Recovery Animals in Toxicology Studies: An Innovation and Quality Consortium Perspective on Best Practices With Case Study Examples.

The inclusion of recovery animals in nonclinical safety studies that support clinical trials is undertaken with a wide diversity of approaches even while operating under harmonized regulatory guidance. While empirical evaluation of reversibility may enhance the overall nonclinical risk assessment, there are often overlooked opportunities to reduce recovery animal use by leveraging robust scientific and regulatory information. In the past, there were several attempts to benchmark recovery practices; however, recommendations have not been consistently applied across the pharmaceutical industry. A working group (WG) sponsored by the 3Rs Translational and Predictive Sciences Leadership Group of the IQ Consortium conducted a survey of current industry practice related to the evaluation of reversibility/recovery in repeat dose toxicity studies. Discussion among the WG representatives included member company strategies and case studies that highlight challenges and opportunities for continuous refinements in the use of recovery animals. The case studies presented in this paper demonstrate increasing alignment with the Society of Toxicologic Pathology recommendations (2013) towards (1) excluding recovery phase cohorts by default (include only when scientifically justified), (2) minimizing the number of recovery groups (e.g., control and one dose level), and (3) excluding controls in the recovery cohort by leveraging external and/or dosing phase data. Recovery group exclusion and decisions regarding the timing of reversibility evaluation may be driven by indication, modality, and/or other scientific or strategic factors using a weight of evidence approach. The results and recommendations discussed present opportunities to further decrease animal use without impacting the quality of human risk assessment.

Mode of action and human relevance assessment of male CD-1 mouse renal adenocarcinoma associated with lifetime exposure to empagliflozin.

Inhibition of sodium-glucose cotransporter-2 (SGLT2) has been shown to be a safe and efficacious approach to support managing Type 2 diabetes. In the 2-year carcinogenicity study with the SGLT2 inhibitor empagliflozin in CD-1 mice, an increased incidence of renal tubular adenomas and carcinomas was identified in the male high-dose group but was not observed in female mice. An integrated review of available nonclinical data was conducted to establish a mode-of-action hypothesis for male mouse-specific tumorigenesis. Five key events were identified through systematic analysis to form the proposed mode-of-action: (1) Background kidney pathology in CD-1 mice sensitizes the strain to (2) pharmacology-related diuretic effects associated with SGLT2 inhib ition. (3) In male mice, metabolic demand increases with the formation of a sex- and species-specific empagliflozin metabolite. These features converge to (4) deplete oxidative stress handling reserve, driving (5) constitutive cellular proliferation in male CD-1 mice. The proposed mode of action requires all five key events for empagliflozin to present a carcinogenicity risk in the CD-1 mouse. Considering that empagliflozin is not genotoxic in the standard battery of genotoxicity tests, and not all five key events are present in the context of female mice, rats, or humans, nor for other osmotic diuretics or other SGLT2 inhibitors, the observed male mouse renal tumors are not considered relevant to humans.

Michelle's Story: The Complexity of Patient Care in a Family Medicine Residency Clinic.

Family medicine covers all ages and specializes in chronic disease management as well as acute care medicine. As the health of the population continues to grow in complexity, treating patients appropriately and efficiently is imperative to improving health outcomes and managing health care costs. Family medicine physicians are uniquely poised to provide this type of care. A patient story plus a look at the patients seen over the course of a day within a family medicine residency clinic explores the complexity of care and the ability of family medicine physicians to provide the necessary care. Taking a close look at who comes through our door on a particular day highlights 3 points: primary care physicians are seeing patients with an increasing complexity of needs, our society is witnessing an extreme increase in patients suffering with mental health problems and substance use disorders, and addressing social determinants of health must be part of the solution.

The use of emerging safety biomarkers in nonclinical and clinical safety assessment - The current and future state: An IQ DruSafe industry survey.

