Tissue engineered vascular grafts transform into autologous neovessels capable of native function and growth.

Background: Tissue-engineered vascular grafts (TEVGs) have the potential to advance the surgical management of infants and children requiring congenital heart surgery by creating functional vascular conduits with growth capacity.

Methods: Herein, we used an integrative computational-experimental approach to elucidate the natural history of neovessel formation in a large animal preclinical model; combining an in vitro accelerated degradation study with mechanical testing, large animal implantation studies with in vivo imaging and histology, and data-informed computational growth and remodeling models.

Results: Our findings demonstrate that the structural integrity of the polymeric scaffold is lost over the first 26 weeks in vivo, while polymeric fragments persist for up to 52 weeks.

Volar fixation of dorsally displaced distal radius fractures using the 2.4-mm locking compression plates.

Purpose: To determine whether volar fixed-angle plate fixation with a new plate system could be used to treat dorsally unstable distal radius fractures. We hypothesized that volar fixed-angle plate fixation with or without radial styloid fixed-angle plate fixation would provide sufficient rigidity to allow early active range of motion without compromising fracture reduction. The initiation of early active motion may improve functional outcomes.

Expression of a beta-defensin mRNA, lingual antimicrobial peptide, in bovine mammary epithelial tissue is induced by mastitis.

The expression of a beta-defensin, the lingual antimicrobial peptide (LAP), in response to mastitis was investigated by real-time PCR of RNA from mastitic and control udder quarters. There was a positive relationship between somatic cell count in milk and LAP expression. In situ hybridization showed that LAP mRNA was expressed in epithelial cells of mastitic tissue.

Does Medicare managed care provide equal treatment for mental illness across races?

Background: While disparities in access to care are well documented, little is known about the quality of mental health care received by racial and ethnic minorities. We examined the quality of mental health care received by elderly enrollees in Medicare + Choice plans.

Methods: An observational study was performed using individual-level Health Plan Employer Data and Information Set data.

Racial variation in the control of diabetes among elderly medicare managed care beneficiaries.

Objective: To examine racial variation in the poor control of GHb, a GHb value >9.5%, or GHb not tested in 1999 among Medicare beneficiaries aged 65-75 years enrolled in managed care plans.

Research Design And Methods: The National Committee on Quality Assurance provides person-level data regarding diabetes care services and control for Medicare beneficiaries enrolled in managed care to the Centers for Medicare and Medicaid Services (CMS).

Molecular differentiation of clostridia associated with "blown pack" spoilage of vacuum-packed meats using internal transcribed spacer polymorphism analysis.

The 16S-23S rDNA internal transcribed spacer (ITS) polymorphism analysis was assessed for its suitability in rapid discrimination between species of psychrophilic and psychrotolerant clostridia associated with "blown pack" spoilage of vacuum-packed meats. DNA isolated from 10 reference and 20 meat strains of psychrophilic and psychrotolerant clostridia were used as templates in PCR amplification with primers complementary to conserved regions of the 3' end of the 16S rRNA and 5' end of the 23S rRNA genes directly flanking the spacer. The majority of strains showed multi-band ITS patterns when products of spacer amplification were visualised on an agarose gel.

Archaeal genome organization and stress responses: implications for the origin and evolution of cellular life.

For DNA to be used as an informational molecule it must exist in the cell on the edge of stability because all genomic processes require local controlled melting. This presents mechanistic opportunities and problems for genomic DNA from hyperthermophilic organisms, whose unpackaged DNA could melt at optimal temperatures for growth. Hyperthermophiles are suggested to employ the novel positively supercoiling topoisomerase enzyme reverse gyrase (RG) to form positively supercoiled DNA that is intrinsically resistant to thermal denaturation.

Pediatric orthopedic trauma: principles in management.

Optimal management of pediatric orthopedic trauma requires understanding the unique characteristics of the immature musculoskeletal system. The principles of pediatric orthopedic trauma management include anticipating future growth and bone remodeling potential, minimizing physeal injury, and aggressive treatment of open fractures and compartment syndromes. This article discusses the fundamentals of the pediatric musculoskeletal system and pediatric orthopedic trauma management in general and as they apply to specific injuries.

Racial variation in quality of care among Medicare+Choice enrollees.

This paper examines racial variation in quality of and access to care experienced by elderly persons enrolled in Medicare+Choice plans. We used eight individual-level Health Plan Employer Data and Information Set (HEDIS) measures to compare whites with blacks, Asians, Hispanics, and Native Americans. Across all measures, black enrollees received lower-quality care.

The abattoir source of culturable psychrophilic Clostridium spp. causing 'blown pack' spoilage of vacuum-packed chilled venison.

Aims: To identify the abattoir source(s) of culturable psychrophilic clostridia causing 'blown pack' spoilage of vacuum-packed chilled meats.

Methods And Results: Psychrophilic and psychrotolerant clostridia were isolated from hides, faeces and tonsils of deer slaughter stock, and from a meat plant environment. The isolates were differentiated using restriction fragment length polymorphism analysis of the 16S rDNA gene (PCR-RFLP) and 16S-23S rDNA internal transcribed spacer (ITS) analysis.

Muscle-based gene therapy and tissue engineering for treatment of growth plate injuries.

Growth plate injuries may lead to a progressive angular deformity or longitudinal growth disturbance. The authors investigated the feasibility of gene therapy and tissue engineering based on autologous muscle-and adenoviral-mediated gene transfer of insulin-like growth factor-1 (IGF-1) and bone morphogenetic protein-2 (BMP-2) to treat tibial physeal defects in rabbits. The medial half of the left proximal tibial growth plate was completely excised in 44 6-week-old New Zealand white rabbits.

