Adrenal Medullary Tissue Research Articles

The Immune Landscape of Pheochromocytoma and Paraganglioma: Current Advances and Perspectives.

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors derived from neural crest cells from adrenal medullary chromaffin tissues and extra-adrenal paraganglia, respectively. Although the current treatment for PPGLs is surgery, optimal treatment options for advanced and metastatic cases have been limited. Hence, understanding the role of the immune system in PPGL tumorigenesis can provide essential knowledge for the development of better therapeutic and tumor management strategies, especially for those with advanced and metastatic PPGLs. The first part of this review outlines the fundamental principles of the immune system and tumor microenvironment, and their role in cancer immunoediting, particularly emphasizing PPGLs. We focus on how the unique pathophysiology of PPGLs, such as their high molecular, biochemical, and imaging heterogeneity and production of several oncometabolites, creates a tumor-specific microenvironment and immunologically "cold" tumors. Thereafter, we discuss recently published studies related to the reclustering of PPGLs based on their immune signature. The second part of this review discusses future perspectives in PPGL management, including immunodiagnostic and promising immunotherapeutic approaches for converting "cold" tumors into immunologically active or "hot" tumors known for their better immunotherapy response and patient outcomes. Special emphasis is placed on potent immune-related imaging strategies and immune signatures that could be used for the reclassification, prognostication, and management of these tumors to improve patient care and prognosis. Furthermore, we introduce currently available immunotherapies and their possible combinations with other available therapies as an emerging treatment for PPGLs that targets hostile tumor environments.

Adaptive remodeling of the stimulus-secretion coupling: Lessons from the 'stressed' adrenal medulla.

Stress is part of our daily lives and good health in the modern world is offset by unhealthy lifestyle factors, including the deleterious consequences of stress and associated pathologies. Repeated and/or prolonged stress may disrupt the body homeostasis and thus threatens our lives. Adaptive processes that allow the organism to adapt to new environmental conditions and maintain its homeostasis are therefore crucial. The adrenal glands are major endocrine/neuroendocrine organs involved in the adaptive response of the body facing stressful situations. Upon stress episodes and in response to activation of the sympathetic nervous system, the first adrenal cells to be activated are the neuroendocrine chromaffin cells located in the medullary tissue of the adrenal gland. By releasing catecholamines (mainly epinephrine and to a lesser extent norepinephrine), adrenal chromaffin cells actively contribute to the development of adaptive mechanisms, in particular targeting the cardiovascular system and leading to appropriate adjustments of blood pressure and heart rate, as well as energy metabolism. Specifically, this chapter covers the current knowledge as to how the adrenal medullary tissue remodels in response to stress episodes, with special attention paid to chromaffin cell stimulus-secretion coupling. Adrenal stimulus-secretion coupling encompasses various elements taking place at both the molecular/cellular and tissular levels. Here, I focus on stress-driven changes in catecholamine biosynthesis, chromaffin cell excitability, synaptic neurotransmission and gap junctional communication. These signaling pathways undergo a collective and finely-tuned remodeling, contributing to appropriate catecholamine secretion and maintenance of body homeostasis in response to stress.

