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Biomedical subjects

Carlos A Gonçalves

Publications and source records attributed to Carlos A Gonçalves.

16 recordsLinked to original sources
PubMed2006

Increased serum glial cell line-derived neurotrophic factor immunocontent during manic and depressive episodes in individuals with bipolar disorder.

Glial cell line-derived neurotrophic factor (GDNF) is a neurotrophic factor from the transforming growth factor beta family, which plays a role in the development and function of hippocampal cells. Preclinical studies suggest that changes in neurotrophic growth factor systems might be involved in the pathophysiology of mood disorders including bipolar disorder (BD) [E.J. Nestler, M. Barrot, R.J. DiLeone, A.J. Eisch, S.J. Gold, L.M. Monteggia, Neurobiology of depression, Neuron 34 (2002) 13-25]. This is the first study to analyze GDNF immunocontent in BD subjects across different mood states, including mania, depression, and remission (euthymia). Fourty-four bipolar patients (14 depressed, 15 manic, and 15 euthymic) and 14 healthy controls, diagnosed according to the Structural Clinical Interview for DSM-IV were studied. Serum GDNF immunocontent was measured using Western blotting. Serum GDNF immunocontent was increased in manic (F=42.31; p=0.001; one-way ANOVA) and depressed (F=42.31; p=0.004; one-way ANOVA) bipolar patients, but not in euthymic patients as compared with controls. Our results indicate that changes in GDNF immunocontent occur during acute major affective episodes in bipolar subjects. These results further support the role of neurotrophins in the pathophysiology of bipolar disorder. Whether the observed increase in GDNF immunocontent correspond to a pathological or an adaptive response remains to be determined.

Adult↗
PubMed2006

Effect of 2-deoxy-D-glucose on aminoacids metabolism in rats' cerebral cortex slices.

We studied the effect of different concentrations of 2-deoxy-D-glucose on the L-[U-14C]leucine, L-[1-14C]leucine and [1-14C]glycine metabolism in slices of cerebral cortex of 10-day-old rats. 2-deoxy-D-glucose since 0.5 mM concentration has inhibited significantly the protein synthesis from L-[U-14C]leucine and from [1-14C]glycine in relation to the medium containing only Krebs Ringer bicarbonate. Potassium 8.0 mM in incubation medium did not stimulate the protein synthesis compared to the medium containing 2.7 mM, and at 50 mM diminishes more than 2.5 times the protein synthesis compared to the other concentration. Only at the concentration of 5.0 mM, 2-deoxy-D-glucose inhibited the CO2 production and lipid synthesis from L-[U-14C] leucine. This compound did not inhibit either CO2 production, or lipid synthesis from [1-14C]glycine. Lactate at 10 mM and glucose 5.0 mM did not revert the inhibitory effect of 2-deoxy-D-glucose on the protein synthesis from L-[U-14C]leucine. 2-deoxy-D-glucose at 2.0 mM did not show any effect either on CO2 production, or on lipid synthesis from L-[U-14C]lactate 10 mM and glucose 5.0 mM.

Animals↗
PubMed2006

Evidence of astrogliosis in rat hippocampus after d-amphetamine exposure.

INTRODUCTION: Psychostimulants such as amphetamine (AMPH) induce manic-like symptoms in humans and studies have suggested that bipolar disorder (BD) may be associated to dopamine dysfunction. Glial fibrillary acidic protein (GFAP) up-regulation is considered a marker of astrogliosis, and it has been associated to behavioral sensitization. PURPOSE: We aimed to investigate the behavioral effects of acute and chronic AMPH on rat locomotion and assess GFAP levels in rat cortex and hippocampus. METHODS: Rats were administered either acute (single dose) or chronic (seven days) d-amphetamine IP injection. Locomotion was assessed with an open-field test and GFAP immunoquantity was measured using ELISA. RESULTS: Chronic, but not acute, administration of AMPH increased GFAP levels in rat hippocampus. No differences were observed in rat cortex. CONCLUSIONS: Repeated exposure to AMPH leads to an astroglial response in the hippocampus of rats.

