Survival outcomes for women with a solitary extracranial metastasis from breast cancer

BACKGROUND

Aggressive metastasis directed treatment of extracranial oligometastatic breast cancer with the aim of increasing disease-free survival has emerged as a new potential treatment paradigm, however there is currently a lack of data to assist in identifying the subset of patients who will potentially benefit most. This single-institute retrospective cohort study aimed to evaluate survival outcomes for patients with a solitary extracranial metastasis from breast cancer and to assess for significant prognostic factors.

METHODS AND MATERIALS

Medical records of 70 female breast cancer patients with a solitary extracranial metastasis actively managed at the Peter MacCallum Cancer Centre (PMCC) Melbourne Campus between 2000 and 2019 were reviewed. Kaplan-Meier curves were used to estimate overall survival (OS), local progression free survival (LPFS) and distant progression free survival (DPFS).

RESULTS

Median follow-up period was 9.4 years. The study included 40 hormone receptor positive/HER2 negative (HR+HER2-), 14 hormone receptor positive/HER2 positive (HR+HER2+), 3 hormone receptor negative/HER2 positive (HR-HER2+), 9 triple negative (TNBC) and 4 unclassified breast cancer patients. 5-year OS rate for all patients was 46%, LPFS rate was 56% and DPFS was 20%. Tumour receptor group had a statistically significant association with OS and DPFS rates. TNBC patients had significantly poorer OS and DPFS rates in comparison to HR+HER2-patients.

CONCLUSION

Among patients with a solitary extracranial metastasis from breast cancer, TNBC was associated with the poorest OS and DPFS rates. Identification of other significant prognostic factors for oligometastatic breast cancer patients may inform guidelines for metastasis directed treatments.

The HI-FIVE Trial: A Prospective Trial Using 4-Dimensional 68Ga Ventilation-Perfusion Positron Emission Tomography-Computed Tomography for Functional Lung Avoidance in Locally Advanced Non-small Cell Lung Cancer

PURPOSE

Functional lung avoidance (FLA) radiation therapy aims to spare regions of functional lung to reduce toxicity. We report the results of the first prospective trial of FLA using 4-dimensional gallium 68 ventilation-perfusion positron emission tomography-computed tomography (68Ga-4D-V/Q PET/CT).

METHODS AND MATERIALS

Inclusion criteria required a diagnosis of stage III non-small cell lung cancer and the ability to undergo radical-intent chemoradiation therapy. Functional volumes were generated using planning 68Ga-4D-V/Q PET/CT. These volumes were used to generate a clinical FLA plan to 60 Gy in 30 fractions. The primary tumor was boosted to 69 Gy. A comparison anatomic plan was generated for each patient. Feasibility was met if FLA plans (compared with anatomic plans) allowed (1) a reduction in functional mean lung dose of ≥2% and a reduction in the functional lung volume receiving 20 Gy (fV20Gy) of ≥4%, and (2) a mean heart dose ≤30 Gy and relative heart volume receiving 50 Gy of <25%.

RESULTS

In total, 19 patients were recruited; 1 withdrew consent. Eighteen patients underwent chemoradiation with FLA. Of the 18 patients, 15 met criteria for feasibility. All patients completed the entire course of chemoradiation therapy. Using FLA resulted in an average reduction of the functional mean lung dose of 12.4% (SD, ±12.8%) and a mean relative reduction of the fV20Gy of 22.9% (SD, ±11.9%). At 12 months, Kaplan-Meier estimates for overall survival were 83% (95% CI, 56%-94%) and estimates for progression-free survival were 50% (95% CI, 26%-70%). Quality-of-life scores were stable across all time points.

CONCLUSIONS

Using 68Ga-4D-V/Q PET/CT to image and avoid functional lung is feasible.

