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Biomedical subjects

Y Sakakibara

Publications and source records attributed to Y Sakakibara.

At least 19 recordsLinked to original sources

Neuroprotective effect of 1-aminocyclopropanecarboxylic acid in a rabbit spinal ischemia model.

BACKGROUND: Postoperative paraplegia remains a serious complication after repair of a thoracoabdominal aortic aneurysm. The release of the excitatory neurotransmitter glutamate might be responsible for ischemic neuronal damage. We investigated the effect of 1-Aminocyclopropanecarboxylic acid (ACPC) on the prevention of paraplegia in a rabbit model of spinal cord ischemia. METHODS: The infrarenal abdominal aorta was clamped in eighteen rabbits. Saline (group A), 20 mg/kg of ACPC (group B), or 10 mg/kg of ACPC (group C), was injected into the clamped aorta. The animals were neurologically evaluated by Tarlov's score. The spinal cord was obtained for histopathologic examination, including hematoxylin and eosin staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining method. RESULTS: Postoperative complete paraplegia with marked neuronal necrosis appeared in group A animals. Four of the six group C animals showed intact neurological function. Scattered TUNEL positive neurons were seen within areas containing necrotic cells in sections from paraplegic animals in group A. CONCLUSIONS: ACPC can prevent spinal cord injury in a rabbit model of spinal cord ischemia.

Amino Acids, Cyclic↗

[Asplenia syndrome with total anomalous pulmonary venous connection].

Three patients of asplenia syndrome with total anomalous pulmonary venous connection (TAPVC) were reported. Case 1 with exceeding pulmonary blood flow, underwent TAPVC repair and pulmonary artery banding as a first palliation before bi-directional Glenn shunt. Case 2 did not require any surgery to control the pulmonary blood flow before the simultaneous procedure of TAPVC repair and bi-directional Glenn shunt. Case 3 with decreased pulmonary blood flow underwent a complicated course with 3 times of Blalock-Taussig shunts and the repair of TAPVC to prepare for bi-directional Glenn shunt. Simultaneous repair of TAPVC with the procedure which aimed to control the pulmonary blood flow at the first palliation surgery will simplify the control of pulmonary blood flow and prepare good condition of the lung for the Fontan operation in the future.

Abnormalities, Multiple↗

[Delayed onset malignant hyperthermia after a closure of ventricular septal defect].

An 18 month-old girl was diagnosed as ventricular septal defect (VSD) with mild aortic valve prolapse. She underwent a closure of VSD. Intra-and early postoperative course was uneventful. However, 20 hours after surgery, sudden bradycardia led to cardiac arrest and strong muscle rigidity was seen. Hyperkalemia and metabolic acidosis rapidly progressed and resuscitation was failed. Extracorporeal life support and continuous hemodialysis were initiated, but the patient died with multiple organ failure on 5th postoperative day. Her clinical course supported the diagnosis of delayed onset malignant hyperthermia. Histopathological findings of muscle biopsy were consistent with rhabdomyolysis, and immunopathological stains demonstrated changes as in a Duchenne type muscular dystrophy carrier. Delayed onset malignant hyperthermia is an extremely rare complication of general anesthesia. We should be aware of this lethal condition, which occurs with a certain time lag after surgery, especially when the patient has possible background of myopathy.

Female↗

[Cor triatriatum diagnosed in adulthood; report of a case].

Cor triatriatum is a rare congenital cardiac anomaly especially in adulthood. A 68-year-old female was diagnosed as a cor triatriatum classified to Lucas-Schmidt IA, severe degree of mitral regurgitation and atrial fibrillation. Resection of the abnormal diaphragm in the left atrium and miral valve replacement were performed. Although the reason of sudden death of this patient after discharge is unknown, surgical intervention for atrial fibrillation should have performed to prevent a thromboembolism in such cases.

Aged↗

Development of a high-efficiency H2 feeder for bioremediation.

