Current situation of osteogenesis imperfecta in Spain: results from a Delphi study.

BACKGROUND: Osteogenesis imperfecta (OI) is a rare disease characterized by low bone mass and bone fragility, associated with an increased risk of fractures, and skeletal and extra-skeletal symptoms that results in an impairment of health-related quality of life of OI patients. Since published studies on OI in Spain are limited, this study aimed to determine the epidemiology, assessed the disease burden, management and unmet needs of OI patients in Spain. Thirty-four experts in the management of patients with osteogenesis imperfecta completed two rounds of online consultation and reported real-life experience and data from Spanish hospitals. Delphi study questionnaires were based on literature review. A working group of nationally recognized clinical experts supported the development of the study questionnaires and the final validation of results. RESULTS: The estimated prevalence of patients diagnosed with OI in Spain is 0.56:10,000 inhabitants (95%CI: 0.54-0.59), which represents that, approximately, 2,669 OI patients are currently managed in Spanish hospitals. It is estimated that approximately 269 new patients would be diagnosed with OI each year in Spain, representing an estimated incidence of 0.06 (95%CI: 0.05-0.06) per 10,000 inhabitants per year. Clinical management of OI in Spain is performed by a range of medical specialists; however, multidisciplinary care is not fully implemented. The absence of an approved curative treatment or a treatment to reduce the clinical features of the disease remains the main unmet need. CONCLUSIONS: This study provides a snapshot of the current situation of patients with OI in Spain reported by clinical experts. The results provide an estimation of the epidemiology of the disease, and complement the available evidence on disease burden, clinical management, and unmet needs of these patients in Spain.

The patient clinical journey and socioeconomic impact of osteogenesis imperfecta: a systematic scoping review.

BACKGROUND: Osteogenesis imperfecta (OI) is a rare heritable connective tissue disorder primarily characterised by skeletal deformity and fragility, and an array of secondary features. The purpose of this review was to capture and quantify the published evidence relating specifically to the clinical, humanistic, and economic impact of OI on individuals, their families, and wider society. METHODS: A systematic scoping review of 11 databases (MEDLINE, MEDLINE in-progress, EMBASE, CENTRAL, PsycINFO, NHS EED, CEA Registry, PEDE, ScHARRHUd, Orphanet and Google Scholar), supplemented by hand searches of grey literature, was conducted to identify OI literature published 1st January 1995-18th December 2021. Searches were restricted to English language but without geographical limitations. The quality of included records was assessed using the AGREE II checklist and an adapted version of the JBI cross-sectional study checklist. RESULTS: Of the identified 7,850 records, 271 records of 245 unique studies met the inclusion criteria; overall, 168 included records examined clinical aspects of OI, 67 provided humanistic data, 6 reported on the economic impact of OI, and 30 provided data on mixed outcomes. Bone conditions, anthropometric measurements, oral conditions, diagnostic techniques, use of pharmacotherapy, and physical functioning of adults and children with OI were well described. However, few records included current care practice, diagnosis and monitoring, interactions with the healthcare system, or transition of care across life stages. Limited data on wider health concerns beyond bone health, how these concerns may impact health-related quality of life, in particular that of adult men and other family members, were identified. Few records described fatigue in children or adults. Markedly few records provided data on the socioeconomic impact of OI on patients and their caregivers, and associated costs to healthcare systems, and wider society. Most included records had qualitative limitations. CONCLUSION: Despite the rarity of OI, the volume of recently published literature highlights the breadth of interest in the OI field from the research community. However, significant data gaps describing the experience of OI for individuals, their families, and wider society warrant further research to capture and quantify the full impact of OI.

Tumor-Derived Extracellular Vesicles: Multifunctional Entities in the Tumor Microenvironment.

