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AIM: To study overall drug resistance genes (resistome) in the human gut microbiome and the changes in these genes during COVID-19 in-hospital therapy. MATERIALS AND METHODS: A single-center retrospective cohort study was conducted. Only cases with laboratory-confirmed SARS-CoV-2 RNA using polymerase chain reaction in oro-/nasopharyngeal swab samples were subject to analysis. The patients with a documented history of or current comorbidities of the hepatobiliary system, malignant neoplasms of any localization, systemic and autoimmune diseases, as well as pregnant women were excluded. Feces were collected from all study subjects for subsequent metagenomic sequencing. The final cohort was divided into two groups depending on the disease severity: mild (group 1) and severe (group 2). Within group 2, five subgroups were formed, depending on the use of antibacterial drugs (ABD): group 2A (receiving ABD), group 2AC (receiving ABD before hospitalization), group 2AD (receiving ABD during hospitalization), group 2AE (receiving ABD during and before hospitalization), group 2B (not receiving ABD). RESULTS: The median number of antibiotic resistance (ABR) genes (cumulative at all time points) was significantly higher in the group of patients treated with ABD: 81.0 (95% CI 73.8-84.5) vs. 51.0 (95% CI 31.1-68.4). In the group of patients treated with ABD (2A), the average number of multidrug resistance genes (efflux systems) was significantly higher than in controls (group 2B): 47.0 (95% CI 46.0-51.2) vs. 21.5 (95% CI 7.0-43.9). Patients with severe coronavirus infection tended to have a higher median number of ABR genes but without statistical significance. Patients in the severe COVID-19 group who did not receive ABD before and during hospitalization also had more resistance genes than the patients in the comparison group. CONCLUSION: This study demonstrated that fewer ABR genes were identified in the group with a milder disease than in the group with a more severe disease associated with more ABR genes, with the following five being the most common: SULI, MSRC, ACRE, EFMA, SAT.
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COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , Feminino , Masculino , Estudos Retrospectivos , Pessoa de Meia-Idade , SARS-CoV-2/genética , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/genética , Adulto , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Resistência Microbiana a Medicamentos/genética , Índice de Gravidade de Doença , Farmacorresistência Bacteriana/genética , Tratamento Farmacológico da COVID-19RESUMO
The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.
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Data accumulated in the last years indicate that certain visual and acoustic interventions are of geroprotective potential. Among them are bright light, white noise, and also rhythmic sensory stimulation (flickering light, binaural rhythms), etc. It should be noted that visual and acoustic interventions are simple in use, safe and practically do not have adverse side effects and do not need special medical control. Here, we review the studies on using the visual and acoustic interventions for improving mental health with regard to the advanced age and age-related pathology. We also discuss possible mechanisms of their therapeutic action and points for the future investigations.
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Acústica , Saúde MentalRESUMO
AIM: To evaluate the efficacy of Saccharomyces boulardii (S. boulardii) CNCM I-745 probiotic drug in preventing and treating diarrhea in hospitalized patients with COVID-19. MATERIALS AND METHODS: A prospective comparative study was conducted in two parallel groups. The study included males and females aged 18 to 60 with the following diagnosis confirmed by polymerase chain reaction: U07.2 Coronavirus infection COVID-19, caused by SARS-CoV-2 virus (grade 1-3 pneumonia according to CT scan). All patients received antibiotic therapy. The patients were subdivided into two equal groups (n=60) depending on the administration of S. boulardii CNCM I-745 probiotic drug in addition to standard treatment. The probiotic was prescribed by the attending physician; the dose was 2 capsules per day (500 mg/day) 30 min before the meal for 10 days. All patients were monitored for main clinical, laboratory, and instrumental parameters during the study. In addition, the symptom of diarrhea (stool with a frequency of more than 3 times a day of type 6 and 7 according to the Bristol stool scale), including its frequency, duration, and the number of bowel movements of loose stool per day were precisely evaluated in both groups. RESULTS: In the overall patient pool, diarrhea was reported in 21.7% of in-patients during the observation period (95% confidence interval [CI] 14.2-29.1) with a mean duration of 4.6154 days (95% CI 3.7910-5.4398). The incidence of diarrhea in group 1 was 13.3% (95% CI 4.5-22.2), and in group 2, it was 30.0% (95% CI 18.1-41.9). Relative risk showed that the use of the S. boulardii CNCM I-745 probiotic drug leads to a significant reduction in the risk of diarrhea in hospitalized patients with COVID-19 infection receiving antibiotic therapy (odds ratio [OR] 0.3590, 95% CI 0.1421-0.9069; p=0.0303). In group 1, the duration of diarrhea was 3.1250 days (95% CI 2.5892-3.6608) versus 5.2778 days (95% CI 4.2290-6.3265) in group 2, p=0.0112. The mean daily frequency of loose stools in patients with diarrhea in group 1 was 3.2500 (95% CI 2.6588-3.8412) versus 4.3889 (95% CI 3.7252-5.0525) in group 2, p=0.0272. The secondary endpoint, duration of hospital stay, was also significantly shorter in group 1 patients - 11.6833 days (95% CI 11.2042-12.1625) versus 12.7333 days (95% CI 12.1357-13.3309) in group 2, p=0.0120. CONCLUSION: The present prospective comparative study demonstrated that adding S. boulardii CNCM I-745 probiotic drug into the standard treatment regimen of patients with new coronavirus infection COVID-19 receiving antibiotic therapy helps reduce the incidence of diarrhea and its severity during hospitalization, as well as the duration of hospital stay.
