Measurement Of Catecholamines Research Articles

Autonomic nervous system responses to hypo- and hyperglycemia in type 2 diabetes and prediabetes.

Previous research points to a role of the brain in the regulation of glucose and pathogenesis of type 2 diabetes (T2D) via modulation of counter-regulatory hormone secretion and activity in the autonomic nervous system (ANS). The aim of this study was to investigate glucose-dependent responses of catecholamines and ANS activity in individuals with T2D, prediabetes (PD), and normoglycemia (NG). Cross-sectional. Individuals with T2D (n = 19, 7 men, HbA1c 49 mmol/mol), PD (n = 18, 8 men), and NG (n = 17, 3 men) underwent 1 stepwise hyperinsulinemic-euglycemic-hypoglycemic and 1 hyperglycemic clamp with repeated measurements of catecholamines, symptoms, heart rate variability (HRV), and hemodynamics. The hypoglycemic response of adrenaline was augmented in T2D and PD vs NG (both P < .05), and there was a strong association with insulin resistance (P < .05 for M-value). In relation to achieved glucose levels in both clamps, noradrenaline exhibited a steeper rise during hypoglycemia in T2D vs NG and PD (both P < .05). There were trends toward more marked autonomic hypoglycemic symptoms in T2D vs PD and NG. By contrast, insulin resistance was associated with attenuated responses of heart rate and HRV indices PLF and PHF at the target glucose plateau of 2.7 mmol/L (P < .05), independent of BMI and HbA1c. Alterations in glucose-dependent responses of counter-regulatory hormones and the ANS appear before, and probably contribute to, the onset of T2D. Together with other reported alterations in neuroendocrine pathways, the findings suggest that a maladaptation of the brain's responses to glucose fluctuations is important in T2D progression.

Energy Expenditure in Critically Ill Patients with Aneurysmal Subarachnoid Hemorrhage, Intracerebral Hemorrhage, and Traumatic Brain Injury-A Prospective Observational Study.

Energy expenditure (EE) in patients with aneurysmal subarachnoid hemorrhage (SAH) may differ from other intracranial pathologies, such as intracerebral hemorrhage (ICH) or traumatic brain injury (TBI), due to an activation of the sympathetic nervous system. Indirect calorimetry (IC) is recommended, but is not always available. We study EE, catabolism, and metabolic stress in patients with SAH, TBI, ICH, and sepsis as controls. A prospective observational study was conducted in the intensive care units of the University Medical Center Hamburg-Eppendorf, Germany. IC was used to measure EE on days 2-3, 5-7, and 10-15 post-admission. Urinary catecholamines, metabolites, and urine urea were also measured. Statistical analysis included t-tests, Chi-square tests, and generalized mixed models. We included 110 patients-43 SAH patients (13 with the surgical securing of the aneurysm and 30 with coil embolization of the aneurysm), 22 TBI patients, 23 ICH patients, and 22 controls. The generalized linear mixed model analysis for groups and timepoints including age, height, and weight as covariates revealed a significantly lower EE at timepoint 1 for ICH versus SAH-interventional (p = 0.003) and versus the control (p = 0.004), as well as at timepoint 2 for ICH versus SAH-interventional (p = 0.002) and versus SAH-surgical (p = 0.013) with a lower EE in ICH patients. No significant differences between groups were found for EE at the other timepoints, or concerning urine urea and measurements of catecholamines in urine. In patients with SAH, ICH, and TBI, no meaningful differences in EE were detected compared to septic critically ill patients, except for a lower EE in ICH patients in the early phase.

The 3D in vitro Adrenoid cell model recapitulates the complexity of the adrenal gland

The crosstalk between the chromaffin and adrenocortical cells is essential for the endocrine activity of the adrenal glands. This interaction is also likely important for tumorigenesis and progression of adrenocortical cancer and pheochromocytoma. We developed a unique in vitro 3D model of the whole adrenal gland called Adrenoid consisting in adrenocortical carcinoma H295R and pheochromocytoma MTT cell lines. Adrenoids showed a round compact morphology with a growth rate significantly higher compared to MTT-spheroids. Confocal analysis of differential fluorescence staining of H295R and MTT cells demonstrated that H295R organized into small clusters inside Adrenoids dispersed in a core of MTT cells. Transmission electron microscopy confirmed the strict cell–cell interaction occurring between H295R and MTT cells in Adrenoids, which displayed ultrastructural features of more functional cells compared to the single cell type monolayer cultures. Adrenoid maintenance of the dual endocrine activity was demonstrated by the expression not only of cortical and chromaffin markers (steroidogenic factor 1, and chromogranin) but also by protein detection of the main enzymes involved in steroidogenesis (steroidogenic acute regulatory protein, and CYP11B1) and in catecholamine production (tyrosine hydroxylase and phenylethanolamine N-methyltransferase). Mass spectrometry detection of steroid hormones and liquid chromatography measurement of catecholamines confirmed Adrenoid functional activity. In conclusion, Adrenoids represent an innovative in vitro 3D-model that mimics the spatial and functional complexity of the adrenal gland, thus being a useful tool to investigate the crosstalk between the two endocrine components in the pathophysiology of this endocrine organ.

