[Genetic testing as clinical tests].
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Biomedical subjects
Publications and source records attributed to I Ueno.
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A new dysplasminogen, plasminogen Kanagawa-I, was identified in a healthy male with no previous thrombotic episodes. His plasma plasminogen (PLG) activity was 51.4% of that of normal pooled plasma (reference interval 70-130%) and the antigen level was 94.2% of that of normal pooled plasma (reference interval 80-150%). Nucleotide sequencing revealed a heterozygous G to A transition in exon 18, which resulted in an amino acid substitution of G732R. Both the proband's father and paternal grandfather were heterozygous for this mutation. Interestingly, the grandfather was found to be a compound heterozygote for plasminogen Kanagawa-I and Tochigi (A601T), so that his plasminogen activity and antigen level was 7.7% and 87.2% of that of normal pooled plasma, respectively. However, he has never been affected by significant thrombosis.
Human platelet-specific antigens (HPAs) are found on platelet membrane glycoproteins and are the target of platelet alloantibodies that mediate platelet destruction in neonatal alloimmune thrombocytopenia (NAIT), post-transfusion purpura (PTP) and refractoriness to platelet transfusion therapy. The biallelic polymorphism of all HPA systems is known to be due to a substitution of a single base pair. This study was performed to investigate the frequency of the HPA genes in Koreans, based on these substitutions. The genotypes of eight HPA systems were determined by polymerase chain reaction using sequence-specific primers (PCR-SSP) for HPA-1, -2, -4, -5, and -8 and restriction fragment length polymorphism (RFLP) for HPA-3, -6, and -7. The gene frequencies obtained from 200 unrelated Koreans were 0.99 and 0.01 for HPA-1a and -1b, 0.92 and 0.08 for HPA-2a and -2b, 0.55 and 0.45 for HPA-3a and -3b, 0.99 and 0.01 for HPA-4a and -4b, 0.98 and 0.02 for HPA-5a and -5b, and 0.98 and 0.02 for HPA-6a and -6b. All the individuals tested were homozygotes for HPA-7a and HPA-8a. It has been reported that the HPA-1b antigen is extremely rare (less than 0.3%) in Oriental populations, but this study suggests that the frequency of this antigen in Koreans (2.0%) is higher than in Japanese and Chinese populations.
Generation of free radicals in the reaction of ozone with blood samples and related salt solutions was investigated in vitro by using ESR spin-trapping technique with DMPO. In the reactions of low levels of ozone, a carbon-centered radical was spin-trapped with DMPO, giving rise to the 6-line ESR signal in both whole blood and blood plasma. In the blood plasma, DMPO-spin adduct of hydroxyl radical (DMPO-OH) was detected together with the spin adduct of carbon-centered radical. The present spin-trapping study demonstrates that, when exposed to ozone, 0.9% NaCl solution in the presence of DMPO gives rise to the formation of DMPO-OH. The addition effects of ethanol, which is a .OH scavenger, into the NaCl solution reveal that DMPO-OH is produced by the reaction of DMPO with both .OH and unidentified oxidants originated from the reaction of Cl- and ozone. Based on these observations, we consider that .OH is generated similarly in the blood plasma exposed to ozone. The ESR study of DMPO-spin adducts in the ozone-exposed aqueous solution of NaOCl indicates that Cl- reacts with ozone to give ClO-. Presumably, further oxidation of ClO- by ozone leads to the formations of .OH and the unidentified oxidants.
