Effect of a 12-week mixed power training on physical function in dynapenic-obese older men: does severity of dynapenia matter?

INTRODUCTION: Mobility disability affects nearly 15% of people aged 65 or over worldwide. Excess weight or obesity (OB), along with an accentuated loss of muscle strength (dynapenia), is recognized to be one of the most common risk factors for mobility impairment among the elderly. OBJECTIVE: To investigate the effect of a 12-week mixed power training (MPT high-velocity resistance training mixed with functional exercises) on physical function in obese older men exhibiting different severities of dynapenia. METHODS: Community-dwelling older men (69 ± 6 years) were assigned to the study if they were considered obese (OB, fat mass ≥ 25% body weight, BW) and to one of the two groups according to severity of dynapenia [(handgrip strength-HS)/BW]: type 1(OB-DY1) or type 2(OB-DY2), < 1 or 2SD from a young reference group. Participants followed a 12-week MPT, three times/week, 75 min/session. Main outcomes included the performance on the 4-m and 6-min walking tests, Timed Up and Go, stair and balance tests. RESULTS AND DISCUSSION: At baseline, OB-DY1 performed better than OB-DY2 in all functional tests (p < 0.05). Following the intervention, medium-to-large training effect size (ES) were observed for fat (ES = 0.21) and lean (ES = 0.32, p < 0.001) masses, functional performance (ES 0.11-0.54, p < 0.05), HS (ES = 0.10, p < 0.05) and lower limb muscle strength (ES = 0.67, p < 0.001) and power (ES = 0.60, p < 0.05). Training-by-group interaction showed that OB-DY1 lost more FM (ES = 0.11, p = 0.03) and OB-DY2 improved more HS (ES = 0.19, p = 0.006) than their counterparts. CONCLUSIONS: Seniors with obesity and severe dynapenia have poorer physical function than those in the early stage of dynapenia. Both seem to benefit from a high-velocity resistance training mixed with functional exercises, although by slightly different pathways.

Genital Sensory Detection Thresholds and Patient Satisfaction With Vaginoplasty in Male-to-Female Transgender Women.

INTRODUCTION: Gender-affirming surgery is common for the treatment of gender dysphoria, but its effect on genital sensitivity is not well known. AIMS: To investigate genital sensory detection thresholds in male-to-female transgender women postoperatively and their relation to psychological well-being and variables of satisfaction. METHODS: Prospective study on 28 transgender women at least 18 years old operated on at least 3 months before the study by a single surgeon (N.M.J.). MAIN OUTCOME MEASURES: Medical complications; sensory detection thresholds for light touch, pressure, and vibration; and questionnaires on general and sexual satisfaction, sexual function, depression, and psychological well-being. RESULTS: Sensory detection thresholds ranged from 0.07 to 2.82 g for light touch, with the neck being most sensitive; from 20.23 to 34.64 g for pressure, with similar results for the neck and clitoris; and from 0.0052 to 0.0111 V for vibration, with similar findings for all stimulation points. Satisfaction with the appearance of the labia, vulva, clitoris, and sexual function was good to very good. Frequency of sexual activities increased significantly postoperatively for orogenital stimulation and decreased significantly for frequency of fantasies (t = -4.81; P < .0001). Orgasmic function was reported by 80% of participants. Psychological adjustment was good to very good, with low depression scores. Sexual satisfaction was statistically and positively correlated with vaginal function and depth, clitoral sensation, appearance of the vulva and labia minora, and natural lubrication and negatively correlated with depression scores. CONCLUSION: Gender-affirming surgery yields good results for satisfaction with appearance and function. Genital sensitivity showed the best results with pressure and vibration.

Simple model of a coherent molecular photocell.

Electron transport in molecular electronic devices is often dominated by a coherent mechanism in which the wave function extends from the left contact over the molecule to the right contact. If the device is exposed to light, photon absorption in the molecule might occur, turning the device into a molecular photocell. The photon absorption promotes an electron to higher energy levels and thus modifies the electron transmission probability through the device. A model for such a molecular photocell is presented that minimizes the complexity of the problem while providing a non-trivial description of the device mechanism. In particular, the role of the molecule in the photocell is investigated. It is described within the Hückel method and the source-sink potential approach [F. Goyer, M. Ernzerhof, and M. Zhuang, J. Chem. Phys. 126, 144104 (2007)] is used to eliminate the contacts in favor of complex-valued potentials. Furthermore, the photons are explicitly incorporated into the model through a second-quantized field. This facilitates the description of the photon absorption process with a stationary state calculation, where eigenvalues and eigenvectors are determined. The model developed is applied to various generic molecular photocells.

