Active video games and weight management in overweight children and adolescents-systematic review and meta-analysis.

BACKGROUND: The prevalence of childhood obesity has been increasing for several decades. Active video games (AVG) may be an effective intervention to help manage this rising health crisis. The aim of this review is to evaluate whether AVG are effective at reducing weight or improving body composition in overweight youths. METHOD: Medline, Embase, SportDiscus, ASSIA, CINAHL Plus, CENTRAL, CDSR and PsychINFO databases were searched for studies assessing quantitative or qualitative impact of AVG in overweight adolescents published in English. Three authors screened the results using inclusion/exclusion criteria. RESULTS: A total of 12 studies met the inclusion criteria; 11 reported a significant decrease in at least one weight outcome. Results from seven randomized controlled trials were pooled by meta-analysis, which compared with controls subjects in AVG groups demonstrated greater body mass index (BMI) Z-score reduction (mean difference: -0.09 (-0.12, -0.05) I2 = 34%, P < 0.0001). The mean weight reduction (-2.66 Kg (-5.67, +0.35) I2 = 0%, P = 0.08) and BMI (-2.29 (-4.81, +0.22) I2 = 49%, P = 0.07) were greater in AVG groups but results did not reach statistical significance. CONCLUSIONS: BMI Z-score was significantly reduced in the AVG group and the majority of included studies reported significant results in at least one weight outcome, suggesting AVG can be used to reduce weight or improve body composition in overweight youths. Further studies investigating the long-term sustainability of this change in body composition are needed.

Health status in Europe: comparison of 24 urban areas to the corresponding 10 countries (EURO-URHIS 2).

Background: : In Europe, over 70% of the population live in urban areas (UAs). Most international comparative health research is done using national level data, as reliable and comparable urban data are often unavailable or difficult to access. This study aims to investigate whether population health is different in UAs compared with their corresponding countries. : Routinely available health-related data were collected by the EURO-URHIS 2 project, for 10 European countries and for 24 UAs within those countries. National and UA level data for 11 health indicators were compared through the calculation of relative difference, and geographical patterns within Europe were investigated using the Mann Whitney U test. Linear regression modelling was used to adjust for population density, gross domestic product and urbanicity. : In general, the urban population in Eastern Europe is less healthy than the Western European urban population. However, people in Eastern Europe have significantly better broad health outcomes in UAs as compared with the corresponding country as a whole, whereas people in Western Europe have generally worse broader health outcomes in UAs. : For most European countries and UAs that were investigated, the national level health status data does not correspond with the health status at UA level. In order to identify health problems in UAs and to provide information for local health policy, health monitoring and international benchmarking should also be conducted at the local level.

Effect of weather conditions and presence of visitors on adrenocortical activity in captive African penguins (Spheniscus demersus).

A number of potential stressors are present in captive environments and it is critically important to identify them in order to improve health and welfare in ex situ animal populations. In this study, we investigated the adrenocortical activity of a colony of African penguins hosted in an immersive zoo in Italy, with respect to the presence of visitors and local microclimatic conditions, using the non-invasive method of assessing faecal glucocorticoid metabolites (FGMs). The penguins' exhibit is a large naturalistic outdoor enclosure, which closely reproduces the natural habitat of this species. Data collection took place from the beginning of June to the end of August 2014, during the period of maximum flow of visitors. We carried out 12 sampling periods, each involving 2 consecutive days; during the first day we counted the visitors and we registered the meteorological data, and on the second day, we collected the faecal samples, which amounted to a total of 285 faecal samples. Our results showed that the number of visitors did not influence the adrenocortical activity of the African penguins. Conversely, the local microclimatic conditions did influence the physiological stress on these birds. We found that an increase of the daily mean temperature induced a significant increase in FGM concentrations, although humidity and wind speed had a moderating effect on temperature and reduced the heat-induced stress. Moreover, we calculated two climatic indices, commonly used to assess the thermal discomfort in animals, namely the THI (Temperature-Humidity Index) and WCI (Wind Chill Index), and we detected a positive relationship between their values and the FGM levels, demonstrating that these indices could be useful indicators of weather discomfort in African penguins. Our study shows that the simulating naturalistic conditions could have significant benefits for zoo animals, such as reducing the negative effect of visitors. Nevertheless, it should be taken into account where the zoological facility is located and if the local microclimatic conditions are compatible with the hosted species, to ensure that they do not differ greatly from their natural habitat.

