Publications by authors named "Dorin R"

Hyperglycemic emergencies cause significant losses of body water, sodium, and potassium. This report presents a method for computing the actual losses of water and monovalent cations in these emergencies. We developed formulas for computing the losses of water and monovalent cations as a function of the presenting serum sodium and glucose levels, the sum of the concentrations of sodium plus potassium in the lost fluids, and body water at the time of hyperglycemia presentation as measured by bioimpedance or in the initial euglycemic state as estimated by anthropometric formulas.

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Preoperative management of a pheochromocytoma involves α-adrenergic receptor blockers and volume expansion followed by β-adrenergic receptor blockers and then adrenalectomy, which in the presence of very severe aortic valve stenosis would be challenging. We describe a patient with this rare combination who underwent pharmacotherapy followed by transcatheter aortic valve replacement and then adrenalectomy, culminating in a successful outcome for this patient.

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In hyperglycemia, the serum sodium concentration () receives influences from (a) the fluid exit from the intracellular compartment and thirst, which cause decreases; (b) osmotic diuresis with sums of the urinary sodium plus potassium concentration lower than the baseline euglycemic , which results in a increase; and (c), in some cases, gains or losses of fluid, sodium, and potassium through the gastrointestinal tract, the respiratory tract, and the skin. Hyperglycemic patients with hypernatremia have large deficits of body water and usually hypovolemia and develop severe clinical manifestations and significant mortality. To assist with the correction of both the severe dehydration and the hypovolemia, we developed formulas computing the fractional losses of the body water and monovalent cations in hyperglycemia.

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Membrane fouling by monoclonal antibodies (mAbs) is one of the main challenges in virus-filtration processes. Previous publications attributed membrane fouling to the presence of mAb aggregates in the solution, which block the membrane pores. This fouling mechanism can be solved by a prefilter; however, it was shown that there are mAbs that severely foul the membranes (reduce permeability by 90% and more) even after prefiltering the aggregates, while other mAbs foul the membrane weakly (reduce permeability by ~10% and less).

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Context: Estimated rates of cortisol elimination and appearance vary according to the model used to obtain them. Generalizability of current models of cortisol disposition in healthy humans is limited.

Objective: Development and validation of a realistic, mechanistic model of cortisol disposition that accounts for the major factors influencing plasma cortisol concentrations (Model 4), and comparison to previously described models of cortisol disposition in current clinical use (Models 1-3).

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Background & Aims: Hepatic enzymes play a major role in the metabolic elimination of cortisol, and reduced rates of cortisol clearance have been consistently observed in patients with chronic liver disease. It is less clear whether there are concomitant abnormalities of adrenocortical function in patients with cirrhosis. In the present study, we sought to assess adrenocortical function in patients with cirrhosis using measures of free cortisol appearance and elimination rates that are independent of serum concentrations of cortisol binding proteins.

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Objective: To demonstrate the noninferiority of the fundamentals of robotic surgery (FRS) skills curriculum over current training paradigms and identify an ideal training platform.

Summary Background Data: There is currently no validated, uniformly accepted curriculum for training in robotic surgery skills.

Methods: Single-blinded parallel-group randomized trial at 12 international American College of Surgeons (ACS) Accredited Education Institutes (AEI).

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Fundamentals of robotic surgery (FRS) is a proficiency-based progression curriculum developed by robotic surgery experts from multiple specialty areas to address gaps in existing robotic surgery training curricula. The RobotiX Mentor is a virtual reality training platform for robotic surgery. Our aims were to determine if robotic surgery novices would demonstrate improved technical skills after completing FRS training on the RobotiX Mentor, and to compare the effectiveness of FRS across training platforms.

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Purpose: Dialysis-associated hyperglycemia (DAH), is associated with a distinct fluid and electrolyte pathophysiology. The purpose of this report was to review the pathophysiology and provide treatment guidelines for DAH.

Methods: Review of published reports on DAH.

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Purpose: To evaluate the influence of single nucleotide polymorphisms (SNPs) of CYP19A1 on the response and susceptibility to side effects from testosterone therapy. This is a prospective, single-arm study of men with low-morning serum testosterone (<10.68 nmol/l) administered testosterone cypionate 200 mg intramuscularly every 2 weeks for 18 months.

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Context: In secondary adrenal insufficiency (SAI), chronic deficiency of adrenocorticotropin (ACTH) is believed to result in secondary changes in adrenocortical function, causing an altered dose-response relationship between ACTH concentration and cortisol secretion rate (CSR).

Objective: We sought to characterize maximal cortisol secretion rate (CSR) and free cortisol half-life in patients with SAI, compare results with those of age-matched healthy controls, and examine the influence of predictor variables on ACTH-stimulated cortisol concentrations.

Design: CSR was estimated from ACTH (250 μg)stimulated cortisol time-concentration data.

