Alpha synuclein dimers and oligomers are increased in overexpressing conditions in vitro and in vivo

Parkinson's disease is characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta along with the formation of intracellular fibrillar inclusions (Lewy bodies and Lewy neuritis), which are mainly composed of aggregated α-synuclein (ASYN). This latter is a 14 kDa protein that localizes to synaptic vesicles in nerve terminals and promotes soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex assembly. We explored the monomeric and oligomeric state of ASYN in vitro in HEK293s and SH-SY5Y cell lines. In addition rats were injected in the substantia nigra with an Adeno associated virus carrying the human A53T mutation of ASYN (in vivo experiments). We show that human wild type ASYN as well as PD-linked mutations (A30P, E46K and A53T) in overexpressing conditions mostly exists in a monomeric state in equilibrium with dimeric forms. The monomer/dimer ratio is unaffected by PD-linked mutation. Furthermore, the A30P, E46K and A53T mutations overexpression strongly increased cell death compared to wild type ASYN. Taken together, our data suggest that ASYN dimers amount do not directly correlate to reduced cellular viability, suggesting a different role in protein function and induced pathology. Our data suggest that early ASYN neuro-pathogenic effects are probably mediated by other molecular processes than increased oligomerization alone.

In Vitro and In Vivo Identification of Novel Positive Allosteric Modulators of the Human Dopamine D2 and D3 Receptor

Agonists at dopamine D2 and D3 receptors are important therapeutic agents in the treatment of Parkinson's disease. Compared with the use of agonists, allosteric potentiators offer potential advantages such as temporal, regional, and phasic potentiation of natural signaling, and that of receptor subtype selectivity. We report the identification of a stereoselective interaction of a benzothiazol racemic compound that acts as a positive allosteric modulator (PAM) of the rat and human dopamine D2 and D3 receptors. The R isomer did not directly stimulate the dopamine D2 receptor but potentiated the effects of dopamine. In contrast the S isomer attenuated the effects of the PAM and the effects of dopamine. In radioligand binding studies, these compounds do not compete for binding of orthosteric ligands, but indeed the R isomer increased the number of high-affinity sites for [(3)H]-dopamine without affecting K(d). We went on to identify a more potent PAM for use in native receptor systems. This compound potentiated the effects of D2/D3 signaling in vitro in electrophysiologic studies on dissociated striatal neurons and in vivo on the effects of L-dopa in the 6OHDA (6-hydroxydopamine) contralateral turning model. These PAMs lacked activity at a wide variety of receptors, lacked PAM activity at related Gi-coupled G protein-coupled receptors, and lacked activity at D1 receptors. However, the PAMs did potentiate [(3)H]-dopamine binding at both D2 and D3 receptors. Together, these studies show that we have identified PAMs of the D2 and D3 receptors both in vitro and in vivo. Such compounds may have utility in the treatment of hypodopaminergic function.

Bovine Staphylococcus aureus: Subtyping, evolution, and zoonotic transfer

Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies using ribosomal spacer (RS)-PCR, however, demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infections are genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. Furthermore, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. In addition to RS-PCR, other methods for subtyping Staph. aureus are known, including spa typing and multilocus sequence typing (MLST). They are based on sequencing the spa and various housekeeping genes, respectively. The aim of the present study was to compare the 3 analytic methods using 456 strains of Staph. aureus isolated from milk of bovine intramammary infections and bulk tanks obtained from 12 European countries. Furthermore, the phylogeny of animal Staph. aureus was inferred and the zoonotic transfer of Staph. aureus between cattle and humans was studied. The analyzed strains could be grouped into 6 genotypic clusters, with CLB, CLC, and CLR being the most prominent ones. Comparing the 3 subtyping methods, RS-PCR showed the highest resolution, followed by spa typing and MLST. We found associations among the methods but in many cases they were unsatisfactory except for CLB and CLC. Cluster CLB was positive for clonal complex (CC)8 in 99% of the cases and typically positive for t2953; it is the cattle-adapted form of CC8. Cluster CLC was always positive for tbl 2645 and typically positive for CC705. For CLR and the remaining subtypes, links among the 3 methods were generally poor. Bovine Staph. aureus is highly clonal and a few clones predominate. Animal Staph. aureus always evolve from human strains, such that every human strain may be the ancestor of a novel animal-adapted strain. The zoonotic transfer of IMI- and milk-associated strains of Staph. aureus between cattle and humans seems to be very limited and different hosts are not considered as a source for mutual, spontaneous infections. Spillover events, however, may happen.

