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Biomedical subjects

T Kazui

Publications and source records attributed to T Kazui.

At least 55 records · Page 3Linked to original sources
PubMed2001

Cerebral oxygenation monitoring for total arch replacement using selective cerebral perfusion.

BACKGROUND: This study was undertaken to verify the safety of our total arch replacement assisted by selective cerebral perfusion with respect to cerebral oxygenation. METHODS: Subjects to be evaluated were selected between February 1999 and March 2000 and comprised 13 patients who underwent total arch replacement (TAR) (TAR group) and 18 patients who had undergone coronary artery bypass grafting or valve replacement (control group). They were monitored throughout the operation by two-channel near-infrared spectroscopy. Changes in intracranial oxyhemoglobin and the tissue oxygenation index were compared between the two groups. Additionally, jugular venous oxygen saturation was simultaneously measured in 10 patients from each group. Maximum changes in these variables from baseline in the TAR group were compared with those in the control group. Bilateral oxygenation differences between two hemispheres were also evaluated. RESULTS: There was no incidence of postoperative cerebral infarction, and no significant difference was observed in the maximum decrease in these variables between the two groups. Bilateral oxygenation differences between the two hemispheres in the TAR group were similar to those in the control group, except for the tissue oxygenation index in the rewarming phase. CONCLUSIONS: From the standpoint of cerebral oxygenation, our technique of total arch replacement was nearly as safe as an ordinary cardiac operation.

Adult↗
PubMed2001

Role of biologic glue repair of proximal aortic dissection in the development of early and midterm redissection of the aortic root.

BACKGROUND: Redissection of the aortic root after supracommissural aortic graft replacement with reapproximation of the layers of the dissected aortic root is relatively rare. Causes and surgical treatment of this lesion remain controversial. METHODS: From January 1983 to September 2000, 130 patients had emergency operation for acute type A aortic dissection. Of them, 57 patients underwent root reconstruction using biologic glues and 4 patients (7.0%) developed redissection of the aortic root associated with moderate to severe aortic regurgitation 5 to 27 months after the initial operation. In all patients, the proximal false lumen was obliterated with infusion of gelatin-resorcinol-formaldehyde (GRF) glue or BioGlue and the aorta was reinforced with Teflon felt strip or Surgicel placed on its outside wall. RESULTS: During reoperation, the noncoronary aortic sinus was found to be redissected in all patients with the dissection extending retrogradely to the aortic annulus. This resulted in aortic regurgitation with prolapse of the noncoronary cusp because the proximal suture line dehisced. Histopathology showed disappearance of the nuclei of the medial smooth muscle cells, suggesting tissue necrosis at the site of GRF glue application. The lesions were treated successfully with full root replacement using a freestyle heterograft bioprosthesis or a composite graft prosthesis. CONCLUSIONS: The use of biologic glues for reapproximating the layers of the dissected aortic root is associated with a certain amount of risk of aortic wall necrosis. Therefore, care should be taken to ensure proper use of these glues. Full root replacement could be a preferable technique for treating redissection of the aortic root.

Adult↗
PubMed2001

Improved results of atherosclerotic arch aneurysm operations with a refined technique.

OBJECTIVE: We sought to analyze the postoperative hospital mortality and postoperative neurologic dysfunction in patients who had total arch replacement for atherosclerotic arch aneurysms using our recent refined technique. METHODS: Between June 1997 and April 2000, 50 consecutive patients underwent total arch replacement with an aortic arch branched graft for atherosclerotic arch aneurysms. Their mean age was 71 +/- 7 years (range, 57-87 years). Forty-eight (96%) patients were operated on electively, and the remaining 2 (4%) were operated on an emergency basis because of rupture of aneurysm. All operations were performed with hypothermic extracorporeal circulation, selective cerebral perfusion for cerebral protection during aortic arch repair, and systemic circulatory arrest during distal graft anastomosis. A total of 19 concomitant procedures were done in 17 patients. Mean selective cerebral perfusion time was 78.1 +/- 16.5 minutes. RESULTS: Overall in-hospital mortality was 2% (95% confidence intervals, 0%-5.9%). On univariable analysis, permanent neurologic dysfunction was the only risk factor for in-hospital mortality. Postoperative temporary and permanent neurologic dysfunctions were 4% (95% confidence intervals, 0%-9.4%) and 4% (95% confidence intervals, 0%-9.4%), respectively. On univariable analysis, cardiopulmonary bypass time was the only risk factor for temporary neurologic dysfunction, and history of cerebrovascular disease was the only risk factor for permanent neurologic dysfunction. There was no significant correlation between selective cerebral perfusion time and temporary and permanent neurologic dysfunction. CONCLUSION: Integrated cerebral protective effect of antegrade selective cerebral perfusion and total arch replacement with an aortic arch branched graft could substantially reduce in-hospital mortality and postoperative neurologic dysfunction in patients with atherosclerotic arch aneurysms.

