A comparative study on the anti-inflammatory effects of single oral doses of naproxen and its hydrogen sulfide (H2S)-releasing derivative ATB-346 in rats with carrageenan-induced synovitis

BACKGROUND: Non-steroidal antiinflammatory drugs (NSAIDs) are the most commonly prescribed agents for arthritic patients, although gastric effects limit their long-term use. Considering the reported gastric safety of hydrogen sulfide (H2S)-releasing NSAIDs, in addition to the anti-inflammatory effects of H2S administration to rats with synovitis, we decided to evaluate the effects of the H2S-releasing naproxen derivative ATB-346 in this animal model. METHODS: Male Wistar rats were anesthetized with inhalatory halothane and pre-treated with equimolar oral doses of either naproxen (0.3, 1, 3 or 10 mg/kg) or ATB-346 (0.48, 1.6, 4.8, or 16 mg/kg) 30 min before the i.art. injection of 7.5 mg of carrageenan (CGN) into the right knee joint cavity. Joint swelling and pain score were assessed after 1, 3 and 5 h, and tactile allodynia after 2 and 4 h. After the last measurement, the joint cavity lavages were performed for counting of the recruited leukocytes. The drugs (at the highest doses) were also tested for their gastric effects by evaluating macroscopical damage score and neutrophil recruitment (measured as myeloperoxidase - MPO activity) in the stomachs 5 h after administration of the drugs. In addition, the serum naproxen pharmacokinetic profiles of both compounds, administered at the highest equimolar doses, were obtained during the first 6 h after dosing. RESULTS: At the two highest tested doses, both naproxen and ATB-346 reduced edema and pain score (measured 3 and 5 h after CGN; P < 0.001). Tactile allodynia was similarly inhibited by ~45% 4 h after CGN by both naproxen (at 1, 3 and 10 mg/kg) and ATB-346 (at 1.6 and 4.8 mg/kg; P < 0.001), as well as leukocyte infiltration. Naproxen (but not ATB-346) induced significant gastric damage and, despite the increased gastric MPO activity by ~130% in the naproxen-, but not in the ATB-346-treated rats, this effect was of no statistical significance. CONCLUSION: The presence of a H2S-releasing moiety in the ATB-346 structure does not impair the antiinflammatory activity of the parent compound in rats with CGN-induced synovitis. In addition, released H2S may account for the absence of deleterious gastric effects, thus making of ATB-346 a potentially useful therapeutic alternative to traditional naproxen for treatment of patients with arthritis.

