Biomedical subjects
Publications and source records attributed to T Hanafusa.
We report a case of sigmoid colon cancer in which visualization of an appendiceal mucocele was unexpectedly found during 67Ga scintigraphy, and discuss a proposed mechanism of uptake.
Interleukin (IL-1), an inflammatory cytokine that is detected in the thyroid tissues of patients with autoimmune thyroiditis, is believed to be involved in the disease process. To clarify the role of IL-1 in the development of autoimmune thyroiditis, we investigated the effects of interleukin-1 beta (IL-1 beta) on the morphology of human thyrocytes in monolayer culture as well as the effect on thyroid peroxidase (TPO) content of these cells. Human normal thyrocytes were cultured with IL-1 beta for 4 days in the presence and absence of TSH. In morphologic studies, cultured cells were fixed for examination by scanning electron microscopy and for immunofluorescent staining of acting filaments. IL-1 produced striking morphologic changes in the cultured thyrocytes, including the cytoplasmic retraction and dissociation and/or depolymerization of actin filaments. These changes were unrelated to TSH stimulation. For detection of TPO, cultured cells were stained by an immunofluorescent technique and analyzed by fluorescence photometry. IL-1 reduced the TPO content and inhibited the TSH-induced increase in TPO in a concentration-dependent manner. These morphological changes and the reduction in TPO content of cultured thyrocytes suggest that IL-1 modulates the pathophysiology of autoimmune thyroiditis.
A quantitative study of the effect of carnitine deficiency on expression of glycolytic and gluconeogenic enzymes was performed using juvenile visceral steatosis mice which are systemically deficient in carnitine. The amounts of glucokinase and L-type pyruvate kinase mRNA were reduced in homozygotes, compared to heterozygotes and normal controls at 2 and 8 weeks. Liver-type phosphofructokinase, however, did not differ significantly. The abundance of fructose 1,6-bisphosphatase mRNA was unchanged at 2 and 8 weeks. The level of phosphoenolpyruvate carboxykinase mRNA was increased slightly at 2 weeks, but not at 8 weeks. A part of these changes could not be explained by the plasma glucose or insulin level. Carnitine administration restored the mRNA of these enzymes to normal levels. These results suggest that carnitine deficiency affects the expression of these liver enzymes.
In order to clarify the nature of T lymphocytes infiltrating the pancreatic islets of patients with insulin-dependent diabetes mellitus (IDDM), we analysed T cell receptor (TCR) gene transcripts expressed in pancreatic biopsy specimens of patients with recent-onset IDDM. We also investigated the expression of cytokines (interferon-gamma: IFN-gamma; tumour necrosis factor-alpha: TNF-alpha; interleukin-4: IL-4; interleukin-6: IL-6) in the same specimens. The TCR V beta repertoire was not restricted either in the pancreas or the peripheral lymphocytes of IDDM patients. In contrast, the TCR V alpha repertoire was restricted in the pancreas, but not in the peripheral blood lymphocytes, of IDDM patients. The sequence analysis of the complementarity-determining region 3 (CDR3) of the TCR alpha revealed the presence of dominant clonality in alpha chains of T cells in the patients. IFN-gamma mRNA was highly expressed in the pancreas of IDDM patients, while IL-4 mRNA was deficient. A lower level of expression of IL-6 mRNA was detected in the IDDM pancreas than in the control tissue. These results indicate that T cells bearing a distinct TCR alpha chain are selectively retained and activated within the pancreas of recent-onset IDDM.
BACKGROUND: Tacrolimus (FK 506) was introduced into organ transplantation as a powerful immunosuppressive but with several adverse effects. In fact, an appropriate protocol for using this agent has not yet been established. On the basis of pharmacokinetic studies and the reports of its administration as a continuous intravenous infusion, we designed the regimen of every eight hours in order to reduce the daily dosage. METHODS: Tacrolimus was given to nine patients in the Japanese FK506 study. Although it was discontinued in two patients within two months because of adverse effects and acute rejection, seven other patients tolerated the agent for a long period and received the drug three times a day. Concomitant prednisolone was gradually tapered and finally withdrawn in these patients. RESULTS: The smaller dosage of tacrolimus led to a higher trough concentration of 14.1 +/- 1.6 ng/mL in the three-times-a-day regimen compared with 12.7 +/- 1.9 ng/ml in twice-a-day therapy (P < 0.01). The daily dosage of tacrolimus proved to be reducible even further. Our target trough concentration was decreased finally to < 5 ng/mL. Concomitant prednisolone was withdrawn in all of the seven patients. The course of these patients has been uneventful for a year after withdrawal of prednisolone. CONCLUSION: Our regimen of three-times-a-day oral administration of tacrolimus is a likely protocol for reduction of its daily dosage, which lowers its adverse effects while maintaining its immunosuppressive action at a lower trough concentration without concomitant prednisolone.
