Pronounced cortisol response to acute psychosocial stress in type 2 diabetes patients with and without complications

It is increasingly recognized that psychological stress is linked with type 2 diabetes mellitus and its late complications. Thus, the aim of the current study was to investigate the psychophysiological response to acute psychosocial stress in patients with type 2 diabetes. In total, 53 type 2 diabetes patients with complications, 16 type 2 diabetes patients without complications, and 47 age and gender matched non-diabetic participants underwent the Trier Social Stress Test. Subjective as well as biological parameters (i.e., blood levels of cortisol, adrenocorticotropic hormone (ACTH), norepinephrine, methylglyoxal) were assessed repeatedly before and after stress induction. Data were analyzed by means of multilevel regression. Patients with type 2 diabetes showed an exaggerated cortisol response to acute stress as compared to age matched control participants (diabetes*T2 est. = 1.23, p < .001), while stress-induced alterations of ACTH and subjective parameters did not differ. Norepinephrine levels were lower among patients (diabetes est. = -4.36, p = .044) and tended to decrease earlier than in controls. The subjective reaction of type 2 diabetes patients with complications was stronger than that of patients without complications (complication*T2 est. = -1.83, p = .032), while their endocrine response to stress was similar. Stress had no effect on methylglyoxal level, and there were no group differences regarding methylglyoxal response. These results show that the cortisol reactivity of patients with type 2 diabetes to acute psychosocial stress is increased compared to a control group. Thus, alterations of the hypothalamus-pituitary-adrenal axis - especially regarding its dynamic regulation - are a plausible link between psychological stress and type 2 diabetes and its complications.

Lung Transplant Recipients with SARS-CoV-2 Infection Induce Circulating Exosomes with SARS-CoV-2 Spike Protein S2 Which Are Immunogenic in Mice

Purpose

Methods

Results

Conclusion

National estimates from the Youth '19 Rangatahi smart survey: A survey calibration approach

BACKGROUND

Significant progress has been made addressing adolescent health needs in New Zealand, but some areas, such as mental health issues remain, particularly for rangatahi Māori (indigenous Māori young people). Little is known about how contemporary Māori whānau (families) and communities influence health outcomes, health literacy and access to services. Previous nationally representative secondary school surveys were conducted in New Zealand in 2001, 2007 and 2012, as part of the Youth2000 survey series. This paper focuses on a fourth survey conducted in 2019 (https://www.youth19.ac.nz/). In 2019, the survey also included kura kaupapa Māori schools (Māori language immersion schools), and questions exploring the role of family connections in health and wellbeing. This paper presents the overall study methodology, and a weighting and calibration framework in order to provide estimates that reflect the national student population, and enable comparisons with the previous surveys to monitor trends.

METHODS

Youth19 was a cross sectional, self-administered health and wellbeing survey of New Zealand high school students. The target population was the adolescent population of New Zealand (school years 9-13). The study population was drawn from three education regions: Auckland, Tai Tokerau (Northland) and Waikato. These are the most ethnically diverse regions in New Zealand. The sampling design was two-stage clustered stratified, where schools were the clusters, and strata were defined by kura schools and educational regions. There were four strata, formed as follows: kura schools (Tai Tokerau, Auckland and Waikato regions combined), mainstream-Auckland, mainstream-Tai Tokerau and mainstream-Waikato. From each stratum, 50% of the schools were randomly sampled and then 30% of students from the selected schools were invited to participate. All students in the kura kaupapa schools were invited to participate. In order to make more precise estimates and adjust for differential non-response, as well as to make nationally relevant estimates and allow comparisons with the previous national surveys, we calibrated the sampling weights to reflect the national secondary school student population.

RESULTS

There were 45 mainstream and 4 kura schools included in the final sample, and 7,374 mainstream and 347 kura students participated in the survey. There were differences between the sampled population and the national secondary school student population, particularly in terms of sex and ethnicity, with a higher proportion of females and Asian students in the study sample than in the national student population. We calculated estimates of the totals and proportions for key variables that describe risk and protective factors or health and wellbeing factors. Rates of risk-taking behaviours were lower in the sampled population than what would be expected nationally, based on the demographic profile of the national student population. For the regional estimates, calibrated weights yield standard errors lower than those obtained with the unadjusted sampling weights. This leads to significantly narrower confidence intervals for all the variables in the analysis. The calibrated estimates of national quantities provide similar results. Additionally, the national estimates for 2019 serve as a tool to compare to previous surveys, where the sampling population was national.

