Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Vox Sang ; 112(7): 671-677, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28836328

RESUMO

BACKGROUND: The band 3 macrocomplex (also known as the ankyrin-associated complex) on the red cell membrane comprises two interacting subcomplexes: a band 3/glycophorin A subcomplex, and a Rh/RhAG subcomplex. Glycophorin B (GPB) is a component of the Rh/RhAG subcomplex that is also structurally associated with glycophorin A (GPA). Expression of glycophorin B-A-B hybrid GP.Mur enhances band 3 expression and is associated with lower levels of Rh-associated glycoprotein (RhAG) and Rh polypeptides. The goal of this study was to determine whether GP.Mur influenced erythroid Rh/RhAG expression at the transcript level. MATERIALS AND METHODS: GP.Mur was serologically determined in healthy participants from Taitung County, Taiwan. RNA was extracted from the reticulocyte-enriched fraction of peripheral blood, followed by reverse transcription and quantitative PCR for RhAG, RhD and RhCcEe. RESULTS: Quantification by real-time PCR revealed significantly fewer RhAG and RhCcEe transcripts in the reticulocytes from subjects with homozygous GYP*Mur. Independent from GYP.Mur, both RhAG and RhD transcript levels were threefold or higher than that of RhCcEe. Also, in GYP.Mur and the control samples alike, direct quantitative associations were observed between the transcript levels of RhAG and RhD, but not between that of RhAG and RhCcEe. CONCLUSION: Erythroid RhD and RhCcEe were differentially expressed at the transcript levels, which could be related to their different degrees of interaction or sensitivity to RhAG. Further, the reduction or absence of glycophorin B in GYP.Mur erythroid cells affected transcript expressions of RhAG and RhCcEe. Thus, GPB and GP.Mur differentially influenced Rh/RhAG expressions prior to protein translation.


Assuntos
Células Eritroides/metabolismo , Glicoforinas/genética , Sistema do Grupo Sanguíneo Rh-Hr/genética , Glicoforinas/sangue , Glicoforinas/metabolismo , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sistema do Grupo Sanguíneo Rh-Hr/sangue , Sistema do Grupo Sanguíneo Rh-Hr/metabolismo , Taiwan
2.
J Pharmacol Exp Ther ; 361(1): 68-86, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28138040

RESUMO

The ability of the N-methyl-d-aspartate receptor antagonist ketamine to alleviate symptoms in patients suffering from treatment-resistant depression (TRD) is well documented. In this paper, we directly compare in vivo biologic responses in rodents elicited by a recently discovered metabotropic glutamate (mGlu) 2/3 receptor antagonist 2-amino-3-[(3,4-difluorophenyl)sulfanylmethyl]-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylic acid (LY3020371) with those produced by ketamine. Both LY3020371 and ketamine increased the number of spontaneously active dopamine cells in the ventral tegmental area of anesthetized rats, increased O2 in the anterior cingulate cortex, promoted wakefulness, enhanced the efflux of biogenic amines in the prefrontal cortex, and produced antidepressant-related behavioral effects in rodent models. The ability of LY3020371 to produce antidepressant-like effects in the forced-swim assay in rats was associated with cerebrospinal fluid (CSF) drug levels that matched concentrations required for functional antagonist activity in native rat brain tissue preparations. Metabolomic pathway analyses from analytes recovered from rat CSF and hippocampus demonstrated that both LY3020371 and ketamine activated common pathways involving GRIA2 and ADORA1. A diester analog of LY3020371 [bis(((isopropoxycarbonyl)oxy)-methyl) (1S,2R,3S,4S,5R,6R)-2-amino-3-(((3,4-difluorophenyl)thio)methyl)-4-hydroxy-bicyclo[3.1.0]hexane-2,6-dicarboxylate (LY3027788)] was an effective oral prodrug; when given orally, it recapitulated effects of intravenous doses of LY3020371 in the forced-swim and wake-promotion assays, and augmented the antidepressant-like effects of fluoxetine or citalopram without altering plasma or brain levels of these compounds. The broad overlap of biologic responses produced by LY3020371 and ketamine supports the hypothesis that mGlu2/3 receptor blockade might be a novel therapeutic approach for the treatment of TRD patients. LY3020371 and LY3027788 represent molecules that are ready for clinical tests of this hypothesis.


