Biomedical subjects
Publications and source records attributed to Takehiro Inoue.
A 47-year-old female intentionally inserted needles through her chest wall, resulting in cardiac trauma. One week later, cardiac tamponade occurred. The needles were detected and removed successfully by thoracotomy. During the operation, fluoroscopy was used to locate the needles and greatly facilitated their successful removal.
Renal hypothermia achieved using cold (4 degrees C) heparinized Ringer's lactate is an effective method of preventing renal compromise during abdominal aortic surgery. We present the case of a 62-year-old man with an abdominal aortic aneurysm (AAA), complicated by involvement of an ectopic right renal artery with a low abdominal aortic origin and passage across the ventral side of the inferior vena cava. The patient underwent AAA repair and right renal artery reconstruction using renal perfusion with cold heparinized Ringer's lactate, and no deterioration of renal function occurred.
Papillary muscle rupture complicating acute myocardial infarction leads to mitral regurgitation and is associated with significant mortality. We experienced a case involving massive mitral regurgitation caused by complete anterior papillary muscle rupture following acute lateral myocardial infarction. A 75-year-old woman developed heart failure shortly after her admission, and the diagnosis was confirmed by echocardiography and cardiac catheterization. Under intra-aortic balloon pumping, the patient underwent emergency mitral valve replacement and coronary revascularization. Her postoperative course was uneventful, and she was discharged on the 40th postoperative day. We believe that prompt surgical treatment should be performed even in stable patients with ischemic mitral regurgitation, given that deterioration may be sudden and unpredictable especially in cases involving complete papillary muscle rupture.
PURPOSE: To evaluate the treatment results of low-dose-rate (LDR) and high-dose-rate (HDR) interstitial brachytherapy (ISBT) for T3 mobile tongue cancer. MATERIAL AND METHODS: Between 1974 and 1992, 61 patients with T3 mobile tongue cancer were treated with LDR ISBT using (192)Ir hairpins with or without single pins. In addition, between 1991 and 1999, 14 patients were treated with HDR ISBT. For nine patients treated with ISBT alone, the total dose was 59-94 Gy (median 72 Gy) within one week in LDR ISBT and 60 Gy/10 fractions/5 days in HDR ISBT. For 66 patients treated with a combination therapy of external beam radiotherapy (EBRT) and ISBT, the total dose was 12.5-60 Gy (median 30 Gy) of EBRT and 50-112 Gy (median 68 Gy) within 1 week in LDR ISBT or 32-60 Gy (median 48 Gy)/8-10 fractions/5-7 days in HDR ISBT. RESULTS: The 2- and 3-year local control rates of all patients were both 68%. The 2- and 3-year local control rates of patients treated with LDR ISBT were both 67%, and those with HDR ISBT were both 71%. The local control rate of patients treated with HDR ISBT was similar to those with LDR ISBT. CONCLUSIONS: ISBT for T3 mobile tongue cancer is effective and acceptable. The treatment result of HDR ISBT is almost similar to that of LDR ISBT for T3 mobile tongue cancer.
Heavy-ion beams are more effective than gamma-rays in causing G2 arrest. In this study, we investigated the expression of Wee1 and Cdc2 protein levels in order to analyze the G2 arrest caused by carbon-ion beam irradiation. Human lymphoblastoid TK6 cells were exposed to a 75 keV carbon-ion beam or 137Cs gamma-rays. Although the levels of Wee1 and Cdc2 protein were increased after exposure to either beam, Wee1 protein levels were influenced more by carbon-ion beam irradiation than by gamma-rays. To the contrary, Cdc2 protein levels were increased more by gamma-rays than by carbon-ion beams. These findings suggest that the G2 arrest produced by heavy-ion beams, such as the carbon-ion irradiation used in this study, might be associated with the overexpression of the Wee1 protein and of Cdc2 phosphorylation regulated by Wee1. Together, these events may act to prolong the length of G2 arrest.
