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Biomedical subjects

I Matsuda

Publications and source records attributed to I Matsuda.

At least 343 records · Page 19Linked to original sources

Four methods compared for measuring des-carboxy-prothrombin (PIVKA-II).

PIVKA-II (Protein Induced by Vitamin K Absence) is abnormal des-carboxylated prothrombin, which is present in vitamin K deficiency or in patients using warfarin. With a sensitive method for PIVKA-II, biochemical vitamin K deficiency can be established before clinical symptoms occur. We give an overview of methods used to detect PIVKA-II, and four selected methods are inter-compared: (a) measuring total factor II including PIVKA-II by using Echis carinatus snake venom as an activator of prothrombin; (b) measuring PIVKA-II by using snake venom as an activator of factor II after adsorption of functional factor II onto barium sulfate; (c) electrophoresis-immunofixation method; and (d) enzyme immunoassay. We found d to be the most sensitive and reliable method for PIVKA-II.

Adsorption↗

[Primary amelanotic malignant melanoma of the vagina--a case report].

A case of a primary amelanotic melanoma of the vagina is reported. The patient was a 58-year-old Japanese female. A polypoid tumor was found on the lateral wall of the vagina and a cytologic examination of a scraping showed a few large atypical cells with cleaved nuclei and intranuclear vacuoles. A lateral junctional spread was histologically observed and stage II melanosomes were found in the cytoplasm. Two years after a radical operation, the patient died of a widespread melanotic metastases. The authors survey the number of incidences of malignant melanoma in the female genital organ. In Japanese women, melanoma is seen more frequently in the vagina than in the vulva, which is quite the opposite in cases of malignant melanomas of the genital organs in women of the United States and Europe.

Female↗

Amplification of human argininosuccinate synthetase pseudogenes.

The human genome contains multiple pseudogenes for an argininosuccinate synthetase (AS) gene. To elucidate the molecular mechanisms of generation and dispersion, complete nucleotide sequences of four different AS pseudogenes, psi AS-Y, psi AS-A1, psi AS-A2 and psi AS-A3, have been determined. A comparison of these sequences with those of three reported AS pseudogenes, psi AS-1, psi AS-3 and psi AS-7 revealed that two pairs, psi AS-Y/psi AS-7 and psi AS-A3/psi AS-1, are highly homologous but not identical, thereby suggesting that one of the pairs is generated by a duplication of the other member of the pairs. The psi AS-Y, which is probably located on chromosome Y, and the partially sequenced psi AS-7 are both interrupted by an Alu element at exactly the same site in their 3'-end regions. These two Alu elements are located in an opposite orientation relative to the direction of transcription of the pseudogene, and their possible role on pseudogene dispersion was examined. The psi AS-A1 is also accompanied by an Alu element at its 3' end. In this case, the orientation of the Alu element is the same as that of the pseudogene. The psi AS-A1 and the Alu element are flanked with direct repeats, as if they had been inserted into a chromosomal site, as a single unit.

Argininosuccinate Synthase↗

Decreased bone density in severely handicapped children and adults, with reference to the influence of limited mobility and anticonvulsant medication.

Bone density and related biochemical parameters were investigated in institutionalised children and adults with severe handicaps, who were classified according to the degree of limited mobility (group 1, bed-ridden; group 2, capable of crawling; group 3, capable of walking) and according to whether or not they were receiving anticonvulsants. As determined by microdensitometric analysis of radiograms of the second metacarpal bone, bone width (D), bone pattern area (sigma GS) and bone salt density (sigma GS/D) were decreased in the patients, the decreases being most prominent in group 1, followed by groups 2 and 3, in that order. Significant decreases of sigma GS and sigma GS/D, but not of D, were found in patients on anticonvulsant treatment in comparison to patients without therapy. Serum alkaline phosphatase (Al-p) and parathyroid hormone (iPTH) as well as urinary calcium and cyclic adenosine-3',5'-monophosphate (cAMP) excretion were significantly increased in group 1. In comparison to patients without therapy, anticonvulsant-treated children showed significantly decreased levels of serum calcium (Ca), ionised Ca (Ca2+), 25-hydroxy vitamin D3 and urinary phosphate (PO4) excretion, and elevated levels of Al-p, iPTH and calcitonin (iCT). It is suggested that limited physical activity results in a mild hyperparathyroid state, which is aggravated in patients on anticonvulsant treatment.

Adolescent↗

Pathology of skeletal muscle and intramuscular nerves in infantile neuroaxonal dystrophy.

