Using data from a private provider of telemedicine to assess the severity of the early 2021 Covid-19 wave in Brazil.

In early 2021, Brazil saw a dramatic recurrence in Covid-19 cases associated to the spread of a novel variant of the SARS-CoV-2 virus, the P1 variant. In light of previous reports showing that this variant is more transmissible and more likely to infect people who had recovered from previous infection, a retrospective analysis was conducted to assess if the early 2021 Covid-19 wave in Brazil was associated with an increase in the number of individuals presenting with a more severe clinical course. Fifty-one thousand and fourteen individuals who underwent telemedicine consultations were divided into two groups: patients seen on or before January 31, 2021, and on or after February 1, 2021. These dates were chosen based on the spread of the P1 variant in Brazil. Referral to the emergency department (ED) was used as a marker of a more severe course of the disease. No differences were seen in the proportion of patients referred to the ED in each group nor in the odds ratio of being referred to the ED from the 1st of February 2021 (OR=0.909; 95%CI: 0.81-1.01). Considering the entire cohort, age had an impact on the odds of being referred to the ED, with individuals older than 59 years showing twice the risk of the remaining population and those less than 19 years showing a lower risk.

Using data from a private provider of telemedicine to assess the severity of the early 2021 Covid-19 wave in Brazil

In early 2021, Brazil saw a dramatic recurrence in Covid-19 cases associated to the spread of a novel variant of the SARS-CoV-2 virus, the P1 variant. In light of previous reports showing that this variant is more transmissible and more likely to infect people who had recovered from previous infection, a retrospective analysis was conducted to assess if the early 2021 Covid-19 wave in Brazil was associated with an increase in the number of individuals presenting with a more severe clinical course. Fifty-one thousand and fourteen individuals who underwent telemedicine consultations were divided into two groups: patients seen on or before January 31, 2021, and on or after February 1, 2021. These dates were chosen based on the spread of the P1 variant in Brazil. Referral to the emergency department (ED) was used as a marker of a more severe course of the disease. No differences were seen in the proportion of patients referred to the ED in each group nor in the odds ratio of being referred to the ED from the 1st of February 2021 (OR=0.909; 95%CI: 0.81-1.01). Considering the entire cohort, age had an impact on the odds of being referred to the ED, with individuals older than 59 years showing twice the risk of the remaining population and those less than 19 years showing a lower risk.

Ultrasound for the remediation of contaminated waters with persistent organic pollutants: A short review.

The rising amount of persistent organic contaminants released into water reservoirs in the last years became a cause of concern for the industry, academy, and public administration, due to their bioaccumulation, mutagenicity, and photosynthesis reduction. Therefore, the search for processes that efficiently remove such contaminants became of primary importance. In this context, ultrasound (US) is one of the most promising and economically viable alternatives to degrade organic pollutants in varied environments. Whereas the use of other advanced oxidation processes (AOPs), such as Fenton and photocatalysis, has been widely reported for this purpose, only a few papers deal with ultrasound application as a possible AOP. In this review, a general overview of ultrasound is provided, covering the last twenty years. It includes fundamental aspects of ultrasound and applications, individually or combined with other AOPs, to deplete organic pollutants from various classes in an aqueous environment. Finally, the review concludes by indicating that additional research should be conducted worldwide to explore the full potential of ultrasound as a useful AOP.

A Crystallographic Snapshot of SARS-CoV-2 Main Protease Maturation Process.

SARS-CoV-2 is the causative agent of COVID-19. The dimeric form of the viral Mpro is responsible for the cleavage of the viral polyprotein in 11 sites, including its own N and C-terminus. The lack of structural information for intermediary forms of Mpro is a setback for the understanding its self-maturation process. Herein, we used X-ray crystallography combined with biochemical data to characterize multiple forms of SARS-CoV-2 Mpro. For the immature form, we show that extra N-terminal residues caused conformational changes in the positioning of domain-three over the active site, hampering the dimerization and diminishing its activity. We propose that this form preludes the cis and trans-cleavage of N-terminal residues. Using fragment screening, we probe new cavities in this form which can be used to guide therapeutic development. Furthermore, we characterized a serine site-directed mutant of the Mpro bound to its endogenous N and C-terminal residues during dimeric association stage of the maturation process. We suggest this form is a transitional state during the C-terminal trans-cleavage. This data sheds light in the structural modifications of the SARS-CoV-2 main protease during its self-maturation process.

