Vitamin D supplementation reduces airway hyperresponsiveness and allergic airway inflammation in a murine model.

BACKGROUND: Asthma is a chronic disease associated with airway hyperresponsiveness (AHR), airway obstruction and airway remodelling. NF-κB is a transcriptional factor that regulates and co-ordinates the expression of various inflammatory genes. The NF-κB subunits, p50 and Rel-A, are translocated to the nucleus by importin α3 and importin α4. There is growing evidence that vitamin D is a potent immunomodulator. However, the evidence for beneficial or adverse effects of vitamin D in asthma is still unclear. OBJECTIVE: In this study, we examined the effect of vitamin D status on AHR, airway inflammation and cytokines in the bronchoalveolar lavage fluid (BALF) in a murine model of allergic asthma. METHODS: Female BALB/c mice were fed with special vitamin D-deficient or vitamin D-sufficient (2000 IU/kg) or vitamin D-supplemented (10,000 IU/kg) diet for 13 weeks. Mice were sensitized and challenged with ovalbumin (OVA). The effect of vitamin D on lung histology, AHR, T regulatory cells (Tregs) and BALF cytokines was examined. The expression of importin-α3 and Rel-A in the lung of OVA-sensitized mice was analysed using immunofluorescence. RESULTS: Vitamin D deficiency was associated with higher AHR in OVA-sensitized and challenged mice than those in vitamin D-sufficient mice. This was accompanied with marked signs of airway remodelling, high BALF eosinophilia, increased BALF pro-inflammatory cytokines, reduced BALF IL-10 levels, reduced blood Tregs, increased expression of importin-α3 and Rel-A in the lung tissue. Vitamin D supplementation attenuated the pro-inflammatory effects, but did not completely reverse the features of allergic airway inflammation. CONCLUSION AND CLINICAL RELEVANCE: Vitamin D could be beneficial as an adjunct therapy in the treatment of allergic asthma.

Oxidized Low-density Lipoproteins and Lipopolysaccharides Augment Carotid Artery Plaque Vulnerability in Hypercholesterolemic Microswine.

Atherosclerosis is a chronic inflammatory disease and hypercholesterolemia is a risk factor. This study aims to compare the potency of lipopolysaccharide (LPS) and oxidized low-density lipoproteins (oxLDL) to induce plaque formation and increase plaque vulnerability in the carotid artery of hypercholesterolemic Yucatan microswine. Atherosclerotic lesions at the common carotid artery junction and ascending pharyngeal artery were induced in hypercholesterolemic Yucatan microswine at 5-6 months of age with balloon angioplasty. LPS or oxLDL were administered intraluminally at the site of injury after occluding the arterial flow temporarily. Pre-intervention ultrasound (US), angiography, and optical coherence tomography (OCT) were done at baseline and just before euthanasia to assess post-op parameters. The images from the US, OCT, and angiography in the LPS and the oxLDL-treated group showed increased plaque formation with features suggestive of unstable plaque, including necrotic core, thin fibrous caps, and a signal poor region more with oxLDL compared to LPS. Histomorphology of the carotid artery tissue near the injury corroborated the presence of severe lesions in both LPS and oxLDL-treated pigs but more in the oxLDL group. Vascular smooth muscle and endothelial cells treated with LPS and oxLDL showed increased folds changes in mRNA transcripts of the biomarkers of inflammation and plaque vulnerability compared to untreated cells. Collectively, the results suggest that angioplasty-mediated intimal injury of the carotid arteries in atherosclerotic swine with local administration of LPS or ox-LDL induces vulnerable plaques compared to angioplasty alone and oxLDL is relatively more potent than LPS in inducing vulnerable plaque.

Interaction of suplatast tosilate (IPD) with chloride channels in human blood eosinophils: a potential mechanism underlying its anti-allergic and anti-asthmatic effects.

