58 research outputs found

    Crisponi syndrome/cold-induced sweating syndrome type 2: Reprogramming of CS/CISS2 individual derived fibroblasts into three clones of one iPSC line

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    Crisponi syndrome/cold-induced sweating syndrome type 2 (CS/CISS2) is a rare disease with severe dysfunctions of thermoregulatory processes. CS/CISS2 individuals suffer from recurrent episodes of hyperthermia in the neonatal period and paradoxical sweating at cold ambient temperatures in adolescence. Variants in CLCF1 (cardiotrophin-like-cytokine 1) cause CS/CISS2. Here, we summarize the generation of three clones of one stem cell line (iPSC) of a CS/CISS2 individual carrying the CLCF1 variant c.321C>G on both alleles. These patient derived iPSC clones show a normal karyotype, several pluripotency markers, and the ability to differentiate into the three germ layers

    Evaluating Systematic Dependencies of Type Ia Supernovae: The Influence of Deflagration to Detonation Density

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    We explore the effects of the deflagration to detonation transition (DDT) density on the production of Ni-56 in thermonuclear supernova explosions (type Ia supernovae). Within the DDT paradigm, the transition density sets the amount of expansion during the deflagration phase of the explosion and therefore the amount of nuclear statistical equilibrium (NSE) material produced. We employ a theoretical framework for a well-controlled statistical study of two-dimensional simulations of thermonuclear supernovae with randomized initial conditions that can, with a particular choice of transition density, produce a similar average and range of Ni-56 masses to those inferred from observations. Within this framework, we utilize a more realistic "simmered" white dwarf progenitor model with a flame model and energetics scheme to calculate the amount of Ni-56 and NSE material synthesized for a suite of simulated explosions in which the transition density is varied in the range 1-3x10^7 g/cc. We find a quadratic dependence of the NSE yield on the log of the transition density, which is determined by the competition between plume rise and stellar expansion. By considering the effect of metallicity on the transition density, we find the NSE yield decreases by 0.055 +/- 0.004 solar masses for a 1 solar metallicity increase evaluated about solar metallicity. For the same change in metallicity, this result translates to a 0.067 +/- 0.004 solar mass decrease in the Ni-56 yield, slightly stronger than that due to the variation in electron fraction from the initial composition. Observations testing the dependence of the yield on metallicity remain somewhat ambiguous, but the dependence we find is comparable to that inferred from some studies.Comment: 15 pages, 13 figures, accepted to ApJ on July 6, 201

    Severe, very early onset preeclampsia in a Covid 19-positive woman with a twin pregnancy presenting with a hydatidiform mole and coexisting normal fetus: a case report

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    Cases of hydatidiform moles with a coexisting fetus are sparse and patients are at high risk for severe complications. Patients and physicians often face the dilemma of the wish to continue pregnancy until viability of the fetus while the risk for maternal complications increases. We present an educational case of a twin pregnancy presenting with a hydatidiform mole and coexisting normal fetus with a placenta praevia. The patient developed severe, early onset preeclampsia with beginning HELLP-syndrome and was tested Covid-19 positive in the further course. Termination of pregnancy was conducted via caesarean section at 18 + 6 weeks of pregnancy. Histopathology and genetic analysis confirmed a complete hydatidiform mole next to a normal placenta. Close follow-up examinations were conducted and showed normal findings including ß HCG levels normalizing within 5 months. This case combines several rare, difficult and severe medical conditions and demonstrates how an individualized therapy by an interdisciplinary team covering a highly sensitive topic was developed in a situation where no guidelines exist

    Cardiac Subtype-Specific Modeling of Kv1.5 Ion Channel Deficiency Using Human Pluripotent Stem Cells

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    The ultrarapid delayed rectifier K+ current (IKur), mediated by Kv1.5 channels, constitutes a key component of the atrial action potential. Functional mutations in the underlying KCNA5 gene have been shown to cause hereditary forms of atrial fibrillation (AF). Here, we combine targeted genetic engineering with cardiac subtype-specific differentiation of human induced pluripotent stem cells (hiPSCs) to explore the role of Kv1.5 in atrial hiPSC-cardiomyocytes. CRISPR/Cas9-mediated mutagenesis of integration-free hiPSCs was employed to generate a functional KCNA5 knockout. This model as well as isogenic wild-type control hiPSCs could selectively be differentiated into ventricular or atrial cardiomyocytes at high efficiency, based on the specific manipulation of retinoic acid signaling. Investigation of electrophysiological properties in Kv1.5-deficient cardiomyocytes compared to isogenic controls revealed a strictly atrial-specific disease phentoype, characterized by cardiac subtype-specific field and action potential prolongation and loss of 4-aminopyridine sensitivity. Atrial Kv1.5-deficient cardiomyocytes did not show signs of arrhythmia under adrenergic stress conditions or upon inhibiting additional types of K+ current. Exposure of bulk cultures to carbachol lowered beating frequencies and promoted chaotic spontaneous beating in a stochastic manner. Low-frequency, electrical stimulation in single cells caused atrial and mutant-specific early afterdepolarizations, linking the loss of KCNA5 function to a putative trigger mechanism in familial AF. These results clarify for the first time the role of Kv1.5 in atrial hiPSC-cardiomyocytes and demonstrate the feasibility of cardiac subtype-specific disease modeling using engineered hiPSCs