Tumor cells release extracellular vesicles (EVs) that can function as mediators of intercellular communication in the tumor microenvironment. EVs contain a host of bioactive cargo, including membrane, cytosolic, and nuclear proteins, in addition to noncoding RNAs, other RNA types, and double-stranded DNA fragments. These shed vesicles may deposit paracrine information and can also be taken up by stromal cells, causing the recipient cells to undergo phenotypic changes that profoundly impact diverse facets of cancer progression. For example, this unique form of cellular cross talk helps condition the premetastatic niche, facilitates evasion of the immune response, and promotes invasive and metastatic activity. These findings, coupled with those demonstrating that the number and content of EVs produced by tumors can vary depending on their tumor of origin, disease stage, or response to therapy, have raised the exciting possibility that EVs can be used for risk stratification, diagnostic, and even prognostic purposes. We summarize recent developments and the current knowledge of EV cargoes, their impact on disease progression, and implementation of EV-based liquid biopsies as tumor biomarkers.

Acute-Onset Footdrop Caused by Intraneural Ganglion Cyst of the Common Peroneal Nerve: The Effects of Extraneural Pressure Gradients on Cyst Propagation.

Ganglion cysts are relatively common entities, but intraneural ganglia within peripheral nerves are rare and poorly understood. We present a case of a 51-year-old man who presented with acute left dropfoot. Initial magnetic resonance imaging (MRI) was misinterpreted as common peroneal neuritis consistent with a traction injury corroborated by the patient's history. However, after surgical decompression and external neurolysis were performed, the patient's symptoms worsened. Repeated MRI revealed an intraneural ganglion cyst of the common peroneal nerve with connection to the superior tibiofibular joint by means of its anterior recurrent branch that was evident retrospectively on preoperative MRI. It is crucial to carefully inspect atypical cases to further recognize and appreciate the dynamic aspect of this disease or "roller-coaster" phenomenon. Intraneural ganglion cysts rely heavily on intraneural and extraneural pressure gradients for propagation, which can be drawn from the expanded work of the unifying articular theory. This report emphasizes the importance of understanding the pathoanatomical and hydraulic factors to appropriately identify and treat intraneural ganglion cysts. Increased recognition of this pathologic entity as a differential diagnosis for acute onset dropfoot is also highlighted.

Recruitment of DNA to tumor-derived microvesicles.

The shedding of extracellular vesicles (EVs) represents an important but understudied means of cell-cell communication in cancer. Among the currently described classes of EVs, tumor-derived microvesicles (TMVs) comprise a class of vesicles released directly from the cell surface. TMVs contain abundant cargo, including functional proteins and miRNA, which can be transferred to and alter the behavior of recipient cells. Here, we document that a fraction of extracellular double-stranded DNA (dsDNA) is enclosed within TMVs and protected from nuclease degradation. dsDNA inclusion in TMVs is regulated by ARF6 cycling and occurs with the cytosolic DNA sensor, cGAS, but independent of amphisome or micronuclei components. Our studies suggest that dsDNA is trafficked to TMVs via a mechanism distinct from the multivesicular body-dependent secretion reported for the extracellular release of cytosolic DNA. Furthermore, TMV dsDNA can be transferred to recipient cells with consequences to recipient cell behavior, reinforcing its relevance in mediating cell-cell communication.

Inhibition of N-Nitrosamine Formation in Drug Products: A Model Study.

Nitrosamines, in the absence of toxicological data, are regarded as potential mutagens and need to be controlled at nanogram levels in drug products. Recent high profile product withdrawals have increased regulatory scrutiny of nitrosamine formation assessments for marketed products and for new drug applications. Formation of nitrosamine in drug product is possible when nitrite and vulnerable amines are present. Nitrite is often present as an impurity in excipients at ppm levels, whereas vulnerable amines, if present, stem mainly from the drug substance or its major impurities. In the event a drug product were to contain a major source of vulnerable amines (such as a moiety in the drug substance), it would be desirable to have an inhibitor which could be added to the formulation to minimize nitrosamine formation.  This work demonstrates, for the first time, that the inhibition of nitrosamine formation in oral solid dosage forms is indeed feasible with suitable inhibitors. Five inhibitors investigated (ascorbic acid, sodium ascorbate, α-tocopherol, caffeic acid, and ferulic acid) showed >80% inhibition when spiked at ∼1 wt% level. This work has also shown the potential use of amino acids (glycine, lysine, histidine) as inhibitors of nitrosamine formation in solution.

