The role of aging in cancer.

Many cancers show an increase in incidence with age, and age is the biggest single risk factor for many cancers. However, the molecular basis of this relationship is poorly understood. Through a collection of review articles, our thematic issue discusses the link between aging and cancer in aspects including somatic mutations, proteostasis, mitochondria, metabolism, senescence, epigenetic regulation, immune regulation, DNA damage, and telomere function.

Quantifying Brain Iron in Hereditary Hemochromatosis Using R2* and Susceptibility Mapping.

BACKGROUND AND PURPOSE: Brain iron dyshomeostasis is increasingly recognized as an important contributor to neurodegeneration. Hereditary hemochromatosis is the most commonly inherited disorder of systemic iron overload. Although there is an increasing interest in excessive brain iron deposition, there is a paucity of evidence showing changes in brain iron exceeding that in healthy controls. Quantitative susceptibility mapping and R2* mapping are established MR imaging techniques that we used to noninvasively quantify brain iron in subjects with hereditary hemochromatosis. MATERIALS AND METHODS: Fifty-two patients with hereditary hemochromatosis and 47 age- and sex-matched healthy controls were imaged using a multiecho gradient-echo sequence at 3T. Quantitative susceptibility mapping and R2* data were generated, and regions within the deep gray matter were manually segmented. Mean susceptibility and R2* relaxation rates were calculated for each region, and iron content was compared between the groups. RESULTS: We noted elevated iron levels in patients with hereditary hemochromatosis compared with healthy controls using both R2* and QSM methods in the caudate nucleus, putamen, pulvinar thalamus, red nucleus, and dentate nucleus. Additionally, the substantia nigra showed increased susceptibility while the thalamus showed an increased R2* relaxation rate compared with healthy controls, respectively. CONCLUSIONS: Both quantitative susceptibility mapping and R2* showed abnormal levels of brain iron in subjects with hereditary hemochromatosis compared with controls. Quantitative susceptibility mapping and R2* can be acquired in a single MR imaging sequence and are complementary in quantifying deep gray matter iron.

SP rTaTME: initial clinical experience with single-port robotic transanal total mesorectal excision (SP rTaTME).

BACKGROUND: The technical difficulty and steep learning curve of transanal total mesorectal excision (taTME) has limited widespread adoption. The single-port (SP) daVinci robot is designed to facilitate single-incision and natural-orifice transluminal endoscopic surgery (NOTES). This paper describes the first clinical experience of single-port robotic taTME (SP rTaTME). METHODS: This was a prospective study on consecutive patients with rectal cancer who underwent SP rTaTME proctosigmoidectomy with handsewn coloanal anastomosis in December 2018 and January 2019. The primary outcome was technical feasibility of the procedure. The secondary outcomes include blood loss, intraoperative complications, length of hospital stay, quality of the TME specimen, short- and long-term morbidity and mortality, as well as short-term oncologic follow -up. RESULTS: There were two patients, a 48-year-old male and a 38-year-old female. Both operations were completed successfully without complications or conversion. Estimated blood loss was 200 mL and 130 mL. In both cases the TME was completed transanally using the SP robot. In the first patient, the abdominal portion was completed through an abdominal single-incision; in the second patient the operation was entirely performed transanally as a pure NOTES procedure. In both cases, the final pathology report showed a complete TME with negative margins. Patients were discharged on postoperative day 3 and 4,respectively. There was no long-term morbidity or mortality. CONCLUSIONS: SP rTaTME is feasible and can be safely performed. It provides excellent optics and dexterity to work in a limited space. Future studies are required to further define the safety profile and the ultimate utility of the SP robot for taTME.

