Resting-state EEG signatures of Alzheimer's disease are driven by periodic but not aperiodic changes.

Electroencephalography (EEG) has shown potential for identifying early-stage biomarkers of neurocognitive dysfunction associated with dementia due to Alzheimer's disease (AD). A large body of evidence shows that, compared to healthy controls (HC), AD is associated with power increases in lower EEG frequencies (delta and theta) and decreases in higher frequencies (alpha and beta), together with slowing of the peak alpha frequency. However, the pathophysiological processes underlying these changes remain unclear. For instance, recent studies have shown that apparent shifts in EEG power from high to low frequencies can be driven either by frequency specific periodic power changes or rather by non-oscillatory (aperiodic) changes in the underlying 1/f slope of the power spectrum. Hence, to clarify the mechanism(s) underlying the EEG alterations associated with AD, it is necessary to account for both periodic and aperiodic characteristics of the EEG signal. Across two independent datasets, we examined whether resting-state EEG changes linked to AD reflect true oscillatory (periodic) changes, changes in the aperiodic (non-oscillatory) signal, or a combination of both. We found strong evidence that the alterations are purely periodic in nature, with decreases in oscillatory power at alpha and beta frequencies (AD < HC) leading to lower (alpha + beta) / (delta + theta) power ratios in AD. Aperiodic EEG features did not differ between AD and HC. By replicating the findings in two cohorts, we provide robust evidence for purely oscillatory pathophysiology in AD and against aperiodic EEG changes. We therefore clarify the alterations underlying the neural dynamics in AD and emphasize the robustness of oscillatory AD signatures, which may further be used as potential prognostic or interventional targets in future clinical investigations.

Promotion of physical activity after hospitalization for COPD exacerbation: A randomized control trial.

BACKGROUND AND OBJECTIVE: Physical activity worsens during exacerbations of chronic obstructive pulmonary disease (COPD) and notably after hospitalizations. Pedometer-based interventions are useful to increase physical activity in stable patients with COPD. However, there is little information concerning the implementation of such programs following severe exacerbation. This study assessed the efficacy of a physical activity program after hospitalization for a COPD exacerbation. METHODS: We performed a prospective, 12-week, parallel group, assessor-blinded, randomized control trial in COPD patients hospitalized for an exacerbation. After discharge, physical activity and other secondary variables were assessed. Patients were allocated (1:1) to a physical activity promotion program (intervention group, IG) or usual care (control group, CG). Based on a motivational interview and accelerometer physical activity assessment, a patient-tailored, pedometer-based, progressive and target-driven program was designed. Linear mixed effect models were used to analyse between-group differences. RESULTS: Forty-six out of 61 patients recruited were randomized and 43 (IG = 20, CG = 23) completed the study. In-hospital and baseline characteristics were similar in both groups. After 12 weeks of intervention, the mean steps difference between groups was 2093 steps/day, p = 0.018, 95% CI 376-4012, favouring the IG. Only the IG significantly increased the number of steps/day compared to baseline (mean difference [95% CI] 2932 [1069-4795] steps; p = 0.004). There were no other between-group differences. CONCLUSION: After hospitalization for a COPD exacerbation, a patient-tailored physical activity program based on a motivational interview and the use of pedometers, with progressive and customized targets, improved the number of steps/day.

Effectiveness of physical therapy interventions in women with dyspareunia: a systematic review and meta-analysis.

BACKGROUND: Dyspareunia is defined as the occurrence of pain during or after sexual intercourse, which directly affects physical, sexual, and mental health. This condition can lead to depression, anxiety, and low self-esteem in women who experience it. OBJECTIVES: The aim of this research was to evaluate the effectiveness of physical therapy interventions for the treatment of female dyspareunia. DESIGN: A systematic review and meta-analysis was conducted. METHOD: Search of publications was conducted in Scopus, Medline, Pubmed, Cinahl and Web of Science. Treatment effects were defined as standardized mean difference and their 95% confidence intervals. Statistical heterogeneity was assessed using Crohan's Q test and quantified using the I2 index. RESULTS: Of the 19 articles selected, six applied multimodal physiotherapy treatments; five, electrotherapy; three, Thiele's massage; two, interdisciplinary interventions or pelvic floor muscle training; and one, extracorporeal shockwave therapy. The meta-analysis showed significant results for the variables pain and quality of life with the interventions based on electrotherapy and electrotherapy combined with pelvic floor muscle training. These interventions did not show significant results for the improvement of sexual function. CONCLUSIONS: Physiotherapy techniques are effective and procedures have been identified with reliable results in improving pain and quality of life in patients with dyspareunia. One of the most important aspects is the strengthening of the perineal musculature and the application of Transcutaneous Electrical Nerve Stimulation. Furthermore, manual trigger point release therapy and Thiele massage, optimize and guarantee the reduction of pain intensity. PROSPERO REGISTRATION: CRD42021236155.

