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Biomedical subjects

J Sáiz

Publications and source records attributed to J Sáiz.

16 recordsLinked to original sources
PubMed2000

A study of temperament and personality in anorexia and bulimia nervosa.

Although temperament and personality traits could influence the development and course of eating disorders, only a few studies examined the similarities and differences in personality between anorexia and bulimia nervosa. We compared 72 patients with DSM-IV eating disorders and 30 healthy controls. Dimensions of personality and personality disorders were evaluated with the Eysenck's EPQ, Cloninger's TCI, and the SCID-II questionnaires. The rates of impulsivity and clinical features were evaluated using specific rating scales. A comorbid personality disorder was found in 61.8% of patients with eating disorder. Avoidant personality disorder appeared was relatively common in anorexia nervosa restricting type; borderline personality disorder was most frequent in bulimia nervosa and the binge eating-purging type of anorexia nervosa. From a dimensional perspective, anorexic patients presented high scores in the dimension of persistence. Higher harm avoidance and impulsivity was found in bulimic patients. The overall eating disorders group presented high scores in neuroticism and low scores in self-directedness. Eating disorder patients have heterogeneous features of temperament and personality traits. Cluster C personality disorders seem more common in anorexia nervosa restricting type and impulsive personality features are associated with bulimic symptoms. Impulsivity seems to be a key aspect of temperament of bulimic patients, whereas anorexic symptoms are linked to persistent temperament traits.

Adult↗
PubMed1996

Simulation of action potentials from metabolically impaired cardiac myocytes. Role of ATP-sensitive K+ current.

The role of the ATP-sensitive K+ current (IK-ATP) and its contribution to electrophysiological changes that occur during metabolic impairment in cardiac ventricular myocytes is still being discussed. The aim of this work was to quantitatively study this issue by using computer modeling. A model of IK-ATP is formulated and incorporated into the Luo-Rudy ionic model of the ventricular action potential. Action potentials under different degrees of activation of IK-ATP are simulated. Our results show that in normal ionic concentrations, only approximately 0.6% of the KATP channels, when open, should account for a 50% reduction in action potential duration. However, increased levels of intracellular Mg2+ counteract this shortening. Under conditions of high [K+]0, such as those found in early ischemia, the activation of only approximately 0.4% of the KATP channels could account for a 50% reduction in action potential duration. Thus, our results suggest that opening of IK-ATP channels should play a significant role in action potential shortening during hypoxic/ischemic episodes, with the fraction of open channels involved being very low ( < 1%). However, the results of the model suggest that activation of IK-ATP alone does not quantitatively account for the observed K+ efflux in metabolically impaired cardiac myocytes. Mechanisms other than KATP channel activation should be responsible for a significant part of the K+ efflux measured in hypoxic/ischemic situations.

Action Potentials↗
PubMed1994

Hormonal, renal, and metabolic alterations during hypertension induced by chronic inhibition of NO in rats.

The evolution of renal excretory function and circulating vasoactive systems was studied during progressive increases in blood pressure (BP) induced in rats by oral administration of NG-nitro-L-arginine methyl ester (L-NAME; 5-30 mg/100 ml) for 5 wk. L-NAME induced a stepped elevation (P < 0.05) in BP levels without changing creatinine clearance, urine flow, or sodium excretion rate along the study. Reductions (P < 0.05) in plasma renin activity and plasma aldosterone concentration were found only during treatment with 30 mg/100 ml of L-NAME. Plasma norepinephrine and epinephrine concentrations were elevated (P < 0.05) in the last week of the study. Plasma concentrations of endothelin-1 and urinary excretion of prostaglandin E2, 6-ketoprostaglandin F1 alpha, and thromboxane B2 were not significantly affected by L-NAME. Similarly, no changes in plasma concentrations of glucose, insulin, total cholesterol, or triglycerides were observed. In summary, during long-term administration of L-NAME, progressive increases in BP levels were observed without changes in either sodium excretion or enhanced circulating vasoconstrictor activity. Thus, it is likely that inhibition of synthesis of nitric oxide (NO) in the vasculature leads to an imbalance between the tonic relaxing action of NO and the influences of vasoconstrictor agents even when the latter remain at normal levels.

