Random regression models for the estimation of genetic and environmental covariance functions for growth traits in Santa Ines sheep.

Polynomial functions of different orders were used to model random effects associated with weight of Santa Ines sheep from birth to 196 days. Fixed effects included in the models were contemporary groups, age of ewe at lambing, and fourth-order Legendre polynomials for age to represent the average growth curve. In the random part, functions of different orders were included to model variances associated with direct additive and maternal genetic effects and with permanent environmental effects of the animal and mother. Residual variance was fitted by a sixth-order ordinary polynomial for age. The higher the order of the functions, the better the model fit the data. According to the Akaike information criterion and likelihood ratio test, a continuous function of order, five, five, seven, and three for direct additive genetic, maternal genetic, animal permanent environmental, and maternal permanent environmental effects (k = 5573), respectively, was sufficient to model changes in (co)variances with age. However, a more parsimonious model of order three, three, five, and three (k = 3353) was suggested based on Schwarz's Bayesian information criterion for the same effects. Since it was a more flexible model, model k = 5573 provided inconsistent genetic parameter estimates when compared to the biologically expected result. Predicted breeding values obtained with models k = 3353 and k = 5573 differed, especially at young ages. Model k = 3353 adequately fit changes in variances and covariances with time, and may be used to describe changes in variances with age in the Santa Ines sheep studied.

Can Spirulina maxima reduce the mutagenic potential of sibutramine?

The worldwide obesity pandemic requires the use of anti-obesity drugs. Sibutramine is an anti-obesity drug that has been used worldwide but is indiscriminately consumed in Brazil. Several studies have demonstrated that sibutramine promotes weight loss and weight maintenance, but several side effects have been associated with its systematic consumption. For this reason, sibutramine was withdrawn from the European and American markets, but still remains legal for use in Brazil. Studies have shown that a 5-10% reduction in body weight results in outstanding health benefits for obese patients. However, in order to promote significant weight loss, it is necessary to use sibutramine for at least 2 years. This long-term exposure has carcinogenic potential, as sibutramine causes DNA damage. Thus, this study evaluated the in vivo mutagenic potential of sibutramine alone (5, 7, 10, 15, and 20 mg/kg) and in association with Spirulina maxima (150 and 300 mg/kg), a cyanobacterium with antioxidant potential, using the polychromatic erythrocyte micronucleus test. Our results reinforced the mutagenic potential of sibutramine alone, which showed a time-dependent action. Combinatory treatments with S. maxima were not able to reduce the genotoxicity of sibutramine. These results were confirmed in vitro with the cytokinesis-blocked micronucleus test. In conclusion, our data showed that new alternative anti-obesity treatments are needed since the consumption of sibutramine can increase the risk of cancer in overweight patients.

Investigation of genetic susceptibility to Mycobacterium tuberculosis (VDR and IL10 genes) in a population with a high level of substructure in the Brazilian Amazon region.

OBJECTIVES: Tuberculosis (TB) is an infectious and contagious disease that has been very influential in human history and presents high rates of mortality. The objective of this study was to investigate the association of VDR, IL10, and SLC11A1 gene polymorphisms with susceptibility to the presence of Mycobacterium tuberculosis infection. METHODS: A total of 135 patients with confirmed TB and 141 healthy individuals were included in the analysis. Blood samples were collected for DNA extraction. Genotyping of the polymorphisms in the VDR and IL10 genes was performed by real-time PCR, and genotyping of the polymorphisms in the SLC11A1 gene by conventional PCR, followed by visualization in polyacrylamide gel. The genomic ancestry was obtained using an autosomal panel with 48 insertion/deletion ancestry-informative markers. RESULTS: Polymorphisms TaqI (TT, p=0.004), FokI (CC and CC+CT, p=0.012 and p=0.003, respectively), and BsmI (GG, p=0.008) in the VDR gene, as well as A-592C (GC+AG, p=0.001) in the IL10 gene, were significantly associated with susceptibility to TB In addition, high production of VDR combined with low production of IL10 showed protection for the TB group (p=0.035). CONCLUSIONS: The VDR polymorphisms may confer an increased risk and the IL10 haplotype may be a protection factor for the presence of M. tuberculosis infection in the Brazilian population.

