The Effect of Liposome Encapsulation on the Pharmacokinetics of Recombinant Secretory Leukocyte Protease Inhibitor (rSLPI) Therapy after Local Delivery to a Guinea Pig Asthma Model

Inhaled recombinant Secretory Leukocyte Protease Inhibitor (rSLPI) has shown potential for treatment of inflammatory lung conditions. Rapid inactivation of rSLPI by cathepsin L (Cat L) and rapid clearance from the lungs have limited clinical efficacy. Encapsulation of rSLPI within 1,2-Dioleoyl-sn-Glycero-3-[Phospho-L-Serine]:Cholesterol liposomes (DOPS-rSLPI) protects rSLPI against Cat L inactivation in vitro. We aimed to determine the effect of liposomes on rSLPI pharmacokinetics and activity in vitro and after local delivery to the airways in vivo.

Examination of the physical state of chlorhexidine within viscoelastic, bioadhesive semisolids using Raman spectroscopy

This study examined the effects of polymeric components on the physical state of chlorhexidine within bioadhesive, semisolid formulations using Raman spectroscopy. Semisolid formulations were prepared in which chlorhexidine base (CHX, 5%w/w, particle size

Increased Promiscuity of Human Galactokinase Following Alteration of a Single Amino Acid Residue Distant from the Active Site

Galactokinase catalyses the site-and stereospecific phosphorylation of galactose at the expense of ATP. The specificity of bacterial galactokinase enzymes can be broadened by alteration of a tyrosine residue to a histidine. The effects of altering the equivalent residue in human galactokinase (Tyr379) were investigated by testing all 19 possible variants. All of these alterations, except Y379P, resulted in soluble protein on expression in Escherichia coli and all the soluble variants could catalyse the phosphorylation of galactose, except Y379A and Y379E. The variants Y379C, Y379K, Y379R, Y379S and Y379W were all able to catalyse the phosphorylation of a variety of monosaccharides, including ones that are not acted on by the wild-type enzyme. Novel substrates for these variant galactokinases included D-mannose and D-fructose. The latter monosaccharide is presumed to react in the pyranose configuration. Molecular modelling suggested that the alterations do not cause changes to the overall structure of the enzyme. However, alteration of Tyr379 increases the flexibility of the peptide backbone in regions surrounding the active site. Therefore, it is proposed that alteration of Tyr379 affects the substrate specificity by the propagation of changes in flexibility to the active site, permitting a broader range of compounds to be accommodated.

Implications for Powering Biomarker Discovery Studies

This study examined variations in gene expression between FFPE blocks within tumors of individual patients. Microarray data were used to measure tumor heterogeneity within and between patients and disease states. Data were used to determine the number of samples needed to power biomarker discovery studies. Bias and variation in gene expression were assessed at the intrapatient and interpatient levels and between adenocarcinoma and squamous samples. A mixed-model analysis of variance was fitted to gene expression data and model signatures to assess the statistical significance of observed variations within and between samples and disease states. Sample size analysis, adjusted for sample heterogeneity, was used to determine the number of samples required to support biomarker discovery studies. Variation in gene expression was observed between blocks taken from a single patient. However, this variation was considerably less than differences between histological characteristics. This degree of block-to-block variation still permits biomarker discovery using either macrodissected tumors or whole FFPE sections, provided that intratumor heterogeneity is taken into account. Failure to consider intratumor heterogeneity may result in underpowered biomarker studies that may result in either the generation of longer gene signatures or the inability to identify a viable biomarker. Moreover, the results of this study indicate that a single biopsy sample is suitable for applying a biomarker in nonsmall-cell lung cancer. © 2012 American Society for Investigative Pathology and the Association for Molecular Pathology.

