Immunosuppression and resultant viral persistence by specific viral targeting of dendritic cells

Among cells of the immune system, CD11c(+) and DEC-205(+) splenic dendritic cells primarily express the cellular receptor (alpha-dystroglycan [alpha-DG]) for lymphocytic choriomeningitis virus (LCMV). By selection, strains and variants of LCMV that bind alpha-DG with high affinity are associated with virus replication in the white pulp, show preferential replication in a majority of CD11c(+) and DEC-205(+) cells, cause immunosuppression, and establish a persistent infection. In contrast, viral strains and variants that bind with low affinity to alpha-DG are associated with viral replication in the red pulp, display minimal replication in CD11c(+) and DEC-205(+) cells, and generate a robust anti-LCMV cytotoxic T lymphocyte response that clears the virus infection. Differences in binding affinities can be mapped to a single amino acid change in the viral glycoprotein 1 ligand that binds to alpha-DG. These findings indicate that receptor-virus interaction on dendritic cells in vivo can be an essential step in the initiation of virus-induced immunosuppression and viral persistence.

Difficidin and bacilysin produced by plant-associated Bacillus amyloliquefaciens are efficient in controlling fire blight disease

Representatives of Bacillus amyloliquefaciens were shown to possess biocontrol activity against fire blight, a serious disease of orchard trees caused by Erwinia amylovora. Genome analysis of B. amyloliquefaciens FZB42 identified gene clusters responsible for synthesis of several polyketide compounds with antibacterial action. We show here that the antibacterial polyketides difficidin and to a minor extent bacillaene act efficiently against E. amylovora. Surprisingly, a mutant strain blocked in the production of difficidin (CH8 Deltadfn) inhibited growth of E. amylovora and suppressed fire blight disease nearly in the same range as the wild type. In addition, a sfp mutant (CH3 Deltasfp) unable to synthesize non-ribosomally lipopeptides and polyketides did still suppress growth of E. amylovora, suggesting that besides action of polyketides another antagonistic principle exist. A double mutant (RS06 Deltasfp Deltabac) devoid in polyketide and bacilysin synthesis was unable to suppress growth of E. amylovora indicating that the additional inhibitory effect is due to production of bacilysin, a dipeptide whose synthesis does not depend on Sfp. We propose to use B. amyloliquefaciens strains with enhanced synthesis of difficidin and/or bacilysin for development of biocontrol agents efficient against fire blight disease.

Stress responsivity and socioeconomic status: a mechanism for increased cardiovascular disease risk?

AIMS

Low socioeconomic status is associated with increased cardiovascular disease risk. We hypothesized that psychobiological pathways, specifically slow recovery in blood pressure and heart rate variability following mental stress, partly mediate social inequalities in risk.

METHODS AND RESULTS

Participants were 123 men and 105 women in good health aged 47-58 years drawn from the Whitehall II cohort of British civil servants. Grade of employment was the indicator of socioeconomic status. Cardiovascular measures were monitored during performance of two behavioural tasks, and for 45 min following stress. Post-stress return of blood pressure and heart rate variability to resting levels was less complete after 45 min in the medium and low than in the high grade of employment groups. The odds of failure to return to baseline by 45 min in the low relative to the high grade of employment groups were 2.60 (95% CI 1.20-5.65) and 3.85 (1.48-10.0) for systolic and diastolic pressure, respectively, and 5.19 (1.88-18.6) for heart rate variability, adjusted for sex, age, baseline levels and reactions to tasks. Subjective ratings of task difficulty, involvement and stress did not differ by socioeconomic status.

CONCLUSIONS

Lower socioeconomic status is associated with delayed recovery in cardiovascular function after mental stress. Impaired recovery may reflect heightened allostatic load, and constitute a mechanism through which low socioeconomic status enhances cardiovascular disease risk.