INTRODUCTION: Alterations in chloride ion channels have been implicated in the induction of changes in cell shape and volume. Because blood and tissue eosinophilia are hallmarks of bronchial asthma, in this study we examined the role of chloride channels in the underlying effects of suplatast tosilate (IPD), an anti-allergic drug, in human blood eosinophils. METHODS: Eosinophils were isolated and purified from the blood of allergic asthmatic donors. Chloride ion currents were recorded using the whole-cell patch-clamp technique in freshly isolated eosinophils. The current-voltage relationship of whole-cell currents in human blood eosinophils was calculated and recorded. The effect of chloride channel blockers was examined on superoxide release, eosinophil chemotaxis as measured by the Boyden chamber, and eosinophil adhesion to endothelial cells. Radioligand binding studies with [3H]IPD and competition curves with chloride channel blockers were performed. RESULTS: IPD increased both inward and outward chloride currents in human blood eosinophils. IPD in 1 ng/mL did not have significant effect on chloride current. However, at 5 ng/mL IPD activated both outward and inward currents in human blood eosinophils. Chloride channel blockers inhibited IPD-induced respiratory burst in eosinophils, eosinophil chemotaxis, and eosinophil adhesion to endothelial cells. All these effects of IPD on chloride current and the resultant functional responses in human blood eosinophils were not due to its basic salt, p-toluenesulphonic acid monohydrate. Human blood eosinophils contained specific binding sites for [3H]IPD with K(D) and B(max) values of 187.7+/-105.8 nm and 58.7+/-18.7 fmol/10(6) cells, respectively. Both NPPB and DIDS competed, in a dose-dependent manner, for the specific binding of [3H]IPD in human blood eosinophils. CONCLUSION: These data suggest that the anti-allergic and anti-asthmatic effects of IPD could be due to its interaction with chloride channels in human blood eosinophils.

Traumatic pulmonary pseudocyst: An underreported entity.

BACKGROUND: Traumatic pulmonary pseudocysts (TPP) are underreported cavitary lesions of the pulmonary parenchyma that can develop following blunt chest trauma. Although the occurrence of traumatic pulmonary pseudocyst is rare, this condition should be considered in the differential diagnosis of any cavitary lesion. Awareness of this injury and its clinical significance is important for successful management in order to avoid medical errors in the course of treatment. METHODS: A literature search was conducted through Medline using the key phrases "traumatic pulmonary pseudocyst" and "traumatic pneumatocele." Relevant articles, especially those with focus on diagnosis and management of traumatic pneumatocele in adults, were selected. Due to the scarcity of literature and lack of Level I evidence on this subject, studies published in any year were considered. RESULTS: A search of "traumatic pulmonary pseudocyst" and "traumatic pneumatocele" yielded 114 studies. Most of these were excluded based on inclusion and exclusion criteria. Thirty-five articles were reviewed. The majority of these were individual case studies; only eight articles were considered large case studies (greater than eight patients). CONCLUSION: Traumatic pulmonary pseudocysts are lesions that occur secondary to blunt chest trauma. Diagnosis is based on a history of trauma and appearance of a cystic lesion on CT. Accurate diagnosis of traumatic pulmonary pseudocyst is imperative to achieve successful outcomes. Failure to do so may lead to unnecessary procedures and complications.

In stent restenosis: bane of the stent era.

The long term outcome of stent implantation is affected by a process called in stent restenosis (ISR). Multiple contributory factors have been identified, but clear understanding of the overall underlying mechanism remains an enigma. ISR progresses through several different phases and involves numerous cellular and molecular constituents. Platelets and macrophages play a central role via vascular smooth muscle cell migration and proliferation in the intima to produce neointimal hyperplasia, which is pathognomic of ISR. Increased extracellular matrix formation appears to form the bulk of the neointimal hyperplasia tissue. Emerging evidence of the role of inflammatory cytokines and suppressors of cytokine signalling make this an exciting and novel field of antirestenosis research. Activation of Akt pathway triggered by mechanical stretch may also be a contributory factor to ISR formation. Prevention of ISR appears to be a multipronged attack as no therapeutic "magic bullet" exists to block all the processes in one go.

A comparison of stent-induced stenosis in coronary and peripheral arteries.

