Fatigue Inventory (MFI), Hindi PEN inventory, Satisfaction With Life Scale (SWLS) and Locus Of Control (LOC) scale. Results: Respondents from LIC area had significantly higher scores on CRSD, MAST, GHQ, IES, and general fatigue, physical fatigue, and mental fatigue subscale of the MFI in comparison to those located in other areas. Significantly higher number of respondents from highly active LIC and with more than one-year service in LIC scored above cut-off levels on CRSD, MAST and GHQ. Conclusions: The psychological status of troops was directly related both to the duration of stay and the nature of LIC area. PMID:20703341

  9. Laser cooling at low intensity in a strong magnetic field

    NASA Astrophysics Data System (ADS)

    van der Straten, P.; Shang, S.-Q.; Sheehy, B.; Metcalf, H.; Nienhuis, G.

    1993-05-01

    We have studied theoretically and experimentally the effect of a relatively strong magnetic field on sub-Doppler laser cooling in a one-dimensional optical molasses. We used the operator description of laser cooling with the Larmor precession frequency ωZ being much higher than the optical pumping rate. We found velocity-selective resonances (VSR) in the force at velocities vr=nωZ, with n=0,+/-1,+/-2 for both the scattering and redistribution force operators. These depend on the relative direction of the magnetic field and the polarization vectors of the light beams. Analytical results for the force on the atom are obtained in two cases that illustrate the effect of the VSR on the force. These formulas are compared with numerical calculations of the force. We also discovered a redistribution mechanism that relies on the gradient of the eigenstates of the light-shift operator, with eigenvalues that are independent of position so that a ``Sisyphus cooling'' picture does not apply. The theory is compared with many experimental results and excellent agreement is found. We believe that all essential features of laser cooling at low intensity are well described by this operator theory.

  10. (abstract) PV Technology for Low Intensity, Low Temperature (LILT) Applications

    NASA Technical Reports Server (NTRS)

    Stella, Paul M.; Pool, Frederick S.; Nicolet, Marc A.; Iles, Peter A.

    1994-01-01

    As a result of the recent NASA emphasis on smaller, lower cost space missions, PV is now being considered for a number of missions operating at solar distances of 3 AU or greater. In the past, many of these missions would utilize an RTG (radioisotope thermoelectric generator). Historically, silicon solar cell behavior at these distances has been compromised by a number of mechanisms including shunting, nonohmic back contacts, and the 'broken knee' curve shape. The former two can usually be neglected for modern silicon cells, but the latter has not been eliminated. This problem has been identified with localized diffusion at the top contact/silicon interface which leads to structural changes at the local junction. This is believed to create a resistive metal-semiconductor-like (MSL) interface in parallel with the junction which results in the characteristic forms of the LILT (low intensity, low temperature) 'broken knee'. This paper discusses a TaSiN contact barrier that will prevent the MSL structure in the junction.

  11. PV Technology for Low Intensity, Low Temperature (LILT) Applications

    NASA Technical Reports Server (NTRS)

    Stella, Paul M.; Pool, Frederick S.; Nicolet, Marc A.; Iles, Peter A.

    1994-01-01

    As a result of the recent NASA emphasis on smaller, lower cost space missions, PV is now being considered for a number of missions operating at solar distances of 3 AU or greater. In the past, many of these missions would utilize an RTG (radioisotope thermoelectric generator). Historically, silicon solar cell behavior at these distances has been compromised by a number of mechanisms including shunting, nonohmic back contacts, and the 'broken knee' curve shape. The former two can usually be neglected for modern silicon cells, but the latter has not been eliminated. This problem has been identified with localized diffusion at the top contact/silicon interface which leads to structural changes at the local junction. This is believed to create a resistive metal-semiconductor-like (MSL) interface in parallel with the junction which results in the characteristic forms of the LILT (low intensity, low temperature) 'broken knee'. This paper discusses a TaSiN contact barrier that will prevent the MSL structure in the junction.

  12. Low Intensity Laser Therapy Applied in the Healing of Wounds

    NASA Astrophysics Data System (ADS)

    Kahn, Fred; Matthews, Jeffrey

    2009-06-01

    Objective: The aim of this study was to determine the outcomes of Low Intensity Laser Therapy (LILT) on wound healing for patients presenting with pain, compromised neurological and physical function and tissue damage associated with vascular/diabetic ulcerations of the lower extremity. Methods: A retrospective case review of six patients treated with LILT (GaAlAs SLD, 660 nm, 750 mW, 3.6 J/cm2; GaAlAs SLD, 840 nm, 1,500 mW, 6.48 J/cm2; GaAlAs laser, 830 nm, 75 mW, 270 J/cm2) was conducted of clinical features including pain, measured by visual analogue scale (VAS), motor function, measured by range of motion (ROM) and visual outcome, measured by wound dimensions for six patients (n = 6; 5 males, 1 female; age = 67.83 years). Results: Significant progress with regard to alleviation of pain (ΔVAS = -5), improvements in motor function (ΔROM = +40%), epithelialization (wound closure rate = 3%/week) and complete wound closure was achieved. No recurrence of pathology at least one month post cessation of therapy was evident (x¯% reduction in wound area = 100%). Conclusions: LILT achieved consistent, effective and clear endpoints, was cost effective, created no adverse effects and ultimately led to the salvage of extremities.

  13. No effect of bipolar interferential electrotherapy and pulsed ultrasound for soft tissue shoulder disorders: a randomised controlled trial

    PubMed Central

    van der Heijden, G. J M G; Leffers, P.; Wolters, P.; Verheijden, J.; van Mameren, H.; Houben, J.; Bouter, L.; Knipschild, P.

