Management of Erectile Dysfunction in the Hypogonadal Man: A Case-Based Review

Erectile dysfunction (ED) has emerged as an important marker of cardiovascular and overall health, independent of other known conventional risk factors. ED often precedes coronary artery disease in half of affected subjects, and could indicate the presence of cardiovascular pathology. The pathophysiology and role of androgens in sexual function are described, along with the relevant literature on the effects of aging in erectile and gonadal function. The concept of testosterone supplementation (TST) in men with ED is reviewed. The authors utilize clinical vignettes to discuss the appropriate management of two clinical cases of men at different life stages who have ED in the setting of hypogonadism and propose a treatment algorithm. In patients of all ages, proper identification of the underlying pathophysiology of decreased libido and erectile function is paramount in choosing between the use of TST, phosphodiesterase type 5 inhibitors, or both, in the management of these disorders.Key words: Erectile dysfunction, Testosterone supplementation, Hypogonadism, Phosphodiesterase type 5 inhibitorsErectile dysfunction (ED) has emerged as an important marker of cardiovascular and overall health, independent of other known conventional risk factors. Because ED often precedes coronary artery disease (CAD) in half of affected subjects, it may be considered a harbinger of indolent cardiovascular pathology.^1,2 The modulation of erectile function by testosterone is well known,^3,4 and in men with both hypogonadism and ED a treatment strategy necessitating management of both conditions is required.Phosphodiesterase type 5 inhibitors (PDE5i) and testosterone supplementation therapy (TST) are established treatment strategies for ED and hypogonadism, respectively. Using a PDE5i in combination with TST has the potential for improving efficacy in men with concurrent ED and hypogonadism compared with the use of either agent alone. However, in light of the recent evidence associating testosterone with cardiovascular risk in elderly men,^5,6 TST should be used judiciously in the management of ED in older men.     

Les dysfonctions érectiles chez le diabétique: Rôle des facteurs neurologiques

Objective

To assess the etiological factors of erectile dysfunction in male diabetics.

Material and methods

We have performed a prospective evaluation including 69 diabetic patients suffering from erectile dysfunction. Studied parameters including age, type and duration of diabetes, complications, treatments and associated risk factors were analysed. Comparison was done with a control group of 138 diabetic patients without erectile dysfunction.

Results

There was a significant difference between the diabetic with neurologic complications and the others without neuropathy (p=0.0004). The duration of the diabete was was another risk factor of erectile dysfunction (p=0.049)

Conclusion

We confirm various authors who demonstrated that diabetic impotence seems to be mainly neuropathic in etiology even though it was a multifactorial discomfort.     

Berberine Ameliorate Oxidative Stress and Astrogliosis in the Hippocampus of STZ-Induced Diabetic Rats

Diabetes mellitus increases the risk of central nervous system (CNS) disorders such as stroke, seizures, dementia, and cognitive impairment. Berberine, a natural isoquinoline alkaloid, is reported to exhibit beneficial effect in various neurodegenerative and neuropsychiatric disorders. Moreover, astrocytes are proving critical for normal CNS function, and alterations in their activity and impaired oxidative stress could contribute to diabetes-related cognitive dysfunction. Metabolic and oxidative insults often cause rapid changes in glial cells. Key indicators of this response are increased synthesis of glial fibrillary acidic protein (GFAP) as an astrocytic marker. Therefore, we examined the effects of berberine on glial reactivity of hippocampus in streptozotocin (STZ)-induced diabetic rats, using GFAP immunohistochemistry. Lipid peroxidation, superoxide dismutase (SOD) activity, and nitrite levels were assessed as the parameters of oxidative stress. Eight weeks after diabetes induction, we observed increased numbers of GFAP⁺ astrocytes immunostaining associated with increased lipid peroxidation, decreased superoxide dismutase activity, and elevated nitrite levels in the hippocampus of STZ-diabetic rats. In contrast, chronic treatment with berberine (50 and 100 mg/kg p.o. once daily) lowered hyperglycemia, reduced oxidative stress, and prevented the upregulation of GFAP in the brain of diabetic rats. In conclusion, the present study demonstrated that the treatment with berberine resulted in an obvious reduction of oxidative stress and GFAP-immunoreactive astrocytes in the hippocampus of STZ-induced diabetic rats.

