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Biomedical subjects

K Ichida

Publications and source records attributed to K Ichida.

33 records · Page 2Linked to original sources
PubMed1993

Cloning of the cDNA encoding human xanthine dehydrogenase (oxidase): structural analysis of the protein and chromosomal location of the gene.

The primary structure of human xanthine dehydrogenase (hXDH) was determined by cloning and sequence analysis of the cDNAs encoding the enzyme. The nucleotide (nt) sequence has an open reading frame of 3999 nt encoding a protein of 1333 amino acids (aa) with a calculated M(r) of 146,604. The deduced aa sequence of hXDH is homologous to the previously reported rat XDH (rXDH) and Drosophila melanogaster XDH sequences with identities of 90.2 and 52.0%, respectively. The aa residues involved in both the reversible and the irreversible conversion from the dehydrogenase type to the oxidase type of rXDH are completely conserved between the rat and the human enzymes. This implies that the molecular mechanisms of the conversion of hXDH from dehydrogenase to oxidase are common to those of the well-characterized rXDH. Five sequence variations were detected in the isolated cDNA clones. Spot blot hybridization using flow-sorted human chromosome revealed that the hXDH-encoding gene (hXDH) was located on chromosome 2.

Amino Acid Sequence↗
PubMed1993

A study of uric acid metabolism and gouty arthritis in patients with polycystic kidney.

It has been found that polycystic kidney (ADPKD) is often associated with gout. On the other hand, there are reports describing that the hyperuricemia (HU) seen in ADPKD corresponds to a reduction in renal function. We investigated the uric acid metabolism in 44 patients with ADPKD (age, 50 +/- 12.8 years; CCR, 50.5 +/- 41.1 ml/min) at our hospital. From among these 44 patients, 14 with a CCR of 80 ml/min were selected. Their data for uric acid metabolism were compared against those from the previous year's studies on various disease types (114 normal subjects, 70 with membranous nephropathy, 175 with IgA nephritis, 122 with gout, 137 with asymptomatic hyperuricemia, and 42 with diabetes mellitus). Among the 44 patients with ADPKD, the serum uric acid (SUA) was 7.7 +/- 1.9 mg/dl and HU affected 28 (63.6%). The incidence of gouty arthritis was also high (6 patients, 13.6%), revealing a positive correlation between SUA and CCR. Compared with membranous nephropathy and IgA nephritis, ADPKD exhibited an accentuated increase in SUA associated with a reduction in CCR. It is believed that this represents a factor for a high incidence of complications of hyperuricemia and gouty arthritis in ADPKD in contrast to other diseases. However, no increase in the production of uric acid was noted in ADPKD.

Adult↗
PubMed1991

[A study on treatment of hyperuricemia--effects and kinetics of allopurinol and oxipurinol].

In order to study the effects and pharmacokinetics of allopurinol (hereafter abbreviated to allo.) and oxipurinol (hereafter abbreviated to oxi.) six normal human subjects were given a single oral dose of either allo. (300mg) or oxi. (600mg), followed by serial determinations of serum and urinary levels of allo., oxi., uric acid, hypoxanthine (hereafter abbreviated to hx.) and xanthine (hereafter abbreviated x.) over a six-hour period. With a dose of 300mg of allo. or 600mg of oxi., the patterns of serum uric acid were similar. When 300mg of allo. was given, however, a reduction in the serum uric acid level occurred earlier. Additionally, it was found that urinary excretion of oxi. generally paralleled the plasma concentration. Allo. administration resulted in rises in plasma concentration of x., and urinary excretion of x. and hx. Oxi. administration, on the other hand, did not cause significant changes in the plasma content of x. or urinary excretory volume of hx. Only a slight increase was noted in the amount of x. excreted in the urine. When allo. was compared against oxi., pharmacokinetics of oxypurines, especially x. were found to differ markedly. The results suggested that differences in the reaction sites, varied intra- and extra-cellular distributions of allo. and oxi., and different effects on purine biosynthesis contribute to the aforementioned discrepancies.

Adult↗
PubMed1989

[Uric acid metabolism in patients with chronic glomerulonephritis].

Serum uric acid (SUA), creatinine clearance (Ccr), urinary excretion of uric acid (UUAV) and uric acid clearance (CUA) were determined in 357 patients with IgA nephritis (IgAN) and 81 patients with membranous nephropathy (MGN) in an attempt to clarify uric acid metabolism in patients with chronic glomerulonephritis, and UUAV/Ccr and CUA/Ccr levels were measured to investigate their correlations. As a result, hyperuricemia that could hardly be explained with a decline of Ccr alone was recognized in many cases, since the patients with hyperuricemia exceeding 7.0 mg/100 ml of SUA registered even as high as 25.5% in IgAN and 33.3% in MGN, whereas those with the Ccr levels higher than 80 ml/min registered 22.3% in IgAN and 38.0% in MGN. Although the SUA level increased and the UUAV and CUA levels decreased along with a decline of Ccr in IgAN, no similar trends were recognized in MGN. When the distribution of UUAV was studied in the patients with the Ccr levels higher than 80 ml/min, the patients whose UUAV levels higher than 800 mg/24 hrs that suggested excessive uric acid production were markedly as low as 3.9% in IgAN and 3.7% in MGN. Thus, the cause of hyperuricemia could not be attributed to an amount in the uric acid production. On the other hand, the patients whose CUA levels lower than 6.0 ml/min in the distribution of CUA that suggested a decrease of uric acid excretion registered 47.4% in IgAN and 63.0% in MGN, respectively, which equally appeared to be a type of lowered excretion in a majority of patients whose hyperuricemia was recognized in IgAN and MGN. The mechanism of the lowered excretion of uric acids from the kidney despite the normal level of Ccr has yet to be clarified.

Adult↗
PubMed1989

Malignant hypertension in three siblings.

We encountered three siblings (one female and two males) whose clinical manifestations were consistent with those of malignant hypertension (MH). Renal biopsies were obtained from two of the patients, and an autopsy from the third. The light microscopic findings from all three cases were characterised by marked intimal thickening with concentric layering of collagen and cellular proliferation in the interlobular arteries. Findings, on examination of optic fundi, including retinal haemorrhages, exudates and papilloedema were also consistent with malignant hypertension. The two male patients progressed to develop renal failure. These cases strongly suggest the existence of a rare familial form of primary malignant hypertension.

Adult↗
PubMedDate not supplied

Pitfalls in fine needle aspiration cytology of breast tumors. A report of two cases.

Two cases of fibroadenoma that were cytologically misdiagnosed as mucous carcinoma are reported. The reason for this misdiagnosis was the presence of mucus in the background of the smears. Cytologically, even if plenty of mucus is present in a smear, careful observation of the content of the mucus is necessary. A group of stromal cells in mucus or of epithelial cells dissociated from mucus suggests fibroadenoma with a mucous change in the fibromatous tissue.

Adenocarcinoma, Mucinous↗