Does an electronic pathology ordering system change the volume and pattern of routine testing in hospital? An interrupted time series analysis

AIMS

Identifying and reducing low-value care is a vital issue in Australia, with pathology test ordering a common focus in this field. This study builds on previous research and aimed to quantify the impact of the implementation of an electronic ordering (e-ordering) system on the volume of pathology testing, compared with manual (paper based) ordering.

METHODS

An audit and analysis of pathology test data were conducted, using an interrupted time series design to investigate the impact of the e-ordering system on pathology ordering patterns. All medical and surgical adult inpatients at a tertiary referral hospital in Newcastle, Australia, were included over a 3-year period.

RESULTS

Overall, there were no statistically significant differences in the volume of orders due to the implementation of the e-ordering system. There was a slight increase in the aggregated volume (tests per admission and tests per bed day) of tests ordered across the entire study period, reflecting a secular trend.

CONCLUSIONS

Despite providing greater visibility and tracking of orders, we conclude that the implementation of an e-ordering system does not, in and of itself, reduce ordering volume. Efforts to identify and reduce low-value care will require intentional effort and specifically designed educational programmes or hard-wired algorithms.

Synthetic lethality of cytolytic HSV-1 in cancer cells with ATRX and PML deficiency

Cancers that utilize the alternative lengthening of telomeres (ALT) mechanism for telomere maintenance are often difficult to treat and have a poor prognosis. They are also commonly deficient for expression of ATRX protein, a repressor of ALT activity, and a component of promyelocytic leukemia nuclear bodies (PML NBs) that are required for intrinsic immunity to various viruses. Here, we asked whether ATRX deficiency creates a vulnerability in ALT cancer cells that could be exploited for therapeutic purposes. We showed in a range of cell types that a mutant herpes simplex virus type 1 (HSV-1) lacking ICP0, a protein that degrades PML NB components including ATRX, was ten- to one thousand-fold more effective in infecting ATRX-deficient cells than wild-type ATRX-expressing cells. Infection of co-cultured primary and ATRX-deficient cancer cells revealed that mutant HSV-1 selectively killed ATRX-deficient cells. Sensitivity to mutant HSV-1 infection also correlated inversely with PML protein levels, and we showed that ATRX upregulates PML expression at both the transcriptional and post-transcriptional levels. These data provide a basis for predicting, based on ATRX or PML levels, which tumors will respond to a selective oncolytic herpesvirus.

Summary: ATRX deficiency in cancer cells induces downregulation of PML, rendering the cells highly sensitive to lysis with ICP0-null mutant herpes simplex virus-1, with potential therapeutic applications.

Abstract A2-37: Predictive modeling to identify novel associations between gene amplification status and cancer cell line chemosensitivity

Background: Substantial research effort has been directed towards identifying gene amplification events during cancer development, with the view that these represent promising therapeutic targets or otherwise highlight pathways for therapeutic intervention. We considered whether datasets generated by recent large-scale pharmacogenomic studies (1, 2) could be mined to uncover novel associations between amplification status at particular genes of interest and cell line chemo-sensitivity or -resistance. As a case study, we examined the known amplification targets, ERBB2 and MYC, as well as a candidate amplification target, TPD52.

Experimental procedures: We accessed and curated datasets from the Cancer Cell Line Encyclopedia (1) and Cancer Therapeutics Response Portal (2). Multivariate linear regression modelling was performed to determine whether cell lines from diverse cancer types displayed differential responses to the same compound according to their gene copy number at ERBB2, MYC and TPD52. Associations between drug response and gene expression of ERBB2, MYC and TPD52 were also modelled to ascertain whether these recapitulated the gene-drug associations predicted by copy number. Both models were adjusted for cell lineage as a potential confounder by performing agglomerative hierarchical clustering of cell lines into 5 groups based on the 500 most highly varying genes. For each drug, chemo-sensitivity measures were discretised into three categories (resistant, intermediate and sensitive) using the waterfall method (1).