Mechanosensitivity in the myenteric plexus of the guinea pig ileum

The enteric nervous system regulates autonomously from the central nervous system all the reflex pathways that control blood flow, motility, water and electrolyte transport and acid secretion. The ability of the gut to function in isolation is one of the most intriguing phenomenons in neurogastroenterology. This requires coding of sensory stimuli by cells in the gut wall. Enteric neurons are prominent candidates to relay mechanosensitivity. Surprisingly, the identity of mechanosensitive neurons in the enteric nervous system as well as the appropriate stimulus modality is unknown despite the evidence that enteric neurons respond to sustained distension. Objectives: The aim of our study was to record from mechanosensitive neurons using physiological stimulus modalities. Identification of sensory neurons is of central importance to understand sensory transmission under normal conditions and in gut diseases associated with sensorimotor dysfunctions, such as Irritable Bowel Syndrome. Only then it will be possible to identify novel targets that help to normalise sensory functions. Methods: We used guinea-pig ileum myenteric plexus preparations and recorded responses of all neurons in a given ganglion with a fast neuroimaging technique based on voltage sensitive dyes. To evoke a mechanical response we used two different kinds of stimuli: firstly we applied a local mechanical distortion of the ganglion surface with von Frey hair. Secondarily we mimic the ganglia deformation during physiological movements of myenteric ganglia in a freely contracting ileal preparation. We were able to reliably and reproducibly mimic this distortion by intraganglionic injections of small volumes of oxygenated and buffered Krebs solution using stimulus parameters that correspond to single contractions. We also performed in every ganglion tested, electrical stimulations to evoke fast excitatory postsynaptic potentials. Immunohistochemistry reactions were done with antibodies against Calbindin and NeuN, considered markers for sensory neurons. Results: Recordings were performed in 46 ganglia from 31 guinea pigs. In every ganglion tested we found from 1 to 21 (from 3% to 62%) responding cells with a median value of 7 (24% of the total number of neurons). The response consisted of an almost instantaneous spike discharge that showed adaptation. The median value of the action potential frequency in the responding neurons was 2.0 Hz, with a recording time of 1255 ms. The spike discharge lasted for 302 ± 231 ms and occurred only during the initial deformation phase. During sustained deformation no spike discharge was observed. The response was reproducible and was a direct activation of the enteric neurons since it remained after synaptic blockade with hexamethonium or ω-conotoxin and after long time perfusion with capsaicin. Muscle tone appears not to be required for activation of mechanosensory neurons. Mechanosensory neurons showed a response to mechanical stimulation related to the stimulus strength. All mechanosensory neurons received fast synaptic inputs. There was no correlation between mechanosensitivity and Calbindin-IR and NeuN-IR (44% of mechanosensitive neurones Calb-IR-/NeuN-IR-). Conclusions: We identified mechanosensitive neurons in the myenteric plexus of the guinea pig ileum which responded to brief deformation. These cells appear to be rapidly accommodating neurons which respond to dynamic change. All mechanosensitive neurons received fast synaptic input suggesting that their activity can be highly modulated by other neurons and hence there is a low stimulus fidelity which allows adjusting the gain in a sensory network. Mechanosensitivity appears to be a common feature of many enteric neurons belonging to different functional classes. This supports the existence of multifunctional enteric neurons which may fulfil sensory, integrative and motor functions.

Isotope geochemical and geochronologic studies of basement units in the Central Western Carpathians (Slovakia)