Aldosterone↗
PubMed1992

Platelet alpha 2-adrenoceptor density in pregnancy-induced hypertensive patients: effect of epidural analgesia.

OBJECTIVES: Although pregnancy induced hypertension (PIH) is an important and relatively common medical problem, its pathophysiology remains unresolved and the search for a biochemical marker that precedes the hemodynamic abnormalities of PIH continues. Since human platelets contain alpha 2-adrenoceptors, these receptors were measured in women with PIH to determine whether patients with PIH have alpha 2-adrenoceptor abnormalities that might cause or exacerbate the hypertensive process. The effect of epidural analgesia upon blood pressure and its relation to changes in platelet alpha 2-adrenoceptor density were also investigated. DESIGN: Biochemical measurements and radioligand binding assays in platelets were performed on 33 patients with the criteria for PIH and on 26 healthy pregnant women. RESULTS: Blood pressure was significantly elevated in hypertensive women when compared with normotensive pregnant women although, in this group, blood pressure returned to normal levels in response to epidural analgesia. In drug-free hypertensive patients, the specific binding of 3H-yohimbine to platelet membranes increased significantly compared with that in control pregnant subjects. In contrast, the dissociation constant was not significantly different in the two groups. Furthermore, alpha 2-adrenoceptor density in the group with PIH returned to normal levels in response to epidural analgesia. CONCLUSION: Our findings indicate that PIH is characterized by an exaggerated response of platelet alpha 2-adrenoceptor density to a rise in blood pressure and that this alteration could be significant in the pathogenesis of hypertension. Furthermore, human alpha 2-adrenoceptors undergo regulatory mechanisms similar to those recently described for adrenergic receptors in a variety of animal models.

Adult↗
PubMed1990

Altered renal alpha-adrenoceptor density induced by prolonged NaCl and DOCA administration in spontaneously hypertensive rats.

This study examines the effects of a 6-week exposure to 1% NaCl in tap water with and without desoxycorticosterone acetate (DOCA) on renal alpha adrenoceptors and systolic blood pressure (SBP) in spontaneously hypertensive adult rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. On normal sodium intake, SHR had higher renal alpha 1- (p less than 0.05) and alpha 2-adrenoceptor densities (p less than 0.001) and SBP (p less than 0.001) than WKY rats. Although WKY rats given either 1% NaCl, DOCA, or DOCA plus 1% NaCl developed hypertension after 6 weeks of treatment, only 1% NaCl administration for the same period produced an increase in the alpha 1-adrenoceptor density when compared to the control (p less than 0.001). In SHR, ingestion of 1% NaCl or DOCA plus 1% NaCl increased the already elevated alpha 2-adrenoceptor density (p less than 0.001) and SBP even more in this strain after 6 weeks of treatment. Equilibrium dissociation constants (Kd), however, were similar for both classes of receptors in experimental and control rats. The results of this study indicate that only the combination of 1% NaCl in tap water and DOCA administration is effective in accelerating hypertension in adult SHR. On the other hand, in this form of genetic rat hypertension, exaggerated sodium intake with or without DOCA administration could presumably be correlated with the increased renal alpha 2 adrenoceptors observed in these animals.

Animals↗
PubMed1989

Renal alpha-adrenoceptor density and blood pressure in SHR rats exposed chronically to prazosin and/or yohimbine.