Aged↗
PubMed2001

Experimental study on the effect of antegrade cerebral perfusion on brains with old cerebral infarction.

OBJECTIVE: Patients with old cerebral infarction who undergo aortic arch operations are susceptible to postoperative neurologic dysfunction. To verify such susceptibility, we performed this experimental study. METHODS: A cerebral infarct model was created in mongrel dogs by means of injection of cylindrical silicone embolus through the internal carotid artery. The dogs that had obvious neurologic deficits 1 day later and survived for 4 weeks or more were included in the cerebral infarct model. One month after cerebral infarction was induced, deep hypothermia and selective cerebral perfusion were used in 14 mongrel dogs (infarct group, n = 7; control group, n = 7). During this procedure, serum glutamate concentration and venous-arterial lactate difference were measured. Histopathologic study of the brain was also performed. RESULTS: Changes in venous-arterial lactate difference in both groups were almost similar, except in the rewarming phase. At 32 degrees C during rewarming, the venous-arterial lactate difference in the infarct group was significantly higher than that in the control group (P =.006). Although pre-cooling concentrations of serum glutamate were similar in both groups, the values in the infarct group at the end of rewarming were significantly higher than those in the control group (P =.046). On histologic examination, the presence of old cerebral infarction with gliosis was confirmed in the infarct group, but neither new cerebral infarction nor destruction of the blood-brain barrier was found. CONCLUSION: We observed an accelerated anaerobic metabolism and an increased extracellular glutamate release in the infarct group. The brain with old cerebral infarction is more susceptible to ischemia during arch operation than noninfarcted brain.

Animals↗
PubMed2001

Reduction of ischemic spinal cord injury by dextrorphan: comparison of several methods of administration.

OBJECTIVES: We investigated the effect of dextrorphan, an N -methyl-D -aspartate receptor antagonist, on the reduction of ischemic spinal cord injury and the safe clamping time after various methods of administration. METHODS: Spinal cord ischemia was induced in New Zealand White rabbits by infrarenal aortic clamping and animals were divided into 5 groups. Group A (n = 15) received simple clamping. Groups B (n = 20) and C (n = 35) received dextrorphan pretreatment (10 mg/kg), followed by continuous intravenous or intra-aortic infusion (1 mg/min), respectively. Group D (n = 25) received the same dextrorphan pretreatment and bolus intra-aortic injection at clamping (1 mg per minute of clamping time). Group E (n = 15) received bolus intrathecal injection of dextrorphan (0.2 mg/kg). Each dextrorphan-treated group had a small group of control animals (n = 5). The neurologic status was assessed by the Johnson score (5 = normal, 0 = paraplegic) 48 hours after unclamping, and animals were put to death for histopathologic examination. RESULTS: All dextrorphan-treated groups showed better neurologic function than the respective control animals (P <.001 vs groups B, C, and D; P =.014 vs group E). The order of efficacy of dextrorphan (as revealed by the average of neurologic status) was as follows: group C > group D (P =.017, after 50 minutes of clamping), group D > group B (P =.014, after 45 minutes of clamping), and group B > group E (P <.001, after 40 minutes of clamping). Histopathologic findings did not necessarily correspond with hind-limb neurologic function. CONCLUSIONS: Dextrorphan reduced the physical findings associated with ischemic spinal cord injury, and continuous intra-aortic infusion prolonged the safe clamping time significantly more than delivery by other routes.

