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1.
ESMO Open ; 7(5): 100573, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36084396

RESUMO

BACKGROUND: We conducted a phase I, multicenter, open-label, dose-finding, and expansion study to determine the safety and preliminary efficacy of eprenetapopt (APR-246) combined with pembrolizumab in patients with advanced/metastatic solid tumors (ClinicalTrials.gov NCT04383938). PATIENTS AND METHODS: For dose-finding, requirements were non-central nervous system primary solid tumor, intolerant to/progressed after ≥1 line of treatment, and eligible for pembrolizumab; for expansion: (i) gastric/gastroesophageal junction tumor, intolerant to/progressed after first-line treatment, and no prior anti-programmed cell death receptor-1 (PD-1)/programmed death-ligand 1 (PD-L1) therapy; (ii) bladder/urothelial tumor, intolerant to/progressed after first-line cisplatin-based chemotherapy, and no prior anti-PD-1/PD-L1 therapy; (iii) non-small-cell lung cancer (NSCLC) with previous anti-PD-1/PD-L1 therapy. Patients received eprenetapopt 4.5 g/day intravenously (IV) on days 1-4 with pembrolizumab 200 mg IV on day 3 in each 21-day cycle. Primary endpoints were dose-limiting toxicity (DLT), adverse events (AEs), and recommended phase II dose (RP2D) of eprenetapopt. RESULTS: Forty patients were enrolled (median age 66 years; range 27-85) and 37 received eprenetapopt plus pembrolizumab. No DLTs were reported and the RP2D for eprenetapopt in combination was 4.5 g/day IV on days 1-4. The most common eprenetapopt-related AEs were dizziness (35.1%), nausea (32.4%), and vomiting (29.7%). AEs leading to eprenetapopt discontinuation occurred in 2/37 patients (5.4%). In efficacy-assessable patients (n = 29), one achieved complete response (urothelial cancer), two achieved partial responses (NSCLC, urothelial cancer), and six patients had stable disease. CONCLUSIONS: The eprenetapopt plus pembrolizumab combination was well tolerated with an acceptable safety profile and showed clinical activity in patients with solid tumors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Quinuclidinas/uso terapêutico
2.
Science ; 259(5093): 343-6, 1993 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-17832347

RESUMO

The reaction between methane and oxygen over platinum and rhodium surfaces in metalcoated ceramic monoliths can be made to produce mostly hydrogen and carbon monoxide (greater than 90% selectivity for both) with almost complete conversion of methane and oxygen at reaction times as short as 10(-3) seconds. This process has great promise for conversion of abundant natural gas into liquid products such as methanol and hydrocarbons, which can be easily transported from remote locations. Rhodium was considerably superior to platinum in producing more H(2) and less H(2)O, which can be explained by the known chemistry and kinetics of reactants, intermediates, and products on these surfaces.

3.
J Thromb Haemost ; 15(2): 375-387, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27925685

RESUMO

Essentials Platelet transfusion suffers from availability, portability, contamination, and short shelf-life. SynthoPlate™ (synthetic platelet technology) can resolve platelet transfusion limitations. SynthoPlate™ does not activate resting platelets or stimulate coagulation systemically. SynthoPlate™ significantly improves hemostasis in thrombocytopenic mice dose-dependently. SUMMARY: Background Platelet transfusion applications face severe challenges, owing to the limited availability and portability, high risk of contamination and short shelf-life of platelets. Therefore, there is significant interest in synthetic platelet substitutes that can provide hemostasis while avoiding these issues. Platelets promote hemostasis by injury site-selective adhesion and aggregation, and propagation of coagulation reactions on their membranes. On the basis of these mechanisms, we have developed a synthetic platelet technology (SynthoPlate™) that integrates platelet-mimetic site-selective 'adhesion' and 'aggregation' functionalities via heteromultivalent surface decoration of lipid vesicles with von Willebrand factor-binding, collagen-binding and active platelet integrin glycoprotein (GP) IIb-IIIa-binding peptides. Objective To evaluate SynthoPlate for its effects on platelets and plasma in vitro, and for systemic safety and hemostatic efficacy in severely thrombocytopenic mice in vivo. Methods In vitro, SynthoPlate was evaluated with aggregometry, fluorescence microscopy, microfluidics, and thrombin and fibrin generation assays. In vivo, SynthoPlate was evaluated for systemic safety with prothrombin and fibrin assays on plasma, and for hemostatic effects on tail-transection bleeding time in severely thrombocytopenic (TCP) mice. Results SynthoPlate did not aggregate resting platelets or spontaneously promote coagulation in plasma, but could amplify the recruitment and aggregation of active platelets at the bleeding site, and thereby site-selectively enhance fibrin generation. SynthoPlate dose-dependently reduced bleeding time in TCP mice, to levels comparable to those in normal mice. SynthoPlate has a reasonable circulation residence time, and is cleared mostly by the liver and spleen. Conclusion The results demonstrate the promise of SynthoPlate as a synthetic platelet substitute in transfusion treatment of platelet-related bleeding complications.


