Progressive Velocity Research Articles

Differential Expression of Genes Involved in the Degeneration and Regeneration Pathways in Mouse Models for Muscular Dystrophies

The genetically determined muscular dystrophies are caused by mutations in genes coding for muscle proteins. Differences in the phenotypes are mainly the age of onset and velocity of progression. Muscle weakness is the consequence of myofiber degeneration due to an imbalance between successive cycles of degeneration/regeneration. While muscle fibers are lost, a replacement of the degraded muscle fibers by adipose and connective tissues occurs. Major investigation points are to elicit the involved pathophysiological mechanisms to elucidate how each mutation can lead to a specific degenerative process and how the regeneration is stimulated in each case. To answer these questions, we used four mouse models with different mutations causing muscular dystrophies, Dmd (mdx), SJL/J, Large (myd) and Lama2 (dy2J) /J, and compared the histological changes of regeneration and fibrosis to the expression of genes involved in those processes. For regeneration, the MyoD, Myf5 and myogenin genes related to the proliferation and differentiation of satellite cells were studied, while for degeneration, the TGF-β1 and Pro-collagen 1α2 genes, involved in the fibrotic cascade, were analyzed. The result suggests that TGF-β1 gene is activated in the dystrophic process in all the stages of degeneration, while the activation of the expression of the pro-collagen gene possibly occurs in mildest stages of this process. We also observed that each pathophysiological mechanism acted differently in the activation of regeneration, with distinctions in the induction of proliferation of satellite cells, but with no alterations in stimulation to differentiation. Dysfunction of satellite cells can, therefore, be an important additional mechanism of pathogenesis in the dystrophic muscle.

Protective effects of tripterygium glycoside-loaded solid lipid nanoparticles on male reproductive toxicity in rats

The protective effects of tripterygium glycoside-loaded solid lipid nanoparticles (TG-SLNs) on male reproductive toxicity were investigated in rats. Thirty-six male Sprague-Dawley rats were randomly divided into three groups of 12: control group, tripterygium glycoside (TG) group, and TG-SLN group. After the animals had been orally administered with the substances for 28 consecutive days, their sperm count and sperm motility, organ coefficients, serum testosterone levels, testicular ultrastructure, and reproductive ability were observed. The results showed that the sperm motility rate in the TG group was only 3%, whereas the rates in the TG-SLN and control groups were 33% and 71%, respectively. Compared with those in the control group, the motion counts of path velocity, track speed, progressive velocity, straightness, linearity, beat cross frequency, amplitude of lateral head displacement, and sperm concentrations in the TG-SLN group were not significantly different while those in the TG group significantly decreased (p < 0.01). TG-SLNs did not cause testicular atrophy and instead maintained normal serum testosterone levels. The effect of TG-SLNs on the testicular ultrastructure was very evident; the morphologies of Sertoli, spermatogonial, mitochondrial, and sperm cells were normal. In terms of reproductive ability, one rat (17%) from the TG-SLN group and five rats (83%) from the control group became pregnant, whereas none of the rats from the TG group became pregnant. These data indicate that TG-SLNs have potentially protective effects on male reproductive toxicity in rats.

Evaluation of ram semen quality using polyacrylamide gel instead of cervical mucus in the sperm penetration test

Fertility is a very complex biological function that depends on several properties of the spermatozoa, including sperm motility. Two objectives are analyzed in this study: (1) Replace the cervical mucus by a synthetic medium in a sperm penetration test, and (2) evaluating the results of this test objectively analyzing the sperm number that migrates. In experiment 1, we have tested eight concentrations of acrylamide (1%–2%). Rheological properties of media were analyzed. The plastic straws, loaded with acrylamide, were placed vertically on the semen sample tube for 15 min at 39 °C. After, the acrylamides were placed, by segments of 5 mm, into wells of a 24-well plate, dyed with Hoechst 33342 and the number of spermatozoa were calculated by automated microscopy analysis. The 1.55% and 1.6% acrylamide gel showed a number of spermatozoa emigrating closer to that seen with natural mucus. In experiment 2, we applied the sperm penetration in acrylamide 1.6% and 1.55% using fresh semen and cooled semen at 15 °C and 5 °C. The spermatozoa counts were performed for each segment of 10 mm. Semen chilled at 15 °C presented intermediate values of sperm counts in comparison with fresh semen (higher) and 5 °C chilled semen. The sperm counts do not differ between acrylamides but the rheological properties of acrylamide 1.6% were more similar to those of the natural cervical mucus. In experiment 3, we have observed significant correlations between the number of spermatozoa and several sperm quality parameters (positive: progressive motility and velocity according to the straight path; negative: damaged acrosomes and apoptotic cells) in 1.6% acrylamide media. We conclude that the size of the cell subpopulation, objectively calculated, that migrate beyond 20 mm in 0.5-mL straws filled with acrylamide is a useful parameter in ram sperm quality assessment and further studies are needed to evaluate its relationship with field fertility.

