A comparison of two digital mammography systems: are there any differences?

AIM: To compare the performance of two newly introduced digital mammography technologies (Sectra and Hologic) to the Welsh breast-screening service; specifically, whether there are differences in the number, type, size, and grade of tumour identified. MATERIALS AND METHODS: This was a retrospective study of a prospectively collected database of 50,000 consecutive screening episodes from 2012; clients were aged 49-88 years (mean 61.9 years). All studies were double-blind read by two readers. All tumours identified in the two arms of the study were detailed and compared specifically with regards to type (ductal or lobular) size, grade, and whether invasive or non-invasive. Performance was analysed for any statistically significant differences. RESULTS: Twenty-five thousand consecutive women were screened with Hologic (recall rate 5.9% of which 18% were cancer) and 25,000 were screened with Sectra digital mammography (recall rate 4.3% and 22% were cancer). Five hundred tumours were found with no significant difference in invasive cancer detection or between ductal or lobular subtypes. The Hologic system detected 267 tumours; of which 81 (30.33%) were non-invasive (3.24 per 1000), compared to the Sectra system with 233 cancers overall including 36 non-invasive (15.45%, 1.44 per 1000). The difference in non-invasive lesions (mainly ductal carcinoma in situ [DCIS]) detection was significant (p<0.001); 38% of which were high nuclear grade (HNG) using Hologic and 50% HNG lesions using Sectra. There was no significant difference in non-invasive size between the two technologies. The mean glandular dose received using the Sectra system was significantly less (0.7 mGy) compared to the Hologic system (1.6 mGy) for a 50-60 mm breast thickness. CONCLUSIONS: Population breast screening is frequently criticised for identifying lesions irrelevant to long-term outcomes or life expectancy and although the two systems seem comparable in terms of invasive cancer detection, a statistically significant difference in the detection of non-invasive lesions was seen, not reported in previous studies. This is a contentious issue, as identifying more DCIS has the potential to over-diagnose screened women leading to increased morbidity, higher "cancer detection rates", longer cancer waiting times, and reduced patient psychological wellbeing. The Sectra system is able to deliver a similar invasive detection cancer delivering a much lower dose mammogram, which is important in limiting overall population radiation dose. Further study as to whether the differences in tumour detection rates are clinically significant long term are now required.

Evaluation of a permeable reactive barrier to capture and degrade hydrocarbon contaminants.

A permeable reactive barrier (PRB) was installed during 2005/2006 to intercept, capture and degrade a fuel spill at the Main Power House, Casey Station, Antarctica. Here, evaluation of the performance of the PRB is conducted via interpretation of total petroleum hydrocarbon (TPH) concentrations, degradation indices and most probable number (MPN) counts of total heterotroph and fuel degrading microbial populations. Results indicate that locations which contained the lowest TPH concentrations also exhibited the highest levels of degradation and numbers of fuel degrading microbes, based on the degradation indices and MPN methods selected. This provides insights to the most appropriate reactive materials for use in PRB's in cold and nutrient-limited environments.

Reduction in interval cancer rates following the introduction of two-view mammography in the UK breast screening programme.

BACKGROUND: The introduction of two-view mammography at incident (subsequent) screens in the National Health Service Breast Screening Programme (NHSBSP) has led to an increased number of cancers detected at screen. However, the effect of two-view mammography on interval cancer rates has yet to be assessed. METHODS: Routine screening and interval cancer data were collated from all screening programmes in the United Kingdom for women aged 50-64, screened between 1 April 2003 and 31 March 2005. Interval cancer rates were compared based on whether two-view mammography was in use at the last routine screen. RESULTS: The reduction in interval cancers following screening using two-view mammography compared with one view was 0.68 per 1,000 women screened. Overall, this suggests the introduction of two-view mammography at incident screen was accompanied by a 15-20% reduction in interval cancer rates in the NHSBSP. CONCLUSION: The introduction of two-view mammography at incident screens is associated with a reduction in incidence of interval cancers. This is consistent with previous publications on a contemporaneous increase in screen-detected cancers. The results provide further evidence of the benefit of the use of two-view mammography at incident screens.

