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1.
Epidemiol Infect ; 148: e194, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32854791

RESUMO

We report key learning from the public health management of the first two confirmed cases of COVID-19 identified in the UK. The first case imported, and the second associated with probable person-to-person transmission within the UK. Contact tracing was complex and fast-moving. Potential exposures for both cases were reviewed, and 52 contacts were identified. No further confirmed COVID-19 cases have been linked epidemiologically to these two cases. As steps are made to enhance contact tracing across the UK, the lessons learned from earlier contact tracing during the country's containment phase are particularly important and timely.


Assuntos
Busca de Comunicante , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/terapia , Pneumonia Viral/epidemiologia , Pneumonia Viral/terapia , Betacoronavirus , COVID-19 , Humanos , Pandemias , Administração em Saúde Pública , SARS-CoV-2 , Reino Unido/epidemiologia
2.
Br J Cancer ; 121(3): 282, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31217480

RESUMO

A correction to this paper has been published and can be accessed via a link at the top of the paper.

3.
Epidemiol Infect ; 147: e175, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-31063115

RESUMO

Declining mortality following invasive pneumococcal disease (IPD) has been observed concurrent with a reduced incidence due to effective pneumococcal conjugate vaccines. However, with IPD now increasing due to serotype replacement, we undertook a statistical analysis to estimate the trend in all-cause 30-day case fatality rate (CFR) in the North East of England (NEE) following IPD. Clinical, microbiological and demographic data were obtained for all laboratory-confirmed IPD cases (April 2006-March 2016) and the adjusted association between CFR and epidemiological year estimated using logistic regression. Of the 2510 episodes of IPD included in the analysis, 486 died within 30 days of IPD (CFR 19%). Increasing age, male sex, a diagnosis of septicaemia, being in ⩾1 clinical risk groups, alcohol abuse and individual serotypes were independently associated with increased CFR. A significant decline in CFR over time was observed following adjustment for these significant predictors (adjusted odds ratio 0.93, 95% confidence interval 0.89-0.98; P = 0.003). A small but significant decline in 30-day all-cause CFR following IPD has been observed in the NEE. Nonetheless, certain population groups remain at increased risk of dying following IPD. Despite the introduction of effective vaccines, further strategies to reduce the ongoing burden of mortality from IPD are needed.


Assuntos
Infecções Pneumocócicas/mortalidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Inglaterra/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Mortalidade/tendências , Infecções Pneumocócicas/microbiologia , Adulto Jovem
4.
J Public Health (Oxf) ; 41(4): 700-706, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-30351415

RESUMO

BACKGROUND: A large proportion of the 200 000 HCV-infected individuals in the UK are undiagnosed or lost to follow-up. Engaging known infected individuals in treatment is essential for elimination. METHODS: Using PHE surveillance data and HCV treatment registers from North East of England (NE) treatment centres for 1997-2016, we estimated the number of HCV cases not linked to treatment and the proportion with active infection. We compared distances of treated and untreated cases to treatment services, and assessed the effect of expanding HCV treatment into existing drug and alcohol treatment centres in the NEE on treatment accessibility. RESULTS: The odds of being treated was associated with distance to treatment services. Confirmatory results for ~50% were not reported to PHE NE. Overall, 3385 patients reported to PHE NE had no record of treatment; we estimated 1621 of these may have been lost to follow-up after confirmation of active infection. CONCLUSIONS: Poor access to healthcare services may contribute to under-diagnosis or loss to follow-up. Expanding HCV treatment delivery into NEE drug and alcohol treatment centres would improve the accessibility of treatment services to people infected with/at risk of HCV. This may increase the proportion receiving treatment and support progress towards elimination.


