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Biomedical subjects

James H Herndon

Publications and source records attributed to James H Herndon.

16 recordsLinked to original sources
PubMed2006

Adapalene gel 0.3% for the treatment of acne vulgaris: a multicenter, randomized, double-blind, controlled, phase III trial.

BACKGROUND: A new 0.3% gel formulation of adapalene has been developed. OBJECTIVE: We sought to provide evidence of the superiority of adapalene gel 0.3% over adapalene gel 0.1% and gel vehicle in the treatment of acne. METHODS: A total of 653 patients were randomized to receive adapalene gel 0.3%, adapalene gel 0.1%, or vehicle once daily for 12 weeks (2:2:1 randomization). Analysis for efficacy was conducted on correlated repeated measurements at weeks 8 and 12 using Generalized Estimating Equation methodology. RESULTS: Adapalene gel 0.3% was significantly superior to adapalene gel 0.1% and vehicle in success rate, total lesion count, and inflammatory lesion count. A consistent, dose-dependent effect was demonstrated for all efficacy measures. Signs and symptoms were mostly mild to moderate and transient in nature. LIMITATIONS: Adjunctive topical or oral agents and their impact on acne were not studied in this trial. CONCLUSIONS: Adapalene gel 0.3% was effective and well tolerated in the treatment of acne.

Acne Vulgaris↗
PubMed2006

A global optimization method for prediction of muscle forces of human musculoskeletal system.

Inverse dynamic optimization is a popular method for predicting muscle and joint reaction forces within human musculoskeletal joints. However, the traditional formulation of the optimization method does not include the joint reaction moment in the moment equilibrium equation, potentially violating the equilibrium conditions of the joint. Consequently, the predicted muscle and joint reaction forces are coordinate system-dependent. This paper presents an improved optimization method for the prediction of muscle forces and joint reaction forces. In this method, the location of the rotation center of the joint is used as an optimization variable, and the moment equilibrium equation is formulated with respect to the joint rotation center to represent an accurate moment constraint condition. The predicted muscle and joint reaction forces are independent of the joint coordinate system. The new optimization method was used to predict muscle forces of an elbow joint. The results demonstrated that the joint rotation center location varied with applied loading conditions. The predicted muscle and joint reaction forces were different from those predicted by using the traditional optimization method. The results further demonstrated that the improved optimization method converged to a minimum for the objective function that is smaller than that reached by using the traditional optimization method. Therefore, the joint rotation center location should be involved as a variable in an inverse dynamic optimization method for predicting muscle and joint reaction forces within human musculoskeletal joints.

Biomechanical Phenomena↗
PubMed2005

Gene transfer to human joints: progress toward a gene therapy of arthritis.

This article describes the clinical application of gene therapy to a nonlethal disease, rheumatoid arthritis (RA). Intraarticular transfer of IL-1 receptor antagonist (IL-1Ra) cDNA reduces disease in animal models of RA. Whether this procedure is safe and feasible in humans was addressed in a phase I clinical study involving nine postmenopausal women with advanced RA who required unilateral sialastic implant arthroplasty of the 2nd-5th metacarpophalangeal (MCP) joints. Cultures of autologous synovial fibroblasts were established and divided into two. One was transduced with a retrovirus carrying IL-1Ra cDNA; the other provided untransduced, control cells. In a dose escalation, double-blinded fashion, two MCP joints were injected with transduced cells, and two MCP joints received control cells. One week later, injected joints were resected and examined for evidence of successful gene transfer and expression by using RT-PCR, ex vivo production of IL-1Ra, in situ hybridization, and immunohistochemistry. All subjects tolerated the protocol well, without adverse events. Unlike control joints, those receiving transduced cells gave positive RT-PCR signals. Synovia that were recovered from the MCP joints of intermediate and high dose subjects produced elevated amounts of IL-1Ra (P = 0.01). Clusters of cells expressing high levels of IL-1Ra were present on synovia of transduced joints. No adverse events occurred. Thus, it is possible to transfer a potentially therapeutic gene safely to human rheumatoid joints and to obtain intraarticular, transgene expression. This conclusion justifies additional efficacy studies and encourages further development of genetic approaches to the treatment of arthritis and related disorders.

Aged↗
PubMed2005

Gene expression clustering using self-organizing maps: analysis of the macrophage response to particulate biomaterials.

