Francisco O’Valle

Acute Myocardial Infarct Size Is Related to Periodontitis Extent and Severity

Cardiovascular disease has been associated with 40% of deaths in high-income countries and 28% in lower-income countries. The relationship between periodontitis and acute myocardial infarction is well documented, but it has not been established whether the extent and severity of periodontitis influence the infarct size. This cross-sectional and analytic study was designed to investigate the association of chronic periodontitis extent and severity with acute myocardial infarct size as indicated by serum cardiac troponin I and myoglobin levels. Sociodemographic, periodontal, cardiologic, and hematologic variables were gathered in 112 consecutive patients with myocardial infarction. The extent (Arbes Index) and severity (Periodontal Inflammatory Severity Index) of the chronic periodontitis were significantly associated with troponin I levels after controlling for sociodemographic and clinical confounders (change in R2 = .041, p < .02, and R2 = .031, p = .04). However, only the extent index accounted for levels of myoglobin (change in R2 = .030, p < .05), total leukocytes (change in R2 = .041 p < .02), and neutrophils (change in R2 = .059, p < .01). Mediated regression analysis showed that leukocytes and neutrophils may underlie these observed relationships of chronic periodontitis with troponin I and myoglobin. To our knowledge, this study contributes the first research data demonstrating that the extent and severity of periodontitis is positively associated with acute myocardial infarct size as measured by serum troponin I and myoglobin levels.

Quercetin inhibits vascular superoxide production induced by endothelin-1: Role of NADPH oxidase, uncoupled eNOS and PKC

Chronic administration of the most abundant dietary flavonoid quercetin exerts antihypertensive effects and improves endothelial function. We have investigated the effects of quercetin and its methylated metabolite isorhamnetin (1-10microM) on endothelial dysfunction and superoxide (O(2*)(-)) production induced by endothelin-1 (ET-1, 10nM). ET-1 increased the contractile response induced by phenylephrine and reduced the relaxant responses to acetylcholine in phenylephrine contracted intact aorta, and these effects were prevented by co-incubation with quercetin, isorhamnetin or chelerythrine (protein kinase C (PKC) inhibitor). This endothelial dysfunction was also improved by superoxide dismutase (SOD), apocynin (NADPH oxidase inhibitor) and sepiapterin (tetrahydrobiopterin synthesis substrate). Furthermore, ET-1 increased intracellular O(2*)(-) production in all layers of the vessel, protein expression of NADPH oxidase subunit p47(phox) without affecting p22(phox) expression and lucigenin-enhanced chemiluminescence signal stimulated by calcium ionophore A23187. All these changes were prevented by both quercetin and isorhamnetin. Moreover, apocynin, endothelium denudation and N(G)-nitro-l-arginine methylester (l-NAME, nitric oxide synthase inhibitor) suppressed the ET-1-induced increase in A23187-stimulated O(2*)(-) generation. Moreover, quercetin but not isorhamnetin, inhibited the increased PKC activity induced by ET-1. Taken together these results indicate that ET-1-induced NADPH oxidase up-regulation and eNOS uncoupling via PKC leading to endothelial dysfunction and these effects were prevented by quercetin and isorhamnetin.

Wine Polyphenols Improve Endothelial Function in Large Vessels of Female Spontaneously Hypertensive Rats

Red wine polyphenols (RWPs) have been reported to prevent hypertension and endothelial dysfunction. Several individual RWPs exert estrogenic effects. We analyzed the possible in vivo protective effects on blood pressure and endothelial function of RWPs in female spontaneously hypertensive rats (SHR) and its relationship with ovarian function. RWPs (40 mg/kg by gavage) were orally administered for 5 weeks. Ovariectomized rats showed both increased isoprostaglandin F2&agr; excretion and aortic superoxide production and reduced relaxant response to acetylcholine and contraction to the endothelial nitric oxide synthase (eNOS) inhibitor l-NAME measured in the aorta but similar blood pressure, as compared with sham-operated rats. Moreover, in ovariectomized rats aortic eNOS expression was unchanged, whereas caveolin-1, angiotensin II receptor (AT)-1, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits p22phox and p47phox expression was increased compared with sham-operated rats. In both ovariectomized and sham-operated SHR, RWPs reduced systolic blood pressure, urinary isoprostaglandin F2&agr; excretion, and aortic O2− production, improving the endothelium-dependent relaxant response to acetylcholine in SHR. These changes were associated with unchanged aortic eNOS expression, whereas caveolin-1 was increased and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits p22phox and p47phox expression was reduced. RWPs had no effect on the AT-1 overexpression found in ovariectomized animals. All these results suggest that a chronic treatment with RWPs reduces hypertension and vascular dysfunction through reduction in vascular oxidative stress in female SHR in a manner independent of the ovarian function.

