Somatic mutational landscape of extracranial arteriovenous malformations and phenotypic correlations.

BACKGROUND: Somatic genetic variants may be the cause of extracranial arteriovenous malformations, but few studies have explored these genetic anomalies, and no genotype-phenotype correlations have been identified. OBJECTIVES: The aim of the study was to characterize the somatic genetic landscape of extracranial arteriovenous malformations and correlate these findings with the phenotypic characteristics of these lesions. METHODS: This study included twenty-three patients with extracranial arteriovenous malformations that were confirmed clinically and treated by surgical resection, and for whom frozen tissue samples were available. Targeted next-generation sequencing analysis of tissues was performed using a gene panel that included vascular disease-related genes and tumour-related genes. RESULTS: We identified a pathogenic variant in 18 out of 23 samples (78.3%). Pathogenic variants were mainly located in MAP2K1 (n = 7) and KRAS (n = 6), and more rarely in BRAF (n = 2) and RASA1 (n = 3). KRAS variants were significantly (P < 0.005) associated with severe extended facial arteriovenous malformations, for which relapse after surgical resection is frequently observed, while MAP2K1 variants were significantly (P < 0.005) associated with less severe, limited arteriovenous malformations located on the lips. CONCLUSIONS: Our study highlights a high prevalence of pathogenic somatic variants, predominantly in MAP2K1 and KRAS, in extracranial arteriovenous malformations. In addition, our study identifies for the first time a correlation between the genotype, clinical severity and angiographic characteristics of extracranial arteriovenous malformations. The RAS/MAPK variants identified in this study are known to be associated with malignant tumours for which targeted therapies have already been developed. Thus, identification of these somatic variants could lead to new therapeutic options to improve the management of patients with extracranial arteriovenous malformations.

Versatile and precise gene-targeting strategies for functional studies in mammalian cell lines.

The advent of programmable nucleases such as ZFNs, TALENs and CRISPR/Cas9 has brought the power of genetic manipulation to widely used model systems. In mammalian cells, nuclease-mediated DNA double strand break is mainly repaired through the error-prone non-homologous end-joining (NHEJ) repair pathway, eventually leading to accumulation of small deletions or insertions (indels) that can inactivate gene function. However, due to the variable size of the indels and the polyploid status of many cell lines (e.g., cancer-derived cells), obtaining a knockout usually requires lengthy screening and characterization procedures. Given the more precise type of modifications that can be introduced upon homology-directed repair (HDR), we have developed HDR-based gene-targeting strategies that greatly facilitate the process of knockout generation in cell lines. To generate reversible knockouts (R-KO), a selectable promoter-less STOP cassette is inserted in an intron, interrupting transcription. Loss-of-function can be validated by RT-qPCR and is removable, enabling subsequent restoration of gene function. A variant of the R-KO procedure can be used to introduce point mutations. To generate constitutive knockouts (C-KO), an exon is targeted, which makes use of HDR-based gene disruption together with NHEJ-induced indels on non-HDR targeted allele(s). Hence the C-KO procedure greatly facilitates simultaneous inactivation of multiple alleles. Overall these genome-editing tools offer superior precision and efficiency for functional genetic approaches. We provide detailed protocols guiding in the design of targeting vectors and in the analysis and validation of gene targeting experiments.

The Multiple Facets of PRC2 Alterations in Cancers.

Genome sequencing of large cohorts of tumors has revealed that mutations in genes encoding chromatin regulators are frequent in cancer. However, the precise contribution of these mutations to tumor development often remains elusive. Here, we review the current knowledge concerning the alterations of the Polycomb machinery in cancer, with a particular focus on the Polycomb repressive complex 2 (PRC2), a key chromatin modifier involved in the maintenance of transcriptional silencing. A broad variety of alterations can impair PRC2 activity; yet, overall, only one type of alteration is found in a given class of tumor. We discuss the potential impact of the various types of PRC2 alterations on gene expression. We propose that the distinct set of genes regulated by PRC2, depending on tumor etiology, constrain the type of alteration of PRC2 that can fuel tumor development. Beyond this specificity, we propose that PRC2 and, more generally, chromatin regulators act as gatekeepers of transcriptional integrity, a role that often confers a tumor-suppressive function.

