Search PubMed⌕ Search

Biomedical subjects

T Seki

Publications and source records attributed to T Seki.

At least 505 records · Page 28Linked to original sources
PubMed1990

[A clinical study of associated bladder cancer in patients with renal pelvic and ureteral cancer].

We reviewed 76 cases of renal pelvic and ureteral cancer, admitted to our hospital between January, 1975 and December, 1988, with special reference to the occurrence of bladder cancer. Bladder cancer was associated with an upper urinary tract neoplasm in 35 of the 76 cases (46.1%), 7 with a preceding bladder cancer, 17 with a coexistent one and 11 with a subsequent one. In case of renal pelvic and upper ureteral cancer the incidence of coexistent or subsequent tumors of the bladder was 28.7% (16 of 56 patients). However, in the cases of lower ureteral cancer the incidence of these tumors was 82.4% (14 of 17 patients). This incidence was significantly higher than that in renal pelvic and upper ureteral cancer. The subsequent bladder cancer was observed in 19 patients including 8 patients who had a recurrence of the bladder cancer after the treatment for a preceding and coexistent bladder cancer. The cancer in most cases occurred within 2 years after the treatment of the upper urinary tract neoplasm. Of 19 patients who had subsequent bladder cancer 11 had primary sites in the renal pelvis and upper ureter. Another 8 patient had primary sites in the lower ureter. Four of the 8 subsequent bladder cancers in patients with lower ureteral cancer occurred just on and around the affected ureteral orifice. All these 4 tumors were high grade and high stage tumors. On the other hand, another 15 patients developed subsequent bladder cancer in a place other than the affected ureteral orifice. Of these 15 patients, 13 cases showed a low grade and low stage tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Clinical results, graft patency and flow reserve capacity of multiple coronary artery bypass with bilateral or sequential internal thoracic artery grafts].

Multiple coronary artery bypass grafting (CABG) was performed utilizing the internal thoracic arteries (ITA) in 87 patients ranging in age from 3 to 76 years. Bilateral ITAs were used in 67, sequential grafting was performed in 16, and the combination of both techniques was applied in 4 patients. Twelve patients had coronary arterial obstructions due to Kawasaki disease (mean age 9.7 +/- 3.3 years) and the remaining 75 patients had atherosclerotic coronary artery disease (mean age 53 +/- 10 years). Triple vessel disease and left main trunk disease occupied 85% of the patients. The number of grafts was 2 to 5 per patient with an average of 3.2 +/- 0.7 per patient. In bilateral ITA grafting, the combination of the RITA to LAD and LITA to LCX was most frequently used, and in sequential grafting, the LITA-diagonal artery-LAD was the most common use. There were no early or late mortalities in the present series. The patency rates for the RITA and LITA were 93% and 96%, respectively, and those of sequential grafting were 100% in both the proximal and distal anastomoses. The clinical outcome of multiple CABG with ITAs was quite satisfactory, and the bilateral ITAs could be used in the very wide range of patient's age from 3 to 76 years. In addition, blood flow reserve provided by bilateral ITAs was equivalent to that of the SVG alone or SVG plus ITA on the basis of the result of coronary sinus flow (CSF) measurements during exercise, and thus complete revascularization of the left ventricle could be accomplished by multiple CABG with ITAs.

Adult↗
PubMed1990

[Percutaneous balloon valvuloplasty of a stenosed bioprosthesis (Carpentier-Edwards xenograft) in the tricuspid valve position].

Two patients with increasing stenosis of a bioprosthesis in the tricuspid valve position were treated by percutaneous balloon valvuloplasty (PBV). Tricuspid valve replacement with a Carpentier-Edwards xenograft and mitral valve replacement with a Duromedics mechanical valve had been performed in both of them 2 to 3 years prior to PBV. Echocardiographic studies revealed tricuspid bioprosthetic stenosis with a prolonged pressure half time. After PBV, the calculated valve area and cardiac index increased and the pressure half time was shortened, although improvement of clinical symptoms was not apparent. Complications related to the procedure did not occur. Further studies are required to determine the indications and to see the long term results of PBV on stenosed bioprosthesis in the tricuspid valve position, but for the moment, we consider PBV be tried with caution for a stenosed bioprosthesis in the tricuspid valve position before the decision for re-replacement of the prosthesis.

Bioprosthesis↗
PubMed1990

Bilateral internal mammary artery grafts for coronary artery bypass operations in children.

