Timing of standard chow exposure determines the variability of mouse phenotypic outcomes and gut microbiota profile

Standard chow diet contributes to reproducibility in animal model experiments since chows differ in nutrient composition, which can independently influence phenotypes. However, there is little evidence of the role of timing in the extent of variability caused by chow exposure. Here, we measured the impact of diet (5V5M, 5V0G, 2920X, and 5058) and timing of exposure (adult exposure (AE), lifetime exposure (LE), and developmental exposure (DE)) on growth & development, metabolic health indicators, and gut bacterial microbiota profiles across genetically identical C57BL6/J mice. Diet drove differences in macro- and micronutrient intake for all exposure models. AE had no effect on measured outcomes. However, LE mice exhibited significant sex-dependent diet effects on growth, body weight, and body composition. LE effects were mostly absent in the DE model, where mice were exposed to chow differences from conception to weaning. Both AE and LE models exhibited similar diet-driven beta diversity profiles for the gut bacterial microbiota, with 5058 diet driving the most distinct profile. Diet-induced beta diversity profiles were sex-dependent for LE mice. Compared to AE, LE drove 9X more diet-driven differentially abundant genera, majority of which were the result of inverse effects of 2920X and 5058. Our findings demonstrate that lifetime exposure to different chow diets has the greatest impact on reproducibility of experimental measures that are common components of preclinical mouse model studies. Importantly, weaning DE mice onto a uniform diet is likely an effective way to reduce unwanted phenotypic variability among experimental models.

The Mutant Mouse Resource and Research Center (MMRRC): the NIH-supported National Public Repository and Distribution Archive of Mutant Mouse Models in the USA

The Mutant Mouse Resource and Research Center (MMRRC) Program is the pre-eminent public national mutant mouse repository and distribution archive in the USA, serving as a national resource of mutant mice available to the global scientific community for biomedical research. Established more than two decades ago with grants from the National Institutes of Health (NIH), the MMRRC Program supports a Consortium of regionally distributed and dedicated vivaria, laboratories, and offices (Centers) and an Informatics Coordination and Service Center (ICSC) at three academic teaching and research universities and one non-profit genetic research institution. The MMRRC Program accepts the submission of unique, scientifically rigorous, and experimentally valuable genetically altered and other mouse models donated by academic and commercial scientists and organizations for deposition, maintenance, preservation, and dissemination to scientists upon request. The four Centers maintain an archive of nearly 60,000 mutant alleles as live mice, frozen germplasm, and/or embryonic stem (ES) cells. Since its inception, the Centers have fulfilled 13,184 orders for mutant mouse models from 9591 scientists at 6626 institutions around the globe. Centers also provide numerous services that facilitate using mutant mouse models obtained from the MMRRC, including genetic assays, microbiome analysis, analytical phenotyping and pathology, cryorecovery, mouse husbandry, infectious disease surveillance and diagnosis, and disease modeling. The ICSC coordinates activities between the Centers, manages the website (mmrrc.org) and online catalog, and conducts communication, outreach, and education to the research community. Centers preserve, secure, and protect mutant mouse lines in perpetuity, promote rigor and reproducibility in scientific experiments using mice, provide experiential training and consultation in the responsible use of mice in research, and pursue cutting edge technologies to advance biomedical studies using mice to improve human health. Researchers benefit from an expansive list of well-defined mouse models of disease that meet the highest standards of rigor and reproducibility, while donating investigators benefit by having their mouse lines preserved, protected, and distributed in compliance with NIH policies.

Surgical management of superficial digital flexor tendon luxation in dogs: 48 cases (2005-2020)

OBJECTIVES

To report the outcome, frequency of complications and potential prognostic factors associated with surgical repair of superficial digital flexor tendon (SDFT) luxation in dogs.

MATERIALS AND METHODS

Medical records from 10 referral hospitals were reviewed retrospectively for cases of SDFT luxation in dogs that underwent surgical stabilisation. Signalment, clinical presentation, diagnostic imaging, surgical method, type and length of post-operative limb immobilisation, nature of and length of exercise restriction, presence of post-operative complications and outcomes were recorded. Data were summarised descriptively and prognostic risk factors assessed for association with surgical outcome using risk ratios.

RESULTS

Forty-eight cases were included. A successful surgical outcome was recorded in 35 of 48 (73%) cases. Re-luxation of the SDFT occurred in seven of 48 (15%). Six out of 48 (13%) had a persistent lameness despite a stable non-luxating SDFT. A high frequency of post-operative complications occurred (71%), with the majority resolved medically. The risk of surgical failure was 60% higher (risk ratio 1.6, 95% confidence interval 1.1 to 2.4) where absorbable suture material was used compared to non-absorbable suture material. Surgical failure was more common in cases managed with non-rigid immobilisation post-operatively (57% failure) compared to cases managed with rigid immobilisation (19% failure), although this result was not statistically significant. Limb immobilisation of 6 weeks or longer did not significantly affect surgical outcome, compared to shorter periods of exercise restriction or limb immobilisation.