Assuntos
Antidepressivos/uso terapêutico , Antagonistas de Aminoácidos Excitatórios/uso terapêutico , Ketamina/uso terapêutico , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Animais , Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Depressão/metabolismo , Depressão/psicologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Ketamina/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Receptores de Glutamato Metabotrópico/metabolismo , Receptores de Glutamato Metabotrópico/fisiologia , Receptores de N-Metil-D-Aspartato/metabolismo , Resultado do Tratamento
3.
J Pharmacol Exp Ther ; 351(2): 448-56, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25187432

RESUMO

Scopolamine produces rapid and significant symptom improvement in patients with depression, and most notably in patients who do not respond to current antidepressant treatments. Scopolamine is a nonselective muscarinic acetylcholine receptor antagonist, and it is not known which one or more of the five receptor subtypes in the muscarinic family are mediating these therapeutic effects. We used the mouse forced-swim test, an antidepressant detecting assay, in wild-type and transgenic mice in which each muscarinic receptor subtype had been genetically deleted to define the relevant receptor subtypes. Only the M1 and M2 knockout (KO) mice had a blunted response to scopolamine in the forced-swim assay. In contrast, the effects of the tricyclic antidepressant imipramine were not significantly altered by gene deletion of any of the five muscarinic receptors. The muscarinic antagonists biperiden, pirenzepine, and VU0255035 (N-[3-oxo-3-[4-(4-pyridinyl)-1-piper azinyl]propyl]-2,1,3-benzothiadiazole-4-sulfonamide) with selectivity for M1 over M2 receptors also demonstrated activity in the forced-swim test, which was attenuated in M1 but not M2 receptor KO mice. An antagonist with selectivity of M2 over M1 receptors (SCH226206 [(2-amino-3-methyl-phenyl)-[4-[4-[[4-(3 chlorophenyl)sulfonylphenyl]methyl]-1-piperidyl]-1-piperidyl]methanone]) was also active in the forced-swim assay, and the effects were deleted in M2 (-/-) mice. Brain exposure and locomotor activity in the KO mice demonstrated that these behavioral effects of scopolamine are pharmacodynamic in nature. These data establish muscarinic M1 and M2 receptors as sufficient to generate behavioral effects consistent with an antidepressant phenotype and therefore as potential targets in the antidepressant effects of scopolamine.


Assuntos
Antidepressivos/farmacologia , Receptor Muscarínico M1/metabolismo , Receptor Muscarínico M2/metabolismo , Escopolamina/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout/metabolismo , Atividade Motora/efeitos dos fármacos , Antagonistas Muscarínicos/farmacologia , Ratos , Ratos Sprague-Dawley , Natação/fisiologia
4.
Pulm Pharmacol Ther ; 27(1): 17-28, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23518214

RESUMO

BACKGROUND AND PURPOSE: Pulmonary fibrosis (PF) is a progressing lung injury initiated by pulmonary inflammation (PI). Bleomycin (BLM) is the most common pathogenesis of PF through early PI and extensive extracellular matrix deposition. This study is aimed to determine whether NO-releasing KMUP-1 inhibits PI and PF, and if so, the benefits of KMUP-1S resulted from simvastatin (SIM)-bonding to KMUP-1. EXPERIMENT APPROACH: C57BL/6 male mice were intra-tracheally administered BLM (4 U/kg) at day 0. KMUP-1 (1-5 mg/kg), KMUP-1S (2.5 mg/kg), SIM (5 mg/kg), Plus (KMUP-1 2.5 mg/kg + SIM 2.5 mg/kg), and clarithromycin (CAM, 10 mg/kg) were orally and daily administered for 7 and 28 days, respectively, to mice, sacrificed at day-7 and day-28 to isolate the lung tissues, for examining the inflammatory and fibrotic signaling and measuring the cell population and MMP-2/MMP-9 activity in broncholaveolar lavage fluid (BAL). KEY RESULTS: KMUP-1 and KUP-1S significantly decreased neutrophil counts in BAL fluid. Fibroblastic foci were histologically assessed by H&E and Masson's trichrome stain and treated with KMUP-1 and references. Lung tissues were determined the contents of collagen and the expressions of TGF-ß, α-SMA, HMGB1, CTGF, eNOS, p-eNOS, RhoA, Smad3, p-Smad3, MMP-2 and MMP-9 by Western blotting analyses, respectively. These changes areregulated by NO/cGMP and inhibited by various treatments. KMUP-1 and KMUP-1S predominantly prevented HMGB1/MMP-2 expression at day-7 and reduced TGF-ß/phosphorylated Smad3 and CTGF at day-28. CONCLUSIONS AND IMPLICATIONS: KMUP-1 and KMUP-S restore eNOS, inhibit iNOS/ROCKII/MMP-2/MMP-9, attenuate histologic collagen disposition and reduce BALF inflammatory cells, potentially useful for the treatment of BLM-lung PF.


