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Biomedical subjects

Y Kitoh

Publications and source records attributed to Y Kitoh.

At least 37 records · Page 2Linked to original sources
PubMed1997

Huge aneurysm of the sinus of Valsalva following infective endocarditis in Behçet's disease.

A huge aneurysm of the sinus of Valsalva with conduction disturbance as a consequence of infective endocarditis in Behçet's disease is reported. The aneurysm extended not only into the ventricular septum but also to the right atrium and ventricle, with a complicated cavity formation. We speculate that complete atrioventricular block occurred due to an enlargement of the aneurysm into the ventricular septum, leading to a direct conduction system injury. Preoperative echocardiography and aortography were insufficient to recognize the extent of the lesion; subsequent operative examination revealed the true size. At operation, it is important to understand the lesion dimensions fully in order that appropriate surgical procedures be performed.

Aortic Aneurysm↗
PubMed1997

[A case report of total removal of infected pacemaker leads with cardiopulmonary bypass through right thoracotomy].

A 61-year-old man with septicemia had four infected pacemaker leads, which were impossible to remove using simple traction method. He received CABG previously, and SVG anastomosed to LAD was patent. Redo median sternotomy had a possibility to make damage to SVG. Total removal of infected pacemaker was performed successfully with cardiopulmonary bypass through right thoracotomy.

Cardiopulmonary Bypass↗
PubMed1996

Valve replacement with the CarboMedics bileaflet mechanical prosthesis: clinical results at midterm.

OBJECTIVE: We study the clinical midterm results of the valve replacement with the CarboMedics bileaflet mechanical prosthesis. EXPERIMENTAL DESIGN AND SETTING: Retrospective study. Institutional practice (National Cardiovascular Center, Osaka, Japan). PATIENTS AND INTERVENTIONS: 167 CarboMedics prostheses were implanted in 144 patients from April, 1990 and December, 1993. Of these, 77 patients underwent isolated aortic valve replacement (AVR), 45 patients underwent isolated mitral valve replacement (MVR), 21 patients underwent double (aortic and mitral) valve replacement (DVR), and one patient underwent triple (aortic, mitral and tricuspid) valve replacement (TVR). MEASURES: Events were defined in accordance with the guidelines for reporting morbidity and mortality after cardiac valve operations of the Society of Thoracic Surgeons/American Association for Thoracic Surgery.

Aortic Valve↗
PubMed1996

[Anticoagulant related hemorrhage and thromboembolism after valvular surgery].

We reviewed anticoagulant related hemorrhage (ACRH) and thromboembolism (TE) in 84 patients after valvular surgery. There were 45 females and 39 males with a mean age of 51.8 years (range 30.5-71.2 years), who underwent valvuloplasty in 14, bioprosthetic valve replacements in 17, mechanical valve replacements in 13. A mean period from the operation to the event were 2.7 years (range 0.01-12.3 years). There were 25 ACRH events after one valvuloplasty, 4 bioprosthetic valve replacements, 20 mechanical valve replacements. About half of them, the prothrombin time were less than 25%, which was considered the effect of warfarin is high, and 8% of them had infective endocarditis (IE) previously. There were 59 TE events after 13 valvuloplasties, 13 bioprosthetic valve replacements, 33 mechanical valve replacements. In the patients with atrial fibrillation, TE occurred irrespective of operative procedures. And in the patients with mechanical valve, severely impaired left ventricular function and past history of IE, thrombi of left ventricule were caused of TE. It was suggested that past history of IE was a risk factor ACRH and TE, and severely depressed left ventricular function and atrial fibrillation were for TE.

Adult↗
PubMed1995

Histologic modification by cryopreservation in rat aortic allografts.

