Perturbed liver gene zonation in a mouse model of non-alcoholic steatohepatitis.

Liver zonation characterizes the separation of metabolic pathways along the lobules and is required for optimal hepatic function. Wnt signaling is a master regulator of spatial liver zonation. A perivenous-periportal Wnt activity gradient orchestrates metabolic zonation by activating gene expression in perivenous hepatocytes, while suppressing gene expression in their periportal counterparts. However, the understanding as to the liver gene zonation and zonation regulators in diseases is limited. Non-alcoholic steatohepatitis (NASH) is a chronic liver disease characterized by fat accumulation, inflammation, and fibrosis. Here, we investigated the perturbation of liver gene zonation in a mouse NASH model by combining spatial transcriptomics, bulk RNAseq and in situ hybridization. Wnt-target genes represented a major subset of genes showing altered spatial expression in the NASH liver. The altered Wnt-target gene expression levels and zonation spatial patterns were in line with the up regulation of Wnt regulators and the augmentation of Wnt signaling. Particularly, we found that the Wnt activator Rspo3 expression was restricted to the perivenous zone in control liver but expanded to the periportal zone in NASH liver. AAV8-mediated RSPO3 overexpression in controls resulted in zonation changes, and further amplified the disturbed zonation of Wnt-target genes in NASH, similarly Rspo3 knockdown in Rspo3+/- mice resulted in zonation changes of Wnt-target genes in both chow and HFD mouse. Interestingly, there were no impacts on steatosis, inflammation, or fibrosis NASH pathology from RSPO3 overexpression nor Rspo3 knockdown. In summary, our study demonstrated the alteration of Wnt signaling in a mouse NASH model, leading to perturbed liver zonation.

Single-cell RNA transcriptome landscape of hepatocytes and non-parenchymal cells in healthy and NAFLD mouse liver.

Nonalcoholic fatty liver disease (NAFLD) is a global health-care problem with limited therapeutic options. To obtain a cellular resolution of pathogenesis, 82,168 single-cell transcriptomes (scRNA-seq) across different NAFLD stages were profiled, identifying hepatocytes and 12 other non-parenchymal cell (NPC) types. scRNA-seq revealed insights into the cellular and molecular mechanisms of the disease. We discovered a dual role for hepatic stellate cells in gene expression regulation and in the potential to trans-differentiate into myofibroblasts. We uncovered distinct expression profiles of Kupffer cells versus monocyte-derived macrophages during NAFLD progression. Kupffer cells showed stronger immune responses, while monocyte-derived macrophages demonstrated a capability for differentiation. Three chimeric NPCs were identified including endothelial-chimeric stellate cells, hepatocyte-chimeric endothelial cells, and endothelial-chimeric Kupffer cells. Our work identified unanticipated aspects of mouse with NAFLD at the single-cell level and advanced the understanding of cellular heterogeneity in NAFLD livers.

Use of 3-dimensional printing in surgical exploration of a nasolacrimal duct obstruction in a dog.

A 1.5-year-old spayed female English setter dog was presented because of mucopurulent discharge emanating from the left medial canthal region of 8-months duration despite medical management and repeated nasolacrimal flushing. Dacryocystorhinography demonstrated obstruction at the level of the lacrimal sac. Three-dimensional (3-D) modelling software was used to print a 3-D construct of the facial bones and a drill guide over the region of obstruction. The 3-D prints were sterilized and utilized during surgery to facilitate access to the lacrimal sac. The left lacrimal sac was identified, explored, and flushed. Patency was re-established, and the dog was asymptomatic 7 months after surgery.

Utilisation d'une imprimante 3-dimensions dans l'exploration chirurgicale d'une obstruction du canal naso-lacrymal chez un chien. Une chienne stérilisée de race Setter anglais âgée de 1,5 ans fut présentée à cause d'un écoulement muco-purulent provenant de la région du canthus médial gauche qui dure depuis 8 mois malgré une gestion médicale et des drainages naso-lacrymaux répétés. Une dacryocystorhinographie a démontré l'obstruction au niveau du sac lacrymal. Un logiciel de modélisation en trois dimensions (3-D) fut utilisé pour imprimer un construit en 3-D des os faciaux et un guide-mèche de la région au-dessus de l'obstruction. Les impressions 3-D furent stérilisées et utilisées durant la chirurgie afin de faciliter l'accès au sac lacrymal. Le sac lacrymal gauche fut identifié, exploré et drainé. La perméabilité fut ré-établie, et le chien était asymptomatique 7 mois après la chirurgie.(Traduit par Dr Serge Messier).

