CCL2/Monocyte Chemoattractant Protein-1 regulates inflammatory responses critical to healing myocardial infarcts

The CC chemokine Monocyte Chemoattractant Protein (MCP)-1/CCL2 has potent mononuclear cell chemo-attractant properties, modulates fibroblast and endothelial cell phenotype and may play an important role in wound healing. In order to examine whether MCP-1 critically regulates myocardial infarct healing, we studied the effects of MCP-1 gene disruption and antibody neutralization in a closed-chest model of reperfused murine myocardial infarction. MCP-1-/- mice had decreased and delayed macrophage infiltration in the healing infarct and demonstrated delayed replacement of injured cardiomyocytes with granulation tissue. In contrast, the time course and density of neutrophil infiltration was similar in MCP-1 null and wild-type animals. MCP-1-/- infarcts had decreased mRNA expression of the cytokines TNF-alpha, IL-1beta, TGF-beta2, -beta3, and IL-10 and demonstrated defective macrophage differentiation evidenced by decreased Osteopontin-1 expression. MCP-1 deficiency diminished myofibroblast accumulation but did not significantly affect infarct angiogenesis. Despite showing delayed phagocytotic removal of dead cardiomyocytes, MCP-1-/- mice had attenuated left ventricular remodeling, but similar infarct size when compared with wild-type animals. MCP-1 antibody inhibition resulted in defects comparable with the pathological findings noted in infarcted MCP-1-/- animals without an effect on macrophage recruitment. MCP-1 has important effects on macrophage recruitment and activation, cytokine synthesis and myofibroblast accumulation in healing infarcts. Absence of MCP-1 results in attenuated post-infarction left ventricular remodeling, at the expense of a prolonged inflammatory phase and delayed replacement of injured cardiomyocytes with granulation tissue.     

Identification of a third evolutionarily conserved gene within the RAG locus and its RAG1-dependent and -independent regulation

Recombination-activating gene (RAG)1 and RAG2 encode T and B lymphocyte-specific endonucleases indispensable for rearrangements of antigen-receptor gene segments but also capable of causing deleterious chromosome rearrangements. The mechanisms regulating RAG expression and repression are not clear. Here we identify NWC, a third evolutionarily conserved gene within the RAG locus, and show that it is ubiquitously expressed, with the notable exception of RAG-nonexpressing immature and mature T and B lymphocytes because in lymphocytes it is regulated by the RAG1 promoter and transcribed as RAG1-NWC hybrid mRNA molecules. We also show that in all other cells NWC is controlled by the RAG2 intragenic promoter, which in immature and mature T and B lymphocytes is silent. The possible implications of these findings for understanding the activation and inactivation of RAG genes in lymphocytes and their repression in other cells are discussed.     

Detection of functional connectivity using temporal correlations in MR images

Functional connectivity among brain regions has been investigated via an analysis of correlations between regional signal fluctuations recorded in magnetic resonance (MR) images obtained in a steady state. In comparison with studies of functional connectivity that utilize task manipulations, the analysis of correlations in steady state data is less susceptible to confounds arising when functionally unrelated brain regions respond in similar ways to changes in task. A new approach to identifying interregional correlations in steady state data makes use of two independent data sets. Regions of interest (ROIs) are defined and hypotheses regarding their connectivity are generated in one data set. The connectivity hypotheses are then evaluated in the remaining (independent) data set by analyzing low frequency temporal correlations between regions. The roles of the two data sets are then reversed and the process repeated, perhaps multiple times. This method was illustrated by application to the language system. The existence of a functional connection between Broca's area and Wernicke's area was confirmed in healthy subjects at rest. An increase in this functional connection when the language system was actively engaged (when subjects were continuously listening to narrative text) was also confirmed. In a second iteration of analyses, a correlation between Broca's area and a region in left premotor cortex was found to be significant at rest and to increase during continuous listening. These findings suggest that the proposed methodology can reveal the presence and strength of functional connections in high-level cognitive systems.     

