[Coumarin-induced necrotic purpura of the skin -- case report and review of the literature]

We report the case of a 28-year old woman with extensive red-black colored lesions of the skin on the left thigh, which appeared without trauma. The disease arrived during longterm coumarin therapy because of a deep vein thrombosis and an antiphospholipid syndrome. After consideration of the differential diagnoses and due to the typical clinical picture we made the diagnosis of coumarin necrosis. We review the clinical and therapeutic features for this rare complication.

Recurrent ischemic colitis in a patient with leiden factor V mutation and systemic lupus erythematous with antiphospholipid syndrome

Ischemic colitis results from insufficient blood supply to the large intestine and is often associated with hypercoagulable states. The condition comprises a wide range presenting with mild to fulminant forms. Diagnosis remains difficult because these patients may present with non-specific abdominal symptoms. We report a 51- year-old female patient with known Leiden factor V mutation as well as systemic lupus erythematous along with antiphospholipid syndrome suffering from recurrent ischemic colitis. At admission, the patient complained about abdominal pain, diarrhea and rectal bleeding lasting for 24 hours. Laboratory tests showed an increased C-reactive protein (29.5 mg/dl), while the performed abdominal CT-scan revealed only a dilatation of the descending colon along with a thickening of the bowel wall. Laparotomy was performed showing an ischemic colon and massive peritonitis. Histological examination proved the suspected ischemic colitis. Consecutively, an anti-coagulation therapy with coumarin and aspirin 100 was initiated. Up to the time point of a follow up examination no further ischemic events had occurred. This case illustrates well the non-specific clinical presentation of ischemic colitis. A high index of suspicion, recognition of risk factors and a history of non-specific abdominal symptoms should alert the clinicians to the possibility of ischemic disease. Early diagnosis and initiation of anticoagulation therapy or surgical intervention in case of peritonitis are the major goals of therapy.

Bleeding complications following Nd:YAG laserassisted oral surgery vs conventional treatment in cardiac risk patients: a clinical retrospective comparative study

OBJECTIVE Thermal Nd:YAG laser energy is well known for the purpose of blood coagulation. However, little is known about the bleeding frequency following laser-assisted oral surgery in patients on coumarin drugs. Therefore, the purpose of this study was to compare retrospectively the frequency of bleeding complications following Nd:YAG laserassisted versus conventional local coagulation of blood in oral surgery. METHOD AND MATERIALS In October 2002, minor oral surgical interventions were found to be indicated in a total of 45 cardiac risk patients. In Group 1, blood coagulation was yielded in 24 patients with a Nd:YAG laser system, whereas in Group 2, treatment was performed in 21 patients with conventional means of local hemostasis. All therapies were performed continuing anticoagulant therapy between November 2002 and March 2003. Clinical data were recorded retrospectively from patient charts in May 2007. RESULTS In both Groups 1 and 2, a total of two bleeding complications were recorded. However, local re-interventions were sufficient for local hemostasis. CONCLUSION These results indicate that Nd:YAG laser-assisted local hemostasis was not able to prevent bleeding complications completely. Within the limitations of this retrospective study it was concluded that in patients with anticoagulant treatment undergoing minor oral surgery, Nd:YAG laser-assisted local hemostasis is not superior to conventional methods of blood coagulation with respect to the frequency of bleeding complications.

Synthesis and cellular characterization of novel isoxazolo- and thiazolohydrazinylidene-chroman-2,4-diones on cancer and non-cancer cell growth and death

Coumarins are extensively studied anticoagulants that exert additional effects such as anticancerogenic and even anti-inflammatory. In order to find new drugs with anticancer activities, we report here the synthesis and the structural analysis of new coumarin derivatives which combine the coumarin core and five member heterocycles in hydrazinylidene-chroman-2,4-diones. The derivatives were prepared by derivatization of the appropriate heterocyclic amines which were used as electrophiles to attack the coumarin ring. The structures were characterized by spectroscopic techniques including IR, NMR, 2D-NMR and MS. These derivatives were further characterized especially in terms of a potential cytotoxic and apoptogenic effect in several cancer cell lines including the breast and prostate cancer cell lines MCF-7, MDA-MB-231, PC-3, LNCaP, and the monocytic leukemia cell line U937. Cell viability was determined after 48 h and 72 h of treatment with the novel compounds by MTT assay and the 50% inhibitory concentrations (EC50 values) were determined. Out of the 8 novel compounds screened for reduced cell viability, 4c, 4d and 4e were found to be the most promising and effective ones having EC50 values that were several fold reduced when compared to the reference substance 4-hydroxycoumarin. However, the effects were cancer cell line dependent. The breast cancer MDA-MB-231 cells, the prostate cancer LNCaP cells, and U937 cells were most sensitive, MCF-7 cells were less sensitive, and PC-3 cells were more resistant. Reduced cell viability was accompanied by increased apoptosis as shown by PARP-1 cleavage and reduced activity of the survival protein kinase Akt. In summary, this study has identified three novel coumarin derivatives that in comparison to 4-hydroxycoumarin have a higher efficiency to reduce cancer cell viability and trigger apoptosis and therefore may represent interesting novel drug candidates