Biomedical subjects

Y Takanashi

Publications and source records attributed to Y Takanashi.

At least 37 records · Page 2Linked to original sources

PubMed2001

[Translocation of the aortic valve for aortic stenosis in a patient with severe calcification in the aortic root: report of a case].

A 65-year-old woman was admitted to the hospital because of anterior chest pain. Computed tomography and transthoracic 2-D echocardiogram demonstrated aortic valvular stenosis with calcification of whole aortic root. Cardiac catheterization study showed a transaortic pressure gradient of 73 mmHg and coronary angiography showed 75% stenosis at the right coronary ostia. Aortic valve replacement and coronary artery bypass grafting were planned. At operation, sinotubular junction and bilateral coronary ostia severely calcified with stenosis, prompted us to translocate the aortic valve with the composite graft, a 19 mm Bicarbon prosthesis and 25 mm woven Dacron graft. The postoperative course was uneventful. On cardiac catheterization done 27 days after operation, satisfactory valve motion and patent coronary bypass grafts were confirmed.

Aged↗

PubMed2000

Anatomic biventricular correction by taking down bicaval Glenn shunt.

A 7-year-old boy underwent ventricular and atrial septal defect patch closures, pulmonary valvulotomy, left pulmonary artery dilatation, and bicaval Glenn shunt, which maintained good patency between the superior vena cava and right atrium, because of a reduced right ventricular end-diastolic volume (RVEDV). The RVEDV had increased at 15 years of age; therefore, we performed an anatomic biventricular correction by removing the bicaval Glenn shunt. We found that anatomic biventricular correction becomes possible if RVEDV increases postoperatively.

Adolescent↗

PubMed2000

Clinical efficacy of heparin-bonded bypass circuits related to cytokine responses in children.

BACKGROUND: Cardiopulmonary bypass (CPB) induces numerous systemic reactions. This study examined the efficacy of heparin-bonded CPB circuits on inflammatory responses and postoperative status in children. METHODS: Thirty-four infants undergoing elective cardiac surgery were randomly divided into two groups: a heparin-bonded CPB group (n = 17) and a non-heparin-bonded group (n = 17). Plasma levels of the inflammatory cytokines were measured before, during, and after CPB, and postoperative status was determined by examining the respiratory index, blood loss, and the post- and preoperative body weight percent ratio. RESULTS: Significant differences in tumor necrosis factor-alpha, interleukin-6, and interleukin-8 patterns were observed during and after CPB between the two groups (p < 0.01, p < 0.01, p < 0.05, respectively). All cytokines measured were significantly lower in the heparin-bonded group just after CPB (p < 0.05). There were no differences in duration of intubation, intensive care unit or hospital stay, or postoperative blood loss, but the respiratory index 3 hours after CPB and body weight percent ratio 24 and 48 hours after CPB were significantly reduced in the bonded group (p < 0.05, p < 0.01, p < 0.05, respectively). CONCLUSIONS: Our findings suggest that heparin bonding of the bypass circuits affects early postoperative status and reduces cytokine responses in pediatric cardiac surgery.

Anticoagulants↗

PubMed2000

Moving mesh method for reconstructing some spread sources in the brain.

The purpose of this paper is to propose a new algorithm for the analysis of biomagnetic field data obtained from magnetoencephalography (MEG) measurements. This new method overcomes two major problems faced by the current method of data analysis. The first problem is the need to determine the number of sites of brain activity before calculations can be performed. The second problem is inability of the analysis to provide any information regarding the volume of the brain activity. The new data analysis method, called the Moving Mesh Method (MMM), is capable of analyzing MEG data without the need to determine the number of sources beforehand. In addition, the MMM determines the location of brain activity as a three dimensional volume, instead of as a point source of activity. The MMM uses an iterative method of calculating the position of the sources to achieve greater accuracy, and a regularized g-inverse matrix to stabilize its solution. The feasibility of the MMM was examined by two methods. First, a computer simulation was used to confirm the MMM's capability to analyzing MEG data. In the second experiment, the MMM was applied to analyze somatosensory evoked fields obtained using a new imaging system (Shimadzu Biomagnetic Imaging System, Model-100). From the interpretation of the results, we have concluded that the MMM is a feasible method of biomagnetic data analysis.

