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Biomedical subjects

M Ogata

Publications and source records attributed to M Ogata.

At least 109 records · Page 6Linked to original sources

Liver and kidney function in Japanese patients with maturity-onset diabetes of the young.

OBJECTIVE: Heterozygous mutations in the transcription factors hepatocyte nuclear factor (HNF)-1 alpha, HNF-1 beta, and HNF-4 alpha are associated with maturity-onset diabetes of the young (MODY) and are believed to cause this form of diabetes by impairing pancreatic beta-cell function. The HNFs also play a central role in the tissue-specific regulation of gene expression in liver and kidney, suggesting that patients with MODY due to a mutation in HNF-1 alpha, HNF-1 beta, or HNF-4 alpha may exhibit abnormal liver or kidney function. Here, we have examined liver and kidney function in a series of Japanese patients with HNF-4 alpha/MODY1, HNF-1 alpha/MODY3, and HNF-1 beta/MODY5 diabetes. RESEARCH DESIGN AND METHODS: Clinical and biochemical data were obtained from Japanese subjects with HNF-1 alpha, HNF-1 beta, and HNF-4 alpha diabetes. The clinical data included information on BMI, age at diagnosis, current treatment, and the presence and nature of any complications. The biochemical studies examined liver and kidney function and included measures of alanine and aspartate aminotransferase, gamma-glutamyl transpeptidase, blood urea nitrogen, creatinine, uric acid, total and HDL cholesterol, triglycerides, and 17 serum proteins. RESULTS: The present age and duration of diabetes were similar in patients with HNF-1 alpha, HNF-1 beta, or HNF-4 alpha diabetes, as was the age at diagnosis of diabetes in the youngest generation. All subjects were lean. Of the subjects with HNF-1 alpha and HNF-4 alpha diabetes, 50% were treated with insulin, as were all three subjects with HNF-1 beta diabetes. Retinopathy was present in patients with each form of diabetes. None of the subjects with HNF-4 alpha diabetes had evidence of nephropathy, whereas 36% of the patients with HNF-1 alpha diabetes and 100% of those with HNF-1 beta diabetes showed diminished kidney function. The three subjects with HNF-1 beta diabetes also had abnormally high serum creatinine, uric acid, and blood urea nitrogen levels, which are consistent with impaired kidney function, and one of seven subjects with HNF-1 alpha diabetes had a mild elevation in creatinine and blood urea nitrogen levels. These values were within the normal range in the three patients with HNF-4 alpha diabetes. Although the HNFs play a role in regulating the expression of the genes for most, if not all, serum proteins, there was no decrease in the levels of any of the 17 serum proteins examined, and most were within or slightly above the normal range. Lipoprotein(a) [Lp(a)] levels were elevated in the three patients with HNF-4 alpha diabetes and in one patient with HNF-1 beta diabetes, and in a second patient with HNF-1 beta diabetes, Lp(a) was at the upper limit of normal. CONCLUSIONS: The results indicate that as in white patients, MODY resulting from mutations in the HNF-1 alpha, HNF-1 beta, and HNF-4 alpha genes in Japanese patients may be a severe disease similar to classic type 2 diabetes. In addition, they suggest that patients with HNF-1 beta diabetes may be characterized by diminished kidney function and perhaps abnormal liver function. Further studies are needed to determine whether tests of liver and kidney function will be useful in the diagnosis and subclassification of MODY.

Adolescent↗

[Lymphoma associated hemophagocytic syndrome with plasmacytosis in the bone marrow and hypergammaglobulinemia].

A 72-year-old woman was admitted to our hospital because of fever, anemia and thrombocytopenia in March 1997. Laboratory findings showed elevated serum LDH levels and polyclonal gammopathy. Bone marrow aspiration samples revealed hemophagocytosis and plasmacytosis. Although serum interleukin-6 was elevated, serum interferon-lambda and tumor necrosis factor-alpha were below detectable limits. Magnetic resonance images disclosed a tumor in the patient's pelvic cavity. The tumor was resected and diagnosed as non-Hodgkin's lymphoma. The patient was treated with combination chemotherapy and has remained in complete remission. Also, histiocyte and plasma cell counts in the bone marrow fell significantly and the serum interleukin-6 level returned to the normal range. We reasoned that lymphoma cells may have induced plasmacytosis in the bone marrow and polyclonal gammopathy accompanied by hemophagocytic syndrome.

