Browsing by Author "Leite, J"
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- Brain activation of the defensive and appetitive survival systems in obsessive compulsive disorderPublication . Gonçalves, OF; Soares, JM; Carvalho, S; Leite, J; Ganho, A; Fernandes-Gonçalves, A; Frank, B; Pocinho, F; Relvas, J; Carracedo, A; Sampaio, ASeveral studies have shown that basic emotions are responsible for a significant enhancement of early visual processes and increased activation in visual processing brain regions. It may be possible that the cognitive uncertainty and repeated behavioral checking evident in Obsessive Compulsive Disorder (OCD) is due to the existence of abnormalities in basic survival circuits, particularly those associated with the visual processing of the physical characteristics of emotional-laden stimuli. The objective of the present study was to test if patients with OCD show evidence of altered basic survival circuits, particularly those associated with the visual processing of the physical characteristics of emotional stimuli. Fifteen patients with OCD and 12 healthy controls underwent functional magnetic resonance imaging acquisition while being exposed to emotional pictures, with different levels of arousal, intended to trigger the defensive and appetitive basic survival circuits. Overall, the present results seem to indicate dissociation in the activity of the defense and appetitive survival systems in OCD. Results suggest that the clinical group reacts to basic threat with a strong activation of the defensive system mobilizing widespread brain networks (i.e., frontal, temporal, occipital-parietal, and subcortical nucleus) and blocking the activation of the appetitive system when facing positive emotional triggers from the initial stages of visual processing (i.e., superior occipital gyrus).
- Carcinoma pancreático de células gigantes de tipo osteoclásticoPublication . Pimentel, A; Leitão, S; Dias, N; Cipriano, MA; Leite, J; Santos, R; Nascimento-Costa, JMInitially described 40 years ago (Rosai), the undifferentiated osteoclastic-type giant cell carcinoma (IOGCC) is a variant of ductal adenocarcinoma and accounts for less than 1% of exocrine pancreatic tumors. Its extreme rarity, with consequent existence of few reports and clinical experience, leads to the arousal of doubts with regard to its histogenesis, types of approach and therapeutical attitudes. It is important to note that in Portugal no similar case is registered in medical literature. A 61 year old patient admitted to the Internal Medicine Ward 3 at Coimbra University Hospital presents with a volumous intra-abdominal mass in the left hypochondrium and microcytic anemia. During the investigation, a pancreatic neoplasm was identified, and the patient was submitted to surgical resection, the anatomo-pathological study of the tumor having revealed IOGCC. The particularities of the case, current available therapeutical options and its evolution are discussed, as well as a revision of the existing literature.
- Cerebral Venous Thrombosis as Rare Presentation of Herpes Simplex Virus EncephalitisPublication . Leite, J; Ribeiro, A; Gonçalves, D; Sargento-Freitas, J; Trindade, L; Duque, VHerpes simplex virus 1 is a prevalent neurotropic pathogen that infects and establishes latency in peripheral sensory neurons. It can migrate into the central nervous system and cause encephalitis. The association between herpes simplex virus encephalitis and cerebral venous thrombosis is rare, with a very limited number of case reports described in the literature, despite the recognized thrombogenic effects of the virus. A 44-year-old man was brought to the emergency department with generalized tonic-clonic seizures requiring sedation and ventilation to control it. Initial brain computed tomography revealed cortical and subcortical edema on the left frontal lobe, and a subsequent contrast-enhanced exam showed absence of venous flow over the anterior half of the superior sagittal sinus. Cerebrospinal fluid polymerase chain reaction was positive for herpes simplex virus type 1, and the patient was started on acyclovir and anticoagulation, with clinical improvement. Acyclovir administration was maintained for 14 days and oral anticoagulation for one year, with no recurrence of thrombotic events or other complications. A well-timed treatment has a validated prognostic impact on herpes simplex encephalitis, making early recognition of its clinical aspects of main importance.
