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.

Topography and soil properties contribute to regional outbreak risk variability of common voles (Microtus arvalis)

Context Common voles (Microtus arvalis) are the most common vertebrate pests in central European agriculture. During outbreaks common vole populations can increase to an enormous number of individuals; however, this outbreak risk varies regionally. Aims In this study we tested whether topography and soil properties are suited to explain the regional variability in the outbreak risk of the common vole in Eastern Germany. This study provides the first detailed large-scale study of the association of site characteristics and small mammal outbreak risk at a regional scale. Methods Data on common vole outbreaks were recorded by active burrow counts at 82 sampling sites in Eastern Germany from almost four decades. Data on topography and soil properties – i.e. groundwater fluctuation index, soil air capacity, saturated hydraulic conductivity, soil class and elevation – were obtained from soil maps and a digital elevation model in a geographic information system and were related to outbreak risk classes, applying classification and regression trees (CART). Based on these results a map of the outbreak risk was developed for the area. Key results Classification and regression tree analyses revealed that the mean elevation, area-related percentage of Chernozem soils and soil air capacity were the site characteristics best suited to explain local variability in outbreak risk. In the northern German lowland, below an elevation of ~83 m above sea level, the outbreak risk is generally very low. The region of the central upland has an increased risk for outbreaks of common voles. Within the region of the central uplands the risk was again elevated if the area covered by Chernozem soils was higher than 36%, and increased further if the area covered by soils with a moderate soil air capacity was higher than 90%. Conclusions Topography and soil properties, and accordingly the character of a landscape, are static parameters that affect the local risk of common vole outbreak. Further detailed field investigations of soil properties are required to link the variation in regional outbreak risk to site characteristics with relevance to common vole ecology. Implications Areas of varying regional outbreak risk of common voles can be defined according to static site characteristics identified in this study. They can provide a spatial framework to relate dynamic parameters, such as meteorological parameters, as well as biological parameters, such as food availability, to common vole outbreaks. This could be used in the future to develop improved predictive models to forecast common vole outbreaks.

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.

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

Binary file ES_Abstracts_Final_ECDC.txt matches

Efficacy and attractiveness of zinc phosphide bait in common voles (Microtus arvalis)

BACKGROUND

Minimising the concentration of active ingredient in rodenticide bait is desirable economically and for the protection of the agroecosystem. This study aimed to identify a zinc phosphide concentration that balances palatability and efficacy for common vole (Microtus arvalis Pall.) management and to compare the attractiveness of two bait carriers.

RESULTS

Bait uptake of voles was reduced by 87-98% compared with plain bait when bait contained 0.4-3.2% zinc phosphide. There was an almost 50% decrease in the uptake of zinc phosphide when the zinc phosphide concentration of bait was doubled. Red dye used in commercially available bait decreased bait consumption by 10%. Daily consumption of zinc phosphide bait on days 2 to 5 was half the consumption on the first day of exposure. In bait choice tests, wheat kernels were preferred initially, but within 12 h similar amounts of wheat-based pellets and wheat kernels were eaten.

CONCLUSIONS

According to the results from the laboratory trial, a zinc phosphide concentration of 2.1% seemed to balance uptake/efficacy best and may be most appropriate for the management of common vole populations. This concentration is substantially lower than the concentration used in many registered products. A reduced concentration of active ingredient and the use of pellet bait instead of wheat which is highly attractive for birds may have advantages for agroecosystem health when applying zinc phosphide for rodent control.

Ecologically based management of rodents in lowland irrigated rice fields in Indonesia

Context. Overabundant rodents cause considerable crop damage and, in developing countries of South-east Asia, rodents can be an obstacle to attempts at alleviating poverty. Management is often based on the use of chemicals that can harm non-target species. Therefore, an effective and environmentally benign management approach such as ecologically based rodent management (EBRM) is desirable. Aims. We compared the effectiveness of EBRM to that of conventional management on populations of rice-field rats (Rattus argentiventer). Methods. The study was conducted as a large-scale replicated field trial in lowland irrigated rice fields in West Java, Indonesia. EBRM actions included habitat manipulations, removal of rats with trap barrier systems, coordinated rat-control campaigns and synchrony of cropping on the village level. We measured abundance, population structure, and breeding of rice-field rats as well as rice production and crop damage caused by rats. Key results.Although there was no overall effect of the EBRM treatment on rat abundance, we found decreasing rat abundance in rice-field habitats at the late cropping stage in treated villages and a decrease in body size of rats. In addition, we found fewer reproducing females when EBRM was applied than with the application of conventional methods, whereas male reproductive condition did not decrease. Overall, there was a reduction in mean crop damage when EBRM was applied (4.4 ± 0.4% in treatments v. 2.5 ± 0.4% in experimental controls), which translated into 6% higher rice production. Conclusions. The results demonstrated that EBRM is an appropriate approach to manage overabundant rodents in irrigated lowland rice-based agro-ecosystems and possibly in other agro-ecosystems. This will provide substantial benefits for smallholder farming communities in developing countries and most likely benefits for ecosystem health. Implications. The EBRM approach should be used routinely in irrigated lowland rice crops that are at risk of damage by rice-field rats.

Hyperosmolar hyperglycemic non ketotic coma and rhabdomyolysis; an uncommon clinical encounter

Rhabdomyolysis is usually attributed to trauma. However there is an association of rhabdomyolysis with hyperosmolar states. Recognition of this association will enable better management of the patient and reduce the burden on the care taker by preventing the onset of complications that can prove fatal. It is also important to realise that hyperosmolar coma can be the presenting complaint of a diabetic seeking medical attention for the first time.