Nanotechnology-based Drug Delivery Systems for Dermatomycosis Treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Amphotericin B Microemulsion Reduces Toxicity and Maintains the Efficacy as an Antifungal Product

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pothomorphe umbellata: Antifungal activity against strains of Trichophyton rubrum

Trichophyton rubrum is a dermatophyte, which can cause infections in human skin, hair and nail. Pothomorphe umbellata (L.) Miq. (Piperaceae) is a native Brazilian plant, in which phytochemical studies have demonstrated the presence of steroids, 4-nerolidylcatechol, sesquiterpenes and essential oils. The objective of this study was to analyze the in vitro activity of extracts and fractions of P. umbellata on resistant strains of T. rubrum. The microdilution plate method was utilized to test Tr1, H6 and Delta TruMDR2 strains of T rubrum; Delta TruMDR2 strain was obtained from H6 by TruMDR2 gene rupture, which is involved in multiple drugs resistance. The highest antifungal activity to all strains was observed for dichloromethane and hexane fractions of the 70% ethanolic extract which showed minimal inhibitory concentration (MIC) and minimal fungicide concentration (MFC) of 78.13 mu g/mL. This antifungal activity was also obtained by 70% ethanolic extract, which presented MIC and MFC of 78.13 mu g/mL to Delta TruMDR2, whereas the MIC values for Tr1 and H6 were 78.13 and 156.25 mu g/mL, respectively. Our results suggest the potential for future development of new antifungal drugs from P umbellata, especially to strains presenting multiple resistance. (C) 2012 Elsevier Masson SAS. All rights reserved.

Dexamethasone-induced insulin resistance is associated with increased connexin 36 mRNA and protein expression in pancreatic rat islets

Augmented glucose-stimulated insulin secretion (GSIS) is an adaptive mechanism exhibited by pancreatic islets from insulin-resistant animal models. Gap junction proteins have been proposed to contribute to islet function. As such, we investigated the expression of connexin 36 (Cx36), connexin 43 (Cx43), and the glucose transporter Glut2 at mRNA and protein levels in pancreatic islets of dexamethasone (DEX)-induced insulin-resistant rats. Study rats received daily injections of DEX (1 mg/kg body mass, i.p.) for 5 days, whereas control rats (CTL) received saline solution. DEX rats exhibited peripheral insulin resistance, as indicated by the significant postabsorptive insulin levels and by the constant rate for glucose disappearance (K-ITT). GSIS was significantly higher in DEX islets (1.8-fold in 16.7 mmol/L glucose vs. CTL, p < 0.05). A significant increase of 2.25-fold in islet area was observed in DEX vs. CTL islets (p < 0.05). Cx36 mRNA expression was significantly augmented, Cx43 diminished, and Glut2 mRNA was unaltered in islets of DEX vs. CTL (p < 0.05). Cx36 protein expression was 1.6-fold higher than that of CTL islets (p < 0.05). Glut2 protein expression was unaltered and Cx43 was not detected at the protein level. We conclude that DEX-induced insulin resistance is accompanied by increased GSIS and this may be associated with increase of Cx36 protein expression.

Increased pancreatic islet mass is accompanied by activation of the insulin receptor substrate-2/serine-threonine kinase pathway and augmented cyclin D(2) protein levels in insulin-resistant rats

