PubMed Health⌕ Search

Biomedical subjects

K Kuwaki

Publications and source records attributed to K Kuwaki.

At least 19 recordsLinked to original sources
PubMed2005

Troponin T levels in baboons with pig heterotopic heart transplants.

Troponin T levels have been monitored in baboons (n = 8) undergoing pig heterotopic heart transplantation, and correlated with a decrease in graft contractions and graft survival. Pig heart graft survival was from 12 to 139 days (mean 45, median 33), and graft failure was associated with predominant thrombotic microangiopathy and ischemia, with focal hemorrhage, and edema. An increase in troponin T levels 5 to 6 days before graft failure correlated closely with diminished graft contractions. An increase in troponin T was a reliable indicator that graft dysfunction was occurring.

Animals↗
PubMed2005

Effect of ruminal administration of Escherichia coli wild type or a genetically modified strain with enhanced high nitrite reductase activity on methane emission and nitrate toxicity in nitrate-infused sheep.

The effects of two kinds of Escherichia coli (E. coli) strain, wild-type E. coli W3110 and E. coli nir-Ptac, which has enhanced NO(2) reduction activity, on oral CH(4) emission and NO(3) toxicity in NO(3)-treated sheep were assessed in a respiratory hood system in a 4 x 6 Youden square design. NO(3) (1.3 g NaNO(3)/kg(0.75) body weight) and/or E. coli strains were delivered into the rumen through a fistula as a single dose 30 min after the morning meal. Escherichia coli cells were inoculated for sheep to provide an initial E. coli cell density of optical density at 660 nm of 2, which corresponded to 2 x 10(10) cells/ml. The six treatments consisted of saline, E. coli W3110, E. coli nir-Ptac, NO(3), NO(3) plus E. coli W3110, and NO(3) plus E. coli nir-Ptac. CH(4) emission from sheep was reduced by the inoculation of E. coli W3110 or E. coli nir-Ptac by 6 % and 12 %, respectively. NO(3) markedly inhibited CH(4) emission from sheep. Compared with sheep given NO(3) alone, the inoculation of E. coli W3110 to NO(3)-infused sheep lessened ruminal and plasma toxic NO(2) accumulation and blood methaemoglobin production, while keeping ruminal methanogenesis low. Ruminal and plasma toxic NO(2) accumulation and blood methaemoglobin production in sheep were unaffected by the inoculation of E. coli nir-Ptac. These results suggest that ruminal methanogenesis may be reduced by the inoculation of E. coli W3110 or E. coli nir-Ptac. The inoculation of E. coli W3110 may abate NO(3) toxicity when NO(3) is used to inhibit CH(4) emission from ruminants.

Animals↗
PubMed2004

Reduction of anti-Galalpha1,3Gal antibodies by infusion of types 2 and 6 gal trisaccharides conjugated to poly-L-lysine.

To investigate the specificity of anti-Galalpha1,3Gal (Gal) antibodies (Abs) with respect to Gal oligosaccharides of types 2 and 6, eight baboons received an intravenous infusion of either a poly-l-lysine conjugate of Gal type 2 (n = 5) or type 6 (n = 3), followed 48 h later by the alternative Gal type 6 or 2 conjugate, respectively. IgM Abs reactive to Gal type 2 were depleted by 80 to 89% by either Gal conjugate. IgM reactive to Gal type 6 was less efficiently depleted by the Gal type 2 conjugate (57% depletion) than the Gal type 6 (82% depletion). Gal-reactive IgG was depleted more slowly and less efficiently by either glycoconjugate (initially by only 28 to 54%). Our results indicate that the Gal type 6 conjugate depletes most anti-Gal IgM, but the Gal type 2 conjugate is less efficient in depleting anti-Gal IgM reactive with type 6. There remain small fractions of antibody that are unadsorbed, particularly of IgG, probably due to their low affinity and distribution in both the intra- and extra-vascular compartments.

Animals↗
PubMed2004

Absence of humoral and cellular alloreactivity in baboons sensitized to pig antigens.