In dieser Arbeit werden geochronologische und isotopen-geochemische Daten zur Entwicklung der Zentralen Westlichen Karpathen präsentiert. Die Karpathen bilden die östliche Fortsetzung der Alpen und können in drei Alpine Grundgebirgsdecken unterteilt werden, von denen zwei, die Veporische und die Gemerische, bearbeitet wurden. In der Veporischen Einheit wurden polymetamorphe Grundgebirgseinheiten untersucht, um deren genaue Altersstellung zu definieren und sie isotopengeochemisch zu klassifizieren. Dagegen wurde in der der Gemerischen Einheit, welche die Veporische Einheit überlagert, ein spezialisierter S-Typ Granit im Detail untersucht, um die petrogenetischen Prozesse, die zur magmatischen Entwicklung dieses Granits geführt haben, zu identifizieren. U-Pb Datierungen an Zirkonen der Veporischen Grundgebirgseinheiten zeigen für die gesamte Veporische Einheit ordovizische Entsehungsalter an (440-470 Ma). Diese Datierungen revidieren publizierte kambrische Entstehungsalter dieses Grundgebirges. Die Isotopensignatur (epsilon Nd und 87Sr/86Sr) der ordovizischen Grundgebirgseinheiten, bestehend aus stark überprägten Amphiboliten und Gneissen, ist von der Signatur der sich im Norden anschliessenden Tatrischen Einheit gut unterscheidbar. Die Bleiisotopenzusammensetzung dieser Gesteine ist stark krustal geprägt und überschneidet sich mit der der Tatrischen Einheit. Zusammen mit den T-DM Altern sind diese Einheiten vergleichbar mit prävariskischen Einheiten der Alpen. Somit kann das ordovizische Grundgebirge zu den peri-Gondwana Terranen gezählt werden, die an einem aktiven Kontinentalrand im Norden von Gondwana gebildet wurden. In den Gesteinen der Veporischen Einheit wurde im Weiteren eine starke metamorphe überprägung und intensiver felsischer Magmatismus karbonischen Alters erkannt (320-350 Ma). Dieses Ereignis ist zeitgleich mit dem Magmatismus, welcher hauptsächlich in der sich im Norden anschliessenden Tatrischen Einheit beobachtet wird. Dieser gehört der variskischen Orogenese an. Intensive alpine Deformation und Metamorphose konnte in der südlichen Veporischen Einheit anhand der Einzelzirkondatierungen und der Isotopendaten der ordovizischen Einheiten nachgewiesen werden. Am Dlha Dolina Granit in der Gemerischen Einheit können starke Fraktionierungs- und Auto-Metasomatose-Effekte beobachtet werden. Durch die magmatische Fraktionierung wird eine Anreicherung der SEE erzeugt, wogegen die Metasomatose die SEE stark verarmt. Es kommt sogar zur Ausbildung eines Tetraden Effektes im SEE Muster, welche den starken Einfluss von Fluiden während der spät-magmatischen Phase belegt. Gesamtgesteins Pb-Pb Daten beschränken das minimale Intrusionsalter dieses Granites auf 240 Ma. Dieses Alter ist in guter übereinstimmung mit den Sr-Isotopendaten der magmatisch dominierten Gesteine, wohingegen die stark metasomatisch geprägten Gesteine ein zu radiogenes 87Sr/86Sri aufweisen. Während dieser Arbeit wurde intensiv mit der Blei-Isotopenzusammensetzung von Gesamtgesteinsproben gearbeitet. Um die Auswertung dieser Daten optimieren zu können wurde ein Computerscript für das GPL Programm Octave erstellt. Die Hauptaufgabe dieses Scripts besteht darin, Regressionen für geochronologische Anwendungen gemäss York (1969) zu berechnen. Ausserdem können mu und kappa-Werte für diese Regressionen berechnet und eine Hauptkomponentenanalyse, welche hilfreich für den Vergleich von zwei Datensätzen ist, durchgeführt werden. Am Ende der vorliegenden Arbeit wird die analytische Methode für einen Mikrowellen beschleunigten Säureaufschluss von granitoidem Material zur Bestimmung der Sr- und Nd-Isotopenzusammensetzung und der Elementkonzentrationen vorgestellt. Diese kombinierte Methode nutzt ein TIMS für die Sr und Nd Isotopenmessungen und eine Einzelkollektor-ICPMS zur Bestimmung der SEE, Rb und Sr Konzentrationen, welche mithilfe von relativen Sensitivitätsfaktoren gegenüber einem internen Standard quantifiziert werden. Diese Methode wird durch Messungen von internationalen Referenzmaterialien bewertet. Die Ergebnisse zeigen eine Reproduzierbarkeit von <10% für die Elementkonzentrationen und von <5% für Elementverhältnisse.

Geochronological and structural evolution of the western and central Kaoko Belt in NW Namibia

