Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
2.
J Proteome Res ; 11(12): 6213-22, 2012 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-23121565

RESUMEN

A nano-HPLC-ESI-OrbiTrap study involving HCD and ETD spectra has been carried out to clarify the composition of the skin peptidome of brown Russian frogs Rana temporaria. This approach allowed determinantion of 76 individual peptides, increasing 3-fold the identified portion of the peptidome in comparison to that obtained earlier with FTICR MS. A search for the new bradykinin related peptides (BRPs) was carried out by reconstructing mass chromatograms based on the ion current of characteristic b- and y-ions. Several peptides were reported in the secretion of R. temporaria for the first time. The overall antibacterial activity of the skin secretion in general and of one individual peptide (Brevinin 1Tb) was determined using PMEU Spectrion (Portable Microbe Enrichment Unit) technology. The inhibitory effects of these peptides on Staphylococcus aureus and Salmonella enterica Serovar typhimutium were equal in scale to that reported for some antibiotics.


Asunto(s)
Proteínas Anfibias/metabolismo , Antibacterianos/aislamiento & purificación , Péptidos Catiónicos Antimicrobianos/metabolismo , Secreciones Corporales/metabolismo , Péptidos/análisis , Rana temporaria/metabolismo , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Antibacterianos/metabolismo , Antibacterianos/farmacología , Bradiquinina/metabolismo , Cromatografía Líquida de Alta Presión/métodos , Masculino , Espectrometría de Masas/métodos , Datos de Secuencia Molecular , Nanotecnología , Péptidos/metabolismo , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/crecimiento & desarrollo , Especificidad de la Especie , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrollo
3.
Phys Rev Lett ; 108(20): 202502, 2012 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-23003144

RESUMEN

The 0+ ground state of the 10He nucleus produced in the 3H(8He,p)10He reaction was found at about 2.1±0.2 MeV (Γ∼2 MeV) above the three-body ^{8}He+n+n breakup threshold. Angular correlations observed for ^{10}He decay products show prominent interference patterns allowing us to draw conclusions about the structure of low-energy excited states. We interpret the observed correlations as a coherent superposition of a broad 1- state having a maximum at energy 4-6 MeV and a 2+ state above 6 MeV, setting both on top of the 0+ state "tail." This anomalous level ordering indicates that the breakdown of the N=8 shell known in 12Be thus extends also to the ^{10}He system.

4.
Rapid Commun Mass Spectrom ; 25(7): 933-40, 2011 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-21416530

RESUMEN

Amphibian skin secretion is known to contain biologically active peptides. Bradykinins and related peptides (BRPs) can be found in these animals, while frogs from the genus Rana are considered to be leaders in the levels and variety of these peptides. A reasonable rationalization of this fact is that bradykinins are efficient defense compounds against predators. Forty-four various BRPs have been identified in the skin secretions of five ranid frog species (R. ridibunda, R. lessonae, R. esculenta, R. temporaria, R. arvalis) from the Zvenigorod region (Moscow district, Russia). Some of these peptides are already known, but the novel ones constitute a significant portion. An interesting group of novel peptides was isolated from R. lessonae. These are bradykinin analogues bearing a tyrosine residue in the 5th or 8th position. [Arg(0), Trp(5), Leu(8)]bradykinin and [Thr(6), Leu(8)]bradykinin that had been isolated from fish and avian species, respectively, were also detected in the frog secretion, supporting the predator defense hypothesis. Furthermore, a novel group of BRPs named 'lessonakinins' was discovered in R. lessonae and R. esculenta. All of them include the [Arg(0), Trp(5), Leu(8)]bradykinin sequence and have some structural resemblance to the precursor of this peptide cloned by Chen and coworkers recently. However, the C-terminal part of the lessonakinins does not match the sequence predicted by Chen, demonstrating possible incompleteness of information obtained by cDNA cloning.


