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Biomedical subjects

Y Shimazaki

Publications and source records attributed to Y Shimazaki.

At least 73 records · Page 4Linked to original sources
PubMed1998

Ruptured aneurysm of the ductus diverticulum into the pulmonary artery in a man: a successful repair.

Aneurysm of the ductus diverticulum in the adult is rare and its rupture is fatal. A 75-year-old man presented with congestive heart failure that suddenly occurred with a continuous murmur. Angiography showed a left-to-right shunt through a large thrombosed aneurysm of the ductus diverticulum (6 cm), and the pulmonary-to-systemic flow ratio was 2.6. Patch closure of the orifice (3x4 cm) of the aneurysm and repair of the perforated pulmonary artery were done emergently under hypothermic cardiopulmonary bypass with selective cerebral perfusion. He recovered uneventfully. Early recognition and early intervention should be indicated in this otherwise fatal condition.

Aged↗
PubMed1998

Aortic valve replacement through the transected aorta in a patient with aortic stenosis and a calcified ascending aorta.

This report describes a surgical approach of aortic valve replacement in a patient with a calcified ascending aorta, calcified aortic valve stenosis and coronary artery disease. The aortic valve was replaced with a 19 mm St. Jude Medical prosthetic valve through the transected aorta while the distal ascending aorta was cross-clamped at a narrow but not calcified band approximately 4.5 cm distal to the aortic anulus. These procedures were successfully done and no neurological deficit was found after surgery. The aortic valve replacement through the transected aorta may be one of the alternatives in selected patients with porcelain aortas and calcified aortic valves.

Aged↗
PubMed1998

Bentall operation, total aortic replacement and mitral valve replacement for a young adult with Marfan syndrome: a case of three-staged operation.

In Marfan syndrome, the most common cardiovascular abnormalities are dilatation of the aorta and aortic valve regurgitation in adult patients. Mitral valve dysfunction is the most common cause of morbidity and mortality in infants and children with Marfan syndrome, and is not frequently operated on in adult Marfan patients who undergo surgery for diseases of the aortic root and total aorta. This report describes a successfully three-staged operation for a 24 year-old man with Marfan syndrome who underwent an emergent Bentall operation and aortic arch replacement, total aortic replacement and mitral valve replacement over 2 years. Mitral valve regurgitation was mild but increased after the second operation. The graft was tightly adhesive and invasive to the sternum. Endoscopic view was helpful to avoid graft damage at resternotomy. The postoperative course was uneventful in each operation. Microscopic examination of the mitral valve leaflets showed abnormal increase of mucopolysaccharides, and disruption and fragmentation of elastic fibers.

Adult↗
PubMed1997

Regional tissue blood flow and pH in the brain during deep hypothermic retrograde brain perfusion.

Deep hypothermic retrograde brain perfusion is used to protect the brain during aortic arch operations. However, all experiments have failed to demonstrate retrograde blood flow in the brain tissue. We developed an experimental model of sagittal sinus and simultaneous superior vena cava perfusion. Brain tissue blood flow was mapped with colored microspheres during deep hypothermic retrograde brain perfusion in 9 dogs. Regional brain pH was mapped photometrically using neutral red as a pH-indicating dye after 90 min of retrograde brain perfusion in 28 dogs and after 60 min of circulatory arrest in 8 dogs. Cerebral surface blood flow was also measured during retrograde brain perfusion. They were analyzed as functions of driving pressure between sagittal sinus and aorta. Total brain blood flow (ml/min/100 g) was 1.4 +/- 1.3, 3.8 +/- 2.6, and 4.6 +/- 2.6 when the driving pressure was 15, 25, and 35 mmHg, respectively (P < 0.05, 15 mmHg vs 25 mmHg). Regional cerebral blood flow (ml/min/100 g) with a driving pressure of 25 mmHg was 12.1 +/- 9.4, 7.0 +/- 5.6, 4.4 +/- 2.8, and 2.2 +/- 1.4 in the frontal cortex, anterior, mid, and posterior cerebrum, respectively. Cerebral cortex pH was 6.86 +/- 0.23, 7.15 +/- 0.18, and 6.46 +/- 0.13 after 90 min of retrograde brain perfusion with driving pressure of less than 20 mmHg, after that of above 20 mmHg, and after 60 min of circulatory arrest, respectively. Brain tissue pH, blood flows measured with microspheres, and laser flowmetry were highest when driving pressure was between 25 and 35 mmHg. We conclude that retrograde brain perfusion may provide maximum brain protection with driving pressure of 25 to 35 mmHg.

Animals↗
PubMed1997

Semicircular suture annuloplasty for mitral regurgitation: appraisal of the Paneth-Burr method.

