In vivo micro–Computed Tomography (μCT) is commonly used tool in the study of mouse bone architecture. However, in vivo imaging of mouse cartilage has been limited. Intra-articular contrast injection ...was evaluated for its utility in detecting mouse cartilage in μCT. Clinically used iodinated contrast agent was chosen for its widespread commercial availability. Imaging protocol was developed with wild type C57BL/6 mice for its ability to detect expected cartilage thinning that occurs with sexual maturity. The protocol was then validated with transgenic mouse model with known extracellular matrix loss. μCT findings showed good correspondence with histological assessment. In conclusion, in vivo intra-articular contrast-enhanced μCT arthrography is viable technique for evaluation of mouse cartilage.
In vivo intra-articular contrast enhanced μCT of the mouse knee joint can delineate cartilage thickness and extracellular matrix content. The imaging protocol may be useful for longitudinal evaluation of cartilage anomalies in transgenicmouse model.
•The μCT arthrogram protocol was developed for imaging mouse knee cartilage.•The protocol can detect cartilage thinning with age in wild type growing mice.•The protocol can detect extracellular matrix loss in transgenic mice.
Disruptor of telomeric silencing 1-like (Dot1l) is a histone 3 lysine 79 methyltransferase. Studies of constitutive Dot1l knockout mice show that Dot1l is essential for embryonic development and ...prenatal hematopoiesis. DOT1L also interacts with translocation partners of Mixed Lineage Leukemia (MLL) gene, which is commonly translocated in human leukemia. However, the requirement of Dot1l in postnatal hematopoiesis and leukemogenesis of MLL translocation proteins has not been conclusively shown. With a conditional Dot1l knockout mouse model, we examined the consequences of Dot1l loss in postnatal hematopoiesis and MLL translocation leukemia. Deletion of Dot1l led to pancytopenia and failure of hematopoietic homeostasis, and Dot1l-deficient cells minimally reconstituted recipient bone marrow in competitive transplantation experiments. In addition, MLL-AF9 cells required Dot1l for oncogenic transformation, whereas cells with other leukemic oncogenes, such as Hoxa9/Meis1 and E2A-HLF, did not. These findings illustrate a crucial role of Dot1l in normal hematopoiesis and leukemogenesis of specific oncogenes.
Entrapment neuropathies of the ankle and foot pose a major diagnostic challenge and thus remain underdiagnosed. Recent advancements in imaging modalities, including magnetic resonance neurography ...(MRN), have resulted in considerable improvement in the anatomical localization and identification of pathologies leading to nerve entrapment. MRN supplements clinical examination and electrophysiologic studies in the diagnosis of neuropathies, aids in assessing disease severity, and helps formulate management strategies. A comprehensive understanding of the anatomy and imaging features of the ankle is essential to diagnose and manage entrapment neuropathies accurately. Advancements in imaging and their appropriate utilization will ultimately lead to better diagnoses and improved patient outcomes.
Massive periarticular calcinosis is poorly understood process arising either primarily (tumoral calcinosis) or secondary to underlying medical conditions, including connective tissue disease, soft ...tissue sarcoma, and metabolic dysregulation. The calcific deposits can cause functional limitation, skin ulceration, and cosmetic deformity. Treatment of the calcific deposits depends on the underlying cause but can be problematic with resistance to surgical and non-surgical treatments. Here, we introduce a case of tumoral calcinosis secondary to scleroderma treated with ultrasound guided aspiration.
•Massive periarticular calcinosis arises either primarily or secondary to underlying medical conditions.•Treatment options of calcinosis have varying success rates and there are treatment resistant cases and recurrences.•MRI and ultrasound imaging can open up ultrasound guided aspiration as a treatment option for these patients.
The MLL fusion proteins, AF9 and ENL, activate target genes in part via recruitment of the histone methyltransferase DOT1L (disruptor of telomeric silencing 1-like). Here we report biochemical, ...biophysical, and functional characterization of the interaction between DOT1L and MLL fusion proteins, AF9/ENL. The AF9/ENL-binding site in human DOT1L was mapped, and the interaction site was identified to a 10-amino acid region (DOT1L865-874). This region is highly conserved in DOT1L from a variety of species. Alanine scanning mutagenesis analysis shows that four conserved hydrophobic residues from the identified binding motif are essential for the interactions with AF9/ENL. Binding studies demonstrate that the entire intact C-terminal domain of AF9/ENL is required for optimal interaction with DOT1L. Functional studies show that the mapped AF9/ENL interacting site is essential for immortalization by MLL-AF9, indicating that DOT1L interaction with MLL-AF9 and its recruitment are required for transformation by MLL-AF9. These results strongly suggest that disruption of interaction between DOT1L and AF9/ENL is a promising therapeutic strategy with potentially fewer adverse effects than enzymatic inhibition of DOT1L for MLL fusion protein-associated leukemia.
