55 resultados para pathophysiology
em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo
Resumo:
Objective: There is accumulating evidence that the limbic system is pathologically involved in cases of psychiatric comorbidities in temporal lobe epilepsy (TLE) patients. Our objective was to develop a conceptual framework describing how neuropathological, neurochemical and electrophysiological aspects might contribute to the development of psychiatric symptoms in TLE and the putative neurobiological mechanisms that cause mood disorders in this patient subgroup. Methods: In this review, clinical, experimental and neuropathological findings, as well as neurochemical features of the limbic system were examined together to enhance our understanding of the association between TLE and psychiatric comorbidities. Finally, the value of animal models in epilepsy and mood disorders was discussed. Conclusions: TLE and psychiatric symptoms coexist more frequently than chance would predict. Alterations and neurotransmission disturbance among critical anatomical networks, and impaired or aberrant plastic changes might predispose patients with TLE to mood disorders. Clinical and experimental studies of the effects of seizures on behavior and electrophysiological patterns may offer a model of how limbic seizures increase the vulnerability of TLE patients to precipitants of psychiatric symptoms.
Resumo:
In this minireview we describe the involvement of the atrial natriuretic peptide (ANP) in cardiovascular pathophysiology and exercise. The ANP has a broad homeostatic role and exerts complex effects on the cardio-circulatory hemodynamics, it is produced by the left atrium and has a key role in regulating sodium and water balance in mammals and humans. The dominant stimulus for its release is atrial wall tension, commonly caused by exercise. The ANP is involved in the process of lipolysis through a cGMP signaling pathway and, as a consequence, reducing blood pressure by decreasing the sensitivity of vascular smooth muscle to the action of vasoconstrictors and regulate fluid balance. The increase of this hormone is associated with better survival in patients with chronic heart failure (CHF). This minireview provides new evidence based on recent studies related to the beneficial effects of exercise in patients with cardiovascular disease, focusing on the ANP.
Resumo:
Panic disorder patients are vulnerable to recurrent panic attacks. Two neurochemical hypotheses have been proposed to explain this susceptibility. The first assumes that panic patients have deficient serotonergic inhibition of neurons localized in the dorsal periaqueductal gray matter of the midbrain that organize defensive reactions to cope with proximal threats and of sympathomotor control areas of the rostral ventrolateral medulla that generate most of the neurovegetative symptoms of the panic attack. The second suggests that endogenous opioids buffer normal subjects from the behavioral and physiological manifestations of the panic attack, and their deficit brings about heightened suffocation sensitivity and separation anxiety in panic patients, making them more vulnerable to panic attacks. Experimental results obtained in rats performing one-way escape in the elevated T-maze, an animal model of panic, indicate that the inhibitory action of serotonin on defense is connected with activation of endogenous opioids in the periaqueductal gray. This allows reconciliation of the serotonergic and opioidergic hypotheses of panic pathophysiology, the periaqueductal gray being the fulcrum of serotonin-opioid interaction.
Resumo:
Diffuse large B-Cell lymphoma is the most common subtype of non-Hodgkin lymphoma in the West. In Brazil, it is the fifth cause of cancer, with more than 55,000 cases and 26,000 deaths per year. At Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - HCFMUSP, diffuse large B-Cell lymphoma represents 49.7% of all non-Hodgkin lymphoma cases. Initially, the classification of non-Hodgkin lymphoma was based on morphology, but advances in immunology and molecular medicine allowed the introduction of a biological classification for these diseases. As for other cancers, non-Hodgkin lymphoma involves patterns of multi factorial pathogenesis with environmental factors, as well as genetic, occupational and dietary factors, contributing to its development. Multiple lesions involving molecular pathways of B-cell proliferation and differentiation may result in the activation of oncogenes such as the BCL2, BCL6,and MYC genes and the inactivation of tumor suppressor genes such as p53 and INK4, as well as other important transcription factors such as OCT-1 and OCT-2. A dramatic improvement in survival was seen after the recent introduction of the anti-CD20 monoclonal antibody. The association of this antibody to the cyclophosphamide, hydroxydaunorubicin, oncovin and prednisolone (CHOP) regimen has increased overall survival of diffuse large B-Cell lymphoma and follicular lymphoma patients by 20%. However, 50% of all diffuse large B-Cell lymphoma patients remain incurable, creating a demand for more research with new advances in treatment. Thus, it is important to know and understand the key factors and molecular pathways involved in the pathogenesis of diffuse large B-Cell lymphoma.
Resumo:
Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA.
