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1.
Eye (Lond) ; 31(6): 890-898, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28211882

RESUMO

PurposeThe purpose of this study is to evaluate an early switch to aflibecept in eyes with neovascular age-related macular degeneration (nvAMD) showing partial or lack of response for initial therapy with bevacizumab.MethodsThe Aflibercept as a Second Line Therapy for Neovascular Age Related Macular Degeneration in Israel (ASLI) was a prospective, multicenter, single-arm clinical trial. Eyes with nvAMD having incomplete response to 3-9 prior bevacizumab injections were recruited. Three monthly intravitreal aflibercept (2 mg) injections were administered, followed by two bi-monthly injections and a final examination at week 28. An optional injection was allowed at week 20.ResultsForty-seven eyes of 46 patients (mean±SD age 76±8 years) were recruited. The mean number of prior bevacizumab injections was 5.5±2.9. The mean visual acuity improved from 60.3±10 ETDRS letters at baseline to 63.1±15 letters at week 28 (P=0.02, paired t-test). The central subfield thickness (CST) reduced from 409±127 micron at baseline to 330±110 microns at week 4 (P=0.0002; paired t-test), and 277±70 microns at week 28 (P=0.00002; paired t-test). Twenty-two eyes had three to five prior bevacizumab injections (mean 5.1±0.7), and 25 eyes had six to nine prior injections (7.32±1.2). Both groups had reduced CST from baseline to week 28 (P=0.0004 and P=0.0007; paired t-test, respectively). Thirty-five (75%) eyes required the optional additional aflibercept injection at week 20.ConclusionsThe ASLI study demonstrated improved BCVA and reduced CST following an early switch to aflibercept therapy in eyes with prior incomplete response to initial therapy with three to nine bevacizumab injections.


Assuntos
Receptores de Fatores de Crescimento do Endotélio Vascular/administração & dosagem , Proteínas Recombinantes de Fusão/administração & dosagem , Acuidade Visual , Degeneração Macular Exsudativa/tratamento farmacológico , Idoso , Inibidores da Angiogênese/administração & dosagem , Bevacizumab/administração & dosagem , Relação Dose-Resposta a Droga , Esquema de Medicação , Substituição de Medicamentos , Feminino , Seguimentos , Humanos , Injeções Intravítreas , Israel/epidemiologia , Macula Lutea/patologia , Masculino , Prevalência , Estudos Prospectivos , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Tomografia de Coerência Óptica , Resultado do Tratamento , Degeneração Macular Exsudativa/diagnóstico , Degeneração Macular Exsudativa/epidemiologia
2.
Adv Gerontol ; 27(4): 678-82, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25946843

RESUMO

The article presents the analysis of physical and psychological health components characterizing the quality of life of lonely and living alone people aged 60 years and older in various settings of medical and social care provision. A significant portion of respondents is satisfied with the medical and social care, but the physical and psychological health components of the elderly manifest the low quality of life, irrespective of the settings of medical and social care provision.


Assuntos
Envelhecimento , Avaliação Geriátrica/métodos , Serviços de Saúde para Idosos/normas , Satisfação Pessoal , Qualidade de Vida , Apoio Social , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Envelhecimento/psicologia , Serviços de Saúde para Idosos/estatística & dados numéricos , Humanos , Pessoa de Meia-Idade , Qualidade da Assistência à Saúde , Federação Russa , Inquéritos e Questionários
3.
Philos Trans A Math Phys Eng Sci ; 371(1991): 20110479, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23588046

RESUMO

Simple chaotic systems are useful tools for testing methods for use in numerical weather simulations owing to their transparency and computational cheapness. The Lorenz system was used here; the full system was defined as 'truth', whereas a truncated version was used as a testbed for parametrization schemes. Several stochastic parametrization schemes were investigated, including additive and multiplicative noise. The forecasts were started from perfect initial conditions, eliminating initial condition uncertainty. The stochastically generated ensembles were compared with perturbed parameter ensembles and deterministic schemes. The stochastic parametrizations showed an improvement in weather and climate forecasting skill over deterministic parametrizations. Including a temporal autocorrelation resulted in a significant improvement over white noise, challenging the standard idea that a parametrization should only represent sub-gridscale variability. The skill of the ensemble at representing model uncertainty was tested; the stochastic ensembles gave better estimates of model uncertainty than the perturbed parameter ensembles. The forecasting skill of the parametrizations was found to be linked to their ability to reproduce the climatology of the full model. This is important in a seamless prediction system, allowing the reliability of short-term forecasts to provide a quantitative constraint on the accuracy of climate predictions from the same system.

