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1.
ESMO Open ; 7(1): 100354, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34953402

RESUMO

BACKGROUND: Lung cancer with related pericardial effusion is not rare. Intervention is a crucial step for symptomatic effusion. It is unknown, however, whether the different invasive interventions for pericardial effusion result in different survival outcomes. This study analyzed the clinical characteristics and prognostic factors for patients with non-small-cell lung cancer (NSCLC) who have undergone different procedures. METHODS: From January 2006 to June 2018, we collected data from patients with NSCLC who have received invasive intervention for pericardial effusions. The patients were divided into three categories: simple pericardiocentesis, balloon pericardiotomy, and surgical pericardiectomy. Kaplan-Meier curve and log-rank test were used to analyze the pericardial effusion recurrence-free survival (RFS) and overall survival (OS). RESULTS: A total of 244 patients were enrolled. Adenocarcinoma (83.6%) was the major NSCLC subtype. Invasive intervention, including simple pericardiocentesis, balloon pericardiotomy, and surgical pericardiectomy, had been carried out on 52, 170, and 22 patients, respectively. The 1-year RFS rates in simple pericardiocentesis, balloon pericardiotomy, and surgical pericardiectomy were 19.2%, 31.2%, and 31.8%, respectively (P = 0.128), and the median RFS was 1.67, 5.03, and 8.32 months, respectively (P = 0.008). There was no significant difference in OS, however, with the median OS at 1.67, 6.43, and 8.32 months, respectively (P = 0.064). According to the multivariable analysis, the gravity in pericardial fluid analysis, receiving systemic therapy after pericardial effusion, and the time period from stage IV lung cancer to the presence of pericardial effusion were independent prognostic factors for pericardial effusion RFS and OS. CONCLUSIONS: Patients who have undergone simple pericardiocentesis alone for the management of NSCLC-related pericardial effusion have lower 1-year RFS rates than those who have undergone balloon pericardiotomy and surgical pericardiectomy. Therefore, balloon pericardiotomy and surgical pericardiectomy should be carried out for patients with NSCLC-related pericardial effusion if tolerable.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Derrame Pericárdico , Carcinoma Pulmonar de Células não Pequenas/complicações , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Humanos , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/cirurgia , Derrame Pericárdico/etiologia , Derrame Pericárdico/cirurgia , Pericardiectomia/métodos , Pericardiocentese/métodos
5.
Med J Malaysia ; 63(2): 131-6, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18942299

RESUMO

CT angiography (CTA) is a fast examination performed with a time-optimised contrast injection to enhance the cerebral arteries. Being a new imaging modality in our hospital, evaluation of the effectiveness of 64-row multislice CTA in detecting intracranial aneurysms in ruptured subarachnoid haemorrhage (SAH) cases is necessary. We conducted a descriptive prospective study by recruiting 30 consecutively operated SAH cases from May 2005 until November 2006. CTA findings were studied by radiologist and neurosurgeon and these were compared with operative findings. The sensitivity and specificity of CTA were 94.4% and 97.2% respectively. Approximately half of the patients were scanned within four hours and operated within 24 hours. In conclusion, CTA proves to be highly sensitive and specific in the diagnosis of intracranial aneurysms in our study.


Assuntos
Angiografia/métodos , Aneurisma Intracraniano/diagnóstico por imagem , Hemorragia Subaracnóidea/complicações , Tomografia Computadorizada por Raios X/métodos , Doença Aguda , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
6.
Biochimie ; 84(2-3): 223-31, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12022953

RESUMO

Programmed cell death (PCD) contributes to development, maintenance, and pathology in various tissues, including the nervous system. Many molecular, biochemical, and genetic events occur within cells undergoing PCD. Some of these events are incompatible with long-term cell survival because they have irreversible, catastrophic consequences. The onset of such changes marks the point of no return, a decisive regulatory event termed 'the commitment-to-die.' In this review, we discuss events that underlie the commitment-to-die in nerve growth factor-deprivation-induced death of sympathetic neurons. Findings in this model system implicate the mitochondrion as an important site of regulation for the commitment-to-die in the presence or absence of caspase inhibition.