Animals↗
PubMed2001

[Endoventricular circular patch plasty (dor operation) for postinfarction left ventricular aneurysm and ischemic cardiomyopathy].

The determination of purse-string suture line is one of the most important point in endoventricular circular patch plasty (Dor operation) for postinfarction left ventricular aneurysm (LVAN), especially for ischemic cardiomyopathy (ICM). We suggest following three points to decide appropriate suture line. First, the purse-string suture on the basal side should be placed on the 1-2 cm level under diagonal branch. Secondly, lateral wall should not be over excluded to maintain left ventricular function. And the third, akinetic or dyskinetic lesion of apex and septal wall should be excluded as much as possible. Nine cases of five LVAN and four ICM were underwent Dor operation in our institute from Dec. 1999 to Jan. 2000. All patients were weaned from cardiopulmonary bypass easily except one patient, who was operated under IABP support, because of his preoperative severe heart failure. All patients recovered well without any serious complications and postoperative left ventricular graphies were satisfactory. Left ventricular ejection fraction and stroke volume index were increased from 34 +/- 17 to 55 +/- 16% and from 38 +/- 7 to 47 +/- 6 ml/m2, end-diastric and systric volume index decreased from 141 +/- 37 to 88 +/- 19 ml/m2 and from 96 +/- 41 to 41 +/- 23 ml/m2 respectively. The Dor procedure adopted our idea led to satisfactory result in hemodynamic and also in morphologic study.

Aged↗
PubMed2001

Simple and safe cannulation technique for antegrade selective cerebral perfusion.

Antegrade Selective Cerebral Perfusion (SCP) has proved to be a safe and reliable method of brain protection during operations of aortic arch aneurysms. Arch vessel cannulation is a crucial step in the institution of SCP that determines its success to a significant extent. A simple and safe cannulation technique along with a newly developed flexible perfusion cannula is described.

Adult↗
PubMed2001

Overrepresentation of the EBAG9 gene at 8q23 associated with early-stage breast cancers.

EBAG9, an estrogen-responsive gene located at 8q23 was identified in an effort to clone CpG-binding sites. Its product was later found to be identical to RCAS1, a cancer cell-surface antigen implicated in immune escape. We determined the sequence of the complete cDNA and the genomic structure for EBAG9. EBAG9 gene copy number in 21% (27 of 129) primary breast cancers we examined; EBAG9 mRNA was consistently expressed in cancer cell lines. Detailed physical mapping of the 8q arm, including polymorphic markers for EBAG9 and the CMYC loci, revealed allelic gain of either EBAG9, CMYC, or both, in 45% (58 of 129) of the breast cancers we examined. The EBAG9 gene was increased exclusively in 16 of the 27 tumors showing gain at that locus; the other 11 showed gain of a larger chromosomal region containing both EBAG9 and CMYC. Analysis of subsequent series of 144 primary breast cancers for allelic gain at EBAG9 and CMYC locus showed a similar degree of gain at EBAG9, CMYC, or both. When a total of 273 breast cancers from two series were combined and analyzed for clinicopathological correlation, almost all of the tumors with EBAG9 increased but not those with CMYC. Twenty-eight of 29 were T1/T2 stage carcinomas (<5 cm in diameter), whereas one third (21 of 61) of the tumors in which CMYC was increased but EBAG9 was not, were advanced T3-stage tumors (P = 0.0012). These data suggest that EBAG9 and CMYC gene are independent targets of gain and that overrepresentation of EBAG9 may play a specific role in early stages of breast carcinogenesis.

Alleles↗
PubMed2000

Resected early lung cancer with pulmonary aspergilloma.

Pulmonary aspergillosis and lung cancer rarely occur simultaneously. We report a 66-year-old man with a round shadow in the thin-wall cavity of the right upper lobe. Radiological findings and transbronchial biopsy revealed squamous cell carcinoma complicated by aspergilloma at the site. Right upper lobectomy suggested that early lung cancer arose from preexisting lung scars containing an aspergilloma.

Aged↗
PubMed2000

Polymer sheet for covering tumors during endoscopic surgery.

