PubMed Health⌕ Search

Biomedical subjects

J M Castellanos

Publications and source records attributed to J M Castellanos.

At least 19 recordsLinked to original sources
PubMed2000

Short-term hypothyroidism has no effect on serum leptin concentrations.

The aim of the study is to determine the effect of short-term hypothyroidism on serum leptin levels. For this purpose 30 patients with past medical history of thyroidectomy for differentiated thyroid carcinoma were included. Serum leptin concentrations were similar when patients were on thyrotrophin-suppressive thyroxine therapy than when were admitted 4 weeks after stopping thyroxine treatment to perform a routine 131I scan in hypothyroid status (17.0 +/- s.e.m. 2.14 vs. 17.6 +/- s.e.m. 2.41 ng/ml; p = n.s.). Moreover, no differences were obtained when the analysis was performed separately in men and in women. We conclude that short-term hypothyroidism does not alter serum leptin concentrations. Furthermore, our results suggest that thyroid hormones do not operate through changes in serum leptin levels to regulate energy expenditure.

Female↗
PubMed2000

Influence of surgical stress and parenteral nutrition on serum leptin concentration.

UNLABELLED: Experimental studies suggest that leptin may be an important metabolic signal for energy regulation. AIM: To assess whether surgical stress produces changes in serum leptin concentration and to investigate and compare the effect of total parenteral nutrition and hypocaloric parenteral nutrition on serum leptin levels. PATIENTS AND METHODS: Twenty-two surgical patients (11 male and 11 female) in need of parenteral nutrition were recruited. Parenteral nutrition was always initiated 24 h after surgical procedure. Group I (n=15) received total parenteral nutrition, while Group II (n=7) were treated with hypocaloric parenteral nutrition. Serum leptin concentration was determined before surgical procedure (day -1), after surgery and before parenteral nutrition was started (day +1), and after 5 days of treatment with parenteral nutrition (day +6). RESULTS: A tendency to increase serum leptin levels was observed after surgical procedure (6.0+/-1.9 vs 9.9+/-2.7 ng/ml;P= 0.07). After starting parenteral nutrition no significant changes on serum leptin concentrations were found in both groups, but a trend to raise serum leptin was observed in Group I (6.2+/-1.7 vs 8.3+/-2.7 ng/ml) whereas a trend to decrease serum leptin was detected in Group II (4.6+/-2.5 vs 1.6+/-0.5 ng/ml). On day +6 an increase of serum leptin and insulin levels was observed in Group I in comparison with Group II (8.3+/-2.7 vs 1.6+/-0.5 ng/ml;P<< 0.05 and 58+/-41 vs 12+/-15 microU/l;P<< 0.05 respectively). Finally, a positive correlation at day +6 between insulin and serum leptin levels was observed (r= 0.66;P<< 0.01). CONCLUSIONS: a) Surgical stress is associated to an increase of serum leptin concentrations; b) Total and hypocaloric parenteral nutrition produces quite different effects on serum leptin levels that could be related to distinct insulin response.

Energy Intake↗
PubMed1998

Plasma corticotropin-releasing factor in depressive disorders.

BACKGROUND: The aim of this work was to investigate alterations of plasma corticotropin-releasing factor (CRF) levels in depressive states. We have also measured plasma cortisol and corticotropin (ACTH) concentrations and examined their correlation with the peripheral CRF values. METHODS: Thirty-six outpatients from the psychiatric department of a Barcelona hospital who were diagnosed as having major depressive disorder (n = 26) and dysthymic depressive disorder (n = 10) were studied. Among the major depressed patients, 10 suffered from severe depressive disorder and 16 from mild or moderate depressive disorder. The comparison group consisted of 17 healthy volunteers. Cortisol, ACTH, and CRF concentrations were determined by iodine-125 radioimmunoassay; CRF measurements were performed on C18 extracted samples. RESULTS: CRF and cortisol plasma concentrations were significantly higher in major depression and dysthymia than in the comparison group. The major depressed patients did not show significantly different CRF and cortisol levels than the dysthymic. Severe major depressive disorder exhibited significantly higher CRF plasma levels than the mild or moderate episodes. Plasma cortisol and CRF concentrations correlated significantly. CONCLUSIONS: The results obtained indicate that plasma CRF values are altered in depressive disorders and suggest that these determinations could be important for understanding the pathophysiology in affective illness.

