RESUMO
Successful language comprehension requires the combination of individual words into larger linguistic units. In the present minimal-phrase study, we used electroencephalography (EEG) to investigate whether syntactic combination is indexed by changes in neural synchrony, while testing for both token-based and type-based effects. To do this, we analysed intertrial phase coherence (ITPC) elicited by reading two item (words or pseudowords) phrases that were either unifiable or nonunifiable. Results indicated that type-based unifiable phrases elicited increased ITPC relative to all other conditions in the frequency band corresponding to the rate of phrases (0.5 Hz) but not the rate of words (1 Hz). Conversely, we observed a complementary pattern for the N400, which was more sensitive to token-based effects. These findings provide evidence that the combination of single words into larger syntactic structures may be indexed by the synchronous firing of assemblies of neurons oscillating at the rate of phrases during reading.
Assuntos
Eletroencefalografia , Potenciais Evocados , Humanos , Masculino , Feminino , Potenciais Evocados/fisiologia , Idioma , Neurônios , Semântica , LeituraRESUMO
Introduction Counselling in Primary care (CIPC) is a new service introduced by the HSE in 2013, providing short-term counselling for medical-card holders, suffering from mild to moderate mental health problems. Aims To explore GP's views on CIPC for the treatment of mild to moderate mental health disorders. Methods Qualitative semi-structured interviews were conducted with GPs who had previously utilized the CIPC service in the Cork/ Kerry region. Forty GPs were identiô¡ed and sent invitation letters. GPs were purposefully sampled based on criteria of location (urban/rural), gender, practice size (single handed/group) and length of time qualiô¡ed. A total sample size was generated using the 'ten plus three' method. Interviews were carried out in person, transcribed verbatim and analyzed using the framework analysis method. Results Nineteen GPs were interviewed. Core themes emerged and were analyzed. 1. GPs unanimously agreed that CIPC has been of beneô¡t in treating mild to moderate mental health disorders. 2. Suggested improvements to the service were made, including allowing GP visit card holders to avail of the service (n=10) and adolescents aged between 16 and 18 (n=5). 3. A majority (n=12) of GPs interviewed expressed the opinion that a combination of talk therapy and medication was associated with the best outcomes in treating mild to moderate mental health disorders. Conclusion CIPC seems to improve mental health services at a primary care level. While improvements can certainly be made to the service, GPs report positive patient outcomes and a reduction in psychiatric referrals for patients who can be suitably managed within the community.
Assuntos
Aconselhamento , Clínicos Gerais/psicologia , Transtornos Mentais/terapia , Serviços de Saúde Mental , Atenção Primária à Saúde , Serviços Comunitários de Saúde Mental , Feminino , Humanos , Entrevistas como Assunto , Masculino , Melhoria de Qualidade , Qualidade da Assistência à Saúde , Encaminhamento e Consulta/estatística & dados numéricos , Índice de Gravidade de Doença , Fatores de TempoRESUMO
BACKGROUND: The homeobox containing transcription factor MSX2 is a key regulator of embryonic development and has been implicated to have a role in breast and pancreatic cancer. METHODS: Using a selection of two- and three-dimensional in vitro assays and tissue microarrays (TMAs), the clinical and functional relevance of MSX2 in malignant melanoma was explored. A doxycyline-inducible over-expression system was applied to study the relevance of MSX2 in vitro. For TMA construction, tumour material from 218 melanoma patients was used. RESULTS: Ectopic expression of MSX2 resulted in the induction of apoptosis and reduced the invasive capacity of melanoma cells in three-dimensional culture. MSX2 over-expression was shown to affect several signalling pathways associated with cell invasion and survival. Downregulation of N-Cadherin, induction of p21 and inhibition of both BCL2 and Survivin were observed. Cytoplasmic MSX2 expression was found to correlate significantly with increased recurrence-free survival (P=0.008). Nuclear expression of MSX2 did not result in significant survival correlations, suggesting that the beneficial effect of MSX2 may be independent of its DNA binding activity. CONCLUSIONS: MSX2 may be an important regulator of melanoma cell invasion and survival. Cytoplasmic expression of the protein was identified as biomarker for good prognosis in malignant melanoma patients.
