Do photosynthetic metabolism and habitat influence foliar water uptake in orchids?

Epiphytic and rupicolous plants inhabit environments with limited water resources. Such plants commonly use Crassulacean Acid Metabolism (CAM), a photosynthetic pathway that accumulates organic acids in cell vacuoles at night, so reducing their leaf water potential and favouring water absorption. Foliar water uptake (FWU) aids plant survival during drought events in environments with high water deficits. We hypothesized that FWU represents a strategy employed by epiphytic and rupicolous orchids for water acquisition and that CAM will favour increased water absorption. We examined 6 epiphyte, 4 terrestrial and 6 rupicolous orchids that use C3 (n = 9) or CAM (n = 7) pathways. Five individuals per species were used to evaluate FWU, structural characteristics and leaf water balance. Rupicolous species with C3 metabolism had higher FWU than other species. FWU (Cmax and k) could be related to succulence, SLM and leaf RWC. The results indicated that high orchid leaf densities favoured FWU, as area available for water storage increases with leaf density. Structural characteristics linked to water storage (e.g. high RWC, succulence), on the other hand, could limit leaf water absorption by favouring high internal leaf water potentials. Epiphytic, rupicolous and terrestrial orchids showed FWU. Rupicolous species had high levels of FWU, probably through absorption from mist. However, succulence in plants with CAM appears to mitigate FWU.

Neuropsychological manifestations of long COVID in hospitalized and non-hospitalized Brazilian Patients.

BACKGROUND: There has been a significant increase in number of patients seeking neuropsychological rehabilitation months after the acute phase of COVID-19 infection. OBJECTIVE: Identify the cognitive and psychiatric disorders in patients with long COVID or Post-Acute Sequelae of COVID (PASC) and explore the association between disease severity during the acute phase and persistent neuropsychological manifestations. METHODS: 614 adults were assessed an average of eight months post-infection. Participants were, on average, 47.6 y.o., who sought rehabilitation for neuropsychological problems. Patients were evaluated using the Barrow Neurological Institute Screen for Higher Cerebral Functions (BNIS), Phonemic Verbal Fluency and Clock Drawing tests (NEUPSILIN) for executive functions, and the Hospital Anxiety and Depression Scale (HADS). RESULTS: The BNIS score was significantly below reference values in all subscales, especially affect and memory. Verbal Fluency and Clock Drawing subtest results were also lower. Patients with PASC tested high for anxiety/depression, but there was no statistically significant relationship between HADS and BNIS scores. Neuropsychological evaluations showed no differences in cognitive or psychiatric profiles between hospitalized and non-hospitalized patients. CONCLUSIONS: Neuropsychological results suggest executive function problems and high incidence of anxiety/depression, irrespective of acute-phase severity, underscoring a need for neurorehabilitation programs while providing data for public policy initiatives.

Dietary supplementation with whey protein improves systemic microvascular function in heart failure patients: a pilot study.

Endothelial dysfunction is a well-known component of the pathophysiology of heart failure (HF), with proven prognostic value. Dietary supplementation with whey protein (WP) has been widely used to increase skeletal muscle mass, but it also has vascular effects, which are less understood. This study aimed to evaluate the effects of WP supplementation on the systemic microvascular function of HF patients. This was a blinded, randomized, placebo-controlled clinical trial that evaluated the effects of 12-week WP dietary supplementation on systemic microvascular function, in patients with HF New York Heart Association (NYHA) classes I/II. Cutaneous microvascular flow and reactivity were assessed using laser speckle contrast imaging, coupled with pharmacological local vasodilator stimuli. Fifteen patients (aged 64.5±6.2 years, 11 males) received WP supplementation and ten patients (aged 68.2±8.8 years, 8 males) received placebo (maltodextrin). The increase in endothelial-dependent microvascular vasodilation, induced by skin iontophoresis of acetylcholine, was improved after WP (P=0.03) but not placebo (P=0.37) supplementation. Moreover, endothelial-independent microvascular vasodilation induced by skin iontophoresis of sodium nitroprusside, was also enhanced after WP (P=0.04) but not placebo (P=0.42) supplementation. The results suggested that dietary supplementation with WP improved systemic microvascular function in patients with HF.