Staphylococcus aureus genotype B and other genotypes isolated from cow milk in European countries

Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies, however, have demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infection is genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. In addition, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. The aim of this study was to subtype strains of Staph. aureus isolated from bovine mastitic milk and bulk tank milk to obtain a unified view of the presence of bovine staphylococcal subtypes in 12 European countries. A total of 456 strains of Staph. aureus were subjected to different typing methods: ribosomal spacer PCR, detection of enterotoxin genes, and detection of gene polymorphisms (lukE, coa). Major genotypes with their variants were combined into genotypic clusters (CL). This study revealed 5 major CL representing 76% of all strains and comprised CLB, CLC, CLF, CLI, and CLR. The clusters were characterized by the same genetic properties as the Swiss isolates, demonstrating high clonality of bovine Staph. aureus. Interestingly, CLB was situated in central Europe whereas the other CL were widely disseminated. The remaining 24% of the strains comprised 41 genotypes and variants, some of which (GTAM, GTBG) were restricted to certain countries; many others, however, were observed only once.

Behavioural Assessment of the A2a/NR2B Combination in the Unilateral 6-OHDA-Lesioned Rat Model: A New Method to Examine the Therapeutic Potential of Non-Dopaminergic Drugs

In Parkinson's disease (PD), dopaminergic therapies are often associated with the development of motor complications. Attention has therefore been focused on the use of non-dopaminergic drugs. This study developed a new behavioural method capable of demonstrating the added value of combining adenosinergic and glutamatergic receptor antagonists in unilateral 6-OHDA lesioned rats. Rats were dosed orally with Tozadenant, a selective A2A receptor antagonist, and three different doses of Radiprodil, an NR2B-selective NMDA receptor antagonist. The drugs were given alone or in combination and rats were placed in an open-field for behavioural monitoring. Video recordings were automatically analysed. Five different behaviours were scored: distance traveled, ipsi- and contraversive turns, body position, and space occupancy. The results show that A2A or NR2B receptor antagonists given alone or in combination did not produce enhanced turning as observed with an active dose of L-Dopa/benserazide. Instead the treated rats maintained a straight body position, were able to shift from one direction to the other and occupied a significantly larger space in the arena. The highest "Tozadenant/Radiprodil" dose combination significantly increased all five behavioural parameters recorded compared to rats treated with vehicle or the same doses of the drugs alone. Our data suggest that the A2A/NR2B antagonist combination may be able to stimulate motor activity to a similar level as that achieved by L-Dopa but in the absence of the side-effects that are associated with dopaminergic hyperstimulation. If these results translate into the clinic, this combination could represent an alternative symptomatic treatment option for PD.

Clinical characteristics of human immunodeficiency virus patients being referred for liver transplant evaluation: a descriptive cohort study

BACKGROUND

Liver transplantation (LT) is a treatment option for select human immunodeficiency virus (HIV)-infected patients with advanced liver disease. The aim of this study was to describe LT evaluation outcomes in HIV-infected patients.

METHODS

All HIV-infected patients referred for their first LT evaluation at the Mount Sinai Medical Center were included in this retrospective, descriptive cohort study. Multivariable logistic regression was used to identify factors independently associated with listing.

RESULTS

Between February 2000 and April 2012, 366 patients were evaluated for LT, with 66 (18.0%) listed for LT and 300 (82.0%) not listed. Fifty-one patients (13.9%) died before completing evaluation and 85 (23.2%) were too early for listing. Reasons patients were declined for listing were psychosocial (15.8%), HIV-related (10.4%), loss to follow-up (9.6%), surgical/medical (6.0%), liver-related (4.4%), patient choice (3.4%), and financial (1.6%). Listed patients were more likely to have hepatocellular carcinoma (HCC) (43.1% vs. 17.1%; P < 0.0001) and less likely to have hepatitis B (6.2% vs. 15.7%; P = 0.04) or a psychiatric history (19.7% vs. 35.2%; P = 0.02) than those not listed. In multivariable analysis, HCC (odds ratio [OR] 5.79; 95% confidence interval [95% CI]: 2.97-11.28), model for end-stage liver disease (MELD) score at referral (OR 1.06; 95% CI 1.01-1.11), and hepatitis B (OR 0.26; 95% CI 0.08-0.79) were associated with listing.

CONCLUSION

MELD score and HCC were positive predictors of listing in HIV-infected patients referred for LT evaluation and, therefore, timely referrals are vital in these patients. As MELD is a predictor for death while undergoing evaluation, rapid evaluation should be performed in HIV-infected patients with a higher MELD score.

Lack of additive role of ageing in nigrostriatal neurodegeneration triggered by α-synuclein overexpression

INTRODUCTION

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons as well as the presence of proteinaceous inclusions named Lewy bodies. α-synuclein (α-syn) is a major constituent of Lewy bodies, and the first disease-causing protein characterized in PD. Several α-syn-based animal models of PD have been developed to investigate the pathophysiology of PD, but none of them recapitulate the full picture of the disease. Ageing is the most compelling and major risk factor for developing PD but its impact on α-syn toxicity remains however unexplored. In this study, we developed and exploited a recombinant adeno-associated viral (AAV) vector of serotype 9 overexpressing mutated α-syn to elucidate the influence of ageing on the dynamics of PD-related neurodegeneration associated with α-syn pathology in different mammalian species.