Peripheral and Central Inputs Shape Network Dynamics in the Developing Visual Cortex In Vivo

Spontaneous network activity constitutes a central theme during the development of neuronal circuitry [1, 2]. Before the onset of vision, retinal neurons generate waves of spontaneous activity that are relayed along the ascending visual pathway [3, 4] and shape activity patterns in these regions [5, 6]. The spatiotemporal nature of retinal waves is required to establish precise functional maps in higher visual areas, and their disruption results in enlarged axonal projection areas (e.g., [7-10]). However, how retinal inputs shape network dynamics in the visual cortex on the cellular level is unknown. Using in vivo two-photon calcium imaging, we identified two independently occurring patterns of network activity in the mouse primary visual cortex (V1) before and at the onset of vision. Acute manipulations of spontaneous retinal activity revealed that one type of network activity largely originated in the retina and was characterized by low synchronicity (L-) events. In addition, we identified a type of high synchronicity (H-) events that required gap junction signaling but were independent of retinal input. Moreover, the patterns differed in wave progression and developmental profile. Our data suggest that different activity patterns have complementary functions during the formation of synaptic circuits in the developing visual cortex.

Self-reported gait unsteadiness in mildly impaired neurological patients: an objective assessment through statistical gait analysis

BackgroundSelf-reported gait unsteadiness is often a problem in neurological patients without any clinical evidence of ataxia, because it leads to reduced activity and limitations in function. However, in the literature there are only a few papers that address this disorder. The aim of this study is to identify objectively subclinical abnormal gait strategies in these patients.MethodsEleven patients affected by self-reported unsteadiness during gait (4 TBI and 7 MS) and ten healthy subjects underwent gait analysis while walking back and forth on a 15-m long corridor. Time-distance parameters, ankle sagittal motion, and muscular activity during gait were acquired by a wearable gait analysis system (Step32, DemItalia, Italy) on a high number of successive strides in the same walk and statistically processed. Both self-selected gait speed and high speed were tested under relatively unconstrained conditions. Non-parametric statistical analysis (Mann–Whitney, Wilcoxon tests) was carried out on the means of the data of the two examined groups.ResultsThe main findings, with data adjusted for velocity of progression, show that increased double support and reduced velocity of progression are the main parameters to discriminate patients with self-reported unsteadiness from healthy controls. Muscular intervals of activation showed a significant increase in the activity duration of the Rectus Femoris and Tibialis Anterior in patients with respect to the control group at high speed.ConclusionsPatients with a subjective sensation of instability, not clinically documented, walk with altered strategies, especially at high gait speed. This is thought to depend on the mechanisms of postural control and coordination. The gait anomalies detected might explain the symptoms reported by the patients and allow for a more focused treatment design. The wearable gait analysis system used for long distance statistical walking assessment was able to detect subtle differences in functional performance monitoring, otherwise not detectable by common clinical examinations.

