A role for surgery in the treatment of relapsed Hodgkin lymphoma.

Treatment of Hodgkin lymphoma (HL) has advanced over time, rendering a fatal disease now largely curable. Multiagent chemotherapy regimens, hematopoietic stem cell transplantation, and radiotherapy are the mainstays of care. Surgical intervention is rarely indicated other than for biopsy at diagnosis. However, for patients with recurrent relapsed HL isolated to one anatomical location, refractory to all other therapy, there may be a beneficial role for surgical excision. Herein, we report the surgical management of three relapsed patients with stage IVB HL who were refractory to multiple other therapeutic approaches, who all achieved good event-free survival after operative management.

Understanding the healthcare experiences of teenaged cancer patients and survivors.

BACKGROUND: Despite literature supporting a client and family-centred approach to healthcare delivery in paediatric facilities, there is little information about healthcare delivery from the perspective of teenagers in the oncology setting. The objective of this study is to describe the healthcare experiences of teenagers with cancer. METHODS: As part of a larger study on teen-centred care delivery in paediatric oncology, a survey included several open-ended questions to learn about the following: (1) what teenagers liked about the cancer care they received; (2) what they disliked about the cancer care received; and (3) what they would include if they could design the perfect cancer centre for teenagers. The survey was completed by 200 teenagers (aged 12-20 years) from three paediatric hospitals in Canada. Answers to these questions were coded and developed into themes and subthemes using a thematic analysis approach. RESULTS: The number of patients providing answers was 89% for question 1, 63% for question 2 and 68.5% for question 3. Likes and dislikes were conceptualized in terms of four key themes as follows: (1) staff at the treatment centre; (2) the cancer care they received; (3) the treatment centre itself; and (4) social activities. The most common suggestions for the perfect cancer centre included having access to better entertainment, more social opportunities to interact with peers, and a more comfortable environment for themselves and their families. CONCLUSION: Understanding teenagers' experiences in the paediatric oncology setting provides information that could be used to shape the delivery of healthcare in a way that is tailored to their needs. Further research in this area is required in order to improve existing oncology care.

Caregiving, single parents and cumulative stresses when caring for a child with cancer.

BACKGROUND: Single parents whose children have cancer are a marginalized group who report less family centred care, and therefore, less quality cancer care for their children. As such, the aims of this study were to explore how single parents of children with cancer describe their caregiving experiences and to understand their contextual life stressors. METHODS: A constructivist grounded theory method was used. Qualitative interviews with 29 single parents of children with cancer who were at least 6 months post-diagnosis were recruited between November 2009 and April 2011 from four hospitals across Canada. Line-by-line coding was used to establish codes and themes and constant comparison was used to establish relationships among emerging codes and conceptual themes. RESULTS: The first set of findings report on caregiving duties including: emotional tasks, informational tasks and physical tasks. The second set of findings report on the contextual picture of parent's lives including their living conditions, their physical and mental health and their family histories of disruption, trauma and disease. CONCLUSIONS: Single parents caring for children with cancer were found to experience several cumulative stressors in addition to the current strain of caring for a child with cancer. The synergy of these cumulative stresses with the added strain of caregiving for a child with cancer may have long-term health and financial implications for parents. Broad-based policy interventions should focus on relieving the chronic strains associated with being a single parent of a child with cancer.

Invasive fungal infections in paediatric acute myeloid leukaemia.

Invasive fungal infections (IFIs) are a major cause of morbidity and mortality in paediatric acute myeloid leukaemia (AML). This study describes risk factors for IFI and IFI-related sepsis in this population. We conducted a population-based, retrospective cohort study of children with AML in Canada. IFIs during chemotherapy and prior to haematopoietic stem cell transplantation, relapse, persistent disease or death were identified. Risk factors for proven or probable IFI were examined. Among courses complicated by IFI, risk factors for sepsis were also evaluated. There were 341 children with AML included of which 41 (12.0%) experienced 46 different episodes of IFI. Candida species accounted for 23 (50.0%) of IFIs and Aspergillus spp. accounted for 14 (30.4%). Days of broad-spectrum antibiotics, days of corticosteroids and neutropenia at start of the course were independently associated with IFI. Only days of fever were independently associated with IFI-related sepsis. Invasive fungal infections occurred in 12.0% of paediatric AML patients. Risk factors for IFI and IFI-related sepsis were identified. This knowledge may help to consider targeted strategies.

