Dynamic compression can inhibit chondrogenesis of mesenchymal stem cells.

The objective of this study was to investigate the influence of dynamic compressive loading on chondrogenesis of mesenchymal stem cells (MSCs) in the presence of TGF-beta3. Isolated porcine MSCs were suspended in 2% agarose and subjected to intermittent dynamic compression (10% strain) for a period of 42 days in a dynamic compression bioreactor. After 42 days in culture, the free-swelling specimens exhibited more intense alcian blue staining for proteoglycans, while immunohistochemical analysis revealed increased collagen type II immunoreactivity.

A comparative study of shear stresses in collagen-glycosaminoglycan and calcium phosphate scaffolds in bone tissue-engineering bioreactors.

The increasing demand for bone grafts, combined with their limited availability and potential risks, has led to much new research in bone tissue engineering. Current strategies of bone tissue engineering commonly use cell-seeded scaffolds and flow perfusion bioreactors to stimulate the cells to produce bone tissue suitable for implantation into the patient's body. The aim of this study was to quantify and compare the wall shear stresses in two bone tissue engineering scaffold types (collagen-glycosaminoglycan (CG) and calcium phosphate) exposed to fluid flow in a perfusion bioreactor.

Brain morphometry volume in autistic spectrum disorder: a magnetic resonance imaging study of adults.

Background: Several prior reports have found that some young children with autism spectrum disorder [ASD; including autism and Asperger's syndrome and pervasive developmental disorder - not otherwise specified (PDD-NOS)] have a significant increase in head size and brain weight. However, the findings from older children and adults with ASD are inconsistent. This may reflect the relatively small sample sizes that were studied, clinical heterogeneity, or age-related brain differences.

Osteoblast activity on collagen-GAG scaffolds is affected by collagen and GAG concentrations.

Optimization of a tissue engineering scaffold for use in bone tissue engineering requires control of many factors such as pore size, porosity, permeability and, as this study shows, the composition of the matrix. The collagen-glycosaminoglycan (GAG) scaffold variants were fabricated by varying the collagen and GAG content of the scaffold. Scaffolds were seeded with MC3T3 osteoblasts and cultured for up to 7 days.

Biomechanics and mechanobiology in osteochondral tissues.

Osteochondral tissues are those that form the synovial joints, namely cartilage and bone, including sub-chondral bone. The biomechanical purpose of synovial joints is to provide lubricated contact between the moving surfaces with as little frictional forces as possible. This is achieved by separating the cartilage layers by a thin film of fluid and supporting the cartilage layers by a bony trabecular network that becomes dense and more calcified immediately underneath the cartilage layer.

Follicular development induced by recombinant luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in anovulatory women with LH and FSH deficiency: evidence of a threshold effect.

Objective: To assess the requirement for luteinizing hormone (LH) in women deficient in LH and follicle-stimulating hormone (FSH).

Research Design And Methods: A prospective, randomized, parallel-group, multicentre study was carried out in tertiary care and academic medical centres. Women with anovulatory amenorrhoea > or = 1 year, serum oestradiol (E(2)) < 60 pg/mL (< 220 pmol/L) and low normal serum gonadotrophins were randomized in cycle A to a fixed daily dose of recombinant human (r-h) FSH (150 IU) and r-hLH 0, 25, 75 or 225 IU.

The effects of increased intracortical remodeling on microcrack behaviour in compact bone.

The behaviour of microdamage in bone is related to its microstructural features and thus has an important role in tissue structural properties. However, it is not known how cracks behave in areas of increased intracortical remodeling. More remodeling creates wider variation in the properties of the primary microstructural features of cortical bone, namely osteons.

Commensal-induced regulatory T cells mediate protection against pathogen-stimulated NF-kappaB activation.

Host defence against infection requires a range of innate and adaptive immune responses that may lead to tissue damage. Such immune-mediated pathologies can be controlled with appropriate T regulatory (Treg) activity. The aim of the present study was to determine the influence of gut microbiota composition on Treg cellular activity and NF-kappaB activation associated with infection.

Genetic lineages of community-associated methicillin-resistant Staphylococcus aureus in Kuwait hospitals.

Twenty-six community-associated methicillin-resistant Staphylococcus aureus (CAMSRA) isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) and screened for accessory gene regulator (agr), capsular polysaccharide (cap), and Panton-Valentine leucocidin (PVL) genes. They exhibited five PFGE patterns (types A to E). The majority were PFGE type A (12 isolates) or type B (8 isolates).

Heterogeneous linear elastic trabecular bone modelling using micro-CT attenuation data and experimentally measured heterogeneous tissue properties.

High-resolution voxel-based finite element software, such as FEEBE developed at the NCBES, is widely used for studying trabecular bone at the micro-scale. A new approach to determine heterogeneous bone tissue material properties for computational models was proposed in this study. The specimen-specific range of tissue moduli across strut width was determined from nanoindentation testing.

Gene expression by marrow stromal cells in a porous collagen-glycosaminoglycan scaffold is affected by pore size and mechanical stimulation.

Marrow stromal cell (MSC) populations, which are a potential source of undifferentiated mesenchymal cells, and culture scaffolds that mimic natural extracellular matrix are attractive options for orthopaedic tissue engineering. A type I collagen-glycosaminoglycan (CG) scaffold that has previously been used clinically for skin regeneration was recently shown to support expression of bone-associated proteins and mineralisation by MSCs cultured in the presence of osteogenic supplements. Here we follow RNA markers of osteogenic differentiation in this scaffold.

Impressions of nursing before exposure to the field.

