[A case of psittacosis complicated with adult respiratory distress syndrome and thrombotic thrombocytopenic purpura ].
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Coxsackievirus Infections↗
Biomedical subjects
T Hidaka
Publications and source records attributed to T Hidaka.
Effects of diethyl maleate (DEM), a glutathione depletor, on prostaglandin synthesis in the isolated perfused spleen of rabbits.
To investigate the role of glutathione (GSH) on prostaglandin (PG) synthesis, isolated rabbit spleens were perfused with Tyrode's solution with or without the addition of diethyl maleate (DEM) in concentrations up to 1 mM. In the absence of DEM, PG synthesis was stimulated by the Ca2+ ionophore A23187 (20 nmole) or arachidonate (0.4 mumole). Prostaglandin (PG) E2 was a major product, accounting for 60-70% of the total cyclooxygenase products. Small amounts of PGF2 alpha, 6-keto-PGF1 alpha, PGD2 and thromboxane (Tx) B2 were also produced. When DEM was added to the perfusion medium, GSH content decreased dose-dependently with increasing DEM concentration. Lactate dehydrogenase activity was not detected in the venous effluent, indicating that DEM depleted intrasplenic GSH without causing any lysis of cellular membranes. A23187-induced production of PGs and of Tx was decreased with increasing concentrations of DEM up to 0.5 mM, whereas at 1.0 mM DEM, these products showed a tendency to increase as compared with levels at 0.5 mM DEM. However, this increase was only significant for TxB2, which returned to levels obtained in the absence of DEM. DEM 1 mM did not cause cell lysis, but it appears to perturb the cell membrane to a degree similar to that which occurs with stimulation of phospholipase A2. The small but significant increase of TxB2 with 1.0 mM DEM could be a result of decreased PGE2 isomerase activity. Perfusion with arachidonate gave virtually identical results: 1.0 mM DEM attenuated the production of all prostanoids except for TxB2 as compared with untreated controls. These results suggest that GSH contributes to the regulation and/or maintenance of PGs synthesis.
Animals↗
Electrical myotonia and cataract in X-linked muscular dystrophy (mdx) mouse.
An X chromosome-linked mouse mutant (mdx) has been investigated as an animal model of Duchenne's muscular dystrophy, and has been found to have the same defect of dystrophin in the muscle surface membrane. Intracellular recordings from the mdx mouse hemidiaphragm preparations revealed low resting membrane potentials and electrical myotonia which occurred at the time of microelectrode insertion and withdrawal. Electrical myotonia of the mdx mouse was observed in 30-50% of the impaled muscle fibers at low temperature, which decreased to only 7.8% at 37 degrees C. Electrical myotonia of mdx mice was not abolished by (+)-tubocurarine. Though there was no behavioral myotonia in mdx mice, repetitive bursts of action potentials in mdx mice were based on the abnormalities of the muscle membrane since neuromuscular blockade did not abolish the repetitive bursts. Also close observation of the lenses of mdx mice revealed cataracts from the newborn stage to the adult age. Slit lamp examination of the lenses of the mdx mice revealed nuclear cataracts followed by anterior subcapsular cataract as they grew. The cataract of mdx mice is different from that of myotonic dystrophy which is usually posterior subcapsular.
Animals↗
Distribution of superoxide dismutase activity in the epidermis: measurement with electron spin resonance spin trapping.
Superoxide dismutase (SOD) activity in cow snout epidermis was determined by the method of electron spin resonance (ESR) using the 5, 5 dimethyl-1-pyrroline-N-oxide (DMPO) spin trapping agent. The procedure was found to be a reliable measurement as compared with the ordinary method using xanthine oxidase NBT. SOD activity was distributed through the whole epidermis. This activity was higher in the lower layer than in the upper and middle layers.
Animals↗
The stabilizing effect of bestatin on the resting membrane potentials of X-linked muscular dystrophy mice.