Assuntos
Apoptose/fisiologia , Inibidores de Caspase , Mitocôndrias/fisiologia , Fatores de Crescimento Neural/deficiência , Fatores de Crescimento Neural/fisiologia , Neurônios/citologia , Sistema Nervoso Simpático/citologia , Animais , Caspases/deficiência , Caspases/genética , Peptidil-Prolil Isomerase F , Ciclofilinas/metabolismo , Ciclosporina/farmacologia , Inibidores Enzimáticos/farmacologia , Humanos
7.
Dermatol Surg ; 27(8): 759-63, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11493302

RESUMO

BACKGROUND: In recent years herbal medicines and supplements have become increasingly popular. With their increased popularity, more publications are warning about the potential harmful effects of some of these products. OBJECTIVE: To present scientific evidence of the benefits and surgical risks of herbal products. METHODS: A Medline search and review of the literature was performed. RESULTS: Many herbal medicines are relevant in dermatologic surgery since Ginkgo biloba, garlic, ginger, ginseng, feverfew, and vitamin E may increase the risk of bleeding, and ephedra may potentiate the side effects of epinephrine. CONCLUSION: Dermatologists should be aware of these herbal products and their uses. Many of these products prescribed by alternative medicine physicians or purchased over the counter should be discontinued prior to dermatologic surgery to minimize the risk of surgical complications.


Assuntos
Procedimentos Cirúrgicos Dermatológicos , Complicações Intraoperatórias/induzido quimicamente , Fitoterapia , Complicações Pós-Operatórias/induzido quimicamente , Perda Sanguínea Cirúrgica , Dermatologia , Humanos , Hemorragia Pós-Operatória/induzido quimicamente
8.
Dig Dis Sci ; 46(7): 1526-32, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11478506

RESUMO

This study was done to examine the role of the vagus nerve in a model of gastric injury during endotoxemia. In conscious rats, lipopolysaccharide (LPS; 20 mg/kg i.p.) treatment for 5 hr prevented macroscopic gastric injury caused by acidified ethanol (150 mM HCl/50% ethanol). In addition, LPS enhanced gastric luminal fluid accumulation, decreased gastric mucosal blood flow (laser Doppler), and increased plasma gastrin levels (radioimmunoassay). Subdiaphragmatic truncal vagotomy, performed 7 days prior to LPS inhibited LPS-induced fluid accumulation, further reduced gastric mucosal blood flow following LPS, and augmented LPS-induced gastrin release compared to those in pyloroplasty controls. Atropine (1 mg/kg i.p.) prevented LPS-induced fluid accumulation but did not influence the effects of LPS on blood flow or gastrin release. Neither vagotomy nor atropine negated LPS-induced gastroprotection. This is the first report to examine the role of cholinergic nerves in the stomach during endotoxemia. The data indicate that LPS causes accumulation of gastric luminal fluid in part through its effects on cholinergic nerves. In contrast, the effects of vagotomy on blood flow and gastrin release following LPS involve a noncholinergic pathway. However, LPS-induced gastroprotection is independent of the vagus nerve.


Assuntos
Lipopolissacarídeos/farmacologia , Estômago/efeitos dos fármacos , Nervo Vago/fisiologia , Animais , Atropina/farmacologia , Endotoxemia/fisiopatologia , Feminino , Suco Gástrico/metabolismo , Mucosa Gástrica/irrigação sanguínea , Mucosa Gástrica/metabolismo , Gastrinas/sangue , Ratos , Ratos Sprague-Dawley , Estômago/inervação , Estômago/fisiologia , Vagotomia
9.
J Am Acad Dermatol ; 45(2): 187-95, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11464179

