RESUMEN
Dinoflagellate species of the genera Gambierdiscus and Fukuyoa are known to produce ciguatera poisoning-associated toxic compounds, such as ciguatoxins, or other toxins, such as maitotoxins. However, many species and strains remain poorly characterized in areas where they were recently identified, such as the western Mediterranean Sea. In previous studies carried out by our research group, a G. australes strain from the Balearic Islands (Mediterranean Sea) presenting MTX-like activity was characterized by LC-MS/MS and LC-HRMS detecting 44-methyl gambierone and gambieric acids C and D. However, MTX1, which is typically found in some G. australes strains from the Pacific Ocean, was not detected. Therefore, this study focuses on the identification of the compound responsible for the MTX-like toxicity in this strain. The G. australes strain was characterized not only using LC-MS instruments but also N2a-guided HPLC fractionation. Following this approach, several toxic compounds were identified in three fractions by LC-MS/MS and HRMS. A novel MTX analogue, named MTX5, was identified in the most toxic fraction, and 44-methyl gambierone and gambieric acids C and D contributed to the toxicity observed in other fractions of this strain. Thus, G. australes from the Mediterranean Sea produces MTX5 instead of MTX1 in contrast to some strains of the same species from the Pacific Ocean. No CTX precursors were detected, reinforcing the complexity of the identification of CTXs precursors in these regions.
Asunto(s)
Intoxicación por Ciguatera , Dinoflagelados/química , Toxinas Marinas/química , Oxocinas/química , Animales , Organismos Acuáticos , Mar Mediterráneo , Relación Estructura-ActividadRESUMEN
The recent emergence of ciguatera in the eastern Atlantic, particularly in the Canary Islands (Spain) and Madeira (Portugal) prompted the development and implementation of liquid chromatography tandem-mass spectrometry (LC/MS-MS) methods for the detection of ciguatoxins in fish. The complexity of fish tissue matrices, low concentrations of ciguatoxins in hazardous fish, and the scarcity of ciguatoxin standards present challenging issues for successful implementation of routine ciguatoxin analysis. A laboratory reference material of Caribbean Ciguatoxin-1 (C-CTX1), which was previously confirmed in fish responsible for ciguatera outbreaks in the Canary Islands, was used to assess the toxin's stability under strongly acidic conditions and solvent systems commonly used in LC-MS/MS. It was observed that strongly acidic conditions caused the transformation of C-CTX1 to a C56 methoxy congener, C-CTX1-Me. C-CTX1 was structurally characterised by LC-MS/MS and fragmentation pathways are presented showing the same fragmentation pattern as C-CTX1-Me. These results suggest that the use of strongly acidic conditions during sample pretreatment for C-CTX analysis, might produce significant artefacts, and risks failing to detect the presence of C-CTX1.
Asunto(s)
Ácidos/química , Ciguatoxinas/química , Inocuidad de los Alimentos , Alimentos Marinos/análisis , Animales , Peces , Concentración de Iones de HidrógenoRESUMEN
Compounds similar to maitotoxin (MTX) have been isolated from several laboratory strains of the dinoflagellate Gambierdiscus spp. from the Caribbean. Mass spectral results suggest that these compounds differ from MTX by the loss of one sulfate group and, in some cases, the loss of one methyl group with the addition of one degree of unsaturation. NMR experiments, using approximately 50â¯nmol of one of these compounds, have demonstrated that the 9-sulfo group of MTX is still present, suggesting that these compounds are 40-desulfo congeners of MTX.
Asunto(s)
Dinoflagelados/química , Toxinas Marinas/química , Oxocinas/química , Región del Caribe , Cromatografía Liquida , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Estructura MolecularRESUMEN
The increased emergence of Ciguatera Fish Poisoning in the Canary Islands and Madeira demanded the development of confirmatory methods by liquid chromatography coupled to tandem mass spectrometry to characterize the risk. Efforts were particularly focused on the optimization of sample pretreatment, especially in the sample cleanup step, to efficiently remove matrix interferences as a critical factor to consider in mass spectrometry detection. Two different LC-MS/MS approaches have been used for confirmation purposes, the first one using the sodium adduct as precursor and product ion to allow an increased sensitivity in the detection, whereas additional fragments were also monitored for further confirmation. The optimized conditions above mentioned allowed the confirmation of Caribbean Ciguatoxin-1 as the main responsible for the samples analyzed from these geographical areas, while the presence of a new hydroxyl metabolite of C-CTX1 was also confirmed in one sample analyzed in this study.
