Biomedical subjects
Publications and source records attributed to A Ohkubo.
We developed a conceptually new strategy for the coupling method in the phosphoramidite method without protection of nucleoside bases. This strategy, called "proton-block method", significantly reduced side reactions compared with the previous methods.
To elucidate the effects of kojic acid on thyroid function, the compound was given orally to male rats for 4 weeks at 0, 4, 15, 62.5, 250 and 1,000 mg/kg. In 1,000 mg/kg treatment of kojic acid, the rats showed a slight decrease in motility, inhibition of body weight gain, and a decrease in food consumption. An increase in thyroid weight and a morphological change, i.e., hypertrophy of epithelial cells of the thyroid gland follicles, were observed after 1 week of administration. In addition, the uptake of radioactive iodine from blood into the thyroid gland was enhanced and the TCA-precipitable radioactive iodine in the thyroid gland increased in those rats. However, the rates of the iodination in the thyroid gland did not change during the experiment period. Although serum T4 concentration was low in the rats treated with 1,000 mg/kg kojic acid, it was not observed in any changes in TSH concentration. None of these changes were found in the other groups. These observations suggest that massive administration of kojic acid may decrease blood T4 concentration and that thyroid function may be enhanced compensatorily. On the other hand, the absorption of kojic acid was rapid as manifested by the Tmax of blood concentrations of radioactivity, which was as short as 1.0 +/- 0.0 hr, and the t1/2 was 4.8 +/- 0.3 hr. Blood concentrations of radioactivity disappeared nearly completely at 24 hr after administration. This result indicates that the toxic effect observed on the thyroid gland treated with only the largest dosage of kojic acid may depend on a fast decrease following a transient increase of concentration of the compound in the blood.
Using whole blood sample, we examined the correlation between concentration of granulocyte elastase (GEL) in granulocyte obtained by immunoassay and white blood cell counts. The correlation between concentration of GEL and granulocyte cell counts was also examined. The correlation coefficient between concentration of GEL and white blood cell counts was R = 0.87, and that between concentration of GEL and granulocyte cell counts was R = 0.91. The correlation coefficients of outpatients and patients with diseases accompanied by inflammation except for tumors were better than those of inpatients. The GEL concentration in granulocyte using whole blood sample well responded to the white blood cell counts against the tolerance for a short time, such as after operations. Especially on screening tests of diseases accompanied by inflammation and primary care, analysis of GEL in whole blood is not only useful for observation of inflammation and its progress but also suggests possibility of converting GEL to white blood cell counts or granulocyte. Furthermore, because it can be measured by easy-operative latex agglutination turbidimetric method, an easy measurement system can be built. Extended usage of the system as a rapid diagnostic tool on emergency tests in general clinics and hospitals are expected.
Hantavirus is known to cause haemorrhagic fever with renal syndrome (HFRS). Although liver dysfunction has been reported in HFRS, hepatic manifestations of hantaviral infection have not been well described. We describe a case of autoimmune cholangitis in which an exacerbation of hepatitis was associated with hantaviral infection. Seroconversion of both IgG- and IgM-class antibodies to hantavirus was noted coincident with acute exacerbation of hepatitis, which was resolved promptly by treatment with corticosteroid. No extrahepatic manifestations were noted. This case suggests that hantavirus may trigger acute exacerbation of autoimmune liver disease without extrahepatic manifestations and that it may cause community-acquired hepatitis.
Reference preparation for proteins in human serum (RPPHS), also called Certified Reference Material 470 (CRM 470), was prepared by the international Federation of Clinical Chemistry (IFCC) and is intended to serve as a new international plasma protein reference material. It is now being introduced into Japan. RPPHS possesses many excellent properties, including safety, stability, and accuracy in value assignment. Moreover, the physicochemical properties of its proteins are identical to those of fresh serum, giving it immunochemical behavior that is commutable with that of existing reference materials and calibrators in given immunoassays. Reference intervals of 13 serum proteins were determined for the first time using nephelometry and a new working calibrator assigned from RPPHS, which seems certain to play a critical role in the global standardization of specific protein immunoassays.
