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2.
Afr. J. Clin. Exp. Microbiol ; 23(4): 426-436, 2022. tables
Artigo em Inglês | AIM (África) | ID: biblio-1396798

RESUMO

Contexte: L'émergence et la montée en puissance des infections causées par des isolats d'entérobactéries ultrarésistantes (XDR) et pandrug-résistantes (PDR) constituent un sérieux défi clinique et de santé publique. L'isolement de bactéries Gram-négatives PDR (GNB) en milieu clinique est très rare et plus rare est l'infection causée par XDR GNB. En dehors des options thérapeutiques restreintes, ces infections sont associées à une augmentation de la mortalité et de la morbidité. Des études urgentes pour réévaluer les options thérapeutiques existantes et la recherche de nouvelles molécules antibiotiques sont désespérément nécessaires. Les objectifs de cette étude étaient de signaler l'émergence d'infections à CRE multirésistantes (MDR), difficiles à menacer, rarement rencontrées dans notre hôpital et d'enquêter sur leur épidémiologie moléculaire. Méthodologie: Il s'agissait d'une analyse observationnelle rétrospective de six patients atteints d'infections graves causées par des isolats d'entérobactéries XDR et PDR à l'hôpital universitaire Mubarak AL Kabeer, Jabriya, Koweït, sur une période d'un an et demi. Les mécanismes de résistance de ces isolats ont ensuite été étudiés de manière prospective par caractérisation moléculaire et études génomiques. Résultats: La majorité des infections ont été causées par Klebsiella pneumoniae (83,3%, 5/6) et une (16,6%) a été causée par Escherichia coli. Trois patients avaient une infection du sang (BSI), un avait à la fois une BSI et une infection des voies urinaires (UTI), un avait une infection des voies respiratoires et le dernier avait une UTI. Deux patients ont été infectés par des producteurs d'OXA-48, un patient a été infecté par un producteur de NDM-1, un patient a été infecté par un producteur de NDM-5, un patient a été infecté par un producteur de NDM-1 et d'OXA-48 et le dernier patient a été infecté avec le producteur NDM-5 et OXA-181. Pour un traitement définitif, tous les patients ont reçu une thérapie combinée. Le taux de mortalité était élevé (50.0%). Conclusion: Le taux de mortalité élevé associé aux infections XDR et PDR Enterobacterales et les options antimicrobiennes limitées pour le traitement soulignent la nécessité d'améliorer la détection de ces infections, l'identification de mesures préventives efficaces et le développement de nouveaux agents avec une efficacité clinique fiable contre elles.


Assuntos
Humanos , Infecção Hospitalar , Genes MDR , Infecções , Kuweit
3.
Eur J Neurol ; 27(6): 928-943, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32056347

RESUMO

Alzheimer's disease (AD) is characterized by high heterogeneity in disease manifestation, progression and risk factors. High phenotypic variability is currently regarded as one of the largest hurdles in early diagnosis and in the design of clinical trials; there is therefore great interest in identifying factors driving variability that can be used for patient stratification. In addition to genetic and lifestyle factors, the individual's sex and gender are emerging as crucial drivers of phenotypic variability. Evidence exists on sex and gender differences in the rate of cognitive deterioration and brain atrophy, and in the effect of risk factors as well as in the patterns of diagnostic biomarkers. Such evidence might be of high relevance and requires attention in clinical practice and clinical trials. However, sex and gender differences are currently seldom appreciated; importantly, consideration of sex and gender differences is not currently a focus in the design and analysis of clinical trials for AD. The objective of this position paper is (i) to provide an overview of known sex and gender differences that might have implications for clinical practice, (ii) to identify the most important knowledge gaps in the field (with a special regard to clinical trials) and (iii) to provide conclusions for future studies. This scientific statement is endorsed by the European Academy of Neurology.