RESUMO

BACKGROUND: Isotretinoin is very frequently the drug of choice for the management of severe recalcitrant nodular acne. Recently, a new micronized and more bioavailable formulation of isotretinoin has been developed that permits once-daily administration in lower doses than usually used with standard isotretinoin (Accutane), regardless of whether it is taken with or without food. OBJECTIVE: Our purpose was to determine whether micronized isotretinoin and standard isotretinoin are clinically equivalent. METHODS: In this multicenter, double-blind, double-dummy study, 600 patients with severe recalcitrant nodular acne were treated with either 0.4 mg/kg of micronized isotretinoin once daily without food (n = 300) or 1.0 mg/kg per day of standard isotretinoin in two divided doses with food (n = 300). Lesion counts were monitored over 20 weeks. RESULTS: Both treatment groups in this well-controlled clinical trial experienced an equivalent reduction in the number of total nodules (facial plus truncal). In addition, an equivalent proportion of patients achieved 90% clearance of the total number of nodules. Both formulations had similar results for other efficacy variables. CONCLUSION: Once-daily use of the micronized and more bioavailable formulation of isotretinoin under fasted conditions is clinically equivalent to the standard twice-daily formulation under fed conditions in the treatment of severe recalcitrant nodular acne.


Assuntos
Acne Vulgar/tratamento farmacológico , Isotretinoína/administração & dosagem , Acne Vulgar/patologia , Adolescente , Adulto , Disponibilidade Biológica , Criança , Formas de Dosagem , Método Duplo-Cego , Esquema de Medicação , Feminino , Humanos , Isotretinoína/farmacocinética , Masculino , Pessoa de Meia-Idade , Comprimidos
10.
J Am Acad Dermatol ; 45(2): 196-207, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11464180

RESUMO

BACKGROUND: Isotretinoin is a very effective drug for treating severe recalcitrant nodular acne. A new micronized formulation of isotretinoin has been shown to be clinically equivalent to standard isotretinoin with improved bioavailability and minimal food effect. The safety profile of the micronized formulation has not been described previously. OBJECTIVE: The objective of this article is to report the incidence and intensity of adverse events found in a comparative, double-blind efficacy study that showed clinical equivalence of the new micronized formulation of isotretinoin and the standard isotretinoin formulation (Accutane). METHODS: Six hundred patients with severe recalcitrant nodular acne were treated with micronized isotretinoin (n = 300) under fasted conditions or standard isotretinoin (n = 300) under fed conditions. One cohort received single daily doses of 0.4 mg/kg of micronized isotretinoin without food and the other cohort received 1.0 mg/kg per day of standard isotretinoin in two divided doses with food. Adverse events were monitored during 20 weeks of drug therapy. RESULTS: The proportion of adverse events in most body systems was generally lower in patients receiving micronized isotretinoin than in those receiving standard isotretinoin. CONCLUSION: Micronized isotretinoin appears to have a safety profile similar to that of standard isotretinoin and to carry a lower risk of mucocutaneous events and hypertriglyceridemia.


Assuntos
Acne Vulgar/tratamento farmacológico , Isotretinoína/efeitos adversos , Acne Vulgar/patologia , Afeto/efeitos dos fármacos , Disponibilidade Biológica , Depressão/induzido quimicamente , Formas de Dosagem , Método Duplo-Cego , Esquema de Medicação , Cefaleia/induzido quimicamente , Humanos , Isotretinoína/administração & dosagem , Isotretinoína/farmacocinética , Lipídeos/sangue , Testes de Função Hepática , Mucosa/efeitos dos fármacos , Pele/efeitos dos fármacos , Comprimidos , Xeroftalmia/induzido quimicamente
11.
Nucleic Acids Res ; 28(20): 3918-25, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11024171