To establish an effective and reliable system for the detection of p53 mutations, we evaluated the detection efficiencies of nonisotopic polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP), fluorescence in situ hybridization (FISH), and immunohistochemistry. Ten cell lines (AsPc1, BxPc3, Miapaca2, Panc1, Colo320-011, Lovo, MCF7, LNCaP, HL-60, and Daudi), a peripheral blood sample from a patient with a p53 germline mutation (p53GML), and a normal peripheral blood sample were used for examination. Direct nucleotide sequencing identified p53 mutations in 7 of 12 samples (AsPc1, BxPc3, Miapaca2, Panc1, Colo320-011, HL-60, and p53GML). The nonisotopic PCR-SSCP detected anomalies of the PCR fragments in 5 cell lines. In the FISH analysis, 2 cell lines exhibited loss of heterozygosity of the p53 locus. Immunohistochemistry detected an accumulation of the abnormal p53 in 4 cell lines. The combination of these 3 methods produced no false-negative or false-positive results. This combination may be an excellent and beneficial system for the clinical diagnosis of the various human cancers.
The COBAS Amplicor system is an automated diagnostic PCR system which contains a PCR internal control (P. I. C.) template to monitor the amplification. The applicability of COBAS Amplicor HCV was examined using sera of patients with hepatitis. Furthermore, the effects of possible interfering substance (total protein, triglyceride, hemoglobin, glucose, total bilirubin, heparin, lysis reagent including guanidium) on HCV-RNA detection were investigated. The sensitivity of COBAS Amplicor HCV was equivalent to the manual method of Amplicor HCV, moreover all of the results in 54 clinical samples analyzed on both COBAS Amplicor HCV and Amplicor HCV were in agreement. Detection sensitivity of HCV-RNA decreased in the presence of total bilirubin and heparin. Ten and 25mg/dl of total bilirubin affected HCV-RNA detection but did not affect P. I. C. This result suggested that total bilirubin interfered with the protein denature caused by the lysis reagent. Fifteen U/ml of heparin in the sample completely inhibited amplification both of the HCV-RNA and P. I. C. One U/ml of heparin did not affect amplification, but heparinized blood samples should not be used for the detection of HCV-RNA. To examine the effect of possible carry over contamination on the lysis reagent which contains guanidium, various concentrations of lysis reagent in P. I. C. were tested. RT-PCR was inhibited by 1/500 volume contamination of lysis reagent in specimen diluent. Other substances did not affect the sensitivity. Our results indicate that the carryover contamination of lysis reagent cause more "false negative" results than interfering substances in sera. In conclusion, HCV-RNA detection system containing P. I. C., such as COBAS Amplicor HCV, will become a very useful to differentiate "false negative" and "true negative" result.
Detection of the viral genome in serum is the most reliable way to analyze HCV viremia. In the present study, we evaluated the availability of a new detection kit for HCV-RNA, Amplicor HCV, which is based on the RT-PCR microplate hybridization protocol. The procedure of Amplicor HCV is simple, unlike the conventional RT-nested-PCR method. Although Amplicor HCV assay exhibited the lower sensitivity than the the conventional RT-nested-PCR method (10 x for HCV type 1a, 1b and 2b; 10(3) x for type 2a), Amplicor HCV assay could detect the HCV-RNA in all HCV-RNA positive cases by conventional RT-nested PCR method, except for one case who contained low concentration of HCV-RNA (10 copies/ml). The coincidence rate was 99.2% in 120 clinical samples between two assays. Amplicor HCV assay, moreover, could efficiently evaluate the viremia regardless of anti-HCV-2 antibody titer. This assay was useful for monitoring the effect of interferon therapy during and after administration. These results suggest that Amplicor HCV has an excellent availability for the clinical laboratories.
Abnormal hemoglobin is one of the most frequent genetic disorder, of which about 700 variants have been reported in the world. Some abnormal hemoglobins such as HbS and HbC are endemic among limited human populations. We have found five subjects with abnormal hemoglobin in routine hematology analysis using an automated system Sysmex NE-7000. We isolated genomic DNA from the peripheral blood leukocyte of each subject, and amplified a 558 bp fragment of DNA including the entire exons 1 and 2 as well as intron 1 of the beta-globin gene. The amplified DNA fragments were subjected to direct sequencing by the dideoxy termination method on an automated DNA sequencer. The sequence analysis showed the abnormalities including HbA/C, HbS/C, HbE/E, and HbA/G-Szuhu. In the present study, we report a simple method for the mutual differentiation of these abnormal hemoglobins using restriction fragment length polymorphism (PCR-RFLP) method. Digestion of the amplified fragments described above with a restriction enzyme MnlI gave different RFLP patterns for HbA, HbC or S, HbE, and for HbG-Szuhu. RFLP using another enzyme, DdeI, could distinguish for HbS from HbC.