Association between EZH2 expression, silencing of tumor suppressors and disease outcome in solid tumors.

EZH2, the main catalytic component of the Polycomb Repressive Complex 2 (PRC2) is apparently upregulated in most solid tumors. Furthermore its expression generally associates with poor prognosis. It was proposed that this correlation reflects a causal event, EZH2 mediating the silencing of key tumor suppressor loci. In contrast, we recently showed that EZH2 is dispensable for solid tumor development and that its elevated expression reflects the abnormally high proliferation rate of cancer cells. Here, we investigate the functional association between EZH2 expression and silencing of key tumor suppressor loci and further illustrate the confounding effect of proliferation on EZH2's association to outcome.

Aspergillus spp. invasive external otitis: favourable outcome with a medical approach.

Aspergillus spp. invasive external otitis (IEO) is a rare infection. We performed a seven-year, single-centre retrospective study from 2007 to 2014 including all patients with proven Aspergillus spp. IEO. Twelve patients were identified. All patients had a poorly controlled diabetes mellitus and one underwent solid organ transplant. The most frequently isolated species was Aspergillus flavus (n = 10) and voriconazole was the first-line therapy in all cases, with a median length of treatment of 338.5 days (158-804 days). None of the patients underwent extensive surgery. The clinical outcome was excellent. However, otological sequelae were reported, including hearing impairment (n = 7) and facial palsy (n = 3).

[Prevalence of granulomatous lesions in minor salivary gland biopsy in a case series of 65 patients with tuberculosis]. / Étude de la prévalence des granulomes à la biopsie des glandes salivaires accessoires chez 65 patients atteints de tuberculose.

PURPOSE: The distinction between tuberculosis (TB), a worldwide infectious granulomatosis requiring specific antibiotic therapy, and sarcoidosis, a rare granulomatous disease that may require corticosteroids is not straightforward and may result in diagnostic and therapeutic delay. METHODS: We prospectively and consecutively evaluated the presence of epithelioid granulomas in minor salivary gland biopsy of 65 consecutive patients with TB. RESULTS: In our study, 10.8 % of our TB patients had epithelioid granulomas without caseous necrosis identified in their minor salivary gland biopsy, regardless of the location of TB, HIV status and whether or not the sputum examination was positive for tuberculous bacilli. CONCLUSION: The presence of epithelioid granulomas in minor salivary gland biopsy may not be helpful to the clinician to rule out TB in a patient with suspected sarcoidosis.

Therapeutic efficacy of differentiated versus undifferentiated mesenchymal stem cells in experimental type I diabetes in rat.

Selective MSCs differentiation protocol into pancreatic beta cells was conducted in the present study using exendin-4 and TGF-beta. Differentiated and undifferentiated MSCs were assessed in experimental type I diabetes in rats. Ninety female white albino rats were included in the study and divided equally (n=15/group) into 6 groups: healthy control, healthy control rats received acellular tissue culture medium, diabetic rats, diabetic rats received acellular tissue culture medium, diabetic rats received undifferentiated MSCs and diabetic rats received differentiated MSCs. Therapeutic efficacy of undifferentiated versus differentiated MSCs was evaluated via assessment of quantitative gene expressions of insulin1, insulin 2, Smad-2, Smad-3, PDX-1, PAX-4, neuroD. Blood glucose and insulin hormone levels were also assessed. Results showed that quantitative gene expressions of all studied genes showed significant decrease in diabetic rat groups. Use of undifferentiated and differentiated MSCs led to a significant elevation of expression levels of all genes with more superior effect with differentiated MSCs except smad-2 gene. As regards insulin hormone levels, use of either undifferentiated or differentiated MSCs led to a significant elevation of its levels with more therapeutic effect with differentiated MSCs. Blood glucose levels were significantly decreased with both undifferentiated and differentiated MSCs in comparison to diabetic groups but its levels were normalized 2 months after injection of differentiated MSCs. In conclusion, use of undifferentiated or differentiated MSCs exhibited significant therapeutic potentials in experimental type I diabetes in rats with more significant therapeutic effect with the use of differentiated MSCs.

Milestones along the road of infection prevention in Egypt.

