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1.
Surg Endosc ; 37(4): 2659-2672, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36401105

RESUMO

BACKGROUND: Many centers worldwide are shifting from laparoscopic to robotic minimally invasive hepato-pancreato-biliary resections (MIS-HPB) but large single center series assessing this process are lacking. We hypothesized that the introduction of robot-assisted surgery was safe and feasible in a high-volume center. METHODS: Single center, post-hoc assessment of prospectively collected data including all consecutive MIS-HPB resections (January 2010-February 2022). As of December 2018, all MIS pancreatoduodenectomy and liver resections were robot-assisted. All surgeons had participated in dedicated training programs for laparoscopic and robotic MIS-HPB. Primary outcomes were in-hospital/30-day mortality and Clavien-Dindo ≥ 3 complications. RESULTS: Among 1875 pancreatic and liver resections, 600 (32%) were MIS-HPB resections. The overall rate of conversion was 4.3%, Clavien-Dindo ≥ 3 complications 25.7%, and in-hospital/30-day mortality 1.8% (n = 11). When comparing the period before and after the introduction of robotic MIS-HPB (Dec 2018), the overall use of MIS-HPB increased from 25.3 to 43.8% (P < 0.001) and blood loss decreased from 250 ml [IQR 100-500] to 150 ml [IQR 50-300] (P < 0.001). The 291 MIS pancreatic resections included 163 MIS pancreatoduodenectomies (52 laparoscopic, 111 robotic) with 4.3% conversion rate. The implementation of robotic pancreatoduodenectomy was associated with reduced operation time (450 vs 361 min; P < 0.001), reduced blood loss (350 vs 200 ml; P < 0.001), and a decreased rate of delayed gastric emptying (28.8% vs 9.9%; P = 0.009). The 309 MIS liver resections included 198 laparoscopic and 111 robotic procedures with a 3.6% conversion rate. The implementation of robotic liver resection was associated with less overall complications (24.7% vs 10.8%; P = 0.003) and shorter hospital stay (4 vs 3 days; P < 0.001). CONCLUSION: The introduction of robotic surgery was associated with greater implementation of MIS-HPB in up to nearly half of all pancreatic and liver resections. Although mortality and major morbidity were not affected, robotic surgery was associated with improvements in some selected outcomes. Ultimately, randomized studies and high-quality registries should determine its added value.


Assuntos
Laparoscopia , Procedimentos Cirúrgicos Robóticos , Humanos , Hepatectomia/métodos , Fígado/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos , Pâncreas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Estudos Prospectivos
3.
Scand J Surg ; 109(1): 29-33, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32192422

RESUMO

INTRODUCTION: There has been a rapid development in minimally invasive pancreas surgery in recent years. The most recent innovation is robotic pancreatoduodenectomy. Several studies have suggested benefits as compared to the open or laparoscopic approach. This review provides an overview of studies concerning patient selection, volume criteria, and training programs for robotic pancreatoduodenectomy and identified knowledge gaps regarding barriers for safe implementation of robotic pancreatoduodenectomy. MATERIALS AND METHODS: A Pubmed search was conducted concerning patient selection, volume criteria, and training programs in robotic pancreatoduodenectomy. RESULTS: A total of 20 studies were included. No contraindications were found in patient selection for robotic pancreatoduodenectomy. The consensus and the Miami guidelines advice is a minimum annual volume of 20 robotic pancreatoduodenectomy procedures per center, per year. One training program was identified which describes superior outcomes after the training program and shortening of the learning curve in robotic pancreatoduodenectomy. CONCLUSION: Robotic pancreatoduodenectomy is safe and feasable for all indications when performed by specifically trained surgeons working in centers who can maintain a minimum volume of 20 robotic pancreatoduodenectomy procedures per year. Large proficiency-based training program for robotic pancreatoduodenectomy seem essential to facilitate a safe implementation and future research on robotic pancreatoduodenectomy.