Knowledge, attitudes and behaviors of the Italian population towards Neisseria meningitidis, Streptococcus pneumoniae and HPV diseases and vaccinations: A cross-sectional multicentre study.

OBJECTIVES: This study addressed knowledge of Streptococcus pneumoniae, Neisseria meningitidis and human papillomavirus (HPV), and attitudes and behaviours towards vaccines against them. STUDY DESIGN: This is a cross-sectional, multicentre study. METHODS: Data were collected through a questionnaire administered to 530 adults who accessed four Departments of Prevention of the Italian National Health Service in 2013. RESULTS: Less than 50% of people gave the right answer to all the questions concerning the three diseases, but 96.2%, 94% and 92.7% agreed with the importance of vaccination against N. meningitidis, S. pneumoniae and HPV, respectively, and 58.4% expressed own willingness to have their children vaccinated with N. meningitidis B vaccine. The attitude towards vaccination was more positive in women for N. meningitidis and in people having children for HPV. Furthermore, individuals giving correct answers to all knowledge items were more in favour of both HPV and S. pneumoniae vaccination. A total of 68.8%, 82.6% and 84.5% of respondents vaccinated their own children against N. meningitidis C, S. pneumoniae and HPV, respectively. About 50% of the respondents reported paediatricians' or other health professionals' recommendations as the main reason for vaccination. CONCLUSIONS: Vaccinations may be promoted through actions aimed at increasing citizens' knowledge. Health professionals should be educated to actively provide information on vaccinations in a clear, comprehensive and effective way.

Validation of a qualitative immunochromatographic test for the noninvasive assessment of stress in dogs.

Salivary cortisol is regarded as a reliable parameter for the noninvasive assessment of the welfare of animals, because it is strictly related to stress levels. Several methods are available for salivary cortisol measurement in mammals, however rapid diagnostic test for detecting salivary cortisol are confined to humans. The availability of such non invasive diagnostic tools operable in situ would facilitate monitoring of animal welfare. The Cortisol stress™ test provides a simple and rapid tool to discriminate cortisol levels in canine saliva above or below 4ng/ml, which has been suggested as the cut-off value for distinguishing unstressed dogs from those experiencing stress. The test is based on a competitive immunochromatographic assay (ICT) using gold nanoparticles as probes, in which the color intensity of the Test line is inversely correlated to the salivary cortisol level. The qualitative result is obtained by the visual observation of the color formed on the Test line compared to that of the Control line We evaluated the accuracy of the test by determining salivary cortisol in 85 samples of canine saliva belonging to dogs with very variable age, sex, breed, and life history, and comparing the qualitative results to those obtained by a reference ELISA kit. Agreeing results were obtained through the two methods, and the ICT showed high diagnostic sensitivity, specificity and efficiency (100%, 98.4%, and 98.8%, respectively). Furthermore, we evaluated the precision of the test by an experimental design approach, which combines errors due to within-day and between-day variation with the biological variability, and demonstrated that the test could be reliably applied for correctly classifying canine samples, according to their salivary cortisol level. Moreover, we studied the shelf-life of the device in three experimental conditions. We confirmed the stability of the ICT at 4°C and 25°C for at least six months and observed similar results for an accelerated stability study conducted for 7days at 37°C, which suggest that the stability of ICT device could be estimated by the accelerated experiment alternatively to the real-time study.

Automatic Identification of the Repolarization Endpoint by Computing the Dominant T-wave on a Reduced Number of Leads.

Electrocardiographic (ECG) T-wave endpoint (Tend) identification suffers lack of reliability due to the presence of noise and variability among leads. Tend identification can be improved by using global repolarization waveforms obtained by combining several leads. The dominant T-wave (DTW) is a global repolarization waveform that proved to improve Tend identification when computed using the 15 (I to III, aVr, aVl, aVf, V1 to V6, X, Y, Z) leads usually available in clinics, of which only 8 (I, II, V1 to V6) are independent. The aim of the present study was to evaluate if the 8 independent leads are sufficient to obtain a DTW which allows a reliable Tend identification. To this aim Tend measures automatically identified from 15-dependent-lead DTWs of 46 control healthy subjects (CHS) and 103 acute myocardial infarction patients (AMIP) were compared with those obtained from 8-independent-lead DTWs. Results indicate that Tend distributions have not statistically different median values (CHS: 340 ms vs. 340 ms, respectively; AMIP: 325 ms vs. 320 ms, respectively), besides being strongly correlated (CHS: ρ=0.97, AMIP: 0.88; P<10(-27)). Thus, measuring Tend from the 15-dependent-lead DTWs is statistically equivalent to measuring Tend from the 8-independent-lead DTWs. In conclusion, for the clinical purpose of automatic Tend identification from DTW, the 8 independent leads can be used without a statistically significant loss of accuracy but with a significant decrement of computational effort. The lead dependence of 7 out of 15 leads does not introduce a significant bias in the Tend determination from 15 dependent lead DTWs.