Computer assisted semen analysis for quantification of motion characteristics of bull sperm during cryopreservation cycle

Aim: The study was undertaken to quantify and to analyze the changes in the motion characteristics of bull spermatozoa during various stages of cryopreservation cycle. Materials and Methods: Using computer assisted semen analysis (CASA) technique, 26 ejaculates, collected from two Jersey bulls were analyzed for motility, head behaviour and swimming pattern of spermatozoa on dilution, pre-freeze and post-thaw stages of cryopreservation. French straw technique was employed for deep-freezing of semen using liquid nitrogen. O Results: Equilibration of diluted semen at 5 C has significantly (P< 0.01) reduced sperm motility, progressive motility, path velocity, and progressive velocity. Beat cross frequency was also affected significantly (P<0.05) by equilibration. Freezing and thawing processes drastically affected all the motility, velocity and head behaviour characteristics (P< 0.01). Conclusion: CASA facilitate objective evaluation sperm motion characteristics. Adoption of CASA technique has the potential for improvements in evaluation of semen thereby the quality of frozen semen for fertility can be enhanced. Artificial insemination (AI) in bovines is a classical assessment of quality of motility in terms of velocity, example for successful application of a biotech- swimming pattern, sperm head behaviour etc., may nological method at field level. Although fertility of help in better understanding of the possible sperm frozen-thawed semen is generally acceptable but the function. The advent of computer assisted semen analysis efficiency of cryopreservation is still relatively low. (CASA) has brought a new dimension to semen Rapid rate of cryopreservation results in cell damage evaluation. The CASA technique yields repeatable to spermatozoa due to osmotic imbalance (1). and highly reliable results on kinematics of ejaculates The mammalian spermatozoa acquire the capacity based on measurements of individual sperm cells. for flagellar movements during epididymal transport Therefore, assessment of sperm motility coupled with and it is modulated in the female reproductive tract kinetic measurements would help in better evaluation before termination during fertilization. These changes of semen quality. in flagellar activity reflect the physiological events within the sperm cell including the metabolic activity Materials and Methods and alteration of the sperm membrane (2). Further the Two Jersey bulls, aged 2 years, maintained for events of semen processing during cryopreservation instructional purpose for the students of Madras cycle bring injuries to sperm membrane leading to Veterinary College, Chennai under stall-fed conditions changes in the sperm physiology which may be were used for the study. The bulls were fed with 3 kg of reflected in sperm motility (3). Cryopreservation also concentrate/day/bull in addition to 3 kg of dry fodder affects the functional integrity of acrosome and per bull. Water and green fodder were provided ad mitochondria that is responsible for the generation of libitum. Since semen collection by artificial vagina energy from intracellular stores of ATP (4). method did not involve any intervention in the normal Conventionally, sperm motility estimation is done physiology of the animals, this experiment was by visual approximation of progressively moving exempted approval from Institutional Animal Ethics spermatozoa using phase contrast microscope. The

12 FERTILITY OF FROZEN EQUINE SPERM IN SYSTEMS FOR CRYOPRESERVATION

Optimizing cryopreservation of equine sperm will facilitate genetic banking and propagation of important horse strains through assisted reproduction. This study aimed to evaluate the motility pattern using computer-assisted sperm analysis (CASA) and plasma membrane integrity by epifluorescence microscopy of equine semen frozen in 0.5 mL straws at different freezing rates; also, a fertility trial was performed according to the freezing protocol. Three ejaculates from four stallions of various breeds (Mangalarga Marchador, Westfallen, Hanovarian and Arabian) and ages (5 to 20 years) were collected and processed for cryopreservation. The stallions were housed at the CERBEQ, Reproduction Centre of the Department of Animal Reproduction and Veterinary Radiology, UNESP. The ejaculates were filtered and submitted to analysis by CASA (HTM IVOS 12, Hamilton Thorne Research, USA). In addition, the plasma membrane integrity was determined by fluorescent probes. After evaluation, the ejaculates were diluted at 1:1 (extender:semen) with skim milk extender Botu-Semen™ and centrifuged at 600 × g for 10 min. The supernatant was removed and the pellet resuspended to a final concentration of 100 × 106 sperm mL–1 with milk-egg yolk freezing extender (Botu-Crio™). Semen was packaged in 0.5-mL straws (IMV, LAigle, France) and was placed in nitrogen for 20 min and then from room temperature to 5°C and then frozen in two different cooling systems: an isothermic box (42 cm × 28 cm × 12.5 cm) was placed upon racks suspended 6 cm above liquid nitrogen or other 20 min then immersed into nitrogen and automated system Mini Digitcool™ (IMV Technologies, France), cooling at a –40°C min–1 rate. All straws were stored in liquid nitrogen until thawing and analysis. The straws were thawed in a water bath at 46°C for 20 s and the samples were evaluated for progressive motility, angular progressive velocity, progressive velocity, track speed, percentage of rapid sperm and percentage of sperm with plasma membrane integrity. For the fertility trial, 65 clinically healthy mares had their oestrous cycle monitored by ultrasound and inseminated postovulation with sperm into the uterus. Ovulation was induced with 1 mL of deslorelin acetate (GnRH) injected IM when a 35-mm follicle was detected. Thirty-six hours later, mares were monitored every 6 h until ovulation was detected. When it was detected, mares were inseminated with 800 × 106 total sperm. Pregnancy was confirmed via ultrasound examination 15 days after ovulation. Pregnancy rate was 52.2% using the isothermic box and 60% using the automated machine. Statistical analysis from the frozen–thawed semen evaluated parameters was performed using the statistics software Proc. MIXED of SAS 9.1 and for the fertility trial, logistic regression using the Proc GENMOD from SAS 9.1. The conventional method using the isothermic box was similar to the automated machine with a fast freezing rate. Additionally, AI with 800 × 106 sperm frozen in the isothermic box or automated system resulted in similarly acceptable conception rates.