Assuntos
Proteínas de Homeodomínio/metabolismo , Melanoma/metabolismo , Melanoma/patologia , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Antígenos CD/metabolismo , Apoptose , Western Blotting , Caderinas/metabolismo , Ciclo Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Intervalo Livre de Doença , Regulação para Baixo , Eletroforese em Gel de Poliacrilamida , Imunofluorescência , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Proteínas Inibidoras de Apoptose/antagonistas & inibidores , Melanoma/genética , Análise Multivariada , Invasividade Neoplásica , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Análise Serial de Proteínas , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Transdução de Sinais , Neoplasias Cutâneas/genética , Esferoides Celulares , Análise de Sobrevida , Survivina , Regulação para CimaRESUMO
BACKGROUND: Lipoatrophy can complicate thymidine analogue nucleoside reverse transcriptase inhibitor (tNRTI)-based antiretroviral therapy (ART). Lipoatrophy may be less likely with ART including ritonavir-boosted lopinavir (LPV/r). Small, placebo-controlled studies found that uridine (in tNRTI recipients) and pravastatin improved HIV lipoatrophy over 12 weeks. Today, most patients with lipoatrophy receive non-tNRTI-based ART; the effect of uridine in such patients is unknown. METHODS: We performed a prospective, randomized trial in lipoatrophic adults with plasma HIV RNA<50 HIV-1 RNA copies/mL on tNRTI-sparing ART including LPV/r. Patients received uridine [36 g three times a day (tid) on 10 consecutive days per month; n=10], pravastatin [40 mg every night (nocte); n=12], uridine plus pravastatin (n=11) or neither (n=12) for 24 weeks. The primary endpoint was mean change in limb fat mass as assessed by dual-energy X-ray absorptiometry (DEXA). With 20 patients per intervention, the study had 80% power to detect a mean difference between a treatment and the control of 0.5 kg, assuming a standard deviation of 0.9 and an alpha threshold equal to 5% (two-sided). RESULTS: Of 45 participants (all men, with median age 49.5 years and median limb fat 2.6 kg), two discontinued pravastatin and one participant stopped both pravastatin and uridine. The difference between the mean changes in limb fat mass for uridine vs. no uridine was 0.03 kg [95% confidence interval (CI) -0.35, +0.28; P=0.79]. The respective difference for pravastatin was -0.03 kg (95% CI -0.29, +0.34; P=0.84). Pravastatin slightly decreased total cholesterol (0.44 mmol/L; P=0.099). Visceral adipose tissue measured by computed tomography did not change significantly. CONCLUSION: In this population and at the doses used, neither uridine nor pravastatin for 24 weeks significantly increased limb fat mass.
