Characterisation and prion transmission study in mice with genetic reduction of sporadic Creutzfeldt-Jakob disease risk gene Stx6.

Sporadic Creutzfeldt-Jakob disease (sCJD), the most common human prion disease, is thought to occur when the cellular prion protein (PrPC) spontaneously misfolds and assembles into prion fibrils, culminating in fatal neurodegeneration. In a genome-wide association study of sCJD, we recently identified risk variants in and around the gene STX6, with evidence to suggest a causal increase of STX6 expression in disease-relevant brain regions. STX6 encodes syntaxin-6, a SNARE protein primarily involved in early endosome to trans-Golgi network retrograde transport. Here we developed and characterised a mouse model with genetic depletion of Stx6 and investigated a causal role of Stx6 expression in mouse prion disease through a classical prion transmission study, assessing the impact of homozygous and heterozygous syntaxin-6 knockout on disease incubation periods and prion-related neuropathology. Following inoculation with RML prions, incubation periods in Stx6-/- and Stx6+/- mice differed by 12 days relative to wildtype. Similarly, in Stx6-/- mice, disease incubation periods following inoculation with ME7 prions also differed by 12 days. Histopathological analysis revealed a modest increase in astrogliosis in ME7-inoculated Stx6-/- animals and a variable effect of Stx6 expression on microglia activation, however no differences in neuronal loss, spongiform change or PrP deposition were observed at endpoint. Importantly, Stx6-/- mice are viable and fertile with no gross impairments on a range of neurological, biochemical, histological and skeletal structure tests. Our results provide some support for a pathological role of Stx6 expression in prion disease, which warrants further investigation in the context of prion disease but also other neurodegenerative diseases considering syntaxin-6 appears to have pleiotropic risk effects in progressive supranuclear palsy and Alzheimer's disease.

Factors Associated with Prospective Acceptability and Preferences for Unified Transdiagnostic Cognitive-Behavioral Treatments and Group Therapy in the Portuguese General Population.

Group transdiagnostic cognitive-behavioral therapy (CBT) offers a promising solution for limited mental health access in Portugal. Understanding barriers to patient adherence is crucial for successful implementation. This study aimed to characterize the prospective acceptability and preferences for unified transdiagnostic CBT and group therapy in the Portuguese general population and explore their correlates. A sample of 243 participants (18-88 years old), recruited online, completed an online survey collecting information on sociodemographic and clinical characteristics, acceptability of transdiagnostic CBT treatments, specifically of Unified Protocol (UP), acceptability of group therapy, therapeutic format preferences, beliefs about group therapy and help-seeking attitudes. Most participants were receptive to and perceived as useful both unified transdiagnostic CBT and group therapy. Overall, participants presented significantly more favorable attitudes than unfavorable attitudes toward unified transdiagnostic CBT and group therapy (p < .001). Multivariate analyses revealed that (1) favorable attitudes toward transdiagnostic treatments were negatively associated with being employed and positively associated with living in an urban area, and higher efficacy scores; (2) unfavorable attitudes toward transdiagnostic treatments were positively associated with being married/cohabitating and negatively associated with vulnerability scores; (3) being female, living in an urban area, and higher efficacy and myth scores emerged as positive predictors of favorable attitudes toward group therapy; and (4) efficacy and vulnerability scores and help-seeking propensity emerged as negative predictors of unfavorable attitudes toward group therapy. These findings highlight the importance of delineating strategies to increase knowledge and acceptance of unified transdiagnostic CBT and group therapy in the Portuguese population, addressing specific individual characteristics.

Highly infectious prions are not directly neurotoxic.

Prions are infectious agents which cause rapidly lethal neurodegenerative diseases in humans and animals following long, clinically silent incubation periods. They are composed of multichain assemblies of misfolded cellular prion protein. While it has long been assumed that prions are themselves neurotoxic, recent development of methods to obtain exceptionally pure prions from mouse brain with maintained strain characteristics, and in which defined structures-paired rod-like double helical fibers-can be definitively correlated with infectivity, allowed a direct test of this assertion. Here we report that while brain homogenates from symptomatic prion-infected mice are highly toxic to cultured neurons, exceptionally pure intact high-titer infectious prions are not directly neurotoxic. We further show that treatment of brain homogenates from prion-infected mice with sodium lauroylsarcosine destroys toxicity without diminishing infectivity. This is consistent with models in which prion propagation and toxicity can be mechanistically uncoupled.

