http://www.mdpi.com/journal/diagnostics Latest open access articles published in Diagnostics at http://www.mdpi.com/journal/diagnostics http://www.mdpi.com/2075-4418/3/2/283 Since the discovery of the presence of fetal DNA in maternal blood, non-invasive fetal sex determination has been the test most widely translated into clinical practice. To date there is no agreement between the different laboratories performing such tests in relation to which is the best protocol. As a consequence there are almost as many protocols as laboratories offering the service, using different methodologies and thus obtaining different diagnostic accuracies. By the end of 2007, after a validation study performed in 316 maternal samples collected between the 5th and 12th week of gestation, the fetal sex determination was incorporated into clinical practice in our Service. The test is performed in the first trimester of pregnancy, and it is offered as part of the genetic counseling process for couples at risk of X-linked disorders. As a general rule and in order to avoid misdiagnosis, two samples at different gestational ages are tested per patient. The analysis is performed by the study of the SRY gene by RT-PCR. Two hundred and twenty six pregnancies have been tested so far in these 5 years. Neither false positives nor false negatives diagnoses have been registered, thus giving a diagnostic accuracy of 100%. Diagnostics 2013-05-15 3 2 Article 10.3390/diagnostics3020283 283 290 2075-4418 2013-05-15 doi: 10.3390/diagnostics3020283 Sara Perlado-Marina Ana Bustamante-Aragones Laura Horcajada Maria Trujillo-Tiebas Isabel Lorda-Sanchez Marta Ruiz Ramos Javier Plaza Marta Rodriguez de Alba http://www.mdpi.com/2075-4418/3/2/271 The purpose of this study was to evaluate the performance of a semiautomatic segmentation method for the anatomical and functional assessment of both ventricles from cardiac cine magnetic resonance (MR) examinations, reducing user interaction to a “mouse-click”. Fifty-two patients with cardiovascular diseases were examined using a 1.5-T MR imaging unit. Several parameters of both ventricles, such as end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (EF), were quantified by an experienced operator using the conventional method based on manually-defined contours, as the standard of reference; and a novel semiautomatic segmentation method based on edge detection, iterative thresholding and region growing techniques, for evaluation purposes. No statistically significant differences were found between the two measurement values obtained for each parameter (p > 0.05). Correlation to estimate right ventricular function was good (r > 0.8) and turned out to be excellent (r > 0.9) for the left ventricle (LV). Bland-Altman plots revealed acceptable limits of agreement between the two methods (95%). Our study findings indicate that the proposed technique allows a fast and accurate assessment of both ventricles. However, further improvements are needed to equal results achieved for the right ventricle (RV) using the conventional methodology. Diagnostics 2013-04-03 3 2 Article 10.3390/diagnostics3020271 271 282 2075-4418 2013-04-03 doi: 10.3390/diagnostics3020271 Miguel Souto Lambert Masip Miguel Couto Jorge Suárez-Cuenca Amparo Martínez Pablo Tahoces Jose Carreira Pierre Croisille http://www.mdpi.com/2075-4418/3/2/261 Computed Tomography (CT) Perfusion is an evolving method to visualize perfusion in organs and tissue. With the introduction of multidetector CT scanners, it is now possible to cover up to 16 cm in one rotation, and thereby making it possible to scan entire organs such as the liver with a fixed table position. Advances in reconstruction algorithms make it possible to reduce the radiation dose for each examination to acceptable levels. Regarding abdominal imaging, CT perfusion is still considered a research tool, but several studies have proven it as a reliable non-invasive technique for assessment of vascularity. CT perfusion has also been used for tumor characterization, staging of disease, response evaluation of newer drugs targeted towards angiogenesis and as a method for early detection of recurrence after radiation and embolization. There are several software solutions available on the market today based on different perfusion algorithms. However, there is no consensus on which protocol and algorithm to use for specific organs. In this article, the authors give an introduction to CT perfusion in abdominal imaging introducing technical aspects for calculation of perfusion parameters, and considerations on patient preparation. This article also contains clinical cases to illustrate the use of CT perfusion in abdominal imaging. Diagnostics 2013-04-03 3 2 Article 10.3390/diagnostics3020261 261 270 2075-4418 2013-04-03 doi: 10.3390/diagnostics3020261 Martin Hansen Rikke Norling Carsten Lauridsen Eva Fallentin Lene Bæksgaard Klaus Kofoed Lars Svendsen Michael Nielsen http://www.mdpi.com/2075-4418/3/2/244 This paper describes a rapid, high-throughput flow-through membrane immunoassay (FMIA) platform. A nitrocellulose membrane was spotted in an array format with multiple capture and control reagents for each sample detection area, and assay steps were carried out by sequential aspiration of sample and reagents through each detection area using a 96-well vacuum manifold. The FMIA provides an alternate assay format with several advantages over ELISA. The high surface area of the membrane permits high label concentration using gold labels, and the small pores and vacuum control provide rapid diffusion to reduce total assay time to ~30 min. All reagents used in the FMIA are compatible with dry storage without refrigeration. The results appear as colored spots on the membrane that can be quantified using a flatbed scanner. We demonstrate the platform for detection of IgM specific to