RESUMEN
Designing proper frontend electronics is critical in the development of highly sophisticated electrode systems. Multielectrode arrays for measuring electrical signals or impedance require multichannel readout systems. Even more challenging is the differential or ratiometric configuration with simultaneous assessment of measurement and reference channels. In this work, an eight-channel frontend was developed for contacting a 2×8 electrode array (8 measurement and 8 reference electrodes) with a large common electrode to the impedance gain-phase analyzer Solartron 1260 (S-1260). Using the three independent and truly parallel monitor channels of the S-1260, impedance of trapped cells and reference material was measured at the same time, thereby considerably increasing the performance of the device. The frontend electronics buffers the generator output and applies a potentiostatic signal to the common electrode of the chip. The applied voltage is monitored using the current monitor of the S-1260 via voltage/current conversion. The frontend monitors the current through the electrodes and converts it to a voltage fed into the voltage monitors of the S-1260. For assessment of the 8 electrode pairs featured by the chip, a relay-based multiplexer was implemented. Extensive characterization and calibration of the frontend were carried out in a frequency range between 100 Hz and 1 MHz. Investigating the influence of the multiplexer and the frontend electronics, direct measurement with and without frontend was compared. Although differences were evident, they have been negligible below one per cent. The significance of measurement using the complex S-1260-frontend-electrode was tested using Kohlrausch's law. The impedance of an electrolytic dilution series was measured and compared to the theoretical values. The coincidence of measured values and theoretical prediction serves as an indicator for electrode sensitivity to cell behavior. Monitoring of cell behavior on the microelectrode surface will be shown as an example.
RESUMEN
The pathogenesis of post-traumatic stress disorder (PTSD) is incompletely understood. We hypothesize that disruptions in mother-child relations may be a key contributor to development of PTSD. A normal and healthy separation-individuation process requires adaptations of self- and interactive contingency in both the mother and her child, especially in early childhood development. Anxious mothers are prone to overprotection, which may hinder the individuation process in their children. We examined long-term stress hormones and other stress markers in subjects three generations removed from the Holocaust, to assess the long-term consequences of inherited behavioral and physiological responses to prior stress and trauma. Jewish subjects who recalled overprotective parental behavior had higher hairsteroid-concentrations and dampened limbic-hypothalamic-pituitary-adrenal (LHPA) axis reactivity compared to German and Russian-German subjects with overprotective parents. We suggest that altered LHPA axis activity in maternally overprotected Jewish subjects may indicate a transmitted pathomechanism of "frustrated individuation" resulting from cross-generational anti-Semitic experiences. Thus measurements of hairsteroid-concentrations and parenting practices may have clinical value for diagnosis of PTSD. We propose that this apparent inherited adaptivity of LHPA axis activity could promote higher individual stress resistance, albeit with risk of an allostatic overload.
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Ansiedad/fisiopatología , Ansiedad/psicología , Sistema Hipotálamo-Hipofisario/fisiopatología , Relaciones Madre-Hijo/psicología , Adulto , Afecto , Femenino , Holocausto/psicología , Humanos , Masculino , Madres/psicología , Sistema Hipófiso-Suprarrenal/fisiopatología , Trastornos por Estrés Postraumático/etiología , Trastornos por Estrés Postraumático/fisiopatología , Trastornos por Estrés Postraumático/psicología , Estrés Psicológico/fisiopatología , Estrés Psicológico/psicología , Adulto JovenRESUMEN
Parental upbringing may affect their offspring's mental state across the entire lifespan. Overprotective parental child-rearing style may increase the disease burden in the offspring. Furthermore, this child-rearing style may also play a pathogenetic role by transmitting trauma- and stressor-related disorders (TSRD) across generations. Studies with animals have demonstrated that the mother's immediate and expansive protection of the newborn decreases the limbic-hypothalamic-pituitary-adrenal (LHPA) axis activity in the offspring. However, few studies have investigated how stress impact humans raised in an overprotective manner. In a cross-sectional study with 40 healthy students recalling their overprotective upbringing, we show an increase in the dehydroepiandrostendione (DHEA) concentration and a reduction in the cortisol/DHEA-ratio in hair. Additionally, this child rearing style was associated with heightened indications of mental burden, depressiveness, and sense of coherence. Our results provide insight into the roots and consequences of psychological trauma across several generations. Further investigations focusing particularly on multigenerational transmission in extremely burdened families will augment our results.
