1,274 research outputs found
Influence of normal mammary epithelium on breast cancer progression: the protective role of early pregnancy
AIMS AND BACKGROUND: The microenvironment has a well recognized role in breast cancer progression. Despite different theories, the mechanism of early pregnancy protection in mammary carcinogenesis is unknown. Since pregnancy is responsible for mammary gland differentiation, we tested the hypothesis that differentiated mammary epithelial cells may inhibit breast cancer progression. In other words, the protective role of early pregnancy could be due to the inhibitory influences of the more differentiated mammary tissue.
METHODS: In order to test our hypothesis, we used 30 female Balb/c nude mice and MCF-7 cells of breast adenocarcinoma. The female mice were divided into two test groups, group I (GI) and group II (GII), and a control group. In GII, the animals were submitted to epithelial removal in the left fourth inguinal mammary gland at 3 weeks of age. Both groups were given continuous hormonal treatment to simulate the pregnancy development of the mammary gland. Two million MCF-7 cells were then injected into the fourth inguinal mammary gland (GI) or in the respective cleared mammary fat pad (GII). Five weeks later the mice were sacrificed and their tumors removed. Tumor development rates and tumor volumes were determined and proliferation and apoptosis were evaluated by immunohistochemistry.
RESULTS: Tumors of GII mice had a larger mean volume than those of GI mice (P = 0.001, Mann-Whitney U-test) and an apparent increase in proliferation, demonstrated by a higher staining intensity for proliferating cell nuclear antigen (PCNA). As tumors presented caspase 8 staining, there may be apoptotic activation involved in cell death, mainly through an extrinsic pathway.
CONCLUSIONS: These results suggest that a differentiated intact mammary gland may have an inhibitory influence on mammary tumor growth in mice
Management of Streptococcus mutans-Candida spp. Oral biofilms’ infections: Paving the way for effective clinical interventions
Oral diseases are considered the most common noncommunicable diseases and are related to serious local and systemic disorders. Oral pathogens can grow and spread in the oral mucosae and frequently in biomaterials (e.g., dentures or prostheses) under polymicrobial biofilms, leading to several disorders such as dental caries and periodontal disease. Biofilms harbor a complex array of interacting microbes, increasingly unapproachable to antimicrobials and with dynamic processes key to disease pathogenicity, which partially explain the gradual loss of response towards conventional therapeutic regimens. New drugs (synthesized and natural) and other therapies that have revealed promising results for the treatment or control of these mixed biofilms are presented and discussed here. A structured search of bibliographic databases was applied to include recent research. There are several promising new approaches in the treatment of Candida spp.–Streptococcus mutans oral mixed biofilms that could be clinically applied in the near future. These findings confirm the importance of developing effective therapies for oral Candida–bacterial infections.C.F.R. would like to acknowledge the UID/EQU/00511/2019 Project—Laboratory of Process Engineering, Environment, Biotechnology and Energy (LEPABE), financed by national funds through FCT/MCTES (PIDDAC). N.M. would like to thank the Portuguese Foundation for Science and Technology (FCT-Portugal) for the Strategic project ref. UID/BIM/04293/2013 and “NORTE2020—Northern Regional Operational Program” (NORTE-01-0145-FEDER-000012)
Faster and slower posttraining recovery in futsal: Multifactorial classification of recovery profiles
© 2019 Human Kinetics, Inc. Purpose: To investigate the existence of faster vs slower recovery profiles in futsal and factors distinguishing them. Methods: 22 male futsal players were evaluated in countermovement jump, 10-m sprint, creatine kinase, total quality of recovery (TQR), and Brunel Mood Scale (fatigue and vigor) before and immediately and 3, 24, and 48 h posttraining. Hierarchical cluster analysis allocated players to different recovery profiles using the area under the curve (AUC) of the percentage differences from baseline. One-way ANOVA compared the time course of each variable and players’ characteristics between clusters. Results: Three clusters were identified and labeled faster recovery (FR), slower physiological recovery (SLphy), and slower perceptual recovery (SLperc). FR presented better AUC in 10-m sprint than SLphy (P = .001) and SLperc (P = .008), as well as better TQR SLphy (P = .018) and SLperc (P = .026). SLperc showed better AUC in countermovement jump than SLphy (P = .014) but presented worse fatigue AUC than SLphy (P = .014) and FR (P = .008). AUC of creatine kinase was worse in SLphy than in FR (P = .001) and SLperc (P < .001). The SLphy players were younger than SLperc players (P = .027), whereas FR were slower 10-m sprinters than SLphy players (P = .003) and SLperc (P = .013) and tended to have higher maximal oxygen consumption than SLphy (effect size = 1.13). Conclusion: Different posttraining recovery profiles exist in futsal players, possibly influenced by their physical abilities and age/experience
