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Joseph G Verbalis - One of the best experts on this subject based on the ideXlab platform.
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Disorders of Water and Salt Metabolism Endocrinol Metab Clin N AmAssociated
2015Co-Authors: Pituitary Disease, Jennifer A. Loh, Joseph G VerbalisAbstract:Disorders of Water and sodium homeostasis are very common problems en-countered in clinical medicine. Disorders of Water Metabolism are divided into hyperosmolar and hypoosmolar states, with hyperosmolar disorders charac-terized by a deficit of body Water in relation to body solute, and hypoosmolar disorders characterized by an excess of body Water in relation to total body solute. Because sodium is the main constituent of plasma osmolality, these disorders are typically characterized by hypernatremia and hyponatremia, respectively. Hyponatremia is far more common, occurring at prevalences as high as 6 % to 22 % of hospitalized patients [1], and has been associated withmortality rates from 0 % to 50%, depending on the acuteness and severity of the hyponatremia. Hypernatremia has a prevalence of only 1 % of hospital-ized patients, but is associated with highmortality rates, from 42 % to 60 % [2]. In the setting of intrasellar and suprasellar lesions, excessive Water loss from diabetes insipidus is more likely than inappropriate Water retention from the syndrome of inappropriate antidiuretic hormone secretion (SIADH), although both can occur following surgical resection of these lesions. This article briefly reviews the physiology of hyperosmolar and hy-poosmolar syndromes, then focuses on a discussion of the pathophysiology, evaluation, and treatment of specific pre- and postoperative disorders of Water Metabolism in patients with pituitary lesions. Overview of normal Water Metabolism Water Metabolism is controlled primarily by arginine vasopressin (AVP),37 (2008) 213–234a nonapeptide that is synthesized in the neurohypophyseal magnocellular * Corresponding author
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managing hyponatremia in patients with syndrome of inappropriate antidiuretic hormone secretion
Endocrinología y Nutrición, 2010Co-Authors: Joseph G VerbalisAbstract:Disorders of sodium [Na+] and Water Metabolism are commonly encountered in the hospital setting due to the wide range of disease states that can disrupt the balanced control of Water and solute intake and output. In particular, the prompt identification and appropriate management of abnormally low serum [Na+] is critical if we are to reduce the increased morbidity and mortality that accompany hyponatremia in hospitalized patients. Use of an algorithm that is based primarily on the symptomatology of hyponatremic patients, rather than the serum [Na+] or the chronicity of the hyponatremia, will help to choose the correct initial therapy in hospitalized hyponatremic patients. However, careful monitoring of serum [Na+] responses is required in all cases to adjust therapy appropriately in response to changing clinical conditions. Although this approach will enable efficacious and safe treatment of hyponatremic patients with syndrome of inappropriate antidiuretic hormone secretion (SIADH) at the present time, evolving knowledge of the consequences of chronic hyponatremia will likely alter treatment indications and guidelines in the future.
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disorders of Water and salt Metabolism associated with pituitary disease
Endocrinology and Metabolism Clinics of North America, 2008Co-Authors: Joseph G VerbalisAbstract:Disorders of Water and sodium homeostasis are very common problems encountered in clinical medicine. Disorders of Water Metabolism are divided into hyperosmolar and hypoosmolar states, with hyperosmolar disorders characterized by a deficit of body Water in relation to body solute and hypoosmolar disorders characterized by an excess of body Water in relation to total body solute. This article briefly reviews the physiology of hyperosmolar and hypoosmolar syndromes, then focuses on a discussion of the pathophysiology, evaluation, and treatment of specific pre- and postoperative disorders of Water Metabolism in patients with pituitary lesions.
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management of disorders of Water Metabolism in patients with pituitary tumors
Pituitary, 2002Co-Authors: Joseph G VerbalisAbstract:Disorders of body fluids, notably central diabetes insipidus (CDI) and the syndrome of inappropriate antidiuretic hormone secretion (SIADH), are relatively uncommon as a presenting symptom of sellar and suprasellar masses, but quite common following surgical resection of such lesions. It therefore behooves clinicians treating such patients to have a good understanding of the pathophysiology, the differential diagnosis and the management of these disorders. This review discusses some general issues concerning the pathogenesis, differential diagnosis, clinical manifestations and therapy of hyperosmolar and hypoosmolar syndromes, including CDI and SIADH, and then more specifically addresses the evaluation and treatment of pre- and postoperative disorders of Water Metabolism in patients with pituitary adenomas.
