HNE-derived 2-pentylpyrroles are generated during oxidation of LDL, are more prevalent in blood plasma from patients with renal disease or atherosclerosis, and are present in atherosclerotic plaques

Free radical oxidation of human plasma low-density lipoprotein (LDL) produces 2-pentylpyrrole epitopes that are generated by reaction of 4-hydroxy-2-nonenal (HNE), a product of lipid oxidation, with protein lysyl residues. The HNE-derived 2-pentylpyrrole ("HNE-pyrrole") epitopes were detected with an enzyme-linked immunosorbent assay (ELISA) using antibodies (ON-KLH) raised against protein-bound 2-pentylpyrrole obtained by the reaction of 2-oxononanal (ON) with keyhole limpet hemocyanin (KLH). HNE-pyrrole epitopes in human plasma are not associated primarily with LDL protein, apolipoprotein (apo) B, since only 15% of the total HNE-pyrrole immunoreactivity is removed by immunoprecipitation of apo B. The levels of ON-KLH immunoreactivity detected in human plasma were found to be significantly elevated in renal failure and atherosclerosis patients when compared to those in healthy volunteers. HNE-pyrrole immunoreactivity was also detected in atherosclerotic plaques. The highest levels were associated with extracellular connective tissue. Levels of ON-KLH immunoreactivity in human plasma far exceed levels of free HNE, presumably because of the rapid clearance of free relative to protein-bound HNE. Therefore, HNE-pyrrole epitopes provide a more indelible marker of oxidative injury than levels of free HNE.     

Accuracy of passive ankle joint positioning during quiet stance in young and elderly subjects

Age-related postural deficits elicit compensatory mechanisms such as ankle dorsiflexion in the elderly. To gain further insight into this problem, the ability to match an ankle angle during quiet stance was studied in 12 elderly and 12 young subjects. Following an initial single limb angular perturbation presented in the ±4° range, a subject had to return a tilt platform to level, as determined by the nonperturbed limb. Elderly subjects exhibited significant positive (0.9°) over-shoot of the level position, in contrast to young subjects who matched ankle angle with a mean error of −0.1°. The elderly group also exhibited an increase in positioning error for angular displacements in the range between −1 and +1°. The results document age-related postural changes in ankle positioning which might affect postural stability in older adults.     

Multiple myeloma: evaluation by CT

Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs.     

Supraacetabular insufficiency fractures

Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women.     

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.