    1999-01-01

    OBJECTIVE—To assess the efficacy of bipolar interferential electrotherapy (ET) and pulsed ultrasound (US) as adjuvants to exercise therapy for soft tissue shoulder disorders (SD).
METHODS—Randomised placebo controlled trial with a two by two factorial design plus an additional control group in 17 primary care physiotherapy practices in the south of the Netherlands. Patients with shoulder pain and/or restricted shoulder mobility, because of a soft tissue impairment without underlying specific or generalised condition, were enrolled if they had not recovered after six sessions of exercise therapy in two weeks. They were randomised to receive (1) active ET plus active US; (2) active ET plus dummy US; (3) dummy ET plus active US; (4) dummy ET plus dummy US; or (5) no adjuvants. Additionally, they received a maximum of 12 sessions of exercise therapy in six weeks. Measurements at baseline, 6 weeks and 3, 6, 9, and 12 months later were blinded for treatment. Outcome measures: recovery, functional status, chief complaint, pain, clinical status, and range of motion.
RESULTS—After written informed consent 180 patients were randomised: both the active treatments were given to 73 patients, both the dummy treatments to 72 patients, and 35 patients received no adjuvants. Prognosis of groups appeared similar at baseline. Blinding was successfully maintained. At six weeks seven patients (20%) without adjuvants reported very large improvement (including complete recovery), 17 (23%) and 16 (22%) with active and dummy ET, and 19 (26%) and 14 (19%) with active and dummy US. These proportions increased to about 40% at three months, but remained virtually stable thereafter. Up to 12 months follow up the 95% CI for differences between groups for all outcomes include zero.
CONCLUSION—Neither ET nor US prove to be effective as adjuvants to exercise therapy for soft tissue SD.

 PMID:10460185

  14. Sizing of Emboli in Flowing Blood Using Pulse Doppler Ultrasound and the Embolus-To Power Ratio.

    NASA Astrophysics Data System (ADS)

    Moehring, Mark Alan

    The embolus to blood ratio (EBR) theoretical model describing pulse Doppler ultrasound observations of emboli in flowing blood is summarized. The EBR model uses the backscattered signal power from blood in the Doppler sample volume as a reference from which to assess embolus size and composition. This EBR is independent of attenuation and reflection loss in intervening tissues between probe and bloodflow. An in vitro investigation is presented that tests the validity of the EBR model. The experimental apparatus includes a novel phantom for Doppler observation of circulating emboli and a Doppler system which uses 1.6 and 2.4 MHz concurrently for interrogation of an embolus. The phantom contains a tubeless flow conduit inside a polyacrylamide gel and a blood-mimicking fluid flowing in the conduit. Time series Doppler shift data which are gathered while polystyrene microsphere "emboli" transit the sample volume are post -processed to calculate the EBR on each embolic signature. EBR measurements from microspheres of three different diameters are summarized and shown to contain pronounced and systematic variability. The hypothesis is presented that this variability is due to a small speed of sound mismatch between the gel and the blood-mimicking fluid, a phenomenon anticipated in vivo. This speed of sound mismatch results in beam refraction and a non-uniformly insonated sample volume (thereby causing variability in embolus signatures). A three dimensional theoretical study is presented that models beam refraction resulting from speed of sound mismatch between the blood mimicking fluid and the surrounding gel. A Monte Carlo study of the EBR behavior in the presence of beam refraction is performed and yields similar results to the data obtained in vitro. This study is evidence that the experimental signal variability is due to speed of sound mismatch between blood-mimicking fluid and gel. A method of extracting embolus size from the dual frequency EBR data based on the

  15. Enhanced guided bone regeneration by asymmetrically porous PCL/pluronic F127 membrane and ultrasound stimulation.

    PubMed

    Oh, Se Heang; Kim, Tae Ho; Chun, So Young; Park, Eui Kyun; Lee, Jin Ho

    2012-01-01

    Recently, we developed a novel method for fabricating a guided bone regeneration (GBR) membrane with an asymmetrical pore structure and hydrophilicity by an immersion precipitation method. Results from an animal study, in a cranial defect model in rats, indicated that the unique asymmetrically porous GBR membrane would provide a good environment for bone regeneration. In the present study, we applied low intensity pulsed ultrasound as a simple and non-invasive stimulus to an asymmetrically porous polycaprolactone (PCL)/Pluronic F127 GBR membrane-implanted site transcutaneously in rats to investigate the feasibility of using ultrasound to stimulate enhanced bone regeneration through the membrane. It was observed that the ultrasound-stimulated PCL/F127 GBR membrane group had much faster bone regeneration behavior than a PCL/F127 membrane group w/o ultrasound or a control group (w/o membrane and ultrasound). The greater bone regeneration behavior in the GBR membrane/ultrasound group may be caused by a synergistic effect of the asymmetrically porous PCL/F127 membrane with unique properties (selective permeability, hydrophilicity and osteoconductivity), and the stimulatory effect of ultrasound (induction of angiogenesis and osteogenesis of cells).

  16. Tuning acoustic and mechanical properties of materials for ultrasound phantoms and smart substrates for cell cultures.

    PubMed

    Cafarelli, A; Verbeni, A; Poliziani, A; Dario, P; Menciassi, A; Ricotti, L

    2017-02-01

    Materials with tailored acoustic properties are of great interest for both the development of tissue-mimicking phantoms for ultrasound tests and smart scaffolds for ultrasound mediated tissue engineering and regenerative medicine. In this study, we assessed the acoustic properties (speed of sound, acoustic impedance and attenuation coefficient) of three different materials (agarose, polyacrylamide and polydimethylsiloxane) at different concentrations or cross-linking levels and doped with different concentrations of barium titanate ceramic nanoparticles. The selected materials, besides different mechanical features (stiffness from few kPa to 1.6MPa), showed a wide range of acoustic properties (speed of sound from 1022 to 1555m/s, acoustic impedance from 1.02 to 1.67MRayl and attenuation coefficient from 0.2 to 36.5dB/cm), corresponding to ranges in which natural soft tissues can fall. We demonstrated that this knowledge can be used to build tissue-mimicking phantoms for ultrasound-based medical procedures and that the mentioned measurements enable to stimulate cells with a highly controlled ultrasound dose, taking into account the attenuation due to the cell-supporting scaffold. Finally, we were able to correlate for the first time the bioeffect on human fibroblasts, triggered by piezoelectric barium titanate nanoparticles activated by low-intensity pulsed ultrasound, with a precise ultrasound dose delivered. These results may open new avenues for the development of both tissue-mimicking materials for ultrasound phantoms and smart triggerable scaffolds for tissue engineering and regenerative medicine.