A fluorescent immunochromatographic strip test using Quantum Dots for fumonisins detection.

A fluorescent immunochromatographic strip test (ICST) based on the use of Quantum Dots (QD) was developed and applied to detect fumonisins in maize samples. A limit of detection for fumonisin B1 of 2.8 µg L(-1) was achieved, with an analytical working range of 3-350 µg L(-1), corresponding to 30-3500 µg kg(-1) in maize flour samples, according with the extraction procedure. The time required to perform the analysis was 22 min, including sample preparation. Recovery values in the range from 91.4% to 105.4% with coefficients of variation not exceeding 5% were obtained for fortified and naturally contaminated maize flour samples. To evaluate the possible improvements due to the use of QD for ICST technology, we performed a direct comparison of the proposed QD-ICST to a gold nanoparticles- and a chemiluminescent-ICST previously developed for fumonisins detection, in which the same immunoreagents were employed.

A markerless system based on smartphones and webcam for the measure of step length, width and duration on treadmill.

BACKGROUND AND OBJECTIVE: A markerless low cost prototype has been developed for the determination of some spatio-temporal parameters of human gait: step-length, step-width and cadence have been considered. Only a smartphone and a high-definition webcam have been used. METHODS: The signals obtained by the accelerometer embedded in the smartphone are used to recognize the heel strike events, while the feet positions are calculated through image processing of the webcam stream. Step length and width are computed during gait trials on a treadmill at various speeds (3, 4 and 5 km/h). RESULTS: Six subjects have been tested for a total of 504 steps. Results were compared with those obtained by a stereo-photogrammetric system (Elite, BTS Engineering). The maximum average errors were 3.7 cm (5.36%) for the right step length and 1.63 cm (15.16%) for the right step width at 5 km/h. The maximum average error for step duration was 0.02 s (1.69%) at 5 km/h for the right steps. CONCLUSION: The system is characterized by a very high level of automation that allows its use by non-expert users in non-structured environments. A low cost system able to automatically provide a reliable and repeatable evaluation of some gait events and parameters during treadmill walking, is relevant also from a clinical point of view because it allows the analysis of hundreds of steps and consequently an analysis of their variability.

The surface electromyographic evaluation of the Functional Reach in elderly subjects.

This study proposes a comprehensive assessment of myoelectric activity of the main muscles involved in the Functional Reach (FR) test, in 24 elderly subjects. A specific protocol for the surface electromyography (sEMG) signal acquisition during FR-test was developed. Results show that anterior muscles activate following a caudo-cranial order. Tibialis Anterior (TA) is the first to be activated (-18.0±16.3% of the FR-period), together with Rectus Femoris (-10.4±17.9%). Then, Rectus Abdominis (19.7±24.7%) and Sternocleidomastoideus (19.9±15.6%) activate after the FR-start. Hamstrings, Soleus, and L4-level Erectores Spinae (posterior muscles) activate after the FR-start in this order (11.4±16.8%, 17.7±16.6%, and 35.2±29.0%, respectively) and remain active until the movement end. The analysis of the kinematic strategies adopted by subjects revealed an association between TA-activation patterns and two kinematic strategies (hip/mixed strategy), quantified by an increase (p<0.05) of TA-activity duration in subjects adopting the hip strategy (89.9±34.5) vs. subjects adopting the mixed strategy (27.0±16.8). This suggests that TA sEMG activity could be able to discriminate among kinematic strategies, providing different information on balance control. Thus, the present analysis represents the first attempt to quantify the sEMG activity during FR-test in elderly subjects, providing an early contribution in building a reference frame for balance assessment in clinical context.

