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Masahiro Higashi

Publications and source records attributed to Masahiro Higashi.

11 recordsLinked to original sources
PubMed2006

Unblinded pilot study of autologous transplantation of bone marrow mononuclear cells in patients with thromboangiitis obliterans.

BACKGROUND: The short-term clinical benefits of bone marrow mononuclear cell transplantation have been shown in patients with critical limb ischemia. The purpose of this study was to assess the long-term safety and efficacy of bone marrow mononuclear cell transplantation in patients with thromboangiitis obliterans. METHODS AND RESULTS: Eleven limbs (3 with rest pain and 8 with an ischemic ulcer) of 8 patients were treated by bone marrow mononuclear cell transplantation. The patients were followed up for clinical events for a mean of 684+/-549 days (range 103 to 1466 days). At 4 weeks, improvement in pain was observed in all 11 limbs, with complete relief in 4 (36%). Pain scale (visual analog scale) score decreased from 5.1+/-0.7 to 1.5+/-1.3. An improvement in skin ulcers was observed in all 8 limbs with an ischemic ulcer, with complete healing in 7 (88%). During the follow-up, however, clinical events occurred in 4 of the 8 patients. The first patient suffered sudden death at 20 months after transplantation at 30 years of age. The second patient with an incomplete healing of a skin ulcer showed worsening of the lesion at 4 months. The third patient showed worsening of rest pain at 8 months. The last patient developed an arteriovenous shunt in the foot at 7 months, which spontaneously regressed by 1 year. CONCLUSIONS: In the present unblinded and uncontrolled pilot study, long-term adverse events, including death and unfavorable angiogenesis, were observed in half of the patients receiving bone marrow mononuclear cell transplantation. Given the current incomplete knowledge of the safety and efficacy of this strategy, careful long-term monitoring is required for future patients receiving this treatment.

Adult↗
PubMed2006

Multidetector CT angiography using a dual-head power injector and bolus tracking for the diagnosis of aortic aneurysms at reduced contrast material dosage.

RATIONALE AND OBJECTIVES: To establish the utility of multidetector computed tomography (CT) angiography using dual-head power injector in the diagnosis of aortic diseases. METHODS: In a prospective study, 151 patients with aortic diseases were examined by four-detector CT. Scanning was performed using bolus tracking technique. In all patients nonionic contrast was injected at the rate of 1.5 mL/sec. One hundred one patients were examined with dual-head power injector using 0.6 mL/kg contrast flushed by 30 mL of saline solution (group D). Fifty patients were examined with single-head power injector using 1.0 mL/kg contrast only (group S). We evaluated CT values at descending aorta, upper abdominal aorta, abdominal aortic bifurcation, and bilateral common femoral arteries. RESULTS: There were no statistically significant difference of CT values at descending aorta, upper abdominal aorta, abdominal aortic bifurcation, and right common femoral artery. At left common femoral artery, CT values in group D were higher than those in group S with statistically difference (P < .05). In group D, about 40% dose reduction was achieved without reducing image qualities. CONCLUSION: Multidetector CT angiography using dual-head power injector was valuable for the contrast dose reduction of aortic diseases.

Aged↗
PubMed2005

Theoretical study on electronic and spin structures of [Fe2S2](2+,+) cluster: reference interaction site model self-consistent field (RISM-SCF) and multireference second-order Møller-Plesset perturbation theory (MRMP) approach.

Electronic structures of [Fe(2)S(2)(SCH(3))(4)](2-,3-) in DMSO solution are calculated using reference interaction site model complete active space self-consistent field (RISM-CASSCF)/multireference second-order Møller-Plesset perturbation theory (MRMP) method. For the reduced state, we obtain both the low-spin Fe(3+)Fe(2+) localized and high-spin Fe(2.5+)Fe(2.5+) delocalized forms, which are very close in energy. The spin interaction constants obtained from the energies of states with various spin multiplicities are in good agreement with the available experimental estimates both for the oxidized and for the reduced states. The dynamic electron correlation effect is found to be important in estimating the spin interaction between the Fe ions. The redox potentials are calculated to be 2.87 and 2.78 eV for the localized and delocalized reduced states, respectively, which are close to the experimental values. We devise a simple model for calculating the free energy curves of the reduction process based on the RISM-SCF theory. The activation barrier height is calculated to be 7.4 kcal/mol at the equilibrium geometry of oxidized state, indicating that the reduction reaction will occur efficiently in DMSO solvent. The effect of solvent fluctuation on the free energy profiles is discussed on the basis of the present calculations.