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Patients with type 2 diabetes mellitus (T2DM) exhibit insulin resistance associated with obesity and inflammatory response, besides an increased level of oxidative DNA damage as a consequence of the hyperglycemic condition and the generation of reactive oxygen species (ROS). In order to provide information on the mechanisms involved in the pathophysiology of T2DM, we analyzed the transcriptional expression patterns exhibited by peripheral blood mononuclear cells (PBMCs) from patients with T2DM compared to non-diabetic subjects, by investigating several biological processes: inflammatory and immune responses, responses to oxidative stress and hypoxia, fatty acid processing, and DNA repair. PBMCs were obtained from 20 T2DM patients and eight non-diabetic subjects. Total RNA was hybridized to Agilent whole human genome 4x44K one-color oligo-microarray. Microarray data were analyzed using the GeneSpring GX 11.0 software (Agilent). We used BRB-ArrayTools software (gene set analysis - GSA) to investigate significant gene sets and the Genomica tool to study a possible influence of clinical features on gene expression profiles. We showed that PBMCs from T2DM patients presented significant changes in gene expression, exhibiting 1320 differentially expressed genes compared to the control group. A great number of genes were involved in biological processes implicated in the pathogenesis of T2DM. Among the genes with high fold-change values, the up-regulated ones were associated with fatty acid metabolism and protection against lipid-induced oxidative stress, while the down-regulated ones were implicated in the suppression of pro-inflammatory cytokines production and DNA repair. Moreover, we identified two significant signaling pathways: adipocytokine, related to insulin resistance; and ceramide, related to oxidative stress and induction of apoptosis. In addition, expression profiles were not influenced by patient features, such as age, gender, obesity, pre/post-menopause age, neuropathy, glycemia, and HbA(1c) percentage. Hence, by studying expression profiles of PBMCs, we provided quantitative and qualitative differences and similarities between T2DM patients and non-diabetic individuals, contributing with new perspectives for a better understanding of the disease. (C) 2012 Elsevier B.V. All rights reserved.
Resumo:
Background: Abnormal regulation of glycogen synthase kinase 3-beta (GSK3B) activity has been implicated in the pathophysiology of mood disorders. Many pharmacological agents, including antidepressants, can modulate GSK3B. The aim of the present study was to investigate the effect of short-and long-term sertraline treatment on the expression and phosphorylation of GSK3B in platelets of patients with late-life major depression. Methods: Thirty-nine unmedicated elderly adults with major depressive disorder (MOD) were initially included in this study. The comparison group comprised 18 age-matched, healthy individuals. The expression of total and Ser-9 phosphorylated GSK3B (pGSK3B) was determined by Enzyme Immunometric Assay (EIA) in platelets of patients and controls at baseline, and after 3 and 12 months of sertraline treatments for patients only. During this period, patients were continuously treated with therapeutic doses of sertraline. GSK3B activity was indirectly estimated by calculating the proportion of inactive (phosphorylated) forms (pGSK3B) in relation to the total expression of the enzyme (i.e.. GSK3B ratio). Results: Depressed patients had significantly higher levels of pGSK3B as compared to controls (p < 0.001). Within the MDD group, after 3 months of sertraline treatment no significant changes were observed in GSK3B expression and phosphorylation state, as compared to baseline levels. However, after 12 months of treatment we found a significant increase in the expression of total GSK3B (p = 0.05), in the absence of any significant changes in pGSK3B (p = 0.12), leading to a significant reduction in GSK3B ratio (p = 0.001). Conclusions: Our findings indicate that GSK3B expression was upregulated by the continuous treatment with sertraline, along with an increment in the proportion of active forms of the enzyme. This is compatible with an increase in overall GSK3B activity, which may have been induced by the long-term treatment of late-life depression with sertraline. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
Recent studies have implicated adiponectin and other adipocytokines in brain function, particularly in processes related to memory and cognition. Blood levels of adiponectin are reduced in patients with primary cognitive disorders, such as Alzheimer's disease and mild cognitive impairment, and in adult patients with major depression. The aim of the present study is to determine serum levels of adiponectin in a sample of elderly patients with major depressive disorder (MOD) as compared to healthy older adults, and to examine the correlations between adiponectin levels and parameters indicative of mood and cognitive state. We recruited fifty-one unmedicated outpatients with late-life depression (LLD) and 47 age-matched controls in this study. The diagnosis of MDD was made according to the DSM-IV criteria, and the severity of depressive episode was determined with the 21-item Hamilton Depression Scale (HORS). Cognitive state was ascertained with the Cambridge Cognitive Test (CAMCOG) and the Mini-Mental State Examination (MMSE). Serum concentrations of adiponectin were determined using a sandwich ELISA method. Serum levels of adiponectin were significantly reduced in individuals with LLD (F = p < 0.001). Adiponectin level remained significantly reduced in after controlling for BMI index, scores on the CAMCOG, MMSE and HDRS and educational level (p < 0.001). Adiponectin levels showed a negative correlation with HORS scores (r = -0.59, p < 0.001) and BMI index (r = -0.42, p < 0.001); and showed a positive correlation with CAMCOG (r = 0.34, p < 0.01) and MMSE scores (r = 0.20, p = 0.05). The availability of circulating adiponectin is reduced in older adults with major depression, with likely implications on cognitive and mood state. Additional studies are required to determine whether this abnormality pertains to the pathophysiology of geriatric depression per se, or is a consequence of the morbid state. (C) 2012 Elsevier Ltd. All rights reserved.
