A novel method for DNA delivery into bacteria using cationic copolymers.

Amphiphilic copolymers have a wide variety of medical and biotechnological applications, including DNA transfection in eukaryotic cells. Still, no polymer-primed transfection of prokaryotic cells has been described. The reversible addition-fragmentation chain transfer (RAFT) polymer synthesis technique and the reversible deactivation radical polymerization variants allow the design of polymers with well-controlled molar mass, morphology, and hydrophilicity/hydrophobicity ratios. RAFT was used to synthesize two amphiphilic copolymers containing different ratios of the amphiphilic poly[2-(dimethyl-amino) ethyl methacrylate] and the hydrophobic poly [methyl methacrylate]. These copolymers bound to pUC-19 DNA and successfully transfected non-competent Escherichia coli DH5α, with transformation efficiency in the range of 103 colony-forming units per µg of plasmid DNA. These results demonstrate prokaryote transformation using polymers with controlled amphiphilic/hydrophobic ratios.

A novel method for DNA delivery into bacteria using cationic copolymers

Amphiphilic copolymers have a wide variety of medical and biotechnological applications, including DNA transfection in eukaryotic cells. Still, no polymer-primed transfection of prokaryotic cells has been described. The reversible addition-fragmentation chain transfer (RAFT) polymer synthesis technique and the reversible deactivation radical polymerization variants allow the design of polymers with well-controlled molar mass, morphology, and hydrophilicity/hydrophobicity ratios. RAFT was used to synthesize two amphiphilic copolymers containing different ratios of the amphiphilic poly[2-(dimethyl-amino) ethyl methacrylate] and the hydrophobic poly [methyl methacrylate]. These copolymers bound to pUC-19 DNA and successfully transfected non-competent Escherichia coli DH5α, with transformation efficiency in the range of 103 colony-forming units per µg of plasmid DNA. These results demonstrate prokaryote transformation using polymers with controlled amphiphilic/hydrophobic ratios.

Solitary lung cavities: CT findings in malignant and non-malignant disease.

AIM: To assess the computed tomography (CT) findings of solitary cavitary lesions which could potentially aid in differentiating malignant from non-malignant lung disease. MATERIALS AND METHODS: A retrospective study of patients diagnosed with a solitary lung cavity at two university hospitals, who underwent multidetector CT examinations of the chest between 2012 and 2014, was performed. Lesions were evaluated for maximum diameter, maximum wall thickness, and associated findings. Statistical analyses were then conducted and a receiver operating characteristic (ROC) curve was calculated to select the most accurate cut-off value for malignant and non-malignant lesions. RESULTS: CT and clinical records from 96 patients were reviewed. The most frequent aetiologies of non-malignant and malignant lung cavities were mycobacterial infection sequelae (50%, 33/66) and primary lung carcinoma (94%, 28/30), respectively. Significant differences (p<0.05) were found between malignant and non-malignant cases when comparing the averages of maximum wall thickness (15.2 and 7.8 mm, respectively) and maximum diameter of lesions (51 and 35 mm, respectively). The presence of either perilesional consolidation or centrilobular nodules favoured the diagnosis of non-malignant conditions (p<0.05). Maximum wall thicknesses thresholds of ≤7 or ≥24 mm were the most accurate in suggesting non-malignant and malignant aetiologies, respectively. CONCLUSION: Malignant and non-malignant solitary lung cavities differ significantly at CT. Non-malignant lesions tend to exhibit thinner walls, but more perilesional consolidation and centrilobular nodules than malignant lesions. The results reveal that maximum wall thicknesses of ≤7 and ≥24 mm are indicative of non-malignant and malignant disease, respectively.

Anurofauna of an Atlantic Rainforest fragment and its surroundings in Northern Rio de Janeiro State, Brazil.

We carried out a study on the anurofaunal community from an Atlantic Forest fragment (Monte Verde mountains) and the surrounding area in Cambuci municipality, Rio de Janeiro State, Brazil, which constitutes one of the largest fragments remaining in the largely deforested landscape of the northern portion of the State. We combined three sampling methods: plot sampling, transects and pit-fall traps. We recorded twenty species of amphibians, of which only eleven were found within the forest fragment (and five of these also occurred in the surrounding matrix). Two of the species recorded in the present study (Crossodactylus sp. and Ischnocnema cf. parva) may represent undescribed taxa. Our records expand the distribution range of one species (Scinax trapicheiroi) to the north, and fill a geographic distribution gap for another one (Ischnocnema oea). The estimated overall density of frogs living in the leaf litter of the fragment (based on results of plot sampling) was 3.1 individuals/100 m², with Haddadus binotatus being the most abundant species (2.4 individuals/100 m²). Comparisons of our data with those of other studies suggest that anuran communities in forest fragments ca. 1,000 ha or smaller may be severely limited in their richness, and often include a large proportion of species tolerant to open areas, such as many hylids. Our results show the importance of increasing knowledge about the anurofaunal community of the northern portion of the State of Rio de Janeiro and preserve the forest remnants that still exist in the region.