Sequela of infectious diseases include not only morbidity and mortality, but are also associated with chronic illnesses that has long constituted public health problems and huge economic burdens. This review gives a brief idea about important infectious diseases (ID) in Egypt, the main lines taken to combat them, the challenges still existing, and the possible barriers keeping IDs still forming threats to the community. Egypt has the highest prevalence rates of HCV infection worldwide. Significant evidence points towards that the HCV epidemic was initiated and propagated by the anti-schistosomal mass campaigns during the last century. Though the rates of HCV infection are declining, still the decline has not yet met the full expectations. Therefore, infection control programs are gaining more ground all over the country, especially with the growing problem of antimicrobial resistance complicating healthcare-associated infections (HAI) worldwide. Also, mass immnunization of childhood, mycobacterial tuberculosis infections, and avian influenza will be discussed.

Ossifying fibromas of the paranasal sinuses: diagnosis and management.

Fibro-osseous benign lesions rarely affect the sinonasal tract and are divided into 3 different entities, namely osteoma, fibrous dysplasia and ossifying fibroma. They share several clinical, radiological and histological similarities, but have different behaviours. Ossifying fibroma, and in particular the "juvenile" histological subtype, may have a locally aggressive evolution and a high risk for recurrence if removal is incomplete. The purpose of the present study is to compare the clinical behaviour of ossifying fibroma with the other benign fibro-osseous lesions; highlight different behaviour between the histological subtypes; compare the advantages, limitations and outcomes of an endoscopic endonasal approach with reports in the literature. We retrospectively reviewed 11 patients treated for sinonasal ossifying fibroma at a tertiary care centre. All patients underwent CT scan, and MRI was performed in cases of cranial base involvement or recurrence. Pre-operative biopsy was performed in cases where it was possible to use an endoscopic approach. One patient underwent pre-operative embolisation with ipsilateral visual loss after the procedure. Depending on its location, removal of the tumour was performed using an endoscopic (n = 7), or an external (n = 3) or combined (n = 1) approach. Histopathologically, 5 patients presented the conventional type, 5 the juvenile psammomatoid variant, which was associated in 1 case with an aneurismal bone cyst, and 1 case presented the trabecular juvenile variant. Three patients affected by the juvenile psammomatoid histological variant presented invasion of the skull base and underwent a subtotal removal that subsequently required, due to the regrowth of the remnant, a transbasal approach. Clinical, radiological and histological findings should all be considered to establish differential diagnosis among fibrous osseous lesions. More studies are necessary to conclude if the localisation and extension of the disease at the time of diagnosis is more important than the histological variant. An endoscopic approach is the first choice in most of cases even if an external open approach may be necessary in selected patients.

Radionecrosis of the frontal lobe as a consequence of malignant ethmoid tumor management: incidence, diagnosis, risk factors, prevention and management.

Malignant ethmoid tumors are treated by surgery followed by radiotherapy. This study aimed to evaluate the incidence, risk factors and outcome of radionecrosis of frontal lobe and determine preventive measures. Retrospective study of ethmoid malignancies treated from 2000 to 2011. All patients underwent surgery with/without anterior skull base resection using endoscopic or external approaches followed by irradiation (mean dose 64 Gy). Median follow-up was 50 months. Eight of 50 patients (16 %) presented with fronto-basal radionecrosis, connected to duraplasty, with a latent interval of 18.5 months. Although asymptomatic in six, radionecrosis triggered seizures and required surgery in two cases. Survival was not impacted. Risk factors included dyslipidemia, occurrence of epilepsy and dural resection. Radionecrosis may result from the combination of anterior skull base resection and radiotherapy for the treatment of ethmoid malignancies. Preventive measures rely on improving the duraplasty and optimization of the Gy-dose delivery.

Malignant head/neck paragangliomas. Comparative study.