Asunto(s)
Ciguatoxinas/análisis , Espectrometría de Masas en Tándem , Animales , Cromatografía Líquida de Alta Presión , Intoxicación por Ciguatera , Ciguatoxinas/aislamiento & purificación , Peces/metabolismo , Límite de Detección , Alimentos Marinos/análisis , Extracción en Fase Sólida , EspañaRESUMEN
The present study investigates whether leuprolide acetate (Lupron) adds to the efficacy of traditional sex offender treatment. A group of sex offenders receiving both Lupron and cognitive behavioral therapy (CBT; n = 25) were compared with a group of sex offenders receiving only CBT (n = 22). Treated subjects were compared with norms available with reference to the Static-99R, as well as compared with a sample of untreated, nonsexual violent offenders (n = 81), to provide baseline data regarding risk of violent recidivism. Results indicated that subjects receiving Lupron were at significantly higher risk of recidivism and significantly more likely to be diagnosed with a paraphilia than subjects receiving only CBT, a priori. Both treated groups of sexual offenders recidivated at substantially lower rates than predicted by the Static-99R. Currently, this study represents the only, long-term outcome study on Lupron administration using officially recorded recidivism as the primary dependent measure.
Asunto(s)
Terapia Cognitivo-Conductual , Criminales , Leuprolida/uso terapéutico , Trastornos Parafílicos/terapia , Reincidencia/prevención & control , Delitos Sexuales , Adulto , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Trastornos Parafílicos/tratamiento farmacológico , Trastornos Parafílicos/psicologíaRESUMEN
Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world. It causes substantial human health, social, and economic impacts. The illness produces a complex array of gastrointestinal, neurological and neuropsychological, and cardiovascular symptoms, which may last days, weeks, or months. This paper is a general review of CFP including the human health effects of exposure to ciguatoxins (CTXs), diagnosis, human pathophysiology of CFP, treatment, detection of CTXs in fish, epidemiology of the illness, global dimensions, prevention, future directions, and recommendations for clinicians and patients. It updates and expands upon the previous review of CFP published by Friedman et al. (2008) and addresses new insights and relevant emerging global themes such as climate and environmental change, international market issues, and socioeconomic impacts of CFP. It also provides a proposed universal case definition for CFP designed to account for the variability in symptom presentation across different geographic regions. Information that is important but unchanged since the previous review has been reiterated. This article is intended for a broad audience, including resource and fishery managers, commercial and recreational fishers, public health officials, medical professionals, and other interested parties.
Asunto(s)
Intoxicación por Ciguatera/epidemiología , Ciguatoxinas/toxicidad , Peces/metabolismo , Alimentos Marinos/envenenamiento , Animales , Brotes de Enfermedades , Humanos , Salud PúblicaRESUMEN
A novel coronavirus (MERS-CoV) related to SARS-CoV recently emerged in the Middle East causing more than 400 deaths with a mortality rate of about 30%, much higher than SARS-CoV. Both viruses target epithelial cells in the respiratory tract, although utilizing different cellular receptors. Because of the sporadic nature of the MERS outbreak and difficulty in collecting randomized, controlled clinical data, the objective of this review was to focus on published in vitro and in vivo drug sensitivity data using both cell lines and available animal models of SARS/MERS CoV infection. Determination of drug activity was based on achievable serum levels in humans relative to in vitro IC50 (50% inhibitory concentration) or EC50 (50% effective concentration) drug concentrations. The most active drugs against SARS/MERS CoV at clinically achievable serum levels were type I interferons and a TLR3 agonist, interferon inducer/activator.