Assuntos
Pancreatopatias/cirurgia , Pancreaticoduodenectomia , Seleção de Pacientes , Procedimentos Cirúrgicos Robóticos , Competência Clínica/normas , Competência Clínica/estatística & dados numéricos , Educação/normas , Educação/estatística & dados numéricos , Educação de Pós-Graduação em Medicina/normas , Educação de Pós-Graduação em Medicina/estatística & dados numéricos , Hospitais com Alto Volume de Atendimentos/normas , Hospitais com Alto Volume de Atendimentos/estatística & dados numéricos , Humanos , Laparoscopia , Curva de Aprendizado , Procedimentos Cirúrgicos Minimamente Invasivos , Pancreaticoduodenectomia/educação , Pancreaticoduodenectomia/métodos , Pancreaticoduodenectomia/normas , Pancreaticoduodenectomia/estatística & dados numéricos , Procedimentos Cirúrgicos Robóticos/educação , Procedimentos Cirúrgicos Robóticos/métodos , Procedimentos Cirúrgicos Robóticos/normas , Procedimentos Cirúrgicos Robóticos/estatística & dados numéricos , Cirurgiões/normas , Cirurgiões/estatística & dados numéricos , Resultado do Tratamento
4.
J Vis Exp ; (155)2020 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-31957744

RESUMO

Pancreatic parenchyma sparing surgery for insulinomas avoids the risk of endocrine and exocrine insufficiency, and potential high-risk anastomoses associated with pancreatic resection. Robotic surgery may be used as an alternative for open pancreatic enucleation without compromising dexterity and 3D-vision. We present the case of a 42-year old woman who presented with sweating, tremor and episodes of hypoglycemia. A fasting test confirmed endogenic insulin overproduction. After inconclusive CT- and MRI imaging, endoscopic ultrasonography showed a hypoechoic lesion, which was fully within the pancreatic head. Although consent was obtained for pancreatoduodenectomy, robotic enucleation seemed feasible. After mobilization, intraoperative ultrasonography was used to identify the lesion and its relation with the pancreatic duct. Dissection was performed using a traction suture, hot shears and bipolar diathermia. A sealant patch was applied for hemostasis and a drain placed. The patient developed a grade B pancreatic fistula for which endoscopic sphincterotomy was performed; the surgical drain could be removed in the outpatient clinic after 20 days. Prospective studies should confirm the short- and long-term benefits of robotic enucleation of insulinomas.


Assuntos
Insulinoma/cirurgia , Pâncreas/cirurgia , Neoplasias Pancreáticas/cirurgia , Procedimentos Cirúrgicos Robóticos , Adulto , Dissecação , Feminino , Humanos , Insulinoma/diagnóstico por imagem , Insulinoma/patologia , Pancreatectomia , Ductos Pancreáticos/cirurgia , Neoplasias Pancreáticas/patologia , Estudos Prospectivos , Resultado do Tratamento
5.
Nat Commun ; 10(1): 4796, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641138

RESUMO

Interneurons (INs) coordinate motoneuron activity to generate appropriate patterns of muscle contractions, providing animals with the ability to adjust their body posture and to move over a range of speeds. In Drosophila larvae several IN subtypes have been morphologically described and their function well documented. However, the general lack of molecular characterization of those INs prevents the identification of evolutionary counterparts in other animals, limiting our understanding of the principles underlying neuronal circuit organization and function. Here we characterize a restricted subset of neurons in the nerve cord expressing the Maf transcription factor Traffic Jam (TJ). We found that TJ+ neurons are highly diverse and selective activation of these different subtypes disrupts larval body posture and induces specific locomotor behaviors. Finally, we show that a small subset of TJ+ GABAergic INs, singled out by the expression of a unique transcription factors code, controls larval crawling speed.


Assuntos
Proteínas de Drosophila/metabolismo , Drosophila/fisiologia , Interneurônios/fisiologia , Fatores de Transcrição Maf Maior/metabolismo , Atividade Motora/fisiologia , Proteínas Proto-Oncogênicas/metabolismo , Animais , Animais Geneticamente Modificados , Drosophila/embriologia , Proteínas de Drosophila/genética , Embrião não Mamífero/fisiologia , Regulação da Expressão Gênica , Inativação Gênica , Larva/fisiologia , Locomoção/fisiologia , Fatores de Transcrição Maf Maior/genética , Proteínas Proto-Oncogênicas/genética , Raízes Nervosas Espinhais/fisiologia , Ácido gama-Aminobutírico/metabolismo
6.
J Robot Surg ; 13(6): 717-727, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31049774