Assuntos
Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Hepatite C/terapia , Perda de Seguimento , Inglaterra , Humanos , Modelos Logísticos , Análise Espacial
5.
Ann Oncol ; 28(10): 2367-2376, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28945834

RESUMO

Clinically relevant features in patients with systemic mastocytosis (SM) include the cosmetic burden of lesional skin, mediator-related symptoms, and organ damage resulting from mast cell (MC) infiltration in advanced forms of SM. Regardless of the SM variant, expansion of neoplastic MC in the skin and other organs is triggered by mutant forms of KIT, the most prevalent being D816V. Activation of MC with subsequent release of chemical mediators is often caused by IgE-dependent mechanisms in these patients. Midostaurin, also known as PKC412, blocks the kinase activity of wild-type KIT and KIT D816V, counteracts KIT-dependent growth of neoplastic MC, and inhibits IgE-dependent mediator secretion. Based on this activity-profile, the drug has been used for treatment of patients with advanced SM. Indeed, encouraging results have been obtained with the drug in a recent multi-center phase II trial in patients with advanced SM, with an overall response rate of 60% and a substantial decrease in the burden of neoplastic MC in various organs. Moreover, midostaurin improved the overall survival and relapse-free survival in patients with advanced SM compared with historical controls. In addition, midostaurin was found to improve mediator-related symptoms and quality of life, suggesting that the drug may also be useful in patients with indolent SM suffering from mediator-related symptoms resistant to conventional therapies or those with MC activation syndromes. Ongoing and future studies will determine the actual value of midostaurin-induced MC depletion and MC deactivation in these additional indications.


Assuntos
Mastócitos/efeitos dos fármacos , Mastocitose Sistêmica/tratamento farmacológico , Mastocitose Sistêmica/patologia , Estaurosporina/análogos & derivados , Antineoplásicos/uso terapêutico , Ensaios Clínicos Fase II como Assunto , Resistencia a Medicamentos Antineoplásicos , Humanos , Mastócitos/imunologia , Mastócitos/patologia , Mastocitose Sistêmica/imunologia , Estudos Multicêntricos como Assunto , Estaurosporina/uso terapêutico
6.
Intern Med J ; 45(8): 843-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25872126

RESUMO

BACKGROUND/AIM: The Delay Future End Stage Nephropathy due to Diabetes study was a randomised controlled trial of Maori and Pacific patients with advanced diabetic nephropathy, comparing a community-based model of care with usual care. The intervention group achieved lower blood pressure (BP), proteinuria and less end-organ damage. After the intervention ended, all patients reverted to usual care, and were followed to review the sustainability of the intervention. METHODS: A retrospective observation of 65 patients (aged 47-75 years) with type 2 diabetes, hypertension, chronic kidney disease 3/4 and proteinuria (>0.5 g/day) previously randomised to intervention/community care or usual care for 11-21 months. Follow up thereafter was until death, end-stage renal disease (ESRD) (estimated glomerular filtration rate (eGFR) ≤ 10 mL/min/1.73 m(2) )/dialysis or 1 February 2014. Primary end-points were death and ESRD/dialysis. Secondary outcomes were annualised glomerular filtration rate decline, non-fatal vascular events and hospitalisations. RESULTS: Median (interquartile ranges (IQR)) post-trial follow up was 49 (21-81) months and similar in both groups. The median (IQR) eGFR decline was -3.1 (-5.5, -2.3) and -5.5 (-7.1, -3.0) mL/min/year in the intervention and usual care groups respectively (P = 0.11). Similar number of deaths, renal and vascular events were observed in both groups. At the end of follow up, the number of prescribed antihypertensive medications was similar (3.4 ± 1.0 vs 3.3 ± 1.4; P = 0.78). There were fewer median (IQR) hospital days (8 (3, 18) vs 15.5 (6, 49) days, P = 0.03) in the intervention group. CONCLUSIONS: Short-term intensive BP control followed by usual care did not translate into reduction in long-term mortality or ESRD rates, but was associated with reduced hospitalisations.


Assuntos
Serviços de Saúde Comunitária/organização & administração , Diabetes Mellitus Tipo 2/terapia , Falência Renal Crônica/prevenção & controle , Modelos Organizacionais , Havaiano Nativo ou Outro Ilhéu do Pacífico/etnologia , Insuficiência Renal Crônica/terapia , Idoso , Diabetes Mellitus Tipo 2/etnologia , Diabetes Mellitus Tipo 2/mortalidade , Seguimentos , Hospitalização/estatística & dados numéricos , Humanos , Hipertensão/prevenção & controle , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Proteinúria/prevenção & controle , Insuficiência Renal Crônica/etnologia , Insuficiência Renal Crônica/mortalidade , Estudos Retrospectivos , Resultado do Tratamento
7.
J Cell Biol ; 62(3): 695-706, 1974 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-4368324

RESUMO

Extracts of purified mitochondria from adult rabbit liver and kidney have been prepared by lysis with Triton X-100. Such extracts contain deoxyribonuclease activity demonstrable at alkaline pH. Studies utilizing the effects of substrate variation, differing ionic strength, nucleoside di- and triphosphates, and SH-group inhibitors reveal the existence of at least five distinguishable deoxyribonuclease activities in these extracts. Assay of lysosomal and mitochondrial enzyme markers indicates no significant lysosomal contamination of the mitochondrial extracts. Further studies also suggest that the alkaline deoxyribonuclease activity is specifically located in or in association with mitochondria.