N-terminal entrance loop of yeast Yps1 and O-glycosylation of substrates are determinant factors controlling the shedding activity of this GPI-anchored endopeptidase.

BACKGROUND: S. cerevisiae Yps1 is the prototypical aspartic endopeptidase of the fungal yapsin family. This glycosylphosphatidylinositol (GPI) anchored enzyme was recently shown to be involved in the shedding of the GPI proteins Utr2, Gas1 and itself. It was also proposed to be part of a novel quality control mechanism that eliminates excess and/or misfolded GPI proteins. What regulates its shedding activity at the cell surface is however poorly understood. Yps1 is initially synthesized as a zymogen requiring proteolytic activation to remove a pro-peptide and further processing within a large insertion loop (N-entrance loop) generates a two-subunit endopeptidase. To investigate the role of this loop on its shedding activity, which typically takes place within Ser/Thr-rich domains, it was replaced with the short peptide found at the analogous position in Yps3. We also tested whether O-glycosylation might protect against proteolytic processing by Yps1. RESULTS: We show here that replacement of the N-entrance loop (N-ent loop) of Yps1 generates a single chain endopeptidase that undergoes partial (pH 6.0) or complete (pH 3.0) pro-peptide removal. At both pH, the shedding activity of the chimeric endopeptidase (Yps1-DL) toward Gas1 and itself is strongly and drastically increased, respectively. A direct correlation between endoproteolytic cleavage of this loop in native Yps1 and its shedding is observed. The Yps1-dependent shedding of two model GPI proteins (Gas1 and Yps1) is also stimulated by the absence of the O-mannosyltransferases, Pmt4 and Pmt2 respectively, involved in O-glycosylation of their Ser/Thr-rich domains. Under these conditions, some Yps1-independent shedding is also observed. CONCLUSIONS: Partial pro-peptide removal is essential to produce a functional Yps1 endopeptidase. The Yps1 N-ent loop plays a major role in regulating the shedding activity of the endopeptidase, most likely by limiting access to the active site, and its cleavage in native Yps1 is associated with its shedding. O-glycosylation protects against Yps1-dependent and -independent shedding of GPI proteins. It is postulated that hypoglycosylation of cell surface proteins, which may occur for misfolded proteins that escaped the ER-associated degradation, might target their elimination through shedding by Yps1 and possibly other yapsin members.

The assessment of sensory detection thresholds on the perineum and breast compared with control body sites.

INTRODUCTION: Few studies explored multiple sensory detection thresholds on the perineum and breast, but these normative data may provide standards for clinical conditions such as aging, genital and breast surgeries, pathological conditions affecting the genitals, and sexual function. AIMS: The aim of this study was to provide normative data on sensory detection thresholds of three sensory modalities on the perineum and breast. METHODS: Thirty healthy women aged between 18 and 35 years were assessed on the perineum (clitoris, labia minora, vaginal, and anal margin), breast (lateral, areola, nipple), and control body locations (neck, forearm, abdomen) for three sensory modalities (light touch, pressure, vibration). MAIN OUTCOME MEASURES: Average detection thresholds for each body location and sensory modality and statistical comparisons between the primary genital, secondary sexual, and neutral zones were the main outcome measures. RESULTS: Average detection thresholds for light touch suggest that the neck, forearm, and vaginal margin are most sensitive, and areola least sensitive. No statistical difference is found between the primary and secondary sexual zones, but the secondary sexual zone is significantly more sensitive than the neutral zone. Average detection thresholds for pressure suggest that the clitoris and nipple are most sensitive, and the lateral breast and abdomen least sensitive. No statistical difference is found between the primary and secondary sexual zone, but they are both significantly more sensitive than the neutral zone. Average detection thresholds for vibration suggest that the clitoris and nipple are most sensitive. The secondary sexual zone is significantly more sensitive than the primary and neutral zone, but the latter two show no difference. CONCLUSION: The current normative data from sensory detection threshold are discussed in terms of providing standard values for research and clinical conditions. Additional analysis from breast volume, body mass index, hormonal contraception, menstrual cycle, and sexual orientation do not seem to influence the results. Sexual abstinence and body piercing may have some impact.

