'Clinical scaphoid fracture': is it time to abolish this phrase?

INTRODUCTION

Most patients with post-traumatic painful wrists and negative radiographs are treated as having a clinical scaphoid fracture. Such cases are usually followed up with repeat radiographs. If the radiographs are inconclusive further imaging is done. However, this traditional approach results in the vast majority of patients being unnecessarily immobilised for an unspecified period, leading to loss of productivity and income to the patient and the community. A number of studies have highlighted the use of early CT or MRI scans to identify these fractures. The aim of this study was to evaluate our current practice in managing patients with suspected fractures of the scaphoid.

PATIENTS AND METHODS

A retrospective audit was carried out. The period studied was from January to August 2008. Fifty consecutive patients who were investigated for occult fractures of the scaphoid were included.

RESULTS

92% of the patients studied had a repeat radiograph in the fracture clinic. 84% of the patients had their wrists immobilised in a cast while awaiting further imaging. Only 6% had confirmed fracture of the scaphoid; all of these healed uneventfully. 76% of patients with negative scans had their wrists immobilised for an average period of 30.63 days.

CONCLUSIONS

It is time we rethink this dogmatic approach to patients with clinical signs but negative radiographs. We recommend that patients with a painful wrist following an injury and negative radiographs should be referred early to an appropriate clinician and earlier recourse to advanced imaging should be advocated.

Hydrodynamic delivery of plasmid DNA encoding human FcγR-Ig dimers blocks immune-complex mediated inflammation in mice

Therapeutic use and function of recombinant molecules can be studied by the expression of foreign genes in mice. In this study, we have expressed human Fcgamma receptor –Ig fusion molecules (FcγR-Igs) in mice by administering FcγR-Ig plasmid DNAs hydrodynamically and compared their effectiveness to purified molecules in blocking immune-complex (IC) mediated inflammation in mice. The concentration of hydrodynamically expressed FcγR-Igs (CD16A^F-Ig, CD32A^R-Ig and CD32A^H-Ig) reached a maximum of 130 μg/ml of blood within 24 h after plasmid DNA administration. The in vivo half-life of FcγR-Igs was found to be 9-16 days and Western blot analysis showed that the FcγR-Igs were expressed as a homodimer. The hydrodynamically expressed FcγR-Igs blocked 50-80% of IC-mediated inflammation up to 3 days in a reverse passive Arthus reaction model. Comparative analysis with purified molecules showed that hydrodynamically expressed FcγR-Igs are more efficient than purified molecules in blocking IC-mediated inflammation and had a higher half-life. In summary, these results suggest that the administration of a plasmid vector with a FcγR-Ig gene can be used to study the consequences of blocking IC-binding to FcγRs during the development of inflammatory diseases. This approach may have potential therapeutic value in treating IC-mediated inflammatory autoimmune diseases such as lupus, arthritis and autoimmune vasculitis.

Respiratory gated simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) after breast conservative surgery for carcinoma of the breast: The Salmaniya Medical complex experience

PURPOSE

To present our clinical experience using SIB-IMRT Technique for Intact Breast cancer.

MATERIALS AND METHODS

A retrospective review of 45 cases of Stage I-IV breast cancer patients treated with SIB-IMRT with respiratory gating after Conservative treatments from 25th November 2008 to 16th February 2010. The most common fractionation was 1.8 Gy to Ipsilateral Breast tissue and 2.2 Gy to the lumpectomy cavity giving whole breast dose as 50.4 Gy and Lumpectomy cavity dose as 61.6 Gy over 28 fractions concomitantly. Respiratory gating was done and CT-images were taken in inspiratory breath hold position.

RESULTS

A total of 45 patients with breast cancer - stage I (17.7%), II (71%), III (8.9%), IV (2.2%) were treated with SIB- IMRT with respiratory gated radiotherapy. Out of 45 patients, 24 are of left sided breast cancer and 21 are of right sided breast cancer patients. The median, Dose maximum (D-max) in SIB-IMRT is 106.2% of prescribed lumpectomy site dose. The median isodose line prescribed to PTV-2 is 100%. The Conformity index (CI) is 0.9688 (median value) and Homogeneity index (HI) 1.06 (median). The median ipsilateral lung, mean dose is 21.66 Gy and V-20 is 37.4%. For left sided cases the median value of mean heart dose, V-30 and V-40 are 22.98 Gy, 23.45% and 9.45 % respectively. Acute skin toxicity was of Grade-I in 2.2 %, Grade-II in 64.4 %, Grade-III in 31.1 %, and Grade-IV in 2.2 %. The global Breast cosmoses were seen excellent in majority (93%) of case at median follow up of 8 months duration.

