125 research outputs found

    Neonatal Isolation Stress Inhibits Pre-Weaning Weight Gain and Mild-Stressor Induced Locomotor Activity in Early Adolescent Male and Female Rats

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    The present study looked at the effects of neonatal isolation, an early life stress experience, in male and female early adolescent rats, an age which is underrepresented in the early stress literature. Four stress-sensitive indices were assessed: weight gain during the pre-weaning period, open field activity, and locomotor activity in response to two mild stressors: exposure to a novel environment, and a single IP saline injection. Rats in the neonatal isolation condition were removed from dam and littermates on postnatal days 2-9 in accord with the procedure used by Kehoe et al. (1995); behavioral testing occurred on PN25-PN30 during the early adolescent period. It was found that neonatally isolated pups weighed less than non-isolate controls on each of three measurement days (PN7, PN14, PN21) throughout the pre-weaning period. Further, neonatal isolation experience consistently reduced horizontal locomotor activity measured in the open field, in a novel environment, and following a single mild acute stressor. On some measures, behavior reflected greater impact of NI in males compared with NI females, suggesting that the effects of NI in early adolescent rats may be sexually dimorphic

    Contribución al estudio de la resistencia a diversos agentes antimicrobianos en cepas salvajes de Pseudomonas aeruginosa aisladas de aguas y suelos de Cataluña

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    Tesi de Llicenciatura per a la obtenció del Grau de Farmàcia. Facultat de Farmàcia. Universitat de Barcelona. Director: Ma. Dolores Simón Pujol. 1977

    Aislamiento y caracterización de Pseudomonas aeruginosa procedentes de distintos habitats: aspectos ecológicos y sanitarios

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    [spa] Pseudomonas aeruginosa es un microoganismo Gram-negativo, potencialmente patógeno, agente causal de serias infecciones en el hombre que cursan con gran variedad de síntomas (HOMMA, 1971). Entre sus principales características destacan su elevada resistencia a los agentes antimicrobianos y su potencial metabólico, siendo capaz de utilizar un número muy elevado de compuestos (LIU, 1976; STANIER et al., 1977). La existencia en el medio ambiente de bacterias patógenas multirresistentes, como P. aeruginosa, puede significar un insospechado peligro para el hombre. Las implicaciones de la presencia y origen de estos microorganismos son cuestiones importantes que deben seírcontestadas (COLWELL y SIZEMORE, 1974). Para entender el comportamiento de un microorganismo patógeno oportunista como P, aeruginosa y poderlo combatir de forma efectiva, es necesario estudiar su ciclo y las relaciones que presenta en el medio ambiente, pudiendo llegar de esta forma a conocer sus vías de transmisión (HOADLEY, 1977, YOUNG, 1977). El fin de esta tesis es eliminar algunas barreras existentes en el campo de la Microbiología, presentando una información conjunta esencial para el entendimiento de la P. aeruginosa. En esta memoria se estudian algunos aspectos de su biología, sobre todo los que hacen referencia a su resistencia ante agentes antimicrobianos. Su incidencia y nivel de resistencia puede significar un verdadero reto para la salud pública

    Mezclas cataniónicas BioTS/TS: Nueva aproximación terapéutica antimicrobiana

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    Multilayer emulsions stabilized by vegetable proteins

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    There is great interest in the food, cosmetic and pharmaceutical industry in the use of proteins and polysaccharides as natural hydrocolloids to create novel emulsion systems with improved stability and functionality. For example, the electrostatic interaction between proteins and polysaccharides may be used to form oil-in-water (O/W) emulsions with multilayered interfacial membranes around oil droplets or multilayer emulsions. This type of emulsions have been developed using the layer-by-layer (LbL) technique, which consists of direct adsorption of an oppositely charged polyelectrolyte layer (e.g. polysaccharides) on a primary layer of ionic emulsifiers (e.g. proteins). The polymeric structure and electrical charge of proteins make them a special class of compounds very suitable for its utilization in the LbL technique. In recent years, the utilization of proteins as emulsifier in the food and pharmaceutical industry has been turning towards plants as a preferred alternative to animal-based sources. This article reviews the current understanding of the utilization of different vegetable proteins as emulsifier in order to stabilize O/W multilayer emulsions systems. Additionally, it highlights some potential applications of the multilayer emulsion technology in the industry for improving the stability of emulsions to environmental stresses or and for developing controlled or triggered release systems

    Optimizing the production of the biosurfactant lichenysin and its application in biofilm control