Analysis of Variance↗
PubMed2006

Serum brain-derived neurotrophic factor is decreased in bipolar disorder during depressive and manic episodes.

Genetic and pharmacological studies have suggested that brain-derived neurotrophic factor (BDNF) may be associated with the pathophysiology of bipolar disorder (BD). The present study investigated serum BDNF levels in manic, depressed, euthymic BD patients and in matched healthy controls, using an enzyme-linked immunosorbent assay (sandwich-ELISA). Serum BDNF levels were decreased in manic (p=0.019) and depressed (p=0.027) BD patients, as compared with euthymic patients and controls. Serum BDNF levels were negatively correlated with the severity of manic (r=-0.37, p=0.005) and depressive (r=-0.30, p=0.033) symptoms. These findings further support the hypothesis that the BDNF signaling system may play a role in the pathophysiology of BD.

Adult↗
PubMed2006

Glial fibrillary acidic protein expression after electroconvulsive shocks in rat brain.

OBJECTIVE: The aim of the present study was to assess the effect of electroconvulsive shock (ECS) in glial fibrillary acidic protein (GFAP) expression in rat brain. METHODS: Rats were given either a single (acute) or a series of eight (chronic) ECS. Brain regions were isolated and levels of glial fibrillary acidic protein (GFAP) in the brain tissue (cortex, hippocampus, and cerebellum) were assessed using an enzyme-linked immunosorbent assay (ELISA). RESULTS: We showed that GFAP expression is reduced in the hippocampus within 48 h and 7 days after acute ECS. GFAP levels are increased in the cerebellum immediately after acute and chronic ECS. No changes were observed in the cortex. CONCLUSIONS: Our findings showed a differential effect of acute and chronic ECS in the astroglial response in the brain of rats.

Analysis of Variance↗
PubMed2006

Effects of protein malnutrition on oxidative status in rat brain.

OBJECTIVES: This study evaluated the effects of protein malnutrition on oxidative status in rat brain areas. METHODS: We investigated various parameters of oxidative status, free radical content (dichlorofluorescein formation), indexes of damage to lipid (thiobarbituric acid-reactive substances assay), and protein damage (tryptophan and tyrosine content) in addition to total antioxidant reactivity levels and antioxidant enzyme activities of superoxide dismutase, glutathione peroxidase, and catalase in different cerebral regions (cortex, hippocampus, and cerebellum) from rats subjected to prenatal and postnatal protein malnutrition (control 25% casein and protein malnutrition 7% casein). RESULTS: Protein malnutrition altered various parameters of oxidative stress, especially damage to macromolecules. Free radical content was unchanged by protein malnutrition. There was an increase in levels of thiobarbituric acid-reactive substances, the index of lipid peroxidation, in the cerebellum and cerebral cortex (P < 0.05) from protein-malnourished rats. Moreover, significant decreases in tryptophan and tyrosine in all tested brain structures (P < 0.05) were observed. Catalase activity was significantly decreased in the cerebellum (P < 0.05). In addition, a significant decrease in total antioxidant reactivity levels (P < 0.05) was observed in the cerebral cortex from protein-malnourished rats. CONCLUSIONS: The present data indicated that protein malnutrition increased oxidative damage to lipids and proteins from the studied brain areas. These results may be an indication of an important mechanism for changes in brain development that are caused by protein malnutrition.

Animals↗
PubMed2005

The ischemic rat heart releases S100B.