Results: Predictive modelling was possible for 24 drugs across 487 cell lines (1) and for an additional 323 drugs across 230 cell lines (2). Multivariate linear regression yielded 82 significant associations (p<0.05) between drug response and copy number at ERBB2 (n=57), MYC (n=20) or TPD52 (n=5). This included the known sensitization of ERBB2-amplified cell lines to lapatinib, which was the compound most significantly associated with both ERBB2 copy number and gene expression. We identified 9 novel associations between chemo-sensitivity and copy number at ERBB2 (n=1), MYC (n=3) or TPD52 (n=5), however, increased copy number was more frequently associated with resistance (n=72, p<0.05). Modelling also yielded 108 significant associations (p<0.05) between drug response and gene expression of ERBB2 (n=28), MYC (n=42) or TPD52 (n=38). However, there was limited concordance between drugs associated with copy number and those identified through gene expression; approximately 25% concordance for ERBB2 and MYC, and zero concordance for TPD52. Grouping cell lines by global expression profiles yielded a significant contribution to drug sensitivity in ~25% drug-gene associations, confirming cell lineage as a potential predictor of drug response. Taken together, these analyses identified several lead compounds for experimental validation in a cohort of TPD52-amplified cancer cell lines, with and without co-amplification of ERBB2 and/or MYC.

Conclusions: We have applied predictive models to data from large-scale pharmacogenomic studies (1, 2) to detect both known and novel associations between gene amplification status and cell line chemo-sensitivity or -resistance. Such analyses have the potential to link existing anti-cancer drugs with specific gene amplifications, which may then be applied as new biomarkers to predict efficacy.

References:

(1) Barretina et al 2012 Nature 483, 603

(2) Basu et al 2013 Cell 154, 1151

Citation Format: Sarah Frost, Erdahl Teber, Jennifer A. Byrne. Predictive modeling to identify novel associations between gene amplification status and cancer cell line chemosensitivity. [abstract]. In: Proceedings of the AACR Special Conference on Translation of the Cancer Genome; Feb 7-9, 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 1):Abstract nr A2-37.

Differential response of epiblast stem cells to Nodal and Activin signalling: a paradigm of early endoderm development in the embryo

Mouse epiblast stem cells (EpiSCs) display temporal differences in the upregulation of Mixl1 expression during the initial steps of in vitro differentiation, which can be correlated with their propensity for endoderm differentiation. EpiSCs that upregulated Mixl1 rapidly during differentiation responded robustly to both Activin A and Nodal in generating foregut endoderm and precursors of pancreatic and hepatic tissues. By contrast, EpiSCs that delayed Mixl1 upregulation responded less effectively to Nodal and showed an overall suboptimal outcome of directed differentiation. The enhancement in endoderm potency in Mixl1-early cells may be accounted for by a rapid exit from the progenitor state and the efficient response to the induction of differentiation by Nodal. EpiSCs that readily differentiate into the endoderm cells are marked by a distinctive expression fingerprint of transforming growth factor (TGF)-β signalling pathway genes and genes related to the endoderm lineage. Nodal appears to elicit responses that are associated with transition to a mesenchymal phenotype, whereas Activin A promotes gene expression associated with maintenance of an epithelial phenotype. We postulate that the formation of definitive endoderm (DE) in embryoid bodies follows a similar process to germ layer formation from the epiblast, requiring an initial de-epithelialization event and subsequent re-epithelialization. Our results show that priming EpiSCs with the appropriate form of TGF-β signalling at the formative phase of endoderm differentiation impacts on the further progression into mature DE-derived lineages, and that this is influenced by the initial characteristics of the cell population. Our study also highlights that Activin A, which is commonly used as an in vitro surrogate for Nodal in differentiation protocols, does not elicit the same downstream effects as Nodal, and therefore may not effectively mimic events that take place in the mouse embryo.

Symmetry of optic nerve head parameters measured by the heidelberg retina tomograph 3 in healthy eyes: the Blue Mountains Eye study

PURPOSE

To assess the symmetry of optic nerve head parameters measured by the Heidelberg Retina Tomograph 3 (HRT 3) between fellow eyes in a normal elderly population.

DESIGN

Cross-sectional population-based study.

METHODS

Participants of the Blue Mountains Eye Study 10-year follow-up who did not have optic disc disease, including glaucoma, were included. Optic nerve head parameters measured by HRT 3 were compared between fellow eyes. The normal range of interocular asymmetry (larger disc minus smaller disc) was determined by the 2.5th and 97.5th percentiles.

