An Operating Microscope with Higher Magnification and Higher Resolution for Cerebral Aneurysm Surgery: Preliminary Experience—Technical Note

We describe a higher magnifying power operating microscope system to improve one method of high-quality microsurgical clipping for cerebral aneurysm in some cases. This higher magnification is achieved by a new lens design in the optical system, which makes the image of the object very clear at high magnifications (distinctiveness of 7 μm). This higher-resolution operating microscope system provides the surgeon with higher-magnified images (at the maximum of more than 30× magnifications as each working distance) in the operating field. The magnifications can be changed from low power (2.9×) to high power (62.0×) depending on the circumstances in a given procedure. We have used this operating microscope system on 11 patients with microsurgical clipping for cerebral aneurysms. Microsurgical treatment could be performed safely and precisely. All aneurysms were treated without any technical complications. We think that the use of this microscope would have potential benefits for microsurgical treatment for cerebral aneurysms because of better visualization.     

3D Turbo Spin-echo MRI-based Mechanical Thrombectomy at Middle Cerebral Artery Bifurcations

We describe three cases with acute middle cerebral artery (MCA) occlusion. From the pre-operative MRI, including three-dimensional turbo spin-echo sequences using T1WI and T2WI, we assessed both thrombus configuration and arterial anatomy at the MCA bifurcations. For efficient endovascular thrombectomy, we identified the applied MCA segment 2 (M2) branch, in which the main thrombus was buried. Sufficient recanalization after a single pass was achieved and the patients made a marked recovery. Although mechanical thrombectomy for M2 occlusion has not been of proven benefit, the endovascular procedure based on three-dimensional turbo spin-echo imaging is useful for more complete thrombus removal at MCA bifurcations.     

Bioavailability of glycyrrhizin from Shaoyao-Gancao-Tang in laxative-treated rats

Shaoyao-Gancao-Tang (SGT), a traditional Chinese formulation composed of Shaoyao (Paeoniae Radix) and Gancao (Glycyrrhizae Radix), is frequently used in conjunction with laxatives such as sodium picosulfate in colonoscopy to relieve abdominal pains. We have investigated the alterations of the bioavailability of glycyrrhizin when SGT was co-administered with sodium picosulfate and we tried to identify a regimen that might minimize the alterations. Glycyrrhizin is one of the active glycosides in Gancao and SGT and is hydrolysed into the bioactive metabolite, 18 beta-glycyrrhetic acid (GA) by intestinal bacteria following oral administration. We found that the maximum plasma concentration (C(max)) and the area under the mean concentration vs time curve from zero to 24 h (AUC(0-24 h)) of GA from a single dose of SGT administered 5 h after a single pretreatment with sodium picosulfate were significantly reduced to 15% and 20% of the control level in rats, respectively. These reductions were still significant four days after sodium picosulfate pretreatment, but were restored by repetitive administration of SGT following sodium picosulfate pretreatment. Similar reductions and recovery were observed for the glycyrrhizin-metabolizing activity of intestinal bacteria in rat faeces. The results warrant clinical studies for co-administration of laxatives such as sodium picosulfate and SGT.     

Saiko-ka-Ryukotsu-Borei-To inhibits intimal thickening in carotid artery after balloon endothelial denudation in cholesterol-fed rats

Oral administration of Saiko-ka-Ryukotsu-Borei-To (SRB), a traditional Chinese formulation, dose dependently inhibited intimal thickening in carotid artery injured by balloon endothelial denudation in cholesterol-fed rats. SRB also inhibited vascular smooth muscle cell (VSMC) proliferation, which is assessed by counting the VSMCs immunoreactive with antiproliferating cell nuclear antigen (PCNA) antibody in the intimal area. VSMC proliferation is considered to play a central role in the development of intimal thickening. SRB slightly, but not significantly, reduced serum total cholesterol and low-density lipoprotein cholesterol. These results indicate that the suppressive effect of SRB on intimal thickening may result from its inhibitory effect against VSMC proliferation, but does not depend on lowering of lipid levels. The balloon injury model used in this study has similar pathological processes to restenosis after percutaneous coronary intervention (PCI). Therefore the present results may provide a new therapeutic strategy using SRB to reduce restenosis after PCI in the treatment of patients with ischemic coronary artery disease. Furthermore, since it is considered that artery restenosis after balloon injury in PCI is "accelerated atherosclerosis, " SRB may have beneficial effects in atherosclerosis that develops over a long clinical course in hyperlipidemia, diabetes, etc.     

