Biomedical subjects

Ian Eardley

Publications and source records attributed to Ian Eardley.

25 records · Page 2Linked to original sources

PubMed2004

Pharmacotherapy for erectile dysfunction.

INTRODUCTION: Advances in understanding of the biochemistry and physiology of penile erection have led to breakthroughs in pharmacotherapy of erectile dysfunction. AIM: To provide recommendations/guidelines concerning state-of-the-art knowledge for the putative molecular and cellular mechanisms of action of centrally and peripherally acting drugs currently utilized in pharmacotherapy of erectile dysfunction. METHODS: An international consultation in collaboration with the major urology and sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various male and female sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five continents developed in a process over a two-year period. Concerning the Pharmacotherapy for Erectile Dysfunction Committee there were 25 experts from 10 countries. MAIN OUTCOME MEASURE: Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation and debate. RESULTS: Selective and potent oral PDE5 inhibitors have significantly more affinity than cGMP and form broader molecular interactions with multiple amino acids, thereby blocking access to cGMP in the catalytic sites of the PDE5 enzyme. PDE5 inhibitors, which vary as to biochemical potency, selectivity and pharmacokinetics, lead to cGMP elevation and relaxation facilitation of penile corpus cavernosum smooth muscle cells following sexual stimulation. Various centrally acting drugs influence sexual behaviour. In particular, the dopaminergic substance apomorphine is a central enhancer that acts in the paraventricular nucleus of the hypothalamus as a dopamine (D2) receptor agonist, induces and increases penile erection responses via disinhibition, following sexual stimulation. CONCLUSIONS: There is a need for more research in the pharmacotherapeutic development of central and peripheral agents for safe and effective erectile dysfunction treatment.

Apomorphine↗

PubMed2004

The multinational Men's Attitudes to Life Events and Sexuality (MALES) Study Phase II: understanding PDE5 inhibitor treatment seeking patterns, among men with erectile dysfunction.

OBJECTIVE: The aim of Phase II of the Men's Attitudes to Life Events and Sexuality (MALES) Study is to explore PDE5 inhibitor treatment seeking among men with erectile dysfunction (ED). METHODS: Phase II of the MALES study involved 2,912 men, aged 20-75 years, from 8 countries (U.S., U.K., Germany, France, Italy, Spain, Mexico, and Brazil), who reported ED. Participants were recruited from the MALES Phase I sample [1] and via booster methods (e.g., physician referral, street interception), and completed self-report questionnaires concerning the characteristics of their ED, their efforts to seek PDE5 inhibitor treatment for their sexual dysfunction, and attitudinal and referent influences that potentially affect treatment-seeking. Statistical analyses focus on identification of correlates of PDE5 inhibitor treatment seeking. RESULTS: PDE5 inhibitor utilization is strongly associated with ED sufferers' assessment of the severity of their sexual dysfunction, with their belief that medication for ED is dangerous, and with their perceptions of whether physicians, other professionals, and spouses or family members are supportive of their seeking treatment. ED sufferers who evaluate their sexual dysfunction as severe, who believe that medication for ED is not dangerous, and who perceive support for treatment seeking from referent others, are more likely to utilize PDE5 inhibitor treatment. CONCLUSION: Findings indicate that perceived ED severity, beliefs about ED medication, and referent influences are strongly correlated with utilization of PDE5 inhibitor therapy. These findings aid our understanding of factors that may incline men with ED to seek-or to avoid-PDE5 inhibitor therapy for their sexual dysfunction, and provide a basis for clinical and educational interventions to assist men with ED to seek appropriate treatment.

3',5'-Cyclic-GMP Phosphodiesterases↗

PubMed2004

The multinational Men's Attitudes to Life Events and Sexuality (MALES) study: I. Prevalence of erectile dysfunction and related health concerns in the general population.

OBJECTIVE: The aims of the Men's Attitudes to Life Events and Sexuality (MALES) study were to identify prevalence of erectile dysfunction (ED) and related health issues in the general male population in Europe, North and South America, and to examine the attitudes and behavior of men in relation to these health issues. RESEARCH DESIGN AND METHODS: Phase I of the MALES study involved 27839 men aged 20-75 years who were interviewed in eight countries (United States, United Kingdom, Germany,France, Italy, Spain, Mexico, and Brazil) using a standardized questionnaire. Phase II of the MALES study involved 2912 men who were recruited from the sub-sample of Phase I MALES participants who reported ED together with additional men with ED recruited from other sources. MAIN OUTCOME MEASURE: Prevalence of ED and associated attitudes. RESULTS: The overall prevalence of ED in the MALES sample was 16%. ED prevalence varied markedly by country, however, from a high of 22%of men in the US reporting ED to a low of 10% in Spain. The prevalence of self-reported ED increased with increasing age. Men with co-morbid medical conditions and risk factors, including cardiovascular disease, hypertension, dyslipidemia,and depression all reported higher prevalence of ED. Men with ED also reported increased prevalence rates of these co-morbid conditions. MALES Phase II data indicated that among men who reported ED, 58% had actively sought medical attention for their condition; however, only 16% of men with ED were currently being treated with oral PDE-5 therapy. CONCLUSIONS: The MALES study confirms the high prevalence rates of ED and its association with co-morbid medical conditions, such as diabetes and depression, reported in other large-scale, epidemiological studies. Despite the advent of oral phosphodiesterase inhibitors, only 58% of ED sufferers consult a physician about their problem, and only 16% of men with self-reported ED maintain their use of oral therapy.