Concise Review: Stem Cell Effects in Radiation Risk

Stem cells of normal mammalian tissues are defined as nonspecialized cells that have two critical properties: (a) the ability to renew themselves through cell division and (b) the potency to differentiate into other cell types. Therefore, they play a crucial role in development and in tissue homeostasis during adult life. Being long-lived, they can be the targets of environmental carcinogens leading to the accumulation of consecutive genetic changes. Hence, the genome of stem cells must be exceptionally well protected, and several protective mechanisms have evolved to ensure the genetic integrity of the stem cell compartment in any given tissue. Ionizing radiation exposure can disrupt tissue homeostasis both through the induction of cell killing/depletion of radiosensitive stem cells, leading to loss of tissue functionality and by genotoxic damage, increasing overall risk of cancer. We will review the current knowledge about radiation effects in adult stem cells of specific normal tissues, including skin, breast, and brain, examine parallels, as well as differences with cancer stem cells, and discuss the relevance of stem cell effects to radiation risk and radiotherapy. STEM CELLS 2011;29:1315-1321

Altered distribution of interstitial cells and innervation in the rat urinary bladder following spinal cord injury

Introduction Changes in the distribution of interstitial cells (IC) are reportedly associated with dysfunctional bladder. The present study investigated whether spinal cord injury (SCI) resulted in changes to IC subpopulations (vimentin-positive with the ultrastructural profile of IC), smooth muscle and nerves within the bladder wall and correlated cellular remodelling with functional properties. Methods Bladders from SCI (T8/9 transection) and sham-operated rats five-weeks post-injury were used for ex vivo pressure-volume experiments or processed for morphological analysis with transmission electron microscopy (TEM) and light/confocal microscopy. Results Pressure-volume relationships revealed low-pressure, hypercompliance in SCI bladders indicative of decompensation. Extensive networks of vimentin-positive IC were typical in sham lamina propria and detrusor but were markedly reduced post-SCI; semi-quantitative analysis showed significant reduction. Nerves labelled with anti-neurofilament and anti-vAChT were notably decreased post-SCI. TEM revealed lamina propria IC and detrusor IC which formed close synaptic-like contacts with vesicle-containing nerve varicosities in shams. Lamina propria and detrusor IC were ultrastructurally damaged post-SCI with retracted/lost cell processes and were adjacent to areas of cellular debris and neuronal degradation. Smooth muscle hypertrophy was common to SCI tissues. Conclusions IC populations in bladder wall were decreased five weeks post-SCI, accompanied with reduced innervation, smooth muscle hypertrophy and increased compliance. These novel findings indicate that bladder wall remodelling post-SCI affects the integrity of interactions between smooth muscle, nerves and IC, with compromised IC populations. Correlation between IC reduction and a hypercompliant phenotype suggests that disruption to bladder IC contribute to pathophysiological processes underpinning the dysfunctional SCI bladder.

Eyes open to stem cells: safety trial may pave the way for cell therapy to treat retinal disease in patients

A clinical trial using human embryonic stem cell (hESC) therapy for an inherited retinal degenerative disease is about to commence. The Advanced Cell Technology (ACT) trial will treat patients with Stargardt's macular dystrophy using transplanted retinal pigment epithelium derived from hESCs. Currently, no effective treatment is available for Stargardt's disease so a stem cell-based therapy that can slow progression of this blinding condition could represent a significant breakthrough. While there are some hurdles to clear, the ACT trial is a fine example of translational research that could eventually pave the way for a range of stem cell therapies for the retina and other tissues.

Protection of cattle against a natural infection of Fasciola hepatica by vaccination with recombinant cathepsin L1 (rFhCL1)

The liver fluke, Fasciola hepatica causes liver fluke disease, or fasciolosis, in ruminants such as cattle and sheep. An effective vaccine against the helminth parasite is essential to reduce our reliance on anthelmintics, particularly in light of frequent reports of resistance to some frontline drugs. In our study, Friesian cattle (13 per group) were vaccinated with recombinant F. hepatica cathepsin L1 protease (rFhCL1) formulated in mineral-oil based adjuvants, Montanide (TM) ISA 70VG and ISA 206VG. Following vaccination the animals were exposed to fluke-contaminated pastures for 13 weeks. At slaughter, there was a significant reduction in fluke burden of 48.2% in the cattle in both vaccinated groups, relative to the control non-vaccinated group, at p