The structural components of the Azotobacter vinelandii iron-only nitrogenase, AnfDKG, form a protein complex within the plant mitochondrial matrix

A long-held goal of synthetic biology has been the transfer of a bacterial nitrogen-fixation pathway into plants to reduce the use of chemical fertiliser on crops such as rice, wheat and maize. There are three classes of bacterial nitrogenase, named after their metal requirements, containing either a MoFe-, VFe- or FeFe-cofactor, that converts N₂ gas to ammonia. Relative to the Mo-nitrogenase the Fe-nitrogenase is not as efficient for catalysis but has less complex genetic and metallocluster requirements, features that may be preferable for engineering into crops. Here we report the successful targeting of bacterial Fe-nitrogenase proteins, AnfD, AnfK, AnfG and AnfH, to plant mitochondria. When expressed as a single protein AnfD was mostly insoluble in plant mitochondria, but coexpression of AnfD with AnfK improved its solubility. Using affinity-based purification of mitochondrially expressed AnfK or AnfG we were able to demonstrate a strong interaction of AnfD with AnfK and a weaker interaction of AnfG with AnfDK. This work establishes that the structural components of the Fe-nitrogenase can be engineered into plant mitochondria and form a complex, which will be a requirement for function. This report outlines the first use of Fe-nitrogenase proteins within a plant as a preliminary step towards engineering an alternative nitrogenase into crops.

Increasing use of post-mastectomy hypofractionated radiation therapy for breast cancer in Victoria

INTRODUCTION

The aim of this study was to evaluate the use of post-mastectomy hypofractionationed radiation therapy (HFRT) for breast cancer in Victoria, Australia.

METHODS

This is a population-based cohort of women with breast cancer who received post-mastectomy RT to the chest wall with or without nodal irradiation between 2012 and 2017. HFRT was defined as <25 fractions of RT. Data were captured in the Victorian Radiotherapy Minimum Dataset (VRMDS). The changing pattern of HFRT use was evaluated using the Cochran-Armitage test. Patient-, treatment- and institutional-related factors associated with HFRT use were evaluated using multivariable logistic regression.

RESULTS

Two thousand and twenty-one women were included in this study, of which 238 (12%) received HFRT. This increased from 8% in 2012 to 18% in 2017 (P-trend < 0.001). Older women were more likely to have HFRT (26% in women above 70 years vs 6% in women under 50 years; P < 0.001). Women who did not have nodal irradiation were more likely to have HFRT than those who did (18% vs 9% respectively; P < 0.001). In multivariate analyses, the progressive increase in HFRT use over time remained statistically significant - women treated in 2017 were four times more likely to receive HFRT than those treated in 2012 (95% CI = 2.1-7.7; P < 0.001). Other factors independently associated with increased likelihood of HFRT use included increasing age at RT, and lack of nodal irradiation.

CONCLUSION

In this first Australian study evaluating the use of post-mastectomy HFRT, we observed increasing HFRT use in Victoria over time. We anticipate this rising trend will continue in the coming years.

Single-arm prospective interventional study assessing feasibility of using gallium-68 ventilation and perfusion PET/CT to avoid functional lung in patients with stage III non-small cell lung cancer

BACKGROUND

In the curative-intent treatment of locally advanced lung cancer, significant morbidity and mortality can result from thoracic radiation therapy. Symptomatic radiation pneumonitis occurs in one in three patients and can lead to radiation-induced fibrosis. Local failure occurs in one in three patients due to the lungs being a dose-limiting organ, conventionally restricting tumour doses to around 60 Gy. Functional lung imaging using positron emission tomography (PET)/CT provides a geographic map of regional lung function and preclinical studies suggest this enables personalised lung radiotherapy. This map of lung function can be integrated into Volumetric Modulated Arc Therapy (VMAT) radiotherapy planning systems, enabling conformal avoidance of highly functioning regions of lung, thereby facilitating increased doses to tumour while reducing normal tissue doses.

METHODS AND ANALYSIS

This prospective interventional study will investigate the use of ventilation and perfusion PET/CT to identify highly functioning lung volumes and avoidance of these using VMAT planning. This single-arm trial will be conducted across two large public teaching hospitals in Australia. Twenty patients with stage III non-small cell lung cancer will be recruited. All patients enrolled will receive dose-escalated (69 Gy) functional avoidance radiation therapy. The primary endpoint is feasibility with this achieved if ≥15 out of 20 patients meet pre-defined feasibility criteria. Patients will be followed for 12 months post-treatment with serial imaging, biomarkers, toxicity assessment and quality of life assessment.

DISCUSSION

Using advanced techniques such as VMAT functionally adapted radiation therapy may enable safe moderate dose escalation with an aim of improving local control and concurrently decreasing treatment related toxicity. If this technique is proven feasible, it will inform the design of a prospective randomised trial to assess the clinical benefits of functional lung avoidance radiation therapy.

