Preclinical toxicity of innovative molecules: In vitro, in vivo and metabolism prediction.

The lack of predictivity of animal's models has increased the failure rate of drug candidates. Thus, the reversion of this scenario using preliminary in vitro assays and metabolism prediction can reduce the unnecessary use of animals, as well as predict toxic effects at preclinical and clinical stages. The present study aimed to evaluate safety of four biologically active molecules (RN104, RI78, ICH, PCH) with potential therapeutic applications synthesized in our laboratory. Initially, we used MTT cytotoxicity against A549, H9C2, HepG2, LLC-PK1 and NEURO-2 cell lines. RN104 showed the lowest cytotoxicity and further studies were conducted with it. The neutral red (NR) test was performed according to OECD-129 and then acute toxicity test (OECD-423). According to NR results we administered at 300 mg/kg on animals; however, no toxic effect was observed, while 2,000 mg/kg resulted in the death of one animal per group. After, metabolism prediction studies, performed using both ligand-based and structure-based, suggests three potential metabolites. In silico results suggested that potential metabolites could be fast eliminated and, then, this could be an explanation for lower observed toxicity in in vivo experiments. The results showed limitations of the NR as a predictor of the initial dose for the acute toxicity study, which may be related to metabolism. Therefore, the combination of theoretical and experimental studies is relevant to a general understanding of new molecule's toxicity.

Neuroimaging Findings of Zika Virus-Associated Neurologic Complications in Adults.

When the first suspected cases of neurologic disorders associated with the Zika virus were noticed in Brazil in late 2015, several studies had been conducted to understand the pathophysiology of the disease and its associated complications. In addition to its well-established association with microcephaly in neonates, the Zika virus infection has also been suggested to trigger other severe neurologic complications in adults, such as Guillain-Barré syndrome, radiculomyelitis, and meningoencephalitis. Hence, the Zika virus should be deemed a global threat that can cause devastating neurologic complications among individuals in all age ranges. The aim of this review was to further describe neuroimaging findings of Zika virus infection and associated neurologic complications found in adults.

Neurologic complications of acute environmental injuries.

Environmental injuries can result in serious neurologic morbidity. This chapter reviews neurologic complications of thermal burns, smoke inhalation, lightning strikes, electric injury, near drowning, decompression illness, as well as heat stroke and accidental hypothermia. Knowing the pathophysiology and clinical presentation of such injuries is essential to proper management of primary and secondary medical complications. This chapter highlights the most frequently encountered neurologic injuries secondary to common environmental hazards, divided into the topics: injuries related to fire, electricity, water, and the extremes of temperature.

Continuous versus group sequential analysis for post-market drug and vaccine safety surveillance.

The use of sequential statistical analysis for post-market drug safety surveillance is quickly emerging. Both continuous and group sequential analysis have been used, but consensus is lacking as to when to use which approach. We compare the statistical performance of continuous and group sequential analysis in terms of type I error probability; statistical power; expected time to signal when the null hypothesis is rejected; and the sample size required to end surveillance without rejecting the null. We present a mathematical proposition to show that for any group sequential design there always exists a continuous sequential design that is uniformly better. As a consequence, it is shown that more frequent testing is always better. Additionally, for a Poisson based probability model and a flat rejection boundary in terms of the log likelihood ratio, we compare the performance of various continuous and group sequential designs. Using exact calculations, we found that, for the parameter settings used, there is always a continuous design with shorter expected time to signal than the best group design. The two key conclusions from this article are (i) that any post-market safety surveillance system should attempt to obtain data as frequently as possible, and (ii) that sequential testing should always be performed when new data arrives without deliberately waiting for additional data.