Assuntos
Antirretrovirais/uso terapêutico , Anticolesterolemiantes/uso terapêutico , Síndrome de Lipodistrofia Associada ao HIV/tratamento farmacológico , Pravastatina/uso terapêutico , Uridina/uso terapêutico , Absorciometria de Fóton , Adiposidade/efeitos dos fármacos , Adulto , Antirretrovirais/efeitos adversos , Anticolesterolemiantes/farmacocinética , Anticolesterolemiantes/farmacologia , Didesoxinucleosídeos/efeitos adversos , Quimioterapia Combinada , Extremidades , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Síndrome de Lipodistrofia Associada ao HIV/induzido quimicamente , Humanos , Lopinavir , Masculino , Pessoa de Meia-Idade , Pravastatina/farmacocinética , Pravastatina/farmacologia , Pirimidinonas/uso terapêutico , Inibidores da Transcriptase Reversa/efeitos adversos , Ritonavir/uso terapêutico , Uridina/farmacocinética , Uridina/farmacologiaRESUMO
INTRODUCTION: The aim of this study was to determine the trends in national practice regarding total hip arthroplasty compared with hemiarthroplasty in fractured neck of femur between 2010 and 2016. MATERIALS AND METHODS: A retrospective review was conducted of NHS Digital data (England) between 2010 and 2016. 'Emergency' neck of femur fracture admissions, hemiarthroplasties and total hip arthroplasties were included. Elective total hip arthroplasties, revisions and prostheses relocations were excluded. Annual percentages for each operation were calculated. Trends were tabulated and displayed graphically for analysis. RESULTS: The total number of emergency neck of femur diagnoses was 257,789. Total hip arthroplasty was performed in 2217, 2737, 3305, 3686, 3670 and 3825 patients and hemiarthroplasty was performed in 21,335, 21,744, 21,115, 21,798, 21,804 and 22,163 patients for each year between 2011 and 2016, respectively. The rate of change for total hip arthroplasty slowed from 24.54% increase/year (2011-2013) to 5.24% increase/year (2013-2016). Uncemented arthroplasties decreased over the same time period. DISCUSSION: Increasing numbers of total hip arthroplasties are conducted for hip fractures; however, this trend has slowed since 2013. Possible explanations include all eligible fractures being treated with total hip arthroplasty, trauma surgeon preference for hemiarthroplasty due to lower surgical specialism or publication of individual surgeon data (National Joint Registry) which may lead to surgeons favouring hemiarthroplasties which have a lower complication rate compared to elective total hip arthroplasties.
Assuntos
Artroplastia de Quadril/tendências , Fraturas do Colo Femoral/cirurgia , Hemiartroplastia/tendências , Padrões de Prática Médica/tendências , Utilização de Procedimentos e Técnicas/tendências , Inglaterra , Humanos , Sistema de Registros , Estudos RetrospectivosRESUMO
We prospectively studied the continuous function and complication rates of 286 central venous catheters consecutively placed in 264 children and young adults at a single institution over a 19-month period (median follow-up, 376 days). Externalized catheters (91 Hickman [H], 113 Broviac [B]) and implantable ports (n = 82) were compared for complications, including infection and thrombosis. The most frequent major complication of all catheters was infection, although the rates of infection varied with the duration of catheter use and were generally lower than reported by others. Overall, when catheter failures (removal) for infection, obstruction, or dislodgement were considered, ports had a significantly longer failure-free duration of use (P = .0024) than did externalized catheters. Likewise, ports had a significantly longer infection-free (P less than .01) duration of use than H and B catheters. However, differences in patient age and clinical characteristics among the three catheter groups may have affected the outcome. In analysis of pairs matched for diagnosis, therapy, and age, ports had lower infection rates than did B catheters after 100 days (P = .053). This difference became significant at 400 days of catheter use (P = .029). Although there was a trend toward lower rates of infections for ports v H catheters, this difference was not significant. In view of our results in matched pairs, selection of catheter type based on clinical characteristics and patient preferences remains a reasonable therapeutic approach despite the apparent advantages of ports. The superiority of ports for long-term use (greater than 100 days) needs to be confirmed in a large randomized clinical trial.
Assuntos
Cateterismo Venoso Central/instrumentação , Cateteres de Demora/efeitos adversos , Neoplasias/terapia , Próteses e Implantes/efeitos adversos , Adolescente , Adulto , Cateterismo Venoso Central/efeitos adversos , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Estudos Prospectivos , Sepse/etiologiaRESUMO
The clinical significance of pleural effusion was assessed in 24 children with unresectable abdominal small non-cleaved cell lymphoma (St. Jude Stage III). Patients were consecutively enrolled and treated on a regimen including high dose fractionated cyclophosphamide and co-ordinated high dose methotrexate and cytarabine. The overall results were excellent, with 20 of 24 patients alive and event-free at a median follow-up of 4 years. Only one of the patients who lacked pleural effusion has relapsed (testicular), even though many had massive disease. In contrast, three of seven patients with pleural effusion have failed treatment (p = 0.02) and subsequently died. Two measures of tumor burden, serum lactic dehydrogenase and, in a subset of patients, interleukin-2-receptor levels, were significantly higher in patients with pleural effusion (p = 0.002 and p = 0.05, respectively). These findings suggest that unresectable abdominal small non-cleaved cell lymphoma associated with pleural effusion should be up-staged and that these patients should receive more intensive chemotherapy.
