PubMed Health⌕ Search

Biomedical subjects

S Eguchi

Publications and source records attributed to S Eguchi.

At least 19 recordsLinked to original sources
PubMed1997

Aortic arch operation using selective cerebral perfusion for nondissecting thoracic aneurysm.

BACKGROUND: Risks of increasing mortality and disability in aortic arch operations using the selective cerebral perfusion method for nondissecting aneurysm have not yet been determined. A multicenter, retrospective study was employed. METHODS: The subjects were 143 patients who were admitted to one of the nine cardiovascular centers between January 1988 and December 1993, including 15 with ruptured aneurysm. A graft replacement of the transverse aortic arch or distal arch was performed in 80 patients, extensive aortic reconstruction comprising simultaneous replacement of the ascending or descending thoracic aorta (or both) in 46, and patch repair of involved arch in 17. The mean postoperative follow-up period was 19 months. RESULTS: Hospital mortality was 36/143 patients (25.2%). Univariate analysis revealed that age of 70 years or more, ruptured aneurysm, and renal dysfunction affected hospital mortality. Neurologic deficits were noted in 15 patients (10.5%). Reoperation was performed in 13 patients for residual distal aneurysm or false aneurysm. Late death occurred in 10 patients and were due to vascular complications in 6. Multivariate analysis confirmed that aneurysmal rupture and renal dysfunction were independent predictors for vascular death including hospital mortality. CONCLUSIONS: The present study confirmed that age, aneurysmal rupture, and renal dysfunction were significant predictors for mortality and disability in the aortic arch operation using selective cerebral perfusion for nondissecting thoracic aneurysm.

Aged↗
PubMed1997

Operation for nondissecting aneurysm in the descending thoracic aorta.

BACKGROUND: Little is known about the risks of mortality and morbidity after descending thoracic aortic aneurysm repair using left heart bypass and temporary arterioarterial bypass. METHODS: A multicenter, retrospective study was performed on 120 patients who were admitted to one of nine cardiovascular centers between January 1988 and December 1993 and underwent operation for nondissecting thoracic aortic aneurysm. The present series included 10 patients with ruptured aneurysm. Graft replacement was performed in 95 patients, patch repair in 22, and suture of the ruptured aorta in 3. Venoarterial bypass was used in 45 patients, left heart bypass in 56, and temporary arterioarterial bypass in 19 as circulatory support. The mean postoperative follow-up period was 30 +/- 21 months. RESULTS: Hospital mortality occurred in 7 patients (5.8%). Univariate analysis revealed that only aneurysmal rupture was related to hospital mortality. Brain or cord injury was observed in 4. Of nine deaths that occurred after discharge, five were related to aneurysm and two were due to vascular event. No significant difference was noticed in probability of survival according to the circulatory supporting method. Only aneurysmal rupture affected probability of survival. Multivariate analysis revealed that aneurysmal rupture was the only independent predictor for vascular death including hospital mortality. CONCLUSIONS: The present study confirms that aneurysmal rupture is a significant predictor for mortality and morbidity in aortic operations for nondissecting descending thoracic aneurysm, and that a similarly good outcome would be expected when using left heart bypass, temporary arterioarterial bypass, or venoarterial bypass.

Aged↗
PubMed1997

[Surgical treatment of T4 lung cancer: combined resection of lung and heart or great vessels].

From 1980 to 1995, sixteen patients with T4 lung cancer underwent resection of left atrium (LA) or great vessels combined with pulmonary resection. For eight patients with lung cancer invading LA, LA was resected under simple clamp of LA in seven cases, and under extracorporeal circulation in one case. For three patients with lung cancer invading aorta, resection and reconstruction of aorta was performed under femoro-femoral bypass in one case, and under temporary bypass using a heparin-coated tube in two cases. For five patients with lung cancer invading superior vena cava (SVC), SVC was resected under partial clamp or simple clamp of SVC in each case. In remaining three patients, SVC was resected under internal bypass in one case, and under temporary bypass using a heparin-coated tube in two cases. Three were two operative deaths, one (SVC) died of acute heart failure, and the other (LA) died of acute respiratory distress syndrome. Four patients are alive without recurrence and three of them (one LA and two SVC) have been surviving more than five years after operation.

Aged↗
PubMed1996

Inhibition of cell proliferation and activation of protein tyrosine phosphatase mediated by angiotensin II type 2 (AT2) receptor in R3T3 cells.

