Characterization of novel human intragenic antimicrobial peptides, incorporation and release studies from ureasil-polyether hybrid matrix.

Intragenic antimicrobial peptides (IAPs) are internal sequences of proteins with physicochemical similarities to Antimicrobial Peptides (AMPs) that, once identified and synthesized as individual entities, present antimicrobial activity. Many mature proteins encoded by the genomes of virtually any organism may be regarded as inner reservoirs of IAPs, conferring them ample biotechnological potential. However, IAPs may also share shortcomings with AMPs, such as low half-life in biological media and non-specific adsorption in eukaryotic cells. The present manuscript reports a translational approach that encompasses the uncovering of two novel IAPs from human proteins as well as the first results concerning the incorporation and sustained release of one of these peptides from ureasil-polyether hybrid polymeric films. For such, the software Kamal was used to scan putative IAPs in the human proteome, and two peptides, named Hs05 and Hs06, were identified, synthesized, and tested as antimicrobials. Biophysical assays were conducted using model phospholipid vesicles and 1H NMR solution structures in phospholipid micelles were obtained for the IAP Hs05. This peptide was incorporated in a polymeric matrix composed of the ureasil/PPO-PEO-PPO triblock copolymer, and the resulting films were evaluated by atomic force microscopy and imaging mass spectrometry. The release rate of Hs05 from the polymeric matrix was assessed and the antimicrobial activity of Hs05-loaded hybrid polymeric films was evaluated against the bacterium Escherichia coli. This study represents the first steps towards the development of polymeric films enriched with IAPs obtained from the human proteome as sustained release devices for topical application.

Correlations in electrically coupled chaotic lasers.

We show how two electrically coupled semiconductor lasers having optical feedback can present simultaneous antiphase correlated fast power fluctuations, and strong in-phase synchronized spikes of chaotic power drops. This quite counterintuitive phenomenon is demonstrated experimentally and confirmed by numerical solutions of a deterministic dynamical system of rate equations. The occurrence of negative and positive cross correlation between parts of a complex system according to time scales, as proved in our simple arrangement, is relevant for the understanding and characterization of collective properties in complex networks.

Rediscovering hermaphroditism in Grammatidae with the description of the testicular gland in Brazilian Basslet Gramma brasiliensis / Redescobrindo o hermafroditismo em Grammatidae com a descrição da glândula testicular de Gramma brasiliensis

Abstract Many aspects of sex change in reef fishes have been studied, including behavior and social organization. However, gonad histology remains the most robust way to identify sexual patterns in fishes. Some uncommon tissues remain poorly described, such as the accessory gonadal structures found in species from the Gobiidae family, which are rare in other bony fishes. This is the first report of the testicular gland in Gramma brasiliensis and for the Grammatidae family. Between April 2011 and February 2012 eighty specimens were collected during four dive campaigns on the Taipus de Fora reef (13°56’20”S 38°55’32”W), Bahia, Northeast Brazil, and their sex was determined. Thirteen per cent of the active-females and 90% of the active-males had testicular gland tissue in their ovotestis. This discovery led to additional research into the characteristics of the gland tissue and its relationship with gonadal maturation. Three patterns of testicular gland development were found in Brazilian basslet ovotestis. Both ova and sperm-producing gonad contained testicular gland tissue, and the appearance of this tissue seems to be the first modification of ovotestis tissue marking the beginning of the protogynous sex-change process in G. brasiliensis.