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COVID-19 , Probióticos , Saccharomyces boulardii , Masculino , Feminino , Humanos , Preparações Farmacêuticas , Estudos Prospectivos , SARS-CoV-2 , Diarreia/epidemiologia , Diarreia/etiologia , Diarreia/prevenção & controle , Probióticos/uso terapêutico , Antibacterianos/uso terapêuticoRESUMO
AIM: To identify features of the taxonomic composition of the oropharyngeal microbiota of COVID-19 patients with different disease severity. MATERIALS AND METHODS: The study group included 156 patients hospitalized with confirmed diagnosis of COVID-19 in the clinical medical center of Yevdokimov Moscow State University of Medicine and Dentistry between April and June 2021. There were 77 patients with mild pneumonia according to CT (CT1) and 79 patients with moderate to severe pneumonia (CT2 and CT3). Oropharyngeal swabs were taken when the patient was admitted to the hospital. Total DNA was isolated from the samples, then V3V4 regions of the 16s rRNA gene were amplified, followed by sequencing using Illumina HiSeq 2500 platform. DADA2 algorithm was used to obtain amplicon sequence variants (ASV). RESULTS: When comparing the microbial composition of the oropharynx of the patients with different forms of pneumonia, we have identified ASVs associated with the development of both mild and severe pneumonia outside hospital treatment. Based on the results obtained, ASVs associated with a lower degree of lung damage belong predominantly to the class of Gram-negative Firmicutes (Negativicutes), to various classes of Proteobacteria, as well as to the order Fusobacteria. In turn, ASVs associated with a greater degree of lung damage belong predominantly to Gram-positive classes of Firmicutes Bacilli and Clostridia. While being hospitalized, patients with severe pneumonia demonstrated negative disease dynamics during treatment significantly more often. CONCLUSION: We have observed differences in the taxonomic composition of the oropharyngeal microbiota in patients with different forms of pneumonia developed outside hospital treatment against COVID-19. Such differences might be due to the presumed barrier function of the oropharyngeal microbiota, which reduces the risk of virus titer increase.
