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1.
J Stroke Cerebrovasc Dis ; 33(9): 107844, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38945415

RESUMO

PURPOSE: Transient ischemic attack (TIA) is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, with clinical symptoms typically lasting less than one hour, and without evidence of acute infarction. In this type of ischemic event, there are no data about a possible cardiac injury tested with troponin. After a stroke, it is well established the cardiac involvement due to a neuro-inflammatory response (recently defined as Stroke Heart Syndrome). The aim of this study is to compare the troponin elevation after a stroke with the troponin elevation after a TIA. MATERIALS AND METHODS: This is a retrospective, single center study on 565 patients (73 TIAs, 492 stroke). We collected demographic characteristics, cardiovascular risk factors, cardiac data such as troponin, NT-proBNP, left atrial dilatation, etiology of the ischemic event (TOAST classification). RESULTS: We compare IS and TIA for each TOAST subtype. In all groups no substantial differences were found in demographic and past medical history (p > 0.05). However, the maximum troponin level reached were significantly lower in TIAs than IS (p < 0.05), except in lacunar etiology were troponin elevation was low also in IS group. We found a trend in favor to IS in the rise and fall troponin elevation over 30% in all the TOAST subgroups, but only in the cryptogenic etiology the difference was significant. About the others cardiac markers of injury, a significant higher rate of elevated NT-proBNP was found in the IS cohort. CONCLUSIONS: Troponin level after TIAs is significantly lower than after IS. Troponin elevation after an ischemic event may be more relevant in patients with higher NT-proBNP levels and older age. More studies are needed to better understand the pathophysiology of this phenomenon after an ischemic event.


Assuntos
Biomarcadores , Ataque Isquêmico Transitório , AVC Isquêmico , Troponina , Humanos , Ataque Isquêmico Transitório/sangue , Ataque Isquêmico Transitório/diagnóstico , Masculino , Feminino , Idoso , Estudos Retrospectivos , Biomarcadores/sangue , AVC Isquêmico/sangue , AVC Isquêmico/diagnóstico , Pessoa de Meia-Idade , Troponina/sangue , Idoso de 80 Anos ou mais , Regulação para Cima , Fatores de Risco , Prognóstico , Valor Preditivo dos Testes , Peptídeo Natriurético Encefálico/sangue , Medição de Risco , Fragmentos de Peptídeos/sangue
2.
Eur J Neurol ; 28(1): 269-277, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931130

RESUMO

BACKGROUND AND PURPOSE: Dimethyl fumarate (DMF) causes a mean lymphocyte count drop of approximately 30% in relapsing-remitting multiple sclerosis (RRMS) patients. The relationship between this reduction and DMF effectiveness is controversial. The objective was to investigate if the decrease in absolute lymphocyte count (ALC) from baseline during DMF treatment is associated with clinical and magnetic resonance imaging (MRI) disease activity. A secondary aim was to evaluate ALC variations over time in a real-life cohort of DMF-treated patients. METHODS: Demographic, laboratory, clinical and MRI data were collected in this observational multicentre study, conducted on RRMS patients treated with DMF for at least 6 months. Multivariate Cox models were performed to evaluate the impact of 6-month ALC drop on time to no evidence of disease activity (NEDA-3) status loss. NEDA-3 is defined as absence of clinical relapses, MRI disease activity and confirmed disability progression. RESULTS: In all, 476 patients (312 females, age at DMF start 38.4 ± 9.97 years) were analysed up to 5-year follow-up. A greater lymphocyte decrease was associated with a lower risk of NEDA-3 status loss (hazard ratio 0.87, P = 0.01). A worse outcome in patients with lower ALC drop (<11.5%), compared with higher tertiles (11.5%-40.5% and >40.5%), was observed (P = 0.008). The nadir of ALC drop (-33.6%) and 35% of grade III lymphopaenia cases occurred after 12 months of treatment. CONCLUSION: A higher lymphocyte count drop at 6 months is related to better outcomes in DMF-treated patients. A careful ALC monitoring should be pursued up to 24 months of treatment.


Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Fumarato de Dimetilo/uso terapêutico , Feminino , Humanos , Imunossupressores/uso terapêutico , Contagem de Linfócitos , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Recidiva Local de Neoplasia , Resultado do Tratamento
3.
Eur J Neurol ; 27(9): 1712-1726, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32503088

RESUMO

BACKGROUND AND PURPOSE: We systematically reviewed available evidence for reports of neurological signs and symptoms in patients with COVID-19 to identify cases with severe acute respiratory syndrome coronavirus (SARS-CoV)-2 infection or immune-mediated reaction in the nervous system. METHODS: We followed PRISMA guidelines and used the MEDLINE, EMBASE, Google Scholar, MedRxiv and ChinaXiv databases to search for articles on COVID-19 and nervous system involvement that were published from 1 January to 24 April 2020. Data on design, sample size, neurological assessment and related work-up were extracted. Biases were assessed with the Newcastle-Ottawa scale. RESULTS: We analysed 27 publications on potential neuroinvasive or parainfectious neurological complications of COVID-19. The reports focused on smell and taste (n = 5) and evaluation of neurological symptoms and signs in cohorts (n = 5). There were cases of Guillain-Barré syndrome/Miller-Fisher syndrome/cranial neuropathy (seven cases), meningitis/encephalitis (nine cases) and various other conditions (five cases). The number of patients with examination of cerebrospinal fluid and, in particular, SARS-CoV-2 polymerase chain reaction was negligible. Two had a positive SARS-CoV-2 polymerase chain reaction examination of cerebrospinal fluid specimen. Study of potential parenchymal involvement with magnetic resonance imaging was rare. Only four reports received a rating of the highest quality standards. CONCLUSIONS: This systematic review failed to establish comprehensive insights into nervous system manifestations of COVID-19 beyond immune-mediated complications in the aftermath of respiratory symptoms. The authors therefore provide guidance for more careful clinical, diagnostic and epidemiological studies to characterize the manifestations and burden of neurological disease caused by SARS-CoV-2 on behalf of the Infectious Disease Panel of the European Academy of Neurology.


Assuntos
COVID-19/complicações , Doenças do Sistema Nervoso/virologia , Humanos , Imageamento por Ressonância Magnética
4.
Sleep Med ; 56: 90-97, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30803830

RESUMO

Sleep-related disorders have been reported to have a higher prevalence in multiple sclerosis (MS) than in the general population. They are often undervalued for the presence of more severe physical problems and the occurrence at night, without a direct observation in common clinical practice, but if not recognized and treated they can negatively affect the quality of life causing daytime drowsiness and worsening fatigue. Sleep related disorders most commonly reported in MS are as follows: insomnia, sleep-related breathing disorders (SRBD), restless legs syndrome (RLS) and periodic limb movement disorders (PLMD). Secondary narcolepsy, REM sleep behavior disorder (RBD) and propriospinal myoclonus have been also described in some case reports or series. The purpose of this review is to correlate the more common sleep disturbances in MS patients to the involvement of specific brain regions, analyzing their relationship with MRI findings. While insomnia is usually secondary to other disabling symptoms such as nocturia or pain, SRBD, RLS, narcolepsy, RBD and propriospinal myoclonus in MS patients can be the consequence of an injury of specific central nervous system (CNS) areas. Lesions in the pontine tegmentum and the dorsal medulla have been associated with SRBD, spinal cord lesions or atrophy with RLS, bilateral lesions in the lateral hypothalamus with narcolepsy-like symptoms, lesions in the dorsal pontine tegmentum with RBD and intramedullary demyelinating plaques in spinal cord with propriospinal myoclonus. MS specialists and general neurologists should be aware of these comorbidities since neuroimaging, which is routinely performed in MS, could provide helpful clinical indications on patients with secondary sleep-related disorders and to categorize symptomatic patients who need to underdo more in-depth sleep studies.


