RESUMEN
BACKGROUND AND PURPOSE: Methoxetamine (MXE) is a novel psychoactive substance that is emerging on the Internet and induces dissociative effects and acute toxicity. Its pharmacological effects have not yet been adequately investigated. EXPERIMENTAL APPROACH: We examined a range of behavioural effects induced by acute administration of MXE (0.5-5 mg·kg-1 ; i.p.) in rats and whether it causes rapid neuroadaptive molecular changes. KEY RESULTS: MXE (0.5-5 mg·kg-1 ) affected motor activity in a dose- and time-dependent manner, inducing hypermotility and hypomotility at low and high doses respectively. At low and intermediate doses (0.5 and 1 mg·kg-1 ), MXE induced anxious and/or obsessive-compulsive traits (marble burying test), did not significantly increase sociability (social interaction test) or induce spatial anxiety (elevated plus maze test). At a high dose (5 mg·kg-1 ), MXE induced transient analgesia (tail-flick and hot-plate test), decreased social interaction time (social interaction test) and reduced immobility time while increasing swimming activity (forced swim test), suggesting an antidepressant effect. Acute MXE administration did not affect self-grooming behaviour at any dose tested. Immunohistochemical analysis showed that behaviourally active doses of MXE (1 and 5 mg·kg-1 ) increased phosphorylation of ribosomal protein S6 in the medial prefrontal cortex and hippocampus. CONCLUSIONS AND IMPLICATIONS: MXE differentially affected motor activity, behaviour and emotional states in rats, depending on the dose tested. As reported for ketamine, phosphorylation of the ribosomal protein S6 was increased in MXE-treated animals, thus providing a 'molecular snapshot' of rapid neuroadaptive molecular changes induced by behaviourally active doses of MXE.
Asunto(s)
Encéfalo/efectos de los fármacos , Ciclohexanonas/farmacología , Ciclohexilaminas/farmacología , Drogas Ilícitas/farmacología , Psicotrópicos/farmacología , Animales , Ansiedad/inducido químicamente , Conducta Animal/efectos de los fármacos , Encéfalo/metabolismo , Emociones/efectos de los fármacos , Calor , Locomoción/efectos de los fármacos , Masculino , Conducta Obsesiva/inducido químicamente , Ratas , Ratas Sprague-Dawley , Proteínas Quinasas S6 Ribosómicas/metabolismo , Conducta SocialRESUMEN
The Sinorhizobium meliloti BacA ABC transporter protein plays an important role in its nodulating symbiosis with the legume alfalfa (Medicago sativa). The Mycobacterium tuberculosis BacA homolog was found to be important for the maintenance of chronic murine infections, yet its in vivo function is unknown. In the legume plant as well as in the mammalian host, bacteria encounter host antimicrobial peptides (AMPs). We found that the M. tuberculosis BacA protein was able to partially complement the symbiotic defect of an S. meliloti BacA-deficient mutant on alfalfa plants and to protect this mutant in vitro from the antimicrobial activity of a synthetic legume peptide, NCR247, and a recombinant human ß-defensin 2 (HBD2). This finding was also confirmed using an M. tuberculosis insertion mutant. Furthermore, M. tuberculosis BacA-mediated protection of the legume symbiont S. meliloti against legume defensins as well as HBD2 is dependent on its attached ATPase domain. In addition, we show that M. tuberculosis BacA mediates peptide uptake of the truncated bovine AMP, Bac7(1-16). This process required a functional ATPase domain. We therefore suggest that M. tuberculosis BacA is important for the transport of peptides across the cytoplasmic membrane and is part of a complete ABC transporter. Hence, BacA-mediated protection against host AMPs might be important for the maintenance of latent infections.