Mucopolysaccharidosis I is a lysosomal storage disorder characterized by deficient alpha-L-iduronidase activity, leading to abnormal accumulation of glycosaminoglycans in cells and tissues. Synovial ...joint disease is prevalent and significantly reduces patient quality of life. There is a critical need for improved understanding of joint disease pathophysiology in MPS I, including specific biomarkers to predict and monitor joint disease progression, and response to treatment. The objective of this study was to leverage the naturally-occurring MPS I canine model and undertake an unbiased proteomic screen to identify systemic biomarkers predictive of local joint disease in MPS I. Synovial fluid and serum samples were collected from MPS I and healthy dogs at 12 months-of-age, and protein abundance characterized using liquid chromatography tandem mass spectrometry. Stifle joints were evaluated postmortem using magnetic resonance imaging (MRI) and histology. Proteomics identified 40 proteins for which abundance was significantly correlated between serum and synovial fluid, including markers of inflammatory joint disease and lysosomal dysfunction. Elevated expression of three biomarker candidates, matrix metalloproteinase 19, inter-alpha-trypsin inhibitor heavy-chain 3 and alpha-1-microglobulin, was confirmed in MPS I cartilage, and serum abundance of these molecules was found to correlate with MRI and histological degenerative grades. The candidate biomarkers identified have the potential to improve patient care by facilitating minimally-invasive, specific assessment of joint disease progression and response to therapeutic intervention.
•We identified 40 candidate serum biomarkers of joint disease in MPS I dogs.•Biomarkers correlated with joint condition assessed using MRI and histology.•Complement cascade-related pathways were implicated in joint disease etiology.•Biomarkers may enable minimally-invasive assessment of joint disease in patients.
Objectives
Stage IIIA non-small cell lung cancer (NSCLC) is heterogeneous in tumor burden, and its treatment is variable. Whole-body metabolic tumor volume (MTV
WB
) has been shown to be an ...independent prognostic index for overall survival (OS). However, the potential of MTV
WB
to risk-stratify stage IIIA NSCLC has previously been unknown. If we can identify subgroups within the stage exhibiting significant OS differences using MTV
WB
, MTV
WB
may lead to adjustments in patients’ risk profile evaluations and may, therefore, influence clinical decision making regarding treatment. We estimated the risk-stratifying capacity of MTV
WB
in stage IIIA by comparing OS of stratified stage IIIA with stage IIB and IIIB NSCLC.
Methods
We performed a retrospective review of 330 patients with clinical stage IIB, IIIA, and IIIB NSCLC diagnosed between 2004 and 2014. The patients’ clinical TNM stage, initial MTV
WB
, and long-term survival data were collected. Patients with TNM stage IIIA disease were stratified by MTV
WB
. The optimal MTV
WB
cutoff value for stage IIIA patients was calculated using sequential log-rank tests. Univariate and multivariate cox regression analyses and Kaplan-Meier OS analysis with log-rank tests were performed.
Results
The optimal MTV
WB
cut-point was 29.2 mL for the risk-stratification of stage IIIA. We identified statistically significant differences in OS between stage IIB and IIIA patients (
p
< 0.01), between IIIA and IIIB patients (
p
< 0.01), and between the stage IIIA patients with low MTV
WB
(below 29.2 mL) and the stage IIIA patients with high MTV
WB
(above 29.2 mL) (
p
< 0.01). There was no OS difference between the low MTV
WB
stage IIIA and the cohort of stage IIB patients (
p
= 0.485), or between the high MTV
WB
stage IIIA patients and the cohort of stage IIIB patients (
p
= 0.459). Similar risk-stratification capacity of MTV
WB
was observed in a large range of cutoff values from 15 to 55 mL in stage IIIA patients.
Conclusions
Using MTV
WB
cutoff points ranging from 15 to 55 mL with an optimal value of 29.2 mL, stage IIIA NSCLC may be effectively stratified into subgroups with no significant survival difference from stages IIB or IIIB NSCLC. This may result in more accurate survival estimation and more appropriate risk adapted treatment selection in stage IIIA NSCLC.
Mucopolysaccharidosis (MPS) VII is an inherited lysosomal storage disorder characterized by deficient activity of the enzyme β-glucuronidase. Skeletal abnormalities are common in patients and result ...in diminished quality of life. Enzyme replacement therapy (ERT) for MPS VII using recombinant human β-glucuronidase (vestronidase alfa) was recently approved for use in patients; however, to date there have been no studies evaluating therapeutic efficacy in a large animal model of MPS VII. The objective of this study was to establish the effects of intravenous ERT, administered at either the standard clinical dose (4 mg/kg) or a high dose (20 mg/kg), on skeletal disease progression in MPS VII using the naturally occurring canine model. Untreated MPS VII animals exhibited progressive synovial joint and vertebral bone disease and were no longer ambulatory by age 6 months. Standard-dose ERT-treated animals exhibited modest attenuation of joint disease, but by age 6 months were no longer ambulatory. High-dose ERT-treated animals exhibited marked attenuation of joint disease, and all were still ambulatory by age 6 months. Vertebral bone disease was recalcitrant to ERT irrespective of dose. Overall, our findings indicate that ERT administered at higher doses results in significantly improved skeletal disease outcomes in MPS VII dogs.
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Mucopolysaccharidosis (MPS) VII patients exhibit severe skeletal abnormalities leading to diminished quality of life. In this study, Smith, Casal, and colleagues undertook the first evaluation of enzyme replacement therapy (ERT) in a large animal model of MPS VII. Higher doses of ERT attenuated synovial joint disease progression and preserved mobility.
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