CLINICAL SIGNIFICANCE

A good outcome can be expected following surgical stabilisation of SDFT luxation. The use of non-absorbable suture was associated with a more successful surgical outcome.

Self-Assembled Materials Incorporating Functional Porphyrins and Carbon Nanoplatforms as Building Blocks for Photovoltaic Energy Applications

As a primary goal, this review highlights the role of supramolecular interactions in the assembly of new sustainable materials incorporating functional porphyrins and carbon nanoplatforms as building blocks for photovoltaics advancements.

Content and Performance of the MiniMUGA Genotyping Array: A New Tool To Improve Rigor and Reproducibility in Mouse Research

The laboratory mouse is the most widely used animal model for biomedical research, due in part to its well-annotated genome, wealth of genetic resources, and the ability to precisely manipulate its genome. Despite the importance of genetics for mouse research, genetic quality control (QC) is not standardized, in part due to the lack of cost-effective, informative, and robust platforms. Genotyping arrays are standard tools for mouse research and remain an attractive alternative even in the era of high-throughput whole-genome sequencing. Here, we describe the content and performance of a new iteration of the Mouse Universal Genotyping Array (MUGA), MiniMUGA, an array-based genetic QC platform with over 11,000 probes. In addition to robust discrimination between most classical and wild-derived laboratory strains, MiniMUGA was designed to contain features not available in other platforms: (1) chromosomal sex determination, (2) discrimination between substrains from multiple commercial vendors, (3) diagnostic SNPs for popular laboratory strains, (4) detection of constructs used in genetically engineered mice, and (5) an easy-to-interpret report summarizing these results. In-depth annotation of all probes should facilitate custom analyses by individual researchers. To determine the performance of MiniMUGA, we genotyped 6899 samples from a wide variety of genetic backgrounds. The performance of MiniMUGA compares favorably with three previous iterations of the MUGA family of arrays, both in discrimination capabilities and robustness. We have generated publicly available consensus genotypes for 241 inbred strains including classical, wild-derived, and recombinant inbred lines. Here, we also report the detection of a substantial number of XO and XXY individuals across a variety of sample types, new markers that expand the utility of reduced complexity crosses to genetic backgrounds other than C57BL/6, and the robust detection of 17 genetic constructs. We provide preliminary evidence that the array can be used to identify both partial sex chromosome duplication and mosaicism, and that diagnostic SNPs can be used to determine how long inbred mice have been bred independently from the relevant main stock. We conclude that MiniMUGA is a valuable platform for genetic QC, and an important new tool to increase the rigor and reproducibility of mouse research.

Abstract 4076: Gut microbiota and metabolite-driven phenotype modulation in a mouse model of colorectal cancer

Colorectal cancer (CRC) is a multifactorial disease that develops as a result of multiple genetic mutations, often including loss of the tumor suppressor Adenomatous Polyposis Coli (APC) gene. More recently, additional factors such as the host gut microbiota (GM) have also demonstrated an important role in tumor initiation and progression, yet our understanding of most commensal bacteria remains limited. We observed significant differences in intestinal tumor multiplicity between two ApcMin sub-strain mouse colonies; C57BL/6J-ApcMin (B6-Min/J) mice from The Jackson Laboratory had relatively lower adenoma burden while C57BL/6JD-ApcMin (B6-Min/D) mice from the University of Wisconsin develop twice the number of adenomas. To determine the underlying causes of this phenotypic variability, we used complex microbiota targeted rederivation (CMTR) to rederive embryos of the two Apc mutant sub-strains onto surrogate dams harboring distinct GM from two different vendors (GMJAX and GMHSD), generating four ApcMin groups: B6-Min/JGMJAX, B6-Min/JGMHSD, B6-Min/DGMJAX, and B6-Min/DGMHSD. We observed significant increases in intestinal tumor multiplicity in both B6-Min groups harboring the GMHSD compared to their GMJAX counterparts, suggesting that the GM accounts for a significant portion of variability in tumor phenotype between the ApcMin sub-strains. We characterized the GMJAX and GMHSD microbial populations using 16S rRNA gene sequencing to identify potentially causative and protective bacterial taxa. Relative abundances of several taxa including Bilophila sp., Desulfovibrio sp., and Akkermansia muciniphila, were significantly elevated in GMHSD suggesting pro-tumorigenic roles, while the family Peptococcaceae was more abundant in GMJAX, indicating a potential protective role. To establish the functional output of these distinct GM profiles contributing to tumor development, we used liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) to evaluate differences in the intestinal metabolome of the four experimental groups. Notably, we found that the microbiome differences due to colonization with either GMJAX or GMHSD primarily accounted for distinct metabolomic profiles, whereas host genetic differences between the sub-strains had a minimal role in shaping the metabolomes. We detected 31 putative metabolites that were significantly modulated by the GM in both the B6-Min/J and B6-Min/D sub-strains, and were therefore predictive of the relative tumor burden. Moving forward, these metabolites have implications for both biomarker discovery and potential therapeutic and preventative targets. Overall, these results provide insight regarding environmental factors influencing tumorigenesis, and further demonstrate how host-environment interactions can modulate a given disease phenotype.

