Biofilm-dependent airway infections: a role for ambroxol?

Biofilms are a key factor in the development of both acute and chronic airway infections. Their relevance is well established in ventilator associated pneumonia, one of the most severe complications in critically ill patients, and in cystic fibrosis, the most common lethal genetic disease in Caucasians. Accumulating evidence suggests that biofilms could have also a role in chronic obstructive pulmonary disease and their involvement in bronchiectasis has been proposed as well. When they grow in biofilms, microorganisms become multidrug-resistant. Therefore the treatment of biofilm-dependent airway infections is problematic. Indeed, it still largely based on measures aiming to prevent the formation of biofilms or remove them once that they are formed. Here we review recent evidence suggesting that the mucokinetic drug ambroxol has specific anti-biofilm properties. We also discuss how additional pharmacological properties of this drug could be beneficial in biofilm-dependent airway infections. Specifically, we review the evidence showing that: 1-ambroxol exerts anti-inflammatory effects by inhibiting at multiple levels the activity of neutrophils, and 2-it improves mucociliary clearance by interfering with the activity of airway epithelium ion channels and transporters including sodium/bicarbonate and sodium/potassium/chloride cotransporters, cystic fibrosis transmembrane conductance regulator and aquaporins. As a whole, the data that we review here suggest that ambroxol could be helpful in biofilm-dependent airway infections. However, considering the limited clinical evidence available up to date, further clinical studies are required to support the use of ambroxol in these diseases.

Effects of pleiotrophin overexpression on mouse skeletal muscles in normal loading and in actual and simulated microgravity

Pleiotrophin (PTN) is a widespread cytokine involved in bone formation, neurite outgrowth, and angiogenesis. In skeletal muscle, PTN is upregulated during myogenesis, post-synaptic induction, and regeneration after crushing, but little is known regarding its effects on muscle function. Here, we describe the effects of PTN on the slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles in mice over-expressing PTN under the control of a bone promoter. The mice were maintained in normal loading or disuse condition, induced by hindlimb unloading (HU) for 14 days. Effects of exposition to near-zero gravity during a 3-months spaceflight (SF) into the Mice Drawer System are also reported. In normal loading, PTN overexpression had no effect on muscle fiber cross-sectional area, but shifted soleus muscle toward a slower phenotype, as shown by an increased number of oxidative type 1 fibers, and increased gene expression of cytochrome c oxidase subunit IV and citrate synthase. The cytokine increased soleus and EDL capillary-to-fiber ratio. PTN overexpression did not prevent soleus muscle atrophy, slow-to-fast transition, and capillary regression induced by SF and HU. Nevertheless, PTN exerted various effects on sarcolemma ion channel expression/function and resting cytosolic Ca(2+) concentration in soleus and EDL muscles, in normal loading and after HU. In conclusion, the results show very similar effects of HU and SF on mouse soleus muscle, including activation of specific gene programs. The EDL muscle is able to counterbalance this latter, probably by activating compensatory mechanisms. The numerous effects of PTN on muscle gene expression and functional parameters demonstrate the sensitivity of muscle fibers to the cytokine. Although little benefit was found in HU muscle disuse, PTN may emerge useful in various muscle diseases, because it exerts synergetic actions on muscle fibers and vessels, which could enforce oxidative metabolism and ameliorate muscle performance.

Atherosclerosis: from biology to pharmacological treatment

A recent explosion in the amount of cardiovascular risk has swept across the globe. Primary prevention is the preferred method to lower cardiovascular risk. Lowering the prevalence of obesity is the most urgent matter, and is pleiotropic since it affects blood pressure, lipid profiles, glucose metabolism, inflammation, and atherothrombotic disease progression. Given the current obstacles, success of primary prevention remains uncertain. At the same time, the consequences of delay and inaction will inevitably be disastrous, and the sense of urgency mounts. Pathological and epidemiological data confirm that atherosclerosis begins in early childhood, and advances seamlessly and inexorably throughout life. Risk factors in childhood are similar to those in adults, and track between stages of life. When indicated, aggressive treatment should begin at the earliest indication, and be continued for many years. For those patients at intermediate risk according to global risk scores, C-reactive protein, coronary artery calcium, and carotid intima-media thickness are available for further stratification. Using statins for primary prevention is recommended by guidelines, is prevalent, but remains under prescribed. Statin drugs are unrivaled, evidence-based, major weapons to lower cardiovascular risk. Even when low density lipoprotein cholesterol targets are attained, over half of patients continue to have disease progression and clinical events. Though clinical evidence is incomplete, altering or raising the blood high density lipoprotein cholesterol level continues to be pursued. The aim of this review is to point out the attention of key aspects of vulnerable plaques regarding their pathogenesis and treatment.

