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Biomedical subjects

S Suehiro

Publications and source records attributed to S Suehiro.

At least 55 records · Page 3Linked to original sources
PubMed1998

[Operative results of composite aortic root replacement by a Svensson's method].

The results of reconstruction of the aortic root performed on 9 patients by Svensson's method were examined. Nine subjects comprised 6 men and 3 women aged 23-69 years. In the preoperative diagnosis, annulo-aortic ectasia (AAE) was found in 7 cases, acute Type A aortic dissection in 1 case and AAE accompanied by chronic dissection after AVR in 1 case. Every patient underwent reconstruction by direct implantation of the right coronary artery button and interposition grafting for the left coronary artery, using a composite valve graft made of SJM valve and collagen coating artificial graft. Although one patient was lost due to multiple cerebral infarction, no marked changes were observed in other 8 patients. Angiography at short-term after operation showed no problems in the composite valve graft, and revealed good coronary arterial flow. Now, 2-62 months after operation (41 months on average), no late death occurred. On angiography of 2 cases performed after a long-term period, patency of the interposition graft was excellent. The early and late results of aortic root reconstruction by Svensson's method appeared favorable.

Adult↗
PubMed1998

[Successful repair of tricuspid regurgitation due to blunt trauma].

A 19-year-old man developed paralysis of the left arm as a result of left brachial plexus injury by a traffic accident. He underwent operation for the brachial plexus paralysis, and then severe heart failure developed postoperatively. Echocardiography revealed severe tricuspid valve regurgitation. Tricuspid valve plasty was performed 14 months after the traffic accident. The anterior leaflet of the tricuspid valve was torn and the chordae attached there were torn as well. The torn anterior leaflet was sutured directly, and the prolapsed portion of this leaflet was collected by transfer of the elongated chordae. Annuloplasty (DeVega technique) was then added. Postoperative echocardiography revealed trivial regurgitation of the tricuspid valve. Only 9 cases of successful repair of traumatic tricuspid regurgitation have been reported in Japan.

Accidents, Traffic↗
PubMed1998

[Influence of left ventricular wall thickening on myocardial injury in aortic valve replacement].

We retrospectively examined the influence of left ventricular wall thickening on myocardial injury in aortic valve replacement. Thirty-five patients who underwent aortic valve replacement in our hospital between January 1995 and July 1997 were studied. We divided these patients into 3 groups: group N (left ventricular thickness (LVT) < or = 10 mm), group H (10 < LVT < or = 15 mm), and group S (LVT > 15 mm). All patients of group S had aortic stenosis. CK and CK-MB were significantly higher and the cardiac index was significantly lower in group S than in the other groups. Intra-aortic balloon pumping was required for 50% of patients in group S, and a total dose of catecholamine above 10 micrograms/kg/min was also required for 50% of patients in this group. In the other groups, these percentages were significantly lower. Myocardial protection and postoperative care were difficult for patients with severe left ventricular hypertrophy with LVT over 15 mm in this study. Left ventricular wall thickness was a more important factor in determining difficulty with intraoperative myocardial protection than was left ventricular mass.

Adolescent↗
PubMed1997

Highly selective aldose reductase inhibitors. 3. Structural diversity of 3-(arylmethyl)-2,4,5-trioxoimidazolidine-1-acetic acids.

Accumulation of intracellular sorbitol, the reduced product of glucose, catalyzed by aldose reductase (AR) (EC 1.1.1.21), is thought to be the cause of the development of diabetic complications. Our attention is focused on finding compounds which inhibit AR without significantly inhibiting aldehyde reductase (ALR) (EC 1.1.1.2). The uracil or 2,4-dioxoimidazolidine skeleton having the benzothiazolyl or 4-chloro-3-nitrophenyl group as an aryl part indicated not only extremely high AR inhibitory activity but also AR selectivity. The ratio of IC50(ALR)/IC50(AR) of 3-[(5-chlorobenzothiazol-2-yl)methyl]-1,2,3,4-tetrahydro-2,4- dioxopyrimidine-1-acetic acid (47d) was more than 17 500. The uracil skeleton with the benzothiazolyl moiety seemed to be the best combination for selective AR inhibition.

Acetates↗
PubMed1997

Effects of protease inhibitors on postischemic recovery of the heart.

