329 research outputs found
GRP78 expression in canine mammary tumors: association with malignancy
78-kDa glucose-regulated protein (GRP78) is over-expressed in human breast carcinomas. GRP78 expression was studied in 40 spontaneous canine mammary tumors and evaluated in relation to tumor histological type, mode of growth, grade, lymph node metastases and distant metastases. All tumors exhibited GRP78 immunostaining. In the normal canine mammary gland, GRP78 was also expressed although not in all cases. In carcinomas GRP78 was detected in the cytoplasm in more than 50% of tumor cells in the vast majority of cases (87.5%). There was a significant association between the absence of squamous differentiation (PÂ =Â 0.02) and GRP78 over-expression, but no association with other clinico-pathological features. GRP78 was often co-expressed with galectin-3 in canine mammary tumors (CMT).
Monitorização da adulteração de suplementos alimentares à base de plantas comercializados em Portugal com inibidores de fosfodiesterase tipo 5 (PDE-5)
Na ultima década, assistiu-se a um consumo crescente de suplementos alimentares pela população
mundial, especialmente, no que diz respeito ao consumo de suplementos alimentares a base de
plantas 1. Estes são utilizados com diversas finalidades, tais como equilibrar a dieta, compensar uma
falta nutricional, manter a saúde, prevenir doenças crónicas, melhorar a aparência e o bem-estar
incluindo a condição mental, sexual e desportiva, entre outras 1. São produtos frequentemente
rotulados como "naturais" o que transmite uma falsa sensação de segurança aos consumidores.
Contudo, recentemente foi referida a ocorrência de adulterações nestes produtos, o que compromete
a sua segurança. Entre os casos de fraude detetados destaca-se a adição de substâncias ilegais.
Atualmente, os suplementos para melhorar o desempenho sexual estão entre os suplementos
alimentares mais populares entre os consumidores. A disfunção eréctil e uma doença que afeta 150
milhões de homens mundialmente sendo o tratamento recomendado a administração de fármacos
inibidores da enzima fosfodiesterase tipo 5 (PDE-5) 2. Os inibidores PDE-5 legalmente
comercializados a nÃvel europeu são: citrato de sildenafil, tadalafil, hidrocloreto de vardenafil e
avanafil 3. Estas são substâncias com efeitos secundários graves quando administrado
concomitantemente com medicamentos como nitratos ou a-bloqueadores 4.
0 objetivo deste trabalho foi, por isso, a monitorização da presença de adulterantes do tipo inibidores
PDE-5 em suplementos alimentares a base de plantas vendidos com o objetivo de melhorar a
performance sexual. Foram analisados doze suplementos alimentares, adquiridos no mercado
português. Estes suplementos foram pesquisados quanto a presença de sildenafil, acetildenafil,
tiosildenafil, tadalafil, vardenafil e yombina, atraves de metodo de crornatografia lÃquida de elevada
performance acoplada a detetor de dÃodos e detetor de fluorescência em série (HPLC-DAD-FL). Dos
doze suplementos analisados, seis revelaram a presença de um ou mais dos inibidores PDE-5
referidos. Adicionalmente, dois outros suplementos revelaram a presença de dois compostos, cujo
espectro UV-Vis leva a suspeição de uma possÃvel adulteração com compostos análogos à s substâncias pesquisadas.info:eu-repo/semantics/publishedVersio
Virulence factor of Candida tropicalis isolated from hospitalized patients
Candida tropicalis has been reported to be one of the Candida species which is most likely to cause bloodstream and urinary tract infections in hospitals. Several virulence factors seem to be responsible for C. tropicalis infections, which present high potential for dissemination and mortality. The aim of this study was to investigate the correlation between different virulence factors (enzymes secretion, adhesion and biofilm formation) and antifungal susceptibility of several C. tropicalis clinical isolates. This study was conducted with 8 isolates of C. tropicalis obtained from urine cultures (4), from blood culture (1) and from central venous catheter (1), from patients admitted to intensive care units at the University Hospital in Maringá, Paraná, Brazil. C. tropicalis ATCC 750 was also used, as a control. Virulence factors evaluated included: adhesion to epithelial cells and silicone, biofilm formation and enzyme production (hemolysins, proteinases, and