Bioimpedance measurements in dentistry to detect inflammation: numerical modelling and experimental results

Bioimpedance measurements represent an advantageous method to evaluate the physio-pathological conditions of biological tissues and their use is spreading in different application fields, from the evaluation of body composition to the vital signs monitoring, passing through the individuation of cancer tissues and the detection of different substances (e.g. glucose measurements in people affected by diabetes). In fact, tissues electric properties vary with their conditions; for example, electrical conductivity increases when there is an inflammatory process, because of the presence of oedema, hyperaemia and infiltration. Inflammatory phenomena are frequent in dentistry, in diseases like periodontitis and peri-implantitis; however, at present the diagnosis is mainly done with the naked eye, by observing the gingiva redness and swelling.

OBJECTIVE

The aim of this work is to prove the feasibility of the inflammation detection by means of bioimpedance measurements.

APPROACH

Both numerical simulations and preliminary experimental measurements provide significant outcomes in differentiating between healthy and inflamed tissues.

MAIN RESULTS

Percentage differences in the impedance modulus equal to 4-20% (numerical simulations) and 35-56% (experimental measurements), respectively, depending on the considered conditions (e.g. electrodes characteristics and inflammation severity), were found.

SIGNIFICANCE

Such a measure could be integrated in electromedical devices designed, for example, for the therapy of peri-implantitis, in order to personalise the therapeutic dose in terms of intensity and duration and focusing it on the impaired area, minimising the effects on the surrounding tissues.

Key Histopathologic Features of Liver Biopsies That Distinguish Biliary Atresia From Other Causes of Infantile Cholestasis and Their Correlation With Outcome: A Multicenter Study

The liver biopsy guides diagnostic investigation and therapy in infants with undiagnosed cholestasis. Histologic features in the liver may also have prognostic value in the patient with biliary atresia (BA). We assessed the relative value of histologic features in 227 liver needle biopsies in discriminating between BA and other cholestatic disorders in infants enrolled in a prospective Childhood Liver Disease Research Network (ChiLDReN) cohort study by correlating histology with clinical findings in infants with and without BA. In addition, we reviewed 316 liver biopsies from clinically proven BA cases and correlated histologic features with total serum bilirubin 6 months after hepatoportoenterostomy (the Kasai procedure, HPE) and transplant-free survival up to 6 years. Review pathologists were blinded to clinical information except age. Semiquantitative scoring of 26 discrete histologic features was based on consensus. Bile plugs in portal bile ducts/ductules, moderate to marked ductular reaction, and portal stromal edema had the largest odds ratio for predicting BA versus non-BA by logistic regression analysis. The diagnostic accuracy of the needle biopsy was estimated to be 90.1% (95% confidence interval [CI]: 85.2%, 94.9%), whereas sensitivity and specificity for a diagnosis of BA are 88.4% (95% CI: 81.4, 93.5) and 92.7% (95% CI: 84.8, 97.3), respectively. No histologic features were associated with an elevated serum bilirubin 6 months after HPE, although it (an elevated serum bilirubin) was associated with an older age at HPE. Higher stages of fibrosis, a ductal plate configuration, moderate to marked bile duct injury, an older age at HPE, and an elevated international normalized ratio were independently associated with a higher risk of transplantation.

Blood fatty acid composition in relation to allergy in children aged 2-9 years: results from the European IDEFICS study

BACKGROUND/OBJECTIVES

Blood polyunsaturated fatty acids (PUFA) are involved in allergy development, but the etiological role of n-6 and n-3 PUFA is still controversial. A European multicenter study of children (IDEFICS) provided the opportunity to explore the cross-sectional association between fatty acids (FA) and allergy.

SUBJECTS/METHODS

Blood FA levels were measured in 2600 children aged 2-9 years and were recorded as the percentage of weight of all FA detected. Logistic regression of allergy status on FA components was adjusted for age, sex, country, body mass index, family history of allergic disease, breast-feeding, and number of siblings. The results were given as odds ratios (OR) for current vs no allergy ever and an increase in FA by 1 s.d.