Assuntos
Desoxirribonucleases/metabolismo , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias/enzimologia , Fosfatase Ácida/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Benzenossulfonatos/farmacologia , Centrifugação com Gradiente de Concentração , DNA/metabolismo , Difosfatos/farmacologia , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Concentração de Íons de Hidrogênio , Rim/citologia , Lisossomos/enzimologia , Mercúrio/farmacologia , Compostos Organometálicos/farmacologia , Cloreto de Potássio/farmacologia , Proteínas/metabolismo , Coelhos , Trítio
8.
Vet Comp Orthop Traumatol ; 22(4): 328-31, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19597637

RESUMO

Fragmented medial coronoid process (FMCP) is a disease process that has not previously been reported in toy-breed dogs. This report describes a presumptive case of FMCP in a 14-month-old Chihuahua that was presented for evaluation approximately four weeks following acute onset of moderate lameness in the left forelimb. Definitive diagnosis of a fragmented medial coronoid process was based upon computed tomography (CT) scan. A CT scan also demonstrated moderate joint incongruity in the affected elbow. Surgical removal of the fragment and subtotal coronoidectomy were performed via a medial arthrotomy. An ulnar ostectomy was also performed to address joint incongruity. Histology of specimens removed at surgery did not demonstrate evidence of microdamage as characteristic of FMCP in large breed dogs, and instead, suggested that the fracture was acute and traumatic in nature. Rapid return to function was observed following surgery.


Assuntos
Doenças do Cão/cirurgia , Membro Anterior/lesões , Fraturas Ósseas/veterinária , Animais , Cães , Feminino , Fraturas Ósseas/patologia , Fraturas Ósseas/cirurgia , Articulações/lesões
9.
Vet Immunol Immunopathol ; 119(3-4): 214-21, 2007 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-17629954

RESUMO

Dysregulation of immune responses within joints plays an important role in development of inflammatory arthritis. We determined expression of a panel of immune response and matrix turnover genes in synovial fluid collected from a group of dogs with stifle oligoarthritis and associated degenerative cranial cruciate ligament (CCL) rupture (n=27). We also studied synovial fluid gene expression in dogs affected with other forms of degenerative arthritis (n=9) and in the stifle joint of healthy dogs with intact CCL (n=14). After collection, synovial cells were pelleted and RNA was isolated. Relative expression of cathepsin K, cathepsin S, tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-9 (MMP-9), invariant chain (li), toll-like receptor-2 (TLR-2), and TLR-9 was determined using real-time quantitative RT-PCR. Data were normalized to peripheral blood mononuclear cells (PBMC) as an internal control. Relative expression of cathepsin K, MMP-9, TRAP, and li was increased in the stifle synovial fluid of dogs with oligoarthritis, when compared with the stifles of healthy dogs (P<0.05). In contrast, relative expression of all of the genes-of-interest in synovial fluid from joints affected with other forms of arthritis was not significantly different from the stifles of healthy dogs. TRAP expression was also significantly increased in the stifle joints of dogs with oligoarthritis, when compared to joint expression of TRAP in dogs with other forms of degenerative arthritis (P<0.05). In the dogs with stifle oligoarthritis, expression of both matrix turnover and immune response genes was increased in stifle synovial fluid, when compared with the internal PBMC control, whereas in healthy dogs and dogs with other forms of arthritis, only expression of matrix turnover genes was increased in synovial fluid, when compared with the internal PBMC control (P<0.05). Taken together, these findings suggest that antigen-specific immune responses within the stifle joint may be involved in the pathogenesis of persistent synovitis and associated joint degradation in dogs with oligoarthritis and degenerative CCL rupture.