Assuntos
Doença de Alzheimer , Transtornos Cognitivos , Cognição , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/epidemiologia , Peptídeos beta-Amiloides , Biomarcadores , Ensaios Clínicos como Assunto , Humanos , Neurologia , Caracteres Sexuais , Proteínas tau
4.
Lupus ; 26(14): 1483-1490, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28467293

RESUMO

Objective Intravenous belimumab 10 mg/kg is approved as an add-on therapy in patients with active, autoantibody-positive systemic lupus erythematosus. This study aimed to assess the impact of belimumab on immune response to pneumococcal vaccination in patients with systemic lupus erythematosus. Methods This was a Phase 4, open-label study (GSK BEL115470; NCT01597492) conducted in the United States. Patients were randomized (7:9) to receive a 23-valent pneumococcal vaccination four weeks prior to (pre-belimumab cohort) or 24 weeks after (belimumab-concurrent cohort) commencing four-weekly belimumab 10 mg/kg intravenous treatment plus standard systemic lupus erythematosus therapy. Analyses of vaccine titers were performed on the as-treated population (received ≥1 dose of belimumab). The primary endpoint was the proportion of patients with positive antibody responses (≥2-fold increase from pre-vaccination levels, or post-vaccination level ≥ 0.6 µg/mL if pre-vaccination levels were unquantifiable) to ≥1 of 23 pneumococcal vaccine serotypes, four weeks post vaccination. Other endpoints included the proportion of patients with positive antibody responses to ≥2 to ≥10, and ≥11-23 (post hoc analysis) of serotypes. Safety was assessed by monitoring adverse events. Results Seventy-nine patients received pneumococcal vaccination (pre-belimumab cohort, n = 34; belimumab-concurrent cohort, n = 45). The majority (87.3% [69/79]) completed the study; 10 (12.7%) withdrew (patient request, n = 3; adverse event, n = 3; lost to follow-up, n = 2; other, n = 2). At Week 4 post-vaccination, 97.0% (32/33) and 97.6% (40/41) of patients (pre-belimumab and concurrent belimumab cohorts, respectively) had a positive response to ≥1 of 23 pneumococcal serotypes. Over 85% of patients in both cohorts responded to ≥10 of serotypes, approximately 80% responded to ≥12 serotypes, and approximately two-thirds responded to ≥16 serotypes. Little difference was observed between cohorts across a broad response, up to 23 serotypes. Eight (23.5%) patients experienced an adverse event considered by the investigator to be treatment-related in the pre-belimumab cohort and four (8.9%) in the belimumab-concurrent cohort; seven patients experienced non-fatal serious adverse events (pre-belimumab cohort, 11.8% [ n = 4]; concurrent-belimumab cohort, 6.7% [ n = 3]), and no deaths were reported. Conclusion The proportion of patients generating a response to ≥1 pneumococcal serotype did not differ between the pre-belimumab and belimumab-concurrent cohorts; the proportions were also comparable across a broader response (from ≥2 serotypes to 23 serotypes).


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Imunossupressores/administração & dosagem , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Vacinas Pneumocócicas/administração & dosagem , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Formação de Anticorpos/imunologia , Autoanticorpos/imunologia , Feminino , Humanos , Imunossupressores/efeitos adversos , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Vacinas Pneumocócicas/imunologia , Sorogrupo , Vacinação
5.
Nanoscale ; 9(16): 5085-5093, 2017 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-28134383

RESUMO

In the past decade, there has been considerable interest in radiosensitization using gold nanoparticles that accumulate specifically in cancerous tissue while sparing normal tissues. Despite this interest, it remains unclear which nanoparticle morphologies, cellular uptake, or cytoplasmic distribution elicit optimal radiosensitization. We introduce gold nanotriangles (AuNTs) as a possible X-ray radiotherapy sensitizer. In this study, we first explored a large-scale synthetic method for the production of high quality monodisperse AuNTs. Second, we conducted in vitro and in vivo experiments to evaluate the effect of PEGylated AuNTs (pAuNTs) on cellular uptake, cytotoxicity, bio-distribution, and radiosensitization on radiation-resistant human Glioblastoma Multiforme (GBM) cells. Our results suggest that the new scale up synthesis methodology consistently produced high quality AuNTs and pAuNTs which had nonspecific cellular uptake without any obvious cytotoxicity and exhibited excellent radiosensitization.


