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Background: F2-isoprostanes are considered to be a reliable standard biomarker of oxidative stress in vivo because they are not influenced by the intake of lipids in the diet, and they are chemically stable molecules and easily detected. This study aimed to test the hypothesis that 8-isoprostane level is a useful marker to valuate the severity of pediatric obstructive sleep apnea (OSA)., Methods: Sixty-five children with sleep-disordered breathing (SDB) (mean age 5.9±2.0 years; 63.1% males) were recruited. The urine sample for the measurement of 8-isoprostane was collected the morning after the polysomnographic recording. Children were divided into two groups according to their apnea-hypopnea index (AHI)., Results: Urinary 8-isoprostane levels positively correlated with the sleep clinical record score (r=0.38, p=0.002) and AHI (r=0.24, p=0.05) and negatively correlated with age (r=-0.36, p=0.003) and body surface area (r=-0.38, p=0.002). Urinary 8-isoprostane levels were significantly higher in the group with AHI of ≥5 events (ev)/h than in the group with AHI of <5 ev/h (p<0.01)., Conclusions: Urinary 8-isoprostane may be used as a specific inflammatory marker to predict the severity of OSA; this method has the advantage of being noninvasive and easy to use in both compliant and noncompliant children.

1. The protective effect of a natural Brazilian calcium montmorillonite (CaMont) against aflatoxins was studied in broiler chickens. 2. A total of 1056-d-old Cobb male broilers were housed in experimental pens (22 chickens per pen) for 42 d. Three levels of CaMont (0, 2.5 and 5 g/kg) and two levels of aflatoxins (0 and 3 mg/kg) were assayed. Each treatment had 8 replicate pens of 22 broiler chickens each. 3. Of all the chickens tested in the experiment, the ones treated with aflatoxins were the most adversely affected. CaMont treatment at concentrations of 2.5 and 5 g/kg improved body weight of chickens at 42 d of age by 13.3% and 22.7%, increased daily feed intake by 9.7% and 24.7%, and improved the productive efficiency index of chickens by 53% and 66.5%, respectively. 4. Dietary CaMont positively affected parameters such as weight of liver, heart and gizzard; however, serum potassium concentration decreased by 15.3% compared with that of chickens given only the aflatoxin-contaminated diet. 5. CaMont did not cause adverse effects in chickens that did not receive aflatoxins. 6. CaMont at pH 8.5 partially reduced the toxic effects of aflatoxins in broilers when included at levels of 2.5 and 5 g/kg in the diet.

Studies in the literature data have shown that the prevalence of obstructive sleep apnea (OSA) in children with epilepsy is high and that treatment for OSA leads to a reduction in the number of seizures; by contrast, few studies have demonstrated an increased prevalence of interictal epileptiform discharges (IEDs) or epilepsy in children with sleep-disordered breathing (SDB). The aim of the present study was to confirm the high prevalence of IEDs or epilepsy in a large sample of children with SDB and to collect follow-up data. Children were recruited prospectively and underwent their first video-polysomnography (video-PSG) for SDB in a teaching hospital sleep center. Of the 298 children who fulfilled the diagnostic criteria for sleep-disordered breathing, 48 (16.1%) children were found to have IEDs, three of these 48 children were also found to have nocturnal seizures (two females diagnosed with rolandic epilepsy and a male diagnosed with frontal lobe epilepsy). Only 11 subjects underwent a second video-PSG after 6months; at the second video-PSG, the IEDs had disappeared in six subjects, who also displayed a reduced AHI and an increased mean overnight saturation. Thirty-eight of the 250 children without IEDs underwent a second video-PSG after 6months. Of these 250 children, four, who did not display any improvement in the respiratory parameters and were found to experience numerous stereotyped movements during sleep, were diagnosed with nocturnal frontal lobe epilepsy. Our study confirms the high prevalence of IEDs in children with SDB. Follow-up data indicate that they may recede over time, accompanied by an improvement of sleep respiratory parameters., (© 2013.)

Overnight polysomnography (PSG) is an expensive procedure which can only be used in a minority of cases, although it remains the gold standard for the diagnosis of sleep disordered breathing (SDB). The objective of this study was to develop a simple, PSG-validated tool to screen SDB, thus reducing the use of PSG. For every participant we performed PSG and a sleep clinical record was completed. The sleep clinical record consists of three items: physical examination, subjective symptoms and clinical history. The clinical history analyses behavioural and cognitive problems. All three items were used to create a sleep clinical score (SCS). We studied 279 children, mean ± SD age 6.1 ± 3.1 years, 63.8% male; 27.2% with primary snoring and 72.8% with obstructive sleep apnoea (OSA) syndrome. The SCS was higher in the OSA syndrome group compared to the primary snoring group (8.1 ± 9.6 versus 0.4 ± 0.3, p<0.005), correlated with apnoea/hypopnoea index (p=0.001) and had a sensitivity of 96.05%. Positive and negative likelihood ratios were 2.91 and 0.06, respectively. SCS may effectively be used to screen patients as candidates for PSG study for suspected OSA syndrome, and to enable those with a mild form of SDB to receive early treatment.