  17. [Comparative evaluation of influence of low-intensity laser radiation of different spectrum components and regimen of laser work upon microcirculation in comprehensive treatment of chronic parodontitis].

    PubMed

    Krechina, E K; Shidova, A V; Maslova, V V

    2008-01-01

    Comparative study of the influence details of low-intensity pulse and continuous oscillation of laser radiation of red and infrared parts of spectrum upon microcirculation indices in comprehensive treatment of chronic parodontitis of light and middle severity was performed. For the first time the predominantly activating influence upon microcirculation in gingival tissues of the pulsed laser radiation in the red part of spectrum was established.

  18. Assessing Low-Intensity Relationships in Complex Networks

    PubMed Central

    Spitz, Andreas; Gimmler, Anna; Stoeck, Thorsten; Zweig, Katharina Anna; Horvát, Emőke-Ágnes

    2016-01-01

    Many large network data sets are noisy and contain links representing low-intensity relationships that are difficult to differentiate from random interactions. This is especially relevant for high-throughput data from systems biology, large-scale ecological data, but also for Web 2.0 data on human interactions. In these networks with missing and spurious links, it is possible to refine the data based on the principle of structural similarity, which assesses the shared neighborhood of two nodes. By using similarity measures to globally rank all possible links and choosing the top-ranked pairs, true links can be validated, missing links inferred, and spurious observations removed. While many similarity measures have been proposed to this end, there is no general consensus on which one to use. In this article, we first contribute a set of benchmarks for complex networks from three different settings (e-commerce, systems biology, and social networks) and thus enable a quantitative performance analysis of classic node similarity measures. Based on this, we then propose a new methodology for link assessment called z* that assesses the statistical significance of the number of their common neighbors by comparison with the expected value in a suitably chosen random graph model and which is a consistently top-performing algorithm for all benchmarks. In addition to a global ranking of links, we also use this method to identify the most similar neighbors of each single node in a local ranking, thereby showing the versatility of the method in two distinct scenarios and augmenting its applicability. Finally, we perform an exploratory analysis on an oceanographic plankton data set and find that the distribution of microbes follows similar biogeographic rules as those of macroorganisms, a result that rejects the global dispersal hypothesis for microbes. PMID:27096435

  19. Assessing Low-Intensity Relationships in Complex Networks.

    PubMed

    Spitz, Andreas; Gimmler, Anna; Stoeck, Thorsten; Zweig, Katharina Anna; Horvát, Emőke-Ágnes

    2016-01-01

    Many large network data sets are noisy and contain links representing low-intensity relationships that are difficult to differentiate from random interactions. This is especially relevant for high-throughput data from systems biology, large-scale ecological data, but also for Web 2.0 data on human interactions. In these networks with missing and spurious links, it is possible to refine the data based on the principle of structural similarity, which assesses the shared neighborhood of two nodes. By using similarity measures to globally rank all possible links and choosing the top-ranked pairs, true links can be validated, missing links inferred, and spurious observations removed. While many similarity measures have been proposed to this end, there is no general consensus on which one to use. In this article, we first contribute a set of benchmarks for complex networks from three different settings (e-commerce, systems biology, and social networks) and thus enable a quantitative performance analysis of classic node similarity measures. Based on this, we then propose a new methodology for link assessment called z* that assesses the statistical significance of the number of their common neighbors by comparison with the expected value in a suitably chosen random graph model and which is a consistently top-performing algorithm for all benchmarks. In addition to a global ranking of links, we also use this method to identify the most similar neighbors of each single node in a local ranking, thereby showing the versatility of the method in two distinct scenarios and augmenting its applicability. Finally, we perform an exploratory analysis on an oceanographic plankton data set and find that the distribution of microbes follows similar biogeographic rules as those of macroorganisms, a result that rejects the global dispersal hypothesis for microbes.

  20. Low-Intensity Transcranial Current Stimulation in Psychiatry.

    PubMed

    Philip, Noah S; Nelson, Brent G; Frohlich, Flavio; Lim, Kelvin O; Widge, Alik S; Carpenter, Linda L

    2017-02-24

    Neurostimulation is rapidly emerging as an important treatment modality for psychiatric disorders. One of the fastest-growing and least-regulated approaches to noninvasive therapeutic stimulation involves the application of weak electrical currents. Widespread enthusiasm for low-intensity transcranial electrical current stimulation (tCS) is reflected by the recent surge in direct-to-consumer device marketing, do-it-yourself enthusiasm, and an escalating number of clinical trials. In the wake of this rapid growth, clinicians may lack sufficient information about tCS to inform their clinical practices. Interpretation of tCS clinical trial data is aided by familiarity with basic neurophysiological principles, potential mechanisms of action of tCS, and the complicated regulatory history governing tCS devices. A growing literature includes randomized controlled trials of tCS for major depression, schizophrenia, cognitive disorders, and substance use disorders. The relative ease of use and abundant access to tCS may represent a broad-reaching and important advance for future mental health care. Evidence supports application of one type of tCS, transcranial direct current stimulation (tDCS), for major depression. However, tDCS devices do not have regulatory approval for treating medical disorders, evidence is largely inconclusive for other therapeutic areas, and their use is associated with some physical and psychiatric risks. One unexpected finding to arise from this review is that the use of cranial electrotherapy stimulation devices-the only category of tCS devices cleared for use in psychiatric disorders-is supported by low-quality evidence.

  1. The cavitation threshold of human tissue exposed to 0.2-MHz pulsed ultrasound: preliminary measurements based on a study of clinical lithotripsy.

