Lung imaging in rodents using dual energy micro-CT

Dual energy CT imaging is expected to play a major role in the diagnostic arena as it provides material decomposition on an elemental basis. The purpose of this work is to investigate the use of dual energy micro-CT for the estimation of vascular, tissue, and air fractions in rodent lungs using a post-reconstruction three-material decomposition method. We have tested our method using both simulations and experimental work. Using simulations, we have estimated the accuracy limits of the decomposition for realistic micro-CT noise levels. Next, we performed experiments involving ex vivo lung imaging in which intact lungs were carefully removed from the thorax, were injected with an iodine-based contrast agent and inflated with air at different volume levels. Finally, we performed in vivo imaging studies in (n=5) C57BL/6 mice using fast prospective respiratory gating in end-inspiration and end-expiration for three different levels of positive end-expiratory pressure (PEEP). Prior to imaging, mice were injected with a liposomal blood pool contrast agent. The mean accuracy values were for Air (95.5%), Blood (96%), and Tissue (92.4%). The absolute accuracy in determining all fraction materials was 94.6%. The minimum difference that we could detect in material fractions was 15%. As expected, an increase in PEEP levels for the living mouse resulted in statistically significant increases in air fractions at end-expiration, but no significant changes in end-inspiration. Our method has applicability in preclinical pulmonary studies where various physiological changes can occur as a result of genetic changes, lung disease, or drug effects.

Measurement of long lived radioactive impurities retained in the disposable cassettes on the Tracerlab MX system during the production of [18F]FDG

Using a High- Purity Germanium gamma-ray spectrometer, a number of radioisotopes have been identified within Tracerlab MX radiochemistry system cassettes used to synthesise [18F]FDG. Twenty radiochemistry cassettes were measured and the average total activity of each radioisotope was determined. Using these values and decay correction, the minimum time the cassettes should be left in a decay store before the specific activity falls below 0.4B q/g, the limit for disposal alongside Clinical Waste was found to be 24 months.

An atypical case of successful resuscitation of an accidental profound hypothermia patient, occurring in a temperate climate

Cases of accidental profound hypothermia occur most frequently in cold, northern climates. We describe an atypical case, occurring in a temperate climate, where a hypothermic cardiac—arrested patient was successfully resuscitated using extracorporeal circulation (ECC).

Expression of the DNA repair enzyme, photolyase, in developmental tissues and larvae, and in response to ambient UV-R in the Antarctic sea urchin Sterechinus neumayeri

Gene expression of the DNA repair enzyme, photolyase (E.C. 4.1.99.3) was examined in the gonads, eggs, embryos and larval stages of the Antarctic sea urchin, Sterechinus neumayeri. Partial sequencing of the gene revealed two highly conserved regions, including a 300 bp region representing the binding site for the cofactor flavin adenine dinucleotide. The second 1200 bp region, likely representing a second light-harvesting cofactor binding site, was identified in a second sea urchin species, Strongylocentrotus frascicanus. Probes for photolyase were developed from the shorter sequence, and expression in sea urchin developmental tissue and stages, and in response to in situ exposure to ultraviolet radiation was quantified using PCR and RT-qPCR, with concentrations of photolyase normalized to actin concentrations. Photolyase was expressed in all tissues and developmental stages examined. In controlled field-based experiments in McMurdo Sound, Antarctica, we found evidence of both constitutive expression of photolyase and induction in response to in situ exposure of embryos to UV-R. Induction of photolyase was observed in response to greater ambient UV-R (such as shallower water depths or sea ice-free regions).

The total hospital and community UK costs of managing patients with relapsed breast cancer

The complete hospital and community records of 77 women were randomly selected from 232 women who had relapsed breast cancer between 2000 and 2005. Scrutiny of all management activities revealed a total cost of £1 939 329 (mean per patient of £25 186, 95% CI £13 705–£33 821). The median survival from time of relapse was 40.07 months and the median total cost per patient was £31 402.62. Including the community cost of a relapse provides a more realistic figure for future cost-effectiveness analysis of adjuvant breast cancer therapies.