Family-centred care: a qualitative study of Chinese and South Asian immigrant parents' experiences of care in paediatric oncology.

BACKGROUND: Over the past two decades, there is increasing emphasis being placed upon providing family-centred care (FCC) in paediatric oncology settings. However, there is a lack of knowledge of FCC in paediatric oncology from the perspectives of immigrant parents. The purpose of this paper is to describe Chinese and South Asian immigrant parents' experiences of FCC in paediatric oncology settings in Canada. METHODS: This study adopted a constructivist grounded theory approach. Fifty first generation Chinese and South Asian parents of children with cancer who were at least 6 months post-diagnosis were recruited from six Canadian paediatric oncology centres. Interviews were conducted in English, Cantonese, Mandarin, Urdu, Punjabi or Hindi, and transcribed into English. Analysis involved line-by-line, focused and theoretical coding, and the use of the constant comparison method. RESULTS: Findings indicated that overall parents were highly satisfied with the care and services they received, and their experiences were reflective of the key elements of FCC. However, there were some areas of concern identified by participants: parents not perceiving themselves as a member of the medical team; inconsistency in the quality and co-ordination of services among healthcare providers; disrespectful and mechanical manner of a few healthcare providers; and parents' discomfort with healthcare providers communicating sensitive health-related information directly with their child. CONCLUSIONS: In order to successfully provide family-centred services to immigrant parents of children with cancer, better communication of the elements of FCC between healthcare staff and families is needed to negotiate a clear role for the parents as partners of the healthcare team. Moreover, a better understanding of how family relationships are structured in immigrant families will assist healthcare providers to balance the best interests of the child with that of the family as a unit.

The use of parenteral nutrition for the management of PKU patient undergoing chemotherapy for lymphoma: a case report.

The metabolic control of phenylalanine levels is a challenge during illness. We present the metabolic management of a 6 year old boy with classical PKU who was diagnosed with stage III intraabdominal Burkit's lymphoma and underwent surgical resection and chemotherapy. The metabolic control during chemotherapy was achieved by the use of parenteral custom made amino acid solution and pro-active adjustment of intake. From the 94 obtained plasma phenylalanine (Phe) levels, 18.4% were above our clinic's recommended upper limit (360 µmol/L, 6 mg/dL) while 52.7% of Phe levels were below the recommended lower limit (120 µmol/L, 2 mg/dL). Phe levels above recommended range were associated with low caloric/protein intake, while levels below recommended range reflected the difficulty in achieving the full prescribed Phe intake. We recommend early institution of custom made amino acid solution with maximum amino acid content and caloric intake to provide optimal phenylalanine control. Administration of phenylalanine via regular intravenous amino acid solution may assist in avoiding low Phe levels when prescribed intake is compromised due to vomiting and other disease related illnesses. Use of custom made, phenylalanine free amino acid solution proved beneficial in the management of blood phenylalanine levels in a PKU patient during chemotherapy for Burkitt lymphoma.

Identifying developmental toxicity pathways for a subset of ToxCast chemicals using human embryonic stem cells and metabolomics.

Metabolomics analysis was performed on the supernatant of human embryonic stem (hES) cell cultures exposed to a blinded subset of 11 chemicals selected from the chemical library of EPA's ToxCast™ chemical screening and prioritization research project. Metabolites from hES cultures were evaluated for known and novel signatures that may be indicative of developmental toxicity. Significant fold changes in endogenous metabolites were detected for 83 putatively annotated mass features in response to the subset of ToxCast chemicals. The annotations were mapped to specific human metabolic pathways. This revealed strong effects on pathways for nicotinate and nicotinamide metabolism, pantothenate and CoA biosynthesis, glutathione metabolism, and arginine and proline metabolism pathways. Predictivity for adverse outcomes in mammalian prenatal developmental toxicity studies used ToxRefDB and other sources of information, including Stemina Biomarker Discovery's predictive DevTox® model trained on 23 pharmaceutical agents of known developmental toxicity and differing potency. The model initially predicted developmental toxicity from the blinded ToxCast compounds in concordance with animal data with 73% accuracy. Retraining the model with data from the unblinded test compounds at one concentration level increased the predictive accuracy for the remaining concentrations to 83%. These preliminary results on a 11-chemical subset of the ToxCast chemical library indicate that metabolomics analysis of the hES secretome provides information valuable for predictive modeling and mechanistic understanding of mammalian developmental toxicity.

