[Action of oxytetracycline on trachoma virus].
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Chlamydia↗
Biomedical subjects
M Matsubara
Publications and source records attributed to M Matsubara.
On the presence of sepiapterin reductase different from folate and dihydrofolate reductase in chicken liver.
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Animals↗
Flow cytometric analysis of the direct toxic effects of paraquat on cultured MDCK cells.
We used flow cytometry to assess the cell cycle kinetics of cultured Maden Darby canine kidney cells after exposure to paraquat. Fluorescein diacetate fluorescence was used as a marker of cell viability, while bromodeoxyuridine incorporation was detected with a monoclonal antibody and propidium iodide staining to assess DNA synthesis. Flow cytometry was performed immediately, 48 h and 96 h after exposure to paraquat for 24 h. Lactate dehydrogenase release was also measured to determine the extent of cytolysis. Flow cytometry of paraquat-treated cells showed a marked increase of the S phase population immediately after exposure, at a time when there was no increase of lactate dehydrogenase release. In contrast, the cell cycle profile returned towards normal at 48 and 96 h after paraquat exposure, but lactate dehydrogenase release increased. These findings indicate that paraquat arrested cells in the S phase and that inhibition of DNA synthesis by this agent appeared to influence cell viability because S phase block occurred before cytolysis. In addition, this method proved useful for assessing the effects of paraquat on DNA synthesis by cultured cells.
Animals↗
Homologous maturase-like proteins are encoded within the group I introns in different mitochondrial genes specifying Yarrowia lipolytica cytochrome c oxidase subunit 3 and Saccharomyces cerevisiae apocytochrome b.
A mitochondrial cox3 gene in the alkane yeast, Yarrowia lipolytica, encodes a subunit-3 protein of cytochrome c oxidase, and contains a 1044 base-pair-long intron, as compared with the corresponding intronless gene in Saccharomyces cerevisiae. The intron belongs to a group I intron as determined by the cDNA sequence for the splicing sites as well as the predicted RNA secondary structure. Remarkably, this intron could code for a protein of 206 amino-acid residues which showed 63% similarity with an RNA maturase encoded by the second intron of the mitochondrial apocytochrome b gene in S. cerevisiae. Both introns occurred within the conserved exon sequence, 5'-TT(G/C)AGGTGC-3', suggesting the possible transposition of a common ancestral intron.
Amino Acid Sequence↗
Organization and transcription of the mitochondrial ATP synthase genes in the yeast Yarrowia lipolytica.
Mitochondrial gene organization was studied in a dimorphic yeast, Yarrowia lipoltica. The gene order in a sequenced 6.6-kilobase region closely resembles that of the human mitochondrial genome in that ATP synthase subunit 8 and 6 genes are followed by genes for cytochrome c oxidase subunit 3 (which contains an intron), NADH-ubiquinone oxidoreductase subunit 4, and ATP synthase subunit 9. This region also contains tRNA genes decoding AUA, UGA, CUN and CCN codons, suggesting a unique mitochondrial translation. All the above genes are transcribed from the same DNA strand into multigenic RNAs, starting from a nonanucleotide sequence, 5'-ATATAAATA-3', similar to other yeast mitochondrial promoters.
Amino Acid Sequence↗
A new system to supply carbon dioxide safely to glaucoma patients.
PURPOSE: To develop a new system for safely supplying carbon dioxide (CO2) to open-angle glaucoma patients. METHODS: The orbital hemodynamics of 7 glaucoma patients were determined by color Doppler imaging under baseline conditions and during CO2 supplementation sufficient to increase the end-tidal CO2 partial pressure by 10%. Systemic conditions, including oxygen saturation and blood pressure, were monitored throughout the CO2 inhalation. RESULTS: Our results demonstrate that this new system enables us to supply CO2 in a safe, controlled manner to glaucoma patients. CONCLUSIONS: This new system will be useful for investigating the effects of vasodilation by CO2 on orbital blood flow.
Administration, Inhalation↗
Valproic acid overdose and L-carnitine therapy.