Discussions of cancer clinical trials with the National Cancer Institute's Cancer Information Service.

Clinical trials are essential for the development of new and effective treatments for cancer; however, participation rates are low. One reason for this is lack of knowledge about clinical trials. This study assessed how often clinical trials are discussed on calls to National Cancer Institute's Cancer Information Service (CIS). The authors quantitatively analyzed 283,094 calls to the CIS (1-800-4-CANCER) over 3 years (2006-2008). They calculated descriptive statistics and multivariate regressions to determine whether specific caller characteristics are associated with the presence of a clinical trials discussion. In addition, 2 focus groups were conducted with CIS information specialists (n=12) to provide insight into the findings. The authors found that approximately 9.3% of CIS calls discussed clinical trials, with higher percentages for patients (12.5%) and family members (15.4%). Calls with Hispanics, Blacks, and Spanish speakers were less likely to include a conversation. For all cancers, patients who are in treatment or experiencing a recurrence were statistically significantly more likely to discuss clinical trials. CIS information specialists reported callers' limited knowledge of clinical trials. The CIS has the unique ability to make a substantial effect in educating patients about clinical trials as an option in cancer treatment and care.

Improved Human Muscle Biopsy Method To Study Neuromuscular Junction Structure and Functions with Aging.

Reduced mobility and physical independence of elders has emerged as a major clinical and public health priority with extended life expectancy. The impact of the neuromuscular function on muscle activity and properties has emerged as a critical factor influencing the progress and outcome of muscle changes with aging. However, very little is known about the neuromuscular junctions (NMJs) in humans, in part due to technical constraints limiting the access to healthy, fresh neuromuscular tissue. Here, we describe a method, called Biopsy using Electrostimulation for Enhanced NMJ Sampling (BeeNMJs) that improves the outcome of muscle biopsies. We used local cutaneous stimulation to identify the area enriched with NMJs for each participant at the right Vastus lateralis (VL). The needle biopsy was then performed in proximity of that point. The BeeNMJs procedure was safe for the participants. We observed NMJs in 53.3% of biopsies in comparison with only 16.7% using the traditional method. Furthermore, we observed an average of 30.13 NMJs per sample compared to only 2.33 for the traditional method. Importantly, high-quality neuromuscular material was obtained whereby pre-, postsynaptic, and glial elements were routinely labeled, simultaneously with myosin heavy chain type I. The BeeNMJs approach will facilitate studies of NMJs, particularly in human disease or aging process.

Blood pressure changes during sexual stimulation, ejaculation and midodrine treatment in men with spinal cord injury.

OBJECTIVES: To explore the effectiveness of various sources of self-stimulation, including oral midodrine, in triggering ejaculation in men with spinal cord injury (SCI), and to document the systematic variations in blood pressure at ejaculation and consider a revised definition of autonomic dysreflexia. PATIENTS AND METHODS: The study included 62 men with SCI lesions from C2 to L2. Ejaculation potential was assessed with various sources of stimulation, beginning with natural stimulation, followed, if the test was negative, by penile vibrator stimulation (PVS) followed, if the test was again negative, by PVS combined with oral midodrine, started at 5 mg and increased in 5 mg steps up to 25 mg. The success rate of ejaculation was recorded, as were blood pressure (BP) changes measured at baseline and at ejaculation (or on the last trial if the test was negative). Reported sensations were also recorded and compared during positive and negative tests. RESULTS: Overall, 89% of the patients reached ejaculation with one mode or another of stimulation. When patients had a negative result with natural stimulation, 56% were salvaged by PVS, and when PVS was negative, another 22% were salvaged by midodrine combined with PVS. The mean systolic BP increased by 35 mmHg at ejaculation during PVS and by 11 mmHg after midodrine, and a subsequent 29 mmHg at ejaculation during PVS combined with midodrine. By contrast, negative tests showed a relatively stable BP; the difference in changes in BP during positive and negative tests was significant (P < 0.01). Increases in BP during positive tests declined significantly more often within the limits of autonomic dysreflexia than negative tests (P < 0.01). CONCLUSION: These results support the view that most men with SCI can obtain an ejaculation when a wide spectrum of stimulation is used, including natural stimulation, PVS, and PVS combined with oral midodrine. Positive tests were associated with significant increases in BP, in contrast to negative tests, where BP was relatively stable. This suggests that significant changes in BP are required for ejaculation and that insignificant changes are predictive of future failure. As most changes in BP during positive tests also fall within the criterion of autonomic dysreflexia, a revised definition of autonomic dysreflexia should be considered to encourage safe experiences with ejaculation and safe use of midodrine.

