Biomedical subjects

E Sugawara

Publications and source records attributed to E Sugawara.

At least 19 recordsLinked to original sources

PubMed2000

[Delayed sternal closure after open heart surgery in neonates and early infants].

Between November 1992 and February 1996, 84 patients (less than 3 months of age) underwent open heart surgery. Among 76 patients except 8 who required mechanical circulatory support, the sternum was left open. The indication of open sternotomy was hypoplastic left heart syndrome in 14 patients and unstable hemodynamics in 4 patients. Three patients died before delayed sternal closure. Delayed sternal closure was carried out in 15 patients with a mean of 4.7 days postoperatively. By the time of sternal closure, blood pressure, left atrial pressure and respiratory parameters improved and inotropics were reduced with the minus fluid balance. One patient died of sepsis 4 days after delayed sternal closure. Delayed sternal closure was effective modality to neonates or early infants after complex open heart surgery.

Cardiac Surgical Procedures↗

PubMed1999

Effect of media constituents on the formation by halophilic yeast of the 2 (or 5)-ethyl-5 (or 2)-methyl-4-hydroxy-3 (2H)-furanone aroma component specific to miso.

The formation of HEMF [2 (or 5)-ethyl-5 (or 2)-methyl-4-hydroxy-3 (2H)-furanone] by yeast was examined in an attempt to investigate its mechanism and involved factors. HEMF formation was promoted by yeast cultivation in a heat-sterilized medium which included glucose, ribose, and a nitrogenous compound such as an extract of shoyu koji, poly-peptone, casamino acid, or an amino acid (glutamic acid, threonine, serine, or alanine).

Culture Media↗

PubMed1998

Biochemistry and regulation of a novel Escherichia coli K-12 porin protein, OmpG, which produces unusually large channels.

A novel porin, OmpG, is produced in response to a chromosomal mutation termed cog-192. Molecular characterization of cog-192 revealed that it is a large chromosomal deletion extending from the 3' end of pspA through to the 5' end of an open reading frame located immediately upstream of ompG. As a result of this 13.1-kb deletion, the expression of ompG was placed under the control of the pspA promoter. Characterization of OmpG revealed that it is quite different from other porins. Proteoliposome swelling assays showed that OmpG channels were much larger than those of the OmpF and OmpC porins, with an estimated limited diameter of about 2 nm. The channel lacked any obvious solute specificity. The folding model of OmpG suggests that it is the first 16-stranded beta-barrel porin that lacks the large external loop, L3, which constricts the channels of other nonspecific and specific porins. Consistent with the folding model, circular dichroism showed that OmpG contains largely a beta-sheet structure. In contrast to other Escherichia coli porins, there is no evidence that OmpG exists as stable oligomers. Although ompG DNA was present in all E. coli strains examined so far, its expression under laboratory conditions was seen only due to rare chromosomal mutations. Curiously, OmpG was constitutively expressed, albeit at low levels, in Salmonella, Shigella, and Pseudomonas species.

Amino Acid Sequence↗

PubMed1998

A possible role of nitric oxide formation in the vasodilatation of rabbit ear artery induced by a topically applied Capsaicin analogue.

Effects of topical application of a capsaicin analogue, nonylic acid vanillylamide (NVA, 0.032-10.0 mM) on the arterial diameter in the ear skin were examined in conscious rabbits using a precise dial caliper. In addition, the possibility of nitric oxide (NO) participating in a vasodilatation induced by low concentrations of NVA was tested by an NO synthase inhibitor. At the lowest concentration of NVA (0.032 mM), no significant change in the diameter was observed after external application of the NVA ointment. At concentrations of 0.32 mM or more, NVA produced a significant vasodilator response. However, at higher concentrations of 3.2 and 10.0 mM, -NVA induced substantial shrinkage in the arterial diameter and oedema formation, which was not affected by L-NAME (NG-nitro-L-arginine methyl ester, 3 mg/kg, i.v.), suggesting fluid leakage induced by oedema from the vessels might suppress the vasodilatation. Thus, the concentration-response curve for NVA was bell-shaped. NVA (0.32 mM)-induced vasodilatation was not significantly affected by atropine (1 mg/kg, i.v.) or propranolol (80 micrograms/kg, i.v.). However, the NVA-induced vasodilatation was completely suppressed by an NO synthase inhibitor, L-NAME (3 mg/kg, i.v.) which had no influence on the resting diameter, but not by an inactive stereoisomer, D-NAME (3 mg/kg, i.v.). These findings suggest that vanilloid receptor activation results in the release of sensory neuropeptides, which in turn stimulate the synthesis of endothelial NO which is responsible for the vasodilatation.

