Spinal calcifying pseudoneoplasm of the neuraxis (CAPNON) associated with facet joint pathologies: CAPNON diagnostic and pathogenic insights.

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumor-like fibro-osseous lesion that can develop anywhere in the neuraxis. Approximately a half of reported CAPNONs developed in the spinal region, mostly close to the facet joint (FJ). The diagnosis of spinal CAPNONs is challenging given the existence of mimics and associated pathologies including calcific degeneration of the FJ ligaments (DFJL) and synovial cysts (SCs). The pathogenesis of CAPNON remains elusive, although there have been a few hypotheses including degenerative, reactive, proliferative and immune-mediated processes. Our present study examined clinical, radiological and pathological features of 12 spinal CAPNONs in comparison to 9 DFJL foci, and diagnostic and pathogenic relationship between CAPNONs and FJ pathologies. On imaging, CAPNONs were all tumor-like and typically bigger than DFJL foci. All CAPNONs showed pathologically diagnostic features including characteristic cores, consistently identifiable core-surrounding/peripheral palisading of macrophages and other cells including multinucleated giant cells, variable infiltration of CD8+ T-cells, and multifocal immunopositivity of neurofilament light chain (NF-L). These features were absent or limited in the DFJL foci with statistically significant differences from CAPNONs, except calcifications. Spinal CAPNONs co-existed with DFJL foci in all cases; some had transitional foci with overlapping focal CAPNON and DFJL-like features. These findings, along with our previously reported relationship between CAPNONs and SCs, suggest that spinal CAPNONs may occur in association with or in transition from calcifying/calcified degenerative lesions of FJ ligaments and/or SCs when a reactive proliferative process is complemented by other pathogenic changes such as immune-mediated pathology and NF-L deposition/expression.

Cylindrical spirals and other concentric structures of skeletal muscle in patients with neurological diseases.

Cylindrical spirals (CSs) are ultrastructurally distinct, intracytoplasmic inclusions characterized by concentrically wrapped lamellae, which are rarely found in skeletal muscle biopsies on electron microscopy (EM). CSs are often confused with other EM concentric structures including concentric laminated bodies and mitochondrial concentric cristae (MCC), due to similarities in these ultrastructures. In this study, we found CSs in 9 muscle biopsies from 9 patients, accounting for 0.5% of the biopsies examined routinely by EM. The frequency of CSs in these muscles varied from sparse and segregated to focally frequent and aggregated. CS-associated features included muscle fiber denervation atrophy in all 9 cases, fiber type grouping in 7/8 cases, tubular aggregates in 3/9 cases, and MCC in 2/9 cases. We also compared the concentric structures and highlighted their differences to distinguish CSs from other similar structures. Clinically, 8 out of 9 patients were adults aged 41-74 years and only one patient was 17 month-old. CSs were associated with several neurological diseases including Huntington's disease, amyotrophic lateral sclerosis, Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-like episodes, and other complex neurological disorders with neuropathy/encephalopathy, as well as anti-MDA5+ dermatomyositis. Eight of nine patients had genetic findings such as trinucleotide repeat expansion of huntingtin gene, ALS2 variant, MT-TL1 m.3243A > G mutation, and PMP 22 gene deletion. These results suggest that CSs may be highly variable in frequency and likely are under-reported/under-detected; they may be associated with neurogenic myopathy or central/peripheral nervous system disorders including some genetic neurological/neuromuscular diseases. Our findings of more CS-associated neurological diseases and an association of CSs with muscle neurogenic features may contribute to a better understanding of the clinico-pathological significance of CSs.

Syngeneic mouse model of human HER2+ metastatic breast cancer for the evaluation of trastuzumab emtansine combined with oncolytic rhabdovirus.

Background: Established mouse models of HER2+ cancer are based on the over-expression of rodent Neu/Erbb2 homologues, which are incompatible with human HER2 (huHER2) targeted therapeutics. Additionally, the use of immune-deficient xenograft or transgenic models precludes assessment of native anti-tumour immune responses. These hurdles have been a challenge for our understanding of the immune mechanisms behind huHER2-targeting immunotherapies. Methods: To assess the immune impacts of our huHER2-targeted combination strategy, we generated a syngeneic mouse model of huHER2+ breast cancer, using a truncated form of huHER2, HER2T. Following validation of this model, we next treated tumour-bearing with our immunotherapy strategy: oncolytic vesicular stomatitis virus (VSVΔ51) with clinically approved antibody-drug conjugate targeting huHER2, trastuzumab emtansine (T-DM1). We assessed efficacy through tumour control, survival, and immune analyses. Results: The generated truncated HER2T construct was non-immunogenic in wildtype BALB/c mice upon expression in murine mammary carcinoma 4T1.2 cells. Treatment of 4T1.2-HER2T tumours with VSVΔ51+T-DM1 yielded robust curative efficacy compared to controls, and broad immunologic memory. Interrogation of anti-tumour immunity revealed tumour infiltration by CD4+ T cells, and activation of B, NK, and dendritic cell responses, as well as tumour-reactive serum IgG. Conclusions: The 4T1.2-HER2T model was used to evaluate the anti-tumour immune responses following our complex pharmacoviral treatment strategy. These data demonstrate utility of the syngeneic HER2T model for assessment of huHER2-targeted therapies in an immune-competent in vivo setting. We further demonstrated that HER2T can be implemented in multiple other syngeneic tumour models, including but not limited to colorectal and ovarian models. These data also suggest that the HER2T platform may be used to assess a range of surface-HER2T targeting approaches, such as CAR-T, T-cell engagers, antibodies, or even retargeted oncolytic viruses.