Assuntos
Glioblastoma/radioterapia , Ouro , Nanopartículas Metálicas , Radiossensibilizantes , Animais , Humanos , Células MCF-7 , Masculino , Camundongos , Raios X , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Indian J Med Microbiol ; 29(1): 65-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21304200

RESUMO

Rhodococcus equi , previously known as Corynebacterium equi, is one of the most important causes of zoonotic infection in grazing animals. Increased cases of human infection with R. equi have been reported especially in immunocompromised patients. Infection in immunocompetent patients is extremely rare. We report a case of R. equi bacteremia in a 26-day-old immunocompetent infant with recurrent swellings on different parts of the body. To the best of our knowledge, this is the first ever report of R. equi bacteremia from an immunocompetent patient from Northern India.


Assuntos
Infecções por Actinomycetales/diagnóstico , Bacteriemia/diagnóstico , Rhodococcus equi/isolamento & purificação , Infecções por Actinomycetales/microbiologia , Infecções por Actinomycetales/patologia , Bacteriemia/microbiologia , Bacteriemia/patologia , Técnicas Bacteriológicas , Humanos , Índia , Recém-Nascido , Masculino
8.
Br Dent J ; 208(2): 65-9, 2010 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-20098382

RESUMO

AIMS: This study surveyed members of the Oral Surgery (OS) register and requested a self assessment of their surgical competencies with regard to both core and extended procedures, as defined by the OS curriculum. Details of education, training backgrounds and working patterns were also requested. METHODS: Members of the OS register were identified on the General Dental Council website and mailed a questionnaire. Replies were anonymous. RESULTS: Three hundred and seventy-three valid replies were received. Seventy-five percent of respondents were on the OS specialist list only (single registrants) and 25% of respondents were on both the OS and oral and maxillofacial surgery (OMFS) specialist lists (dual-registrants). Sixty-two percent of single registrants did not feel comfortable performing all core procedures compared to 13% of dual-registrants. Fifty-one percent of OS single registrants felt comfortable performing some extended procedures, as did 99% of dual-registrants. Fifty percent of single registrants and 100% of dual-registrants had a higher qualification. Thirty-seven percent of single registrants had undergone some formally-approved registrar-level training; 98% of dual-registrants had done likewise. Twenty-one percent of single registrants practised exclusively in the private sector compared to 8% of dual-registrants. CONCLUSION: Extended competencies are being practised by members of the OS register with wide-ranging educational and training backgrounds.


Assuntos
Competência Clínica , Padrões de Prática Odontológica , Cirurgia Bucal/educação , Cirurgia Bucal/organização & administração , Humanos , Sistema de Registros , Autoavaliação (Psicologia) , Inquéritos e Questionários , Reino Unido
9.
Br Dent J ; 206(7): 353-4, 2009 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-19357665

RESUMO

The nature of the primary dental undergraduate qualification is continually evolving to keep pace with the ever changing climate of medical and dental education and postgraduate speciality training. In the aftermath of "Modernising Medical Careers", there has been a surge in interest in careers of dental origin by members of the medical profession, particularly in the specialities of oral and maxillofacial surgery (OMFS), oral medicine and oral surgery. Furthermore, following the suggestion by the recent Postgraduate Medical Education and Training Board (PMETB) report into OMFS training that both registrable medical and dental degrees be obtainable by the age of 26 much attention has focussed on the entity of the accelerated undergraduate dental qualification. In this article we report our personal and educational experiences one year after enrolling in the UK's first official dental undergraduate degree for medical graduates, an accelerated three year BDS programme provided by King's College London.


