33 research outputs found

    Mimicking the Neurotrophic Factor Profile of Embryonic Spinal Cord Controls the Differentiation Potential of Spinal Progenitors into Neuronal Cells

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    Recent studies have indicated that the choice of lineage of neural progenitor cells is determined, at least in part, by environmental factors, such as neurotrophic factors. Despite extensive studies using exogenous neurotrophic factors, the effect of endogenous neurotrophic factors on the differentiation of progenitor cells remains obscure. Here we show that embryonic spinal cord derived-progenitor cells express both ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF) mRNA before differentiation. BDNF gene expression significantly decreases with their differentiation into the specific lineage, whereas CNTF gene expression significantly increases. The temporal pattern of neurotrophic factor gene expression in progenitor cells is similar to that of the spinal cord during postnatal development. Approximately 50% of spinal progenitor cells differentiated into astrocytes. To determine the effect of endogenous CNTF on their differentiation, we neutralized endogenous CNTF by administration of its polyclonal antibody. Neutralization of endogenous CNTF inhibited the differentiation of progenitor cells into astrocytes, but did not affect the numbers of neurons or oligodendrocytes. Furthermore, to mimic the profile of neurotrophic factors in the spinal cord during embryonic development, we applied BDNF or neurotrophin (NT)-3 exogenously in combination with the anti-CNTF antibody. The exogenous application of BDNF or NT-3 promoted the differentiation of these cells into neurons or oligodendrocytes, respectively. These findings suggest that endogenous CNTF and exogenous BDNF and NT-3 play roles in the differentiation of embryonic spinal cord derived progenitor cells into astrocytes, neurons and oligodendrocytes, respectively

    Pituitary society expert Delphi consensus: operative workflow in endoscopic transsphenoidal pituitary adenoma resection

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    Abstract: Purpose: Surgical workflow analysis seeks to systematically break down operations into hierarchal components. It facilitates education, training, and understanding of surgical variations. There are known educational demands and variations in surgical practice in endoscopic transsphenoidal approaches to pituitary adenomas. Through an iterative consensus process, we generated a surgical workflow reflective of contemporary surgical practice. Methods: A mixed-methods consensus process composed of a literature review and iterative Delphi surveys was carried out within the Pituitary Society. Each round of the survey was repeated until data saturation and > 90% consensus was reached. Results: There was a 100% response rate and no attrition across both Delphi rounds. Eighteen international expert panel members participated. An extensive workflow of 4 phases (nasal, sphenoid, sellar and closure) and 40 steps, with associated technical errors and adverse events, were agreed upon by 100% of panel members across rounds. Both core and case-specific or surgeon-specific variations in operative steps were captured. Conclusions: Through an international expert panel consensus, a workflow for the performance of endoscopic transsphenoidal pituitary adenoma resection has been generated. This workflow captures a wide range of contemporary operative practice. The agreed “core” steps will serve as a foundation for education, training, assessment and technological development (e.g. models and simulators). The “optional” steps highlight areas of heterogeneity of practice that will benefit from further research (e.g. methods of skull base repair). Further adjustments could be made to increase applicability around the world

    Prolactinomas, Cushing's disease and acromegaly: debating the role of medical therapy for secretory pituitary adenomas

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    Pituitary adenomas are associated with a variety of clinical manifestations resulting from excessive hormone secretion and tumor mass effects, and require a multidisciplinary management approach. This article discusses the treatment modalities for the management of patients with a prolactinoma, Cushing's disease and acromegaly, and summarizes the options for medical therapy in these patients

    Outcomes after repeat transsphenoidal surgery for recurrent Cushing's disease

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    OBJECTIVE: To systematically analyze patient outcomes after repeat transsphenoidal (TS) surgery for recurrent Cushing's disease. METHODS: We retrospectively reviewed records of all patients with recurrent Cushing's disease who underwent repeat TS surgery for resection of a pituitary corticotroph adenoma at the University of Virginia Medical Center from 1992 to 2006. Remission at follow-up was defined as a normal postoperative 24-hour urine free cortisol, or continued need for glucocorticoid replacement after repeat TS surgery. Recurrence of the disease was defined as an elevated 24-hour urine free cortisol with clinical symptoms consistent with Cushing's disease while not receiving glucocorticoid replacement. Multivariate logistic regression was performed to evaluate the effect of potential predictors on remission. Recurrence rates, subsequent treatments, and the final endocrine status of the patients are presented. RESULTS: We identified 36 patients who underwent repeat TS surgery for recurrent Cushing's disease. The mean age of the patients was 40.3 years (range, 17.1-63.0 yr), and 26 were women. The median time to recurrence after initial successful TS surgery was 36 months (range, 4 mo-16 yr). Remission after repeat TS surgery was observed in 22 (61%) of the 3 6 patients. During the same time period, of the 338 patients who underwent first-time TS surgery for Cushing's disease, remission was achieved in 289 (85.5%). The odds of failure (to achieve remission) for patients with repeat TS surgery for recurrent Cushing's disease were 3.7 times that of patients undergoing first-time TS surgery (odds ratio, 3.7; 95% confidence interval, 1.8-7.8). Two of the 22 patients with successful repeat TS surgery had a second recurrence at 6 and 11 months, respectively. Complete biochemical and clinical remission after stereotactic radiosurgery, adrenalectomy, and ongoing ketoconazole therapy was achieved in 30 (83.3%) of the 36 patients, and active disease continued in 6 patients (16.7%). CONCLUSION: Although the success of repeat TS surgery for recurrence of Cushing's disease is less than that of initial surgery, a second procedure offers a reasonable possibility of immediate remission, if the operation is not successful, other treatments, including pituitary radiation, medical therapy, and even bilateral adrenalectomy, are required
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