[Diagnosis and therapy of adult Still's disease].
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Biomedical subjects
Publications and source records attributed to M Yamaguchi.
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The Drosophila melanogaster gene and cDNA which span the entire open reading frame for DNA polymerase alpha, were cloned, and their nucleotide sequences were determined. The gene consists of 6 exons separated by 5 short introns. The major transcription initiation site was localized 85 bp upstream from the initiation codon. The nucleotide sequence of the open reading frame revealed a polypeptide of 1,505 amino acid residues with a molecular weight of 170,796. The amino acid sequence of the polypeptide was 37% homologous with that of the catalytic subunit of human DNA polymerase alpha. This sequence contains six regions, the orders and amino acid sequences of which are highly conserved among a number of other viral and eukaryotic DNA polymerases. We found 7 amino acid residues in the region between the 639th and 758th positions, identical to those essential for the active site of Escherichia coli DNA polymerase I-associated 3'----5' exonuclease. Thus, the exonuclease activity may be associated with Drosophila DNA polymerase alpha. Levels of the DNA polymerase alpha mRNA were high in unfertilized eggs and early embryos, relatively high in adult female flies and second-instar larva, and low in bodies at other stages of development. This feature of the expression is similar to that of the proliferating cell nuclear antigen (an auxiliary protein of DNA polymerase delta) and seems to coincide with the proportions of proliferating cells in various developmental stages. As the half life of the mRNA for DNA polymerase alpha in cultured Drosophila Kc cells was 15 min, expression of the DNA polymerase alpha gene is probably strictly regulated at the step of transcription.
The mitochondrial proton-translocating nicotinamide nucleotide transhydrogenase is embedded in the inner membrane as a homodimer of monomer Mr = 109,288. Its N-terminal 430 residues and C-terminal 200 residues protrude into the matrix, whereas its central 400 residues appear to intercalate into the inner membrane as 14 hydrophobic clusters of about 20 residues each (Yamaguchi, M., and Hatefi, Y. (1991) J. Biol. Chem. 266, 5728-5735). Treatment of mitoplasts (mitochondria denuded of outer membrane) with several proteolytic enzymes cleaves the transhydrogenase into a 72-kDa N-terminal and a 37-kDa C-terminal fragment. The cleavage site of proteinase K was determined to be Ala690-Ala691, which is located in a small loop of the transhydrogenase exposed on the cytosolic side of the inner membrane. This paper shows that the bisected transhydrogenase can be purified from proteinase K-treated mitoplasts with retention of greater than or equal to 85% transhydrogenase activity. The inactivation rate of the bisected enzyme by trypsin and N-ethylmaleimide was altered in the presence of NADP and NADPH, suggesting substrate-induced conformation changes similar to those reported previously for the intact transhydrogenase. Also, like the intact enzyme, proteoliposomes of the bisected transhydrogenase were capable of membrane potential formation and internal acidification coupled to NADPH----NAD transhydrogenation. The properties of the bisected transhydrogenase have been discussed in relation to those of the two-subunit Escherichia coli transhydrogenase, the bisected lac permease (via gene restriction), and the fragmented and reconstituted bacteriorhodopsin.
The effect of regucalcin, a calcium-binding protein isolated from rat liver cytosol, on Ca2+/calmodulin-dependent cyclic nucleotide (AMP) phosphodiesterase activity in rat liver cytosol was investigated. The addition of Ca2+ (50 microM) and calmodulin 160 U/ml in the enzyme reaction mixture caused a significant increase in cyclic AMP phosphodiesterase activity. This increase was inhibited by the presence of regucalcin (0.5-3.0 microM); the inhibitory effect was complete at 1.0 microM. Regucalcin (1.0 microM) did not have an appreciable effect on basal activity without Ca2+ and calmodulin. The inhibitory effect of regucalcin was still evident even at several fold higher concentrations of calmodulin (160-480 U/ml). However, regucalcin (1.0 microM) did not inhibit Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity in the presence of 100 and 200 microM Ca2+ added. Meanwhile, Cd2+ (25-100 microM)-induced decrease in Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity was not reversed by the presence of regucalcin (1.0 microM). The present results suggest that regucalcin can regulate Ca2+/calmodulin-dependent cyclic AMP phosphodiesterase activity due to binding Ca2+ in liver cells.