Clinical Utility of a Fully Automated Microsatellite Instability Test with Minimal Hands-on Time.

BACKGROUND: Microsatellite instability (MSI) analysis is becoming increasingly important in many types of tumor including colorectal cancer (CRC). The commonly used MSI tests are either time-consuming or labor-intensive. A fully automated MSI test, the Idylla MSI assay, has recently been introduced. However, its diagnostic performance has not been extensively validated in clinical CRC samples. METHODS: We evaluated 133 samples whose MSI status had been rigorously validated by standard polymerase chain reaction (PCR), clinical nextgeneration sequencing (NGS) cancer panel test, or both. We evaluated the diagnostic performance of the Idylla MSI assay in terms of sensitivity, specificity, and positive and negative predictive values, as well as various sample requirements, such as minimum tumor purity and the quality of paraffin blocks. RESULTS: Compared with the gold standard results confirmed through both PCR MSI test and NGS, the Idylla MSI assay showed 99.05% accuracy (104/105), 100% sensitivity (11/11), 98.94% specificity (93/94), 91.67% positive predictive value (11/12), and 100% negative predictive value (93/93). In addition, the Idylla MSI assay did not require macro-dissection in most samples and reliably detected MSI-high in samples with approximately 10% tumor purity. The total turnaround time was about 150 minutes and the hands-on time was less than 2 minutes. CONCLUSIONS: The Idylla MSI assay shows good diagnostic performance that is sufficient for its implementation in the clinic to determine the MSI status of at least the CRC samples. In addition, the fully automated procedure requires only a few slices of formalin-fixed paraffin-embedded tissue and might greatly save time and labor.

Mutation Burden and I Index for Detection of Microsatellite Instability in Colorectal Cancer by Targeted Next-Generation Sequencing.

Next-generation sequencing (NGS) panels are widely used for defining tumor mutation profiles and determining treatment approaches. We performed targeted NGS with 382 colorectal cancer genes with known microsatellite instability (MSI). After exclusion of germline alterations, the load of somatic mutations and small insertion/deletion (indel) alterations were determined. In the test set, 79 patients with 41 microsatellite-stable (MSS) and 38 MSI tumors were included. There were 120 MSS and eight MSI-high tumors in the validation set. The number of somatic mutations of whole samples were distinguished into three groups: mutant functional polymerase epsilon catalytic subunit, MSI, and MSS tumors. The median numbers of somatic and indel mutations in MSI tumors were higher. The indel mutation to whole mutation ratio (I index) was higher in MSI tumors. Hypermutation and low I index of polymerase epsilon catalytic subunit mutant tumors, a somatic mutation load cut-off of ≥40, and an I index of ≥9% were selected as the criteria for detecting MSI tumors with high sensitivity and specificity. With the analysis of alteration patterns of homopolymer genes, a higher median number of homopolymer mutations in MSI tumors was observed. Mutated homopolymer ≥5 was selected as the criterion for detecting MSI tumors. MSI in colorectal cancer can be detected by targeted NGS panels with high sensitivity and specificity using somatic mutation load and I index.

Erratum: Asparagine bioavailability governs metastasis in a model of breast cancer.

This corrects the article DOI: 10.1038/nature25465.

Glucagon contributes to liver zonation.

Liver zonation characterizes the separation of metabolic pathways along the lobules and is required for optimal function. Wnt/ß-catenin signaling controls metabolic zonation by activating genes in the perivenous hepatocytes, while suppressing genes in the periportal counterparts. We now demonstrate that glucagon opposes the actions of Wnt/ß-catenin signaling on gene expression and metabolic zonation pattern. The effects were more pronounced in the periportal hepatocytes where 28% of all genes were activated by glucagon and inhibited by Wnt/ß-catenin. The glucagon and Wnt/ß-catenin receptors and their signaling pathways are uniformly distributed in periportal and perivenous hepatocytes and the expression is not regulated by the opposing signal. Collectively, our results show that glucagon controls gene expression and metabolic zonation in the liver through a counterplay with the Wnt/ß-catenin signaling pathway.

A Protein-Truncating HSD17B13 Variant and Protection from Chronic Liver Disease.

