Adverse reactions to an absorbable shoulder fixation device

Bioabsorbable implants have been advocated for use in repair of a torn glenoid labrum to correct shoulder instability. These implants have been thought to be safe and to have little toxicity, antigenicity, or adverse side effects. However, similar implants have been shown to cause nonspecific granulomatous reactions when implanted into bone or soft tissues in studies in both animals and human beings. This article reports the adverse effects of these implants in six shoulders of five patients who had repair of a damaged glenoid labrum. All patients reported increasing pain and loss of shoulder motion after insertion of these devices. All required a further arthroscopic lavage and debridement to reduce the inlracapsular synovitis. Granulomatous reactions were identified histologically in all cases. No long-term side effects were encountered, and all patients recovered satisfactorily.     

Population health promotion: responsible sharing of future directions

Population health promotion illustrates most robustly that health is a shared responsibility. Improving our understanding of the social production of health and the purchase population health promotion has on shaping social welfare policy presents a number of challenges to the future development of this discourse. Three are briefly discussed in this paper. First is the matter of language we use to describe our understanding of processes and influences. Second is the conceptualization of the pathways that shape population health status. Finally, cultural practices both extant and required to improve health status and reduce inequalities are addressed.     

Hamstring tendon grafts for reconstruction of the anterior cruciate ligament: biomechanical evaluation of the use of multiple strands and tensioning techniques

BACKGROUND: Our hypothesis that multiple, equally tensioned strands of hamstring graft used for reconstruction of the anterior cruciate ligament are stronger and stiffer than ten-millimeter patellar ligament grafts was tested biomechanically with use of tendons from cadavera. METHODS: In the first part of the study, we measured the strength and stiffness of one, two, and four-strand hamstring grafts, from fresh-frozen cadaveric knees, that had been tensioned equally when clamped. In the second part of the study, we compared four-strand grafts to which tension had been applied by hand and then clamped with similar grafts to which tension had been applied with weights and then clamped. The grafts for the two experiments were obtained from thirty-four paired and ten unpaired knees. We also studied the effects of cooling on the biomechanical properties of grafts by comparing patellar ligament grafts tested at 13 degrees Celsius with those tested at room temperature. RESULTS: Two equally tensioned gracilis strands had 185 percent of the strength and 210 percent of the stiffness (1550+/-428 newtons and 336+/-141 newtons per millimeter, respectively) of one gracilis strand (837+/- 138 newtons and 160+/-44 newtons per millimeter, respectively). Two equally tensioned semitendinosus strands had 220 percent of the strength and 220 percent of the stiffness (2330+/-452 newtons and 469+/-185 newtons per millimeter, respectively) of one semitendinosus strand (1060+/-227 newtons and 213+/-44 newtons per millimeter, respectively). Four combined strands (two gracilis strands and two semitendinosus strands) that were equally tensioned with weights and clamped had the additive tensile properties of the individual strands. With the numbers available, four combined strands that were manually tensioned and clamped were not found to be significantly stronger or stiffer than two semitendinosus strands that were equally tensioned with weights (p>0.07). CONCLUSIONS: Four combined strands that were equally tensioned with weights and clamped were stronger and stiffer than all ten-millimeter patellar ligament grafts that have been described in previous reports. All strands of a hamstring graft must be equally tensioned for the composite to have its optimum biomechanical properties. CLINICAL RELEVANCE: Because of the well recognized donor-site morbidity associated with the use of patellar ligament grafts for reconstruction of the anterior cruciate ligament, multiple-strand hamstring-tendon grafts have become an increasingly popular choice. Our data demonstrate that equally tensioned four-strand hamstring-tendon grafts have initial tensile properties that are higher than those reported for ten-millimeter patellar-ligament grafts; thus, from a biomechanical point of view, they seem to be a reasonable alternative.     

Metabolism and excretion of atorvastatin in rats and dogs.

Atorvastatin (AT) is a second-generation potent inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase, clinically approved for lowering plasma cholesterol. Using a mixture of [D(5)/D(0)] AT and/or [(14)C]AT, the metabolic fate and excretion of AT were examined in rats and dogs following single and multiple oral doses. Limited biliary recycling was examined in one dog after a single dose of AT. AT-derived metabolites in bile samples were identified by metabolite screening of the [D(5)/D(0)] AT molecular clusters using tandem mass spectrometry. Bile was a major route of [(14)C] drug-derived excretion, accounting for 73 and 33% of the oral dose in the rat and dog, respectively. The remaining radioactivity was recovered in the feces; only trace amounts were excreted in urine. Radioactive components identified in rat and dog bile were the para- and ortho-hydroxy metabolites, a glucuronide conjugate of ortho-hydroxy AT, and unchanged AT. Two minor radioactive components were identified as beta-oxidation products of AT with one confirmed as a beta-oxidized AT derivative. The reappearance of AT and major metabolites in bile from a dog administered a sample of its previously excreted bile indicated biliary recycling is an important component in AT metabolism. Multiple dose administration in rats did not alter biliary metabolic profiles. Rat and dog plasma profiles after multiple dose administration were similar and showed no additional metabolites not found in bile. Examination of rat and dog bile and plasma indicates that AT primarily undergoes oxidative metabolism.     

Efficacy of the topical skin protectant in advanced development

A topical skin protectant (TSP) (ICD 2289) is being developed to protect service members from exposure to chemical warfare agents (CWA). The TSP is designed for use on the skin at the overgarment closures and other vulnerable areas to enhance protection. The TSP, which is in phase II clinical studies, is a cream containing two chemically inert substances: perfluoroalkylpolyether and polytetrafluoroethylene. Animal data showed that the TSP was effective against percutaneous penetration of a blister agent, sulfur mustard (HD), by reducing the size of skin lesions and against T-2 mycotoxin by preventing the development of erythema and edema. The insect repellent N,N-diethyl-m-toluamide (DEET) reduced the TSP protection against HD regardless of the order of application on rabbit skin prior to dosing of HD. The protection was sustained when DEET was removed with a dry gauze prior to TSP application. The TSP was also effective against percutaneous exposure of nerve agents-thickened (with 5% methyl methacrylamide) soman (TGD) and VX (O-ethyl-S-[2-(diisopropylamino)ethyl]methylphosphonothioate )-by reducing the mortality rate and protecting the red blood cell acetylcholinesterase activity. The TSP was effective against VX when DEET was applied prior to TSP application. Because human efficacy studies using CWA cannot be conducted, the efficacy will be demonstrated by the level of protection against poison ivy (urushiol) contact dermatitis in humans.     

Reliability of labial closure force measurements in normal subjects and patients with CNS disorders.

This study determined the reliability of maximal upper and lower lip closing forces measured using a strain-gauged cantilever beam assembly. An intraclass correlation approach was used to explicitly partition the "error free" between-subject variance and measurement error variance across repeated days (2) and across repeated trials (5). Ten healthy adults served as controls and 30 patients with diagnoses of multiple sclerosis, cerebrovascular accident, or Parkinson's disease served as subjects. The intraclass correlation analyses revealed generally high reliability (R greater than .90) for upper and lower lip force measurements, for various combinations of control and/or patient groups, and within each individual patient group. There was moderate correspondence between the quantitative measures of lip force and the clinical assessment of combined upper (r = .67) and lower lip closure force (r = .62) but low correspondence between the quantitative measures of lip force and the presence of motor speech deficit. The lower lip force of patients with Parkinson's disease (M = 3.1 N) on Day 1 was markedly reduced from that of all other patient groups and controls (M = 10.1 N). These results yield helpful information for the design of investigations of oral-motor weakness and for the quantitative assessment of an individual's clinical status.