Preliminary demonstration of benchtop NMR metabolic profiling of feline urine: chronic kidney disease as a case study.

OBJECTIVE: The use of benchtop metabolic profiling technology based on nuclear magnetic resonance (NMR) was evaluated in a small cohort of cats with a view to applying this as a viable and rapid metabolic tool to support clinical decision making. RESULTS: Urinary metabolites were analysed from four subjects consisting of two healthy controls and two chronic kidney disease (CKD) IRIS stage 2 cases. The study identified 15 metabolites in cats with CKD that were different from the controls. Among them were acetate, creatinine, citrate, taurine, glycine, serine and threonine. Benchtop NMR technology is capable of distinguishing between chronic kidney disease case and control samples in a pilot feline cohort based on metabolic profile. We offer perspectives on the further development of this pilot work and the potential of the technology, when combined with sample databases and computational intelligence techniques to offer a clinical decision support tool not only for cases of renal disease but other metabolic conditions in the future.

Baseline Hemodynamic Impairment and Future Stroke Risk in Adult Idiopathic Moyamoya Phenomenon: Results of a Prospective Natural History Study.

BACKGROUND AND PURPOSE: The purpose was to test the hypothesis that increased oxygen extraction fraction (OEF), a marker of severe hemodynamic impairment measured by positron emission tomography, is an independent risk factor for subsequent ischemic stroke in this population. METHODS: Adults with idiopathic moyamoya phenomena were recruited between 2005 and 2012 for a prospective, multicenter, blindly adjudicated, longitudinal cohort study. Measurements of OEF were obtained on enrollment. Subjects were followed up for the occurrence of ipsilateral ischemic stroke at 6-month intervals. Patients were censored at the time of surgical revascularization or at last follow-up. The primary analysis was time to ischemic stroke in the territory of the occlusive vasculopathy. RESULTS: Forty-nine subjects were followed up during a median of 3.7 years. One of 16 patients with increased OEF on enrollment had an ischemic stroke and another had an intraparenchymal hemorrhage. Three of 33 patients with normal OEF had an ischemic stroke. On a per-hemisphere basis, 21 of 79 hemispheres with moyamoya vasculopathy had increased OEF at baseline. No ischemic strokes and one hemorrhage occurred in a hemisphere with increased OEF (n=21). Sixteen patients (20 hemispheres), including 5 with increased OEF at enrollment, were censored at a mean of 5.3 months after enrollment for revascularization surgery. CONCLUSIONS: The risk of new or recurrent stroke was lower than expected. The low event rate, low prevalence of increased OEF, and potential selection bias introduced by revascularization surgery limit strong conclusions about the association of increased OEF and future stroke risk. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00629915.

The Effect of Cobalt-Sublattice Disorder on Spin Polarisation in Co2FexMn1-xSi Heusler Alloys.

In this work we present a theoretical study of the effect of disorder on spin polarisation at the Fermi level, and the disorder formation energies for Co2FexMn1-xSi (CFMS) alloys. The electronic calculations are based on density functional theory with a Hubbard U term. Chemical disorders studied consist of swapping Co with Fe/Mn and Co with Si; in all cases we found these are detrimental for spin polarisation, i.e., the spin polarisation not only decreases in magnitude, but also can change sign depending on the particular disorder. Formation energy calculation shows that Co-Si disorder has higher energies of formation in CFMS compared to Co2MnSi and Co2FeSi, with maximum values occurring for x in the range 0.5-0.75. Cross-sectional structural studies of reference Co2MnSi, Co2Fe0.5Mn0.5Si, and Co2FeSi by Z-contrast scanning transmission electron microscopy are in qualitative agreement with total energy calculations of the disordered structures.

Neurosurgical treatment of progressive posthemorrhagic ventricular dilation in preterm infants: a 10-year single-institution study.