Background: Astronauts are required to perform both resistance and aerobic exercise while in orbit. This study assessed the aerobic energy yield and related physiological measurements using a nongravity dependent flywheel device designed for both resistance and aerobic exercise (RAD) in space., Methods: Eight physically active men and women performed all-out rowing on the RAD. For comparison, exercise was also carried out employing a commercially available rowing ergometer (C2)., Results: Peak oxygen uptake during exercise using RAD and C2 averaged 3.11 +/- 0.49 and 3.18 +/- 0.50 L x min(-1), respectively. Similarly, peak plasma lactate concentration (9.6 vs. 11.2 mmol x L(-1)), heart rate (183 vs. 184 bpm), and rate of perceived exertion (15.8 vs. 16.0) were comparable across exercise using the two devices., Discussion: Collectively, the results suggest that this novel exercise modality offers cardiovascular and metabolic responses, and thus aerobic exercise stimulus that is equally effective as that evoked by established technology for indoor rowing. Given the need for physiologically sound and highly effective exercise countermeasures that features small mass and envelope, and allows for resistance and aerobic exercise in a single apparatus, we believe this novel hardware should be considered for use in space.

We show that bimetallic surface alloying provides a viable route for governing the interaction between graphene and metal through the selective choice of the elemental composition of the surface alloy. This concept is illustrated by an experimental and theoretical characterization of the properties of graphene on a model PtRu surface alloy on Ru(0001), with a concentration of Pt atoms in the first layer between 0 and 50%. The progressive increase of the Pt content determines the gradual detachment of graphene from the substrate, which results from the modification of the carbon orbital hybridization promoted by Pt. Alloying is also found to affect the morphology of graphene, which is strongly corrugated on bare Ru, but becomes flat at a Pt coverage of 50%. The method here proposed can be readily extended to several supports, thus opening the way to the conformal growth of graphene on metals and to a full tunability of the graphene-substrate interaction.

The Earth acts as a gigantic heat engine driven by the decay of radiogenic isotopes and slow cooling, which gives rise to plate tectonics, volcanoes and mountain building. Another key product is the geomagnetic field, generated in the liquid iron core by a dynamo running on heat released by cooling and freezing (as the solid inner core grows), and on chemical convection (due to light elements expelled from the liquid on freezing). The power supplied to the geodynamo, measured by the heat flux across the core-mantle boundary (CMB), places constraints on Earth's evolution. Estimates of CMB heat flux depend on properties of iron mixtures under the extreme pressure and temperature conditions in the core, most critically on the thermal and electrical conductivities. These quantities remain poorly known because of inherent experimental and theoretical difficulties. Here we use density functional theory to compute these conductivities in liquid iron mixtures at core conditions from first principles--unlike previous estimates, which relied on extrapolations. The mixtures of iron, oxygen, sulphur and silicon are taken from earlier work and fit the seismologically determined core density and inner-core boundary density jump. We find both conductivities to be two to three times higher than estimates in current use. The changes are so large that core thermal histories and power requirements need to be reassessed. New estimates indicate that the adiabatic heat flux is 15 to 16 terawatts at the CMB, higher than present estimates of CMB heat flux based on mantle convection; the top of the core must be thermally stratified and any convection in the upper core must be driven by chemical convection against the adverse thermal buoyancy or lateral variations in CMB heat flow. Power for the geodynamo is greatly restricted, and future models of mantle evolution will need to incorporate a high CMB heat flux and explain the recent formation of the inner core.

NTPDase (EC 3.6.1.5) occurs in lymphocytes and plays an important role in immune function, in that hydrolyzes extracellular nucleoside tri- and/or diphosphates to form AMP. Pythium insidiosum causes the disease pythiosis, a pyogranulomatous disease of horses, dogs, cattle, cats and humans. Most antifungal drugs are ineffective against this pathogen, and immunotherapy, a treatment approach that relies on the injection of P. insidiosum antigen, has been successfully used in humans and horses to manage this disease. In this study, we investigated NTPDase activity in lymphocytes from rabbits inoculated with zoospores of P. insidiosum. After immunotherapy, we investigated the relationship between enzymatic activity and the pattern of the immune response. One milliliter of zoospores was inoculated subcutaneously into the coastal region of each rabbit. An average of 17,500 viable mobile zoospores/mL of induction medium was administered. Inoculated rabbits were checked weekly, and the subcutaneous nodular area (cm²) was measured 28 days after inoculation. Rabbits that developed lesions received four doses of immunotherapy at intervals of 14 days. Blood samples were collected by heart puncture twice a month for the determination of NTPDase activity. The results demonstrated that NTPDase activity in lymphocytes was increased in relation to ATP hydrolysis (by about 100%) in pythiosis and returned to normal values after immunotherapy. The data demonstrating NTPDase activity before and after immunotherapy reinforce the previously elaborated hypothesis that the change from a Th2 to a Th1 immune response is responsible for the curative properties of immunotherapy., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

