Quality of end-of-life cancer care in Canada: a retrospective four-province study using administrative health care data

BACKGROUND

The quality of data comparing care at the end of life (eol) in cancer patients across Canada is poor. This project used identical cohorts and definitions to evaluate quality indicators for eol care in British Columbia, Alberta, Ontario, and Nova Scotia.

METHODS

This retrospective cohort study of cancer decedents during fiscal years 2004-2009 used administrative health care data to examine health service quality indicators commonly used and previously identified as important to quality eol care: emergency department use, hospitalizations, intensive care unit admissions, chemotherapy, physician house calls, and home care visits near the eol, as well as death in hospital. Crude and standardized rates were calculated. In each province, two separate multivariable logistic regression models examined factors associated with receiving aggressive or supportive care.

RESULTS

Overall, among the identified 200,285 cancer patients who died of their disease, 54% died in a hospital, with British Columbia having the lowest standardized rate of such deaths (50.2%). Emergency department use at eol ranged from 30.7% in Nova Scotia to 47.9% in Ontario. Of all patients, 8.7% received aggressive care (similar across all provinces), and 46.3% received supportive care (range: 41.2% in Nova Scotia to 61.8% in British Columbia). Lower neighbourhood income was consistently associated with a decreased likelihood of supportive care receipt.

INTERPRETATION

We successfully used administrative health care data from four Canadian provinces to create identical cohorts with commonly defined indicators. This work is an important step toward maturing the field of eol care in Canada. Future work in this arena would be facilitated by national-level data-sharing arrangements.

Low birth weight is associated with adiposity, impaired skeletal muscle energetics and weight loss resistance in mice

BACKGROUND

In utero undernutrition is associated with obesity and insulin resistance, although its effects on skeletal muscle remain poorly defined. Therefore, in the current study we explored the effects of in utero food restriction on muscle energy metabolism in mice.

METHODS

We used an experimental mouse model system of maternal undernutrition during late pregnancy to examine offspring from undernourished dams (U) and control offspring from ad libitum-fed dams (C). Weight loss of 10-week-old offspring on a 4-week 40% calorie-restricted diet was also followed. Experimental approaches included bioenergetic analyses in isolated mitochondria, intact (permeabilized) muscle and at the whole body level.

RESULTS

U have increased adiposity and decreased glucose tolerance compared to C. Strikingly, when U are put on a 40% calorie-restricted diet they lose half as much weight as calorie-restricted controls. Mitochondria from muscle overall from U had decreased coupled (state 3) and uncoupled (state 4) respiration and increased maximal respiration compared to C. Mitochondrial yield was lower in U than C. In permeabilized fiber preparations from mixed fiber-type muscle, U had decreased mitochondrial content and decreased adenylate-free leak respiration, fatty acid oxidative capacity and state 3 respiratory capacity through complex I. Fiber maximal oxidative phosphorylation capacity did not differ between U and C but was decreased with calorie restriction.

CONCLUSIONS

Our results reveal that in utero undernutrition alters metabolic physiology through a profound effect on skeletal muscle energetics and blunts response to a hypocaloric diet in adulthood. We propose that mitochondrial dysfunction links undernutrition in utero with metabolic disease in adulthood.

Characterizing risk factors for pediatric lamp oil product exposures

Poisonings from lamp oil ingestion continue to occur worldwide among the pediatric population despite preventive measures such as restricted sale of colored and scented lamp oils. This suggests that optimal prevention practices for unintentional pediatric exposures to lamp oil have yet to be identified and/or properly implemented.

OBJECTIVE

To characterize demographic, health data, and potential risk factors associated with reported exposures to lamp oil by callers to poison centers (PCs) in the US and discuss their public health implications.

STUDY DESIGN

This was a two part study in which the first part included characterizing all exposures to a lamp oil product reported to the National Poison Data System (NPDS) with regard to demographics, exposure, health, and outcome data from 1/1/2000 to 12/31/2010. Regional penetrance was calculated using NPDS data by grouping states into four regions and dividing the number of exposure calls by pediatric population per region (from the 2000 US census). Temporal analyses were performed on NPDS data by comparing number of exposures by season and around the July 4th holiday. Poisson regression was used to model the count of exposures for these analyses. In the second part of this project, in order to identify risk factors we conducted a telephone-based survey to the parents of children from five PCs in five different states. The 10 most recent lamp oil product exposure calls for each poison center were systematically selected for inclusion. Calls in which a parent or guardian witnessed a pediatric lamp oil product ingestion were eligible for inclusion. Data on demographics, exposure information, behavioral traits, and health were collected. A descriptive analysis was performed and Fisher's exact test was used to evaluate associations between variables. All analyses were conducted using SAS v9.3.