In the present study we evaluated the effect of selective alpha 1 and alpha 2-adrenoceptors blockade on the development of hypertension and on renal alpha-adrenoceptor densities in the spontaneously hypertensive rats (SHR). In these rats, daily intraperitoneal administration of 0.1 mg/kg of prazosin, yohimbine or prazosin + yohimbine for seven weeks significantly retarded the development of hypertension. In an attempt to characterize the relationship between changes in blood pressure and the renal alpha-adrenoceptor number after a prolonged alpha-blockade in the SHR, we have used 3H-prazosin and 3H-yohimbine as the selective ligands for alpha 1 and alpha 2-adrenoceptors. Saturation studies showed that renal alpha 1 and alpha 2-receptor densities were significantly decreased by prazosin and yohimbine, respectively, in SHR. Equilibrium dissociation constants (KD), however, were similar for both classes of receptors in experimental and control rats. In WKY rats, to the contrary, only prolonged administration of yohimbine and prazosin + yohimbine for seven weeks decreased the number of 3H-binding sites, and this decrease consisted in a Bmax change rather than an affinity (KD) change. Thus, the study provides evidence that the elevated blood pressure in the SHR is related, at least in part, to an abnormality in the adrenergic system control.

Animals↗
PubMed1987

Hypertensinogenic factors and renal alpha-adrenoceptors in young SHR and WKY rats.

The effects of high sodium intake (drinking 1% NaCl), DOCA and DOCA + 1%NaCl for 6 weeks on renal alpha 1- and alpha 2-adrenoceptors and on systolic blood pressure (SBP) were examined in young spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). On normal sodium intake, SHR rats had higher renal alpha 1 (p less than .001) and alpha 2-adrenoceptor densities (p less than .001) and SBP (p less than .001) than WKY rats. Although, WKY rats given either 1% NaCl, DOCA, and DOCA + 1% NaCl developed hypertension after 6 weeks of treatment, only 1% NaCl administration for the same period produced an increase in the alpha 1- and alpha 2-adrenoceptor densities when compared to the control (p less than .01 and p less than .001, respectively). In the SHR rats, to the contrary, ingestion of 1% NaCl and DOCA + 1% NaCl increased the already elevated alpha 2-adrenoceptor density (p less than .001) and SBP even more in this strain after 6 weeks of treatment. Equilibrium dissociation constants (KD), however, were similar for both classes of receptors in experimental and control rats. This study indicates that postweaning exposure of the WKY and SHR rats to a high salt treatment and DOCA can influence the renal alpha-adrenoceptor densities. Although the functional significance of the changes is unclear, it is reasonable to speculate that postweaning exposure to a hypertensinogenic stimuli such as a 1% NaCl and/or DOCA may ultimately interfere with the functional development of the kidney differently in rats genetically predisposed to hypertension (SHR) from normotensive (WKY) rats.

Animals↗
PubMed1987

[Chronic effect of prazosin and yohimbine on the renal epinephrine content of DOCA-sodium and SHR-hypertensive rats].

The chronic effect of two alpha-adrenergic receptor blockers, prazosin and yohimbine, on the renal noradrenaline (NA) content was investigated in two models of hypertensive rats, the DOCA-salt and the spontaneously hypertensive rats (SHR). In DOCA-salt rats an inversal relation exists between the level of blood pressure and renal NA content in all groups studied, except those treated with yohimbine and prazosin plus yohimbine. In SHR rats a decreased renal NA content has been detected with respect to their normotensive Wistar-Kyoto (WKY) rat controls. The administration of prazosin and/or yohimbine did not alter the renal NA content of the SHR rats, while on the contrary these agents produced an elevation of these levels in kidneys from normotensive WKY rats. These results suggest that the alpha-selective blocker agents used, demonstrate a different effect on the renal NA content in the two models of hypertension studied.

Adrenergic alpha-Antagonists↗
PubMed1986

Ontogeny of renal alpha-1 and alpha-2 adrenoceptors in the spontaneously hypertensive rat.

