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Biomedical subjects

T Koyanagi

Publications and source records attributed to T Koyanagi.

At least 163 records · Page 9Linked to original sources
PubMed1995

[A case report of prosthetic valve replacement for malfunction of the Hancock valve in mitral position associated with recurrent peptic ulcer and renal dysfunction].

A 62-year-old woman was admitted with malfunction of the Hancock valve in mitral position. She had been suffering from gastroduodenal ulcer for about ten years. She couldn't take warfarin after 5 years later of the initial operation due to recurrent gastrointestinal bleeding. Judging from her age and renal dysfunction, we preferred mechanical valve to avoid the risks for the reoperation. After confirming the healed ulcer with administering omeprazole, we performed prosthetic valve replacement with SJM 29 M successfully. Postoperative course was uneventful and recurrence of the ulcer was not observed.

Female↗
PubMed1995

Nephron sparing surgery for renal cell carcinoma in von Hippel-Lindau disease.

PURPOSE: We evaluated the technical feasibility and followup outcomes of a nephron sparing operation for localized renal cell carcinoma and von Hippel-Lindau disease. MATERIALS AND METHODS: Our 5 patients underwent initial nephron sparing surgery followed by serial computerized tomography. RESULTS: All but 1 renal lesion was resected in 9 initial nephron sparing operations. Postoperative computerized tomography revealed 35 lesions of which 8 had enlarged. Four patients underwent secondary renal surgery and adequate renal function was preserved. CONCLUSIONS: Even with the high risk of local recurrence nephron sparing surgery is an appropriate approach for these patients.

Adult↗
PubMed1995

Effect of 15-deoxyspergualin (DSG) on rat kidney allograft: immunological mechanisms implicated in prolonged survival.

PURPOSE AND METHODS: The effect of short-term administration of 15-deoxyspergualin (DSG), 5 mg./kg./day from postoperative days 4 to 7, on rat renal transplantation was studied. RESULTS: Although allografts treated with DSG survived longer than nontreated ones, cellular infiltration in both grafts did not differ. However, renal tubular cells of DSG-treated grafts proliferated well and escaped apoptotic cell death. A donor-specific tolerance 2 weeks after transplantation was developed, and cells with in vitro suppressor function were induced in such animals. CONCLUSIONS: Treatment with DSG appears to prevent lethal attack of effector cells on tubular cells in situ and to generate suppressor cells in the maintenance phase of graft enhancement.

Animals↗
PubMed1995

[Coronary artery bypass grafting without cardiopulmonary bypass in patients with LV dysfunction (EF < or = 30%)--a report of 3 cases].

The purpose of this article is to describe our technique for performing coronary artery bypass grafting without cardiopulmonary bypass and to demonstrate that this operation is safe and useful to the case of LV dysfunction. Between April 1988 and March 1994, 2 men and 1 woman aged 61 to 69 years (mean 65 years) with LV dysfunction (EF < or = 30%) underwent coronary artery bypass grafting without cardiopulmonary bypass. Saphenous vein grafts were placed to the right coronary artery (n = 2), left anterior descending artery (n = 2), and internal thoracic artery grafts were placed to the right coronary artery (n = 1), left anterior descending artery (n = 1). The post operative course were uneventful in all patients and discharged with no complications. All patients underwent coronary angiography, and 5 of 6 (83.3%) grafts placed without cardiopulmonary bypass were patent. In selected patients, coronary artery bypass grafting to the case of LV dysfunction without cardiopulmonary bypass can be performed safe and satisfactory graft patency rates.

Aged↗
PubMed1995

[Flow competition of right gastroepiploic artery graft in coronary artery bypass surgery].

We evaluated the competitive flow between the right gastroepiploic artery (RGEA) and native coronary artery in coronary artery bypass surgery with respect to anastomosis in a retrograde fashion and the relationship of the degree of proximal stenosis with the flow dependency. The RGEA has been used in 157 patients and was anastomosed in a retrograde fashion in 22 patients. There was no significant difference between the retrograde anastomosis and the antegrade anastomosis on revascularization to the left anterior descending coronary artery in terms of diameter (2.0 +/- 0.5, 1.68 +/- 0.2 mm), flow (21.8 +/- 13.2, 24.5 +/- 19.4 ml/min), early patency (100%, 100%) and string sign (0%, 0%). We examined angiographically the relationship between the preoperative degree of proximal stenosis and postoperative pattern of flow dependency in the right coronary artery distal to the RGEA anastomosis in 98 patients. With a proximal stenosis of 75% (n = 19), RGEA occlusion was observed in two patients (11%), native coronary-dependent flow in four (21%), balanced flow in nine (47%) and RGEA-dependent flow in four (21%). With a proximal stenosis of 90% (n = 16), native-dependent flow was observed in one (6%), balanced flow in six (38%) and RGEA-dependent flow in nine (56%) patients. With a proximal stenosis of 99%-100% (n = 63), RGEA occlusion was observed in three (5%) and RGEA-dependent flow in sixty (95%) patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Endourology update].

