Pituitary stem cells: candidates and implications.

The pituitary is the master endocrine gland of the body. It undergoes many changes after birth, and these changes may be mediated by the differentiation of pituitary stem cells. Stem cells in any tissue source must display (1) pluripotent capacity, (2) capacity for indefinite self-renewal, and (3) a lack of specialization. Unlike neural stem cells identified in the hippocampus and subventricular zone, pituitary stem cells are not associated with one specific cell type. There are many major candidates that are thought to be potential pituitary stem cell sources. This article reviews the evidence for each of the major cell types and discuss the implications of identifying a definitive pituitary stem cell type.

Comparing the Effects of Early Versus Late Exercise Intervention on Pain and Neurodynamic Mobility Following Unilateral Lumbar Microdiscectomy: A Pilot Study.

STUDY DESIGN: A pilot, two-group pretest-posttest randomized controlled, single blinded study. OBJECTIVE: Our study aim was to compare the changes in low back pain level, fear avoidance, neurodynamic mobility, and function after early versus later exercise intervention following a unilateral lumbar microdiscectomy. SUMMARY OF BACKGROUND DATA: Exercise is commonly recommended to patients following a lumbar microdiscectomy although controversy remains as to the timing and protocols for exercise intervention. METHODS: Forty patients were randomly allocated to early (Group 1) or later (Group 2) exercise intervention group. The low back pain and fear avoidance were evaluated using Oswestry Low Back Pain Disability Questionnaire, Numeric Pain Rating Scale, and Fear-Avoidance Beliefs Questionnaire. The neurodynamic mobility and function were recorded with Dualer Pro IQ Inclinometer, 50-foot walk test, and Patient-Specific Functional Scale. Two-sided t test for continuous variables and chi-square or Fisher exact test for categorical variables were used to compare the two groups' demographic data. The Wilcoxon signed-rank and rank-sum tests were used to compare the changes and the differences, respectively, in low back pain, fear avoidance, neurodynamic mobility, and function between baseline (before surgery) and postoperative repeated measurements (at 1-2, 4-6, and 8-10 wks after surgery) within each study group, after exercise intervention. RESULTS: Both groups showed a significant decrease in low back pain levels and fear avoidance as well as a significant improvement in neurodynamic mobility and function at 4 and 8 weeks after surgery. However, no significant difference was reported between the two groups. CONCLUSION: Our study results showed that early exercise intervention after lumbar microdiscectomy is safe and may reduce the low back pain, decrease fear avoidance, and improve neurodynamic mobility and function. A randomized controlled trial is needed to evaluate the early exercise intervention's effectiveness after lumbar microdiscectomy, and thus validate our findings.Level of Evidence: 4.

A short illustrated review of sellar region schwannomas.

INTRODUCTION: In this short illustrated review, we present the case of a frontal lobe schwannoma without cranial nerve or sellar attachment and a sellar schwannoma which mimicked a pituitary adenoma. LITERATURE REVIEW: We review the rare occurrence of sellar region schwannomas, their clinical presentation, operative management, outcomes, and the possible pathogenesis. ANALYSIS: The absence of Schwann cells in the central nervous system and the absence of neighboring cranial nerves in these two cases raise issues of the pathogenesis of these rare but curious lesions.

Pituitary adenoma with peliosis: a report of two cases.

Peliosis is characterised by multiple blood-filled lakes or cavities within parenchymatous organs. Typically found in the liver, spleen, bone marrow and lymph nodes, it has also been described in other organs such as lungs, kidneys, parathyroids and pancreas. The mechanism responsible for the development of peliosis remains unknown. (1) A 69 year-old man with a 6-year history of acromegaly underwent transsphenoidal surgery for pituitary adenoma. Morphologic findings demonstrated a plurimorphous plurihormonal pituitary adenoma consisting of somatotrophs, lactotrophs and mammosomatotrophs. The tumor contained several blood-filled cavities characteristic of peliosis. (2) A 61-year-old man with a prolactin-producing pituitary adenoma who underwent transsphenoidal surgery. In the tumor, peliosis was noted. Peliosis in a pituitary adenoma is an intriguing finding. The question arises whether it represents vasculogenic mimicry.

Clinical equipoise in idiopathic normal pressure hydrocephalus: a survey of physicians on the need for randomized controlled trials assessing the efficacy of cerebrospinal fluid diversion.

