Chronic obstructive pulmonary disease in patients with end‐stage kidney disease on hemodialysis

The objectives of this study were to assess the prevalence of chronic obstructive pulmonary disease (COPD) in hemodialysis patients with spirometry and to examine the effects of fluid removal by hemodialysis on lung volumes. Patients ≥18 years at two Danish hemodialysis centers were included. Forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), and FEV₁/FVC ratio were measured with spirometry before and after hemodialysis. The diagnosis of COPD was based on both the GOLD criteria and the lower limit of normal criteria. There were 372 patients in treatment at the two centers, 255 patients (69%) completed spirometry before dialysis and 242 of these (65%) repeated the test after. In the initial test, 117 subjects (46%) had airflow limitation indicative of COPD with GOLD criteria and 103 subjects (40.4%) with lower limit of normal criteria; COPD was previously diagnosed in 24 patients (9%). Mean FVC and FEV₁ decreased mildly after dialysis (FVC: 2.84 to 2.79 L, P < 0.01. FEV₁: 1.97 to 1.93 L, P < 0.01) Hemodialysis did not affect the FEV₁/FVC ratio or number of subjects with airflow limitation indicative of COPD (113 vs. 120, P = 0.324; n = 242). COPD is a frequent and underdiagnosed comorbidity in patients on chronic hemodialysis. Spirometry should be considered in all patients on dialysis in order to address dyspnea adequately. Hemodialysis induced a small fall in mean FEV₁ and FVC, which was more pronounced in patients with little or no fluid removal, but the FEV₁/FVC ratio and the number of subjects with airflow limitation indicative of COPD were not affected by dialysis.     

In vitro maintenance of Schistosoma japonicum and surgical transfer from donor to na?ve recipient pigs

The insulin receptor (IR) is a membrane-bound glycoprotein composed of alpha and beta subunits derived from a common precursor. This processing is observed for both subtypes A and B of the IR and its physiological importance is poorly understood. In order to investigate the functional consequences of the absence of IR precursor cleavage, using site-directed mutagenesis of the hIRB cDNA, we have produced two mutants replacing the sequence Arg-Lys-Arg-Arg by either His-Lys-His-Arg or Arg-Lys-Arg-Ser. These two mutants, stably expressed in CHO, were structurally and functionally characterized in comparison to the wild-type human IR. These mutations result in the production of uncleaved receptors which are expressed normally at the cell surface. These receptors bind insulin with a normal affinity and activate the tyrosine-kinase resulting in normal phosphorylation of the receptors. These uncleaved receptors can mediate both the metabolic and mitogenic effects of insulin. These results provide evidence for a fully functional uncleaved insulin receptor of the B subtype (exon 11 + ) in contrast to the uncleaved A subtype (exon 11 -) described in the literature, which shows a reduced affinity for insulin and cannot therefore correctly transduce the insulin signal.     

Optical Detections From Worn and Unworn Titanium Compound Surfaces

Wear-induced roughness in terms of grooves, sharp ridges, and edges leads to scattering of the reflected light and leads unavoidably to a reduction of the optical signals in a standard specular geometry. However, by using a double-layer system consisting of titanium aluminum nitride (TiAlN) on top of a titanium nitride (TiN) layer we obtain an increase in the reflected light as a result of wear. The relative change of reflectance of light from the tribological TiAlN coated surface to the underlying layer of TiN is similar for non-worn surfaces and for surfaces exposed to an abrasive wear process. The induced roughness reduces the signals from worn samples, in a standard specular geometry, by up to 30% compared with unworn samples. Our model system of TiAlN coatings on top of ‘optical’ signal layers of TiN deposited on a 100Cr6 steel substrate, was exposed to a reciprocating wear process with up to 10⁵ repetitive cycles in a linear tribometer. The worn TiAlN layers of thicknesses up to 3 μm, with strongly developed grooves and ridges, were subsequently used for the reflectance measurements. The results show that optical reflectance monitoring is a potential technique for intelligent determination of a residual thickness of realistic tribological coatings prior to complete wear.     