Differences in affinity of binding of lymphocytic choriomeningitis virus strains to the cellular receptor alpha-dystroglycan correlate with viral tropism and disease kinetics

alpha-Dystroglycan (alpha-DG) was recently identified as a receptor for lymphocytic choriomeningitis virus (LCMV) and several other arenaviruses, including Lassa fever virus (W. Cao, M. D. Henry, P. Borrow, H. Yamada, J. H. Elder, E. V. Ravkov, S. T. Nichol, R. W. Compans, K. P. Campbell, and M. B. A. Oldstone, Science 282:2079-2081, 1998). Data presented in this paper indicate that the affinity of binding of LCMV to alpha-DG determines viral tropism and the outcome of infection in mice. To characterize this relationship, we evaluated the interaction between alpha-DG and several LCMV strains, variants, and reassortants. These viruses could be divided into two groups with respect to affinity of binding to alpha-DG, dependence on this protein for cell entry, viral tropism, and disease course. Viruses that exhibited high-affinity binding to alpha-DG displayed a marked dependence on alpha-DG for cell entry and were blocked from infecting mouse 3T6 fibroblasts by 1 to 4 nM soluble alpha-DG. In addition, high-affinity binding to alpha-DG correlated with an ability to infiltrate the white pulp (T-dependent) area of the spleen, cause ablation of the cytotoxic T-lymphocyte (CTL) response by day 7 postinfection, and establish a persistent infection. In contrast, viruses with a lower affinity of binding to alpha-DG were only partially inhibited from infecting alpha-DG(-/-) embryonic stem cells and required a concentration of soluble alpha-DG higher than 100 nM to prevent infection of mouse 3T6 fibroblasts. These viruses that bound at low affinity were mainly restricted to the splenic red pulp, and the host generated an effective CTL response that rapidly cleared the infection. Reassortants of viruses that bound to alpha-DG at high and low affinities were used to map genes responsible for the differences described to the S RNA, containing the virus attachment protein glycoprotein 1.

Molecular analysis of the interaction of LCMV with its cellular receptor [alpha]-dystroglycan

alpha-Dystroglycan (DG) has been identified as the cellular receptor for lymphocytic choriomeningitis virus (LCMV) and Lassa fever virus (LFV). This subunit of DG is a highly versatile cell surface molecule that provides a molecular link between the extracellular matrix (ECM) and a beta-DG transmembrane component, which interacts with the actin-based cytoskeleton. In addition, DG exhibits a complex pattern of interaction with a wide variety of ECM and cellular proteins. In the present study, we characterized the binding of LCMV to alpha-DG and addressed the role of alpha-DG-associated host-derived proteins in virus infection. We found that the COOH-terminal region of alpha-DG's first globular domain and the NH2-terminal region of the mucin-related structures of alpha-DG together form the binding site for LCMV. The virus-alpha-DG binding unlike ECM alpha-DG interactions was not dependent on divalent cations. Despite such differences in binding, LCMV and laminin-1 use, in part, an overlapping binding site on alpha-DG, and the ability of an LCMV isolate to compete with laminin-1 for receptor binding is determined by its binding affinity to alpha-DG. This competition of the virus with ECM molecules for receptor binding likely explains the recently found correlation between the affinity of LCMV binding to alpha-DG, tissue tropism, and pathological potential. LCMV strains and variants with high binding affinity to alpha-DG but not low affinity binders are able to infect CD11c+ dendritic cells, which express alpha-DG at their surface. Infection followed by dysfunction of these antigen-presenting cells contributes to immunosuppression and persistent viral infection in vivo.

Hydrogen peroxide as a potent bacteriostatic antibiotic: implications for host defense

Host defense against bacterial pathogens in higher organisms is mediated in part by the generation of reactive oxygen species (ROS) by PMN. In this study, we determined the following effects of exposure of constant concentrations of H2O2 on E. coli in a culture continuously monitored for H2O2 concentration, numbers, and viabilities of cells: (1) E. coli growth rates monitored for 1 h were profoundly affected by concentrations of H2O2, between 25-50 microM. (2) Complete bacteriostasis was observed at 100 microM. (3) Significant cell killing was not observed until the concentration of H2O2 was greater than 500 microM. (4) Bacteriostatic (25-50 microM) concentrations of H2O2 appeared not to be toxic to human skin fibroblasts for a 2-h exposure. (4) Bacteriostasis by H2O2 could not be explained by metabolic inhibition, because intracellular ATP levels were not compromised at bacteriostatic doses of H2O2. (5) Measurements of H2O2 concentrations in subcutaneous abscess fluid infected with both E. coli and S. aureus indicated prevailing concentrations of the oxidant consistent with a proposed role of H2O2 in host defense.

