Signal enhancement in DNA microarray using dye doped silica nanoparticles: application to human papilloma virus (HPV) detection

DNA microarray is a powerful tool for the parallel of nucleic acids and other biologically significant molecules. In this communication we report an easy and cheap synthesis route for incorporating organic dyes into monodisperse inorganic silica nanoparticles and their application on the detection of carcinogenic risky Human Papilloma Virus using DNA microarray technology. We correlate our system with conventional direct dyes and commercial quantum dots, with a promising increase in optical signal, and a related decrease of the limit of detection, thus giving a remarkable improvement in this technique towards early diagnosis of diseases and trace level detection of dangerous biological contaminants.     

Performance of a mobile mechanical screen to improve the commercial quality of wood chips for energy

The study analyzed the performance of a mobile screening device for upgrading coarse wood chips to residential user standards, by removing oversize particles and fines. The machine was designed for transportation to forest landings, logistic terminals and plant chip yards. Average productivity was 1.9 oven-dry tons (odt) h⁻¹, corresponding to a screening cost of 28.5 € odt⁻¹. This figure was lower than the price increase obtained by upgrading industrial chips to residential user standards. Hence, screening offered a profit of 4.7 € odt⁻¹, or 16% of the original screening cost. The screening process was capable of upgrading chips from industrial to residential specifications, by reducing the incidence of oversize particles below the 1% critical threshold. Screening also allowed a substantial reduction in the content of fines. A similar effect was not verified for crushed wood, which failed to meet the specifications for residential fuel.     

Receptor activator of NF-kB (RANK) expression in primary tumors associates with bone metastasis occurrence in breast cancer patients

Background

Receptor activator of NFkB (RANK), its ligand (RANKL) and the decoy receptor of RANKL (osteoprotegerin, OPG) play a pivotal role in bone remodeling by regulating osteoclasts formation and activity. RANKL stimulates migration of RANK-expressing tumor cells in vitro, conversely inhibited by OPG.

Materials and Methods

We examined mRNA expression levels of RANKL/RANK/OPG in a publicly available microarray dataset of 295 primary breast cancer patients. We next analyzed RANK expression by immunohistochemistry in an independent series of 93 primary breast cancer specimens and investigated a possible association with clinicopathological parameters, bone recurrence and survival.

Results

Microarray analysis showed that lower RANK and high OPG mRNA levels correlate with longer overall survival (P = 0.0078 and 0.0335, respectively) and disease-free survival (P = 0.059 and 0.0402, respectively). Immunohistochemical analysis of RANK showed a positive correlation with the development of bone metastases (P = 0.023) and a shorter skeletal disease-free survival (SDFS, P = 0.037). Specifically, univariate analysis of survival showed that “RANK-negative” and “RANK-positive” patients had a SDFS of 105.7 months (95% CI: 73.9–124.4) and 58.9 months (95% CI: 34.7–68.5), respectively. RANK protein expression was also associated with accelerated bone metastasis formation in a multivariate analysis (P = 0.029).

Conclusions

This is the first demonstration of the role of RANK expression in primary tumors as a predictive marker of bone metastasis occurrence and SDFS in a large population of breast cancer patients.     

Heterologous amplification and characterization of microsatellite markers in the Neotropical fish Leporinus friderici

Leporinus friderici, native to the Amazon Basin and popularly known as "piau-três-pintas", has great ecological and economic importance; it is widely fished and consumed throughout much of tropical South America. Knowledge of the genetic diversity of this native species is important to support management and conservation programs. We evaluated microsatellite loci amplification, using heterologous primers, in 31 individuals of L. friderici. These samples were collected from natural populations of the Araguaia River basin, in central Brazil, and the DNA was extracted from samples of muscle tissue. Eight loci were successfully analyzed. Six of them were polymorphic, and the number of alleles ranged from three to 10. Values of expected heterozygosities for these polymorphic loci ranged from 0.488 to 0.795. Exclusion probability (0.983), the identity probability (0.000073), and the mean genetic diversity values were high, showing that these microsatellite markers are suitable for assessing the genetic variability of L. friderici populations. There is a growing interest in studies that evaluate the genetic variability of natural populations for various purposes, such as conservation. Here, we showed that a viable alternative to the costly development of specific primers for fish populations is simply testing for heterologous amplification of microsatellite markers available from research on other species.     

