Off-pump coronary artery bypass grafting: Misperceptions and misconceptions

Coronary artery bypass grafting (CABG) continues to be one of the most commonly performed cardiac surgical procedures worldwide. Conventional CABG performed on cardiopulmonary bypass termed on-pump CABG is regarded as the gold standard. However, on-pump CABG results in several physiologic derangements including but not limited to thrombocytopenia, activation of complement factors, immune suppression, and inflammatory responses leading to organ dysfunction. Furthermore, manipulating an atherosclerotic ascending aorta during cannulation and cross-clamping can predispose to embolization and stroke risk. Recognition of these detrimental effects of on-pump CABG resulted in resurgence of off-pump CABG nearly two decades ago. Off-pump CABG since its resurgence has been a subject of intensive scrutiny and speculation. Despite numerous retrospective nonrandomized studies, prospective randomized trials, and meta-analyses validating the safety and efficacy of off-pump CABG, opponents of the technique have persistently demanded abandonment of off-pump CABG. Several misconceptions and misperceptions are used as an excuse for such demands. This review article examines published scientific evidence to evaluate these misperceptions and misconceptions about off-pump CABG.

Impact of HLA-G analysis in prevention, diagnosis and treatment of pathological conditions

Human leukocyte antigen-G (HLA-G) is a non-classical HLA class I molecule that differs from classical HLA class I molecules by low polymorphism and tissue distribution. HLA-G is a tolerogenic molecule with an immune-modulatory and anti-inflammatory function on both innate and adaptative immunity. This peculiar characteristic of HLA-G has led to investigations of its role in pathological conditions in order to define possible uses in diagnosis, prevention and treatment. In recent years, HLA-G has been shown to have an important implication in different inflammatory and autoimmune diseases, pregnancy complications, tumor development and aggressiveness, and susceptibility to viral infections. In fact, HLA-G molecules have been reported to alternate at both genetic and protein level in different disease situations, supporting its crucial role in pathological conditions. Specific pathologies show altered levels of soluble (s)HLA-G and different HLA-G gene polymorphisms seem to correlate with disease. This review aims to update scientific knowledge on the contribution of HLA-G in managing pathological conditions.

Bone marrow cell-based regenerative therapy for liver cirrhosis

Bone marrow cells are capable of differentiation into liver cells. Therefore, transplantation of bone marrow cells has considerable potential as a future therapy for regeneration of damaged liver tissue. Autologous bone marrow infusion therapy has been applied to patients with liver cirrhosis, and improvement of liver function parameters has been demonstrated. In this review, we summarize clinical trials of regenerative therapy using bone marrow cells for advanced liver diseases including cirrhosis, as well as topics pertaining to basic in vitro or in vivo approaches in order to outline the essentials of this novel treatment modality.

Sonoporation: Gene transfer using ultrasound

Genes can be transferred using viral or non-viral vectors. Non-viral methods that use plasmid DNA and short interference RNA (siRNA) have advantages, such as low immunogenicity and low likelihood of genomic integration in the host, when compared to viral methods. Non-viral methods have potential merit, but their gene transfer efficiency is not satisfactory. Therefore, new methods should be developed. Low-frequency ultrasound irradiation causes mechanical perturbation of the cell membrane, allowing the uptake of large molecules in the vicinity of the cavitation bubbles. The collapse of these bubbles generates small transient holes in the cell membrane and induces transient membrane permeabilization. This formation of small pores in the cell membrane using ultrasound allows the transfer of DNA/RNA into the cell. This phenomenon is known as sonoporation and is a gene delivery method that shows great promise as a potential new approach in gene therapy. Microbubbles lower the threshold of cavity formation. Complexes of therapeutic genes and microbubbles improve the transfer efficiency of genes. Diagnostic ultrasound is potentially a suitable sonoporator because it allows the real-time monitoring of irradiated fields.