Pharmaceutical and biotechnology companies rarely disclose their use of translational emerging safety biomarkers (ESBs) during drug development, and the impact of ESB use on the speed of drug development remains unclear. A cross-industry survey of 20 companies of varying size was conducted to understand current trends in ESB use and future use prospects. The objectives were to: (1) determine current ESB use in nonclinical and clinical drug development and impact on asset advancement; (2) identify opportunities, gaps, and challenges to greater ESB implementation; and (3) benchmark perspectives on regulatory acceptance. Although ESBs were employed in only 5-50% of studies/programs, most companies used ESBs to some extent, with larger companies demonstrating greater nonclinical use. Inclusion of ESBs in investigational new drug applications (INDs) was similar across all companies; however, differences in clinical trial usage could vary among the prevailing health authority (HA). Broader implementation of ESBs requires resource support, cross-industry partnerships, and collaboration with HAs. This includes generating sufficient foundational data, demonstrating nonclinical to clinical translatability and practical utility, and clearly written criteria by HAs to enable qualification. If achieved, ESBs will play a critical role in the development of next-generation, translationally-tailored standard laboratory tests for drug development.

Identification of sperm mRNA biomarkers associated with testis injury during preclinical testing of pharmaceutical compounds.

The human testis is sensitive to toxicant-induced injury but current methods for detecting adverse effects are limited, insensitive and unreliable. Animal studies use sensitive histopathological endpoints to assess toxicity, but require testicular tissue that is not available during human clinical trials. More sensitive and reliable molecular biomarkers of testicular injury are needed to better monitor testicular toxicity in both clinical and preclinical. Adult male Wistar Han rats were exposed for 4weeks to compounds previously associated with testicular injury, including cisplatin (0, 0.2, 0.3, or 0.4mg/kg/day), BI665915 (0, 20, 70, 100mg/kg/d), BI665636 (0, 20, 100mg/kg/d) or BI163538 (0, 70, 150, 300mg/kg/d) to evaluate reproductive toxicity and assess changes in sperm mRNA levels. None of the compounds resulted in any significant changes in body, testis or epididymis weights, nor were there decreases in testicular homogenization resistant spermatid head counts. Histopathological evaluation found that only BI665915 treatment caused any testicular effects, including minor germ cell loss and disorganization of the seminiferous tubule epithelium, and an increase in the number of retained spermatid heads. A custom PCR-array panel was used to assess induced changes in sperm mRNA. BI665915 treatment resulted in a significant increase in clusterin (Clu) levels and decreases in GTPase, IMAP family member 4 (Gimap4), prostaglandin D2 synthase (Ptgds) and transmembrane protein with EGF like and two follistatin like domains 1 (Tmeff1) levels. Correlation analysis between transcript levels and quantitative histopathological endpoints found a modest association between Clu with retained spermatid heads. These results demonstrate that sperm mRNA levels are sensitive molecular indicators of testicular injury that can potentially be translated into a clinical setting.

A Predominant Oxidative Renal Metabolite of Empagliflozin in Male Mice Is Cytotoxic in Mouse Renal Tubular Cells but not Genotoxic.

In a previously reported CD-1 mouse 2-year carcinogenicity study with the sodium glucose cotransporter-2 inhibitor empagliflozin, an increased incidence of renal tubular adenomas and carcinomas was identified only in the male high-dose group. Follow-up investigative studies have shown that the renal tumors in male high-dose mice were preceded by a number of renal degenerative/regenerative findings. Prior cross-species in vitro metabolism studies using microsomes identified an oxidative metabolite (M466/2) predominantly formed in the male mouse kidney and which spontaneously degrades to a metabolite (M380/1) and reactive 4-OH crotonaldehyde (CTA). In order to further evaluate potential modes of action for empagliflozin-associated male mouse renal tumors, we report here a series of in vitro investigative toxicology studies conducted to evaluate the cytotoxic and genotoxic potential of empagliflozin and M466/2. To assess the cytotoxic potential of empagliflozin and M466/2, a primary mouse renal tubular epithelial (mRTE) cell model was used. In mRTE cells, M466/2-derived in vitro 4-OH CTA exposure was cytotoxic, while empagliflozin was not cytotoxic or mitogenic. Empagliflozin and M466/2 were not genotoxic, supporting an indirect mode of action for empagliflozin-associated male mouse renal tumorigenesis. In conclusion, these in vitro data show that M466/2-derived 4-OH CTA exposure is associated with cytotoxicity in renal tubule cells and may be involved in promoting compound-related in vivo renal metabolic stress and chronic low-level renal injury, in turn supporting a nongenotoxic mode of tumor pathogenesis specific to the male mouse.

