Spindle cell neoplasms with novel LTK fusion - Expanding the spectrum of kinase fusion-positive soft tissue tumors.

AIMS: Kinase fusion-positive soft tissue tumors represent an emerging, molecularly defined group of mesenchymal tumors with a wide morphologic spectrum and diverse activating kinases. Here, we present two cases of soft tissue tumors with novel LTK fusions. METHODS AND RESULTS: Both cases presented as acral skin nodules (big toe and middle finger) in pediatric patients (17-year-old girl and 2-year-old boy). The tumors measured 2 and 3 cm in greatest dimension. Histologically, both cases exhibited bland-looking spindle cells infiltrating adipose tissue and accompanied by collagenous stroma. One case additionally displayed perivascular hyalinization and band-like stromal collagen. Both cases exhibited focal S100 staining, and one case had patchy coexpression of CD34. Targeted RNA-seq revealed the presence of novel in-frame MYH9::LTK and MYH10::LTK fusions, resulting in upregulation of LTK expression. Of interest, DNA methylation-based unsupervised clustering analysis in one case showed that the tumor clustered with dermatofibrosarcoma protuberans (DFSP). One tumor was excised with amputation with no local recurrence or distant metastasis at 18-month follow-up. The other case was initially marginally excised with local recurrence after one year, followed by wide local excision, with no evidence of disease at 10 years of follow-up. CONCLUSIONS: This is the first reported case series of soft tissue tumors harboring LTK fusion, expanding the molecular landscape of soft tissue tumors driven by activating kinase fusions. Furthermore, studies involving a larger number of cases and integrated genomic analyses will be warranted to fully elucidate the pathogenesis and classification of these tumors.

A ribose-functionalized NAD+ with versatile activity for ADP-ribosylation.

An NAD+ featuring an adenosyl 4'-azido functions as a general substrate for poly-ADP-ribose polymerases. Its derived mono- and poly-ADP-ribosylated proteins can be adequately recognized by distinct ADP-ribosylation-specific readers. This molecule represents the first ribose-functionalized NAD+ with versatile activities across different ADP-ribosyltransferases and provides insight into developing new probes for ADP-ribosylation.

Effectiveness of population-based colorectal cancer screening programme in down-staging.

BACKGROUND: This is the first evaluation study to assess the demographic characteristics of the colorectal cancer (CRC) cases detected in the prevalent round of the population-based Colorectal Cancer Screening Programme (CRCSP) in Hong Kong and to explore the effectiveness of the programme on the stage distribution of CRC. METHODS: This study covered the period between 28 September 2016 and 31 December 2018. Information on CRC diagnosis, age and stage at diagnosis were retrieved and reviewed by the Hong Kong Cancer Registry (HKCaR). The CRC detection rate among CRCSP-screened participants and incidence rate among the Hong Kong general population were calculated respectively. The odds ratio (OR) was calculated to measure the strength of association and quantify the effect of CRCSP on stage shift between CRCSP-detected CRC cases and an age-matched cohort of CRC cases diagnosed outside the programme. RESULTS: The CRC detection rate among participants of the CRCSP during the study period was 736.0/100,000, whereas the overall CRC incidence rate among general population of similar age groups was 393.7/100,000. For all ages and both sexes, the OR of stage I CRCSP-detected CRC compared to the CRC from the age-matched cohort was 3.91 (95%CI=3.41-4.48) and the OR dropped to 0.54 (95%CI=0.41-0.70) at stage IV. Meanwhile, the overall OR of CRCSP-detected CRC compared to CRC from the age-matched cohort dropped from 2.24 (95%CI=1.97-2.56) to 1.62 (95%CI=1.40-1.87) with increasing age. CONCLUSION: The present study has demonstrated the initial impact of the CRCSP on shifting the stage at diagnosis towards earlier stage. The benefit of stage-shift was similar for all ages from 60 to 77 in both sexes and seems to increase with younger age. Given the stage-dependent survival outcomes, this stage-shift could lead to a reduction in CRC-associated mortality in Hong Kong in future.

Discovery of an NAD+ analogue with enhanced specificity for PARP1.

