Ocular hypertension in patients with active thyroid-associated orbitopathy: a predictor of disease severity,particularly of extraocular muscle enlargement

Graefe's Archive for Clinical and Experimental Ophthalmology - The purpose was to ascertain if any relation exists between the elevated intraocular pressure (IOP) in patients with...     

Death in consequence of late failure of endoscopic third ventriculostomy

Introduction Late failure of originally successful endoscopic third ventriculostomy (ETV) is considerably less common than failure of ventriculo-peritoneal (V-P) shunt in treatment of hydrocephalus. Death in consequence of late ETV failure is a very rare complication, so far having been mentioned in literature in 13 patients only. Case report We present the case of an 11-year-old girl who died in consequence of ETV failure 26 months after the endoscopic procedure. Histopathology proved the closure of stoma by gliotic tissue. Conclusion We can assume that reduced compliance of the ventricular wall in long-term V-P shunt, aqueductal stenosis as a cause of hydrocephalus as well as rapid onset of clinical symptoms prior to ETV might be the cause of acute onset of intracranial hypertension after late ETV failure. Potential prevention of sudden death seems to be the implantation of subcutaneous reservoir during the endoscopic procedure, which allows simple and rapid reduction of intraventricular pressure.     

Cost of digging is determined by intrinsic factors rather than by substrate quality in two subterranean rodent species

Searching for food by extensive digging is one of the most important aspects of life of subterranean rodents. We studied the effect of extrinsic (substrate quality) and intrinsic factors (sex and body mass) upon the cost of burrowing, expressed as digging metabolic rate (DMR) in two African mole-rat species (Bathyergidae, Rodentia) with distinct social structures. The sexually dimorphic giant mole-rat (Fukomys mechowii) is a highly social species, whereas the almost monomorphic silvery mole-rat (Heliophobius argenteocinereus) is a solitary bathyergid. Burrowing in F. mechowii was more costly (DMR was greater) than in H. argenteocinereus, but there was no difference in burrowing speed between both species. DMR within a particular species was dependent upon body mass, but independent of sex. Different substrate quality had no effect upon DMR in either species, yet it affected burrowing speed. We conclude that less effective digging in F. mechowii can be compensated by the joint workforce of other family members. Alternatively, H. argenteocinereus, being a more effective digger, can afford a solitary way of life.     

Modeling and Testing of Flexible Structures with Selected Planar Patterns Used in Biomedical Applications

Flexible structures (FS) are thin shells with a pattern of holes. The stiffness of the structure in the normal direction is reduced by the shape of gaps rather than by the choice of the material based on mechanical properties such as Young’s modulus. This paper presents virtual prototyping of 3D printed flexible structures with selected planar patterns using laboratory testing and computer modeling. The objective of this work is to develop a non-linear computational model evaluating the structure’s stiffness and its experimental verification; in addition, we aimed to identify the best of the proposed patterns with respect to its stiffness: load-bearing capacity ratio. Following validation, the validated computational model is used for a parametric study of selected patterns. Nylon—Polyamide 12—was chosen for the purposes of this study as an appropriate flexible material suitable for 3D printing. At the end of the work, a computational model of the selected structure with modeling of load-bearing capacity is presented. The obtained results can be used in the design of external biomedical applications such as orthoses, prostheses, cranial remoulding helmets padding, or a new type of adaptive cushions. This paper is an extension of the conference paper: “Modeling and Testing of 3D Printed Flexible Structures with Three-pointed Star Pattern Used in Biomedical Applications” by authors Repa et al.     

