History and Recent Progress in Carotid Body Studies.

This chapter describes the history of the carotid body (CB) and the subsequent research on its structure and function. The chronological development of ideas about its anatomical structure as a ganglion, the first descriptions of its glandular nature as a ball of highly vascular tissue (glomus), the discovery of its neural crest origin and relevant embryological views as a true paraganglion toward a more conclusive understanding of its sensory nature as a chemoreceptor for chemical changes in blood have been consistently demonstrated. The knowledge of the CB neurochemistry, physiology and pathophysiology has progressed immensely in the past century and a large and compelling body of evidence for the presence of a neurogenic niche in the CB has accumulated over the last two decades, thus underlying its function and possibility for the development of cell replacement therapies.

Seasoned with “salt and pepper”: The taste of head and neck Paragangliomas

Paraganglia of the Gallbladder: An Underrecognized Incidental Finding and Potential Diagnostic Pitfall.

CONTEXT.­: The identification of paraganglia (PG) in the gallbladder (GB) is infrequent, and easily overlooked as it is not something routinely reported. Occasionally they may be misinterpreted as neoplastic cells, such as low-grade carcinomas, germ cell tumors, or because of their close resemblance to neuroendocrine cells, as low-grade neuroendocrine neoplasms. OBJECTIVE.­: To evaluate the incidence and histological features of PG of the GB in patients that underwent cholecystectomy, and discuss the potential misinterpretation of these benign structures as clusters of neoplastic cells. DESIGN.­: A retrospective study of cholecystectomy specimens performed during a 6-month period were reviewed for identification of PG. Immunohistochemical studies for chromogranin, synaptophysin, S100, and cytokeratin AE1/AE3 were performed in selected cases. RESULTS.­: A total of 365 GBs were reviewed and in 16 cases (4.4%) PG was identified within the subserosal connective tissue of the GB wall or cystic duct adjacent to small capillaries, nerves, and ganglia. They consisted of well-demarcated, lobular structures ranging in size from 0.2 to 0.5 cm, which were predominantly composed of chief cells, with strong expression for chromogranin and synaptophysin and negative CKAE1/AE3, and a minor component of S100-positive sustentacular cells. CONCLUSIONS.­: PG is an uncommon finding with a prevalence of 4.4% in our study. Awareness of their location, histologic features, and immunohistochemical profile may help practicing pathologists to confirm their benign nature, avoid a misdiagnosis of malignancy, and prevent unnecessary diagnostic work-up and treatment.

Approach to the Patient: Perioperative Management of the Patient with Pheochromocytoma or Sympathetic Paraganglioma.

Pheochromocytomas and sympathetic paraganglioma (PPGL) are rare chromaffin cell tumors originating in the adrenal medulla and sympathetic paraganglia, respectively, which share the capacity to synthesize and release catecholamines. The incidence of PPGL has increased in recent years. Surgical resection is the only curative treatment for PPGL. Management of patients with PPGL is complex and should be done by a specialized multidisciplinary team in centers with broad expertise. Surgical resection of a PPGL is a high-risk procedure for which optimal pretreatment with antihypertensive drugs is required in combination with state-of-the-art surgical procedures and anesthesiological techniques. In this article we discuss the underlying evidence and the pros and cons of presurgical medical preparation. Finally, the areas of uncertainty and controversies in this field are addressed.

Metabolomics Analyses of 14 Classical Neurotransmitters by GC-TOF with LC-MS Illustrates Secretion of 9 Cell-Cell Signaling Molecules from Sympathoadrenal Chromaffin Cells in the Presence of Lithium.

