In situ validation of VEGFR-2 and <Emphasis Type="Italic">α</Emphasis><Subscript><Emphasis Type="Italic">v</Emphasis></Subscript><Emphasis Type="Italic">ß</Emphasis><Subscript>3</Subscript> integrin as targets for breast lesion characterization

Vascular endothelial growth factor receptor 2 (VEGFR-2) and α _v ß ₃ integrin are the most frequently addressed targets in molecular imaging of tumor angiogenesis. In preclinical studies, molecular imaging of angiogenesis has shown potential to detect and differentiate benign and malignant lesions of the breast. Thus, in this retrospective clinical study employing patient tissues, the diagnostic value of VEGFR-2, α _v ß ₃ integrin and vascular area fraction for the diagnosis and differentiation of breast neoplasia was evaluated. To this end, tissue sections of breast cancer (n = 40), pre-invasive ductal carcinoma in situ (DCIS; n = 8), fibroadenoma (n = 40), radial scar (n = 6) and normal breast tissue (n = 40) were used to quantify (1) endothelial VEGFR-2, (2) endothelial α _v ß ₃ integrin and (3) total α _v ß ₃ integrin expression, as well as (4) the vascular area fraction. Sensitivity and specificity to differentiate benign from malignant lesions were calculated for each marker by receiver operating characteristics (ROC) analyses. Whereas vessel density, as commonly used, did not significantly differ between benign and malignant lesions (AUROC: 0.54), VEGFR-2 and α _v ß ₃ integrin levels were gradually up-regulated in carcinoma versus fibroadenoma versus healthy tissue. The highest diagnostic accuracy for differentiating carcinoma from fibroadenoma was found for total α _v ß ₃ integrin expression (AUROC: 0.76), followed by VEGFR-2 (AUROC: 0.71) and endothelial α _v ß ₃ integrin expression (AUROC: 0.68). In conclusion, total α _v ß ₃ integrin expression is the best discriminator between breast cancer, fibroadenoma and normal breast tissue. With respect to vascular targeting and molecular imaging of angiogenesis, endothelial VEGFR-2 appeared to be slightly superior to endothelial α _v ß ₃ for differentiating benign from cancerous lesions.     

Val/Leu<Superscript>247</Superscript> and Trp/Ser<Superscript>316</Superscript> polymorphisms in β<Subscript>2</Subscript> glycoprotein I and their association with thrombosis in unselected Chilean patients

It is known that polymorphisms of β ₂-glycoprotein I (β ₂GPI) in exon 7 affect interaction between the phospholipid binding site and the antibodies, and that other polymorphisms in exon 8 increase the generation of antibodies. In this study, we analyzed genetic polymorphisms of β ₂GPI in unselected Chilean patients to determine the prevalence of β ₂GPI polymorphisms in the phospholipid domain in patients with venous and arterial thrombosis and the clinical correlation with thromboembolic complications. This study comprised 149 patients with venous and arterial thrombosis (62 with venous thrombosis and 87 with arterial thrombosis) and 160 healthy controls with no previous history of thrombosis. Polymorphisms of exons 7 and 8 of β ₂GPI, which encode for its fifth domain, were determined by PCR-RFLP. The presence of aPL or anti-β ₂GPI in the patients was detected by ELISA. Anti-β ₂GPI were present in 8/149 patients (5.4%); of these, five had aCL antibodies of low titer. The allele containing Val/Leu²⁴⁷ and Trp/Ser³¹⁶ was significantly more frequent in patients with thrombosis than in the control group (OR=3.1, CI 1.6–6.0, p=0.0003; OR=2.9, CI 1.1–8.6, p=0.027, respectively). These polymorphisms did not correlate with aPL or anti-β ₂GPI but significant differences were observed with venous thrombosis (p=<0.0001) and arterial thrombosis (p=0.026). In conclusion, the β ₂GPI polymorphisms Val/Leu²⁴⁷ and Trp/Ser³¹⁶ are not related to the presence of anti-β ₂GPI antibodies in unselected Chilean patients with venous and arterial thrombosis, but they are significantly associated with venous and arterial thrombosis.     

