Biomedical subjects

Y Takimoto

Publications and source records attributed to Y Takimoto.

At least 55 records · Page 3Linked to original sources

PubMed1997

Porous-type tracheal prosthesis sealed with collagen sponge.

BACKGROUND: Reconstruction of a long section of the trachea is clinically problematic. Tracheal reconstructions using prostheses have met with limited success due to local infection, hemorrhage, luminal stenosis and prosthesis dislocation. METHODS: We have designed a porous type of tracheal prosthesis in which the mesh is sealed with collagen sponge. We used this prosthesis (50 mm in length) to reconstruct the cervical trachea in 10 mongrel dogs and evaluated its efficacy. RESULTS: One dog died due to an accident with anesthesia at 6 weeks and 1 of suffocation at 10 weeks. The other 8 dogs had an uneventful postoperative course until they were killed between 6 and 24 months after implantation. At sacrifice, all the prostheses had become completely incorporated into the host. Microscopic examination revealed advanced formation of a new epithelial lining in 1 dog at 6 months, and a confluent epithelial lining was observed in another dog at 12 months. Central stenosis was not significant in any of the animals. CONCLUSIONS: This tracheal prosthesis gives good results in canine tracheal reconstruction, and appears very promising for the clinical repair of tracheal defects.

Animals↗

PubMed1997

Intrathoracic tracheal reconstruction with a collagen-conjugated prosthesis: evaluation of the efficacy of omental wrapping.

Reconstructions of the intrathoracic trachea in 24 dogs were done with the use of 50 mm long collagen-conjugated tracheal prostheses. Omental wrapping was also done in 14 of the dogs (omentopexy group) to evaluate the efficacy of this option in comparison with results in the other 10 dogs (control group). All 24 dogs had uneventful postoperative courses and were killed at 4 weeks or 3, 6, or 12 months after the operation. Better epithelialization and fewer complications, such as mesh exposure and luminal stenosis, were observed in the omentopexy group than in the control group. Angiography and analysis of regenerated blood vessels revealed that vessel ingrowth had started within 4 weeks and that vessel formation reached its maximal point within 6 to 12 months in the omentopexy group. In contrast, revascularization of the subepithelial region in the control group was poor even after 3 months, and vessel formation continued for as long as 12 months. The differences between the two groups were considered to be mainly a result of the speed of blood vessel ingrowth into the regenerated mucosa. We conclude that our prosthesis can be used safely for intrathoracic tracheal reconstruction and that omental wrapping is a useful supplementary method that reduces the occurrence of complications.

Anastomosis, Surgical↗

PubMed1997

Electron microscopic study of the penile plaques and adjacent corpora cavernosa in Peyronie's disease.

BACKGROUND: We conducted ultrastructural studies to clarify the fine structure of penile plaques and adjacent corpora cavernosa, and the causative basis for the process, in Peyronie's disease. METHODS: Penile plaques and adjacent corpora cavernosa were obtained during surgical extirpation from 5 patients with Peyronie's disease. Control tissues from the tunica albuginea and adjacent corpora cavernosa were obtained at penile amputation from 2 patients with penile cancer. Prepared tissues were examined by using electron microscopy. RESULTS: Penile plaques were composed of collagen fibrils, amorphous particulate material, and fibroblasts in all patients. In 1 of 5 patients, myofibroblasts were found in the border area between the lesion and underlying structures. Smooth-muscle cells and endothelial cells resembling myofibroblasts were noted in adjacent corpora cavernosa. In this patient, the plaque progressively enlarged, and was removed within 1 year of onset of the induration. CONCLUSIONS: Fibromatosis in Peyronie's disease involves both fibroblasts and myofibroblasts, which undergo sclerosis in some phase. In addition, smooth-muscle cells and endothelial cells in the adjacent corpora cavernosa may be incorporated in the fibromatosis.

Aged↗

PubMed1997

A patient with basophilic-eosinophilic myeloproliferative disorder showing monosomy 7 and hyperhistaminemia.

We encountered a male patient with marked basophilia and eosinophilia complicated by anemia, thrombocytopenia, myelofibrosis, and hyperhistaminemia. Since morphological abnormalities were unclear and since chromosome analysis showed 45,XY,-7, a diagnosis of basophilic-eosinophilic myeloproliferative disorder was made. After administration of prednisolone and cytarabine ocfosfate, basophil and eosinophil levels decreased, but blasts transiently appeared in the peripheral blood. Chromosome analysis performed at the time of appearance of blasts showed a clone with 45,XY,-7,del(16)(q22). Subsequently, pancytopenia developed, after which white blood cell count and its classification were normal, as were chromosome findings. In this patient, monosomy 7 seemed to have induced myeloproliferative disorder with basophilia and eosinophilia, and del(16)(q22) may have enhanced the eosinophilia.