Correção de fratura Salter-Harris tipo I em porquinho-da-índia (Cavia porcellus) - relato de caso / [Correction of Salter-Harris type 1 fracture in guinea pig (Cavia porcellus) - case report]

Um filhote de porquinho-da-índia (Cavia porcellus) foi recebido para atendimento após histórico de ataque por cão. Na avaliação física, observou-se edema, dor e crepitação em membro pélvico direito, sugestivo de fratura. Na avaliação radiográfica, confirmou-se fratura Salter-Harris tipo I em epífise distal da tíbia. A resolução cirúrgica escolhida foi a associação de pino transarticular e coaptação externa com tala de Altman. O paciente teve acompanhamento radiográfico semanal e obteve alta médica no 35o dia de pós-cirúrgico, quando se observou consolidação com completo remodelamento ósseo.(AU)

A guinea pig (Cavia porcellus) cub presented edema, pain, and crepitus in the right pelvic limb after being attacked by a dog. Radiographic examination revealed Salter-Harris type 1 fracture on the distal region of the tibia. The surgery technique to correct the fracture involved an association of transarticular pinning and external coaptation with Altman splint. After surgery, radiographs of the patient were performed weekly and on the 35th post-surgery day, the bone was completely remodeled and healed, and the animal was dismissed.(AU)

AKT overactivation can suppress DNA repair via p70S6 kinase-dependent downregulation of MRE11.

Deregulated AKT kinase activity due to PTEN deficiency in cancer cells contributes to oncogenesis by incompletely understood mechanisms. Here, we show that PTEN deletion in HCT116 and DLD1 colon carcinoma cells leads to suppression of CHK1 and CHK2 activation in response to irradiation, impaired G2 checkpoint proficiency and radiosensitization. These defects are associated with reduced expression of MRE11, RAD50 and NBS1, components of the apical MRE11/RAD50/NBS1 (MRN) DNA damage response complex. Consistent with reduced MRN complex function, PTEN-deficient cells fail to resect DNA double-strand breaks efficiently after irradiation and show greatly diminished proficiency for DNA repair via the error-free homologous recombination (HR) repair pathway. MRE11 is highly unstable in PTEN-deficient cells but stability can be significantly restored by inhibiting mTORC1 or p70S6 kinase (p70S6K), downstream kinases whose activities are stimulated by AKT, or by mutating a residue in MRE11 that we show is phosphorylated by p70S6K in vitro. In primary human fibroblasts, activated AKT suppresses MRN complex expression to escalate RAS-induced DNA damage and thereby reinforce oncogene-induced senescence. Taken together, our data demonstrate that deregulation of the PI3K-AKT/ mTORC1/ p70S6K pathways, an event frequently observed in cancer, exert profound effects on genome stability via MRE11 with potential implications for tumour initiation and therapy.

Epidemiology and diagnostic testing for hemochromatosis and iron overload.

Hemochromatosis is the most common genetic disease in northern European populations. Body iron stores progressively increase in most patients, which can lead to cirrhosis of the liver, hepatocellular carcinoma, heart failure, arthritis, and pigmentation. Simple blood tests such as the serum ferritin and transferrin saturation are useful to suggest the diagnosis which can be confirmed in most cases with a simple genetic test for the C282Y mutation of the HFE gene. However, these blood tests are often misinterpreted and there are rare patients with iron overload without HFE mutations. A diagnostic approach is presented based on a large referral practice and a population-based study (HEIRS) which screened for iron overload in 101,168 participants.

Fasciola hepatica tegumental antigens indirectly induce an M2 macrophage-like phenotype in vivo.

The M2 subset of macrophages has a critical role to play in host tissue repair, tissue fibrosis and modulation of adaptive immunity during helminth infection. Infection with the helminth, Fasciola hepatica, is associated with M2 macrophages in its mammalian host, and this response is mimicked by its excretory-secretory products (FhES). The tegumental coat of F. hepatica (FhTeg) is another major source of immune-modulatory molecules; we have previously shown that FhTeg can modulate the activity of both dendritic cells and mast cells inhibiting their ability to prime a Th1 immune response. Here, we report that FhTeg does not induce Th2 immune responses but can induce M2-like phenotype in vivo that modulates cytokine production from CD4(+) cells in response to anti-CD3 stimulation. FhTeg induces a RELMα expressing macrophage population in vitro, while in vivo, the expression of Arg1 and Ym-1/2 but not RELMα in FhTeg-stimulated macrophages was STAT6 dependent. To support this finding, FhTeg induces RELMα expression in vivo prior to the induction of IL-13. FhTeg can induce IL-13-producing peritoneal macrophages following intraperitoneal injection This study highlights the important role of FhTeg as an immune-modulatory source during F. hepatica infection and sheds further light on helminth-macrophage interactions.