lipopolysaccharides (LPS) derived from Salmonella Typhi. The FMIA format provides analytical results comparable to ELISA in less time, provides integrated assay controls, and allows compensation for specimen-to-specimen variability in background, which is a particular challenge for IgM assays. Diagnostics 2013-04-02 3 2 Article 10.3390/diagnostics3020244 244 260 2075-4418 2013-04-02 doi: 10.3390/diagnostics3020244 Sujatha Ramachandran Mitra Singhal Katherine McKenzie Jennifer Osborn Amit Arjyal Sabina Dongol Stephen Baker Buddha Basnyat Jeremy Farrar Christiane Dolecek Gonzalo Domingo Paul Yager Barry Lutz http://www.mdpi.com/2075-4418/3/2/232 Background: Coronary artery involvement is seen in approximately 15–20% of children with Kawasaki disease. There is conflicting literature regarding the clinical and laboratory findings associated with coronary artery involvement. In this retrospective study, we attempt identification of predictive factors for coronary artery involvement at our institute and review the existing literature. Methods and results: A review of 203 patients (65% males) with Kawasaki disease was performed, of whom 33 (16.3%) had coronary artery involvement. High erythrocyte sedimentation rate, high platelet count, low hematocrit, low albumin levels, and refractory Kawasaki disease showed significant association with coronary artery involvement. High erythrocyte sedimentation rate and refractory Kawasaki disease were found to be independent predictors of coronary artery involvement. Review of literature suggested a wide range of coronary involvement (<5% to >60%), and highly conflicting clinical and laboratory associations. Conclusion: It remains difficult to accurately determine risk of coronary artery involvement, although some laboratory markers may provide information that is helpful for parental counseling and clinical follow up. Future identification of novel biomarkers and host predispositions may further our understanding of coronary artery risks and help personalize therapy for Kawasaki disease. Diagnostics 2013-03-26 3 2 Review 10.3390/diagnostics3020232 232 243 2075-4418 2013-03-26 doi: 10.3390/diagnostics3020232 Sunil Ghelani Neha Kwatra Christopher Spurney http://www.mdpi.com/2075-4418/3/2/222 The investigation of respiratory infections by molecular techniques provides important information about the epidemiology of respiratory disease, especially during the post-vaccination era. The objective of the present study was the detection of bacterial pathogens directly in clinical samples from patients with upper and lower respiratory tract infections using multiplex polymerase chain reaction (PCR) assays developed in our laboratory. Clinical samples taken over a three-year period (2007–2009) and obtained from 349 patients (adults (n = 66); children (n = 283)) with signs and symptoms of certain upper or lower respiratory tract infections, consisted of: bronchoalveolar lavages (BAL, n = 83), pleural fluids (n = 29), and middle-ear aspirates (n = 237). Overall, 212 samples (61%) were confirmed by culture and/or PCR. Among the positive samples, Streptococcus pneumoniae (mainly serotype 3) was predominant (104/212; 49.0%), followed by non-typable Haemophilus influenzae (NTHi) 59/212; 27.8%) and Streptococcus pyogenes (47/212; 22%). Haemophilus influenzae type b was detected in only three samples. The underlying microbiology of respiratory infections is gradually changing in response to various selective pressures, such as vaccine use and antibiotic consumption. The application of multiplex PCR (mPCR) assays is particularly useful since it successfully identified the microorganisms implicated in acute otitis media or lower respiratory tract infections in nearly 75% of patients with a positive result compared to conventional cultures. Non-culture identification of the implicated pneumococcal serotypes is also an important issue for monitoring pneumococcal infections in the era of conjugate pneumococcal vaccines. Diagnostics 2013-03-26 3 2 Article 10.3390/diagnostics3020222 222 231 2075-4418 2013-03-26 doi: 10.3390/diagnostics3020222 Athanasia Xirogianni Maria Tsolia Aliki Voyiatzi Maria Sioumala Antonia Makri Athina Argyropoulou Olga Paniara Panayotis Markoulatos Jenny Kourea-Kremastinou Georgina Tzanakaki http://www.mdpi.com/2075-4418/3/2/210 Parkinson’s disease is the second most prevalent disease of the brain. It is characterized by midbrain dopaminergic neuronal degeneration accompanied by Lewy bodies, intra-cytoplasmic neuronal inclusions that consist mainly of alpha-synuclein. The cardinal motor features are muscular rigidity, bradykinesia, and resting tremor and, in advanced cases, postural instability. Symptoms are relieved by dopamine replacement therapy, but progress slowly. Clinical diagnosis is made according to medical history, neurological examinations and the response to anti-Parkinsonian drugs. There are no laboratory tests for diagnosis of the disease; however, for development of disease-modifying treatment, early diagnosis by objective laboratory test is required. Recently, postsynaptic sympathetic norepinephrine nerve terminals were found to be degenerated as well as mesencephalic dopaminergic neurons. Cardiac norepinephrine denervation can be seen by meta-iodine-benzyl guanidine scintigraphy, and may be a reliable diagnostic marker. Degeneration of norepinephrinergic and dopaminergic neurons suggests that catecholamines may play a central role in the neurodegeneration in Parkinson’s disease. Recently several studies showed that alpha-synuclein aggregates in cells exposed to dopamine. Here, we review findings relating to an early diagnostic marker for detecting degeneration of the peripheral sympathetic nerves, and propose the hypothesis that catecholamines cause alpha-synuclein to aggregate and play an important role in disease pathogenesis. Diagnostics 