High dose brachytherapy with non sealed 188Re (rhenium) resin in patients with non-melanoma skin cancers (NMSCs): single center preliminary results.

BACKGROUND AND AIM: High dose brachytherapy using a non sealed 188Re-resin (Rhenium-SCT®, Oncobeta® GmbH, Munich, Germany) is a treatment option for non-melanoma skin cancer (NMSC). The aim of this prospective study was to assess the efficacy and the safety of a single application of Rhenium-SCT® in NMSC. MATERIALS AND METHOD: Fifty consecutive patients (15F, 35 M, range of age 56-97, mean 81) showing 60 histologically proven NMSCs were enrolled and treated with the Rhenium-SCT® between October 2017 and January 2020. Lesions were located on the face, ears, nose or scalp (n = 46), extremities (n = 9), and trunk (n = 5). Mean surface areas were 7.0 cm2 (1-36 cm2), mean thickness invasion was 1.1 mm (0.2-2.5 mm), and mean treatment time was 79 min (21-85 min). Superficial, mean, and target absorbed dose were 185 Gy, 63 Gy, and 31 Gy respectively. Patients were followed-up at 14, 30, 60, 90, and 180 days posttreatment, when dermoscopy and biopsy were performed. Mean follow-up was 20 months (range 3-33 months). Early skin toxicity was classified according to Common Terminology Criteria for Adverse Events (CTCAE). Cosmetic results were evaluated after at least 12 months according to Radiation Therapy Oncology Group (RTOG) scale. RESULTS: At 6 months follow-up, histology and dermoscopy were available for 54/60 lesions, of which 53/54 (98%) completely responded. One patient showed a 1-cm2 residual lesion that was subsequently surgically excised. Twelve months after treatment, 41/41 evaluable lesions were free from relapse. Twenty four months after treatment, 23/24 evaluable lesions were free of relapse. In 56/60 lesions early side effects, resolving within 32 days were classified as grades 1-2 (CTCAE). In the remaining 4/60 lesions, these findings were classified as grade 3 (CTCAE) and lasted up to 8-12 weeks but all resolved within 90 days. After at least 12 months (12-33 months), cosmetic results were excellent (30 lesions) or good (11 lesions). CONCLUSION: High dose brachytherapy with Rhenium-SCT® is a noninvasive, reasonably safe, easy to perform, effective and well-tolerated approach to treat NMSCs, and it seems to be a useful alternative option when surgery or radiation therapy are difficult to perform or not recommended. In our population 98% of the treated lesions resolved completely after a single application and only one relapsed after 2 years. Larger patients' population and longer follow-up are needed to confirm these preliminary data and to find the optimal dose to administer in order to achieve complete response without significant side effects.

Molecular characterization and evaluation of virulence traits of Aeromonas spp. isolated from the tambaqui fish (Colossoma macropomum).

The present study was developed to characterize, at the species level, 34 strains of Aeromonas spp., previously isolated from stressed tambaqui fish (Colossoma macropomum), to elucidate virulence factors, as well as their antibiotic resistance profile. Amplification of the gyrB gene identified the strains as A. hydrophila, A. dhakensis, A. caviae, A. veronii and A. jandaei. Bacterial virulence was evaluated by enzymatic assays for phenotypical production of hemolysins, proteases and lipases followed by the search for genes codifying the enzymes ß-hemolysin, serine protease and lipase. Phenotypical production of virulence factors was diversified and proteolytic activity demonstrated to be a common expression among the strains. On the other hand, the lip gene encoding extracellular lipase was the most expressed. Furthermore, A. hydrophila was the most prevalent species isolated from tambaqui in our work.

Critical overview of the main features and techniques used for the evaluation of the clinical applicability of L-asparaginase as a biopharmaceutical to treat blood cancer.