RESUMO

Histone acetylation alters the chromatin structure and activates the genes that are repressed by histone deacetylation. This investigation demonstrates that treating P3HR1 cells with trichostatin A (TSA) activates the Epstein-Barr virus (EBV) lytic cycle, allowing the virus to synthesize three viral lytic proteins-Rta, Zta and EA-D. Experimental results indicate that TSA and 12-O:-tetradecanoylphorbol-13-acetate synergistically activate the transcription of BRLF1, an immediate-early gene of EBV. Chromatin immunoprecipitation assay reveals that histone H4 at the BRLF1 promoter is acetylated after P3HR1 cells are treated with TSA, suggesting that histone acetylation activates BRLF1 transcription. Furthermore, results in this study demonstrate that mutation of a YY1-binding site in the BRLF1 promoter activates BRLF1 transcription 1.6- and 2.3-fold in P3HR1 cells and C33A cells, respectively. Real time PCR analysis reveals that the mutation also increases the histone acetylation level of the nucleosomes at the BRLF1 promoter 1. 64- and 3.08-fold in P3HR1 and C33A cells, respectively. Results presented herein suggest that histone deacetylation plays an important role in maintaining the viral latency and histone acetylation at the BRLF1 promoter allows the virus to express Rta and to activate the viral lytic cycle.


Assuntos
Regulação Viral da Expressão Gênica , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/fisiologia , Histonas/metabolismo , Proteínas Imediatamente Precoces/genética , Regiões Promotoras Genéticas/genética , Proteínas de Saccharomyces cerevisiae , Transativadores/genética , Acetilação/efeitos dos fármacos , Acetiltransferases/antagonistas & inibidores , Acetiltransferases/metabolismo , Sequência de Bases , Sítios de Ligação , Cromatina/química , Cromatina/efeitos dos fármacos , Cromatina/genética , Cromatina/metabolismo , Cicloeximida/farmacologia , Proteínas de Ligação a DNA/fisiologia , Sinergismo Farmacológico , Fatores de Ligação de DNA Eritroide Específicos , Regulação Viral da Expressão Gênica/efeitos dos fármacos , Genes Precoces/genética , Genoma Viral , Herpesvirus Humano 4/efeitos dos fármacos , Herpesvirus Humano 4/patogenicidade , Histona Acetiltransferases , Histonas/química , Histonas/efeitos dos fármacos , Humanos , Ácidos Hidroxâmicos/farmacologia , Mutação , Testes de Precipitina , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Viral/análise , RNA Viral/biossíntese , RNA Viral/genética , Elementos de Resposta/genética , Acetato de Tetradecanoilforbol/farmacologia , Fatores de Transcrição/fisiologia , Transcrição Gênica/efeitos dos fármacos , Ativação Transcricional/efeitos dos fármacos , Transfecção , Células Tumorais Cultivadas , Proteínas Virais , Replicação Viral/efeitos dos fármacos , Fator de Transcrição YY1
12.
Surgery ; 128(3): 422-8, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10965314

RESUMO

BACKGROUND: Bombesin prevents gastric injury primarily by the release of endogenous gastrin. Gastroprotection by exogenous gastrin is negated by nitric oxide synthase inhibition, which implicates a role for nitric oxide as a protective mediator. Because both endothelial and inducible isoforms of this enzyme can play a role in mucosal defense, this study was done to examine the contrasting effects of 2 nitric oxide synthase inhibitors on bombesin-induced gastroprotection. METHODS: Rats were given subcutaneous saline or bombesin (10-100 microg/kg) 30 minutes before they received a 1-mL orogastric bolus of acidified ethanol (150 mmol/L of hydrochloric acid/50% ethanol) and rats were killed 5 minutes later for assessment of macroscopic injury (mm(2)). Gastric mucosal blood flow was measured by laser Doppler. Endothelial, neural, and inducible nitric oxide synthase were assessed by using Western immunoblot. RESULTS: Bombesin decreased gastric mucosal damage, and dose-dependently increased blood flow when compared with saline-treated rats. Endothelial but not neural or inducible nitric oxide synthase immunoreactivity was increased by bombesin. In additional studies, intraperitoneal administration of N(G)-nitro-l-arginine methyl ester (l-NAME, 5-10 mg/kg), a nonselective nitric oxide synthase inhibitor, negated bombesin-induced gastroprotection and hyperemia, whereas the selective inducible inhibitor aminoguanidine (45 mg/kg) did not. Subcutaneous (SC) l-arginine (300 mg/kg), but not d-arginine, abolished the effects of l-NAME. CONCLUSIONS: Taken together, these data suggest that nitric oxide produced by the endothelial isoform of nitric oxide synthase plays an important role in mediating the gastroprotective and hyperemic actions associated with bombesin.


