Deletion of mouse lysyl oxidase in megakaryocytes affects bone properties in a sex-dependent manner.

Lysyl oxidase (LOX) is a facilitator of extracellular matrix cross-linking. Using newly developed megakaryocyte-specific LOX knockout mice, we show that LOX expressed in these scarce bone marrow cells affects bone volume and collagen architecture in a sex-dependent manner.

Inhibition of Osteoblast Differentiation by JAK2V617F Megakaryocytes Derived From Male Mice With Primary Myelofibrosis.

Past studies described interactions between normal megakaryocytes, the platelet precursors, and bone cell precursors in the bone marrow. This relationship has also been studied in context of various mutations associated with increased number of megakaryocytes. The current study is the first to examine the effects of megakaryocytes from transgenic mice carrying the most common mutation that causes primary myelofibrosis (PMF) in humans (JAK2V617F) on bone cell differentiation. Organ level assessments of mice using micro-computed tomography showed decreased bone volume in JAK2V617F males, compared to matching controls. Tissue level histology revealed increased deposition of osteoid (bone matrix prior mineralization) in these mutated mice, suggesting an effect on osteoblast differentiation. Mechanistic studies using a megakaryocyte-osteoblast co-culture system, showed that both wild type or JAK2V617F megakaryocytes derived from male mice inhibited osteoblast differentiation, but JAK2V617F cells exerted a more significant inhibitory effect. A mouse mRNA osteogenesis array showed increased expression of Noggin, Chordin, Alpha-2-HS-glycoprotein, Collagen type IV alpha 1 and Collagen type XIV alpha 1 (mostly known to inhibit bone differentiation), and decreased expression of alkaline phosphatase, Vascular cell adhesion molecule 1, Sclerostin, Distal-less homeobox 5 and Collagen type III alpha 1 (associated with osteogenesis) in JAK2V617F megakaryocytes, compared to controls. This suggested that the mutation re-programs megakaryocytes to express a cluster of genes, which together could orchestrate greater suppression of osteogenesis in male mice. These findings provide mechanistic insight into the effect of JAK2V617F mutation on bone, encouraging future examination of patients with this or other PMF-inducing mutations.

Characterization of Glycoproteoforms of Integrins α2 and ß1 in Megakaryocytes in the Occurrence of JAK2V617F Mutation-Induced Primary Myelofibrosis.

Primary myelofibrosis (PMF) is a neoplasm prone to leukemic transformation, for which limited treatment is available. Among individuals diagnosed with PMF, the most prevalent mutation is the JAK2V617F somatic point mutation that activates the Janus kinase 2 (JAK2) enzyme. Our earlier reports on hyperactivity of ß1 integrin and enhanced adhesion activity of the α2ß1 complex in JAK2V617F megakaryocytes (MKs) led us to examine the new hypothesis that this mutation leads to posttranslational modification via changes in glycosylation. Samples were derived from immunoprecipitation of MKs obtained from Vav1-hJAK2V617F and WT mice. Immunoprecipitated fractions were separated by SDS-PAGE and analyzed using LC-MS/MS techniques in a bottom-up glycoproteomics workflow. In the immunoprecipitate, glycopeptiforms corresponding to 11 out of the 12 potential N-glycosylation sites of integrin ß1 and to all nine potential glycosylation sites of integrin α2 were observed. Glycopeptiforms were compared across WT and JAK2V617F phenotypes for both integrins. The overall trend observed is that JAK2V617F mutation in PMF MKs leads to changes in ß1 glycosylation; in most cases, it results in an increase in the integrated area of glycopeptiforms. We also observed that in mutated MKs, changes in integrin α2 glycosylation were more substantial than those observed for integrin ß1 glycosylation, a finding that suggests that altered integrin α2 glycosylation may also affect activation. Additionally, the identification of proteins associated to the cytoskeleton that were co-immunoprecipitated with integrins α2 and ß1 demonstrated the potential of the methodology employed in this study to provide some insight, at the peptide level, into the consequences of integrin activation in MKs. The extensive and detailed glycosylation patterns we uncovered provide a basis for future functional studies of each site in control cells as compared to JAK2V617F-mutated cells. Data are available via ProteomeXchange with identifier PXD030550.

Myeloproliferative disorders and their effects on bone homeostasis: the role of megakaryocytes.