Dietary fibers and cardiometabolic diseases

The high prevalence of cardiovascular disease (CVD) is largely attributable to the contemporary lifestyle that is often sedentary and includes a diet high in saturated fats and sugars and low ingestion of polyunsaturated fatty acids (PUFAs), fruit, vegetables, and fiber. Experimental data from both animals and humans suggest an association between increased dietary fiber (DF) intakes and improved plasma lipid profiles, including reduced low density lipoprotein cholesterol (LDL-C) concentrations. These observations underline that the intake of DF may protect against heart disease and stroke.

Current status of measuring oxidative stress

Although the healthcare field is increasingly aware of the importance of free radicals and oxidative stress, screening and monitoring has not yet become a routine test, since, dangerously, there are no symptoms of this condition. Therefore, in very few cases is oxidative stress addressed. Paradoxically, patients are often advised supplementation with antioxidants and or diets with increased antioxidant profile, which ranges from vitamins to minerals and acts against oxidative stress states; even more so, no test is advised to assess whether the patient is under attack by free radicals or has a depleted antioxidant capacity. Oxidative stress i s an imbalance between free radicals (ROS, reactive oxygen species) production and existing antioxidant capacity (AC); living organisms have a complex antioxidant power. A decrease in ROS formation is often due to an increase in antioxidant capacity, while a decrease in the AC may be associated to increased ROS values. But, this is not always apparently so. Test kits for photometric determinations that are applicable to small laboratories are increasingly available.

Multiple pathological events in exercised dystrophic mdx mice are targeted by pentoxifylline: outcome of a large array of in vivo and ex vivo tests

The phosphodiesterases inhibitor pentoxifylline gained attention for Duchenne muscular dystrophy therapy for its claimed anti-inflammatory, antioxidant, and antifibrotic action. A recent finding also showed that pentoxifylline counteracts the abnormal overactivity of a voltage-independent calcium channel in myofibers of dystrophic mdx mice. The possible link between workload, altered calcium homeostasis, and oxidative stress pushed toward a more detailed investigation. Thus a 4- to 8-wk treatment with pentoxifylline (50 mg·kg−1·day−1 ip) was performed in mdx mice, undergoing or not a chronic exercise on treadmill. In vivo, the treatment partially increased forelimb strength and enhanced resistance to treadmill running in exercised animals. Ex vivo, pentoxifylline restored the mechanical threshold, an electrophysiological index of calcium homeostasis, and reduced resting cytosolic calcium in extensor digitorum longus muscle fibers. Mn quenching and patch-clamp technique confirmed that this effect was paralleled by a drug-induced reduction of membrane permeability to calcium. The treatment also significantly enhanced isometric tetanic tension in mdx diaphragm. The plasma levels of creatine kinase and reactive oxygen species were both significantly reduced in treated-exercised animals. Dihydroethidium staining, used as an indicator of reactive oxygen species production, showed that pentoxifylline significantly reduced the exercise-induced increase in fluorescence in the mdx tibialis anterior muscle. A significant decrease in connective tissue area and profibrotic cytokine transforming growth factor-β1 was solely found in tibialis anterior muscle. In both diaphragm and gastrocnemius muscle, a significant increase in neural cell adhesion molecule-positive area was instead observed. This data supports the interest toward pentoxifylline and allows insight in the level of cross talk between pathogenetic events in workloaded dystrophic muscle.

Blood cholesterol concentration measured by CR3000: fingerstick versus venous sampling

Currently, the clinical practice of desktop or Point of Care (PoC) analyzers for lipid measurements has gained wide popularity. Designed to quickly perform measurements on microlitre(microL) quantities of blood, these instruments can be used in non-laboratory settings, such as physicians offices or field-testing sites and can provide measurements in whole blood, serum, or plasma, using either venous or capillary blood samples. The aim of this study is to examine the relationship between cholesterol determinations in venous and capillary samples using the CR3000 PoC system. The study was performed on 21 unselected adult volunteers, and no exclusion criteria was adopted. The mean cholesterol concentration for the venous blood samples measured was 164 mg/dL. The values obtained in the capillary blood samples averaged 168 mg/dL, which is only slightly higher (e.g., 2.87%) than the venous sample measurements. Moreover, the total variance was statistically similar for venous and capillary measurements (F value = 1.199, where the upper critical value of the F distribution is 2.124, p < 0.05). The results of our study support the concept that CR3000 total cholesterol testing can be performed safely and accurately in either venous or capillary specimens.