DFT study of the Lewis acid mediated synthesis of 3-acyltetramic acids

The recent emergence and re-emergence of alphaviruses, in particular the chikungunya virus (CHIKV), in numerous countries has invoked a worldwide threat to human health, while simultaneously generating an economic burden on affected countries. There are currently no vaccines or effective drugs available for the treatment of the CHIKV, and with few lead compounds reported, the vital medicinal chemistry is significantly more challenging. This study reports on the discovery of potential inhibitors for the nsP3 macro domain of CHIKV using molecular docking, virtual screening, and molecular dynamics simulations, as well as work done to evaluate and confirm the active site of nsP3. Virtual screening was carried out based on blind docking as well as focused docking, using the database of 1541 compounds from NCI Diversity Set II, to identify hit compounds for nsP3. The top hit compounds were further subjected to molecular dynamic simulations, yielding a greater understanding of the dynamic behavior of nsP3 and its complexes with various ligands, concurrently confirming the outcomes of docking, and establishing in silico lead compounds which target the CHIKV nsP3 enzyme.

Les inhibiteurs de la phosphodiestérase de type 5 : une révolution dans le traitement des sympt?mes du bas appareil urinaire?

Context

The incidence of lower urinary tract symptoms (LUTS) related to benign prostatic hyperplasia (BPH) increases with age, affecting 50% of patients aged over 50 years and 90% of those aged over 80 years. The prevalence and severity of erectile dysfunction (ED) also increase with age. Its prevalence is estimated to be 31.6% in men over 40 years. LUTS as well as ED significantly affect the quality of life of patients and their partners. Several studies have shown that LUTS represent an independent risk factor for ED. The severity of LUTS is correlated with that of ED. The pathophysiological hypothesis linking LUTS to ED are an increase in sympathetic tone, alteration of NO/cGMP system, alteration of rho kinase system, and pelvic atherosclerosis.

Goal

Some treatments of LUTS have adverse effects on the erectile function. The phosphodiesterase type 5 inhibitors (IPDE 5) revolutionized the treatment of ED.

Material and methods

Several recent clinical studies evaluated the effect of daily treatment by IPDE 5 on LUTS secondary to BPH among patients with or without ED.

Results

This review shows that IPDE 5 administration improves LUTS significantly in 12 randomized clinical trials, as well as in both storage and voiding parts of the international prostate symptom score (IPSS) and in quality of life questionnaire. No adverse events were observed, and ED, which has a high prevalence among this population, was also improved.

Conclusion

The treatment of LUTS by IPDE 5 looks very promising, even though they are not yet approved for this indication in France.     

Theoretical study of the solvatochromism of a donor-acceptor bithiophene

The solvation and the solvatochromic behavior of the 5-(methylthio)-5′-nitro-2,2′-bithiophene 1 in diethyl ether, dichloromethane, acetonitrile, methanol and formamide was theoretically investigated with an iterative molecular and quantum mechanics (QM/MM) approach. Calculated longest-wavelength solvatochromic absorption band of 1, obtained as averages of statistically uncorrelated configurations, including the solute and explicit solvent molecules of the first and second solvation layer, were in excellent agreement with the experimental results.

In vitro inhibitory profile of NDGA against AChE and its in silico structural modifications based on ADME profile

Acetylcholinesterase (AChE) inhibitors are currently in focus for the pharmacotherapy of Alzheimer’s disease (AD). These inhibitors increase the level of acetylcholine in the brain and facilitate cholinergic neurotransmission. AChE inhibitors such as rivastigmine, galantamine, physostigmine and huperzine are obtained from plants, indicating that plants can serve as a potential source for novel AChE inhibitors. We have performed a virtual screening of diverse natural products with distinct chemical structure against AChE. NDGA was one among the top scored compounds and was selected for enzyme kinetic studies. The IC₅₀ of NDGA on AChE was 46.2 μM. However, NDGA showed very poor central nervous system (CNS) activity and blood–brain barrier (BBB) penetration. In silico structural modification on NDGA was carried out in order to obtain derivatives with better CNS activity as well as BBB penetration. The studies revealed that some of the designed compounds can be used as lead molecules for the development of drugs against AD

Dysfonction érectile et diabète : fréquence et profil clinique à partir de 200 observations

Purpose

Erectile dysfunction is one of the most frequent complications in diabetes and also the most often under diagnosed. We report the prevalence of erectile dysfunction in 200 diabetic patients.

