DIAGNÓSTICO COMPARATIVO DE BRUCELOSIS MEDIANTE MÉTODOS SEROLÓGICOS Y MOLECULARES

Brucellosis is an infectious disease that limits livestock development and greatly affects the livestock economy, being considered one of the most important and widely distributed zoonoses worldwide. Early diagnosis of this disease is an essential tool in its control and eradication. The methods recognized by NOM-041-ZOO-1995, such as the card test and complement fixation, present limitations in the diagnosis, compared to the PCR molecular technique. In the present work, a comparative diagnosis of Brucella spp. was performed by PCR amplification of the gene coding for a protein located in the outer membrane (Omp2a) of Brucella spp. and serological tests in blood, milk and cheese samples from goats and cattle. The results showed a higher sensitivity in the detection by PCR technique, while the card test and complement fixation showed inconsistencies due to the occurrence of false positives and negatives. Based on the results, it is suggested to include the PCR technique in the Mexican Official Standard as an objective alternative in the routine diagnosis of brucellosis.

Control de residuos de antibióticos en leche cruda en una empresa lechera en Jalisco México: estudio retrospectivo

The current regulation in Mexico is explicit about the prohibition of the presence of antibiotic residues in raw cow's milk. Due to the impact of the presence of antibiotic residues in milk in the production of dairy products, some dairy companies have implemented their own programs to control antibiotic residues to avoid collection of contaminated material. The aim of this study was to analyze the results of the implementation of a program to control the presence of antibiotic residues in raw cow´s milk collected by a big local dairy industry. During the applications of this program, the frequency of contaminated milk containing the two main groups of antibiotics: β-lactams and tetracyclines, in 9 concentration facilities of a local dairy company, with an average size receiving 800,000- 1,000,000 L/day during 5 years. The antibiotic residue detection was performed using SNAP® Beta-Lactam Test and SNAP® Tetracycline Test simultaneously. During the first year, 222 tanks (2,955,538 L) were tested, of them 93 were positive for antibiotic residues (42.11%). In the fifth year, from 889 tanks containing 5,658,062 L only 13 were positive (1.46%), obtaining a reduction rate of 10.16% annual average. When the companies control the presence of inhibitor residues in the raw milk buy the milk, the farmers discard the contaminated milk; however, they sell it even with antibiotics when the buyers do not carry out controls, so this control measure becomes a solution. The results showed a significant decrease in contamination, being a useful solution to the problem of the appearance of antibiotic residues in milk in the raw material of the plant.

Crecimiento y captura de carbono del árbol majestuoso "Don Cástulo" (Quercus cantanea Née) en el bosque La Primavera en el periodo 2009 - 2021

In the present note, the increase in diameter at breast height (DBH, at 1.30 m height) of the largest oak documented in the forest inventory established in 2009 in the La Primavera Forest (BLP) is reported, calculate the increase in carbon sequestration that this implies and mention the implications for mitigating climate change.

MÉTODO OPTIMIZADO PARA LA EXTRACCIÓN DE DNA DE Sargassum liebmannii

Macroalgae contains high concentrations of polysaccharides, polyphenols and secondary metabolites. Those compounds are factors that prevent the isolation of deoxyribonucleic acid (DNA) and therefore inhibit the polymerase chain reaction (PCR) that is the beginning for the application of any molecular marker. In the present study, the application of six extraction methods was documented; four of them conventional and two commercial kits. The highest efficiency in DNA extraction was obtained with a conventional method with modifications. Said modifications consisted of immersing the algal tissue in ß-mercantoethanol and the addition of the DIECA salt in the extraction buffer. To test the purity of the DNA, in addition to the electrophoresis and spectrophotometry methods, a PCR was performed for the ISSR molecular marker, obtaining amplified fragments using the aforementioned modification.

TRABAJO INTERCENTROS PARA LA DEFINICIÓN DE LA NUEVA ESTRUCTURA CURRICULAR DEL PLAN DE ESTUDIOS DE LA LICENCIATURA EN BIOLOGÍA: UNA VISIÓN POR COMPETENCIAS

This document offers an approach to the collegiate work carried out for the curricular restructuring of the Undergraduate Educational Program for the Bachelor of Biology at the University of Guadalajara. It presents the main elements of analysis and curricular definition that gave structure to the opinion proposal that is currently in force. Finally, it provides some reflections on the challenges involved in collegiate work between curricular committees called “inter-centers”.

Caracterización fitoquímica de Agave shrevei Gentry

The current paper describes and quantifies the presence of total alkaloids, total phenolics, flavonoids and tannins in samples of Agave shrevei leaves, a plant traditionally used to produce distilled beverages in Durango, Chihuahua and Sonora, Mexico, as a part of a project on the integral knowledge of Agave that allows the development of strategies for the use and conservation of these plant resources. Quantifications of alkaloids, total phenolics, flavonoids and tannins were carried out by spectroscopic methods, and the phenolic profile was obtained from HPLC-DAD. The phytochemical information generated revealed the pharmacological and nutritional potential use of A. shrevei.