The classical small molecule neurotransmitters are essential for cell-cell signaling in the nervous system for regulation of behaviors and physiological functions. Metabolomics approaches are ideal for quantitative analyses of neurotransmitter profiles but have not yet been achieved for the repertoire of 14 classical neurotransmitters. Therefore, this study developed targeted metabolomics analyses by full scan gas chromatography/time-of-flight mass spectrometry (GC-TOF) and hydrophilic interaction chromatography-QTRAP mass spectrometry (HILIC-MS/MS) operated in positive ionization mode for identification and quantitation of 14 neurotransmitters consisting of acetylcholine, adenosine, anandamide, aspartate, dopamine, epinephrine, GABA, glutamate, glycine, histamine, melatonin, norepinephrine, serine, and serotonin. GC-TOF represents a new metabolomics method for neurotransmitter analyses. Sensitive measurements of 11 neurotransmitters were achieved by GC-TOF, and three neurotransmitters were analyzed by LC-MS/MS (acetylcholine, anandamide, and melatonin). The limits of detection (LOD) and limits of quantitation (LOQ) were assessed for linearity for GC-TOF and LC-MS/MS protocols. In neurotransmitter-containing dense core secretory vesicles of adrenal medulla, known as chromaffin granules (CG), metabolomics measured the concentrations of 9 neurotransmitters consisting of the catecholamines dopamine, norepinephrine, and epinephrine, combined with glutamate, serotonin, adenosine, aspartate, glycine, and serine. The CG neurotransmitters were constitutively secreted from sympathoadrenal chromaffin cells in culture. Nicotine- and KCl-stimulated release of the catecholamines and adenosine. Lithium, a drug used for the treatment of bipolar disorder, decreased the constitutive secretion of dopamine and norepinephrine and decreased nicotine-stimulated secretion of epinephrine. Lithium had no effect on other secreted neurotransmitters. Overall, the newly developed GC-TOF with LC-MS/MS metabolomics methods for analyses of 14 neurotransmitters will benefit investigations of neurotransmitter regulation in biological systems and in human disease conditions related to drug treatments.

The Origin of a New Progenitor Stem Cell Group in Human Development.

The observation of two precursor groups of the early stem cells (Groups I and II) leads to the realization that a first amount of fetal stem cells (Group I) migrate from the AMG (Aortal-Mesonephric-Gonadal)-region into the aorta and its branching vessels. A second group (Group II) gains quite a new significance during human development. This group presents a specific developmental step which is found only in the human. This continuation of the early development along a different way indicates a general alteration of the stem cell biology. This changed process in the stem cell scene dominates the further development of the human stem cells. It remains unclear where this phylogenetic step first appears. By far not all advanced mammals show this second group of stem cells and their axonal migration. Essentially only primates seem to be involved in this special development.

Caracterización Epidemiológica de los Pacientes con Diagnóstco de Glomus Carotdeo Sometdos a Resección en la Unidad de Cirugía Cardiovascular de Guatemala / Epidemiological Characterization of patients with carotid body tumors who underwent resection in the vascular unit in Guatemala (UNICAR)

Introducción: Los tumores del cuerpo carotideo son tumores infrecuentes, generalmente benignos y muy vascularizados, por lo que su resección es un reto para el cirujano. El objetivo de este estudio es realizar una caracterización epidemiológica de los pacientes con glomus carotideo operados en la Unidad de Cirugía Cardiovascular de Guatemala (UNICAR) Metodología: El estudio fue descriptvo retrospectivo analizando los registros clínicos de todos los pacientes sometidos a resección de glomus carotideo en UNICAR de enero de 2,002 a diciembre de 2,015. Resultados: Se documentaron 17 pacientes a quienes se les realizo resección de glomus en la unidad, de los cuales 1 expediente no fue posible analizar porque no se encontró en el archivo. El 93% de los pacientes fueron de sexo femenino lo cual está descrito que es el género más afectado. La altitud es característica de esta patología ya que el 93%, 15 de los 16 venían de una altura mayor de los 1,500 mts sobre el nivel del mar. No se pudo determinar la etnia como factor de riesgo ya que el 50% de los pacientes fueron de etnia indígena y el 50% de etnia ladina. Se obtuvo un caso de herencia familiar ya que tanto la abuela como la nieta presentaron glomus carotideo. Las biopsias que se documentaron fueron solamente en 5 pero pensamos que hay un subregistro ya que consultando con los especialistas estás pudieron haber sido más. Conclusiones: El Glomus Carotideo es una patología poco frecuente, sin embargo, debe ser tratado en unidades especializadas vasculares debido a su compleja resección y el importante riesgo de sangrado. En este estudio se logró caracterizar epidemiológicamente a los pacientes, coincidiendo con lo reportado en la literatura mundial.