Identification of paediatric cancer patients with poor quality of life.

The primary objective was to describe predictors of physical, emotional and social quality of life (QoL) in children receiving active treatment for cancer. This Canadian multi-institutional cross-sectional study included children with cancer receiving any type of active treatment. The primary caregiver provided information on child physical, emotional and social QoL according to the PedsQL 4.0 Generic Core scales. Between November 2004 and February 2007, 376 families provided the data. In multiple regression, children with acute lymphoblastic leukemia had better physical health (OR: 0.37, 95% CI 0.23, 0.60; P<0.0001) while intensive chemotherapy treatment (OR: 2.34, 95% CI: 1.42, 3.85; P=0.0008) and having a sibling with a chronic condition (OR: 2.53, 95% CI: 1.54, 4.15; P=0.0002) were associated with poor physical QoL. Better emotional health was associated with good prognosis, less intensive chemotherapy treatment and greater household savings, whereas female children and those with a sibling with a chronic condition had poor social QoL. Physical, emotional and social QoL are influenced by demographic, diagnostic and treatment variables. Sibling and household characteristics are associated with QoL. This information will help to identify children at higher risk of poor QoL during treatment for cancer.

Myosin mRNA accumulation and myofibrillogenesis at the myotendinous junction of stretched muscle fibers.

Myofiber growth and myofibril assembly at the myotendinous junction (MTJ) of stretch-hypertrophied rabbit skeletal muscle was studied by in situ hybridization, immunofluorescence, and electron microscopy. In situ hybridization identified higher levels of myosin heavy chain (MHC) mRNA at the MTJ of fibers stretched for 4 d. Electron microscopy at the MTJ of these lengthening fibers revealed a large cytoplasmic space devoid of myofibrils, but containing polysomes, sarcoplasmic reticulum and T-membranes, mitochondria, Golgi complexes, and nascent filament assemblies. Tallies from electron micrographs indicate that myofibril assembly in stretched fibers followed a set sequence of events. (a) In stretched fiber ends almost the entire sarcolemmal membrane was electron dense but only a portion had attached myofibrils. Vinculin, detected by immunofluorescence, was greatly increased at the MTJ membrane of stretched muscles. (b) Thin filaments were anchored to the sarcolemma at the electron dense sites. (c) Thick filaments associated with these thin filaments in an unregistered manner. (d) Z-bodies splice into thin filaments and subsequently thin and thick filaments fall into sarcomeric register. Thus, the MTJ is a site of mRNA accumulation which sets up regional protein synthesis and myofibril assembly. Stretched muscles also lengthen by the addition of myotubes at their ends. After 6 d of stretch these myotubes make up the majority of fibers at the muscle ends. Essentially all these myotubes repeat the developmental program of primary myotubes and express slow MHC. MHC mRNA distribution in myotubes is disorganized as is the distribution of their myofibrils.

Evaluating family-centred service in paediatric oncology with the measure of processes of care (MPOC-20).

BACKGROUND: In order to evaluate the family-centeredness of paediatric oncology services, a psychometrically sound measure of family-centred services is needed. We performed a comprehensive evaluation of the psychometric properties of the 20-item Measure of Processes of Care (MPOC-20) in parents of children undergoing treatment for cancer at five paediatric oncology centres in Canada. METHODS: The sample included 411 parents (80% response rate). Exploratory factor analysis was used to determine the best way to group the items into scales. Psychometric tests were used to examine data quality, targeting, internal consistency reliability, within-scale construct validity and known-groups validity. RESULTS: Exploratory factor analysis identified two factors: a summary measure of family-centred services and a scale measuring activities that meet parents' general informational needs. Scores spanned the entire scale range, floor and ceiling effects were low, and the sample distribution was not unduly skewed. Scales showed acceptable internal consistency reliability (Cronbach's alphas > or =0.93). Known-group hypotheses supported the scales' ability to differentiate between groups hypothesized to differ. Moderate effect sizes were found when MPOC-20 scale scores for parents and for children with good quality of life were compared with those with poor quality of life. CONCLUSIONS: The MPOC-20 is the only evaluated instrument currently available to measure family-centred services in paediatric oncology. Paediatric cancer programmes can now use this tool to determine parental perception of the extent to which services are family-centred.