Aged↗

PubMed1996

Nerve regeneration across a 25-mm gap bridged by a polyglycolic acid-collagen tube: a histological and electrophysiological evaluation of regenerated nerves.

In the study reported here we have examined the nerve regeneration that occurs over a 25-mm gap using a novel biodegradable nerve guide tube. The tube was a composite of polyglycolic acid (PGA) mesh coated with collagen which was filled with neurotrophic factors. The left sciatic nerve of ten adult cats was dissected. The stumps were connected by the tube, and fixed gap. Histological examinations carried out 4-16 months after implantation of the tube revealed regeneration of well vascularized nerve tissue. Regeneration of both myelinated, unmyelinated axons and Schwann cells was confirmed by electron microscopy 5 months after surgery. Following injection of horseradish peroxidase (HRP) into a site peripheral to the regenerated segment of the sciatic nerves, motoneurons in the ventral horn of the spinal cord, afferent terminals in the medial portion of the dorsal column of the medulla oblongata, and sensory afferent nerve terminals in the dorsal horn of the spinal cord were labelled. Electrophysiological examinations revealed restoration of evoked electromyograms and sensory evoked potentials (SEPs) recorded from the cerebral cortex as well as the spinal cord. We also found that some of the regenerated motor axons exhibited branching in the regenerated segments. In two cases, a single motoneuronal axon from the regenerated side projected to both flexors and extensors, simultaneously. Our results indicate that the PGA-collagen composite tube is a promising tool for use as a nerve guide tube in peripheral nerve regeneration.

Animals↗

PubMed1996

Anaplastic large-cell lymphoma (Ki-1 lymphoma) with expression of IL-5 mRNA and eosinophilic invasion.

We examined a patient with anaplastic large-cell lymphoma (Ki-1 lymphoma) showing eosinophilic invasion of the tumor tissues. The number of eosinophils in the peripheral blood changed as a function of the stage of the disease. The IL-5 gene was expressed in the tumor tissues, suggesting that the eosinophilic invasion and eosinophilia were caused by IL-5 derived from the lymphoma cells.

Adult↗

PubMed1996

A patient with ammonia-producing multiple myeloma showing hyperammonemic encephalopathy.

Explore the source record for details and available documents.

Aged↗

PubMed1996

[A case of acute myelocytic leukemia in relapse controlled by continuous home administration of Ara-C].

A 50-year-old male with acute myelocytic leukemia (AML) achieved complete remission after combination chemotherapy. However, the AML recurred after six months. He did not respond to various treatments and his condition deteriorated after chemotherapy. After we attempted continuous administration of cytosine arabinoside (Ara-C), the number of leukemic cells was controlled for nine months. During this period, he could stay and receive treatment with Ara-C at home. In this case, the continuous administration of Ara-C at home was truly effective not only to control the number of leukemic cells but also to improve the quality of life.

Antimetabolites, Antineoplastic↗

PubMed1996

[Immunological effect of recombinant interferon-gamma on tumor infiltrating lymphocytes of renal cell carcinoma--relationship with clinical stage].

We studied the relationship between clinical stage and tumor infiltrating lymphocytes (TIL) in 26 cases of renal cell carcinoma. In 10 patients, interferon-gamma (IFN-gamma) was administered preoperatively (administration group); 5 patients had low stage (Robson < or = I), and the remaining 5 patients had high stage (Robson > or = II) tumors. The other 16 patients underwent nephrectomy alone without preoperative IFN administration (control group); 11 patients had low stage, and the remaining 5 patients had high stage tumors. Immunohistochemical studies of tumor infiltrating lymphocytes in renal cell carcinoma showed a significantly high incidence of CD3, CD8, CD11b and ICAM-1 in the administration group, while CD4, LFA-1 and Ber-MAC3 were increased without significance (p < 0.05). Concerning clinical stage (Robson), a significant increase in CD3, CD8, CD11b and ICAM-1 was observed in the patients with high-stage tumors in the administration group compared to those in the control group (p < 0.05). This suggested that TIL could be changed by preoperative administration of IFN-gamma.

Adult↗

PubMed1996

[A case study of metastatic renal cell carcinoma in lungs showing complete response to continuous subcutaneous injection of interferon alpha and gamma].