RESULTS

A total of 1276 eligible participants had HRT scans of both eyes. HRT measurements in right eyes differed slightly in rim steepness and rim volume from those in left eyes (P < .05). The 2.5th and 97.5th percentile of interocular asymmetry limits were -0.41 and 0.45 for cup-to-disc ratio and -0.19 and 0.22 for cup-to-disc area ratio, respectively. The highest interocular correlation was found in disc area and cup area (r ranged from 0.74-0.76), whereas mean cup depth, cup volume, and retinal nerve fiber layer thickness had the poorest correlation (r ≤ 0.07). Greater optic disc area asymmetry was associated with a larger interocular difference in the other optic nerve head parameters.

CONCLUSIONS

There was minimal interocular difference and substantial interocular correlation in optic nerve head parameters measured by HRT 3. Interocular asymmetry greater than 0.2 for cup-to-disc area ratio was considered outside the normal range.

Severity of age-related hearing loss is associated with impaired activities of daily living

BACKGROUND

age-related hearing loss is a common chronic condition; hence, it is important to understand its influence on the functional status of older adults. We assessed the association between hearing impairment with activity limitations as assessed by the activities of daily living (ADL) scale.

METHODS

a total of 1,952 Blue Mountains Hearing Study participants aged ≥60 years had their hearing levels measured using pure-tone audiometry. A survey instrument with questions on functional status as determined by the Older Americans Resources and Services ADL scale was administered.

RESULTS

one hundred and sixty-four (10.4%) participants reported ADL difficulty. A higher proportion of hearing impaired than non-impaired adults reported difficulties in performing three out of the seven basic ADL and six out of the seven instrumental ADL tasks. After multivariable adjustment, increased severity of hearing loss was associated with impaired ADL (P(trend )= 0.001). Subjects with moderate to severe hearing loss compared with those without, had a 2.9-fold increased likelihood of reporting difficulty in ADL, multivariate-adjusted odds ratio (OR): 2.87 [95% confidence interval (CI): 1.59-5.19]. Participants aged <75 years with hearing loss compared with those without, had 2-fold higher odds of impaired ADL. Having worn or wearing a hearing aid was also associated with a 2-fold increased likelihood of impaired ADL.

CONCLUSION

functional status as measured by a common ADL scale is diminished in older hearing impaired adults. Our findings suggest that severely diminished hearing could make the difference between independence and the need for formal support services or placement.

Exposure to workplace noise and the risk of cardiovascular disease events and mortality among older adults

BACKGROUND

We aimed to examine whether cross-sectional (prevalence) and longitudinal relationships (5-year incidence and 10-year mortality) exist between workplace noise exposure and cardiovascular diseases (CVD).

METHODS

2942 participants aged 55+years of the Blue Mountains Eye Study, Australia (1997-9 and 2002-4). Participants self-reported workplace noise exposure, hearing protector use and physician diagnosed CVD. CVD deaths were confirmed using the Australian National Death Index.

RESULTS

133 and 937 participants self-reported workplace noise exposure, and use or non-use of hearing protection devices, respectively. After multivariate adjustment, those who did not use hearing protection devices were 53% and 75% more likely to have prevalent CVD and angina, respectively, compared to those never exposed to workplace noise. Exposure to severe workplace noise for less than 1 to 5 years versus no exposure was associated with incident stroke OR 3.44 (95% CI 1.11-10.63). The mortality rate of CVD was 0.94% per year in people unexposed to workplace noise. Participants reporting less than 1 to 5 years versus those with no workplace noise exposure had a higher risk of CVD mortality, hazard ratio, HR, 1.60 (95% CI 1.10-2.33).

DISCUSSION

These data highlight the public health impact of workplace noise exposure on the vascular health of older adults.

