Present trends in the pathogenesis, diagnosis and therapy of vasovagal syncope

Vasovagal syncope is the most frequent cause of syncopal conditions. In its pathogenesis autonomic nervous, neurohumoral, cerebrovascular and other mechanisms participate. The gold standard in the diagnosis of vasovagal syncope is in recent years the head up tilt test. In treatment pharmacotherapy, cardiac pacing or their combination can be used.     

Eco-Friendly Natural Clay: Montmorillonite Modified with Nickel or Ruthenium as an Effective Catalyst in Gamma-Valerolactone Synthesis

Catalysis Letters - Ni/Ru metals supported on cheap and available support montmorillonite K10 were used for the selective hydrogenation of levulinic acid to γ-valerolactone. Different loadings...     

Changes in thrombocyte aggregation in primary hypothyroidism

The authors examined the thrombocyte aggregation in 10 controls and 17 patients with the diagnosis of primary hypothyroidism before and after 2 months substitution treatment with levothyroxine. They recorded a significantly reduced intensity of the aggregation response in untreated patients as compared with controls after adrenaline (p < 0.01), ADP (p < 0.01) but not after ristocetin. Impaired thrombocyte aggregation was observed in 11 of 17 patients, i.e. in 65%. After treatment the thrombocytopathy improved in 7 of 11 patients (63%), in four it persisted. Except one female patient the thrombocytopathy improved in all patients with manifest hypothyroidism. In patients with the latent form of hypothyroidism probably an independent coincidence of elevated TSH levels and impaired thrombocyte function was involved. The authors did not detect any cases of acquired von Willebrand's disease. In the conclusion the authors mention that impaired thrombocyte aggregation is a frequent phenomenon after thyroxine treatment. It may be of clinical significance when combined with other changes of haemostasis or in conjunction with the use of some drugs.     

The Groningen Activity Restriction Scale (GARS) in the evaluation of severity of rheumatoid arthritis]

The antiviral effect of amantadine (1-aminoadamantane) was tested in vitro as well as in vivo. Treatment of persistently Borna disease virus (BDV)-infected cell lines of different origin and for various length of time did not result in a general reduction of virus titer or clearance of virus from infected cells. In vivo, rats were treated with amantadine by daily oral application or by use of osmotic pumps, and in both cases treatment was started before infection. Neither route of application of the drug had any influence on the time of onset of disease, on antiviral antibody titers, on virus titer in the brain, on the severity of the inflammatory reaction in the brain, or on the severity of neurological symptoms. These experiments, although revealing negative results and obtained using a virus from a natural case of Borna disease grown after isolation in vitro for a long period of time, should caution from the general use of amantadine as a curative agent against BDV infection as has been implicated recently [Bode et al. (1997) Lancet 349:178-179].     

Side Products Formation in the Synthesis of Diazabicyclo[2.2.2]octane on Zeolite ZSM‐5

A research investigation into the synthesis of 1, 4‐diazabicyclo[2.2.2]octane from ethylendiamine over zeolite ZSM‐5 was carried out. A number of side products such as alkylpyrazines, alkylpiperazines and alkyl‐1, 4‐diazabicyclo[2.2.2.]octanes were identified in the reaction mixture. A chemical mechanism based on elimination, condensation, cracking and proton transfer reactions was proposed for the formation of these compounds.     

Vapor–Liquid Equilibrium for Binary Mixtures of 1,4-Diazabicyclo[2.2.2]octane with Ethylenediamine,Ethanolamine, and Ethylene Glycol

Vapor–liquid equilibria of mixtures of 1,4-diazabicyclo[2.2.2]octane with ethylenediamine, ethanolamine, and ethylene glycol were studied. Ideal behavior in the ethylenediamine and 1,4-diazabicyclo[2.2.2]octane mixture was observed. Ethanolamine and 1,4-diazabicyclo[2.2.2]octane form an azeotrope with a minimum boiling point whereas ethylene glycol and 1,4-diazabicyclo[2.2.2]octane form an azeotrope with a maximum boiling point. Non-ideal behavior of the mixtures was described by the NRTL equation, and the corresponding constants were calculated.