RESULTS

Overall, higher proportions of n-6 PUFA were associated with higher odds of allergy (OR=1.21 (1.05, 1.40)). Monounsaturated FA (MUFA) were associated with reduced risk for allergy (OR=0.75 (0.65, 0.87)), whereas saturated FA did not differ by allergy status. The strongest associations were observed in children <4 years old, with ORs of allergy given as 1.62 (1.15, 2.29) for n-3 PUFA and 0.63 (0.42, 0.95) for MUFA. With regard to individual FA, these associations were independently observed for docosapentaenoic acid (22:5 n-3) and oleic acid (18:1 n-9).

CONCLUSIONS

Both PUFA subtypes were positively associated with allergy in an age-dependent manner, whereas MUFA was associated with less allergy. The observation of high proportions of n-3 PUFA in allergic children younger than 4 years might help to understand the nature of early onset of atopic disease.

In-line phase-contrast breast tomosynthesis: a phantom feasibility study at a synchrotron radiation facility

The major objective is to adopt, apply and test developed in-house algorithms for volumetric breast reconstructions from projection images, obtained in in-line phase-contrast mode. Four angular sets, each consisting of 17 projection images obtained from four physical phantoms, were acquired at beamline ID17, European Synchroton Radiation Facility, Grenoble, France. The tomosynthesis arc was  ±32°. The physical phantoms differed in complexity of texture and introduced features of interest. Three of the used phantoms were in-house developed, and made of epoxy resin, polymethyl-methacrylate and paraffin wax, while the fourth phantom was the CIRS BR3D. The projection images had a pixel size of 47 µm  ×  47 µm. Tomosynthesis images were reconstructed with standard shift-and-add (SAA) and filtered backprojection (FBP) algorithms. It was found that the edge enhancement observed in planar x-ray images is preserved in tomosynthesis images from both phantoms with homogeneous and highly heterogeneous backgrounds. In case of BR3D, it was found that features not visible in the planar case were well outlined in the tomosynthesis slices. In addition, the edge enhancement index calculated for features of interest was found to be much higher in tomosynthesis images reconstructed with FBP than in planar images and tomosynthesis images reconstructed with SAA. The comparison between images reconstructed by the two reconstruction algorithms shows an advantage for the FBP method in terms of better edge enhancement. Phase-contrast breast tomosynthesis realized in in-line mode benefits the detection of suspicious areas in mammography images by adding the edge enhancement effect to the reconstructed slices.

Frailty and Drug Use

Older adults often have co-occurring multiple chronic and acute diseases, which progressively and steadily increase in prevalence with age (1, 2). The treatment of these diseases usually requires multiple drugs (polypharmacy); it has been estimated that more than 50% of persons aged 65 years or older receive five or more drugs concomitantly (3, 4). Drug use in the older population might raise several concerns related to an increased risk of drug-drug and drug-disease interactions, poor adherence to treatment, and increased risk of adverse drug reactions (5-7). In this chapter we will discuss what role drugs and polypharmacy play in the development, management and treatment of frailty.

Cyclin T2A Gene Maps on Human Chromosome 2q21

Cyclin T2a was recently identified as one of the regulatory subunits of the cdk–cyclin complex P-TEFb, the most studied positive factor in the regulation of transcription elongation. By fluorescent in situ hybridization (FISH), the gene codifying for cyclin T2a has been mapped on human chromosome 2q21. This locus also has been linked to different forms of myopathy. By use of a new specific antiserum raised against cyclin T2a, the immunohistochemical pattern of expression of cyclin T2a in human tissues has been examined and compared to that of cyclin T1, described in the previous report. The observation that immunohistochemical expression of cyclin T2a was high in skeletal muscle cells, whereas it was undetectable in two cases of centronuclear myopathy, together with its chromosomal location, suggests an involvement of the cdk9–cyclin T2a complex in this disease.

Influence of physical fitness on cardio-metabolic risk factors in European children. The IDEFICS study

OBJECTIVE

The aim of the study was to assess the associations of individual and combined physical fitness components with single and clustering of cardio-metabolic risk factors in children.