THU615 Rhabdomyolysis: A Rare Presentation Of Extra-adrenal Neuroendocrine Tumor

Abstract Disclosure: M. Saleem: None. S.M. Harman: None. J. Targovnik: None. Introduction:Paraganglioma is a rare neuroendocrine tumor (NET) arising from neural crest progenitors located outside of the adrenal gland and predominantly produce norepinephrine if functional. Here, we present a case of epinephrine producing extra-adrenal sympathetic neuroendocrine tumor. Case: A 66-year-old male with history of resistant hypertension (on amlodipine, lisinopril & metoprolol), hyperlipidemia & obesity presented for evaluation of possible pheochromocytoma/paraganglioma. He reported paroxysmal episodes of muscle spasm & paresthesia accompanied by hypertension (up to 200 mm Hg), palpitation, sweating & tremor lasting about 30-60 minutes. His CPK was elevated up to 428 U/L (NR 30-170 U/L) during those episodes. He reported 7 "major episodes" beginning ∼15 years prior to diagnosis, of which 3 occurred after major surgery with "small episodes" occurring monthly, exacerbated by sun & heat. Family history was remarkable for sister with recurrent rhabdomyolysis. Labs showed elevated epinephrine 181 pg/ml (normal <57), Dopamin 67 pg/ml (normal <10) and normal norepinephrine, significantly elevated 24h urine metanephrine 855 mcg/24h (normal 90-315), normal normetanephrine & dopamine levels. CT showed a 2.2 x 2.2 x 2.1 cm retroperitoneal mass with 84% absolute concerning for possible paraganglioma. FDG-PET and DOTATATE showed hypermetabolic activity (SUV max 6.63) and DOTATATE avid left retroperitoneal mass respectively. After discontinuing beta blocker and optimizing alpha blockage with doxazosin, the patient was referred to endocrine surgery and had a successful resection of this mass and left adrenalectomy. Pathology was consistent with chromaffin cell neoplasm and normal left adrenal gland. Patient had clinical and biochemical resolution of his symptoms post-op. Genetic counseling was done with pending results. Discussion: Pheochromocytomas & paragangliomas (PPGLs) are rare NET arising from chromaffin cells of the adrenal medulla or neural crest progenitors located outside of the adrenal gland, and predominantly produce epinephrine and norepinephrine respectively. Adrenal medullary tissue secretes epinephrine due to the activity of PNMT, induced by high local levels of cortisol from the adrenal cortex, which attaches a methyl radical to the catechol amino group. Extramedullary sympathetic secretory cells normally lack this enzyme and secrete norepinephrine. Thus, it is likely that the neoplasm we report had ectopic expression of this enzyme. PPGLs have variable signs and symptoms which mainly reflect the hemodynamic and metabolic actions of the catecholamines produced and secreted by the tumors with hypertension being the most common sign. Rhabdomyolysis is an unusual manifestation. This case is unique in that it presented as an extra-adrenal NET predominantly produced epinephrine and presented with rhabdomyolysis. Presentation: Thursday, June 15, 2023

Recording of Chromaffin Cell Electrical Activity In Situ in Acute Adrenal Slices.

Because catecholamines secretion mainly relies on the excitable nature of adrenal chromaffin cells, monitoring their electrical activity is an essential step in assessing the adrenal medullary tissue function. The difficult access to the gland in vivo allows only population activity to be recorded in this condition. In vitro preparations allow recordings of spontaneous or evoked activity from single or multiple cells, depending on the biological samples used (dissociated chromaffin cells versus adrenal tissue preparations). In this chapter, I provide a detailed description of the techniques used for electrophysiological recordings in rodent chromaffin cells in acute adrenal slices, using the patch-clamp technique. This methodology allows preservation of the tissue integrity and detection of action potentials, synaptic activity, and secretory events; it is thus suitable for the study of adrenomedullary activity-secretion coupling.

Restoring Function to Dopaminergic Neurons: Progress in the Development of Cell-Based Therapies for Parkinson’s Disease

There is escalating interest in cell-based therapies to restore lost dopamine inputs in Parkinson's disease. This is based upon the rationale that implanting dopamine progenitors into the striatum can potentially improve dopamine-responsive motor symptoms. A rich body of data describing clinical trials of previous cell transplantation exists. These have included multiple cell sources for transplantation including allogeneic (human embryonic mesencephalic tissue, retinal pigment epithelial cells) and autologous (carotid body, adrenal medullary tissue) cells, as well as xenotransplantation. However, there are multiple limitations related to these cell sources, including availability of adequate numbers of cells for transplant, heterogeneity within cells transplanted, imprecisely defined mechanisms of action, and poor cell survival after transplantation in some cases. Nonetheless, evidence has accrued from a subset of trials to support the rationale for such a regenerative approach. Recent rapid advances in stem cell technology may now overcome these prior limitations. For example, dopamine neuron precursor cells for transplant can be generated from induced pluripotent cells and human embryonic stem cells. The benefits of these innovative approaches include: the possibility of scalability; a high degree of quality control; and improved understanding of mechanisms of action with rigorous preclinical testing. In this review, we focus on the potential for cell-based therapies in Parkinson's disease to restore the function of dopaminergic neurons, we critically review previous attempts to harness such strategies, we discuss potential benefits and predicted limitations, and we address how previous roadblocks may be overcome to bring a cell-based approach to the clinic.

AQP2 as a diagnostic immunohistochemical marker for pheochromocytoma and/or paraganglioma.