BACKGROUND AND OBJECTIVES: Restenosis is a complication of interventional procedures such as angioplasty and stenting, often limiting the success of these procedures. Knowledge regarding the relative behaviour of different arteries after these procedures is limited, despite the extensive use of different vascular models. Although the results from studies using different vessels are analysed to predict the behaviour of coronary arteries and other vasculature, direct controlled comparisons between different arteries are necessary for a better understanding of the differential response to restenosis. METHODS: This study examines the response to stenting in coronary and internal iliac arteries as characterised by intimal hyperplasia and restenosis. In a swine model of in-stent stenosis, coronary arteries exhibited higher levels of intimal hyperplasia and per cent stenosis than internal iliac arteries. RESULTS: After normalisation for injury score, coronary arteries were found to undergo 47% more intimal hyperplasia (p<0.05), whereas per cent stenosis normalised for injury score tended to be higher (p = 0.01). Other measurements reflecting post-stenting intimal hyperplasia (maximal intimal thickness, medial area) did not exhibit significant differences between the artery groups. CONCLUSIONS: These results show that coronary vessels are more prone to develop significant intimal hyperplasia and subsequent restenosis than internal iliac vessels. A better insight into how different arteries and arterial components behave is important in understanding and developing newer and better therapeutic measures for restenosis.

Numerical Verification of an Analytical Model for Phase Noise in MEMS Oscillators.

A new analytical formulation for phase noise in MEMS oscillators was recently presented encompassing the role of essential nonlinearities in the electrical and mechanical domains. In this paper, we validate the effectiveness of the proposed analytical formulation with respect to the unified theory developed by Demir et al. describing phase noise in oscillators. In particular, it is shown that, over a range of the second-order mechanical nonlinear stiffness of the MEMS resonator, both models exhibit an excellent match in the phase diffusion coefficient calculation for a square-wave MEMS oscillator.

Bismuth Titanate Fabricated by Spray-on Deposition and Microwave Sintering For High-Temperature Ultrasonic Transducers.

Thick films of ferroelectric bismuth titanate (Bi4Ti3O12) have been fabricated by spray-on deposition in conjunction with microwave sintering for use as high-temperature ultrasonic transducers. The elastic modulus, density, permittivity, and conductivity of the films were characterized. Electro-mechanical properties of the films were estimated with a commercial d33 meter which gave 16 pC/N. This value is higher than typically reported for bulk bismuth titanate; however, these films withstand higher field strengths during poling which is correlated with higher d33 values. Films were capable of operating at 650 °C for roughly 5 min before depoling and can operate at 600 °C for at least 7 days.

Characterization of autoantibodies to vasoactive intestinal peptide in asthma.

Vasoactive intestinal peptide (VIP) is a potent relaxant of the airway smooth muscle. In this study, VIP-binding autoantibodies were observed in the plasma of 18% asthma patients and 16% healthy subjects. Immunoprecipitation studies and chromatography on DEAE-cellulose and immobilized protein G indicated that the plasma VIP-binding activity was largely due to IgG antibodies. Saturation analysis of VIP binding by the plasmas suggested the presence of one or two classes of autoantibodies, distinguished by their apparent equilibrium affinity constants (Ka). The autoantibodies from asthma patients exhibited a larger VIP-binding affinity compared to those from healthy subjects (Ka 7.8 x 10(9) M-1 and 0.13 x 10(9) M-1, respectively; P less than 0.005). The antibodies were specific for VIP, judged by their poor reaction with peptides bearing partial sequence homology with VIP (peptide histidine isoleucine, growth hormone releasing factor and secretin). IgG prepared from the plasma of an antibody-positive asthma patient inhibited the saturable binding of 125I-VIP by receptors in guinea pig lung membranes (by 39-59%; P less than 0.001). These observations are consistent with a role for the VIP autoantibodies in the airway hyperresponsiveness of asthma.

Functional and morphological assessment of rat aorta stored in University of Wisconsin and Eurocollins solutions.

