62 research outputs found
Preimplantation genetic testing legislation and accessibility in the Nordic countries
Abstract Introduction Assisted Reproduction Technologies are in rapid development and implementation of preimplantation genetic testing (PGT) has allowed patients with genetic disorders to initiate pregnancies while minimizing or eliminating the risk of transmitting these disorders to their offspring. Testing for numeric chromosomal anomalies has been proposed as a way to increase efficacy in assisted reproduction, however this remains disputed. Legislation is lagging behind the rapid developments in this field. Material and methods We conducted a structured online survey of legislation and accessibility to Preimplantation Genetic Testing in the Nordic countries to compare the regulation and uptake of this technique. The survey was designed and answered by the authors. Results Key elements in regulation of preimplantation testing for monogenic disorders and structural rearrangements are similar in the Nordic countries although accessibility varies since only Denmark, Finland and Sweden have national clinics offering treatment. In addition, Denmark and Finland have private clinics offering PGT. Regulation is most stringent in Norway where a national board evaluates all couples seeking treatment. Treatment volumes vary between the Nordic countries with Norway and Finland having lowest treatment numbers. Preimplantation genetic testing for aneuploidy in the embryo varies between the Nordic countries where Finland and Iceland are allowed to offer this form of treatment, Denmark and Sweden only in the form of a research protocol while this form of testing is not allowed at all in Norway. Therefore the number of treatment cycles involving testing for embryo aneuploidy are lower in the Nordic countries compared to other countries where this treatment option is more common. Conclusions Science needs to inform politics regarding the rapidly evolving field of reproductive medicine and we recommend harmonization of legislation and accessibility between the Nordic countries.Peer reviewe
Angiopoietin-like protein 4 is an exercise-induced hepatokine in humans, regulated by glucagon and cAMP
Objective: Angiopoietin-like protein-4 (ANGPTL4) is a circulating protein that is highly expressed in liver and implicated in regulation of plasma triglyceride levels. Systemic ANGPTL4 increases during prolonged fasting and is suggested to be secreted from skeletal muscle following exercise.
Methods: We investigated the origin of exercise-induced ANGPTL4 in humans by measuring the arterial-to-venous difference over the leg and the hepato-splanchnic bed during an acute bout of exercise. Furthermore, the impact of the glucagon-to-insulin ratio on plasma ANGPTL4 was studied in healthy individuals. The regulation of ANGPTL4 was investigated in both hepatic and muscle cells.
Results: The hepato-splanchnic bed, but not the leg, contributed to exercise-induced plasma ANGPTL4. Further studies using hormone infusions revealed that the glucagon-to-insulin ratio is an important regulator of plasma ANGPTL4 as elevated glucagon in the absence of elevated insulin increased plasma ANGPTL4 in resting subjects, whereas infusion of somatostatin during exercise blunted the increase of both glucagon and ANGPTL4. Moreover, activation of the cAMP/PKA signaling cascade let to an increase in ANGPTL4 mRNA levels in hepatic cells, which was prevented by inhibition of PKA. In humans, muscle ANGPTL4 mRNA increased during fasting, with only a marginal further induction by exercise. In human muscle cells, no inhibitory effect of AMPK activation could be demonstrated on ANGPTL4 expression.
Conclusions: The data suggest that exercise-induced ANGPTL4 is secreted from the liver and driven by a glucagon-cAMP-PKA pathway in humans. These findings link the liver, insulin/glucagon, and lipid metabolism together, which could implicate a role of ANGPTL4 in metabolic diseases
Cell-based non-invasive prenatal testing for monogenic disorders:confirmation of unaffected fetuses following preimplantation genetic testing
PURPOSE: Proof of concept of the use of cell-based non-invasive prenatal testing (cbNIPT) as an alternative to chorionic villus sampling (CVS) following preimplantation genetic testing for monogenic disorders (PGT-M). METHOD: PGT-M was performed by combined testing of short tandem repeat (STR) markers and direct mutation detection, followed by transfer of an unaffected embryo. Patients who opted for follow-up of PGT-M by CVS had blood sampled, from which potential fetal extravillous throphoblast cells were isolated. The cell origin and mutational status were determined by combined testing of STR markers and direct mutation detection using the same setup as during PGT. The cbNIPT results with respect to the mutational status were compared to those of genetic testing of the CVS. RESULTS: Eight patients had blood collected between gestational weeks 10 and 13, from which 33 potential fetal cell samples were isolated. Twenty-seven out of 33 isolated cell samples were successfully tested (82%), of which 24 were of fetal origin (89%). This corresponds to a median of 2.5 successfully tested fetal cell samples per case (range 1–6). All fetal cell samples had a genetic profile identical to that of the transferred embryo confirming a pregnancy with an unaffected fetus, in accordance with the CVS results. CONCLUSION: These findings show that although measures are needed to enhance the test success rate and the number of cells identified, cbNIPT is a promising alternative to CVS. TRIAL REGISTRATION NUMBER: N-20180001 SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10815-021-02104-5
Identification of Multiple HPV Types on Spermatozoa from Human Sperm Donors
Human papillomaviruses (HPV) may cause sexually transmitted disease. High-risk types of HPV are involved in the development of cervical cell dysplasia, whereas low-risk types may cause genital condyloma. Despite the association between HPV and cancer, donor sperm need not be tested for HPV according to European regulations. Consequently, the potential health risk of HPV transmission by donor bank sperm has not been elucidated, nor is it known how HPV is associated with sperm. The presence of 35 types of HPV was examined on DNA from semen samples of 188 Danish sperm donors using a sensitive HPV array. To examine whether HPV was associated with the sperm, in situ hybridization were performed with HPV-6, HPV-16 and -18, and HPV-31-specific probes. The prevalence of HPV-positive sperm donors was 16.0% and in 66.7% of these individuals high-risk types of HPV were detected. In 5.3% of sperm donors, two or more HPV types were detected. Among all identified HPV types, 61.9% were high-risk types. In situ hybridization experiments identified HPV genomes particularly protruding from the equatorial segment and the tail of the sperm. Semen samples from more than one in seven healthy Danish donors contain HPV, most of them of high-risk types binding to the equatorial segment of the sperm cell. Most HPV-positive sperm showed decreased staining with DAPI, indicative of reduced content of DNA. Our data demonstrate that oncogenic HPV types are frequent in men
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