Assuntos
Lesões do Ligamento Cruzado Anterior , Artrite/veterinária , Doenças do Cão/genética , Doenças do Cão/imunologia , Antígenos de Histocompatibilidade/genética , Ruptura/veterinária , Joelho de Quadrúpedes/metabolismo , Animais , Ligamento Cruzado Anterior/metabolismo , Artrite/genética , Artrite/imunologia , Cães , Feminino , Regulação da Expressão Gênica , Antígenos de Histocompatibilidade/metabolismo , Masculino , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ruptura/genética , Ruptura/imunologia , Joelho de Quadrúpedes/imunologia
10.
Med Hypotheses ; 66(4): 784-92, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16337748

RESUMO

Proteins that are highly conserved throughout evolution are presumed to have critical roles in the survival of the species. The two major acute phase proteins, C-reactive protein (CRP) and serum amyloid A (SAA) increase up to 1000-fold during inflammation. Both proteins have been highly conserved phylogenetically for at least the last 500 million years. Thus far the physiologic role and the evolutionary significance of each remains uncertain and their potential interactions have been totally ignored despite a vast and accelerating scientific literature on the involvement of each in human disease. CRP is known to bind to phosphocholine in dead eukaryote and some live bacterial cell walls suggesting that CRP facilitates the phagocytosis of fragmented or intact dead cells and/or enhances host bacterial defenses. SAA has recently been shown to increase the rate of export of cholesterol of phagocytosed cell membranes from macrophages fourfold. We postulate that their combined physiological role is to facilitate the rapid endogenous recycling of cell membrane cholesterol and phospholipids during acute inflammation. CRP promotes efficient phagocytosis of dying cells by macrophages; SAA enhances the export of their free cholesterol/phospholipid for reuse in the membranes of the hundreds of billions of new cells required daily during acute inflammation and repair. The evolutionary conservation of these proteins in species from the horseshoe crab and echinoderms to humans suggests that the rapid endogenous recycling of cholesterol and phospholipids during the highly vulnerable period of acute inflammation is critical for their continual survival.


Assuntos
Proteína C-Reativa/fisiologia , Colesterol/metabolismo , Inflamação/imunologia , Proteína Amiloide A Sérica/fisiologia , Humanos , Macrófagos/imunologia , Fagocitose
11.
J Natl Cancer Inst ; 81(12): 935-8, 1989 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-2733037

RESUMO

Canine osteosarcoma is a spontaneous malignancy in dogs, characterized by micrometastasis to pulmonary and extrapulmonary tissues at the time of diagnosis. Standard treatment involves amputation of the affected leg, but median survival time is 3-4 months with death due to metastasis. A randomized double-blind trial was conducted to evaluate liposome-encapsulated muramyl tripeptide-phosphatidylethanolamine (liposome/MTP-PE) as a treatment for metastasis in dogs undergoing amputation for osteosarcoma. Fourteen dogs were treated with liposome/MTP-PE, and 13 were treated with empty liposomes. Median survival time was 222 days for dogs treated with liposome/MTP-PE, compared to 77 days for dogs treated with empty liposomes (P less than .002). In the liposome/MTP-PE-treated group there were still four dogs alive and free of metastasis at greater than 1 year post surgery. Treatment was well tolerated; no significant toxic effects were noted except for mild elevations in body temperature (1-2 degrees C) for 2-6 hours post injection.


Assuntos
Acetilmuramil-Alanil-Isoglutamina/análogos & derivados , Osteossarcoma/terapia , Fosfatidiletanolaminas/administração & dosagem , Acetilmuramil-Alanil-Isoglutamina/administração & dosagem , Amputação Cirúrgica , Animais , Temperatura Corporal/efeitos dos fármacos , Terapia Combinada , Doenças do Cão/terapia , Cães , Método Duplo-Cego , Portadores de Fármacos , Injeções Intravenosas , Lipossomos , Osteossarcoma/secundário , Osteossarcoma/veterinária
12.
Leukemia ; 30(2): 464-72, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26349526