Citation Format: Jacob E. Moskowitz, Zhentian Lei, Susheel Busi, Marcia Hart, Craig Franklin, Lloyd Sumner, James Amos-Landgraf. Gut microbiota and metabolite-driven phenotype modulation in a mouse model of colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4076.

Commentary on "Prognostic effect of carcinoma in situ in muscle-invasive urothelial carcinoma patients receiving neoadjuvant chemotherapy."

BACKGROUND

Carcinoma in situ (CIS) is a poor prognostic finding in urothelial carcinoma. However, its significance in muscle-invasive urothelial carcinoma (MIUC) treated with neoadjuvant chemotherapy (NAC) is uncertain. We assessed the effect of CIS found in pretreatment transurethral resection of bladder tumor (TURBT) biopsies on the pathologic and clinical outcomes.

MATERIALS AND METHODS

Subjects with MIUC treated with NAC before cystectomy were identified. The pathologic complete response (pCR) rates stratified by TURBT CIS status were compared. The secondary analyses included tumor response, progression-free survival (PFS), overall survival (OS), and an exploratory post hoc analysis of patients with pathologic CIS only (pTisN0) at cystectomy.

RESULTS

A total of 137 patients with MIUC were identified. TURBT CIS was noted in 30.7% of the patients. The absence of TURBT CIS was associated with a significantly increased pCR rate (23.2% vs. 9.5%; odds ratio = 4.08; 95% CI: 1.19-13.98; P = 0.025). Stage pTisN0 disease was observed in 19.0% of the TURBT CIS patients. TURBT CIS status did not significantly affect the PFS or OS outcomes. Post hoc analysis of the pTisN0 patients revealed prolonged median PFS (104.5 vs. 139.9 months; P = 0.055) and OS (104.5 vs. 152.3 months; P = 0.091) outcomes similar to those for the pCR patients.

CONCLUSION

The absence of CIS on pretreatment TURBT in patients with MIUC undergoing NAC was associated with increased pCR rates, with no observed differences in PFS or OS. Isolated CIS at cystectomy was frequently observed, with lengthy PFS and OS durations similar to those for pCR patients. Further studies aimed at understanding the biology and clinical effect of CIS in MIUC are warranted.

Thoughtflow: Standards and Tools for Provenance Capture and Workflow Definition to Support Model-Informed Drug Discovery and Development

Pharmacometric analyses are complex and multifactorial. It is essential to check, track, and document the vast amounts of data and metadata that are generated during these analyses (and the relationships between them) in order to comply with regulations, support quality control, auditing, and reporting. It is, however, challenging, tedious, error-prone, and time-consuming, and diverts pharmacometricians from the more useful business of doing science. Automating this process would save time, reduce transcriptional errors, support the retention and transfer of knowledge, encourage good practice, and help ensure that pharmacometric analyses appropriately impact decisions. The ability to document, communicate, and reconstruct a complete pharmacometric analysis using an open standard would have considerable benefits. In this article, the Innovative Medicines Initiative (IMI) Drug Disease Model Resources (DDMoRe) consortium proposes a set of standards to facilitate the capture, storage, and reporting of knowledge (including assumptions and decisions) in the context of model-informed drug discovery and development (MID3), as well as to support reproducibility: "Thoughtflow." A prototype software implementation is provided.

SMN deficiency alters the CNS and the peripheral immune system in a mouse model of spinal muscular atrophy (SMA)

Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by loss or mutation of the SMN1 gene. SMA rises from the insufficient levels of the ubiquitously expressed survival motor neuron (SMN) protein and is characterized by progressive α-lower motor neuron (LMN) degeneration and muscle atrophy. SMN is vital to all tissues, and the specific vulnerability of the LMN is still puzzling. However, currently there is a growing list of tissues affected in SMA. Recently, we have analyzed the development and the immune components of SMA spleen and found a selective reduction of the red pulp (RD) and RP macrophages in SMA mice, while white pulp and lymphocyte populations were largely preserved. Furthermore, previous studies suggested a role of glia cells in LMN pathology. These findings prompt us to investigate the role of the immune system in SMA pathogenesis. Looking into the cytokines production in the widely used “SMNΔ7” mouse model of SMA, we found that at steady state there is a higher production of the pro-inflammatory cytokines IL-1β, IL-6, and TNF-α in SMA central nervous system (CNS) that starts at an early symptomatic age and escalates at the late symptomatic time. However, the anti-inflammatory cytokine TGF-β had lower expression. Interestingly, after in vivo LPS stimulation, SMA astrocytes and splenocytes exhibit less potency in increasing the pro-inflammatory cytokines except for IL-1β that had significantly higher levels in SMA at all points. These findings suggest that there is a role of SMN in the homeostasis and function of resident macrophages in the CNS and the spleen, and denote a yet undiscovered immune component of SMA where targeting cytokines would be a potential new supportive therapy for SMA patients.

