Clinical and radiological outcomes of concomitant endoscopic gastrocnemius release with scarf osteotomy

Background

Studies showed patients with hallux valgus also have tight gastrocnemius concomitantly. This study aims to investigate (1) prevalence of tight gastrocnemius in symptomatic hallux valgus (2) clinical and radiological outcomes of concomitant endoscopic gastrocnemius release with scarf osteotomy.

Radiological and clinical outcome of selective thoracic fusion for patients with Lenke 1C and 2C adolescent idiopathic scoliosis with a minimum follow-up of 2 years

Background Context

In Lenke 1C and 2C curves, the choice between selective thoracic fusion (STF) versus non-selective thoracic fusion as the optimal surgical treatment is controversial.

Microvascular cell death in spontaneously hypertensive rats during experimental inflammation

OBJECTIVE: Chronic hypertension is associated with an increased risk for tissue injury that may be mediated in part by endothelium and inflammatory cells. To clarify a possible underlying mechanisms, we examined leukocyte migration in the microcirculation and concomitant parenchymal cell death. METHODS: The mesentery of spontaneously hypertensive rats (SHRs) and their normotensive controls, Wistar Kyoto (WKY) rats, was examined with digital fluorescence microscopy after topical stimulation with an inflammatory mediator (f-met-leu-phe, 10(-8)M). The migratory pathways of individual leukocytes were traced, and at the same time cell death was detected by use of a life-death indicator (propidium iodide) over a period of 3 hours. RESULTS: Both WKY and SHR had a progressively increasing number of leukocytes migrating across the endothelium in postcapillary venules into the tissue parenchyma. But parenchymal cell death was detected in a random pattern in the mesentery tissue, without correlation to the migratory positions of the leukocytes. Although mature SHR rats (about 17 weeks) exhibited the same level of cell death as age-matched WKY rats, older WKY rats (about 30 weeks) had significantly lower levels of cell death, whereas the SHR rats maintained the same number of parenchymal cell death as mature animals. CONCLUSIONS: These results suggest that in the presence of an inflammatory mediator, the SHR may exhibit a stronger response to an inflammatory mediator than normotensive WKY rats in a fashion that is age, but not blood pressure, dependent. Parenchymal cell death does not correlate with migration of activated leukocytes at the microvascular level.     

The advanced age deceased kidney donor: current outcomes and future opportunities

BaCKGROUND: Due to the aging general population, deceased donors > or =55 years will form an increasingly larger proportion of the deceased kidney donor pool. METHODS: Using data from the United States Renal Data System, we determined the change in graft survival between 1996 and 2000 among 32,557 recipients of donors aged <55 years and > or =55 years in univariate and multivariate survival analyses. We identified donor risk factors for graft loss that might influence the decision to accept or reject donors <55 and > or =55 years. The initial glomerular filtration rate established 6 months after transplantation (initial GFR), and the stability of GFR in the first post-transplant year (GFR at 12 months post-transplantation-GFR at six months post-transplantation) were compared between recipients of donors <55 and > or =55 years and the association of these factors with graft survival was determined. RESULTS: In 2000, one-year graft survival in donors > or =55 years was 86.7%. Between 1996 and 1999 the projected graft half life improved from 11.4 to 14.5 years for recipients of donors <55 years (P < 0.01); however, there was no improvement for recipients of donors > or =55 years (8.2 to 9.2 year, P= 0.46). Among donor factors studied, only cold ischemic time >24 hours identified recipients of donors > or =55 years at risk for graft loss. Compared to recipients of donors <55 years, recipients of donors > or =55 years established a lower initial GFR (42 vs. 56 mL/min/1.73 m(2), P < 0.0001), and had less stable GFR in the first post-transplant year (-1.5 vs. -0.6 mL/min/1.73 m(2), P <.0001). Recipients from donors > or =55 years with initial GFR > or =50 mL/min/1.73 m(2) and no drop GFR during the first post-transplant year had graft survival that was superior to that of donors <55 years with either initial GFR <50 mL/min/1.73 m(2) or a drop in GFR during the first post-transplant year. CONCLUSION: Donors > or =55 years are a valuable resource. Despite improvements in immunosuppression, rejection, and delayed graft function, the projected increase in long-term graft survival among recipients of donors <55 years was not shared among recipients of donors > or =55 years. Recipients of donors > or =55 years had lower initial GFR, and less stable GFR during the first post-transplant year. Limiting cold ischemic time to <24 hours may improve outcomes among recipients of donors > or =55 years. Future studies to maximize initial GFR and minimize early loss of GFR in recipients of donors > or =55 years may lead to improved outcomes from deceased donors > or =55 years.     

