1,721,033 research outputs found
In vitro exploration of probiotic bacteria interactions with candida using culture techniques to model dysbiotic conditions in colonized tissues
Full text linkCandida albicans overgrowth at various mucosal sites is an ongoing and complex clinical concern involving interactions with indigenous microbiota and therapeutic or preventive measures superimposed on the pathogen-microbiome interaction. In this paper we describe the use of quantitative flow cytometry (specific to the cytometer’s sample introduction mechanism) to explore the in vitro interaction between Candida albicans, probiotic lactobacilli and a topical vaginal therapeutic. Our central hypothesis was cytometric measurements of co-cultures of yeast and bacteria could provide a useful method for exploring the dynamics of different microbial species in culture, with and without inhibitors. Two commercial products were used as exemplars for this research, a vaginal antimicrobial gel and two species of probiotic lactobacillus intended or oral administration with crystalline bovine lactoferrin to augment the vaginal gel. The cytometer forward channel height parameter distinguished yeast from bacteria in co-culture experiments in the presence of a vaginal therapeutic gel or components of its formulation including EDTA, glycogen, polydextrose as well as the host defense factor, lactoferrin. Flow cytometry showed lactobacilli influenced yeast counts in co-culture, with the technique lending itself to wide-ranging test conditions including organisms, media composition and screening of various antimicrobials. Key findings: The proprietary vaginal gel augmented the effect of lactobacilli, as did EDTA and lactoferrin. Prebiotic compounds also enhanced Candida inhibition by lactobacilli. Propidium iodide (Fluorescence channel 3) discriminated between necrotic and non-necrotic yeast and bacteria in co-cultures under various culture conditions. This research demonstrates the value of flow cytometry to evaluate the population dynamics of yeast and bacteria in co-culture using a proprietary product and its components. We discuss both the limitations of the current study and describe how methods employed here would be transferrable to the investigation of organisms present in defined cultures or at body sites colonized by fungal species and the effects of therapeutics or probiotics on Candida
The role of microbiota in the management of genitourinary syndrome of menopause
No full textIt is estimated that the 25-50% of women who are reaching menopause every year report symptoms related to the genitourinary syndrome of menopause (GSM). The symptoms are not due simply to lack of estrogen. One possible contributing cause of symptoms is the vaginal microbiota. The vaginal microbiota is a dynamic entity and plays a critical role in the pathogenic interplay of postmenopausal changes. Treatment of this syndrome depends on the severity and type of the symptoms and on the preferences and expectations of women. As there are many treatment options, therapy should be individualized. While new evidence on the role of Lactobacilli in premenopause is emerging, the role of Lactobacilli is still unclear in GSM and the impact of microbiota on vaginal health remains conflictual. However, some reports show promising data on the effect of probiotic therapy in menopause. In the literature there are few studies and small population samples on the role of an exclusive therapy with Lactobacilli and further data will be mandatory. Studies involving large numbers of patients and different intervention periods will be necessary to obtain evidence of the preventive and curative role of vaginal probiotics
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Induced Dryness Stress on Human Vaginal Epithelium: The Efficacy of a New Vaginal Gel
Full text linkAn experimental model of dryness on vaginal mucosa is proposed to assess the efficacy of a new vaginal gel (Respecta® Hydragel Ref 17031). The dryness model was induced on reconstituted human vaginal epithelium (HVE) by incubating the tissues in modified environmental conditions (R.H. 2). Their efficacy in counteracting vaginal dryness was assessed and compared to tissues treated with saline solution and cultured in standard culture conditions (negative control) and to untreated tissues incubated in dryness conditions for 48 h and then recovered after 24 h in standard culture conditions (positive control). The products’ efficacy was quantified by measuring the following parameters: (1) water flux and direct moisturization by AQP3 immunohistochemical staining, and (2) maintenance of moisturization and elasticity of the mucosa by hyaluronic acid (CD44) immunofluorescence staining. Respecta® Hydragel demonstrated efficacy in regulating the water flux by inducing AQP3 expression thus determining a positive water balance within the vaginal epithelium. It induced a remodelling of the epithelium morphology with restored trophism compared to the dry HVE control. Furthermore, it demonstrated a significant increase of the expression of CD44, related to hyaluronic acid (HA) distribution in the extracellular matrix. HA has the ability to act on the cellular matrix composition and its renewal compared to the dry HVE control. Through these mechanisms it induces a deep hydration and elasticity of the vaginal mucosa
The Candida albicans Pra1 zincophore promotes neutrophils recruitment and inflammation during vulvovaginal candidiasis
No full textThe symptoms of infectious diseases are frequently caused by an overzealous host immune response against the invading microorganism, rather than by the microorganism itself. This is the case for one of the most common mucosal infection, vulvovaginal candidiasis (VVC), where the yeast Candida albicans triggers a non‐protective influx of host immune cells, resulting in aggressive local inflammation and symptomatic disease.
