Sellar angiolipomas: two case reports and a review of the literature

Angiolipomas are mesenchymal hamartomas composed of abnormal blood vessels and mature adipose tissue, most commonly found in the subcutaneous tissue of the extremities. Intracranial location is extremely rare, and only five cases have been described in the sellar region. We report on two patients that were initially diagnosed with pituitary adenomas that were postoperatively verified as angiolipomas. Sellar angiolipomas should be considered in the differential diagnosis of pituitary lesions due to the potential catastrophic bleeding during surgery. Preoperative diagnosis is very difficult; however, some MRI characteristics can help make an accurate diagnosis. Adequate MRI sequences should be used in the evaluation of pituitary lesions, as they can help optimize the microsurgical management.     

Anatomical Variations of the Bifid Mandibular Canal on Panoramic Radiographs in Citizens from Zagreb,Croatia

BackgroundThe bifid mandibular canal (BMC) is an anatomical variation with reported prevalence ranging from 0.08 to 65%. Identifying anatomical variations of mandibular canal is very important in order to prevent possible complications during oral surgical and other dental procedures.ObjectivesThe aim of this study was to determine the prevalence and to classify the morphology of BMCs using digital panoramic radiographs.Material and methodsA retrospective study was conducted that included 1008 digital panoramic radiographs (412 female and 596 male) used to identify the type of BMC. Panoramic radiographs were analyzed by three oral surgeons and one dentist, and BMCs were classified into six different types, 4 types according to Langlais et al. (types 1-4), and two new types (types 5 and 6) described by authors.ResultsThe prevalence of BMC was 4.66% (n=47), with no significant differences in gender between BMC types (P=0.947; χ²=0.74). The prevalence of type 1 BMC was 0.79% (n=8), type 2 2.08% (n=21), type 3 0.30% (n=3), type 4 0% (n=0), type 5 0.89% (n=9) and type 6 0.60% (n=6).ConclusionThis study revealed a relatively high prevalence of BMCs among Zagreb citizens. Furthermore, two new types of BMCs were described. These results stress the importance of a careful and thorough radiographic analysis prior to each invasive procedure in the mandible.     

Basal ganglia shrinkage without remarkable hippocampal atrophy in chronic aviremic HIV-positive patients

Conventional magnetic-resonance (MR) imaging is not sensitive enough in depicting subtle neurodegenerative changes that occur during chronic HIV infection with good peripheral viral suppression. The aim of this study was to compare brain volumes in HIV-positive subjects with age- and education-matched healthy controls with regard to influence of aging and immunologic parameters. An overall of 65 subjects (40 HIV-positive and 25 age-, gender-, and education-matched healthy subjects) underwent conventional MR imaging with three-dimensional sequence adequate for volumetric measurements. Volumes of specific brain regions were measured and compared between HIV-positive and healthy subjects using Student t test. Correlations between obtained brain volumes and immunologic parameters were determined using Pearson’s correlation test. Influence of age as a covariate was determined using ANCOVA test. Statistical value was set at p?<?0.05. Volumes of nucleus accumbens (p?=?0.003), putamen (p?=?0.003), and thalamus (p?=?0.046) were significantly decreased in HIV-positive subjects compared with healthy, while volumes of lateral ventricles were significantly increased (p?=?0.043). However, influence of age on atrophy was greater than presence of HIV infection in all observed volumes. Positive correlation of nadir CD4+ count and nucleus accumbens volume was obtained, as well as of therapy with lateral ventricle volumes. Volumes of putamen correlated negatively with duration of therapy. HIV-associated atrophic changes are visible in nucleus accumbens, putamen, and thalamus in neurocognitively asymptomatic stage, while no changes can be observed in the hippocampus, affected by other types of dementias. Under therapy, the influence of physiological aging on HIV-associated atrophy is greater than the presence of HIV infection per se.     