Assuntos
Piperidinas/farmacologia , Pneumonia/tratamento farmacológico , Fibrose Pulmonar/tratamento farmacológico , Sinvastatina/farmacologia , Xantinas/farmacologia , Animais , Bleomicina/toxicidade , Western Blotting , Líquido da Lavagem Broncoalveolar , Claritromicina/farmacologia , Modelos Animais de Doenças , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Piperidinas/administração & dosagem , Piperidinas/química , Pneumonia/patologia , Fibrose Pulmonar/patologia , Transdução de Sinais/efeitos dos fármacos , Sinvastatina/administração & dosagem , Sinvastatina/química , Fatores de Tempo , Xantinas/administração & dosagem , Xantinas/química
5.
Int J Obes (Lond) ; 37(8): 1064-70, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23207405

RESUMO

BACKGROUND: The intake of a Western diet enriched in animal fat has been shown to be a major risk factor for Type 2 diabetes and obesity. Previous rodent studies have indicated that these conditions may be triggered by the accumulation of the sphingolipid ceramide in insulin-sensitive tissues. However, data are lacking in this regard from both humans and non-human primates. OBJECTIVE: Here we have investigated the relationship between plasma ceramides and metabolic syndrome in Rhesus macaques fed a high-fat and high-fructose (HFFD) 'western' diet. METHODS: We investigated this relationship in cohorts of monkeys fed a HFFD for a period of 8 months to 5 years. Animals were classified as control, pre-diabetic or diabetic based on fasting plasma parameters and insulin sensitivity. RESULTS: HFFD treatment produced significant increases in body weight and body fat and also resulted in a decline in insulin sensitivity. In parallel to the reduction in insulin sensitivity, significant increases in both plasma ceramide and dihydroceramide levels were observed, which further increased as animals progressed to the diabetic state. Plasma levels of the rare sphingolipid C18:0 deoxysphinganine, a marker of increased metabolic flux through serine palmitoyl transferase (SPT), were also elevated in both pre- and diabetic animals. Furthermore, plasma serine levels were significantly elevated in diabetic monkeys, which may indicate a shift in SPT substrate selectivity from serine to alanine or glycine. In contrast, branch chain amino acids were unchanged in pre-diabetic non-human primates, and only plasma valine levels were elevated in diabetic animals. CONCLUSION: Together, these data indicate that HFFD induces de novo synthesis of ceramides in non-human primates, and that increased production of plasma ceramides is significantly correlated with the decline in insulin sensitivity.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Dieta Hiperlipídica/efeitos adversos , Síndrome Metabólica/sangue , Obesidade/sangue , Serina C-Palmitoiltransferase/sangue , Esfingolipídeos/sangue , Animais , Biomarcadores/sangue , Ceramidas/sangue , Diabetes Mellitus Tipo 2/etiologia , Modelos Animais de Doenças , Progressão da Doença , Frutose/efeitos adversos , Resistência à Insulina , Macaca mulatta , Masculino , Síndrome Metabólica/etiologia , Obesidade/complicações , Fatores de Risco , Valina/sangue
6.
J Formos Med Assoc ; 100(4): 274-6, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11393128

RESUMO

We report a genetic carrier of multiple endocrine neoplasia type 2A (MEN 2A) who underwent prophylactic total thyroidectomy. The asymptomatic carrier of MEN 2A, an 8-year-old Taiwanese girl, was admitted for early thyroidectomy. Preoperative basal plasma concentrations of calcitonin and intact parathyroid hormone, and urine vanillylmandelic acid excretion, were normal. Ultrasonography of the thyroid was also normal. Pathology did not reveal any gross lesion but C-cell hyperplasia of the thyroid gland was found microscopically. Prophylactic total thyroidectomy is encouraged and is justified during the first decade of life for MEN 2A carriers.