We performed myocardial revascularization with bilateral internal mammary arteries in eight children for coronary artery complications consequent to Kawasaki disease. Subjects included seven boys and one girl, ranging in age from 3 to 13 years (mean age, 8.3 +/- 3.4 years). The body surface area ranged from 0.65 to 1.65 m2 (average, 1.08 +/- 0.35 m2). Three patients had a previous myocardial infarction. The right internal mammary artery was anastomosed to the right coronary artery and the left internal mammary artery was sutured to the left anterior descending artery in all patients. The patients received an average of 2.4 grafts. Magnifying loupes of 3.5 X were used for anastomosis with 8-0 monofilament polypropylene sutures. Subjects were followed up from 12 to 38 months (23 +/- 10.8 months) after operation. All were doing well with no recurrence of angina, and body development was normal, including the sternum and thorax according to chest x-ray films and computed tomography of the chest. Patency of the bilateral internal mammary arteries was 100% in the early (within 1 month) postoperative period and remained so in the late (over 1 year) postoperative period. Anastomotic junctions between the internal mammary artery and the coronary artery developed well angiographically in the late postoperative period. The internal mammary artery is the graft of choice for pediatric myocardial revascularization because of its excellent long-term patency and growth potential. Bilateral internal mammary arteries should be used whenever indicated, and the use of bilateral internal mammary arteries did not adversely influence chest wall development in the children.

Adolescent↗
PubMed1990

[Pre- and postoperative care of living relative patients for renal transplantation].

Between 1966 and 1989, 54 kidney transplants were performed at our institute. We present our experience about pre- and postoperative care of the patients for renal transplantation. 1) Donors 1) Pre- and postoperative function of the kidneys and urinary tract must be evaluated carefully. Renal transplantation can be done successfully if preoperative renal function is good even if the donor is older than 60 years old. 2) Preoperative evaluation of the donor renal artery is necessary. Four kidneys with renal artery anomalies and one kidney with renal artery aneurysm were used for renal transplantation uneventfully after they were repaired. 2) Recipients 1) We had 4 recipients who demonstrated abnormality of the urinary tract. They all received successful renal transplantation after appropriate urological management before renal transplantation. 2) Imaging diagnostic technique is useful when graft function is deteriorated. Acute rejection can be diagnosed more objectively using renal scintiscan and echogram. They are also useful for early detection of postoperative urological complications. In this paper, the diagnostic strategy using various imaging techniques was outlined.

Aged↗
PubMed1990

[Surgery of aortic valvular disease with congenital bicuspid or quadricuspid aortic valve].

Twelve patients (age 18 to 69 years old) with surgical treatment for congenital bicuspid aortic valve and one (age 26 years old) for quadricuspid aortic valve were reported. These 13 patients occupied 12.3% of the total number of patients with aortic valve replacement during the same period. Among the patients with bicuspid aortic valve, 10 patients were male (83%) and 2 were female (17%). Seven patients exhibited aortic stenosis and 5 showed predominant aortic regurgitation. The mean age of patients with aortic stenosis was higher than that of patients with aortic regurgitation. (63.3 years vs 32.0 years old). Infective endocarditis occurred in 2 patients (17%). Three patients had pure aortic regurgitation without evidence of endocarditis. One 26-year-old female patient who had a quadricuspid aortic valve presented with aortic regurgitation associated with PDA. All patients underwent aortic valve replacement with no early and late deaths.

Adult↗
PubMed1990

[A successful surgical case of aortic arch aneurysm associated with aortic regurgitation].

A 57-year-old male patient with aortic regurgitation and aneurysm of the ascending aorta and the aortic arch underwent aortic valve replacement and graft replacement from the ascending aorta to the aortic arch. The operation was done using cardio-pulmonary bypass and selective cerebral perfusion with deep hypothermia. Postoperative DSA revealed no dilatation of the sinus Valsalva and a good configuration of the anastomosis. It seems that selective cerebral perfusion with deep hypothermia is a safe method to prevent cerebral damage in a case of arch aneurysm.

Aorta↗
PubMed1989

Molecular cloning and expression of human hepatocyte growth factor.

Hepatocyte growth factor (HGF) is the most potent mitogen for mature parenchymal hepatocytes in primary culture, and seems to be a hepatotrophic factor that acts as a trigger for liver regeneration after partial hepatectomy and liver injury. The partial purification and characterization of HGF have been reported. We have demonstrated that pure HGF from rat platelets is a new growth factor effective at concentrations as low as 1 ng ml-1. The effects of HGF and epidermal growth factor (EGF) are additive. The activity of HGF is not species-specific, although it does not stimulate growth in Swiss 3T3 fibroblasts. HGF has a relative molecular mass (Mr) of 82,000 and is a heterodimer composed of a large alpha-subunit of Mr 69,000 and a small beta-subunit of Mr 34,000. Here we report the amino-acid sequence of human HGF determined by complementary DNA cloning and the expression of biologically active human HGF from COS-1 cells transfected with cloned cDNA. The nucleotide sequence of the human HGF cDNA reveals that both alpha- and beta-chains are contained in a single open reading frame coding for a pre-pro precursor protein of 728 amino acids.

