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Biomedical subjects

Y Shimazaki

Publications and source records attributed to Y Shimazaki.

At least 55 records · Page 3Linked to original sources
PubMed1999

Removal of cartilage rings of the graft and omentopexy for extended tracheal autotransplantation.

BACKGROUND: One of the serious problems in longer-size tracheal transplantation is infection or severe stenosis of the graft, probably caused by an inadequate blood supply even with omentopexy. For obtaining an appropriate blood supply, we experimentally developed a new technique that included removal of some cartilage rings of the graft and omentopexy. METHODS: Twenty-one adult mongrel dogs were used. In group A (n = 11), a nine-cartilage ring length of the trachea in which six of nine rings were removed, leaving one cartilage ring at each end of the graft and another in the center, was autotransplanted with omentopexy. Two artificial tracheal rings outside the graft were used for maintaining the lumen. In group B (n = 10), a nine-cartilage ring length of the trachea was autotransplanted with omentopexy. RESULTS: In group A, all dogs survived until being sacrificed, whereas 5 group B dogs died of graft infection and mediastinitis (p<0.05 versus group A). Mucosal blood flow of the graft in group A was normal and higher than in group B (p<0.05). Grade of the graft stenosis at death or sacrifice was 14%+/-1% in group A and 58%+/-25% in group B (p<0.05). CONCLUSIONS: Removal of some cartilage rings improved blood supply to the graft and resulted in satisfactory survival and nonsignificant tracheal stenosis in extended tracheal autotransplantation.

Animals↗
PubMed1999

Optimal blood flow for cooled brain at 20 degrees C.

BACKGROUND: Optimal conditions for deep hypothermic perfusion and protective brain blood flow remain unclear. METHODS: Dogs (n = 52) underwent 120 minutes of cardiopulmonary bypass at 20 degrees C with perfusion flow rates of 2.5, 5, 10, 20, 40, and 100 mL x kg(-1) x min(-1). We examined the effect of the various flow rates and different perfusion pressures on brain blood flow, metabolism, and intracellular pH. RESULTS: The brain was ischemic and acidotic when the perfusion flow rate was less than 5 mL kg(-1) x min(-1) and pressure was less than 10 mm Hg. When perfusion pressure was higher than 10 mm Hg, cerebral cortex blood flow was more than 9 mL x 100 g(-1) x min(-1) and intracellular pH, higher than 6.95. The cerebral metabolic rate for oxygen decreased at a flow rate of 2.5 mL x kg(-1) min(-1). The cerebral metabolic ratio of glucose to oxygen and the cerebral vascular resistance were lowest when perfusion pressure was 10 to 30 mm Hg. Full-flow (100 mL x kg(-1) x min(-1)) perfusion caused paradoxical brain acidosis; a flow of 40 mL x kg(-1) x min(-1) provided the best results. CONCLUSIONS: Both extremely low-flow perfusion and excessive perfusion cause brain acidosis. Low-flow perfusion at a pressure of 20 mm Hg provides cerebral vasorelaxation and aerobic metabolism during operations at 20 degrees C.

Animals↗
PubMed1999

Detection of suction and regurgitation of the implantable centrifugal pump based on the motor current waveform analysis and its application to optimization of pump flow.

In this study, a detection algorithm for suction and regurgitation of the centrifugal pump during left heart bypass without relying on external flow or pressure sensors was developed and evaluated in acute studies using adult goats. The detection scheme relies on power spectral density (PSD) analysis of the motor current waveform through which the waveform deformation index (WDI) is obtained. This index is defined as the ratio of the fundamental component of the PSD to the higher PSD components, and its value increases with the deformation of the basic waveform. By assuming that the undistorted motor current waveform can be represented by a pure sine waveform, we theoretically synthesized various waveforms which have different second harmonic components. We were able to synthesize the waveform whose shape was close to the distorted motor current waveform under varying suction levels obtained in a mock loop study. From this study, we came to the conclusion that the WDI value of 0.2 can serve as a threshold level in deciding the suction and regurgitation speeds (rpm) during left heart bypass. In the study using adult goats, we were successful in minimizing both regurgitation and suction when the centrifugal pump speed was adjusted based on the WDI algorithm. The resultant bypass flow ranged from 1.5 to 2.0 L/min which was around 60% of the total flow. Further study is underway to evaluate the applicability of the WDI method in optimizing bypass pump flow.

Algorithms↗
PubMed1999

Bovine milk antibodies against cell surface protein antigen PAc-glucosyltransferase fusion protein suppress cell adhesion and alter glucan synthesis of Streptococcus mutans.

