A Potent Mimetic of the Siglec-8 Ligand 6’-Sulfo-Sialyl Lewisx

Siglecs are members of the immunoglobulin gene family containing sialic acid binding N-terminal domains. Among them, Siglec-8 is expressed on various cell types of the immune system such as eosinophils, mast cells and weakly on basophils. Cross-linking of Siglec-8 with monoclonal antibodies triggers apoptosis in eosinophils and inhibits degranulation of mast cells, making Siglec-8 a promising target for the treatment of eosinophil- and mast cell-associated diseases such as asthma. The tetrasaccharide 6’-sulfo-sialyl Lewis^x has been identified as a specific Siglec-8 ligand in glycan array screening. Here, we describe an extended study enlightening the pharmacophores of 6’-sulfo-sialyl Lewis^x and the successful development of a high-affinity mimetic. Retaining the neuraminic acid core, the introduction of a carbocyclic mimetic of the Gal moiety and a sulfonamide substituent in the 9-position gave a 20-fold improved binding affinity. Finally, the residence time, which usually is the Achilles tendon of carbohydrate/lectin interactions, could be improved.     

Topical laryngo-tracheal anesthesia and intraocular pressure in anesthesia for ophthalmic surgery

OBJECTIVE: The reflex response to orotracheal intubation provokes an increase of arterial pressure accompanied by an increase of chorioides volume and a consequent ocular hypertone. There are several methods to reduce the reflex response due to intubation. One of the most effective is topical anaesthesia of larynx and trachea. Experiments were directed to evaluate the efficacy of topical anaesthesia to reduce the intraocular hypertone due to orotracheal intubation. DESIGN: A prospective randomized mask study was conduct on patients undergoing ophthalmologic (anterior segment) surgery at the Eye Clinic of Florence University. METHODS: Intraocular pressure was measured by a Goldman tonometer at four times: T0 = basal, T1 = 2' minutes after induction of general anaesthesia, T2 = 2' minutes after laryngoscopy, T3 = 2' minutes after orotracheal intubation. At the same moments, systolic blood pressure, heart rate, rate pressure pro duct were measured. Patients were randomly divided in two groups: Group L (n = 10) in which was evaluated the efficacy of laryngotracheal topical spray of lidocaine 4% (2 ml) and Group F (n = 10) in which saline was used instead of anesthetic. The filling of the LTA kit (Abbott) was made by a person not involved in the experiments. DATA ANALYSIS: Student's t test for unpaired data. RESULTS: Topical anaesthesia reduces the increase of intraocular pressure, hypertension and rate pressure product due to intubation. The intraocular pressure reduces to 13% less than basal value in Group L and increase to 50% more than basal value in Group F. CONCLUSION: The topical anaesthesia of larynx and trachea is effective to reduce the intraocular hypertension due to the reflex response evoked by orotracheal intubation.     

Coal-oil mixture from a synthetic oil obtained by hydroliquefaction of a South African coal

A coal-oil mixture (COM) was prepared from a South African coal and a synthetic oil derived from the same coal by hydroliquefaction. The settling and rheological properties of this mixture were compared with those of a mixture of the same coal with fuel oil. The synthetic oil mixture showed greater settling stability, comparable with that of a commercial COM containing additives. The increased stability may be related to polar compounds present in the oil and on the coal surface.     

Technological strategies to improve photostability of a sunscreen agent

Due to the reduction of the ozone layer, there is an increasing need of effective UV protection systems with minimized side-effects. Trans-2-ethylhexyl- p -methoxycinnamate ( trans -EHMC) represents one of the most widely used sunscreen compound. Several studies demonstrated that trans -EHMC is unstable following UV irradiation both in solution and in emulsion formulations. Moreover, various reports of photocontact sensitization induced by trans -EHMC have appeared in the literature. Consequently, in order to ensure adequate efficacy and safety for this sunscreen agent, there is a need for new carrier systems to enhance trans -EHMC photostability. In the present study the photostability of the filter in different formulation types (emulsion–gel, gel and emulsion) with various ingredients is evaluated. In addition, nanoparticles based on poly- D , L -lactide-co-glycolide (PLGA) as carrier for trans -EHMC are investigated. The influence of nanoparticle matrix on the photochemical stability of the sunscreen agent is also presented. The results obtained demonstrated that PLGA nanoparticles are effective in reducing the light-induced degradation of the sunscreen agent. Moreover, the choice of formulation type and the excipients used play an important role in order to obtain a stable cosmetic product containing trans -EHMC.     

From information to probability: An axiomatic approach—Inference is information processing

We define the very rich language of composed conditionals on a three‐valued logic and use this language as the communication tool between man and machine. Communication takes place for three reasons: knowledge acquisition, query, and response. Learning, thinking, and answering questions are of a pure information theoretical nature. The pivot of this knowledge processing concept is the amount of information (bit) we receive if a conditional becomes true. We follow an axiomatic approach to information theory rather than the classical probabilistic approach of Shannon; information comes first, and then comes probability. In the light of this philosophy, query and response experience new interpretations. Both, acquisition and response are realized by maximizing entropy and minimizing relative entropy, respectively. The iterative solution of these mathematical optimization problems gives new insights into the adaptation of prior knowledge to new information. Our expert system shell SPIRIT supports this kind of knowledge processing, which will be established by suitable examples. © 2003 Wiley Periodicals, Inc.     

Numerical analysis of propagation and impedance matching in 2Dphotonic crystal waveguides with finite length

A novel way of approaching wave propagation in two-dimensional (2-D) photonic crystal guides with finite length is presented. It is shown that the main propagation features can be captured by borrowing simple concepts of propagation in transmission lines and combining them with other concepts taken from the theory of periodic structures     

An anomalous vena cava inferior with azygos continuation: a clinical case report

We report a case of azygos continuation of inferior vena cava. The diagnosis is confirmed by C.T. scans. We also report possible diagnosis among other pathologies which substain similar radiographic pictures bat which are connected with silent clinic evolution.