Assuntos
Tronco Encefálico/patologia , Comorbidade , Esclerose Múltipla/epidemiologia , Esclerose Múltipla/patologia , Síndromes da Apneia do Sono/epidemiologia , Transtornos do Sono-Vigília/epidemiologia , Medula Espinal/patologia , Tronco Encefálico/diagnóstico por imagem , Humanos , Esclerose Múltipla/diagnóstico por imagem , Transtornos do Sono-Vigília/patologia , Medula Espinal/diagnóstico por imagem
5.
Mult Scler Relat Disord ; 18: 170-172, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29141803

RESUMO

Nail loss might represent a new, reversible, adverse event associated with teriflunomide treatment. It shares close analogies with hair loss and thinning, known adverse events of teriflunomide. MS specialists should be aware of this possibility and evaluate treatment discontinuation.


Assuntos
Crotonatos/efeitos adversos , Fatores Imunológicos/efeitos adversos , Doenças da Unha/induzido quimicamente , Toluidinas/efeitos adversos , Crotonatos/uso terapêutico , Feminino , Humanos , Hidroxibutiratos , Fatores Imunológicos/uso terapêutico , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Unhas/efeitos dos fármacos , Nitrilas , Toluidinas/uso terapêutico
6.
Eur J Clin Microbiol Infect Dis ; 32(9): 1183-92, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23584672

RESUMO

We evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) Biotyper as a tool for the identification of anaerobic bacteria compared with 500 base-pair (bp) 16S ribosomal ribonucleic acid (rRNA) gene sequencing analysis, which is considered to be the "gold standard" method. A total of 484 anaerobic bacteria were retrieved from the clinical specimens of 318 pediatric patients. Molecular identification resulted in 18 genera and 51 species. The most prevalent genus was Clostridium (76.85 %), with 70 % C. difficile isolates. The concordance and sensitivity determined by MALDI-TOF MS for C. difficile, the most prevalent species isolated, was 94.08 %, whereas the specificity was 100 %. For the other anaerobes, the sensitivity and specificity were 94.07 % and 81.82 %, respectively, with a concordance of 93.15 %. Low performance was observed for Propionibacterium acnes and Fusobacterium nucleatum, for which a dedicated pretreatment procedure should likely be set up. MALDI-TOF MS was shown to be a valid alternative for the fast and reliable identification of the most clinically relevant anaerobic bacteria; moreover, it is less time-consuming, the cost for reagents is minimized, and it does not require dedicated personnel.


Assuntos
Bactérias Anaeróbias/classificação , Infecções Bacterianas/diagnóstico , Técnicas de Tipagem Bacteriana/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Bactérias Anaeróbias/isolamento & purificação , Bacteroides/isolamento & purificação , Sequência de Bases , Criança , Clostridium/classificação , Clostridium/isolamento & purificação , DNA Bacteriano/análise , Fusobacterium nucleatum/isolamento & purificação , Humanos , Prevotella/isolamento & purificação , Propionibacterium acnes/isolamento & purificação , RNA Ribossômico 16S/genética , Análise de Sequência de RNA
7.
Exp Parasitol ; 127(2): 409-17, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20920501

RESUMO

To evaluate the presence of Toxoplasma gondii in edible farmed shellfish, 1734 shellfish specimens i.e., 109 Crassostrea gigas (6 pools), 660 Mytilus galloprovincialis (22 pools), 804 Tapes decussatus (28 pools) and 161 Tapes philippinarum (6 pools), were collected from the Varano Lagoon (Apulia, Italy). Shellfish from 62 pools were subjected to two molecular techniques: a nested-PCR assay, and a fluorescent amplicon generation (FLAG) real-time PCR assay, both based on the multi-copy B1 target, were performed. One pooled sample of gills from C. gigas and one pooled sample of haemolymphs from T. decussatus were assessed as positive for T. gondii DNA by both techniques. The results demonstrated the presence of T. gondii in edible farmed C. gigas and T. decussatus and indicate that there may be a considerable health threat involved in eating contaminated raw shellfish.


