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Ergosterol isolated from the basidiomycete Pleurotus salmoneostramineus affects Trypanosoma cruzi plasma membrane and mitochondria
No full textAbstract\ud
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Background\ud
Major drawbacks of the available treatment against Chagas disease (American trypanosomiasis) include its toxicity and therapeutic inefficiency in the chronic phase of the infection, which makes it a concern among neglected diseases. Therefore, the discovery of alternative drugs for treating chronic Chagas disease requires immediate action. In this work, we evaluated the mushroom Pleurotus salmoneostramineus in the search for potential antiparasitic compounds.\ud
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Methods\ud
Fruit bodies of the basidiomycete Pleurotus salmoneostramineus were triturated and submitted to organic solvent extraction. After liquid-liquid partition of the crude extract, three fractions were obtained and the bioguided fractionation study was conducted to isolate the active metabolites. The elucidation of the chemical structure was performed using GC-MS and NMR techniques. The biological assays for antiparasitic activity were carried out using trypomastigotes of Trypanosoma cruzi and murine macrophages for mammalian cytotoxicity. The mechanism of action of the isolated compound used different fluorescent probes to evaluate the plasma membrane permeability, the potential of the mitochondrial membrane and the intracellular levels of reactive oxygen species (ROS).\ud
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Results\ud
The most abundant fraction showing the antiparasitic activity was isolated and chemically elucidated, confirming the presence of ergosterol. It showed anti-Trypanosoma cruzi activity against trypomastigotes, with an IC50 value of 51.3 μg/mL. The compound demonstrated no cytotoxicity against mammalian cells to the maximal tested concentration of 200 μg/mL. The mechanism of action of ergosterol in Trypanosoma cruzi trypomastigotes resulted in permeabilization of the plasma membrane, as well as depolarization of mitochondrial membrane potential, leading to parasite death. Nevertheless, no increase in ROS levels could be observed, suggesting damages to plasma membrane rather than an induction of oxidative stress in the parasite.\ud
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Conclusions\ud
The selection of naturally antiparasitic secondary metabolites in basidiomycetes, such as ergosterol, may provide potential scaffolds for drug design studies against neglected diseases.This work was supported by grants from São Paulo State Research\ud
Foundation (FAPESP 2013/50228-8, 2016/24985-4) and scholarships from\ud
CAPES
Combined effect of pulse density and grid cell size on predicting and mapping aboveground carbon in fast-growing Eucalyptus forest plantation using airborne LiDAR data
No full textAbstract\ud
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Background\ud
LiDAR remote sensing is a rapidly evolving technology for quantifying a variety of forest attributes, including aboveground carbon (AGC). Pulse density influences the acquisition cost of LiDAR, and grid cell size influences AGC prediction using plot-based methods; however, little work has evaluated the effects of LiDAR pulse density and cell size for predicting and mapping AGC in fast-growing Eucalyptus forest plantations. The aim of this study was to evaluate the effect of LiDAR pulse density and grid cell size on AGC prediction accuracy at plot and stand-levels using airborne LiDAR and field data. We used the Random Forest (RF) machine learning algorithm to model AGC using LiDAR-derived metrics from LiDAR collections of 5 and 10 pulses m−2 (RF5 and RF10) and grid cell sizes of 5, 10, 15 and 20 m.\ud
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Results\ud
The results show that LiDAR pulse density of 5 pulses m−2 provides metrics with similar prediction accuracy for AGC as when using a dataset with 10 pulses m−2 in these fast-growing plantations. Relative root mean square errors (RMSEs) for the RF5 and RF10 were 6.14 and 6.01%, respectively. Equivalence tests showed that the predicted AGC from the training and validation models were equivalent to the observed AGC measurements. The grid cell sizes for mapping ranging from 5 to 20 also did not significantly affect the prediction accuracy of AGC at stand level in this system.\ud
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Conclusion\ud