Asunto(s)
Secreciones Corporales/química , Bradiquinina/química , Oligopéptidos/química , Ranidae/fisiología , Piel/metabolismo , Secuencia de Aminoácidos , Animales , Espectrometría de Masas , Datos de Secuencia Molecular , Federación de Rusia , Análisis de Secuencia de Proteína
5.
Rapid Commun Mass Spectrom ; 24(12): 1749-54, 2010 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-20499319

RESUMEN

Hyla arborea schelkownikowi is one of the leaf frog species inhabiting the southern territories of Russia and the former USSR. This frog species is a member of the Hylidae Rafinesque, 1815 batrachians family. The present study deals with the previously uninvestigated peptidome of the Hyla arborea schelkownikowi skin secretion. Nano-electrospray ionization Fourier transform mass spectrometry (nanoESI-FTMS) of the skin secretion, in the intact form and after acetylation, was selected as the general method of analysis. Electron-capture dissociation (ECD) and collision-induced dissociation (CID) fragmentation were both employed, while de novo sequencing was performed by manual interpretation of the MS data. The suppression of the cyclization of b-ions in the mass spectrometer by the acetylation reaction proved to be very efficient for the de novo sequencing of short peptides. Ten skin peptides were found and all of them, except for bradykinin, had not previously been reported. Six of the peptides belong to the tryptophyllins and related peptides, while three peptides are similar to the aureins.


Asunto(s)
Péptidos/análisis , Ranidae/metabolismo , Piel/química , Piel/metabolismo , Animales , Péptidos/metabolismo , Espectrometría de Masa por Ionización de Electrospray , Espectroscopía Infrarroja por Transformada de Fourier
6.
Rapid Commun Mass Spectrom ; 23(9): 1241-8, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19308951

RESUMEN

A high-performance liquid chromatography nano-electrospray ionization Fourier transform mass spectrometry (HPLC/nanoESI-FTMS) approach involving recording of collision-activated dissociation (CAD) and electron-capture dissociation (ECD) spectra of an intact sample and two its modifications after performic oxidation and reduction followed by carboxamidomethylation helps to establish peptide profiles in the crude secretion of frog species at mid-throughput level, including de novo sequencing. The proposed derivatization procedures allow increasing of the general sequence coverage in the backbone, providing complementary information and, what is more important, reveal the amino acid sequence in the cystine ring ('rana box'). Thus purely mass spectrometric efficient sequencing becomes possible for longer than usual proteolytic peptides. Seventeen peptides belonging to four known families were identified in the secretion of the European brown frog Rana arvalis inhabiting the Moscow region in Russia. Ranatuerins, considered previously a unique feature of the North American species, as well as a new melittin-related peptide, are worth special mention. The developed approach was previously successfully used for the identification of peptides in the skin secretion of the Caucasian green frog Rana ridibunda.


Asunto(s)
Proteínas Anfibias/análisis , Cromatografía Líquida de Alta Presión/métodos , Péptidos/análisis , Ranidae/fisiología , Piel/metabolismo , Espectrometría de Masa por Ionización de Electrospray/métodos , Secuencia de Aminoácidos , Proteínas Anfibias/metabolismo , Animales , Antiinfecciosos/análisis , Antiinfecciosos/metabolismo , Femenino , Masculino , Datos de Secuencia Molecular , Oxidación-Reducción , Péptidos/metabolismo , Federación de Rusia
7.
Vestn Rentgenol Radiol ; (2-3): 33-6, 2008.
Artículo en Ruso | MEDLINE | ID: mdl-21337761

RESUMEN

The new possibilities of using scattered x-ray radiation in mammology are presented by the example of obtaining the new type of a highly informative breast image, by identifying the distribution of an effective atomic number by dual-energy exposure.