RESUMO

Minimally invasive surgery (MIS) is quickly becoming mainstream in hepato-pancreato-biliary surgery because of presumed advantages. Surgery for perihilar cholangiocarcinoma (PHC) is highly demanding which may hamper the feasibility and safety of MIS in this setting. This study aimed to systematically review the existing literature on MIS for PHC. A systematic literature review was performed according to the PRISMA statement. The PubMed and EMBASE databases were searched and all studies describing MIS in patients with PHC were included. Data extraction and risk of bias were assessed by two independent researchers. Overall, 21 studies reporting on a total of 142 MIS procedures for PHC were included. These included 82 laparoscopic, 59 robot-assisted and 1 hybrid procedure(s). Risk of bias was deemed substantial. Pooled conversion rate was 7/142 (4.9%), pooled morbidity 30/126 (23.8%), and pooled mortality rate 4/126 (3.2%). The only comparative study, comparing 10 robot-assisted procedures to 32 open procedures, reported a significant increased operative time and higher morbidity rate with MIS. The available evidence on MIS for PHC is limited and generally of poor quality. This systematic review shows that the implementation of MIS for patients with PHC is still in its infancy.


Assuntos
Tumor de Klatskin/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos , Humanos
7.
Maturitas ; 83: 65-71, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26546077

RESUMO

OBJECTIVE: To perform an external validation of FRAX algorithm thresholds for reporting level of risk of fracture in Spanish women (low < 5%; intermediate ≥ 5% and < 7.5%; high ≥ 7.5%) taken from a prospective cohort "FRIDEX". METHODS: A retrospective study of 1090 women aged ≥ 40 and ≤ 90 years old obtained from the general population (FROCAT cohort). FRAX was calculated with data registered in 2002. All fractures were validated in 2012. Sensitivity analysis was performed. RESULTS: When analyzing the cohort (884) excluding current or past anti osteoporotic medication (AOM), using our nominated thresholds, among the 621 (70.2%) women at low risk of fracture, 5.2% [CI95%: 3.4-7.6] sustained a fragility fracture; among the 99 at intermediate risk, 12.1% [6.4-20.2]; and among the 164 defined as high risk, 15.9% [10.6-24.2]. Sensitivity analysis against model risk stratification FRIDEX of FRAX Spain shows no significant difference. By including 206 women with AOM, the sensitivity analysis shows no difference in the group of intermediate and high risk and minimal differences in the low risk group. CONCLUSIONS: Our findings support and validate the use of FRIDEX thresholds of FRAX when discussing the risk of fracture and the initiation of therapy with patients.


Assuntos
Algoritmos , Fraturas por Osteoporose/epidemiologia , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Espanha/epidemiologia
8.
J Fish Dis ; 35(11): 817-26, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22913744

RESUMO

White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable number tandem repeats (VNTR) located in ORF75, ORF94 and ORF125. In the current study, we investigated whether or not the number of repeat units in the VNTRs correlates with virus outbreak status and/or shrimp farming practice. We analysed 662 WSSV samples from individual WSSV-infected Penaeus monodon shrimp from 104 ponds collected from two important shrimp farming regions of the Mekong Delta: Ca Mau and Bac Lieu. Using this large data set and statistical analysis, we found that for ORF94 and ORF125, the mean number of repeat units (RUs) in VNTRs was significantly lower in disease outbreak ponds than in non-outbreak ponds. Although a higher mean RU number was observed in the improved-extensive system than in the rice-shrimp or semi-intensive systems, these differences were not significant. VNTR sequences are thus not only useful markers for studying WSSV genotypes and populations, but specific VNTR variants also correlate with disease outbreaks in shrimp farming systems.