PURPOSE: The aim of this study was to compare the results of high-dose rate (HDR) and medium-dose rate (MDR) intracavitary brachytherapy for carcinoma of the uterine cervix on the basis of a prospective study and to determine the dose rate conversion factor (DRCF) from low-dose rate (LDR) to MDR via HDR, because a DRCF of 0.54 from LDR to HDR has been widely accepted. MATERIALS AND METHODS: Between August 1991 and July 1999, 104 patients were entered into this trial to compare results between HDR (n=54) and MDR (n=50). Three patients were excluded from this study, leaving 54 HDR patients and 47 MDR patients eligible. Method and dose of external beam radiotherapy were the same for both groups. For HDR intracavitary brachytherapy, point A dose was adjusted to 32 Gy/4 fractions for stages I and II, to 30 Gy/4 fractions for stage III, and to 22.5 Gy/3 fractions for stage IV. The corresponding values for MDR were 35.6 Gy/4 fractions, 34 Gy/4 fractions, and 25.5 Gy/3 fractions. The average dose rate at point A was 30 Gy/hour (9.0-65.2) for HDR and 1.7 Gy/hour (1.3-2.2) for MDR. We assumed a DRCF of 0.9 from MDR to HDR. RESULTS: The 3-year cause-specific survival rates for HDR were 85%, 83%, 75%, and 0% for stages I, II, III, and IV, respectively. The corresponding figures for MDR were 100%, 82%, 58%, and 40%. Six of the HDR patients (11%) and 2 of the MDR patients (4%) developed Kottmeier's grade 2 or 3 late complications. A DRCF of 0.6 from LDR to MDR could be derived from a DRCF of 0.9 from MDR to HDR and one of 0.54 from LDR to HDR. CONCLUSIONS: There were no statistically significant differences in cause-specific survival and incidence of late complications between HDR and MDR. A DRCF of 0.6 from LDR to MDR could be determined. However, because the results of this trial were preliminary, a further study is needed.
Although malignant lymphoma of the breast is a rare disease, we recently experienced a high incidence of central nervous system (CNS) involvement. Thus, we retrospectively reviewed clinical records of 921 patients with breast tumors, treated from 1990 to 2002, to examine CNS involvement. Eight patients were found to have malignant lymphomas during this period. Of these, four patients ranging from 46 to 80 years of age had CNS involvement, one with Burkitt type and three with diffuse large B-cell lymphoma. The patients received surgery and/or chemotherapy and/or radiotherapy. The four other patients without CNS involvement are alive without tumor, whereas three of four patients with CNS involvement died of the disease. It should be noted that CNS involvement in breast lymphoma is not so rare. It is difficult, but important, to determine whether malignant lymphoma of the breast originates in the breast or is of systemic origin. Although brain metastasis could be treated effectively by radiotherapy and/or chemotherapy, the prognosis was poor. Further intensive treatment is required for breast malignant lymphoma with CNS involvement.
To examine the compatibility of low dose rate (LDR) with high dose rate (HDR) brachytherapy, we reviewed 399 patients with early oral tongue cancer (T1-2N0M0) treated solely by brachytherapy at Osaka University Hospital between 1967 and 1999. For patients in the LDR group (n = 341), the treatment sources consisted of Ir-192 pin for 227 patients (1973-1996; irradiated dose, 61-85 Gy; median, 70 Gy), Ra-226 needle for 113 patients (1967-1986; 55-93 Gy; median, 70 Gy). Ra-226 and Ir-192 were combined for one patient. Ir-192 HDR (microSelectron-HDR) was used for 58 patients in the HDR group (1991-present; 48-60 Gy; median, 60 Gy). LDR implantations were performed via oral and HDR via a submental/submandibular approach. The dose rates at the reference point for the LDR group were 0.30 to 0.8 Gy/h, and for the HDR group 1.0 to 3.4 Gy/min. The patients in the HDR group received a total dose of 48-60 Gy (8-10 fractions) during one week. Two fractions were administered per day (at least a 6-h interval). The 3- and 5-year local control rates for patients in the LDR group were 85% and 80%, respectively, and those in the HDR group were both 84%. HDR brachytherapy showed the same lymph-node control rate as did LDR brachytherapy (67% at 5 years). HDR brachytherapy achieved the same locoregional result as did LDR brachytherapy. A converting factor of 0.86 is applicable for HDR in the treatment of early oral tongue cancer.
PURPOSE: Cardiac leads that became infected, fail, or are otherwise problematic present difficulties in the management of patients. In this report, we assess our intravascular countertraction technique. METHOD: Between February 1990 and January 2001, 13 leads were removed from 11 patients using the intravascular countertraction technique. The reasons for lead extraction were pacemaker infection and lead dysfunction. RESULTS: In two of these patients, the ventricular leads could not be completely removed. The complete success rate was 85% and the overall success rate was 92%. There were no serious complications such as cardiac rupture, vein injury, or death, and there were no clinical signs of pulmonary embolism. In one of the patients whose ventricular leads could not be removed completely, the ventricular lead was stretched from its previous round shape, but tricuspid valve regurgitation did not occur during the 3-year follow-up period. In the other patient, the distal electrode was left in the subclavian vein. However, this residual distal electrode did not migrate, and there were no clinical signs of any recurrence of infection. CONCLUSIONS: The present study suggests that to remove leads successfully, the largest locking stylet that can be easily passed to the lead's tip through the coil lumen should be chosen in order to avoid valve injury, which can sometimes occur when a ventricular lead's locking stylet is left in the coil lumen.