Dietary supplementation with whey protein improves systemic microvascular function in heart failure patients: a pilot study

Endothelial dysfunction is a well-known component of the pathophysiology of heart failure (HF), with proven prognostic value. Dietary supplementation with whey protein (WP) has been widely used to increase skeletal muscle mass, but it also has vascular effects, which are less understood. This study aimed to evaluate the effects of WP supplementation on the systemic microvascular function of HF patients. This was a blinded, randomized, placebo-controlled clinical trial that evaluated the effects of 12-week WP dietary supplementation on systemic microvascular function, in patients with HF New York Heart Association (NYHA) classes I/II. Cutaneous microvascular flow and reactivity were assessed using laser speckle contrast imaging, coupled with pharmacological local vasodilator stimuli. Fifteen patients (aged 64.5±6.2 years, 11 males) received WP supplementation and ten patients (aged 68.2±8.8 years, 8 males) received placebo (maltodextrin). The increase in endothelial-dependent microvascular vasodilation, induced by skin iontophoresis of acetylcholine, was improved after WP (P=0.03) but not placebo (P=0.37) supplementation. Moreover, endothelial-independent microvascular vasodilation induced by skin iontophoresis of sodium nitroprusside, was also enhanced after WP (P=0.04) but not placebo (P=0.42) supplementation. The results suggested that dietary supplementation with WP improved systemic microvascular function in patients with HF.

Enzyme-mediated metabolism in nutritive tissues of galls induced by Ditylenchus gallaeformans (Nematoda: Anguinidae).

The galls induced by Ditylenchus gallaeformans (Nematoda) on leaves of Miconia albicans have unique features when compared to other galls. The nematode colonies are surrounded by nutritive tissues with promeristematic cells, capable of originating new emergences facing the larval chamber, and providing indeterminate growth to these galls. Considering enzyme activity as essential for the translocation of energetic molecules from the common storage tissue (CST) to the typical nutritive tissue (TNT), and the major occurrence of carbohydrates in nematode galls, it was expected that hormones would mediate sink strength relationships by activating enzymes in indeterminate growth regions of the galls. Histochemical, immunocytochemical and quantitative analyses were made in order to demonstrate sites of enzyme activity and hormones, and comparative levels of total soluble sugars, water soluble polysaccharides and starch. The source-sink status, via carbohydrate metabolism, is controlled by the major accumulation of cytokinins in totipotent nutritive cells and new emergences. Thus, reducing sugars, such as glucose and fructose, accumulate in the TNT, where they supply the energy for successive cycles of cell division and for nematode feeding. The histochemical detection of phosphorylase and invertase activities indicates the occurrence of starch catabolism and sucrose transformation into reducing sugars, respectively, in the establishment of a gradient from the CST towards the TNT. Reducing sugars in the TNT are important for the production of new cell walls during the indeterminate growth of the galls, which have increased levels of water-soluble polysaccharides that corroborate such a hypothesis. Functional relationship between plant hormone accumulation, carbohydrate metabolism and cell differentiation in D. gallaeformans-induced galls is attested, providing new insights on cell development and plant metabolism.

Could polymorphisms in ABCB1 gene represent a genetic risk factor for the development of mammary tumors in dogs?

The ABCB1 gene encodes the P-glycoprotein (P-gp) which regulates distribution and bioavailability of many endogenous and exogenous substrates, acting as a cellular mechanism of protection against these substances. Some studies have shown evidence that P-gp is related to carcinogenesis. In this study, we performed PCR and direct sequencing of ABCB1 exons 9 and 26 in 47 tissue DNA samples from canine mammary tumors. A statistically significant correlation between distinct canine breeds and the frequency of ABCB1 polymorphisms (c.985T > A and c.3442A > G SNP in ABCB1exons 9 and 26, respectively) was observed (P = 0.0015). In contrast, the TNM clinical staging, age, histological type and grade, as well as other histopathological characteristics, did not present statistically significant difference in relation to one or both SNP found in exons 9 and 26. These findings raise questions about the role of the canine ABCB1 polymorphisms in the development of mammary tumors, since the Poodle breed, which is the most common dog breed affected by mammary tumors in Brazil, presented the highest frequency of these variants. Notwithstanding, additional studies comprising a number of samples expressing the ABCB1 gene from healthy dogs, with advanced age and from different breeds, will be necessary to confirm the association of ABCB1polymorphisms and the development of mammary tumors.