ETHICS AND DISSEMINATION

This study was approved by the Peter MacCallum Human Research Ethics Committee. All participants will provide written informed consent. Results will be disseminated via publications.

TRIALS REGISTRATION NUMBER

NCT03569072; Pre-results.

Safety, Efficacy, and Patterns of Failure After Single-Fraction Stereotactic Body Radiation Therapy (SBRT) for Oligometastases

Purpose

Fewer attendances for radiation therapy results in increased efficiency and less foot traffic within a radiation therapy department. We investigated outcomes after single-fraction (SF) stereotactic body radiation therapy (SBRT) in patients with oligometastatic disease.

Methods and Materials

Between February 2010 and June 2019, patients who received SF SBRT to 1 to 5 sites of oligometastatic disease were included in this retrospective study. The primary objective was to describe patterns of first failure after SBRT. Secondary objectives included overall survival (OS), progression-free survival (PFS), high-grade treatment-related toxicity (Common Terminology Criteria for Adverse Events grade ≥3), and freedom from systemic therapy (FFST).

Results

In total, 371 patients with 494 extracranial oligometastases received SF SBRT ranging from 16 Gy to 28 Gy. The most common primary malignancies were prostate (n = 107), lung (n = 63), kidney (n = 52), gastrointestinal (n = 51), and breast cancers (n = 42). The median follow-up was 3.1 years. The 1-, 3-, and 5-year OS was 93%, 69%, and 55%, respectively; PFS was 48%, 19%, and 14%, respectively; and FFST was 70%, 43%, and 35%, respectively. Twelve patients (3%) developed grade 3 to 4 treatment-related toxicity, with no grade 5 toxicity. As the first site of failure, the cumulative incidence of local failure (irrespective of other failures) at 1, 3 and 5 years was 4%, 8%, and 8%, respectively; locoregional relapse at the primary was 10%, 18%, and 18%, respectively; and distant failure was 45%, 66%, and 70%, respectively.

Conclusions

SF SBRT is safe and effective, and a significant proportion of patients remain FFST for several years after therapy. This approach could be considered in resource-constrained or bundled-payment environments. Locoregional failure of the primary site is the second most common pattern of failure, suggesting a role for optimization of primary control during metastasis-directed therapy.

Real-world systemic therapy treatment patterns for squamous cell carcinoma of the head and neck in Canada

Background

In the present study, we examined real-world treatment patterns for squamous cell carcinoma of the head and neck (scchn) in Canada, which are largely unknown.

Methods

Oncologists across Canada provided data for disease history, characteristics, and treatment patterns during May-July 2016 for 6-8 consecutive patients receiving first-line or second-line drug treatment for scchn (including locally advanced and recurrent or metastatic disease).

Results

Information from 16 physicians for 109 patients receiving drug treatment for scchn was provided; 1 patient was excluded from the treatment-pattern analysis. Median age in the cohort was 63 years [interquartile range (iqr): 57-68 years], and 24% were current smokers, with a mean exposure of 26.2 ± 12.7 pack-years. The most common tumour site was the oropharynx (48%). Most patients (84%) received platinum-based regimens as first-line treatment (44% received cisplatin monotherapy). Use of cetuximab-based regimens as first-line treatment was limited (17%). Of 53 patients receiving second-line treatment, 87% received a first-line platinum-based regimen. Median time between first-line treatment with a platinum-based regimen and initiation of second-line treatment was 55 days (iqr: 20-146 days). The most common second-line regimen was cetuximab monotherapy (43%); platinum-based regimens were markedly infrequent (13%).

Conclusions

Our analysis provides real-world insight into scchn clinical practice patterns in Canada, which could inform reimbursement decision-making. High use of platinum-based regimens in first-line drug treatment was generally reflective of treatment guidelines; cetuximab use in the second-line was higher than anticipated. Additional real-world studies are needed to understand the effect of novel therapies such as immuno-oncology agents on clinical practice and outcomes, particularly for recurrent or metastatic scchn.