CONCLUSIONS

One of the main goals of this paper is to improve the estimates at the regional level using calibrated weights to adjust for oversampling of some groups, or non-response bias. Additionally, we also recommend the use of calibrated estimators as they provide nationally adjusted estimates, which allow inferences about the whole adolescent population of New Zealand. They also yield confidence intervals that are significantly narrower than those obtained using the original sampling weights.

Testing for hybridisation of the Critically Endangered Iguana delicatissima on Anguilla to inform conservation efforts

The Caribbean Island of Anguilla in the north-eastern Lesser Antilles is home to one of the last populations of the Critically Endangered Lesser Antillean iguana Iguana delicatissima. This population is highly threatened primarily because of hybridisation with non-native Iguana iguana. This study assesses the degree of hybridisation between Anguilla’s Iguana species firstly using morphological characteristics and then genetic analysis to validate the genetic integrity of morphologically identified I. delicatissima. We also examined the genetic diversity of Anguilla’s I. delicatissima population, and that of a population on the nearby island of Îlet Fourchue, St Barthélemy. Forty-five iguanas were captured in Anguilla and 10 in St Barthélemy, and sequences from 3 nuclear and 1 mtDNA genes were obtained for each. Of the 45 iguanas captured in Anguilla, 22 were morphologically identified as I. delicatissima, 12 as I. iguana and the remainder were identified as hybrids. Morphological assignments were all confirmed by genetic analyses except for one I. iguana and one hybrid individual. These two individuals appeared likely to have originated following ancestral hybridisation events several generations ago. A significant paucity of genetic diversity was found within Anguillan and St Barthélemy I. delicatissima populations, with a single haplotype being identified for each of the three nuclear genes and the mtDNA sequence. This study highlights the urgency for immediate action to conserve Anguilla’s remnant I. delicatissima population. Protection from hybridisation will require translocation to I. iguana-free offshore cays, with supplementary individuals being sourced from neighbouring islands to enhance the genetic diversity of the population.

Growth hormone protects against kainate excitotoxicity and induces BDNF and NT3 expression in chicken neuroretinal cells

There is increasing evidence to suggest a beneficial neuroprotective effect of growth hormone (GH) in the nervous system. While our previous studies have largely focused on retinal ganglion cells (RGCs), we have also found conclusive evidence of a pro-survival effect of GH in cells of the inner nuclear layer (INL) as well as a protective effect on the dendritic trees of the inner plexiform layer (IPL) in the retina. The administration of GH in primary neuroretinal cell cultures protected and induced neural outgrowths. Our results, both in vitro (embryo) and in vivo (postnatal), showed neuroprotective actions of GH against kainic acid (KA)-induced excitotoxicity in the chicken neuroretina. Intravitreal injections of GH restored brain derived neurotrophic factor (BDNF) expression in retinas treated with KA. In addition, we demonstrated that GH over-expression and exogenous administration increased BDNF and neurotrophin-3 (NT3) gene expression in embryonic neuroretinal cells. Thus, GH neuroprotective actions in neural tissues may be mediated by a complex cascade of neurotrophins and growth factors which have been classically related to damage prevention and neuroretinal tissue repair.

Methylglyoxal is associated with changes in kidney function among individuals with screen-detected Type 2 diabetes mellitus

AIMS

The glycolysis-derived metabolite methylglyoxal has been linked to clinical microvascular complications, including diabetic nephropathy. We aimed to further investigate the hypothesis that methylglyoxal is involved in decline in renal function by assessing the associations between measures of renal function during a 6-year follow-up in 1481 people with screen-detected Type 2 diabetes, as part of the Danish arm of the ADDITION-Europe trial (ADDITION-DK).

METHODS

Biobank serum samples collected at ADDITION-DK baseline (2001-2006) and follow-up (2009-2010) were used in the current analysis of methylglyoxal. We assessed cross-sectional baseline and longitudinal associations between methylglyoxal and urinary albumin-to-creatinine ratio (ACR) or estimated GFR (eGFR), and between methylglyoxal and categories of albuminuria or reduced eGFR.