    From Reversible Quantum Microdynamics to Irreversible Quantum Transport

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    The transition from reversible microdynamics to irreversible transport can be studied very efficiently with the help of the so-called projection method. We give a concise introduction to that method, illustrate its power by using it to analyze the well-known rate and quantum Boltzmann equations, and present, as a new application, the derivation of a source term accounting for the spontaneous creation of electron-positron pairs in strong fields. Thereby we emphasize the fundamental importance of time scales: only if the various time scales exhibited by the dynamics are widely disparate, can the evolution of the slower degrees of freedom be described by a conventional Markovian transport equation; otherwise, one must account for finite memory effects. We show how the projection method can be employed to determine these time scales, and how --if necessary-- it allows one to include memory effects in a straightforward manner. Finally, there is an appendix in which we discuss the concepts of entropy and macroscopic irreversibility.Comment: Review article, 78 pages, uuencoded compressed PostScript fil

    Copy Number Variants in Patients with Severe Oligozoospermia and Sertoli-Cell-Only Syndrome

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    A genetic origin is estimated in 30% of infertile men with the common phenotypes of oligo- or azoospermia, but the pathogenesis of spermatogenic failure remains frequently obscure. To determine the involvement of Copy Number Variants (CNVs) in the origin of male infertility, patients with idiopathic severe oligozoospermia (N = 89), Sertoli-cell-only syndrome (SCOS, N = 37)) and controls with normozoospermia (N = 100) were analysed by array-CGH using the 244A/400K array sets (Agilent Technologies). The mean number of CNVs and the amount of DNA gain/loss were comparable between all groups. Ten recurring CNVs were only found in patients with severe oligozoospermia, three only in SCOS and one CNV in both groups with spermatogenic failure but not in normozoospermic men. Sex-chromosomal, mostly private CNVs were significantly overrepresented in patients with SCOS. CNVs found several times in all groups were analysed in a case-control design and four additional candidate genes and two regions without known genes were associated with SCOS (P<1×10−3). In conclusion, by applying array-CGH to study male infertility for the first time, we provide a number of candidate genes possibly causing or being risk factors for the men's spermatogenic failure. The recurring, patient-specific and private, sex-chromosomal CNVs as well as those associated with SCOS are candidates for further, larger case-control and re-sequencing studies

    Technikgenese: Einflußfaktoren der Technisierung jenseits traditioneller Technikfolgenforschung

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    Ausgehend davon, daß das Verhältnis von Technikgeneseforschung zu Technikfolgenforschung komplementär sein muß, werden in dem Beitrag die strukturellen, institutionellen und organisatorischen, die kognitiven wie perzeptiven Voraussetzungen dafür untersucht, welche Technikfolgen wie systematisch und rational in frühen Phasen der Technikentstehung wahrgenommen, berücksichtigt und technisch umgesetzt werden und welche nicht, um in der sozialwissenschaftlichen Rekonstruktion der Bedingungen technischer Innovationen die gesellschaftlichen und organisatorischen Einflußparameter, die Selektionsprozesse bei der Neueinführung von Techniken prägen, manifest werden zu lassen. Ziele und Grundlagen der sozialwissenschaftlichen Technikgeneseforschung werden dargestellt. Indem Technikgenese in organisationskulturellen Kontexten analysiert wird, wird ein neuer Forschungsansatz konzipiert, der im Kern beansprucht, das Selektions- und Entscheidungsverhalten von Organisationen mit Hilfe von Erklärungskategorien zu erfassen. Der zentrale Beitrag des organisationskulturellen Forschungsansatzes der Technikgenese liegt in der Möglichkeit, diejenigen Faktoren herauszukristallisieren, die eine Organisation dazu befähigen, innovative Impulse selbst zu generieren oder entsprechende Stimuli aus ihrer Umwelt aufzunehmen und umzusetzen. Abschließend wird das weitere Vorgehen sozialwissenschaftlicher Forschung zur Technikgenese skizziert. (ICA

    Androgen receptor gene mutations in androgen insensitivity syndrome cause distinct patterns of reduced activation of androgen-responsive promoter constructs

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    Assessment of quantitative impairment of reporter gene activation is an important strategy proving pathogenetic relevance of androgen receptor (AR)-gene mutations in androgen insensitivity syndrome (AIS). We hypothesized the additional existence of mutation-specific patterns of reduced target gene activation. Four AR-gene mutations causing AIS, L712F, M780I, R855H, and V866M, respectively, were recreated in an AR-expression plasmid. Activation of three structurally different androgen-dependent promoters (MMTV, (ARE)2TATA, and GRE-OCT) was measured in transfected CHO-cells in response to dihydrotestosterone (DHT), testosterone, androstenedione and stanozolol (S). V866M showed the lowest activity across all conditions. R855H exhibited strikingly high activation of MMTV in response to DHT. M780I showed markedly low activation of (ARE)2TATA by S. L712F demonstrated high activation of GRE-OCT. In essence, each mutation was characterized in this model by a specific pattern of reduced reporter gene activation. Our AR crystal structure analyses showed that L712 and M780 may cause distinct alterations of AR-ligand- and AR-coregulator interaction interfaces supporting the experimental observations. Our data support the hypothesis that mutations of the AR-gene in AIS induce mutation-specific patterns of reduced promoter activation in vitro. Considering the diversity of natural androgen-regulated promoters, mutation-specific differences of androgen response patterns may be of relevance in vivo and consequently may influence the AIS-phenotype. Assessment of transactivation patterns in vitro may be an interesting concept to extend functional description of AR-gene mutations in AIS
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