RESULTS

Identical AAV pseudotype 2/9 vectors carrying the DNA for human mutant p.A53T α-syn were injected into the substantia nigra to induce neurodegeneration and synucleinopathy in mice, rats and monkeys. Rats were used first to validate the ability of this serotype to replicate α-syn pathology and second to investigate the relationship between the kinetics of α-syn-induced nigrostriatal degeneration and the progressive onset of motor dysfunctions, strikingly reminiscent of the impairments observed in PD patients. In mice, AAV2/9-hα-syn injection into the substantia nigra was associated with accumulation of α-syn and phosphorylated hα-syn, regardless of mouse strain. However, phenotypic mutants with either accelerated senescence or resistance to senescence did not display differential susceptibility to hα-syn overexpression. Of note, p-α-syn levels correlated with nigrostriatal degeneration in mice. In monkeys, hα-syn-induced degeneration of the nigrostriatal pathway was not affected by the age of the animals. Unlike mice, monkeys did not exhibit correlations between levels of phosphorylated α-syn and neurodegeneration.

CONCLUSIONS

In conclusion, AAV2/9-mediated hα-syn induces robust nigrostriatal neurodegeneration in mice, rats and monkeys, allowing translational comparisons among species. Ageing, however, neither exacerbated nigrostriatal neurodegeneration nor α-syn pathology per se. Our unprecedented multi-species investigation thus favours the multiple-hit hypothesis for PD wherein ageing would merely be an aggravating, additive, factor superimposed upon an independent disease process.

Haematological cancer and quality of life: a systematic literature review

The aim of this study is to examine the impact of haematological cancers on quality of life (QoL). A review of the international literature was conducted from the databases ‘PsycInfo' and 'Medline' using the keywords: 'haematological cancer', 'quality of life', 'physical', 'psychological', 'social', 'vocational', 'professional', 'economic', 'cognitive', and 'sexual'. Twenty-one reliable studies were analysed. Among these studies, 12 showed that haematological cancer altered overall QoL, 8 papers found a deterioration of physical dimension, 8 papers reported on functional and role dimensions, 11 papers reported on the psychological component and 9 on the social component. Moreover, one study and two manuscripts, respectively, reported deteriorated sexual and cognitive dimensions. Our review demonstrates that the different dimensions of QoL are deteriorated by haematological malignancies and, probably, by the side effects of treatment.

Clinical predictors of adverse outcome in severe sepsis patients with lactate 2-4 mM admitted to the hospital

BACKGROUND

Severe sepsis patients with initial lactate level 2-4 mM are commonly considered to have lower risk for mortality and adverse outcomes.

AIM

We aim to determine clinical variables that are associated with adverse outcome in these patients.

DESIGN

A retrospective cohort study.

METHODS

Severe sepsis patients with initial lactate ≥ 2 and < 4 mM admitted to our hospital were examined for any of the following primary outcomes: (i) in-hospital death, (ii) vasopressor requirement, (iii) use of mechanical ventilator, (iv) lactate ≥ 4.0 mM or (v) need care in the intensive care unit (ICU) within 48 h.

RESULTS

Five-hundred and thirty-five patients were enrolled, age 58.7 ± 19.3 years, 53.2% male. The most common sources of infection were urinary tract infection and pneumonia, 38.3 and 35.7%, respectively. One-hundred and twenty-four (23.2%) patients had at least one primary adverse outcome within 48 h, including in-hospital death 1.1%, vasopressor requirement 12.9%, use of mechanical ventilator 13.3%, increase lactate ≥ 4.0 mM in 5.6% patients and 21.5% of patients requiring ICU (including 13.8% of the patients admitted directly to ICU from the emergency department, and 7.7% initially admitted to the general medical ward but later required ICU transfer). Altered mentation, hypotension, tachypnea and elevated blood urea nitrogen at admission were associated with the primary outcome in multivariable logistic regression analysis, odds ratio 2.50 (95% confidence interval: 1.54, 4.06), 3.76 (2.31, 6.10), 1.97 (1.22, 3.17) and 1.78 (1.11, 2.83), respectively.

CONCLUSIONS

Our study suggests that clinicians should be cautious about the potential adverse outcomes in severe sepsis patients with initial lactate level between 2 and 4 mM and a presentation of altered mentation, hypotension, tachypnea and/or elevated blood urea nitrogen.