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Sistema Hipotálamo-Hipofisario/fisiología , Conducta Materna/psicología , Conducta Paterna/psicología , Sistema Hipófiso-Suprarrenal/fisiología , Adolescente , Adulto , Depresión , Relaciones Familiares , Femenino , Humanos , Masculino , Relaciones Padres-Hijo , Sentido de Coherencia , Estrés Psicológico , Adulto JovenRESUMEN
Male infants and boys through early adolescence can undergo circumcision either for the sake of upholding religious traditions or for medical reasons. According to both, Jewish as well as Islamic tenets, circumcision is a religious rite symbolizing the bond with God. The World Health Organization (WHO), the United Nations Council (UNC) as well as the American Academy of Pediatrics (AAP), and the Centers for Disease Control and Prevention (CDC) strongly recommend circumcision to promote hygiene and prevent disease. This procedure has frequently been criticized by various communities claiming that circumcision in infancy and early adolescence were psychologically traumatizing with medical implications up into old age. Due to the lack of evidence concerning an alleged increase in vulnerability, we measured objective and subjective stress and trauma markers, including glucocorticoids from hair samples, in circumcised and non-circumcised males. We found no differences in long-term limbic-hypothalamic-pituitary-adrenal axis activity, subjective stress perception, anxiety, depressiveness, physical complaints, sense of coherence and resilience. Rather, an increase in the glucocorticoid levels indicated a healthy lifestyle and appropriate functioning. Thus, our findings provide evidence that male circumcision does not promote psychological trauma. Moreover, a qualitative approach, the ambivalence construct, was used for the discussion, aiming at a discourse devoid of biases.
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Circuncisión Masculina/psicología , Cortisona/metabolismo , Hidrocortisona/metabolismo , Trauma Psicológico/psicología , Estrés Psicológico/psicología , Adulto , Estudios de Casos y Controles , Estudios Transversales , Glucocorticoides/metabolismo , Cabello/química , Humanos , Masculino , Trauma Psicológico/metabolismo , Estrés Psicológico/metabolismo , Adulto JovenRESUMEN
Currently, the quantitative analysis of moderators affecting the function of the hypothalamus-pituitary-adrenal (HPA)-axis in health and sickness is still unreliable. This is, in particular, due to physiological factors such as pulsatile ultradian and circadian glucocorticoid secretion as well as to methodological limitations of the current techniques for steroid hormone determination. Based on this background, the determination of long-term hair steroid concentrations is an important methodological improvement allowing for the quantitative analysis of chronic HPA axis-activation. In order to determine the relationship between chronic mental and physical stress and a chronic activation of the HPA axis, we performed a cross-sectional pilot-study with 40 healthy students and examined the relationships between physical activity, mental burden(s), subjective stress perceptions, depressiveness, anxiety, physical complaints, sense of coherence, resilience, and the long-term integrated steroid hormone levels in hair. The results showed that the concentrations of cortisol, cortisone, and dehydroepiandrosterone in hair were significantly correlated to mental (p = 0.034) and physical stress (p = 0.001) as well as to subjective stress perception (p = 0.006). We conclude that steroid concentrations in hair are decisive predictors for an increase in the long-term-HPA axis activity. Moreover, this biomarker is suitable for capturing the stresslevel after burdening events and physical activity.