The management of patients with acute pulmonary embolism (PE) remains controversial, despite an improved understanding of its pathogenesis and diagnosis. Haemodynamic instability due to right ventricular failure and hypoxia following PE is associated with a high mortality rate. This report describes a case of a 22-year-old woman with leukaemia in which percutaneous cardiopulmonary support (PCPS) was used as an adjunct to thrombolytic therapy in the treatment of right ventricular thrombus with acute PE. The patient has since undergone regular follow-up on an outpatient basis without showing any recurrence of thromboembolism at 2 years postoperatively. This experience suggests that supportive PCPS may provide favourable clinical outcomes in high-risk patients with severe PE.
The effect on myocardial reperfusion injury of reducing oxygen tension during reperfusion on cardiopulmonary bypass (CPB) in coronary artery bypass grafting (CABG) was examined at the same time as the influence of diltiazem during CPB was evaluated. A prospective, randomized trial evaluated the hemodynamic and myocardial metabolic recovery in 3 groups of patients undergoing elective CABG; subjects were randomly allocated on the basis of oxygen tension during reperfusion after aortic unclamping: group 1 (n=10) hyperoxic reperfusion (oxygen tension [PO2]=450-550 mmHg); group 2 (n=10): hyperoxic reperfusion and subsequent continuous infusion of diltiazem (0.5 microg/kg); group 3 (n=10): lowering reperfusate PO2 (PO2=200-250 mmHg). Hemodynamic and myocardial metabolic measurements were taken at 6 preset times: before starting the surgical procedure and at 30 min and 3, 9, 21, and 45 h after discontinuation of CPB. The cardiac index in the lowering reperfusate PO2 group was higher than that of the hyperoxic reperfusion groups at 30 min and 3 h after CPB, and malondialdehyde and troponin-T were significantly lower at 30 min and 3 h, respectively. In comparison with the hyperoxic + diltiazem group, the hemodynamic and myocardial recovery in the lowering reperfusate PO2 group was improved for about 3 h after CPB. Reduced oxygen tension during reperfusion after aortic unclamping on CPB is more effective against myocardial injury than a calcium antagonist in the short term. It is a convenient and safe management technique that can reduce morbidity and mortality, especially in the severely compromised heart.
The technique of extensive endoatriectomy of the left atrium and reconstruction with autologous pericardium for infective endocarditis is described. Endocardium of the left atrium with vegetations was completely excised from the valvular annulus to normal endocardium, and autologous pericardium was used to reinforce the endocardial defect and to allow less tension in the closure. This technique permits complete removal of infectious lesions and facilitates mitral valve replacement reinforcing the mitral annulus.
The CyberKnife is an image-guided robotic system designed for stereotactic radiosurgery. This system uses a lightweight, x-band linear accelerator, computer-controlled robotic arm, a pair of orthogonal x-ray imagers (TLS: Target Locating System), and a computer workstation. During the treatment, the TLS determines the location of the lesion and communicates these coordinates to the robot. The robot adjusts the position of the beam to the target. The accuracy of this system is 0.7 mm (median) at Osaka University. The CyberKnife system offers new options for radiosurgery/therapy. Stereotactic fractionated radiotherapy can now be performed with the same accuracy as single-fraction stereotactic radiosurgery. The frameless nature of CyberKnife allows tumors in the chest and abdomen to be treated as well. The real time tracking system option enables one to treat tumors that move with respiration, such as lesions in lung. Tumors in the lower spine, pancreas, and lung have already been treated in the USA. A description of the components, accuracy, and future of the CyberKnife will be presented.
alpha-Cyclodextrin specifically inhibited raw starch digestion by Bacillus subtilis 65 alpha-amylase. The raw starch digestibility and alpha-cyclodextrin-Sepharose 6B adsorbability of this alpha-amylase were simultaneously lost when the specific domain corresponding to the affinity site essential for raw starch digestion was deleted by proteolysis. Occurrence of the affinity site on raw-starch-digesting enzymes was proven also with bacterial amylase.