Assuntos
Parasitologia de Alimentos , Moluscos/parasitologia , Reação em Cadeia da Polimerase/métodos , Frutos do Mar/parasitologia , Toxoplasma/isolamento & purificação , Animais , Aquicultura , Sequência de Bases , Bivalves/genética , Bivalves/parasitologia , Crassostrea/genética , Crassostrea/parasitologia , DNA/análise , DNA/química , DNA de Protozoário/análise , DNA de Protozoário/química , Itália , Moluscos/genética , Mytilus/genética , Mytilus/parasitologia , Toxoplasma/genética
8.
J Ultrasound ; 13(2): 57-60, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23396897

RESUMO

The authors report a case of ischemic stroke caused by a floating thrombus in the common carotid artery and review the diagnostic techniques used to identify the cause of ischemic strokes. They also examine the possible origins of idiopathic carotid thrombi and the current options for their management, with emphasis on the difficulties and risks associated with medical and surgical approaches.

9.
J Clin Microbiol ; 47(11): 3732-4, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19776231

RESUMO

Matrix-assisted laser desorption ionization-time of flight mass spectrometry has emerged as a rapid, cost-effective alternative for bacterial species identification. Identifying 60 blind-coded nonfermenting bacteria samples, this international study (using eight laboratories) achieved 98.75% interlaboratory reproducibility. Only 6 of the 480 samples were misidentified due to interchanges (4 samples) or contamination (1 sample) or not identified because of insufficient signal intensity (1 sample).


Assuntos
Bactérias Aeróbias/química , Bactérias Aeróbias/classificação , Infecções Bacterianas/diagnóstico , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Erros de Diagnóstico/estatística & dados numéricos , Reprodutibilidade dos Testes
10.
J Laryngol Otol ; 121(4): 341-4, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17083751

RESUMO

BACKGROUND: Bacterial biofilms identified in various medical devices used in otorhinolaryngology, including tympanostomy tubes, voice prostheses, and cochlear implants, can directly colonise mucosal tissues. The upper airways seem to be at high risk for this type of colonisation. Chronic and/or recurrent upper airway infections may be related to the complex structural and biochemical (quorum sensing) organisation of the biofilm which interferes with the activity of antibiotics (including those with proven in vitro efficacy), thus promoting the establishment of a chronic infection eradicable only by surgical treatment. Biofilm formation plays a role in upper respiratory infections: it not only explains the resistance of these infections to antibiotic therapy but it also represents an important element that contributes to the maintenance of a chronic inflammatory reaction. OBJECTIVES: To document the presence of biofilms in surgical tissue specimens from patients with recurrent infection diseases, and identify their possible role in the chronicity of these infectious processes. METHOD: We examined 32 surgical specimens from the upper respiratory tract (tonsils, adenoids, mucosa from the ethmoid and maxillary sinuses) of 28 patients (20 adults, eight children) with upper airway infections that had persisted despite repeated treatment with anti-inflammatory agents and antibiotics with demonstrated in vitro efficacy. Tissues were cultured using conventional methods and subjected to scanning electron microscopy for detection of biofilm formation. RESULTS: Over 80 per cent (26/32; 81.3 per cent) of the tissue specimens were culture-positive. Bacterial biofilms (associated in most cases with coccoid bacteria) were observed in 65.6 per cent of the tissue samples.


Assuntos
Biofilmes , Tecido Linfoide/microbiologia , Mucosa Nasal/microbiologia , Infecções Respiratórias/microbiologia , Adulto , Biofilmes/crescimento & desenvolvimento , Criança , Haemophilus/isolamento & purificação , Humanos , Microscopia Eletrônica de Varredura , Pessoa de Meia-Idade , Staphylococcaceae/isolamento & purificação , Streptococcaceae/isolamento & purificação
11.
Clin Pharmacol Ther ; 69(1): 24-31, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11180035