Assuntos
Plaquetas/citologia , Substitutos Sanguíneos , Adesividade Plaquetária , Trombocitopenia/terapia , Animais , Tempo de Sangramento , Coagulação Sanguínea , Hemorragia , Hemostasia , Humanos , Luz , Camundongos , Microfluídica , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Transfusão de Plaquetas , Espalhamento de Radiação , Trombina/metabolismo
4.
Mucosal Immunol ; 9(6): 1559-1570, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27007673

RESUMO

Human noroviruses are a leading cause of gastroenteritis, and so, vaccine development is desperately needed. Elucidating viral mechanisms of immune antagonism can provide key insight into designing effective immunization platforms. We recently revealed that B cells are targets of norovirus infection. Because noroviruses can regulate antigen presentation by infected macrophages and B cells can function as antigen-presenting cells, we tested whether noroviruses regulate B-cell-mediated antigen presentation and the biological consequence of such regulation. Indeed, murine noroviruses could prevent B-cell expression of antigen presentation molecules and this directly correlated with impaired control of acute infection. In addition to B cells, acute control required MHC class I molecules, CD8+ T cells, and granzymes, supporting a model whereby B cells act as antigen presenting cells to activate cytotoxic CD8+ T cells. This immune pathway was active prior to the induction of antiviral antibody responses. As in macrophages, the minor structural protein VP2 regulated B-cell antigen presentation in a virus-specific manner. Commensal bacteria were not required for the activation of this pathway and ultimately only B cells were required for the clearance of viral infection. These findings provide new insight into the role of B cells in stimulating antiviral CD8+ T-cell responses.


Assuntos
Apresentação de Antígeno/imunologia , Linfócitos B/imunologia , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/virologia , Norovirus/fisiologia , Doença Aguda , Animais , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Antígenos de Superfície/metabolismo , Linfócitos B/metabolismo , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Microbioma Gastrointestinal , Humanos , Imunomodulação , Camundongos , Camundongos Knockout , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-27525192

RESUMO

BACKGROUND: An estimated 3.5 million Americans are chronically infected with hepatitis C virus (HCV). However, the majority are unaware of their HCV diagnosis and few are treated. New models are required to diagnose and link HCV infected patients to HCV care. This paper describes an innovative partnership between Sisters Together and Reaching (STAR), Inc., a community organization, and Johns Hopkins University (JHU), an academic institution, for the identification of HCV cases. METHODS: STAR and JHU identified a mutual interest in increasing hepatitis C screening efforts and launched an HCV screening program which was designed to enhance STAR's existing HIV efforts. STAR and JHU used the Bergen Model of Collaborative Functioning as theoretical framework for the partnership. We used descriptive statistics to characterize the study population and correlates of HCV antibody positivity were reported in univariable/multivariable logistic regression. RESULTS: From July 2014 to June 2015, 325 rapid HCV antibody tests were performed in community settings with 49 (15%) positive HCV antibody tests. 33 of the 49 HCV antibody positive individuals answered questions about their HCV testing history and 42% reported a prior positive result but were not engaged in care and 58% reported that they were unaware of their HCV status. In multivariable analysis, factors that were significantly associated with screening HCV antibody positive were increasing age (AOR: 1.06, 95% CI 1.02-1.10), male sex (AOR: 5.56, 95% CI 1.92-14.29), and history of injection drug use (AOR: 39.3, 95% CI 15.20-101.49). CONCLUSIONS: The community-academic partnership was successful in identifying individuals with hepatitis C infection through a synergistic collaboration. The program data suggests that community screening may improve the hepatitis C care continuum by identifying individuals unaware of their HCV status or aware of their HCV status but not engaged in care and linking them to care.