BACKGROUND: The objective of this study was to report 11 cases of malignant head and neck paraganglioma and to compare their epidemiological, clinical, and genetic characteristics, their natural history and their treatment with those of a series of 131 benign paragangliomas. PATIENTS AND METHODS: Retrospective analysis of 142 patients with head and neck paraganglioma managed between 2001 and 2008. Age at the time of diagnosis, gender, primary tumour site, presence of other non-head/neck paragangliomas and/or metastases diagnosed by imaging (CT, MRI, Octreoscan or (18)F-FDG PET), histology, urinary catecholamine and metanephrine levels, family history, and genetic test results were recorded. RESULTS: This series comprised 131 benign head and neck paragangliomas, mostly observed in women with a mean age at diagnosis of 45 years and a predominance of tympanojugular sites (followed by carotid and vagal sites) with 5% of secreting tumours and 20% of multifocal tumours. Eleven patients (7.7%) with a 1:1 sex ratio presented criteria of malignancy. These patients, with a lower mean age (38 years), predominantly presented carotid lesions with a higher rate of secreting and multifocal tumours, 27% and 46% respectively. The main sites of metastases were bone and lymph nodes. No tympanic paragangliomas were observed. CONCLUSIONS: Malignant paragangliomas are mainly observed in young patients with multifocal tumours, particularly carotid tumours, and are predominantly related to subunit SDH-B mutation. The work-up in these high-risk patients must include whole body scintigraphy and spine MRI. Malignancy is not necessarily associated with a poor short-term prognosis due to the slow course of the disease.

Genotypes and phenotypes of 162 families with a glomulin mutation.

A decade ago, we identified a novel gene, glomulin (GLMN) in which mutations cause glomuvenous malformations (GVMs). GVMs are bluish-purple cutaneous vascular lesions with characteristic glomus cells in the walls of distended venous channels. The discovery of the genetic basis for GVMs allowed the definition of clinical features to distinguish GVMs from other venous anomalies. The variation in phenotype was also highlighted: from a single punctate blue dot to a large plaque-like lesion. In this study, we screened GLMN in a large cohort of patients to broaden the spectrum of mutations, define their frequency and search for possible genotype-phenotype correlations. Taking into account 6 families published by others, a mutation in GLMN has been found in 162 families. This represents 40 different mutations; the most frequent one being present in almost 45% of them. Expressivity varies largely, without a genotype/phenotype relationship. Among 381 individuals with a mutation, we discovered 37 unaffected carriers, implying a penetrance of 90%. As nonpenetrant individuals may transmit the disease to their descendants, knowledge on the mutational status is needed for appropriate genetic counseling.

[An atypical presentation of Kikuchi-Fujimoto disease]. / Maladie de Kikuchi-Fujimoto: une présentation atypique.

INTRODUCTION: Histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease) is a rare clinical entity characterized by the association of enlarged lymph nodes in the posterior cervical region and fever. The disease is more frequent in young women. CASE REPORT: We report a 41-year-old African patient who presented with atypical features of Kikuchi's disease including cutaneous lupus, haemophagocytosis, and lymphocytic meningitis. The ethnic origin and the clinical presentation were initially suggestive of tuberculous meningitis. However, microbiological analyses remained negative, histological findings were suggestive of Kikuchi's disease and HHV6 DNA integration was documented in our patient. CONCLUSION: Kikuchi's disease should be suspected in an African patient when lymphocytic meningitis is associated with enlarged cervical lymph nodes, hemophagocytosis and HHV6 DNA integration.

[Osteoma cutis presenting as an erythematous and grainy, retroauricular plaque]. / Ostéome cutané primaire à type de plaque rétro-auriculaire érythémateuse et grenue.

BACKGROUND: Authentic bone tissue can be observed in the skin, in both the epidermis and dermis, where it produces cutaneous osteomas. These lesions are classed as either primary or secondary ossifications. Secondary ossifications are the consequence of inflammatory lesions such as acne or injuries while primary ossifications are neither preceded by preexisting lesions nor associated with other lesions. PATIENTS AND METHODS: A 22-year-old man with no prior history consulted for a grainy, erythematous, telangiectatic retroauricular plaque on the right side. Palpation revealed hard grainy lesions giving a tactile sensation of small stones. Histological analysis showed an ossification in the dermis resulting from mature bone in contact with dilated vessels. A diagnosis of venous malformation with osseous metaplasia was initially proposed, but the patient insisted that no vascular anomaly had preceded the grainy lesions. Further histological analysis demonstrated that the vascular anomalies were restricted to the ossified regions and the final diagnosis was of primary cutaneous osteoma. DISCUSSION: In our patient, the absence of any endocrine anomalies and of any vascular malformation supported the diagnosis of primary cutaneous osteoma. Certain vascular anomalies such as haemangiomas or venous malformation can lead to bone formation. The coexistence in the dermis of osteomas and dilated vessels initially led us to suspect osteomas secondary to venous malformation. However, the absence of any vascular anomalies preceding the cutaneous osteoma contradicted this diagnosis. In venous malformations, phleboliths are usually seen as a result of calcium deposits on thrombus rather than authentic osteomas. Our patient had no standard primary solitary osteoma of either the nodular or the plaque type, and this case thus constitutes a new original form of primary cutaneous osteoma.