Angiotensin II (Ang II) type 2 receptor (AT2) mediated inhibition of cell proliferation and activation of protein tyrosine phosphatase (PTP) were investigated in R3T3 fibroblast cells selectively expressing the AT2 subtype. Ang II did not alter the cell number of serum depleted R3T3 cells but inhibited basic fibroblast growth factor (bFGF)-stimulated cell proliferation in a dose dependent manner (IC50; 1-5 nM). This inhibitory response was abolished by an concomitant incubation with an AT2 antagonist, PD123319, and was mimicked by an AT2 agonist, CGP42112A. Stimulation of Ang II resulted in a rapid and transient increase in PTP activity as determined by using para-nitrophenyl phosphate (p-Npp) as a substrate in serum depleted R3T3 cells. This PTP activation was mimicked by CGP42112A. We conclude that the AT2 receptor is involved in the inhibition of cell proliferation and activation of protein tyrosine phosphatase.

3T3 Cells↗
PubMed1996

Treatment of hypercholesterolemia in the Watanabe rabbit using allogeneic hepatocellular transplantation under a regeneration stimulus.

Numerous studies have reported successful allotransplantation of hepatocytes. However, none have shown long-term correction of a liver-related metabolic defect. In this study, we used a method of regional hepatocyte transplantation and subsequent induction of transplanted cell proliferation by regeneration response in the transplant-bearing liver lobes. New Zealand White rabbits were used as cell donors and Watanabe heritable hyperlipidemic (WHHL) rabbits were used as cell recipients (2 x 10(8) cells/rabbit). All recipient rabbits were maintained on daily cyclosporine. Two weeks after baseline serum cholesterol determination, group I WHHL rabbits (n = 7) received an infusion of cells into the right lateral liver lobe, and a loose ligature was placed around the portal venous branch supplying the anterior lobe. After 1 week, to allow engraftment, the portal venous branch was ligated, which resulted in the atrophy of the affected liver parenchyma and induction of hyperplasia in the transplant-bearing liver tissue. Group II rabbits (n = 6) were transplanted with New Zealand White hepatocytes without portal branch ligation (PBL) and group III rabbits (n = 4) were subjected to sham transplantation (saline) and PBL. The experimental period extended to 150 days after transplantation. All WHHL rabbits transplanted with normal hepatocytes showed reduction in serum cholesterol and low-density lipoprotein (LDL) levels. Group I (PBL-stimulated) recipients demonstrated a more pronounced and sustained effect than group II animals (P < 0.05). Group III controls showed only a slight, typical for aging decrease in serum cholesterol. Group I recipient livers perfused with LDL labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate (DiI) showed much higher numbers of DiI-LDL-positive hepatocytes than those of group II recipients. In conclusion, a liver regeneration stimulus enhanced the population of transplanted hepatocytes and their functional effect in a large animal model of inborn error of liver metabolism.

Alanine Transaminase↗
PubMed1996

Identification of an essential signaling cascade for mitogen-activated protein kinase activation by angiotensin II in cultured rat vascular smooth muscle cells. Possible requirement of Gq-mediated p21ras activation coupled to a Ca2+/calmodulin-sensitive tyrosine kinase.

In cultured rat vascular smooth muscle cells, angiotensin II (Ang II) induced a rapid increase in mitogen-activated protein kinase (MAPK) activity through the Ang II type 1 receptor, which was insensitive to pertussis toxin but was abolished by the phospholipase C inhibitor, U73122. The Ang II-induced MAPK activation was not affected by the protein kinase C inhibitor, GF109203X, and was only partially impaired by pretreatment with a phorbol ester, whereas both treatments completely prevented MAPK activation by the phorbol ester. Intracellular Ca2+ chelation by TMB-8, but not extracellular Ca2+ chelation or inhibition of Ca2+ influx, abolished Ang II-induced MAPK activation. The calmodulin inhibitor, calmidazolium, and the tyrosine kinase inhibitor, genistein, completely blocked MAPK activation by Ang II as well as by the Ca2+ ionophore A23187. Ang II caused a rapid increase in the binding of GTP to p21(ras), and this was inhibited by genistein, TMB-8, and calmidazolium but not by pertussis toxin or GF109203X. These data suggest that Ang II-induced MAPK activation through the Ang II type 1 receptor could be mediated by p21(ras)activation through a currently unidentified tyrosine kinase that lies downstream of Gq-coupled Ca2+/calmodulin signals.

Adenosine Triphosphate↗
PubMed1996

Mutations of the p53 gene in the stool of patients with resectable colorectal cancer.