Toxicidade reprodutiva do extrato hidroalcóolico de Samanea tubulosa Benth em ratas wistar / Reproductive toxicity study in Wistar rats treated with hydroalcoholic extract of the pods of bordão-de-velho (Samanea tubulosa Benth)

RESUMOO objetivo deste trabalho foi avaliar possíveis efeitos do extrato das vargens de bordão-de-velho (Samanea tubulosa benth) sobre a reprodução em ratas Wistar. O extrato foi preparado a partir da secagem e trituração das vagens, seguida por maceração com etanol e, posteriormente, concentrado em rotavapor. Ratas Wistar gestantes foram tratadas com 75 mg.100 g-1 de peso corporal de extrato de S. tubulosa e o grupo controle recebeu 1ml/100 g-1 de peso corporal de solução salina por gavagem durante 19 dias. Após eutanásia no 20º dia, as seguintes variáveis foram analisadas: peso corporal fetal, peso dos fetos e placentas, número de corpos lúteos e de reabsorções, implantação, fetos vivos e mortos. O extrato de vagens de S. tubulosa apresenta toxicidade para o feto causando malformações, reabsorções fetais e diminuição pronunciada do peso ao nascer. Contudo, o extrato de vagens de S. tubulosanão influencia no número de corpos lúteos e número de implantações.

ABSTRACTThe aim of this study was to evaluate possible effects of pods from bordão-de-velho (Samanea tubulosa benth) extract on the reproduction of female rats.The extract was prepared by maceration wtith ethanol of dried and crushed pods, then it was concentrated in rotary evaporator. The pregnant Wistar rats were treated with a dose of 75 mg.100 g-1of body weight of Samanea tubulosa extract, by gavage , whereas the control group received 1ml.100g-1of saline by the same route for 19 days. After the euthanasia of the animals at day 20th,the following variables were analyzed: fetal body weight, weight of fetuses and placentas, number of corpora lutea, resorption points, live and dead fetuses and number of embryonic implantations. The extract from S. tubulosa pods, at the dose studied, showed toxicity causing fetal abnormalities, fetal resorption and pronounced decrease in the weight of offspring at birth. On the other hand, , the treatment with extract of S.tubulosa pods had no influence over corpora lutea and implantation numbers.

Avaliação da qualidade e equivalência farmacêutica de comprimidos contendo 10mg de sinvastatina / Assessment of quality and pharmaceutical equivalence of 10 mg simvastatin tablets

A sinvastatina, pertencente à classe das estatinas, é um importante fármaco redutor do colesterol e é encontrada comercialmente como medicamentos referência, genéricos e similares em diferentes dosagens, sendo a de 10 mg a mais comum. Este trabalho tem como objetivo avaliar a qualidade e a equivalência entre comprimidos de sinvastatina 10 mg comercializados no mercado brasileiro. Foram selecionados dois medicamentos similares, um genérico e referência. Os ensaios de controle de qualidade aplicados foram: determinação do peso médio, dureza, friabilidade, desintegração, teor de princípio ativo, uniformidade de conteúdo e dissolução in vitro. Para tanto, foi necessário desenvolvimento e validação de metodologia por espectrofotometria na região do ultravioleta (UV). As formulações apresentaram-se dentro dos limites preconizados para todas as análises. No entanto, quando analisou-se estatisticamente os perfis de dissolução, verificou-se a não equivalência entre os medicamentos similares e o de referência. Porém, através dos resultados obtidos, podemos evidenciar a equivalência entre o genérico e o de referência, sugerindo sua intercambialidade...

Simvastatin, a well-known medicine of the statin class, is used therapeutically for the reduction of cholesterol and is commercially available in reference, similar and generic forms, in various doses, the tablet of 10 mg being the commonest in prescriptions. The purpose of this study was to test the quality and the pharmaceutical equivalence of tablets containing 10 mg of simvastatin available on the Brazilian market. One generic, one reference and two similar dosage forms were selected. The quality-control variables used were: weight variation, hardness, friability, disintegration, content of the active principle, content uniformity and dissolution in vitro. A UV-spectrophotometric method was developed and validated. All formulations were approved in the quality analysis. By using mathematical and statistical models, it was observed that the dissolution profiles of the similar dosage forms were not equivalent to that of the reference. On the other hand, when the generic medicine was compared with the reference, their interchangeability was confirmed...