Evaluation of healing by gentle touch.

OBJECTIVES: To evaluate the effectiveness and safety of healing by gentle touch in clients attending The Centre for Complementary Care (CCC) in Eskdale, Cumbria. STUDY DESIGN: An evaluation of data collected by questionnaire over 6 years. METHODS: All clients attending the CCC between 1995 and 2001 were invited to participate in this study, and data were collected from 300 subjects with a wide range of ailments who received four treatment sessions within 6 weeks. Exclusion criteria were: recent treatment at the CCC; failure to complete four treatment sessions; and age under 16 years. Outcome measures included comparison of pre- and post-treatment levels of physical (pain, disability, immobility, sleep disturbances, reliance upon medication, daily activities) and psychological (stress, panic, fear, anger, relaxation, coping, depression/anxiety) functioning; these were assessed using a questionnaire with visual analogue scales for subjective rating of symptoms and the EuroQoL (EQ-5D), a generic state-of-health measure. RESULTS: Wilcoxon signed ranks tests showed statistically significant improvements in both psychological and physical functioning, particularly in stress reduction (median stress levels fell by four points), pain relief (median pain ratings fell by two points), increased ability to cope (median improvement of three points) and increased general health ratings (median improvement of 20 points) between study entry and end of treatment (P < 0.0004 for all these symptoms). The most substantial improvements were seen in those with the most severe symptoms at study entry. No adverse effects of treatment were documented. CONCLUSIONS: This audit of treatment outcomes provides evidence consistent with the hypothesis that healing, as provided at the CCC, was associated with improved psychological and physical functioning in the majority of subjects, and is worthy of further evaluation.

Locomotor effects in sheep of alkaloids identified in Australian Tribulus terrestris.

Fresh, mature, ungrazed Tribulus terrestris plant material was subjected to a standard alkaloid extraction procedure. The extract was fractionated by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Two major alkaloid fractions were demonstrated. These fractions were identified by means of TLC, ultraviolet spectrofluorimetry (UVS) and HPLC, as the beta-carboline indoleamines harmane and norharmane. The extractable alkaloid content was determined to be 44 mg/kg dry matter. Synthetic harmane and norharmane were administered subcutaneously to sheep at a dose rate of 54 mg/kg. Both compounds caused similar nervous effects. The main effect observed was limb paresis, which in some sheep was body side blased. The clinical signs observed in the experimental sheep were consistent with those described for naturally occurring cases of Tribulus terrestris staggers. It was proposed that harmane and norharmane accumulate in tryptamine-associated neurones of the central nervous system, during months of tribulus ingestion, and gradually interact irreversibly with a specific neuronal gene DNA sequence.

Ifosfamide-induced Fanconi's syndrome with growth failure in a 2-year-old child.

Fanconi's syndrome with phosphopenic rickets is described in a 2-year-old girl who had been treated for an embryonal sarcoma with multiagent chemotherapy including high-dose ifosfamide. The radiological and biochemical signs of rickets disappeared after treatment with 25-OH vitamin D3 and phosphorus supplements. Monitoring of tubular function in children during and after treatment with ifosfamide is mandatory.

Role of glutathione peroxidase in the radiation response of mouse kidney.