AIM: to study whether sensitization to pig antigens results in humoral and/or cellular sensitization to alloantigens in baboons, and thus increases the risks of organ allotransplantation after xenotransplantation. Serum from baboons that were naive (n = 4), sensitized to Gal alpha 1,3Gal (Gal) antigens (n = 2), or sensitized to Gal + non-Gal pig antigens (n = 2) were tested by flow cytometry for the presence of immunoglobulin G (IgG) and IgM antibodies that bind to pig or baboon peripheral blood mononuclear cells (PBMC). Two allosensitized baboons were used as positive controls. The same 10 sera were tested in a complement-mediated cytotoxicity assay to detect cytotoxic antibodies against pig, allo and self-PBMC. The T-cell responses of the same baboons to allogeneic and pig PBMC stimulators in mixed lymphocyte reaction (MLR) were studied. All baboon sera contained cytotoxic antibodies that bound to pig PBMC. Binding and cytotoxicity were higher in xenosensitized baboons, particularly in those sensitized to Gal + non-Gal antigens (P < 0.001). None of the naive or xenosensitized baboon sera bound to baboon PBMC. Serum from allosensitized baboons showed anti-baboon IgG and IgM binding, but there was no increase in binding to pig PBMC or in cytotoxicity to pig cells. The MLR response to pig stimulators in baboons sensitized to non-Gal pig antigens was greater than that of naive or Gal-sensitized baboons (P < 0.001), but there was no increase in the response to baboon cells. In baboons, no in vitro evidence that a previous pig xenograft might endanger the outcome of a subsequent allograft was documented.

Animals↗
PubMed2004

Bone marrow transplantation from alpha1,3-galactosyltransferase gene-knockout pigs in baboons.

BACKGROUND: Successful hematopoietic cell allotransplantation results in donor-specific tolerance, but this approach has been unsuccessful in the wild-type pig-to-baboon xenotransplantation model, as pig cells were lost from the circulation within 5 days. However, after cessation of immunosuppressive therapy on day 28, all baboons demonstrated non-specific unresponsiveness on mixed leukocyte reaction (MLR) for at least 30 days. We have now investigated the transplantation of bone marrow (BM) cells from miniature swine homozygous for alpha1,3-galactosyltransferase gene-knockout (GalT-KO). METHODS: Baboons (n = 3) were pre-treated with whole body and thymic irradiation, anti-thymocyte globulin, and splenectomy, and received immunosuppressive and supportive therapy for 28 days. BM was harvested from GalT-KO swine (n = 3). The baboons were monitored for the presence of pig cells by flow cytometry and colony-forming units (CFUs), and for cellular reactivity by MLR. RESULTS: A mean of 11 x 10(8) BM cells/kg was infused into each baboon. The mean absolute numbers and percentages of pig cells detected in the blood at 2 h and on days 1, 2 and 4, respectively, were 641/microl (9.5%), 132/microl (3.4%), 242/microl (3.9%), and 156/microl (2.9%). One baboon died (from accidental hemorrhage) on day 6, at which time chimerism was present in the blood (2.0%) and BM (6.4%); pig cell engraftment in the BM was confirmed by polymerase chain reaction (PCR) of CFUs. In the two other baboons, blood chimerism was lost after day 5 but returned at low levels (<1%) between days 9 to 16 and 7 to 17, respectively, indicating transient BM engraftment. Both surviving baboons showed non-specific unresponsiveness on MLR until they were euthanized on days 85 and 110, respectively. CONCLUSIONS: By using BM cells from GalT-KO pigs, chimerism was detected at levels comparable with previous studies when 30-fold more growth factor-mobilized peripheral blood progenitor cells had been transplanted. In addition, cellular hyporesponsiveness was prolonged. However, long-term engraftment and chimerism were not achieved.

Animals↗
PubMed2001

Traction-type heart stabilizer for off-pump coronary bypass grafting.

We designed a stabilizer to assist us in performing coronary artery bypass grafting on the beating heart. The stabilizer consists of a U-shaped holed platform, an articulating arm, and a clamp for attachment to an ordinary sternal retractor. The target coronary artery is dissected, then two elastic sutures, 15-20mm apart, are wrapped around it, proximal and distal to the anastomotic site. These sutures for traction are passed through holes in the U-shaped platform and tied. This traction immobilizes the target area of the coronary artery. The stabilizer described herein provides good exposure and steady immobilization to enable anastmosis to be more easily performed in the beating heart.

Anastomosis, Surgical↗
PubMed2001

Tricuspid valve surgery for functional tricuspid valve regurgitation associated with left-sided valvular disease.

