Physics of B_c mesons

In the framework of potential models for heavy quarkonium the mass spectrum for the system ($\bar b c$) is considered. Spin-dependent splittings, taking into account a change of a constant for effective coulomb interaction between the quarks, and widths of radiative transitions between the ($\bar b c$) levels are calculated. In the framework of QCD sum rules, masses of the lightest vector $B_c^*$ and pseudoscalar $B_c$ states are estimated, scaling relation for leptonic constants of heavy quarkonia is derived, and the leptonic constant $f_{B_c}$ is evaluated. The $B_c$ decays are considered in the framework of both the potential models and the QCD sum rules, where the significance of Coulomb-like corrections is shown. The relations, following from the approximate spin symmetry for the heavy quarks in the heavy quarkonium, are analysed for the form factors of the semileptonic weak exclusive decays of $B_c$. The $B_c$ lifetime is evaluated with the account of the corrections to the spectator mechanism of the decay, because of the quark binding into the meson. The total and differential cross sections of the $B_c$ production in different interactions are calculated. The analytic expressions for the fragmentational production cross sections of $B_c$ are derived. The possibility of the practical $B_c$ search in the current and future experiments at electron-positron and hadron colliders is analysed.Comment: 81 page, latex, ihep.sty is required and attached in the end of the file after \end{document}, figures are not availabl

Open label trial of granulocyte apheresis suggests therapeutic efficacy in chronically active steroid refractory ulcerative colitis

Aim: To study the efficacy, safety, and feasibility of a granulocyte adsorptive type apheresis system for the treatment of patients with chronically active ulcerative colitis despite standard therapy. Methods: An open label multicenter study was carried out in 39 patients with active ulcerative colitis (CAI 6-8) despite continuous use of steroids (a minimum total dose of 400 mg prednisone within the last 4 wk). Patients received a total of five aphereses using a granulocyte adsorptive technique (Adacolumn\uae, Otsuka Pharmaceutical Europe, UK). Assessments at wk 6 and during follow-up until 4 mo comprised clinical (CAI) and endoscopic (EI) activity index, histology, quality of life (IBDQ), and laboratory tests. Results: Thirty-five out of thirty-nine patients were qualified for intent-to-treat analysis. After the apheresis treatment at wk 6, 13/35 (37.1%) patients achieved clinical remission and 10/35 (28.6%) patients had endoscopic remission (CAI<4, EI<4). Quality of life (IBDQ) increased significantly (24 points, P<0.01) at wk 6. Apheresis could be performed in all but one patient. Aphereses were well tolerated, only one patient experienced anemia. Conclusion: In patients with steroid refractory ulcerative colitis, five aphereses with a granulocyte/monocyte depleting filter show potential short-term efficacy. Tolerability and technical feasibility of the procedure are excellent

Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

A Search for Selectrons and Squarks at HERA

Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

Congenital epulis of the jaw: a series of five cases and review of literature

This article describes five cases of congenital epulis, a rare and benign swelling in the mouth of a newborn, which is not widely known. We present five cases: four cases presented as single pedunculated nodules of the gingiva and in one case two nodules were present. Of all, 50% were located at the maxilla. Excision was performed in four of the five cases and in one case, spontaneous regression was awaited. No recurrence was reported. The characteristic features of congenital epulis are a pedunculated, flesh-pink coloured tumour with a predominant occurrence on the anterior maxillary alveolar ridge in a female newborn. Although the aetiology is unknown, most authors suggest a mesenchymal, rather than an odontogenic, origin. Endogenous hormonal factors might influence growth prenatally. Histological findings include granular cells with eosinophilic cytoplasm and small, eccentric nuclei. Despite the fact that the lesion can be a striking sight, spontaneous regression is possible and can be awaited. Indications for non-radical excision under local anaesthesia are severe upper airway obstruction and interference with feeding technique. In conclusion, we provide clinical and histological information about congenital epulis, so that this entity will be more easily recognised and relevant information given to parent

ALIGNed on adherence: subanalysis of adherence in immune-mediated inflammatory diseases in the DACH region of the global ALIGN study.

Non-adherence to medication is a challenging problem in daily clinical practice. To assess reasons for non-adherence in patients with chronic immune-mediated inflammatory diseases (IMIDs) in a direct comparison including evaluation of treatment necessity and concerns. ALIGN was a non-interventional, multicountry, multicentre, self-administered, cross-sectional, epidemiologic survey study. Here, we investigate the German, Austrian and Swiss (DACH) cohort. Six hundred thirty-one patients with different IMIDs (rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, plaque psoriasis, Crohn's disease and ulcerative colitis) under systemic therapies were evaluated concerning adherence, beliefs of necessity and concerns towards treatment in patients with IMIDs. The DACH cohort had significantly different levels of adherence depending on the IMID (P &lt; 0.05) and the type of therapy (P &lt; 0.05). Based on the significant influence of concerns on treatment adherence (P &lt; 0.05) and the high belief of treatment necessity, patients could be classified in four attitudinal segments, which were unequally distributed throughout various IMIDs. High concerns had a significant influence on non-adherence, whereas necessity did not. Older age, female sex, TNFi mono-, conventional combination and TNFi combination therapy are positively associated with adherence. In the DACH region, patients are less concerned about medication and believe in the necessity of treatment. Therefore, we suggest adapting the communication in the various patient groups

