A novel estimate of biological aging by multiple fitness tests is associated with risk scores for age-related diseases.

Introduction: Recent research highlights the need for a correct instrument for monitoring the individual health status, especially in the elderly. Different definitions of biological aging have been proposed, with a consistent positive association of physical activity and physical fitness with decelerated aging trajectories. The six-minute walking test is considered the current gold standard for estimating the individual fitness status in the elderly. Methods: In this study, we investigated the possibility of overcoming the main limitations of assessing fitness status based on a single measure. As a result, we developed a novel measure of fitness status based on multiple fitness tests. In 176 Sardinian individuals aged 51-80 years we collected the results of eight fitness tests to measure participants' functional mobility, gait, aerobic condition, endurance, upper and lower limb strength, and static and dynamic balance. In addition, the participants' state of health was estimated through validated risk scores for cardiovascular diseases, diabetes, mortality, and a comorbidity index. Results: Six measures contributing to fitness age were extracted, with TUG showing the largest contribution (beta = 2.23 SDs), followed by handgrip strength (beta = -1.98 SDs) and 6MWT distance (beta = -1.11 SDs). Based on fitness age estimates, we developed a biological aging measure using an elastic net model regression as a linear combination of the results of the fitness tests described above. Our newly developed biomarker was significantly associated with risk scores for cardiovascular events (ACC-AHA: r = 0.61; p = 0.0006; MESA: r = 0.21; p = 0.002) and mortality (Levine mortality score: r = 0.90; p = 0.0002) and outperformed the previous definition of fitness status based on the six-minute walking test in predicting an individual health status. Discussion: Our results indicate that a composite measure of biological age based on multiple fitness tests may be helpful for screening and monitoring strategies in clinical practice. However, additional studies are needed to test standardisation and to calibrate and validate the present results.

The use of biomimetic tools for water quality monitoring: passive samplers versus sentinel organisms.

To evaluate the performance of artificial and biological integrative sampling strategies, dissolved concentrations of polychlorinated biphenyl (PCBs) and metals (Cu and Mn) were measured with passive sampler devices (PSD) enclosing hydrophobic and chelating phases, and Asiatic clams were transplanted to a polluted area in the Rio de la Plata. Water concentrations based on PSD were compared with spot water samples collected at 0, 15, 32, and 63 days of exposition. PCBs and metals displayed linear accumulation kinetics both in PSDs and bivalves, but with different slopes. PCBs slopes were 2-27 times higher in bivalves (0.3-7.9 vs. 0.1-2.6 ng g-1 d-1 in PSDs) reflecting active filtration and uptake from particles, colloids, and dissolved phase, whereas metal slopes were 2.5-11 times lower in bivalves (0.04-0.18 vs. 0.10-2.00 µg g-1 d-1 in PSDs) suggesting metal bioregulation. Truly dissolved PCB concentrations from PSD (4.0-6.9 ng.l-1) represented average 13±4 % of PCB concentrations from filtered spot water samples reflecting the operational discrimination of the PSD diffusion membrane on competing dissolved and colloidal organic phases. In contrast, PSD dissolved Cu concentrations (2.3-8.2 µg l-1) were equivalent to the spot water values (3.2-3.8 µg l-1) suggesting that Cu speciation was adequately integrated by passive sampling. On the other hand, PSD-dissolved Mn concentrations (49±38 µg l-1) were higher (p<0.05) than those from spot water samples (7±11µg l-1) possibly due to phase changes of Mn distribution related to variable redox conditions in the water. Results evidenced that the PSDs are efficient accumulators of metals and organic compounds from the truly dissolved fraction.

Cortical thickness of primary visual cortex correlates with motion deficits in periventricular leukomalacia.

Impairments of visual motion perception and, in particular, of flow motion have been consistently observed in premature and very low birth weight subjects during infancy. Flow motion information is analyzed at various cortical levels along the dorsal pathways, with information mainly provided by primary and early visual cortex (V1, V2 and V3). We investigated the cortical stage of the visual processing that underlies these motion impairments, measuring Grey Matter Volume and Cortical Thickness in 13 children with Periventricular Leukomalacia (PVL). The cortical thickness, but not the grey matter volume of area V1, correlates negatively with motion coherence sensitivity, indicating that the thinner the cortex, the better the performance among the patients. However, we did not find any such association with either the thickness or volume of area MT, MST and areas of the IPS, suggesting damage at the level of primary visual cortex or along the optic radiation.