The Association Between Ventricular Fibrillation and Serum Catecholamine Levels.

Background and objective Epinephrine (Ep) is the first choice as a vasoconstrictor in cardiopulmonary resuscitation (CPR) for patients with cardiopulmonary arrest (CPA); however, the Ep concentration in the serum of CPA patients is still unclear. The aim of this study was to evaluate the association between serum Ep levels and achieving the return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients with ventricular fibrillation (VF). Methods This was a prospective, observational clinical study involving OHCA patients with VFtransferred to our hospital from July 2014 to July 2017. The measurement of serum catecholamines [Ep, norepinephrine (Nep), and dopamine (DOA)] and vasopressin [antidiuretic hormone (ADH)] levels was performed with blood samples obtained immediately upon patients' arrival at our hospital. Patients were classified into two groups: the ROSC(+) group and ROSC(-) group; the serum concentrations of catecholamines and ADH were compared between these two groups. Results The serum Ep and Nep levels were lower in the ROSC(+) group than those in the ROSC(-) group and the difference was statistically significant. On the other hand, no significant differences were found in serum DOA and ADH levels between the two groups. Conclusions The results of this study suggest that an increment in serum Ep levels does not promote achieving ROSC in OHCA patients with VF.

Greater anhedonia scores in healthy individuals are associated with less decline in 24-hour energy expenditure with fasting: Evidence for a link between behavioral traits and spendthrift phenotype

Obesity rates are increasing and affecting mental health. It is important to understand how behavioral traits such as anhedonia are associated with physiologic traits that may predict weight-change in clinical and non-clinical populations. We studied whether 24-hour energy expenditure (24hEE) changes with fasting and overfeeding are associated with anhedonia in a healthy cohort. We performed behavioral assessments (physical anhedonia scale (PAS) and inventory for depressive symptoms (IDS)) followed by measures of 24hEE and urinary catecholamines in a whole-room indirect calorimeter (respiratory chamber) during energy balance, and then randomly during fasting and 2 different overfeeding diets. Participants (n=98) were medically healthy, between 18 and 55 years of age, with normal glucose regulation and weight-stable 6 months before admission. Women were premenopausal and not pregnant. Higher PAS was significantly associated with lesser decrease in 24hEE with fasting and higher urinary catecholamine excretion rates – consistent with spendthrift metabolism. As IDS increased, the association between anhedonia and the change in 24hEE from energy balance to fasting decreased (B-values were lower for change in EE). Here, higher PAS scores may reflect the ability to respond with appropriate homeostatic reactions which balance energy needs. IDS scores blunting this response may explain how anhedonia and depression can lead to weight gain.

PD03-05 PHEOCHROMOCYTOMA: IS THERE A ROLE FOR ULTRASONOGRAPHY IN THE SCREENING OF ADRENAL MASS IN HYPERTENSIVE PATIENTS?