It is well known that activation of proteases in the lysosomes and cytosol is one of the mechanisms of ischemic injury. It might thus be beneficial to determine whether the addition of several clinically available protease inhibitors to a cardioplegic solution can improve its protective ability. Using an isolated working rat heart preparation, the effects of several protease inhibitors (serine protease inhibitors; nafamostat mesilate and gabexate mesilate, a thiol-protease inhibitor; NCO-700; and a urinary trypsin inhibitor, urinastatin) on the postischemic recovery of function and enzyme leakage were investigated in this study. These protease inhibitors were added to either the cardioplegic solution or reperfusion solution. The addition of each of the protease inhibitors, except urinastatin, to the cardioplegic solution improved the postischemic recovery of function and reduced enzyme leakage. The dose-response characteristics of these three protease inhibitors were bell shaped, and the optimal concentrations of nafamostat mesilate, gabexate mesilate, and NCO-700 were 5 microM, 100 microM, and 20 microM, respectively. In contrast to the results of the preischemic treatment study, the addition of any of the protease inhibitors to the perfusion medium during Langendorff reperfusion failed to improve the postischemic recovery of function and to reduce enzyme leakage. Surprisingly, the addition of NCO-700 to the reperfusion solution at a concentration of 5 microM or higher had rather harmful effects on both functional recovery and enzyme leakage. These findings suggest that serine and thiol proteases may play an important role in myocardial injury during ischemia, but not necessarily during reperfusion.

Animals↗
PubMed1997

A comparative analysis of the murine thymic microenvironment in normal, autoimmune, and immunodeficiency states.

It is widely accepted that the thymic microenvironment regulates normal thymopoiesis through a highly coordinated and complex series of cellular and cytokine interactions. A direct corollary of this is that abnormalities within the microenvironment could be of etiologic significance in T-cell-based diseases. Our laboratory has developed a large panel of monoclonal antibodies (mAbs) that react specifically with epithelial or nonepithelial markers in the thymus. We have taken advantage of these reagents to characterize the thymic microenvironment of several genetic strains of mice, including BALB/cJ, C57BL/6J, NZB/BlnJ, SM/J, NOD/Ltz, NOD/Ltz-scid/sz, C57BL/6J-Hcphme/Hcphme, and ALY/NscJcl-aly/aly mice, and littermate control animals. We report herein that control mice, including strains of several backgrounds, have a very consistent phenotypic profile with this panel of monoclonal antibodies, including reactivity with thymic epithelial cells in the cortex, the medulla and the corticomedullary junction, and the extracellular matrix. In contrast, the disease-prone strains studied have unique, abnormal staining of thymic cortex and medulla at both the structural and cellular levels. These phenotypic data suggest that abnormalities in interactions between developing thymocytes and stromal cells characterize disease-prone mice.

Animals↗
PubMed1997

Highly selective aldose reductase inhibitors. II. Optimization of the aryl part of 3-(arylmethyl)-2,4,5-trioxoimidazolidine-1-acetic acids.

Accumulation of intracellular sorbitol, the product of glucose reduction catalyzed by aldose reductase (AR) [EC 1.1.1.21], is thought to be the main culprit in the development of diabetic complications. A series of 3-arylalkyl-2,4,5-trioxoimidazolidine-1-acetic acids was prepared and tested for inhibitory activities towards AR and aldehyde reductase (ALR) [EC 1.1.1.2]. These derivatives showed strong inhibitory activity against AR without markedly inhibiting ALR. In particular, the compounds with 3-nitrophenyl, 4-chloro-3-nitrophenyl, and chloro-substituted benzothiazolyl groups as the aryl part showed powerful AR-inhibitory activity. The chloro-substituted benzothiazolyl compound showed an AR selectivity of more than 5,000 fold.

Aldehyde Reductase↗
PubMed1997

[A surgical case of vascular ring (Edwards IIIB) with dysphagia evaluated by esophageal scintigraphy].

Severe esophageal compression due to a vascular ring rarely develops after childhood. We report a case of a 35-year-old man with dysphagia associated with a vascular ring. Radionuclide transit studies were performed before and after surgery for quantitative evaluation of deglutition. Preoperative aortogram disclosed a right sided aortic arch and a retroesophageal left subclavian artery arising from a diverticulum of the arch. Because of the severity of his symptoms, he was taken to surgery. He underwent posterolateral thoracotomy through the fourth intercostal space and division of the ligamentum arteriosum. The esophagus was mobilized from the aortic arch, the arch diverticulum, the pulmonary artery, and the trachea. Postoperatively, he experienced immediate resolution of dysphagia and quickly began eating a regular diet. Although a postoperative esophagogram revealed the esophageal compression, esophageal scintigraphy using 185 MBq 99mTc pertechnetate revealed shortening of the transit time of swallowed water by 1.0 second after surgery. Quantitative evaluation of deglutition in the esophagus by scintigraphy was useful for this patient, since he suffered from psychiatric problems.

Adult↗
PubMed1997

[Clinical and echocardiographic evaluation of the Medtronic-Hall 20A valve in the aortic position in patients with small aortic annulus: comparison with the 21 mmSJM valve].