Algorithms↗

PubMed2000

Magnetic resonance imaging with gadolinium DTPA enhancement in patients with acute head injury.

Gadolinium-enhanced magnetic resonance (MR) imaging in patients with acute head injury was conducted to study if contrast extravasation was associated with development of hemorrhagic lesions. A series of 60 head-injured patients were admitted to our emergency unit. Computerized tomography (CT) scans and skull x-ray films were taken as rapidly as possible after hospitalization. Injury severity on admission was evaluated using the Glasgow Coma Scale (GCS) score, motor score, and pupillary examination, while overall outcome was assessed with the Glasgow Outcome Scale (GOS) 3 months after injury. Of all patients admitted, MR imaging with gadolinium enhancement was performed in 18 patients who were at high risk of developing hemorrhagic lesion within 6 h after injury. In these patients we investigated whether contrast extravasation was associated with development of hemorrhagic lesions. All 18 patients presented abnormal findings on their admission CT scans. Admission GCS score in those patients who underwent MR imaging with gadolinium enhancement was 13 or more in 12 patients, 9-12 in four patients, and 8 or less in two patients. Fourteen of 18 patients showed contrast extravasation, corresponding with an evolution of lesion size. Nine of 14 patients who demonstrated extravasation of the contrast medium required surgical treatment. The results of the current study suggest that extravasation of contrast medium indicates a continuance of posttraumatic bleeding. Thus, MR imaging with gadolinium enhancement in acutely head-injured patients may constitute a reasonable strategy for predicting the development of hemorrhagic lesions.

Aged↗

PubMed2000

Stent-graft treatment of type B aortic dissection involving the right aortic arch: case report.

A 56-year-old man suffered from type B aortic dissection associated with the right aortic arch and right descending aorta. The patient was successfully treated by implantation of 2 stent-grafts (a 40-mm Z-stent covered with a 37.5-mm woven Dacron graft) and ligation of the dissected left subclavian artery. A postoperative computed tomographic scan revealed thrombosis of the false lumen and a reduction in the descending aortic diameter.

Aortic Dissection↗

PubMed2000

Spinal cord stimulation for cerebral vasospasm as prophylaxis.

Cervical spinal cord stimulation (SCS) was used to increase cerebral blood flow (CBF) in 10 patients with secured cerebral aneurysms in Hunt and Hess grade 3 or 4 and with Fisher group 3 subarachnoid hemorrhage (SAH). The patients underwent preemptive electrical stimulation through a percutaneous lead following aneurysm surgery. All patients also received hypervolemic therapy and nicardipine. Efficacy of the treatment was evaluated using xenon computed tomography and cerebral angiography. The CBF in the distribution of the middle cerebral artery significantly increased following SCS (p < 0.05). Four of 10 patients showed angiographic vasospasm, but none developed severe sequelae of cerebral vasospasm. The overall outcome was good or excellent in seven of the 10 patients. No serious adverse effects due to SCS were observed. Fluid management and calcium antagonist have a beneficial effect on cerebral vasospasm following SAH, but is not tolerated or is ineffective in some patients. SCS as an adjunctive therapy for cerebral vasospasm following SAH may have a favorable effect on outcome.

Aged↗

PubMed2000

[Pulmonary outflow tract reconstruction with autologous tissue during the Ross procedure: right ventricular characteristics in mid-term follow-up].