SUBJECTS/METHODS

This 2-year longitudinal study included a total of 1635 European children aged 6-11 years. The test battery included cardio-respiratory fitness (20-m shuttle run test), upper-limb strength (handgrip test), lower-limb strength (standing long jump test), balance (flamingo test), flexibility (back-saver sit-and-reach) and speed (40-m sprint test). Metabolic risk was assessed through z-score standardization using four components: waist circumference, blood pressure (systolic and diastolic), blood lipids (triglycerides and high-density lipoprotein) and insulin resistance (homeostasis model assessment). Mixed model regression analyses were adjusted for sex, age, parental education, sugar and fat intake, and body mass index.

RESULTS

Physical fitness was inversely associated with clustered metabolic risk (P<0.001). All coefficients showed a higher clustered metabolic risk with lower physical fitness, except for upper-limb strength (β=0.057; P=0.002) where the opposite association was found. Cardio-respiratory fitness (β=-0.124; P<0.001) and lower-limb strength (β=-0.076; P=0.002) were the most important longitudinal determinants. The effects of cardio-respiratory fitness were even independent of the amount of vigorous-to-moderate activity (β=-0.059; P=0.029). Among all the metabolic risk components, blood pressure seemed not well predicted by physical fitness, while waist circumference, blood lipids and insulin resistance all seemed significantly predicted by physical fitness.

CONCLUSION

Poor physical fitness in children is associated with the development of cardio-metabolic risk factors. Based on our results, this risk might be modified by improving mainly cardio-respiratory fitness and lower-limb muscular strength.

Towards breast tomography with synchrotron radiation at Elettra: first images

The aim of the SYRMA-CT collaboration is to set-up the first clinical trial of phase-contrast breast CT with synchrotron radiation (SR). In order to combine high image quality and low delivered dose a number of innovative elements are merged: a CdTe single photon counting detector, state-of-the-art CT reconstruction and phase retrieval algorithms. To facilitate an accurate exam optimization, a Monte Carlo model was developed for dose calculation using GEANT4. In this study, high isotropic spatial resolution (120 μm)(3) CT scans of objects with dimensions and attenuation similar to a human breast were acquired, delivering mean glandular doses in the range of those delivered in clinical breast CT (5-25 mGy). Due to the spatial coherence of the SR beam and the long distance between sample and detector, the images contain, not only absorption, but also phase information from the samples. The application of a phase-retrieval procedure increases the contrast-to-noise ratio of the tomographic images, while the contrast remains almost constant. After applying the simultaneous algebraic reconstruction technique to low-dose phase-retrieved data sets (about 5 mGy) with a reduced number of projections, the spatial resolution was found to be equal to filtered back projection utilizing a four fold higher dose, while the contrast-to-noise ratio was reduced by 30%. These first results indicate the feasibility of clinical breast CT with SR.

Energy response of GR-200A thermoluminescence dosemeters to 60Co and to monoenergetic synchrotron radiation in the energy range 28-40 keV

The response of LiF:Mg,Cu,P thermoluminescence dosemeters (type GR-200A) to monoenergetic radiation of energy 28, 35, 38 and 40 keV was evaluated with respect to irradiation with a calibrated (60)Co gamma-ray source. High-precision measurements of the relative air kerma response performed at the SYRMEP beamline of the ELETTRA synchrotron radiation facility (Trieste, Italy) showed a significant deviation of the average response to low-energy X-rays from that to (60)Co, with an over-response from 6 % (at 28 keV) to 22 % (at 40 keV). These data are not consistent with literature data for these dosemeters, where model predictions gave deviation from unity of the relative air kerma response of about 10 %. The authors conclude for the need of additional determinations of the low-energy relative response of GR-200A dosemeters, covering a wider range of monoenergetic energies sampled at a fine energy step, as planned in future experiments by their group at the ELETTRA facility.

Negative symptoms as key features of depression among cannabis users: a preliminary report

OBJECTIVE

Cannabis use is frequent among depressed patients and may lead to the so-called "amotivational syndrome", which combines symptoms of affective flattening and loss of emotional reactivity (i.e. the so-called "negative" symptomatology). The aim of this study was to investigate the negative symptomatology in depressed patients with concomitant cannabis use disorders (CUDs) in comparison with depressed patients without CUDs.

