Polarization Dependence of Anomalous X-ray Scattering in Orbital Ordered Manganites

In order to determine types of the orbital ordering in manganites, we study theoretically the polarization dependence of the anomalous X-ray scattering which is caused by the anisotropy of the scattering factor. The general formulae of the scattering intensity in the experimental optical system is derived and the atomic scattering factor is calculated in the microscopic electronic model. By using the results, the X-ray scattering intensity in several types of the orbital ordering is numerically calculated as a function of azimuthal and analyzer angles.Comment: 9 pages, 7 figure

THE POTENTIAL THERAPEUTIC ROLE OF POTASSIUM CHANNEL MODULATORS IN ASTHMA AND CHRONIC OBSTRUCTIVE PULMONARY DISEASE

The involvement of a number of potassium channels has been reported in respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD), supporting the idea that potassium channel modulating agents may help control it. Experimental evidence and preclinical models suggest that ATP-dependent K(+) (K(ATP)) channel openers, big-conductance K(+) (BK(CA)) channel openers, and intermediate-conductance K(+) (IK(CA)) channel blockers may be the most effective agents for treating asthma and COPD. Modulation of potassium channels by these agents may produce beneficial effects such as bronchodilation, a reduction in airways hyperresponsiveness (AHR), a reduction in cough and mucus production and an inhibition in airway inflammation and remodelling. The aim of this paper is to investigate the role of K(+) channel modulation in the pathogenesis, progression and exacerbation of asthma and COPD, and to review the evidence suggesting that K(+) channel modulators may be a valuable treatment option for these respiratory diseases

Plasma homocysteine and folate levels in patients with chronic plaque psoriasis

Background Hyperhomocysteinaemia is a well-known risk factor for cardiovascular diseases. Patients with severe chronic plaque psoriasis have a higher risk of death due to arterial and/or venous thrombosis. Objectives To investigate the relationship among plasma homocysteine and folate levels and severity of chronic plaque psoriasis in a selected cohort of patients with psoriasis without known risk factors for acquired hyperhomocysteinaemia. Methods We performed a case-control study in 40 patients with chronic plaque psoriasis and 30 age- and sex-matched healthy controls. Cases and controls were selected excluding individuals with conditions or diseases associated with acquired hyperhomocysteinaemia, and were also asked to stop alcohol and coffee consumption for I week before blood sampling. The plasma levels of homocysteine and folic acid were measured and were correlated with the severity of psoriasis (Psoriasis Area and Severity Index, PASI). Results Patients with psoriasis had plasma homocysteine levels higher than controls (mean SD 16.0 +/- 5.6 vs. 10.4 +/- 4.7 mu mol L-1; P < 0.001). Conversely, folic acid levels were lower in patients with psoriasis compared with controls (mean SD 3.6 +/- 1.7 vs. 6.5 +/- 1.7 nmol L-1; P < 0.001). Plasma homocysteine levels in patients with psoriasis correlated directly with disease severity (PASI) and inversely with folic acid levels. Plasma folic acid levels were inversely correlated with the PASI. No abnormalities of plasma vitamin B-6 and B-12 were found. Conclusions Patients with psoriasis may have a tendency to hyperhomocysteinaemia, which may predispose to higher cardiovascular risk. Dietary modification of this risk factor appears relevant to the global management of patients with moderate to severe psoriasis

Cardiac arrhythmia monitoring during bronchial provocation test with methacholine.

Study objectives: During a bronchial provocation test (BPT), the performance of maximal inspiratory-expiratory maneuvers, causing abrupt and marked shifts in intrathoracic pressure, may increase the risk of cardiac arrhythmias. Moreover, the inhalation of methacholine (MCh), a cholinergic agonist agent, could favor the development of unwelcome cardiovascular events, namely, cardiac arrhythmias. Subjects and methods: We studied the number and severity of cardiac arrhythmias by ECG-Holter monitoring before, during, and after BPTs with MCh challenge in a group of 46 consecutive nonselected subjects (28 men and 18 women) with clinical indications for BPT, without preexisting cardiovascular diseases, and not receiving arrhythmogenic drugs. The subjects performed a routine pulmonary function test (PFT), followed by BPT, during ECG-Holter monitoring. Determination of the serum potassium concentration, a baseline arterial blood gas analysis, and monitoring of oxyhemoglobin saturation also were performed. Results: We found no significant increase in the number of supraventricular and ventricular arrhythmias during the performance of PFTs and of BPTs with MCh in the subjects, either with or without bronchial hyperresponsiveness (BHR). However, during the performance of BPTs, we observed a significant reduction in mean heart rate. Conclusions: Our results indicate that the performance of PFTs and BPTs with MCh does not increase the cardiac arrhythmogenic risk in subjects without cardiovascular diseases, as well as in those with BHR, suggesting that these tests are safe to perform in most subjects

Plasma homocysteine and folate levels in patients with chronic plaque psoriasis.