Aquaporin2 (AQP2) is water channel protein that is widely distributed among mammalian tissues and plays a major role in water homeostasis. However, little is known about the expression and significance of AQP2 in human adrenal tumors. Thus, we performed an immunohistochemical investigation of AQP2 in normal and neoplastic adrenal tissues. AQP2 protein expression was investigated in 190 adrenal tumor patients using immunohistochemistry. Correlation between protein expression and clinicopathological features was statistically analyzed. We demonstrated immunopositivity for AQP2 in all adrenal medulla-originating tumors, including 96 pheochromocytomas (PCC), 7 metastatic pheochromocytomas (MPCC), and 10 neuroblastic tumors (NT) and 13 extra-adrenal paragangliomas (EAPGL). Whereas, APQ2 was absent from the 52 adrenal cortical adenomas and 2 adrenal cortical carcinomas examined. The 10 metastatic carcinomas examined in adrenal tissue were also negative for AQP2. In 82 (85%) of the 96 samples from patients with PCC, we studied the relationship between clinicopathologic factors and AQP2 expression and our findings suggested that the tumors that exhibited diffuse expression pattern of AQP2 were larger in diameter than those exhibiting focal (P=0.007) or mediate expression pattern (P=0.001). AQP2 protein is significantly expressed in normal adrenal medullary tissues and medullary tumors (including PCC, MPCC and NT) as well as EAPGL. AQP2 expression may indicate the origin of normal adrenal tissues, and its expression in cancer tissue may reflect the maintenance of water metabolism via AQP2 during tumorigenesis. AQP2 may serve as a valuable marker for the differential diagnosis of adrenal tumors.

Cholinergic and peptidergic neurotransmission in the adrenal medulla: A dynamic control of stimulus-secretion coupling.

Synaptic neurotransmission at the splanchnic nerve-chromaffin cell synapse is a chief element of the stimulus-secretion coupling in the adrenal medullary tissue, managing and regulating the secretion of catecholamines. Making the state of play more intricate than initially envisioned, the synaptic vesicles of nerve terminals innervating the medulla contain various compounds, including various neurotransmitters and neuropeptides. Under basal conditions associated with a low splanchnic nerve discharge rate, neurotransmission is ensured by the synaptic release of the primary neurotransmitter acetylcholine (ACh). Under sustained and repetitive stimulations of the splanchnic nerve, as triggered in response to stressors, the synaptic release of neuropeptides, such as the pituitary adenylate cyclase-activating polypeptide PACAP, supplants ACh release. The anatomical and functional changes that occur presynaptically at the preganglionic splanchnic nerve, combined with changes occurring postsynaptically at nicotinic acetylcholine receptors (nAChRs), confer the adrenomedullary synapses a solid and persistent aptitude to functional remodeling, from birth to aging. The present review focuses on the composite cholinergic and noncholinergic nature of neurotransmission occurring at the splanchnic nerve-chromaffin cell synapse and its remodeling in response to physiological or pathological stimuli.

Anti-GD2 antibody-containing immunotherapy postconsolidation therapy for people with high-risk neuroblastoma treated with autologous haematopoietic stem cell transplantation.

Neuroblastoma is a rare malignant disease that primarily affects children. The tumours mainly develop in the adrenal medullary tissue, and an abdominal mass is the most common presentation. High-risk disease is characterised by metastasis and other primary tumour characteristics resulting in increased risk for an adverse outcome. The GD2 carbohydrate antigen is expressed on the cell surface of neuroblastoma tumour cells and is thus a promising target for anti-GD2 antibody-containing immunotherapy. To assess the efficacy of anti-GD2 antibody-containing postconsolidation immunotherapy after high-dose chemotherapy (HDCT) and autologous haematopoietic stem cell transplantation (HSCT) compared to standard therapy after HDCT and autologous HSCT in people with high-risk neuroblastoma. Our primary outcomes were overall survival and treatment-related mortality. Our secondary outcomes were progression-free survival, event-free survival, early toxicity, late non-haematological toxicity, and health-related quality of life. We searched the electronic databases CENTRAL (2018, Issue 9), MEDLINE (PubMed), and Embase (Ovid) on 20 September 2018. We searched trial registries and conference proceedings on 28 October 2018. Further searches included reference lists of recent reviews and relevant articles as well as contacting experts in the field. There were no limits on publication year or language. Randomised controlled trials evaluating anti-GD2 antibody-containing immunotherapy after HDCT and autologous HSCT in people with high-risk neuroblastoma. Two review authors independently performed study selection, abstracted data on study and participant characteristics, and assessed risk of bias and GRADE. Any differences were resolved by discussion, with third-party arbitration unnecessary. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. We used the five GRADE considerations, that is study limitations, consistency of effect, imprecision, indirectness, and publication bias, to judge the quality of the evidence. We identified one randomised controlled trial that included 226 people with high-risk neuroblastoma who were pre-treated with autologous HSCT. The study randomised 113 participants to receive immunotherapy including isotretinoin, granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2, and ch14.18, a type of anti-GD2 antibody also known as dinutuximab. The study randomised another 113 participants to receive standard therapy including isotretinoin.The results on overall survival favoured the dinutuximab-containing immunotherapy group (hazard ratio (HR) 0.50, 95% confidence interval (CI) 0.31 to 0.80; P = 0.004). The results on event-free survival also favoured the dinutuximab-containing immunotherapy group (HR 0.61, 95% CI 0.41 to 0.92; P = 0.020). Randomised data on adverse events were not reported separately. The study did not report progression-free survival, late non-haematological toxicity, and health-related quality of life as separate endpoints. We graded the quality of the evidence as moderate. The evidence base favours dinutuximab-containing immunotherapy compared to standard therapy concerning overall survival and event-free survival in people with high-risk neuroblastoma pre-treated with autologous HSCT. Randomised data on adverse events are lacking, therefore more research is needed before definitive conclusions can be made regarding this outcome.