Resumo Diversos aspectos da troca de sexo em peixes recifais vem sendo estudados, incluindo comportamentos e organização social. Entretanto, a histologia das gônadas continua sendo a maneira mais robusta para se identificar padrões sexuais em peixes. Alguns tecidos incomuns, tais como as estruturas anexas a gônada encontradas em espécies da família Gobiidae e raras em outras espécies são pouco estudados. Este trabalho é a primeira descrição da glândula testicular em Gramma brasiliensis e para a família Grammatidae. Entre abril de 2011 e fevereiro de 2012, oitenta espécimes foram coletados durante quatro amostragens no recife de Taipus de Fora (13°56’20”S 38°55’32”W), Bahia, Brasil, e tiveram seus sexos determinados. Treze por cento das fêmeas ativas e noventa por cento dos machos ativos apresentaram tecido da glândula testicular em suas gônadas. Esta descoberta levou ao estudo da características dessa estrutura e sua relação com a maturação gonadal. Foram identificados três padrões de desenvolvimento da glândula testicular nas gônadas do Gramma brasiliensis. Tanto as gônadas produtoras de espermatozoides quanto as de oócitos apresentaram tecido da glândula testicular, e o surgimento desse tecido parece ser a primeira modificação gonadal do início da troca de sexo protogínica em G. brasiliensis.

Evidence for spawning aggregations of the endangered Atlantic goliath grouper Epinephelus itajara in southern Brazil.

In this study, seasonal numerical abundance of the critically endangered Atlantic goliath grouper Epinephelus itajara was estimated by conducting scuba dive surveys and calculating sightings-per-unit-effort (SPUE) at three sites in southern Brazil. Seasonal differences in size and reproductive condition of captured or confiscated specimens were compared. The SPUE differed significantly with season, increasing in late spring and peaking during the austral summer months. A significant effect was observed in the number of fish relative to the lunar cycle. All females sampled during the summer were spawning capable, while all those sampled during other seasons were either regressing or regenerating. What these data strongly infer is that the E. itajara spawning aggregation sites have been located in the southern state of Paraná and the northern state of Santa Catarina and summer is the most likely spawning season. Size frequency distributions, abundance and reproductive state were estimated and correlated with environmental variables.

Rediscovering hermaphroditism in Grammatidae with the description of the testicular gland in Brazilian Basslet Gramma brasiliensis.

Many aspects of sex change in reef fishes have been studied, including behavior and social organization. However, gonad histology remains the most robust way to identify sexual patterns in fishes. Some uncommon tissues remain poorly described, such as the accessory gonadal structures found in species from the Gobiidae family, which are rare in other bony fishes. This is the first report of the testicular gland in Gramma brasiliensis and for the Grammatidae family. Between April 2011 and February 2012 eighty specimens were collected during four dive campaigns on the Taipus de Fora reef (13°56'20"S 38°55'32"W), Bahia, Northeast Brazil, and their sex was determined. Thirteen per cent of the active-females and 90% of the active-males had testicular gland tissue in their ovotestis. This discovery led to additional research into the characteristics of the gland tissue and its relationship with gonadal maturation. Three patterns of testicular gland development were found in Brazilian basslet ovotestis. Both ova and sperm-producing gonad contained testicular gland tissue, and the appearance of this tissue seems to be the first modification of ovotestis tissue marking the beginning of the protogynous sex-change process in G. brasiliensis.

Extreme events in chaotic lasers with modulated parameter.

We study a theoretical model describing a laser with a modulated parameter, concentrating on the appearance of extreme events, also called optical rogue pulses. It is shown that two conditions are required for the appearance of such events in this type of nonlinear system: the existence of generalized multi-stability and the collisions of chaotic attractors with unstable orbits in external crisis, expanding the attractor to visit new regions in phase space.

Acaricide activity in vitro of Acmella oleracea against Rhipicephalus microplus.

Cattle tick control has been limited by the resistance of these parasites to synthetic acaricides. Natural products are a possible alternative as they have different mechanisms of action. Acmella oleracea is a native plant with a large cultivated area in the Amazon region and could be easily used for large-scale preparation of a commercial product. This study evaluated the in vitro action of the hexane extract of the aerial parts of A. oleracea on larvae and engorged females of the cattle tick Rhipicephalus microplus. Spilanthol was the major constituent with a content of 14.8% in the extract. The hexane extract of A. oleracea was highly effective against larvae of R. microplus with an LC50 of 0.8 mg mL(-1). Against engorged females, hexane extract of A. oleracea reduced oviposition and hatchability of eggs with an LC50 of 79.7 mg mL(-1). Larvae and engorged females were killed by the hexane extract with high efficiency (>95%) at concentrations of 3.1 and 150.0 mg mL(-1), respectively. These results demonstrate that the hexane extract of A. oleracea has significant activity against R. microplus and has potential to be developed into formulations for tick control.

