The stereochemistry of the amino acid side chain influences the inflammatory potential of muramyl dipeptide in experimental meningitis

Intrathecal injections of 50 to 100 micro g of (N-acetylmuramyl-L-alanyl-D-isoglutamine) muramyl dipeptide (MDP)/rabbit dose-dependently triggered tumor necrosis factor alpha (TNF-alpha) secretion (12 to 40,000 pg/ml) preceding the influx of leukocytes in the subarachnoid space of rabbits. Intrathecal instillation of heat-killed unencapsulated R6 pneumococci produced a comparable leukocyte influx but only a minimal level of preceding TNF-alpha secretion. The stereochemistry of the first amino acid (L-alanine) of the MDP played a crucial role with regard to its inflammatory potential. Isomers harboring D-alanine in first position did not induce TNF-alpha secretion and influx of leukocytes. This stereospecificity of MDPs was also confirmed by measuring TNF-alpha release from human peripheral mononuclear blood cells stimulated in vitro. These data show that the inflammatory potential of MDPs depends on the stereochemistry of the first amino acid of the peptide side chain and suggest that intact pneumococci and MDPs induce inflammation by different pathways.

Future trials of endovascular mechanical recanalisation therapy in acute ischemic stroke patients: a position paper endorsed by ESMINT and ESNR : Part I: Current situation and major research questions

A new era of stroke treatment may have begun with mechanical thrombectomy (MT) by fully deployed closed-cell self-expanding stents (stent-triever). Multiple case series and the first randomised controlled trials (RCTs) have now been published. More studies are under way involving large numbers of patients, which in turn has resulted in less strict "pragmatic" study protocols. Problems with current trials include a lack of standardisation in the conduct of the recanalisation procedure, the definition of primary endpoints such as the grade of arterial recanalisation and tissue reperfusion, and the post-surgical care provided. In Part 1 of this two part series, we outline the current situation and the major research questions.

Taxonomic position and geographical distribution of the common sheep G1 and camel G6 strains of Echinococcus granulosus in three African countries

The taxonomic and phylogenetic status of Echinococcus granulosus strains are still controversial and under discussion. In the present study, we investigated the genetic polymorphism of E. granulosus isolates originating from three countries of Africa, including a region of Algeria, where the common G1 sheep and the camel G6 strains coexist sympatrically. Seventy-one hydatid cysts were collected from sheep, cattle, camels, and humans. Two mitochondrial markers (cox1 and nad1) were used for strain identification. Two nuclear markers (actII and hbx2) were used to study the possible occurrence of cross-fertilization. Despite the heterogeneity observed among the G1 isolates, they were all localized within one robust cluster. A second strong cluster was also observed containing all of the G6 isolates. Both strains appeared as two distinct groups, and no cases of interbreeding were found. Thus, the attribution of a species rank can be suggested. We also found the Tasmanian sheep G2 strain for the first time in Africa. Because of the slight variations observed between the common sheep and the Tasmanian sheep strains, further studies should be carried out to elucidate the epidemiological relevance of this genetic discrimination.

Change of the condyle-position in maximum intercuspidation during digital, clinical occlusal analysis

Digital analysis of the occlusal contacts can be performed with the T-scan device (T Scan III, TekScan, Boston, USA). However, the thickness of the interocclusal T-scan sheet (100 μm) may lead to a displacement of the mandible. Thus, the aim of this study was to investigate the impact of the T-scan sheet on the position of the mandibular condyles in maximum intercuspidation. Twenty dentate subjects with healthy jaw function were enrolled in the study. An ultrasonic axiography device was used to measure the position of the condyles. Ten 3D condyle positions in maximum intercuspidation of the teeth were recorded: first the reference position without the sheet, then 3 times without the sheet, 3 times with the sheet, and finally again 3 times without the sheet. There was a statistically significant difference (Wilcoxon matched pairs test) between the condyle positions with and without the interocclusally positioned T-scan sheet (P < 0.0005). The T-scan device lead to a displacement of the condyles of about 1 mm mainly in ventral direction (P = 0.005). Thus, occlusal analysis is not performed in physiological, maximum intercuspidation. This has to be considered when interpreting the measured contact points.

First thoughts on surface tonal patterns in Amawaka, a Panoan language of Peru and Brazil