Specific Cationic Antimicrobial Peptides Enhance the Recovery of Low-Load Quiescent Mycobacterium tuberculosis in Routine Diagnostics.

The culture confirmation of Mycobacterium tuberculosis (MTB) remains the gold standard for the diagnosis of Tuberculosis (TB) with culture conversion representing proof of cure. However, over 40% of TB samples fail to isolate MTB even though many patients remain infectious due to the presence of viable non-culturable forms. Previously, we have shown that two short cationic peptides, T14D and TB08L, induce a hormetic response at low concentrations, leading to a stimulation of growth in MTB and the related animal pathogen Mycobacterium bovis (bTB). Here, we examine these peptides showing they can influence the mycobacterial membrane integrity and function through membrane potential reduction. We also show this disruption is associated with an abnormal reduction in transcriptomic signalling from specific mycobacterial membrane sensors that normally monitor the immediate cellular environment and maintain the non-growing phenotype. We observe that exposing MTB or bTB to these peptides at optimal concentrations rapidly represses signalling mechanisms maintaining dormancy phenotypes, which leads to the promotion of aerobic metabolism and conversion into a replicative phenotype. We further show a practical application of these peptides as reagents able to enhance conventional routine culture methods by stimulating mycobacterial growth. We evaluated the ability of a peptide-supplemented sample preparation and culture protocol to isolate the MTB against a gold standard routine method tested in parallel on 255 samples from 155 patients with suspected TB. The peptide enhancement increased the sample positivity rate by 46% and decreased the average time to sample positivity of respiratory/faecal sampling by seven days. The most significant improvements in isolation rates were from sputum smear-negative low-load samples and faeces. The peptide enhancement increased sampling test sensitivity by 19%, recovery in samples from patients with a previously culture-confirmed TB by 20%, and those empirically treated for TB by 21%. We conclude that sample decontamination and culture enhancement with D-enantiomer peptides offer good potential for the much-needed improvement of the culture confirmation of TB.

Hepatodamianol as hepatoprotective constituent of Turnera diffusa.

It is well known that liver diseases are a major health problem and that there is a lack of hepatoprotective agents. Turnera diffusa (damiana) is a plant with a widespread distribution in México, which has many traditional uses, including the treatment of hepatic illnesses. Based on the bioassay-guided fractionation of a methanolic extract obtained from the aerial part of T. diffusa, we purified and identified a compound called hepatodamianol (1). This C-glycoside exhibited a four times greater hepatoprotective effect than the widely used hepatoprotective agent silibinin against carbon tetrachloride damage in an in vitro model using HepG2 cells. Hepatodamianol produced no cytotoxic effects and it exhibited a high antioxidant capacity. Therefore, hepatodamianol is a good candidate compound for testing as a hepatoprotective agent in a preclinical trial.

Evaluation of hypoglycemic and antioxidant effects of Brickellia eupatorioides, Citrus limettioides and Gochnatia hypoleuca.