2013-03-25 3 2 Review 10.3390/diagnostics3020210 210 221 2075-4418 2013-03-25 doi: 10.3390/diagnostics3020210 Hideyuki Sawada Tomoko Oeda Kenji Yamamoto http://www.mdpi.com/2075-4418/3/1/192 The accuracy of diagnostic tests with binary end-points is most frequently measured by sensitivity and specificity. However, from the clinical perspective, the main purpose of a diagnostic agent is to assess the probability of a patient actually being diseased and hence predictive values are more suitable here. As predictive values depend on the pre-test probability of disease, we provide a method to take risk factors influencing the patient’s prior probability of disease into account, when calculating predictive values. Furthermore, approaches to assess confidence intervals and a methodology to compare predictive values by statistical tests are presented. Hereby the methods can be used to analyze predictive values of factorial diagnostic trials, such as multi-modality, multi-reader-trials. We further performed a simulation study assessing length and coverage probability for different types of confidence intervals, and we present the R-Package facROC that can be used to analyze predictive values in factorial diagnostic trials in particular. The methods are applied to a study evaluating CT-angiography as a noninvasive alternative to coronary angiography for diagnosing coronary artery disease. Hereby the patients’ symptoms are considered as risk factors influencing the respective predictive values. Diagnostics 2013-03-15 3 1 Article 10.3390/diagnostics3010192 192 209 2075-4418 2013-03-15 doi: 10.3390/diagnostics3010192 Katharina Lange Edgar Brunner http://www.mdpi.com/2075-4418/3/1/170 Hepatocellular carcinoma (HCC) is the most common form of liver cancer and is the third leading cause of cancer-related deaths worldwide. Treatment options for HCC are very limited, as it is often diagnosed at a late stage. Recent studies have demonstrated that microRNAs (miRNAs), a class of non-coding RNAs, are aberrantly expressed in HCC. Some of these were shown to be functionally involved in carcinogenesis and tumor progression, suggesting that miRNAs can serve as novel molecular targets for HCC therapy. Several promising studies have recently demonstrated the therapeutic potential of miRNAs in animal models and in reducing the viral load in hepatitis C patients. In this review, these advances and strategies for modulating miRNAs for in vivo therapeutic delivery and replacement therapy are discussed. Diagnostics 2013-03-15 3 1 Review 10.3390/diagnostics3010170 170 191 2075-4418 2013-03-15 doi: 10.3390/diagnostics3010170 Rajagopal Aravalli http://www.mdpi.com/2075-4418/3/1/155 We report a disposable and highly effective polymeric microfluidic viral sample concentration device capable of increasing the concentration of virus in a human nasopharyngeal specimen more than one order of magnitude in less than 30 min without the use of a centrifuge. The device is fabricated using 3D maskless xurography method using commercially available polymeric materials, which require no cleanroom operations. The disposable components can be fabricated and assembled in five minutes. The device can concentrate a few milliliters (mL) of influenza virus in solution from tissue culture or clinical nasopharyngeal swab specimens, via reduction of the fluid volume, to tens of microliters (mL). The performance of the device was evaluated by nucleic acid extraction from the concentrated samples, followed by a real-time quantitative polymerase chain reaction (qRT-PCR). The viral RNA concentration in each sample was increased on average over 10-fold for both cultured and patient specimens compared to the starting samples, with recovery efficiencies above 60% for all input concentrations. Highly concentrated samples in small fluid volumes can increase the downstream process speed of on-chip nucleic acid extraction, and result in improvements in the sensitivity of many diagnostic platforms that interrogate small sample volumes. Diagnostics 2013-02-28 3 1 Article 10.3390/diagnostics3010155 155 169 2075-4418 2013-02-28 doi: 10.3390/diagnostics3010155 Jane Zhang Madhumita Mahalanabis Lena Liu Jessie Chang Nira Pollock Catherine Klapperich http://www.mdpi.com/2075-4418/3/1/126 During the last two decades, the manufacturing techniques of microfluidics-based devices have been phenomenally advanced, offering unlimited potential for bio-medical technologies. However, the direct applications of these technologies toward diagnostics and therapeutics are still far from maturity. The present challenges lay at the interfaces between the engineering systems and the biocomplex systems. A precisely designed engineering system with narrow dynamic range is hard to seamlessly integrate with the adaptive biological system in order to achieve the design goals. These differences remain as the roadblock between two fundamentally non-compatible systems. This paper will not extensively review the existing microfluidic sensors and actuators; rather, we will discuss the sources of the gaps for integration. We will also introduce system interface technologies for bridging the differences to lead toward paradigm shifts in diagnostics and therapeutics. Diagnostics 2013-02-27 3 1 Review 10.3390/diagnostics3010126 126 154 2075-4418 2013-02-27 doi: 10.3390/diagnostics3010126 Hann Wang Aleidy Silva Chih-Ming Ho http://www.mdpi.com/2075-4418/3/1/117 Strain elastography (SE), which estimates tissue strain, is an adjunct to the conventional ultrasound B-mode examination. We present a short introduction to SE and its clinical use. Furthermore, we present an overview of the 10 largest studies performed on the diagnostic accuracy of SE in breast cancer diagnostics. Eight of 10 studies presented data for both SE and B-mode imaging. Seven studies showed better specificity and