Young patients with synchronous colorectal liver metastases.

BACKGROUND: An increasing proportion of patients are presenting with colorectal cancer at an early age. A proportion of these occur with genetic syndromes; however the majority present as sporadic. The purpose of this study is to investigate the prognosis and treatment of young patients with sporadic metastatic colorectal cancer. METHODS: Following IRB approval, patients with sporadic metastatic colorectal cancer at 40 years or under were identified. Patient charts and pathology reports were analyzed retrospectively for clinical and pathological factors. RESULTS: Three hundred and two patients were identified; 148 with liver metastases only, and 154 with extra-hepatic disease. Five-year overall survival was 19%, 28% for liver only disease, and 12% for extrahepatic disease. For patients with liver metastases only, factors associated with survival on univariable analysis included diagnosis in the 2000's, unilobular hepatic disease, smaller volume liver metastases, intrahepatic pump chemotherapy, resection of the primary, and resection of liver metastases. On multivariable analysis factors associated with survival included resection of the primary, resection of liver metastases, and diagnosis in the 2000's. CONCLUSION: Sporadic metastatic colorectal cancer in young patients appears to have a similar prognosis to that in older patients. The most significant prognostic factor was the ability to resect all sites of disease. J. Surg. Oncol. 2016;113:473-476. © 2016 Wiley Periodicals, Inc.

Lymph Node Metastasis Predicts Disease Recurrence in a Single-Center Experience of 70 Stages 1-3 Appendix Cancers: A Retrospective Review.

BACKGROUND: Previous reports on the surgical management of appendix cancer show high recurrence rates among patients initially presenting with localized disease. This study sought to characterize predictors of outcome among patients treated for stages 1-3 appendix cancer at the authors' institution. METHODS: Patients with nonmetastatic appendix cancer undergoing definitive surgery at a single cancer center from 1994 to 2013 were retrospectively reviewed. Patients with appendiceal adenomas, cystadenomas, or classical carcinoids were excluded from the study. The median follow-up period was 5.2 years (interquartile range 2.9-6.7 years). RESULTS: The study identified 70 patients, 49 % of whom were women. The median age was 52 years (range 20-84 years). All were explored by an expert surgeon who had treated at least 20 appendiceal cancers. The procedures were appendectomy (n = 2), right hemicolectomy (n = 66), and diagnostic laparoscopy and placement of an intraperitoneal port (n = 2). The final pathology showed that transmural (30 T4, 32 T3, 4 T2, 4 T1) and node-negative disease (80 %) were common. Goblet cell carcinoid (GCC) features were identified in 54 % of the tumors. These were smaller and more likely to present as acute appendicitis than appendiceal adenocarcinoma (AA), but were otherwise similar in clinical presentation and outcome. The presence of lymph node (LN) metastasis was associated with a higher risk of recurrence than of stage 2 appendix cancer (78 vs. 4 % at 5 years; p < 0.0001). A total of 12 patients experienced recurrence (5 GCC, 7 AA): 9 in the peritoneum, 2 in mesenteric LNs, and 1 in the surgical incision. CONCLUSION: Stages 1-3 invasive AA and GCC behave similarly in terms of clinical presentation and outcome. Perforated appendix and T4 tumor stage were common but not associated with recurrence. Although uncommon, LN metastasis strongly predicted recurrence.

An investigation into the clinical impacts of lowering shunt opening pressure in idiopathic normal pressure hydrocephalus: A case series.