L-asparaginase is an enzyme used as a biopharmaceutical to treat acute lymphoblastic leukemia. Several adverse effects have been related to L-asparaginase use, so the scientific community has searched for novel proteoforms of L-ASNase. However, some critical characteristics must be considered for a novel L-ASNase source to be effective as an antitumour drug. Accordingly, this article provides a critical analysis of the parameters and methods applied to estimate L-ASNase concentration, measure the L-ASNase and GLNase activities and kinetics, evaluate the enzyme preparations purity and define the antitumour activity against leukemic cells in vitro. Among the main features, the proposed new enzyme needs to present high affinity for L-asparagine; low percentage of glutaminase activity in relation to L-ASNase; high enzyme stability and half-life and mainly antileukemic activity when a low protein amount is applied. These parameters are discussed in an attempt to guide the consideration of an enzyme as a promising biopharmaceutical against ALL.

Screening and optimizing fermentation production of l-asparaginase by Aspergillus terreus strain S-18 isolated from the Brazilian Caatinga Biome.

AIMS: The aim of this study was to find new eukaryotic sources of the l-asparaginase (l-ASNase), since the prokaryotic sources of the enzyme are well-reported as causing allergic hypersensitivity reactions in a significant number of patients. This report describes screening for l-ASNase production by filamentous fungi isolated from the Brazilian Caatinga, and the optimization of fermentation parameters to increase fungal growth and improve yield in the production of l-ASNase. METHODS AND RESULTS: Thirty-two filamentous fungi were investigated in this study. When Aspergillus terreus strain S-18 was cultured in a proline-enriched medium, intracellular l-ASNase was expressed in concurrence with reduced l-glutaminase (l-GLUase) and protease activities. Fermentation conditions were then optimized in a 5-l bioreactor system to produce a maximum volumetric yield of 108 U total of l-ASNase activity. CONCLUSIONS: The work reported here represents the first attempt to produce l-ASNase by filamentous fungi isolated from Brazil and offers a promising alternative eukaryotic source for l-ASNase production. SIGNIFICANCE AND IMPACT OF THE STUDY: In order to minimize the side effects caused by bacterial l-ASNase, the search of eukaryotic micro-organism for l-ASNase was carried out in fungi. This study demonstrates the diversity of filamentous fungi isolated from the Brazilian Caatinga Biome and the importance of knowledge of the microbial metabolism to obtain high concentrations of biotechnological products.

Air and moisture stable covalently-bonded tin(ii) coordination polymers.

Four covalently-bonded tin(ii) coordination polymers, (1)-(4), were hydrothermally prepared in aqueous alkaline media by the reactions of SnSO4 with 1,2,4,5-benzenetetracarboxylic acid (1), 1,3,5-benzenetricarboxylic acid (2), 4-hydroxypyridine-2,6-dicarboxylic acid (3), and 1,3,5-cyclohexanetricarboxylic acid (4). All products were structurally authenticated by single-crystal X-ray diffraction, and the number of different tin centres and their oxidation states were confirmed by 119Sn Mössbauer spectroscopy. In addition, the comparison between experimental and simulated X-ray powder diffraction patterns confirmed the authenticity of the samples. Our crystallographic results for (1)-(4) show that the Sn(ii) centres are tetracoordinated and exhibit distorted disphenoidal geometries, corroborating the presence of one stereochemically active lone electron pair at each metal site. Products (1) and (2) display bi-dimensional polymeric structures, (3) exhibits a one-dimensional architecture, whereas (4) shows a remarkable three-dimensional coordination network. Hirshfeld surface and supramolecular analyses for the repeating units of (1)-(4) were also performed in order to identify structurally important non-covalent interactions.

Low dose radiation 18F-fluoride PET/CT in the assessment of Unilateral Condylar Hyperplasia of the mandible: preliminary results of a single centre experience.