Tricuspid valve dysplasia and a patent foramen ovale resulting in severe tricuspid regurgitation and right-heart dilation in a Red Angus calf.

A two-month-old Red Angus heifer calf presented to the University of Wisconsin Veterinary Care for evaluation of suspected severe bronchopneumonia. Pertinent physical exam findings included tachycardia, tachypnea, dyspnea with a significant abdominal component, and cyanotic mucous membranes. On thoracic auscultation, wheezes were present bilaterally, as well as a grade 2/6 right apical systolic murmur. Thoracic radiographs revealed cardiomegaly, most severely affecting the right side. Echocardiography showed tricuspid valve dysplasia, resulting in severe tricuspid regurgitation and right-heart dilation, as well as a patent foramen ovale. A postmortem examination confirmed the presence of the aforementioned cardiac abnormalities and revealed only mild pulmonary changes. This case report is the first to describe tricuspid dysplasia in the absence of multiple, complex congenital cardiac abnormalities in a calf, and it highlights the value of echocardiography for an antemortem diagnosis.

Association Between Citrus Flushing Cycles and Asian Citrus Psyllid Demography in Huanglongbing-Free Area in Brazil.

Diaphorina citri Kuwayama (Hemiptera: Liviidae), named as Asian citrus psyllid (ACP), is the vector of the bacterium associated with huanglongbing (HLB), the most destructive citrus disease. The use of citrus flushing and ACP monitoring tools is essential for the knowledge of the occurrence pattern of cycles of both and for the improvement of the ACP management. During 3 years, 20 branches from 20 trees were evaluated for vegetative flushing, ACP abundance, and occupation in tree and branches in a Brazilian citrus area free for HLB. The obtained data was investigated through spectral and co-spectral analyses. Four to 12 flush shoot cycles occurred per year, which were similar to abundance and occupation cycles of ACP, with an apparent synchronization between these variables. In general, there was a difference from 14 to 19 days between flushing and ACP peaks, with an occurrence of the flushing peaks before the ACP peaks. Results will provide useful information to citrus growers and agricultural defense agencies to apply a suitable and targeted ACP management, which will avoid or delay the disease entrance into still free HLB areas. In addition, the modeling of occupation and abundance cycles of vectors as applied in this study may be useful for other pathosystems which insect vectors are associated or even in the intrusion monitoring programs.

Xylo-oligosaccharides display a prebiotic activity when used to supplement wheat or corn-based diets for broilers.

It is now well established that exogenous ß-1,4-xylanases improve the nutritive value of wheat-based diets for poultry. Among other factors, the mechanism of action of exogenous enzymes may involve a microbial route resulting from the generation of prebiotic xylo-oligosaccharides (XOS) in the birds' gastro-intestinal (GI) tract. In a series of three experiments, the effect of XOS on the performance of broilers fed wheat or corn-based diets was investigated. In experiment 1, birds receiving diets supplemented with XOS displayed an increased weight gain (P = 0.08). The capacity of XOS to improve the performance of animals during a longer trial (42 d) was investigated (Experiment 2). The data revealed that diet supplementation with XOS, tested at two incorporation rates (0.1 and 1 g/kg), or with an exogenous ß-1,4-xylanase resulted in an increased nutritive value of the wheat-based diet. An improvement in animal performance was accompanied by a shift in the microbial populations colonizing the upper portions of the GI tract. XOS were also able to improve the performance of broilers fed a corn-based diet, although the effects were not apparent at incorporation rates of 10 g/kg. Together these studies suggest that in some cases the capacity of ß-1,4-xylanases to improve the nutritive value of wheat-based diets is more related to their ability to produce prebiotic XOS than to their ability to degrade arabinoxylans. The extremely low quantities of XOS used in this study also challenge the depiction of a prebiotic being a quantitatively fermented substrate. These data also bring into question the validity of the "cell wall" mechanism, as XOS elicited an effect with clearly no action on endosperm cell wall integrity and yet the performance effects noted were equivalent or superior to the added enzymes.