Previously, we reported a case of complete response (CR) of metastatic renal cell carcinoma with inhalant interferon-gamma. This inhalant therapy was considered effective against metastatic lung hilar tumors. On the other hand, metastatic tumors of the peripheral lung field tumor did not respond to the inhalation therapy. We report, a case of metastatic renal cell carcinoma in peripheral lungs showing complete response to continuous subcutaneous administration of interferon alpha and gamma. A 53-year-old woman was admitted to our hospital because of a large palpable mass in the left upper quadrant in March, 1994. Computerized tomographic (CT) scan disclosed a huge renal tumor. To reduce the tumor size, transarterial embolization, and subcutaneous administration of interferon-gamma were performed. In April 1994, the tumor was completely excised. In the post-operative course, multiple metastases were recognized in the lower peripheral lung field, subcutaneous administration of IFN-gamma and inhalation of IFN-gamma were begun, but the tumor size increased in October 1994. She underwent continuous subcutaneous administration of IFN-alpha and gamma. Three months later, the lung tumor disappeared. She has remained tumor-free as of October 1995. We concluded that this therapy may be effective against metastatic renal cell carcinoma in the lungs.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1996

Histological progression of follicular lymphoma associated with p53 mutation and rearrangement of the C-MYC gene.

Follicular lymphoma is a low grade malignant lymphoma. However, some follicular lymphomas undergo histological transformation into higher grade malignant lymphomas. We recently encountered a diffuse large cell lymphoma which seemed to have progressed from a follicular lymphoma and which finally transformed into a small non-cleaved lymphoma. Each stage of the histological transformation was accompanied by increasing clinical grades of malignancy. It was suspected that in our patient a follicular lymphoma initially developed due to rearrangement of the BCL2 gene, and then underwent histological transformation into a diffuse large cell lymphoma, which was associated with p53 mutation. Subsequent rearrangement of C-MYC promoted the histological transformation of this diffuse large cell lymphoma into a small non-cleaved lymphoma. Our findings indicate that p53 mutation and rearrangement of C-MYC are involved in the histological transformation of follicular lymphomas into more advanced lymphomas.

Aged↗

PubMed1996

[Chronic myelomonocytic leukemia with repeated respiratory failure associated with leukocytosis following splenic arterial embolization and splenectomy].

A 32-year-old female was admitted due to splenomegaly and leukocytosis in September, 1993. The leukocyte count was 26,900/microliter with 29% monocytes (7,800/microliter). A diagnosis of the chronic phase of chronic myelomonocytic leukemia was made. On November 19, 1993, splenic arterial embolization was performed. After the embolization, the leukocyte count rapidly increased, and acute respiratory failure developed. The respiratory condition was improved by methylprednisolone (m-PRED) pulse therapy. Subsequently, the effectiveness of chemotherapy gradually decreased, and there was an increase in the leukocyte count. Respiratory failure developed again but was successfully treated with m-PRED pulse therapy in addition to aclarubicin. On July 4, 1995, splenectomy was performed. The leukocyte count rapidly increased, and acute respiratory failure again developed. She did not respond to m-PRED pulse therapy, but the respiratory condition was markedly improved by leukoplasmapheresis. The respiratory failure in this patient may be associated with capillary leak syndrome due to neutrophilia. In addition, stasis of increased monocytes in the pulmonary capillaries and their infiltration into the pulmonary parenchyma and alveoli was thought to have occurred.

Adult↗

PubMed1996

[Mantle cell lymphoma associated with hyper-IgE syndrome].

A 69-year-old woman was admitted with generalized lymph node swelling and huge splenomegaly. CD5(+), Sm-IgM (+) and SmIgD (+) lymphocytes were increased in lymph nodes, spleen and bone marrow, and she was diagnosed as having mantle cell lymphoma. A diagnosis of hyper-IgE syndrome was also made, because IgE was markedly increased (174,780 u/ml) and chronic dermatitis, which was often complicated with infection, occurred repeatedly on her extremities. In this case, interleukin-4 was considered to be one of the factors involved in the hyper-IgE syndrome, because increased IgG1 and reduced IgG2 were observed. Immunological abnormality associated with the hyper-IgE syndrome seemed to contribute to the development malignant lymphoma in this case.

Aged↗

PubMed1996

[Sézary syndrome associated with small intestinal amyloidosis].

A 68-year-old female diagnosed as having Sézary syndrome because of generalized erythroderma and increased lymphocytes with convoluted nuclei in 1988 was treated with steroids. However she did not respond to therapy and died due to pneumonia and aggravation of Sézary syndrome in September, 1994. Dyspeptic diarrhea was observed for two months before she died. Autopsy revealed local deposition of amyloid A protein in the mucosa of the small intestine, which might have been the cause of dyspeptic diarrhea. This was a rare case which Sézary syndrome accompanied by localized amyloidosis.