In southwestern China, small but substantial numbers of patients with acute hepatitis were found without known hepatropic viral infections (hepatitis A, B, C, D or E, cytomegalovirus, Epstein-Barr virus) and were receiving no hepatotoxic drugs. Prevalence of antibodies, both neutralizing and specific immunoglobulin (Ig)M and IgG, to Hantaan virus were evaluated in a cohort of 136 such patients: 83 were of unknown aetiology, 53 had known viral hepatitis and 59 healthy subjects acted as controls. The results showed that the incidence of neutralizing antibody to Hantaan virus in acute hepatitis patients with non-hepatitis A-E virus infections (13 of 83) was significantly higher than in those with A-E infections (0 of 53, P<0.01). Furthermore, the incidence of specific IgM antibody to Hantaan virus in acute hepatitis patients with non-hepatitis A-E virus infections (6 of 83) was significantly higher than in those with A-E infections (0 of 53, P<0.05) and in healthy subjects (0 of 59, P < 0.05). These findings suggest that Hantaan virus may be an important agent, contributing, at least in southwestern China, to a significant number of the cases of acute hepatitis of unknown aetiology. This hantavirus infection resulted in an acute hepatitis, differing from the typical diseases: haemorrhagic fever with renal syndrome (HFRS) and hantavirus pulmonary syndrome (HPS).
Concentrations of vanillylmandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), vanillic acid (VA) and 5-hydroxyindoleacetic acid (5-HIAA) in urine from healthy subjects were determined by a high-performance liquid chromatography system with a mixed-mode (C18/anion-exchange) column and an 8-channel electrochemical detector, in order to study the influence of diet, diurnal variation and age. The urinary excretion of 5-HIAA increased significantly after eating banana, pineapple, tomato, kiwi fruit and walnut. An increase in the urinary excretion of DOPAC and HVA after eating banana and that of VA after taking vanilla was also noted. The urinary excretion of VMA was not significantly influenced by any of the foods examined. The urinary excretion of 5-HIAA in the first-morning urine increased beyond the upper limit of the reference value when banana was taken at 2000 h the previous day. The excretion of all metabolites in the second-morning urine in the fasting state was within respective reference ranges. Diurnal variation of the excretion of VMA, DOPAC, HVA and 5-HIAA in urine was relatively small, but that of VA was large. The concentrations (mmol/mol creatinine) of VMA, DOPAC, HVA, 5-HIAA and VA in the first-morning urine from healthy subjects increased from 7 days after birth to 1 year and then decreased to adult levels at 13 years of age.
Using a nephelometry with a new calibrator in which values were assigned from EU/CRM470, a new international reference preparation, we have established for the first time the reference intervals of 13 different serum proteins in Japanese adults. Based on the NCCLS guideline C28-P, a new statistical and concrete procedure was revised and used for this study. It is clearly shown here that standardisation of serum proteins can be possible under the qualified assay system, making it possible to share the reference intervals among laboratories under well-controlled quality assurance. New aspects of serum protein variations were discovered in relation to physiologic changes and life styles.
Elimination of unnecessary laboratory use is becoming more and more important in the control of the rapid growth of medical costs in Japan. Among several measures to reduce unnecessary laboratory use, advising doctors about rational use of clinical laboratory is effective but not sufficient. At Tokyo University Hospital we have established a system to reduce unnecessary laboratory use. In this system warning about excessive use of laboratory tests appears on the display when a doctor orders more laboratory tests by the console than the maximum number of tests covered by health insurance. With this warning system we can effectively minimize unnecessary use of laboratory tests.
To examine the effects of kanamycin on platelet satellitism and leukocyte adhesion phenomena, we added kanamycin to the blood sample which showed the platelet satellitism and the leukocyte adhesion phenomena. We observed the rapid dispersion of platelets from the surface of leukocyte in platelet satellitism and also the rapid dispersion of leukocyte in leukocyte adhesion by addition of kanamycin (20 mg) in 1 ml of EDTA-anticoagulated blood from a patient with both phenomena. Neither adhesion of platelet nor adhesion of leukocyte was found on microscopical examinations after dispersion. Complete blood cell counts and their histogram patterns after dispersion were almost the same as those just after venipuncture. The dispersion was found just after the addition of kanamycin and no re-adhesion was observed. These findings suggest that kanamycin leads to dispersions of leukocyte-leukocyte, platelet-platelet and leukocyte-platelet adhesion phenomena.