Subcutaneous rather than intravenous ustekinumab induction is associated with comparable circulating drug levels and early clinical response: a pilot study

BACKGROUND

Ustekinumab (USK) is licenced for intravenous induction and subcutaneous (S/C) maintenance in Crohn's disease.

AIM

To evaluate ustekinumab trough concentrations and clinical response with exclusive subcutaneous ustekinumab induction.

METHODS

Patients with Crohn's disease who initiated treatment with subcutaneous ustekinumab at a single academic centre were included in this pilot study. A dosage of 360 mg ustekinumab was given subcutaneously in divided doses; 180 mg at Week 0, 90 mg at Week 1 and 90 mg at Week 2, with corresponding ustekinumab trough concentrations assessed to Week 8. The primary outcome measures were trough serum ustekinumab levels and clinical remission at Week 8. Secondary outcome measures were trough serum ustekinumab levels at Week 1 & 2 and changes in C-reactive protein, albumin and faecal calprotectin at Week 8.

RESULTS

Nineteen patients were included. Median Week 8 ustekinumab trough concentrations were 6.1 μg/mL (Inter-quartile range 4-9.8 μg/mL). There was a significant improvement in Harvey Bradshaw index from Week 0 (median HBI 5; interquartile range 2-8) to Week 8 (median HBI 1; interquartile range 0-3) (P = 0.002). C-reactive protein levels did not change significantly but faecal calprotectin improved significantly; median faecal calprotectin at Week 0 was 533 μg/g; at Week 8, it was 278 μg/g (P = 0.038).

CONCLUSIONS

Ustekinumab trough concentrations are comparable whether ustekinumab induction treatment was administered subcutaneously or intravenously. A significant improvement in symptoms and faecal calprotectin was noted. These results support the use of subcutaneous induction as an alternative if there are barriers to intravenous induction.

Scombrotoxic Fish Poisoning Secondary to Tuna Ingestion

Scombrotoxic poisoning results from the improper handling and refrigeration of fish containing naturally occurring histidine. Scombroid fish species such as tuna, mackerel and swordfish contain histidine, which is converted to histamine when inadequately chilled. European legislation states that scombroid fish species should be tested for the presence of histamine and mean values should be <100mg/kg1. The authors report an outbreak of scombrotoxic fish poisoning in 12 individuals following ingestion of tuna. Symptoms occurred rapidly and included flushing, headache, palpitations and diarrhoea. Fortunately, symptoms were short lived and self-limiting except in one individual, who required anti-histamine medication. Adequate refrigeration practices are crucial in preventing scombrotoxic food poisoning.

68 Ga-PSMA-PET/CT staging prior to definitive radiation treatment for prostate cancer

AIM

To explore the utility of prostate specific membrane antigen (PSMA)-positron emission tomography (PET)/computed tomography (CT) in addition to conventional imaging prior to definitive external beam radiation treatment (EBRT) for prostate cancer.

METHODS

All men undergoing PSMA-PET/CT prior to definitive EBRT for intermediate and high-risk prostate cancer were included in our ethics approved prospective database. For each patient, clinical and pathological results, in addition to scan results including site of PSMA positive disease and number of lesions, were recorded. Results of conventional imaging (bone scan, CT and multiparametric magnetic resonance imaging [MRI]) were reviewed and included.

RESULTS

One hundred nine men underwent staging PSMA-PET/CT between May 2015 and June 2017; all patients had national comprehensive cancer network (NCCN) intermediate or high-risk prostate cancer and 87% had Gleason score (GS) 4 + 3 or higher. There was positive uptake corresponding to the primary in 108, equivocal in one. All patients with image detected nodal or bony lesions had GS 4 + 3 or more disease. Compared to conventional imaging with bone scan, CT and multiparametric MRI, PSMA-PET/CT upstaged an additional 7 patients (6.4%) from M0 to M1, 16 from N0M0 to N1M0 (14.7%) and downstaged 3 (2.8%) from M1 to M0 disease.

CONCLUSION

PSMA-PET/CT identified the primary in 99% of patients, and altered staging in 21% of men with intermediate or high-risk prostate cancer referred for definitive EBRT compared to CT, bone scan and multiparametric MRI. Following this audit, we recommend the routine use of PSMA-PET/CT prior to EBRT in this patient group.