The effectiveness of extracorporeal shock wave therapy on breast cancer-related lymphedema: A literature review.

Lymphedema is one of the most dreaded complications related to breast cancer surgery, commonly resulting in upper limb functional, esthetic, and psychological impairment. The necessity to improve the efficacy of conventional treatments and the promising effect of extracorporeal shock wave therapy (ESWT) on lymphangiogenesis in vitro and animal models, has prompted studies involving women affected by breast cancer-related lymphedema. Since intervention modalities and treatment protocols used are different, a review is necessary to verify the effectiveness of ESWT, evaluating the quality of existing studies and the eventual need for further research. Data were obtained from PubMed, Scopus, Google Scholar, Cochrane Library and PEDro, including articles published until January 2019. Five studies met the inclusion criteria. Evident heterogeneity emerged among selected studies permitting only a purely descriptive analysis of their data and strongly limiting their comparison. When compared to other treatment modalities, ESWT showed a significant effect on measured outcomes. It is clear that further high quality research is necessary to assert with confidence the effects and possible superiority of ESWT over other conservative therapies in the management of breast cancer-related lymphedema.

Robotic hand treatment of patients affected by chronic stroke: a monocentric longitudinal pilot study.

Few studies investigated the effects of a robotic treatment in hand motor recovery after stroke. Aim of the present study was to evaluate the efficacy of treatment by means of Gloreha Sinfonia® robotic glove in hand motor recovery of a chronic stroke sample of patients with different impairment severity. Thirteen chronic stroke subjects were assigned to either active-assisted robotic treatment or passive robotic treatment according to their ability to actively extend wrist for at least 20 degrees. All subjects underwent 20 sessions of treatment with Gloreha Sinfonia® and were evaluated before (T0), after treatment (T1) and after one month (T2) with clinical scales testing motor performance [Motor Power (MP); Fugl Meyer Upper-Extremity (FMUE)] and spasticity [Modified Ashworth Scale (MAS)]. Both groups showed significant motor recovery and spasticity reduction. Further randomized controlled trials with larger samples are needed to confirm our results.

Plasticity of the human visual brain after an early cortical lesion.

In adults, partial damage to V1 or optic radiations abolishes perception in the corresponding part of the visual field, causing a scotoma. However, it is widely accepted that the developing cortex has superior capacities to reorganize following an early lesion to endorse adaptive plasticity. Here we report a single patient case (G.S.) with near normal central field vision despite a massive unilateral lesion to the optic radiations acquired early in life. The patient underwent surgical removal of a right hemisphere parieto-temporal-occipital atypical choroid plexus papilloma of the right lateral ventricle at four months of age, which presumably altered the visual pathways during in utero development. Both the tumor and surgery severely compromised the optic radiations. Residual vision of G.S. was tested psychophysically when the patient was 7 years old. We found a close-to-normal visual acuity and contrast sensitivity within the central 25° and a great impairment in form and contrast vision in the far periphery (40-50°) of the left visual hemifield. BOLD response to full field luminance flicker was recorded from the primary visual cortex (V1) and in a region in the residual temporal-occipital region, presumably corresponding to the middle temporal complex (MT+), of the lesioned (right) hemisphere. A population receptive field analysis of the BOLD responses to contrast modulated stimuli revealed a retinotopic organization just for the MT+ region but not for the calcarine regions. Interestingly, consistent islands of ipsilateral activity were found in MT+ and in the parieto-occipital sulcus (POS) of the intact hemisphere. Probabilistic tractography revealed that optic radiations between LGN and V1 were very sparse in the lesioned hemisphere consistently with the post-surgery cerebral resection, while normal in the intact hemisphere. On the other hand, strong structural connections between MT+ and LGN were found in the lesioned hemisphere, while the equivalent tract in the spared hemisphere showed minimal structural connectivity. These results suggest that during development of the pathological brain, abnormal thalamic projections can lead to functional cortical changes, which may mediate functional recovery of vision.