PATIENTS AND METHODS

Fifty-one patients with a diagnosis of Major Depressive Disorder (MDD) and concomitant CUD and fifty-one MDD patients were enrolled in the study. The 21-Item Hamilton Depression Rating Scale (HDRS) and the negative symptoms subscales of the Positive and Negative Syndrome Scale (PANSS) were used to assess depressive and negative symptomatology.

RESULTS

Patients with cannabis use disorders presented significantly more severe negative symptoms in comparison with patients without cannabis use (15.18 ± 2.25 vs 13.75 ± 2.44; t100 = 3.25 p = 0.002).

DISCUSSION

A deeper knowledge of the "negative" psychopathological profile of MDD patients who use cannabis may lead to novel etiopathogenetic models of MDD and to more appropriate treatment approaches.

Adherence to combined lifestyle factors and their contribution to obesity in the IDEFICS study

BACKGROUND

The Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study investigated the aetiology of childhood obesity and developed a primary prevention programme.

METHODS

Pre-intervention adherence to key behaviours related to childhood obesity, namely water/sweetened drink, fruit/vegetable consumption, daily TV time, physical activity, family time and adequate sleep duration, was measured at baseline. Adherence to international recommendations was converted into a composite score ranging from 0 (none) to 6 (adhering to all). Data on adherence were available for 7,444 to 15,084 children aged 2-9.9 years, depending on the behaviour. By means of multi-level logistic regression models adjusted for age, sex and country, we calculated odds ratios (OR) and 95% confidence intervals (CI) to estimate the relationship between adherence to these recommendations and the risk of being overweight/obese.

RESULTS

Adherence ranged from 15.0% (physical activity) to 51.9% (TV time). As adherence increased, a lower chance of being overweight/obese was observed; adhering to only one key behaviour (score = 1) meant an OR = 0.81 (CI: 0.65-1.01) compared with non-adherence (score = 0), while adhering to more than half of the key behaviours (score ≥ 4) halved the chance for overweight/obesity (OR = 0.54, CI: 0.37-0.80). Adherence to physical activity, TV and sleep recommendations was the main driver reducing the chance of being overweight. Overweight/obese children were more likely not to adhere to at least one of the recommended behaviours (19.8%) than normal-weight/thin children (12.9%)

CONCLUSION

The selected key behaviours do not contribute equally to a reduced chance of being overweight. Future interventions may benefit most from moving more, reducing TV time and getting adequate sleep.

Impact of a community based health-promotion programme in 2- to 9-year-old children in Europe on markers of the metabolic syndrome, the IDEFICS study

INTRODUCTION

One objective of 'Identification and prevention of Dietary-and lifestyle-induced health EFfects In Children and infantS', the IDEFICS study, was to implement a community-oriented childhood obesity prevention intervention in eight European countries.

OBJECTIVE

To assess the effect of an obesity primary prevention programme on metabolic markers.

METHODS

The study had a non-randomized cluster-experimental design. In each country, children were recruited from distinct communities serving as intervention and control regions. Health examinations were done during 2007-2008 before the intervention (T0 ) and during 2009-2010 (T1 ). Children with results available from T0 and T1 on blood pressure, waist circumference and at least one blood-marker (fasting glucose, insulin, HOMA-IR, HbA1c, HDL- and LDL-cholesterol, triglycerides, C-reactive protein) were included. A metabolic syndrome (MetS) score was calculated.

RESULTS

A total of 7,406 children (age 2-9.9 years) of the 16,228 participating at T0 provided the necessary data. No effect of the intervention was seen on insulin, HOMA-IR, CRP or the MetS score. Overall fasting glucose increased less in the intervention than in the control region, a pattern driven by three of the eight countries and more pronounced in children of parents with low education. Overall, HbA1c and waist circumference increased more and blood pressure less in the intervention regions.

CONCLUSION

We observed no convincing effect of the intervention on markers of the metabolic syndrome. We identified diverse patterns of change for several markers of uncertain relation to the intervention.