Background: Carotid body tumors are uncommon, generally benign, hypervascular turmors; resection is a challenge for surgeons. The aim of this study is to characterize patents with carotid body tumors who underwent resection at the Cardiovascular Surgical Unit in Guatemala (UNICAR) Methods and Results: There were a total of 17 patents in this descriptve and retrospectve trial who underwent resection of carotid body tumor during 2002 to 2015, but we only had access to 16 of the patents clinical records. 93% were female patents, this is the same as reported in other trials being women more affected than men. Altitude of more than 1,500 m from sea level was present in 93% of the patents. This is remarkable due to the country's geography where there can be in some department's altitudes from 0 m at sea level to as high as 2,800 m. Their background in race speaking isn't related to the presence of this pathology, 50% were indigenous and 50% were ladinos. There was only one case of family related heritage where grandmother and granddaughter had a carotid body tumor resection. Previous biopsy was only recorded in 5 clinical records but we think this can be a sub registry due to the experience of some of the surgeons who said most of them had previous scars and it made the resection more difficult. Conclusions: Carotid body tumors are rare in presentation and they must be treated in a specialized vascular unit due to its complex resection and hemorrhage risk.

Malignant paraganglioma of the mesentery: a case report and review of literature.

Paragangliomas represent only 10% of chromaffin tissue tumors and those arising from the mesentery seem to be a rare occurrence. We report a case of a 55 year old man in whom an abdominal mass was discovered fortuitously by ultrasonography during a routine health exam. He presented occasional heart palpitations and diaphoresis as well as a well-demarcated mass upon abdominal physical examination. CT scan revealed a solid polylobulated mass in the right lower quadrant. Exploration laparotomy revealed a voluminous multi-nodular tumoral mass, which contained hemorrhagic spots. Histopathological studies confirmed the presence of a paraganglioma. The excision of the mass as well as the surrounding intestine and mesentery also revealed two lymphatic metastases, the first among 14 documented cases to be described concerning mesenteric paragangliomas. One year follow up and CT scan revealed neither recurrence nor the presence of distant metastases.

[The immunomorphologic analysis of innervation of chromaffin paraganglian cells of the mammalian arteries and heart].

Innervation of chromaffin cells of paraganglia of the wall of mammalian large arterial vessels and heart (in rat, cat, and human) was studied by neuromorphological and immunohistochemical methods. There is established similarity in structure of specialized, "basket"-type nerve endings of the chromaffin cells (ChC) with pericellular nerve apparatuses of sympathetic and parasympathetic autonomic neurons. It is proposed to use immunohistochemical reaction for synaptophysin as method of selective detection of ChC of paraganglia and adrenal medulla. The conclusion is made that synaptophysin-positive terminals (SPPT) found on bodies of ChC and postganglionic neurons represent efferent, rather than afferent, synapses formed by myelinated axons of preganglionic fibers. It is suggested that ChC of paraganglia alongside with their characteristic endocrine function participate in complex mechanisms of chemoreceptor regulation of tissue homeostasis of mammalian blood vessels and heart.

[A rare cause of cardiogenic shock treated by extracorporeal life support: catecholamine secreting paraganglioma]. / Une cause rare de choc cardiogénique réfractaire nécessitant une assistance circulatoire : le paragangliome sécrétant.

Phaeochromocytoma and paraganglioma are chromaffine tumours secreting catecholamines. They are usually revealed by a paroxystic hypertensive crisis associated with headaches, palpitation and sweats. We reported a case of a young patient presenting a state of life threatening cardiogenic shock as unusual revelation of this tumour, requiring the implementation of an extracorporeal life support until myocardial recovery.

[High percentage of adrenergic symptoms in extraadrenal chromaffin tumors]. / Manifestaciones adrenérgicas de los tumores del tejido cromafín extraadrenal.