Histologic changes after the cryopreserved rat aortic transplantation were studied, and the influences of the cryopreservation and of the allografting on the histology were examined. Four groups of Brown Norway (RT1n) and Lewis rats (RT1(1)) were used (n = 4 at each examined period in each group): the cryopreservation-allograft group (from Brown Norway to Lewis with cryopreservation), the cryopreservation-isograft group (from Lewis to Lewis with cryopreservation), the fresh allograft group (from Brown Norway to Lewis without cryopreservation), and the fresh isograft group (from Lewis to Lewis without cryopreservation). The graft was harvested from a descending thoracic aorta of a donor rat, implanted to an infrarenal abdominal aorta of a recipient rat, and extracted at 10 days, 1, 3, 6, and 12 months after the operation. The intimal thickening, cellular loss in the media, and cellular infiltration in the adventitia were observed, which were the same phenomena seen in chronic rejection of human organ allografts. Although the degree of intimal thickening and cellular loss in the media were higher in the cryopreserved groups than in the fresh groups, the cryopreservation procedure suppressed cellular infiltration in the adventitia after allotransplantation. The immunologic attack against the graft might be diminished by cryopreservation.

Animals↗
PubMed1995

Cell viability of aortic allografts after long-term cryopreservation and clinical application to aortic root replacement in a patient with aortitis.

A key point in the establishment of a tissue cryopreservation system is to maintain cell viability for an extended period. The viability of the tissue cells in the authors' cryopreservation system was examined, and the first clinical application reported. The tissue culture method demonstrated 95% of rat aortas (21 of 22 specimens) and 88% of human cardiac valves (seven of eight) to be viable after 6.4 months and 5.8 months of cryopreservation, respectively. The first clinical case, a 54-year-old man with aortic valve replacement and complications of aortitis, underwent successful aortic root replacement. Whereas the use of allografts in aortitis cases is controversial, such an approach was assumed reasonable because the mechanical stress between the native aortic annulus and the inserted valve could be reduced by aortic root replacement with the allograft.

Adult↗
PubMed1995

Surgical management of infective endocarditis associated with cerebral complications. Multi-center retrospective study in Japan.

To establish guidelines for the surgical treatment of patients with infective endocarditis who have cerebrovascular complications, we conducted a detailed retrospective study of 181 of 244 patients with cerebral complications among 2523 surgical cases of infective endocarditis of the Japanese Association of Thoracic Surgery. The results showed that 9.7% of all patients with infective endocarditis had associated cerebral complications: 108 (44.3%) had active native valve endocarditis, 96 (39.3%) had healed native valve endocarditis, and 40 (16.4%) had prosthetic valve endocarditis. The hospital mortality of the patients with cerebral complications was 11.0% in the group as a whole: 13.9% in active native valve endocarditis, 3.1% in healed native valve endocarditis, and 37.5% in prosthetic valve endocarditis. Diseased valves included the following aortic valve in 55.5%, mitral valve 49.8%, tricuspid valve in 1.3%, and pulmonary valve in 1.3%. In 181 patients with cerebral complications, organisms were detected as follows: gram-positive cocci in 133 (73.5% [Streptococcus in 85, Staphylococcus in 32]), gram-negative in 18 (9.9%), fungus in 11 (6.1%), and unknown in 64.6%, cerebral bleeding in 31.5%, cerebral abscess in 2.8%, and meningitis in 1.1%. Hospital mortality rate and an exacerbation rate of cerebral complications, including related death, according to the interval from onset of cerebral infarction to cardiac surgery, were as follows: 66.3% and 45.5% within 24 hours, 31.3% and 43.8% between 2 and 7 days, 16.7% and 16.7% between 8 and 14 days, 10.0% and 10.0% between 15 and 21 days, 26.3% and 10.5% between 22 and 28 days, and 7.0% and 2.3% over 4 weeks later, respectively. A significant correlation existed between the interval and the exacerbation of cerebral complications (tied p = 0.008). Preoperative risk factors affecting exacerbation of cerebral complications were as follows: (1) severity of cerebral complications (p = 0.006), (2) intervals (p = 0.012), and (3) uncontrolled congestive heart failure as indications for cardiac surgery (p = 0.014). One patient underwent a cardiac operation within 24 hours of the onset of cerebral hemorrhage and died of cerebral damage. No exacerbations occurred in 10 patients who underwent their operation between 2 and 28 days. Nevertheless, exacerbations occurred in 19.0% of patients whose operation was done more than 4 weeks later. These data suggest that cardiac operations can be done safely 4 weeks after cerebral infarction, and if the delay is more than 2 weeks, the exacerbation rate will be around 10%. The risk of progression of cerebral damage is still significant 15 days and even 4 weeks after cerebral hemorrhage.

