RESPONSE OF DOSEMETERS IN FIELDS GENERATED BY LASER-ACCELERATED PROTONS

In laser-driven acceleration, ultra-short and intense laser pulses are focussed on targets to generate beams of ionising radiation. One of the most important issues to be addressed is personal monitoring. While traditional dosemeters were designed primarily for measurements in continuous fields, dosemeters for laser laboratories must be capable of working in pulsed fields of pulse length below 1 ps, in a single-shot regime up to the repetition rate of 1 kHz. Responses of conventional dosemeters (films, polyallyldiglycol carbonate, electronic personal dosemeter) to proton bunches of up to 30 MeV energy produced by South Korean PW laser system at the Advanced Photonics Research Institute, Gwangju Institute of Science and Technology were studied, both by means of Monte Carlo simulations and experimentally.

Quick-Wee: A Novel Non-Invasive Urine Collection Method for Infants in the Emergency Department

BACKGROUND: Urinary tract infection is one of the commonest paedi-atric infections, and important to diagnose or exclude in young children with fever. Limitations exist with all current urine collection methods, guidelines vary, and clinicians have different preferences. Clean catch urine (CCU) is a preferred non-invasive collection method and is convenient and painless compared to suprapubic aspirate and catheterisation. However, it can be unreliable and time-consuming, with high rates of sample contamination and collection failure. Only 12% void within 5 minutes based on recent data. An ideal method of urine collection would be fast, reliable and simple. Suprapubic stimulation may trigger involuntary parasympathetic detrusor contraction, inducing voiding via early childhood exteroceptive somato-bladder reflexes.

OBJECTIVES: We conducted a pilot study using a novel method (termed ‘Quick-Wee’) of gentle cutaneous suprapubic stimulation with saline-soaked gauze, to hasten voiding for non-invasive urine collection.

DESIGN/METHODS: Prospective pilot study of 40 pre-continent children age 1-24 months requiring CCU in a paediatric emergency department in Australia. Standard CCU was augmented by 5 minutes of suprapubic cutaneous stimulation (Quick-Wee method), with either cold (3 degrees Celsius) or room-temperature saline-soaked gauze. PRIMARY OUTCOME: Void <5 minutes. SECONDARY OUTCOMES: Successful catch of sample (if voids), contamination rate, parental/clinician satisfaction with technique.

RESULTS:

Urine Clean Catch Collection in the Paediatric Emergency Department: Success, Time to Void and Contamination Rates

BACKGROUND: Young children frequently require investigation for urinary tract infection (UTI). Clean catch urine (CCU) is a common urine collection method in pre-continent children but can be time consuming or unsuccessful, and contaminated cultures may lead to an inability to diagnose or exclude UTI. There are few data available examining the success and time required for CCU and factors influencing contamination. We hypothesise that time taken to obtain CCU influences contamination, due to accidental contamination during collection.

OBJECTIVES: To determine the time taken to obtain CCU in pre-conti-nent children, and if time to collection is related to the contamination rate.

DESIGN/METHODS: Prospective observational study of CCU collection in pre-continent children aged 2-48 months at a paediatric emergency department in Australia. A standardised CCU collection protocol was used. Primary outcome was time to first void; secondary outcomes were success of obtaining (catching) CCU and contamination of urine cultures obtained. Contamination was defined as per hospital microbiology standards. Descriptive analysis of time to void included median and interquartile range (IQR). We performed a regression analysis of key factors possibly related to contamination, including age, sex and time to collection.

RESULTS: Of the 218 recruited patients, 61% were male, mean age 11.4 months (SD 8.5). The main indication for CCU was: 128 fever of unknown origin (59%), 31 vomiting (14%), 27 specifically suspected UTI (12%), 32 other reason (15%). From first CCU attempt, 174 voided (80%) of which 139 were successful catches (64%) and 34 were missed on voiding (16%). 44 first CCU attempts were stopped before voiding (20%), 26 patients had 2 attempts (12%), and 2 patients had 3 CCU attempts (1%). Median time to first void was 25 minutes (IQR 8 – 49). 27 children (12%) voided <5 minutes, 33 (19%) voided >1hr. Of the 130 patients who had urine culture results available, 50 were contaminated (38%). There was no significant difference in contamination rate by age, sex or time to sample collection. Of 218 patients where ED clinicians set out to collect CCU in the emergency department, only 80 (37%) resulted in a successful CCU attempt with an uncontaminated culture.