INTRODUCTION: Idiopathic normal pressure hydrocephalus (iNPH) is a shunt- reversible syndrome of the elderly. Shunt management is aimed at achieving a balance between clinical improvement and the complications associated with overdrainage. Although clinical improvement occurs at low pressure, these benefits may be negated by the increase in complication rates observed at lower pressures. The addition of gravity-switch devices has been shown to reduce over drainage problems even at a low valve pressure setting. At our centre the Miethke proGAV is used and commonly lowered below 5 cmH2O to gain further clinical improvement. OBJECT: To determine whether lowering the opening pressure to below 5cmH2O using the proGAV valve in iNPH patients results in a) improved clinical features; and b) no significant increase in complication rates. METHODS: A retrospective case series of iNPH patients was undertaken with 24 patients who had the proGAV shunt system inserted with an initial opening pressure of 5cmH2O. Exclusion criteria were secondary NPH, shunt system other than proGAV inserted, no valve adjustment to below 5cmH2O and inadequate follow-up. Outcome measures were clinical improvement (gait, cognition and urinary continence) and complications (subdural haematoma, low-pressure symptoms and valve damage). RESULTS: Patients underwent a total of 29 adjustments to below 5cmH2O. The mean valve opening pressure after the first adjustment was 2.5cmH2O and the mean opening pressure after the second adjustment was 1cmH2O. Overall, outcome after adjustment included 26% no change, 48% improvement and 26% deterioration clinically. One patient (4%) suffered traumatic subdural haematoma that resolved with increasing valve pressure to 20cmH2O. There was no valve damage or low-pressure symptoms after adjustment. CONCLUSION: This study found that lowering the opening pressure of the proGAV shunt system to below 5cmH2O results in clinical improvement and does not significantly increase the complication rate in iNPH patients.

A retrospective review of 126 high-grade neuroendocrine carcinomas of the colon and rectum.

BACKGROUND: High-grade neuroendocrine carcinomas (HGNECs) of the colon and rectum are rare, constituting less than 1 % of colorectal cancers. The purpose of this study was to identify the natural history and oncologic outcomes of this disease, describe the use of surgery, and determine the clinical and pathological factors associated with outcomes. METHODS: Following Institutional Review Board approval, patients with HGNEC were identified from our institutional database. Patient charts and pathology reports were analyzed retrospectively for clinical and pathological factors. RESULTS: A total of 126 patients with a median follow-up of 9 months were identified. Median survival was 13.2 months, and 85 (67 %) patients had metastatic disease at diagnosis. Three-year overall survival (OS) was 5 and 18 % for patients with and without metastatic disease, respectively. Factors associated with improved OS on multivariable analysis were absence of metastatic disease and presence of an adenocarcinoma component within the tumor. In patients with metastatic disease, response to chemotherapy was the only factor associated with survival. In patients with localized disease, an adenocarcinoma component within the tumor was the only factor associated with survival. Resection of tumor was not associated with survival in either localized or metastatic disease. CONCLUSION: High-grade colorectal NECs are extremely aggressive tumors with poor prognosis. Patients appear to have a marginally better prognosis if they present without metastatic disease, have an adenocarcinoma component within their tumor, or respond to chemotherapy. Surgery, particularly in the presence of metastatic disease, may not offer a survival benefit for the majority of patients.

Anastomotic leak following low anterior resection in stage IV rectal cancer is associated with poor survival.

BACKGROUND: Anastomotic leak is a serious complication of low anterior resection (LAR). The risk of leak in stage IV rectal cancer patients treated with synchronous or staged resection of the primary tumour and metastatic sites has not been reported. We measured the incidence of anastomotic leak and its association with clinical outcome. METHODS: With institutional review board approval, patients undergoing LAR and resection of metastatic disease were analyzed from a prospectively collected colorectal database between 1992 and 2010. Data for use of ileostomy, clinical anastomotic leak, and clinical risk score (for liver metastases, n = 86) were collected. Categorical variables were compared with the χ(2) test. Estimated overall survival was compared using log-rank method and Cox regression analysis. RESULTS: A total of 184 patients with LAR and stage IV disease were identified. Of those, 123 had curative resection for disease at distant sites. 72 % underwent simultaneous resection, 28 % staged resection. Median follow-up was 2.9 years for survivors. Anastomotic leak occurred in 6.5 %. There was one perioperative death (not attributable to leak). Overall 3-year survival following a leak was significantly worse compared with patients without a leak (35 vs. 73 %, P = 0.01). Clinical leak was associated with worse survival when controlled for use of diverting stoma, operative year, clinical risk score, and timing of resection of metastatic disease. CONCLUSIONS: In this series of patients with stage IV rectal cancer, anastomotic leak was uncommon. However, patients who developed a clinical leak following surgery had worse survival. This finding was independent of use of diverting stoma or staged resection.