Securebox: a multibiopsy sample container for specimen identification and transport

OBJECTIVE

To describe an original multicompartment disposable container for tissue surgical specimens or serial biopsy samples (Securebox).

STUDY DESIGN

The increasing number of pathology samples from a single patient required for an accurate diagnosis led us to design and manufacture a unique container with 4 boxes; in each box 1 or more biopsy samples can be lodged. A magnification lens on a convex segment of the plastic framework allows inspection of macroscopic details of the recovered specimens. We investigated 400 randomly selected cases (compared with 400 controls) who underwent multiple biopsies from January 2006 to January 2007 to evaluate compliance with the new procedure and detect errors resulting from missing some of the multiple specimens or to technical mistakes during the procedure or delivery that might have compromised the final diagnosis.

RESULTS

Using our Securebox, the percentage of oatients whose diagnosis failed or could not be reached was O.5% compared to 4% with the traditional method (p = 0.0012). Moreover, the percentage of medical and nursing staff who were satisfied with the Securebox compared to the traditional methodwas 85% vs. 15%, respectively (p < 0.0001). The average number of days spent bto reach a proper diagnosis based on the usage of the Securebox was 3.38 +/- 1.16 SD compared to 6.76 +/- 0.52 SD with the traditional method (p < 0.0001).

CONCLUSION

The compact Securebox makes it safer and easier to introduce the specimens and to ship them to the pathology laboratories, reducing the risk of error.

Accuracy of analyses for lipid profile parameters as measured with the CR3000 system

Total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels are positively related to coronary heart disease (CHD), and high-density lipoprotein cholesterol (HDLC) levels are negatively related to CHD. Efforts to identify and treat people at increased risk based on cholesterol and lipoprotein levels have led to more lipid testing and the need for very reliable test results. Point-of-care testing (POCT) has developed from the demand for analytical information more fastly than is available from central laboratories. By carrying the analysis closer to the patient some process steps have been eliminated, facilitating a shorter time to result and faster management response with improved outcomes. Thus benefits include better therapeutic turnaround times (TATs), decreased blood loss as a result of reduced phlebotomy secondary to clinical improvement and diminished resource utilization. These effects depend on acceptable analytical performance in comparison with central laboratory techniques and in relation to clinical criteria.

Duchenne muscle activity evaluation and muscle function preservation: is it possible a prophylactic strategy?

Duchenne muscular dystrophy yields pervasive and progressive muscle mass loss. In the current measures relating to the monitoring of disease progression the following are relevant (i): the type of scale used, (ii) the clinical significance of the attribute being measured and (iii) the mathematical properties of the data provided. The high prevalence of obesity at an early stage of this pathology could result not only from reduced physical activity, but also from low resting energy expenditure, abnormal nutrient utilization or overfeeding. This muscle weakness may be attenuated by regular low-intensity exercise. However, there is a critical lack of data to support appropriate exercise prescription. Because inappropriate activity may exacerbate the dystrophic process, a systematic analysis of muscle function to determine potential exercise load thresholds to avoid injury in dystrophic mice and dogs, and then in humans is recommended.

Oxidative stress tests: overview on reliability and use. Part II

Although the healthcare field is increasingly aware of the importance of free radicals and oxidative stress, screening and monitoring has yet become a routine test since, dangerously, there are no symptoms of this condition. Therefore, in very few cases is oxidative stress addressed. Paradoxically, patients are often advised supplementation with antioxidants and or diets with increased antioxidant profile, which range from vitamins to minerals which is action against oxidative stress states and even more so no test is advised to assess whether the patient is under attack by free radicals or has a depleted antioxidant capacity. Hence oxidative stress is an imbalance between free radicals (ROS, Reactive Oxygen Species) production and existing antioxidant capacity (AC), living organisms have a complex anti-oxidant power. A decrease in ROS formation is often due to an increase in antioxidant capacity whilst an increase in the AC may be associated to decreased ROS values. But this is not always apparently so. Test kits for photometric determinations applicable to small laboratories are increasingly available.

