939 resultados para consistent evidence
Resumo:
Recent theories of panic disorder propose an extensive involvement of limbic system structures, such as the hippocampus, in the pathophysiology of this condition. Despite this, no prior study has examined exclusively the hippocampal neurochemistry in this disorder. The current study used proton magnetic resonance spectroscopy imaging ((1)H-MRSI) to examine possible abnormalities in the hippocampus in panic disorder patients. Participants comprised 25 panic patients and 18 psychiatrically healthy controls. N-acetylaspartate (NAA, a putative marker of neuronal viability) and choline (Cho, involved in the synthesis and degradation of cell membranes) levels were quantified relative to creatine (Cr, which is thought to be relatively stable among individuals and in different metabolic condition) in both right and left hippocampi. Compared with controls, panic patients demonstrated significantly lower NAA/Cr in the left hippocampus. No other difference was detected. This result is consistent with previous neuroimaging findings of hippocampal alterations in panic and provides the first neurochemical evidence suggestive of involvement of this structure in the disorder. Moreover, lower left hippocampal NAA/Cr in panic disorder may possibly reflect neuronal loss and/or neuronal metabolic dysfunction, and could be related to a deficit in evaluating ambiguous cues. (C) 2010 Elsevier Ireland Ltd. All rights reserved.
Resumo:
There is a considerable interindividual variation in L-thyroxine [ 3,5,3`,5`-tetraiodo-l-thyronine (T(4))] dose required for thyrotropin (thyroid-stimulating hormone) suppression in patients with differentiated thyroid cancer. To investigate whether uridine diphosphate-glucuronosyl transferase 1A1 (UGT1A1)-mediated T(4) glucuronidation in liver affects T(4) dose, we genotyped 101 patients for the common UGT1A1-53(TA)(n) polymorphism and compared T(4) doses among patients having zero (5/6 and 6/6 genotypes), one (6/7 genotype), or two (7/7 and 7/8 genotypes) copies of the low-expression (TA) 7 and (TA) 8 alleles. A significant trend for decreasing T(4) dose with increasing number of copies of (TA)(7) and (TA)(8) (P = 0.037) and significant difference in T(4) dose across the UGT1A1-53(TA)(n) genotypes (P = 0.048) were observed, despite considerable overlap of T(4) doses among different genotypes. These results are consistent with reduced T(4) glucuronidation in patients with low-expression (TA) 7 and (TA) 8 alleles and provide the first evidence for association between UGT1A1-53(TA)(n) and T(4)-dose requirement for thyroid-stimulating hormone suppression in a natural clinical setting. Pharmacogenetics and Genomics 21: 341-343 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins. Pharmacogenetics and Genomics 2011, 21: 341-343
Resumo:
Pseudomyxoma peritonei (PMP) is a clinical condition initially thought to be related to ovarian mucinous tumors; however, immunohistochemistry and molecular biology techniques have convincingly made the link to appendiceal mucinous neoplasms, resulting in changes in histologic and clinical approaches. The objective of this study was to compare the immunohistochemical profile of ovarian tumors associated with PMP and intestinal mucinous ovarian neoplasms without PMP. The study was retrospective and included 28 intestinal ovarian mucinous tumors selected from the files of the Division of Surgical Pathology of the University of Sao Paulo Medical School, from 1996 to 2005. Seven cases were associated with PMP of disseminated peritoneal adenomucinosis-type and all presented borderline histology. Immunohistochemical staining for mucin genes products (MUC1, MUC2, MUC5AC, and MUC6), CK7, CK20, CA19.9, and CA125 were performed in tissue microarrays. Of note, we detected differences in the expression of MUC2 and CK20 between cases with and without PMP. Comparisons of borderline histology with that of benign/malignant tumors also revealed differences in MUC2 and CK20. Our results confirm that there is a distinct profile of intestinal ovarian tumors associated with pseudomyxoma, particularly with respect to the expression of the gel-forming mucin MUC2. The profile of borderline tumors, even in cases without PMP, was distinct from that of other primary mucinous tumors of the intestinal type, suggesting that borderline histology may represent a secondary tumor or a less aggressive variant of PMP. An appendiceal origin seems the most probable for this group of neoplasias.