Assuntos
Bombesina/farmacologia , Inibidores Enzimáticos/farmacologia , Etanol/toxicidade , Mucosa Gástrica/patologia , Ácido Clorídrico/toxicidade , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico Sintase/antagonistas & inibidores , Fluxo Sanguíneo Regional/efeitos dos fármacos , Administração Oral , Animais , Arginina/farmacologia , Bombesina/antagonistas & inibidores , Etanol/administração & dosagem , Feminino , Mucosa Gástrica/irrigação sanguínea , Mucosa Gástrica/efeitos dos fármacos , Guanidinas/farmacologia , Ácido Clorídrico/administração & dosagem , Ratos , Ratos Sprague-Dawley
13.
Dermatol Surg ; 26(5): 441-5; discussion 445-6, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10816232

RESUMO

BACKGROUND: Filling substances have been used in dermatologic surgery for decades, but an ideal agent has yet to be discovered. Poly-(N-vinyl-2-pyrrolidone) is a hydrogel that has been used in medical settings for more than 50 years, but not as a cutaneous filling agent. OBJECTIVE: We investigated the intracutaneous injectability and tissue compatibility of this hydrogel in a rat model. Particular attention was paid to ease of injection through small needles, volume retention of the implant, clinical course, and histocompatibility. METHODS: The shaved backs of 12 anesthetized Sprague-Dawley rats were injected with the sterilized hydrogel and the rats closely observed. The rats were sacrificed in groups of four at 2, 4, and 12 weeks after implantation. Implant size was measured, volume calculated, and biopsies taken at each time interval. RESULTS: Poly-(N-vinyl-2-pyrrolidone) is easily injected through 30-gauge needles. All rats tolerated the implants well clinically. Histopathology revealed well-circumscribed implants with pseudoencapsulation, neoangiogenesis, and mixed inflammatory cells predominating at the periphery. Volume calculations revealed an average of 33% reduction at 4 weeks and 35% reduction at 12 weeks. CONCLUSION: Poly-(N-vinyl-2-pyrrolidone) is easy to inject intracutaneously and is well tolerated in the rat model. Short-term volume retention is good. Histopathology suggests a subclinical inflammatory reaction expected with implantation of a synthetic substance into the skin. Additional studies are necessary to investigate the continued persistence of the hydrogel and its long-term effects on surrounding tissue.


Assuntos
Materiais Biocompatíveis , Procedimentos Cirúrgicos Dermatológicos , Hidrogéis , Povidona , Dispositivos para Expansão de Tecidos , Animais , Modelos Animais de Doenças , Injeções Subcutâneas , Masculino , Projetos Piloto , Ratos , Ratos Sprague-Dawley , Pele/patologia
14.
Zhongguo Zhong Yao Za Zhi ; 25(9): 518-20, 2000 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-12516459

RESUMO

OBJECTIVE: To establish a rapid and convenient method for distinguishing genuine from sham of pearl powder as well as appraising its quality preliminarily. METHOD: Thermogravimetry and differential thermogravimetry. RESULT: The TG and DTG curves can be divided into two characteristic regions. The first step ranges from 250 to 380 degrees C with a weight loss of about 3%, resulting from the denaturalization and decomposition of organic matter in the powder; and the second step from 600 to 780 degrees C with a weight loss of about 40% resulting from the decomposition of calcium carbonate in the powder. CONCLUSION: According to the two characteristic regions on TG and DTG curves along with corresponding parameters, pearl powder can be appropriately authenticated. Being related directly to the contents of organic matter in pearl powder, the first step is an important criterion for quality appraisal.