RESULTS

Baseline methylglyoxal was positively associated with ACR at baseline (12% higher ACR per doubling in methylglyoxal levels), and change in methylglyoxal during 6 years of follow-up was inversely associated with change in eGFR (-1.6 ml/min/1.73 m² per doubling in methylglyoxal change), in models adjusted for age, sex, HbA_1c , systolic blood pressure, anti-hypertensive treatment, LDL-cholesterol, lipid-lowering treatment, C-reactive protein and smoking.

CONCLUSIONS

In a population of people with screen-detected Type 2 diabetes, we observed associations between methylglyoxal and markers of renal function: 6-year change in methylglyoxal was inversely associated with 6-year change in eGFR. Also, methylglyoxal at baseline was positively associated with ACR at baseline. Our study lends further support to a role for methylglyoxal in the pathogenesis of diabetic nephropathy.

Dicarbonyl Stress Mimics Diabetic Neurovascular Damage in the Retina

The net effect of euglycemic treatment is grossly overestimated in diabetes mellitus and retinopathy, similar to what is observed in diabetic individuals, is found in the absence of chronic hyperglycemia. Explanations of this clinical paradox include the excess generation of reactive intermediates of metabolism. Excess formation or impaired detoxification of reactive intermediates can also result in multiple posttranslational modifications with a wide range of cellular dysfunctions. The multicellular neurovascular unit represents the response element of the retina which is crucial for the development of diabetic retinopathy. Current evidence suggests that increased reactive intermediates in the retina induce (micro-)glial activation, neurodegeneration and vasoregression similar to alterations found in the diabetic retina. Reactive metabolites can be lowered by metabolic signal blockade, by an activation of detoxification pathways and by quenching. The translation of these novel findings into treatment of patients with complications is important to reduce individual suffering and financial burden for societies.Quick Summary:Increased levels of reactive intermediates, independent of blood glucose levels, are linked to damage of the neurovascular unit of the diabetic retina.

Group Singing as a Therapy during Diabetes Training--A Randomized Controlled Pilot Study

Comprehensive diabetes treatment has been shown to reduce quality of life in diabetic patients. However, there is evidence to suggest that group singing can have positive effects on quality of life in various clinical settings. In this randomized controlled pilot study, the effect of singing as a therapy to reduce stress and improve quality of life was investigated in insulin-dependent diabetic patients, undergoing a lifestyle intervention program. Patients from the singing group felt less discontented following treatment. This effect, however, was lost after 3 months. No effect on serum cortisol and plasma adrenocorticotropic hormone (ACTH) levels could be seen when comparing the singing group with the control group, although reduced levels of ACTH and cortisol 3 days after treatment could be found and were still present after 3 months within the group of patients who undertook singing as a therapy. Singing led to an increase in bodyweight, which interestingly had no effect on glucose control or methylglyoxal levels. Therefore, singing during a lifestyle intervention program for insulin-dependent diabetic patients had a short lasting and weak effect on patients' mood without affecting glucose control, but no significant effect on stress related hormones.

The role of serum methylglyoxal on diabetic peripheral and cardiovascular autonomic neuropathy: the ADDITION Denmark study

AIMS

Cardiovascular autonomic neuropathy and diabetic peripheral neuropathy are common diabetic complications and independent predictors of cardiovascular disease. The glucose metabolite methylglyoxal has been suggested to play a causal role in the pathogeneses of diabetic peripheral neuropathy and possibly diabetic cardiovascular autonomic neuropathy. The aim of this study was to investigate the cross-sectional association between serum methylglyoxal and diabetic peripheral neuropathy and cardiovascular autonomic neuropathy in a subset of patients in the ADDITION-Denmark study with short-term screen-detected Type 2 diabetes (duration ~ 5.8 years).

METHODS

The patients were well controlled with regard to HbA(1c), lipids and blood pressure. Cardiovascular autonomic neuropathy was assessed by measures of resting heart rate variability and cardiovascular autonomic reflex tests. Diabetic peripheral neuropathy was assessed by vibration detection threshold (n = 319), 10 g monofilament (n = 543) and the Michigan Neuropathy Screening Instrument questionnaire (n = 966). Painful diabetic neuropathy was assessed using the Brief Pain Inventory short form (n = 882).