Urban geochemistry and potential human health risks in the Metropolitan Area of Buenos Aires: PAHs and PCBs in soil, street dust, and bulk deposition.

Soil, street dust, and bulk deposition (dry and wet deposition) were collected in the Metropolitan Area of Buenos Aires (MABA), Argentina, to assess the polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) pollution and the potential risks to human health. Compared with other countries, the mean concentration of PAHs and PCBs in surface soils, street dust and bulk deposition of MABA were at a low or moderate level. Average PAHs and PCBs concentrations in bulk deposition (5.7 ± 5.1 and 0.41 ± 0.25 µg g-1, respectively) were five and ten times higher than those of soil (1.08 ± 0.98 and 0.02 ± 0.01 µg g-1) and street dust (1.2 ± 0.95 and 0.04 ± 0.03 µg g-1), respectively. Different compositional profiles, observed in the three matrices for both groups of contaminants, could be attributed to dissimilar source contribution, partition processes between gas and particulate phases, and transformation. The most contaminated bulk deposition presented higher values for cancer and non-cancer risks relative to soil and street dust. In all matrices, non-carcinogenic risks were below the safety threshold (HI < 1). Regarding carcinogenic risks, exposure to both bulk deposition and soil indicated a moderated potential for cancerous development (Incremental lifetime cancer risk ~ 3.0 × 10-6).

Interactions between Proteins and the Membrane Surface in Multiscale Modeling of Organic Fouling.

In the present paper, an improved multiscale modeling aimed at describing membrane fouling in the UltraFiltration (UF) process was proposed. Some of the authors of this work previously published a multiscale approach to simulate ultrafiltration of Bovine Serum Albumin (BSA) aqueous solutions. However, the noncovalent interactions between proteins and the membrane surface were not taken into account in the previous formulation. Herein, the proteins-surface interactions were accurately computed by first-principle-based calculations considering also the effect of pH. Both the effective surface of polysulfone (PSU) and the first layer of proteins adsorbed on the membrane surface were accurately modeled. Different from the previous work, the equilibrium distance between proteins was calculated and imposed as lower bound to the protein-protein distances in the compact deposit accumulated on the membrane surface. The computed BSA surface charges were used to estimate the protein potential and the charge density, both necessary to formulate a forces balance at microscopic scale. The protein surface potential was compared with Z-potential measurements of BSA aqueous solution, and a remarkable agreement was found. Finally, the overall additional resistance, as due to both the compact and loose layers of the deposit, was computed, thus allowing the final transition to a macroscopic scale, where an unsteady-state mass transfer model was formulated to describe the behavior of a typical dead-end UF process. A good agreement between simulated and experimental permeate flux decays was observed.

Supramodal agnosia for oblique mirror orientation in patients with periventricular leukomalacia.

Periventricular leukomalacia (PVL) is characterized by focal necrosis at the level of the periventricular white matter, often observed in preterm infants. PVL is frequently associated with motor impairment and with visual deficits affecting primary stages of visual processes as well as higher visual cognitive abilities. Here we describe six PVL subjects, with normal verbal IQ, showing orientation perception deficits in both the haptic and visual domains. Subjects were asked to compare the orientation of two stimuli presented simultaneously or sequentially, using both a two alternative forced choice (2AFC) orientation-discrimination and a matching procedure. Visual stimuli were oriented gratings or bars or collinear short lines embedded within a random pattern. Haptic stimuli comprised two rotatable wooden sticks. PVL patients performed at chance in discriminating the oblique orientation, both for visual and haptic stimuli. Moreover when asked to reproduce the oblique orientation, they often oriented the stimulus along the symmetric mirror orientation. The deficit generalized to stimuli varying in many low level features, was invariant for spatiotopic object orientation, and also occurred for sequential presentations. The deficit was specific to oblique orientations, and not for horizontal or vertical stimuli. These findings show that PVL can affect a specific network involved with the supramodal perception of mirror symmetry orientation.

Perception during double-step saccades.