BACKGROUND: The Ross procedure requires the interposition of prosthetic or homograft extracardiac conduits to establish ventricle-pulmonary artery connection (RV-PA). These materials usually require multiple reoperations because of conduit failure. To avoid the re-replacement of currently available conduits, usage of autologous tissue may be preferable to reconstruct RV-PA connection during the Ross procedure, especially in the pediatric age group. METHOD: Ten patients (mean age 8.7 years, range 2-23) with congenital aortic valve disease underwent the Ross procedure between June, 1996 and July, 1998. To establish RV-PA continuity, autologous aortic wall including aortic valve with a gusset of pericardial tissue was used in six patients, rolled pericardial conduit with fresh pericardial bicuspid valve in three and one direct anastomosis of pulmonary posterior wall onto the right ventricle with a fresh pericardial monocusp valved patch. All patient's postoperative courses were uneventful. All patients were followed up (mean follow-up period: 21.6 +/- 6.6 months) and postoperative right ventricular characteristics, cardio-thoracic ratio (CTR) on chest X-ray and pulmonary valve function were evaluated. RESULTS: Postoperative right ventricular end-diastolic volume, right ventricular ejection fraction and right ventricular end-diastolic pressure did not change significantly (RVEDV: 128 to 113% of normal, RVEF: 56.4 to 51.5%, RVEDP: 5.9 to 10.1 mmHg). Pulmonary regurgitation during follow-up was mild in six patients and moderate in four. However, CTR decreased significantly over time (preop.: 56.5% postop.: 58.5%, late period: 53.4%). CONCLUSION: Our results support the concept of the reconstruction of pulmonary outflow tract without foreign materials during the Ross procedure. Longer follow-up are necessary to define the possible limitation of this technique.

Adult↗

PubMed2000

[Prognostic assessment of the new UICC TNM classification for resected lung cancer].

To evaluated the new UICC TNM classification, we investigated the prognosis of patients who had resection of non-small cell lung cancer. A total of 670 patients with non-small cell lung cancer underwent complete resection and pathologic staging of the disease from 1987 to 1994. The survivals were calculated with Kaplan-Meier methods on the basis of overall deaths, and the survival curves were compared by Logrank test. The 5-year survival rates were 84.6% in stage I A (n = 187), 65.2% in stage I B (n = 177), 41.5% in stage IIA (n = 24), 46.7% in stage IIB (n = 100), 25.6% in stage IIIA (n = 139), 25.8% in stage IIIB and 0 in stage IV. There were significant differences in survival between stage I A and stage I B as well as between stage IIB and stage IIIA. However, there were no significant differences in survival between stage IIA and stage IIB, between stage IIIA and stage IIIB. No significant difference in survival was observed among patients with T1N1M0, T2N1M0 and T3N0M0 (43.9%). In stage IIIB, the patients with pm1 N2 disease (8.9%) had more poorly prognosis than the patients with pm1N0 disease (70.1%) and pm1N1 (38.9%) disease. We concluded that the dividing stage I into A and B categories and placing T3N0M0 in stage II and placing pm2 in stage IV were adequate. In the patients with satellite tumors within the primary lobe of the lung, we think that a new category depended on the N-category is necessary.

Adult↗

PubMed2000

[Combined 5-FU and CDDP in a gastric cancer patient undergoing hemodialysis--pharmacokinetics of 5-FU and CDDP].

The pharmacokinetics of 5-FU and CDDP was examined in a gastric cancer patient receiving regular hemodialysis (HD) for renal failure. The patient received combination chemotherapy of 5-FU and CDDP, then on the day of HD we measured the plasma concentration of 5-FU, total platinum, and non-protein-bound platinum of the patient. In the present case, the 5-FU concentration was kept at an almost even level during HD. Non-protein-bound platinum disappeared after being maintained in blood for a certain time when HD was started 30 minutes after the end of CDDP administration. From these findings, we conclude that combined 5-FU and low-dose CDDP therapy should be done by decreasing the dose of 5-FU, administrating CDDP only on the day the patient undergoes HD, and starting HD 30 minutes after the end of CDDP administration.

Adult↗

PubMed1999

High incidence of synchronous cancer of the oral cavity and the upper gastrointestinal tract.

A high incidence of synchronous esophageal or gastric carcinoma in preoperative patients with carcinoma of the oral cavity was reported. Esophageal carcinoma was found in seven out of 56 patients (12.5%) and gastric cancer in five patients (8.9%) by videoendoscopy aided with lugol staining in the esophagus and indigocarmine solution in the stomach, although all patients were completely asymptomatic for these lesions. All patients were male, regular drinkers and heavy smokers. The depth of invasion of such tumors was limited to either mucosa or submucosa. Those esophageal and gastric lesions beside the primary oral cancers were positive for p53 protein by immunohistochemistry. Careful preoperative evaluation of not only the esophagus but also the stomach should be a routine procedure in patients with carcinoma of the oral cavity.