RESULTS

No associations between methylglyoxal and cardiovascular autonomic reflex tests or any measures of diabetic peripheral neuropathy or painful diabetic neuropathy were observed. However, a positive association between methylglyoxal and several heart rate variability indices was observed, although these associations were not statistically significant when corrected for multiple testing.

CONCLUSION

Serum methylglyoxal is not associated with cardiovascular autonomic neuropathy, diabetic peripheral neuropathy or painful diabetic neuropathy in this cohort of well-treated patients with short-term diabetes.

Identification and translational validation of novel mammaglobin-A CD8 T cell epitopes

Mammaglobin-A (MAM-A) is a secretory protein that is overexpressed in 80 % of human breast cancers. Its near-universal expression in breast cancer as well as its exquisite tissue specificity makes it an attractive target for a breast cancer prevention vaccine, and we recently initiated a phase 1 clinical trial of a MAM-A DNA vaccine. Previously, we have identified multiple MAM-A CD8 T cell epitopes using a reverse immunology candidate epitope approach based on predicted binding, but to date no attempt has been made to identify epitopes using an unbiased approach. In this study, we used human T cells primed in vitro with autologous dendritic cells expressing MAM-A to systematically identify MAM-A CD8 T cell epitopes. Using this unbiased approach, we identified three novel HLA-A2-restricted MAM-A epitopes. CD8 T cells specific for these epitopes are able to recognize and lyse human breast cancer cells in a MAM-A-specific, HLA-A2-dependent fashion. HLA-A2(+)/MAM-A(+) breast cancer patients have an increased prevalence of CD8 T cells specific for these novel MAM-A epitopes, and vaccination with a MAM-A DNA vaccine significantly increases the number of these CD8 T cells. The identification and translational validation of novel MAM-A epitopes has important implications for the ongoing clinical development of vaccine strategies targeting MAM-A. The novel MAM-A epitopes represent attractive targets for epitope-based vaccination strategies, and can also be used to monitor immune responses. Taken together these studies provide additional support for MAM-A as an important therapeutic target for the prevention and treatment of breast cancer.

A new paradigm to understand and treat diabetic neuropathy

The clinical symptoms of diabetic neuropathy (DN) manifest in a time dependent manner as a positive symptoms (i. e. pain, hypersensitivity, tingling, cramps, cold feet etc.) during its early stages and by a loss of function (i. e. loss of sensory perception, delayed wound healing etc.) predominating in the later stages. Elevated blood glucose alone cannot explain the development and progression of DN and the lowering of blood glucose is insufficient in preventing and/or reversing neuropathy in patients with type 2 diabetes. Recently it has been shown that the endogenous reactive metabolite methylglyoxal (MG) can contribute to the gain of function via post-translational modification in DN of neuronal ion channels involved in chemosensing and action potential generation in nociceptive nerve endings. Dicarbonyls, such as MG, that are elevated in diabetic patients, modify DNA as well as extra- and intracellular proteins, leading to the formation of advanced glycation endproducts (AGEs). Increased formation of AGEs leads to increased cellular stress, dysfunction and ultimately cell death. The interaction of AGE-modified proteins through cell surface receptors, such as RAGE, can lead to increased cellular activation and sustained inflammatory responses, which are the molecular hallmarks of the later, degenerative, stages of DN. The direct and indirect effects of dicarbonyls on nerves or neuronal microvascular network provides a unifying mechanism for the development and progression of DN. Targeting the accumulation of MG and/or prevention of RAGE interactions may therefore provide new, more effective, therapeutic approaches for the treatment of DN.

Abstract OT1-1-02: A phase II randomized trial evaluating the effect of trastuzumab on disease free survival in early stage HER2-negative breast cancer patients with ERBB2-expressing bone marrow disseminated tumor cells

Background: Adjuvant trastuzumab administered concurrently with chemotherapy improves survival in women with Her2-positive breast cancers (BC). A subset of patients with Her2-negative tumors benefit from trastuzumab treatment. We and others have reported discordance in Her2 expression between primary tumors, circulating tumor cells, disseminated tumor cells (DTCs), and metastases. Our data indicate that patients with Her2-negative tumors and Her2-positive DTCs have a greater hazard of recurrence than patients with Her2-negative tumors and Her2-negative DTCs or Her2-positive DTCs treated with trastuzumab. We hypothesize that the subgroup of patients with Her2-negative primary tumors and Her2-positive DTCs will benefit from trastuzumab therapy.