LiDAR measurements can be used to predict and map AGC across variable-age Eucalyptus plantations with adequate levels of precision and accuracy using 5 pulses m−2 and a grid cell size of 5 m. The promising results for AGC modeling in this study will allow for greater confidence in comparing AGC estimates with varying LiDAR sampling densities for Eucalyptus plantations and assist in decision making towards more cost effective and efficient forest inventory.This research was funded through a Ph.D. scholarship from the National\ud
Council of Technological and Scientifc Development - CNPq via the Science\ud
Without Borders Program (Process 249802/2013-9) and by the State of São\ud
Paulo Research Foundation-FAPESP (Process 12/03176-0)
Evidence of endometrial amino acid metabolism and transport modulation by peri-ovulatory endocrine profiles driving uterine receptivity
No full textAbstract\ud
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Background\ud
In beef cattle, changes in the periovulatory endocrine milieu are associated with fertility and conceptus growth. A large preovulatory follicle (POF) and the resulting elevated concentrations of progesterone (P4) during diestrus positively affect pregnancy rates. Amino acids (AA) are important components of maternally derived secretions that are crucial for embryonic survival before implantation. The hypothesis is that the size of the POF and the concentration of P4 in early diestrus modulate the endometrial abundance of SLC transcripts related to AA transport and metabolism and subsequently impact luminal concentrations of AA. The follicle growth of Nelore cows was manipulated to produce two experimental groups: large POF and CL (LF-LCL group) and small POF and CL (SF-SCL group). On Day 4 (D4; Experiment 1) and Day 7 (D7; Experiment 2) after GnRH-induced ovulation (GnRH treatment = D0), the animals were slaughtered and uterine tissues and uterine washings were collected. qRT-PCR was used to evaluate the expression levels of AA transporters in D4 and D7 endometrial tissues. The concentrations of AA were quantified in D4 and D7 uterine washings by HPLC.\ud
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Results\ud
Transcript results show that, on D4, SLC6A6, SLC7A4, SLC17A5, SLC38A1, SLC38A7 and SCLY and on D7 SLC1A4, SLC6A1, SLC6A14, SLC7A4, SLC7A7, SLC7A8, SLC17A5, SLC38A1, SLC38A7, SLC43A2 and DDO were more abundant in the endometria of cows from the LF-LCL group (P < 0.05). In addition, concentrations of AA in the uterine lumen were influenced by the endocrine profiles of the mother. In this context, D4 uterine washings revealed that greater concentrations of taurine, alanine and α-aminobutyric acid were present in SF-SCL (P < 0.05). In contrast, lower concentrations of valine and cystathionine were quantified on D7 uterine washings from SF-SCL cows (P < 0.05).\ud
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Conclusion\ud
The present study revealed an association between the abundance of transcripts related to AA transport and metabolism in the endometrium and specific periovulatory endocrine profiles related to the receptive status of the mother. Such insights suggest that AAs are involved in uterine function to support embryo development.FAPESP 2014/01727-4 to MISS\ud
CNPq- 481199/2012-8 and FAPESP- 2011/03226-4 to MB\ud
CNPq 140527/2013-3 to MRF\ud
The funding bodies had no participation on the study, collection, analysis,\ud
interpretation of data nor in writing the manuscript
Limitation of cellulose accessibility and unproductive binding of cellulases by pretreated sugarcane bagasse lignin
No full textAbstract\ud
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Background\ud
The effectiveness of the enzymatic hydrolysis of cellulose in plant cell wall is strongly influenced by the access of enzymes to cellulose, which is at least in part limited by the presence of lignin. Although physicochemical treatments preceding the enzymatic catalysis significantly overcome this recalcitrance, the residual lignin can still play a role in the process. Lignin is suggested to act as a barrier, hindering cellulose and limiting the access of the enzymes. It can also unspecifically bind cellulases, reducing the amount of enzymes available to act on cellulose. However, the limiting role of the lignin present in pretreated sugarcane bagasses has not been fully understood yet.\ud
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Results\ud