Assuntos
Neoplasias Abdominais/tratamento farmacológico , Linfoma não Hodgkin/tratamento farmacológico , Derrame Pleural/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , L-Lactato Desidrogenase/sangue , Linfoma não Hodgkin/patologia , Masculino , Estadiamento de Neoplasias , Receptores de Interleucina-2/sangueRESUMO
OBJECTIVE/HYPOTHESIS: A cone-beam CT (CBCT) imaging system based on a mobile C-arm (Siemens PowerMobil) incorporating a high-performance flat-panel detector (Varian PaxScan) has been developed in our laboratory. We hypothesize that intraoperative C-arm CBCT provides image quality and guidance performance sufficient to assist surgical approach to the frontal recess. STUDY DESIGN: A preclinical prospective study was conducted using six cadaver heads to assess the performance characteristics and the potential clinical utility of this imaging system. METHODS: The mobile C-arm was employed for intraoperative CBCT guidance of the endoscopic approach to twelve frontal recesses. RESULTS: The imaging system is capable of sub-mm 3D spatial resolution with bone and soft-tissue visibility and a field of view sufficient for guidance of head and neck surgery. The system can generate intraoperative, volumetric CT images rapidly with an acceptably low radiation exposure to the patient and with image quality sufficient for most surgical tasks. Moreover, the system is portable and compatible with the surgical setup, providing excellent access to the patient. Finally, the accuracy of the system is not bound to a registration process. CONCLUSIONS: The ability to create updated images as surgery progresses introduces the concept of 'near-real-time' CT guidance for head and neck surgery. We found that the use of CBCT increased surgical confidence in accessing the frontal recess, resolved ambiguities with anatomical variations, and provided valuable teaching information to surgeons in training in both preoperative planning and correlation between tri-planar CT scans and intraoperative endoscopic findings.
Assuntos
Endoscopia/métodos , Osso Frontal/cirurgia , Seio Frontal/cirurgia , Cirurgia Assistida por Computador/instrumentação , Tomografia Computadorizada por Raios X , Cadáver , Desenho de Equipamento , Osso Frontal/diagnóstico por imagem , Seio Frontal/diagnóstico por imagem , Humanos , Técnicas In Vitro , Estudos Prospectivos , Reprodutibilidade dos TestesRESUMO
Phospho-tyrosine levels are increased in melanoma, apparently consistent with reports of elevated protein tyrosine kinase activity. Some protein tyrosine kinases are encoded by oncogenes and have been implicated in melanoma genesis. Decreased protein tyrosine phosphatase activity may also increase phospho-tyrosine. Protein tyrosine phosphatase genes are candidate tumor suppressors and loss of expression may contribute to melanoma genesis. Here we survey protein tyrosine phosphatase expression in pigment cells. Protein tyrosine phosphatase genes were cloned by reverse transcriptase polymerase chain reaction using degenerate primers based upon conserved sequences within the phosphatase catalytic domain. Reaction products were cloned and sequenced: 118 and 113 partial protein tyrosine phosphatase products were isolated from normal melanocytes and melanoma cells, respectively. Northern blotting analysis was used to study expression of 15 protein tyrosine phosphatase genes. Expression of PTP-kappa and PTP-pi was absent or downregulated in more than 20% of melanoma cell lines and in some unmanipulated melanoma biopsies. These closely related enzymes are members of the 2B receptor protein tyrosine phosphatase family previously implicated in contact inhibition. Loss of protein tyrosine phosphatase expression may contribute to the abnormal tyrosine phosphorylation seen in melanoma; these genes are candidate tumor suppressors.
