Quantifying the survival benefit of completing all the six cycles of radium-223 therapy in patients with castrate-resistant prostate cancer with predominant bone metastases.

A retrospective analysis was performed of epidemiological data assessing the survival of patients who had received radium-223 for castrate-resistant metastatic prostate cancer treated at a regional tertiary referral center over a 5-year period. The patients' age, date of first treatment, and the number of cycles of radium-223 given were obtained from the patients' electronic patient record (EPR). Data on the date of death were provided by national death registrations which update the EPR via a unique national health service number. A total of 187 patients (mean age on the date of first treatment: 73 years; range: 56-93) were treated from April 1, 2014, to June 30, 2019. The median overall survival of the 119 patients (71%) who had died by December 31, 2019, was 15 months. There was no significant age difference between those who had died and survivors (72 vs. 74 years). On a further analysis, it was found that the median overall survival of the 107 patients who had received all the six cycles of radium-223 was 31 months, significantly longer than the median overall survival of only 6 months for those eighty patients who had received less than the full course of six cycles of radium-223 (P = 0.001). Of those who received all the six cycles of treatment, 58 patients had died (58%) and the 1-year survival was 87%. This was compared to the group of patients receiving <6 cycles of radium-223 where 61 patients (76%) had died and the 1-year survival was 30%. Therefore, the hazard ratio of dying before 1 year if the patient did not receive all the six cycles of treatment was 2.9. Where the reason for stopping treatment was recorded on the EPR the most common cause for the cessation of treatment was because of the side effects caused by the treatment itself. Other causes were hospitalization with comorbidities, disease progression, or patient choice. Given the survival advantage of receiving the full course of all the six cycles of treatment, this should be administered if possible and the patients should be managed in such a way as to allow the complete treatment course to be given.

Pseudotumours in haemophilia: non-adherence, under-reporting bleeds or bad luck?

Pseudotumours are a rare, severe complication of haemophilia which can occur in a spectrum of bones and soft tissues. It consists of an encapsulated blood collection, and as the swelling increases causes compression and eventual slow destruction of surrounding structures. Presented here are two cases of patients with haemophilia and pseudotumours, which demonstrate the heterogeneity of presenting symptoms and of treatment options.

Targeted Mutation of NGN3 Gene Disrupts Pancreatic Endocrine Cell Development in Pigs.

The domestic pig is an attractive model for biomedical research because of similarities in anatomy and physiology to humans. However, key gaps remain in our understanding of the role of developmental genes in pig, limiting its full potential. In this publication, the role of NEUROGENIN 3 (NGN3), a transcription factor involved in endocrine pancreas development has been investigated by CRISPR/Cas9 gene ablation. Precomplexed Cas9 ribonucleoproteins targeting NGN3 were injected into in vivo derived porcine embryos, and transferred into surrogate females. On day 60 of pregnancy, nine fetuses were collected for genotypic and phenotypic analysis. One of the piglets was identified as an in-frame biallelic knockout (Δ2/Δ2), which showed a loss of putative NGN3-downstream target genes: NEUROD1 and PAX4, as well as insulin, glucagon, somatostatin and pancreatic polypeptide-Y. Fibroblasts from this fetus were used in somatic cell nuclear transfer to generate clonal animals to qualify the effect of mutation on embryonic lethality. Three live piglets were born, received colostrum and suckled normally, but experienced extreme weight loss over a 24 to 36-hour period requiring humane euthanasia. Expression of pancreatic endocrine hormones: insulin, glucagon, and somatostatin were lost. The data support a critical role of NGN3 in porcine endocrine pancreas development.

What Interventions Are Being Used to Prevent Preterm Birth and When?