University of Wisconsin (UW) and Eurocollins (EC) solutions are widely used for preservation of organs before transplantation. However, effect of storage solutions on vascular interface for transplant success is not known. In this study, we have used rat aorta as a model and assessed the effects of cold storage in UW and EC solutions on smooth muscle and endothelial function and the morphology. Smooth muscle and endothelial functions of the rat aorta were assessed using in vitro isometric tension measurement. Morphologic studies were done with scanning and transmission electron microscopy. No significant difference in contractile response to either norepinephrine (NE) or potassium chloride was observed between control aorta and aorta stored in UW solution for 1 hr or 24 hr. In contrast, sensitivity, but not the reactivity to NE and KCl, was increased in aorta stored in EC solution for 1 hr. If the tissues were stored in EC solution for 24 hr, both sensitivity and reactivity to NE and KCl were significantly reduced. Relaxatory response to acetylcholine, in endothelium-intact vessels were reduced in aortas stored in EC solution, but not in UW solution. The magnitude of relaxations observed in tissues stored in the EC solution for 24 hr was less than in tissues stored for 1 hr. Sodium nitroprusside elicited similar relaxatory response in endothelium-denuded control tissue and in tissues stored in UW and EC solution. Electron microscopy data revealed marked swelling of the cell, loss of mitochondria and other intracellular organelles, and striking calcium deposits after preservation of the vessels in EC for 1 or 24 hr. In aorta stored in UW solution for 24 hr, endothelial and smooth muscle cells were intact, with moderate-size vacuoles in the cytoplasm. These results suggest that the UW solution is more suitable than EC solution for short-term preoperative storage of blood vessels.

Pharmacology and clinical efficacy of desloratadine as an anti-allergic and anti-inflammatory drug.

Desloratadine is a biologically active metabolite of the second-generation antihistamine loratadine. Desloratadine is a highly selective peripheral H1 receptor antagonist that is significantly more potent than loratadine. Results of in vitro and in vivo studies have suggested that desloratadine has anti-allergic effects that are unrelated to its ability to antagonise the effects of histamine. Desloratadine inhibits the expression of cell adhesion molecules, inhibits the generation and release of inflammatory mediators and cytokines, attenuates eosinophil chemotaxis, adhesion and superoxide generation. Studies in animals indicate that desloratadine does not cross the blood-brain barrier and therefore does not cause sedation and does not impair cognition or psychomotor performance. Desloratadine has an excellent overall safety profile. It has no effect on QRS and QTc intervals and does not cause arrhythmias. Desloratadine is not associated with any significant changes in gastrointestinal function. In clinical studies, oral desloratadine is rapidly absorbed and bioavailability is not affected by ingestion with food or grapefruit juice. The half-life of desloratadine in humans is 27 h; the linear kinetic profile is unaltered by race or gender. Desloratadine is not a substrate for P-glycoprotein or organic anion transport polypeptide and the drug does not appear to be metabolised to a significant extent by the cytochrome P450 CYP3A4 pathway. It therefore may be safely administered with ketoconazole, erythromycin, fluoxetine, or azithromycin. Clinically, desloratadine effectively controls both nasal and non-nasal symptoms of seasonal allergic rhinitis (SAR), including nasal congestion. Desloratadine also provides significant relief of SAR symptoms in patients with co-existing asthma and is effective in the treatment of chronic idiopathic urticaria. Desloratadine improves quality of life and is well-tolerated.

Terfenadine effect on the bronchoconstriction, dermal response, and leukopenia induced by platelet-activating factor.

We have investigated the protective effect of oral terfenadine, a H1 antagonist, on the dermal and pulmonary response, and changes of circulating WBCs to injected and inhaled platelet activating factor. Nine men with mild asthma participated in a double-blind, crossover study using terfenadine, 120 mg, or placebo. Three hours after administration of study drug, pulmonary function was measured, and a PAF challenge was performed. Skin test to histamine and PAF was performed prior to study drug, and 2.5 hours after drug. Circulating WBC count was determined prior to PAF inhalation and during the PAF challenge. There was a significant improvement in pulmonary function on terfenadine. Terfenadine significantly inhibited the wheal and flare response to histamine and the flare response to injected PAF. Terfenadine did not have an effect on the change in circulating WBC count or the change in pulmonary function to inhaled PAF. These results suggest a limited role for endogenous histamine for the effects of PAF.

Effect of platelet-activating factor inhalation on nonspecific bronchial reactivity in man.