The resting membrane potentials of X-linked muscular dystrophy (mdx) mice are about 10 mV lower than those of control (C57BL/10Sc) mice. Also repetitive action potentials which resemble insertion myotonia are frequently recorded intracellularly from the mdx mice of various ages. When the mdx mice are treated with bestatin intraperitoneally for 7 days, the RMP's improvement almost attained its normal levels. Repetitive action potential bursts (electrical myotonia) recorded at the time of microelectrode insertion had decreased or abolished after bestatin therapy. Another set of in vitro experiments to see direct action of bestatin to the hemidiaphragm preparations of the mdx mice reveal improvement in RMP's and a reduction in electrical myotonia within a 30-minute exposure to Tyrode's solution with bestatin. Bestatin has a favorable direct effect on the muscle fiber membrane to stabilize RMP's and suppress muscle membrane irritability.
Animals↗
Carboxyphosphonoenolpyruvate phosphonomutase, a novel enzyme catalyzing C-P bond formation.
An enzyme catalyzing the formation of an unusual C-P bond that is involved in the biosynthesis of the antibiotic bialaphos (BA) was isolated from the cell extract of a mutant (NP71) of Streptomyces hygroscopicus SF1293. This enzyme, carboxyphosphonoenolpyruvate (CPEP) phosphonomutase, was first identified as a protein lacking in a mutant (NP213) defective in one of the steps in the pathway to BA. The first 30 residues of the amino terminus of this protein were identical to those predicted by the nucleotide sequence of the gene that restored BA production to NP213. The substrate of the enzyme, a P-carboxylated derivative of phosphoenolpyruvate named CPEP, was also isolated from the broth filtrate of NP213 as a new biosynthetic intermediate of BA. CPEP phosphonomutase catalyzes the rearrangement of the carboxyphosphono group of CPEP to form the C-P bond of phosphinopyruvate.
Anti-Bacterial Agents↗
Percutaneous treatments for biliary diseases.
Percutaneous treatment of biliary disease was administered in 173 cases, mainly among high-risk or elderly patients. Diagnosis was acute cholecystitis in 32 cases, acute cholangitis in 16, hepatic abscess in five, gallbladder stones in 28, common bile duct stones in 11, intrahepatic stones in five, malignant obstructive jaundice in 61, and benign biliary stenosis in 15. The treatment was successful in 158 of 173 cases (91.3%). Complications were encountered in 17 (9.8%). Most of these occurred during the initial period and were mild and controllable with conservative treatments. There were two deaths (1.2% of patients); one was not related to the procedure. These data suggest that percutaneous treatments are safe and effective even among elderly or high-risk patients with biliary diseases.
Adult↗
Altered hepatic metabolism of free fatty acid in rats fed a threonine-imbalanced diet.
The effects of a threonine-imbalanced diet (8% casein supplemented with 0.3% methionine, TI) on the ketone body production and the secretion rate of lipids were examined in the isolated perfused rat liver. Feeding a TI diet compared to an 8% casein (C) diet resulted in an enlargement of liver, presumably due to 2-4-fold accumulation of triglyceride. Serum triglyceride likewise increased significantly in rats fed a TI diet. No significant difference was found in the other lipid components both in serum and liver. When the livers from rats fed C or TI diets were isolated and perfused in the presence of an exogenous oleate substrate, the TI diet decreased the ketone body production and conversely increased the secretion rate of triglyceride, suggesting an inverse relationship between rates of ketogenesis and triglyceride secretion. The proportion of oleate in the perfusate triglyceride obtained at the end of perfusion was comparable between the C and TI groups, whereas in the post-perfused liver it was higher in the former than in the latter, suggesting a stimulatory effect of the TI diet on the secretion of the oleate in the form of triglyceride. These results indicate that altered hepatic metabolism of long-chain free fatty acids between the pathways of oxidation and esterification is one of the causative factors for triglyceride accumulation in the liver produced by threonine imbalance.
Animals↗
Isolation and structures of mono- and di-deacetyl chromomycin antibiotics 02-3D and 02-3G from Streptomyces avellaneus.
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Chromatography, High Pressure Liquid↗
Biochemical mechanisms of C-P bond formation of bialaphos: use of gene manipulation for the analysis of the C-P bond formation step.