Haff disease: overview and clinical features.

Haff disease was first described at the beginning of the twentieth century in Europe. Almost a century later, thousands of cases have now been reported in different countries. In Brazil, most cases are observed in the Amazon region, and its associated factors remain to be fully understood. This disease is an uncommon syndrome characterized by intense myalgia and rhabdomyolysis, which manifests within 24 h after consuming some types of freshwater or saltwater fish and crustaceans. A possible heat-stable toxin contained in seafood may be the cause of Haff disease, but this hypothesis is not yet completely proven. This review will describe the clinical and epidemiological aspects of Haff disease with updated literature.

Antimalarial activity of 4-metoxychalcones: docking studies as falcipain/plasmepsin inhibitors, ADMET and lipophilic efficiency analysis to identify a putative oral lead candidate.

Herein, we report the antimalarial activity of nine 4-methoxychalcone derivatives 1a-i and an initial analysis of their ADMET properties. All compounds showed potent activity against the P. falciparum chloroquine-resistant clone W2, with IC50 values ranging from 1.96 µM to 10.99 µM, with moderate or low cytotoxicity against the HeLa cell line. The compound 1a (IC50 = 2.06 µM) had the best selectivity index (9.0). All the sulfonamide 4-metychalcone derivatives synthesized had cLogP values between 2 and 5 (mean value 3.79) and molecular weights (MWs) below 500. The substitution of the pyrrolidine group in 1i by a morpholine group in 1a reduced the cLogP value from 3.05 in compound 1i to 2.34 in compound 1a. Indeed, compound 1a had the highest LipE value. The binding free energy of compound 1a showed it to be the most optimal chalcone derivative for plasmepsin-2 (-7.3 Kcal/mol). The physicochemical properties and LipE analysis of the dataset allowed us to establish that compound 1a is the highest quality compound of the series and a potential oral lead candidate.

Radially and Azimuthally Pure Vortex Beams from Phase-Amplitude Metasurfaces.

To exploit the full potential of the transverse spatial structure of light using the Laguerre-Gaussian basis, it is necessary to control the azimuthal and radial components of the photons. Vortex phase elements are commonly used to generate these modes of light, offering precise control over the azimuthal index but neglecting the radially dependent amplitude term, which defines their associated corresponding transverse profile. Here, we experimentally demonstrate the generation of high-purity Laguerre-Gaussian beams with a single-step on-axis transformation implemented with a dielectric phase-amplitude metasurface. By vectorially structuring the input beam and projecting it onto an orthogonal polarization basis, we can sculpt any vortex beam in phase and amplitude. We characterize the azimuthal and radial purities of the generated vortex beams, reaching a purity of 98% for a vortex beam with l =50 and p = 0. Furthermore, we comparatively show that the purity of the generated vortex beams outperforms those generated with other well-established phase-only metasurface approaches. In addition, we highlight the formation of "ghost" orbital angular momentum orders from azimuthal gratings (analogous to ghost orders in ruled gratings), which have not been widely studied to date. Our work brings higher-order vortex beams and their unlimited potential within reach of wide adoption.

Efficient High-Refractive-Index Azobenzene Dendrimers Based on a Hierarchical Supramolecular Approach.

Real-time manipulation of light in a diffractive optical element made with an azomaterial, through the light-induced reconfiguration of its surface based on mass transport, is an ambitious goal that may enable new applications and technologies. The speed and the control over photopatterning/reconfiguration of such devices are critically dependent on the photoresponsiveness of the material to the structuring light pattern and on the required extent of mass transport. In this regard, the higher the refractive index (RI) of the optical medium, the lower the total thickness and inscription time can be. In this work, we explore a flexible design of photopatternable azomaterials based on hierarchically ordered supramolecular interactions, used to construct dendrimer-like structures by mixing specially designed sulfur-rich, high-refractive-index photoactive and photopassive components in solution. We demonstrate that thioglycolic-type carboxylic acid groups can be selectively used as part of a supramolecular synthon based on hydrogen bonding or readily converted to carboxylate and participate in a Zn(II)-carboxylate interaction to modify the structure of the material and fine-tune the quality and efficiency of photoinduced mass transport. Compared with a conventional azopolymer, we demonstrate that it is possible to fabricate high-quality, thinner flat diffractive optical elements to reach the desired diffraction efficiency by increasing the RI of the material, achieved by maximizing the content of high molar refraction groups in the chemical structure of the monomers.