BACKGROUND AND AIMS OF THE STUDY: Mitral annuloplasty has long been considered as the basic procedure for mitral regurgitation (MR). However, it is increasingly advisable to avoid foreign material and to use a method that provides greater adjustment for control of annular size. In this study, the semicircular suture annuloplasty (Paneth-Burr method) was evaluated for its efficacy and durability; the optimum size of the mitral annulus was also assessed. METHODS: The Paneth-Burr method was modified using Gore-Tex suture, a crossing suture technique, and obturator for temporary annulus size adjustment. Between 1992 and 1994, 21 patients with an average age of 45 years (range: 8 months to 67 years) underwent such annuloplasty combined with various valvuloplasties and chordal reconstruction. The etiologies were degenerative in 11 patients, congenital in five, ischemic in three and endocarditis in two. RESULTS: Mean MR grades (0-4) decreased from 3.3 +/- 0.6 to 0.2 +/- 0.4 after surgery. At an average 24 months follow up (range: 12 to 41 months), 16 patients showed no increase in MR, but five showed increased MR grades (all grade 3 or less: three grade 3 and two grade 2). Only one patient with ischemic MR required reoperation. Patients with increased MR grade during follow up had a larger intraoperative annular size (> 90% of normal), while those with < 90% of normal mitral annular size showed no increase in MR beyond grade 2, except one with ischemic etiology. CONCLUSIONS: A measured semicircular suture annuloplasty appears to be useful for MR, with acceptable efficacy and durability. In addition, the annular size to be adjusted at surgery is proposed to be < or = 90% of normal mitral annular diameter.

Adolescent↗
PubMed1997

[A case of idiopathic spinal epidural hematoma with a fructuation of the symptoms].

We reported a 9-year-old girl with idiopathic spinal epidural hematoma. She complained of her back and neck pain only during night for a few days, followed by days with no symptoms (a few days remission of her symptoms). This episode repeated, and she was suspected to have a psychogenic reaction. However, 28 days later after the first symptoms appeared, paralysis of lower extremities, anesthesia and urinary bladder dysfunction (neurogenic bladder) appeared. Spinal MRI showed a spinal epidural hematoma at the C 5-Th 2 level. An emergency operation of laminectomy and evacuation of the hematoma was done, and she has recovered gradually. We diagnosed her as having idiopathic spinal epidural hematoma. Excerbations of symptoms during nights were thought to be due to an elevation of venous pressure by lying, and transient remissions were due to intermittent small hemorrhages.

Child↗
PubMed1997

[A Rastelli operation with a reconstruction of the central pulmonary artery for a pulmonary atresia with an absent left pulmonary artery].

A Rastelli procedure was successfully performed on a 6-year-old girl with an absence of the intrapericardial pulmonary artery and the left pulmonary artery (PA), following a right B-T shunt. The central PA was reconstructed with an 18 mm diameter xenopericardial roll behind the ascending aorta and the superior vena cava. After intracardial repair, the Rastelli operation was performed using an 18 mm diameter composite graft which consisted of a valved xenopericardial roll and a knitted Dacron graft. Since the size of the right PA was large enough to undergo this surgical procedure (the preoperative right PA index was 300 mm2/m2), the postoperative peak systolic pressure ratio of the right ventricle to the left ventricle declined from 1.0 to 0.64. Although the patient showed slight signs of right ventricular failure on the operative day, the postoperative course was uneventful.

Bioprosthesis↗
PubMed1997

[Simultaneous repair for funnel chest and intracardiac lesions in two pediatric patients].

Two successful cases underwent simultaneous repair for funnel chest using sternal turnover with rectus abdominal flap and intracardiac lesions were reported. A 7-year-old female (case 1) was diagnosed with funnel chest and annulo-aortic ectasia due to Marfan's syndrome. Second patient was a 12-year-old male (case 2) with funnel chest and ventricular septal defect (VSD). Both patients underwent sternal turnover and intracardiac repair (case 1: Bentall's operation, case 2: patch closure of VSD), simultaneously. Removing the cost-sterno complex before cardiac operation allowed an excellent surgical exposure. Bleeding was minimum, especially no homologous blood transfusion was needed in case 2. Simultaneous surgery consisted of intracardiac repair and sternal turnover is recommended even for pediatric patients.

Aortic Valve Insufficiency↗
PubMed1996

Phosphorylation of 25-kDa synaptosome-associated protein. Possible involvement in protein kinase C-mediated regulation of neurotransmitter release.

Protein kinase C-mediated phosphorylation of a 25-kDa synaptosome-associated protein (SNAP-25) was examined in living PC12 cells. Phorbol 12-myristate 13-acetate treatment enhanced high potassium-induced [3H]-norepinephrine release, and a 28-kDa protein recognized by an anti-SNAP-25 antibody was phosphorylated on Ser residues. The molecular size of the phosphorylated band decreased slightly following treatment with Clostridium botulinum type A neurotoxin, whereas the band disappeared after treatment with botulinum type E neurotoxin, indicating that the 28-kDa protein was SNAP-25. A phosphorylation is likely to occur at Ser187, as this is the only Ser residue located between the cleavage sites of botulinum type A and E neurotoxins. SNAP-25 of PC12 cells was phosphorylated by purified protein kinase C in vitro, and the amount of syntaxin co-immunoprecipitated with SNAP-25 was decreased by phosphorylation. These results suggest that the phosphorylation of SNAP-25 may be involved in protein kinase C-mediated regulation of catecholamine release from PC12 cells.