Among various protein posttranslational modifiers, poly-ADP-ribose polymerase 1 (PARP1) is a key player for regulating numerous cellular processes and events through enzymatic attachments of target proteins with ADP-ribose units donated by nicotinamide adenine dinucleotide (NAD+). Human PARP1 is involved in the pathogenesis and progression of many diseases. PARP1 inhibitors have received approvals for cancer treatment. Despite these successes, our understanding about PARP1 remains limited, partially due to the presence of various ADP-ribosylation reactions catalyzed by other PARPs and their overlapped cellular functions. Here we report a synthetic NAD+ featuring an adenosyl 3'-azido substitution. Acting as an ADP-ribose donor with high activity and specificity for human PARP1, this compound enables labelling and profiling of possible protein substrates of endogenous PARP1. It provides a unique and valuable tool for studying PARP1 in biology and pathology and may shed light on the development of PARP isoform-specific modulators.

Novel MAP4::RAF1 Fusion in a Primary Bone Sarcoma: Expanding the spectrum of RAF1 Fusion Sarcoma.

Soft tissue tumors with RAF1 fusion had been emerging as a group of tumors with peculiar histology and immunoprofile. While a case series and rare case reports of RAF1 translocated sarcoma had been reported, to our knowledge a primary bone tumor with RAF1 translocation and fusion partner with MAP4 had not been described in the literature. The patient was a 60-year-old lady, with strong family history of breast cancer, who presented with pathological fracture of right humerus. X-ray revealed a 9.7 cm juxta-articular lesion of the proximal humerus, which was expansile and lytic with a non-sclerotic well defined border distally, radiologically suggestive of a giant cell tumor of bone. Excision was performed after initial biopsy. Histology showed a monomorphic low grade spindle cell lesion with prominent hyalinized stroma. Immunohistochemistry demonstrated diffuse CD34 staining, with focal staining for S100. Gene sequencing for histone 3 H3 genes was negative for hotspot mutation. Targeted RNA-seq sequencing revealed the presence of MAP4::RAF1 fusion, which was confirmed by reverse transcriptase-polymerase chain reaction (RT-PCR) and fluorescence in-situ hybridization (FISH) break-apart probes involving both genes. The overall features were consistent with a primary bone sarcoma with RAF1 fusion. This report expanded the spectrum of RAF1 fusion sarcoma and was the first report documenting its primary occurrence in bone.

A Collaborative Classroom Investigation of the Evolution of SABATH Methyltransferase Substrate Preference Shifts over 120 My of Flowering Plant History.

Next-generation sequencing has resulted in an explosion of available data, much of which remains unstudied in terms of biochemical function; yet, experimental characterization of these sequences has the potential to provide unprecedented insight into the evolution of enzyme activity. One way to make inroads into the experimental study of the voluminous data available is to engage students by integrating teaching and research in a college classroom such that eventually hundreds or thousands of enzymes may be characterized. In this study, we capitalize on this potential to focus on SABATH methyltransferase enzymes that have been shown to methylate the important plant hormone, salicylic acid (SA), to form methyl salicylate. We analyze data from 76 enzymes of flowering plant species in 23 orders and 41 families to investigate how widely conserved substrate preference is for SA methyltransferase orthologs. We find a high degree of conservation of substrate preference for SA over the structurally similar metabolite, benzoic acid, with recent switches that appear to be associated with gene duplication and at least three cases of functional compensation by paralogous enzymes. The presence of Met in active site position 150 is a useful predictor of SA methylation preference in SABATH methyltransferases but enzymes with other residues in the homologous position show the same substrate preference. Although our dense and systematic sampling of SABATH enzymes across angiosperms has revealed novel insights, this is merely the "tip of the iceberg" since thousands of sequences remain uncharacterized in this enzyme family alone.

Case report on metastatic pelvic bone tumor treated with frozen autograft by liquid nitrogen.