The pancreatic beta- and alpha-cells are developmentally related to each other but reveal diverse gene expression patterns. Among the two important transcription factors for insulin gene expression, IEF1 is present both in alpha- and beta-cells, but PDX-1/IPF1/STF-1/IDX-1, a homeodomain-containing transcription factor, is present in beta-cells but not in alpha-cells. To elucidate the function of PDX-1 in the expression of beta-cell-specific genes, we established stable alphaTC1 clone 6 (alphaTC1.6)-derived transfectants expressing PDX-1 and examined the changes in the gene expression patterns in them. The exogenous expression of PDX-1 in alphaTC1.6 cells alone could induce islet amyloid polypeptide (IAPP) mRNA expression in the cells but not the expression of insulin, glucokinase, or GLUT2 gene. However, when betacellulin was added to the medium, the PDX-1-expressing alphaTC1.6 cells, but not the control alphaTC1.6 cells, came to express insulin and glucokinase mRNAs. This did not occur with other growth factors such as epidermal growth factor, transforming growth factor alpha, and insulin-like growth factor I. GLUT2 mRNA remained undetectable in the PDX-1--expressing alphaTC1.6 cells. These observations demonstrate the potency of PDX-1 for the expression of the insulin, glucokinase, and IAPP genes and suggest that certain regulatory factors, which can partially be modified by betacellulin, also contribute to the beta-cell specificity of gene expression.
BACKGROUND: Risk factors to induce graft dysfunction during pregnancy in kidney transplant recipients were studied. METHODS: A total of 28 deliveries from 21 female kidney transplant recipients were analyzed. RESULTS: All recipients were maintained on either azathioprine-based (n = 17) or cyclosporine-based (n = 11) immunosuppressive regimens. Graft dysfunction (creatinine clearance < 40 ml/min) occurred in 8 cases (8 patients) during pregnancy. No acute rejection, however, could be observed. In a case-controlled study comparing a group with graft dysfunction vs. a group with good graft function, there were significantly differences in the incidence of the cases with pre-existing hypertension (62.5% vs. 10.0%), the age of the grafted kidney (58.1 vs 47.6 year), the maternal anemia (Hb: 10.3 vs. 11.8 g/dl) and the creatinine level (1.4 vs. 1.0 mg/dl) at the first trimester. These findings suggested that poorer graft function had been underlying before pregnancy and that additional loading of the pregnancy reduced further graft function, while the deterioration would be recovered after delivery in all cases except one case. CONCLUSION: Risk factors to induce graft dysfunction during pregnancy are as follows. 1) high age of the grafted kidney (> 50 year), 2) pre-existing hypertension, 3) maternal anemia (Hb: < 11 g/dl) and 4) high creatinine level (> 1.3 mg/dl) at the first trimester.
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To elucidate the clinical significance of antibodies to glutamic acid decarboxylase (GAD Ab) compared to islet cell antibodies (ICA) in recent-onset and long-standing insulin-dependent diabetes mellitus (IDDM). We examined GAD Ab and ICA in 29 recent-onset and 85 long-standing patients with IDDM. GAD Ab was detected by a radioimmunoassay kit using purified pig brain GAD as an antigen. The prevalence of GAD Ab in the recent-onset diabetic patients was 55.2%, slightly lower than that of ICA (65.5%). In contrast, the prevalence of GAD Ab in long-standing diabetic patients was 42.4%, which was significantly higher than that of ICA (23.5%) (p < 0.01). GAD Ab were consistently detected in approximately 40% of patients with long-standing disease, while ICA decreased according to duration of disease. The GAD Ab titer in ICA-positive patients (mean +/- SD, 1588.2 +/- 6755.1; range, 6-38574) was significantly higher than that in ICA-negative patients (mean +/- SD, 13.4 +/- 17.9; and range, 5-72 units) (p < 0.001). These findings suggest that GAD Ab are more useful than ICA to know participation of immune disorders in long-standing patients with IDDM.
