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Biomedical subjects

M Parada

Publications and source records attributed to M Parada.

At least 19 recordsLinked to original sources
PubMed1999

Studies on pharmaceutical ethnobotany in the regions of L'Alt Empordà and Les Guilleries (Catalonia, Iberian Peninsula).

An ethnobotanical survey was carried out in two regions (L'Alt Emporda and Les Guilleries), situated in North East Catalonia (Iberian Peninsula), with an approximate area of 800 km2 and a population of 68000. Through interviews with 73 people, data was obtained on the medicinal uses of 220 species. The most important findings are presented here concerning the ethnopharmacology of those areas. One hundred and ninty four unreported or uncommon uses corresponding to 101 plant species were detected.

Data Collection↗
PubMed1999

Melatonin acts on the nucleus accumbens to increase acetylcholine release and modify the motor activity pattern of rats.

Brain microdialysis coupled to high performance liquid chromatography with electrochemical detection (HPLC-ED) was used to evaluate the influence of melatonin on extracellular concentration of acetylcholine (ACh) in the nucleus accumbens (NAc) of rats. Motor activity was simultaneously monitored during the dialysis sessions with an activity meter. Melatonin and prazosin were administered locally through the dialysis probe. It was found that melatonin dose-dependently increased accumbens ACh. Melatonin (3 microM) decreased horizontal activity and increased vertical activity, while another dose (100 microM) enhanced both horizontal and vertical activity. Prazosin, a putative melatonin antagonist, blocked the effects of melatonin on both motor activity and ACh release when given 20 min before melatonin. Overall, these results suggest that melatonin modulates the release of ACh in the NAc and the pattern of motor activity in the rat.

Acetylcholine↗
PubMed1994

[Follicular and endometrial growth profiles in stimulated cycles with clomiphene citrate].

To study follicular and endometrial growth patterns in Clomiphene Citrate (CC) stimulated cycles, 50 CC cycles of 31 infertile women with patient Fallopian Tubes, were followed, 17 spontaneous conceptional cycles of fertile women were followed as controls. The pattern of follicular growth was similar in both groups until the day before ovulation in which CC cycles showed larger follicular diameters than spontaneous ones; 23.8 +/- 3.1 mm versus 21.6 +/- 2.9 mm (p = 0.013). Follicular rupture occurred on day 16.1 +/- 2.9 in CC cycles, and on day 15.1 +/- 1.85 on spontaneous conceptional ones. This suggests that the follicle, under the influence of CC, has to reach a larger critical mass to produce enough estradiol to revert the hypothalamic blockage produced by the drug, thus permitting the preovulatory LH surge. Endometrium under CC action, was always thinner than in natural cycles. On the day of follicular rupture, the CC cycle's endometrium measured 11.1 +/- 2.02 mm and the natural cycle's endometrium measured 10.6 +/- 1.8 mm (ns). This finding could be attributed to a antiestrogenic effect of CC on the endometrium. It is concluded that cycles under CC action have different follicular and endometrial growth patterns than spontaneous conceptional cycles.

Adult↗
PubMed1993

Flexible intravenous microdialysis probe for blood sampling in freely moving rats.

A flexible intravenous microdialysis probe was constructed from Silastic tubing (0.5 mm ID and 1.0 mm OD), with a cellulose hollow fiber tip 0.2 mm in diameter and 25 mm long with a 6,000 mol wt cut off. In vitro tests showed relative recovery rates of 39.1 +/- 1.9% for epinephrine. In vivo tests in freely moving rats, 36 h and 7 days after surgery, showed stable amounts of epinephrine and glucose. After intraperitoneal injections of 2-deoxy-D-glucose, circulating levels of epinephrine and glucose increased significantly. Similar results were obtained several days after implantation of the probe. We conclude that in situations where prolonged blood sampling is necessary, the flexible microdialysis probe provides a reliable means of accessing circulating levels of neuroactive compounds, nutrients, metabolites, and drugs.

Animals↗
PubMed1993

[Simplified management of an in vitro fertilization program].

The development of in vitro fertilization has accelerated in a dramatic way the understanding on gamete physiology. Results obtained with the technique are easily reproducible and consistent between different centers. It is well known that cumulative pregnancy rates with 5 or 6 cycles can reach up to 60% of couples being pregnant. However, the main limitations to successive attempts have been the cost of the procedure and the surgical transfer of the embryos. In an attempt to overcome this difficulties, efforts has been made to simplify the monitoring of induction of ovulation, use of GnRh analogs and non surgical transfers whenever it is possible. Results presented in 47 of these cycles show non significant differences, with data published elsewhere, on oocyte maturity, fertilization and cleavage rates. Moreover pregnancy rates per aspiration are 28.6% and per transfer 33.3%. We can conclude that ultrasonography alone to monitor ovulation induction as well as uterine transfers do not affect the outcome of the cycle.

Adult↗
PubMed1991

Hypothalamic serotonin in treatments for feeding disorders and depression as studied by brain microdialysis.