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Cortisona/análisis , Deshidroepiandrosterona/análisis , Cabello/química , Hidrocortisona/análisis , Estrés Psicológico/metabolismo , Adulto , Biomarcadores/análisis , Estudios Transversales , Ejercicio Físico , Femenino , Humanos , Sistema Hipotálamo-Hipofisario/metabolismo , Masculino , Proyectos Piloto , Sistema Hipófiso-Suprarrenal/metabolismo , Resiliencia Psicológica , Estrés Fisiológico , Adulto JovenRESUMEN
"OBJECTIVE: This clinical practice guideline addresses the diagnosis and treatment of primary adrenal insufficiency. PARTICIPANTS: The Task Force included a chair, selected by The Clinical Guidelines Subcommittee of the Endocrine Society, eight additional clinicians experienced with the disease, a methodologist, and a medical writer. The co-sponsoring associations (European Society of Endocrinology and the American Association for Clinical Chemistry) had participating members. The Task Force received no corporate funding or remuneration in connection with this review. EVIDENCE: This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system to determine the strength of recommendations and the quality of evidence. CONSENSUS PROCESS: The evidence used to formulate recommendations was derived from two commissioned systematic reviews as well as other published systematic reviews and studies identified by the Task Force. The guideline was reviewed and approved sequentially by the Endocrine Society's Clinical Guidelines Subcommittee and Clinical Affairs Core Committee, members responding to a web posting, and the Endocrine Society Council. At each stage, the Task Force incorporated changes in response to written comments. CONCLUSIONS: We recommend diagnostic tests for the exclusion of primary adrenal insufficiency in all patients with indicative clinical symptoms or signs. In particular, we suggest a low diagnostic (and therapeutic) threshold in acutely ill patients, as well as in patients with predisposing factors. This is also recommended for pregnant women with unexplained persistent nausea, fatigue, and hypotension. We recommend a short corticotropin test (250 µg) as the ""gold standard"" diagnostic tool to establish the diagnosis. If a short corticotropin test is not possible in the first instance, we recommend an initial screening procedure comprising the measurement of morning plasma ACTH and cortisol levels. Diagnosis of the underlying cause should include a validated assay of autoantibodies against 21-hydroxylase. In autoantibody-negative individuals, other causes should be sought. We recommend once-daily fludrocortisone (median, 0.1 mg) and hydrocortisone (15-25 mg/d) or cortisone acetate replacement (20-35 mg/d) applied in two to three daily doses in adults. In children, hydrocortisone (â¼8 mg/m(2)/d) is recommended. Patients should be educated about stress dosing and equipped with a steroid card and glucocorticoid preparation for parenteral emergency administration. Follow-up should aim at monitoring appropriate dosing of corticosteroids and associated autoimmune diseases, particularly autoimmune thyroid disease."
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Humanos , Insuficiencia Suprarrenal , Insuficiencia Suprarrenal/diagnóstico , Insuficiencia Suprarrenal/terapia , Embarazo , Terapia de Reemplazo de EstrógenoAsunto(s)
Trauma Psicológico , Refugiados/psicología , Adolescente , Adulto , Femenino , Alemania , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenAsunto(s)
Endocrinología/historia , California , Historia del Siglo XX , Historia del Siglo XXI , HumanosRESUMEN
Vitreo-retinal surgery is challenging, as delicate structures have to be manipulated. Eliminating tremor caused by human motions when doing micromanipulation can therefore improve the outcome of such an intervention. An eye surgery robot has been built to overcome this problem. The contribution of this paper is the design of a telemanipulation setup for the robotic system. A telemanipulation setup using a haptic device featuring force feedback as a user interface for controlling a hybrid parallel-serial micromanipulator is designed and developed. The position error control scheme is chosen and different control modes are provided. The output forces of the haptic device are analyzed. The system allows the surgeon to perform precise and comfortable micromanipulation. Nevertheless a way to provide more meaningful force feedback still has to be found.
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Procedimientos Quirúrgicos Oftalmológicos/instrumentación , Procedimientos Quirúrgicos Robotizados/instrumentación , Diseño de Equipo , Retroalimentación , Humanos , Micromanipulación , Procedimientos Quirúrgicos Oftalmológicos/métodos , Retina/cirugía , Procedimientos Quirúrgicos Robotizados/métodos , Cuerpo Vítreo/cirugíaRESUMEN
Transplantation of islet cells is an effective treatment for type 1 diabetes with critically labile metabolic control. However, during islet isolation, blood supply is disrupted, and the transport of nutrients/metabolites to and from the islet cells occurs entirely by diffusion. Adequate oxygen supply is essential for function/survival of islet cells and is the limiting factor for graft integrity. Recently, we developed an immunoisolated chamber system for transplantation of human islets without immunosuppression. This system depended on daily oxygen supply. To provide independence from this external source, we incorporated a novel approach based on photosynthetically-generated oxygen. The chamber system was packed sandwich-like with a slab of immobilized photosynthetically active microorganisms (Synechococcus lividus) on top of a flat light source (LEDs, red light at 660 nm, intensity of 8 µE/m(2)/s). Islet cells immobilized in an alginate slab (500-1,000 islet equivalents/cm(2)) were mounted on the photosynthetic slab separated by a gas permeable silicone rubber-Teflon membrane, and the complete module was sealed with a microporous polytetrafluorethylene (Teflon) membrane (pore size: 0.4 µm) to protect the contents from the host immune cells. Upon illumination, oxygen produced by photosynthesis diffused via the silicone Teflon membrane into the islet compartment. Oxygen production from implanted encapsulated microorganisms was stable for 1 month. After implantation of the device into diabetic rats, normoglycemia was achieved for 1 week. Upon retrieval of the device, blood glucose levels returned to the diabetic state. Our results demonstrate that an implanted photosynthetic bioreactor can supply oxygen to transplanted islets and thus maintain islet viability/functionality.