Assuntos
Regulação para Baixo , Expressão Gênica , Melanoma/genética , Proteínas Tirosina Fosfatases/genética , Northern Blotting , Southern Blotting , Células Cultivadas , Clonagem Molecular , Humanos , Immunoblotting , Melanócitos/enzimologia , Melanoma/enzimologia , Melanoma/patologia , Proteínas Tirosina Fosfatases Classe 2 Semelhantes a Receptores , Valores de Referência , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
A derivative of phencyclidine (PCP, 1 in fig. 1) bearing an isothiocyanate moiety on the meta position of the aromatic ring (Metaphit, 3 in fig. 1) has been synthesized and identified as a rapid and specific site-directed acylating agent of the [3H]phencyclidine binding site in rat brain homogenates. The percentage of sites irreversibly inactivated by Metaphit was found to be the same in the hippocampus and striatum and the remaining sites were unaffected by Metaphit treatment under any conditions, suggesting that at least two distinct binding sites are present. An isomeric isothiocyanate derivative did not irreversibly inhibit [3H]phencyclidine receptors, indicating structural specificity for Metaphit in the inhibition of these receptors. The availability of Metaphit should greatly facilitate study of the structure and function of the phencyclidine receptors.
Assuntos
Encéfalo/metabolismo , Fenciclidina/análogos & derivados , Receptores de Neurotransmissores/metabolismo , Acilação , Animais , Corpo Estriado/metabolismo , Hipocampo/metabolismo , Masculino , Fenciclidina/metabolismo , Fenciclidina/farmacologia , Ratos , Ratos Endogâmicos , Receptores de Neurotransmissores/efeitos dos fármacos , Receptores da Fenciclidina , Relação Estrutura-AtividadeRESUMO
We investigated the directional nature of the bulk tolerance and hydrophobic binding in the aromatic ring binding region of the active site of norepinephrine N-methyltransferase (NMT) by comparing the substrate and inhibitor activities of m- and p-phenyl-substituted derivatives of amphetamine, phenylethanolamine, and alpha-methylbenzylamine. The para isomers of amphetamine and phenylethanolamine displayed significantly greater activities as inhibitor and substrate, respectively, than the meta isomers, which indicated that the bulk tolerance was near the para position. For benzylamines, the greatest inhibitory activity was observed for the meta isomer, demonstrating a significant difference in the binding requirements for phenylethylamines and benzylamines. These findings are consistent with a two-state model for the NMT active site that has been proposed elsewhere to account for its ability to bind both benzylamines and phenylethylamines in a fully extended side-chain conformation.
Assuntos
Feniletanolamina N-Metiltransferase/isolamento & purificação , Anfetaminas/farmacologia , Benzilaminas/farmacologia , Sítios de Ligação , Fenômenos Químicos , Química , Cinética , Fenetilaminas/farmacologiaRESUMO
In an effort to determine the surface appearance of the hydrophobic ring binding region of the norepinephrine N-methyltransferase active site, we employed some trans-decalin analogues of 1-(aminomethyl)cycloundecanol (1), a potent NMT inhibitor. These analogues [axial and equatorial 2-(aminomethyl)-trans-2-decalol, 2 and 3] closely resemble a low energy "crown" conformation of 1. Both compounds were as potent as 1 at inhibiting NMT (Ki = 3.6, 5.6, and 3.8 microM for 1, 2, and 3, respectively), indicating that this conformation is most likely adopted within the active site in order to optimize contact with a flat hydrophobic area. None of the compounds showed significant substrate activity for NMT, a fact that is consistent with our proposed active site binding model.