Evaluación de la composición físico-química y etiquetado nutrimental de leche entera pasteurizada comercial y su cumplimiento con la normatividad oficial mexicana

Currently, there is a wide variety of pasteurized milk brands sold in supermarkets and grocery stores. The objective of this study was to evaluate the physicochemical composition and nutritional information of commercial pasteurized milk commercial and their compliance with the official Mexican standards. In general, all milk brands comply with the commercial information required by the regulations. Likewise, the different pasteurized milk brands showed statistical differences between production batches of the same brand (p < 0.05) and milk brands (p < 0.05) in terms of physicochemical composition. On the other hand, any milk brands did not comply with the protein, fat, and lactose content reported in its labeling (p < 0.05) and the NOM-151-SCFI-2012 stipulations. Additionally, the cluster analysis permits the aggrupation of milk brand quality in four groups. The first group is formed by the A sample, group 2 by the B sample, while, in the third group, the B and C samples, and the fourth group is characterized by the E, F, G, and H samples. In this context, greater vigilance by the corresponding authorities is required to ensure compliance with the parameters established by the official regulations and allow consumers to obtain good quality dairy products.

Farmacocinética y farmacodinamia del dióxido de cloro

Chlorine dioxide (ClO2) is widely used as a drinking water disinfectant in many countries. Due to its antibiotic and antiviral capacity, it has aroused interest as a potential therapeutic agent with respect to the COVID-19 disease, AIDS and Influenza. As a result of this debate in scientific and governmental settings, it was deemed highly timely to provide an up-to-date assessment of the pharmacokinetics and pharmacodynamics of ClO2. The main findings indicate that, due to its high chemical reactivity, ClO2 is rapidly reduced in oral and gastric secretions, producing chlorite (ClO2⁻), which becomes the active agent responsible for its systemic actions. ClO2 also showed potential to act as an oxidant or antioxidant depending on the concentration. Of particular therapeutic interest are the findings that, at low concentrations, ClO2⁻ can protect erythrocytes from oxidative stress while inhibiting excessive production of hypochlorous acid (HClO) mediated by myeloperoxidase (MPO), thus reversing the inflammatory responses and macrophage activation. Finally, taurine-chloramine represents the most relevant functional product formed under the influence of ClO2⁻, said molecule activates the erythroid nuclear factor 2 (Nrf2), (this transcription factor regulates the inducible expression of numerous genes for detoxifying and antioxidant enzymes) , increases the expression of heme-oxygenase (HO-1), protects cells from death caused by hydrogen peroxide (H2O2), improves the expression and activities of antioxidant enzymes, such as superoxide dismutase, catalase and glutathione peroxidase, and contributes to the resolution of the inflammatory process.

Farmacocinética y farmacodinamia del dióxido de cloro

Chlorine dioxide (ClO2) is widely used as a drinking water disinfectant in many countries. Due to its antibiotic and antiviral capacity, it has aroused interest as a potential therapeutic agent with respect to the COVID-19 disease, AIDS and Influenza. As a result of this debate in scientific and governmental settings, it was deemed highly timely to provide an up-to-date assessment of the pharmacokinetics and pharmacodynamics of ClO2. The main findings indicate that, due to its high chemical reactivity, ClO2 is rapidly reduced in oral and gastric secretions, producing chlorite (ClO2⁻), which becomes the active agent responsible for its systemic actions. ClO2 also showed potential to act as an oxidant or antioxidant depending on the concentration. Of particular therapeutic interest are the findings that, at low concentrations, ClO2⁻ can protect erythrocytes from oxidative stress while inhibiting excessive production of hypochlorous acid (HClO) mediated by myeloperoxidase (MPO), thus reversing the inflammatory responses and macrophage activation. Finally, taurine-chloramine represents the most relevant functional product formed under the influence of ClO2⁻, said molecule activates the erythroid nuclear factor 2 (Nrf2), (this transcription factor regulates the inducible expression of numerous genes for detoxifying and antioxidant enzymes) , increases the expression of heme-oxygenase (HO-1), protects cells from death caused by hydrogen peroxide (H2O2), improves the expression and activities of antioxidant enzymes, such as superoxide dismutase, catalase and glutathione peroxidase, and contributes to the resolution of the inflammatory process.

Evaluación de la composición físico-química y etiquetado nutrimental de leche entera pasteurizada comercial y su cumplimiento con la normatividad oficial mexicana

Currently, there is a wide variety of pasteurized milk brands sold in supermarkets and grocery stores. The objective of this study was to evaluate the physicochemical composition and nutritional information of commercial pasteurized milk commercial and their compliance with the official Mexican standards. In general, all milk brands comply with the commercial information required by the regulations. Likewise, the different pasteurized milk brands showed statistical differences between production batches of the same brand (p < 0.05) and milk brands (p < 0.05) in terms of physicochemical composition. On the other hand, any milk brands did not comply with the protein, fat, and lactose content reported in its labeling (p < 0.05) and the NOM-151-SCFI-2012 stipulations. Additionally, the cluster analysis permits the aggrupation of milk brand quality in four groups. The first group is formed by the A sample, group 2 by the B sample, while, in the third group, the B and C samples, and the fourth group is characterized by the E, F, G, and H samples. In this context, greater vigilance by the corresponding authorities is required to ensure compliance with the parameters established by the official regulations and allow consumers to obtain good quality dairy products.