Kaposi's sarcoma. CT-radiographic correlation

The role of CT in the diagnosis of intrathoracic Kaposi's sarcoma (KS) was evaluated retrospectively in 24 patients, in the absence of coexistent opportunistic infections. In all cases the diagnosis of KS was initially established by histologic evaluation of extrathoracic disease: 15 patients had verified parenchymal KS and nine patients endobronchial KS. (Chest roentgenograms were analyzed separately for each group: in 14 patients serial films were available for review. The predominant radiographic findings was the presence of nonspecific, bilateral, perihilar infiltrates in 22 of 24 cases (92 percent). Corresponding CT scans documented the presence of abnormal hilar densities characteristically extending into the adjacent pulmonary parenchyma along distinctly perivascular and peribronchial pathways. Discrete, poorly marginated nodules were identified radiographically in ten cases (42 percent); these proved to be randomly distributed throughout the parenchyma on CT. Radiographic evidence of mediastinal adenopathy was distinctly unusual, seen in only two cases (8 percent). While CT typically demonstrated shotty adenopathy, significantly enlarged nodes (greater than 1 cm) were rarely identified. We concluded that CT is more specific than routine roentgenograms for identifying pulmonary KS. While not pathognomonic, peribronchial and perivascular disease is sufficiently characteristic to obviate more invasive diagnostic procedures, especially in patients with established KS.     

Repair of large midline incisional hernias with polypropylene mesh: Comparison of three operative techniques

Polypropylene mesh is widely used for the reconstruction of incisional hernias that cannot be closed primarily. Several techniques have been advocated to implant the mesh. The objective of this study was to evaluate, retrospectively, early and late results of three different techniques, onlay, inlay, and underlay. The records of 53 consecutive patients with a large midline incisional hernia — 25 women and 28 men, mean age 60.4 (range 28–94) — were reviewed. Polypropylene mesh was implanted using the onlay technique in 13 patients, inlay in 23 patients, and underlay in 17 patients. Either the greater omentum or a polyglactin mesh was interponated between the mesh and the viscera. The records of these 53 patients were reviewed with respect to: size and cause of the hernia, pre- and postoperative mortality and morbidity, with special attention to wound complications. Patients were invited to attend the outpatient clinic at least 12 months after implantation of the mesh for physical examination of the abdominal wall. Postoperative complications occurred in 14 (26.4%) patients. The onlay technique had significantly more complications, as compared to both other techniques. Reherniation occurred in 15 (28.3%) patients. The reherniation rate of the inlay technique was significantly higher than after the underlay technique (44% vs 12%, P=0.03) and tended to be higher than the onlay technique (44% vs 23%, P=0.22). Repair of large midline incisional hernias with the use of a polypropylene mesh carries a high risk of complications and has a high reherniation rate. The underlay technique seems to be the better technique.     

Nonheme iron in sickle erythrocyte membranes: association with phospholipids and potential role in lipid peroxidation

Previous studies documented the abnormal association of heme and heme proteins with the sickle RBC membrane. We have now examined RBC ghosts and inside-out membranes (IOM) for the presence of nonheme iron as detected by its formation of a colored complex with ferrozine. Sickle ghosts have 33.8 +/- 18.2 nmol nonheme iron/mg membrane protein, and sickle IOM have 4.3 +/- 3.0 nmol/mg. In contrast, normal RBC ghosts and IOM have no detectable nonheme iron. The combination of heme and nonheme iron in sickle IOM averages nine times the amount of membrane- associated iron in normal IOM. Kinetics of the ferrozine reaction show that some of this nonheme iron on IOM reacts slowly and is probably in the form of ferritin, but most (72% +/- 18%) reacts rapidly and is in the form of some other biologic chelate. The latter iron compartment is removed by deferoxamine and by treatment of IOM with phospholipase D, which suggests that it represents an abnormal association of iron with polar head groups of aminophospholipids. The biologic feasibility of such a chelate was demonstrated by using an admixture of iron with model liposomes. Even in the presence of tenfold excess adenosine diphosphate, iron partitions readily into phosphatidylserine liposomes; there is no detectable association with phosphatidylcholine liposomes. To examine the bioavailability of membrane iron, we admixed membranes and t-butylhydroperoxide and found that sickle membranes show a tenfold greater peroxidation response than do normal membranes. This is not due simply to a deficiency of vitamin E, and this is profoundly inhibited by deferoxamine. Thus, while thiol oxidation in sickle membranes previously was shown to correlate with heme iron, the present data suggest that lipid peroxidation is related to nonheme iron. In control studies, we did not find this pathologic association of nonferritin, nonheme iron with IOM prepared from sickle trait, high-reticulocyte, postsplenectomy, or iron-overloaded individuals. These data provide additional support for the concept that iron decompartmentalization is a characteristic of sickle RBCs.     

Antihypertensive effect of canrenone in a model where endogenous ouabain-like factors are present

The effect of canrenone, an antialdosterone and partial ouabain-agonist drug, was studied in rats that developed volume expansion and hypertension after renal mass reduction and excess Na+ intake (RRM-salt). The RRM-salt was characterized by: (1) increased endogenous "digitalis-like" compounds in plasma [cross reactivity with digoxin-antibodies (57.5 +/- 5.0 vs. 42.1 +/- 3.8 pg/ml, p less than 0.02); inhibition of kidney Na+, K+-ATPase activity (135 +/- 5 vs. 154 +/- 5 mumol/mg/h, p less than 0.01); and inhibition of Na+ extrusion from normal erythrocytes (5.96 +/- 0.40 vs. 7.68 +/- 0.34 mmol/L cells/h, p less than 0.01)]; (2) reduced Na+, K+-pump activity (7.34 +/- 0.29 vs. 10.88 +/- 0.41 mmol/L cells/h, p less than 0.001) and increased Na+ content (4.66 +/- .08 vs. 4.16 +/- 0.11 mmol/L cells, p less than 0.01) in erythrocytes; and (3) low plasma renin activity (2.1 +/- 0.9 vs. 12.6 +/- 1.6 ng/ml/h). Ninety minutes after the administration to RRM-salt of a single oral dose of 60 mg/kg of canrenone, the systolic blood pressure decreased by 36 +/- 4 mm Hg (mean +/- SEM). Chronic canrenone administration (60 mg/kg/day) resulted in a marked antihypertensive effect associated to a correction of volume expansion, a decrease in endogenous "digitalis-like" compounds, and a partial recovery of Na+, K+-pump activity and Na+ content in erythrocytes. Our results suggest that the antihypertensive effect in RRM-salt rats results, at least in part, from antagonism with endogenous "digitalis-like" compounds.