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Biomedical subjects

K Shimokado

Publications and source records attributed to K Shimokado.

50 records · Page 3Linked to original sources
PubMed1989

Concomitant secretion of big endothelin and its C-terminal fragment from human and bovine endothelial cells.

A specific radioimmunoassay (RIA) for the carboxyl-terminal fragment (CTF) of big porcine endothelin (pET), an intermediate form of pET, was established to characterize big ET-like and its CTF-like immunoreactivity (LI) secreted from cultured bovine and human endothelial cells (EC). The antibody used crossreacted equally with big pET(1-39) and its CTF(22-39), but not with pET(1-21). Serial dilution curves of the culture media from bovine and human EC were parallel to that of standard CTF. Reverse-phase HPLC coupled with RIAs for big ET and ET of the culture media from bovine and human EC revealed essentially the same elution profiles: two major CTF-LI components, one corresponding to big pET(1-39) and the other to its CTF(22-39), in addition to one major ET-LI component corresponding to pET(1-21). The amounts of CTF-LI were almost equal to that of ET-LI on a molar basis. These data suggest that big ET is processed by a putative ET converting enzyme to yield its CTF and the mature ET(1-21) in EC.

Amino Acid Sequence↗
PubMed1986

HLA in Buerger's disease.

Recent studies have focused on the possible genetic factor(s) in the pathogenesis of Buerger's disease as well as in Takayasu's disease. We investigated HLA-A, B, C, DR, and DQ antigens in 59 patients with Buerger's disease to confirm statistically significant high frequencies of Aw24, Bw40, Bw54, Cw1, and DR2 antigens and a low frequency of DR9 and DRw52 as compared with those in 152 normal Japanese individuals. As the haplotpye Aw24-Bw54-Cw1-DR4 is known to be common among Japanese, a significantly high frequency of haplotype Bw54-DR2 found in cases of Buerger's disease, instead of that of Bw54-DR4, may suggest a possible cross-linkage occurrence in chromosome 6, which could prove to be an important causative phenomenon in the pathophysiology of Buerger's disease.

Disease Susceptibility↗
PubMed1985

A significant part of macrophage-derived growth factor consists of at least two forms of PDGF.

The macrophage has been suggested to be responsible for the connective tissue cell proliferation that accompanies most chronic inflammatory responses. One of the secretory products of activated macrophages is MDGF, a growth factor (or factors) for fibroblasts, 3T3 cells, smooth muscle, and vascular endothelium. This report demonstrates that a significant portion of the mitogenic activity for 3T3 cells secreted by cultured human alveolar and peritoneal macrophages is due to a molecule (or molecules) similar to platelet-derived growth factor (PDGF). Two size classes (approximately 37,000-39,000 and 12,000-17,000 daltons) of mitogenically active PDGF-like molecules are detected by two criteria--antigenic similarity with PDGF and ability to compete with 125I-PDGF for high-affinity binding to the PDGF receptor. The presence of mRNA for the B chain of PDGF is demonstrated by Northern analysis, and de novo synthesis of these molecules by activated macrophages is shown by immunoprecipitation of 35S-labeled proteins with anti-PDGF IgG.

Animals↗
PubMed1982

Changes in the plasma levels of thromboxane B2 and cyclic nucleotides in patients with Takayasu disease.

Plasma thromboxane B2 (TXB2), cyclic AMP and cyclic GMP levels in 31 women with Takayasu disease were measured and findings were compared with data on 34 age-matched healthy Japanese. Platelet aggregation determined by the screen filtration pressure (SEP) method and pulmonary lesions assessed by scintillation were studied in 21 patients. Plasma TXB2 levels in patients with Takayasu disease were 265.8 +/- 20.4 pg/ml, which were statistically higher than the levels of 196.3 +/- 10.7 in healthy controls. On the contrary, cyclic AMP levels in the patients were 9.6 +/- 0.7 pmols/ml, statistically lower levels than 13.5 +/- 1.0 seen in the healthy controls. A positive correlation among cyclic AMP, cyclic GMP and TXB2 levels was confirmed only in the controls. SEP values in the patients with pulmonary lesions were significantly higher than in those without lesions and also in the controls. A positive correlation was obtained between SEP and TXB2 levels in healthy controls, but not in the patients. Thus, thromboxane A2 may play an important role in the pathology of Takayasu disease.

Adult↗
PubMed1981

Plasma thromboxane B2 levels and atherosclerotic disorders.

In our ongoing studies of the interrelationship between platelets and the vascular wall we found that an accurate estimate could be made of the clinical condition and more effective therapy prescribed when we monitored alterations in the plasma levels of TXB2. For this purpose we devised a radioimmunoassay with I125-TXB2-Tyramide. Patients with ischemic heart disorders, cerebral apoplexy, diabetes mellitus, Buerger's disease, Takayasu disease etc., all had statistically high levels of TXB2 as compared with healthy controls. In particular, patients with myocardial infarction, cerebral thrombosis and/or hemorrhage all revealed increases in levels of TXB2 and these levels increased in parallel with a worsening of the clinical condition, and there was always a re-increase in TXB2 level before a recurrence of an attack. As plasma TXB2 levels clearly reflect thrombogenic disorders, the assessment of these levels on a routine basis, enables a more accurate diagnosis, an indication of possible recurrences, and more effective chemotherapy and rehabilitation.

Adolescent↗