Anticonvulsant-induced toxic epidermal necrolysis: Monitoring the immunologic response

BACKGROUND Toxic epidermal necrolysis is a severe reaction with skin involvement induced by different drugs and other agents. The mechanisms implicated in the induction of the reaction are poorly understood. OBJECTIVE Our purpose was to study the involvement of T lymphocytes and other immunocompetent cells in the peripheral blood, blister fluid, and affected skin of 3 patients who had a severe reaction after receiving anticonvulsant medication. METHODS Quantification of T lymphocytes expressing the skin-homing receptor (cutaneous lymphocyte-associated antigen ¿CLA) in peripheral blood, skin, and skin blister fluid and assessment of other adhesion molecules, activation markers, and inflammatory interleukins by flow cytometry, immunohistochemistry, and reverse transcription-PCR. RESULTS An increase in CD3(+)CLA(+) cells paralleling the severity of the disease was observed in both peripheral blood and skin, tending to normalize as soon as patients conditions improved. E-selectin was detected in endothelial vessels in parallel with CLA expression on lymphocytes. An overexpression of TNFalpha, IFN-gamma, and IL-2 was also observed in PBMCs. The expression of the different markers changed over the course of the disease. CONCLUSIONS These data show an increase in activated T cells expressing the skin-homing receptor in both tissue and peripheral blood accompanying clinical symptoms, with a recruitment of macrophages and an overexpression of cytokines. All these results suggest an important role for T cells in the production of toxic epidermal necrolysis.

Altered Drug Membrane Permeability in a Multidrug- Resistant Leishmania tropica Line

We selected a Leishmania tropica cell line resistant to daunomycin (DNM) that presents a multidrug-resistant (MDR) phenotype characterized by overexpression of a P-glycoprotein of 150 kDa. The resistant line overexpressed an MDR-like gene, called ltrmdr1, located in an extrachromosomal circular DNA. DNM uptake experiments using laser flow cytometry showed a significant reduction in drug accumulation in the resistant parasites. The initial stages of the interaction of DNM with membranes from wild-type and DNM-resistant parasites were defined by a rapid kinetic stopped-flow procedure which can be described by two kinetic components. On the basis of a previous similar kinetic study with tumor cells, we ascribed the fast component to rapid interaction of DNM with membrane surface components and the slow component to passive diffusion of the drug across the membranes. The results reported here indicate that entrance of DNM into wild-type parasites was facilitated in respect to the resistant ones. We propose that resistance to DNM in L. tropica is a multifactorial event involving at least two complementary mechanisms. an altered drug membrane permeability and the overexpression of a protein related to P-glycoprotein that regulates drug efflux.

Role of wettability and nanoroughness on interactions between osteoblast and modified silicon surfaces.

Development of new biomaterials is a constant in regenerative medicine. A biomaterials surface properties, such as wettability, roughness, surface energy, surface charge, chemical functionalities and composition, are determinants of cell adhesion and subsequent tissue behavior. Thus, the main aim of this study was to analyze the correlation between changes in wettability without topographical variation and the response of osteoblast-like cells. For this purpose oxidized silicon surfaces were methylated to different degrees. Additionally, the influence of nanoroughness, and the subsequent effect of hysteresis on cell behavior, was also analyzed. In this case oxidized silicon pieces were etched with caustic solutions to produce different degrees of nanoroughness. Axisymmetric drop-shape analysis and atomic force microscopy confirmed that the proposed surface treatments increased the nanometer roughness and/or the water contact angles. MG-63 osteoblast-like cells were cultured on the altered surfaces to study proliferation, and for ultrastructural analysis and immunocytochemical characterization. Increasing the nanometer surface roughness or water contact angle enhanced osteoblast behavior in terms of cell morphology, proliferation and immunophenotype, the effect provoked by methylation being more significant than that caused by nanoroughness.

The endemic flora in the south of the Iberian Peninsula: taxonomic composition, biological spectrum, pollination, reproductive mode and dispersal

Summary The taxonomical composition and four ecological characteristics (life form, seed-dispersal, pollination and reproductive mode) of the 553 endemic species occurring in the south of the Iberian Peninsula have been investigated. A comparative analysis of the results reveals that this endemic flora does not comply with the general patterns previously observed in local floras, Mediterranean regional floras and floras of temperate latitudes. Predominant life forms are chamaephytes (45%) and hemicryptophytes (33%). By contrast, therophytes (11%) and phanerophytes (1%) are relatively infrequent. This spectrum of life forms mirrors the altitudinal distribution of the endemic species, their seed-dispersal strategy and the type of phytocoenoses in which they occur. As far seed-dispersal is concerned, 44% of the endemic species lack any noteworthy adaptive feature. However, the results clearly suggest that this limitation in their disseminative potential has only encouraged endemicity among the therophytes inhabiting lowlands. Among chamaephytes and hemicryptophytes of medium and high altitude, there is a relatively high frequency of exozoochory and anemochory, an adaptation that has contributed to the survival of small plant populations. 91% of the endemic species are pollinated by animals (insects), and only 3 species are dioecious. The dichotomies that the above mentioned characteristics produce (herbaceous vs woody life form, animal-assisted vs abiotic seed-dispersal, animal-assisted vs abiotic pollination and dioecious vs hermaphrodite reproductive mode), have been used to plot statistically significant associations. These are three: Pollination mode is linked with the seed-dispersal strategy, life form with pollination mode, and pollination mode with the reproductive mode. These associations contrast distinctly with results of previous surveys on whole floras, a contrast which makes the singularity of the endemic flora of the Southern Iberian peninsula even more remarkable.

