576 research outputs found
Reflexão sobre a integração do sistema locomotor em uma proposta investigativa
Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014Os conteúdos da disciplina de Biologia são tradicionalmente abordados de maneira
fragmentada o que pode propiciar uma aprendizagem isolada dos conceitos. O objetivo desse trabalho
foi refletir sobre uma proposta de ensino investigativo que buscou integrar os conteúdos de sistema
ósseo, articular e muscular, bem como proporcionar aos alunos a aprendizagem que relacione os
conteúdos científicos, e sua relação com o cotidiano. Assim o presente trabalho é uma reflexão de uma
proposta investigativa, realizada em uma escola pública, desenvolvido por bolsistas do PIBID do
Subprojeto Biologia da Universidade Estadual do Oeste do Paraná. As atividades realizadas tiveram o
intuito de articular os diferentes sistemas. Verificou-se a partir da análise das atividades que os alunos
conseguiram relacionar melhor os conceitos, organizar suas ideias e entender o que é necessário para
que os sistemas trabalhem junto
Contribution of Autonomic Reflexes to the Hyperadrenergic State in Heart Failure
Heart failure (HF) is a complex syndrome representing the clinical endpoint of many cardiovascular diseases of different etiology. Given its prevalence, incidence and social impact, a better understanding of HF pathophysiology is paramount to implement more effective anti-HF therapies. Based on left ventricle (LV) performance, HF is currently classified as follows: (1) with reduced ejection fraction (HFrEF); (2) with mid-range EF (HFmrEF); and (3) with preserved EF (HFpEF). A central tenet of HFrEF pathophysiology is adrenergic hyperactivity, featuring increased sympathetic nerve discharge and a progressive loss of rhythmical sympathetic oscillations. The role of reflex mechanisms in sustaining adrenergic abnormalities during HFrEF is increasingly well appreciated and delineated. However, the same cannot be said for patients affected by HFpEF or HFmrEF, whom also present with autonomic dysfunction. Neural mechanisms of cardiovascular regulation act as "controller units," detecting and adjusting for changes in arterial blood pressure, blood volume, and arterial concentrations of oxygen, carbon dioxide and pH, as well as for humoral factors eventually released after myocardial (or other tissue) ischemia. They do so on a beat-to-beat basis. The central dynamic integration of all these afferent signals ensures homeostasis, at rest and during states of physiological or pathophysiological stress. Thus, the net result of information gathered by each controller unit is transmitted by the autonomic branch using two different codes: intensity and rhythm of sympathetic discharges. The main scope of the present article is to (i) review the key neural mechanisms involved in cardiovascular regulation; (ii) discuss how their dysfunction accounts for the hyperadrenergic state present in certain forms of HF; and (iii) summarize how sympathetic efferent traffic reveal central integration among autonomic mechanisms under physiological and pathological conditions, with a special emphasis on pathophysiological characteristics of HF
Short-term complexity of cardiac autonomic control during sleep: REM as a potential risk factor for cardiovascular system in aging.