Unprecedented therapeutic potential with a combination of A2A/NR2B receptor antagonists as observed in the 6-OHDA lesioned rat model of Parkinson's disease

In Parkinson's disease, the long-term use of dopamine replacing agents is associated with the development of motor complications; therefore, there is a need for non-dopaminergic drugs. This study evaluated the potential therapeutic impact of six different NR2B and A2A receptor antagonists given either alone or in combination in unilateral 6-OHDA-lesioned rats without (monotherapy) or with (add-on therapy) the co-administration of L-Dopa: Sch-58261+ Merck 22; Sch-58261+Co-101244; Preladenant + Merck 22; Preladenant + Radiprodil; Tozadenant + Radiprodil; Istradefylline + Co-101244. Animals given monotherapy were assessed on distance traveled and rearing, whereas those given add-on therapy were assessed on contralateral rotations. Three-way mixed ANOVA were conducted to assess the main effect of each drug separately and to determine whether any interaction between two drugs was additive or synergistic. Additional post hoc analyses were conducted to compare the effect of the combination with the effect of the drugs alone. Motor activity improved significantly and was sustained for longer when the drugs were given in combination than when administered separately at the same dose. Similarly, when tested as add-on treatment to L-Dopa, the combinations resulted in higher levels of contralateral rotation in comparison to the single drugs. Of special interest, the activity observed with some combinations could not be described by a simplistic additive effect and involved more subtle synergistic pharmacological interactions. The combined administration of A2A/NR2B-receptor antagonists improved motor behaviour in 6-OHDA rats. Given the proven translatability of this model such a combination may be expected to be effective in improving motor symptoms in patients.

Preliminary assessment of bovine tuberculosis at the livestock/wildlife interface in two protected areas of northern Botswana

Protected areas of northern Botswana such as the Okavango Delta (OD) or Chobe National Park (CNP) are well-known hot spots for the conservation of African wildlife. However, their infection status regarding bovine tuberculosis (BTB) at the domestic/wildlife interface has never been investigated. To provide preliminary baseline data on the circulation of Mycobacterium bovis in those sites, we performed a cross-sectional survey on 130 buffalo in both protected areas (60 individuals from CNP and 70 from OD) and 818 cattle in their surrounding communal lands (369 in CNP and 449 in the OD). Whole-blood samples were tested using a commercial interferon-gamma assay (IFN-γ) with modifications. The apparent BTB prevalence in buffalo was nil in CNP and 0.7% 95% CI [0.2-1.9] in the OD, while the apparent BTB prevalence in cattle was 0.7% 95% CI [0.2-2.1] in the OD and 2.4% 95% CI [1.2-4.7] in CNP. True prevalence values calculated on the basis of the locally applicable IFN-γ test performance suggested that BTB prevalence was nil in both buffalo populations and in cattle from the OD interface, but reached 2.3% 95% CI [0.2-4.5] in cattle populations around CNP. The results of a questionnaire survey conducted among a sample of farmers living in the communities adjacent to each conservation area (97 and 38 persons in the OD and CNP, respectively) suggested a higher risk of the circulation of M. bovis at the wildlife/livestock interface of the CNP than at that of the OD. However, further comprehensive studies are needed to confirm the circulation of M. bovis and to monitor the inter-species and transboundary transmission of BTB in northern Botswana.

Prevalence and distribution of non-tuberculous mycobacteria (NTM) in cattle, African buffaloes (Syncerus caffer) and their environments in South Africa

It has been hypothesized that a variety of non-tuberculous mycobacteria (NTM) species to which livestock and wildlife species are naturally exposed induce broadly cross-reactive anti-mycobacterial immune responses which interfere with current standard diagnostic assays. Non-tuberculous mycobacteria have also been implicated in Mycobacterium bovis-specific immune responsiveness, hence potentially the development of tuberculosis. Cattle and African buffaloes are both maintenance hosts of bovine tuberculosis (BTB) in South Africa, yet the effective diagnosis and control in these species may be hampered by adverse effects of NTM. As part of an investigation of the role of NTM in the immune responsiveness of cattle and African buffaloes to NTM, we conducted a countrywide survey to establish the prevalent NTM species and their distribution in the natural environments of these animals. A total of 1123 samples (water, soil, nasal and pharyngeal swabs) were collected for mycobacterium isolation. In addition, NTM isolated from tissue samples between 1991 and 2011 were included in the analysis. Mycobacteria were isolated from 56% of the samples from the countrywide survey. A total of 420 NTM isolates from soil, water, animal tissues and animal-derived swab samples were genotyped with the following results: 302 belonged to 40 known NTM species, 79 were found to be closely related to 23 known NTM species, and 38 isolates were found to be potentially novel species that are not currently listed in the RIDOM and NCBI BLAST databases. The four NTM species or closely related groups most frequently isolated in this survey included Mycobacterium terrae (11.2% of isolates), a group of mycobacteria closely related to Mycobacterium moriokaense (referred to as M. moriokaense-like) (8.1% of isolates), Mycobacterium nonchromogenicum (7.4% of isolates) and Mycobacterium vaccae/M. vanbaalenii (5.2% of isolates). The phylogenetic analysis of the M. moriokaense-like isolates, based on the 16S rRNA sequences, revealed at least eight clusters, possibly associated with eight different NTM species. Our findings provide account of NTM species diversity and associated prevalences in cattle and African buffaloes and their environments in South Africa. The identification of the most prevalent NTM species in this study will allow for a targeted investigation of their effects on host immune responses.