This thesis focusses on the tectonic evolution and geochronology of part of the Kaoko orogen, which is part of a network of Pan-African orogenic belts in NW Namibia. By combining geochemical, isotopic and structural analysis, the aim was to gain more information about how and when the Kaoko Belt formed. The first chapter gives a general overview of the studied area and the second one describes the basis of the Electron Probe Microanalysis dating method. The reworking of Palaeo- to Mesoproterozoic basement during the Pan-African orogeny as part of the assembly of West Gondwana is discussed in Chapter 3. In the study area, high-grade rocks occupy a large area, and the belt is marked by several large-scale structural discontinuities. The two major discontinuities, the Sesfontein Thrust (ST) and the Puros Shear Zone (PSZ), subdivide the orogen into three tectonic units: the Eastern Kaoko Zone (EKZ), the Central Kaoko Zone (CKZ) and the Western Kaoko Zone (WKZ). An important lineament, the Village Mylonite Zone (VMZ), has been identified in the WKZ. Since plutonic rocks play an important role in understanding the evolution of a mountain belt, zircons from granitoid gneisses were dated by conventional U-Pb, SHRIMP and Pb-Pb techniques to identify different age provinces. Four different age provinces were recognized within the Central and Western part of the belt, which occur in different structural positions. The VMZ seems to mark the limit between Pan-African granitic rocks east of the lineament and Palaeo- to Mesoproterozoic basement to the west. In Chapter 4 the tectonic processes are discussed that led to the Neoproterozoic architecture of the orogen. The data suggest that the Kaoko Belt experienced three main phases of deformation, D1-D3, during the Pan-African orogeny. Early structures in the central part of the study area indicate that the initial stage of collision was governed by underthrusting of the medium-grade Central Kaoko zone below the high-grade Western Kaoko zone, resulting in the development of an inverted metamorphic gradient. The early structures were overprinted by a second phase D2, which was associated with the development of the PSZ and extensive partial melting and intrusion of ~550 Ma granitic bodies in the high-grade WKZ. Transcurrent deformation continued during cooling of the entire belt, giving rise to the localized low-temperature VMZ that separates a segment of elevated Mesoproterozoic basement from the rest of the Western zone in which only Pan-African ages have so far been observed. The data suggest that the boundary between the Western and Central Kaoko zones represents a modified thrust zone, controlling the tectonic evolution of the Kaoko belt. The geodynamic evolution and the processes that generated this belt system are discussed in Chapter 5. Nd mean crustal residence ages of granitoid rocks permit subdivision of the belt into four provinces. Province I is characterised by mean crustal residence ages <1.7 Ga and is restricted to the Neoproterozoic granitoids. A wide range of initial Sr isotopic values (87Sr/86Sri = 0.7075 to 0.7225) suggests heterogeneous sources for these granitoids. The second province consists of Mesoproterozoic (1516-1448 Ma) and late Palaeo-proterozoic (1776-1701 Ma) rocks and is probably related to the Eburnian cycle with Nd model ages of 1.8-2.2 Ga. The eNd i values of these granitoids are around zero and suggest a predominantly juvenile source. Late Archaean and middle Palaeoproterozoic rocks with model ages of 2.5 to 2.8 Ga make up Province III in the central part of the belt and are distinct from two early Proterozoic samples taken near the PSZ which show even older TDM ages of ~3.3 Ga (Province IV). There is no clear geological evidence for the involvement of oceanic lithosphere in the formation of the Kaoko-Dom Feliciano orogen. Chapter 6 presents the results of isotopic analyses of garnet porphyroblasts from high-grade meta-igneous and metasedimentary rocks of the sillimanite-K-feldspar zone. Minimum P-T conditions for peak metamorphism were calculated at 731±10 °C at 6.7±1.2 kbar, substantially lower than those previously reported. A Sm-Nd garnet-whole rock errorchron obtained on a single meta-igneous rock yielded an unexpectedly old age of 692±13 Ma, which is interpreted as an inherited metamorphic age reflecting an early Pan-African granulite-facies event. The dated garnets survived a younger high-grade metamorphism that occurred between ca. 570 and 520 Ma and apparently maintained their old Sm-Nd isotopic systematics, implying that the closure temperature for garnet in this sample was higher than 730 °C. The metamorphic peak of the younger event was dated by electronmicroprobe on monazite at 567±5 Ma. From a regional viewpoint, it is possible that these granulites of igneous origin may be unrelated to the early Pan-African metamorphic evolution of the Kaoko Belt and may represent a previously unrecognised exotic terrane.

Characterization of igneous terranes by zircon dating: implications for the UHP relicts occurrences and suture identification in the Central Rhodope, Northern Greece