4.
Scand J Infect Dis ; 41(6-7): 445-9, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19452350

RESUMO

Pasteurella multocida is the commonest organism infecting pet bites. Anecdotal reports tend to overemphasize dramatic outcomes. We aimed to study a large database of P. multocida infections. This retrospective survey of P. multocida infections in Israeli hospitals refers to the y 2000-2005. Clinical microbiologists were contacted by email and asked to perform a back-search of their hospital's records for isolates of P. multocida. The charts of patients growing P. multocida were abstracted into a structured questionnaire. 77 cases were identified in 12 hospitals, yielding an annual incidence of 0.19/100,000. The mean age was 49.2+/-26.5 y and the mortality rate was 2.6%. Those who died were >65 y of age, had diabetes mellitus or cirrhosis and were bacteraemic. One-third of the cases occurred in people aged > or =65 y. Cats caused most of these infections (54%). Surgery for debridement was common (53.7%), but no-one required amputation; a second- and third-look operation was necessary for these patients. Bacteraemia was found in 32.5% of patients and was significantly more common among those aged >60 y (p =0.044). Hospitalized patients with P. multocida have a favourable prognosis, apart from elderly and bacteraemic patients with comorbidities. Surgery and reoperations may be required in about half of the patients.


Assuntos
Infecções por Pasteurella/epidemiologia , Pasteurella multocida/isolamento & purificação , Adolescente , Adulto , Idoso , Antibacterianos/uso terapêutico , Bacteriemia/tratamento farmacológico , Bacteriemia/epidemiologia , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Infecções por Pasteurella/diagnóstico , Infecções por Pasteurella/tratamento farmacológico , Estudos Retrospectivos , Inquéritos e Questionários
5.
Phys Rev E Stat Nonlin Soft Matter Phys ; 78(2 Pt 2): 026203, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18850917

RESUMO

It is possible to compare results for the classical tests for embeddings of chaotic data with the results of a recently proposed test. The classical tests, which depend on real numbers (fractal dimensions, Lyapunov exponents) averaged over an attractor, are compared with a topological test that depends on integers. The comparison can only be done for mappings into three dimensions. We find that the classical tests fail to predict when a mapping is an embedding and when it is not. We point out the reasons for this failure, which are not restricted to three dimensions.

6.
Prikl Biokhim Mikrobiol ; 44(6): 653-62, 2008.
Artigo em Russo | MEDLINE | ID: mdl-19145972

RESUMO

We optimized the conditions for isolation of extracellular catalases from Penicillium piceum F-648 and P. piceum A3 by means of volume chromatography with cadmium hydroxide gel. Our study showed that 55-57 mg wet gel are sufficient for the maximum sorption of catalase from 1 ml of culture fluid. This gel was formed in 1 ml 70 mM Cd(NO3)2 after addition of NaOH (Cd(NO3)2/NaOH molar ratio 1:2.2). The eluting solution contained 50 mM NaH2PO4 (pH 7.0), 5.0 mM dithiothreitol, and 0.3% sodium cholate and was potent in desorbing catalase from the gel. Subsequent ultrafiltration of the eluate on the membrane with a retention limit of 50 kDa allowed us to concentrate and purify the sample from low-molecular-weight protein impurities. NH4Cl (1.0 M) containing 0.3% sodium cholate was used to wash the sample from low-molecular-weight aromatic metabolites. Purified catalases included 33-34% antiparallel beta-structures and 9% alpha-spirals. Under optimal conditions in the medium of 10 mM phosphate buffered saline (pH 7.0) at 30 degrees C, catalases from P. piceum F-648 were characterized by the following parameters: K(M), 158.8 mM; catalytic constant, 2.83 x 10(6) s(-1); enzyme inactivation rate constant in H2O2 decomposition, 3.5 x 10(-2) s(-1); and constant of the interaction between catalase complex I and second molecule of H2O2, 1.8 x 10(7) M(-1) s(-1).