An electrochemical dissolved hydrogen feeder equipped with a multi-cathode system and a high-rate recirculation pump was developed in order to examine its feasibility for bioremediation. Results showed that the feeding efficiency was remarkably higher than that in former studies. The reason for the enhanced hydrogen dissolution rate was thought to be due to the large cathode area by applying multiple granular activated carbon electrodes resulting in low current density. Two mass balance equations were formulated and applied to analyze the performance of the apparatus theoretically. The hydrogen dissolution rate calculated from the equations was in fairly good agreement with observed results. It was suggested that the electrochemical H2 feeder would be a competitive alternative as a hydrogen feeding method for bioremediation.

Bacteria↗

Orbital emphysema following nose blowing as a sequel of a snowboard related head injury.

A case of orbital emphysema as a sequel of a snowboard related head injury is reported. It is believed that a fracture of the medial orbital wall was caused by the increased intraorbital pressure when the patient hit his forehead on the snowy ground, allowing air to enter the orbit when he blew his nose. Wearing goggles may prevent this type of sports related injury.

Adult↗

Effect of left ventricular assist device on circulatory autonomic nervous activity.

PURPOSE: For evaluation of the autonomic nervous system (ANS) activity of patients with mechanical circulatory support including LVAD, IABP and PCPS, arterial pressure variability (APV) was examined. APV is the power density values of pressure signals. High frequency (0.15 to 0.4 Hz) and low frequency (0.04 to 0.15 Hz) components of APV are regarded as a function of the autonomic nervous system. METHODS: Arterial pressure signals were acquired every 2 hours at 100 Hz for 6 minutes. Power spectral analysis was carried out, and APV was observed in 18 patients with IABP and/or PCPS. APV was also observed in 3 patients with LVADs (Xemex, Zeon Medical, Japan) before their discharge from ICU for transfer to another hospital for cardiac transplantation. RESULTS: Although the value gradually increased in 18 patients with IABP and/or PCPS, sustained low values of LFAnorm of APV in 6 patients were related to prolonged mechanical support, and 4 patients among them died consequently. The normalized power spectral component with low frequency (LFAnorm) was maintained at relatively high values in 3 patients with LVADs. CONCLUSION: The study results suggest that power spectral analysis of systemic arterial pressure offers a reasonable means for the evaluation of the severity of patient cardiovascular condition and for the prediction of clinical outcome. It also suggested that LVAD support exerts a favorable effect on ANS in patients with severe heart failure before cardiac transplantation.

Adult↗

[Leaflet extension technique in a congenital aortic valve regurgitation].

A 17-year-old boy who was diagnosed as congenital aortic valve regurgitation underwent the leaflet extension technique in 3 aortic leaflets using glutaraldehyde-preserved autologous pericardium. Intraoperative transesophageal echocardiography and postoperative cardiac catheter revealed grade I regurgitation and the patient has been doing well for more than 4 months after the surgery. The leaflet extension technique is considered to be an acceptable surgical treatment for aortic valve disease especially in young patients to whom valve replacement or Ross procedure might not be suitable. A careful long-term follow-up will be necessary to evaluate the durability of the leaflet extension technique with autologous pericardium.

Adolescent↗

[Oral sildenafil citrate as an effective alternate in the treatment of postoperative pulmonary hypertensive crisis after congenital heart surgery].

A five-month-old girl of Down syndrome underwent a corrective surgery for complete atrioventricular septal defect. Her postoperative course was complicated with pulmonary hypertensive (PH) crises despite nitroglycerin (NTG) infusion and inhaled nitric oxide (NO). Sildenafil citrate, a phosphodiesterase 5 inhibitor, was administered through a nasogastric tube at a starting dose of 0.3 mg/kg by stepwise increment to the maximum dose of 2 mg/kg 4 hourly. Sildenafil citrate dramatically lowered pulmonary arterial pressure and the patient was weaned from NTG and NO without PH crisis. There was no side effect after sildenafil citrate administration. Oral sildenafil citrate is a safe and potent adjunct to the existing therapies for postoperative PH in infants after open heart surgery.