phospholipases). Susceptibility to fluconazole, itraconazole, voriconazole, and amphotericin B was also determined, by E-test. Regarding adhesion, it can be highlighted that C. tropicalis adhered significantly more (p<0.05) to epithelial cells than to silicone. Morevoer, it was verified that all C. tropicalis were prone to form biofilms on silicone. Regarding C. tropicalis enzymatic activity, it was possible to verify that all isolates were able to express total hemolytic activity on sheep-blood agar medium supplemented with glucose. However, proteinase was only produced by two urine isolates and by the isolates from catheter and blood and only one C. tropicalis (from catheter) was phospholipase positive. All isolates were susceptible to voriconazole, fluconazole and amphotericin B. The largest percentage of susceptibility-dose dependence was observed for itraconazole in 4 strains (57.1%). Furthermore one clinical isolate (14.3%) from urine was found to be resistant to the same compound (MIC = 1 µg/ml). Thus, it is possible to conclude that there was no direct correlation between the virulence factors assayed (secretion of enzymes, adhesion to epithelial cells and silicone and biofilm formation). Concerning C. tropicalis susceptibility, it was not possible to establish any relation with Candida virulence factors as well. However, it is important to highlight that all isolates presented one or more virulence factors
Candida albicans enhanced phospholipase production after exposition to a static non-uniform magnetic field
INTRODUCTION: Microbial virulence factors are responsible for tissue damage in hosts. Candida
albicans is an opportunistic pathogen that constitutes an increasing risk of infection, especially for
immunosuppressed or immunocompromised patients.
OBJECTIVE: The objective of this study was to determine the effect of a static non-uniform magnetic
field on the phenotype expression of different strains of Candida albicans.
METHODS: The strains of Candida albicans were grown on phospholipase-agar, according to Shimizu et
al. (1996) and incubated at 37 ºC inside a magnetic field (except the assays used as blank). The magnetic
field was generated by two magnetite plates (Figure 1) and standardized as a function of distance versus
number of magnetic plates (Figure 2). The magnetic field was of 500 gauss in the central part between the
two magnetic plates.
RESULTS: The preliminary results show a visible increase in the halo formed due to phospholipase
production, suggesting that the exposition to a magnetic field can enhance the expression of this virulence
factor
Personality and well-being in adolescents
Different profiles of the character dimensions of self-directedness, cooperativeness and self-transcendence result in different levels of wellbeing among adults. However, the description of the multidimensional character profiles on adolescents’ composite wellbeing remains unexplored. This study builds on previous studies with adults, and examines the linear and non-linear associations between the dimensions of the psychobiological model of personality and well-being in adolescents. Participated in this study 1540 adolescents (M=15.44, SD=1.731). Personality was assessed using the Temperament and Character Inventory (TCI). Well-being was evaluated in a composite perspective: satisfaction with social support, health-related quality of life, satisfaction with life and affect. Variable-centered and individual-centered analyses were performed.Self-directedness was strongly associated with all dimensions of affective and cognitive well-being regardless of the other two character traits. Cooperativeness was associated with non-affective well-being and with positive affect, but only when associated to elevation of Self-directedness and Self-transcendence. Self-Directedness and Cooperativeness explained 15.5% of the non-affective well-being variance. Self-Directedness and Self-Transcendence explained 10.4% of the variance in affective well-being. This study confirms the tendencies found in previous studies with adults from other societies, where each character dimension gives an independent contribution to well-being depending on the interactions with other Character dimensions. Also, this study highlights the importance of considering the non-linear influences of the character dimensions in understanding of adolescents’ wellbeing. These results have strong implications for youth positive mental health promotion, including for school-based policies and practices