    PubMed

    Coleman, A J; Kodama, T; Choi, M J; Adams, T; Saunders, J E

    1995-01-01

    Evidence of acoustic cavitation was identified in the form of transient echoes in ultrasound B-scan images of patients receiving extracorporeal shock-wave lithotripsy treatment on a Storz Modulith SL20. This lithotripter generates 10-microseconds duration pulses with a centre frequency of 0.2 MHz at a pulse repetition frequency of 1 Hz. The visual appearance of B-scan images was examined in a total of 30 patients and a quantitative analysis of echogenicity changes was carried out in six cases involving lithotripsy treatment of stones in the renal pelvis. In these patients new echoes were identified in images unaffected by movement artefacts and were found to occur in perinephric fat and adjacent muscle and kidney tissue at positions close to the axis of the shock-wave field between 1 and 2 cm in advance of the indicated beam focus of the lithotripter. The echogenicity within each region increased significantly above the background level when the output of the lithotripter was increased above a threshold value. The acoustic pressures corresponding to this threshold were measured in water using a calibrated PVDF membrane hydrophone. After correction for attenuation in tissue the cavitation thresholds, in terms of the temporal peak negative pressure, are found to lie between 1.5 MPa and 3.5 MPa in all six cases. Interpretation of the measured values in terms of the likely threshold at the higher frequencies used in diagnostic ultrasound is considered using a theoretical model.

  2. Development of a low intensity current monitor system

    SciTech Connect

    Gallegos, F.R.

    1991-01-01

    This report documents the development of a current transformer system used to measure pulsed ion beam currents with a wide dynamic intensity range (nA to mA, and factor of 10{sup 6}). Peak beam currents at the LAMPF accelerator typically range from 100 to nA to 40 mA with pulse widths varying from 30 to 1000 {mu}s. Signal conditioning of the peak current output provides an average current readout with a range of 1 nA to 2 mA, noise of approximately {plus minus}0.5 nA, and accuracy of {plus minus}0.1%. Since the system has proved stable and highly reliable, calibration is performed yearly. The prototype unit was built in 1985 and the final production unit was completed in early 1989. 5 refs., 14 figs.

  3. Low-Intensity Nonlinear Spectral Effects in Compton Scattering

    SciTech Connect

    Hartemann, F V; Albert, F; Siders, C W; Barty, C P

    2010-02-23

    Nonlinear effects are known to occur in Compton scattering light sources, when the laser normalized 4-potential, A = e{radical}-A{sub {mu}}A{sup {mu}}/m{sub 0}c approaches unity. In this letter, it is shown that nonlinear spectral features can appear at arbitrarily low values of A, if the fractional bandwidth of the laser pulse, {Delta}{phi}{sup -1}, is sufficiently small to satisfy A{sup 2} {Delta}{phi} {approx_equal} 1. A three dimensional analysis, based on a local plane-wave, slow-varying envelope approximation, enables the study of these effects for realistic interactions between an electron beam and a laser pulse, and their influence on high-precision Compton scattering light sources.

  4. Low intensity laser therapy accelerates muscle regeneration in aged rats

    PubMed Central

    Vatansever, Fatma; Rodrigues, Natalia C.; Assis, Livia L.; Peviani, Sabrina S.; Durigan, Joao L.; Moreira, Fernando M.A.; Hamblin, Michael R.; Parizotto, Nivaldo A.

    2013-01-01

    Background Elderly people suffer from skeletal muscle disorders that undermine their daily activity and quality of life; some of these problems can be listed as but not limited to: sarcopenia, changes in central and peripheral nervous system, blood hypoperfusion, regenerative changes contributing to atrophy, and muscle weakness. Determination, proliferation and differentiation of satellite cells in the regenerative process are regulated by specific transcription factors, known as myogenic regulatory factors (MRFs). In the elderly, the activation of MRFs is inefficient which hampers the regenerative process. Recent studies found that low intensity laser therapy (LILT) has a stimulatory effect in the muscle regeneration process. However, the effects of this therapy when associated with aging are still unknown. Objective This study aimed to evaluate the effects of LILT (λ=830 nm) on the tibialis anterior (TA) muscle of aged rats. Subjects and methods The total of 56 male Wistar rats formed two population sets: old and young, with 28 animals in each set. Each of these sets were randomly divided into four groups of young rats (3 months of age) with n=7 per group and four groups of aged rats (10 months of age) with n=7 per group. These groups were submitted to cryoinjury + laser irradiation, cryoinjury only, laser irradiation only and the control group (no cryoinjury/no laser irradiation). The laser treatment was performed for 5 consecutive days. The first laser application was done 24 h after the injury (on day 2) and on the seventh day, the TA muscle was dissected and removed under anesthesia. After this the animals were euthanized. Histological analyses with toluidine blue as well as hematoxylin-eosin staining (for counting the blood capillaries) were performed for the lesion areas. In addition, MyoD and VEGF mRNA was assessed by quantitative polymerase chain reaction. Results The results showed significant elevation (p<0.05) in MyoD and VEGF genes expression levels

  5. Generation and Quantitative Analysis of Pulsed Low Frequency Ultrasound to Determine the Sonic Sensitivity of Untreated and Treated Neoplastic Cells

    PubMed Central

    Trendowski, Matthew; Christen, Timothy D.; Zoino, Joseph N.; Acquafondata, Christopher; Fondy, Thomas P.

    2015-01-01

    Low frequency ultrasound in the 20 to 60 kHz range is a novel physical modality by which to induce selective cell lysis and death in neoplastic cells. In addition, this method can be used in combination with specialized agents known as sonosensitizers to increase the extent of preferential damage exerted by ultrasound against neoplastic cells, an approach referred to as sonodynamic therapy (SDT). The methodology for generating and applying low frequency ultrasound in a preclinical in vitro setting is presented to demonstrate that reproducible cell destruction can be attained in order to examine and compare the effects of sonication on neoplastic and normal cells. This offers a means by which to reliably sonicate neoplastic cells at a level of consistency required for preclinical therapeutic assessment. In addition, the effects of cholesterol-depleting and cytoskeletal-directed agents on potentiating ultrasonic sensitivity in neoplastic cells are discussed in order to elaborate on mechanisms of action conducive to sonochemotherapeutic approaches. PMID:26274053

  6. An ultrasound tomography system with polyvinyl alcohol (PVA) moldings for coupling: in vivo results for 3-D pulse-echo imaging of the female breast.

