Nocturnal penile tumescence as a biologic marker in assessing erectile dysfunction

Recent findings challenge the belief that most cases of impotence are psychogenic. Research indicates that nocturnal penile tumescence (NPT) can be viewed as a biologic marker for physiologic erectile capacity. Thus, the test can help to distinguish between physicogenic and psychogenic impotence. To determine proximal causes of erectile failure, other evaluations are easily performed during NPT monitoring.     

Sleep of healthy seniors: a revisit

In an EEG sleep study of 40 healthy seniors (19 men and 21 women) aged 58-82 years, men could not maintain sleep as well as women and experienced less stage 3 sleep. The increased wakefulness after sleep onset among the men was particularly marked during the last 2 h of recording. REM density (during the first and second REM periods) showed an interaction of sex and age effects: thus, women in their 60s had higher REM density than men, whereas men in their 70s had higher REM density than women. In both men and women, however, regardless of age, the temporal distribution of REM sleep and REM density during the night was flat. Finally, only a mild degree of sleep-disordered breathing was noted, with positive age effects on apnea/hypopnea index and maximal duration of apnea. These findings are reviewed in relation to the sleep and aging literature.     

Psychophysiologic correlates of nocturnal penile tumescence in normal males

Despite increasing clinical reliance on nocturnal penile tumescence (NPT) testing for the differential diagnosis of male impotence, little is known at present about the relationship between NPT and other aspects of sleep and waking psychophysiology. This study investigated patterns of NPT, sleep, and EEG hemispheric asymmetry in 20 male subjects, using standard polysomnographic laboratory procedures for the assessment of sleep and NPT, and a method of EEG amplitude integration developed by Goldstein. Additionally, the effects of daytime sexual activity and mood state on the duration and amplitude of NPT were studied. Overall, the results of this study confirmed the well-documented relationship between NPT and stage REM, as well as demonstrating a strong association between NPT phase and nondominant hemisphere activation. Furthermore, this association appeared to strengthen over the course of the night. Hemispheric asymmetry and stage REM were also closely linked throughout. On the other hand, no significant correlations were found between daytime sexual activity or mood state and NPT. It is suggested that concurrent assessment of hemispheric asymmetry may strengthen the diagnostic power of NPT testing in impotence cases involving central organic etiology.     

Development of response-monitoring ERPs in 7- to 25-year-olds

In a target discrimination task, trials with incorrect responses elicit event-related potentials (ERPs) that include an error-related negativity (ERN or Ne) and a later error-positivity (Pe). Substantial evidence points to the anterior cingulate cortex as the source generator of the ERN. We examined the development of ERP component morphology, amplitude and latency to processing of correct and incorrect responses in 124 children, 7 to 18 years of age, and 27 adults, 19 through 25 years of age. The ERN and Pe were recorded during a standard 480-trial visual flanker task. As expected, response times decreased significantly with age. The ERN amplitude in error trials increased with age, although this was qualified by a nonlinear change as well. The Pe amplitude did not change with age. In correct trials, most participants produced a small negativity corresponding to the timing of the ERN in error trials. This correct-response negativity (CRN) amplitude was larger in children than in adults. Results are discussed with respect to continued maturation of the anterior cingulate cortex and prefrontal cortex into young adulthood.     

Human neutrophil kinetics: a call to revisit old evidence

The half-life of human neutrophils is still controversial, with estimates ranging from 7–9 h to 3.75 days. This debate should be settled to understand neutrophil production in the bone marrow (BM) and the potential and limitations of emergency neutropoiesis following infection or trauma. Furthermore, cellular lifespan greatly influences the potential effect(s) neutrophils have on the adaptive immune response. We posit that blood neutrophils are in exchange with different tissues, but particularly the BM, as it contains the largest pool of mature neutrophils. Furthermore, we propose that the oldest neutrophils are the first to die following a so-called conveyor belt model. These guiding principles shed new light on our interpretation of existing neutrophil lifespan data and offer recommendations for future research.     