One of the key for the understanding of an orogenic belt is the characterization of the terranes involved and the identification of the suture(s) separating crustal blocks: these are essential information for large-scale paleo-reconstructions. In addition, the structural relationships between the terranes involved in the collisional processes and the eventual UHP relicts may provide first order inputs to exhumation models of subducted rocks. The structure of the Rhodope Massif (northern Greece and southern Bulgaria) results from the stacking of high-grade nappes during a continental collision, which age is comprised between Latest-Jurassic and Early-Cenozoic. UHP and HP relicts, associated with oceanic and ultramafic material, suggest the presence of a dismembered suture zone within the massif. The location of this suture remains unclear; furthermore, up to now, the UHP and eclogitic localities represent isolated spots and no synthesis on their structural position within the massif has been proposed. The first aim of this work is to define the relationships between HP-UHP relicts, crustal blocks, shear zones and amphibolitic material. To achieve this objective, we characterized the accreted blocks in terms of protoliths ages of the orthogneisses mainly along two cross sections on the Greek part of the belt. Geochemical affinities of meta-igneous rocks served as a complementary tool for terrane characterization and geodynamic interpretation. Single-zircon Pb-Pb evaporation and zircon U-Pb SHRIMP dating of orthogneiss protoliths define two groups of intrusion-ages: Permo-Carboniferous and Late Jurassic-Early Cretaceous. Structurally, these two groups correspond to distinct units: the Late Jurassic gneissic complex overthrusts the one bearing the Permo-Carboniferous orthogneisses. Mylonites, eclogites, amphibolites of oceanic affinities, and UHP micaschists, mark a “melange” zone, intensively sheared towards the SW, which separates the two units. Thus, we interpret them as two distinct terranes, the Rhodope and Thracia terranes, separated by the Nestos suture. The correlation of our findings in northern Greece to the Bulgarian part of the Massif suggests a northern rooting of the Nestos Suture. This configuration results of the closure of a marginal oceanic basin of the Tethys system by a north-directed subduction. This interpretation is supported by the geochemical affinities of the orthogneisses: the Late-Jurassic igneous rocks formed by subduction-related magmatism, pprobably the same north-directed subduction that gave rise to the UHP metamorphism of the metasediments of the “melange” zone. It is noteworthy that the UHP-HP relicts seem to be restricted to the contact between the two terranes suggesting that the UHP relicts are exhumed only within the suture zone. Furthermore, the singularity of the suture suggests that the Late-Jurassic subduction explains the occurrence of UHP and eclogite relicts in the Central Rhodope despite the large age range previously attributed the UHP and/or HP stage.

Hox genes and the regulation of programmed cell death in the embryonic central nervous system of Drosophila melanogaster

This study deals with the function and regulation of programmed cell death, or apoptosis, in the development of the embryonic central nervous system of Drosophila melanogaster. The first part provides a description of apoptosis-deficient embryos, which showed that preventing apoptosis does not cause gross morphological defects in the CNS, as it appears well organized despite the presence of too many cells. An analysis of the incidence and pattern of apoptosis over the course of development discloses a partly very orderly pattern suggesting tight spatio-temporal control, but also reveals random apoptotic cells, which suggests a certain amount of plasticity in the embryo. This analysis also allowed precise identification of some of the dying neural cells in the embryo, and establishment of single cell models for studying regulation of segment-specific apoptosis in the embryonic CNS. In the second part of the work, further investigations into mechanisms controlling segment-specific apoptosis revealed the involvement of two Hox genes, Antennapedia (Antp) and Ultrabithorax (Ubx), in this process. Hox genes control the formation of segment-specific structures in their domains of expression, but also regulate organ and tissue morphogenesis. The study presented here shows that Antp and Ubx play antagonistic roles in motoneuron survival in the embryo. Ubx expression in the CNS is strongly upregulated at a late point in development, when most cells have begun to differentiate. This upregulation shortly precedes Ubx-dependent, segment-specific apoptosis of two differentiated motoneurons. It could further be demonstrated that Antp is required for proper development of the NB7-3 lineage and for survival of the NB7-3 motoneuron in the anterior thoracic segments. In segments where Antp and Ubx expression overlaps, Ubx counteracts the anti-apoptotic function of Antp, resulting in cell death. Thus, these two Hox genes play opposing roles in the survival of differentiated neurons in the late developing nervous system. They thereby contribute to establishment of correct connections between outward-projecting neurons and their targets, which is crucial for the assembly of functional neural circuits, as these have to fulfill region-specific locomotion and sensory requirements along the antero-posterior body axis.