accuracy for SE than for B-mode imaging in breast cancer diagnosis. Four studies showed an increase in specificity and accuracy when combining B-mode imaging with SE. The ways of combining B-mode imaging with SE in the diagnosis of breast cancer differed between the five studies. We believe that further studies are needed to establish an optimal algorithm for the combination of B-mode ultrasound and SE in breast cancer. Diagnostics 2013-02-25 3 1 Review 10.3390/diagnostics3010117 117 125 2075-4418 2013-02-25 doi: 10.3390/diagnostics3010117 Jonathan Carlsen Caroline Ewertsen Lars Lönn Michael Nielsen http://www.mdpi.com/2075-4418/3/1/105 Development of new diagnostic platforms that incorporate lab-on-a-chip technologies for portable assays is driving the need for rapid, simple, low cost methods to prepare samples for downstream processing or detection. An important component of the sample preparation process is cell lysis. In this work, a simple microfluidic thermal lysis device is used to quickly release intracellular nucleic acids and proteins without the need for additional reagents or beads used in traditional chemical or mechanical methods (e.g., chaotropic salts or bead beating). On-chip lysis is demonstrated in a multi-turn serpentine microchannel with external temperature control via an attached resistive heater. Lysis was confirmed for Escherichia coli by fluorescent viability assay, release of ATP measured with bioluminescent assay, release of DNA measured by fluorometry and qPCR, as well as bacterial culture. Results comparable to standard lysis techniques were achievable at temperatures greater than 65 °C and heating durations between 1 and 60 s. Diagnostics 2013-01-17 3 1 Communication 10.3390/diagnostics3010105 105 116 2075-4418 2013-01-17 doi: 10.3390/diagnostics3010105 Michelle Packard Elizabeth Wheeler Evangelyn Alocilja Maxim Shusteff http://www.mdpi.com/2075-4418/3/1/84 MicroRNAs (miRNAs) are small non-coding RNA molecules, which in recent years have emerged to have enormous potential as biomarkers. Recently, there have been significant developments in understanding miRNA biogenesis, their regulatory mechanisms and role in disease process, and their potential as effective therapies. The identification of miRNAs as biomarkers provides possibilities for development of less or non-invasive and more specific methods for monitoring tumor growth and progression. This review summarizes the recent developments in methods to detect and quantitate miRNAs in body fluids and their applications as biomarkers in cancers. The prospect of miRNAs as potential diagnostic and prognostic biomarkers with clinical applications is significant as more evidence points to their central role in cancer pathobiology. Diagnostics 2013-01-16 3 1 Review 10.3390/diagnostics3010084 84 104 2075-4418 2013-01-16 doi: 10.3390/diagnostics3010084 Kamini Sundarbose Reena Kartha Subbaya Subramanian http://www.mdpi.com/2075-4418/3/1/68 An analytical TD-GC-MS method was developed and used for the assessment of volatile organic compounds (VOCs) released from the blood plasma of dogs with/without cancer. VOCs released from 40 samples of diseased blood and 10 control samples were compared in order to examine the difference between both sample groups that were showing qualitatively similar results independent from the disease’s presence. However, mild disturbances in the spectra of dogs with cancer in comparison with the control group were observed, and six peaks (tentatively identified by comparison with mass spectral library as hexanal, octanal, toluene, 2-butanone, 1-octen-3-ol and pyrrole) revealed statistically significant differences between both sample groups, thereby suggesting that these compounds are potential biomarkers that can be used for cancer diagnosis based on the blood plasma TD-GC-MS analysis. Statistical comparison with the application of principal component analysis (PCA) provided accurate discrimination between the cancer and control groups, thus demonstrating stronger biochemical perturbations in blood plasma when cancer is present. Diagnostics 2013-01-16 3 1 Article 10.3390/diagnostics3010068 68 83 2075-4418 2013-01-16 doi: 10.3390/diagnostics3010068 Roman Selyanchyn Takuma Nozoe Hidetaka Matsui Tsuyoshi Kadosawa Seung-Woo Lee http://www.mdpi.com/2075-4418/3/1/33 This review presents an overview of the different techniques developed over the last decade to regulate the temperature within microfluidic systems. A variety of different approaches has been adopted, from external heating sources to Joule heating, microwaves or the use of lasers to cite just a few examples. The scope of the technical solutions developed to date is impressive and encompasses for instance temperature ramp rates ranging from 0.1 to 2,000 °C/s leading to homogeneous temperatures from −3 °C to 120 °C, and constant gradients from 6 to 40 °C/mm with a fair degree of accuracy. We also examine some recent strategies developed for applications such as digital microfluidics, where integration of a heating source to generate a temperature gradient offers control of a key parameter, without necessarily requiring great accuracy. Conversely, Temperature Gradient Focusing requires high accuracy in order to control both the concentration and separation of charged species. In addition, the Polymerase Chain Reaction requires both accuracy (homogeneous temperature) and integration to carry out demanding heating cycles. The spectrum of applications requiring temperature regulation is growing rapidly with increasingly important implications for the physical, chemical and biotechnological sectors, depending on the relevant heating technique. Diagnostics 2013-01-15 3 1 Review 10.3390/diagnostics3010033 33 67 2075-4418 2013-01-15 doi: 10.3390/diagnostics3010033 Vincent Miralles Axel Huerre Florent Malloggi Marie-Caroline Jullien