Ultrastructure, immunofluorescence, western blot, and PCR analysis of eight isolates of Encephalitozoon (Septata) intestinalis established in culture from sputum and urine samples and duodenal aspirates of five patients with AIDS

ONO-5046 is a potent, specific and intravenously active inhibitor of neutrophil elastase. To examine the role of elastase in glomerulonephritis, we tested the effects of ONO-5046 on nephrotoxic serum (NTS) nephritis in a rat model of the disease in humans. Rats were administered ONO-5046 or phosphate-buffered saline (PBS) intraperitoneally 24 hours prior to injection of NTS, and they were then given equal doses of ONO-5046 or PBS three hours and 1, 2, 3, 4, 5 and 6 days later. Compared with the control groups, ONO-5046 significantly reduced proteinuria and hematuria, and suppressed the formation of crescentic glomeruli in a dose-dependent manner. Our results suggest that neutrophil elastase participates in NTS nephritis by degrading glomerular basement membrane proteins, and that the elastase inhibitor, ONO-5046, suppresses crescentic formation and glomerular injury caused by elastase.     

Progressive angiomyolipoma with inferior vena cava tumor thrombus

A 45-year-old man presented with an incidentally discovered benign renal angiomyolipoma. This lesion initially demonstrated renal vein involvement. On referral to our institution 3 years later, there was interval progression of tumor thrombus to the intrahepatic inferior vena cava. Intravascular extension of benign angiomyolipoma, though rare, has been reported. We present a new example and review the literature concerning this unusual complication of a common renal neoplasm.     

Selective neuronal targeting in prion disease

The pattern of scrapie prion protein (PrP(Sc)) accumulation in the brain is different for each prion strain. We tested whether the PrP(Sc) deposition pattern is influenced by the Asn-linked oligosaccharides of PrP(C) in transgenic mice. Deletion of the first oligosaccharide altered PrP(C) trafficking and prevented infection with two prion strains. Deletion of the second did not alter PrP(C) trafficking, permitted infection with one prion strain, and had a profound effect on the PrP(Sc) deposition pattern. Our data raise the possibility that glycosylation can modify the conformation of PrP(C). Glycosylation could affect the affinity of PrP(C) for a particular conformer of PrP(Sc), thereby determining the rate of nascent PrP(Sc) formation and the specific patterns of PrP(Sc) deposition.     

The Polyclinic at the 1996 Atlanta Olympic Village

The Polyclinic, staffed mainly by volunteers, successfully provided primary health care during 16,519 patient encounters, 64% involving athletes. However, the profile of patient needs held some surprises.     

Potential cardioembolic sources in an elderly population without stroke. A transthoracic and transoesophageal echocardiographic study in randomly selected volunteers

Transoesophageal echocardiography renders a better image than transthoracic echocardiography of cardiac changes especially at the atrial level, and of atherosclerotic changes in the aorta. Although several studies on stroke patients have included transthoracic and transoesophageal echocardiography, the relevance of the reported findings remains unclear because of limited information on the prevalence of cardiac changes related to cardioembolism in a control population without stroke. In order to define a non-hospitalized group of volunteers without previous stroke or transient ischaemic attack, we randomly selected a group of 68 volunteers (mean age 65.4 years). These volunteers were divided into two groups: the elderly group, 65 years or older (n = 38) and the younger group, younger than 65 years (n = 30). The subjects underwent transthoracic and transoesophageal echocardiography, sonography of the carotid arteries, and magnetic resonance imaging of the brain. The prevalences of atrial septal aneurysm, patent foramen ovale, mitral annulus calcification, and protruding plaque in the aorta were investigated. We found atrial septal aneurysm in 13%, patent foramen ovale in 22%, protruding plaque in the aorta in 7%, and mitral annular calcification in 22% of the 68 subjects. No significant differences were found between the two age groups with the exception of mitral annular calcification, which was seen more often in the older group (P < 0.001). Total cardiac changes related to thromboembolism (including three cases with atrial fibrillation in the older group and other less common cardiac embolic sources) were more common in the older than in the younger group (23/38 vs 9/30; P < 0.05). If mitral annular calcification was excluded, no difference was found between the elderly and the younger group, 14/38 vs 8/30; ns. Even when subjects with a history of heart disease or a pathological ECG were omitted, no differences between the two age groups were found. The causal relationship between a possible embolic source and a clinical embolic event remains unsettled. The high prevalence of cardiac changes in a control population has to be considered when evaluating the significance of similar findings in patients with stroke.     