Adult↗
PubMed1995

Histological change in cryopreserved rat aortic allograft.

In this study, we established an experimental cryopreserved aortic allograft model in rats and examined the long-term histological changes in the allograft. The thoracic aorta of Brown Norway rats (RT1n) was cryopreserved with 10% dimethylsulfoxide using a programmable freezer, and was allo-transplanted to the infrarenal abdominal aorta of Lewis rats (RT1l). Neither immunosuppressants nor anticoagulants were administered postoperatively. As a control, isografting was also performed between Lewis donor and recipient rats. In the allograft groups, cellular infiltration in the adventitia was massive at the acute phase after the operation and decreased gradually. Intimal thickening was predominantly observed from the early stage, followed by advancing thickening. In the media, decrease in cell number was detected after 1 month, and chondrocyte-like-cells were observed around which calcification was noted. Endothelial cells were observed in only one-third of the recipient investigated at 10 days and in over 80% of those at 12 months. In the isograft groups, a low grade of intimal thickening was detected over the experimental period. No decrease in cell number in the media was detected, and the degree of cellular infiltration in the adventitia was mild. After allotransplantation of the cryopreserved rat aorta, intimal thickening, medial necrosis and cellular infiltration in the adventitia, all the manifestations of rejection, occurred. Thus, as the cryopreserved tissue induces an immunological response, it is important to match the blood type and/or histocompatibility in clinical use.

Animals↗
PubMed1994

[Development of a new delayed healing model of an open skin wound and effects of M-1011G (ointment gauze containing 5% lysozyme hydrochloride) on the model].

We tried to develop a new delayed healing model of an open wound made on the dorsal skin of a rat by inducing malnutrition with restriction of food intake. We determined the effects of a newly introduced ointment gauze containing 5% lysozyme hydrochloride (M-1011G) on this model. Malnutrition characterized by a decrease in body weight and serum protein was produced by restricting the daily intake of commercially available food to 6 g for 2 weeks without liver disturbance and thereafter maintained with food intake of 12 g/day. Under these conditions, healing of the open wound made on the dorsal skin was prolonged, as compared with that of the wound made on a well-nourished animal. In this model, statistical studies showed that M-1011G was the most effective in accelerating the reduction of the wound area and shortening of the time required for the complete healing, among the following treatments: sterilized gauze alone, ointment gauze alone and 5% lysozyme hydrochloride-containing emulsified ointment. Histological findings showed that M-1011G greatly accelerated the granulation of this tissue which is essential for wound healing, probably due to stimulation of epidermization and regenerated granulation in the wound.

Animals↗
PubMed1994

Amplification of selected exons by polymerase chain reaction enables determination of the translational reading frame of dystrophin mRNA resulting from deletion mutations.

Duchenne and Becker muscular dystrophies (DMD and BMD) are severe and mild phenotypes, respectively, of the mutated dystrophin gene. Based on the frameshift theory, an out-of-frame deletion causes DMD, while an in-frame deletion causes BMD. Amplification of deletion-prone exons by polymerase chain reaction (PCR) has been used for the screening of deletion mutations of the dystrophin gene. However, it is difficult to determine the resulting translational reading frame in deleted cases by amplification of the deletion-prone exons. To determine the resulting translational reading frame, we employed a method which selectively amplifies exons affecting the following translational reading frame. Using this method, thirty-three DMD/BMD patients with a deletion mutation in the central region of the dystrophin gene were examined. Twenty-seven of 29 DMD patients had out-of-frame deletions, while only two had in-frame deletions. All four BMD patients had in-frame deletions. Therefore, 93.9% patients fitted the frameshift theory. This method is very useful for clinical diagnosis because of its precision and convenience.

