North Florida South Georgia Veterans Health System

Gainesville, FL, United States

North Florida South Georgia Veterans Health System

Gainesville, FL, United States

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David Weiner I.,Florida College | David Weiner I.,North Florida South Georgia Veterans Health System | Verlander J.W.,Florida College | Verlander J.W.,North Florida South Georgia Veterans Health System
Physiological Reviews | Year: 2017

Acid-base homeostasis is critical to maintenance of normal health. Renal ammonia excretion is the quantitatively predominant component of renal net acid excretion, both under basal conditions and in response to acid-base disturbances. Although titratable acid excretion also contributes to renal net acid excretion, the quantitative contribution of titratable acid excretion is less than that of ammonia under basal conditions and is only a minor component of the adaptive response to acid-base disturbances. In contrast to other urinary solutes, ammonia is produced in the kidney and then is selectively transported either into the urine or the renal vein. The proportion of ammonia that the kidney produces that is excreted in the urine varies dramatically in response to physiological stimuli, and only urinary ammonia excretion contributes to acid-base homeostasis. As a result, selective and regulated renal ammonia transport by renal epithelial cells is central to acid-base homeostasis. Both molecular forms of ammonia, NH3 and NH4 +, are transported by specific proteins, and regulation of these transport processes determines the eventual fate of the ammonia produced. In this review, we discuss these issues, and then discuss in detail the specific proteins involved in renal epithelial cell ammonia transport. © 2017 the American Physiological Society.


Elgendy I.Y.,University of Florida | Mahmoud A.N.,University of Florida | Elgendy A.Y.,University of Florida | Bavry A.A.,University of Florida | Bavry A.A.,North Florida South Georgia Veterans Health System
Circulation: Cardiovascular Interventions | Year: 2016

Background - In the era of drug-eluting stents, it is unknown if intravascular ultrasound (IVUS) guidance for percutaneous coronary intervention should be routinely endorsed. This study aimed to determine if IVUS-guided stent implantation is associated with improved outcomes. Methods and Results - Randomized trials that reported clinical outcomes and compared routine IVUS-guided stent implantation with an angiography-guided approach in the era of drug-eluting stents were included. Summary estimates were constructed primarily using the Peto model. Seven trials with 3192 patients were analyzed. The mean length of the coronary lesions was 32 mm. At a mean of 15 months, routine IVUS-guided percutaneous coronary intervention was associated with a reduction in the risk of major adverse cardiac events (6.5% versus 10.3%; odds ratio, 0.60; 95% confidence interval, 0.46-0.77; P<0.0001), mainly because of reduction in the risk of ischemia-driven target lesion revascularization (4.1% versus 6.6%; odds ratio, 0.60; 95% confidence interval, 0.43-0.84; P=0.003). The risk of cardiovascular mortality (0.5% versus 1.2%; odds ratio, 0.46; 95% confidence interval, 0.21-1.00; P=0.05), and stent thrombosis (0.6% versus 1.3%; odds ratio, 0.49; 95% confidence interval, 0.24-0.99; P=0.04) also appeared to be lower in the IVUS-guided group. Conclusions - In the era of drug-eluting stents for diffuse coronary lesions, IVUS-guided percutaneous coronary intervention is superior to angiography-guided percutaneous coronary intervention in reducing the risk of major adverse cardiac events. This is primarily because of reduction in the risk of ischemia-driven target lesion revascularization. This analysis also suggests that risk of cardiovascular mortality and stent thrombosis might be lower with an IVUS-guided approach. © 2016 American Heart Association, Inc.


Carnaby-Mann G.,University of Florida | Crary M.A.,University of Florida | Schmalfuss I.,North Florida South Georgia Veterans Health System | Amdur R.,University of Florida
International Journal of Radiation Oncology Biology Physics | Year: 2012

Purpose: Dysphagia after chemoradiotherapy is common. The present randomized clinical trial studied the effectiveness of preventative behavioral intervention for dysphagia compared with the "usual care." Methods and Materials: A total of 58 head-and-neck cancer patients treated with chemoradiotherapy were randomly assigned to usual care, sham swallowing intervention, or active swallowing exercises (pharyngocise). The intervention arms were treated daily during chemoradiotherapy. The primary outcome measure was muscle size and composition (determined by T 2-weighted magnetic resonance imaging). The secondary outcomes included functional swallowing ability, dietary intake, chemosensory function, salivation, nutritional status, and the occurrence of dysphagia-related complications. Results: The swallowing musculature (genioglossus, hyoglossuss, and mylohyoid) demonstrated less structural deterioration in the active treatment arm. The functional swallowing, mouth opening, chemosensory acuity, and salivation rate deteriorated less in the pharyngocise group. Conclusion: Patients completing a program of swallowing exercises during cancer treatment demonstrated superior muscle maintenance and functional swallowing ability. © 2012 Elsevier Inc. All rights reserved.


Weiner I.D.,North Florida South Georgia Veterans Health System | Weiner I.D.,Florida College | Mitch W.E.,Baylor College of Medicine | Sands J.M.,Emory University
Clinical Journal of the American Society of Nephrology | Year: 2015

Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. © 2015, by the American Society of Nephrology.