An overview of translational (radio)pharmaceutical research related to certain oncological and non-oncological applications

Translational medicine pursues the conversion of scientific discovery into human health improvement. It aims to establish strategies for diagnosis and treatment of diseases. Cancer treatment is difficult. Radio-pharmaceutical research has played an important role in multiple disciplines, particularly in translational oncology. Based on the natural phenomenon of necrosis avidity, OncoCiDia has emerged as a novel generic approach for treating solid malignancies. Under this systemic dual targeting strategy, a vascular disrupting agent first selectively causes massive tumor necrosis that is followed by iodine-131 labeled-hypericin (¹²³I-Hyp), a necrosis-avid compound that kills the residual cancer cells by crossfire effect of beta radiation. In this review, by emphasizing the potential clinical applicability of OncoCiDia, we summarize our research activities including optimization of radioiodinated hypericin Hyp preparations and recent studies on the biodistribution, dosimetry, pharmacokinetic and, chemical and radiochemical toxicities of the preparations. Myocardial infarction is a global health problem. Although cardiac scintigraphy using radioactive perfusion tracers is used in the assessment of myocardial viability, searching for diagnostic imaging agents with authentic necrosis avidity is pursued. Therefore, a comparative study on the biological profiles of the necrosis avid ¹²³I-Hyp and the commercially available ^99mTc-Sestamibi was conducted and the results are demonstrated. Cholelithiasis or gallstone disease may cause gallbladder inflammation, infection and other severe complications. While studying the mechanisms underlying the necrosis avidity of Hyp and derivatives, their naturally occurring fluorophore property was exploited for targeting cholesterol as a main component of gallstones. The usefulness of Hyp as an optical imaging agent for cholelithiasis was studied and the results are presented. Multiple uses of automatic contrast injectors may reduce costs and save resources. However, cross-contaminations with blood-borne pathogens of infectious diseases may occur. We developed a radioactive method for safety evaluation of a new replaceable patient-delivery system. By mimicking pathogens with a radiotracer, we assessed the feasibility of using the system repeatedly without septic risks. This overview is deemed to be interesting to those involved in the related fields for translational research.

Bifunctional staining for ex vivo determination of area at risk in rabbits with reperfused myocardial infarction

AIM: To develop a method for studying myocardial area at risk (AAR) in ischemic heart disease in correlation with cardiac magnetic resonance imaging (cMRI).

METHODS: Nine rabbits were anesthetized, intubated and subjected to occlusion and reperfusion of the left circumflex coronary artery (LCx) to induce myocardial infarction (MI). ECG-triggered cMRI with delayed enhancement was performed at 3.0 T. After euthanasia, the heart was excised with the LCx re-ligated. Bifunctional staining was performed by perfusing the aorta with a homemade red-iodized-oil (RIO) dye. The heart was then agar-embedded for ex vivo magnetic resonance imaging and sliced into 3 mm-sections. The AAR was defined by RIO-staining and digital radiography (DR). The perfusion density rate (PDR) was derived from DR for the AAR and normal myocardium. The MI was measured by in vivo delayed enhancement (iDE) and ex vivo delayed enhancement (eDE) cMRI. The AAR and MI were compared to validate the bifunctional straining for cardiac imaging research. Linear regression with Bland-Altman agreement, one way-ANOVA with Bonferroni’s multiple comparison, and paired t tests were applied for statistics.

RESULTS: All rabbits tolerated well the surgical procedure and subsequent cMRI sessions. The open-chest occlusion and close-chest reperfusion of the LCx, double suture method and bifunctional staining were successfully applied in all animals. The percentage MI volumes globally (n = 6) and by slice (n = 25) were 36.59% ± 13.68% and 32.88% ± 12.38% on iDE, and 35.41% ± 12.25% and 32.40% ± 12.34% on eDE. There were no significant differences for MI determination with excellent linear regression correspondence (r_global = 0.89; r_slice = 0.9) between iDE and eDE. The percentage AAR volumes globally (n = 6) and by slice (n = 25) were 44.82% ± 15.18% and 40.04% ± 13.64% with RIO-staining, and 44.74% ± 15.98% and 40.48% ± 13.26% by DR showing high correlation in linear regression analysis (r_global = 0.99; r_slice = 1.0). The mean differences of the two AAR measurements on Bland-Altman were almost zero, indicating RIO-staining and DR were essentially equivalent or inter-replaceable. The AAR was significantly larger than MI both globally and slice-by-slice (P < 0.01). After correction with the background and the blank heart without bifunctional staining (n = 3), the PDR for the AAR and normal myocardium was 32% ± 15% and 35.5% ± 35%, respectively, which is significantly different (P < 0.001), suggesting that blood perfusion to the AAR probably by collateral circulation was only less than 10% of that in the normal myocardium.