Cell surface protein antigen (PAc) and glucosyltransferases (GTF) produced by Streptococcus mutans are considered major colonization factors of the organism, and the inhibition of these factors is thought to prevent dental caries. In this study, 8-mo-old pregnant Holstein cows were immunized with fusion protein PAcA-GB, a fusion of the saliva-binding alanine-rich region (PAcA) of PAc with the glucan binding (GB) domain of GTF-I, an enzyme catalyzing the synthesis of water-insoluble glucan from sucrose. High titers of immunoglobulin antibodies specific for the fusion protein were found in normal milk after reimmunization, and they persisted for approximately 3 mo. The immunoglobulin G (IgG) antibodies against PAcA-GB were purified from immunized milk. The antibodies significantly inhibited the adhesion of S. mutans cells to saliva-coated hydroxyapatite beads. IgG antibodies purified from immunized milk also inhibited total glucan synthesis by cell-associated GTF preparation and GTF-I from S. mutans. The immunized milk may be useful as a means of passive immunization for the prevention of dental caries in humans.

Animals↗
PubMed1999

Effects of Duraflo II heparin-coated cardiopulmonary bypass circuits on the coagulation system, endothelial damage, and cytokine release in patients with cardiac operation employing aprotinin and steroids.

The effects of Duraflo II heparin coated cardiopulmonary bypass circuits, low-dose aprotinin, and steroids on the coagulation system, endothelial damage, and cytokine release were evaluated by comparing those treated with low-dose aprotinin and steroids. Twenty-four adult patients undergoing coronary artery bypass grafting, aortic valve replacement, or valve repair surgery were randomly assigned to 2 groups: either heparin-coated (Duraflo group, n = 12) or noncoated equipment (noncoated group, n = 12) groups. In the Duraflo group, the cardiopulmonary reservoir was also coated with heparin. There were no significant differences in age at the time of operation, aortic cross-clamp time, cardiopulmonary bypass time, and rectal temperature during cardiopulmonary bypass. Standard systemic heparinization was performed. Methylpredonisolone and low-dose aprotinin were given in both groups of patients. Serum XIIa factor, TAT, and IL-6 were significantly higher in the control group than in the Duraflo group during cardiopulmonary bypass (p < 0.01). Serum IL-8 was significantly higher in the control group than in the Duraflo group at 24 h after cardiopulmonary bypass (p < 0.05). No significant difference was found in serum thrombomodulin and TNF-alpha; both were within normal during the study period. These results indicate that the use of Duraflo II heparin coated equipment and a heparin-coated cardiopulmonary reservoir suppressed excess coagulation and inflammatory reaction induced by cardiopulmonary bypass.

Aged↗
PubMed1999

Recombination between gtfB and gtfC is required for survival of a dTDP-rhamnose synthesis-deficient mutant of Streptococcus mutans in the presence of sucrose.

The rml genes are involved in dTDP-rhamnose synthesis in Streptococcus mutans. A gene fusion between gtfB and gtfC, which both encode extracellular water-insoluble glucan-synthesizing enzymes, accompanied by inactivation of the rml genes was observed for cells grown in the presence of sucrose. The survival rates of rml mutants isolated in the absence of sucrose were drastically reduced in the presence of sucrose. The rates were consistent with the frequency of spontaneous gene fusions between gtfB and gtfC, suggesting that the spontaneous recombinant organisms were selected in the presence of sucrose. The rml mutants with a gtfB-gtfC fusion gene had markedly reduced water-insoluble glucan synthetic activity and lost the ability to colonize glass surfaces in the presence of sucrose. These results suggest that the rml mutants of S. mutans, which are defective in dTDP-rhamnose synthesis, can survive only in the absence of water-insoluble glucan synthesis.

Gene Expression Regulation, Bacterial↗
PubMed1999

[Results of muscle flap repair for deep mediastinitis and graft patency after coronary artery bypass grafting].

Between 1978 and 1997, 9 patients developed poststernotomy mediastinitis after coronary artery bypass grafting. Four of these patients (group A) were treated with open drainage and mediastinal irrigation or omental transfer. The other 5 patients (group B) were treated with primary wound closure by the technique of muscle flap mobilization. The purpose of this study was to compare the surgical results and graft patency of both groups. The hospital mortality of group A was 100 per cent. All patients in group B survived for 35 months of the mean postoperative periods without complaints. Postoperative coronary angiography revealed the complete graft patency in group B. We conclude that muscle flap mobilization may be a superior measure for the patient survival and graft patency as the treatment of mediastinitis after coronary artery bypass grafting.

Aged↗
PubMed1999

Copper(I) Complexes with a Proximal Aromatic Ring: Novel Copper-Indole Bonding.

A unique bonding of indole to a metal ion has been established. Two new tridentate N ligands with a pendent indole ring gave Cu(I) complexes 1 and 2, the latter of which exhibits the new form of bonding between the Cu(I) ion in a distorted tetrahedral geometry and the indole C(2)-C(3) moiety. The bond is dependent upon the length of the side chain and therefore the accessibility of the ring to the metal center.

Journal Article↗
PubMed1999

[A case of lung cancer (small cell carcinoma) occurring esophago-pericardial fistula and purulent pericarditis].

