TIP Revista Especializada en Ciencias QuimicoBiologicas最新文献

El benzo[a]pireno (b[a]p), es un hidrocarburo aromático policíclico (PAH) producto de combustiones incompletas de materia orgánica. Es considerado como carcinógeno debido a que los metabolitos derivados de su biotransformación, como el benzo [a] pireno diol epóxido (b[a]pDE), tienen propiedades mutagénicas y carcinogénicas. El b[a]p es metabolizado por las enzimas citocromos P450 1A1 (CYP1A1) y el citocromo P450 1B1 (CYP1B1) cuya expresión es inducida por la vía de señalización del receptor de hidrocarburos de arilo (AhR). Algunos estudios sugieren que el AhR es capaz de modular otros procesos celulares, además de la desintoxicación de xenobióticos como el desarrollo, diferenciación, proliferación, respuesta inmune, promoción del cáncer y apoptosis. Esto mediante la modulación de vías de señalización mediadas por proteínas cinasas como la del receptor del factor de crecimiento epidermal (EGFR, por sus siglas en inglés). Sin embargo, no es clara la función del AhR en estos procesos ni cómo el AhR es capaz de interactuar con otras vías de señalización. Las alteraciones celulares inducidas por b[a]p son complejas y pueden estar mediadas por más de una vía de señalización y la activación de múltiples genes, por lo que es esencial saber qué vías están involucradas en el metabolismo de los PAH para una mejor comprensión de las bases moleculares de enfermedades como el cáncer.

Benzo[a]pyrene (b[a]p), is a polycyclic aromatic hydrocarbon (PAH) product of incomplete combustion of organic matter. B[a]p is considered as a carcinogen due to the mutagenic and carcinogenic properties of its biotransformation derivatives, such as benzo[a]pyrene diol epoxide (b[a]pDE). B[a]p is metabolized by cytochrome P450 enzymes 1A1 (CYP1A1) and 1B1 (CYP1B1), whose expression is regulated by the aryl hydrocarbon receptor (AhR) signaling pathway. Studies suggest that AhR is involved in the regulation of other cellular processes, in addition to detoxification of xenobiotics, such as development, differentiation, proliferation, immune response, cancer development, and apoptosis, by modulating signaling pathways mediated by protein kinases such as the epidermal growth factor (EGFR). However it is not clear the role of AhR in these processes nor the mechanisms of AhR interaction with other signaling pathways. Cellular changes induced by b[a]p are complex and may be mediated by more than one signaling pathway and by the activation of multiple genes, so it is essential to know which pathways are involved in the metabolism of PAHs for a better understanding of the molecular basis of diseases such as cancer.

The microorganisms are capable of accumulating heavy metal ions from water as biosorbent agents, offering a potential alternative for the detoxification and recovery of toxic/precious metals in industrial wastewater. In the present work, metal-resistant bacterial strains were isolated and identified from activated sludge of a waste treatment plant in the Municipality of Santa Rosa Jauregui, Querétaro. To obtain bacteria tolerant to metals, 37 bacterial strains and two isolates were selected based on their ability to show high tolerance (strains C-13 and C-16), maximum adsorption capacity for the studied metals. In this article, the term biosorption is used to encompass uptake by whole (dead) biomass via physicochemical mechanisms such as adsorption or ion exchange. The adsorption capacity was measured with alkaline and acid treatments to determine the conditions for maximum adsorption. The adsorption capacity with acid treatment was lower than biosorbent with alkaline treatment. A second part of the study was the biosorption of heavy metals (Cd, Cr, Mn, and Pb) from aqueous dead biomass of Bacillus sp (strain C13 and C16) isolated from the activated sludge in the first stage.

Los microorganismos tienen capacidad de acumular metales pesados como agentes bioadsorbentes ofreciendo una alternativa para la remoción de metales tóxicos en aguas de efluentes industriales. El objetivo del presente trabajo fue aislar e identificar bacterias tolerantes a los metales pesados (Cd, Cr, Mn y Pb) de lodos activados provenientes de la planta de tratamiento de agua del Municipio de Santa Rosa Jáuregui, Querétaro. Para seleccionar las bacterias que son tolerantes a los metales se aislaron 37 cepas bacterianas de las cuales se seleccionaron la Cepa-13 y Cepa-16 (C-13 y C-16), que presentaron una máxima capacidad de adsorción para los metales estudiados. En este artículo, el término biosorción describe la remoción de contaminantes y la utilización de biomasas (muerta) mediante mecanismos fisicoquímicos como el proceso de adsorción o de intercambio iónico. Para obtener las condiciones de máxima adsorción se aplicó un tratamiento alcalino y uno ácido. La capacidad de adsorción fue menor en medio ácido que el bioadsorbente con tratamiento alcalino. Una segunda etapa del estudio fue la biosorción de metales pesados (Cd, Cr, Mn, y Pb) utilizando las biomasas muertas de Bacillus sp (cepa C13 y C16) aisladas de los lodos activados de la primera etapa.

La epilepsia es un trastorno neurológico que afecta a 50 millones de personas en el mundo. Se define por la presencia de crisis epilépticas espontáneas resultado de descargas sincrónicas de una población neuronal debido a un dinamismo anormal de las redes neuronales. Diferentes factores han sido implicados en su etiopatogenia, uno de ellos siendo los procesos inmunológicos e inflamatorios. En el presente trabajo revisaremos los datos existentes sobre el papel de la inflamación/neuroinflamación en la epilepsia.