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of chronic hematological diseases that arise from the clonal expansion of abnormal hematopoietic stem cells, of which polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) have been extensively reviewed in the context of control of clonal expansion, fibrosis, and other phenotypes. Herein, we review current knowledge on the influence of different forms of MPN on bone health. In studies, murine models and human data have implicated various degrees of effect of different forms of MPN on bone density and on osteoblast proliferation and differentiation. Most results have shown that bone volume is generally increased in patients with PMF, whereas it is slightly decreased or not altered in patients with ET or PV, although possible differences between male and female phenotypes were not fully explored in most MPN forms. Osteosclerosis in patients with PMF is a serious complication that can lead to bone marrow failure, and the loss of bone reported in some patients with ET or PV can lead to osteoporotic fractures. Some MPN forms are associated with an increased number of megakaryocytes (MKs), and several of the MK-associated factors in MPN are known to affect bone development. We review known mechanisms involved in these processes, with a focus on the role of MKs and secreted factors. Understanding MPN-associated changes in bone health could improve early intervention and treatment of this side effect of the pathology.

Temporal trends in stroke incidence and case-fatality rates in Arcadia, Greece: A sequential, prospective, population-based study.

BACKGROUND: Stroke incidence and case-fatality are reported to decline in high-income countries during the last decades. Epidemiological studies are important for health services to organize prevention and treatment strategies. AIMS: The aim of this population-based study was to determine temporal trends of stroke incidence and case-fatality rates of first-ever stroke in Arcadia, a prefecture in southern Greece. METHODS: All first-ever stroke cases in the Arcadia prefecture were ascertained using the same standard criteria and multiple overlapping sources in three study periods: from November 1993 to October 1995; 2004; and 2015-2016. Crude and age-adjusted to European population incidence rates were compared using Poisson regression. Twenty-eight days case fatality rates were estimated and compared using the same method. RESULTS: In total, 1315 patients with first-ever stroke were identified. The age-standardized incidence to the European population was 252 per 100,000 person-years (95% CI 231-239) in 1993/1995, 252 (95% CI 223-286) in 2004, and 211 (192-232) in 2015/2016. The overall age- and sex-adjusted incidence rates fell by 16% (incidence rates ratio 0.84, 95% CI: 0.72-0.97). Similarly, 28-day case-fatality rate decreased by 28% (case fatality rate ratio = 0.72, 95% CI: 0.58-0.90). CONCLUSIONS: This population-based study reports a significant decline in stroke incidence and mortality rates in southern Greece between 1993 and 2016.

Adhesion to fibronectin via α5ß1 integrin supports expansion of the megakaryocyte lineage in primary myelofibrosis.

Excessive accumulation of extracellular matrix (ECM) is a hallmark of bone marrow (BM) milieu in primary myelofibrosis (PMF). Because cells have the ability to adhere to the surrounding ECM through integrin receptors, we examined the hypothesis that an abnormal ECM-integrin receptor axis contributes to BM megakaryocytosis in JAK2V617F+ PMF. Secretion of ECM protein fibronectin (FN) by BM stromal cells from PMF patients correlates with fibrosis and disease severity. Here, we show that Vav1-hJAK2V617F transgenic mice (JAK2V617F+) have high BM FN content associated with megakaryocytosis and fibrosis. Further, megakaryocytes from JAK2V617F+ mice have increased cell surface expression of the α5 subunit of the α5ß1 integrin, the major FN receptor in megakaryocytes, and augmented adhesion to FN compared with wild-type controls. Reducing adhesion to FN by an inhibitory antibody to the α5 subunit effectively reduces the percentage of CD41+ JAK2V617F+ megakaryocytes in vitro and in vivo. Corroborating our findings in mice, JAK2V617F+ megakaryocytes from patients showed elevated expression of α5 subunit, and a neutralizing antibody to α5 subunit reduced adhesion to FN and megakaryocyte number derived from CD34+ cells. Our findings reveal a previously unappreciated contribution of FN-α5ß1 integrin to megakaryocytosis in JAK2V617F+ PMF.