Adrenocorticotropic Hormone↗
PubMed1998

Penetration of anti-DNA antibodies into immature live cells.

Several data suggest that immature lymphoid cells are more prone to penetration and therefore are affected more by antibodies than their mature counterparts. In this study, we examined the penetration of monoclonal anti-DNA antibodies in several models of immature cells. Results confirm that most anti-DNA antibodies penetrate larger proportions of immature cells than normal adult cells. It was also proven that anti-DNA antibodies induce larger fractions of immature cells to undergo apoptosis than mature cells; however, there is not a numerical association between penetration and apoptosis. Additionally, the penetration and induction of apoptosis of several anti-DNA monoclonal antibodies into U937 and NIH-3T3 cells followed a rather heterogeneous pattern. When mature and immature cells were stimulated polyclonally, it was shown that polyreactive antibodies might act as an accessory signal to induce apoptosis in immature cells. This process could contribute to the edition of the immune repertoire. We propose that naturally occurring polyreactive antinuclear antibodies, through penetration and deletion of self-reacting cells, could participate, either as a unique or secondary signal, in the mechanism of self tolerance. If these polyreactive antibodies undergo affinity maturation, it is possible they may develop into pathogenic antibodies.

3T3 Cells↗
PubMed1997

Decreased cholecystokinin levels in cerebrospinal fluid of patients with adult chronic hydrocephalus syndrome.

Cholecystokinin (CCK) levels were measured in cerebrospinal fluid (CSF) of patients with adult chronic hydrocephalus syndrome (ACHS) (n = 16) and compared with levels from a control group (n = 11). The CSF concentration of CCK in the ACHS group (0.79 +/- 0.53 fmol/mL) was significantly reduced (p = .002) with respect to the controls (1.55 +/- 0.54 fmol/mL). As CCK-8, the most prevalent from of CCK in the central nervous system, has been demonstrated to play a significant role in several physiological and behavioral actions, the reduced octapeptide values found in ACHS could be involved in the disturbances associated with this disorder. Continuous monitoring of intracranial pressure (ICP) demonstrated different ICP profiles in ACHS. We found that all patients with abnormal ICP records except one showed CCK values under the detection limit. Three of the 4 patients with normal ICP had CCK levels within the normal range. These preliminary studies could evidence that ICP alterations are responsible for part of the loss of brain neuropeptide levels in ACHS.

Adult↗
PubMed1997

Evaluation of immune markers in asymptomatic AIDS patients receiving fish oil supplementation.

The effects of oral fish oil (FO) supplementation (8 g/day, capsules) on nutritional status and selected immune markers (CD4/CD8 ratio, IL-1beta, erythrocyte MDA release, dehydroepiandrosterone sulfate [DHEA-S]) were studied in a homogeneous group of asymptomatic HIV-infected patients during 6 weeks. All subjects were classified clinically as A2 according to the CDC revised criteria (mean CD4 count 290 +/-123 cells/mm(3)) and were receiving zidovudine retroviral treatment. The calculated mean energy intake was 3437 +/- 372 Kcal/d, composed of 14% protein, 38% lipids and 48% carbohydrates, and was not modified during the study. The anthropometric parameters, and hematological and plasma biochemistry data showed non-significant changes after FO supplementation. Mean malonyldialdehyde (MDA) release before treatment was: unstimulated 71.5 +/- 37 and stimulated 350.9 +/- 79.8 nmol/g Hb. After FO supplementation (T(6)) MDA release showed unstimulated values of 96.1 +/- 62, and a significant increase after stimulation of 614.1 106.4 nmol/g Hb, which was, however, within the normal range. In the patient's samples, IL-1beta levels in the unstimulated blood culture showed a statistical increase with respect to the normal range before (T(0)) and after (T(6)) FO supplementation with a slight decrease after (mean 49.8 vs 40.9 pg/ml). The stimulated IL-1beta levels after treatment showed a statistically significant decrease that was maintained within the normal range (T(0): 797.7 vs T(6): 535.6 pg/ml). Taken collectively, these results suggest a tendency toward improvement in immune function.

