The Potential Role of Salivary NT-proBNP in Heart Failure

BACKGROUND

Serum natriuretic peptides (NPs) have an established role in heart failure (HF) diagnosis. Saliva NT-proBNP that may be easily acquired has been studied little.

METHODS

Ninety-nine subjects were enrolled; thirty-six obese or hypertensive with dyspnoea but no echocardiographic HF findings or raised NPs served as controls, thirteen chronic HF (CHF) patients and fifty patients with acute decompensated HF (ADHF) requiring hospital admission. Electrocardiogram, echocardiogram, 6 min walking distance (6MWD), blood and saliva samples, were acquired in all participants.

RESULTS

Serum NT-proBNP ranged from 60-9000 pg/mL and saliva NT-proBNP from 0.64-93.32 pg/mL. Serum NT-proBNP was significantly higher in ADHF compared to CHF (p = 0.007) and in CHF compared to controls (p < 0.05). There was no significant difference in saliva values between ADHF and CHF, or between CHF and controls. Saliva and serum levels were positively associated only in ADHF patients (R = 0.352, p = 0.012). Serum NT-proBNP was positively associated with NYHA class (R = 0.506, p < 0.001) and inversely with 6MWD (R = -0.401, p = 0.004) in ADHF. Saliva NT-proBNP only correlated with age in ADHF patients.

CONCLUSIONS

In the current study, saliva NT-proBNP correlated with serum values in ADHF patients, but could not discriminate between HF and other causes of dyspnoea. Further research is needed to explore the value of saliva NT-proBNP.

HiSorb sorptive extraction for determining salivary short chain fatty acids and hydroxy acids in heart failure patients

Variations in salivary short-chain fatty acids and hydroxy acids (e.g., lactic acid, and 3-hydroxybutyric acid) levels have been suggested to reflect the dysbiosis of human gut microbiota, which represents an additional factor involved in the onset of heart failure (HF) disease. The physical-chemical properties of these metabolites combined with the complex composition of biological matrices mean that sample pre-treatment procedures are almost unavoidable. This work describes a reliable, simple, and organic solvent free protocol for determining short-chain fatty acids and hydroxy acids in stimulated saliva samples collected from heart failure, obese, and hypertensive patients. The procedure is based on in-situ pentafluorobenzyl bromide (PFB-Br) derivatization and HiSorb sorptive extraction coupled to thermal desorption and gas chromatography-tandem mass spectrometry. The HiSorb extraction device is completely compatible with aqueous matrices, thus saving on time and materials associated with organic solvent-extraction methods. A Central Composite Face-Centred experimental design was used for the optimization of the molar ratio between PFB-Br and target analytes, the derivatization temperature, and the reaction time which were 100, 60 °C, and 180 min, respectively. Detection limits in the range 0.1-100 µM were reached using a small amount of saliva (20 µL). The use of sodium acetate-1-13C as an internal standard improved the intra- and inter-day precision of the method which ranged from 10 to 23%. The optimized protocol was successfully applied for what we believe is the first time to evaluate the salivary levels of short chain fatty acids and hydroxy acids in saliva samples of four groups of patients: i) patients admitted to hospital with acute HF symptoms, ii) patients with chronic HF symptoms, iii) patients without HF symptoms but with obesity, and iv) patients without HF symptoms but with hypertension. The first group of patients showed significantly higher levels of salivary acetic acid and lactic acid at hospital admission as well as the lowest values of hexanoic acid and heptanoic acid. Moreover, the significant high levels of acetic acid, propionic acid, and butyric acid observed in HF respect to the other patients suggest the potential link between oral bacteria and gut dysbiosis.

Salivary lipid mediators: Key indexes of inflammation regulation in heart failure disease

Cardiovascular diseases (CVDs) are the leading cause of premature death and disability in humans and their incidence continues to increase. Oxidative stress and inflammation have been recognized as key pathophysiological factors in cardiovascular events. The targeted modulation of the endogenous mechanisms of inflammation, rather than its simple suppression, will become key in treating chronic inflammatory diseases. A comprehensive characterization of the signalling molecules involved in inflammation, such as endogenous lipid mediators, is thus needed. Here, we propose a powerful MS-based platform for the simultaneous quantitation of sixty salivary lipid mediators in CVD samples. Saliva, which represents a non-invasive and painless alternative to blood, was collected from patients suffering from acute and chronic heart failure (AHF and CHF, respectively), obesity and hypertension. Of all the patients, those with AHF and hypertension showed higher levels of isoprostanoids, which are key indexes of oxidant insult. Compared to the obese population, AHF patients showed lower levels (p < 0.02) of antioxidant omega-3 fatty acids, in line with the "malnutrition-inflammation complex syndrome" typical of HF patients. At hospital admission, AHF patients showed significantly higher levels (p < 0.001) of omega-3 DPA and lower levels (p < 0.04) of lipoxin B₄ than CHF patients, suggesting a lipid rearrangement typical of the failing heart during acute decompensation. If confirmed, our results highlight the potential use of lipid mediators as predictive markers of re-acutisation episodes, thus providing opportunities for preventive intervention and a reduction in hospitalizations.

Sweat analysis with a wearable sensing platform based on laser-induced graphene

The scientific community has shown increasing interest in laser scribing for the direct fabrication of conductive graphene-based tracks on different substrates. This can enable novel routes for the noninvasive analysis of biofluids (such as sweat or other noninvasive matrices), whose results can provide the rapid evaluation of a person's health status. Here, we present a wearable sensing platform based on laser induced graphene (LIG) porous electrodes scribed on a flexible polyimide sheet, which samples sweat through a paper sampler. The device is fully laser manufactured and features a two layer design with LIG-based vertical interconnect accesses. A detailed characterization of the LIG electrodes including pore size, surface groups, surface area in comparison to electroactive surface area, and the reduction behavior of different LIG types was performed. The bare LIG electrodes can detect the electrochemical oxidation of both uric acid and tyrosine. Further modification of the surface of the LIG working electrode with an indoaniline derivative [4-((4-aminophenyl)imino)-2,6-dimethoxycyclohexa-2,5-dien-1-one] enables the voltammetric measurement of pH with an almost ideal sensitivity and without interference from other analytes. Finally, electrochemical impedance spectroscopy was used to measure the concentrations of ions through the analysis of the sweat impedance. The device was successfully tested in a real case scenario, worn on the skin during a sports session. In vitro tests proved the non-cytotoxic effect of the device on the A549 cell line.