Changes in muscle activation and performance were studied in healthy men in response to 5 weeks of resistance training with or without "eccentric overload". Subjects, assigned to either weight stack (grp WS; n = 8) or iso-inertial "eccentric overload" flywheel (grp FW; n = 9) knee extensor resistance training, completed 12 sessions of four sets of seven concentric-eccentric actions. Pre- and post-measurements comprised maximal voluntary contraction (MVC), rate of force development (RFD) and training mode-specific force. Root mean square electromyographic (EMG(RMS)) activity of mm. vastus lateralis and medialis was assessed during MVC and used to normalize EMG(RMS) for training mode-specific concentric (EMG(CON)) and eccentric (EMG(ECC)) actions at 90°, 120° and 150° knee joint angles. Grp FW showed greater (p < 0.05) overall normalized angle-specific EMG(ECC) of vastii muscles compared with grp WS. Grp FW showed near maximal normalized EMG(CON) both pre- and post-training. EMG(CON) for Grp WS was near maximal only post-training. While RFD was unchanged following training (p > 0.05), MVC and training-specific strength increased (p < 0.05) in both groups. We believe the higher EMG(ECC) activity noted with FW exercise compared to standard weight lifting could be attributed to its unique iso-inertial loading features. Hence, the resulting greater mechanical stress may explain the robust muscle hypertrophy reported earlier in response to flywheel resistance training.

By combining high-resolution photoelectron spectroscopy and ab initio calculations, we show that carbon nanoislands formed during the growth of a long-range ordered graphene layer on Ir(111) assume a peculiar domelike shape. The understanding of the unusual growth mechanism of these C clusters, which represent an intermediate phase between the strongly coupled carbidic carbon and a quasi-free-standing graphene layer, can provide information for a rational design of graphenelike systems at the nanoscale.

Lifting velocity may have a great impact on strength training-induced adaptations. The purpose of this study was to validate a method including a metronome and a measurement tape as inexpensive tools for the estimation of mean lifting velocity during the bench press exercise. Fifteen subjects participated in this study. After determining their one repetition maximum (1RM) load, we estimated the maximum metronome rhythm (R) that each subject could maintain in the concentric phase for loads of 40 and 60% of 1RM. To estimate R, the 3 repetitions with highest concentric power, as measured by means of a linear encoder, were selected, and their average duration was calculated and converted to lifting rhythm in beats per minute (bpm) for each subject. The range of motion was measured using a regular tape and kept constant during all exercises. Subjects were instructed to begin with the barbell at arm lengths and lower it in correspondence with the metronome beep. They subsequently performed 5 repetitions at 3 different rhythms relative to R (50, 70, and 90% R) for each training load (40 and 60% of 1RM). A linear encoder was attached to the bar and used as a criterion to measure the vertical displacement over time. For each rhythm, the mean velocity was calculated with the metronome (time) and the reference distance and compared with that recorded by the linear encoder. The SEM for velocity between both testing methods ranged from 0.02 to 0.05 m.s (coefficient of variation, 4.0-6.4%; Pearson's correlation, 0.8-0.95). The present results showed that the use of a metronome and a measurement tape may be a valid method to estimate the mean velocity of execution during the bench press exercise. This simple method could help coaches and athletes achieve their strength training goals, which are partly determined by lifting velocity.

Body fluid redistribution occurs in astronauts traveling in space, potentially altering interstitial water content and hence impedance. This in turn may impact the features of electromyographic (EMG) signals measured to compare in-flight muscle function with pre- and post-flight conditions. Thus, the current study aimed at investigating the influence of similar fluid shifts on EMG spectral variables during muscle contractile activity. Ten men performed sustained isometric actions (120 s) at 20% and 60% of maximum voluntary contraction (MVC) following 1-h rest in the vertical or supine position. From single differential EMG signals, recorded from the soleus (SOL), the medial (MG) and lateral (LG) gastrocnemius muscles, initial value and rate of change over time (slope) of mean power frequency (MNF) and average rectified value (ARV) were assessed. MNF initial value showed dependence on muscle (P<0.01), but was unaffected by body tilt. MNF rate of change increased (P<0.001) with increased force and differed across muscles (P<0.05), but was not influenced (P=0.85) by altered body position. Thus, fluid shift resulting from vertical to supine tilt had no impact on myoelectrical manifestations of muscle fatigue. Furthermore, since such alteration of body fluid distribution resembles that occurring in microgravity, our findings suggest this may not be a methodological limitation, when comparing EMG fatigue indices on Earth versus in space.

