Population genetic studies in the parasitic nematode Onchocerca ochengi

The filarial nematode Onchocerca ochengi is a nodule forming parasite of cattle and very closely related to the human parasite Onchocerca volvulus, the causative agent of river blindness. Both species are endemic in tropical and subtropical parts of Africa and share the same vectors which are blackflies of the Simulium damnosum complex. It is technically and ethically easier to study the basic biology of a pathogen in an animal model, likein this case the bovine parasite O. ochengithan in humans. To get better insights in the population structure and reproductive behavior of O. ochengi, the studies in this thesis make use of nuclear and mitochondrial molecular genetic markers. First I established methods for genotyping individual O. ochengi adults, embryos and microfilariae at single copy loci and I identified regions containing single nucleotide polymorphisms that could serve as molecular markers. I used these markers and method to determine parent offspring relationships. I showed that females often produce offspring from multiple males simultaneously. Most of the time, but not always, these putative fathers were still found in the nodules at the time their progeny was ready to hatch. This indicates that males, although they can leave nodules, tend to stay with a particular female for extended periods of time. I was able to assign a large fraction of microfilariae isolated from a skin sample to their parents and thereby show that different females contribute variably to the pool of skin microfilariae. Furthermore I showed that cattle is the vertebrate host of Onchocerca sp. „Siisa‟, a form of Onchocercapreviously described only in the vector O. sp. „Siisa‟ had been separated from other species of Onchocerca based on (only maternally inherited) mitochondrial DNA sequences. Using the bi-parentally inherited nuclear markers, I showed that O. sp. „Siisa‟ interbreeds freely with O. ochengiand therefore belongs to this species.Die zu den Nematoden gehörende Filarienart Onchocerca ochengi ist ein Knoten bildender Rinderparasit und sehr nah verwandt mit dem Parasiten des Menschen Onchocerca volvulus, Verursacher der Flussblindheit. Beide Arten sind im tropischen und subtropischen Afrika endemisch und teilen die gleichen Vektoren, nämlich Kriebelmücken des Simulium damnosumKomplex. Es ist technisch und ethisch einfacher die grundlegende Biologie eines Pathogens in einem Tiermodell, in diesem Fall der Rinder Parasit O. ochengi, als im Menschen zu untersuchen. Um bessere Einblicke in die Populationsstruktur und das Fortpflanzungs Verhalten von O. ochengi zu erhalten, werden für diese Arbeit nukleäre und mitochondrielle Marker genutzt. Zunächst habe ich die Methoden zur Genotypisierung von einzelnen O. ochengi Adulten, Embryonen und Mikrofilarien auf EinzelkopieNiveauetabliert und Regionen bestimmt, an denen Einzel Nukleotide Polymorphismen auftreten, die als molekulare Marker dienen. Diese Methoden und Marker habe ich genutzt um Eltern-Nachwuchs-Verhältnisse zu bestimmen. Dabei ergab sich, dass Weibchen oft Nachkommen von mehreren Männchen gleichzeitig haben. Meistens, aber nicht immer, sind diese vermutlichen Väter noch in den Knoten zu finden, wenn ihre Nachkommen bereit sind zu schlüpfen. Das zeigt, dass Männchen, obwohl sie die Knoten verlassen können, dazu tendieren für eine gewisse Zeit bei einem Weibchen zu bleiben. Ich konnte einen großen Anteil der Mikrofilarien aus einer Hautprobe ihren Eltern zuzuordnen und dabei zeigen, dass verschiedene Weibchen zu unterschiedlichen Anteilen zum Gesamtreservoir der Hautmikrofilarien beitragen. Des Weiteren konnte ich nachweisen, dass Rinder die Endwirte von Onchocerca sp. ‚Siisa„ sind. Letztere ist eine Form von Onchocerca die bisher nur im Vektor beschrieben wurde und aufgrund von (mütterlich vererbten) mitochondriellen DNS Sequenzen von anderen Onchocerca Arten abgegrenzt wurde. Mit Hilfe der biparental vererbten Nukleären Markern zeigte ich, dass O. sp. ‚Siisa„ frei mit O.ochengikreuzen und daher der gleichen Art angehören

Microbeam Irradiation as a Simultaneously Integrated Boost in a Conventional Whole-Brain Radiotherapy Protocol.