Perceived physiological and orgasmic sensations at ejaculation in spinal cord injured men.

INTRODUCTION: With the advances in penile vibrator stimulation (PVS), most spinal cord injured (SCI) men can self-ejaculate. Oral midodrine may further increase ejaculation success, while maintaining autonomy. Since most SCI men attempt ejaculation for sexual rather than reproductive purposes, self-ejaculation should be emphasized and sensations explored. AIMS: Explore (i) self-ejaculation success rate in SCI men; (ii) vascular parameters indicative of autonomic dysreflexia (AD) during sexual stimulation and ejaculation; and (iii) sensations associated with ejaculation. METHODS: Ejaculation was assessed on 81 SCI men with complete ASIA A (49%) and incomplete B to D lesions (51%), subdivided into tetraplegics (C2-T2), paraplegics sensitive to AD (T3-T6), paraplegics not sensitive to AD (T7-T10), paraplegics with lesions to the emission pathway (T11-L2), and paraplegics with lesions interrupting the emission-ejaculation pathways (L3-below). Natural stimulation was attempted first followed, if negative, by PVS followed, if again negative, by PVS combined with oral midodrine (5-25 mg). MAIN OUTCOME MEASURES: Ejaculation success, systolic and diastolic blood pressure, and perceived physiological and orgasmic sensations. RESULTS: Overall 91% reached ejaculation, 30% with natural stimulation, 49% with PVS and 12% with midodrine plus PVS. Midodrine salvaged up to 27% depending upon the lesion. Physiological and orgasmic sensations were perceived significantly more at ejaculation than sexual stimulation. Tetraplegics did not differ from paraplegics sensitive to AD on perceived cardiovascular and muscular sensations, but perceived significantly more autonomic sensations, and generally more physiological sensations than lower lesions unsensitive to AD. CONCLUSION: Most SCI men can self-ejaculate and perceive physiological and orgasmic sensations. The climactic experience of ejaculation seems related to AD, few sensations being reported when AD is not reached, pleasurable climactic sensations being reported when mild to moderate AD is reached, and unpleasant or painful sensations reported with severe AD. Sexual rehabilitation should emphasize self-ejaculation and self-exploration and consider cognitive reframing to maximize sexual perceptions.

Effects of bilateral Achilles tendon vibration on postural orientation and balance during standing.

OBJECTIVE: Altering proprioceptive information in the lower limbs by vibration produces direction-specific falling and postural instability, which can persist after vibration stops. The objectives of this study were to describe the changes in trunk and lower limbs postural orientation and muscles activities during and after the end of bilateral Achilles tendon vibration (TV). METHODS: Twelve healthy young subjects were exposed to 30s periods of TV while blindfolded. Whole-body kinematics, kinetics and EMG of eight lower limb and trunk muscles were recorded prior, during and 5 or 25s after TV. RESULTS: TV during quiet standing produced a whole-body backward shift characterized by greater extension in the trunk and lower limbs. Five seconds after TV, two trends of recovery could be observed, either an overcorrection or undercorrection of the initial position. CONCLUSIONS: A continuum of postural orientations are adopted during and after vibration and the movements are not restricted to the ankle joints, despite the local nature of the proprioceptive stimulation. SIGNIFICANCE: The widespread influence of vibration as a proprioceptive stimulation when assessing its effects on posture and balance needs to be considered. Further studies should include whole-body analyses to document more thoroughly the postural strategies for balance maintenance during vibration.

Muscle strength and force development in high- and low-functioning elderly men: Influence of muscular and neural factors.