41 THE EFFECT OF AMBIENT TEMPERATURE ON SPERM MOTILITY DURING LIQUID STORAGE OF VENDA COCK SEMEN AND INDIVIDUAL DIFFERENCES IN SPERM CRYOTOLERANCE

Improving techniques for liquid storage of cock semen can increase the efficiency of AI programs in the poultry industry. The aims of the present study were (1) to compare storage of cock sperm for 24 h at 5 and 25°C and (2) to test the cryotolerance of sperm cell motility in individual Venda cocks. Semen was collected with the abdominal massage method, from 6 indigenous Venda cocks. Cocks were 26 weeks of age and were kept under the same conditions. After macroscopic analysis, semen was pooled and diluted (1:2) with Kobidil+ extender and divided into 3 equal parts. Part 1 was evaluated immediately (0 h), part 2 was stored at 5°C and part 3 was stored at 25°C and evaluated for sperm motility and velocity parameters at 4, 8, 12 and 24 h of storage. For cryopreservation, semen was diluted (1:2) with modified Kobidil+ extender supplemented with 8% of dimethyl sulfoxide. Individual ejaculates were equilibrated at 5°C for 4 h and then loaded into the programmable freezer. Then, semen straws were thawed at 5°C. Sperm motility and velocity parameters were evaluated using the Sperm Class Analyzer® system. Six replicates were done per trial. Data were analysed using the statistical programme GenStat®. Treatment means were separated using Fisher's protected t-test least significant difference (P &lt; 0.05). Total sperm cell motility rate was 87.5% and decreased significantly during in vitro storage and was &lt;31% after 24 h at 25°C. Semen samples stored at 5°C showed a total sperm cell motility rate of above 50% after 24 h. There was a slight linear decrease in the percentage of sperm with progressive motility and rapid velocity as the storage period increased, irrespective of the storage temperature. The rapid and medium motility percentages were higher in fresh semen and significantly decreased (P &lt; 0.05) during the incubation period. There was variation in the total sperm cell motility of fresh and frozen semen among cocks. There was no significant difference in variation in non-progressive and medium percentage (P &gt; 0.05) motility in diluted fresh or frozen sperm cells or in the percentage of sperm with rapid motility in thawed semen. There was variation in &lt;25% of the cocks in total sperm motility rate. In summary, cryopreservation reduced sperm cell motility and velocity rates in all the cock semen donors. We found that cryotolerance of cock sperm does vary among males. Furthermore, the lower temperature 5°C was suitable for semen storage of Venda cocks. This temperature (5°C) could potentially improve methods of semen equilibration before cryopreservation. The study was supported by an Agricultural Research Council Parliamentary Grant, Department of Agriculture Forestry and Fisheries and National Research Foundation-GUN No RT21 and 24000 (NRF). The Germplasm Conservation &amp; Reproduction Biotechnologies (GCRB) group is thanked for their support.