The ins and outs of microvesicles.

Microvesicles are a heterogeneous group of membrane-enclosed vesicles that are released from cells into the extracellular space by the outward budding and pinching of the plasma membrane. These vesicles are loaded with multiple selectively sorted proteins and nucleic acids. Although interest in the clinical potential of microvesicles is increasing, there is only limited understanding of different types of microvesicles and the mechanisms involved in their formation. Here, we describe what is presently known about this expanding and complex field of research focusing on the mechanism of biogenesis, cargo loading, and release of microvesicles.

A bi-radial approach to define the sagittal geometry of the healthy ankle.

BACKGROUND: Previous descriptions of the sagittal geometry of the tibia and talus have involved single radius curves. The purpose of this investigation was to: determine if the sagittal curvature of the medial and lateral sides of the talus and tibia can be described by dividing the condyles into anterior and posterior regions, determine tibiotalar congruency, and categorize the morphological configurations of the talus and tibia. METHODS: Eighteen subjects underwent weightbearing CT scans and the osseous curvature was analyzed. RESULTS: For the talus, the medial anterior radius was smaller than the lateral anterior radius. For the distal tibia, the lateral posterior radius was smaller than the medial posterior radius. Tibiotalar congruency varied by region. The most common geometric configuration was two cones, one anterior and one posterior, pointed in opposite directions. CONCLUSION: The sagittal profiles of the tibia and talus can be more accurately described using a bi-radial approach as compared to a single radius.

Breaking Bad: Extracellular Vesicles Provoke Tumorigenic Responses Under Oxygen Deprivation.

Intercellular communication is vital to tumor progression. In this issue of Developmental Cell, Bertolini et al. (2020) describe how small extracellular vesicles released from hypoxic mammary tumor cells facilitate intercellular communication, leading to alterations in mitochondrial dynamics and acquisition of invasive phenotypes in normal epithelial cells.

Rab11b-mediated integrin recycling promotes brain metastatic adaptation and outgrowth.

Breast cancer brain metastases (BCBM) have a 5-20 year latency and account for 30% of mortality; however, mechanisms governing adaptation to the brain microenvironment remain poorly defined. We combine time-course RNA-sequencing of BCBM development with a Drosophila melanogaster genetic screen, and identify Rab11b as a functional mediator of metastatic adaptation. Proteomic analysis reveals that Rab11b controls the cell surface proteome, recycling proteins required for successful interaction with the microenvironment, including integrin ß1. Rab11b-mediated control of integrin ß1 surface expression allows efficient engagement with the brain ECM, activating mechanotransduction signaling to promote survival. Lipophilic statins prevent membrane association and activity of Rab11b, and we provide proof-of principle that these drugs prevent breast cancer adaptation to the brain microenvironment. Our results identify Rab11b-mediated recycling of integrin ß1 as regulating BCBM, and suggest that the recycleome, recycling-based control of the cell surface proteome, is a previously unknown driver of metastatic adaptation and outgrowth.

Two critical thinking models-probing questions and conceptualization-adding 4 skillsets to the teacher's armamentarium.

Critical thinking is ubiquitous in patient care. One track for critical thinking develops skillsets emulating the thought process of the master clinician using probing questions and has been offered in treatment planning, literature search, and critique, risk assessment in caries and geriatrics, technology decision-making, EBD, and IPP. This paper offers 2 additional critical thinking skillsets following this emulation model in social work and ethics. Conceptualization, another form of critical thinking, is also ubiquitous in health care, yet almost no literature exists to guide learning and assess performance on conceptualization. This paper introduces for discussion 2 examples of conceptualization-"How and how much does this situation differ from the ideal?" and "How does the student/practitioner conceptualize the outcome prior to the imminent procedure?" -used continually by the practitioner in patient care situations. The result is 4 additional critical thinking skillsets at different stages of development in the armamentarium for the teacher.