Influence of Chronic Exposure to Simulated Shift Work on Disease and Longevity in Disease-Prone Inbred Mice

Shift work (SW) is viewed as a risk factor for the development of many serious health conditions, yet prospective studies that document such risks are rare. The current study addressed this void by testing the hypothesis that long-term exposure to repeated diurnal phase shifts, mimicking SW, will accelerate disease onset or death in inbred mice with genetic risk of developing cancer, diabetes, or autoimmune disease. The data indicate that 1) life-long exposure to simulated SW accelerates death in female cancerprone AKR/J mice; 2) a significant proportion of male NON/ShiLtJ mice, which have impaired glucose tolerance but do not normally progress to type 2 diabetes, develop hyperglycemia, consistent with diabetes (that is, blood glucose 250 mg/dL or greater) after exposure to simulated SW for 8 wk; and 3) MRL/MpJ mice, which are prone to develop autoimmune disease, showed sex-related acceleration of disease development when exposed to SW as compared with mice maintained on a stable photocycle. Thus, longterm exposure to diurnal phase shifts that mimic SW reduces health or longevity in a wide variety of disease models. Our approach provides a simple way to assess the effect of chronic diurnal disruption in disease development in at-risk genotypes.

Long-term surgical anaesthesia with isoflurane in human habituated Nile Crocodiles

A suitable long-term anaesthetic technique was required for implantation of physiological sensors and telemetric devices in sub-adult Nile crocodiles (Crocodylus niloticus) to allow the collection of physiological data. Five Nile crocodiles with a median body mass of 24 kg were used. After manual capture, they were blindfolded and 0.2 mL (1 mg/mL) medetomidine was administered intramuscularly in four of the animals which had an estimated body mass between 20 kg and 30 kg. One crocodile with an estimated body mass of 50 kg received 0.5 mL. For induction, 5 mL propofol (10 mg/mL) was injected intravenously into the occipital sinus. Additional doses were given when required to ensure adequate anaesthesia. Anaesthesia was maintained with 1.5% isoflurane. Ventilation was controlled. Local anaesthesia was administered for surgical incision and external placement of the radio transmitter. Medetomidine was antagonised with atipamezole at the end of surgery. Median heart rate during surgery was 22 beats/min, at extubation 32 beats per min and 30 beats per min the following day at the same body temperature as under anaesthesia. Median body temperature of the animals increased from 27.3 °C to 27.9 °C during anaesthesia, as room temperature increased from 24.5 °C to 29.0 °C during surgery. Anaesthesia was successfully induced with intramuscular medetomidine and intravenous propofol and was maintained with isoflurane for the placement of telemetric implants. Intraoperative analgesia was supplemented with lidocaine infiltration. Perioperative physiological parameters remained stable and within acceptable clinical limits. Multiple factors appear to influence these variables during the recovery period, including residual anaesthetic effects, environmental temperature and physical activity.

Immobility reactions under threat: A contribution to human defensive cascade and PTSD

Violence exacts a burden on public health. Gun violence is a major trigger for motor defensive reactions in humans and post-traumatic stress disorder (PTSD) is its main psychiatric sequela. However, studies of the human defensive cascade, especially the motor reactions, are at an early stage. This review focuses on studies that employ stabilometry, a methodology that assesses whole body motor reactions, to address defensive behaviors to violence-related threats. Special attention is given to three reactions: "attentive immobility", "immobility under attack" and "tonic immobility", with emphasis on the latter - a peritraumatic reaction which has been strongly associated with the severity of PTSD. These reactions are characterized by reduced body sway and bradycardia, except tonic immobility that presents robust tachycardia. The advances made by investigations into the immobility reactions of the human defensive cascade contribute to helping to bridge the gap between human and non-human species. Furthermore, progresses in basic research to objectively monitor motor defensive reactions under threat can help to develop a dimensional, trans-diagnostic approach to PTSD.