You have accessJournal of UrologyCME1 Apr 2023PD03-05 PHEOCHROMOCYTOMA: IS THERE A ROLE FOR ULTRASONOGRAPHY IN THE SCREENING OF ADRENAL MASS IN HYPERTENSIVE PATIENTS? Bruno Di Domenico, Gabriel Simoes, Caio de Oliveira, Luiz Gustavo Brandao, Helena Lima, and Marcelo Lima Bruno Di DomenicoBruno Di Domenico More articles by this author , Gabriel SimoesGabriel Simoes More articles by this author , Caio de OliveiraCaio de Oliveira More articles by this author , Luiz Gustavo BrandaoLuiz Gustavo Brandao More articles by this author , Helena LimaHelena Lima More articles by this author , and Marcelo LimaMarcelo Lima More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003220.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Pheochromocytomas are catecholamine-producing tumors derivate from chromaffin cells. Their clinical presentation is variable, with arterial hypertension being the most frequent finding and paroxysms (headache, palpitations, and sweating) the most characteristic. Diagnosis is clinical, through the measurement of serum and/or urinary metanephrines and imaging methods. The great challenge is how to identify these patients. It is estimated that 0.1% of hypertensive patients have pheochromocytomas. The hypertension of these patients can be treated surgically by laparoscopic adrenalectomies. The objective of the study was to evaluate the use of ultrasonography as a screening test for pheochromocytoma in hypertensive patients. METHODS: The medical records of all patients who underwent adrenalectomy between 1999 and 2020 were reviewed. Only the patients with a pathologic diagnosis of pheochromocytoma were selected. RESULTS: A total of 29 laparoscopic adrenalectomies were performed in 25 patients, including four bilateral adrenalectomies. The average patient age was 40.2 years old (range 18-66). Ultrasonography was the first exam performed on twenty-nine hypertensive patients in the imaging investigation that showed adrenal masses with a mean diameter of 2.8 cm. After that, all patients underwent computed tomography scanning or magnetic resonance imaging, and meta-[131I]iodobenzylguanidine (131I-MIBG) whole-body scintigraphy before adrenalectomy. Measurements of plasma metanephrines and/or urinary catecholamines were high in all patients. Although abdominal ultrasonography usually has low sensitivity and specificity, it was fundamental to identifying patients with adrenal mass and proceeding with the investigation. CONCLUSIONS: Ultrasonography was an efficient method for screening investigation of pheochromocytoma in the hypertensive population and is considered a safe, low-cost and fast imaging exam. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e76 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Bruno Di Domenico More articles by this author Gabriel Simoes More articles by this author Caio de Oliveira More articles by this author Luiz Gustavo Brandao More articles by this author Helena Lima More articles by this author Marcelo Lima More articles by this author Expand All Advertisement PDF downloadLoading ...

Clinical differences between small and large pheochromocytomas and paragangliomas.

Pheochromocytomas and paragangliomas (PPGLs) are neuroendocrine tumors, most of which are characterized by the release of catecholamine, and range in diameters from less than 1 cm to 10 cm or more. However, knowledge of the differences in clinical features between small and large PPGLs is insufficient. A retrospective analysis of patients with PPGLs treated at our institution between January 2018 and June 2020 was performed. The clinical characteristics of patients were investigated, and comparisons were made between patients with large and small PPGLs. The logistic regression analysis was used to confirm the risk factors, and the receiver operating characteristic curve was used to evaluate the diagnostic performance of the variables. Totally 263 patients were included, including 110 patients in small tumor group and 153 patients in large tumor group. There were more male patients in the large tumor group (p=0.009). More patients had hypertension (p<0.001) and diabetes (p=0.002) in the large tumor group. The 24-h urinary epinephrine (24hU-E) (p < 0.001) and 24-h urinary norepinephrine (24hU-NE) (p=0.002) concentrations were higher in the large tumor group. In terms of tumor location, adrenal-PPGLs were more frequent in the large tumor group (p<0.001). Multivariate logistic regression analysis showed that male sex [odds ratio (OR): 2.871, 95% confidence interval (CI): 1.444-5.711, p=0.003], 24hU-E concentrations (OR: 1.025, 95% CI:1.004-1.047, p=0.020), 24hU-NE concentrations (OR: 1.002, 95%CI: 1.001-1.004, p=0.045), and adrenal-PPGLs (OR: 2.510, 95% CI:1.256-5.018, p=0.009) were positive risk factors for large tumors. Taking above variables into the same model, the area under the receiver operating characteristic curve of the model for predicting the large tumor was 0.772 (95% CI: 0.706-0.834). After the short-term follow-up, there was no significant difference in tumor recurrence between the two groups (p=0.681). Significant differences in numerous clinical characteristics exist between large and small PPGLs. The male patients were more likely to be with large tumors, and such tumors were more likely to reside on the adrenal glands. Catecholamine measurements also help predict tumor size of PPGLs. Clinical decision-making will benefit from this information.

Biochemical analysis in congenital neuroblastoma.

The incidence of congenital neuroblastoma has increased in the recent years. The purpose of this study was to describe the clinical and biochemical characteristics of cases of congenital neuroblastoma diagnosed in our center. We report three cases of congenital neuroblastoma diagnosed in our hospital. In two, diagnosis was made prenatally, whereas the other case was detected in the immediate neonatal period. In the three cases, neuroblastoma was located in the abdominal region and exhibited elevated concentrations of catecholamines or their metabolites in single voided urine samples. Two tumors were classified as stage M, and one as stage L2. The N-MYC oncogen was not amplified in any of the cases studied. Histopathological analysis was favorable in the three cases. The tumor was resected in two patients. The three received chemotherapy. The measurement of catecholamines and their metabolites is essential in the diagnosis of neuroblastoma. When 24h urine cannot be collected, single voided urine can be used to calculate the index based on creatinine concentrations.