Spinal angiolipoma: Presentation of two cases and review of the literature for the years 2012-2017 / Angiolipoma espinal: descripción de 2 casos y revisión de la bibliografía durante los años 2012-2017

INTRODUCTION AND OBJECTIVES: Angiolipomas of the spinal canal are a rare condition of unknown origin. They are considered histologically benign; however, some have the potential to infiltrate adjacent structures. The aim of this systematic review was to suggest a potential mechanism for the pathogenesis of spinal angiolipomas, along with a useful approach for their preoperative management. MATERIALS AND METHODS: A literature review of cases of spinal angiolipoma was performed. In addition, two of the cases encountered in our practice are presented. The first case refers to a 35-year-old male patient with a history of spinal fusion because of a T9 fracture, while the second concerns a 46-year-old male patient with an epidural mass extending outside the spinal canal, who underwent fine needle biopsy and embolisation of its feeding vessel. RESULTS: From the review of the literature performed, we were unable to identify any correlation between the infiltrative potential and the patients' demographic and tumour characteristics. CONCLUSIONS: Angiolipomas are considered to be sporadic, yet theories concerning their pathogenesis include reaction to harmful stimuli and congenital malformation of the adipose tissue. Fine needle biopsy may be mistakenly considered non-diagnostic, due to the presence of well-differentiated adipocytes

INTRODUCCIÓN Y OBJETIVOS: Los angiolipomas del canal vertebral son una enfermedad rara de origen desconocido. Se consideran histológicamente benignos, aunque en algunos casos existe la posibilidad de que se infiltren en estructuras adyacentes. El objetivo de esta revisión sistemática es sugerir un posible mecanismo para la patogenia de los angiolipomas espinales, junto con un enfoque útil para su tratamiento preoperatorio. Materiales y métodos: Se realizó una búsqueda bibliográfica de los casos de angiolipomas espinales. Además, se presentan 2 de los casos encontrados en nuestra práctica clínica. El primer caso corresponde a un paciente varón de 35 años con antecedentes de artrodesis vertebral debido a una fractura en T9, mientras que el segundo corresponde a un paciente varón de 46 años con una masa epidural que se extendía fuera del canal vertebral, al que se realizó una biopsia con aguja fina y una embolización del vaso nutricio. RESULTADOS: A partir de la revisión bibliográfica realizada, no pudimos identificar ninguna correlación entre el potencial de infiltración, los datos demográficos y las características de los tumores de los pacientes. CONCLUSIONES: Los angiolipomas se consideran esporádicos, existiendo, no obstante, teorías referentes a su patogenia que incluyen la reacción a estímulos nocivos y la malformación congénita del tejido adiposo. La biopsia con aguja fina puede considerarse erróneamente como no diagnóstica, debido a la presencia de adipocitos bien diferenciados

Fetal subependymal giant cell astrocytoma: A case report and review of the literature.

BACKGROUND: Subependymal giant cell astrocytomas (SEGAs) appear approximately in 10% of patients with tuberous sclerosis. These tumors are most commonly diagnosed in childhood and adolescence, with in utero diagnosed SEGAs being an extremely rare entity. CASE DESCRIPTION: We present the case of a congenital SEGA detected in an antenatal ultrasound and further investigated with fetal magnetic resonance imaging (MRI) scans at 22 and 32 weeks of gestational age. At 9 days of age, the child underwent craniotomy and partial excision of the tumor, followed by a second more extensive operation 13 days later. The patient was subsequently administered mammalian target of rapamycin inhibitor (everolimus). CONCLUSION: In the latest follow-up MRI, at the age of two, the SEGA remained unchanged. Management of these tumors in neonates is challenging, mainly due to high morbidity and mortality of surgical treatment in these ages.

The use of crevicular fluid to assess markers of inflammation and angiogenesis, IL-17 and VEGF, in patients with solid tumors receiving zoledronic acid and/or bevacizumab.

PURPOSE: Crevicular fluid was used to assess interleukin-17 (IL-17) and vascular endothelial growth factor (VEGF) in cancer patients receiving zoledronic acid and/or bevacizumab. The markers were also assessed in the serum. METHODS: Twenty-five patients were included and comprised three groups: patients who received zoledronic acid (n = 9), patients who received bevacizumab (n = 9), and patients who received zoledronic acid combined with bevacizumab (n = 5). One patient received zoledronic acid and everolimus and another received zoledronic acid, bevacizumab, and temsirolimus. IL-17 and VEGF were measured by standard quantitative ELISA kits and assessed in two study points. RESULTS: Twenty-four patients maintained good periodontal health; one had asymptomatic osteonecrosis of the jaw. First assessment: 44 samples were collected; 21 from serum and 23 from crevicular fluid. Second assessment, 6 months later: 11 samples were collected; 6 from serum and 5 from crevicular fluid. IL-17 was detected in all samples, in serum and crevicular fluid, and remained unchanged at both time points. Serum VEGF in patients with bevacizumab alone or combined with zoledronic acid was significantly lower compared with that of patients who received zoledronic acid alone. VEGF was not detected in the crevicular fluid. CONCLUSIONS: Crevicular fluid might be an easy, non-invasive means to assess IL-17. The stable values of IL-17 in crevicular fluid and serum and the lack of VEGF in the crevicular fluid could be related to the good periodontal health of our patients. Further studies are needed to assess IL-17 and VEGF in the crevicular fluid in patients with and without periodontal disease.