    PubMed

    Koch, Andreas; Stiller, Florian; Lerch, Reinhard; Ermert, Helmut

    2015-02-01

    Full-angle spatial compounding (FASC) is a concept for pulse-echo imaging using an ultrasound tomography (UST) system. With FASC, resolution is increased and speckles are suppressed by averaging pulse-echo data from 360°. In vivo investigations have already shown a great potential for 2-D FASC in the female breast as well as for finger-joint imaging. However, providing a small number of images of parallel cross-sectional planes with enhanced image quality is not sufficient for diagnosis. Therefore, volume data (3-D) is needed. For this purpose, we further developed our UST add-on system to automatically rotate a motorized array (3-D probe) around the object of investigation. Full integration of external motor and ultrasound electronics control in a custom-made program allows acquisition of 3-D pulse-echo RF datasets within 10 min. In case of breast cancer imaging, this concept also enables imaging of near-thorax tissue regions which cannot be achieved by 2-D FASC. Furthermore, moldings made of polyvinyl alcohol hydrogel (PVA-H) have been developed as a new acoustic coupling concept. It has a great potential to replace the water bath technique in UST, which is a critical concept with respect to clinical investigations. In this contribution, we present in vivo results for 3-D FASC applied to imaging a female breast which has been placed in a PVA-H molding during data acquisition. An algorithm is described to compensate time-of-flight and consider refraction at the water-PVA-H molding and molding-tissue interfaces. Therefore, the mean speed of sound (SOS) for the breast tissue is estimated with an image-based method. Our results show that the PVA-H molding concept is applicable and feasible and delivers good results. 3-D FASC is superior to 2-D FASC and provides 3-D volume data at increased image quality.

  7. Study on cavitation behavior during high-intensity focused ultrasound exposure by using optical and ultrasonic imaging

    NASA Astrophysics Data System (ADS)

    Taguchi, Kei; Takagi, Ryo; Yasuda, Jun; Yoshizawa, Shin; Umemura, Shin-ichiro

    2016-07-01

    Cavitation bubbles are known to enhance the heating effect of high-intensity focused ultrasound (HIFU). In our previous study, the use of a “triggered HIFU” sequence consisting of a high-intensity pulse and a relatively low-intensity burst was proposed as an effective method to utilize the effect of cavitation bubbles. However, the duration of each component in the sequence has not been optimized. In this study, optical imaging was carried out to observe the behavior of cavitation bubbles in a gel phantom during the triggered HIFU exposure. Ultrasound imaging using the pulse inversion method was also conducted to detect the behavior of the bubbles. The results suggest that the oscillation of cavitation bubbles become inactive as the duration of HIFU burst exposure increases to the order of 10 ms. It was also suggested that ultrasonic imaging has potential use for detecting a change in the oscillation of cavitation bubbles for optimizing a triggered HIFU sequence.

  8. Effects of acoustic streaming from moderate-intensity pulsed ultrasound for enhancing biofilm mitigation effectiveness of drug-loaded liposomes.

    PubMed

    Ma, Dong; Green, Adam M; Willsey, Graham G; Marshall, Jeffrey S; Wargo, Matthew J; Wu, Junru

    2015-08-01

    Because biofilms have resistance to antibiotics, their control using minimum amounts of chemicals and energy becomes a critical issue particularly for resource-constrained long-term space and deep-sea explorations. This preliminary study investigates how ultrasound promoting penetration of antibiotic-loaded liposomes into alginate-based bacterial biofilms, resulting in enhanced bacterial (Ralstonia insidiosa) killing. Nano-sized liposomes are used as a delivery vehicle for the antibiotic gentamicin. Alginate-based synthetic biofilms, which are widely acknowledged as biofilm phantoms, filled with liposome solution are formed at the bottoms of six-well Petri dishes and exposed to ultrasound (frequency = 2.25 MHz, 10% duty cycle, and spatially and temporally averaged intensity ISAPA = 4.4 W/cm(2)). Gentamicin is released from liposomes after they are lysed using detergent solution (0.05% sodium dodecyl sulfate, 1.0% Triton X-100) and incubated for 20 min. The alginate biofilm is dissolved and diluted, counting of colony-forming units shows about 80% of the bacteria are killed. It has also been shown the liposome-capture density by the alginate film increases linearly with the ultrasound intensity up to ISAPA = 6.2 W/cm(2) reaching approximately threefold that without ultrasound. Measurement by using particle-image velocimetry has demonstrated the acoustic streaming with modification by thermal convection controls the enhancement of the liposome capture rate.

  9. High frame rate and high line density ultrasound imaging for local pulse wave velocity estimation using motion matching: A feasibility study on vessel phantoms.