S100B is an astrocytic protein assessed in cerebrospinal fluid and serum as a biochemical marker of cerebral injuries. However, increasing evidences suggest the influence of extra cerebral sources on its serum levels. Since it was reported that the injured myocardium expresses S100B, we investigated whether the isolated heart releases this protein. The rat hearts were excised and perfused by the Langendorff technique of isolated heart perfusion. After stabilization, 10 hearts (ischemic group) were submitted to 20 minutes of ischemia and 30 minutes of reperfusion, and 5 hearts (control group) were submitted to 50 minutes of perfusion. The perfusion fluid was collected at pre-ischemia, and 0, 5, 10, 15 and 30 min after ischemia (or equivalent in controls) for S100B and cardiac troponin T (a heart injury marker) assays. In the ischemic group, S100B and troponin T levels increased significantly at time 0 min: S100B values [mug/L, median (IQ25/IQ75)] increased from < or = 0.02 (< or = 0.02/0.03) to 0.38 (0.22/0.84), while troponin T values [mug/L, median (IQ25/IQ75)] increased from 0.31 (0.15/0.45) to 2.84 (2.00/3.63). Our results point to the ischemic heart as an extra cerebral source of S100B.

Animals↗
PubMed2004

Specificity and sensitivity of S100B levels in amniotic fluid for Down syndrome diagnosis.

Down syndrome (DS) is the most common chromosomal abnormality and is associated with an extra copy of the chromosome 21. Although several markers are commonly used during pregnancy for the screening of DS, the definitive diagnosis is based on karyotype after amniocentesis, which is an expensive and laborious analysis. S100B is an astrocyte protein which had its gene mapped to the long arm of chromosome 21. Previous preliminary reports have found increased levels of this protein in the amniotic fluid of DS gestations. Aiming to achieve a simpler and cheaper test then karyotype to perform prenatal diagnosis of DS, here we have extended our previous studies and evaluated the real usefulness of amniotic S100B measurement for prenatal DS diagnosis. We have measured S100B in amniotic fluid of 96 pregnancies with DS and of 50 normal pregnancies. Pregnancies with DS presented significantly higher amniotic fluid S100B levels (M = 1.16 ng/mL; IQ = 0.83/1.78) than normal pregnancies (M = 0.51 ng/mL; IQ = 0.38/0.83) (p < 0.0001). A receiver operating characteristic (ROC) curve was performed to evaluate the sensitivity and specificity of S100B for DS diagnosis, and presented an area under the curve (AUC) of 0.82, indicating that S100B could be a reliable marker of DS. Moreover, values above 1.67 ng/mL were present only in DS fetuses, representing about 30% of affected pregnancies. However, as an overlap of values was observed between normal and DS gestations, we concluded that amniotic S100B alone is not a good test to discard DS diagnosis.

Adult↗
PubMed2003

Influence of anticoagulants on the measurement of S100B protein in blood.

OBJECTIVE: Evaluate anticoagulants influence on plasma S100B levels. DESIGN AND METHODS: Blood were collected from 18 healthy adult subjects using: no anticoagulants, EDTA, heparin, and citrate. S100B levels were determined using LIA-mat assay. RESULTS: Heparin plasma and citrate increased plasma S100B levels (p < 0.001), whereas EDTA had no effect (p = 0.24). Heparin plasma samples were highly (r2 = 0.97, p < 0.001), citrate samples were moderately (r2 = 0.49, p < 0.001), and EDTA samples were not (r2 = 0.22, p = 0.059) correlated with serum samples. CONCLUSIONS: When anticoagulant is required, heparin plasma should be the primary choice for measurement of S100 B levels.

Adult↗
PubMed2003

Influence of anticoagulants on the measurement of S100B protein in blood.

OBJECTIVE: Evaluate anticoagulants influence on blood S100B levels. DESIGN AND METHODS: Blood from 18 healthy adult subjects were collected using: no anticoagulants; EDTA; heparin; and citrate. S100B levels were determined using LIA-mat assay. RESULTS: Heparin and citrate increased S100B levels (p<0.001), whereas EDTA had no effect (p=0.24). Heparin samples were highly (r2=0.97, p<0.001), citrate samples were moderately (r2=0.49, p<0.001), and EDTA samples were not (r2=0.22, p=0.059) correlated with serum samples. CONCLUSION: When anticoagulant is required, heparin should be the primary choice.

Adult↗
PubMed2003

Increase in serum S100B protein level after a swimming race.