It is recommended that tumor surface should be covered before resection in endoscopic surgery, but this is difficult to do, and no satisfactory method for this purpose has been reported. Therefore, we developed a polymer sheet to cover the wet surfaces of tumors. The sheet we developed is composed mainly of a cellulose derivative, ethyl citrate, and polyacrylic acid. Experimental and clinical study was performed to investigate the usefulness of the sheet. The sheet became attached to the organ surface by absorbing fluid secreted by tissues, and remained fixed for a period of 2 to 3 hours. No foreign body or allergic reaction was observed, and no postoperative infection occurred. The polymer sheet can be used safely for the purpose of covering tumors during endoscopic surgery.

Animals↗
PubMed2000

Total arch replacement using aortic arch branched grafts with the aid of antegrade selective cerebral perfusion.

BACKGROUND: We report our clinical experience with total arch replacement using aortic arch branched graft in an attempt to determine the independent predictors of both in-hospital mortality and neurologic outcome. METHODS: We studied 220 consecutive patients who underwent total arch replacement using aortic arch branched graft between May 1990 and June 1999. All operations were performed with the aid of hypothermic extracorporeal circulation, antegrade selective cerebral perfusion, and open distal anastomosis. RESULTS: The overall in-hospital mortality rate was 12.7%. Multivariable analysis showed independent determinants of in-hospital mortality to be chronic renal failure, long pump time, participation in early series, and shock. Postoperative permanent neurologic dysfunction was 3.3%. On multivariable analysis, old cerebral infarct and pump time were independent determinants of permanent neurologic dysfunction. The selective cerebral perfusion time had no significant influence on in-hospital mortality or neurologic outcome. The 5-year survival rate including in-hospital deaths was 79% +/- 6%. CONCLUSIONS: Selective cerebral perfusion allows increased ease of performance of total arch replacement, a complex and time-consuming procedure, and helps reduce periprocedural mortality and morbidity in patients with aortic arch aneurysm and those with acute aortic dissection.

Adolescent↗
PubMed2000

Extended total arch replacement for acute type a aortic dissection: experience with seventy patients.

OBJECTIVE: We sought to report the clinical experience with extended total arch replacement for acute type A aortic dissection and to determine the factors that influence early mortality, late survival, and late reoperation. METHODS: Between December 1988 and August 1998, 70 patients underwent emergency graft replacement of both the ascending aorta and the total aortic arch for acute type A aortic dissection. All operations were performed with hypothermic extracorporeal circulation, selective cerebral perfusion for cerebral protection during aortic arch repair, and open distal anastomosis. Concomitant procedures included aortic valve resuspension in 18 patients, composite graft replacement in 10 patients, and coronary artery bypass grafting in 5 patients. RESULTS: The early mortality rate was 16% (11 of 70 patients). Multivariable analysis showed that renal-mesenteric ischemia and coronary artery bypass grafting were independent determinants for early death. Survival rates at 3 and 5 years postoperatively, including the early deaths, were 75% +/- 5% and 73% +/- 6%, respectively. Multivariable analysis showed that renal-mesenteric ischemia and en bloc repair were independent determinants for late death. Freedom from reoperation was 91% +/- 4% and 77% +/- 8% at 3 and 5 years, respectively. Multivariable analysis showed that anastomotic leakage was the only significant determinant for late reoperation. CONCLUSIONS: Extended total arch replacement for acute type A aortic dissection could be justified in properly selected patients.

Acute Disease↗
PubMed2000

Surgical treatment of recurrent abdominal aortic aneurysm in a patient with systemic lupus erythematosus.

Reports of true abdominal aortic aneurysms (AAAS), especially those due to severe inflammation, in patients with systemic lupus erythematosus (SLE) are very few in number. However, we had the experience of surgically treating a recurrent AAA due to severe inflammation found in a patient with SLE. The recurrence took place after an earlier operation for an infrarenal AAA and involved the left renal artery. In both situations, the previous infrarenal aaa and the recurrence, the aneurysms demonstrated more rapid growth and more irregularities in shape. Etiology of the AAA might be a combination of Takayasu's arteritis and SLE because the two entities appeared to have overlapped.