Antibacterial,antioxidant and anti-proliferative properties and zinc content of five south Portugal herbs

Context: Crataegus monogyna L. (Rosaceae) (CM), Equisetum telmateia L. (Equisataceae) (ET), Geranium purpureum Vil. (Geraniaceae) (GP), Mentha suaveolens Ehrh. (Lamiaceae) (MS), and Lavandula stoechas L. spp. luisieri (Lamiaceae) (LS) are all medicinal.

Objective: To evaluate the antioxidant, antiproliferative and antimicrobial activities of plant extracts and quantify individual phenolics and zinc.

Material and methods: Aerial part extracts were prepared with water (W), ethanol (E) and an 80% mixture (80EW). Antioxidant activity was measured with TAA, FRAP and RP methods. Phenolics were quantified with a HPLC. Zinc was quantified using voltammetry. Antibacterial activity (after 48?h) was tested using Enterococcus faecalis, Bacillus cereus, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Listeria monocytogenes. Antiproliferative activity (after 24?h) was tested using HEP G2 cells and fibroblasts.

Results: Solvents influenced results; the best were E and 80EW. GP had the highest antioxidant activity (TAA and FRAP of 536.90?mg AAE/g dw and 783.48?mg TE/g dw, respectively). CM had the highest zinc concentration (37.21?mg/kg) and phenolic variety, with neochlorogenic acid as the most abundant (92.91?mg/100?g dw). LS was rich in rosmarinic acid (301.71?mg/100?g dw). GP and LS inhibited the most microorganisms: B. cereus, E. coli and S. aureus. GP also inhibited E. faecalis. CM had the lowest MIC: 5830?μg/mL. The antibacterial activity is explained by the phenolics present. LS and CM showed the most significant anti-proliferative activity, which is explained by their zinc content.

Conclusion: The most promising plants for further studies are CM, LS and GP.     

The Effect of Hemodialysis on Left Ventricular Outflow Tract Gradient

Background: The aim of the study was to assess the effect of hemodialysis (HD) on left ventricular outflow tract gradient (LVOTG) measured both in supine and upright position (provocative maneuver to unload LV cavity by rapid preload reduction). Supine/standing echocardiography was performed immediately before and immediately after HD. For additional verification of the hypothesis about preload‐dependence of LVOTG, the echocardiograms after long (2‐day delay HD due to weekend) versus short (usual 1‐day) pause between HDs were compared. Methods: Forty‐one patients on chronic HD (mean age 44 ± 11 years) were examined using a portable hand‐carried echocardiograph. In accordance with the prestudy assumption the ultrafiltration volume was significantly greater during HD after a long pause in comparison to HD after a short pause (3707 ± 2826 mL vs. 2665 ± 1152 mL P < 0.05). Results: After a long pause, the mean value of LVOTG at the pre‐HD was mildly increased in the supine position and remained at a similar level in the upright position (13.1 ± 6.1 vs. 13.6 ± 9.1 mmHg). Mean LVOTG at the post‐HD in the supine position was similar to pre‐HD, however the orthostatic stress test induced a significant increase of LVOTG (13.9 ± 15.2 vs. 18.2 ± 19.9 mmHg P < 0.05). After a short pause at the pre‐HD the LVOTG in the supine position and after the orthostatic provocation was very similar to measurements after long pause (13.3 ± 9.1 vs. 13.3 ± 10.8 mmHg). At the post‐HD the mean value of LVOTG increased during upright posture but the differences were of borderline significance (13.2 ± 6.6 vs. 17.9 ± 18.6 mmHg P = 0.052). Conclusions: HD predisposed to standing‐provoked LVOTG especially when a long pause (2 days) between HDs induced a greater weight gain and subsequently a larger volume of ultrafiltration was needed to reduce hypervolemia. (Echocardiography 2010;27:603‐607)     