A set of sugarcane bagasses pretreated by five leading pretreatment technologies was created and used to assess their accessibility and the unproductive binding capacity of the resulting lignins. Steam explosion and alkaline sulfite pretreatments resulted in more accessible substrates, with approximately 90% of the cellulose hydrolyzed using high enzyme loadings. Enzymatic hydrolysis of alkaline-treated (NaOH) and steam-exploded sugarcane bagasses were strongly affected by unproductive binding at the lowest enzyme loading tested. Analysis of the extracted lignins confirmed the superior binding capacity of these lignins. Sulfite-based pretreatments (alkaline sulfite and acid sulfite) resulted in lignins with lower binding capacities compared to the analogue pretreatments without sulfite (alkaline and acidic). Strong acid groups present in sulfite-based pretreated substrates, attributed to sulfonated lignins, corroborated the lower binding capacities of the lignin present in these substrates. A more advanced enzyme preparation (Cellic CTec3) was shown to be less affected by unproductive binding at low enzyme loading.\ud
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Conclusions\ud
Pretreatments that increase the accessibility and modify the lignin are necessary in order to decrease the protein binding capacity. The search for the called weak lignin-binding enzymes is of major importance if hydrolysis with low enzyme loadings is the goal for economically viable processes.The authors thank José M. Silva and José C. Tavares for technical assistance,\ud
Richard Chandra for the valuable scientifc discussions, and Sarah Teter\ud
(Novozymes) for providing Cellic CTec3. This work was supported by FAPESP\ud
(Contract Numbers 08/56256-5 and 14/06923-6), CNPq, and CAPES. Germano\ud
Siqueira thanks CAPES, FAPESP (Contract Number 12/09940-3), and CNPq for\ud
his student fellowships
Muscle force distribution of the lower limbs during walking in diabetic individuals with and without polyneuropathy
No full textAbstract\ud
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Background\ud
Muscle force estimation could advance the comprehension of the neuromuscular strategies that diabetic patients adopt to preserve walking ability, which guarantees their independence as they deal with their neural and muscular impairments due to diabetes and neuropathy. In this study, the lower limb’s muscle force distribution during gait was estimated and compared in diabetic patients with and without polyneuropathy.\ud
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Methods\ud
Thirty individuals were evaluated in a cross-sectional study, equally divided among controls (CG) and diabetic patients with (DNG) and without (DG) polyneuropathy. The acquired ground reaction forces and kinematic data were used as input variables for a scaled musculoskeletal model in the OpenSim software. The maximum isometric force of the ankle extensors and flexors was reduced in the model of DNG by 30% and 20%, respectively. The muscle force was calculated using static optimization, and peak forces were compared among groups (flexors and extensors of hip, knee, and ankle; ankle evertors; and hip abductors) using MANOVAs, followed by univariate ANOVAs and Newman-Keuls post-hoc tests (p < 0.05).\ud
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Results\ud
From the middle to late stance phase, DG showed a lower soleus muscle peak force compared to the CG (p=0.024) and the DNG showed lower forces in the gastrocnemius medialis compared to the DG (p=0.037). At the terminal swing phase, the semitendinosus and semimembranosus peak forces showed lower values in the DG compared to the CG and DNG. At the late stance, the DNG showed a higher peak force in the biceps short head, semimembranosus, and semitendinosus compared to the CG and DG.\ud
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Conclusion\ud
Peak forces of ankle (flexors, extensors, and evertors), knee (flexors and extensors), and hip abductors distinguished DNG from DG, and both of those from CG. Both diabetic groups showed alterations in the force production of the ankle extensors with reductions in the forces of soleus (DG) and gastrocnemius medialis (DNG) seen in both diabetic groups, but only DNG showed an increase in the hamstrings (knee flexor) at push-off. A therapeutic approach focused on preserving the functionality of the knee muscles is a promising strategy, even if the ankle dorsiflexors and plantarflexors are included in the resistance training.This research received support of State of São Paulo Research Foundation (FAPESP) (2013/20813-6), with the PhD scholarship granted to A.A. Gomes and National Council for Scientific and Technological Development (CNPq) (MCT/CNPq 305606/2014-0)
Indoleamine 2, 3-dioxygenase (IDO) increases during renal fibrogenesis and its inhibition potentiates TGF-β 1-induced epithelial to mesenchymal transition
No full textAbstract\ud
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Background\ud
