Endothelin-1 levels in induced sputum samples from asthmatic and normal subjects

BACKGROUND: Endothelin-1 (ET-1) is a potent bronchoconstrictor which may have a role in the pathogenesis of asthma. The levels of ET-1 in saliva, induced sputum, and plasma from asthmatic and non-asthmatic subjects were compared. METHODS: Sputum induction was performed on 28 asthmatic subjects and nine normal volunteers. ET-1 levels were measured in plasma, saliva, and sputum samples and reversed phase high performance liquid chromatography (RP-HPLC) was performed on saliva and sputum samples. RESULTS: ET-1 was present in the following order of concentration in both normal and asthmatic subjects: saliva > sputum > plasma (saliva, median 30.1 and 23.9 pg/ ml, respectively; sputum, median 15.5 and 11.2 pg/ml; plasma, median 3.1 and 3.6 pg/ ml). There were no differences between asthmatic and normal subjects in the levels of ET-1 in each fluid. The levels of ET-1 in asthmatic subjects were not influenced by whether or not they were taking inhaled steroids. RP-HPLC of sputum and saliva confirmed the presence of ET-1 in these fluids. CONCLUSIONS: Levels of ET-1 can be measured in saliva and sputum obtained by sputum induction in asthmatic and healthy subjects and, although no difference was found in basal levels of ET-1 in sputum, saliva and plasma between normal subjects and asthmatics without bronchoconstriction, it is apparent that ET-1 is produced or released locally within the respiratory tract in concentrations higher than those in plasma.     

Neuropsychiatric systemic lupus erythematosus and the syndrome of inappropriate secretion of antidiuretic hormone: a case report with very late onset systemic lupus erythematosus

The syndrome of inappropriate secretion of antidiuretic hormone (SIADH) associated with neuropsychiatric lupus (NP-SLE) is rare. We report a case of SIADH associated with the new onset of SLE in an 88-yr-old female. The unique features of this case include the extreme age of onset of SLE presenting with neuropsychiatric manifestations and positive antiribosomal P antibody titres. Both the NP manifestations of SLE and SIADH were highly correlated with the SLE disease activity. This case illustrates a novel presentation of NP-SLE with SIADH which may develop due to antibody-mediated hypothalamic dysfunction.     

Crushed sunflower, flax, or canola seeds in lactating dairy cow diets: Effects on methane production, rumen fermentation, and milk production

The objective of this study was to investigate the potential of reducing enteric methane production from dairy cows by incorporating into the diet various sources of long-chain FA varying in their degree of saturation and ruminal availability. The experiment was conducted as a crossover design with 16 lactating dairy cows maintained in 2 groups and fed 4 dietary treatments in four 28-d periods. Eight ruminally cannulated primiparous cows (96 ± 18 d in milk) were assigned to group 1 and 8 multiparous cows (130 ± 31 d in milk) were assigned to group 2. The dietary treatments were: 1) a commercial source of calcium salts of long-chain fatty acids (CTL), 2) crushed sunflower seeds (SS), 3) crushed flaxseed (FS), and 4) crushed canola seed (CS). The oilseeds added 3.1 to 4.2% fat to the diet (DM basis). All 3 oilseed treatments decreased methane production (g/d) by an average of 13%. When corrected for differences in dry matter intake (DMI), compared with CTL, methane production (g/kg of DM intake) was decreased by feeding FS (−18%) or CS (−16%) and was only numerically decreased (−10%) by feeding SS. However, compared with the CTL, feeding SS or FS lowered digestible DMI by 16 and 9%, respectively, because of lowered digestibility. Thus, only CS lowered methane per unit of digestible DM intake. Feeding SS and CS decreased rumen protozoal counts, but there were no treatment effects on mean ruminal pH or total volatile fatty acid concentration. Milk efficiency (3.5% fat corrected milk/DMI), milk yield, and component yield and concentrations were not affected by oilseed treatments. The study shows that adding sources of long-chain fatty acids to the diet in the form of processed oilseeds can be an effective means of reducing methane emissions. However, for some oilseeds such as SS or FS, the reduction in methane can be at the expense of diet digestibility. The use of crushed CS offers a means of mitigating methane without negatively affecting diet digestibility, and hence, milk production.     

