Edward H. Oldfield

Safety and feasibility of long-term intravenous sodium nitrite infusion in healthy volunteers

Background Infusion of sodium nitrite could provide sustained therapeutic concentrations of nitric oxide (NO) for the treatment of a variety of vascular disorders. The study was developed to determine the safety and feasibility of prolonged sodium nitrite infusion. Methodology Healthy volunteers, aged 21 to 60 years old, were candidates for the study performed at the National Institutes of Health (NIH; protocol 05-N-0075) between July 2007 and August 2008. All subjects provided written consent to participate. Twelve subjects (5 males, 7 females; mean age, 38.8±9.2 years (range, 21–56 years)) were intravenously infused with increasing doses of sodium nitrite for 48 hours (starting dose at 4.2 µg/kg/hr; maximal dose of 533.8 µg/kg/hr). Clinical, physiologic and laboratory data before, during and after infusion were analyzed. Findings The maximal tolerated dose for intravenous infusion of sodium nitrite was 267 µg/kg/hr. Dose limiting toxicity occurred at 446 µg/kg/hr. Toxicity included a transient asymptomatic decrease of mean arterial blood pressure (more than 15 mmHg) and/or an asymptomatic increase of methemoglobin level above 5%. Nitrite, nitrate, S-nitrosothiols concentrations in plasma and whole blood increased in all subjects and returned to preinfusion baseline values within 12 hours after cessation of the infusion. The mean half-life of nitrite estimated at maximal tolerated dose was 45.3 minutes for plasma and 51.4 minutes for whole blood. Conclusion Sodium nitrite can be safely infused intravenously at defined concentrations for prolonged intervals. These results should be valuable for developing studies to investigate new NO treatment paradigms for a variety of clinical disorders, including cerebral vasospasm after subarachnoid hemorrhage, and ischemia of the heart, liver, kidney and brain, as well as organ transplants, blood-brain barrier modulation and pulmonary hypertension. Clinical Trial Registration Information http://www.clinicaltrials.gov; NCT00103025

Outcome of Surgical Treatment of 200 Children With Cushing's Disease

CONTEXTnFactors influencing the outcome of surgical treatment of pediatric Cushings disease (CD) have not been fully established.nnnOBJECTIVEnThe aim of this study was to examine features influencing the outcome of surgery for pediatric CD.nnnDESIGNnIn this prospective observational study, the clinical, imaging, endocrinological, and operative outcomes were analyzed in consecutive patients treated at the National Institutes of Health (NIH) from 1982 through 2010.nnnSETTINGnThe study was conducted in a tertiary referral center.nnnRESULTSnTwo hundred CD patients (106 females, 94 males) were included. Mean age at symptom development was 10.6 ± 3.6 years (range, 4.0 to 19.0 y). Mean age at NIH operation was 13.7 ± 3.7 years. Twenty-seven patients (13%) had prior surgery at another institution. Magnetic resonance imaging identified adenomas in 97 patients (50%). When positive, magnetic resonance imaging accurately defined a discrete adenoma in 96 of the 97 patients (99%), which was more accurate than the use of ACTH ratios during inferior petrosal sinus sampling to determine adenoma lateralization (accurate in 72% of patients without prior surgery). A total of 195 of the 200 patients (98%) achieved remission after surgery (189 [97%] were hypocortisolemic; 6 [3%] were eucortisolemic postoperatively). Factors associated with initial remission (P < .05) included identification of an adenoma at surgery, immunohistochemical ACTH-producing adenoma, and noninvasive ACTH adenoma. Younger age, smaller adenoma, and absence of cavernous sinus wall or other dural invasion were associated with long-term remission (P < .05). A minimum morning serum cortisol of less than 1 μg/dl after surgery had a positive predictive value for lasting remission of 96%.nnnCONCLUSIONSnWith rare disorders, such as pediatric CD, enhanced outcomes are obtained by evaluation and treatment at centers with substantial experience. Resection of pituitary adenomas in pediatric CD in that setting can be safe, effective, and durable. Early postoperative endocrine testing predicts lasting remission. Because lasting remission is associated with younger age at surgery, smaller adenomas, and lack of dural invasion, early diagnosis should improve surgical outcome.

X-linked acrogigantism syndrome: clinical profile and therapeutic responses.

