Effect of oral sirolimus therapy on inflammatory biomarkers following coronary stenting

We studied the effect of oral sirolimus, administered to prevent and treat in-stent restenosis (ISR), on the variation of serum levels of inflammatory markers following coronary stenting with bare metal stents. The mean age of the patients was 56 ± 13 years, 65 percent were males and all had clinically manifested ischemia. Serum levels of high sensitivity C-reactive protein (hs-CRP) concentration were determined by chemiluminescence and serum levels of all other biomarkers by ELISA. One group of patients at high risk for ISR received a loading oral dose of 15 mg sirolimus and 5 mg daily thereafter for 28 days after stenting (SIR-G). A control group (CONT-G) was submitted to stenting without sirolimus therapy. The increase in hs-CRP concentration was highest at 24 h after stenting in both groups. A significant difference between SIR-G and CONT-G was observed at 4 weeks (-1.50 ± 5.0 vs -0.19 ± 0.4, P = 0.008) and lost significance 1 month after sirolimus discontinuation (-1.73 ± 4.3 vs -0.01 ± 0.7, P = 0.0975). A continuous fall in MMP-9 concentration was observed in SIR-G, with the greatest reduction at 4 weeks (-352.9 ± 455 vs +395.2 ± 377, P = 0.0004), while a positive variation was noted 4 weeks after sirolimus discontinuation (227 ± 708 vs 406.2 ± 472.1, P = 0.0958). SIR-G exhibited a higher increase in P-selectin after sirolimus discontinuation at week 8 (46.1 ± 67.9 vs 5.8 ± 23.7, P = 0.0025). These findings suggest that the anti-restenotic actions of systemic sirolimus include anti-proliferative effects and modulation of the inflammatory response with inhibition of adhesion molecule expression.

Gene expression profiling of clinical stages II and III breast cancer

Clinical stage (CS) is an established indicator of breast cancer outcome. In the present study, a cDNA microarray platform containing 692 genes was used to identify molecular differences between CSII and CSIII disease. Tumor samples were collected from patients with CSII or CSIII breast cancer, and normal breast tissue was collected from women without invasive cancer. Seventy-eight genes were deregulated in CSIII tumors and 22 in CSII tumors when compared to normal tissue, and 20 of them were differentially expressed in both CSII and CSIII tumors. In addition, 58 genes were specifically altered in CSIII and expression of 6 of them was tested by real time RT-PCR in another cohort of patients with CSII or CSIII breast cancer and in women without cancer. Among these genes, MAX, KRT15 and S100A14, but not APOBEC3G or KRT19, were differentially expressed on both CSIII and CSII tumors as compared to normal tissue. Increased HMOX1 levels were detected only in CSIII tumors and may represent a molecular marker of this stage. A clear difference in gene expression pattern occurs at the normal-to-cancer transition; however, most of the differentially expressed genes are deregulated in tumors of both CS (II and III) compared to normal breast tissue.

Mechanisms involved in calcium oxalate endocytosis by Madin-Darby canine kidney cells

Calcium oxalate (CaOx) crystals adhere to and are internalized by tubular renal cells and it seems that this interaction is related (positively or negatively) to the appearance of urinary calculi. The present study analyzes a series of mechanisms possibly involved in CaOx uptake by Madin-Darby canine kidney (MDCK) cells. CaOx crystals were added to MDCK cell cultures and endocytosis was evaluated by polarized light microscopy. This process was inhibited by an increase in intracellular calcium by means of ionomycin (100 nM; N = 6; 43.9 percent inhibition; P<0.001) or thapsigargin (1 µM; N = 6; 33.3 percent inhibition; P<0.005) administration, and via blockade of cytoskeleton assembly by the addition of colchicine (10 µM; N = 8; 46.1 percent inhibition; P<0.001) or cytochalasin B (10 µM; N = 8; 34.2 percent inhibition; P<0.001). Furthermore, CaOx uptake was reduced when the activity of protein kinase C was inhibited by staurosporine (10 nM; N = 6; 44 percent inhibition; P<0.01), or that of cyclo-oxygenase by indomethacin (3 µM; N = 12; 17.2 percent inhibition; P<0.05); however, the uptake was unaffected by modulation of potassium channel activity with glibenclamide (3 µM; N = 6), tetraethylammonium (1 mM; N = 6) or cromakalim (1 µM; N = 6). Taken together, these data indicate that the process of CaOx internalization by renal tubular cells is similar to the endocytosis reported for other systems. These findings may be relevant to cellular phenomena involved in early stages of the formation of renal stones

O papel das citocinas na disfunção ventricular avançada / The role of cytokines in advanced ventricualar dysfunction

A insuficiência cardíaca congestiva foi definida por muito tempo como uma síndrome envolvendo profundas alteraçöes hemodinâmicas e neuro-hormonais. Nos últimos anos, uma reação inflamatória exuberante tem sido observada na presença de disfunção ventricular sistólica severa, tanto em modelos experimentais como em ensaios clínicos. Essa resposta inflamatória envolve a ativaçäo e a liberaçäo de uma série de substâncias peptídicas denominadas citocinas. Essas substâncias parecem ter papel relevante tanto na gênese como na manutencçäo do processo de insuficiência ventricular, e podem ser utilizadas inclusive como marcadores prognósticos da doença. O presente artigo apresenta, de forma resumida, os principais estudos clínicos nessa área, destacando a correlaçäo entre determinadas citocinas e variáveis clínico-laboratoriais já descritas em portadores de insuficiência cardíaca congestiva avançada.