The effect of dabigatran on the kaolin-activated whole blood thromboelastogram

Dabigatran is a direct thrombin inhibitor, which is increasingly likely to be encountered in patients presenting for surgery. This study examines whether there is a consistent effect of dabigatran on the thromboelastogram (TEG) and whether this correlates with the effects of dabigatran on traditional coagulation parameters. Twenty patients taking dabigatran had blood sampled for kaolin-activated whole blood TEG analysis and routine coagulation testing. There was a statistically significant correlation between thrombin clotting time (TCT) and R-time (R=0.77, P=0.0001) and between activated partial thromboplastin time (APTT) and R-time (R=0.68, P=0.0013), but not between TCT and alpha-angle (R= -0.4232, P=0.071). Despite the moderate to high correlation between the TEG R-time and the TCT and APTT, there appeared to be no consistent effect of dabigatran on the TEG. These findings suggest that use of kaolin-activated whole blood TEG does not add additional benefit to traditional coagulation tests when monitoring the effect of dabigatran.

Axial p-n-junctions in nanowires

The charge distribution and potential profile of p-n-junctions in thin semiconductor nanowires (NWs) were analyzed. The characteristics of screening in one-dimensional systems result in a specific profile with large electric field at the boundary between the n- and p- regions, and long tails with a logarithmic drop in the potential and charge density. As a result of these tails, the junction properties depend sensitively on the geometry of external contacts and its capacity has an anomalously large value and frequency dispersion. In the presence of an external voltage, electrons and holes in the NWs can not be described by constant quasi-Fermi levels, due to small values of the average electric field, mobility, and lifetime of carriers. Thus, instead of the classical Sah-Noice-Shockley theory, the junction current-voltage characteristic was described by an alternative theory suitable for fast generation-recombination and slow diffusion-drift processes. For the non-uniform electric field in the junction, this theory predicts the forward branch of the characteristic to have a non-ideality factor η several times larger than the values 1 < η < 2 from classical theory. Such values of η have been experimentally observed by a number of researchers, as well as in the present work.

Genomic architecture of histone 3 lysine 27 trimethylation during late ovine skeletal muscle development

The ruminant developmental transition from late foetus to lamb is associated with marked changes in skeletal muscle structure and function that reflect programming for new physiological demands following birth. To determine whether epigenetic changes are involved in this transition, we investigated the genomic architecture of the chromatin modification, histone 3 lysine 27 trimethylation (H3K27me3), which typically regulates early life developmental processes; however, its role in later life processes is unclear. Chromatin immunoprecipitation coupled with next‐generation sequencing was used to map H3K27me3 nucleosomes in ovine longissimus lumborum skeletal muscle at 100 days of gestation and 12 weeks post‐partum. In both states, H3K27me3 modification was associated with genes, transcription start sites and CpG islands and with transcriptional silencing. The H3K27me3 peaks consisted of two major categories, promoter specific and regional, with the latter the dominant feature. Genes encoding homeobox transcription factors regulating early life development and genes involved in neural functions, particularly gated ion channels, were strongly modified by H3K27me3. Gene promoters differentially modified by H3K27me3 in the foetus and lamb were enriched for gated ion channels, which may reflect changes in neuromuscular function. However, most modified genes showed no changes, indicating that H3K27me3 does not have a large role in late muscle maturation. Notably, promyogenic transcription factors were strongly modified with H3K27me3 but showed no differences between the late gestation foetus and lamb, likely reflecting their lack of involvement in the myofibre fusion process occurring in this transition. H3K27me3 is a major architectural feature of the epigenetic landscape of ruminant skeletal muscle, and it comments on gene transcription and gene function in the context of late skeletal muscle development.

The extent and nature of need for mealtime support among adults with intellectual disabilities

BACKGROUND

For many adults with an intellectual disability (ID), mealtimes carry significant health risks. While research and allied clinical guidance has focused mainly on dysphagia, adults with a range of physical and behavioural difficulties require mealtime support to ensure safety and adequate nutrition. The extent of need for and nature of such support within the wider ID population has yet to be reported.

METHODS

In this study, we have estimated the prevalence of need for mealtime support among people with ID in the UK, using a population of 2230 adults known to specialist ID services (in Cambridgeshire, UK, total population 586,900). In a sample (n = 69, aged 19 to 79 years, with mild to profound ID), we characterised the support provided, using a structured proforma to consult support workers and carers providing mealtime support, and health and social care records.