BACKGROUND: Unilateral condylar hyperplasia (UCH) of the mandible, or Hypercondylia, is a pathological condition that determines an abnormal growth of the affected condyle.Bone SPECT with Tc99m-diphosphonates is a successful tool in the diagnosis of UCH. EANM guidelines also suggest the use of 18F-NaF PET/CT, though it leads to a higher radiation exposure. AIM: As UCH patients are young, we aimed to develop a low dose 18F-Fluoride PET/CT protocol and compare it to a standard injected activity scan, to assess if the image quality remains unchanged. MATERIALS AND METHODS: We prospectively enrolled 20 patients (7 males, 13 females, mean age 23.2) with UCH, who underwent 18F-NaF PET/CT to assess the hypercondylia. We administered a low activity of 18F-NaF (2.9 MBq/kg) in 15 patients and a standard activity (5.3 MBq/kg) in 5 patients. Activity range was chosen according to 2015 EANM guidelines.To determine if the scans with low radiotracer activity were "diagnostic" such as those with standard activity, two expert nuclear medicine physicians, unaware of the administered activity, independently reviewed the scans and expressed a final qualitative judgment in terms of "diagnostic"/"non-diagnostic" scan. Furthermore, we compared the effective dose of a low injected activity PET/CT to the standard one and to a Bone SPECT performed with standard injected activity of Tc99m-diphosphonates. RESULTS: Reviewers classified 19 of 20 scans as "diagnostic". Only one of them was classified as "non diagnostic" due to condylar arthrosis that disturbed the correct evaluation of condylar radiotracer uptake. The effective dose of a 18F-Fluoride PET/CT, in patient of 70 kg, is about 3.5 mSv in scans performed with 2.9 MBq/kg [0.017 mSv/MBq × 2.9 MBq/kg × 70 kg] and about 6.3 mSv in ones performed with 5.3 MBq/kg [0.017 mSv/MBq × 5.3 MBq/kg × 70 kg]. The effective dose of 99mTc-MDP bone SPECT is about 3.2 mSv [0.0043 mSv/MBq × 740 MBq of 99mTc-MDP]. DISCUSSION: 18F-NaF PET/CT performed with a low radiotracer activity allows a good assessment of UCH similar to that performed with an ordinary activity. The effective radiation dose of a low-injected activity PET/CT is significantly lower than an ordinary-injected activity and is not significantly higher than the most used Bone SPECT. Moreover PET/CT is performed in 1.5 h while Bone SPECT requires at least 3.5 h. CONCLUSIONS: The 18F-Fluoride PET/CT procedure could be performed with 2.9 MBq/Kg (minimum 185 MBq, recommended at least 200 MBq) of 18F-NaF to minimize the effective radiation dose received, maintaining the quality of the scan. Further studies including a larger number of patients and clinical follow-up are needed to confirm our preliminary findings.

Molecular identification and physiological characterization of Zymomonas mobilis strains from fuel-ethanol production plants in north-east Brazil.

Zymomonas mobilis has long attracted attention owing to its capacity to ferment hexose to ethanol. From a taxonomic viewpoint, Z. mobilis is a unique species of the genus Zymomonas, separated into three subspecies, Z. mobilis subsp. mobilis, Z. mobilis subsp. pomaceae and Z. mobilis subsp. francensis on the basis of physiological tests, which are often unreliable owing to the genetic proximity among these species. Currently, the use of molecular techniques is more appropriate for identification of these bacterial subspecies. In this study, the 32 strains of Z. mobilis present in the UFPEDA bacterial collection were characterized using molecular techniques, such as sequencing of the 16S rDNA gene and its theoretical restriction profile, classifying them as members of the subspecies, Z. mobilis subsp. mobilis. In addition, anaerobic cultivations were performed, which showed the biological diversity of the strains in terms of growth, sugar consumption and ethanol production. From these results, it was possible to identify the strain Z-2-80 as a promising bacterium for use in the fermentation process. SIGNIFICANCE AND IMPACT OF THE STUDY: Zymomonas mobilis is a bacterium of great relevance to biotechnology, owing to its capacity to ferment hexose to ethanol. On a molecular basis, 32 isolates were identified as Z. mobilis subsp. mobilis. However, intraspecific diversity was identified when these were grown under strictly anaerobic conditions. The results obtained from this study suggest a strain of Z. mobilis as an alternative for use in the fermentation process.

L-asparaginase isolated from Streptomyces ansochromogenes promotes Th1 profile and activates CD8+ T cells in human PBMC: an in vitro investigation.