Adult↗
PubMed2000

Intratumor heterogeneity of centromere numerical abnormality in multiple primary gastric cancers: application of fluorescence in situ hybridization with intermittent microwave irradiation on paraffin-embedded tissue.

Our recent success in retrieving distinct fluorescence signals in response to centromere specific probing of paraffin-embedded tissues after intermittent microwave (MW) treatment provided the opportunity to analyze chromosome numbers or centromere abnormality in situ in human tumors in various clinicopathological settings. In this study, centromere numerical abnormality (CNA) was investigated by fluorescence in situ hybridization (FISH) in a case of multiple gastric cancer having intratumor histological heterogeneity. The different profiles as determined using a total of 20 specific probes on 4 multifocal lesions in the stomach confirmed the multi-clonality of these tumors. FISH with probes specific for chromosomes 10, 11, 16 and 18 revealed intratumor heterogeneity of the CNA, which corresponded to the histological heterogeneity. Our report clearly demonstrates, for the first time, intratumor heterogeneity of CNA and its association with the histological picture, and substantiates the applicability of the MW-assisted FISH protocol to paraffin-embedded pathological specimens.

Centromere↗
PubMed2000

[A case of localized nodular pulmonary amyloidosis diagnosed by video-assisted thoracoscopic surgery].

Pulmonary amyloidosis is a rare pulmonary lesion. We report a 42-year-old male admitted for further evaluation of abnormal chest shadow. A chest CT demonstrated a nodular shadow in right S3. We tried transbronchial and percutaneous lung biopsy, but could not diagnose. We performed partial lung resection by video-assisted thoracoscopic surgery. Pathological diagnosis of the lesion was pulmonary amyloidosis. Immunohistochemical examination revealed this amyloid composed of AL kappa protein. No clinical evidence of amyloid deposits were found in other organs. We finally diagnosed this case as a localized nodular pulmonary amyloidosis.

Adult↗
PubMed1999

Prolonged cardiac allograft survival in rats systemically injected adenoviral vectors containing CTLA4Ig-gene.

BACKGROUND: CTLA4Ig, a soluble recombinant fusion protein that contains the extracellular domain of the CTLA4 and Fc portion of IgG1, strongly adheres to the B7 molecule to block CD28-mediated costimulatory signals and inhibits in vitro and in vivo immune responses. In vivo gene transfer using adenovirus vector achieves a high transfection rate into organ cells that usually contain adenoviral receptors. In this study, we investigated expression levels of the transfected gene and the survival times of the allografts in cardiac recipients systemically administered adenoviral vectors containing CTLA4Ig. METHODS: Hearts from DA rats (RT-1a) were transplanted into a cervical location in LEW recipients (RT1(1)). The adenoviral vectors containing CTLA4Ig was injected via a recipient vein immediately after grafting. RESULTS: The serum level of CTLA4Ig reached to maximum at 51-93 microg/ml 3 to 7 days after gene-transfection and declined after 14 days, although detectable levels were observed up to 49 days. The median survival time of the allografts in the gene-transfected group were significantly prolonged (27 days) in compared to the control group (6 days). In addition, down-regulation of IL-2 and IFN-gamma mRNAs and persistence of IL-4 and IL-10 transcripts were observed in the graft infiltrating cells. CONCLUSION: The adenovirous-mediated CTLA4Ig gene transfer into a recipient liver by systemic administration resulted in remarkable prolongation of cardiac allograft survival. Its action mechanisms may be mediated by inhibition of CD28-associated signal transduction, reduction of Th1-type cytokine production, and continuous expression of Th2-type cytokines in the activating lymphocytes.

Abatacept↗
PubMed1999

Diaphragm reconstruction with autologous fascia lata: report of a case.

When the diaphragm is excised so widely that the defect cannot be closed directly during an operation on either thoracic or epigastric tumors, a reconstruction of the defect is necessary. We used harvested autologous fascia lata to reconstruct the diaphragm in a patient undergoing a pleuropneumonectomy with a partial diaphragmatic resection for malignant mesothelioma.

Adult↗