[Association of an arachnoid cyst with heterotopic neuroglial tissue in the internal auditory canal]. / Association d'un kyste arachnoïdien et d'une hétérotopie de tissu glial dans le méat auditif interne.

OBJECTIVES: We report a case of an association of an arachnoid cyst with heterotopic neuroglial tissue in the internal auditory canal. MATERIAL AND METHODS: A 66-year-old woman consulted for cochleovestibular syndrome. RESULTS: MRI demonstrated a lesion with spontaneous hypersignal on T1- and T2-weighted images, instigating surgical exploration. We discovered a hematic arachnoid cyst associated with heterotopic neuroglial tissue arising in the internal auditory canal. CONCLUSION: An arachnoid cyst arising within the cerebellopontine angle or the internal auditory canal is a rare occurrence. Clinical manifestations are identical with those produced by a cochleovestibular schwannoma. MRI usually demonstrates a nonenhancing isointense cystic mass with cerebrospinal fluid on all sequences (hypointense on T1-weighted and hyperintense on T2-weighted images). These lesions are usually monitored. Spontaneous hypersignal on T1- and T2-weighted images makes diagnosis difficult, as in our case, leading to surgical exploration.

Frequency and phenotypes of cutaneous vascular malformations in a consecutive series of 417 patients with familial cerebral cavernous malformations.

BACKGROUND: Familial cerebral cavernous malformations (FCCM) are vascular malformations inherited as an autosomal-dominant condition. Three genes (KRIT1/CCM1, MGC4607/CCM2, PDCD10/CCM3) have been identified so far. Extra-neurological manifestations include retinal and cutaneous vascular malformations. The cutaneous vascular malformation, which had been more specifically associated with FCCM, is hyperkeratotic cutaneous capillary venous malformation (HCCVM). OBJECTIVES: To define the frequency of cutaneous vascular malformations in patients with FCCM, to precise their different phenotypes, and to study the association of each cutaneous vascular malformation subtype with the different three mutated CCM genes. METHODS: Dermatological inquiry was systematically performed in a large series of consecutive FCCM patients. Cutaneous biopsies were reviewed when available. Cutaneous vascular malformations classification was based on predominant anomalous channels, using the current International Society for the Study of Vascular Anomalies classification. Molecular screening of CCM genes was performed. Results Four hundred seventeen consecutive FCCM patients from 182 unrelated families were included. 38 patients (9%) from 25 different families had cutaneous vascular malformations. In these 38 patients, cutaneous vascular malformations were classified as follows: 13 capillary malformations (CM), 15 HCCVM, 8 venous malformations (VM) and 2 unclassified lesions. All patients (92%), but one with CM had a KRIT1/CCM1 mutation. The last patient had no detectable mutation. All of the 15 patients with HCCVM had a KRIT1/CCM1 mutation; 86.7% of cutaneous vascular malformation patients (33 of 38) had a KRIT1/CCM1 mutation. CONCLUSION: Cutaneous vascular malformations are seen in 9% of FCCM patients. Three distinct major cutaneous vascular malformations phenotypes were identified: HCCVM (39%), CM (34%) and VM (21%). CCM1 is the most frequently mutated gene in cutaneous vascular malformations-FCCM patients.

Infrared microspectroscopy analysis of ibuprofen release from drug eluting beads in uterine tissue.