Assuntos
Neoplasia Endócrina Múltipla Tipo 2a/cirurgia , Tireoidectomia , Criança , Feminino , Heterozigoto , Humanos , Neoplasia Endócrina Múltipla Tipo 2a/genética , Neoplasia Endócrina Múltipla Tipo 2a/patologia
7.
J Chromatogr Sci ; 39(12): 513-20, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11767239

RESUMO

A set of 17,600 samples belonging to our compound collection is selectively examined by liquid chromatography with UV, evaporative light scattering, and mass spectrometric detection methods. At least 70% of this set consists of pure samples with the expected structures. Subsequent studies by flow injection mass spectrometry show that this value is a conservative estimate and that the actual percentage of pure and correct compounds is close to 80%. Because this is the first time that sample quality information becomes available on such a large scale for the compound collection, it offers an opportunity to perform chemi-informatic studies for which structural integrity is essential. Results of these studies can be used to improve the selection of compounds for screening and evaluate the quality of compounds from particular sources.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Preparações Farmacêuticas/análise , Análise de Injeção de Fluxo , Luz , Espectrometria de Massas , Espectrofotometria Ultravioleta
8.
Anal Sci ; 17(4): 527-32, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11990571

RESUMO

For human urine beryllium (Be), each sample (500 microl) was diluted (1+1) with Nash reagent (containing 0.2% (v/v) acetylacetone and 2.0 M ammonium acetate buffer at pH 6.0) and then a 20-microl volume of Triton X-100 (0.4%, v/v) aqueous solution was added. An aliquot (10 microl) of the diluted urine mixture was introduced into a graphite cuvette and was atomized according to a temperature program. The method detection limit (MDL, 3sigma) for Be was 0.37 microg/l in the undiluted urine sample and the calibration graph was linear up to 65.0 microg/l. Calibration graphs were prepared by the standard addition method. Accuracies of 98.6-102% were obtained when testing standard reference material (SRM 2670) freeze dried human urine samples. Precision (relative standard deviation, RSD) for urine Be was < or = 2.3% (withinrun, n = 5) and was < or = 3.0% (between-run, n = 3). For human urine and serum selenium (Se), samples (100 microl) were diluted with HNO3 (0.2%, v/v) to make a (1+1) dilution for urine analysis or a (1+4) dilution for serum analysis. An additional aliquot (10 microl) of Triton X-100 (0.1%, v/v) was added to each 200 microl of (1+1) diluted urine (or 20 microl of the Triton X-100 was added to each 500 microl of (1+4) diluted serum) sample. After the diluted sample mixture (10 microl) was introduced into a graphite cuvette, the corresponding chemical modifier (10 microl, containing Ni2+ + Pd + NH4NO3 in HNO3 (0.2%, v/v)) was added to it and the mixture was atomized. The MDL (3sigma) for Se in urine and in serum was 4.4 and 21.4 microg/l in undiluted sample, respectively, and the calibration graphs were linear up to 150 and 400 microg/l. Accuracies of urine Se were 98.9 - 99.4% by testing SRM 2670 (NIST) urine standards with RSD (between-run, n = 3) within 2.9%; and that of serum Se was 97.2% when testing a certified second-generation human serum (No. 29, #664) with RSD (between-run, n = 3) of 1.4%. The proposed method can be applied easily, directly, and accurately to the measurement of Be and Se in real samples (including six urine Se and four serum Se from patients of Blackfoot Disease in Taiwan).


Assuntos
Berílio/urina , Grafite/metabolismo , Temperatura Alta , Selênio/sangue , Selênio/urina , Espectrofotometria Atômica/instrumentação , Espectrofotometria Atômica/métodos , Humanos , Doenças Vasculares Periféricas/diagnóstico
9.
J Formos Med Assoc ; 99(9): 721-5, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11000737

RESUMO

Intracortical osteosarcoma is the rarest anatomic variation of osteosarcoma. There have been only 12 cases reported in the English-language literature. We present a case of osteosarcoma in an 18-year-old Taiwanese man that originated within the cortex of the tibial diaphysis. The initial radiograph revealed a lytic mass confined to the cortex, mimicking a benign bone lesion. Histopathologic examination of the biopsy specimen showed an osteoblastic osteosarcoma mingled with some fibroblastic foci. He underwent en bloc resection, and a metallic prosthetic intercalary stem was used to replace the larger bone defect. Adjuvant chemotherapy was administered before and after the operation. He was free of disease during 40 months of follow-up. A review of all reported cases of intracortical osteosarcoma revealed that the initial method of treatment plays an important role in local recurrence and distant metastasis. Local excision and curettage leads to the worst results. The outcomes of more recently reported cases have improved because of early awareness of the possibility of malignancy and advances in chemotherapy. However, whether patients with intracortical osteosarcoma have a different prognosis from those with conventional osteosarcoma cannot be determined, because of the small number of intracortical osteosarcoma cases available for analysis.