Candidiasis caused by Candida kefyr in a neonate: Case report

<p>Abstract</p> <p>Background</p> <p>Systemic <it>Candidia </it>infections are of major concern in neonates, especially in those with risk factors such as longer use of broad spectrum antibiotics. Recent studies showed that also term babies with underlying gastrointestinal or urinary tract abnormalities are much more prone to systemic <it>Candida </it>infection. We report a very rare case of candidiasis caused by <it>Candida kefyr </it>in a term neonate.</p> <p>Case Presentation</p> <p>Renal agenesis on the left side was diagnosed antenatally and anal atresia postnatally. Moreover, a vesico-ureteral-reflux (VUR) grade V was detected by cystography. The first surgical procedure, creating a protective colostoma, was uneventful. Afterwards our patient developed urosepsis caused by <it>Enterococcus faecalis </it>and was treated with piperacillin. The child improved initially, but deteriorated again. A further urine analysis revealed <it>Candida kefyr </it>in a significant number. As antibiotic resistance data about this non-<it>albicans Candida </it>species are limited, we started liposomal amphotericin B (AMB), but later changed to fluconazole after receiving the antibiogram. Candiduria persisted and abdominal imaging showed a <it>Candida </it>pyelonephritis. Since high grade reflux was prevalent we instilled AMB into the child's bladder as a therapeutic approach. While undergoing surgery (creating a neo-rectum) a recto-vesical fistula could be shown and subsequently was resected. The child recovered completely under systemic fluconazole therapy over 3 months.</p> <p>Conclusions</p> <p>Candidiasis is still of major concern in neonates with accompanying risk factors. As clinicians are confronted with an increasing number of non-<it>albicans Candida </it>species, knowledge about these pathogens and their sensitivities is of major importance.</p

Exploiting the 2-Amino-1,3,4-thiadiazole Scaffold To Inhibit <i>Trypanosoma brucei </i>Pteridine Reductase in Support of Early-Stage Drug Discovery

Pteridine reductase-1 (PTR1) is a promising drug target for the treatment of trypanosomiasis. We investigated the potential of a previously identified class of thiadiazole inhibitors of Leishmania major PTR1 for activity against Trypanosoma brucei (Tb). We solved crystal structures of several TbPTR1-inhibitor complexes to guide the structure-based design of new thiadiazole derivatives. Subsequent synthesis and enzyme- and cell-based assays confirm new, mid-micromolar inhibitors of TbPTR1 with low toxicity. In particular, compound 4m, a biphenyl-thiadiazole-2,5-diamine with IC50 = 16 μM, was able to potentiate the antitrypanosomal activity of the dihydrofolate reductase inhibitor methotrexate (MTX) with a 4.1-fold decrease of the EC50 value. In addition, the antiparasitic activity of the combination of 4m and MTX was reversed by addition of folic acid. By adopting an efficient hit discovery platform, we demonstrate, using the 2-amino-1,3,4-thiadiazole scaffold, how a promising tool for the development of anti-T. brucei agents can be obtained

The effect of ABCA1 gene polymorphisms on ischaemic stroke risk and relationship with lipid profile

<p>Abstract</p> <p>Background</p> <p>Ischaemic stroke is a common disorder with genetic and environmental components contributing to overall risk. Atherothromboembolic abnormalities, which play a crucial role in the pathogenesis of ischaemic stroke, are often the end result of dysregulation of lipid metabolism. The ATP Binding Cassette Transporter (<it>ABCA1</it>) is a key gene involved in lipid metabolism. It encodes the cholesterol regulatory efflux protein which mediates the transfer of cellular phospholipids and cholesterol to acceptor apolipoproteins such as apolipoprotein A-I (ApoA-I). Common polymorphisms in this gene affect High Density Lipoprotein Cholesterol (HDL-C) and Apolipoprotein A-I levels and so influence the risk of atherosclerosis. This study has assessed the distribution of <it>ABCA1 </it>polymorphisms and haplotype arrangements in patients with ischaemic stroke and compared them to an appropriate control group. It also examined the relationship of these polymorphisms with serum lipid profiles in cases and controls.</p> <p>Methods</p> <p>We studied four common polymorphisms in <it>ABCA1 </it>gene: G/A-L158L, G/A-R219K, G/A-G316G and G/A-R1587K in 400 Caucasian ischaemic stroke patients and 487 controls. Dynamic Allele Specific Hybridisation (DASH) was used as the genotyping assay.</p> <p>Results</p> <p>Genotype and allele frequencies of all polymorphisms were similar in cases and controls, except for a modest difference in the <it>ABCA1 </it>R219K allele frequency (P-value = 0.05). Using the PHASE2 program, haplotype frequencies for the four loci (158, 219, 316, and 1587) were estimated in cases and controls. There was no significant difference in overall haplotypes arrangement in patients group compared to controls (p = 0.27). 2211 and 1211 haplotypes (1 = common allele, 2 = rare allele) were more frequent in cases (p = 0.05). Adjusted ORs indicated 40% and 46% excess risk of stroke for these haplotypes respectively. However, none of the adjusted ORs were statistically significant. Individuals who had R219K "22" genotype had a higher LDL level (p = 0.001).</p> <p>Conclusion</p> <p>Our study does not support a major role for the <it>ABCA1 </it>gene as a risk factor for ischaemic stroke. Some haplotypes may confer a minor amount of increased risk or protection. Polymorphisms in this gene may influence serum lipid profile.</p