RESUMO

OBJECTIVE: Our objective was to compare the intravenous and oral pharmacokinetics of tacrolimus among subjects of three different ethnic backgrounds, African American, white, and Latin American. METHODS: Ten African American, 12 white, and 12 Latin American subjects received intravenous and oral tacrolimus in an open-label, two-period, parallel group study. All of the subjects received intravenous tacrolimus (0.015 mg/kg) as a constant infusion over 4 hours and oral tacrolimus capsules (5 mg) as single doses in randomized order. Concentrations of tacrolimus and its metabolites were measured in whole blood with the use of a validated HPLC-mass spectrometry assay. RESULTS: There were no significant differences in pharmacokinetic parameters among the three study groups after intravenous administration of the drugs. After oral administration, the tacrolimus maximum concentration was significantly lower (P < .01) in the African American subjects (20.8 microg/L) than in the white subjects (37.8 microg/L) and Latin American subjects (33.0 microg/L). Absolute bioavailability was significantly lower (P = .01) in the African American subjects (11.9%) and in the Latin American subjects (14.4%) than in the white subjects (18.8%). After the oral dose, the area under the plasma concentration-time curve was lower in the African American subjects (179 microg/L x h, geometric mean) than in the white (293 microg/L x h) and Latin American subjects (239 microg/L x h, differences not statistically significant). Maximum concentration (P < .02) and area under the plasma concentration-time curve (not statistically significant) of the main tacrolimus metabolite 13-O-desmethyl tacrolimus was lower in the African American subjects than in the white and Latin American subjects. CONCLUSIONS: Significant differences in tacrolimus pharmacokinetics exist among the three different ethnic groups. Our results indicate that this may result from differences in intestinal CYP3A or P-glycoprotein activities.


Assuntos
Etnicidade , Imunossupressores/farmacocinética , Tacrolimo/farmacocinética , Adulto , Negro ou Afro-Americano , População Negra , Feminino , Hispânico ou Latino , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/sangue , Infusões Intravenosas , Masculino , Tacrolimo/administração & dosagem , Tacrolimo/sangue , População Branca
12.
Riv Biol ; 93(1): 175-81, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10901061

RESUMO

Small phosphorylated chromatin peptides exert a homeostatic regulation on gene expression which causes a strong inhibition of RNA synthesis and growth of neoplastic and fast-growing cells and a remarkable activation of metabolic pathways slowed down in ageing. By biochemical and mass spectrometry analysis, some molecular models of these peptides have been designed and synthesised. Recent studies show that it is possible to find peptidomimetic structures, such as citric acid, able to reproduce the antiproliferative effect. The mechanism of action has been investigated and partially clarified.


Assuntos
Diferenciação Celular/genética , Divisão Celular/genética , Peptídeos/fisiologia , Ácido Cítrico
13.
AAPS PharmSci ; 2(1): E4, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11741220

RESUMO

Pharmacogenetics and pharmacogenomics deal with the genetic basis underlying variable drug response in individual patients. The traditional pharmacogenetic approach relies on studying sequence variations in candidate genes suspected of affecting drug response. On the other hand, pharmacogenomic studies encompass the sum of all genes, i.e., the genome. Numerous genes may play a role in drug response and toxicity, introducing a daunting level of complexity into the search for candidate genes. The high speed and specificity associated with newly emerging genomic technologies enable the search for relevant genes and their variants to include the entire genome. These new technologies have essentially spawned a new discipline, termed pharmacogenomics, which seeks to identify the variant genes affecting the response to drugs in individual patients. Moreover, pharmacogenomic analysis can identify disease susceptibility genes representing potential new drug targets. All of this will lead to novel approaches in drug discovery, an individualized application of drug therapy, and new insights into disease prevention. Current concepts in drug therapy often attempt treatment of large patient populations as groups, irrespective of the potential for individual, genetically-based differences in drug response. In contrast, pharmacogenomics may help focus effective therapy on smaller patient subpopulations which although demonstrating the same disease phenotype are characterized by distinct genetic profiles. Whether and to what extent this individual, genetics-based approach to medicine results in improved, economically feasible therapy remain to be seen. To exploit these opportunities in genetic medicine, novel technologies will be needed, legal and ethical questions must be clarified, health care professionals must be educated, and the public must be informed about the implications of genetic testing in drug therapy and disease management.


