However, the theory of Boveri was forgotten until the molecular biologist Peter Duesberg reappraised it. Understanding through what mechanisms it can affect tumor evolution is an important topic of current cancer research.Somatic mosaicism occurs in virtually all cancer cells, including trisomy 12 in chronic lymphocytic leukemia (CLL) and trisomy 8 in acute myeloid leukemia (AML). However, these forms of mosaic aneuploidy occur through mechanisms distinct from those typically associated with genetic syndromes involving complete or mosaic aneuploidy, such as chromosomal instability (due to mitotic segregation defects in cancer cells). Therefore, the molecular processes that lead to aneuploidy are targets for the development of cancer drugs. Both resveratrol and aspirin have been found in vivo (in mice) to selectively destroy tetraploid cells that may be precursors of aneuploid cells, and activate AMPK, which may be involved in the process.Alteration of normal mitotic checkpoints are also important tumorigenic events, and these may directly lead to aneuploidy. Loss of tumor suppressor p53 gene often results in genomic instability, which could lead to the aneuploidy genotype.In addition, genetic syndromes in which an individual is predisposed to breakage of chromosomes (chromosome instability syndromes) are frequently associated with increased risk for various types of cancer, thus highlighting the role of somatic aneuploidy in carcinogenesis.The ability to evade the immune system appears to be enhanced in tumoral cells with strong aneuploidy. This has therefore suggested that the presence of an abnormal number of chromosomes might be an effective predictive biomarker for response to precise immunotherapy.
Only when the site of detachment occurs on the side facing the cervical opening can the total amount of haemorrhaging be measured by vaginal bleeding. Using vaginal bleeding as a measurement of the severity of the placental abruption is therefore ineffective. The scale of haemorrhaging depends on the degree to which the placenta has separated from the uterine wall. In the case of partial placental separation, haemorrhaging can be minor. However, in the case of total placental separation haemorrhaging will be major and emergency delivery will typically be the course of action. Placental abruption causes blood loss from the mother and loss of oxygen and nutrients to the placenta occasionally leading to preterm labour. Other causes of placental abruption can be abdominal trauma or sudden decompression of amniotic fluid, however it is not uncommon for the cause of placental abruption to be unknown. Vasa praevia
Vasa praevia is the presence of unprotected foetal blood vessels running along the placenta and over the internal cervical opening. Vasa praevia is a very rare, presenting only 4:10,000 cases from the largest study of the condition. Risks of antepartum bleeding due to vasa praevia greatly increase during the third trimester of pregnancy during cervical dilation or placenta praevia. Vessel rupture is very likely in the event of a membranous rupture as foetal blood vessels arent protected by the umbilical cord of the placenta. In the event of foetal vessel rupture, antepartum haemorrhaging occurs however blood is lost from the foetal blood supply.