Oxidative stress tests: overview on reliability and use. Part I

Monitoring oxidative stress in humans is achieved by assaying products of oxidative damage or by investigating the potential of an organism, tissue or body fluids to withstand further oxidation. Unfortunately, there is little consensus concerning the selection of parameters of oxidative stress or antioxidant state to be determined in defined patients or diseases. This is not only due to the uncertainty wheter or not a certain parameter is playing a causative role. Moreover, the methods of determination described in the literature represent very different levels of analytical practicability, costs, and quality. Generally accepted reference ranges and interpretations of pathological situations are lacking as well as control materials. At present, the situation is changing dramatically and sophisticated methods like HPLC (High Performance Liquid Chromatography) and immunochemical determinations have become more and more common standard.

Oxidative stress detection: what for? Part II

Oxygen-free radicals, more generally known as reactive oxygen species (ROS) along with nitrogen species (RNS) are well recognised for playing a dual role both deleterious and beneficial species. The cumulative generation of ROS/RNS through either endogenous or exogenous insults is termed oxidative stress and is common for many types of diseases that are linked with altered redox regulation of cellular signalling pathways.

Oxidative stress detection: what for? Part I

In this paper we review the diseases, such as cancer, arteriosclerosis, arthritis, neurodegenerative disorders, whose emerging pathogenetic evidence by Free Radicals has been shown either from experimental or from clinical point of view. In the last 10 years the growing evidence of a co-causative responsibility of oxidative stress in some chronic and acute illnesses highlighted the need to improve the diagnostic potential as well as the algorythm of an effective treatment plan. An exhaustive basic description of the Free Radicals action mechanism in different parenchymas to produce damage and clinical symptoms is the very preliminary background to any further investigation as to the specific diseases-oriented diagnostic tests as well as to a rationale therapy.

[Duchenne muscular dystrophy: rational basis, state of the art]

Duchenne muscular dystrophy (DMD) is an X-linked recessive disease that affects approximately 1 in 3500 male births. Boys with Duchenne have a progressive and predictable muscle deterioration: muscles lack dystrophin, a protein essential for membrane stability, whose absence induces contraction-related membrane damage and activation of the inflammatory cascade leading to muscle failure, necrosis, fibrosis. Although DMD is present at birth, clinical symptoms are not evident until 2-6 years of age. Initial symptoms include leg weakness, increasing spine kyphosis, and a waddle-like gait. Continuous muscle wasting leads to progressively weaker muscles, usually leading DMD patients on wheelchair by the age of 8-12. Scoliosis develops in 90% of boys who use a wheelchair full-time. Progression of muscle degeneration and worsening clinical symptoms lead to death in the late twenties from respiratory/cardiac failure.

[Duchenne muscular dystrophy: perspectives of treatment]

Although the cloning of the dystrophin gene has led to major advances in the knowledge of the molecular, genetic basis of Duchenne Muscular Dystrophy (DMD), Becker Muscular Dystrophy (BMD), and other muscular dystrophies, with mutations of genes encoding the dystrophin-associated glycoprotein complex, an effective therapy is still lacking. This review reports some of the most promising pharmacological, molecular and cellular approaches to DMD/BMD. All together, these exciting developments are just puzzling work hypothesis whose clinical developments is on the way.

Glucoraphanin, the bioprecursor of the widely extolled chemopreventive agent sulforaphane found in broccoli, induces phase-I xenobiotic metabolizing enzymes and increases free radical generation in rat liver

Epidemiological and animal studies linking high fruit and vegetable consumption to lower cancer risk have strengthened the belief that long-term administration of isolated naturally occurring dietary constituents could reduce the risk of cancer. In recent years, metabolites derived from phytoalexins, such as glucoraphanin found in broccoli and other cruciferous vegetables (Brassicaceae), have gained much attention as potential cancer chemopreventive agents. The protective effect of these micronutrients is assumed to be due to the inhibition of Phase-I carcinogen-bioactivating enzymes and/or induction of Phase-II detoxifying enzymes, an assumption that still remains uncertain. The protective effect of glucoraphanin is thought to be due to sulforaphane, an isothiocyanate metabolite produced from glucoraphanin by myrosinase. Here we show, in rat liver, that while glucoraphanin slightly induces Phase-II enzymes, it powerfully boosts Phase-I enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), nitrosamines and olefins. Induction of the cytochrome P450 (CYP) isoforms CYP1A1/2, CYP3A1/2 and CYP2E1 was confirmed by Western immunoblotting. CYP induction was paralleled by an increase in the corresponding mRNA levels. Concomitant with this Phase-I induction, we also found that glucoraphanin generated large amount of various reactive radical species, as determined by electron paramagnetic resonance (EPR) spectrometry coupled to a radical-probe technique. This suggests that long-term uncontrolled administration of glucoraphanin could actually pose a potential health hazard.