Ângelo do Carmo Silva Matthes

Determination of cyclophosphamide enantiomers in plasma by LC-MS/MS: Application to pharmacokinetics in breast cancer and lupus nephritis patients.

This article describes the enantioselective analysis of cyclophosphamide (CPA) in human plasma using LC-MS/MS. CPA enantiomers were extracted from plasma using a mixture of ethyl acetate and chloroform (75:25, v/v). The enantiomers were separated on a Chiralcel(R) OD-R column, with the mobile phase consisting of a mixture of acetonitrile and water (75:25, v/v) plus 0.2% formic acid. The protonated ions and their respective product ions were monitored using two functions, 261 > 141 for CPA enantiomers and 189 > 104 for the internal standard (antipyrine). Recovery rates were higher than 95% and the quantification limit was 2.5-ng/ml plasma for both enantiomers. The coefficients of variation and the relative errors obtained for the validation of intra- and interassay precision and accuracy were less than 10%. The method was applied for the investigation of the enantioselective pharmacokinetics of CPA in a lupus nephritis patient treated with 1 g CPA infused over 2 h and in a breast cancer patient treated with 0.9 g infused over 1 h. No stereoselectivity in the pharmacokinetic parameters was observed for either patient. Clearance values of 2.63 and 2.93 l/h and of 3.36 and 3.61 l/h for (-)-(S) and (+)-(R)-CPA were obtained for the breast cancer and lupus nephritis patient, respectively.

Estudo da correlação entre o estadiamento clínico e as alterações esqueléticas das metástases ósseas do câncer da mama

Forty-eight breast cancer patients with bone metastases were studied aiming to evaluate the correlation between clinical staging of the primary tumor, according to the Cancer Staging American Committee protocol, and the skeletal manifestations of the bone metastases; the assessment parameters were the follow-up period, the number of metastases, the type of the lesions, their localization, and the affected bone region. A correlation was found between the primary lesion staging and the follow-up period, which was reduced when the staging degree increased; no correlation was observed between breast cancer clinical staging and the other parameters.

Sangramento maciço em cirurgia onco-ginecológica: uso do pack hemostático

Purpose: to introduce the use of the hemostatic pack, a tampon consisting of compresses tied to the bleeding surface and left in place for 48 to 72 h and which is one of the therapeutic alternatives to be used in this situation. Patients and Methods: we evaluated 3 cases of massive bleeding during surgery, with the exchange, on average, of 1.4 blood volumes (1.2-2.4), in terms of hemostatic effectiveness of the pack and of some patient parameters such as age and amount and type of volume infused. Results: the mean age of the patients was 57 years (51, 56 and 64). Only one had been previously irradiated. The bleeding was of venous origin, from the fossa of the obturator nerve, the iliac plexus and the presacral plexus. The volume expander most often used was 0.9% physiological saline solution, followed by blood derivatives and by Ringer lactate. Two patients were submitted to ligation of the hypogastric vein during surgery, with no improvement. The use of hemostatic synthetic material was inefficient in all three cases. In one of the patients, the use of nonabsorbable sutures to close the bleeding area led to a considerable reduction of bleeding, but did not eliminate it completely. One patient died before 24 h had elapsed, with signs and symptoms of heart failure. The other two patients developed acute renal failure and one of them developed aspirative pneumonia during surgical reexploration. Conclusion: massive bleeding is related to high morbidity and mortality. Among the emergency measures used for hemostasis, the pack seems to be the most adequate.