peer reviewedINTRODUCTION: Sleep is a complex phenomenon characterized by important modifications throughout life and by changes of autonomic cardiovascular control. Aging is associated with a reduction of the overall heart rate variability (HRV) and a decrease of complexity of autonomic cardiac regulation. The aim of our study was to evaluate the HRV complexity using two entropy-derived measures, Shannon Entropy (SE) and Corrected Conditional Entropy (CCE), during sleep in young and older subjects. METHODS: A polysomnographic study was performed in 12 healthy young (21.1+/-0.8 years) and 12 healthy older subjects (64.9+/-1.9 years). After the sleep scoring, heart period time series were divided into wake (W), Stage 1-2 (S1-2), Stage 3-4 (S3-4) and REM. Two complexity indexes were assessed: SE(3) measuring the complexity of a distribution of 3-beat patterns (SE(3) is higher when all the patterns are identically distributed and it is lower when some patterns are more likely) and CCE(min) measuring the minimum amount of information that cannot be derived from the knowledge of previous values. RESULTS: Across the different sleep stages, young subjects had similar RR interval, total variance, SE(3) and CCE(min). In the older group, SE(3) and CCE(min) were reduced during REM sleep compared to S1-2, S3-4 and W. Compared to young subjects, during W and sleep the older subjects showed a lower RR interval and reduced total variance as well as a significant reduction of SE(3) and CCE(min). This decrease of entropy measures was more evident during REM sleep. CONCLUSION: Our study indicates that aging is characterized by a reduction of entropy indices of cardiovascular variability during wake/sleep cycle, more evident during REM sleep. We conclude that during aging REM sleep is associated with a simplification of cardiac control mechanisms that could lead to an impaired ability of the cardiovascular system to react to cardiovascular adverse events
A iniciação a docência a partir da abordagem CTS
Anais do II Seminário Seminário Estadual PIBID do Paraná: tecendo saberes / organizado por Dulcyene Maria Ribeiro e Catarina Costa Fernandes — Foz do Iguaçu: Unioeste; Unila, 2014No contexto educacional, percebe-se o distanciamento entre a Universidade e a Escola, ou seja, o
distanciamento entre a teoria acadêmica e a prática escolar, que se torna um obstáculo na formação de
futuros professores. Á vista disso, o Programa Institucional de Bolsas de Iniciação a Docência (Pibid)
possibilita um contato com o espaço escolar, proporcionando maior convívio do acadêmico com esse espaço.
Dessa forma, o presente trabalho tem como objetivo relatar as experiências de alguns bolsistas de um
subprojeto Pibid ao utilizar a abordagem Ciência-Tecnologia-Sociedade (CTS) em sua prática pedagógica. A
partir dos relatos dessas bolsistas percebeu-se que a abordagem CTS possibilitou uma aula mais atrativa, o
que permite ao aluno se posicionar perante a sociedade e compreender sua relação com a ciência e
tecnologia, ao mesmo tempo em que se torna um fator importante na prática de ensino de futuros
professore
Genotypic variability and antifungal susceptibility of Candida spp. isolated from hospital surfaces and hands of healthcare professionals
Objectives Candida spp. are responsible for 9095% of hematogenous fungal infections. In Brazil and Latin America, C. albicans is the most common specie, followed by C. parapsilosis and C. tropicalis. Infections caused by Candida spp. may have their origin in exogenous sources, transmitted to patients via contaminated infusions, biomedical devices or even by the hands of the hospital staff members. Molecular biology techniques such as Randomly Amplified Polymorphic DNA (RAPD) can show that the strains found in anatomical sites or abi- otic surfaces have the same pattern genome.Moreover, in the last decades it has been observed increasing the number of yeasts isolated from hospital environment resistant to antifungals. Thus, the aim of this study was to determine the susceptibility to antifungals and intraspecies similarity among isolates of different hospital surfaces and hands of healthcare professionals.
Methods The study was conducted with 25 isolates of Candida spp.: 5 strains of C. albicans and 5 strains of C. parapsilosis isolated from hospital surfaces. 5 strains of C. albicans, 5 strains of C. parapsilosis and 5 strains of C. tropicalis isolated from hands of healthcare professionals. Professionals and surfaces belonged to intensive care units. The minimal inhibitory concentration (MIC) was determined to voriconazole (VOR), fluconazole (FLZ), amphotericin B (AMB) and micafungin (MFG) according to M27-A3 of the Clinical and Labora- tory Standards Institute (CLSI). To determine the intra-species similarity, 3 primers were used: P4 (50 -AAGAGCCCGT-30 ), OPA-18 (50AGCTGACCGT30) and OPE-18 (50GGACTGCAGA 30). RAPD pro- files were analyzed using BioNumerics software version 4.6. The study was approved by the Ethics in research involving human subjects, CAAE 0448.0.093.000-11 protocol.