Cell Therapies for Parkinson's Disease.

Cell Therapies for Parkinson's Disease.

ANIMAL WELFARE AND POULTRY PRODUCTIVITY, A SHORT REVIEW

<p>The aim of this review is to present production alternatives based on animal welfare standards and good management practices on broiler and posture breeding. The excessive intensive production of eggs and chicken meat comes from the demand for food from a growing world population. And it has forgotten good animal husbandry and management practices. Which causes an imbalance of the sympathetic nervous system and adrenal medullary tissue that control the response of the poultry to stress, raising catecholamine levels inducing the release of glucose causing liver, heart and neuronal failure. these effects become visible due to the increase of diseases since the immune system is depressed, food intake decreases, oxytocin inhibition, which results in reduced reproduction and even death of the poultry. The incorporation of animal welfare standards imposed in intensive breeding, as well as, the production of eggs and meat under production systems (grazing) and backyard production become a sustainable alternative that maximizes the welfare of the poultry</p>

Monitoring the Secretory Behavior of the Rat Adrenal Medulla by High-Performance Liquid Chromatography-Based Catecholamine Assay from Slice Supernatants.

Catecholamine (CA) secretion from the adrenal medullary tissue is a key step of the adaptive response triggered by an organism to cope with stress. Whereas molecular and cellular secretory processes have been extensively studied at the single chromaffin cell level, data available for the whole gland level are much scarcer. We tackled this issue in rat by developing an easy to implement experimental strategy combining the adrenal acute slice supernatant collection with a high-performance liquid chromatography-based epinephrine and norepinephrine (NE) assay. This technique affords a convenient method for measuring basal and stimulated CA release from single acute slices, allowing thus to individually address the secretory function of the left and right glands. Our data point that the two glands are equally competent to secrete epinephrine and NE, exhibiting an equivalent epinephrine:NE ratio, both at rest and in response to a cholinergic stimulation. Nicotine is, however, more efficient than acetylcholine to evoke NE release. A pharmacological challenge with hexamethonium, an α3-containing nicotinic acetylcholine receptor antagonist, disclosed that epinephrine- and NE-secreting chromaffin cells distinctly expressed α3 nicotinic receptors, with a dominant contribution in NE cells. As such, beyond the novelty of CA assays from acute slice supernatants, our study contributes at refining the secretory behavior of the rat adrenal medullary tissue, and opens new perspectives for monitoring the release of other hormones and transmitters, especially those involved in the stress response.

Retinoic acid postconsolidation therapy for high-risk neuroblastoma patients treated with autologous haematopoietic stem cell transplantation.