How the visual system achieves perceptual stability across saccadic eye movements is a long-standing question in neuroscience. It has been proposed that an efference copy informs vision about upcoming saccades, and this might lead to shifting spatial coordinates and suppressing image motion. Here we ask whether these two aspects of visual stability are interdependent or may be dissociated under special conditions. We study a memory-guided double-step saccade task, where two saccades are executed in quick succession. Previous studies have led to the hypothesis that in this paradigm the two saccades are planned in parallel, with a single efference copy signal generated at the start of the double-step sequence, i.e. before the first saccade. In line with this hypothesis, we find that visual stability is impaired during the second saccade, which is consistent with (accurate) efference copy information being unavailable during the second saccade. However, we find that saccadic suppression is normal during the second saccade. Thus, the second saccade of a double-step sequence instantiates a dissociation between visual stability and saccadic suppression: stability is impaired even though suppression is strong.

Visual BOLD Response in Late Blind Subjects with Argus II Retinal Prosthesis.

Retinal prosthesis technologies require that the visual system downstream of the retinal circuitry be capable of transmitting and elaborating visual signals. We studied the capability of plastic remodeling in late blind subjects implanted with the Argus II Retinal Prosthesis with psychophysics and functional MRI (fMRI). After surgery, six out of seven retinitis pigmentosa (RP) blind subjects were able to detect high-contrast stimuli using the prosthetic implant. However, direction discrimination to contrast modulated stimuli remained at chance level in all of them. No subject showed any improvement of contrast sensitivity in either eye when not using the Argus II. Before the implant, the Blood Oxygenation Level Dependent (BOLD) activity in V1 and the lateral geniculate nucleus (LGN) was very weak or absent. Surprisingly, after prolonged use of Argus II, BOLD responses to visual input were enhanced. This is, to our knowledge, the first study tracking the neural changes of visual areas in patients after retinal implant, revealing a capacity to respond to restored visual input even after years of deprivation.

Effects of adaptation on numerosity decoding in the human brain.

Psychophysical studies have shown that numerosity is a sensory attribute susceptible to adaptation. Neuroimaging studies have reported that, at least for relatively low numbers, numerosity can be accurately discriminated in the intra-parietal sulcus. Here we developed a novel rapid adaptation paradigm where adapting and test stimuli are separated by pauses sufficient to dissociate their BOLD activity. We used multivariate pattern recognition to classify brain activity evoked by non-symbolic numbers over a wide range (20-80), both before and after psychophysical adaptation to the highest numerosity. Adaptation caused underestimation of all lower numerosities, and decreased slightly the average BOLD responses in V1 and IPS. Using support vector machine, we showed that the BOLD response of IPS, but not in V1, classified numerosity well, both when tested before and after adaptation. However, there was no transfer from training pre-adaptation responses to testing post-adaptation, and vice versa, indicating that adaptation changes the neuronal representation of the numerosity. Interestingly, decoding was more accurate after adaptation, and the amount of improvement correlated with the amount of perceptual underestimation of numerosity across subjects. These results suggest that numerosity adaptation acts directly on IPS, rather than indirectly via other low-level stimulus parameters analysis, and that adaptation improves the capacity to discriminate numerosity.

Rhythmic modulation of visual contrast discrimination triggered by action.

Recent evidence suggests that ongoing brain oscillations may be instrumental in binding and integrating multisensory signals. In this experiment, we investigated the temporal dynamics of visual-motor integration processes. We show that action modulates sensitivity to visual contrast discrimination in a rhythmic fashion at frequencies of about 5 Hz (in the theta range), for up to 1 s after execution of action. To understand the origin of the oscillations, we measured oscillations in contrast sensitivity at different levels of luminance, which is known to affect the endogenous brain rhythms, boosting the power of alpha-frequencies. We found that the frequency of oscillation in sensitivity increased at low luminance, probably reflecting the shift in mean endogenous brain rhythm towards higher frequencies. Importantly, both at high and at low luminance, contrast discrimination showed a rhythmic motor-induced suppression effect, with the suppression occurring earlier at low luminance. We suggest that oscillations play a key role in sensory-motor integration, and that the motor-induced suppression may reflect the first manifestation of a rhythmic oscillation.

A low-cost and versatile system for projecting wide-field visual stimuli within fMRI scanners.