We compared the results of Medtronic-Hall 20A aortic valve (MH20A) replacement with those of 21 mm SJM valve (SJM21A) replacement. The subjects were 17 patients who underwent aortic valve replacement with MH20A. The mean age was 65.4 +/- 8.8 years in the MH20A group. The average body surface area in the MH20A group was 1.37 +/- 0.08 m2, which was significantly smaller than in the SJM21A group (1.55 +/- 0.09 m2). The postoperative follow-up period was 51 months at maximum and 20 months on average. There was one hospital death and two late deaths in the MH20A group. The other patients were categorized NYHA I classification. The trans-valvular peak pressure gradient soon after surgery was 21 +/- 9.3 mmHg in the MH20A group, and 23.9 +/- 8.8 mmHg in the SJM21A group. Preoperative and late postoperative echocardiograms demonstrated significant decrease in mean left ventricular end-diastolic diameter and left ventricular end-systolic diameter in the both groups. Mean left ventricular hypertrophy was decreased to 22.8 +/- 4.6 mm from 25.0 +/- 3.9 mm in the MH20A group, and 24.1 +/- 4.3 mm from 28.5 +/- 5.6 mm in the SJM21A group. These data suggest that aortic valve replacement with MH20A is useful for patients who have smaller body surface area (< 1.50 m2) with a small aortic annulus.

Aged↗
PubMed1997

[A case of isolated tricuspid valve endocarditis caused by Campylobacter fetus].

We reported a rare case of isolated tricuspid valve endocarditis in a non-addict with no underlying cardiac disease. A 48-year-old man was presented with high fever and newly developed leg edema. The diagnosis of tricuspid endocarditis was established following detection of a large vegetation (3.0 cm) on the tricuspid valve on echocardiography. One blood culture showed positive for Campylobacter fetus. At operation, a large and a small vegetation were found attached to the anterior leaflet of the tricuspid valve, and the septal leaflet was also found to be involved by the infective endocarditis. These leaflets were therefore removed and the tricuspid valve was replaced with CarboMedics valve. He has remained free of endocarditis for nineteen months after surgery.

Campylobacter Infections↗
PubMed1996

Dynamic Small-Angle X-ray Scattering System using an Imaging Plate.

A synchrotron-radiation dynamic small-angle X-ray scattering (Synchrotron Radiation-DSAXS) system using an imaging plate has been developed at the Photon Factory, National Laboratory for High Energy Physics, Japan, in collaboration with the Department of Polymer Chemistry, Kyoto University, Japan, for studying the dynamic response of mesoscopic structures in polymers to applied mechanical stimuli. Small-angle X-ray scattering patterns of 100 x 100 mm(2) have been successively recorded on a 400 x 200 mm(2) stage-mounted imaging plate with a minimum time interval of 0.5 s. X-ray data are simultaneously obtained with stress and strain measurements on specimens subjected to a mechanical deformation. The performance of the DSAXS system is demonstrated along with some experimental results concerning the dynamic deformation of a b.c.c. lattice with paracrystalline distortion in a co-polymer having spherical microdomains under a large oscillatory shear deformation.

Journal Article↗
PubMed1996

Echocardiography-guided pericardiocentesis with a needle attached to a probe.

Pericardiocentesis with a needle attached to a probe was performed under two-dimensional echocardiographic guidance in 9 patients with pericardial effusion after cardiac operations. The first 5 mm of the tip of a puncture needle for percutaneous transhepatic cholangiodrainage is scratched with a scalpel to give the tip high echo intensity. When the probe is placed on the skin, the direction of puncture at that probe angle appears automatically on the monitor.

Drainage↗
PubMed1996

A new assay system detecting antibody production and delayed-type hypersensitivity responses to trinitrophenyl hapten in an individual mouse.

A new assay system detecting antibody production and delayed-type hypersensitivity (DTH) responses to trinitrophenyl hapten in an individual mouse (AS-DAD) was established. BALB/c mice were immunized intraperitoneally with varying amounts of 2,4,6-trinitrophenylated sheep red blood cells (TNP-SRBC) on day 0. Venous blood was collected on days 2, 4, 6, 8 and 10. Levels of anti-TNP IgM and IgG serum were assayed by enzyme-linked immunosorbent assay (ELISA). After series of bleeding the mice were challenged with 2,4,6-trinitrobenzene sulfonic acid (TNBS) solution in the footpad on day 14. Footpad swelling was measured 24 or 48 h after the challenge. Peak responses of the anti-TNP IgM and IgG production were detected 4 or 6 days after the immunization with 10(9) TNP-SRBC. Maximum DTH response was also observed with 10(9) TNP-SRBC 24 h after the challenge on day 14. The antibody and DTH responses were also induced in other normal inbred strains such as C3H/He and DBA/1 but not BALB/c nu/nu mice. To evaluate AS-DAD in immunopharmacological studies, various immunomodulating agents were examined in BALB/c mice by subcutaneous administration on days 0, 1, 2 and 3. Cyclosporin or cyclophosphamide at 100 mg/kg/day completely inhibited not only the anti-TNP IgM and IgG production but also the TNP-specific DTH response. Prednisolone at 0.5 mg/kg/day had no significant effect on the IgM and IgG production, whereas it inhibited the TNP-specific DTH response. Interestingly, histamine-added mouse gamma-globulin at 150 MG/kg/day clearly enhanced the anti-TNP IgM and IgG production, while it showed a suppressive effect on the TNP-specific DTH response. Levamisole at 5.0 mg/KG/day showed suppressive effects on the anti-TNP IgG production without affecting the IgM production and the DTH response. These results suggest that AS-DAD is useful for evaluating the immunopharmacological action of various agents.