Phytochemicals in prostate cancer: From bioactive molecules to upcoming therapeutic agents
Prostate cancer is a heterogeneous disease, the second deadliest malignancy in men and the most commonly diagnosed cancer among men. Traditional plants have been applied to handle various diseases and to develop new drugs. Medicinal plants are potential sources of natural bioactive compounds that include alkaloids, phenolic compounds, terpenes, and steroids. Many of these naturally-occurring bioactive constituents possess promising chemopreventive properties. In this sense, the aim of the present review is to provide a detailed overview of the role of plant-derived phytochemicals in prostate cancers, including the contribution of plant extracts and its corresponding isolated compounds.This work was supported by CONICYT PIA/APOYO CCTE AFB170007. N. Martins would like to thank the Portuguese Foundation for Science and Technology (FCT–Portugal) for the Strategic project ref. UID/BIM/04293/2013 and “NORTE2020 - Programa Operacional Regional do Norte” (NORTE-01-0145-FEDER-000012) and C. F. Rodrigues for the UID/EQU/00511/2019 Project—Laboratory of Process Engineering, Environment, Biotechnology, and Energy—LEPABE financed by national funds through FCT/MCTES (PIDDAC)
Techniques for Arbuscular Mycorrhiza Inoculum Reduction
It is well established that arbuscular mycorrhizal (AM) fungi can play a significant role in sustainable crop production and environmental conservation. With the increasing awareness of the ecological significance of mycorrhizas and their diversity, research needs to be directed away from simple records of their occurrence or casual speculation of their function (Smith and Read 1997). Rather, the need is for empirical studies and investigations of the quantitative aspects of the distribution of different types and their contribution to the function of ecosystems.
There is no such thing as a fungal effect or a plant effect, but there is an interaction between both symbionts. This results from the AM fungi and plant community size and structure, soil and climatic conditions, and the interplay between all these factors (Kahiluoto et al. 2000). Consequently, it is readily understood that it is the problems associated with methodology that limit our understanding of the functioning and effects of AM fungi within field communities.
Given the ubiquous presence of AM fungi, a major constraint to the evaluation of the activity of AM colonisation has been the need to account for the indigenous soil native inoculum. This has to be controlled (i.e. reduced or eliminated) if we are to obtain a true control treatment for analysis of arbuscular mycorrhizas in natural substrates. There are various procedures possible for achieving such an objective, and the purpose of this chapter is to provide details of a number of techniques and present some evaluation of their advantages and disadvantages.
Although there have been a large number of experiments to investigated the effectiveness of different sterilization procedures for reducing pathogenic soil fungi, little information is available on their impact on beneficial organisms such as AM fungi. Furthermore, some of the techniques have been shown to affect physical and chemical soil characteristics as well as eliminate soil microorganisms that can interfere with the development of mycorrhizas, and this creates difficulties in the interpretation of results simply in terms of possible mycorrhizal activity.
An important subject is the differentiation of methods that involve sterilization from those focussed on indigenous inoculum reduction. Soil sterilization aims to destroy or eliminate microbial cells while maintaining the existing chemical and physical characteristics of the soil (Wolf and Skipper 1994). Consequently, it is often used for experiments focussed on specific AM fungi, or to establish a negative control in some other types of study. In contrast, the purpose of inoculum reduction techniques is to create a perturbation that will interfere with mycorrhizal formation, although not necessarily eliminating any component group within the inoculum. Such an approach allows the establishment of different degrees of mycorrhizal formation between treatments and the study of relative effects.
Frequently the basic techniques used to achieve complete sterilization or just an inoculum reduction may be similar but the desired outcome is accomplished by adjustments of the dosage or intensity of the treatment. The ultimate choice of methodology for establishing an adequate non-mycorrhizal control depends on the design of the particular experiments, the facilities available and the amount of soil requiring treatment
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