Immunotherapy in melanoma: Recent advances and future directions

Malignant melanoma contributes the majority of skin cancer related deaths and shows an increasing incidence in the past years. Despite all efforts of early diagnosis, metastatic melanoma still has a poor prognosis and remains a challenge for treating physicians. In recent years, improved knowledge of the pathophysiology and a better understanding of the role of the immune system in tumour control have led to the development and approval of several immunotherapies. Monoclonal antibodies against different immune checkpoints have been revolutionizing the treatment of metastatic and unresectable melanoma. Ipilimumab, a monoclonal antibody against the cytotoxic T-lymphocyte antigen 4 (CTLA-4) as well as nivolumab and pembrolizumab which target the programmed cell death protein 1 (PD-1) have been shown to prolong overall survival in patients with advanced melanoma. The latter substances seem to have an increased response rate and more tolerable safety profile compared to ipilimumab. The combination of a CTLA-4 and a PD-1 inhibitor seems to be superior to the monotherapies, especially in patients with PD-L1 negative tumours. Checkpoint inhibitors are currently being tested in the adjuvant setting with initial data for ipilimumab suggesting efficacy in this context. Talimogene laherparepvec (TVEC) is the first oncolytic virus approved in the therapy of metastatic melanoma offering a treatment option especially for patients with limited disease. In this review, data on these recently developed and approved immunotherapies are presented. However, further studies are necessary to determine the optimal duration, sequencing and combinations of immunotherapies to further improve the outcome of patients with advanced melanoma.

TNF receptor type 2 (TNFR2) in the maintenance of gut microbiota and autoimmune disease susceptibility

Tumor necrosis factor (TNF) antagonism is therapeutic for some inflammatory autoimmune disorders such as Crohn’s disease and rheumatoid arthritis. However, TNF blockade inexplicably exacerbates CNS autoimmunity, including multiple sclerosis. We now demonstrate that selective TNFR2 deficiency augments spontaneous autoimmunity in female, but not male, myelin oligodendrocyte glycoprotein (MOG)–specific 2D2 TCR transgenic mice. Disease in TNFR2−/− 2D2 mice correlates with CNS lymphocyte infiltration and increased myelin oligodendrocyte glycoprotein–induced IL-17, IFN-γ, and IgG2b production. Attenuated disease in TNF−/− 2D2 mice relative to TNFR2−/− 2D2 mice identified distinctive roles for TNFR1 and TNFR2. Antibiotic treatment eliminated spontaneous autoimmunity in TNFR2−/− 2D2 mice to suggest a role for gut microbiota. Illumina sequencing of fecal 16S rRNA identified a distinct microbiota profile in male TNFR2−/− 2D2 mice that associated with disease protection. While Akkermansia muciniphila, Sutterella sp., Oscillospira sp., Bacteroides acidifaciens, and Anaeroplasma sp. were selectively more abundant in male TNFR2−/− 2D2 mice, Bacteroides sp., Bacteroides uniformis, and Parabacteroides sp. were more abundant in affected female TNFR2−/− 2D2 mice. Overall, selective TNFR2 blockade appears to target commensal bacteria–host immune dysbiosis to potentiate autoimmunity in genetically susceptible female mice. Under this paradigm, microbes likely contribute to an individual’s response to anti-TNF therapy. This model provides a foundation for host immune–microbiota-directed measures for the prevention and treatment of CNS-demyelinating autoimmune disorders.

Abstract 2880: Modulating disease susceptibility in a model of human colon cancer by microbiome rederivation

To understand the impact of differences in complex microbiota on colon cancer susceptibility, we utilized the Pirc (Polyposis In Rat Colon) model of familial human colon cancer to correlate the longitudinal changes of the gut microbiota with early adenoma development. Recent human epidemiologic studies have shown associations of gut microbiota differences in patients with colorectal cancer vs. controls.

To test if differences in the gut microbiota modulate susceptibility, we used the F344/NTac-ApcPirc/+ rat model and altered the microbiome through embryo rederivation using three distinct strains of surrogate dams: F344/NHsd, LEW/SsNHsd, and Crl:SD, all harboring different commensal microbiota. Fecal samples from the pups and dams were collected at various time points. Extracted DNA was sequenced using the Illumina MiSeq platform for the 16S rRNA gene V4 hypervariable region. Adenoma development was monitored periodically via colonoscopy and terminal tumor counts and histology were performed at 180 days. We found the complex microbiota of the surrogates to be distinct from one another and that the pups resembled their respective dams. At the terminal time-point, rats harboring the LEW microbiota had significantly reduced colonic tumor burden (number and size) compared to both F344 (p<0.001) and SD (p<0.05). Colonic tumors were also absent in 2 of the 15 rederived pups with the LEW microbiota reducing the Pirc phenotype penetrance from 100% to 87%.

At weaning, we found the LEW microbiota to be unique with a high percentage of Prevotella copri. Pups with the LEW microbiota also differed significantly from the other pups by an additional 8 operational taxonomic units (OTUs). At 6 months of age, the relative abundance of P. copri, and 5 additional OTUs correlated with decreased tumor burden in these pups (Spearman’s, p≤0.05). Conversely, higher prevalence of family Peptococcaceae and Akkermansia muciniphila were positively correlated (p<0.05) with increased tumor number. Histological analysis of colons from the LEW and SD offspring showed significant goblet cell hyperplasia (p<0.002) in the distal colon of the LEW pups. No aberrant crypt foci (ACF) or microadenomas were found in the two LEW pups that did not harbor colonic adenomas, indicating a possible inhibition of initiation. Immunohistochemical staining for Ki67 showed that the proliferation index of both the normal epithelium and tumors in the SD group was trending significantly higher compared to the LEW rats.