Administration, Inhalation↗

[Management of mediastinitis after pediatric cardiac surgery with continuous closed irrigation method].

Two cases are presented as a successful management for mediastinitis with the continuous closed irrigation method after pediatric cardiac surgery. The continuous closed irrigation method has significant advantages over conventional open irrigation method or muscle flap in pediatric cases, because the system is simple to handle and easy to wash out any infectious tissue debris without additional invasive intervention. However, adequate duration of the irrigation and subsequent antibiotic regimen is still unclear. We conclude that the continuous closed irrigation method is an effective management which is applicable to most of mediastinitis cases after pediatric cardiac surgery.

Blood Vessel Prosthesis Implantation↗

A bio-electrochemical reactor coupled with adsorber for the removal of nitrate and inhibitory pesticide.

In this study, the treatment characteristics of nitrate and toxic pesticide by a combined bioelectrochemical reactor (BER)/adsorption process was investigated. Experimental results showed that the disappearance of NO3- in BER was in accordance with the applied current. NO2- was not detected in the effluent, but the production of N2O was increased with increasing IPT loading. In the presence of IPT, up to 30% of the nitrate nitrogen consumed was converted to N2O, while more than 95% converted to N2 in the absence of IPT. In adsorption column, IPT was efficiently removed onto either granular activated carbon or silicone resin so as to meet the guideline value (40 microg/I) and to reduce the N2O accumulation. A simplified kinetic model that considers the sequential reduction of nitrate and inhibition of the N2O reduction step by pesticide as well as Langmuir adsorption isotherm was developed and used to evaluate the process performance. Theoretically predicted effluent concentrations were in good agreement with the observed results for nitrate, nitrite, N2O, N2 and IPT. It was considered that high removal performance of nitrate and pesticide by the combined process is attributable to high affinity of adsorbates for IPT in comparison with relatively large inhibition constant (Ki).

Adsorption↗

Phosphate removal and recovery by a novel electrolytic process.

The possibility of removing and recovering phosphate from wastewater by a novel electrolytic process was investigated experimentally. In the process, ion electrodes are immersed in synthetic wastewater and direct current (DC) is applied to coagulate phosphate on the surface of the anode. Experimental results demonstrated that at electric current densities ranged from 0.001 to 0.1 mA/cm2, phosphate was removed and recovered as phosphate-rich aggregates formed on the anode surface. Decreases in phosphate concentration at bulk liquid were in fairly good agreement with the amounts of phosphate in the aggregates. Moreover, the removal rate of phosphate was increased with increasing electric current. In addition, as heavy metal anions such as Cu2+ deposit on the counter electrode (cathode), it was thought that relatively pure phosphate could be obtained by the present process.

Conservation of Natural Resources↗

Initial effects of the left ventricular repair by plication may not last long in a rat ischemic cardiomyopathy model.

BACKGROUND: Long term effects of left ventricle (LV) repair surgery (LVR) for ischemic cardiomyopathy are not well understood. METHODS AND RESULTS: Sixty-nine rats developed ischemic cardiomyopathy with large akinetic LV area 4 weeks after the left anterior descending artery was ligated. In a second surgery 4 weeks later, 33 rats underwent LVR by plication of the akinetic LV area (LVR group), and 36 underwent rethoracotomy alone (sham group). No medication was used in either group. All rats survived the second surgery. LV end-diastolic dimension as measured by echocardiography, LV fractional shortening, and the maximal end-systolic pressure-volume relationship (E(max)) as calculated from the data by catheter-tipped manometer and echocardiography improved in the LVR group after the second surgery, but LV end-diastolic dimension and E(max) gradually deteriorated as time passed. LV end-diastolic pressure improved 1 week after LVR but rose significantly 4 weeks after LVR. Brain natriuretic peptide mRNA was lower in the LVR group than in the sham group 1 week after LVR but not 4 weeks postoperatively. CONCLUSIONS: Initial improvement in LV function and neurohormonal status after LVR did not last for 4 weeks in this rat model when untreated medically. The mechanism of deterioration should be elucidated to improve long-term results of LVR.

