Hyperhomocysteinemia has been proposed to inhibit the protein C anticoagulant system through 2 mechanisms: decreased generation of activated protein C (APC) by thrombin, and resistance to APC caused by decreased inactivation of factor Va (FVa). We tested the hypotheses that generation of APC by thrombin is impaired in hyperhomocysteinemia in monkeys and that hyperhomocysteinemia produces resist...

Resistance to the anticoagulant effect of activated protein C (APC resistance), a frequent abnormality in patients with a history of venous thrombosis, is known to be due, in the large majority of cases, to the presence of an abnormal factor V: the factor V Leiden. It is reasonable to surmise that screening for this abnormality should be performed with a clotting method for APC resistance, befo...

Resistance to chemotherapy is one of the leading causes of death from breast cancer. We recently established that loss of Adenomatous Polyposis Coli (APC) in the Mouse Mammary Tumor Virus - Polyoma middle T (MMTV-PyMT) transgenic mouse model results in resistance to cisplatin or doxorubicin-induced apoptosis. Herein, we aim to establish the mechanism that is responsible for APC-mediated chemoth...

objectives: familial adenomatous polyposis (fap) is an autosomal dominant predisposition to colon cancer. this hereditary genetic disease is characterized by more than 100 adenomatous polyps in colon and rectum. additional features may include desmoids tumors, polyps in the upper gastrointestinal tract, osteomas and congenital hypertrophy of the retinal pigment epithelium (chrpe). a mutation in...

V ENOUS THROMBOEMBOLISM, with an annual incidence of 1/1,000, is a serious medical problem causing considerable suffering and occasional death.‘-3 Thrombosis tends to occur in conjunction with surgery, fractures, inflammatory states, immobilization, pregnancy, and the use of oral contraceptives, demonstrating circumstantial risk factors to be of importance in the pathogenesis. In addition, thro...

We present a case of a 24 year old woman who became pregnant (twins) after human menopausal gonadotrophin (HMG)-induced ovarian stimulation, in-vitro fertilization (IVF) and subsequent embryo transfer. She developed a right internal jugular vein thrombosis as a complication of severe ovarian hyperstimulation syndrome (OHSS) 28 days after embryo transfer. The thrombosis developed in spite of ant...

Antibodies against phospholipids (PLa) are often thought to be associated with the development of activated protein C (APC) resistance. In the present study, PLa were followed throughout 29 healthy pregnancies and compared to APC resistance. The level of PLa did not change during pregnancy [6.9 +/- 3.7 GPL week 12 versus 6.3 +/- 2.8 GPL week 37; 3.3 +/- 1.8 MPL versus 3.2 +/- 1.5 MPL; and lupus...

Background/Aim. Direct oral anticoagulants (DOACs) administration significantly interferes with coagulation as-says. The aim of the study was to evaluate effect DOACs and DOAC-Remove? on assays during thrombophilia testing. Methods. carried out from January 2019 end June 2020. It included 30 DOAC-treated patients, 14 females 16 males aged 23 63 (median age 47.6 years), tested for due venous thr...

Activated protein C (APC) resistance, both in its congenital form, due to the factor V Leiden mutation, and in its acquired form, are important risk factors for systemic venous thrombosis. In view of the suspected thrombotic aetiology of some cases of recurrent miscarriage, the prevalence of APC resistance was determined among 1111 consecutive Caucasian women with a history of either recurrent ...

Coagulation factor V (FV) promotes inactivation of activated factor VIII (FVIIIa) by activated protein C (APC) and protein S. Loss of this APC cofactor activity is proposed to be partially responsible for the APC resistance phenotype of FV Leiden . However, FVIIIa loses activity rapidly due to dissociation of the A2 domain, and this may be the primary mechanism of FVIIIa inactivation. APC/prote...