RESULTS

Mealtime support was found to be required by a significant minority of people with ID for complex and varied reasons. Prevalence of need for such support was estimated at 15% of adults known to specialist ID services or 56 per 100,000 total population. Within a sample, support required was found to vary widely in nature (from texture modification or environmental adaptation to enteral feeding) and in overall level (from minimal to full support, dependent on functional skills). Needs had increased over time in almost half (n = 34, 49.3%). Reasons for support included difficulties getting food into the body (n = 56, 82.2%), risky eating and drinking behaviours (n = 31, 44.9%) and slow eating or food refusal (n = 30, 43.5%). These proportions translate into crude estimates of the prevalence of these difficulties within the known ID population of 11.9%, 6.6% and 6.4% respectively. Within the sample of those requiring mealtime support, need for support was reported to be contributed to by the presence of additional disability or illness (e.g. visual impairment, poor dentition and dementia; n = 45, 65.2%) and by psychological or behavioural issues (e.g. challenging behaviour, emotional disturbance; n = 36, 52.2%).

CONCLUSIONS

These findings not only highlight the need for a multidisciplinary approach to mealtime interventions (paying particular attention to psychological and environmental as well as physical issues), but also signal the daily difficulties faced by carers and paid support workers providing such support and illustrate their potentially crucial role in managing the serious health risks associated with eating and drinking difficulties in this population.

Genetic structure of European sheep breeds

Large-scale evaluations of genetic diversity in domestic livestock populations are necessary so that region-specific conservation measures can be implemented. We performed the first such survey in European sheep by analysing 820 individuals from 29 geographically and phenotypically diverse breeds and a closely related wild species at 23 microsatellite loci. In contrast to most other domestic species, we found evidence of widespread heterozygote deficit within breeds, even after removing loci with potentially high frequency of null alleles. This is most likely due to subdivision among flocks (Wahlund effect) and use of a small number of rams for breeding. Levels of heterozygosity were slightly higher in southern than in northern breeds, consistent with declining diversity with distance from the Near Eastern centre of domestication. Our results highlight the importance of isolation in terms of both geography and management in augmenting genetic differentiation through genetic drift, with isolated northern European breeds showing the greatest divergence and hence being obvious targets for conservation. Finally, using a Bayesian cluster analysis, we uncovered evidence of admixture between breeds, which has important implications for breed management.

Analysis of gene expression during the onset of muscle hypertrophy in callipyge lambs

The callipyge mutation causes postnatal muscle hypertrophy in heterozygous lambs that inherit a paternal callipyge allele (+/CLPG). Our hypothesis was that the up-regulation of one or both of the affected paternally expressed genes (DLK1 or PEG11) initiates changes in biochemical and physiological pathways in skeletal muscle to induce hypertrophy. The goal of this study was to identify changes in gene expression during the onset of muscle hypertrophy to identify the pathways that are involved in the expression of the callipyge phenotype. Gene expression was analysed in longissimus dorsi total RNA from lambs at 10, 20, and 30 days of age using the Affymetrix Bovine Expression Array. An average of 40.6% of probe sets on the array was detected in sheep muscle. Data were normalized and analysed using a two-way anova for genotype and age effects with a false discovery rate of 0.10. From the anova, 13 genes were significant for the effect of genotype and 13 were significant for effect of age (P < 0.10). No significant age-by-genotype interactions were detected (P > 0.10). Of the 13 genes indicating an effect of genotype, quantitative PCR assays were developed for all of them and tested on a larger group of animals from 10 to 200 days of age. Nine genes had significantly elevated transcript levels in callipyge lambs. These genes included phosphofructokinase, a putative methyltransferase protein, a cAMP phosphodiesterase, and the transcription factor DNTTIP1.