P Glycoprotein: A New Mechanism to Control Drug-Induced Nephrotoxicity

The role of P glycoprotein (P-gp) in kidney is now being explored, and under physiological conditions, this protein is thought to be an excretory pump of cationic xenobiotics and metabolites. Functionally, two different types of P-gp have been described, but only the class I has been related to drug transport, and its overexpression confers the multidrug resistance phenotype in tumoral cells. It has been proposed that P-gp is involved in the energy-dependent transport of substrates through the cell membrane (toxic metabolites, toxins, nutrients, ions, peptides, etc.) – like a ‘hydrophobic molecule vacuum cleaner’. Several physiological functions have been attributed to P-gp: defense against xenobiotic aggression and transmembrane transport of prenylcysteine methyl esters, removing these cytotoxic metabolites from cells. A variety of substrates ranging from chemotherapeutics to steroid hormones, antibiotics, and calcium channel blockers can be transported by P-gp, suggesting the possible involvement of this protein in other unknown functions. Results from our group and others have suggested that overexpression of P-gp in renal tubular and mesangial cells prevents pharmacological nephrotoxicity by cyclosporin A (CsA). On the other hand CsA, a substrate of the pump, could act as a blocker in tubular cells by competitive inhibition. One relevant aspect in kidney is the possible relationship between P-gp and protein kinase C. Several reports suggest that protein kinase C may play a role in inducing the P-gp overexpression in cells under xenobiotic pressure, through activation of the ras oncoprotein family. This could be mediated directly by angiotensin II as a ras activator. This way, the detoxicant function of P-gp against products of the ras catabolism could mediate their accumulation when the ‘vacuum cleaner’ function is blocked by CsA or tacrolimus, contributing to the initial development of fibroblastic activation that leads to interstitial fibrosis associated with nephrotoxicity by these immunosuppressor drugs. In conclusion, P-gp expression could be an important component of a complex detoxifying system in kidney against xenobiotics or regulating the traffic of endogenous metabolites responsible for the susceptibility of subjects to the development of nephrotoxicity against different drugs.

Marginal bone loss as success criterion in implant dentistry: beyond 2 mm.

AIM The aim of this study was to analyze marginal bone loss (MBL) rates around implants to establish the difference between physiological bone loss and bone loss due to peri-implantitis. MATERIALS AND METHODS Five hundred and eight implants were placed in the posterior maxilla in 208 patients. Data were gathered on age, gender, bone substratum (grafted or pristine), prosthetic connection, smoking and alcohol habits, and previous periodontitis. MBL was radiographically analyzed in three time frames (5 months post-surgery and at 6 and 18 months post-loading). Nonparametric receiver operating curve (ROC) analysis and mixed linear model analysis were used to determine whether implants could be classified as high or low bone loser type (BLT) and to establish the influence of this factor on MBL rates. RESULTS Marginal bone loss rates were significantly affected by BLT, connection type, bone substratum, and smoking. Bone loss rates at 18 months were associated with initial bone loss rates: 96% of implants with an MBL of >2 mm at 18 months had lost 0.44 mm or more at 6 months post-loading. CONCLUSION Implants with increased MBL rates at early stages (healing and immediate post-loading periods) are likely to reach MBL values that compromise their final outcome. Initial (healing, immediate post-loading) MBL rates around an implant of more than 0.44 mm/year are an indication of peri-implant bone loss progression.

Human umbilical cord stromal stem cell express CD10 and exert contractile properties

BACKGROUND It has been demonstrated that human umbilical cord stromal stem cells (UCSSCs) are bio-equivalent to bone marrow mesenchymal stem cells. However, little is known about their tissue origin or in vivo functions, and data on their expansion properties are limited due to early senescence in the culture methods described to date. METHODS UC sections and cultured UCSSCs were analyzed with a panel of 12 antibodies. UCSSCs were grown in low-FCS containing medium at 5% or 21% oxygen and were assayed for their clonogenic properties, karyotype stability, expression of specific cellular markers, and multi-lineage potential. UCSSC contractile properties were evaluated by using collagen gel contraction assays under cytokine stimulus. RESULTS Immunohistochemistry studies showed that the UCSSCs were derived from the Whartons jelly and not from the vascular smooth muscle sheath of the blood vessels. UCSSC growth properties were increased in a 5% oxygen atmosphere in comparison to normoxic culture conditions. In both culture conditions, UCSSCs were CD14-, CD34-, and CD45-negative while expressing high levels of CD73, CD90 and CD105 and maintaining their differentiation potentialities. UCSSCs expressed alpha smooth muscle actin and behaved as functional myofibroblasts when cellular contraction was challenged with appropriate stimuli. CONCLUSIONS UCSCs are mesenchymal stem cells that reside in the perivascular area of Whartons jelly and are phenotypically and functionally related to myofibroblasts.