A non-invasive prevention program model for the assessment of osteoporosis in the early postmenopausal period: a pilot study on FRAX(®) and QUS tools advantages.

OBJECTIVE: The study analyses the performances of FRAX algorithm and quantitative ultrasound (QUS) tool in relationship to the dual-energy X-ray absorptiometry (DXA) categorization to identify patients at risk of osteoporosis during menopause and to reach new thresholds for recommending the first DXA examination. DESIGN: Retrospective cohort study. PATIENTS AND MEASUREMENTS: Two hundred eighty-two postmenopausal patients filled out a questionnaire which determined their FRAX index and performed a bone evaluation by QUS of the calcaneus to determine their stiffness index (SI). Thereafter, they underwent assessments by the gold-standard DXA bone examination. RESULTS: Statistically significant correlations were observed between FRAX (calculated without BMD) and both QUS and DXA diagnosis. FRAX mean indices of risk corresponding to the diagnosis of osteoporosis by QUS and DXA were similar. Receiver operating characteristic (ROC) curve analysis showed that both FRAX and QUS tests were sufficiently accurate in predicting the alteration of bone mineral composition. The ROC curves of QUS allowed us to identify, in our population, SI cutoff for normal patients (SI > 90.5) and for patients having osteoporosis (SI < 78.5). We selected a cutoff screening value from FRAX ROC curve for major clinical fracture (2.94). The following diagnostic algorithm demonstrated that the use of FRAX test alone has a sensitivity of 85.3 % and a specificity of 33.8 % while the use of QUS exam alone showed a sensitivity of 81.3 % and a specificity of 45.1 %. When considering the capacity of QUS exam in combination with FRAX test, the final algorithm showed a sensitivity of 69.4 % and a specificity of 57.7 %. CONCLUSIONS: The use of QUS test with adjusted cutoffs offers a similar performance to the FRAX test alone in terms of sensitivity. The combined use of the tests reduces the sensibility but increases the specificity and adds clinical information related to the bone status of the patient.

Muscle activation patterns related to diabetic neuropathy in elderly subjects: A Functional Reach Test study.

BACKGROUND: This study was designed to assess, in healthy elderly, non-neuropathic and neuropathic diabetic subjects, the activation patterns of the main muscles involved in the Functional Reach Test, a well-recognized method to identify elderly subjects at risk of balance impairments. METHODS: Surface electromyographic analysis of Sternocleidomastoideus, Rectus Abdominis, Erectores Spinae at L4 level, Rectus Femoris, Hamstrings, Tibialis Anterior and Soleus was performed in 10 healthy, 10 diabetic non-neuropathic and 10 diabetic neuropathic subjects. FINDINGS: Results showed that in every group the first motor is Tibialis Anterior, that is recruited before the start of the test. An earlier activation of Tibialis Anterior (P<0.05) was detected in diabetic neuropathic (ON at -24% of the test period), compared with healthy (-11%) and diabetic non-neuropathic (-13%) groups. A significant earlier activation of Sternocleidomastoideus and Rectus Abdominis was found in diabetic neuropathic group, only with respect to healthy subjects. No significant difference was found in Rectus Femoris, Soleus, Hamstrings an Erectores Spinae onset among the three groups. INTERPRETATION: Results suggest a trend of diabetic neuropathic patients in earlier anticipation of the activation of the anterior body-muscles. In particular, the earlier onset of Tibialis Anterior is likely to be performed to adjust the movement timing and to compensate for the delay in the recruitment of the motor units. This anticipation might be involved in the altered postural control with increased balance impairment detected in diabetic neuropathic patients, and thereby it might also be proposed as an index of neuropathy, evidenced in a simple and non-invasive manner.

Non-invasive monitoring of adrenocortical activity in captive African Penguin (Spheniscus demersus) by measuring faecal glucocorticoid metabolites.

