RESUMEN

AIMS: Circulating progenitor cells such as CD34+ cells play a key role in maintenance of vascular endothelial function and neovascularization, and a decrease in the number of CD34+ cells is associated with cardiovascular disease. However, the contribution of circulating progenitor cells to microvascular disease, such as diabetic nephropathy, is unclear. This study was therefore designed to clarify the association between diabetic nephropathy and circulating CD34+ cells. METHODS: We measured circulating CD34+ cell numbers in 85 Type 2 diabetic patients aged 40-70 years with normo- and microalbuminuria and determined the association with urinary albumin excretion rate (UAER). RESULTS: The number of circulating CD34+ cells significantly correlated with log UAER (r = -0.289, P = 0.008). Furthermore, in patients with low numbers of CD34+ cells (0.68 > cells/microl, lowest quartile of CD34+ cell number) UAER increased significantly after 12 months compared with baseline [from 34.3 +/- 7.0 to 53.6 +/- 10.8 mg/g creatinine (gCr), P < 0.05], whereas in patients with a high number of CD34+ cells (1.0 < cells/microl, highest quartile of CD34+ cell number) UAER did not change (from 16.7 +/- 4.8 to 20.1 +/- 3.0 mg/gCr). CONCLUSIONS: These results suggest that a decreased number of circulating CD34+ cells is involved in the progression of diabetic nephropathy and may be a predictor of the disease.

Asunto(s)

RESUMEN

Recombinant rat squalene epoxidase (rSE) was expressed in E. coli and purified to an apparent homogeneity. This expression system was constructed using squalene epoxidase (SE) cDNA in which nucleotides coding 99 amino acids in the N-terminal were deleted and nucleotides coding hexa-histidine in the C-terminal were added. Purification was carried out using Ni-chelate affinity agarose and Cibacron Blue Sepharose column chromatography. Purification was achieved 100-fold over the crude E. coli extract with a yield of about 50%. The purified enzyme demonstrated a single band on SDS-polyacrylamide gel electrophoresis. The enzyme showed no distinct absorption spectrum in the visible regions. The properties of rSE were compared with those of rat liver microsomal SE. The requirement of the co-factors, the S105 fraction or Triton X-100, and NADPH-cytochrome c reductase, the pH dependency for enzyme activity, and the sensitivity to NB-598 seen with both enzymes suggest that rSE has properties very similar to rat microsomal SE. 2,3-Oxi-dosqualene (OSQ) and 2,3;22,23-dioxidosqualene (DOSQ) were formed by rSE in a completely reconstituted system. It is suggested that recombinant squalene epoxidase catalyzes the conversion of squalene to 2,3-oxidosqualene and of 2,3-oxidosqualene to 2,3;22,23-dioxidosqualene.

Asunto(s)

RESUMEN

FY-087 (N-[2-[N'-pentyl-(6,6-dimethyl-2,4-heptadiynyl)amino]ethyl]- (2-methyl-1-naphthylthio)acetamide) was found to be a competitive inhibitor of human microsomal acyl coenzyme A:cholesterol acyltransferase (ACAT) with an IC50 value of 0.11 microM. Under our assay conditions, other ACAT inhibitors tested, specifically YM-750, E-5324, and melinamide, all of which are now in phase I clinical trials or in clinical use in Japan, inhibited this enzyme with IC50 values of 0.18, 0.14, and 3.2 microM, respectively. FY-087 also inhibited ACAT in acetyl-low density lipoprotein loaded human macrophages (THP-1 cells) with an IC50 of 0.17 microM. Following the oral administration of FY-087 (30 mg/kg) to rats, the plasma concentration of FY-087 reached 0.42 microgram/mL after 2 hr. This concentration of FY-087 was enough to inhibit blood vessel ACAT activity. Cholesterol-lowering and anti-atherogenic effects of FY-087 were examined using C57BL/6J mice fed an atherogenic diet. In this mouse model, treatment with FY-087 (28 mg/kg) inhibited the increase in plasma cholesterol levels by about 20% and decreased the hepatic accumulation of free and esterified cholesterol by 61 and 67%, respectively. FY-087 also significantly inhibited the atherogenic diet-induced increase in the fatty-streak lesion area of the proximal aorta by 57% in C57BL/6J mice. These results indicate that FY-087 is not only a therapeutically bioavailable ACAT inhibitor that lowers plasma cholesterol levels, but also an effective anti-atherogenic agent in mice fed an atherogenic diet.

Asunto(s)

RESUMEN

To investigate the biological activity of the hopane group of pentacyclic triterpenes, the effect of bacteriohopane-32-old (Monol) on lipid synthesis and secretion was determined using Hep G2 cells. Despite its structural similarity to 25-hydroxycholesterol, Monol did not affect free and esterified cholesterol synthesis determined by the incorporation from [14C]acetate. Monol reduced the phospholipid secretion from Hep G2 cells without affecting cellular phospholipid synthesis from [3H]glycerol. It also decreased the secretion of apolipoprotein B. These results suggest that the Monol-induced reduction in phospholipid secretion is due to a decrease in the number of lipoprotein particles secreted from Hep G2 cells.

Asunto(s)

RESUMEN

To investigate the biological activities of the hopane group of pentacyclic triterpenoids, we isolated one hopanoid, bacteriohopane-32-ol from Rhodopseudomonas palustris and tested its cytotoxicity against mouse leukemia cells in vitro. The IC50 of the hopanoid for L1210 and P388 was 22 and 19 microM respectively. This activity was slightly reduced by co-incubation with cholesterol. As the mechanism of cytotoxic action, disturbances of membrane function and metabolism are discussed.

Asunto(s)

RESUMEN

A 28-year-old man with inoperable metastatic adenocarcinoma in the retroperitoneum was referred to our hospital for a further evaluation for its origin. The tumor was measured 80 x 107 mm by abd. U.S. and showed papillary adenocarcinoma, histologically. Chemotherapy with intravenous administration of CDDP at the dose of 80 mg/m2 for 6 times at 2-3 week intervals was started, and CDDP concentration of binding-form and free-form in serum and urine were measured in time course. The tumor has reduced for 29 weeks after the discontinuance of CDDP. Free-CDDP, which was thought to have an anticancerous effect, immediately went up high levels in serum and rapidly excreted to urine, while total-CDDP in serum remained in high concentration for more than 10 weeks. Thus it was suggested that anticancerous effect of CDDP could not be contributed only to free-CDDP and the mechanism of CDDP will be clarified by the elucidation of metabolism of both free and total CDDP, especially in the tumor tissue.

Asunto(s)

RESUMEN

Since the relationship between tissue ligandin and liver tumors has not been studied yet, we investigated the changes of Y protein and ligandin in human hepatoma and cholangioma by gel filtration, BSP-affinity chromatography, and SDS-gel electrophoresis. The concentration of Y protein was markedly increased in both hepatoma and cholangioma, 2.8 and 4.8 times that of control, respectively. The content of ligandin was also increased in both conditions. SDS polyacrylamide gel electrophoresis of the increased ligandin confirmed the increment of 2.3 K dalton protein, which coincided with the MW of the ligandin subunit. Although the mechanism of the ligandin increase in hepatoma tissue is not clear, one possible reason might be due to the degree of differentiation of the tumor cells. In our case, the pathological examination revealed that the tumor cell was classified as Edmondoson Type II.

Asunto(s)

Asunto(s)

Asunto(s)