The study analyzed the discharge characteristics of the motor units in an intrinsic muscle of a transplanted hand. Multichannel electromyographic (EMG) recordings were obtained in 11 experimental sessions over 16 mo starting from day 205 after a hand was transplanted in a 35-yr-old man who had lost his right hand 22 yr earlier. The action potentials discharged by single motor units were identified from the surface EMG signals of the abductor digiti minimi muscle in the transplanted hand as the individual performed 60-s maximal and linearly increasing (ramp) contractions. Discharge rate decreased from 27.1 +/- 8.4 pulses per second (pps) at the start of the maximal contractions to 17.2 +/- 2.9 pps at the end (P < 0.001) and increased from 17.4 +/- 4.3 to 22.1 +/- 5.0 pps during the ramp contractions (P < 0.05). The SD of the interspike interval (ISI) nearly related to the mean ISI with a similar regression slope for the maximal (0.49 +/- 0.09) and ramp contractions (0.43 +/- 0.10). The coefficient of variation for ISI was higher than values in able-bodied persons and did not change during either the maximal (36.8 +/- 10.8%) or the ramp contractions (35.9 +/- 7.4%). High-frequency bursts of activity with <20 ms between two and six action potentials occurred during both maximal and ramp contractions. In conclusion, motor neurons that reinnervated a muscle in a transplanted hand discharged action potentials with a high degree of variability that suggested greater synaptic noise during the voluntary contractions.

Fifteen healthy men performed a 5-week training program comprising four sets of seven unilateral, coupled concentric-eccentric knee extensions 2-3 times weekly. While eight men were assigned to training using a weight stack (WS) machine, seven men trained using a flywheel (FW) device, which inherently provides variable resistance and allows for eccentric overload. The design of these apparatuses ensured similar knee extensor muscle use and range of motion. Before and after training, maximal isometric force (MVC) was measured in tasks non-specific to the training modes. Volume of all individual quadriceps muscles was determined by magnetic resonance imaging. Performance across the 12 exercise sessions was measured using the inherent features of the devices. Whereas MVC increased (P < 0.05) at all angles measured in FW, such a change was less consistent in WS. There was a marked increase (P < 0.05) in task-specific performance (i.e., load lifted) in WS. Average work showed a non-significant 8.7% increase in FW. Quadriceps muscle volume increased (P < 0.025) in both groups after training. Although the more than twofold greater hypertrophy evident in FW (6.2%) was not statistically greater than that shown in WS (3.0%), all four individual quadriceps muscles of FW showed increased (P < 0.025) volume whereas in WS only m. rectus femoris was increased (P < 0.025). Collectively the results of this study suggest more robust muscular adaptations following flywheel than weight stack resistance exercise supporting the idea that eccentric overload offers a potent stimuli essential to optimize the benefits of resistance exercise.

The dissociation and formation of water on the Rh(111) and Ni(111) surfaces have been studied using density functional theory with generalized gradient approximation and ultrasoft pseudopotentials. Calculations have been performed on 2x2 surface unit cells, corresponding to coverages of 0.25 ML, with spot checks on 3x3 surface unit cells (0.11 ML). On both surfaces, the authors find that water adsorbs flat on top of a surface atom, with binding energies of 0.35 and 0.25 eV, respectively, on Rh(111) and Ni(111), and is free to rotate in the surface plane. Barriers of 0.92 and 0.89 eV have to be overcome to dissociate the molecule into OH and H on the Rh(111) and Ni(111) surfaces, respectively. Further barriers of 1.03 and 0.97 eV need to be overcome to dissociate OH into O and H. The barriers for the formation of the OH molecule from isolated adsorbed O and H are found to be 1.1 and 1.3 eV, and the barriers for the formation of the water molecule from isolated adsorbed OH and H are 0.82 and 1.05 eV on the two surfaces. These barriers are found to vary very little as coverage is changed from 0.25 to 0.11 ML. The authors have also studied the dissociation of OH in the presence of coadsorbed H or O. The presence of a coadsorbed H atom only weakly affects the energy barriers, but the effect of O is significant, changing the dissociation barrier from 1.03 to 1.37 and 1.15 eV at 0.25 or 0.11 ML coverage on the Rh(111) surface. Finally, the authors have studied the dissociation of water in the presence of one O atom on Rh(111), at 0.11 ML coverage, and the authors find a barrier of 0.56 eV to dissociate the molecule into OH+OH.

A gravity-independent flywheel exercise device (FWED) has been proven effective as a countermeasure to loss of strength and muscle atrophy induced by simulated microgravity. This study assessed muscle-fiber conduction velocity (CV) and surface EMG instantaneous mean power spectral frequency (iMNF) during brief bouts of fatiguing concentric (CON) and eccentric (ECC) exercise on a FWED in order to identify electromyographic (EMG) variables that can be used to provide objective indications of muscle status when exercising with a FWED. Multichannel surface EMG signals were recorded from vastus lateralis and medialis muscles of nine men during: (1) isometric, 60-s action at 50% of maximum voluntary action (MVC); (2) two isometric, linearly increasing force ramps (0-100% MVC); and (3) dynamic CON/ECC coupled actions on the FWED. Muscle-fiber CV and iMNF were computed over time during the three tasks. During ramps, CV, but not iMNF, increased with force (P < 0.001). Conduction velocity and iMNF decreased with the same normalized rate of change in constant-force actions. During CON/ECC actions, the normalized rate of change over time was larger for CV than iMNF (P < 0.05). These results suggest that, during fatiguing, dynamic, variable-force tasks, changes in CV cannot be indirectly inferred by EMG spectral analysis. This underlines the importance of measuring both CV and spectral variables for muscle assessment in dynamic tasks.