Our results indicate that microbial alteration through rederivation affects colon cancer susceptibility. The prevalence or lack of specific OTUs at weaning can potentially serve as predictors of tumor burden at later stages. More importantly, the study points towards differences in the microbiota of the offspring acting as modulators of disease phenotype affecting initiation or progression of colon cancer.

Citation Format: James Amos-Landgraf, Susheel Busi, Aaron Ericsson, Marina McCoy, Taybor Parker, Rebecca Schehr, Miriam Hankins, Craig Franklin, Elizabeth Bryda. Modulating disease susceptibility in a model of human colon cancer by microbiome rederivation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2880. doi:10.1158/1538-7445.AM2015-2880

Reproducibility: use mouse biobanks or lose them

Now that genetic engineering of mice is so easy, centralized repositories are essential, argue Kent Lloyd and colleagues.

Pharmacometrics Markup Language (PharmML): Opening New Perspectives for Model Exchange in Drug Development

The lack of a common exchange format for mathematical models in pharmacometrics has been a long-standing problem. Such a format has the potential to increase productivity and analysis quality, simplify the handling of complex workflows, ensure reproducibility of research, and facilitate the reuse of existing model resources. Pharmacometrics Markup Language (PharmML), currently under development by the Drug Disease Model Resources (DDMoRe) consortium, is intended to become an exchange standard in pharmacometrics by providing means to encode models, trial designs, and modeling steps.

Pathological findings in wild harvested dugongs Dugong dugon of central Torres Strait, Australia

The dugong Dugong dugon is classified as Vulnerable to extinction but may be endangered in some regions. Cause of death in stranded dugongs has not been determined in a large proportion of animals examined, with investigations hindered by limited information on dugong health and diseases, and paucity of knowledge of common or endemic pathological findings. Here we describe pathological findings in harvested dugongs from the relatively pristine area of central Torres Strait, and we characterise lesions attributable to drowning. Other recorded lesions were mild and predominated by host reaction to the presence of trematodes within the gastrointestinal tracts, liver and pancreas. Ascarid worm burdens were low in comparison to dugongs from developed coastlines. Hepatocellular lipofuscin and ferritin pigmentation were commonly observed, more pronounced in livers of older animals and concurrent with periportal and bridging fibrosis. Lesions attributable to drowning included incomplete collapse of lungs, dorsal or diffuse pulmonary congestion, mild intra-alveolar haemorrhage and oedema, mild interstitial oedema and rupture of peripheral alveolar septae with acute myofibre fragmentation and degeneration. No accumulation of foam or aspiration of water or particulate matter was observed, suggesting that dugongs 'dry drown'. Morphometric features of normal spleen are also presented. Characterisation of common pathological findings and those attributable to drowning in this species will aid in the interpretation of post mortem findings for the significant number of dugongs found deceased along urbanised coastlines.

Twenty-eight loci that influence serum urate levels: analysis of association with gout

OBJECTIVES

Twenty-eight genetic loci are associated with serum urate levels in Europeans. Evidence for association with gout at most loci is absent, equivocal or not replicated. Our aim was to test the loci for association with gout meeting the American College of Rheumatology gout classification criteria in New Zealand European and Polynesian case-control sample sets.

METHODS

648 European cases and 1550 controls, and 888 Polynesian (Ma¯ori and Pacific) cases and 1095 controls were genotyped. Association with gout was tested by logistic regression adjusting for age and sex. Power was adequate (>0.7) to detect effects of OR>1.3.

RESULTS

We focused on 24 loci without previous consistent evidence for association with gout. In Europeans, we detected association at seven loci, one of which was the first report of association with gout (IGF1R). In Polynesian, association was detected at three loci. Meta-analysis revealed association at eight loci-two had not previously been associated with gout (PDZK1 and MAF). In participants with higher Polynesian ancestry, there was association in an opposing direction to Europeans at PRKAG2 and HLF (HLF is the first report of association with gout). There was obvious inconsistency of gout association at four loci (GCKR, INHBC, SLC22A11, SLC16A9) that display very similar effects on urate levels.

CONCLUSIONS

We provide the first evidence for association with gout at four loci (IGF1R, PDZK1, MAF, HLF). Understanding why there is lack of correlation between urate and gout effect sizes will be important in understanding the aetiology of gout.

Centralized mouse repositories

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

A randomized controlled study to assess patients' understanding of and consenting for clinical trials using two different consent form presentations

BACKGROUND

Informed consent is the ethical basis for clinical research. The physical appearance of the consent document may influence patients' willingness to carefully read the consent document. We therefore tested the hypothesis that presentation of consent documents in an enhanced format improves patients' attention, understanding and therefore willingness to consent for clinical research.

