SciCombinator

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Concept: Ejaculation

204

Spontaneous ejaculation, which is defined as the release of seminal fluids without apparent sexual stimulation, has been documented in boreoeutherian mammals. Here we report spontaneous ejaculation in a wild Indo-Pacific bottlenose dolphin (Tursiops aduncus), and present a video of this rare behavior. This is the first report of spontaneous ejaculation by an aquatic mammal, and the first video of this behavior in animals to be published in a scientific journal.

Concepts: Bottlenose dolphin, Ejaculation

167

OBJECTIVE: To investigate the efficacy of DA-8031, a novel compound for the treatment of premature ejaculation (PE), we performed in vivo pharmacological studies using 2 preclinical animal models, electrical stimulation of sensory branch of pudendal nerve (SBPdn) and para-chloroamphetamine (PCA)-induced ejaculation model. METHODS: First of all, in electrical stimulation of an SBPdn model, an SBPdn in the pelvic canal of the spinal cord transected from rats was identified. Then an electromyogram (EMG) of the bulbospongiosus (BS) muscle was recorded during electrical stimulation of SBPdn after single intravenous (IV) dosing of DA-8031 and its reference drug, dapoxetine. In the second model, both seminal vesicle pressure (SVP) and the EMG profile of the BS muscle were recorded in PCA-induced ejaculation animals after treated with the same dosing regimen. RESULTS: Area under the curve (AUC) of the BS muscle by EMG wave exhibited a significant reduction in the DA-8031 and dapoxetine 3 mg/kg treated groups, and maximum amplitudes were also significantly decreased in DA-8031 1, 3 mg/kg and dapoxetine 3 mg/kg dose level in the SBPdN stimulation model. Consistent with these findings, in a PCA-induced ejaculation model, SVP increase was significantly inhibited from DA-8031 0.3 mg/kg dose level, and AUC of BS muscle EMG significantly decreased in the DA-8031 1, 3 mg/kg groups. CONCLUSION: The present study implied that DA-8031 contributed to an effective co-coordinated inhibition of the expulsion phase of ejaculation by modulating BS muscle activity and the emission phase through blocking SVP rise. From these findings, DA-8031 is further expected to have clinical efficacy in human studies.

Concepts: Semen, Electromyography, Orgasm, Ejaculation, Penis, Premature ejaculation, Pudendal nerve, Bulbospongiosus muscle

145

Premature ejaculation (PE) is one of the most prevalent yet under-reported sexual disorders. Differing sociocultural norms across the Asia-Pacific region provide unique challenges in PE management.

Concepts: Orgasm, Ejaculation, Penis, Premature ejaculation, Sexual dysfunction, Asia-Pacific, Bangkok, Asia-Pacific Economic Cooperation

143

In non-azoospermic patients with low semen volume (LSV), looking for partial retrograde ejaculation (PRE) by searching sperm in the postejaculatory urine (PEU) is required. The use of a retro-ejaculatory index (R-ratio) was suggested to define PRE, but none of the studies indicated a specific threshold above which PRE must be considered. Our objective was to propose a threshold value for the R-ratio as indicative of PRE in patients with LSV selected to be devoid of any known causes or risk factors for retrograde ejaculation or LSV. Among our data base (2000-2009) including 632 patients with PEU, 245 male patients from infertile couples who had had a first semen analysis with LSV (< 2mL) and a second semen analysis associated with PEU, were selected on the previous criteria. A prospective control group was randomly constituted (2007-2008) of 162 first consulting male patients from infertile couples, with a normal semen volume (≥ 2mL) on a first semen analysis and who accepted to collect PEU with their usual second semen analysis, selected on the previous criteria. To define an R-ratio threshold indicative of PRE, we used a ROC curve analysis and a regression tree based on a classification and regression tree (CART) algorithm. Of the 245 LSV patients, 146 still presented low semen volume (< 2 mL) on the second semen analysis. From the use of the CART algorithm, two low (1.5% and 2.8%) and two high R-values (7.1% and 8.3%) were defined, according to the lower reference limit for semen volume of 2.0 mL (WHO 1999) or 1.5 mL (WHO 2010) respectively. As only one or no patient with normal semen volume was observed above the two high R-values, we suggest an R-value higher than the range of [7.1-8.3]% as indicative of PRE until confirmation by a prospective multicenter study.