Trial Design: We are conducting a randomized phase II trial in early stage Her2-negative BC patients with Her2-positive DTCs in their bone marrow (BM) at the time of diagnosis who are candidates for chemotherapy. Chemotherapy is doxorubicin/cyclophosphamide q2 weeks for 4 cycles followed by weekly paclitaxel for 12 weeks. Patients randomized to the trastuzumab arm will receive IV trastuzumab concomitant with taxane treatment and then q3 weeks for a total of 52 weeks.

Specific Aims: The primary endpoints are two year recurrence and death rates. Additional endpoints include: elimination of Her2-positive DTCs at completion of therapy, PAM50 analysis of the primary tumor, and association of DTC specific gene expression with outcome.

Eligibility: Patients with newly diagnosed Her2-negative, stage I-III invasive BC who are eligible for chemotherapy and have Her2-positive BM DTCs, as defined by a molecular based assay performed in a CLIA-licensed facility are eligible.

Statistical Methods: Based on our preliminary data, we estimate that 25% of stage II/III Her2-negative breast cancer patients will harbor Her2-positive DTCs in their BM. 200 patients will have their BM screened for Her2-positive DTCs to enroll 50 patients into the trial. Based on the literature and preliminary data, the expected 2-year recurrence rate is 75% in the placebo arm and 40% in the trastuzumab arm. A sample of 46 patients, 23 per arm, will provide power = 0.8 to detect this difference at a 0.05 significance level. The expected proportion of patients who eliminate Her2-positive DTCs from BM is &lt; 10% in the placebo arm and 80% in the trastuzumab arm. The proposed sample will provide power &gt; 0.9 to distinguish Her2-positive DTC elimination rates of 10% vs. 80% and at least 80% power to distinguish a difference of 50% in the elimination rates (e.g. 29% vs. 70%). One interim analysis will be conducted after the first 15 patients have completed 2 years of follow-up and 2 year recurrence rates have been determined. Conditional study power will be used to evaluate the estimates on which study power has been calculated, and the sample size will be adjusted, if necessary. Analysis of the primary endpoints will be at a significance level of 0.0052 for the interim analysis and 0.048 for the final analysis in order to preserve an overall significance level of 0.05.

Accrual: Accrual is anticipated to open August 2013. Target = 25 per arm. NCT01779050.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-1-02.

C332C genotype of glyoxalase 1 and its association with late diabetic complications

AIMS/INTRODUCTION

Glyoxalase 1 catalyses the detoxification of methylglyoxal, a major precursor of advanced glycation end products associated with aging, neurodegenerative diseases, and microvascular complications of diabetes. Here, we examine a possible association of a single nucleotide polymorphism of glyoxalase 1 gene (Glo1 A332C, rs4746 or rs2736654) with the prevalence of microvascular diabetic complications in patients with type 1 and type 2 diabetes.

MATERIALS AND METHODS

Genotyping was performed in 209 patients with type 1 and 524 patients with type 2 diabetes using polymerase chain reaction and subsequent cleavage by restriction endonuclease Bsa I.

RESULTS

Frequencies of the glyoxalase 1 genotypes were different with respect to diabetes type with a significantly higher prevalence of A332A-genotype in type 1 diabetes (35.9% vs. 27.3%; p=0.03). In type 1 diabetes, there was no correlation of any genotype with diabetic retinopathy, nephropathy or neuropathy. In contrast, type 2 diabetic patients homozygous for the C332C allele showed a significantly increased prevalence of diabetic neuropathy (p=0.03; OR=1.49 [95%-CI: 1.04; 2.11]), while no association with diabetic nephropathy or retinopathy was found. However, the significance of this association was lost after correction for multiple testing.

CONCLUSIONS

Our data suggest a possible association of C332C-genotype of the glyoxalase 1 gene with diabetic neuropathy in type 2 diabetes, supporting the hypothesis that methylglyoxal might be an important mediator of diabetic neuropathy in type 2 diabetes.

