RESUMO
Intramedullary dorsal dermoid cysts are rare benign tumors, arising from the nests of embryonic ectoderm, which get buried or trapped under the lines of fusion of the ectodermal folds in the developing embryo. We present a rare case of intramedullary dermoid cyst in a 30-year-old asymptomatic female, who presented with paraplegia and ataxia. Magnetic resonance imaging was suggestive of neoplastic intramedullary mass. Intraoperatively, findings were suspicious of tuberculosis, but on final histopathological evaluation, the final and definitive diagnosis of intramedullary dermoid cyst was rendered. The postoperative phase was uneventful.
RESUMO
A 50-year-old female presented with a history of seizures, headache, nausea, and vomiting. On imaging, parafalcine meningioma with mass effect features was rendered. She underwent right frontal tumor excision and craniotomy. Pathological examination showed a tumor composed of syncytial aggregates of round to plump fusiform cells forming whorls around prominent branching congested vessels. The tumorous cells expressed α-smooth actin and heavy-chain caldesmon and were negative for epithelial membrane antigen, protein S100, HMB45, CD34, calponin, and desmin, thus providing the final diagnosis of intracranial myopericytoma. The rarity of this benign tumor at an extremely rare location prompted this study. As preoperative radiological investigations are nonspecific in such cases, a detailed and comprehensive pathological examination is mandatory to come to a definitive diagnosis.
RESUMO
Autoantibodies to leucine-rich glioma-inactivated protein 1 (LGI-1) are associated with inflammation of the limbic system. Faciobrachial dystonic seizures are pathognomonic for LGI1-antibiodies and their treatment with immunotherapy is effective in seizure control with a potential to prevent cognitive decline. We report a 57-year-old man who presented to the emergency department with recurrent seizures, visual hallucinations and severe memory impairment over a seven-week period; he reported a background of alcohol excess. Initial investigations revealed hyponatremia, indicating syndrome of inappropriate anti-diuretic hormone secretion. Magnetic resonance imaging of the brain revealed bilateral asymmetrical high-T2 and low-T1 signal in the medial temporal lobes. Serum immunofluorescence assay tested positive for LGI-1 antibody. Patient responded to treatment with levetiracetam, intravenous methylprednisolone and five plasma exchange sessions. Patient remains on a maintenance dose of prednisolone and azathioprine. It is imperative that clinicians recognize signs of autoimmune encephalitis in order to curb long-term sequelae and improve clinical outcomes.
RESUMO
Despite the global medical needs associated with Staphylococcus aureus infections, no licensed vaccines are currently available. We identified and characterized a protein annotated as an epidermin leader peptide processing serine protease (EpiP), as a novel S. aureus vaccine candidate. In addition, we determined the structure of the recombinant protein (rEpiP) by X-ray crystallography. The crystal structure revealed that rEpiP was cleaved somewhere between residues 95 and 100, and we found that the cleavage occurs through an autocatalytic intramolecular mechanism. The protein expressed by S. aureus cells also appeared to undergo a similar processing event. To determine whether the protein acts as a serine protease, we mutated the hypothesized catalytic serine 393 residue to alanine, generating rEpiP-S393A. The crystal structure of this mutant protein showed that the polypeptide chain was not cleaved and was not interacting stably with the active site. Indeed, rEpiP-S393A was shown to be impaired in its protease activity. Mice vaccinated with rEpiP were protected from S. aureus infection (34% survival, P=0.0054). Moreover, the protective efficacy generated by rEpiP and rEpiP-S393A was comparable, implying that the noncleaving mutant could be used for vaccination purposes.