BACKGROUND: Elucidation of the genetic factors underlying chronic liver disease may reveal new therapeutic targets. METHODS: We used exome sequence data and electronic health records from 46,544 participants in the DiscovEHR human genetics study to identify genetic variants associated with serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Variants that were replicated in three additional cohorts (12,527 persons) were evaluated for association with clinical diagnoses of chronic liver disease in DiscovEHR study participants and two independent cohorts (total of 37,173 persons) and with histopathological severity of liver disease in 2391 human liver samples. RESULTS: A splice variant (rs72613567:TA) in HSD17B13, encoding the hepatic lipid droplet protein hydroxysteroid 17-beta dehydrogenase 13, was associated with reduced levels of ALT (P=4.2×10-12) and AST (P=6.2×10-10). Among DiscovEHR study participants, this variant was associated with a reduced risk of alcoholic liver disease (by 42% [95% confidence interval {CI}, 20 to 58] among heterozygotes and by 53% [95% CI, 3 to 77] among homozygotes), nonalcoholic liver disease (by 17% [95% CI, 8 to 25] among heterozygotes and by 30% [95% CI, 13 to 43] among homozygotes), alcoholic cirrhosis (by 42% [95% CI, 14 to 61] among heterozygotes and by 73% [95% CI, 15 to 91] among homozygotes), and nonalcoholic cirrhosis (by 26% [95% CI, 7 to 40] among heterozygotes and by 49% [95% CI, 15 to 69] among homozygotes). Associations were confirmed in two independent cohorts. The rs72613567:TA variant was associated with a reduced risk of nonalcoholic steatohepatitis, but not steatosis, in human liver samples. The rs72613567:TA variant mitigated liver injury associated with the risk-increasing PNPLA3 p.I148M allele and resulted in an unstable and truncated protein with reduced enzymatic activity. CONCLUSIONS: A loss-of-function variant in HSD17B13 was associated with a reduced risk of chronic liver disease and of progression from steatosis to steatohepatitis. (Funded by Regeneron Pharmaceuticals and others.).

Asparagine bioavailability governs metastasis in a model of breast cancer.

Using a functional model of breast cancer heterogeneity, we previously showed that clonal sub-populations proficient at generating circulating tumour cells were not all equally capable of forming metastases at secondary sites. A combination of differential expression and focused in vitro and in vivo RNA interference screens revealed candidate drivers of metastasis that discriminated metastatic clones. Among these, asparagine synthetase expression in a patient's primary tumour was most strongly correlated with later metastatic relapse. Here we show that asparagine bioavailability strongly influences metastatic potential. Limiting asparagine by knockdown of asparagine synthetase, treatment with l-asparaginase, or dietary asparagine restriction reduces metastasis without affecting growth of the primary tumour, whereas increased dietary asparagine or enforced asparagine synthetase expression promotes metastatic progression. Altering asparagine availability in vitro strongly influences invasive potential, which is correlated with an effect on proteins that promote the epithelial-to-mesenchymal transition. This provides at least one potential mechanism for how the bioavailability of a single amino acid could regulate metastatic progression.

Neuronal functions of FOXO/DAF-16.

The FOXO family of transcription factors plays a conserved role in longevity and tissue homeostasis across species. In the mammalian nervous system, emerging evidence has implicated FOXOs in cognitive performance, stem cell maintenance, regeneration, and protection against stress. Much of what we know about neuronal functions of FOXO emerged from recent studies in C. elegans. Similar to mammalian FOXO, the worm FOXO ortholog, called DAF-16, regulates learning and memory, regeneration, and stress resistance in neurons. Here, we discuss the current state of our knowledge of FOXO's functions in neurons in mammals and invertebrates, and highlight areas where our understanding is limited. Defining the function of FOXO factors in the healthy, aged, and diseased brain may have important implications for improving healthspan and treating neurodegenerative disease.

Glucagon receptor inhibition normalizes blood glucose in severe insulin-resistant mice.

Inactivating mutations in the insulin receptor results in extreme insulin resistance. The resulting hyperglycemia is very difficult to treat, and patients are at risk for early morbidity and mortality from complications of diabetes. We used the insulin receptor antagonist S961 to induce severe insulin resistance, hyperglycemia, and ketonemia in mice. Using this model, we show that glucagon receptor (GCGR) inhibition with a monoclonal antibody normalized blood glucose and ß-hydroxybutyrate levels. Insulin receptor antagonism increased pancreatic ß-cell mass threefold. Normalization of blood glucose levels with GCGR-blocking antibody unexpectedly doubled ß-cell mass relative to that observed with S961 alone and 5.8-fold over control. GCGR antibody blockage expanded α-cell mass 5.7-fold, and S961 had no additional effects. Collectively, these data show that GCGR antibody inhibition represents a potential therapeutic option for treatment of patients with extreme insulin-resistance syndromes.