Effects of long-term vegan diet on breath composition

The composition of exhaled breath derives from an intricate combination of normal and abnormal physiological processes that are modified by the consumption of food and beverages, circadian rhythms, bacterial infections, and genetics as well as exposure to xenobiotics. This complexity, which results wide intra- and inter-individual variability and is further influenced by sampling conditions, hinders the identification of specific biomarkers and makes it difficult to differentiate between pathological and nominally healthy subjects. The identification of a "normal" breath composition and the relative influence of the aforementioned parameters would make breath analyses much faster for diagnostic applications. We thus compared, for the first time, the breath composition of age-matched volunteers following a vegan and a Mediterranean omnivorous diet in order to evaluate the impact of diet on breath composition. Mixed breath was collected from 38 nominally healthy volunteers who were asked to breathe into a two-liter handmade Nalophan bag. Exhalation flow rate and carbon dioxide values were monitored during breath sampling. An aliquot (100 mL) of breath was loaded into a sorbent tube (250 mg of Tenax GR, 60/80 mesh) before being analyzed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Breath profiling using TD-GC-MS analysis identified five compounds (methanol, 1-propanol, pentane, hexane, and hexanal), thus enabling differentiation between samples collected from the different group members . Principal component analysis showed a clear separation between groups, suggesting that breath analysis could be used to study the influence of dietary habits in the fields of nutrition and metabolism. Surprisingly, one Italian woman and her brother showed extremely low breath isoprene levels (about 5 ppbv), despite their normal lipidic profile and respiratory data, such as flow rate and pCO2. Further investigations to reveal the reasons behind low isoprene levels in breath would help reveal the origin of isoprene in breath.

Effectiveness of Blue light photobiomodulation therapy in the treatment of chronic wounds. Results of the Blue Light for Ulcer Reduction (B.L.U.R.) Study

BACKGROUND

Lower limb ulcers not responding to standard treatments after 8 weeks are defined as chronic wounds, and they are a significant medical problem. Blue light (410-430 nm) proved to be effective in treating wounds, but there is a lack of data on chronic wounds in clinical practice. The study's purpose was to determine if Blue Light photobiomodulation with EmoLED medical device in addition to Standard of Care is more effective compared to Standard of care alone in promoting re-epithelialization of chronicwounds of lower limbs in 10 weeks.

METHODS

90 patients affected by multiple or large area ulcers were enrolled. To minimize all variabilities, each patient has been used as control of himself. Primary endpoint was the comparison of the re-epithelialization rate expressed as a percentage of the difference between the initial and final area. Secondary endpoints were: treatment safety, pain reduction, wound area reduction trend over time, healing rate.

RESULTS

At week 10, the wounds treated with EmoLED in addition to Standard Care showed a smaller residual wound area compared to the wounds treated with Standard of Care alone: 42.1% vs 63.4% (p=0.029). The difference is particularly evident in venous leg ulcers, 33.3% vs 60.1% (p=0.007). 17 treated wounds and 12 controls showed complete healing at week 10. Patients showed a significant reduction in pain (p = 2*10-7).

CONCLUSIONS

Blue Light treatment in addition to Standard of Care accelerates consistently the re-epithelialization rate of chronic wounds, especially venous leg ulcers and increases the chances of total wound healing in 10 weeks.

Three-Dimensional (3D) Laser-Induced Graphene: Structure, Properties, and Application to Chemical Sensing

Notwithstanding its relatively recent discovery, graphene has gone through many evolution steps and inspired a multitude of applications in many fields, from electronics to life science. The recent advancements in graphene production and patterning, and the inclusion of two-dimensional (2D) graphenic materials in three-dimensional (3D) superstructures, further extended the number of potential applications. In this Review, we focus on laser-induced graphene (LIG), an intriguing 3D porous graphenic material produced by direct laser scribing of carbonaceous precursors, and on its applications in chemical sensors and biosensors. LIG can be shaped in different 3D forms with a high surface-to-volume ratio, which is a valuable characteristic for sensors that typically rely on phenomena occurring at surfaces and interfaces. Herein, an overview of LIG, including synthesis from various precursors, structure, and characteristic properties, is first provided. The discussion focuses especially on transport and surface properties, and on how these can be controlled by tuning the laser processing. Progresses and trends in LIG-based chemical sensors are then reviewed, discussing the various transduction mechanisms and different LIG functionalization procedures for chemical sensing. A comparative evaluation of sensors performance is then provided. Finally, sensors for glucose detection are reviewed in more detail, since they represent the vast majority of LIG-based chemical sensors.

Determination and stability of N-terminal pro-brain natriuretic peptide in saliva samples for monitoring heart failure

Heart failure (HF) is the main cause of mortality worldwide, particularly in the elderly. N-terminal pro-brain natriuretic peptide (NT-proBNP) is the gold standard biomarker for HF diagnosis and therapy monitoring. It is determined in blood samples by the immunochemical methods generally adopted by most laboratories. Saliva analysis is a powerful tool for clinical applications, mainly due to its non-invasive and less risky sampling. This study describes a validated analytical procedure for NT-proBNP determination in saliva samples using a commercial Enzyme-Linked Immuno-Sorbent Assay. Linearity, matrix effect, sensitivity, recovery and assay-precision were evaluated. The analytical approach showed a linear behaviour of the signal throughout the concentrations tested, with a minimum detectable dose of 1 pg/mL, a satisfactory NT-proBNP recovery (95-110%), and acceptable precision (coefficient of variation ≤ 10%). Short-term (3 weeks) and long-term (5 months) stability of NT-proBNP in saliva samples under the storage conditions most frequently used in clinical laboratories (4, - 20, and - 80 °C) was also investigated and showed that the optimal storage conditions were at - 20 °C for up to 2.5 months. Finally, the method was tested for the determination of NT-proBNP in saliva samples collected from ten hospitalized acute HF patients. Preliminary results indicate a decrease in NT-proBNP in saliva from admission to discharge, thus suggesting that this procedure is an effective saliva-based point-of-care device for HF monitoring.