Administration, Topical↗

PubMed1998

Neonatal intrathymic splenocyte injection yields prolonged cardiac xenograft survival.

Intrathymic (i.t.) injection of allogenic cells without administration of anti-lymphocyte serum (ALS) in neonatal recipients has induced donor-specific tolerance to subsequent cardiac allografts in rats. This study examines whether similar tactics can be successfully applied to a hamster-to-rat cardiac xenotransplantation model. Lewis neonates on their first day of life underwent i.t., subcutaneous (s.c.), intraperitoneal (i.p.), or intravenous (i.v.) injections of 5 x 10(7) Golden Syrian hamster splenocytes. After six weeks, the rats underwent heterotopic cardiac transplantation of hamster hearts. Cyclophosphamide (CyP) was administered on the day before surgery and postoperatively to suppress antibody-mediated graft rejection. Rats given splenocytes with 80 mg/kg of CyP had the following graft survival times: 8 to 12 days for i.t. injection (mean, 9.4 days); 5 to 7 days for s.c. injection (mean, 6.6 days); 4 to 11 days for i.p. injection (mean, 7.4 days); and 4 to 13 days for i.v. injection (mean, 7.9 days). Only the extension of graft survival produced by i.t. injection was statistically significant in comparison with the rats given only CyP treatment (mean, 7.5 days; P < 0.05). Thus, it appears that i.t. injection of xenogenic splenocytes in neonatal recipients with administration of CyP, but without ALS, can prolong xenograft survival. This biological intervention may be most useful in pediatric xenotransplantation when combined with other immunomodulation techniques.

Animals↗

PubMed1997

Ischemic and reperfusion injury of cyanotic myocardium in chronic hypoxic rat model: changes in cyanotic myocardial antioxidant system.

OBJECTIVE: The objective was to evaluate the effect of left ventricular function on cyanotic myocardium after ischemia-reperfusion and to determine the effect of cyanosis on the myocardial antioxidant system. METHODS: Cyanotic hearts (cyanotic group) were obtained from rats housed in a hypoxic chamber (10% oxygen) for 2 weeks and control hearts (control group) from rats maintained in ambient air. Isolated, crystalloid perfused working hearts were subjected to 15 minutes of global normothermic ischemia and 20 minutes of reperfusion, and functional recovery was evaluated in the two groups. Myocardial superoxide dismutase, glutathione peroxidase, glutathione reductase activity, and reduced glutathione content were measured separately in the cytoplasm and mitochondria at the end of the preischemic, ischemic, and reperfusion periods. RESULTS: Mean cardiac output/left ventricular weight was not significantly different between the two groups. Percent recovery of cardiac output was significantly lower in the cyanotic group than in the control group (56.1% +/- 5.7% vs 73.0% +/- 3.1%, p = 0.001). Mitochondrial superoxide dismutase, mitochondrial and cytosolic glutathione reductase activity, and cytosolic reduced glutathione were significantly lower in the cyanotic group than in the control group at end-ischemia (superoxide dismutase, 3.7 +/- 1.3 vs 5.9 +/- 1.5 units/mg protein, p = 0.012; mitochondrial glutathione reductase, 43.7 +/- 14.0 vs 71.0 +/- 30.3 munits/mg protein, p = 0.039; cytosolic glutathione reductase, 13.7 +/- 2.0 vs 23.2 +/- 4.2 munits/mg protein, p < 0.001; and reduced glutathione, 0.69 +/- 0.10 vs 0.91 +/- 0.24 microgram/mg protein, p = 0.037). CONCLUSIONS: Cyanosis impairs postischemic functional recovery and depresses myocardial antioxidant reserve during ischemia. Reduced antioxidant reserve at end-ischemia may result in impaired postischemic functional recovery of cyanotic myocardium.