CONCLUSIONS

Breast SIB-IMRT Technique is feasible and comparable with other treatment techniques with reduced treatment duration by six fractions. At median follow up of 8 months the skin toxicity and cosmoses are excellent in high percentage of cases.

The heterogeneity of antipsychotic response in the treatment of schizophrenia

BACKGROUND

Schizophrenia is a heterogeneous disorder in terms of patient response to antipsychotic treatment. Understanding the heterogeneity of treatment response may help to guide treatment decisions. This study was undertaken to capture inherent patterns of response to antipsychotic treatment in patients with schizophrenia, characterize the subgroups of patients with similar courses of response, and examine illness characteristics at baseline as possible predictors of response.

METHOD

Growth mixture modeling (GMM) was applied to data from a randomized, double-blind, 12-week study of 628 patients with schizophrenia or schizo-affective disorder treated with risperidone or olanzapine.

RESULTS

Four distinct response trajectories based on Positive and Negative Syndrome Scale (PANSS) total score over 12 weeks were identified: Class 1 (420 patients, 80.6%) with moderate average baseline PANSS total score showing gradual symptom improvement; Class 2 (65 patients, 12.5%) showing rapid symptom improvement; Class 3 (24 patients, 4.6%) with high average baseline PANSS total score showing gradual symptom improvement; and Class 4 (12 patients, 2.3%) showing unsustained symptom improvement. Latent class membership of early responders (ER) and early non-responders (ENR) was determined based on 20% symptom improvement criteria at 2 weeks and ultimate responders (UR) and ultimate non-responders (UNR) based on 40% symptom improvement criteria at 12 weeks. Baseline factors with potential influence on latent class membership were identified.

CONCLUSIONS

This study identified four distinct treatment response patterns with predominant representation of responders or non-responders to treatment in these classes. This heterogeneity may represent discrete endophenotypes of response to treatment with different etiologic underpinnings.

A nanotechnology-based delivery system: Nanobots. Novel vehicles for molecular medicine

AIM

We previously demonstrated that adenovirus-mediated p53 gene transfer following balloon angioplasty, decreased neointimal hyperplasia. However, safety concerns arise because viral promoters can cause unrestricted transgene expression. The paucity of safe and efficient vehicles for gene transfer thus limits the potential for clinical utilization of gene therapy. Our objective was to design and clone a virus-free p53 construct, targeted to express specifically in vascular smooth muscle cells (SMCs), via a nanoparticle-based delivery system for therapeutic modulation in vascular wall.

METHODS

Biodegradable poly(lactide-co-glycolide) (PLGA), an FDA approved polymer, was used to formulate the nanoparticles. Cloned constructs consisting of SMC promoter, SM22, and p53 cDNA sequences along with enhanced green fluorescent protein (EGFP) gene, were loaded into PLGA nanoparticles. The affect of these nanobots on cell growth was examined.

RESULTS

The gene sequences carried by the nanobot are expressed in target cells. The p53/EGFP construct under the constitutive promoter was found to express in 293T human embryonic kidney cells, whereas the p53/EGFP with SMC promoter expressed only in human aortic SMCs. SMCs internalize these nanobots without compromising cell viability or growth kinetics.

CONCLUSION

A novel genetic sequence that targets a specific cell population has been successfully designed, cloned and encapsulated in a nanoparticle. This experiment is a significant step towards the development of a nanoparticle-based delivery system for therapeutic delivery of targeted gene-therapy towards attenuation of restenosis. Further work is necessary to expand the repertoire of this delivery system and determine whether it could become a versatile vehicle in molecular medicine.

Identification of weather parameters related to regional population outbreak risk of common voles (Microtus arvalis) in Eastern Germany

Context Common vole (Microtus arvalis) populations can increase to several thousand individuals per hectare during outbreaks. In central Europe such outbreaks usually extend across large areas but there can be significant regional differences in outbreak intensity, general outbreak risk and associated crop damage. Aims We tested whether weather parameters can be used to explain the regional variability in outbreak risk of common voles in an area of Eastern Germany where common vole outbreaks are common. Method Suitable weather parameters were identified by principal component analysis (PCA). Time series of common vole abundance from 50 locations across 36 500 km2 sampled in 1973–97 were related to weather parameters selected by PCA and multiple linear regression. A hierarchical cluster analysis was used on relevant weather parameters to display the temporal and spatial variability in vole abundance. An overlay of risk class transformed abundances allowed for the identification of appropriate threshold values to define vole outbreaks. Key results Weather parameters were closely related to the variation in regional outbreak risk of common voles. Mostly weather parameters in winter and early spring were identified to be highly important. All risk thresholds tested revealed similar patterns for the distribution of risk classes across locations and years. While most years of very low or very high outbreak risk clustered well according to weather parameters, some cases of medium risk classes did not cluster well. Conclusions Weather parameters especially in winter and early spring are related to common vole outbreak risk in the following autumn. This is the case for extremely high and low outbreak risks and is largely independent of the choice of particular threshold values for outbreak risk. Implications Weather parameters could be used to develop automated forecast systems at the spatial resolution of single weather stations. Combined with other parameters that are easily available, such as information on soil characteristics, such forecasts might be as reliable as more complex biological models developed in the past.