α<Subscript>1</Subscript>-Antitrypsinmangel

α₁-antitrypsin deficiency is characterized by a pathologic reduction of the serum concentration of α₁-antitrypsin, the most important antiprotease in man. It is one of the most common hereditary diseases in Caucasians. Approximately 2% of obstructive airway diseases are caused by α₁-antitrypsin deficiency. Patients above 35 years may develop lung emphysema, especially in the lower lobes. Symptoms are those of chronic obstructive pulmonary disease such as cough, sputum expectoration, and progressive dyspnoea. Patients with homozygous defect often develop cholestatic hepatitis in the neonatal period. However, only few adult patients develop chronic liver disease up to liver cirrhosis with an elevated risk for malignant liver tumors. The diagnostic hallmark is the reduced serum concentration of α₁-antitrypsin while genetic testing proves the defect. An early recognition of the disease is decisive for prophylactic and therapeutic measures. Smoking should be stopped immediately. Treatment of lung disease includes physiotherapy, antiobstructive and antiinflammatory medication, augmentation with human α₁-antitrypsin and lung surgery including lung transplantation. Liver toxins should be avoided. Besides experimental therapeutic approaches, liver disease can only be treated by liver transplantation.     

HERG K<Superscript>+</Superscript> channel expression in CD34<Superscript>+</Superscript>/CD38<Superscript>−</Superscript>/CD123<Superscript>high</Superscript> cells and primary leukemia cells and analysis of its regulation in leukemia cells

The human ether-a-go-go-related (herg) gene encoding K⁺ channels (HERG) belongs to an evolutionarily conserved multigene family of voltage activated K⁺ channels. The functional properties of HERG K⁺ channels are complex and their contribution to the repolarization of the cardiac action potential are well understood. Recent studies revealed that HERG K⁺ channels are preferentially expressed in different histogenesis of tumor cells. Leukemia is a cancer that originates in the bone marrow hematopoietic stem cells (HSCs). Leukemia stem cells (LSCs) are critical in the perpetuation of the disease. A better understanding of LSCs and molecular biology will allow the design of more effective therapies. We report in this study that herg was expressed in CD34⁺/CD38⁻/CD123^high LSCs but not expressed in normal bone marrow CD34⁺/CD38⁻ HSCs. In addtion, herg is also expressed in leukemia cell lines K562 and HL-60 and almost all the primary leukemia cells whereas not in the normal bone marrow cells. In addition, the expression of herg mRNA was not associated with the clinical and cytogenetic feature of leukemia. Moreover, HERG K⁺ channels can regulate leukemia cells proliferation and cell cycle. These data provide evidence for the oncogenic potential of HERG K⁺ channels and it may be a novel, potential pharmacological target for leukemia therapy in the future.     

HbE Level and Red Cell Parameters in Heterozygous HbE With and Without α<Superscript>0</Superscript>-Thalassemia Trait

We compared hemoglobin (Hb) E levels and red cell parameters between heterozygous HbE with and without α⁰-thalassemia trait and also determine their appropriated cut-off points for differentiating these two groups. High performance liquid chromatography analysis results and mean levels of red blood cell (RBC) parameters, including RBC count, total Hb, hematocrit, MCV, MCH and MCHC of heterozygous HbE with α⁰-thalassemia trait (n?=?183) and without α⁰-thalassemia trait (n?=?1437) were reviewed and compared. The α⁰-thalassemia status in these samples was detected by real-time PCR with SYBR Green1 and high resolution melting analysis. Mean levels of HbE, total Hb, MCV, MCH and MCHC of heterozygous HbE with α⁰-thalassemia trait were significantly lower than those of heterozygous HbE without α⁰-thalassemia trait (P?<?0.001). In addition, HbE level at a cut-off value of?<?24% was superior to MCV (<?80 fL) and MCH (<?27 pg) for differentiating the heterozygous HbE with and without α⁰-thalassemia trait with 100% sensitivity and 87.2% specificity. Despite certain limitations of this study like missing RDW and reticulocyte counts, and not testing for α⁺-thalassemia and Hb Constant Spring, we conclude that the HbE level at a cut-off point of?<?24% is a useful marker for initial discrimination between heterozygous HbE with and without α⁰-thalassemia trait.     