It is well known that glucocorticoids induce peripheral insulin resistance in rodents and humans. Here, we investigated the structural and ultrastructural modifications, as well as the proteins involved in beta-cell function and proliferation, in islets from insulin-resistant rats. Adult male Wistar rats were made insulin resistant by daily administration of dexamethasone (DEX; 1mg/kg, i.p.) for five consecutive days, whilst control (CTL) rats received saline alone. Structure analyses showed a marked hypertrophy of DEX islets with an increase of 1.7-fold in islet mass and of 1.6-fold in islet density compared with CTL islets (P < 0.05). Ultrastructural evaluation of islets revealed an increased amount of secreting organelles, such as endoplasmic reticulum and Golgi apparatus in DEX islets. Mitotic figures were observed in DEX islets at structural and ultrastructural levels. Beta-cell proliferation, evaluated at the immunohistochemical level using anti-PCNA (proliferating cell nuclear antigen), showed an increase in pancreatic beta-cell proliferation of 6.4-fold in DEX islets compared with CTL islets (P < 0.0001). Increases in insulin receptor substrate-2 (IRS-2), phosphorylated-serine-threonine kinase AKT (p-AKT), cyclin D(2) and a decrease in retinoblastoma protein (pRb) levels were observed in DEX islets compared with CTL islets (P < 0.05). Therefore, during the development of insulin resistance, the endocrine pancreas adapts itself increasing beta-cell mass and proliferation, resulting in an amelioration of the functions. The potential mechanisms that underlie these events involve the activation of the IRS-2/AKT pathway and activation of the cell cycle, mediated by cyclin D(2). These adaptations permit the maintenance of glycaemia at near-physiological ranges.

Increased glial-derived neurotrophic factor in the small intestine of rats infected with the tapeworm, Hymenolepis diminuta

The neurotrophin, glial-derived neurotrophic factor (GDNF), is essential for the development of the enteric nervous system (ENS) in both the embryo and neonate and may be important for maintenance and plasticity of ENS. The tapeworm, Hymenolepis diminuta, altered the number of cells containing GNDF in the host's jejunum and ileum. Numbers and locations of GDNF-containing cells were determined by applying monoclonal anti-GDNF antibody to intestinal segments collected from infected and uninfected age-matched rats during the initial 34 days post-infection (dpi). Most cells staining positive for GDNF were present in the lamina propria of the jejunum and ileum from both infected and uninfected rats. The co-localization of staining by the antibodies, anti-GDNF and anti-ED2 (a nuclear specific antibody for resident macrophages) indicated that at least 74% of the cells staining for GDNF were macrophages. Mast cells did not stain with the anti-GDNF antibody. The increased number of GDNF+ cells in the infected rat intestine suggests that this neurotrophin may play a role in the neural and mucosal responses to lumenal tapeworm infection.

Myocardial dysfunction with increased ventricular compliance in volume overload hypertrophy

The aim this study was to evaluate systolic and diastolic function in volume overload induced myocardial hypertrophy in rats.Volume overload myocardial hypertrophy was induced in thirteen male Wistar rats by creating infrarenal arteriovenous fistula (AVF). The results were compared with a SHAM operated group (n = 11). Eight weeks after surgery, tail-cuff blood pressure was recorded, then rats were sacrificed for isolated heart studies using Langendorffs preparation.AVF rats presented increased left and right ventricular weights, compared to controls. The increased normalized ventricular volume (V0/LVW, 0.141 +/- 0.035 mL/g vs. 0.267 +/- 0.071 mL/g, P < 0.001) in the AVF group indicated chamber dilation. Myocardial hydroxyproline concentration remained unchanged. There was a significant decrease in +dP/dt (3318 +/- 352 mm Hg s(-1) vs. 2769 +/- 399 mm Hg s(-1); P=0,002), end-systolic pressure-volume relation (246 +/- 56 mm Hg mL(-1) vs. 114 +/- 63 mm Hg mL(-1);, P < 0,001), and -dP/dt (1746 +/- 240 min Hg s(-1) vs. 1361 +/- 217 mm Hg s(-1), P < 0.001) in the AVF group, which presented increased ventricular compliance (Delta V-25: SHAM=0.172 +/- 0.05 mL vs. AVF=0.321 +/- 0.072 mL, P < 0.001) with preserved myocardial passive stiffness (Strain(25): SHAM=13.5 +/- 3.0% vs. AVF=12.3 +/- 1.9%, P > 0.05).We conclude that volume-overload induced hypertrophy causes myocardial systolic and diastolic dysfunction with increased ventricular compliance. These haemodynamic features help to explain the long-term compensatory phase of chronic volume overload before transition to overt congestive heart failure. (c) 2006 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.

