Targeting siglecs--a novel pharmacological strategy for immuno- and glycotherapy

The immune system must be tightly held in check to avoid bystander tissue damage as well as autoreactivity caused by overwhelming immune reactions. A novel family of immunoregulatory, carbohydrate-binding receptors, the Siglecs (sialic acid binding immunoglobulin-like lectins), has received particular attention in light of their capacity to mediate cell death, anti-proliferative effects and to regulate a variety of cellular activities. Siglec receptors are mainly expressed on leukocytes in a cell type-specific and differentiation-dependent manner. Siglecs might potentially be exploited as targets of novel immune- and glycotherapeutics for cell-directed therapies in autoimmune and allergic diseases, as well as in haematologic malignancies. Here we present novel insights on structural and functional characteristics, expression patterns and evolutionary aspects of Siglecs and their ligands. Pharmacological strategies using Siglec agonistic cross-linking therapeutics, such as monoclonal or engineered antibodies, intravenous immunoglobulin (IVIG), or glycomimetics are discussed. Modulation of immune responses by targeting Siglecs using agonistic or antagonistic therapeutics may have important clinical implications and may pave the way for novel pharmacological avenues for the treatment of autoimmune and allergic diseases or for tumor immunotherapy.

Morphological and functional 3-Tesla magnetic resonance imaging of saphenous vein coronary artery bypass grafts

Evaluation of a novel non-invasive tool for postoperative follow-up of patients postelective saphenous vein coronary artery bypass graft (CABG) was performed. Ten patients were included. Their bypass grafts supplied the right coronary artery (7), marginal branches (1), diagonal branches (2), and the circumflex artery (n=1). Each bypass was examined intraoperatively using Doppler flow measurement. Patients were examined with a 3-Tesla magnetic resonance imaging (MRI) scanner (MAGNETOM Verio, Siemens, Erlangen, Germany) within one week postsurgery using MR-angiography with an intravasal contrast agent and velocity encoded phase-contrast flow measurements. Intraoperative Doppler flow measurements revealed regular flow patterns in all vascular territories supplied. The median intraoperative flow rate was 50 ml/min with an inter-quartile range (IQR) of 42-70 ml/min. The clinical postoperative course was uneventful. MRI showed all grafts to be patent. The median postoperative flow rate was 50 ml/min (IQR: 32-65 ml/min). MRI flow rates agreed well with intraoperative Doppler flow measurements (mean difference: -2.8±20.1 ml/min). This initial study demonstrates that 3-Tesla MRI flow measurements correlated well with Doppler thus reconfirming the graft patency postCABG. Further refinement and broader application of this technique may facilitate follow-up postCABG potentially replacing empiric clinical judgment by reliable non-invasive imaging.

Constrained pattern of viral evolution in acute and early HCV infection limits viral plasticity

Cellular immune responses during acute Hepatitis C virus (HCV) and HIV infection are a known correlate of infection outcome. Viral adaptation to these responses via mutation(s) within CD8+ T-cell epitopes allows these viruses to subvert host immune control. This study examined HCV evolution in 21 HCV genotype 1-infected subjects to characterise the level of viral adaptation during acute and early HCV infection. Of the total mutations observed 25% were within described CD8+ T-cell epitopes or at viral adaptation sites. Most mutations were maintained into the chronic phase of HCV infection (75%). The lack of reversion of adaptations and high proportion of silent substitutions suggests that HCV has structural and functional limitations that constrain evolution. These results were compared to the pattern of viral evolution observed in 98 subjects during a similar phase in HIV infection from a previous study. In contrast to HCV, evolution during acute HIV infection is marked by high levels of amino acid change relative to silent substitutions, including a higher proportion of adaptations, likely reflecting strong and continued CD8+ T-cell pressure combined with greater plasticity of the virus. Understanding viral escape dynamics for these two viruses is important for effective T cell vaccine design.

Structural and procedural properties important in promoting bio-enterprises as alternative livelihoods to pastoral and agro-pastoral livelihoods

Alternative livelihoods to pastoral and agro-pastoral livelihoods are increasingly gaining attention in rural development but few empirical evidence exist on how to go about supporting such initiatives. As pastoral and agro-pastoral production conditions change due to various factors including market conditions, climate variability and change, pastoralists and agro-pastoralists are increasingly faced with the challenge of finding alternative livelihoods. Bio-enterprises offer such alternatives or complementary activities for rural actors to adapt to changing socio-ecological conditions. This study examines the roles of bio-enterprise initiatives from a livelihood perspective and identifies the features important for such initiatives to reduce poverty and improve the adaptive capacities of pastoralists and agro-pastoralists. It draws on four different bio-enterprise initiatives on agro-pastoral and pastoral livelihoods and on improved natural resources management (NRM) in the drylands of Kenya. Data were collected through interviews, focus group discussions, informal discussions and the study of reports. Results shows among other factors that diversification into enterprises requires cooperation among the stakeholders with their varying experiences in development, NRM and business development. Other factors such as sustained financial support, capacity development to survive the market introduction phase, as well as quantity and quality of the product, are critical. Mentoring proved to be a driver of success in some initiatives.