UNLABELLED: Descriptive retrospective study of 14 patients with paragangliomas (PGL) attended in the University Hospital of Vigo (Pontevedra) during the last 25 years to evaluating their characteristics and neuroendocrine potential. RESULTS: 71.4% were diagnosed due to mass tumoral effect, 21.4% due to adrenergic symptoms and 7.1% incidentally. Regarding to symptoms and signs 66.7% of PGL Simpatic (PGLS) and 40% of PGL Parasimpatic (PGLPS) presented adrenergic symptoms. Urine catecholamine analysis was carried out to 4 PGLS and high levels were found in all patients. The tumoral size reached a mean value of 37.8+/-18.9 mm, there were not differences found between both types of tumors. Inmunohistoquimia showed positive Chromogranine A stain in all patients. Two PGLS were maligns. Eleven patients had positive outcome, 2 PGLS died, and 1 PGLPS remains not cured. CONCLUSIONS: High percentage of patients had clinical manifestations related to catecholamine hyperproduction. We believe that due to the risk related to surgical treatment, malignance, multiple location and family associations, it would be advisable to carry out a complete examination prior to surgery.

Multiple minute nests of incidentally detected paraganglionic cells associated with urothelial carcinoma of the urinary bladder in a 73-year-old woman.

A 73-year-old woman who had undergone resection of urothelial carcinoma (UC) (G3 > G2) of the ureter was also found to have UC (G3) in the urinary bladder, spread throughout the urinary bladder with multiple foci of carcinoma in situ and small papillary cancers. Total cystectomy was therefore performed. On detailed microscopic examination of the extirpated urinary bladder, multiple minute cell nests, 14 in number and less than 2 mm in diameter each, consisting of cells harboring small nuclei and clear cytoplasm, were incidentally detected within the sub-mucosal layer and the proper muscle layer, mainly in the posterior wall of the urinary bladder. Some cell nests were clearly associated with ganglion cells. The cells in minute nests were positive on Grimelius staining and also strongly positive on staining with antibodies to chromogranin A, neuron-specific enolase (NSE), synaptophysin, and vimentin on immunohistochemical staining. In addition, sustentacular cells in the minute cell nests were positive for S100 protein. Staining with antibodies to pancytokeratin AE1/AE3, glial fibrillary acidic protein, and p53 was negative in the cell nests. Based on these findings, the multiple minute foci were diagnosed as paraganglionic cells (PGCs) incidentally detected in the urinary bladder of an elderly woman, in association with UC. Although PGCs are rarely detected in adult human urinary bladder on routine histopathological examination, the possibility of their existence should be kept in mind by pathologists, especially in coexistence with UC. This is the first case of PGCs associated with UC in the human urinary bladder in the English literature.

Zuckerkandl's organ improves long-term survival and function of neural stem cell derived dopaminergic neurons in Parkinsonian rats.

Transplantation of neural stem cells (NSC) derived dopamine (DA) neurons has emerged as an alternative approach to fetal neural cell transplantation in Parkinson's disease (PD). However, similar to fetal neural cell, survival of these neurons following transplantation is also limited due to limited striatal reinnervation (graft with dense neuronal core), limited host-graft interaction, poor axonal outgrowth, lack of continuous neurotrophic factors supply and principally an absence of cell adhesion molecules mediated appropriate developmental cues. In the present study, an attempt has been made to increase survival and function of NSC derived DA neurons, by co-grafting with Zuckerkandl's organ (a paraneural organ that expresses neurotrophic factors as well as cell adhesion molecules); to provide continuous NTF support and developmental cues to transplanted DA neurons in the rat model of PD. 24 weeks post transplantation, a significant number of surviving functional NSC derived DA neurons were observed in the co-transplanted group as evident by an increase in the number of tyrosine hydroxylase immunoreactive (TH-IR) neurons, TH-IR fiber density, TH-mRNA expression and TH-protein level at the transplantation site (striatum). Significant behavioral recovery (amphetamine induced stereotypy and locomotor activity) and neurochemical recovery (DA-D2 receptor binding and DA and DOPAC levels at the transplant site) were also observed in the NSC+ZKO co-transplanted group as compared to the NSC or ZKO alone transplanted group. In vivo results were further substantiated by in vitro studies, which suggest that ZKO increases the NSC derived DA neuronal survival, differentiation, DA release and neurite outgrowth as well as protects against 6-OHDA toxicity in co-culture condition. The present study suggests that long-term and continuous NTF support provided by ZKO to the transplanted NSC derived DA neurons, helped in their better survival, axonal arborization and integration with host cells, leading to long-term functional restoration in the rat model of PD.