One of the three C-P bond formation steps, defined as step 5 in the bialaphos (BA) biosynthetic pathway, was analyzed using a new BA non-producing mutant NP71. The mutant was derived from a BA producer by gene replacement of an unidentified region next to the gene responsible for the step 5 deficiency of the mutant NP213, obtained by conventional mutation procedures. Biochemical analysis of these two mutants indicated that NP71 was defective in the formation of carboxyphosphonoenolpyruvate (CPEP), while NP213 lacked the enzyme CPEP phosphonomutase, which catalyzed the intramolecular rearrangement of CPEP.
DNA↗
[A case of systemic lupus erythematosus complicated with multifocal posterior pigment epitheliopathy].
Multifocal posterior pigment epitheliopathy (MPPE) is a rare complication of systemic lupus erythematosus (SLE) and resistant to treatment. We here report a case of SLE with MPPE, successfully treated with prednisolone (PSL) and laser photocoagulation therapy. A 38-year-old woman, who had suffered from SLE for four years, was admitted to our hospital with the complaints of left hemiparesis, right homonymous hemianopsia, and dysarthria. The findings of MRI suggested her symptoms were caused by cerebrovascular involvement of SLE. The treatment with prednisolone was started at a dose of 100 mg per day. While the dose of PSL was reduced, she began to complain of paresthesia in left face and myodesopsia of left eye. Based upon the result of fluorescein angiogram, the diagnosis of MPPE was made. Since MPPE accompanied exacerbation of neurological manifestation, we considered that MPPE was a symptom of vascular involvement of SLE. MPPE was treated with laser photocoagulation therapy and an increased dosage of PSL, with favorable results. It has not been reported, as far as we concern, that laser photocoagulation therapy is effective for MPPE caused by SLE. This case is important for the pathogenesis and therapy of MPPE with SLE.
Adult↗
Influence of vitamin B2 on formation of chromium(V), alkali-labile sites, and lethality of sodium chromate(VI) in Chinese hamster V-79 cells.
The effect of vitamin B2 on the cellular reduction and cytotoxicity of chromate(VI) was studied using Chinese hamster V-79 cells. Electron spin resonance studies showed that incubation of cells with Na2CrO4 resulted in the formation of both chromium(V) and chromium(III) complex and that cellular pretreatment with riboflavin (Vitamin B2) for 24 h prior to exposure increased the level of chromium(V) complex, but the level of chromium(III) remained unchanged. Analysis of flavin derivatives revealed that pretreatment with vitamin B2 increased free riboflavin without altering flavin adenine dinucleotide and flavin mononucleotide. In addition, the level of the flavoenzyme glutathione reductase, which is capable of reducing chromate, was unaffected by pretreatment with vitamin B2. However, treatment of cells with vitamin B2 and Na2CrO4 augmented the inhibition of glutathione reductase attributable to Na2CrO4 alone. Using a colony-forming assay, pretreatment with vitamin B2 resulted in a decrease of cytotoxicity after exposure to the lethal concentration of chromate (15 microM) but did not affect the cytotoxicity at sublethal concentration of this metal (5-7.5 microM). Alkaline elution studies demonstrated that Na2CrO4 induced alkali-labile sites in the DNA of cells in a concentration-dependent manner (5-15 microM) and pretreatment with vitamin B2 resulted in an increase of these DNA lesions at all concentrations of Na2CrO4. The results, showing that vitamin B2 enhances chromate-induced alkali-labile lesions and chromium inhibition of glutathione reductase, might be due to an increase of chromium(V) species, possibly through its ability to directly reduce chromium(VI). The results also suggest that the extent of DNA lesions induced by chromate may not correlate directly with the cytotoxic effects of this metal.
Animals↗
Membrane responses of B-16 melanoma cells to single exposure to ultraviolet light.
Electron spin resonance spectroscopy using the spin probe (5-, 12- and 16-deoxylstearic acid) was employed to analyze the changes in membrane fluidity in B-16 melanoma cells following UV-B exposure. The UV exposure resulted in the immediate accumulation of lipid peroxide, being accompanied by a change in membrane fluidity. The 12-DSA is the most sensitive to the changes in membrane organization caused by UV light. Na+,K+-ATPase activity was regulated by a change in membrane fluidity. Following UV exposure, the release of the prelabeled arachidonic acid from the cells was observed immediately. Ca2+-dependent calmodulin-dependent phospholipase A2-like activity was involved in the UV-stimulated arachidonic acid release from phospholipid.
