Expression of multidrug-resistance P-glycoprotein (MDR1) in human brain tumors.

Multidrug resistance (MDR) is associated with the expression of P-glycoprotein (P-gp), an ATP-dependent transporter which expels anti-cancer drugs from cells. In the present study, MDR1 P-gp was immunodetected by Western blot analysis in 60 human brain tumors, including meningiomas, schwannomas, low-grade gliomas (astrocytomas, pilocytic astrocytomas) and high-grade gliomas (anaplastic astrocytomas, glioblastomas and anaplastic oligodendrogliomas). Most samples from primary tumors expressed P-gp at the same levels as normal brain tissue except for schwannomas, in which levels were reduced by 65%, and meningiomas, in which levels were more than 10-fold higher in 7 of 10 samples. P-gp levels were 70% and 95% lower in brain metastases from melanomas and lung adenocarcinomas, respectively, than in normal brain tissue. These results indicate that the majority of primary brain tumors express MDR1 P-gp and that its high expression levels in meningiomas may be a marker for this type of brain tumor.

Why remove an infected aortofemoral graft?

The radical treatment of infected vascular grafts is a major procedure with a high mortality and loss of limb. The authors review their experience with 13 consecutive cases of infected aortofemoral grafts treated conservatively during an 11-year period. The treatment consisted of wide incision and drainage of the infected area followed by assiduous irrigation with an antiseptic or antibiotic solution. In 10 patients the inguinal wound healed and the prosthesis was reincorporated; 8 of the 10 had a patent prosthesis and the treatment was considered successful, while 2 needed further surgery. Three patients died of hemorrhage or sepsis. Follow-up ranged from 8 to 144 months (mean 77 months). Two patients had a false aneurysm 3 and 7 years after wound healing. The results compare favourably with those of radical treatment. The authors believe a conservative approach must always be tried as the first step in the management of infected vascular prostheses. The gratifying results observed in their series, in both the short and long term, support this conservative approach, which is a satisfying alternative to radical operations with their high mortality and morbidity.

Celiac compression syndrome.

The authors present their experience at the Hôpital St-Luc in Montreal with seven patients who had celiac compression syndrome. All underwent section of the median arcuate ligament to free the celiac axis and resection of the connecting nerve fibers of the solar plexus (periarterial neurectomy). At a mean follow-up of 36 months all patients were asymptomatic. In some cases, extrinsic compression of the celiac axis by the arcuate ligament can explain upper abdominal plain. An epigastric bruit in the presence of a normal digestive tract is an indication for lateral aortography to detect extrinsic compression. The pain in this syndrome cannot be explained solely on hemodynamic grounds; surgical treatment should include release of the celiac axis and complete periarterial neurectomy.

Arteriography and pancreatic disease.

In the last 10 years, 605 celiomesenteric arteriographic examinations were done at Hôtel-Dieu de Montréal, including 236 for suspected pancreatic disease. Sixty patients with histologic proof of malignant neoplasm had a positive arteriographic examination while 136 had benign disease of the pancreas and 40 others had extra-pancreatic disease. In this series, the sensitivity of arteriography was 88.3% and the specificity 92.6%. In the last 5 years the sensitivity of superselective arteriography was 100%. These results were better than those obtained with noninvasive techniques obtained with noninvasive techniques such as computerized axial tomography, ultrasonography and duodenography. The authors conclude that arteriography and particularly superselective arteriography is an excellent method for evaluating patients with suspected pancreatic cancer.