CONCLUSION: The myocardial area at risk in ischemic heart disease could be accurately determined postmortem by this novel bifunctional staining, which may substantially contribute to translational cardiac imaging research.

Effect of low level laser therapy on dental pulp during orthodontic movement

AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp.

METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1 (G1) absolute control; group 2 (G2) only laser irradiation; group 3 (G3) exposed only to orthodontics; and group 4 (G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW (energy 80 J/cm², 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin (HE), Masson’s Trichrome method and Gomori’s method.

RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response (dental pulp) and hard tissue response (dentin and predentin). There was no inflammation (chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study.

CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.

Pre-participation screening for the prevention of sudden cardiac death in athletes

Pre-partecipation screening is the systematic practice of medically evaluating large populations of athletes before participation in sport activities for the purpose of identifying abnormalities that could cause disease progression or sudden death. In order to prevent sudden cardiac death (SCD), cardiovascular screening should include a strategy for excluding high-risk subjects from athletic and vigorous exercise. There are two major screening programmes in the world. In the United States competitive athletes are screened by means of family and personal history and physical examination. In Italy there is a mandatory screening for competitive athletes, which includes a resting electrocardiogram (ECG) for the detection of cardiac abnormalities. The most important issue to be addressed is whether a screened subject is really guaranteed that she/he is not suffering from any cardiac disease or at risk for SCD. Conceivably, the introduction of echocardiogram during the pre-participation screening, could be reasonable, despite the discrete sensitivity of ECG, in raising clinical suspicions of severe cardiac alterations predisposing to SCD. It is clear that the cost-benefit ratio per saved lives of the ECG screening is a benchmark of the Public Health policy. On the contrary, the additional introduction of echocardiography in a large population screening programme seems to be too much expansive for the Public Health and for this reason not easily practicable, even if useful and not invasive. Even if we strongly believe that a saved life is more important than any cost-efficacy evaluation, the issue of the economical impact of this approach should be further assessed.

Methods for the extraction and RNA profiling of exosomes

AIM: To develop protocols for isolation of exosomes and characterization of their RNA content.

METHODS: Exosomes were extracted from HeLa cell culture media and human blood serum using the Total exosome isolation (from cell culture media) reagent, and Total exosome isolation (from serum) reagent respectively. Identity and purity of the exosomes was confirmed by Nanosight^® analysis, electron microscopy, and Western blots for CD63 marker. Exosomal RNA cargo was recovered with the Total exosome RNA and protein isolation kit. Finally, RNA was profiled using Bioanalyzer and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) methodology.

RESULTS: Here we describe a novel approach for robust and scalable isolation of exosomes from cell culture media and serum, with subsequent isolation and analysis of RNA residing within these vesicles. The isolation procedure is completed in a fraction of the time, compared to the current standard protocols utilizing ultracentrifugation, and allows to recover fully intact exosomes in higher yields. Exosomes were found to contain a very diverse RNA cargo, primarily short sequences 20-200 nt (such as miRNA and fragments of mRNA), however longer RNA species were detected as well, including full-length 18S and 28S rRNA.

CONCLUSION: We have successfully developed a set of reagents and a workflow allowing fast and efficient extraction of exosomes, followed by isolation of RNA and its analysis by qRT-PCR and other techniques.