Microbeam radiotherapy (MRT), an experimental high-dose rate concept with spatial fractionation at the micrometre range, has shown a high therapeutic potential as well as good preservation of normal tissue function in pre-clinical studies. We investigated the suitability of MRT as a simultaneously integrated boost (SIB) in conventional whole-brain irradiation (WBRT). A 174 Gy MRT SIB was administered with an array of quasi-parallel, 50 µm wide microbeams spaced at a centre-to-centre distance of 400 µm either on the first or last day of a 5 × 4 Gy radiotherapy schedule in healthy adult C57 BL/6J mice and in F98 glioma cell cultures. The animals were observed for signs of intracranial pressure and focal neurologic signs. Colony counts were conducted in F98 glioma cell cultures. No signs of acute adverse effects were observed in any of the irradiated animals within 3 days after the last irradiation fraction. The tumoricidal effect on F98 cell in vitro was higher when the MRT boost was delivered on the first day of the irradiation course, as opposed to the last day. Therefore, the MRT SIB should be integrated into a clinical radiotherapy schedule as early as possible

Combined PARP and Dual Topoisomerase Inhibition Potentiates Genome Instability and Cell Death in Ovarian Cancer

Although ovarian cancer is a rare disease, it constitutes the fifth leading cause of cancer death among women. It is of major importance to develop new therapeutic strategies to improve survival. Combining P8-D6, a novel dual topoisomerase inhibitor with exceptional anti-tumoral properties in ovarian cancer and compounds in preclinical research, and olaparib, a PARP inhibitor targeting DNA damage repair, is a promising approach. P8-D6 induces DNA damage that can be repaired by base excision repair or homologous recombination in which PARP plays a major role. This study analyzed benefits of combining P8-D6 and olaparib treatment in 2D and 3D cultures with ovarian cancer cells. Measurement of viability, cytotoxicity and caspase activity were used to assess therapy efficacy and to calculate the combination index (CI). Further DNA damage was quantified using the biomarkers RAD51 and γH2A.X. The combinational treatment led to an increased caspase activity and reduced viability. CI values partially show synergisms in combinations at 100 nM and 500 nM P8-D6. More DNA damage accumulated, and spheroids lost their membrane integrity due to the combinational treatment. While maintaining the same therapy efficacy as single-drug therapy, doses of P8-D6 and olaparib can be reduced in combinational treatments. Synergisms can be seen in some tested combinations. In summary, the combination therapy indicates benefits and acts synergistic at 100 nM and 500 nM P8-D6

Mapping of a new locus for congenital anomalies of the kidney and urinary tract on chromosome 8q24

Background. Congenital anomalies of the kidney and urinary tract (CAKUT) account for the majority of end-stage renal disease in children (50%). Previous studies have mapped autosomal dominant loci for CAKUT. We here report a genome-wide search for linkage in a large pedigree of Somalian descent containing eight affected individuals with a non-syndromic form of CAKUT. Methods. Clinical data and blood samples were obtained from a Somalian family with eight individuals with CAKUT including high-grade vesicoureteral reflux and unilateral renal agenesis. Total genome search for linkage was performed using a 50K SNP Affymetric DNA microarray. As neither parent is affected, the results of the SNP array were analysed under recessive models of inheritance, with and without the assumption of consanguinity. Results. Using the non-consanguineous recessive model, a new gene locus (CAKUT1) for CAKUT was mapped to chromosome 8q24 with a significant maximum parametric Logarithm of the ODDs (LOD) score (LODmax) of 4.2. Recombinations were observed in two patients defining a critical genetic interval of 2.5 Mb physical distance flanked by markers SNP_A-1740062 and SNP_A-1653225. Conclusion. We have thus identified a new non-syndromic recessive gene locus for CAKUT (CAKUT1) on chromosome 8q24. The identification of the disease-causing gene will provide further insights into the pathogenesis of urinary tract malformations and mechanisms of renal developmen

