Actividad antifúngica del aceite volátil de Hedyosmum sp, frente a especies del género Candida / Antifungal activity of the volatile oil of Hedyosmum sp, Against species of the genus Candida

El objetivo del estudio fue determinar la actividad antifúngica del aceite volátil de las partes aéreas de la especie vegetal Hedyosmum sp., frente al complejo Candida albicans, C. glabrata, C. tropicalis y C. parapsilosis. El material vegetal se recolectó del bosque natural Jacarón, Provincia de Chimborazo, Ecuador. La extracción del aceite volátil se realizó por hidrodestilación, obteniéndose un rendimiento de 0,09%. La actividad antifúngica fue estudiada mediante el método de difusión en agar y los resultados se interpretaron mediante detección-medición de halos de inhibición y concentración mínima inhibitoria. El estudio se realizó partiendo del aceite puro y diluciones con dimetil sulfóxido. Los resultados se validaron mediante controles positivos (Fluconazol) y negativos (dimetil sulfóxido). El aceite puro mostró actividad antifúngica frente a C. albicans, C. tropicalis, C. parapsilosis, pero no frente a C. glabrata. Mientras que, la actividad antifúngica determinada empleando diluciones del aceite permitió establecer la concentración mínima inhibitoria para C. tropicalis, C. parapsilosis, en 0,25x106 µg/mL y para C. albicans en 0,5x106 µg/mL. Estos resultados concluyeron que el aceite volátil de Hedyosmum sp., presenta actividad antifúngica poco significativa frente a tres de las cuatro especies de Candida estudiadas

The objective of the study was to determine the antifungal activity of the volatile oil of the aerial parts of the plant species Hedyosmum sp., against Candida albicans, C. glabrata, C. tropicalis and C. parapsilosis complex. The plant material was collected from the Jacarón natural forest, Chimborazo Province, Ecuador. The extraction of the essential oil was carried out by hydro-distillation, obtaining a yield of 0.09%. Antifungal activity was studied by means of the diffusion in agar method and the results were interpreted by detection-measurement of inhibition halos and minimum inhibitory concentration. The study was carried out starting from the pure oil and dilutions with dimethyl sulfoxide. The results were validated by positive controls (Fluconazole) and negative controls (dimethyl sulfoxide). The pure oil showed antifungal activity against C. albicans, C. tropicalis, and C. parapsilosis complex, but not against C. glabrata. While, the antifungal activity determined using dilutions of the oil allowed establishing the minimum inhibitory concentration for C. tropicalis, C. parapsilosis complex, at 0,25x106 µg/mL and for C. albicans at 0,5x106 µg/mL. These results concluded that the volatile oil of Hedyosmum sp., Presents little antifungal activity against three of the four Candida species studied

The production of yeast cell wall using an agroindustrial waste influences the wall thickness and is implicated on the aflatoxin B1 adsorption process.

The objectives of this study were: to evaluate the use of dry distillery grain soluble extract - DDGse to produce yeast biomass and to obtain cell wall (CW), to use the CW as an aflatoxin B1 (AFB1) adsorbent, to study the variation in the composition and thickness of the CW under the influence of DDGse to evaluate their implication on the adsorption process using transmission electron microscopy (TEM) and fourier-transform infrared spectroscopy (FITR). The production of biomass and CW were variable. The CW thickness values showed that S. boulardii strain grown in yeast extract peptone dextrose (YPD) or DDGse medium, with no significant differences observed. The thickness of the CW for S. cerevisiae (RC012 and VM014) were increased when the cells were grown in DDGse medium, the thickness was almost double compared to the values obtained in YPD medium. The spectra IR of each CW in the two culture media shown regions corresponding to polysaccharides, proteins and lipids. Cells grown in DDGse medium adsorbed more AFB1 than those grown in YPD. The CW adsorbed more AFB1 than the same amount of whole cell. Future studies should be done to determine the type of carbohydrates and the relationship between chitin - beta glucans responsible for mycotoxin adsorption.

