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Dive into the research topics where Chris Pyke is active.

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Featured researches published by Chris Pyke.


Annals of Surgery | 1992

The spectrum of serous cystadenoma of the pancreas. Clinical, pathologic, and surgical aspects.

Chris Pyke; J. A. Van Heerden; T V Colby; M. G. Sarr; Amy L. Weaver

Serous cystadenoma of the pancreas is a rare lesion thought to be almost invariably benign. Since 1978, 211 cases have been reported in the literature. Some have been recognized by computed tomography (CT) when small and asymptomatic. The authors have reviewed their experience with 40 patients (median follow-up of 1.9 years, maximum of 22.2 years) from 1936 to 1991. One third (13) were asymptomatic, of whom eight (20%) were discovered intraoperatively. Of those 20 who had CT, an unequivocal preoperative diagnosis was reached in none. Needle biopsy proved accurate in two patients. Endoscopie retrograde cholangiopancreatography (ERCP) and biopsy were performed with diagnostic success on one occasion. Three patients presented acutely. The tumor was resected in 90%, with an operative mortality rate of 10%. Enucleation of the tumor without formal anatomic pancreatectomy necessitated reoperation for complications in four of eight patients. Survival after successful resection paralleled expected survival. Serous cystadenoma may be associated with von Hippel-Lindau syndrome. The current role for conservative management remains questionable because of our current inability to reliably differentiate many of these benign neoplasms from malignant cystic neoplasms of the pancreas.


British Journal of Cancer | 2007

Numerical and functional defects of blood dendritic cells in early- and late-stage breast cancer.

Alberto Pinzon-Charry; Christopher S. K. Ho; Tammy Maxwell; Michael A. McGuckin; Christopher W. Schmidt; Colin Furnival; Chris Pyke; José Alejandro López

The generation of antitumour immunity depends on the nature of dendritic cell (DC)–tumour interactions. These have been studied mostly by using in vitro-derived DC which may not reflect the natural biology of DC in vivo. In breast cancer, only one report has compared blood DC at different stages and no longitudinal evaluation has been performed. Here we conducted three cross-sectional and one one-year longitudinal assessments of blood DC in patients with early (stage I/II, n=137) and advanced (stage IV, n=36) disease compared to healthy controls (n=66). Patients with advanced disease exhibit markedly reduced blood DC counts at diagnosis. Patients with early disease show minimally reduced counts at diagnosis but a prolonged period (1 year) of marked DC suppression after tumour resection. While differing in frequency, DC from both patients with early and advanced disease exhibit reduced expression of CD86 and HLA-DR and decreased immunostimulatory capacities. Finally, by comparing a range of clinically available maturation stimuli, we demonstrate that conditioning with soluble CD40L induces the highest level of maturation and improved T-cell priming. We conclude that although circulating DC are compromised by loco-regional and systemic breast cancer, they respond vigorously to ex vivo conditioning, thus enhancing their immunostimulatory capacity and potential for immunotherapy.


Lymphatic Research and Biology | 2011

Prevalence and prognostic significance of secondary lymphedema following breast cancer.

Sandi Hayes; Tracey Di Sipio; Sheree Rye; J. Alejandro López; Christobel Saunders; Chris Pyke; John Bashford; Diana Battistutta; Beth Newman

BACKGROUND The adverse consequences of lymphedema following breast cancer in relation to physical function and quality of life are clear; however, its potential relationship with survival has not been investigated. Our purpose was to determine the prevalence of lymphedema and associated upper-body symptoms at 6 years following breast cancer and to examine the prognostic significance of lymphedema with respect to overall 6-year survival (OS). METHODS AND RESULTS A population-based sample of Australian women (n = 287) diagnosed with invasive, unilateral breast cancer was followed for a median of 6.6 years and prospectively assessed for lymphedema (using bioimpedance spectroscopy [BIS], sum of arm circumferences [SOAC], and self-reported arm swelling), a range of upper-body symptoms, and vital status. OS was measured from date of diagnosis to date of death or last follow-up. Kaplan-Meier methods were used to calculate OS and Cox proportional hazards models quantified the risk associated with lymphedema. Approximately 45% of women had reported at least one moderate to extreme symptom at 6.6 years postdiagnosis, while 34% had shown clinical evidence of lymphedema, and 48% reported arm swelling at least once since baseline assessment. A total of 27 (9.4%) women died during the follow-up period, and lymphedema, diagnosed by BIS or SOAC between 6-18 months postdiagnosis, predicted mortality (BIS: HR = 2.5; 95% CI: 0.9, 6.8, p = 0.08; SOAC: 3.0; 95% CI: 1.1, 8.7, p = 0.04). There was no association (HR = 1.2; 95% CI: 0.5, 2.6, p = 0.68) between self-reported arm swelling and OS. CONCLUSIONS These findings suggest that lymphedema may influence survival following breast cancer treatment and warrant further investigation in other cancer cohorts and explication of a potential underlying biology.