Diabetes is a chronic metabolic condition with a rapidly increasing prevalence. It comes with a rise in the generation of free radicals, potentially leading to additional health issues. Further studies and creative approaches are required to address this. Natural products are potential new antidiabetic drugs that are worth exploring. The aim of the present study is to assess the antihyperglycemic and antioxidant effects of ethanolic extracts of Brickellia eupatorioides, Citrus limettioides and Gochnatia hypoleuca. The antihyperglycemic activity of the extracts was tested on Wistar rats (diabetes induced by alloxan, 150mg/kg), as well as the inhibitory effect on a-glucosidase and a-amylase (in vitro assay). The antioxidant potential was evaluated using DPPH and ABTS assays. The total phenolic and flavonoid contents were also determined. The results indicated that ethanolic extracts of B. eupatorioides induced a powerful hypoglycemic in vivo effect with a significant decrease at 6h after administration, similar to that produced by glibenclamide; the decrease could be related to a-glucosidase inhibition. Moreover, the extract exhibited a potent scavenging activity (IC50 values 33±6mg/mL and 15±2mg/mL in the DPPH and ABTS methods, respectively). The results demonstrated antihyperglycemic and antioxidant activity of ethanolic extracts of B. eupatorioides.

Two-Step Competitive Hybridization Assay: A Method for Analyzing Cancer-Related microRNA Embedded in Extracellular Vesicles.

With an increased understanding of the role of microRNAs (miRNAs) in cancer evolution, there is a growing interest in the use of these non-coding nucleic acids in cancer diagnosis, prognosis, and treatment monitoring. miRNAs embedded in extracellular vesicles (EVs) are of particular interest given that circulating EVs carry cargo that are strongly correlated to their cells of origin such as tumor cells while protecting them from degradation. As such, there is a tremendous interest in new simple-to-operate vesicular microRNA analysis tools for widespread use in performing liquid biopsies. Herein, we present a two-step competitive hybridization assay that is rationally designed to translate low microRNA concentrations to large electrochemical signals as the measured signal is inversely proportional to the microRNA concentration. Using this assay, with a limit-of-detection of 122 aM, we successfully analyzed vesicular miRNA 200b from prostate cancer cell lines and human urine samples, demonstrating the expected lower expression levels of miRNA 200b in the EVs from prostate cancer cells and in the prostate cancer patient's urine samples compared to healthy patients and non-tumorigenic cell lines, validating the suitability of our approach for clinical analysis.

Prevalence of hepatitis E virus in children from Northeast of Argentina.

The aim of this study was to assess the prevalence of hepatitis E virus (HEV) in a young population from the Northeast region of Argentina. Four hundred and twelve patients under 18 years old, from rural areas of Chaco Province, were tested for anti-HEV immunoglobulin G (IgG) using enzyme-linked immunosorbent assay. Anti-HEV IgG antibodies were detected in 7 out of 412 patients, accounting for an overall 1.7% prevalence. HEV infection in developing countries is associated to lack of clean drinking water. Consequently, the seroprevalence observed in children in rural areas of Chaco, Argentina, where the access to tap water is less than 15%, was unexpectedly low.

Turnera diffusa extract attenuates profibrotic, extracellular matrix and mitochondrial markers in activated human hepatic stellate cells (HSC).

INTRODUCTION AND OBJECTIVES: Hepatic fibrosis is characterized by the accumulation of extracellular matrix which includes the accumulation of α-smooth muscle actin (α-SMA), collagen type I (COL1α1), as well as remodeling induced by metalloproteinases and tissue inhibitor of metalloproteinase (TIMPs), where hepatic stellate cells (HSCs) play a central role. In addition, the transcription factor SNAI1 (which participates in epithelial-mesenchymal transition, EMT) and mitofusin 2 (MFN2, a mitochondrial marker) plays an important role in chronic liver disease. Turnera diffusa (TD), a Mexican endemic plant, has been shown to possess antioxidant and hepatoprotective activity in vitro. We treated human HSC (LX2 cells) with a methanolic extract of Turnera diffusa (METD) to evaluate the mechanism involved in its hepatoprotective effect measured as fibrosis modulation, EMT, and mitochondrial markers. MATERIALS AND METHODS: HSC LX-2 cells were treated with METD (100 and 200ng/mL) alone or combined with TGF-ß (10ng/mL) at different time points (24, 48, and 72h). α-SMA, COL1α1, MMP2, TIMP1, SNAI1, and MFN2 mRNAs and protein levels were determined by real-time quantitative PCR and Western Blot analysis. RESULTS: We found that METD decreases COL1α1-mRNA, α-SMA, and TIMP1 protein expression in LX2 cells treated with and TGF-ß. This treatment also decreases MFN2 and TIMP1 protein expression and induces overexpression of MMP2-mRNA. CONCLUSIONS: Our results suggest that a methanolic extract of Turnera diffusa is associated with an antifibrotic effect by decreasing profibrotic and mitochondrial markers together with the possible induction of apoptosis through SNAI1 expression in activated HSC cells.