Ecosystem mapping in the Central Arctic Ocean (CAO) during the SAS-Oden expedition

As a result of global warming, the marine ecosystem around the North Pole, the Central Arctic Ocean (CAO), is in fast transition from a permanently to a seasonally ice-covered ocean. The sea-ice loss is expected to enable summer access to the CAO for non-icebreaking ships, including fishery vessels, in the near future1. However, the lack of knowledge on the CAO ecosystem impedes any assessment of the sustainability of potential future fisheries in the CAO. Taking a precautionary approach, the EU and nine countries in October 2018 signed the Agreement to Prevent Unregulated High Seas Fisheries in the Central Arctic Ocean. This agreement entered into force in June 2021 and a.o. requires the establishment of a joint scientific program to improve the understanding of the CAO ecosystem, including mapping and monitoring. To reduce the existing lack of knowledge, 12 scientists from the EFICA Consortium participated, together with 26 other on-board scientists, in sampling and data collection of ecosystem data during the Swedish SAS-Oden expedition in summer 2021. This report describes the field work performed by the EFICA scientists using water-column acoustics, deep-sea optical observations, and fish, zooplankton, sediment otolith and eDNA sampling for targeting fish, zooplankton and mammals. Further ecosystem data (physical, chemical and biological) were collected by the EFICA scientists in collaboration with other scientists on-board. Together with this report, a metadata database containing lists of all collected samples and data that are relevant for future fish-stock modelling and assessment studies was delivered to the European Commission

Uncovering the (un-)occupied electronic structure of a buried hybrid interface

The energy level alignment at organic/inorganic (o/i) semiconductor interfaces is crucial for any light-emitting or -harvesting functionality. Essential is the access to both occupied and unoccupied electronic states directly at the interface, which is often deeply buried underneath thick organic films and challenging to characterize. We use several complementary experimental techniques to determine the electronic structure of p -quinquephenyl pyridine (5P-Py) adsorbed on ZnO(1 0   −1 0). The parent anchoring group, pyridine, significantly lowers the work function by up to 2.9 eV and causes an occupied in-gap state (IGS) directly below the Fermi level EF. Adsorption of upright-standing 5P-Py also leads to a strong work function reduction of up to 2.1 eV and to a similar IGS. The latter is then used as an initial state for the transient population of three normally unoccupied molecular levels through optical excitation and, due to its localization right at the o/i interface, provides interfacial sensitivity, even for thick 5P-Py films. We observe two final states above the vacuum level and one bound state at around 2 eV above EF, which we attribute to the 5P-Py LUMO. By the separate study of anchoring group and organic dye combined with the exploitation of the occupied IGS for selective interfacial photoexcitation, this work provides a new pathway for characterizing the electronic structure at buried o/i interfaces.Deutsche Forschungsgemeinschafthttps://doi.org/10.13039/501100001659Peer Reviewe

Effects of the Genetic Depletion of Polysialyltransferases on the Structure and Connectivity of Interneurons in the Adult Prefrontal Cortex

Polysialic acid (polySia) is a complex sugar that in the nervous system appears mainly as a posttranslational modification of the neural cell adhesion molecule (NCAM). PolySia plays important roles during brain development, but also in its plasticity during adulthood. Two polysialyltransferases (polyST), ST8SIA2 and ST8SIA4, are involved in the synthesis and attachment of polySia. Both polyST are relevant for developmental migration of cortical interneurons and their establishment in the prefrontal cortex (PFC). In contrast, only ST8SIA4 appears to be important for the structural plasticity of a subpopulation of cortical interneurons in the adult. Interestingly, ST8SIA2 and NCAM are candidate genes for schizophrenia, a disorder in which interneuronal circuits are altered. However, there is still no data on the effects of polyST depletion on the dendritic structure or the connectivity of cortical interneurons. Here, we studied the contribution of each polyST on these parameters in the medial PFC (mPFC) of polyST knock-out mice with GAD67-GFP-labeled interneurons. Genetic depletion of ST8SIA4, but not ST8SIA2, resulted in a decrease in the complexity of the dendritic arbor of interneurons. In contrast, ablation of either of the two polyST induced a decrease in the density of parvalbumin (PV) expressing perisomatic puncta on pyramidal neurons. Thus, the depletion of each polyST results in similar impairments of not only developmental migration but also efferent synaptic connectivity of interneurons. In contrast, the loss of ST8SIA4 has a unique effect on dendritic structure, hence on afferent connectivity, suggesting differential and independent contributions of each polyST to neuritogenesis and synaptogenesis