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumours mainly develop in the adrenal medullary tissue, with an abdominal mass as the most common presentation. About 50% of patients have metastatic disease at diagnosis. The high-risk group is characterised by metastasis and other features that increase the risk of an adverse outcome. High-risk patients have a five-year event-free survival of less than 50%. Retinoic acid has been shown to inhibit growth of human neuroblastoma cells and has been considered as a potential candidate for improving the outcome of patients with high-risk neuroblastoma. This review is an update of a previously published Cochrane Review. To evaluate the efficacy and safety of additional retinoic acid as part of a postconsolidation therapy after high-dose chemotherapy (HDCT) followed by autologous haematopoietic stem cell transplantation (HSCT), compared to placebo retinoic acid or to no additional retinoic acid in people with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system). We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (2016, Issue 11), MEDLINE in PubMed (1946 to 24 November 2016), and Embase in Ovid (1947 to 24 November 2016). Further searches included trial registries (on 22 December 2016), conference proceedings (on 23 March 2017) and reference lists of recent reviews and relevant studies. We did not apply limits by publication year or languages. Randomised controlled trials (RCTs) evaluating additional retinoic acid after HDCT followed by HSCT for people with high-risk neuroblastoma compared to placebo retinoic acid or to no additional retinoic acid. Primary outcomes were overall survival and treatment-related mortality. Secondary outcomes were progression-free survival, event-free survival, early toxicity, late toxicity, and health-related quality of life. We used standard methodological procedures expected by Cochrane. The update search did not identify any additional studies. We identified one RCT that included people with high-risk neuroblastoma who received HDCT followed by autologous HSCT (N = 98) after a first random allocation and who received retinoic acid (13-cis-retinoic acid; N = 50) or no further therapy (N = 48) after a second random allocation. These 98 participants had no progressive disease after HDCT followed by autologous HSCT. There was no clear evidence of difference between the treatment groups either in overall survival (hazard ratio (HR) 0.87, 95% confidence interval (CI) 0.46 to 1.63; one trial; P = 0.66) or in event-free survival (HR 0.86, 95% CI 0.50 to 1.49; one trial; P = 0.59). We calculated the HR values using the complete follow-up period of the trial. The study also reported overall survival estimates at a fixed point in time. At the time point of five years, the survival estimate was reported to be 59% for the retinoic acid group and 41% for the no-further-therapy group (P value not reported). We did not identify results for treatment-related mortality, progression-free survival, early or late toxicity, or health-related quality of life. We could not rule out the possible presence of selection bias, performance bias, attrition bias, and other bias. We judged the evidence to be of low quality for overall survival and event-free survival, downgraded because of study limitations and imprecision. We identified one RCT that evaluated additional retinoic acid as part of a postconsolidation therapy after HDCT followed by autologous HSCT versus no further therapy in people with high-risk neuroblastoma. There was no clear evidence of a difference in overall survival and event-free survival between the treatment alternatives. This could be the result of low power. Information on other outcomes was not available. This trial was performed in the 1990s, since when many changes in treatment and risk classification have occurred. Based on the currently available evidence, we are therefore uncertain about the effects of retinoic acid in people with high-risk neuroblastoma. More research is needed for a definitive conclusion.

Rapid COJEC versus standard induction therapies for high-risk neuroblastoma.

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumors mainly develop in the adrenal medullary tissue and an abdominal mass is the most common presentation. The high-risk group is characterized by metastasis and other characteristics that increase the risk for an adverse outcome. In the rapid COJEC induction schedule, higher single doses of selected drugs than standard induction schedules are administered over a substantially shorter treatment period, with shorter intervals between cycles. Shorter intervals and higher doses increase the dose intensity of chemotherapy and might improve survival. The aim of this study was to evaluate the efficacy and adverse events of the rapid COJEC induction schedule as compared to standard induction schedules in patients with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system). Outcomes of interest were complete response, early toxicity and treatment-related mortality as primary endpoints and overall survival, progression- and event-free survival, late non-hematological toxicity, and health-related quality of life as secondary endpoints. We searched the electronic databases CENTRAL (2014, Issue 11), MEDLINE (PubMed), and EMBASE (Ovid) for articles from inception to 11 November 2014. Further searches included trial registries, conference proceedings, and reference lists of recent reviews and relevant articles. We did not apply limits on publication year or languages. Randomized controlled trials evaluating the rapid COJEC induction schedule for high-risk neuroblastoma patients compared to standard induction schedules. Two review authors performed study selection, abstracted data on study and patient characteristics, and assessed risk of bias independently. We resolved differences by discussion or by appeal to a third review author. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. We used the five GRADE considerations, study limitations, consistency of effect, imprecision, indirectness, and publication bias, to judge the quality of the evidence. We downgraded for risk of bias and imprecision We identified one randomized controlled trial (CCLG-ENSG-5) that included 262 patients with high-risk neuroblastoma who were randomized to receive either rapid COJEC (N = 130) or standard OPEC/COJEC (N = 132) induction chemotherapy. We graded the evidence as low quality; we downgraded for risk of bias and imprecision.There was no clear evidence of a difference between the treatment groups in complete response (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.71 to 1.38), treatment-related mortality (RR 1.21, 95% CI 0.33 to 4.39), overall survival (hazard ratio (HR) 0.83, 95% CI 0.63 to 1.10), and event-free survival (HR 0.86, 95% CI 0.65 to 1.13). We calculated the HRs using the complete follow-up period of the trial.Febrile neutropenia (two or more episodes), proven fungal infections, septicemia (one or more episodes), gastrointestinal toxicity (grade 3 or 4), renal toxicity (glomerular filtration rate < 80 ml/min per body surface area of 1.73 m(2)), neurological toxicity (grade 3 or 4), and ototoxicity (Brock grade 2 to 4) were addressed as early toxicities (during pre-operative chemotherapy). For febrile neutropenia, septicemia, and renal toxicity, a statistically significant difference in favor of the standard treatment arm was identified; for all other early toxicities no clear evidence of a difference between treatment groups was identified. With regard to late non-hematological toxicities (median follow-up 12.7 years; range 6.9 to 16.5 years), the study provided data on any complication, renal toxicity (glomerular filtration rate < 80 ml/min per body surface area of 1.73m(2)), ototoxicity (Brock grade 1 to 4), endocrine complications, neurocognitive complications (i.e. behavioral, speech, or learning difficulties), and second malignancies. For endocrine complications and neurocognitive complications, a statistically significant difference in favor of the rapid COJEC arm was found; for all other late non-hematological toxicities no clear evidence of a difference between treatment groups was identified.Data on progression-free survival and health-related quality of life were not reported. We identified one randomized controlled trial that evaluated rapid COJEC versus standard induction therapy in patients with high-risk neuroblastoma. No clear evidence of a difference in complete response, treatment-related mortality, overall survival, and event-free survival between the treatment alternatives was found. This could be the result of low power or too short a follow-up period. Results of both early and late toxicities were ambiguous. Information on progression-free survival and health-related quality of life were not available. This trial was performed in the 1990s. Since then, many changes in, for example, treatment and risk classification have occurred. Therefore, based on the currently available evidence, we are uncertain about the effects of rapid COJEC and standard induction therapy in patients with high-risk neuroblastoma. More research is needed for a definitive conclusion.