Assuntos
Materia Medica/química , Moluscos/química , Animais , Análise Diferencial Térmica , Contaminação de Medicamentos , Temperatura Alta , Pós , Controle de Qualidade
15.
J Biol Chem ; 274(42): 30001-7, 1999 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-10514484

RESUMO

Composition of central nervous system lipoproteins affects the metabolism of lipoprotein constituents within the brain. The epsilon4 allele of apolipoprotein E (apoE) is a risk factor for Alzheimer's disease via an unknown mechanism(s). As glia are the primary central nervous system cell type that synthesize apoE, we characterized lipoproteins secreted by astrocytes from wild type (WT), apoE (-/-), and apoE transgenic mice expressing human apoE3 or apoE4 in a mouse apoE (-/-) background. Nondenaturing size exclusion chromatography demonstrates that WT, apoE3, and apoE4 astrocytes secrete particles the size of plasma high density lipoprotein (HDL) composed of phospholipid, free cholesterol, and protein, primarily apoE and apoJ. However, the lipid:apoE ratio of particles containing human apoE is significantly lower than WT. ApoE localizes across HDL-like particle sizes. ApoJ localizes to the smallest HDL-like particles. ApoE (-/-) astrocytes secrete little phospholipid or free cholesterol despite comparable apoJ expression, suggesting that apoE is required for normal secretion of astrocyte lipoproteins. Further, particles were not detected in apoE (-/-) samples by electron microscopy. Nondenaturing immunoprecipitation experiments indicate that apoE and apoJ reside predominantly on distinct particles. These studies suggest that apoE expression influences the unique structure of astrocyte lipoproteins, a process further modified by apoE species.


Assuntos
Apolipoproteínas E/genética , Astrócitos/metabolismo , Lipoproteínas/metabolismo , Animais , Astrócitos/ultraestrutura , Células Cultivadas , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Humanos , Lipoproteínas/isolamento & purificação , Lipoproteínas/ultraestrutura , Camundongos , Camundongos Transgênicos , Microscopia Eletrônica
16.
J Bacteriol ; 181(16): 5060-7, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10438779

RESUMO

A 37-kb DNA fragment containing five fengycin synthetase genes, including fenC, fenD, fenE, fenA, and fenB, was cloned and sequenced. Among these genes, fenC encodes a fengycin synthetase 2,560 amino acids long with an estimated molecular mass of 287 kDa. This protein contains two amino acid activation modules, FenC1 and FenC2, which activate L-glutamic acid and L-ornithine, respectively. Primer extension, using mRNA isolated from the log-phase cells, identified a transcription start site located 86 nucleotides upstream from the initiation codon of fenC, implying that a promoter is located upstream from the start site. Primer extension using total RNA isolated from stationary-phase cells also identified a transcription start site located 61 nucleotides upstream from the initiation codon of fenC. Gene fusion studies demonstrated that in nHA medium, the cells transcribe the fengycin synthetase genes at two different stages of cell growth. The promoter is active during the log phase, and the activity reaches the highest level during the late log phase. The activity decreases sharply but is maintained at a low level for approximately 24 h after cells enter the early stationary phase. The results of this investigation also suggest that the transcription of fenC is positively regulated during the late log phase. Results presented herein provide further insight into fengycin synthesis by B. subtilis F29-3.


