Intestinal intussusception : a presentation of Crohn’s disease

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Infecção do sistema nervoso central : os achados de imagem sugestivos de fungo como causa

Fungal infections of the central nervous system (CNS) are rare. However, because of the increase in the number of immunocompromised individuals, they have been gaining prominence in the differential diagnosis of CNS infections. Imaging techniques are sensitive for detecting and localizing an abnormality, in many cases allowing the origin of a lesion to be categorized as infectious, inflammatory, neoplastic, or vascular. This essay illustrates the magnetic resonance imaging and computed tomography findings of the most common fungal infections of the CNS, based on the experience of the Radiology Department of the Hospital de Clínicas de Porto Alegre, in the city of Porto Alegre, RS, Brazil.As infecções fúngicas do sistema nervoso central (SNC) são raras, entretanto, com o aumento no número de indivíduos imunocomprometidos elas têm ganhado destaque no diagnóstico diferencial de infecções no SNC. As atuais técnicas de imagem são sensíveis para detectar uma anormalidade, localizá-la, e em muitos casos categorizar a lesão como de origem infecciosa e/ou inflamatória, neoplásica ou vascular. Este ensaio ilustra os achados de ressonância magnética e tomografia computadorizada mais comuns nas infecções fúngicas do SNC baseadas na experiência do Serviço de Radiologia do Hospital de Clínicas de Porto Alegre

The molar tooth sign and the bat wing appearance in Joubert syndrome

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Magnetic resonance imaging findings of the posterior fossa in 47 patients with mucopolysaccharidoses : a cross-sectional analysis

Background: Mucopolysaccharidoses (MPS) is a group of hereditary multisystemic lysosomal disorders. Most neuroimaging studies in MPS have focused on the supratentorial compartment and craniocervical junction abnormalities, and data regarding posterior fossa findings are scarce in the literature. Thus, our purpose is to describe posterior fossa findings on magnetic resonance imaging (MRI) of MPS patients. Methods: We reviewed routine MRI scans of MPS patients being followed up at our institution (types I, II, III, IV, and VI), focusing on posterior fossa structures. Results: Forty-seven MPS patients were included. MRI-visible perivascular spaces were commonly found in the midbrain and adjacent to the dentate nuclei (85% and 55% of patients, respectively). White-matter lesion was not identified in most cases. Its most frequent localizations were in the pons and cerebellum (34% and 30% of patients, respectively). Enlargement of cerebrospinal fluid (CSF) spaces in the posterior fossa was present in 55% of individuals and was more frequent in neuronopathic patients (73% vs 40%; P = .02). Cerebellar volume was classified as normal, apparent macrocerebellum, atrophic, and hypoplastic in 38%, 38%, 21%, and 3% of patients, respectively. A depression of the posterior fossa floor in the midline sagittal plane was found in 22 patients (47%), which was statistical significantly associated with enlargement of CSF spaces (P = .02) and with apparent macrocerebellum (P = .03). Conclusion: The present study compiled the main posterior fossa findings in MPS patients. Classically described in the supratentorial compartment, MRI-visible perivascular spaces, white matter lesions, and enlarged perivascular spaces were also found in the posterior fossa. However, atrophy, which commonly affects cerebral hemispheres, was not the most frequent cerebellar morphology found in our study. Moreover, potential findings for future research were described

The Presence–Absence Situation and Its Impact on the Assemblage Structure and Interspecific Relations of Pronophilina Butterflies in the Venezuelan Andes (Lepidoptera: Nymphalidae)

Assemblage structure and altitudinal patterns of Pronophilina, a species-rich group of Andean butterflies, are compared in El Baho and Monte Zerpa, two closely situated and ecologically similar Andean localities. Their faunas differ only by the absence of Pedaliodes ornata Grose-Smith in El Baho. There are, however, important structural differences between the two Pronophilina assemblages. Whereas there are five co-dominant species in Monte Zerpa, including P. ornata, Pedaliodes minabilis Pyrcz is the only dominant with more than half of all the individuals in the sample in El Baho. The absence of P. ornata in El Baho is investigated from historical, geographic, and ecological perspectives exploring the factors responsible for its possible extinction including climate change, mass dying out of host plants, and competitive exclusion. Although competitive exclusion between P. ornata and P. minabilis is a plausible mechanism, considered that their ecological niches overlap, which suggests a limiting influence on each other’s populations, the object of competition was not identified, and the reason of the absence of P. ornata in El Baho could not be established. The role of spatial interference related to imperfect sexual behavioral isolation is evaluated in maintaining the parapatric altitudinal distributions of three pairs of phenotypically similar and related species of Pedaliodes, Corades, and Lymanopoda