MARTENS, Wendy; WOLFS, Esther; STRUYS, Tom; POLITIS, Constantinus; BRONCKAERS, Annelies; LAMBRICHTS, Ivo
Dental pulp stem cells (DPSC) have been characterized as a multipotent stem cell population, with the ability to differentiate into mesodermal and neural cell lineages. Although 'de novo' expression of neural markers after differentiation is mostly considered as proof of differentiation, expression of these markers in undifferentiated DPSC is not well described. Therefore, an immunocytochemical analysis was performed to evaluate the neural marker expression of undifferentiated human DPSC (hDPSC) in in vitro cultures. Undifferentiated hDPSC uniformly expressed neural markers beta-III-tubulin, S100 protein and synaptophysin. A subset of the population showed a positive immune-reactivity for galactocerebroside, neurofilament and nerve growth factor...
Vandeputte, Caroline; Casteels, Cindy; Struys, Tom; Koole, Michel; van Veghel, Daisy; Evens, Nele; Gerits, Anneleen; Dresselaers, Tom; Lambrichts, Ivo; Himmelreich, Uwe; Bormans, Guy; Van Laere, Koen
Recent ex vivo and pharmacological evidence suggests involvement of the endocannabinoid system in the pathophysiology of stroke, but conflicting roles for type 1 and 2 cannabinoid receptors (CB1 and CB2) have been suggested. The purpose of this study was to evaluate CB1 and CB2 receptor binding over time in vivo in a rat photothrombotic stroke model using PET. CB1 and CB2 microPET imaging was performed at regular time-points up to 2 weeks after stroke using [F-18]MK-9470 and [C-11]NE40. Stroke size was measured using MRI at 9.4 T. Ex vivo validation was performed via immunostaining for CB1 and CB2. Immunofluorescent double...
HENDRIX, Sven; NELISSEN, Sofie; LEMMENS, Evi; VANGANSEWINKEL, Tim; VIDAL VERA, Pia; WILLEMS, Leen; Boato,F.; DOOLEY, Dearbhaile; Pejler, G.; Maurer, M.; Metz, Martin
Purpose/Objective: It becomes increasinglyclear that mast cells (MCs) are not only key players in allergic diseases (e.g.asthma), but seem to play a complex role in neuroinflammatory diseases such as multiple sclerosis and stroke. However, their role during and after mechanical CNS trauma is not clear. In the present study, we have investigated the effectsof MC-deficiency on the histological and clinical outcome after spinal cordhemisection at thoraic level T8 resulting
in a complete transection of the dorsomedial and ventral corticospinal tract. Functional recovery in SCI mice was tested with the Basso Mouse Scale. Spinal cord sections were analyzed by immunofluorescence. RTPCR and...
Moris, Brecht; Claesen, Luc; Sun, Yi; Politis, Constantinus
A method for the automated tracking of the
mandibular canal in Cone Beam Computed Tomography images
is presented. In contrast to most proposed methods a fully
automated method is presented including the detection of the
mental and mandibular foramen. Extraction of these points is
done by searching for high-contrast gaps in the mandible. The
path of the mandibular canal can then be tracked in between
these two points using a matching technique consisting of a
template function which maps spatial coordinates to a cost. The
robustness of the tracking is increased by recursively tracking
van Zwieten, K.J.; Narain, F.; Kosten, L.; De Munter, S.; Zoubova, I.; Schmidt, K.; Lamur, K.
Tracings of an in vivo opossum X-ray, displaying shank and foot, confirm that collum fibulae and spatium interosseum cruris are reliable landmarks to describe the non-sagittal hind-limb movements. Only since recently, quantitative measurements in higher primates, e.g. man, allow extrapolating these data to bipedal gait. In man, after take-off, just a short distinct foot eversion helps to clear the foot from the surface, mainly during the onset of sway.
Weyns, F.; Bringmans, T.; Vandevenne, J.; Daenekindt, T.; Van Goethem, A.; Wuyts, J.; Vanormelingen, L.; Vandersteen, M.
Clinical compression neuropathy caused by para-articular cysts is rare. Only recently, the unifying articular theory was proposed to clarify its true etiologic nature. The authors attribute 17 cases to this theory in order to illustrate the shift in the diagnostic and treatment protocol, and the possible impact on patient outcome. Eight intraneural and nine extraneural cysts were included. The proposed diagnostic protocol includes electromyography and ultrasound, followed by magnetic resonance imaging to characterize the cyst. The proposed treatment protocol consists of (1) ligation of the pedicle connecting the cyst with the afflicted joint, (2) decompression of the nerve and, when...