Plasmatic catecholamines after neuraxial labour analgesia: A randomised controlled trial comparing epidural versus combined spinal-epidural

BackgroundCombined spinal-epidural technique (CSE) for labour analgesia has been associated with fetal bradycardia and uterine hypertonia when compared with epidural analgesia (EA), possibly due to a decrease in epinephrine levels following neuraxial anaesthesia. However, there are no recent studies comparing plasmatic catecholamines levels between those two techniques. This study aimed to compare CSE versus EA regarding pre- and post-analgesia catecholamines levels, uterine tone and fetal heart rate. Patients and methodsRandomised clinical trial with 47 labouring patients divided in two groups (CSE and EA). Primary outcome was plasmatic catecholamine measurements before and after neuraxial block. Secondary outcomes were fetal heart rate changes, uterine hypertonia, hypotension episodes, pain relief and fetal outcomes. ResultsFor CSE group, the median decrease of plasmatic epinephrine was 0 pg/mL [(−) 480–(+) 41] and for norepinephrine was −21 pg/mL [(−) 2507–(+) 94]. For EA group, the median decrease for epinephrine was 0 pg/mL [(−) 326–(+) 15] and for norepinephrine was −5 pg/mL [(−) 190–(+76)]. There were no differences between groups (p = 0.96 and p = 0.63 for epinephrine and norepinephrine, respectively). There were no differences for secondary outcomes. ConclusionsThere was no evidence of a more significant decrease of catecholamines with CSE when compared with EA. Catecholamines decrease theory may not be valid for modern labour analgesia techniques.

Sympathetic and Vagal Nerve Activity in COPD: Pathophysiology, Presumed Determinants and Underappreciated Therapeutic Potential.

This article explains the comprehensive state of the art assessment of sympathetic (SNA) and vagal nerve activity recordings in humans and highlights the precise mechanisms mediating increased SNA and its corresponding presumed clinical determinants and therapeutic potential in the context of chronic obstructive pulmonary disease (COPD). It is known that patients with COPD exhibit increased muscle sympathetic nerve activity (MSNA), as measured directly using intraneural microelectrodes-the gold standard for evaluation of sympathetic outflow. However, the underlying physiological mechanisms responsible for the sympathoexcitation in COPD and its clinical relevance are less well understood. This may be related to the absence of a systematic approach to measure the increase in sympathetic activity and the lack of a comprehensive approach to assess the underlying mechanisms by which MSNA increases. The nature of sympathoexcitation can be dissected by distinguishing the heart rate increasing properties (heart rate and blood pressure variability) from the vasoconstrictive drive to the peripheral vasculature (measurement of catecholamines and MSNA) (Graphical Abstract Figure 1). Invasive assessment of MSNA to the point of single unit recordings with analysis of single postganglionic sympathetic firing, and hence SNA drive to the peripheral vasculature, is the gold standard for quantification of SNA in humans but is only available in a few centres worldwide because it is costly, time consuming and requires a high level of training. A broad picture of the underlying pathophysiological determinants of the increase in sympathetic outflow in COPD can only be determined if a combination of these tools are used. Various factors potentially determine SNA in COPD (Graphical Abstract Figure 1): Obstructive sleep apnoea (OSA) is highly prevalent in COPD, and leads to repeated bouts of upper airway obstructions with hypoxemia, causing repetitive arousals. This probably produces ongoing sympathoexcitation in the awake state, likely in the "blue bloater" phenotype, resulting in persistent vasoconstriction. Other variables likely describe a subset of COPD patients with increase of sympathetic drive to the heart, clinically likely in the "pink puffer" phenotype. Pharmacological treatment options of increased SNA in COPD could comprise beta blocker therapy. However, as opposed to systolic heart failure a similar beneficial effect of beta blocker therapy in COPD patients has not been shown. The point is made that although MSNA is undoubtedly increased in COPD (probably independently from concomitant cardiovascular disease), studies designed to determine clinical improvements during specific treatment will only be successful if they include adequate patient selection and translational state of the art assessment of SNA. This would ideally include intraneural recordings of MSNA and-as a future perspective-vagal nerve activity all of which should ideally be assessed both in the upright and in the supine position to also determine baroreflex function.

Intermittent Exercise at Lactate Threshold Induces Lower Acute Stress than Its Continuous Counterpart in Middle-to-Older Aged Men.