RESUMO

Proteomic-based drug testing is an emerging approach to establish the clinical value and anti-neoplastic potential of multikinase inhibitors. The multikinase inhibitor midostaurin (PKC412) is a promising new agent used to treat patients with advanced systemic mastocytosis (SM). We examined the target interaction profiles and the mast cell (MC)-targeting effects of two pharmacologically relevant midostaurin metabolites, CGP52421 and CGP62221. All three compounds, midostaurin and the two metabolites, suppressed IgE-dependent histamine secretion in basophils and MC with reasonable IC(50) values. Midostaurin and CGP62221 also produced growth inhibition and dephosphorylation of KIT in the MC leukemia cell line HMC-1.2, whereas the second metabolite, CGP52421, which accumulates in vivo, showed no substantial effects. Chemical proteomic profiling and drug competition experiments revealed that midostaurin interacts with KIT and several additional kinase targets. The key downstream regulator FES was recognized by midostaurin and CGP62221, but not by CGP52421 in MC lysates, whereas the IgE receptor downstream target SYK was recognized by both metabolites. Together, our data show that the clinically relevant midostaurin metabolite CGP52421 inhibits IgE-dependent histamine release, but is a weak inhibitor of MC proliferation, which may have clinical implications and may explain why mediator-related symptoms improve in SM patients even when disease progression occurs.


Assuntos
Mastócitos/efeitos dos fármacos , Mastocitose/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Estaurosporina/análogos & derivados , Adulto , Idoso , Basófilos/efeitos dos fármacos , Basófilos/fisiologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Liberação de Histamina/efeitos dos fármacos , Humanos , Masculino , Mastócitos/fisiologia , Mastocitose/patologia , Pessoa de Meia-Idade , Proteínas Proto-Oncogênicas c-kit/metabolismo , Estaurosporina/farmacologia
13.
Biol Psychiatry ; 44(1): 47-51, 1998 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-9646882

RESUMO

BACKGROUND: Disturbances in central nervous system Na+, K+ adenosine triphosphatase (ATPase) activity have previously been proposed as being involved in the pathophysiology of bipolar mood disorder. METHODS: We have examined one particular alpha subunit of this enzyme for allelic association in a sample of 85 Irish bipolar patients and 85 matched controls. RESULTS: There was evidence for an overall allelic association between the disease and a dinucleotide polymorphism within the ATP1A3 gene (p = .022). Subjects were then analyzed on the basis of a number of criteria, and the significance of the association increased when cases were divided based on the nature of the first episode. Patients who presented with a depressive episode first showed a significant association (p = .001) with this polymorphism. CONCLUSIONS: The results presented here provide preliminary evidence of an association between bipolar disorder and an alpha subunit of Na+, K+ ATPase, the expression of which predominates in the brain.


Assuntos
Transtorno Bipolar/genética , ATPase Trocadora de Sódio-Potássio/genética , Adulto , Idoso , Alelos , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/fisiopatologia , Encéfalo/metabolismo , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Repetições de Dinucleotídeos/genética , Feminino , Expressão Gênica , Marcadores Genéticos , Humanos , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Polimorfismo Genético , ATPase Trocadora de Sódio-Potássio/biossíntese , ATPase Trocadora de Sódio-Potássio/fisiologia
14.
Biol Psychiatry ; 42(6): 486-94, 1997 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-9285084

RESUMO

Seven families, multiply affected by bipolar mood disorder, have been collected from the Irish population and have been genotyped with microsatellite markers from the pericentromeric region of chromosome 18, a region that has been implicated as a site for a susceptibility gene for this relative common psychiatric disorder. The families significantly excluded linkage of bipolar disorder to this region under various models. Although the data provided no evidence of linkage heterogeneity among families, the number of families investigated may be too small to exclude completely the possibility of linkage in a small number of families.


Assuntos
Transtorno Bipolar/genética , Cromossomos Humanos Par 18/fisiologia , Adulto , Transtorno Bipolar/psicologia , Feminino , Ligação Genética , Genótipo , Humanos , Irlanda , Masculino , Repetições de Microssatélites , Modelos Genéticos , Linhagem
15.
Eur J Cancer ; 38 Suppl 5: S19-27, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12528769