Confidence limit calculation for antidotal potency ratio derived from lethal dose 50

AIM: To describe confidence interval calculation for antidotal potency ratios using bootstrap method.

METHODS: We can easily adapt the nonparametric bootstrap method which was invented by Efron to construct confidence intervals in such situations like this. The bootstrap method is a resampling method in which the bootstrap samples are obtained by resampling from the original sample.

RESULTS: The described confidence interval calculation using bootstrap method does not require the sampling distribution antidotal potency ratio. This can serve as a substantial help for toxicologists, who are directed to employ the Dixon up-and-down method with the application of lower number of animals to determine lethal dose 50 values for characterizing the investigated toxic molecules and eventually for characterizing the antidotal protections by the test antidotal systems.

CONCLUSION: The described method can serve as a useful tool in various other applications. Simplicity of the method makes it easier to do the calculation using most of the programming software packages.

Protein dynamics via computational microscope

The purpose of this overview is to provide a concise introduction to the methodology and current advances in molecular dynamics (MD) simulations. MD simulations emerged as a powerful and popular tool to study dynamic behavior of proteins and macromolecule complexes at the atomic resolution. This approach can extend static structural data, such as X-ray crystallography, into dynamic domains with realistic timescales (up to millisecond) and high precision, therefore becoming a veritable computational microscope. This perspective covers current advances and methodology in the simulation of protein folding and drug design as illustrated by several important published examples. Overall, recent progress in the simulation field points to the direction that MD will have significant impact on molecular biology and pharmaceutical science.

LC-MS/MS analysis of 2-aminothiazoline-4-carboxylic acid as a forensic biomarker for cyanide poisoning

AIM

To demonstrate the potential of using 2-aminothiazoline-4-carboxylic acid (ATCA) as a novel biomarker/forensic biomarker for cyanide poisoning.

METHODS

A sensitive method was developed and employed for the identification and quantification of ATCA in biological samples, where the sample extraction and clean up were achieved by solid phase extraction (SPE). After optimization of SPE procedures, ATCA was analyzed by high performance liquid chromatography-tandem mass spectrometry. ATCA levels following the administration of different doses of potassium cyanide (KCN) to mice were measured and compared to endogenous ATCA levels in order to study the significance of using ATCA as a biomarker for cyanide poisoning.

RESULTS

A custom made analytical method was established for a new (mice) model when animals were exposed to increasing KCN doses. The application of this method provided important new information on ATCA as a potential cyanide biomarker. ATCA concentration in mice plasma samples were increased from 189 ± 28 ng/mL (n = 3) to 413 ± 66 ng/mL (n = 3) following a 10 mg/kg body weight dose of KCN introduced subcutaneously. The sensitivity of this analytical method proved to be a tool for measuring endogenous level of ATCA in mice organs as follows: 1.2 ± 0.1 μg/g for kidney samples, 1.6 ± 0.1 μg/g for brain samples, 1.8 ± 0.2 μg/g for lung samples, 2.9 ± 0.1 μg/g for heart samples, and 3.6 ± 0.9 μg/g for liver samples.

CONCLUSION

This finding suggests that ATCA has the potential to serve as a plasma biomarker / forensic biomarker for cyanide poisoning.

LC-MS/MS analysis of 2-aminothiazoline-4-carboxylic acid as a forensic biomarker for cyanide poisoning

AIM: To demonstrate the potential of using 2-aminothiazoline-4-carboxylic acid (ATCA) as a novel biomarker/forensic biomarker for cyanide poisoning.

METHODS: A sensitive method was developed and employed for the identification and quantification of ATCA in biological samples, where the sample extraction and clean up were achieved by solid phase extraction (SPE). After optimization of SPE procedures, ATCA was analyzed by high performance liquid chromatography-tandem mass spectrometry. ATCA levels following the administration of different doses of potassium cyanide (KCN) to mice were measured and compared to endogenous ATCA levels in order to study the significance of using ATCA as a biomarker for cyanide poisoning.