Nanoencapsulação de um peptídeo isolado de anuros: citotoxicidade in vitro em células tumorais humanas / Nanoencapsulation of a peptide isolated from anurans: in vitro cytotoxicity in human tumor cells

A terapia antineoplásica tradicional apresenta algumas limitações que podem ser superadas através da utilização dos lipossomas. Estes nanossistemas de carreamento possibilitam o direcionamento de fármacos e reduzem efeitos secundários. Alguns peptídeos catiônicos sintetizados na pele de anuros apresentam atividade citotóxica seletiva (microorganismos e/ou tumores). Neste sentido, espécies do gênero Phyllomedusa secretam as dermaseptinas. Objetivou-se neste estudo, avaliar a citotoxicidade in vitro da dermaseptina 01 (DS 01) livre e encapsulada em lipossomas unilamelares pequenos (SUVs) em células tumorais humanas. Os lipossomas foram preparados pelo método de hidratação do filme lipídico seguido de sonicação. Foram produzidas formulações neutras e catiônicas, convencionais e furtivas. A citotoxicidade foi analisada em células tumorais de pulmão (NCI-H292), cólon (HT-29) e laringe (HEp-2), pelo ensaio de redução do sal tetrazólio (MTT) em placas de 96 poços. Os lipossomas foram submetidos a testes de estabilidade acelerada e em longo prazo. Em NCI-H292, a DS 01 livre apresentou efeito citostático médio de 35,6%. A encapsulação do peptídeo em lipossomas convencionais neutros aumentou o efeito, ao contrário dos furtivos. Para HT-29 e HEp-2, a DS 01 livre inibiu o crescimento celular em aproximadamente 50%, em média. A encapsulação em lipossomas catiônicos potencializou o efeito; os lipossomas convencionais inibiram na faixa de 80% e os furtivos, mais que 95% para as duas linhagens celulares. A DS 01, um peptídeo catiônico antimicrobiano, apresentou efeito citotóxico in vitro para células tumorais humanas que foi potencializado com a nanoencapsulação...

The conventional anticancer therapies show some limitations that can be overcome by using liposomes. This type of nanocarriers allows preferential targeting of drugs and reduces undesirable secondary effects. Some cationic peptides synthesized by the skin of anurans exhibit selective cytotoxicity (to pathogens and/or tumors). Species of Phyllomedusa secrete dermaseptins (DSs). The aim of this study was to assess the in vitro cytotoxicity of free and small unilamellar vesicle (SUV)-encapsulated dermaseptin 01 (DS 01) in various human tumor cells. Liposomes were prepared by lipid film hydration followed by sonication. Neutral and cationic, conventional and stealth liposomes were produced. Cytotoxicity was analyzed in lung (NCI-H292), colon (HT-29) and larynx (HEp-2) cancer cells, by the tetrazolium reduction method (MTT) carried out in 96-well microplates. Liposomes were tested for accelerated and long-term stability. In NCI-H292, free DS 01 showed a medium cytostatic effect of 36.5%. The conventional neutral liposome encapsulation of peptide increased this effect, whereas the stealth did not. In HT-29 and HEp-2, free DS 01 inhibited the cell growth by approximately 50% on average. The cationic liposome encapsulation was synergic, inhibition being about 80% in conventional and higher than 95% in stealth liposomes for both celllines. Thus, DS 01, an antimicrobial cationic peptide, showed in vitro cytotoxicity to human tumor cells that was potentiated by nanoencapsulation...