Inhaled Glucocorticosteroid and Long-Acting β<Subscript>2</Subscript>-Adrenoceptor Agonist Single-Inhaler Combination for Both Maintenance and Rescue Therapy

Despite aggressive fixed-dose (FD) combination therapy with inhaled glucocorticosteroids (ICS) and long acting beta(2)-adrenoceptor agonists (LABA), many patients with asthma remain suboptimally controlled, based on the need for rescue therapy and rates of severe exacerbations. The strategy of adjustable maintenance dosing (AMD) involves adjustment of the maintenance dose, (using a single combination [budesonide/formoterol] inhaler, Symbicort((R))) in response to variability of asthma control over time. The AMD strategy, like the FD approach, involves the use of a short-acting beta(2)-adrenoceptor agonist (SABA) for rapid relief of bronchospasm. The dose-response characteristics of budesonide/formoterol make the AMD strategy a feasible option that cannot be exploited with the combination of salmeterol/fluticasone propionate (Advair((R))). Several studies suggest that the AMD strategy is superior to a FD approach in terms of overall asthma control.Budesonide/formoterol in a single inhaler is as effective as albuterol (salbutamol) for relief of acute asthma episodes, a feature that makes it possible to use this combination for both maintenance and reliever therapy without the need for the use of a SABA. The single-inhaler strategy has been shown to be safe and more efficacious than FD therapy. In particular, the COSMOS study has demonstrated that exacerbation burden is reduced more effectively when the combination (budesonide/formoterol) single inhaler is used for both maintenance and relief compared with FD therapy with salmeterol/fluticasone and albuterol for rescue in patients with moderate-to-severe asthma. These findings suggest that we will have to reconsider our definition of reliever therapy for patients that require long-term therapy with combination ICS and LABA.The concept of single-inhaler therapy represents a paradigm shift in asthma management that has been validated in several large studies involving thousands of patients. The single-inhaler strategy represents one of the most significant advances in asthma management in many years, and one that appears ideal for adoption in primary care.     

Heterophilic interactions between cell adhesion molecule L1 and α<Subscript>v</Subscript> β<Subscript>3</Subscript>-integrin induce HUVEC process extension <Emphasis Type="Italic">in vitro</Emphasis> and angiogenesis <Emphasis Type="Italic">in vivo</Emphasis>

Cell adhesion molecule L1 was implicated in angiogenic processes, tumor formation and metastasis. Here, we provide evidence that the sixth Ig-like domain of L1 (L1Ig6) interacts with _{v 3} to induce process extension of human umbilical vein endothelial cells (HUVECs) in vitro and angiogenesis in vivo. HUVECs formed network-like structures on full-length L1 or L1Ig6 substrates comparable to structures found on matrigel. In the presence of mab _{v 3} or cyclic RGD, apoptosis was induced. In fibrin matrices where L1Ig6 was covalently incorporated, HUVECs formed multicellular and hollow processes through interactions between cell-surface _{v 3} and RGD-sites of matrix-immobilized L1Ig6. No such processes were induced by L1Ig6 having non-functional RDG-sites, or in the presence of mab _{v 3} or cyclic RGD. In those matrices, increased apoptosis was found. Co-immunoprecipitation of L1 or L1Ig6 with _{v 3} suggests close interactions. Furthermore, L1Ig6 stimulated HUVECs showed increased tyrosine phosphorylation of _{v 3} and phosphorylation of MAP kinases (ERK1 and ERK2) but not AKT indicating specific activation of _v and _{v 3} followed by activation of downstream kinases. Application of L1Ig6-modified fibrin matrices on CAMs induced 50–60% increased _v and _v3 protein expression and in vivo angiogenesis indicated by ~50% increased mean vascular length density. The results demonstrate angiogenic potential of L1Ig6 involving ligation and activation of _v3     