The role of adhesion molecules in atopic dermatitis

Adhesion molecules may play an important role in the homing of T-cell subsets into allergen-exposed skin of atopic individuals. The aim of this pilot study was to examine the expression of adhesion molecules in atopic dermatitis (AD) skin lesions. Biopsies were taken at acute skin lesions from 10 AD patients and 5 healthy controls, and were studied by immunohistocytochemistry for the expression of E-selectin, L-selectin, ICAM-1 and ICAM-3 on cells in the epidermis and dermis. Study results revealed all AD patients to express ICAM-1 (10/10) and ICAM-3 (10/10) in the dermis, and most of them to express E-selectin (9/10) and L-selectin (6/10) in the dermis, without expression of E- and L-selectins in the epidermis. Our results revealed a high expression of adhesion molecules, especially ICAM-1 and ICAM-3, in the skin lesions of AD patients, which may play an important role in the pathogenesis of AD, and these preliminary results may be of clinical relevance for the treatment of AD.     

Biomechanical stability analysis of transpedicular screws combined with sublaminar hook-rod system using the finite element method

AimTo develop and test a new posterior stabilization system by augmenting the posterior hook-rod system with screws and rods.MethodsA biomechanical analysis was performed using the finite element method. The anatomical structures were modeled based on computed tomography data. Instrumentation (hooks, rods, and screws) was modeled based on the data obtained by 3D scanning. The discretized model was verified by converging solutions and validated against data from a previously published experiment. A Th12-L1 spinal segment was modeled and modified by removing the body of the L1 vertebra (corpectomy) and the entire L1 vertebra (spondylectomy). The model was additionally modified by incorporating stabilization systems: i) posterior stabilization (transpedicular screws and rods); ii) combined posterior stabilization with sublaminar hooks; and iii) combined anterior (titanium cage) and posterior (sublaminar hooks) stabilization. The rotation angles in each group, and the strains on each part of the three stabilization constructs, were analyzed separately.ResultsThe combined anterior and posterior stabilization system was the stiffest, except in the case of lateral bending, where combined posterior stabilization was superior. Stress analysis showed that the posterior stabilization system was significantly unloaded when augmented with a hook-rod system. A significant strain concentration was calculated in the cranially placed hooks.ConclusionStiffness analysis showed comparable stiffness between the tested and proposed stabilization construct. Stress analysis showed luxation tendency of the cranially placed hooks, which would most likely lead to system failure.

Several factors are to be considered when deciding on the type of treatment of spine fractures: biomechanical stability, deformity, and neurological injury (1-3). The prevailing consensus among surgeons is to operate on unstable fractures, ie, fractures accompanied by neurological injury, with damage to all three vertebral columns, or if instability, deformity, or neurological deficit are imminent. The aims of surgical treatment are decompression of neural structures, biomechanical stability, and spinal deformity correction (4-8).Biomechanical stability is achieved by using stabilization systems; based on the application site they can be anterior, lateral, and posterior. Stabilization systems enable anatomical restitution, fusion, and fast recovery (9). Anchoring options for posterior stabilization systems include sublaminar hooks, sublaminar wires, and transpedicular screws. Sublaminar hooks and wires are traditionally combined with Harrington distraction rods, and transpedicular screws with rods or plates (10-12). The invention of the transpedicular screw with its three-columnar anchoring increased the possibility of anchorage loading and thereby of shortening the system; this all led to the birth of the posterior segmental stabilization system (2,12). Therefore, the current standard in thoracolumbar spine stabilization includes transpedicular screws combined with plates or rods (13). Combined anterior and posterior stabilization remains the method of choice for achieving stability in the treatment of a spinal column that has lost its ability of withstanding axial loading, eg, complete burst fracture that may include translation and rotation (2,14). A limitation of the combined anterior and posterior stabilization technique is its invasiveness (15).We aimed to test the hypothesis that the combined posterior stabilization system incorporating transpedicular screws, sublaminar hooks, and rods had comparable performance with regard to displacement and stability to the combined anterior and posterior stabilization in a virtual model of L1 corpectomy and spondylectomy.