Application of computer-assisted semen analysis to explain variations in pig fertility1

Sperm quality is often evaluated through computer-assisted semen analysis (CASA) and is an indicator of boar fertility. The aim of this research was to study the relationship between CASA motility parameters and fertility results in pigs. Insemination records and semen parameters from a total of 45,532 ejaculates collected over a 3-yr period were used. The statistical model for analysis of fertility data from these inseminations included factors related to sow productivity. The boar- and semen-related variance (direct boar effect) were corrected for the effects of individual boar, genetic line of the boar, age of the boar, days between ejaculations, number of sperm cells in an ejaculate, number of sperm cells in an insemination dose, and AI station. The remaining variance was analyzed if semen motility parameters had a significant effect. This analysis revealed significant (P < 0.05) effects of progressive motility, velocity curvilinear, and beat cross frequency on farrowing rate (FR). Total motility, velocity average path, velocity straight line, and amplitude of lateral head displacement affected (P < 0.05) total number of piglets born (TNB). Boar- and semen-related parameters explained 5.3% of the variation in FR and 5.9% of the variation in TNB. Motility parameters, measured by CASA, explained 9% of the boar- and semen-related variation in FR and 10% of the boar- and semen-related variation in TNB. Individual boar and genetic line of the boar affected (P < 0.0001) the variation in FR and TNB. No differences (P > 0.05) were observed between effects of AI stations on fertility outcome, underscoring the objectivity of the CASA system used. Motility parameters can be measured with CASA to assess sperm motility in an objective manner. On the basis of the motility pattern, CASA enables one to discriminate between the fertilizing capacity of ejaculates, although this depends on the genetic line of the boar used in AI stations.

The Region of Largest β-Zone Parapapillary Atrophy Area Predicts the Location of Most Rapid Visual Field Progression

To determine if visual field (VF) progression occurs most rapidly in the region of largest β-zone parapapillary atrophy (PPA). Retrospective cohort. One hundred twenty-five patients from the New York Glaucoma Progression Study with both β-zone PPA and VF progression. Treated open-angle glaucoma patients with 8 or more Swedish Interactive Threshold Algorithm Standard 24-2 VFs (Humphrey Field Analyzer II; Carl Zeiss Meditec, Inc., Dublin, CA) in either eye were identified. Eyes with optic disc photographs, β-zone PPA, less than 6 diopters myopia, and VF progression were studied. Visual field progression was defined using trend analysis as the presence of at least 2 adjacent progressing points in the same hemifield using standard pointwise linear regression (PLR) criteria. The correlation between β-zone PPA and location of most rapid future VF progression. One hundred twenty-five eyes (125 patients; mean age, 71.9 ± 12.3 years; 58% women; 75% European descent) with β-zone PPA and VF progression were enrolled. The mean follow-up was 6.8 ± 1.7 years and the mean number of VFs was 12.5 ± 3.6. Ninety-three patients (74%) had more β-zone PPA inferiorly and 32 patients (26%) had more β-zone PPA superiorly. The fastest VF progression occurred in the superior hemifield in 77 patients (62%) and in the inferior hemifield in 48 (38%) patients. Patients with superior VF progression had a superior localized mean rate of progression of -1.57 ± 1.7 dB/year, and patients with inferior VF progression had an inferior localized mean rate of -0.94 ± 1.4 dB/year (P = 0.012). The mean number of points reaching the predefined PLR end points was 5.6±7.5 for the superior VF hemifield and 3.0±4.9 for the inferior hemifield (P = 0.006). The hemifield with more points reaching PLR progression end points, with fastest average velocity of progression, or both was spatially consistent with the location of largest β-zone PPA in 89 (71%) patients (P = 0.0001, Fisher exact test; κ = 0.35; 95% confidence interval, 0.17-0.53). In treated glaucoma patients with β-zone PPA and VF progression, the location of largest β-zone PPA typically correlates spatially with the region of the most rapid future VF progression. The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Telmisartan reduces neointima volume and pulse wave velocity 8 months after zotarolimus-eluting stent implantation in hypertensive type 2 diabetic patients

ObjectiveTelmisartan is a peroxisome proliferator-activated receptor-γ activator with potent anti-inflammatory and antiatherogenic effects. The authors compared the effects of telmisartan and valsartan on neointima volume, atherosclerosis progression and brachial-ankle pulse...