Aged↗

Immunohistochemical diagnosis and significance of forensic neuropathological changes.

Immunohistochemistry is very useful when investigating the cause of death. Ischemic cell changes in the hippocampal neurons were not obvious in the brains damaged by hypoxic injury. However, it is suggested that even a moderate hypoxia, which may affect the neuronal proteins and metabolism, induced astrocytosis in the CA3 and CA4 regions, and that in patients with a history of hypoxic attacks neuronal damage may be severe even several hours after ischemic injury. Furthermore, hsp70 expression was found in the CA2, CA3 and CA4 regions of long-term survivors after severe hypoxic/ischemic injury. In forensic practice, detailed information about the duration and extent of a hypoxic/ischemic injury is often unavailable, so that immunohistochemical detection of hsp70 and glial cell staining can be of great value in diagnosing not only the hypoxic/ischemic injury during the process of death but also the victim's past history of hypoxic attacks. In diffuse axonal injury, degeneration of axon and myelin, such as swelling and waving, were observed in survivors of more than 8 hours. Retraction balls appeared in survivors of more than 1 days. In longer term survivors, such as 3 or 5 months, breakdown of myelin and fat-granule cells were observed. In addition, retraction balls were also found. Immunohistochemical staining of 200 kD neurofilament was a very useful method to examine axonal changes, because antisera is specific for degenerative neurofilaments. In our study, all cases which had pathological findings of diffuse axonal injury (DAI) were associated with focal head injuries. From the immunohistochemical staining of neurons in the hippocampus, it was suggested that neurons in the hippocampus were injured by diffuse brain damage. Furthermore, repairing and protective mechanisms occurred especially from CA2 to CA4. It was considered that neuronal damage in diffuse brain injury was elucidated not only morphologically but also functionally. Therefore, in cases of suspected diffuse brain damage, it is recommended to examine the neuronal changes in addition to observing the findings of diffuse axonal injury. Immunohistochemical staining of the carotid body is potentially very useful for necropsy diagnosis, since it provides a method to detect evidence of mechanical asphyxia in suspected cases of manual and/or ligature strangulation.

Biomarkers↗

[A 63-year-old man with progressive cauda equina/conus medullaris syndrome].

A 63-year-old man, whose father died of malignant lymphoma, developed subacutely cauda equina/conus medullaris syndrome progressed over 3 months. Initial radicular pain, ascending motor and sensory paralysis without sacral sparing, vesicorectal dysfunction were similar with signs of spinal dural arteriovenous fistula. However, mild inflammatory signs, raised serum LDH, predominantly of LDH 3, lymphocytic pleocytosis and elevated beta 2 microglobulin in CSF suggested neurolymphomatosis. It was not supported, however, after CSF immunocytochemistry, myelogram, CT, Gd-MRI and Ga scan. Spinal cord/nerve root vascular syndromes of intravascular lymphomatosis (IVL) according to Glass J et al. was suspected because of the unique neurological progression similar to Foix-Alajouanine syndrome, hypoxia without abnormalities in chest X-ray film, response to steroids and raised serum soluble IL-2 receptor. Multiple biopsies were performed with negative results. However, after all muscle biopsy confirmed IVL. The lower spinal irradiation was not effective. But CHOP regimen supplemented by granulocyte colony-stimulating factor (G-CSF) brought about swift neurological improvement and protection from late complications. Self-limiting polyneuropathy emerged during the biweekly CHOP therapy, 6 courses for 12 weeks. Eventually he was neurologically improving 10 months after the chemotherapy and adrenal enlargement, which was possibly of metastasis, was only against complete remission. This case was good outcome by biweekly CHOP using G-CSF when compared with very high mortality in reported IVL cases besides vincristine neurotoxicity under compromised blood-brain/nerve barrier due to IVL might affect the functional recovery. This case with IVL implied raised soluble IL-2 receptor and progressive cauda equina syndrome/ascending myelopathy as diagnostic clues, and efficiency of muscle biopsy to confirm IVL.