RESUMO

The understanding of the pathophysiology of a large number of cancer types provides a strategy to target cancer cells with minimal effect on normal cells. Protein phosphorylation and dephosphorylation play a pivotal role in intracellular signaling; to regulate signal transduction pathways, there are approximately 700 protein kinases and 100 protein phosphatases encoded within the human genome. In cancer, as well as in other proliferative diseases, unregulated cell proliferation, differentiation and survival frequently results from abnormal protein phosphorylation. Although it is often possible to identify a single kinase that plays a pivotal role in a given disease, the development of drugs based upon protein kinase inhibition has been hampered by unacceptable side effects resulting from a lack of target selectivity. With the growing understanding of the molecular biology of protein tyrosine kinases and the use of structural information, the design of potential drugs directed towards the bind adenosine triphosphate (ATP)-binding site of a single target has become possible. These advances have transferred emphasis away from the identification of potent kinase inhibitors and more towards issues of target selectivity, cellular efficacy, therapeutic effectiveness and tolerability. In this paper, the relationship between molecular biology and drug discovery methods, as utilized for the identification of anticancer drugs, will be illustrated.


Assuntos
Antineoplásicos/uso terapêutico , Inibidores Enzimáticos/uso terapêutico , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/tratamento farmacológico , Piperazinas/uso terapêutico , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirimidinas/uso terapêutico , Trifosfato de Adenosina/metabolismo , Antineoplásicos/química , Benzamidas , Comunicação Celular , Desenho de Fármacos , Inibidores Enzimáticos/química , Proteínas de Fusão bcr-abl , Humanos , Mesilato de Imatinib , Proteínas de Neoplasias/metabolismo , Neoplasias/enzimologia , Proteínas Oncogênicas/antagonistas & inibidores , Piperazinas/química , Ligação Proteica , Proteínas Proto-Oncogênicas c-kit , Pirimidinas/química , Receptor beta de Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Relação Estrutura-Atividade
16.
J Med Chem ; 35(12): 2327-40, 1992 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-1613756

RESUMO

Potassium channel opening activity for pinacidil-type cyanoguanidines, nitroethenediamines, thioureas, and ureas, has been assessed through simultaneous measurement of spontaneous contractile activity and stimulation of 86Rb+ efflux from rat portal veins loaded with 86Rb+. The good correlation between these two effects suggests that the vasodilator activity of the compounds is directly attributable to an increased opening of potassium channels. The resulting quantitative in vitro data has been used to analyze the structure-activity relationships for potassium channel opening, allowing the biological activity to be rationalized in terms of a pharmacophore involving a hydrogen-bond-acceptor element, a hydrogen-bond-donor element, and a lipophilic binding group. A model for the binding of pinacidil-related compounds to their potassium channel receptor has been developed, and compounds designed to test this model have been synthesized and tested. Prototropic equilibria are implicated as playing a fundamental role in determining the hydrogen-bonding ability of the compounds, and conformational changes in the receptor are invoked to explain disparities in the chiral recognition of lipophilic groups in different compounds.


Assuntos
Diaminas/farmacologia , Guanidinas/farmacologia , Ativação do Canal Iônico/efeitos dos fármacos , Canais de Potássio/fisiologia , Tioureia/farmacologia , Ureia/farmacologia , Vasodilatadores/farmacologia , Animais , Diaminas/química , Guanidinas/síntese química , Guanidinas/química , Masculino , Conformação Molecular , Estrutura Molecular , Contração Muscular/efeitos dos fármacos , Pinacidil , Veia Porta/efeitos dos fármacos , Veia Porta/fisiologia , Canais de Potássio/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Radioisótopos de Rubídio/metabolismo , Relação Estrutura-Atividade , Tioureia/química , Ureia/química , Vasodilatadores/síntese química , Vasodilatadores/química
17.
J Med Chem ; 36(14): 2004-10, 1993 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-8336339

RESUMO

The synthesis of N-cyano-N'-[1,1-dimethyl-[2,2,3,3-3H]propyl]-N"-(3- pyridinyl)guanidine, [3H]-15, is described. The utility of this tritiated radioligand in characterizing the interactions of potassium channel openers and blockers with their receptors is demonstrated. Potassium channel openers of the pinacidil, cromakalim, aprikalim, diazoxide, and minoxidil types, as well as KATP channel blockers of the glibenclamide and eosine types, are all capable of displacing [3H]-15 from its receptor. The results indicate that all of these compounds interact with the same target protein, but that several different allosterically coupled receptor binding sites are probably involved. The highly significant correlation between the ability of the structurally diverse potassium channel openers to inhibit [3H]-15 binding and to relax vascular smooth muscle is consistent with their receptor binding sites being closely associated with the potassium channel protein which is the functional target of this class of drugs.