Combined effects of speed and directional change on postural adjustments during gait initiation

The study of gait initiation (GI) has primarily focused on gait initiated in a forward direction, however, in everyday life, GI is often combined with a directional change. Ten young adults initiated gait with their right foot in four directions (to the left: −15°, straight ahead: 0°, to the right: 15° and 30°) at self-selected and fast gait speeds. The relationship between starting direction of GI and the lateral center of foot pressure displacement for normal ( r 2 = 0.57) and fast gait speed ( r 2 = 0.75) indicated that the lateral component plays an important role with regards to controlling the desired direction of gait. At the first step of the swing limb, the progression velocity of the center of mass (CM) remained slower for the 30° condition only, whereas no difference was found between directions for CM velocity perpendicular to the intended direction. These results suggest that postural adjustments are scaled to initiate gait in a predetermined direction. By the first step, the orientation of CM is toward the intended direction of gait, however, when gait is initiated in combination with a large change in direction, additional adjustments may be required to reach the intended progression velocity.

Estimation of stride length in level walking using an inertial measurement unit attached to the foot: A validation of the zero velocity assumption during stance

In a variety of applications, inertial sensors are used to estimate spatial parameters by double integrating over time their coordinate acceleration components. In human movement applications, the drift inherent to the accelerometer signals is often reduced by exploiting the cyclical nature of gait and under the hypothesis that the velocity of the sensor is zero at some point in stance. In this study, the validity of the latter hypothesis was investigated by determining the minimum velocity of progression of selected points of the foot and shank during the stance phase of the gait cycle while walking at three different speeds on level ground. The errors affecting the accuracy of the stride length estimation resulting from assuming a zero velocity at the beginning of the integration interval were evaluated on twenty healthy subjects. Results showed that the minimum velocity of the selected points on the foot and shank increased as gait speed increased. Whereas the average minimum velocity of the foot locations was lower than 0.011 m/s, the velocity of the shank locations were up to 0.049 m/s corresponding to a percent error of the stride length equal to 3.3%. The preferable foot locations for an inertial sensor resulted to be the calcaneus and the lateral aspect of the rearfoot. In estimating the stride length, the hypothesis that the velocity of the sensor can be set to zero sometimes during stance is acceptable only if the sensor is attached to the foot.

Relationship between sperm motility, morphology and the fertility of stallions

Sperm quality has an important role in determining fertility. Although there have been numerous studies to document the relationship between sperm quality and fertility, the methods of determining this association and conclusions vary. In the present study, computer-assisted sperm analysis (CASA) was used for evaluation of sperm motility, and differential interference contrast (DIC) microscopy was used for evaluating sperm morphologic features of breeding stallions. Fertility was measured using three endpoints: seasonal pregnancy rate (PR), percent pregnant/cycle (PC), and percent pregnant/first cycle (FCP). Increased total sperm motility (P = 0.08) and progressive path velocity (P = 0.06) tended to be associated with higher PR, whereas percent coiled tails (P = 0.02) was associated with a lower PR. Sperm motility variables associated with an increase in PC and FCP included total, progressive, and rapid sperm motility, and increased path and progressive velocity. Percent pregnant/first cycle was the only fertility measure able to discriminate among high, average, and low fertility groups, based on total and progressive sperm motility. Percent normal sperm was the only morphology variable associated with an increased PC and FCP, whereas increased levels of most sperm morphologic abnormalities (including abnormal and detached heads, proximal and distal droplets, general midpiece abnormality, and coiled tails) were associated with a decline in PC and FCP. Sperm quality variables most highly correlated with fertility included percent total sperm motility (PR, r = 0.37, P < 0.05; PC, r = 0.59, P < 0.05; and FCP, r = 0.64, P < 0.05), and percent morphologically normal sperm (PC, r = 0.42, P < 0.05; and FCP, r = 0.39, P < 0.05).