Asian Pacific Journal of Cancer Prevention | 2013

Factors predictive of treatment by Australian breast surgeons of invasive female breast cancer by mastectomy rather than breast conserving surgery

David Roder; Helen Zorbas; James Kollias; Chris Pyke; David Walters; Ian Campbell; Corey Taylor; Fleur Webster

BACKGROUND The National Breast Cancer Audit Database of the Society of Breast Surgeons of Australia and New Zealand is used by surgeons to monitor treatment quality and for research. About 60% of early invasive female breast cancers in Australia are recorded. The objectives of this study are: (1) to investigate associations of socio-demographic, health-system and clinical characteristics with treatment of invasive female breast cancer by mastectomy compared with breast conserving surgery; and (2) to consider service delivery implications. MATERIALS AND METHODS Bi-variable and multivariable analyses of associations of characteristics with surgery type for cancers diagnosed in 1998-2010. RESULTS Of 30,299 invasive cases analysed, 11,729 (39%) were treated by mastectomy as opposed to breast conserving surgery. This proportion did not vary by diagnostic year (p>0.200). With major city residence as the reference category, the relative rate (95% confidence limits) of mastectomy was 1.03 (0.99, 1.07) for women from inner regional areas and 1.05 (1.01, 1.10) for those from more remote areas. Low annual surgeon case load (<10) was predictive of mastectomy, with a relative rate of 1.08 (1.03, 1.14) when compared with higher case loads. Tumour size was also predictive, with a relative rate of 1.05 (1.01, 1.10) for large cancers (40+ mm) compared with smaller cancers (<30 mm). These associations were confirmed in multiple logistic regression analysis. CONCLUSIONS Results confirm previous studies showing higher mastectomy rates for residents of more remote areas, those treated by surgeons with low case loads, and those with large cancers. Reasons require further study, including possible effects of surgeon and womans choice and access to radiotherapy services.


BMC Cancer | 2015

Weight and weight change following breast cancer: evidence from a prospective, population-based, breast cancer cohort study

Dimitrios Vagenas; Tracey DiSipio; Diana Battistutta; Wendy Demark-Wahnefried; Sheree Rye; John Bashford; Chris Pyke; Christobel Saunders; Sandra C. Hayes

BackgroundWhile weight gain following breast cancer is considered common, results supporting these findings are dated. This work describes changes in body weight following breast cancer over 72 months, compares weight with normative data and explores whether weight changes over time are associated with personal, diagnostic, treatment or behavioral characteristics.MethodsA population-based sample of 287 Australian women diagnosed with early-stage invasive breast cancer was assessed prospectively at six, 12, 18 and 72 months post-surgery. Weight was clinically measured and linear mixed models were used to explore associations between weight and participant characteristics (collected via self-administered questionnaire). Those with BMI changes of one or more units were considered to have experienced clinically significant changes in weight.ResultsMore than half (57%) of participants were overweight or obese at 6 months post-surgery, and by 72 months post-surgery 68% of women were overweight or obese. Among those who gained more weight than age-matched norms, clinically significant weight gain between 6 and 18 months and 6 and 72 months post-surgery was observed in 24% and 39% of participants, respectively (median [range] weight gain: 3.9 kg [2.0-11.3 kg] and 5.2 kg [0.6-28.7], respectively). Clinically-significant weight losses were observed in up to 24% of the sample (median [range] weight loss between 6 and 72 months post-surgery: −6.4 kg [−1.9--24.6 kg]). More extensive lymph node removal, being treated on the non-dominant side, receiving radiation therapy and lower physical activity levels at 6 months was associated with higher body weights post-breast cancer (group differences >3 kg; all p < 0.05).ConclusionsWhile average weight gain among breast cancer survivors in the long-term is small, subgroups of women experience greater gains linked with adverse health and above that experienced by age-matched counterparts. Weight change post-breast cancer is a contemporary public health issue and the integration of healthy weight education and support into standard breast cancer care has potential to significantly improve the length and quality of cancer survivorship.


