22 research outputs found
Postorgasmic Illness Syndrome (POIS) in 45 Dutch Caucasian Males: Clinical Characteristics and Evidence for an Immunogenic Pathogenesis (Part 1)
No full textIntroduction. Postorgasmic illness syndrome (POIS) is a combination of local allergic symptoms and transient flu-like illness. In this study, the investigators propose five preliminary criteria to establish the diagnosis. Aim. To describe the clinical details in 45 males being suspected of having POIS and to test an immunogenic hypothesis as the underlying mechanism of their presentations. Methods. Forty-five males were studied according to standardized protocol, including neuropsychiatric and medical sexological evaluations; their complaints were categorized using their own words, and their self-perceived intravaginal ejaculation latency time (IELT). Skin-prick testing with autologous diluted semen in 33 men were also performed. Main Outcome Measures. Clinical features of POIS including self-perceived IELTs and the results of skin-prick testing with autologous diluted seminal fluid. Results. Of the 45 included men, 33 subjects consented with skin-prick testing. Of them, 29 (88%) men had a positive skin-prick test with their own (autologous) semen, and four had a negative test. In 87% of men, POIS symptoms started within 30 minutes after ejaculation. Complaints of POIS were categorized in seven clusters of symptoms, e.g., general, flu-like, head, eyes, nose, throat, and muscles. Local allergic reactions of eyes and nose were reported in 44% and 33% of subjects, a flu-like syndrome in 78% of subjects, exhaustion and concentration difficulties in 80% and 87% of subjects. Of all subjects, 58% had an atopic constitution. Lifelong premature ejaculation, defined as self-perceived IELT <1 minute, was reported in 25 (56%) of subjects. Conclusions. The combination of allergic and systemic flu-like reactions post-ejaculation together with a positive skin-prick test in the majority of males underscores the hypothesis of an "immunogenic" etiology of POIS, e.g., that POIS is caused by Type-1 and Type-IV allergy to the males' own semen, as soon it is triggered by ejaculation. Waldinger MD, Meinardi MMHM, Zwinderman AH, and Schweitzer DH. Postorgasmic illness syndrome (POIS) in 45 Dutch Caucasian males: Clinical characteristics and evidence for an immunogenic pathogenesis (Part 1). J Sex Med 2011;8:1164-117
Reproducibility of sublingual microcirculation parameters obtained from sidestream darkfield imaging
No full textBackgroundChanges in the microcirculation may be used as a surrogate outcome in studies on cardiovascular disease. We assessed the reliability characteristics of the sublingual microcirculation parameters Vascular Density (VD), Red Blood Cell Filling (RBCF), and Perfused Boundary Region (PBR) as obtained by sidestream darkfield imaging.MethodsFor each of the three parameters, the variance components of measurement, the Intraclass Correlation Coefficient (ICC), the Standard Error of Measurement, and the limits of agreement were estimated for the intra-rater setting (N = 50) and the inter-rater setting (N = 48). Subsequently, as a proof of concept, the reliability measures were used for a power analysis to design studies to evaluate the effect of acute stimuli–i.e. having a meal (N = 50) and cigarette smoking (N = 21) on the three parameters.ResultsReproducibility was poor for all three parameters. The intra-rater ICC for 2 measurements was 0.28 (95% CI: 0.04, 0.53) for the VD, 0.51 (95% CI: 0.27, 0.69) for the RBCF, and 0.33 (95% CI: 0.08–0.56) for the PBR. The standard errors of measurement and the limits of agreement for all three parameters were larger than most statistically significant intra-individual or inter-individual differences reported in previous studies. The proofs of concept showed that sample sizes in excess of 600 subjects are necessary to reach statistical significance for the observed effects of having a meal or smoking on VD and PBR.ConclusionsThe reliability of the three sublingual microcirculation parameters in their current form appears to be low and a large sample size is advisable for their use in conditions similar to those we describe.</div
Statistical models for quantifying diagnostic accuracy with multiple lesions per patient
No full textWe propose random-effects models to summarize and quantify the accuracy of the diagnosis of multiple lesions on a single image without assuming independence between lesions. The number of false-positive lesions was assumed to be distributed as a Poisson mixture, and the proportion of true-positive lesions was assumed to be distributed as a binomial mixture. We considered univariate and bivariate, both parametric and nonparametric mixture models. We applied our tools to simulated data and data of a study assessing diagnostic accuracy of virtual colonography with computed tomography in 200 patients suspected of having one or more polyp