Evaluation of the discriminatory power of variable number of tandem repeat typing of Mycobacterium bovis isolates from southern Africa

The usefulness of variable number tandem repeat (VNTR) typing based on limited numbers of loci has previously proven inferior compared to IS6110-RFLP typing when applied to the study of the molecular epidemiology of bovine tuberculosis (BTB) in both livestock and wildlife in southern Africa. In this study, the discriminatory power of 29 published VNTR loci in the characterization of 131 Mycobacterium bovis strains isolated predominantly from wildlife and a smaller number from livestock in southern Africa was assessed. Allelic diversities calculated when loci were evaluated on a selected panel of 23 M. bovis isolates with identified varying degrees of genetic relatedness from different geographic origins as well as M. bovis BCG ranged from 0.00 to 0.63. Of the 29 loci tested, 13 were polymorphic (QUB 11a, QUB 11b, QUB 18, ETR-B and -C, Mtub 21, MIRU 16 and 26, ETR-E, QUB 26, MIRU 23, ETR-A, and Mtub 12). In addition, a comparative evaluation of the 13 loci on a panel of 65 isolates previously characterized by IS6110 restriction fragment length polymorphism (RFLP) typing and further evaluation on 41 isolates with no typing history from Kruger National Park (KNP) highlighted that M. bovis from epidemiologically unrelated cases of BTB in different geographic regions can be adequately distinguished. However, there is a need for improvement of the method to fully discriminate between the parental KNP strain and its clones to allow the detection of evolutionary events causing transmission between and within wildlife species.

Über neue Emissionsbanden bei elektrischer Anregung des Ammoniaks

Bei elektrischer Anregung von Ammoniak unter Drucken bis zu 1 atm wurden im Bereich von 5200 bis 8500 A zwei neue, als „C“- und „D-Spektrum“ bezeichnete Bandensysteme beobachtet. Beide Spektren wurden sowohl im NH3 als auch im ND3 untersucht. Die Isotopieverschiebung ist groß. Für das C-Spektrum deuten die beobachteten Schwingungen auf einen Träger hin, der neben einem oder mehreren H-Atomen mindestens 2 N-Atome enthält.

Das C2Σ2→A2Σ+-Bandensystem von OH

Das in einer Entladung durch strömenden Wasserdampf zwischen 2248 und 2600 Å von SCHÜLER und MICHEL 1 (siehe auch BÉNOIST 3) beobachtete Spektrum wurde mit größerer Dispersion photographiert, neu analysiert und dem Übergang C2 Σ+ → A2 Σ+ von OH zugeordnet. Der C2 Σ+-Term führt zu den Dissoziationsprodukten O- (2Puu) und H+(1Sg). Da allein das nullte und erste Schwingungsniveau beobachtet werden, lassen sich die Gleichgewichtskonstanten teilweise nur abschätzen.

Für C2Σ+ von OH ergibt sich:

Te ≈ 90 105 cm—1,

ωe = 0,167 cm—1,

ωe ≈ 2 339 cm—1,

re = 2,166 Å,

ωe xe≈ 32 cm-1,

De 45 093 cm—1 (5,589 eV),

Be = 4,207 cm—1,

D0 = 43 931 cm—1 (5,445 eV).

Ein im SCHUMANN-Gebiet zwischen 1700 und 1900 A liegendes neues Emissionsspektrum wird kurz diskutiert.

Über den spektroskopischen Nachweis des Benzyl- und des Benzalradikals (C6H5CH2 und C6H5CH)

In der positiven Säule einer Glimmentladung zeigen Benzolderivate bei zusätzlicher Erwärmung des Entladungsrohres (bis ~300°C) neue Spektren, die auf einen schrittweisen Abbau des Substituenten hinweisen. Für Toluol, i-Propylbenzol und tertiäres Butylbenzol wird ein Abbauschema gegeben. Die bisher beobachteten Spektren werden an Hand dieses Schemas diskutiert. Dadurch ergeben sich neue Argumente für die Zuordnung des V- bzw. B-Spektrums zum Benzyl- bzw. Benzalradikal. Beim Spektrum des Benzylradikals wird gezeigt, daß es sich um den Übergang vom tiefsten angeregten Zustand zum Grundzustand handelt.

