The Association Between Pelvic Discomfort and Erectile Dysfunction in Adult Male Bicyclists.

BackgroundBicycle riding's impact on erectile function remains a topic of great interest given cycling's popularity as a mode of transportation and exercise.AimWe evaluated risk factors for sexual dysfunction in male cyclists with the primary intention of determining if genital/pelvic pain and numbness are associated with erectile dysfunction (ED).MethodsWe surveyed male cyclists using an online anonymous questionnaire. Cyclists were queried on their demographics, cycling experience, and sexual function using the Sexual Health Inventory for Men (SHIM). ED was diagnosed when a completed SHIM score was <22. Regression analysis was used to evaluate the risk of ED in men with genital/pelvic pain or numbness after riding. The survey was designed in the United States.OutcomesQuantitative characterization of cycling habits, onset and timing of genital pain and numbness, and SHIM score.ResultsA total of 1635 participants completed the survey. A majority of men were over the age of 50 (58%, 934/1,607), Caucasian (88%, 1,437/1,635), had been active cyclists for over 10 years (63%, 1,025/1,635) and used road bikes (97%, 1,578/1,635). Overall, 22%, 30%, and 57% of men reported ED, genital pain, and genital numbness, respectively. While controlling for cohort demographics, body mass index, cycling intensity and equipment, and medical comorbidities, no saddle characteristics were associated with the risk of developing genital numbness. However, men reporting penile numbness were at higher risk of reporting ED (odds ratio [OR] = 1.453, P = .048). In addition, quicker onset of numbness and resolution of numbness within a day was associated with impaired erectile function. For example, numbness occurring less than 1 hour after cycling had greater odds of leading to ED than numbness after 5 hours (OR = 2.002, P = .032). Similarly, genital pain occurring less than 1 hour (OR = 2.466, P = .031) after cycling was associated with higher ED risk.Strengths & limitationsStrengths include a large sample size of high-intensity cyclists and validated questionnaire use. Limitations include reliance on anonymous self-reported survey data and minimal inquiry into the riding preferences and terrain traversed by cyclists.ConclusionsPelvic pain and numbness are common complaints among male riders in the United States. Men with such complaints are more likely to also report ED especially if it occurs earlier in the ride. Although direction of causality and temporality are uncertain, alleviation of factors resulting in pelvic discomfort may reduce cycling's impact on sexual function. Such interventions are critical given that cycling for both active travel and aerobic exercise confers numerous health benefits. Balasubramanian A, Yu J, Breyer BN, et al. The Association Between Pelvic Discomfort and Erectile Dysfunction in Adult Male Bicyclists. J Sex Med 2020;17:919-929

Graphitization in chromium cast iron

peer reviewedSome trials with graphite Hi-Cr iron rolls have been done mainly in Japan, for the rolling of stainless steel. This material could lead to good compromise between oxidation, wear and thermal behaviour. By using thermal analysis and resistometry, the conditions for secondary graphite formation have been studied. The amount and volume of free graphite may be strongly increased by a suitable heat treatment, allowing a good thermal conductivity as well as high wear and mechanical properties

Cellular mechanisms of prostaglandin E2 and vasopressin interactions in the collecting duct

As the final segment of the nephron, the collecting duct is the ultimate regulator of renal salt and water excretion. Balance between intake and renal excretion of salt and water is fine-tuned by the action of several hormones targeted to the collecting duct. Vasopressin is, perhaps, the prototypical example of such a hormone. As total body water decreases and plasma osmolality rises, vasopressin secretion from the posterior pituitary increases [1]. Picomolar concentrations of circulating vasopressin lead to increased water permeability of the apical membrane of the collecting duct cell, resulting in increased water reabsorption and increased total body water [2,3]. There is abundant evidence demonstrating that vasopressin's effect on water reabsorption in the collecting duct is mediated through the classic second messenger, cAMP [3]. V2 selective receptors are linked via a G protein, to stimulation of plasma membrane adenylyl cyclase, resulting in increased cell cyclic AMP levels [4, 5]. The increased cyclic AMP then leads to augmented water permeability of the apical membrane [6, 7].As one might expect with such an important biologic process, other hormones and autocoids provide a counter-regulatory influence to modulate vasopressin mediated increases in osmotic water permeability. There is good evidence that the arachadonic acid metabolite, prostaglandin E2 (PGE2) plays a critical physiologic and pathophysiologic role in inhibiting vasopressin action in the collecting duct [8, 9]. Not only is the collecting duct the major renal site of synthesis for this cyclo-oxygenase product of arachidonic acid but PGE2 production is stimulated by vasopressin itself [10–12]. PGE2 infusion significantly blunts water reabsorption and cycloxygenase inhibition augments vasopressin antidiuresis [9, 13]. Thus, there is good evidence that the autocoid PGE2 plays an important role in regulating vasopressin-stimulated osmotic water flow

Genital Pain and Numbness and Female Sexual Dysfunction in Adult Bicyclists.