Phase II trial of vorinostat in advanced melanoma.

INTRODUCTION: Vorinostat is a small molecule inhibitor of class I and II histone deacetylases with preclinical activity in melanoma. METHODS: We evaluated 32 patients with advanced primary cutaneous or ocular melanoma in a multi-institutional setting (PMH Phase II Consortium) with continuous daily oral vorinostat 400 mg. The primary endpoint was response rate by RECIST, with time to progression as a secondary endpoint. The study was designed to distinguish a response rate of 20 % from a RR of 5 % and to distinguish a 2 month median progression-free survival (PFS), from one of 3.1 months. The study proceeded to stage 2 following 2 of 16 responses.. We also assessed VEGF, FGF levels, P52 polymorphisms and chromatin-associated proteins as potential biomarkers. RESULTS: Therapy was associated with significant side effects, including fatigue, nausea, lymphopenia, and hyperglycemia. Eleven patients experienced at least one grade 3 or higher adverse event. There were two confirmed PRs in patients with cutaneous melanoma. Sixteen patients had stable disease and 14 patients had progressive disease for best response. In addition, two patients with cutaneous melanoma scored as stable disease had early unconfirmed partial responses with subsequent progression. Patients with stable disease or partial response (n = 18) had a median progression free survival of 5 months. (range 2-12 months). CONCLUSIONS: Vorinostat demonstrated some early responses and a high proportion of patients with stable disease, but did not meet its primary endpoint of response. Different schedules of this agent with BRAF mutation status and markers of histone acetylation could be explored in melanoma.

EZH2 in normal and malignant hematopoiesis.

The histone methyltransferase Enhancer of Zeste Homologue 2 (EZH2), a component of the polycomb group complex, is vital for stem cell development, including hematopoiesis. Its primary function, to deposit the histone mark H3K27me3, promotes transcriptional repression. The activity of EZH2 influences cell fate regulation, namely the balance between self-renewal and differentiation. The contribution of aberrant EZH2 expression to tumorigenesis by directing cells toward a cancer stem cell (CSC) state is increasingly recognized. However, its role in hematological malignancies is complex. Point mutations, resulting in gain-of-function, and inactivating mutations, reported in lymphoma and leukemia, respectively, suggest that EZH2 may serve a dual purpose as an oncogene and tumor-suppressor gene. The reduction of CSC self-renewal via EZH2 inhibition offers a potentially attractive therapeutic approach to counter the aberrant activation found in lymphoma and leukemia. The discovery of small molecules that specifically inhibit EZH2 raises the exciting possibility of exploiting the oncogenic addiction of tumor cells toward this protein. However, interference with the tumor-suppressor role of wild-type EZH2 must be avoided. This review examines the role of EZH2 in normal and malignant hematopoiesis and recent developments in harnessing the therapeutic potential of EZH2 inhibition.

Fasciola hepatica tegumental coat antigen suppresses MAPK signalling in dendritic cells and up-regulates the expression of SOCS3.

Fasciola hepatica tegumental coat antigen (FhTeg) suppresses dendritic cell maturation and function by inhibiting IL-6, tumour necrosis factor (TNF)-α, IL-10 and IL-12 production and CD80, CD86 and CD40 cell surface marker expression in TLR4-stimulated dendritic cells. Fasciola hepatica also impairs dendritic cell function by inhibiting its phagocytic capacity and its ability to prime T cells. We have shown previously that activation of mast cells with bacterial ligands is also inhibited by FhTeg. Fasciola hepatica suppresses LPS-induced NF-κB and MAPK pathway (ERK) activation in these cells. Previously, we demonstrated that FhTeg induces expression of suppressor of cytokine signalling (SOCS)3, a negative regulator of the TLR pathway in mast cells. In this study, we show the same inhibitory effect of FhTeg on the activation of the other members of the MAPKs pathway (ERK, p38, JNK) in dendritic cells and demonstrate an enhanced expression of SOCS3, but not SOCS1, SOCS5 or PIAS3 in this process. These studies enhance our understanding of the immunomodulatory effect of helminth molecules on the TLR pathway.