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Although hypogonadism is a risk factor for bone loss and fractures, the different etiopathophysiology and hormonal profile of classical and obesity-induced hypogonadism may lead to differences in musculoskeletal profile. This is a cross-sectional study of hypogonadal men between 40 and 74 years old. Our outcomes include: areal bone mineral density (aBMD) and body composition by dual-energy X-ray absorptiometry; volumetric BMD (vBMD) and soft tissue composition of the tibia by peripheral quantitative computed tomography.

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The functionalization with phosphotriesterase of poly(isoprene-b-styrene-b-4-vinylpyridine)-based nanoporous membranes fabricated by self-assembly and nonsolvent induced phase separation (SNIPS) is shown to enable dynamically responsive membranes capable of substrate-specific and localized gating response. Integration of the SNIPS process with macroporous nylon support layers yields mechanically robust textile-type films with high moisture vapor transport rates that display rapid and local order-of-magnitude modulation of permeability. The simplicity of the fabrication process that is compatible with large-area fabrication along with the versatility and efficacy of enzyme reactivity offers intriguing opportunities for engineered biomimetic materials that are tailored to respond to a complex range of external parameters, providing sensing, protection, and remediation capabilities.

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Introduction: Both hypogonadism and type 2 diabetes mellitus (T2D) are associated with increased fracture risk. Emerging data support the negative effect of low testosterone on glucose metabolism, however, there is little information on the bone health of hypogonadal men with diabetes. We evaluated the bone mineral density (BMD), bone geometry and bone turnover of hypogonadal men with T2D compared to hypogonadal men without diabetes.

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Respiratory failure complicating the course of diabetic ketoacidosis (DKA) is a source of increased morbidity and mortality. Detection of respiratory failure in DKA requires focused clinical monitoring, careful interpretation of arterial blood gases, and investigation for conditions that can affect adversely the respiration. Conditions that compromise respiratory function caused by DKA can be detected at presentation but are usually more prevalent during treatment.

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Objective: To characterize changes in indices of urinary function in prostatectomy patients with presurgical voiding symptoms.

Methods: A retrospective analysis of our prostate cancer database identified robot-assisted radical prostatectomy patients between April 2007 and December 2011 who completed pre- and postsurgical (24 months) Expanded Prostate Cancer Index Composite-26 surveys. Gleason score, margins, D'Amico risk, prostate-specific antigen, radiotherapy, and nerve-sparing status were tabulated.

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Purpose: To define the time needed by urology residents to attain proficiency in computer-aided robotic surgery to aid in the refinement of a robotic surgery simulation curriculum.

Methods: We undertook a retrospective review of robotic skills training data acquired during January 2012 to December 2014 from junior (postgraduate year [PGY] 2-3) and senior (PGY4-5) urology residents using the da Vinci Skills Simulator. We determined the number of training sessions attended and the level of proficiency achieved by junior and senior residents in attempting 11 basic or 6 advanced tasks, respectively.

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Background: Adrenal dysfunction is frequently reported in severe acute hepatitis using serum total cortisol.

Aims: Because 90% of serum cortisol is bound to proteins that are altered during stress, we investigated the effect of decreased cortisol-binding proteins on serum total and free cortisol in severe acute hepatitis.

Methods: 43 severe and 31 non-severe acute hepatitis and 29 healthy controls were enrolled consecutively and studied prospectively.

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A man with past lithium use for more than 15 years, but off lithium for two years and not carrying the diagnosis of diabetes mellitus or nephrogenic diabetes insipidus (NDI), presented with coma and hyperglycemic hyperosmolar state (HHS). Following correction of HHS, he developed persistent hypernatremia accompanied by large volumes of urine with low osmolality and no response to desmopressin injections. Urine osmolality remained < 300 mOsm/kg after injection of vasopressin.

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Graded porous inorganic materials directed by macromolecular self-assembly are expected to offer unique structural platforms relative to conventional porous inorganic materials. Their preparation to date remains a challenge, however, based on the sparsity of viable synthetic self-assembly pathways to control structural asymmetry. Here we demonstrate the fabrication of graded porous carbon, metal, and metal oxide film structures from self-assembled block copolymer templates by using various backfilling techniques in combination with thermal treatments for template removal and chemical transformations.

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Introduction: Urologic malignancies are often diagnosed at an older age, and are increasingly managed utilizing robotic-assisted surgical techniques. As such, we assessed and compared peri-postoperative complication rates following robotic urologic surgery in elderly and younger patients.

Materials And Methods: A retrospective analysis of IRB-approved databases and electronic medical records identified patients who underwent robotic-assisted urologic surgery between December 2003-September 2013.

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Background: While the treatment pathway in response to benign or malignant prostate biopsies is well established, there is uncertainty regarding the risk of subsequently diagnosing prostate cancer when an initial diagnosis of prostate atypia is made. As such, we investigated the likelihood of a repeat biopsy diagnosing prostate cancer (PCa) in patients in which an initial biopsy diagnosed prostate atypia.

Methods: We reviewed our prospectively maintained prostate biopsy database to identify patients who underwent a repeat prostate biopsy within one year of atypia (atypical small acinar proliferation; ASAP) diagnosis between November 1987 and March 2011.

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