BACKGROUND: This study was undertaken to evaluate whether genetic analysis in the stool can be useful for detecting malignant tumors in the colon and rectum. We searched for the possible presence of mutations in the p53 gene in the stool of patients with resectable colorectal cancer. Alterations in the p53 gene are the most frequent among mutant genes related to colorectal cancer. METHODS: Surgically resected tumor specimens and stool samples from 25 patients with colorectal cancer were examined for mutations of exons 5-8 of the p53 gene by polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP). Results were compared with those achieved by fecal occult blood testing. RESULTS: Mutations of the p53 gene were found in the tumor tissues in 11 of 25 patients (44%). Of these 11 patients, 7 (64%) had evidence of alterations in the p53 gene within the stool. Of five patients who were negative for fecal occult blood testing, p53 mutations in the stool were evident in three patients. CONCLUSIONS: This method of stool DNA analysis for tumor-specific mutations is expected to have a wide application in clinical screening for colorectal cancer.

Adult↗
PubMed1996

Fulminant hepatic failure in rats: survival and effect on blood chemistry and liver regeneration.

A reproducible experimental animal model of fulminant hepatic failure (FHF) resembling the clinical condition is needed. We have developed such a model in the rat by combining resection of the two anterior liver lobes (68% liver mass) with ligation of the right lobes pedicle (24% liver mass), resulting in liver necrosis; the remaining two omental lobes (8% liver mass) are left intact. Adult Sprague-Dawley rats (250-300 g) were used. Survival time was determined in 60 rats. Because maintenance of body temperature at 37 degrees C shortened survival time by half, FHF rats were not warmed during the postinduction period and were allowed to gradually enter a state of mild to moderate hypothermia (29-32 degrees C). Additionally, 42 FHF rats were killed in batches of six rats each 2, 6, 12, 18, 24, 30, and 36 hours postoperatively to evaluate changes in blood chemistry (glucose, lactate, liver function tests, prothrombin time) and to assess liver regenerative response in the residual omental liver lobes (weight, protein content, incorporation of bromodeoxyuridine [BrdU], expression of proliferation cell nuclear antigen [PCNA], mitotic activity), plasma levels of hepatocyte growth factor (HGF) and transforming growth factor beta (TGF-beta1), and tissue expression of the HGF and it's receptor c-met. Rats undergoing partial hepatectomy of 68% (PH; n = 42) and a sham operation (SO; n = 42) served as controls. All SO and PH controls survived. PH rats showed only transient decreases in body temperature, signs of modest early hepatic dysfunction (hyperlactemia, hyperammonemia, prolonged PT time), and normal restitution of liver mass. All FHF rats became comatose by 24 hours postoperatively. Most animals (90%) died within 24-48 hours postoperatively (mean, 39 +/- 11 hours). Changes in blood chemistry reflected rapid development of liver failure. Plasma HGF levels were markedly elevated and at all time points were higher than in PH controls (P < .05). At the same time, expression of HGF and c-met messenger RNA in the remnant liver was delayed. Plasma TGF-beta1 levels increased early (18 hours) and remained twofold to threefold higher than that of PH and SO controls (P < .05). There was only a 20% increase in the weight of the remnant liver lobes due to swelling. No hepatocytes stained positively for BrdU and PCNA, and none showed mitotic figures. In contrast, all PH controls showed vigorous liver regeneration. In conclusion, we have developed and characterized a novel model of FHF in rats that has a number of physiological and biochemical features seen clinically in FHF, including severely impaired ability of the residual liver tissue to regenerate.

Animals↗
PubMed1996

Surgical implication of aortic dissection on long-term outcome in Marfan patients.

We herein review our 17-year surgical experience for the treatment of ascending aortic aneurysm in patients with Marfan syndrome to clarify the risks of increased mortality and reoperation. The subjects consisted of 15 patients who had all undergone surgery for the aortic root and ascending aorta at Niigata University Hospital between July 1978 and January 1995. Aortic valve replacement and ascending aortic wrapping were performed in 5 patients, Bentall or Cabrol operation in 6, and combined aortic arch reconstruction and Cabrol operation in 2, as the initial surgery. Patients who had an aortic dissection (Stanford type A) at initial surgery were assigned to group I (n = 7), while those with an aortic root aneurysm were assigned to group II (n = 8). In group I, 3 patients required a second operation for the remaining aortic arch aneurysm, and 1 died due to a late rupture of the distal aneurysm. In group II, no patient needed a reoperation; however, 1 died due to an intracranial hemorrhage and another due to composite valve graft failure and distal dissection. The results thus indicate that aortic dissection seems to affect long-term outcome, and therefore the combined repair of the aortic root and transverse arch is recommended in Marfan patients with aortic dissection involving the transverse aortic arch.

