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Biomedical subjects

M Requena

Publications and source records attributed to M Requena.

11 recordsLinked to original sources
PubMed1984

Influence of basic atrial rhythm on intraatrial conduction of extrastimuli.

Atrial arrhythmias appear to be related to the genesis of intraatrial conduction delays by extrastimuli. To clarify the effects of the basic atrial cycle on intraatrial conduction of extrastimuli, atrial conduction delays and conduction delay zones were measured in 22 patients with and without atrial arrhythmias. Basic cycles were (A) sinus rhythm; (B) paced at the right atrial (RA) appendage with maximum cycle length possible; (C) paced at the RA appendage with cycle length of 600 ms; and (D) paced at the proximal coronary sinus at the same cycle length as B. Extrastimuli were always delivered at the RA appendage. Conduction delays and conduction delay zones were 5- to 7-fold longer when driving stimuli and extrastimuli were delivered through the same electrodes than when the basic cycle was sinus or driven at a distance from the extrastimuli (p less than 0.001). This effect must be considered when groups of patients or the results of interventions are compared.

Atrial Fibrillation↗
PubMed1975

Interstitial fluid pressure in canine gastric mucosa.

Guyton's capsules were implanted in the submucosa of the gastric corpus of dogs. The pressure of the fluid inside the capsule (ICP) was measured between 12 and 42 days later after mounting the piece of the corpus in a Plexiglas chamber. The capsule was always filled with saline. In two out of three experiments, the ICP did not change significantly when the saline was replaced by isotonic glucose or blood plasma. Changes of pressure exerted on the surface of the stomach were accurately monitored by the ICP recordings. Changes of circulation produced by compression of the artery or the vein connected to the piece of mucosa, or by intra-arterial injections of epinephrine, norepinephrine, isoproterenol, or hypertonic mannitol, modified the ICP as predicted by Starling's law of capillary filtration. Spontaneous activity of the gastric muscles or the activity, which followed intra-arterial injections of acetylcholine, prostigmine, or histamine, changed the ICP significantly. Intra-arterial atropine usually decreased the ICP by 3--5 mmHg. The mean value of the ICP in 49 animals was 0.53 +/- 0.34 mmHg (SEM); it was negative in 43% of the experiments.

Acetylcholine↗
PubMedDate not supplied

[Complex family structures: the formation of multiple family households in Spain].

"This article analyses the social factors that promote the formation of complex family structures--with several [nuclear families]...living in the same household, in Spanish society. Although it could be thought that these complex family structures are associated [with] the household structure typical of traditional peasant communities, it is true that they also exist in...modern urban households." Data are primarily taken from the 1990 Active Population Survey. (SUMMARY IN ENG)

Demography↗