X-linked acrogigantism (X-LAG) is a new syndrome of pituitary gigantism, caused by microduplications on chromosome Xq26.3, encompassing the gene GPR101, which is highly upregulated in pituitary tumors. We conducted this study to explore the clinical, radiological, and hormonal phenotype and responses to therapy in patients with X-LAG syndrome. The study included 18 patients (13 sporadic) with X-LAG and microduplication of chromosome Xq26.3. All sporadic cases had unique duplications and the inheritance pattern in two families was dominant, with all Xq26.3 duplication carriers being affected. Patients began to grow rapidly as early as 2-3 months of age (median 12 months). At diagnosis (median delay 27 months), patients had a median height and weight standard deviation scores (SDS) of >+3.9 SDS. Apart from the increased overall body size, the children had acromegalic symptoms including acral enlargement and facial coarsening. More than a third of cases had increased appetite. Patients had marked hypersecretion of GH/IGF1 and usually prolactin, due to a pituitary macroadenoma or hyperplasia. Primary neurosurgical control was achieved with extensive anterior pituitary resection, but postoperative hypopituitarism was frequent. Control with somatostatin analogs was not readily achieved despite moderate to high levels of expression of somatostatin receptor subtype-2 in tumor tissue. Postoperative use of adjuvant pegvisomant resulted in control of IGF1 in all five cases where it was employed. X-LAG is a new infant-onset gigantism syndrome that has a severe clinical phenotype leading to challenging disease management.

The Lateralization Accuracy of Inferior Petrosal Sinus Sampling in 501 Patients With Cushing's Disease

CONTEXTnIt is often difficult to find an adenoma in patients with Cushings disease (CD) whose preoperative magnetic resonance imaging (MRI) is normal. Better localizing modalities are needed.nnnOBJECTIVEnThe aim of this study was to determine the accuracy of inferior petrosal sinus sampling (IPSS) in predicting adenoma lateralization.nnnDESIGN AND SETTINGnWe conducted a prospective observational study at a tertiary care clinical research center.nnnPATIENTSnA total of 501 consecutive patients (363 female) with confirmed ACTH adenomas and IPSS were included.nnnMAIN OUTCOME MEASUREnWe measured the accuracy of IPSS to predict the intrasellar location of an adenoma.nnnRESULTSnIPSS confirmed a pituitary source of ACTH secretion in 491 patients (98%). All 10 patients with false-negative results had peak IPSS ACTH concentrations (before or after CRH) of < 400 pg/ml. Interpetrosal (side-to-side) ratios were ≥ 1.4 in 491 patients (98%). This ratio correctly predicted lateralization in 273 of 396 patients (positive predictive value = 69%) with a lateral adenoma. Left-sided IPSS lateralization (P = .008) and consistent lateralization before and after CRH administration (P = .02) were associated with enhanced accuracy. When positive, preoperative MRI correlated with adenoma location in 171 of 201 patients (positive predictive value = 86%).nnnCONCLUSIONSnPotential false-negative results, the most common type of diagnostic error with IPSS for the differential diagnosis of CS, can be identified by peak IPSS ACTH values < 400 pg/ml. When MRI is normal, IPSS can be used to guide surgical exploration in patients with negative preoperative imaging. However, because of the limited accuracy of lateralization, thorough exploration of the pituitary gland is required when an adenoma is not readily discovered based on predicted location.

Long-term outcome after resection of brainstem hemangioblastomas in von Hippel-Lindau disease

OBJECTnBrainstem hemangioblastomas are frequently encountered in patients with von Hippel-Lindau (VHL) disease. These tumors can cause significant morbidity, and their optimal management has not been defined. To better define the outcome and management of these tumors, the authors analyzed the long-term results in patients who underwent resection of brainstem hemangioblastomas.nnnMETHODSnConsecutive patients with VHL disease who underwent resection of brainstem hemangioblastomas with a follow-up of 12 months or more were included in this study. Serial functional assessments, radiographic examinations, and operative records were analyzed.nnnRESULTSnForty-four patients (17 male and 27 female) underwent 51 operations for resection of 71 brainstem hemangioblastomas. The most common presenting symptoms were headache, swallowing difficulties, singultus, gait difficulties, and sensory abnormalities. The mean follow-up was 5.9 ± 5.0 years (range 1.0-20.8 years). Immediately after 34 operations (66.7%), the patients remained at their preoperative functional status; they improved after 8 operations (15.7%) and worsened after 9 operations (17.6%) as measured by the McCormick scale. Eight (88.9%) of the 9 patients who were worse immediately after resection returned to their preoperative status within 6 months. Two patients experienced functional decline during long-term follow-up (beginning at 2.5 and 5 years postoperatively) caused by extensive VHL disease-associated CNS disease.nnnCONCLUSIONSnGenerally, resection of symptomatic brainstem hemangioblastomas is a safe and effective management strategy in patients with VHL disease. Most patients maintain their preoperative functional status, although long-term decline in functional status may occur due to VHL disease-associated progression.