Measurement of faecal glucocorticoid metabolites (FGMs) has become a useful and widely-accepted method for the non-invasive evaluation of stress in vertebrates. In this study we assessed the adrenocortical activity of five captive African Penguins (Spheniscus demersus) by means of FGM evaluation following a biological stressor, i.e. capture and immobilization. In addition, we detected individual differences in secretion of FGMs during a stage of the normal biological cycle of penguins, namely the breeding period, without any external or induced causes of stress. Our results showed that FGM concentrations peaked 5.5-8h after the induced stress in all birds, and significantly decreased within 30 h. As predictable, the highest peak of FGMs (6591 ng/g) was reached by the youngest penguin, which was at its first experience with the stressor. This peak was 1.8-2.7-fold higher compared to those of the other animals habituated to the stimulus. For the breeding period, our results revealed that the increase in FGMs compared to ordinary levels, and the peaks of FGMs, varied widely depending on the age and mainly on the reproductive state of the animal. The bird which showed the lowest peak (2518 ng/g) was an old male that was not in a reproductive state at the time of the study. Higher FGM increases and peaks were reached by the two birds which were brooding (male: 5552%, 96,631 ng/g; female: 1438%, 22,846 ng/g) and by the youngest bird (1582%, 39,700 ng/g). The impact of the reproductive state on FGM levels was unexpected compared to that produced by the induced stress. The EIA used in this study to measure FGM levels proved to be a reliable tool for assessing individual and biologically-relevant changes in FGM concentrations in African Penguin. Moreover, this method allowed detection of physiological stress during the breeding period, and identification of individual differences in relation to the reproductive status. The increase in FGM levels as a response to capture and immobilization suggests that the measured metabolites are appropriate indicators of adrenal activity in these birds.

The segmented-beat modulation method for ECG estimation.

Electrocardiographic (ECG) tracings corrupted by noise with frequency components in the ECG frequency band, may result useless unless appropriately processed. The estimation of the clean ECG from such recordings, however, is quite challenging; being linear filtering inappropriate. In the common situations in which the R peaks are detectable, template-based techniques have been proposed to estimate the ECG by a template-beat concatenation. However, such techniques have the major limit of not being able to reproduce physiological heart-rate and morphological variability. Thus, the aim of the present study was to propose the segmented-beat modulation method (SBMM) as the technique that overcomes such limit. The SBMM is an improved template-based technique that provides good-quality estimations of ECG tracings characterized by some heart-rate and morphological variability. It segments the template ECG beat into QRS and TUP segments and then, before concatenation, it applies a modulation/demodulation process to the TUP-segment so that the estimated-beat duration and morphology adjust to those of the corresponding original-beat. To test its performance, the SBMM was applied to 19 ECG tracings from normal subjects. There were no errors in estimating the R peak location, and the errors in the QRS and TUP segments were low (≤65 µV and ≤30 µV, respectively), with the former ones being significantly higher than the latter ones. Eventually, TUP errors tended to increase with increasing heart-rate variability (correlation coefficient: 0.59, P<;10(-2)). In conclusion, the new SBMM proved to be a useful tool for providing good-quality ECG estimations of tracings characterized by heart-rate and morphological variability.

A stereophotogrammetric-based method to assess spatio-temporal gait parameters on healthy and Parkinsonian subjects.

Generally, the study of gait requires the detection of successive heel contacts and toe-off instants. Traditional gait analysis methods obtain these gait events using dynamometric platforms together with stereophotogrammetric data. Usually, are kept valid only those walking trials where the subjects step on each platform by only one foot. For subjects suffering from walking impairments it is very difficult or sometimes impossible to walk naturally and step properly on the dynamometric platforms. The aim of the present study is to propose a new method to identify, in an automatic manner, the initial contact (IC) and the toe-off (TO) time instants using only stereophotogrammetric data and a classic gait analysis protocol. The assessment of spatio-temporal gait variables during natural walking is also performed. The study consisted in analyzing healthy and Parkinsonian elderly subjects. The reliability of the proposed stereophotogrammetric-based method was tested by direct comparison with the IC and TO instants determined by the dynamometric platform data. The absence of any statistically significant differences between the values estimated by the two different modalities, highlights the reliability of the proposed method in the assessment of these two gait events. Results underline, as expected, the reduction of walking velocity in pathological patients during free ambulation. The present study proposes this method as a valid alternative to the traditional technique that use dynamometric platforms to identify main gait events, for subjects unable to walk naturally and to step properly on the platforms.

Assessment of the activation patterns of the muscles involved in the FR test in diabetic neuropathic patients.