RESULTS

Among NPDS data, 2 years was the most common patient age reported and states in the Midwestern region had the highest numbers of exposure calls compared to other regions. Exposure calls differed by season (p < 0.0001) and were higher around the July 4th holiday compared to the rest of the days in July (2.09 vs. 1.89 calls/day, p < 0.002). Most exposures occurred inside a house, were managed on-site and also had a "no effect" medical outcome. Of the 50 PC-administered surveys to parents or guardians, 39 (78%) met inclusion criteria for analysis. The majority of ingestions occurred in children that were 2 years of age, that were not alone, involved tiki torch fuel products located on a table or shelf, and occurred inside the home. The amount of lamp oil ingested did not appear to be associated with either the smell (p = 0.19) or the color of the oil (p = 1.00) in this small sample. Approximately half were asymptomatic (n = 18; 46%), and of those that reported symptoms, cough was the most common (n = 20, 95%) complaint.

CONCLUSIONS

Lamp oil product exposures are most common among young children (around 2 years of age) while at home, not alone and likely as a result of the product being in a child-accessible location. Increasing parental awareness about potential health risks to children from these products and teaching safe storage and handling practices may help prevent both exposures and associated illness. These activities may be of greater benefit in Midwestern states and during summer months (including the period around the July 4th holiday).

Tissue-specific splicing of a ubiquitously expressed transcription factor is essential for muscle differentiation

Alternate splicing contributes extensively to cellular complexity by generating protein isoforms with divergent functions. However, the role of alternate isoforms in development remains poorly understood. Mef2 transcription factors are essential transducers of cell signaling that modulate differentiation of many cell types. Among Mef2 family members, Mef2D is unique, as it undergoes tissue-specific splicing to generate a muscle-specific isoform. Since the ubiquitously expressed (Mef2Dα1) and muscle-specific (Mef2Dα2) isoforms of Mef2D are both expressed in muscle, we examined the relative contribution of each Mef2D isoform to differentiation. Using both in vitro and in vivo models, we demonstrate that Mef2D isoforms act antagonistically to modulate differentiation. While chromatin immunoprecipitation (ChIP) sequencing analysis shows that the Mef2D isoforms bind an overlapping set of genes, only Mef2Dα2 activates late muscle transcription. Mechanistically, the differential ability of Mef2D isoforms to activate transcription depends on their susceptibility to phosphorylation by protein kinase A (PKA). Phosphorylation of Mef2Dα1 by PKA provokes its association with corepressors. Conversely, exon switching allows Mef2Dα2 to escape this inhibitory phosphorylation, permitting recruitment of Ash2L for transactivation of muscle genes. Thus, our results reveal a novel mechanism in which a tissue-specific alternate splicing event has evolved that permits a ubiquitously expressed transcription factor to escape inhibitory signaling for temporal regulation of gene expression.

SU-E-T-269: The Evaluation of Copper as an Alternative for Cerrobend Electron Shielding

PURPOSE

To evaluate the replacement of Cerrobend by copper for electron beam cutouts.

METHODS

The dosimetric comparisons for circular copper-and Cerrobend-cutouts with diameters (1.0, 2.0, 3.0, 5.0, 7.5, 10.0, and 12.5 cm) were made using electron beams with energies (6, 9, 12, 16, and 20 MeV) from 3 Varian accelerators. A PTW Farmer chamber (0.125cc-volume) was used for larger cutouts (diameters > 2cm), and an electron-diode for the 2 smallest cutouts. Also a Markus parallel plate chamber was used.

RESULTS

(1) The tests showed little difference for the electron dosimetric characteristics, Eo, Eop, R50, Rp, and dmax. For larger cutout, the parameters were virtually the same for copper and Cerrobend. for smaller cutout (diameter = 3cm), small discrepancies were observed i.e. differences < 1mm for R50, Rp and dmax, =0.1MeV for Eop, and =0.3MeV for Eo. (2) The larger-cutout outputs at dmax were also virtually the same (difference = 0.6%). For smaller cutouts (diameters = 3cm), the copper outputs were 2.0%∼5.0% higher than Cerrobend. (3) For lower energy electrons (<12MeV), more larger-angle scattered electrons from higher-Z Cerrobend raise the Cerrobend percentage-depth-dose (PDD) curve at shallow-depths, and more forward scatter dose after dmax from lower-Z copper shifts the copper PDD slightly away from the one of Cerrobend. for higher energy electrons (= 12MeV), the shallow-dose difference becomes smaller for both cutouts, but even more forward-scattered dose from copper shifts copper's PDD further away from Cerrobend's. (4) The higher X-ray transmission through copper is also observable; i.e. 12%, 10%, and 7% for 20MeV, 16MeV, and 12MeV, respectively, but such small transmitted amount is clinically insignificant.