Assuntos
Repetições Minissatélites/genética , Penaeidae/virologia , Vírus da Síndrome da Mancha Branca 1/fisiologia , Animais , Aquicultura , Genótipo , Vietnã , Vírus da Síndrome da Mancha Branca 1/genética
10.
Exp Neurol ; 201(1): 154-64, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16762344

RESUMO

Environmental enrichment and exercise may be neuroprotective or promote recovery after different forms of CNS injury. Here, we tested the possible effects of moderate environmental enrichment and voluntary exercise on the outcome of incomplete spinal cord injury in rats. We provided rats in standard cages with basic environmental enrichment (carton house, nesting material, tube, gnawing sticks). We also analyzed the effect of increased activity by housing spinal-cord-injured rats in cages with or without access to running wheels. In a third experiment, we looked at the possible effect of pre-injury training. In all experiments, a battery of behavior tests were used. Enriched environment provided before, after or both before and after injury did not alter the outcome on any of these tests. Similarly, despite excessive running after injury, no differences in terms of recovery and behavior were found in the running experiment. Similarly, running prior to injury did not significantly decrease the degree of functional deficit caused by the injury. Since there were no effects of further enrichment, above the possible effects of being socially housed, and since exercise did not improve the outcome, we conclude that these forms of increased activity do not render the animals significantly less sensitive to spinal cord injury and do not cause robust improvement when initiated after injury. While these results pose a limit to how helpful environmental and physical training programs may be in rodent impact injury models, they do not contradict the fact that voluntary and guided training can be effective tools in human spinal cord rehabilitation.


Assuntos
Abrigo para Animais/normas , Condicionamento Físico Animal/fisiologia , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Animais , Comportamento Animal/fisiologia , Corticosterona/urina , Feminino , Atividade Motora/fisiologia , Gravidez , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
11.
Heart ; 88(3): 234-8, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12181212

RESUMO

BACKGROUND: Fibric acid derivatives and HMG-CoA reductase inhibitors are effective in combination for treating patients with familial dysbetalipoproteinaemia and severe combined dyslipidaemia, but combination therapy affects compliance and increases the risk of side effects. AIM: To evaluate the efficacy and safety of monotherapy with atorvastatin, an HMG-CoA reductase inhibitor with superior efficacy in lowering low density lipoprotein cholesterol and triglyceride concentrations, in patients with dysbetalipoproteinaemia and severe combined dyslipidaemia. METHODS: Atorvastatin was tested as single drug treatment in 36 patients with familial dysbetalipoproteinaemia and 23 patients with severe combined dyslipidaemia. RESULTS: After 40 weeks of 40 mg atorvastatin treatment decreases in total cholesterol, triglycerides, and apolipoprotein B of 40%, 43%, and 41%, respectively, were observed in the combined dyslipidaemia group, and of 46%, 40%, and 43% in the dysbetalipoproteinaemic patients. Target concentrations of total cholesterol (< 5 mmol/l) were reached by 63% of the patients, and target concentrations of triglycerides (< 3.0 mmol/l) by 66%. Treatment with atorvastatin was well tolerated and no serious side effects were reported. CONCLUSIONS: Atorvastatin is very effective as monotherapy in the treatment of familial dysbetalipoproteinaemia and severe combined dyslipidaemia.


Assuntos
Ácidos Heptanoicos/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipidemias/tratamento farmacológico , Hiperlipoproteinemia Tipo III/tratamento farmacológico , Pirróis/uso terapêutico , Adulto , Idoso , Apolipoproteínas B/sangue , Apolipoproteínas B/genética , Atorvastatina , Colesterol/sangue , Feminino , Ácidos Heptanoicos/efeitos adversos , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/efeitos adversos , Hiperlipidemias/sangue , Hiperlipoproteinemia Tipo III/sangue , Masculino , Pessoa de Meia-Idade , Pirróis/efeitos adversos , Resultado do Tratamento , Triglicerídeos/sangue
12.
Atherosclerosis ; 154(3): 641-9, 2001 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-11257265