M A Renouf - One of the best experts on this subject based on the ideXlab platform.
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understanding urban Water performance at the city region scale using an urban Water Metabolism evaluation framework
Water Research, 2018Co-Authors: M A Renouf, Steven Kenway, Ka Leung Lam, Tony Weber, Estelle Roux, Silvia Serraoneumann, Darryl Low Choy, Edward A MorganAbstract:Water sensitive interventions are being promoted to reduce the adverse impacts of urban development on natural Water cycles. However it is currently difficult to know the best strategy for their implementation because current and desired urban Water performance is not well quantified. This is particularly at the city-region scale, which is important for strategic urban planning. This work aimed to fill this gap by quantifying the Water performance of urban systems within city-regions using 'urban Water Metabolism' evaluation, to inform decisions about Water sensitive interventions. To do this we adapted an existing evaluation framework with new methods. In particular, we used land use data for defining system boundaries, and for estimating natural hydrological flows. The criteria for gauging the Water performance were Water efficiency (in terms of Water extracted externally) and hydrological performance (how much natural hydrological flows have changed relative to a nominated pre-urbanised state). We compared these performance criteria for urban systems within three Australian city-regions (South East Queensland, Melbourne and Perth metropolitan areas), under current conditions, and after implementation of example Water sensitive interventions (demand management, rainWater/stormWater harvesting, wasteWater recycling and increasing perviousness). The respective Water efficiencies were found to be 79, 90 and 133 kL/capita/yr. In relation to hydrological performance, stormWater runoff relative to pre-urbanised flows was of most note, estimated to be 2-, 6- and 3- fold, respectively. The estimated performance benefits from Water sensitive interventions suggested different priorities for each region, and that combined implementation of a range of interventions may be necessary to make substantive gains in performance. We concluded that the framework is suited to initial screening of the type and scale of Water sensitive interventions needed to achieve desired Water performance objectives.
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urban Water Metabolism indicators derived from a Water mass balance bridging the gap between visions and performance assessment of urban Water resource management
Water Research, 2017Co-Authors: M A Renouf, Steven Kenway, Silvia Serraoneumann, Edward A Morgan, Low D ChoyAbstract:Improving resource management in urban areas has been enshrined in visions for achieving sustainable urban areas, but to date it has been difficult to quantify performance indicators to help identify more sustainable outcomes, especially for Water resources. In this work, we advance quantitative indicators for what we refer to as the ‘metabolic’ features of urban Water management: those related to resource efficiency (for Water and also Water-related energy and nutrients), supply internalisation, urban hydrological performance, sustainable extraction, and recognition of the diverse functions of Water. We derived indicators in consultation with stakeholders to bridge this gap between visions and performance indicators. This was done by first reviewing and categorising Water-related resource management objectives for city-regions, and then deriving indicators that can gauge performance against them. The ability for these indicators to be quantified using data from an urban Water mass balance was also examined. Indicators of Water efficiency, supply internalisation, and hydrological performance (relative to a reference case) can be generated using existing urban Water mass balance methods. In the future, indicators for Water-related energy and nutrient efficiencies could be generated by overlaying the urban Water balance with energy and nutrient data. Indicators of sustainable extraction and recognising diverse functions of Water will require methods for defining sustainable extraction rates and a Water functionality index.
Roberto Salvatori - One of the best experts on this subject based on the ideXlab platform.
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posterior pituitary abnormalities caused by pituitary tumors
Current Opinion in Endocrine and Metabolic Research, 2018Co-Authors: Roberto SalvatoriAbstract:Abstract The posterior pituitary gland tightly controls Water balance. Before surgery, pituitary adenomas-no matter how large-almost never cause diabetes insipidus, and very rarely cause the syndrome of inappropriate ADH secretion (SIADH). Conversely, disorders of Water Metabolism are a relatively common complication of surgery for pituitary adenomas. These abnormalities are most often transient, but require careful monitoring and expert management in order to avoid potentially dangerous abrupt variations of blood sodium levels. In this article we will review such abnormalities, and the best way to diagnose and treat them promptly.