β<Subscript>2</Subscript>-Agonist Eutomers

β₂-adrenoceptor agonists (β₂-agonists) such as albuterol (salbutamol) and terbutaline and their long-acting analogs salmeterol and formoterol are widely used as bronchodilators in the treatment of asthma. They are chiral drugs historically marketed as racemic mixtures of an active (eutomer) and essentially inactive (distomer) stereoisomer. Despite their obvious therapeutic value and widespread use, β₂-agonists have been implicated, somewhat controversially, in causing an increase in asthma mortality and a deterioration of asthma control by a mechanism that remains elusive. Inherent toxicity of the distomers has been widely touted as an explanation and has given rise to pressure for the replacement of the racemates with pure eutomer formulations (the so-called chiral or racemic switch). This has culminated in the recent introduction into clinical practice of the single active stereoisomer of albuterol (levalbuterol) and the promise of other pure β₂-agonist eutomer formulations to follow. This article examines the evidence on which these chiral switches are based.Clinical studies designed to reveal negative effects of β₂-agonists have searched for reductions in lung function, increases in airway responsiveness to bronchoconstrictor mediators and worsening of asthma control. Crossover studies administering the pure stereoisomers and racemate of albuterol have not shown a clear superiority of the pure eutomer formulation over the racemate in terms of either bronchial hyperresponsiveness, tachyphylaxis to bronchoprotective effects or improvements in lung function. Clinical toxicity of β₂-agonist distomers on any aspect of asthmatic lung function has also not been demonstrated in the relatively short-term inhalational studies (single dose or repeated dose studies <1 week) that have been carried out.In animal studies, the administration of β₂-agonist racemates and distomers has been shown to enhance bronchial hyperresponsiveness but only in ovalbumin-sensitized animals where the relevance to humans is questionable.The pharmacokinetics and metabolism of β₂-agonist stereoisomers appear to be essentially similar whether administered as single stereoisomers or as racemates. Levalbuterol may be slightly more potent than an equivalent dose given as racemate, but there is some evidence that it forms a small amount of the distomer in vivo which detracts somewhat from its purported benefits over use of the racemate.Whilst there remains a clear need for studies of longer duration with sensitive clinical endpoints to evaluate the benefits of β₂-agonist eutomers and to investigate distomer toxicity, the chiral switch for β₂-agonists in general, and for albuterol in particular, does not appear to be justified on the basis of the evidence available to date.     

Long-Acting β<Subscript>2</Subscript>-Agonists

Salmeterol and formoterol are both long-acting β₂-adrenoceptor agonists (β₂-agonists). They both provide excellent bronchodilating and bronchoprotective effects in patients with asthma but their are some differences between these two long-acting β₂-agonists in vitro and in vivo. Formoterol has a greater potency and intrinsic activity than salmeterol, which can become especially apparent at higher doses than that clinically recommended, and in contracted bronchi. Long-term use of long-acting β₂-agonists can induce tolerance, which can be partially reversed with corticosteroids. Long-acting β₂-agonists have some anti-inflammatory effects in vitro, but data in vivo are less convincing. Compared with doubling the dose of inhaled corticosteroids, the addition of inhaled long-acting β₂-agonists to inhaled corticosteroids improves symptom control in patients with asthma and reduces both the exacerbation rate of asthma and hospital admission rate. No enhanced airway responsiveness or loss of perception of dyspnea has been observed with the use of inhaled long-acting β₂-agonists. Monotherapy with long-acting β₂-agonists is not recommended.     

