Evaluation of inertial cavitation is a significant problem where this mechanism of action is responsible for therapeutic applications such as drug delivery. It has shown that using multiple frequencies one is able to enhance and control induced cavitation. In this study, we used different sonication frequencies as 28 kHz, 130 kHz, 1 MHz, 3 MHz and their dual combinations to enhance acoustic cavitation. At each frequency, two different intensities were used and the subharmonic amplitude of each frequency in combinations was measured. It was observed that in combinations which include 28 kHz, the cavitation activity is enhanced. The 28 kHz subharmonic amplitude was used to compare these protocols in their ability to enhance cavitation. Besides, the area of cavitation damage was determined using an aluminum foil. Our results showed that the inertial cavitation activity increased at higher intensities and there is a significant correlation between the subharmonic amplitude and sonication intensity at each frequency (R>0.90). In addition, simultaneous combined dual-frequency orthogonal sonication at 28 kHz with other frequencies used can significantly increase the inertial cavitation activity as compared to the algebraic sum of the individual ultrasound irradiations in 28 kHz subharmonic frequency. The 28 kHz subharmonic amplitude for 28 kHz (0.04 W/cm(2)) and 3 MHz (2 and 1 W/cm(2)) combined dual frequency were about 4.6 and 1.5 times higher than that obtained from the algebraic sum of 28 kHz and 3 MHz irradiation, respectively. Also the 28 kHz subharmonic amplitude for combination of 28 kHz (0.04 W/cm(2)) and 1 MHz (2 and 1 W/cm(2)) were about 2.4 and 1.6 times higher than that obtained with their algebraic sum. Among different combinations, the continuous mode for two ultrasound sources of 28 kHz (0.04 W/cm(2)) and 3 MHz (2 W/cm(2)) is more effective than other combinations (p-value<0.05). The results of effective irradiation area showed no damaged aluminum foil in MHz sonication alone. However, there is significant difference between the effective irradiation area of combined dual frequency 28 kHz and 3 MHz with other irradiation modes (p-value<0.05) and it is limited locally.
To overcome the side effects caused by systemic administration of doxorubicin, nanosized polymeric micelles were used in combination with dual frequency ultrasonic irradiation. These micelles release the drug due to acoustic cavitation, which is enhanced in dual frequency ultrasonic fields. To form the drug-loaded micelles, Pluronic P-105 copolymer was used, and doxorubicin was physically loaded into stabilized micelles with an average size of 14 nm. In this study, adult female Balb/C mice were transplanted with spontaneous breast adenocarcinoma tumors and were injected with a dose of 1.3 mg/kg doxorubicin in one of three forms: free doxorubicin, micellar doxorubicin without sonication and micellar doxorubicin with sonication. To increase cavitation yield, the tumor region was sonicated for 2.5 min at simultaneous frequencies of 3 MHz (I(SATA)=2 W/cm(2)) and 28 kHz (I(SATA)=0.04 W/cm(2)). The animals were sacrificed 24h after injection, and their tumor, heart, spleen, liver, kidneys and plasma were separated and homogenized. The drug content in the tissues was determined using tissue fluorimetry (350 nm excitation and 560 nm emission), and standard drug dose curves were obtained for each tissue. The results show that in the group that received micellar doxorubicin with sonication, the drug concentration in the tumor tissue was significantly higher than in the free doxorubicin injection group (8.69 times) and the micellar doxorubicin without sonication group (2.60 times). The drug concentration in other tissues was significantly lower in the micellar doxorubicin with sonication group relative to the free doxorubicin (3.35 times) and the micellar drug without sonication (2.48 times) groups (p<0.05). We conclude that dual frequency sonication improves drug release from micelles and increases the drug uptake by tumors due to sonoporation. The proposed drug delivery system creates an improved treatment capability while reducing systemic side effects caused by drug uptake in other tissues.
SummaryBackground:The aim of this study was to determine age, gender, and hemispheric differences in the volume of the human neostriatum (striatum) nucleus in healthy humans.Material/Methods:This study was performed on 120 normal human subjects (60 males, 60 females, right-handed) 15–65 years old, divided into two groups: young (<40 yrs) and old (=≥40 yrs). Sectional brain images were obtained via magnetic resonance imaging (MRI), analyzed and processed using the Image-J software, and the striatum volume was calculated using the Cavalieri’s principle, retrospectively.Results:The analyses revealed bilateral age-related shrinkage of the putamen in both genders and the putamen and caudate nucleus were significantly smaller in older than in younger subjects (P-value <0.001). The age-related shrinkage of the caudate and putamen nucleus in men and women was about 5%, 5% and 4%, 4%, respectively, and there were statistically significant volume differences between males and females (P-value <0.05). In both genders, a significant rightward asymmetry was observed in the caudate and putamen nucleus (3.89%, 4.21% in men and 4.51%, 3.32% in women).Conclusions:Bilateral age-related shrinkage and rightward asymmetry of the striate nucleus was found in healthy adults and there were significant volume differences between men and women. Obtained results provide useful baseline data on age and gender-related changes of the volume of the striatum.
Educational and practice age, sex, type of hospital, and geographical region affect he KAP of interventional radiology staff regarding RP. Since many of the subjective radiation harms for both medical team and patients, this can be easily controlled and prevented; a checkup for personnel of interventional radiology departments, considering samples from different parts of the country with different levels of education, continuous training, and practical courses may help map the status of KAP. The results of this study may also help authorized health physics officers design strategic plans to enhance the quality of such services in radiation departments.