Assuntos
Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Isoenzimas/genética , Peptídeo Sintases/genética , Adenina/metabolismo , Sequência de Bases , Domínio Catalítico , Clonagem Molecular , Cosmídeos , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Isoenzimas/metabolismo , Dados de Sequência Molecular , Mutagênese Insercional , Óperon , Peptídeo Sintases/metabolismo , Análise de Sequência de DNA , Especificidade por Substrato , Transcrição Gênica
17.
Br J Pharmacol ; 127(5): 1075-82, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10455251

RESUMO

Efforts to define precisely the role of 5-HT2B receptors in normal and disease processes have been hindered by the absence of selective antagonists. To address this deficiency, we developed a series of naphthylpyrimidines as potentially useful 5-HT2B receptor antagonists. RS-127445 (2-amino-4-(4-fluoronaphth-1-yl)-6-isopropylpyrimidine) was found to have nanomolar affinity for the 5-HT2B receptor (pKi = 9.5+/-0.1) and 1,000 fold selectivity for this receptor as compared to numerous other receptor and ion channel binding sites. In cells expressing human recombinant 5-HT2B receptors, RS-127445 potently antagonized 5-HT-evoked formation of inositol phosphates (pK(B) = 9.5+/-0.1) and 5-HT-evoked increases in intracellular calcium (pIC50 = 10.4+/-0.1). RS-127445 also blocked 5-HT-evoked contraction of rat isolated stomach fundus (pA2 = 9.5+/-1.1) and (+/-)alpha-methyl-5-HT-mediated relaxation of the rat jugular vein (pA2 = 9.9+/-0.3). RS-127445 had no detectable intrinsic activity in these assays. In rats, the fraction of RS-127445 that was bioavailable via the oral or intraperitoneal routes was 14 and 60% respectively. Intraperitoneal administration of RS-127445 (5 mg kg(-1)) produced plasma concentrations predicted to fully saturate accessible 5-HT2B receptors for at least 4 h. In conclusion, RS-127445 is a selective, high affinity 5-HT2B receptor antagonist suitable for use is vivo. The therapeutic potential of this molecule is being further evaluated.


Assuntos
Pirimidinas/farmacologia , Receptores de Serotonina/efeitos dos fármacos , Antagonistas da Serotonina/farmacologia , Animais , Células CHO , Cálcio/metabolismo , Cricetinae , Humanos , Masculino , Contração Muscular/efeitos dos fármacos , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptor 5-HT2B de Serotonina , Vasodilatação/efeitos dos fármacos
18.
J Clin Invest ; 103(6): R15-R21, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10079115

RESUMO

The epsilon4 allele of apolipoprotein E (apo E) is associated with an increased risk for developing Alzheimer's disease (AD). This may be due to interactions between apo E and the amyloid-beta protein (Abeta). To assess the effects of human apo E isoforms on Abeta deposition in vivo, we bred apo E3 and apo E4 hemizygous (+/-) transgenic mice expressing apo E by astrocytes to mice homozygous (+/+) for a mutant amyloid precursor protein (APPV717F) transgene that develop age-dependent AD neuropathology. All mice were on a mouse apo E null (-/-) background. By nine months of age, APPV717F+/-, apo E-/- mice had developed Abeta deposition, and, as reported previously, the quantity of Abeta deposits was significantly less than that seen in APPV717F+/- mice expressing mouse apo E. In contrast to effects of mouse apo E, similar levels of human apo E3 and apo E4 markedly suppressed early Abeta deposition at nine months of age in APPV717F+/- transgenic mice, even when compared with mice lacking apo E. These findings suggest that human apo E isoforms decrease Abeta aggregation or increase Abeta clearance relative to an environment in which mouse apo E or no apo E is present. The results may have important implications for understanding mechanisms underlying the link between apo E and AD.