Cauda Equina↗

Isolation and characterization of a thiamin transport gene, THI10, from Saccharomyces cerevisiae.

We isolated a thiamin transporter gene, THI10, from a genomic library of Saccharomyces cerevisiae by the complementation of a yeast mutant defective in thiamin transport activity. The THI10 gene contained an open reading frame of 1,794 base pairs encoding a 598-amino acid polypeptide with a calculated molecular weight of 66, 903. The nucleotide sequence of THI10 is completely identical to that of an anonymous DNA (open reading frame L8083.2) mapped to chromosome XII; two other genes (open reading frames YOR071c and YOR192c) in chromosome XV are extremely similar to THI10. Moreover, the THI10 gene product showed significant sequence homology with yeast allantoin and uracil transporters. Hydropathy profile suggested that THI10 product is highly hydrophobic and contains many transmembrane regions. Gene disruption of the THI10 locus completely abolished the thiamin transport activity and thiamin binding activity in yeast plasma membrane fraction. Both the transport and thiamin binding activities were restored in the disrupted cells when the THI10 open reading frame was expressed by yeast GAL1 promoter, suggesting that the THI10 gene encodes for the thiamin transport carrier protein. Northern blot analysis demonstrated that THI10 gene expression is regulated at the mRNA level by intracellular thiamin pyrophosphate and that it requires a positive regulatory factor encoded by THI3 gene.

Amino Acid Sequence↗

Advanced glycation end products induce expression of vascular endothelial growth factor by retinal Muller cells.

Recent studies have suggested that advanced glycation end products (AGEs) are involved in the development of diabetic complications. To assess the pathogenic role of AGEs and vascular endothelial growth factor (VEGF) in the development of retinal neovascularization in diabetic retinopathy, we investigated the effect of AGEs on induction of VEGF by retinal Muller cells and measured AGE and VEGF concentrations in the vitreous of patients with proliferative diabetic retinopathy (PDR) and nondiabetic patients. The expression of VEGF mRNA and the production of VEGF protein by cultured Muller cells were enhanced by the presence of AGEs. The vitreous concentrations of AGEs and VEGF were both elevated in patients with PDR compared with patients without diabetes (P < 0.01). There was a moderate positive correlation between the levels of crossline and VEGF (r=0.698, P < 0.01). Elevation of AGEs in the vitreous may promote intraocular neovascularization in diabetic retinopathy through production of VEGF from Muller cells.

Aged↗

Large-scale biological monitoring in Japan.

Data from the large-scale biological monitoring program in Japan were assembled and analyzed and the following results were obtained. All workers handling lead and eight kinds of major organic solvents received physical examinations and biological monitoring at the same time. Therefore, the number of workers handling industrial chemicals and that received physical examinations and the number of workers been examined by biological monitorings were similar to each other. The total number of cases examined from 1989 to 1994 was about 661,000 for lead in the blood and about 4,173,000 for the urinary metabolites of eight organic solvents. The results were classified into three categories and category 3 consists of workers having exposure concentrations above the 1988-1989 biological exposure indices of the ACGIH with the exception of lead concentration in the blood where the limit in Japan was set at 40 micrograms/100 ml. The percentage of exposed workers in category 3 was 1.4% for blood lead and 0.2-2.4% for the urinary metabolites of the eight organic solvents. The percentage of exposed workers in category 3 for blood lead, delta-aminolevulinic acid, urinary mandelic acid, N-methylformamide and 2,5-hexanedione in the urine has decreased with time. In ambient monitoring, the percentage of workplaces in classification 3 for lead and styrene also has decreased with time.

Aminolevulinic Acid↗

Effects of ion channel blockers on rapid postmortem changes in extracellular dopamine and serotonin levels in the rat nucleus accumbens.