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Trasplante de Islotes Pancreáticos/instrumentación , Islotes Pancreáticos/metabolismo , Oxígeno/metabolismo , Fotosíntesis , Animales , Diabetes Mellitus Experimental/metabolismo , Humanos , Masculino , Consumo de Oxígeno , Ratas Endogámicas Lew , Reproducibilidad de los Resultados , Synechococcus/metabolismoRESUMEN
Revascularisation of transplanted islets is an essential prerequisite for graft survival and function. However, current islet isolation procedures deprive the islets of endothelial tubulets. This may have a detrimental effect on the revascularisation process of islets following transplantation. We hypothesise that modification of the isolation procedure that preserves islet endothelial vessels may improve the islet revascularisation process following transplantation. Here, we present a modified islet isolation method by which a substantial amount of endothelial cells still attached to the islets could be preserved. The islets with preserved endothelial cells isolated by this method were revascularised within 3 days, not observed in islets isolated by standard methods. Further, we observed that grafts of islets isolated by standard methods had more patches of dead tissue than islet grafts obtained by the modified method, indicating that attached endothelial cells may play an important role in the islet revascularisation process and potentially help to improve the transplantation outcome.
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Supervivencia de Injerto , Trasplante de Islotes Pancreáticos , Adulto , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Endoglina , Células Endoteliales/metabolismo , Femenino , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Persona de Mediana Edad , Receptores de Superficie Celular/metabolismo , Donantes de Tejidos , Resultado del TratamientoAsunto(s)
Investigación Biomédica/organización & administración , Conducta Cooperativa , Diabetes Mellitus/patología , Diabetes Mellitus/terapia , Células Secretoras de Insulina , Trasplante de Islotes Pancreáticos , Alemania , Humanos , Células Secretoras de Insulina/citología , Células Secretoras de Insulina/patología , Células Secretoras de Insulina/fisiología , Londres , Regeneración , Linfocitos T/inmunologíaAsunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Administración Oral , Quimioterapia Combinada , Péptido 1 Similar al Glucagón/antagonistas & inhibidores , Humanos , Hipoglucemiantes/efectos adversos , Insulina Detemir , Insulina de Acción Prolongada , Atención Dirigida al Paciente , Guías de Práctica Clínica como AsuntoRESUMEN
This study analyses new information on gene mutations in paragangliomas and puts them into a clinical context. A suspicion of malignancy is critical to determine the workup and surgical approach in adrenal (A-PGL) and extra-adrenal (E-PGL) paragangliomas (PGLs). Malignancy rates vary with location, family history, and gene tests results. Currently there is no algorithm incorporating the above information for clinical use. A sum of 1,821 articles were retrieved from PubMed using the search terms "paraganglioma genetics". Thirty-seven articles were selected of which 9 were analyzed. It was found that 599/2,487 (24%) patients affected with paragangliomas had a germline mutation. Of these 30.2% were mutations in SDHB, 25% VHL, 19.4% RET, 18.4% SDHD, 5.0% NF1, and 2.0% SDHC genes. A family history was positive in 18.1-64.3% of patients. Adrenal PGLs accounted for 55.1% in mutation (+) and 81.0% in mutation (-) patients (RR 1.2, p < 0.0001). Bilateral A-PGLs accounted for 56.4% in mutation (+) and 3.2% in mutation (-) patients (RR 8.7, p < 0.0001). E-PGL were found in 33.6% of mut+ and 17.3% of mut- (RR 1.7, p < 0.0001). In mutation (+) patients PGLs malignancy varied with location, adrenal (6.4%) thoraco-abdominal E-PGL (38%), H & N E-PGL (10%). Malignancy rates were 8.2% in mutation (-) and lower in mutation (+) PGLs except for SDHB 36.5% and SDHC 8.3%. Exclusion of a mutation lowered the probability of malignancy significantly in E-PGL (RR 0.03 (95% CI 0.1-0.6); p < 0.001). Mutation analysis provides valuable preoperative information to assess the risk of malignancy in A-PG and E-PGLs and should be considered in the work up of all E-PGL lesions.