    PubMed

    Li, Fubing; He, Qiong; Huang, Chengwu; Liu, Ke; Shao, Jinhua; Luo, Jianwen

    2016-04-01

    Pulse wave imaging (PWI) is an ultrasound-based method to visualize the propagation of pulse wave and to quantitatively estimate regional pulse wave velocity (PWV) of the arteries within the imaging field of view (FOV). To guarantee the reliability of PWV measurement, high frame rate imaging is required, which can be achieved by reducing the line density of ultrasound imaging or transmitting plane wave at the expense of spatial resolution and/or signal-to-noise ratio (SNR). In this study, a composite, full-view imaging method using motion matching was proposed with both high temporal and spatial resolution. Ultrasound radiofrequency (RF) data of 4 sub-sectors, each with 34 beams, including a common beam, were acquired successively to achieve a frame rate of ∼507 Hz at an imaging depth of 35 mm. The acceleration profiles of the vessel wall estimated from the common beam were used to reconstruct the full-view (38-mm width, 128-beam) image sequence. The feasibility of mapping local PWV variation along the artery using PWI technique was preliminarily validated on both homogeneous and inhomogeneous polyvinyl alcohol (PVA) cryogel vessel phantoms. Regional PWVs for the three homogeneous phantoms measured by the proposed method were in accordance with the sparse imaging method (38-mm width, 32-beam) and plane wave imaging method. Local PWV was estimated using the above-mentioned three methods on 3 inhomogeneous phantoms, and good agreement was obtained in both the softer (1.91±0.24 m/s, 1.97±0.27 m/s and 1.78±0.28 m/s) and the stiffer region (4.17±0.46 m/s, 3.99±0.53 m/s and 4.27±0.49 m/s) of the phantoms. In addition to the improved spatial resolution, higher precision of local PWV estimation in low SNR circumstances was also obtained by the proposed method as compared with the sparse imaging method. The proposed method might be helpful in disease detections through mapping the local PWV of the vascular wall. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Design and testing of low intensity laser biostimulator

    PubMed Central

    Valchinov, Emil S; Pallikarakis, Nicolas E

    2005-01-01

    Background The non-invasive nature of laser biostimulation has made lasers an attractive alternative in Medical Acupuncture at the last 25 years. However, there is still an uncertainty as to whether they work or their effect is just placebo. Although a plethora of scientific papers published about the topic showing positive clinical results, there is still a lack of objective scientific proofs about the biostimulation effect of lasers in Medical Acupuncture. The objective of this work was to design and build a low cost portable laser device for stimulation of acupuncture points, considered here as small localized biosources (SLB), without stimulating any sensory nerves via shock or heat and to find out a suitable method for objectively evaluating its stimulating effect. The design is aimed for studying SLB potentials provoked by laser stimulus, in search for objective proofs of the biostimulation effect of lasers used in Medical Acupuncture. Methods The proposed biostimulator features two operational modes: program mode and stimulation mode and two output polarization modes: linearly and circularly polarized laser emission. In program mode, different user-defined stimulation protocols can be created and memorized. The laser output can be either continuous or pulse modulated. Each stimulation session consists of a pre-defined number of successive continuous or square pulse modulated sequences of laser emission. The variable parameters of the laser output are: average output power, pulse width, pulse period, and continuous or pulsed sequence duration and repetition period. In stimulation mode the stimulus is automatically applied according to the pre-programmed protocol. The laser source is 30 mW AlGaInP laser diode with an emission wavelength of 685 nm, driven by a highly integrated driver. The optical system designed for beam collimation and polarization change uses single collimating lens with large numerical aperture, linear polarizer and a quarter

  11. Effect of anisotropy on stress-induced electrical potentials in bovine bone using ultrasound irradiation

    NASA Astrophysics Data System (ADS)

    Matsukawa, S.; Makino, T.; Mori, S.; Koyama, D.; Takayanagi, S.; Mizuno, K.; Yanagitani, T.; Matsukawa, M.

    2017-04-01

    The bone fracture healing mechanism of the low-intensity pulsed ultrasound technique is not yet clearly understood. In our previous study, the electrical potentials induced in bone were successfully measured by focusing on piezoelectricity in the MHz range. Bone is composed of collagen and hydroxyapatite and has strong anisotropy. The purpose of this study is to investigate the effects of bone anisotropy on the electrical potentials induced by ultrasound irradiation. For this study, ultrasound bone transducers were fabricated using cortical bovine bone plates as piezoelectric devices. An ultrasound of 7.4 kPapeak-peak (i.e., the peak-to-peak pressure value) was used to irradiate the side surface of each bone plate. Electrical potentials induced in the bone plate were then measured by varying the wave propagation direction in the plate. The peak-to-peak values of these ultrasonically induced electrical potentials were found to vary with changes in the ultrasound propagation direction in the bone sample. The potential was maximized at an inclination of approximately 45° to the bone axis but was minimized around the three orthogonal directions. These maxima and minima ranged from 28 to 33 μVpeak-peak and from 5 to 12 μVpeak-peak, respectively. Additionally, our ultrasound results indicated a change in polarity due to bone anisotropy in the MHz range.

  12. Ultrasound mimics the effect of mechanical loading on bone formation in vivo on rat ulnae.

    PubMed

    Perry, Mark J; Parry, Laura K; Burton, Victoria J; Gheduzzi, Sabina; Beresford, Jon N; Humphrey, Victor F; Skerry, Tim M

    2009-01-01

    While the effect of ultrasound as an extreme example of low-magnitude high-frequency stimulation has been explored in the response of bone to injury, little is known about its effect on normal bone. This experiment was designed to test the hypothesis that ultrasound exerts a similar influence on bone as mechanical stimulation at a physiological level. Three groups of female Wistar rats were anaesthetised (6 per group). In one group, the left ulna was loaded cyclically in vivo 40 times, repeated on a further 5 occasions on alternate days. In a second group, transcutaneous low-intensity pulsed ultrasound stimulation was applied to the left ulnae for the same duration as the period of loading. In a third group, loading and ultrasound stimulation were applied concurrently. The right ulna served as non-loaded control in each animal. At the end of the experiment after 14 days, both ulnae were removed. Induced bone formation was assessed by measuring the proportion of medial periosteal bone surface with double label (dLS/BS, %) and by calculation of mineral apposition rate (MAR) from the inter-label distance. All three treatments induced a significant periosteal response, increasing dLS/BS values from <10% in control limbs to >80% in treated limbs. Increases in MAR of experimental ulnae versus contralateral control ulnae were 2.9 (+/-0.9), 8.6 (+/-2.4) and 8.7 microm (+/-3.2) for the ultrasound only, ultrasound and load, and load only groups, respectively. The effects of loading plus ultrasound were not significantly different from ultrasound alone. These data suggest that ultrasound is able to induce changes in bone that share at least some features with mechanical loading.