Dalotuzumab in chemorefractory KRAS exon 2 mutant colorectal cancer: Results from a randomised phase II/III trial.

Limited data are available on the efficacy of anti-IGF-1R agents in KRAS mutant colorectal cancer (CRC). We analysed the outcome of 69 chemorefractory, KRAS exon 2 mutant CRC patients who were enrolled in a double-blind, randomised, phase II/III study of irinotecan and cetuximab plus dalotuzumab 10 mg/kg once weekly (arm A), dalotuzumab 7.5 mg/kg every second week (arm B) or placebo (arm C). Objective response rate (5.6% vs. 3.1% vs. 4.8%), median progression-free survival (2.7 vs. 2.6 vs. 1.4 months) and overall survival (7.8 vs. 10.3 vs. 7.8 months) were not statistically significantly different between treatment groups. Most common grade ≥3 treatment-related toxicities included neutropenia, diarrhoea, hyperglycaemia, fatigue and dermatitis acneiform. Expression of IGF-1R, IGF-1, IGF-2 and EREG by quantitative real-time polymerase chain reaction was assessed in 351 patients from the same study with available data on KRAS exon 2 mutational status. Median cycle threshold values for all biomarkers were significantly lower (i.e., higher expression, p < 0.05) among patients with KRAS wild-type compared to those with KRAS exon 2 mutant tumours. No significant changes were found according to location of the primary tumour with only a trend towards lower expression of IGF-1 in colon compared to rectal cancers (p = 0.06). Albeit limited by the small sample size, this study does not appear to support a potential role for anti-IGF-1R agents in KRAS exon 2 mutant CRC. Data on IGF-1R, IGF-1 and IGF-2 expression here reported may be useful for patient stratification in future trials with inhibitors of the IGF pathway.

Juglone ameliorates skin wound healing by promoting skin cell migration through Rac1/Cdc42/PAK pathway.

Skin cell regeneration and wound healing are key processes in the recovery from skin injuries. Rapid cell migration and regeneration of skin cells lead to faster and better healing of wounded skin. In the present study, we aimed to investigate the wound healing potential of juglone, a naturally occurring Pin1 inhibitor found in walnuts. Cultured skin cells (NHDF and HaCaT) and hairless mice were treated with juglone after wound creation to examine its effects on cell migration and wound healing rate. The expressions of cell migration related proteins (Rac1, Cdc42, and α-PAK), collagen deposition, and angiogenesis were analyzed. Juglone treatment resulted in faster rate of growth and migration and recovered cell morphology, particularly at a concentration of 5 µM, in skin cells compared to the untreated group. In vivo experiments showed that mice treated with juglone showed faster wound healing rate with better skin morphology and collagen deposition than the vehicle group. Furthermore, juglone increased the activation and/or expression of Cdc42, Rac1, and α-pak in HaCaT cells, and resulted in enhanced angiogenesis in endothelial cells (HUVECs). Juglone also activated MAPKs signaling by activation of ERK, JNK, and p38 proteins. Taken together, these data suggest that juglone may be a potential candidate for wound healing and skin regeneration which ameliorates wound healing mainly by promoting skin cell migration through Rac1/Cdc42/PAK pathway.

Description and Biomechanical Comparison of a Percutaneous Radiologic Gastropexy Technique in a Canine Cadaver Model.

OBJECTIVE: To describe a novel percutaneous radiologic gastropexy (PRG) technique in a canine model and to biomechanically compare this technique to open incisional gastropexy (OIG) and laparoscopic-assisted incisional gastropexy (LAG). STUDY DESIGN: Randomized ex vivo biomechanical study. ANIMALS: Canine cadavers. METHODS: Fifteen cadavers were randomized to 1 of 3 surgical interventions: OIG, LAG, and PRG. For the PRG procedure, the stomach was distended with air, and a preloaded T-fastener device was utilized to attach the stomach to the body wall with fluoroscopic-guidance. The procedural times of the 3 techniques were recorded. After completion of the procedure, the stomach and body wall overlying the stomach wall were harvested and the maximum tensile strength of the gastropexies was determined. RESULTS: The maximal tensile strength was not significantly different between groups. The total procedural time for the PRG procedure (5 minutes) was significantly shorter than both OIG (28 minutes) and LAG (20 minutes) procedures. CONCLUSION: The PRG technique described in this study demonstrated a similar maximal tensile strength to commonly employed gastropexy techniques (OIG and LAG) in an acute canine model. Additionally, the PRG procedure was significantly faster to perform. The clinical relevance of this technique will be determined by further study to assess the applicability and efficacy of this procedure in clinical patients by determining the likelihood of adhesion development and the ability of the adhesion to prevent gastric volvulus.

