Numerical simulation is one of the most significant methods to predict the temperature distribution in high-intensity focused ultrasound (HIFU) therapy. In this study, the adopted numerical simulation was used based on a transcranial ultrasound therapy model taking a human skull as a reference. The approximation of the Westervelt formula and the Pennes bio-heat conduction equation were applied to the simulation of the transcranial temperature distribution. According to the temperature distribution and the Time Reversal theory, the position of the treatable focal region was corrected and the hot spot existing in the skull was eliminated. Furthermore, the influence of the exposure time, input power and the distance between transducer and skull on the temperature distribution was analyzed. The results showed that the position of the focal region could be corrected and the hot spot was eliminated using the Time Reversal theory without affecting the focus. The focal region above 60℃ could be formed at the superficial tissue located from the skull of 20 mm using the hot spot elimination method and the volume of the focal region increases with the exposure time and the input power in a nonlinear form. When the same volume of the focal region was obtained, the more power was inputted, the less the exposure time was needed. Moreover, the volume of the focal region was influenced by the distance between the transducer and the skull.
The AC impedance of human hepatoma SMMC-7721 cells were measured in our laboratory by Agilent 4294A impedance analyzer in the frequency range of 0.01-100 MHz. And then the effect of hematocrit on electrical impedance characteristics of hepatoma cells was observed by electrical impedance spectroscopy, Bode diagram, Nyquist diagram and Nichols diagram. The results showed that firstly, there is a frequency dependence, i.e., the increment of real part and the imaginary part of complex electrical impedance (ΔZ', ΔZ″), the increment of the amplitude modulus of complex electrical impedance (Δ|Z*|) and phase angle (Δθ) were all changed with the increasing frequency. Secondly, it showed cell volume fraction (CVF) dependence, i.e., the increment of low-frequency limit (ΔZ'0, Δ|Z*|0), peak (ΔZ″p, Δθp), area and radius (Nyquist diagram, Nichols diagram) were all increased along with the electric field frequency. Thirdly, there was the presence of two characteristic frequencies: the first characteristic frequency (fC1) and the second characteristic frequency (fC2), which were originated respectively in the polarization effects of two interfaces that the cell membrane and extracellular fluid, cell membrane and cytoplasm. A conclusion can be drawn that the electrical impedance spectroscopy is able to be used to observe the electrical characteristics of human hepatoma cells, and therefore this method can be used to investigate the electrophysiological mechanisms of liver cancer cells, and provide research tools and observation parameters, and it also has important theoretical value and potential applications for screening anticancer drugs.
ObjectiveTo investigate the effectiveness of ileal mucosal seromuscular patch for bladder expansion combined with rehabilitation training for treating neurogenic bladder dysfunction (NBD) with hyperreflexia. MethodsA retrospective study was performed on the clinical data of 61 patients with NBD and hyperreflexia who were treated and followed up between July 2008 and June 2013. There were 36 males and 25 females, aged 6-23 years (mean, 10 years). The reasons included meningomyelocele operation (43 patients), surgery for lipoma in lumbar vertebra (4 patients), operation of thoracolubar teratoma (2 patients), and lumbosacral spina bifida (12 patients). The results of urodynamics indicated that bladder volume decreased obviously and the residual urine increased. The voiding cystourethrography (VCUG) showed the vesicoureteral reflux (VUR), including 6 cases (10 sides) of grade V, 7 cases (12 sides) of grade IV, and 6 cases (8 sides) of grade III. The color doppler ultrosound showed mild hydronephrosis in 23 cases (41 sides), moderate hydronephrosis in 25 cases (42 sides), and severe hydronephrosis in 13 cases (22 sides). The blood biochemical examination suggested chronic renal failure (CRF) in 13 cases. The treatment included augmentation for bladder and rehabilitation training after operation. ResultsThe operation time was (157±26) minutes; the intraoperative blood loss was (43±15) mL, and no patient was given blood transfusion. The patients were followed up 1.5-6.0 years (mean, 4.5 years). Vesical fistula occurred in 4 cases, urinary infection in 5 cases, dysuresia in 2 cases, and cystolith in 1 case after operation. At 1 year after operation, the International Consultation on Incontinence Questionnaire-Urinary Incontience Short Form (CIQ-SF) score was significantly better than preoperative score (H=89.813, P=0.000). The urodynamic data showed that the difference value between observed and theoretical bladder volumes, bladder compliance, residual urine volume, maximum flow rate, and maximum storage detrusor pressure were significantly better than preoperative ones (P<0.05). And the color doppler ultrasound showed mild hydronephrosis in 34 cases (56 sides), moderate hydronephrosis in 18 cases (33 sides), and severe hydronephrosis in 9 cases (16 sides). VCUG showed that bladder volume obviously increased, no contracture was observed; and VUR was improved. And renal function was improved in 13 patients with CRF. ConclusionIleal mucosal seromuscular patch for bladder expansion combined with postoperative rehabilitation training has good effectiveness in treating NBD with hyperreflexia.
ObjectiveTo systematically review the efficacy and safety of dust mite sublingual immunotherapy (SLIT) in the treatment of children with allergic rhinitis. MethodsRandomized controlled trials (RCTs) about SLIT treating allergic rhinitis in pediatric patients was searched in PubMed, EMbase, CBM, Ovid, The Cochrane Library (Issue 5, 2014), CNKI, VIP and WanFang Data from inception to May 2014. Two reviewers independently screened literature according to inclusion and exclusion criteria, extracted data, and assessed methodological quality of included studies. Then meta-analysis was conducted using RevMan 5.3 software. ResultsA total of nine RCTs including 663 patients were finally included. The results of meta-analysis indicated that:the trial group was superior to the control group in reducing the scores of drug use (SMD=-0.61, 95%CI-0.94 to-0.27, P=0.000 4) and mite-specific serum IgE levels (follow-up time > 22 weeks:SMD=0.71, 95%CI 0.31 to 1.12, P=0.000 5). However, no significant difference was found between the two groups in the scores of nasal symptoms (SMD=0.06, 95%CI-0.13 to 0.25, P=0.55) and the incidence of adverse reaction (OR=1.3, 95%CI 0.89 to 1.90, P=0.17). ConclusionSLIT could decrease the use frequency of antihistamine, β-agonist and nasal spray steroids, and it has less adverse reaction and better safety in the treatment of children with allergic rhinitis. But SLIT could neither effectively alleviate nasal symptoms nor reduce mite-specific serum IgE levels of pediatric patients with allergic rhinitis in a short time.