Assuntos
Tratamento Farmacológico , Genoma Humano , Preparações Farmacêuticas/metabolismo , Farmacogenética , Animais , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Variação Genética , Humanos
14.
J Pharmacol Exp Ther ; 291(1): 131-9, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10490896

RESUMO

We compared the intestinal metabolism of the structurally related 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors lovastatin and pravastatin in vitro. Human small intestinal microsomes metabolized lovastatin to its major metabolites 6'beta-hydroxy (apparent K(m) = 11.2 +/- 3.3 microM) and 6'-exomethylene (apparent K(m) = 22.7 +/- 9.0 microM) lovastatin. The apparent K(m) values were similar for lovastatin metabolism by human liver microsomes. 6'beta-Hydroxylovastatin formation by pig small intestinal microsomes was inhibited with the following inhibition K(i) values: cyclosporine, 3.3 +/- 1.2 microM; ketoconazole, 0.4 +/- 0.1 microM; and troleandomycin, 0.8 +/- 0.9 microM. K(i) values for 6'-exomethylene lovastatin were similar. Incubation of pravastatin with human small intestinal microsomes resulted in the generation of 3'alpha,5'beta, 6'beta-trihydroxypravastatin (apparent K(m) = 4560 +/- 1410 microM) and hydroxypravastatin (apparent K(m) = 5290 +/- 1740 microM). In addition, as in the liver, pravastatin was metabolized in the small intestine by sulfation and subsequent degradation to its main metabolite 3'alpha-iso-pravastatin. It was concluded that lovastatin is metabolized by cytochrome P-450 3A enzymes in the small intestine. Compared with lovastatin, the cytochrome P-450-dependent intestinal intrinsic clearance of pravastatin was >5000-fold lower and cannot be expected to significantly affect its oral bioavailability or to be a significant site of drug interactions.


Assuntos
Hidrocarboneto de Aril Hidroxilases , Inibidores de Hidroximetilglutaril-CoA Redutases/metabolismo , Intestino Delgado/metabolismo , Lovastatina/metabolismo , Pravastatina/metabolismo , Animais , Ciclosporina/farmacologia , Citocromo P-450 CYP3A , Inibidores das Enzimas do Citocromo P-450 , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Técnicas In Vitro , Cetoconazol/farmacologia , Masculino , Microssomos Hepáticos/metabolismo , Oxirredutases N-Desmetilantes/antagonistas & inibidores , Oxirredutases N-Desmetilantes/metabolismo , Suínos , Troleandomicina/farmacologia
15.
Biol Chem ; 380(1): 31-40, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10064134

RESUMO

Small acidic peptides have been isolated from biological fluids (blood and seminal plasma) and from chromatin of several tissues. Their biological activity is related to the control of cell growth and gene expression. This work is an approach to the study of peptide structure-function relationship. Purified fractions from seminal plasma and pea bud chromatin were subjected to fast ion bombardment mass spectrometry. The results obtained were analyzed according to biochemical characteristics of the peptides studied and some possible molecular models have been designed. Two of the proposed sequences were synthesized and their biological activity assayed in cells and cell-free systems. The results demonstrate that the synthetic peptides are able to bind to DNA in the presence of divalent cations (Mg2+, Fe2+, Cu2+) with consequent inhibition of DNA transcription.