Asunto(s)
Absorciometría de Fotón/métodos , Neoplasias de la Mama/diagnóstico por imagen , Mamografía/métodos , Femenino , Humanos , Dispersión de Radiación , Rayos X
8.
Eur J Mass Spectrom (Chichester) ; 13(2): 155-63, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17881782

RESUMEN

Tandem mass spectrometry sequencing, as well as Edman sequencing of peptides belonging to the Rana genus, represents a difficult task due to the presence of a disulfide bridge at the C-terminus and their rather high molecular masses (over 2000 Da). The present study throws light upon the sequence of three rather long peptides (more than 20 amino acid residues each) isolated from the skin secretion of Russian frogs, Rana ridibunda and Rana arvalis. This novel aspect involves the fact that the sequences (including two sequences established de novo) were determined exclusively by means of mass spectrometry. A combination of electron capture dissociation (ECD) and collision-induced dissociaiton (CID) data accompanied by exact mass measurements (LTQ Fourier transform ion cyclotron resonance mass spectrometer) facilitated reaching the goal. To overcome the difficulty dealing with disulphide bridges ("Rana box"), reduction of the S-S bond with dithiotreitol followed by derivatization of Cys residues with iodoacetamide was used. The sequence was determined using combined spectral data on y and b series of fragment ions. A multiple mass spectrometry (MS(3)) experiment was also used to elucidate the sequence inside the "Rana box" after cysteine derivatization. Exact mass measurements were used to differentiate between Lys and Gln residues, while characteristic losses of 29 and 43 Da (d and w fragment ions) in CID and ECD experiments allowed us to distinguish between Ile and Leu isomeric acids.


Asunto(s)
Disulfuros/química , Mapeo Peptídico/métodos , Péptidos/química , Ranidae , Piel/metabolismo , Espectrometría de Masa por Ionización de Electrospray/métodos , Secuencia de Aminoácidos , Animales , Datos de Secuencia Molecular , Péptidos/metabolismo
9.
Nature ; 447(7140): 72-5, 2007 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-17476264

RESUMEN

The heaviest elements to have been chemically characterized are seaborgium (element 106), bohrium (element 107) and hassium (element 108). All three behave according to their respective positions in groups 6, 7 and 8 of the periodic table, which arranges elements according to their outermost electrons and hence their chemical properties. However, the chemical characterization results are not trivial: relativistic effects on the electronic structure of the heaviest elements can strongly influence chemical properties. The next heavy element targeted for chemical characterization is element 112; its closed-shell electronic structure with a filled outer s orbital suggests that it may be particularly susceptible to strong deviations from the chemical property trends expected within group 12. Indeed, first experiments concluded that element 112 does not behave like its lighter homologue mercury. However, the production and identification methods used cast doubt on the validity of this result. Here we report a more reliable chemical characterization of element 112, involving the production of two atoms of (283)112 through the alpha decay of the short-lived (287)114 (which itself forms in the nuclear fusion reaction of 48Ca with 242Pu) and the adsorption of the two atoms on a gold surface. By directly comparing the adsorption characteristics of (283)112 to that of mercury and the noble gas radon, we find that element 112 is very volatile and, unlike radon, reveals a metallic interaction with the gold surface. These adsorption characteristics establish element 112 as a typical element of group 12, and its successful production unambiguously establishes the approach to the island of stability of superheavy elements through 48Ca-induced nuclear fusion reactions with actinides.

10.
Med Tekh ; (4): 21-3, 2006.
Artículo en Ruso | MEDLINE | ID: mdl-16989220

RESUMEN

The possibility of estimating the effective atomic number distribution from the ratio of the scattering and total absorption coefficients is considered. To illustrate the use of this technique in mammology, the results of measurement of microcalcinate and cholesterol distribution are discussed. It is suggested that tomographic examination of mammary gland should include detection of scattered radiation.


Asunto(s)
Enfermedades de la Mama/diagnóstico por imagen , Glándulas Mamarias Humanas , Mamografía/métodos , Calcio/análisis , Colesterol/análisis , Femenino , Humanos , Dispersión de Radiación , Rayos X
11.
Eksp Klin Gastroenterol ; (1): 78-84, 107, 2005.
Artículo en Ruso | MEDLINE | ID: mdl-15991856

RESUMEN

The study of the basal (BAP) and stimulated (SAP) acid production effect on the average daily acidity and speed of proteolysis in the stomach in vivo was conducted in 498 patients with various functional states of the stomach. It was established that the aforesaid muriatic secretion indices influence the acidity and speed of proteolysis in natural conditions of digestion only within the low and normal range of their values. In the condition of HCl hypersecretion, the dependence between the muriatic secretion and acidity and proteolytic stomach activity in vivo gets lost. This can be explained by the autoregulation effect supporting the introgastral pH optimal for pepsin activity irrespective of the intensity of the acid glands hyperplasia.