Delayed osteoblast differentiation and altered inflammatory response around implants placed in incisor sockets of type 2 diabetic rats

Objective: Central to the process of osseointegration is the recruitment of mesenchymal progenitor cells to the healing site, their proliferation and differentiation to bone synthesising osteoblasts. The process is under the control of pro-inflammatory cytokines and growth factors. The aim of this study was to monitor these key stages of osseointegration and the signalling milieu during bone healing around implants placed in healthy and diabetic bone. Methods: Implants were placed into the sockets of incisors extracted from the mandibles of normal Wistar and diabetic Goto-Kakizaki rats. Mandibles 1-12 weeks post-insertion of the implant were examined by histochemistry and immunocytochemistry to localise the presence of Stro-1- positive mesenchymal progenitor cells, proliferating cellular nuclear antigen proliferative cells, osteopontin and osteocalcin, macrophages, pro-inflammatory cytokines interleukin (IL)-1 , IL-6, tumour necrosis factor (TNF)- and tumour growth factor (TGF)- 1. Image analysis provided a semi-quantification of positively expressing cells. Results: Histological staining identified a delay in the formation of mineralised bone around implants placed in diabetic animals. Within the diabetic bone, the migration of Stro-1 mesenchymal cells in the healing tissue appeared to be unaffected. However, in the diabetic healing bone, the onset of cell proliferation and osteoblast differentiation were delayed and subsequently prolonged compared with normal bone. Similar patterns of change were observed in diabetic bone for the presence of IL-1 , TNF- , macrophages and TGF- 1. Conclusion: The observed alterations in the extracellular presence of pro-inflammatory cytokines, macrophages and growth factors within diabetic tissues that correlate to changes in the signalling milieu, may affect the proliferation and differentiation of mesenchymal progenitor cells in the osseointegration process. To cite this article: Colombo JS, Balani D, Sloan AJ, St Crean J, Okazaki J, Waddington RJ. Delayed osteoblast differentiation and altered inflammatory response around implants placed in incisor sockets of type 2 diabetic rats Clin. Oral Impl. Res22, 2011; 578-586 doi: 10.1111/j.1600-0501.2010.01992.x.

Assessing the efficiency of a pharmacokinetic-based algorithm for target-controlled infusion of ketamine in ponies

The objective of this study was to assess a pharmacokinetic algorithm to predict ketamine plasma concentration and drive a target-controlled infusion (TCI) in ponies. Firstly, the algorithm was used to simulate the course of ketamine enantiomers plasma concentrations after the administration of an intravenous bolus in six ponies based on individual pharmacokinetic parameters obtained from a previous experiment. Using the same pharmacokinetic parameters, a TCI of S-ketamine was then performed over 120 min to maintain a concentration of 1 microg/mL in plasma. The actual plasma concentrations of S-ketamine were measured from arterial samples using capillary electrophoresis. The performance of the simulation for the administration of a single bolus was very good. During the TCI, the S-ketamine plasma concentrations were maintained within the limit of acceptance (wobble and divergence <20%) at a median of 79% (IQR, 71-90) of the peak concentration reached after the initial bolus. However, in three ponies the steady concentrations were significantly higher than targeted. It is hypothesized that an inaccurate estimation of the volume of the central compartment is partly responsible for that difference. The algorithm allowed good predictions for the single bolus administration and an appropriate maintenance of constant plasma concentrations.

Properties of low-threshold motor axons in the human median nerve

This study investigated the excitability and accommodative properties of low-threshold human motor axons to test whether these motor axons have greater expression of the persistent Na(+) conductance, I(NaP). Computer-controlled threshold tracking was used to study 22 single motor units and the data were compared with compound motor potentials of various amplitudes recorded in the same experimental session. Detailed comparisons were made between the single units and compound potentials that were 40% or 5% of maximal amplitude, the former because this is the compound potential size used in most threshold tracking studies of axonal excitability, the latter because this is the compound potential most likely to be composed entirely of motor axons with low thresholds to electrical recruitment. Measurements were made of the strength-duration relationship, threshold electrotonus, current-voltage relationship, recovery cycle and latent addition. The findings did not support a difference in I(NaP). Instead they pointed to greater activity of the hyperpolarization-activated inwardly rectifying current (I(h)) as the basis for low threshold to electrical recruitment in human motor axons. Computer modelling confirmed this finding, with a doubling of the hyperpolarization-activated conductance proving the best single parameter adjustment to fit the experimental data. We suggest that the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel(s) expressed on human motor axons may be active at rest and contribute to resting membrane potential.