Teratogenic Effect of Usnic Acid from Cladonia substellata Vainio during Organogenesis.

Studies about toxicological potential of usnic acid are limited. This way, the vast majority of data available in the literature are related only to biological activities. This is the first study that aimed to evaluate the oral toxicity of usnic acid during the period of organogenesis. Females rats were distributed in the control groups, treated I and II, at doses of 15 and 25 mg/kg, administered by gavage during the 6° to 15° days of pregnancy. After 20 days the fetuses were removed and analyzed. A reduction in weight gain during pregnancy, increased resorption, reduction in the number of viable fetuses, and their body weight were observed. Morphological changes in the litter were visualized as exposure of the eye and atrophy of the limbs at the dose of 25 mg/kg. Histological analysis of the liver of the fetus showed reduction in the number of megakaryocytes between experimental groups and increase in the number of hepatocytes in a dose of 25 mg/kg. The experimental model used in this study reveals teratogenic effect of usnic acid in the period of organogenesis. Since this achievement, the importance of evaluating the toxic effects of natural substances is imperative, in order to elucidate the care in their indication as drug.

Prevalence of deltaF508, G551D, G542X, and R553X mutations among cystic fibrosis patients in the North of Brazil.

Cystic fibrosis (CF) is the most common genetic disease among Caucasians and is rare among sub-Saharan Africans. The Brazilian population is not ethnically homogeneous but it is the result of three-way ethnic admixture of Europeans, Africans and Amerindians in varying proportions, depending on the region. In the present study, we investigated 33 patients who had been diagnosed and are currently under treatment for CF at the University Hospital João de Barros Barreto, Belém, Pará State. The molecular analysis for G542X, G551D and R553X mutations was performed by PCR followed by RFLP using BstNI, HincII and MboI, respectively, in polyacrylamide gel eletrophoresis and stained with AgNO3. ThedeltaF508 mutation (a deletion of 3 bp) was only analyzed by polyacrylamide gel electrophoresis and stained with AgNO3. Each sample was analyzed for regions of interest in the CFTR gene using amplified by PCR and specific primers. The deltaF508 and G551D mutations presented frequencies of 22.7 and 3%, respectively. In 74.3% of the remaining patients, none of the mutations investigated was found. The present study characterized in a sample of patients with an established clinical diagnosis of CF (asthma, repeated bronchopneumonia, disorders of nutritional status, etc.) the most frequent mutation (deltaF508) in the North region of Brazil and is also the first report of the G551D mutation. In spite of the wide spectrum of CF mutations and the heterogeneous ethnic origin of the Amazon population, the molecular diagnosis is a helpful additional tool for the diagnosis and treatment of CF patients.

Retinohypothalamic projections in the common marmoset (Callithrix jacchus): A study using cholera toxin subunit B.

Retinal projections in vertebrates reach the primary visual, accessory optic, and circadian timing structures. The central feature of the circadian timing system is the principal circadian pacemaker, the suprachiasmatic nucleus (SCN) of the hypothalamus. The direct projections from the retina to the SCN are considered the entrainment pathway of the circadian timing system. In this study, unilateral intravitreal injections of cholera toxin subunit B were used to trace the retinal projections to the marmoset hypothalamus. The retinohypothalamic tract reaches the ventral suprachiasmatic nucleus bilaterally, as anticipated from previous studies. However, labeled fibers were found in several other hypothalamic regions, such as the medial and lateral preoptic areas, supraoptic nucleus, anterior and lateral hypothalamic areas, retrochiasmatic area, and subparaventricular zone. These results reveal new aspects of retinohypothalamic projection in primates and are discussed in terms of their implications for circadian as well as noncircadian control systems.