This study aimed to compare the degree of exhaustion and trophic effects between continuous exercise (CE) and intermittent exercise (IE) at lactate threshold (LT) intensity. Seven healthy men (age: 43–69 years) performed the following three experimental tests in a randomized crossover order: (1) control; (2) CE, performed as a 20-min of cycling at LT intensity; and (3) IE, performed as 20 sets of a one-min bout of cycling at LT intensity with a 30-s rest between every two sets. Heart rate (HR), blood lactate concentration (LA), rating of perceived exertion (RPE), catecholamines, cortisol, growth hormone, insulin-like growth factor (IGF)-1, and brain-derived neurotrophic factor (BDNF) were measured. The sampling timing in each test was as follows: 10 min before the onset of exercise, at the 25%, 50%, and 100% time points of exercise, and at 10 min after exercise. IE was found to be accompanied by a lower degree of exhaustion than CE in measures of HR, LA, RPE, catecholamines, and cortisol. In terms of trophic effects, both of IGF-1 and BDNF increased in CE, while a marginal increase of BDNF was observed in IE. The results indicated that IE induces lower stress than CE, but may not be effective for inducing trophic effects.

A case report on asymptomatic and biochemically silent pheochromocytoma in adrenal incidentaloma

Pheochromocytoma are rare tumours originating from the chromaffin tissue. The clinical manifestations are variable and are not specific as pheochromocytoma and often imitate other diseases. The diagnosis is established by measurement of catecholamines and their metabolites in urine or plasma and by radiographic studies for localisation. Surgical removal of the tumour is the preferred treatment. 45 years old female presented with adrenal incidentaloma of about 6.1×6.2×5.4 cm well defined heterogenous lesion with internal cystic areas seen in right adrenal region abutting upper pole of right kidney. Biochemical investigations for adrenal hormones including plasma aldosterones, cortisols, plasma metanephrines, 24 hrs urinary metanephrines and VMA were found to be normal. Proceeded with adrenelectomy and histopathology of the specimen revealed pheochromocytoma as diagnosis. Pheochromocytoma leads to high mortality and morbidity rates if untreated. Fractionised metanephrines and catecholamines in a 24 hrs urine analysis is the preferred biochemical test. In a biochemically silent pheochromocytoma imaging modalities are used to identify and locate the tumour. Adequete alpha and beta blockade should be ensured before tumour removal. Surgery is recommenced irrespective of size and normal biochemical study to prevent complications.

The Physical Condition of Deaf Primary School-Age Children and How to Correct it Using Physical Education Methods

The latest studies have shown that the parameters of physical development of children with hearing loss are attracting the attention of the scientific community. However, there are few studies that investigate changes in the physical condition of deaf children after improving physical education. The purpose of this work is to study the physical condition of deaf primary school-age children and develop a corrective program using methods of physical education. The study included 72 deaf children (to the experimental nEG=37 and the control group nCG=35) and 28 primary school-age children with normal hearing. The choice of research sample was random and the age of the children ranged from 6-10 years old. The physical condition of the schoolchildren was determined using a set of medical and biological methods: blood pressure measurement, heart rate calculation according to the electrocardiogram R-R interval, spirometry, electrocardiography, echocardiography, physical work capacity (PWC150) test, measurement of catecholamines using E. Matlina’s method, and anthropometry. The experimental physical education program consisted of a set of physical, breathing and posture exercises as well as physical games. Games were divided by complexity, level of perception, physical intensity, and impact on the body. It was determined that deafness negatively affects anthropometric indicators, the respiratory system, and the functional condition of the sympathoadrenal system, but does not affect the morpho-functional values of cardiac performance in primary school-age children. The study proves the effectiveness of adopting exercise programs based on physical games as a means of correcting the physical condition of deaf children. The study confirmed that the implementation of exercise programs for the correction of the physical condition of deaf primary school-age children by means of physical education based on physical games in the daily routine of special boarding schools has a positive effect on the children’s respiratory, cardiovascular and sympathoadrenal systems.

Cell therapy rescues aging-induced beta-1 adrenergic receptor and GRK2 dysfunction in the coronary microcirculation.