Assuntos
Educação em Odontologia/métodos , Estudantes de Medicina , Cirurgia Bucal/educação , Currículo , Humanos , Londres , Reino Unido , Universidades
10.
J Plast Reconstr Aesthet Surg ; 62(4): 539-41, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18061546

RESUMO

The exact location and topography of defects resulting from surgical excision of cutaneous malignancies of the auricle demand a customized approach based on an awareness of locally redundant tissue. With advancing age, the earlobe becomes ideal for this reconstructive role and we describe an earlobe flap created along the longitudinal axis of lobular tissue. This reliable, simple, one-step procedure provides adequate tissue cover for defects of the antitragus and adjoining concha. Flap vascularity is satisfactory and although the overall size of the ear is reduced, this is accepted for a rejuvenated shape and minimal morbidity.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Pavilhão Auricular/cirurgia , Neoplasias da Orelha/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Neoplasias Cutâneas/cirurgia , Idoso de 80 Anos ou mais , Feminino , Humanos , Retalhos Cirúrgicos
11.
Rheumatology (Oxford) ; 45(1): 53-60, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16278288

RESUMO

OBJECTIVES: To evaluate the relationship between disease damage and bone mineral density (BMD) in women with systemic lupus erythematosus (SLE). METHODS: A cross-sectional study was conducted among 307 women with SLE. Patients attended a single clinic visit that included an interview, physical examination, laboratory testing and BMD measurements (hip and/or lumbar spine). Women were stratified by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology cumulative disease damage index (SDI) > or =1 (Damage) vs SDI=0 (No Damage), and prior use of corticosteroids (CS), yielding four groups: (1) Damage/CS(+) (n=138), (2) Damage/CS(-) (n=23), (3) no Damage/CS(-) (n=100), and (4) no Damage/CS(-) (n=46). RESULTS: Mean age at SLE diagnosis was 32.7 +/- 11.8 yr, 24.4% were African American, 65.0% were premenopausal, and mean SDI +/- S.D. was 1.3 +/- 1.8. In the unadjusted and adjusted models controlling for significant univariate risk factors for osteoporosis, the reference group (Group 1) had significantly lower mean BMD T-scores at the hip and lumbar spine than groups having no disease damage (Groups 3 and 4) independent of CS use status. Similar hip and lumbar spine mean BMD T-scores were observed in women with disease damage with and without CS exposure (Groups 1 and 2). CONCLUSIONS: Women with SLE having disease damage and no CS use had BMD T-scores at the hip and lumbar spine similar to those of women with disease damage and prior CS use. These findings suggest an association between disease damage and lower BMD T-scores in women with SLE.


Assuntos
Corticosteroides/uso terapêutico , Densidade Óssea/fisiologia , Lúpus Eritematoso Sistêmico/fisiopatologia , Adulto , Doenças Ósseas Metabólicas/etiologia , Doenças Ósseas Metabólicas/fisiopatologia , Estudos Transversais , Feminino , Humanos , Estilo de Vida , Vértebras Lombares , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Menopausa , Osteoporose/etiologia , Osteoporose/fisiopatologia , Ossos Pélvicos
13.
J Craniofac Surg ; 12(5): 501-4, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11572259

RESUMO

The concept of including external oblique aponeurosis along with the time-tested groin flap as a single vascularized unit heralds a versatile and unique application in the armamentarium presently available. This concept, though simple, has not been previously reported in the world literature. In view of its potential benefits and simplicity, we felt the need to bring this concept to the attention of our colleagues.


Assuntos
Virilha , Mãos/cirurgia , Transplante de Pele/métodos , Retalhos Cirúrgicos , Tendões/transplante , Criança , Feminino , Virilha/irrigação sanguínea , Virilha/cirurgia , Traumatismos da Mão/cirurgia , Humanos , Artéria Ilíaca , Masculino , Retalhos Cirúrgicos/irrigação sanguínea
14.
Biosens Bioelectron ; 16(4-5): 313-7, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11390219

RESUMO

A novel method for estimating triglycerides is reported. Porous silicon, prepared from p-type (100) crystalline silicon was thermally oxidized and used to immobilise lipase, an enzyme, which hydrolyses triglycerides resulting in the formation of fatty acids. This causes a change in the pH of the solution. Enzyme solution-oxidized porous silicon-crystalline silicon structure was used to detect changes in pH during the hydrolysis of tributyrin as a shift in the capacitance-voltage (C-V) characteristics. Detailed calibration of the sensor is included.