Aerobic determinants of the decline in preferred walking speed in healthy, active 65- and 80-year-olds

The preferred walking speed is a common measure of mobility that declines with age and has been related to maximal oxygen uptake (O_2,max). The present study determined whether this decline is associated with a higher percentage of the ventilatory threshold in older adults walking at their preferred speed. We compared the preferred walking speed and O₂ at this speed in relation to both O_2,max and O₂ corresponding to the ventilatory threshold (T _VE) in healthy, physically active sexagenarians (G65, n=10) and octogenarians (G80, n=10) walking on a treadmill. The preferred walking speed was lower in G80 (1.16±0.09 m·s^–1) than in G65 (1.38±0.09 m·s^–1; P<0.001). Energy expenditure and the energy cost of walking at the preferred walking speed were not significantly different between the two groups. G80 subjects exhibited significantly higher fractions of O_2,max (60.8±8.0%) and T _VE (74.2±7.9%) at the preferred walking speed than G65 (42.9±5.0 and 53.2±5.7% respectively; P<0.001). Multiple regression analysis showed that the fraction of T _VE was the main determinant, with a small contribution of height, in the decline in the preferred walking speed in healthy and active elderly subjects (R ²=64%; P<0.001). These findings show that with age, walking at the preferred speed requires a higher fraction of T _VE. This increase in the relative physiological effort at preferred walking speed could explain the reduction in this gait speed in healthy older subjects.     

Nocturnal changes in knee cartilage thickness in young healthy adults

Magnetic resonance imaging (MRI) allows one to analyze cartilage physiology in vivo. Cartilage deforms during loading, but little is known about its recovery after deformation. Here we study 'nocturnal' changes in knee cartilage thickness and whether postexercise deformation differs between morning and evening. Axial magnetic resonance (MR) images were acquired in the right knees of 17 healthy volunteers (age 23.5 ± 3.0 years) after a normal day, and then after 30 deep knee bends. Coronal images were additionally acquired in 8 of these volunteers after a normal day and then after 2 min of static loading of the leg with 150% body weight. The volunteers then remained unloaded overnight and the same protocol was repeated in the morning. A significant increase (p < 0.01) in cartilage thickness was observed between evening (preexercise) and morning (preexercise): +2.4% in the patella, +8.4% in the medial tibia and +6.2% in the lateral tibia. Deformation in the morning (-6.8/ -4.6/-5.1%) was generally greater than that in the evening (-5.4/-3.2/-3.7%), but this difference did not reach statistical significance. No significant difference in the nocturnal thickness increase (or postexercise deformation) was observed between men and women. We conclude that knee cartilage (thickness) recovers overnight by approximately 2-8%, independent of sex. Given the lack of 'predeformation' after nocturnal periods of unloading, morning postexercise deformation of the cartilage may have a greater magnitude than evening postexercise deformation.     

Incidence and risk factors of insulin resistance syndrome in 20-59 year-old Korean male workers

We investigated the incidence of insulin resistance syndrome (IRS) according to the criteria of diagnoses suggested by the American College of Endocrinology/ American Association of Clinical Endocrinologists and the risk factors associated with the development of IRS. Among 2,048 subjects without a history of/or drug treatment for hypertension, diabetes, dyslipidemia with normal findings at baseline, 1,578 subjects aged 20-59 yr were followed prospectively for 2 yr. The incidence of IRS was 6.9 per 100 persons/year. The relative risk (RR) due to age was 1.03 (95% CI: 1.00-1.05) with every one-year increase in age. The RR associated with an abnormal waist-hip ratio group (> or =0.9) was increased by 1.74 (95% CI: 1.17-2.58) compared to the normal group (<0.9); RR associated with abnormal alanine transferase was increased (> or =35 IU/L) by 1.70 (95% CI: 1.20-2.41) compared to the normal group (<35 IU/L); and the RR associated with abnormal lowdensity lipoprotein (LDL) cholesterol was increased (> or =160 mg/L) by 1.70 (95% CI: 1.19-2.44) compared to the normal LDL cholesterol (<160 mg/L). Lastly, the RR of current smokers was increased by 1.63 (95% CI: 1.09-2.42) compared to that of non-smokers. It is necessary to develop methods of prevention and therapeutic approach to manage the integrated risk factors as opposed to individual factors.     