Coinfection of macaques with simian immunodeficiency virus and simian T cell leukemia virus type I: effects on virus burdens and disease progression

To test the hypothesis that coinfection with human immunodeficiency virus (HIV) and human T cell leukemia/lymphoma virus types I or II (HTLV-I or -II) accelerates progression to AIDS, pig-tailed macaques were inoculated with the simian counterparts, SIV and STLV-I. During 2 years of follow-up of singly and dually infected macaques, no differences in SIV burdens, onset of disease, or survival were detected. However, in the first coinfected macaque that died of AIDS (1 year after infection), >50% of CD4+ and CD8+ lymphocytes expressed CD25. On the basis of the low incidence of HTLV-I- and STLV-I-associated disease during natural infections, this early evidence of neoplastic disease was unexpected. While these results demonstrate that coinfection with SIV and STLV-I has no influence on the development of immunodeficiency disease, they do establish a reliable macaque model of persistent STLV-I infection.     

Medullary metastasis causing impairment of respiratory pressure output with intact respiratory rhythm

BACKGROUND: Vascular access failure is an important cause of morbidity in end-stage renal failure patients on hemodialysis. Currently, little is known about risk factors that predispose certain hemodialysis patients to recurrent access thrombosis. Hyperhomocysteinemia (common in patients with renal failure) predisposes people with normal renal function to recurrent and early-onset venous thrombosis, although the effect on vascular access thrombosis is currently unknown. Previous studies have suggested that high titers of IgG anticardiolipin antibody (IgG-ACA) predispose hemodialysis patients to access thrombosis. This cross sectional study was designed to assess for an association between two predictive variables, hyperhomocysteinemia and elevated titers of IgG-ACA, and vascular access thrombosis in patients undergoing chronic hemodialysis. METHODS: Risk factors for vascular access thrombosis were documented, and the number of episodes of access thrombosis was recorded for the previous three years in patients undergoing hemodialysis. Midweek predialysis total homocysteine and IgG-ACA levels were measured in all subjects. RESULTS: Of the 118 patients who were enrolled, 75.4% had a native arteriovenous fistula. Episodes of vascular access thrombosis were recorded for the previous three years; 34 (28.8%, 95% CI 20.9 to 37.9%) patients had 72 episodes of access thrombosis over the period of risk. Mean homocysteine levels were not significantly different between these 34 patients (28.6 micromol/liter, 95% CI 24.5 to 32.7) and the patients who had no episodes of graft thrombosis (29.8 micromol/liter, 95% CI 26.7 to 32.9). Sixty-seven unselected patients had IgG-ACA levels drawn for analysis, and all assays were negative. The only variable that was associated with a higher risk for graft thrombosis was the type of vascular access placed (odds ratio 4.0, 95% CI 1.6 to 9.6 for patients with a synthetic graft compared with those with an arteriovenous fistula). CONCLUSIONS: No association was found between homocysteine levels or anticardiolipin antibody and vascular access thrombosis in our patient population.     

Composition dependence of ternary Pt–Ni–Cr catalyst activity for the methanol electro-oxidation reaction

Various compositions of binary and ternary Pt–Ni–Cr alloys were investigated as catalysts for the methanol electro-oxidation reaction (MOR). Among the binary (Pt₂₈Ni₇₂/C and Pt₂₈Cr₇₂/C) and ternary Pt–Ni–Cr catalysts (Pt₂₈Ni₃₆Cr₃₆/C, Pt₂₂Ni₃₉Cr₃₉/C, Pt₃₃Ni₃₁Cr₃₆/C, and Pt₃₃Ni₃₆Cr₃₁/C) examined, the Pt₂₈Ni₃₆Cr₃₆/C composition exhibited the highest MOR mass activity (4.42 A g_cat.⁻¹) in the as-prepared version, which was higher than the 3.58 A g_cat.⁻¹ value of the PtRu/C catalyst after 60 min of chronoamperometry testing. The order of mass activity for the MOR was Pt₂₈Ni₃₆Cr₃₆/C > Pt₃₃Ni₃₆Cr₃₁/C > Pt₂₂Ni₃₉Cr₃₉/C > Pt₃₃Ni₃₁Cr₃₆/C > Pt₂₈Cr₇₂/C > Pt₂₈Ni₇₂/C, which was slightly changed to Pt₂₈Ni₃₆Cr₃₆/C > Pt₂₂Ni₃₉Cr₃₉/C > Pt₃₃Ni₃₆Cr₃₁/C > Pt₃₃Ni₃₁Cr₃₆/C > Pt₂₈Cr₇₂/C > Pt₂₈Ni₇₂/C after a conditioning process. The effect of anodic conditioning was also studied. A combination of X-ray diffraction, cyclic voltammetry, and chronoamperometry experiments revealed that the conditioning process caused dissolution and an oxidation state change of metallic Ni and Cr₂O₃ in the binary catalysts. The higher MOR mass activities of the ternary catalysts compared to the binary ones is attributed to co-alloying of Ni and Cr, leading to exposure of more Pt on the catalyst surface without reducing specific activities of the catalysts. The results of this study also correlate well with a prior ranking of catalytic activity of the same compositions in the form of thin film catalysts that we processed and evaluated by a high-throughput combinatorial approach [J.S. Cooper, M.K. Jeon, P.J. McGinn, Electrochem. Commun. 10 (2008) 1545–1547].     