Effect of antifungal agents on non-Candida albicans Candida species enzymes secretion
The infective ability of Candida species depends on specific virulence mechanisms that confer the ability to colonize host surfaces, to invade deeper host tissue or to evade host defences. During the pathogenic process many virulence attributes may be involved including, production of extracellular proteases and haemolytic activity. Nevertheless, in vitro studies have indicated that antifungal agents could be able to influence the enzymatic activity of Candida species. Therefore, the purpose of this work was to investigate the action of antifungals on proteinase and haemolytic activity of Candida species. This study was conducted with C. albicans (1), C. glabrata (4), C. parapsilosis (5) and C. tropicalis (6) recovered from different body sites (blood, oral, vaginal and urinary tract). Four reference strains of C. albicans ATCC 90028, C. glabrata ATCC 2001, C. parapsilosis ATCC 22019 and C. tropicalis ATCC 750 were also examined. The susceptibility to fluconazole and amphotericin B was determined by the microdilution test in order to allow the determination of the minimal inhibitory concentrations (MIC) and the maximum antifungal concentration (MAC). Then, the proteinase and hemolytic activity was determined for yeasts grown at MIC and MAC. It was observed that all Candida species assayed were sensible to both antifungal agents. Concerning the antifungal effect on enzymatic activity of Candida species, C. parapsilosis from candiduria presented a decreased proteinase and haemolysin activity for both MIC and MAC of both antifungal agents. Moreover, the other species presented differences in terms of production of proteinase and haemolysin at MIC and MAC. Candida albicans reference strain presented lower proteinase activity at MIC of fluconazole (46.7%) but presented higher activity for MAC (61.9%) in comparison to the control (60%). Furthermore, regarding haemolysin activity there were isolates that expressed high levels of enzymes in the presence of both antifungals such as: C. glabrata from urine and from vaginal tract; and C. tropicalis from urine. Conversely, some clinical isolates, presented low levels of enzymatic activity after contact with the antifungal agents, such as: C. albicans (oral isolate); C. glabrata (oral isolate and vaginal isolate); C. parapsilosis (from urine) and also all C. tropicalis except one urinary isolate.
It was possible to conclude that the proteinase and haemolysin activities were strain and species dependent and no correlation was found among activity profile and the site of isolation. Moreover, fluconazole and amphotericin B were able to influence the tested Candida species enzymatic activity
Insights into Candida tropicalis virulence factors
Candida tropicalis is a common nosocomial species related to candidemia and
candiduria. Several virulence factors seem to be responsible for C. tropicalis
infections, which lead to high mortality. Adhesion to surfaces (medical devices
and host cells) and biofilm formation are considered important factors that
contribute to the development of candidosis. Therefore, adhesion to urinary
catheters and biofilm formation were assessed in an optimized in vitro flow
model, using silicone and latex urinary catheters and artificial urine (AU).
Moreover, biofilm matrices were also evaluated in terms of proteins and
carbohydrates. Regarding adhesion to biotic surfaces, the interaction of C.
tropicalis with host cells was determined using three different human epithelial
cell lines: TCC-SUP (urinary bladder); HeLa (cervical carcinoma) and Caco-2
(colorectal adenocarcinoma). Specifically, the degree of human cells damage
and activity reduction induced by C. tropicalis adhesion and the role of Candida
tropicalis aspartyl proteinases (SAPT) genes expression were assessed.
Additionally, the influence of C. tropicalis biofilm cells with different ages (24 -
120 h) on TCC-SUP cells integrity was also studied. Another important Candida
factor is its resistance to antifungal agents, which was also assessed and
related with the expression of enzymes and hyphae formation.