  13. Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high-intensity ultrasound

    PubMed Central

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Fink, Mathias; Tanter, Mickaël

    2011-01-01

    The activation of natural gas nuclei to induce larger bubbles is possible using short ultrasonic excitations of high amplitude, and is required for ultrasound cavitation therapies. However, little is known about the distribution of nuclei in tissues. Therefore, the acoustic pressure level necessary to generate bubbles in a targeted zone and their exact location are currently difficult to predict. In order to monitor the initiation of cavitation activity, a novel all-ultrasound technique sensitive to single nucleation events is presented here. It is based on combined passive detection and ultrafast active imaging over a large volume and with the same multi-element probe. Bubble nucleation was induced with a focused transducer (660kHz, f#=1) driven by a high power (up to 300 W) electric burst of one to two cycles. Detection was performed with a linear array (4–7MHz) aligned with the single-element focal point. In vitro experiments in gelatin gel and muscular tissue are presented. The synchronized passive detection enabled radio-frequency data to be recorded, comprising high-frequency coherent wave fronts as signatures of the acoustic emissions linked to the activation of the nuclei. Active change detection images were obtained by subtracting echoes collected in the unucleated medium. These indicated the appearance of stable cavitating regions. Thanks to the ultrafast frame rate, active detection occurred as soon as 330 μs after the high amplitude excitation and the dynamics of the induced regions were studied individually. PMID:21429844

  14. Combined passive detection and ultrafast active imaging of cavitation events induced by short pulses of high-intensity ultrasound.

    PubMed

    Gateau, Jérôme; Aubry, Jean-François; Pernot, Mathieu; Fink, Mathias; Tanter, Mickaël

    2011-03-01

    The activation of natural gas nuclei to induce larger bubbles is possible using short ultrasonic excitations of high amplitude, and is required for ultrasound cavitation therapies. However, little is known about the distribution of nuclei in tissues. Therefore, the acoustic pressure level necessary to generate bubbles in a targeted zone and their exact location are currently difficult to predict. To monitor the initiation of cavitation activity, a novel all-ultrasound technique sensitive to single nucleation events is presented here. It is based on combined passive detection and ultrafast active imaging over a large volume using the same multi-element probe. Bubble nucleation was induced using a focused transducer (660 kHz, f-number = 1) driven by a high-power electric burst (up to 300 W) of one to two cycles. Detection was performed with a linear array (4 to 7 MHz) aligned with the single-element focal point. In vitro experiments in gelatin gel and muscular tissue are presented. The synchronized passive detection enabled radio-frequency data to be recorded, comprising high-frequency coherent wave fronts as signatures of the acoustic emissions linked to the activation of the nuclei. Active change detection images were obtained by subtracting echoes collected in the unnucleated medium. These indicated the appearance of stable cavitating regions. Because of the ultrafast frame rate, active detection occurred as quickly as 330 μs after the high-amplitude excitation and the dynamics of the induced regions were studied individually.

  15. Reflecting on Mirror Mechanisms: Motor Resonance Effects during Action Observation Only Present with Low-Intensity Transcranial Magnetic Stimulation

    PubMed Central

    Loporto, Michela; Holmes, Paul S.; Wright, David J.; McAllister, Craig J.

    2013-01-01

    Transcranial magnetic stimulation (TMS) studies indicate that the observation of other people's actions influences the excitability of the observer's motor system. Motor evoked potential (MEP) amplitudes typically increase in muscles which would be active during the execution of the observed action. This ‘motor resonance’ effect is thought to result from activity in mirror neuron regions, which enhance the excitability of the primary motor cortex (M1) via cortico-cortical pathways. The importance of TMS intensity has not yet been recognised in this area of research. Low-intensity TMS predominately activates corticospinal neurons indirectly, whereas high-intensity TMS can directly activate corticospinal axons. This indicates that motor resonance effects should be more prominent when using low-intensity TMS. A related issue is that TMS is typically applied over a single optimal scalp position (OSP) to simultaneously elicit MEPs from several muscles. Whether this confounds results, due to differences in the manner that TMS activates spatially separate cortical representations, has not yet been explored. In the current study, MEP amplitudes, resulting from single-pulse TMS applied over M1, were recorded from the first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles during the observation of simple finger abductions. We tested if the TMS intensity (110% vs. 130% resting motor threshold) or stimulating position (FDI-OSP vs. ADM-OSP) influenced the magnitude of the motor resonance effects. Results showed that the MEP facilitation recorded in the FDI muscle during the observation of index-finger abductions was only detected using low-intensity TMS. In contrast, changes in the OSP had a negligible effect on the presence of motor resonance effects in either the FDI or ADM muscles. These findings support the hypothesis that MN activity enhances M1 excitability via cortico-cortical pathways and highlight a methodological framework by which the neural

  16. [Adaptation reactions of rat blood exposed to low intensity electromagnetic radiation].

    PubMed

    Krylov, V N; Deriugina, A V

    2010-06-01

    It is carried out research of action low-intensive electromagnetic radiations--low-intensive laser radiation and radiations of the highest frequency on normal animals and at modelling the stress-reaction, caused by introduction of adrenaline. Absence of effects of system of blood is noted at action low-intensive electromagnetic radiations on normal an organism and them correction action on alteration an organism, shown in restoration of the broken parameters--leukocyte the blood count, electrophoretic mobility of erythrocytes and phospholipide's structure of their membranes.

  17. Can ultrasound propagate in the joint space of a human knee?

    PubMed

    White, D; Evans, J A; Truscott, J G; Chivers, R A

    2007-07-01

    A large body of evidence supports the principle that the use of low-intensity pulsed ultrasound with a frequency of 1.5 MHz can reduce fracture healing time. It is hypothesized that similar therapeutic benefits may be achieved in damaged articular cartilage. This study looks specifically at a 22-mm circular ultrasound transducer delivering ultrasound with a frequency of 1.5 MHz. A human cadaver knee was imaged using CT, the resulting images were used to help map a number of hydrophone positions in the joint from which measurements were taken. The experimental results suggest that at best there is a 30-mm window in which to place the ultrasound transducer for ultrasound to propagate through the joint space. In terms of a clinical device delivering an I(SATA) of 30 mW cm(-2) to anterior regions of the joint, the I(SATA) in posterior regions will at best be in the region of 10 mW cm(-2). The clinical implications of this are not known and require further investigation.