Apéndices testicular y epididimario en individuos brasileños / Testicular and epididymal appendices in Brazilian individuals

Los apéndices testiculares y epididimarios son remanescentes embriológicos del conducto paramesonéfrico y del conducto mesonéfrico, respectivamente. Estos apéndices pueden sufrir torsión causando un cuadro conocido como escroto agudo. El presente trabajo tuvo como objetivo determinar las variaciones de los apéndices testicular y epididimario, registrando su forma y tamaño. Se utilizaron 30 cadáveres de indivíduos adultos, Brasileños, con edades comprendidas entre 18 y 70 años, fijados en formaldehído 40%, facilitados por el Laboratorio de Anatomía Descriptiva y Topográfica de la Universidad Federal de Alagoas (UFAL), Maceió, Brasil. A través de disección se identificó la presencia de los respectivos apéndices, los que fueron medidos con un caliper manual (MetricaR), registrando su longitud y anchura. Los apéndices testiculares fueron observados en 41 testículos (68,3%) y los apéndices epididimarios en 15 casos (25%). El promedio de la longitud fue de 4,9 mm (DE=1,7) para el apéndice testicular y de 5,2 mm (DE=2,4) para el epididimario. Con respecto a la anchura de los apéndices, el promedio registrado fue de 3,2 mm (DE=1,7) para el testicular y de 2,6 mm (DE=0,9) para el epididimario. Los datos obtenidos puede ser utlizados como soporte morfológico a la clínica urológica y cirugía testicular.

Testicular and epididymal appendages are embryologic remnants of the mesonephric duct and paramesonephric, respectively. These appendices are subject to a torsion causing condition known as acute scrotal syndrome. This study aimed to determine the variations of testicular and epididymal appendices, registering its presence and size. We studied 30 cadavers of adult individuals, Brazilians, aged 18 and 70, fixed in formaldehyde 40%, provided by the Laboratory of Descriptive and Topographic Anatomy of the Federal University of Alagoas (UFAL), Maceió, Brazil. By dissecting these, the presence of the respective appendixes were identified, which were measured with a manual caliper (Metrica), recording its length and width. The testicular appendices were observed in 41 testes (68.3%) and epididymal appendices in 15 cases (25%). The average length was 4.9 mm (SD=1.7) for the appendix testis and epididymis to 5.2 mm (SD=2.4). With respect to the width of the appendices, the average recorded were 3.2 mm (SD=1.7) and 2.6 mm (SD=0.9) for testicular and epididymal, respectively. The data obtained can be used as morphological support in urological clinical and testicular surgery.

Apoptosis in alpha interferon (IFN-alpha) intratumoral chemotherapy for cystic craniopharyngiomas.

OBJECTIVES: The aim of this study was to verify whether intracystic injections of alpha-Interferon (IFN-alpha) in cystic craniopharyngiomas were able to reduce the tumor by activating the Fas apoptotic pathway. MATERIALS AND METHODS: Twenty-one patients with cystic craniopharyngiomas treated at the Pediatric Oncology Institute (IOP/GRAACC) of Federal University of São Paulo were submitted to intracystic chemotherapy with IFN-alpha. The tumor sizes of all patients were monitored and the apoptotic factor soluble FasL (sFasL) concentration was determined by ELISA (enzyme-linked immunosorbent assay) in tumor fluid samples from eight patients. RESULTS: There was a complete reduction in 11 patients, a partial response in seven, and a minor response in three patients. The concentration of sFasL was increased in all the eight patients examined concomitantly with the tumor size reduction. CONCLUSIONS: Our data demonstrated that the IFN-alpha was able to induce Fas-mediated apoptosis together with a reduction in the tumor size; such an observation may suggest the importance to investigate still unexplored mechanisms to be exploited in craniopharyngioma therapy.