Myocardial MIBG scintigraphy may predict the course of motor symptoms in Parkinson’s disease

Background The metaiodobenzylguanidine (MIBG) scintigraphy is a well established nuclear medicine method to support the clinical diagnosis of Parkinson’s disease. In this study we examined the predictive value of the MIBG scintigraphy concerning the severity and progression of the parkinsonian motor symptoms. Patients and methods This study included 40 patients with idiopathic Parkinson’s disease (age 56 ± 9 years, Hoehn and Yahr stage 1.4 ± 0.7, mean ± standard deviation). All patients underwent a baseline visit and a follow-up visit 3–8 years (5.3 ± 1.6 years) after the baseline visit. 123I-MIBG scintigraphy was performed only once at the baseline visit. At both visits the motor symptoms bradykinesia, rigidity, resting tremor, postural tremor and axial symptoms were quantified by means of the motor part of the Unified Parkinson’s disease rating scale. Results The myocardial MIBG uptake correlated significantly with the annual progress of rigidity ( r = −0.41, p < 0.05; Pearson’s correlation) and axial symptoms ( r = −0.49, p < 0.01). There was no significant correlation ( p > 0.05) between the initial myocardial MIBG uptake and the annual progress of the other motor symptoms. Conclusion The MIBG scintigraphy may predict the velocity of progress of rigidity and axial symptoms in the following 3–8 years. Such a prediction is not possible for the other motor symptoms resting tremor, postural tremor and bradykinesia.

FP-CIT SPECT Does Not Predict the Progression of Motor Symptoms in Parkinson’s Disease

Background/Aims: FP-CIT (fluoropropyl-2β-carbomethoxy-3β-4-iodophenyl-nortroptane) SPECT is a well-established nuclear medicine method to support the clinical diagnosis of Parkinson’s disease (PD). In this study, we examined the prognostic value of FP-CIT SPECT concerning the PD motor symptoms. Methods: All 38 PD patients (age 57 ± 7 years, Hoehn & Yahr stage 1.6 ± 0.8, mean ± SD) underwent a baseline visit and a follow-up visit 3–7 years (5.2 ± 1.3 years) after the baseline visit. Cerebral [¹²³I]FP-CIT SPECT was performed only once at the baseline visit. At both visits the motor symptoms bradykinesia, rigidity, resting tremor, postural tremor and axial symptoms were quantified by means of the UPDRS motor scale. Results: There was no significant correlation between the initial striatal FP-CIT uptake and the annual progress of any motor symptom (= difference [(motor symptom at follow-up visit) – (motor symptom at baseline visit)]/time (in years) between assessments). Conclusion: The initial striatal FP-CIT SPECT does not predict the velocity of progress of PD motor symptoms within an interval of 3–7 years.

Kinetic analysis of stair descent: Part 1. Forwards step-over-step descent

This study examined lower extremity biomechanics during the initiation of stair descent from an upright, static posture. Seventeen healthy subjects (aged 23 ± 2.4 years) descended a five-step, steel-reinforced, wooden laboratory staircase (34° decline). Ten trials of stair descent were separated into two blocks of five trials. Beginning from an upright posture, subjects descended the staircase at their preferred velocity (0.53 ± 0.082 m/s) and continued the length of the laboratory walkway (∼4 m). Joint mechanics were contrasted between gait cycles. Relative to the initiation cycle at the top of the staircase, the dissipative knee extensor (K3) and hip flexor (H2) moments and powers were independent of progression velocity and approximated steady-state (i.e., constant) values after the first cycle of the trail limb (Step 5 to Step 3). In contrast, a salient relationship was observed between progression velocity and ankle joint mechanics at initial-contact. The plantiflexor moment, power and work at initial-contact (A1) increased with centre of mass velocity. Our results demonstrate that while the knee extensor moment is the primary dissipater of mechanical energy in stair descent, the ankle plantiflexors are the primary dissipaters associated with increased progression velocity. In addition, the results show that steady-state stair descent may not be attained during the first gait cycle of the trail limb. These data shed light on locomotive strategies used in stair descent and can be applied in biomechanical models of human stair gait. Researchers and practitioners should take into consideration the influence of gait cycle and progression velocity when evaluating lower extremity function in stair descent.