Utilising cardiopulmonary bypass for cancer surgery. Malignancy-induced protein C deficiency and thrombophilia

Cardiopulmonary bypass has evolved over the last 30 years. It is an important tool for the cardiac surgeon today and also has applications in non-cardiac operations such as surgery to extract tumours. Such patients undergoing surgery for cancer may be at an increased risk of a thromboembolic event post surgery, due to disturbances in the normal clotting pathway leading to hypercoagulability. One such disturbance is malignancy-induced Protein C deficiency. A deficiency of Protein C can cause hypercoagulabitity. Recent studies have examined cardiopulmonary bypass and inherited Protein C deficiency. However, surgery for cancer patients with a malignancy-induced Protein C deficiency involving cardiopulmonary bypass has not been reported. Surgery using CPB in these patients may result in increased morbidity and mortality. The objective of this article is to review the literature in order to discuss the occurrence, the aetiology and possible management of cancer patients with malignancy-induced Protein C deficiencies that require cardiopulmonary bypass for their surgery.

Transcranial Doppler ultrasonography-directed intravenous glycoprotein IIb/IIIa receptor antagonist therapy to control transient cerebral microemboli before and after carotid endarterectomy

BACKGROUND

Patients with a transient focal neurological deficit, critical carotid stenosis and/or microemboli detected by transcranial Doppler ultrasonography (TCD) have a significant risk of stroke. The effect of tirofiban, a selective glycoprotein IIb/IIIa inhibitor, was assessed in patients with microembolic signals on TCD after transient ischaemic attacks or carotid endarterectomy (CEA).

METHODS

Thirty-three patients with microemboli on TCD (13 symptomatic preoperative, 19 postoperative, one both) were treated with tirofiban between 2002 and 2007. All patients had carotid stenosis greater than 70 per cent. TCD monitoring was used during and after tirofiban therapy.

RESULTS

The median (range) rate of microemboli decreased from 22 (4-260) per h before surgery and 81 (44-216) per h after surgery to 0 (0-9) per h in both groups (P < 0.001, Mann-Whitney U test). This occurred rapidly (preoperative median 30 min; postoperative median 45 min) and was well tolerated in all patients, with no serious adverse effects.

CONCLUSION

Cerebral microemboli were controlled by tirofiban both before and after CEA. Further study is required to compare the relative efficacy of tirofiban and dextran.

Switching to letrozole or exemestane improves hot flushes, mood and quality of life in tamoxifen intolerant women

We report an open-label, prospective, crossover study involving 184 post-menopausal women experiencing hot flushes on adjuvant tamoxifen (T). Six weeks after switching to an AI, the primary end point, hot flush score, improved by 47.3% (P<0.001) compared to those reported on T. The mean mood rating scale (MRS) score improved by 9.7% (P=0.01). The total mean combined FACT (b+es) score improved from 134.2 (95% CI +/-2.96) to 143.5 (95% CI +/-2.96 <0.001), and the endocrine subscale improved by 9.8% from 51.73 (95% CI +/-1.38) to 57.34 (CI +/-1.38, P<0.001). At 6 weeks, significantly more women chose to remain on an AI: 133 (72%), vs 40 (22%) (P<0.001) preferring T. At 3 months, 107 (58%) preferred to remain on an AI, 55(30%) on T, and 22 (12%) withdrew. The overall arthralgia rate at 3 months was 47% on AI and 30% on T (P=0.001). In all 182 (99%) women reported appreciating the opportunity to experience both drugs. These data suggest that if patients suffering significant adverse effects on T are given the opportunity to try an AI, this empowers them to prioritize relative side-effects, improving wellbeing in a significant proportion. These data also highlight the need for hospital follow-up in this intolerant cohort.