Assuntos
Amino Álcoois/síntese química , Feniletanolamina N-Metiltransferase/antagonistas & inibidores , Glândulas Suprarrenais/enzimologia , Amino Álcoois/farmacologia , Animais , Bovinos , Fenômenos Químicos , Química , Técnicas In Vitro , Cinética , Fenetilaminas/metabolismo , Especificidade por SubstratoRESUMO
A series of omega-substituted analogues of amphetamine and alpha-methylbenzylamine were prepared and evaluated as inhibitors of norepinephrine N-methyltransferase (NMT). These included several alkyl side chain extended analogues (1-5), as well as the terminally hydroxylated derivatives phenylalanol (6a) and phenylglycinol (7a). None of the alkyl-substituted derivatives displayed appreciable activity as inhibitors; however, the hydroxylated analogues were up to twofold more potent than the parent compounds. The positive contribution of the side-chain hydroxy suggests that the terminal methyl group of the lead compounds is situated close to a hydrophilic area or hydrogen bonding functional group within the active site.
Assuntos
Aminas/metabolismo , Anfetaminas/metabolismo , Benzilaminas/metabolismo , Fenetilaminas/metabolismo , Feniletanolamina N-Metiltransferase/metabolismo , Sítios de Ligação , Catálise , Relação Estrutura-AtividadeRESUMO
Brown oxidation of cis-bicyclo[3.1.0]hexan-3-ol afforded bicyclo[3.1.0]hexan-3-one in 98% yield. Treatment of this ketone with either phenyllithium or phenylamagnesium bromide in ether at room temperature followed by solvolysis of the resulting alcohol in a mixture of trifluoroacetic acid, sodium azide, and chloroform gave a mixture of cis- and trans-3-azido-3-phenylbicyclo[3.1.0]hexanes. LAH reduction of this crude mixture of azides afforded a 1:3.5 mixture of cis- and trans-3-phenyl-3-bicyclo[3.1.0]hexylamine, respectively, in 51% overall yield from the alcohol. Separation of the mixture of amines by column chromatography followed by cyclization of each by heating at 60 degrees C in DMF solution with 1 equiv of 1,5-dibromopentane furnished the two conformationally restrained analogues of phencyclidine (PCP), cis- and trans-3-phenyl-3-piperidinylbicyclo[3.1.0]hexane (1 and 2, respectively), in high yield. Configurations were assigned on the basis of an X-ray crystallographic analysis of the cis isomer (1). Bond lengths and angles are similar to those found in PCP and its derivatives. Binding to PCP receptors and sigma sites as well as behavioral effects of 1 and 2 in rats was determined relative to PCP. In displacement of specifically bound [3H]TCP (1-[1-(2-thienyl)cyclohexyl]piperidine) from PCP receptors, 1 and 2 were nearly equipotent and about one-seventh as potent as PCP. These compounds were about one-fifth as potent as PCP in displacing [3H]-(+)-SKF 10,047 from its binding site. Calculation of the ED50 values of 1 and 2 for stereotyped behavior and ataxia indicated that they were about equipotent, and 2-3-fold less active than PCP.