Retinoic acid post consolidation therapy for high-risk neuroblastoma patients treated with autologous hematopoietic stem cell transplantation.

Neuroblastoma is a rare malignant disease and mainly affects infants and very young children. The tumors mainly develop in the adrenal medullary tissue and an abdominal mass is the most common presentation. About 50% of patients have metastatic disease at diagnosis. The high-risk group is characterized by metastasis and other characteristics that increase the risk for an adverse outcome. High-risk patients have a five-year event-free survival of less than 50%. Retinoic acid has been shown to inhibit growth of human neuroblastoma cells and has been considered as a potential candidate for improving the outcome of patients with high-risk neuroblastoma. To evaluate efficacy and adverse events of retinoic acid after consolidation with high-dose chemotherapy followed by bone marrow transplantation as compared to placebo or no therapy in patients with high-risk neuroblastoma (as defined by the International Neuroblastoma Risk Group (INRG) classification system). Our outcomes of interest were overall survival and treatment-related mortality as primary outcomes; and progression- and event-free survival, early and late toxicity, and health-related quality of life as secondary outcomes. We searched the electronic databases CENTRAL (2014, Issue 8) on The Cochrane Library, MEDLINE (1946 to October 2014), and EMBASE (1947 to October 2014). Further searches included trial registries, conference proceedings, and reference lists of recent reviews and relevant articles. We did not apply limits on publication year or languages. Randomized controlled trials (RCTs) evaluating retinoic acid post consolidation therapy for high-risk neuroblastoma patients treated with autologous hematopoietic stem cell transplantation (HSCT) compared to placebo or no further treatment. Two review authors performed the study selection, extracted the data on study and patient characteristics and assessed the risk of bias independently. We resolved differences by discussion or by appeal to a third review author. We performed analyses according to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions. The authors of the included study did not report the results specifically for the treatment groups relevant to this Cochrane Review. Therefore, we deduced the appropriate survival data from the published survival curves and calculated a hazard ratio (HR) based on the deduced data. We identified one RCT (CCG-3891) that included patients with high-risk neuroblastoma who received high-dose chemotherapy followed by autologous HSCT (N = 98) after a first random allocation and who received retinoic acid (13-cis-retinoic acid; N = 50) or no further therapy (N = 48) after a subsequent second random allocation. These patients had no progressive disease after consolidation therapy. There was no clear evidence of difference between the treatment groups in both overall survival (HR 0.87, 95% CI 0.46 to 1.63; one trial; P = 0.66, low quality of evidence) and event-free survival (HR 0.86, 95% CI 0.50 to 1.49; one trial; P = 0.59, low quality of evidence). We calculated these HR values using the complete follow-up period of the trial. The study also reported five-year overall survival rates: 59% for the retinoic acid group and 41% for the no further therapy group (P value not reported). We did not identify results for treatment-related mortality, progression-free survival, early or late toxicity, or health-related quality of life. Also, we could not rule out the possible presence of selection bias, performance bias, attrition bias, and other bias. We identified one RCT that evaluated retinoic acid as a consolidation therapy versus no further therapy after high-dose chemotherapy followed by bone-marrow transplantation in patients with high-risk neuroblastoma. The difference in overall survival and event-free survival between both treatment alternatives was not statistically significantly different. This could be the result of low power. Information on other outcomes was not available. This trial was performed in the 1990s, since then many changes in for example treatment and risk classification have occurred. Therefore, based on the currently available evidence, we are uncertain about the effects of retinoic acid in patients with high-risk neuroblastoma. More research is needed for a definitive conclusion.