Results In relation to susceptibility testing (Table 1), it is important to highlight that C. parapsilosis showed 80% of MFG resistance. C. albicans and C. tropicalis showed reduced susceptibility to VOR, and resistence of the AMB was observed for C. albicans (20%). All amplifi- cations revealed distinct polymorphic bands. Genetic distances between each of the isolates were calculated and cluster analysis was used to generate a dendrogram showing relationships between them. The analysis of all primers showed similarity greater than 80% between strains of hands and hospital surfaces for intraspecies. Conclusion Our work shows that, healthy people and hospital surfaces may be colonized by different species yeast. Furthermore, the strains studied had relative resistance to antifungal drugs most frequently used in clinical practice. Finally, there was a high similarity between samples from hands (hospital staff members) and surfaces, providing an infection risk to susceptible individuals. Healthy people working in hospitals can carry yeasts on their hands with the same potential virulence, and which therefore offer the same risk of infection. This information should be considered when preventive measures are established. Attention to the colonization of hands and surfaces should not be restricted to high-risk units such as NICUs, but should also include other sections of hospitals
Evaluation of propolis and its subproduct as an inhibitor of growth and biofilm formation in vaginal yeast from pregnant women
Objectives The treatment of vulvovaginal candidiasis (VVC) is still unsatisfactory, especially in pregnant women, being promising to the utilization of alternative therapies. Propolis extract solution (PES) has demonstrated antifungal efficacy and low toxicity. In addition, the subproduct of propolis extract solution (SPES) is produced during the process of preparing PES and is usually discarded, but can still sub- mit substances responsible for biological effects, such as the polyphenols, responsible for the therapeutic activity of propolis. SPES have not been investigated or used as an antimicrobial agent. Thus, the objective of the present study was to investigate the effect of PES and SPES on Candida spp. isolated from the vaginal material of pregnant women.
Methods Vaginal samples from 291 pregnant women were collected and cultivated for yeasts, which were identified by the classical method and performing susceptibility tests against PES, SPES and conventional antifungal agents. The anti-biofilm effect and cytotoxicity tests of the PES and SPES were evaluated.
Results In 38.48% (112/291) of culture was positive for Candida species. There were patients with two different species, being a total of 115 yeasts (82.61% C. albicans; 6.08% C. glabrata; 5.22% C. tropi- calis; 5.22% C. parapsilosis and 0.87% C. krusei). PES and SPES were effective, even against isolates resistant to conventional antifungal (Table 1) and reduced about 25% C. tropicalis biofilm, besides presenting its low toxicity in the concentrations of fungicides. Conclusion Thus, in addition to the PES, SPES can also be a promising alternative treatment, especially in this population
Assessment of in vitro biofilm formation and antifungal susceptibility of Candida albicans isolates from vulvovaginal candidiasis
Objectives Vulvovaginal candidiasis (VVC) is an inflammation of the genital mucosa, which mainly affects the vulva and vagina. Candida spp. are considered commensal fungus, however, when there is imbalance in the microbiota or the host immune system is compromised, these can become pathogenic. C. albicans is responsible for most cases of VVC and is able of expressing mechanisms which allow the colonization or infection in the host. These factors related yeasts, including the growth of strains resistant to antifungal agents and virulence attributes (such as biofilm formation) are important in the development of VVC. In this sense, the objective of this study was to evaluate the in vitro biofilm formation and susceptibility to antifungal of C. albicans isolates from patients with vulvovaginal candidiasis. Methods For the study were analyzed 30 clinical isolates of Candida albicans. The clinical isolates were separated in groups of 10 samples of the according to symptoms presented by the patients: asymptomatic (AS), vulvovaginal candidiasis (VVC) and recurrent vulvo- vaginal candidiasis (RVVC). For all isolates were analyzed biofilm formation and minimal inhibitory concentration (MIC) for fluconazole and nystatin. The MIC was performed according to M27-A3 protocol of the Clinical Laboratory Standards Institute. Biofilm forming ability was assessed through quantification of total biomass by crystal violet (CV) staining, performed on 96-well microplates containing a cellular suspension of 1 9 107 cells ml1 and incubated for 24 h at 37°C.