Assuntos
Fenciclidina/análogos & derivados , Animais , Ataxia/induzido quimicamente , Fenômenos Químicos , Química , Modelos Moleculares , Fenciclidina/síntese química , Fenciclidina/farmacologia , Ratos , Ratos Endogâmicos , Estereoisomerismo , Comportamento Estereotipado/efeitos dos fármacos , Relação Estrutura-AtividadeRESUMO
Some nonaromatic analogues of amphetamine and alpha-methylbenzylamine were prepared and evaluated as competitive inhibitors of norepinephrine N-methyltransferase (NMT). All of the nonaromatic analogues were significantly more active than their aromatic counterparts [Ki for amphetamine = 740 microM; Ki for 1-cyclooctyl-2-aminopropane = 86 microM]. In order to determine if the aliphatic ring of these analogues bound to the same binding site as the phenyl ring of amphetamine and alpha-methylbenzylamine, the stereoselectivity of NMT toward the different compounds was determined. Stereochemical requirements for aromatic and nonaromatic inhibitors were similar (in all cases the S isomer was more potent at inhibiting NMT). The stereochemical preference expressed for phenylethanolamine substrates and corresponding nonaromatic analogues was also found to be the same; however, as the lipophilicity of the nonaromatic ethanolamine analogues was increased, a loss in both stereoselectivity and substrate activity occurred. The results presented here are consistent with an aromatic ring binding site that is part of, or bordered by, a large hydrophobic area. The larger, more hydrophobic nonaromatic phenylethanolamine derivatives are drawn into the hydrophobic area, which reduces side-chain hydroxy interactions necessary for substrate activity.
Assuntos
Feniletanolamina N-Metiltransferase/metabolismo , Simpatomiméticos/farmacologia , Anfetaminas/farmacologia , Fenômenos Químicos , Química , Cinética , Norepinefrina/metabolismo , Feniletanolamina N-Metiltransferase/antagonistas & inibidores , EstereoisomerismoRESUMO
8-Chlorodibenz[b,f][1,4]oxazepine-10(11H)-carboxylic acid, 2-acetylhydrazide (1, SC-19220) has been previously reported by us and others to be a PGE2 antagonist selective for the EP1 receptor subtype with antinociceptive activities. Analogs of SC-19220, in which the acetyl moiety has been replaced with pyridylpropionyl groups and their homologs, have been synthesized as illustrated by compounds 13 and 29. These and other members of this series have been shown to be efficacious analgesics and PGE2 antagonists of the EP1 subtype. This report discusses the structure activity relationships within this series.
Assuntos
Analgésicos/síntese química , Analgésicos/farmacologia , Ácido Dibenzo(b,f)(1,4)oxazepina-10(11H)-carboxílico, 8-cloro-, 2-acetilidrazida/análogos & derivados , Dibenzoxazepinas/síntese química , Dibenzoxazepinas/farmacologia , Dinoprostona/antagonistas & inibidores , Animais , Fenômenos Químicos , Físico-Química , Cobaias , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos , Nociceptores/efeitos dos fármacos , Solubilidade , Relação Estrutura-Atividade , ÁguaRESUMO
PNQX (1,4,7,8,9,10-hexahydro-9-methyl-6-nitropyrido[3, 4-f]quinoxaline-2,3-dione) is a potent AMPA (IC50 = 0.063 microM) and GlyN (IC50 = 0.37 microM) receptor antagonist that was developed in our laboratories. While possessing a desirable in vitro and in vivo activity profile, this compound suffers from low aqueous solubility. In an effort to improve its potency and physical properties, we have designed and synthesized novel ring-opened analogues 4, 6, 9, and 11. Modeling analyses demonstrated that, while the 5-substituent in these analogues was forced to adopt an out-of-plane conformation due to steric contacts with neighboring substituents, the overall structure retained a good fit to a previously described AMPA pharmacophore model. This nonplanar orientation may lessen efficient packing in the solid state, compared to PNQX, leading to increased water solubility. Indeed, several nonplanar analogues containing appropriate functionalities, for example, the sarcosine analogue 9, were found to retain AMPA (IC50 = 0.14 microM) and GlyN (IC50 = 0.47 microM) receptor affinity and possess improved aqueous solubility compared to PNQX. The synthesis and the SAR of these compounds are discussed.