AIMS: A new L-asparaginase produced by Streptomyces ansochromogenes UFPEDA 3420 actinobacteria was used in this study against human lymphocyte cultures to evaluate the immunological profile induced by this enzyme. METHODS AND RESULTS: Cultures of lymphocytes were stimulated with S. ansochromogenes L-asparaginase, and cytotoxicity, cell viability, cell stimulation and cytokine production were analysed. This new S. ansochromogenes L-asparaginase induced activation and proliferation of the TCD8+ lymphocyte subset and produced higher TNF-α, IFN-γ, IL-2 and IL-10 levels in a 24-h assay. CONCLUSION: Streptomyces ansochromogenes L-asparaginase is a promising molecule to be used in in vivo models and to deepen preclinical tests against acute lymphoblast leukaemia. SIGNIFICANCE AND IMPACT OF STUDY: L-asparaginase is an indispensable component of the chemotherapeutic treatment of acute lymphoblast leukaemia (ALL) and acute myeloid leukaemia (AML). Currently, drugs such as Asparaginase® , Kidrolase® , and Elspar® and Erwinase® are efficient against leukemic disease, but promote immunosuppression and other side effects in human organisms. Our purified S. ansochromogenes L-asparaginase showed promissory results inducing, in vitro, higher immunostimulation in human PBMC, especially in T CD8+ lymphocyte subsets.

Produção e caracterização de protease fibrinolítica de Streptomyces parvulus DPUA 1573 / Production and characterization of fibrinolytic protease from Streptomyces parvulus DPUA 1573

As proteases fibrinolíticas são capazes de degradar coágulos de fibrina formados dentro dos vasos sanguíneos, evitando a trombose intravascular. Em animais, a tromboflebite, que acomete frequentemente os equinos, ocasiona, em seus casos graves, a obstrução jugular e também um edema de laringe, derivando a obstrução das vias aéreas, o que possibilita um edema cerebral, ocorrendo o óbito do animal. Devido ao fato de o tratamento ser de custo elevado, faz-se necessária a investigação de outras fontesde proteases fibrinolíticas com custos menores e com menos efeitos colaterais. Diante disso, este estudo tem como objetivo produzir e caracterizar proteases fibrinolíticas obtidas de Streptomyces parvulus DPUA 1573. Para produção da enzima, foi utilizado um planejamento fatorial 24 avaliando a concentração da farinha de soja (0,5, 1,0 e 1,5%) e da glicose (0, 0,5 e 1,0g/L), temperatura (28, 32 e 37ºC) e agitação (150, 200 e 250rpm) sobre a biomassa e a atividade fibrinolítica. Pode-se verificar que a protease fibrinolítica apresentou atividade máxima (835U/mL) nas condições de concentração de 1,5% de soja, 1g/L de glicose, 28°C e 150rpm com 48 horas de fermentação. A protease fibrinolítica obtida teve temperatura e pH ótimos de 55°C e pH 9,0, respectivamente. A atividade enzimática foi inibida pelo EDTA, pelo íon Fe2+ e pelo SDS, o que indicou a enzima ser uma metaloprotease. A linhagem Streptomyces parvulus DPUA 1573 foi capaz de produzir protease fibrinolítica, possuindo características bioquímicas favoráveis à aplicação na medicina veterinária e possivelmente humana.(AU)

Fibrinolytic proteases are able to degrade fibrin clot formed in the blood vessel, avoiding intravascular thrombosis. In animals, thrombophlebitis often affects horses, and in severe cases causes obstruction of the jugular and laryngeal edema leading to airway obstruction allowing cerebral edema resulting in the death of the animal. Since treatment is costly, the investigation of other sources of fibrinolytic proteases at lower cost and with fewer side effects is needed. Thus, this study aims to produce and characterize fibrinolytic proteases from Streptomyces parvulus DPUA 1573. For enzyme production, a factorial design was performed to evaluate 24 soybean flour concentration (0.5, 1.0 and 1.5%) and glucose (0, 0.5 and 1.0g/L), temperature (28, 32 and 37°C) and agitation (150, 200 and 250rpm) on biomass and fibrinolytic activity. Fibrinolytic protease showed maximum activity (835 U/mL) under these conditions: 1.5% soybean flour, 1g/L glucose, 28°C, and 150rpm 48 hours of fermentation. The optimal temperature was 55°C and optimal pH was 9.0. Fibrinolytic protease activity was inhibited by EDTA, the ion Fe2+, and by SDS, which indicated that the enzyme is a metallo-protease. The strain Streptomyces parvulus DPUA 1573 was able to produce fibrinolytic protease with biochemical characteristics favorable for application in veterinary and human medicine.(AU)

Interpretation of 11C-choline PET/CT for the diagnosis of local relapse in radically treated prostate cancer.