GPU accelerated real-time multi-functional spectral-domain optical coherence tomography system at 1300 nm.

We present a GPU accelerated multi-functional spectral domain optical coherence tomography system at 1300 nm. The system is capable of real-time processing and display of every intensity image, comprised of 512 pixels by 2048 A-lines acquired at 20 frames per second. The update rate for all four images with size of 512 pixels by 2048 A-lines simultaneously (intensity, phase retardation, flow and en face view) is approximately 10 frames per second. Additionally, we report for the first time the characterization of phase retardation and diattenuation by a sample comprised of a stacked set of polarizing film and wave plate. The calculated optic axis orientation, phase retardation and diattenuation match well with expected values. The speed of each facet of the multi-functional OCT CPU-GPU hybrid acquisition system, intensity, phase retardation, and flow, were separately demonstrated by imaging a horseshoe crab lateral compound eye, a non-uniformly heated chicken muscle, and a microfluidic device. A mouse brain with thin skull preparation was imaged in vivo and demonstrated the capability of the system for live multi-functional OCT visualization.

A 3-alkylpyridine-bearing alkaloid exhibits potent antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with no detectable resistance.

Staphylococcus aureus is a Gram-positive bacterium responsible for a wide variety of infectious diseases, and its methicillin-resistant isolates pose a serious worldwide public health risk. New drugs are urgently needed for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. Here, we evaluated the antibacterial activity of five 3-alkyl-pyridinic analogs against MRSA and, of these compounds, compound 6 showed promising antibacterial activity against Staphylococcus with minimum inhibitory concentration (MIC) ranging from 0.98 to 3.9 µgmL-¹ . In addition, it exhibited a rapid bactericidal action, with complete elimination of MRSA after 6 h of incubation at 15.6 µgmL-¹ . Compound 6 had the ability to damage the bacterial membrane and induce cell lysis and, due to its action on the membrane, showed low resistance induction potential in vitro. In the combination study, compound 6 revealed an additive effect (FICI = 1) with vancomycin and ofloxacin and ciprofloxacin (FICI = 0.75) against MRSA, reducing the effective concentration of this antibiotic two-fold. The anti-staphylococcal activity of compound 6 was stable in the presence of different concentrations of NaCl (50, 200, and 400 µM), trypsin ( 1:500, 1:250) and under a variety of pH values (4, 5, 6, and 8); however, its binding to plasmatic proteins (i.e., albumin) was substantial. The previous exposure of MRSA to the compound was able to reduce the formation of bacterial biofilm and reduce the biomass of mature biofilms. Compound 6 showed low selectivity in vitro for MRSA USA 300 when compared to eukaryotic cells (epithelial, fibroblast, and red blood cells).

First report of polymyxin B activity in Klebsiella pneumoniae biofilm.

Considering the clinical importance of biofilm in medical devices and chronic infections, this study aimed to investigate the action of polymyxin B on Klebsiella pneumoniae (K. pneumoniae) biofilm. The experiments were performed using a biofilm formation assay and the interaction of polysorbate 80 was explored. Both inhibition of biofilm formation and reduction of pre-formed biofilm occurred in a concentration-dependent manner with inhibition as high as 56 and 64%, and reduction of pre-formed biofilm as high as 70 and 66%, with and without polysorbate, respectively. The addition of polysorbate enhances the biofilm reduction, but more studies are needed to elucidate this mechanism. Our findings reveal, for the first time, polymyxin B as a potential agent for the treatment of K. pneumoniae biofilm, a current challenge for clinical practice.