Salivary Biomarkers for Diagnosis and Therapy Monitoring in Patients with Heart Failure. A Systematic Review

The aim of this study was to perform a systematic review on the potential value of saliva biomarkers in the diagnosis, management and prognosis of heart failure (HF). The correlation between saliva and plasma values of these biomarkers was also studied. PubMed was searched to collect relevant literature, i.e., case-control, cross-sectional studies that either compared the values of salivary biomarkers among healthy subjects and HF patients, or investigated their role in risk stratification and prognosis in HF patients. No randomized control trials were included. The search ended on 31st of December 2020. A total of 15 studies met the inclusion criteria. 18 salivary biomarkers were analyzed and the levels of all biomarkers studied were found to be higher in HF patients compared to controls, except for amylase, sodium, and chloride that had smaller saliva concentrations in HF patients. Natriuretic peptides are the most commonly used plasma biomarkers in the management of HF. Their saliva levels show promising results, although the correlation of saliva to plasma values is weakened in higher plasma values. In most of the publications, differences in biomarker levels between HF patients and controls were found to be statistically significant. Due to the small number of patients included, larger studies need to be conducted in order to facilitate the use of saliva biomarkers in clinical practice.

Stability of volatile organic compounds in sorbent tubes following SARS-CoV-2 inactivation procedures

COVID-19 is a highly transmissible respiratory illness that has rapidly spread all over the world causing more than 115 million cases and 2.5 million deaths. Most epidemiological projections estimate that the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus causing the infection will circulate in the next few years and raise enormous economic and social issues. COVID-19 has a dramatic impact on health care systems and patient management, and is delaying or stopping breath research activities due to the risk of infection to the operators following contact with patients, potentially infected samples or contaminated equipment. In this scenario, we investigated whether virus inactivation procedures, based on a thermal treatment (60 °C for 1 h) or storage of tubes at room temperature for 72 h, could be used to allow the routine breath analysis workflow to carry on with an optimal level of safety during the pandemic. Tests were carried out using dry and humid gaseous samples containing about 100 representative chemicals found in exhaled breath and ambient air. Samples were collected in commercially available sorbent tubes, i.e. Tenax GR and a combination of Tenax TA, Carbograph 1TD and Carboxen 1003. Our results showed that all compounds were stable at room temperature up to 72 h and that sample humidity was the key factor affecting the stability of the compounds upon thermal treatment. Tenax GR-based sorbent tubes were less impacted by the thermal treatment, showing variations in the range 20%-30% for most target analytes. A significant loss of aldehydes and sulphur compounds was observed using carbon molecular sieve-based tubes. In this case, a dry purge step before inactivation at 60 °C significantly reduced the loss of the target analytes, whose variations were comparable to the method variability. Finally, a breath analysis workflow including a SARS-CoV-2 inactivation treatment is proposed.

COVID-19 pandemic and eating disorders: What impact on specific and general psychopathology?

Introduction

The coronavirus disease 2019 (COVID-19) pandemic and the resulting containment measures, such as “lockdown” and “social distancing”, have had important consequences on people’s mental and physical health.

Objectives

We aimed to study the effect of social isolation and subsequent re- exposure and eventual changes in general and ED-specific psychopathology in people with Eating Disorders (EDs).

Methods

Three-hundred twelve Italian people with EDs (179 Anorexia Nervosa, 83 Bulimia Nervosa, 48 Binge Eating Disorder and 22 Other Specific Feeding Eating Disorder) were asked to fill-in an online survey to explore several dimensions such as: anxiety, depression, panic, insomnia, suicide ideation, stress, post-traumatic stress and obsessive-compulsive symptoms. Differences in ED specific and general symptoms among the 3 investigated time periods (before, during and after the end of lockdown) were assessed with a one-way ANOVA with repeated measures. Subsequently, ED diagnosis was introduced as covariate in the analysis in order to investigate the possible contribution on psychopathological changes.

Results

ED core symptoms increased during the lockdown but most of them returned to pre-COVID19 levels at re-opening. The severity of general psychopathology also increased during the lockdown and persisted high in the following phase, except for depression and suicide ideation. None of this symptoms was affected by ED diagnosis, participants’age and illness duration.

Conclusions

People with EDs showed worsening of both general and specific psychopathology; moreover, changes in general psychopathology persisted in the re-opening period suggesting a higher stress vulnerability in this kind of patients.

Disclosure

No significant relationships.

Keyword

COVID19 and Eating Disorders

The novel Mechanical Ventilator Milano for the COVID-19 pandemic

This paper presents the Mechanical Ventilator Milano (MVM), a novel intensive therapy mechanical ventilator designed for rapid, large-scale, low-cost production for the COVID-19 pandemic. Free of moving mechanical parts and requiring only a source of compressed oxygen and medical air to operate, the MVM is designed to support the long-term invasive ventilation often required for COVID-19 patients and operates in pressure-regulated ventilation modes, which minimize the risk of furthering lung trauma. The MVM was extensively tested against ISO standards in the laboratory using a breathing simulator, with good agreement between input and measured breathing parameters and performing correctly in response to fault conditions and stability tests. The MVM has obtained Emergency Use Authorization by U.S. Food and Drug Administration (FDA) for use in healthcare settings during the COVID-19 pandemic and Health Canada Medical Device Authorization for Importation or Sale, under Interim Order for Use in Relation to COVID-19. Following these certifications, mass production is ongoing and distribution is under way in several countries. The MVM was designed, tested, prepared for certification, and mass produced in the space of a few months by a unique collaboration of respiratory healthcare professionals and experimental physicists, working with industrial partners, and is an excellent ventilator candidate for this pandemic anywhere in the world.