Exploring physical and chemical properties in new multifunctional indium-, bismuth-, and zinc-based 1D and 2D coordination polymers.

Main group element coordination polymers (MGE-CPs) are important compounds for the development of multifunctional materials. However, there has been a shortage of studies regarding their structural, optical, catalytic, mechanical, and antibacterial properties. This work presents an exhaustive study of a set of crystalline MGE-CPs obtained from bismuth and indium metals and iminodiacetate, 1,2,4,5-benzenetetracarboxylate, and 2,2'-bipyridine as building blocks. An in-depth topological analysis of the networks was carried out. Additionally, nanoindentation studies were performed on two representative low-dimensional compounds in order to find the relationships between their structural features and their intrinsic mechanical properties (hardness and elasticity). The solid-state photoluminescence (SSPL) properties were also studied in terms of excitation, emission, lifetimes values, and CIE chromaticites. Moreover, the heterogeneous catalytic activities of the compounds were evaluated with the cyanosilylation reaction using a set of carbonylic substrates under solvent-free conditions. Finally, the inhibitory effect of the Bi-CPs on the growth of microorganisms such as Escherichia coli, Salmonella enterica serovar Typhimurium, and Pseudomonas aeruginosa, which are associated with relevant infectious diseases, is reported.

Negligible effects of tryptophan on the aflatoxin adsorption of sodium bentonite.

The main objective of this study was to determine if the competitive adsorption of tryptophan (Trp) and aflatoxin B1 (AFB1) could potentially affect the ability of a sodium bentonite (NaB) to prevent aflatoxicosis in monogastric animals. The adsorption of Trp and AFB1 on this adsorbent is fast and could be operating on the same time-scale making competition feasible. In vitro competitive adsorption experiments under simulated gastrointestinal conditions were performed. A high affinity of the clay for Trp and NaB was observed. The effect of an excess of KCl to mimic the ionic strength of the physiological conditions were also investigated. A six-times decrease in the Trp surface excess at saturation was observed. A similar behaviour was previously found for AFB1 adsorption. Taking into account the amount of Trp adsorbed by the clay and the usual adsorbent supplementation level in diets, a decrease in Trp bioavailability is not expected to occur. Tryptophan adsorption isotherms on NaB were 'S'-shaped and were adjusted by the Frumkin-Fowler-Guggenheim model. The reversibility of the adsorption processes was investigated in order to check a potential decrease in the ability of NaB to protect birds against chronic aflatoxicoses. Adsorption processes were completely reversible for Trp, while almost irreversible for AFB1. In spite of the high affinity of the NaB for Trp, probably due to the reversible character of Trp adsorption, no changes in the AFB1 adsorption isotherm were observed when an excess of the amino acid was added to the adsorption medium. As a consequence of the preferential and irreversible AFB1 adsorption and the reversible weak binding of Trp to the NaB, no changes in the aflatoxin sorption ability of the clay are expected to occur in the gastrointestinal tract of birds.

Natural co-occurrence of fungi and mycotoxins in poultry feeds from Entre Ríos, Argentina.

A total of 120 pelleted poultry feed samples from Entre Ríos Province, Argentina, were evaluated. The aims were to investigate (1) the presence of relevant toxigenic fungi, as well as to determine the ability to produce aflatoxins (AFs) by Aspergillus section Flavi isolated strains; and (2) the natural co-occurrence of AFs, fumonisins (FBs), gliotoxin, diacetoxyscirpenol (DAS), HT-2 and T-2 toxin by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Total fungal counts were below the established value (1 × 104 CFU g⁻¹). Aspergillus flavus and A. parasiticus were the only aflatoxigenic species isolated. Co-occurrence of fumonisin B1 (FB1), HT-2 and T-2 toxin was detected in 100% of the feeds, with mean levels from 4502 to 5813; 6.7 to 21.6 and 19.6 to 30.3 µg kg⁻¹, respectively. A large number of starter samples were co-contaminated with aflatoxin B1 (AFB1), FB1, HT-2 and T-2 toxins. Gliotoxin and DAS were not found in this survey.