Animals↗

PubMed1997

[Successful open commissurotomy and resection of dysplastic myxomatous tissue on the leaflet edges in a neonate and an early infant with critical aortic stenosis].

A neonate and an early infant with critical aortic stenosis successfully underwent open commissurotomy and resection of dysplastic myxomatous tissue on the leaflet edges using cardiopulmonary bypass. Case 1: A 31-day-old boy admitted to our unit with shock. Echocardiography demonstrated critical aortic stenosis and severe left ventricular dysfunction (EF = 15%). Case 2: A 12-day-old boy suddenly deteriorated and required resuscitation with ventilation and inotropic support. Emergency operation was required in both cases using cardiopulmonary bypass with systemic hypothermia (30 degrees C). In both cases, the aortic valve was bicuspid and dysplastic with gelatinous myxomatous tissue on the leaflet edges. Commissurotomy and resection of myxomatous tissue were performed. Their postoperation courses were uneventful and they have been free from medication at present. These results suggest that aortic commissurotomy and resection of myxomatous tissue under direct vision may be preferable for critical aortic stenosis with dysplastic aortic valve.

Aortic Valve↗

PubMed1997

[A successful retraining of the left ventricle with a left ventricular assist device (bio-medicus) after the arterial switch operation].

We experienced the case of a patient with d-TGA, small VSD who underwent arterial switch operation (ASO) at the age of 8 weeks. In pre-operative UCG, the LV posterior wall thickness was only 3.0 mm. LV systolic pressure had dropped to 29 mmHg at the time of operation. After arterial switch and VSD closure, myocardial contractility and coronary perfusion were good without any ST-T changes, however, the patient could not be weaned from cardiopulmonary bypass. Left ventricular assist device (LVAD) was then applied and LV training was performed with appropriate pre and after-load. On the 4th operative day, the patient was successfully weaned from LVAD. Training of the left ventricle with LVAD will be a useful life-saving method in the case of left ventricular failure after arterial switch operation.

Cardiac Surgical Procedures↗

PubMed1997

[Transverse submammary skin incision for congenital cardiac surgery].

Submammary skin incision has been accepted as cosmetic approach for open heart surgery. During November 1990 to February 1995, 39 ASD patients under 15 years old were operated with either median or submammary skin incision in Okayama University Medical School. For these patients, retrospective study was carried out to determine whether submammary skin incision made surgical procedure complex and whether patients were satisfied with the scar by submammary skin incision. There were 14 submammary skin incision (Group S) and 25 median skin incision (Group M). There was no significant difference in patients profile between the two groups except for sex. Operative time, cardiopulmonary bypass time and aortic cross clamp time had no significant difference between the two groups. Postoperative ICU stay and hospital stay also did not differed between the two groups. Questionnaires for evaluation of the subjective operation scar was sent with 32 answers (82%). There was no significant difference on questionnaire findings. However for the patients without hypertrophic scar, more patients in Group S were significantly satisfied with their scars. Submammary skin incision was safe and easy. It could be alternative of median skin incision. If hypertrophic scar formation could be prevented, more patients would be satisfied with submammary skin incision than median skin incision.

Cardiac Surgical Procedures↗

PubMed1996

Participation of endodermal epithelial cells on the synthesis of plasma LDL and HDL in the chick yolk sac.

We ultrastructually examined the chick yolk sac endodermal epithelium and evaluated our findings in combination with the biochemical analysis of serum and yolk lipoproteins. Twenty-five to 30 nm-sized particles were demonstrated to be a principal element of the extracellular yolk mass and these were determined to be yolk very low density lipoprotein (VLDL). The particles were shown to be taken up by the epithelial cells via coated pits and engulfed by plasma membrane invaginations together with yolk subdroplets, another element of the yolk mass. Through apical vacuoles, the two yolk elements were incorporated into yolk drops, which were identified to be one of the lysosomal structures by a cytochemical procedure using acid phosphatase (AcP)ase activity. During the last week of incubation, which is the final third of the incubation period, the digestion seemed to progress rapidly in the yolk drops, which came to resemble lipolysosomes; lipoprotein production became active as expressed by an enlarged Golgi apparatus. The newly produced lipoprotein particles were electron-lucent and irregular in size (50-120 nm). They were sequestered in secretory vacuoles and secreted from the vascular surface of the epithelial cells. Finally, the particles were thought to be taken into the vitelline circulation as plasma lipoproteins. The major component of lipoprotein in serum was determined to be low density lipoprotein (LDL) and high density lipoprotein (HDL), while cholesterol content was found to increase during incubation. We concluded that endodermal epithelial cells participate the synthesis of plasma LDL and HDL. For this synthesis the cells probably apply lipids and apo-protein generated from yolk VLDL degradation.