Releases from copper smelters and refineries and zinc plants in Canada: human health exposure and risk characterization

In these assessments of releases from copper smelters and refineries and from zinc plants as Priority Substances under the Canadian Environmental Protection Act (CEPA), available data were critically evaluated to determine if environmental exposure to selected components of these releases poses a risk to human health. The data on airborne levels of a variety of toxic substances near these facilities in Canada were obtained from the companies or provinces and systematically analyzed. Monitoring of ambient air near the Canadian copper smelters and refineries and zinc plants indicates that releases from these facilities result in increased potential for inhalation exposure of local human populations to several components of releases (As, Cd, Cr, Ni, Pb, SO(2) and PM(10)). Airborne levels in the vicinity of these metal-processing operations overlap those associated with cardiorespiratory effects for PM(10), and exceed health-based guidelines for SO(2) and, near some facilities, Pb. In addition, the margin between levels of As, Cd, Cr and Ni near these facilities in Canada and carcinogenic potency for each of these metals is relatively small near copper smelters, larger near copper refineries, and intermediate near zinc plants. On this basis, the risk to human health from environmental exposure to releases from these facilities is considered to be high compared with other Priority Substances assessed under CEPA, especially for facilities where copper is smelted.

Intussusception in an adult patient with severe hyperglycaemia--a case report

AIMS

To report a case of adult intussusception associated with and possibly induced by acute hyperglycaemia.

METHODS

We present the first case report of adult intussusception with severe hyperglycaemia. Clinical and laboratory data together with radiological findings are presented with a brief review of the literature.

RESULTS

A 20-year-old man with no past medical history presented with abdominal pain for 2 days. The patient was severely hyperglycaemic with blood glucose of 72.7 mmol/l (normal 3.3-6.1 mmol/l), a pH of 7.2 and serum potassium of 6.5 mmol/l (normal 3.5-5.0 mmol/l). He had a computed tomography (CT) scan of the abdomen that revealed small bowel intussusception. Upon treatment of his hyperglycaemia, the patient's abdominal pain completely resolved. Follow up abdominal CT revealed complete resolution of the previously detected intussusception.

CONCLUSION

Clinicians should be aware of the potential for the occurrence of intussusception in severely hyperglycaemic patients. Correction of hyperglycaemia could lead to resolution of the intussusception without surgical intervention. Possible effects of hyperkalaemia and/or acidosis on gastrointestinal motility should also be considered.

A novel method using formamide for the elution of antibodies from erythrocytes

BACKGROUND AND OBJECTIVES

Accurate identification of antibodies that sensitize red blood cells (RBCs) involves dissociating them from RBCs using an in vitro elution method that does not alter their antigen-binding properties, and analysis of the eluates against a panel of RBCs.

MATERIALS AND METHODS

A method was developed that allowed efficient RBC antibody elution. Human polyclonal anti-D was used to sensitize Rh-positive RBCs, and known antigen-antibody disruptive reagents were tested using these RBCs. The best reagent conditions were optimized. Eluates made were tested and compared to results obtained with a glycine-acid-based commercial elution kit to determine efficacy. Patient samples that were positive with direct antiglobulin tests (DATs), and in vitro commercial antisera-sensitized RBCs representing clinically significant antibodies, were used for evaluating the new method.

RESULTS

The formamide method was efficient at removing antibodies from RBCs. The patient samples with a positive DAT had antibodies recovered with the same specificity when compared to the acid-based technique. The length of preparation time was similar for both formamide and acid-based methods. Results of testing the eluates made from reagent RBCs sensitized with commercial antisera were distinct with antigen-positive and -negative erythrocytes.

CONCLUSIONS

The formamide method compares well with acid techniques and may be an alternative choice of elution method.

In vitro RBC exposure to Plasmodium falciparum has no effect on RBC antigen expression

Severe malarial anaemia is a leading cause of death in African children younger than 3 years of age who are infected with Plasmodium falciparum. The pathogenesis of this anaemia is not understood. The purpose of this study was to determine if P. falciparum induces changes in RBC membranes that contribute to the immune destruction of RBCs. RBCs were collected from healthy subjects and tested using standard haemagglutination assays for 45 antigens representing 21 blood group systems/collections before and after exposure to P. falciparum, strain FVO. Lectins were used to determine whether crypt or neoantigens were expressed on the RBC membrane. Polybrene was used to detect changes in sialic acid. RBCs were cultured in vitro with and without the parasite, and blinded serologic studies were completed. CD35 (complement receptor 1), CD55 (decay-accelerating factor), CD59 (membrane inhibitor of reactive lysis) and CD47 (integrin-associated protein) flow cytometric assays were compared for infected and uninfected RBCs. The percentage of parasitaemia was determined using Giemsa-stained thin blood films. Two (Ch, Lub) of the 45 antigens had differing strengths of agglutination between infected and uninfected RBCs, but these differences were resolved with a second source of antisera. Forty-three antigens showed no significant differences in the strength of agglutination between the infected and uninfected RBCs. Lectin and polybrene testing showed no differences. CD35, CD55, CD59 and CD47 levels showed no significant differences. P. falciparum does not appear to alter the expression of classified immunogenic antigens on the RBC membrane in this in vitro system. The pathogenesis of the haemolytic episode that occurs in these children remains unclear.