IgG antibodies to plasminogen and their relationship to IgG anti-β<Subscript>2</Subscript>-glycoprotein 1 antibodies and thrombosis

Reduced fibrinolytic activity has been described in primary antiphospholipid syndrome (PAPS) and may be responsible for thrombotic events. Some evidence supports a relationship between anti-plasminogen (PLG) antibodies, anti-β₂-glycoprotein 1 (β₂GP1) antibodies, and fibrinolysis, but their relationship is still unclear. The aim of study is to evaluate the association between IgG anti-β₂GP1 and IgG anti-PLG antibodies and thrombosis. Two groups of consecutive patients with PAPS and systemic lupus erythematosus (SLE): 32 patients with lupus anticoagulant (LAC), 32 patients without LAC, and 40 healthy controls were included. IgG against β₂GP1 and PLG antibodies were measured by enzyme-linked immunosorbent assay, and a value above the 99th percentile of the normal healthy control was considered as positive, and their interrelationship with thrombosis was evaluated by Pearson Chi-squared test. Cross-reactive antibodies binding to PLG and β₂GP1 were determined in a competitive and cross-inhibition assay. Levels of fibrinolytic activity in the presence of IgG fractions from patients and healthy controls were examined using a plasmin fluorogenic substrate assay. A high frequency of IgG anti-PLG antibodies (35.9%) was found in 64 patients, and its presence was associated with thrombosis (p = 0.001), which may be due to its ability to inhibit exogenous fibrinolysis. Coexistence of IgG anti-PLG and IgG anti-β₂GP1 antibodies was found in 11 of 64 patients and was related with thrombosis (p = 0.001). Cross-reactive antibody binding to PLG and β₂GP1 was found in IgG fractions from three patients and a monoclonal anti-β₂GP1 antibody BD4, and one of these three patients had thrombotic history. However, no significant association was found between IgG anti-PLG and IgG anti-β₂GP1 antibodies in patients. In conclusion, the prevalence of IgG anti-PLG was high in patients with PAPS and SLE and might relate with thrombosis. Cross-reactivity of IgG anti-β₂GP1 antibodies with PLG may occur in the sera of patients.     

Prevalence of Anticardiolipin and Anti-β<Subscript>2</Subscript>-Glycoprotein I Antibodies in Celiac Disease

The aim of this study was to evaluate the prevalence of anticardiolipin antibodies (aCL) and anti-β₂-glycoprotein I antibodies (aβ2GPI) in patients with celiac disease and to analyze the clinical features of antiphospholipid syndrome in these patients. We conducted a prospective case-control study based on the evaluation of IgG, IgM and IgA aCL, and IgG and IgA aβ2GPI in celiac disease patients and in controls. All patients were asked about any occurrence of thrombotic manifestations. In addition, women were asked about pregnancy morbidity. Fifty celiac disease patients and 50 healthy controls were studied. IgM aCL were not detected in study group or in controls. IgG aCL were found in two patients and in one control. IgA aCL were significantly more frequent in celiac disease patients compared with controls (13/50 (26%) vs. 2/50 (4%), p=0.004, OR [95% CI]=9.09 [1.81–50]). There was no statistically significant difference for the prevalence of IgG and IgA aβ2GPI between patients and controls. Clinical features of antiphospholipid syndrome were noted in two patients with negative antibodies. Prevalence of IgM and IgG aCL and of aβ2GPI were not increased in celiac disease. IgA aCL were more frequently detected in celiac disease. However, no clinical features of antiphospholipid syndrome were noted.     

Contribution of <Emphasis Type="Italic">I</Emphasis><Subscript>Kr</Subscript> and <Emphasis Type="Italic">I</Emphasis><Subscript>K1</Subscript> to ventricular repolarization in canine and human myocytes: is there any influence of action potential duration?