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COVID-19 , Microbiota , Humanos , RNA Ribossômico 16S/genética , Orofaringe/microbiologia , PulmãoRESUMO
AIM: Assessment of the prevalence and prognostic value of gastroenterological manifestations in patients with COVID-19. MATERIALS AND METHODS: A single-center retrospective cohort study was carried out. Only cases with laboratory confirmed detection of SARS-CoV-2 virus RNA using polymerase chain reaction in oro-/nasopharyngeal smear samples were subject to analysis. Patients with documented (according to anamnestic data and/or according to examination data during hospitalization) organic pathology of the gastrointestinal tract (GIT) and/or hepatobiliary system, malignant neoplasms of any localization, as well as pregnant patients were excluded from the general register of retrospective data. The final cohort was divided into two groups depending on the presence of gastrointestinal symptoms: COVID-19 with gastrointestinal symptoms (cases) and COVID-19 without gastrointestinal symptoms (control). RESULTS: The final sample consisted of 3764 patients, including 2108 (56%) women and 1656 (44%) men. The average age of the subjects included in the analysis was 58.0 years (95% confidence interval CI 48.663.0). In the study cohort, gastroenterological manifestations (alone or in combination) were recorded in 885 (23.51%) patients. Calculation of the odds ratio (OR) of unfavorable and lethal outcomes between the analyzed groups showed that the presence of gastroenterological symptoms significantly increases the chances of lethal outcome in a cohort of elderly and senile patients (OR 1.6817, 95% CI 1.03352.7364; p=0.0364), determines a higher risk of hospitalization or transfer to the intensive care unit (OR 1.2959, 95% CI 1.05471.5922; p=0.0136), development of acute respiratory distress syndrome (OR 1.5952, 95% CI 1.31641.9329; p0.0001), as well as the need for mechanical ventilation (OR 1.2849, 95% CI 1.0771.5329; p=0.0054). CONCLUSION: The present study has demonstrated that gastroenterological symptoms are detected in about one in four patients infected with the SARS-CoV-2 virus and multiply the risk of adverse and life-threatening complications of COVID-19.
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COVID-19 , Masculino , Humanos , Feminino , Idoso , Pessoa de Meia-Idade , COVID-19/diagnóstico , COVID-19/epidemiologia , SARS-CoV-2 , Estudos Retrospectivos , Prevalência , Prognóstico , Universidades , Trato Gastrointestinal , RNARESUMO
AIM: Determine the primary antibiotic resistance of Helicobacter pylori (H. pylori) strains isolated from patients living in the European part of the Russian Federation. MATERIALS AND METHODS: As part of a clinical laboratory study, from 2015 to 2018, 27 gastrobiopsy samples obtained from H. pylori-infected patients were analyzed. H. pylori infection was verified using a rapid urease test or a 13C-urea breath test. The values of the minimum inhibitory concentration (MIC) of antibiotics were determined by the diffusion method using E-test strips (BioMerieux, France) according to the recommendations of the manufacturer. The sensitivity of the isolates was determined for 6 antibacterial drugs (amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, rifampicin). RESULTS: According to the data obtained, resistance to amoxicillin was 0%, clarithromycin 11.1%, metronidazole 59.3%, levofloxacin 3.7%, tetracycline 0%, and rifampicin 14.8%. Dual resistance to clarithromycin and metronidazole was recorded in two isolates (7.4%). CONCLUSION: Thus, the first results of the evaluation of H. pylori antibiotic resistance in the European part of the Russian Federation indicate a low resistance of the microorganism to clarithromycin and quite high to metronidazole.
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Infecções por Helicobacter , Helicobacter pylori , Amoxicilina , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Claritromicina/farmacologia , Farmacorresistência Bacteriana , Resistência Microbiana a Medicamentos , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/epidemiologia , Humanos , Levofloxacino , Testes de Sensibilidade Microbiana , Federação RussaRESUMO
Transcranial ultrasound stimulation (TUS) holds great potential as a tool to alter neural circuits non-invasively in both animals and humans. In contrast to established non-invasive brain stimulation methods, ultrasonic waves can be focused on both cortical and deep brain targets with the unprecedented spatial resolution as small as a few cubic millimeters. This focusing allows exclusive targeting of small subcortical structures, previously accessible only by invasive deep brain stimulation devices. The neuromodulatory effects of TUS are likely derived from the kinetic interaction of the ultrasound waves with neuronal membranes and their constitutive mechanosensitive ion channels, to produce short term and long-lasting changes in neuronal excitability and spontaneous firing rate. After decades of mechanistic and safety investigation, the technique has finally come of age, and an increasing number of human TUS studies are expected. Given its excellent compatibility with non-invasive brain mapping techniques, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI), as well as neuromodulatory techniques, such as transcranial magnetic stimulation (TMS), systemic TUS effects can readily be assessed in both basic and clinical research. In this review, we present the fundamentals of TUS for a broader audience. We provide up-to-date information on the physical and neurophysiological mechanisms of TUS, available readouts for its neural and behavioral effects, insights gained from animal models and human studies, potential clinical applications, and safety considerations. Moreover, we discuss the indirect effects of TUS on the nervous system through peripheral co-stimulation and how these confounding factors can be mitigated by proper control conditions.