PURPOSE: 11C-choline PET/CT is a widely-used tool for the diagnostic of prostate cancer (PCa). In literature, a great variability of local relapse (LR) detection rate is reported. The aim of this study is to provide positivity criteria for 11C-choline PET/CT detection of LR in patients who had surgery for PCa and presented prostate specific antigen (PSA) failure. METHODS: Sixty patients radically treated for PCa and presenting PSA failure were retrospectively analysed. Two Nuclear Medicine Physicians revised the 11C-choline PET/CT scans and defined by consensus if even mild focal uptake was present in the prostate bed (PB) and bladder-urethral junction (BUJ) along midline, regardless the previous report results.The results were subsequently correlated with a clinical and radiological follow up (FU) of 1 to 2 year and with TNM staging, Gleason score (GS), PSA level at relapse, radiotherapy (RT) and hormone therapy (HT) after surgery. RESULTS: There was focal uptake in 22/60 patients; 11 of them were true positive and 11 false positive. The PSA level showed a tight connection with the true positivity/negativity of Choline scan. Most of true positive cases (10/11 patients) presented a PSA ≥ 1 ng/ml, while approximately half of the false positive cases (5/11 patients) presented PSA below 1 ng/ml. The other variables were not correlated to Choline detection rate for LR. CONCLUSIONS: This study shows that an even mild focal uptake of Choline in the PB and BUJ along midline must be considered suspicious for LR in patients radically treated for PCa, especially if they are presenting with PSA level > 1 ng/ml.

18F-FDG PET/CT scan confirmed by pathology findings in a singular case of squamous cell carcinoma of the epiglottis.

BACKGROUND: Only about 1% of all head and neck lateral or paramedian cancers described in the scientific literature shows, in staging, contralateral cervical adenopathy without ipsilateral pathological involvement of lymph nodes. CASE PRESENTATION: This case is one of them, in which 18F-FDG PET/CT scan is confirmed by pathology findings, and has correctly identified all metastatic disease foci. CONCLUSIONS: To date, PET/CT is not recommended in head and neck cancer staging. However, the use of PET/CT in head and neck cancer staging can define possible metastatic disease foci, clarify c.e. CT suspicious findings and, in some cases, change the TNM stage, with a strong prognostic and therapeutic impact.

Phytoplankton composition of the water and gastrointestinal tract of the mussel Diplodon enno (Ortmann, 1921) from São Francisco river (Bahia, Brazil) / Composição fitoplanctônica da água e do trato gastrointestinal do molusco Diplodon enno (Ortmann) do rio São Francisco (BA - Brasil)

Abstract The knowledge on diet composition of the freshwater mussel Diplodon enno (Ortmann) would aid in its culture and propagation allowing, this way, the replacement of natural endangered populations in Brazil. Microalgae are the main food source for captive mussels and unionids have displayed an ability to sort algae based on the cellular characteristics prior to ingestion. The main objective of the present work is to analyze the phytoplankton composition of the water from and of the gastrointestinal contents of the mussel D. enno, as an initial step for development of a suitable rearing diet. Therefore, water samples and bivalve specimens were collected from S. Francisco River, city of Paulo Afonso, Bahia, Brazil. The microalgal composition found in water and stomach/gut content samples was very diverse being represented by the following divisions: Cyanophyta, Chlorophyta, Dinophyta and Heterokontophyta (Diatoms). Concerning the relative abundance of microalgae divisions, it is possible to state, for the water and gastrointestinal contents, that Cyanophyta represents 15% and 14%, Chlorophyta 54% in both, Heterokontophyta 31% and 27% and Dinophyta 0% and 5%, respectively. According to the Brazilian CETESB criteria for phytoplankton species classification, 50% of Cyanophyta and 15% of Chlorophyta species observed in the water samples were classified as “very frequent”, as were 68% of Heterokontophyta and 33% of Chlorophyta species in the gut/stomach tract samples. Focusing at a species level, although in the water only Coelastrum sp. and Chroococcus sp. were observed in 100% and 75% of the samples, respectively, in the gastrointestinal tract the species Staurastrum sp., Aulacoseira sp., Scenedesmus sp. and Fragilaria crotonensis occurred in 80% to 100% of the samples. The present results showed that D. enno feeds not only on small chlorophytes microalgae, due to their convenient size that facilitates higher feeding rates, but also on large size diatoms, due to a possible nutritional advantage for the bivalves. Thus, a diet composed by large diatoms and small chlorophytes microalgae may be considered as the most reasonable for the maintenance of D. enno populations.