Acid Phosphatase↗

PubMed1996

Late aneurysm after subclavian flap aortoplasty for coarctation of the aorta.

Late aneurysms are common after repair of coarctation of the aorta by prosthetic patch aortoplasty but are rare after subclavian flap aortoplasty. We present the case of a 14-year-old boy who underwent a grafting procedure for a descending thoracic aortic aneurysm after subclavian flap aortoplasty for coarctation of the aorta when he was 2 years old. This is the fifth report of late aneurysm formation after subclavian flap aortoplasty.

Adolescent↗

PubMed1996

Secondary structure of the outer membrane proteins OmpA of Escherichia coli and OprF of Pseudomonas aeruginosa.

When purified without the use of ionic detergents, both OmpA and OprF proteins contained nearly 20% alpha-helical structures, which disappeared completely upon the addition of sodium dodecyl sulfate. This result suggests that the proteins fold in a similar manner, with an N-terminal, membrane-spanning beta-barrel domain and a C-terminal, globular, periplasmic domain.

Bacterial Outer Membrane Proteins↗

PubMed1995

[A surgical repair of partial anomalous pulmonary venous drainage to the high superior vena cava].

A 7-year-old boy with partial anomalous pulmonary venous drainage to the high superior vena cava (SVC) underwent surgical repair by Williams procedure. Right upper pulmonary vein was drained to the left atrium via the SVC and the surgically enlarged sinus venosus type ASD. SVC was ligated and divided. SVC was then anastomosed to RA appendage pedicle directly. Autologous pericardium was patched anteriorly to create a new SVC pathway. The postoperative course was uneventful without arrhythmia and cardiac catheterization 1 month postoperation revealed no stenosis of the SVC and right upper pulmonary venous return.

Anastomosis, Surgical↗

PubMed1994

OmpA protein of Escherichia coli outer membrane occurs in open and closed channel forms.

OmpA protein of Escherichia coli outer membrane can produce diffusion channels when reconstituted into proteoliposomes (Sugawara, E., and Nikaido, H. (1992) J. Biol. Chem. 267, 2507-2511). The pore size is similar to that of the classical E. coli porins OmpF and OmpC, but the penetration rates of small solutes through the OmpA channel are about 50 times slower than that through the OmpF channel. Here we examined the possibility that only a small fraction of the OmpA molecules produces open channels. Unilamellar proteoliposomes were made so that each vesicle contained only a small number of OmpA molecules. These vesicles, containing 0.3 M urea within, were fractionated on a linear iso-osmolar density gradient made of urea and sucrose. This resulted in the clear separation of vesicles not containing any open channel, staying on top of the gradient, from those containing at least one open channel, sedimenting close to the bottom. Calculation using Poisson distribution indicated that only between 2 and 3% of the OmpA molecules contained open channel. The open form is estimated to allow the diffusion of L-arabinose at a rate comparable with that through the OmpF porin channel. The open and closed states were relatively stable properties of the protein. Denaturation of open form OmpA and its subsequent renaturation converted it into a nonfunctional or closed form, suggesting that the open and closed forms represent two alternative conformers of this protein.

Bacterial Outer Membrane Proteins↗

PubMed1994

Formation and accumulation of lipolysosomes in developing chick hepatocytes.