Our past study showed that coronary arterioles isolated from adipose-derived stromal vascular fraction (SVF)-treated rats showed amelioration of the age-related decrease in vasodilation to beta-adrenergic receptor (β-AR) agonist and improved β-AR-dependent coronary flow and microvascular function in a model of advanced age. We hypothesized that intravenously (i.v.) injected SVF improves coronary microvascular function in aged rats by re-establishing the equilibrium of the negative regulators of the internal adrenergic signaling cascade, G-protein receptor kinase 2 (GRK2) and G-alpha inhibitory (Gαi) proteins, back to youthful levels. Female Fischer-344 rats aged young (3 months, n = 24), old (24 months, n = 26), and old animals that received 1 × 107 green fluorescent protein (GFP+) SVF cells (O + SVF, n = 11) 4 weeks prior to sacrifice were utilized. Overnight urine was collected prior to sacrifice for catecholamine measurements. Cardiac samples were used for western blotting while coronary arterioles were isolated for pressure myography studies, immunofluorescence staining, and RNA sequencing. Coronary microvascular levels of the β1 adrenergic receptor are decreased with advancing age, but this decreased expression was rescued by SVF treatment. Aging led to a decrease in phosphorylated GRK2 in cardiomyocytes vs. young control with restoration of phosphorylation status by SVF. In vessels, there was no change in genetic transcription (RNAseq) or protein expression (immunofluorescence); however, inhibition of GRK2 (paroxetine) led to improved vasodilation to norepinephrine in the old control (OC) and O + SVF, indicating greater GRK2 functional inhibition of β1-AR in aging. SVF works to improve adrenergic-mediated vasodilation by restoring the β1-AR population and mitigating signal cascade inhibitors to improve vasodilation.

Re-evaluating the prevalence and factors characteristic of catecholamine secreting head and neck paragangliomas.

IntroductionWe sought to characterize the prevalence and factors characteristic of head and neck paragangliomas (HNPGLs) that secrete catecholamines to inform best practices for diagnosis and management.MethodsThis was a retrospective cohort study from 2000 to 2020 at a single‐institution tertiary centre. One‐hundred fifty‐two patients (182 tumours) with HNPGLs with at least one measurement of urine or plasma catecholamines and/or catecholamine metabolite levels prior to treatment were included. We differentiated and characterized those patients with increased level(s) of any nature and those with ‘clinically significant’ versus ‘clinically insignificant’ catecholamine production.ResultsThirty‐one (20.4%) patients had increased catecholamine and/or catecholamine metabolite levels. In most patients, these levels were ≤5‐fold above the upper limit of the reference range. Four of these 31 patients with increased levels were ultimately found to have an additional catecholamine secreting mediastinal paraganglioma or pheochromocytoma. Fourteen of 31 patients with HNPGL were deemed clinically significant secretors of catecholamines based on hyper‐adrenergic symptoms and/or profound levels of normetanephrines. This cohort was enriched for patients with paragangliomas of the carotid body or cervical sympathetic chain and those with SDHB genetic mutations. Ultimately, the prevalence of clinically significant catecholamine secreting Hangs was determined to be 9.2% and 7.7% based on a per‐patient and per‐tumour basis, respectively.ConclusionsThe rate of catecholamine excess in the current cohort of patients with HNPGLs was higher than previously reported. Neuroendocrine tumours of any anatomic subsite may secrete catecholamines, although not all increased laboratory level(s) are indicative of clinically significant catecholamine secretion causing symptoms or warranting adrenergic blockade.

Impaired Endothelial Function in Patients With Postural Tachycardia Syndrome.

The purpose of this study is to evaluate endothelial function in postural tachycardia syndrome (PoTS), a poorly understood chronic condition characterized by a state of consistent orthostatic tachycardia (delta heart rate ≥30 beats per minute) upon standing without orthostatic hypotension. Nineteen patients with PoTS and 9 healthy controls were studied after 3 days of a fixed, caffeine-free, normal sodium (150 milliequivalents/day) diet. All participants underwent autonomic function testing, including sinus arrhythmia, valsalva maneuver, hyperventilation, cold pressor, handgrip, and a standing test with catecholamine measurements, followed by endothelial function testing. We analyzed 3 measures of endothelial function: percent brachial flow-mediated dilation, digital pulsatile arterial tonometry, and postischemic percent leg blood flow. Flow-mediated dilation was significantly lower in patients with PoTS (6.23±3.54% for PoTS) than in healthy controls (10.6±4.37% for controls versus, P=0.014). PoTS and controls had similar digital pulsatile arterial tonometry (1.93±0.40 arbitrary units for controls versus 2.13±0.63 arbitrary units for PoTS). PoTS had similar but suggestive percent leg blood flow to controls (313±158% for PoTS versus 468±236% for controls, P=0.098). Patients with PoTS have significantly reduced flow-mediated dilation compared with healthy controls, suggesting that PoTS is characterized by endothelial dysfunction in conduit arteries. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01308099.