OBJECTIVES: We have reviewed 260 patients who underwent initial tricuspid valve surgery for functional tricuspid valve regurgitation (TR) and analyzed independent predictors for early and late unfavorable results. MATERIALS AND METHODS: Between 1981 and 1998, 260 tricuspid valve operations were performed for functional TR. There were 94 males and 166 females with a mean age of 55 years. The tricuspid valve surgery procedures consisted of De Vega tricuspid annuloplasty in 240 patients, ring annuloplasty in four patients, and tricuspid valve replacement in 16 patients. The mean duration of follow-up was 7.8 years. RESULTS: Hospital mortality was 8.9% (23 patients). Late deaths occurred in 34 patients including cardiac-related late deaths in 26 patients. The survival rates were 83+/-2% at 5 years and 78+/-3% at 10 years. Late tricuspid valve reoperation was performed on 13 patients due to residual or recurrent TR in 12 patients and thrombosed tricuspid bileaflet mechanical valve in one patient. The tricuspid valve reoperation-free survival rate was 90+/-2% at 5 years and 84+/-3% at 10 years. The only predictor of hospital mortality was preoperative highly elevated right atrial pressure (P=0.01). Variables predictive of cardiac-related late death were preoperative New York Heart Association (NYHA) class IV (P=0.01) and poor left ventricular ejection fraction (LVEF) (P=0.02). Residual TR of more than grade 2+ early after tricuspid annuloplasty was a significant risk factor for late tricuspid valve reoperation (P=0.01). Preoperative TR of grade 4+ was predictive of early residual TR (P=0.04). CONCLUSIONS: Tricuspid valve surgery for functional TR can be performed with acceptable levels of early mortality. Cardiac-related late mortality after tricuspid surgery may be improved by earlier surgical treatment before NYHA class IV or deterioration of LVEF occurs. To prevent late tricuspid reoperation, it is important not to leave residual TR of grade 2+ or more after tricuspid annuloplasty.

Aged↗
PubMed2001

Endoventricular circular patch plasty for end-stage valvular cardiomyopathy.

We present here a case of end-stage non-ischemic valvular dilated cardiomyopathy (DCM) associated with mitral regurgitation (MR). The patient underwent surgery where left ventricular volume reduction using endoventricular circular patch plasty (EVCPP) and mitral valve replacement (MVR) were performed. He has improved much after the operation and is now in New York Heart Association (NYHA) functional class II.

Aged↗
PubMed2000

Graft replacement for huge aneurysm of the main pulmonary artery.

We present 2 cases of huge aneurysm of the main pulmonary artery without significant pulmonary artery hypertension or intracardiac shunt. Both patients underwent surgery where resection of the aneurysm and graft replacement, using Hemashield prosthesis (Meadox Medicals, Oakland, NJ), was performed. They are now leading normal lives without any symptoms.

Aged↗
PubMed2000

Surgical repair of the pulmonary trunk aneurysm.

OBJECTIVE: Aneurysm formation of the pulmonary trunk is rare and there is controversy about optimal treatment for this disease. The aim of this article is to report four patients with pulmonary trunk aneurysm which were managed by surgical repair. MATERIALS AND METHODS: From 1986 to 1997, we performed surgical repair for pulmonary trunk aneurysm in four patients. There was one male and three female patients with a mean age of 63.3 years (range: 54-78 years). Concomitant diseases were cardiac valvular disease in four patients, thoracic aortic dissection in two, atherosclerotic abdominal aortic aneurysm in two, and coronary artery disease in one. All patients were in New York Heart Association functional class III preoperatively. Surgical procedures for the pulmonary trunk aneurysm included Dacron graft replacement in two patients and aneurysmorrhaphy in two. Associated procedures were cardiac valvular operation in three patients with four lesions and right ventricular outflow tract reconstruction (RVOTR) in one. RESULTS: There were no operative mortalities and no late deaths with a mean follow-up period of 6.6 years (range: 2.4-10.0 years). One female patient developed recurrent pulmonary trunk aneurysm 9.5 years after aneurysmorrhaphy, and underwent a second operation where Dacron graft replacement of the aneurysm including pulmonary valve replacement was performed successfully. All patients are now leading normal lives. CONCLUSIONS: Surgical management should be considered for large aneurysm of the pulmonary trunk regardless of its etiology and underlying disease to prevent possible rupture with fatal result if the patient has an acceptably low operative risk.

Aged↗
PubMed2000

Surgical treatment of a large, highly mobile atheroma in the ascending aorta.

A 53-year-old woman diagnosed with chronic renal failure requiring homodialysis, and Behçet's disease was found, during a regular examination, having a large protruding mobile atheroma in the ascending aorta by transthoracic echocardiography. We performed surgery to remove the atheroma and localized debridement using moderate hypothermic circulatory arrest to prevent future stroke and embolism. She had an uneventful postoperative course.

Aortic Diseases↗
PubMed2000

Improvement of ischaemia-reperfusion injury by lazaroid U74389G in rat lung transplantation model.