Biopsies of the biceps muscle and sural nerve were taken from a girl aged 2 years with infantile neuroaxonal dystrophy (INAD). In addition to the typical axonal spheroid bodies in a number of the i.m. nerve fibers, the neuromuscular junctions (NMJs) and motor nerve endings also contained axonal swellings. The sural nerve, except for three dystrophic fibers, was almost completely normal. A teased nerve preparation showed four additional abnormal fibers with focal axonal enlargement similar to those in giant axonal neuropathy (GAN). These results suggest that a biceps muscle biopsy may be more useful than a sural nerve biopsy for the diagnosis of INAD, because the muscle contains abnormal peripheral nerves and NMJs in high frequency.

Axons↗

Cholecystokinin antagonism by benzodiazepines in the food intake in mice.

Three benzodiazepines, chlordiazepoxide, diazepam and flurazepam, were demonstrated to reverse the suppressed food intake in mice in response to cholecystokinin octapeptide (CCK8). CCK8 (200 ng) was administered intracisternally, and the benzodiazepines intraperitoneally at doses of 0.1 to 1 mg/kg. The three benzodiazepines slightly depressed the feeding by themselves, but significantly reversed the satiety effects of CCK8. Naloxone (2 mg/kg) decreased the food intake but failed to reverse the CCK8 satiety action. The benzodiazepines were considered to antagonize the satiety action of CCK8 in the central nervous system through unknown mechanisms.

Animals↗

Renal handling of carnitine in children with carnitine deficiency and hyperammonemia associated with valproate therapy.

Free and acylcarnitine in serum and urine samples were measured in five patients with hyperammonemia associated with anticonvulsant therapy including sodium valproate, of whom three had a Reye-like syndrome. All had considerable reduction in serum free carnitine and slight increase of acylcarnitine concentrations, suggesting increased conversion of free to acylcarnitine by valproate administration. Urinary excretion of both free and acylcarnitine was increased, accompanied by depressed reabsorption of free carnitine and decreased acylcarnitine/free carnitine clearance ratio. These results indicate a decreased threshold for free carnitine. The combination of these several factors may be responsible for carnitine deficiency in patients with hyperammonemia taking valproate.

Ammonia↗

Mitochondrial cytopathy with lactic acidosis, carnitine deficiency and DeToni-Fanconi-Debré syndrome.

We reported a 6-year-old girl with mitochondrial cytopathy with lactic acidosis. The patient developed hypotonia, hearing loss, mental retardation, short stature, cataracta, hypoparathyroidism, DeToni-Fanconi-Debré syndrome and carnitine deficiency. Histological examination disclosed ragged red fibers and moderate lipid storage in skeletal muscle tissue and several structural abnormalities of mitochondria both in muscle tissue and proximal renal tubules. Biochemical examination of muscle tissue revealed a partial deficiency of pyruvate dehydrogenase complex and normal activities of cytochrome c oxidase, succinate cytochrome c reductase and NADH cytochrome c reductase. This is the first report of mitochondrial cytopathy representing DeToni-Fanconi-Debré syndrome associated with partial deficiency of pyruvate dehydrogenase complex and normal cytochrome c oxidase activity.

Acidosis, Lactic↗

Unusual case of diffuse connective tissue disease with nodule formations in muscle, lung, kidney and brain.

A 9-year-old boy had nodular masses in the left gastrocnemius muscle and lung, right kidney and right frontal area of the brain. Laboratory examinations, including positive anti-nuclear antibody, anti-RNP antibody, RA and CRP, hyper-gamma-globulinemia and accelerated ESR, showed characteristic of diffuse connective tissue disease (DCTD). Biopsy specimens were obtained from the thymus and from masses in the left lung and gastrocnemius muscle. The thymus showed hyperplasia, and a mass in the lung showed nonspecific inflammatory reactions such as connective tissue proliferation and cellular infiltration. Biopsied muscle also showed severe connective tissue proliferation, cellular infiltration, variation in fiber size and thickened blood vessel walls. In addition, abnormalities, including thickening of the basement membrane and an almost occluded narrow lumen of capillaries, were found on electron microscopy examination. Steroid administration led to remarkable improvement of the symptoms. These results suggested that DCTD is responsible for these symptoms.

Biopsy↗

Isolation and characterization of the human ornithine transcarbamylase gene: structure of the 5'-end region.