What is the value of routinely testing full blood count, electrolytes and urea, and pulmonary function tests before elective surgery in patients with no apparent clinical indication and in subgroups of patients with common comorbidities: a systematic review of the clinical and cost-effective literature

BACKGROUND

The evidence base which supported the National Institute for Health and Clinical Excellence (NICE) published Clinical Guideline 3 was limited and 50% was graded as amber. However, the use of tests as part of pre-operative work-up remains a low-cost but high-volume activity within the NHS, with substantial resource implications. The objective of this study was to identify, evaluate and synthesise the published evidence on the clinical effectiveness and cost-effectiveness of the routine use of three tests, full blood counts (FBCs), urea and electrolytes tests (U&Es) and pulmonary function tests, in the pre-operative work-up of otherwise healthy patients undergoing minor or intermediate surgery in the NHS.

OBJECTIVE

The aims of this study were to estimate the clinical effectiveness and cost-effectiveness of routine pre-operative testing of FBC, electrolytes and renal function and pulmonary function in adult patients classified as American Society of Anaesthesiologists (ASA) grades 1 and 2 undergoing elective minor (grade 1) or intermediate (grade 2) surgical procedures; to compare NICE recommendations with current practice; to evaluate the cost-effectiveness of mandating or withdrawing each of these tests in this patient group; and to identify the expected value of information and whether or not it has value to the NHS in commissioning further primary research into the use of these tests in this group of patients.

DATA SOURCES

The following electronic bibliographic databases were searched: (1) BIOSIS; (2) Cumulative Index to Nursing and Allied Health Literature; (3) Cochrane Database of Systematic Reviews; (4) Cochrane Central Register of Controlled Trials; (5) EMBASE; (6) MEDLINE; (7) MEDLINE In-Process & Other Non-Indexed Citations; (8) NHS Database of Abstracts of Reviews of Effects; (9) NBS Health Technology Assessment Database; and (10) Science Citation Index. To identify grey and unpublished literature, the Cochrane Register of Controlled Trials, National Research Register Archive, National Institute for Health Research Clinical Research Network Portfolio database and the Copernic Meta-search Engine were searched. A large routine data set which recorded the results of tests was obtained from Leeds Teaching Hospitals Trust.

REVIEW METHODS

A systematic review of the literature was carried out. The searches were undertaken in March to April 2008 and June 2009. Searches were designed to retrieve studies that evaluated the clinical effectiveness and cost-effectiveness of routine pre-operative testing of FBC, electrolytes and renal function and pulmonary function in the above group of patients. A postal survey of current practice in testing patients in this group pre-operatively was undertaken in 2008. An exemplar cost-effectiveness model was constructed to demonstrate what form this would have taken had there been sufficient data. A large routine data set that recorded the results of tests was obtained from Leeds Teaching Hospitals Trust. This was linked to individual patient data with surgical outcomes, and regression models were estimated.

RESULTS

A comprehensive and systematic search of both the clinical effectiveness and cost-effectiveness literature identified a large number of potentially relevant studies. However, when these studies were subjected to detailed review and quality assessment, it became clear that the literature provides no evidence on the clinical effectiveness and cost-effectiveness of these specific tests in the specific patient groups. The postal survey had a 17% response rate. Results reported that in ASA grade 1, patients aged < 40 years with no comorbidities undergoing minor surgery did not have routine tests for FBC, electrolytes and renal function and pulmonary function. The results from the regression model showed that the frequency of test use was not consistent with the hypothesis of their routine use. FBC tests were performed in only 58% of patients in the data set and U&E testing was carried out in only 57%.

LIMITATIONS

Systematic searches of the clinical effectiveness and cost-effectiveness literature found that there is no evidence on the clinical effectiveness or cost-effectiveness of these tests in this specific clinical context for the NHS. A survey of NHS hospitals found that respondent trusts were implementing current NICE guidance in relation to pre-operative testing generally, and a de novo analysis of routine data on test utilisation and post-operative outcome found that the tests were not be used in routine practice; rather, use was related to an expectation of a more complex clinical case. The paucity of published evidence is a limitation of this study. The studies included relied on non-UK health-care systems data, which may not be transferable. The inclusion of non-randomised studies is associated with an increased risk of bias and confounding. Scoping work to establish the likely mechanism of action by which tests would impact upon outcomes and resource utilisation established that the cause of an abnormal test result is likely to be a pivotal determinant of the cost-effectiveness of a pre-operative test and therefore evaluations would need to consider tests in the context of the underlying risk of specific clinical problems (i.e. risk guided rather than routine use).