RESUMO

Paraoxonase is an enzyme associated with the high-density lipoprotein (HDL) particle. It catalyses the hydrolysis of organophosphates and protects LDL from oxidative modification in vitro by hydrolyzing lipid peroxides, suggestive of a role for paraoxonase in the development of atherosclerosis. Two frequent mutations at the paraoxonase gene locus (PON1) underlie the leucine (Leu allele) --> methionine (Met allele) and the glutamine(Gln allele) --> arginine(Arg allele) aminoacid substitutions at residues 55 and 192, respectively. These polymorphisms have been associated with increased risk for cardiovascular disease (CVD) in several studies, while others have not found this association. Recently, another member of the PON gene family designated PON2 has been identified. While the PON2 gene product is expressed ubiquitously, its physiological role is unknown. A common polymorphism at codon 311 (Cys-->Ser) in the PON2 gene has been described. In our study we assessed the frequency and genotype distribution of the PON1 and PON2 polymorphisms in 197 patients with familial hypercholesterolemia (FH), to determine the possible association between these mutations and susceptibility for CVD. The FH cohort group was divided into subjects with (n=83) and without (n=114) definite clinical manifestations of CVD (FH-Symptomatic and FH-Asymptomatic respectively). The control population consisted of 201 healthy normolipidemic blood donors. All subjects in this study were of Caucasian background. Genotypes were identified by PCR based analysis. With regard to the PON1 polymorphisms 55 and 192, no different distributions of allele frequencies were found between the groups studied. However, we did show an association between the PON2 311 polymorphism and CVD. The frequencies of PON2 Ser311 carriers (Ser/Ser and Cys/Ser) between FH-Symptomatic and both FH-Asymptomatic and controls did show a significant difference (P=0.01 and P=0.02 respectively). In the FH-Symptomatic population, surprisingly, no subjects were homozygous for PON2 Cys311, whereas in the FH-Asymptomatic population nine persons (7.9%) and in the control group 12 persons (6.0%) were homozygous. Our data indicate that the common PON2 polymorphism is associated with clinical manifestations of CVD in FH patients. While PON2 Ser311 carriers seem to be at risk, subjects with the Cys/Cys311 genotype are likely to be protected against the development of premature CVD.


Assuntos
Doenças Cardiovasculares/etiologia , Esterases/genética , Variação Genética , Hiperlipoproteinemia Tipo II/complicações , Hiperlipoproteinemia Tipo II/genética , Adulto , Alelos , Arildialquilfosfatase , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/fisiopatologia , Feminino , Frequência do Gene , Ligação Genética , Genótipo , Haplótipos , Humanos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade
13.
Cardiovasc Res ; 42(3): 752-60, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10533616

RESUMO

OBJECTIVE: Dihydropyridine calcium antagonists have been shown to retard atherogenesis in animal models and to prevent the development of early angiographic lesions in human coronary arteries. Endothelial dysfunction is an early event in the pathogenesis of cardiovascular disease. We investigated whether nifedipine could improve endothelial function in hypercholesterolemia, independently of changes in blood pressure or plasma lipids. METHODS: First, we compared in vivo forearm vascular responses to the endothelium-dependent and independent vasodilators serotonin (5-HT) and sodium nitroprusside (SNP) in 11 patients with familial hypercholesterolemia before and after 6-weeks treatment with nifedipine GITS (60 mg, OD) and in 12 matched controls. In a subgroup of six control subjects forearm vascular function was also assessed before and after 6-weeks nifedipine GITS treatment. In vitro, we subsequently explored possible mechanisms underlying the effect of nifedipine on endothelial function. We investigated the effects of nifedipine on both NO production by recombinant endothelial NO synthase (eNOS) and endothelial cells, using 3H-arginine conversion, as well as on superoxide generation by endothelial cell lysates, using lucigenin enhanced chemiluminescence. RESULTS: In hypercholesterolemia 5-HT-induced vasodilation was impaired (47 +/- 9% increase in forearm bloodflow vs. 99 +/- 8% in controls). Treatment with nifedipine completely restored 5-HT-induced vasodilation (113 +/- 13%), whereas it did not influence basal forearm vasomotion or SNP-induced vasodilation. Nifedipine did not alter forearm vascular responses in control subjects and did not alter blood pressure or plasma lipids. In vitro, we found no direct effect of nifedipine on NO production by recombinant eNOS or endothelial cells. However, we did observe a reduction in endothelial superoxide generation. CONCLUSIONS: Our data show that nifedipine improves endothelial function in hypercholesterolemia. It is suggested from our in vitro experiments that this effect is due to reduced NO degradation.