Spinal angiolipoma: Presentation of two cases and review of the literature for the years 2012-2017.

INTRODUCTION AND OBJECTIVES: Angiolipomas of the spinal canal are a rare condition of unknown origin. They are considered histologically benign; however, some have the potential to infiltrate adjacent structures. The aim of this systematic review was to suggest a potential mechanism for the pathogenesis of spinal angiolipomas, along with a useful approach for their preoperative management. MATERIALS AND METHODS: A literature review of cases of spinal angiolipoma was performed. In addition, two of the cases encountered in our practice are presented. The first case refers to a 35-year-old male patient with a history of spinal fusion because of a T9 fracture, while the second concerns a 46-year-old male patient with an epidural mass extending outside the spinal canal, who underwent fine needle biopsy and embolisation of its feeding vessel. RESULTS: From the review of the literature performed, we were unable to identify any correlation between the infiltrative potential and the patients' demographic and tumour characteristics. CONCLUSIONS: Angiolipomas are considered to be sporadic, yet theories concerning their pathogenesis include reaction to harmful stimuli and congenital malformation of the adipose tissue. Fine needle biopsy may be mistakenly considered non-diagnostic, due to the presence of well-differentiated adipocytes.

En Plaque Meningioma Presenting as a Cutaneous Nodule.

Meningiomas are the most common central nervous system tumor and can be found anywhere in the neuraxis. In rare cases, they may extend beyond the cranial vault, while cases without evidence of intracranial mass existence have also been reported. Here, we report the case of a 64-year-old male patient with a history of craniectomy for parasagittal meningioma, who presented at the emergency department with onset of focal seizures. The patient underwent nonenhanced brain computed tomography scan which was indicative of recurrence of the mass. The patient was scheduled for craniotomy and excision of the mass. He also expressed his desire to have a scalp nodule removed concomitantly. Thickening of the meninges underlying the nodule was observed but without indication of a space-occupying lesion. Both histological examinations were suggestive of Grade II, atypical meningiomas. A case of a subcutaneous meningioma in a patient with a history of surgically excised parasagittal meningioma is presented. Radiologic evidence of dural proliferation underlying the mass was suggestive of an en plaque meningioma secondary to iatrogenic dissemination of tumor cells.

Primitive synovial sarcoma of suboccipital region in child.

Synovial sarcoma (SS) most commonly affects the lower limbs of males in the third to fifth decades of life, with masses of the head and neck accounting for 3-10% of all cases, mainly as a metastatic lesion. The lack of specific symptoms and radiological features in addition to the diversity of their microscopic aspects may cause confusion in the diagnosis; hence, knowledge of the unusual locations of SSs is very important. The immunohistochemistry, and more recently the cytogenetic studies, contribute to the differential diagnosis. We report the case of a 12-year-old girl with a rare primary SS in the suboccipital region, which underwent complete surgical resection.

Delayed Intraventricular Hemorrhage following a Ventriculoperitoneal Shunt Placement: Exploring the Surgical Anatomy of a Rare Complication.

Ventriculoperitoneal shunt (VPS) placement is one of the commoner neurosurgical procedures worldwide. The purpose of this article is to report a case of delayed intraventricular hemorrhage (IVH) following a VPS and to review the literature regarding anatomic factors that could potentially explain this rare complication. A 78-year-old man with normal pressure hydrocephalus, who underwent an uneventful right VPS placement, suffered from a catastrophic isolated IVH five days later. The reported cases of delayed intracerebral hemorrhage (ICH) following VPS are rare and those with IVH are even rarer. Potential factors of surgical anatomy that could cause delayed ICH/IVH following a VPS procedure include erosion of vasculature by catheter cannulation, multiple attempts at perforation, puncture of the choroid plexus, improper placement of the tubing within the brain parenchyma, VPS system revision, venous infarction, vascular malformations, head trauma, and brain tumors. Other causes include generalized convulsion, VPS system malfunction, increased intracranial or blood pressure, sudden intracranial hypotension, and bleeding disorders. According to the current literature, our case is the first reported delayed isolated IVH after a VPS placement so far. Neurosurgeons should be aware of the delayed ICH/IVH as a rare, potentially fatal complication of VPS, as well as of its risk factors.