Assuntos
Compostos de Cádmio/química , Catalase/química , Catalase/isolamento & purificação , Proteínas Fúngicas/química , Proteínas Fúngicas/isolamento & purificação , Hidróxidos/química , Penicillium/enzimologia , Compostos de Cádmio/síntese química , Cromatografia Líquida/métodos , Géis/síntese química , Géis/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Hidróxidos/síntese química , Estrutura Secundária de Proteína/fisiologia
7.
Phys Rev E Stat Nonlin Soft Matter Phys ; 75(4 Pt 2): 046201, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17500972

RESUMO

We study an autonomous four-dimensional dynamical system used to model certain geophysical processes. This system generates a chaotic attractor that is strongly contracting, with four Lyapunov exponents lambdai that satisfy lambda1+lambda2+lambda3<0 , so the Lyapunov dimension is DL=2+|lambda3|/lambda1<3 in the range of coupling parameter values studied. As a result, it should be possible to find three-dimensional spaces in which the attractors can be embedded so that topological analyses can be carried out to determine which stretching and squeezing mechanisms generate chaotic behavior. We study mappings into R3 to determine which can be used as embeddings to reconstruct the dynamics. We find dramatically different behavior in the two simplest mappings: projections from R4 to R3 . In one case the one-parameter family of attractors studied remains topologically unchanged for all coupling parameter values. In the other case, during an intermediate range of parameter values the projection undergoes self-intersections, while the embedded attractors at the two ends of this range are topologically mirror images of each other.

8.
J Acoust Soc Am ; 119(1): 549-58, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16454308

RESUMO

In this paper we develop an improved surrogate data test to show experimental evidence, for all the simple vowels of U.S. English, for both male and female speakers, that Gaussian linear prediction analysis, a ubiquitous technique in current speech technologies, cannot be used to extract all the dynamical structure of real speech time series. The test provides robust evidence undermining the validity of these linear techniques, supporting the assumptions of either dynamical nonlinearity and/or non-Gaussianity common to more recent, complex, efforts at dynamical modeling speech time series. However, an additional finding is that the classical assumptions cannot be ruled out entirely, and plausible evidence is given to explain the success of the linear Gaussian theory as a weak approximation to the true, nonlinear/non-Gaussian dynamics. This supports the use of appropriate hybrid linear/nonlinear/non-Gaussian modeling. With a calibrated calculation of statistic and particular choice of experimental protocol, some of the known systematic problems of the method of surrogate data testing are circumvented to obtain results to support the conclusions to a high level of significance.


Assuntos
Acústica da Fala , Voz/fisiologia , Feminino , Análise de Fourier , Humanos , Masculino , Computação Matemática , Dinâmica não Linear , Distribuição Normal , Espectrografia do Som , Fatores de Tempo
9.
Probl Tuberk Bolezn Legk ; (8): 39-42, 2005.
Artigo em Russo | MEDLINE | ID: mdl-16209019

RESUMO

The results of examination of 84 patients with tuberculosis of the central nervous system were used to make comparative clinical and laboratory studies. They revealed that lymphocytosis detected in the cerebrospinal fluid (CF), particularly the prevalence of lymphocytes (more than 50%), and decreased levels of chlorides in the cytogram were of value in the comprehensive diagnosis of tuberculous meningitis. The detection of CF Mycobacterium tuberculosis (MBT) (applying the whole currently available set of methods) is an absolute criterion for the diagnosis of tuberculous meningitis (however, with, unfortunately, few number positive results). The detection of mycobacterial DNA, antigens, and tuberculosis antibodies is an impotent component of a diagnostic complex for tuberculous meningitis. The determination of cytosis, protein, glucose, chlorides, lymphocytic subpopulations, soluble gamma-interferon mediators, mycobacteria, DNA, MBT antigens, and tuberculosis antibodies in SF is essential in treating tuberculous meningitis.


Assuntos
Tuberculose Meníngea/diagnóstico , Adolescente , Adulto , Anticorpos Antibacterianos/análise , Antígenos CD/análise , Líquido Cefalorraquidiano/microbiologia , DNA Bacteriano/análise , Feminino , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase , Fatores de Tempo , Tuberculose Meníngea/líquido cefalorraquidiano , Tuberculose Meníngea/microbiologia
10.
Probl Tuberk Bolezn Legk ; (12): 19-22, 2005.
Artigo em Russo | MEDLINE | ID: mdl-16496756

RESUMO

The authors share their experience in using a KFP-FC-RP digital fluorograph for mass fluorographic studies in a mobile fluorographic laboratory (on the basis of a ZIL-5301 EO automobile with a module body and an APCF-01 (ProScan-2000) fluograph made by ZAO "RENTGENPROM"). Studies were performed at the enterprises of Moscow and the Moscow Region. How the work of the mobile laboratory is organized is described. Since the able-bodied population was chiefly surveyed, the efficiency of the work can be considered rather high. The experience has shown that the use of a mobile fluorographic laboratory for mass examinations at the enterprises by a health care facility is much more effective and profitable than that of a permanent laboratory.