CONCLUSION: Contamination rates are high in clean catch urine, but not related to the time taken for sample collection. CCU attempts are often unsuccessful, and have a low diagnostic yield for investigation of UTI in young children in clinical practice.

Short communication: Field study of air ammonia concentrations in Ontario dairy calf housing microenvironments

Kaufman, J., Linington, M., Osborne, V. R., Wagner-Riddle, C. and Wright, T. C. 2015. Short Communication: Field study of air ammonia concentrations in Ontario dairy calf housing microenvironments. Can. J. Anim. Sci. 95: 539–542. The objective of this study was to measure the ammonia concentrations in the microenvironment of the calf housing area on a sample of commercial dairies in Ontario under typical management conditions. Two approaches were used to measure ammonia concentrations: (1) weekly on four farms for a period of 8 wk and (2) one-time samples were taken from the calf areas on 15 other farms. The results indicated that ammonia levels are managed below the existing maximum threshold provided in the national dairy code of practice.

Severe Acute Anemia After Liver Transplantation in an Elderly Jehovah's Witness Treated With High-dose Erythropoietin and Ferric Carboxymaltose: A Case Report

BACKGROUND

There is no standard treatment for patients with severe anemia who refuse blood transfusion or cannot receive red blood cells.

CASE REPORT

After an orthotopic liver transplantation, an elderly Jehovah's Witness who refused blood transfusion presented with severe acute anemia with hemorrhagic shock. The calculated red blood cell loss was near 70%. Associated with surgical treatment and supportive measures, the patient was treated with high-dose erythropoietin and ferric carboxymaltose.

RESULTS

The patient presented a rapid increase in hemoglobin concentration and reticulocyte count with resolution of hemorrhagic shock after the proposed pharmacologic treatment combined with local hemostatic measures. She was transferred to a low-risk unit 4 days after transplantation and was discharged from the hospital on day 10. The hemoglobin concentration was normal 35 days after the bleeding event.

CONCLUSION

This case demonstrated that a protocol with high-dose erythropoietin and ferric carboxymaltose may be an option for patients with severe anemia who refuse blood transfusion or cannot receive red blood cells.

Similar Outcomes for Two Anemia Treatment Strategies among Elderly Hemodialysis Patients with Diabetes

BACKGROUND/AIMS

To compare mortality and cardiovascular risk in elderly dialysis patients with diabetes under two clinical strategies of anemia correction: maintaining hematocrit (Hct) between 34.5 and < 39.0% (high Hct strategy), and between 30.0 and <34.5% (low Hct strategy) using intravenous alpha epoetin.

METHODS

Observational data were used to emulate a randomized trial in which diabetic patients who initiated hemodialysis in 2006-2008 were assigned to each anemia correction strategy. Inverse-probability weighting was used to adjust for measured time-dependent confounding.

RESULTS

Comparing high with low hematocrit strategy, the hazard ratio (95% confidence interval) was 1.07 (0.83, 1.38) for all-cause mortality and 1.00 (0.81, 1.24) for a composite mortality and cardiovascular endpoint.

CONCLUSIONS

Among a cohort of elderly hemodialysis patients with diabetes, no differences were found between the low and high hematocrit strategies. A lower target hematocrit - per current Food and Drug Administration (FDA) guidelines - appears to be as safe as higher targets among this population.

