How to enhance non-thermal effects of ultrasoundDecember 29, 2008In recent years HIFU has been widely used for the treatment of solid tumors, such as liver tumor, bone tumor, and breast cancer. The mechanism for therapeutic actions of HIFU includes thermal effects and non-thermal effects with the latter dominated by cavitational effects. Adjusting acoustic parameters of pulsed high intensity focused ultrasound (PHIFU) can control thermal effects and non-thermal effects; short duty cycle and high intensity favors the occurrence of cavitation. Ultrasound contrast agent (UCA) can enhance cavitational effects. Lesions caused by non-thermal effects have characteristic pathological changes quite different from those of thermal lesions. A research article to be published on November 21, 2008 in the World Journal of Gastroenterology addresses this question. The research group led by Professor Zhi-Biao Wang from Department of Biomedical Engineering of Chongqing Medical University used PHIFU with short duty cycle and high intensity combined with UCA to damage rabbit liver VX2 tumour by non-thermal effect, and the non-thermal damage was evaluated by histopathology. Liver VX2 tumor model were established in 20 rabbits, which were then divided randomly into PHIFU combined with UCA group (PHIFU+UCA group) and sham group, with 10 rabbits in each group. In the PHIFU+UCA group, 0.2 mL of SonoVue was injected intravenously, followed by rapid injection of 1 mL normal saline. Fifteen seconds after the injection, the tumours were exposed to HIFU with ISP 5900W/cm2 for 90 seconds. Rabbits were sacrificed one day after HIFU exposure. Specimens of the exposed tumor tissues were obtained and observed pathologically under light microscope and transmission electron microscope. The remaining exposed tumor tissues were sent for TTC staining. Before TTC staining, tumor tissues in both the sham and the PHIFU+UCA group resembled gray fish meat; after TTC staining, the tumour tissues were uniformly stained red, with a clear boundary between tumor tissue and normal tissue. For PHIFU + UCA group, light microscopy displayed abundant vacuoles of various sizes in the cytoplasm and in some cells, chromatin margination and karyopyknosis were present. Electron microscopic examination revealed presence of karyopyknosis and chromatin margination in some cells, intercellular space widening, the presence of high electron-density apoptotic bodies and many vacuoles of various sizes in the cytoplasm.
This study found that PHIFU combination with UCA can enhance non-thermal effects of ultrasound, and the pathological characteristics of the non-thermal damage is different from those of thermal damage. Immunohistochemical detection found that PHIFU combined with UCA can promote tumor cell apoptosis and inhibit tumor cell proliferation, which will be reported in another article. World Journal of Gastroenterology Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Junk DNA Carbon Emissions Gamma-ray Burst Volcano X-ray Sarcoma Diamond Brachytherapy Head And Neck Cancer Yeast Cells Meditation Solar Cells Drug Resistance Alcohol Dependence Cloning Pathogen Infectious Disease Caffeine Biology Type 2 Diabetes Antipsychotic Hiv-infected Caloric Restriction Nuclear Power Hot Flashes
See More: Science News Tags | |||||||||||||||||||||
|
Related Ultrasound Current Events and Ultrasound News Articles The sound of light: Innovative technology shatters the barriers of modern light microscopy Researchers at the Helmholtz Zentrum München and the Technische Universität München are using a combination of light and ultrasound to visualize fluorescent proteins that are seated several centimeters deep into living tissue. Infants should be screened for hip trouble Developmental hip dysplasia is the most common congenital defect in newborns. The condition occurs when a hip joint is shallow, unstable or when the joint is dislocated. Infants with the condition are often at risk of developing arthritis of the hip as a young adult. Early heart attack therapy with bone marrow extract improves cardiac function A UCSF study for the treatment of heart failure after heart attack found that the extract derived from bone marrow cells is as effective as therapy using bone marrow stem cells for improving cardiac function, decreasing the formation of scar tissue and improving cardiac pumping capacity after heart attack. Rotator cuff treatment provides immediate tendonitis relief A minimally invasive procedure to treat tendonitis in the rotator cuff of the shoulder provides immediate symptom relief to the patient. What should a teenage girl do if she finds a lump in her breast? If a lump is found in the breast of an adolescent girl, she often will undergo an excisional biopsy. First acoustic metamaterial 'superlens' created by U. of I. researchers A team of researchers at the University of Illinois has created the world's first acoustic "superlens," an innovation that could have practical implications for high-resolution ultrasound imaging, non-destructive structural testing of buildings and bridges, and novel underwater stealth technology. Meckel's diverticulum masked by intermittent recurrent subocclusive episodes Meckel's diverticulum (MD) is the most frequent congenital abnormality of the small bowel and it is often difficult to diagnose. Successful neurosurgery with transcranial MR-guided high-intensity focused ultrasound The Magnetic Resonance Center of the University Children's Hospital Zurich has achieved a world first break through in MR-guided, non-invasive neurosurgery. A urine test for appendicitis? Appendicitis is the most common childhood surgical emergency, but the diagnosis can be challenging, especially in children, often leading to either unnecessary surgery in children without appendicitis, or a ruptured appendix and serious complications when the condition is missed. Autonomous robot detects shrapnel Bioengineers at Duke University have developed a laboratory robot that can successfully locate tiny pieces of metal within flesh and guide a needle to its exact location -- all without the need for human assistance. More Ultrasound Current Events and Ultrasound News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||