Cell adhesion molecules NgCAM and axonin-1 form heterodimers in the neuronal membrane and cooperate in neurite outgrowth promotion

The axonal surface glycoproteins neuronglia cell adhesion molecule (NgCAM) and axonin-1 promote cell-cell adhesion, neurite outgrowth and fasciculation, and are involved in growth cone guidance. A direct binding between NgCAM and axonin-1 has been demonstrated using isolated molecules conjugated to the surface of fluorescent microspheres. By expressing NgCAM and axonin-1 in myeloma cells and performing cell aggregation assays, we found that NgCAM and axonin-1 cannot bind when present on the surface of different cells. In contrast, the cocapping of axonin-1 upon antibody-induced capping of NgCAM on the surface of CV-1 cells coexpressing NgCAM and axonin-1 and the selective chemical cross-linking of the two molecules in low density cultures of dorsal root ganglia neurons indicated a specific and direct binding of axonin-1 and Ng-CAM in the plane of the same membrane. Suppression of the axonin-1 translation by antisense oligonucleotides prevented neurite outgrowth in dissociated dorsal root ganglia neurons cultured on an NgCAM substratum, indicating that neurite outgrowth on NgCAM substratum requires axonin-1. Based on these and previous results, which implicated NgCAM as the neuronal receptor involved in neurite outgrowth on NgCAM substratum, we concluded that neurite outgrowth on an NgCAM substratum depends on two essential interactions of growth cone NgCAM: a trans-interaction with substratum NgCAM and a cis-interaction with axonin-1 residing in the same growth cone membrane.

Neurite fasciculation mediated by complexes of axonin-1 and Ng cell adhesion molecule

Neural cell adhesion molecules composed of immunoglobulin and fibronectin type III-like domains have been implicated in cell adhesion, neurite outgrowth, and fasciculation. Axonin-1 and Ng cell adhesion molecule (NgCAM), two molecules with predominantly axonal expression exhibit homophilic interactions across the extracellular space (axonin- 1/axonin-1 and NgCAM/NgCAM) and a heterophilic interaction (axonin-1-NgCAM) that occurs exclusively in the plane of the same membrane (cis-interaction). Using domain deletion mutants we localized the NgCAM homophilic binding in the Ig domains 1-4 whereas heterophilic binding to axonin-1 was localized in the Ig domains 2-4 and the third FnIII domain. The NgCAM-NgCAM interaction could be established simultaneously with the axonin-1-NgCAM interaction. In contrast, the axonin-1-NgCAM interaction excluded axonin-1/axonin-1 binding. These results and the examination of the coclustering of axonin-1 and NgCAM at cell contacts, suggest that intercellular contact is mediated by a symmetric axonin-12/NgCAM2 tetramer, in which homophilic NgCAM binding across the extracellular space occurs simultaneously with a cis-heterophilic interaction of axonin-1 and NgCAM. The enhanced neurite fasciculation after overexpression of NgCAM by adenoviral vectors indicates that NgCAM is the limiting component for the formation of the axonin-12/NgCAM2 complexes and, thus, neurite fasciculation in DRG neurons.

Prospective multicenter study of bronchiolitis: predicting safe discharges from the emergency department

OBJECTIVE

Bronchiolitis is the leading cause of hospitalization for infants. Our objective was to identify factors associated with safe discharge to home from the emergency department.

METHODS

We conducted a prospective cohort study during 2 consecutive bronchiolitis seasons, from 2004 to 2006. Thirty US emergency departments contributed data. All patients were < 2 years of age and had a final emergency department attending physician diagnosis of bronchiolitis. Using multivariate logistic regression, a low-risk model was developed with a random half of the data and then validated with the other half.

RESULTS

Of 1456 enrolled patients, 837 (57%) were discharged home from the emergency department. The following factors predicted safe discharge to home: age of > or = 2 months, no history of intubation, a history of eczema, age-specific respiratory rates (< 45 breaths per minute for 0-1.9 months, < 43 breaths per minute for 2-5.9 months, and < 40 breaths per minute for 6-23.9 months), no/mild retractions, initial oxygen saturation of > or = 94%, fewer albuterol or epinephrine treatments in the first hour, and adequate oral intake. The importance of each factor varied slightly according to age, but the comprehensive model (developed and validated for all children < 2 years of age) yielded an area under the receiver operating characteristic curve of 0.81, with a good fit of the data.

CONCLUSIONS

This large multicenter study of children presenting to the emergency department with bronchiolitis identified several factors associated with safe discharge, including cut points for respiratory rate and oxygen saturation. Although the low-risk model requires further study, we believe that it will assist clinicians evaluating children with bronchiolitis and may help reduce some unnecessary hospitalizations.

Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

Comparative efficacies of ciprofloxacin, pefloxacin, and vancomycin in combination with rifampin in a rat model of methicillin-resistant Staphylococcus aureus chronic osteomyelitis

The efficacies of the quinolones ciprofloxacin and pefloxacin alone and in combination with rifampin were compared with those of vancomycin alone and in combination with rifampin in a rat model of chronic osteomyelitis caused by methicillin-resistant Staphylococcus aureus. Neither the quinolones nor vancomycin alone was effective in reducing titers of organisms in bone after therapy, while rifampin alone was effective. All combination regimens with rifampin were more effective than the regimen with rifampin alone was, although these differences did not achieve statistical significance. Rifampin-resistant isolates were detected rarely. Quinolone-rifampin combination regimens may offer a nonparenteral option for the treatment of chronic osteomyelitis caused by methicillin-resistant S. aureus.

Intracellular signaling is changed after clustering of the neural cell adhesion molecules axonin-1 and NgCAM during neurite fasciculation

Neural cell adhesion molecules of the immunoglobulin/fibronectin type III family on axons have been implicated in promotion of neurite outgrowth, fasciculation, and the mediation of specific cell adhesion. The present study demonstrates that two of these molecules on dorsal root ganglion neurons are associated with distinct protein kinases, axonin-1 with the src-related nonreceptor tyrosine kinase fyn and NgCAM with a casein kinase II-related activity and a serine/ threonine kinase related to S6 kinase. When neurites grew without contacts involving axonin-1 and NgCAM, strong fyn kinase activity was associated with axonin-1, whereas the NgCAM-associated kinase activities were low. Clustering of axonin-1 with NgCAM induced by the formation of cell-cell contacts correlated with a reduction of the axonin-1-associated fyn activity and an increased phosphorylation of NgCAM by the associated casein kinase II-related activity. Thus, axonin-1 and NgCAM trigger distinctive intracellular signals during in vitro differentiation depending on their state of association.

A novel, soluble homologue of the human IL-10 receptor with preferential expression in placenta

The cytokine receptor family type 2 (CRF2) comprises receptors for important immunomediators like interferons and interleukin-10 (IL-10). We identified a novel member of this family which represents the first exclusively soluble receptor in this group and was therefore designated as CRF2-soluble 1 (CRF2-s1). The CRF2-s1 gene covers about 28 kb and is located on chromosome 6 in close proximity to the CRF2 members interferon (IFN)-gamma receptor 1 and IL-20 receptor 1. It comprises seven exons and generates two different mRNA splice variants, CRF2-s1-long and CRF2-s1-short. CRF2-s1-long and CRF2-s1-short encode proteins of 263 and 231 amino acids, respectively. A comparison of predicted protein structures led to the postulation that each receptor variants binds a different ligand. Quantitative analysis of human mRNA expression revealed a very restricted pattern for both splice forms. CRF2-s1 turned out to be the first member of this receptor family which was expressed neither in resting nor in stimulated leucocyte populations. CRF2-s1-long was only expressed in placenta, whereas CRF2-s1-short was additionally expressed in human mammary gland and, at a lower level, in skin, spleen, thymus and stomach. The preferential expression of CRF2-s1 in placenta suggests a role for this receptor in establishing and maintaining successful pregnancy.

Relationship between antibiotic concentration in bone and efficacy of treatment of staphylococcal osteomyelitis in rats: azithromycin compared with clindamycin and rifampin

We examined the effect of azithromycin (CP-62,993), a new oral macrolide-like antibiotic, alone and in combination with rifampin, as treatment for experimental staphylococcal osteomyelitis. Clindamycin was used as a comparison drug. Rats (n = 10 to 15 per group) were infected by direct instillation of Staphylococcus aureus into the tibial medullary cavity. After 10 days, 21-day treatments with azithromycin (50 mg/kg of body weight, once daily, by the oral route), rifampin (20 mg/kg, once daily, subcutaneously), or clindamycin (90 mg/kg, three times daily, by the oral route) were started. The drugs were used singly or in combination (azithromycin plus rifampin or clindamycin plus rifampin). Peak azithromycin concentrations in bone were > 30 times higher than levels in serum, but the drug had little effect on final bacterial titers (5.13 +/- 0.46 log10 CFU/g of bone; for controls, 6.54 +/- 0.28 log10 CFU/g). Clindamycin was more active than azithromycin (3.26 +/- 2.14 log10 CFU/g of bone; 20% of sterilized bones), but rifampin was the most active single drug (1.5 +/- 1.92 log10 CFU/g; 53% of sterilized bones). Therapy with rifampin or clindamycin alone was associated with the emergence of resistance. Rifampin plus azithromycin (0.51 +/- 1.08 log10 CFU/g of bone; 80% of sterilized bones) and rifampin plus clindamycin (0.87 +/- 1.34 log10 CFU/g of bone; 66% of sterilized bones) were the most active regimens. Thus, azithromycin is ineffective as a single drug for the treatment of experimental staphylococcal osteomyelitis, despite high levels in bone that markedly exceeded the MIC, but it may be an attractive partner drug for rifampin.

