Perflubron emulsion increases subcutaneous tissue oxygen tension in rats

Saddle Pressures Factors in Road and Off-Road Cyclists of Both Genders: A Narrative Review

The contact point of the pelvis with the saddle of the bicycle could generate abnormal pressure, which could lead to injuries to the perineum in cyclists. The aim of this review was to summarize in a narrative way the current literature on the saddle pressures and to present the factors that influence saddle pressures in order to prevent injury risk in road and off-road cyclists of both genders. We searched the PubMed database to identify English-language sources, using the following terms: "saddle pressures", "pressure mapping", "saddle design" AND "cycling". We also searched the bibliographies of the retrieved articles. Saddle pressures are influenced by factors such as sitting time on the bike, pedaling intensity, pedaling frequency, trunk and hand position, handlebars position, saddle design, saddle height, padded shorts, and gender. The jolts of the perineum on the saddle, especially on mountain bikes, generate intermittent pressures, which represent a risk factor for various pathologies of the urogenital system. This review highlights the importance of considering these factors that influence saddle pressures in order to prevent urogenital system injuries in cyclists.

Strategies for Reducing the Impact of Cycling on the Perineum in Healthy Males: Systematic Review and Meta-analysis

Introduction

Perineal pressure associated with bicycle riding is the cause of several genitourinary pathologies, most notably Alcock’s syndrome and subsequent perineal numbness. The possible link between cycling-induced perineal numbness and erectile dysfunction makes the development of strategies for perineal protection in bicycle users critical.

Objective

To assess the effectiveness of strategies for reducing the impact of cycling on the perineum in healthy males.

Methods

We have conducted a systematic review and a meta-analysis of studies examining various means of reducing the impact of cycling on the perineum under the PRISMA guidelines.

Results

Out of 2217 screened studies, 22 met our inclusion criteria, and 6 qualified for meta-analysis. The strategies included various designs of saddles, changes in the cycling position, seat shock absorber, shorts with different padding, using the recumbent bike. Using the no-nose saddle and recumbent bike resulted in a significant reduction of perineal pressure and higher penile oxygen pressure compared with a standard saddle. Indirect evidence supports the protective effect of standing on the pedals every few minutes during cycling. More evidence is needed to support—or dismiss—other strategies.

Conclusions

Current evidence supports the use of no-nose saddles as a mean to reduce the negative impact of cycling on the perineum in healthy males at the cost of worse stability and increase of posterior seat pressure. Standing on the pedals every ten minutes might be an effective and potentially widely applicable strategy. The use of a recumbent bike appears to protect the perineum, but several concerns prevent its widespread use.

Electronic supplementary material

The online version of this article (10.1007/s40279-020-01363-z) contains supplementary material, which is available to authorized users.

A field study investigating sensory manifestations in recreational female cyclists using a novel female-specific cycling pad

This randomised controlled field study aimed to design a female-specific cycling pad with reduced padding in the crotch area (half-pad) and test its effects on self-reported sensory manifestations in comparison with full-padded cycling bib shorts. Recreational female road cyclists (n = 183) participated (divided into two groups). Self-reported sensory manifestations were collected six times over 12 weeks. Sitting discomfort, wetness perception, thermal, texture sensation, and wear discomfort decreased over time for the crotch and sitting-bones areas in both groups. Irritation and tenderness in the crotch area also decreased over time in both groups. Irritation and tenderness in the sitting-bones area were only higher at week two in the half-pad compared with the full-pad group. Cycling with the half-padded shorts compared with the full-padded ones had no negative effects on sensory manifestations beside the observed transient change at week two. This suggests that foam thickness in the crotch area can be reduced in female-specific cycling pads. Practitioner's Summary: Road cycling might result in discomfort and non-traumatic injuries in the female genital area. This field study compares two different cycling pads; a half-pad and a full-pad, over a 12-week period among female recreational road cyclists. Reducing the foam thickness in the crotch area of the pad does not change sensory manifestations, i.e. discomfort, wetness perception, texture-, and thermal-sensation as well as wear discomfort. Abbreviations: CS-Q: online Cycling bib Shorts Questionnaire; VADER: Valence Aware Dictionary and sEntiment Reasoner.

Prostatitis Syndromes and Sporting Activities

Introduction

Prostatitis-like syndromes are high prevalent health problems and frequently considered by patients and physicians as strictly correlated to sports causing perineal compression. These syndromes and their relationships with sporting activities have been discussed in this report.

Methods

We reviewed peer-reviewed scientific articles published by May 2009 and searched according to the following term selection: prostatitis, pudendal nerve, sport, cycling.

Results

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a major healthcare burden heavily affecting patients’ Quality of Life. No clear evidence of any direct etiologic relationship has been found in literature between prostatitis, either bacterial or non-bacterial, and sports activities. On the other hand, some types of sport causing perineal compression, such as cycling, can exacerbate symptoms of acute and chronic prostatitis; a temporary sport discontinuation is justified in these patients. CP/CPPS may be often caused by pudendal nerve entrapment (PNE). Prostatitis-like urogenital neuropathic pain together with voiding and sexual dysfunctions are the hallmark of PNE. A common feature is that flexion activities of the hip, such as climbing, squatting, cycling provoke or worsen urogenital pain or pelvic pain. Many of the patients with PNE are cyclists, played American football, lifted weights, or wrestled as teenagers and young adults. PNE represents the most common bicycling associated urogenital problems.

