Essential oils in medicine: principles of therapy

Essential oils (EOs) are extremely complex mixtures containing compounds of several different functional-group classes. A specific aromatic profile should be determined by gas-chromatography-mass detection methods, to define standards for their safety and efficacy. The chemical constituents of the essential oils, their flavour and their taste act both alone and in synergy, always determining a global psychosomatic action. The main therapeutic activities of the EOs are reported as spasmolythic, revulsive, anti-inflammatory and decongestant, immunomodulant, antimicrobial, antimycotic, expectorant, mucolythic, antioxidant, psychotrope, analgesic and acaricide. The use, posology, route of administration as well as toxicity and adverse effects are reviewed.     

New bispyridinium oximes: in vitro and in vivo evaluation of their biological efficiency in soman and tabun poisoning

Improving the efficacy of antidotal treatment of poisonings with nerve agents is still a challenge for the scientific community. This study investigated the interactions of four bispyridinium oximes with human erythrocyte acetylcholinesterase (AChE) and their effects on soman- and tabun-poisoned mice. Oximes HI-6 and TMB-4 were used for comparison. These oximes inhibited AchE with inhibitory potency (IC(50)) ranging from 0.02 to 1.0 mM. The best reactivating potency (%R) was obtained with K074, when AChE was inhibited by tabun. The protective potency (P(50)) of all oximes in human erythrocyte AChE inhibited by soman and tabun could not be determined. In tabun-poisoned mice very good antidotal efficacy was obtained with K027, K048, and K074, which makes them interesting for future investigation. The combination of HI-6 and atropine is the therapy of choice for soman poisoning.     

A wavelet-based ECG delineation algorithm for 32-bit integer online processing

Background  

Since the first well-known electrocardiogram (ECG) delineator based on Wavelet Transform (WT) presented by Li et al. in 1995, a significant research effort has been devoted to the exploitation of this promising method. Its ability to reliably delineate the major waveform components (mono- or bi-phasic P wave, QRS, and mono- or bi-phasic T wave) would make it a suitable candidate for efficient online processing of ambulatory ECG signals. Unfortunately, previous implementations of this method adopt non-linear operators such as root mean square (RMS) or floating point algebra, which are computationally demanding.     

Genetic identification of units for conservation in tomato frogs, genus Dyscophus

Dyscophus antongilii and D. guineti are two morphologically very similar microhylid frogs from Madagascar of uncertain taxonomy. D. antongilii is currently included in Appendix I of the Convention on the International Trade in Endangered Species (CITES) and its exportation is banned completely. In contrast, D. guineti does not receive any legal protection and it is regularly exported. Field data on ecology and behaviour are to a large extent lacking. Here we report on a genetic survey of D. antongilii and D. guineti using nuclear and mitochondrial DNA markers. Sequences of a fragment of 501 bp of the mitochondrial cytochrome b gene from one population of D. antongilii and two populations of D. guineti resulted in a single haplotype network, without haplotype sharing among the populations. However, haplotypes of D.␣guineti were only 1–4 mutational steps from those of D. antongilii, and did not form a clade. The analysis of eight microsatellites newly developed and standardized for D. antongilii revealed an excess of homozygotes and the absence of Hardy–Weinberg equilibrium. The microsatellite data clearly distinguished between D. antongilii and D. guineti, and fixed differences were observed at one locus. Although confirmation of the status of Dyscophus antongilii and D. guineti as separate species requires further data, our study supports the definition of these two taxa as different evolutionary significant units under the adaptive evolutionary conservation concept.     

Effect of the acclimation to high environmental temperature on the activity of hepatic glycogen phosphorylase (a+b and a), liver glycogen content and blood glucose level in rats

(1) Changes in the activity of hepatic glycogen phosphorylase a+b and a (GPh-ase a+b and a), liver glycogen content and blood glucose level during acclimation to moderate high environmental temperature (35±1 °C) were studied. (2) Experiments were carried out on adult fed Wistar rats of both sexes, previously given either short-term (1, 4 and 7 days) or long-term (14, 21, 30 and 60 days) exposure to high environmental temperature. The controls were continuously kept at room temperature (20±2 °C). (3) The results obtained showed that in the period of short-term exposure the liver glycogen content was decreased significantly (after the first and fourth days in male rats and after first day in female rats) and the GPh-ase a activity increased (after first day in male rats and after first, fourth and seventh day in female rats). Long-term exposure caused significant increased liver glycogen content (beginning from the 14th day in male rats and the 21st day in female rats) until the end of the acclimation period (60 days). The elevated activity of GPh-ase a persists after 14th day of exposure only in female rats while there are no significant changes over the rest of the acclimation period in both sexes. There were no significant changes in total GPh-ase activity during the whole period of exposure. Blood glucose level was significantly decreased throughout the whole period of acclimation to high environmental temperature, in both sexes (except in the 1 day exposed groups). (4) The increased activity of hepatic GPh-ase a and decreased glycogen content suggested that the short-term exposure to heat stimulates the glycogenolytical processes. Decreased blood glucose level, and elevated liver glycogen content (r=-0.7467 in male and r=-0.6548 in female rats) suggested that prolonged exposure to high environmental temperature stimulated glycogenogenesis, without changes in the GPh-ase activity.     