Terbinafine resistance in dermatophytes: Time to revisit alternate antifungal therapy

Resistant superficial dermatophytic infections of the skin and its appendages have emerged as a major health problem in India. Mutations in Squalene epoxidase gene have led to increasing incidence of resistance to terbinafine in dermatophytic isolates. We examined six patients with recalcitrant dermatophytosis attending Dermatology OPD at a tertiary care hospital and demonstrated terbinafine resistance by molecular method. Immediate hyperitivity (IH) reaction to Trichophytin antigen was highlighted in these patients. The patients were treated with alternate antifungals after demonstration of resistance to terbinafine based on the antifungal susceptibility testing (AFST). On follow up the patients responded well to the substitute but the duration of therapy had to be prolonged beyond six weeks.     

Arterial pressure and the risk factors in the 20- to 59-year-old male population (an epidemiological autopsy study in Riga)

1447 autopsies (87% of all deaths in the region) of males at the age from 20 to 59 years were analysed regardless of the cause of death. The first place among the causes of death belongs to the coronary heart disease and cerebrovascular pathology--31.7%. The prevalence of the arterial hypertension in the population was 14.2%, hypercholesterolemia --17.6%, smoking--82.7%, excess of body weight--8.6%, increased thickness of subcutaneous fat--39.4%, low physical activity--40%, diabetes mellitus--3%. The death from cardiovascular diseases among persons with hypertension was considerably more frequent that among persons with normal pressure. Systolic and diastolic arterial pressure was significantly higher in persons with the excess of weight, increase of fat thickness, hypercholesterolemia as well as in the group with coronary disease and cerebrovascular pathology as compared to the mean values in whole population.     

D2-40 immunoreactivity in penile squamous cell carcinoma: a marker of aggressiveness

D2-40 immunohistochemical expression was investigated in tissue specimens from 39 patients with squamous cell carcinoma of the penis who underwent partial or total penectomy between 1987 and 2008. Patient age, tumor size, and grade; D2-40-positive lymphatic vessel density in intratumoral, peritumoral, and normal tissue; cell positivity for D2-40 in intratumoral and normal tissue; and D2-40 staining intensity and distribution were analyzed and correlated with disease-specific survival. Analysis of D2-40-positive lymphatics disclosed that mean lymphatic vessel density was greater in peritumoral tissue than in intratumoral and normal tissue and lower in patients with lymph node metastasis than in those without lymph node metastasis. The receiver operating characteristic curve showed that an intratumoral lymphatic vessel density greater than 2.0 had 83.3% sensitivity and 78% specificity in predicting lymph node metastasis. Analysis of cell immunoreactivity showed cytoplasmic D2-40 positivity in intratumoral and normal tissue in 89.7% and 65.5% of patients, respectively. A strong correlation emerged between grade of cell differentiation and D2-40 immunoreactivity in intratumoral tissue; in particular, 88.9% of tumors with weak podoplanin expression were G1, whereas strong cellular immunoreactivity was detected in 83.3% of G3 patients (P = .003; χ(2) test). A significant correlation was also noted between pattern of reactivity and tumor grade because the basal layer was positive in patients with undifferentiated tumors (100% of G3) and in 72.2% of G1 tumors (P = .021; χ(2) test). D2-40 seems to be a useful marker for the development of node metastasis in squamous cell carcinoma of the penis, although validation in larger series is required to confirm its predictive value.     