Nitric oxide (NO) generation in murine macrophages was determined in real time using the electron paramagnetic resonance (EPR) spin trapping method. An iron complex of N-methyl D-glucamine dithiocarbamate was utilized as the spin trap. This spin trapping compound reacts with NO in solution to form a specific room-temperature stable, mononitrosyl complex which is readily detected and identified by EPR spectroscopy. Mouse peritoneal macrophages were placed in an EPR sample-cell and activated by lipopolysaccharide and gamma-interferon at 37 degrees C, followed by an additional incubation in oxygenated medium without these activation agents. After various incubation periods, spin trap solution was infused to replace the medium in the sample-cell, and the time-evolution of the EPR signal of the spin adduct (NO-complex) was recorded. Rates of NO generation were calculated based upon the initial slopes of the increase in the EPR intensity with time. In comparison to the NO (or NO2-) generation rate obtained under similar experimental conditions using the Griess reaction assay, the spin trapping method was found to be more sensitive, with a lowest limit of the detection of 3 pmol/min. In addition, by using the spin trapping method, NO generation from the same cells could be measured consecutively during various stages of activation, because infusion of the spin trap solution did not affect the viability of macrophages.
Fibrinogen Matsumoto II is a hereditary dysfibrinogenaemia identified in a woman with Basedow's disease and a bleeding tendency. Coagulation tests of the patient's plasma revealed a prolonged thrombin time and a decreased fibrinogen level determined by functional method. Release of fibrinopeptide A and B was normal, whereas fibrin monomer polymerization was delayed. Fibrinogen gamma-chain gene of the propositus was heterozygous for a missense mutation that resulted in Asn-->Lys substitution at codon 308. Though the same amino acid substitution was also attributed to fibrinogen Kyoto I and Bicetre II, fibrinogen Matsumoto II showed different clinical manifestations from them.
Fibrinogen Matsumoto I is a novel hereditary dysfibrinogen identified in a 1-year-old boy with Down's syndrome. Though he showed no apparent bleeding or thrombotic tendency, he had a congenital heart disease. Preoperative coagulation tests of his plasma revealed a prolonged thrombin time and the fibrinogen level determined by the thrombin time method was markedly decreased. Molecular weight of fibrinogen chains showed apparently normal A alpha-, B beta-, and gamma-chains. The rate of fibrinopeptide release was normal, whereas fibrin polymerization was delayed. Fibrinogen gamma-chain gene fragments from the propositus were amplified by polymerase chain reaction then sequenced. The triplet GAT, coding for the amino acid residue gamma 364, was replaced by CAT, resulting in the substitution of Asp-->His. This residue is adjacent to the Tyr-363 that is demonstrated to be the primary site for fibrin polymerization. Our results indicate that the residue gamma 364 Asp is essential for normal polymerization of fibrin monomer.