Enhancement of bone healing based on ex vivo gene therapy using human muscle-derived cells expressing bone morphogenetic protein 2.

Molecular biological advances have allowed the use of gene therapy in a clinical setting. In addition, numerous reports have indicated the existence of inducible osteoprogenitor cells in skeletal muscle. Because of this, we hypothesized that skeletal muscle cells might be ideal vehicles for delivery of bone-inductive factors.

Human skeletal muscle cells in ex vivo gene therapy to deliver bone morphogenetic protein-2.

We have examined whether primary human muscle-derived cells can be used in ex vivo gene therapy to deliver BMP-2 and to produce bone in vivo. Two in vitro experiments and one in vivo experiment were used to determine the osteocompetence and BMP-2 secretion capacity of cells isolated from human skeletal muscle. We isolated five different populations of primary muscle cells from human skeletal muscle in three patients.

Gene therapy and tissue engineering in orthopaedic surgery.

A new biologic era of orthopaedic surgery has been initiated by basic scientific advances that have resulted in the development of gene therapy and tissue engineering approaches for treating musculoskeletal disorders. The terminology, fundamental concepts, and current research in this burgeoning field must be understood by practicing orthopaedic surgeons. Different gene therapy approaches, multiple gene vectors, a multitude of cytokines, a growing list of potential scaffolds, and putative stem cells are being studied.

Minimal medial epicondylectomy and decompression for cubital tunnel syndrome.

Sixty-four patients (66 elbows) treated for refractory cubital tunnel syndrome had minimal medial epicondylectomy and in situ decompression to minimize the potential disadvantages of classic medial epicondylectomy. After a mean followup of 27 months results were excellent in 27 patients (44%), good in 23 patients (35%), fair in 10 patients (15%), and poor in four patients (6%). No ulnar nerve palsy, ulnar nerve subluxation, or medial elbow instability were seen.

Partial rupture of the distal biceps tendon.

We report on 7 cases of partial rupture of the distal biceps tendon. The mean patient age was 52 years (range, 38-58 years). There were 5 men and 2 women.

Back problems among postmenopausal women taking estrogen replacement therapy: the study of osteoporotic fractures.

Study Design: Cross-sectional and prospective.

Objectives: To investigate the association between estrogen replacement therapy use, back pain, and back function in a large cohort of elderly women.

Background: Several studies have suggested that women who use estrogen replacement therapy may be more likely to experience back pain than those who do not.

Effect of bone morphogenetic protein-2-expressing muscle-derived cells on healing of critical-sized bone defects in mice.

Background: Cells that express bone morphogenetic protein-2 (BMP-2) can now be prepared by transduction with adenovirus containing BMP-2 cDNA. Skeletal muscle tissue contains cells that differentiate into osteoblasts on stimulation with BMP-2. The objectives of this study were to prepare BMP-2-expressing muscle-derived cells by transduction of these cells with an adenovirus containing BMP-2 cDNA and to determine whether the BMP-2-expressing muscle-derived cells would elicit the healing of critical-sized bone defects in mice.

The effect of bone morphogenetic protein-2 expression on the early fate of skeletal muscle-derived cells.

The identification of bone morphogenetic proteins (BMPs) has stimulated intense interest in BMP delivery approaches. Ex vivo BMP-2 gene delivery has recently been described using skeletal muscle-derived cells. Skeletal muscle-derived cells, because of proven efficient transgene delivery and osteocompetence, represent an attractive cell population on which to base ex vivo BMP-2 gene delivery.

Diagnosis and management of acute fracture-dislocation of the carpus.

Acute fracture-dislocations of the carpus are uncommon. If treated inadequately, however, these injuries can lead to wrist pain and dysfunction as a result of progressive traumatic arthritis. Accurate diagnosis and early intervention are essential for optimal recovery.

SLAP lesions: current concepts.

The presence and significance of superior glenoid labral tears have received increasing attention in the 1990s. The symptoms associated with labral tears can be quite disabling to competitive and recreational athletes alike. Recent basic science and clinical studies have contributed much to the understanding of these injuries, including their association with suprascapular nerve entrapment.

Osteoprogenitor cells within skeletal muscle.

The formation of ectopic bone within skeletal muscle is a widely observed phenomenon. However, the source of the osteoprogenitor cells responsible for ectopic bone formation remains unknown. This study was designed to test for osteogenic differentiation among cells isolated from skeletal muscle tissue.

The efficiency of muscle-derived cell-mediated bone formation.

The development of new clinically applicable methods for the delivery of bone morphogenic protein (BMP) is an area of intensive research. Cell-mediated gene therapy approaches are being explored as a potential delivery vehicle. Primary muscle-derived cells isolated from an adult mouse were transduced with an adenoviral-BMP-2 construct.

Validity of photoelastic strain measurement on cadaveric proximal femora.

Rosette strain gages indicate shear and principal strains at specific points, whereas photoelastic coatings provide shear strain information over a broad area. Information regarding bone loading and load transfer from a prosthetic implant to adjacent bone can be obtained using either strain-measuring technique on loaded femora. This study compared proximal femoral strains derived from photoelastic coatings to those obtained from rosette strain gages applied directly to the bone in order to determine the relationships between photoelastic shear strains and rosette shear and principal strains.