Head and neck paragangliomas in Norway, importance of genetics, updated diagnostic workup and treatment

Background Head and neck paragangliomas (HNPG) are rare and predominantly benign tumours, originating from the neuroendocrine paraganglionic system. A considerable proportion of HNPGs are hereditary, depending on the population. Aims/objectives The purpose of this study was to estimate the rate of hereditary HNPGs in a Scandinavian (Norwegian) population, report long-term experience with HNPGs and offer all patients diagnosed an updated follow-up, with emphasis on identifying hereditary HNPGs through genetic screening and multifocality by 18 F-2-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Material and methods Our study was a partly retrospective and partly prospective cohort study. It included patients with HNPG diagnosed at Oslo University Hospital (OUH), Rikshospitalet between 1990 and 2017. The patients underwent genetic testing, 18F-FDG PET/CT and measurement of catecholamines and meta-nephrines in the plasma. All resection specimens and biopsies were subjected to histopathological review. The genetic testing protocol consisted of testing for mutations in the following genes; SDHD, SDHB, SDHC, VHL and RET. Results Sixty-three patients were included in the study with a median age of 49 years (range 12 − 80). Cranial nerve dysfunction was present upon diagnosis in 13%, and 14% had multifocal paraganglioma (PG) disease. Fifty-six patients (89% of all the patients) underwent genetic testing, and 29% of these had a PG related mutation. Seven of the eight patients (88%) with multifocal PGs who underwent genetic testing had a mutation. In two of the patients, the 18F-FDG PET/CT revealed unknown and subclinical multifocality. Conclusions and significance This is the first study with systematic genetic workup and PET/CT imaging in Scandinavia of HNPG patients. The mutation rate was within the lower range reported in the literature with respect to HNPGs. Combining genetic testing and PET/CT imaging in the diagnostic workup of HNPGs is valuable.

A Neural Device with Individually Addressable Microelectrode Array Suitable for Simultaneous Measurement of Catecholamines: Fabrication and Characterization

Investigation of catecholamines (dopamine: DA, norepinephrine: NE and epinephrine EP) has been of importance of the crucial roles that these molecules play in neurological function and related diseases. Due to the similar chemical structures and oxidation potentials of these compounds, it has been a challenge to use simple electrochemical techniques to differentiate them in mixtures.1 Redox cycling is known to have the capability to differentiate between species based on the propensity of the compounds to diffuse to and produce an electrochemical response at the neighboring electrode.2 The oxidized species generated at an electrode (generator) can diffuse to neighboring electrodes held at a reducing potential (collector) that will yield the original species. This process can occur multiple times and can produce an amplified signal. If the oxidized form of the species is electrochemically inactive or inactivated through following chemical reactions, selectivity can be achieved for the electroactive molecules arriving at the collector. This can be the basis of separating and detecting species using redox cycling.The ECC’ mechanism of catecholamines takes place at different rates, in the order of EP > NE > DA, and can lead to differentiation based on the spatial distribution that is probed by the electrode array undergoing redox cycling.4 The purpose of our research is to study the fundamental electrochemical redox cycling behavior of DA, NE and EP. By understanding this behavior, it can then be determined whether their simultaneous detection in more complex samples will be feasible. We will report on miniaturized probes designed to meet requirements of a redox cycling approach for in vivo measurements. These are: 1) mechanical robustness for insertion in the brain without breakage or bending, 2) suitable dimensions to minimize damage to brain tissue and 3) suitable number and design of electrodes for optimal electrochemical performance. The substrate of the fabricated probe is an 80 µm thick SU-8 polymer. The shank is 100 µm wide and 6 mm long to reach deep areas of the rat’s striatum. The probe has an array of nine parallel gold electrodes each of which are 4µm wide with a gap of 4 µm in between.We will report the process, results, and challenges for design, fabrication, and implementation of a probe, suitable for neural studies. The characterization of the probe with a model compound and the results from CA measurements using redox cycling will be shown. We will discuss the next steps to improve the design of electrodes and experiments to achieve desirable limits of detection and sensitivity for in vivo measurements. References Hawley, M. D.; Tatawawadi, S. V.; Piekarski, S.; Adams, R. N. Journal of the American Chemical Society 1967, 89, 447-450.Hu, Mengjia; Fritsch, Ingrid. Analytical Chemistry 2015, 87, 2029−2032.Ciolkowski, E. L.; Maness, K. M.; Cahill, P. S.; Wightman, R. M.; Evans, D. H.; Fosset, B.; Amatore, C. Analytical Chemistry 1994, 66, 3611-3617.Ciolkowski, E. L.; Cooper, B. R.; Jankowski, J. A.; Jorgenson, J. W.; Wightman, R. M. Journal of the American Chemical Society 1992, 114, 2815-2821.

Electroless deposition of gold nanoparticles on carbon nanopipette electrode for electrochemical detection of catecholamines released from PC12 cells.

