Many diseases that affect the central nervous system are intractable to conventional therapies and therefore require alternative treatments such as gene therapy. Such therapy requires absolute safety since the central nervous system is critical to survival. Choice of non-viral vectors such as naked plasmid DNA may have some merits. However, the transduction efficiencies of these vectors are extremely low. We have investigated the use of ultrasound to enhance the efficiency of naked plasmid DNA transfer. Using ultrasound, we targeted the central nervous system and found that insonation at 5.0W/cm2 for 5 seconds effectively transduced plasmid DNA into cultured slices of mouse brain. Since ultrasound successfully transduced naked plasmid DNA into neural tissue, our approach may hold significant promise for gene transfer to the central nervous system.
Purpose: The thrombus dissolution efficiency of tPA is enhanced by ultrasonic irradiation. Furthermore, a free radical scavenger “Edaravone”is used frequently in Japan. Considering the clinical situation, the safety of applying ultrasonic irradiation at the time of Edaravone medication was evaluated. Methods: Organ-cultured slices of mouse brain and human neuroblastoma SK-N-MC cells were used. Four groups were set up: a control group, an Edaravone medication group, an ultrasonic irradiation group, and a group in which both methods were combined. Six replicates were used for evaluation with mouse brain slices and 2 for evaluation with SK-N-MC cells. Ultrasonic irradiation was applied at 500kHz and 0.3W/cm2 with a continuous sine wave, with intermittent application. Edaravone was used at 6μM. Cell death in the mouse brain slices was evaluated by PI staining over 28days. The number of apoptotic SK-N-MC cells was evaluated by the TUNEL and FACS methods. Results: There was no increase of dead cells in the mouse brain slices, or of apoptotic SK-N-MC cells, in any of the groups. Conclusion: Our findings suggest that ultrasound and Edaravone do not injure cells in the central nervous system.
Although elastic stockings are used to reduce the risk of deep vein thrombosis (DVT) after stroke, their efficacy has not been evaluated. We evaluated the effect of elastic stockings in preventing DVT after stroke using ultrasonography. Methods: Among 101 patients with severe hemiplegia after stroke who were enrolled, 30 were given no prophylaxis (controls) and 71 were prescribed elastic stockings. We evaluated DVT in the paralytic lower extremities using ultrasonography for more than seven days after stroke onset. Ultrasonographically, DVT was visualized as an intraluminal thrombus, lack of venous compressibility and lack of signal on colour flow images. Results: In the control group, 9 patients (30%) had DVT and 6 (20%) had moyamoya echo an average of 19. 1days after onset. In the prophylaxis group, 4 patients (5.6%) had DVT and 16 (22.5%) had moyamoya echo an average of 14.4 days after onset. There was a significant reduction in the incidence of DVT in the patients who used elastic stockings (odds ratio 0.139,95% CI 0.039-0.499). Conclusion: Elastic stockings are useful for preventing DVT in patients after stroke.
Background: There have been two major problems in surgery for aneurysm via the interhemispheric approach. One is injury to bridging veins, which can cause serious venous infarction, and the other is disorientation when searching for the aneurysm using a microscope. We investigated the possibility of resolving these problems with ultrasonographic assistance during surgery. Method: Eleven patients with cerebral aneurysms underwent surgery via the interhemispheric approach. Eight patients had distal anterior cerebral artery aneurysms and three had anterior communicating artery aneurysms. Subarachnoid hemorrhage was seen in one patient in each aneurysm group. The average aneurysm size was 5.4mm, ranging from 2.9 to 6.8mm. Intraoperative ultrasonographic assistance involved two procedures: before opening the dura mater, the location of the bridging veins was determined using a micro-Doppler flow meter, and then the aneurysm was detected using B-mode ultrasonography with color Doppler imaging and the most appropriate route to the aneurysm was determined. Results: There were no operative complications in this series of aneurysm operations. There was no instance of bridging vein injury in any patient when the dura was opened. The most appropriate route to the aneurysm was revealed by B-mode ultrasonography with color Doppler imaging. Disorientation in searching for the aneurysm was not experienced, and all the aneurysms were successfully clipped. Conclusion: Intraoperative ultrasonographic assistance was a useful method for safer aneurysmal surgery via the interhemispheric approach.
Objective: CEA and CAS are done to treat carotid artery stenosis, but clear eligibility criteria have not been established. In this study we evaluated arterial plaque objectively by IBS analysis with an ultrasound machine with an AD function, and classified the types of arteriosclerotic lesions according to the AHA criteria. Methods: The ultrasoud machine employed was a sonos 5500 with a L7540 probe; system setting gain 50% compression 70% TGC 159 LGC 0). We compared the histopathology in a total of 121 locations using the IBS value in 40 patients (31 men, 7 women) who underwent CEA between May 2002 and September 2003, and calculated the IBS value for hemorrhage, lipid, fibrosis, and calcification. The AHA type distinction classified 24 cases (22 men, 2 women) between November 2003 and June 2004, and its utility was reviewed. Results: We recognized a significant difference between hemorrhage and lipid (P<0.05), lipid and fibrosis (P<0.0001), and fibrosis and calcification (P<0.0001). Each IBS calculated a value with 80% sensitivity: hemorrhage<39 dB, 39 dB≤lipid>45 dB, 45 dB≤ fibrosis<50 dB, 50 dB≤calcification. We carried out ultrasonic diagnosis of 24 case using these values and this yielded 10 cases of AHA Type VI, 4 cases of AHA Type Va, 3 cases of AHA Type Vc, and 4 cases of AHA type Vb. In 3 cases measurement was not possible because of an acoustic shadow due to calcification. Tissue diagnosis yielded 8 cases of AHA Type VI, 7 cases of AHA Type Va, 2 cases of AHA Type Vc, and 4 cases of AHA type Vb. The concordance rate became 86%. The results suggested that this examination is useful for CEA, and choice of stenting.
B-flow imaging allows detailed examination of the carotid artery, and can detect microfloating plaque as areas of high brightness. To date, however, there have been no reports providing conclusive proof of this phenomenon. We describe an 86-year-old man who suffered a transient ischemic attack with right hemiparesis. MRI examination revealed multiple infarctions in diffusion-weighted images. B-flow examination was carried out with a LOGIQ 7 system (GE Yokogawa Medical Systems, Tokyo, Japan). Use of a 3-10-MHz broadband linear array transducer revealed a large piece of floating plaque (7.0m×2.0mm) and a piece of micro floating plaque (1.7mm×0.6mm) in the left common carotid artery. Both pieces of plaque were displayed as areas of high brightness. B-flow imaging uses the coded excitation and tissue equalization method, which enables visualization of the blood flow. Coded excitation shows exaggeration of the small reflected signal from red blood cells. Tissue equalization inhibits the signal from resting or slowly moving objects. The mechanism by which floating plaque is displayed as an area of high brightness suggests that the plaque moves so fast that it is difficult to inhibit its signal by tissue equalization.