INTRODUCTION AND IMPORTANCE: Frozen autograft recycling has been used for biological reconstruction of bone defects following tumor excision, more commonly in extremities. We report on the histological outcome of a pelvic recycled frozen autograft. CASE PRESENTATION: We investigated the pelvic frozen autograft removed in 2 years and 8 months after surgery because of soft tissue recurrence in pelvic floor. The autograft bone showed no evidence of revitalization and was non-viable with patchy inflammation, and no residual tumor. There was only fibrous union but the autograft bone remained mechanically stable. CLINICAL DISCUSSION: We confirmed the clearance of tumor cells with the treatment with liquid nitrogen. The union at the host-graft junction might be affected by the previous radiotherapy, the presence of infection, the small contact area limited by the anatomy, and the inadequate compression across the osteotomy interface with the fixation. CONCLUSION: Frozen autograft treated by liquid nitrogen can be used safely for biological reconstructions after pelvic tumor excision.

A Bifunctional NAD+ for Profiling Poly-ADP-Ribosylation-Dependent Interacting Proteins.

Protein poly-ADP-ribosylation (PARylation) is a heterogeneous and dynamic post-translational modification regulated by various writers, readers, and erasers. It participates in a variety of biological events and is involved in many human diseases. Currently, tools and technologies have yet to be developed for unambiguously defining readers and erasers of individual PARylated proteins or cognate PARylated proteins for known readers and erasers. Here, we report the generation of a bifunctional nicotinamide adenine dinucleotide (NAD+) characterized by diazirine-modified adenine and clickable ribose. By serving as an excellent substrate for poly-ADP-ribose polymerase 1 (PARP1)-catalyzed PARylation, the generated bifunctional NAD+ enables photo-cross-linking and enrichment of PARylation-dependent interacting proteins for proteomic identification. This bifunctional NAD+ provides an important tool for mapping cellular interaction networks centered on protein PARylation, which are essential for elucidating the roles of PARylation-based signals or activities in physiological and pathophysiological processes.

Surgeon Performed Ultrasound for Diagnosis of Intussusception - A Pilot Study.

Aim: To study the diagnostic accuracy of surgeon performed ultrasound (SPU) in the diagnosis of children presenting with clinical suspicion of intussusception to a tertiary paediatric facility in NSW, Australia. Methods: Children under the age of 16 presenting to the emergency department with clinical features suggestive of intussusception were recruited. After obtaining consent SPU was performed by a Paediatric surgeon. All patients subsequently had an ultrasound performed in radiology department (RPU) on which management was based. Diagnosis and images of SPU were reviewed by an independent radiologist blinded to results of the formal study. Results: Of 7 children enrolled 5 were male. Age ranged from 3 months to 7 years (mean 2.64, SD 2.282), weight from 5.2kgs to 25.2kgs (mean 13.69, SD 6.721). Five out of the 7 children presented during day hours i.e. 8a.m.-5 p.m. (mean 12.72, SD 4.049). Mean time to SPU was 6.3 hours (SD7.1) and RPU was 8.3 hours (SD 7.6). SPU was earlier by 2 hours and correlation between SPU and RPU was 100 percent. Conclusion: SPU for intussusception can be performed early and accurately. Surgeons should train and use ultrasound as a reliable tool in evaluating the child with suspected intussusception.

Disturbance-Aware Neuro-Optimal System Control Using Generative Adversarial Control Networks.

Disturbance, which is generally unknown to the controller, is unavoidable in real-world systems and it may affect the expected system state and output. Existing control methods, like robust model predictive control, can produce robust solutions to maintain the system stability. However, these robust methods trade the solution optimality for stability. In this article, a method called generative adversarial control networks (GACNs) is proposed to train a controller via demonstrations of the optimal controller. By formulating the optimal control problem in the presence of disturbance, the controller trained by GACNs obtains neuro-optimal solutions without knowing the future disturbance and determines the objective function explicitly. A joint loss, composed of the adversarial loss and the least square loss, is designed to be used in the training of the generator. Experimental results on simulated systems with disturbance show that GACNs outperform other compared control methods.

A child with acute myeloid leukemia complicated by calcaneal osteomyelitis due to Mycobacterium abscessus infection after induction chemotherapy successfully salvaged with bedaquiline and clofazimine.

Our patient was a 4-year-old female with acute myeloid leukemia complicated with right calcaneal osteomyelitis due to Mycobacterium abscessus with subcutaneous abscesses extending to the popliteal and groin regions after two courses of induction chemotherapy according to NOPHO-AML 2012 protocol. She required multiple operations and prolonged anti-mycobacterial therapy. A high index of suspicion for mycobacterial infection is required for immunocompromised patients with prolonged fever or unusual presentation. Mycobacterial osteomyelitis is rare, difficult to diagnose and treat, and may necessitate prolonged interruption of anti-leukemic therapy. Multidisciplinary collaboration in patient management is crucial. Long-term toxicity of antimicrobials with uncertain efficacy should not be overlooked.

