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Biomedical subjects

N Kamatani

Publications and source records attributed to N Kamatani.

At least 163 records · Page 9Linked to original sources
PubMed1989

Clinical aspects of gouty patients in Taiwan.

The mean age of the onset of gout in Taiwan is 49.6 years old. This is very similar to Japan. The female cases made up 5.78% of total cases. This is very similar to the world average of about 5%. As far as laboratory findings are concerned, uric acid had a significant correlation with BUN, creatinine, cholesterol and triglyceride. In our occupation study we found that gout occurs in almost every class of society and no particular group has any immunity.

Adolescent↗
PubMed1989

Erythrocyte adenine PRPP availability in two types of APRT deficiency using silicon oil method.

Erythrocyte phosphoribosylpyrophosphate availability for adenine was measured by silicon oil method previously described. The homozygotes of Japanese type APRT deficiency (n = 6, from 4 families) showed 4.3 +/- 2.7% (mean +/- standard deviation) of adenine PRPP availability and the heterozygotes (n = 5) showed 86.0 +/- 6.0% of adenine PRPP availability. All homozygotes of Japanese type APRT deficiency from 4 unrelated families show the equally decreased adenine PRPP availability and it supports the presumption of the presence of the similar defect of APRT in all families. In a Japanese family of complete APRT deficiency, adenine PRPP availability of the homozygote was undetectable and that of the heterozygote was normal low (54.3% of normal mean activity). The adenine PRPP availability of the heterozygote of complete APRT deficiency was diagnostically different from that of the homozygotes of Japanese type APRT deficiency, despite, these two conditions showed almost the same erythrocyte APRT activity. These results prove that the silicon oil method previously written is the rapid and useful method for differential diagnosis between two types of APRT deficiency.

Adenine↗
PubMed1989

A case of interstitial pneumonia antedating rheumatoid arthritis.

We describe a case report of an interstitial pneumonia in which pulmonary involvement of the both lower lobes mimicked idiopathic interstitial pneumonia (IIP) or bronchiolitis obliterans organizing pneumonia (BOOP). Its appearance antedated clinically apparent rheumatoid arthritis by one month and a half.

Adult↗
PubMed1989

Detection of an amino acid substitution in the mutant enzyme for a special type of adenine phosphoribosyltransferase (APRT) deficiency by sequence-specific protein cleavage.

Generally, if mutant and normal proteins have similar molecular weights and electric charges, they cannot easily be distinguished from one another. We have developed a unique method by which a mutant enzyme of adenine phosphoribosyltransferase (APRT) can easily be distinguished from normal enzyme with nearly identical molecular weight and electric charge. DNA sequencing data have suggested that in this special type of disease (Japanese-type APRT deficiency) there is an amino acid substitution from Met to Thr at position 136 of APRT. Since normal APRT has only one Met residue, the Japanese-type mutant APRT should be a methionine-free protein. Using both an amino acid sequence-specific antiserum against APRT, and specific cleavage of peptide at the methionine residue with BrCN, we could distinguish between normal and mutant proteins. Thus, normal but not mutant APRT was cleaved with BrCN, indicating that the mutant APRT is a methionine-free protein. All tested patients with the Japanese-type APRT deficiency were found to synthesize exclusively methionine-free APRT. Usefulness of this method is not restricted to a single family, as 79% of all the patients with this disease among Japanese, and more than half of all the patients with this disease reported in the world, are likely to have this unique mutation. Thus, not only sequence-specific cleavage of DNA with restriction endonucleases but also that of protein with a chemical agent has been shown to be sometimes useful for the diagnosis and analysis of a genetic disease by careful examination of normal and mutant amino acid sequences.

Adenine Phosphoribosyltransferase↗
PubMed1988

Distribution of patients with 2,8-dihydroxyadenine urolithiasis and adenine phosphoribosyltransferase deficiency in Japan.