Spontaneous Rupture of Multiple Tendons in the Lower Extremity Following the Diagnosis of Lyme Disease.

Over a time frame of less than 1 year, a 23-year-old competitive horseback rider experienced a midsubstance tear of both the tibialis anterior and extensor hallucis longus tendons without inciting injury. It was after the second spontaneous tear that the patient's recent diagnosis of Lyme disease became the likely culprit. Often, patients with chronic Lyme disease present with an elaborate clinical picture that can mimic many more common diagnoses such as septic arthritis, transient synovitis, ligamentous sprain, and various other traumatic injuries. With the pathognomonic erythema migrans rash reported to be present less than 50% of the time in late-stage infections, the diagnosis of Lyme disease can often be difficult, with a high rate of underdiagnosis. It is important that Lyme disease be included in the differential diagnosis of spontaneous tendon pathology, especially for physicians practicing in highly endemic areas. The treatment is relatively simple and successful-especially for an acute infection-and it is important to initiate treatment promptly to prevent disability.

An ARF6-Exportin-5 axis delivers pre-miRNA cargo to tumour microvesicles.

Tumour-derived microvesicles (TMVs) comprise a class of extracellular vesicles released from tumour cells that are now understood to facilitate communication between the tumour and the surrounding microenvironment. Despite their significance, the regulatory mechanisms governing the trafficking of bioactive cargos to TMVs at the cell surface remain poorly defined. Here we describe a molecular pathway for the delivery of microRNA (miRNA) cargo to nascent TMVs involving the dissociation of a pre-miRNA/Exportin-5 complex from Ran-GTP following nuclear export and its subsequent transfer to a cytoplasmic shuttle comprised of ARF6-GTP and GRP1. As such, ARF6 activation increases the pre-miRNA cargo contained within TMVs through a process that requires the casein kinase 2-mediated phosphorylation of RanGAP1. Furthermore, TMVs were found to contain pre-miRNA processing machinery including Dicer and Argonaute-2, which allow for cell-free pre-miRNA processing within shed vesicles. These findings offer cellular targets to block the loading and processing of pre-miRNAs within TMVs.

Coordinated Regulation of Intracellular Fascin Distribution Governs Tumor Microvesicle Release and Invasive Cell Capacity.

Tumor cell invasion is one result of the bidirectional interactions occurring between tumor cells and the surrounding milieu. The ability of tumor cells to invade through the extracellular matrix is in part regulated by the formation of a class of protease-loaded extracellular vesicles, called tumor microvesicles (TMVs), which are released directly from the cell surface. Here we show that the actin bundling protein, fascin, redistributes to the cell periphery in a ternary complex with podocalyxin and ezrin, where it promotes TMV release. The peripheral localization of fascin is prompted by the loss of Rab35 signaling, which in turn unleashes ARF6 activation. The result is a mechanism through which Rab35 and ARF6 cooperatively and simultaneously regulate the distribution and localization of fascin and promote oncogenic signaling, which leads to TMV release while inhibiting invadopodium formation. These studies are clinically significant as fascin-loaded TMVs can be detected in bodily fluids and elevated fascin expression coupled with low Rab35 levels correlates with poor overall survival in some cancers.

Aberrant endocytosis leads to the loss of normal mitotic spindle orientation during epithelial glandular morphogenesis.