Animals↗
PubMed1996

The murine thymic microenvironment: changes with age.

Immunosenescence has been well described in both human and a variety of animal species and has an important influence on changes in immune function. Although several mechanisms may be operating to explain the alterations in immune function with age, one factor that has attracted significant attention has been the progressive age-dependent involution of the thymus. Hitherto, most studies of thymus have focused only on thymocytes. We have now taken advantage of a well-defined panel of monoclonal antibodies (mAbs called MTS) that recognize and characterize the thymic miroenvironment, including epithelial and nonepithelial elements. Recent data using these MTS mAbs have disclosed significant abnormalities in the thymic cortex in models of murine lupus including the unusual appearance of medullary-type epithelial cells in the cortical areas and the presence of epithelial free spaces or 'cortical holes'. In this study, we investigated age-related changes in the thymic microenvironment in 12-month-old C3H/HeJ, C57BL/6 and BALB/c mice. Controls included thymus from young 4-to 6-week-old mice as well as 6-month-old BALB/c mice. As expected, the thymus of all 12-month-old mice manifested normal and distinctive separation of cortical and medullary epithelium. However, unlike younger mice, the 12-month-old mice had severe changes in these regions. For example, in older mice, the cortex and medulla were diffusely irregular and atrophic and had a poorly defined cortico medullary junction; the former having small disrupted epithelial networks, and the latter containing clusters of atrophic cells. Moreover, the extracellular matrix was increased and contained large irregularly shaped clusters. Interestingly, the thymus of 6-month-old mice expressed some changes within the medullary epithelium and the extracellular matrix, but the cortical epithelium remained unchanged. These age-related degenerative changes in the thymic microenvironment differ significantly from the abnormalities identified in autoimmunity and may be a factor in immunosenescence.

Aging↗
PubMed1996

[Late pericardial effusion after open-heart surgery: usefulness of pericardiocentesis under echocardiographic guidance].

Late pericardial effusion (PE) after open heart surgery has a potential for serious complications, including tamponade necessitating urgent drainage. From October 1990 to March 1995 moderate to massive PE developed following 9 of 359 (2.5%) cardiac procedures between 11 and 55 days postoperatively (mean, 18.6 days). Only one of these nine patients had evidence of cardiac tamponade; the other 8 patients had moderate symptoms including malaise, weight gain, and dyspnea on exertion. All patients except one were being treated with warfarin and anti-platelet agents. Echocardiography detected posterior PE of variable magnitude in all 9 patients; anterior PE was present in only one of these patients. Pericardiocentesis under echocardiographic guidance using an echo transducer with a built in puncture needle was performed in all patients. A flexible catheter was left in place for 24 to 72 hours for suction. In each case, 300 to 712 ml of old bloody fluid (mean, 475 ml) was evacuated, with relief of symptoms. Despite continuing anticoagulant therapy, there was no recurrence of pericardial effusion. The technique we have described simplifies pericardiocentesis and helps to avoid complications in this procedure.

Adult↗
PubMed1996

[Successful surgical treatment for fungal endocarditis involving the aortic valve: report of a case].

A 50-year-old man who had undergone successful aortic valve replacement for fungal endocarditis was presented. He had been doing well until October 1993, when he suddenly developed shock with high fever. In two weeks he recovered from septic shock with vigorous medical treatment including intravenous administration of antibiotics. The infecting organism was not detected on repeated blood cultures. Four months later he was admitted to our hospital because of left heart failure. Although he was afebrile on admission, a two dimensional echocardiogram revealed vegetation on the aortic valve and massive aortic regurgitation. Inflammatory signs persisted and the vegetation increased in size, and therefore an aortic valve replacement was performed. A surgical specimen of the aortic valve revealed perforation in each of three cusps and vegetation on the non-coronary cusp. Pathological exploration revealed typical colonies of fungi. Following the diagnosis of fungal endocarditis, administration of an anti-fungal drug was started. His post-operative course was uneventful, and there was no evidence of recurrence with the anti-fungal medication for one year postoperatively.

Antifungal Agents↗