Single nucleotide polymorphism in IL1B is associated with infection risk in paediatric acute myeloid leukaemia.

We evaluated single nucleotide polymorphisms (SNPs) associated with infection risk in children with newly diagnosed acute myeloid leukaemia (AML). We conducted a multicentre, prospective cohort study that included children aged ≤18 years with de novo AML. DNA was isolated from blood lymphocytes or buccal swabs, and candidate gene SNP analysis was conducted. Primary outcome was the occurrence of microbiologically documented sterile site infection during chemotherapy. Secondary outcomes were Gram-positive and -negative infections, viridans group streptococcal infection and proven/probable invasive fungal infection. Interpretation was guided by consistency in risk alleles and microbiologic agent with previous literature. Over the study period 254 children and adolescents with AML were enrolled. Overall, 190 (74.8%) had at least one sterile site microbiologically documented infection. Among the 172 with inferred European ancestry and DNA available, nine significant associations were observed; two were consistent with previous literature. Allele A at IL1B (rs16944) was associated with decreased microbiologically documented infection, and allele G at IL10 (rs1800896) was associated with increased risk of Gram-positive infection. We identified SNPs associated with infection risk in paediatric AML. Genotype may provide insight into mechanisms of infection risk that could be used for supportive-care novel treatments.

The influence of the base-paired flanking region on structure and function of the ferritin mRNA iron regulatory element.

Ferritin and transferrin receptors are co-ordinately regulated by the same RNA-protein interaction: the conserved iron regulatory element (IRE) in mRNA and the IRE-binding protein (IRE-BP/IRP/FRP/P-90). The 28 nucleotide IRE in ferritin mRNA is a single copy, with base-paired flanking regions (FL), located near the 5' cap. In the transferrin receptor mRNA, the IRE is located in the 3' untranslated region, as five variable copies and lacking predicted base-paired flanking regions; an alternate predicted structure without IREs has similar stability. When iron is scarce, ferritin mRNA does not form polyribosomes whereas the transferrin receptor mRNA is translated; when iron is abundant, ferritin mRNA forms polyribosomes and the transferrin receptor mRNA is degraded. To investigate structures which contribute to differences in the regulation of the two mRNAs, the effect of mutation of the ferritin FL was studied. Changes in structure (changes in reactivity with RNase V1 and RNase S1. Fe-bleomycin) and changes in function (translation in rabbit reticulocyte extracts) were compared for mutant and wild-type FL sequences in ferritin mRNA. The disruption of a triplet of base-pairs in the FL had diminished regulation; a second mutation to restore the triplet base-pairs conferred wild-type translational regulation. Conformation of the mutant RNA-IRE-BP complex was also different. We show that the triplet of base-pairs is conserved; the triplet is also the location of IRE-BP-dependent conformational changes in the FL structure previously observed. Increasing FL base-pairs had no effect on function. Structural changes associated with altered function included bleomycin sites in the IRE, suggesting an alternate conformation of the hairpin, and different base-stacking (V1 sensitivity) in the FL. The function of the FL, which is altered by mutation of phylogenetically conserved triplet base-pairs, may be enhancement of formation of a particular IRE stem-loop-protein interaction.

Natural history of arterial and venous thrombosis in children treated with low molecular weight heparin: a longitudinal study by ultrasound.

