Role of Rab27 in synaptic transmission at the squid giant synapse

Small GTPase Rab is a member of a large family of Ras-related proteins, highly conserved in eukaryotic cells, and thought to regulate specific type(s) and/or specific step(s) in intracellular membrane trafficking. Given our interest in synaptic transmission, we addressed the possibility that Rab27 (a close isoform of Rab3) could be involved in cytosolic synaptic vesicle mobilization. Indeed, preterminal injection of a specific antibody against squid Rab27 (anti-sqRab27 antibody) combined with confocal microscopy demonstrated that Rab27 is present on squid synaptic vesicles. Electrophysiological study of injected synapses showed that the anti-sqRab27 antibody inhibited synaptic release in a stimulation-dependent manner without affecting presynaptic action potentials or inward Ca2+ current. This result was confirmed in in vitro synaptosomes by using total internal reflection fluorescence microscopy. Thus, synaptosomal Ca2+-stimulated release of FM1-43 dye was greatly impaired by intraterminal anti-sqRab27 antibody. Ultrastructural analysis of the injected giant preterminal further showed a reduced number of docked synaptic vesicles and an increase in nondocked vesicular profiles distant from the active zone. These results, taken together, indicate that Rab27 is primarily involved in the maturation of recycled vesicles and/or their transport to the presynaptic active zone in the squid giant synapse.

Giant prolapsed submucous leiomyoma: a surgical challenge for gynecologists

We present a case of a 45-year-old woman who presented with irregular vaginal bleeding and menorrhagia for two months, with an episode of massive bleeding initiating 24 hours before with hemodynamic shock. Vaginal inspection showed a soft, rounded, friable mass in vaginal introitus. After hospitalization, blood transfusion and hydration, she was submitted to vaginal myomectomy with the withdrawal of a 12-cm white, solid, huge, pedunculated, leiomyoma; however, hysterectomy was performed due to persistent uterine bleeding. The postoperation period had no complications. Macroscopy showed a retraction of the myoma pedicle. Gynecologists should prioritize clamping of a pedicle before surgery, reducing its size if the tumor is large.

Giant right coronary artery aneurysm presenting as a paracardiac mass

Coronary artery aneurysms, commonly atherosclerotic, are usually asymptomatic and can be diagnosed incidentally during investigation for ischemic heart disease or on autopsy. An asymptomatic giant right coronary artery aneurysm presenting as a paracardiac mass discovered on autopsy is reported here. Even though there was great concern due to its large size, complex atherosclerotic lesions, and potential obstruction of blood flow, it had no direct link to the cause of death. We also review the literature on giant right coronary artery aneurysms exceeding 5 cm in the last 10 years. (C) 2008 Elsevier Inc. All rights reserved.

Magnetic Resonance Angiography in Extracranial Giant Cell Arteritis

Background: Noninvasive diagnosis of giant cell arteritis (GCA) remains challenging, particularly with regard to evaluation of extracranial arterial disease. Objectives: The objective of the study was to retrospectively review extracranial involvement in patients with GCA and/or polymyalgia rheumatica (PMR), evaluated with magnetic resonance imaging (MRI), especially 3-dimensional contrast-enhanced magnetic resonance angiography images of the aortic arch and its branches. Methods: Clinical information, biopsy status, and MRI examinations of 28 patients with GCA/PMR were reviewed. Patient images were mixed randomly with 20 normal control images and were independently reviewed by 2 radiologists. Interobserver agreement for detection of arterial stenosis was determined by the k coefficient. Results: Both readers described vascular alterations in keeping with extracranial GCA in 19 of 28 patients (67%) with good interobserver agreement (k = 0.73) and with even higher agreement on diagnosing nonocclusive versus occlusive disease (k = 1.00). The most common lesions were bilateral axillary stenosis or obstructions, observed by both readers in 8 patients (28%). Among the 19 patients with magnetic resonance angiography lesions in the subclavian/axillary arteries, 12 (75%) had biopsy-proven GCA, but only 5 (41%) of these patients had clinical features of large artery disease. Conclusions: In our series review, MRI could provide accurate information on involvement of the aortic arch and its branches in extracranial GCA, depicting different degrees of stenosis. Our analysis also illustrates that occult large artery vasculitis should be considered in patients without biopsy-proven GCA, patients with classic GCA but without clinical signs of large artery disease, and in patients initially diagnosed as having PMR.

Giant Perineal Leiomyoma Incidentally Manifested at a Recent Episiotomy Site: Case Report

Benign leiomyomas are common soft tumors, arising especially in the female genital tract; unlike uterine leiomyomas, they rarely occur in perineal regions. They can develop wherever smooth muscle is present. Herein is reported the case of a large perineal leiomyoma in a 36-year-old woman who noted a palpable mass close to the rectum 1 year after she had delivered vaginally, in the same region of as a mediolateral episiotomy. Complete surgical excision was performed. Histopathologic findings were compatible with benign leiomyoma. At postoperative follow-up, no signs of anal dysfunction were noted. There was no pathologic correlation between formation of the leiomyoma and the episiotomy despite a possible association between the presence of fibrosis and development of leiomyomas, which was found during a literature review. Microarray analysis will be necessary to elucidate this hypothesis. Journal of Minimally Invasive Gynecology (2011) 18, 267-269 (C) 2011 AAGL. All rights reserved.

Tagging Giant Otters (Pteronura brasiliensis) (Carnivora, Mustelidae) for radio-telemetry studies

Memphis Zoo, U.S. Forest Service, Conselho Nacional de Desenvolvimento Cientifico e Tecnologico CNPq, Earthwatch Institute