Amino Acid Sequence↗
PubMed1989

Studies on bilokinase, a biliary plasminogen activator: immunologic property and organ distribution.

The aim of the present study was to elucidate the immunologic difference between bilokinase, a plasminogen activator in bile, and urokinase, an urinary plasminogen activator, and to demonstrate the organ distribution of these antigens. Polyclonal antibodies against the highly purified activators (bovine-bilokinase, -urokinase and human urokinase) were raised in rabbits or guinea pigs. Immunologic precipitin reactions and quenching were found to occur only between the activators and their respective antisera. Histo-immunologic demonstration of the activators revealed that bilokinase-antigen was localized mainly in the hepatocytes as well as in the mucosa of the gall bladder, whereas urokinase-antigen was present in the epithelium of the urinary tubules. The liver may have a potential role in the hepatobiliary fibrinolytic system.

Animals↗
PubMed1989

Development of Xenopus laevis skin glands producing 5-hydroxytryptamine and caerulein.

The granular glands in Xenopus laevis skin are known to contain large quantities of biogenic amines and bioactive peptides which closely resemble mammalian brain-gut peptides. We studied the development of glands producing 5-hydroxytryptamine (5-HT) and caerulein using immunohistochemistry, HPLC-fluorometric systems and RIA. The immunoreactivities of 5-HT and caerulein were first detected in the spherical gland rudiments in the stratum spongiosum at St. 58 (Nieuwkoop and Faber stage), or at the beginning of metamorphosis. Both immunoreactivities appeared in the same rudiment at the same time. Some of the gland rudiments have a small lumen filled with both immunoreactive materials at St. 58-59. During the rest of the metamorphic period, the glands grow in size, accumulating immunoreactive materials in the lumen. The concentrations of 5-HT and caerulein in the skin of tadpoles were below 1 ng per mg wet tissue at St. 58-59, increased as metamorphosis proceeded and reached 63 and 134 ng per mg wet tissue at St. 66, or at the end of metamorphosis, respectively. The amphibian granular glands where large quantities of biogenic amines and hormone-like peptides are rapidly synthesized may provide a useful model for the study of the development of amine- and peptide-producing cells including neurons and paraneurons.

Animals↗
PubMed1989

Identification of multiple isoforms of the low-affinity human IgG Fc receptor.

Two varieties of similar, but structurally distinct, cDNA clones for the human low-affinity receptors for the Fc portion of immunoglobulin G (Fc gamma RII) have been isolated. One type of clone was obtained from human B lymphocytes, and the other from PHA-activated peripheral T cells and monocytes. Transfection of both prototype clones into Cos-7 cells and subsequent specific staining with monoclonal antibodies of the CDw32 group confirmed the identification of the gene products. The nucleotide sequence of the cDNA clone from B lymphocytes contains an open reading frame that encodes a protein of relative mass (Mr) 27,000 with an extracellular domain of 179 amino acids containing three potential N-glycosylation sites, a 26 amino acid transmembrane domain, and a 44 amino acid cytoplasmic domain. The clones from peripheral T cells and monocytes both encoded a protein of Mr 31,000 with a 179 amino acid extracellular domain containing two potential N-glycosylation sites and a 26 amino acid transmembrane domain. The two types of clones had similar sequences in their immunoglobulin-like extracellular and transmembrane domain, but differed in their leader sequences and 3'untranslated regions. The most notable difference between the clones was the presence of a distinctive 76 amino acid cytoplasmic domain in those isolated from T cells and monocytes.

Amino Acid Sequence↗
PubMed1989

Different responses of coronary artery and internal mammary artery bypass grafts to ergonovine and nitroglycerin in variant angina.