Pseudotumor Cerebri after Surgical Remission of Cushing’s Disease

CONTEXTnPseudotumor cerebri has only been described after successful surgery for Cushings disease (CD) in case reports. We sought to establish the incidence and timing of its occurrence, identify predisposing factors, characterize the clinical presentations and their severity, and examine the effects of treatment in patients who underwent surgery for CD.nnnSETTINGnThis study was conducted at two tertiary care centers: The University of Virginia and the National Institutes of Health.nnnPATIENTSnWe conducted a retrospective review of 941 surgeries for CD (723 adults, 218 children) to identify patients who developed pseudotumor cerebri after surgery for CD and examine the associated clinical features.nnnRESULTSnSeven children (four males, three females; 3%), but no adults, developed pseudotumor cerebri postoperatively. All underwent resection of an ACTH-secreting adenoma, and postoperative serum cortisol reached a nadir of less than 2 microg/dl. After surgery, all were placed on tapering hydrocortisone replacement therapy. Within 3-52 wk, all seven patients experienced symptoms of pseudotumor cerebri and had ophthalmological examination demonstrating papilledema. One patient had diplopia from a unilateral VIth nerve palsy. Six patients were still on steroid replacement at onset of symptoms. In three patients, a lumbar puncture demonstrated elevated opening pressure. Four patients were treated successfully with a lumbar puncture, steroids, and/or Diamox. Three patients did not receive treatment, and their symptoms resolved over several months. There was no correlation between the degree of hypercortisolism (24-h urinary free cortisol) before surgery and the likelihood of developing pseudotumor cerebri after surgery (P < 0.23).nnnCONCLUSIONSnThis series demonstrates a 3% occurrence of pseudotumor cerebri in children after successful surgery for CD, but the absence of the syndrome in adults. Pseudotumor cerebri manifests itself within 1 yr of surgery, often while patients are still undergoing replacement steroid therapy. A patient exhibiting signs of intracranial hypertension after surgery for CD should undergo an evaluation for pseudotumor cerebri. Recognition of the symptoms and treatment should correct and/or prevent ophthalmological sequelae.

Nervous system involvement in von Hippel-Lindau disease: pathology and mechanisms

Patients with von Hippel–Lindau disease carry a germline mutation of the Von Hippel–Lindau (VHL) tumor-suppressor gene. We discuss the molecular consequences of loss of VHL gene function and their impact on the nervous system. Dysfunction of the VHL protein causes accumulation and activation of hypoxia inducible factor (HIF) which can be demonstrated in earliest stages of tumorigenesis and is followed by expression of VEGF, erythropoietin, nitric oxide synthase and glucose transporter 1 in VHL-deficient tumor cells. HIF-independent functions of VHL, epigenetic inactivation of VHL, pVHL proteostasis, and links between loss of VHL function and developmental arrest are also described. A most intriguing feature in VHL disease is the occurrence of primary hemangioblastic tumors in the nervous system, the origin of which has not yet been entirely clarified, and current hypotheses are discussed. Endolymphatic sac tumors may extend into the brain, but originally arise from proliferation of endolymphatic duct/sac epithelium; the exact nature of the proliferating epithelial cell, however, also has remained unclear, as well as the question why tumors almost consistently develop in the intraosseous portion of the endolymphatic sac/duct only. The epitheloid clear cell morphology of both advanced hemangioblastoma and renal clear cell carcinoma can make the differential diagnosis challenging, recent developments in immunohistochemical differentiation are discussed. Finally, metastasis to brain may not only be caused by renal carcinoma, but may derive from VHL disease-associated pheochromocytoma/paraganglioma, or pancreatic neuroendocrine tumor.