IntroductionBicycle seat pressure on the perineum may impair arousal and clitoral erection, likely contributing to genital pain and numbness experienced by female cyclists.AimWe aimed to identify the association between genital pain and numbness experienced by female cyclists and female sexual dysfunction (FSD).MethodsFemale cyclists were recruited to complete an online survey using the Female Sexual Function Index (FSFI), a validated questionnaire to assess FSD. Cyclist demographics, experience, preferred riding style, use of ergonomic cycle modifications, and genital discomfort while riding were also queried. Multivariate logistic regression analysis was used to evaluate risk factors of FSD.Main outcome measuresThe main outcome was FSFI score, which is used to diagnose FSD when the FSFI score is <26.55.ResultsOf the survey respondents, 178 (53.1%) completed the survey and FSFI questionnaire. Mean age was 48.1 years (±0.8 standard error [SE]), and the average riding experience was 17.1 years (±0.9 SE). Overall, 53.9% of female cyclists had FSD, 58.1% reported genital numbness, and 69.1% reported genital pain. After adjusting for age, body mass index, relationship status, smoking history, comorbidities, and average time spent cycling per week, females who reported experiencing genital numbness half the time or more were more likely to have FSD (adjusted odds ratio [aOR], 6.0; 95% CI, 1.5-23.6; P = .01), especially if localized to the clitoris (aOR, 2.5; 95% CI, 1.2-5.5; P = .02). Females that reported genital pain half the time or more while cycling also were more likely to have FSD (aOR, 3.6; 95% CI, 1.2-11.1; P = .02). Cyclists experiencing genital pain within the first hour of their ride were more likely to have FSD (aOR, 12.6; 95% CI, 2.5-63.1; P = .002). Frequency and duration of cycling were not associated with FSD. Analysis of FSFI domains found that the frequency of numbness was correlated with decreased arousal, orgasm, and satisfaction during intercourse, whereas the frequency of pain significantly reduced arousal, orgasm, and genital lubrication.Clinical implicationsFemale cyclists that experience numbness and/or pain have higher odds of reporting FSD.Strengths & limitationsOur study includes a validated questionnaire to assess FSD and queries specific characteristics and symptoms of genital pain and genital numbness; however, the study is limited by its cross-sectional survey design.ConclusionThis study highlights the need for cyclists to address genital pain and numbness experienced while cycling, and future studies are required to determine if alleviating these symptoms can reduce the impact of cycling on female sexual function. Greenberg GR, Khandwala YS, Breyer BN, et al. Genital Pain and Numbness and Female Sexual Dysfunction in Adult Bicyclists. J Sex Med 2019; 16:1381-1389

More Similarities Than Differences? An Exploratory Analysis Comparing the Sexual Complaints, Sexual Experiences, and Genitourinary Health of Older Sexual Minority and Sexual Majority Adults.

BackgroundLittle is known about sexual problems and genitourinary health of older sexual minority adults, who comprise up to 4% of the adult population but may differ in experiences of genitourinary aging, given known health disparities and behavior differences.AimTo examine and compare genitourinary and sexual complaints among older sexual minority and sexual majority adults.MethodsWe analyzed data from the 2010-2011 National Social Life, Health, and Aging Project (NSHAP), a nationally representative sample of older community-dwelling U.S. adults. Sexual minority men were defined as those who have sex with men or with both women and men. Sexual minority women were those who have sex with women or with both women and men. Descriptive statistics, weighted frequencies, and the chi-square test were used to compare outcomes by sexual orientation group and gender.Main outcome measuresStructured questionnaires examined sexual activity, practices, and genitourinary problems such as erectile dysfunction, insufficient vaginal lubrication, and urinary incontinence (UI).ResultsOf 2,813 participants (median age 69.6 years), 4.2% were sexual minorities (5.3% of men, 3.5% of women). Among men, sexual minorities were more likely to report UI (35.6% vs 21.8%; P = .029), but otherwise the 2 groups had similar prevalences of other urinary symptoms, importance of sexual activity, sexual practices, sexual activity within the last 3 months, and erectile difficulty (P > .10 for all). Among women, sexual minorities were more likely to report receiving oral sex (42.5% vs. 21.2%; P = .004), but otherwise the 2 groups had similar prevalences of UI, other urinary symptoms, importance of sexual activity, sexual activity within the last 3 months, and difficulty with lubrication (P > .10 for all).Clinical implicationsSexual activity and sexual problems may be as common among older sexual minority adults as in their sexual majority counterparts, whereas UI may be more common in sexual minority men compared with sexual majority men. Therefore, clinicians should employ culturally-relevant health screening, diagnosis, and treatment to ensure reaching all adults regardless of sexual orientation.Strengths & limitationsStrengths include a national population-based sample of older adults that describes sexual and genitourinary health. Statistical power was limited by the small numbers of sexual minority individuals.ConclusionHere we provide new evidence that older sexual minority men may experience UI more often than sexual majority men, and that sexual practices may differ between sexual minority and majority women, but frequency of sexual problems is similar. Given the challenges faced by sexual minority individuals in accessing equitable health care, clinicians must ensure that diagnosis and treatment are relevant to people of all sexual orientations. Obedin-Maliver J, Lisha N, Breyer BN. More Similarities Than Differences? An Exploratory Analysis Comparing the Sexual Complaints, Sexual Experiences, and Genitourinary Health of Older Sexual Minority and Sexual Majority Adults. J Sex Med 2019;16:347-350

In Memoriam: Clark Byse

The editors of the Harvard Law Review respectfully dedicate this issue to Professor Clark Byse

A major zebrafish polymorphism resource for genetic mapping

645,088 candidate polymorphisms in zebrafish were identified and positioned on genetic and physical maps as a resource for positional cloning