Anti-FLT3 nanoparticles for acute myeloid leukemia: Preclinical pharmacology and pharmacokinetics.

FLT3 receptor is an important therapeutic target in acute myeloid leukemia due to high incidence of mutations associated with poor clinical outcome. Targeted therapies against the FLT3 receptor, including small-molecule FLT3 tyrosine kinase inhibitors (TKIs) and anti-FLT3 antibodies, have demonstrated promising preclinical and even clinical efficacy. Yet, even with the current FDA approval for two FLT3 inhibitors, these modalities were unable to cure AML or significantly extend the lives of patients with a common mutation called FLT3-ITD. While FLT3 is a viable target, the approaches to inhibit its activity were inadequate. To develop a new modality for targeting FLT3, our team engineered an α-FLT3-A192 fusion protein composed of a single chain variable fragment antibody conjugated with an elastin-like polypeptide. These fusion proteins assemble into multi-valent nanoparticles with excellent stability and pharmacokinetic properties as well as in vitro and in vivo pharmacological activity in cellular and xenograft murine models of AML. In conclusion, α-FLT3-A192 fusions appear to be a viable new modality for targeting FLT3 in AML and warrant further preclinical development to bring it into the clinic.

Transfer of the anterior gluteus maximus to address abductor deficiency following soft tissue tumour excision.

Hip abductor deficiency is most commonly encountered in the context of degeneration of the hip, and techniques for reconstruction pioneered by arthroplasty surgeons. We adopted a local muscle transfer technique utilizing the anterior half of the gluteus maximus for abductor reconstruction following soft tissue tumour excision in a young female patient. The patient of concern had a solitary fibrous tumour located between the right gluteus medius and minimus detected as an incidental finding. Marginal excision of the mass resulted in removal of the gluteus medius. The anterior half of the gluteus maximus was transferred and attached to the decorticated lateral greater trochanter by means of suture anchors and transosseous sutures. The patient initially demonstrated a Trendelenburg gait and limited abduction against gravity. By 1-year post-operation, there was return of normal gait and recovery of hip abductor power. This is the first report of anterior gluteus maximus transfer being successfully applied for soft tissue reconstruction around the hip subsequent to tumour excision.

A ribose-functionalized NAD+ with unexpected high activity and selectivity for protein poly-ADP-ribosylation.

Nicotinamide adenine dinucleotide (NAD+)-dependent ADP-ribosylation plays important roles in physiology and pathophysiology. It has been challenging to study this key type of enzymatic post-translational modification in particular for protein poly-ADP-ribosylation (PARylation). Here we explore chemical and chemoenzymatic synthesis of NAD+ analogues with ribose functionalized by terminal alkyne and azido groups. Our results demonstrate that azido substitution at 3'-OH of nicotinamide riboside enables enzymatic synthesis of an NAD+ analogue with high efficiency and yields. Notably, the generated 3'-azido NAD+ exhibits unexpected high activity and specificity for protein PARylation catalyzed by human poly-ADP-ribose polymerase 1 (PARP1) and PARP2. And its derived poly-ADP-ribose polymers show increased resistance to human poly(ADP-ribose) glycohydrolase-mediated degradation. These unique properties lead to enhanced labeling of protein PARylation by 3'-azido NAD+ in the cellular contexts and facilitate direct visualization and labeling of mitochondrial protein PARylation. The 3'-azido NAD+ provides an important tool for studying cellular PARylation.

Diagnostic accuracy of surgeon performed ultrasound (SPU) for appendicitis in children.