Glutaminolysis is a metabolic dependency in FLT3ITD acute myeloid leukemia unmasked by FLT3 tyrosine kinase inhibition.

FLT3 internal tandem duplication (FLT3ITD) mutations are common in acute myeloid leukemia (AML) associated with poor patient prognosis. Although new-generation FLT3 tyrosine kinase inhibitors (TKI) have shown promising results, the outcome of FLT3ITD AML patients remains poor and demands the identification of novel, specific, and validated therapeutic targets for this highly aggressive AML subtype. Utilizing an unbiased genome-wide clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 screen, we identify GLS, the first enzyme in glutamine metabolism, as synthetically lethal with FLT3-TKI treatment. Using complementary metabolomic and gene-expression analysis, we demonstrate that glutamine metabolism, through its ability to support both mitochondrial function and cellular redox metabolism, becomes a metabolic dependency of FLT3ITD AML, specifically unmasked by FLT3-TKI treatment. We extend these findings to AML subtypes driven by other tyrosine kinase (TK) activating mutations and validate the role of GLS as a clinically actionable therapeutic target in both primary AML and in vivo models. Our work highlights the role of metabolic adaptations as a resistance mechanism to several TKI and suggests glutaminolysis as a therapeutically targetable vulnerability when combined with specific TKI in FLT3ITD and other TK activating mutation-driven leukemias.

Molecular epidemiology of hepatitis B virus mutants associated with vaccine escape, drug resistance and diagnosis failure.

The massive implementation of the vaccine and antiviral agents against hepatitis B virus (HBV), targeting the envelope and viral polymerase genes, induces a selection pressure that might lead to the emergence of variants that impair the effectiveness of the vaccine, diagnostic methods and antiviral therapy. The aim of this study was to evaluate the prevalence of HBV vaccine escape mutants (VEMs), diagnostic failure mutants (DFMs) and treatment resistance mutants (ARMs) among individuals from Buenos Aires, Argentina. HBV surface antigen and polymerase sequences obtained from serum samples of 530 HBV-infected individuals were analysed. Samples belonged to genotypes A (28.1%), D (13.6%) and F (58.3%). VEMs, DMFs and ARMs were present in 40 (7.5%), 57 (10.7%) and 27 (5.1%) samples within the studied population. Additionally, eight nonpreviously reported VEMs and nine DFMs were identified. VEMs and DFMs were biased by genotype, being higher in genotype D (33.3% and 33.3%) compared to genotype A (6% and 17.4%) and genotype F (2.3% and 2.3%) (P > 0.001). On the contrary, there was no association between the presence of ARMs and HBV genotype (P = 0.324). VEMs, DFMs and ARMs create public health concerns. The current study provided valuable information about mutants in surface antigen and polymerase in HBV-infected patients from Argentina where HBV-F is the most prevalent genotype. Consequently, it constitutes an important reference for Latin American clinicians in order to optimize the management of HBV-infected patients.

Hepatitis C virus genotype 1 infection: Prevalence of NS5A and NS5B resistance-associated substitutions in naïve patients from Argentina.

Direct acting antiviral (DAA) therapy against hepatitis C virus (HCV) increases sustained virologic response rates. Nevertheless, drug resistance has occasionally been associated with failure to DAA. However, the information about the prevalence of NS5A and NS5B resistance-associated substitutions (RASs) in Argentina is very scarce. In this study, we determine the prevalence of NS5A and NS5B resistances to treatment in Argentinean DAA treatment-naïve patients chronically infected with genotype 1 (HCV-1). In this retrospective cross-sectional study, 108 HCV-1-infected patients were studied. RASs in NS5A and NS5B were analyzed by Sanger at baseline and phylogenetic analysis was performed. NS5A and NS5B RASs were detected in 25.8% and 6.3% of the analyzed sequences, respectively. The most frequent primary RASs for NS5A were L31M (7.5%) and Y93H (3.2%) and for NS5B was L159F (3.8%). No association between the presence of RASs and the outcome of DAA treatment was found in this study. Additionally, most of the Argentinean samples were randomly distributed among sequences around the world in the phylogenetic analysis. Only one significant Argentinean cluster was observed in both regions but without any particular RASs pattern. Baseline RASs in NS5A and NS5B were frequently observed in HCV-1-infected patients from Buenos Aires, Argentina but not related to treatment outcome. No clusters related to RASs transmission were observed in the phylogenetic analysis. The frequency of RASs detected in this study supports the need for more molecular epidemiology studies on RASs to adjust local treatment guidelines with the incorporation of autochthonous data.

