Bioactive composites for bone tissue engineering.

One of the major challenges for bone tissue engineering is the production of a suitable scaffold material. In this review the currently available composite material options are considered and the methods of production and assessing the scaffolds are also discussed. The production routes range from the use of porogens to produce the porosity through to controlled deposition methods.

Publishing SNP genotypes of human embryonic stem cell lines: policy statement of the International Stem Cell Forum Ethics Working Party.

Novel methods and associated tools permitting individual identification in publicly accessible SNP databases have become a debatable issue. There is growing concern that current technical and ethical safeguards to protect the identities of donors could be insufficient. In the context of human embryonic stem cell research, there are no studies focusing on the probability that an hESC line donor could be identified by analyzing published SNP profiles and associated genotypic and phenotypic information.

PHOSPHO1 is essential for mechanically competent mineralization and the avoidance of spontaneous fractures.

Phosphatases are essential for the mineralization of the extracellular matrix within the skeleton. Their precise identities and functions however remain unclear. PHOSPHO1 is a phosphoethanolamine/phosphocholine phosphatase involved in the generation of inorganic phosphate for bone mineralization.

Dissecting regional variations in stress fiber mechanics in living cells with laser nanosurgery.

The ability of a cell to distribute contractile stresses across the extracellular matrix in a spatially heterogeneous fashion underlies many cellular behaviors, including motility and tissue assembly. Here we investigate the biophysical basis of this phenomenon by using femtosecond laser nanosurgery to measure the viscoelastic recoil and cell-shape contributions of contractile stress fibers (SFs) located in specific compartments of living cells. Upon photodisruption and recoil, myosin light chain kinase-dependent SFs located along the cell periphery display much lower effective elasticities and higher plateau retraction distances than Rho-associated kinase-dependent SFs located in the cell center, with severing of peripheral fibers uniquely triggering a dramatic contraction of the entire cell within minutes of fiber irradiation.

Vocal function exercises for presbylaryngis: a multidimensional assessment of treatment outcomes.

Objectives: Presbylaryngis, or aging of the larynx, can adversely affect vocal function and quality of life in the elderly. This preliminary investigation examined the effects of vocal function exercises, a physiologic voice therapy approach, as a primary treatment for presbylaryngis.

Methods: Nine consecutive elderly patients with presbylaryngis (2 female, 7 male) underwent a 6-week course of voice therapy employing vocal function exercises.

Nebulized isotonic saline versus water following a laryngeal desiccation challenge in classically trained sopranos.

Purpose: To examine the effects of nebulized isotonic saline (IS) versus sterile water (SW) on self-perceived phonatory effort (PPE) and phonation threshold pressure (PTP) following a surface laryngeal dehydration challenge in classically trained sopranos.

Method: In a double-blind, within-subject crossover design, 34 sopranos breathed dry air (relative humidity < 1%) transorally for 15 min and then nebulized 3 mL of IS or SW, or experienced a no-treatment control condition over 3 consecutive weeks. PPE and PTP were measured every 15 min from baseline through 2 hr postdesiccation.

Bioactive ceramic-reinforced composites for bone augmentation.

Biomaterials have been used to repair the human body for millennia, but it is only since the 1970s that man-made composites have been used. Hydroxyapatite (HA)-reinforced polyethylene (PE) is the first of the 'second-generation' biomaterials that have been developed to be bioactive rather than bioinert. The mechanical properties have been characterized using quasi-static, fatigue, creep and fracture toughness testing, and these studies have allowed optimization of the production method.

A multi-component fiber-reinforced PHEMA-based hydrogel/HAPEX™ device for customized intervertebral disc prosthesis.

Spinal disease due to intervertebral disc degeneration represents a serious medical problem which affects many people worldwide. Disc arthroplasty may be considered the future ''gold standard'' of back pain treatment, even if problems related to available disc prostheses are considered. Hence, the aim of the present study was to improve the artificial disc technology by proposing the engineering of a pilot-scale device production process for a total multi-component intervertebral disc prosthesis.

Risk and protective factors for spasmodic dysphonia: a case-control investigation.

Objectives: Spasmodic dysphonia (SD) is a chronic, incurable, and often disabling voice disorder of unknown pathogenesis. The purpose of this study was to identify possible endogenous and exogenous risk and protective factors uniquely associated with SD.

Study Design: Prospective, exploratory, case-control investigation.