Cytotherapy | 2004

The immune response to breast cancer, and the case for DC immunotherapy

Christopher Paul Allan; Cameron J. Turtle; Paul N. Mainwaring; Chris Pyke; Derek N. J. Hart

The long-held belief that breast cancer is a weakly immunogenic tumor and a poor candidate for immunotherapy should be reappraised. There is ample evidence for the existence of an immune response, which is, however, attenuated by multiple inhibitory factors. Many tumor-associated antigens (TAA) have been identified in breast cancer, some of which appear to play a critical role in tumorigenesis and may be attractive targets for immunotherapy. There is evidence for DC recruitment and activation within breast cancers, and the presence of intratumoral activated DCs impacts favorably upon survival. Furthermore, there is a striking paucity of activated DCs within the primary draining or sentinel lymph nodes of breast cancers. Tumor infiltrating lymphocytes (TIL) are often documented, however, their function is impaired by inhibitory cytokines, increased regulatory T lymphocyte activity, tumor cell MHC molecule alterations, and aberrant Fas ligand expression, amongst others. DCs are recognized as one of the critical interfaces between a cancer and the immune system, and have emerged as a promising platform for cancer vaccination via ex vivo immunomodulation. Clinical evaluation of DC vaccination in breast cancer is still relatively limited, although evolving. This article details evidence for the immune response in breast cancer and its many failings, and reviews the clinical trials and significant preclinical data which, taken together, validate the concept of DC vaccination in breast cancer.


The Breast | 2013

Factors predictive of immediate breast reconstruction following mastectomy for invasive breast cancer in Australia

David Roder; Helen Zorbas; Jim Kollias; Chris Pyke; David Walters; Ian D. Campbell; Corey Taylor; Fleur Webster

PURPOSE To investigate person, cancer and treatment determinants of immediate breast reconstruction (IBR) in Australia. METHODS Bi-variable and multi-variable analyses of the Quality Audit database. RESULTS Of 12,707 invasive cancers treated by mastectomy circa 1998-2010, 8% had IBR. This proportion increased over time and reduced from 29% in women below 30 years to approximately 1% in those aged 70 years or more. Multiple regression indicated that other IBR predictors included: high socio-economic status; private health insurance; being asymptomatic; a metropolitan rather than inner regional treatment centre; higher surgeon case load; small tumour size; negative nodal status, positive progesterone receptor status; more cancer foci; multiple affected breast quadrants; synchronous bilateral cancer; not having neo-adjuvant chemotherapy, adjuvant radiotherapy or adjuvant hormone therapy; and receiving ovarian ablation. CONCLUSIONS Variations in access to specialty services and other possible causes of variations in IBR rates need further investigation.


Contemporary Clinical Trials | 2011

Design and implementation of the Exercise for Health trial - A pragmatic exercise intervention for women with breast cancer

Sandra C. Hayes; Sheree Rye; Diana Battistutta; Patsy Yates; Chris Pyke; John Bashford; Elizabeth G. Eakin