Correção de medida ultrassonográfica de carcaça em coelhos usando modelo linear misto com covariáveis / Correction ultrasonographic measurement of carcass in rabbits using mixed linear Model with covariates

Objetivou-se avaliar a correção da medida ultrassonográfica da área do músculo Longissimus dorsi, em coelhos da raça Nova Zelândia, pela análise de covariância usando modelos mistos. Foram realizadas análises em delineamento em blocos completos ao acaso, com cinco tratamentos (operadores) e seis blocos (animais), considerando na análise: a inexistência de covariáveis; a covariável comprimento de olho de lombo; a covariável profundidade de olho de lombo; e as duas covariáveis juntas. Como os animais são uma amostra aleatória, o efeito de bloco foi considerado como aleatório. Consideraram-se as covariáveis como medidas com efeito fixo sem erro, independentemente do tratamento e do comportamento linear. As estatísticas de critério de decisão CV%, R ² e R ¯ ² evidenciaram relação direta entre si e podem ser consideradas para avaliar a precisão experimental em ensaios com avaliação de carcaças. Os valores das estatísticas AIC, BIC e AICC apresentam coerência com a interpretação dos critérios de decisão e indicam que o modelo com duas covariáveis proporciona resultados acurados. A inclusão das covariáveis complementa o controle de local com melhoria na precisão do experimento. A utilização das medidas ultrassonográficas de profundidade e comprimento corrige a média da área do músculo Longissimus dorsi avaliado por diferentes operadores.(AU)

The objective of this study was to evaluate the correction ultrasonographic measurement of area the Longissimus dorsi muscle in New Zealand rabbits by covariance analysis using mixed linear models. The analyzes were performed in randomized block design with 5 treatments (operators) and 6 blocks (animals), considering in the analysis: absence of covariates; rib eye length as covariate; rib eye depth as covariate; the two covariates together. As the animals are a random sample, the block effect was considered to be random. The covariates were considered as measures of fixed effect without error, independent of treatment and linear comportment. The decision criterion statistics CV%, R², and R ¯ ²showed a direct relationship between them and can be taken into consideration to evaluate the experimental accuracy in tests with carcass evaluation. The AIC, BIC, and AICC statistics are consistent with the interpretation of the decision criteria and indicate that the two covariates in model provides accurate results. The inclusion of covariates complements the local control to improve the accuracy of the experiment. The use of ultrasound measurements of depth and length corrects the mean area of the Longissimus dorsi muscle evaluated by different operators.(AU)

Encapsulation of trans-dehydrocrotonin in liposomes: an enhancement of the antitumor activity.

The aim of this study was the encapsulation of trans-dehydrocrotonin (t-DCTN) and its inclusion complexes with hydropropyl-beta-cyclodextrin (HP-beta-CD) in liposomes to improve t-DCTN antitumor activity. The in vitro kinetic profiles of t-DCTN-loaded liposomes (LD) and t-DCTN:HP-beta-CD-loaded liposomes (LC) were evaluated using the dialysis technique. The antitumor activity of LD and LC were investigated against Sarcoma 180 in Swiss mice. Histopathological and hematological analyses were carried out. The amounts of t-DCTN and t-DCTN:HP-beta-CD inclusion complex encapsulated in liposomes were equivalent to 1 mg of t-DCTN. The encapsulation efficiencies of LD and LC were 95.0 +/- 3.8% and 91.1 +/- 5.6%, respectively. In relation to kinetics, the drug release profiles of t-DCTN are in substantial agreement with the Fickian model. The treatment of animals with LD and LC produced tumor inhibitions of 79.4 +/- 9.6% and 63.5 +/- 5.5%, respectively. The liposomal encapsulation of t-DCTN by entrapment in the phospholipid bilayer increased at twice the antitumor activity. Moreover, the liposomal formulations reduced the hepatotoxicity effect of the drug and no significant hematological toxicity was observed in the treated animals. However, the counting of platelets was slightly decreased. Thus, the results show that the development of liposomal formulations containing t-DCTN or t-DCTN:HP-beta-CD is an important advance for enabling this drug to be use in therapy.