Parental history of hypertension is associated with narrower retinal arteriolar caliber in young girls

We aimed to assess the associations between parental history of hypertension and indicators of cardiovascular risk (retinal vessel diameter, presence of obesity, and elevated blood pressure) in prepubertal children. There were 1739 (77.7% of those eligible) 6-year-old students (863 girls and 876 boys) who were examined from a random cluster sample of 34 Sydney schools. Parents completed questionnaires about their medical conditions, including whether they have/had hypertension. Retinal images were taken with a digital fundus camera, and retinal vessel caliber was quantified using computer software. Anthropometric (height, weight, percentage of body fat, and body mass index) and blood pressure measures were collected. There were 160 children (9.2%) with a positive parental history of hypertension (either biological mother and/or father). Children with a positive versus negative parental history of hypertension had significantly higher body mass index (16.8 versus 16.5 kg/m(2); P=0.04) and systolic blood pressure (101.3 versus 99.8 mm Hg; P=0.01). Girls with positive versus negative parental history of hypertension had significantly higher diastolic blood pressure (≈3.1 mm Hg; P=0.01) and narrower retinal arteriolar caliber (≈4.3 μm; P=0.0004). Positive parental history of hypertension was not associated with mean retinal vascular caliber among boys. We show that a positive parental history of hypertension in healthy prepubertal girls, but not boys, is associated with narrower retinal arteriolar vessels, likely conveying a predisposition to develop hypertension later in life. These findings may indicate the need for cardiovascular disease prevention measures starting early in life among offspring of hypertensive parents.

Dietary intake of cholesterol is positively associated and use of cholesterol-lowering medication is negatively associated with prevalent age-related hearing loss

We aimed to assess associations between dietary intake of fats (saturated and monounsaturated fats and cholesterol) and certain food groups (butter, margarine, and nuts) with the prevalence, incidence, and progression of age-related hearing loss. We also aimed to investigate the link between serum lipids and cholesterol-lowering medication (statins) and hearing loss. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss. Hearing loss was measured in 2956 participants (aged ≥50 y) and was defined as the pure-tone average (PTA) of frequencies 0.5, 1.0, 2.0, and 4.0 kHz > 25 dB hearing level (PTA(0.5-4 kHz)). Dietary data were collected using a semiquantitative FFQ. After multivariable adjustment, the likelihood of prevalent hearing loss increased from the lowest (reference) to the highest quartile of dietary cholesterol intake (P-trend = 0.04). Among persons self-reporting statin use (n = 274), a 48% reduced odds of prevalent hearing loss was observed after multivariable adjustment [OR = 0.52 (95% CI = 0.29-0.93)]. Participants in the second and 3rd quartiles of dietary monounsaturated fat intake compared with those in the first quartile (reference) had a significantly reduced risk of hearing loss progression 5 y later [multivariable-adjusted OR = 0.39 (95% CI = 0.21-0.71)] and [OR = 0.51 (95% CI = 0.29-0.91)], respectively. Our results suggest that a diet high in cholesterol could have adverse influences on hearing, whereas treatment with statins and consumption of monounsaturated fats may have a beneficial influence.

Influence of Physical Activity and Screen Time on the Retinal Microvasculature in Young Children

Objective—

It is not clear whether physical activity and sedentary behavior affect retinal microvascular caliber. We investigated associations among physical activity (outdoor and indoor sporting activities), sedentary behaviors (including screen time, television [TV] viewing, and computer and videogame usage), and retinal microvascular caliber in schoolchildren.

Methods and Results—

Six-year-old students (1765/2238) from a random cluster sample of 34 Sydney schools were examined. Parents completed questionnaires about physical and sedentary activities. Retinal images were taken, and retinal vessel caliber was quantified. After adjusting for age, sex, ethnicity, eye color, axial length, body mass index, birth weight, and mean arterial blood pressure, children who spent more time in outdoor sporting activities (in the highest tertile of activity) had 2.2 μm (95% CI 0.65 to 3.71) wider mean retinal arteriolar caliber than those in the lowest tertile ( P trend =0.004). Increasing quartiles of time spent watching TV were associated with narrower mean retinal arteriolar caliber ≈2.3 μm (95% CI 0.73 to 3.92), P trend =0.003.

Conclusion—

These data suggest that physical activity could have a beneficial influence, whereas screen time has a potential adverse influence on retinal microvascular structure. The magnitude of arteriolar narrowing associated with each hour daily of TV viewing is similar to that associated with a 10-mm Hg increase in systolic blood pressure in children.