Patients and methods

Prevalence was estimated by the French version of the International Index of Erectile Function 5 (IIEF5).

Results

146 patients were included. Erectile dysfunction concerned 74 patients; a severe form was observed in 21.6%, a moderate in 37.8% and a mild one in 40.6%. The patients who presented erectile dysfunction were significantly older and displayed longer duration of diabetes.

Conclusion

Erectile dysfunction is frequent and severe among diabetic patients. The medical staff plays an essential role to initiate early diagnosis, promote psychological support and provide medication, when possible.     

Therapeutic ultrasound as a potential male contraceptive: power, frequency and temperature required to deplete rat testes of meiotic cells and epididymides of sperm determined using a commercially available system

Background

Carbamazepine (CBZ) is a first-line antiepileptic drug (AED), although it is also used for the treatments of psychiatric disorders and neuropathic pain. The CBZ utilization has been associated with male reproductive damage, including hormonal alterations, sexual dysfunction and reduction of sperm quality. The wide and long-term use of the CBZ is a common schedule in children and adolescents and alters the testosterone level in adult rats and humans. The objective of this work was to evaluate the CBZ side effects on the ventral prostate of rats from pre-puberty to sexual maturation, since the prostate is an androgen-dependent organ.

Methods

Twenty three day-old male albino Wistar rats received CBZ diluted in propylene glycol (20 mg/Kg/i.p via). The treatment lasted 20, 40 and 70 days, according to the different stages of the rat sexual maturation. At the end of each treatment period, ventral prostates were removed and histologically processed. The prostate sections were submitted to the histopathological, morphological and stereological analyses using image analysis system.

Results

Reductions of the glandular epithelium, glandular lumen and fibromuscular stroma volume of the ventral prostate were observed in adult rats treated with CBZ since the weaning. Triggering and degranulation of mast cells were observed in the fibromuscular stroma of prepubertal and pubertal CBZ treated rats.

Conclusions

The results suggest a direct effect of the CBZ on rat ventral prostate, evidenced by increase of mast cell and macrophage populations during pre-puberty and puberty causing a ventral prostate accentuated damage in the adult phase.     

Priapisme veineux: traitement et pronostic fonctionnel. A propos de 26 cas

Introduction

Priapism is a prolonged, painful and persistent erection, unrelated to sexual stimulation. The management of priapism is complex and requires various medical or surgical treatments. The authors review the aetiology, treatment and outcome of priapism.

Material and methods

26 cases of low-flow priapism were collected over a period of 23 years (1985–2007), corresponding to 22 adults and 4 children (average age: 32 years) with various types of priapism. The time to appropriate management after onset of priapism varied according to the aetiology and the time to consultation (range: 16 hours to 15 days).

Results

Complete and persistent detumescence for the first 24 hours was obtained in 84% of cases, sometimes with multiple successive procedures. No case of early recurrence was observed. 21 patients were regularly followed for a period of 3 months to 10 years (mean follow-up: 2 years). There were 9 (42.9%) successes (recovery of normal erectile function), 4 partial results (19%) and 9 (30.1%) failures (complete erectile dysfunction).

Conclusion

Low-flow priapism must be considered to be a serious andrological emergency. Medical treatment can be effective in early forms, but surgery must not be delayed to prevent permanent erectile dysfunction secondary to extensive corpora cavernosa fibrosis.     

A molecular dynamics study on sI hydrogen hydrate

A molecular dynamics simulation is carried out to explore the possibility of using sI clathrate hydrate as hydrogen storage material. Metastable hydrogen hydrate structures are generated using the LAMMPS software. Different binding energies and radial distribution functions provide important insights into the behavior of the various types of hydrogen and oxygen atoms present in the system. Clathrate hydrate cages become more stable in the presence of guest molecules like hydrogen.