In the present study, we used in vivo brain microdialysis to examine the effects of ion channel blockers tetrodotoxin (TTX), EGTA-free Ca2+ and verapamil on rapid postmortem changes in extracellular levels of dopamine (DA), serotonin (5-HT) and their metabolites dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) in the ACC of freely moving rats. Extracellular ACC DA levels decreased following the perfusion of the three ion channel blockers in freely moving rats, and then, at death by cervical dislocation, maximum respective 220-, 60- and 90-fold increases were observed in the extracellular output of DA in animals treated with EGTA, verapamil and TTX, respectively. Also, ACC 5-HT decreased following perfusion with the three blockers in the freely moving rats, and then maximum increases of 80-, 30- and 45-fold in the extracellular output of 5-HT were observed at death in animals treated with EGTA, verapamil and TTX, respectively, compared to the baseline. Cervical dislocation-induced rapid postmortem changes were inhibited markedly by perfusion with CSF containing the CA2+ entry blocker verapamil. These observations suggested that rapid postmortem changes in ACC DA and 5-HT release were associated with the action of calcium ion channels and/or voltage gated channels in the CNS.

Animals↗

DNA fragmentation is not the primary event in glucocorticoid-induced thymocyte death in vivo.

Thymocyte death has been recognized as one of the best models for studying apoptosis. Our recent study, however, indicated that most thymocytes die without DNA fragmentation and become terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling-positive (TUNEL+) only after being phagocytosed by macrophages. In this study, we used histological techniques using the TUNEL method, histochemistry, immunohistochemistry, and transmission electron microscopy as well as flow cytometry to examine in vivo the effect of glucocorticoid (GC), a well-known agent for inducing thymocyte apoptosis in vitro, on thymocyte death to determine whether or not DNA fragmentation was the first event of GC-induced thymocyte death. At 2 h and 4 h after GC injection, a large number of cortical thymocytes were TUNEL+. Most TUNEL+ cells were aggregated to form clusters. Double staining of the section showed that the TUNEL+ thymocytes were phagocytosed by acid phosphatase+ and Mac-2+ macrophages. An ultrastructural study indicated that a far greater number of small pyknotic thymocytes were present in the cortex of the GC-treated thymus than were observed in the control thymus, that all those pyknotic thymocytes were TUNEL-, and moreover, that at the electron microscopic level, TUNEL+ cells were all phagocytosed by macrophages. Flow cytometric analysis did not detect a single TUNEL+ thymocyte even 4 h after the GC treatment, suggesting that virtually no free dead thymocytes were present after DNA fragmentation. These results indicate that, consistent with our previous findings with normal thymocyte death and B cell death in the germinal centers, DNA fragmentation is not involved in the cell death process of the GC-induced rapid thymocyte death in vivo.

Animals↗

A pancreatic pseudocyst with pancreatic pleural effusion: report of a case.

A 54-year-old man with a 30-year history of chronic alcoholism was admitted to our hospital suffering from dyspnea and left-sided chest pain. A chest radiograph revealed pleural effusion. Computed tomography revealed a pancreatic pseudocyst in the tail of the pancreas spreading out to the posterior mediastinum and the left pleural cavity. The laboratory findings of pleural effusion were as follows: amylase, 118,400 IU/1; protein, 4.6 g/dl; class I in cytology. Despite a reduction in the pleural effusion by conservative therapy, left back pain and a recurrence of the pleural effusion were observed after oral intake was re-initiated. A distal pancreatectomy and ligation of the pancreaticopleural fistula were thus performed on the 75th hospital day. The patient made a complete recovery from pancreatic pleural effusion and has now been well for 9 years.

Chronic Disease↗

Hemolytic uremic syndrome following autologous peripheral blood stem cell transplantation in a patient with malignant lymphoma.

Hemolytic uremic syndrome (HUS) has been reported in patients receiving bone marrow transplantation. However, only a few cases of HUS following autologous peripheral blood stem cell transplantation (PBSCT) have been reported. We present a case of HUS developing after autologous PBSCT in a 40-year-old man with non-Hodgkin's lymphoma. It appears that the chemotherapeutic agents administered during the conditioning regimen for PBSCT may have played an important role in the development of HUS in our patient. In the present case, the combination therapy of vincristine, methylprednisolone, and ticlopidine hydrochloride was effective.