Journal Article↗
PubMed1992

Neurokinin concentrations in cerebrospinal fluid. A preliminary study in Parkinson's disease.

Immunoreactive neurokinin A was measured in the cerebrospinal fluid of twelve patients with Parkinson's disease and eleven normal subjects, using a sensitive and precise extraction/concentration radioimmunoassay method. The mean value obtained in Parkinson's disease patients (13.2 +/- 4.6 pmol/l) was lower than that of the controls (17.4 +/- 5.9). The tendency toward a significant decrease (p = 0.085) found in this preliminary study could indicate that neurokinin A containing neurons are involved in the pathophysiology of Parkinson's disease. In addition, the establishment of reference values for neurokinin A in cerebrospinal fluid may provide a basis for further studies of this neuropeptide in neurological disorders.

Aged↗
PubMed1991

Somatostatin cerebrospinal fluid levels in dementia.

Somatostatin levels were measured in cerebrospinal fluid of patients with Alzheimer's disease, multi-infarct dementia and normal pressure hydrocephalus and compared with levels from a normal control group. All pathological groups showed a statistically significant decrease of somatostatin with respect to the control group, but no significant differences were found amongst them. A negative correlation was found between the Mini Mental State Test and the somatostatin levels in Alzheimer's disease patients but not in the other groups. Our results confirm that the lower levels of somatostatin in cerebrospinal fluid are not specific to Alzheimer's disease and indicate that the decrease found in all the groups is probably the result of neuronal destruction or damage in the diseases examined.

Adult↗
PubMed1991

Salivary cortisol levels and their correlation with plasma ACTH levels in depressed patients before and after the DST.

OBJECTIVE: The aim of this work was to study the clinical utility of salivary cortisol concentrations in a group of depressed patients undergoing the dexamethasone suppression test (DST) and the correlation of these concentrations with plasma ACTH levels. METHOD: Twenty outpatients from the psychiatric department of a Barcelona hospital who were diagnosed as having nonendogenous (N = 9) or endogenous (N = 11) depression according to DSM-III criteria and the Newcastle scale participated in the study. The comparison group consisted of 12 healthy volunteers. Blood and saliva samples were taken before and after administration of 1 mg of dexamethasone Salivary cortisol and plasma ACTH concentrations were determined by direct iodine-125 radioimmunoassay with commercial kit reagents. RESULTS: Predexamethasone salivary cortisol concentrations were significantly higher in the group with endogenous depression than in the comparison group. A significant correlation was obtained between plasma ACTH and predexamethasone salivary cortisol levels in the group with nonendogenous depression and in the comparison subjects. CONCLUSIONS: These preliminary findings indicate that salivary cortisol could substitute for plasma cortisol in clinical studies in which the DST and hypercortisolemia are evaluated. The lack of correlation between ACTH and cortisol levels in saliva in the group of endogenously depressed patients could indicate a disturbance in the regulation of cortisol secretion in major depression.

Adrenocorticotropic Hormone↗
PubMed1990

Cerebrospinal fluid neuropeptide Y in Alzheimer's disease.