Resumo:
Inaccurate wiring and synaptic pathology appear to be major hallmarks of schizophrenia. A variety of gene products involved in synaptic neurotransmission and receptor signaling are differentially expressed in brains of schizophrenia patients. However, synaptic pathology may also develop by improper expression of intra- and extra-cellular structural elements weakening synaptic stability. Therefore, we have investigated transcription of these elements in the left superior temporal gyrus of 10 schizophrenia patients and 10 healthy controls by genome-wide microarrays (Illumina). Fourteen up-regulated and 22 downregulated genes encoding structural elements were chosen from the lists of differentially regulated genes for further qRT-PCR analysis. Almost all genes confirmed by this method were downregulated. Their gene products belonged to vesicle-associated proteins, that is, synaptotagmin 6 and syntaxin 12, to cytoskeletal proteins, like myosin 6, pleckstrin, or to proteins of the extracellular matrix, such as collagens, or laminin C3. Our results underline the pivotal roles of structural genes that control formation and stabilization of pre- and post-synaptic elements or influence axon guidance in schizophrenia. The glial origin of collagen or laminin highlights the close interrelationship between neurons and glial cells in establishment and maintenance of synaptic strength and plasticity. It is hypothesized that abnormal expression of these and related genes has a major impact on the pathophysiology of schizophrenia.
Resumo:
Immune thrombocytopenic purpura (ITP) is a common hematological disorder in the childhood, and it is one of the most common forms of autoimmune disease in pediatric patients. The ITP basis is a primary dysfunction of the immune system. This study aimed to analyze the genetic polymorphisms of the Fc gamma receptors IIA and IIIA. The genetic polymorphisms of the Fc receptors gamma IIA (131H/R) and gamma RIIIA (158V/F) were analyzed by polymerase chain reaction-restriction fragment length polymorphism technique. Odds ratio and 95% confidence interval were calculated by chi(2) test. Homozygous polymorphic genotype for the Fc gamma RIIIA was significantly more frequent among patients compared with controls (odds ratio = 0.27; 95% confidence interval, 0.09-0.80; P = 0.03). There was no statistical difference between the ITP group and the controls in the analysis of combinations of alleles of the high-affinity Fc receptor, but the ITP individuals with this combination had a lower duration of disease (P = 0.01). Genetic polymorphisms in immune system genes can be important for ITP pathogenesis and disease outcome.
Resumo:
Recent findings in the literature suggest a relation between histidine triad nucleotide-binding protein-1 (HINT1) and psychiatric disorders such as major depression, anxiety, and schizophrenia, although its physiological roles are not completely comprehended. Using Western blot, we compared HINT1 protein expression in the postmortem dorsolateral prefrontal cortex and thalamus of schizophrenia patients and healthy controls for contributing to elucidate the role of HINT1 in schizophrenia pathophysiology. HINT1 was found to be downregulated in the dorsolateral prefrontal cortex and upregulated in the thalamus. Our results combined to previous studies in human samples and preclinical models support the notion that HINT1 must be more explored as a potential target for psychiatric disorders.
Glucocorticoid and Estrogen Receptors Are Reduced in Mitochondria of Lung Epithelial Cells in Asthma
Resumo:
Mitochondrial glucocorticoid (mtGR) and estrogen (mtER) receptors participate in the coordination of the cell's energy requirement and in the mitochondrial oxidative phosphorylation enzyme (OXPHOS) biosynthesis, affecting reactive oxygen species (ROS) generation and induction of apoptosis. Although activation of mtGR and mtER is known to trigger anti-inflammatory signals, little information exists on the presence of these receptors in lung tissue and their role in respiratory physiology and disease. Using a mouse model of allergic airway inflammation disease and applying confocal microscopy, subcellular fractionation, and Western blot analysis we showed mitochondrial localization of GR alpha and ER beta in lung tissue. Allergic airway inflammation caused reduction in mtGR alpha, mtER beta, and OXPHOS enzyme biosynthesis in lung cells mitochondria and particularly in bronchial epithelial cells mitochondria, which was accompanied by decrease in lung mitochondrial mass and induction of apoptosis. Confirmation and validation of the reduction of the mitochondrial receptors in lung epithelial cells in human asthma was achieved by analyzing autopsies from fatal asthma cases. The presence of the mitochondrial GR alpha and ER beta in lung tissue cells and especially their reduction in bronchial epithelial cells during allergic airway inflammation suggests a crucial role of these receptors in the regulation of mitochondrial function in asthma, implicating their involvement in the pathophysiology of the disease.