Adolescent↗
PubMed1996

The long-term influence of pulmonary valve regurgitation following repair of tetralogy of Fallot: does preservation of the pulmonary valve ring affect quality of life?

The transannular patch (TAP) repair used in the correction of tetralogy of Fallot (TOF) inevitably causes pulmonary regurgitation. We report herein the results of a long-term follow-up study conducted on 50 patients who had undergone a TAP repair 20-29 years earlier to evaluate the influence of pulmonary regurgitation on their late outcome and quality of life. As a control, 26 patients with an intact pulmonary valve ring and right ventricular outflow patch (RVP) confined to the subvalvular region were also studied. The 25-year survival rates of the TAP and RVP groups were 88.5% and 95.7%, respectively, and the event-free rates at 25 years were 73.3% and 90.9%, respectively. Although the absolute values of these rates were higher in the RVP group, there were no statistically significant differences between the two groups. To assess quality of life, the occupational status, childbearing ability, and late symptoms were evaluated, and found to be comparable between the two groups. Moreover, a treadmill submaximal stress test did not show any differences in exercise capacity between the two groups. In conclusion, the presence of a TAP does not significantly alter the late results or quality of life of patients who have undergone repair of TOF.

Adult↗
PubMed1996

Techniques for intrasplenic hepatocyte transplantation in the large animal model.

BACKGROUND: The preferred therapy for acute and chronic liver insufficiency and severe heritable disorders of liver metabolism is whole-organ transplantation. However, due to the shortage of organ donors and high cost, alternative therapeutic approaches have been proposed, including transplantation of normal allogeneic hepatocytes. Recently, it has been reported that many hepatocytes transplanted into the spleen migrated to the liver. We therefore carried out a series of large-animal experiments to reexamine the intrasplenic route and to develop a method for large-scale hepatocellular transplantation in pigs. METHODS: Allogeneic porcine hepatocytes were transplanted using the following routes: (1) retrograde injection of cells via the splenic vein, (2) intraarterial injection of cells, (3) direct intrasplenic injection of cells after laparotomy, (4) percutaneous intrasplenic injection of cells under laparoscopic control, (5) laparoscopic intrasplenic injection of cells. The number of cells injected varied from 2 x 10(9) to 10 x 10(9) cells. RESULTS: Of all the methods tested, only direct intrasplenic injection of 2 bln of cells was found to be compatible with survival. However, even with this "small" number of cells (2% original liver mass), there was a significant risk of spleen infarction, perisplenic adhesion formation, and portal vein thrombosis. The laparoscopic approach was found to be reliable, simple, and safe. CONCLUSION: Even though the spleen is considered by many authors the optimal site for hepatocellular transplantation, transplantation of cells in a number needed to support the failing liver may be associated with significant complications, morbidity, and mortality.

Animals↗
PubMed1996

Fringed valve prosthesis for aortic root abscess.

Two patients with aortic root abscess were successfully treated with a fringed valve prosthesis, in which a fringe material was secured to the sewing cuff of a bileaflet prosthetic valve using a 4-0 running suture. This fringed valve technique provides dual security for annular attachment of the prosthesis without coronary reimplantation. Good late outcome suggests it would be a useful alternative for aortic root abscess.

Abscess↗
PubMed1996

Histologic findings of long-term cryolesions in a patient with ventricular tachycardia.

This report describes cardiac morphologic alterations in a patient who died 14 months following cryoablation. Histologic examination of the long-term cryolesion revealed a homogeneous fibrous scar with surrounding sinusoid capillary proliferation. The border between the fibrosis and the normal myocardium was sharply defined. Cryothermia is an excellent technique for the surgical correction of arrhythmias because it provides sharply demarcated lesions which lack arrhythmogenic potential.

Bundle-Branch Block↗
PubMed1996

Long-term outcome of patients who received Starr-Edwards valves between 1965 and 1977.