Asunto(s)
Antivirales/administración & dosificación , Infecciones por Coronavirus/tratamiento farmacológico , Factores Inmunológicos/administración & dosificación , Interferones/administración & dosificación , Coronavirus del Síndrome Respiratorio de Oriente Medio/efectos de los fármacos , Mucosa Respiratoria/efectos de los fármacos , Síndrome Respiratorio Agudo Grave/tratamiento farmacológico , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/efectos de los fármacos , Animales , Antivirales/sangre , Línea Celular , Infecciones por Coronavirus/virología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Cálculo de Dosificación de Drogas , Humanos , Factores Inmunológicos/sangre , Interferones/sangre , Pruebas de Sensibilidad Microbiana , Coronavirus del Síndrome Respiratorio de Oriente Medio/patogenicidad , Mucosa Respiratoria/virología , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/patogenicidad , Síndrome Respiratorio Agudo Grave/virologíaRESUMEN
Ciguatoxins are potent neurotoxins with a significant public health impact. Cytotoxicity assays have allowed the most sensitive means of detection of ciguatoxin-like activity without reliance on mouse bioassays and have been invaluable in studying outbreaks. An improvement of these cell-based assays is presented here in which rapid flow cytometric detection of ciguatoxins and saxitoxins is demonstrated using fluorescent voltage sensitive dyes. A depolarization response can be detected directly due to ciguatoxin alone; however, an approximate 1000-fold increase in sensitivity is observed in the presence of veratridine. These results demonstrate that flow cytometric assessment of ciguatoxins is possible at levels approaching the trace detection limits of our earlier cytotoxicity assays, however, with a significant reduction in analysis time. Preliminary results are also presented for detection of brevetoxins and for automation and throughput improvements to a previously described method for detecting saxitoxins in shellfish extracts.
Asunto(s)
Intoxicación por Ciguatera/metabolismo , Ciguatoxinas/química , Citometría de Flujo/métodos , Músculo Esquelético/química , Saxitoxina/química , Canales de Sodio/química , Animales , Automatización , Línea Celular Tumoral , Peces Planos , Análisis de los Alimentos , Músculo Esquelético/metabolismo , NeuroblastomaRESUMEN
Aquatic food accounts for over 40% of global animal food products, and the potential contamination with toxins of algal origin--marine biotoxins--poses a health threat for consumers. The gold standards to assess toxins in aquatic food have traditionally been in vivo methods, i.e., the mouse as well as the rat bioassay. Besides ethical concerns, there is also a need for more reliable test methods because of low inter-species comparability, high intra-species variability, the high number of false positive and negative results as well as questionable extrapolation of quantitative risk to humans. For this reason, a transatlantic group of experts in the field of marine biotoxins was convened from academia and regulatory safety authorities to discuss future approaches to marine biotoxin testing. In this report they provide a background on the toxin classes, on their chemical characterization, the epidemiology, on risk assessment and management, as well as on their assumed mode of action. Most importantly, physiological functional assays such as in vitro bioassays and also analytical techniques, e.g., liquid chromatography coupled mass spectrometry (LC-MS), as substitutes for the rodent bioassay are reviewed. This forms the basis for recommendations on methodologies for hazard monitoring and risk assessment, establishment of causality of intoxications in human cases, a roadmap for research and development of human-relevant functional assays, as well as new approaches for a consumer directed safety concept.
Asunto(s)
Toxinas Marinas/toxicidad , Pruebas de Toxicidad/métodos , Alternativas a las Pruebas en Animales/métodos , Animales , Contaminación de Alimentos , Abastecimiento de Alimentos , Humanos , Toxinas Marinas/química , Medición de RiesgoRESUMEN
Following the 2010 Deepwater Horizon oil spill, petroleum-related compounds and chemical dispersants were detected in the waters of the Gulf of Mexico. As a result, there was concern about the risk to human health through consumption of contaminated seafood in the region. Federal and Gulf Coast State agencies worked together on a sampling plan and analytical protocols to determine whether seafood was safe to eat and acceptable for sale in the marketplace. Sensory and chemical methods were used to measure polycyclic aromatic hydrocarbons (PAHs) and dispersant in >8,000 seafood specimens collected in federal waters of the Gulf. Overall, individual PAHs and the dispersant component dioctyl sodium sulfosuccinate were found in low concentrations or below the limits of quantitation. When detected, the concentrations were at least two orders of magnitude lower than the level of concern for human health risk. Once an area closed to fishing was free of visibly floating oil and all sensory and chemical results for the seafood species within an area met the criteria for reopening, that area was eligible to be reopened. On April 19, 2011 the area around the wellhead was the last area in federal waters to be reopened nearly 1 y after the spill began. However, as of November 9, 2011, some state waters off the Louisiana coast (Barataria Bay and the Delta region) remain closed to fishing.