Clinical results and development of heterotopic ossification in total cervical disc replacement during a 4-year follow-up

Cervical total disc replacement (CTDR) aims to decrease the incidence of adjacent segment disease through motion preservation in the operated disc space. Ongoing data collection and increasing number of studies describing heterotopic ossification (HO) resulting in decreased mobility of implants, forced us to carefully evaluate our long-term clinical and morphological results of patients with CTDR. We present the first 54 consecutive patients treated with 65 ProdiscC™ prostheses during a 12-month period (2/2004–3/2005). All patients signed an informed consent and were included in prospective long-term study approved by hospital ethical committee. The 1- and 2-year follow-up analysis were available for all patients included and 4-year results for 50 patients (60 implants). Clinical (neck disability index-NDI, visual analog scale-VAS) and radiological follow-up was conducted at 1-, 2- and 4-years after the procedure. The Mehren/Suchomel modification of McAfee scale was used to classify the appearance of HO. Mean preoperative NDI was 34.5%, VAS for neck pain intensity 4.6 and VAS for arm pain intensity 5.0. At 1-, 2- and 4-year follow-up, the mean NDI was 30.7, 27.2, and 30.4, mean VAS for neck pain intensity 2.5, 2.1 and 2.9 and mean VAS for arm pain intensity pain 2.2, 1.9 and 2.3, respectively. Significant HO (grade III) was present in 45% of implants and segmental ankylosis (grade IV) in another 18% 4 years after intervention. This finding had no clinical consequences and 92% of patients would undergo the same surgery again. Our clinical results (NDI, VAS) are comparable with fusion techniques. Although, advanced non-fusion technology is used, a significant frequency of HO formation and spontaneous fusion in cervical disc replacement surgery must be anticipated during long-term follow-up.     

Osteoadherin is Upregulated by Mature Osteoblasts and Enhances Their In Vitro Differentiation and Mineralization

During the process of differentiation, osteoblasts commit through strictly controlled checkpoints under the influence of several growth factors, cytokines, and extracellular matrix (ECM) proteins. The mineralized tissue-specific ECM component osteoadherin (OSAD) belongs to the small leucine-rich repeat protein family of proteoglycans. Proteoglycans modulate cellular behavior either through the attached glycosaminoglycan chains or by direct protein–protein interactions via the core protein sequences. Leucine-rich repeats have been shown to directly interact with cell-surface receptors such as epidermal growth factor receptor, blocking its ability to bind its ligand. In the present study, we investigated the influence of OSAD on the behavior and maturation of MC3T3E1 osteoblasts. OSAD overexpression and repression clones were created by stably transfecting with plasmids coding for either mouse OSAD cDNA or small-hairpin RNA, targeted against mouse OSAD. Overexpression of OSAD resulted in an increase of osteoblast differentiation features, such as increased alkaline phosphatase (ALP) activity and increased in vitro mineralization, as well as reduced proliferation and migration. Bone sialoprotein (BSP) levels were unchanged, while upregulation of osteocalcin (OC) and osteoglycin (OGN) was observed. Conversely, repression of OSAD expression resulted in increased cell proliferation and migration. BSP and OC were unaffected, while OGN was downregulated. ALP activity was reduced, though no change in in vitro mineralization was observed. We conclude that OSAD overexpression enhanced the differentiation and maturation of osteoblasts in vitro.     

Potential employment of non-silica-based stationary phases in pharmaceutical analysis

The absolute majority of the HPLC applications use silica-based columns for the separation of active substance and its impurities. However, stationary phases based on metal oxides appear as an interesting alternative. The aim of our study was to investigate the potential utilization of metal oxide-based stationary phases in analytical evaluation of ondansetron and its five pharmacopoeial impurities. In our study commercially available ZrO₂-based columns (e.g. Zr-PBD, Zr-PS, Zr-C18) and TiO₂-based column were used. The effect of an organic modifier (type and ratio), a buffer (type, pH and concentration) and the influence of temperature was investigated. The separation of ondansetron and its five pharmacopoeial impurities was successfully accomplished on a Zirchrom^®-PBD column using a mobile phase consisting of acetonitrile-ammonium phosphate (25 mM, pH 7.0) (18:82, v/v). Detection was performed at 216 nm and the analysis was completed within 7.5 min. The paper proves metal oxide-based stationary phases as an alternative to classical silica-based stationary phases in pharmaceutical analysis.