Iron↗
PubMed2005

Experience of temporary inferior vena cava filters inserted in the perinatal period to prevent pulmonary embolism in pregnant women with deep vein thrombosis.

OBJECTIVE: We placed temporary inferior vena cava filters to prevent pulmonary thromboembolism in patients with deep vein thrombosis (DVT) who were presumed to have an increased risk of pulmonary embolism in the perinatal period. These experiences of using temporary inferior vena cava filters in pregnant women are reported. METHODS: We reviewed 11 patients with DVT who underwent placement of a temporary inferior vena cava filter and delivered in our hospital between 1998 and 2004. All of the filters were placed at the suprarenal inferior vena cava before delivery. During filter placement, anticoagulant therapy was routinely performed, and we stopped the administration of anticoagulant agents intrapartum. RESULTS: No complications occurred at filter insertion or during placement. No symptomatic pulmonary thromboembolism occurred during or after delivery. All of the filters were successfully removed, one of which was exchanged for a permanent filter because the temporary filter captured a large thrombus. CONCLUSION: Intrapartum temporary inferior vena cava filters may reduce the incidence of pulmonary thromboembolism in pregnancy with DVT. Temporary inferior vena cava filters appear to be safe for pregnant women.

Adult↗
PubMed2005

Detection of aortic graft infection by fluorodeoxyglucose positron emission tomography: comparison with computed tomographic findings.

OBJECTIVE: Radionuclide imaging with fluorodeoxyglucose (FDG) and positron emission tomography (PET) has been proposed for the identification of vascular graft infection; however, its accuracy has not been determined. We performed this prospective study to compare the usefulness of FDG-PET in the assessment of vascular graft infection relative to computed tomography (CT). METHODS: FDG-PET was performed for 33 consecutive patients with a suspected arterial prosthetic graft infection. The PET images were then assessed visually in terms of the density of uptake. In cases with positive uptake, the pattern of accumulation was also defined, such as focal or diffuse uptake. We compared the diagnostic efficiency of PET with contemporaneous CT in detection of infection of the arterial prosthetic graft. RESULTS: On the basis of the surgical, microbiological, and clinical follow-up findings, the aortic grafts were considered infected in 11 patients and not infected in 22 patients. Although the sensitivity of PET (91%) was higher than that of CT (64%), its specificity (64%) was lower than that of CT (86%). When focal uptake was set as the positive criterion in FDG, the specificity and positive predictive value of PET for the diagnosis of aortic graft infection improved significantly to 95% (P < .05 for both). CONCLUSIONS: Although both techniques are useful in evaluation of patients with suspected aortic graft infection, using the characteristic FDG uptake pattern described previously as a diagnostic criterion made the efficacy of FDG superior to that of CT in the diagnostic assessment of patients with suspected aortic graft infection.

Adult↗
PubMed2004

A small pulmonary arteriovenous malformation as a cause of recurrent brain embolism.

We report a case of recurrent paradoxical brain embolism mediated through a small pulmonary arteriovenous malformation (PAVM) with a 1.8-mm-diameter feeding artery. In this case, the further recurrent stroke was prevented successfully by PAVM embolization. Although embolization therapy is currently recommended only for PAVMs with feeding arteries greater than 3 mm in diameter, the therapy may be needed also in the smaller PAVMs.

Aged↗
PubMed2004

[Early application of the lung protective ventilation strategy at different stages in two ARDS patients].

We experienced 2 patients with acute respiratory distress syndrome (ARDS) from pneumonia after intervention for subarachnoidal hemorrhage. We applied lung protective ventilation strategy (LPVS) on both cases: a tidal volume less than 6 ml x kg(-1) ideal body weight and PEEP at 10-15 cmH2O. Although etiology and degree of hypoxia were very similar in two patients when ARDS was diagnosed, clinical course was quite different. The patient in whom LPVS had been started on the 5th day of ARDS required mechanical ventilation of 23 days. In contrast, another patient in whom LPVS had been started on the 16th day of ARDS required mechanical ventilation of 219 days. PaCO2 during LPVS with permissive hypercapnia in the latter patient increased up to 161 mmHg but no adverse effect was observed. These cases suggest that early application of the LPVS may be important to improve respiratory outcomes of ARDS patients.