6.
Lab Anim ; 49(1): 10-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25117586

RESUMO

Current regulations emphasize that good husbandry practices allow animals to engage in species appropriate postural adjustments without touching the enclosure walls. This study evaluated the well-being of rats housed in a commercially available multilevel rat caging system, with or without access to the upper level of the caging. The evaluation methodologies included assessment of behavioral observations in the home cage, physiological assessment of metabolism and immune function, and determination of the affective state using a spatial cognitive bias assay. The study determined that rats that were provided access to the full multilevel cage during testing after initial restriction to the lower level of the cage demonstrated behavioral changes consistent with a positive affective state, while those with no changes to their housing situation had no significant differences in their affective states. Rats that were consistently housed with access restricted to the lower level of the cage exhibited a tendency to increased neutrophil:lymphocyte ratios as compared with those provided with access to all levels of the multilevel cage. There were no differences in body weight demonstrated between the experimental groups. Overall use of the cage space, as documented through analysis of behavioral observations in the home cage, demonstrated no significant differences in preferred location in the cage during the light or dark cycles, though rats with access to both levels of the cage were significantly more active during the light cycle. The results of this study suggest that the use of a multilevel caging system may improve the well-being of rats used in research.


Assuntos
Criação de Animais Domésticos/métodos , Bem-Estar do Animal , Abrigo para Animais , Ratos/fisiologia , Animais , Cognição , Emoções , Masculino , Distribuição Aleatória , Ratos/imunologia , Ratos Sprague-Dawley , Comportamento Espacial , Estresse Fisiológico
7.
Pharmacogenetics ; 2(5): 217-26, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1306121

RESUMO

Arylamine N-acetyltransferase catalyses the N-acetylation of primary arylamine and hydrazine drugs and chemicals. N-acetylation is subject to a polymorphism and humans can be categorized as either fast or slow acetylators according to their ability to N-acetylate polymorphic substrates in vivo. Previously, slow acetylation has been linked to four distinct polymorphic N-acetyltransferase (pnat) alleles each of which contains one or more point mutations within the coding region of the pnat gene. One new rare slow variant of pnat has been identified by cloning and sequencing the pnat DNA from an individual whose NAT phenotype was determined by in vivo acetylation of the polymorphic substrate sulphamethazine. This allele, designated S1c, differs from the wild type fast allele at nucleotide positions 341 and 803. A second new rare slow allotypic variant, designated S3, has been identified by resistance of the pnat specific DNA to digestion with the restriction enzymes Fok I and Bam HI. A method of genotyping individuals for the arylamine N-acetyltransferase (NAT) polymorphism is presented which correctly predicts the phenotype of greater than 95% (21 of 22) of individuals as measured by the extent of acetylation of sulphamethazine in urine. This refined genotyping method was applied to a clinical population of 48 Caucasians with classical or definite rheumatoid arthritis each receiving daily between 150 and 500 mg of the anti-rheumatic drug, D-penicillamine. There is no difference in the N-acetyltransferase phenotype of the individuals who developed proteinuria and the control group with no adverse effects.


Assuntos
Arilamina N-Acetiltransferase/genética , Polimorfismo Genético , Adulto , Idoso , Alelos , Arilamina N-Acetiltransferase/metabolismo , Sequência de Bases , Clonagem Molecular , DNA/genética , Amplificação de Genes , Genótipo , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Penicilamina , Reação em Cadeia da Polimerase , Proteinúria/induzido quimicamente , Proteinúria/enzimologia , Proteinúria/genética
8.
J Histochem Cytochem ; 44(9): 1059-67, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8773572

RESUMO

The N-acetyltransferase (NAT) phenotype is an important determinant of individual susceptibility to occupational bladder cancer. N-Acetyltransferases arc known to metabolize aromatic amine bladder carcinogens, but the functional significance of NAT expression in the target organ is unclear. To resolve this issue, polygonal antisera against purified recombinant enzymes and C-terminal peptides of human NAT Type 1 (NAT1) and Type 2 (NAT2) were generated. Western blot analysis of exfoliated cells from human urine, pig bladder homogenate, and human bladder tumor-derived cell lines showed that NAT1 was expressed in all three systems, whereas NAT2 did not appear to be expressed in the bladder. Immunohistochemical analysis of human bladder tumor sections indicated that well-differentiated tumor cells expressed NAT1, with the highest level of expression being found in the umbrella cells that line the bladder lumen. Poorly differentiated tumor regions appeared to express NAT1 at lower levels than did well-differentiated areas. These findings support the hypothesis that aromatic amines are metabolized in the bladder epithelium by NAT1.