Aims And Objectives: This paper reports on non-mature general nursing students' perceptions of nursing as a career prior to their first clinical placement.

Background: It is widely recognised that the first clinical practice experience serves a dual role, that of validating students' choice of career and shaping their perceptions of nursing. This study sought to explore 23 first year non-mature (<23 years) nursing students' perceptions of nursing as a career prior to their first clinical exposure.

Recombinant LH (lutropin alfa) for the treatment of hypogonadotrophic women with profound LH deficiency: a randomized, double-blind, placebo-controlled, proof-of-efficacy study.

Objective: To confirm the safety and efficacy of 75 IU lutropin alfa with concomitant follitropin alfa in inducing follicular development in women with profound gonadotrophin deficiency.

Design: Double-blind, randomized, placebo-controlled trial conducted in 25 medical centres in four countries.

Patients: Thirty-nine patients with LH < 1.

Mechanical stimulation of osteoblasts using steady and dynamic fluid flow.

In bone tissue engineering, flow perfusion bioreactors have shown great potential for accelerated production of functional constructs, but bioreactor culture conditions have not been optimized. The goal of this study was to investigate the short-term (1- 49 h) effects of intermittent steady, pulsatile, and oscillatory fluid flow (peak flow rate = 1.0 mL/min) on MC3T3-E1 osteoblast activity within a collagen-glycosaminoglycan scaffold.

The effect of dehydrothermal treatment on the mechanical and structural properties of collagen-GAG scaffolds.

The mechanical properties of tissue engineering scaffolds are critical for preserving the structural integrity and functionality during both in vivo implantation and long-term performance. In addition, the mechanical and structural properties of the scaffold can direct cellular activity within a tissue-engineered construct. In this context, the aim of this study was to investigate the effects of dehydrothermal (DHT) treatment on the mechanical and structural properties of collagen-glycosaminoglycan (CG) scaffolds.

The behaviour of fatigue-induced microdamage in compact bone samples from control and ovariectomised sheep.

This study investigates the effect of microdamage on bone quality in osteoporosis using an ovariectomised (OVX) sheep model of osteoporosis. Thirty-four sheep were divided into an OVX group (n=16) and a control group (n=18). Fluorochromes were administered intravenously at 3 monthly intervals after surgery to label bone turnover.

Development of a collagen calcium-phosphate scaffold as a novel bone graft substitute.

Previous investigations have shown that collagen shows excellent biological performance as a scaffold for tissue engineering. As a primary constituent of bone and cartilage, it demonstrates excellent cell adhesion and proliferation. However, in bone tissue engineering, it has insufficient mechanical properties for implantation in a load-bearing defect.

Effects of iron oxide incorporation for long term cell tracking on MSC differentiation in vitro and in vivo.

Successful cell therapy will depend on the ability to monitor transplanted cells. With cell labeling, it is important to demonstrate efficient long term labeling without deleterious effects on cell phenotype and differentiation capacity. We demonstrate long term (7 weeks) retention of superparamagnetic iron oxide particles (SPIO) by mesenchymal stem cells (MSCs) in vivo, detectable by MRI.

Design and validation of a dynamic flow perfusion bioreactor for use with compliant tissue engineering scaffolds.

In tissue engineering, flow perfusion bioreactors can be used to enhance nutrient diffusion while mechanically stimulating cells to increase matrix production. The goal of this study was to design and validate a dynamic flow perfusion bioreactor for use with compliant scaffolds. Using a non-permanent staining technique, scaffold perfusion was verified for flow rates of 0.

An evaluation of an attendance monitoring system for undergraduate nursing students.

Internationally the preparation and ongoing education of nurses continues to evolve in response the changing nature of both nursing and health care. The move into third level structures that has taken place in countries such as the UK and the Republic of Ireland, results in new challenges to the historical fabric of nurse education. One such challenge is monitoring of nursing students' attendance.

Choosing nursing as a career: a qualitative study.

It is widely accepted that nursing as a career is viewed favourably by society in that it offers job security, mobility and career variety. The main reason for choosing nursing in the 21st century remains the desire to help and care for others, as this paper demonstrates. The findings presented here are part of an on-going longitudinal study which is exploring whether mode of selection into nursing has an impact on a number of variables, of which, career choice is one.

Recombinant human luteinizing hormone, lutropin alfa, for the induction of follicular development and pregnancy in profoundly gonadotrophin-deficient women.

Objective: To provide evidence of efficacy and safety for use of lutropin alfa in inducing follicular development and pregnancy in hypogonadotrophic hypogonadal women with profound gonadotrophin deficiency.

Design: An open-label, noncomparative extension of a randomized, double-blind, placebo-controlled study

Patients: A total of 31 hypogonadotrophic hypogonadal women with profound gonadotrophin deficiency in 23 medical centres in four countries were studied.

Interventions: Lutropin alfa 75 IU and follitropin alfa (75-225 IU), individually based on each patient's response as is consistent with usual medical practice.

Controlling a multicenter outbreak involving the New York/Japan methicillin-resistant Staphylococcus aureus clone.

Objective: To describe the control of an outbreak of infection and colonization with the New York/Japan methicillin-resistant Staphylococcus aureus (MRSA) clone in multiple healthcare facilities, and to demonstrate the importance of making an MRSA management policy involving molecular typing of MRSA into a statewide public health responsibility.

Setting: A range of healthcare facilities, including 2 metropolitan teaching hospitals and a regional hospital, as well as several community hospitals and long-term care facilities in a nonmetropolitan healthcare region.

Interventions: A comprehensive, statewide MRSA epidemiological investigation and management policy.