Smartphone-based clinical diagnostics: towards democratization of evidence-based health care

Recent advancements in bioanalytical techniques have led to the development of novel and robust diagnostic approaches that hold promise for providing optimal patient treatment, guiding prevention programs and widening the scope of personalized medicine. However, these advanced diagnostic techniques are still complex, expensive and limited to centralized healthcare facilities or research laboratories. This significantly hinders the use of evidence-based diagnostics for resource-limited settings and the primary care, thus creating a gap between healthcare providers and patients, leaving these populations without access to precision and quality medicine. Smartphone-based imaging and sensing platforms are emerging as promising alternatives for bridging this gap and decentralizing diagnostic tests offering practical features such as portability, cost-effectiveness and connectivity. Moreover, towards simplifying and automating bioanalytical techniques, biosensors and lab-on-a-chip technologies have become essential to interface and integrate these assays, bringing together the high precision and sensitivity of diagnostic techniques with the connectivity and computational power of smartphones. Here, we provide an overview of the emerging field of clinical smartphone diagnostics and its contributing technologies, as well as their wide range of areas of application, which span from haematology to digital pathology and rapid infectious disease diagnostics.

Practical aspects of real-time pure shift HSQC experiments

Pure shift NMR spectroscopy has become an efficient tool for improving resolution in proton NMR spectra by removing the effect of homonuclear couplings. The introduction of real-time acquisition methods has allowed the main drawback of pure shift NMR, the long experiment times needed, to be circumvented. Real-time methods use periodic application of J-refocusing pulse sequence elements, acquiring a single free induction decay, in contrast to previous methods that construct a pure shift interferogram by concatenating excerpts from multiple free induction decays. In the important heteronuclear single-quantum correlation experiment, implementing real-time pure shift data acquisition typically leads to the simultaneous improvement of both resolution and sensitivity. The current limitations of and problems with real-time pure shift acquisition methods are discussed here in the context of heteronuclear single-quantum correlation experiments. We aim to provide a detailed account of the technical challenges, together with a practical guide to exploiting the full potential of such methods.

Suppression of 13C satellites in 1H DOSY spectra

Diffusion-ordered spectroscopy (DOSY) is a valuable tool for the analysis of intact mixtures, since it can separate the signals of components according to their apparent diffusion coefficients. However, DOSY experiments are acutely sensitive to spectral quality, and especially to signal overlap, which can lead to misleading apparent diffusion coefficients. Here, we introduce a new NMR experiment to reduce signal overlap in mixtures with a wide range of concentrations, by removing one-bond ¹³C satellites. In such high dynamic range mixtures, ¹³C isotopomer signals from major components can overlap with signals from minor components, causing problematic distortions in the diffusion domain of a DOSY spectrum. The new method, Oneshot-iDISPEL, is a combination of the Oneshot and DISPEL experiments, and its performance has been demonstrated on a Greek alcoholic beverage, ouzo, which contains small amounts of anise flavour components and sucrose. Ethanol is a major component, and the suppression of its ¹³C satellites reduces signal overlap with minor components, offering significant improvement in DOSY spectra.

Single center consecutive series cohort study of minimally invasive versus open resection for cancer in the esophagus or gastroesophageal junction

Minimally invasive esophagectomy (MIE) has been introduced at many centers worldwide as evidence is accumulating that it reduces the risk of postoperative morbidity and mortality and decreases the length of hospital stay compared to conventional open esophagectomy. The study is a single institution cohort study of 366 consecutive patients treated with curative intent for cancer in the esophagus or gastroesophageal junction, comparing MIE to open surgery. The outcomes studied were peroperative bleeding, operation time, lymph node yield, complications, length of stay and overall survival. The results showed that MIE was associated with reduced peroperative bleeding and operation time. The patients in the MIE group had a statistically significant reduced risk of postoperative complications, 60.2% compared to 78.8% in the open group. In the MIE group 28.4% of the patients had postoperative complications classified according to the Clavien-Dindo classification system as grade IIIb-V compared to 38.2% in the open group, P = 0.046. Median hospital stay was reduced with 10 days comparing MIE to open surgery, P < 0.001. Mean number of resected lymph nodes was 31 in the MIE group and 22 in the open group (P < 0.001), while the R0 resections were 91.5% versus 85% (P = 0.057). Overall long-term survival was higher in the MIE group, a difference that however did not reach statistical significance (adjusted hazard ratio for three-year survival 0.76, 95% CI 0.54-1.08). In conclusion, MIE at a high volume center with a devoted specialist team reduces the risk of peroperative bleeding, operation time, and severe postoperative complications compared to open surgery for esophageal or junctional cancer. The number of resected lymph nodes was increased and the R0 resections were similar between the groups indicating a good oncological quality of the surgery.