Epithelial cells form tissues with many functions, including secretion and environmental separation and protection. Glandular epithelial tissues comprise cysts and tubules that are formed from a polarized, single-epithelial cell layer surrounding a central, fluid-filled lumen. The pathways regulating key processes in epithelial tissue morphogenesis such as mitotic spindle formation are incompletely understood, but are important to investigate, as their dysregulation is a signature of epithelial tumors. Here, we describe a signaling axis that manifests in a defect in mitotic spindle orientation during epithelial growth and cystogenesis. We found that activation of the small GTPase ADP-ribosylation factor 6 (ARF6) results in the sustained internalization of cell-surface components such as the cMet receptor and the cell-adhesion molecule E-cadherin. The spindle orientation defect arising from elevated levels of ARF6-GTP required an increase in cMet endocytosis, but was independent of E-cadherin internalization or elevated extracellular signal-regulated kinase (ERK) activity resulting from internalized receptor signaling on endosomes. Misorientation of the mitotic spindle resulted in the development of epithelial cysts with structural abnormalities, the most conspicuous of which was the presence of multiple intercellular lumens. Abnormal mitotic spindle orientation was necessary but insufficient to disrupt glandular development, as blocking the strong prosurvival signal resulting from ERK hyperactivation yielded structurally normal cysts despite continued manifestation of spindle orientation defects. Our findings highlight a previously unknown link between ARF6 activation, cMet receptor internalization, and mitotic spindle orientation during epithelial glandular morphogenesis.

Extracellular Vesicles in Cancer: Purpose and Promise.

Extracellular vesicles refer collectively to a heterogeneous group of membrane-bound vesicles released from cells and loaded with bioactive proteins, nucleic acids, and lipids. The concept of extracellular vesicles has rapidly evolved from once being viewed as cellular debris to their recognition as packets of cellular information with considerable promise for clinical applications as biomarker platforms and therapeutic vehicles. These shed vesicles have emerged as critical mediators of intercellular communication in both local and distant microenvironments during normal physiological processes, as well as in orchestrating systemic pathophysiological events in disease. This mode of cellular crosstalk is particularly relevant to modulating the tumor microenvironment and orchestrating paths of least resistance during metastases. Here, we describe recent advances for the roles of extracellular vesicles in tumor progression and their potential as disease biomarkers.

Biology and biogenesis of shed microvesicles.

The ability of cells to transmit bioactive molecules to recipient cells and the extracellular environment is a fundamental requirement for both normal physiology and disease pathogenesis. It has traditionally been thought that soluble factors released from cells were responsible for this cellular signaling but recent research has revealed a fundamental role for microvesicles in this process. Microvesicles are heterogeneous membrane-bound sacs that are shed from the surface of cells into the extracellular environment in a highly regulated process. They are shed following the selective incorporation of a host of molecular cargo including multiple types of proteins and nucleic acids. In addition to providing new insight into the etiology of complex human diseases, microvesicles also show great promise as a tool for advanced diagnosis and therapy as we move forward into a new age of personalized medicine. Here we review current status of the rapidly evolving field of microvesicle biology, highlighting critical regulatory roles for several small GTPases in the biology and biogenesis of shed microvesicles.

Extracellular microvesicles and invadopodia mediate non-overlapping modes of tumor cell invasion.

Tumor cell invasion requires the molecular and physical adaptation of both the cell and its microenvironment. Here we show that tumor cells are able to switch between the use of microvesicles and invadopodia to facilitate invasion through the extracellular matrix. Invadopodia formation accompanies the mesenchymal mode of migration on firm matrices and is facilitated by Rac1 activation. On the other hand, during invasion through compliant and deformable environments, tumor cells adopt an amoeboid phenotype and release microvesicles. Notably, firm matrices do not support microvesicle release, whereas compliant matrices are not conducive to invadopodia biogenesis. Furthermore, Rac1 activation is required for invadopodia function, while its inactivation promotes RhoA activation and actomyosin contractility required for microvesicle shedding. Suppression of RhoA signaling blocks microvesicle formation but enhances the formation of invadopodia. Finally, we describe Rho-mediated pathways involved in microvesicle biogenesis through the regulation of myosin light chain phosphatase. Our findings suggest that the ability of tumor cells to switch between the aforementioned qualitatively distinct modes of invasion may allow for dissemination across different microenvironments.