A pair of crude drugs used in Shang-Han-Lun, especially the ways of using roasted licorice

The frequency and usage of "Yao-dui" (pair of two kinds of crude drugs, Yaku-tai used in Shang-Han-Lun, a famous formulary in traditional Chinese medicine, was examined. The best ten kinds of pairs of two crude drugs frequently mentioned in the formulary were those among five drugs contained in Guizhi-tang (Keishi-to in Japanese), which is a major formulation in Shang-Han-Lun. Radix Glycyrrhizae Preparata (Sha-kanzo in Japanese) and Ramulus Cinnamomi (Keishi in Japanese) were used in pairs very frequently, which is used for the treatment of palpitation caused by Xin-yang deficiency (Shin-yo-kyo in Japanese) and usually used with Poria. Radix Glycyrrhizae Preparata and Radix Paeoniae worked in pairs for the treatment of muscular spasm and pain due to Xue-deficiency-syndrome (Kekkyo in Japanese). Radix Glycyrrhizae Preparata is used together with Rhizoma Zingiberis (Kankyou in Japanese) for the treatment of diarrhea accompanied with cold pain in the lower abdomen and usually used with Radix Ginseng and Aconiti Preparata. The experimental knowledge of the usage of these crude drug pairs will be useful to create a new formulation of crude drugs for modern medical treatment.     

A new method of immobilization after traumatic anterior dislocation of the shoulder: a preliminary study

This preliminary prospective study was conducted to determine whether immobilization with the arm in external rotation would decrease the rate of recurrence after initial traumatic anterior dislocation of the shoulder. Forty patients with initial shoulder dislocations were assigned to (1) conventional immobilization in internal rotation (IR group, n = 20) or (2) a new method of immobilization in external rotation (ER group, n = 20). The recurrence rate was 30% in the IR group and 0% in the ER group at a mean 15.5 months. The difference in recurrence rate was even greater among those who were aged less than 30 years (45% in the IR group and 0% in the ER group). Immobilization with the arm in external rotation is effective in reducing the rate of recurrence after initial dislocation of the shoulder.     

Antispasmodic activity of licochalcone A, a species-specific ingredient of Glycyrrhiza inflata roots

Licochalcone A, a species-specific and characteristic retrochalcone ingredient of Glycyrrhiza inflata root, has been shown to possess multiple bioactive properties. However, its muscle relaxant activity has not been reported previously. Licochalcone A showed a concentration-dependent relaxant effect on the contraction induced by carbachol (50% effective concentration (EC50) = 5.64 +/- 1.61 microM), KCl (EC50 5.12 +/- 1.68 microM), BaCl2 (EC50 1.97 +/- 0.48 microM) and A23187 (EC50 2.63 +/- 2.05 microM). Pretreatment with licochalcone A enhanced the relaxant effect of forskolin, an adenylyl cyclase activator, on the contraction in a similar manner to 3-isobutyl-1-methylxanthine (IBMX), a phosphodiesterase (PDE) inhibitor. Furthermore, the IC50 (22.1 +/- 10.9 microM) of licochalcone A against cAMP PDE was similar to that of IBMX (26.2 +/- 7.4 microM). These results indicated that licochalcone A may have been responsible for the relaxant activity of G. inflata root and acted through the inhibition of cAMP PDE.     

Effects of Chronotropic Responsive Cardiac Pacing on Ventilatory Response to Exercise in Patients with Complete AV Block

To identify the effect of chronotropic responsive cardiac pacing on the ventilatory response to exercise, ten selected patients with complete atrioventricular block underwent paired cardiopulmonary exercise tests in fixed rate ventricular (WI) and dual chamber (DDD) or rate responsive ventricular (VVIR) pacing modes. Compared to VVI pacing, DDD or VVIR pacing increased peak oxygen uptake (P < 0.005) and augmented anaerobic threshold (P < 0.001), In eight patients, dyspnea was the major symptom limiting exercise with VAT pacing and this was markedly attenuated with DDD or VVIR pacing. In all patients, ventilation (VE) and the ratio of ventilation to CO₂ production (VE/VCO₂) were consistently higher with VVI pacing during exercise. To compare the response of the two pacing modes at the same workloads in an aerobic condition, we measured ventilatory variables 1 minute prior to the anaerobic threshold obtained with VVI pacing. When DDD or VVIR pacing was compared with VVI pacing, VE and VE/VCO₂ significantly decreased from 20.5 ± 5.3 L/min to 18.3 ± 5.0 L/min (P < 0.005) and from 35.9 ± 5.8 to 31.9 ± 5.0 (P < 0.003), respectively. Respiratory frequency rose significantly more with VVI pacing (P < 0.001) despite an unchanged tidal vohame. Although peak VE did not differ between the two pacing modes, VE/VCO₂ at the peak exercise increased significantly more with VVI pacing (P < 0.005). Respiratory frequency also rose more with VVI pacing (P < 0.005) and tidal volume did not change. This study suggests that chronotropic responsive cardiac pacing attenuates the exertional dyspnea by improving the ventilatory response to exercise as well as increasing the cardiac output in patients with complete atrioventricular block.