Conformational changes of beta-lactoglobulin in sodium bis(2-ethylhexyl) sulfosuccinate reverse micelles. A fluorescence and CD study.

The effect of beta-lactoglobulin encapsulation in sodium bis(2-ethylhexyl) sulfosuccinate reverse micelles on the environment of protein and on Trp was analysed at different water contents (omega0). CD data underlined the distortion of the beta-sheet and a less constrained tertiary structure as the omega0 increased, in agreement with a concomitant red shift and a decrease in the signal intensity obtained in steady-state fluorescence measurements. Fluorescence lifetimes, evaluated by biexponential analysis, were tau1 = 1.28 ns and tau2 = 3.36 ns in neutral water. In reverse micelles, decay-associated spectra indicated the occurrence of important environmental changes associated with omega0. Bimolecular fluorescence quenching by CCl4 and acrylamide was employed to analyse alterations in the accessibility of the two Trp residues in beta-lactoglobulin, induced by changes in omega0. The average bimolecular quenching constant was found not to depend on omega0, confirming the insolubility of this quencher in the aqueous interface, while increases with omega0. The drastic decrease with omega0 of kq, associated with the longest lifetime kq2(CCl4), comparatively to the increase of kq2(acrylamide), emphasizes the location of beta-lactoglobulin in the aqueous interfacial region especially at omega0> or = 10. The fact that (omega0 = 30) > kq2(acrylamide) (water) also confirms the important conformational changes of encapsulated beta-lactoglobulin.     

Synthetic prions with novel strain-specified properties

Prions are infectious proteins that possess multiple self-propagating structures. The information for strains and structural specific barriers appears to be contained exclusively in the folding of the pathological isoform, PrP^Sc. Many recent studies determined that de novo prion strains could be generated in vitro from the structural conversion of recombinant (rec) prion protein (PrP) into amyloidal structures. Our aim was to elucidate the conformational diversity of pathological recPrP amyloids and their biological activities, as well as to gain novel insights in characterizing molecular events involved in mammalian prion conversion and propagation. To this end we generated infectious materials that possess different conformational structures. Our methodology for the prion conversion of recPrP required only purified rec full-length mouse (Mo) PrP and common chemicals. Neither infected brain extracts nor amplified PrP^Sc were used. Following two different in vitro protocols recMoPrP converted to amyloid fibrils without any seeding factor. Mouse hypothalamic GT1 and neuroblastoma N2a cell lines were infected with these amyloid preparations as fast screening methodology to characterize the infectious materials. Remarkably, a large number of amyloid preparations were able to induce the conformational change of endogenous PrP^C to harbor several distinctive proteinase-resistant PrP forms. One such preparation was characterized in vivo habouring a synthetic prion with novel strain specified neuropathological and biochemical properties.     

Intralesional uridine-5′-triphosphate (UTP) treatment induced resistance to <Emphasis Type="Italic">Leishmania amazonensis</Emphasis> infection by boosting Th<Subscript>1</Subscript> immune responses and reactive oxygen species production

Leishmania amazonensis is the etiologic agent of cutaneous leishmaniasis, an immune-driven disease causing a range of clinical symptoms. Infections caused by L. amazonensis suppress the activation and function of immune cells, including macrophages, dendritic cells, and CD4⁺ T cells. In this study, we analyzed the course of infection as well as the leishmanicidal effect of intralesional UTP treatment in L. amazonensis-infected BALB/c mice. We found that UTP treatment reduced the parasitic load in both footpad and lymph node sites of infection. UTP also boosted Th1 immune responses, increasing CD4⁺ T cell recruitment and production of IFN-γ, IL-1β, IL-12, and TNF-α. In addition, the role of UTP during innate immune response against L. amazonensis was evaluated using the air pouch model. We observed that UTP augmented neutrophil chemoattraction and activated microbicidal mechanisms, including ROS production. In conclusion, our data suggested an important role for this physiological nucleotide in controlling L. amazonensis infection, and its possible use as a therapeutic agent for shifting immune responses to Th1 and increasing host resistance against L. amazonensis infection.