Bovine Tuberculosis and Brucellosis in Cattle and African Buffalo in the Limpopo National Park, Mozambique

Bovine tuberculosis (BTB) and brucellosis are prevalent in buffaloes of the Kruger National Park (KNP, South Africa). Both diseases were considered to have no or a very low prevalence in wildlife and livestock in and around the Limpopo National Park (LNP, Mozambique). The same applies for tuberculosis in Gonarezhou National Park (GNP, Zimbabwe), but just recently, BTB was detected in buffaloes in the GNP and fears arose that the disease might also spread to the LNP as a result of the partial removal of the fences between the three parks to form the Great Limpopo Transfrontier Park. To assess the status of both diseases in and around LNP, 62 buffaloes were tested for bovine tuberculosis (BTB) and bovine brucellosis. The percentage of positive BTB reactors in buffalo was 8.06% using BovidTB Stat-Pak® and 0% with BOVIGAM® IFN-γ test and IDEXX ELISA. The brucellosis seroprevalence in buffalo was found to be 17.72% and 27.42% using Rose Bengal Test (RBT) and ELISA, respectively. In addition, 2445 cattle in and around the LNP were examined for BTB using the single intradermal cervical comparative tuberculin test (SICCT), and an apparent prevalence of 0.98% was found with no significant difference inside (0.5%) and outside (1.3%) the park. This is the first published report on the presence of positive reactors to BTB and bovine brucellosis in buffalo and cattle in and outside the LNP. Monitoring the wildlife-livestock-human interface of zoonotic high-impact diseases such as BTB and brucellosis is of outmost importance for the successful implementation and management of any transfrontier park that aims to improve the livelihoods of the local communities.

GRIN2A mutations in acquired epileptic aphasia and related childhood focal epilepsies and encephalopathies with speech and language dysfunction

Epileptic encephalopathies are severe brain disorders with the epileptic component contributing to the worsening of cognitive and behavioral manifestations. Acquired epileptic aphasia (Landau-Kleffner syndrome, LKS) and continuous spike and waves during slow-wave sleep syndrome (CSWSS) represent rare and closely related childhood focal epileptic encephalopathies of unknown etiology. They show electroclinical overlap with rolandic epilepsy (the most frequent childhood focal epilepsy) and can be viewed as different clinical expressions of a single pathological entity situated at the crossroads of epileptic, speech, language, cognitive and behavioral disorders. Here we demonstrate that about 20% of cases of LKS, CSWSS and electroclinically atypical rolandic epilepsy often associated with speech impairment can have a genetic origin sustained by de novo or inherited mutations in the GRIN2A gene (encoding the N-methyl-D-aspartate (NMDA) glutamate receptor α2 subunit, GluN2A). The identification of GRIN2A as a major gene for these epileptic encephalopathies provides crucial insights into the underlying pathophysiology.

Bulk and Dispersed Phase Polymerization of Urethane in Twin Screw Extruders

The bulk and dispersed phase polymerizations of urethane were investigated in a co-rotating twin screw extruder. The residence time has predominant influence on the bulk polymerization in twin screw extruders. Furthermore, the polyurethane polydispersity decreases going down the screws, as the result of the extent of the reaction and mixing in the extruder. As expected, the polyurethane polydispersity at the die exit of the extruder is close to the theoretical value (Ip = 2). In the case of urethane polymerization in molten polyethylene matrix, the residence time distributions showed that the two monomers (isocyanate and alcohols) have different behaviors in the extruder in presence of PE due to the solubility of isocyanate and non-solubility of alcohols in PE. Furthermore, this solubility phenomenon PE induces an imbalance stoichiometry which limits the degree of polymerization (molecular weight) and a broadening of the molecular weight distribution during the blending process in extruder. Slip phenomenon was also observed at the die because of the presence of polyurethane, with low molecular weights, at the sample surfaces. An in-situ pre-polymerizing step of isocyanate/alcohols tends to eliminate this phenomenon. Then, the aim of the present work was to study the formation of a polyethylene/polyurethane blend polymer via in situ polymerization of diols and diisocyanate monomers dispersed in a twin screw extruder.

Polymerization of ∊-Caprolactone in a Twin Screw Extruder

The purpose of this work is to model the bulk polymerization of ∊-caprolactone in a corotating twin screw extruder. Starting from kinetic data and rheological laws previously defined, we use a twin screw flow modelling software to calculate the progress of the polymerization along the extruder. Experiments are performed to assess the influence of processing conditions (feed rate, screw speed, barrel temperature, initiator concentration) and to validate the model. They put in evidence the control of the polymerization process by the temperature and the residence time in the extruder. It is shown that a good correlation between theoretical and experimental results can only be obtained if accurate kinetic and rheological data are used in the model.