A substituted benzimidazole ([4-(3-methoxypropoxy)-3-methylpyridine-2-yl]methylsulfinyl)- 1H-benzimidazole sodium salt (E3810), is a gastric proton pump (H+, K(+)-ATPase) inhibitor. E3810 and omeprazole inhibited acid accumulation dose dependently as measured with aminopyrine uptake in isolated rabbit gastric glands, their IC50 values being 0.16 and 0.36 microM, respectively. The addition of exogenous reduced glutathione (GSH) to the gland suspension reactivated dose dependently the acid secretion which had been inhibited by 2 microM E3810 or omeprazole as a function of the incubation time. Furthermore, GSH at 1 and 3 mM reversed the antisecretory effect of E3810 more quickly than it did that of omeprazole. The antisecretory effect of E3810 was slightly greater than that of omeprazole in histamine-stimulated fistula dogs in vivo. The duration of the antisecretory activity of E3810 at concentrations of 2 and 4 mg/kg was shorter than that of omeprazole at the same concentrations in pentagastrin-stimulated fistula dogs. The reversal of the antisecretory activity of the inhibitors in dogs is suggested to be due to the action of endogenous extracellular GSH, in addition to de novo synthesis of the proton pump, because bullfrog gastric mucosae were found in the present study to secrete GSH into the mucosal solution at the rate of about 0.25 nmol/min/g tissue.
The sea urchin hatching enzyme (HEz) is a protease capable of dissolving the fertilization envelope that surrounds the embryo as a protective coat during early development. We have now purified a 37-kDa active enzyme from the supernatant fluid of hatched blastula medium of the species Hemicentrotus pulcherrimus. The purified enzyme was completely inhibited by alpha 2-macroglobulin and the chelating agents EDTA, EGTA, and 1,10-phenanthroline and was slightly inhibited by chymostatin and pepstatin, but was not inhibited by various other serine and thiol protease inhibitors. These results suggest that HEz is a metalloproteinase. Quantitative analyses of the products of HEz's action on various peptides revealed that the enzyme preferentially cleaved the peptide bonds on the amino side of bulky hydrophobic residues, -Leu, -Ile, and -Phe as well as -Tyr, in a similar but more limited fashion than thermolysin. Furthermore, although substance P was a good substrate of HEz, snake venom alpha-protease, and thermolysin, the analogue [Sar9]substance P was a poor substrate for HEz. This analogue was a good substrate for thermolysin and alpha-protease, but the scissile bonds were altered from those of substance P. The failure of HEz and alpha-protease to cleave the P1-P1 bond that meets the primary specificity is ascribed to the presence of an imino acid residue (proline or sarcosine) or the absence of any amino acid at the P2h or P3' position, in contrast to the simple P2' restriction of thermolysin.(ABSTRACT TRUNCATED AT 250 WORDS)
Eight sperm-activating peptides containing a novel amino acid were isolated from the egg jelly of the sea urchin Tripneustes gratilla. Accurate mass measurement of the peptide in FAB mass spectrometry showed that the mass of the novel amino acid residue was 224.978. On the basis of the isotopic ion distribution and the degree of unsaturation, the mass value indicated that the elemental composition of the amino acid residue was C9H8O1N1Br1, suggesting that the novel amino acid was bromophenylalanine. Proton NMR spectroscopy, amino acid analysis, and RP-HPLC with three synthetic isomers of bromophenylalanine demonstrated that o-bromophenylalanine was the novel amino acid. Derivatization of the amino acid with Marfey's reagent, (1-fluoro-2,4-dinitrophen-5-yl)-L-alanine amide (FDAA), further indicated that the amino acid was the L-isomer. In other sperm-activating peptides isolated from the egg jelly of the sea urchin, both m- and p-bromophenylalanines were discovered. The presence of m-bromophenylalanine has not been previously reported in natural products, while p-bromophenylalanine is found in theonellamide F, an antifungal bicyclic peptide from a marine sponge.
A high-performance liquid chromatographic method for the fluorometric determination of 1,2,3,4-tetrahydroisoquinoline in rat brain is described. 1,2,3,4-Tetrahydroisoquinoline and 4-phenylpiperidine (internal standard) are isolated by liquid-liquid extraction, and then converted into the corresponding fluorescent derivatives with 3,4-dihydro-6,7-dimethoxy-4-methyl-3-oxoquinoxaline-2-carbonyl chloride, a fluorescence derivatization reagent for amines. The derivatives are separated within 60 min on a reversed-phase column, TSK gel ODS-120T, with isocratic elution, and detected fluorometrically. The detection limit of 1,2,3,4-tetrahydroisoquinoline is 1.0 pmol/g in rat brain (S/N = 3).