BACKGROUND: Aging leads to a loss of muscle strength and functional capacity likely resulting from a combination of neural and muscle alterations. The aim of this study was to identify possible disparities in muscle strength and force development profiles in high- and low-functioning elderly men and to investigate muscular and neurophysiological factors that could explain the differences. METHODS: Sixty community-dwelling men in good general health were divided in two groups based on a functional capacity (FC) z-score derived from 6 tests of the Short Physical Performance Battery and Senior Fitness Test (Normal and fast 4m-walk tests, normal and fast Timed-up and go, chair and stair tests). Extensor strength of the lower limbs (LL) was obtained for concentric (CLES) contraction and combined with lean masses of LL (LLLM) to yield concentric (CLES/LLLM) index. Similarly, extensor strength of the right Quadriceps Femoris (IKES) was obtained during maximal voluntary isometric contraction (MVC) and combined with right thigh lean mass (rTLM) to produce an isometric strength (IKES/rTLM) index. A muscular profile was obtained from: ascending and descending force slopes during the MVC; Vastus Lateralis (VL) muscle twitches parameters (amplitude, contraction and ½ relaxation times); the knee joint velocity (KV) as well as integrated EMG (iEMG) were determined for a sit-to-stand functional evaluation; muscle phenotype. A neurophysiological profile was established from: the spinal excitability (Hmax/Mmax ratio); motoneuron conduction velocity (CV); the completeness of muscle activation (% of force reserve), median power frequency (MPF) and mean amplitude (MA) of the VL EMG signal during MVC. RESULTS: Coincidently, age did not differ between groups. Strength and force indices, descending force slopes for MVC, KV and iEMG during the sit-to-stand evaluation and FC parameters were all significantly (p<0.05) lower in the LoFC group than in the HiFC group. In contrast, no difference was observed between groups in: LLLM and rTLM, Hmax/Mmax ratio, CV, twitch parameters and muscle phenotype. CONCLUSION: The lower concentric and isometric strengths found in the LoFC group could not be accounted for by muscular factors. Similarly, peripheral nervous systems alterations could not explain group differences. It can be suggested that modifications within the central nervous system may be responsible for the differences in the functional status of healthy elderly individuals. Finally, more complex and demanding tasks, such as those requiring greater intensity or coordination, may further clarify how healthy elderly individuals with low and high functional capacities differ.

The impact of ageing, physical activity, and pre-frailty on skeletal muscle phenotype, mitochondrial content, and intramyocellular lipids in men.

BACKGROUND: The exact impact of ageing on skeletal muscle phenotype and mitochondrial and lipid content remains controversial, probably because physical activity, which greatly influences muscle physiology, is rarely accounted for. The present study was therefore designed to investigate the effects of ageing, physical activity, and pre-frailty on skeletal muscle phenotype, and mitochondrial and intramyocellular lipid content in men. METHODS: Recreationally active young adult (20-30 yo; YA); active (ACT) and sedentary (SED) middle-age (50-65 yo; MA-ACT and MA-SED); and older (65 + yo; 65 + ACT and 65 + SED) and pre-frail older (65 + PF) men were recruited. Muscle biopsies from the vastus lateralis were collected to assess, on muscle cross sections, muscle phenotype (using myosin heavy chain isoforms immunolabelling), the fibre type-specific content of mitochondria (by quantifying the succinate dehydrogenase stain intensity), and the fibre type-specific lipid content (by quantifying the Oil Red O stain intensity). RESULTS: Only 65 + SED and 65 + PF displayed significantly lower overall and type IIa fibre sizes vs. YA. 65 + SED displayed a lower type IIa fibre proportion vs. YA. MA-SED and 65 + SED displayed a higher hybrid type IIa/IIx fibre proportion vs. YA. Sedentary and pre-frail, but not active, men displayed lower mitochondrial content irrespective of fibre type vs. YA. 65 + SED, but not 65 + ACT, displayed a higher lipid content in type I fibres vs. YA. Finally, mitochondrial content, but not lipid content, was positively correlated with indices of muscle function, functional capacity, and insulin sensitivity across all subjects. CONCLUSIONS: Taken altogether, our results indicate that ageing in sedentary men is associated with (i) complex changes in muscle phenotype preferentially affecting type IIa fibres; (ii) a decline in mitochondrial content affecting all fibre types; and (iii) an increase in lipid content in type I fibres. They also indicate that physical activity partially protects from the effects of ageing on muscle phenotype, mitochondrial content, and lipid accumulation. No skeletal specific muscle phenotype of pre-frailty was observed.

Electrical stimulation for therapy and mobility after spinal cord injury.