Renal alpha-1 and alpha-2 adrenoceptors were characterized during the development of the spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto rats through Scatchard analysis of [3H]prazosin and [3H]yohimbine binding to kidney membrane preparations in an attempt to correlate biochemical changes with the reported functional changes occurring in hypertension development in the SHR. Renal alpha-1 and alpha-2 receptor density was higher in SHR than in Wistar-Kyoto rats at all ages tested. In contrast to Wistar-Kyoto rats, in which the number of alpha-1 and alpha-2 receptors remained relatively constant with age, the number of renal alpha-1 adrenoceptors in the SHR was lowest at the 4th week of age (61 fmol/mg) increasing transiently at 5 weeks and then again at 8 week reaching a plateau at that time. The maximum number of binding sites for [3H]yohimbine binding in the SHR was also age dependent. The number of renal alpha-2 adrenoceptors in the SHR was lowest at 4 weeks of age (125 fmol/mg) increasing to 220 fmol/mg at 5 weeks of age and to 260 fmol/mg at 8 weeks of age. Adult levels (308 fmol/mg) were reached by 18 weeks of age. Unlike receptor densities, affinity constants were not significantly altered during postnatal development. The changes in alpha-1 and alpha-2 adrenoceptors in the kidneys of SHR may suggest an important developmental role which is not yet understood.

Age Factors↗
PubMed1985

Effect of prazosin and yohimbine on systolic blood pressure and on renal norepinephrine content in DOCA-salt rats.

We studied the effect of alpha-1 and alpha-2 blockers (prazosin and yohimbine) on systolic blood pressure (SBP) and on renal norepinephrine (NE) content in Sprague-Dawley normotensive and DOCA-salt rats. The administration of desoxycorticosterone acetate (DOCA) to these rats for 6 weeks increased their SBP from 137 to 183 mmHg (p less than .001). This increase was prevented by simultaneous administration of prazosin (p less than .001), yohimbine (p less than .01), or prazosin + yohimbine (p less than .001). DOCA rats on saline and on yohimbine had lower renal NE content (p less than .05 and p less than .001, respectively) than normotensive rats. Renal NE content of DOCA rats on yohimbine decreased with respect to those treated with prazosin (p less than .001) or prazosin + yohimbine (p less than .05). Besides, renal NE content of DOCA rats on prazosin increased when compared to control DOCA rats (p less than .05). However, these drugs showed no effect on SBP and on renal NE content in normotensive rats. These findings further confirm that the alpha adrenoceptor blockade can prevent the hypertension of DOCA-salt rats in such a way that their blood pressure stabilizes at similar levels to those observed in normotensive treated animals.

Animals↗
PubMedDate not supplied

[Sociodemographic features of suicide attempts].

Suicide accounts for about 10% of deaths among psychiatric patients, and life-threatening attempts are much more common than fatalities. Despite progress in defining risk rates and predictive factors, knowledge on which to base sound clinical and public policies regarding suicide prevention and treatment remains remarkably limited. Social risk factors and psychiatry diagnoses are the main arguments to management the suicidal behaviour in emergency room. Female gender is associate with suicide attempts while male gander is associate with completed suicide. Risk of suicide is increased in young and elderly people. Age is a confounding factor in the relationship among suicide and widow, income and professional status. Emigration and anomie are related with suicide. Social factor, as a marker of suicidal behaviour, are a promising research question.

Adolescent↗
PubMedDate not supplied

[The clomipramine test and subtypes of depression].

OBJECTIVE: Neuroendocrine challenge paradigms have been used to assess serotonergic system in depression but limitations in the specificity of many of these tests have been noted. In this study, the neuroendocrine responses to acute intravenous administration of the serotonin (5-HT) reuptake inhibitor clomipramine were assessed in patients with Major Depression with Melancholia (DMM) and matched subjects with Major Depression (DM) (without Melancholia) and Dysthimic disorder (TD). METHOD: 10 patients who met DSM III-R criteria of DMM, 10 patients with DM and 10 with DD matched for age and sex received 12.5 mg of intravenously administered clomipramine. Prl, Cortisol and GH were measured during the next 135 minutes. RESULTS: The DMM patients had significant blunting prolactin responses to clomipramine compared with the other patients. CONCLUSIONS: These data support the hypothesis that DMM patients have abnormal neuroendocrine responses to the intravenous administration of the 5-HT reuptake inhibitor clomipramine and that they are different from the DM and TD patients.