A healthy, nonepileptic 16-month-old child ingested a massive overdose (approximately 4000 mg) of valproic acid (VPA). Upon admission to the hospital, he was in a deep coma and had generalized hypotonicity and no response to pain. His serum and urinary concentrations of VPA were 1316.2 and 3289.5 micrograms/mL, respectively. Urinary concentrations of the beta-oxidation metabolites of VPA were low, whereas concentrations of omega- and omega 1-oxidation metabolites were high. Moreover, 4-en-valproate (a potential hepatotoxin) was detected in the urine. Gastric lavage and general supportive measures were undertaken, including intravenous infusion to increase urine output and oral L-carnitine to correct hypocarnitinemia. Subsequently, the beta-oxidation metabolites increased, the omega- and omega 1-oxidation metabolites decreased, and 4-en-valproate was no longer detected. The patient recovered completely and was discharged on the eighth hospital day without any sequelae. This case suggests that enhanced drug excretion and L-carnitine supplementation may prevent potentially fatal hepatic dysfunction after VPA overdose.
Anticonvulsants↗
A study of derivative spectrophotometry for the determination of carboxyhemoglobin in blood.
An application of derivative spectrophotometry to the determination of carboxyhemoglobin (HbCO) in blood was examined. The 1st, 2nd, 3rd, and 4th derivative spectra were recorded in the Soret region for HbCO, reduced hemoglobin (Hb), and their mixed solution. The 4th derivative spectrum had the highest sensitivity to the change of HbCO-Hb ratio in the solution. A maximum point of the 4th derivative curve was employed for the HbCO determination. Blood samples with varied HbCO concentrations were analyzed using this technique and the results were compared with those obtained by conventional spectrophotometric and gas chromatographic procedures. The derivative method was in satisfactory agreement with both procedures.
Carboxyhemoglobin↗
Determination of carboxyhemoglobin in heated blood--sources of error and utility of derivative spectrophotometry.
The cause for discrepancies in results from different methods of the carboxyhemoglobin (HbCO) analysis on the blood from bodies of burn victims was investigated. Blood samples with 0, 50, and 100% carbon monoxide (CO) saturation were heated at various temperatures for some time and then analyzed. Carboxyhemoglobin content was determined by the fourth-derivative spectrophotometric method and compared with results from the usual two-wavelength method. For total hemoglobin measurement, the fourth-derivative technique and cyanmethemoglobin method were used. Turbidity in blood samples, which occurred when samples were heated above 50 degrees C, affected the analysis. At about 70 degrees C, coagulation and hemoglobin degeneration occurred accelerating the errors of determined values. The fourth-derivative technique, however, proved to be independent of the turbidity and would be useful for the analysis on the blood without hemoglobin degeneration.
Carboxyhemoglobin↗
Genetic association between Alzheimer disease and the alpha-synuclein gene.
alpha-Synuclein has been isolated as a component of amyloid in addition to the major A beta peptide in Alzheimer disease (AD). However, there are conflicting reports regarding the association of alpha-synuclein gene polymorphism with AD. Using a novel and common polymorphism in intron 3, we examined the relationship between AD and alpha-synuclein and apolipoprotein E (ApoE) genes in 183 Japanese AD patients and 210 controls. Carriers of the alpha-synuclein deletion (D) allele had a 2.2-fold increased risk of developing AD than noncarriers in women. The odds ratio for the ApoE epsilon 4 and the alpha-synuclein D allele was 11.4 in women. The results showed that the alpha-synuclein gene is associated with sporadic AD in women, independent of ApoE epsilon 4 status.
Aged↗
Topographic distribution of aquaporin 2 mRNA in the kidney of dehydrated rats.
BACKGROUND: Stimulation of arginine vasopressin results in an immediate redistribution of water channels (aquaporin 2; AQP2) in the apical membrane of the collecting ducts, leading to water reabsorption. Water restriction for >/=24 h increases AQP2 proteins in the whole collecting duct which is highest in the inner medulla of the kidney, indicating that dehydration enhances synthesis of this protein. Although increased expression of AQP2 mRNA under this condition has been reported, the increased ratio of mRNA expression in the three regions of the kidney, cortex, outer medulla, and inner medulla, during the dehydration is still unclear. METHODS: We investigated the AQP2 transcripts using male Sprague-Dawley rats deprived of water for 24 h. Mimic cDNA for competitive polymerase chain reaction (PCR) was constructed by deleting 180 bp at the middle of a 780-bp partial PCR product for rat AQP2 cDNA. In situ hybridization of the kidney and Northern blotting of inner medulla were performed using a 60-bp oligo-cDNA probe which identified rat AQP2 transcripts in the collecting duct. RESULTS: Dehydration resulted in a significant increase in plasma osmolality and arginine vasopressin concentration and urinary osmolality. Competitive PCR demonstrated that dehydration increased AQP2 transcripts in all parts of the kidney, but was highest in the inner medulla. Northern blotting confirmed the high increased rate of AQP2 transcription in the inner medulla. In situ hybridization showed markedly intensified signals in the inner medulla of dehydrated rats. CONCLUSIONS: Our data indicate that dehydration increases the abundance of AQP2 transcripts which may be closely associated with enhancement in AQP2 protein synthesis reported previously. This topographically variable increase in transcription is considered to be one of the mechanisms involved in long-term regulation of water permeability in the collecting duct.
