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Biomedical subjects

J Vallejo

Publications and source records attributed to J Vallejo.

At least 37 records · Page 2Linked to original sources

Hemispheric functional imbalance in a sub-clinical obsessive-compulsive sample assessed by the Continuous Performance Test, Identical Pairs version.

Obsessive-compulsive disorder (OCD) sufferers have long been observed to give excessive consideration to normally ignored exogenous and endogenous stimuli. This over-focused attention concerning their symptoms has led researchers to experimentally investigate the attentional mechanisms involved in this disorder and its psychobiological basis. Previous psychometric and neuropsychological research has demonstrated the validity of the sub-clinical analogue in the study of the mechanisms underlying OCD. In this study, 71 introductory university students were recruited from an original pool of 450 people on the basis of their scores on the Spanish version of the Padua Inventory. A high obsessive group (n = 35) was compared with a control group (n = 36) on a standard sustained attention task: the Continuous Performance Test, Identical Pairs version (CPT-IP). The results showed a significant interaction effect between CPT-IP subscales (verbal and spatial) and group membership. This effect was more evident among men. The results were unrelated to general intelligence, depression, anxiety, personality or motivational factors. These findings support the hypothesis that neuropsychological deficits in OCD may be related to a hemispheric functional imbalance rather than to a lateralised dysfunction of a particular hemisphere.

Adolescent↗

Regional distribution of specific high affinity binding sites for 3H-imipramine and 3H-paroxetine in human brain.

The binding of 3H-paroxetine and 3H-imipramine has been compared in 17 different regions of 12 human control brains. Our findings reveal that the regional distribution is similar for both radioligands and their bindings tend to be parallel in the brain. The highest binding site density was found in basal ganglia (hypothalamus Bmax 780 +/- 102 fmol/mg protein for 3H-imipramine binding and Bmax 515 approximately 83 for 3H-paroxetine binding). The lowest values were found in cortical areas (cingulate cortex 191 +/- 18.5 fmol/mg for 3H-imipramine binding and 88 +/- 7.5 fmol/mg for 3H-paroxetine binding). The Kd values for 3H-paroxetine binding to neuronal membranes were similar in all brain regions (mean +/- s.d. Kd 0.07 +/- 0.007 nM) and also for 3H-imipramine binding (mean +/- s.d. Kd 1.05 +/- 0.12 nM). As these values are the same as in platelet membrane, the results obtained indicate that both binding sites are identical in neuronal and in platelet membranes. These findings suggest that both ligands are good markers of the 5HT transporter. However, the higher affinity of 3H-paroxetine confirms that this compound is a better radioligand for the 5HT uptake site.

Adult↗

High affinity [3H]imipramine and [3H]paroxetine binding sites in suicide brains.

Specific binding of [3H]imipramine and [3H]paroxetine was simultaneously examined in human brains (frontal cortex, temporal cortex, cingulate cortex, hypothalamus, hippocampus and amygdala) from 11 controls and 11 depressed suicide victims. A single saturable high affinity site was obtained for both radioligands. Age was not related to significant changes in [3H]imipramine and [3H]paroxetine binding parameters, which indicates the stability of the brain serotonergic system with increasing age. A major finding of the present study concerns the existence of a significant decrease in the maximum number (Bmax) of [3H]imipramine binding sites in hippocampus from depressed suicides as compared with the control group, without changes in the binding affinity (Kd). In contrast, when [3H]paroxetine was used as radioligand, no changes in either Bmax or Kd were detected in any of the brain regions studied. These findings suggest that [3H]imipramine may be a better marker than [3H]paroxetine when alterations in the presynaptic serotonergic uptake site are to be detected.

Adolescent↗

Chemical and thermal stability of ferulic acid esterase-III from Aspergillus niger.

The stability of ferulic acid esterase III (FAE-III) from Aspergillus niger was examined using chemical and thermal denaturation. Thermal denaturation was irreversible and the loss of activity was dependent on pH. At 60 degrees C and pH 6.0, the rate constant of unfolding was 0.76 10(-3)/s, and the change in free energy of irreversible inactivation, deltaG*, was 101.9 kJ/mol. Sinapic acid, a product of the reaction of methyl sinapate with FAE-III, reduced the rate of unfolding (0.66 10(-3)/s at 0.1 mM sinapic acid). Chemical denaturation was performed using guanidine hydrochloride. FAE-III was very sensitive to this denaturant, and the midpoint of unfolding was 1.38 M guanidine hydrochloride at 30 degrees C, pH 6.0. The stability of FAE-III is compared to other enzymes.