The majority of men with lifelong premature ejaculation prefer daily drug treatment: an observation study in a consecutive group of Dutch men
No full textINTRODUCTION: Whether men with lifelong premature ejaculation (PE) prefer on-demand drug treatment to delay ejaculation time to daily drug treatment, has never been studied as a separate study question. AIM: To study how men with lifelong PE feel about the use of serotonergic antidepressants, and which option they would prefer for themselves: either a daily drug, a drug to be used on demand, or a topical anesthetic cream to be applied on demand. MAIN OUTCOME MEASURES: Treatment preference was determined by questionnaire. METHODS: An observational questionnaire survey in a clinical sample. Preferences of different treatment strategies were queried before and after standard efficacy and safety information. RESULTS: A consecutive group of 88 men with lifelong PE who decided for themselves to be seen for rapid ejaculation was studied. The age was 37 +/- 11 years (mean +/- SD), range 18-64 years. None of these men was ever treated for PE and 21% used medication that did not affect sexual performance. Of them, 71 (81%) preferred a drug for daily use, 14 (16%) a drug on demand, while three men preferred topical anesthetic cream. Those men who initially preferred daily treatment did not change their view after standard information about efficacy and side effects, while 9 of 17 men who initially preferred on-demand drug treatment had switched their preferences to daily oral drug usage. Around 60% of men did not care about the nature of the drug, i.e., an antidepressant. The most frequently reported argument to prefer daily drug treatment was that this strategy would have the least effects toward the spontaneity of having sex. CONCLUSION: As opposed to agents that must be taken 4-6 hours prior to coitus and with the methods used here, this group of Dutch men with lifelong PE favor uninterrupted daily drug treatment to delay ejaculation mainly because daily treatment guarantees no interference with the spontaneity of having se
Use of plasma metabolomics to analyze phenotype-genotype relationships in young hypercholesterolemic females
No full textHypercholesterolemia is characterized by high plasma LDL cholesterol and often caused by genetic mutations in LDL receptor (LDLR), APOB, or proprotein convertase subtilisin/kexin type 9 (PCSK9). However, a substantial proportion of hypercholesterolemic subjects do not have any mutations in these canonical genes, leaving the underlying pathobiology to be determined. In this study, we investigated to determine whether combining plasma metabolomics with genetic information increases insight in the biology of hypercholesterolemia. For this proof of concept study, we combined plasma metabolites from 119 hypercholesterolemic females with genetic information on the LDL canonical genes. Using hierarchical clustering, we identified four subtypes of hypercholesterolemia, which could be distinguished along two axes represented by triglyceride and large LDL particle concentration. Subjects with mutations in LDLR or APOB preferentially clustered together, suggesting that patients with defects in the LDLR pathway show a distinctive metabolomics profile. In conclusion, we show the potential of using metabolomics to segregate hypercholesterolemic subjects into different clusters, which may help in targeting genetic analysis
A joint latent class changepoint model to improve the prediction of time to graft failure
No full textThe reciprocal of serum creatinine concentration, RC, is often used as a biomarker to monitor renal function. It has been observed that RC trajectories remain relatively stable after transplantation until a certain moment, when an irreversible decrease in the RC levels occurs. This decreasing trend commonly precedes failure of a graft. Two subsets of individuals can be distinguished according to their RC trajectories: a subset of individuals having stable RC levels and a subset of individuals who present an irrevocable decrease in their RC levels. To describe such data, the paper proposes a joint latent class model for longitudinal and survival data with two latent classes. RC trajectories within latent class one are modelled by an intercept-only random-effects model and RC trajectories within latent class two are modelled by a segmented random changepoint model. A Bayesian approach is used to fit this joint model to data from patients who had their first kidney transplantation in the Leiden University Medical Center between 1983 and 2002. The resulting model describes the kidney transplantation data very well and provides better predictions of the time to failure than other joint and survival models. Copyright 2008 Royal Statistical Society.