Assuntos
Neoplasias Ósseas/patologia , Osteossarcoma/patologia , Adolescente , Neoplasias Ósseas/cirurgia , Humanos , Masculino , Osteossarcoma/cirurgia
10.
Bioorg Med Chem ; 8(3): 601-15, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10732977

RESUMO

This paper describes the structure activity relationships of a new class of cytomegalovirus DNA polymerase inhibitors having two aryl groups joined by an acyloxyamidine linker. Examination of a series of analogues in which the terminal groups are varied revealed a very narrow SAR around the 2,4-dichlorophenyl group of the lead compound, but a variety of replacements for the benzothiazole ring are compatible with activity. The most notable of these is the isoxazole ring of compound 78, which provides a 30-fold enhancement in potency compared to the lead compound. We also describe the design, synthesis and evaluation of 10 analogues in which the acyloxyamidine linker is modified or replaced by an isosteric group. Structure-activity relationship studies identified the linker -NH2 group as a critical pharmacophoric element. Ab initio molecular orbital calculations combined with qualitative estimates of steric interaction energies suggest that the lowest energy conformations of the acyloxyamidine linker are characterized by an extended planar CAr-C=N-O-C arrangement and either a syn-periplanar or anti-periplanar N-O-C-C(Ar') arrangement. Only the anti-periplanar conformation was observed in the crystal structures of three acyloxyamidines. The most active of the linker-modified compounds designed on the basis of these studies is the amidine carbamate 20, which is approximately one-third as potent in the cytomegalovirus DNA polymerase inhibition assay as the comparator acyloxyamidine 53. The activity of 20 suggests that acyloxyamidines may bind to the cytomegalovirus DNA polymerase via an anti-periplanar conformation similar to that observed in the crystal structure of acyloxyamidine 36.


Assuntos
Amidinas/química , Amidinas/farmacologia , Citomegalovirus/enzimologia , Inibidores da Síntese de Ácido Nucleico , Reagentes de Ligações Cruzadas/química , Reagentes de Ligações Cruzadas/farmacologia , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Hidrocarbonetos Aromáticos/química , Hidrocarbonetos Aromáticos/farmacologia , Concentração Inibidora 50 , Modelos Químicos , Modelos Moleculares , Conformação Molecular , Contagem de Cintilação , Relação Estrutura-Atividade , Termodinâmica
12.
J Pharm Sci ; 88(7): 705-8, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10393568

RESUMO

PNU-107859, an important representative structure in a novel class of matrix metalloproteinases (MMP) inhibitors known as thiadiazoles, was found to be quickly eliminated from rats. A major metabolite (approximately 10% of total dose) was found to be present in the bile of rats. The metabolite in question was isolated and purified from the bile fluids collected from six cannulated rats. From a total of approximately 75 mg of PNU-107859 administered to rats, 3.3 mg of the metabolite was recovered. The NMR and mass spectrometry results indicated that the metabolite is a glucuronide conjugate (1-deoxy-1beta-substituted D-glucopyranosiduronic acid) of the intact drug. Furthermore, the UV, MS, and NMR data established that the conjugate is located at the nitrogen alpha to the thiocarbonyl of the thiadiazole ring.


Assuntos
Bile/metabolismo , Inibidores de Metaloproteinases de Matriz , Inibidores de Proteases/metabolismo , Tiadiazóis/metabolismo , Ureia/análogos & derivados , Animais , Cromatografia Líquida de Alta Pressão , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Ratos , Ratos Sprague-Dawley , Ureia/metabolismo
13.
Bioorg Med Chem Lett ; 9(9): 1311-6, 1999 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-10340620

RESUMO

Structure-activity studies on the oxytocin antagonist 1 (L-371,257; Ki = 9.3 nM) have led to the identification of a related series of compounds containing an ortho-trifluoroethoxyphenylacetyl core which are orally bioavailable and have significantly improved potency in vitro and in vivo, e.g., compound 8 (L-374,943; Ki = 1.4 nM).