Aspergillus niger↗

Platelet [3H]imipramine and [3H]paroxetine binding in depressed patients.

[3H]Paroxetine and [3H]imipramine binding to blood platelet membranes was simultaneously measured in 63 control subjects and 18 patients with DSM-III-R criteria for major depression with melancholia. Both binding sites showed significantly different (p < 0.001) maximum binding (Bmax) and equilibrium dissociation constant (Kd) values. Age was not correlated with either [3H]imipramine Bmax or Kd values, but a negative correlation was found between [3H]paroxetine Bmax and age in healthy controls. Furthermore, depressed patients showed significantly lower [3H]imipramine Bmax values (p < 0.001) and higher Kd values (p < 0.001) in comparison to the control group. No differences were observed in [3H]paroxetine Bmax and Kd values between the two groups.

Adult↗

Prediction of depressive relapse in remitted bipolar patients using corticotrophin-releasing hormone challenge test.

Abnormalities in corticotrophin (ACTH) and cortisol levels before and after corticotrophin-releasing hormone (CRH) stimulation have been reported in depressed bipolar patients. The ACTH and free cortisol response to the injection of 100 micrograms of synthetic human CRH and plasma cortisol-binding globulin (CBG) levels were measured in 42 lithium-treated patients suffering from RDC bipolar-I disorder in remission, and in 21 age- and sex-matched control subjects. A 1-year follow-up was conducted in order to assess any possible relationship between outcome and the hormonal response. Bipolar patients showed higher baseline and peak ACTH concentrations than controls. A lower net area under the ACTH concentration curve after CRH stimulation predicted depressive relapse within 6 months by multiple regression analysis. The CRH challenge test could be a potentially good predictor of depressive relapse in remitted bipolar patients.

Adrenocorticotropic Hormone↗

Seasonal variability in blood platelet 3H-imipramine binding in healthy controls: age and gender effects.

Binding of 3H-imipramine to blood platelet membranes was determined four times (once each season) in 26 healthy volunteers (11 men and 15 women), over the course of 1 year to determine possible seasonal variations. Blood platelets were obtained in April-May, July-August, October-November, and January-February. Significant seasonal variations in the maximum number of binding sites were found in women but not in men, with circannual peak in summer and a nadir in spring. The pattern of seasonal variations was not the same in men and women. The present results highlight the importance of monitoring for gender and season in binding studies. We found no significant correlation between 3H-imipramine binding parameters and age.

Adult↗

Growth hormone response to growth hormone releasing hormone in non-delusional and delusional depression and healthy controls.

Growth hormone (GH) responses to growth hormone releasing hormone (GHRH) of 53 in-patients meeting DSM-III-R criteria for major depressive episode with melancholia (24 non-delusional and 23 delusional depression) were compared with those of 19 healthy controls. No significant differences in basal GH were found between the control and either the non-delusional or the delusional groups. The whole group of depressed patients showed a significantly lower response than the control patients at all points of the GH response to GHRH curve as well as a lower area under curve. When the three groups (control, delusional, and non-delusional depressed) were compared, it was found that only the non-delusional depressed patients had a significantly lower area under curve and lower values at +60, +90 and +120 min than the controls. The only significant difference between the two groups of depressed patients was that the delusional group showed a delayed appearance of the maximum response peak and a more prolonged response.

Adult↗

[PSA and PSAD study in patients with renal dysfunction].