Concepts: Scientific method, Sperm, Semen, Receiver operating characteristic, Orgasm, Ejaculation, Retrograde ejaculation, Anejaculation

143

A 19 year old presented with a progressive decline in ejaculate volume over 2 weeks, followed by a complete absence of ejaculate emission. A post-ejaculatory urine specimen demonstrated spermatozoa confirming a diagnosis of retrograde ejaculation. Investigations revealed a raised blood glucose level of 24.5 mmol/L and HbA1c >15%, with positive tests for anti-GAD antibodies and anti-IA2 antibodies consistent with a diagnosis of Type 1 diabetes mellitus. Retrograde ejaculation in diabetes is associated with autonomic neuropathy and is a late feature of the disease. This case is unique with retrograde ejaculation being the primary presenting symptom of Type 1 diabetes mellitus.

Concepts: Diabetes mellitus, Diabetes, Blood sugar, Semen, Orgasm, Ejaculation, Retrograde ejaculation, Anejaculation

142

To assess the correlation between penile hypersensitivity and premature ejaculation (PE), a total of 420 consecutive subjects attending our andrologic clinic for suspected PE were enrolled. The entire cohort was asked to complete the self-report intravaginal ejaculation latency time (IELT) by stopwatch. According to the IELT, the subjects were classified into 3 groups. Vibratory thresholds were recorded at the glans penis and penile shaft using a biothesiometer. We found that vibratory thresholds in the glans penis and penile shaft were significantly lower in both mild and severe PE group than in the control group (3.81 ± 0.57 and 3.54 ± 0.43 vs 4.73 ± 0.77 for glans penis p = 0.000; 3.64 ± 0.52 and 3.37 ± 0.50 vs 4.62 ± 0.69 for penile shaft p = 0.002). The vibratory threshold decreased as the disease aggravated. In the mild and severe PE groups, a significant positive correlation was detected between the mean values of IELT and the vibratory thresholds. Furthermore, in the receiver operating characteristics curve analysis, the area under the curve of the glans penis and penile shaft vibratory thresholds predicting severe PE were 0.852 and 0.893 respectively. Our study established a dose-dependent association between penile vibratory threshold and PE. Therefore, the vibratory threshold can serve as a potential marker for predicting the severity of PE.

Concepts: Andrology, Receiver operating characteristic, Orgasm, Ejaculation, Penis, Premature ejaculation, Glans penis, Intravaginal ejaculation latency time

43

Precise spatiotemporal control of physiological processes by optogenetic devices inspired by synthetic biology may provide novel treatment opportunities for gene- and cell-based therapies. An erectile optogenetic stimulator (EROS), a synthetic designer guanylate cyclase producing a blue-light-inducible surge of the second messenger cyclic guanosine monophosphate (cGMP) in mammalian cells, enabled blue-light-dependent penile erection associated with occasional ejaculation after illumination of EROS-transfected corpus cavernosum in male rats. Photostimulated short-circuiting of complex psychological, neural, vascular, and endocrine factors to stimulate penile erection in the absence of sexual arousal may foster novel advances in the treatment of erectile dysfunction.

Concepts: Sexual intercourse, Andrology, Erectile dysfunction, Ejaculation, Penis, Cyclic guanosine monophosphate, Erection, Sexual arousal

41

Several factors have been shown to influence semen parameters, one of which is sexual abstinence; a clinical criteria included in the semen evaluation to provide maximum sperm quality. The aim of the present study was to assess the effect of a daily ejaculation frequency on conventional and functional semen parameters.