A Randomized Phase II/III Study of Dalotuzumab in Combination With Cetuximab and Irinotecan in Chemorefractory, KRAS Wild-Type, Metastatic Colorectal Cancer.

BACKGROUND: Insulin-like growth factor type 1 receptor (IGF-1R) mediates resistance to epidermal growth factor receptor (EGFR) inhibition and may represent a therapeutic target. We conducted a multicenter, randomized, double blind, phase II/III trial of dalotuzumab, an anti-IGF-1R monoclonal antibody, with standard therapy in chemo-refractory, KRAS wild-type metastatic colorectal cancer. METHODS: Eligible patients were randomly assigned to dalotuzumab 10mg/kg weekly (arm A), dalotuzumab 7.5mg/kg every alternate week (arm B), or placebo (arm C) in combination with cetuximab and irinotecan. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Secondary endpoints included exploratory biomarker analyses. All statistical tests were two-sided. RESULTS: The trial was prematurely discontinued for futility after 344 eligible KRAS wild-type patients were included in the primary efficacy population (arm A = 116, arm B = 117, arm C = 111). Median PFS was 3.9 months in arm A (hazard ratio [HR] = 1.33, 95% confidence interval [CI] = 0.98 to 1.83, P = .07) and 5.4 months in arm B (HR = 1.13, 95% CI = 0.83 to 1.55, P = .44) compared with 5.6 months in arm C. Median OS was 10.8 months in arm A (HR = 1.41, 95% CI = 0.99 to 2.00, P = .06) and 11.6 months in arm B (HR = 1.26, 95% CI = 0.89 to 1.79, P = .18) compared with 14.0 months in arm C. Grade 3 or higher asthenia and hyperglycaemia occurred more frequently with dalotuzumab compared with placebo. In exploratory biomarker analyses, patients with high IGF-1 mRNA tumors in arm A had numerically better PFS (5.6 vs 3.6 months, HR = 0.59, 95% CI = 0.28 to 1.23, P = .16) and OS (17.9 vs 9.4 months, HR = 0.67, 95% CI = 0.31 to 1.45, P = .31) compared with those with high IGF-1 mRNA tumors in arm C. In contrast, in arm C high IGF-1 mRNA expression predicted lower response rate (17.6% vs 37.3%, P = .04), shorter PFS (3.6 vs 6.6 months, HR = 2.15, 95% CI = 1.15 to 4.02, P = .02), and shorter OS (9.4 vs 15.5 months, HR = 2.42, 95% CI = 1.21 to 4.82, P = .01). CONCLUSIONS: Adding dalotuzumab to irinotecan and cetuximab was feasible but did not improve survival outcome. IGF-1R ligands are promising biomarkers for differential response to anti-EGFR and anti-IGF-1R therapies.

A model of breast cancer heterogeneity reveals vascular mimicry as a driver of metastasis.

Cancer metastasis requires that primary tumour cells evolve the capacity to intravasate into the lymphatic system or vasculature, and extravasate into and colonize secondary sites. Others have demonstrated that individual cells within complex populations show heterogeneity in their capacity to form secondary lesions. Here we develop a polyclonal mouse model of breast tumour heterogeneity, and show that distinct clones within a mixed population display specialization, for example, dominating the primary tumour, contributing to metastatic populations, or showing tropism for entering the lymphatic or vasculature systems. We correlate these stable properties to distinct gene expression profiles. Those clones that efficiently enter the vasculature express two secreted proteins, Serpine2 and Slpi, which were necessary and sufficient to program these cells for vascular mimicry. Our data indicate that these proteins not only drive the formation of extravascular networks but also ensure their perfusion by acting as anticoagulants. We propose that vascular mimicry drives the ability of some breast tumour cells to contribute to distant metastases while simultaneously satisfying a critical need of the primary tumour to be fed by the vasculature. Enforced expression of SERPINE2 and SLPI in human breast cancer cell lines also programmed them for vascular mimicry, and SERPINE2 and SLPI were overexpressed preferentially in human patients that had lung-metastatic relapse. Thus, these two secreted proteins, and the phenotype they promote, may be broadly relevant as drivers of metastatic progression in human cancer.