The cerebrospinal fluid neuropeptide Y level was measured by radioimmunoassay in 20 patients with probable Alzheimer's disease and in 19 controls. The mean level was lower in patients (69.5 +/- 36.7 pg/ml) than in controls (103 +/- 21.8 pg/ml; p less than 0.001). Patients with a disease duration of greater than 2 years had cerebrospinal fluid neuropeptide Y levels lower than those with shorter disease duration (p less than 0.02). These results suggest that neuropeptide Y containing cells may be involved in Alzheimer's disease. No correlation was found between neuropeptide Y levels and degree of cognitive impairment or age at disease onset.

Aged↗
PubMed1988

Plasma levels of beta-endorphin, cortisol, prolactin and growth hormone in depressed patients.

Basal serum cortisol, growth hormone, prolactin and immunoreactive (IR) plasma beta-endorphin levels were measured in 31 depressed patients (14 endogenous, 17 nonendogenous) undergoing the dexamethasone suppression test. The endogenously depressed patients had significantly higher (22.55 +/- 1.34 micrograms/dl) predexamethasone cortisol levels than the nonendogenous patients (16.34 +/- 1.93 micrograms/dl). The mean serum prolactin and growth hormone values of these two groups were not significantly different, while plasma IR-beta-endorphin levels of the endogenous group (40.11 +/- 3.57 pg/ml) were significantly lower than those of the nonendogenous group (120.33 +/- 27.98 pg/ml). Neither group showed a significant correlation between plasma IR-beta-endorphin and serum cortisol values. These results indicate that measurement of predexamethasone serum cortisol values and plasma IR-beta-endorphin could be valuable laboratory tests in the diagnosis of depression.

Adult↗
PubMed1987

Salivary testosterone levels in infertile men.

Salivary testosterone levels were measured in 18 normal men, 29 oligospermic and six azoospermic subjects, using a specific and sensitive radioimmunoassay (RIA). There was a significant reduction (P less than 0.001) in salivary testosterone levels in the group of oligospermic (0.266 +/- 0.086 nmol/l) and azoospermic (0.234 +/- 0.055 nmol/l) subjects when compared with controls (0.348 +/- 0.070 nmol/l). A good correlation was found between salivary and plasma testosterone levels in normal (r = 0.62, P less than 0.01) and infertile men (r = 0.58, P less than 0.01). This study demonstrates that salivary testosterone levels, a non-invasive means of sample collection, may be used for evaluation of androgen status in male infertility.

Adult↗
PubMed1986

Sensitivity of anterior pituitary hormones to graded levels of psychological stress.

The effect of graded levels of stressor intensity on anterior pituitary hormones was studied in adult male rats. Corticosterone, considered as a reflection of ACTH release, and prolactin responses showed a good correlation with the intensity of the stressors. On the contrary, neither LH, GH nor TSH release showed a parallelism with the intensity of the stressors in spite of the fact that they clearly responded to all the stimuli. It appears that the hormones of the anterior pituitary might be divided into two groups: those whose response is sensitive to the levels of emotional arousal elicited by stress, and those displaying a clear but stereotyped response during stress. However, other alternative explanations might exist to justify the present results. The neural mechanisms underlying the two types of response are at present unknown. These data indicate that only the pituitary-adrenal axis and prolactin have some potential utilities as quantitative indices of emotional arousal elicited by currently applied stressors in the rat.

Animals↗
PubMed1985

Dissociation between adrenocorticotropin and corticosterone responses to restraint after previous chronic exposure to stress.

The effect on emotional reactivity produced by a model for chronic stress in which different types of acute stresses were randomly combined for 29 days was studied in adult male rats. Chronically stressed rats showed a slight decrease in body weight gain and an increase in relative adrenal weight. Chronic stress did not modify defecation rate but reduced exploratory activity in the holeboard. Neither basal nor acute-stress induced levels of adrenocorticotropin (ACTH) were modified by previous chronic stress. Likewise, basal corticosterone levels were similar in both groups. However, corticosterone response to acute restraint stress was higher in chronically stressed than in control rats. The mechanisms underlying the dissociation between ACTH and corticosterone as well as its possible implications are discussed.

Adrenocorticotropic Hormone↗