Hypertensive Crisis in a Pediatric Patient Experiencing Clonidine Withdrawal.

Background: Clonidine, a central alpha-adrenoreceptor agonist, was initially developed as an antihypertensive. Though no longer commonly used for its original indication due to rebound hypertension after discontinuation, it is currently widely prescribed as a treatment for many pediatric indications including sleep disorders, behavioral concerns, and attention deficit hyperactivity disorder. Case Report. We describe a girl who developed prolonged symptoms of clonidine withdrawal, including hypertension and elevated serum metanephrines. Discussion. Clonidine withdrawal in pediatric patient can present with hypertensive urgency and other signs of sympathetic stimulation. Withdrawal can also lead to dramatic elevation in serum metanephrines. Treatment with a clonidine taper will reduce development of withdrawal symptoms. Conclusion: Given the rise in clonidine use in pediatric patients, clinicians should be aware of the risk of clonidine withdrawal and how to recognize and avoid its development.

U.S. Refugee Resettlement Is in Ruins-It Is Our Duty to Rebuild It.

Beginning in 2017, policy changes impacting the U.S. Refugee Admissions Program (USRAP) led to dramatic cuts in U.S. refugee resettlement. These changes have impeded relief of humanitarian crises, compromising the safety of tens of thousands of refugees eligible for resettlement and delaying family reunification. Rebuilding USRAP will require significant funding, support, and time. Such rebuilding is a necessary step in addressing the global refugee crisis and a potential life-saving intervention for many refugees, who suffer a range of threats and maladies. Many have chronic untreated medical issues and untold psychological trauma-physical and emotional wounds from years of persecution. They need-and deserve-our help.

Escherichia Coli bacteremia and rapidly progressive cellulitis in a child with newly diagnosed nephrotic syndrome.

Nephrotic syndrome (NS) in children is associated with spontaneous bacterial infections, including peritonitis as well as cellulitis secondary to chronic third-spacing of intracellular fluid. Typical pathogens that cause cellulitis in these patients are gram-positive bacteria whereas gram-negative organisms are uncommon. We report a case of Escherichia coli bacteremia with associated rapidly progressive cellulitis in an 11-year-old child with newly diagnosed NS, who had only recently started steroid therapy. Our case highlights the multifactorial effects of NS on the immune system that result in a predisposition towards infection. It also underscores the importance of a broad approach to neuro-atypical children with common clinical complaints.

Bacteremia in a Newborn with Hypocalcemic Seizures and Vitamin D Deficiency.

Infants with neonatal hypocalcemia often present with seizures, and neonatal hypocalcemia can be due to parathyroid (PTH) insufficiency or resistance. Causes of hypocalcemia with PTH elevation include increased phosphate load, vitamin D deficiency (VDD) or defects in metabolism, renal dysfunction, hypomagnesemia, genetic mutations resulting in end-organ resistance to PTH, or critical illness. Hypocalcemia has also been shown to be associated with Gram-negative bacteremia and sepsis in adults. We present the case of a full-term, formula-fed newborn presenting with late-onset hypocalcemic seizures and VDD in the setting of Klebsiella pneumoniae bacteremia. This case highlights that newborns presenting with hypocalcemic seizures should undergo a workup for sepsis.

First reported case of vertebral osteomyelitis due to Erysipelothrix rhusiopathiae.

We describe a case of acute vertebral osteomyelitis with associated prevertebral abscess due to Erysipelothrix rhusiopathiae in an immunocompetent adult with recent known traumatic inoculation from the barb of a fish.

Metabolome response to glucose in the ß-cell line INS-1 832/13.

Glucose-stimulated insulin secretion (GSIS) from pancreatic ß-cells is triggered by metabolism of the sugar to increase ATP/ADP ratio that blocks the KATP channel leading to membrane depolarization and insulin exocytosis. Other metabolic pathways believed to augment insulin secretion have yet to be fully elucidated. To study metabolic changes during GSIS, liquid chromatography with mass spectrometry was used to determine levels of 87 metabolites temporally following a change in glucose from 3 to 10 mM glucose and in response to increasing concentrations of glucose in the INS-1 832/13 ß-cell line. U-[(13)C]Glucose was used to probe flux in specific metabolic pathways. Results include a rapid increase in ATP/ADP, anaplerotic tricarboxylic acid cycle flux, and increases in the malonyl CoA pathway, support prevailing theories of GSIS. Novel findings include that aspartate used for anaplerosis does not derive from the glucose fuel added to stimulate insulin secretion, glucose flux into glycerol-3-phosphate, and esterification of long chain CoAs resulting in rapid consumption of long chain CoAs and de novo generation of phosphatidic acid and diacylglycerol. Further, novel metabolites with potential roles in GSIS such as 5-aminoimidazole-4-carboxamide ribotide (ZMP), GDP-mannose, and farnesyl pyrophosphate were found to be rapidly altered following glucose exposure.

Analysis of fatty acid composition in insulin secreting cells by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry.

A comprehensive two-dimensional gas chromatography (GC×GC) time-of-flight mass spectrometry method was developed for determination of fatty acids (irrespective of origin, i.e., both free fatty acids and fatty acids bound in sources such as triglycerides) in cultured mammalian cells. The method was applied to INS-1 cells, an insulin-secreting cell line commonly used as a model in diabetes studies. In the method, lipids were extracted and transformed to fatty acid methyl esters for analysis. GC×GC analysis revealed the presence of 30 identifiable fatty acids in the extract. This result doubles the number of fatty acids previously identified in these cells. The method yielded linear calibrations and an average relative standard deviation of 8.4% for replicate injections of samples and 12.4% for replicate analysis of different samples. The method was used to demonstrate changes in fatty acid content as a function of glucose concentration on the cells. These results demonstrate the utility of this method for analysis of fatty acids in mammalian cell cultures.