Stereotactic radiosurgery was originally introduced by Lars Leksell in 1951. This treatment refers to the noninvasive destruction of an intracranial target localized stereotactically. The purpose of this study was to identify the dose delivered to the parotid, ovaries, testis and thyroid glands during the Gamma Knife radiosurgery procedure. A three-dimensional, anthropomorphic phantom was developed using natural human bone, paraffin and sodium chloride as the equivalent tissue. The phantom consisted of a thorax, head and neck and hip. In the natural places of the thyroid, parotid (bilateral sides) and ovaries (midline), some cavities were made to place TLDs. Three TLDs were inserted in a batch with 1 cm space between the TLDs and each batch was inserted into a single cavity. The final depth of TLDs was 3 cm from the surface for parotid and thyroid and was 15 cm for the ovaries. Similar batches were placed superficially on the phantom. The phantom was gamma irradiated using a Leksell model C Gamma Knife unit. Subsequently, the same batches were placed superficially over the thyroid, parotid, testis and ovaries in 30 patients (15 men and 15 women) who were undergoing radiosurgery treatment for brain tumours. The mean dosage for treating these patients was 14.48 +/- 3.06 Gy (10.5-24 Gy) to a mean tumour volume of 12.30 +/- 9.66 cc (0.27-42.4 cc) in the 50% isodose curve. There was no significant difference between the superficial and deep batches in the phantom studies (P-value < 0.05). The mean delivered doses to the parotid, thyroid, ovaries and testis in human subjects were 21.6 +/- 15.1 cGy, 9.15 +/- 3.89 cGy, 0.47 +/- 0.3 cGy and 0.53 +/- 0.31 cGy, respectively. The data can be used in making decisions for special clinical situations such as treating pregnant patients or young patients with benign lesions who need radiosurgery for eradication of brain tumours.
IntroductionThe effects of electromagnetic fields on biological organisms have been a controversial and also interesting debate over the past few decades, because modern civilization is overwhelmed by a broad range of electromagnetic fields, including extremely low frequency electromagnetic fields (ELF/EMF). Numerous investigations, from monitoring changes at molecular levels to the behavioral aspects, have been carried out in vitro and in vivo in order to illustrate different effects of ELF/EMF e.g., its impacts on cells, 1 hormones, 2-6 neurophysiological properties and sleep, 7,8 biochemical factors and metabolism, 9-11 pathology, 12,13 DNA damages and chromosome abnormalities, [14][15][16][17][18][19] reproduction and development, 20 and cancer. [21][22][23] On the other hand, the fact that central nervous system (CNS) as a very complicated electrochemical system may be influenced by electromagnetic fields attracts many researches interests. Vázquez-García et al reported that exposure to 60 Hz ELF/EMF can improves social recognition in male rats. The effects of electromagnetic fields on biological organisms have been a controversial and also interesting debate over the past few decades, despite the wide range of investigations, many aspects of extremely low frequency electromagnetic fields (ELF/EMFs) effects including mechanism of their interaction with live organisms and also their possible biological applications still remain ambiguous. In the present study, we investigated whether the exposures of ELF/EMF with frequencies of 3 Hz and 60 Hz can affect the memory, anxiety like behaviors, electrophysiological properties and brain's proteome in rats. Methods: Male rats were exposed to 3 Hz and 60 Hz ELF/EMFs in a protocol consisting of 2 cycles of 2 h/day exposure for 4 days separated with a 2-day interval. Short term memory and anxiety like behaviors were assessed immediately, 1 and 2 weeks after the exposures. Effects of short term exposure were also assessed using electrophysiological approach immediately after 2 hours exposure. Results: Behavioral test revealed that immediately after the end of exposures, locomotor activity of both 3 Hz and 60 Hz exposed groups significantly decreased compared to sham group. This exposure protocol had no effect on anxiety like behavior during the 2 weeks after the treatment and also on short term memory. A significant reduction in firing rate of locus coeruleus (LC) was found after 2 hours of both 3 Hz and 60 Hz exposures. Proteome analysis also revealed global changes in whole brain proteome after treatment. Conclusion: Here, some evidence regarding the fact that such exposures can alter locomotor activity and neurons firing rate in male rats were presented.
Various forms of TiO nanoparticles reduced cell proliferation and induced apoptosis in cancer cells. Some forms of TiO nanoparticles such as brookite BSA also inhibited cell invasion. PEG-amorph TiO nanoparticles increased cell invasion. These differences seem to be due to the effects of different configurations of TiO nanoparticles. TiO may provide a new strategy for cancer treatment and more studies are needed.
Introduction: During the last 3 decades, human is exposed to extremely low frequency electromagnetic fields (ELF-EMF) emitted by power lines and electronic devices. It is now well accepted that ELF-EMF are able to produce a variety of biological effects, although the molecular mechanism is unclear and controversial. Investigation of different intensities effects of 50 Hz ELF-EMF on cell morphology and protein expression is the aim of this study. Methods: SH-SY5Y human neuroblastoma cell line was exposed to 0.5 and 1 mT 50 Hz (ELF-EMF) for 3 hours. Proteomics techniques were used to determine the effects of these fields on protein expression. Bioinformatic and statistical analysis of proteomes were performed using Progensis SameSpots software. Results: Our results showed that exposure to ELF-EMF changes cell morphology and induces a dose-dependent decrease in the proliferation rate of the cells. The proteomic studies and bioinformatic analysis indicate that exposure to 50 Hz ELF-EMF leads to alteration of cell protein expression in both dose-dependent and intensity dependent manner, but the later is more pronounced. Conclusion: Our data suggests that increased intensity of ELF-EMF may be associated with more alteration in cell protein expression, as well as effect on cell morphology and proliferation.
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