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Encéfalo/fisiologia , Potenciais Evocados , Plasticidade Neuronal , Ultrassonografia de Intervenção/métodos , Animais , Encéfalo/citologia , Humanos , Neurônios/metabolismo , Neurônios/fisiologia , Neurônios/efeitos da radiação , Ondas UltrassônicasRESUMO
The strong coupling constant α s is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of α s ( m Z ) at the Z-boson mass m Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be α s ( m Z ) = 0.1157 ( 20 ) exp ( 29 ) th . Complementary, α s ( m Z ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value α s ( m Z ) = 0.1142 ( 28 ) tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.
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Human plasma contains a considerable concentration of low molecular weight substances that inhibit, in a dose-dependent manner, both high-affinity imipramine receptor binding and serotonin uptake in platelets. Incubation of plasma with alumina was used to extract and to partly characterize these imipramine-like inhibitors. The human plasma extract inhibited imipramine binding and serotonin uptake with median inhibitory concentration (IC50) of 0.18 +/- 0.1 and 0.36 +/- 0.15 mg/ml, respectively. Imipramine-like activity of the extract was markedly degraded by carboxypeptidase B and leucine aminopeptidase, but was resistant to neurominidase and phospholipases A2, C, and D. The elution profile of the extract after gel chromatography on Bio-Gel P-2 showed two major peaks of serotonin uptake and imipramine binding inhibition and three additional peaks of serotonin uptake inhibitory activity that did not have a significant effect on imipramine binding. The possible mechanism of pharmacological action of the imipramine-like inhibitors and their relation to development of affective illnesses remain to be clarified.
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Plaquetas/metabolismo , Proteínas de Transporte , Imipramina/antagonistas & inibidores , Receptores de Droga , Receptores de Neurotransmissores/metabolismo , Antagonistas da Serotonina/sangue , Cromatografia em Gel , Transtorno Depressivo/sangue , Humanos , Imipramina/sangue , Cinética , Serotonina/sangueRESUMO
Functional groups essential for high- and low-affinity [3H]imipramine (IMI) binding were determined by the method of chemical modification. The high-affinity recognition sites contained cysteine and lysine amino acid residues, but not aspartic or glutamic acid residues. The low-affinity recognition sites contained only cysteine residues. Moreover, probably only part of these sites contained these residues. The arginine, tyrosine and histidine residues are not likely to be functionally important for the [3H]IMI binding process. Analysis of the structure-function interaction of drug molecules reveals that, for all substances with high displacement ability, there is a conformation in which they can react with high-affinity IMI recognition sites. Data obtained allowed us to construct a tentative structure model of the high-affinity recognition IMI binding site.
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Plaquetas/química , Proteínas de Transporte , Membrana Celular/química , Receptores de Droga , Receptores de Neurotransmissores/química , Aminoácidos/análise , Aminoácidos/química , Antidepressivos Tricíclicos/farmacologia , Plaquetas/metabolismo , Membrana Celular/metabolismo , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Cinética , Modelos Estruturais , Psicotrópicos/farmacologia , Receptores de Neurotransmissores/metabolismo , Relação Estrutura-Atividade , Compostos de Sulfidrila/química , Reagentes de Sulfidrila/farmacologiaRESUMO
We have confirmed the presence of two different classes of [3H]imipramine ([3H]IMI) binding sites on human platelets: high-affinity (Kd = 0.52 nM, Bmax = 1670 fmol/mg protein) and low-affinity (Kd = 101 nM, Bmax = 8,000 fmol/mg protein) binding sites. The high-affinity component of [3H]IMI binding can also be obtained separately as the difference between specific [3H]IMI binding in Na-containing and Li-containing incubation buffer. The low-affinity component can be obtained as the difference between [3H]IMI binding in 50 mM Tris-HCl, 5 mM KCl, 120 mM LiCl, (pH 7.5) in the absence and presence of 0.1 mM IMI. The chemical modification of SH groups was performed with Ellman's reagent (10 mM, 40 min at 23 degrees C). The high-affinity component of the binding was totally inhibited while the low-affinity component only decreased by 39%. No decrease in [3H]IMI specific binding was observed when the modification of SH groups was carried out in the presence of 1 microM IMI. The inhibition of high- and low-affinity [3H]IMI binding was reversible since it was completely restored by incubation of modified membranes with 1,4-dithioerythritol (DTE). The reduction of SS groups by DTE (10 mM, 1 h at 23 degrees C) in the intact membrane preparation produced an increase in total number of binding sites of the high-affinity component of [3H]IMI binding by 50%.
