Behaviour of Quercus pollen in the air, determination of its sources and transport through the atmosphere of Mexico City and conurbated areas.

Pollen allergies have a remarkable clinical impact all over world. Quercus pollen is the main allergen in many parts of world. Due to the health impacts caused by exposure to oak pollen, the objectives of this study are to characterise the aerobiological behaviour of Quercus pollen and to determine its potential sources as well as their transport through the atmosphere of Mexico City and surrounding areas between January 2012 and June 2015. Airborne Quercus pollen monitoring was carried out simultaneously in five zones of Mexico City. The percentage of Quercus pollen of the total pollen collected from the air showed that the highest concentration was recorded in 2014, followed by 2012. The annual seasonal variation indicated that flowering and pollen emission into the atmosphere began between February and March. The maximum concentration of Quercus pollen was reached at Cuajimalpa. In 2012, the amount of pollen grains was distributed in March and April uniformly, whilst in 2014, the largest amount of pollen was concentrated in March. In 2012 and 2014 (years with the highest pollen concentrations), corresponding intraday variations were quite similar, with a low relative maximum in the morning and the highest concentrations in the evening. The largest values were recorded in 2014, and two processes can explain these. In the afternoon, pollen from secondary forest is carried by southwesterly converging winds, increasing the pollen concentration in Cuajimalpa. In the evening, there is an additional pollen contribution from primary forest via transport by NW winds.

Infección nosocomial en la Unidad Cuidados Intensivos / Nosocomial infection in the Intensive Care Unit

Se realizó un estudio descriptivo longitudinal con el objetivo de describir el comportamiento de la infección nosocomial en pacientes egresados de la Unidad de Cuidados Intensivos del hospital provincial universitario «Carlos Manuel de Céspedes», de Bayamo, desde el 1ro de enero de 1999 hasta el 31 de diciembre del 2000. De 1418 pacientes egresados, 110 (7,7%) cumplieron los criterios de infección nosocomial. Se seleccionaron variables tales como: edad, sexo, factores de riesgos, principales localizaciones, gérmenes frecuentes, tiempo de aparición de la infección y evolución final. En el análisis estadístico se utilizaron medidas de tendencia central y dispersión, así como los intervalos de confianza al 95% para la media. Existió discreto predominio de la infección en el grupo de45 a 59 años, con una media de 51,14 años. La línea venosa central (19,60%), sonda vesical (18,30%) y sonda de levine (13,72%) constituyeron los factores de riesgo principales. Las localizaciones más frecuentes de infección fueron las respiratorias bajas (36,23%) y las urinarias(25,19%). Existió predominio de los gérmenes gramnegativos, entre ellos el enterobacter sp. (35,09%) y la Escherichiacoli (23,07%). La infección apareció entre el segundo y el sexto día (en el 66,3%) y fallecieron el 20,9% delos pacientes que la adquirieron

A longitudinal descriptive study was done with the objective of describing the behaviour of nosocomial infection inpatients discharged from the Intensive Care Unit at «Carlos Manuel de Cespedes» universitary provincial hospital, in Bayamo, from january 1st 1999 to december 31st,2000. From 1418 discharged patients, 110 had criteria of nosocomial infections. Variables such as age, sex, risk factors, principal location, most frequent germs, time of appearance and final evaluation were selected. In the statiscal analysis measures of central tendency and dispersion, as well as intervals of reliance to 95% for the media among others were used. The rate of nosocomial infection was 7, 7 per 100 discharged patients. There was a discreet predominant infection in the 45–59 year-old group whit a media of 51-14 years. The presence of central venous line (19, 60%), vesical catheter (18, 30%)and nasogástrica tube (13, 72%) constituted the main risk factors. The most frequent location of infection were the low respiratory (36, 23%) and the urinaries (25,19%).There was a prevalence of gramnegative germs among them, enterobacter sp (35,09%), escherichiacoli (23,07%) and Proteus sp (21, 15%). The infection appeared between the second and the sixth day in (66, 3%) and20,9% of the patients who adquired the infection died

Design and development of computer-aided chemical systems: virtual labs for teaching chemical experiments in undergraduate and graduate courses.

An environment for the construction of virtual chemistry experiments is presented. This environment is based on the E(V) = M + m model-Experiment (Virtual) = Materials + method-proposed and described herein, which allows the representation and subsequent building of chemistry experiments in virtual 3D worlds to any degree of complexity. The object-based nature of the environment not only allows its use on the Internet but also facilitates integration with other systems, while enabling the system to represent and organize knowledge in such a way that it is available to any teaching environment dealing with chemical laboratory experiments.

[Macroprolactinoma resistant to bromocriptine]. / Macroprolactinoma resistente a bromocriptina.

A 24 year old female with amenorrhea-galactorrhea due to a pituitary macroprolactinoma that eventually responded to bromocriptine with improvement of visual fields and intracranial hypertension syndrome is presented. After 2 years of treatment with bromocriptine her symptoms relapsed and she underwent transphenoidal hypophysectomy. The high serum prolactin levels detected initially decreased under bromocriptine to ward normal levels and was not modified after surgery, while gonadotropin production remain scarce. Growth hormone (GH) serum levels despite its normal concentration decreased significantly (p = less than 0.5) after pituitary ablation. We assume that the lack of response to bromocriptine in this case could have been due to a mixed hormonal nature of the tumor without overproduction or clinical expression of GH activity.