Conclusions

Overall, studies show that no causal relationship has been demonstrated between prostatitis and sporting activities. Conversely, urologists should be aware that sports involving vigorous hip flexion activities or prolonged perineal compression are a potential and not an infrequent cause of uroand rological symptoms caused by pudendal nerve entrapment.

Biomechanical Comparison of Shorts With Different Pads: An Insight into the Perineum Protection Issue

An intensive use of the bicycle may increase the risk of erectile dysfunction and the compression of the perineal area has been showed to be a major mechanism leading to sexual alterations compromising the quality of life. Manufacturers claim that pads contribute to increase cyclists perineal protection ensuring a high level of comfort. To investigate the influence of various cycling pads with regard to perineal protection and level of comfort. Nine club road cyclists rode 20 min on a drum simulator, located at the Nutrition and Exercise Physiology Laboratory, at a constant speed and gear ratio wearing the shorts with 3 cycling pads of different design and thickness: basic (BAS), intermediate (INT), and endurance (END). Kinematics and pressure data were recorded at min 5, 15, and 20 of the test using a motion capture system and a pressure sensor mat. The variables of interest were: 3-dimensional pelvis excursions, peak pressure, mean pressure, and vertical force. The comfort level was assessed with a ranking order based on the subjects' perception after the 20-min trials and measuring the vertical ground reaction force under the anterior wheel as well as the length of the center of pressure (COP) trajectory on the saddle. Results showed that the vertical force and the average value of mean pressure on the saddle significantly decreased during the 20-min period of testing for BAS and END. Mean peak pressure on the corresponding perineal cyclist area significantly increased only for BAS during the 20-min period. Interestingly objective comfort indexes measured did not match cyclists subjective comfort evaluation. The lower capacity of BAS to reduce the peak pressure on the corresponding perineal area after 20 min of testing, together with its positive comfort evaluation, suggest that a balance between protection and perceived comfort should be taken into account in the choice of the pad. Hence, the quantitative approach of objective comfort indexes introduced in this study could be helpful for manufacturers in the development of their protective pads.

Les lanternes rouges: the race for information about cycling-related female sexual dysfunction

INTRODUCTION

Cycling is growing in popularity among women. As in men, it is associated with genital neuropathies and decreased sensation in female riders. However, there is a gap in research and information addressing the relationship between cycling and female sexual dysfunction (FSD) in women.

AIMS

To review the literature investigating pelvic floor injuries and sexual dysfunction in female cyclists.

METHODS

Searches in several electronic databases were conducted, and relevant articles that met the inclusion criteria were identified for critical review.

MAIN OUTCOME MEASURES

The main outcome measure to be determined was the strength of the current body of evidence in published literature of a correlation between cycling-related pelvic floor injuries and FSD.

RESULTS

Data on FSD from cycling-related injuries in women are limited. Research indicates that bicycle setup and riding equipment may be contributing factors. Women's ergonomics and physiology interact differently with the bicycle than men's. Current evidence offers insufficient foundation to recommend various effect-mitigating equipment and products.

CONCLUSIONS

While gender-specific cycling products offer a promising direction for protecting women riders, studies addressing FSD and pelvic floor injuries in women cyclists are inadequate to indicate clear etiology or provide treatment recommendations. Current evidence is also insufficient to recommend effect-mitigating equipment and products.

Using C-arm x-ray imaging to guide local reporter probe delivery for tracking stem cell engraftment

Poor cell survival and difficulties with visualization of cell delivery are major problems with current cell transplantation methods. To protect cells from early destruction, microencapsulation methods have been developed. The addition of a contrast agent to the microcapsule also could enable tracking by MR, ultrasound, and X-ray imaging. However, determining the cell viability within the microcapsule still remains an issue. Reporter gene imaging provides a way to determine cell viability, but delivery of the reporter probe by systemic injection may be hindered in ischemic diseases. In the present study, mesenchymal stem cells (MSCs) were transfected with triple fusion reporter gene containing red fluorescent protein, truncated thymidine kinase (SPECT/PET reporter) and firefly luciferase (bioluminescence reporter). Transfected cells were microencapsulated in either unlabeled or perfluorooctylbromide (PFOB) impregnated alginate. The addition of PFOB provided radiopacity to enable visualization of the microcapsules by X-ray imaging. Before intramuscular transplantation in rabbit thigh muscle, the microcapsules were incubated with D-luciferin, and bioluminescence imaging (BLI) was performed immediately. Twenty-four and forty-eight hours post transplantation, c-arm CT was used to target the luciferin to the X-ray-visible microcapsules for BLI cell viability assessment, rather than systemic reporter probe injections. Not only was the bioluminescent signal emission from the PFOB-encapsulated MSCs confirmed as compared to non-encapsulated, naked MSCs, but over 90% of injection sites of PFOB-encapsulated MSCs were visible on c-arm CT. The latter aided in successful targeting of the reporter probe to injection sites using conventional X-ray imaging to determine cell viability at 1-2 days post transplantation. Blind luciferin injections to the approximate location of unlabeled microcapsules resulted in successful BLI signal detection in only 18% of injections. In conclusion, reporter gene probes can be more precisely targeted using c-arm CT for in vivo transplant viability assessment, thereby avoiding large and costly systemic injections of a reporter probe.