Resumo O conhecimento da composição da dieta do molusco de água doce Diplodon enno é de extrema importância para a sua cultura e propagação, permitindo desta forma a recuperação de populações em perigo de extinção no Brasil. As microalgas são a principal fonte de alimento para moluscos filtradores e os uniónidos sendo selecionadas por estes com base nas suas características celulares. O principal objectivo deste trabalho é analisar a composição fitoplanctônica da água e do conteúdo gastrointestinal do molusco D. enno, de forma a desenvolver uma dieta apropriada ao seu cultivo. Para isso, amostras de água e espécimes de bivalves foram recolhidos do rio São Francisco, cidade de Paulo Afonso, Bahia, Brasil. A composição de microalgas encontrada na água e no conteúdo do estômago/intestino foi muito diversa, sendo representada pelas seguintes divisões: Cyanophyta, Chlorophyta, Dinophyta e Heterokontophyta (diatomáceas). Atendendo à abundância relativa de cada divisão de microalgas, podemos afirmar que na água e no trato gastrointestinal Cyanophyta representa 15% e 14%, Chlorophyta 54% em ambos, Heterokontophyta 31% e 27% e Dinophyta 0% and 5%, respectivamente. De acordo com o critério CETESB de classificação de espécies de fitoplâncton, 50% das espécies de Cyanophyta e 15% das de Chlorophyta observadas nas amostras de água foram classificadas como “muito frequentes”, tal como aconteceu para 68% das espécies de Heterokontophyta e 33% das de Chlorophyta nas amostras do conteúdo do trato gastrointestinal. Realçando as espécies presentes, apesar de apenas Coelastrum sp. e Chroococcus sp. terem sido observadas em 100% e 75% das amostras de água, respectivamente, nas amostras de trato gastrointestinal Staurastrum sp., Aulacoseira sp., Scenedesmus sp. e Fragilaria crotonensis foram identificadas em entre 80% e 100% das amostras. Os resultados deste estudo mostram que D. enno se alimenta não apenas de pequenas microalgas clorófitas, devido ao seu pequeno tamanho que possibilita maiores taxas de filtração, como também de diatomáceas maiores, devido a uma possível vantagem nutricional para os bivalves. Assim sendo, uma dieta composta por diatomáceas e pequenas clorófitas poderá ser considerada a mais indicada para a manutenção de populações de D. enno.

Antimicrobial potential of actinobacteria isolated from the rhizosphere of the Caatinga biome plant Caesalpinia pyramidalis Tul.

Actinobacteria are known to produce various secondary metabolites having antibiotic effects. This study assessed the antimicrobial potential of actinobacteria isolated from the rhizosphere of Caesalpinia pyramidalis Tul. from the Caatinga biome. Sixty-eight actinobacteria isolates were evaluated for antimicrobial activity against different microorganisms by disk diffusion and submerged fermentation, using different culture media, followed by determination of minimum inhibitory concentration (MIC) and chemical prospecting of the crude extract. Of the isolates studied, 52.9% of those isolated at 37°C and 47.05% of those isolated at 45°C had activity against Bacillus subtilis, Staphylococcus aureus, methicillin-resistant S. aureus (MRSA), Fusarium moniliforme, and Candida albicans. When compared with others actinobacteria, the isolate C1.129 stood out with better activity and was identified by 16S rDNA gene analysis as Streptomyces parvulus. The crude ethanol extract showed an MIC of 0.97 µg/mL for MRSA and B. subtilis, while the ethyl acetate extract showed MIC of 3.9 µg/mL for S. aureus and MRSA, showing the greatest potential among the metabolites produced. Chemical prospecting revealed the presence of mono/sesquiterpenes, proanthocyanidin, triterpenes, and steroids in both crude extracts. This study evaluates S. parvulus activity against multi-resistant microorganisms such as MRSA. Thus, it proves that low-fertility soil, as is found in the Caatinga, may contain important microorganisms for the development of new antimicrobial drugs.