Longitudinal changes in isokinetic leg strength in 10-14-year-olds

This study used multilevel regression modelling to longitudinally investigate the influences of age, sex, body size, skinfold thicknesses and maturity on the development of isokinetic knee extension and flexion on eight occasions over a 4-year period. Forty-one subjects (20 boys and 21 girls) were measured and 295 isokinetic leg strength tests and associated measures were successfully completed. Subjects were aged 10.0 +/- 0.3 years at the onset of the study. Stature, body mass, triceps and subscapular skinfold thicknesses, and sexual maturation (according to pubic hair development) were assessed at each test occasion. Isokinetic concentric knee extension and flexion of the dominant leg were determined to elicit maximal peak extension (PET) and flexion torque (PFT). Statistical significance was accepted at p < 0.05. Multilevel regression modelling indicated that stature and mass were significant predictors of both PET and PFT. Age and maturity were non-significant explanatory variables once stature and mass had been accounted for. Skinfold thickness exerted a significant negative effect independent of mass and stature on PFT but not PET. At test occasion 8, cross-sectional areas (CSAs) of the knee extensors (ExCSA) and flexors (FlexCSA) were determined using magnetic resonance imaging on 23 boys and 14 girls and examined as predictors of isokinetic leg strength. There were no significant sex-related differences in PET or PFT. Pearson product moment correlation coefficients indicated a significant relationship between ExCSA and PET and FlexCSA and PFT for both boys and girls. Analysis of covariance (ANCOVA) demonstrated that ExCSA and FlexCSA were significant explanatory variables for PET and PFT, respectively, but became non-significant once stature and mass had been introduced into the analysis. To conclude, there were no significant sex differences in PET or PFT between the ages of 10 and 14 years and the development of PET and PFT could be accounted for by the increase in stature and mass. Age, maturity and thigh muscle CSA were all non-explanatory variables in the production of PET and PFT once body size had been controlled for.     

Longitudinal changes in isokinetic leg strength in 10-14-year-olds

This study used multilevel regression modelling to longitudinally investigate the influences of age, sex, body size, skinfold thicknesses and maturity on the development of isokinetic knee extension and flexion on eight occasions over a 4-year period. Forty-one subjects (20 boys and 21 girls) were measured and 295 isokinetic leg strength tests and associated measures were successfully completed. Subjects were aged 10.0 &#45 0.3 years at the onset of the study. Stature, body mass, triceps and subscapular skinfold thicknesses, and sexual maturation (according to pubic hair development) were assessed at each test occasion. Isokinetic concentric knee extension and flexion of the dominant leg were determined to elicit maximal peak extension (PET) and flexion torque (PFT). Statistical significance was accepted at p < 0.05. Multilevel regression modelling indicated that stature and mass were significant predictors of both PET and PFT. Age and maturity were non-significant explanatory variables once stature and mass had been accounted for. Skinfold thickness exerted a significant negative effect independent of mass and stature on PFT but not PET. At test occasion 8, cross-sectional areas (CSAs) of the knee extensors (ExCSA) and flexors (FlexCSA) were determined using magnetic resonance imaging on 23 boys and 14 girls and examined as predictors of isokinetic leg strength. There were no significant sex-related differences in PET or PFT. Pearson product moment correlation coefficients indicated a significant relationship between ExCSA and PET and FlexCSA and PFT for both boys and girls. Analysis of covariance (ANCOVA) demonstrated that ExCSA and FlexCSA were significant explanatory variables for PET and PFT, respectively, but became non-significant once stature and mass had been introduced into the analysis. To conclude, there were no significant sex differences in PET or PFT between the ages of 10 and 14 years and the development of PET and PFT could be accounted for by the increase in stature and mass. Age, maturity and thigh muscle CSA were all non-explanatory variables in the production of PET and PFT once body size had been controlled for.     

Modulating peripersonal and extrapersonal reach space via tool use: a comparison between 6- to 12-year-olds and young adults

This study examined age-related characteristics associated with tool use in the perception and modulation of peripersonal and extrapersonal space. Seventy-six (76) children representing age groups 7-, 9-, 11 years and 36 adults were presented with two experiments using an estimation of reach paradigm involving arm and tool conditions and a switch-block of the opposite condition. Experiment 1 tested Arm and Tool (20 cm length) estimation and found a significant effect for Age, Space, and an Age × Space interaction (ps < 0.05). Both children and adults were less accurate in extrapersonal space, indicating an overestimation bias. Interestingly, the adjustment period during the switch-block condition was immediate and similar across age. Experiment 2 was similar to Experiment 1 with the exception of using a 40-cm-length tool. Results also revealed an age effect and a difference in Space (ps < 0.05), however, participants underestimated. Speculatively, participants were less confident when presented with a longer tool, even though the adjustment period with both tool lengths was similar. Considered together, these results hint that: (1) children as young as 6 years of age are capable of being as accurate when estimating reach with a tool as they are with their arm, (2) the adjustment period associated with extending and retracting spaces is immediate rather than gradual, and (3) tool length influences estimations of reach.