MARTENS, Wendy; BRONCKAERS, Annelies; HILKENS, Petra; GERVOIS, Pascal; POLITIS, Constantinus; LAMBRICHTS, Ivo
Stem cell-based therapies can be a future novel strategy to repair peripheral nerve injury, based on their multilineage differentiation potential and ability to produce and secrete neuro(trophic) factors. Recently, a possible transdifferentiation of MSC into SC have been demonstrated which had a positive effect on neuronal survival and neurite outgrowth. In this study, dental pulp stem cells (DPSC) are differentiated toward SC via a mix of growth factors. In addition the influence of secreted neurotrophic factors bt DPSC and SC-DPSC on neuronal outgrowth and survival is investigated. After 21 days of differentiation, the expression of SC-markers, GFAP, p75 and S100...
van Zwieten, Koos Jaap; Schmidt, Klaus; Kepa, Jacek; Zoubova, Irina; Zinkovsky, Anatoly
Beneficial effects by low frequency vibrations on muscle strength as in walking and running, and by medium frequency whole body vibration as during the application of electrovibrostimulation were demonstrated recently (Van Zwieten et al., 2007). Very low frequency vibrations (1-2 Hz), however, may evoke so-called kinetosis which is characterized by malaise, dizziness and nausea (Kepa, 2006). Large wind turbines can produce these infrasonic vibrations, as reported by Jung et al. (2008). Wind turbines should be constructed at least 1.5 km from residences (Chouard, 2006) and should stand not too close together.
de Jong, Lars; Engelborghs, Koen; VANDEVENNE, Jan; WEYNS, Frank
We present two cases of spontaneous intracerebellar migration of a pseudomeningocele. This is a rarely reported complication of posterior fossa surgery with possible life threatening cerebellar mass effect. The probable mechanism is a slow but progressive cerebrospinal fluid (CSF) movement (one-way valve mechanism) into the pseudomeningocele with secondary herniation or dissection through a weakened dura into the cerebellum causing progressive or acute cerebellar dysfunction. Evacuation and dural repair with or without CSF shunting or marsupialisation results in resolution of the symptoms.
van Zwieten, K.J.; Schmidt, K.P.
The so-called singer???s formant is a merge between at least two formants, possibly F3 and F4. We reconstructed some functional-anatomical phenomena in pronouncing the vowel /i/, by means of a crossed four-bar-linkage model simulating jaw motion in a sagittal plane. During uttering the high front vowel /i/ in ???Heed???, the tongue???s dorsum is lifted, so as to narrow the linguo-palatal port, while the velo-pharyngeal port simultaneously closes. Although Sundberg et al. (2007) presume individual preference in the amount of this velo-pharyngeal closing during the production of a singer???s formant, we rather interpret this as a tautening of the palatine aponeurosis...
Masui, Chris; Peters, Ilse; Jacobs, Inge; Maelstaf, Monique; Vandenreyt, Ingrid; Vandersteen, Marjan; Thys, Isabel; Saenen, Ilse; Lambrechts, Danny; Vandervorst, Carine; Vossen, G.
Reeds jaren wordt er in de Universiteit Hasselt aandacht besteed aan de bewaking van de studeerbaarheid van curricula. Dit vormt een belangrijk onderdeel van de interne kwaliteitszorg. Hierbij werden diverse technieken gebruikt. Vanaf 2001-2002 werd o.m. gewerkt met een tijdschrijfagenda. Het manueel verzamelen, ingeven en verwerken van de data was echter bijzonder arbeidsintensief. Hierdoor groeide de behoefte aan een systematische en elektronische vorm van studietijdbeheer. Dit project werd ingediend in het kader van de convenantfinanciering. Sinds januari 2003 is er een werkgroep opgericht met als doel de ontwikkeling van een elektronische applicatie en de bevordering van de verspreiding van deze...
Van Zwieten, Koos Jaap; Schmidt, Klaus P.; Geusens, Piet P.M.M.; De Munter, Stephanie; Kosten, Lauren; Hotterbeekx, An; Lambrichts, Ivo; Lippens, Peter L.; Adriaensens, Peter
Superficial and deep fiber bundles within the proper collateral ligament (PCL) of the finger's Proximal Inter Phalangeal (P.I.P.) joint(van Zwieten et al., 2011)are clearly visible in High Resolution MRI frontal and sagittal slices. Because these bundles are fully tautened during PIP flexion, and in view of their intercrossing, we could conceive the PIP joint as a crossed 4-bar linkage system. Introducing into this 4-bar linkage model numerical values, obtained after measurements in sagittal HR-MRI slices, allowed us to construct the curvatures of the only two articulating surfaces which can perform PIP flexion by rolling relative to each other without any...