RESULTS: A custom made analytical method was established for a new (mice) model when animals were exposed to increasing KCN doses. The application of this method provided important new information on ATCA as a potential cyanide biomarker. ATCA concentration in mice plasma samples were increased from 189 ± 28 ng/mL (n = 3) to 413 ± 66 ng/mL (n = 3) following a 10 mg/kg body weight dose of KCN introduced subcutaneously. The sensitivity of this analytical method proved to be a tool for measuring endogenous level of ATCA in mice organs as follows: 1.2 ± 0.1 μg/g for kidney samples, 1.6 ± 0.1 μg/g for brain samples, 1.8 ± 0.2 μg/g for lung samples, 2.9 ± 0.1 μg/g for heart samples, and 3.6 ± 0.9 μg/g for liver samples.

CONCLUSION: This finding suggests that ATCA has the potential to serve as a plasma biomarker / forensic biomarker for cyanide poisoning.

Statistical models for meta-analysis: A brief tutorial

Aggregate data meta-analysis is currently the most commonly used method for combining the results from different studies on the same outcome of interest. In this paper, we provide a brief introduction to meta-analysis, including a description of aggregate and individual participant data meta-analysis. We then focus the rest of the tutorial on aggregate data meta-analysis. We start by first describing the difference between fixed and random-effects meta-analysis, with particular attention devoted to the latter. This is followed by an example using the random-effects, method of moments approach and includes an intercept-only model as well as a model with one predictor. We then describe alternative random-effects approaches such as maximum likelihood, restricted maximum likelihood and profile likelihood as well as a non-parametric approach. A brief description of selected statistical programs available to conduct random-effects aggregate data meta-analysis, limited to those that allow both an intercept-only as well as at least one predictor in the model, is given. These descriptions include those found in an existing general statistics software package as well as one developed specifically for an aggregate data meta-analysis. Following this, some of the disadvantages of random-effects meta-analysis are described. We then describe recently proposed alternative models for conducting aggregate data meta-analysis, including the varying coefficient model. We conclude the paper with some recommendations and directions for future research. These recommendations include the continued use of the more commonly used random-effects models until newer models are more thoroughly tested as well as the timely integration of new and well-tested models into traditional as well as meta-analytic-specific software packages.

Use of the varying coefficient model in an exercise and depression meta-analysis

AIM: Use a recently developed varying coefficient model to determine the effects of exercise in adults with depression.

METHODS: Data from a recent meta-analysis addressing the effects of exercise on depression in adults were used. Studies were limited to randomized controlled intervention trials of any type of chronic exercise (for example, walking and jogging) in adults greater than or equal to 18 years of age with a diagnosis of depression. For each study, the standardized mean difference (exercise minus control) effect size for depression, adjusted for small-sample bias, was calculated. Variance statistics for each effect size and pooling of results were calculated using the recently proposed varying coefficient (VC) model for standardized mean differences. Standardized effect-sizes of 0.20, 0.50 and 0.80 were considered to represent small, medium and large effects. Results were considered statistically significant if the 95% confidence intervals did not cross 0, with negative results indicative of reductions in depression. These findings were then compared with results using traditional random-effects (RE) models.

RESULTS: A total of 23 studies representing 907 men and women (476 exercise, 431 control) were pooled for analysis. Both RE and VC models resulted in large, statistically significant improvements in depression as a result of exercise in adults. However, the VC model resulted in a larger overall effect size as well as confidence intervals that were narrower than previously reported using the RE model. The overall mean effect size for the RE model was -0.82 with a 95% confidence interval of -1.12 to -0.51. For the VC model, overall mean effect size was -0.88 with a 95% confidence interval of -1.08 to -0.68. The relative difference between the RE and VC approaches was 7.3%.

CONCLUSION: The VC model, a potentially preferable model, confirms the positive effects of exercise on depression in adults.

Factors influencing teamwork and collaboration within a tertiary medical center

AIM: To understand how work climate and related factors influence teamwork and collaboration in a large medical center.