METHODS

Patients being asked to participate in three large clinical trials were randomly assigned to enhanced or routine presentation. The enhanced document was printed on 20-pound, cream-colored bond paper and presented in a blue folio. In contrast, patients assigned to routine presentation were given an otherwise identical stapled set of photocopied pages. The primary outcome was the effect of the enhanced format on the proportion of patients consenting; the major secondary outcome was patient's understanding of the presented procedures and risks.

RESULTS

A total of 189 of 251 (75%) patients approached with standard format consenting documents consented for an underlying study, whereas 164 of 248 (66%) approached with enhanced format documents consented; the adjusted odds ratio (95% confidence interval) for consenting (comparing enhanced to standard formats) was 0.64 (0.43, 0.95), P=0.03. About 90% of the patients in each group correctly identified the major study intervention and major associated risk. Neither patients' characteristics nor understanding affected the consenting rate for the presented clinical research.

CONCLUSION

Consent forms in an enhanced format (i.e., printed on fine paper and presented in a folio) did not improve patients' understanding or willingness to consent to participate in clinical trials.

Each to their own: skeletal muscles of different function use different biochemical strategies during aestivation at high temperature

Preservation of muscle morphology depends on a continuing regulatory balance between molecules that protect, and molecules that damage, muscle structural integrity. Excessive disruption of the biochemical balance that favours reactive oxygen species (ROS) in disused muscles may lead to oxidative stress; which in turn is associated with increased atrophic or apoptotic signalling and/or oxidative damage to the muscle and thus muscle disuse atrophy. Increases in rate of oxygen consumption likely increase the overall generation of ROS in vivo. Temperature-induced increases in muscle oxygen consumption rate occur in some muscles of ectotherms undergoing prolonged muscular disuse during aestivation. In the green-striped burrowing frog, Cyclorana alboguttata, both large jumping muscles and small non-jumping muscles undergo atrophy seemingly commensurate with their rate of oxygen consumption during aestivation. However, since the extent of atrophy in these muscles is not enhanced at higher temperatures despite a temperature sensitive rate of oxygen consumption in the jumping muscle, we proposed that muscles are protected by biochemical means that when mobilised at higher temperatures inhibit atrophy. We proposed the biochemical response to temperature would be muscle-specific. We examined the effect of temperature on the antioxidant and heat shock protein systems and evidence of oxidative damage to lipids and proteins in two functionally different skeletal muscles, gastrocnemius (jumping muscle) and iliofibularis (non-jumping muscle), by aestivating frogs at 24 and 30oC for six months. We assayed small molecule antioxidant capacity, mitochondrial and cytosolic SOD and Hsp70 to show that protective mechanisms in disused muscles are differentially regulated both with respect to temperature and aestivation. High aestivation temperature results in an antioxidant response in the metabolically temperature-sensitive jumping muscle. We assayed lipid peroxidation and protein oxidation to show that oxidative damage is apparent during aestivation and its pattern is muscle-specific, but unaffected by temperature. Consideration is given to how the complex responses of muscle biochemistry inform of the different strategies muscles may use in regulating their oxidative environment during extended disuse and disuse at high temperature.

Isolation and characterization of a population of stem-like progenitor cells from an atypical meningioma

The majority of meningiomas are benign tumors associated with favorable outcomes; however, the less common aggressive variants with unfavorable outcomes often recur and may be due to subpopulations of less-differentiated cells residing within the tumor. These subpopulations of tumor cells have tumor-initiating properties and may be isolated from heterogeneous tumors when sorted or cultured in defined medium. We report the isolation and characterization of a population of tumor-initiating cells derived from an atypical meningioma. We identify a tumor-initiating population from an atypical meningioma, termed meningioma-initiating cells (MICs). These MICs self-renew, differentiate, and can recapitulate the histological characteristics of the parental tumor when transplanted at 1000 cells into the flank regions of athymic nude mice. Immunohistochemistry reveals stem-like protein expression patterns similar to neural stem and progenitor cells (NSPCs) while genomic profiling verified the isolation of cancer cells (with defined meningioma chromosomal aberrations) from the bulk tumor. Microarray and pathway analysis identifies biochemical processes and gene networks related to aberrant cell cycle progression, particularly the loss of heterozygosity of tumor suppressor genes CDKN2A (p16(INK4A)), p14(ARF), and CDKN2B (p15(INK4B)). Flow cytometric analysis revealed the expression of CD44 and activated leukocyte adhesion molecule (ALCAM/CD166); these may prove to be markers able to identify this cell type. The isolation and identification of a tumor-initiating cell population capable of forming meningiomas demonstrates a useful model for understanding meningioma development. This meningioma model may be used to study the cell hierarchy of meningioma tumorogenesis and provide increased understanding of malignant progression.

Dissociation of long-term verbal memory and fronto-executive impairment in first-episode psychosis

BACKGROUND

Verbal memory is frequently and severely affected in schizophrenia and has been implicated as a mediator of poor clinical outcome. Whereas encoding deficits are well demonstrated, it is unclear whether retention is impaired. This distinction is important because accelerated forgetting implies impaired consolidation attributable to medial temporal lobe (MTL) dysfunction whereas impaired encoding and retrieval implicates involvement of prefrontal cortex.