Grafts of extra-adrenal chromaffin cells as aggregates show better survival rate and regenerative effects on parkinsonian rats than dispersed cell grafts.

The objective was to discern the neuroregenerative effect of grafts of extra-adrenal cells of the Zuckerkandl's paraganglion (ZP) in the nigrostriatal circuit, by using the retrograde model of parkinsonism in rats. The antiparkinsonian efficacy of two types of grafting procedures was studied (cell aggregates vs. dispersed cells), and GDNF and TGFbeta(1) (dopaminotrophic factors) as well as dopamine presence in extra-adrenal tissue was analyzed. Extra-adrenal chromaffin cells are noradrenergics, tissue dopamine is low, and they express both GDNF and TGFbeta(1). Grafts of cell aggregates, not of dispersed cells, exerted a trophic regeneration of the host striatum, leading to amelioration of motor deficits. Sprouting of spared dopaminergic fibers within the striatum, reduction of dopamine axon degeneration, and/or enhanced phenotypic expression of TH would explain striatal regeneration. Grafted cells as aggregates showed a better survival rate than dispersed cells, and they express higher levels of GDNF. Higher survivability and GDNF content together with the neurorestorative and dopaminotrophic action of both GDNF and TGFbeta(1) could account for striatal recovery and functional amelioration after grafting ZP cell aggregates. Finally, nigral degeneration and partial degeneration of ventral tegmental area were not precluded after transplantation, indicating that the trophic effect of grafts was local within the host striatum.

Peripheral chemoreceptors: postnatal development and cytochemical findings in Sudden Infant Death Syndrome.

The aim of the present study is to give a review of the postnatal development of peripheral chemoreceptors - carotid body, paraganglia, and pulmonary neuroendocrine cells (PNEC) - with implications in Sudden Infant Death Syndrome (SIDS). In the postnatal period, the hypoxic chemosensitivity of the carotid body gradually develops. Changes include proliferation of type I and II cells, increased numbers of dense core vesicles and K+ channels, and modifications of neurotransmitter/neuromodulator and receptor expression. Chromaffin paraganglia show increased expression of nitric oxide synthase and neuropeptides, and increased innervation. Innervation of PNEC develops fully only in the first postnatal period, after which their density falls. The neuropeptides produced by PNEC also changes, with increased expression of calcitonin gene-related peptide and neuropeptide YY and reduced expression of calcitonin and gastrin-releasing peptide. Most of the findings in the carotid body of SIDS victims, i.e., decrease in type I cells and dense cytoplasmic granules, and increase in progenitor cells, indicates immaturity of the carotid body, which may play a role in SIDS in the form of underlying biologic vulnerability. Aorticopulmonary paraganglia hyperplasia and increase of PNEC are also found in SIDS, and may be epiphenomena of alterations of the respiratory function with a pathogenetical role in SIDS. A comprehensive view of the pathogenesis of SIDS should also arise from the integration of peripheral chemoreceptors findings with neuro- and cardiopathologic ones.