Background Hyperhomocysteinaemia is a well-known risk factor for cardiovascular diseases. Patients with severe chronic plaque psoriasis have a higher risk of death due to arterial and/or venous thrombosis. Objectives To investigate the relationship among plasma homocysteine and folate levels and severity of chronic plaque psoriasis in a selected cohort of patients with psoriasis without known risk factors for acquired hyperhomocysteinaemia. Methods We performed a case–control study in 40 patients with chronic plaque psoriasis and 30 age- and sex-matched healthy controls. Cases and controls were selected excluding individuals with conditions or diseases associated with acquired hyperhomocysteinaemia, and were also asked to stop alcohol and coffee consumption for 1 week before blood sampling. The plasma levels of homocysteine and folic acid were measured and were correlated with the severity of psoriasis (Psoriasis Area and Severity Index, PASI). Results Patients with psoriasis had plasma homocysteine levels higher than controls (mean ± SD 16Æ0 ± 5Æ6 vs. 10Æ4 ± 4Æ7 lmol L)1; P < 0Æ001). Conversely, folic acid levels were lower in patients with psoriasis compared with controls (mean ± SD 3Æ6 ± 1Æ7 vs. 6Æ5 ± 1Æ7 nmol L)1; P < 0Æ001). Plasma homocysteine levels in patients with psoriasis correlated directly with disease severity (PASI) and inversely with folic acid levels. Plasma folic acid levels were inversely correlated with the PASI. No abnormalities of plasma vitamin B6 and B12 were found. Conclusions Patients with psoriasis may have a tendency to hyperhomocysteinaemia, which may predispose to higher cardiovascular risk. Dietary modification of this risk factor appears relevant to the global management of patients with moderate to severe psoriasis

Plasma homocysteine and folate levels in patients with chronic plaque psoriasis.

Background: Hyperhomocysteinaemia is a well-known risk factor for cardiovascular diseases. Patients with severe chronic plaque psoriasis have a higher risk of death due to arterial and/or venous thrombosis. Objectives: To investigate the relationship among plasma homocysteine and folate levels and severity of chronic plaque psoriasis in a selected cohort of patients with psoriasis without known risk factors for acquired hyperhomocysteinaemia. Methods: We performed a case-control study in 40 patients with chronic plaque psoriasis and 30 age- and sex-matched healthy controls. Cases and controls were selected excluding individuals with conditions or diseases associated with acquired hyperhomocysteinaemia, and were also asked to stop alcohol and coffee consumption for 1 week before blood sampling. The plasma levels of homocysteine and folic acid were measured and were correlated with the severity of psoriasis (Psoriasis Area and Severity Index, PASI). Results: Patients with psoriasis had plasma homocysteine levels higher than controls (mean \ub1 SD 16.0 \ub1 5.6 vs. 10.4 \ub1 4.7 \u3bcmol L-1; P < 0.001). Conversely, folic acid levels were lower in patients with psoriasis compared with controls (mean \ub1 SD 3.6 \ub1 1.7 vs. 6.5 \ub1 1.7 nmol L-1; P < 0.001). Plasma homocysteine levels in patients with psoriasis correlated directly with disease severity (PASI) and inversely with folic acid levels. Plasma folic acid levels were inversely correlated with the PASI. No abnormalities of plasma vitamin B6 and B12 were found. Conclusions: Patients with psoriasis may have a tendency to hyperhomocysteinaemia, which may predispose to higher cardiovascular risk. Dietary modification of this risk factor appears relevant to the global management of patients with moderate to severe psoriasis. \ua9 2006 The Authors

C-reactive protein and markers for thrombophilia in patients with chronic plaque psoriasis

Chronic plaque psoriasis is associated to an increased risk of cardiovascular events. The aim of our study is to test patients with psoriasis for common markers of acquired and inherited thrombophilia. A cross-sectional study on 172 patients with psoriasis and 198 controls was carried out. The plasma levels of coagulation protein C, coagulation protein S, homocysteine, folic acid, C-reactive protein (CRP) and fibrinogen as well as activated protein C resistance and antithrombin III activity, were measured. CRP and homocysteine levels were higher in patients with psoriasis than in controls (5.9 +/- 7.1 vs 3.1 +/- 2.4 mg/L, p=0.0003 and 16.3 +/- 12.8 vs 10.4 +/- 4.6 umol/L, p=0.0001; mean +/- SD) whereas folic acid was lower in psoriatic patients compared to controls (4.3 +/- 7.2 vs 12.6 +/- 7.9 p=0.006). Levels of coagulation protein C, coagulation protein S, fibrinogen as well as activated protein C resistance, antithrombin III activity were within normal ranges both in cases and controls. In a multivariate regression analysis, psoriasis severity was an independent predictor of higher CRP. In conclusion, high levels of serum CRP and homocysteine were found in patients with psoriasis, related to the severity of the disease. These data suggest that the increased risk of thrombotic cardiovascular events observed in psoriasis patients should be ascribed to an acquired rather than inherited thrombophilic status