12,691 research outputs found
Endocrinologic Control of Men's Sexual Desire and Arousal/Erection
Several hormones and neurotransmitters orchestrate men's sexual response, including the appetitive (sexual desire) and consummative (arousal and penile erection) phases.
AIM:
To provide an overview and recommendations regarding endocrinologic control of sexual desire and arousal and erection and their disturbances.
METHODS:
Medical literature was reviewed by the subcommittee of the International Consultation of Sexual Medicine, followed by extensive internal discussion, and then public presentation and discussion with other experts. The role of pituitary (prolactin, oxytocin, growth hormone, and α-melanocyte-stimulating hormone), thyroid, and testicular hormones was scrutinized and discussed.
MAIN OUTCOME MEASURES:
Recommendations were based on grading of evidence-based medical literature, followed by interactive discussion.
RESULTS:
Testosterone has a primary role in controlling and synchronizing male sexual desire and arousal, acting at multiple levels. Accordingly, meta-analysis indicates that testosterone therapy for hypogonadal individuals can improve low desire and erectile dysfunction. Hyperprolactinemia is associated with low desire that can be successfully corrected by appropriate treatments. Oxytocin and α-melanocyte-stimulating hormone are important in eliciting sexual arousal; however, use of these peptides, or their analogs, for stimulating sexual arousal is still under investigation. Evaluation and treatment of other endocrine disorders are suggested only in selected cases.
CONCLUSION:
Endocrine abnormalities are common in patients with sexual dysfunction. Their identification and treatment is strongly encouraged in disturbances of sexual desire and arousal
A dot-blot assay for the low density lipoprotein receptor.
We describe a new method for detecting the interaction of low density lipoprotein with its receptor using unmodified nitrocellulose as support for membrane protein. The method is specific and sensitive down to 3 micrograms of membrane protein. Unlabeled LDL, but not HDL, competes with 125I-labeled LDL for binding, and binding is abolished by pretreatment of the membranes with pronase and is dependent upon the presence of Ca2+. Furthermore, modification of arginine or lysine residues on LDL abolishes the lipoprotein interaction with the receptor protein supported on the nitrocellulose. When the membranes are solubilized with octyl glucoside, purification steps of the receptor can be directly followed with no interference of the detergent, therefore eliminating the need for its removal. The increased expression of LDL receptors on liver membranes from estradiol-treated rats was also demonstrated. We suggest, therefore, that this method can be used to detect the presence of LDL receptors on minute amounts of membrane protein
Trophic compensation stabilizes marine primary producers exposed to artificial light at night
Artificial light at night (ALAN) is a widespread phenomenon along coastal areas. Despite in - creasing evidence of pervasive effects of ALAN on patterns of species distribution and abundance, the potential of this emerging threat to alter ecological processes in marine ecosystems has remained largely unexplored. Here, we show how exposure to white LED lighting, comparable to that experienced along local urbanized coasts, significantly enhanced the impact of grazing gastropods on epilithic microphytobenthos (MPB). ALAN increased both the photo-synthetic biomass of MPB and the grazing pressure of gastropods, such that consumers compensated for the positive effect of night lighting on primary producers. Our results indicate that trophic interactions can provide a stabilizing compensatory mechanism against ALAN effects in natural food webs
Self-consistent pedestal prediction for JET-ILW in preparation of the DT campaign
The self-consistent core-pedestal prediction model of a combination of EPED1 type pedestal prediction and a simple stiff core transport model is able to predict Type I ELMy (edge localized mode) pedestals of a large JET-ILW (ITER-like wall) database at the similar accuracy as is obtained when the experimental global plasma beta is used as input. The neutral penetration model [R. J. Groebner et al., Phys. Plasmas 9, 2134 (2002)] with corrections that take into account variations due to gas fueling and plasma triangularity is able to predict the pedestal density with an average error of 15%. The prediction of the pedestal pressure in hydrogen plasma that has higher core heat diffusivity compared to a deuterium plasma with similar heating and fueling agrees with the experiment when the isotope effect on the stability, the increased diffusivity, and outward radial shift of the pedestal are included in the prediction. However, the neutral penetration model that successfully predicts the deuterium pedestal densities fails to predict the isotope effect on the pedestal density in hydrogen plasmas
Identification of onosma visianii roots extract and purified shikonin derivatives as potential acaricidal agents against tetranychus urticae
There is an increasing need for the discovery of reliable and eco-friendly pesticides and natural plant-derived products may play a crucial role as source of new active compounds. In this research, a lipophilic extract of Onosma visianii roots extract containing 12% of shikonin derivatives demonstrated significant toxicity and inhibition of oviposition against Tetranychus urticae mites. Extensive chromatographic separation allowed the isolation of 11 naphthoquinone derivatives that were identified by spectral techniques and were tested against Tetranychus urticae. All the isolated compounds presented effects against the considered mite and isobutylshikonin (1) and isovalerylshikonin (2) were the most active, being valuable model compounds for the study of new anti-mite agents
Editorial: New Insights in Skeletal Muscle Channelopathies - A Rapidly Expanding Field
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