Advantages of adipose tissue stem cells over CD34+ mobilization to decrease hepatic fibrosis in Wistar rats.

INTRODUCTION AND OBJECTIVES: Chronic liver inflammation may lead to hepatic cirrhosis, limiting its regenerative capacity. The clinical standard of care is transplantation, although stem cell therapy may be an alternative option. The study aim was to induce endogenous hematopoietic stem cells (HSCs) with granulocyte colony stimulating factor (G-CSF) and/or intravenous administration of adipose tissue-derived mesenchymal stem cells (MSCs) to decrease hepatic fibrosis in an experimental model. MATERIAL AND METHODS: A liver fibrosis model was developed with female Wistar rats via multiple intraperitoneal doses of carbon tetrachloride. Three rats were selected to confirm cirrhosis, and the rest were set into experimental groups to evaluate single and combined therapies of G-CSF-stimulated HSC mobilization and intravenous MSC administration. RESULTS: Treatment with MSCs and G-CSF significantly improved alanine amino transferase levels, while treatment with G-CSF, MSCs, and G-CSF+MSCs decreased aspartate amino transferase levels. Hepatocyte growth factor (HGF) and interleukin 10 levels increased with MSC treatment. Transforming growth factor ß levels were lower with MSC treatment. Interleukin 1ß and tumor necrosis factor alpha levels decreased in all treated groups. Histopathology showed that MSCs and G-CSF reduced liver fibrosis from F4 to F2. CONCLUSIONS: MSC treatment improves liver function, decreases hepatic fibrosis, and plays an anti-inflammatory role; it promotes HGF levels and increased proliferating cell nuclear antigen when followed by MSC treatment mobilization using G-CSF. When these therapies were combined, however, fibrosis improvement was less evident.

Anti-inflammatory and nephroprotective activity of Juglans mollis against renal ischemia-reperfusion damage in a Wistar rat model.

BACKGROUND: Oxidative stress and the inflammatory process are involved in ischemia-reperfusion (I/R) injury. Juglans mollis has been reported as having antioxidant activity, which could attenuate the damage caused by I/R. We evaluated whether a methanolic extract of Juglans mollis (JM) exhibits nephroprotective activity in a Wistar rat model of I/R injury. METHODS: Four groups of six rats were used: Sham, I/R, JM, and JM + I/R. Two groups were dosed with JM (300 mg/kg) for 7 days before I/R. I/R injury was induced by clamping the renal hilums for 45 min and then reperfusing the kidneys for 15 h. Blood samples were taken to evaluate the levels of alanine aminotransferase (ALT), blood urea nitrogen, creatinine, superoxide dismutase (SOD), malondialdehyde (MDA), interleukin 1ß (IL-1ß), IL-6, and tumor necrosis factor α (TNF-α). RESULTS: The levels of creatinine, ALT, MDA, IL-1ß, IL-6, and TNF-α were lower in JM + I/R than in I/R rats, whereas SOD level only was higher in JM + I/R than in Sham rats. No biochemical or histological damage was observed in JM rats compared with Sham rats; however, less histological damage was observed in JM + I/R rats compared with I/R rats. CONCLUSIONS: To our knowledge, this is the first report of nephroprotective activity of J. mollis against damage induced by I/R. This activity may be related to decreased levels of proinflammatory cytokines (IL-1ß, IL-6, and TNF-α) and modulation of oxidative stress markers (SOD and MDA) observed in the present study.

Stabilization of Polymeric Nanofibers Layers for Use as Real-Time and In-Flow Photonic Sensors.