Background  The aim of the present work was to study the profile of the rapid delayed rectifier potassium current (I _Kr) and the inward rectifier potassium current (I _K1) during ventricular repolarization as a function of action potential duration and rate of repolarization. Methods  Whole cell configuration of the patch clamp technique was used to monitor I _Kr and I _K1 during the action potential plateau and terminal repolarization. Action potentials recorded at various cycle lengths (0.4–5 s) and repolarizing voltage ramps having various slopes (0.5–3 V/s) were used as command signals. I _Kr and I _K1 were identified as difference currents dissected by E-4031 and BaCl₂, respectively. Results  Neither peak amplitudes nor mean values of I _Kr and I _K1 recorded during the plateau of canine action potentials were influenced by action potential duration. The membrane potential where I _Kr and I _K1 peaked during the terminal repolarization was also independent of action potential duration. Similar results were obtained in undiseased human ventricular myocytes, and also in canine cells when I _Kr and I _K1 were evoked using repolarizing voltage ramps of various slopes. Action potential voltage clamp experiments revealed that the peak values of I _Kr, I _K1, and net outward current during the terminal repolarization were independent of the pacing cycle length within the range of 0.4 and 5 s. Conclusions  The results indicate that action potential configuration fails to influence the amplitude of I _Kr and I _K1 during the ventricular action potential in dogs and humans, suggesting that rate-dependent changes in action potential duration are not likely related to rate-dependent alterations in I _Kr or I _K1 kinetics in these species. Returned for 1. Revision: 5 February 2008 1. Revision received: 11 April 2008 Returned for 2. Revision: 14 May 2008 2. Revision received: 15 May 2008     

The roles of Transforming growth Factor Type β<Subscript>3</Subscript>(TGF-β<Subscript>3</Subscript>) and mast cells in the pathogenesis of scleroderma

Scleroderma is a connective tissue disorder characterised by excessive accumulation of collagen in the skin and internal organs. The most likely explanation for this process is local activation of collagen synthesis from fibroblasts. Our intention was to elucidate whether TGF-₃ and mast cells play a pathogenic role in abnormal connective tissue formation in scleroderma. In this study, skin biopsies from 20 patients with scleroderma and five from healthy individuals were studied by an indirect immunoperoxidase technique to determine the immunoreactivity of TGF-₃ in the dermis. In addition, skin samples were stained with toluidine blue to count the number of mast cells in scleroderma, and tissues were examined under the electron microscope to evaluate the ultrastructural changes. Increased TGF-₃ immunoreactivities were detected in the dermis in the patient's skin, suggesting the presence of a subpopulation responsible for the increased collagen production. Mast cell counts in the skin of patients with scleroderma were significantly greater (19.2 ± 4.1/unit) than those of normal controls (4.4 ± 1.2/unit). Ultrastructural observations indicated that there is a close relationship between the mast cells and fibroblasts. These results suggest that fibrosis in scleroderma could evolve through the activation of fibroblasts and the regulatory mechanisms that appear to modulate the behavior of these cells with respect to collagen production.AcknowledgementWe are grateful for the support of Professor M. Kaya in our work with the electron microscope and thank Professor E. Erten for supplying tissue samples.     

Low Ambient [Cl<Superscript>−</Superscript>] Increases Ca<Superscript>2+</Superscript> Mobilization and Stimulates Nitric Oxide and Prostaglandin E<Subscript>2</Subscript> Production in Human Bronchial Epithelial Cells