To determine the risk factors relating to long-term outcomes of the Starr-Edwards ball valve, data from 150 patients (75 males, 75 females; age range 9-67 years); who underwent valve replacement (44 aortic, 106 mitral) between 1965 and 1977 at Niigata University were reviewed retrospectively. Valve models 6120/6320 and 1260/2320 were mainly used in mitral and aortic positions, respectively. The cumulative follow-up period was 2227.4 patient-years. Using the Kaplan-Meier life-table method, actuarial probability of freedom from valve-related mortality, morbidity and thromboembolism were analysed. Thirteen patients died from various causes during hospitalization. Some 80 patients suffered 97 instances of valve-related morbidity and 58 died during follow-up (up to 28 years). Patient age > 50 years affected the actuarial probability of freedom from valve-related mortality in the entire group (P < 0.05). Valve type and the year of operation were discriminative predictors of thromboembolic complications in the entire group (both P < 0.05) and in the mitral valve replacement group (P < 0.01 and P < 0.001). However, only the year of operation affected the actuarial probability of freedom from all valve-related morbidity in the entire group and in the mitral valve replacement group (both P < 0.05). Univariate analysis revealed that age at surgery, valve type, and the year of operation were related to late postoperative outcome in patients who received a Starr-Edwards ball valve between 1965 and 1977.

Actuarial Analysis↗
PubMed1996

A comparative study of the effect of autologous platelet-rich plasma and fresh autologous whole blood on haemostasis after cardiac surgery.

The effects of fresh autologous platelet-rich plasma and autologous whole blood on haemostasis after cardiopulmonary bypass were examined in adult cardiac surgery patients. Platelet count, adenosine diphosphate 10 microM maximum aggregation rate and clotting Factor VIII were greater in the platelet-rich plasma group (n = 11) than in the whole blood group (n = 8) after platelet-rich plasma or whole blood reinfusion. Blood loss after heparin neutralization was less in the platelet-rich plasma group than in the whole blood group. Blood loss from heparin neutralization to 12h after surgery was correlated with platelet count, fibrinogen and ADP aggregation rate. The number of patients who required homologous blood transfusion was less in the platelet-rich plasma group. In conclusion, the reinfusion of autologous platelet-rich plasma improves haemostasis after cardiopulmonary bypass, and may enable surgery to be performed without homologous blood transfusion.

Adenosine Diphosphate↗
PubMed1996

Is a bioprosthesis preferable in tricuspid valve replacement?

We reviewed clinical data on 29 patients (17 acquired disease and 12 congenital disease) who underwent tricuspid valve replacement using a Carpentier-Edwards porcine valve or a St. Jude Medical valve at Niigata University Hospital between January 1978 and October 1995, and analyzed risks related to the outcome. Age ranged from 8 to 62 years, and 17 females were included. New York Heart Association functional class was IV in 9 patients (31%). Previous valve surgery had been performed in 10 patients (34%). An urgent surgery was required in 4 patients and simultaneous mitral (with aortic) valve replacement in 13 (45%). Mean follow-up period was 6.7 years. Hospital mortality occurred in 5 patients (17.2%) and all of them had acquired valvular diseases with functional class IV. There were 6 late deaths and none of them related to the tricuspid prosthesis. Nonfatal morbidity occurred in 2 patients (a thrombosed valve and a chronic hemolytic anemia) with a St. Jude valve. Late functional class was I or II in all patients except 3 with severe left-ventricular dysfunction or bioprosthetic failure. Late postoperative echocardiographic examination showed moderate tricuspid stenosis or regurgitation in 3 patients with a Carpentier-Edwards valve. By the Kaplan-Meier method, functional class (P < 0.01) and baseline diseases (p < 0.05) were found to affect probability of freedom from cardiac- and/or valve-related mortality including hospital death. In conclusion, the present study indicates that similarly good outcome would be expected whether using a St. Jude Medical valve or a Carpentier-Edwards porcine valve, and that both functional class IV and combined acquired valvular disease are risk factors for mortality after tricuspid valve replacement. Patient-specific selection of the prosthesis would be preferable in tricuspid valve replacement.

Adolescent↗
PubMed1996

Angiotensin II type 2 receptor inhibits cell proliferation and activates tyrosine phosphatase.

The angiotensin II type 2 (AT2) receptor inhibits basic fibroblast growth factor-induced proliferation of R3T3 fibroblast cells and transiently stimulates a vanadate-sensitive phosphotyrosine phosphatase, strongly suggesting that AT2 is a mitogen inhibitor. We generated AT2 gene-null mice that showed increased blood pressure, indicating the hypotensive action of AT2. However, inhibition of renomedullary AT2 by selective antagonists, as reported by Sassard and associates, show that AT2 suppresses pressure natriuresis. Thus, both AT1 and AT2 work in the direction of sodium retention, suggesting a unique role for angiotensin II in the kidney in terms of blood pressure regulation and sodium metabolism.

Angiotensin II↗