CONCLUSIONS

The time of universal utilisation of pre-operative tests for all surgical patients is likely to have passed. The evidence we have identified, though weak, indicates that tests are increasingly utilised in patients in whom there is a reason to consider an underlying raised risk of a clinical abnormality that should be taken into account in their clinical management. It is likely that this strategy has led to substantial resource savings for the NHS, although there is not a published evidence base to establish that this is the case. The total expenditure on pre-operative tests across the NHS remains significant. Evidence on current practice indicates that clinical practice has changed to such a degree that the original research question is no longer relevant to UK practice. Future research on the value of these tests in pre-operative work-up should be couched in terms of the clinical effectiveness and cost-effectiveness in the identification of specific clinical abnormalities in patients with a known underlying risk. We suggest that undertaking a multicentre study making use of linked, routinely collected data sets would identify the extent and nature of pre-operative testing in this group of patients.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Abstract P2-04-02: Identification of genes associated with breast cancer micrometastatic disease in bone marrow using a human-in-mouse xenograft system

Disseminated tumor cells (DTCs) found in the bone marrow (BM) of breast cancer patients portend a poor prognosis and are thought to be the intermediaries in the metastatic process. Study of these cells has been limited due to their scarcity. To develop a clinically relevant model to characterize hese cells, we have employed a human in mouse (HIM) xenograft model for propagating, isolating, and molecularly characterizing DTCs. Human breast adenocarcinomas were prospectively collected from 5 patients and implanted into humanized NOD/SCID mouse mammary fat pads. BM was collected from the long bones at varying passages of the tumors and analyzed for human-specific gene expression by qRT-PCR and gene expression microarray. Human-specific gene expression of SNAI1, GSC, FOXC2, KRT19, and STAM2, presumably originating from disseminated tumor cells, was detectable in the BM of all mice that had developed metastatic disease to other solid organs, but was not detectable in xenotransplanted mice that did not develop metastatic disease. Comparative gene expression microarray analysis of the HIM primary tumor, the corresponding BM from mice with metastatic disease, and BM from control mice identified additional patterns of gene expression enriched in BM-associated DTCs which included several genes associated with epithelial-mesenchymal transition, aggressive clinical phenotype, and metastatic disease development in primary human tumors. We have found that BM DTCs can be detected using the HIM xenograft model and have identified unique patterns of gene expression associated with BM DTCs, which may provide further insight into the biology and therapeutic vulnerability of metastatic tumor cell populations in breast cancer patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-04-02.

Is diabetes an acquired disorder of reactive glucose metabolites and their intermediates?

AIMS/HYPOTHESIS

We hypothesised that diabetic patients would differ from those without diabetes in regard to the handling of glucose-derived reactive metabolites, evidenced by triosephosphate intermediates (TP(INT)) and methylglyoxal (MG), irrespective of the type of diabetes, plasma glucose level or HbA(1c) value.

METHODS

To test this hypothesis, erythrocytes were isolated from patients with type 1 (n = 12) and type 2 (n = 12) diabetes with varying blood glucose and HbA(1c) levels. These were then compared with erythrocytes isolated from individuals without diabetes (n = 10), with respect to MG, as determined by HPLC, and TP(INT), as determined by endpoint enzymatic assays.

RESULTS

The concentrations of intracellular TP(INT) and MG were significantly elevated in erythrocytes from diabetic patients. Normalisation of either TP(INT) or MG to intracellular glucose concentration (nmol glucose/mgHb) confirmed that erythrocytes from diabetic patients accumulated more reactive metabolites than did those from healthy controls.

CONCLUSIONS/INTERPRETATION

Diabetic patients can be characterised by an increased formation of TP(INT) and MG. The 25-fold increase of MG in type 1 and the 15-fold increase in type 2 diabetes, together with a several-fold increase in TP(INT) and decreased glyceraldehyde-3-phosphate dehydrogenase activity even under normal glucose conditions, imply that normalising glucose level cannot completely prevent late diabetic complications until this acquired error of metabolism has been restored.

