Biomedical subjects
Publications and source records attributed to Y Ichikawa.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
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Before and after hatching, J-chain-positive cells (JPC) were observed by immunoelectron microscopy in lymphoid tissues from chickens that had been chemically bursectomized (Bx) in ovo. These JPC were detected in spleens both of normal and Bx birds. Subcellular localization of J chains showed more variations in normal than Bx chickens. From these findings, JPC could be divided into JPC subpopulations in chickens.
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Endometrial carcinoma coexisting with pregnancy is rarely observed. We report here the case of a 35-year-old woman with an endometrial carcinoma that was diagnosed 6 months after childbirth. Preoperative magnetic resonance imaging (MRI) revealed a cystic mass attached to the uterus, with a papillary projection on the wall of the mass. The patient underwent complete surgical extirpation and five postoperative courses of adjuvant chemotherapy, given that the tumor contents had leaked into the peritoneal cavity when the capsule of the tumor ruptured intraoperatively. Microscopic examination revealed an endometrioid adenocarcinoma in the muscular layer close to the uterine serosa that was presumed to derive from adenomyosis. Further investigation is required to elucidate the pathogenesis of endometrial carcinoma in association with pregnancy and adenomyosis.
This investigation was conducted to determine whether renal transplantation can improve sexual function in male patients with chronic renal failure. The authors retrospectively studied 121 men undergoing renal transplantation who complained of any type or degree of sexual dysfunction pre-operatively. Sexual function was evaluated by questionnaire which included erectile, ejaculative, and orgasmic functions. Pre- and postoperative frequency of sexual intercourse was also recorded. Patient characteristics, laboratory data, and endocrinologic profiles were analyzed to identify factors that might influence sexual function. In patients with hormonal determinations, results essentially normalized after transplantation. However, only 43 patients (35.5%) reported improvement of overall sexual function after renal transplantation, while 34 (28.1%) reported worsening. Although frequency of sexual intercourse was unaffected by transplantation, 15 of 20 patients who had no intercourse before transplantation initiated intercourse afterward. These 15 patients all underwent transplantation before 40 years of age. Comparisons of variables by sexual function showed significant differences for type of immunosuppressive treatment, interval after renal transplantation, and serum concentration of hemoglobin A1c. It is concluded that renal transplantation cannot improve sexual function in all patients, although hormonal profiles were largely normalized, and that renal transplantation should be encouraged at a younger age.
We assessed long-term side effects with characteristics of female climacteric disorders in prostate cancer patients treated with luteinizing hormone-releasing hormone (LHRH) agonists. Such side effects are not considered to be serious, though they can significantly affect patient quality of life. Sixty-four prostate cancer patients treated with LHRH agonists and 30 benign prostatic hyperplasia patients, as a control group, were surveyed by questionnaire. The median age of the cancer patients was 74.9 years old, ranging from 60 to 94 years, and the median LHRH agonist dosing period was 16.5 months, ranging from 1 to 64 months. The results of the questionnaires were compared between the patients and the controls, as well as between different variables. Sixty (93.8%) of 64 patients claimed symptoms similar to female climacteric disorders. Further, more than 50% of the symptoms included in the questionnaire were reported by 14 (21.9%) of the patients. Symptoms reported by the patients were more severe than those by the controls. Hot flashes, sleep disturbance, and fatigue recorded high scores in the patient questionnaires as compared with those of the controls. In addition, as the term of LHRH agonist use increased, complaints of sweating or coldness in hands and feet increased. Patients without bone metastasis frequently experienced heaviness in the head and headaches compared to those with bone metastasis. The results of our questionnaire-based outcome study showed that side effects similar to female climacteric disorders in prostate cancer patients treated with LHRH agonists were more severe than in the control group, which could be detrimental to quality of life and general well-being.
The authors successfully applied a method to accelerate endothelialization by tissue fragmentation to a small diameter fabric vascular prosthesis. Tissue fragment seeded grafts showed rapid healing of the neointima. The thrombogenicity of the collagen fibrils in the fragments, however, caused major problems when the method was applied to small diameter grafts: the positively charged collagen fibrils aggregated the negatively charged platelets. The authors masked the fibrils electrostatically with heparin molecules, which are negatively charged. A canine jugular vein was resected, minced into tissue fragments, and suspended in the heparin solution; it then was sieved through the wall of a fabric prosthesis. The grafts (4 mm internal diameter and 3.5 cm in length) were implanted into both carotid arteries of six dogs (12 grafts). Tissue fragment seeded grafts without heparin also were implanted into six dogs. As a control, preclotted fabric grafts were implanted into six dogs (12 grafts). These grafts occluded within 1 week, whereas all the masked grafts were patent without thrombi. In vitro examination of heparin release revealed that approximately 92% of heparin in the graft was released during the first 5 hr, but approximately 6% remained after 25 hr. These results indicate that the method is applicable to small diameter arterial grafts.
A new RV-PA conduit with a natural valve was developed using bovine jugular vein. To maintain the natural, mechanical properties of the veins, a hydrophilic cross-linking reagent, a glycerol polyglycidyl ether polyepoxy compound (PC) was used. The treatment has already been proven in the field of vascular grafts to be able to reduce antigenicity, biodegradability, and degenerative changes such as calcification, to induce antithrombogenicity with hydrogenicity, and to improve affinity to host cells. Bovine jugular veins were cross-linked with the reagent and were implanted as a conduit into the RV-PA position in six dogs. The main PA was ligated after implantation. One animal died due to bleeding 2 days after implantation; the other animals were healthy and allowed to survive until they were sacrificed. The graft was very soft and as pliable as native tissue, and was as strong as a heart valve. Post-operative catheterization and angiography showed adequate function of the valve. Macroscopic and microscopic observations revealed the antithrombogenicity of the graft in this animal study. These results indicated that this newly developed biologic valved conduit has a high probability of overcoming many problems observed in existing RV-PA conduits.
A vascular prosthesis that can induce a neointima similar to a natural arterial wall is reported. The authors have developed a sealing method using autologous tissue fragments. The sealed graft showed many advantages, with characteristic neointima formation in an animal study. The grafts were implanted in the thoracic descending aortae of 40 dogs and were removed from 1 hour to 608 days after implantation. Another 40 dogs, used as controls, had a fabric graft implanted using the preclotting method. The luminal surface of the sealed graft was completely endothelialized and the original adipose tissue fragments were absorbed within 1 month. Smooth muscle cells infiltrated and proliferated at the same time as endothelialization took place. Most of the smooth muscle cells were arranged in parallel rows and oriented circumferentially within the graft. At 1 month, elastic fibers appeared around the smooth muscle cells near the anastomotic sites. In the long-term specimens, these elastic fibers constituted a fine lamina in the neointima. Intimal hyperplasia and degenerative changes in the neointima were not observed. These results indicated that the sealing method could induce a very stable neointima with a smooth muscle cell layer and elastic laminae similar to a natural arterial wall within a short period of time throughout the graft wall, with maintenance of the neointima for a long period of time after implantation.