Assuntos
Técnicas Biossensoriais , Triglicerídeos/análise , Silício
15.
Public Opin Q ; 65(1): 22-44, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11264053

RESUMO

The key to understanding why people overreport is that those who are under the most pressure to vote are the ones most likely to misrepresent their behavior when they fail to do so. Among all nonvoters, the most likely to overreport are the more educated, partisan, and religious, and those who have been contacted and asked to vote for a candidate. The greater the concentration of African-American and Latino nonvoters in a district, the greater the probability of overreporting in those districts, both among those in the relevant minority group and among white Anglos. White nonvoters are more likely to overreport in the Deep South than elsewhere. Overreporting matters: using reported votes in place of validated votes substantially distorts standard multivariate explanations of voting, increasing the apparent importance of independent variables that are related in the same direction to both overreporting and voting and sharply decreasing the apparent importance of independent variables related in opposing directions to those two variables.

16.
Br J Pharmacol ; 130(8): 1927-32, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10952684

RESUMO

This study examined whether activation of 5HT(1B) receptors in the rodent globus pallidus (GP) could reduce GABA release in vitro and reverse reserpine-induced akinesia in vivo. Microdissected slices of GP from male Sprague Dawley rats (300-350 g) were preloaded with [(3)H]-GABA. During subsequent superfusion, 4 min fractions were collected for analysis of release. The effects of the 5HT(1B) receptor agonist, 3-(1,2,5,6-tetrahydropyrid-4-yl)pyrrolo[3, 2-b]pyrid-5-one (CP-93129), on 25 mM KCl-evoked release were examined using a standard dual stimulation paradigm. Male Sprague Dawley rats (270 - 290 g), stereotaxically cannulated above the GP, were rendered akinetic by injection of reserpine (5 mg kg(-1) s.c.). Eighteen hours later, the rotational behaviour induced by unilateral injection of CP-93129 was examined. CP-93129 (0.6-16.2 microM) produced a concentration-dependent inhibition of 25 mM KCl-evoked [(3)H]-GABA release reaching a maximum inhibition of 52.5+/-4.5%. The effect of a submaximal concentration of CP-93129 (5.4 microM) was fully inhibited by the 5HT(1B) receptor antagonist, isamoltane (10 microM). Following intrapallidal injection, CP-93129 (30-330 nmol in 0.5 microl) produced a dose-dependent increase in net contraversive rotations reaching a maximum of 197+/-32 rotations in 240 min at 330 nmol. Pre-treatment with isamoltane (10 nmol in 1 microl) inhibited the effects of a submaximal dose of CP-93129 (220 nmol) by 84+/-6%. These data suggest that at least some 5HT(1B) receptor function as heteroreceptors in the GP, reducing the release of GABA. Moreover, CP-93129-mediated activation of these receptors in the GP provides relief of akinesia in the reserpine-treated rat model of PD.


Assuntos
Globo Pálido/efeitos dos fármacos , Transtornos dos Movimentos/prevenção & controle , Piridinas/farmacologia , Pirróis/farmacologia , Receptores de Serotonina/efeitos dos fármacos , Agonistas do Receptor de Serotonina/farmacologia , Ácido gama-Aminobutírico/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Globo Pálido/metabolismo , Técnicas In Vitro , Masculino , Transtornos dos Movimentos/etiologia , Propanolaminas/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor 5-HT1B de Serotonina , Reserpina/efeitos adversos , Antagonistas da Serotonina/farmacologia , Trítio , Ácido gama-Aminobutírico/metabolismo
17.
Brain Res ; 862(1-2): 280-3, 2000 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-10799700

RESUMO

Changes in GABA(A) receptor alpha(1) subunit gene expression occur in the globus pallidus and substantia nigra pars reticulata following lesions of the nigrostriatal tract. To determine whether these changes are translated at the protein level, we performed quantitative autoradiography with the alpha(1) selective ligand, [3H]zolpidem, and the non-selective benzodiazepine site ligand, [3H]Ro 15-1788. Binding of both [3H]zolpidem and [3H]Ro 15-1788 was significantly increased in the substantia nigra pars reticulata (13. 5+/-4.1 and 26.3+/-2.9%, respectively) and significantly reduced in the globus pallidus (20.9+/-0.8 and 18.3+/-1.3%, respectively). These changes in alpha(1) subunit protein expression may help to compensate for the pathological changes in GABAergic activity that occur after striatal dopamine depletion.