Molecular dynamics analysis of a series of 22 potential farnesyltransferase substrates containing a CaaX-motif

Protein farnesyltransferase (FTase) is an important target in many research fields, more markedly so in cancer investigation since several proteins known to be involved in human cancer development are thought to serve as substrates for FTase and to require farnesylation for proper biological activity. Several FTase inhibitors (FTIs) have advanced into clinical testing. Nevertheless, despite the progress in the field several functional and mechanistic doubts on the FTase catalytic activity have persisted. This work provides some crucial information on this important enzyme by describing the application of molecular dynamics simulations using specifically designed molecular mechanical parameters for a variety of 22 CaaX peptides known to work as natural substrates or inhibitors for this enzyme. The study involves a comparative analysis of several important molecular aspects, at the mechanistic level, of the behavior of substrates and inhibitors at the dynamic level, including the behavior of the enzyme and peptides, as well as their interaction, together with the effect of the solvent. Properties evaluated include the radial distribution function of the water molecules around the catalytically important zinc metal atom and cysteine sulfur of CaaX, the conformations of the substrate and inhibitor and the corresponding RMSF values, critical hydrogen bonds, and several catalytically relevant distances. These results are discussed in light of recent experimental and computational evidence that provides new insights into the activity of this enzyme.

La dysfonction éréctile au Sénégal: Profil épidemiologique

Methodology

This was a transverse randomized survey of subjects over the age of 18 years. Subjects completed a self-administered questionnaire composed of two parts. The first part contained information on demographic characteristics, associated diseases, erectile dysfunction and associated sexual disorders and the second part was based on IIEF5. Two groups were identified: a group with erectile dysfunction (ED group) and another group without erectile dysfunction (No ED group). Differences between the two groups were considered to be statistically significant for p ≤ 0.05 on the Chi-square test.

Results

The global prevalence of erectile dysfunction was 26%. The prevalence by age-group revealed a progressive increase of ED with age from 11% between 20 and 30 years to 76% between 70 and 80 years. The rate of polygamous men was significantly higher in the group with ED (29.2%) compared to the group without ED (6.6%) (p < 0.0001) and the severity of ED increased in relation to the number of wives. Chronic alcoholism was significantly more frequent in the group with ED (p = 0.023). The frequency of ED increased with the duration of cigarette smoking from 11.9% for less than 5 years, 16.9% between 5 years and 10 years and 71.2% for more than 10 years. Some diseases (diabetes, hypertension and depression) were significantly more frequent in the group with ED. Analysis of the type of ED revealed that secondary erectile dysfunction was more frequent (95.6%) than primary erectile dysfunction (4.4%). Associated sexual disorders were significantly more frequent in the group with ED.     