Intramuscular and surface electromyographic (EMG) activities were recorded from the left and right upper trapezius muscle of eight healthy male subjects during 5-min long static contractions at 2% and 5% of the maximal voluntary contraction (MVC) force. Intramuscular signals were detected by wire electrodes while surface EMG signals were recorded with linear adhesive electrode arrays. The surface EMG signals were averaged using the potentials extracted from the intramuscular EMG decomposition as triggers. The conduction velocity of single motor units (MUs) was estimated over time from the averaged surface potentials while average rectified value and mean power spectral frequency were computed over time from 0.5 s epochs of surface EMG signal. It was found that (1) MUs were progressively recruited after the beginning of sustained contractions of the upper trapezius muscle at 2% and 5% MVC, (2) the conduction velocity of the MUs active since the beginning of the contraction significantly decreased over time, and (3) although the CV of single MUs significantly decreased, the mean power spectral frequency of the surface EMG did not show a consistent trend over time. It was concluded that spectral surface EMG analysis, being affected by many physiological mechanisms, may show limitations for the objective assessment of localized muscle fatigue during low force, sustained contractions. On the contrary, single motor unit conduction velocity may provide an early indication of changes in muscle fiber membrane properties with sustained activity.

The aim of the study was to investigate the relationship between a fatigue-induced increase of perceived exertion in the neck with a decrease of mean power frequency (MPF) in the surface electromyography (sEMG) signal during repeated shoulder elevation endurance tasks. About Thirty-two healthy women (age range 20-62) performed two maximum 6-min shoulder elevation endurance tasks at 30% of their maximal voluntary contraction (MVC) level, separated by a rest of 6 min. During these exercises, perceived exertion was estimated using the Borg scale (range 0-10), whereas the MPF of the sEMG signal from the upper trapezius was simultaneously detected. Linear regression analysis was applied over time for each trial and subject for both MPF and Borg scale rating values. The MPF was normalized by the intercept of the linear regression analysis. The resulting slopes of normalized mean power frequency (nMPF) and Borg scale rating were correlated with each other by linear regression for both trials. In order to investigate the individual behavior of fatigue effects between trials, Delta (trial 2-trial 1) slopes of nMPF and Borg scale ratings were calculated for each subject. These slopes of nMPF and Borg scale ratings were correlated with each other as well by linear regression. The increase of Borg scale ratings, as well as the decrease of nMPF, were significantly higher in trial 2 than trial 1 (P<0.01). The results show a linear correlation between slopes of nMPF and Borg scale ratings for both trials 1 and 2 (r=0.76, P<0.01). Trial-to-trial slopes (Delta (trial 2-trial 1)) of nMPF and Borg scale rating, were also significantly correlated (r=0.68, P<0.05). Thus, the individually sensed increase of perceived exertion in the neck during trial 2 was accompanied by a simultaneously higher detected decrease of nMPF. These findings indicate a close relationship between subjective perception of exertion in the neck and objectively assessed muscle fatigue of the upper trapezius.

Time-frequency analysis of the surface electromyographic (EMG) signal is used to assess muscle fiber membrane properties during dynamic contractions. The aim of this study was to compare the direct estimation of average muscle fiber conduction velocity (CV) with instantaneous mean frequency (iMNF) of surface EMG signals in isometric and explosive dynamic contractions. The muscles investigated were the vastus lateralis and medialis of both thighs in 12 male subjects. The isometric contractions were at linearly increasing force (0-100% of the maximal voluntary contraction in 10s). The explosive contractions were performed on a multipurpose ergometer-dynamometer (MED). The subject, sitting on the MED, performed six explosive contractions, separated by 2 min rest, by pushing against two force platforms and thrusting himself backwards with the maximum possible speed, while completely extending his legs. The estimated CV significantly increased with force in both the isometric (mean+/-S.D., from 3.24+/-0.34 to 5.12+/-0.31 m/s for vastus lateralis and from 3.17+/-0.26 to 5.11+/-0.34 m/s for vastus medialis, with force in the range 10-100% of the maximal voluntary contraction level) and explosive contractions (from 4.36+/-0.49 to 5.00+/-0.47 m/s for vastus lateralis, and from 4.32+/-0.46 to 4.94+/-0.44 m/s for vastus medialis, with force in the range 17.5-100% of maximal thrusting force). Moreover, estimated CV was not significantly different at the maximal force in the two exercises. On the contrary, iMNF, computed from the Choi-Williams time-frequency transform, was significantly lower in the explosive (57.7+/-8.2 and 66.5+/-10.3 Hz for vastus laterialis and medialis, respectively) than in the isometric exercises (73.7+/-9.2 and 75.0+/-8.5 Hz for vastus laterialis and medialis, respectively) and did not change with force in any of the conditions. It was concluded that EMG spectral features provide different information with respect to average muscle fiber CV in dynamic contractions. Thus, in general, they cannot be used to infer CV changes during the exertion of a dynamic task. A joint analysis of CV and EMG spectral features is necessary in this type of contractions.