Assuntos
Unidades Móveis de Saúde , Fotofluorografia/instrumentação , Intensificação de Imagem Radiográfica , Tuberculose Pulmonar/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Desenho de Equipamento , Feminino , Humanos , Masculino , Radiografia Pulmonar de Massa/instrumentação , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
11.
Prikl Biokhim Mikrobiol ; 40(5): 505-12, 2004.
Artigo em Russo | MEDLINE | ID: mdl-15553779

RESUMO

The abilities of various sorbents to adsorb catalase (CAT; EC 1.11.1.6) from filtered culture liquid (FCL) of the fungus Penicillium piceum F-648 were compared. Potassium phosphate, hydroxyapatite (HAP), and coprecipitated sorbents containing calcium phosphate and magnesium hydroxide adsorbed extracellular CAT more efficiently than aluminum oxide, aluminum phosphate, or quartz sand. The enzyme was isolated from FCL of Penicillium piceum with the use of HAP and a binary coprecipitated sorbent, Ca3(PO4)2 + Mg(OH)2, 1:1 (CM). The CAT(CM) sample contained the least amount of protein admixture. Its spectra had absorption maximums at 279.6, 406.8 (Soret band), 540, 585, 636, and 703 nm and negative molar ellipticity minimums at 207 and 210-214 nm. The kinetic indices of the samples (KM, Vmax:KM, and specific activity) were intricately dependent on protein concentration in the reaction mixture. In dilute solutions, the KM and specific activities of CAT(CM) and CAT(HAP) equaled 667 and 137 mM; 300.9 x 10(4) and 30.0 x 10(4) U/mg protein, respectively. The effective velocity constants of inactivation of CAT(HAP), CAT(CM), and FCL in the reaction of H2O2 decomposition increased dramatically after dilution of samples. In the infinitely dilute solution, they were 4.30 x 10(-2), 6.46 x 10(-2), and 1.12 x 10(-2), respectively.


Assuntos
Catalase/isolamento & purificação , Penicillium/enzimologia , Adsorção , Fosfatos de Cálcio , Catalase/química , Precipitação Química , Meios de Cultivo Condicionados , Durapatita , Hidróxido de Magnésio , Fosfatos , Compostos de Potássio , Análise Espectral
12.
Neuroscience ; 118(2): 463-76, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12699782

RESUMO

We examined astrocytic basic fibroblast growth factor immunoreactivity (FGF-2-IR) and tyrosine hydroxylase immunoreactivity (TH-IR) in the cell-body region of midbrain dopaminergic neurons after unilateral infusions of the neurotoxin 6-hydroxydopamine into the medial forebrain bundle in male and female rats. In addition, to determine whether neonatal exposure to gonadal hormones has consequences on the expression of astrocytic FGF-2 and cell loss in response to injury in adulthood, we studied the effects of these lesions in adult male and female rats that had been exposed or not to testosterone in the neonatal period. In both males and females there was a progressive loss of TH-expressing cells that peaked 5 weeks after the lesions. Females showed less loss of TH-expressing cells than males, but this effect was not estrogen dependent. Lesions led to an increase in expression of astrocytic FGF-2 that was greater in males than in females. Finally, it was found that, regardless of genetic sex, rats exposed to testosterone neonatally showed greater astrocytic FGF-2 expression after lesions than those not exposed, and that among those not exposed to testosterone, estrogen treatment had a modest protective effect. Analysis of behavior and striatal dopamine content showed that the percent of striatal dopamine depletion 14 days after the lesion correlated with the amount of behavioral asymmetry displayed by animals on all tests conducted after lesioning. In groups killed 2 and 5 weeks after the lesion, the amount of behavioral asymmetry correlated with the percent loss of TH-IR cells and with the percent increase in FGF-2-IR cells in the midbrain. These relationships were not evident in groups killed 3 and 7 days after the lesion, possibly because the changes in the number of FGF-2- and TH-IR cells were not fully manifested. The present findings show that hormonal events early in life can alter the response of midbrain dopamine neurons to insult and injury in adult life and suggest that the slow degeneration of these neurons may release signals triggering a sustained activation of adjacent astrocytes which, in turn, may lead to induction of astrocytic FGF-2.