- Germline MUTYH (MYH) mutations in Portuguese individuals with multiple colorectal adenomasPublication . Isidro, G; Laranjeira, F; Pires, A; Leite, J; Regateiro, FJ; Castro e Sousa, F; Soares, J; Castro, C; Giria, J; Brito, MJ; Medeira, A; Teixeira, R; Morna, H; Gaspar, I; Marinho, C; Jorge, R; Brehm, A; Ramos, JS; Boavida, MGGerminal mutations in the base excision repair (BER) gene MUTYH (MYH) have recently been described in association with predisposition to multiple colorectal adenomas and cancer. In contrast to the classic dominant condition of familial adenomatous polyposis (FAP) due to germinal mutations in the APC gene, the MYH polyposis is an autosomal recessive disease. The identification of individuals affected by MYH polyposis brings new and important implications for the diagnostic, screening, genetic counseling, follow up and therapeutic options in these patients. In this study, screening for germinal mutations in the MYH gene was performed in 53 Portuguese individuals with multiple colorectal adenomas or classic adenomatous polyposis, in whom no mutation had been identified in the APC gene. The results revealed the presence of biallelic germline MYH mutations in 21 patients. In addition, we here report 3 mutations (c.340T>C [p.Y114H]; c.503G>A [p.R168H]; and c.1186_1187insGG [p.E396fsX437]) which, to our knowledge, have not been previously described
- Obsessive Compulsive Disorder as a functional interhemispheric imbalance at the thalamic levelPublication . Gonçalves, OF; Carvalho, S; Leite, J; Pocinho, F; Relvas, J; Fregni, FObsessive Compulsive Disorder (OCD) involves failures in two main inhibitory processes, namely cognitive (obsessions) and behavioral (compulsions). Recent research has supported two cortical-subcortical pathways on OCD pathogenesis: (a) the frontostriatal loop (dorsolateral-caudate-striatum-thalamus) responsible for impairments of behavioral inhibition; (b) the orbitofrontal loop (orbitofrontal, medial prefrontal and cingulate) responsible for impairments with cognitive inhibitory processes. These failures in both cognitive and motor inhibitory systems may mediate several neuropsychological deficits in these patients, namely memory, attention, planning and decision making. But are those deficits related to specific hemispheric effects, namely functional imbalance between hemispheres? In this article we hypothesize that: (1) OCD patients have an inter-hemispheric functional imbalance, probably due to inadequate filtering at the thalamic level; (2) the restoration of inter-hemispheric balance, will be correlative to symptomatic improvement.
- Total neoadjuvant therapy: A new standard of care for locally advanced rectal cancer?Publication . Leite, J; Martins, SDelivering chemotherapy before surgery is a newer treatment approach called total neoadjuvant therapy (TNT), and the National Comprehensive Cancer Network guidelines recommend it for locally advanced rectal cancer (LARC) with cT3 / cN+ / cT4, in contrast with the European Society for Medical Oncology guidelines, in which most rectal cancers can be treated with surgery alone if good quality mesorectal resection is assured. Neoadjuvant or adjuvant treatments are reserved for patients with high-risk tumours, including cT3c/d or cT4, or that threaten the mesorectal fascia. The favourable outcomes in the RAPIDO trial for high-risk rectal cancers with a lower incidence of distant metastasis in the TNT group were observed but with an unexpected increase in the local recurrence with more extended follow-up. This suggests early surgery for nonresponding tumours. The TNT approach was also evaluated in the OPRA trial with long-course chemoradiotherapy and induction versus consolidation chemotherapy. Half the patients presented complete clinical responses and were enrolled in the watch-and-wait (WW) approach. Given the high number of trials and guidelines in this subject, the multidisciplinary team's decision-making process in rectal cancer management is complex. Looking at the actual data, it was concluded that TNT is not for all patients with LARC and is an option if organ preservation is a priority, although with a high regrowth rate in a WW strategy and increasing risk of distant metastasis, questioning the deleterious effect of deferral of surgery.
- Tratamento dos Tumores Desmóides Intra-Abdominais associados à Polipose Adenomatosa FamiliarPublication . Martins, SB; Leite, J; Oliveira, AS; Sá, A; Castro e Sousa, F
- Usefulness of Perfusion CT to Assess Response to Neoadjuvant Combined Chemoradiotherapy in Patients with Locally Advanced Rectal CancerPublication . Curvo-Semedo, L; Portilha, A; Ruivo, C; Borrego, M; Leite, J; Caseiro-Alves, FRATIONALE AND OBJECTIVES: To prospectively evaluate perfusion computed tomography (CT) for assessment of changes in tumor vascularity after chemoradiation therapy (CRT) in locally advanced rectal cancer and to analyze the correlation between baseline perfusion parameters and tumor response. MATERIALS AND METHODS: Twenty patients with rectal cancer underwent baseline perfusion CT before CRT, and in 11 an examination after CRT was also performed. For each tumor, blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability-surface area product (PS) were quantified. The Mann-Whitney U test compared baseline perfusion parameters of responders and nonresponders and pre- and post-CRT measurements were compared by the Wilcoxon signed-rank test (P < .05 statistically significant for both tests). RESULTS: Baseline BF was significantly lower (P = .013) and MTT was significantly higher (P = .006) in responders. Both were able to discriminate responders from nonresponders with a sensitivity of 80% and 100% and a specificity of 73.3% and 86.7%, respectively, for BF and MTT. Baseline BV and PS were not significantly different in responders and nonresponders. Perfusion parameters changed significantly in post-CRT scans compared to baseline: BF (P = .003), BV (P = .003), and PS (P = .008) decreased, whereas MTT increased (P = .006). CONCLUSION: Baseline BF and MTT can discriminate patients with a favorable response from those that fail to respond to CRT, potentially selecting high-risk patients with resistant tumors that may benefit from an aggressive preoperative treatment approach.