Advances in biosensing: The CRISPR/Cas system as a new powerful tool for the detection of nucleic acids

A main challenge in the development of biosensing devices for the identification and quantification of nucleic acids is to avoid the amplification of the genetic material from the sample by polymerase chain reaction (PCR), which is at present necessary to enhance sensitivity and selectivity of assays. PCR has undoubtedly revolutionized genetic analyses, but it requires careful purification procedures that are not easily implemented in point of care (POC) devices. In recent years, a new strategy for nucleic acid detection based on clustered regularly interspaced short palindromic repeats (CRISPR) and associated protein systems (Cas) seems to offer unprecedented possibilities. The coupling of the CRISPR/Cas system with recent isothermal amplification methods is fostering the development of innovative optical and electrochemical POC devices. In this review, the mechanisms of action of several new CRISRP/Cas systems are reported together with their use in biosensing of nucleic acids.

Biosensors for Detecting Lymphocytes and Immunoglobulins

Lymphocytes (B, T and natural killer cells) and immunoglobulins are essential for the adaptive immune response against external pathogens. Flow cytometry and enzyme-linked immunosorbent (ELISA) kits are the gold standards to detect immunoglobulins, B cells and T cells, whereas the impedance measurement is the most used technique for natural killer cells. For point-of-care, fast and low-cost devices, biosensors could be suitable for the reliable, stable and reproducible detection of immunoglobulins and lymphocytes. In the literature, such biosensors are commonly fabricated using antibodies, aptamers, proteins and nanomaterials, whereas electrochemical, optical and piezoelectric techniques are used for detection. This review describes how these measurement techniques and transducers can be used to fabricate biosensors for detecting lymphocytes and the total content of immunoglobulins. The various methods and configurations are reported, along with the advantages and current limitations.

Salivary lactate and 8-isoprostaglandin F2α as potential non-invasive biomarkers for monitoring heart failure: a pilot study

Heart failure (HF) is a cardiovascular disease affecting about 26 million people worldwide costing about $100 billons per year. HF activates several compensatory mechanisms and neurohormonal systems, so we hypothesized that the concomitant monitoring of a panel of potential biomarkers related to such conditions might help predicting HF evolution. Saliva analysis by point-of-care devices is expected to become an innovative and powerful monitoring approach since the chemical composition of saliva mirrors that of blood. The aims of this study were (i) to develop an innovative procedure combining MEPS with UHPLC-MS/MS for the simultaneous determination of 8-isoprostaglandin F_2α and cortisol in saliva and (ii) to monitor lactate, uric acid, TNF-α, cortisol, α-amylase and 8-isoprostaglandin F_2α concentrations in stimulated saliva samples collected from 44 HF patients during their hospitalisation due to acute HF. Limit of detection of 10 pg/mL, satisfactory recovery (95–110%), and good intra- and inter-day precisions (RSD ≤ 10%) were obtained for 8-isoprostaglandin F_2α and cortisol. Salivary lactate and 8-isoprostaglandin F_2α were strongly correlated with NT-proBNP. Most patients (about 70%) showed a significant decrease (a factor of 3 at least) of both lactate and 8-isoprostaglandin F_2α levels at discharge, suggesting a relationship between salivary levels and improved clinical conditions during hospitalization.

A graphene-based pH sensor on paper for human plasma and seawater

The relevance of pH assessment in clinical analysis, environmental and industrial control, has raised the demand for the development of portable, low cost and easy-to-use monitoring systems. This paper proposes a pH sensor printed on a paper support passivated with a solid-ink coating. The sensor exploits the pH sensitivity of a reduced graphene oxide functionalized with 3-(4-aminophenil)propionic acid. The sensor responded in the pH range [4], [10] and had a sensitivity of 46 mV/pH. Tests on human plasma and seawater proved this pH sensor to have similar performances than those of a commercial pH-meter with an uncertainty of 0.1 and 0.2 pH unit in plasma and seawater, respectively.

KardiaSoft Architecture - A Software Supporting Diagnosis and Therapy Monitoring of Heart Failure Patients Exploiting Saliva Biomarkers

The aim of this work is to present the architecture of the KardiaSoft software, a clinical decision support tool allowing the healthcare professionals to monitor patients with heart failure by providing useful information and suggestions in terms of the estimation of the presence of heart failure (heart failure diagnosis), stratification-patient profiling, long term patient condition evaluation and therapy response monitoring. KardiaSoft is based on predictive modeling techniques that analyze data that correspond to four saliva biomarkers, measured by a point-of-care device, along with other patient's data. The KardiaSoft is designed based on the results of a user requirements elicitation process. A small clinical scale study with 135 subjects and an early clinical study with 90 subjects will take place in order to build and validate the predictive models, respectively.

A Biosensor for the Detection of Acetylcholine and Diazinon

Acetylcholine is a neurotransmitter and a neuromodulator found in the autonomic, peripheral and central nervous systems. Diazinon is a pesticide with toxic effects on humans, such as the inhibition of acetylcholine. In this paper, a biosensor is proposed for the detection of acetylcholine (range 70 - 1000 μM) and diazinon (range 0.3 - 20000 ppb). This biosensor combines a pH-sensitive layer of reduced graphene oxide functionalized with 4-aminobenzoic acid and acetylcholinesterase. This enzyme was immobilized on reduced graphene oxide and it catalyzed the conversion of acetylcholine into choline and acetic acid, locally decreasing the pH value and triggering the sensor response. The limit of detection for the acetylcholine and diazinon were 70 μM and 0.3 ppb, respectively.