Assuntos
Oxazinas/síntese química , Oxazinas/farmacocinética , Ocitocina/antagonistas & inibidores , Piperidinas/síntese química , Piperidinas/farmacocinética , Animais , Benzoxazinas , Linhagem Celular , Humanos , Concentração Inibidora 50 , Cinética , Ratos , Relação Estrutura-Atividade
14.
Antimicrob Agents Chemother ; 43(4): 925-9, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10103201

RESUMO

Resistance to lincomycin and clindamycin in the clinical isolate Enterococcus faecium HM1025 is due to a ribosomal methylase encoded by an ermAM-like gene and the plasmid-mediated inactivation of these antibiotics. We have cloned and determined the nucleotide sequence of the gene responsible for the inactivation of lincosamides, linB. This gene encodes a 267-amino-acid lincosamide nucleotidyltransferase. The enzyme catalyzes 3(5'-adenylation) (the adenylation of the hydroxyl group in position 3 of the molecules) of lincomycin and clindamycin. Expression of linB was observed in both Escherichia coli and Staphylococcus aureus. The deduced amino acid sequence of the enzyme did not display any significant homology with staphylococcal nucleotidyltransferases encoded by linA and linA' genes. Sequences homologous to linB were found in 14 other clinical isolates of E. faecium, indicating the spread of the resistance trait in this species.


Assuntos
Antibacterianos/metabolismo , Enterococcus faecium/metabolismo , Hidrolases/metabolismo , Macrolídeos , Antibacterianos/farmacologia , Clindamicina/metabolismo , Clindamicina/farmacologia , Resistência Microbiana a Medicamentos/fisiologia , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/enzimologia , Enterococcus faecium/genética , Humanos , Hidrolases/genética , Lincomicina/metabolismo , Lincomicina/farmacologia , Lincosamidas , Dados de Sequência Molecular , Nucleotidiltransferases/biossíntese
15.
J Med Chem ; 41(12): 2146-63, 1998 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-9622556

RESUMO

The previously reported oxytocin antagonist L-371,257 (2) has been modified at its acetylpiperidine terminus to incorporate various pyridine N-oxide groups. This modification has led to the identification of compounds with improved pharmacokinetics and excellent oral bioavailability. The pyridine N-oxide series is exemplified by L-372,662 (30), which possessed good potency in vitro (Ki = 4.1 nM, cloned human oxytocin receptor) and in vivo (intravenous AD50 = 0.71 mg/kg in the rat), excellent oral bioavailability (90% in the rat, 96% in the dog), good aqueous solubility (>8.5 mg/mL at pH 5.2) which should facilitate formulation for iv administration, and excellent selectivity against the human arginine vasopressin receptors. Incorporation of a 5-fluoro substituent on the central benzoyl ring of this class of oxytocin antagonists enhanced in vitro and in vivo potency but was detrimental to the pharmacokinetic profiles of these compounds. Although lipophilic substitution around the pyridine ring of compound 30 gave higher affinity in vitro, such substituents were a metabolic liability and caused shortfalls in vivo. Two approaches to prevent this metabolism, addition of a cyclic constraint and incorporation of trifluoromethyl groups, were examined. The former approach was ineffective because of metabolic hydroxylation on the constrained ring system, whereas the latter showed improvement in plasma pharmacokinetics in some cases.


Assuntos
Oxazinas , Piridinas , Receptores de Ocitocina/antagonistas & inibidores , Administração Oral , Animais , Disponibilidade Biológica , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Cães , Feminino , Humanos , Rim/citologia , Rim/embriologia , Rim/metabolismo , Fígado/metabolismo , Masculino , Espectrometria de Massas , Oxazinas/síntese química , Oxazinas/metabolismo , Oxazinas/farmacocinética , Oxazinas/farmacologia , Gravidez , Piridinas/síntese química , Piridinas/metabolismo , Piridinas/farmacocinética , Piridinas/farmacologia , Ratos , Receptores de Ocitocina/metabolismo , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/metabolismo , Espectrofotometria Ultravioleta , Contração Uterina/efeitos dos fármacos , Útero/efeitos dos fármacos , Útero/fisiologia
16.
Bioorg Med Chem Lett ; 8(21): 3081-6, 1998 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-9873680

RESUMO

Structure-activity studies on the oxytocin antagonist 1 (L-371,257) have identified a new series of high affinity, receptor-selective OT antagonists in which the N-acetyl-4-piperidinyl ether terminus in 1 has been replaced with a 1-(aryl)ethoxy group.