Bronchial hyperactivity is a recognized hallmark of asthma, characterized by an exaggerated bronchial response to numerous mediators, including histamine. It is also well recognized that bronchial hyperresponsiveness is increased following allergen exposure, although no particular mediator has been shown to induce this response. The recent observation that PAF can induce increased nonspecific bronchial reactivity in normal subjects emphasizes its importance as an inflammatory mediator. In this report we sought to further elucidate the role of PAF in airway hyperreactivity by comparing the effect of PAF on methacholine-induced airway responsiveness in six non-asthmatic subjects. Nonspecific airway responsiveness was not significantly increased following PAF inhalation at 6 hours nor was it increased at 1, 2, 7, or 14 days. Further elucidation of the potential role of PAF in explaining changes in airway reactivity is necessary.

Effect of PAF-acether inhalation on nonspecific bronchial reactivity and adrenergic response in normal and asthmatic subjects.

Bronchial hyperreactivity, although recognized as a hallmark of asthma, is not totally understood. Mast cell-derived mediators, including histamine, have been shown to cause immediate bronchoconstriction, but until recently, no single mediator has been shown to induce prolonged changes in airway reactivity. Recent reports indicate PAF-acether (PAF) can induce increased nonspecific bronchial reactivity in normal subjects but not in asthmatics. We sought to elucidate the role of PAF in airway hyperreactivity by comparing the effect of inhaled PAF on methacholine and isoproterenol airway responsiveness in six nonasthmatic and six asthmatic subjects. Neither nonspecific airway reactivity nor isoproterenol responsiveness was changed following PAF inhalation in the nonasthmatic subjects in the six days following PAF. Asthmatics had increased airway responsiveness to methacholine at two hours post-PAF, which did not persist. Responsiveness to isoproterenol did not change in the asthmatic subjects. Additional evaluation of the role of PAF in causing changes in airway reactivity is warranted.

Target size of 5'-nucleotidase in smooth muscle.

Target size of the 5'-nucleotidase in six different smooth muscles was determined by radiation inactivation. The enzyme in the soluble fraction of rat myometrium and vas deferens gave a target size of approximately 80,000 daltons. The plasma membrane bound 5'-nucleotidase however, gave target size of 80,000 to 110,000 daltons in rat gastric fundus and vas deferens and dog stomach and ileum, 135,000 daltons in rat mesenteric artery and 210,000 daltons in rat myometrium.

Multiple arterial injuries and prolonged cholesterol feeding do not increase percent lumen stenosis: impact of compensatory enlargement in the microswine model.

While the swine model is frequently utilized in the study of arterial intervention, it has been difficult to create severe peripheral arterial stenosis without total thrombotic occlusion with a single arterial injury and short-term cholesterol feeding. The combination of multiple arterial injuries and prolonged cholesterol feeding was explored in an effort to create lesions with significant luminal compromise. Nineteen microswine were divided into two groups and fed a high cholesterol diet followed by multiple balloon injuries of the iliac arteries. We conclude that repeated balloon injuries and longer cholesterol feeding significantly increase areas of plaque and necrotic core but do not increase percent stenosis because of arterial compensatory enlargement. The microswine iliac arteries enlarge in relation to plaque area and repeated balloon injuries. The compensatory lumen enlargement may be one of the factors resulting in significant angiographic underestimation of plaque area during the early stage of the atherosclerotic disease, but it may functionally delay important lumen stenosis until the lesion occupies 40% of the internal elastic lamina area. This study suggests that repeated injury and longer cholesterol feeding to increase percent stenosis may not be cost effective in this model. However, this model is good for studying an increase in plaque accumulation.

Short-term preservation of autogenous vein grafts: effectiveness of University of Wisconsin solution.