  18. AXAF low intensity-low temperature (LILT) testing of the development verification test (DVT) solar panel

    SciTech Connect

    Alexander, D.; Edge, T.; Willowby, D.

    1998-07-01

    The planned orbit of the Advanced X-ray Astrophysics Facility (AXAF) spacecraft will subject the spacecraft to both short (less than 30 minutes for solar and less than 2 hours for lunar) and long earth eclipses and lunar eclipses with combined conjunctive duration of up to 3 to 4 hours. Lack of proper Electrical Power System (EPS) conditioning prior to eclipse may cause loss of mission. To avoid this problem, for short eclipses, it is necessary to off-point the solar array prior to or at the beginning of the eclipse to reduce the battery state of charge. This yields less overcharge during the high charge currents at sun entry. For long lunar eclipses, solar array pointing and load scheduling must be tailored for the profile of the eclipse. The battery state of charge, loads, and solar array current-voltage (I-V) characteristic curves must be known or predictable to maintain the bus voltage within acceptable range. To address engineering concerns about the electrical performance of the AXAF solar array under penumbral Low Intensity and Low Temperature (LILT) conditions, Marshall Space Flight Center (MSFC) engineers undertook special testing of the AXAF Development Verification Test (DVT) solar panel in September-November 1997. In the test the DVT test panel was installed in a thermal vacuum chamber with a large view window with a mechanical flapper door. The DVT test panel was flash tested with a Large Area Pulsed Solar Simulator (LAPSS) at various fractional sun intensities and panel (solar cell) temperatures. The testing was unique with regards to the large size of the test article and type of testing performed. The test setup and results will be presented.

  19. Ultrasound-guided femoral arterial access in pediatric cardiac catheterizations: A prospective evaluation of the prevalence, risk factors, and mechanism for acute loss of arterial pulse.

    PubMed

    Alexander, John; Yohannan, Thomas; Abutineh, Iman; Agrawal, Vijaykumar; Lloyd, Hannah; Zurakowski, David; Waller, B Rush; Sathanandam, Shyam

    2016-12-01

    The objectives of this study were to describe the prevalence, mechanisms, and identify risk factors for acute loss of arterial pulse (LOP) in children who had ultrasound-guided femoral arterial access (UGFAA) during cardiac catheterization. LOP is a known complication in children following femoral arterial (FA) access for cardiac catheterization. The prevalence of LOP requiring treatment ranges between 4% and 8%. A prospective study was performed including 486 cardiac catheterizations using UGFAA in children ≤18 years over a 3 years period. Ultrasound and Doppler evaluations were performed prior to and at the end of the procedure. LOP was identified in 33 cases (6.8%) with 23 (4.7%) requiring treatment. For children ≤6 months, the prevalence of LOP requiring treatment was 13.6%. FA diameter <3 mm was the only significant independent predictor for LOP (OR: 8.44, 95% CI: 2.07-34.5, P < 0.001). Smaller patient size, number of access attempts, time required for access, operator experience, sheath size, and length of procedure were not found to be significant predictors. Children with LOP had a greater percentage decrease in vessel diameter (median 62% vs 18%, P < 0.001) compared to those without LOP. FA thrombus was diagnosed only in 9 patients (27% of those with LOP). The prevalence of LOP requiring treatment is 4.7% when UGFAA is used during pediatric cardiac catheterizations. Arterial spasm was more common than thrombus as a cause of LOP. FA diameter <3 mm was the only independent predictor for LOP in this carefully designed prospective study. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  20. Transcranial measurement of blood velocities in the basal cerebral arteries using pulsed Doppler ultrasound: a method of assessing the Circle of Willis.

    PubMed

    Padayachee, T S; Kirkham, F J; Lewis, R R; Gillard, J; Hutchinson, M C; Gosling, R G

    1986-01-01

    Transcranial pulsed Doppler ultrasound and spectral analysis were used for detection of blood velocities in the basal cerebral arteries. The Doppler transducer was placed superior to the zygomatic arch and during insonation of the middle cerebral artery care was taken to obtain maximum Doppler-shift frequency signals since this allowed a small angle between the ultrasound beam and this artery. Doppler signals were obtained from the middle, anterior, and posterior cerebral arteries in 20 volunteers with the average depth of the Doppler gate at 4.9 (4.6-5.2 cm), 5.2 (4.9-5.4 cm), and 6.3 cm (6.0-6.9 cm), respectively. These measurements were in agreement with those obtained for 15 cadaver studies, in whom the distance from the proposed site of the Doppler transducer to each basal cerebral artery was measured as 4.7 +/- 0.6, 5.3 +/- 0.5, and 5.9 +/- 0.9 cm, respectively. The reproducibility of middle cerebral artery blood velocity values was tested in seven subjects and showed a variation of not more than 8% in any individual. The method was used in combination with common carotid compression to assess four patients who had occlusive extracranial carotid disease; in three the disease was more severe on one side and reversal of blood flow in the proximal ipsilateral anterior cerebral artery was demonstrated, consistent with cross flow from the contralateral side via the anterior communicating artery of the Circle of Willis. In the fourth patient augmentation of posterior cerebral artery blood velocities during common carotid compression indicated the major collateral source was from the vertebrobasilar system.

  1. Spectroscopy of spontaneous Raman scattering of a liquid-water local structure in the field of an intense ultrasound pulse

    NASA Astrophysics Data System (ADS)

    Brysev, A. P.; Bunkin, A. F.; Klopotov, R. V.; Krutyanskii, L. M.; Nurmatov, A. A.; Pershin, S. M.

    2002-08-01