Adult↗

Subunit composition of the pre-T-cell receptor complex analysed by monoclonal antibody against the pre-T-cell receptor alpha chain.

The pre-T-cell receptor (TCR) complex, which consists of a heterodimer of the TCR beta-chain and the pre-TCR alpha-chain, is known to regulate early thymocyte development. The pre-TCR complex contains CD3 subunits as a signal-transducing molecule, but the exact subunit composition of the fully assembled pre-TCR complex remains to be elucidated. In particular, the association of the CD3 zeta-chain with the pre-TCR is controversial. In the present study, we have generated a monoclonal antibody against the cytoplasmic portion of the pre-TCR alpha-chain, and analysed a subunit composition of the pre-TCR complex. We demonstrated that the CD3 zeta-chain is physically associated with the pre-TCR in immature T cells. Thus, the result strongly supports the previous findings that CD3 zeta contributes to signalling mediated through the pre-TCR complex.

Animals↗

A novel peptide-IgG conjugate, CAP18(106-138)-IgG, that binds and neutralizes endotoxin and kills gram-negative bacteria.

Although type-specific IgG directed to the O-polysaccharide antigen of bacterial lipopolysaccharide (LPS) is protective in most models of LPS or bacterial challenge, no currently available IgG binds to LPS from all gram-negative bacteria. The ability of a peptide-IgG conjugate, CAP18(106-138)-IgG, to bind and neutralize LPS, to kill gram-negative bacteria, and to protect in a sensitized mouse model of LPS toxicity was studied. CAP18(106-138)-IgG bound LPS from multiple gram-negative bacteria in four different binding assays. In a fluid-phase RIA, half-maximal binding of 5 microg/mL 3H-labeled LPS occurred at 5-10 microg/mL CAP18(106-138)-IgG, similar to binding with monoclonal type-specific IgG. CAP18(106-138)-IgG neutralized LPS, as assessed by LPS-induced coagulation of limulus amebocyte lysate and production of tumor necrosis factor in vitro, was bactericidal for a wide range of gram-negative bacteria, and decreased LPS-induced lethality in sensitized mice. Antibacterial peptide-IgG conjugates merit further study as a novel adjunctive therapy for gram-negative sepsis.

Animals↗

Effect of anticoagulants on binding and neutralization of lipopolysaccharide by the peptide immunoglobulin conjugate CAP18(106-138)-immunoglobulin G in whole blood.

The 18-kDa cationic protein CAP18 is an antimicrobial protein isolated from rabbit granulocytes that binds lipopolysaccharide (LPS) and inhibits many of its biological activities. We covalently coupled a synthetic peptide representing amino acids 106 to 138 of CAP18 to human immunoglobulin G (IgG) by using the heterobifunctional linker N-succinimidyl-3-(2-pyridyidithio)propionate. The ability of CAP18(106-138)-IgG to bind and neutralize LPS in whole blood in the presence and absence of anticoagulants was studied. Both CAP18(106-138) and CAP18(106-138)-IgG significantly suppressed LPS-induced tumor necrosis factor (TNF) production in whole blood in the absence of anticoagulants. EDTA potentiated the ability of CAP18(106-138) and CAP18(106-138)-IgG to decrease LPS-induced TNF production in a dose-dependent manner. In contrast, heparin inhibited the ability of CAP18(106-138) and CAP18(106-138)-IgG to suppress LPS-induced TNF production. EDTA also enhanced LPS capture in a fluid-phase binding assay that utilizes magnetic anti-IgG beads to capture CAP18(106-138)-IgG (and bound [3H]LPS) in whole blood. In contrast, heparin inhibited the binding dose dependently. We conclude that CAP18(106-138)-IgG binds to and neutralizes LPS in whole blood in the absence of anticoagulants. Further studies of its protective efficacy in animal models are warranted. Caution should be used in interpreting assays that measure the binding and neutralization of LPS in whole blood in the presence of calcium-binding anticoagulants or heparin.

Animals↗