Leukemia inhibitory factor/D-factor, a potent differentiation-inducing glycoprotein for murine myelomonocytic leukemic M1 cells, rapidly stimulated the phosphorylation of a 27 kDa protein with an isoelectric point of 5.6 in a LIF-sensitive M1-T22 cell line but not in a LIF-resistant M1-D(-) cell line. The increase in phosphorylation was detectable 5 min after LIF treatment and was maximal at 10 min. Heat shock treatment at 44.5 degrees C for 30 min also induced the phosphorylation of the same 27 kDa protein. Although this 27 kDa protein did not become labeled with [35S]-methionine, metabolic labeling experiments using [35S]-cysteine or [3H]-leucine clearly demonstrated that the synthesis of this protein was enhanced after heat shock. These results suggest that the phosphorylated 27 kDa protein is a low molecular weight stress protein and that the protein may play a role at an early stage in the LIF signaling pathway probably linked to macrophagic differentiation.
We have isolated clones containing the entire mouse proliferating cell nuclear antigen (PCNA) gene of 3890 bp and flanking sequences using a rat PCNA cDNA as a probe. The mouse gene has 6 exons whose sequences and junction points of exons with introns are extensively homologous to the human gene while sizes and nucleotide sequences of introns are much less conserved than exons. By a transient expression assay of chloramphenicol acetyltransferase, the promoter of this gene is localized within 200 bp upstream of the transcription initiation site. We have also isolated two processed pseudogenes. Homology between the first one (psi PCNA-I) and the exons of the PCNA gene was 76.8% in the region so far sequenced. The second one (psi PCNA-II) consists of a region highly homologous to the entire exons of the PCNA gene, and only 9 out of total 1256 bp are different from the corresponding exon sequence of the gene. The 5'-flanking region of the psi PCNA-II did not function as an active promoter. Surveys in various wild and laboratory mice genomes suggest that the psi PCNA-II was generated through the reverse transcription process of the PCNA mRNA about 5 x 10(5) years ago in the domesticus subspecies of Mus musculus, the house mouse. The psi PCNA-II is tentatively mapped in the chromosome 17 of the C57BL mouse.
To determine the effects of nocturnal hyperprolactinemia on luteal function and galactorrhea we studied six diurnal normoprolactinemic women with regular menstrual cycles. The diurnal serum levels of prolactin (PRL), luteinizing hormone (LH) and progesterone (Prog) and the nocturnal PRL levels at 1 h intervals were determined throughout the first menstrual cycle. Four of the women were nocturnally normoprolactinemic and two showed nocturnal hyperprolactinemia and low luteal progesterone values. In the second menstrual cycle, they were given metoclopramide (10 mg) at midnight before sleep every day, and their serum levels of PRL, LH and Prog were determined by the same protocol as in the first cycle. During treatment with metoclopramide, all the women showed nocturnal hyperprolactinemia, but their diurnal PRL levels remained within the normal range. Low luteal Prog values were observed in all of them and the peak LH levels decreased in all four nocturnally normoprolactinemic women. They had galactorrhea but neither of the nocturnally hyperprolactinemic women had galactorrhea. These results suggest that nocturnal hyperprolactinemia is a cause of luteal insufficiency and galactorrhea.
The mitochondrial energy-linked nicotinamide nucleotide transhydrogenase is a homodimer of monomer Mr = 109,228. Hydropathy analysis of its cDNA-deduced amino acid sequence (1043 residues) has indicated that the molecule is composed of 3 domains: a 430-residue-long hydrophilic N-terminal domain which binds NAD(H), a 200-residue-long hydrophilic C-terminal domain which binds NADP(H), and a 400-residue-long hydrophobic central domain which appears to be made up mainly of about 14 hydrophobic clusters of approximately 20 residues each. In this study, antibodies were raised to the hydrophilic N- and C-terminal domains cleaved from the isolated transhydrogenase by proteolytic digestion, and to a synthetic, hydrophilic pentadecapeptide, which corresponded to position 540-554 within the central hydrophobic domain. Immunochemical experiments with mitoplasts (mitochondria denuded of outer membrane) and submitochondrial particles (inside-out inner membrane vesicles) as sources of antigens showed that essentially the entire N- and C-terminal hydrophilic domains of the transhydrogenase, as well as epitopes from the central pentadecapeptide, protrude from the inner membrane into the mitochondrial matrix, where the N- and C-terminal domains would be expected to come together to form the enzyme's catalytic site. Treatment of mitoplasts with several proteolytic enzymes indicated that large protease-sensitive masses of the transhydrogenase are not exposed on the cytosolic side of the inner membrane, which agreed with the exception that the central highly hydrophobic domain of the molecule should be largely membrane-intercalated. Trypsin, alpha-chymotrypsin, and papain had little or no effect on the mitoplast-embedded transhydrogenase. Proteinase K, subtilisin (Nagarse), thermolysin, and pronase E each split the mitoplast-embedded enzyme into two fragments only, a fragment of approximately 70 kDa containing the N-terminal hydrophilic domain, and one of approximately 40 kDa bearing the C-terminal hydrophilic domain. The cleavage site of proteinase K was determined to be A690 -A691, which is located in a small hydrophilic segment within the central hydrophobic domain. This protease-sensitive loop appears to be exposed on the cytosolic side of the inner membrane. The proteinase K-nicked enzyme containing two peptides of 71 and 39 kDa was isolated from mitoplasts and shown to have high transhydrogenase activity.