Arachidonic Acid↗
Stimulation of prostaglandin synthesis by cholecystokinin in primary culture cells of bovine gallbladder muscle.
Primary culture cells derived from bovine gallbladder muscles synthesize PGE2 as a major cyclooxygenase product with a trace amount of 6-keto-PGF1 alpha-like material. The synthesis of PGE2 and total cyclooxygenase products was enhanced in response to cholecystokinin (CCK). In the presence of indomethacin the synthesis of PG was inhibited and the release of arachidonic acid (AA) in response to CCK was enhanced. These data suggest that CCK may stimulate the release of AA, probably by activating phospholipase A2/C, from membrane phospholipids in the gallbladder muscle.
Animals↗
Effect of UV-B irradiation on release of arachidonic acid from B-16 melanoma cells.
B-16 melanoma cells in culture were prelabeled with (3H)-arachidonate, and exposed to UV radiation. Immediately after irradiation the cells released labeled materials. This UV-stimulated release was inhibited by mepacrine (20 microM) and calmodulin inhibitor W7 (0.5 microM). To determine the influence of extracellular Ca2+ on the UV-stimulated release, experiments were made with media containing various concentrations of Ca2+. The release decreased significantly at lower Ca2+ concentrations. These results suggest that Ca2+-calmodulin-dependent phospholipase A2 was involved in UV-stimulated release of radiolabeled materials, possibly arachidonic acid and its metabolites, from the cells.
Arachidonic Acids↗
Dihydropyrimidines: novel calcium antagonists with potent and long-lasting vasodilative and antihypertensive activity.
The novel calcium antagonists 3-N-substituted-3,4-dihydropyrimidines 1 and 9 and 3-N-substituted-dihydro-pyrimidin-2(1H)-ones 8 were regioselectively synthesized in good yields. Compounds 1 [especially 1s [R1 = (CH2)2N(benzyl)(2-naphthylmethyl), R2 = i-Pr, X = 0-NO2] and 1t [R1 = (CH2)2N(benzyl)(3,4-dichlorobenzyl), R2 = i-Pr, X = 0-NO2]] exhibited not only more potent and longer lasting vasodilative action but also a hypotensive activity with slow onset as compared with dihydropyridines. Moreover, some dihydropyrimidines [1q [R1 = (CH2)2N(benzyl)(3-phenylpropyl), R2 = CH2(cyclopropyl), X = 0-NO2], 1s, and 1t] were weaker in blocking atrioventricular conduction in anesthetized open-chest dogs and less toxic than the dihydropyridines.
Animals↗
Changes of electron spin resonance membrane fluidity in hexadecane-induced hyperproliferative epidermis.
To study some of the biochemical and physical states of membranes associated with hyperproliferation, the effect of topical hexadecane on membrane fluidity in guinea pig epidermis was investigated by electron spin resonance using a 5-doxylstearic acid spin labeling agent. Guinea pig epidermal cells were separated into three regions of keratinocytes by Percoll density gradient centrifugation. Membrane fluidity and Na+, K+-ATPase activity were higher in hyperproliferating epidermal cells than in control. The free cholesterol content and the molar ratio of free cholesterol to phospholipid were found to decrease significantly. Also elevated levels of palmitic acid, stearic acid and omega-3 unsaturated fatty acid derived from phospholipid were observed. Normal differentiation of epidermis was found to be accompanied by a decrease in membrane fluidity, whereas a relatively high membrane fluidity was maintained in the hexadecane-induced hyperproliferation.
Alkanes↗
Studies on the biosynthesis of bialaphos (SF-1293). 9. Biochemical mechanism of C-P bond formation in bialaphos: discovery of phosphoenolpyruvate phosphomutase which catalyzes the formation of phosphonopyruvate from phosphoenolpyruvate.
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Anti-Bacterial Agents↗