Indoleamine 2, 3-dioxygenase (IDO) is an immunomodulatory molecule that has been implicated in several biological processes. Although IDO has been linked with some renal diseases, its role in renal fibrosis is still unclear. Because IDO may be modulated by TGF-β1, a potent fibrogenic molecule, we hypothesized that IDO could be involved in renal fibrosis, especially acting in the TGF-β1-induced tubular epithelial-mesenchymal transition (EMT). We analyzed the IDO expression and activity in a model of renal fibrogenesis, and the effect of the IDO inhibitor 1-methyl-tryptophan (MT) on TGF-β1-induced EMT using tubular cell culture.\ud
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Methods\ud
Male Wistar rats where submited to 7 days of UUO. Non-obstructed kidneys (CL) and kidneys from SHAM rats were used as controls. Masson’s Tricrome and macrophages counting were used to chatacterize the tissue fibrosis. The EMT was analysed though immunohistochemistry and qRT-PCR. Immunohistochemestry in tissue has used to show IDO expression.\ud
MDCK cells were incubated with TGF- β1 to analyse IDO expression. Additionally, effects of TGF- β1 and the inhibition of IDO over the EMT process was acessed by immunoessays and scrath wound essay.\ud
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Results\ud
IDO was markedly expressed in cortical and medular tubules of the UUO kidneys. Similarly to the immunolocalizaton of TGF- β1, accompanied by loss of e-cadherin expression and an increase of mesenchymal markers. Results in vitro with MDCK cells, showed that IDO was increased after stimulus with TGF-β1, and treatment with MT potentiated its expression. MDCK stimulated with TGF-β1 had higher migratory activity (scratch-wound assay), which was exacerbated by MT treatment.\ud
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Conclusions\ud
IDO is constitutively expressed in tubular cells and increases during renal fibrogenesis. Although IDO is induced by TGF-β1 in tubular cells, its chemical inhibitor acts as a profibrotic agent
Responsiveness of the Early Childhood Oral Health Impact Scale (ECOHIS) is related to dental treatment complexity
No full textAbstract\ud
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Background\ud
The responsiveness of the Early Childhood Oral Health Impact Scale (ECOHIS) has varied greatly across studies; hence, we hypothesized that this discrepancy could be related to the complexity of dental treatment received. Thus, we aimed to evaluate the responsiveness of the ECOHIS to changes in oral health-related quality of life (OHRQoL) following dental treatments of varying complexity in preschool children.\ud
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Methods\ud
Preschool children aged 3 to 6 years were selected; their parents responded to the ECOHIS at baseline. The parents responded to the ECOHIS again and a global transition question 30 days after the children were treated. The type of treatment received by the children was categorized according to complexity, as follows: 1) non-operative treatment only, 2) restorative treatment, and 3) endodontic treatment and/or tooth extraction. Change scores and effect sizes (ES) were calculated for total scores, as well as considering the different treatment types and global transition question responses.\ud
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Results\ud
Of the 152 children who completed the study, the ECOHIS yielded large ES for total scores (0.89). The children showed increasing ES values associated with better perception of improvement, assessed by the global transition question. The magnitude of ES after treatment was related to treatment complexity (0.53, 0.92 and 1.43, for children who received non-operative treatment only, restorative treatment, and endodontic treatment and/or tooth extraction, respectively).\ud
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Conclusions\ud
Parents whose children required more complex dental treatment are more likely to perceive treatment-related changes to OHRQoL assessed with the ECOHIS.The study was funded by Conselho Nacional de Desenvolvimento Científico\ud
e Tecnológico – CNPq (Grants # 471817/2012–0 and 306,304/2015–5),\ud
Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP (Grant #\ud
2012/24243–7), and Coordenação de Aperfeiçoamento de Pessoal de Nível\ud
Superior (CAPES)
Clonality, outer-membrane proteins profile and efflux pump in KPC- producing Enterobacter sp. in Brazil
No full textAbstract\ud
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Background\ud
Carbapenems resistance in Enterobacter spp. has increased in the last decade, few studies, however, described the mechanisms of resistance in this bacterium. This study evaluated clonality and mechanisms of carbapenems resistance in clinical isolates of Enterobacter spp. identified in three hospitals in Brazil (Hospital A, B and C) over 7-year.\ud
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Methods\ud