3-Aryl-4-(arylhydrazono)-1H-pyrazol-5-ones: Highly ligand efficient and potent inhibitors of GSK3beta.

A series of 3-aryl-4-(arylhydrazono)-1H-pyrazol-5-one inhibitors of GSK3beta was developed from a low molecular weight, highly ligand efficient screening hit 1. Hit-to-lead optimization led to a number of highly potent inhibitors, while maintaining the high ligand efficiency of the screening hit.

Probing cellular mechanobiology in three-dimensional culture with collagen-agarose matrices.

The study of how cell behavior is controlled by the biophysical properties of the extracellular matrix (ECM) is limited in part by the lack of three-dimensional (3D) scaffolds that combine the biofunctionality of native ECM proteins with the tunability of synthetic materials. Here, we introduce a biomaterial platform in which the biophysical properties of collagen I are progressively altered by adding agarose. We find that agarose increases the elasticity of 3D collagen ECMs over two orders of magnitude with modest effect on collagen fiber organization.

Coherent movement of cell layers during wound healing by image correlation spectroscopy.

We have determined the complex sequence of events from the point of injury until reepithelialization in axolotl skin explant model and shown that cell layers move coherently driven by cell swelling after injury. We quantified three-dimensional cell migration using correlation spectroscopy and resolved complex dynamics such as the formation of dislocation points and concerted cell motion. We quantified relative behavior such as velocities and swelling of cells as a function of cell layer during healing.

Comparison of two methods of fatigue testing bone cement.

Two different methods have been used to fatigue test four bone cements. Each method has been used previously, but the results have not been compared. The ISO 527-based method tests a minimum of 10 samples over a single stress range in tension only and uses Weibull analysis to calculate the median number of cycles to failure and the Weibull modulus.

Vocal fold bowing in elderly male monozygotic twins: a case study.

This case study examined case histories, diagnostic features, and treatment response in two 79-year-old male monozygotic (identical) twins with vocal fold bowing, exploring both genetic and environmental factors. DNA concordance was examined via cheek swab. Case histories, videostroboscopy, auditory- and visual-perceptual assessment, electromyography, acoustic measures, and Voice Handicap ratings were undertaken.

Absorption and release of protein from hydroxyapatite-polylactic acid (HA-PLA) membranes.

Objectives: The aim of this study was to investigate the kinetics of protein interactions with a novel hydroxyapatite-polylactide (HA-PLA) composite membrane material.

Methods: Trilayer PLA and HA-PLA composite membranes reinforced with PLA fibres were used to absorb and release protein which was measured by a BioRad assay. The proteins used were fetal calf serum and bovine serum albumin.

Hepatitis a outbreak epidemiologically linked to a food handler in Melbourne, Victoria.

Hepatitis A is caused by the hepatitis A virus (HAV). Transmission occurs by the faecal-oral route, either by direct contact with an HAV-infected person or by ingestion of HAV-contaminated food or water. Hepatitis A outbreaks are uncommon in Australia.

Circulating CD34+ Cell Count is Associated with Extent of Subclinical Atherosclerosis in Asymptomatic Amish Men, Independent of 10-Year Framingham Risk.

Background: Bone-marrow derived progenitor cells (PCs) may play a role in maintaining vascular health by actively repairing damaged endothelium. The purpose of this study in asymptomatic Old Order Amish men (n = 90) without hypertension or diabetes was to determine if PC count, as determined by CD34+ cell count in peripheral blood, was associated with 10-year risk of cardiovascular disease (CVD) and measures of subclinical atherosclerosis.

Methods And Results: CD34+ cell count by fluorescence-activated cell sorting, coronary artery calcification (CAC) by electron beam computed tomography, and CVD risk factors were obtained.

In vitro biocompatibility of hydroxyapatite-reinforced polymeric composites manufactured by selective laser sintering.

The selective laser sintering (SLS) technique was used to manufacture hydroxyapatite-reinforced polyethylene and polyamide composites as potential customized maxillofacial implants. In vitro tests were carried out to assess cellular responses, in terms of cell attachment, morphology, proliferation, differentiation, and mineralized nodule formation, using primary human osteoblast cells. This study showed that the SLS composite processed was biocompatible, with no adverse effects observed on cell viability and metabolic activity, supporting a normal metabolism and growth pattern for osteoblasts.