Amawaka ([ɑmɨ̃ˈwɐkɑ]) is a highly endangered and underdocumented tonal language of the Headwaters (Fleck 2011) subgroup of the Panoan family in the Southwest Amazon Basin, spoken by approximately 200 people. Undocumented phonetic and phonological phenomena of Amawaka include its tonal structure, both in terms of surface realizations and the patterns underlying these realizations. Original audiovisual data from the author’s fieldwork in various Amawaka communities at the Peru-Brazil border will illuminate the as-yet obscure tonal systematicity of the language. Unlike other elements, monosyllabic bimoraic phonological nominal words with long vowels display variation in their surface realization. All the words with the open back unrounded /ɑ/, like /ˈkɑ̀:/ (patarashca, a traditional Amazonian dish), /ˈnɑ̀:/ “mestizo” etc. [with the exception of /ˈtɑ:/ “reed”, which surfaces with either a H or L tone] bear a low tone in isolation. This realization contrasts with all the encountered nominal monosyllables with vowels from the close and close-mid front and central spectrum /i, ɘ, ɨ, ɨ̃/, which clearly surface as high tone words in isolation, for example /ˈmɨ̃́:/ (a clay-lick for animals), /ˈwí:/ “Anopheles, spp. mosquito”. Monosyllables with close-mid back rounded /o/ have a less restrictive pitch that varies among speakers from low to high realizations, and sometimes even across the speech tokens from an individual speaker, e.g. /wó:/ or /wō:/ “hair”, /ɧō:/ or /ɧò:/ (a type of tarantula). Phrasal tonal phonology is more complex, when these three kinds of monosyllables appear in larger noun phrases. Some retain the same surface tones as their isolation form, while others seem to vary freely in their surface realization, e.g. /ˈtɘ́:.nɑ̀:/ or /ˈtɘ́:.nɑ́:/ ‘one mestizo’. Yet other monosyllables, e.g. /mɑ̀:/, exhibit a falling tone when preceded by a H syllable, suggesting probably latent tone sandhi phenomena, e.g /ˈtɘ́:.mɑ̂:/ (one clay-lick for parrots). In disyllabic, trisyllabic and quadrisyllabic nouns, tonal and stress patterns generally seem to be more consistent and tend to be retained both in isolation and in larger intonational phrases. Disyllabic nouns, for instance, surface as L-H or L-L when a glottal stop is in coda position. The association of L with a glottal stop is a feature that occurs in other Panoan languages as well, like Capanahua (Loos 1969), and more generally it is an areal feature, found in other parts of Amazonia (Hyman 2010). So, tone has significant interactions with the glottal stop and glottalization, which generally co-occurs with L. The data above suggest that the underlying tonal system of Amawaka is much more complex than the privative one-tone analysis (/H/ vs. Ø, i.e. lack of tone) that was proposed by Russell and Russell (1959). Evidence from field data suggests either an equipollent (Hyman 2010) two-tone opposition between /H/ and /L/, or a hybrid system, with both equipollent and privative features; that is, /H/ vs. /L/ vs. either Ø or /M/. This first systematic description of Amawaka tone, in conjunction with ongoing research, is poised to address broader questions concerning interrelationships between surface/underlying tone and other suprasegmental features, such as nasality, metrical stress, and intonation. References Fleck, David W. 2011. Panoan languages and linguistics. In Javier Ruedas and David W. Fleck (Eds.), Panoan Histories and Interethnic Identities, To appear. Hyman, Larry. 2010. Amazonia and the typology of tone systems. Presented at the conference Amazonicas III: The structure of the Amazonian languages. Bogotá. Loos, Eugene E. 1969. The phonology of Capanahua and its grammatical basis. Norman: SIL and U. Oklahoma. Russell, Robert & Dolores. 1959. Syntactotonemics in Amahuaca (Pano). Série Lingüistica Especial, 128-167. Publicaçoes do Museu Nacional, Rio de Janeiro, Brasil.

Cup Implant Planning Based on 2-D/3-D Radiographic Pelvis Reconstruction-First Clinical Results.

GOAL: In the following, we will present a newly developed X-ray calibration phantom and its integration for 2-D/3-D pelvis reconstruction and subsequent automatic cup planning. Two different planning strategies were applied and evaluated with clinical data. METHODS: Two different cup planning methods were investigated: The first planning strategy is based on a combined pelvis and cup statistical atlas. Thereby, the pelvis part of the combined atlas is matched to the reconstructed pelvis model, resulting in an optimized cup planning. The second planning strategy analyzes the morphology of the reconstructed pelvis model to determine the best fitting cup implant. RESULTS: The first planning strategy was compared to 3-D CT-based planning. Digitally reconstructed radiographs of THA patients with differently severe pathologies were used to evaluate the accuracy of predicting the cup size and position. Within a discrepancy of one cup size, the size was correctly identified in 100% of the cases for Crowe type I datasets and in 77.8% of the cases for Crowe type II, III, and IV datasets. The second planning strategy was analyzed with respect to the eventually implanted cup size. In seven patients, the estimated cup diameter was correct within one cup size, while the estimation for the remaining five patients differed by two cup sizes. CONCLUSION: While both planning strategies showed the same prediction rate with a discrepancy of one cup size (87.5%), the prediction of the exact cup size was increased for the statistical atlas-based strategy (56%) in contrast to the anatomically driven approach (37.5%). SIGNIFICANCE: The proposed approach demonstrated the clinical validity of using 2-D/3-D reconstruction technique for cup planning.