Assuntos
Arilamina N-Acetiltransferase/metabolismo , Neoplasias da Bexiga Urinária/enzimologia , Bexiga Urinária/enzimologia , Sequência de Aminoácidos , Animais , Arilamina N-Acetiltransferase/química , Arilamina N-Acetiltransferase/imunologia , Biomarcadores Tumorais/metabolismo , Western Blotting , Carcinógenos/metabolismo , Epitélio/metabolismo , Humanos , Imuno-Histoquímica , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Proteínas Recombinantes/imunologia , Suínos , Células Tumorais Cultivadas , Bexiga Urinária/citologia
9.
J Histochem Cytochem ; 46(3): 291-300, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9487110

RESUMO

During glomerular development, subendothelial and -epithelial basement membrane layers fuse to produce the glomerular basement membrane (GBM) shared by endothelial cells and epithelial podocytes. As glomeruli mature, additional basement membrane derived from podocytes is spliced into the fused GBM and loose mesangial matrices condense. The mechanisms for GBM fusion, splicing, and mesangial matrix condensation are not known but might involve intermolecular bond formation between matrix molecules. To test for laminin binding sites, we intravenously injected mouse laminin containing alpha1-, beta1-, and gamma1-chains into 2-day-old rats. Kidneys were immunolabeled for fluorescence and electron microscopy with domain-specific rat anti-mouse laminin monoclonal antibodies (MAbs), which recognized only mouse and not endogenous rat laminin. Intense labeling for injected laminin was found in mesangial matrices and weaker labeling was seen in GBMs of maturing glomeruli. These patterns persisted for at least 2 weeks after injection. In control newborns receiving sheep IgG, no binding of injected protein was observed and laminin did not bind adult rat glomeruli. To assess which molecular domains might mediate binding to immature glomeruli, three proteolytic laminin fragments were affinity-isolated by MAbs and injected into newborns. These failed to bind glomeruli, presumably owing to enzymatic digestion of binding domains. Alternatively, stable incorporation may require multivalent laminin binding. We conclude that laminin binding sites are transiently present in developing glomeruli and may be functionally important for GBM assembly and mesangial matrix condensation.


Assuntos
Membrana Basal/metabolismo , Mesângio Glomerular/metabolismo , Laminina/metabolismo , Animais , Animais Recém-Nascidos , Membrana Basal/embriologia , Técnica Indireta de Fluorescência para Anticorpo , Mesângio Glomerular/embriologia , Camundongos , Microscopia Imunoeletrônica , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Fatores de Tempo
10.
Br J Pharmacol ; 105(2): 400-4, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1559130

RESUMO

1. Previous studies had shown that adenosine and adenine nucleotides including adenosine 5'-triphosphate (ATP) caused contraction of the rat colon muscularis mucosae via P1 and P2Y-purinoceptors respectively, and that the stable ATP analogue adenylyl 5'-(beta,gama- methylene)diphosphonate (AMPPCP) had an unexpected direct action on the P1-purinoceptors. The P1-purinoceptors have now therefore been further characterized by use of the adenosine analogues 5'-N-ethylcarboxamidoadenosine (NECA) and N6-cyclopropyladenosine (CPA) and the antagonist 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), which is selective for the A1 subtype. The P2-purinoceptor antagonist suramin was also used, to investigate the selectivity of the P2 agonists. 2. The order of potency of P1 agonists for contraction was CPA greater than NECA greater than AMPPCP greater than or equal to adenosine, and DPCPX (1 nM) caused greater than two fold shifts to the right of the log concentration-response curves for each of these agonists, although the shifts were not always parallel and Schild analysis of the inhibition of the effect of adenosine resulted in a plot with a slope greater than unity. These results indicate that the P1-purinoceptor mediating contraction is of the A1 subtype, as has been found in other tissues in which adenosine causes contraction. 3. The P2-purinoceptor antagonist suramin (300 microM) had no effect on the responses to adenosine or to AMPPCP, but abolished contractions induced by the related stable ATP analogue adenosine 5'-(alpha,beta-methylene)triphosphonate (AMPCPP). Contractions induced by ATP, which were not affected by DPCPX (10nM) alone, were only partially inhibited by suramin (300microM), revealing an A1 component to its action which could be blocked by DPCPX (10 nM).4. In conclusion, these results show that the rat colon muscularis mucosae possesses contractile A, receptors in addition to the previously characterized P2y receptors, and confirms our finding that the stable ATP analogue, AMPPCP, has an unexpected direct action on these Al receptors.