A sampler prototype for the simultaneous collection of exhaled air and breath condensate

Exhaled air and breath condensate contain a large number of health biomarkers, such as volatile and semi-volatile organic compounds, proteins and lipids. Nowadays, the collection of breath samples is carried out by commercial or lab-made sampling systems that collect only one type of sample (e.g. gaseous or condensate phase), thus limiting the diagnostic capability of breath tests. This work presents a portable prototype optimized for the simultaneous collection of gaseous exhaled breath and exhaled breath condensate within five minutes. The system is fully portable and has a total weight of about 1 Kg. An illustrative determination of ethanol, isoprene, acetone, isopropyl alcohol, 1-propanol, 2-butanone, 2-pentanone, toluene and xylenes in breath, and cortisol and 8-iso-prostaglandin F_2α in breath condensate is discussed.

KardiaTool: An Integrated POC Solution for Non-invasive Diagnosis and Therapy Monitoring of Heart Failure Patients

The aim of this work is to present KardiaTool platform, an integrated Point of Care (POC) solution for noninvasive diagnosis and therapy monitoring of Heart Failure (HF) patients. The KardiaTool platform consists of two components, KardiaPOC and KardiaSoft. KardiaPOC is an easy to use portable device with a disposable Lab-on-Chip (LOC) for the rapid, accurate, non-invasive and simultaneous quantitative assessment of four HF related biomarkers, from saliva samples. KardiaSoft is a decision support software based on predictive modeling techniques that analyzes the POC data and other patient's data, and delivers information related to HF diagnosis and therapy monitoring. It is expected that identifying a source comparable to blood, for biomarker information extraction, such as saliva, that is cost-effective, less invasive, more convenient and acceptable for both patients and healthcare professionals would be beneficial for the healthcare community. In this work the architecture and the functionalities of the KardiaTool platform are presented.

Room temperature amine sensors enabled by sidewall functionalization of single-walled carbon nanotubes

A new series of sidewall modified single-walled carbon nanotubes (SWCNTs) with perfluorophenyl molecules bearing carboxylic acid or methyl ester moieties are herein reported. Pristine and functionalized SWCNTs (p-SWCNTs and f-SWCNTs, respectively) were characterized by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning electron microscopy (SEM). The nitrene-based functionalization provided intact SWCNTs with methyl 4-azido-2,3,5,6-tetrafluorobenzoate (SWCNT-N-C6F4CO2CH3) and 4-azido-2,3,5,6-tetrafluorobenzoic acid (SWCNT-N-C6F4CO2H) attached every 213 and 109 carbon atoms, respectively. Notably, SWCNT-N-C6F4CO2H was sensitive in terms of the percentage of conductance variation from 5 to 40 ppm of ammonia (NH3) and trimethylamine (TMA) with a two-fold higher variation of conductance compared to p-SWCNTs at 40 ppm. The sensors are highly sensitive to NH3 and TMA as they showed very low responses (0.1%) toward 200 ppm of volatile organic compounds (VOCs) containing various functional groups representative of different classes of analytes such as benzene, tetrahydrofurane (THF), hexane, ethyl acetate (AcOEt), ethanol, acetonitrile (CH3CN), acetone and chloroform (CHCl3). Our system is a promising candidate for the realization of single-use chemiresistive sensors for the detection of threshold crossing by low concentrations of gaseous NH3 and TMA at room temperature.

Determination of volatile organic compounds in exhaled breath of heart failure patients by needle trap micro-extraction coupled with gas chromatography-tandem mass spectrometry

The analytical performances of needle trap micro-extraction (NTME) coupled with gas chromatography-tandem mass spectrometry were evaluated by analyzing a mixture of twenty-two representative breath volatile organic compounds (VOCs) belonging to different chemical classes (i.e. hydrocarbons, ketones, aldehydes, aromatics and sulfurs). NTME is an emerging technique that guarantees detection limits in the pptv range by pre-concentrating low volumes of sample, and it is particularly suitable for breath analysis. For most VOCs, detection limits between 20 and 500 pptv were obtained by pre-concentrating 25 ml of a humidified standard gas mixture at a flow rate of 15 ml min^-1. For all compounds, inter- and intra-day precisions were always below 15%, confirming the reliability of the method. The procedure was successfully applied to the analysis of exhaled breath samples collected from forty heart failure (HF) patients during their stay in the University Hospital of Pisa. The majority of patients (about 80%) showed a significant decrease of breath acetone levels (a factor of 3 or higher) at discharge compared to admission (acute phase) in correspondence to the improved clinical conditions during hospitalization, thus making this compound eligible as a biomarker of HF exacerbation.

A graphene oxide pH sensor for wound monitoring

This article describes the fabrication and characterization of a pH sensor for monitoring the wound status. The pH sensitive layer consists of a graphene oxide (GO) layer obtained by drop-casting 5 μΐ of GO dispersion onto the working electrode of a screen-printed substrate. Sensitivity was 31.8 mV/pH with an accuracy of 0.3 unit of pH. Open-circuit potentiometry was carried out to measure pH in an exudate sample. The GO pH sensor proved to be reliable as the comparison with results obtained from a standard glass electrode pH-meter showed negligible differences (<; 0.09 pH units in the worst case) for measurements performed over a period of 4 days.

Potentiometric sensor for non invasive lactate determination in human sweat

The present work describes a non invasive lactate sensing in sweat during workout. The sensing system is based on a non-equilibrium potentiometric measure performed using disposable, chemically modified, screen printed carbon electrodes (SPCEs) that can be wetted with sweat during the exercise. The potentiometric signal, which is proportional to lactate concentration in sweat, is produced by a redox reaction activated by UV radiation, as opposed to the enzymatic reaction employed in traditional, blood-based measuring devices. The sensing system exhibits chemical selectivity toward lactate with linearity from 1 mM up to 180 mM. The dynamic linear range is suitable for measurement of lactate in sweat, which is more than 10 times concentrated than hematic lactate and reaches more than 100 mM in sweat during workout. The noninvasive measure can be repeated many times during exercise and during the recovery time in order to get personal information on the physiological and training status as well as on the physical performance. The device was successfully applied to several human subjects for the measurement of sweat lactate during prolonged cycling exercise. During the exercise sweat was simultaneously sampled on filter paper and extracted in water, and the lactate was determined by HPLC for method validation. The lactate concentration changes during the exercise reflected the intensity of physical effort. This method has perspectives in many sport disciplines as well as in health care and biomedical area.