Assuntos
Flumazenil/farmacologia , Agonistas GABAérgicos/farmacologia , Moduladores GABAérgicos/farmacologia , Globo Pálido/metabolismo , Piridinas/farmacologia , Substância Negra/metabolismo , Animais , Autorradiografia , Flumazenil/metabolismo , Agonistas GABAérgicos/metabolismo , Moduladores GABAérgicos/metabolismo , Globo Pálido/química , Masculino , Degeneração Neural/metabolismo , Degeneração Neural/patologia , Piridinas/metabolismo , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptores de GABA-A/fisiologia , Substância Negra/química , Substância Negra/patologia , Trítio , Zolpidem
18.
Br J Pharmacol ; 129(3): 541-6, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10711353

RESUMO

1. This study examined whether activation of group II metabotropic glutamate (mGlu) receptors in the substantia nigra pars reticulata (SNr) could reverse akinesia in a rodent model of Parkinson's disease (PD). 2. Male Sprague Dawley rats, stereotaxically cannulated above either the SNr or third ventricle, were rendered akinetic by injection of reserpine (5 mg kg-1 s.c.). Eighteen hours later, the rotational behaviour induced by unilateral injection of the group II mGlu receptor agonist, (2S,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl)glycine (DCG-IV), was examined. 3. Following intranigral injection, DCG-IV (0.125-0.75 nmol in 0.1 microliter) produced a dose-dependent increase in net contraversive rotations (n = 6-8 animals per dose), reaching a maximum of 395 +/- 51 rotations 60 min-1 after 0.75 nmol. The effects of DCG-IV (0.5 nmol) were inhibited by 63.0 +/- 9.0% following 30 min pre-treatment with the group II mGlu receptor antagonist, (2S)-alpha-ethylglutamic acid (EGLU; 100 nmol in 0.2 microliter; n = 6). 4. Following intraventricular injection, DCG-IV (0.125-1.5 nmol in 2 microliters) produced a dose-dependent increase in bilateral locomotor activity (n = 6-7 animals per dose), reaching a maximum of 180 +/- 21 locomotor units 30 min-1 after 0.5 nmol. Pre-treatment with EGLU (200 nmol in 2 microliters) inhibited the effects of DCG-IV (0.5 nmol) by 68.2 +/- 12.3% (n = 5). 5. These data show that activation of group II mGlu receptors in the SNr provides relief of akinesia in the reserpinized rat model of PD. The reversal seen following intraventricular administration supports the likely therapeutic benefit of systemically-active group II mGlu receptor agonists in PD.


Assuntos
Anticonvulsivantes/farmacologia , Antipsicóticos/antagonistas & inibidores , Ciclopropanos/farmacologia , Discinesia Induzida por Medicamentos/tratamento farmacológico , Glicina/análogos & derivados , Receptores de Glutamato Metabotrópico/agonistas , Reserpina/antagonistas & inibidores , Animais , Antipsicóticos/administração & dosagem , Antipsicóticos/toxicidade , Glicina/farmacologia , Injeções , Injeções Intraventriculares , Masculino , Atividade Motora/efeitos dos fármacos , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/tratamento farmacológico , Ratos , Ratos Sprague-Dawley , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Reserpina/administração & dosagem , Reserpina/toxicidade , Substância Negra
19.
Neuroscience ; 95(1): 119-26, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10619468