In vivo measurement of central corneal thickness in normal chicks (Gallus gallus domesticus) with the optical low-coherence reflectometer

OBJECTIVE To determine the practicability and accuracy of central corneal thickness (CCT) measurements in living chicks utilizing a noncontact, high-speed optical low-coherence reflectometer (OLCR) mounted on a slit lamp. ANIMALS STUDIED Twelve male chicks (Gallus gallus domesticus). Procedures  Measurements of CCT were obtained in triplicate in 24 eyes of twelve 1-day-old anaesthetized chicks using OLCR. Every single measurement taken by OLCR consisted of the average result of 20 scans obtained within seconds. Additionally, corneal thickness was determined histologically after immersion fixation in Karnovsky's solution alone (20 eyes) or with a previous injection of the fixative into the anterior chamber before enucleation (4 eyes). RESULTS Central corneal thickness measurements using OLCR in 1-day-old living chicks provide a rapid and feasible examination technique. Mean CCT measured with OLCR (189.7 ± 3.34 μm) was significantly lower than histological measurements (242.1 ± 47.27 μm) in eyes with fixation in Karnovsky's solution (P = 0.0005). In eyes with additional injection of Karnovsky's fixative into the anterior chamber, mean histologically determined CCT was 195.2 ± 8.25 μm vs. 191.9 ± 8.90 μm with OLCR. A trend for a lower variance was found compared to the eyes that had only been immersion fixed. CONCLUSION Optical low-coherence reflectometry is an accurate examination technique to measure in vivo CCT in the eye of newborn chicks. The knowledge of the thickness of the chick cornea and the ability to obtain noninvasive, noncontact measurements of CCT in the living animal may be of interest for research and development of eye diseases in chick models.

Thickness of the anterior maxillary facial bone wall-a retrospective radiographic study using cone beam computed tomography

The purpose of this retrospective radiographic study was to analyze the thickness of the facial bone wall at teeth in the anterior maxilla based on cone beam computed tomography (CBCT) images, since this anatomical structure is important for the selection of an appropriate treatment approach in patients undergoing postextraction implant placement. A total of 125 CBCT scans met the inclusion criteria, resulting in a sample size of 498 teeth. The thickness of the facial bone wall in the respective sagittal scans was measured perpendicular to the long axis of the tooth at two locations: at the crest level (4 mm apical to the cementoenamel junction; MP1) and at the middle of the root (MP2). No existing bone wall was found in 25.7% of all teeth at MP1 and in 10.0% at MP2. The majority of the examined teeth exhibited a thin facial bone wall (< 1 mm; 62.9% at MP1, 80.1% at MP2). A thick bone wall (? 1 mm) was found in only 11.4% of all examined teeth at MP1 and 9.8% at MP2. There was a statistically significant decrease in facial bone wall thickness from the first premolars to the central incisors. The facial bone wall in the crestal area of teeth in the anterior maxilla was either missing or thin in roughly 90.0% of patients. Both a missing and thin facial wall require simultaneous contour augmentation at implant placement because of the well-documented bone resorption that occurs at a thin facial bone wall following tooth extraction. Consequently, radiographic analysis of the facial bone wall using CBCT prior to extraction is recommended for selection of the appropriate treatment approach.