Twin-boundary pinning and flux flow in zone-melt-textured YBa2Cu3O7-δ crystals

Using a microwave (13 GHz) technique which is sensitive to field-induced changes in the surface resistance, we have observed twin-boundary pinning in zone-melt-textured crystals of YBa₂Cu₃O₇-δ. With the rotation of a static 1.9-T field applied in thea-b plane, the surface resistanceR _s exhibits minima at 90° intervals. The twin-boundary minima are shown to be connected to the orientation of the crystalline axes of the sample. The resistance minima are observed superimposed on a flux-flow response over the temperature range ofT _c to the lowest temperature attempted. Substantial flux mobility is observed to the lowest temperatures. The angular dependence of the flux-flow response at low temperatures is consistent with the “brick” model for local intergranular conductivity, which provides for an in-plane isotropic component.     

Eastern Mediterranean sapropels: chemical structure, deposition and relation to oil-shales

Ten sapropels, deposited in three different basins of the eastern Mediterranean since the Miocene and selected from cores of the Deep Sea Drilling Programme have been characterised by elemental analysis; fluorescence, infra-red and NMR spectrometry, by pyrolysis-gas chromatography/mass spectrometry and by catalytic hydrogenation at moderately high pressure. The sapropels are Types I-II kerogens, which have been oxidised, probably by a front experienced, since their deposition. Only one, from the Cretan basin, contained structures from lignin. The others, typical of a marine deposition, possessed aromaticities of about 0.2. Their detailed organic structures are described.     

Characterization of Calcium Titanate–Magnesium Titanate Eutectic by Scanning Microwave Microscopy

Microstructure and dielectric properties in a CaTiO₃ (CT)–MgTiO₃ (MT) diffusion couple were studied by scanning electron microscopy (SEM) and near-field scanning microwave microscopy (SMM). Complex microstructures containing Mg₂TiO₄ (M2T) and MgTi₂O₅ (MT2) phases as well as eutectic structures of CT–MT and MT2–CT developed during cooling from the melt. Variations in the local dielectric properties observed in SMM images are correlated with the microstructures characterized by SEM/EDS. The SMM characterization clearly distinguished low-dielectric-constant MT and high-dielectric-constant CT phases. The M2T, MT, and MT2 phases have similar dielectric properties, and were more difficult to distinguish in the SMM. The phase development during melting and solidification, and SMM imaging limitations are discussed.     

Microstructure and Dielectric Properties of a LaAlO3–TiO2 Diffusion Couple

Near-field scanning microwave microscopy was applied to investigate the dielectric properties and microstructure in a polycrystalline LaAlO₃–TiO₂ diffusion couple, which included three regions containing different phases and microstructures. Relatively low (La₂Ti₄Al₁₈O₃₈), high (α-La_2/3TiO₃), and intermediate (La₄Ti₉O₂₄) dielectric constant phases were distinguished at the inter-diffusion interface in optical, backscattered electron scanning electron microscopy, and scanning microwave microscopy (SMM) images. The relative ranking of dielectric constants based on SMM examination was as follows: TiO₂>α-La_2/3TiO₃>La₄Ti₉O₂₄>LaAlO₃>La₂Ti₄Al₁₈O₃₈. La_2/3TiO₃ and LaAlO₃ will form solid solutions in the LaAlO₃-rich region. The reaction paths leading to phase development are discussed.