Common germline haplotypes and genotypes identified in BRCA2 exon 11 of dogs with mammary tumours and histopathological analyses.

The canine BRCA2 is a tumor supressor gene which encodes the BRCA2 protein, involved in DNA repair through interaction with the RAD51 recombinase. This process is mediated by eigth BRC repeats that are encoded by BRCA2 exon 11. Two variants corresponding to human mutations in human BRC3 repeat have been reported in canine BRC3 repeat. In addition, other variants have also been described in canine BRCA2 exon 11. Considering the importance of polymorphisms in human BRCA2 to breast cancer development, this study aimed to investigate the frequency of variants in BRCA2 exon 11 in 48 blood and tissue DNA samples from bitches with canine mammary tumors (CMT), as well as, to analyze tumor stage and histopathological features. Seven Single Nucleotide Polymorphisms (SNPs) were identified, three of which were evaluated as possibily or probably deleterious variant. Interestingly, almost all the 22 mammary tumors (except one) which presented a clinical staging equal to or greater than III carried at least one mutant allele of these three variants. Besides that, no statistically significant correlation was observed between any of the reported SNPs in heterozygosis or homozygosis and either dogs data (such as breed, age or disease stage) or mammary tumors histopathological characteristics. A total of 97.9% of bitches had one to three polymorphisms of the seven identified in this study, which suggests a possibly correlation between the canine BRCA2 exon 11 polymorphisms and mammary carcinogenesis.

Quality Control of Compounded Crystalloid Fluids for Intravenous Delivery to Horses.

BACKGROUND: Periodic lack of availability and high cost of commercially produced isotonic fluids for intravenous (IV) use in horses have increasingly led to use of home-made or commercially compound fluids by veterinarians. Data regarding the quality control and safety of compounded fluids would be of benefit to equine veterinarians. OBJECTIVES: To compare electrolyte concentrations, sterility, and endotoxin contamination of commercially available fluids to 2 forms of compounded isotonic crystalloid fluids intended for IV use in horses. METHODS: Prospective study. Two methods of preparing compounded crystalloids formulated to replicate commercial Plasma-Lyte A (Abbott, Chicago, IL) were compared. One formulation was prepared by a hand-mixed method involving chlorinated drinking water commonly employed by equine practitioners, and the other was prepared by means of ingredients obtained from a commercial compounding pharmacy. The variables for comparison were electrolyte concentrations, sterility, and presence of endotoxin contamination. RESULTS: Electrolyte concentrations were consistent within each product but different between types of fluids (P < 0.0001). Hand-mixed fluids had significantly more bacterial contamination compared to commercial Plasma-Lyte A (P = 0.0014). One of the hand-mixed fluid samples had detectable endotoxin contamination. CONCLUSIONS AND CLINICAL IMPORTANCE: Chlorinated drinking water is not an acceptable source of water to compound isotonic fluids for IV administration. Equine practitioners should be aware of this risk and obtain the informed consent of their clients.

Phytosterol-enriched milk lowers LDL-cholesterol levels in Brazilian children and adolescents: Double-blind, cross-over trial.