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    Aims: Apply response surface methodology (RSM) to develop and optimize an economical medium for lichenysin production, which is a surfactant produced by Bacillus licheniformis and evaluate the application of lichenysin in the prevention and disruption of pathogenic micro-organism biofilm that creates health problems in the food industry and hospitals. Results: An economical medium containing molasses was optimized to enhance lichenysin production by RSM. A production of 3.2 g l 1 of lichenysin was achieved with an optimum medium containing 107.82 g l 1 of molasses, 6.47 g l 1 of NaNO3 and 9.7 g l 1 of K2HPO4/KH2PO4, in which molasses and phosphate salts had a significant effect on biosurfactant production. Lichenysin was effectively applied in a surface pre-treatment to avoid microbial biofilm development of methicillin-resistant Staphylococcus aureus (MRSA) (68.73%) and Candida albicans (74.35%), with ED50 values of 8.3 and 17.2 lg ml 1 respectively. It was also very efficient in a surface posttreatment to remove biofilms of MRSA (55.74%) and Yersinia enterocolitica (51.51%), with an ED50 of 2.79 and 4.09 lg ml 1 respectively. Conclusions: Lichenysin was found to have notable anti-adhesion activity, being able to prevent and eliminate the biofilm formation by pathogenic strains associated with foodborne illness. This new medium resulted in a fourfold increase in production compared with the nonoptimized medium. Significance and Impact of the Study: Molasses can be regarded as a useful resource for biotechnological applications, such as the production of lichenysin. The use of agro-industrial substrates has an important role in the sustainable and competitive development of several industrial sectors, as well as in industrial residues management. Additionally, lichenysin is particularly effective in preventing biofilm formation by strains problematic for the food industry and in the hospital environment. Lichenysin also efficiently disrupts biofilm

    Unveiling the Membrane and Cell Wall Action of Antimicrobial Cyclic Lipopeptides: Modulation of the Spectrum of Activity

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    Antibiotic resistance is a major public health challenge, and Gram-negative multidrug-resistant bacteria are particularly dangerous. The threat of running out of active molecules is accelerated by the extensive use of antibiotics in the context of the COVID-19 pandemic, and new antibiotics are urgently needed. Colistin and polymyxin B are natural antibiotics considered as last resort drugs for multi-resistant infections, but their use is limited because of neuro- and nephrotoxicity. We previously reported a series of synthetic analogues inspired in natural polymyxins with a flexible scaffold that allows multiple modifications to improve activity and reduce toxicity. In this work, we focus on modifications in the hydrophobic domains, describing analogues that broaden or narrow the spectrum of activity including both Gram-positive and Gram-negative bacteria, with MICs in the low µM range and low hemolytic activity. Using biophysical methods, we explore the interaction of the new molecules with model membranes that mimic the bacterial inner and outer membranes, finding a selective effect on anionic membranes and a mechanism of action based on the alteration of membrane function. Transmission electron microscopy observation confirms that polymyxin analogues kill microbial cells primarily by damaging membrane integrity. Redistribution of the hydrophobicity within the polymyxin molecule seems a plausible approach for the design and development of safer and more selective antibiotics

    Environmental parameters monitoring in the oldest show cave of Italy: Bossea Cave

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    Bossea Cave (Piedmont, Italy) was opened to the pubblic in 1874, making it the first show cave of Italy. This cave develops for about 2800 m in a tectonic contact between carbonate rocks of Middle Triassic, and Permotriassic metavolcanics, and it is crossed for about 1.5 km by a subterranean collector. Three different underground laboratories are present inside the cave to monitor and study several environmental parameters: the Underground Karst Laboratory of Bossea Cave managed by the S.O. Bossea C.A.I. and by the DIATI - Politecnico di Torino, the Karst Hydrogeology Lab, financed by the DIATI – Politecnico di Torino, and the “Giovanni Badino” Climatological Research Centre, funded by PaleoLab of DIATI – Politecnico di Torino and S.O. Bossea C.A.I. The Underground Karst Laboratory of Bossea Cave, together with ARPA Piemonte and ARPA Valle d’Aosta, is mainly concerned with the Radon (222Rn) monitoring. The gas exchange dynamics between water, rock and atmosphere are studied: three Radon monitors for water and two for air tracking were installed in different areas of the cave. The Karst Hydrogeology Lab has 11 data acquisition systems to monitor every 15 minutes water levels, temperature and electrical conductivity of the main subterranean collector and a series of secondary water supplies. The flow rate of the main collector and some secondary inputs are recorded since 1982. The “Giovanni Badino” Climatological Research Centre is aimed at monitoring air, rock and water temperature with extremely precise instruments, calibrated by INRiM. Six main stations are located in touristic and non-touristic cave areas. From June 2021, 52 temperature probes are present in the cavity, acquiring data every 10 minutes. Three atmospheric pressure meters, a pluviograph and two data acquisition systems with four probes for CO2 monitoring are part of the same Lab. Caves are the most important geo-heritage worldwide, however, when cavities are transformed in show caves, an additional impact is produced (e.g. air temperature and CO2 increment, lampenflora growth and pollution). Research allows a greater knowledge of the peculiarities and problems of the system, considering the cave not only a tourist attraction, but an important ecosystem to preserve. Bossea cave is a perfect example of how managers, speleologists and scientists collaboration can exist and bring innovation to natural resources conservation
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