Qualidade de vida dos estudantes de Odontologia na pandemia da COVID-19: um estudo observacional transversal em duas universidades públicas / Quality of life of Dentistry during the Covid-19 pandemic: a cross-sectional observational study / Calidad de vida de estudantes de odontologia durante la pandemia de COVID-19: un estudo observacional

O objetivo deste estudo foi avaliar a qualidade de vida (QV) dos estudantes de dois cursos de Odontologia da Universidade Federal do Ceará (UFC) durante a pandemia da Coronavirus Disease2019. Foi realizado um estudo transversal, com coleta de dados em maio de 2020, por meio de questionários que mensuraram as variáveis sociodemográficas, relacionadas ao curso e comportamentais, além do World Health Organization Questionnaire for Quality of Life-bref. Foi realizada regressão logística multinomial. Ocorreu a participação de 396 estudantes. Observou-se que 64,1% dos acadêmicos apresentavam-se insatisfeitos quanto à QV. Variáveis como renda mensal (p=0,018), religião (p=0,012), qualidade do sono (p<0,001), insônia (p<0,001) e prática de atividade física (p<0,001) foram associadas com a insatisfação com a QV. A QV dos acadêmicos de Odontologia da UFC foi insatisfatória, a partir da análise dos baixos escores dos questionários, sendo importante que todos os envolvidos no processo educacional sejam sensíveis a esta realidade, a fim de tentar modificá-la (AU).

El objetivo de este estudio fue evaluar la calidad de vida (CV) de estudiantes de dos carreras de Odontología de la Universidad Federal de Ceará (UFC) durante la pandemia de Enfermedad por Coronavirus 2019. Se realizó un estudio transversal, con recolección de datos en mayo de 2020, a través de cuestionarios que midieron variables sociodemográficas, de curso y de comportamiento, además del Cuestionario de Calidad de Vida-bref de la Organización Mundial de la Salud. Se realizó regresión logística multinomial. Participaron 396 estudiantes. Se observó que el 64,1% de los estudiantes estaban insatisfechos con su CV. Variables como ingreso mensual (p=0,018), religión (p=0,012), calidad del sueño (p<0,001), insomnio (p<0,001) y actividad física (p<0,001) se asociaron con la insatisfacción con la calidad de vida. La calidad de vida de los estudiantes de Odontología de la UFC fue insatisfactoria, según el análisis de los bajos puntajes en los cuestionarios, y es importante que todos los involucrados en el proceso educativo sean sensibles a esta realidad, para intentar cambiarla (AU).

The aim of this study was to assess the quality of life (QoL) of students from two Dentistry courses at the Federal University of Ceará (UFC) during the Coronavirus Disease 2019 pandemic. A cross-sectional study was carried out, with data collected in May 2020, using questionnaires that measured sociodemographic, course-related and behavioral variables, in addition to the World Health Organization Questionnaire for Quality of Life-bref. Multinomial logistic regression was performed. A total of 396 students took part. It was observed that 64.1% of students were dissatisfied with their QoL. Variables such as monthly income (p=0.018), religion (p=0.012), sleep quality (p<0.001), insomnia (p<0.001) and practicing physical activity (p<0.001) were associated with dissatisfaction with QoL. The QoL of UFC Dentistry students was unsatisfactory, based on the analysis of the low scores on the questionnaires, and it is important that everyone involved in the educational process is sensitive to this reality, in order to try to change it (AU).

Determination of free and total sulfur(IV) compounds in coconut water using high-resolution continuum source molecular absorption spectrometry in gas phase.

This work proposes a method for the determination of free and total sulfur(IV) compounds in coconut water samples, using the high-resolution continuum source molecular absorption spectrometry. It is based on the measurement of the absorbance signal of the SO2 gas generate, which is resultant of the addition of hydrochloric acid solution on the sample containing the sulfating agent. The sulfite bound to the organic compounds is released by the addition of sodium hydroxide solution, before the generation of the SO2 gas. The optimization step was performed using multivariate methodology involving volume, concentration and flow rate of hydrochloric acid. This method was established by the sum of the absorbances obtained in the three lines of molecular absorption of the SO2 gas. This strategy allowed a procedure for the determination of sulfite with limits of detection and quantification of 0.36 and 1.21mgL-1 (for a sample volume of 10mL) and precision expressed as relative standard deviation of 5.4% and 6.4% for a coconut water sample containing 38.13 and 54.58mgL-1 of free and total sulfite, respectively. The method was applied for analyzing five coconut water samples from Salvador city, Brazil. The average contents varied from 13.0 to 55.4mgL-1 for free sulfite and from 24.7 to 66.9mgL-1 for total sulfur(IV) compounds. The samples were also analyzed employing the Ripper´s procedure, which is a reference method for the quantification of this additive. A statistical test at 95% confidence level demonstrated that there is no significant difference between the results obtained by the two methods.