The most common cause of total joint replacement failure is peri-implant bone loss causing pain and prosthesis loosening. This process, known as osteolysis or aseptic loosening, is characterized by macrophage phagocytosis of particulate implant wear debris. In an incompletely defined step, particulate biomaterial debris induces macrophages to release a variety of inflammatory mediators and signaling proteins that lead to bone loss. In an in vitro model of this process, we used microarray technology and data analysis techniques, including the use of self-organizing maps (SOMs), to understand the mRNA gene expression changes occurring in macrophages exposed to clinically relevant particles of ultra-high molecular weight polyethylene and TiAlV alloy. Earlier studies have been limited by technology that only allowed analysis of a few genes at a time, but the microarray techniques used in this paper generate the quantitative analysis of over a thousand genes simultaneously. Our microarray analysis utilized an SOM clustering to elucidate general patterns in the data, lists of top up- and down-regulated genes for each time point and genes with differential expression under different biomaterial exposures. The expression levels of the majority of genes (>95%) did not vary over time or with exposure to different biomaterials, but a few important genes, such as TNF-alpha, IL-1beta, IL-6, and MIP1alpha, proved to be highly regulated in response to biomaterial exposure. We also uncovered a novel set of genes, which not only validates and logically extends the current model of the pathogenesis of osteolysis and aseptic loosening, but also provides new targets for further research and therapeutics.

Algorithms↗
PubMed2004

Health care technology assessment. Basic principles and clinical applications.

Health care technology (defined as all drugs, devices, and medical and surgical procedures used in medical care as well as the organizational and supportive systems within which such care is provided) is widely regarded as an important driver of escalating health care spending in the United States. Many new health care technologies are adopted and used in clinical practice with little or no evidence that their use is associated with improved patient outcomes. Orthopaedic surgeons are facing increasing scrutiny from hospitals and payers regarding the adoption and use of new technology for the treatment of patients with musculoskeletal disease. Health care technology assessment is a growing field that is concerned with the multidisciplinary evaluation of clinical data on the basis of safety and efficacy as well as economic aspects of technology acquisition. Through an understanding of the relevant literature and the concepts of health care technology assessment, orthopaedic surgeons have an opportunity to participate in the assessment process and thus influence clinical and health policy decisions regarding the adoption and use of new and existing technologies in the field of orthopaedic surgery.

Delivery of Health Care↗
PubMed2002

Distal radius fractures in older women: a 10-year follow-up study of descriptive characteristics and risk factors. The study of osteoporotic fractures.

OBJECTIVES: To determine the incidence of distal radius fractures and the characteristics of those fractures and to identify the key risk factors. DESIGN: Prospective cohort study, mean follow-up of 9.8 years. SETTING: Four clinical centers, one each in Baltimore, Maryland; Minneapolis, Minnesota; Pittsburgh, Pennsylvania; and Portland, Oregon. PARTICIPANTS: Nine thousand seven hundred four white women aged 65 and older, enrolled in the multicenter Study of Osteoporotic Fractures. METHODS: Five hundred twenty-seven distal radius fractures were confirmed by physician review of radiology reports; characteristics of the fractures were noted. Information was also collected on lifestyle, demographics, bone mineral density (BMD), and clinical and performance measures. RESULTS: The overall incidence of fracture was 7.3/1,000 person-years. Twenty-seven percent of the fractures were intra-articular; 73% were extra-articular. The independent predictors of fracture were decreased BMD (per 0.1 g/cm(2)) at the distal radius ( relative risk ( RR)=1.8, 95% confidence interval ( CI)=1.6-2.1), a history of recurrent falls ( RR=1.6, 95% CI=1.2-2.0), and having had a previous fracture since age 50 ( RR=1.3, 95% CI=1.1-1.6). Current use of oral estrogen was protective ( RR=0.6, 95% CI=0.4-0.8). For women aged 75 and older, poor cognitive status was also a predictor of wrist fracture. Intra-articular fractures occurred more than twice as frequently in women with diabetes mellitus. CONCLUSIONS: This is the first large long-term comprehensive study of distal radius fractures in older people. The results indicate that factors predictive of distal radius fractures can easily be assessed in routine clinical practice and can identify women at high risk for fracture. Selected preventive strategies could be designed to reduce the incidence of these fractures.

Aged↗
PubMedDate not supplied

Gene therapy for the treatment of musculoskeletal diseases.

Research into the orthopaedic applications of gene therapy has resulted in progress toward managing chronic and acute genetic and nongenetic disorders. Gene therapy for arthritis, the original focus of research, has progressed to the initiation of several phase I clinical trials. Preliminary findings support the application of gene therapy in the treatment of additional chronic conditions, including osteoporosis and aseptic loosening, as well as musculoskeletal tumors. The most rapid progress is likely to be in tissue repair because it requires neither long-term transgene expression nor closely regulated levels of transgene expression. Moreover, healing probably can be achieved with existing technology. In preclinical studies, genetically modulated stimulation of bone healing has shown impressive results in repairing segmental defects in the long bones and cranium and in improving the success of spinal fusions. An increasing amount of evidence indicates that gene transfer can aid the repair of articular cartilage, menisci, intervertebral disks, ligaments, and tendons. These developments have the potential to transform many areas of musculoskeletal care, leading to treatments that are less invasive, more effective, and less expensive than existing modalities.

Arthritis, Rheumatoid↗