Antibiotics sensitivity, pulsed-field gel electrophoresis (PFGE), PCR for carbapenemase and efflux pump genes were performed for all carbapenems-resistant isolates. Outer-membrane protein (OMP) was evaluated based on PFGE profile.\ud
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Results\ud
A total of 130 isolates of Enterobacter spp were analyzed, 44/105 (41, 9%) E. aerogenes and 8/25 (32,0%) E. cloacae were resistant to carbapenems. All isolates were susceptible to fosfomycin, polymyxin B and tigecycline. KPC was present in 88.6% of E. aerogenes and in all E. cloacae resistant to carbapenems. The carbapenems-resistant E. aerogenes identified in hospital A belonged to six clones, however, a predominant clone was identified in this hospital over the study period. There is a predominant clone in Hospital B and Hospital C as well. The mechanisms of resistance to carbapenems differ among subtypes. Most of the isolates co-harbored blaKPC, blaTEM and /or blaCTX associated with decreased or lost of 35–36KDa and or 39 KDa OMP. The efflux pump AcrAB-TolC gene was only identified in carbapenems-resistant E. cloacae.\ud
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Conclusions\ud
There was a predominant clone in each hospital suggesting that cross-transmission of carbapenems-resistant Enterobacter spp. was frequent. The isolates presented multiple mechanisms of resistance to carbapenems including OMP alteration.The study was financial support by CNPQ (Conselho Nacional de\ud
Desenvolvimento Científico e Tecnológico) and FAPESP (Fundação de\ud
Amparo à pesquisa do Estado de São Paulo, Brazil
Brazilian Society for Food and Nutrition position statement: nutrigenetic tests
No full textAbstract\ud
Position statement: The Brazilian Society for Food and Nutrition (SBAN) bases the following position statement on a critical analysis of the literature on nutritional genomics and nutrigenetic tests: (1) Nutrigenetic tests are predictive and not diagnostic, should not replace other evaluations required to treatment, and should only be used as an additional tool to nutritional prescription; (2) Nutritionists/registered dietitians and other health professionals must be able to interpret the nutrigenetic tests and properly guide their patients, as well as build their professional practice on general ethical principles and those established by regulatory authorities; (3) It is extremely important to highlight that the misinterpretation of nutrigenetic tests can cause psychological and health problems to the patient; (4) Currently, there is insufficient scientific evidence for the recommendation of dietary planning and nutritional supplementation based only on nutrigenetic tests. This position statement has been externally reviewed and approved by the board of SBAN and has not gone through the journal’s standard peer review process
A novel nonsense mutation in the tyrosinase gene is related to the albinism in a capuchin monkey (Sapajus apella)
No full textAbstract\ud
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Background\ud
Oculocutaneous Albinism (OCA) is an autosomal recessive inherited condition that affects the pigmentation of eyes, hair and skin. The OCA phenotype may be caused by mutations in the tyrosinase gene (TYR), which expresses the tyrosinase enzyme and has an important role in the synthesis of melanin pigment. The aim of this study was to identify the genetic mutation responsible for the albinism in a captive capuchin monkey, and to describe the TYR gene of normal phenotype individuals. In addition, we identified the subject’s species.\ud
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Results\ud
A homozygous nonsense mutation was identified in exon 1 of the TYR gene, with the substitution of a cytosine for a thymine nucleotide (C64T) at codon 22, leading to a premature stop codon (R22X) in the albino robust capuchin monkey. The albino and five non-albino robust capuchin monkeys were identified as Sapajus apella, based on phylogenetic analyses, pelage pattern and geographic provenance. One individual was identified as S. macrocephalus.\ud
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Conclusion\ud
We conclude that the point mutation C64T in the TYR gene is responsible for the OCA1 albino phenotype in the capuchin monkey, classified as Sapajus apella.This work was supported by the Foundation of Research Support in the State\ud
of São Paulo (FAPESP) with fellowships to EH (PhD 2010/51670-8; postdoc\ud
2014/25743-9), DMOB (postdoc 2011/17423-6) and research grants to DFV\ud
(Projetos Temáticos 2008/58731-2; 2015/26818-2 and Projeto Regular 2009/\ud
06026-6), and by CNPq with fellowships to DMOB (Projeto Universal MCTI/CNPq\ud
n.14/2014 - 456746/2014-5). DFV is a CNPq 1 A Productivity Fellow