Phase II clinical trial of phlebotomy for non-alcoholic fatty liver disease.

BACKGROUND: Elevated iron indices are described in non-alcoholic fatty liver disease and iron reduction has been suggested as a potential therapy. AIM: To determine whether phlebotomy is an effective therapy for non-alcoholic fatty liver disease. METHODS: Patients with biopsy proven non-alcoholic fatty liver disease underwent baseline evaluation to determine severity of metabolic and liver disease. A Phase II trial of phlebotomy was carried out to achieve near-iron depletion (serum ferritin ≤50 µg/L or haemoglobin 100 g/L). Repeat liver biopsy, anthropometric and biochemical measurements were performed 6 months following the end of treatment. Primary outcome was improvement in liver histology, assessed using the non-alcoholic fatty liver disease activity score. RESULTS: Thirty-one patients completed follow-up. Iron reduction resulted in a significant improvement in the non-alcoholic fatty liver disease activity score (-0.74 ± 1.83, P = 0.019). Reductions in individual histological features of lobular inflammation (-0.29 ± 1.07, P = 0.182), steatosis (-0.26 ± 0.82, P = 0.134), hepatocyte ballooning (-0.19 ± 0.70, P = 0.213) did not achieve significance nor did the score for fibrosis (-0.32 ± 0.94, P = 0.099). CONCLUSIONS: This prospective Phase II study of phlebotomy with paired liver biopsies evaluating phlebotomy therapy in non-alcoholic fatty liver disease patients suggests that iron reduction may improve liver histology. However, the effect size of phlebotomy raises questions of whether treatment could have sufficient clinical significance to justify a definitive Phase III trial. This trial has been registered with the US National Institute of Health (clinicaltrials.gov, Identifier NCT 00641524).

Clickable enzyme-linked immunosorbent assay.

Click chemistry is explored as a potential cost-effective and selective immobilization method for the production of an enzyme-linked immunosorbent assay (ELISA). Coatings were formulated containing either a terminal alkyne or a bicyclo[6.1.0]non-4-yne (BCN) chemical handle, and a diagnostic peptide was subsequently immobilized onto these coatings by the copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) or copper-free strain-promoted azide-alkyne 1,3-dipolar cycloaddition (SPAAC), respectively. The terminal alkyne-containing coating showed high background levels in subsequent ELISA's due to the copper catalyst used in the immobilization step. The BCN-containing coating, however, was successfully employed and presents a cost-effective alternative to existing (strept)avidin-biotin immobilization methods. This technology was illustrated with an ELISA used for the diagnosis of rheumatoid arthritis (RA) but could be easily applied to a wide range of diagnostic tests.

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums.

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 µm diameter hot core.

De novo thrombotic microangiopathy in renal allograft biopsies-role of antibody-mediated rejection.

The most common cause of thrombotic microangiopathy (TMA) in renal allografts is thought to be calcineurin inhibitor toxicity. Antibody-mediated rejection (AMR) can also cause TMA, but its true impact on de novo TMA is unknown. In a retrospective review of renal allograft biopsies from January 2003 to December 2008 at our institution, we determined the prevalence of TMA in patients with C4d positive (n = 243) and C4d negative (n = 715) biopsies. Over 90% of patients received cyclosporine in both groups. De novo TMA was seen in 59 (6.1%) patients; most of them (55%) with C4d positive biopsy. Among patients with C4d positive biopsies, 13.6% had TMA, as compared to only 3.6% patients with C4d negative biopsies (p < 0.0001). Incidence of graft loss between C4d positive and C4d negative TMA groups was not significantly different, but 70% of patients with C4d positive TMA who received plasmapheresis had slightly lower graft loss rate. In biopsies with AMR-associated TMA, glomerulitis and peritubular capillaritis were significantly more prominent. AMR is the most common cause of TMA in renal allografts in our patient population. It is important to recognize AMR-related TMA because plasmapheresis treatment may be beneficial.