We have constructed and tested a custom-made magnetic-imaging-compatible visual projection system designed to project on a very wide visual field (~80°). A standard projector was modified with a coupling lens, projecting images into the termination of an image fiber. The other termination of the fiber was placed in the 3-T scanner room with a projection lens, which projected the images relayed by the fiber onto a screen over the head coil, viewed by a participant wearing magnifying goggles. To validate the system, wide-field stimuli were presented in order to identify retinotopic visual areas. The results showed that this low-cost and versatile optical system may be a valuable tool to map visual areas in the brain that process peripheral receptive fields.

Short-term monocular deprivation alters early components of visual evoked potentials.

KEY POINTS: Short-term monocular deprivation in adult humans produces a perceptual boost of the deprived eye reflecting homeostatic plasticity. Visual evoked potentials (VEPs) to transient stimuli change after 150 min of monocular deprivation in adult humans. The amplitude of the C1 component of the VEP at a latency of about 100 ms increases for the deprived eye and decreases for the non-deprived eye after deprivation, the two effects being highly negatively correlated. Similarly, the evoked alpha rhythm increases after deprivation for the deprived eye and decreases for the non-deprived eye. The data demonstrate that primary visual cortex excitability is altered by a short period of monocular deprivation, reflecting homeostatic plasticity. ABSTRACT: Very little is known about plasticity in the adult visual cortex. In recent years psychophysical studies have shown that short-term monocular deprivation alters visual perception in adult humans. Specifically, after 150 min of monocular deprivation the deprived eye strongly dominates the dynamics of binocular rivalry, reflecting homeostatic plasticity. Here we investigate the neural mechanisms underlying this form of short-term visual cortical plasticity by measuring visual evoked potentials (VEPs) on the scalp of adult humans during monocular stimulation before and after 150 min of monocular deprivation. We found that monocular deprivation had opposite effects on the amplitude of the earliest component of the VEP (C1) for the deprived and non-deprived eye stimulation. C1 amplitude increased (+66%) for the deprived eye, while it decreased (-29%) for the non-deprived eye. Source localization analysis confirmed that the C1 originates in the primary visual cortex. We further report that following monocular deprivation, the amplitude of the peak of the evoked alpha spectrum increased on average by 23% for the deprived eye and decreased on average by 10% for the non-deprived eye, indicating a change in cortical excitability. These results indicate that a brief period of monocular deprivation alters interocular balance in the primary visual cortex of adult humans by both boosting the activity of the deprived eye and reducing the activity of the non-deprived eye. This indicates a high level of residual homeostatic plasticity in the adult human primary visual cortex, probably mediated by a change in cortical excitability.

Comparative analysis and quantitative evaluation of ankle-foot orthoses for foot drop in chronic hemiparetic patients.

BACKGROUND: Ankle-foot-orthoses (AFOs) are frequently prescribed for hemiparetic patients to compensate for the foot drop syndrome. However, there is not a systematic study either on the effectiveness of AFOs in the gait recovery process or pointing out the therapeutic differences among the various types of AFOs available on the market. AIM: To perform a comparative evaluation of solid and dynamic Ankle-Foot-Orthoses (AFOs) on hemiparetic patients affected by foot drop syndrome by means of spatio-temporal, kinematic and electromyographic indicators. DESIGN: Crossover design with randomization for the interventions. SETTING: A rehabilitation center for adults with neurologic disorders. POPULATION: Ten chronic hemiparetic patients with foot drop syndrome met inclusion criteria and volunteered to participate. METHODS: Biomechanical gait analysis was carried out on hemiparetic subjects with foot drop syndrome under 3 conditions with randomized sequences: 1) without AFO; 2) wearing a solid AFO; 3) wearing a dynamic AFO. Significant changes in spatio-temporal, kinematic and electromyographic features of gait were investigated. RESULTS: Gait analysis outcomes showed that there were no significant differences among the solid and the dynamic AFO on the spatio-temporal parameters. Both AFOs led to a reduction of the range of motion of the ankle dorsi-plantar-flexion during stance with respect to the ambulation without AFO. They also had the effect of reducing the asymmetry between the paretic and the contralateral limb in terms of ankle angle at initial contact and hip flexion. The solid AFO generally led to an increase of the co-contraction of the couples of muscles involved in the gait. CONCLUSION: The proposed set of indicators showed that the AFOs were capable of limiting the effect of the foot-drop in hemiparetic patients and balancing the two limbs. Main differences between the two orthoses were related to muscular activity, being the level of co-contraction of the two couples of analysed muscles typically lower when the dynamic AFO was worn and closer to a normal pattern. CLINICAL REHABILITATION IMPACT: A more extensive use of the proposed indicators in the clinical practice is expected in order to enable the definition of clinical guidelines for the prescription of the two devices.