Low-intensity aerobic exercise mitigates exercise-induced bronchoconstriction by improving the function of adrenal medullary chromaffin cells in asthmatic rats.

Exercise is one of the most common triggers of bronchoconstriction in patients with asthma. The low levels of circulating epinephrine produced by the adrenal medullary chromaffin cells (AMCCs) are associated with exercise-induced bronchoconstriction (EIB) in asthmatics. In the present study, we tested the hypothesis that low-intensity aerobic exercise may ameliorate EIB using a rat model of asthma. Male Sprague-Dawley rats at 7 weeks of age, sensitized with ovalbumin or treated with saline, were subjected to low or moderate exercise training (50 or 75% of maximum velocity) for one hour in a treadmill 30 min after ovalbumin or saline inhalation. The exercise capacity, airway responsiveness, lung morphology, the morphological changes and endocrine function of AMCCs were measured in both groups of rats after exercise training for 6 weeks. Either low-intensity or moderate-intensity exercise mitigated EIB and increased exercise capacity in ovalbumin-sensitized (asthmatic) rats. Low-intensity aerobic exercise reduced the vacuolar degeneration degrees, lipid contents, neuronal peripherin and neurofilament-68 expression, demolished neurites, but increased the chromaffin granule density, endocrine chromogranin A and phenylethanolamine N-methyltransferase expression in the adrenal medullary tissues, accompanied by increased levels of circulating epinephrine and corticosterone, but decreased nerve growth factor in asthmatic rats. Finally, low-intensity aerobic exercise significantly reduced the relative levels of phosphorylated extracellular signal-regulated kinase and phosphorylated cAMP responsive element-binding protein and the relative mRNA expression levels of downstream molecules, including c-FOS and c-JUN in the adrenal medullary of asthmatic rats. We suggest that low-intensity aerobic exercise improves the endocrine dysfunction of AMCCs and mitigates EIB.

Cytoplasmic OCT4 staining is a sensitive marker of neuroendocrine differentiation

Previous studies by the authors have described a novel cytoplasmic staining pattern with OCT4 in normal adrenal medullary tissue and in paragangliomas. We aimed to determine if this type of staining is found in other neuroendocrine tissues by examining a broad range of neuroendocrine tumors. Fifty neuroendocrine tumors of various grades and primary organ sites were selected. All cases were immunostained with OCT4 and Ki-67. OCT4 reactivity was then scored for intensity (0-3+) and extent (0-3+). Ki-67 proliferation index was scored as a percentage of total tumor cells. Immunoelectron microscopy was performed to determine precise location of antibody binding within cells. Immunoreactivity was seen in 26 (96%) of 27 cases of carcinoid tumors. The same type of strong staining was seen in 4 (67%) of 6 moderately differentiated neuroendocrine tumors. Only 2 (12%) of 17 poorly differentiated neuroendocrine tumors showed similar staining. A strong, inverse correlation was seen with OCT4 and Ki-67 index. Immunoelectron microscopy showed binding of OCT4 antibody to neurosecretory granules. Cytoplasmic staining of OCT4 is a sensitive marker of neuroendocrine differentiation that has yet to be described in any other tissue or tumor type. These findings show that this antibody has a high affinity for well- to moderately differentiated neuroendocrine tumors. Although comparative studies with other markers and a more extensive analysis of other tissue types are necessary, cytoplasmic staining of OCT4 may prove to be a useful immunostain in the diagnosis of neuroendocrine tumors.

Functional Chromaffin Cell Plasticity in Response to Stress: Focus on Nicotinic, Gap Junction, and Voltage-Gated Ca2+ Channels

An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca(2+) signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca(2+) channels that are directly involved in Ca(2+)-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition.