Development and first experimental tests of Faraday cup array

A new type of Faraday cup, capable of detecting high energy charged particles produced in a high intensity laser-matter interaction environment, has recently been developed and demonstrated as a real-time detector based on the time-of-flight technique. An array of these Faraday cups was designed and constructed to cover different observation angles with respect to the target normal direction. Thus, it allows reconstruction of the spatial distribution of ion current density in the subcritical plasma region and the ability to visualise its time evolution through time-of-flight measurements, which cannot be achieved with standard laser optical interferometry. This is a unique method for two-dimensional visualisation of ion currents from laser-generated plasmas. A technical description of the new type of Faraday cup is introduced along with an ad hoc data analysis procedure. Experimental results obtained during campaigns at the Petawatt High-Energy Laser for Heavy Ion Experiments (GSI, Darmstadt) and at the Prague Asterix Laser System (AS CR) are presented. Advantages and limitations of the used diagnostic system are discussed.

Adverse myocardial effects of B-vitamin therapy in subjects with chronic kidney disease and hyperhomocysteinaemia

BACKGROUND & AIMS

Hyperhomocysteinaemia (HHCY), a common finding in patients with chronic kidney disease (CKD), has been shown to contribute to adverse cardiac remodelling and failure. We hypothesised that in human subjects with CKD, HHCY would be associated with myocardial dysfunction, and that homocysteine (HCY)-lowering therapy would improve myocardial remodelling and heart-failure (HF) outcomes.

METHODS AND RESULTS

Post hoc analysis of the Homocysteinemia in Kidney and End Stage Renal Disease (HOST) trial (n=2056) was performed to determine if HCY-lowering therapy with high dose B vitamins affects HF outcomes in patients with CKD. In addition, effects on myocardial remodelling were assessed in a subgroup of 220 trial subjects who had transthoracic echocardiograms done before study randomisation and during the course of the study as part of their routine clinical care. HF outcomes were not significantly affected by treatment compared to the placebo. HCY levels were inversely correlated with diastolic function (R=-0.21; p=0.038). Vitamin therapy resulted in a significant increase in left atrial size (+0.15±0.8 cm vs. -0.13±0.07 cm; p=0.0095). No other echocardiographic parameters were significantly associated with baseline HCY levels or changes with vitamin therapy.

CONCLUSION

HHCY is associated with diastolic dysfunction in patients with CKD. However, B-vitamin therapy did not improve HF outcomes despite lowering of plasma HCY levels, and was associated with an increase in left atrial size, which is a surrogate for worsening left ventricular diastolic dysfunction. These findings suggest that high-dose B vitamin therapy may be harmful in patients with CKD.

Abstract P6-04-12: Novel selective estrogen receptors degraders regress tumors in pre-clinical models of endocrine-resistant breast cancer

80% of all breast cancers express the estrogen receptor alpha (ERα) and thus are treated with anti-hormonal therapies that directly block ER function (e.g. Tamoxifen) or hormone synthesis (Aromatase Inhibitors). While these therapies are initially effective, acquired resistance invariably emerges. Importantly, the majority of these tumors continue to depend on ERα for growth and survival. The emerging evidence that ERα can signal in both a ligand-dependent and ligand-independent manner supports the development of agents that are not only competitive ERα antagonists but also reduce steady state levels of the receptor and thus limit both modes of signaling.

We have identified novel, non-steroidal ERα antagonists that induce degradation of ERα in breast cancer cell lines at picomolar concentrations resulting in significant reduction in steady state ERα protein levels. Using peptide-based conformational profiling, we show that these Selective Estrogen Receptor Degraders (SERDs) induce estrogen receptor conformations that are distinct from both fulvestrant and tamoxifen indicating a unique mechanism of action. This unique biological profile coupled with good oral pharmacokinetics produces tumor regressions in both tamoxifen-sensitive and -resistant models of breast cancer in vivo. Recent pre-clinical and clinical data indicate that PI3K pathway signaling can contribute to the endocrine resistant state. In a preclinical model of tamoxifen resistant breast cancer in which SERD monotherapy only produces tumor growth inhibition, SERD therapy in combination with torc1/2 inhibition results in frank tumor regressions. These orally bioavailable SERDs hold promise as a next generation therapy for the treatment of ER+ breast cancer as monotherapy, as well as in combination with agents that target other pathways involved in both intrinsic and acquired endocrine resistance.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-12.