N-acetyl transferase 2 and cytochrome P450 2E1 genes and isoniazid-induced hepatotoxicity in Brazilian patients.

SETTING: Isoniazid (INH) is related to the development of hepatotoxicity in some patients. OBJECTIVE: To investigate the role of N-acetyl transferase 2 (NAT2) and cytochrome P450 2E1 (CYP2E1) in the hepatotoxicity of patients treated with INH in an Amazonian Brazilian population. DESIGN: Patients undergoing anti-tuberculosis treatment were investigated. Hepatotoxicity was defined as an increase of more than three times the upper limit of normal in serum alanine aminotransferase levels after treatment. NAT2 genotypes were identified by sequencing, whereas CYP2E1 alleles were detected using polymerase chain reaction based methods. RESULTS: Of the 270 individuals included in the study, 18 (6.7%) developed drug-related hepatotoxicity. A high association was found between slow acetylators and hepatotoxicity, particularly with regard to allele *5. The adjusted risk of developing hepatotoxicity was significant in individuals carrying two slow acetylation alleles (P = 0.036, OR 3.05, 95%CI 1.07-8.64). In all of the CYP2E1 markers examined, wild homozygous genotypes were more prevalent in subjects with hepatotoxicity than in controls; however, the difference was not statistically significant. Joint evaluation of the genes revealed a high risk of developing hepatotoxicity in slow acetylators with CYP2E1 wild alleles (adjusted OR 4.26; 95%CI 1.47-12.37, P = 0.008). CONCLUSIONS: Large-scale screening for NAT2 and CYP2E1 genotypes can prove useful in predicting the risk of adverse effects.

Endothelial and inducible nitric oxide synthases in oocytes of cattle.

Nitric oxide (NO) is a chemical messenger generated by the activity of the nitric oxide synthases (NOS). The NOS/NO system appears to be involved in oocyte maturation, but there are few studies on gene expression and protein activity in oocytes of cattle. The present study aimed to investigate gene expression and protein activity of NOS in immature and in vitro matured oocytes of cattle. The influence of pre-maturation culture with butyrolactone I in NOS gene expression was also assessed. The following experiments were performed: (1) detection of the endothelial (eNOS) and inducible (iNOS) isoforms in the ovary by immunohistochemistry; (2) detection of eNOS and iNOS in the oocytes before and after in vitro maturation (IVM) by immunofluorescence; (3) eNOS and iNOS mRNA and protein in immature and in vitro matured oocytes, with or without pre-maturation, by real time PCR and Western blotting, respectively; and (4) NOS activity in immature and in vitro matured oocytes by NADPH-diaphorase. eNOS and iNOS were detected in oocytes within all follicle categories (primary, secondary and tertiary), and other compartments of the ovary and in the cytoplasm of immature and in vitro matured oocytes. Amount of mRNA for both isoforms decreased after IVM, but was maintained after pre-maturation culture. The NOS protein was detected in immature (pre-mature or not) and was still detected in similar amount after pre-maturation and maturation for both isoforms. NOS activity was detected only in part of the immature oocytes. In conclusion, isoforms of NOS (eNOS and iNOS) are present in oocytes of cattle from early folliculogenesis up to maturation; in vitro maturation influences amount of mRNA and NOS activity.