Effects of genotype, wilting, and additives on the nutritive value and fermentation of bermudagrass silage

Bermudagrass is the main warm-season grass species used for livestock production in the southeastern United States; however, when it is ensiled, the silage fermentation parameters are often less than desirable. The objective of this study was to investigate the effects of management practices on the nutritive value and fermentation characteristics of bermudagrass silage. In Exp. 1, treatments were the factorial combinations of 2 bermudagrass genotypes, 'Jiggs' () and 'Tifton 85' ( sp.), 4 additives, and 2 DM concentrations at ensiling. The additives were 1) untreated control (deionized water), 2) Ecosyl, 3) B500, or 4) sugarcane molasses. The 2 DM concentrations at ensiling were low DM (22% DM) or high DM (53% DM). Treatments were replicated 3 times in a completely randomized design. Silage treated with molasses had a lesser ( < 0.05) pH and greater ( < 0.01) lactate concentrations than the control, Ecosyl, and B500 in silage with low DM concentrations and greater ( < 0.01) in vitro true digestibility (IVTD) and lesser ( < 0.01) ADF concentrations than the other treatments at either DM concentration. Silage treated with B500 had the greatest ( < 0.01) aerobic stability, whereas that treated with molasses had the least aerobic stability. However, all treatments presented long aerobic stability (≥150 h). Jiggs had lesser ( < 0.01) ADF and NDF and NDF digestibility (NDFD) concentrations than Tifton 85 and Tifton 85 had greater ( < 0.01) IVTD than Jiggs in the silage with a high DM concentration. In Exp. 2, Jiggs silage treated with either molasses (20 g molasses [DM]/kg forage [as-fed basis]) or nothing (control, untreated silage) was fed to 16 beef heifers ( sp.) in individual drylot pens in a completely randomized design with 8 replicates for voluntary DMI, in vivo apparent DM digestibility, and NDFD evaluations. There were no differences ( = 0.36) among treatments in NDFD; however, there was a trend ( < 0.08) for greater in vivo apparent DM digestibility and DMI in heifers fed the molasses-treated silage. Microbial inoculants had decreased effects on Jiggs and Tifton 85 bermudagrass silage ensiled at a low DM concentration; however, adding molasses was an effective management practice to improve its nutritive value and fermentation characteristics.

Temperature- and pH-sensitive wearable materials for monitoring foot ulcers

Foot ulcers account for 15% of comorbidities associated with diabetes. Presently, no device allows the status of foot ulcers to be continuously monitored when patients are not hospitalized. In this study, we describe a temperature and a pH sensor capable of monitoring diabetic foot and venous leg ulcers developed in the frame of the seventh framework program European Union project SWAN-iCare (smart wearable and autonomous negative pressure device for wound monitoring and therapy). Temperature is measured by exploiting the variations in the electrical resistance of a nanocomposite consisting of multiwalled carbon nanotubes and poly(styrene-b-(ethylene-co-butylene)-b-styrene). The pH sensor used a graphene oxide (GO) layer that changes its electrical potential when pH changes. The temperature sensor has a sensitivity of ~85 Ω/°C in the range 25°C–50°C and a high repeatability (maximum standard deviation of 0.1% over seven repeated measurements). For a GO concentration of 4 mg/mL, the pH sensor has a sensitivity of ~42 mV/pH and high linearity (R2=0.99).

A breath sampling system assessing the influence of respiratory rate on exhaled breath composition

This work presents a computerized system to monitor mouth pressure, tidal volume, exhaled airflow, respiration rate and end-tidal partial pressure of CO2 during breath collection. The system was used to investigate the effect of different respiratory rates on the volatile organic compounds (VOCs) concentrations in exhaled breath. For this purpose, VOCs with well-defined biochemical pathways and different chemical and physical properties were selected as biomarkers related to metabolism (acetone and isopropyl alcohol), cholesterol synthesis (isoprene) and intestinal microflora activity (ethanol). Mixed breath was collected from a nominally healthy volunteer in resting conditions by filling a Nalophan bag. The subject followed a regimented breathing pattern at different respiratory rates (10, 30 and 50 breaths per minute). Results highlight that ventilation pattern strongly influences the concentration of the selected compounds. The proposed system allows exhaled breath to be collected also in patients showing dyspnea such as in case of chronic heart failure, asthma and pulmonary diseases.

Pressure mapping with textile sensors for compression therapy monitoring

Compression therapy is the cornerstone of treatment in the case of venous leg ulcers. The therapy outcome is strictly dependent on the pressure distribution produced by bandages along the lower limb length. To date, pressure monitoring has been carried out using sensors that present considerable drawbacks, such as single point instead of distributed sensing, no shape conformability, bulkiness and constraints on patient's movements. In this work, matrix textile sensing technologies were explored in terms of their ability to measure the sub-bandage pressure with a suitable temporal and spatial resolution. A multilayered textile matrix based on a piezoresistive sensing principle was developed, calibrated and tested with human subjects, with the aim of assessing real-time distributed pressure sensing at the skin/bandage interface. Experimental tests were carried out on three healthy volunteers, using two different bandage types, from among those most commonly used. Such tests allowed the trends of pressure distribution to be evaluated over time, both at rest and during daily life activities. Results revealed that the proposed device enables the dynamic assessment of compression mapping, with a suitable spatial and temporal resolution (20 mm and 10 Hz, respectively). In addition, the sensor is flexible and conformable, thus well accepted by the patient. Overall, this study demonstrates the adequacy of the proposed piezoresistive textile sensor for the real-time monitoring of bandage-based therapeutic treatments.