CONCLUSIONS

Except for a higher x-ray transmission, other dosimetric differences brought in by the replacement of Cerrobend by copper cutout are negligible.

Microtubule stability, Golgi organization, and transport flux require dystonin-a2-MAP1B interaction

Loss of interaction between the dystonin-a2 isoform and the microtubule-associated protein MAP1B induces microtubule instability and trafficking defects that may underlie certain neuropathies.

Loss of function of dystonin cytoskeletal linker proteins causes neurodegeneration in dystonia musculorum (dt) mutant mice. Although much investigation has focused on understanding dt pathology, the diverse cellular functions of dystonin isoforms remain poorly characterized. In this paper, we highlight novel functions of the dystonin-a2 isoform in mediating microtubule (MT) stability, Golgi organization, and flux through the secretory pathway. Using dystonin mutant mice combined with isoform-specific loss-of-function analysis, we found dystonin-a2 bound to MT-associated protein 1B (MAP1B) in the centrosomal region, where it maintained MT acetylation. In dt neurons, absence of the MAP1B–dystonin-a2 interaction resulted in altered MAP1B perikaryal localization, leading to MT deacetylation and instability. Deacetylated MT accumulation resulted in Golgi fragmentation and prevented anterograde trafficking via motor proteins. Maintenance of MT acetylation through trichostatin A administration or MAP1B overexpression mitigated the observed defect. These cellular aberrations are apparent in prephenotype dorsal root ganglia and primary sensory neurons from dt mice, suggesting they are causal in the disorder.

Cooperation between myogenic regulatory factors and SIX family transcription factors is important for myoblast differentiation

Precise regulation of gene expression is crucial to myogenesis and is thought to require the cooperation of various transcription factors. On the basis of a bioinformatic analysis of gene regulatory sequences, we hypothesized that myogenic regulatory factors (MRFs), key regulators of skeletal myogenesis, cooperate with members of the SIX family of transcription factors, known to play important roles during embryonic skeletal myogenesis. To this day little is known regarding the exact molecular mechanism by which SIX factors regulate muscle development. We have conducted a functional genomic study of the role played by SIX1 and SIX4 during the differentiation of skeletal myoblasts, a model of adult muscle regeneration. We report that SIX factors cooperate with the members of the MRF family to activate gene expression during myogenic differentiation, and that their function is essential to this process. Our findings also support a model where SIX factors function not only ‘upstream’ of the MRFs during embryogenesis, but also ‘in parallel’ to them during myoblast differentiation. We have identified new essential nodes that depend on SIX factor function, in the myogenesis regulatory network, and have uncovered a novel way by which MRF function is modulated during differentiation.

Drug resistance in the Chinese National Pediatric Highly Active Antiretroviral Therapy Cohort: implications for paediatric treatment in the developing world

China's National Pediatric ART Program began in 2005, in which 32 ART-experienced and 51 antiretroviral therapy (ART)-naïve children received paediatric formulations of (zidovudine or stavudine) plus lamivudine plus (nevirapine or efavirenz). Reverse transcriptase sequencing and analysis was performed on plasma samples with >1000 HIV copies/mL after one year of treatment. Thirty-four samples were sequenced. Nearly all patients had nucleoside reverse transcriptase inhibitor and non-nucleoside reverse transcriptase inhibitor mutations. High/intermediate resistance was found to lamivudine/emtricitabine in 31 patients; to didanosine, abacavir, stavudine and zidovudine in 18 patients; and to tenofovir in 11 patients. All had high-level resistance to nevirapine; all but one had high/intermediate-level resistance to efavirenz. Viral load was the only cohort characteristic significantly associated with developing resistance. Resistance to zidovudine, stavudine and tenofovir was more common in ART-experienced versus ART-naïve patients ( P = 0.02–0.05). Drug resistance is high in this cohort. Second-line therapy will require additional ART strategies and options, which are currently unavailable in most developing settings.