A comparison of the somatometric measurements of adolescent males with and without idiopathic scoliosis.

STUDY DESIGN: Prospective study comparing the somatometric measurements of young males with normal spinal curves and with adolescent idiopathic scoliosis (AIS) with respect to the severity of AIS. OBJECTIVE: To assess the somatometric measurements of young males with normal spinal curves and with AIS using the conscription data. SUMMARY OF BACKGROUND DATA: The progression of AIS is closely correlated with longitudinal growth during puberty. Although abnormal growth in female AIS patients has been well investigated, the growth of male AIS patients has not been well reported. METHODS: During Korean conscription, 409 adolescent males with a normal spinal curvature and 420 adolescent males with AIS were enrolled. Those with AIS were grouped according to the severity of scoliosis using Cobb angles, according to the guidelines issued by the Korean military directorate. Group somatometric measurements, such as body height, corrected body height (corrected using Bjure's equation), body weight, and body mass index (BMI) were compared. RESULTS: Uncorrected heights were insignificantly different (P=0.234), but corrected heights, body weights, and BMIs were all significantly different between the normal and all AIS groups (P<0.001) (in AIS, corrected height was greater and body weight and BMIs corrected or uncorrected for height were lower). Cobb angles were not related to corrected body height or BMI, but was related to weight. Body weight was significantly less in the severe AIS group (Cobb angle >40 degrees) than in the mild or moderate AIS group (P<0.042). CONCLUSIONS: In Korean male AIS patients, significantly different somatometric results were observed: namely, a greater corrected height and a lower body weight and BMIs corrected or uncorrected for height. Furthermore, body weight was significantly lower in the severe group than in the moderate group. This study shows that abnormal growth is observed in male AIS patients and that body weight is closely correlated with AIS severity.

Hoof accelerations and ground reaction forces of Thoroughbred racehorses measured on dirt, synthetic, and turf track surfaces.

OBJECTIVE: To compare hoof acceleration and ground reaction force (GRF) data among dirt, synthetic, and turf surfaces in Thoroughbred racehorses. ANIMALS: 3 healthy Thoroughbred racehorses. PROCEDURES: Forelimb hoof accelerations and GRFs were measured with an accelerometer and a dynamometric horseshoe during trot and canter on dirt, synthetic, and turf track surfaces at a racecourse. Maxima, minima, temporal components, and a measure of vibration were extracted from the data. Acceleration and GRF variables were compared statistically among surfaces. RESULTS: The synthetic surface often had the lowest peak accelerations, mean vibration, and peak GRFs. Peak acceleration during hoof landing was significantly smaller for the synthetic surface (mean + or - SE, 28.5g + or - 2.9g) than for the turf surface (42.9g + or - 3.8g). Hoof vibrations during hoof landing for the synthetic surface were < 70% of those for the dirt and turf surfaces. Peak GRF for the synthetic surface (11.5 + or - 0.4 N/kg) was 83% and 71% of those for the dirt (13.8 + or - 0.3 N/kg) and turf surfaces (16.1 + or - 0.7 N/kg), respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The relatively low hoof accelerations, vibrations, and peak GRFs associated with the synthetic surface evaluated in the present study indicated that synthetic surfaces have potential for injury reduction in Thoroughbred racehorses. However, because of the unique material properties and different nature of individual dirt, synthetic, and turf racetrack surfaces, extending the results of this study to encompass all track surfaces should be done with caution.

N-hexanoyl chitosan stabilized magnetic nanoparticles: Implication for cellular labeling and magnetic resonance imaging.

This project involved the synthesis of N-hexanoyl chitosan or simply modified chitosan (MC) stabilized iron oxide nanoparticles (MC-IOPs) and the biological evaluation of MC-IOPs. IOPs containing MC were prepared using conventional methods, and the extent of cell uptake was evaluated using mouse macrophages cell line (RAW cells). MC-IOPs were found to rapidly associate with the RAW cells, and saturation was typically reached within the 24 h of incubation at 37 degrees C. Nearly 8.53 +/- 0.31 pg iron/cell were bound or internalized at saturation. From these results, we conclude that MC-IOPs effectively deliver into RAW cells in vitro and we also hope MC-IOPs can be used for MRI enhancing agents in biomedical fields.