An electroless deposition method is reported for the fabrication of gold nanoparticles (Au NPs) modified carbon nanopipette electrode (CNPE) for sensitive electrochemical detection of dopamine (DA) in aqueous solution and catecholamines released from PC12 cells. A CNPE is fabricated by chemical vapor deposition with a carbon layer onto nanocapillary and then contacted with copper (Cu) wire. Cu wire of CNPE is able to serve as reducing agent for electroless deposition of Au NPs on the CNPE because the potential of Cu2+/Cu is more negative than that of AuCl4-/Au. The method is simple, time-saving, and environmentally friendly. Field emission scanning electron microscopy, energy-dispersive X-ray analysis, and electrochemical techniques confirm the successful fabrication of the Au NPs/CNPE. Furthermore, Au NPs/CNPE exhibits a good sensing activity for DA oxidation with a wide linear determination range of 0.1-8μmol/L and a low detection limit of 6nmol/L. The Au NPs/CNPE can be potentially applied for measurement of catecholamines released from PC12 cells. This present work is believed to be beneficial to the design and development of active metal catalysts onto nanoelectrodes for the detection of electroactive biological molecules in living cells.Graphical abstract An electroless deposition method was developed for the fabrication of gold nanoparticles onto the carbon nanopipette electrode, which was served as an enhanced electrochemical sensing platform for highly sensitive detection of dopamine with a linear range of 0.1-8μmol/L and a detection limit of 6nmol/L, and was also applied in the detection of catecholamines released from PC12 cells.

MON-LB035 Adrenal Venous Sampling in the Lateralization of Acth-Independent Cushing Syndrome With Bilateral Adrenal Masses: A Case With a 5-Year Follow-Up

Background Nearly 25% of adrenal Cushing syndrome (CS) patients with bilateral adrenal masses have unilateral hypercortisolism, making localization crucial for surgical planning. Since there is no standardized protocol for adrenal venous sampling (AVS) in lateralizing adrenal hypercortisolism, we share our experience with a case of CS with bilateral adrenal masses in which lateralization via AVS permitted unilateral adrenalectomy. Clinical Case A 59-year-old woman with hypertension, hyperlipidemia, and prediabetes was hospitalized for worsening back pain and hypertension. Her BMI was 26.5 kg/m2, BP 173/93 mmHg, HR 73/min, she was anxious, diaphoretic, and hirsute. Glucose was 118 mg/dL and HbA1c 6.6%. Abdominal computed tomography revealed a type B aortic dissection with both right (6.1 x 3.1cm and 3.6 x 2.4cm), and left (largest 1.7 cm) sided adrenal masses. Plasma and 24 hour-urine metanephrine, normetanephrine and catecholamines, as well as plasma renin and aldosterone levels, were normal. AM cortisol on three different occasions was 21.30, 20.70, and 21.30 mcg/dL. Midnight cortisol was 17.8 mcg/dL, and 24-hour urine free cortisol on two occasions was 163 mcg (urine volume 3.4L with creatinine 1.14) and 99.2 mcg (urine volume 1.15L). After 1mg dexamethasone her AM ACTH and cortisol were <5 and 18.70 mcg/dL, respectively. Preoperative AVS was performed and 8mg of dexamethasone was administered the night prior to ensure ACTH suppression during the procedure, and epinephrine was measured to ascertain adequate adrenal vein cannulation. Cortisol levels (in mcg/dL) from the common iliac, right and left adrenal veins were 14.7, 61.5, and 23.5 at 0 minute and 15.2, 61.0, and 22.7 at 2 minutes, respectively. Epinephrine levels (in pg/dL) from the common iliac, right and left adrenal veins were 42, 577, and 3225 at 0 minutes, and 46, 718, and 2989 at 2 minutes. Despite higher epinephrine levels from the left adrenal, the cortisol ratio of the right adrenal vein to peripheral vein was 4.18 with the right-to-left ratio of 2.59 and 2.68 at 0 and 2 minutes, suggesting hypersecretion of cortisol from the right adrenal gland. Unilateral right adrenalectomy revealed a 5.6 cm adrenal adenoma arising in a background of adrenal cortical hyperplasia. Morning postoperative cortisol was 2.2 mcg/dL. She was placed on hydrocortisone and tapered over a 10-month period with remission maintained for more than 3.5 years post-operatively. Conclusion This case demonstrates the safety, usefulness, and necessity, of AVS in localizing cortisol production when bilateral adrenal masses are present. In addition, this case suggests that the use of high dose dexamethasone and measurement of catecholamines may be helpful for more accurate interpretation. More data on AVS in CS patients with bilateral adrenal masses is needed so a well-validated and standardized CS-specific ACS protocol can be developed.