Fluorocapsules for improved function, immunoprotection, and visualization of cellular therapeutics with MR, US, and CT imaging

PURPOSE

To develop novel immunoprotective alginate microcapsule formulations containing perfluorocarbons (PFCs) that may increase cell function, provide immunoprotection for xenografted cells, and simultaneously enable multimodality imaging.

MATERIALS AND METHODS

All animal experiments were approved by an Institutional Animal Care and Use Committee. Cadaveric human islet cells were encapsulated with alginate, poly-l-lysine, and perfluorooctyl bromide (PFOB) or perfluoropolyether (PFPE). In vitro viability and the glucose-stimulation index for insulin were determined over the course of 2 weeks and analyzed by using a cross-sectional time series regression model. The sensitivity of multimodality (computed tomography [CT], ultrasonography [US], and fluorine 19 [(19)F] magnetic resonance [MR] imaging) detection was determined for fluorocapsules embedded in gel phantoms. C57BL/6 mice intraperitoneally receiving 6000 PFOB-labeled (n = 6) or 6000 PFPE-labeled (n = 6) islet-containing fluorocapsules and control mice intraperitoneally receiving 6000 PFOB-labeled (n = 6) or 6000 PFPE-labeled (n = 6) fluorocapsules without islets were monitored for human C-peptide (insulin) secretion during a period of 55 days. Mice underwent (19)F MR imaging at 9.4 T and micro-CT. Swine (n = 2) receiving 9000 PFOB capsules through renal artery catheterization were imaged with a clinical multidetector CT scanner. Signal intensity was evaluated by using a paired t test.

RESULTS

Compared with nonfluorinated alginate microcapsules, PFOB fluorocapsules increased insulin secretion of encapsulated human islets, with values up to 18.5% (3.78 vs 3.19) at 8-mmol/L glucose concentration after 7 days in culture (P < .001). After placement of the immunoprotected encapsulated cells into mice, a sustained insulin release was achieved with human C-peptide levels of 19.1 pmol/L ± 0.9 (standard deviation) and 33.0 pmol/L ± 1.0 for PFPE and PFOB capsules, respectively. Fluorocapsules were readily visualized with (19)F MR imaging, US imaging, and CT with research- and clinical-grade imagers for all modalities.

CONCLUSION

Fluorocapsules enhance glucose responsiveness and insulin secretion in vitro, enable long-term insulin secretion by xenografted islet cells in vivo, and represent a novel contrast agent platform for multimodality imaging.

Bicycle riding and erectile dysfunction: a review

INTRODUCTION

For many years, reports in the literature have implicated bicycle riding as causing increased risk of erectile dysfunction (ED). Perineal compression during cycling has been associated with the development of sexual complications.

AIM

To review current literature on the rationale for ED from bicycle riding and outcome of bicycle riding on erectile function and to present available research on preventative measures specifically regarding bicycle riding.

METHODS

A systematic comprehensive literature review.

RESULTS

There is a significant relationship between cycling-induced perineal compression leading to vascular, endothelial, and neurogenic dysfunction in men and the development of ED. Research on female bicyclists is very limited but indicates the same impairment as in male bicyclists. Preventative measures including use of a properly fitted bicycle, a riding style with a suitable seat position and an appropriate bicycle seat can help prevent impairment of erectile function.

CONCLUSIONS

There is a need for further research on safe bicycle and bicycle seat design and investigations that address the underlying mechanisms leading to cycling-related sexual dysfunction in both male and female bicyclists.

A field-based approach for examining bicycle seat design effects on seat pressure and perceived stability

The purpose of this study was to investigate the effect of various bicycle seat designs on seat pressure and perceived stability in male and female cyclists using a unique field-based methodology. Thirty participants, comprising male and female cyclists, pedaled a bicycle at 118W over a 350m flat course under three different seat conditions: standard seat, a seat with a partial anterior cutout, and a seat with a complete anterior cutout. The pressure between the bicycle seat and perineum of the cyclist was collected with a remote pressure-sensing mat, and perceived stability was assessed using a continuous visual analogue scale. Anterior seat pressure and stability values for the complete cutout seat were significantly lower (p<0.05; 62-101%) than values for the standard and partial cutout designs. These findings were consistent between males and females. Our results would support the contention that the choice of saddle design should not be dictated by interface pressure alone since optimal anterior seat pressure and perceived seat stability appear to be inversely related.