Formation and accumulation of lipolysosomes in developing chick hepatocytes were investigated by means of electron microscopy in combination with biochemical analyses of the lipid composition in liver homogenates. The lipolysosomes occurred with highest frequency from days 11 to 14 of incubation. They were usually small and electron-dense, but during development they gradually enlarged with an accompanying reduction in electron density. Coinciding with this enlargement was an accumulation of esterified cholesterol in the liver homogenates. After hatching, an immediate decrease in the size and number of lipolysosomes occurred along with a reduction in the concentration of esterified cholesterol, of which only a very small amount remained by 9 days of age. Instead of cholesterol, triglycerides subsequently increased in concentration and accounted for the major lipid content of the liver homogenates. In keeping with the ultrastructural changes, the total volume of cytoplasmic lipid droplets rapidly increased with increasing age. This transient accumulation of esterified cholesterol within lipolysosomes may be attributed to an excessive uptake and processing of plasma lipoprotein particles, probably derived from the egg yolk. This concept is supported by an abundance of coated pits, endosomes and multivesicular bodies in the embryonic hepatocytes.

Animals↗

PubMed1994

[Surgical treatment of pulmonary aspergillosis].

There is controversy about the optimal treatment for pulmonary aspergillosis. Eight patients with pulmonary aspergilloma underwent surgical treatment. Three patients had tuberculosis, one Sjögren syndrome, one aortitis syndrome, one malignant lymphoma. Lobectomy was performed in five patients, segmentectomy in three patients. All patients are alive and have no recurrence. We have obtained excellent results from surgery and advocate early surgery for localized lesions to prevent life-threatening hemoptysis. This will allow patients to continue with further treatment for the underlying disease. We encountered a granulocytopenic patient with rapidly progressive aspergillus infection resulting in occlusion of main pulmonary artery leading to death. Surgical intervention could not prevent this fatal outcome. The selection of the patients with diffuse lesions should be made carefully.

Adult↗

PubMed1994

[Late progression of pulmonary hypertension in a patient operated for patent ductus arteriosus: pulmonary angiopathy or thromboembolism?].

A 16-year-old girl developed dyspnea 9 years after surgery for patent ductus arteriosus with pulmonary hypertension (pulmonary to systemic peak systolic pressure ratio; Pp/Ps 1.0). The postoperative course had been uneventful with a decreased Pp/Ps. It was revealed this time, however, that the pulmonary arterial pressure again elevated to be 186/133 mmHg (Pp/Ps 1.90). Postoperative progression of pulmonary angiopathy was first suspected. Whereas, the findings with pulmonary perfusion scintigraphy and arteriography were remarkably different between the right and left lungs, suggesting that the progression of pulmonary hypertension was not caused by that of pulmonary angiopathy but by the association of thromboembolism in small pulmonary arteries. The patient succumbed to intractable cardiopulmonary failure, strongly appealing for the necessity of organ-transplantation therapy in Japan. This case also indicated the particular importance of a close follow-up of the cases with pulmonary hypertension remaining after corrective surgery.

Adolescent↗

PubMed1993

Circulatory support for patients experiencing postcardiotomy cardiogenic shock: analysis of risk factors for death and long-term follow-up.

Over the last 5 years, 12 patients received ventricular assist devices (VADs) while in postcardiotomy cardiogenic shock. There were 7 male and 5 female patients ranging in age from 22 to 73 years (average age, 54). Eight patients underwent surgery for valve replacements, 3 for coronary artery bypass graftings, and 1 for closure of a ventricular septal rupture. The duration of VAD support ranged from 6 h to 9 days (mean, 4.2 days). Ten patients were weaned from the VADs, and 6 survived. Univariate analysis indicated that renal failure, infection, and heart failure had a negative impact on those patients who survived. Multivariate analysis indicated that heart failure, renal failure, and preoperative left ventricular ejection fraction were the most important predictors of hospital death. The 6 survivors were followed for 4 to 42 months (mean, 25 months); 5 were in New York Heart Association (NYHA) Class I, and 1 was in Class II. The cardiac functions in 5 patients who lived over 1 year were assessed by echocardiography. Preoperative and postoperative UCG revealed that ejection fraction and mean velocity of circumferential fiber shortening increased significantly (p < 0.01). Also, the left ventricular diastolic and systolic dimensions decreased significantly (p < 0.05). However, the patients did not show further changes in these parameters during exercise. Eight patients who had double valve replacements were observed for comparison (control group). In the control group, exercise improved cardiac output and mean velocity of circumferential fiber shortening (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Surgical Procedures↗