Animals↗
PubMed1996

Pericardial mesothelioma presenting as left atrial thrombus in a patient with mitral stenosis.

Primary pericardial mesothelioma is rare and remains a diagnostic and therapeutic challenge. Pericardial mesothelioma usually occurs independently of intracardiac lesions and infiltrates adjacent tissues superficially. An extremely rare case of malignant pericardial mesothelioma complicated by prior mitral valve surgery is reported. The tumour invaded the left atrium and mimicked a thrombus.

Diagnosis, Differential↗
PubMed1996

Attenuation of cardiopulmonary bypass-derived inflammatory reactions reduces myocardial reperfusion injury in cardiac operations.

In cardiac operations endopeptidase (protease) inhibitor may be beneficial in reducing myocardial injury when administered in the cardiopulmonary bypass prime. Nafamostat mesilate was evaluated in 20 patients who underwent coronary artery bypass grafting. The patients were divided into a control group (n = 10) and a nafamostat group (n = 10). Nafamostat (2 mg/kg per hour) was continuously given during cardiopulmonary bypass in the nafamostat group. The age, number of grafts, cardiopulmonary bypass time, and aortic crossclamp time were similar between groups. In the control group, neither tumor necrosis factor-alpha nor interleukin-1 levels showed any significant change during cardiopulmonary bypass, whereas interleukin-6 and interleukin-8 levels, percent expression of adhesion molecule (CD18) on neutrophils, and CH50 assay results increased significantly during cardiopulmonary bypass. As compared with the control group, the nafamostat group showed significantly lower levels of interleukin-6 (123 +/- 57 versus 40 +/- 22 pg/ml, respectively) and interleukin-8 (96 +/- 13 versus 66 +/- 14 pg/ml, respectively). The nafamostat group showed a significantly lower difference of CH50 assay results and malondialdehyde levels between coronary sinus blood and arterial blood and peak values of creatine kinase MB (43 +/- 12 IU/L versus 19 +/- 6 IU/L) during the postoperative course compared with findings in the control group. These results demonstrated that inflammatory reactions induced by cardiopulmonary bypass had adverse effects on myocardial recovery after aortic crossclamping and that nafamostat mesilate given during cardiopulmonary bypass appeared to reduce myocardial reperfusion injury by attenuating such inflammatory reactions. Attenuation of inflammatory reactions of cardiopulmonary bypass should be considered in the strategy of myocardial protection.

Benzamidines↗
PubMed1996

Effect of new macrolide roxithromycin upon nasal polyps associated with chronic sinusitis.

We often observe shrinkage of nasal polyps with low-dose long-term macrolide treatment, which was recently developed in Japan for the treatment of intractable chronic sinusitis. In order to assess the efficacy of this treatment for nasal polyps, we administered the new macrolide roxithromycin (RXM) (1 tablet: 150 mg a day) for at least 8 weeks to 20 patients with nasal polyps associated with chronic sinusitis. It was competent in controlling nasal polyp with the overall incidence of improvement being 52%. The combination of RXM with azelastine (1 mg twice/day), an inhibitor of mediator release, was examined in 20 other patients. It augmented the rate of improvement to 68%, but the increase was not significant. The incidence of improvement increased with time after the start of medication in both groups. Smaller polyps were more likely to decrease in size, but some larger polyps also markedly decreased in size. Associated allergic conditions and the extent of eosinophilic infiltration had no relation to the treatment result. We speculate that the mechanism of effectiveness of RXM is through its suppressive potency in cytokine production from inflammatory cells.

Adult↗
PubMed1996

[Giant isolated extracadiac unruptured aneurysm of the right coronary sinus of valsalva--a case report].

A giant isolated extracardiac unruptured aneurysm of the right coronary sinus of Valsalva was detected incidentally in a 24-year-old man with clinical findings of Ehlers-Danlos syndrome. The right coronary artery was occluded at its ostial resion. Surgical correction was performed by obliterating the orifice of the aneurysm with a Dacron patch. Microscopic examination of the diseased aortic wall revealed absence of medial elastic fibers. Collective review of 19 reported similar cases revealed that reports concerning unruptured, isolated giant sinus of Valsalva aneurysm were rare, especially in young patients, and that the aneurysm of this patient was the largest.

Adult↗
PubMed1996

[Repair of total anomalous pulmonary venous return using an ultra-short acting beta blockade (esmolol)--case reports].

In 2 infants with asplenic syndrome associated with total anomalous pulmonary venous return (TAPVR), a repair of TAPVR was done under mild hypothermic cardiopulmonary bypass (CPB) using esmolol, an ultra short-acting beta-blocker to obtain good operative field without aortic-cross clamping. Both cases were weaned from CPB uneventfully. Pulmonary venous obstruction was not found after surgery. This strategy seems to be applicable in pediatric cardiac surgery which is mainly limited to the atrial level.

Adrenergic beta-Antagonists↗