Outcome of kidney transplantation from elderly donors after cardiac death

BACKGROUND

The rate of renal transplantation is limited by the number of donor organs available. A valuable source of organs is currently supplied by donation after cardiac death (DCD). At the Richard Bright Renal Unit, we have expanded our criteria for DCD, increasing the upper age limit for donation from 65 to 70.

METHOD

We performed a retrospective analysis of all DCD recipients between 2003 and 2009. We compared outcomes for patients age<60 versus >60 as measured by delayed graft function and estimated glomerular filtration rate (eGFR) and incidence of graft failure.

RESULTS

One hundred thirty-six DCD transplantations took place. Our early data showed excellent results for non-heart-beating donation. Over the last 7 years, the average age of DCD donors has increased from 43 in 2003 to 50 in 2009. The increase in age has been correlated with a decrease in average recipient eGFR from 59 in 2003 to 32 in 2009. Recipients of kidneys from older DCD donors (>60) have significantly lower eGFRs at 1 month and 1 year compared to kidneys from donors aged <60. The incidence of delayed graft function in recipients of kidneys from donors aged>60 was 71% compared to 40% for <60 age group. Despite this, we have not found any evidence of higher graft failure rates in the recipients of grafts from the >60 donor age group.

CONCLUSIONS

Expanding the age limits of our DCD donor program has led to an increased average donor age, reduced average eGFR, and increased delayed graft function. There is no evidence of reduced graft survival.

P4-06-03: Multiplex Gene Expression of Disseminated Tumor Cells in the Bone Marrow of Breast Cancer Patients Identifies Novel Therapeutic Targets

Background: Disseminated tumor cells (DTCs) are detected in the bone marrow (BM) of up to 40% of breast cancer patients at the time of diagnosis and are an independent prognostic factor for recurrent disease. Present techniques for detection of DTC are often laborious, and insensitive due to the molecular heterogeneity of the DTCs. We have previously optimized and validated a novel, multiplexed gene expression technology platform, Nanostring nCounter™ (NC) which counts single molecules of RNA, for the multi-marker detection of DTCs in BM at a sensitivity of 1 cancer cell per 1 million nucleated BM cells. We now validate a 36 gene panel for the detection and molecular characterization of DTCs in BM.

Methods: Hybridization probes for 36 genes whose expression are associated with breast cancer, metastasis, and/or the cancer stem cell phenotype, and which exhibit no or low expression levels in normal bone marrow by qRT-PCR were developed for the NC assay. Total RNA was isolated from whole BM collected from the right and left iliac crest from breast cancer patients and healthy volunteers. 5 ug of RNA was analyzed, in duplicate with the NC assay. BM was scored positive for expression of an individual gene if expression in duplicate samples was 2 standard deviations above mean expression in a set of 11 independent normal BM samples.

Results: Bilateral BM samples were analyzed prior to any therapy from 20 patients: 8 developed metastatic disease within 2–48 months (mean of 23 months) after diagnosis, and 12 had no evidence of metastatic disease with 3–5 years follow-up. Overall, expression of at least one gene in the 36-gene multi-marker panel was detected in 17 patients (85%). There was excellent correlation between individual gene expression in both the right and left iliac crest samples from the same patient. Six of the 8 patients (75%) who developed metastatic disease had detectable expression of 1–3 genes. Two genes were commonly associated with metastatic disease development. 50% (3 of 6) of the patients who had detectable expression of EBB2 in their BM developed metastatic disease, although this did not correlate with expression in the corresponding primary tumor from the same patient. 80% (4 of5) of the patients who expressed the hedgehog pathway gene, Ptch1, in their BM developed metastatic disease. Conclusions: Our data demonstrate the feasibility of using a 36-plex NC assay to detect gene expression associated with BM DTCs in breast cancer patients. We found expression of 2 targetable genes associated with the development of metastatic disease, ERBB2 and Ptch1. ERBB2 expression in BM did not correlate with expression in the primary tumor. The molecular diversity of gene expression observed underscores the need for a multiplexed gene expression panel. Ongoing studies are evaluating the clinical utility of this assay to detect DTCs relative to existing techniques, for predicting relapse-free survival, molecular classification, and selecting appropriate targeted therapeutics based on BM DTC profiles in breast cancer patients.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-06-03.