Surgical management of Cushing’s disease

BackgroundTranssphenoidal selective adenomectomy is the first-line treatment for Cushing’s disease. At experienced centers, early remission rates after transsphenoidal surgery range from 65 to 98xa0%, however disease relapse frequently occurs with rates ranging from 2 to 35xa0% at long-term follow up.MethodsThis article discusses recently reported studies on the surgical outcomes from transsphenoidal surgery for Cushings disease.ConclusionsOne of the keys to a successful long-term surgical outcome is meticulous dissection using the adenoma’s pseudocapsule as a surgical plane for complete resection. MRI-negative and invasive ACTH-secreting adenomas pose particular challenges for pituitary surgeons.

Report of selective cortical infarcts in the primate clot model of vasospasm after subarachnoid hemorrhage.

BACKGROUNDIn human autopsy studies, 70% to 80% of patients with aneurysmal subarachnoid hemorrhage (SAH) showed infarcts in cerebral cortex covered by subarachnoid blood. Thus far, no animal model of SAH is known to produce this peculiar infarct pattern, and its pathogenesis remains enigmatic. OBJECTIVETo investigate whether such infarcts occur in the clot model of SAH in primates. METHODSWe performed a retrospective pathological review of 16 primate brains. In 13 cynomolgus monkeys, a blood clot was placed around the middle cerebral artery after additional removal of the arachnoid membrane from the basal surface of the frontal and temporal cortexes. Three animals underwent sham surgery without placement of a blood clot (controls). The brains were harvested between days 1 and 28 after SAH and examined by a neuropathologist blinded to study group. RESULTSWe identified 2 types of cortical infarcts. A band of selective cortical laminar necrosis parallel to the cortical surface (“horizontal”) was found in 5 animals. The second category of cortical lesions had a “vertical” extension. It included wedge-shaped (n = 2) or pillarlike (n = 2) necrosis. Both horizontal and vertical infarcts were located exclusively in areas adjacent to subarachnoid blood. The presence of a cortical infarct did not correlate with the degree of middle cerebral artery vasospasm (r2 = .24, P = .13). CONCLUSIONThe presence of cortical infarcts suggests that a modified nonhuman primate model of SAH is suitable to examine the pathogenesis of proximal vasospasm and permits investigation of cortical lesions similar to those reported in patients after SAH. Furthermore, it indicates that direct effects of the blood clot on the brain and microcirculation contribute to the development of cortical infarcts after SAH.

Normalized Early Postoperative Cortisol and ACTH Values Predict Nonremission After Surgery for Cushing Disease

ContextnPerioperative increases in adrenocorticotropic hormone (ACTH) and cortisol mimic results of corticotropin-releasing hormone (CRH) stimulation testing. This phenomenon may help identify patients with residual adenoma after transsphenoidal surgery (TSS) for Cushing disease (CD).nnnObjectivenTo predict nonremission after TSS for CD.nnnDesignnRetrospective case-control study of patients treated at a single center from December 2003 until July 2016. Early and medium-term remission were assessed at 10 days and 11 months.nnnPatients and SettingnTwo hundred and ninety-one consecutive TSS cases from 257 patients with biochemical evidence of CD seen at a clinical center.nnnInterventionsnNormalized early postoperative values (NEPVs) for cortisol and ACTH were calculated as immediate postoperative cortisol or ACTH levels minus preoperative post-CRH-stimulation test levels.nnnMain Outcome MeasuresnPrediction of early nonremission was evaluated using logistic regression. Prediction of medium-term remission was assessed using Cox regression. Predictive ability was quantified by area under the receiver operating characteristic curve (AUROC).nnnResultsnNEPVs for cortisol and ACTH predicted early nonremission [adjusted odds ratio (OR): 1.1; 95% confidence interval (CI): 1.0, 1.1; P = 0.016 and adjusted OR: 1.0; 95% CI: 1.0, 1.0; P = 0.048, respectively]. AUROC for NEPV of cortisol was 0.78 (95% CI: 0.61, 0.95); for NEPV of ACTH, it was 0.80 (95% CI: 0.61, 0.98). NEPVs for cortisol and ACTH predicted medium-term nonremission [hazard ratio (HR): 1.1; 95% CI: 1.0, 1.1; P = 0.023 and HR: 1.0; 95% CI: 1.0, 1.0; P = 0.025, respectively].nnnConclusionsnNEPVs for cortisol and ACTH predicted nonremission after TSS for CD.