Penile Rehabilitation Strategies Among Prostate Cancer Survivors

Despite advances in technical and surgical approaches, erectile dysfunction (ED) remains the most common complication among prostate cancer survivors, adversely impacting quality of life. This article analyzes the concept and rationale of ED rehabilitation programs in prostate cancer patients. Emphasis is placed on the pathophysiology of ED after diagnosis and treatment of prostate cancer to understand the efficacy of rehabilitation programs in clinical practice. Available evidence shows that ED is a transient complication following prostate biopsy and cancer diagnosis, with no evidence to support rehabilitation programs in these patients. A small increase in ED and in the use of phosphodiesterase type 5 (PDE5) inhibitors was reported in patients under active surveillance. Patients should be advised that active surveillance is unlikely to severely affect erectile function, but clinically significant changes in sexual function are possible. Focal therapy could be an intermediate option for patients demanding treatment/refusing active surveillance and invested in maintaining sexual activity. Unlike radical prostatectomy, there is no support for PDE5 inhibitor use to prevent ED after highly conformal external radiotherapy or low-dose rate brachytherapy. Despite progress in the understanding of the pathophysiologic mechanisms responsible for ED in prostate cancer patients, the success rates of rehabilitation programs remain low in clinical practice. Alternative strategies to prevent ED appear warranted, with attention toward neuromodulation, nerve grafting, nerve preservation, stem cell therapy, investigation of neuroprotective interventions, and further refinements of radiotherapy dosing and delivery methods.Key words: Prostate cancer, Erectile dysfunction, Penile rehabilitation, Phosphodiesterase type 5 inhibitor, Prostaglandin E₁In the United States, prostate cancer is the most frequently diagnosed nonskin cancer in men, and is second only to lung cancer as a cause of cancer death.¹ In 2014, an estimated 233,000 men in the United States were diagnosed with a prostate cancer and 29,480 men were expected to die from their disease.² In the prostate-specific antigen (PSA) era, the importance of this type of cancer becomes evident when considering that more young, sexually active men are being diagnosed at an early stage while the tumor is still organ confined. Early detection of prostate cancer in the PSA era, as well as improvements in systemic treatment of metastatic prostate cancer, has led to an increased life expectancy; but cancer diagnosis and treatment carry serious physical and psychological consequences that can dramatically decrease quality of life.³ However, these results had recently drawn the attention of the scientific community to the quality of life of cancer survivors in order to promote health as defined by the World Health Organization (WHO).⁴ Despite advances in technical and surgical approach, erectile dysfunction (ED) remains the most common and the most documented complication among prostate cancer survivors, adversely impacting quality of life.⁵ ED is also a prevalent long-term complication among prostate cancer patients receiving systemic therapy.⁶ In recent years, investigators have increasingly focused on ED in prostate cancer patients. They have directed their efforts toward searching for interventions that might improve erectile function. Various coping strategies and rehabilitation programs have been suggested and applied with different success rates.This article provides an overview of the literature, analyzing the concept and rationale of rehabilitation programs for ED in prostate cancer patients. Emphasis is placed on the pathophysiology of such disorders after diagnosis and treatment of prostate cancer in order to understand the efficacy of rehabilitation programs in clinical practice.     

Phosphodiesterase 4 inhibitors and drugs of abuse: current knowledge and therapeutic opportunities

Background

Long-term exposure to drugs of abuse causes an upregulation of the cAMP-signaling pathway in the nucleus accumbens and other forebrain regions, this common neuroadaptation is thought to underlie aspects of drug tolerance and dependence. Phosphodiesterase 4 (PDE4) is an enzyme that the selective hydrolyzes intracellular cAMP. It is expressed in several brain regions that regulate the reinforcing effects of drugs of abuse.

Objective

Here, we review the current knowledge about central nervous system (CNS) distribution of PDE4 isoforms and the effects of systemic and brain-region specific inhibition of PDE4 on behavioral models of drug addiction.

Methods

A systematic literature search was performed using the Pubmed.

Results

Using behavioral sensitization, conditioned place preference and drug self-administration as behavioral models, a large number of studies have shown that local or systemic administration of PDE4 inhibitors reduce drug intake and/or drug seeking for psychostimulants, alcohol, and opioids in rats or mice.

Conclusions

Preclinical studies suggest that PDE4 could be a therapeutic target for several classes of substance use disorder. We conclude by identifying opportunities for the development of subtype-selective PDE4 inhibitors that may reduce addiction liability and minimize the side effects that limit the clinical potential of non-selective PDE4 inhibitors. Several PDE4 inhibitors have been clinically approved for other diseases. There is a promising possibility to repurpose these PDE4 inhibitors for the treatment of drug addiction as they are safe and well-tolerated in patients.

     

Discovery of novel low-molecular-weight HIV-1 inhibitors interacting with cyclophilin A using in silico screening and biological evaluations

Cyclophilin A has attracted attention recently as a new target of anti-human immunodeficiency virus type 1 (HIV-1) drugs. However, so far no drug against HIV-1 infection exhibiting this mechanism of action has been approved. To identify new potent candidates for inhibitors, we performed in silico screening of a commercial database of more than 1,300 drug-like compounds by using receptor-based docking studies. The candidates selected from docking studies were subsequently tested using biological assays to assess anti-HIV activities. As a result, two compounds were identified as the most active. Specifically, both exhibited anti-HIV activity against viral replication at a low concentration and relatively low cytotoxicity at the effective concentration inhibiting viral growth by 50 %. Further modification of these molecules may lead to the elucidation of potent inhibitors of HIV-1.