Reducing time and increasing sensitivity in sample preparation for adherent mammalian cell metabolomics.

A simple, fast, and reproducible sample preparation procedure was developed for relative quantification of metabolites in adherent mammalian cells using the clonal ß-cell line INS-1 as a model sample. The method was developed by evaluating the effect of different sample preparation procedures on high performance liquid chromatography- mass spectrometry quantification of 27 metabolites involved in glycolysis and the tricarboxylic acid cycle on a directed basis as well as for all detectable chromatographic features on an undirected basis. We demonstrate that a rapid water rinse step prior to quenching of metabolism reduces components that suppress electrospray ionization thereby increasing signal for 26 of 27 targeted metabolites and increasing total number of detected features from 237 to 452 with no detectable change of metabolite content. A novel quenching technique is employed which involves addition of liquid nitrogen directly to the culture dish and allows for samples to be stored at -80 °C for at least 7 d before extraction. Separation of quenching and extraction steps provides the benefit of increased experimental convenience and sample stability while maintaining metabolite content similar to techniques that employ simultaneous quenching and extraction with cold organic solvent. The extraction solvent 9:1 methanol: chloroform was found to provide superior performance over acetonitrile, ethanol, and methanol with respect to metabolite recovery and extract stability. Maximal recovery was achieved using a single rapid (∼1 min) extraction step. The utility of this rapid preparation method (∼5 min) was demonstrated through precise metabolite measurements (11% average relative standard deviation without internal standards) associated with step changes in glucose concentration that evoke insulin secretion in the clonal ß-cell line INS-1.

Rosiglitazone reduces renal and plasma markers of oxidative injury and reverses urinary metabolite abnormalities in the amelioration of diabetic nephropathy.

Recent studies suggest that thiazolidinediones ameliorate diabetic nephropathy (DN) independently of their effect on hyperglycemia. In the current study, we confirm and extend these findings by showing that rosiglitazone treatment prevented the development of DN and reversed multiple markers of oxidative injury in DBA/2J mice made diabetic by low-dose streptozotocin. These diabetic mice developed a 14.2-fold increase in albuminuria and a 53% expansion of renal glomerular extracellular matrix after 12 wk of diabetes. These changes were largely abrogated by administration of rosiglitazone beginning 2 wk after the completion of streptozotocin injections. Rosiglitazone had no effect on glycemic control. Rosiglitazone had similar effects on insulin-treated diabetic mice after 24 wk of diabetes. Podocyte loss and glomerular fibronectin accumulation, other markers of early DN, were prevented by rosiglitazone in both 12- and 24-wk diabetic models. Surprisingly, glomerular GLUT1 levels did not increase and nephrin levels did not decrease in the diabetic animals; neither changed with rosiglitazone. Plasma and kidney markers of protein oxidation and lipid peroxidation were significantly elevated in the 24-wk diabetic animals despite insulin treatment and were reduced to near-normal levels by rosiglitazone. Finally, urinary metabolites were markedly altered by diabetes. Of 1,988 metabolite features identified by electrospray ionization time of flight mass spectrometry, levels of 56 were altered more than twofold in the urine of diabetic mice. Of these, 21 were returned to normal by rosiglitazone. Thus rosiglitazone has direct effects on the renal glomerulus to reduce reactive oxygen species accumulation to prevent type 1 diabetic mice from development of DN.

Cerebrovascular responses to incremental exercise during hypobaric hypoxia: effect of oxygenation on maximal performance.

We sought to describe cerebrovascular responses to incremental exercise and test the hypothesis that changes in cerebral oxygenation influence maximal performance. Eleven men cycled in three conditions: 1) sea level (SL); 2) acute hypoxia [AH; hypobaric chamber, inspired Po(2) (Pi(O(2))) 86 Torr]; and 3) chronic hypoxia [CH; 4,300 m, Pi(O(2)) 86 Torr]. At maximal work rate (W(max)), fraction of inspired oxygen (Fi(O(2))) was surreptitiously increased to 0.60, while subjects were encouraged to continue pedaling. Changes in cerebral (frontal lobe) (C(OX)) and muscle (vastus lateralis) oxygenation (M(OX)) (near infrared spectroscopy), middle cerebral artery blood flow velocity (MCA V(mean); transcranial Doppler), and end-tidal Pco(2) (Pet(CO(2))) were analyzed across %W(max) (significance at P < 0.05). At SL, Pet(CO(2)), MCA V(mean), and C(OX) fell as work rate rose from 75 to 100% W(max). During AH, Pet(CO(2)) and MCA V(mean) declined from 50 to 100% W(max), while C(OX) fell from rest. With CH, Pet(CO(2)) and C(OX) dropped throughout exercise, while MCA V(mean) fell only from 75 to 100% W(max). M(OX) fell from rest to 75% W(max) at SL and AH and throughout exercise in CH. The magnitude of fall in C(OX), but not M(OX), was different between conditions (CH > AH > SL). Fi(O(2)) 0.60 at W(max) did not prolong exercise at SL, yet allowed subjects to continue for 96 +/- 61 s in AH and 162 +/- 90 s in CH. During Fi(O(2)) 0.60, C(OX) rose and M(OX) remained constant as work rate increased. Thus cerebral hypoxia appeared to impose a limit to maximal exercise during hypobaric hypoxia (Pi(O(2)) 86 Torr), since its reversal was associated with improved performance.