Responses of eucalypt species to aluminum: the possible involvement of low molecular weight organic acids in the Al tolerance mechanism.

Aluminum (Al) tolerance mechanisms in crop plants have been extensively researched, but our understanding of the physiological mechanisms underlying Al tolerance in trees is still limited. To investigate Al tolerance in eucalypts, seedlings of six species (Eucalyptus globulus Labill., Eucalyptus urophylla S.T. Blake, Eucalyptus dunnii Maiden, Eucalyptus saligna Sm., Eucalyptus cloeziana F. J. Muell. and Eucalyptus grandis w. Hill ex Maiden) and seedlings of six clones of Eucalyptus species were grown for 10 days in nutrient solutions containing Al concentrations varying from 0 to 2.5 microM (0 to 648 microM Al3+ activities). Root elongation of most species was inhibited only by high Al3+ activities. Low to intermediate Al3+ activities were beneficial to root elongation of all species and clones. Among the species tested, E. globulus and E. urophylla were more tolerant to Al toxicity, whereas E. grandis and E. cloeziana were more susceptible to Al-induced damage. Although E. globulus seedlings were tolerant to Al toxicity, they were highly sensitive to lanthanum (La), indicating that the tolerance mechanism is specific for Al. Fine roots accumulated more Al and their elongation was inhibited more than that of thick roots. In E. globulus, accumulation of Al in root tips increased linearly with increasing Al concentration in the nutrient solution. The majority of Al taken up was retained in the root system, and the small amounts of Al translocated to the shoot system were found mainly in older leaves. No more than 60% of the Al in the thick root tip was in an exchangeable form in the apoplast that could be removed by sequential citrate rinses. Gas chromatography/mass spectrometry and ion chromatography analyses indicated that root exposure to Al led to a greater than 200% increase in malic acid concentration in the root tips of all eucalypt species. The increase in malate concentration in response to Al treatment correlated with the degree of Al tolerance of the species. A small increase in citric acid concentration was also observed in all species, but there were no consistent changes in the concentrations of other organic acids in response to Al treatment. In all eucalypt species, Al treatment induced the secretion of citric and malic acid in root exudates, but no trend with respect to Al tolerance was observed. Thus, although malate and citrate exudation by roots may partially account for the overall high Al tolerance of these eucalypt species, it appears that tolerance is mainly derived from the internal detoxification of Al by complexation with malic acid.

Hepatitis B infection among patients attending a sexually transmitted diseases clinic in Rio de Janeiro, Brazil.

Hepatitis B virus (HBV) has a low endemicity in Rio de Janeiro, Brazil. Sexual transmission must play an important role in this virus, but the prevalence and risk factors have never been properly investigated. The aim of this paper is to determine the prevalence and risk factors for HBV infection in patients attending a Sexually Transmitted Diseases Clinic of the Universidade Federal Fluminense, from the State of Rio de Janeiro, Brazil. In a retrospective study, HBV seroprevalence was investigated in 440 patients. Serum of each patient was assayed for antibodies against hepatitis B core antigen (anti-HBc), hepatitis B surface antigen (HBsAg) and antibodies against hepatitis B surface antigen (anti-HBs). Demographic and risk factor data were extracted from clinic notes. The overall seroprevalence of exposure markers for HBV (anti-HBc, HBsAg and anti-HBs) were 13%, 3.4% and 8.5% respectively. Homo/bisexual behaviour, anal intercourse, HIV infection, positive serology for syphilis and blood transfusion were predictors of the HBV exposure. Among demographic data, age and place of birth were associated with the anti-HBc seropositivity.

Magnesium is more efficient than calcium in alleviating aluminum rhizotoxicity in soybean and its ameliorative effect is not explained by the Gouy-Chapman-Stern model.