Physical mapping of CSF2RA, ANT3 and STS on the pseudoautosomal region of bovine chromosome X

The pseudoautosomal region (PAR) of bovine chromosome X (BTA X) has a particularly low representation of genes and markers, making comparative gene mapping in this region difficult. We describe the localization of three genes, colony-stimulating factor 2 receptor alpha (CSF2RA), ADP/ATP translocase 3 (ANT3) and steroid sulphatase (STS) on PAR of BTA X using a 5000 rad whole-genome radiation hybrid panel. The relationship of these genes to a number of previously mapped simple sequence repeat (microsatellite) markers is determined by physical and radiation hybrid mapping methods. The resulting radiation hybrid map resolves a discrepancy between the two major bovine linkage maps in the PAR of BTA X.

Radiation response and cure rate of human colon adenocarcinoma spheroids of different size: the significance of hypoxia on tumor control modelling

PURPOSE

To evaluate the adequacy of a Poisson tumor control probability (tcp) model and the impact of hypoxia on tumor cure.

METHODS AND MATERIALS

A human colon adenocarcinoma cell line, WiDr, was grown as multicellular spheroids of different diameters. Measurements were made of cell survival and spheroid cure following 300-kV X-ray external beam irradiation in air and nitrogen. Cell survival data were fitted using a two-compartment and an oxygen diffusion model. Spheroid cure data were fitted using the tcp model.

RESULTS

Hypoxia was seen only for spheroids greater than 500 microm in diameter. For small spheroids tcp estimates of radiosensitivity and clonogenic number showed excellent agreement with experimentally derived values. For large spheroids, although tcp estimates of radiosensitivity were comparable with measurements, estimates of the clonogenic number were considerably lower than the experimental count. Reoxygenation of large spheroids before irradiation resulted in the tcp estimates of the number of clonogenic cells agreeing with measured values.

CONCLUSIONS

When hypoxia was absent, the tcp model accurately predicted cure from measured radiosensitivity and clonogen number. When hypoxia was present, the number of cells capable of regrowth in situ was considerably lower than the number of clonogenic cells that initially survived irradiation. As this counteracted the decreased radiosensitivity, hypoxia was less important for cure than predicted from cell survival assays. This finding suggests that chronic hypoxia may not limit directly the success of radiation therapy.

Satellite cell regulation following myotrauma caused by resistance exercise

It is generally accepted that the primary mechanisms governing skeletal muscle hypertrophy are satellite cell activation, proliferation, and differentiation. Specific growth factors and hormones modulate satellite cell activity during normal muscle growth, but as a consequence of resistance exercise additional regulators may stimulate satellite cells to contribute to gains in myofiber size and number. Present knowledge of the regulation of the cellular, biochemical and molecular events accompanying skeletal muscle hypertrophy after resistance exercise is incomplete. We propose that resistance exercise may induce satellite cells to become responsive to cytokines from the immune system and to circulating hormones and growth factors. The purpose of this paper is to review the role of satellite cells and growth factors in skeletal muscle hypertrophy that follows resistance exercise.

Ten commandments for preventing contamination of primary cell cultures

Procedures for preventing contamination in primary cell cultures must be carefully defined and strictly followed in order to obtain healthy cells. Protocols have been developed and refined in our laboratory for establishing primary cultures of muscle and fat stem cells without contamination from a variety of animals. Contamination of cell cultures is not only frustrating, but is also very expensive both in time and loss of materials. Through the consistent use of proper aseptic techniques, most instances of contamination may be avoided. We suggest that the basic principles detailed here will find wide applicability in the culturing of primary cells without contamination from many different types of animals and tissues.