Asunto(s)
Digestión , Ácido Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Gastropatías/fisiopatología , Estómago/fisiopatología , Adolescente , Adulto , Anciano , Femenino , Histamina/farmacología , Humanos , Concentración de Iones de Hidrógeno , Masculino , Persona de Mediana Edad , Pepsina A/metabolismo , Estómago/efectos de los fármacos , Estómago/fisiología
14.
Eksp Klin Gastroenterol ; (5): 7-13, 126, 2002.
Artículo en Ruso | MEDLINE | ID: mdl-12619569

RESUMEN

In the assessment of the functional state of the stomach the interest to its secretory functioning has remained constant and in the center of attention of physiologists and clinicians during the past century. That is understandable. After all, the level of secretion of gastric juice enriched with the acid and pepsins defines numerous aspects in the functioning of this organ and its peptic, bactericidal and even evacuation functions. Moreover, under certain conditions active gastric juice can turn from a mediator in the normal peptic process into a solely pathogenetic factor and promote the development of a number of so-called acid-dependent diseases that have conventionally included stomach ulcer, reflux-esophagitis, postgastrectomy ulcers of the anastomosis and other more infrequent pathological states. A distinct positive reaction to the application of anti-acid preparations is common for all these diseases. At the same time, the role of HCI in their development remains comprehensible only in some aspects.


Asunto(s)
Estómago/fisiología , Ácido Gástrico/metabolismo , Mucosa Gástrica/metabolismo , Helicobacter pylori/aislamiento & purificación , Humanos , Concentración de Iones de Hidrógeno , Estómago/microbiología
15.
Phys Rev Lett ; 87(9): 092501, 2001 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-11531562

RESUMEN

Experimental search for (5)H using a secondary beam of (6)He has been performed. The transfer reaction (1)H((6)He,(2)He)(5)H was studied by detecting two protons emitted from the decay of (2)He. A peak consistent with a (5)H resonance at 1.7+/-0.3 MeV above the n+n+t threshold was observed, with a width of 1.9+/-0.4 MeV. The angular distribution of the (1)H((6)He,(2)He)(5)H reaction was measured as well as the energy correlation of the two protons.

16.
J Mol Evol ; 45(3): 332-6, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9302328

RESUMEN

Multiple band patterns of DNA repeats in the 20-500-nucleotide range can be detected by digesting genomic DNA with short-cutting restriction endonucleases, followed by end labeling of the restriction fragments and fractionation in nondenaturing polyacrylamide gels. We call such band patterns obtained from genomic DNA "taxonprints" (Fedorov et al. 1992). Here we show that taxonprints for the taxonomic groups studied (mammals, reptiles, fish, insects-altogether more than 50 species) have the following properties: (1) All individuals from the same species have identical taxonprints. (2) Taxonprint bands can be subdivided into those specific for a single species and those specific for groups of closely related species, genera, and even families. (3) Each restriction endonuclease produces unique band patterns; thus, five to ten restriction enzymes (about 100 bands) may be sufficient for a statistical treatment of phylogenetic relationships based on polymorphisms of restriction endinuclease sites. We demonstrate that taxonprint analysis allows one to distinguish closely related species and to establish the degree of similarity among species and among genera. These characteristics make taxonprint analysis a valuable tool for taxonomic and phylogenetic studies.