Anastomotic leak is not associated with oncologic outcome in patients undergoing low anterior resection for rectal cancer.

OBJECTIVE: To examine the association between anastomotic leak and oncologic outcome after anterior resection, stratifying for defunctioning stoma. BACKGROUND: It has been hypothesized that anastomotic leak predisposes rectal cancer patients to local recurrence. Many have a defunctioning stoma to reduce risk of clinically significant leakage. METHODS: The records of patients undergoing low anterior resection (1991-2010) for rectal adenocarcinoma (≤15 cm from anal verge) were retrospectively analyzed using a prospectively collected colorectal database. Data (age, gender, stage, defunctioning stoma, neoadjuvant treatment, distance from anal verge, anastomotic leak) were collected. Clinical leakage was defined as anastomotic complication requiring intervention or interventional radiology within 60 days of surgery. Estimated local recurrence, overall survival, and disease-specific survival were compared using log-rank method and Cox regression analysis. RESULTS: 1127 patients were included, with 5.6-year median follow-up. The incidence of clinical anastomotic leak was 3.5%. Sixteen of 677 with defunctioning stoma (2.2%) developed clinical leak; 24 of 450 without stoma (6.3%) developed leak (P = 0.005). There were no perioperative deaths among patients with clinical leakage. When stratified for defunctioning stoma, there was no association between clinical leak and local recurrence, disease-free survival, or overall survival. On multivariable analysis, when controlling for neoadjuvant therapy, distance of tumor from anal verge, defunctioning stoma, and pathologic stage, clinical leak was not associated with time to local recurrence, disease-free survival, or overall survival. CONCLUSIONS: In this cohort, anastomotic leakage was not associated with risk of local recurrence. Defunctioning stoma was associated with lower incidence of clinical leakage but not with difference in oncologic outcome. Careful patient selection for defunctioning stoma helps reduce risk of clinically significant anastomotic leak.

Nonoperative management of rectal cancer with complete clinical response after neoadjuvant therapy.

INTRODUCTION: Nonoperative management (NOM) of rectal cancer after a complete clinical response (cCR) to neoadjuvant therapy is controversial. In this article, we retrospectively reviewed the outcomes of patients managed with selective NOM after a cCR to neoadjuvant treatment and compared these with patients who underwent standard rectal resection with a pathological complete response (pCR). METHODS: Patients completing neoadjuvant chemoradiotherapy (CRT) for stage I to III rectal cancer between January 2006 and August 2010 were retrospectively reviewed. Median follow-up was calculated in months after completion of CRT. RESULTS: Thirty-two patients (median follow-up 28 months) were treated by NOM after a cCR. Among 265 treated by CRT and rectal resection, 57 patients (22%) had a pCR and formed the control group (median follow-up 43 months). Factors associated with selective use of NOM included lower pretreatment stage, older age, and distal tumor location (P < 0.05). In the NOM group, 6 recurred locally (median 11 months, range 7-14), 3 of whom also had concurrent distant recurrence. All 6 local failures were controlled by salvage rectal resection with no further local recurrence of disease (median follow-up 17 months). In the rectal resection/pCR group, there were no local failures. The 2-year distant disease-free survival (88% vs 98%, P = 0.27) and overall survival (96% vs 100%, P = 0.56) were similar for NOM and rectal resection/pCR groups. CONCLUSIONS: Rectal resection was successfully avoided in 81% of patients selected for NOM. When combined with salvage surgery, NOM appears to achieve similar local and distant disease control compared with patients with a pCR treated by rectal resection. Longer follow-up and prospective trials are warranted to evaluate this promising treatment option.

Mitigation of off-target adrenergic binding and effects on cardiovascular function in the discovery of novel ribosomal S6 kinase 2 inhibitors.