BACKGROUND AND AIMS: Despite evidence of the lipid-lowering effect of plant sterols among adults with hypercholesterolemia, data regarding phytosterol use in children are limited. In this paper, we examined the effects of daily consumption of a phytosterol-enriched milk compound on the lipid profiles of Brazilian children and adolescents with dyslipidemia. METHODS AND RESULTS: This was a randomized, double blind, crossover clinical trial. Twenty eight dyslipidemics outpatients (aged 6-9 years) from an University Hospital were randomly allocated to control or intervention group. The intervention group received milk enriched with 1.2 g/day of plant sterol and the control group received the equivalent amount of skim milk during the period of 8 weeks. Changes from baseline in the mean lipid profile, including total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and triglyceride (TG) concentrations. Serum lipid profiles, glucose levels, dietary and anthropometric data were determined at weeks 0, 4, 8, 16, and 20. Details regarding the safety and tolerance of phytosterol were obtained, using an open-ended questionnaire. Intention-to-treat analysis were performed, using the proc mixed procedure in SAS. After 8 weeks, the mean concentrations of TC and LDL-C were significantly reduced in the intervention group as compared to the control group with reductions of 5.9% (p = 0.09) and 10.2% (p = 0.002), respectively. In addition, TG concentrations were reduced by 19.7% (p = 0.09). No serious side effects were reported during the study. CONCLUSION: Our results confirm that plant sterols are an effective and safe treatment of infantile dyslipidemia. TRIAL REGISTRATION: RBR-3h7f9k.

Use of omalizumab in the treatment of chronic urticaria.

BACKGROUND: Omalizumab is indicated to treat chronic spontaneous urticaria (CSU) refractory to antihistamines. We aim to describe the experience of our department in the treatment of CSU with omalizumab. MATERIALS AND METHODS: Retrospective review of the clinical records of patients. RESULTS: Six patients (5 females, median age 33 years) treated with omalizumab for a median of 17.5 months were evaluated. All patients had improvement of symptoms after the first dose. In one case, the treatment was suspended after 7 months, but in 9 weeks there was recurrence of symptoms. The main side effect was headache in the drug administration's day. Currently, all patients maintain therapy with omalizumab and are clinically stable. CONCLUSION: Omalizumab proved to be an effective and safe drug for the treatment of patients with refractory CSU.

Antifungal treatment in allergic bronchopulmonary aspergillosis with and without cystic fibrosis: a systematic review.

Allergic bronchopulmonary aspergillosis (ABPA) is a rare disease that affects patients with asthma or cystic fibrosis. Its debilitating course has led to the search for new treatments, including antifungals and monoclonal antibodies. To evaluate the efficacy and safety of antifungal treatments in patients with ABPA and either asthma or cystic fibrosis, we performed a systematic review of the literature on the effects of antifungal agents in ABPA using three biomedical databases. Quality assessment was performed using the GRADE methodology and, where appropriate, studies with comparable outcomes were pooled for meta-analysis. Thirty-eight studies - four randomized controlled trials and 34 observational studies - met the eligibility criteria. The antifungal interventions described were itraconazole, voriconazole, posaconazole, ketoconazole, natamycin, nystatin and amphotericin B. An improvement in symptoms, frequency of exacerbations and lung function was reported in most of the studies and was more common with oral azoles. Antifungals also had a positive impact on biomarkers and radiological pulmonary infiltrates, but adverse effects were also common. The quality of the evidence supporting these results was low or very low due to a shortage of controlled studies, heterogeneity between studies and potential bias. Antifungal interventions in ABPA improved patient and disease outcomes in both asthma and cystic fibrosis. However, the recommendation for their use is weak and clinicians should therefore weigh up desirable and undesirable effects on a case-by-case basis. More studies with a better methodology are needed, especially in cystic fibrosis, to increase confidence in the effects of antifungal treatments in ABPA.

Validation of otolith daily increments in early juveniles of shanny Lipophrys pholis.

To assess the periodicity of micro-increment formation in otoliths of Lipophrys pholis, 90 early juveniles were immersed in alizarin red S or tetracycline hydrochloride for 24 h and sacrificed after 10, 20 and 30 days. The number of micro-increments viewed under light microscopy was significantly related to the duration of the experimental period, and the slopes of the linear regressions were not significantly different from 1. This study indicates that micro-increments in sagittae were deposited daily and can be used as reliable sources of age information for L. pholis.