Asunto(s)
Inocuidad de los Alimentos , Contaminación por Petróleo/efectos adversos , Alimentos Marinos/normas , Animales , Monitoreo del Ambiente , Explotaciones Pesqueras/normas , Humanos , Louisiana , Petróleo/análisis , Petróleo/toxicidad , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Medición de Riesgo , Alimentos Marinos/análisis , Alimentos Marinos/toxicidad , Estados Unidos , United States Food and Drug Administration , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/normas , Contaminantes Químicos del Agua/toxicidadRESUMEN
BACKGROUND: Although ciguatera fish poisoning (CFP) is the most common seafood intoxication worldwide, its burden has been difficult to establish because there are no biomarkers to diagnose human exposure. OBJECTIVE: We explored the incidence of CFP, percentage of CFP case-patients with laboratory-confirmed ciguatoxic meal remnants, cost of CFP illness, and potential risk factors for CFP. METHODS: During 2005 and again during 2006, we conducted a census of all occupied households on the island of Culebra, Puerto Rico, where locally caught fish are a staple food. We defined CFP case-patients as persons with gastrointestinal symptoms (abdominal pain, vomiting, diarrhea, or nausea) and neurological symptoms (extremity paresthesia, arthralgia, myalgia, malaise, pruritus, headache, dizziness, metallic taste, visual disturbance, circumoral paresthesia, temperature reversal, or toothache) or systemic symptoms (e.g., bradycardia) within 72 hr of eating fish during the previous year. Participants were asked to save fish remnants eaten by case-patients for ciguatoxin analysis at the Food and Drug Administration laboratory in Dauphin Island, Alabama (USA). RESULTS: We surveyed 340 households during 2005 and 335 households during 2006. The estimated annual incidence of possible CFP was 4.0 per 1,000 person-years, and that of probable CFP was 7.5 per 1,000 person-years. One of three fish samples submitted by probable case-patients was positive for ciguatoxins. None of the case-patients required respiratory support. Households that typically consumed barracuda were more likely to report CFP (p = 0.02). CONCLUSIONS: Our estimates, which are consistent with previous studies using similar case findings, contribute to the overall information available to support public health decision making about CFP prevention.
Asunto(s)
Intoxicación por Ciguatera/epidemiología , Perciformes/metabolismo , Alimentos Marinos/envenenamiento , Adulto , Animales , Intoxicación por Ciguatera/diagnóstico , Intoxicación por Ciguatera/economía , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Puerto Rico/epidemiología , Factores de Riesgo , Estaciones del Año , Encuestas y Cuestionarios , Adulto JovenRESUMEN
The penile response profiles of homosexual and heterosexual pedophiles, hebephiles, and teleiophiles to laboratory stimuli depicting male and female children and adults may be conceptualized as a series of overlapping stimulus generalization gradients. This study used such profile data to compare two models of alloerotic responding (sexual responding to other people) in men. The first model was based on the notion that men respond to a potential sexual object as a compound stimulus made up of an age component and a gender component. The second model was based on the notion that men respond to a potential sexual object as a gestalt, which they evaluate in terms of global similarity to other potential sexual objects. The analytic strategy was to compare the accuracy of these models in predicting a man's penile response to each of his less arousing (nonpreferred) stimulus categories from his response to his most arousing (preferred) stimulus category. Both models based their predictions on the degree of dissimilarity between the preferred stimulus category and a given nonpreferred stimulus category, but each model used its own measure of dissimilarity. According to the first model ("summation model"), penile response should vary inversely as the sum of stimulus differences on separate dimensions of age and gender. According to the second model ("bipolar model"), penile response should vary inversely as the distance between stimulus categories on a single, bipolar dimension of morphological similarity-a dimension on which children are located near the middle, and adult men and women are located at opposite ends. The subjects were 2,278 male patients referred to a specialty clinic for phallometric assessment of their erotic preferences. Comparisons of goodness of fit to the observed data favored the unidimensional bipolar model.
Asunto(s)
Literatura Erótica , Hombres/psicología , Modelos Psicológicos , Erección Peniana/fisiología , Pene/irrigación sanguínea , Sexualidad/fisiología , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Erección Peniana/psicología , Sexualidad/psicologíaRESUMEN
Ciguatera fish poisoning (CFP) is endemic in certain tropical and subtropical regions of the world. CFP had not been described on the West Africa Coast until a 2004 outbreak in the Canary Islands. In 2008-2009, two additional outbreaks of ciguatera occurred. Individuals afflicted had consumed lesser amberjack (Seriola rivoliana) captured from nearby waters. Caribbean ciguatoxin-1 (C-CTX-1) was confirmed in fish samples by LC-MS/MS. Ciguatoxic fish in this region may pose a new health risk for the seafood consumer.