In summary, C. tropicalis strains were able to form biofilms in AU, in static or
dynamic mode, although, with differences among strains. It is important to
emphasize that human cells response to C. tropicalis adhesion, as well as
SAPs production, is strain and cell line dependent. Additionally, it should be
highlighted that C. tropicalis cells detached from biofilms are able to colonize
human cells and cause injury and reduction of metabolic activity. In addition
SAPT3 was highly expressed compared to other SAPT genes. Therefore, it
should be pointed out that C. tropicalis presented a set of different virulencefactors that might be responsible for its high degree of infection
Effect of itraconazole on Candida glabrata biofilm matrix
The emergence of non-Candida albicans Candida (NCAC) species as a common cause of fungal infection is often
associated with the increasing number of immunocompromised patients, the widespread use of indwelling
medical devices and the decreased susceptibility to azoles. The ability of Candida species to adapt to a variety
of different habitats and to form biofilms is also of major contribution to this increased incidence. Thus, the
aim of this work was to study the influence of the antifungal agent itraconazole on the matrix composition of
Candida glabrata biofilms.
Biofilms of Candida glabrata vaginalstrain 534784 were formed in 6-well plates for 24h. Then, fresh RPMI1640/
MOPS medium (control biofilms) and itraconazole (256μg/mL) were added to the previously formed 24h
biofilms. After 48h of exposure to these components, biofilms were scraped from the 6-well plates and the
extracellular matrix extracted by sonication. The protein and carbohydrate content of the biofilm matrix
were determined using a BCA kit and the Dubois method, respectively. The analysis of matrix composition of
biofilms exposed to itraconazole showed an increase in both protein and carbohydrate content comparatively
to the control.
The results indicate that the presence of itraconazole leads to an increase in the production of extracellular
matrix components in Candida glabrata biofilms
The role of antifungals agents on Candida glabrata biofilms matrix composition
Candida glabrata was considered, for years, a relatively non-pathogenic saprophyte of the normal flora of healthy individuals and as no causative agent of serious infection in humans. However, its high mortality rate and its quick spread confirm the opposite. In fact, due to the widespread and increased use of immunosuppressive therapy together with broad-spectrum antifungal treatments, the frequency of mucosal and systemic infections caused by C. glabrata has increased significantly. Furthermore, biofilms are described as surface associated communities of microorganisms within an extracellular matrix, generally composed of carbohydrate and proteins. Biofilm formation is an important virulence factor for a number of Candida species, as it confers significant resistance to antifungal therapy by limiting the penetration of substances through the matrix and protecting cells from host immune responses. Moreover, little is known about the role of antifungals on C. glabrata biofilms. Thus, the aim of this work was to study the role of fluconazole, itraconazole and amphotericin B on 24 h pre-formed C. glabrata biofilms and specially on their matrix composition.
A total of 3 C. glabrata strains isolated from oral, urinary and vaginal tract were used, as well as a reference strain from ATCC (C. glabrata 2001). Biofilms were formed on 12-well plates on RPMI 1640, during 24h at 37ºC and 120 rpm. Then, the antifungal agents (fluconazole, amphotericin B and itraconazole) were added to the previously formed biofilms. After 48 h of action of each antifungal agent, the biofilms were evaluated in terms of total biomass by crystal violet staining and number of viable cells by colony forming units (CFUs). The role of itraconazole on biofilms of the clinical vaginal isolate (C. glabrata 534784) was also examined in terms of matrix composition. For this, biofilms were formed in 6-well plates during 24h and, after 48h of exposure to itraconazole, were scraped from the wells and the extracellular matrix was extracted by sonication. Biofilm matrix contents in proteins and carbohydrates were determined using the BCA kit and the Dubois method, respectively.
The results showed that, amphotericin B and fluconazole were able to cause a significant decreased on total biomass and CFUs of C. glabrata. However, itraconazole was not able to affect biofilms, except for the clinical vaginal isolate (C. glabrata 534784) at 256 µg/mL point concentration, which presented an increase in total biofilm biomass. Candida glabrata 534784 biofilms matrix exposed to itraconazole (256 µg/mL) presented an increase in proteins content but not in carbohydrate comparatively to the control.
In summary, fluconazole and amphotericin B were able to significantly decrease the pre-formed biofilms of C. glabrata strains. Furthermore, the highest amount of total biofilm biomass of the vaginal isolate seems to be due to the increased protein content in its matrix
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