A yoga and compassion meditation program reduces stress in familial caregivers of Alzheimer's disease patients.

Familial caregivers of patients with Alzheimer's disease exhibit reduced quality of life and increased stress levels. The aim of this study was to investigate the effects of an 8-week yoga and compassion meditation program on the perceived stress, anxiety, depression, and salivary cortisol levels in familial caregivers. A total of 46 volunteers were randomly assigned to participate in a stress-reduction program for a 2-month period (yoga and compassion meditation program-YCMP group) (n = 25) or an untreated group for the same period of time (control group) (n = 21). The levels of stress, anxiety, depression, and morning salivary cortisol of the participants were measured before and after intervention. The groups were initially homogeneous; however, after intervention, the groups diverged significantly. The YCMP group exhibited a reduction of the stress (P < 0.05), anxiety (P < 0.000001), and depression (P < 0.00001) levels, as well as a reduction in the concentration of salivary cortisol (P < 0.05). Our study suggests that an 8-week yoga and compassion meditation program may offer an effective intervention for reducing perceived stress, anxiety, depression, and salivary cortisol in familial caregivers.

In vitro synergistic interaction between amide piplartine and antimicrobial peptide dermaseptin against Schistosoma mansoni schistosomula and adult worms.

Schistosomiasis is one of the world's major public health problems, and praziquantel is the only available drug to treat this notable neglected disease. Drug combinations have been considered an important strategy for treatment of infectious diseases, which might enhance therapeutic efficacy and delaying resistance. In this study, we have examined the in vitro activities of the amide piplartine and the antimicrobial peptide dermaseptin 01 administered singly or in combination against Schistosoma mansoni of different ages including 3-hour-old and 7-day-old schistosomula and 49-day-old adult schistosomes as well as on egg output by adult worms. We calculated the median lethal concentrations (LC(50)) of 7.87 and 17.99 µM on 49-day-old adults, 11.02 and 71.58 µM on 7-day-old schistosomula, and 70.87 and 98.42 µM on 3-hour-old schistosomula for piplartine and dermaseptin, respectively. Most Piplartine/dermaseptin combinations showed synergistic effect, with combination index (CI) values less than 0.9 when S. mansoni adults or schistosomula were simultaneously incubated with both drugs in vitro; synergy between these two compounds was also indicated using isobolograms. Additionally, we observed alterations on the tegumental surface of schistosomula and adult schistosomes by means of laser scanning confocal microscopy. Furthermore, egg laying of surviving worms was considerably more reduced when exposed to the piplartine/dermaseptin combinations than each drug alone, and this inhibition was irreversible. This is the first report on the synergistic effect between piplartine and dermaseptin against S. mansoni and opens the route to further studies (e.g. in vivo) to characterize this combination in greater detail.

Efeito da endogamia sobre características morfométricas em cavalosda raça Mangalarga Marchador / Effect of inbreeding on morfhometric traits in Mangalarga Marchador horses

Estimou-se o coeficiente de endogamia e avaliou-se seu efeito sobre características morfométricas dos animais em um criatório no norte de Minas Gerais. As características estudadas foram alturas da cernelha e da garupa, comprimentos da cabeça, do pescoço, do dorso-lombo, da garupa e do corpo, larguras do peito e da garupa. O arquivo continha 2186 informações de parentesco de animais do arquivo zootécnico da fazenda, desde o início da formação da raça, 1951, até o ano de 2006. Calculou-se o coeficiente de endogamia (F) e avaliou-se seu efeito por meio de regressão linear simples sobre as medidas morfométricas. Do total de animais, 27,6% mostraram-se endogâmicos, sendo o F médio da população igual a 1,4%. Considerando-se apenas os animais endogâmicos, a consanguinidade média atingiu 5,3%, mínimo de 0,1 e máximo de 28,1%. Não se verificaram efeitos negativos da endogamia sobre as características morfométricas, exceto para largura da garupa, em que se observou que para cada 10% de acréscimo de F houve aumento de 0,576cm na largura da garupa. Possivelmente, devido ao baixo valor encontrado, a endogamia não influenciou as demais características avaliadas.