AIM: Compare the diagnostic accuracy of surgeon performed ultrasound to radiology performed ultrasound in children presenting with suspected appendicitis to a tertiary care pediatric hospital in Australia. METHODS: Children under 16 presenting to the emergency department of The Children's Hospital at Westmead were considered for the study. Patients with obvious signs of appendicitis not requiring ultrasound and those with established ultrasound diagnosis of appendicitis were excluded. Ultrasound was performed by a Pediatric Surgeon (SPU) after obtaining consent. The treating team was blinded to the results. Patient underwent formal ultrasound in radiology (RPU) and treatment was based on the formal report. SPU result was reviewed by a radiologist blinded to results of RPU. The results were compared. RESULTS: 65 children underwent ultrasound. 35 were male. Median age was 10 (range3-15). Median weight was 36 kg (range 12.6-76.2 kg), z-score median 0.21 (-1.83 to 2.74). Symptom duration ranged from few hours to 2 weeks but majority (45) had symptoms for less than 48 h. Prevalence of appendicitis was 45%. Thirty two underwent surgery. Negative appendicectomy rate was 9.4%. Thirty three did not have surgery. 8 represented but only one proceeded to appendicectomy. SPU was done earlier than RPU (median 12 h vs 14.15 h) p = 0.088. Diagnostic accuracy using ROC did not reveal significant difference. CONCLUSION: SPU can be performed earlier than RPU with reliable accuracy. Training surgical trainees will enable early diagnosis and management of appendicitis.

A macrodomain-linked immunosorbent assay (MLISA) for mono-ADP-ribosyltransferases.

ADP-ribosyltransferases (ARTs) catalyze reversible additions of mono- and poly-ADP-ribose onto diverse types of proteins by using nicotinamide adenine dinucleotide (NAD+) as a cosubstrate. In the human ART superfamily, 14 out of 20 members are shown to catalyze endogenous protein mono-ADP-ribosylation and play important roles in regulating various physiological and pathophysiological processes. Identification of new modulators of mono-ARTs can thus potentially lead to discovery of novel therapeutics. In this study, we developed a macrodomain-linked immunosorbent assay (MLISA) for characterizing mono-ARTs. Recombinant macrodomain 2 from poly-ADP-ribose polymerase 14 (PARP14) was generated with a C-terminal human influenza hemagglutinin (HA) tag for detecting mono-ADP-ribosylated proteins. Coupled with an anti-HA secondary antibody, the generated HA-tagged macrodomain 2 reveals high specificity for mono-ADP-ribosylation catalyzed by distinct mono-ARTs. Kinetic parameters of PARP15-catalyzed automodification were determined by MLISA and are in good agreement with previous studies. Eight commonly used chemical tools for PARPs were examined by MLISA with PARP15 and PARP14 in 96-well plates and exhibited moderate inhibitory activities for PARP15, consistent with published reports. These results demonstrate that MLISA provides a new and convenient method for quantitative characterization of mono-ART enzymes and may allow identification of potent mono-ART inhibitors in a high-throughput-compatible manner.

Paraprotein-Related Kidney Disease: Glomerular Diseases Associated with Paraproteinemias.

Paraproteins are monoclonal Igs that accumulate in blood as a result of abnormal excess production. These circulating proteins cause a diversity of kidney disorders that are increasingly being comanaged by nephrologists. In this review, we discuss paraprotein-related diseases that affect the glomerulus. We provide a broad overview of diseases characterized by nonorganized deposits, such as monoclonal Ig deposition disease (MIDD), proliferative GN with monoclonal Ig deposits (PGNMID), and C3 glomerulopathy, as well as those characterized by organized deposits, such as amyloidosis, immunotactoid glomerulopathy, fibrillary GN, and cryoglobulinemic GN, and rarer disorders, such as monoclonal crystalline glomerulopathies, paraprotein-related thrombotic microangiopathies, and membranous-like glomerulopathy with masked IgGκ deposits. This review will provide the nephrologist with an up to date understanding of these entities and highlight the areas of deficit in evidence and future lines of research.

Giant cell tumor of the humeral head treated by denosumab: Implication to shoulder surgeons.

Giant cell tumor is a benign bone tumor that is commonly encountered. The optimal treatment of a giant cell tumor which causes extensive bony destruction is controversial. Recent studies on the receptor activator of nuclear factor κB ligand antagonist denosumab may offer a new treatment option for these patients. We presented a patient with giant cell tumor of the humeral head. He was initially treated with denosumab and subsequently with the operation. The shoulder joint was successfully salvaged. But there are potential difficulties that surgeons may face in patients treated with denosumab.