Adult↗

PubMed2003

Proteomic changes in renal cancer and co-ordinate demonstration of both the glycolytic and mitochondrial aspects of the Warburg effect.

Renal cell carcinoma (RCC) is the tenth most common cancer although the incidence is increasing. The main clinical problems stem from the relatively late presentation of many patients due to the often asymptomatic nature of the illness, and the relative insensitivity of metastatic disease to conventional chemotherapy and radiotherapy. Despite increasing knowledge of some of the genetic changes underlying sporadic renal cancer such as those involving the Von Hippel Lindau (VHL) gene, many of the underlying pathophysiological changes are ill-defined and there remains a need for the identification of disease markers for use in diagnosis and prognosis or as potential therapeutic targets. This study has used a proteomic approach, based on two-dimensional gel electrophoresis and mass spectrometry, to compare the protein profiles of conventional RCC tissue with patient-matched normal kidney cortex. Sequencing of 32 protein spots with significantly increased expression in RCC samples (>/= 4/6 patients) and 41 proteins whose levels decreased (6/6 patients) confirmed several previously known RCC-associated changes such as increases in Mn-superoxide dismutase, lactate dehydrogenase-A, aldolase A and C, pyruvate kinase M2, and thymidine phosphorylase. Additionally, several previously unknown changes were identified, including increased expression of three members of the annexin family and increased levels of the actin depolymerisation factor cofilin. The Warburg effect was also demonstrated with the identification of increases in proteins involved in the majority of steps in the glycolytic pathway and decreases in the gluconeogenic reactions, together with a parallel decrease in several mitochondrial enzymes. A number of the alterations seen were further confirmed in additional samples by immunohistochemistry, Western blotting, and laser capture microdissection.

Blotting, Western↗

PubMed2002

A 4-year update on the safety of sildenafil citrate (Viagra).

Clinical studies have demonstrated that sildenafil citrate (Viagra) is an effective and well-tolerated oral treatment for erectile dysfunction. Despite its established safety profile, concern about its cardiovascular safety persists among some physicians and the general public. This concern has stemmed primarily from sporadic reports of adverse events published in the literature and sensationalized by the media. However, the only absolute contraindication for sildenafil is concurrent use of nitrates. Because sildenafil has been on the market for 4 years and under clinical investigation for even longer, we can now evaluate its long-term safety in men who have been taking the drug for several years. We review this issue from 3 perspectives. First, we reassess the overall safety profile of sildenafil by reviewing the initial controlled clinical trials and open-label studies. We present new data from patients who have been exposed to sildenafil for up to 4.5 years. We also evaluate the results from independent postmarketing studies. Second, we review the cardiovascular-specific results from the clinical trials, long-term extension, and postmarketing studies. Lastly, we review the specific effects on the visual system based on findings from studies conducted during drug development and post marketing.

Cardiovascular System↗

PubMed2002

Onset and duration of action of sildenafil for the treatment of erectile dysfunction.

AIMS: To determine the onset and duration of action of sildenafil in patients with erectile dysfunction (ED). METHODS: Two randomised, double-blind, placebo-controlled, two-way crossover studies were conducted in men with ED of no known organic cause. Study I: The time to onset of erections after sildenafil (50 mg) or placebo dosing following visual sexual stimulation (VSS) was assessed in 17 patients. Patients not achieving >60% penile rigidity by 70 min postdose as measured by a RigiScan(R) monitoring device were assigned an onset time of 70 min. Study II: The duration of grade 3 (hard enough for penetration) and grade 4 (fully hard) erections, determined by self-assessment during 60 min of VSS starting 2 and 4 h after sildenafil (100 mg) or placebo dosing, was measured in 16 patients. RESULTS: Study I: The median time (range) to onset of erections was 27 min (in a range of 12--70) after receiving sildenafil 50 mg. In the sildenafil group, 71% of patients experienced onset of erections within 30 min of dosing, and 82% responded within 45 min. Of the patients who achieved >60% penile rigidity after sildenafil, 86% had done so by 30 min after dosing. Study II: When VSS began 2 h postdose, the median duration of grade 3 or 4 erections was 19.5 min (0--55) for sildenafil vs 0 min (0--23) for placebo. When VSS began 4 h postdose, the median duration was 5 min (0--45) for sildenafil compared with 0 min for placebo (0--27). CONCLUSIONS: Sildenafil is an effective oral treatment for ED that produces a penetrative erection as early as 12 min and for most patients, within 30 min after dosing, and a duration of action lasting at least 4 h.

Adult↗

PubMed2002

Imaging for erectile dysfunction.

Radiological imaging in the field of erectile dysfunction has diminished in importance over the past 5 years with the advent of new therapies. However, in selected cases, Doppler scanning continues to have a role, and current research is aimed at optimizing the results of the tests. In addition, the new techniques of functional magnetic resonance imaging and positron emission tomography scanning are beginning to offer new insights into the central mechanisms which control erections.

Humans↗