Glucose-6-phosphatase (G6Pase) plays a major role in gluconeogenic pathway. To analyze its regulation, we have cloned a full-length cDNA for G6Pase catalytic subunit from the rat liver. In the cloned cDNA, a 492 base insertion, respective to the previously reported sequence, was found in the 3'-noncoding region. In both ends of this insertion, 5'- and 3' 2' splice site motifs were identified. However, spliced mRNA was hardly observed in the rat RNA. Abundant expression was observed in the liver and the kidney by Northern analysis. Expression was also observed in the spleen, adrenal gland and small intestines. Reverse-transcription (RT) polymerase chain reaction (PCR) analysis revealed that G6Pase mRNA was also expressed in a variety of tissues including pancreatic islets. Its expression was increased in the ketotic diabetic mice livers and was corrected by insulin treatment. However, no appreciable changes were observed in kidneys. Broad tissue distribution in expression and the tissue specificity in regulation were thus considered to be the important features of G6Pase gene.
Giant hydronephrosis is an uncommon clinical entity. Even more uncommon is the association of giant hydronephrosis with a double collecting system and ectopic ureter. Here, we report a case of giant hydronephrosis of the bilateral duplex systems associated with ureteral ectopia. The patient underwent upper pole nephrectomy and upper ureterectomy. To our knowledge, only four similar cases have been reported previously.
A mutation in the hepatocyte nuclear factor-4 alpha (HNF-4 alpha) gene has been recently reported to cause maturity-onset diabetes of the young (MODY) (Yamagata, Furuta, et al., 1996). The mutation can also be a good candidate for the responsible gene of non-insulin dependent diabetes mellitus (NIDDM). The existence of the mutated allele of Q268X (C to T substitution within the exon 7 of HNF-4 alpha gene) was searched in 514 alleles of Japanese NIDDM patients by polymerase chain reaction-restriction fragment length polymorphism analysis. No mutation was found in these patients. The result showed that the Q268X mutation of HNF-4 alpha gene was not frequent among general NIDDM patients and that it cannot serve as the major diabetogenic gene in the Japanese ethnic group.
A mouse with juvenile visceral steatosis (the JVS mouse) has been recognized as a novel animal model for systemic carnitine deficiency. We examined cardiac, skeletal and smooth muscle cells in JVS and control mice by light and electron microscopy. Cardiac and skeletal muscle cells of these mice at 4 weeks of age exhibited a ragged-red appearance after trichrome staining. Electron microscopy, demonstrated increased numbers of mitochondria and lipid droplets in the cells. Compression or distortion of the myofibril bundles, primarily due to the increased number of mitochondria, suggests the possible existence of a functional disturbance of the cardiac and skeletal muscle. In the urinary bladder, only one or two large lipid droplets and slightly increased number of mitochondria were recognized in the perinuclear region of the smooth muscle cells. At 8 weeks of age, the mouse enzyme histochemistry specific for mitochondria, such as cytochrome c oxidase and succinic dehydrogenase, and oil red O staining, confirmed further increases in the number of mitochondria and lipid droplets in the heart. However, the accumulation of these organelles in the skeletal and smooth muscle cells was no greater than that noted in JVS mice at 4 weeks of age. In the cardiac muscle cells, autolysosomes or autophagic vacuoles containing electron-dense membranous, lamellar or whorled structures closely associated with mitochondria and pseudoinclusion bodies in the nucleus were recognized, and bundles of myofibrils were buried under numerous mitochondria, suggesting the existence of disturbed contractile function in the heart of JVS mice. These results indicate that this murine strain associated with systemic carnitine deficiency exhibits a generalized mitochondrial abnormality in the muscle system especially in the heart.
The currently study focused on the influence of delayed graft function on the long-term graft success rate in cadaver kidneys without any mismatches for HLA-DRB1. Donor-recipient HLA-DRB1 was determined by the significant two-locus linkages of HLA-B and -DRB1. The overall 5-year graft success rate was 88% in an HLA-DRB1-compatible group, significantly higher than the 69% in an HLA-DRB1 mismatch group (P < 0.05) and the 66% in an HLA-DR mismatch (P < 0.01). Delayed graft function was observed in 182 of 223 transplants. This high incidence of 82% is due to the fact that, in Japan, kidney procurement may only occur after cardiac arrest. The incidence did not differ in each group. The 5-year success rate for grafts with delayed function was 87% in the HLA-DRB1-compatible group, again significantly superior to the 68% in the HLA-DRB1 mismatch group and the 63% in the HLA-DR mismatch cases (P < 0.05). There was, thus, no difference in graft success rate for each group, with or without delayed graft function. Consequently, we feel that delayed graft function has no impact on the long-term outcome in transplants without mismatches for HLA-DRB1.
