16(th) IHIW: population global distribution of killer immunoglobulin-like receptor (KIR) and ligands

In the last fifteen years, published reports have described KIR gene-content frequency distributions in more than 120 populations worldwide. However, there have been limited studies examining these data in aggregate to detect overall patterns of variation at regional and global levels. Here, we present a summary of the collection of KIR gene-content data for 105 worldwide populations collected as part of the 15th and 16th International Histocompatibility and Immunogenetics Workshops, and preliminary results for data analysis.

Towards a public health curriculum in undergraduate medicine

BACKGROUND

The need to adequately train medical professionals in public health has been recognised internationally. Despite this, public health curricula, particularly in undergraduate medicine, are poorly defined. This study explored the public health disciplines that newly qualified doctors in the United Kingdom (UK) should know.

METHODS

We developed a 31-item questionnaire covering public health subject areas and expected competencies that medical graduates should know. The questionnaire was then administered to a stratified sample of medically trained individuals across a number of postgraduate schools of public health in the UK. Following administration, a ranking list was developed by subject area and by competency.

RESULTS

There was an 85% response rate (69/81). Subject areas ranked highest included epidemiology, health promotion and health protection. Sociology and the history of public health ranked lowest. Competencies perceived as important by the respondents included understanding health inequalities, empowering people about health issues and assessing the effectiveness of healthcare programmes.

DISCUSSION

Our study identifies the expected public health subject areas and competencies that newly graduating medical students should know. They provide a context through which to begin addressing concerns over the disparity between these expectations and what is actually taught in medical school, highlighting the continuing need to reframe undergraduate public health education in the UK.

Combination treatment of stroke with sub-therapeutic doses of Simvastatin and human umbilical cord blood cells enhances vascular remodeling and improves functional outcome

Human umbilical cord blood cells (HUCBCs) have been employed as a restorative treatment for experimental stroke. In this study, we investigated whether transplantation of sub-therapeutic doses of HUCBCs and Simvastatin enhances cerebral vascular remodeling after stroke. Adult male Wistar rats (n=34) were subjected to transient middle cerebral artery occlusion (MCAo) and treated with: phosphate-buffered solution (PBS, gavaged daily for 7 days); Simvastatin (0.5mg/kg, gavaged daily for 7 days); HUCBCs (1×10(6), injected once via tail vein); and combination Simvasatin with HUCBCs, starting at 24h after MCAo. There was no significant difference between Simvastatin- or HUCBC-monotherapy and MCAo-alone group. Combination treatment 24h post-stroke significantly increased the perimeter of von Willebrand factor (vWF)-positive vessels, the diameter and density of alpha smooth muscle actin (αSMA)-positive arteries, and the percentage of 5-bromodeoxyuridine (BrdU)-positive endothelial cells (ECs) in the ischemic boundary zone (IBZ) compared with MCAo-alone or HUCBC-monotherapy 14 days after MCAo (p<0.05, n=8/group); Combination treatment significantly increased the densities of vWF-vessels and αSMA-arteries as well as the densities of BrdU-ECs and BrdU-positive smooth muscle cells (SMCs) in vascular walls in the IBZ compared with Simvastatin-monotherapy. Moreover, the increased BrdU-ECs and BrdU-SMCs were significantly correlated with neurological functional outcome 14 days after MCAo. Combination treatment also significantly increased the expression of Angiopoietin-1 (Ang1), Tie2 and Occludin in the IBZ (p<0.05, n=8/group). The in vitro experiments showed that combination treatment and Ang1 significantly increased capillary-like tube formation and arterial cell migration; anti-Ang1 significantly reduced combination treatment-induced tube-formation and artery cell migration (p<0.05, n=6/group). These findings indicated that a combination of sub-therapeutic doses of Simvastatin and HUCBCs treatment of stroke increases Ang1/Tie2 and Occludin expression in the ischemic brain, amplifies endogenous angiogenesis and arteriogenesis, and enhances vascular remodeling which in concert may contribute to functional outcome after stroke.

Nutrient and light limitation of periphyton in the River Thames: implications for catchment management

Soluble reactive phosphorus (SRP) concentrations in the River Thames, south east England, have significantly decreased from an annual maximum of 2100 μg l(-1) in 1997 to 344 in 2010, primarily due to the introduction of phosphorus (P) removal at sewage treatment works within the catchment. However, despite this improvement in water quality, phytoplankton biomass in the River Thames has greatly increased in recent years, with peak chlorophyll concentrations increasing from 87 μg l(-1) in the period 1997 to 2002, to 328 μg l(-1) in 2009. A series of within-river flume mesocosm experiments were performed to determine the effect of changing nutrient concentrations and light levels on periphyton biomass accrual. Nutrient enrichment experiments showed that phosphorus, nitrogen and silicon were not limiting or co-limiting periphyton growth in the Thames at the time of the experiment (August-September 2010). Decreasing ambient SRP concentration from 225 μg l(-1) to 173 μg l(-1) had no effect on periphyton biomass accrual rate or diatom assemblage. Phosphorus limitation became apparent at 83 μg SRP l(-1), at which point a 25% reduction in periphyton biomass was observed. Diatom assemblage significantly changed when the SRP concentration was reduced to 30 μg l(-1). Such stringent phosphorus targets are costly and difficult to achieve for the River Thames, due to the high population density and intensive agriculture within the Thames basin. Reducing light levels by shading reduced the periphyton accrual rate by 50%. Providing shading along the River Thames by planting riparian tree cover could be an effective measure to reduce the risk of excessive algal growth. If the ecology of the Thames is to reach the WFD's "good ecological status", then both SRP concentration reductions (probably to below 100 μg l(-1)) and increased shading will be required.

