ABSTRACT
A 30-year-old nurse presented with abdominal pain and tenderness. Her blood tests, including amylase, were normal. Urinary amylase was extremely high. The source of the increased urinary amylase was found to be the patient's saliva-she had spat into her urine sample. Subsequent investigation showed that she had Munchausen syndrome.
ABSTRACT
Heparanase is an endoglycosidase that degrades heparan sulfate on the cell surface and extracellular matrix. The physiological functions of heparanase include heparan sulfate turnover, embryo development, hair growth, and wound healing. Heparanase is implicated in a variety of pathologies, such as tumor growth, angiogenesis, metastasis, inflammation, and glomerular diseases. Heparanase overexpression in a variety of malignant tumors suggests that it could be a target for anti-cancer therapy.
Subject(s)
Extracellular Matrix/enzymology , Glucuronidase/metabolism , Heparitin Sulfate/metabolism , Neoplasms/enzymology , Alternative Splicing , Animals , Extracellular Matrix/chemistry , Gene Expression Regulation, Enzymologic , Glucuronidase/antagonists & inhibitors , Glucuronidase/genetics , Heparan Sulfate Proteoglycans/metabolism , Heparin/genetics , Heparin/metabolism , Humans , Neoplasms/pathology , Neoplasms/therapy , Protein Precursors/genetics , Protein Precursors/metabolismABSTRACT
A 30-year-old nurse presented with abdominal pain and tenderness. Her blood tests, including amylase, were normal. Urinary amylase was extremely high. The source of the increased urinary amylase was found to be the patient's saliva - she had spit into her urine sample. Subsequent investigation showed that she had Munchausen's syndrome.
Subject(s)
Amylases/urine , Munchausen Syndrome/urine , Nurses , Abdominal Pain , Adult , Diagnosis, Differential , Emergencies , Female , Humans , Saliva/enzymology , Specimen HandlingABSTRACT
BACKGROUND: Heparanase is a mammalian endo-D-glucuronidase that cleaves heparan sulfate (HS) in the extracellular matrix and cell surface. It is preferentially expressed by cells of the immune system and tumor cells. Heparanase overexpression in experimental tumor models results in increased angiogenesis and metastasis. Heparin and low-molecular weight heparin (LMWH) inhibit HS degradation by heparanase. OBJECTIVE: To investigate whether heparanase cleaves heparin and LMWH, and elucidate its effect on blood coagulation. METHODS: Heparin and LMWH were incubated with recombinant heparanase and subjected to measurements of molecular size (size exclusion chromatography) and anticoagulant activity (plasma APTT-activated thromboplastin time, and anti-Xa activity). APTT was also measured in plasma samples of transgenic mice overexpressing heparanase, in comparison with control mice. RESULTS: Incubation of heparin and LMWH with heparanase resulted in degradation of these substrates, as revealed by a significant decrease in their molecular weight. This was correlated with a marked suppression of the anticoagulant activity of heparin and LMWH, as indicated by a decreased effect on APTT and anti-Xa activity, respectively, when human plasma was added. Transgenic mice overexpressing heparanase exhibited a significantly shorter APTT than control mice. CONCLUSION: Heparanase is capable of degrading heparin and LMWH, so that its overexpression by tumor cells may contribute to heparin resistance, commonly occurring in cancer patients. In view of the complexity of the currently available heparanase activity assays, we propose an indirect approach to quantify heparanase activity by measuring the decrease in plasma APTT or anti-Xa activity exerted by the enzyme under the defined conditions.