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P Durán

Publications and source records attributed to P Durán.

13 recordsLinked to original sources
PubMed2005

Prenatal protein malnutrition induces a phase shift advance of the spontaneous locomotor rhythm and alters the rest/activity ratio in adult rats.

Evidence is accumulating for significant structural and functional changes within the central nervous system (CNS) following prenatal protein malnutrition. Included among the structures that are likely to be affected are the suprachiasmatic nuclei (SCN) involved in the regulation of locomotor activity, sleep-wake cycle, and drinking behavior. To determine the effects of prenatal protein malnutrition on the spontaneous activity rhythm, 24 h radiotelemetric measurements were recorded over an 8-day period. Male offspring of rats provided with protein-deficient (6% casein) or adequate (25% casein) diets for 5 weeks prior to mating and throughout pregnancy were studied. Well nourished rats displayed a rise in activity level during the first hour of the 12h light phase, whereas prenatally malnourished rats displayed this increase during the 12h dark phase, approximately 50 min before lights on, reflecting a significant phase advance in this group. In addition, cosinor analysis revealed that the alpha/rho relationship was affected in the previously malnourished group, the activity phase being shorter than in the well-nourished animals. These findings suggest changes in the regulatory systems controlling the locomotor activity rhythm as a consequence of prenatal protein malnutrition. Alterations in entrainment to the light-dark cycle, and/or in the coupling force of the circadian oscillators are all candidate mechanisms.

Animals↗
PubMed2002

Pre- and post-natal protein malnutrition alters the effect of rapid eye movements sleep-deprivation by the platform-technique upon the electrocorticogram of the circadian sleep-wake cycle and its frequency bands in the rat.

Selective deprivation of paradoxical (or rapid eye movements) sleep (REMS) in protein malnourished young male rats, results in circadian and homeostatic alterations. By means of electrocorticographic recordings, we have examined the sleep-wake cycle as a functional maturity index, and its circadian and homeostatic mechanisms in prenatal (PM) and chronically (CM) protein malnourished young male rats. The effects of rapid eye movements sleep-deprivation (REMS-D), by the platform technique in a "conflict experiment" (i.e. recovery from REMS-D begun during the circadian phase of activity), revealed that in PM animals, wake (WAK) was increased significantly during recovery days 1 and 2 (RD1, RD2); and slow wave sleep (SWS) was reduced significantly during these days. Prenatal protein-malnutrition altered the phase of WAK and REMS rhythms, and the amplitude of SWS rhythm was decreased. The REMS compensatory increase after REMS-D (REMS rebound) was confined to the first 4-h block of the activity phase in all experimental groups and 24 h later another REMS rebound was displayed in PM animals. The paradoxical sleep-rebound in CM animals was significantly higher than control and PM rats and it was only shown at the first 4-h block after REMS-D. Before and after REMS-D the circadian distribution of both sleep states, and the electrocortical frequency bands showed different circadian phases at the same day-time in control, PM and CM rats. The aforementioned indicates that protein malnutrition exerts important effects on the circadian and homeostatic mechanisms driving sleep. Therefore, the temporal structure of the malnourished rats may not allow proper synchronization of some sleep parameters, particularly REMS, to the environmental time cues.

Animals↗
PubMed1997

Effects of acute prenatal ethanol exposure on Bergmann glia cells early postnatal development.

The effects of acute ethanol exposure during the prenatal phase of Bergmann glia cell (Bgc) generation were evaluated in three postnatal days. Ethanol exposed rats showed Bgc with reduced soma size, decreased number and width of their fibers, and increased fiber length, when compared with control animals. These differences, however, were significant at postnatal day 12. Our results demonstrate that acute, prenatal exposure to ethanol during critical stages of brain development disrupts Bgc early postnatal development.

Animals↗
PubMed1997

Effects of prenatal protein malnutrition on mossy fibers of the hippocampal formation in rats of four age groups.

The present study was undertaken to investigate the effect of prenatal protein deprivation on the postnatal development of the mossy fiber plexus of the hippocampal formation on postnatal (P) days 15, 30, 90, and 220. Although there is extensive information about the effects of malnutrition on cell body and dendrite morphology, little attention has been paid to axons or axon plexuses. The mossy fiber plexus represents the dentate gyrus granule cell axonal projection to areas CA4 and CA3 of the hippocampal formation and is readily demonstrated with Timm's heavy metal stain. With the use of this stain, the plexus was measured at 13 levels throughout the hippocampal complex. There was no effect of the diet on the anatomical distribution of the plexus. The current study, however, does show significant effects of prenatal protein malnutrition on postnatal development of the mossy fiber plexus that are age dependent. The prenatally malnourished rats show significant deficits in the total rostro-caudal extent and volume of the plexus on P15, P90, and P220, with the most marked dietary effect on P220. There was no significant diet effect on P30 in either extent or volume.