This article reviews the use of therapeutic and functional electrical stimulation in subjects after a spinal cord injury (SCI). Muscles become much weaker and more fatigable, while bone density decreases dramatically after SCI. Therapeutic stimulation of paralyzed muscles for about 1 h/day can reverse the atrophic changes and markedly increase muscle strength and endurance as well as bone density. Functional electrical stimulation can also improve the speed and efficiency of walking in people with an incomplete SCI. Finally, a modified wheelchair is described in which electrical stimulation or residual voluntary activation of leg muscles can produce movements of a footrest that is coupled to the wheels. The wheelchair can provide greater mobility and fitness to persons who are not functional walkers and currently use their arms to propel a wheelchair.

Effects of vibration in inline skating on the Hoffmann reflex, force, and proprioception.

PURPOSE: The objective of this study was to examine the effects of vibrations induced by inline skating on the Hoffmann (H) reflex, maximal voluntary isometric (MVC) force, and ankle proprioception. METHODS: Accelerometers were used to measure the frequencies and amplitudes of the vibrations encountered at the skate and mid-tibia levels. The soleus H reflex was recorded before and after (for 30 min) inline skating for 30 min. Maximal plantarflexor contractions were performed against a strain gauge while EMG was recorded from the soleus and medial gastrocnemius muscles. An ankle position-matching test was carried out to measure proprioception at the ankle. A Modified Borg Scale was used to obtain the appreciation of leg numbness and fatigue during inline skating. RESULTS: The vibrations measured at the skate chassis level had a mean frequency of 141.8 +/- 25.2 Hz and an amplitude of 35 min after skating. A 10% drop in MVC plantarflexor force was observed after inline skating. There was no accompanying change in EMG signal parameters. The ankle proprioception of the subjects decreased after skating, resulting in reproduction errors twice as large as before skating. CONCLUSION: Vibrations encountered during inline skating resulted in modifications of neuromotor functions related to the muscle spindles' primary afferent. These changes may partially be explained by presynaptic inhibition; however, a more plausible mechanism may be a decrease in the Ia afferent transmission induced by the vibration.

Effects of plantar cutaneo-muscular and tendon vibration on posture and balance during quiet and perturbed stance.

Modulation of lower limb somatosensory information by tendon or plantar vibration produces directionally specific, vibration-induced falling reactions that depend on the tendon or the region of the sole that is vibrated. This study characterized the effects of different patterns of plantar cutaneo-muscular vibration and bilateral Achilles tendon vibration (ATV) on the postural strategies observed during quiet and perturbed stance. Twelve healthy young participants stood barefooted, with their vision blocked, on two sets of plantar vibrators placed on two AMTI force plates embedded in a moveable support surface. Two other vibrators were positioned over the Achilles tendons. Participants were randomly exposed to different patterns of plantar cutaneo-muscular and ATV. Tilts of the support surface in the toes-up (TU) and toes-down (TD) directions were given 5-8s after the beginning of vibration. Body kinematics in 3D and ground reaction forces were recorded. Bilateral ATV applied with or without rearfoot vibration (RFV) during quiet stance resulted in a whole-body backward leaning accompanied by an increase in trunk extension and hip and knee flexion. RFV alone produced a forward whole-body tilt with increased flexion in trunk, hip, and ankle. When stance was perturbed by TU tilts, the center of mass (CoM) and center of pressure (CoP) displacements were larger in the presence of RFV or ATV and associated with increased peak trunk flexion. TD tilts with or without ATV resulted in no significant difference in CoM and CoP displacements, while larger trunk extension and smaller distal angular displacements were observed during ATV. RFV altered the magnitude of the balance reactions, as observed by an increase in CoP displacements and variable response in trunk displacement. Significant interactions between ATV and RFV were obtained for the peak angular excursions for both directions of perturbations, where ATV either enhanced (for TU tilts) or attenuated (for TD tilts) the influence of RFV. Manipulating somatosensory information from the plantar cutaneo-muscular and muscle spindle Ia afferents thus results in altered and widespread postural responses, as shown by profound changes in body kinematics and CoM and CoP displacements. This suggests that the CNS uses plantar cutaneo-muscular and ankle spindle afferent inputs to build an appropriate reference of verticality that influences the control of equilibrium during quiet and perturbed stance.

Chapter 16--spinal plasticity in the recovery of locomotion.