In urology, endoscopic surgery and laparoscopic surgery are generally named as endourology. Transurethral endoscopic surgery was originated in mid 19th century, and established by 1950s. At present, transurethral resection of the prostate, transurethral resection of the bladder tumor, transurethral incision of the urethral stricture, transurethral vesicolithotripsy, and transurethral ureterolithotripsy, were commonly performed in many urological clinics. Percutaneous nephrolithotripsy and extracorporeal shock wave lithotripsy were introduced in 1980s, and now, open operation for urolithiasis are rarely performed. In 1990s, as a new endourologic procedure, laparoscopic operations are being increasingly applied to the treatment of urological diseases; for example, laparoscopic pelvic lymphadenectomy, laparoscopic varicocelectomy, laparoscopic exploration of non-palpable testis, laparoscopic nephrectomy, and laparoscopic adrenalectomy etc. Of the variety of treatment modalities available, the most effective and least invasive method should be selected appropriately. So, we anticipate the further advancement in minimally invasive therapy, interdependently with our sufficient experience and skills.

Endoscopy↗
PubMed1995

[A case of surgical repair for the aortic insufficiency due to the tears of the aortic cusps during PTCA].

We report a rare case of aortic insufficiency due to the tears of the aortic cusps during percutaneous transluminal coronary angioplasty (PTCA). A 62-year-old man successfully underwent simultaneous aortic valve replacement and coronary artery bypass grafting. The post operative course was uneventful, and the patient was discharged in a stable condition. This report emphasizes the need to consider the possibility of acquired aortic insufficiency due to the complication of PTCA.

Angioplasty, Balloon, Coronary↗
PubMed1995

[Enlargement of the internal thoracic artery with intact vascular wall structure by construction of an arterio-venous shunt].

The purpose of this investigation was to examine whether construction of an arterio-venous shunt could enlarge the internal thoracic artery (ITA) and preserve normal structure of the vascular wall. Five mongrel dogs were used. Side-to-side anastomosis was made between the left ITA and left internal thoracic vein. These dogs were followed for about 6 weeks and diameters of bilateral ITAs were determined by angiography. The diameter of the left ITA was 2.67 +/- 0.5mm, which was significantly larger than the right ITA (2.24 +/- 0.4mm, as control, p < 0.01). The right to left ITA ratio was 119.4 +/- 6.9%. There was no significant difference in the morphologic features of endothelial cells between left and right ITAs. Several specimens of the left ITA showed morphologic changes of protruding nucleus, widening of intercellular junctions and creater formation. There was no significant difference between the ITAs with respect to thickness of media and the number of elastic fibers in the media. The smooth muscle cells just under the internal elastic lamina didn't appear to be synthetic phenotype. In conclusion, arterio-venous shunting enlarged the diameter of ITA, and caused minimum morphologic change in the intima and media.

Anastomosis, Surgical↗
PubMed1995

[A surgical case of descending aortic aneurysm combined with simultaneous aortocoronary bypass grafting through a left lateral thoracotomy].

A 71-year-old man with a descending aortic aneurysm was admitted to the hospital because of abnormal chest CT. Aortogram revealed an aneurysm of the descending aorta. His coronary angiogram showed 75% stenosis at LCX (Seg II). The graft replacement of descending aortic aneurysm and coronary artery bypass grafting (CABG) were performed through a left lateral thoracotomy. Postoperative course was good. Postoperative angiogram demonstrated successful reconstruction of the descending aorta and a patent bypass graft. The patient discharged healthy without any complications.

Aged↗
PubMed1995

Three-dimensional arrangement of collagen and elastin fibers in the human urinary bladder: a scanning electron microscopic study.

To clarify the arrangements of collagen and elastin fibers of the urinary bladder, we examined 9 human (male, aged 42 to 72) urinary bladders by scanning electron microscopy with chemical digestion methods. The mucosal layer was divided into 3 portions according to the collagen arrangement: the superficial portion interwoven densely by collagen fibrils, the middle portion layered by flat bundles of collagen fibrils and the deep portion made of a loose network of twisted collagen bundles. In the muscular layer, the smooth muscle fascicles were firmly covered with collagen sheets, while each muscle cell in a fascicle was accommodated by a thin sheath of collagen fibrils. The serosal layer consists of wavy collagen bundles piled up in a sheet, which was intercalated by clusters of adipose cells. Elastic fibers were, on the other hand, sparse throughout the bladder wall, except for denser networks around the blood vessels and muscle fascicles and beneath the peritoneal mesothelium. The arrangements of these components were discussed in relation to the mechanical function and compliance of the urinary bladder.

Adipose Tissue↗
PubMed1995

A case of unique communication between blind-ending ectopic ureter and ipsilateral hemi-hematocolpometra in uterus didelphys.

Uterus didelphys with double vagina and hemi-vaginal atresia is a rare syndrome of congenital anomalies. A 17-year-old girl had a right blind-ending ectopic ureter, the proximal end of which communicated with the ipsilateral uterine cervix of uterus didelphys. The patient presented with vaginal urinary incontinence after incision of the vaginal wall for right hemi-hematocolpometra. Following various examinations, the ipsilateral kidney was found to be absent. The ectopic ureter and communicating duct were resected, and the fistula was closed. The genesis of malformation of the female genitalia and urinary tract resulting in such a unique communication is discussed. The importance of preoperative meticulous examinations, including cysto-genitography, pelvic magnetic resonance imaging and panendoscopy with the patient under anesthesia, is emphasized.