Desempenho de frangos caipiras alimentados com rações contendo diferentes níveis de energia metabolizável / Performance of broiler chickens fed diets containing different levels of metabolizable energy

Analisaram-se os efeitos da energia metabolizável (EM) e da idade de abate sobre o desempenho zootécnico, o rendimento de carcaça e de partes de frangos da linhagem Caipira Francês Exótico. Foram utilizadas 192 aves, distribuídas em delineamento inteiramente ao acaso, com três tratamentos e quatro repetições de 16 aves cada. Os tratamentos (T) foram definidos de acordo com os níveis de energia das dietas inicial (1 a 28 dias) e final (29 a 90 dias), respectivamente, em: T1 - 3.000 e 3.100kcal de EM/kg; T2 - 3.100 e 3.200kcal de EM/kg; T3 - 3.200 e 3.300kcal de EM/kg. Os abates foram realizados aos 77, 84 e 90 dias. Na fase inicial, as aves do T2 e do T3 apresentaram maior peso médio (655,75 e 713,50g), maior ganho de peso (24,28 e 26,42g/ave) e melhor conversão alimentar (1,59 e 1,77), e não diferiram entre si (P>0,05). Quando abatidas aos 77 dias de idade, as aves que consumiram a dieta com 3.100/3.200kcal de EM/kg apresentaram maior rendimento de carcaça (82,20%) e de peito (24,26%), e não diferiram dos frangos alimentados com dietas contendo 3.000/3.200kcal de EM/kg, nos quais se verificaram rendimento de carcaça de 80,72% e 23,20% de rendimento de peito. Os frangos da linhagem Caipira Francês Exótico apresentaram melhores desempenho zootécnico e rendimento de carcaça quando alimentados com dietas contendo 3.100 a 3.200kcal de EM/kg na ração e abatidos aos 77 dias de idade.

This is study aimed to analyze the effects of metabolizable energy (ME) and age at slaughter on growth performance, carcass yield and prime cuts, relative weight of the wings, back, head + neck and feet of broiler chickens from the Caipira Francês Exótico strain. A total of 192 birds were distributed in a completely randomized design with three treatments and four replicates of 16 birds per treatment. The treatments were defined according to levels of dietary energy (1 to 28 days) and late (29-90 days), respectively: T1 - 3000 and 3100kcal/kg ME, T2 - 3100 and 3200kcal/kg ME, T3 - 3200 and 3300kcal/kg ME. The slaughter was carried out at 77, 84 and 90 days. In the initial phase the birds from T2 and T3 had a higher mean weight (655.75 and 713.50g), weight gain (24.28 and 26.42g/bird) and better feed gain (1.59 and 1.77) and did not differ (P>0.05). When slaughtered at 77 days of age, birds fed the diet with 3.100/3.200kcal/kg ME had higher carcass yield (82.20%) and breast (24.26%), and did not differ from chickens fed diets containing 3.000/3.200kcal/kg ME, where a carcass yield of 80.72% and 23.20% of breast yield was found. The Caipira Francês Exótico broilers had better growth performance and carcass yield than when fed diets containing 3100-3200kcal/kg in the diet and slaughtered at 77 days old.

Nutritional assessment associated with length of inpatients' hospital stay.