Assuntos
Astrócitos/metabolismo , Estradiol/análogos & derivados , Fator 2 de Crescimento de Fibroblastos/metabolismo , Hormônios/farmacologia , Mesencéfalo/metabolismo , Neurônios/metabolismo , Caracteres Sexuais , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Animais Recém-Nascidos , Astrócitos/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Contagem de Células , Estradiol/farmacologia , Feminino , Lateralidade Funcional , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Masculino , Feixe Prosencefálico Mediano/lesões , Neurônios/efeitos dos fármacos , Ratos , Ratos Wistar , Testosterona/farmacologia , Fatores de Tempo , Anormalidade Torcional/induzido quimicamente , Anormalidade Torcional/fisiopatologia
13.
Prikl Biokhim Mikrobiol ; 39(1): 31-6, 2003.
Artigo em Russo | MEDLINE | ID: mdl-12625039

RESUMO

Resistance of Penicillium piceum F-648 to hydrogen peroxide under short-term and prolonged oxidative stress was studied. An increase in the activity of intracellular catalase in fungal cells after short-term exposure to hydrogen peroxide was shown. Activation of fungal cells induced by H2O2 depends on H2O2 concentration, time of exposure, and the growth phase of the fungus. Variants of P. piceum F-648 that produced two forms of extracellular catalase with different catalytic properties were obtained due to prolonged adaptation to H2O2. Catalase with low affinity for substrate was produced predominantly by the parent culture and variant 3; however, a high substrate affinity of catalase was observed in variant 5. Variant 5 of P. peniceum F-648 displayed a high catalytic activity and operational stability of catalase in the presence of phosphate ions and the concentration of substrate less than 30 mM at pH more than 7.


Assuntos
Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo , Penicillium/efeitos dos fármacos , Catalase/genética , Catalase/metabolismo , Relação Dose-Resposta a Droga , Farmacorresistência Fúngica/genética , Ativação Enzimática/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Penicillium/enzimologia , Penicillium/genética , Fosfatos/farmacologia , Fatores de Tempo
14.
Prikl Biokhim Mikrobiol ; 38(4): 374-80, 2002.
Artigo em Russo | MEDLINE | ID: mdl-12325292

RESUMO

A comparative kinetic study of extracellular catalases produced by Penicillium piceum F-648 and their variants adapted to H2O2 was performed in culture liquid filtrates. The specific activity of catalase, the maximum rate of catalase-induced H2O2 degradation (Vmax),Vmax/KM ratio, and the catalase inactivation rate constant in the enzymatic reaction (kin, s-1) were estimated in phosphate buffer (pH 7.4) at 30 degrees C. The effective constant representing the rate of catalase thermal inactivation (kin*, s-1) was determined at 45 degrees C. In all samples, the specific activity and KM for catalase were maximum at a protein concentration in culture liquid filtrates of 2.5-3.5 x 10(-4) mg/ml. The effective constants describing the rate of H2O2 degradation (k, s-1) were similar to that observed in the initial culture. These values reflected a twofold decrease in catalase activity in culture liquid filtrates. We hypothesized that culture liquid filtrates contain two isoforms of extracellular catalase characterized by different activities and affinities for H2O2. Catalases from variants 5 and 3 with high and low affinities for H2O2, respectively, had a greater operational stability than the enzyme from the initial culture. The method of adaptive selection for H2O2 can be used to obtain fungal variants producing extracellular catalases with improved properties.


Assuntos
Adaptação Fisiológica , Catalase/metabolismo , Peróxido de Hidrogênio/farmacologia , Penicillium/enzimologia , Catálise , Cinética , Penicillium/efeitos dos fármacos , Penicillium/fisiologia
15.
Mikrobiologiia ; 69(4): 494-8, 2000.
Artigo em Russo | MEDLINE | ID: mdl-11008685

RESUMO

After the mutagenesis of Penicillium funiculosum with UV light and N-nitroso-N-methylurea, 83 of 2237 grown colonies were surrounded with increased zones of glucose oxidase diffusion. Analysis of the glucose oxidase activity of selected mutant strains grown in submerged cultures allowed 18 mutant strains to be obtained whose glucose oxidase activity was 5-153% higher (in a medium with glucose) and 4-83% higher (in a medium with sucrose) than that of the parent strain. Two of these mutant strains, UV6.31 and NMU95-132, possessed high glucose oxidase activity when grown in media with glucose or sucrose and produced large amounts of mycelia. The active and morphologically stable mutant P. funiculosum NMU95-132 was chosen for further selection work.