Asunto(s)
Proteínas Bacterianas/metabolismo , Prueba de Complementación Genética , Proteínas de Transporte de Membrana/deficiencia , Proteínas de Transporte de Membrana/metabolismo , Mycobacterium tuberculosis/genética , Sinorhizobium meliloti/fisiología , Simbiosis , Antiinfecciosos/farmacología , Proteínas Bacterianas/genética , Medicago sativa/microbiología , Medicago sativa/fisiología , Proteínas de Transporte de Membrana/genética , Sinorhizobium meliloti/efectos de los fármacos , Sinorhizobium meliloti/genética , beta-Defensinas/farmacologíaRESUMEN
BACKGROUND: Amifostine (WR-2721, delivered as Ethyol) is a phosphorylated aminothiol compound clinically used in addition to cis-platinum to reduce the toxic side effects of therapeutic treatment on normal cells without reducing their efficacy on tumour cells. Its mechanism of action is attributed to the free radical scavenging properties of its active dephosphorylated metabolite WR-1065. However, amifostine has also been described as a potent hypoxia-mimetic compound and as a strong p53 inducer; both effects are known to potently modulate vascular endothelial growth factor (VEGF-A) expression. The angiogenic properties of this drug have not been clearly defined. METHODS: Cancer cell lines and endothelial cells were used in culture and treated with Amifostine in order to study (i) the expression of angiogenesis related genes and proteins and (ii) the effects of the drug on VEGF-A induced in vitro angiogenesis. RESULTS: We demonstrated that the treatment of several human cancer cell lines with therapeutical doses of WR-1065 led to a strong induction of different VEGF-A mRNA isoforms independently of HIF-1alpha. VEGF-A induction by WR-1065 depends on the activation of the eIF2alpha/ATF4 pathway. This up-regulation of VEGF-A mRNA was accompanied by an increased secretion of VEGF-A proteins fully active in stimulating vascular endothelial cells (EC). Nevertheless, direct treatment of EC with amifostine impaired their ability to respond to exogenous VEGF-A, an effect that correlated to the down-regulation of VEGFR-2 expression, to the reduction in cell surface binding of VEGF-A and to the decreased phosphorylation of the downstream p42/44 kinases. CONCLUSIONS: Taken together, our results indicate that amifostine treatment modulates tumour angiogenesis by two apparently opposite mechanisms - the increased VEGF-A expression by tumour cells and the inhibition of EC capacity to respond to VEGF-A stimulation.
Asunto(s)
Amifostina/farmacología , Moduladores de la Angiogénesis/farmacología , Depuradores de Radicales Libres/farmacología , Expresión Génica/efectos de los fármacos , Activación Transcripcional/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/biosíntesis , Factor A de Crecimiento Endotelial Vascular/metabolismo , Línea Celular , Células Cultivadas , Humanos , Receptor 2 de Factores de Crecimiento Endotelial Vascular/biosíntesisRESUMEN
The stereoselective synthesis of both enantiomers of trifluoro frontalin (-)-(1S,5R)- and (+)-(1R,5S)-8, as well as of diastereomeric monofluoro frontalines (-)-(1R,2R,5R)-18 and (-)-(1R,2S,5R)-20, analogues of the bioactive component of the aggregation pheromone of the Scolytidae insect family, has been accomplished starting from (-)-(1R)- and (+)-(1S)-menthyl (S)-toluene-4-sulfinate as a source of chirality and methyl trifluoroacetate or fluoroacetate, respectively, as sources of fluorine. The C-1 stereocenters were installed via stereoselective epoxidation of beta-sulfinyl ketones 2 and 13 with diazomethane. The bicyclic core was obtained by totally stereocontrolled and chemoselective tandem Wacker oxidation/intramolecular ketalization of the intermediate unsatured sulfinyl diols 5, 15, and 19. Axially fluorinated (-)-20 elicited a strong electroantennographic response in laboratory tests on females of Dendroctonus micans, whereas equatorially fluorinated (-)-18 and the trifluoroanalogue (-)-8 showed modest responses. Field trials using (-)-20 were not indicative owing to the locally scarce population of D. micans, but it showed some attractiveness for other Coleoptera families.