This study analyzes the changes in serum and urinary PSA values in 28 subjects; 13 with creatinine clearance under 75 ml/mn and 15 with creatinine clearance over 75 ml/mn. Both groups were compared for prostate size, measured by transrectal ultrasound, prostate weight, serum PSA (SPSA), 24h urine PSA (PSAO), PSA clearance (PSACl), serum creatinine (SCr), creatinine clearance (CrCl), PSA density (PSAD), PSA/creatinine ratio (PSA/Cr) and PSACl/CrCl ratio. Mean values of SPSA and PSAO were 4.5 +/- 0.8 and 222 +/- 29.7 ng/ml respectively, values for SCr, CrCl and PSACl averaging 1.62 +/- 0.2 mgr/dl, 71.6 +/- 6.5 ml/mn and 150.5 +/) 32.9 ml/mn. Median prostate size was 32.6 +/- 3.9 cc, with weights of 40.3 +/- 4.9 g and mean PSA density (PSAD) 0.13 +/- 0.02. The results of the homogeneity study showed that there are no significant differences between both groups with regard to the variables considered in the study. SPSA values were higher in patients with CrCl < 75; 3.4 vs 5.7, but not significantly. There are no significant differences between PSAO and PSACl values for both groups, even though PSAO levels were higher in patients with CrCl < 75 ml/min (p = 0.1). PSAD values for patients with CrCl > 75 ml/mn were lower than those for patients with CrCl < 75 ml/mn; 0.09 vs 0.17 (p = 0.08). In the entire sample, PSAD levels showed correlation with SPSA and PSA/Cr values; R = 0.63 (P = 0.0003) and r = 0.5 (p = 0.009) respectively. Also, they were significantly but inversely correlated with PSACl levels; r = - 0.5 (p = 0.006) and PSACl/CrCl; r = - 0.048 (p = 0.01). No correlation was seen between PSAD values and the following parameters; PSAO (p = 0.7), SCr (p = 0.5) and CrCl (p = 0.27). When the group of patients with CrCl < 75 ml/mn is considered, PSAD values are correlated exclusively with PSACl values; r = - 0.69 (p = 0.008) and PSACl/CrCl; r = 0.68 (p = 0.009). Our data appear to indicate that there is a certain relationship between PSAD and the renal function although the physiopathological mechanism responsible for that is unknown. Nevertheless, considering the sample size, more comprehensive studies will be necessary to obtain more convincing results.

Aged↗

[Scientific investigation in biomedicine and health sciences in Andalusia].

OBJECTIVES: To evaluate the scientific output in Biomedicine and Health Sciences in Andalusia in the context of the published works on the national scientific output in the last few years. MATERIAL: Descriptive study with seven different information sources: a) final Report of the Experts Committee on Documentation from the Consejería de Salud de la Junta de Andalucía (IME: Indice Médico Español) suplemento internacional: 1980-1994; b) MEDLINE (Comprehensive Medline Ebsco, 1987-1993); c) EMBASE (Excerpta Medica; Elsevier Science Publisher) (1986-1994); d) IME, mechanized version: 1974-1993; Anales del FIS (1989-1993); e) Memoria REUNI: 1993-1994, and f) call for and resolution of research projects from the Consejería de Salud de la Junta de Andalucía (1994). RESULTS AND CONCLUSIONS: Scientific output in health sciences in Andalusia has gown in parallel with the national output from other communities. Nevertheless, in absolute terms this output is scant and the big difference compared with Catalonia and Madrid--the two Autonomous Communities with the largest scientific output--remains unchanged. Grenada is the Andalusian province with the largest output, with Seville, Cordoba and Malaga ranking next. The output in the other Andalusian provinces is very small. The output is apparently independent from the number of inhabitants or the historic presence of a Medicine School. In contrast with Catalonia and Madrid, where the largest output originates in hospitals, the largest output in Andalusia comes from Universities; this fact suggests relevant differences in scientific sub-structure. This suggestion is also endorsed by the lower competition of Andalusia to obtain resources and the lower number of research scholarships. With these results in mind a scientific policy of positive discrimination is proposed which allows the Andalusian Autonomous Community to reach the standard of scientific output in biomedicine and health sciences according to its socioeconomic status.

Databases, Bibliographic↗

Changes in platelet 3-H-imipramine binding: influences of protein concentration of varying proportions of cytosol or intact platelets and displacing agents used.

Platelet 3-H-imipramine binding exhibits considerable variation, both interindividually and between several groups. The aim of this study was to measure 3-H-imipramine binding, simultaneously in platelet membranes vs. intact platelets vs. cytosol or intracytosolic protein in order to determine their effect on Bmax and Kd values. 3-H-imipramine binding was carried out at different protein concentrations. Our results indicate that the affinity constant is heavily influenced by the presence of cytosol and intact platelets in membrane preparations. Finally, we demonstrate a negative correlation between Bmax and protein concentration. Only perfect analytical conditions will allow platelet 3-H-imipramine binding to be a biological marker for affective disorders.