Animals↗
Long-term CaCO3 treatment of chronic hemodialysis patients: an attempt to prevent aluminum osteopathy.
Long-term CaCO3 treatment of chronic hemodialysis patients was studied. Single doses of CaCO3 were given to 25 patients, 23 of whom had been receiving Al(OH)3 before the study. When predialysis serum calcium (Ca) rose to greater than 5.5 mEq/L, CaCO3 was reduced and Al(OH)3 was administered again. Eighteen months later, serum phosphate (P) was well controlled, and predialysis serum P was less than 6.5 mg/dl in 14 patients given CaCO3 alone. Alkaline phosphatase (ALP) levels significantly decreased, and serum aluminum was remarkably lowered in patients who had discontinued Al(OH)3. In patients who resumed Al(OH)3, ALP levels rose after Al(OH)3 administration. Although levels of c-PTH did not change in CaCO3 treated patients, six patients with poor control of serum P before the study showed a significant decrease in c-PTH. These data indicate that CaCO3 is an effective P binder that stops the progression of silent osteopathy, presumably caused by oral intake of Al(OH)3, and may ameliorate these changes. However, further effort will be necessary to develop means to control serum Ca, because long-term use of CaCO3 induced hypercalcemia in half the patients.
Adult↗
Effects of danazol on proliferation and viability of 7,12-dimethylbenz(a)anthracene-induced mammary tumours in rats.
The suppressive effects of danazol, an isoxazol derivative of a synthetic steroid 17 alpha-ethinyltestosterone, on cellular viability and DNA synthesis in 7,12-dimethylbenz(a)anthracene induced mammary tumours were investigated in adult female rats by enzyme assays and immunohistochemistry with bromodeoxyuridine (BrdU). Rats treated with danazol for 30 days showed a decrease of plasma levels of luteinizing hormone and estradiol associated with a dysfunction in hypothalamo-hypophysial-gonadal axis, resulting in lower activities in succinate dehydrogenase and thymidine kinase, and a reduction of BrdU-immunoreactive cells in mammary tumours compared with the control, i.e., decreases of viability and pyrimidine nucleotide synthesis in tumour cells in danazol-treated rats.
9,10-Dimethyl-1,2-benzanthracene↗
Effects of 5-fluorouracil derivatives on papillomas induced by application of 7,12-dimethylbenz(a)anthracene in mice.
We examined the effects of an application of 5-fluorouracil (5-FU) ointment and a chronic oral administration of 1-(2-tetrahydrofuryl)-5-FU plus uracil (UFT) on 7,12-dimethyl-benz(a)-anthracene-induced squamous cell papillomas in mice. Although application of 5-FU ointment reduced the growth of papillomas slightly, chronic oral administration of UFT could prevent tumorigenesis and suppress the growth of papillomas, resulting in the reduction of the tumorous viability and DNA synthesis.
9,10-Dimethyl-1,2-benzanthracene↗
Effects of bifemelane hydrochloride on cerebral circulation and metabolism in patients with aphasia.
The effects of bifemelane hydrochloride on aphasia and on cerebral circulation and metabolism were studied using positron emission tomography (PET) in 10 aphasic patients with cerebrovascular disease. After the first PET scan, bifemelane was administered orally three times in a daily dose of 150 mg. Aphasic features, such as fluency, auditory comprehension, object naming, and repetition, were evaluated by using the Western Aphasia Battery (Japanese edition) before and at least 2 months after bifemelane treatment. Simultaneous with the evaluation of aphasia, the PET scans were performed by using the steady-state method with 15O gases inhalation. All aphasic features, except fluency, improved significantly after bifemelane treatment. Regional cerebral blood flow (rCBF) and the cerebral metabolic rate for oxygen (CMRO2) were increased at every brain region of interest, and the oxygen extraction fraction was decreased. Both rCBF and CMRO2 were significantly increased on the left inferior frontal gyrus, superior temporal gyrus, white matter of the parietal lobe, and insula. These results suggest that bifemelane improves both cerebral oxygen metabolism and cerebral circulation and contributes to the improvement of aphasia caused by cerebrovascular disease.
Adult↗