Last stop expulsion - The minority question and forced migration in East-Central Europe: 1918-49

This article deals with the European minorities in the period between the two world wars and with their final expulsion from nation-states at the end of World War II. First, the tensions which arose between the organised minorities and the successor states of the Habsburg Monarchy are accounted for primarily by the argument that the various minorities located within the successor states had already undergone a comprehensive processes of nationalisation within the Habsburg Empire. Therefore they were able to resist assimilation by the political elites of the new titular nations (Czechs, Poles, Rumanians, Serbs). A second topic is that of the use made of the minorities issue by Adolf Hitler to help achieve his expansionist aims. The minorities issue was central to the international destabilisation of interwar Europe. Finally, the mass expulsion of minorities (above all, Germans) after the end of the war is explained by strategic considerations on the part of the Allied powers as well as involving the nation-state regimes. It is argued, against a commonly held view, that German atrocities during the period of occupation had little to do with the decision to expel most ethnic Germans from their territories of settlement in Poland, Czechoslovakia and Yugoslavia. The article shows that it is necessary to treat national minorities in the first half of the twentieth century as a single phenomenon which shares similar features across the various nation-states of East-Central Europe.

Effect of intravenous tropisetron on modulation of pain and central hypersensitivity in chronic low back pain patients

The activation of 5-hydroxytryptamine-3 (5-HT-3) receptors in spinal cord can enhance intrinsic spinal mechanisms of central hypersensitivity, possibly leading to exaggerated pain responses. Clinical studies suggest that 5-HT-3 receptor antagonists may have an analgesic effect. This randomized, double-blind, placebo-controlled crossover study tested the hypothesis that the 5-HT-3 receptor antagonist tropisetron attenuates pain and central hypersensitivity in patients with chronic low back pain. Thirty patients with chronic low back pain, 15 of whom were women (aged 53 ± 14 years) and 15 men (aged 48 ± 14 years), were studied. A single intravenous injection of 0.9% saline solution, tropisetron 2mg, and tropisetron 5mg was administrated in 3 different sessions, in a double-blind crossover manner. The main outcome was the visual analogue scale (VAS) score of spontaneous low back pain before, and 15, 30, 60, and 90 minutes after drug administration. Secondary outcomes were nociceptive withdrawal reflexes to single and repeated electrical stimulation, area of reflex receptive fields, pressure pain detection and tolerance thresholds, conditioned pain modulation, and area of clinical pain. The data were analyzed by analysis of variance and panel multiple regressions. All 3 treatments reduced VAS scores. However, there was no statistically significant difference between tropisetron and placebo in VAS scores. Compared to placebo, tropisetron produced a statistically significant increase in pain threshold after single electrical stimulation, but no difference in all other secondary outcomes was found. A single-dose intravenous administration of tropisetron in patients with chronic low back pain had no significant specific effect on intensity of pain and most parameters of central hypersensitivity.

Single-cell gene-expression profiling reveals qualitatively distinct CD8 T cells elicited by different gene-based vaccines

CD8 T cells play a key role in mediating protective immunity against selected pathogens after vaccination. Understanding the mechanism of this protection is dependent upon definition of the heterogeneity and complexity of cellular immune responses generated by different vaccines. Here, we identify previously unrecognized subsets of CD8 T cells based upon analysis of gene-expression patterns within single cells and show that they are differentially induced by different vaccines. Three prime-boost vector combinations encoding HIV Env stimulated antigen-specific CD8 T-cell populations of similar magnitude, phenotype, and functionality. Remarkably, however, analysis of single-cell gene-expression profiles enabled discrimination of a majority of central memory (CM) and effector memory (EM) CD8 T cells elicited by the three vaccines. Subsets of T cells could be defined based on their expression of Eomes, Cxcr3, and Ccr7, or Klrk1, Klrg1, and Ccr5 in CM and EM cells, respectively. Of CM cells elicited by DNA prime-recombinant adenoviral (rAd) boost vectors, 67% were Eomes(-) Ccr7(+) Cxcr3(-), in contrast to only 7% and 2% stimulated by rAd5-rAd5 or rAd-LCMV, respectively. Of EM cells elicited by DNA-rAd, 74% were Klrk1(-) Klrg1(-)Ccr5(-) compared with only 26% and 20% for rAd5-rAd5 or rAd5-LCMV. Definition by single-cell gene profiling of specific CM and EM CD8 T-cell subsets that are differentially induced by different gene-based vaccines will facilitate the design and evaluation of vaccines, as well as enable our understanding of mechanisms of protective immunity.