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Endotélio Vascular/efeitos dos fármacos , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Nifedipino/uso terapêutico , Adulto , Estudos de Casos e Controles , Células Cultivadas , Endotélio Vascular/metabolismo , Feminino , Humanos , Hiperlipoproteinemia Tipo II/metabolismo , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo III , Nitroprussiato/farmacologia , Proteínas Recombinantes/metabolismo , Fluxo Sanguíneo Regional/efeitos dos fármacos , Serotonina/farmacologia , Fatores de Tempo , Vasodilatadores/farmacologia
14.
J Med Chem ; 42(8): 1384-92, 1999 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-10212124

RESUMO

Novel as well as known 5'-N-substituted carboxamidoadenosines were prepared via new routes that provided shorter reaction times and good yields. Binding affinities were determined for rat A1 and A2A receptors and human A3 receptors. EC50 values were determined for cyclic AMP production in CHO cells expressing human A2B receptors. On all receptor subtypes relatively small substituents on the carboxamido moiety were optimal. Selectivity for the A3 receptor was found for several analogues (1a, 1d, 1h, and 1k). On A1 receptors a number of compounds, but not 5'-N-ethylcarboxamidoadenosine (NECA, 1b), showed small GTP shifts, which could be indicative of lower intrinsic activities at the A1 receptor. At the A2B receptor, derivatives 1i-k with modified ethyl substituents had reduced activities compared to the A2B reference agonist NECA (1b). Thiocarboxamido derivatives (8b and 8c) displayed considerable although decreased A2B receptor activity. The X-ray structure determination of compound 8b was carried out. Due to intramolecular hydrogen bonding between the carboxamido NH and the purine N3 in the crystal structure, the ribose moiety of this compound is in a syn conformation. However, theoretical calculations support that NECA (1b), and less so 8b, can readily adopt both the syn and the anti conformation, therefore not excluding the proposed anti mode of binding to the receptor.


Assuntos
Adenosina/análogos & derivados , Adenosina/síntese química , Agonistas do Receptor Purinérgico P1 , Adenosina/química , Adenosina/farmacologia , Animais , Células CHO , Linhagem Celular , Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Cricetinae , Cristalografia por Raios X , AMP Cíclico/biossíntese , Humanos , Técnicas In Vitro , Conformação Molecular , Ensaio Radioligante , Ratos , Receptores Purinérgicos P1/metabolismo , Relação Estrutura-Atividade
15.
Nucleosides Nucleotides ; 17(6): 969-85, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9708319

RESUMO

Various adenosine analogues were tested at the adenosine A2B receptor. Agonist potencies were determined by measuring the cyclic AMP production in Chinese Hamster Ovary cells expressing human A2B receptors. 5'-N-Substituted carboxamidoadenosines were most potent. 5'-N-Ethylcarboxamidoadenosine (NECA) was most active with an EC50 value of 3.1 microM. Other ribose modified derivatives displayed low to negligible activity. Potency was reduced by substitution on the exocyclic amino function (N6) of the purine ring system. The most active N6-substituted derivative N6-methyl-NECA was 5 fold less potent than NECA. C8- and most C2-substituted analogues were virtually inactive. 1-Deaza-analogues had a reduced potency, 3- and 7-deazaanalogues were not active.


Assuntos
Adenosina-5'-(N-etilcarboxamida)/análogos & derivados , Adenosina/análogos & derivados , Agonistas do Receptor Purinérgico P1 , Adenosina/farmacologia , Adenosina-5'-(N-etilcarboxamida)/farmacologia , Animais , Células CHO , Cricetinae , AMP Cíclico/biossíntese , Humanos , Receptor A2B de Adenosina , Proteínas Recombinantes/agonistas
16.
J Med Chem ; 41(15): 2835-45, 1998 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-9667972