Assuntos
Oxazinas/farmacologia , Ocitocina/antagonistas & inibidores , Piperidinas/farmacologia , Administração Oral , Animais , Benzoxazinas , Disponibilidade Biológica , Feminino , Humanos , Ratos , Relação Estrutura-Atividade
17.
J Antibiot (Tokyo) ; 49(10): 1006-13, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8968394

RESUMO

This report describes the results of a biosynthesis study of marcfortine A (MA). We report here that MA is derived from methionine, tryptophan, lysine and two isoprene units, the latter two being derived from acetic acid. From the 13C enrichment pattern of the pipecolic acid moeity we further conclude that this unit is derived from lysine via alpha-ketoglutarate. Therefore, we have accounted for the biogenesis of every carbon atom of MA and established the biosynthetic pathway for the pipecolic acid moiety of MA.


Assuntos
Compostos Bicíclicos com Pontes/metabolismo , Indolizinas , Penicillium/metabolismo , Compostos de Espiro/metabolismo , Acetatos/metabolismo , Compostos Bicíclicos com Pontes/química , Isótopos de Carbono , Lisina/metabolismo , Espectroscopia de Ressonância Magnética , Metionina/metabolismo , Estrutura Molecular , Compostos de Espiro/química
19.
J Formos Med Assoc ; 93(11-12): 933-8, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7633197

RESUMO

To elucidate the ultrasonographic findings in papillary thyroid carcinoma and their relation to pathologic changes, 47 patients on whom thyroid ultrasonography had been performed and whose thyroid tissues were pathologically proven to be papillary thyroid carcinoma were studied. The ultrasonographic findings were reviewed and correlated with the pathologic changes. Fifty-three out of 94 thyroid lobes had papillary carcinoma. The ultrasonographic features of the affected thyroid lobes were hypoechoic in 46, isoechoic in 6 and hyperechoic in 1. The ultrasonographic texture of all 53 lesions was heterogeneous. The margin was clear in 11 lesions and unclear in 42. Cystic degeneration was found in 15 lesions. Discrete particles representative of microcalcifications were found in 25 lesions. Halo signs were found in 7 lesions. Lymph node enlargement was detected in 4 cases. The sensitivity and specificity of each ultrasonic finding in predicting the respective pathologic feature were: unclear margin for tumor invasion, 84% and 31%; cystic degeneration for cysts, 42% and 79%; discrete particles for microcalcification, 50% and 52%; halo sign for total encapsulation, 42% and 88%; and lymph node enlargement for lymph node metastasis, 18% and 100%, respectively. These data suggest that ultrasonographic findings in papillary carcinoma were usually hypoechoic and heterogeneous. An unclear margin in sonography is fairly sensitive for the prediction of tumor invasion.


Assuntos
Carcinoma Papilar/diagnóstico por imagem , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Ultrassonografia
20.
J Formos Med Assoc ; 92(12): 1111-3, 1993 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7911364

RESUMO

A 47-year-old Taiwanese man with a long-standing history of left chronic tuberculous empyema complained of having a painful swelling over the left lower chest wall for a four-month period. Suspecting acute exaggeration of infection, open drainage was performed. Multiple yellow-grayish, fragile substances protruding from the calcified empyema wall were found. Pathologic studies revealed a diffuse large B-cell non-Hodgkin's lymphoma and removal of the tumors en bloc, with the empyema peel and part of the chest wall, was performed two weeks later. The postoperative course was smooth, but the patient refused further chemotherapy. He was well, without local recurrence or metastasis after nine months of follow-up. Malignant lymphoma developing from long-standing pyothorax is very rare, and has been reported only in Japanese series. The relationship between chronic pyothorax and the subsequent development of malignant lymphoma is discussed and the literature is reviewed.


Assuntos
Empiema Pleural/complicações , Linfoma de Células B/etiologia , Linfoma Difuso de Grandes Células B/etiologia , Neoplasias Pleurais/etiologia , Doença Crônica , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...