2,8-Dihydroxyadenine urolithiasis is caused by genetic deficiencies of adenine phosphoribosyl-transferase. This disease has occurred in a large number of Japanese patients and more than half of all families with this disease are only partially deficient in enzyme activities (Japanese type adenine phosphoribosyltransferase deficiency). To clarify the reasons for the preponderance of Japanese cases we sent questionnaires to 948 Japanese urological departments. The data thus obtained indicated that 76 families had 2,8-dihydroxyadenine lithiasis and of 51 families in which adenine phosphoribosyltransferase activities were assayed 76 per cent were only partially deficient in adenine phosphoribosyltransferase activities. The distribution of the 2,8-dihydroxyadenine families was roughly similar to that of the population in Japan and the rates of the Japanese type adenine phosphoribosyltransferase deficiency families were not significantly different among the various parts of Japan. These data indicate that the wide distribution of the unique mutant gene, APRT*J, that was created many years ago in a Japanese ancestor, explains at least in part the large number of 2,8-dihydroxyadenine lithiasis and adenine phosphoribosyltransferase deficiency families among the Japanese.

Adenine↗
PubMed1988

Human adenine phosphoribosyltransferase deficiency. Demonstration of a single mutant allele common to the Japanese.

Complete adenine phosphoribosyltransferase (APRT) deficiency causes 2,8-dihydroxyadenine urolithiasis. In previous reports, analysis of the kinetic properties of APRT from APRT-deficient Japanese subjects revealed strikingly similar abnormalities suggesting a distinct "Japanese-type" mutation. In this paper, we report studies of 11 APRT-deficient lymphoblast cell lines. Nucleotide sequence analysis of APRT genomic DNA from WR2, a Japanese-type homozygote, identified a T to C substitution in exon 5, giving rise to the substitution of threonine for methionine at position 136. RNase mapping analysis confirmed this mutation in WR2 and revealed that six other Japanese-type homozygotes carry the same mutation on at least one allele. The remaining Japanese subject, who does not express the Japanese-type phenotype, did not demonstrate this mutation. Southern blot analysis showed that all seven Japanese-type subjects were confined to one TaqI restriction fragment length polymorphism (RFLP) haplotype. These studies provide direct evidence for the nature of the mutation in the Japanese-type APRT deficiency.

Adenine Phosphoribosyltransferase↗
PubMed1987

Selection of human cells having two different types of mutations in individual cells (genetic/artificial mutants). Application to the diagnosis of the heterozygous state for a type of adenine phosphoribosyltransferase deficiency.

We have previously reported the establishment and characterization of B cell lines from patients and family members with various types of adenine phosphoribosyltransferase (APRT) deficiencies. These cell lines contain, at the APRT locus, three different alleles (APRT*1, APRT*Q0, and APRT*J) that are clearly distinguishable from each other. From five genetically heterozygous cell lines with two different genotypes (APRT*1/APRTQ0 and APRT*1/APRT*J), we have selected 48 clones resistant to 2,6-diaminopurine. Resistance to this adenine analogue is a characteristic of cells having defects in both of the APRT alleles in individual cells. The mutant clones from a cell line from a complete-type heterozygote had APRT activities close to zero (mean = 0.04 nmol/min per milligram protein) in the cell extracts, while 15 clones from four cell lines from the four Japanese-type heterozygotes had significant enzyme activities (mean = 3.88 nmol/min per milligram protein). Kinetic studies on two of the mutants from two Japanese-type heterozygous cell lines have shown that affinity to substrate 5-phosphoribosyl-1-pyrophosphate was reduced, indicating that APRT in those clones reflected the characteristics of the Japanese-type enzyme. The data presented here indicate that clones we obtained are genetic/artificial mutants, each having a genetic mutation in a single allele (APRT*J or APRT*Q0) and an artificially produced mutation in the other previously functional allele (APRT*1). The present procedure provided the only diagnostic method for Japanese-type APRT heterozygotes (APRT*1/APRT*J).