BACKGROUND Exercise for Health was a pragmatic, randomised, controlled trial comparing the effect of an eight-month exercise intervention on function, treatment-related side effects and quality of life following breast cancer, compared with usual care. The intervention commenced six weeks post-surgery, and two modes of delivering the same intervention was compared with usual care. The purpose of this paper is to describe the study design, along with outcomes related to recruitment, retention and representativeness, and intervention participation. METHODS Women newly diagnosed with breast cancer and residing in a major metropolitan city of Queensland, Australia, were eligible to participate. Consenting women were randomised to a face-to-face-delivered exercise group (FtF, n = 67), telephone-delivered exercise group (Tel, n = 67) or usual care group (UC, n = 60) and were assessed pre-intervention (5-weeks post-surgery), mid-intervention (6 months post-surgery) and 10 weeks post-intervention (12 months post-surgery). Each intervention arm entailed 16 sessions with an Exercise Physiologist. RESULTS Of 318 potentially eligible women, 63% (n = 200) agreed to participate, with a 12-month retention rate of 93%. Participants were similar to the Queensland breast cancer population with respect to disease characteristics, and the randomisation procedure was mostly successful at attaining group balance, with the few minor imbalances observed unlikely to influence intervention effects given balance in other related characteristics. Median participation was 14 (min and max: 0 and 16) and 13 (min and max: 3 and 16) intervention sessions for the FtF and Tel, respectively, with 68% of those in Tel and 82% in FtF participating in at least 75% of sessions. DISCUSSION Participation in both intervention arms during and following treatment for breast cancer was feasible and acceptable to women. Future work, designed to inform translation into practice, will evaluate the quality of life, clinical, psychosocial and behavioural outcomes associated with each mode of delivery.


Tissue Antigens | 2005

A Population of HLA-DR+ Immature Cells Accumulate in the Blood Dendritic Cell Compartment of Patients with Different Types of Cancer

Alberto Pinzon-Charry; Christopher S. K. Ho; Richard Laherty; Tammy Maxwell; David Walker; Robert A. Gardiner; Linda O'Connor; Chris Pyke; Christopher W. Schmidt; Colin Furnival; José A. López