Gliotoxin contamination in and pre- and postfermented corn, sorghum and wet brewer's grains silage in Sao Paulo and Rio de Janeiro State, Brazil.

AIMS: The aim of this study was to determine total fungal counts and the relative density of Aspergillus fumigatus and related species in silage samples intended for bovines before and after fermentation as well as to monitor the natural occurrence of gliotoxin in silage samples (pre- and postfermentation). METHODS AND METHODS: The survey was performed in farms located in São Paulo and Rio de Janeiro States in Brazil. In addition, the ability of A. fumigatus strains and related species strains to produce gliotoxin was also evaluated. A total of 300 samples were taken, immediately after opening of the silo (3-5 months) and during the ensiling period. Fungal counts were done by the surface-spread method. Gliotoxin production ability of isolates and natural contamination were determined by HPLC. RESULTS: All postfermented samples had a total number of moulds exceeding 1 × 10(4) CFU g(-1), with Aspergillus sp. as the most prevalent genus. Frequency of strains, among A. fumigatus and related species, was able to produce gliotoxin was similar in pre- and postfermented samples, except for sorghum, which showed differences between both kinds of samples. The highest toxin levels were produced by strains isolated from postfermented samples. More than 50% of the samples showed gliotoxin contamination levels that exceeded concentrations known to induce immunosuppressive and apoptotic effects in cells. CONCLUSIONS: The present data suggest that care should be taken because gliotoxin contamination in feedstuffs could affect productivity and also present a health risk for herds. SIGNIFICANCE AND IMPACT OF THE STUDY: Gliotoxin was found at quite important concentrations levels in pre- and postfermented substrates and its presence could therefore probably affect the productivity and health of herds. Current conservation and management practices do not avoid contamination with A. fumigatus on silage. Therefore, farm workers should be adequately protected during its handling.

Combined effects of aflatoxin B1 and corticosterone treatment on selected performance indices and liver histopathology in Japanese quail.

Animal feed may be contaminated with different mycotoxins, with aflatoxin B(1) (AFB(1)) being a very common and toxic compound. Considering that birds normally have to cope with different stressful situations at the same time, the present study aims to evaluate the effects of feed contamination with AFB(1) in combination with corticosterone treatment in drinking water (a model to induce physiological stress in birds) on selected performance indices: BW, feed conversion, egg production, and macroscopic and microscopic liver alterations. At 5 wk of age, quails were randomly assigned to 1 of 6 dietary treatment groups that resulted from the combination of the presence or absence of corticosterone in drinking water (5 mg/L) with the presence or absence of AFB(1) contamination (0, 100, or 500 µg/kg). The animals remained in these treatments from 5 to 11 wk of age. There were 6 replicates per treatment, each containing 2 males and 2 females. Contamination with 100 µg of AFB(1) per kilogram of feed induced no changes in BW, feed conversion, and egg production parameters. Quail fed with 500 µg of AFB(1) per kilogram of feed showed significant decreases in BW and feed consumption compared with their control counterparts. Corticosterone in combination with 500 µg of AFB(1) per kilogram of feed intensified the negative effects observed on BW and feed consumption and also had negative effects on feed conversion rate and egg production parameters, suggesting that the adverse effects of contamination with AFB(1) are intensified in situations of chronic stress. Quail treated with 500 µg of AFB(1) per kilogram showed hepatocytes with degree 1 and 2 lesions, and all quail treated with 500 µg of AFB(1) per kilogram of feed in combination with corticosterone showed degree 2 liver lesions (i.e., hepatocytes with fatty macro and microvacuoles and necrosis). This result is also consistent with the hypothesis that chronic stress exacerbates the effect of AFB(1) contamination. In conclusion, this study suggests that the negative effects of AFB(1) contamination are increased when overlapped with chronic stressful stimulation.