Modulation by endogenously released ATP and opioids of chromaffin cell calcium channels in mouse adrenal slices

Modulation of high-threshold voltage-dependent calcium channels by neurotransmitters has been the subject of numerous studies in cultures of neurons and chromaffin cells. However, no studies on such modulation exist in chromaffin cells in their natural environment, the intact adrenal medullary tissue. Here we performed such a study in voltage-clamped chromaffin cells of freshly prepared mouse adrenal slices under the whole cell configuration of the patch-clamp technique. The subcomponents of the whole cell inward Ca(2+) current (I(Ca)) accounted for 49% for L-, 28% for N-, and 36% for P/Q-type channels. T-type Ca(2+) channels or residual R-type Ca(2+) currents were not seen. However, under the perforated-patch configuration, 20% of I(Ca) accounted for a toxin-resistant R-type Ca(2+) current. Exogenously applied ATP and methionine-enkephalin (Met-enk) inhibited I(Ca) by 33%. Stop-flow and Ca(2+) replacement by Ba(2+), which favored the release of endogenous ATP and opioids, also inhibited I(Ca), with no changes in activation or inactivation kinetics. This inhibition was partially voltage independent and insensitive to prepulse facilitation. Furthermore, in about half of the cells, suramin and naloxone augmented I(Ca) in the absence of exogenous application of ATP/Met-enk. No additional modulation of I(Ca) was obtained after bath application of exogenous ATP and opioids to these already inhibited cells. Augmentation of I(Ca) was also seen upon intracellular dialysis of guanosine 5'-[β-thio]diphosphate (GDPβS), indicating the existence in the intact slice of a tonic inhibition of I(Ca) in resting conditions. These results suggest that in the intact adrenal tissue a tonic inhibition of I(Ca) exists, mediated by purinergic and opiate receptors.

Developmental and Stress-Induced Remodeling of Cell–Cell Communication in the Adrenal Medullary Tissue

The adrenal medullary tissue contributes to maintain body homeostasis in reaction to stressful environmental changes via the release of catecholamines into the blood circulation in response to splanchnic nerve activation. Accordingly, chromaffin cell stimulus-secretion coupling undergoes temporally restricted periods of anatomo- functional remodeling in response to prevailing hormonal requirements of the organism. The postnatal development of the adrenal medulla and response to stress are remarkable physiological situations in which the stimulus- secretion coupling is critically affected. Catecholamine secretion from rat chromaffin cells is under a dual control involving an incoming initial command arising from the sympathetic nervous system that releases acetylcholine at the splanchnic nerve terminal-chromaffin cell synapses and a local gap junction-mediated intercellular communication. Interestingly, these two communication pathways are functionally interconnected within the gland and exhibit coordinated plasticity mechanisms. This article reviews the physiological and molecular evidence that the adrenal medullary tissue displays anatomical and functional adaptative remodeling of cell–cell communications upon physiological (postnatal development) and/or physiopathological (stress) situations associated with specific needs in circulating catecholamine levels.

Functional Characterization of α9-Containing Cholinergic Nicotinic Receptors in the Rat Adrenal Medulla: Implication in Stress-Induced Functional Plasticity

An increase in circulating adrenal catecholamine levels constitutes one of the mechanisms whereby organisms cope with stress. Accordingly, stimulus-secretion coupling within the stressed adrenal medullary tissue undergoes persistent remodeling. In particular, cholinergic synaptic neurotransmission between splanchnic nerve terminals and chromaffin cells is upregulated in stressed rats. Since synaptic transmission is mainly supported by activation of postsynaptic neuronal acetylcholine nicotinic receptors (nAChRs), we focused our study on the role of alpha9-containing nAChRs, which have been recently described in chromaffin cells. Taking advantage of their specific blockade by the alpha-conotoxin RgIA (alpha-RgIA), we unveil novel functional roles for these receptors in the stimulus-secretion coupling of the medulla. First, we show that in rat acute adrenal slices, alpha9-containing nAChRs codistribute with synaptophysin and significantly contribute to EPSCs. Second, we show that these receptors are involved in the tonic inhibitory control exerted by cholinergic activity on gap junctional coupling between chromaffin cells, as evidenced by an increased Lucifer yellow diffusion within the medulla in alpha-RgIA-treated slices. Third, we unexpectedly found that alpha9-containing nAChRs dominantly (>70%) contribute to acetylcholine-induced current in cold-stressed rats, whereas alpha3 nAChRs are the main contributing channels in unstressed animals. Consistently, expression levels of alpha9 nAChR transcript and protein are overexpressed in cold-stressed rats. As a functional relevance, we propose that upregulation of alpha9-containing nAChR channels and ensuing dominant contribution in cholinergic signaling may be one of the mechanisms whereby adrenal medullary tissue appropriately adapts to increased splanchnic nerve electrical discharges occurring in stressful situations.