Induction of immune cell death is one of the many mechanisms used by tumors to evade immune recognition. Here we assessed for the presence of spontaneous apoptosis in blood dendritic cells (DC; LinHLA-DR+ cells) from patients with breast cancer. We document the presence of a significantly (p < 0.05) higher proportion of apoptotic (Annexin-V+ and TUNEL+) blood DC in patients with early stage breast cancer (Stage I-II; n ¼ 13) compared to healthy volunteers (n ¼ 15). We examined the role of tumor products on this phenomenon and show that supernatants derived from breast cancer lines induce apoptosis of blood DC in PBMC cultures. Aiming to identify factors that protect these cells from apoptosis, we then compared a range of clinically available maturation stimuli including, inflammatory cytokines (TNF- a, IL-1 b, IL-6 and PGE 2; CC); synthetic double stranded RNA (poly I:C) and soluble CD40 ligand. While inflammatory cytokines and poly I:C induced robust phenotypic maturation, they failed to protect blood DC from apoptosis. In contrast, CD40 stimulation induced strong up-regulation of the antigen presenting machinery, secretion of IL-12 and protected blood DC through sustained expression of Bcl-2. Exogenous IL-12 also protected blood DC from apoptosis through sustained expression of Bcl-2, suggesting that CD40L-protection could be mediated, at least in part, through IL-12 secretion. Cumulatively our results demonstrate spontaneous apoptosis of blood DC in patients with breast cancer and confirm that ex vivo conditioning of blood DC can protect them from tumor-induced apoptosis.Diverse infectious and inflammatory environmental triggers, through unknown mechanisms, initiate autoimmune disease in genetically predisposed individuals. Here we show that IL-1b, a key cytokine mediator of the inflammatory response, suppresses CD25+CD4+ regulatory T cell function. Surprisingly, suppression by IL-1b occurs only where antigen is presented simultaneously to CD25+CD4+ T cells and to CD25CD4+ antigen-specific effector T cells. Further, NOD mice show an intrinsic over-production of IL-1 that contributes to reduced CD25+CD4+ regulatory T cell function. Thus, inflammation or constitutive over-expression of IL-1b in a genetically predisposed host can initiate a positive feedback loop licensing autoantigen-specific effector cells to inhibit the regulatory T cells maintaining tolerance to self.Dendritic cells (DC) are the potent antigen presenting cells which modulate T cell responses to self or non-self antigens. DC play a significant role in the pathogenesis of autoimmune diseases, inflammation and infection, but also in the maintenance of tolerance. NF-kappaB, particularly RelB is a crucial pathway for myeloid DC differentiation and functional maturation. While the current paradigm is that mature, nuclear RelB+ DC prime T cells for immunity/autoimmunity and immature DC for tolerance, RelB-deficient mice paradoxically develop generalised systemic autoimmune inflammatory disease with myelopoiesis and splenomegaly. Previous studies suggested abnormal DC differentiation in healthy relatives of type 1 diabetes (t1dm) patients. Therefore, we compared NF- kB activation in monocyte-derived DC from t1dm and non-t1dm controls in response to LPS. While resting DC appeared normal, DC from 6 out of 7 t1dm patients but no t2dm or rheumatoid arthritis patients failed to translocate NF- kB subunits to the nucleus in response to LPS, along with a failure to up-regulate expression of cell surface CD40 and MHC class I. NF- kB subunit mRNA increased normally in t1dm DC after LPS. Both the classical or non-canonical NF- kB pathways were affected as both TNF-a and CD40 stimulation led to a similarly abnormal NF- kB response. In contrast, expression of phosphorylated p38 MAPK and pro-inflammatory cytokine production was intact. These abnormalities in NF- kB activation appear to be generally and specifically applicable at a post-translational level in t1dm, and have the capacity to profoundly influence immunoregulation in affected individuals.The delivery of exogenous antigen to antigen presenting cells (APC) for processing and presentation is the first step in the generation of immune responses. We have utilized mannan or mannose as a vehicle to target protein and peptide antigens to mannose binding receptors on antigen presenting cells. In these studies antigen (protein or peptides) conjugated to oxidized mannan (OxMan) generated cellular immune responses in mice whilst antigen conjugated to reduced mannan (RedMan) gave humoral immune responses. These differential immune responses are due to the ability of OxMan to deliver exogenous conjugated antigen to the cytoplasm of APC (macrophages and DC). We have now used OxMan and RedMan to deliver DNA and RNA to APC. Mannan conjugates of poly-lysine (PLL) and polyethyleneimine (PEI) successfully complexed with DNA and RNA as evidenced by retardation on agarose gel electrophoresis. OxMan-PEI or PLL complexed with DNA or RNA transfected mannose receptor expressing J774 cells as well as bone marrow-derived dendritic cells. Mice immunized with OxMan-PLL-DNA conjugate were protected from a challenge of OVA expressing tumour cells. The combination of mannose receptor targeting and immunomodulating properties of OxMan results in an excellent adjuvant/delivery system.Cancer immunotherapy trials conducted over the last few years have concentrated on the analysis of immunological markers of response to antigenically well defined vaccines. Improvements in the quantity or quality of T cell responses, in a patient population, are proposed to allow a rational basis for improved clinical outcomes. However, using current methodologies, only weak immune correlates of clinical response have been found. Further, little attention has been given to other patient or tumour characteristics predisposing to favourable clinical responses following immunotherapy. Establishing such correlates is fundamental to understanding how vaccines work. We have followed this line of investigation with a matured, autologous, dendritic cell/irradiated melanoma cell vaccine for Stage IV melanoma patientsMost of the skin grafts from (K14hGH.FVB C57BL/6) F1 mice, which express foreign antigen (human growth hormone, hGH) in skin keratinocytes driven by keratin 14 promoter, were spontaneously rejected by syngeneic wild type F1 recipients and hGH-specific immune responses such as antibody and hGHspecific T cells were generated in these recipients. Interestingly, a 2nd F1 hGH-expressing skin graft was rejected by graft primed recipients, but was not rejected from such recipients if CD4+ or CD8+ T cells were depleted prior to the placement of the 2nd graft. Surprisingly, this 2nd graft retained healthy even after CD4+ or CD8+ T cells were allowed to recover so that the animal could reject a freshly placed 3rd F1 hGH-expressing graft. Furthermore, inflammatory response induced by topical treatment with imiquimod could lead to the rejection of some well-healed 2nd grafts. This result indicates that both CD4+ and CD8+ T cells are required for the rejection and the ability of effector T cells to reject a graft is determined by local factors in the graft which are presumably determined by inflammation induced by surgery or imiquimod treatment. Taken together, our results suggest that in addition to CD4+ and CD8+ T cells, local environmental factors induced by inflammation are also crucial for effector T cell functions leading to graft destruction. The understanding of these local factors will lead to more effective immunotherapy for established, epithelial cancer in the future.Inhibition of NFkB by the compound Bay 11–7082 (Bay) induces tolerogenic properties in dendritic cells (DC). While activation of NFkB can be induced by reactive oxygen species (ROS) and thiol/disulfide redox states, the consequences of NFkB blockade on ROS/redox state is not known. To generate immature DC, monocytes were cultured in GM-CSF and IL-4 (with or without Bay) for 48 h. Genes potentially involved in redox regulation were determined using microarray technology and validated using FACS, real-time PCR or western blotting. ROS were measured using two fluorescent dyes DHR-123 and DHE (to detect H2O2 or O2 respectively). We found increased expression of genes associated with reductants such as thioredoxin reductase (TrxR1) and glutathione (GSH), although those associated with the breakdown of H2O2 such as glutathione peroxidase, peroxiredoxins and catalase were decreased. Interestingly, Bay-treated DC produced less ROS in comparison to control DC under basal conditions and following stimulation with various pro-oxidants. In conclusion, Bay-treated DC display not only tolerogenic properties but also an intracellular reducing environment and an impaired ability to produce ROS. We are currently investigating whether exogenous ROS can interfere with the tolerogenic properties of Bay-treated DC.