Increased production of hydrogen peroxide by peripheral blood monocytes associated with smoking exposure intensity in smokers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Early echocardiographic predictors of increased left ventricular end-diastolic pressure three months after myocardial infarction in rats

Background: The objective of this study was to determine the early echocardiographic predictors of elevated left ventricular end-diastolic pressure (LVEDP) after a long follow-up period in the infarcted rat model.Material/Methods: Five days and three months after surgery, sham and infarcted animals were subjected to transthoracic echocardiography. Regression analysis and receiver-operating characteristic (ROC) curve were performed for predicting increased LVEDP 3 months after MI.Results: Among all of the variables, assessed 5 days after myocardial infarction, infarct size (OR: 0.760; CI 95% 0.563-0.900; p=0.005), end-systolic area (ESA) (OR: 0.761; Cl 95% 0.564-0.900; p=0.008), fractional area change (FAC) (OR: 0.771; CI 95% 0.574-0.907; p=0.003), and posterior wall-shortening velocity (PWSV) (OR: 0.703; CI 95% 0.502-0.860; p=0.048) were predictors of increased LVEDP. The LVEDP was 3.6 +/- 1.8 mmHg in the control group and 9.4 +/- 7.8 mmHg among the infarcted animals (p=0.007). Considering the critical value of predictor variables in inducing cardiac dysfunction, the cut-off value was 35% for infarct size, 0.33 cm(2) for ESA, 40% for FAC, and 26 mm/s for PWSV.Conclusions: Infarct size, FAC, ESA, and PWSV, assessed five days after myocardial infarction, can be used to estimate an increased LVEDP three months following the coronary occlusion.

Prevalence and antifungal susceptibility of Candida parapsilosis complex isolates collected from oral cavities of HIV-infected individuals

At present, few data are available on the prevalence and antifungal susceptibility of Candida parapsilosis complex isolates from HIV-infected individuals. The C. parapsilosis complex comprises three species, C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. Fifteen of 318 Candida isolates were identified as members of the C. parapsilosis complex by PCR and restriction fragment length polymorphism (RFLP). The prevalence of C. parapsilosis complex isolates was 4.7 %, 2.2 % being identified as C. parapsilosis sensu stricto and 2.5% as C. metapsilosis, while no C. orthopsilosis was isolated. This is believed to be the first study that has identified isolates of C. metapsilosis obtained from the oral cavity of HIV-infected individuals. Antifungal susceptibility tests indicated that all the isolates were susceptible to amphotericin B (AMB), fluconazole (FLC), ketoconazole (KTC), itraconazole (ITC), voriconazole (VRC) and caspofungin (CASPO). Although isolates of C. parapsilosis sensu stricto and C. metapsilosis were susceptible to FLC, isolates of C. metapsilosis showed a tendency for higher MICs (>= 1.0 mu g ml(-1)). Based upon the frequency of candidiasis and the fact that certain isolates of the C. parapsilosis complex respond differently to FLC therapy, our data may be of therapeutic relevance with respect to susceptibility and potential resistance to specific antifungal agents. Our data suggest that C. metapsilosis can be a human commensal; its importance as a pathogen has yet to be confirmed.

Increased Reactive Oxygen Species and Tumor Necrosis Factor-Alpha Production by Monocytes are Associated with Elevated Levels of Uric Acid in Pre-Eclamptic Women

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Increased interleukin-10 associated with low IL-6 concentration correlated with greater survival rates in mice infected by rabies virus vaccinated against it and immunomodulated with P-acnes

Macrophage activity, cytokines serum concentration, serum neutralizing antibodies and lethality by rabies were evaluated in swiss mice experimentally infected with street rabies virus and submitted or not to antirabies vaccination and immunomodulation with P. acnes. Animals were killed at different times and serum was collected in order to evaluate cytokines concentration; peritonial and splenic macrophages were collected for macrophage activity evaluation. Greater survival rates higher IL-10 and low IL-6 serum concentration were observed in vaccinated animals treated using P. acnes. (C) 2004 Elsevier Ltd. All rights reserved.