First isolation of a rhabdovirus from perch Perca fluviatilis in Switzerland

Perca fluviatilis is a fish species of increasing interest to the Swiss fish farming industry. In recent years, recirculation systems have been specifically set up to increase production. In one of these farms, abnormal spiral swimming associated with elevated mortalities occurred in repeated batches of imported perch shortly after stocking on several occasions. No bacterial or parasitic etiology was detected, but a virus grown in bluegill fry (BF-2) cells was identified as perch rhabdovirus. Subsequent investigations of other samples suggested a viral tropism for the central nervous system (CNS). Phylogenetic analysis of the partial N and entire G gene sequences positioned this isolate in genogroup C of the species Perch rhabdovirus, with high nucleotide and amino acid (aa) sequence identities with the DK5533 strain isolated in Denmark in 1989. Comparative studies using other closely related isolates allowed the distinction of 2 serological Patterns among perch rhabdoviruses and the identification of a proline substitution by a serine in Position 147 of the glycoprotein potentially involved in antigenic differentiation. Even if perch imported onto the farm tested negative by virus isolation prior to transport, they may have been the origin of this outbreak since CNS tissue was not included in the samples that were analyzed. Another possibility might be a sub-clinical infection with a viral load in resident fish too low to be detected. This study reports the first isolation of a perch rhabdovirus in Switzerland, and emphasizes the necessity of optimizing diagnostic tools that facilitate better control of the risks associated with fish translocation.

Sudden cardiac arrest in sports - need for uniform registration: A Position Paper from the Sport Cardiology Section of the European Association for Cardiovascular Prevention and Rehabilitation

There are large variations in the incidence, registration methods and reported causes of sudden cardiac arrest/sudden cardiac death (SCA/SCD) in competitive and recreational athletes. A crucial question is to which degree these variations are genuine or partly due to methodological incongruities. This paper discusses the uncertainties about available data and provides comprehensive suggestions for standard definitions and a guide for uniform registration parameters of SCA/SCD. The parameters include a definition of what constitutes an 'athlete', incidence calculations, enrolment of cases, the importance of gender, ethnicity and age of the athlete, as well as the type and level of sporting activity. A precise instruction for autopsy practice in the case of a SCD of athletes is given, including the role of molecular samples and evaluation of possible doping. Rational decisions about cardiac preparticipation screening and cardiac safety at sport facilities requires increased data quality concerning incidence, aetiology and management of SCA/SCD in sports. Uniform standard registration of SCA/SCD in athletes and leisure sportsmen would be a first step towards this goal.

Time-order errors and standard-position effects in duration discrimination: An experimental study and an analysis by the sensation-weighting model

Studies have shown that the discriminability of successive time intervals depends on the presentation order of the standard (St) and the comparison (Co) stimuli. Also, this order affects the point of subjective equality. The first effect is here called the standard-position effect (SPE); the latter is known as the time-order error. In the present study, we investigated how these two effects vary across interval types and standard durations, using Hellström’s sensation-weighting model to describe the results and relate them to stimulus comparison mechanisms. In Experiment 1, four modes of interval presentation were used, factorially combining interval type (filled, empty) and sensory modality (auditory, visual). For each mode, two presentation orders (St–Co, Co–St) and two standard durations (100 ms, 1,000 ms) were used; half of the participants received correctness feedback, and half of them did not. The interstimulus interval was 900 ms. The SPEs were negative (i.e., a smaller difference limen for St–Co than for Co–St), except for the filled-auditory and empty-visual 100-ms standards, for which a positive effect was obtained. In Experiment 2, duration discrimination was investigated for filled auditory intervals with four standards between 100 and 1,000 ms, an interstimulus interval of 900 ms, and no feedback. Standard duration interacted with presentation order, here yielding SPEs that were negative for standards of 100 and 1,000 ms, but positive for 215 and 464 ms. Our findings indicate that the SPE can be positive as well as negative, depending on the interval type and standard duration, reflecting the relative weighting of the stimulus information, as is described by the sensation-weighting model.

The position effect in a Rasch-homogenous test: A fixed-links modeling approach.

The position effect describes the influence of just-completed items in a psychological scale on subsequent items. This effect has been repeatedly reported for psychometric reasoning scales and is assumed to reflect implicit learning during testing. One way to identify the position effect is fixed-links modeling. With this approach, two latent variables are derived from the test items. Factor loadings of one latent variable are fixed to 1 for all items to represent ability-related variance. Factor loadings on the second latent variable increase from the first to the last item describing the position effect. Previous studies using fixed-links modeling on the position effect investigated reasoning scales constructed in accordance with classical test theory (e.g., Raven’s Progressive Matrices) but, to the best of our knowledge, no Rasch-scaled tests. These tests, however, meet stronger requirements on item homogeneity. In the present study, therefore, we will analyze data from 239 participants who have completed the Rasch-scaled Viennese Matrices Test (VMT). Applying a fixed-links modeling approach, we will test whether a position effect can be depicted as a latent variable and separated from a latent variable representing basic reasoning ability. The results have implications for the assumption of homogeneity in Rasch-homogeneous tests.