OBJECTIVE: This study sought to determine the proportions of women at risk of preterm birth who received progesterone, elective and rescue cerclage, or pessary to prevent preterm birth, by using medical records. The authors also sought to determine whether these proportions differed among primary-, secondary-, and tertiary-level centres. METHODS: The authors conducted a retrospective cohort study and extracted data from consecutive medical charts of women with an estimated date of confinement over 3 months in primary-, secondary-, and tertiary-level centres in Southern Ontario. The study identified women with a previous spontaneous preterm birth or a short cervix and determined whether they were offered and whether they received a preventive intervention for preterm birth. Descriptive statistics and Fisher exact tests were calculated. RESULTS: The authors reviewed 1024 consecutive charts at primary, secondary, and tertiary centres and identified 31 women with a previous spontaneous preterm birth or a short cervix. Of these women, less than one half (42%) received progesterone or cerclage for prevention of preterm birth, and none received pessary. One in four women (26%) were not referred to an obstetrician or maternal-fetal medicine specialist in time for an intervention, and among those referred before 24 weeks of gestation, an intervention was offered to 57% of the women. CONCLUSION: Less than half of women at risk of spontaneous preterm birth received progesterone, cerclage, or pessary, attesting to the importance of improving knowledge translation methods to encourage timely referral and use of progesterone for the prevention of preterm birth.

Lrig1+ gastric isthmal progenitor cells restore normal gastric lineage cells during damage recovery in adult mouse stomach.

OBJECTIVE: Lrig1 is a marker of proliferative and quiescent stem cells in the skin and intestine. We examined whether Lrig1-expressing cells are long-lived gastric progenitors in gastric glands in the mouse stomach. We also investigated how the Lrig1-expressing progenitor cells contribute to the regeneration of normal gastric mucosa by lineage commitment to parietal cells after acute gastric injury in mice. DESIGN: We performed lineage labelling using Lrig1-CreERT2/+;R26R-YFP/+ (Lrig1/YFP) or R26R-LacZ/+ (Lrig1/LacZ) mice to examine whether the Lrig1-YFP-marked cells are gastric progenitor cells. We studied whether Lrig1-YFP-marked cells give rise to normal gastric lineage cells in damaged mucosa using Lrig1/YFP mice after treatment with DMP-777 to induce acute injury. We also studied Lrig1-CreERT2/CreERT2 (Lrig1 knockout) mice to examine whether the Lrig1 protein is required for regeneration of gastric corpus mucosa after acute injury. RESULTS: Lrig1-YFP-marked cells give rise to gastric lineage epithelial cells both in the gastric corpus and antrum, in contrast to published results that Lgr5 only marks progenitor cells within the gastric antrum. Lrig1-YFP-marked cells contribute to replacement of damaged gastric oxyntic glands during the recovery phase after acute oxyntic atrophy in the gastric corpus. Lrig1 null mice recovered normally from acute gastric mucosal injury indicating that Lrig1 protein is not required for lineage differentiation. Lrig1+ isthmal progenitor cells did not contribute to transdifferentiating chief cell lineages after acute oxyntic atrophy. CONCLUSIONS: Lrig1 marks gastric corpus epithelial progenitor cells capable of repopulating the damaged oxyntic mucosa by differentiating into normal gastric lineage cells in mouse stomach.

p120-Catenin is an obligate haploinsufficient tumor suppressor in intestinal neoplasia.

p120-Catenin (p120) functions as a tumor suppressor in intestinal cancer, but the mechanism is unclear. Here, using conditional p120 knockout in Apc-sensitized mouse models of intestinal cancer, we have identified p120 as an "obligatory" haploinsufficient tumor suppressor. Whereas monoallelic loss of p120 was associated with a significant increase in tumor multiplicity, loss of both alleles was never observed in tumors from these mice. Moreover, forced ablation of the second allele did not further enhance tumorigenesis, but instead induced synthetic lethality in combination with Apc loss of heterozygosity. In tumor-derived organoid cultures, elimination of both p120 alleles resulted in caspase-3-dependent apoptosis that was blocked by inhibition of Rho kinase (ROCK). With ROCK inhibition, however, p120-ablated organoids exhibited a branching phenotype and a substantial increase in cell proliferation. Access to data from Sleeping Beauty mutagenesis screens afforded an opportunity to directly assess the tumorigenic impact of p120 haploinsufficiency relative to other candidate drivers. Remarkably, p120 ranked third among the 919 drivers identified. Cofactors α-catenin and epithelial cadherin (E-cadherin) were also among the highest scoring candidates, indicating a mechanism at the level of the intact complex that may play an important role at very early stages of of intestinal tumorigenesis while simultaneously restricting outright loss via synthetic lethality.

RETROSPECTIVE REVIEW OF LUCENTIS "TREAT AND EXTEND" PATTERNS AND OUTCOMES IN AGE-RELATED MACULAR DEGENERATION.

PURPOSE: To assess patterns and outcomes of a "Treat and Extend" dosing regimen of ranibizumab in patients with age-related macular degeneration. METHODS: Three hundred and thirty two treatment-naive age-related macular degeneration patients starting therapy with ranibizumab between January 1, 2011, and June 30, 2012, at the Ivey Eye Institute were reviewed, and 79 met inclusion criteria. Patients on Treat and Extend dosing regimen underwent an induction phase with monthly injections and then moved onto an extension phase. Change in visual acuity and central retinal thickness during the induction and extension phases were recorded. RESULTS: During the induction phase, patients had a significant gain in vision and decrease in central retinal thickness (+8.4 letters, P < 0.001 and -81.3 µm, P < 0.001). During the extension phase, patients did not have significant change in vision (-0.5 letters, P = 0.81) and did not have significant change in central retinal thickness (-11.5 µm, P = 0.17). The average extension interval between treatments was 47.7 days, with patients receiving an average of 8.6 injections per year. Cost analysis showed it cost US $16,659 to treat 1 patient in the first year on Treat and Extend dosing regimen compared with US $20,614 on monthly dosing. CONCLUSION: Treat and Extend dosing regimen allows similar visual outcomes to monthly dosing, while reducing the total number of injections, visits, and overall cost.

Generation of induced pluripotent stem cells from domestic goats.

The creation of genetically modified goats provides a powerful approach for improving animal health, enhancing production traits, animal pharming, and for ensuring food safety all of which are high-priority goals for animal agriculture. The availability of goat embryonic stem cells (ESCs) that are characteristically immortal in culture would be of enormous benefit for developing genetically modified animals. As an alternative to long-sought goat ESCs, we generated induced pluripotent stem cells (iPSC) by forced expression of bovine POU5F1, SOX2, MYC, KLF4, LIN-28, and NANOG reprogramming factors in combination with a MIR302/367 cluster, delivered by lentiviral vectors. In order to minimize integrations, the reprogramming factor coding sequences were assembled with porcine teschovirus-1 2A (P2A) self-cleaving peptides that allowed for tri-cistronic expression from each vector. The lentiviral-transduced cells were cultured on irradiated mouse feeder cells in a semi-defined, serum-free medium containing fibroblast growth factor (FGF) and/or leukemia inhibitory factor (LIF). The resulting goat iPSC exhibit cell and colony morphology typical of human and mouse ESCs-that is, well-defined borders, a high nuclear-to-cytoplasmic ratio, a short cell-cycle interval, alkaline phosphatase expression, and the ability to generate teratomas in vivo. Additionally, these goat iPSC demonstrated the ability to differentiate into directed lineages in vitro. These results constitute the first steps in establishing integration and footprint-free iPSC from ruminants. Mol. Reprod. Dev. 82: 709-721, 2015. © 2015 Wiley Periodicals, Inc.

Prospective evaluation of teleophthalmology in screening and recurrence monitoring of neovascular age-related macular degeneration: a randomized clinical trial.

IMPORTANCE: Teleophthalmology has the potential to reduce costs and inconveniences associated with frequent patient visits. Evaluating teleophthalmology in the management of age-related macular degeneration (AMD) will allow for future implementation of this technology. OBJECTIVE: To evaluate teleophthalmology as a tool for the screening and monitoring of neovascular AMD. DESIGN, SETTING, AND PARTICIPANTS: Prospective, randomized clinical trial that included 106 referral eyes for suspected neovascular AMD and 63 eyes with stable neovascular AMD. New referrals for patients with suspected neovascular AMD and patients with stable neovascular AMD were randomized into either routine or teleophthalmologic groups. In the routine group, patients received clinical assessment and diagnostic imaging at a tertiary hospital-based retina clinic. In the teleophthalmologic group, patients received basic examination and diagnostic imaging at a stand-alone teleophthalmologic site, where patient information and imaging studies were acquired and electronically sent over to tertiary hospital-based retina specialists. Patients in the teleophthalmologic group were called back to the tertiary treatment center if the teleophthalmologic data set suggested pathology or was inconclusive for diagnosis. MAIN OUTCOMES AND MEASURES: Patient wait times for diagnosis and/or treatment, referral accuracy, and visual outcome. RESULTS: For neovascular AMD screening, the average referral-to-diagnostic imaging time was 22.5 days for the teleophthalmologic group and 18.0 days for the routine group, for a difference of 4.5 days (95% CI, 11.8 to -2.8 days; P = .23). The average diagnostic imaging to treatment time was 16.4 days for the teleophthalmologic group and 11.6 days for the routine group, for a difference of 4.8 days (95% CI, 10.7 to -1.1 days; P = .11). For neovascular AMD monitoring, the average recurrence to treatment time was shorter for the routine group (0.04 days) compared with 13.6 days for the teleophthalmologic group, for a difference of -13.5 days (95% CI, -18.2 to -9.0 days; P < .01). There was no difference identified between end-of-study visual acuities in the 2 groups (P = .99). CONCLUSIONS AND RELEVANCE: A delay of referral to treatment time could not be identified when comparing teleophthalmologic screening for suspected neovascular AMD with retinal specialist-based screening. Teleophthalmologic monitoring for neovascular AMD recurrence resulted in longer wait times for treatment reinitiation, but no adverse visual outcomes were identified. TRIAL REGISTRATION: clinicaltrials.gov Identifier:NCT01581606.

Using a new Lrig1 reporter mouse to assess differences between two Lrig1 antibodies in the intestine.

Lrig1 is an intestinal stem cell marker important for epithelial homeostasis. However, the position of the Lrig1(+) population in the intestinal crypt has been debated, largely due to discrepant staining patterns using two Lrig1 antibodies. Here, we set out to decipher the differences between these Lrig1 antibodies to clarify their use for Lrig1-related studies. We confirmed that the commercially available Lrig1-R&D antibody stained the bottom third of the colonic crypt, whereas an independently generated Lrig1-VU antibody recognized a subset of anti-Lrig1-R&D(+) cells. Biochemically, we found that anti-Lrig1-VU recognized a non-glycosylated form of Lrig1; in contrast, anti-Lrig1-R&D recognized both glycosylated and non-glycosylated forms of Lrig1. In addition, we generated a reporter mouse (Lrig1-Apple) as an independent readout of Lrig1 transcriptional activity. Flow cytometry of isolated colonic epithelial cells from Lrig1-Apple mice demonstrated anti-Lrig1-R&D recognized mostly RFP-hi cells, while anti-Lrig1-VU recognized cells that were largely RFP-mid. Of note, by qRT-PCR, Lgr5 was expressed in the RFP-hi population, but not in the RFP-mid population. We conclude that anti-Lrig1-R&D appears to recognize all Lrig1(+) cells, while anti-Lrig1-VU recognizes a subpopulation of Lrig1(+) cells.

Disorder and residual helicity alter p53-Mdm2 binding affinity and signaling in cells.

Levels of residual structure in disordered interaction domains determine in vitro binding affinities, but whether they exert similar roles in cells is not known. Here, we show that increasing residual p53 helicity results in stronger Mdm2 binding, altered p53 dynamics, impaired target gene expression and failure to induce cell cycle arrest upon DNA damage. These results establish that residual structure is an important determinant of signaling fidelity in cells.

Intravitreal ranibizumab for the treatment of fibrovascular pigment epithelial detachment in age-related macular degeneration.

OBJECTIVE: To determine the response of predominantly fibrovascular pigment epithelial detachments (PED)-type lesions (secondary to age-related macular degeneration [AMD]) to intravitreal ranibizumab. DESIGN: This was an open-label prospective study. PARTICIPANTS: Thirty-two patients with predominantly fibrovascular PED-type lesions secondary to AMD were included in this study. Three patients were excluded from the final analysis. METHODS: Patients received monthly intravitreal ranibizumab injections for 6 months (induction). At 6 months, patients not experiencing a visual improvement from baseline Early Treatment of Diabetic Retinopathy Study (ETDRS) visual acuity or not showing a reduction in PED height (based on optical coherence tomography [OCT]) were deemed ranibizumab nonresponders and received no further injections but underwent re-evaluation at 12 months. Patients deemed responders continued with OCT-guided active treatment on an as-needed basis for an additional 6 months. RESULTS: Twenty-four patients (82.8%) were ranibizumab responders and 5 were (17.2%) nonresponders. For ranibizumab responders, mean ETDRS visual acuity improved by 7.2 ± 9.8 letters at 6 months (p = 0.002) and 6.3 ± 8.6 letters at 12 months (p = 0.002). Ranibizumab nonresponders experienced a decline in mean visual acuity of 8.2 ± 4.6 letters at 6 months (p = 0.02) and 18.2 ± 10.11 letters at 12 months (p = 0.02). At baseline, responders had a mean PED height of 345.8 ± 96.0 µm, which decreased to 111.6 ± 133.2 µm at 6 months (p < 0.001) and had a slight increase at 12 months to 144.8 ± 146.3 µm (p < 0.001). Two responders (8.3%) and 2 nonresponders (40%) developed retinal pigment epithelium tears while on treatment. CONCLUSIONS: Intravitreal ranibizumab appears to be a well-tolerated treatment option for patients with fibrovascular PED. Further large-scale, prospective studies may assist in delineating the best treatment protocol.

Inducible loss of one Apc allele in Lrig1-expressing progenitor cells results in multiple distal colonic tumors with features of familial adenomatous polyposis.

Individuals with familial adenomatous polyposis (FAP) harbor a germline mutation in adenomatous polyposis coli (APC). The major clinical manifestation is development of multiple colonic tumors at a young age due to stochastic loss of the remaining APC allele. Extracolonic features, including periampullary tumors, gastric abnormalities, and congenital hypertrophy of the retinal pigment epithelium, may occur. The objective of this study was to develop a mouse model that simulates these features of FAP. We combined our Lrig1-CreERT2/+ mice with Apcfl/+ mice, eliminated one copy of Apc in leucine-rich repeats and immunoglobulin-like domains protein 1 (Lrig1)-positive (Lrig1(+)) progenitor cells with tamoxifen injection, and monitored tumor formation in the colon by colonoscopy and PET. Initial loss of one Apc allele in Lrig1(+) cells results in a predictable pattern of preneoplastic changes, culminating in multiple distal colonic tumors within 50 days of induction, as well as the extracolonic manifestations of FAP mentioned above. We show that tumor formation can be monitored by noninvasive PET imaging. This inducible stem cell-driven model recapitulates features of FAP and offers a tractable platform on which therapeutic interventions can be monitored over time by colonoscopy and noninvasive imaging.

Excess PLAC8 promotes an unconventional ERK2-dependent EMT in colon cancer.

The epithelial-to-mesenchymal transition (EMT) transcriptional program is characterized by repression of E-cadherin (CDH1) and induction of N-cadherin (CDH2), and mesenchymal genes like vimentin (VIM). Placenta-specific 8 (PLAC8) has been implicated in colon cancer; however, how PLAC8 contributes to disease is unknown, and endogenous PLAC8 protein has not been studied. We analyzed zebrafish and human tissues and found that endogenous PLAC8 localizes to the apical domain of differentiated intestinal epithelium. Colon cancer cells with elevated PLAC8 levels exhibited EMT features, including increased expression of VIM and zinc finger E-box binding homeobox 1 (ZEB1), aberrant cell motility, and increased invasiveness. In contrast to classical EMT, PLAC8 overexpression reduced cell surface CDH1 and upregulated P-cadherin (CDH3) without affecting CDH2 expression. PLAC8-induced EMT was linked to increased phosphorylated ERK2 (p-ERK2), and ERK2 knockdown restored cell surface CDH1 and suppressed CDH3, VIM, and ZEB1 upregulation. In vitro, PLAC8 directly bound and inactivated the ERK2 phosphatase DUSP6, thereby increasing p-ERK2. In a murine xenograft model, knockdown of endogenous PLAC8 in colon cancer cells resulted in smaller tumors, reduced local invasion, and decreased p-ERK2. Using MultiOmyx, a multiplex immunofluorescence-based methodology, we observed coexpression of cytosolic PLAC8, CDH3, and VIM at the leading edge of a human colorectal tumor, supporting a role for PLAC8 in cancer invasion in vivo.

Efficacy of yttrium-90 synovectomy across a spectrum of arthropathies in an era of improved disease modifying drugs and treatment protocols.