Spatial and temporal changes in chlorophyll-a concentrations in the River Thames basin, UK: are phosphorus concentrations beginning to limit phytoplankton biomass?

Chlorophyll-a and nutrient concentrations were monitored at weekly intervals across 21 river sites throughout the River Thames basin, southern England, between 2009 and 2011. Despite a 90% decrease in soluble reactive phosphorus (SRP) concentration of the lower River Thames since the 1990s, very large phytoplankton blooms still occur. Chlorophyll concentrations were highest in the mid and lower River Thames and the larger tributaries. Lowest chlorophyll concentrations were observed in the smaller tributaries, despite some having very high phosphorus concentrations of over 300 μg l(-1). There was a strong positive correlation between river length and mean chlorophyll concentration (R(2)=0.82), and rivers connected to canals had ca. six times greater chlorophyll concentration than 'natural' rivers with similar phosphorus concentrations, indicating the importance that residence time has on determining phytoplankton biomass. Phosphorus concentration did have some influence, with phosphorus-enriched rivers having much larger phytoplankton blooms than nutrient-poor rivers of a similar length. Water quality improvements may now be capping chlorophyll peaks in the Rivers Thames and Kennet, due to SRP depletion during the spring/early summer phytoplankton bloom period. Dissolved reactive silicon was also depleted to potentially-limiting concentrations for diatom growth in the River Thames during these phytoplankton blooms, but nitrate remained in excess for all rivers throughout the study period. Other potential mitigation measures, such as increasing riparian shading and reducing residence times by removing impoundments may be needed, alongside phosphorus mitigation, to reduce the magnitude of phytoplankton blooms in the future.

Clinical outcomes of osteomyelitis patients infected with methicillin-resistant Staphylococcus aureus USA-300 strains

Methicillin-resistant Staphylococcus aureus (MRSA) USA-300 strains have emerged as an important cause of community-acquired infections. These strains have been recognized as an etiology of osteomyelitis but data on their incidence and outcomes are limited. We retrospectively studied the incidence and clinical outcomes of MRSA USA-300 osteomyelitis in patients at the University of Louisville Hospital and the Henry Ford Health System between January 2007 and March 2008. Pulsed-field gel electrophoresis was used to determine USA type. Clinical outcomes were defined as management success versus failure at 12 months. Chi-square tests, Fisher exact tests, and Mann-Whitney tests were used to compare patient characteristics on the basis of clinical outcomes and USA type. Of the 50 patients with MRSA osteomyelitis, 27 (54%) had the USA-300 strain. Clinical failure was identified in 22% (6/27) of the patients with MRSA USA-300 and in 30% (7/23) of the patients with MRSA non-USA-300 osteomyelitis (P = .509). Our results showed that MRSA USA-300 is a significant etiology of MRSA osteomyelitis. With current surgical and medical management, outcomes of patients with MRSA USA-300 osteomyelitis are similar to those of patients with MRSA non-USA-300 osteomyelitis.

Factors associated with a difficult induction of general anaesthesia

BACKGROUND

Many children experiencing a procedure under general anaesthetic (GA), including those having surgery for cochlear implantation, display behaviours indicative of distress during induction of anaesthesia. It would be useful to ascertain which factors in the pre-operative period are related to the presence of distress at induction in order to target appropriate psychological preparation.

METHODS

The families of 84 children aged 4-7 years undergoing a procedure under GA (including insertion of a cochlear implant) completed three questionnaires assessing temperament, behavioural difficulties, and pre-operative worries. Demographic variables were also recorded. The outcome measure was the amount of behavioural distress at induction.

RESULTS

Statistically significant relationships with the outcome measure of distress at induction were obtained for three factors; an emotional or sociable temperament, and the number of previous procedures. Further, children receiving inhalation inductions displayed greater distress than those receiving intravenous inductions.

CONCLUSION

Undergoing cochlear implantation under GA is a major life event for many recipients. Psychologically preparing children for this has been found to be efficacious, but is not currently available to all children. It is suggested that preparation can be targeted at children, as identified in this study, who have elevated emotionality or sociability scores or who have previous experience of procedures under general anaesthesia. This is of particular current relevance as children are increasingly likely to require re-implantation as they grow older and as unilaterally implanted children are now being offered a sequential bilateral implant, both necessitating further surgery.