Changes in ionic composition of airway surface fluid may modulate airway epithelial functions. We tested the hypothesis that fluctuations of ambient ionic composition could affect airway epithelial Ca²⁺ dynamics and Ca²⁺-dependent cellular functions, including NO release and PGE₂ production in vitro. The responses of intracellular Ca²⁺ concentration ([Ca²⁺]_i) to changes in extracellular Cl⁻ and Na⁺ concentrations ([Cl⁻]_e, [Na⁺]_e) in the human bronchial epithelial cell line, 16HBE cells, were measured by the fura-2 method. The NO release to the medium after lowering [Cl⁻]_e was measured by an amperometric NO sensor. PGE₂ production was measured by radioimmunoassay. Changing to isotonic low [Cl⁻]_e solution by substitution with gluconate caused a sustained increase in [Ca²⁺]_i in a concentration-dependent manner, with the maximal [Ca²⁺]_i increase from the baseline level being 243 ± 110 nM with Cl-free solution. The effect was not altered by thapsigargin but abolished by EGTA and by Cl channel blockers, including diphenylamine-2-carboxylate, disodium 4,4′-diisothiocyanatostilbene-2,2′-disulfonate, and disodium cromoglycate. In contrast, the effect of reduction of [Na⁺]_e by substitution with N-methyl-D-glucamine⁺ on [Ca²⁺]_i was less than that of reduction of [Cl⁻]_e. The reduction of [Cl⁻]_e caused a concentration-dependent rise in NO contents in the medium and PGE₂ production. This release of NO was inhibited by EGTA but not by dexamethasone pretreatment. These results suggest that the decrease in ambient [Cl⁻] induces Ca²⁺ mobilization probably through Ca²⁺ influx, followed by the release of NO and PGE₂, thereby modulating various cellular functions.     

Comparison of serological markers between ACPA<Superscript>+</Superscript> and ACPA<Superscript>−</Superscript> of RA patients

Anti-citrullinated protein/peptide antibodies (ACPA) have recently emerged as sensitive and specific serological markers of rheumatoid arthritis (RA), providing superior alternative of the rheumatoid factor (RF) test in the laboratory diagnostics of RA. We compare the change of serum RF, CRP, IgG, IgM, IgA, total complement, C3 and C4. The sera sample was collected from 123 patients with RA. ACPA were detected with ELISA, and RF, CRP and total complement (Ct), C3 and C4 were examined by automatic biochemical analyzer. Serum RF and total complement concentrations were significantly higher in ACPA+ than in ACPA−, but there were no correlation between ACPA and RF and Ct. Between ACPA+ and ACPA−, there were no significant difference of CRP, IgG, IgM, IgA, total complement, C3 and C4. While there were significant correlation between the concentration of C3 and IgM and ACPA in ACPA+. Conclusion: This is the first study to show that ACPA concentration in ACPA+ patients with RA is positively related to serum IgM and C3 levels.     

Pharmacological Stimulation of β <Subscript>2</Subscript>-adrenergic Receptors (β <Subscript>2</Subscript>AR) Enhances Therapeutic Effectiveness of β <Subscript>1</Subscript>AR Blockade in Rodent Dilated Ischemic Cardiomyopathy

Background. We have reported that β ₂ adrenoreceptor (β ₂AR) stimulation is anti-apoptotic, and has strong beneficial effect on cardiac remodeling in an experimental model of post myocardial infarction chronic heart failure (CHF) in rats. Here we investigate whether the addition of chronic pharmacological β ₂AR stimulation enhances the therapeutic effects of β ₁AR blockade on cardiac remodeling in the same model. Methods and Results. Metoprolol, a β ₁AR blocker, given alone (β ₁) or in combination with β ₂AR agonist, fenoterol (β ₁β ₂) were administered to rats via drinking water for 6 weeks, beginning 2 weeks following permanent coronary ligation. Progressive left ventricular (LV) remodeling of untreated animals, assessed by repeated echocardiography, occurred during the observation time, i.e., 42% and 25% increases in end-systolic and end-diastolic LV volumes respectively, 27% fall in ejection fraction, and 35% infarct expansion. Pressure-volume loop analyses at 2d and 8th post infarction weeks showed continuous deterioration of systolic and diastolic functions and arterio-ventricular mismatch. Histological evaluation at the end of 8 weeks revealed the MI expansion and hypertrophy of cardiomyocytes. β ₁β ₂ prevented LV remodeling, MI expansion and cardiomyocytes hypertrophy to a greater degree than β ₁, due, in large part, to a vasodilatory effect of β ₂AR stimulation and thus improvement of arterio-ventricular mismatch. The abnormal diastolic performance improved only in β ₁β ₂. β ₁β ₂ treatment reduced myocardial apoptosis throughout myocardium, but β ₁ reduced apoptopsis only in the areas remote from MI. Conclusion. The therapeutic effects of chronic β ₁AR blockade on cardiac remodeling of heart failure are enhanced and extended when supplemented with β ₂AR stimulation. This research was supported by the Intramural Research Program of the National Institute on Aging, NIH.     