Resumo:
Aims: To evaluate the role of hormonal contraceptives as a risk factor of high-risk human papillomavirus (HR-HPV), cervical intraepithelial lesions (CIN) and cervical cancer in our multi-center population-based LAMS (Latin American Screening) study. Methods: A cohort study with >12,000 women from Brazil and Argentina using logistic regression to analyze the covariates of hormonal contraception (HOC - oral, injections, patches, implants, vaginal ring and progesterone intrauterine system) use followed by multivariate modeling for predictors of HR-HPV and CIN2+. Results: HR-HPV infection was a consistent risk factor of high-grade CIN in all three groups of women. The length of HOC use was not significantly related to high-grade squamous intraepithelial lesions (HSIL)+ Pap (p = 0.069), LSIL+ Pap (p = 0.781) or ASCUS+ (p = 0.231). The same was true with the length of HOC use and histology CIN3+ (p = 0.115) and CIN2+ (p = 0.515). Frequently, HOC users have previously shown more HPV-related lesions, as well as lower HPV prevalence if they were current smokers. But HOC use and time of usage were not independent risk factors of either HR-HPV infection or high-grade CIN using multiple logistic regressions. Conclusions: No evidence was found for an association between the use of HOC with an increased risk for HR-HPV infection or high-grade CIN in this cohort. Copyright (C) 2010 S. Karger AG, Basel
Resumo:
Well-differentiated liposarcoma (WDLS) is one of the most common malignant mesenchymal tumors and dedifferentiated liposarcoma (DDLS) is a malignant tumor consisting of both WDLS and a transformed nonlipogenic sarcomatous component. Cytogenetically, WDLS is characterized by the presence of ring or giant rod chromosomes containing several amplified genes, including MDM2, TSPAN31 CDK4, and others mainly derived from chromosome bands 12q13-15. However, the 12q13-15 amplicon is large and discontinuous. The focus of this study was to identify novel critical genes that are consistently amplified in primary (nonrecurrent) WDLS and with potential relevance for future targeted therapy. Using a high-resolution (5.0 kb) ""single nucleotide polymorphism""/copy number variation microarray to screen the whole genome in a series of primary WDLS, two consistently amplified areas were found on chromosome 12: one region containing the MDM2 and CPM genes, and another region containing the FRS2 gene. Based on these findings, we further validated FRS2 amplification in both WDLS and DDLS. Fluorescence in situ hybridization confirmed FRS2 amplification in all WDLS and DDLS tested (n = 57). Real time PCR showed FRS2 mRNA transcriptional upregulation in WDLS (n = 19) and DDLS (n = 13) but not in lipoma (n = 5) and normal fat (n = 9). Immunoblotting revealed high expression levels of phospho-FRS2 at 1436 and slightly overexpression of total FRS2 protein in liposarcoma but not in normal fat or preadipocytes. Considering the critical role of FRS2 in mediating fibroblast growth factor receptor signaling, our findings indicate that FRS2 signaling should be further investigated as a potential therapeutic target for liposarcoma. (C) 2011 Wiley-Liss, Inc.
Resumo:
Background: Homeopathy is based on the principle of similitude (similia similibus curentur) using medicines that cause effects similar to the symptoms of disease in order to stimulate the reaction of the organism. Such vital, homeostatic or paradoxical reaction of the organism is closely related to rebound effect of drugs. Method: Review of the literature concerning the rebound effects of drugs used to suppress gastric acidity, particularly proton pump inhibitors (PPIs). Results: The mechanism of action of these effects is discussed. Rebound in terms of clinical symptoms and physiological effects occur in about 40% of people taking PPIs, their timing depends on the half-life of the drug and the adaptation period of the physiological mechanisms involved. The wide use of PPIs may be linked to the rising incidence of carcinoid tumours. Conclusions: These findings support Hahnemann`s concept of secondary action of drugs. We are developing a homeopathic materia medica and repertory of modern drugs on the basis of reported rebound effects. Homeopathy (2011) 100, 148-156.
Resumo:
Background: In view of conflicting neuroimaging results regarding autonomic-specific activity within the anterior cingulate cortex (ACC), we investigated autonomic responses to direct brain stimulation during sterecitactic limbic surgery. Methods: Skin conductance activity and accelerative heart rate responses to multi-voltage stimulation of the ACC (n = 7) and paralimbic subcauclate (n = 5) regions were recorded during bilateral anterior cingulotomy and bilateral subcauclate tractotomy (in patients that had previously received an adequate lesion in the ACC), respectively. Results: Stimulations in both groups were accompanied by increased autonomic arousal. Skin conductance activity was significantly increased during ACC stimulations compared with paralimbic targets at 2 V (2.34 +/- .68 [score in microSiemens +/- SE] vs. .34 +/- .09, p = .013) and 3 V (3.52 +/- .86 vs. 1.12 +/- .37, p = .036), exhibiting a strong ""voltage-response"" relationship between stimulus magnitude and response amplitude (difference from 1 to 3 V = 1.15 +/- .90 vs. 3.52 +/- .86, p = .041). Heart rate response was less indicative of between-group differences. Conclusions: This is the first study of its kind aiming at seeking novel insights into the mechanisms responsible for central autonomic modulation. It supports a concept that interregional interactions account for the coordination of autonomic arousal.
Resumo:
Papaya (Carica papaya) is a climacteric fruit that undergoes dramatic pulp softening. Fruits sampled at three different conditions (natural ripening or after exposition to ethylene or 1-methylcyclopropene) were used for the isolation of cell wall polymers to find changes in their degradation pattern. Polymers were separated according to their solubility in water, CDTA, and 4 M alkali, and their monosaccharide compositions were determined. Water-soluble polymers were further characterized, and their increased yields in control and ethylene-treated fruit, in contrast to those that were treated with 1-MCP, indicated a strong association between fruit softening and changes in the cell wall water-soluble polysaccharide fraction. The results indicate that the extensive softening in the pulp of ripening papayas is a consequence of solubilization of large molecular mass galacturonans from the pectin fraction of the cell wall. This process seems to be dependent on the levels of ethylene, and it is likely that the releasing of galacturonan chains results from an endo acting polygalacturonase.
Resumo:
Background: Samuel Hahnemann noticed that palliative treatments for the symptoms of chronic diseases, after an initial improvement, provoked symptoms similar but stronger symptoms to those initially suppressed. He regarded this as a consequence of the vital reaction of the organism: an automatic and instinctive capacity to return to the initial health condition altered by medicines. Using this homeostatic conception of the organism as a treatment rationale, Hahnemann proposed the therapy of similarity, administering to the patients medicines capable of causing, in healthy individuals, similar symptoms to the natural disease. Based on experimental observations, he proposed that the primary action of the drug was followed by the secondary and opposite action of the organism, inaugurating homeopathic pharmacology, and alerting to the harmful consequences of palliative medicines in susceptible individuals. Such liatrogenic events can be observed in contemporary medicine, after the withdrawal of modern enantiopathic medicines, according to the study of the rebound effect or paradoxical reaction of the organism. Method. This study reviews the recent studies which describe suicidallity after the suspension or discontinuation of second generation antidepressants according to the hypothesis of the paradoxical reaction of the organism. Conclusions: Rebound and withdrawal effects, including suicidality occur with antidepressant drugs. They are relatively rare but more intense than the primary action of the drug. The probability of such effects is influenced by patient factors including age and diagnosis, and drug factors including half-life. Homeopathy (2009) 98, 114-121.
Resumo:
The mechanisms of the systemic response associated with talc-induced pleurodesis are poorly understood. The aim of this study was to assess the acute inflammatory response and migration of talc of small. size particles injected in the pleural space. Rabbits were injected intrapleurally with talc solution containing small. or mixed particles and blood and pleural fluid samples were collected after 6, 24 or 48 h and assayed for leukocytes, neutrophils, lactate dehydrogenase, IL-8, VEGF, and TGF-beta. The lungs, spleen, liver and kidneys were assessed to study deposit of talc particles. Both types of talc produced an acute serum inflammatory response, more pronounced in the small particles group. Pleural fluid IL-8 and VEGF levels were higher in the small particle talc group. Correlation between pleural VEFG and TGF-beta levels was observed for both groups. Although talc particles were demonstrated in the organs of both groups, they were more pronounced in the small talc group. In conclusion, intrapleural injection of talc of small size particles produced a more pronounced acute systemic response and a greater deposition in organs than talc of mixed particles. (C) 2008 Elsevier Ltd. All rights reserved.
Resumo:
Previous studies have suggested that bipolar disorder (BD) is associated with alterations in neuronal plasticity, but the effects of the progression of illness on brain anatomy have been poorly investigated. We studied the correlation between length of illness, age, age at onset, and the number of previous episodes and total brain, total gray, and total white matter volumes in BD, unipolar (UP) and healthy control (HC) subjects. Thirty-six BD, 31 UP and 55 HCs underwent a 1.5 T brain magnetic resonance imaging scan, and gray and white matter volumes were manually traced blinded to the subjects` diagnosis. Partial correlation analysis showed that length of illness was inversely correlated with total gray matter volume after adjusting for total intracranial volume in BD (r(p)=-0.51; p=0.003) but not in UP subjects (r(p)=-0.23; p=0.21). Age at illness onset and the number of previous episodes were not significantly correlated with gray matter volumes in BD or UP subjects. No significant correlation with total white matter volume was observed. These results suggest that the progression of illness may be associated with abnormal cellular plasticity. Prospective longitudinal studies are necessary to elucidate the long-term effects of illness progression on brain structure in major mood disorders. (C) 2008 Published by Elsevier B.V.
Resumo:
Nematode parasites from the genus Strongyloides spp. are important pathogens of the intestinal mucosa of animals and humans. Their complex life cycles involve alternating developmental adaptations between larvae stages and the adult parthenogenetic female. Here, we report, primarily through homology-based searching, the existence of the major components of the ubiquitin-proteasome system in this genus, using the available EST data from S. ratti, S. stercoralis, and Parastrongyloides trichosuri. In this study, S. venezuelensis was used as our model organism for detection of proteasome activity and ubiquitinated substrates in cytosolic preparations from the L3 larvae and the adult female. Marked differences in proteasome capabilities were found when these two stages were compared. A preference for degradation of chymotryptic synthetic peptides was found in both stages with the adult exhibiting a higher rate of hydrolysis compared to the larvae. Due to the high evolutionary conservation of proteasome alpha subunits, an anti-human proteasome antibody was able to recognize proteasome subunits in these preparations by Western blotting, supporting the proposal that the activity of the ubiqutin-proteasome system is developmentally regulated in this nematode.