The coefficient of inbreeding was estimate and its effect on linear traits of the Mangalarga Marchador horses reared in a ranch in the North of Minas Gerais was evaluated. The characteristics studied were morphometric traits such as wither and hip height, length of head, neck, back-loin, hip and body, as well as chest and hip width. The archive had 2186 data on the genealogy of animals from the herd register of the Catuni Farm. The coefficient of inbreeding (F) was calculated and its effect was evaluated by means of simple linear regression on the linear traits. Of all animals, 27.6% showed inbreeding, with an F average of 1.4% in the population. Considering only the inbred animals, the average consanguinity reached 5.3% minimum of 0.1 and maximum of 28.1%. Negative effects of inbreeding on the morphometric traits were not seen, except for hip width, where for each 10% increase in F there was increase of 0.576cm. Possibly due to the low value found, inbreeding did not influence the other evaluated characteristics.

Activity of epiisopiloturine against Schistosoma mansoni.

Schistosomiasis, caused by blood flukes of the genus Schistosoma, still imposes a considerable public health burden on large parts of the world. The control of this disease depends almost exclusively on the drug praziquantel, and there are no alternative drugs in sight. Natural compounds have recently attracted significant attention due to their relevance to parasitic infection and potential development into new therapeutic agents. Epiisopiloturine is an imidazole alkaloid isolated from the leaves of Pilocarpus microphyllus (Rutaceae), a native plant from Brazil. Here, we report the in vitro effect of this drug on the survival time of Schistosoma mansoni of different ages, such as 3 h old and 1, 3, 5, and 7 days old schistosomula, 49-day-old adults, and on egg output by adult worms. Epiisopiloturine at a concentration of 300 µg/mL caused the death of all schistosomula within 120 h. Extensive tegumental alterations and death were observed when adult schistosomes had been exposed to 150 µg/mL of the epiisopiloturine. At the highest sub-lethal dose of alkaloid (100 µg/mL), a 100% reduction in egg laying of paired adult worms was observed. Additionally, epiisopiloturine showed selective antischistosomal activity and exhibited no cytotoxicity to mammalian cells. This report provides the first evidence that epiisopiloturine is able to kill S. mansoni of different ages and inhibit worm egg laying.

Contribution of the cashew gum (Anacardium occidentale L.) for development of layer-by-layer films with potential application in nanobiomedical devices.

The search for bioactive molecules to be employed as recognition elements in biosensors has stimulated researchers to pore over the rich Brazilian biodiversity. In this sense, we introduce the use of natural cashew gum (Anacardium occidentale L.) as an active biomaterial to be used in the form of layer-by-layer films, in conjunction with phthalocyanines, which were tested as electrochemical sensors for dopamine detection. We investigated the effects of chemical composition of cashew gum from two different regions of Brazil (Piauí and Ceará states) on the physico-chemical characteristics of these nanostructures. The morphology of the nanostructures containing cashew gum was studied by atomic force microscopy which indicates that smooth films punctuated by globular features were formed that showed low roughness values. The results indicate that, independent of the origin, cashew gum stands out as an excellent film forming material with potential application in nanobiomedical devices as electrochemical sensors.

