O gene rbcL como barcode para identificação forense de Cannabis sativa

<em>Cannabis sativa</em> é uma das espécies mais antigas de plantas domesticadas e permanece como uma das culturas mais amplamente difundida e a droga ilícita mais consumida no mundo. Há uma grande difi culdade em identifi car e individualizar as amostras de Cannabis sp, difi cultando a correlação a prováveis locais de plantações ilegais, o que permitiria revelar rotas de tráfi co, relacionar grupos criminosos e distinguir amostras legais daquelas comercializadas como droga, onde o cultivo é permitido. A principal fi nalidade do DNA Barcode é o de proporcionar uma rápida e precisa identifi cação de organismos a partir de uma pequena região padronizada do genoma que ajuda a caracterizar e distinguir espécies e indivíduos não identifi cados para atribuir à espécie. Um dos genes candidatos é o ribulose-1,5-bisfosfato carboxilase/oxigenase (rbcL), utilizado como um sistema de DNA Barcode e presente no DNA dos cloroplastos das plantas, sendo o responsável pela produção subunidade maior da que converte dióxido de carbono e água em carboidratos.Nosso objetivo é o desenvolvimento de um protocolo efi ciente de extração de DNA e de sequenciamento do gene rbcL para análise forense de amostras apreendidas da Polícia Judiciária. DNA de amostras de Cannabis sativa,caracterizadas no ICCE/DGPTC/PCERJ, foi extraído utilizandoo Mini DNeasy Plant (Qiagen)no IPPGF/DGPTC/PCERJ. O material foi transferido para o LabFor/UFRJe um fragmento de 735 pb do gene rbcL foi amplifi cado através de um par de iniciadores descritos na literatura como universais para plantas.O fragmento foi sequenciado, com o protocolo do BigDye v3.1, usando ABI 3500 (Life Technologies). As comparações das sequências foram realizadas no software Geneious (Biomatters). A nossa sequência consenso de 559 pb foi comparada às seqüências que correspondem às regiões rbcL em <em>Cannabis sativa</em> depositadas no GenBank, e observamos a ocorrência de polimorfi smos (SNPs) entre as amostras dos Estados unidos, Reino Unido e China, sugerindo que se trata de uma assinatura genética para análise forense.

Effectiveness of two intracanal dressings in adult Portuguese patients: a qPCR and anaerobic culture assessment

AIM

To quantify bacterial equivalents before and after chemomechanical preparation using 3% sodium hypochlorite (NaOCl) and intracanal dressing with calcium hydroxide paste (Ca(OH)2 ) or 2% Chlorhexidine digluconate gel (CHX) in necrotic pulps associated or not with apical periodontitis and to further compare this quantification with counts of anaerobic microorganisms.

METHODOLOGY

Prospective clinical trial in 69 single-rooted adult teeth (strict inclusion criteria); CHX group: 34; Ca(OH)2 group: 35. Bacteria samples were taken at baseline (S1), after chemomechanical preparation (S2) and after 14 days of intracanal dressing (S3). Bacterial equivalents were assessed by broad-range real-time polymerase chain reaction (qPCR), and live viable bacteria measured with conventional anaerobic culture (CFU/mL). Descriptive/inferential analysis was performed with spss vs. 20.0 (α = 0.05) using the Kruskal-Wallis, Mann-Whitney and chi-squared tests and Spearman's correlation coefficients.

RESULTS

Both groups showed a significant decrease between S1 and S2 (Mann-Whitney U-test; P < 0.001) both in qPCR and in culture. In the Ca(OH)2 -group, no variation was observed between S2 and S3 by qPCR and culture. In contrast, the CHX group showed a significant increase from S2 to S3 by both techniques. The two groups were only significantly different in S3 (Mann-Whitney U-test; P ≤ 0.001), with a worse performance in the CHX group. Again, these results were congruent by both approaches. Data from both approaches correlate reasonably (rS < 0.5).

CONCLUSIONS

Infected root canals contained a high bacterial load, and the chemomechanical root canal preparation reduced bacterial equivalents by 99.1% and anaerobic counts by 98.5%. Intracanal dressings were not efficient at reducing bacterial load, but the 14-day intracanal dressing with Ca(OH)2 performed significantly better than CHX, particularly in cases with apical periodontitis.

Enantiomeric HPLC resolution and absolute stereochemistry assignment of a new poligamain derivative

A new aryltetralin lignan derivative, 1, was obtained by reacting dimethyl succinate and piperonal, furnishing the lactone 4-(3',4'-methylenedioxybenzyl)-4,5-dihydro-2(3H)-furanone, which was reacted once again with piperonal and LDA to give the dibenzylbutirolactone 7-hydroxyhinokinin. The cyclization of 7-hydroxyhinokinin into polygamain occurred in the presence of trifluoroacetic acid. The reduction of the furanic ring of polygamain was done by its reaction with DIBAL in THF, furnishing the diol functionalized lignin derivative 1 as single diastereomer. The enantiomeric fractions of 1 were obtained by preparative enantioselective HPLC. The absolute stereochemistry was assigned by electronic circular dichroism (ECD) and nuclear magnetic resonance (NMR) spectroscopy. An all-trans relative configuration was determined by NMR on the bases of ¹H coupling constants and nuclear Overhauser effect (n.O.e.) experiments. The absolute configuration at C1 was assigned on the basis of the ECD sign at 296 nm by comparison to the ECD spectra of structural analogues with defined stereochemistry. The assignment of the absolute configuration was confirmed by applying the exciton chirality method to the well-defined ECD couplets at 285 and 200 nm allied to the two electronic transitions L(b) and B(b) of the aromatic moieties, respectively. Rac-1 and its enantiomeric isomers were evaluated against important bacteria responsible for dental caries. The best results obtained for the (1R,2S,3S) isomer were against Streptococcus mutans (250 μM), Streptococcus salivarius (250 μM), Streptococcus sobrinus (280 μM) and Streptococcus mitis (280 μM). The (1S,2R,3R) isomer was active only against Streptococcus sanguinis (280 μM). The enantiomeric mixture was less active than the (1R,2S,3S) isomer.

The Neuroid: A novel and simplified neuron-model

In this paper we introduce a novel computational neuron-model, the Neuroid, which is based on three basic operations that are carried out by nerve cells to process the incoming information, such as comparison, and frequency pulse modulation-demodulation. The model was implemented using LabVIEW 10.0, in order to assign to each of these operations, an execution block (Virtual Instrument). The results of its implementation showed a very similar behavior to that exhibited by real neurons. Furthermore, due to its simplicity and low computational requirements, it is expected that the Neuroid can be used to create several software models of biological neural systems, either for research or teaching purposes.

Morphopathological features of a severe ulcerative disease outbreak associated with Tenacibaculum maritimum in cultivated sole, Solea senegalensis (L.)

This study describes morphopathologic changes in naturally infected farmed Senegalese sole affected by tenacibaculosis caused by Tenacibaculum maritimum. Macroscopic observation, in addition to light microscopy and scanning electron microscopy, was used to study the lesions. Main lesions were characterized by complete loss of epidermis and dermis, as well as extensive necrosis of muscle layers. Mild-to-moderate inflammatory response with the presence of macrophages was noted around hyaline degenerated muscle cells. Gram-negative filamentous bacteria could be detected only at the dermis. Under scanning electron microscopy, filamentous bacteria located over the scales without epithelium could be observed. These findings together with the isolation and PCR detection of the bacteria in kidney and skin tissues suggest that once the bacteria reach the dermis, probably through eroded epidermis, they are able to proliferate and produce enzymes that are responsible for the damage in the underlying tissues.