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Predisposición Genética a la Enfermedad , Paraganglioma/genética , Paraganglioma/patología , Familia , Humanos , Mutación/genética , Tasa de MutaciónRESUMEN
BACKGROUND: Parathyroid cancer has a poor mid-term prognosis, often because of local recurrence, observed in half of all patients. Modern diagnostic workup increasingly enables a preoperative diagnosis of parathyroid cancer. There is limited evidence that more comprehensive oncologic surgery can reduce the risk of local recurrence. This study aims to identify the best specific surgical approach in parathyroid cancer. METHODS: This observational cohort study comprises 19 consecutive patients who had undergone oncologic or nononcologic resection for parathyroid cancer. Baseline parameters were compared by using univariate analysis; outcomes were assessed by χ (2) testing and Kaplan-Meier statistics. RESULTS: Fifteen of 19 patients were primarily operated on in our tertiary center between 1996 and 2013, and four were referred for follow-up because of their cancer diagnosis. Patient cohorts defined by histologic R-status were comparable for established risk factors: sex, calcium levels, low-risk/high-risk status, and presence of vascular invasion. Oncologic resections were performed in 13 of 15 patients primarily treated in the center and 0 of 4 treated elsewhere (χ (2) = 5.6; p < 0.01). R0 margins were achieved in 11 of 13 (85 %) undergoing oncologic resection and 1 of 6 (17 %) undergoing local excision (χ (2) = 8.1; p < 0.01). R0 margins and primary oncologic resection were associated with higher disease-free survival rates (χ (2) = 7.9; p = 0.005 and χ (2) = 4.7; p = 0.03, respectively). Revision surgery achieved R0 margins in only 2 of 4 (50 %) of patients. CONCLUSIONS: In parathyroid cancer, a more comprehensive surgery (primary oncologic resection) provides significantly better outcomes than local excision as a result of reduction of R1 margins and locoregional recurrence.
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Disección del Cuello , Recurrencia Local de Neoplasia , Neoplasias de las Paratiroides/mortalidad , Neoplasias de las Paratiroides/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neoplasia Residual , Reoperación , Estudios RetrospectivosAsunto(s)
Codo , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/genética , Enfermedades Cutáneas Genéticas/diagnóstico , Proteínas Adaptadoras Transductoras de Señales/genética , Colesterol/sangre , Aberraciones Cromosómicas , Análisis Mutacional de ADN , Diagnóstico Diferencial , Femenino , Genes Recesivos , Humanos , Hiperlipoproteinemia Tipo II/patología , Piel/patología , Enfermedades Cutáneas Genéticas/sangre , Enfermedades Cutáneas Genéticas/genética , Enfermedades Cutáneas Genéticas/patología , Adulto JovenAsunto(s)
Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/fisiopatología , Hipoglucemiantes/farmacocinética , Hipoglucemiantes/uso terapéutico , Terapia Molecular Dirigida/métodos , Farmacogenética , Medicina de Precisión/métodos , Predisposición Genética a la Enfermedad/genética , Predisposición Genética a la Enfermedad/prevención & control , Humanos , Farmacogenética/métodosRESUMEN
Since 2007, children and adolescents with Hodgkin lymphomas are treated in the Europe-wide EuroNet-PHL trials. A real time central review process for stratification of the patients enhances quality control and efficient therapy management. This process includes reading of all cross-sectional-images. Since reference evaluation is time critical, a fast, easy to handle and safe data transfer is important. In addition, immediate and constant access to all the data has to be guaranteed in case of queries and for regulatory reasons. To meet the mentioned requirements the EuroNet Paediatric Hodgkin Data Network (funded by the European Union - Project Number: 2007108) was established between 2008 and 2011. A respective tailored data protection plan was formulated. The aim of this article is to describe the networks' mode of operation and the advantages for multi-centre trials that include centralized image review.