Concepts: Sexual intercourse, Evaluation, Sperm, Semen analysis, Spermatozoon, Semen, Ejaculation, Masturbation

38

Human semen contains spermatozoa secreted by the testes and a mixture of components produced by the bulbo-urethral and Littre (paraurethral) glands, prostate, seminal vesicles, ampulla and epididymis. Ejaculation is used as a synonym for the external ejection of semen, but it comprises two phases: emission and expulsion. As semen collects in the prostatic urethra, the rapid preorgasmic distension of the urethral bulb is pathognomonic of impeding orgasm, and the man experiences a sensation that ejaculation is inevitable (in women, emission is the only phase of orgasm). The semen is propelled along the penile urethra mainly by the bulbocavernosus muscle. With Kegel exercises, it is possible to train the perineal muscles. Immediately after the expulsion phase the male enters a refractory period, a recovery time during which further orgasm or ejaculation is physiologically impossible. Age affects the recovery time: as a man grows older, the refractory period increases. Sexual medicine experts consider premature ejaculation only in the case of vaginal intercourse, but vaginal orgasm has no scientific basis, so the duration of intercourse is not important for a woman’s orgasm. The key to female orgasm are the female erectile organs; vaginal orgasm, G-spot, G-spot amplification, clitoral bulbs, clitoris-urethra-vaginal complex, internal clitoris and female ejaculation are terms without scientific basis. Female sexual dysfunctions are popular because they are based on something that does not exist, i.e. the vaginal orgasm. The physiology of ejaculation and orgasm is not impaired in premature ejaculation: it is not a disease, and non-coital sexual acts after male ejaculation can be used to produce orgasm in women. Teenagers and men can understand their sexual responses by masturbation and learn ejaculatory control with the stop-start method and the squeeze technique. Premature ejaculation must not be classified as a male sexual dysfunction. It has become the center of a multimillion dollar business: is premature ejaculation - and female sexual dysfunction - an illness constructed by sexual medicine experts under the influence of drug companies? This article is protected by copyright. All rights reserved.

Concepts: Sexual intercourse, Semen, Prostate, Orgasm, Ejaculation, Penis, Male reproductive system, Masturbation

28

The aim of the study is to investigate whether there is an effect of adult circumcision on ejaculation parameters and to research the relationship between intravaginal ejaculation latency time (IELT) and premature ejaculation diagnostic tool (PEDT). Adults who underwent voluntary circumcision between September 2010 and November 2011 were enrolled in this prospective study. The IELT before and 3 months following circumcision was recorded. Also, PEDT was filled out before and 3 months after circumcision. During statistical evaluation, the comparison of situations before and after circumcision was made using IELT averages and PEDT total scores. Furthermore, the correlation between changes in IELT and PEDT has also been evaluated. A total of 30 volunteers (mean age 21.25±0.44) were enrolled in the study. The volunteers' mean and median IELT before were 104.36±66.21 and 88 (26-307) seconds, whereas mean and median IELT after circumcision were 123.56±54.44 and 107.5 (67-300) seconds, respectively. The increase after circumcision was statistically significant (P=0.001). The mean and median PEDT score were 4.26±2.91 and 3 (1-12) before, and 2.63±1.82 and 2 (0-7) after circumcision. Improvement was statistically significant (P<0.0001). No correlation could be found between ejaculation time and PEDT scores. Circumcision during adulthood does not adversely affect ejaculatory function; it may slightly improve. However, it could not be interpreted as a justification for circumcision in men with premature ejaculation (PE).International Journal of Impotence Research advance online publication, 2 January 2014; doi:10.1038/ijir.2013.47.

Concepts: Statistics, Arithmetic mean, Mean, Ejaculation, Penis, Premature ejaculation, Sexual dysfunction, Intravaginal ejaculation latency time