Incubation of isolated rat liver nuclei with ATP, NAD+, and micromolar Ca2+ concentrations of various metal ions resulted in extensive DNA hydrolysis. Half-maximal activity occurred with 1.0 microM Ca2+ added, and saturation of the process was observed with 10 microM Ca2+. The Ca2+ (10 microM)-activated DNA fragmentation was inhibited by the presence of Ca2(+)-binding protein regucalcin isolated from rat liver cytosol. The inhibitory effect of regucalcin was complete at 0.5 microM. At 25 microM Ca2+ added, such an effect of regucalcin (1.0 microM) was not seen. Regucalcin also inhibited Ca2(+)-activated DNA fragmentation in the presence of calmodulin (10 and 20 micrograms). The results show that regucalcin can inhibit the Ca2(+)-activated DNA fragmentation due to binding the metal, suggesting a role in regulation of liver nuclear functions.
A 75-year-old female patient with agranulocytosis caused by ticlopidine is reported. She took the drug at 200 mg/day for 30 days to prevent recurrence of cerebral infarction. The leukocyte count at the nadir was 500/microliters on the 34th day since she started to take the drug. Complete recovery of her peripheral leukocytes came 12 days after its withdrawal. In this patient, mechanisms of ticlopidine-caused agranulocytosis were studied. The lymphocyte stimulation test using ticlopidine was negative. In the culture of marrow cells depleted of lymphocytes, ticlopidine directly inhibited the CFU-C in a dose-dependent manner. Neither the serum on the day of admission nor the T-lymphocytes pre-cultured with ticlopidine had any effect on the CFU-C. The lymphocyte stimulation test is useless in an attempt to find the causal drug in agranulocytosis if it is caused in a directly toxic manner. Agranulocytosis caused by ticlopidine is rare, but careful follow-up is necessary in the case of patients on the drug because there are some whose marrow cells are very sensitive to it.
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Lithium carbonate was given in the preoperative preparation of 12 patients with Graves' disease, the reasons for its use being side effects of thionamide in 9 patients, insufficient control by thionamide in 1 and psychic symptoms in 2. Lithium carbonate was often used in combination with other drugs, namely; thionamide in 4 patients, beta-adrenergic blockades in 5, reserpine in 5 and glucocorticoid in 1. This preoperative control significantly decreased the mean serum T2 and T4 levels from 656 +/- 55 ng/dl to 180 +/- 16 ng/dl and from 25.9 +/- 2.1 micrograms/dl to 9.7 +/- 1.5 micrograms/dl, respectively. The only adverse effect of lithium carbonate was pollakisuria observed in one patient. All patients underwent subtotal thyroidectomy uneventfully. It is concluded that the administration of lithium carbonate alone or in combination with other drugs is an effective method of preoperatively controlling hyperthyroidism when conventional antithyroid drugs show adverse effects.
The effect of simulated weightlessness on bone glucose consumption was investigated in skeletal unloading for up to 4 days. Skeletal unloading was designed using the model of hind-limb hang in rats. Femoral-diaphyseal fragments obtained from rats bred with skeletal unloading were cultured for 24 h at 37 degrees C in 5% CO2/95% air in Dulbecco's Modified Eagle Medium (high glucose, 4.5 g/dl). The consumption of medium glucose by bone tissues was significantly decreased by skeletal unloading for 2 and 4 days, while the production of lactic acid from bone tissues was not significantly altered. In addition, adenosine triphosphate (ATP) content in the cultured bone was significantly decreased by skeletal unloading. The presence of calcitonin (synthetic [Asu1,7] eel, 3 and 30 nM) fairly restored bone glucose consumption impaired by skeletal unloading. However, the effect of insulin (1 and 10 nM) on bone glucose consumption and ATP content was not seen in the bone tissues with skeletal unloading. These results suggest that the sensitivity of bone response for insulin action is reteriorated by skeletal unloading.