Assuntos
Glucose Oxidase/biossíntese , Mutação , Penicillium/enzimologia , Metilnitrosoureia/farmacologia , Penicillium/efeitos dos fármacos , Penicillium/genética , Penicillium/efeitos da radiação , Raios Ultravioleta
16.
Eye (Lond) ; 12 ( Pt 1): 102-3, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9614524

RESUMO

Kimura's disease is a chronic inflammatory disease involving connective tissues. We treated a patient with bilateral periocular Kimura's disease causing eyelid deformity and exophthalmos for over 20 years. She has been operated on 23 times and biopsies were taken and studied histologically. The disease continued despite the multiple surgical excisions. The consequent exophthalmos and lid changes caused lagophthalmos that resulted in severe visual impairment due to chronic bilateral corneal exposure. Kimura's disease may have a devastating effect on visual function.


Assuntos
Hiperplasia Angiolinfoide com Eosinofilia/complicações , Exoftalmia/etiologia , Doenças Palpebrais/etiologia , Ceratite/etiologia , Hiperplasia Angiolinfoide com Eosinofilia/patologia , Hiperplasia Angiolinfoide com Eosinofilia/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Reoperação
18.
Exp Clin Psychopharmacol ; 5(2): 119-22, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9234047

RESUMO

The ability of ibogaine, injected 24 hr before amphetamine, to modify the establishment of amphetamine-induced place preference learning was assessed. A single injection of ibogaine blocked the establishment of amphetamine place preference after 1 or 2 conditioning trials, but it was less effective after 4 trials. The reduced effectiveness of ibogaine across multiple conditioning trials appears to be the result of the development of tolerance to ibogaine.


Assuntos
Anfetamina/antagonistas & inibidores , Estimulantes do Sistema Nervoso Central/antagonistas & inibidores , Condicionamento Operante/efeitos dos fármacos , Ibogaína/farmacologia , Psicotrópicos/farmacologia , Anfetamina/farmacologia , Animais , Estimulantes do Sistema Nervoso Central/farmacologia , Tolerância a Medicamentos , Masculino , Ratos , Ratos Sprague-Dawley
19.
Appl Radiat Isot ; 47(11-12): 1321-8, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9022192

RESUMO

ESR-spectrometry was used to investigate radiation-induced paramagnetic centers in enamel of mammals: carnivores (polar bear and fox), ungulates (reindeer, European bison, moose), and man. Values at half the microwave power saturation of the radiation signal, P1/2, evaluated at room temperature, was found to range from 16 to 26 mW for animals and man. A new approach to discrimination of the radiation induced signal from the total ESR spectrum of reindeer enamel is proposed. 'Dose-response' dependencies of enamel of different species mammals were measured within the dose range from 0.48 up to 10.08 Gy. Estimations of 'radiosensitivity' enamel of carnivores and ungulates showed good agreement with radiosensitivity enamel of man by ESR method.


Assuntos
Esmalte Dentário/efeitos da radiação , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Radiometria/métodos , Adulto , Idoso , Animais , Carnívoros , Esmalte Dentário/química , Relação Dose-Resposta à Radiação , Humanos , Técnicas In Vitro , Micro-Ondas , Pessoa de Meia-Idade , Tolerância a Radiação , Rena , Ruminantes
20.
Biofizika ; 41(5): 1075-81, 1996.
Artigo em Russo | MEDLINE | ID: mdl-9011188

RESUMO

The electron-spin relaxation of Escherichia coli cytoplasmic membrane strong binding Cu-centers was investigated by means of the microwave power saturation of the electronic spin resonance signal. It has been established, that copper centres in the strong binding sites of the cytoplasmic membrane E.coli may be represented in the following way: 1) isolate copper complexes with small speed of the spin-lattice relaxation; 2) isolate copper complexes with increased speed of spin-lattice relaxation by means of interaction with rapidly relaxation centres; 3) dipol-binding clasters; 4) ESR-nondetectable at T = 40 K, exchange-binding clasters, which cause increasing of the spin-lattice relaxation speed for isolate copper complexes.


Assuntos
Membrana Celular/metabolismo , Cobre/metabolismo , Escherichia coli/metabolismo , Sítios de Ligação , Cobre/química , Espectroscopia de Ressonância de Spin Eletrônica
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