Assuntos
Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Apolipoproteínas E/biossíntese , Doença de Alzheimer/etiologia , Doença de Alzheimer/genética , Animais , Apolipoproteínas E/genética , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos , Mutação , Isoformas de Proteínas/biossíntese , Isoformas de Proteínas/genética , Proteínas Recombinantes/biossíntese
19.
J Neurochem ; 72(3): 1069-80, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10037478

RESUMO

The apolipoprotein E (apoE)-derived peptide (141-155)2 has a neurotoxic effect, implying that apoE itself could be a source of toxicity in Alzheimer's disease brain. We characterized the toxicity of this peptide on superior cervical ganglion (SCG) neurons and compared the death with the apoptotic death that occurs after nerve growth factor (NGF) deprivation in these cells. A dose of 10 microM apoE (141-155)2 resulted in the death of approximately 50% of the neurons within 24 h. Nuclear condensation and DNA fragmentation preceded the death. However, most inhibitors of NGF deprivation-induced death, including the caspase inhibitor Boc-aspartyl(O-methyl)fluoromethyl ketone and genetic deletion of bax-/-, had no effect on the toxicity. Inclusion of depolarizing levels of potassium did block the toxicity. Receptor-associated peptide (RAP), an antagonist for apoE receptors, did not protect cells in either SCG or hippocampal cultures. In addition, RAP had no effect on internalization of the apoE peptide. These data support the observation that apoE (141-155)2 is neurotoxic but suggest that the neurotoxicity is distinct from classical apoptosis or necrosis. Furthermore, these results indicate that the toxic effect may occur independently of members of the low-density lipoprotein receptor gene family.


Assuntos
Apolipoproteínas E/fisiologia , Apolipoproteínas E/toxicidade , Fragmentos de Peptídeos/toxicidade , Sequência de Aminoácidos , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Hipocampo/citologia , Hipocampo/efeitos dos fármacos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Camundongos , Dados de Sequência Molecular , Fosforilação , Potássio/fisiologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de LDL/fisiologia , Gânglio Cervical Superior/citologia , Gânglio Cervical Superior/efeitos dos fármacos
20.
J Pharmacol Exp Ther ; 287(3): 884-8, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9864268

RESUMO

Cannabinoid receptors couple to both Gs and Gi proteins and can consequently stimulate or inhibit the formation of cAMP. To test whether there is specificity among cannabinoid receptor agonists in activating Gs- or Gi-coupled pathways, the potency and intrinsic activity of various cannabinoid receptor ligands in stimulating or inhibiting cAMP accumulation were quantified. The rank order of potencies of cannabinoid receptor agonists in increasing or inhibiting forskolin-stimulated cAMP accumulation, in CHO cells expressing hCB1 receptors, was identical (HU-210 > CP-55,940 > THC > WIN-55212-2 > anandamide). However, the activities of these agonists were different in the two assays with anandamide and CP-55,940 being markedly less efficacious in stimulating the accumulation of cAMP than in inhibiting its formation. Studies examining the effects of forskolin on cannabinoid receptor mediated stimulation of adenyly cyclase also revealed differences among agonists in as much as forskolin enhanced the potency of HU-210 and CP-55,940 by approximately 100-fold but, by contrast, had no effect on the potency of WIN-55212-2 or anandamide. Taken together these findings demonstrate marked differences among cannabinoid receptor agonists in their activation of intracellular transduction pathways. This provides support for the emerging concept of agonist-specific trafficking of cellular responses and further suggests strategies for developing receptor agonists with increased therapeutic utility.


Assuntos
Inibidores de Adenilil Ciclases , Adenilil Ciclases/metabolismo , Receptores de Droga/agonistas , Animais , Ácidos Araquidônicos/farmacologia , Benzoxazinas , Células CHO , Colforsina , Cricetinae , AMP Cíclico/análise , Cicloexanóis/farmacologia , Dronabinol/análogos & derivados , Dronabinol/farmacologia , Endocanabinoides , Ativação Enzimática , Humanos , Morfolinas/farmacologia , Naftalenos/farmacologia , Alcamidas Poli-Insaturadas , Receptores de Canabinoides , Receptores de Droga/genética , Transdução de Sinais , Transfecção
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