METHODS: A survey of 3462 employees was conducted to generate responses to Sexton’s Safety Attitudes Questionnaire (SAQ) to assess perceptions of work environment via a series of five-point, Likert-scaled questions. Path analysis was performed, using teamwork (TW) and collaboration (CO) as endogenous variables. The exogenous variables are effective communication (EC), safety culture (SC), job satisfaction (JS), work pressure (PR), and work climate (WC). The measurement instruments for the variables or summated subscales are presented. Reliability of each sub-scale are calculated. Alpha Cronbach coefficients are relatively strong: TW (0.81), CO (0.76), EC (0.70), SC (0.83), JS (0.91), WP (0.85), and WC (0.78). Confirmatory factor analysis was performed for each of these constructs.

RESULTS: Path analysis enables to identify statistically significant predictors of two endogenous variables, teamwork and intra-organizational collaboration. Significant amounts of variance in perceived teamwork (R² = 0.59) and in collaboration (R² = 0.75) are accounted for by the predictor variables. In the initial model, safety culture is the most important predictor of perceived teamwork, with a β weight of 0.51, and work climate is the most significant predictor of collaboration, with a β weight of 0.84. After eliminating statistically insignificant causal paths and allowing correlated predictors1, the revised model shows that work climate is the only predictor positively influencing both teamwork (β = 0.26) and collaboration (β = 0.88). A relatively weak positive (β = 0.14) but statistically significant relationship exists between teamwork and collaboration when the effects of other predictors are simultaneously controlled.

CONCLUSION: Hospital executives who are interested in improving collaboration should assess the work climate to ensure that employees are operating in a setting conducive to intra-organizational collaboration.

Dissolution mechanism of calcium apatites in acids: A review of literature

Eight dissolution models of calcium apatites (both fluorapatite and hydroxyapatite) in acids were drawn from the published literature, analyzed and discussed. Major limitations and drawbacks of the models were conversed in details. The models were shown to deal with different aspects of apatite dissolution phenomenon and none of them was able to describe the dissolution process in general. Therefore, an attempt to combine the findings obtained by different researchers was performed which resulted in creation of the general description of apatite dissolution in acids. For this purpose, eight dissolution models were assumed to complement each other and provide the correct description of the specific aspects of apatite dissolution. The general description considers all possible dissolution stages involved and points out to some missing and unclear phenomena to be experimentally studied and verified in future. This creates a new methodological approach to investigate reaction mechanisms based on sets of affine data, obtained by various research groups under dissimilar experimental conditions.

Electrodermal mapping: A new technology

AIM: To provide the first objective data to show that the electrical conditions of an acupuncture point and a non acupuncture point are different.

METHODS: A newly developed multi-channel skin resistance measuring system is used to characterize the variability in electrical resistance measurements in and around an acupoint, a non-acupoint and a scar. The system measures the electrical skin resistance at 48 points, both absolutely and continuously. The study was performed at the Medical University of Graz in 10 male volunteers, aged between 20 and 30 years and of eurocaucasian descent. With software developed along with the hardware, both a high-resolution measurement and a graphical presentation of possible changes in electrical resistance in the region of interest are possible.

RESULTS: Using the new electrodermal mapping system, differences in skin resistance of an acupoint, a non-acupoint and around a scar could be observed. The values varied within a range of up to 100-500 kOhm. Thermography measurements for control reasons in the same spot did not show these changes.

CONCLUSION: Electrodermal mapping is an innovative method for highly precise skin resistance measurements.