Viral infection is assumed to trigger or exacerbate autoimmune responses against pancreatic beta cells leading to the development of insulin-dependent diabetes mellitus (IDDM). We therefore examined by polymerase chain reaction the presence of two candidate viruses, cytomegalovirus and Epstein-Barr virus, in IDDM pancreases. Pancreas tissues were obtained by biopsy under laparoscopy from 16 recent-onset IDDM patients: age 17-53 years; disease duration 0-7 months; six had flu-like symptoms before onset. Frozen sections were made and subjected to DNA amplification. DNA samples were prepared from the frozen sections and polymerase chain reaction was performed using primers specific to cytomegalovirus, Epstein-Barr virus and control gene for HLA-DP. Cytomegalovirus- and Epstein-Barr virus-infected cells were used for positive control. Southern blot analysis could detect cytomegalovirus DNA from as few as 2 x 10(-1) cytomegalovirus-infected cells and Epstein-Barr virus DNA from two Epstein-Barr virus-infected cells. This highly sensitive analysis, however, could not detect cytomegalovirus or Epstein-Barr virus genomes in pancreases of recent-onset IDDM. A single copy human gene (HLA-DP) was amplified from all IDDM pancreases indicating that DNA amplification was performed without inhibition. We conclude that cytomegalovirus or Epstein-Barr virus genomes are unlikely to exist in pancreas biopsy specimens of recent-onset IDDM patients.
To elucidate the role played by interferon-alpha (IFN alpha) in the pathogenesis of autoimmune endocrine disease, we determined the autoantibody status, thyroid function test results, hemoglobin-A1c levels, and clinical symptoms of 58 patients who received IFN alpha for treatment of chronic active type C hepatitis. Each patient was treated for 6 months with a total dose of 391 +/- 140 x 10(6) U (mean +/- SD). Thyroid microsomal and/or thyroglobulin antibodies newly appeared or were increased in titer in 6 patients, 2 of whom developed hypothyroidism during IFN alpha therapy. Neither islet cell antibodies nor insulin-dependent diabetes mellitus developed during IFN alpha therapy, although hemoglobin-A1c levels were increased in 2 patients. One patient became positive for antimitochondrial antibodies, and another patient with preexisting antimitochondrial antibodies also manifested deterioration in liver function test results. Parietal cell antibodies and smooth muscle cell antibodies were the most frequent newly developed antibodies in 7 patients. Adrenal medullary cell antibodies and nuclear antibodies newly developed in 2 and 1 patients, respectively. At least 1 of 8 autoantibodies newly appeared in 19 patients (32.8%) and hypothyroidism developed in 2 patients (3.4%) during IFN alpha therapy. On the other hand, in 19 age- and sex-matched patients who did not receive IFN alpha, no autoantibody appeared, and no autoimmune disease developed during a follow-up period of 3 months. These findings suggest that IFN alpha acts as an immunomodulatory agent, inducing autoantibody production and the development of autoimmune disease in susceptible patients. Special attention should be paid to the development of hypothyroidism during IFN alpha therapy.
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Islet cell antibodies (ICA) are a marker of insulin-dependent diabetes mellitus (IDDM). ICA are detected in 60-80% of the patients with IDDM at the onset of the disease. The presence of ICA in patients with non-insulin-dependent diabetes mellitus (NIDDM) indicates that the patients are likely to develop IDDM. However, as ICA are measured by the indirect immunofluorescent method, the reliability of the ICA assay is not high in some institutes. Use of the pancreas tissue having high antigenicity is recommended as one solution for a reliable assay. Standardization of the ICA assay is under way with the use of an ICA positive standard sera as 80 JDF units. Anti-glutamate decarboxylase (GAD) antibody assays using a radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA) have recently been developed. The significance of anti-GAD antibodies is comparable to that of ICA. Since the anti-GAD assay is reproducible and easy to perform, it should be used widely in parallel with the ICA assay.