Adult↗
PubMedDate not supplied

[Serotonergic function in endogeneity of depression].

OBJECTIVE: This study employed an alternative method for assessing serotonergic function in depression. The neuroendocrine responses to acute intravenous administration of the serotonin (5-HT) reuptake inhibitor clomipramine were assessed in patients with Major Depression with Melancholia (DMM) and matched subjects with Major Depression (DM) (without Melancholia) and Dysthimic disorder (TD). METHOD: 10 patients who met DSM III-R criteria of DMM, 10 patients with DM and 10 with DD matched for age and sex received 12.5 mg of intravenously administered clomipramine. Prl, Cortisol and GH were measured during the next 135 minutes. We divided the samples using the Newcastle Scale. RESULTS: The DMM patients had significant blunting prolactin responses to clomipramine compared with the other patients. Most of the major depression patients without melancholia were neurotic depressions according to the Newcastle Scale. There was a negative correlation between endogeneity and prolactin response. CONCLUSIONS: These data support the hypothesis that DMM patients have abnormal neuroendocrine responses to the intravenous administration of the 5-HT reuptake inhibitor clomipramine, and that there is an association between endogeneity and prolactin response.

Adult↗
PubMedDate not supplied

[Sertraline in the treatment of mixed anxiety and depression disorder].

INTRODUCTION: Mixed anxiety and depression disorder (MAD) has been recognized in ICD-10 as a diagnostic group including those anxious and depressed patients who do not fit criteria for any major axis 1 disorders. Mad is usually treated with a combination on AD and BZD although recent reports suggest that SSRI might have both anxiolytic and AD intrinsic properties. METHODS: 36 patients diagnosed of MAD (ICD-10 criteria) underwent treatment with a flexible dose of sertraline for 8 weeks. No BDZ werre allowed during the trial. Efficacy was tested with the Clinical Global Improvement Scale and with changes in Hamilton Depression and Anxiety Scales. Personality scales, including the Cloninger's TCI and the Eysenck's EPQ were used to test the predictive value of personality traits in treatment. RESULTS: Anxiety was reduced in 55% and depression in 60%. At the 8th week, 27 patients were responder (CGI 1-2). 2 patients discontinued the trial and only one due to adverse events. CONCLUSIONS: Sertraline demonstrated excellent tolerability in these MAD patients, despite the high levels of baseline anxiety in the group. Efficacy was as high as described in patients with major depression. These results warrant further placebo controlled pharmacological trials of SSRI in MAD.

1-Naphthylamine↗
PubMedDate not supplied

[A study of personality in eating disorders].

UNLABELLED: Some evidence suggests that temperament and personality traits could influence the development and severity of eating disorders. This study was designed to study these aspects. METHODS: 72 patients with DSM-IV eating disorders including 25 anorexia nervosa restricting type, 17 with anorexia nervosa binge eating-purging type and 30 with bulimia nervosa were studied and compared with thirty healthy controls. Personality disorders and temperament were studied with the Eysenck's EPQ, Cloninger's TCI and SCID-II. Impulsive and clinical features were studied with specific rating scales. RESULTS: 61.8% of patients had at least one personality disorder. Avoidant personality disorder was the most commonly diagnosed in anorexia restricting type (25%). Borderline personality disorder was the most frequent in bulimia nervosa and in the binge eating-purging type of anorexia nervosa. Dimensionally, the group of eating disorders presented high scores in neuroticism and low scores in self-directedness. Higher harm avoidance was found in bulimic patients and higher persistence was associated with anorectic patients. Bulimic patients were significantly more impulsive than anorectic and controls. CONCLUSIONS: Temperament and personality traits differ in anorectic and bulimic patients. Bulimic symptoms are linked to impulsive temperament traits and to impulsive personality features. Anorectic symptoms are linked to persistent temperament traits and anxious personality features.

Adult↗