Semi-real-time acquisition for fast pure shift NMR at maximum resolution

Homonuclear decoupling can give impressive improvements in spectral resolution when overlapping multiplet structures limit the interpretability of NMR spectra. General homodecoupling methods ("pure shift NMR") typically use either interferogram-style acquisition, which is slow but gives optimum resolution, or real-time acquisition, which is fast but gives broader lines. Here we describe an alternative data acquisition strategy that allows rapid acquisition without resolution loss, illustrating the method with band-selective homodecoupling experiments and demonstrating its advantages over competing methods.

PSYCHE Pure Shift NMR Spectroscopy

Broadband homodecoupling techniques in NMR, also known as "pure shift" methods, aim to enhance spectral resolution by suppressing the effects of homonuclear coupling interactions to turn multiplet signals into singlets. Such techniques typically work by selecting a subset of "active" nuclear spins to observe, and selectively inverting the remaining, "passive", spins to reverse the effects of coupling. Pure Shift Yielded by Chirp Excitation (PSYCHE) is one such method; it is relatively recent, but has already been successfully implemented in a range of different NMR experiments. Paradoxically, PSYCHE is one of the trickiest of pure shift NMR techniques to understand but one of the easiest to use. Here we offer some insights into theoretical and practical aspects of the method, and into the effects and importance of the experimental parameters. Some recent improvements that enhance the spectral purity of PSYCHE spectra will be presented, and some experimental frameworks, including examples in 1D and 2D NMR spectroscopy, for the implementation of PSYCHE will be introduced.

Purinergic modulation of glutamate transmission: An expanding role in stress-linked neuropathology

Chronic stress has been extensively linked to disturbances in glutamatergic signalling. Emerging from this field of research is a considerable number of studies identifying the ability of purines at the pre-, post-, and peri-synaptic levels to tune glutamatergic neurotransmission. While the evidence describing purinergic control of glutamate has continued to grow, there has been relatively little attention given to how chronic stress modulates purinergic functions. The available research on this topic has demonstrated that chronic stress can not only disturb purinergic receptors involved in the regulation of glutamate neurotransmission, but also perturb glial-dependent purinergic signalling. This review will provide a detailed examining of the complex literature relating to glutamatergic-purinergic interactions with a focus on both neuronal and glial contributions. Once these detailed interactions have been described and contextualised, we will integrate recent findings from the field of stress research.

The GNAT: A new tool for processing NMR data

The GNAT (General NMR Analysis Toolbox) is a free and open-source software package for processing, visualising, and analysing NMR data. It supersedes the popular DOSY Toolbox, which has a narrower focus on diffusion NMR. Data import of most common formats from the major NMR platforms is supported, as well as a GNAT generic format. Key basic processing of NMR data (e.g., Fourier transformation, baseline correction, and phasing) is catered for within the program, as well as more advanced techniques (e.g., reference deconvolution and pure shift FID reconstruction). Analysis tools include DOSY and SCORE for diffusion data, ROSY T₁ /T₂ estimation for relaxation data, and PARAFAC for multilinear analysis. The GNAT is written for the MATLAB® language and comes with a user-friendly graphical user interface. The standard version is intended to run with a MATLAB installation, but completely free-standing compiled versions for Windows, Mac, and Linux are also freely available.

Improving the Interpretation of Small Molecule Diffusion Coefficients

Diffusion-ordered NMR spectroscopy (DOSY) is increasingly widely used for the analysis of mixtures by NMR spectroscopy, dispersing the signals of different species according to their diffusion coefficients. DOSY is used primarily to distinguish between the signals of different species, with the interpretation of the diffusion coefficients observed usually being purely qualitative, for example to deduce whether one species is bigger or smaller than another. In principle, the actual values of diffusion coefficient obtained carry important information about the sizes of different species and on interactions between species, but the relationship between diffusion coefficient and molecular mass is in general a very complex one. Here a recently proposed analytical relationship between diffusion coefficient and molecular mass for the restricted case of small organic molecules is tested against a wide range of data from the scientific literature and generalized to cover a range of solvents and temperatures.