The effect of lazaroid 74389G on ischaemia-perfusion injury in a rat lung transplantation model was investigated using three administration methods. In all groups, the University of Wisconsin (UW) solution was used as a flush and preservation solution at 4 degrees C, and lungs were stored for 12 h. Group I rats (controls) were not given any lazaroid treatment. In group II, lazaroid U74389G was added to the UW solution (100 micromol/l). In group III, lazaroid (10 mg/kg) was intravenously injected in the donors 30 min before lung ischaemia. Group IV received lazaroid treatment by the combined methods of groups II and III. In all the experimental groups (II-IV), recipient rats were given lazaroid (6 mg/kg) intravenously 30 min before reperfusion. Lazaroid improved the gas exchange function (groups II, III and IV), reduced the tissue lipid peroxides (group II) and ameliorated histologic lung damage (group II). The results thus seemed to be better in group II than in groups III and IV.

Animals↗
PubMed2000

Early and late results of mitral valve repair for mitral valve regurgitation. Significant risk factors of reoperation.

BACKGROUND: Mitral valve repair for mitral valve regurgitation has many advantages over mitral valve replacement. However, durability and reoperation after mitral valve repair still remain major problems. We examined the outcome of mitral valve repair for mitral valve regurgitation and analyzed several pre- and intraoperative potential risk factors to determine the significant risk factors of reoperation. METHODS: From February 1981 to November 1996, 86 patients underwent mitral valve repair for mitral regurgitation or combined mitral regurgitation and stenosis. The mean age was 53 years, and 88.4% were New York Heart Association class III or IV. The causes of mitral valve disease were degenerative disease in 53 patients, rheumatic disease in 15, infective endocarditis in 11, and ischemic disease in 7. There were 2 early and 8 late deaths. RESULTS: Actuarial overall survival including early death at 10 years was 83.2+/-6.1%, freedom from reoperation was 86.8+/-5.3%, freedom from thromboembolism was 90.9+/-6.2%, and freedom from infective endocarditis was 98.5+/-1.5%. There was no bleeding event. At the last follow-up, most patients were in New York Heart Association class I or II. Prolapse of anterior leaflet and rheumatic mitral regurgitation were identified as independent predictors for reoperation. CONCLUSIONS: The repair techniques for anterior leaflet prolapse and patient selection in rheumatic mitral disease are important for improving long-term results of mitral valve repair for mitral regurgitation.

Adolescent↗
PubMed2000

[A novel instrument for off-pump coronary artery bypass grafting: traction-type coronary artery stabilizer].

A new instrument for heart stabilization during beating coronary bypass grafting without cardiopulmonary bypass and a clinical experience of off-pump LITA-to-LAD bypass using this mechanical stabilizer are described. This device provide optimal motionless field by traction mechanism in which traction sutures placed proximal and distal to the target coronary artery are tied to the U-shaped foot plate with multiple small holes. The advantages of this stabilizer are as follows; no need of heart compression, ability to displace the target lesion to facilitate anastomosis, reusable, compact size and easy handling. We believe this novel instrument will improve the anastomosis quality in patient undergoing coronary artery bypass without cardiopulmonary bypass.

Aged↗
PubMed2000

Saphenous vein patch angioplasty for a discrete saccular aneurysm of left anterior descending coronary artery.

We present here a case of discrete saccular coronary artery aneurysm located astride bifurcation between the left anterior descending artery and first diagonal branch in the absence of severe coronary artery occlusive disease. The patient underwent surgery where complete resection of the aneurysm and patch angioplasty using saphenous vein graft were performed. Postoperative coronary angiography revealed disappearance of the aneurysm and no stenosis of the repaired coronary artery. The patient is now leading a normal life without any symptoms one year after the operation.

Aged↗
PubMed1999

The effect of various doses of lazaroid U74389G on lung ischemia reperfusion injury.

BACKGROUND: We investigated the effect of lazaroid U74389G, a potent inhibitor of lipid peroxidation, on ischemia-reperfusion injury at three different doses in the rat orthotopic left lung transplantation model. METHODS: Four groups of reperfused lungs were studied. In group I (control) donor lungs were transplanted after 12 hours of preservation in University of Wisconsin (UW) solution at 4 degrees C. In groups II, III, and IV, lazaroid was used as an additive to UW solution at concentrations of 30 micromol/L, 50 micromol/L, and 100 micromol/L, respectively, and was also administered intravenously to the recipients 30 minutes before reperfusion after 12 hours of storage in the UW solution at 4 degrees C. RESULTS: After 1 hour of reperfusion, gas exchange function (p < 0.01), tissue lipid peroxide levels (p < 0.05) and histologic damage in reperfused lung allografts (p< 0.05) were significantly improved in lazaroid-treated group IV compared with control group I. CONCLUSIONS: These findings suggest that lazaroid U74389G ameliorates ischemia-reperfusion injury in rat lung transplants by inhibiting lipid peroxidation.

Animals↗