Locomotion is a very robust motor pattern which can be optimized after different types of lesions to the central and/or peripheral nervous system. This implies that several plastic mechanisms are at play to re-express locomotion after such lesions. Here, we review some of the key observations that helped identify some of these plastic mechanisms. At the core of this plasticity is the existence of a spinal central pattern generator (CPG) which is responsible for hindlimb locomotion as observed after a complete spinal cord section. However, normally, the CPG pattern is adapted by sensory inputs to take the environment into account and by supraspinal inputs in the context of goal-directed locomotion. We therefore also review some of the sensory and supraspinal mechanisms involved in the recovery of locomotion after partial spinal injury. We particularly stress a recent development using a dual spinal lesion paradigm in which a first partial spinal lesion is made which is then followed, some weeks later, by a complete spinalization. The results show that the spinal cord below the spinalization has been changed by the initial partial lesion suggesting that, in the recovery of locomotion after partial spinal lesion, plastic mechanisms within the spinal cord itself are very important.

H-reflex and physiologic measures of ejaculation in men with spinal cord injury.

OBJECTIVE: To investigate the various physiologic parameters characterizing and predicting ejaculation. DESIGN: Single case-control study. SETTING: A referred care center and university setting. PARTICIPANTS: Two men with spinal cord injury (SCI) and 2 control subjects. INTERVENTION: Subjects were asked to self-stimulate with a Ferticare vibrator to induce ejaculation over 5 to 8 independent sessions. MAIN OUTCOME MEASURES: Penile tumescence, blood pressure, heart rate, electromyographic activity of the bulbocavernosus muscles, abdominal muscles, soleus H-reflex, and occurrence of ejaculation. RESULTS: Changes on all measures were observed, with penile tumescence being more stable in control subjects. Blood pressure increased in both groups, whereas tachycardia was observed in controls and bradycardia in subjects with SCI. H-reflex dropped slightly in controls but increased in subjects with SCI. Muscular patterns differed on ejaculatory success or failure. CONCLUSIONS: Physiologic changes on all measures can be observed in men with SCI as a function of ejaculation. Changes include hypertension and bradycardia, characteristic of hyperreflexia, and tachycardia in controls. The neural mechanisms underlying these patterns are discussed. H-reflex showed increased spinal cord excitability in subjects with SCI after ejaculation, which suggests spasticity. The results support investigation of the H-reflex to predict ejaculatory success or failure in men with SCI, along with specific analysis of muscular patterns.

Web-based screening and brief intervention for the spectrum of alcohol problems.

CONTEXT: Many persons who drink excessively remain unidentified and do not receive interventions. Screening and intervention using the World Wide Web could make such services more accessible and therefore more widely used. OBJECTIVE: To evaluate the use of a novel alcohol screening and brief intervention Web site. DESIGN: A Web site was developed, posted, and its use was evaluated. We analyzed a sample of visitors who completed alcohol screening over a 14-month period to describe their alcohol use, and their use of portions of the Web site that provide information and referral resources. SETTING: The Internet. PATIENTS OR OTHER PARTICIPANTS: Web site visitors, with a focus on visitors who completed an alcohol-screening questionnaire about their own drinking. INTERVENTION: Brief intervention via the Web site, consisting mainly of feedback, advice, and a menu of change options and referral information. MAIN OUTCOME MEASURES: Self-reported drinking amounts and alcohol screening test scores, and utilization of Web site components. RESULTS: Visitors completed online alcohol screening questionnaires at a rate of 50,711/year of 115,925 visitors/year. In a 14-month period, 39,842 adults completed the questionnaire about their own drinking habits; 66% were men, 90% reported drinking hazardous amounts (per occasion or typical weekly amounts), 88% reported binge (per occasion) drinking, and 55% reported typically exceeding weekly risky drinking limits. Most (65%) had alcohol screening test results (AUDIT > or = 8) consistent with alcohol abuse or dependence; similar proportions of women and men were hazardous drinkers. One-fifth of visitors visited portions of the Web site that provided additional information about alcohol use and referrals. Visitors with possible alcohol abuse or dependence were more likely than those without these disorders to visit a part of the Web site designed for those seeking additional help (33% vs. 8%, P < 0.0001). CONCLUSIONS: A well-publicized, easily accessible, research-based screening and intervention Web site can attract many users, most of whom are drinking excessively, and many of whom avail themselves of referral information after receiving individualized feedback.