Effect of low levels of aflatoxin B1 on performance, biochemical parameters, and aflatoxin B1 in broiler liver tissues in the presence of monensin and sodium bentonite.

Aflatoxins (AF) are a major problem in broiler production and are significant economic and public health burdens worldwide. A commercial sodium bentonite (Na-B) adsorbent was used to prevent the effect of AF [50 µg of aflatoxin B1 (AFB1)/kg of feed] in broiler productivity, biochemical parameters, macroscopic and microscopic liver changes, and AFB1 liver residues. The influence of Na-B (0.3%) and monensin (MON, 100 mg/kg), alone or in combination, was investigated in depth. The dietary treatments were as follows: treatment (T) 1: basal diet (B); T2: B + MON; T3: B + Na-B; T4: B + Na-B + MON; T5: B + AFB1; T6: B + AFB1 + Na-B + MON; T7: B + AFB1 + MON; T8: B + AFB1 + Na-B. Birds were fed dietary treatments for 28 d (d 18 to 46). No significant differences (P < 0.05) were observed among treatments with respect to broiler performance, biochemical parameters, or relative liver weights. With the exception of T8, all livers showed histopathological alterations, with accumulation of fat vacuoles. The normal appearance of livers from T8 showed the protective effect of Na-B against aflatoxicosis. The residual AFB1 levels in livers from T5 to T8 ranged from 0.2 to 1.0 ng/g and were higher in livers from T6 (P < 0.05). Results of this study indicate a competition between AFB1 and MON for adsorption sites on Na-B when feed contains low levels of the toxin, indicating a nonselective adsorption capacity of this particular Na-B. In addition, significant levels of AFB1 in livers indicate that this determination is an important technique not only for diagnosis of aflatoxicosis in broilers, but also for quality control of avian products.

Naturally occurring aflatoxin M(1) in raw bulk milk from farm cooling tanks in Argentina.

The aim was to carry out a survey of aflatoxin M(1) (AFM(1)) in raw whole milk from bulk tanks. The sample collection was performed in farms located in one the most important milk-production zones in the centre of Argentina. A total of 94 samples of milk from 47 dairy farms were analysed. AFM(1) analysis involved the use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) with prior purification of the extracts using immunoaffinity columns. AFM(1) incidence in raw milk was high as 63.8% and levels were between not detected to 0.07 microg l(-1). Several contaminated samples (39%) were over the European Commission limit for infant milk (0.025 microg l(-1)), although none of samples were above Argentine legislation. Estimates of AFM(1) intake were assessed for different age populations. The average AFM(1) estimated daily intakes were 1.6, 0.5, 0.17 ng kg(-1) body weight day(-1) for 4-year-old babies, young children, and adults, respectively. All tested farms used pastures and silages at similar composition. Even though some farms (13) employed high-risk supplementary feeds, such as peanut pod and/or cotton seed, no statistically significant differences were observed between groups. Information from AFM(1) levels in milk in Argentina is limited. A systematic AFM(1) monitoring programme must be performed by means of accurate and reliable analytical techniques as a strategy for protecting milk consumers.

Reversible breaking and forming of metal-ligand coordination bonds: temperature-triggered single-crystal to single-crystal transformation in a metal-organic framework.

Yb(C(4)H(4)O(4))(1.5)] undergoes a temperature-triggered single-crystal to single-crystal transformation. Thermal X-ray single-crystal studies showed a reversibly orchestrated rearrangement of the atoms generated by the breaking/formation of coordination bonds, in which the stoichiometry of the compound remains unchanged. The transformation occurs on heating the crystal at approximately 130 degrees C. This uncommon behavior was also studied by thermal methods, FTIR spectroscopy, and thermodiffractometry. Both polymorphs, alpha (room-temperature form) and beta (high-temperature form), are proven to be active heterogeneous catalysts; the higher catalytic activity of beta is owed to a decrease in the Yb coordination number. A mechanism based on spectroscopic evidence and involving formation of the active species Yb-O-OH is proposed for the sulfide oxidation.