Asunto(s)
Intoxicación por Ciguatera/epidemiología , Brotes de Enfermedades , Alimentos Marinos/envenenamiento , Animales , Ciguatoxinas/química , Ciguatoxinas/metabolismo , Peces/metabolismo , Humanos , Medición de Riesgo , España/epidemiologíaRESUMEN
Phallometric assessments of single-victim sexual offenders against children have suggested that only about 50% of these men are more attracted to children than they are to adults. This has raised the question of what motivates the other 50% of men to approach young girls for sex. Freund et al. showed that gynephilic men (i.e., men preferentially attracted to adult women) evidenced greater arousal to images of prepubescent girls than to images of males of any age or to nonerotic images, arguing that gynephilic men may approach prepubescent girls as a "surrogate" for their preferred erotic targets (i.e., adult women). One might argue that these phallometric results are artifactual, given that they were obtained in a time period during which images of nudity were far less common than they are today (thus any female nudity might have elicited arousal). To address this issue, the authors examined the sexual arousal patterns of 214 contemporary men who, based on self-report, offense history, and phallometric responses, were purely gynephilic. Results showed the "classical control profile": the greatest arousal to adult women, systematically decreasing arousal as the female stimuli became younger, and essentially no arousal to any age categories of males or to neutral (nonerotic) stimuli. Arousal to both pubescent and prepubescent girls was significantly greater than to neutral stimuli (p < .001 for both). Thus, Freund et al.'s results still appear to be valid, and the explanation for child molesting that they suggest still seems to be feasible.
Asunto(s)
Abuso Sexual Infantil/diagnóstico , Hombres , Pedofilia/diagnóstico , Erección Peniana/fisiología , Pletismografía/métodos , Adulto , Nivel de Alerta/fisiología , Recursos Audiovisuales , Niño , Abuso Sexual Infantil/clasificación , Femenino , Humanos , Masculino , Hombres/psicología , Persona de Mediana Edad , Ontario , Pedofilia/clasificación , Pene/fisiología , Psicometría , Análisis de Regresión , Delitos Sexuales , Grabación en Cinta , Adulto JovenRESUMEN
Phallometric testing is widely considered the best psychophysiological procedure for assessing erotic preferences in men. Researchers have differed, however, on the necessity of setting some minimum criterion of penile response for ascertaining the interpretability of a phallometric test result. Proponents of a minimum criterion have generally based their view on the intuitive notion that "more is better" rather than any formal demonstration of this. The present study was conducted to investigate whether there is any empirical evidence for this intuitive notion, by examining the relation between magnitude of penile response and the agreement in diagnoses obtained in two test sessions using different laboratory stimuli. The results showed that examinees with inconsistent diagnoses responded less on both tests and that examinees with inconsistent diagnoses responded less on the second test after controlling for their response on the first test. Results also indicated that at response levels less than 1 cm(3), diagnostic consistency was no better than chance, supporting the establishment of a minimum response level criterion.
Asunto(s)
Hombres , Pedofilia/diagnóstico , Erección Peniana , Pletismografía/métodos , Delitos Sexuales/psicología , Adulto , Recursos Audiovisuales , Psiquiatría Forense/métodos , Humanos , Clasificación Internacional de Enfermedades , Masculino , Hombres/psicología , Persona de Mediana Edad , Ontario , Pedofilia/clasificación , Pedofilia/psicología , Erección Peniana/fisiología , Erección Peniana/psicología , Pruebas Psicológicas , Psicometría , Reproducibilidad de los ResultadosRESUMEN
Ciguatera fish poisoning is a seafood-borne illness caused by consumption of fish that have accumulated lipid-soluble ciguatoxins. In the United States, ciguatera is responsible for the highest reported incidence of food-borne illness outbreaks attributed to finfish, and it is reported to hold this distinction globally. Ciguatoxins traverse the marine food web from primary producers, Gambierdiscus spp., to commonly consumed fish in tropical and subtropical regions of the world. Ciguatoxins comprise 12 known congeners among Caribbean and tropical Atlantic fish and 29 reported congeners among Pacific fish. Expanding trade in fisheries from ciguatera-endemic regions contributes to wider distribution and increasing frequency of disease among seafood consumers in non-endemic regions. Ciguatoxins produce a complex array of gastrointestinal, neurological and cardiological symptoms. Treatment options are very limited and supportive in nature. Information derived from the study of ciguatera outbreaks has improved clinical recognition, confirmation, and timely treatment. Such studies are equally important for the differentiation of ciguatoxin profiles in fish from one region to the next, the determination of toxicity thresholds in humans, and the formulation of safety limits. Analytical information from case and outbreak investigations was used to derive Pacific and Caribbean ciguatoxin threshold contamination rates for adverse effects in seafood consumers. To these threshold estimates 10-fold safety factors were applied to address individual human risk factors; uncertainty in the amount of fish consumed; and analytical accuracy. The studies may serve as the basis for industry and consumer advisory levels of 0.10ppb C-CTX-1 equivalent toxicity in fish from the tropical Atlantic, Gulf of Mexico, Caribbean, and 0.01ppb P-CTX-1 equivalent toxicity in fish from Pacific regions.