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current best practice in the management of patients after pituitary surgery
Therapeutic Advances in Endocrinology and Metabolism, 2017Co-Authors: Alessandro Prete, Salvatore Maria Corsello, Roberto SalvatoriAbstract:Sellar and parasellar masses are a common finding, and most of them are treated surgically via transsphenoidal approach. This type of surgery has revolutionized the approach to several hypothalamic-pituitary diseases and is usually effective, and well-tolerated by the patient. However, given the complex anatomy and high density of glandular, neurological and vascular structures in a confined space, transsphenoidal surgery harbors a substantial risk of complications. Hypopituitarism is one of the most frequent sequelae, with central adrenal insufficiency being the deficit that requires a timely diagnosis and treatment. The perioperative management of AI is influenced by the preoperative status of the hypothalamic-pituitary-adrenal axis. Disorders of Water Metabolism are another common complication, and they can span from diabetes insipidus, to the syndrome of inappropriate antidiuretic hormone secretion, up to the rare cerebral salt-wasting syndrome. These abnormalities are often transient, but require careful monitoring and management in order to avoid abrupt variations of blood sodium levels. Cerebrospinal fluid leaks, damage to neurological structures such as the optic chiasm, and vascular complications can worsen the postoperative course after transsphenoidal surgery as well. Finally, long-term follow up after surgery varies depending on the underlying pathology, and is most challenging in patients with acromegaly and Cushing disease, in whom failure of primary pituitary surgery is a major concern. When these pituitary functioning adenomas persist or relapse after neurosurgery other treatment options are considered, including repeated surgery, radiotherapy, and medical therapy.
Edward A Morgan - One of the best experts on this subject based on the ideXlab platform.
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understanding urban Water performance at the city region scale using an urban Water Metabolism evaluation framework
Water Research, 2018Co-Authors: M A Renouf, Steven Kenway, Ka Leung Lam, Tony Weber, Estelle Roux, Silvia Serraoneumann, Darryl Low Choy, Edward A MorganAbstract:Water sensitive interventions are being promoted to reduce the adverse impacts of urban development on natural Water cycles. However it is currently difficult to know the best strategy for their implementation because current and desired urban Water performance is not well quantified. This is particularly at the city-region scale, which is important for strategic urban planning. This work aimed to fill this gap by quantifying the Water performance of urban systems within city-regions using 'urban Water Metabolism' evaluation, to inform decisions about Water sensitive interventions. To do this we adapted an existing evaluation framework with new methods. In particular, we used land use data for defining system boundaries, and for estimating natural hydrological flows. The criteria for gauging the Water performance were Water efficiency (in terms of Water extracted externally) and hydrological performance (how much natural hydrological flows have changed relative to a nominated pre-urbanised state). We compared these performance criteria for urban systems within three Australian city-regions (South East Queensland, Melbourne and Perth metropolitan areas), under current conditions, and after implementation of example Water sensitive interventions (demand management, rainWater/stormWater harvesting, wasteWater recycling and increasing perviousness). The respective Water efficiencies were found to be 79, 90 and 133 kL/capita/yr. In relation to hydrological performance, stormWater runoff relative to pre-urbanised flows was of most note, estimated to be 2-, 6- and 3- fold, respectively. The estimated performance benefits from Water sensitive interventions suggested different priorities for each region, and that combined implementation of a range of interventions may be necessary to make substantive gains in performance. We concluded that the framework is suited to initial screening of the type and scale of Water sensitive interventions needed to achieve desired Water performance objectives.
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urban Water Metabolism indicators derived from a Water mass balance bridging the gap between visions and performance assessment of urban Water resource management
Water Research, 2017Co-Authors: M A Renouf, Steven Kenway, Silvia Serraoneumann, Edward A Morgan, Low D ChoyAbstract:Improving resource management in urban areas has been enshrined in visions for achieving sustainable urban areas, but to date it has been difficult to quantify performance indicators to help identify more sustainable outcomes, especially for Water resources. In this work, we advance quantitative indicators for what we refer to as the ‘metabolic’ features of urban Water management: those related to resource efficiency (for Water and also Water-related energy and nutrients), supply internalisation, urban hydrological performance, sustainable extraction, and recognition of the diverse functions of Water. We derived indicators in consultation with stakeholders to bridge this gap between visions and performance indicators. This was done by first reviewing and categorising Water-related resource management objectives for city-regions, and then deriving indicators that can gauge performance against them. The ability for these indicators to be quantified using data from an urban Water mass balance was also examined. Indicators of Water efficiency, supply internalisation, and hydrological performance (relative to a reference case) can be generated using existing urban Water mass balance methods. In the future, indicators for Water-related energy and nutrient efficiencies could be generated by overlaying the urban Water balance with energy and nutrient data. Indicators of sustainable extraction and recognising diverse functions of Water will require methods for defining sustainable extraction rates and a Water functionality index.