Abnormalities, Multiple↗
PubMed1995

[Saphenous vein to saphenous vein bypass grafting in four redo CABG patients].

In four redo CABG patients, new saphenous vein grafts were anastomosed to the angiographically normal part of the old, and partially narrowed or occluded saphenous vein grafts in an end-to-side fashion. Inner surface of the old saphenous vein was confirmed to be smooth and free of atherosclerotic change during anastomosis. Postoperative course was uneventful and angiography demonstrated the good patency of new saphenous vein grafts in all patients. Although this technique is not acceptable if the old saphenous vein graft shows extensive atherosclerotic change, this method may be a useful alternative in case of limited saphenous vein graft disease in terms of less difficulty and operation time.

Aged↗
PubMed1994

Fetal urine production at different gestational ages: correlation to various compromised fetuses in utero.

To reveal which fetal life-threatening diseases significantly contribute to impairment of in-utero urine production and also to determine the gestational age at which time aberrant urine production becomes manifest, we observed 376 compromised fetuses (subject group) at 21-42 weeks' gestation using ultrasonography. A total of 358 uncomplicated fetuses, aged 21-40 weeks, were separately chosen as a control group. Statistical differences in the urine production rate between subject- and control-group fetuses were analysed using the Grubbs-Smirnoff test at corresponding gestational ages. Significant decreases were evident in: bilateral renal agenesis (100%) at 21-23 weeks; bilateral infantile polycystic kidney (100%) at 21-28 weeks; bilateral multicystic kidney disease (100%) at 21-31 weeks; donor fetuses with twin transfusion syndrome (TTS) (100%) at 21-28 weeks; post-term fetuses (100%) at 42 weeks; bilateral hydronephrosis (60%) at 21-38 weeks; non-immunologic hydrops fetalis (42%) at 21-35 weeks; intrauterine growth retardation (41%) at 29-40 weeks; and upper gastrointestinal tract obstruction (36%) at 30-38 weeks. Significant increases were noted in: recipient fetuses with TTS (100%) at 21-28 weeks, and unilateral hydronephrosis (36%) at 27-32 weeks. All indicate that urine production clearly delineates various fetal conditions in utero, in a closely disease-dependent relation to gestational age.

Diuresis↗
PubMed1994

What is the minimum number of heart rates necessary to evaluate fetal conditions at different gestational ages?

Our objective was to determine the minimum number of fetal heart rates (FHRs) needed to assess various fetal conditions adequately, focusing on FHR changes in relation to gestational age. We used probability distribution matrices previously derived from 10,934,604 FHRs of 743 uncomplicated fetuses. These matrices were made at nine consecutive 2-week intervals between 23 and 40 weeks' gestation, from which samples were taken after assigning random numbers to FHRs in sequence. As a variable, the difference rate (%) between the sample probability distribution matrix and its corresponding age-group probability distribution matrix was calculated. Scattergrams of difference rates vs. a given number of FHR samplings were analyzed using piecewise linear regression. One critical point per age-group emerged, ranging between 9000 and 10,000 beats, for all age-groups. A linear decrease in the difference rate was noted with a step-by-step increase in random sampling size of FHRs until reaching the critical point, beyond which the difference rate remained constant between 25-33%. The critical points indicate that the minimum number of FHRs for assessment of the fetus at 23-40 weeks' gestation is almost the same, between 9000 and 10,000, with 67-75% baseline variability (so called beat-to-beat variability) and 25-33% long-term variability regardless of advance in gestation.

Evaluation Studies as Topic↗
PubMed1994

Differential Na+,K(+)-ATPase activity and cisplatin sensitivity between transformants induced by H-ras and those induced by K-ras.

We examined the differential effects of the H-ras oncogene and the K-ras oncogene on cisplatin sensitivity in murine NIH/3T3 cells transfected with these oncogenes. Although the NIH/3T3 cells transformed with H-ras oncogenes (EJ-NIH/3T3 and Ha8-21) showed an increased resistance to cisplatin compared to the parental NIH/3T3, the cell lines transformed with K-ras oncogenes (DT and 1,8DNP2-2-5) did not. Compared with NIH/3T3, the 2 H-ras transformants reduced both the accumulation of cisplatin and the Na+,K(+)-ATPase activity in the membrane fraction. On the other hand, we observed no significant difference in cellular accumulation of cisplatin or in Na+,K(+)-ATPase activity between parental NIH/3T3 and the K-ras transformants. Since these ras transformants did not affect the cellular metallothionein content, transcriptional level of DNA polymerase beta or activity of glutathione-S-transferase which is not associated with cisplatin sensitivity, these results suggest that cisplatin resistance is brought about by the H-ras oncogene, but not by K-ras, and that induction of cisplatin resistance by H-ras is mainly due to a reduction of cisplatin accumulation and an impairment of Na+,K(+)-ATPase activity in the membrane fraction.

3T3 Cells↗