Asunto(s)
Intoxicación por Ciguatera/etiología , Seguridad de Productos para el Consumidor , Medicina Preventiva , Alimentos Marinos , Animales , Intoxicación por Ciguatera/fisiopatología , Intoxicación por Ciguatera/terapia , Ciguatoxinas/análisis , Ciguatoxinas/farmacología , Dinoflagelados , Brotes de Enfermedades/prevención & control , Relación Dosis-Respuesta a Droga , Monitoreo del Ambiente , Peces Venenosos , Cadena Alimentaria , Humanos , Industrias , Medición de RiesgoRESUMEN
Herein, we describe advancements in monitoring of brevetoxins in molluscan shellfish, with respect to exposure management and control of neurotoxic shellfish poisoning (NSP). Current knowledge of the fate of brevetoxins in molluscan shellfish, and the toxic potency of brevetoxin metabolites, is presented. We review rapid assays for measuring composite brevetoxins, and methodology for measuring constituent brevetoxins, in contaminated shellfish. The applicability of in vitro methods for estimating brevetoxin burden and composite toxicity in shellfish is assessed. Specific and measurable biomarkers of brevetoxin exposure and toxicity in shellfish, and of human intoxication, are described. Their utility in regulatory monitoring of toxic shellfish and in clinical diagnosis of NSP is evaluated.
Asunto(s)
Bivalvos/química , Dinoflagelados/química , Monitoreo del Ambiente/métodos , Toxinas Marinas , Neurotoxinas , Oxocinas , Intoxicación por Mariscos , Animales , Biomarcadores/análisis , Humanos , Toxinas Marinas/análisis , Toxinas Marinas/toxicidad , Neurotoxinas/análisis , Neurotoxinas/toxicidad , Oxocinas/análisis , Oxocinas/toxicidad , Mariscos/análisis , Pruebas de ToxicidadRESUMEN
There are at least two different criteria for assessing pedophilia in men: absolute ascertainment (their sexual interest in children is intense) and relative ascertainment (their sexual interest in children is greater than their interest in adults). The American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 3rd edition (DSM-III) used relative ascertainment in its diagnostic criteria for pedophilia; this was abandoned and replaced by absolute ascertainment in the DSM-III-R and all subsequent editions. The present study was conducted to demonstrate the continuing need for relative ascertainment, particularly in the laboratory assessment of pedophilia. A total of 402 heterosexual men were selected from a database of patients referred to a specialty clinic. These had undergone phallometric testing, a psychophysiological procedure in which their penile blood volume was monitored while they were presented with a standardized set of laboratory stimuli depicting male and female children, pubescents, and adults.The 130 men selected for the Teleiophilic Profile group responded substantially to prepubescent girls but even more to adult women; the 272 men selected for the Pedophilic Profile group responded weakly to prepubescent girls but even less to adult women. In terms of absolute magnitude, every patient in the Pedophilic Profile group had a lesser penile response to prepubescent girls than every patient in the Teleiophilic Profile group. Nevertheless, the Pedophilic Profile group had a significantly greater number of known sexual offenses against prepubescent girls, indicating that they contained a higher proportion of true pedophiles. These results dramatically demonstrate the utility-or perhaps necessity-of relative ascertainment in the laboratory assessment of erotic age-preference.