Design, formulation, and optimization of media.

The fundamental knowledge available about the microorganism, substrates, and process represent the basis on which a rational approach for the design and formulation of media for microbial processes can be attempted. In this respect, it is necessary to analyze critically the main objective to be optimized (yield, productivity, quality of final product, etc.). The first step of medium development is concerned with the decision to be taken about the adequate components to be used, followed by the calculation of their concentrations. After medium preparation and experimentation, the application of the most appropriate statistical optimization methodology will make it possible to attain the optimal medium. Medium design and formulation for plant cell processes are still carried out on an empirical basis owing to the lack of fundamental knowledge. However, some general guidelines can be given for growth and production media considering the experimental evidence available about the functions and influence of the medium components for promoting growth and product formation. Adequate manipulation of the carbon, nitrogen, and phosphorus sources and phytohormones and the inclusion of precursors and elicitors in the medium represent the best strategy for improving medium development for plant cell processes. The development of cost-effective medium supplies for mammalian cell culture production of proteins is a key element for a commercially successful process. Medium development is a task that requires experience, time, and resources in its solutions, which may be several. An optimal formulation is elusive because there will always be room for improvement, but through systematic, comprehensive work, practical combinations of nutrients, factors, and feeding schedules can be developed in a reasonable time. A properly developed formulation can bring the burden of the medium below 10% of the total cost of a mammalian cell process.

[Leukocyte migration inhibitory factor and basophil degranulation in drug reactions]. / Factor inhibidor de la migración de leucocitos y degranulación de basófilos en las reacciones a medicamentos.

We performed a prospective study in patients with a medical history of adverse reaction to drugs with the purpose of rule out allergy. We included 31 patients who were attended in the Allergy Service. We compared the sensibility and specificity of the test of inhibition factor of leucocytes migration and degranulation basophil against the exposition. After the statistical analysis, we concluded: the laboratory test, we have already mentioned, have little sensibility and specificity so the exposition test in the quickest, useful, and more simple method to determine drugs allergy, but more dangerous.

[Cardiac tamponade due to pericardial metastasis (author's transl)]. / Taponamiento cardíaco por metastsis pericárdica.

A case of pericardial tamponade secondary to pericardial metastases of bronchogenic carcinoma in a young male is presented. The diagnostic studies are reviewed, specially the cytologic study of pericardial fluid. The fact that malignant tumors of the lung are the more frequent invaders to the heart is emphasized, with different clinical presentations regarding the involved site. The lymphatic pathways of the heart are reviewed, explaining the formation of hemorrhagic fluid inside the pericardial sac. Although this type of pathology is relatively rare as a cause of pericardial tamponade, this possibility should be kept in mind in order to make an early diagnosis.

Properties of a bacteriocin produced by Clostridium bifermentans 18137.

Una particula filamentosa, con um amplio espectro de actividad similar a una bacteriocina, producida por Clostridium bifermentans 18137 fue caracterizada parcialmente. La bacteriocina inhibio el crecimiento de Clostridium aerofoetidum y causo lisis de celulas viables, pero no de celulas previamente muertas por exposicion al aire. La particula fue precipitada por sulfato de amonio a 40% de saturacion, tuvo una densidad entre l,22 y 1,29 g/ml y consistio en filamentos helicoidales. Fue inactivada por pronasa, quimotripsina y calentamiento a 95o.C por 5 min. R Nasa, Ba++ y Cd++ inhibieron las lisis cuando se anadieron junto con la bacteriocina, pero se mantuvo la actividad inhibitoria bajo las mismas condiciones. Se encontro RNA asociado con la bacteriocina y fue removido solo parcialmente por tratamiento con R Nasa. Celulas de C. aerofoetidum tratadas con la bacteriocina sufreiron dano extenso que incluyo destruccion de la membrana citoplasmatica y la pared celular, y disolucion del contenido celular. Tambien se observo la formacion de esferoplastos y fantasmas bacterianos

Taponamiento cardiaco por metastasis pericardica. / Cardiac tamponade due to pericardial metastasis

Se presenta el caso de un paciente masculino joven, con diagnostico de taponamiento cardiaco consecutivo a metastasis pericardicas de adenocarcinoma broncogeno. Se revisan los metodos diagnosticos mas utiles, entre los cuales destaca la citologia del derrame periocardico. Se enfatiza el hecho de que los tumores malignos originarios del pulmon, son los que mas frecuentemente invaden corazon, con diferente expresion clinica segun el sitio involucrado. Se hace una exposicion detallada de las vias de drenaje linfatico, mismas que explican adecuadamente el desarrollo de liquido hemorragico dentro del saco pericardico y se comprueba que este tipo de patologia, es una causa relativamente rara de taponamiento cardiaco, pero que debe tenerse en mente para un diagnostico precoz que puede ser valiosa ayuda

Production of Lactase by Candida pseudotropicalis Grown in Whey.

Lactase (beta-d-galactosidase) was produced by Candida pseudotropicalis grown in deproteinized whey. Maximum enzyme production in 2% whey was obtained by supplementation with 0.15% yeast extract, 0.1% (NH(4))(2)SO(4), and 0.05% KH(2)PO(4) (wt/vol). Highest enzyme values (4.35 U/mg of cells and 68 U/ml) were obtained with 10 to 12% whey, while enzyme yield was maximal in 2% whey (0.87 U/mg of whey). Optimal initial pH for cultivation was 3.5. The best conditions for extraction included 2% (wt/vol) chloroform, 10 h of treatment, pH 6.6 and higher, and 30 to 37 degrees C. Optimum pH and temperature for enzyme activity were 6.2 and 47 degrees C. The enzyme had a K(m) for O-nitrophenyl-beta-d-galactopyranoside of 3.06 x 10 M and the initial V(max) was estimated as 6.63 x 10 M per min. It hydrolized 50 and 100% of the lactose in whey and milk within 4 and 5 h, respectively, at 37 degrees C. The lyophilized enzyme retained 95% of activity for 3 months when stored at -20 degrees C.