http://www.mdpi.com/2075-4418/3/1/13 Lung cancer is the leading cause of cancer-related death in the United States. Here, we evaluated the potential clinical utility of soluble human epidermal growth factor receptor 2 (sHER2) for the risk assessment, screening, and diagnosis of non-small cell lung cancer (NSCLC) using an unmatched case-control study design. Serum sHER2 concentrations were measured by immunoassay in 244 primary NSCLC cases and 218 healthy controls. Wilcoxon rank-sum tests, logistic regression models, and receiver operating characteristic plots were used to assess whether sHER2 is associated with lung cancer. Median serum sHER2 concentrations are higher in patients with adenocarcinoma than squamous cell carcinoma regardless of gender, and sHER2 is a weak, independent biomarker of adenocarcinoma, but not of squamous cell carcinoma, adjusted for age and gender. The age-adjusted relative risk (odds) of adenocarcinoma is 3.95 (95% CI: 1.22, 12.81) and 7.93 (95% CI: 2.26, 27.82) greater for women and men with high sHER2 concentrations (≥6.60 ng/mL) vs. low sHER2 concentrations (≤1.85 ng/mL), respectively. When adjusted for each other, sHER2, age, and gender discern healthy controls from patients with primary adenocarcinomas of the lung with 85.9% accuracy. We conclude that even though serum sHER2 is not a strong, stand-alone discriminatory biomarker of adenocarcinoma, sHER2 may be a useful, independent covariate in multivariate risk assessment, screening, and diagnostic models of lung cancer. Diagnostics 2013-01-14 3 1 Article 10.3390/diagnostics3010013 13 32 2075-4418 2013-01-14 doi: 10.3390/diagnostics3010013 Abby Cosentino-Boehm Jacqueline Lafky Tammy Greenwood Kimberly Kimbler Marites Buenafe Yuxia Wang Adam Branscum Ping Yang Nita Maihle Andre Baron http://www.mdpi.com/2075-4418/3/1/1 Making a diagnosis of Kawasaki disease with certainty may be challenging, especially since the recognition of cases with incomplete diagnostic criteria and its consequences. In order to build the diagnostic case in daily practice, clinicians rely on clinical criteria established over four decades ago, aided by non specific laboratory tests, and above all inspired by experience. We have recently studied the diagnostic value of N-terminal pro B-type natriuretic peptide to improve the diagnostic certainty of cases with complete or incomplete clinical criteria. Our working hypothesis was based on the fact that myocarditis is present in nearly all Kawasaki disease patients supported by histology data. In this paper, we review these facts and the myocardial perspective from the diagnostic and the mechanistic standpoints. Diagnostics 2013-01-10 3 1 Review 10.3390/diagnostics3010001 1 12 2075-4418 2013-01-10 doi: 10.3390/diagnostics3010001 Nagib Dahdah Anne Fournier http://www.mdpi.com/2075-4418/2/4/97 In this work, a novel optofluidic sensor principle is employed for a non-invasive and label-free characterization of lactose containing liquid samples. Especially for medicine and food industry, a simple, fast and accurate determination of the amount of lactose in various products is highly desirable. The presented system exploits the impact of dissolved molecules on the refractive index for sample characterization. On the optofluidic chip, a microfluidic channel filled with the analyte is hit by slightly diverging laser light. The center incident angle of the beam on-chip is set close to the critical angle for total internal reflection. Both the reflected and the transmitted light signals are recorded at the solid-liquid interface. The ratio of those two signals is then used as representative value for the analyte. Using this principle, lactose containing samples were differentiated based on their concentrations at a step size of 10 mmol/L. The use of the signals ratio instead of a single signal approach improves the stability of the system significantly, allowing for higher resolutions to be achieved. Furthermore, the fabrication of the devices in PDMS ensures biocompatibility and provides low absorbance of light in the visible range. Diagnostics 2012-12-06 2 4 Article 10.3390/diagnostics2040097 97 106 2075-4418 2012-12-06 doi: 10.3390/diagnostics2040097 Emanuel Weber Franz Keplinger Michael Vellekoop http://www.mdpi.com/2075-4418/2/4/83 Cell-based biosensors provide new horizons for medical diagnostics by adopting complex recognition elements such as mammalian cells in microfluidic devices that are simple, cost efficient and disposable. This combination renders possible a new range of applications in the fields of diagnostics and personalized medicine. The review looks at the most recent developments in cell-based biosensing microfluidic systems with electrical and electrochemical transduction, and relevance to medical diagnostics. Diagnostics 2012-12-06 2 4 Review 10.3390/diagnostics2040083 83 96 2075-4418 2012-12-06 doi: 10.3390/diagnostics2040083 Katrine Kiilerich-Pedersen Noemi Rozlosnik http://www.mdpi.com/2075-4418/2/4/72 SU-8 epoxy-based negative photoresist has been extensively employed as a structural material for fabrication of numerous biological microelectro-mechanical systems (Bio-MEMS) or lab-on-a-chip (LOC) devices. However, SU-8 has a high autofluorescence level that limits sensitivity of microdevices that use fluorescence as the predominant detection workhorse. Here, we show that deposition of a thin gold nanoparticles layer onto the SU-8 surface significantly reduces the autofluorescence of the coated SU-8 surface by as much as 81% compared to bare SU-8. Furthermore, DNA probes can easily be immobilized on the Au surface with high thermal stability. These improvements enabled sensitive DNA detection by simple DNA hybridization down to 1 nM (a two orders of magnitude improvement) or by solid-phase PCR with sub-picomolar sensitivity. The approach is simple and easy to perform, making it