BACKGROUND: Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome that may be reversible by diversion of cerebrospinal fluid (CSF). It is increasingly recognized, and accordingly rates of CSF diversion are increasing despite the absence of level I evidence of efficacy, non-neglible rate of complications and an unclear natural history. METHODS: A total of 349 neurosurgeons, neurologists, geriatricians and neuropsychiatrists rated the perceived efficacy of CSF diversion, the duration of effect of CSF diversion, and the risk-benefit ratio of CSF diversion in iNPH. These physicians then rated the need for a randomized controlled trial (RCT) of CSF diversion in iNPH. Participants detailed their desired selection criteria and supportive testing for a RCT, and their preferred control group. RESULTS: Physicians believe that there is uncertain efficacy of CSF diversion in iNPH, as well as the expected duration of this benefit and the risk-benefit ratio for patients. The greatest degree of uncertainty related to the long-term benefit of surgery. Accordingly, over 75% desire a RCT to determine the efficacy of CSF diversion in iNPH. Only 2.7% of participants believe a RCT of CSF diversion in iNPH is unethical. Patients without a shunt and a programmable valve in the 'off' setting were the preferred control groups. CONCLUSION: A RCT of CSF diversion in iNPH is absent from the literature. The majority (>75%) of physicians involved in the diagnosis and treatment of iNPH believe a RCT is required to determine the efficacy, duration of efficacy and risk-benefit ratio of CSF diversion in iNPH.

Telemedicine as a potential medium for teaching the advanced trauma life support (ATLS) course.

OBJECTIVES: The advanced trauma life support (ATLS) course has become the international standard for teaching trauma resuscitation skills. The 2 to 2.5 days course is usually offered as an on-site teaching experience. The present project assesses the potential for applying telemedicine technology to teaching ATLS by distance learning. DESIGN: Two groups of equally trained first-year family practice residents were randomly assigned to a standard on-site ATLS course or one delivered by telemedicine. The 2 courses were compared by evaluating post-ATLS multiple-choice question test performance, instructor evaluation of student skill station performance, overall pass rate, participant rating of each component of the course, and overall feedback on the educational quality of the course (rating scale 1-4). RESULTS: The mean scores for the 2 groups (with the standard ATLS and with the telemedicine, respectively) were not statistically significantly different: post-ATLS multiple-choice question-89.69% vs 85.89%; pass rate for the course was the same for both models; instructor overall evaluation of student skill station performance-3.12 vs 3.00; and participant overall feedback on all components of the course-3.67 vs 3.91. CONCLUSIONS: Our results suggest that telemedicine technology could be successfully applied to teaching ATLS courses.

O-methylguanine-DNA methyltransferase immunoexpression in a double pituitary adenoma: case report.

OBJECTIVE: Double pituitary adenomas in surgical cases are rarely reported. The incidence in published surgical specimens ranges from 0.4% to 1.3%. We present a treatment dilemma of a double adenoma that had differential O-methylguanine-DNA methyltransferase (MGMT) reactivity. CLINICAL PRESENTATION: A 48-year-old man presented with acromegaly and a recurrent pituitary adenoma. He had elevated growth hormone (GH) and elevated insulin-like growth factor blood levels and hyperprolactinemia. INTERVENTION: Subtotal transsphenoidal resection was performed. Morphologic examination disclosed 2 histologically distinct tumors, including a GH adenoma and a prolactin adenoma. Immunohistochemistry revealed Ki-67 labeling indices of 1% and 2%, respectively. Of significant note was MGMT immunopositivity in the GH adenoma and lack of staining in the prolactin adenoma. CONCLUSION: This is the first clinical instance in which MGMT was assessed in double adenomas of the pituitary. The 2 tumors showed significant differences in reactivity that could impact chemotherapeutic management. The adenomas underwent recurrence, a feature that reflects their invasive nature and the possibility that chemotherapeutic intervention may be required in the future. Response to temozolomide use is anticipated with respect to the prolactin adenoma but would likely not benefit the GH cell adenoma of our patient.

Use of temozolomide in aggressive pituitary tumors: case report.

OBJECTIVE: The management of aggressive pituitary macroadenomas represents a challenge to neurosurgeons. These tumors are very difficult to treat, owing mainly to their invasive nature, thus resulting in incomplete resections and propensity for recurrence. Multiple surgical procedures (transsphenoidal, transcranial, or a combination of both) are the first line management, followed by radiotherapy and chemotherapy. CLINICAL PRESENTATION: Three cases of patients with pituitary adenomas who underwent temozolomide treatment are presented. The first 2 patients had corticotroph macroadenoma of the Crooke's cell variant. Deterioration occurred in both cases despite multiple surgeries and adjuvant therapy. The third patient had a glioblastoma multiforme with an incidental pituitary tumor. INTERVENTION: All 3 patients had temozolomide administered orally on the first 5 days of a 28-day cycle for 12 cycles. Magnetic resonance imaging, endocrinological, and clinical follow-up were performed at monthly intervals. CONCLUSION: The marked improvement in clinical state of the first 2 patients accompanied by radiological evidence of tumor shrinkage in all patients demonstrates the potential use of temozolomide in treating aggressive pituitary macroadenomas. The usefulness of temozolomide in aggressive pituitary adenomas should be studied in larger trials.