Serum concentrations of 17β-E2 and 25-hydroxycholecalciferol (25OHD) in relation to all-cause mortality in older men – the MINOS study

Objective To examine the association of serum hormone levels with all‐cause mortality in older community‐dwelling men. Design Single centre cohort study. Subjects Men aged 50 and older, insured by Société de Secours Minière de Bourgogne (Montceau les Mines, France). Among 3400 men invited to participate, 782 volunteers had serum hormone measurements and were followed up for 10 years. No exclusion criteria were used. Results Nonsurvivors (n = 182) were older, had more comorbidities and lower physical performance. The lowest quartile of 25‐hydroxycholecalciferol (25OHD) level predicted mortality [HR = 1·44, 95% confidence interval (CI): 1·03–2·03, P < 0·05] regardless of age, BMI, smoking, physical activity, vitamin D supplementation, and health status; mainly for the first 3 years. The 17β‐E₂ level predicted mortality independent of confounders after the third year (HR = 1·21 per 1 SD increase, 95% CI: 1·09–1·35, P < 0·001). In the fully adjusted models, risk of death increased per quartiles of 17β‐E₂ (trend –P < 0·001) and was higher in the third and the fourth quartiles compared with the lowest quartile (HR = 1·80, 95% CI: 1·09–2·98, P < 0·05 and HR = 2·83, 95% CI: 1·71–4·67, P < 0·001). Concentrations of testosterone and PTH did not predict mortality independent of the model. Conclusions In older men, increased 17β‐E₂ level predicted mortality after 3 years of follow‐up. Thus, high 17β‐E₂ level may reflect presence of risk factors precipitating development of diseases. Low 25OHD level predicted mortality more weakly, mainly for the first 3 years of the follow‐up, and was strongly influenced by the confounding variables. Thus, low 25OHD level may reflect poor current health status and unhealthy lifestyle.     

Ca2+ release-activated Ca2+ channel blockade as a potential tool in antipancreatitis therapy

Alcohol-related acute pancreatitis can be mediated by a combination of alcohol and fatty acids (fatty acid ethyl esters) and is initiated by a sustained elevation of the Ca²⁺ concentration inside pancreatic acinar cells ([Ca²⁺]_i), due to excessive release of Ca²⁺ stored inside the cells followed by Ca²⁺ entry from the interstitial fluid. The sustained [Ca²⁺]_i elevation activates intracellular digestive proenzymes resulting in necrosis and inflammation. We tested the hypothesis that pharmacological blockade of store-operated or Ca²⁺ release-activated Ca²⁺ channels (CRAC) would prevent sustained elevation of [Ca²⁺]_i and therefore protease activation and necrosis. In isolated mouse pancreatic acinar cells, CRAC channels were activated by blocking Ca²⁺ ATPase pumps in the endoplasmic reticulum with thapsigargin in the absence of external Ca²⁺. Ca²⁺ entry then occurred upon admission of Ca²⁺ to the extracellular solution. The CRAC channel blocker developed by GlaxoSmithKline, GSK-7975A, inhibited store-operated Ca²⁺ entry in a concentration-dependent manner within the range of 1 to 50 μM (IC₅₀ = 3.4 μM), but had little or no effect on the physiological Ca²⁺ spiking evoked by acetylcholine or cholecystokinin. Palmitoleic acid ethyl ester (100 μM), an important mediator of alcohol-related pancreatitis, evoked a sustained elevation of [Ca²⁺]_i, which was markedly reduced by CRAC blockade. Importantly, the palmitoleic acid ethyl ester-induced trypsin and protease activity as well as necrosis were almost abolished by blocking CRAC channels. There is currently no specific treatment of pancreatitis, but our data show that pharmacological CRAC blockade is highly effective against toxic [Ca²⁺]_i elevation, necrosis, and trypsin/protease activity and therefore has potential to effectively treat pancreatitis.