Assuntos
Cromatina/química , DNA/química , Oligopeptídeos/química , Pisum sativum/química , Proteínas de Plantas/química , Sêmen/química , Animais , Cátions Bivalentes , Bovinos , Cromatografia Líquida de Alta Pressão , DNA/metabolismo , Células HL-60 , Humanos , Concentração de Íons de Hidrogênio , Masculino , Modelos Moleculares , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/metabolismo , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo , Espectrometria de Massas de Bombardeamento Rápido de Átomos
16.
Drug Metab Dispos ; 27(2): 173-9, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9929499

RESUMO

In an in vitro study, the cytochrome P-450 3A (CYP3A)-dependent metabolism and drug interactions of the 3-hydroxy-3-methylglutaryl-Co A reductase inhibitors lovastatin and pravastatin were compared. Lovastatin was metabolized by human liver microsomes to two major metabolites: 6'beta-hydroxy [Michaelis-Menten constant (Km): 7.8 +/- 2.7 microM] and 6'-exomethylene lovastatin (Km,10.3 +/- 2.6 microM). 6'beta-Hydroxylovastatin formation in the liver was inhibited by the specific CYP3A inhibitors cyclosporine (Ki, 7.6 +/- 2.3 microM), ketoconazole (Ki, 0.25 +/- 0.2 microM), and troleandomycin (Ki, 26.6 +/- 18.5 microM). Incubation of pravastatin with human liver microsomes resulted in the generation of 3'alpha,5'beta, 6'beta-trihydroxy pravastatin (Km, 4,887 +/- 2,185 microM) and hydroxy pravastatin (Km, 20,987 +/- 9,389 microM). The formation rates of 3'alpha,5'beta,6'beta-trihydroxy pravastatin by reconstituted CYP3A enzymes were (1,000 microM pravastatin) 1.9 +/- 0.6 pmol.min-1.pmol CYP3A4 and 0.06 +/- 0.04 pmol.min-1.pmol CYP3A5, and the formation rates of hydroxy pravastatin were 0.12 +/- 0.02 pmol.min-1.pmol CYP3A4 and 0.02 +/- 0.004 pmol.min-1.pmol CYP3A5. The specific CYP3A inhibitors cyclosporine, ketoconazole, and troleandomycin significantly inhibited hydroxy pravastatin formation by human liver microsomes, but only ketoconazole inhibited 3'alpha, 5'beta,6'beta-trihydroxy pravastatin formation, suggesting that other CYP enzymes are involved in its formation. It is concluded that, compared with lovastatin [CLint formation 6'beta-hydroxylovastatin (microl.min-1.mg-1): 199 +/- 248, 6'-exomethylene lovastatin: 138 +/- 104)], CYP3A-dependent metabolism of pravastatin [CLint formation 3'alpha,5'beta, 6'beta-trihydroxy pravastatin (microl.min-1.mg-1): 0.03 +/- 0.03 and hydroxy pravastatin: 0.02 +/- 0.02] is a minor elimination pathway. In contrast to lovastatin, drug interactions with pravastatin CYP3A-catalyzed metabolism cannot be expected to have a clinically significant effect on its pharmacokinetics.


Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lovastatina/farmacologia , Microssomos Hepáticos/efeitos dos fármacos , Pravastatina/farmacologia , Biotransformação , Cromatografia Líquida de Alta Pressão , Ciclosporinas/farmacocinética , Interações Medicamentosas , Feminino , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacocinética , Imunossupressores/farmacocinética , Técnicas In Vitro , Cinética , Lovastatina/farmacocinética , Masculino , Microssomos Hepáticos/enzimologia , Pravastatina/farmacocinética
17.
Mol Biol Rep ; 25(3): 163-72, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9700052

RESUMO

Structural features of a class of chromatin peptides are studied in the aim of understanding their mechanism of action. They have been reported as a family of small acidic peptides that can affect cell proliferation and RNA transcription. Mass spectrometry analysis has suggested some molecular models of possible sequences that might be present in this group of peptides. These sequences have been synthesised and their chromatographic and electrophoretic behaviour is compared with that obtained from peptides extracted from pea bud chromatin. In this way electric charge and hydrophilic properties of the native peptides are evaluated. On the basis of these data and those obtained from further mass spectrum analysis new models for native peptides are proposed.