suitable for various Bio-MEMs and LOC devices that use SU-8 as a structural material. Diagnostics 2012-11-29 2 4 Article 10.3390/diagnostics2040072 72 82 2075-4418 2012-11-29 doi: 10.3390/diagnostics2040072 Cuong Cao Sam Birtwell Jonas Høgberg Hywel Morgan Anders Wolff Dang Bang http://www.mdpi.com/2075-4418/2/4/57 Objective: To analyze trends in screening and invasive prenatal diagnosis of chromosome abnormalities (CA) over a 13-year period and correlate them to changes in the national prenatal screening policy. Methods: We retrospectively reviewed Down syndrome (DS) screening tests and fetal karyotypes obtained by prenatal invasive testing (IT) in our fetal medicine unit between January 1999 and December 2011. Results: A total of 24,226 prenatal screening tests for DS and 11,045 invasive procedures have been analyzed. Over a 13-year period, utilization of non-invasive screening methods has significantly increased from 57% to 89%. The percentage of invasive procedures has declined from 49% to 12%, although the percentage of IT performed for maternal anxiety has increased from 22% to 55%. The percentage of detected CA increased from 2.5% to 5.9%. Overall, 31 invasive procedures are needed to diagnose 1 abnormal case, being 23 procedures in medical indications and 241 procedures in non-medical indications. Conclusions: Our experience on screening and invasive prenatal diagnostic practice shows a decrease of the number of IT, with a parallel decline in medical indications. There is an increasing efficiency of prenatal screening program to detect CA. Despite the increasing screening policies, our population shows a growing request for prenatal IT. The a priori low risk population shows a not negligible residual risk for relevant CA. This observation challenges the current prenatal screening strategy focused on DS; showing that the residual risk is higher than the current cut-off used to indicate an invasive technique. Diagnostics 2012-11-19 2 4 Article 10.3390/diagnostics2040057 57 71 2075-4418 2012-11-19 doi: 10.3390/diagnostics2040057 Carmen Comas Mónica Echevarria María Ángeles Rodríguez Ignacio Rodríguez Bernat Serra Vincenzo Cirigliano http://www.mdpi.com/2075-4418/2/4/52 Positional vertigo is a common neurologic emergency and mostly the etiology is peripheral. However, central diseases may mimic peripheral positional vertigo at their initial presentation. We here describe the results of a visual suppression test in six patients with spinocerebellar ataxia type 6 (SCA6), a central positional vertigo, and nine patients with benign paroxysmal positional vertigo (BPPV), the major peripheral positional vertigo. As a result, the visual suppression value of both diseases differed significantly; e.g., 22.5% in SCA6 and 64.3% in BPPV (p < 0.001). There was a positive correlation between the visual suppression value and disease duration, cerebellar atrophy, and CAG repeat length of SCA6 but they were not statistically significant. In conclusion, the present study showed for the first time that visual suppression is impaired in SCA6, a central positional vertigo, but preserved in BPPV, the major peripheral positional vertigo, by directly comparing both groups. The abnormality in the SCA6 group presumably reflects dysfunction in the central visual fixation pathway at the cerebellar flocculus and nodulus. This simple test might aid differential diagnosis of peripheral and central positional vertigo at the earlier stage of disease. Diagnostics 2012-10-11 2 4 Communication 10.3390/diagnostics2040052 52 56 2075-4418 2012-10-11 doi: 10.3390/diagnostics2040052 Masahiko Kishi Ryuji Sakakibara Tomoe Yoshida Masahiko Yamamoto Mitsuya Suzuki Manabu Kataoka Yohei Tsuyusaki Akihiko Tateno Fuyuki Tateno http://www.mdpi.com/2075-4418/2/4/42 The purpose of this study was to investigate whether a correction for annihilation photon attenuation in small objects such as mice is necessary. The attenuation recovery for specific organs and subcutaneous tumors was investigated. A comparison between different attenuation correction methods was performed. Methods: Ten NMRI nude mice with subcutaneous implantation of human breast cancer cells (MCF-7) were scanned consecutively in small animal PET and CT scanners (MicroPETTM Focus 120 and ImTek’s MicroCATTM II). CT-based AC, PET-based AC and uniform AC methods were compared. Results: The activity concentration in the same organ with and without AC revealed an overall attenuation recovery of 9–21% for MAP reconstructed images, i.e., SUV without AC could underestimate the true activity at this level. For subcutaneous tumors, the attenuation was 13 ± 4% (9–17%), for kidneys 20 ± 1% (19–21%), and for bladder 18 ± 3% (15–21%). The FBP reconstructed images showed almost the same attenuation levels as the MAP reconstructed images for all organs. Conclusions: The annihilation photons are suffering attenuation even in small subjects. Both PET-based and CT-based are adequate as AC methods. The amplitude of the AC recovery could be overestimated using the uniform map. Therefore, application of a global attenuation factor on PET data might not be accurate for attenuation correction. Diagnostics 2012-10-09 2 4 Article 10.3390/diagnostics2040042 42 51 2075-4418 2012-10-09 doi: 10.3390/diagnostics2040042 Henrik H. El Ali Rasmus Poul Bodholdt Jesper Tranekjær Jørgensen Rebecca Myschetzky Andreas Kjaer http://www.mdpi.com/2075-4418/2/3/34 Image fusion involving real-time ultrasound (US) is a technique where previously recorded computed tomography (CT) or magnetic resonance images (MRI) are reformatted in a projection to fit the real-time US images after an initial co-registration. The co-registration aligns the images by means of common planes or points. We evaluated the accuracy of the alignment when varying parameters as patient position, respiratory phase and distance from the