METHOD

We assessed a group of healthy volunteers (n=97) and pre-morbid IQ- and sex-matched first-episode psychosis patients (n=97), the majority of whom developed schizophrenia. We compared performance of verbal learning and recall with measures of visuospatial working memory, planning and attentional set-shifting, and also current IQ.

RESULTS

All measures of performance, including verbal memory retention, a memory savings score that accounted for learning impairments, were significantly impaired in the schizophrenia group. The difference between groups for delayed recall remained even after the influence of learning and recall was accounted for. Factor analyses showed that, in patients, all variables except verbal memory retention loaded on a single factor, whereas in controls verbal memory and fronto-executive measures were separable.

CONCLUSIONS

The results suggest that IQ, executive function and verbal learning deficits in schizophrenia may reflect a common abnormality of information processing in prefrontal cortex rather than specific impairments in different cognitive domains. Verbal memory retention impairments, however, may have a different aetiology.

Clostridial typhlitis associated with topical antibiotic therapy in a Syrian hamster

A Syrian hamster that had been treated with topical antibiotic ointment for 10 days following injuries sustained during fighting was presented moribund. Postmortem and microscopic examinations revealed lesions consistent with clostridial typhlitis and enteritis. Anaerobic culture of caecal contents resulted in the isolation of two Clostridium species, and caecal contents contained Clostridium difficile enterotoxins. Based on these findings, a diagnosis of acute C. difficile enterotoxaemia was made. This report discusses the pathogenesis of C. difficile enterotoxaemia and the potential role of topical antibiotic ointment therapy in initiating the disease.

Multiplex fluorescent immunoassay for the simultaneous detection of serum antibodies to multiple rodent pathogens

Multiplex Fluorescent Immunoassay (MFI) is a sensitive and specific serologic test that allows simultaneous detection of antibodies to multiple viral and bacterial agents in a single reaction well. MFI is a high-throughput assay that offers several advantages over other prevalent assays, and some research animal diagnostic laboratories have adopted it as their primary technique. The authors present a detailed review of MFI and its application to laboratory animal diagnostics.

Comparative medicine for clinicians

This article reviews comparative medicine for the physician-clinician. It will highlight the research done at the University of Missouri.

Visualizing mechanisms of peripheral tolerance against autoreactive T cells (129.35)

Where and how T cell tolerance happens remains largely undefined. Here, we used an established in vivo model and investigated the site and the mechanisms that govern APC-mediated inactivation of autoreactive T cells.

Fcγ receptor-deficient (FcγR−/−) mice were induced for experimental allergic encephalomyelitis (EAE), with a myelin oligodendrocyte glycoprotein (MOG) 35-55 peptide and when the disease became apparent the mice were given FcγR+/+ APCs and treated with Ig-MOG, a tolerogenic Ig expressing MOG peptide. Under this regimen the mice were able to reverse their EAE only when given FcγR+/+ APCs that can present Ig-MOG and carry out T cell tolerance. This system was then used to visualize encounter of the APCs with the pathogenic T cells. The results indicate that tolerance occurs in a time dependent fashion when both the T cells and APCs have accumulated in sufficient number at the encounter site but unlike immunity, can take place in the non-draining lymph nodes. Two-Photon microscopy analysis revealed that tolerized T cells exhibit organ-specific changes in motility, pattern of migration and trafficking which could be related to functional matters as tolerance manifest the form of Th2 deviation in the lymph node and anergy in the spleen.

Research supported by grant NS37406 from NIH.

Complete blood count, clinical chemistry, and serology profile by using a single tube of whole blood from mice

Clinical pathology is a valuable means for assessing specific organ pathology and a screening tool for general animal health. Routine clinical pathology evaluation in mice usually includes whole blood for a complete blood count (CBC) and a clinical biochemistry analysis. Acquisition and analysis of these samples can be problematic due to the small volumes of blood that can be obtained from a mouse. Typically, a complete blood count requires blood from a tube containing an anticoagulant, whereas a clinical biochemistry profile needs blood from a serum clot tube. Because of the small volume that can be obtained, splitting the blood from a single mouse into 2 different tubes may result in inadequate samples to perform the desired tests or introduce inaccuracies. We explored the feasibility of using a single lithium heparin tube for generation of a CBC, biochemistry profile, and serology profile. We also evaluated the consistency of CBC data, including the quality of a peripheral blood smear taken from a lithium heparin or EDTA tube after various storage times. We found that CBC, biochemistry, and serology profiles could be obtained more readily when blood samples were placed in a single lithium heparin tube than in 2 separate tubes. In addition, the quality of blood smears and CBC results from the lithium heparin tube were comparable (with few exceptions) to those from an EDTA tube after prolonged storage.