Evaluation of optoelectronic Plethysmography accuracy and precision in recording displacements during quiet breathing simulation.

Opto-electronic Plethysmography (OEP) is a motion analysis system used to measure chest wall kinematics and to indirectly evaluate respiratory volumes during breathing. Its working principle is based on the computation of marker displacements placed on the chest wall. This work aims at evaluating the accuracy and precision of OEP in measuring displacement in the range of human chest wall displacement during quiet breathing. OEP performances were investigated by the use of a fully programmable chest wall simulator (CWS). CWS was programmed to move 10 times its eight shafts in the range of physiological displacement (i.e., between 1 mm and 8 mm) at three different frequencies (i.e., 0.17 Hz, 0.25 Hz, 0.33 Hz). Experiments were performed with the aim to: (i) evaluate OEP accuracy and precision error in recording displacement in the overall calibrated volume and in three sub-volumes, (ii) evaluate the OEP volume measurement accuracy due to the measurement accuracy of linear displacements. OEP showed an accuracy better than 0.08 mm in all trials, considering the whole 2m(3) calibrated volume. The mean measurement discrepancy was 0.017 mm. The precision error, expressed as the ratio between measurement uncertainty and the recorded displacement by OEP, was always lower than 0.55%. Volume overestimation due to OEP linear measurement accuracy was always <; 12 mL (<; 3.2% of total volume), considering all settings.

The visual component to saccadic compression.

Visual objects presented around the time of saccadic eye movements are strongly mislocalized towards the saccadic target, a phenomenon known as "saccadic compression." Here we show that perisaccadic compression is modulated by the presence of a visual saccadic target. When subjects saccaded to the center of the screen with no visible target, perisaccadic localization was more veridical than when tested with a target. Presenting a saccadic target sometime before saccade initiation was sufficient to induce mislocalization. When we systematically varied the onset of the saccade target, we found that it had to be presented around 100 ms before saccade execution to cause strong mislocalization: saccadic targets presented after this time caused progressively less mislocalization. When subjects made a saccade to screen center with a reference object placed at various positions, mislocalization was focused towards the position of the reference object. The results suggest that saccadic compression is a signature of a mechanism attempting to match objects seen before the saccade with those seen after.

Buildup of spatial information over time and across eye-movements.

To interact rapidly and effectively with our environment, our brain needs access to a neural representation of the spatial layout of the external world. However, the construction of such a map poses major challenges, as the images on our retinae depend on where the eyes are looking, and shift each time we move our eyes, head and body to explore the world. Research from many laboratories including our own suggests that the visual system does compute spatial maps that are anchored to real-world coordinates. However, the construction of these maps takes time (up to 500ms) and also attentional resources. We discuss research investigating how retinotopic reference frames are transformed into spatiotopic reference-frames, and how this transformation takes time to complete. These results have implications for theories about visual space coordinates and particularly for the current debate about the existence of spatiotopic representations.

Spatial position information accumulates steadily over time.

One of the more enduring mysteries of neuroscience is how the visual system constructs robust maps of the world that remain stable in the face of frequent eye movements. Here we show that encoding the position of objects in external space is a relatively slow process, building up over hundreds of milliseconds. We display targets to which human subjects saccade after a variable preview duration. As they saccade, the target is displaced leftwards or rightwards, and subjects report the displacement direction. When subjects saccade to targets without delay, sensitivity is poor; but if the target is viewed for 300-500 ms before saccading, sensitivity is similar to that during fixation with a strong visual mask to dampen transients. These results suggest that the poor displacement thresholds usually observed in the "saccadic suppression of displacement" paradigm are a result of the fact that the target has had insufficient time to be encoded in memory, and not a result of the action of special mechanisms conferring saccadic stability. Under more natural conditions, trans-saccadic displacement detection is as good as in fixation, when the displacement transients are masked.