Assuntos
Antagonistas de Aminoácidos Excitatórios/síntese química , Glicina/análogos & derivados , Quinoxalinas/síntese química , Receptores de AMPA/antagonistas & inibidores , Receptores de Glicina/antagonistas & inibidores , Animais , Anticonvulsivantes/síntese química , Anticonvulsivantes/química , Anticonvulsivantes/metabolismo , Anticonvulsivantes/farmacologia , Ligação Competitiva , Córtex Cerebral/metabolismo , Desenho de Fármacos , Antagonistas de Aminoácidos Excitatórios/química , Antagonistas de Aminoácidos Excitatórios/metabolismo , Antagonistas de Aminoácidos Excitatórios/farmacologia , Glicina/síntese química , Glicina/química , Glicina/metabolismo , Glicina/farmacologia , Técnicas In Vitro , Masculino , Camundongos , Modelos Moleculares , Quinoxalinas/química , Quinoxalinas/metabolismo , Quinoxalinas/farmacologia , Ratos , Receptores de AMPA/metabolismo , Receptores de Glicina/metabolismo , Solubilidade , Sinaptossomos/metabolismoRESUMO
In this article, the rationale for the design, synthesis, and biological evaluation of a series of N-type voltage-sensitive calcium channel (VSCC) blockers is described. N-Type VSCC blockers, such as ziconotide, have shown utility in several models of stroke and pain. Modification of the previously reported lead, 1a, led to several 4-(4-benzyloxylphenyl)piperidine structures with potent in vitro and in vivo activities. In this series, the most interesting compound, (S)-2-amino-1-{4-[(4-benzyloxy-phenyl)-(3-methyl-but-2-enyl)-amino]-p iperidin-1-yl}-4-methyl-pentan-1-one (11), blocked N-type calcium channels (IC(50) = 0.67 microM in the IMR32 assay) and was efficacious in the audiogenic DBA/2 seizure mouse model (ED(50) = 6 mg/kg, iv) as well as the antiwrithing model (ED(50) = 6 mg/kg, iv). Whole-cell voltage-clamp electrophysiology experiments demonstrated that compound 11 blocked N-type Ca(2+) channels and Na(+) channels in superior cervical ganglion neurons at similar concentrations. Compound 11, which showed superior in vivo efficacy, stands out as an interesting lead for further development of neurotherapeutic agents in this series.
Assuntos
Analgésicos não Narcóticos/síntese química , Anticonvulsivantes/síntese química , Bloqueadores dos Canais de Cálcio/síntese química , Neurônios/metabolismo , Piperidinas/síntese química , Estimulação Acústica , Analgésicos não Narcóticos/química , Analgésicos não Narcóticos/farmacocinética , Analgésicos não Narcóticos/farmacologia , Animais , Anticonvulsivantes/química , Anticonvulsivantes/farmacocinética , Anticonvulsivantes/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/farmacocinética , Bloqueadores dos Canais de Cálcio/farmacologia , Linhagem Celular , Frequência Cardíaca/efeitos dos fármacos , Humanos , Técnicas In Vitro , Ativação do Canal Iônico , Masculino , Camundongos , Camundongos Endogâmicos DBA , Microssomos Hepáticos/metabolismo , Medição da Dor , Técnicas de Patch-Clamp , Piperidinas/química , Piperidinas/farmacocinética , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Convulsões/tratamento farmacológicoRESUMO
The prevalence of, and clinical risk factors associated with, vancomycin-resistant enterococcal colonization were investigated in patients suspected of having Clostridium difficile infection. Stools submitted for C difficile cytotoxin testing were screened for vancomycin-resistant enterococci (VRE). Isolates were speciated and characterized further by antibiotic susceptibility testing, DNA fingerprinting, and DNA:DNA hybridization for detection of specific vancomycin resistance genes. Of the 79 evaluable patients identified during a 3-month period, 16.5% were VRE-positive. The VRE isolates were genetically heterogeneous, although all carried the vanA gene. DNA fingerprinting data suggest that patient-to-patient transmission occurred, implicating colonized patients as potential reservoirs for VRE transmission. A positive C difficile cytotoxin assay and diabetes mellitus were the only identifiable risk factors associated with VRE colonization. Patients at risk for C difficile infection therefore may serve as reservoirs for VRE.