Resumo:
Background: Kinins participate in the pathophysiology of obesity and type 2 diabetes by mechanisms which are not fully understood. Kinin B-1 receptor knockout mice (B-1(-/-)) are leaner and exhibit improved insulin sensitivity. Methodology/Principal Findings: Here we show that kinin B-1 receptors in adipocytes play a role in controlling whole body insulin action and glucose homeostasis. Adipocytes isolated from mouse white adipose tissue (WAT) constitutively express kinin B-1 receptors. In these cells, treatment with the B-1 receptor agonist des-Arg(9)-bradykinin improved insulin signaling, GLUT4 translocation, and glucose uptake. Adipocytes from B-1(-/-) mice showed reduced GLUT4 expression and impaired glucose uptake at both basal and insulin-stimulated states. To investigate the consequences of these phenomena to whole body metabolism, we generated mice where the expression of the kinin B-1 receptor was limited to cells of the adipose tissue (aP2-B-1/B-1(-/-)). Similarly to B-1(-/-) mice, aP2-B-1/B-1(-/-) mice were leaner than wild type controls. However, exclusive expression of the kinin B1 receptor in adipose tissue completely rescued the improved systemic insulin sensitivity phenotype of B-1(-/-) mice. Adipose tissue gene expression analysis also revealed that genes involved in insulin signaling were significantly affected by the presence of the kinin B-1 receptor in adipose tissue. In agreement, GLUT4 expression and glucose uptake were increased in fat tissue of aP2-B-1/B-1(-/-) when compared to B-1(-/-) mice. When subjected to high fat diet, aP2-B-1/B-1(-/-) mice gained more weight than B-1(-/-) littermates, becoming as obese as the wild types. Conclusions/Significance: Thus, kinin B-1 receptor participates in the modulation of insulin action in adipocytes, contributing to systemic insulin sensitivity and predisposition to obesity.
Resumo:
Background The aim of the present study was to investigate the efficacy and tolerability of acupuncture (AC), Tanacetum (TAN) or combined treatment on quality of life in women with chronic migraine (CM). Methods A total of 69 women volunteers were randomly divided into 3 groups: AC, acupuncture administered in 20 sessions over 10 weeks (n=22); TAN, at 150 mg/day (n=23); and AC+TAN (n=23). The primary outcome was Short-Form 36 (SF-36) quality of life assessment score. Secondary outcomes included the Migraine Disability Assessment (MIDAS) and visual analogue scale (VAS) score experienced after randomisation. Results AC+TAN was statistically significantly more effective than AC or TAN alone in overall health-related quality of life (SF-36; p<0.05), on MIDAS score (-35.1 (10.6) AC vs -24.8 (11.7) TAN vs -42.5 (9.8) AC+TAN; p<0.05) and in reducing the mean score of pain on VAS (-5.6 (2.4) AC vs -3.7 (2.1) TAN vs -6.4 (3.1) AC+TAN; p<0.05). Conclusions The present work shows an improvement of the quality of life and better analgesic effect of acupuncture combined with TAN treatment on migraine pain in women when compared with acupuncture or TAN alone.
Resumo:
Lithium salts have a well-established role in the treatment of major affective disorders. More recently, experimental and clinical studies have provided evidence that lithium may also exert neuroprotective effects. In animal and cell culture models, lithium has been shown to increase neuronal viability through a combination of mechanisms that includes the inhibition of apoptosis, regulation of autophagy, increased mitochondrial function, and synthesis of neurotrophic factors. In humans, lithium treatment has been associated with humoral and structural evidence of neuroprotection, such as increased expression of anti-apoptotic genes, inhibition of cellular oxidative stress, synthesis of brain-derived neurotrophic factor (BDNF), cortical thickening, increased grey matter density, and hippocampal enlargement. Recent studies addressing the inhibition of glycogen synthase kinase-3 beta (GSK3B) by lithium have further suggested the modification of biological cascades that pertain to the pathophysiology of Alzheimer's disease (AD). A recent placebo-controlled clinical trial in patients with amnestic mild cognitive impairment (MCI) showed that long-term lithium treatment may actually slow the progression of cognitive and functional deficits, and also attenuate Tau hyperphosphorylation in the MCI-AD continuum. Therefore, lithium treatment may yield disease-modifying effects in AD, both by the specific modification of its pathophysiology via inhibition of overactive GSK3B, and by the unspecific provision of neurotrophic and neuroprotective support. Although the clinical evidence available so far is promising, further experimentation and replication of the evidence in large scale clinical trials is still required to assess the benefit of lithium in the treatment or prevention of cognitive decline in the elderly.