Abstract S3-7: Kinome Screening for Regulators of Estrogen Receptor Identifies a Novel Kinase as a New Therapeutic Target in Breast Cancer

Background: Estrogen Receptor (ER) positive breast cancer is usually treated with hormone reduction or anti-estrogens. Still, only half the ER+ breast tumors respond to tamoxifen. Mutations in ER are rarely found; instead other mechanisms have been associated with resistance, namely phosphorylation of ERα. Since phosphorylation has been shown to be important for the stimulation of its transcriptional activity, focusing on the role of kinases and the influence of site specific phosphorylation in modulating activity may reveal fundamental insights and derive new druggable targets for exploitation in the clinic.

Materials and Methods: A systematic high-throughput RNAi screening using a large Human Kinase siRNA Library was carried out to identify novel kinases able to phosphorylate and/or modulate ERα activity; quantitative real-time RT-PCR analysis of pS2, PR and GREB1, three well characterized ERα-regulated genes, was performed after silencing each kinase individually. We then examined the effects of each newly identified kinase on various ERα features/functions including: i) ERα stability (Western blot), ii) ERα sub-cellular localization (confocal microscopy) and iii) ERα interactions with major components of the transcriptional machinery (co-immunoprecipitation). In addition, we examined the effects of these kinases on i) cell-cycle progression (FACS), ii) proliferation rate (MTT) and, iii) apoptosis levels (Annexin V, Caspase assays). We assessed clinical significance of our observations, by analyzing the expression of the novel kinases in BC tissue microarrays (TMAs, n=614) by immunohistochemistry.

Results: We have categorized the newly identified kinases in two groups depending on their effects on ERα transcriptional activity (30% up-regulation - 70% down-regulation). Among them, we discovered a novel receptor tyrosine kinase (RTK) whose role and/or involvement in ERα regulation has not been described thus far. We demonstrated that silencing of this kinase resulted in a great down-regulation (>70-80%) of all 3 ERα-regulated genes tested (pS2, GREB1, PGR). In addition, upon kinase-silencing, we observed a large decrease in ERα protein levels, suggesting an involvement of this kinase in ERαα stability. Moreover, silencing of this kinase resulted in a >50% decrease of breast cancer cells viability (P<0.001). Analysis of the BC TMAs, the kinase of interest was expressed in weak (27%), moderate (35%) and high levels (38%). High expression correlated significantly with high tumor grade (P<0.001) and predicted for worse BC specific overall survival (p=0.03).

Discussion: As RTKs are considered the primary mediators of the signalling network that transmit extracellular signals into the cell, they represent the first ‘line’ of drug target development in cancer treatment. We propose that our newly identified kinase could be a successful and life-saving drug target for the progression of various types of cancer.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S3-7.

Identification and characterization of acidic mammalian chitinase inhibitors

Acidic mammalian chitinase (AMCase) is a member of the glycosyl hydrolase 18 family (EC 3.2.1.14) that has been implicated in the pathophysiology of allergic airway disease such as asthma. Small molecule inhibitors of AMCase were identified using a combination of high-throughput screening, fragment screening, and virtual screening techniques and characterized by enzyme inhibition and NMR and Biacore binding experiments. X-ray structures of the inhibitors in complex with AMCase revealed that the larger more potent HTS hits, e.g. 5-(4-(2-(4-bromophenoxy)ethyl)piperazine-1-yl)-1H-1,2,4-triazol-3-amine 1, spanned from the active site pocket to a hydrophobic pocket. Smaller fragments identified by FBS occupy both these pockets independently and suggest potential strategies for linking fragments. Compound 1 is a 200 nM AMCase inhibitor which reduced AMCase enzymatic activity in the bronchoalveolar lavage fluid in allergen-challenged mice after oral dosing.

Steep rise in notified hantavirus infections in Germany, April 2010

From January to April 2010, 396 hantavirus infections were notified in Germany, a considerable increase compared with previous years (mean: 83 for January-April 2004-2009) including the record-setting year, 2007 (n=232 January-April). Most patients are residents of known Puumala virus endemic areas in southern Germany. The recent increase in notified hantavirus infections is probably due to an increased population density of the main animal reservoir, the bank vole (Myodes glareolus).

Steep rise in notified hantavirus infections in Germany, April 2010

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