Aspectos ambientais e genéticos da prolificidade em caprinos utilizando modelos bayesianos de limiar e linear / Environmental and genetic aspects of litter size in goats using linear and threshold bayesian models

Foram estimados os componentes de variância e os parâmetros genéticos da característica prolificidade, utilizando-se inferência bayesiana sob modelo animal linear e de limiar. A prolificidade de cabras mestiças foi estudada com informações referentes ao período de oito anos consecutivos. As análises foram realizadas com cadeias de 500.000 ciclos. Considerou-se burn-in dos 15.000 valores iniciais, sendo tomados valores a cada 250 ciclos, para se obter a distribuição a posteriori com 1.940 amostras. Os efeitos do mês de cobrição e da ordem de parto e o efeito linear do peso à cobrição foram significativos. As herdabilidades foram de 0,03 e 0,18 para o modelo linear e o modelo de limiar, respectivamente. O uso do modelo de limiar mostrou-se adequado, produzindo estimativas superiores acerca dos parâmetros estimados.

Variance components and genetic parameters of the litter size trait, using Bayesian inference under linear and threshold animal model were estimated. The litter size of crossbred goats was studied with information regarding a period of eight consecutive years. Analyses were performed with 500,000 cycle chains. The burn-in of the 15,000 baseline values was considered and these were taken every 250 cycles to obtain a posteriori distribution with 1,940 effective samples. Statistical analyses showed that the effects of coverage month, delivery order and linear effect of weight on coverage were significant. The heritabilities were 0.03 and 0.18 for linear and threshold models respectively. The threshold model proved to be suitable, producing higher estimates regarding the estimated parameters.

Atividades antioxidante e antimicrobiana dos extratos de própolis e açaí (Euterpe oleracea mart) / Antioxidant and antimicrobial activities of propolis and açai (Euterpe oleracea Mart) extracts

A própolis é uma resina natural que apresenta diversas ações biológicas devido a presença de fenólicos, especialmente flavonóides, em sua composição. O fruto do açaí (Euterpe oleracea Mart) é fonte de antocianinas, que também pertencem ao grupo dos flavonóides. O objetivo deste estudo foi avaliar o efeito antioxidante e antimicrobiano dos extratos de açaí e propolis em associação. A atividade antimicrobiana foi avaliada por ensaio em caldo enriquecido e a atividade antioxidante foi avaliada pelo método do sequestro de radicais DPPH. Os resultados mostraram que o extrato de própolis em pequenas concentrações apresentou atividade sobre o crescimento de S. aureus e S. epidermidis, e que ambos os extratos apresentaram atividade antioxidante. Foi possível concluir que ocorreu sinergismo entre os extratos de própolis e de açaí em relação à atividade antioxidante, bem como esta associação poderá apresentar atividade antimicrobiana caso o extrato de própolis seja utilizado em quantidade suficiente na formulação. Assim, esses extratos podem ser usados em formulações para uso tópico para prevenir o envelhecimento da pele e, possivelmente, transtornos causados pelos microrganismos empregados no estudo.

Propolis is a natural resin, collected mainly by the honey bee, Apis mellifera, which has been shown to have many biological roles, including antioxidant and antimicrobial effects, both conferred by phenolic compounds, especially flavonoids. The fruit of the açai palm is an important source of anthocyanins, which are also phenolics of the flavonoid group. The aim of this study was to assess the antioxidant and antimicrobial effects of a mixture of propolis and açai extracts. Antimicrobial activity was assessed by BHI broth culture with diluted extract, followed by agar subculture, while antioxidant activity was assessed by the DPPH radical scavenging assay. The results showed that around 2% of the propolis extract showed antimicrobial activity against Staphylococcus aureus and S. epidermidis, while low concentrations of both the ethanolic propolis and aqueous açai extracts, alone and combined, exhibited antioxidant activity. In conclusion, this study showed that the antioxidant effects of propolis and açai were summed in the mixed extracts. Furthermore, this combination would show antimicrobial activity if the minimum inhibitory concentration of propolis extract established in this study were used in the formulation. Hence, these extracts could be mixed into formulations used topically to prevent skin aging and, possibly, disorders caused by microbes, such as acne.

Stratum adiposum, a special structure of the African Catfish skin (Clarias gariepinus, Burchell 1822).