cAMP signalling in Trypanosoma brucei

Cyclic AMP was the first second messenger to be identified. After five decades of research, much is currently known about its biological functions and clinical implications. Several components of the cAMP signalling pathways, such as the G-protein coupled receptors and the phosphodiesterases, have become sensitive and specific drug targets for a host of clinical applications. Surprisingly, very little effort has been invested so far into the study of cAMP signalling in parasites, and its significance in host/parasite interaction. Our laboratory has embarked on a study of cAMP signalling in Trypanosoma brucei. A newly identified adenylyl cyclase, GRESAG4.4B, a member of a small family of closely related genes, is being used as a model molecule for investigating the mechanisms which control cyclase activity in the T. brucei cell. On the other hand, a number of genes for different families of cAMP-specific phosphodiesterases have been identified and characterised. One enzyme, TbPDE1, is coded for by a single-copy gene. Knock-outs of this gene display an almost normal phenotype in culture, indicating that TbPDE1 is not an essential enzyme under culture conditions. A second phosphodiesterase which is being studied in detail, TbPDE2A, is clearly different from TbPDE1, and it is coded for by a member of a small gene family containing about six similar, but non-identical genes. TbPDE2A, as TbPDE1, is specific for cAMP. In its N-terminal, it contains a GAF domain which may represent an allosteric cGMP-binding site. The other members of the TbPDE2 family all exhibit strongly conserved catalytic domains, but vary widely in their N-terminal regulatory domains. With regard to downstream signalling by the cAMP generated through the interplay of adenylyl cyclases and phosphodiesterases, we have recently identified a single-copy gene (TbRSU1) which codes for a putative regulatory subunit of the cAMP-regulated protein kinase A. This protein exhibits considerable similarity with its mammalian counterparts. Immunoprecipitation co-precipitates a protein kinase activity with the characteristics of protein kinase A.

Infection of dendritic cells by lymphocytic choriomeningitis virus

Dendritic cells (DCs) comprise the major antigen-presenting cells (APCs) of the host, uniquely programmed to stimulate immunologically naïve T lymphocytes. Viruses that can target and disorder the function of these cells enjoy a selective advantage. The cellular receptor for lymphocytic choriomeningitis virus (LCMV), Lassa fever virus (LFV), and several other arenaviruses is alpha-dystroglycan (alpha-DG). Among cells of the immune system, CD11c+ and DEC-205+ DCs primarily and preferentially express alpha-DG. By selection, strains and variants of LCMV generated as quasi-species that bind alpha-DG with high affinity replicate in the majority of CD11c+ and DEC-205+ (>75%) DCs, causing a generalized immunosuppression, and establish a persistent infection. In contrast, viral strains and variants that bind with low affinity to alpha-DG display minimal replication in CD11c+ and DEC-205+ DCs (<10%), rarely replicate in the white pulp, and generate a robust anti-LCMV CTL response that clears the virus infection. Hence, receptor-virus interaction on DCs in vivo is an essential step in the initiation of virus-induced immunosuppression and viral persistence. Investigation into the mechanism of how virus-infected DCs cause immunosuppression reveals loss of MHC class II surface expression and costimulatory molecules on surface of such DCs. As a consequence DCs are unable to act as APCs, initiate immune responses, and have a defect in migration into the T cell area. These data indicate that LCMV infection influences DC maturation and migration, leading to decreased T cell stimulatory capacity of DCs, events essential for the initiation of immune responses. Because several other viruses known to cause immunosuppression (HIV, measles) interact with DCs, the observations noted here are likely a common selective mechanism by which viruses also are able to evade the host's immune system.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Nuclear magnetization in gallium arsenide quantum dots at zero magnetic field