Based on the DNA fragmentation profile in gel electrophoresis and the morphological changes in electron microscopy, the induction of apoptotic nuclear changes by mycotoxins and other microbial products, in total 31 chemicals, was investigated in HL-60 human promyelotic leukemia cells, along with the cytotoxicity tests with 3-[4,5-dimethylthiazol-zyl]-2,5-diphenyltetrazolium bromide (MTT) and trypan blue exclusion. Among the chemicals tested, trichothecenes (T-2 toxin, roridin A, nivalenol, deoxynivalenol), certain anthraquinones (luteoskyrin, skyrin, 2-hydroxyemodin), diketopiperazines (emethallicin A, emestrin), isocoumarins (ochratoxin A, citrinin), lactone (penicillic acid), dihydrobisfuran (aflatoxin B1), potassium ionophore (valinomycin), and an inhibitor of interleukin-2 synthesis (cyclosporin A) were positive for the induction of DNA fragmentation. No DNA fragmentation was observed under the present conditions with fumonisin B1, cyclic peptides (cyclochlorotine, phalloidin, microcystin-LR), certain anthraquinones (emodin, chrysophanol, rugulosin), and others (sterigmatocystin, cytochalasin A, griseofulvin, fusaric acid, kojic acid, rubratoxin B, butenolide, wortmannin, FK506, and sphingosine). The apoptotic changes in the cells exposed to T-2 toxin and luteoskyrin were confirmed by electron microscopic observation. Detailed experiments on dose and time dependencies revealed that T-2 toxin induced the apoptosis at 10 ng/ml (= 4 x 10(-8) M) levels within 2-6 hr without significant cytotoxicity evaluated by the dye exclusion and MTT.
Luteoskyrin is a hepatotoxic and hepatocarcinogenic bisdihydroanthraquinone produced by Penicillium islandicum Sopp. By observing the EPR spectra of DMPO-spin adducts and luteoskyrin semiquinone radical, we investigated in vitro whether luteoskyrin is reduced to its semiquinone radical leading to the generation of active oxygen species in redox systems catalyzed by NADPH-dependent cytochrome reductases of the liver. We found (1) the formation of luteoskyrin semiquinone radical in the NADPH-cytochrome P-450 reductase system under anaerobic conditions, (2) the generation of O2- in the systems composed of luteoskyrin, NAD(P)H, and either rat liver microsomal NADPH-cytochrome P-450 reductases or submitochondrial particles and (3) dicoumarol showed no effect on the O2- generation in the case of submitochondrial particles. From these results we proposed that luteoskyrin liver injuries are induced by the active oxygen species generated in the process of autoxidation of luteoskyrin semiquinone radical which is produced in the one-electron redox systems catalyzed by the liver NAD(P)H-dependent cytochrome reductases.
The unique capabilities of EPR spin trapping of nitric oxide based on a ferrous-dithiocarbamate spin trap have been demonstrated in a study verifying the source of the nitrogen and oxygen atoms in nitric oxide produced from activated macrophages. Spin trapping experiments were performed during nitric oxide generation from activated mouse peritoneal macrophages using the ferrous complex of N-methyl D-glucamine dithiocarbamate as a spin trap. When 15N-substituted arginine was given to the activated macrophages in the presence of the spin trap, a characteristic EPR spectrum of the nitric oxide spin adduct was obtained, which indicates the presence of the 15N atom in the nitric oxide molecule. The hyperfine splitting (hfs) constant of the 15N nucleus was 17.6 gauss. When 17O-containing dioxygen (55%) was supplied to the medium, an EPR spectrum consistent with the 17O-substituted nitric oxide spin adduct was observed in the composite spectrum. The hfs of 17O was estimated to be 2.5 gauss. The 14NO spin adduct observed after prolonged incubation in the medium which contains [15N]L-arginine as the only extracellular source of arginine demonstrates that arginine is recycled through its metabolite in activated macrophages.
Two overlapping cDNA clones (1,991 bp and 736 bp, respectively) encoding the precursor of human mitochondrial very-long-chain acyl-coenzyme A dehydrogenase (VLCAD) were cloned and sequenced. The cDNA inserts of these clones together encompass a region of 2,177 bases, encoding the entire protein of 655 amino acids, including a 40-amino acid leader peptide and a 615-amino acid mature polypeptide. PCR-amplified VLCAD cDNAs were sequenced in cultured fibroblasts from two VLCAD-deficient patients. In both patients, a 105-bp deletion encompassing bases 1078-1182 in VLCAD cDNA was identified. The deletion seems to occur due to exon skipping during processing of VLCAD pre-mRNA. This is the first demonstration of a mutation causing VLCAD deficiency. Quantitative cDNA expression of normal human VLCAD was performed in the patients' fibroblasts, using vaccinia viral system, which demonstrated that the deficiency of the normal VLCAD protein causes impaired long-chain fatty acid beta-oxidation activity in the patients' fibroblasts. In patient fibroblasts, raising VLCAD activity to approximately 20% of normal control fibroblast activity raised palmitic acid beta-oxidation flux to the level found in control fibroblasts, which may offer important information for the rational design of future somatic gene therapy for VLCAD deficiency.