Laboratory tests are indispensable to rational medical care and will play more and more important roles in clinical and preventive medicine. However, progress in laboratory medicine is so rapid that many clinicians feel difficulty in using laboratory tests properly. To keep the quality of medical care high in terms of medical science, many well-trained clinical pathologists and medical technologists are needed to help clinicians use laboratory tests properly. To obtain enough experts in the area of clinical pathology, we should pave the way to clinical pathology for young ambitious people and make efforts to help both young clinical pathologists and clinical technologists feel themselves playing an important role in medical care.
An HPLC system for the simultaneous determination of acidic catecholamine metabolites, related compounds and 5-hydroxyindoleacetic acid (5-HIAA) in human urine was developed. A mixed-mode (C18/anion-exchange) column with isocratic elution using citrate buffer and an eight-channel electrochemical detector were used. Vanilmandelic acid (VMA), 3,4-dihydroxyphenylacetic acid (DOPAC), 4-hydroxy-3-methoxyphenyllactic acid (vanillactic acid, VLA), homovanillic acid (HVA), vanillic acid (VA) and 5-HIAA in urine were determined simultaneously. Detection limits and inter (n = 5) and intra-assay (n = 5) coefficients of variation were satisfactory. The mean of analytical recoveries (n = 3, +/- C.V. (%)) were between 97 +/- 3.2 (VMA) and 105 +/- 4.8 (VA). Correlations between the analytical results for VMA, HVA and 5-HIAA obtained by an established method and the present method were satisfactory. The mean +/- 2 S.D. of the excretion rates of VMA, DOPAC, VLA, HVA, 5-HIAA and VA in urine from healthy adult volunteers were 0.61-4.36, 0.13-1.02, 0-0.35, 0.67-6.55, 0.50-5.14 and 0-0.55 mg/g creatinine, respectively.
We recently reported a genus-specific PCR for the mycobacterial dnaJ gene. In the present study, we have determined the nucleotide sequences of the dnaJ gene from 19 mycobacterial species (Mycobacterium tuberculosis, M. bovis, M. bovis BCG, M. africanum, M. microti, M. marinum, M. kansasii, M. gastri, M. simiae, M. scrofulaceum, M. szulgai, M. gordonae, M. avium, M. intracellulare, M. xenopi, M. fortuitum, M. chelonae, M. hemophilum, and M. paratuberculosis). On the basis of the amplified dnaJ gene nucleotide sequences, we constructed a phylogenetic tree of the mycobacterial species by using the neighbor-joining method and unweighted pairwise grouping method of arithmetic average. We found that the phylogenetic relationship inferred within the slowly growing species was in good agreement with the traditional classification, with three major branches corresponding to Runyon's groups I, II, and III. An exception was M. simiae, which was phylogenetically closer to the cluster including members of Runyon's group III than to that of Runyon's group I. On the other hand, the rapid growers, such as M. fortuitum and M. chelonae, did not form a coherent line corresponding to Runyon's group IV, indicating that our phylogenetic analysis based on the dnaJ gene reflects the phenotypic characteristics such as pigmentation but not the growth rate. Finally, we revealed the species-specific restriction sites within the amplified dnaJ gene to differentiate most of the mycobacterial DNA by a combination of PCR with restriction fragment length polymorphism analysis.
We evaluated the diagnostic usefulness of measurement of the soluble cytokeratin 19 fragment, a new tumor marker, in 391 patients with lung cancer and in 424 patients with benign lung diseases. Serum concentrations of cytokeratin 19 fragment were measured by a sandwich ELISA (CYFRA). The cut-off value was defined as 3.5 ng/ml, which is associated with a specificity of 85% for benign lung diseases. CYFRA had a high sensitivity (57.5%) in all subjects with lung carcinoma, and had a higher sensitivity for squamous cell carcinoma (73.1%, n = 141) than squamous cell carcinoma-related antigen (61.0%). CYFRA was associated with a relatively high sensitivity (42.1%) in early-stage squamous cell carcinoma (stage I, based on the classification of the Japan Lung Cancer Society), but the CYFRA titer was higher in advanced squamous cell carcinoma than in early-stage squamous cell carcinoma. Our findings suggest that CYFRA is potentially useful for diagnosis and monitoring of lung carcinoma, especially for squamous cell carcinoma.