Base Sequence↗
PubMed1994

Comparison of repair techniques for mitral valve prolapse.

Between January 1978 and September 1992, 127 patients with isolated mitral regurgitation due to prolapse underwent mitral valve reconstruction. There were 74 men and 53 women whose mean age was 49.7 years, ranging from 16 to 74 years. Follow up was 99.2% complete and totaled 483.0 patient-years (mean: 3.8 years). One hundred and forty-eight procedures were carried out to repair the prolapses using four types of techniques: (1) leaflet plication in 97 patients; (2) artificial chordal replacement with polytetrafluoroethylene sutures in 30 patients; (3) chordal shortening in 16 patients; and (4) commissural imbrication in five patients. In order to repair the annular dilation, commissural plications were done in 75 and ring prostheses were implanted in 15 patients. There were one hospital and eight late deaths. One (cerebral infarction) of all deaths was related to the reconstructed mitral valve. There were 14 reoperations (11.0%) for recurrent mitral incompetence with a freedom from reoperation of 89.0% at five, and 81.1% at 10 years. There were four cases of thromboembolism (one fatal, three non-fatal) with freedom from thromboembolism of 96.7% at five, and 93.3% at 10 years. No endocarditis or hemorrhagic complications were noted. Linearized incidence of recurrent mitral regurgitation according to repair technique for the prolapse was 1.44%/pty in the leaflet plication series, 1.45%/pty with chordal replacement, 4.37%/pty after chordal shortening and 8.67%/pty following commissural imbrication. The linearized rate of failure in annuloplasty was 2.91%/pty after commissural plication and 1.74%/pty after ring annuloplasty. Statistically significant difference was confirmed only between leaflet plication and chordal shortening.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

A novel point mutation (G-1 to T) in a 5' splice donor site of intron 13 of the dystrophin gene results in exon skipping and is responsible for Becker muscular dystrophy.

The mutations in one-third of Duchenne and Becker muscular dystrophy patients remain unknown, as they do not involve gross rearrangements of the dystrophin gene. We now report a defect in the splicing of precursor mRNA (pre-mRNA), resulting from a maternally inherited mutation of the dystrophin gene in a patient with Becker muscular dystrophy. This defect results from a G-to-T transversion at the terminal nucleotide of exon 13, within the 5' splice site of intron 13, and causes complete skipping of exon 13 during processing of dystrophin pre-mRNA. The predicted polypeptide encoded by the aberrant mRNA is a truncated dystrophin lacking 40 amino acids from the amino-proximal end of the rod domain. This is the first report of an intraexon point mutation that completely inactivates a 5' splice donor site in dystrophin pre-mRNA. Analysis of the genomic context of the G-1-to-T mutation at the 5' splice site supports the exon-definition model of pre-mRNA splicing and contributes to the understanding of splice-site selection.

Adult↗
PubMed1993

Brain- and muscle-type promoters of the dystrophin gene are selected in peripheral lymphocytes and Epstein Barr virus-transformed lymphoblastoid [correction of lymphoplastoid] cells.

Promoter-specific transcripts of the dystrophin gene in peripheral lymphocytes and Epstein Barr virus-transformed lymphoblastoid cells were analysed using reverse transcription-nested polymerase chain reaction. Two DNA fragments, corresponding to the alternative first exons transcribed from either brain- or muscle-type promoters, were both amplified from cDNA prepared from normal lymphocytes and lymphoblastoid cells. The nucleotide sequences of the amplified products were 100% homologous to the 5' termini of the cDNA of brain- and muscle-type dystrophins, respectively. Neither fragment was amplified from the lymphoblastoid cells of a patient with Duchenne muscular dystrophy, who has a partial deletion involving the brain- and muscle-type promoters in the dystrophin gene. These findings showed that the brain-type as well as the muscle-type promoter of the dystrophin gene was active in lymphocytes and lymphoblastoid cells.

B-Lymphocytes↗