Assuntos
Colo/química , Receptores Purinérgicos/isolamento & purificação , Adenosina/análogos & derivados , Adenosina/farmacologia , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/farmacologia , Animais , Colo/efeitos dos fármacos , Colo/fisiologia , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Ratos , Ratos Endogâmicos , Receptores Purinérgicos/efeitos dos fármacos , Receptores Purinérgicos/fisiologia , Suramina/farmacologia
11.
Biochem Pharmacol ; 42(5): 1007-14, 1991 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-1872889

RESUMO

N-Acetyltransferase (NAT) isoenzymes are encoded at two loci. One locus encodes an NAT which is expressed widely in tissues, does not vary amongst human individuals and is termed monomorphic NAT (mNAT). The second locus encodes an NAT which is termed polymorphic NAT (pNAT), has a distinct tissue distribution and is responsible for the difference in ability between individuals in acetylating certain arylamine (e.g. sulphamethazine) and hydrazine (e.g. isoniazid) drugs which are polymorphic substrates. We describe a simple DNA based method for genotyping individuals for pNAT. The 'fast' NAT allele (F1) and the three 'slow' alleles (S1, S2 and S3) can be distinguished by using PCR with oligonucleotide primers specific for pNAT followed by restriction enzyme digestion of the amplified product. Heterozygotes are easily identified. The genotype of individual Caucasians compares well with the extent of acetylation of sulphamethazine. The allele distribution of the Caucasian population described here differs from that reported after Southern blot analysis of a Japanese population (Deguchi et al., J Biol Chem 265: 12757-12760, 1990). The most frequent allele at the polymorphic nat locus in Caucasians, S1, is absent in the Japanese population. This difference between the two populations is likely to be the basis of the known interethnic variation in acetylator phenotype frequencies.


Assuntos
Alelos , Arilamina N-Acetiltransferase/genética , Polimorfismo Genético , Acetilação , Adulto , Arilamina N-Acetiltransferase/metabolismo , Sequência de Bases , Genótipo , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fenótipo , Reação em Cadeia da Polimerase , Sulfametazina/metabolismo
12.
Biochem Pharmacol ; 50(5): 697-703, 1995 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-7669073

RESUMO

Arylamine N-acetyltransferase (NAT2) catalyses the N-acetylation of primary arylamine and hydrazine drugs and chemicals. N-Acetylation is subject to polymorphism, and humans can be categorized as either fast or slow acetylators according to their ability to N-acetylate certain arylamine substrates in vivo. Genetic variants at the polymorphic NAT2 locus have been described. We expressed five of the most common NAT2 variants (NAT2 4, NAT2 5A, NAT2 5B, NAT2 6A and NAT2 7B) in Escherichia coli as a convenient source of the human variants. The apparent Km values (at 100 microM acetyl CoA as co-substrate) of the different NAT2 variants for sulphamethazine, dapsone, p-anisidine, 2-aminofluorene, procainamide and isoniazid were determined. Data show that the apparent Km of the slow variant NAT2 7B for the arylamine sulphamethazine was 10-fold lower than all the other allotypes. The apparent Km for the structurally related sulphone antibiotic dapsone was 5-fold lower for the slow variant NAT2 7B when compared with the wild-type NAT2 4. These results indicate that the NAT2 7B specific amino acid substitution, Gly286-Glu, is important in promoting the binding of sulphamethazine and dapsone to the active site.


