Kaposi sarcoma in an HIV-negative Tunisian patient: A rare cause of metatarsalgia

AbstractBackgroundKaposi sarcoma (KS) is an angioproliferative neoplasm that is commonly associated with human herpes virus-8 (HHV-8) and human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). KS with osseous involvement is a rare occurrence, and is far more common in acquired immunodeficiency syndrome (AIDS)-related KS.Case presentationWe present a 32-year-old Tunisian man, HIV negative, who presented with a 4-year history of atraumatic mechanical metatarsalgia that progressively worsened with a limping gait. Physical examination revealed marked symmetrical forefoot lymphedema and a painful restricted left knee joint movement. Physical examination showed purple-blue plaques and nodules on the feet and ankles. Serologic tests for HIV and syphilis were negative. Plain radiography of the feet revealed numerous small lytic lesions. There were also scattered lytic lesions in the metaphysis of the proximal tibia and fibula. Osteolysis was predominantly left. Magnetic resonance imaging of the feet showed abnormal bone marrow signal of metatarsals and phalanges. Skin lesion biopsy yielded the diagnosis of Kaposi sarcoma. The disease was managed with chemotherapy including vinblastine.ConclusionIn a patient presenting with metatarsalgia without a commonly detected cause, it is mandatory to search for other lesions that may point to a rare diagnosis as KS which is famous for involvement of the metatarsal bone

Prevalence of hemoglobin variants in a diabetic population at high risk of hemoglobinopathies and optimization of HbA1c monitoring by incorporating HPLC in the laboratory workup

Background: In Tunisia, diabetes mellitus and hemoglobinopathies are major public health problems. Glycated hemoglobin (HbA1c) is  recommended for long-term monitoring of diabetes mellitus, but the presence of hemoglobin variants may interfere with HbA1c measurement. The aim was to determine the prevalence of hemoglobin variants in Tunisian diabetics and optimize the monitoring of diabetics using HbA1c.Methods: The study enrolled 9,792 Tunisian diabetic patients. HbA1c was measured by cation-exchange highpressure liquid chromatography (HPLC). All the chromatograms were analyzed for the presence of Hbvariants.Results: We identified 228 cases (2.33%) of Hb variants with D-10 HPLC (Bio-Rad): 191 with HbA/S trait, 27 with HbA/C trait, and 10 hemoglobin variants with the mention ‘Variant-Window’ on the chromatograms and subsequently identified as HbA/S on Variant I HPLC (Bio-Rad). Thus, the prevalence of HbS was 2.05%. We did not find any homozygous variant. All HbA1c results were reported to the treating physician.Conclusions: To evaluate glycated hemoglobin in populations with a high prevalence of hemoglobinopathies, we should use the HPLC method, which is easy, economical, and reliable. Based on an algorithm, hemoglobinvariants visualized on HPLC should be reported to the physician to improve the management of patients.Keywords: hemoglobinopathies; HbA1c; HPLC; diabetes mellitus; prevalence; Tunisi

Knee extension strength in obese and nonobese male adolescents

The aim of the present study was to compare “absolute” and “relative” knee extension strength between obese and nonobese adolescents. Ten nonobese and 12 severely obese adolescent boys of similar chronological age, maturity status, and height were compared. Total body and regional soft tissue composition were determined using dual-energy X-ray absorptiometry (DXA). Knee extensors maximum voluntary contraction (MVC) torque was measured using an isometric dynamometer at a knee angle of 60° (0° is full extension). Absolute MVC torque was significantly higher in obese adolescents than in controls. However, although MVC torque expressed per unit of body mass was found to be significantly lower in obese adolescent boys, no significant difference in MVC torque was found between groups when normalized to fat-free mass. Conversely, when correcting for thigh lean mass and estimated thigh muscle mass, MVC torque was significantly higher in the obese group (17.9% and 22.2%, respectively; P <0.05). To conclude, our sample of obese adolescent boys had higher absolute and relative knee extension strength than our nonobese controls. However, further studies are required to ascertain whether or not relative strength, measured with more accurate in vivo methods such as magnetic resonance imaging, is higher in obese adolescents than in nonobese controls

A New Approach To Light-Weight Ablators Analysis: From Micro-Tomography Measurements to Statistical Analysis and Modeling

The morphology characteristics and ablation behavior of a highly porous carbon fiber preform are studied using a combined experimental/numerical approach. Morphological characterization of the three-dimensional structure of the material is performed by hard X-rays synchrotron micro-tomography at the Advanced Light Source of Lawrence Berkeley National Laboratory. The resulting micro-tomography voxels are used to compute geometrical properties of the carbon preform, like porosity, specific surface area and tortuosity, that are otherwise indirectly measured through experimental techniques. The reconstructed volumes are used to build a computational grid for numerical simulations of the fibers\u27 ablation. By modeling the diffusion of oxygen through the porous medium using Lagrangian methods, and the oxidation at the carbon fibers\u27 surface using a reactivity model, the ablation of the carbon fibers are simulated for a range of Thiele numbers. It is shown that in the diffusion limited regime (large Thiele number), the ablation of the fibers occurs at the surface of the material. In the reaction limited regime (low Thiele number), the oxygen penetrates into the fibers, resulting in volumetric ablation and high material spallation