A joint latent class changepoint model to improve the prediction of time to graft failure
No full textThe reciprocal of serum creatinine concentration, RC, is often used as a biomarker to monitor renal function. It has been observed that RC trajectories remain relatively stable after transplantation until a certain moment, when an irreversible decrease in the RC levels occurs. This decreasing trend commonly precedes failure of a graft. Two subsets of individuals can be distinguished according to their RC trajectories: a subset of individuals having stable RC levels and a subset of individuals who present an irrevocable decrease in their RC levels. To describe such data, the paper proposes a joint latent class model for longitudinal and survival data with two latent classes. RC trajectories within latent class one are modelled by an intercept-only random-effects model and RC trajectories within latent class two are modelled by a segmented random changepoint model. A Bayesian approach is used to fit this joint model to data from patients who had their first kidney transplantation in the Leiden University Medical Center between 1983 and 2002. The resulting model describes the kidney transplantation data very well and provides better predictions of the time to failure than other joint and survival model
Modulation of Lipoprotein(a) Atherogenicity by High Density Lipoprotein Cholesterol Levels in Middle-Aged Men With Symptomatic Coronary Artery Disease and Normal to Moderately Elevated Serum Cholesterol fn1fn1This study was supported by Bristol-Myers Squibb Co., Princeton, New Jersey (REGRESS main study) and by Grant 94.032 from the Dutch Heart Foundation, Den Haag, The Netherlands [lipoprotein(a) substudy].
No full textAbstractObjectives. This study sought to examine whether lipoprotein(a) levels predict coronary artery lumen changes in patients with symptomatic coronary artery disease (CAD) and normal to moderate hypercholesterolemia.Background. Recent conflicting reports have confirmed or refuted the association of lipoprotein(a) with clinical events or angiographically verified disease progression.Methods. The association between serum lipoprotein(a) and changes in coronary artery lumen was studied in 704 men entered into the Regression Growth Evaluation Statin Study (REGRESS), a double-blind, placebo-controlled, quantitative angiographic study that assessed the effect of 2 years of pravastatin treatment. The primary end points were changes in average mean segment diameter (MSD) and average minimal obstruction diameter (MOD). Pavastatin- and placebo-treated patients were classified as having progressing, regressing or stable CAD, and median lipoprotein(a) concentrations were compared. Bivariate and multivariate regression analyses were performed in the overall patient group and in high risk subgroups.Results. Pravastatin treatment did not affect serum apolipoprotein(a) levels. Median in-trial (sampled at 24 months) apolipoprotein(a) levels for regressing, stable and progressing CAD were, respectively, 130, 162 and 251 U/liter in placebo-treated patients and 143, 224 and 306 U/liter in pravastatin-treated patients. Predictors of MSD and MOD changes were baseline MSD and MOD, in-trial apolipoprotein(a), in-trial high density lipoprotein (HDL) cholesterol and baseline use of long-acting nitrates. The multivariate models predicted 14% of MSD changes and 12% of MOD changes; apolipoprotein(a) predicted only 2.6% and 4.8%, respectively. However, in patients with in-trial HDL cholesterol levels <0.7 mmol/liter, apolipoprotein(a) predicted up to 37% of the arteriographic changes.Conclusions. Serum lipoprotein(a) levels predict coronary artery lumen changes in normal to moderately hypercholesterolemic white men with CAD; its atherogenicity is marked in the presence of concomitant hypoalphalipoproteinemia