RESUMO

In Parkinson's disease, changes in GABAergic activity occurring downstream of the striatal dopamine loss are accompanied by reciprocal changes in GABA(A) receptor binding, the underlying molecular mechanisms for which are unknown. This study examined whether changes in expression of the genes encoding known GABA(A) receptor subunits (alpha(1-4), beta(1-3), gamma(1-3) and delta) could account for this receptor plasticity using a rodent model of Parkinson's disease with a 6-hydroxydopamine-induced nigrostriatal lesion. Analysis of autoradiograms of the basal ganglia and thalamus revealed changes in expression of only four of the 11 subunits studied. Expression of alpha1 and beta2 subunit genes was altered in a parallel manner following a 6-hydroxydopamine lesion; messenger RNA levels for both were significantly increased in the substantia nigra pars reticulata (11 +/- 4% and 17 +/- 1%, respectively), and significantly reduced in the globus pallidus (18 +/- 3% and 16 +/- 3%, respectively) and parafascicular nucleus (19 +/- 3% and 16 +/- 5%, respectively). Smaller changes in the messenger RNA levels encoding the alpha1 subunit in the lateral amygdala (8 +/- 1% decrease) and the alpha4 and gamma2 subunits in the striatum (10 +/- 2% and 6 +/- 1% increase, respectively) were also observed. No changes in expression were noted for any other subunits in any region studied. Clearly, both region- and subunit-specific regulation of GABA(A) receptor subunit gene expression occurs following a nigrostriatal tract lesion. The changes in expression of the alpha1 and beta2 subunit genes probably contribute to the documented changes in GABA(A) receptor binding following striatal dopamine depletion. Moreover, they provide a molecular basis by which the pathological changes in GABAergic activity in Parkinson's disease may be partially compensated.


Assuntos
Gânglios da Base/fisiologia , Corpo Estriado/patologia , Expressão Gênica , Receptores de GABA-A/genética , Substância Negra/patologia , Tálamo/fisiologia , Animais , Autorradiografia , Corpo Estriado/efeitos dos fármacos , Corpo Estriado/fisiopatologia , Masculino , Mazindol/metabolismo , Vias Neurais/efeitos dos fármacos , Vias Neurais/patologia , Oxidopamina/farmacologia , Isoformas de Proteínas/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Substância Negra/efeitos dos fármacos , Substância Negra/fisiopatologia , Distribuição Tecidual
20.
Chem Biol Interact ; 122(2): 117-35, 1999 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-10528997

RESUMO

Metabolism of the proximate carcinogen trans-3,4-dihydroxy-3,4-dihydrodibenz[c,h]acridine has been examined with rat liver enzymes. The dihydrodiol is metabolized at a rate of 2.4 nmol/nmol of cytochrome P450 1A1/min with microsomes from 3-methylcholanthrene-treated rats, a rate more than 10-fold higher than that observed with microsomes from control or phenobarbital-treated rats. Major metabolises consisted of a diastereomeric pair of bis-dihydrodiols (68-83%), where the new dihydrodiol group has been introduced at the 8,9-position, tetraols derived from bay region 3,4-diol-1,2-epoxides (15-23%), and a small amount of a phenolic dihydrodiol(s) where the new hydroxy group is at the 8,9-position of the substrate. A highly purified monooxygenase system reconstituted with cytochrome P450 1A1 and epoxide hydrolase (17 nmol of metabolites/nmol of cytochrome P450 1A1/min) gave a metabolite profile very similar to that observed with liver microsomes from 3-methylcholanthrene-treated rats. Study of the stereoselectivity of these microsomes established that the (+)-(3S,4S)-dihydrodiol gave mainly the diol epoxide-1 diastereomer, in which the benzylic 4-hydroxyl group and epoxide oxygen are cis. The (-)-(3R,4R)-dihydrodiol gave mainly diol epoxide-2 where these same groups are trans. The major enantiomers of the diastereomeric bis-dihydrodiols are shown to have the same absolute configuration at the 8,9-position. Correlations of circular dichroism spectra suggest this configuration to be (8R,9R). The (8R,9S)-oxide may be their common precursor.


Assuntos
Acridinas/metabolismo , Benzo(a)Antracenos/metabolismo , Carcinógenos/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Epóxido Hidrolases/metabolismo , Microssomos Hepáticos/metabolismo , Acridinas/farmacocinética , Acridinas/toxicidade , Animais , Benzo(a)Antracenos/farmacocinética , Benzo(a)Antracenos/toxicidade , Biotransformação , Carcinógenos/farmacocinética , Carcinógenos/toxicidade , Masculino , Metilcolantreno/toxicidade , Microssomos Hepáticos/enzimologia , Oxirredução , Ratos , Ratos Long-Evans , Estereoisomerismo , Especificidade por Substrato
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