Effects of grazing management in brachiaria grass-forage peanut pastures on canopy structure and forage intake1.

Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A 2-yr experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 d (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at 5 points above the canopy for each paddock using a canopy analyzer. For all treatments, the postgrazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre- and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited NDF intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible OM (P = 0.007) and the ratio of CP/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency of microbial synthesis (P = 0.023) were greater at 95LI and 90LI, followed by 42D and less at 100LI. Overall, the range from 90% to 95% of LI is the recommendation to interrupt the rest period, since this strategy enhanced community stability, forage intake, and nutritional value of the diet. Under on-farm conditions, brachiaria grass and forage peanut pastures should be managed at a range height of 24 to 30 cm.

Localization of cortical tissue optical changes during seizure activity in vivo with optical coherence tomography.

Optical coherence tomography (OCT) is a high resolution, minimally invasive imaging technique, which can produce depth-resolved cross-sectional images. In this study, OCT was used to detect changes in the optical properties of cortical tissue in vivo in mice during the induction of global (pentylenetetrazol) and focal (4-aminopyridine) seizures. Through the use of a confidence interval statistical method on depth-resolved volumes of attenuation coefficient, we demonstrated localization of regions exhibiting both significant positive and negative changes in attenuation coefficient, as well as differentiating between global and focal seizure propagation.

Prion neuropathology follows the accumulation of alternate prion protein isoforms after infective titre has peaked.

Prions are lethal infectious agents thought to consist of multi-chain forms (PrP(Sc)) of misfolded cellular prion protein (PrP(C)). Prion propagation proceeds in two distinct mechanistic phases: an exponential phase 1, which rapidly reaches a fixed level of infectivity irrespective of PrP(C) expression level, and a plateau (phase 2), which continues until clinical onset with duration inversely proportional to PrP(C) expression level. We hypothesized that neurotoxicity relates to distinct neurotoxic species produced following a pathway switch when prion levels saturate. Here we show a linear increase of proteinase K-sensitive PrP isoforms distinct from classical PrP(Sc) at a rate proportional to PrP(C) concentration, commencing at the phase transition and rising until clinical onset. The unaltered level of total PrP during phase 1, when prion infectivity increases a million-fold, indicates that prions comprise a small minority of total PrP. This is consistent with PrP(C) concentration not being rate limiting to exponential prion propagation and neurotoxicity relating to critical concentrations of alternate PrP isoforms whose production is PrP(C) concentration dependent.

Extracting structural features of rat sciatic nerve using polarization-sensitive spectral domain optical coherence tomography.

We present spectral domain polarization-sensitive optical coherence tomography (SD PS-OCT) imaging of peripheral nerves. Structural and polarization-sensitive OCT imaging of uninjured rat sciatic nerves was evaluated both qualitatively and quantitatively. OCT and its functional extension, PS-OCT, were used to image sciatic nerve structure with clear delineation of the nerve boundaries to muscle and adipose tissues. A long-known optical effect, bands of Fontana, was also observed. Postprocessing analysis of these images provided significant quantitative information, such as epineurium thickness, estimates of extinction coefficient and birefringence of nerve and muscle tissue, frequency of bands of Fontana at different stretch levels of nerve, and change in average birefringence of nerve under stretched condition. We demonstrate that PS-OCT combined with regular-intensity OCT (compared with OCT alone) allows for a clearer determination of the inner and outer boundaries of the epineurium and distinction of nerve and muscle based on their birefringence pattern. PS-OCT measurements on normal nerves show that the technique is promising for studies on peripheral nerve injury.

Public Knowledge about and Detection of Canine Visceral Leishmaniasis in Urban Divinópolis, Brazil.