The skin histology of Clarias gariepinus, a scaleless teleost from south central Africa, is described. The African catfish epidermis is composed of epithelial cells representing 62.3% of volumetric density (Vv), club cells (Vv = 25.7%), mucous cells (Vv = 10.5%) and melanocytes (Vv = 1.4%). Its thickness amounts to approximately 240 microm. The dermis is distinguished by two well differentiated layers, the stratum adiposum, containing prominent amounts of adipose tissue, which forms large, oblong compartments circumscribed by dense connective tissue, and the stratum compactum, which is rich in compacted collagen fibres. Compared with other catfish species the dermis thickness is considerably thicker ranging from 1.3 to 2.3 mm. The function of this type of skin is discussed.

In vitro and in vivo properties of usnic acid encapsulated into PLGA-microspheres.

Microparticles will probably play a promising role in the future of chemotherapy. These polymeric delivery systems are capable of maximizing the therapeutic activity while reducing side effects of anti-cancer agents. Usnic acid (UA) is a secondary metabolite produced by lichens, which exhibits an anti-tumour activity. In this study, PLGA-microspheres containing usnic acid from Cladonia substellata were prepared by the double emulsion method, with or without PEG as stabilizer. The morphology of the microspheres was examined by optical and scanning electron microscopy. The in vitro kinetic profile of usnic acid loaded-microspheres was carried out by dissolution testing. The usnic acid content was analysed by HPLC. The cytotoxicity of free and encapsulated usnic acid was evaluated against HEp-2 cells using the MTT method. The anti-tumour assay was performed in mice against Sarcoma-180 tumour (UA 15 mg kg(-1) weight body/day) during 7 days. Animals were then sacrificed and tumour and organs were excised for histopathological analysis. Microspheres presented a smooth spherical surface with a mean diameter of 7.02 +/- 2.72 microm. The usnic acid encapsulation efficiency was approximately 100% (UA 10 mg 460 mg(-1) microspheres). A maximum release of 92% was achieved at the fifth day. The IC50 values for free and encapsulated usnic acid were 12 and 14 microg ml(-1), respectively. The encapsulation of usnic acid into microspheres promoted an increase of 21% in the tumour inhibition as compared with the free usnic acid treatment. In summary, usnic acid was efficiently encapsulated into PLGA-microspheres and the microencapsulation improved its anti-tumour activity.

Prevalence of deltaF508, G551D, G542X, and R553X mutations among cystic fibrosis patients in the North of Brazil

Cystic fibrosis (CF) is the most common genetic disease among Caucasians and is rare among sub-Saharan Africans. The Brazilian population is not ethnically homogeneous but it is the result of three-way ethnic admixture of Europeans, Africans and Amerindians in varying proportions, depending on the region. In the present study, we investigated 33 patients who had been diagnosed and are currently under treatment for CF at the University Hospital João de Barros Barreto, Belém, Pará State. The molecular analysis for G542X, G551D and R553X mutations was performed by PCR followed by RFLP using BstNI, HincII and MboI, respectively, in polyacrylamide gel eletrophoresis and stained with AgNO3. ThedeltaF508 mutation (a deletion of 3 bp) was only analyzed by polyacrylamide gel electrophoresis and stained with AgNO3. Each sample was analyzed for regions of interest in the CFTR gene using amplified by PCR and specific primers. The deltaF508 and G551D mutations presented frequencies of 22.7 and 3 percent, respectively. In 74.3 percent of the remaining patients, none of the mutations investigated was found. The present study characterized in a sample of patients with an established clinical diagnosis of CF (asthma, repeated bronchopneumonia, disorders of nutritional status, etc.) the most frequent mutation ( deltaF508) in the North region of Brazil and is also the first report of the G551D mutation. In spite of the wide spectrum of CF mutations and the heterogeneous ethnic origin of the Amazon population, the molecular diagnosis is a helpful additional tool for the diagnosis and treatment of CF patients.