OBJECT: Intraventricular hemorrhage (IVH) and progressive posthemorrhagic ventricular dilation (PPHVD) may result in significant neurological morbidity in preterm infants. At present, there is no consensus regarding the optimal timing or type of neurosurgical procedure to best treat PPHVD. Conflicting data exist regarding the relative risks and benefits of two commonly used temporizing neurosurgical procedures (TNPs), ventricular access devices ([VADs] or ventricular reservoirs) versus ventriculosubgaleal (VSG) shunts. This study was designed to address this issue. METHODS: This is a single-center, 10-year retrospective review of all preterm infants admitted to the St. Louis Children's Hospital neonatal intensive care unit (NICU) with Papile Grade III-IV IVH. The development of PPHVD and the requirement for and type of TNP were recorded. Rates of TNP complication, ventriculoperitoneal (VP) shunt implantation, shunt infection, and mortality rates were used to compare the efficacy and limitations of each TNP type. RESULTS: Over this 10-year interval, 325 preterm infants with Grade III-IV IVH were identified, with trends showing an increasing number of affected infants annually, and an increasing number of TNPs were required annually. Ninety-five (29.2%) of the 325 infants underwent a TNP for PPHVD (65 VADs, 30 VSG shunts). The rate of permanent VP shunt implantation for all TNPs was 72.6% (69 of 95 infants). Forty-nine (75.4%) of the 65 infants treated with VADs and 20 (66.7%) of the 30 treated with VSG shunts required VP shunts (p = 0.38). There was no statistical difference between VAD or VSG shunt with regard to TNP-related infection (p = 0.57), need for TNP revision (p = 0.16), subsequent shunt infection (p = 0.77), shunt revision rate (p = 0.58), or mortality rate (p = 0.24). CONCLUSIONS: Rates of IVH and PPHVD observed at the authors' center have increased over time. In contrast to recent literature, the results from the current study did not demonstrate a difference in complication rate or requirement for permanent VP shunt placement between VADs and VSG shunts. Definitive conclusions will require a larger, prospective trial.

Cerebral hemodynamics as a predictor of stroke in adult patients with moyamoya disease: a prospective observational study.

Moyamoya disease is an obliterative vasculopathy of the large arteries at the base of the brain. In the US, it most commonly affects women in their 3rd and 4th decades of life, frequently causing ischemic stroke. The natural history of this disorder is not well described. It is very likely that hemodynamic factors play an important role in the risk of future stroke, as has been established in atherosclerotic carotid occlusive disease. The authors describe an ongoing, prospective observational study designed to test the hypothesis that increased oxygen extraction in the cerebral hemisphere beyond the occlusive lesion is a predictor of subsequent risk of ipsilateral stroke in medically treated patients with moyamoya phenomenon. On enrollment, all patients undergo regional measurements of cerebral oxygen extraction fraction (OEF) with PET. Information on baseline clinical, laboratory, epidemiological, and angiographic risk factors are obtained at the time of the PET study. Decisions regarding surgery are made by the treating physicians based on clinical information while being blinded to PET data. Patients undergo follow-up at 6-month intervals to determine the subsequent risk of ipsilateral stroke. All patients will return at 1 and 3 years for repeat PET studies. Secondary, exploratory, aims of this longitudinal and blinded study are to determine other predictive factors for stroke in this population; to determine preliminary estimates of the effects of different medical treatment regimens in this population; to determine the temporal changes in hemodynamic impairment in medically treated patients; to determine the effects of surgery on hemodynamic impairment in the subset of patients who undergo surgical revascularization; and to obtain estimates of surgical complication rates for patients with and without hemodynamic impairment.

Assessment of efficacy of transcutaneous electrical nerve stimulation for pain management during office-based flexible cystoscopy.

OBJECTIVES: To evaluate the efficacy of transcutaneous electrical nerve stimulation (TENS) for its effectiveness in eliminating or minimizing discomfort during office-based flexible cystoscopy. METHODS: A total of 148 patients were prospectively randomized into one of three groups: flexible cystoscopy with no analgesics, a placebo TENS, or an activated TENS. The patient data collected included patient parameters, number of previous flexible cystoscopies, visual analog pain scores during and after the procedure, surgeon's difficulty rating of procedure, and International Prostate Symptom Score before and 24 hours after the procedure. RESULTS: No statistically significant difference was found among the three groups regarding patient parameters. The visual analog pain scores were similar before and after the procedure. At 30 seconds, the mean visual analog scale score for the control group, placebo group, and TENS study group was 3.73, 3.65, and 3.52, respectively (control versus placebo, control versus active, and placebo versus active: P = 0.97, 0.29, and 0.53, respectively). At 1 and 5 minutes, the corresponding scores were 3.44, 4.37, and 3.50 (P = 0.88, P = 0.99, and P = 0.99) and 0.86, 1.23, and 0.88 (P = 0.97, P = 0.35, and P = 0.56), respectively. The surgeon's mean difficulty rating for the control procedures was 1.08 and for the placebo group was 2.30 (P = 0.02). CONCLUSIONS: All patients undergoing flexible cystoscopy in the office setting experienced discomfort. The TENS device provided no significant benefit for pain. The trend toward greater pain scores in the control group could be attributed to the greater degree of difficulty.