Electrochemical Investigation of Oligonucleotide-DNA Hybridization on Poly(4-Methoxyphenethylamine)

This work describes the immobilization of purine and pyrimidine bases and immobilization/hybridization of synthetic oligonucleotides on graphite electrodes modified with poly(4-methoxyphenethylamine) produced in acid medium. The immobilization of adenine, guanine, cytosine and thymine on these modified electrodes was efficient, producing characteristic peaks. Another relevant observation is that, according to the literature, pyrimidine bases, cytosine and thymine are more difficult to detect. However, when immobilized onto the poly(4-methoxyphenethylamine), a significant increase in the magnitude of the current was obtained. The observation of the hybridization between the poly(GA) probe and its complementary, poly(CT) target, was possible by monitoring the guanosine and adenosine peaks or through methylene blue indicator, using differential pulse voltammetry. Hybridization results in a decrease of the peak current of guanosine and adenosine or the signal of methylene blue accumulated on the modified electrode surface. The hybridization with the complementary target was also investigated by electrochemical impedance spectroscopy. The results showed a significant modification in the Nyquist plot, after addition of the complementary target, with increase of the charge transference resistance

Drug polarity effect over the controlled release in casein and chondroitin sulfate-based hydrogels

This study compared the controlled release of two drugs: vitamin-B12, and l-dopa from hydrogels based on 50% of casein (CAS, a protein), 50% of chondroitin sulfate (CS, a polysaccharide) and different amounts of SiO2. The results indicated that the incorporation of 5% of SiO2 to the materials, allowed the best organization, distribution, and diameter of the pores, which are responsible for ensuring a more controlled release. Also, the matrices were not efficient in releasing vitamin-B12, but it successfully released l-dopa. It happened because vitamin-B12 is highly hydrophilic, interacting more with the medium than with the CAS/CS matrix, while l-dopa is less polar than vitamin-B12, interacting more with the CAS/CS matrix. It is worth mentioning that all synthesized hydrogels were non-toxic to the cells as showed by the in vitro assay. This work also demonstrated the importance of evaluating drug delivery devices using drugs of different polarities before stating if they are efficient or not158116126CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFINANCIADORA DE ESTUDOS E PROJETOS - FINEPsem informaçã

Antitrypanosomal Activity of Novel Benzaldehyde-Thiosemicarbazone Derivatives from Kaurenoic Acid †

A series of new thiosemicarbazones derived from natural diterpene kaurenoic acid were synthesized and tested against the epimastigote forms of Trypanosoma cruzi to evaluate their antitrypanosomal potential. Seven of the synthesized thiosemicarbazones were more active than kaurenoic acid with IC50 values between 2-24.0 mM. The o-nitro-benzaldehyde-thiosemicarbazone derivative was the most active compound with IC50 of 2.0 mM. The results show that the structural modifications accomplished enhanced the antitrypanosomal activity of these compounds. Besides, the thiocyanate, thiosemicarbazide and the p- methyl, p-methoxy, p-dimethylamine, m-nitro and o-chlorobenzaldehyde-thiosemicarbazone derivatives displayed lower toxicity for LLMCK2 cells than kaurenoic acid, exhibing an IC50 of 59.5 mM

Leptospires detection in kidney, liver and uterus of cows slaughtered in Paraná State, Brazil Detecção de leptospiras em rim, fígado e útero de fêmeas bovinas abatidas no estado do Paraná, Brasil

The objective of this trial was to detect leptospires in fragments of kidney, liver and uterus of 96 cows with unknown sanitary status, randomly chosen at slaughter in Paraná, Brazil. All 96 urine samples were submitted to direct examination using dark field microscopy. Positive samples in the direct examination and all kidney, liver and uterus fragments were cultured in EMJH modified medium and Tween 80/40/LH. Sections cut of kidney, liver and uterus were stained by Hematoxylin-Eosin (HE) and indirect immunoperoxidase with hyperimmune serum against serovar Hardjo (Hardjoprajitno) and strain Londrina 14 (LO14), from serovar Canicola, which was isolated in the northern region of Paraná state, Brazil, used as primary antibodies. Direct examination detected leptospires in the urine of four animals. All attempts to isolate leptospires from urine and kidney, liver and uterus fragments were negative after 16 weeks of incubation. In the HE stain, focal infiltrate of mononuclear inflammatory cells was observed in the renal interstitial area of most animals. In the indirect immunoperoxidase assay using hyperimmune serum against LO14 strain, the kidney of only one animal presented positive results. All fragments of kidney, liver and uterus tested with hyperimmune serum against serovar Hardjo were negative.<br>O objetivo deste trabalho foi detectar leptospiras em fragmentos de rim, fígado e útero de 96 fêmeas bovinas com histórico sanitário desconhecido, escolhidas aleatoriamente durante o abate em um frigorífico no Estado do Paraná, Brasil. Todas as 96 amostras de urina foram submetidas ao exame direto em microscópio de campo escuro. As amostras positivas neste exame e todos os fragmentos de rim, fígado e útero foram semeados nos meios de cultura EMJH modificado e Tween 80/40/LH. Os cortes histológicos de rim, fígado e útero foram submetidos à coloração de Hematoxilina-Eosina (HE) e a prova de imunoperoxidase indireta com soros hiperimunes contra o sorovar Hardjo (Hardjoprajitno) e contra a estirpe Londrina (LO14), do sorovar Canicola, isolada no norte do Paraná, Brasil, utilizados como anticorpo primário. O exame direto detectou leptospiras na urina de quatro animais. Todas as tentativas de isolamento das urinas e fragmentos de rim, fígado e útero foram negativas após 16 semanas de incubação. No exame histopatológico foi observado infiltrado focal de células mononucleares no interstício renal da maioria dos animais. Na prova de imunoperoxidase indireta com o soro hiperimune contra a estirpe LO14, o rim de um animal foi o único a apresentar resultado positivo. Todos os fragmentos de rim, fígado e útero testados com o soro hiperimune contra o sorovar Hardjo foram negativos