Ibuprofen loaded embolization beads (IBU-BB) have been developed to reduce inflammation and pain following uterine artery embolization for the treatment of uterine fibroids. The present work has investigated the elution properties of IBU-BB in situ after embolization with Fourier Transform Infrared Microspectroscopy (FTIRMS). Twelve sheep underwent uterine artery embolization with IBU-BB (485 mM) or control unloaded beads. IBU concentration was determined inside the beads and in the tissue surrounding the beads using FTIRMS of uterine tissue sections sampled 24 h or 1 week after embolization. After 24 h, IBU concentration inside the bead was only 18.6 mM out of the 485 mM initially loaded (p < 0.0001, univariate sign test). The concentration in the tissue around the beads was 8 mM, which is well above the in vitro therapeutic levels (6 microM). After one week the concentration of IBU had decreased to 4.9 mM in the beads (p = 0.0502, Mann Whitney) and no IBU was detected in the surrounding tissue. This work has demonstrated that IBU-BB can provide a sustained release of the anti-inflammatory drug over at least one week. The in vivo elution properties of IBU-BB may be suitable to alleviate pain and inflammation after embolization.

Effect of HO-1 cDNA-liposome complex transfer on erectile signalling of aged rats.

This work aimed to assess the efficacy of haeme oxygenase-1 (HO-1) cDNA-liposome complex transfer as a mediator of erectile signalling in aged rats. One hundred and fifty aged white albino rats were equally divided into five groups: controls, rats receiving lipofectamine, rats receiving intracorporeal HO-1 cDNA-lipsome complex, rats receiving HO-1 cDNA-liposome complex plus nitric oxide synthase (NOS) inhibitor, and rats receiving HO-1 cDNA-liposome complex plus HO inhibitor. Six rats were killed from each group after 12, 24 and 48 h, and after1 and 2 weeks. In dissected cavernous tissues, the following were assessed: HO-1 gene expression, Western blot for HO-1, HO enzyme activity, cGMP and histopathology. The results showed that HO-1 cDNA-liposome complex transfer led to a significant increase in cavernous tissue HO-1 protein, HO-1 gene expression, HO enzyme activity and cGMP up to 1 week. NOS inhibition exhibited no effect on HO-1 gene enhancement of cavernous tissue HO enzyme activity or cGMP, whereas inhibition of HO significantly decreased these parameters. Histopathology of cavernous tissue demonstrated a significant dilatation of helicine arteries in HO-1 cDNA-liposome complex treated group after 48 h compared with the controls. It is concluded that HO-1 cDNA-liposome complex transfer augments cavernous tissue cGMP with subsequent sinusoidal relaxation.

[PELVIS/SACRAL syndrome with livedoid haemangioma and amniotic band]. / PELVIS/SACRAL syndrome avec hémangiome livédoïde et bride amniotique.

BACKGROUND: PELVIS or SACRAL syndrome denotes the association of local haemangioma and malformation in the pelvic region. In this paper, we report a case noteworthy on account of the initially livedoid appearance of the haemangioma as well as associated amniotic banding of an upper limb. PATIENTS AND METHODS: A newborn male infant underwent left colostomy on the day of birth due to anal imperforation and anomalies of the external genital organs with sexual ambiguity. Examination of the skin and appendages revealed poorly delineated hypopigmentation in the sacrolumbar region and a fibrous groove around the right arm characteristic of amniotic band syndrome. Sacrolumbar and pelvic MRI scans revealed deviation towards the left of the last three sacral vertebrae with no medullary anomalies. Retrograde cystography showed a recto-uretral fistula. Progression of the infant's condition was marked by the appearance during the first month of a flat, violaceous, angiomatous, livedoid lesion in the middle of the buttocks and the perineum and a linear lesion on the rear aspect of the right lower limb. The skin biopsy of this lesion revealed a single capillary lobule at the dermal-hypodermal junction of non-specific appearance but with marked Glut1 expression by endothelial cells highly evocative of infantile haemangioma. DISCUSSION: Segmented haemangiomas are commonly associated with extracutaneous abnormalities. By analogy with PHACE syndrome, defined as association of segmented facial haemangioma with cerebral, ocular and cardio-aortic abnormalities, PELVIS/SACRAL syndrome denotes the association of segmented haemangioma of the loins (sacrolumbar region, buttocks or perineum=napkin haemangioma) with spinal dysraphia affecting the sacrolumbar spine, the terminal medullary cone, the genitourinary organs and the anal region to different degrees. Diagnosis of haemangioma associated with PELVIS/SACRAL syndrome may be delayed or complicated due to the macular, telangiectasic or livedoid appearance commonly seen. To our knowledge, there have been no reports to date of an association of amniotic banding with haemangioma or perineal dysraphia.