Bulk Polymerization of ∊-Caprolactone in Twin Screw Extruder

The ∊-caprolactone bulk polymerisation, initiated by tetra-propoxy titanium, was investigated in a co-rotating twin screw extruder. On the basis of pressure measurements, the process dynamic modelling was achieved. The pressure drop at the exit die of the extruder was correlated to the rheological behaviour of the melt polycaprolactone owing to equations which characterise the flow inside the die. The residence time distribution modelling was determined with an in-line Ultra-Violet fluorescence method. Thus, the combination of both modellings leads to the process dynamic modelling. This work constitutes the basis for an approach of the process regulation by the way of an internal model control. Simulation has given good results. However, the large response time to the control, relative to the process dynamic, constitutes effectiveness limiting factor for experimental control of the process.

Melt Temperatures and Residence Times in an Extruder by Infrared Spectroscopy

This article presents melt temperature measurements with an infrared thermometer during extrusion and investigates the influence by the surface emissivity and the rotating screw. This influence can be used for on line residence time measurements in the extruder line, to measure the number of revolutions of the screw, and to measure both the surface temperature and the bulk's temperature.

The results show that colouring the PE with a high emisffisivity tracer allows us to measure the melt's surface temperature and minimise the influence of the rotating screw. Its influence is weaker in complete filled section as in partial filled sections of the extruder and the mean bulk's temperature is measured when the emissivity is lower than one.

Furthermore it is shown that it is possible to measure the residence time distribution on line with an infrared thermometer, by taking advantage of its sensibility on a changing surface emissivity. Measurements with classical methods shows the same residence time distribution as obtained with the infrared spectroscopy. The advantage of this method is its wide range of applications, such like as the use in pressure zones, for a wide range of temperature and to measure on line the local residence time distribution all along the screw.

Reactive Blending in a Twin Screw Extruder

We studied the morphology of a reactive blend, constituted by an EVA/EMA phase dispersed in a polypropylene matrix. The dispersed phase was crosslinked in-situ during the extrusion through a transesterification reaction, catalysed by dibutyltin oxide. Rheological studies allowed to define the changes in rheological behaviour during the crosslinking reaction. Using a flow model developed for twin screw extruders, we computed the reaction extent along the screws and the corresponding blend morphology using a very simple approach. Theoretical results underestimate the extent of the reaction, but explain qualitatively the general tendencies when varying operating parameters.

Morphological Changes of a Polymer Blend into a Twin-Screw Extruder

The dispersion of an elastomeric phase (blend of two miscible copolymers: ethylene-vinyl acetate and ethylene-methyl acrylate) in a polypropylene matrix along a corotating twin-screw extruder was studied experimentally. A sliding barrel allowed a direct access to the screws and thus permitted a rapid cooling and sampling. The dispersion of the elastomeric phase was controlled by scanning electron microscopy and the size distribution was obtained by image analysis. The particle size distribution was measured at different locations along the screws in order to quantify the evolution of the morphology. Complementary studies were carried out on a pre-shearing rheometer (Rheoplast) in order to study the influence of the mechanical treatment upon particle size. The dispersion of the elastomeric phase was observed at the capillary exit by the above mentioned techniques. The results of these different experiments enhance the importance of the melting mechanism and put in evidence that the final morphology of the blend is controlled by the opposite mechanisms of break up and coalescence.

Localized hypertrophic neuropathy of the sciatic nerve in children: MRI findings

BACKGROUND

Localized hypertrophic neuropathy (LHN) of the sciatic nerve in children is a rare condition characterized by a painless neurological deficit in the sciatic nerve territory.

OBJECTIVE

To demonstrate the role of MRI using a specific protocol and describe the primary findings in LHN.

MATERIALS AND METHODS

Imaging in four children (age 2 years to 12 years) is presented. All children presented with lower limb asymmetry. Three had a steppage gait. LHN was confirmed by electrophysiological studies and by MRI of the whole sciatic nerve with a dedicated protocol covering the lumbar spine and the lower limb.

RESULTS

There were four direct MRI findings: (1) linear and focal hypertrophy with progressive enlargement of a peripheral nerve or plexus diameter, (2) abnormal hyperintensity of the nerve on T2-weighted images, (3) preserved fascicular configuration, and (4) variable enhancement after intravenous gadolinium administration. In addition there were atrophy and fatty infiltration of innervated muscles. MRI was helpful for determining the extent of lesions and in excluding peripheral nerve compression or tumour.

CONCLUSION

MRI of the whole sciatic nerve is the method of choice for diagnosing LHN of the sciatic nerve.