Analysis of Variance↗
PubMed1997

Effects of prenatal protein malnutrition on hippocampal CA1 pyramidal cells in rats of four age groups.

The present study was undertaken to investigate the effect of prenatal protein deprivation on area CA1 hippocampal pyramidal cells on postnatal (P) days 15, 30, 90 and 220 using Golgi techniques. Age related changes in both groups and diet related changes between groups were assessed. There were significant diet effects at all four ages, with one of 12 different measurements showing a significant diet effect on P15, five on P30, one on P90, and seven on P220. The most marked effect of the diet was on pyramidal cell dendrite spine density in the stratum moleculare and stratum radiatum, with a different pattern of diet effects in the two strata. In pyramidal cell dendrites in the stratum moleculare, there was a deficit in spine density that was significant at three of the four ages and there were similar age-related changes in the two diet groups. Spines on pyramidal cell dendrites in the stratum radiatum showed a lack of synchrony of age-related changes in the two diet groups, with an increased spine density in the malnourished rats on P30 and a widening deficit in this parameter on P90 and P220. The bimodal distribution to these changes, with most marked deficits occurring on P30 and P220, with an intervening period of apparent "catch-up" on P90, is of interest and may be a significant brain adaptation to malnutrition. The present study is the final of three morphometric studies on the effect of prenatal protein restriction on three key neurons in the hippocampal trisynaptic circuit. When compared to our previous studies on the dentate granule cell and the CA3 pyramidal cell, it is noted that there is an effect of the low protein diet on all these neurons, with the most marked effect on the predominantly postnatally generated dentate granule cells.

Analysis of Variance↗
PubMed1997

Preventing iron deficiency in infants and preschool children in Argentina.

This paper summarizes the results of most major studies of iron deficiency and anemia in infants and children in Argentina. Possible reasons for high prevalences of iron deficiency and anemia in certain population groups are given, and plans for future interventions, based on these data, are discussed.

Adolescent↗
PubMed1984

[Importance of the tissue polypeptide antigen level in neoplastic patients. Its correlation with other tumor markers].

In order to know the behavior of the tissue polypeptide antigen (TPA) as a tumor marker, the authors determine its amount in serum by means of radioimmunoassay (TPA Prolifigen RIA) in 441 patients having respiratory, digestive, urogenital, hematopoietic, mammary and other malignant tumors. The obtained results indicate that: TPA has no tumor specificity; however it increases in tumors without any other known tumor marker. TPA has no diagnostic value, but it is useful for the following up of digestive, mammary, respiratory, ovarian and testicular cancer; amounts of TPA comprised between 90 and 120 U/l are not specific and have no clinical significance; and it is very useful the simultaneous determination of CEA and TPA in the respiratory, digestive and mammary malignant neoplasms to help the clinical data in the evaluation of tumor mass (CEA) and tumor activity (TPA) without indication of tumor localization.

Adult↗
PubMedDate not supplied

[Intravenous streptokinase in acute myocardial infarction. A Mexican multicentric study].

To evaluate the benefits of intravenous streptokinase (SQIV) in acute myocardial infarction (AMI), we joined a group of ten Mexican university hospitals, that were coordinated by the National Institute of Cardiology of Mexico. We included patients less than 70 years of age admitted to the hospital with less than 6 hours from the onset of chest pain during their first myocardial infarction. All patients had ST segment elevation of 1.5 mm or more, and none had contraindication for SQIV. They received 1.5 millions of SQIV in one hour. Reperfusion criteria included absence of pain, ST segment reduction and a rapid rise and fall of enzyme levels. Angiographic criterion for reperfusion was the permeability of the affected coronary vessel. Of 66 patients studied, 57 (86%) had clinical reperfusion; of the 24 available angiographic studies, 92% demonstrated reperfusion. Eight (12%) of the patients had minor complications and 7 (10%) had serious complications. There were 0 deaths. We concluded that SQIV is a useful therapeutic procedure, easy to perform in general hospitals.

Adult↗