Paraganglioma de glomus carotídeo derecho / Paraganglioma of glomus carotid right

Los Paragangliomas son tumores de cabeza y cuello poco frecuentes, histológicamente benignos, vascularizados, de crecimiento lento pudiendo ser cromafines o no. Se originan en los paraganglios extra adrenales de la cabeza neural, se presentan con mayor frecuencia en abdomen, su porcentaje de metástasis es bajo. Es más frecuente en el caso femenino, tiene una sobrevida libre de enfermedad de hasta 15 años. El diagnóstico se establece por clínica, tomografía, resonancia magnética y medicina nuclear, antiguamente se utilizaba la arteriografía carotídea. El tratamiento ideal es cirugía, sólo los casos avanzados, recidivantes o enfermedad metastásica deben recibir radioterapia. En este trabajo se describe la evolución clínico patológica de un caso de paraganglioma en cuerpo carotídeo derecho, el cual se maligniza sin cambios histológicos de importancia en corto período de evolución. Se plantea el tratamiento con Metaiodobenzilguanidina I-131 ya utilizada en otras lesiones similares con buena respuesta e influencia positiva en la sobrevida.

Circulating catecholamines and cardiorespiratory responses in hypoxic lungfish (Protopterus dolloi): a comparison of aquatic and aerial hypoxia.

Circulating catecholamine levels and a variety of cardiorespiratory variables were monitored in cannulated bimodally breathing African lungfish (Protopterus dolloi) exposed to aquatic or aerial hypoxia. Owing to the purported absence of external branchial chemoreceptors in lungfish and the minor role played by the gill in O2 uptake, it was hypothesized that plasma catecholamine levels would increase only during exposure of fish to aerial hypoxia. The rapid induction of aquatic hypoxia (final PWo2 = 25.9+/-1.6 mmHg) did not affect the levels of adrenaline (A) or noradrenaline (NA) within the plasma. Similarly, none of the measured cardiorespiratory variables--including heart rate (fH), blood pressure, air-breathing frequency (fV), O2 consumption (Mo2), CO2 excretion (Mco2), or blood gases--were influenced by acute aquatic hypoxia. In contrast, however, the rapid induction of aerial hypoxia (inspired Po2=46.6+/-3.3 mmHg) caused a marked increase in the circulating levels of A (from 7.9+/-2.0 to 18.8+/-6.1 nmol L(-1)) and NA (from 7.7+/-2.2 to 19.7+/-6.3 nmol L(-1)) that was accompanied by significant decreases in Mo2, arterial Po2 (Pao2), and arterial O2 concentration (Cao2). Air-breathing frequency was increased (by approximately five breaths per hour) during aerial hypoxia and presumably contributed to the observed doubling of pulmonary Mco2 (from 0.25+/-0.04 to 0.49+/-0.07 mmol kg(-1) h(-1)); fH and blood pressure were unaffected by aerial hypoxia. An in situ perfused heart preparation was used to test the possibility that catecholamine secretion from cardiac chromaffin cells was being activated by a direct localized effect of hypoxia. Catecholamine secretion from the chromaffin cells of the heart, while clearly responsive to a depolarizing concentration of KCl (60 mmol L(-1)), was unaffected by the O2 status of the perfusion fluid. The results of this study demonstrate that P. dolloi is able to mobilize stored catecholamines and increase f(V) during exposure to aerial hypoxia while remaining unresponsive to aquatic hypoxia. Thus, unlike in exclusively water-breathing teleosts, P. dolloi would appear to rely solely on internal/airway O2 chemoreceptors for initiating catecholamine secretion and cardiorespiratory responses.

Paraganglioma do órgão de Zuckerkandl: relato de caso / Paraganglioma Zuckerkandl's organ: case report

Os autores relatam o caso de uma mulher de 50 anos de idade que procurou auxílio médico referindo aumento do volume abdominal há 8 meses. Negava quaisquer outros sintomas. Tomografia computadorizada do abdome mostrou lesão sólida retroperitoneal medindo aproximadamente 6 por 5,2 cm na região inter-aórtico-caval. A biópsia percutânea da lesão revelou tratar-se de neoplasia indiferenciada compatível com feocromocitoma extra-adrenal. A paciente submeteu-se a laparotomia com resseção completa da lesão. O exame histopatológico do espécime cirúrgico foi compatível com paraganglioma. A paciente está bem e sem evidências de recidiva da doença 9 meses após a operação.