Background-The formation of prostacyclin (PGI 2 ), thromboxane (TX) A 2 , and isoprostanes is markedly enhanced in atherosclerosis. We examined the relative contribution of cyclooxygenase (COX)-1 and -2 to the generation of these eicosanoids in patients with atherosclerosis. Methods and Results-The study population consisted of 42 patients with atherosclerosis who were undergoing surgical revascularization. COX-2 mRNA was detected in areas of atherosclerosis but not in normal blood vessel walls, and there was evidence of COX-1 induction. The use of immunohistochemical studies localized the COX-2 to proliferating vascular smooth muscle cells and macrophages. Twenty-four patients who did not previously receive aspirin were randomized to receive either no treatment or nimesulide at 24 hours before surgery and then for 3 days. Eighteen patients who were receiving aspirin were continued on a protocol of either aspirin alone or a combination of aspirin and nimesulide. Urinary levels of 11-dehydro-TXB 2 and 2,3-dinor-6-keto-PGF 1␣ , metabolites of TXA 2 and PGI 2 , respectively, were elevated in patients with atherosclerosis compared with normal subjects (3211Ϯ533 versus 679Ϯ63 pg/mg creatinine, PϽ0.001; 594Ϯ156 versus 130Ϯ22 pg/mg creatinine, PϽ0.05, respectively), as was the level of the isoprostane 8-iso-PGF 2␣ . Nimesulide reduced 2,3-dinor-6-keto-PGF 1␣ excretion by 46Ϯ5% (378.3Ϯ103 to 167Ϯ37 pg/mg creatinine, PϽ0.01) preoperatively and blunted the increase after surgery. Nimesulide had no significant effect on 11-dehydro-TXB 2 before (2678Ϯ694 to 2110Ϯ282 pg/mg creatinine) or after surgery. The levels of both products were lower in patients who were taking aspirin, and no further reduction was seen with the addition of nimesulide. None of the treatments influenced urinary 8-iso-PGF 2␣ excretion. Conclusions-Both COX-1 and -2 are expressed and contribute to the increase in PGI 2 in patients with atherosclerosis, whereas TXA 2 is generated by COX-1. (Circulation. 2000;102:840-845.)

A lyophilized kit formulation for the efficient labelling of lipiodol with generator-produced rhenium-188 is described. The preliminary preparation of the lipophilic complex bis-(diethyldithiocarbamato)nitrido rhenium-188 (188ReN-DEDC) was carried out using a two-vial kit containing S-methyl-N-methyl-dithiocarbazate, SnCl2 and sodium oxalate in the first vial, and diethyldithiocarbamate and a carbonate buffer in the second vial. After mixing of the reaction solution with lipiodol, the complex 188ReN-DEDC was quantitatively extracted and retained by this hydrophobic substance, thus allowing the stable incorporation of the beta-emitting radionuclide. The radiochemical purity of the complex 188ReN-DEDC was 97+/-2%. The activity extracted into the lipiodol phase was 96+/-3% of the initial activity, indicating that the complex 188ReN-DEDC was almost quantitatively removed from the aqueous reaction solution. In vitro stability studies in human plasma, at 37 degrees C, demonstrated the release of less than 15% of the activity within three half-lives. The biodistribution of Re-lipiodol in non-tumour-bearing Wistar rats at 6, 24, 48 and 72 h after intraportal venous injection showed one-third of total activity in the liver at 6 h, declining to 2% retention at 72 h. Bowel uptake at 6 and 24 h declined to low levels at 48 and 72 h. Renal activity peaked at 1.7%, diminishing to 0.6% over 48 h. Rat whole body gamma imaging showed gut activity in addition to hepatic uptake at 6 and 24 h, but only liver was evident from 48 to 72 h. Kidneys were not demonstrable at any imaging time point. In nine patients, activity was localized in the tumours immediately following intrahepatic arterial injection. Computed tomography/single-photon emission computed tomography (CT/SPECT) imaging at 1 and 24 h confirmed the retention of 188Re-lipiodol in the hepatoma, with minimal gut uptake and no lung activity over 24 h. These patients were subsequently treated with activities of 2.5-5 GBq of 188Re-lipiodol fractions without adverse effects. Six patients followed for up to 2 years in the pilot study achieved stable disease and there was objective partial response in one patient. Repeated treatments were performed on two to three occasions in three patients without evident toxicity. An additional patient given 6 GBq of 188Re-lipiodol demonstrated myelosuppression, which recovered with granulocyte colony-stimulating factor (GCSF) and platelet support. It is concluded that 188Re-lipiodol, prepared using our novel kit formulation, is stable in vivo and provides safe and effective therapy of unresectable hepatocellular carcinoma when given via the hepatic artery, either alone or in combination with transarterial chemoembolization.

Immediate cytologic evaluation improved results marginally with increased procedure time and needle passes. Immediate cytologic evaluation may be most useful for lesions at lowest risk of complications to assure that a second procedure is not required.

To determine observer variation in the detection of acetabular bone deficiencies, 42 pairs of frontal (AP) and lateral hip radiographs and CT studies for total hip arthroplasty patients obtained within an average of 4 weeks of each other were reviewed separately by five radiologists and one orthopedic surgeon. Interobserver variations were calculated for each individual reading the films using kappa values. The individual film readings were then compared with a consensus reading of the CT data. When separate observers were analyzed, agreement on plain film readings was slight to fair (av. kappa = 0.1440 +/- 0.1047). The individual observers were not able to give readings which were very consistent with the CT consensus reading, resulting in a low sensitivity (65%) and specificity (74%) for acetabular defect classification with plain radiographs. The identification of acetabular bone defects from the AP and lateral views of the hip is highly subjective and variable from observer to observer.