Asunto(s)
Compuestos Bicíclicos Heterocíclicos con Puentes/síntesis química , Feromonas/antagonistas & inhibidores , Animales , Conducta Animal/efectos de los fármacos , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Escarabajos , Electrofisiología , Femenino , Flúor , Indicadores y Reactivos , Control de Insectos , Feromonas/biosíntesis , Órganos de los Sentidos , EstereoisomerismoRESUMEN
[reaction: see text]. Hydride reduction of C=N bonds stereocontrolled by intramolecular pi-stacking interactions of 1-naphthylsulfinyl and N-aryl groups, nonoxidative Pummerer rearrangement, and ring-closing metathesis are efficiently combined in a highly stereoselective entry to enantiomerically pure cyclic and acyclic fluorinated beta-amino alcohols and alpha-amino acid derivatives, respectively.
Asunto(s)
Aminoácidos/síntesis química , Flúor/química , Aminoácidos/química , Estructura Molecular , EstereoisomerismoRESUMEN
[reaction: see text] Asymmetric conjugate additions of chiral alpha-amino esters to chiral 4-CF(3) Michael-acceptors were exploited to prepare a small library of enantiomerically pure partially modified retropeptides having a psi[NHCH(CF(3))] unit as a possible mimic of the classical psi(NHCO) retropeptide unit. Yields were nearly quantitative, and the stereoselectivity, which is controlled mainly by the nitrogen nucleophile, was progressively higher with increasing the steric bulk of the alpha-amino ester side-chain R(1).
Asunto(s)
Bioquímica/métodos , Péptidos/síntesis química , Imitación Molecular , Péptidos/químicaRESUMEN
Enantiopure methyl D-alpha-trifluoromethyl-allo-threoninate 18 and L-alpha-trifluoromethylthreoninate 19 were synthesized using (R)-ethyl p-tolylsulfoxide as chiral alpha-hydroxyethyl anion equivalent. The key step was the S(N)2-type replacement of the sulfinyl auxiliary with a hydroxy group, via trifluoroacetic anhydride promoted "non-oxidative" Pummerer reaction (NOPR) of the diastereomeric intermediate beta-sulfinyl amines 14 and 15, obtained by condensation of (R)-ethyl p-tolylsulfoxide 13 with the N-Cbz imine of methyl trifluoropyruvate 12. The conclusive evidence for S(N)2-type stereoselectivity of the NOPR was achieved by X-ray diffraction of both the starting diastereomer 14 and the p-bromobenzoate 25, obtained from the threoninate 19. NMR monitoring of the NOPR performed on 15 allowed the detection of a transient intermediate, which was identified as the four membered cyclic sigma-sulfurane 27. This intermediate spontaneously rearranged (40 min, rt) into the corresponding sulfenamide 17, probably via an intramolecular displacement of the sulfinyl by a trifluoroacetoxy group, with inversion of configuration at the carbon stereocenter. The same process occurred for the diastereomeric beta-sulfinyl amine 14, but the sulfenamide 16 was formed at a very fast rate, thus precluding NMR detection of the corresponding sigma-sulfurane intermediate 26. One-pot treatment of the diastereomeric sulfenamides 16 and 17 with NaBH(4) afforded very good yields of the corresponding threoninates 18 and 19.
RESUMEN
Cystic Fibrosis (CF) is a recessive autosomic genetic disease with an incidence in mediterranean countries of about 1:3500 born alive. In Italy the considerable genetic variability makes it difficult to identify all the homozygous subjects and, consequently, to estimate the incidence of the disease in healthy carriers. The disease is evolutive and affects various systems, most of all the respiratory and gastrointestinal systems. Not many years ago, when the clinical definition of CF was first introduced, average survival did not exceed the pediatric age. Nowadays with ever advancing diagnostic and therapeutical techniques many CF patients survive until an adult age. It is therefore necessary to plan adequate health service interventions so as to satisfy as much as possible the needs of both the patients and their families. To this end data collected since 1.1.1988 by the Italian registry for CF (year of birth, sex, region of birth and residence, diagnosis procedures, results of sweat test, pancreatic insufficiency, DNA analysis, status: alive, dead, lost to follow up) of all the patients, diagnosed in the 18 Reference Centres and the 3 local Centres for CF, have proved to be extremely useful. Since the birth of the Registry on 31.12.1997, data relating to 2458 patients alive on 1.1.1988 and 1159 born during the last ten years, for a total of 3617 subjects (1756 females and 1861 males), have been recorded. As already mentioned a considerable increase in life expectancy of CF patients (from 1988 to 1990 the average age of death was 14 years, from 1994 to 1997 it was 19) and a consequent increase in the percentage of adult patients have been observed.