OBJECTIVE: To evaluate the nutritional status of patients on hospital admission, identify the length of hospital stay and identify the parameters of nutritional assessment that are most closely related with the length of stay (LOS). METHODS: A cross-sectional study of 278 hospitalized patients evaluated patients' nutritional status in the 48 hours after admission and their LOS after discharge. Anthropometric and biochemical parameters, related to nutrition status were analyzed, such as: weight, height, arm circumference (AC), waist circumference (WC), triceps skinfold thickness (TST), mild arm muscle circumference (MAMC), albumin (Alb) and hemoglobin (HB). Body mass index (BMI) was used to classify the nutritional status. All the nutritional factors except type of disease, gender and age were associated with LOS. The chi-square, Student-t, Mann-Whitney, Kruskal-Wallis and binary logistic multivariate tests were used in the statistical analyses. RESULTS: The majority of patients was male (53%), elderly (56%) and had neoplasm (19.4%). Undernutrition was higher in the elderly (p < 0.05) and neoplasm patients (p < 0.05), overweight or obese patients were more likely to suffer from cardiovascular diseases (p = 0.001). Average LOS was 14.7 days (± 12.5), longer in neoplasm patients (p < 0.05) and in elderly ones (p < 0.05), and also was 3 times longer in males (p < 0.0001). Among the nutritional parameters, patients with AC under 25 cm had higher LOS (p < 0.05), but only in women could it be considered a marker, increasing LOS 2.8 times. BMI less than 20 kg/m(2) increased LOS 2.1 times, and biochemical data (Alb and HB) do not contribute. In the multivariate analyses, male gender and TST depletion were the significant factors, which together best explained the lengths of hospital stay. CONCLUSION: LOS was associated with disease, gender, age and nutritional status. We can highlight two anthropometric analyses: first, AC can be used in women as a marker of longer LOS and second TST is the best overall predictor of longer hospital stay.

Estudo in vitro da atividade do extrato etanólico de sementes de bacupari (Rheedia gardneriana Planch. & Triana) e das frações no crescimento de Streptococcus mutans / In vitro study of the activity of ethanol extract from bacupari (Rheedia gardneriana Planch. & Triana) seeds and its fractions on Streptococcus mutans growth

Streptococcus mutans, principal microrganismo da cavidade oral, desempenha papel preponderante na formação de placas dentárias, sendo considerado o agente etiológico primário da cárie. Rheedia gardneriana, conhecida popularmente como bacupari, é uma planta utilizada com fins medicinais para o tratamento de diversas patologias, e por apresentar atividade antimicrobiana de compostos das folhas contra bactérias Gram-positivas e Gram-negativas. O objetivo do presente trabalho foi avaliar o efeito de extrato de semente de R. gardneriana sobre a cepa S. mutans UA159. Os testes foram conduzidos com o extrato etanólico bruto e as frações obtidas com os solventes diclorometano, etanol-água, metanol e hexano, em ensaios de inibição in vitro. O extrato bruto (100 por cento) apresentou halos de inibição com diâmetro similar ao obtido com solução de digluconato de clorexidina 0,12 por cento, usada como controle. Os ensaios com a fração diclorometano exibiram atividade inibitória 35 por cento menor comparado com o controle, enquanto nenhum efeito antimicrobiano foi observado com a fração etanol-água. Contrariamente, os resultados obtidos com as frações hexânica e metanólica demonstraram claramente a atividade antimicrobiana por inibição do crescimento bacteriano. Na fração metanólica a formação de halos de inibição foi similar ao do controle. Estes dados apresentam atividade antimicrobiana de R. gardneriana contra S. mutans.

Streptococcus mutans, which is the main microorganism of the oral cavity, plays a preponderant role in dental plaque formation and is considered the primary etiologic agent regarding caries. Commonly known as "bacupari", Rheedia gardneriana is a plant used for medicinal purposes in the treatment of several pathologies; besides, its leaves have compounds that present antimicrobial activity against Gram-positive and Gram-negative bacteria. The aim of this work was to evaluate the effect of R. gardneriana seed extract on S. mutans strain UA159. The tests were carried out with crude ethanol extract and the fractions obtained with the solvents dichloromethane, ethanol-water, methanol, and hexane in in vitro inhibition assays. The crude extract (100 percent) presented inhibition halos with diameter similar to that obtained by using 0.12 percent chlorhexidine digluconate solution as control. Assays with the fraction dichloromethane showed an inhibitory activity 35 percent lower than that of the control, whereas no antimicrobial effect was observed with the ethanol-water fraction. Conversely, the results obtained with the fractions hexane and methanol clearly demonstrated antimicrobial activity by inhibiting the bacterial growth. In the methanol fraction, the formation of inhibition halos was similar to that in the control. These data present antimicrobial activity of R. gardneriana against S. mutans.