Mutations in the hepatocyte nuclear factor-4alpha gene in Japanese with non-insulin-dependent diabetes: a nucleotide substitution in the polypyrimidine tract of intron 1b.

Mutations of the hepatocyte nuclear factor 4 alpha (HNF-4alpha) gene have been demonstrated in maturity-onset diabetes of the young (MODY) 1 families. To investigate the possibility that the HNF-4alpha gene contributes to the onset of non-insulin-dependent diabetes mellitus (NIDDM) in Japanese patients, we screened all exons and flanking introns of this gene for mutations in 100 patients with NIDDM diagnosed after 25 years of age. We identified two missense mutations: M49V in exon 1c and T1301 in exon 4; and two nucleotide substitutions in introns: cytosine to thymidine at -5 nt in intron 1b and adenine to thymidine at -21 nt in intron 5. We screened an additional 220 diabetic subjects for the polymorphism in intron 1b. The c/t substitution in intron 1b was associated with NIDDM. This substitution in the polypyrimidine tract, an important cis-acting element directing intron removal, is likely to influence pre-mRNA splicing of this gene. T1301 in exon 4 was observed in only two diabetic subjects. This mutation could influence the conformation of this peptide, resulting in changes in ligand binding domain function. M49V in exon 1c was found in both diabetic and non-diabetic subjects; isoforms HNF-4alpha 4, 5, and 6 with this mutation may impair glucose metabolism in tissue. In contrast to the primary cause of nonsense and missense mutations of the HNF-4alpha gene in MODY1, the nucleotide substitution in intron 1b may partially contribute to development of NIDDM in combination with other genetic and environmental factors.     

Hydrogen Peroxide-dependent Synthesis of Flavonols in Mesophyll Cells of Vicia faba L.

Mesophyll cells of Vicia faba contain kaempferol and quercetinglycosides. When isolated mesophyll cells were treated with0.1 mM H₂O₂ for 2 h, the levels of these flavonols increasedby 10–70% of the control values (mean values, 19.6% and34.4% for kaempferol and quercetin glycosides, respectively).Such increases in levels of flavonols were also observed inisolated vacuoles of mesophyll cells. However, when mesophyllcells and vacuoles were treated with 10 mM H₂O₂₎degradationof flavonols was observed. These data suggest that H₂O₂ hastwo effects on the metabolism of flavonols: induction of theirsynthesis and stimulation of their oxidation. (Received March 6, 1989; Accepted July 10, 1989)     

False positive reaction for carcinoembryonic antigen in paget cells

Virchows Archiv B Cell Pathology - Paget cells from cases of mammary and extramammary Paget’s disease were examined for carcinoembryonic antigen (CEA) and CEA-related antigens by the...     

Immunohistochemical characteristics of the constituents of senile plaques and amyloid angiopathy in aged cynomolgus monkeys

Abstract: In this study, we immunohistochemically examined the several constituents of senile plaques (SPs) and cerebral amyloid angiopathy (CAA) in aged cynomolgus monkeys. Apolipoprotein E (apoE) deposited in all mature plaques and CAA, and in half of the diffuse plaques. Alpha-1-antichymotripsin (αACT) deposited in half of the mature plaques and in one third of the CAA. Amyloid precursor protein (APP), ubiquitin (Ub), and microtubule-associated protein-2 (MAP-2) accumulated in the swollen neurites of mature plaques. Glial fibrillary acidic protein (GFAP) was detected in the astrocytes and their processes surrounding the mature plaques. Tau was detected in neither the SPs nor CAA. Therefore, mature plaques involved extracellular Aβ, apoE, and αACT, and also astrocytes and swollen neurites. However, diffuse plaques involved only extracellular Aβ and apoE. Since these features, except for tau, were consistent with those in humans, this animal model will be useful for studying the pathogenesis of cerebral amyloid deposition.     

Ligand recognition in μ opioid receptor: experimentally based modeling of μ opioid receptor binding sites and their testing by ligand docking

For three-dimensional understanding of the mechanisms that control potency and selectivity of the ligand binding at the atomic level, we have analysed opioid receptor-ligand interaction based on the receptor's 3D model. As a first step, we have constructed molecular models for the multiple opioid receptor subtypes using bacteriorhodopsin as a template. The S-activated dihydromorphine derivatives should serve as powerful tools in mapping the three-dimensional structure of the μ opioid receptor, including the nature of the agonist-mediated conformational change that permits G protein-coupling to ‘second messenger’ effector molecules, and in identifying specific ligand-binding contacts with the μ opioid receptor. The analyses of the interactions of some opioid ligands with the predicted ligand binding sites are consistent with the results of the affinity labeling experiments.     

Regulatory mechanism of delayed-type hypersensitivity in mice. II. Effect of suppressor cells on the development of memory cells for delayed-type hypersensitivity

Murine lymph node cells (LNC), which we showed previously to noncompetitively inhibit antibody-dependent cellular cytotoxicity (ADCC) to an erythrocyte target, were tested for their ability to inhibit ADCC to a tumor target, EL-4. Both a 4-hr ⁵¹Cr-release cytotoxicity assay and an overnight ¹²⁵IUdR (iododeoxyuridine) postlabeling cytostasis assay were used. Normal autologous lymph node cells inhibited spleen cell-mediated ADCC in both assays. Inhibition by LNC was dose dependent, but comparable numbers of sheep erythrocytes did not inhibit, indicating that LNC-mediated inhibition was not simply a matter of crowding. Inhibitory activity was enriched in LNC after removal of Fc receptor-bearing cells on EA monolayers.     

Immunogenicity of lysozyme derivatives lipid-conjugated to various degrees in mice treated with and without cyclophosphamide: dissociation of delayed-type hypersensitivity and helper function.

Lysozyme and a series of its lipid-conjugated derivatives without adjuvant were examined in mice for their abilities to induce delayed-type hypersensitivity (DTH), helper T-cell activity, and antibody formation. In addition, the effect of cyclophosphamide (CY) on the immune responses was assessed in mice immunized with these lysozyme derivatives. Precipitated lysozyme without lipid conjugation was a good inducer of both antibody and DTH responses. Lipid conjugation to lysozyme to intermediate degrees readily caused the failure only in inducing the antibody response. As lysozyme was lipid-conjugated more heavily, DTH response was also reduced and finally abolished. In contrast, the helper activity was little affected by any degree of lipid conjugation. These results indicate that the helper T-cell activity was dissociated from the both DTH response and the antibody production. CY pretreatment extensively enhanced DTH response induced by such lipid-conjugated derivatives that failed to induce antibody response. Furthermore, CY pretreatment in doses in a wide range enhanced not only DTH response but also antibody formation. It is, therefore, concluded that the enhancement of DTH response by CY does not necessarily entail suppression of antibody formation.