Rheumatoid nodules: a narrative review of histopathological progression and diagnostic consideration.

Rheumatoid nodules (RNs) are the most common extra-articular manifestation of rheumatoid arthritis and are also seen in patients with other autoimmune and inflammatory diseases. The development of RNs includes histopathological stages of acute unspecified inflammation, granulomatous inflammation with no or minimal necrosis, necrobiotic granulomas typically with central fibrinoid necrosis surrounded by palisading epithelioid macrophages and other cells, and likely an advanced stage of "ghost" lesions containing cystic or calcifying/calcified areas. In this article, we review RN pathogenesis, histopathological features in different stages, diagnostically related clinical manifestations, as well as diagnosis and differential diagnosis of RNs with an in-depth discussion about challenges in distinguishing RNs from their mimics. While the pathogenesis of RN formation remains elusive, it is hypothesized that some RNs with dystrophic calcification may be in transition and may be in coexistence or collision with another lesion in patients with RA or other soft tissue diseases and comorbidities. The diagnosis of typical or mature RNs in usual locations can be readily made by clinical findings often with classic RN histopathology, but in many cases, particularly with atypical or immature RNs and/or unusual locations, the clinical and histopathological diagnosis can be challenging requiring extensive examination of the lesional tissue with histological and immunohistochemical markers to identify unusual RNs in the clinical context or other lesions that may be coexisting with classic RNs. Proper diagnosis of RNs is critical for appropriate treatment of patients with RA or other autoimmune and inflammatory diseases.

Lymphomas in patients with neurofibromatosis type 1 (NF1): another malignancy in the NF1 syndrome?

Neurofibromatosis type 1 (NF1) is an autosomal dominant multisystem syndrome caused by mutations in the neurofibromin 1 (NF1) gene that encodes for the protein neurofibromin acting as a tumour suppressor. Neurofibromin functions primarily as a GTPase-activating protein for the Ras family of oncogenes, which activates many signalling pathways for cell proliferation and differentiation; without neurofibromin, Ras is constitutively activated, thereby turning on many downstream signalling pathways related to oncogenesis. Patients with NF1 have a well known predisposition for certain types of malignancies including malignant peripheral nerve sheath tumours, gliomas, and breast cancers, as well as a potential association of NF1 with lymphoproliferative disorders such as lymphomas. In this article, we review the pathophysiology and tumourigenesis of NF1, previously reported cases of cutaneous lymphomas in NF1 patients along with our case demonstration of a NF1-associated scalp B-cell lymphoma, and NF1-associated extra cutaneous lymphomas. The diagnosis of lymphomas particularly cutaneous lymphomas may be difficult in NF1 patients as they often have skin lesions and/or cutaneous/subcutaneous nodules or tumours like neurofibromas, which raises the possibility of underdiagnosed cutaneous lymphomas in NF1 patients. We also comprehensively discuss the association between NF1 and lymphomas. In summary, most studies support a potential association between NF1 and lymphomas. Further investigation is needed to clarify the association between NF1 and lymphomas in order to bring clinical awareness of possibly underdiagnosed NF1-associated lymphomas and individualised management of NF1 patients to practice.

A dataset of simulated patient-physician medical interviews with a focus on respiratory cases.

Artificial Intelligence (AI) is playing a major role in medical education, diagnosis, and outbreak detection through Natural Language Processing (NLP), machine learning models and deep learning tools. However, in order to train AI to facilitate these medical fields, well-documented and accurate medical conversations are needed. The dataset presented covers a series of medical conversations in the format of Objective Structured Clinical Examinations (OSCE), with a focus on respiratory cases in audio format and corresponding text documents. These cases were simulated, recorded, transcribed, and manually corrected with the underlying aim of providing a comprehensive set of medical conversation data to the academic and industry community. Potential applications include speech recognition detection for speech-to-text errors, training NLP models to extract symptoms, detecting diseases, or for educational purposes, including training an avatar to converse with healthcare professional students as a standardized patient during clinical examinations. The application opportunities for the presented dataset are vast, given that this calibre of data is difficult to access and costly to develop.

Impact of ethnicity on mood disorders in Parkinson's disease.

Anxiety and depression are common in Parkinson's disease (PD) patients, yet their prevalence and severity compared to individuals without PD requires more research. Moreover, it has never been compared across different ethnic groups. The objective of this study was to close that gap in the literature by exploring the caseness and severity of anxiety and depression in PD patients of different ethnicities compared to controls without PD. It was found that caseness and severity of anxiety and depression are higher in individuals with PD compared to controls. Furthermore, the caseness and severity of anxiety and depression do not vary significantly among ethnic groups. Finally, depression caseness was not predicted by age, gender, disease duration, restless legs syndrome prevalence, Hoehn and Yahr (H&Y) score nor Unified Parkinson's disease rating scale part III (UPDRS-III) score. Anxiety caseness was predicted by gender, with females 2.7 times more likely to have anxiety caseness than males. Overall, our study suggests that treatment plans should be individualized based on prevalence and severity of the two conditions in individuals with PD rather than generalize treatment for specific ethnic groups.