The serum bilirubin concentration is a specific marker of liver disease but the sensitivity is low for detecting liver damage and remains within normal limits in many patients with compensated liver cirrhosis. In liver cirrhosis, portal blood flow is distorted accompanied by a decrease in hepatic clearance of bilirubin. In addition, portosystemic shunting as well as splenomegaly results in an increase in hemolysis and production of bilirubin. These together result in an increase in the concentration of unconjugated bilirubin in serum. In advanced cirrhosis, glucuronyl conjugation of bilirubin and biliary excretion of conjugated bilirubin are markedly impaired and jaundice appears. The concentration of bilirubin in serum thus become a good prognostic marker for patients with incompensated liver cirrhosis.
Six cases of ankylosing spondylitis (AS) complicated with acute anterior uveitis (AAU) were reviewed. Clinical and radiologic findings of these cases were correlated with HLA-B27. All the patients were men; four of them were HLA-B27 positive, and two were B27 negative. The average age of onset was younger in B27+ patients than in B27- patients. Ophthalmologic study showed no definite difference in inflammatory change of AAU between B27+ patients and B27- patients. AAU in B27+ patients was completely cured in three months. A history of low back pain was more apparent in B27+ than in B27- patients. Three out of four B27+ patients showed complete bony ankylosis in sacroiliac joints, whereas no ankylosis was seen in B27- patients. CT scan was useful to demonstrate sacroilitis in cases with equivocal radiologic findings. Spondylitic changes were more extensive in B27+ than in B27- patients. The results support the concept that HLA-B27+ AS and B27- AS are different entities with similar phenotypic expression, and HLA-B27 is an arthritogenic gene in the Japanese population as well.
Identification of tuberculous and nontuberculous mycobacteria by biochemical methods is a long-term process that takes up to 8 weeks for completion and requires expertise to interpret the results. In order to detect and differentiate the major pathogenic mycobacterial species, we developed genus-specific primers that amplify the dnaJ gene from the broad spectrum of mycobacterial species and determined the nucleotide sequences within the dnaJ genes from 19 mycobacterial species (Mycobacterium tuberculosis, M. bovis, M. bovis BCG, M. africanum, M. microti, M. kansasii, M. marinum, M. gastri, M. simiae, M. scrofulaceum, M. szulgai, M. gordonae, M. avium, M. intracellulare, M. xenopi, M. fortuitum, M. chelonei, M. haemophilum, and M. paratuberculosis). On the basis of the dnaJ gene sequences, we developed dot blot hybridization analysis with species-specific oligonucleotide probes for the M. tuberculosis complex. M. avium, M. intracellulare, and M. kansaii, allowing a rapid identification of these species following polymerase chain reaction for the dnaJ gene. We conclude that polymerase chain reaction with the genus-specific primer that amplifies the dnaJ genes and subsequent dot blot analysis with species-specific oligonucleotide probes are most useful for differential diagnosis of tuberculosis and nontuberculous mycobacterial infections.
Effects of granulocyte-colony stimulating factor (G-CSF) on hemograms were studied in the leukopenic phase after chemotherapy on patients with solid malignant tumors and lymphocytic malignancies. The samples were from patients with solid malignant tumors (solid tumor group) and from those with lymphocytic malignancies (lymphocytic malignancy group). In the control group, the increase rate and the decrease rate of the white blood cell count were 1.48 and 0.67, respectively. With the administration of G-CSF, they were 4.99 and 0.29 in the malignant tumor group, and 11.83 and 0.19 changes beyond the range of physiologic fluctuations with the administration of G-CSF. In term of increasing rate, immature myeloid cells were increased more remarkably than mature neutrophil by administration of G-CSF, indicating that the target cells of G-CSF are immature cells, and the increase of immature cells is responsible for the increase of the whole white blood cell count. Though immature myeloid cells with atypical morphology were rarely detected in the solid tumor group, they were observed more frequently in the lymphocytic malignancy group. In this study, we stress that the information about the history of G-CSF administration is indispensable for quality control of hemogram examinations.