Results Antifungal susceptibility testing is showed in table 1. The isolates were tested to the two antifungals. The MIC raging from 0.125 to 2 lg ml1 for fluconazole and 1 to 4 lg ml1 to nystatin. The figure 1 show the quantification of the total biomass. It was evident that all the C. albicans isolates were able to form biofilm, although differences occurred depending on the isolated and consequently the group. Importantly it was noted that, in general, VVC and RVVC groups had similar capacity biofilm formation. On the other hand, these groups had less total biomass (average Abs = 1,091 ` 0.88) compared with AS group (average Abs = 1,521 ` 1.32).
Conclusion Although all the samples analyzed are sensitive to anti- fungals tested research of resistant strains is relevant, since recurrences are related to cases of VVC. Nystatin and fluconazole were effective in small concentrations for the isolates analysed. All samples were able to form biofilm and the average of the group of asymptomatic patients greater than the others. Thus, the capacity to form- ing biofilm is an important virulence factor in the persistence of microorganisms in infectious processes and represent an increase in resistance to antifungal and host defense
Virulence potential of Candida albicans isolated from oral cavity of patients with chronic renal failure on hemodialysis
Objective In patients with chronic renal failure (PCRF), the frequency of colonization of the oral cavity by yeasts of genus Candida spp. is high compared with healthy individuals. These yeasts have virulence factors that may contribute to the persistence of colonization and the development of these infections. The aim of this study was evaluate aspects of virulence from Candida albicans isolated from oral cavity of PCRF on dialysis.
Methods This study was initially conducted with 49 clinical samples of C. albicans. The virulence factors assayed were produce of biofilm, germ tube, determination of adherence in oral epithelial cells and evaluation of resistance to the antimicrobial action of neutrophils and mononuclear cells.
Results All isolates were highly efficient in forming biofilms on poly- styrene microplates, where 94% of the samples formed 4 + biofilm. Used as a screening test, of which three isolates were selected with different degrees of ability to form biofilm to assess other indicators of virulence. Overall, the isolates exhibited different characteristics regarding the virulence factors analyzed. It was also observed that the hypophosphorous acid (HOCl), production, one of leading inflammatory mediators with fungicidal action, also varied especially when the neutrophils, and not mononuclear cells, were stimulated with different samples. (Figure 1).
Conclusion Therefore, our results indicate that C. albicans, is not only the most common species in the oral cavity of CRFP on dialysis, but also it presents the main virulence attributes, which reinforces the importance of monitoring of these patients towards the prevention of fungal infections
Propolis: a potential natural product to fight Candida species infections
Aim: To evaluate the effect of propolis against Candida species planktonic cells and its counterpart's biofilms. Materials & methods: The MIC values, time-kill curves and filamentation form inhibition were determined in Candida planktonic cells. The effect of propolis on Candida biofilms was assessed through quantification of CFUs. Results: MIC values, ranging from 220 to 880 µg/ml, demonstrated higher efficiency on C. albicans and C. parapsilosis than on C. tropicalis cells. In addition, propolis was able to prevent Candida species biofilm's formation and eradicate their mature biofilms, coupled with a significant reduction on C. tropicalis and C. albicans filamentation. Conclusion: Propolis is an inhibitor of Candida virulence factors and represents an innovative alternative to fight candidiasis.The authors thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (Cnpq) and Fundação Araucária for the financial support received. Flávia Tobaldini-Valerio acknowledges the financial support of CAPES – Proc. 9469/14-1. The authors also thank FCT for the Strategic Project of the UID/BIO/04469/2013 unit, FCT and European Union funds (FEDER/COMPETE) for the project RECI/BBBEBI/0179/2012 (FCOMP-01-0124-FEDER-027462). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed
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