University of Copenhagen

About: University of Copenhagen is a education organization based out in Copenhagen, Denmark. It is known for research contribution in the topics: Population & Medicine. The organization has 57645 authors who have published 149740 publications receiving 5903093 citations. The organization is also known as: Copenhagen University & Københavns Universitet.

Oxidants and antioxidants in disease: oxidative stress in farm animals.

Abstract: Important infectious diseases in farm animals, such as pneumonia and enteritis, are thought to be associated with the so-called oxidative stress, i.e. a chemical phenomenon involving an imbalance in the redox status of the individual animal. The specifics of oxidative stress and how it may result in disease or be prevented are complex questions with no simple answers. However, the considerable literature on the subject suggests that many researchers consider oxidative stress-related mechanisms to be important early events in disease development. A particularly intriguing aspect is that, at least theoretically, oxidative stress should be easily prevented with antioxidants yet the use of antioxidants as therapy remains controversial. The present knowledge on oxidative stress in farm animals is the topic of this review.

Replication fork stability confers chemoresistance in BRCA-deficient cells

Abstract: Cells deficient in the Brca1 and Brca2 genes have reduced capacity to repair DNA double-strand breaks by homologous recombination and consequently are hypersensitive to DNA-damaging agents, including cisplatin and poly(ADP-ribose) polymerase (PARP) inhibitors. Here we show that loss of the MLL3/4 complex protein, PTIP, protects Brca1/2-deficient cells from DNA damage and rescues the lethality of Brca2-deficient embryonic stem cells. However, PTIP deficiency does not restore homologous recombination activity at double-strand breaks. Instead, its absence inhibits the recruitment of the MRE11 nuclease to stalled replication forks, which in turn protects nascent DNA strands from extensive degradation. More generally, acquisition of PARP inhibitors and cisplatin resistance is associated with replication fork protection in Brca2-deficient tumour cells that do not develop Brca2 reversion mutations. Disruption of multiple proteins, including PARP1 and CHD4, leads to the same end point of replication fork protection, highlighting the complexities by which tumour cells evade chemotherapeutic interventions and acquire drug resistance.

Cathepsin B Acts as a Dominant Execution Protease in Tumor Cell Apoptosis Induced by Tumor Necrosis Factor

Abstract: Death receptors can trigger cell demise dependent or independent of caspases In WEHI-S fibrosarcoma cells, tumor necrosis factor (TNF) induced an increase in cytosolic cathepsin B activity followed by death with apoptotic features Surprisingly, this process was enhanced by low, but effectively inhibiting, concentrations of pan-caspase inhibitors Contrary to caspase inhibitors, a panel of pharmacological cathepsin B inhibitors, the endogenous cathepsin inhibitor cystatin A as well as antisense-mediated depletion of cathepsin B rescued WEHI-S cells from apoptosis triggered by TNF or TNF-related apoptosis-inducing ligand Thus, cathepsin B can take over the role of the dominant execution protease in death receptor-induced apoptosis The conservation of this alternative execution pathway was further examined in other tumor cell lines Here, cathepsin B acted as an essential downstream mediator of TNF-triggered and caspase-initiated apoptosis cascade, whereas apoptosis of primary cells was only minimally dependent on cathepsin B These data imply that cathepsin B, which is commonly overexpressed in human primary tumors, may have two opposing roles in malignancy, reducing it by its proapoptotic features and enhancing it by its known facilitation of invasion

The mechanism of sex determination in dioecious flowering plants.

Abstract: Publisher Summary Dioecism has arisen independently in different plant families and plant genera. In the majority of cases, the evolution of dioecism has apparently taken place on the species level; in some cases, on the subgeneric level (rumex) or generic level (humulus). Few families (salicaceae) comprise only dioecious species. Dioecious plants offer, in many cases, better tools for studying the genetics of sex determination than dioecious animals. First, the fact that dioecious plants have arisen independently gives an opportunity to study the different ways in which dioecism may become established. Second, in plants the step from dioecism to bisexuality is often a short one and in most cases, dioecism is not clear-cut. In many dioecious species (e.g. mercurialis), bisexual types are found in nature often with a rather high frequency. Such bisexual individuals of normally dioecious plant species are almost always fertile and can be genetically studied, whereas similar bisexual animals are sterile intersexes. In plants it is possible to follow both the evolution of dioecism from hermaphroditism (or monoecism) and the reverse process.

The EFSUMB guidelines and recommendations for the clinical practice of contrast-enhanced ultrasound (CEUS) in Non-Hepatic Applications: Update 2017 (Long Version)

Abstract: The updated version of the EFSUMB guidelines on the application of non-hepatic contrast-enhanced ultrasound (CEUS) deals with the use of microbubble ultrasound contrast outside the liver in the many established and emerging applications.