Serotonin transporter gene polymorphism in eating disorders: Data from a new biobank and META-analysis of previous studies

Objectives Growing interest focuses on the association between 5-HTTLPR polymorphism and eating disorders (ED), but published findings have been conflicting. Methods The Italian BIO.VE.D.A. biobank provided 976 samples (735 ED patients and 241 controls) for genotyping. We conducted a literature search of studies published up to 1 April 2015, including studies reporting on 5HTTLPR genotype and allele frequencies in obesity and/or ED. We ran a meta-analysis, including data from BIO.VE.D.A. - comparing low and high-functioning genotype and allele frequencies in ED vs.

CONTROLS

Results Data from 21 studies, plus BIO.VE.D.A., were extracted providing information from 3,736 patients and 2,707 controls. Neither low- nor high-functioning genotype frequencies in ED patients, with both bi- and tri-allelic models, differed from controls. Furthermore, neither low- nor high-functioning allele frequencies in ED or in BN, in both bi- and triallelic models, differed from control groups. After sensitivity analysis, results were the same in AN vs.

CONTROLS

Results remained unaltered when investigating recessive and dominant models. Conclusions 5HTTLPR does not seem to be associated with ED in general, or with AN or BN in particular. Future studies in ED should explore the role of ethnicity and psychiatric comorbidity as a possible source of bias.

A D-optimal design to model the performances of dressings and devices for negative pressure wound therapy

A D-optimal design was used to identify and model variables that affect the transit time of wound exudate through an illustrative dressing used for negative pressure wound therapy. Many authors have addressed the clinical benefits of negative pressure wound therapy, but limited information is available on how to assess performances of dressings. In this paper, the transit time of wound exudate through a dressing was chosen as a model parameter to show how experimental design (DOE) can be used for this purpose. Results demonstrated that rate of exudate production, temperature and dressing thickness were the variables with the largest impact on transit time. The DOE approach could be used to model other dressing properties, like for example capability of absorbing excess exudate or breathability.

Correlation Between Wound Temperature Obtained With an Infrared Camera and Clinical Wound Bed Score in Venous Leg Ulcers

INTRODUCTION

The measurement of skin and wound bed temperature in chronic wounds may be a useful way to optimize the assessment and diagnosis of chronic wound infection. The aim of this clinical research trial was to correlate the wound bed score, validated by Falanga in 2006, to wound bed and perilesional skin temperature with an easy-to-use, handheld, noninvasive thermometer.

MATERIALS AND METHODS

In this study, the authors recruited 18 patients affected by venous insufficiency and lower leg ulcers. A total of 24 chronic wound bed and perilesional skin ulcers were assessed using an infrared camera (FLIR T620 Thermal Imager, FLIR Systems Boston, MA). At the same visit, an operator blinded to the thermal image results made a wound bed score to make a clinical evaluation of the lesion.

RESULTS

The wound bed temperature range after dressing removal was between 31°C and 35°C, and the perilesional skin temperature range was between 31°C and 34°C. The wound bed score range was between 5-14 (14 patients > 10; 11 patients ≤ 10). The study data showed an increasing relationship between the wound bed score and the wound bed temperature according to several studies that have demonstrated 33°C is the critical temperature level required for normal cellular activity. The correlation between the wound bed score and the perilesional skin temperature is weaker compared to other measurements.

CONCLUSION

The results obtained in this preliminary research suggest that this correlation is worth being further investigated with a larger dataset.

A dual mode breath sampler for the collection of the end-tidal and dead space fractions

This work presents a breath sampler prototype automatically collecting end-tidal (single and multiple breaths) or dead space air fractions (multiple breaths). This result is achieved by real time measurements of the CO2 partial pressure and airflow during the expiratory and inspiratory phases. Suitable algorithms, used to control a solenoid valve, guarantee that a Nalophan(®) bag is filled with the selected breath fraction even if the subject under test hyperventilates. The breath sampler has low pressure drop (<0.5 kPa) and uses inert or disposable components to avoid bacteriological risk for the patients and contamination of the breath samples. A fully customisable software interface allows a real time control of the hardware and software status. The performances of the breath sampler were evaluated by comparing (a) the CO2 partial pressure calculated during the sampling with the CO2 pressure measured off-line within the Nalophan(®) bag; (b) the concentrations of four selected volatile organic compounds in dead space, end-tidal and mixed breath fractions. Results showed negligible deviations between calculated and off-line CO2 pressure values and the distributions of the selected compounds into dead space, end-tidal and mixed breath fractions were in agreement with their chemical-physical properties.

Fabrication and functionalization of PCB gold electrodes suitable for DNA-based electrochemical sensing

The request of high specificity and selectivity sensors suitable for mass production is a constant demand in medical research. For applications in point-of-care diagnostics and therapy, there is a high demand for low cost and rapid sensing platforms. This paper describes the fabrication and functionalization of gold electrodes arrays for the detection of deoxyribonucleic acid (DNA) in printed circuit board (PCB) technology. The process can be implemented to produce efficiently a large number of biosensors. We report an electrolytic plating procedure to fabricate low-density gold microarrays on PCB suitable for electrochemical DNA detection in research fields such as cancer diagnostics or pharmacogenetics, where biosensors are usually targeted to detect a small number of genes. PCB technology allows producing high precision, fast and low cost microelectrodes. The surface of the microarray is functionalized with self-assembled monolayers of mercaptoundodecanoic acid or thiolated DNA. The PCB microarray is tested by cyclic voltammetry in presence of 5 mM of the redox probe K3Fe(CN6) in 0.1 M KCl. The voltammograms prove the correct immobilization of both the alkanethiol systems. The sensor is tested for detecting relevant markers for breast cancer. Results for 5 nM of the target TACSTD1 against the complementary TACSTD1 and non-complementary GRP, MYC, SCGB2A1, SCGB2A2, TOP2A probes show a remarkable detection limit of 0.05 nM and a high specificity.