OLDEST OLD IN THE HOUSEHOLD: THE FAMILY AS UNIT OF CARE

OBJETIVO: O estudo objetivou analisar como a família se organiza enquanto unidade de cuidado a idosos mais velhos no espaço domiciliar, com base no Modelo Calgary de Avaliação Familiar. MÉTODO: Estudo de caráter qualitativo, descritivo. A coleta dos dados ocorreu por meio de entrevistas, avaliando três núcleos familiares. RESULTADOS: Baseados nas categorias que compõe o Modelo e na análise de conteúdo analisaram-se os aspectos da estrutura, desenvolvimento e funcionamento das famílias, abrangendo a dinâmica socioeconômica da organização familiar, o papel do idoso e sua influência na relação familial, a necessidade de cuidado, aspectos emocionais e vínculo afetivo que (re)organizam a estrutura familiar. CONCLUSÃO: A relação familiar e a complexidade dos vínculos que o idoso mantém são fundamentais para a preservação de sua saúde, especialmente nos aspectos relativos à dependência de cuidados. Considera-se importante maior inserção da equipe de enfermagem nesse espaço visando adequar a assistência em saúde à organização familiar. 

OLDEST OLD IN THE HOUSEHOLD: THE FAMILY AS UNIT OF CARE

OBJETIVO: O estudo objetivou analisar como a família se organiza enquanto unidade de cuidado a idosos mais velhos no espaço domiciliar, com base no Modelo Calgary de Avaliação Familiar. MÉTODO: Estudo de caráter qualitativo, descritivo. A coleta dos dados ocorreu por meio de entrevistas, avaliando três núcleos familiares. RESULTADOS: Baseados nas categorias que compõe o Modelo e na análise de conteúdo analisaram-se os aspectos da estrutura, desenvolvimento e funcionamento das famílias, abrangendo a dinâmica socioeconômica da organização familiar, o papel do idoso e sua influência na relação familial, a necessidade de cuidado, aspectos emocionais e vínculo afetivo que (re)organizam a estrutura familiar. CONCLUSÃO: A relação familiar e a complexidade dos vínculos que o idoso mantém são fundamentais para a preservação de sua saúde, especialmente nos aspectos relativos à dependência de cuidados. Considera-se importante maior inserção da equipe de enfermagem nesse espaço visando adequar a assistência em saúde à organização familiar. 

ARHGDIA mutations cause nephrotic syndrome via defective RHO GTPase signaling

Nephrotic syndrome (NS) is divided into steroid-sensitive (SSNS) and -resistant (SRNS) variants. SRNS causes end-stage kidney disease, which cannot be cured. While the disease mechanisms of NS are not well understood, genetic mapping studies suggest a multitude of unknown single-gene causes. We combined homozygosity mapping with whole-exome resequencing and identified an ARHGDIA mutation that causes SRNS. We demonstrated that ARHGDIA is in a complex with RHO GTPases and is prominently expressed in podocytes of rat glomeruli. ARHGDIA mutations (R120X and G173V) from individuals with SRNS abrogated interaction with RHO GTPases and increased active GTP-bound RAC1 and CDC42, but not RHOA, indicating that RAC1 and CDC42 are more relevant to the pathogenesis of this SRNS variant than RHOA. Moreover, the mutations enhanced migration of cultured human podocytes; however, enhanced migration was reversed by treatment with RAC1 inhibitors. The nephrotic phenotype was recapitulated in arhgdia-deficient zebrafish. RAC1 inhibitors were partially effective in ameliorating arhgdia-associated defects. These findings identify a single-gene cause of NS and reveal that RHO GTPase signaling is a pathogenic mediator of SRNS.ope