Cell cultures of Maytenus ilicifolia Mart. are richer sources of quinone-methide triterpenoids than plant roots in natura

The quinone-methide triterpenoids (QMTs) are chemotaxonomic markers of the family Celastraceae and many compounds of this class possess important anticancer and anti-inflammatory activities. However, the levels of QMTs in the roots of Celastraceous species are typically very low (ca. 0.0003 %) and commercial production by extraction from such tissues would not be commercially viable. With the aim of determining if cells cultured in vitro might provide alternative sources of these bioactive triterpenoids, we have quantified and compared the concentrations of QMTs accumulated by the roots of plants of Maytenus ilicifolia Mart. ex Reissek (Celastraceae) aged 0.5–10 years, and in callus and suspension cultures derived from a cell line that had been subcultured over a period of 10 years. Comparing plants cultivated in natura, the highest levels of QMTs were detected in the root bark of 5-year old specimens. However, cell suspensions derived from the long-term cell line retained their capacity to synthesize and accumulate QMTs, and presented levels of maytenin, 22β-hydroxymaytenin, celastrol and pristimerin that were, respectively, 1.96-, 2.48-, 8.85- and 3.29-times higher than those in the roots of 5-year old plants. The results presented herein open up new possibilities for the large-scale production of QMTs and for the development of novel pharmaceuticals.     

Cellular interplay in pulmonary arterial hypertension: Implications for new therapies

Pulmonary arterial hypertension (PAH) is a complex and multifactorial disease characterized by vascular remodeling, vasoconstriction, inflammation and thrombosis. Although the available therapies have resulted in improvements in morbidity and survival, PAH remains a severe and devastating disease with a poor prognosis and a high mortality, justifying the need of novel therapeutic targets. An increasing number of studies have demonstrated that endothelial cells (ECs), smooth muscle cells (SMCs) and fibroblasts of the pulmonary vessel wall, as well as platelets and inflammatory cells have a role in PAH pathogenesis. This review aims to integrate the interplay among different types of cells, during PAH development and progression, and the impact of current therapies in cellular modulation. The interplay among endothelial cells, smooth muscle cells and fibroblasts present in pulmonary vessels wall, platelets and inflammatory cells is regulated by several mediators produced by these cells, contributing to the pathophysiologic features of PAH. Current therapies are mainly focused in the pulmonary vascular tone and in the endothelial dysfunction. However, once they have not been effective, novel therapies targeting other PAH features, such as inflammation and platelet dysfunction are emerging. Further understanding of the interplay among different vascular cell types involved in PAH development and progression can contribute to find novel therapeutic targets, decreasing PAH mortality and morbidity in the future.     

The ruthenium complexes cis-(dichloro)tetramineruthenium(III) chloride and cis-tetraammine(oxalato)ruthenium(III) dithionate overcome resistance inducing apoptosis on human lung carcinoma cells (A549)

Lung cancer is one of the leading causes of death in the world, and non-small cell lung carcinoma accounts for approximately 75–85 % of all lung cancers. In the present work, we studied the antitumor activity of the compound cis-(dichloro)tetramineruthenium(III) chloride {cis-[RuCl₂(NH₃)₄]Cl} against human lung carcinoma tumor cell line A549. The present study aimed to investigate the relationship between the expression of MDR1 and CYP450 genes in human lung carcinoma cell lines A549 treated with cisCarboPt, cisCRu(III) and cisDRu(III). The ruthenium-based coordinated complexes presented low cytotoxic and antiproliferative activities, with high IC₅₀ values, 196 (±15.49), 472 (±20.29) and 175 (±1.41) for cisCarboPt, cisCRu(III) and cisDRu(III), respectively. The tested compounds induced apoptosis in A549 tumor cells as evidenced by caspase 3 activation, but only at high concentrations. Results also revealed that the amplification of P-gp gene is greater in A549 cells exposed to cisCarboPt and cisCRu(III) than cisDRu(III). Taken together all these results strongly demonstrate that MDR-1 over-expression in A549 cells could be associated to a MDR phenotype of these cells and moreover, it is also contributing to the platinum, and structurally-related compound, resistance in these cells. The identification and characterization of novel mechanisms of drug resistance will enable the development of a new generation of anti-cancer drugs that increase cancer sensitivity and/or represent more effective chemotherapeutic agents.     

A Selective Sweep on a Deleterious Mutation in CPT1A in Arctic Populations

Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype data from native Siberians have previously highlighted a 3 Mb chromosome 11 region containing 79 protein-coding genes as the strongest candidates for positive selection in Northeast Siberians. However, it was not possible to determine which of the genes might be driving the selection signal. Here, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele is associated with hypoketotic hypoglycemia and high infant mortality yet occurs at high frequency in Canadian and Greenland Inuits and was also found at 68% frequency in our Northeast Siberian sample. We provide evidence of one of the strongest selective sweeps reported in humans; this sweep has driven this variant to high frequency in circum-Arctic populations within the last 6–23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment.     

Improved Flutter Ablation Outcomes Using a 10mm-tip Ablation Catheter

Introduction

Radiofrequency(RF) ablation has become the first line of therapy for atrial flutter(AFL). Advances in catheter and mapping technologies have led to better understanding and different approaches for treating this arrhythmia. We describe the results of different approaches to ablate this arrhythmia.

Materials and Methods

A cohort of 198 patients with isthmus dependent AFL. The techniques used were: 10mm-tip catheter with power set to 100w, 8mm-tip catheter with power set to 60W and irrigated tip catheter.