The frequency of isolation of Mycobacterium tuberculosis has reported to be decreased, however, Mycobacterium species including MOTT (Mycobacteria other than M. tuberculosis complex) still remain to be the important bacteria causing opportunistic infection. Two clinical procedures have long been adopted to date for the detection of acid fast bacteria belonging to the family Mycobacteriaceae. One is the direct microscopic examination of the specimen stained by Ziehl-Neelsen method, which is rapid, but is relatively insensitive and less specific. And another is a time- consuming culturing technique on slants of Ogawa's media, which takes 4 to 8 weeks of incubation. Recently, various methods to detect mycobacterial DNA have been reported. However, they require a complicated and tedious processes. We represent here a simple method for the detection and identification of Mycobacteria (M. tuberculosis, Mycobacterium marinum, Mycobacterium scrofulaceum, Mycobacterium intracellulare, Mycobacterium avium, Mycobacterium fortuitum, Mycobacterium chelonae) using PCR-RFLP method for the 65kDa antigen with high sensitivity and specificity. This includes the amplification of Mycobacterial gene encoding a part of the 65kDa antigen. Subsequently, we sequenced the region amplified by PCR from the seven standard bacterial strains. As the results, we found that HaeIII restriction enzyme is suitable for the prompt and easy discrimination among the seven strains examined. These findings led us to conclude that this method is time-saving and possibly applicable for the rapid detection of Mycobacterial species including MOTT from clinical specimens in routine clinical laboratories.
UNLABELLED: The authors studied the relation between home parenteral nutrition (HPN) and medical economy. The items of study are 1) cost benefit of HPN compared with TPN, 2) hospital intention to promote HPN, 3) economical demerits for outpatients receiving HPN. RESULTS: 1) HPN had the advantage of cost benefit compared with TPN in reimbursement; however, hospitals did not have such an intention. 2) It is necessary for advanced home care to improve reimbursement in the health insurance system; and in the existing situation, hospitals do not profit from HPN. 3) Home care companies are unprofitable because of nursing visits and reimbursement issues which do not ease legal restrictions. 4) HPN in the present situation depends on the ability of patients to pay and the ability of care givers to provide care.
Zitter rats develop a genetic spongiform encephalopathy characterized by edematous changes in their brains. In order to elucidate the involvement of reactive oxygen species in this process we examined age-related alterations of the activities of the enzymes which metabolize reactive oxygen species. Activities of superoxide dismutase (SOD), D-amino acid oxidase (D-AAO), glutathione peroxidase (GSH-Px) and catalase in the brain and the liver of zitter rats are compared with those of control SD/J rats. In the brain of adult zitter rats which show degenerative changes, significantly enhanced activities of SOD and D-AAO were obtained, whereas activity of catalase was lower than that of the SD/J rats. Prominent abnormalities in catalase and D-AAO but not in SOD activity were demonstrated before or at the same time as the appearance of the morphological vacuolation in the brain of suckling zitter rats. There was no difference in GSH-Px activity between the brains from zitter and SD/J rats. These results suggest that the alteration of hydrogen peroxide (H2O2)-metabolism in microperoxisomes may play an important role in the initiation of degenerative changes in the brain of zitter rats. Enhanced SOD activity observed in the brain of adult zitter rats may be a compensatory response to the high superoxide anion produced in the course of cell damage caused by the H2O2 stagnation. Also, more SOD might produce more H2O2.