Weiner I.D.,North Florida South Georgia Veterans Health System | Weiner I.D.,Florida College
Seminars in Nephrology | Year: 2013

The identification of primary aldosteronism as a common cause of resistant hypertension is a significant advance in our ability to care for patients with hypertension. Primary aldosteronism is common, and when unrecognized is associated with an increased incidence of adverse cardiovascular outcomes. Identification of primary aldosteronism is based on use of the plasma aldosterone level, plasma renin activity, and the aldosterone:renin ratio. Differentiation between unilateral and bilateral autonomous adrenal aldosterone production then guides further therapy, with use of mineralocorticoid-receptor blockers for patients with bilateral autonomous adrenal aldosterone production and laparoscopic adrenalectomy for patients with unilateral autonomous aldosterone production. In this review, we discuss in detail the pathogenesis of primary aldosteronism-induced hypertension and potassium disorders, the evaluation of the patient with suspected primary aldosteronism, and the management of primary aldosteronism, both through medications and surgery. © 2013.


Wang G.P.,Florida College | Wang G.P.,North Florida South Georgia Veterans Health System
Genome Medicine | Year: 2015

Periodontitis is a common inflammatory disease that leads to tooth loss and has been linked to cardiovascular disease and diabetes mellitus. The periodontal microbiome is highly diverse, and metatranscriptomic studies have indicated that the genes that are expressed by the microbiota are more relevant than the microbial composition in the pathogenesis of periodontitis. A recent study of early metabolic activities in the dysbiotic microbiome reveals a functional signature that distinguishes periodontal sites that will become inflamed, supporting the idea that microbial communities as a whole drive disease progression. © Wang licensee BioMed Central.


Weiner I.D.,North Florida South Georgia Veterans Health System | Weiner I.D.,Florida College | Verlander J.W.,North Florida South Georgia Veterans Health System
American Journal of Physiology - Renal Physiology | Year: 2014

Renal ammonia metabolism is a fundamental element of acid-base homeostasis, comprising a major component of both basal and physiologically altered renal net acid excretion. Over the past several years, a fundamental change in our understanding of the mechanisms of renal epithelial cell ammonia transport has occurred, replacing the previous model which was based upon diffusion equilibrium for NH3 and trapping of NH4 + with a new model in which specific and regulated transport of both NH3 and NH4 + across renal epithelial cell membranes via specific membrane proteins is required for normal ammonia metabolism. A major advance has been the recognition that members of a recently recognized transporter family, the Rhesus glycoprotein family, mediate critical roles in renal and extrarenal ammonia transport. The erythroid-specific Rhesus glycoprotein, Rh A Glycoprotein (Rhag), was the first Rhesus glycoprotein recognized as an ammonia-specific transporter. Subsequently, the nonerythroid Rh glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), were cloned and identified as ammonia transporters. They are expressed in specific cell populations and membrane domains in distal renal epithelial cells, where they facilitate ammonia secretion. In this review, we discuss the distribution of Rhbg and Rhcg in the kidney, the regulation of their expression and activity in physiological disturbances, the effects of genetic deletion on renal ammonia metabolism, and the molecular mechanisms of Rh glycoprotein-mediated ammonia transport. © 2014 the American Physiological Society.


Sisco S.M.,North Florida South Georgia Veterans Health System
Journal of aging and health | Year: 2013

This article investigated how a multicomponent memory intervention affected memory for prose. We compared verbatim and paraphrased recall for short stories immediately and 1, 2, 3, and 5 years post-intervention in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) sample. We studied 1,912 ACTIVE participants aged 65 to 91. Participants were randomized into one of three training arms (Memory, Reasoning, Speed of Processing) or a no-contact Control group; about half of the trained participants received additional booster training 1 and 3 years post-intervention. Memory-trained participants showed higher verbatim recall than non-memory-trained participants. Booster-memory training led to higher verbatim recall. Memory training effects were evident immediately following training and not after 1 year following training. Results suggest that multifactorial memory training can improve verbatim recall for prose, but the effect does not last without continued intervention.


Fernandez E.M.,North Florida South Georgia Veterans Health System | Franck A.J.,North Florida South Georgia Veterans Health System
Annals of Pharmacotherapy | Year: 2011

OBJECTIVE: To evaluate current evidence for the use of lacosamide in the treatment of refractory status epilepticus. DATA SOURCES: Literature was accessed via PubMed (through July 2011) using the terms lacosamide and status epilepticus. STUDY SELECTION AND DATA EXTRACTION: All reports on the use of lacosamide in patients with status epilepticus were included for evaluation. Reviews and animal data were excluded. DATA SYNTHESIS: Treatment of status epilepticus is challenging, and most patients fail to respond to initial treatment. Recently, several reports have been published on the use of lacosamide for status epilepticus. Eleven reports (5 case reports and 6 case series) were identified. Lacosamide was credited with successful termination of status epilepticus in a majority of these reports. However, the data are weakened by the heterogeneity of the reports, their descriptive nature, and the common divergence from current recommendations for the treatment of status epilepticus. CONCLUSIONS: While lacosamide has been reported as an effective treatment for refractory status epilepticus, there is insufficient evidence for its routine use. For cases in which the risks associated with anesthetizing drugs are believed to outweigh the benefits, such as in complex partial status epilepticus, lacosamide may be a reasonable option after more established drug therapies fail.


Franck A.J.,North Florida South Georgia Veterans Health System
Journal of Parenteral and Enteral Nutrition | Year: 2014

Parenteral nutrition product shortages are common and place vulnerable patients at risk for nutrient deficiencies. This case report describes a parenteral nutrition-dependent patient who was found to have zinc deficiency during a parenteral nutrition product shortage. The management of the patient's zinc deficiency is described. © 2014 American Society for Parenteral and Enteral Nutrition.

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