Genetic and functional characterization of the NanA sialidase from Clostridium chauvoei

ABSTRACT: Clostridium chauvoei is the causative agent of blackleg, a wide spread serious infection of cattle and sheep with high mortality. In this study we have analyzed the sialidase activity of the NanA protein of C. chauvoei and cloned the sialidase gene nanA. Sialidase is encoded as a precursor protein of 722 amino acids with a 26 amino acid signal peptide. The mature sialidase has a calculated molecular mass of 81 kDa and contains the carbohydrate binding module 32 (CBM32, or F5/8 type C domain), the sialic acid binding module CBM40 and the enzymatically active sialidase domain found in all pro- and eukaryotic sialidases. Sialidase activity does not require the CBM32 domain. The NanA protein is secreted by C. chauvoei as a dimer. The nanA gene was found to be conserved and sialidase activity was found in C. chauvoei strains isolated over a period of 50 years from various geographical locations. Antiserum directed against a recombinant 40 kDa peptide containing CBM40 and part of the enzymatically active domain of NanA neutralized the secreted sialidase activity of all C. chauvoei strains tested.

Social Cognition And Functional Brain Imaging: Extending The Broader Autism Phenotype

Evidence suggests that the social cognition deficits prevalent in autism spectrum disorders (ASDs) are widely distributed in first degree and extended relatives. This ¿broader autism phenotype¿ (BAP) can be extended into non-clinical populations and show wide distributions of social behaviors such as empathy and social responsiveness ¿ with ASDs exhibiting these behaviors on the lower ends of the distributions. Little evidence has previously shown relationships between self-report measures of social cognition and more objective tasks such as face perception in functional magnetic resonance imaging (fMRI) and event-related potentials (ERPs). In this study, three specific hypotheses were addressed: a) increased social ability, as measured by an increased Empathy Quotient, decreased Social Responsiveness Scale (SRS-A) score, and increased Social Attribution Task score, will predict increased activation of the fusiform gyrus in response to faces as compared to houses; b) these same measures will predict N170 amplitude and latency showing decreased latency and increased amplitude for faces as compared to houses with increased social ability; c) increased amygdala volume will predict increased fusiform gyrus activation when viewing faces as compared to houses. Findings supported all of the hypotheses. Empathy scores significantly predicted both right FFG activation [F(1,20) = 4.811, p = .041, ß = .450, R2 = 0.20] and left FFG activation [F(1,20) = 7.70, p = .012, ß = .537, R2 = 0.29]. Based on ERP results increased right lateralization face-related N170 was significantly predicted by the EQ [F(1,54) = 6.94, p = .011, ß = .338, R2 = 0.11]. Finally, total amygdala volume significantly predicted right [F(1,20) = 7.217, p = .014, ß = .515, R2 = 0.27] and left [F(1,20) = 36.77, p < .001, ß = .805, R2 = 0.65] FFG activation. Consistent with the a priori hypotheses, traits attributed to the BAP can significantly predict neural responses to faces in a non-clinical population. This is consistent with the face processing deficits seen in ASDs. The findings presented here contribute to the extension of the BAP from unaffected relatives of individuals with ASDs to the general population. These findings also give continued evidence in support of a continuous distribution of traits found in psychiatric illnesses in place of a traditional, dichotomous ¿all-or-nothing¿ diagnostic framework of neurodevelopmental and neuropsychiatric disorders.

Vascular endothelial growth factor induces contralesional corticobulbar plasticity and functional neurological recovery in the ischemic brain

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor, which also has neuroprotective activity. In view of these dual actions on vessels and neurons, we were interested whether VEGF promotes long distance axonal plasticity in the ischemic brain. Herein, we show that VEGF promotes neurological stroke recovery in mice when delivered in a delayed way starting 3 days after middle cerebral artery occlusion. Using anterograde tract-tracing experiments that we combined with histochemical and molecular biological studies, we demonstrate that although VEGF promoted angiogenesis predominantly in the ischemic hemisphere, pronounced axonal sprouting was induced by VEGF in the contralesional, but not the ipsilesional corticobulbar system. Corticobulbar plasticity was accompanied by the deactivation of the matrix metalloproteinase MMP9 in the lesioned hemisphere and the transient downregulation of the axonal growth inhibitors NG2 proteoglycan and brevican and the guidance molecules ephrin B1/2 in the contralesional hemisphere. The regulation of matrix proteinases, growth inhibitors, and guidance molecules offers insights how brain plasticity is controlled in the ischemic brain.