The dynamic responses of a coronary artery and an internal mammary artery (IMA) graft to pharmacological intervention were examined by arteriography in 5 patients with variant angina who had undergone coronary artery bypass grafting with an in situ IMA to the left anterior descending coronary artery. Preoperative electrocardiographic findings included elevated ST segments in chest leads during attacks of angina, and all patients had severe fixed lesions in addition to marked spasm of the left anterior descending coronary artery after the administration of ergonovine maleate. Postoperatively with ergonovine stimulation, complete occlusion or marked subtotal narrowing was again observed at the primary fixed lesion in the proximal portion of the left anterior descending coronary artery, but the IMA graft and the coronary artery distal to the anastomotic site maintained satisfactory patency with no further occurrence of anginal pain or ST segment elevation. By computer-assisted graphic analysis, which allows highly reproducible measurements of vascular internal diameters, the diameter of the IMA showed only small changes under ergonovine (p = not significant) or nitroglycerin (p less than 0.05) stimulation in contrast to the marked vascular reactivity of the coronary artery (p less than 0.05 and less than 0.01, respectively). These findings indicate that the IMA graft is unresponsive to ergonovine at least in the amount required to produce coronary artery spasm in patients with variant angina and fixed lesions. The IMA graft appears to function well from a clinical and pharmacological viewpoint in patients with variant angina.

Adult↗
PubMed1989

DNA sequence analysis of the HLA-DRw12 allele.

The complete DNA sequence of a DR beta chain cDNA encoding the DRw12 allele has been determined. The sequence of this DRB1 allele reveals a structural relationship to the group of other DRB1 genes found on DRw52 haplotypes, such as DR3, -w11, -w13, -w14, and -w8. The structural similarities among this group of alleles are particularly evident in the first hypervariable as well as in the 3' untranslated region. The second hypervariable region contains a unique sequence not identified in any other DRB1 allele. The third hypervariable region appears to have arisen by gene conversion events involving two DRB1 chain genes, DR7 and DR1 or DR2/Dw21.

Alleles↗
PubMed1989

Clinical results and in vivo valve function after implantation of a Bicer valve prosthesis in the aortic position.

Between December 1981 and June 1987, 71 patients underwent aortic valve replacement with a Bicer monostrut tilting disc prosthesis. Clinical results and in vivo function of the artificial valve were assessed. The average age of the 71 patients at the time of operation was 51.3 +/- 11.5 years. The hospital mortality rate was 2.8% (two patients) and there were no further deaths during a mean (+/- SD) follow-up period of 2.4 +/- 1.6 years (range 1 month to 5.5 years) after surgery. There was also no occurrence of thromboembolism or valve dysfunction. Function of the Bicer valve prosthesis was assessed in 17 patients: 5 with a 21 mm valve, 7 with a 23 mm valve and 5 with a 25 mm valve. Examination was performed on average 10.3 +/- 8.1 months after surgery. Valve function was examined at rest and during exercise performed with a bicycle ergometer. Pressure gradients at rest were low: 21 mm valve = 8 mm Hg, 23 mm valve = 3 mm Hg and 25 mm valve = 2 mm Hg; the gradients during exercise were 11, 8 and 8 mm Hg, respectively. The valves had the following effective orifice area at rest: 21 mm valve = 1.54 cm2, 23 mm valve = 4.20 cm2 and 25 mm valve = 3.76 cm2; during exercise, the respective areas were 1.57, 3.48 and 3.01 cm2. These valves are deemed to be sufficiently wide for effective valve function. Aortographic observation indicated mild regurgitation that was within reasonable limits and posed no problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1989

Benign fibrous histiocytoma of the kidney.

A case of benign fibrous histiocytoma of the kidney in a 48-year-old man is reported. A 7-year followup has revealed no recurrence. To our knowledge there have been no previous reports of benign fibrous histiocytoma of the kidney.

Histiocytes↗
PubMed1989

Studies on 2',3'-dideoxy-2',3'-didehydropyrimidine nucleosides. II. N4-benzoyl-2',3'-dideoxy-2',3'-didehydrocytidine as a prodrug of 2',3'-dideoxy-2',3'-didehydrocytidine (DDCN).

N4-Benzoyl-2',3'-dideoxy-2',3'-didehydrocytidine (Bz-DDCN) was synthesized as a novel prodrug of 2',3'-dideoxy-2',3'-didehydrocytidine (DDCN), which is a reverse transcriptase inhibitor and is considered to be a potential anti-acquired immunodeficiency syndrome agent. Chemical and enzymatic regeneration of DDCN from the prodrug has been investigated in both in vitro and in vivo experiments. Bz-DDCN regenerated DDCN under basic conditions (greater than pH 8), while cleavage of the N-glycosidic linkage and production of N4-benzoylcytosine were observed under acidic conditions (less than pH 6). DDCN was enzymatically regenerated from the prodrug in the presence of several enzyme preparations, including human plasma. DDCN and Bz-DDCN were intravenously administered to mice and the plasma concentrations of DDCN and the prodrug were measured. Though DDCN levels following direct DDCN administration decreased exponentially with a half-life of 14.5 min, the plasma levels of DDCN following the prodrug administration were sustained above 2 microM for over 3 h.

Animals↗