318 Factors determining the nature of progression of discrete fixed subaortic stenosis

In discrete fixed subaortic stenosis, surgery is indicated when the systolic gradient (Gmax) between the left ventricle (LV) and the aorta exceed 50 mmHg or in the presence of significant aortic regurgitation (AR). The aim of this study is to determine the factors that influence the progression of the obstruction and the appearance of AR. retrospective serial echocardiographic review of 19 patients, mean age 16 years (2 years-38 years), with fixed discrete subaortic stenosis that don’t require surgery (initial Gmax at inclusion <50 mmHg and without any symptom). The mean follow up was 5,42 years. The progression of gradient is defined by the formula (Gmax at follow up – initial Gmax) the mean velocity of increasing of Gmax was 2 mmHg/year. This progression was correlated to the patient's age (cut off = 15 years, r = −0,5; p = 0,02), and the initial value of the Gmax (cut off = 40 mmHg, r = 0,43; p = 0,04). The appearance or the aggravation of aortic regurgitation was determined by: the initial grade of AR (r = 0,64; p = 0,003), initial Gmax (r = 0,65; p = 0,002), progression's velocity of G max (r = 0,47; p = 0,04), and distance between the membrane and the aortic cusps (cut off = 5 mm, r = 0,49; p = 0,03). LV hypertrophy was influenced by the velocity of progression of obstruction (>2 mmHg/year) the identification of factors determining the evolution of discrete subaortic stenosis (age <15 years, initial Gmax >40 mmHg, distance membrane-cusps >5 mm) allows an adequate screening of patients that will require early operation.

How does rubber truly slide between Schallamach waves and stick–slip motion?

Abstract Schallamach waves have been investigated from a new viewpoint of their dynamic behaviour. Two new insights were introduced to elucidate the mechanism of the initiation and propagation of the wave of detachment, firstly the surface interaction force can produce a meniscus effect at the rubber surface and secondly the stick–slip motion can be seen to have a significant role during the sliding of rubber. The meniscus could perhaps be a source of the initiation of the wave of detachment at the leading edge and might have a role to play in the peeling of the rubber away from the trailing edge of the contact simultaneously. The characteristics in the propagation of the waves such as their frequency, their high progression velocity and the sliding velocity dependence all correlate with the periodic stick–slip motion. True finite sliding was observed to take place during a slip stage in the stick–slip motion whether waves of detachment appear or not on the contact area. Thus, the contribution of the waves to the frictional sliding of rubber is to decrease the contact area before true sliding and allow smoother sliding with less vibration of stick–slip motion to occur during rubber friction.

Impact of severe epilepsy on development: Recovery potential after successful early epilepsy surgery

Epilepsy surgery in young children with focal lesions offers a unique opportunity to study the impact of severe seizures on cognitive development during a period of maximal brain plasticity, if immediate control can be obtained. We studied 11 children with early refractory epilepsy (median onset, 7.5 months) due to focal lesion who were rendered seizure-free after surgery performed before the age of 6 years. The children were followed prospectively for a median of 5 years with serial neuropsychological assessments correlated with electroencephalography (EEG) and surgery-related variables. Short-term follow-up revealed rapid cognitive gains corresponding to cessation of intense and propagated epileptic activity [two with early catastrophic epilepsy; two with regression and continuous spike-waves during sleep (CSWS) or frontal seizures]; unchanged or slowed velocity of progress in six children (five with complex partial seizures and frontal or temporal cortical malformations). Longer-term follow-up showed stabilization of cognitive levels in the impaired range in most children and slow progress up to borderline level in two with initial gains. Cessation of epileptic activity after early surgery can be followed by substantial cognitive gains, but not in all children. In the short term, lack of catch-up may be explained by loss of retained function in the removed epileptogenic area; in the longer term, by decreased intellectual potential of genetic origin, irreversible epileptic damage to neural networks supporting cognitive functions, or reorganization plasticity after early focal lesions. Cognitive recovery has to be considered as a "bonus," which can be predicted in some specific circumstances.