BACKGROUND: Suboptimal preservation of autologous veins in storage solutions causes endothelial cell damage that can contribute to graft failure. The purpose of this study was to compare the effects of short-term storage of veins in autologous whole blood (AWB), 0.9% normal saline solution (NS), and University of Wisconsin solution (UWs) on vein structure and function after grafting. METHODS: Autogenous jugular and femoral veins were atraumatically harvested from mongrel dogs. One vein segment was immediately implanted to serve as a control, and the other segments were stored for 45 minutes in AWB, NS, or UWs. The veins were implanted as reversed interposition graft in the carotid or femoral arteries. After 6 weeks light and scanning electron microscopy and isometric tension studies were performed on explanted vein grafts. RESULTS: Morphologic studies revealed an intact endothelium that stained positively for factor VIII. Intimal thickness was similar between controls (48 +/- 12 microns) and veins stored in UWs (53 +/- 8 microns) (p = not significant), but it was significantly increased in veins stored in AWB (151 +/- 29 microns) and NS (149 +/- 18 microns) (p < 0.05). Sensitivity and maximum contraction to norepinephrine were not altered in veins preserved in UWs (6.0 +/- 0.1 mumol/L and 0.19 +/- 0.02 gm/mm2) but were significantly reduced (p < 0.05) in those stored in AWB (7.2 +/- 0.1 mumol/L and 0.08 +/- 0.02 gm/mm2) and NS (7.0 +/- 0.3 mumol/L and 0.09 +/- 0.02 gm/mm2) compared with controls (5.9 +/- 0.2 mumol/L and 0.20 +/- 0.02 gm/mm2). The sensitivity and maximum relaxation to acetylcholine and sodium nitroprusside of veins preserved in AWB, NS, and UWs were similar to controls (p = not significant). CONCLUSIONS: Vein storage in UWs preserves smooth muscle cell function compared with veins stored in NS or AWB. Therefore UWs is a more suitable medium for short-term preservation of veins in cardiovascular operation.

Modification of eosinophil function by suplatast tosilate (IPD), a novel anti-allergic drug.

Suplatast tosilate (IPD), a new dimethylsulfonium agent, is used therapeutically in allergic diseases. Suplatast has been reported to attenuate airway hyperresponsiveness in guinea pigs, human IgE synthesis, and murine peritoneal eosinophilia. However, the effect of suplatast on human eosinophils is not known. In this study, we examined the effects of suplatast in human eosinophils on platelet activating factor (PAF, 1 microM)-induced chemotaxis by the blind well chamber technique, eosinophil adhesion to TNF-alpha (10 ng/ml) or IL-4 (10 ng/ml)-stimulated human umbilical vein endothelial cells (HUVECs), and expression of very late antigen-4 (VLA-4) on eosinophils and vascular cell adhesion molecule-1 (VCAM-1) on HUVECs by flow cytometry. Suplatast suppressed IL-4-induced eosinophil adhesion to HUVECs in a dose-dependent manner. Eosinophils from the normal subjects did not express VLA-4. However, there was a significant increase (P < 0.01) in the basal expression of VLA-4 in allergic patients. PAF or IL-4 did not enhance VLA-4 expression on eosinophils, and there was no significant effect of suplatast on VLA-4 expression in allergic patients. Suplatast did not affect TNF-alpha-induced VCAM-1 expression. Interestingly, suplatast significantly suppressed IL-4 induced VCAM-1 expression on HUVECs and PAF-induced eosinophil chemotaxis. These data suggest that suplatast may modify eosinophil participation in airway inflammation by attenuating inflammatory mediators-induced chemotaxis and adhesion to endothelial cells, and thus might be useful in the treatment of bronchial asthma.

Flt3 ligand: a novel cytokine prevents allergic asthma in a mouse model.

Flt-3 ligand (FL), a recently described growth factor affecting early hematopoietic progenitor cells, can also support the expansion of dendritic cells secreting IL-12. Since type 2 T cells predominate in asthma and IL-12 prevents the differentiation of naive T lymphocytes to a type 2 phenotype, we hypothesized that FL could prevent the development of asthma-like conditions in the ovalbumin mouse model. We found that co-administration of FL during ovalbumin sensitization abrogated late allergic responses, but had no effect on early allergic responses. Airway hyperresponsiveness to methacholine was also blocked by FL treatment. Analysis of bronchoalveolar lavage (BAL) fluid demonstrated a significant reduction in eosinophils, with concomitant decreases in IL-5 and increases in IFN-gamma levels. However, there was no change in BAL fluid IL-4 and serum IgE levels. These data suggest that FL treatment prevents ovalbumin-induced asthma in the mouse and may provide a useful adjuvant in the treatment of human asthma.