Glutathione peroxidase (GSH-Px) has been implicated in mediating the radioprotective effects of glutathione (GSH). This hypothesis was tested in vivo by determining the effect of GSH-Px depletion on the radiation response of murine kidneys. Renal GSH-Px levels were depleted to 17% of control values by feeding animals a selenium deficient diet for 6 weeks; this had no significant effect on renal levels of GSH or GSH-S-transferase (GST). However, we also tested the effect of direct depletion of GSH to 3-4% of control values, using a combination of DL-buthionine sulphoximine (BSO) and diethyl maleate (DEM). Kidneys with normal or depleted levels of GSH-Px and/or GSH were irradiated with 240kVp X rays (2 fractions, 7 days apart to minimize intestinal injury). Mice breathed 7% oxygen during irradiation. Renal damage was assessed at 20, 25, and 32 weeks after the first fraction of X rays, in terms of reduced hematocrit and renal clearance of 51Cr-EDTA. Depletion of GSH-Px levels to 17% of control did not alter renal radiosensitivity, but depletion of GSH to 3-4% of control values radiosensitized the kidney by a factor of 1.4. Depletion of both GSH and GSH-Px together did not radiosensitize the kidney any more than was achieved by GSH depletion alone.

Antitumor imidazotetrazines. 14. Synthesis and antitumor activity of 6- and 8-substituted imidazo[5,1-d]-1,2,3,5-tetrazinones and 8-substituted pyrazolo[5,1-d]-1,2,3,5-tetrazinones.

The systematic variation of the potent antitumor agent mitozolomide (1) is extended to cover alteration of substituents at positions 6 and 8 and to change the imidazo[5,1-d]-1,2,3,5-tetrazinone (1) skeleton to the isomeric pyrazolo-[5,1-d]-1,2,3,5-tetrazinone (17) skeleton. The series of eight 6-alkyl and 6-aralkyl derivatives of 1 showed optimal antitumor activity when the group was small or linear, but activity diminished as size and branching of this substituent increased. This may reflect altered transport characteristics, or failure of the enlarged derivatives to fit a binding site, or possibly a reduced tendency for the derivatives having bulky groups at position 6 to hydrolytically generate the putatively active triazenes (21). Testing of 14 derivatives of 1 differently substituted at position 8 revealed a complex structure-activity relationship, with good antitumor activity obtained for carbamoyl and sulfamoyl groups bearing small substituents. The 8-methylsulfonyl compound had noteworthy activity, but the 8-cyano, 8-nitro, and 8-phenyl derivatives were devoid of useful antitumor activity in these tests. From the limited number of pyrazolotetrazinones (17) reported here, it is suggested that the same conclusions as regards activity also hold true for this ring system.

Pulmonary excretion rates of carbon monoxide using a modified technique: differences between premature and full-term infants.

The pathophysiology of the exaggerated hyperbilirubinemia in premature infants remains unclear. The relative contribution of bilirubin production may be estimated by measuring the pulmonary excretion rate of carbon monoxide (VeCO). We found that the mean VeCO of premature infants, 16.7 +/- 5.0 microliters/kg/h, was significantly elevated (p less than 0.05) compared with the mean VeCO of full-term infants, 13.9 +/- 3.5 microliters/kg/h. Premature infants who required phototherapy had a significantly (p less than 0.05) higher mean VeCO than those who did not. The VeCO did not correlate with gestational age, implying that factors which associate frequently but variably with gestational age may have an important influence on heme catabolism.

Particle size and protein content of six fractions of the Sf 20 plasma lipoproteins isolated by density gradient centrifugation.

A procedure is described for the separation of plasma S(f) > 400 and S(f) 20-400 lipoproteins each into three fractions. Serum samples are overlayered with a sodium chloride density gradient in a preparative ultracentrifuge tube and thin layers are removed at the top of the tube after successive centrifugations at different speeds in a swinging bucket rotor. The procedure was evaluated by electron microscopy of the S(f) > 400 lipoprotein fractions and schlieren analysis of the S(f) 20-400 lipoprotein fractions. Protein content of each fraction was measured by elemental N, C, H, and lipid-P analysis. Protein coverage was calculated for all fractions on the assumption that there is a surface layer 20 A thick. For the entire S(f) > 400 lipoprotein spectrum and for a part of the S(f) 20-400 lipoprotein distribution the proportion of surface covered by protein was constant (approximately 20% coverage). Therefore, for these portions of the lipoprotein spectrum, the increase in surface: volume ratio as particle size decreases is approximately compensated for by an increase in the weight percentage of protein.