In order to increase the sensitivity of a sensor, the relationship between its volume and the surface available to be functionalized is of great importance. Accordingly, porous materials are becoming very relevant, because they have a notable surface-to-volume ratio. Moreover, they offer the possibility to infiltrate the target substances on them. Among other porous structures, polymeric nanofibers (NFs) layers fabricated by electrospinning have emerged as a very promising alternative to low-cost and easy-to-produce high-performance photonic sensors. However, experimental results show a spectrum drift when performing sensing measurements in real-time. That drift is responsible for a significant error when trying to determine the refractive index variation for a target solution, and, because of that, for the detection of the presence of certain analytes. In order to avoid that problem, different chemical and thermal treatments were studied. The best results were obtained for thermal steps at 190 °C during times between 3 and 5 h. As a result, spectrum drifts lower than 5 pm/min and sensitivities of 518 nm/refractive index unit (RIU) in the visible range of the spectrum were achieved in different electrospun NFs sensors.

External Ca2+ regulates polycystin-2 (TRPP2) cation currents in LLC-PK1 renal epithelial cells.

Polycystin-2 (PC2, TRPP2) is a nonselective cation channel whose dysfunction is associated with the onset of autosomal dominant polycystic kidney disease (ADPKD). PC2 contributes to Ca2+ transport and cell signaling in renal epithelia and other tissues. Little is known however, as to the external Ca2+ regulation of PC2 channel function. In this study, we explored the effect of external Ca2+ on endogenous PC2 in wild type LLC-PK1 renal epithelial cells. We obtained whole cell currents at different external Ca2+ concentrations, and observed that the basal whole cell conductance in normal Ca2+(1.2mM), decreased by 30.2% in zero (nominal) Ca2+ and conversely, increased by 38% in high external Ca2+(6.2mM). The high Ca2+-increased whole cell currents were completely inhibited by either PC2 gene silencing, or intracellular dialysis with active, but not denatured by boiling, PC2 antibody. Exposure of cells to high Ca2+ was also associated with relocation of PC2 to the plasma membrane. To explore whether a Ca2+ sensing receptor (CaSR) was implicated in the external Ca2+ modulation of PC2 currents, we tested the effect of the CaSR agonists, spermine and the calcimimetic R-568, which largely mimicked the effect of high Ca2+ under Ca2+-free conditions. The CaSR agonist gentamicin also increased the PC2 currents in the presence of normal Ca2+. The presence of CaSR was confirmed by immunocytochemistry, which partially colocalized with the intracellular PC2 protein, in an external Ca2+-dependent manner. The data support a novel Ca2+ sensing mechanism for PC2 expression and functional regulation in renal epithelial cells.

Compartmentalization of hepatitis C virus variants in patients with hepatocellular carcinoma.

Chronic Hepatitis C Virus (HCV) infection is a major risk for hepatocellular carcinoma (HCC) development. HCV Core protein has been associated with the modulation of potentially oncogenic cellular processes and E2 protein has been useful in evolutive studies to analyze the diversity of HCV. Thus, the aim of this study was to evaluate HCV compartmentalization in tumoral, non-tumoral liver tissue and serum and to identify viral mutations potentially involved in carcinogenesis. Samples were obtained from four patients with HCC who underwent liver transplantation. Core and E2 were amplified, cloned and sequenced. Phylogenies and BaTS Test were performed to analyze viral compartmentalization and a signature sequence analysis was conducted by VESPA. The likelihood and Bayesian phylogenies showed a wide degree of compartmentalization in the different patients, ranging from total clustering to a more scattered pattern with small groups. Nevertheless, the association test showed compartmentalization for the three compartments and both viral regions tested in all the patients. Signature amino acid pattern supported the compartmentalization in three of the cases for E2 protein and in two of them for Core. Changes observed in Core included polymorphism R70Q/H previously associated with HCC. In conclusion, evidence of HCV compartmentalization in the liver of HCC patients was provided and further biological characterization of these variants may contribute to the understanding of carcinogenesis mediated by HCV infection. © 2016 Wiley Periodicals, Inc.

Ras-mediated deregulation of the circadian clock in cancer.