A 72-year-old woman who had had an endoscopic sclerotherapy for esophageal varices presented with high fever and severe cough. Chest X-ray and CT demonstrated a pneumopericardium and pericardial effusion. Esophagoscopy and esophagography revealed an esophageal perforation into the pericardial cavity and into the lung. Consequently, drainage and irrigation of the pericardial cavity and mediastinum were done for MRSA infection. However, these procedures failed to reduce the inflammation, and she expired because of liver failure soon after placing a covered stent in the esophagus. Postmortem examination revealed small cell carcinoma in the left lung invading into the esophagus and pericardium.

Aged↗
PubMed1998

Removal of specific protein spots on the patterns of non-denaturing two-dimensional electrophoresis using protein A agarose and antibodies.

Protein spots, such as immunoglobulin G (IgG), A (IgA) or alpha 2-macroglobulin, on the patterns of non-denaturing two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) were selectively removed by the application of protein A or antibody-conjugated protein A agarose to the first-dimension gel top at the cathode side. A protein residing at pI 5.8 and with a molecular mass of about 200 kDa was clearly detected when the IgG and IgA spots were removed from the 2-D PAGE pattern.

Antibodies↗
PubMed1998

Different effect of diastereoisomers of L-cystathionine sulfoxide on the stimulus coupled responses of human neutrophils.

The priming effect of L-cystathionine sulfoxide, which is one of the unusual cystathionine metabolites found in the urine of patients with cystathioninuria, on the stimulus-induced superoxide generation by human neutrophils was examined. The synthetic L-cystathionine sulfoxide significantly enhanced the superoxide generations induced by N-formyl-methionyl-leucyl-phenylalanine [fMLP], opsonized zymosan [OZ], arachidonic acid [AA], and phorbol 12-myristate 13-acetate [PMA]. Then the synthetic L-cystathionine sulfoxide was separated into two diastereoisomers, CS-I and CS-II, which showed a peak at 76 and 83 min on chromatogram by amino acid analyzer, respectively. CS-I enhanced the superoxide generations induced by AA and PMA but not those induced by fMLP and OZ. On the contrary, CS-II enhanced the superoxide generations induced by fMLP and OZ but not those induced by AA and PMA. The superoxide generation induced by PMA with CS-I was suppressed by H-7 and was enhanced by genistein, while that by fMLP with CS-II was suppressed by genistein and was enhanced by H-7.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1998

[Use of ultrasonically activated scalpel for the paced patient--a case report].

A paced patient underwent mitral valve replacement for mitral stenosis using ultrasonically activated scalpel. There were minimum bleeding and no homologous blood transfusion was required. Ultrasonically activated scalpel fid not interfere the pulse generator nor the transesophageal echocardiography. Ultrasonically activated scalpel is useful for the open heart surgery in paced patients.

Cardiac Pacing, Artificial↗
PubMed1998

[Congenital bronchial atresia complicated with severe cough--a case report].

A 37-year-old woman presented severe cough for several years. Chest X-ray showed an abnormal shadow in the right upper lung field. That was absent but hyperlucent before onset. Chest CT scan revealed a mass shadow with mucoid impaction in the right S2. Thoracoscopic right upper lobectomy dramatically improved her complaints. Histological examination revealed the dilated bronchus containing mucoid impaction and confirmed a diagnosis of congenital bronchial atresia. It was suggested that organizing pneumonia resulting from repeated infection caused severe cough. Thoracoscopic surgery for congenital bronchial atresia should be recommended in young patients.

Adult↗
PubMed1998

Heterotopic pancreas of the esophagus associated with a rare type of esophageal atresia.

An infant with a rare type of esophageal/tracheal anomaly associated with heterotopic pancreas of the esophagus is herein reported. The upper pouch containing heterotopic pancreas reached 1.5 cm below the tracheal carina, and the distal esophagus connected to the trachea 2 cm above the tracheal carina and thus formed a partial duplication of the esophagus. Heterotopic pancreas of the esophagus is extremely rare, with only 7 cases previously reported. Here we report the combination of heterotopic pancreas and esophageal atresia with tracheoesophageal fistula.

Anastomosis, Surgical↗
PubMed1998

Aprotinin reduces the expression of p-selectin on the surface of platelet and leukocyte-platelet conjugates.

P-Selectin, an adhesion molecule expressed on the surfaces of activated platelets and the vascular endothelium, mediates platelet binding to monocytes and neutrophils. Monocytes and neutrophils produce superoxide anion by activated platelets through p-selectin. Aprotinin, a serine protease inhibitor, inhibits plasmin to activate platelets during cardiopulmonary bypass (CPB). A total of 25 patients were studied to clarify the effects of aprotinin on p-selectin expression during CPB. Nine patients were not given aprotinin (control group), and 16 were given aprotinin of 2 million U in the priming solution (aprotinin group). The platelet count and soluble p-selectin in the plasma, p-selectin on the surface membranes of platelets, and leukocyte-platelet conjugate levels were measured during and after CPB. The platelet count was maintained well in the aprotinin group. The increases of soluble p-selectin in the plasma, platelet surface p-selectin, and leukocyte-platelet conjugates were less in the aprotinin group than in the control group (p < 0.05). In conclusion, aprotinin in patients undergoing CPB may reduce the early inflammatory reactions induced by p-selectin.

Aprotinin↗