Phytoplankton composition of the water and gastrointestinal tract of the mussel Diplodon enno (Ortmann, 1921) from São Francisco river (Bahia, Brazil).

The knowledge on diet composition of the freshwater mussel Diplodon enno (Ortmann) would aid in its culture and propagation allowing, this way, the replacement of natural endangered populations in Brazil. Microalgae are the main food source for captive mussels and unionids have displayed an ability to sort algae based on the cellular characteristics prior to ingestion. The main objective of the present work is to analyze the phytoplankton composition of the water from and of the gastrointestinal contents of the mussel D. enno, as an initial step for development of a suitable rearing diet. Therefore, water samples and bivalve specimens were collected from S. Francisco River, city of Paulo Afonso, Bahia, Brazil. The microalgal composition found in water and stomach/gut content samples was very diverse being represented by the following divisions: Cyanophyta, Chlorophyta, Dinophyta and Heterokontophyta (Diatoms). Concerning the relative abundance of microalgae divisions, it is possible to state, for the water and gastrointestinal contents, that Cyanophyta represents 15% and 14%, Chlorophyta 54% in both, Heterokontophyta 31% and 27% and Dinophyta 0% and 5%, respectively. According to the Brazilian CETESB criteria for phytoplankton species classification, 50% of Cyanophyta and 15% of Chlorophyta species observed in the water samples were classified as "very frequent", as were 68% of Heterokontophyta and 33% of Chlorophyta species in the gut/stomach tract samples. Focusing at a species level, although in the water only Coelastrum sp. and Chroococcus sp. were observed in 100% and 75% of the samples, respectively, in the gastrointestinal tract the species Staurastrum sp., Aulacoseira sp., Scenedesmus sp. and Fragilaria crotonensis occurred in 80% to 100% of the samples. The present results showed that D. enno feeds not only on small chlorophytes microalgae, due to their convenient size that facilitates higher feeding rates, but also on large size diatoms, due to a possible nutritional advantage for the bivalves. Thus, a diet composed by large diatoms and small chlorophytes microalgae may be considered as the most reasonable for the maintenance of D. enno populations.

The effect of an inhibitor of gut serotonin (LP533401) during the induction of periodontal disease.

BACKGROUND AND OBJECTIVE: LP533401 is an inhibitor of tryptophan hydroxylase 1, which regulates serotonin production in the gut. Previous work indicates that LP533401 has an anabolic effect in bone. Thus, we hypothesized that inhibition of gut serotonin production may modulate the host response in periodontal disease. In this study, we aimed to analyze the effects of LP533401 in a rat periodontitis model to evaluate the role of gut serotonin in periodontitis pathophysiology. MATERIAL AND METHODS: Twenty-four rats were divided into three groups: treated group (T: ligature-induced periodontal disease and LP533401, 25 mg/kg/d) by gavage; ligature group (L: ligature-induced periodontal disease only); and control group (C: without ligature-induced periodontal disease). After 28 d, radiographic alveolar bone support was measured on digital radiographs, and alveolar bone volume fraction, tissue mineral density and trabeculae characteristics were quantified by microcomputed tomography in the right hemi-mandible. Left hemi-mandibles were decalcified and alveolar bone loss, attachment loss and area of collagen in the gingiva were histologically analyzed. RESULTS: Significant difference between the L and C groups was found, confirming that periodontal disease was induced. We observed no difference between the T and L groups regarding alveolar bone destruction and area of collagen. CONCLUSION: LP533401 (25 mg/kg/d) for 28 d does not prevent bone loss and does not modulate host response in a rat model of induced periodontal disease.