Circadian rhythms are essential to the temporal regulation of molecular processes in living systems and as such to life itself. Deregulation of these rhythms leads to failures in biological processes and eventually to the manifestation of pathological phenotypes including cancer. To address the questions as to what are the elicitors of a disrupted clock in cancer, we applied a systems biology approach to correlate experimental, bioinformatics and modelling data from several cell line models for colorectal and skin cancer. We found strong and weak circadian oscillators within the same type of cancer and identified a set of genes, which allows the discrimination between the two oscillator-types. Among those genes are IFNGR2, PITX2, RFWD2, PPARγ, LOXL2, Rab6 and SPARC, all involved in cancer-related pathways. Using a bioinformatics approach, we extended the core-clock network and present its interconnection to the discriminative set of genes. Interestingly, such gene signatures link the clock to oncogenic pathways like the RAS/MAPK pathway. To investigate the potential impact of the RAS/MAPK pathway - a major driver of colorectal carcinogenesis - on the circadian clock, we used a computational model which predicted that perturbation of BMAL1-mediated transcription can generate the circadian phenotypes similar to those observed in metastatic cell lines. Using an inducible RAS expression system, we show that overexpression of RAS disrupts the circadian clock and leads to an increase of the circadian period while RAS inhibition causes a shortening of period length, as predicted by our mathematical simulations. Together, our data demonstrate that perturbations induced by a single oncogene are sufficient to deregulate the mammalian circadian clock.

In vitro assessment of hepatoprotective agents against damage induced by acetaminophen and CCl4.

BACKGROUND: In vitro bioassays are important in the evaluation of plants with possible hepatoprotective effects. The aims of this study were to evaluate the pretreatment of HepG2 cells with hepatoprotective agents against the damage induced by carbon tetrachloride (CCl4) and paracetamol (APAP). METHODS: Antioxidative activity was measured using an assay to measure 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The in vitro hepatotoxicity of CCl4 and APAP, and the cytotoxic and hepatoprotective properties of silymarin (SLM), silybinin (SLB), and silyphos (SLP) were evaluated by measuring cell viability; activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH); total antioxidant capacity (TAOxC); and reduced glutathione (GSH), superoxide dismutase (SOD), and lipid peroxidation (malondialdehyde (MDA) levels). RESULTS: Only SLB and SLM showed strong antioxidative activity in the DPPH assay (39.71 ± 0.85 µg/mL and 14.14 ± 0.65 µg/mL, respectively). CCl4 induced time- and concentration-dependent changes. CCl4 had significant effects on cell viability, enzyme activities, lipid peroxidation, TAOxC, and SOD and GSH levels. These differences remained significant up to an exposure time of 3 h. APAP induced a variety of dose- and time-dependent responses up to 72 h of exposure. SLM, SLB, and SLP were not cytotoxic. Only SLB at a concentration of 100 µg/mL or 150 µg/mL significantly decreased the enzyme activities and MDA level, and prevented depletion of total antioxidants compared with CCl4. CONCLUSIONS: CCl4 was more consistent than APAP in inducing cell injury. Only SLB provided hepatoprotection. AST, LDH, and MDA levels were good markers of liver damage.

Evaluation of hypocholesterolemic activity of extracts of Bidens odorata and Brickellia eupatorioides.

We sought to evaluate the hypolipidemic activity of extracts of Bidens odorata and Brickellia eupatorioides using a model of hyperlipidemia induced in rats by Triton WR-1339 (300mg/kg intraperitoneally). The rats were divided into 5 groups of 3 rats each: normal control group, hyperlipidemic control group, hyperlipidemic with 20 mg/kg atorvastatin, hyperlipidemic with 300 mg/kg B. odorata extract, and hyperlipidemic with 300mg/kg B. eupatorioides extract, respectively. After 10 d of treatment by intragastric administration, the extract of B. odorata caused a significant decrease of serum total cholesterol and triglyceride levels without altering the liver enzymes aspartate transaminase and alanine aminotransferase. In addition, the extract had antioxidant potential as shown by the 2,2-diphenyl-1-picrylhydrazyl technique. These findings indicate that B. odorata has potential as a hypolipidemic agent and might be beneficial in treatment of hyperlipidemia and atherosclerosis.