Asunto(s)
Clasificación/métodos , Endonucleasas/genética , Filogenia , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo Restrictivo/métodos , Animales , Desoxirribonucleasas de Localización Especificada Tipo II/genética , Marcadores Genéticos , Erizos/genética , Humanos , Grupos Raciales/genética , Especificidad de la Especie
18.
Ter Arkh ; 69(8): 17-9, 1997.
Artículo en Ruso | MEDLINE | ID: mdl-9381384

RESUMEN

Therapeutic and prophylactic antiarrhythmic efficacy of sotalol hydrochloride (Sotahexal, "Hexal", Germany) and its effects in intracardiac hemodynamics and ECG parameters were evaluated in 95 patients with ischemic heart disease (IHD). The highest response to the drug was observed in ventricular extrasystoles, arterial flutter and fibrillation. Acute episodes of arrhythmia are managed by bolus administration of Sotahexal [correction of Hexal]. In this case greater risk of side effects exists. It is desirable to decide on the drug dose, mode of administration on the individual basis with due consideration of the risks and dangers which could be avoided in case of adequate instrumental control.


Asunto(s)
Antagonistas Adrenérgicos beta/farmacología , Antiarrítmicos/farmacología , Isquemia Miocárdica/tratamiento farmacológico , Sotalol/farmacología , Antagonistas Adrenérgicos beta/administración & dosificación , Antagonistas Adrenérgicos beta/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Animales , Antiarrítmicos/administración & dosificación , Antiarrítmicos/efectos adversos , Arritmias Cardíacas/etiología , Arritmias Cardíacas/prevención & control , Gatos , Perros , Evaluación Preclínica de Medicamentos , Femenino , Hemodinámica/efectos de los fármacos , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/complicaciones , Isquemia Miocárdica/fisiopatología , Sotalol/administración & dosificación , Sotalol/efectos adversos , Comprimidos
19.
Klin Med (Mosk) ; 73(4): 44-6, 1995.
Artículo en Ruso | MEDLINE | ID: mdl-7474818

RESUMEN

The effectiveness of the new antiarrhythmic drug bonnecor was tried in 59 patients with ventricular arrhythmia. High antiarrhythmic activity of the drug was recorded in the course doses 150 to 250 mg/day. Bonnecor effect is dose-dependent: the number of ventricular extrasystoles reduced by 75% in 62 and 74% of the patients receiving 150 mg/day and 20 mg/day, respectively. The highest effect was achieved in high-grade ventricular extrasystole. Side effects were occasional: headache lasting 1-2 hours 40-50 min after bonnecor administration, slow atrioventricular conduction (2 cases), sleep disorders (2 cases).


Asunto(s)
Antiarrítmicos/uso terapéutico , Dibenzazepinas/uso terapéutico , Complejos Prematuros Ventriculares/tratamiento farmacológico , Adulto , Anciano , Antiarrítmicos/administración & dosificación , Antiarrítmicos/efectos adversos , Dibenzazepinas/administración & dosificación , Dibenzazepinas/efectos adversos , Electrocardiografía Ambulatoria , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complejos Prematuros Ventriculares/diagnóstico
20.
Ter Arkh ; 66(2): 45-7, 1994.
Artículo en Ruso | MEDLINE | ID: mdl-8160144

RESUMEN

In a study of 159 duodenal ulcer patients the authors studied the effect of H2-blockers, antibacterial and sucralfate monotherapy on the frequency of the ulcer healing, Helicobacter pylori (HP) infection and acid-proteolytic aggression in the body and antropyloric portion of the stomach. All the drugs were found to exhibit similar antiulcer activity. Inhibition of the acid-proteolytic aggression in the gastric body was registered only under the action of H2-blockers. Antibacterial preparations inhibited the growth of HP, but did not affect the acidity and proteolysis in the gastric body. Neither did sucralfate which also had no effect on microorganisms. All the test drugs were able to reduce antropyloric acidity, thus promoting healing of the ulcer.


Asunto(s)
Antiulcerosos/farmacología , Antiulcerosos/uso terapéutico , Adolescente , Adulto , Anciano , Evaluación de Medicamentos , Úlcera Duodenal/tratamiento farmacológico , Úlcera Duodenal/fisiopatología , Femenino , Infecciones por Helicobacter/tratamiento farmacológico , Infecciones por Helicobacter/fisiopatología , Helicobacter pylori , Humanos , Masculino , Persona de Mediana Edad , Inducción de Remisión
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA