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Biomedical subjects

M Gotoh

Publications and source records attributed to M Gotoh.

At least 397 records · Page 22Linked to original sources
PubMed1989

A crucial effect of splenectomy on prolonging cardiac xenograft survival in combination with cyclosporine.

In this study we investigated the effect of splenectomy in combination with cyclosporine (CsA) on survival of heterotopic cardiac xenografts from hamster to rat. A 12-fold prolongation of mean cardiac xenograft survival, to 41 days, was accomplished with the combined therapy. In both untreated controls and CsA-treated recipients rejection occurred in 3 days. Splenectomy by itself prolonged xenograft function to 5 days. Evidence of humoral-mediated rejection in this cross-species combination was given for the extensive thrombosis and hemorrhage in the subepicardial area, the appearance of lymphocytotoxic titers just before graft function ceased, and the presence of IgM deposits in subepicardial vessels of the xenograft. CsA by itself could not modify this pattern of rejection. Splenectomy decreased antibody formation significantly and rejection became more cellular in nature. The regimen of splenectomy in association with CsA suppressed antibody titers and produced a CsA dose-dependent prolongation of xenograft survival. Thus, a complementary or synergistic effect is the result of the immunosuppressive regimen of splenectomy and CsA in hamster-to-rat cardiac xenografts. In this study the effect of splenectomy in controlling the humoral response in concordant xenografts and its role in future clinical xenografting is emphasized.

Animals↗
PubMed1989

[Succinylcholine neuromuscular blockade in a case of pseudocholinesterase variant].

Since there is little or no pseudocholinesterase at the motor end plate, the neuromuscular blockade by succinylcholine is terminated by its diffusion away from the end-plate into extracellular fluid. Pseudocholinesterase (ChE), therefore, influences the duration of action of succinylcholine (SCC) by controlling the rate of hydrolysis before it reaches the end-plate. SCC neuromuscular blockade can be prolonged in the presence of an atypical form of ChE. A 37 year old male with the deficiency of ChE activity underwent pancreatico-duodenectomy under neuroleptanesthesia. The mode, duration and treatments of neuromuscular blockade following succinylcholine (SCC) were studied using train-of-four (TOF). SCC was administered 6 times (total 170 mg) during the operation. Prolonged apnea was noted after the first intravenous injection of SCC (60 mg, 1 mg.kg-1). It was found that spontaneous resolution of the neuromuscular block had four phases and there was a pronounced fade of the TOF response. After the second injection of SCC (30 mg), a remarkable fade of the TOF was detected and the character of the block was considered to be a desensitizing block (phase II block). The block was treated by intravenous infusion of fresh frozen plasma (FFP) (400 ml) which contained ChE, at the rate of 231 +/- 56 IU/l/37 degrees C begun shortly after the fifth injection of SCC (20mg). The duration of the block was remarkably shortened but the recovery curves were almost unchanged, indicating the diffusion of SCC away from the end-plate and/or that receptor-channel is presumably slow. The neuromuscular blockade was fully reversed by additional injection of FFP (400 ml) before extubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Case report: an unstable bladder with bilateral epididymitis, urge incontinence and unilateral reflux].

We report a 10-year-old boy with and unstable bladder, bilateral epididymitis, urge incontinence, bed wetting, and unilateral reflux. Previously, he complained of urinary incontinence and was operated on elsewhere with Y-V plasty in the bladder neck and pulling out a balloon catheter through the urethra. Following the surgery the urinary force was weakened, incontinence got worse and bilateral epididymitis broke out frequently. Since the patient was refractory to anti-cholinergic medicine, sacral nerve block, antireflux operation and narrowing the bladder neck were attempted. The surgery was successful in eradicating reflux and urinary tract infection, but failed to normalize the extremely widened bladder neck. Urge incontinence and bed wetting recurred 11 months after the sacral block, which was effective in a selected patient. We believe that Y-V plasty at the bladder neck should not be indicated for a patient with bladder dysfunction closely related to an unstable bladder.

Child↗
PubMed1989

[Ectopic ureteral opening: clinical assessment of 13 cases].

Thirteen cases of ectopic ureteral opening, surgically intervened during the past 10 years, were reviewed regarding the patients profiles, diagnostic procedure, treatment and concomitant anomalies. The diagnostic procedures are consisted of the conventional methods such as an intravenous urography, a vaginography, and a renoscintigraphy, which are important to identify and locate the immature kidney or the kidney with duplication anomaly. An angiographic examination is to be abandoned because it is invasive and rather insensitive. The surgical treatment should be determined depending on the renal function remained, ureteral morphology and the site of the ureteral opening.

Adolescent↗
PubMed1988

myc family gene abnormality in lung cancers and its relation to xenotransplantability.

In order to study the relationship between tumor transplantability to the nude mouse and abnormality of the myc family genes (c-myc, N-myc, L-myc) in human primary lung cancers, 32 various lung cancers were analyzed for abnormality of the myc family genes by Southern blot hybridization, and were transplanted s.c. into nude mice. Southern blot analysis showed that four non-small cell carcinomas and three small cell carcinomas had amplified c-myc and L-myc genes, respectively. Allelic deletion of the L-myc gene was observed in seven cancers, of which two also had an additional band of the c-myc gene or amplification of the L-myc gene. No abnormality of the N-myc gene was observed in this series. Of 13 cancers with abnormality of the myc family genes, 11, including all tumors with myc gene amplification, were transplantable to nude mice. Of 19 tumors without any abnormalities of the myc family genes, however, only five were transplantable to nude mice (P less than 0.005). These results indicate that abnormality of the myc family genes, especially gene amplification, might promote tumorigenic ability in xenotransplantation of lung cancers and this phenomenon might be closely related to the function of the myc gene.

Animals↗
PubMed1988

Immunohistochemical localization of pulmonary surfactant apoproteins in various lung tumors. Special reference to nonmucus producing lung adenocarcinomas.

Eighty-nine primary lung carcinomas and 23 metastatic lung tumors were immunohistochemically studied for the expression of pulmonary surfactant apoproteins, by using monoclonal (PE-10) and polyclonal antibodies. Surfactant apoprotein was demonstrated in the cytoplasm and/or nuclear inclusion bodies of only primary lung adenocarcinomas (36 of 75 cases), not in any other histologic type of primary lung carcinoma or in metastatic lung tumors. In primary lung adenocarcinoma, although typical type II pneumocyte type adenocarcinoma was not included in the current series, the majority of surfactant apoprotein-positive single cell type tumors were of the Clara cell type, with a single bronchial surface epithelial cell type, according to the light microscopic subclassification of adenocarcinoma cells. The Clara cell type adenocarcinomas could at times be distinguished only with difficulty from adenocarcinoma of type II pneumocyte type. Normal and hyperplastic type II pneumocytes were of course positive for surfactant apoprotein in the cytoplasm. However, none of the positive cells could definitely be identified as Clara cells in non-neoplastic lungs. The findings obtained in this study indicate that surfactant apoprotein is a good marker to distinguish adenocarcinoma of the lung from other histologic types of lung cancer and from neoplasms metastatic to the lung, and that type II pneumocytes and Clara cells, non-neoplastic and neoplastic, are morphologically and functionally closely related and might belong to the same cell lineage.

Adenocarcinoma↗
PubMed1988

Morphometric and cytochemical evaluation of clofibrate-induced peroxisomal proliferation in adult rat hepatocytes cultured on floating collagen gels.

The present ultrastructural morphometric and cytochemical studies demonstrate clofibrate induced changes in peroxisomes in adult rat hepatocytes maintained for 14 days in primary culture on floating collagen gels. Catalase activity and the number and diameter of peroxisomes were reduced in hepatocytes cultured for between 2/3 and 7 days. However, hepatocytes cultured for 7-14 days had well-developed peroxisomes containing crystalloid nucleoids. The number of anucleoid peroxisomes in hepatocytes treated with 2 mM Na clofibrate increased with culture age, and by day 14 the number was 2.9 times greater than in freshly isolated hepatocytes. Catalase activity, as well as the number of nucleoid-containing peroxisomes were much greater in treated hepatocytes than in untreated controls, but decreased slightly with culture age. The diameter of peroxisomes was not reduced in the treated cells. These results suggest that the treatment with Na clofibrate is effective both for proliferation and maintenance of peroxisomes and for enhancing catalase activity. In treated hepatocytes, matrical plates were formed in peroxisomes from days 5 to 14 and the number of plate-containing peroxisomes increased with culture age.

Animals↗
PubMed1988

Extracellular calcium protects cultured rat hepatocytes from injury caused by hypothermic preservation.

Effects of various preservation solutions were compared in an experimental hypothermic preservation model using cultured rat hepatocytes. Hepatocytes prepared by the collagenase perfusion method were cultured for 48 hr, then the medium in each culture dish was exchanged for various preservation solutions, and the dishes were hypothermically (0-2 degrees C) stored in a refrigerator for 12-72 hr. After the preservation period, the hepatocytes were cultured again at 37 degrees C for 2 hr. Hepatocytes' viability after 18-hr preservation and reculture was greater when they were preserved in "intracellular" rather than "extracellular" solutions. Even with Euro-Collins solution (intracellular solution), hepatocyte viability decreased to approximately 20% after 24-hr preservation, and an increase in the cellular lipid peroxide content was observed. However, when this solution contained a submillimolar concentration of calcium, lipid peroxidation was significantly suppressed and hepatocyte viability was dramatically improved. Vitamin E was almost equally effective and a marked synergistic effect was observed with calcium. Calcium was found to be capable of maintaining the cellular glutathione level during cold storage, which seems to suppress lipid peroxidation and consequently improve hepatocyte survival.

Animals↗
PubMed1988

Induction of antigen-specific unresponsiveness to pancreatic islet allografts by antilymphocyte serum.

The mechanism (or mechanisms) underlying the indefinite survival of DBA/2 islet allografts in strongly histoincompatible (C57BL/6xA)F1 (B6AF1) mice, induced either by the combined use of Ficoll-prepared crude islets and treatment of recipients with antilymphocyte serum (ALS), or by the use of handpicked, purified islets in nonimmunosuppressed recipients, was examined. B6AF1 mice bearing DBA/2 crude islet allografts for more than 100 days following ALS treatment accepted secondary DBA/2 crude islet allografts, but acutely rejected third-party A.SW crude islet allografts. This antigen-specific unresponsiveness to islet allografts can be successfully transferred into syngeneic B6AF1 mice by spleen cells. However, the state of unresponsiveness to donor antigen observed in these animals appears to be relatively weak, since transplantation of DBA/2 skin allografts or injection of DBA/2 spleen cells (5 x 10(7] caused acute rejection of long-term-accepted islet allografts. In contrast, B6AF1 mice bearing DBA/2 purified islet allografts over 100 days without immunosuppression rejected the secondary DBA/2 crude islet allografts acutely. Transfer of spleen cells obtained from these animals to syngeneic B6AF1 mice failed to induce prolongation of DBA/2 crude islet allografts. Thus, the mechanism (or mechanisms) involved in the long-term acceptance of islet allografts induced by the use of ALS and crude islets appears to be different from that involved in the long-term acceptance of purified islet allografts. The possible roles played by ALS in the induction of specific unresponsiveness to islet allografts are discussed.

Animals↗