Functional recovery of transplanted hand can be evaluated clinically but until now there has been no direct assessment of muscle control. In October 2000 we transplanted the right hand of a brain-dead man aged 43 onto a man aged 35 who had lost his right dominant hand 22 years before. Starting from day 205 after the transplant, multi-channel surface electromyographic (EMG) signals were recorded from intrinsic muscles of the transplanted hand in order to assess their degree of reinnervation. Eleven months post-operatively, the first motor unit action potential train was detected from the abductor digiti minimi. One month later, also the abductor pollicis brevis and the opponens pollicis muscles showed motor unit activity, while, after 15 and 24 months, the first dorsal interosseous and the first lumbricalis muscles, respectively, showed activation of their first motor units. An increase in the number of active motor units was observed after the first signs of reinnervation, although the process was rather slow. In sustained maximal contractions, the motor unit discharge rate decreased from (mean +/- S.D.) 34.0+/-6.7 pps to 23.4+/-5.1 pps in 60 s for the abductor digiti minimi, although the subject was verbally encouraged to maintain a maximal activation. Moreover, the subject was able to perform basic control tasks involving voluntary modulation of motor unit discharge rate. With a visual feedback, he could increase discharge rate of the abductor digiti minimi approximately linearly over time, from 13.4+/-6.7 pps to 32.5+/-11.2 pps in 60 s. In conclusion, we showed reinnervation of single motor units in a transplanted hand after 22 years of denervation. Moreover, voluntary modulation of discharge rates of these motor units could be performed since the first sign of reinnervation.

Neuromuscular problems reduce working ability of aging workers, and increase cases of work loss and accidents. For this reason, elderly people throughout Europe are forced into early retirement, and fail to be self-supporting. There is a need to identify and monitor work related neuromuscular disorders in order to reduce their consequences by monitoring the most vulnerable individuals, identify the determinants of neuromuscular aging related to occupational conditions, prevent pathologies and their evolution. Preliminary results show the possibility of identification of neuromuscular problems through non invasive techniques, some of which, recently developed within the SENIAM and PROCID Concerted Actions, can provide quantitative indices of neuromuscular performance. Substantial field tests and training initiatives are required to demonstrate if these techniques can be used outside the research labs, if there may be a European market in the fields of ergonomics and occupational health, and if they can be routinely used with standardized methodology to monitor the relationship between occupational and neuromuscular system conditions in the working environment. The objective of the European Project Neuromuscular assessment in the Elderly Worker (NEW) is to answer these questions.

The aim of this study was to interpret changes in experimentally recorded M waves with progressive motor unit (MU) activation based on simulation of the surface electromyogram. Activation order during transcutaneous electrical stimulation was analyzed by investigating M-wave average rectified value, spectral properties, and conduction velocity (CV) during electrically elicited contractions. M-waves were detected from the biceps brachii muscle of 10 healthy male subjects by a linear adhesive array of eight electrodes. Electrical stimulation was delivered to the motor point at either constant current intensity (40, 60, 80, and 100% of the supramaximal stimulation current) or with linearly increasing current. A model of surface electromyogram generation that varied activation order based on MU size and location was used to interpret the experimental results. From the experimental and model analysis, it was found that 1) MUs tended to be activated from low to high CV and from the superficial to the deep muscle layers with increasing transcutaneous electrical stimulation of the biceps brachii muscle, and 2) characteristic spectral frequencies of the M-wave were affected by many factors other than average CV (such as the activation order by MU location or the spread of the MU innervation zones and CVs), thus decreasing with a concomitant increase in CV during progressive MU activation.

The use of mono- and bi-dimensional electromyogram (EMG) electrode arrays for the assessment of the neuromuscular system can provide an insight into muscle physiology not achieved with classical bipolar surface EMG. Among the advantages of multichannel EMG detection, there is a) the possibility of estimating muscle fibre conduction velocity, even during motor tasks, and b) the possibility to increase the number of detection points on a muscle, improving the performance of pattern-based EMG decomposition methods. For these reasons, the development and use of multichannel surface EMG devices and techniques were chosen as the primary goals within the European RTD Project 'Neuromuscular assessment in the elderly worker' (NEW). The specific requirements of Project NEW called for the availability of a user-friendly, small-sized EMG acquisition system for field use, suitable for multichannel EMG recording using electrode arrays from one or more muscles. A market survey established that none of the commercially available EMG acquisition systems featured all the desired specifications, nor could they be easily adapted for specific use. The paper describes the design of an innovative acquisition system for long-term multichannel EMG recording fulfilling these requirements and comprising adhesive electrode arrays for artifact-free EMG acquisition during work activity and a portable, user-friendly, battery-powered acquisition system for multichannel EMG recording and storage on a removable PCMCIA card. The system has been used extensively within Project NEW for laboratory and field tests and can find applications in other fields of basic and applied research, including ergonomics, occupational and sports medicine.