Ligature-induced marginal inflammation around osseointegrated implants and ankylosed teeth: stereologic and histologic observations in cynomolgus monkeys (Macaca fascicularis)

The aim of the investigation was to provide quantitative and qualitative histologic data on marginal inflammation around osseointegrated implants. The significance of the lack of a periodontal ligament in the initial breakdown phase of supporting tissues in implants was examined by comparing stereologic and histologic manifestations of ligature-induced marginal inflammation around osseointegrated implants with those around ankylosed and normal control teeth in 8 cynomolgus monkeys (Macaca fascicularis). Clinical and radiographic findings have been reported elsewhere. The marginal connective tissue around ligated implants was infiltrated by a significantly increased total number of lymphocytes, plasma cells, and neutrophils compared to non-ligated implants and teeth. The total number of lymphocytes around ligated implants was significantly higher than around ligated ankylosed and normal control teeth. There were, however, no significant differences in the total number of plasma cells and neutrophils within the ligated group. Osteoclasts were exclusively observed around ligated implants and ankylosed teeth. Although variations in microbiota and susceptibility of different jaw positions to periodontal break-down may influence the results of the present study, the results seem to substantiate the theory that marginal inflammation around implants and ankylosed teeth may have more serious implications than does marginal inflammation around teeth with a periodontal ligament. Since presence of osteoclasts was not related to the absence of cervical cementum with inserting gingival fibers around ligated ankylosed teeth, the increased susceptibility of bone loss of implants is probably not caused by the absence of these tissue components. In contrast, the histologic observations seem to support that the increased susceptibility for bone loss around implants may be related to the absence of a periodontal ligament.     

Information assurance in biomedical informatics systems

The DHS recognizes that the progression from data to information to knowledge and subsequently to wisdom is a key to robust, reliable, and resilient biomedical informatics systems. The systems that enable this progression are increasingly complex. Frequently these systems are so complex that no one, including their designers, understands all their interactions and the implications of changes. This complexity combined with closely coupled systems operations creates critical systems that are both fragile and brittle. In the systems, failure of a single component may adversely affect the integrity, confidentiality, and availability of many critical systems. National security efforts cannot afford to place the security of the homeland on the backs of brittle systems.     

Sputtering of Surfaces of the Solid Hydrogens

Sputtering of the solid hydrogens by electrons and ions exhibits features that may be related to quantum properties of these solids, i.e. a drastic enhancement of the yield for electron–bombarded thick deuterium films and a thermal peak at low ejection energies in the energy distribution of the sputtered particles.     

Direct plasma metabolite analysis of positron emission tomography radioligands by micellar liquid chromatography with radiometric detection

Determination of radio-metabolites in plasma samples taken during a positron emission tomography (PET) study is an important component in the pharmacokinetic evaluation of PET radioligands. We have developed and validated a new analytical procedure for the plasma metabolite analysis of PET radioligands based on micellar liquid chromatography using an anionic surfactant mobile phase. Chromatographic separation was performed on an octadecyl semipreparative column (10 mm I.D. × 160 mm, 10 μm) using 100 mM sodium dodecyl sulfate (SDS) and 1-butanol in 10 mM sodium-phosphate (pH 7.2) at a flow rate of 5 mL/min. The samples taken from monkey or human plasma during PET measurements were directly injected into a liquid chromatographic (LC) system coupled to an online radiometric detector under micellar conditions using 1-2% (v/v) 1-butanol mobile phase to remove plasma proteins and concentrate the analytes at the column head. At 2 min, mobile phase was changed to elute and separate PET radioligand and its radiometabolites with high peak capacity under high submicellar conditions (10-25% 1-butanol). This procedure allowed direct plasma injection (up to 2 mL) into the LC column without any pretreatment with a short analysis-time of 8-10 min. Satisfactory reproducibility, linearity, sensitivity, accuracy and recovery were obtained in the validation study. The developed method was successfully applied to study the metabolism for diverse groups of PET radioligands and provided reliable determination of PET radioligands in human and monkey plasma. This method is advantageous in terms of simplifying and shortening the processes required to analyze short-lived radioligands as well as in providing a more accurate estimation of the metabolite corrected input function, especially for the radioligands with lower recoveries or degradation potential during the deproteination process in a conventional procedure.