Assuntos
Guanidinas/síntese química , Guanidinas/metabolismo , Canais de Potássio/efeitos dos fármacos , Piridinas/síntese química , Vasodilatadores/síntese química , Animais , Sítios de Ligação , Interações Medicamentosas , Guanidinas/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Pinacidil , Piridinas/metabolismo , Piridinas/farmacologia , Ratos , Relação Estrutura-Atividade
18.
J Med Chem ; 26(3): 442-5, 1983 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6298430

RESUMO

The preparation, determination of isomeric configuration, and antifungal properties of (E)-1-(5-chlorothien-2-yl)-2-(1H-imidazol-1-yl)ethanone 2,6-dichlorophenylhydrazone hydrochloride (1) are described. In vitro, compound 1 has been shown to have activity against Candida albicans comparable with miconazole. When administered orally to animals with experimentally induced vaginal candidiasis or systemic candidiasis, compound 1 produced results approaching those produced by ketoconazole. In addition, topical administration of compound 1 to rats with vaginal candidiasis produced results comparable with those produced by similar administration of clotrimazole. Unlike ketoconazole, which is active by a mechanism that is essentially fungistatic, compound 1 shares with miconazole a mode of action that is fungicidal. However, unlike miconazole, compound 1 exhibits activity following oral administration. Compound 1 has been found to be negative in the Ames test.


Assuntos
Antifúngicos , Imidazóis/síntese química , Animais , Candida albicans/efeitos dos fármacos , Feminino , Cobaias , Imidazóis/farmacologia , Cetoconazol , Dose Letal Mediana , Masculino , Camundongos , Miconazol/farmacologia , Piperazinas/farmacologia , Ratos , Ratos Endogâmicos
19.
J Med Chem ; 30(10): 1812-8, 1987 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3656356

RESUMO

A series of substituted omega-[2-(1H-imidazol-1-yl)ethoxy]alkanoic acid derivatives were synthesized and evaluated for their ability to inhibit thromboxane synthase both in vitro and in vivo. Compound 13 was identified as a potent and selective competitive inhibitor of human platelet thromboxane synthase having a Ki value of 9.6 X 10(-8) M. In collagen-treated human whole blood, 13 potentiated levels of 6-keto PGF1 alpha. Enantiospecific syntheses afforded the R and S enantiomers of 13, of which the S enantiomer 13b was the more potent. Compounds 13 and 13b were potent in vivo inhibitors of thromboxane synthase with good oral activity and duration of action.


Assuntos
Caproatos/síntese química , Inibidores Enzimáticos/síntese química , Imidazóis/síntese química , Tromboxano-A Sintase/antagonistas & inibidores , 6-Cetoprostaglandina F1 alfa/sangue , Administração Oral , Animais , Caproatos/farmacologia , Colágeno/farmacologia , Inibidores Enzimáticos/farmacologia , Cobaias , Humanos , Imidazóis/farmacologia , Cinética , Endoperóxidos Sintéticos de Prostaglandinas/metabolismo , Prostaglandina H2 , Prostaglandinas H/metabolismo , Estereoisomerismo , Tromboxano B2/sangue
20.
J Med Chem ; 30(9): 1588-95, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3305945

RESUMO

Analogues of 4-[[2-(1H-imidazol-1-yl)-1-[[(4-methoxyphenyl)methoxy]methyl] ethoxy]methyl]benzoic acid (5m) were prepared and evaluated as thromboxane synthase inhibitors. A series of esters of 5m showed a parabolic relationship between lipophilicity and inhibition of TxB2 generation in intact platelets, with activities up to 50 times greater than that of dazoxiben. However, on administration to rabbits the ethyl ester 5d had a short duration of action, due to rapid metabolism and excretion via deesterification and beta-glucuronidation. Attempts at replacing the carboxylate group with other potential pharmacophores were unsuccessful.


Assuntos
Imidazóis/farmacologia , Tromboxano-A Sintase/antagonistas & inibidores , Animais , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Cromatografia Líquida de Alta Pressão , Colágeno/farmacologia , Epoprostenol/biossíntese , Humanos , Coelhos , Relação Estrutura-Atividade , Tromboxano A2/biossíntese , Tromboxano B2/sangue
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