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Plaquetas/metabolismo , Proteínas de Transporte , Imipramina/metabolismo , Receptores de Droga , Receptores de Neurotransmissores/metabolismo , Enxofre/metabolismo , Adulto , Ligação Competitiva , Proteínas Sanguíneas/metabolismo , Membrana Celular/metabolismo , Ácido Ditionitrobenzoico/farmacocinética , Humanos , Técnicas In Vitro , MasculinoRESUMO
A new approach to constructing the profiles of protein families is proposed, which uses only structural similarity of amino acid residues. We derived multiple alignments of protein sequences from 3D superpositions of the protein structures and constructed protein family profiles using structural molecular MNA descriptors. MNA (Multilevel Neighborhoods of Atoms) descriptors were developed earlier and are successfully applied for predicting the biological activity in drug-like compounds. In our approach, each aligned position was described by a set of MNA descriptors calculated for each amino acid residue in the alignment column. In this study, we constructed MNA profiles for trypsin, subtilase, and cytochrome P450 protein families and scanned SWISSPROT with some fragments of these profiles. We also calculated the Independence Accuracy of Prediction for each profile fragment. It was shown that the approach developed could be applied to predict protein function.
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Proteínas/química , Sequência de Aminoácidos , Animais , Humanos , Dados de Sequência Molecular , Conformação Proteica , Homologia de Sequência de AminoácidosRESUMO
The drug antibodies were radioimmunologically detected in 58.3% of depressive patients treated with Imipramine. A group of patients with the antibodies permanently present either proved fully resistant or showed a minor effect. A group with antibodies arising just at the start of the treatment displayed either complete remission or substantial improvement. Antibodies were not found in patients exhibiting full recovery or considerable improvement.
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Anticorpos/análise , Transtorno Depressivo/imunologia , Imipramina/imunologia , Adulto , Transtorno Depressivo/tratamento farmacológico , Resistência a Medicamentos , Humanos , Radioimunoensaio , Fatores de TempoRESUMO
The paper deals with the analysis of data available in literature and those of the authors' own investigations concerning the structure, properties and regulation of acetyl-CoA-carboxylase. Nicotinic acid is one of the factors regulating the enzyme activity in the animal liver. It inhibits the acetyl-CoA-carboxylase activity through two mechanisms--allosteric regulation and covalent modification. A comparative characteristic of the studied enzyme preparations has shown that administration of nicotinic acid to animals leads to phosphorylation of acetyl-CoA-carboxylase which affects its structure. A complex with homogenic acetyl-CoA-carboxylase is found to contain cAMP-independent and cAMP-dependent protein kinase. The phosphorylation is controlled by citrate competing with nicotinic acid for the coupling sites.
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Acetil-CoA Carboxilase/metabolismo , Ligases/metabolismo , Fígado/enzimologia , Acetilcoenzima A/metabolismo , Acetil-CoA Carboxilase/antagonistas & inibidores , Acetil-CoA Carboxilase/isolamento & purificação , Regulação Alostérica , Animais , Galinhas , Citratos/metabolismo , Ácidos Graxos/biossíntese , Lipídeos/biossíntese , Fígado/metabolismo , Niacina/farmacologia , Fosforilação , Especificidade por SubstratoRESUMO
Protein kinase strong-associated with acetyl-CoA-carboxylase is isolated from the liver of chicken and 300-fold purified with alimentary intensification of lipogenesis and under the effect of nicotinic acid against this background. The obtained enzymes are studied comparatively. It is found that their preparations are phosphorylated with different rate, have two pH optima and differ in the sensitivity to cAMP and to thermostable protein inhibitor. The hydrophobic chromatography was used to separate components of the acetyl-CoA-carboxylase-protein kinase complex and to reveal in the chicken liver cAMP-dependent and cAMP-independent protein kinases highly specific to acetyl-CoA-carboxylase and strongly bound with it.