Surface electromyographic (EMG) crosstalk between vastus lateralis, vastus medialis, and rectus femoris muscles was evaluated by selective electrical stimulation of one muscle and recording from the stimulated and another muscle with linear surface arrays of eight electrodes. The ratio between the amplitude of the signals recorded over nonstimulated and stimulated muscles and their correlation coefficient were used as indices to quantify crosstalk. Single-differential and double-differential detection systems were used with interelectrode distances in the range 10-40 mm. The multichannel EMG signals clearly showed that crosstalk is largely due to nonpropagating potentials that correspond in time to the end of the propagation of the action potentials generated by the stimulated muscle. The crosstalk signal increased with increasing interelectrode distance and was statistically higher for single- than for double-differential recordings. The correlation-based indices of crosstalk were poorly correlated with the amplitude-based indices. Moreover, the characteristic spectral frequencies of the signals detected over the nonstimulated muscles were statistically higher than those from the stimulated muscles. A mathematical model of signal generation was used to explain the experimental findings. This study clarifies many controversial findings of past investigations and creates the basis for crosstalk interpretation, simulation, and reduction., (Copyright 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 681-695, 2002)

Background: Thyroid surgery presents a low incidence of complications. Death is certainly a rare, or even exceptional event. Hypoparathyroidism, above all if definitive, is the main complication of total thyroidectomy with percentages that very between 0 and 10% in the literature (average 2%)., Methods: The incidence of recurrent lesions varies between an improbable 0% to 8%, whereas lesions to the superior laryngeal nerve are relatively frequent, but often undervalued. Dysphagia, although always transient, presents a high risk of pneumonia ab ingestis and severe dehydration. Hemorrhage has an incidence of 0.1-3.8% and infection is reported in approximately 1% of cases. The permanent and recurrence nature of thyroid pathology in literature is between 5 and 11%, resulting from inadequate or sometimes useless surgery. Hypothyroidism is the logical consequence of total thyroidectomy. In the light of these data we have re-examined 300 operations involving thyroid pathology performed by the same team using the same method over the past 4 years (82% females, 18% males). 33% of the cases presented benign euthyroid nodular pathology, 27% hyperfunctioning benign nodular pathology, 2.6% Flajani-Basedow-Graves disease, 9% were adenomas, 7% were differentiated carcinomas, 2% anaplastic carcinomas and 0.7% medullary carcinomas. 99 extracapsular total loboisthmectomies, 135 total extracapsular thyroidectomies and 66 subtotal thyroidectomies were performed., Results: The following complications were observed: 31/300 symptomatic hypocalcemias of which 25 were transient and 6 (2%) were definitive but easily controlled with treatment; 9 recurrent monoplegias out of 501 isolated recurrent forms of which 4 (0.8%) was permanent; 5/300 (1.7%) postoperative dysphagias associated with recurrent monoplegia in 4 cases. Damage to the external branch of the superior laryngeal nerve was suspected in 11/300 cases (3.7%). Postoperative hemorrhage occurred with an incidence of 1.3%, whereas the incidence of wound infection and serous collection was 1.7%. Moreover, persistent hyperthyroidism after subtotal bilateral thyroidectomy was observed secondary to toxic plurinodular struma. A case of paralysis of the right ulnar nerve, when the arm was adducted, was observed on the operating table, but regressed after about 4 months. Mortality was zero., Conclusions: Thyroid surgery is still hampered by a relatively low percentage of complications, which are probably still the result of various technical limitations, and it appears difficult to reduce these, let alone eliminate them completely.

Background: Decision making about the opportunity of starting or continuing hormone replacement therapy (HRT) in menopause should rely on an overall evaluation of its risks and benefits for the women's health; the evaluation of HRT cost-benefit ratio, however, should include its possible outcomes from an economical point of view. In this view, and with the certainty that menopausal patients should be protected by proper treatments, our case series has been evaluated in order to improve the quality of our clinical schedules for both their access to HRT and the treatment follow-up., Methods: Two groups of patients have been considered the first one consisted of 560 women observed during '97 for climacteric symptoms and candicated to begin HRT. The second one consisted of 100 women on HRT for 1 to 6 years. In the first group we considered which test and with which frequency were responsible for stopping or delay the beginning of therapy; while in the second group we evaluated the reasons for stopping treatment., Results and Conclusions: On the basis of our experience, the exams required before starting HRT seem to be the following: patient history, mammography, densitometry and endometrial sample as well as the parameters of glucose lipidic, coagulative and hepatic metabolism. Densitometry is useful in the annual follow-up only in patients with bone alterations from the beginning. The same exams seem required for the follow-up, with the exception of bone densitometry which should be performed yearly only in patients with bone demineralization.

The authors present a series of 70 bilateral inguinal hernias selected from a total of 641 inguinal hernias operated from May 1994 to November 1996 using alloplastic surgery. They discuss the most appropriate methods of access for treating this pathology in a single operation, and propose inguinal access as the most preferable method owing to its easy execution and apparently greater safety. Laparoscopic techniques should be reserved for special cases such as pluri-recidivating hernias.