Induction of bioactivity of a non-bioactive glass-ceramic by a chemical treatment

Glass-ceramic A-W(Al), which was prepared by heat treatment of a MgO-CaO-SiO2-P2O5-Al2O3 glass to precipitate crystalline apatite and wollastonite, shows a higher mechanical strength than glass-ceramic A-W, which was prepared by heat treatment of a MgO-CaO-SiO2-P2O5 glass to precipitate the same types of crystalline phases. The former, however, does not show bone-bonding ability, i.e. bioactivity, whereas the latter shows it. In the present study, in order to induce bioactivity of glass-ceramic A-W(Al), it was treated with HCl or NaOH solutions with different concentrations, and its bioactivity was evaluated by examining the apatite formation on its surface in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. When the glass-ceramic A-W(Al) was pretreated with HCl aqueous solutions with concentrations over 0.1 M, it formed the bone-like apatite on its surface in SBF. This was attributed to the formation of a hydrated silica on its surface by the HCl treatment.     

Relationship of visual assessments of feeder lamb muscularity to differences in carcass yield traits

We examined the relationship between visual differences in muscle thickness among feeder lambs and subsequent differences in carcass composition. Medium-framed, crossbred feeder lambs (n = 120) were selected at two commercial feedlots to exhibit distinct phenotypic differences in muscularity. The lambs were assigned scores (ranging from 1 to 9; 1 = extremely thin, 5 = average, 9 = extremely thick) for muscle thickness and were sampled serially on d 0, 14, 28, and 42 of the trial. After recording yield grades, one side of each carcass was deboned, and the soft tissues from the entire side were ground, sampled, and analyzed for lipid and moisture content. The opposite side was fabricated into boneless, closely trimmed (.25 cm maximum fat depth) subprimal cuts. When lambs of the same frame size were compared at the same live weight, greater muscle thickness was associated with greater (P < .05) fat-free muscle mass. Correspondingly, thickly muscled lambs produced carcasses of a given weight that had a higher (P < .05) composite yield of lean meat and a lower (P < .05) proportion of trimmable fat compared with carcasses of thinly muscled lambs. When comparisons were made at the same percentage of extractable fat in the carcass, greater muscle thickness was associated with heavier (P < .05) live and carcass weights, increased (P < .05) fat-free muscle mass, and increased (P < .05) weights of trimmed, boneless subprimal cuts. Results suggest that visual assessments of muscle thickness in feeder lambs, as applied in this study, are indicative of commercially important differences in carcass yields of lean meat.     

Bone registration method for robot assisted surgery: pedicle screw insertion

A registration method that identifies bone geometry with respect to a robotic manipulator arm is presented. Although the method is generally applicable to many orthopaedic internal fixation procedures, it was only demonstrated for the insertion of pedicle screws in vertebral bodies for spine fixation. The method relies upon obtaining an impression of the vertebral bodies. Computerized tomography (CT) scans of both vertebrae and mould are reconstructed using a computer aided engineering (CAE) system. From the reconstructions, the surgeon is able to do preoperative planning including selection of pedicle screw diameter, direction of screw through pedicle, point of entry and length of engagement. The three-dimensional models are than meshed to determine positions of the surgeon's preoperative plan relative to the mould. Intra-operative positions are defined in space by a mechanical fixture rigidly attached to the mould and designed to allow a manipulator end-effector to recognize the global coordinates of the in vivo spine. The theory and methodology were validated using a five-axis manipulator arm. This initial presentation assumes and allows no relative motion between vertebrae in vivo.     

Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators

BACKGROUND: Treatment of stenosis in saphenous-vein grafts after coronary-artery bypass surgery is a difficult challenge. The purpose of this study was to compare the effects of stent placement with those of balloon angioplasty on clinical and angiographic outcomes in patients with obstructive disease of saphenous-vein grafts. METHODS: A total of 220 patients with new lesions in aortocoronary-venous bypass grafts were randomly assigned to placement of Palmaz-Schatz stents or standard balloon angioplasty. Coronary angiography was performed during the index procedure and six months later. RESULTS: As compared with the patients assigned to angioplasty, those assigned to stenting had a higher rate of procedural efficacy, defined as a reduction in stenosis to less than 50 percent of the vessel diameter without a major cardiac complication (92 percent vs. 69 percent, P<0.001), but they had more frequent hemorrhagic complications (17 percent vs. 5 percent, P<0.01). Patients in the stent group had a larger mean (+/-SD) increase in luminal diameter immediately after the procedure (1.92+/-0.30 mm, as compared with 1.21+/-0.37 mm in the angioplasty group; P<0.001) and a greater mean net gain in luminal diameter at six months (0.85+/-0.96 vs. 0.54+/-0.91 mm, P=0.002). Restenosis occurred in 37 percent of the patients in the stent group and in 46 percent of the patients in the angioplasty group (P=0.24). The outcome in terms of freedom from death, myocardial infarction, repeated bypass surgery, or revascularization of the target lesion was significantly better in the stent group (73 percent vs. 58 percent, P = 0.03). CONCLUSIONS: As compared with balloon angioplasty, stenting of selected venous bypass-graft lesions resulted in superior procedural outcomes, a larger gain in luminal diameter, and a reduction in major cardiac events. However, there was no significant benefit in the rate of angiographic restenosis, which was the primary end point of the study.