The mechanistic basis for cation amelioration of Al rhizotoxicity in soybean was investigated through a series of studies comparing protective effects of Ca and Mg against Al inhibition of root elongation in a background 0.8 mM CaSO4 solution (pH 4.3). A modified Gouy-Chapman-Stern model was used to evaluate the effect of cations on electrical potential and Al3+ activity at root plasma membrane surfaces. Activities of Al3+ up to 4.6 microM in the background solution inhibited soybean tap root elongation by more than 80%. There was little or no response in root elongation when Ca and Mg were added to background solutions in the absence of AL: When added to Al-toxic solutions in the micromolar concentration range, Mg was 100-fold more effective than Ca in alleviating Al toxicity, whereas both cations were equally effective when added in the millimolar concentration range. The protective effect of micromolar additions of Mg on root elongation was specific for Al and it failed to alleviate La rhizotoxicity. In contrast to wheat, Mg amelioration of Al toxicity to soybean root elongation at low Mg concentration could not be explained by changes in potential and Al3+ activity at the root plasma membrane surfaces as predicted by a Gouy-Chapman-Stern model. These results suggest that Mg is not acting as an indifferent cation when present at low concentration and implies the involvement of a mechanism other than pure electrostatic effects at the root surface.

Magnesium ameliorates aluminum rhizotoxicity in soybean by increasing citric acid production and exudation by roots.

Superior effectiveness of Mg over Ca in alleviating Al rhizotoxicity cannot be accounted for by predicted changes in plasma membrane Al3+ activity. The influence of Ca and Mg on the production and secretion of citrate and malate, and on Al accumulation by roots was investigated with soybean genotypes Young and PI 416937 which differ in Al tolerance. In the presence of a solution Al3+ activity of 4.6 microM, citrate and malate concentrations of tap root tips of both genotypes increased with additions of either Ca up to 3 mM or Mg up to 50 microM. Citrate efflux rate from roots exposed to Al was only enhanced with Mg additions and exceeded malate efflux rates by as much as 50-fold. Maximum citrate release occurred within 12 h after adding Mg to solution treatments. Adding 50 microM Mg to 0.8 mM CaSO4 solutions containing Al3+ activities up to 4.6 microM increased citrate concentration of tap root tips by 3- to 5-fold and root exudation of citrate by 6- to 9-fold. Plants treated with either 50 microM Mg or 3 mM Ca had similar reductions in Al accumulation at tap root tips, which coincided with the respective ability of these ions to relieve Al rhizotoxicity. Amelioration of Al inhibition of soybean root elongation by low concentrations of Mg in solution involved Mg-stimulated production and efflux of citrate by roots.

Aluminum accumulation at nuclei of cells in the root tip. Fluorescence detection using lumogallion and confocal laser scanning microscopy.

The mechanistic basis for Al toxicity effects on root growth is still a matter of speculation, but it almost certainly involves decreased cell division at the root apex. In this series of experiments, we attempt to determine whether Al enters meristematic cells and binds to nuclei when roots are exposed to a low Al(3+) activity in solution. The methodology involved the use of the Al-sensitive stain lumogallion (3-[2,4 dihydroxyphenylazo]-2-hydroxy-5-chlorobenzene sulfonic acid), the DNA stain 4',6-diamino-phenylindole, and confocal laser scanning microscopy. Soybean (Glycine max L. Merr.) cv Young (Al-sensitive) and PI 416937 (Al-tolerant) genotypes were exposed to 1.45 microM Al(3+) for periods ranging from 30 min to 72 h, and then washed with 10 mM citrate to remove apoplastic Al. Fluorescence images show that within 30 min Al entered cells of the sensitive genotype and accumulated at nuclei in the meristematic region of the root tip. Substantial Al also was present at the cell periphery. The images indicated that the Al-tolerant genotype accumulated lower amounts of Al in meristematic and differentiating cells of the root tip and their cell walls. Collectively, the results support an important role for exclusion in Al tolerance.