Altered Expression of Umbilical Cord Blood Levels of miR-181b and Its Downstream Target mUCH-L1 in Infants with Moderate and Severe Neonatal Hypoxic-Ischaemic Encephalopathy.

Hypoxic-ischaemic encephalopathy (HIE) remains one of the leading causes of neurological disability worldwide. No blood biomarker capable of early detection and classification of injury severity in HIE has been identified. This study aimed to investigate the potential of miRNA-181b (miR-181b) and its downstream target, ubiquitin C-terminal hydrolase-L1 (UCH-L1), to predict the severity of HIE. Full-term infants with perinatal asphyxia were recruited at birth and observed for the development of HIE, along with healthy controls. Levels of miR-181b and messenger UCH-L1 (mUCH-L1) in umbilical cord blood were determined using qRT-PCR. In total, 131 infants; 40 control, 50 perinatal asphyxia without HIE (PA) and 41 HIE, recruited across two separate cohorts (discovery and validation) were included in this study. Significant and consistent downregulation of miR-181b was observed in infants with moderate/severe HIE compared to all other groups in both cohorts: discovery 0.25 (0.16-0.32) vs 0.61 (0.26-1.39), p = 0.027 and validation 0.33 (0.15-1.78) vs 1.2 (0.071-2.09), p = 0.035. mUCH-L1 showed increased expression in infants with HIE in both cohorts. The expression ratio of miR-181b to mUCH-L1 was reduced in those infants with moderate/severe HIE in both cohorts: discovery cohort 0.23 (0.06-0.44) vs 1.59 (0.46-2.54), p = 0.01 and validation cohort 0.41 (0.10-0.81) vs 1.38 (0.59-2.56) in all other infants, p = 0.009. We have validated consistent patterns of altered expression in miR-181b/mUCH-L1 in moderate/severe neonatal HIE which may have the potential to guide therapeutic intervention in HIE.

Therapeutic aerosol bioengineering of targeted, inhalable microparticle formulations to treat Mycobacterium tuberculosis (MTb).

Therapeutic aerosol bioengineering (TAB) of Mycobacterium tuberculosis (MTb) therapies using inhalable microparticles offers a unique opportunity to target drugs to the site of infection in the alveolar macrophages, thereby increasing dosing in the lungs and limiting systemic exposure to often toxic drugs. Previous work by us used sophisticated, high content analysis to design the optimal poly(lactide-co-glycolic) acid (PLGA) microparticle for delivery of drugs to alveolar macrophages. Herein, we applied this technology to three different anti-MTb drugs. These formulations were then tested for encapsulation efficiency, drug-release, in vitro killing against MTb and aerosol performance. Methods for encapsulating each of the drugs in the PLGA microparticles were successfully developed and found to be capable of controlling the release of the drug for up to 4 days. The efficacy of each of the encapsulated anti-MTb drugs was maintained and in some cases enhanced post-encapsulation. A method of processing these drug-loaded microparticles for inhalation using standard dry powder inhaler devices was successfully developed that enabled a very high respirable dose of the drug to be delivered from a simple dry powder inhaler device. Overall, TAB offers unique opportunities to more effectively treat MTb with many potential clinical and economic benefits resulting.

Cellular targeting and trafficking of drug delivery systems for the prevention and treatment of MTb.

Targeted delivery of anti-tubercular therapeutics to alveolar macrophages via inhalation aims to achieve optimal concentration of the therapeutic in the mycobacteria's niche environment. However, several challenges need to be overcome when designing a system to achieve this targeted, intracellular delivery. The first objective is to design a system that is suitable for inhalation, i.e. it must be capable of deposition in the alveolar region of the lungs. The theme of this commentary will be on the biological barriers for intracellular targeting to alveolar macrophages once particles are deposited in the lungs with emphasis on the delivery of anti-tubercular therapy and implications for novel vaccine formulations. The commentary focuses on four key features: 1) How Mycobacterium tuberculosis enters and is trafficked through macrophages, 2) the mechanism by which current drug delivery systems (DDS) enter and are trafficked through cells and 3) How an ideal DDS for anti-tubercular therapy would be trafficked through the macrophage and 4) the potential for using DDS for novel anti-tubercular therapy and vaccine development. These four features of targeted DDS shall be discussed in relation to some new findings from our own research.

Assessment of osteopenia from spine radiographs using two different methods: the Chingford Study.

Two methods for diagnosing radiological osteopenia in thoracic (TS) and lumbar (LS) spine radiographs were assessed: a subjective conventional method (A) and a semiquantitative method (B), by comparing them with bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DEXA), in a population of "normal" women aged 45-70 years (n = 818). For both methods there was good intraobserver and interobserver reproducibility. BMDs were significantly lower with increasing radiological osteopenia grades (p < 0.001), and remained lower after adjustment for age and body mass index (p < 0.01). The proportion of subjects with DEXA-defined osteoporosis rose with increasing radiological osteopenia grades for both methods. The worst osteopenia categories identified 29.7-55.3% of women with DEXA-defined osteoporosis, compared with 6.1-11.7% in the "normal" categories. Both methods, however, showed a large degree of overlap of BMDs between the various radiological osteopenia grades. The sensitivity and specificity of method A in diagnosing osteoporosis were 45.3% and 78.4%, respectively, for the TS and 19.0% and 94.3%, respectively, for the LS. For method B the sensitivities and specificities were 8.8% and 96.1%, respectively (TS), and 10.2% and 95.6%, respectively (LS). Although both methods have poor sensitivities, "definite" or "high" grade osteopenia should be an indication for bone densitometry. The high specificities suggest that a "normal" (no osteopenia) X-ray is unlikely to have a significantly low BMD.

Reproducibility of bone ages when performed by radiology registrars: an audit of Tanner and Whitehouse II versus Greulich and Pyle methods.

This audit analysed the Tanner and Whitehouse II twenty bone (TW2) method of bone age assessment which was used in our department, and compared it with the Greulich and Pyle (GP) method. 50 previous bone ages were independently re-calculated by each of three registrars using both techniques, with the time taken to perform each assessment being recorded. For each method the interobserver variation was analysed in terms of the spread of results. The intraobserver variation in TW2 was determined by comparing the bone age originally reported with that subsequently calculated on the same film by the same registrar. The average spread of results was 0.74 years for TW2 method, and 0.96 years for the GP method and this difference is not statistically significant at the 5% level. The average intraobserver variation to TW2 was 0.33 years, but with 95% confidence limits of -0.87 to +1.53 years. The average time taken was 7.9 min for TW2 and 1.4 min for GP assessments. It was concluded that the GP method gave similar reproducibility and was faster than the TW2 method. Following clinical discussion the routine departmental bone age assessment method was changed from the TW2 to the GP method.