Background. Leishmaniases are diseases with a wide spectrum of clinical manifestations including cutaneous (CL) and visceral (VL) forms. Many factors may affect their occurrence and expansion including environmental, geographic, and social conditions. In the past two decades, Divinópolis, Minas Gerais State, Brazil, has exhibited the potential for a disease outbreak, with the appearance of CL, and VL cases (human and canine). Hence, this study was initiated to monitor public knowledge of the disease. Questionnaires were administered in four neighborhoods (Jardim Belvedere, Esplanada, Danilo Passos I and II) where most of the human and canine cases have been reported. The analyses demonstrated that public knowledge of the disease is sparse and fragmented. A strong perception of the dog as the main reservoir was observed. Five veterinary clinics were evaluated for the presence of canine VL using serological (RIFI and ELISA) and molecular (PCR-RFLP) techniques. This is the first study demonstrating the occurrence of Leishmania infantum in Divinópolis, suggesting a possible urbanization of VL.

Atrophy in two attention networks is associated with performance on a Flanker task in neurodegenerative disease.

This study investigated the neurobiological basis of attentional control dysfunction in neurodegenerative disease by determining the effect of regional brain atrophy on Flanker task performance of neurodegenerative patients. We hypothesized that atrophy in DLPFC and ACC would be significantly associated with decreased attentional control performance on the Flanker task. We used voxel-based morphometry (VBM) to measure the relationship between MRI measures of regional grey matter atrophy and performance on a version of the Flanker task, measured by accuracy and response time. Sixty-five subjects participated, including patients with frontotemporal dementia, Alzheimer's disease, mild cognitive impairment, non-fluent progressive aphasia, corticobasal degeneration, progressive supranuclear palsy, semantic dementia, and healthy controls. Accuracy measures of attentional control and response time measures of attentional control were associated with two different patterns of regional atrophy across subjects. First, there was an association between left hemisphere DLPFC and ACC atrophy and poorer attentional control accuracy. Second, right hemisphere temporal-parietal junction (TPJ) and ventrolateral prefrontal cortex (VLPFC) and DLPFC atrophy were associated with slower response times during attentional control on accurate trials, which may reflect emergent involvement due to deficits in the DLPFC-ACC network.

Estudo farmacognóstico comparativo das folhas de Davilla elliptica A. St.-Hil. e D. rugosa Poir., Dilleniaceae / Comparative pharmacognostic study of leaves of Davilla elliptica A. St.-Hil. e D. rugosa Poir., Dilleniaceae

As características farmacognósticas das folhas de Davilla elliptica A. St.-Hil. e D. rugosa Poir., Dilleniaceae, foram determinadas com objetivo de auxiliar na identificação taxonômica e no controle de qualidade das drogas vegetais e de produtos fitoterápicos. A espécie D. elliptica é um arbusto ereto, que ocorre naturalmente no cerrado e D. rugosa é um trepadeira lenhosa de beira de mata. Ambas são conhecidas popularmente como lixeirinha, sambaibinha e cipó-caboclo, empregadas na medicina tradicional como antiinflamatória e antiúlcera. As características microscópicas observadas em D. rugosa tais como tricomas estrelados e esclereídes no mesofilo e em D. elliptica de idioblastos contendo mucilagem e endoderme, são parâmetros que poderão ser utilizados na diferenciação das espécies. Os teores obtidos nos ensaios de pureza e nos doseamentos de taninos (9,4 por cento e 7,2 por cento), flavonoides (0,46 por cento e 0,9 por cento) e mucilagens (2,2 por cento e 4,1 por cento) de ambas as espécies, podem contribuir no controle de qualidade das drogas vegetais uma vez que são usadas indistintamente na produção de fitoterápicos.

The characters pharmacognostics of leaves of Davilla elliptica St. Hil. and Davilla rugosa Poir. of Dilleniaceae family were determinated for aiming in taxonomic and quality control of vegetable drugs and phytotherapic produtcs. The specie of D. elliptica is an erect shrub, that occurs naturally in cerrado and D. rugosa is a scandent shrub of forest edge. Both are populary known as "lixeirinha", "sambaibinha" and "cipó-caboclo" and used in popular medicine as anti-inflammatory and antiulcer. The microscopic characteristics observed like strellate trichomes and sclereids in the mesophyll in D. rugosa and the idioblasts with mucilage and endodermis in D. elliptica are parameter that will be used to differentiate the species. The content obtained in tests of purity and the tannins (9.4 percent and 7.2 percent), flavonoids (0.46 percent and 0.9 percent) and mucilage (2.2 percent and 4.1 percent) of both species help in quality control of vegetable drugs since they are indistinctly used in production of phytotherapics.