Association between physical activity and blood pressure in prepubertal children

Elevated blood pressure (BP) during childhood and adolescence increases the risk of hypertension in later life. Although physical activity is known to positively moderate BP, data regarding this relationship are limited in prepubertal children. We aimed to assess the association between a range of physical activities (including indoor and outdoor activity) and BP in a large community-based sample of prepubertal schoolchildren. Eligible year-1 schoolchildren (n=1765; mean age 6.7 ± 0.4 years) from a random cluster sample of 34 schools in Sydney, Australia, were examined. Parents completed detailed questionnaires about their child's activity. Height and weight were measured, and body mass index (BMI) was calculated. BP was measured using a standard protocol, and elevated BP was defined using published guidelines. Physical activity was classified as low, medium or high (that is, as tertiles). After adjusting for age, sex, ethnicity, height, BMI, parental qualifications and family history of hypertension and/or cardiovascular disease, children in the highest tertile of outdoor and indoor activities had significantly lower diastolic BP (∼1.5 mm Hg; P(trend)=0.01) and systolic BP (∼1.3 mm Hg; P(trend)=0.03), respectively, compared with those in the lowest tertile (reference). Linearly, time spent in indoor activities (each hour per day) was associated with ∼2.4 mm Hg decrease in diastolic BP (P=0.001). Physical activity was independently associated with lower BP in this sample of prepubertal children. The findings emphasize the importance of ensuring regular physical activity programs in primary schools to potentially reduce the risk of elevated BP in childhood and in later life.

Effect of obesity on retinal vascular structure in pre-adolescent children

OBJECTIVES. In adults, obesity is linked to changes in the retinal microvasculature. Limited research has been conducted into this association in children. We examined in a cohort of pre-adolescents the relationship between body mass index (BMI) and retinal vascular structure, including retinal vessel diameter and retinal vessel fractals, a measure of geometric patterns reflecting vessel density.

METHODS

A population-based study among school children (2 353/3 144 [75.3%], median age, 12.7 years) recruited from a random cluster sample of 21 schools was conducted during 2004-5. Retinal images were taken and vessel diameter and fractal dimension were quantified using computer-based programs following standardized protocols. Anthropometric measures (weight, height, waist circumference, and BMI) were obtained and defined using standardized protocols.

RESULTS

Children with the highest quartile of BMI had narrower retinal arteriolar diameter (2.8 μm narrower, p<0.0001) and wider venular caliber (4.2 μm wider, p=0.001) than those with BMI in the lowest quartile, after adjusting for age, sex, ethnicity, mean arterial blood pressure, iris color, axial length, birth weight and fellow retinal vessel caliber. Obese children had narrower retinal arteriolar diameter (2.8 μm narrower, p=0.01) and wider venular diameter (4.5 μm wider, p=0.01) than in non-overweight/obese children. Retinal fractal dimension was not significantly associated with BMI. Increasing quartiles of waist circumference were also associated with retinal vessel diameter.

CONCLUSIONS

Our data provide evidence of adverse retinal microvascular caliber changes in obese pre-adolescent children, well before the onset of metabolic and cardiovascular disease in adulthood, and support an early, generalized adverse effect of adiposity on microvascular structure.

Identification of cellular changes associated with increased production of human growth hormone in a recombinant Chinese hamster ovary cell line

A proteomics approach was used to identify the proteins potentially implicated in the cellular response concomitant with elevated production levels of human growth hormone in a recombinant Chinese hamster ovary (CHO) cell line following exposure to 0.5 mM butyrate and 80 microM zinc sulphate in the production media. This involved incorporation of two-dimensional (2-D) gel electrophoresis and protein identification by a combination of N-terminal sequencing, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry, amino acid analysis and cross species database matching. From these identifications a CHO 2-D reference map and annotated database have been established. Metabolic labelling and subsequent autoradiography showed the induction of a number of cellular proteins in response to the media additives butyrate and zinc sulphate. These were identified as GRP75, enolase and thioredoxin. The chaperone proteins GRP78, HSP90, GRP94 and HSP70 were not up-regulated under these conditions.