Assuntos
Arilamina N-Acetiltransferase/metabolismo , Isoenzimas/metabolismo , Arilamina N-Acetiltransferase/genética , Sequência de Bases , Clonagem Molecular , DNA , Escherichia coli , Vetores Genéticos , Humanos , Isoenzimas/genética , Cinética , Dados de Sequência Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
13.
Biochem Pharmacol ; 44(6): 1099-104, 1992 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-1329759

RESUMO

N-Acetyltransferase activities associated with erythrocytes from 20 individuals have been determined with p-aminobenzoic acid as substrate. A three-fold variation in Vmax is found. The N-acetyltransferase genotype of the individuals has been determined and there is no correlation between the extent of acetylation measured in the individuals' erythrocytes and the inheritance of alleles at the polymorphic NAT locus. Folate is confirmed to be an inhibitor of arylamine N-acetyltransferase activity measured in erythrocytes. The content of folate in erythrocytes of individuals also varies. The individual with the maximum folate content has the minimum N-acetyltransferase activity. The monomorphic N-acetyltransferase gene from individuals spanning the range of N-acetyltransferase activity have been amplified, using the polymerase chain reaction. The pattern of restriction enzyme digestion of the monomorphic N-acetyltransferase gene with a series of eight restriction enzymes is the same for individuals spanning the activity range of arylamine N-acetyltransferase in their erythrocytes.


Assuntos
Arilamina N-Acetiltransferase/sangue , Eritrócitos/enzimologia , Ácido 4-Aminobenzoico/metabolismo , Arilamina N-Acetiltransferase/antagonistas & inibidores , Arilamina N-Acetiltransferase/genética , Sequência de Bases , Enzimas de Restrição do DNA , Ácido Fólico/farmacologia , Amplificação de Genes , Genótipo , Humanos , Cinética , Metotrexato/farmacologia , Dados de Sequência Molecular
14.
Biochem Pharmacol ; 62(12): 1661-73, 2001 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11755120

RESUMO

ABT-770 [(S)-N-[1-[[4'-trifluoromethoxy-[1,1'-biphenyl]-4-yl]oxy]methyl-2-(4,4-dimethyl-2,5-dioxo-1-imidazolidinyl)ethyl]-N-hydroxyformamide], a matrix metalloproteinase inhibitor (MMPI), produced generalized phospholipidosis in rats. Phospholipid accumulation was accompanied by retention of drug-related material and was associated with increased mortality. Generation of a successful drug candidate depended upon understanding the cause of the phospholipidosis and redesigning the chemical structure accordingly. ABT-770 and other MMPIs, plus several metabolites of each, were assayed for their ability to induce phospholipidosis in primary cultured rat and human hepatocytes. Phospholipid accumulation was detected by following the incorporation of a fluorescent phospholipid analogue into intracytoplasmic inclusion bodies characteristic of phospholipid storage disorders. At 24 and 48 hr, none of the parent compounds induced phospholipidosis in vitro in rat or human hepatocytes. Phospholipidosis was associated primarily with an amine metabolite of ABT-770. The amine metabolite of another MMPI, ABT-518 ([S-(R*,R*)]-N-[1-(2,2-dimethyl-1,3-dioxol-4-yl)-2-[[4-[4-(trifluoromethoxy)-phenoxy]phenyl]sulfonyl]ethyl]-N-hydroxyformamide), produced little phospholipidosis in rat and human hepatocytes even at concentrations up to 100 microM. The presence or absence of phospholipidosis in the in vitro assay correlated well with ultrastructural findings and drug accumulation in rat tissues. ABT-770, which produced phospholipidosis associated with its amine metabolite in vitro and in vivo, also generated a higher tissue to plasma distribution of metabolites particularly in tissues where phospholipidosis was observed. ABT-518 and its amine metabolite, however, produced low tissue to plasma ratios and induced little to no phospholipidosis in vitro or in vivo. These results demonstrate that the phospholipidosis observed for ABT-770 could be attributed to a cationic metabolite, and that altering the properties of such a metabolite, by modification of the parent compound, alleviated the disorder.