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Lipídeos/biossíntese , Fígado/enzimologia , Niacina/farmacologia , Proteínas Quinases/metabolismo , Acetil-CoA Carboxilase/metabolismo , Animais , Galinhas , Cromatografia DEAE-Celulose , Cromatografia em Gel , AMP Cíclico/metabolismo , Eletroforese em Gel de Poliacrilamida , Cinética , Inibidores de Proteínas Quinases , Proteínas Quinases/isolamento & purificação , Especificidade por SubstratoRESUMO
Sites of cAMP and ATP binding which regulate acetyl-CoA-carboxylase phosphorylation rate characterized under conditions of lipogenesis intensification and nicotinic acid action on this enzyme 1500 fold purified and containing proteinkinase activity. The acetyl-CoA-carboxylase preparation contains only one type of the cAMP binding sites which possess higher capacity under the action of nicotinic acid in vivo. A decrease of the cAMP binding under the conditions of lipogenesis intensification is induced by diminution of the cAMP binding site capacity without changing the binding constant value. It is established that [gamma-32P]ATP is incorporated in enzyme with Km value equal for two states under study. It this case the [gamma-32P]ATP incorporation rate is much higher for acetyl-CoA-carboxylase produced from chicken liver under the action of nicotinic acid.
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Acetil-CoA Carboxilase/metabolismo , Ligases/metabolismo , Lipídeos/biossíntese , Fígado/enzimologia , Niacina/farmacologia , Acetil-CoA Carboxilase/antagonistas & inibidores , Animais , Sítios de Ligação , Galinhas , AMP Cíclico/metabolismo , Cinética , Fígado/metabolismo , FosforilaçãoRESUMO
Comparative investigations in reception of NAD, benzodiazepines and GABA by synaptic membranes under a single and multiple administration of phenazepam and nicotinamide to animals as well as after withdrawal of long-term administration of these drugs have been carried out. The both drugs activate GABA-inhibiting system of synaptic membranes. Both the sections of specific binding of benzodiazepines and of NAD take part in realization of "cancellation" syndrome. Chronic administration of phenazepam and nicotinamide results in the change of coupling in GABA-benzodiazepine receptor complex. After the withdrawal of chronic administration of nicotinamide the function of GABA-benzodiazepine receptor complex is normalized more quickly.
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Ansiolíticos/efeitos adversos , Benzodiazepinas , Benzodiazepinonas/efeitos adversos , NAD/metabolismo , Niacinamida/efeitos adversos , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA/efeitos dos fármacos , Receptores Nicotínicos/efeitos dos fármacos , Síndrome de Abstinência a Substâncias , Animais , Masculino , Ratos , Receptores de GABA/metabolismo , Receptores de GABA-A/metabolismo , Receptores Nicotínicos/metabolismo , Membranas Sinápticas/efeitos dos fármacos , Membranas Sinápticas/metabolismoRESUMO
Acetyl-CoA-carboxylase is isolated and purified to a homogeneous state from the chicken liver with alimentary lipogenesis stimulation. Under the action of nicotinic acid in vivo the specific enzyme activity is shown to decrease considerably followed by some variations in its properties. According to the results obtained during ultracentrifugation and PAAG electrophoresis nicotinic acid causes partial enzyme deaggregation with simultaneous increase of its phosphorylation. The latter is accompanied by a rise in the content of phosphate labile to alkali on acetyl-CoA-carboxylase subunits. Nicotinic acid in vivo has practically no effect on acetyl-CoA-carboxylase synthesis and decay rate. Its inhibiting action is induced by stimulation of enzyme phosphorylation.
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Acetil-CoA Carboxilase/metabolismo , Ligases/metabolismo , Lipídeos/biossíntese , Fígado/enzimologia , Niacina/farmacologia , Acetil-CoA Carboxilase/isolamento & purificação , Animais , Galinhas , FosforilaçãoRESUMO
Nicotinic acid in vivo affects the citrate demand for acetyl-CoA-carboxylase activation in the chicken liver under conditions of alimentary lipogenesis stimulation. Stoichiometry of the citrate binding with the dissociation constant of the enzyme-allosteric activator complex is determined under experimental conditions. Endogenic phosphorylation of acetyl-CoA-carboxylase completely correlates with its inactivation and depends on the citrate level. cAMP is established to have an activating effect on phosphorylation of acetyl-CoA-carboxylase of test animals.