Aged↗

PubMed1995

Mechanism of regulation of PDGF-A chain gene expression by serum and TPA.

The state of induction of the platelet-derived growth factor (PDGF) A chain markedly differs among drugs and cells. The increase in A chain mRNA by serum was due to activation of transcription. Transcription was also activated by cycloheximide (CHX) even during serum starvation, indicating that the expression of the PDGF-A chain is inhibited by transcription suppressor factor with a short life during serum starvation. On the other hand, post-transcriptional regulation played a very important role in the increase in A chain mRNA by 12-O-tetradecanoylphorbol-13-acetate (TPA) and superinduction by TPA and CHX. We also analyzed the regions of PDGF-A chain gene that respond to serum and TPA by the chloramphenicol acetyltransferase (CAT) assay and the gel retardation assay. The region from TATA to -135 bp has the activity of the basal expression of PDGF-A chain gene and is considered to be involved in down regulation after the treatment with serum and TPA. Elements that respond to serum and increase the expression of PDGF-A chain gene are present in the region from -135 bp to -223 bp. Elements that inhibit the expression of PDGF-A chain gene during serum starvation are present in the region from -223 bp to -416 bp.

Base Sequence↗

PubMed1995

Endoscopic sclerotherapy in a rat model of esophageal varices.

BACKGROUND: Partial ligation of the portal vein has been shown to induce not only prehepatic portal hypertension but also esophageal varices in the rat. We developed an esophageal endoscopic system for endoscopic sclerotherapy of esophageal varices in rats. In the present study the efficacy of three sclerosing agents, 1% polidocanol, 5% ethanolamine oleate, and 99.5% ethanol, was compared, using this model. METHODS: Sclerosing agents were injected paravariceally in 42 rats with partial portal vein ligation. Their efficacy was compared endoscopically and histologically. RESULTS: Ethanol induced the most severe ulcers and subsequent stricture formation. The damage induced by 1% polidocanol was mild and healed quickly, whereas 5% ethanolamine oleate induced moderate damage. The varices disappeared because of fibrosis that developed after ulceration. CONCLUSIONS: The results were consistent with the known properties of these three agents, suggesting that the esophageal endoscopic system for sclerotherapy in rats provides a useful method for experimental studies of sclerotherapy.

Animals↗

PubMed1995

[A study of effective administration of recombinant interferon-gamma in renal cell carcinoma regarding immunological influence on peripheral blood lymphocytes].

Immunological effect of recombinant interferon gamma (IFN-gamma) was studied in 18 cases of renal cell carcinoma. Sixteen of them were administered IFN-gamma as post-operative adjuvant therapy. Two of them were administered IFN-gamma for metastatic renal cell carcinoma. All of them were followed for at least 1 year. We divided the patients into two groups. One group subcutaneously received IFN-gamma every other day for 16 days, then 4 weeks later every week for one year (group A), and the other group, received alternate subcutaneous IFN-gamma every other day for 16 days and every week for 4 weeks (group B). For immunological testing, peripheral blood lymphocytes were obtained before treatment on day 1, 2 weeks later, 6 months later and 12 months later. The cells were tested for natural killer activity (NK), antibody dependent cellular cytotoxicity (ADCC), positive lymphocytes of CD3, CD4, CD8 and CD11b. Both ADCC and NK activity were increased after therapy, especially in group B. CD3, CD4 and CD8 positive lymphocytes were increased by means of IFN-gamma. On the other hand, CD11b-positive lymphocytes could not be elicited in group B. Tumor regression was observed in 2 cases of metastatic renal cell carcinomas. When clinical responses were observed, both ADCC and NK were elicited as compared with the pretreatment values. Our findings indicated that ADCC and NK could be elicited in group B.

Adult↗

PubMed1994

Gene regulation by the 5'-untranslated region of the platelet-derived growth factor A-chain.

Platelet-derived growth factor (PDGF) A-chain gene contains a long 5'-untranslated region (5'-UTR) of 850 bp. We evaluated the role of the 5'-UTR by chloramphenicol acetyltransferase (CAT) assay. CAT activity appeared when the fragment +99 bp downstream from the initiation site (+1) was present but disappeared in the fragment to +184 bp. It appeared again at +338 bp but disappeared again to +609 bp. The fragment from +99 to +184 inhibited CAT activity by a post-transcriptional mechanism, as RNA of CAT was observed but CAT activity was not.

Base Sequence↗