Microdialysis was used to measure changes in extracellular serotonin in the hypothalamus of rats while they engaged in feeding behavior or received drug treatments used to treat feeding disorders and affective disorders in humans. Hypothalamic serotonin increased significantly relative to controls in response to (1) intraperitoneal tryptophan after food deprivation, (2) the smell of food and eating a meal, (3) a conditioned taste aversion, (4) d-fenfluramine and fluoxetine, and (5) an amphetamine challenge test after chronic low doses of lithium. In some cases, increases correlated with nonspecific behavioral arousal were seen in the hippocampus. The results suggest that diet, drug, and behavioral therapies, alone or combined, can be used to preferentially modify hypothalamic serotonin in the control of behavioral, emotional, and endocrine problems.

Animals↗
PubMed1989

[Echographic imaging of absence of follicular rupture. Endocrinologic aspects].

Since Jewelewicz in 1975 first described the luteinization of an unruptured follicle (LUF), clinical evidence for the importance of this syndrome has been given by various groups of investigators. Luteal phase of 14 cycles with ultrasound evidence of unruptured follicles were studied with plasmatic determination of levels of FSH, LH, prolactin, 17 B estradiol and progesterone each one day. Two groups were defined. One, with "ovulatory ranges" of progesterone, probably LUF syndrome and another, with "anovulatory levels", probably follicular cysts.

Estradiol↗
PubMed1988

Hypothalamic infusion of amphetamine increases serotonin, dopamine and norepinephrine.

Microinjections of amphetamine into the lateral hypothalamus are known to cause anorexia and hypodipsia. These effects are thought to be mediated by an action of amphetamine on the catecholaminergic terminals to release dopamine and norepinephrine and block reuptake. Direct evidence of neurochemical release was lacking; therefore microdialysis was used to measure monoamines and their metabolites in the extracellular fluid of the lateral hypothalamus while amphetamine diffused out through the microdialysis probe. Amphetamine infusion significantly increased serotonin, dopamine and norepinephrine; it decreased dihydroxyphenylacetic acid (DOPAC), 5-hydroxyindoleacetic acid (5-HIAA), and did not change homovanillic acid (HVA). These results suggest that amphetamine releases dopamine, norepinephrine and serotonin and blocks reuptake which thereby retards neurotransmitter breakdown. The net effect was a quadrupling of extracellular monoamines which could react with postsynaptic receptors. This supports the hypothesis that the behavioral effects of amphetamine injections into the lateral hypothalamus are mediated by dopamine, norepinephrine and suggests, in addition, serotonin.

Amphetamine↗
PubMed1987

Long term administration of some antipsychotic drugs increases body weight and feeding in rats. Are D2 dopamine receptors involved?

Long term administration of the antipsychotic drugs thioridazine, trifluoperazine, haloperidol, and sulpiride increased body weight in rats. This effect was found to be sex dependent, that is, while female rats were prone to gain weight, male rats did not. Chlorpromazine and fluphenazine decreased body weight in male rats but did not affect females. The mechanism of body weight gain was investigated with sulpiride. A linear relationship between dose of sulpiride and body weight gain was found. Also, sulpiride increased caloric intake, and both actions were counteracted by bromocriptine, a specific D2 receptor agonist. These results confirm that antipsychotic drugs affect feeding and body weight and suggest that hyperphagia and body weight gain might be mediated by blockade of dopamine receptors of the D2 type.

Animals↗
PubMed1984

A comparative study of the follicular growth profile in conception and nonconception cycles.

To study the follicular growth profile of normal women, 25 multiparous volunteers were assessed daily by ultrasound to measure the growing follicle and underwent venipuncture daily for detection of the luteinizing hormone (LH) peak. Eleven subjects conceived during the first cycle, 1 during the second cycle, and 1 during the third cycle. The 15 cycles where conception was not achieved showed unequivocal signs of ovulation (i.e., an LH peak and progesterone concentrations in the luteal phase greater than 20 nM/l). The mean prerupture follicular diameter was not significantly different in either group, 19.65 mm and 19.1 mm, respectively; however, the growth profile showed marked differences with a stabilization of follicular growth 24 hours prior to rupture in all patients in the conception group. On the other hand, the LH peak occurred within the 24 hours immediately preceding follicular rupture in the conception cycles; whereas in the nonconception group, this time interval extended up to 48 hours prior to rupture.

Adult↗
PubMed1983

Amphetamine-induced hyperphagia and obesity caused by intraventricular or lateral hypothalamic injections in rats.

Overeating and obesity relative to controls was produced by multiple bilateral injections of 0.5 mg of amphetamine in the lateral ventricles of female rats eating a palatable, high fat diet. This behavioral and physiological rebound following the expected period of anorexia was accompanied by long-term depletion of dopamine in the striatum and of norepinephrine in the hypothalamus. This suggested the next experiment in which 50 micrograms of amphetamine were injected repeatedly in the lateral hypothalamus; again a brief period of anorexia was followed by hyperphagia and chronic obesity. This suggests that amphetamine acts in the lateral hypothalamus not only to suppress feeding, but in high doses it may also have local neurotoxic effects that cause an upward shift in body weight maintained by overeating.

Amphetamine↗
PubMed1979

A peroperative technique for determining the extent of gastrectomy.

An easy, quick and practical way to determine the magnitude of gastric resection during operation consists of determining the length of the lesser and greater curvatures with a Nélaton's catheter. According to the extent of gastrectomy, different denominations should be used. If a precise antrectomy is desired, the physiologic antrum-corpus border should be determined.

Adult↗