co-registration points/planes. We performed a total of 80 co-registrations and obtained the highest accuracy when the respiratory phase for the co-registration procedure was the same as when the CT or MRI was obtained. Furthermore, choosing co-registration points/planes close to the area of interest also improved the accuracy. With all settings optimized a mean error of 3.2 mm was obtained. We conclude that image fusion involving real-time US is an accurate method for abdominal examinations and that the accuracy is influenced by various adjustable factors that should be kept in mind. Diagnostics 2012-08-27 2 3 Article 10.3390/diagnostics2030034 34 41 2075-4418 2012-08-27 doi: 10.3390/diagnostics2030034 Caroline Ewertsen Kristoffer L. Hansen Birthe M. Henriksen Michael B. Nielsen http://www.mdpi.com/2075-4418/2/3/23 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) alone, and in combination with N-hydroxysuccinimide (NHS) or sulfoNHS were employed for crosslinking anti-human fetuin A (HFA) antibodies on 3-aminopropyltriethoxysilane (APTES)-functionalized surface plasmon resonance (SPR) gold chip and 96-well microtiter plate. The SPR immunoassay and sandwich enzyme linked immunosorbent immunoassay (ELISA) for HFA clearly demonstrated that EDC crosslinks anti-HFA antibodies to APTES-functionalized bioanalytical platforms more efficiently than EDC/NHS and EDC/sulfoNHS at a normal pH of 7.4. Similar results were obtained by sandwich ELISAs for human Lipocalin-2 and human albumin, and direct ELISA for horseradish peroxidase. The more efficient crosslinking of antibodies by EDC to the APTES-functionalized platforms increased the cost-effectiveness and analytical performance of our immunoassays. This study will be of wide interest to researchers developing immunoassays on APTES-functionalized platforms that are being widely used in biomedical diagnostics, biosensors, lab-on-a-chip and point-of-care-devices. It stresses a critical need of an intensive investigation into the mechanisms of EDC-based amine-carboxyl coupling under various experimental conditions. Diagnostics 2012-08-27 2 3 Article 10.3390/diagnostics2030023 23 33 2075-4418 2012-08-27 doi: 10.3390/diagnostics2030023 Sandeep Kumar Vashist http://www.mdpi.com/2075-4418/2/2/10 Objective: A thyroid rat model combining functional and anatomical information would be of great benefit for better modeling of thyroid physiology and for absorbed dose calculations. Our aim was to show that 124I-PET and CT small animal imaging are useful as a combined model for studying thyroid physiology and dose calculation. Methods: Seven rats were subjects for multiple thyroid 124I-imaging and CT-scans. S-values [mGy/MBqs] for different thyroid sizes were simulated. A phantom with spheres was designed for validation of performances of the small animal PET and CT imaging systems. Results: Small animal image-based measurements of the activity amount and the volumes of the spheres with a priori known volumes showed a good agreement with their corresponding actual volumes. The CT scans of the rats showed thyroid volumes from 34–70 mL. Conclusions: The wide span in volumes of thyroid glands indicates the importance of using an accurate volume-measuring technique such as the small animal CT. The small animal PET system was on the other hand able to accurately estimate the activity concentration in the thyroid volumes. We conclude that the combination of the PET and CT image information is essential for quantitative thyroid imaging and accurate thyroid absorbed dose calculation. Diagnostics 2012-06-05 2 2 Article 10.3390/diagnostics2020010 10 22 2075-4418 2012-06-05 doi: 10.3390/diagnostics2020010 Henrik H. El-Ali Martin Eckerwall Dorthe Skovgaard Erik Larsson Sven-Erik Strand Andreas Kjaer http://www.mdpi.com/2075-4418/2/2/2 Objective: To evaluate the intra-/interobserver agreement of the visual interpretation of contrast-enhanced ultrasound (CEUS) of pancreatic head lesions and its concordance with the histological test results. Material and Methods: Two observers (A + B) evaluated by simple visual interpretation 40 consecutive CEUS examinations of pancreatic head lesions and one of the observers evaluated the examinations twice (A1 + A2). The examinations were evaluated according to the criteria outlined in EFSUMB guidelines. The two experienced observers were blinded to histological evidence and clinical information of tumor type and to each other’s results. Results: The kappa value for the intraobserver evaluation between observer A1 and A2 was 0.89, equating to almost perfect agreement. The kappa value for the interobserver evaluation between observer A1 and B was 0.76 and between observer A2 and B it was 0.75, both equating to substantial agreement. Evaluation of the visual interpretation compared to the histological test result showed a positive predictive value for A1, A2 and B versus biopsy of 97%, 94% and 90% respectively and an accuracy of 83%, 88% and 73% respectively. Conclusions: Visual interpretation for assessment of contrast enhancement of pancreatic head lesions seemed to be an accurate method with reproducible results and good concordance with the histological test results. Diagnostics 2012-04-20 2 2 Article 10.3390/diagnostics2020002 2 9 2075-4418 2012-04-20 doi: 10.3390/diagnostics2020002 Hanne Sønder Grossjohann Caroline Ewertsen Lars Bo Svendsen Michael Bachmann Nielsen http://www.mdpi.com/2075-4418/2/1/1 The field of microfluidics has seen breath-taking progress since its beginnings in the 1980s and early 1990s. While much of the initial work was a by-product of mainstream micro-electro-mechanical systems (MEMS) and silicon based fabrication schemes, soon a specialized research field developed. Over the last decade a strong, highly interdisciplinary microfluidics community emerged with roots in classical silicon microfabrication as