Physical activity has been shown to be a beneficial stimulus to the central and peripheral nervous systems. The S100B is a cytokine physiologically produced and released predominantly by astrocytes on the central nervous system (CNS). In order to study the possible influence of a nonimpact exercise on S100B serum levels, we measured this protein serum level after a 7,600-meter swimming race. We observed an increase in S100B levels in athletes post-race compared with their baseline values, pointing to a potential acute influence of physical exercise on serum S100B levels not related with CNS injury. We discuss this result and emphasize the possible central and peripheral origins of S100B serum levels.

Adolescent↗
PubMed2002

Elastic fibres in the human placenta.

Recent studies described the presence of elastic fibres within stem villi of human term placenta. This particular study focuses on changes of the elastic fibre system in placental villous tree from placentas of different gestational ages. The presence of elastic fibres was researched by light and electron microscopy in first-, second-trimester and term human placentas. Light microscopic analysis revealed elastic fibres in the stroma of main stem villi and in large vessels present in the chorionic plate of term placentas. Transmission electron microscopy revealed a wide variation in microfibrillar component deposition in placentas from all the gestational ages studied. Although minimal amount of the microfibrillar component was observed only in some main stem villi of second-trimester placentas, abundant microfibrillar material was present in all types of placental villi in placental sections from term pregnancies. The amorphous component was only occasionally identified in sections from the chorionic plate of second trimester placentas. In ultra-thin sections from placental tissues from the 37th to the 42nd weeks of gestation, we can observe the amorphous component of the elastic fibres. Bundles of microfibrils with scanty participation of the amorphous component of the elastic fibres can be observed in stem villi. In mature intermediate villi, cells and their processes with distinct plasma membranes were seen close to some bundles of microfibrillar component, at times with small spots of the amorphous component. This study shows that elastic fibres of the villous stroma, are mainly composed of the microfibrillar component, while the amorphous component appears more frequently in advanced stages of villous differentiation of term placentas.

Elastic Tissue↗
PubMed2002

Glutamate uptake in cultured astrocytes depends on age: a study about the effect of guanosine and the sensitivity to oxidative stress induced by H(2)O(2).

Relatively few studies have been conducted to investigate the relationship between glutamate and development and/or aging. Rat cortical astrocyte cultures were used as a model to investigate glutamate uptake during development. The immunocontent of the markers glial fibrillary acidic protein (GFAP) and S100B increased, while basal secretion of S100B decreased, in astrocytes from 10 to 40 days in vitro (DIV). Basal glutamate uptake increased with age. Exposure to hydrogen peroxide decreased glutamate uptake more potently at 40 than 10 DIV. Moreover, 40 DIV astrocytes showed earlier loss of integrity (at 6 h) than 10 DIV astrocytes (at 24 h) after H(2)O(2) exposure. Addition of guanosine stimulated glutamate uptake only in 10 DIV astrocytes. The present work shows that mature astrocytes in culture present some neurochemical alterations also observed in astrocytes of aged animals. These results can contribute to the understanding of some consequences of the excitotoxicity and oxidative stress during brain aging.

Aging↗
PubMed2002

Serum S100B levels in patients with lupus erythematosus: preliminary observation.

S100B is an astrocytic calcium-binding protein which has been proposed as a biochemical marker of brain damage or dysfunction in acute and chronic diseases. We investigated whether serum S100B levels could be related to systemic lupus erythematosus (SLE) activity. Patients were grouped as having inactive SLE (ISLE), active SLE without central nervous system (CNS) involvement (ASLE), or active SLE with unequivocal neurologic or psychiatric manifestation (NPSLE). The control group consisted of age- and sex-matched healthy blood donors. S100B levels were determined using a luminescence immunoassay. All SLE groups had higher levels of serum S100B than the control group. Among the SLE groups, significantly higher levels of serum S100B protein were found in the NPSLE group than in the ISLE and ASLE groups, and there was no significant difference in S100B levels between the ISLE and ASLE groups. These preliminary results point to a putative relevance of serum S100B protein levels in SLE patients, specifically concerning CNS involvement present in this disease.

Adult↗