Asunto(s)
Fibrosis Quística/epidemiología , Sistema de Registros , Adolescente , Adulto , Distribución por Edad , Edad de Inicio , Preescolar , Fibrosis Quística/diagnóstico , Fibrosis Quística/genética , Femenino , Humanos , Lactante , Recién Nacido , Italia/epidemiología , Masculino , Factores de TiempoRESUMEN
Earlier analysis of the Italian population showed patterns of genetic differentiation that were interpreted as being the result of population settlements going back to pre-Roman times. DNA disease mutations may be a powerful tool in further testing this hypothesis since the analysis of diseased individuals can detect variants too rare to be resolved in normal individuals. We present data on the relative frequencies of 60 cystic fibrosis (CF) mutations in Italy and the geographical distribution of the 12 most frequent CF mutations screened in 3492 CF chromosomes originating in 13 Italian regions. The 12 most frequent mutations characterize about 73% of the Italian CF chromosomes. The most common mutation, delta F508, has an average frequency of 51%, followed by N1303K and G542X, both with average frequencies around 5%. Multivariate analyses show that the relative frequencies of CF mutations are heterogeneous among Italian regions, and that this heterogeneity is weakly correlated with the geographical pattern of non-DNA 'classical' genetic markers. The northern regions are well differentiated from the central-southern regions and within the former group the western and eastern regions are remarkably distinct. Moreover, Sardinia shows the presence of mutation T338I, which seems absent in any other European CF chromosome. The north-western regions of Italy, characterized by the mutation 1717-1G-->A, were under Celtic influence, while the north-east regions, characterized by the mutations R1162X, 2183AA-->G and 711 + 5G-->A, were under the influence of the Venetic culture.
Asunto(s)
Fibrosis Quística/genética , Genética de Población , Mutación , Fibrosis Quística/etnología , Análisis Factorial , Frecuencia de los Genes , Humanos , Italia , FilogeniaRESUMEN
We carried out molecular screening for mutations in the cystic fibrosis transmembrane regulator (CFTR) gene in eight children of Sardinian descent seen because of hypotonic dehydration associated with hyponatremia, hypochloremia, hypokalemia, and metabolic alkalosis; none had pulmonary or pancreatic involvement. All the patients had the T3381 mutation either in homozygosity or compound heterozygosity with another CF mutation. The T3381 mutation was not detected in patients with CF who had classic symptoms or in healthy persons of the same descent. These data suggest that the T3381 mutation is associated with a specific mild CF phenotype.
Asunto(s)
Fibrosis Quística/genética , Deshidratación/genética , Proteínas de la Membrana/genética , Mutación/genética , Niño , Preescolar , Canales de Cloruro/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística , Humanos , Hiponatremia/genética , Lactante , FenotipoAsunto(s)
Fibrosis Quística/complicaciones , Cirrosis Hepática Biliar/genética , Adolescente , Femenino , Humanos , MutaciónRESUMEN
From the period of October 1987 to January 1988, 9 samples were taken from 16 workers in company canteens situated in the Sienna area. The study of enterotoxin staphylococci strains was carried out of the pharynx, nose, skin of the face and the hands. The investigation required the use of the Staphylo-Zyme P.B.I. kit and RPLA Oxoid set. The most frequently found enterotoxins were A and D, either alone or together.