Surgical management of esophageal sarcoma: a multicenter European experience

Esophageal sarcomas are rare and evidence in literature is scarce making their management difficult. The objective is to report surgical and oncological outcomes of esophageal sarcoma in a large multicenter European cohort. This is a retrospective multicenter study including all patients who underwent en-bloc esophagectomy for esophageal sarcoma in seven European tertiary referral centers between 1987 and 2016. The main outcomes and measures are pathological results, early and long-term outcomes. Among 10,936 esophageal resections for cancer, 21 (0.2%) patients with esophageal sarcoma were identified. The majority of tumors was located in the middle (n = 7) and distal (n = 9) third of the esophagus. Neoadjuvant chemoradiotherapy was performed in five patients. All the patients underwent en-bloc transthoracic esophagectomy (19 open, 2 minimally invasive). Postoperative mortality occurred in 1 patient (5%). One patient received adjuvant chemotherapy. Definitive pathological results were carcinosarcoma (n = 7), leiomyosarcoma (n = 5), and other types of sarcoma (n = 9). Microscopic R1 resection was present in one patient (5%) and seven patients (33%) had positive lymph nodes. Median follow-up was 16 (3-79) months in 20 of 21 patients (95%). One-, 3-, and 5-year overall survival rates were 74%, 43%, and 35%, respectively. One-, 3- and 5-years disease-free survival rates were 58%, 40%, and 33%, respectively. Median overall survival was 6 months in N+ patients vs. 37 months for N0 patients (p = 0.06). At the end of the follow-up period, nine patients had died from cancer recurrences (43%), three patients died from other reasons (14%), one patient was still alive with recurrence (5%) and the seven remaining patients were free of disease (33%). Recurrence was local (n = 3), metastatic (n = 3), or both (n = 4). In conclusion, carcinosarcoma and leiomyosarcoma were the most common esophageal sarcoma histological subtypes. Lymph node involvement was seen in one third of cases. A transthoracic en-bloc esophagectomy with radical lymphadenectomy should be the best surgical option to achieve complete resection. Long-term survival remained poor with a high local and distant recurrence rate.

A structured training program for minimally invasive esophagectomy for esophageal cancer- a Delphi consensus study in Europe

Evidence suggests that structured training programs for laparoscopic procedures can ensure a safe standard of skill acquisition prior to independent practice. Although minimally invasive esophagectomy (MIO) is technically demanding, no consensus on requirements for training for the MIO procedure exists. The aim of this study is to determine essential steps required for a structured training program in MIO using the Delphi consensus methodology. Eighteen MIO experts from 13 European hospitals were asked to participate in this study. The consensus process consisted of two structured meetings with the expert panel, and two Delphi questionnaire rounds. A list of items required for training MIO were constructed for three key domains of MIO, including (1) requisite criteria for units wishing to be trained and (2) to proctor MIO, and (3) a framework of a MIO training program. Items were rated by the experts on a scale 1-5, where 1 signified 'not important' and 5 represented 'very important.' Consensus for each domain was defined as achieving Cronbach alpha ≥0.70. Items were considered as fundamental when ≥75% of experts rated it important (4) or very important (5). Both Delphi rounds were completed by 16 (89%) of the 18 invited experts, with a median experience of 18 years with minimally invasive surgery. Consensus was achieved for all three key domains. Following two rounds of a 107-item questionnaire, 50 items were rated as essential for training MIO. A consensus among European MIO experts on essential items required for training MIO is presented. The identified items can serve as directive principles and core standards for creating a comprehensive training program for MIO.

Identical genotypes of community-associated MRSA (ST59) and livestock-associated MRSA (ST9) in humans and pigs in rural China

This study investigated the prevalence of MRSA in samples taken in households, with and without backyard pigs in villages in a rural area of Shandong Province, China. Community-associated MRSA and livestock-associated MRSA, belonging to ST59 and ST9, respectively, were identified in both humans and pigs. The genotypic and phenotypic comparison of isolates indicates that bidirectional transmission of MRSA has occurred between humans and pigs in the villages.