Porcine carotid arterial material property alterations with induced atheroma: an in vivo study

OBJECTIVE: A novel methodology has been developed to evaluate regional alterations in arterial wall material properties with induced atheroma in an animal model. METHODS: Atheromatous lesions (fatty, fibro-fatty, and fibrous) were induced in the carotid arteries of a Yucatan miniswine model by endothelial cell denudation and high cholesterol diet. The images at base line and 8 weeks after denudation were obtained using intravascular ultrasound (IVUS) imaging along with hemodynamic data. Finite element analysis (FEA) along with optimization was employed to assess regional alterations in elastic modulus in the presence of atheroma confirmed by histology. RESULTS: In animals with 8 weeks of induced atherosclerosis, the elastic modulus increased-(elastic modulus-all values x 10(4) Pa, mean+/-S.D.) normal elements (9.34+/-0.36) compared to abnormal elements (9.52+/-0.36) (p<0.05 versus normal elements). Wall thickness increased with atheroma formation. These data demonstrate stiffening vascular wall elastic modulus with lesion progression. This is different from the behavior of femoral arteries, where the elastic modulus decreases with early stages of atheroma development followed by an increase as lesions progress. CONCLUSIONS: This methodology permits determination of areas with early atheroma development, follow atheroma progression, and potentially evaluate interventions aimed at decreasing atheroma load and normalizing vascular material properties.     

Gas‐Phase Assisted Surface Polymerization of Vinyl Monomers with Fe‐Based Initiating Systems

Summary: Gas‐phase assisted surface polymerization (GASP) of methyl methacrylate (MMA) and styrene (St) was investigated with Fe‐based radical initiating systems, FeCl₂/2,2′‐bipyridine (Bpy)/methyl α‐bromophenylacetate (MBPA), etc. GASP with these initiating systems proceeded to produce corresponding polymers on substrate surfaces. The resulting PMMA had very high PDI values, suggesting an uncontrolled reaction. In an attempt to control the GASP, polymerization with a simple initiating system, Fe(0)/MBPA, was examined on Fe(0)‐metal surfaces, resulting in significant polymerization activity to produce high‐molecular‐weight PMMA. The results of time‐course tests on GASP of MMA and St suggested that a change had taken place to produce physically controlled propagation sites on the Fe(0) powder surfaces.

GASP schemes with a simple initiating system Fe(0)/MBPA.     

Inhibition of erythropoietin activity by cyanate

OBJECTIVE: Increased urea concentration is a measure of advanced renal failure and the adequacy of renal replacement therapy in end-stage renal disease (ESRD). Altered biologic activity due to changes in protein structure occurs when cyanate, formed spontaneously from urea, reacts with proteins. Carbamylation results in impaired erythropoietin (EPO) activity when high concentrations of cyanate react with EPO. In this study, the activity of carbamylated EPO (C-EPO), formed at a cyanate concentration which may occur in vivo, was studied in Sprague-Dawley rats. MATERIAL AND METHODS: The extent of carbamylation, causing loss of free amino groups, was monitored using trinitrobenzenesulfonic acid. Erythrocyte, hemoglobin, hematocrit and leukocyte levels were measured after either EPO, incubated EPO, C-EPO, physiologic saline or cyanate (1.5 microM; 0.2 ml) were injected subcutaneous twice weekly for 3 weeks in rats. RESULTS: In vitro carbamylation of EPO was time- and concentration-dependent. C-EPO concentration increased as the duration of exposure to cyanate increased from 6 to 72 h, or as cyanate concentration increased from 15 nM to 1.5 microM. Injections of EPO caused significant increases in vivo in all erythropoietic measures. In contrast, injections of C-EPO, physiologic saline or 1.5 microM cyanate caused no change from baseline. CONCLUSIONS: These results demonstrated diminished biologic activity in healthy rats by C-EPO formed in vitro at cyanate concentrations that may be found in vivo. C-EPO and high urea-derived cyanate levels may contribute to suboptimal erythropoietic responses to EPO therapy for chronic renal failure and ESRD, and may provide another measurement indicating inadequate dialysis.