Estimation of an optimal utilisation rate for palliative radiotherapy in newly diagnosed cancer patients.

AIMS: An optimal utilisation rate for palliative radiotherapy in newly diagnosed cancers will be useful in the planning and delivery of cancer services and has not been reported to date. The aim of this study was to estimate the proportion of new cases of cancer that should receive palliative radiotherapy as their first course of radiotherapy at some time during the course of their illness. MATERIALS AND METHODS: A previously developed model depicting indications for radiotherapy was merged with Australian cancer epidemiological data and re-analysed to identify palliative or radical treatment end points. Palliative radiotherapy end points were further divided by treatment site. The optimal palliative radiotherapy utilisation rates were compared with actual radiotherapy utilisation data for newly diagnosed cancers. RESULTS: Fourteen per cent of all new cancer cases should optimally receive palliative radiotherapy as their first course of radiotherapy treatment. Comparisons with actual radiotherapy utilisation rates from New South Wales, Australia, show that for some common cancers, more newly diagnosed patients receive palliative radiotherapy as their first radiotherapy treatment than would be optimally recommended in this model. This suggests that many patients in New South Wales are not currently being referred for curative treatment. CONCLUSION: Palliative radiotherapy is optimally recommended as the first course of radiotherapy in 14% of all newly diagnosed cancers.

Time to endoscopy and outcomes in upper gastrointestinal bleeding.

BACKGROUND: Upper gastrointestinal bleeding (UGIB) is a common problem associated with significant morbidity and mortality. Previous studies show that immediate endoscopies do not affect outcomes in patients; however, endoscopic interventions have evolved. The present retrospective review of endoscopies performed at a large teaching hospital assessed the timing of endoscopy with respect to the morbidity and mortality of UGIB. METHODS: Diagnostic billing codes were used to assess all inpatients of gastroenterologists at the University Hospital of the London Health Sciences Centre, London, Ontario, from July 2004 to June 2006, using a centralized data recording system. Time to endoscopy (within 6 h, 6 h to 24 h and beyond 24 h) were compared for the outcomes of mortality, need for surgery and transfusion requirements. RESULTS: From July 2004 to June 2006, there were 502 upper endoscopies performed for the indication of suspected UGIB and 375 for overt acute nonvariceal UGIB. Approximately 10% of cases revealed variceal bleeding. When comparing endoscopy within 6 h with endoscopy at 6 h to 24 h, there were no significant differences in mortality, need for surgery (OR 3.6 and 2.8, respectively, compared with endoscopy beyond 24 h) or transfusion requirements. Even when assessing the group that received endoscopic hemostasis, time to endoscopy was not associated with better outcomes. Multivariate analysis did not demonstrate any advantages for early endoscopy (less than 6 h) compared with endoscopy within 24 h. CONCLUSIONS: Most patients with acute gastrointestinal bleeding can be effectively managed with endoscopy within 24 h.

Variation in physician reimbursement for endoscopy across Canada.

BACKGROUND: Endoscopy accounts for a significant proportion of income for physicians practicing gastroenterology. Fees are set provincially, and the consistency with regard to compensation for colonoscopy and gastroscopy across the provinces has yet to be established. OBJECTIVE: To compare and contrast provincial endoscopy fees across Canada and internationally. METHODS: Provincial and territorial ministries responsible for health care were contacted for their most current fee schedule. This was reviewed, and the billing amounts for colonoscopy and endoscopy collected. International contacts were made with regard to rates outside of Canada. RESULTS: The mean (+/- SD) national fee for gastroscopy was $114.19+/-$31.47 per procedure, with a range of $52.50 to $156.10. Physician billing nationally averaged $170.99+/-$33.49 per colonoscopy procedure, with a range of $105.00 to $223.00. The province of Quebec provided the least amount of compensation for both procedures, and the province of Nova Scotia provided the most for both procedures. CONCLUSION: Physician fees for gastroscopy and colonoscopy vary widely among the provinces, and, on average, seem to be less than international rates.