Results

212 procedures, including redos were done in 198 consecutive patients. We used irrigated tip catheters in 14 procedures, 8mm-tip in 55 procedures, and 10mm-tip in 143 procedures. Bidirectional block was achieved in 97.6% of cases with all techniques, with no difference among them. Procedure time was shorter in the 10mm-tip versus 8mm-tip(69.6±30.6min vs.105±43min) or irrigated tip(180±90min) (P<0.05). Fluoroscopy time was also shorter in the 10mm-tip versus 8mm-tip (24±18min vs. 37±23min) or irrigated tip (110±25min)(P<0.05). The cumulative incidence of failure during follow-up was 1.2%/year in the 10mm, 10.1%year in the 8mm and 6.9%year in the irrigated tip. The survival free of a new procedure was significantly higher among 10mm patients.

Conclusions

In our series we found a high rate of acute success with the use of different techniques for AFL ablation. Procedure and fluoroscopic times were shorter with the use of 10mm-tip as compared with the others techniques. The long-term risk of recurrence was lower when we used the 10mm-tip catheter and the survival free of a second procedure was higher among patients treated with this catheter.     

Characterization of lipopeptides from <Emphasis Type="Italic">Paenibacillus</Emphasis> sp. (IIRAC30) suppressing <Emphasis Type="Italic">Rhizoctonia solani</Emphasis>

The main aim was to identify the active compound against Rhizoctonia solani produced by the cassava endophyte Paenibacillus sp. IIRAC-30. The compounds produced were extracted with ethyl acetate and purified by Sephadex column prior to analysis by Q-TOF mass spectrometry. A C₁₅-lipopeptide with an estimated molecular weight of 1036 Da and homologues were identified. The lipopeptide had a cyclic structure, which was deduced by interpreting the ESI–MS/MS spectra of main protonated homologues containing 15:0 FA, and the amino acid composition was Glu-Leu-Leu-Val-Asp-Leu-Leu. Therefore, the lipopeptides produced by isolate IIRAC-30 was characterized as a surfactin series. Thus, the main mechanism used by Paenibacillus sp. IIRAC-30 to suppress R. solani was elucidated. Furthermore, because lipopeptides active against phytopathogens generally show low toxicity to humans and the environment, the positive findings presented here suggest that the isolate IIRAC-30 could be a possible candidate for biocontrol of R. solani.     

Targeted expression of catalase to mitochondria prevents age-associated reductions in mitochondrial function and insulin resistance

Aging-associated muscle insulin resistance has been?hypothesized to be due to decreased mitochondrial function, secondary to cumulative free radical damage, leading to increased intramyocellular lipid content. To directly test this hypothesis, we examined both in?vivo and in?vitro mitochondrial function, intramyocellular lipid content, and insulin action in lean healthy mice with targeted overexpression of the human catalase gene to mitochondria (MCAT mice). Here, we show that MCAT mice are protected from age-induced decrease in muscle mitochondrial function (～30%), energy metabolism (～7%), and lipid-induced muscle insulin resistance. This protection from age-induced reduction in mitochondrial function was associated with reduced mitochondrial oxidative damage, preserved mitochondrial respiration and muscle ATP synthesis, and AMP-activated protein kinase-induced mitochondrial biogenesis. Taken together, these data suggest that the preserved mitochondrial function maintained by reducing mitochondrial oxidative damage may prevent age-associated whole-body energy imbalance and muscle insulin resistance.     

TRAP: automated classification, quantification and annotation of tandemly repeated sequences

TRAP, the Tandem Repeats Analysis Program, is a Perl program that provides a unified set of analyses for the selection, classification, quantification and automated annotation of tandemly repeated sequences. TRAP uses the results of the Tandem Repeats Finder program to perform a global analysis of the satellite content of DNA sequences, permitting researchers to easily assess the tandem repeat content for both individual sequences and whole genomes. The results can be generated in convenient formats such as HTML and comma-separated values. TRAP can also be used to automatically generate annotation data in the format of feature table and GFF files.     

Metabolical changes induced by chronic phenol exposure in matrinxã Brycon cephalus (teleostei: characidae) juveniles

Phenol and its derivatives are xenobiotics present in many industrial wastewaters and in non-specific pesticides. It is a lipophilic compound and, therefore, accumulates along the trophic chain. Phenol is often found in marine and fresh water environments. The aim of this work was to detect metabolic changes induced by phenol in Brycon cephalus juveniles. Several enzymes activities and metabolites were quantified in the liver, white muscle and plasma. Among the enzymes assayed are alanine and aspartate amino transferases (ALAT and ASAT), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH). Glucose, glycogen, lactate, ammonia and pyruvate were also quantified in tissues and plasma (glycogen in tissues only). The liver was the most responsive organ. The activities of the transaminases increased in muscle and liver, followed by an increase in hepatic ammonia. Correlation between ammonia and transaminases points towards phenol-induced consumption of protein. Hepatic glycogen and glucose contents were lower followed exposure to phenol. The same was observed for muscle glucose, suggesting considerable use of carbohydrate stores. The activity of hepatic lactate dehydrogenase increased with negative correlation with muscle lactate. This suggests that hepatic gluconeogenesis supplies tissues like muscle and brain with glucose. These results indicate that phenol intoxication demands metabolic energy and leads to significant changes of the metabolic profile of the fish, inducing to a certain extent a shift from carbohydrate catabolism to protein catabolism and the activation of gluconeogenesis.