Low molecular weight heparin (LMWH) is efficacious in preventing recurrent thromboembolic events (TEs) in children. The efficacy of LMWH in resolving thrombus in children is, however, unknown and may differ from what has been observed in adults due to known differences in the hemostatic system. We reviewed the ultrasound (US) scanning reports of children treated with LMWH in order to determine the rate and predictors of thrombus resolution. Of 245 children consecutively treated for a non-cerebral TE with enoxaparin (Lovenox, Aventis Pharma Inc., QC, Canada) for at least 5 consecutive days, 190 (78%) had serial ultrasound available for analysis. The mean follow-up time was 7 months (median 3 months, range 3 days to 6.6 years). The rate of complete thrombus resolution was 101/190 (53%, 95% confidence interval 46.2-60.2%). On univariate analysis, arterial and non-occlusive thrombus had an increased rate of resolution when compared with venous and occlusive thrombus. Age at time of TE (neonates vs. non-neonates), location of TE, initial treatment (unfractionated heparin vs. LMWH) and dose of enoxaparin were not related to outcome. On multivariate analysis, type of vessel (vein vs. artery) and occlusion (occlusive vs. non-occlusive thrombus) independently predicted outcome. In children, the rate of complete thrombus resolution is similar to the rate in adults. The clinical significance of residual abnormal vessels, specifically to the occurrence of post-thrombotic syndrome and for the diagnosis of recurrence, needs to be explored in prospective studies.

Hydrolytic stability versus ring size in lactams: implications for the development of lactam antibiotics and other serine protease inhibitors.

beta-Lactam antibiotics act by acylating a serine hydroxyl group in the catalytic center of bacterial proteases. This requires, among other things, suitable reactivity of the lactam moiety. To evaluate the possible suitability of other lactam systems, kinetic studies were performed using the model reaction of lactams with hydroxide. Following the pace of the reaction by NMR, we found gamma-butyrolactam to be hydrolyzed considerably slower than beta-propiolactam. Surprisingly, delta-valerolactam and beta-propiolactam had the same reactivity. beta-Lactam antibiotics were more reactive than both by approximately a factor of 10(3). Medium-sized lactams were least susceptible to hydrolysis. The study highlights the as yet overlooked six-membered lactam ring as a promising vantage point for the development of new classes of antiinfectives and other serine protease inhibitors.

Recovering filter-based microarray data for pathways analysis using a multipoint alignment strategy.

The use of commercial microarrays is rapidly becoming the method of choice for profiling gene expression and assessing various disease states. Research Genetics has provided a series of biological and software tools to the research community for these analyses. The fidelity of data analysis using these tools is dependent on a series of well-defined reference control points in the array. During the course of our investigations, it became apparent that in some instances the reference control points that are required for analysis became lost in background noise. This effectively halted the analysis and the recovery of any information contained within that experiment. To recover this data and to increase analytical veracity, the simple strategy of superimposing a template of reference control points onto the experimental array was developed. The utility of this tool is established in this communication.

In situ hybridization and immunocytochemistry in serial sections of rabbit skeletal muscle to detect myosin expression.

We performed in situ hybridization of myosin heavy-chain (MHC) mRNA on rabbit muscle using a biotin-labeled complementary RNA probe. An 1107-nucleotide fragment from an alpha-cardiac MHC cDNA was used to transcribe an RNA probe 97% similar to slow-twitch and 75% similar to fast-twitch sequences. Serial sections were used to identify slow-twitch fibers in medial gastrocnemius, soleus, and tibialis anterior by immunofluorescence of slow MHC and oxidative capacity by histochemistry. Slow-twitch fibers hybridized by the RNA probe stained heavily after detection with streptavidin-alkaline phosphatase (89% dark and 11% medium density). Fast-oxidative fibers stained intermediately (26% dark, 58% medium, and 16% light) and fast-glycolytic fibers stained lightly (12% medium and 88% light). Biotin-labeled probe and enzymatic detection allowed greater resolution of the subcellular location of the MHC mRNA, a distinct advantage over isotope labeling and autoradiography. A non-uniform distribution of MHC mRNA was recognized within an adult skeletal muscle fiber. High concentrations of MHC mRNA were found under the sarcolemma and between the myofibrils, suggesting the existence of a distribution mechanism. The combination of in situ hybridization and immunocytochemistry allows rapid subcellular localization of both MHC mRNA and its translated protein.

Application of DNA arrays to toxicology.