Asian Pacific Journal of Cancer Prevention | 2012

Survival From Synchronous Bilateral Breast Cancer: The Experience of Surgeons Participating in the Breast Audit of the Society of Breast Surgeons of Australia and New Zealand

David Roder; Primali de Silva; Helen Zorbas; James Kollias; Peter Malycha; Chris Pyke; Ian Campbell; Fleur Webster

BACKGROUND Previous studies generally indicate that synchronous bilateral breast cancers (SBBC) have an equivalent or moderately poorer survival compared with unilateral cases. The prognostic characteristics of SBBC would be relevant when planning adjuvant therapies and follow-up medical surveillance. The frequency of SBBC among early breast cancers in clinical settings in Australia and New Zealand were investigated, plus their prognostic significance, using the Breast Cancer Audit Database of the Society of Breast Surgeons of Australia and New Zealand, which covered an estimated 60% of early invasive lesions in those countries. DESIGN Rate ratios (95% confidence limits) of SBBC were investigated among 35,370 female breast cancer cases by age of woman, histology type, grade, tumour diameter, nodal status, lymphatic/vascular invasion and oestrogen receptor status. Univariate and multivariable disease-specific survival analyses were undertaken. RESULTS 2.3% of cases were found to be SBBC (i.e., diagnoses occurring within 3 months). The figure increased from 1.4% in women less than 40 years to 4.1% in those aged 80 years or more. Disease-specific survivals did not vary by SBBC status (p=0.206). After adjusting for age, histology type, diameter, grade, nodal status, lymphatic/vascular invasion, and oestrogen receptor status, the relative risk of breast cancer death for SBBC was 1.17 (95% CL: 0.91, 1.51). After adjusting for favourable prognostic factors more common in SBBC cases (i.e., histology type, grade, lymphatic/ vascular invasion, and oestrogen receptor status), the relative risk of breast cancer death for SBBC was 1.42 (95% CL: 1.10, 1.82). After adjusting for unfavourable prognostic factors more common in SBBC cases (i.e., older age and large tumour diameter), the relative risk of breast cancer death for SBBC was 0.98 (95% CL: 0.76, 1.26). CONCLUSIONS Results confirm previous findings of an equivalent or moderately poorer survival for SBBC but indicate that SBBC status is likely to be an important prognostic indicator for some cases.

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Diana Battistutta

Queensland University of Technology

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Christobel Saunders

University of Western Australia

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Sandra C. Hayes

Queensland University of Technology

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David Roder

University of South Australia

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Helen Zorbas

Royal Australasian College of Surgeons

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Sheree Rye

Queensland University of Technology

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Peter Baade

Cancer Council Queensland

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