RESUMO

The adenosine antagonist 9-chloro-2-(2-furanyl)[1,2,4]triazolo[1, 5-c]quinazolin-5-amine (CGS 15943) binds nonselectively to human A1, A2A, and A3 receptors with high affinity. Acylated derivatives and one alkyl derivative of the 5-amino group and other modifications were prepared in an effort to enhance A2B or A3 subtype potency. In general, distal modifications of the N5-substituent were highly modulatory to potency and selectivity at adenosine receptors, as determined in radioligand binding assays at rat brain A1 and A2A receptors and at recombinant human A3 receptors. In Chinese hamster ovary cells stably transfected with human A2B receptor cDNA, inhibition of agonist-induced cyclic AMP production was measured. An N5-(2-iodophenyl)acetyl derivative was highly selective for A2A receptors. An (R)-N5-alpha-methyl(phenylacetyl) derivative was the most potent derivative at A3 receptors, with a Ki value of 0.36 nM. A bulky N5-diphenylacetyl derivative, 13, displayed a Ki value of 0. 59 nM at human A3 receptors and was moderately selective for that subtype. Thus, a large, nondiscriminating hydrophobic region occurs in the A3 receptor in proximity to the N5-substituent. A series of straight-chain N5-aminoalkylacyl derivatives demonstrated that for A2B receptors the optimal chain length occurs with three methylene groups, i.e., the N5-gamma-aminobutyryl derivative 27 which had a pA2 value of 8.0 but was not selective for A2B receptors. At A1, A2A, and A3 receptors however the optimum occurs with four methylene groups. An N5-pivaloyl derivative, which was less potent than 27 at A1, A2A, and A3 receptors, retained moderate potency at A2B receptors. A molecular model of the 27-A2B receptor complex based on the structure of rhodopsin utilizing a "cross-docking" procedure was developed in order to visualize the environment of the ligand binding site.


Assuntos
Antagonistas de Receptores Purinérgicos P1 , Quinazolinas , Quinazolinas/farmacologia , Triazóis , Triazóis/farmacologia , Animais , Células CHO , Córtex Cerebral/metabolismo , Cricetinae , AMP Cíclico/antagonistas & inibidores , Humanos , Modelos Moleculares , Conformação Molecular , Conformação Proteica , Quinazolinas/síntese química , Quinazolinas/química , Quinazolinas/metabolismo , Ratos , Receptor A2A de Adenosina , Receptor A2B de Adenosina , Receptor A3 de Adenosina , Receptores Purinérgicos P1/biossíntese , Receptores Purinérgicos P1/química , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/biossíntese , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química , Triazóis/metabolismo
17.
J Med Chem ; 34(3): 1193-201, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2002460

RESUMO

A series of both aliphatic and aromatic amides and aromatic amidines derived from 2-amino-1,10-phenanthroline (3) according to the Topliss scheme were synthesized and subsequently tested for antimycoplasmal potency. Although the compounds themselves showed no activity, in the presence of a nontoxic copper concentration of 40 microM all compounds appeared to be very active against Mycoplasma gallisepticum K154. The most active compounds were found in the amide series and show growth inhibition in the nanomolar range. These compounds are 4 times more active than tylosin, a macrolide antibiotic, which is used therapeutically in veterinary practice. In the presence of copper, amides derived from 3 are more active than corresponding amidines. Increased activity following derivatization of 3 may be due to the presence of a third coordination site for copper in the title compounds. Evaluation of biological data revealed that antimycoplasmal activity of amides derived from 3 is dependent on lipophilicity. For these amides a good linear correlation was found between antimycoplasmal activity and hydrophobic fragmental values for substituents considered. This quantitative structure-activity relationship study indicated that antimycoplasmal activity was increased upon a decrease of these hydrophobic fragmental values.


Assuntos
Amidas/química , Amidas/síntese química , Amidinas/química , Amidinas/síntese química , Cobre/farmacologia , Mycoplasma/efeitos dos fármacos , Fenantrolinas/química , Amidas/farmacologia , Amidinas/farmacologia , Fenômenos Químicos , Química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Fenantrolinas/farmacologia , Relação Estrutura-Atividade , Tilosina/farmacologia
18.
J Med Chem ; 32(2): 487-93, 1989 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2913309