We previously reported the discovery of a novel ribosomal S6 kinase 2 (RSK2) inhibitor, (R)-5-Methyl-1-oxo-2,3,4,5-tetrahydro-1H-[1,4]diazepino[1,2-a] indole-8-carboxylic acid [1-(3-dimethylamino-propyl)-1H-benzoimidazol-2-yl]-amide (BIX 02565), with high potency (IC(50) = 1.1 nM) targeted for the treatment of heart failure. In the present study, we report that despite nanomolar potency at the target, BIX 02565 elicits off-target binding at multiple adrenergic receptor subtypes that are important in the control of vascular tone and cardiac function. To elucidate in vivo the functional consequence of receptor binding, we characterized the cardiovascular (CV) profile of the compound in an anesthetized rat CV screen and telemetry-instrumented conscious rats. Infusion of BIX 02565 (1, 3, and 10 mg/kg) in the rat CV screen resulted in a precipitous decrease in both mean arterial pressure (MAP; to -65 ± 6 mm Hg below baseline) and heart rate (-93 ± 13 beats/min). In telemetry-instrumented rats, BIX 02565 (30, 100, and 300 mg/kg p.o. QD for 4 days) elicited concentration-dependent decreases in MAP after each dose (to -39 ± 4 mm Hg on day 4 at T(max)); analysis by Demming regression demonstrated strong correlation independent of route of administration and influence of anesthesia. Because of pronounced off-target effects of BIX 02565 on cardiovascular function, a high-throughput selectivity screen at adrenergic α(1A) and α(2A) was performed for 30 additional RSK2 inhibitors in a novel chemical series; a wide range of adrenergic binding was achieved (0-92% inhibition), allowing for differentiation within the series. Eleven lead compounds with differential binding were advanced to the rat CV screen for in vivo profiling. This led to the identification of potent RSK2 inhibitors (cellular IC(50) <0.14 nM) without relevant α(1A) and α(2A) inhibition and no adverse cardiovascular effects in vivo.

Alpha T-catenin (CTNNA3): a gene in the hand is worth two in the nest.

Alpha-T-Catenin (CTNNA3) is a key protein of the adherens junctional complex in epithelial cells playing a crucial role in cellular adherence. What makes this gene particularly interesting is that it is located within a common fragile site, is epigenetically regulated, is transcribed through multiple promoters, and generates a variety of alternate transcripts. Finally, CTNNA3 has a nested gene (LRTMM3) embedded within its genomic context transcribed in the opposite direction. Apart from the complexity of its regulation, alterations in both CTNNA3 and LRTMM3 are implicated in human disease.

Secondary normal pressure hydrocephalus in a patient with isolated frontal dilatation--an insight into pathophysiology?

Current theories of the pathophysiology of normal pressure hydrocephalus suggest the classical symptoms are a consequence of disruption of normal frontal function. We present the case of a 70-year-old patient with an isolated, frontal dilatation of his lateral ventricles in the presence of a complete triad as supportive of these theories.

Do helmets worn for hurling fail to protect the ear? Identification of an emerging injury pattern.

Hurling is an Irish national game of stick and ball known for its ferocity, played by 190 000 players. Facial injuries were common but have been significantly reduced by legislation enforcing compulsory helmet wearing. Current standard helmets worn by hurlers do not offer protection to the external ear. Here we describe an emerging pattern of ear injuries and demonstrate the risk of external ear injuries in hurlers complying with current helmet safety standards. A 6-month retrospective analysis was carried out of patients attending Cork University Hospital (CUH) with ear lacerations sustained while hurling. Patient notes were reviewed and helmet manufacturers were interviewed. Seven patients were identified, all of whom sustained complex through ear lacerations while wearing helmets complying with current safety standards. Current helmet design fails to protect the external ear placing it at an increased risk of injury, a potential solution is to include ear protection in the helmet design.

Anisotropic Particle Fabrication Using Thermal Scanning Probe Lithography.