Adenine Phosphoribosyltransferase↗
PubMed1987

Genetic and clinical studies on 19 families with adenine phosphoribosyltransferase deficiencies.

Adenine phosphoribosyltransferase (APRT) deficiency leading to 2,8-dihydroxyadenine (DHA) urolithiasis has been considered a rare cause of urolithiasis and renal insufficiency. We have examined samples from 19 Japanese families with DHA lithiasis. In 79% of the families, patients only partially lacked hemolysate APRT activities, clearly contrasting with the complete deficiency in all the patients from non-Japanese families so far reported. All patients with DHA lithiasis were homozygotes for defective APRT genes, whether the deficiency was complete or partial. In family studies we found two symptomatic and four asymptomatic homozygous family members. The segregation figures are compatible with the hypothesis of a simple autosomal recessive mode of inheritance. By analyzing the data stored by a large clinical laboratory in Japan, we estimated that 0.00368% of the general population has DHA lithiasis. These data indicate that more than 1% of the general population possess mutant alleles of the APRT gene as heterozygotes. Our present studies indicate that most of the patients with this disease are undiagnosed in Japan, and probably in other countries also.

Adenine↗
PubMed1987

Screening for adenine and hypoxanthine phosphoribosyltransferase deficiencies in human erythrocytes by high-performance liquid chromatography.

A screening method using high-performance liquid chromatography (HPLC) for the simultaneous detection of deficiencies of adenine phosphoribosyltransferase (APRT) and hypoxanthine phosphoribosyltransferase (HPRT) activities in human erythrocytes is described. Both enzyme reactions of APRT and HPRT in lysates treated with a charcoal-dextran were simultaneously carried out in the same reaction tube and the enzyme activities were determined by measuring the increases in absorbance at 260 nm of adenosine and inosine converted from adenosine-5'-monophosphate and inosine-5'-monophosphate with alkaline phosphatase. Adenosine and inosine were separated from adenine and hypoxanthine by a reversed-phase column. The method could detect 1% of normal APRT activity and 0.3% of normal HPRT activity. The within-run coefficients of variation for APRT and HPRT activities were 3.2 and 3.4%, respectively.

Adenine Phosphoribosyltransferase↗
PubMed1987

Cross-resistance to ouabain in a murine leukemia cell variant selected for cis-dichlorodiammineplatinum(II) resistance.

A murine leukemic cell line (R1.1) variant (R1.1/CDDPR-E8) resistant to cis-dichlorodiammineplatinum(II)(CDDP) was also found to be resistant to ouabain, a postulated specific inhibitor of sodium-potassium ATPase. The variant established by the culture of parental cells in step by step increasing concentrations of CDDP, exhibited 11-fold higher resistance to CDDP than the parental R1.1 cells. The present study suggests that a mutational change leading to an alteration in cell membrane characteristics associated with ouabain has also changed the sensitivity of cells against CDDP. Alternatively, the present data may indicate that the cytotoxicity of CDDP is closely linked to its effects on cell membrane.

Animals↗
PubMed1987

Spontaneous production of an interleukin 1-like factor by cloned rheumatoid synovial cells in long-term culture.

We have cloned adherent synovial cells from rheumatoid synovitis. These can be generally divided into three types, including cells that have the characteristic features of dendritic cells (DCs), macrophagelike cells (MCs) and fibroblastlike cells (FCs), as classified by morphology and immunofluorescent staining. The cloned cells were able to divide and were cultured for up to 11 mo without any significant morphological changes. All the cloned cells were HLA-DR+ after gamma-interferon treatment. Spontaneous production of a factor with interleukin 1 activity by the cloned cells was detected even after long-term culture (the ability, on a per cell basis, being in the following order: DC greater than MC greater than FC). These synovial cells may be important for bony destruction in rheumatoid joints.

Arthritis, Rheumatoid↗