Molecular determinants of invasion in endometrial cancer.

Endometrial carcinoma is the most common gynaecological malignancy in the western world and the most frequent among infiltrating tumours of the female genital tract. Despite the characterisation of molecular events associated with the development of endometrial carcinoma, those associated with the early steps of infiltration and invasion in endometrial cancer are less known. Deep myometrial invasion correlates with more undifferentiated tumours, lymph-vascular invasion, node affectation and decreased global survival. In this review we present an overview of the molecular pathology of myometrial infiltration that defines the initial steps of invasion in endometrial cancer. Down-regulation of E-cadherin as a main player of epithelial to mesenchymal transition, as well as modifications on other molecules involved in cell-cell contacts, render cells with a migratory phenotype. In addition, altered signalling pathways and transcription factors associate with myometrial invasion, histologic grade and metastasis.

Comparison between IgG and F(ab')(2) polyvalent antivenoms: neutralization of systemic effects induced by Bothrops asper venom in mice, extravasation to muscle tissue, and potential for induction of adverse reactions.

Whole IgG and F(ab')(2) equine-derived polyvalent (Crotalinae) antivenoms, prepared from the same batch of hyperimmune plasma, were compared in terms of neutralization of the lethal and defibrinating activities induced by Bothrops asper venom, their ability to reach the muscle tissue compartment in envenomated mice, and their potential for the induction of adverse reactions. Both preparations were adjusted to the same potency against the lethal effect of B. asper venom in experiments involving preincubation of venom and antivenom. Then, "rescue" experiments were performed, i.e. antivenom was administered either intravenously or intramuscularly at various times after envenomation. IgG and F(ab')(2) antivenoms were equally effective in the neutralization of lethality, both being more effective when administered i.v. than after i.m. injection. Neutralization decreased as the time lapse between envenomation and treatment increased. No significant differences were observed in the ability of antivenoms to neutralize defibrinating activity of B. asper venom in experiments involving independent injection of venom and antivenoms. There was a much higher accumulation of equine antibodies in muscle tissue that had been injected with B. asper venom than in non-envenomated tissue, indicating that venom-induced microvessel damage probably favors a prominent and similar extravasation of both IgG and F(ab')(2) antibodies. This may explain the similar effectiveness of both types of antivenom in previously reported studies on the neutralization of venom-induced local tissue damage. Both IgG and F(ab')(2) antivenoms activate human complement in vitro and induce an anti-equine immunoglobulin response in mice, indicating that Fc removal per se does not eliminate the potential for inducing adverse reactions. However, IgG antivenom had higher anticomplementary activity and induced a stronger anti-immunoglobulin response than F(ab')(2) antivenom.

[Vegetal foreign body in the airway: an unusual cause of hemoptysis in childhood. Clinical case]. / Cuerpo extraño vegetal en la vía aerea: una causa poco frecuente de hemoptisis en la niñez. Caso clínico.

Hemoptysis is an infrequent symptom in childhood and potentially life threatening. The most common causes in this age group are bronchiectasis secondary to cystic fibrosis, cardiovascular and pulmonary congenital anomalies and a miscellaneous group of causes including retained intrabronchial aspirated foreign bodies. We report a previously healthy 5-year-old girl with recurrent pneumonias associated with episodes of hemoptysis. She was admitted in our institution to investigate the persistence of hemoptysis. Based on clinical history, aspiration of a vegetal foreign body was postulated as the etiology and it was confirmed in the pathological examination after surgical exploration, with pulmonary lobe resection. The importance of a good history taking in pediatric hemoptysis is emphasized.