RESUMO

In our search for new compounds with antimycoplasmal activity, a series of aromatic amidines derived from 1-amino-3-(2-pyridyl)isoquinoline (1) was synthesized. In the presence of 40 microM copper the most active compounds show growth inhibition of Mycoplasma gallisepticum in the nanomolar range. These compounds are 3 times as active as tylosin, an antimycoplasmal therapeutic agent that is used in veterinary practice. In the presence of copper, amidines derived from 1 are 2-3 times more active than the corresponding amides. Furthermore it was established that for these compounds too, the presence of a 2,2'-bipyridyl moiety is a necessary prerequisite for antimycoplasmal activity. As for the amides, antimycoplasmal activity of amidines derived from 1 is dependent on the hydrophobic fragmental value of the aromatic nucleus of the amidine moiety. A quantitative structure-activity relationship established the optimal hydrophobic fragmental value of this part of the molecule to be zero.


Assuntos
Amidinas/síntese química , Antibacterianos/síntese química , Cobre/farmacologia , Mycoplasma/efeitos dos fármacos , Amidinas/farmacologia , Antibacterianos/farmacologia , Relação Estrutura-Atividade
19.
J Med Chem ; 31(4): 716-22, 1988 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3351847

RESUMO

In order to investigate the antimycoplasmal activity of compounds structurally related to 2,2'-bipyridyl, a series of both aliphatic and aromatic amides derived from 1-amino-3-(2-pyridyl)isoquinoline were synthesized. The most active compounds appeared to be as active as Tylosin, an antimycoplasmal therapeutic that is used in veterinary practice, in the presence of a small nontoxic amount of copper. Furthermore, it was found that antimycoplasmal activity depends on the hydrophobic fragmental value of amide residue. A quantitative structure-activity relationship established the optimal hydrophobic fragmental value of the amide residue to be 0.30.


Assuntos
Antibacterianos/síntese química , Cobre/metabolismo , Isoquinolinas/síntese química , Mycoplasma/efeitos dos fármacos , Piridinas/síntese química , 2,2'-Dipiridil , Amidas/síntese química , Amidas/farmacologia , Amidinas/síntese química , Amidinas/farmacologia , Antibacterianos/farmacologia , Isoquinolinas/farmacologia , Leucomicinas/uso terapêutico , Testes de Sensibilidade Microbiana , Piridinas/farmacologia , Relação Estrutura-Atividade , Tilosina
20.
Biochim Biophys Acta ; 914(2): 162-9, 1987 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-3300781

RESUMO

The influence of the steric hindrance of halogen substituents was investigated in vitro by measuring the activity of yeast aldehyde dehydrogenase (aldehyde: NAD(P)+ oxidoreductase, EC 1.2.1.5) and of aldehyde dehydrogenases in subcellular rat liver fractions with a series of ortho- and para-halo-substituted benzaldehydes as substrates. Upon an increase in the size of the halogen substituent (F, Cl, Br), the reactivity of yeast aldehyde dehydrogenase to ortho-substituted benzaldehydes decreased drastically. The same phenomenon was observed with the unspecific aldehyde dehydrogenases in three rat liver fractions; cytoplasm, mitochondria and microsomes. The corresponding para-halobenzaldehydes (F, Cl, Br, I) did not reveal large differences in reactivity to the various rat liver aldehyde dehydrogenases. The aldehyde dehydrogenases in the rat liver microsomal fraction exhibited most clearly the regiospecificity. Enzymatic oxidation of 4-bromobenzaldehyde was more than 30-times faster then the ortho-isomer. The findings in this investigation confirm the suggestion that the steric hindrance of bulky ortho-substituents of benzaldehydes account for the slowing down of the aldehyde dehydrogenase-catalyzed oxidation of benzaldehydes to corresponding benzoic acids. The enzymatic oxidation of microsomal aldehyde dehydrogenase is strongly influenced by steric effects of benzaldehydes, bearing a halogen in ortho-position. We think that the microsomal aldehyde dehydrogenase might be the principal enzyme responsible for oxidation of halobenzaldehydes in rat liver.


Assuntos
Aldeído Desidrogenase/metabolismo , Microssomos Hepáticos/enzimologia , Mitocôndrias Hepáticas/enzimologia , Animais , Benzaldeídos , Masculino , Ratos , Ratos Endogâmicos , Saccharomyces cerevisiae/enzimologia , Especificidade por Substrato
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