Binding, Competitive↗

[Diagnostic yield of Echo-Doppler in dysfunction of the grafted kidney].

The study's goal is to analyze the usefulness of Eco-Doppler in the knowledge of renal graft hemodynamics and the description of its dysfunction. 234 examinations were performed in 110 patients. Acceleration, mean rate (MR), maximum systolic rate (MXSR) and minimal diastolic rate (MNDR), as well as resistance index (RI) and pulsatility index (PI) were determined in the external iliac, renal, segmentary, interlobular and arcuate arteries. RI and PI, as well as MXSR and the acceleration are higher in the extra-parenchymatous versus the intra-parenchymatous beds. Peak MR and MNDR values are reached in the renal artery. Termino-lateral to external iliac arterial anastomosis conditions higher MXSRs in the renal artery as opposed to termino-terminal to hypogastric artery (p < 0.05). In the arcuate artery, RI > 0.8 is reached in 51.6% of acute tubular necrosis (ATN), 46.9% of acute rejections (CR), 46.3% of chronic rejection (AR), 21% of grafts with cyclosporin-induced nephrotoxicity (NFX) and 12.5% of normal functioning kidneys isolated chance analysis with Eco-Doppler does not distinguish between AR and ATN. A dysfunctional graft with an RR in the arcuate artery of nearly 9.7 suggests NFX, but AR with interstitial predominance cannot be ruled out.

Acute Disease↗

Anxiety disorders in the joint hypermobility syndrome.

A case-control study was designed to test the association between joint hypermobility syndrome (JHS), an inherited disorder of collagen synthesis, and anxiety and phobic disorders. One hundred fourteen cases of JHS diagnosed at the rheumatology outpatient clinic of the Hospital del Mar (Barcelona) were compared to 59 control subjects randomly selected from patients seen at the same clinic. Both cases and controls were examined by a psychologist who used the Structured Clinical Interview for DSM-III-R and who was unaware of their medical diagnoses. DSM-III-R diagnoses of panic disorder, agoraphobia, and simple phobia, but not generalized anxiety disorder, dysthymic disorder, or major depression were found to be highly associated with JHS (age- and sex-adjusted odds ratio = 10.7). Mitral valve prolapse (MVP) was present only among JHS cases. Among cases of JHS, subjects with MVP were almost three times more likely to suffer from anxiety than subjects without MVP (odds ratio = 2.95), although the association was not statistically significant. The strong association between panic anxiety and JHS appears to occur at a higher level than the association between panic and MVP, and provides a new basis for further studies on the genetic background of panic-anxiety.

Adult↗

[A program of intracavernous drug-induced erection for the treatment of impotence].

The study includes 138 patients with erectile dysfunction, all of them previously treated with intracavernous injections. Following study and classification of the type of impotence, they were all included in one of the four following groups. The drugs used were, in group I (73 patients) Prostaglandins E1, in group II (37 patients) Papaverine, in group III (6 patients) a combination of Papaverine and Phentolamine and in group IV (22 patients) a combination of Papaverine and Prostaglandins E1. We found a good treatment response in 59.3% cases (60.3% in group I, 51.3% in group II, 66.7% in group III, and 69% in group IV). We outline the better results obtained in group IV, as well as the reduced number of complications in our series.

Administration, Topical↗

Control of massive hematuria in idiopathic hemorrhagic cystitis after administration of conjugated estrogen.

A renal transplant patient with severe hemorrhagic cystitis of idiopathic etiology was treated initially with intravenous administration of conjugated estrogen (1 mg./kg.), followed on day 2 and thereafter with 5 mg. per day orally for 3 weeks. Hematuria decreased in intensity within 10 hours and disappeared within 48 hours. Hematuria did not recur by 6 months after completion of oral doses of conjugated estrogen. Complications or other side effects were not observed. In our experience conjugated estrogen controls hematuria in patients with idiopathic hemorrhagic cystitis and this form of treatment must be considered in this condition.

Acute Disease↗