Why tazobactam and sulbactam have different intermediates population with SHV-1 β-lactamase: a molecular dynamics study

The imine intermediates of tazobactam and sulbactam bound to SHV-1 β-lactamase were investigated by molecular dynamics (MD) simulation respectively. Hydrogen bond networks around active site were found different between tazobactam and sulbactam acyl-enzymes. In tazobactam imine intermediate, it was observed that the triazolyl ring formed stable hydrogen bonds with Asn170 and Thr167. The results suggest that conformation of imine determined the population of intermediates. In imine intermediate of tazobactam, the triazolyl ring is trapped in Thr_Asn pocket, and it restricts the rotation of C5-C6 bond so that tazobactam can only generate trans enamine intermediate. Further, conformational cluster analyses are performed to substantiate the results. These findings provide an explanation for the corresponding experimental results, and will be potentially useful in the development of new inhibitors.

Une approache pratique des résistances psychologiques aux traitements par injections intracaverneuses (I.I.C.)

Intra-cavernous injection of vasoactive substances has dramatically modified the medical approach of erectile dysfunction. There are psychological and ethical difficulties to this therapeutic procedure, and it is likely that they do contribute to the high drop out rate encountered with this method. According to our clinical experience, we suggest several attitudes in order to facilitate patient's and partner's acceptance:

? There is no opposition between psychotherapy and intra-cavernous injection, they may be regarded as complementary.

? It is advisable to find means to reduce the fear induced by self injection, by reassuring the patient, and making the act easier by choosing the most simple injection material. The pharmacological action must be explained, as well as the side effects.

? Pharmacologically induced erection is often described as artificial, although intra-cavernous injection of vasoactive substances is a symptomatic treatment just as many other symptomatic treatments. It compensates a functional insufficiency, restoring a physiological state very close to normal as far as erection is concerned, but has no effect on sexual excitation, glans intumescence and the development of the ejaculatory climax reflex. The sexuel relation's erotization lays only within the couple, and remains entirely apart from any iatrogenic effect.

? Should the treatment remain secret? Inta-cavernous injection must not systematically be performed withtout the partner knowing about it, although the act should remain discrete and intimate.

One should not encounter psychic or ethical difficulties in erectile dysfunction treatment with intra-cavernous injection of vasoactive substances, provided that it has been properly prescribed, well explained, and that it is part of a psychotherapy. It is doubtless that many refusals or therapy withdrawals are caused by poor or lack of technical initiation, on one hand, and by not taking into account the psychic and ethical aspects of the method, on the other hand.     

Insights into the structural determinants for selective inhibition of nitric oxide synthase isoforms

Selective inhibition of the nitric oxide synthase isoforms (NOS) is a promising approach for the treatment of various disorders. However, given the high active site conservation among all NOS isoforms, the design of selective inhibitors is a challenging task. Analysis of the X-ray crystal structures of the NOS isoforms complexed with known inhibitors most often gives no clues about the structural determinants behind the selective inhibition since the inhibitors share the same binding conformation. Aimed at a better understanding of the structural factors responsible for selective inhibition of NOS isoforms we have performed MD simulations for iNOS, nNOS and eNOS complexed with N^ω-NO₂-L-Arg (1), and with the aminopyridine derivatives 2 and 3. The slightly better selectivity of 1 for nNOS may be assigned to the presence of extra charge–charge interactions due to its “extended” conformation. While the high affinity of 2 for iNOS can be explained by the formation of an iNOS-specific subpocket upon binding, the lack of affinity for eNOS is associated to a conformational change in Glu363. The strong van der Waals and electrostatic interactions between 3 and the active site of nNOS are most likely responsible for its higher affinity for this isoform. Owing to the elongated and narrow binding pocket of iNOS, the correct positioning of 3 over the heme group is difficult, which may account for its lower affinity toward this isoform. Brought together, our results might help to rationalize the design of selective NOS inhibitors.