This study was designed to assess, in elderly neuropathic diabetic (DN) patients, the activation patterns of the main muscles involved in the Functional Reach (FR) Test, a well-recognized method to identify elderly subjects at risk of recurrent falls. Surface electromyographic (sEMG) analysis of Sternocleidomastoideus (Scm), Rectus Abdominis (RAbd), Erectores Spinae at L4 level (L4), Rectus Femoris (RF), Hamstrings (Ham), Tibialis Anterior (TA) and Soleus (Sol) was performed to this aim. Results in DN patients are compared with a control group (CH) of healthy age-matched subjects. In DN patients, TA is identified as the first muscle to be recruited (ON at -34% of the FR-period) before the movement start, in order to initiate the body forward displacement. RF is the first muscle to be recruited after TA and, togheter with RAbd, showed a progressive earlier onset from CH group. Sol and Ham (ON after the FR-start), followed by L4, act mainly as tonic muscles, opposing the movement and preventing falls. Compared to the CH group, the DN subjects show an anticipatory recruitment (-34%±6%) of TA, showing a statistically significant difference (p<;0.05) in comparison to CH group, together with the Scm activation. Results suggest a trend of DN patients in anticipating the activation of the anterior muscles of the body. This is likely due to an attempt to compensate the neuropathy-related proprioception dysfunction and to adjust the movement timing. In conclusion, the present study shows that sEMG is a suitable tool to deepen the interpretation of the FR-test execution and proposes the earlier start of TA as a possible element to identify the presence of neuropathy in diabetic subjects.

Evaluation of gender-related differences in co-contraction activity of shank muscles during gait.

This study aims to investigate the possible differences between genders in co-contractions of tibialis anterior (TA) and gastrocnemius lateralis (GL), during walking at self-selected speed. To this purpose, the statistical gait analysis (SGA) was performed on seven female (F-group) and seven male (M-group) adults. SGA is a recently developed methodology for the characterization of gait, by averaging spatiotemporal and electromyographic parameters over hundreds of strides per subject. Co-contractions were assessed as the overlapping periods between TA and GL activity. Results showed that four co-contraction intervals are present during gait cycle in both groups. No relevant differences between genders were detected in onset-offset time instants of co-activations or in their temporal length. On the contrary, significant differences were observed in the number of strides where each co-contraction happens (i.e. the occurrence frequency). All the four co-contraction intervals result significantly (p<;0.05) more recurrent in females compared to males. This outcome suggests a larger presence of co-contraction activity in females walking, related to a female tendency for a more complex muscular strategy during gait. These findings could be useful to better understand gender differences in walking mechanisms and to develop separated normal walking reference frames for males and females.

The GOCCLES® medical device is effective in detecting oral cancer and dysplasia in dental clinical setting. Results from a multicentre clinical trial.

The purpose of this study is to demonstrate that the GOCCLES® medical device allows proper autofluorescence examination of the oral mucosa in a dental care setting. This is a non-randomised multicentre clinical trial on consecutive patients at risk for oral cancer. Patients underwent a classical naked eye inspection of the oral cavity followed by autofluorescence examination wearing the GOCCLES® spectacles while the light from a dental curing light irradiated the oral mucosa. Lesions were defined as visible potentially malignant lesions and/or fluorescence loss areas. All persisting lesions underwent excisional or incisional biopsy. Sixty-one patients were enrolled. Data from 64 biopsies were analysed. Of the 62 lesions identified by the device, 31 were true positives. The device identified 31 of 32 true positive lesions. One lesion (an invasive carcinoma) was not visible to the naked eye. The device identified all lesions classified as moderate dysplasia to invasive cancer. In 56.7% of cases, true positive lesions showed greater extension when observed through the device. The GOCCLES® medical device allowed the direct visualisation of fluorescence loss in patients suffering from mild to severe dysplasia and in situ to invasive oral cancer. It allowed autofluorescence examination with each source of light used during the study. These results suggest that the role of the autofluorescence visualisation is that of a complementary inspection following naked eye examination when dealing with patients at risk for oral cancer. The device allows detection of otherwise invisible lesions and otherwise impossible complete resections.

Multi-analyte homogenous immunoassay based on quenching of quantum dots by functionalized graphene.