Improving psychotherapy research: The example of mindfulness based interventions

The increasing number and sophistication of available psychotherapies suggests that a critical appraisal of the methodological issues of psychotherapy studies is highly needed. Several key questions regarding the efficacy of a given intervention, the understanding of whether positive effects observed following the delivery of a psychotherapeutic intervention are specifically attributable to the intervention itself or to other "non specific" factors, such as benefit expectations, therapist attention and support, and the possibility of improving psychotherapy research need an answer. This, in turn, could provide clinicians with more rigorous information about psychotherapy outcomes and could properly address several shortcomings that are frequently observed in current psychotherapy studies. Accordingly, in this editorial I will highlight some of the most important critical issues that a well designed psychotherapy study should take into account, including the need for appropriate control groups, appropriate randomization and blinding procedures, and the importance of performing appropriately powered studies that include a sufficiently long follow-up period. Finally, I will build on my expertise in the field of mindfulness based interventions, in particular mindfulness based stress reduction and mindfulness based cognitive therapy, to show how such issues have been and can be successfully implemented in the design of future psychotherapy studies.

What is the purpose of launching the World Journal of Methodology?

Congratulations to the publisher, members of the editorial board of the journal, all the authors and readers for launching the World Journal of Methodology (WJM) as a new member of the World series journal family! Scientific advances and important breakthroughs have been facilitated by well developed methodologies or techniques and any misleading findings and theories are exclusively attributable to certain methodological defects. Thus, the role of appropriate methodologies in the development of science and technology cannot be overemphasized and the need for inaugurating this new journal is self-evident. The WJM is a peer-reviewed open-access periodical centered in biomedical sciences but with multidisciplinary coverage. If you want to share any new methodologies, any experiences of the application or improvement of such methodologies and any methodology-related academic issues with your peers, you will find the WJM a good media to publish your papers!

Risk of fracture and pneumonia from acid suppressive drugs

A recently published systematic review and meta-analysis, incorporating all relevant studies on the association of acid suppressive medications and pneumonia identified up to August 2009, revealed that for every 200 patients, treated with acid suppressive medication, one will develop pneumonia. They showed the overall risk of pneumonia was higher among people using proton pump inhibitors (PPIs) [adjusted odds ratio (OR) = 1.27, 95% CI: 1.11-1.46, I² = 90.5%] and Histamine_-2 receptor antagonists (H₂RAs) (adjusted OR = 1.22, 95% CI: 1.09-1.36, I² = 0.0%). In the randomized controlled trials, use of H₂RAs was associated with an elevated risk of hospital-acquired pneumonia (relative risk 1.22, 95% CI: 1.01-1.48, I² = 30.6%). Another meta-analysis of 11 studies published between 1997 and 2011 found that PPIs, which reduce stomach acid production, were associated with increased risk of fracture. The pooled OR for fracture was 1.29 (95% CI: 1.18-1.41) with use of PPIs and 1.10 (95% CI: 0.99-1.23) with use of H₂RAs, when compared with non-use of the respective medications. Long-term use of PPIs increased the risk of any fracture (adjusted OR = 1.30, 95% CI: 1.15-1.48) and of hip fracture risk (adjusted OR = 1.34, 95% CI: 1.09-1.66), whereas long-term H₂RA use was not significantly associated with fracture risk. Clinicians should carefully consider when deciding to prescribe acid-suppressive drugs, especially for patients who are already at risk for pneumonia and fracture. Since it is unnecessary to achieve an achlorhydric state in order to resolve symptoms, we recommend using the only minimum effective dose of drug required to achieve the desired therapeutic goals.

Challenges in estimating reproducibility of imaging modalities

Estimating reproducibility is often wrongly thought of as basic science. Although it has a significant clinical relevance, its importance is underestimated. It was Alexander Pope in 1732 who was first to understand the value of reproducibility, with his famous comment “Who shall decide when doctors disagree?”. Pope’s question concerns the medical doctors’ opinion on a patient’s status, which from a statistical point of view may be considered a categorical variable. However, the same question may be posed for continuous quantitative variables. Reproducibility is complementary to variability: the larger the variability, the lower the reproducibility, and vice versa. Thus, we can think at them as interchangeable, even thought statistical methods have been developed for the estimation of variability. The question now is “Why do we need to know the reproducibility of measurements? ”. The most important and simplest answer is that we need to know how reliable a measured value or a subjective judgment is before taking clinical decisions based on this measurement/judgment. Integrating this knowledge in clinical practice is a key aspect of evidence-based medicine.