Optical and electrical control of the nuclear spin system allows enhancing the sensitivity of NMR applications and spin-based information storage and processing. Dynamic nuclear polarization in semiconductors is commonly achieved in the presence of a stabilizing external magnetic field. Here we report efficient optical pumping of nuclear spins at zero magnetic field in strain-free GaAs quantum dots. The strong interaction of a single, optically injected electron spin with the nuclear spins acts as a stabilizing, effective magnetic field (Knight field) on the nuclei. We optically tune the Knight field amplitude and direction. In combination with a small transverse magnetic field, we are able to control the longitudinal and transverse components of the nuclear spin polarization in the absence of lattice strain--that is, in dots with strongly reduced static nuclear quadrupole effects, as reproduced by our model calculations.

Characterization of TbPDE2A, a novel cyclic nucleotide-specific phosphodiesterase from the protozoan parasite Trypanosoma brucei

This study reports the identification and characterization of a cAMP-specific phosphodiesterase from the parasitic hemoflagellate Trypanosoma brucei. TbPDE2A is a class I phosphodiesterase. Its catalytic domain exhibits 30-40% sequence identity with those of all 11 mammalian phosphodiesterase (PDE) families, as well as with PDE2 from Saccharomyces cerevisiae, dunce from Drosophila melanogaster, and regA from Dictyostelium discoideum. The overall structure of TbPDE2A resembles that of human PDE11A in that its N-terminal region contains a single GAF domain. This domain is very similar to those of the mammalian PDE2, -5, -6, -10, and -11, where it constitutes a potential cGMP binding site. TbPDE2A can be expressed in S. cerevisiae, and it complements an S. cerevisiae PDE deletion strain. Recombinant TbPDE2A is specific for cAMP, with a K(m) of approximately 2 micrometer. It is entirely resistant to the nonselective PDE inhibitor 3-isobutyl-1-methylxanthine, but it is sensitive to trequinsin, dipyridamole, sildenafil, and ethaverine with IC(50) values of 5.4, 5.9, 9.4, and 14.2 micrometer, respectively. All four compounds inhibit proliferation of bloodstream form trypanosomes in culture, indicating that TbPDE2A is an essential enzyme.

Injury induced expression of TGF-beta 1 mRNA is enhanced by exogenously applied TGF-beta S

We have analysed and compared, by in situ hybridisation, the effects of exogenously applied TGF-beta s on expression of endogenous TGF-beta mRNAs in partial thickness thermal wounds in old and young mice. Although injury induced the expression of TGF-beta 1 mRNA in the epidermis and dermis at the wound margins, expression of TGF-beta 2- or TGF-beta 3-mRNA was not detected. Biopsies taken 24 hours following injury revealed a focally clustered distribution of TGF-beta 1 hybridisation signals in the dermis, the number of positive cells and expression levels being reduced in old mice. Topical application of all three TGF-beta isoforms enhanced TGF-beta 1 mRNA expression in the dermis of old and young mice. In biopsies taken three days following injury, TGF-beta 1 hybridisation signals were most prominent in the regenerating epidermis although at this timepoint differences in expression levels between treated and non-treated animals were less pronounced.

Treatment of alcohol withdrawal: tiapride and carbamazepine versus clomethiazole. A pilot study

In Germany, clomethiazole (CLO) and benzodiazepines are predominantly used as therapeutic agents in the treatment of the alcohol withdrawal syndrome (AWS). These agents have disadvantages such as sedation, risk of respiratory insufficiency, and cardiovascular complications as well as addictive potential. Alternatively, it could be demonstrated that both tiapride (TIA) and carbamazepine (CBZ) are efficient in the treatment of AWS with less toxicity. However, they seem to be less effective in AWS than CLO as single agents. But no systematic comparison of the combination of TIA and CBZ against an established therapeutic standard can be found in the literature. Therefore, we compared the combination of TIA and CBZ with CLO in two open exploratory studies with matched samples. Outcome parameters were heart rate, blood pressure, complications, withdrawal symptoms (CIWA-Ar scale), and general clinical state (CGI scale). A retrospective evaluation of medical records (30 TIA+CBZ, 30 CLO) was followed by an open prospective study (40 TIA+CBZ, 40 CLO). Both studies revealed similar efficacy in terms of psychopathologic and vegetative symptoms. Vegetative recovery seems to be faster with TIA+CBZ. Results of this exploratory study have to be confirmed by a controlled double-blind study with severity of AWS as an experimental factor.