Emphysema in α<Subscript>1</Subscript>-Antitrypsin Deficiency

Severe alpha(1)-antitrypsin (AAT) deficiency is an inherited disorder that leads to the development of emphysema in smokers at a relatively young age; most are disabled in their forties. Emphysema is caused by the protease-antiprotease imbalance when smoking-induced release of neutrophil elastase in the lung is inadequately inhibited by the deficient levels of AAT, the major inhibitor of neutrophil elastase. This protease-antiprotease imbalance leads to proteolytic damage to lung connective tissue (primarily elastic fibers), and the development of panacinar emphysema. AAT replacement therapy, most often applied by weekly intravenous infusions of AAT purified from human plasma, has been used to partially correct the biochemical defect and raise the serum AAT level above a theoretically protective threshold level of 0.8 g/L. A randomized controlled clinical trial was not considered feasible when purified antitrypsin was released for clinical use. However, AAT replacement therapy has not yet been proven to be clinically effective in reducing the progression of disease in AAT-deficient patients. There was a suggestion of a slower progression of emphysema by computed tomography (CT) scan in a small randomized trial. Two nonrandomized studies comparing AAT-deficient patients already receiving replacement therapy with those not receiving it, and a retrospective study evaluating a decline in FEV(1) before and after replacement therapy, suggested a possible benefit for selected patients. Because of the lack of definitive proof of the clinical effectiveness of AAT replacement therapy and its cost, we recommend reserving AAT replacement therapy for deficient patients with impaired FEV(1) (35-65% of predicted value), who have quit smoking and are on optimal medical therapy but continue to show a rapid decline in FEV(1) after a period of observation of at least 18 months. A randomized placebo-controlled trial using CT scan as the primary outcome measure is required. Screening for AAT deficiency is recommended in patients with chronic irreversible airflow obstruction with atypical features such as early onset of disease or disability in their forties or fifties, or positive family history, and in immediate family members of patients with AAT deficiency.     

Optical Feedback Training of Inhalation with Autohaler<Superscript>®</Superscript> and Turbuhaler<Superscript>®</Superscript> in COPD Patients

The success of inhalation therapy depends on patients inhalation technique and correct handling of the inhalation device. In this study the effort to train correct handling and optimal inhalation technique of patients using Autohaler^® and Turbuhaler^® was assessed. The Bad-Reichenhall-Aerosol-Therapy-Trial (BREATH) was a prospective, randomized, cross-over trial in 200 patients who were not familiar with either of the test systems. The correct handling of Autohaler^® and Turbuhaler^® was assessed by means of a checklist (observation score). An optimal inhalation maneuver was used evaluated with the computer-based Inhalation Manager (optical feedback, computer score). The Autohaler^® reached 6.58±3.64 (mean ± SD) out of nine points in the observation score and 66.85 ± 29.84% in the computer score before training. After training the scores increased significantly to 8.33 ± 2.08 points and 86 ± 23.40% respectively. The use of the Turbuhaler^® also significantly improved from 4.28 ± 4.24 points and 56.67 ± 42.97% to 7.78 ± 2.74 points and 85.80 ± 27.63%, respectively. The significant improvement of patients inhalation technique after training emphasizes the importance of training in inhalation therapy. In addition, it could be demonstrated that the optical feedback given by the Inhalation Manager was a useful tool for improving the inhalation technique of patients using Autohaler^® and Turbuhaler^®.