Biomedical subjects

Elena López

Publications and source records attributed to Elena López.

6 recordsLinked to original sources

PubMed2005

Implications of physiological studies based on genomic sequences: Streptococcus pneumoniae TIGR4 synthesizes a functional LytC lysozyme.

The Streptococcus pneumoniae LytC lysozyme is responsible for autolysis at 30 degrees C (a temperature close to that of the upper respiratory tract), promotes DNA release in competent cultures, and participates in nasopharyngeal colonization. We show that the virulent pneumococcal TIGR4 strain encodes an active LytC enzyme, in contrast with genome-based predictions.

Base Sequence↗

PubMed2003

Kinetic study of the gas-phase hydrogenation of aromatic and aliphatic organochlorinated compounds using a Pd/Al2O3 catalyst.

The hydrodechlorination of dichloromethane (DCM), tetrachloroethylene (TTCE), chlorobenzene (CBZ) and 1,2-dichlorobenzene (DCBZ), all of them alone and in mixtures, over a commercial Pd/Al(2)O(3) catalyst in a continuous packed-bed reactor was studied in the present work. Results indicate that the reaction kinetics for the single compounds are pseudo-first order kinetics. The reactivity of the compounds studied is very different. So, whereas aromatic compounds and tetrachloroethylene can be fully converted at the operation conditions reported in this work, dichloromethane conversions are lower than 30% in all the cases. The hydrodechlorination of mixtures of organochlorinated compounds shows important inhibition effects, these effects increase as the number of chlorine atoms in the molecule increase. Reaction kinetics for the hydrogenation of mixtures can be represented by a Langmuir-Hinshelwood model.

Aluminum Oxide↗

PubMed2003

Coincidental diagnosis of an occult hilar steroid cell tumor of the ovary and a cortisol-secreting adrenal adenoma in a 49-year-old woman with severe hyperandrogenism.

OBJECTIVE: To report an exceptional association between an occult ovarian steroid cell tumor and a cortisol-secreting adrenal adenoma. DESIGN: Case report. SETTING: Endocrinology and nutrition unit at a general hospital in Spain. PATIENT(S): A 49-year-old woman who presented with persistence of severe hyperandrogenism after removal of a left adrenal adenoma. INTERVENTION(S): An endocrine study evaluating serum androgens, adrenal function, and tumor markers was ordered. Transvaginal sonography was done to rule out an ovarian tumor. Finally, a selective catheterization of ovarian veins allowed the correct diagnosis. MAIN OUTCOME MEASURE(S): Clinical and endocrine description of the patient and preoperative localization of the source of T secretion. RESULT(S): After adrenal surgery, urinary free cortisol levels decreased to normal values, but serum T remained within the tumoral range (3.04 ng/mL). Selective catheterization of ovarian veins revealed a gradient of T concentration in the right ovary. After bilateral annexectomy, a microscopic steroid cell tumor of hilar type was found in the right ovary. Serum T fell within the normal range, and hirsutism progressively improved. CONCLUSION(S): This unusual association between an occult-virilizing ovarian steroid cell tumor and a cortisol-secreting adrenal adenoma illustrates the value of an accurate preoperative workup in women with severe hyperandrogenism.

Adenoma↗

PubMed2002

Gonadal agenesis 46,XX associated with the atypical form of Rokitansky syndrome.

OBJECTIVE: To describe a patient with bilateral ovarian agenesis associated with the atypical form of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome. DESIGN: Case report. SETTING: Unit of Endocrinology, Fundación Hospital Alcorcón. Madrid (Spain). PATIENT: A 17-year-old woman who presented with primary amenorrhea and lack of mammary development. INTERVENTION(S): An endocrine study including pituitary, ovarian, adrenal, and thyroid evaluation was performed. Genetic study was done by karyotype and fluorescence in situ hybridization (FISH) analysis to detect the presence of Y chromosome material. Bone study, intravenous urography, pelvic ultrasound, and laparoscopic study were ordered to evaluate the associated genitourinary and skeletal anomalies. MAIN OUTCOME MEASURE(S): Anatomic, endocrine, and genetic description of the patient. RESULT(S): The gynecologic examination showed a normal vagina ending in a blind pouch. The endocrine evaluation disclosed gonadotropin levels in the menopausal range and nonautoimmune subclinical primary hypothyroidism. The laparoscopic study revealed a single pelvic kidney and an absence of gonads, fallopian tubes, and uterus. The karyotype was 46,XX; no Y chromosome was found in FISH analysis. CONCLUSION(S): To our knowledge, this is the first report of gonadal agenesis 46,XX associated with the atypical form of MRKH syndrome. The primary hypothyroidism may be coincidental.

Abnormalities, Multiple↗

PubMed2002

System for assisted mobility using eye movements based on electrooculography.

This paper describes an eye-control method based on electrooculography (EOG) to develop a system for assisted mobility. One of its most important features is its modularity, making it adaptable to the particular needs of each user according to the type and degree of handicap involved. An eye model based on electroculographic signal is proposed and its validity is studied. Several human-machine interfaces (HMI) based on EOG are commented, focusing our study on guiding and controlling a wheelchair for disabled people, where the control is actually effected by eye movements within the socket. Different techniques and guidance strategies are then shown with comments on the advantages and disadvantages of each one. The system consists of a standard electric wheelchair with an on-board computer, sensors and a graphic user interface run by the computer. On the other hand, this eye-control method can be applied to handle graphical interfaces, where the eye is used as a mouse computer. Results obtained show that this control technique could be useful in multiple applications, such as mobility and communication aid for handicapped persons.

Activities of Daily Living↗

PubMedDate not supplied

[The EMECAS Project: Spanish multicentre study on short-term health effects of air pollution].

UNLABELLED: The EMECAM Project demonstrated the short-term effect of air pollution on the death rate in 14 cities in Spain throughout the 1990-1995 period. The Spanish Multicentre Study on Health Effects of Air Pollution (EMECAS) is broadening these objectives by incorporating more recent data, information on hospital disease admissions and totaling 16 Spanish cities. This is an ecological time series study in which the response variables are the daily deaths and the emergency hospitalizations due to circulatory system diseases and respiratory diseases among the residents in each city. Pollutants analyses: suspended particles, SO2, NO2, CO and O3. Control variables: meteorological, calendar, seasonality and influenza trend and incidence. STATISTICAL ANALYSIS: estimate of the association in each city by means of the construction of generalized additive Poisson regression models and metanalysis for obtaining combined estimators. The EMECAS Project began with the creation of three working groups (Exposure, Epidemiology and Analysis Methodology) which defined the protocol. The average levels of pollutants were below those established under the current regulations for sulfur dioxide, carbon monoxide and ozone. The NO2 and PM10 values were around those established under the regulations (40 mg/m3). This is the first study of the relationship between air pollution and disease rate among one group of Spanish cities. The pollution levels studied are moderate for some pollutants, although for others, especially NO2 and particles, these levels could entail a problem with regard to complying with the regulations in force.

Air Pollution↗