Animals↗

Sulfation of flavonoids and other phenolic dietary compounds by the human cytosolic sulfotransferases.

The protective effects of diet, especially soya products, tea, and many fruits, against a variety of human cancers, as suggested by epidemiological studies, has focused attention on flavonoids, isoflavonoids, and other phenolic dietary compounds as chemoprotectants. Among the mechanisms suggested for their chemoprotective action, their ability to inhibit the bioactivation of carcinogens by the human cytosolic sulfotransferases (STs) and the direct effects of their sulfoconjugates are being increasingly studied. We report here a systematic study on the sulfation of representative flavonoids, isoflavonoids, anti-oxidants, and other phenolic dietary compounds by all ten known human cytosolic STs. All ten recombinant human cytosolic STs were prepared in a pure form and tested for their sulfating activities with a variety of these compounds. P-form (SULT1A1) phenol ST (PST) showed high sulfating activity with most of these compounds. M-form (SULT1A3) PST showed high activity with the flavonoids but not with the isoflavonoids. SULT1C ST #2 showed high activity with the isoflavonoids and also sulfated most of the other compounds. Possible relevance of these results to the chemoprotective effects of these dietary compounds is discussed.

Antioxidants↗

Characterization of three members of murine alpha1,2-fucosyltransferases: change in the expression of the Se gene in the intestine of mice after administration of microbes.

We cloned three members of a GDP-fucose:beta-galactoside alpha1,2-fucosyltransferase (alpha1,2-fucosyltransferase) family, MFUT-I, -II, and -III, from a cDNA of murine small intestine, and determined their enzymatic properties after transfection of the genes into COS-7 cells, and their expression in murine tissues by Northern blotting. MFUT-I, -II, and -III exhibited sequence homology with the human H (78.4%), Se (79.0%), and Sec1 (74.9%) gene products, respectively. COS-7 cells transfected with MFUT-I and -II exhibited alpha1,2-fucosyltransferase activity and the best acceptor substrate for both gene products was GA1 to yield a fucosyl GA1 structure, but no activity was detected in COS-7 cells with MFUT-III. MFUT-II yielded a 3.5-kb mRNA transcript in several tissues, whereas MFUT-I and -III were predominantly expressed in epididymis and testis, respectively. The administration of microbes into germ-free mice resulted in a rapid increase of the MFUT-II gene (Se gene) for the synthesis of fucosyl GA1 in the intestine.

Amino Acid Sequence↗

Surgery for acute type A aortic dissection using retrograde cerebral perfusion.

OBJECTIVE: We reviewed the surgical management of acute type A aortic dissection between 1989 and 1998. METHODS: Subjects were 28 consecutive patients (mean age: 61.8 +/- 10.7 years) with acute type A aortic dissection were studied. The mean duration between aortic dissection onset and surgery was 17.5 +/- 17.0 hours. In surgery, aortic pathology and flow patterns in dissected aortic channels were evaluated using transesophageal and epiaortic echo. Simple, safe combination of profound hypothermic circulatory arrest with retrograde cerebral perfusion and open aortic anastomosis was used for brain protection. Hypothermic circulatory arrest was 46.9 +/- 24.8 minutes. Aortic repair consisted in ascending aortic replacement in 5 patients, with hemiarch repair in 17, and total arch repair in 6. Intimal tears were resected in all but 2 patients. Concomitantly resuspension of the aortic valve was done in 9 and aortic root replacement in 2. RESULTS: No operative (30-day) deaths occurred, although 2 died from unrelated hepatic failure during hospitalization or late-stage pancreatic cancer in the late stage. In cerebral sequellae, 1 patient suffered a stroke and 2 patients developed temporary neurologic dysfunction. CONCLUSION: Our experience demonstrated that the simplified conjunction of hypothermic circulatory arrest with retrograde cerebral perfusion and open aortic anastomosis, associated with real-time assessment by transesophageal and epiaortic echo, is safe and useful during emergency aortic repair for acute type A aortic dissection.

Acute Disease↗