well as chemistry, physics, biotechnology, medicine and various engineering disciplines. [...] Diagnostics 2012-03-20 2 1 Announcement 10.3390/diagnostics2010001 1 1 2075-4418 2012-03-20 doi: 10.3390/diagnostics2010001 Jens Ducrée http://www.mdpi.com/2075-4418/1/1/53 This presentation will emphasize the estimation of the combined accuracy of two or more tests when verification bias is present. Verification bias occurs when some of the subjects are not subject to the gold standard. The approach is Bayesian where the estimation of test accuracy is based on the posterior distribution of the relevant parameter. Accuracy of two combined binary tests is estimated employing either “believe the positive” or “believe the negative” rule, then the true and false positive fractions for each rule are computed for two tests. In order to perform the analysis, the missing at random assumption is imposed, and an interesting example is provided by estimating the combined accuracy of CT and MRI to diagnose lung cancer. The Bayesian approach is extended to two ordinal tests when verification bias is present, and the accuracy of the combined tests is based on the ROC area of the risk function. An example involving mammography with two readers with extreme verification bias illustrates the estimation of the combined test accuracy for ordinal tests. Diagnostics 2011-12-15 1 1 Article 10.3390/diagnostics1010053 53 76 2075-4418 2011-12-15 doi: 10.3390/diagnostics1010053 Lyle D. Broemeling http://www.mdpi.com/2075-4418/1/1/38 Objective: Intensive medical treatment of heart failure (HF) patients with diabetes may reduce the endothelial dysfunction and the accelerated atherosclerotic process seen in these patients. To study this, we investigated the endothelial function and the presence of atherosclerosis as measured by flow-mediated vasodilatation (FMD) and intima-media thickness (IMT) in intensively treated patients with coexisting HF and diabetes. Research Design and Method: FMD of the brachial artery and IMT of the common carotid arteries were determined in 26 patients with systolic HF and diabetes who were in intensive medical therapy, as well as in 19 healthy controls. The two groups were matched according to age and sex. In all subjects left ventricular ejection fraction was measured by two-dimensional echocardiography. Biochemical parameters including serum cholesterol, HDL and LDL, triglyceride, glucose, hemoglobin/hemoglobin-A1C (HbA1C), brain natriuretic peptide (BNP) and N-terminal pro-BNP were also assessed. Results: Mean FMD and IMT did not differ significantly between patients and controls. Left ventricular ejection fraction was lower in patients compared to controls (P < 0.001). The patients had a higher mean BNP, NT pro-BNP, triglyceride, HbA1C and glucose in comparison to controls. Cholesterol, HDL-cholesterol and LDL-cholesterol were lower in patients compared to controls. Conclusions: Intensively treated patients with coexisting systolic HF and diabetes seem to have normal endothelial function as measured by FMD and they have no sign of accelerated atherosclerosis as measured by IMT. This suggests a positive effect of medication on the cardiovascular alterations in this group of patients. Diagnostics 2011-12-08 1 1 Article 10.3390/diagnostics1010038 38 52 2075-4418 2011-12-08 doi: 10.3390/diagnostics1010038 Lisbeth Vestergaard Andersen Niels Wiinberg Christian Tuxen Andreas Kjær http://www.mdpi.com/2075-4418/1/1/36 Diagnostic methods in medicine are currently rapidly evolving and constantly improving. This is true for areas such as molecular diagnostics, biomarkers, as well as medical imaging. As one example, positron emission tomography (PET) has been called the fastest growing medical technology ever. Also, molecular diagnostics, at both the gene and protein levels, are developing rapidly due to advances in technology and, thereby, creating new possibilities. Early and valid diagnosis is crucial for proper treatment of patients. Moreover, advanced diagnostic methods are crucial for the upcoming era of tailored therapy. From an economic viewpoint, the cost of advanced treatments are increasingly indicating the need for better stratification and therapy monitoring of treatment, in order that these advanced treatments are limited to patients able to respond favorably. Collectively, the exciting area of medical diagnostics seems never to have been more important for patients and society. [...] Diagnostics 2011-11-23 1 1 Editorial 10.3390/diagnostics1010036 36 37 2075-4418 2011-11-23 doi: 10.3390/diagnostics1010036 Andreas Kjaer http://www.mdpi.com/2075-4418/1/1/1 Bayesian methods for medical test accuracy are presented, beginning with the basic measures for tests with binary scores: true positive fraction, false positive fraction, positive predictive values, and negative predictive value. The Bayesian approach is taken because of its efficient use of prior information, and the analysis is executed with a Bayesian software package WinBUGS®. The ROC (receiver operating characteristic) curve gives the intrinsic accuracy of medical tests that have ordinal or continuous scores, and the Bayesian approach is illustrated with many examples from cancer and other diseases. Medical tests include X-ray, mammography, ultrasound, computed tomography, magnetic resonance imaging, nuclear medicine and tests based on biomarkers, such as blood glucose values for diabetes. The presentation continues with more specialized methods suitable for measuring the accuracies of clinical studies that have verification bias, and medical tests without a gold standard. Lastly, the review is concluded with Bayesian methods for measuring the accuracy of the combination of two or more tests. Diagnostics 2011-05-05 1 1 Review 10.3390/diagnostics1010001 1 35 2075-4418 2011-05-05 doi: 10.3390/diagnostics1010001 Lyle D. Broemeling