Loske, Peter; Boato, Francesco; Hendrix, Sven; Piepgras, Johannes; Just, Ingo; Ahnert-Hilger, Gudrun; Hoeltje, Markus
C3 ADP-ribosyltransferase is a valuable tool to study Rho-dependent cellular processes. In the current study we investigated the impact of enzyme-deficient peptides derived from Clostridium botulinum C3 transferase in the context of neuronal process elongation and branching, synaptic connectivity, and putative beneficial effects on functional outcome following traumatic injury to the CNS. By screening a range of peptidic fragments, we identified three short peptides from C3bot that promoted axon and dendrite outgrowth in cultivated hippocampal neurons. Furthermore, one of these fragments, a 26-amino acid peptide covering the residues 156181 enhanced synaptic connectivity in primary hippocampal culture. This peptide was also...
Boato, Francesco; Hechler, Daniel; Rosenberger, Karen; Luedecke, Doreen; Peters, Eva M.; Nitsch, Robert; HENDRIX, Sven
Pro-inflammatory cytokines such as interleukin-1 beta (IL-1 beta) are considered to exert detrimental effects during brain trauma and in neurodegenerative disorders. Consistently, it has been demonstrated that IL-1 beta suppresses neurotrophin-mediated neuronal cell survival rendering neurons vulnerable to degeneration. Since neurotrophins are also well known to strongly influence axonal plasticity, we investigated here whether IL-1 beta has a similar negative impact on neurite growth. We analyzed neurite density and length of organotypic brain and spinal cord slice cultures under the influence of the neurotrophins NGF, BDNF, NT-3 and NT-4. In brain slices, only NT-3 significantly promoted neurite density and length....
Martens, W.; Wolfs, E.; Struys, T.; Politis, C.; Bronckaers, A.; Lambrichts, I.
DPSC have been characterized as a multipotent stem cell population, with the ability to differentiate into mesodermal and neural cell lineages. Although ???de novo??? expression of neural markers after differentiation is mostly considered as proof of differentiation, expression of these markers in undifferentiated DPSC is not well described. Therefore, an immunocytochemical analysis was performed to evaluate the neural marker expression of undifferentiated hDPSC in in vitro cultures. Undifferentiated hDPSC uniformly expressed neural markers b-III-tubulin, S100 and synaptophysin. A subset of the population showed a positive immune-reactivity for GalC, neurofilament and NGFRp75.
Furthermore, the location of possible stem cell niches, present in...
Verhaeghe, Wim Victor; Schepers, Serge; Sun, Yi; Orye, Johan; Vrielinck, Luc; Politis, Constantinus; Lakiere, Eva; De Temmerman, Griet
Purpose: A patient surviving after a metal projectile penetrates the sphenoid sinus is unusual.
Removing a foreign object from this region is challenging because of the difficult access and proximity
to delicate structures. The use of navigation-guided endoscopy makes the manipulation of the surgical
instruments near delicate structures safer and the procedure is minimally invasive.
Patient: The case of a 67 year old male who shot himself while cleaning his airgun is presented.
Results: A brain CT scan showed the projectile located at the base of the left sphenoid sinus. To prevent
infection and irritation and avoid secondary surgical damage, navigation-guided endoscopy was used
to remove the...
This study assessed the incidence, symptoms, diagnosis, and management of patients with life-threatening postoperative hemorrhage after Le Fort I osteotomy and surgically assisted rapid palatal expansion (SARPE). The medical records of 750 consecutive Le Fort I osteotomies and 376 consecutive SARPEs, both of which involved pterygomaxillary separation with a curved osteotome and a mallet, were prospectively analyzed. Two cases of life-threatening hemorrhage were observed in the Le Fort I osteotomy group, both initiated on the seventh postoperative day. Anterior and posterior nasal packing were only successful in one patient; the other patient required two embolizations for bleeding control (incidence of...
Sun, Y.; Vrielinck, L.; Schepers, S.; Politis, C.
To evaluate the transfer precision of the NobelProcera planning
system for oral implants, based on three-dimensional (3D) cone-beam
computed tomography (CBCT) images through stereolithographic (SLA) drill guides. The accuracy of navigation-based insertion of zygomatic implants was studied.
Sun, Y.; Vrielinck, L.; Schepers, S.; Politis, C.
Computer-aided treatment simulation is routinely applied in the ﬁeld
of orthognatic surgery. The digital fabrication of the intermediate
wafer remains a difﬁcult step because the occlusal surfaces must be
produced at high resolution (\50 lm). We present a novel method
that uses readily available software to plan and fabricate the surgical intermediate wafer.
Sun, Y.; Vrielinck, L.; Schepers, S.; Politis, C.
Purpose: To examine different registration methods combined with the BrainLab navigation system in bimaxillary orthognatic surgery.