AIM: To evaluate clinical response rates, duration of response and complication rates of yttrium radiosynovectomy (RSV) in an era of improved disease modifying antirheumatic drugs (DMARDS) and increased access to replacement therapy for clotting factor deficiencies introduced in the mid 2000s. METHODS: A retrospective review of 167 consecutive joints treated with RSV between 2000 and 2010 was conducted. Clinical response and complication rates in 167 joints (119 patients: 45 female,74 male, mean age 52 years) with rheumatoid, psoriatic, hemophilic, large joint mono-arthropathy and miscellaneous arthropathies refractory to conventional therapy were reviewed. Clinical response was determined at 3 months with responding patients reviewed again at 36 months to assess whether response was sustained. Comparison of response rates pre- and post-introduction of improved DMARDS in the mid 2000s was also performed. RESULTS: Satisfactory clinical response was highest for large joint mono-arthropathy (85%) and lower for other arthropathies (47-64%). A strong relationship was demonstrated between degree and duration of response with 90% of complete responders compared to 41% of incomplete responders having a sustained response at 36 months (P ≤ 0.0001). Major complication rates were low (1%). No difference was demonstrated in response rates pre- and post-introduction of improved DMARDS in the mid 2000s. CONCLUSION: In an era of improved DMARDS, yttrium synovectomy remains a safe and effective procedure across a broad spectrum of arthropathies and should continue to be considered in cases refractory to conventional therapies. Complete responders can be expected to have symptom relief for at least 36 months and complication rates are low.

Comparison of positron emission tomography/CT and bremsstrahlung imaging following Y-90 radiation synovectomy.

INTRODUCTION: The aim of this study is to compare the results of positron emission tomography (PET)/CT with bremsstrahlung imaging following Y-90 radiation synovectomy. METHODS: All patients referred to our institution for Y-90 radiation synovectomy between July 2011 and February 2012 underwent both PET/CT and bremsstrahlung planar (± single photon emission computed tomography (SPECT) or SPECT/CT) imaging at 4 or 24 h following administration of Y-90 silicate colloid. PET image acquisition was performed for between 15 and 20 min. In patients who underwent SPECT, side-by-side comparison with PET was performed and image quality/resolution scored using a five-point scale. The distribution pattern of Y-90 on PET and bremsstrahlung imaging was compared with the intra- or extra-articular location of Y-90 activity on fused PET/CT. RESULTS: Thirteen joints (11 knees and two ankles) were imaged with both PET/CT and planar bremsstrahlung imaging with 12 joints also imaged with bremsstrahlung SPECT. Of the 12 joints imaged with SPECT, PET image quality/resolution was superior in 11 and inferior in one. PET demonstrated a concordant distribution pattern compared with bremsstrahlung imaging in all scans, with the pattern classified as diffuse in 12 and predominantly focal in one. In all 12 diffuse scans, PET/CT confirmed the Y-90 activity to be located intra-articularly. In the one predominantly focal scan, the fused PET/CT images localised the Y-90 activity to mostly lie in the extra-articular space of the knee. CONCLUSION: PET/CT can provide superior image quality compared with bremsstrahlung imaging and may enable reliable detection of extra-articular Y-90 activity when there are focal patterns on planar bremsstrahlung imaging.

Impact of the K24N mutation on the transactivation domain of p53 and its binding to murine double-minute clone 2.

The level of the p53 transcription factor is negatively regulated by the E3 ubiquitin ligase murine double-minute clone 2 (MDM2). The interaction between p53 and MDM2 is essential for the maintenance of genomic integrity for most eukaryotes. Previous structural studies revealed that MDM2 binds to p53 transactivation domain (p53TAD) from residues 17 to 29. The K24N mutation of p53TAD changes a lysine at position 24 to an asparagine. This mutation occurs naturally in the bovine family and is also found in a rare form of human gestational cancer called choriocarcinoma. In this study, we have investigated how the K24N mutation affects the affinity, structure, and dynamics of p53TAD binding to MDM2. Nuclear magnetic resonance studies of p53TAD show that the K24N mutant is more flexible and has less transient helical secondary structure than the wild type. Isothermal titration calorimetry measurements demonstrate that these changes in structure and dynamics do not significantly change the binding affinity for p53TAD-MDM2. Finally, free-energy perturbation and standard molecular dynamic simulations suggest the negligible affinity change is due to a compensating interaction energy between the K24N mutant and the MDM2 when it is bound. Overall, the data suggest that the K24N-MDM2 complex is able to, at least partly, compensate for an increase in the conformational entropy in unbound K24N with an increase in the bound-state electrostatic interaction energy.