We propose a homogenous multi-analyte immunoassay based on the quenching of quantum dot (QD) fluorescence by means of graphene. Two QDs with emission maxima at 636 and 607 nm were bound to antibodies selective for mouse or chicken immunoglobulins, respectively, and graphene functionalized with carboxylic moieties was employed to covalently link the respective antigen. The antibody-antigen interaction led graphene close enough to QDs to quench the QD fluorescence by resonance energy transfer. The addition of free antigens that competed with those linked to graphene acted as a "turn-on" effect on QD fluorescence. Fluorescence emitted by the two QDs could be recorded simultaneously since the QDs emitted light at different wavelengths while being excited at the same wavelength and proved to be linearly correlated with free antigen concentration. The developed assay allows measuring both antigens over 2-3 orders of magnitude and showed estimated limits of detection in the nanomolar range. This approach is thus a promising universal strategy to develop homogenous immunoassays for diverse antigens (cells, proteins, low-molecular-mass analytes) in a multi-analyte configuration.

Increased sensitivity of lateral flow immunoassay for ochratoxin A through silver enhancement.

Silver nucleation on gold has been exploited for signal amplification and has found application in several qualitative and quantitative bio-sensing techniques, thanks to the simplicity of the method and the high sensitivity achieved. Very recently, this technique has been tentatively applied to improve the performance of gold-based immunoassays. In this work, the exploitation of the signal amplification due to silver deposition on gold nanoparticles has been first applied to a competitive lateral flow immunoassay (LFIA). The signal enhancement due to silver allowed us to strongly reduce the amount of the competitor and of specific antibodies employed to build an LF device for measuring ochratoxin A (OTA), thus permitting the attainment of a highly sensitive assessment of OTA contamination, with a sensitivity gain of more than 10-fold compared to the gold-based LFIA that used the same immunoreagents and to all previously reported LFIA for measuring OTA. In addition, a less sensitive "quantitative" LFIA could be established, by suitably tuning competitor and antibody amounts, which was characterized by reproducible and accurate OTA determinations (RSD% 6-12%, recovery% 82-117%). The quantitative system allowed a reliable OTA quantification in wines and grape musts at the microgram per liter level requested by the European legislation, as demonstrated by a highly results obtained through the quantitative silver-enhanced LFIA and a reference HPLC-FLD on 30 samples.

23-valent pneumococcal polysaccharide vaccine (PPV23) for the prevention of invasive pneumococcal diseases (IPDs) in the elderly: is it really effective?

INTRODUCTION: Incidence of invasive pneumococcal diseases (IPDs) in Italy is constantly increasing and that is particularly true among the elderly. 23-valent polysaccharide pneumococcal vaccine (PPV23) is recommended to this age group and offered in all Italian regions. However, efficacy of PPV23 on preventing IPDs is debated. We therefore performed a review of the most recent available meta-analyses in order to assess the efficacy of PPVs. METHODS: The literature search was conducted using PubMed and Scopus search engines. We used the following keywords: "pneumococcal", "polysaccharide", "vaccine", "efficacy", "elderly", "meta analysis". Only meta-analyses published in the last 7 years were selected. We examined the results of the selected meta-analyses and assessed their quality according to the PRISMA recommendations. RESULTS: The search returned 16 results in PubMed and 12 in Scopus: among them we selected 3 meta-analyses. According to our quality assessment, all meta-analyses showed generally positive results and almost all items of the PRISMA checklist were respected. However, the research protocol and the registration number were absent in all the 3 revisions and the flow-chart was not shown in Moberley's and Melegaro's works. In the study by Huss et al. the relative risk of developing IPDs among vaccinated subjects was 0.90 (95%CI: 0.46-1.77, I2 4.9%), indicating a very slight benefit after vaccination. This contrasts with the results of the Cochrane Review by Moberley et al., in which the PPVs showed a protective efficacy in reducing the risk of IPDs of 74% (OR 0.26, 95% CI: 0.15-0.46) with no statistical heterogeneity (I2 0%). Melegaro et al. found a reduction not statistically significant of the incidence of IPD of 65% (OR 0.35; 95% CI 0.08-1.49) among healthy elderly, while the global estimate of vaccine efficacy among high risk elderly was minimal (OR 0.80; 95% CI 0.22-2.88). CONCLUSIONS: Most of the studies suggest that the PPVs confer low protection against IPDs. Anyhow, their methodological heterogeneity does not allow definitive conclusions. While waiting to see the results of new trials about the efficacy of PPVs, in particular of PPV23, and the extension of the use of conjugate vaccine among the population over 65, stakeholders should be aware of the results of the meta-analyses discussed in this paper during the implementation of the vaccination programs for the elderly in Public Health.