A Comparative Study on Higher Education Acts in Bulgaria, Hungary, Poland, Romania and Russia

The original aim of this project was to describe and analyse the higher education acts in force in five Central and Eastern European countries at present, trying to understand the dependence of higher education on the historical traditions, national peculiarities and all-European tendencies. The description and comparison of the main aspects of higher education was supplemented by a study of the possibilities of transferring experience in the field between the five countries and possible solutions to implementing foreign structural and functional models. Questions covered included the role of the state in the management of higher education, the structures of the higher education systems and the organisation of institutions, academic autonomy and the classifications of academic teaching staff, the main trends in the recent development of research, academic degrees, the accreditation of higher education institutions, and the financing of higher education. Popov found that it was almost impossible to understand the dependence of higher education on historical traditions and national peculiarities purely through a study of the relevant legislation. Education traditions in these countries have twice been broken, once with the start of communism (1917 in Russia and 1944-45 in Bulgaria, Hungary, Poland and Romania) and for a second time at the beginning of the 1990s. The most recent higher education acts in all five countries studied have abandoned many of their historical and national traditions, following instead all-European trends as determined by Western Europe, and the project included a study of the dependence on these trends. There were also difficulties in comparing some aspects of higher education as it depended on how far a given aspect has different or common features in the different countries and to what extent the application is comparable. While many possible areas for transferring experience between the five countries were identified, Popov concentrated on those where he felt that there was a real practical possibility of application in view of national academic differences. He concluded by defining some of the challenges facing each country in the field of higher education and by making some predictions as to the developments in the different countries.

Family Anomie and Juvenile Deliquency in Post-Communist Romania

The sensitivity of crime rates to social, economic and political influences has long aroused the interest of sociologists who have attempted to explain what kind of relationships might be associated with variations in crime rates between different social groups at different times. The earliest views were put forward by Emil Durkheim, and while later writers have developed (R.K. Merton, L. Srole, A, K. Cohen, etc.) have developed some aspects of his ideas further, his basic ideas of the divorce of the individual from normative standards and the lack of social integration are still valid. Ms. Voicu-Minea looked at the theoretical background in detail but then limited it to a specific social group, the family, asking first why certain individual within vulnerable families and/or negative social influences commit offences while others do not. In modern times the family has undergone massive structural and functional changes. Its former economic function, which once endowed it with a great capacity for social inclusion, has generally vanished, while its formerly crucial role in children's education has been massively reduced. These changes, which are still not complete, can lead to dysfunction and in certain social contexts such as that in post-communist Romanian society, this risk of dysfunction is still greater as unfavourably social circumstances more easily affect such families. The number of cases of juvenile delinquency in Romania has increased sharply ever since the end of the communist system and in 1996 reached the level of 18,317 cases. The sample examined included 1012 juvenile delinquents aged between 14 and 18, taken from all areas of Bucharest. Over 80% of charges related to theft, with more serious offences being relatively rare. The children underwent a series of psychological tests, accompanied by a questionnaire relating to family situation. The results showed that juvenile delinquency in Romania is overwhelmingly male, with 91.8% of offences being committed by boys. Two thirds of the research group were under the age of 16 and only just over one third attended school, with over half having left school before the legal age. While the majority of subjects had a lower than average level of education, they did not always recognise this, with two thirds seeing their level of education as being as good as or better than average. Nearly half the children (43%) did not live with both natural parents and majority came from families with three or more children. This applied both to their original families and to the families in which they were living at the time of the survey. The overwhelming majority of families were living in or around Bucharest, but under one third originated from there. Almost 25% of parents were under-schooled and around one third were unqualified workers. At least 30% of families lived in inadequate accommodation and family incomes were generally low. Ms. Voicu-Minea does however point out that over half the minors from the sample saw their family income as satisfactory or even more than satisfactory. When factors such as bad relationships between parents, corporal punishment, alcohol consumption and criminal records of family members were taken into account, the picture was bleak, making it understandable why over 36% of subjects had run away from home at least once, and in many cases repeatedly and for longer periods. The overwhelming majority of offences (80.8%) were committed in groups of between 2 and 11 persons, usually "friends" but in about 10% of cases member's of the family. IQ tests put about 75% of the sample at slightly under average, the difference being too slight to account for the behaviour problems of the majority. Personality tests, however, showed a different picture. Over 70% of those tested manifested an acute need of tenderness and a similar number a high level of potential aggressiveness. Almost half of the minors expressed such feelings as intolerance or a desire for revenge, and Ms. Voicu-Minea found a clear weakness of the Self. Around half the sample expressed sentiments of abandonment, renunciation and solitude.