Aged↗
PubMed2004

Time-of-flight MR angiography targeted to coiled intracranial aneurysms is more sensitive to residual flow than is digital subtraction angiography.

BACKGROUND AND PURPOSE: For intracranial aneurysms treated with Guglielmi detachable coils, long-term follow-up is mandatory because coil compaction may occur and aneurysms may recur. The purpose of this study was to establish a noninvasive technique to visualize residual flow in coiled aneurysms. METHODS: We designed a 3D time-of-flight (3D-TOF) MR angiography (MRA) technique targeted to depict coiled aneurysms that employed a very short TE (1.54-1.60 ms) and a high spatial resolution (0.3 x 0.3 x 0.3 mm3 with zero-filling) to diminish spin dephasing. To diminish spin saturation, image volume was carefully positioned so that the neck of the targeted aneurysm was within 2 cm of the inflow portion along the stream of blood. Fifty-one MRA images of 39 coiled aneurysms in 39 patients were compared with digital subtraction angiography (DSA) images. DSA and MRA findings were interpolated retrospectively for parent and branch arteries' patency, as well as residual flow in aneurysms. In the latest 11 MR studies, a dark-blood 3D turbo spin-echo sequence was added to MRA to negate the effect high-signal-intensity thrombus. RESULTS: MRA visualized all parent and branch arteries with DSA confirmation. MRA visualized residual flow more frequently (38 studies) than did DSA (25 studies). Residual flow space visualized with MRA was always similar to or larger than that with DSA. The dark-blood sequence completely suppressed intraluminal high signal intensity on MRA images and confirmed that the high signal intensity was not due to thrombus. CONCLUSION: TOF MRA targeted to depict coiled intracranial aneurysms is noninvasive and superior to DSA in visualization of residual flow and, hence, useful for follow-up of coiled aneurysms.

Aged↗
PubMed2003

Rapid evaluation of right and left ventricular function and mass using real-time true-FISP cine MR imaging without breath-hold: comparison with segmented true-FISP cine MR imaging with breath-hold.

PURPOSE: To evaluate the accuracy of cardiac function measured with real-time true fast imaging with steady-state precession (True-FISP) cine without breath-hold compared with those measured from segmented True-FISP cine with breath-hold. METHODS: Eighteen consecutive patients and six healthy volunteers were enrolled in the study group. Both real-time multislice True-FISP cine imaging without breath-hold and single-slice segmented True-FISP cine imaging with multiple breath-holds were performed in short-axis imaging sections to encompass the entire ventricles. Vertical long-axis cine imaging using real-time True-FISP cine sequence without breath-hold was performed to evaluate heart motion during respiration in 13 subjects. Ventricular volume and mass were evaluated by four observers independently with manual tracing. RESULTS: Real-time True-FISP cine quality was sufficient for contour detection in all 24 subjects. Cardiodynamic measurements based on real-time True-FISP cine correlated well with those based on segmented True-FISP cine [left ventricular (LV) end-diastolic volume: r = 0.98; LV end-systolic volume: r = 0.98; LV ejection fraction: r = 0.91; LV mass: r = 0.96; right ventricular (RV) end-diastolic volume: r = 0.89; RV end-systolic volume: r = 0.94; RV ejection fraction: r = 0.79]. Intra- and interobserver variability were sufficiently small in real-time True-FISP cine without breath-hold. Heart motion during respiration along the long axis of the left ventricle (2.2 mm to 3.7 mm) was much less than the slice interval (10 mm), confirming that misregistration of slice position during respiration was low. CONCLUSION: Real-time True-FISP cine without breath-hold has high reproducibility and is applicable to patients with severe cardiac dysfunction and/or arrhythmias.

Adolescent↗
PubMed2002

[Single breath-hold three-dimensional MR coronary angiography with true FISP].

Single breath-hold MR coronary angiography with three-dimensional (3D) true FISP was performed in 6 volunteers. Every scan was performed in a single breath-hold, and no contrast material was used. The length of visualized vessels was 12.2 +/- 1.2 cm for the RCA and 6.6 +/- 1.1 cm for the LAD. The signal-to-noise ratio and contrast-to-noise ratio were 22.8 +/- 6.8 and 17.5 +/- 7.1, respectively. MR coronary angiography with 3D true FISP has the potential to obtain good coronary angiograms for the screening of coronary artery disease.

Adult↗