Gastroprotective activity of Zanthoxylum rhoifolium Lam. in animal models.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem barks of Zanthoxylum rhoifolium Lam. (Rutaceae), locally known as "mamica de cadela", are popularly used in dyspepsies, stomachic, tonic, antitumoral, antipyretic and are used in treating flatulence and colic. The objective of this study was to evaluate the gastroprotective effect of the ethanolic extract of Zanthoxylum rhoifolium (EEZR) stem barks in acute gastric lesion models, investigating their possible mechanisms. MATERIALS AND METHODS: Mice were used for the evaluation of the acute toxicity, and mice and rats to study the gastroprotective activity. The gastroprotective action of EEZR was analyzed in the absolute ethanol, HCl/ethanol and indomethacin-induced gastric lesion models in mice, hypothermic-restraint stress, and ischemia/reperfusion in rats. In the investigation of the gastroprotective mechanisms of EEZR, the participation of the NO-synthase pathway, ATP-sensitive potassium channels (K(ATP)), the levels of the non-protein sulfhydril groups (NP-SH) and the catalase activity using the ethanol-induced gastric mucosa lesion model and the quantification of the gastric mucus and the antisecretory activity through pylorus ligature model in rats were analyzed. RESULTS: The animals did not present any signs of acute toxicity for the EEZR (up to the 4 g/kg dose, po), and it was not possible to calculate the DL(50). EEZR (125-500 mg/kg) exhibited a significant gastroprotective effect in absolute ethanol, HCl/ethanol, hypothermic-restraint stress, and ischemia/reperfusion-induced gastric lesion models. EEZR (250 and 500 mg/kg) exhibited still a gastroprotective activity in the indomethacin-induced ulcer model. Gastroprotection of EEZR was significantly decreased in pre-treated mice with l-NAME or glibenclamide, the respective nitric oxide synthase and K(ATP) channels inhibitors. Our studies revealed that EEZR (500 mg/kg) prevented the decrease of the non-protein sulfhydril groups (NP-SH) and increased the catalase levels in ethanol-treated animals. Furthermore, the extract (500 mg/kg) significantly increased the mucus production, however, the gastric secretion parameters (volume, [H(+)], pH) did not show any alteration. CONCLUSIONS: Our results indicate that the ethanolic extract of Zanthoxylum rhoifolium exhibits a significant gastroprotection, because it inhibits the formation of gastric lesions using different models. The release of the nitric oxide, the opening of the K(ATP) channels, the participation of the non-protein sulfhydril groups (NP-SH), catalase and the increase of mucous secretion seem to be involved in the gastroprotection activity of the EEZR. Nevertheless, this activity does not seem to be related to antisecretory mechanisms.

Time delays in the synchronization of chaotic coupled lasers with feedback.

Isochrony and time leadership was studied in the synchronized excitable behavior of coupled chaotic diode lasers. Each unit of the system had chaos due to feedback with a fixed delay time. The inter-units coupling signal had a second, independent, characteristic time. Synchronized excitable spikes present isochronous, time leading or time lagging behavior whose stability is shown to depend on a simple relation between the feedback and the coupling times. Experiments on the synchronized low frequency fluctuations of two optically coupled semiconductor lasers and numerical calculations with coupled laser equations verify the predicted stability conditions for synchronization. Synchronism with intermittent time leadership exchange was also observed and characterized.

Experimental bifurcations and homoclinic chaos in a laser with a saturable absorber.

The shape and the peak values of the pulses from a passive Q-switching CO2 laser with SF6 as saturable absorber were detected while the laser was tuned in frequency across a longitudinal mode. A succession of stability windows, typical for bifurcation diagrams in the homoclinic scenario, was observed and the widths of those windows were measured. The expansion rate of the undulations in individual pulses was also obtained and compared to Floquet's multipliers given by the ratio of widths in consecutive windows. The dynamics is consistent with a homoclinic tangency to a periodic orbit.

Coarse grained variables and deterministic chaos in an excitable system.

Temporal coarse graining was applied to the dynamical variables of a semiconductor laser with optical feedback. The chaotic low frequency fluctuations obtained in numerical and experimental data are shown to have properties of a self-excitable deterministic system. External exciting noise is replaced by the ultrafast chaotic oscillations of the system. A low dimensional coarse-grained phase space is defined and time constants are introduced and measured for the exponential drop and recovery of the randomly excited equally shaped spikes.