The aim of our study was to investigate the role of the zincophore Pra1 in VVC immunopathology. Pra1 is a secreted C. albicans zinc binding protein released during zinc limitation and used by the fungus to forage for this essential micronutrient from the environment.
In vitro tissue culture systems, a murine model of experimental vaginal candidiasis and vaginal samples from VVC patients were used to evaluate the role of Pra1 in immunopathology during VVC.
Our results show that Pra1 induced neutrophil migration, is expressed at both, neutral and acidic pH by C. albicans during infection of vaginal epithelial cells and the expression was repressed by the addition of zinc. Robust PRA1 expression was also found in clinical vaginal samples and a strong correlation between PRA1 expression and the neutrophilactivating cytokine IL8 has been demonstrated. In an experimental murine model of VVC, deletion of C. albicans PRA1 abrogated inflammation without affecting fungal burden.
These data demonstrate that the zincophore Pra1 is expressed during the VVC and can act as a potent neutrophil chemoattractant molecule, driving inflammation
Bacterial Vaginosis and preterm delivery - An open question
No full textOBJECTIVE: To evaluate the prevalence of bacterial vaginosis in a population of Italian pregnant women and to study its association with adverse pregnancy outcomes,. particularly preterm delivery.STUDY DESIGN: After giving informed consent, 598 women were consecutively enrolled at their first prenatal visit (13-18 weeks of gestation). The presence of bacterial vaginosis was assessed by Gram's method at 13-18 weeks of gestation (early bacterial vaginosis) and at 28-32 weeks of gestation (late bacterial vaginosis). Univariate and multiple logistic regression models of analysis were used to assess the statistical significance of the data.RESULTS: Preterm delivery occurred in 14.7% of pregnant women positive for bacterial vaginosis at their first prenatal visit and in 6.9% of healthy women (OR 1.6, CI 1.07-2.51). In patients with bacterial vaginosis, preterm delivery occurred more often in the 36th week of gestation (78.6%).CONCLUSION. The presence of bacterial vaginosis at an early gestational age is associated,with preterm delivery, although in the study population the condition did not seem to be related to great prematurity
Soluble TRAIL is elevated in recurrent miscarriage and inhibits the in vitro adhesion and migration of HTR8 trophoblastic cells
No full textSTUDY QUESTION. What is the potential physiopathological role of tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) in recurrent miscarriage (RM), characterized by at least three consecutive pregnancy losses.
SUMMARY ANSWER. The levels of serum TRAIL immediately after miscarriage in RM patients are significantly elevated with respect to that in first-trimester normal pregnant women, and recombinant TRAIL inhibits the adhesion and migration of HTR8 trophoblastic cells in vitro.
WHAT IS KNOWN ALREADY. Both TRAIL and its trans-membrane receptors (TRAIL-R1, TRAIL-R2, TRAIL-R3 and TRAIL-R4) have been documented in the placenta, but their physiopathological role is incompletely understood.
STUDY DESIGN, SIZE, DURATION. The study populations consisted of RM patients (n = 80) and first-trimester normal pregnant women (n = 80). Blood samples were obtained within 24 h after abortion (RM) or at gestational 12-week (normal pregnant women). As additional controls, third-trimester normal pregnant women (n = 28) were examined before (within 72 h) and after (within 24 h) partum.
PARTICIPANTS/MATERIALS, SETTING, METHODS. The concentrations of TRAIL were analysed in serum samples by ELISA. In parallel, the effect of soluble recombinant TRAIL (0.1-1000 ng/ml) was analysed on the survival of primary extravillus trophoblasts (EVTs) and on the survival, proliferation, adhesion and migration of trophoblastic HTR8 cells.
MAIN RESULTS AND THE ROLE OF CHANCE. The circulating levels of TRAIL in RM women (median: 52.5 pg/ml; mean and SD: 55.5 ± 24.4 pg/ml) were significantly higher with respect to first-trimester normal pregnant women (median: 44.9 pg/ml; mean and SD: 47 ± 15.1 pg/ml) and third-trimester normal pregnant women, as assessed before (median: 45.1 pg/ml; mean and SD: 46 ± 12.4 pg/ml) and after partum (median: 35.4 pg/ml; mean and SD: 38 + 17.5 pg/ml). Both primary EVT and HTR8 cells expressed detectable levels of TRAIL death receptors, but exposure to soluble recombinant TRAIL did not induce cell death of trophoblastic cells. On the other hand, TRAIL dose-dependently inhibited the adhesion of HTR8 cells to decidual endothelial cells (DEC) as well as the migration of HTR8 in transwell assays using either fibronectin or DEC.
LIMITATIONS, REASONS FOR CAUTIONAl. though this study suggests that TRAIL might have a pathogenic role in RM by inhibiting both the adhesion and migration capabilities of first trimester trophoblastic cells, there is a possibility that the elevated serum levels of TRAIL in RM are not cause but rather the result of RM.
WIDER IMPLICATIONS OF THE FINDINGS. Our current findings together with data of other authors suggest that circulating TRAIL should be further analysed as a potential important biomarker in different physiopathological settings
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