DNA array technology makes it possible to rapidly genotype individuals or quantify the expression of thousands of genes on a single filter or glass slide, and holds enormous potential in toxicologic applications. This potential led to a U.S. Environmental Protection Agency-sponsored workshop titled "Application of Microarrays to Toxicology" on 7-8 January 1999 in Research Triangle Park, North Carolina. In addition to providing state-of-the-art information on the application of DNA or gene microarrays, the workshop catalyzed the formation of several collaborations, committees, and user's groups throughout the Research Triangle Park area and beyond. Potential application of microarrays to toxicologic research and risk assessment include genome-wide expression analyses to identify gene-expression networks and toxicant-specific signatures that can be used to define mode of action, for exposure assessment, and for environmental monitoring. Arrays may also prove useful for monitoring genetic variability and its relationship to toxicant susceptibility in human populations.

Hsp70 expression and function during gametogenesis.

The dramatic transformations in nuclear content and cellular organization that occur during gametogenesis require unique regulation and execution of the mitotic and meiotic cell cycle, apoptotic cell death, DNA recombination and repair, and cellular differentiation. These processes are accompanied by the constitutive and developmentally regulated expression of a number of hsp70 genes encoding 70 kDa heat shock proteins (Hsp70), including several hsp70s whose expression is unique to male germ cells. Examining the expression and function of Hsp70s in germ cells has provided significant insights into mechanisms of hsp70 gene regulation and Hsp70 protein function, as well as the developmental processes of gametogenesis.

Hsp70 expression and function during embryogenesis.

This review focuses on the expression and function of 70-kDa heat shock proteins (Hsp70s) during mammalian embryogenesis, though many features of embryogenesis and the developmental expression of Hsp70s are conserved between mammals and other vertebrates. A variety of Hsp70s are expressed from the point of zygotic gene activation in cleavage-stage embryos, through blastulation, implantation, gastrulation, neurulation, organogenesis, and on throughout fetal maturation. The regulation and patterns of hsp70 gene expression and the known and putative Hsp70 protein functions vary from constitutive and metabolic housekeeping to stress-inducible and embryo-protective roles. Understanding the genetic regulation and molecular function of Hsp70s has been pursued by developmental biologists interested in the control of gene expression in early embryos as well as reproductive toxicologists and teratologists interested in how Hsp70s protect embryos from the adverse effects of environmental exposures. These efforts have also been joined by those interested in the chaperone functions of Hsp70s, and this confluence of effort has yielded many advances in our understanding of Hsp70s during critical phases of embryonic development and cellular differentiation.

Heat shock factor 1-mediated thermotolerance prevents cell death and results in G2/M cell cycle arrest.

Mammalian cells respond to environmental stress by activating heat shock transcription factors (eg, Hsf1) that regulate increased synthesis of heat shock proteins (Hsps). Hsps prevent the disruption of normal cellular mitosis, meiosis, or differentiation by environmental stressors. To further characterize this stress response, transformed wild-type Hsf1+/+ and mutant Hsf1-/- mouse embryonic fibroblasts (MEFs) were exposed to (1) lethal heat (45 degrees C, 60 minutes), (2) conditioning heat (43 degrees C, 30 minutes), or (3) conditioning followed by lethal heat. Western blot analysis demonstrated that only Hsf1+/+ MEFs expressed inducible Hsp70s and Hsp25 following conditioning or conditioning and lethal heat. Exposure of either Hsf1+/+ or Hsf1-/- MEFs to lethal heat resulted in cell death. However, if conditioning heat was applied 6 hours before lethal heat, more than 85% of Hsf1+/+ MEFs survived, and cells in G2/M transiently increased 3-fold. In contrast, conditioned Hsf1-/- MEFs neither survived lethal heat nor exhibited this G2/M accumulation. Coinfection with adenoviral Hsp70 and Hsp25 constructs did not fully recreate thermotolerance in either Hsf1+/+ or Hsf1-/- MEFs, indicating other Hsf1-mediated gene expression is required for complete thermotolerance. These results demonstrate the necessity of Hsf1-mediated gene expression for thermotolerance and the involvement of cell cycle regulation, particularly the G2/M transition, in this thermotolerant response.