Stretchable biocompatible electronics by embedding electrical circuitry in biocompatible elastomers

Stretchable and curvilinear electronics has been used recently for the fabrication of micro systems interacting with the human body. The applications range from different kinds of implantable sensors inside the body to conformable electrodes and artificial skins. One of the key parameters in biocompatible stretchable electronics is the fabrication of reliable electrical interconnects. Although very recent literature has reported on the reliability of stretchable interconnects by cyclic loading, work still needs to be done on the integration of electrical circuitry composed of rigid components and stretchable interconnects in a biological environment. In this work, the feasibility of a developed technology to fabricate simple electrical circuits with meander shaped stretchable interconnects is presented. Stretchable interconnects are 200 nm thin Au layer supported with polyimide (PI). A stretchable array of light emitting diodes (LEDs) is embedded in biocompatible elastomer using this technology platform and it features a 50% total elongation.

BIOTEX--biosensing textiles for personalised healthcare management

Textile-based sensors offer an unobtrusive method of continually monitoring physiological parameters during daily activities. Chemical analysis of body fluids, noninvasively, is a novel and exciting area of personalized wearable healthcare systems. BIOTEX was an EU-funded project that aimed to develop textile sensors to measure physiological parameters and the chemical composition of body fluids, with a particular interest in sweat. A wearable sensing system has been developed that integrates a textile-based fluid handling system for sample collection and transport with a number of sensors including sodium, conductivity, and pH sensors. Sensors for sweat rate, ECG, respiration, and blood oxygenation were also developed. For the first time, it has been possible to monitor a number of physiological parameters together with sweat composition in real time. This has been carried out via a network of wearable sensors distributed around the body of a subject user. This has huge implications for the field of sports and human performance and opens a whole new field of research in the clinical setting.

[Relationship between late ventricular potentials and ventricular arrhythmias in patients in chronic dialysis treatment]

BACKGROUND

Arrhythmias are frequent pathology in patients with chronic hemodialysis. We evaluated whether a relatively new technique, signal averaging, could be useful in predicting the development of complex arrhythmias in these patients.

METHODS

Thirty-three patients, 18 male and 15 female, subjected to thrice weekly chronic hemodialytic treatment with various dialysis techniques, were studied. Exclusion criteria were the presence of antiarrhythmic and inotropic treatment. The following examinations were carried out in all patients: a Holter dynamic electrocardiography for a duration of 24 hours, begun on the day of dialysis, high resolution ECG pre- and post-dialysis to find out if there were any ventricular late potential (VLP). Four hundred beats were examined in order to obtain a background noise of less than 0.7 microV and a better definition of the signal. The following parameters were considered significant for the presence of VLP: a) filtered QRS duration > 120 msec; b) the root mean square of the signal expressed in the terminal portion of QRS (RMS) < 25 microV) high frequency low amplitude signals duration (HFLA) > 40 msec. A positive value in two of these parameters was considered indicative of the presence of VLP. In addition various pre and post-dialysis indices of dialytic efficiency and a mono and two-dimensional echocardiogram with pulsed and color Doppler were carried out. Of the 33 patients studied, ten were excluded because they presented too high a background noise at the high resolution ECG. Of the remaining 23 patients, 13 (56%) presented VLP and nine of these (69%) presented complex arrhythmias. Of the ten patients without VLP, 5 (50%) presented complex arrhythmias. The incidence of arrhythmias was highest during the last two hours of dialysis and in the two hours following it. The patients were then divided into two groups (A and B) according to the ejection fraction (EF) found at the echocardiogram. Group A was composed of 17 patients of whom 8 (47%) presented complex arrhythmias; group B (EF < 45%) was composed of the remaining six patients, who all presented complex arrhythmias. In group A nine patients (53%) out of 17 had LVP, in group B four out of six (66%) had it. All the patients except one presented an increase in the thickness of the ventricular wall and alterations of Doppler transmitral filling rate. Left ventricular hypertrophy was diagnosed in 22 out of the 23 patients. Four patients also had chronic ischaemic heart disease; of these three had LVP. There was no correlation between the presence of LVP and the hemodialytic indices and between the latter and complex arrhythmias.

CONCLUSIONS

Our study showed that arrhythmias are more frequent in patients with LVP before dialysis than in those without. The difference was statistically significant (p < 0.006); the incidence of arrhythmias was higher in patients with FE < 45% (p < 0.001). The majority of patients (95%) had left ventricular hypertrophy; only four (17%) had ischaemic heart disease too. It is highly probable that the presence of LVP in our patients can be attributed to hypertension and subsequent left ventricular hypertrophy. As patients with LVP at the end of dialysis had a greater incidence of arrhythmias than those without LVP, we suggest that this method could be useful as a first screening in dialysed patients.

Planimetry study of the percent of body surface represented by the hand and palm: sizing irregular burns is more accurately done with the palm

Sizing irregular burns is commonly done with use of the patient's hand as a template representing 1% of the body surface. To verify that this is accurate over a broad range of ages or to see if the surface of the palm is a more consistent template, a planimetry study was done. This revealed that the surface area of the palm averaged 0.52% total body surface area (+/- 0.07) and the palmar surface of the hand 0.85% total body surface area (+/- 0.08). The surface of the palm was a more consistent template and represented 0.5% of the body surface over a broad range of ages.

Prevalence and incidence of schizophrenic disorders in Portogruaro. An Italian case register study

The authors report a study of treated prevalence and incidence of schizophrenic and related functional psychoses in an area of northeastern Italy (Portogruaro), based on case-register data. Point, 1-year, and lifetime prevalence as well as incidence rates on the adult population for a broad ICD-9 diagnosis of schizophrenia are given. Data over an 8-year period show the incidence around .2/1000, point prevalence around 1.4, 1-year prevalence of 2.7, and lifetime prevalence around 5.2. The rates peak in the 45 to 64 age group on all measures of prevalence. The implications of these findings are discussed in the light of methodological issues in epidemiological studies of schizophrenia and comparisons are made with figures from other countries.