Long-term results of physiologic atrial pacing have been analyzed for the possibility of avoiding the recurrence of paroxysmal atrial fibrillation and the progression to chronic permanent atrial fibrillation in patients with paroxysmal atrial fibrillation related to sick sinus syndrome. Seventy four patients were evaluated and divided into two groups; 39 patients underwent atrial pacing (AAI, 53%) and 35 had ventricular pacing by single-lead pacing (VVI, 47%). All patients had been evaluated periodically on an out-patient basis by 24 hour Holter monitoring. Basic rhythms in all AAI patients were based on atrial pacing, resulting from the suppression of paroxysmal atrial fibrillation. Basic rhythms in the VVI paced patients were variable, consisting of regular sinus rhythm, transient atrial fibrillation, and ventricular pacing in 30 of 35 patients in the VVI group. The remaining five patients progressed to chronic permanent atrial fibrillation (0% in AAI vs. 14% in VVI, p < 0.05). Thromboembolic complications were not observed in the AAI pacing group. Three patients demonstrated thromboembolic complications (0% in AAI vs. 8.6% in VVI, p < 0.05). The effect of preventing paroxysmal atrial fibrillation and the progression to chronic atrial fibrillation was evident in the AAI paced group, but VVI pacing cannot prevent paroxysmal atrial fibrillation and chronic atrial fibrillation. In addition, potential risks of thromboembolic complications caused by atrial fibrillation were not decreased in VVI paced patients.
Our purpose in this study was to determine the influence of radiotherapy, especially brachytherapy, on the activity of natural killer cells (NK). We examined changes in NK activity before and after radiotherapy in 27 patients who underwent radiotherapy with or without brachytherapy, comprising of 16 cases of cervical cancer (three recurrences), 5 of prostate cancer, 4 of esophageal cancer and 2 of tongue cancer. Fourteen intracavitary procedures (for 13 cervical cancers and 1 esophageal cancer) and 10 interstitial brachytherapy (for 3 cases of recurrent cervical cancer, 5 of prostate cancer and 2 of tongue cancer) were performed with Ir-192 microSelectron HDR and Selectron Cs-137. External radiotherapy consisted of 10 MV X-ray administration for 13 cases of cervical cancer and 4 of esophageal cancer. The number of white blood cell was reduced by radiotherapy from 5065 +/- 2002 count/ml to 4281 +/- 1392 count/ml (p=0.02), that of lymphocytes from 1518 +/- 817 to 762 +/- 409 /ml (p<0.0001), and that of CD 16+ cells from 274 +/- 197 to 14 +/- 96 (p=0.03). No significant change was observed in the number of CD 56+ cells (274 +/- 166 to 211 +/- 153 /ml). Overall NK activity was reduced by radiotherapy from 37 +/- 19% to 30 +/- 19% (p=0.001). External radiotherapy with or without brachytherapy reduced NK activity from 33 +/- 18% to 23 +/- 16% (p=0.004). However interstitial brachytherapy produced little change in NK activity from 42 +/- 18 to 39 +/- 19%). Radiotherapy reduced the number of white blood cell, lymphocyte and CD 16+ cells. Although external radiotherapy suppressed NK activity, only brachytherapy showed little influence on NK activity alteration.
This study examined the applicability of endovascular brachytherapy to larger del arteries such as the abdominal aorta and iliac artery. Endovascular brachytherapy using an Ir-192 HDR source was administered 11 times to nine patients who had undergone percutaneous transluminal angioplasty (PTA) between 1995 and 1999. The follow-up lasted 13 to 55 months after treatment (median, 24 months). Eight of the 11 lesions have been controlled so far. Although one case developed thrombus inside the stent five months later, recanalization was achieved by means of retreatment. One patient who underwent low-dose irradiation (6 Gy) without stent implantation showed restenosis five months after treatment. We used a centering catheter that did not block the blood stream for exact centering of the radiation source in larger vessels such as the abdominal aorta. Although endovascular brachytherapy is a promising and safe procedure, careful follow-up is needed to detect untoward reactions such as thrombosis.
BACKGROUND: The CyberKnife provides a new technique for performing frameless stereotactic irradiation. So far, few reports have been published on clinical outcomes obtained with the CyberKnife. This report summarizes our clinical experience with CyberKnife irradiation for metastatic brain tumors. MATERIALS AND METHODS: Seventy-seven lesions (48 patients) were evaluated and analyzed, and 66 lesions in 41 patients were treated with stereotactic radiosurgery (SRS). The prescribed dose was 9 to 30 Gy. RESULTS: Freedom from progression of the tumors was more likely with a prescribed dose of at least 24 Gy than with one of less than 20 Gy (p=0.0244; log-rank test). The CR (complete response) rate was significantly higher when D99 was at least 24 Gy (p=0.0045). There were no severe side effects. CONCLUSION: Stereotactic irradiation with the CyberKnife for metastatic brain tumors is effective and safe. D99 should be at least 24 Gy for CyberKnife SRS treatment.