Size, shape, and chemical properties of nanoparticles are powerful tools to modulate the optical and physicochemical properties of a particle suspension. Despite having many methods to synthesize anisotropic nanoparticles, often there are challenges in terms of controlling the polydispersity, shape, size, or composition of anisotropic nanoparticles. This work has been inspired by the potential for developing a unique pathway to make different shaped monodispersed anisotropic nano- and microparticles with large flexibility in material choice. Compared to existing methods, this state-of-the-art nanolithographic method is fast, easy to prototype, and much simple in terms of its mechanical requirement. We show that this technique has been efficiently used to make a variety of anisotropic nano- and microparticles of different shapes, such as triangular prisms, ovals, disks, flowers, and stairs following the same pathway, at the same time showing the potential of being flexible with respect to the composition of the particles. The thermal scanning probe lithographic method in combination with dry reactive ion etching was used to make two-dimensional and three-dimensional templates for the fabrication of anisotropic nano- and microparticles. Deposition of different metal/metal oxides by the electron-beam evaporation method onto these templates allowed us to fabricate a range of nanomaterials according to the required functionality in potential applications. The particles were characterized by atomic force microscopy, He-ion microscopy, scanning electron microscopy, and dynamic light scattering to ensure that the developed method is reproducible, flexible, and robust in choosing the shapes for making monodispersed anisotropic nanoparticles with great control over shape and size.

A ferrocene-containing nucleoside analogue targets DNA replication in pancreatic cancer cells.

Pancreatic ductal adenocarcinoma (PDAC) is a disease that remains refractory to existing treatments including the nucleoside analogue gemcitabine. In the current study we demonstrate that an organometallic nucleoside analogue, the ferronucleoside 1-(S,Rp), is cytotoxic in a panel of PDAC cell lines including gemcitabine-resistant MIAPaCa2, with IC50 values comparable to cisplatin. Biochemical studies show that the mechanism of action is inhibition of DNA replication, S-phase cell cycle arrest and stalling of DNA-replication forks, which were directly observed at single molecule resolution by DNA-fibre fluorography. In agreement with this, transcriptional changes following treatment with 1-(S,Rp) include activation of three of the four genes (HUS1, RAD1, RAD17) of the 9-1-1 check point complex clamp and two of the three genes (MRE11, NBN) that form the MRN complex as well as activation of multiple downstream targets. Furthermore, there was evidence of phosphorylation of checkpoint kinases 1 and 2 as well as RPA1 and gamma H2AX, all of which are considered biochemical markers of replication stress. Studies in p53-deficient cell lines showed activation of CDKN1A (p21) and GADD45A by 1-(S,Rp) was at least partially independent of p53. In conclusion, because of its potency and activity in gemcitabine-resistant cells, 1-(S,Rp) is a promising candidate molecule for development of new treatments for PDAC.

Design of a Novel Online, Modular, Flipped-classroom Surgical Curriculum for East, Central, and Southern Africa.

Objective: We describe a structured approach to developing a standardized curriculum for surgical trainees in East, Central, and Southern Africa (ECSA). Summary Background Data: Surgical education is essential to closing the surgical access gap in ECSA. Given its importance for surgical education, the development of a standardized curriculum was deemed necessary. Methods: We utilized Kern's 6-step approach to curriculum development to design an online, modular, flipped-classroom surgical curriculum. Steps included global and targeted needs assessments, determination of goals and objectives, the establishment of educational strategies, implementation, and evaluation. Results: Global needs assessment identified the development of a standardized curriculum as an essential next step in the growth of surgical education programs in ECSA. Targeted needs assessment of stakeholders found medical knowledge challenges, regulatory requirements, language variance, content gaps, expense and availability of resources, faculty numbers, and content delivery method to be factors to inform curriculum design. Goals emerged to increase uniformity and consistency in training, create contextually relevant material, incorporate best educational practices, reduce faculty burden, and ease content delivery and updates. Educational strategies centered on developing an online, flipped-classroom, modular curriculum emphasizing textual simplicity, multimedia components, and incorporation of active learning strategies. The implementation process involved establishing thematic topics and subtopics, the content of which was authored by regional surgeon educators and edited by content experts. Evaluation was performed by recording participation, soliciting user feedback, and evaluating scores on a certification examination. Conclusions: We present the systematic design of a large-scale, context-relevant, data-driven surgical curriculum for the ECSA region.