Helicobacter pylori promotes the expression of Krüppel-like factor 5, a mediator of carcinogenesis, in vitro and in vivo.

Helicobacter pylori is the strongest known risk factor for the development of gastric adenocarcinoma. H. pylori expresses a repertoire of virulence factors that increase gastric cancer risk, including the cag pathogenicity island and the vacuolating cytotoxin (VacA). One host element that promotes carcinogenesis within the gastrointestinal tract is Krüppel-like factor 5 (KLF5), a transcription factor that mediates key cellular functions. To define the role of KLF5 within the context of H. pylori-induced inflammation and injury, human gastric epithelial cells were co-cultured with the wild-type cag(+) H. pylori strain 60190. KLF5 expression was significantly upregulated following co-culture with H. pylori, but increased expression was independent of the cag island or VacA. To translate these findings into an in vivo model, C57BL/6 mice were challenged with the wild-type rodent-adapted cag(+) H. pylori strain PMSS1 or a PMSS1 cagE(-) isogenic mutant. Similar to findings in vitro, KLF5 staining was significantly enhanced in gastric epithelium of H. pylori-infected compared to uninfected mice and this was independent of the cag island. Flow cytometry revealed that the majority of KLF5(+) cells also stained positively for the stem cell marker, Lrig1, and KLF5(+)/Lrig1(+) cells were significantly increased in H. pylori-infected versus uninfected tissue. To extend these results into the natural niche of this pathogen, levels of KLF5 expression were assessed in human gastric biopsies isolated from patients with or without premalignant lesions. Levels of KLF5 expression increased in parallel with advancing stages of neoplastic progression, being significantly elevated in gastritis, intestinal metaplasia, and dysplasia compared to normal gastric tissue. These results indicate that H. pylori induces expression of KLF5 in gastric epithelial cells in vitro and in vivo, and that the degree of KLF5 expression parallels the severity of premalignant lesions in human gastric carcinogenesis.

Pathology of rodent models of intestinal cancer: progress report and recommendations.

In October 2010, a pathology review of rodent models of intestinal neoplasia was held at The Jackson Laboratory. This review complemented 2 other concurrent events: a workshop on methods of modeling colon cancer in rodents and a conference on current issues in murine and human colon cancer. We summarize the results of the pathology review and the committee's recommendations for tumor nomenclature. A virtual high-resolution image slide box of these models has been developed. This report discusses significant recent developments in rodent modeling of intestinal neoplasia, including the role of stem cells in cancer and the creation of models of metastatic intestinal cancer.

Comparison of outcomes after switching treatment from intravitreal bevacizumab to ranibizumab in neovascular age-related macular degeneration.

OBJECTIVE: To compare visual acuity and central retinal thickness in patients initially treated with bevacizumab (Avastin) and switched to ranibizumab (Lucentis) for neovascular age-related macular degeneration (AMD). DESIGN: A retrospective chart review. PARTICIPANTS: This study included 87 eyes from 80 patients over the age of 65 with neovascular AMD. METHODS: Patients were initially treated with bevacizumab injections every 6 weeks and then switched to ranibizumab every 4 weeks when it became publicly funded by the Ontario government. Outcomes include comparison of visual acuity and central retinal thickness after bevacizumab treatment, and after switching to ranibizumab. RESULTS: Visual acuity improved significantly versus initial baseline values following a treatment course of 3 or more injections of bevacizumab (0.58 logMar, SD = 0.30 vs 0.73 logMar, SD = 0.41; p = 0.0007). Patients then showed a further significant improvement in visual acuity after switching and receiving a course of ranibizumab (0.51 logMar, SD = 0.32) (p = 0.0122). Mean central retinal thickness as measured by optical coherence tomography significantly decreased after a course of bevacizumab (p = 0.0158), and a further decrease was noted after a subsequent course of ranibizumab (p < 0.0001). CONCLUSIONS: There was a significant improvement in visual acuity and central retinal thickness in patients with neovascular AMD initially treated with bevacizumab. When these patients were uniformly switched to ranibizumab there was a further significant improvement in visual acuity and a reduction of retinal thickness. It appears that ranibizumab can maintain, or improve the effect achieved after an initial course of bevacizumab.