We isolated over 20 phage clones carrying the ornithine transcarbamylase (OTC) [EC 2.1.3.3] gene, from two independently constructed human genomic DNA libraries, using as probes either a rat OTC cDNA or several nuclear DNA fragments derived from some of these isolated clones. These clones, classified into 10 different groups, overlapped and spanned a region of more than 85 kilobase pairs of the human genomic DNA. Restriction mapping and Southern blot analyses demonstrated that one of the clones covers the 5'-end region of the OTC gene. We sequenced the 5'-end region of the OTC gene and found that it covered 665 base pairs of the 5'-flanking region, the complete first exon and a part of the first intron (150 base pairs). In the 5'-flanking region, there were two pairs of putative CAAT and TATA boxes and one enhancer core-like sequence, GTGGAAAG. The first exon contained a coding region for most of the OTC presequence, i.e. 26 out of 32 amino acid residues of the presequence, including the initiation methionine.

Base Sequence↗

A new platelet antigen system, Yuka/Yukb.

We report a new platelet antigen (Yukb) involved in a case of neonatal alloimmune thrombocytopenia (NAITP). This antigen is considered to be a product of an allele of the Yuk gene, another allele of which codes for Yuka which was involved in 2 cases of NAITP. The Yuka and Yukb antigens are not expressed on thrombasthenic platelets which suggests that these antigens are present on platelet glycoprotein IIb and/or IIIa. The gene frequencies for Yuka and Yukb in the Japanese population were estimated to be 0.0083 and 0.9917, respectively.

Alleles↗

Yuka, a new platelet antigen involved in two cases of neonatal alloimmune thrombocytopenia.

We report a new platelet antigen (Yuka) defined by the sera of 2 mothers whose babies developed alloimmune thrombocytopenia. These antiplatelet antibodies were IgG detected by Mixed Passive Hemagglutination (MPHA). In the study of two families, the Yuka antigen was found to be inherited as an autosomal dominant trait. The frequency of the Yuka phenotype in the Japanese population was estimated to be 1.7% (5/300).

Blood Platelets↗

Clinical evaluation of plasma abnormal prothrombin (PIVKA-II) in patients with hepatocellular carcinoma.

The clinical usefulness of plasma abnormal prothrombin, defined as a protein induced by vitamin K absence or antagonist-II: PIVKA-II, as a tumor marker for hepatocellular carcinoma (HCC), was evaluated. Plasma PIVKA-II concentration was determined by an enzyme-linked immunosorbent assay (ELISA) using a monoclonal antibody specific for PIVKA-II. Forty-one (65%) out of 63 patients with HCC had an abnormal PIVKA-II level above 0.13 arbitrary units (AU)/ml; the level was above 0.3 AU/ml in 33 patients (52%) and above 0.5 AU/ml in 27 patients (43%). On the other hand, most of the 282 patients with various liver diseases other than HCC had normal or slightly elevated levels of PIVKA-II. Their values were all below 0.5 AU/ml, with the exception of 2 patients with decompensated liver cirrhosis. The patients with PIVKA-II values above 0.5 AU/ml were strongly suspected of having HCC. Plasma PIVKA-II levels were not related to serum alpha-fetoprotein (AFP) levels, but were above 0.5 AU/ml in 14 (44%) out of the 32 patients whose serum AFP levels were below 400 ng/ml. In some patients with HCC, PIVKA-II was increased throughout the course of the disease, and in others it normalized after surgical resection of the tumor. We conclude that the plasma PIVKA-II assay by the ELISA method using a monoclonal antibody is a useful diagnostic tool for monitoring HCC, particularly in HCC patients with low AFP levels.

Adenoma, Bile Duct↗

Effect of food on bioavailability and pharmacokinetics of theophylline following administration of two sustained release dosage forms: Part I.

Bioavailability and pharmacokinetics of theophylline following administration of a marketed sustained release tablet (Theo-Dur) and a newly designed sustained release tablet (E-0686) have been studied in fifteen healthy volunteers under overnight fasting and non-fasting conditions. Higher concentrations at early absorption phase under fasting conditions than under non-fasting conditions were observed after administration of Theo-Dur, whereas little difference in plasma concentrations was noted when E-0686 was administered under fasting and non-fasting conditions. Bioequivalency was demonstrated depending upon the extent of bioavailability of the two preparations. Compared to the theophylline levels in non-smokers, significantly lower concentrations at elimination phase and AUC0-infinity values were observed in smokers in each treatment (p less than 0.05). E-0686 exhibited almost the same rate constant in dissolution in vitro and in absorption in vivo, while Theo-Dur did not. Therefore, it may be concluded that E-0686 is a well-designed sustained release preparation that releases theophylline in vivo at a given rate which can be easily determined in vitro.

Adult↗