Ileal carcinoma is not frequent and its diagnosis is preoperatively quite difficult. The surgical approach often depends more on the on table situation than on a precise therapeutic protocol. The histological result is sometimes a real negative surprise and the five year survival of patients is similar to those operated for colonic carcinoma at the same stage.

A case of a symptomatic colonic lipoma causing recurrent abdominal pain and intestinal obstruction, not treated is reported. Lipomas are the most common mesenchymal benign tumors that can be found in the colon and are second as frequence only to the adenomatous polyps. In 65% of cases the lipomas are located in the large bowel and represent the most common cause of intestinal intussusception in the adult. Lipomas are most frequent in the right colon (40%-68%) an opposite distribution in comparison with adenocarcinomas and adenomatous polyps. When their diameter is more than 3 cm, lipomas become symtomatic. In lipomas less then 2 cm in diameter it is possible an endoscopic removal while for bigger sizes the surgical laparoscopic approach is recommended.

Intestinal injuries are pathologies frequently caused by toothpicks. In literature are reported serious damage to the cardiovascular system, lung and systemic fatal sepsis. In literature are also reported some deaths caused by delayed diagnosis. The authors report two cases of intestinal perforation by toothpick. Both patients had accidentally swallowed the toothpick. The clinical state was compatible with acute abdomen in a 59 year old psychopathic patient and acute appendicitis in a 27 year old patient. The aim of this paper is to emphasize the importance of a careful anamnesis for detecting the swallowing of a toothpick.

Sigmoid colon is the most frequent side for a volvulus. We present four cases of sigmoid volvulus admitted to our department during the period July 1994-December 1995. Intestinal volvulus, despite its benignity, has a quite high morbidity and mortality. Important factors such as the patient's features and frequent late diagnosis can influence the complicated outcome of the disease. Plane X-ray of the abdomen is helpful while barium enema can be therapeutical because of the pressure of the inflated air. Sigmoid resection is the most effective treatment for the disease.

We studied 18 early (6 to 36 months) postmenopausal patients with a mean age of 51 years (47-53), who had never undergone hormone replacement therapy before and had no contraindications to hormone replacement. All cases of menopause were spontaneous. The treatment consisted in the continuous transdermal administration of 17-beta-estradiol (50 microg/daily) by skin patch to be replaced every 84 hours. The patients were further treated with a two-week progestogen administration every fortnight. This consisted of transdermal norethisterone acetate (0.25 mg/daily) combined with estradiol in the same patch in the first year, and oral dihydrogesterone (10 mg/daily) in the second year, without wash-out period. Before treatment (T0), and at the 12th (T1) and 24th (T2) month we measured the body mass index, the arterial blood pressure (AP), lipoproteins, coagulation parameters and bone metabolism parameters. The systolic pressure presented mean values (+/-SD) equal to 128.5+/-10.2 mmHg (T0), 131.1+/-7.4 mmHg (T1) and 130.4+/-7.5 mmHg (T2). Diastolic pressure values showed mean value ranging from 85.4+/-8.7 mmHg (T0) to 83.9+/-5.3 (T1) and 83.4+/-5.8 mmHg (T2). The detailed analysis of values of triglycerides, HDL cholesterol, apolipoprotein A1, apolipoprotein B and coagulation parameters at different times of therapy showed no statistically significant changes. With regard to bone metabolism, no statistically significant changes from baseline values were observed in parathormone, alkaline phosphatase, calcitonin, urinary calcium/creatinine ratio, and bone mineral content expressed by the bone density.

In this study we evaluated different metabolic parameters and bone mass, before and after 18 months of treatment by transdermal estradiol associated with oral sequential MPA in menopause. We treated 46 physiologically postmenopausal patients (44-55 years old) for at least six months, by TTS/E2 50 mcg for 3 weeks and MPA 10 mg for the last 12 days of estradiol treatment. The fourth week was free of therapy. Before treatment and after 18 months, we evaluated bone density (BMC/BW), body mass index (W/sqH), systolic and diastolic blood tension, lipid parameters, coagulation parameters, mineral metabolism with statistical elaboration of our results. After therapy we found a significant decrease in diastolic blood tension, a significant reduction in triglyceride levels and a slight but significant increase in HDL-cholesterol levels. The only variation in coagulation parameters was a decrease of circulating fibrinogen. No variation occurred in the body mass index, mineral metabolism or bone density. In conclusion even long term transdermal treatment seems metabolically well tolerated and very useful in relieving neurovegetative climacteric symptoms and dystrophic genital ones.

The Monoclonal Antibody technology has been used in 29 cases of ovarian cancer. The immuno-enzyme-assay detected positive levels of estrogen cytoplasmatic receptor in 51.8% of the cases as well as in the nuclear (51.8%). Moreover, the ER/EIA technique screened positive levels of Total ER (ER/t) in 72.4% versus 65.5% obtained by DCC-method. 24.1% of the cases had negative ER/t levels observed by EIA. The monoclonal antibody anti-ER is a very interesting method for studying hormone-dependent tissue, because it uses an immunological binding to antigenic protein (receptor).