Spondylodiscite tuberculeuse : 12 ans d'expérience dans un centre hospitalier en Tunisie

Objectifs : Décrire les particularités épidémiologiques, cliniques et paracliniques des spondylodiscites tuberculeuses et déterminer les facteurs prédictifs d’une évolution défavorable. Patients et Méthode: Etude rétrospective sur une période de 12 ans. Le diagnostic a été porté sur des preuves bactériologiques, anatomopathologiques ou sur un faisceau d’arguments. Résultats : Il s’agissait de 49 patients (26F/23H), âgés en moyenne de 51,84 ans. Le délai moyen de diagnostic était de 6,65 mois. Un facteur prédisposant à l’infection a été relevé chez 38,7% des patients. L’étage lombaire était le plus touché (67,3%). L’imagerie par résonnance magnétique était pathologique dans tous les cas où elle a été effectuée. Le diagnostic de certitude a été porté dans 9 cas sur une preuve histologique. La ponction biopsie disco-vertébrale a permis de confirmer le diagnostic dans 6/36 cas. Tous les patients ont reçu un traitement anti-tuberculeux d’une durée moyenne de 13,59 mois associé à un geste interventionnel dans 8 cas. L’évolution était favorable dans 84,2% des cas. Nous avons identifiés quatre facteurs prédictifs d’une évolution défavorable: une hyperleucocytose initiale ≥11500 éléments/mm3 (p=0,031), la présence d’abcès ou de collection à l’imagerie (p=0,018); un tassement vertébral à l’IRM (p=0,018) et l’existence de déformation osseuse avant correction chirurgicale (p<0,001). Conclusion: La spondylodiscite tuberculeuse devrait être suspectée devant toute rachialgie inflammatoire. Une prise en charge précoce est la clé pour éviter les complications neurologiques et ostéo-articulaires

Interactive Visual Exploration of 3D Mass Spectrometry Imaging Data Using Hierarchical Stochastic Neighbor Embedding Reveals Spatiomolecular Structures at Full Data Resolution

Technological advances in mass spectrometry imaging (MSI) have contributed to growing interest in 3D MSI. However, the large size of 3D MSI data sets has made their efficient analysis and visualization and the identification of informative molecular patterns computationally challenging. Hierarchical stochastic neighbor embedding (HSNE), a nonlinear dimensionality reduction technique that aims at finding hierarchical and multiscale representations of large data sets, is a recent development that enables the analysis of millions of data points, with manageable time and memory complexities. We demonstrate that HSNE can be used to analyze large 3D MSI data sets at full mass spectral and spatial resolution. To benchmark the technique as well as demonstrate its broad applicability, we have analyzed a number of publicly available 3D MSI data sets, recorded from various biological systems and spanning different mass-spectrometry ionization techniques. We demonstrate that HSNE is able to rapidly identify regions of interest within these large high-dimensionality data sets as well as aid the identification of molecular ions that characterize these regions of interest; furthermore, through clearly separating measurement artifacts, the HSNE analysis exhibits a degree of robustness to measurement batch effects, spatially correlated noise, and mass spectral misalignment

Visceral leishmaniasis in 26 HIV-negative adults

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis is a notifiable parasitic disease that had increased in incidence in our region on the past few years. It is common in children. In adults, it occurs more on a background of immunodeficiency, and frequently with incomplete clinical manifestations, making the diagnosis complicated.</p> <p>Findings</p> <p>The aim of our study is to reveal different features of visceral leishmaniasis in adults, through the analysis of its epidemiological, clinical and biological parameters, in a group of 26 patients. No one was infected with HIV or under immunosuppressive therapy Clinical presentation was generally conservative, but there was few differences in adults compared to children, concerning both the clinical symptoms and the laboratory parameters. Diagnosis was provided by direct examination of bone marrow smears in 24 cases (sensitivity 92%), and anti-leishmanial serology in the others.</p> <p>Conclusion</p> <p>We should think to the diagnosis of VL even if the patient is not known immunocompromised, and even if the clinical is incomplete, to avoid a delay of care which can lead to serious complications.</p

A unique subset of glycolytic tumour-propagating cells drives squamous cell carcinoma

Head and neck squamous cell carcinoma (SCC) remains among the most aggressive human cancers. Tumour progression and aggressiveness in SCC are largely driven by tumour-propagating cells (TPCs). Aerobic glycolysis, also known as the Warburg effect, is a characteristic of many cancers; however, whether this adaptation is functionally important in SCC, and at which stage, remains poorly understood. Here, we show that the NAD+-dependent histone deacetylase sirtuin 6 is a robust tumour suppressor in SCC, acting as a modulator of glycolysis in these tumours. Remarkably, rather than a late adaptation, we find enhanced glycolysis specifically in TPCs. More importantly, using single-cell RNA sequencing of TPCs, we identify a subset of TPCs with higher glycolysis and enhanced pentose phosphate pathway and glutathione metabolism, characteristics that are strongly associated with a better antioxidant response. Together, our studies uncover enhanced glycolysis as a main driver in SCC, and, more importantly, identify a subset of TPCs as the cell of origin for the Warburg effect, defining metabolism as a key feature of intra-tumour heterogeneity