Crystal structures and proposed structural/functional classification of three protozoan proteins from the isochorismatase superfamily

We have determined the crystal structures of three homologous proteins from the pathogenic protozoans Leishmania donovani, Leishmania major, and Trypanosoma cruzi. We propose that these proteins represent a new subfamily within the isochorismatase superfamily (CDD classification cd004310). Their overall fold and key active site residues are structurally homologous both to the biochemically well-characterized N-carbamoylsarcosine-amidohydrolase, a cysteine hydrolase, and to the phenazine biosynthesis protein PHZD (isochorismase), an aspartyl hydrolase. All three proteins are annotated as mitochondrial-associated ribonuclease Mar1, based on a previous characterization of the homologous protein from L. tarentolae. This would constitute a new enzymatic activity for this structural superfamily, but this is not strongly supported by the observed structures. In these protozoan proteins, the extended active site is formed by inter-subunit association within a tetramer, which implies a distinct evolutionary history and substrate specificity from the previously characterized members of the isochorismatase superfamily. The characterization of the active site is supported crystallographically by the presence of an unidentified ligand bound at the active site cysteine of the T. cruzi structure.     

Oxysterol-induced up-regulation of MCP-1 expression and synthesis in macrophage cells

To investigate the proinflammatory potential of cholesterol and cholesterol oxidation products (oxysterols), which are present in oxidized low-density lipoproteins, foam cells, and fibrotic plaque, we used an in vitro model mimicking the challenge of macrophage cells by the cholesterol accumulating within the central core of atheroma. A biologically representative oxysterol mixture was shown to be potentially able to sustain a chronic inflammatory process within the vascular wall by up-regulating the expression of defined proinflammatory genes. In particular, expression and synthesis of the major chemokine for monocytes/macrophages, namely monocyte chemotactic protein-1 (MCP-1), were consistently increased when cells of the macrophage lineage (U937 cell line) were incubated with this mixture. On the contrary, an identical concentration of unoxidized cholesterol in no case modified expression or synthesis of the chemokine. Up-regulated expression and synthesis of MCP-1 by the oxysterol mixture was clearly dependent on a net increment of phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and nuclear factor kappaB (NF-kappaB) nuclear binding. The results indicate that cholesterol may contribute to the progression of atherosclerotic lesions by strongly up-regulating crucial proinflammatory factors like MCP-1, but only after having been oxidized to oxysterols.     

Synthesis, solution structure, and bioactivity of six new simplified analogues of the natural cyclodepsipeptide jaspamide

Recently, we described the synthesis and the biological evaluation of three modified analogues of jaspamide (1), a natural cyclodepsipeptide possessing a potent antitumor activity as a consequence of its ability to interfere with actin cytoskeleton. To obtain additional information on the potential pharmacophoric core of the target molecule, which is of fundamental importance to discover new and more effective anticancer products, we decided to explore the biological effects of further structural modifications carried out on the parent molecule. The synthesis and the chemical characterization of six jaspamide analogues (2-7) are reported and their conformational and biological properties are described.     

Injection of colorectal cancer cells in mesenteric and antimesenteric sides of the colon results in different patterns of metastatic diffusion: An experimental study in rats

Background

Parathyroid carcinoma is a rare malignancy, with an incidence of 0.5 to 4% of all cases of primary hyperparathyroidism. Surgery is the only curative treatment.

Case presentation

We report the case of a 66-year-old man referred for a large suspicious substernal goitre associated with severe hypercalcemia due to hyperparathyroidism. After normalization of serum calcium levels, patient underwent surgery. The voluminous cervicomediastinal firm mass could not be removed through the cervical incision; therefore a cervicothoracic approach was employed. Histopathology revealed a giant parathyroid cancer of 450 grams. A review of the literature was also undertaken to summarize the current treatment approaches for this rare malignancy.

Conclusion

Parathyroid cancer is usually not recognized either preoperatively or intra-operatively. En bloc resection of the tumour with the adjacent tissue is the treatment of choice and it is very important to avoid the rupture of the capsule during operation. Neither tumour size, nor the lymph node status appears to play a role in prognosis. The management of parathyroid carcinoma is a challenge even for experienced surgeons.