Separation of physical loading from photosynthesis/respiration processes in rivers by mass balance

Diurnal variations in physical and chemical concentrations, including nutrients, are observed in river ecosystems. Understanding these cycles and separating the effects of physical loading (from point and non-point sources) and biogeochemical processes are necessary for water management and the TMDL process. A chloride mass balance approach is used to separate the relative influences of physical loading and biogeochemical processes in the Bow River through Calgary, Canada, which has a significant influence on the river water chemistry. Sampling campaigns were conducted in December 2005, when minimal photosynthesis and respiration occur, and in July 2006, when river discharge is high and some photosynthesis and respiration activity is present. Samples in each campaign were collected at point source input and output along the river reach through the city every hour for a 24-hour period, allowing for time of travel. The two wastewater treatment facilities within the city contributed the majority of physical mass loading to the river, with temporal variations in effluent discharge, chloride, and nutrient concentrations. Wastewater effluent chloride to nutrient (as well as other parameter relationships) concentrations also varied diurnally. An hourly chloride mass balance was achieved, within 0.5% (average, S.D.=4.4) for December and 7.7% (average, S.D.=4.2) for July, between estimated cumulative sum values from all inputs and measured values at the river output downgradient of the city, allowing for the investigation of other parameter conservativeness. Some slight diurnal variations associated with photosynthesis and respiration were observed even with limited productivity in the river. Nitrate mass fluxes appeared to be most strongly influenced by photosynthesis and respiration processes, with phosphate being less influenced. Ammonia mass fluxes appeared to be most strongly influenced by wastewater effluent loading. Physical loading can mask or enhance biogeochemical diurnal fluctuations, creating errors in river process interpretations. Chloride was a useful tracer in the mass balance to distinguish between and assist in separating physical loading and biogeochemical processes in the river.

Intraepidermal animal-type melanoma

Animal-type melanoma is a rare variant of melanoma in humans.1 Its name is derived from its histological appearance, which is similar to that described in melanomas occurring in white or gray horses.2 All tumors are dermally located, and characterized by a proliferation of deeply pigmented elongated or rounded cells, showing moderate atypia and a low mitotic rate. In some tumors, secondary infiltration of the epidermis has been noted. More than half of the patients are younger than 30 years, and prognosis seems to be much better than that expected for a superficial spreading or nodular melanoma of the same size. We report the first case of animal-type melanoma in situ.

Estrogen-metabolizing gene COMT polymorphism synergistic APOE epsilon4 allele increases the risk of Alzheimer disease

Alzheimer disease (AD) is a polygenic multifactorial disorder. Several studies suggested that the neuroprotective effect of estrogen was based on an APOE-dependent mechanism. The goals of the current study were to determine if the genes involved in estrogen metabolism were linked to the risk of AD and find out if there was an interaction between estrogen-metabolizing gene polymorphisms and the APOE epsilon4 allele in the risk of prevalent AD. We investigated 66 patients with AD and 86 age- and gender-matched normal subjects. The polymorphisms of APOE and estrogen-metabolizing genes CYP17, CYP1A1 and COMT were examined. No association was found between each estrogen-metabolizing gene polymorphism and AD. However, the COMT HH genotype and APOE epsilon4 allele had a synergistic effect on the risk of AD. Taking subjects with epsilon4-epsilon4-/HH- as reference, the risk of developing AD in subjects with one epsilon4 allele (epsilon4+epsilon4-/HH-) was 2.6 (95% confidence interval, CI, 0.7- 9.1); however, the risk in subjects with both HH and one epsilon4 (epsilon4+epsilon4-/HH+) increased to 3.6 (95% CI 1.2-10.6). The subjects with homozygous epsilon4 still had the highest risk in developing AD (odds ratio 6.6, 95% CI 0.6-69.6). The p value of the linear trend test for this regression model was 0.004. It is possible that a high metabolism of estrogen by COMT may have reduced the protective effect of estrogen in AD. Further studies to clarify this interaction may improve our understanding of the generic risks for AD.

Multiple mechanisms promote the inhibition of classical nuclear import upon exposure to severe oxidative stress

In growing HeLa cells, severe stress elicited by the oxidant hydrogen peroxide inhibits classical nuclear import. Oxidant treatment collapses the nucleocytoplasmic Ran concentration gradient, thereby elevating cytoplasmic GTPase levels. The Ran gradient dissipates in response to a stress-induced depletion of RanGTP and a decreased efficiency of Ran nuclear import. In addition, oxidative stress induces a relocation of the nucleoporin Nup153 as well as the nuclear carrier importin-beta, and docking of the importin-alpha/beta/cargo complex at the nuclear envelope is reduced. Moreover, Ran, importin-beta and Nup153 undergo proteolysis upon oxidative stress. Caspases and the proteasome degrade Ran and importin-beta; however, ubiquitination of these transport factors is not observed. Inhibition of caspases in stressed cells alleviates the mislocalization of importin-beta, but does not restore the Ran concentration gradient or classical import. In summary, inhibition of classical nuclear import by hydrogen peroxide is caused by a combination of multiple mechanisms that target different components of the transport apparatus.