Frequency distribution of SPARC in triple-negative breast cancer patients

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Background: SPARC (secreted protein acid rich in cysteine) belongs to a group of extracellular matrix proteins and promotes adhesion of cells from the matrix. It plays an important role in tumor development in breast cancer and has a significant bearing on patient prognosis and long term survival. It is also known to predict response to nab-paclitaxel in certain tumor types including breast cancer. In 2005, FDA approved a solvent free formulation of paclitaxel for the treatment of metastatic breast cancer that utilizes albumin bound (nab) technology (nab-paclitaxel). Clinical studies have shown that nab-paclitaxel is significantly more effective than paclitaxel. Our study evaluated the frequency distribution of SPARC among triple negative breast cancer patients in which identification of a novel therapeutic target is warranted.

Methods: In a total of 951 breast cancer patients, we analyzed tumor SPARC expression by immunohistochemistry (IHC) using a monoclonal (R&D Systems) and a polyclonal antibody (Exalpha Biologicals). Immunoreactivity was assessed by scoring the percentage of cells stained in each field and by the intensity of staining. A cutoff point of 2+ and >30% stained tumor cells were considered as positive.

Results: From our analysis of 951 breast cancer patients profiled, a total of 165 patients (17%) were triple negative for ER, PR and HER2. Within this pathologic subtype, 29% patients stained positive with SPARC monoclonal antibody and 21% stained positive with SPARC polyclonal antibody. The correlation of SPARC tumor staining with hormone receptor status will be presented in detail.

Conclusions: We conclude that SPARC over-expression is a functionally important feature of a subset of triple negative breast cancer patients. The triple negative subset of tumors generally has a more aggressive clinical course and does not benefit from conventional targeted therapies. Our study suggests that nab-paclitaxel may serve as a therapeutic agent for the subset of triple negative patients that over-express SPARC. To the best of our knowledge, this is the first study involving a large patient pool in which SPARC has been investigated in a single clinical laboratory using standardized IHC with two different SPARC antibodies.

Effects of hypothyroidism on the structure and mechanical properties of bone in the ovine fetus

Thyroid hormones are important for normal bone growth and development in postnatal life. However, little is known about the role of thyroid hormones in the control of bone development in the fetus. Using computed tomography and mechanical testing, the structure and strength of metatarsal bones were measured in sheep fetuses in which thyroid hormone levels were altered by thyroidectomy or adrenalectomy. In intact fetuses, plasma concentrations of total calcium and the degradation products of C-terminal telopeptides of type I collagen increased between 100 and 144 days of gestation (term 145±2 days), in association with various indices of bone growth and development. Thyroid hormone deficiency induced by thyroidectomy at 105-110 days of gestation caused growth retardation of the fetus and significant changes in metatarsal bone structure and strength when analyzed at both 130 and 144 days of gestation. In hypothyroid fetuses, trabecular bone was stronger with thicker, more closely spaced trabeculae, despite lower bone mineral density. Plasma osteocalcin was reduced by fetal thyroidectomy. Removal of the fetal adrenal gland at 115-120 days of gestation, and prevention of the prepartum rises in cortisol and triiodothyronine, had no effect on bodyweight, limb lengths, metatarsal bone structure or strength, or circulating markers of bone metabolism in the fetuses studied near term. This study demonstrates that hypothyroidism in utero has significant effects on the structure and strength of bone, with different consequences for cortical and trabecular bone.

DCE-MRI biomarkers of tumour heterogeneity predict CRC liver metastasis shrinkage following bevacizumab and FOLFOX-6

BACKGROUND

There is limited evidence that imaging biomarkers can predict subsequent response to therapy. Such prognostic and/or predictive biomarkers would facilitate development of personalised medicine. We hypothesised that pre-treatment measurement of the heterogeneity of tumour vascular enhancement could predict clinical outcome following combination anti-angiogenic and cytotoxic chemotherapy in colorectal cancer (CRC) liver metastases.

METHODS

Ten patients with 26 CRC liver metastases had two dynamic contrast-enhanced MRI (DCE-MRI) examinations before starting first-line bevacizumab and FOLFOX-6. Pre-treatment biomarkers of tumour microvasculature were computed and a regression analysis was performed against the post-treatment change in tumour volume after five cycles of therapy. The ability of the resulting linear model to predict tumour shrinkage was evaluated using leave-one-out validation. Robustness to inter-visit variation was investigated using data from a second baseline scan.

RESULTS

In all, 86% of the variance in post-treatment tumour shrinkage was explained by the median extravascular extracellular volume (v(e)), tumour enhancing fraction (E(F)), and microvascular uniformity (assessed with the fractal measure box dimension, d(0)) (R(2)=0.86, P<0.00005). Other variables, including baseline volume were not statistically significant. Median prediction error was 12%. Equivalent results were obtained from the second scan.

CONCLUSION

Traditional image analyses may over-simplify tumour biology. Measuring microvascular heterogeneity may yield important prognostic and/or predictive biomarkers.