43 research outputs found
In Stent Restenosis Predictors after Carotid Artery Stenting
Purpose. The long-term efficacy of carotid artery stenting is debated. Predictors of stent restenosis are not fully investigated. Our aim was to assess the incidence of long term restenosis after CAS and to identify some predictors of restenosis. Methods. We retrospectively selected 189 treated patients and we obtained the survival Kaplan-Meier curves for overall survival, for freedom from stroke or death and from restenosis. To correlate clinical, radiological, and procedural variables to stent restenosis, an univariate analysis was performed while to determine independent predictors of restenosis, a multivariate analysis was applied. Results. At 1, 3, and 5 years, the cumulative overall survival rate was 98%, 94%, and 92% with a cumulative primary patency rate of 87%, 82.5%, and 82.5%. The percentage residual stenosis after CAS and multiple stents deployment were independent predictors of restenosis, while diabetes and tumors are suggestive but not significant predictors of restenosis. Conclusions. In our CAS experience, encouraging long-term results seem to derive from both neurological event free rate and restenosis incidence. Adequate recanalization of the treated vessel is important to limit the development of stent restenosis. Multiple stents deployment, and with less evidence, diabetes, or neoplasms has to be considered to facilitate restenosis
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
ANEURYSM OF THE VERTEBRAL ARTERY PICA JUNCTION ASSOCIATED WITH POSTERIOR FOSSA ARTERIOVENOUS MALFORMATION. ONE CASE REPORT AND REVIEW OF THE LITERATURE
Niels Stensen (1638-1686): scientist, neuroanatomist, and saint
Niels Stensen (1638-1686) was a prominent Danish scientist who laid the foundations of paleontology, geology, and crystallography. He undertook a personal search for the truth, rejecting many assumptions of his time, and he struggled to acquire a firm foundation of knowledge based on close observation and rigorous experimentation. Niels Stensen is known eponymously for the discovery of the duct of the parotid gland (ductus stenonianus) but most clinicians are not familiar with his contributions to anatomy beyond his studies on the glands. In 1665, he delivered a lecture in Paris on the anatomy of the brain, the Discours sur l'anatomie du cerveau ("A Dissertation on the Anatomy of the Brain"), which is a seminal investigation on methods in neuroscience. His scientific letter on a hydrocephalic calf represents an early pathophysiological investigation on hydrocephalus. In 1667 Stensen converted to Catholicism and in 1677 he was consecrated titular bishop of Titiopolis. He spent the last years of his life in poverty and traveled continuously trying to bring back northern Europe to Catholicism. This essay highlights the life and the scientific contributions of Niels Stensen, with emphasis on his contributions to neuroscience
Silent Cerebral Microembolism in Asymptomatic and Symptomatic Carotid Artery Stenoses of Low and High Degree
MALIGNANT TRANFFORMATION OF INTRAMEDULLARY MELANOCYTOMA
OBJECTIVE:
Meningeal melanocytomas are low-grade primary melanocytic tumors with benign histological features and a favorable clinical prognosis. Transition from meningeal melanocytoma to primary melanoma of the central nervous system is exceptionally rare, with only 5 cases having been previously reported. Here, we discuss a case of malignant transformation of an intramedullary melanocytoma to primary melanoma and review the pertinent literature.
CLINICAL PRESENTATION:
A 79-year-old woman presented with progressive paresis in the lower limbs followed by sphincter dysfunction. Magnetic resonance imaging scans disclosed an intramedullary lesion located at the T10-T11 level.
INTERVENTION:
The patient underwent subtotal resection of an intermediate-grade melanocytoma. Two years later, the tumor recurred locally, and the patient underwent additional surgery to remove the intramedullary mass. The histological findings of the tumor were consistent with an intramedullary malignant melanoma.
CONCLUSION:
The malignant transformation of melanocytic tumors of the central nervous system may occur years after surgical treatment, and its incidence remains unknown. Emphasis should be placed on the importance of careful and continued follow-up monitoring of the tumor
Unusual exophytic subependymoma in the bulbo-cerebellar angle. Case report
Subependymoma was first described by Scheinker in 1945; it frequently occurs in the ventricles and rarely in the spinal canal representing 0.7% of all central nervous system tumours. Most of these intraventricular tumours are subclinical entities, remaining of small size and discovered at autopsy with 0.4%incidence. We report a case of subependymoma with a completely exophytic growth from the foramen of Luscka: only a similar one has been described in the literature but with a lesser cysternal involvement. Neuroradiological and anatomopathological features of subependymoma are discussed
Delayed otogenic pneumocephalus complicating ventriculoperitoneal shunt
Tension pneumocephalus complicating ventriculoperitoneal shunt is
extremely rare. We report an elderly male who developed delayed tension
pneumocephalus 12 months after ventriculoperitoneal shunt for
hydrocephalus complicating aneurysmal subarachnoid hemorrhage. Fine-cut
reformatted computer tomography scan revealed a large pneumatocele on
the petrous apex associated with tegmen tympani defect. The shunt valve
pressure was temporarily raised from 120 mm H 2 O to 200 mm H 2 O, and
the patient underwent successful subtemporal extradural repair of the
bony defect in the temporal bone. Although extremely rare, otogenic
tension pneumocephalus is a potentially life-threatening condition, and
urgent surgical repair of the bony defect in the temporal bone reduces
the risk of both the morbidity and mortality
Soluble and cell bound gamma-glutamyltransferase activity – factors in LDL peroxidation, atherogenesis and cardiovascular disease
Soluble and cell bound gamma-glutamyltransferase activity – factors in LDL peroxidation, atherogenesis and cardiovascular diseas