Aged↗

PubMed1999

Superior biocompatibility of heparin-bonded circuits in pediatric cardiopulmonary bypass.

BACKGROUND: Heparin bonding of pediatric cardiopulmonary bypass circuits may decrease activation of blood compartments as inflammatory responses. We studied the biocompatibility of heparin-bonded circuits in infant cardiac surgery. METHODS: Twenty-four infants undergoing elective cardiac surgery were randomly assigned to either a nonheparin-bonded control circuit (n = 12) or a fully heparin-bonded circuit (n = 12) including membrane oxygenator, reservoir, and all tubing. Blood samples were used to identify differences in complement activation and cytokine release between groups during and after cardiopulmonary bypass. The postbypass oxygenation index was also compared. RESULTS: The C3 activation product in the heparin-bonded group was significantly lower during (p < 0.01) and just after (p < 0.05) cardiopulmonary bypass. No statistically significant difference in C4 activation products was observed. Lower interleukin-6 and tumor necrosis factor-alpha were found immediately after cardiopulmonary bypass (p < 0.05) and a higher mean postbypass oxygenation index was also seen (p < 0.05) in the heparin-bonded group. CONCLUSION: We found that a heparin-bonded cardiopulmonary bypass circuit reduced inflammatory response and improved oxygenation in pediatric cardiac surgery. These results suggest that the superior biocompatibility of the bonded circuit may reduce pulmonary complications.

Cardiac Surgical Procedures↗

PubMed1999

Time course of endothelin-1 and adrenomedullin after the Fontan procedure.

BACKGROUND: The endothelium-derived vasoconstrictor endothelin (ET)-1 might contribute to the physiology of blood flow regulation and play a role in cardiovascular disease. Adrenomedullin (AM) is a potent vasodilator peptide that has major effects on cardiovascular function and has multiple biologic effects involved in cardiovascular homeostasis. Although pulmonary vascular resistance is known to be one of the most important factors to determine the indications for a Fontan procedure, the time course of the plasma cytokine before and after the Fontan procedure is not known. METHODS: Sixteen patients were divided into two groups, 8 patients (1 to 14 years) who had the Fontan procedure (atriopulmonary connection) and 8 age-matched controls who had biventricular repair with normal central venous pressure. Plasma ET-1 and adrenomedullin levels were measured in both groups immediately before cardiopulmonary bypass, immediately after cardiopulmonary bypass, and 6 and 24 hours after cardiopulmonary bypass. A thermodilution catheter was inserted during the operation, and mean pulmonary arterial pressure, pulmonary wedge pressure, and cardiac output were measured, and pulmonary vascular resistance was calculated at the same time points. Correlation between the plasma ET-1 levels and pulmonary vascular resistance data were obtained in the Fontan group. RESULTS: Plasma ET-1 levels in the Fontan group were elevated after operation and were higher than the control group at 6 and 24 hours after cardiopulmonary bypass. Plasma adrenomedullin in the Fontan group was lower than in the control group at 6 and 24 hours after cardiopulmonary bypass. A significant positive correlation was obtained between the plasma ET-1 and pulmonary vascular resistance data (r = 0.475). CONCLUSIONS: Imbalance between increased ET-1 and relatively decreased adrenomedullin after cardiopulmonary bypass in the Fontan procedure could contribute to dominant effects of ET-1, which might induce vasoconstriction after the Fontan procedure. ET-1 might play an important role in maintaining vasoconstriction after the Fontan procedure.

Adolescent↗

PubMed1999

A new method for magnetoencephalography: a three-dimensional magnetometer-spatial filter system.