[Systematic sanitation of dairy herds with mastitis caused by Staphylococcus aureus]

Several strategies are known for sanitizing dairy herd problems caused by Staphylococcus (S.) aureus. They mostly consist of general management measures but specific decision-making at an individual animal level has not been described. A sanitation program in the form of a process chart developed by the Bern Clinic for Ruminants was undertaken in 10 dairy herds with this problem. In an affected herd the cows were divided into 3 groups: healthy, suspect, infected. Three milk samples (MS), taken at two-week intervals were cultivated. The cows were grouped according to the culture results. To measure the success of the sanitation program, the key figures «theoretical tank somatic cell count» (target < 150,000 SCC/ml) and «percentage of cows over limit» (limit: 150'00 SCC/ml, target < 20 %) were used. These were compared with the corresponding key figures from dairy herds, which were followed-up by the Bern Clinic for Ruminants (control herds). The problem herd sanitation program lasted between 2 and 21 months. A total of 1598 MS were analyzed, of which 241 (15 %) were S. aureus positive (15 %). At the end of the sanitation the key figures between problem herds and control herds were similar. The sanitation program has proved to be practical. The detection of S. aureus positive cows proved to be reliable and the udder health of the herd could be significantly improved.

[Personnel planning in the emergency department. Optimized patient care round the clock]

In recent years the number of interdisciplinary emergency departments (ED) at hospitals in Germany has increased. The model of decentralized first contact units for each medical discipline has been abandoned, last but not least due to economic considerations. While decentralized units could be staffed with personnel from each discipline there is much controversy surrounding the question of which kind of doctor is best suited for a centralized ED. The development of programs providing the necessary qualification for German ED physicians in the future by working groups of several specialties is still nascent and has not yet produced concrete results. However, even without these special training programs, the management of critically ill or severely injured patients in the ED is paramount. The smooth operation of centralized EDs is therefore important. Therefore, taking into account economical aspects, qualification and number of available personnel, this article introduces a staffing concept as a rational basis for an optimized patient management in centralized EDs in Germany. Taking the patient characteristics, the specific treatment modalities and the number of admissions to the ED into account, this paper will determine treatment time per patient and the necessary number of physicians, as well as an optimized staffing model for EDs.

Pharmacokinetic Study of Gadolinium-DOTA in Control and Streptozocin Diabetic Rats

The pharmacokinetics of gadolinium tetraazacyclododecanetetraacetic acid (Gd-DOTA), a contrast agent used in magnetic resonance imaging, have been evaluated in control and streptozocin-diabetic rats of different ages. In control rats, an age-related decrease in the Gd-DOTA elimination rate was noted, supported by a significantly lower apparent total body clearance and a significantly higher mean residence time. In diabetic rats, a similar but less important age-related change in the mean residence time and the apparent total body clearance was observed. Regardless of age-related differences in the pharmacokinetic parameters, a diabetic state induced several alterations in the Gd-DOTA pharmacokinetic parameters. The apparent total body clearance was significantly higher and the mean residence time significantly lower in diabetic rats indicating a higher elimination rate of Gd-DOTA. An important age-related increase in the volume of distribution at steady-state was noted in diabetic rats.

Characterization, anti-oxidative and anti-inflammatory effects of Costa Rican noni juice (Morinda citrifolia L.)

AIM OF THE STUDY

Noni fruit (Morinda citrifolia L.) juice has been used for more than 2000 years in Polynesia as a traditional folk medicine. The aim of the present study was to finely characterize noni juice from Costa Rica and to evaluate its anti-oxidative and anti-inflammatory activities.

MATERIALS AND METHODS

A microfiltrated noni juice was prepared with Costarican nonis. HPLC-DAD and Electro Spray Ionization Mass Spectrometric detection (HPLC-ESI-MS) were used to identify phenolic compounds and iridoids. The anti-oxidative activity of noni juice was measured in vitro by both Oxygen Radical Absorbance Capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging methods. The anti-inflammatory effects of noni juice were investigated in vitro by: measuring its effect on nitric oxide and prostaglandin E2 production by activated macrophages, evaluating its inhibitory activities on cyclooxygenase (COX)-1 and -2 and in vivo on a carrageenan-induced paw oedema model in rats.

RESULTS

Several polyphenols belonging to the coumarin, flavonoid and phenolic acid groups, and two iridoids were identified. Noni juice demonstrated a mean range free radical scavenging capacity. Furthermore, it also reduced carrageenan-induced paw oedema, directly inhibited cyclooxygenase COX-1 and COX-2 activities and inhibited the production of nitric oxide (NO) and prostaglandins E(2) (PGE(2)) in activated J774 cells, in a dose dependent manner.

CONCLUSIONS

This study showed that noni's biological effects include: (1) anti-oxidant properties probably associated with phenolic compounds, iridoids and ascorbic acid and (2) anti-inflammatory action through NO and PGE(2) pathways that might also be strengthened by anti-oxidant effects.