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Ensayos Clínicos como Asunto/estadística & datos numéricos , Redes de Comunicación de Computadores/organización & administración , Sistemas de Administración de Bases de Datos/organización & administración , Diagnóstico por Imagen , Unión Europea , Enfermedad de Hodgkin/terapia , Estudios Multicéntricos como Asunto/estadística & datos numéricos , Sistemas de Información Radiológica/organización & administración , Adolescente , Niño , Seguridad Computacional , Recolección de Datos , Europa (Continente) , Humanos , Control de CalidadRESUMEN
The mental health status of persons with Jewish background living in Germany is discussed with special regard to social exclusion like anti-Semitism and overprotective parental rearing behavior, as a transmissional factor of the KZ-Syndrome. These stressors are considered in the context of a higher risk for depression/fear and psychosomatic disorders and also abnormal cortisol levels. The present sample (N=89) is derived from the Jewish population currently living in the German region of Saxony aged between 17-36 years that emigrated from the post-Soviet-Union areas. The mean age was 22.9 years. Two questionnaires to detect psychosomatic symptoms (Giessen complaint list (GBB)-24, hospital anxiety and depression scale) and one questionnaire addressing parental rearing behavior (FEE) were employed. Comparisons were drawn with normative data from the literature about the German residential population. In addition, questions were asked concerning the experience of anti-Semitism in Germany and in the post-Soviet-Union areas. A higher prevalence of depression/fear (10.3% versus 18.2%) and psychosomatic symptoms (M=14.03 versus 17.8; t=2.42; P<0.05) was observed in Jewish migrants to Germany as compared with non-Jewish German residents. Furthermore, anti-Semitic experiences in Germany correlated positively with depression (r=0.293; P<0.01) and fear (r=0.254; P<0.05). The anti-Semitic experiences in the post-Soviet-Union areas also correlated positively with limb pain (r=0.41, P<0.01), fatigue symptoms (r=0.296, P<0.01) and psychocardial symptoms (r=0.219, P<0.05). It was also confirmed that the male respondents recalled a controlling and overprotecting maternal rearing behavior more frequently than the German standard random sample (M=15.39 versus 18.6; t=2.68; P<0.01). The latter also correlated significantly positive with epigastric pain (r=0.349; P<0.01). The present results show that depression, fear and psychosomatic problems are common in Jewish residents with a background of migration from the post-Soviet-Union areas to Germany. Apart from the transgenerational passing of psychological traumata and the Holocaust experiences, other stressors like anti-Semitism, control and overprotection as parental rearing measures appear to be important factors specifically contributing to the pathogenesis of the attributed symptoms.
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Depresión/etnología , Emigrantes e Inmigrantes/psicología , Holocausto/psicología , Judíos/psicología , Trastornos Psicofisiológicos/etnología , Racismo/psicología , Adolescente , Adulto , Niño , Crianza del Niño/etnología , Crianza del Niño/psicología , Femenino , Alemania/epidemiología , Humanos , Masculino , Prevalencia , Encuestas y Cuestionarios , U.R.S.S./etnologíaRESUMEN
Even though premating isolation is hypothesized to be a major driving force in speciation, its genetic basis is poorly known. In the noctuid moth Heliothis subflexa, one group of sex pheromone components, the acetates, emitted by the female, plays a crucial isolating role in preventing interspecific matings to males of the closely related Heliothis virescens, in which females do not produce acetates and males are repelled by them. We previously found intraspecific variation in acetates in H. subflexa: females in eastern North America contain significantly more acetates than females in Western Mexico. Here we describe the persistence of this intraspecific variation in laboratory-reared strains and the identification of one major quantitative trait locus (QTL), explaining 40% of the variance in acetate amounts. We homologized this intraspecific QTL to our previously identified interspecific QTL using restriction-associated DNA (RAD) tags. We found that a major intraspecific QTL overlaps with one of the two major interspecific QTL. To identify candidate genes underlying the acetate variation, we investigated a number of gene families with known or suspected acetyl- or acyltransferase activity. The most likely candidate genes did not map to our QTL, so that we currently hypothesize that a transcription factor underlies this QTL. Finding a single, large QTL that impacts variation in pheromone blends between and within species is, to our knowledge, the first such example for traits that have been demonstrated to affect premating isolation.