A novel three-dimensional magnetometer-spatial filter system was developed to study human brain activity with high spatiotemporal resolution. The system combines the high temporal resolution of magnetoencephalography with the high spatial resolution achieved by using three-dimensional magnetometers and spatial filters to measure the direction and intensity of magnetic fields generated during brain activity. Simulation and phantom studies indicate that the system is capable of mapping current sources of magnetic fields with a spatial resolution comparable to that of any other brain functional imaging technique while maintaining millisecond temporal resolution. Application of this system to the human brain resolved magnetoencephalographic responses evoked by motion stimuli on a millisecond scale into responses occurring in visual cortical areas V1, V2/3 and V5. It also revealed signals related to contextual modulation in V1 and V2/3. This system provides a new way of studying the dynamics of human brain function.

Brain↗

PubMed1999

Thiomenthol derivatives as novel percutaneous absorption enhancers.

Thiomenthol derivatives were synthesized and their promoting activity on the percutaneous absorption of ketoprofen from hydrogels was evaluated in rats. The apparent penetration rate (Rp) of ketoprofen absorbed from the hydrogel was estimated by the pharmacokinetic model derived under the assumption of a constant penetration rate through the skin after a lag time. As an index of promoting activity of thiomenthol derivatives, an enhancement factor (Ef) was defined as the ratio of the Rp value with enhancer to the value obtained with the control not containing enhancer. Skin irritancy evoked by these derivatives was investigated microscopically by using a cross-section of the excised skin onto which ketoprofen hydrogel was applied. Total irritation score (TIS) was estimated by summation of each irritation score in several parts of the skin. The physicochemical parameters of thiomenthol derivatives such as a partition coefficient (log P) and a steric energy were calculated and the quantitative relationships between these parameters and the Ef values or TIS values were investigated on the basis of multiple regression analysis. As a result, a parabolic relationship between log P and Ef was noted. A similar relationship was also observed in the case of TIS.

Administration, Cutaneous↗

PubMed1999

Clinical application of magnetoencephalography in a patient with corticobasal degeneration.

Previous neuroimaging studies in corticobasal degeneration (CBD), such as MRI and positron emission tomography, showed lateralized cortical atrophy and a decrease in cortical oxygen metabolism, respectively. The advantage of magnetoencephalography in the research of the auditory system is that activity of both hemispheres can be detected separately. Auditory-evoked magnetic fields (AEFs) were then applied to a patient with corticobasal degeneration. The strength of N100m equivalent current dipoles (ECD) in left hemisphere was extremely smaller (20 nAm) than that in right hemisphere (48 nAm). This results implies that CBD patient might have a decrease in the number of neurons in the primary auditory cortex. This study suggests that AEF measurement is one of the most powerful tools for detecting latent impairment of auditory function in patients with corticobasal degeneration.

Aged↗

PubMed1999

[Noonan syndrome associated with atrial septal defect, pulmonary stenosis, and completely unroofed coronary sinus without LSVC: a case report].

An eight-year-old boy, Noonan syndrome associated with ASD and PS, was referred to our department for surgical repair. During operation, the coronary sinus ostium was not found. Farther more exploration revealed completely unroofed coronary sinus without LSVC. The large ASD (confluent with coronary sinus ASD) was closed with a ePTFE patch. The pulmonary valve was thickened moderately and each commissure was adhesive, but not dysplastic. PS was released with commissurotomy and subpulmonary muscle resection. The postoperative course was uneventful and the patient discharged at 14 postoperative day. At present, he has been followed at outpatient without PS and any sign and symptom of myocardial hypertrophy.

Cardiac Surgical Procedures↗

PubMed1999

[A case of Bentall's operation for an 11-year-old patient with Marfan syndrome].

An 11-year-old girl who was diagnosed to have Marfan syndrome in her infancy, visited us with complaints of easy fatigability and chest discomfort. She was pointed out to have acute development of annuloaortic ectasia with severe aortic regurgitation and mild mitral regurgitation. She underwent replacement of the ascending aorta and aortic valve using composite graft with prosthetic valve (Bentall's operation) and circular annuloplasty of the mitral valve. Bentall's operation for infants and children is remarkably rare because in this generation, acute development of aortic dilatation leading rupture and dissection is quite infrequent while main death is caused by mitral regurgitation.

Aorta↗