Assuntos
Cromatina/química , Proteínas Cromossômicas não Histona/química , Oligopeptídeos/química , Cromatografia por Troca Iônica , Cromatografia em Camada Fina , Proteínas Cromossômicas não Histona/síntese química , Proteínas Cromossômicas não Histona/isolamento & purificação , Eletroforese em Acetato de Celulose , Concentração de Íons de Hidrogênio , Hidrólise , Ponto Isoelétrico , Espectrometria de Massas , Peso Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/farmacologia , Pisum sativum/química , Fosforilação , Ácido Pirrolidonocarboxílico
18.
West J Med ; 167(5): 322-9, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9392980

RESUMO

We describe our experience with administering intramuscular triamcinolone acetonide to 22 steroid-dependent patients with asthma. These patients represent the minority of those with asthma whose disease is characterized by frequent emergency department visits, hospital admissions, and long-term dependency on oral corticosteroid therapy. The participants were randomly assigned to 2 treatment groups, one group receiving 120 mg of intramuscular triamcinolone acetonide, the second receiving 360 mg as a series of three 120-mg daily doses. We determined relative efficacy by comparing peak expiratory flow rates and incidents of emergency department visits, hospital admissions, and ventilatory failure of the study and during the 12 months before enrollment. Peak expiratory flow rates improved significantly in both groups. The mean (+/- standard deviation [SD]) monthly percentage of predicted peak expiratory flow on the study was 88.6 +/- 3.7% and 91.2 +/- 3.9% compared with 63 +/- 15.1% and 64 +/- 14.5% at entry in patients receiving 120 and 360 mg, respectively (P < 0.02). Patients receiving 120 mg required 8 hospital stays and 8 emergency department visits compared with 27 hospital stays and 72 emergency department visits in the previous year (P < 0.05). Patients receiving 360 mg required 5 hospital stays and 5 emergency department visits compared with 33 hospital stays and 34 emergency department visits in the previous year (P < 0.05). The average monthly interval (+/- SD) between exacerbations was 2.7 +/- 2.3 and 7.8 +/- 3.5 for patients receiving 120 mg and 360 mg, respectively. A total of 25 intubations was required in the previous year and only 1 during the study. The incidence of cushingoid facies, weight gain, and hypertension was reduced in both groups (P < 0.05). Total steroid use was reduced in both groups (P < 0.02). A dose of 360 mg produced a longer exacerbation-free period than 120 mg (P < 0.02).


Assuntos
Anti-Inflamatórios/administração & dosagem , Asma/tratamento farmacológico , Triancinolona/administração & dosagem , Adulto , Idoso , Asma/fisiopatologia , Doença Crônica , Intervalos de Confiança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pico do Fluxo Expiratório , Estatísticas não Paramétricas
20.
Peptides ; 15(1): 7-13, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8015983

RESUMO

We previously reported the isolation of low molecular weight phosphorylated peptides from the chromatin of several tissues. The chromatin peptides show a regulatory activity on DNA in vitro transcription and on cell growth and differentiation. In this paper, we report a molecular model of the native peptides designed according to the structural information obtained by means of biochemical and mass spectrometry analysis: pyroGlu-Ala-Gly-Glu-Asp-Ser(P)-Asp-Glu-Glu-Asn. This or very similar sequences are present in many transcription factors; on the basis of the structural model we presented and of related protein sequences, we have synthesized the peptide pyroGlu-Asp-Asp-Ser-Asp-Glu-Glu-Asn. This peptide affects transcription rate in reconstituted systems in vitro and in isolated nuclei; moreover, it inhibits the growth of HL60 cells with a parallel stimulus of differentiation.


Assuntos
Diferenciação Celular/fisiologia , Divisão Celular/fisiologia , Cromatina/química , Modelos Moleculares , Peptídeos/química , Transcrição Gênica , Sequência de Aminoácidos , Animais , Sistema Livre de Células , Espectrometria de Massas , Dados de Sequência Molecular , Peso Molecular , Células PC12 , Fosforilação , Relação Estrutura-Atividade , Truta
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