Epilepsy is a neurological disorder affecting 50 million people worldwide. It is defined by the presence of spontaneous seizures result of synchronous discharges of neuronal population due to abnormal dynamics of neural networks. Different factors have been implicated in its pathogenesis, one of them being immune and inflammatory processes. In this paper we review the existing data on the role of inflammation / neuroinflammation in epilepsy.

Spermatic DNA contributes one half of the genetic material to offspring. Currently, the parameters obtained through a seminogram do not provide complete information on the potential fertilization of the semen and the ability to produce a healthy embryo and an on-going pregnancy. This is the reason why the interest in developing techniques to assess sperm DNA fragmentation has been increased, as damage during spermatogenesis can occur at any stage of the process, this being a multifactorial phenomenon and not entirely delimited yet. Nowadays the infertility is an increasing global problem, and it has been shown that the quality of the DNA in the sperm can affect fertilization; this is why the evaluation of sperm DNA integrity, in addition to the study of the sperm parameters may provide additional information on the quality of the spermatozoa, resulting in great help to identify the causes of male infertility and thus can be used to better guide couples with infertility issues.

Arbuscular mycorrhizal fungi (AMF) are essential for the functioning of ecosystems, including arid and semiarid. This research evaluated fire effect on AMF species richness associated with Cylindropuntia imbricata, Mimosa biuncifera and Zaluziana augusta. In the Eco Park “Cubitos” in Pachuca, Hidalgo, two xeric shrublands were selected: i) conserved and ii) disturbed by wildfire. At each site and in three individuals of C. imbricata, M. biuncifera, Z. augusta and open areas (OA, no plants), soil samples (1 kg) were collected to determine the taxonomic richness of AMF by genus and specie, as well as soil humidity and pH. These variables were analyzed with a variance, similarity and correspondence analysis. The AMF richness consisted of eleven species grouped in six families. M. biuncifera in the preserved site had the highest richness of AMF to genus (6) and species (6), whereas in the disturbed site was C. imbricata with four genus and six species. Wildfire reduced the AMF species richness 50, 25 and 50% in M. biuncifera, Z. augusta and OA, respectively; while in C. imbricata increased 34%. Gigasporaceae family was only associated with M. biuncifera and Z. augusta in the preserved condition. Correspondence analysis suggests that the identity of the plant specie affects species composition of AMF.

A synthesis of a research series about biological activity and phytochemical composition of 10 plant species used in traditional medicine by the people of Tehuacán-Cuicatlán Valley, Puebla, is presented herein. In this review, results of the biological properties of essential oils, extracts and pure metabolites isolated of medicinal plants are shown. The biological activities studied were: antibacterial, antifungal, antioxidant, photoprotective, hypoglycemic and anti-inflammatory. Results were positive in each of the aspects studied in majority of species. Suggesting that there is a strong phytochemical and pharmacognostic support that endorses the traditional knowledge about the medicinal plants used in that region of México.

High altitude lakes, with a low mineralization, alkalinity and nutrient levels, are sensitive ecosystems to natural or anthropogenic disturbances and currently are in risk due to global warming. There are only two high altitude lakes (> 3,800 m asl) in Mexico, La Luna and El Sol, in the Nevado de Toluca crater. Chemical parameters and surface sediment diatom assemblages show differences between both lakes, La Luna has lower pH and mineralization, and in spite of their geographic proximity, each lake has a characteristic diatom assemblage, with lower diatom concentration and species richness in La Luna. In this lake Encyonema perpusillum and Psammothidium helveticum are dominant while in El Sol are Cavinula pseudoscutiformis, Psammothidium levanderi and Aulacoseira distans. This ecological distribution is the basis for the interpretation of the diatom record from La Luna, from a 57 cm long core dated with ²¹⁰Pb y ¹⁴C for which cladocera and magnetic susceptibility data are also available. These proxies allowed identifying the beginning of a trend towards colder and dryer climates around 1350-1510. This period correlates with the Little Ice Age (LIA) in which the coldest and driest conditions were from 1660 to 1760, during the Maunder solar minimum. Cooler and drier conditions are recoded until the begining of the 20th century. Correlation with other paleoenvironmental records show that there was a regional trend to drier climates during the LIA in central Mexico.

In order to determine if artificially collected water fog in the mountainous located in central the region of Veracruz state is suitable for human consumption; a preliminary sampling was made, from January to March (2010), the period with more fog frequency. The objective was to analyze the physical, chemical and biological aspects concerning water quality. It was found that this water is not suitable for direct human consumption, since it contains heavy metals such as mercury, coliform organisms and high amounts of ammonia nitrogen, though it is suitable for direct use in agriculture. However, it is possible to apply a sanitation treatment for human use at a cost of 0.00341 USD L^-1 not including the labor cost neither the necessary infrastructure. Various causes can lead to this water pollution are discussed and it is concluded that collected fog water is not suitable for human consumption, but it might be used for agriculture.

Nuclear receptors (RNs) are a family of transcription factors activated by ligand which regulate the expression of many genes dependent on the cellular type and context. The subcellular localization of RNs is highly dynamic and affects its function as transcriptional factors. In the presence of its specific ligand, the RNs increase in the nucleus to modulate the expression of their target genes. Thus, the exit from nucleus to cytoplasm of RNs decreases its nuclear accumulation and its transcriptional activity. Therefore, nuclear export is an important mechanism regulating the activity of RNs. Despite its importance, the process of nuclear export of RNs has not been fully studied. However, the studies made so far suggest the involvement of the CRM–1 and Calreticulin (CRT) proteins as mediators of this process. In this review, we highlight the nuclear export as a regulatory mechanism to control the functions of RNs and the structural and functional characteristics of CRM–1 and CRT exportins are discussed.