Wladimiro Jiménez - One of the best experts on this subject based on the ideXlab platform.
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effect of the v1a v2 avp receptor antagonist conivaptan on renal Water Metabolism and systemic hemodynamics in rats with cirrhosis and ascites
Journal of Hepatology, 2003Co-Authors: Guillermo Fernandezvaro, Josefa Ros, Carmen Cano, Vicente Arroyo, Francisca Rivera, Juan Rodés, Pilar Cejudomartin, Wladimiro JiménezAbstract:Abstract Background : Selective V 2 -AVP receptor antagonists are effective in inducing aquaresis in humans and rats with cirrhosis, hyponatremia and Water retention. However, it is unknown whether dual V 1a /V 2 -AVP antagonists are also efficacious as aquaretic agents under these conditions. This is important, particularly considering that blockade of V 1a -AVP receptors could aggravate cardiocirculatory function in decompensated cirrhosis. Aims : To evaluate the renal, hormonal and hemodynamic effects induced by the chronic oral administration of the V 1a /V 2 -AVP antagonist, Conivaptan, in rats with CCl 4 -induced cirrhosis, ascites and severe Water retention. Methods : We assessed the aquaretic efficacy of 10-day chronic oral administration of Conivaptan (0.5mg/kg body weight (bw)) in cirrhotic rats with hyponatremia and Water retention. Urine volume (UV), osmolality (UOsm), and sodium excretion (U Na V) were measured daily. At the end of the study arterial pressure was also measured. Results : Conivaptan produced an acute increase in UV, a reduction in UOsm and, at the end of the investigation, cirrhotic rats receiving the V 1a /V 2 -AVP receptor antagonist did not show hyponatremia or hypoosmolality. Conivaptan also normalized U Na V without affecting creatinine clearance and arterial pressure. Conclusions : Dual V 1a /V 2 -receptor antagonists may be therapeutically useful for the treatment of Water retention and dilutional hyponatremia in human cirrhosis.
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selective inhibition of cyclooxygenase 2 spares renal function and prostaglandin synthesis in cirrhotic rats with ascites
Gastroenterology, 1999Co-Authors: Marta Bosch Marce, Vicente Arroyo, Francisca Rivera, Wladimiro Jiménez, Joan Claria, Esther Titos, Jaime L Masferrer, Rosario Altuna, J L Poo, Joan RodesAbstract:Abstract Background & Aims: The critical role of cyclooxygenase (COX) products in maintenance of renal function in cirrhosis with ascites discourages the use of nonsteroidal anti-inflammatory drugs in this disease. The recent development of selective COX-2 inhibitors opens new avenues for the use of these compounds in decompensated cirrhosis. The current study evaluates the effects of a selective COX-2 inhibitor (SC-236) on renal function in cirrhotic rats with ascites. Methods: In protocol 1, urine volume, urinary excretion of sodium and prostaglandins, glomerular filtration rate, and renal plasma flow were measured before and after administration of SC-236 (n = 12) or ketorolac (n = 10) to rats with cirrhosis. Protocol 2 was aimed at assessing the effects of COX inhibitors on renal Water Metabolism in 28 cirrhotic rats. Results: Administration of SC-236 to cirrhotic animals did not produce significant renal effects, whereas administration of the nonselective COX-1/COX-2 inhibitor, ketorolac, resulted in a marked reduction in urine volume, urinary excretion of prostaglandins, and glomerular filtration rate and in a significant impairment in renal Water Metabolism. Conclusions: These findings indicate that SC-236 does not significantly impair renal function in rats with cirrhosis. GASTROENTEROLOGY 1999;116:1167-1175