Assuntos
Compostos de Bifenilo/efeitos adversos , Hepatócitos/efeitos dos fármacos , Ácidos Hidroxâmicos/efeitos adversos , Lipidoses/induzido quimicamente , Inibidores de Metaloproteinases de Matriz , Animais , Compostos de Bifenilo/metabolismo , Formamidas/metabolismo , Formamidas/farmacologia , Inibidores da Protease de HIV/efeitos adversos , Inibidores da Protease de HIV/metabolismo , Hepatócitos/metabolismo , Humanos , Ácidos Hidroxâmicos/metabolismo , Masculino , Metaloproteinases da Matriz/metabolismo , Ratos , Ratos Sprague-Dawley
15.
Radiat Res ; 137(2): 238-50, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8134548

RESUMO

The biokinetics of polonium in nonhuman primates (Papio anubis) has been studied after intravenous injection of 210Po citrate. The urinary excretion of polonium in the baboon could be described by a single exponential function with a half-time of 15.6 days. Excretion fractions of polonium were found to be markedly different from those reported for other species, including humans. Polonium-210 was found to be distributed throughout the soft tissues of the baboon with 29% of the injected polonium being deposited in liver, 7% in kidneys and 0.6% in spleen. Retention of polonium in all tissues exhibited single exponential functions; however, the biological half-times were variable, ranging from 15 to 50 days.


Assuntos
Polônio/farmacocinética , Animais , Fezes/química , Feminino , Papio , Distribuição Tecidual
16.
Arch Surg ; 117(4): 401-4, 1982 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7065885

RESUMO

Hemorrhagic pancreatitis was induced in dogs by a retrograde infusion of the pancreatic duct with a mixture of taurocholate sodium and trypsin. Seven of the 13 dogs were pretreated with antibiotics. The hemorrhagic ascitic fluid (HAF) recovered from the dogs' abdomens was injected intraperitoneally into mice in volumes of 2.5, 5, 10, 15, and 20 mL. The mice were divided into two groups depending on whether the HAF received was from dogs given antibiotics. The mortality among the mice was proportional to the volume of HAF injected. The mortality among mice receiving the sterile HAF was 79.4% at 20 mL, 55.8% at 15 mL, 29.4% at 10 mL, 26% at 5 mL, and 17% at 2.5 mL. There were no deaths among mice receiving 25 mL and saline solution and the mortality was 15% among mice receiving 20 mL of dog plasma.


Assuntos
Líquido Ascítico , Pancreatite/metabolismo , Animais , Antibacterianos/administração & dosagem , Líquido Ascítico/análise , Líquido Ascítico/metabolismo , Cães , Hemorragia/metabolismo , Injeções Intraperitoneais , Camundongos , Modelos Biológicos , Mortalidade , Pancreatite/induzido quimicamente , Ácido Taurocólico , Tripsina
17.
J Biotechnol ; 79(3): 245-57, 2000 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-10867185

RESUMO

Isinglass is widely used commercially to clarify alcoholic beverages by aggregation of the yeast and other insoluble particles. It is derived from swim bladders of tropical fish by solubilisation in organic acids and consists predominantly of the protein collagen. The low content of intermolecular cross-links allows ready dissolution of swim bladder compared to bovine hide which is cross-linked by a high proportion of stable bonds and requires enzymic digestion to solubilise. Isinglass is no longer effective as a clarifying agent if thermally denatured hence the collagenous triple helical structure must be maintained. Thermal denaturation of isinglass occurs at 29 degrees C, compared to 40-41 degrees C for mammalian collagens, primarily due to the lower hydroxyproline content. The hydroxyproline is essential for the formation of H-bonded water-bridges through the hydroxyl group and the peptide chain thereby stabilising the triple helix. Based on the lower enthalpy determined by differential scanning calorimetry we have calculated that the thermally labile domain of the isinglass molecule was 41 residues compared to 66 for mammalian collagen. The fining efficiency was unaffected by pH, chelating agents, detergents and removal of surface proteins from yeast cells. Studies on the mechanism of action of isinglass have shown that higher molecular weight aggregates that increase the length of the collagen molecules (trimers, tetramers, etc.) increase efficiency and that their surface charge are important in the clarification process. By chemical modification, we have shown that blocking positively charged groups had no effect on the fining process, whilst negative charges are clearly essential and that increasing the negative charge by succinylation increases its efficacy. Solutions of bovine hide collagen were shown to be equally effective in refining beers and standard yeast preparations. The higher thermal denaturation temperature, ready availability and reproducibility of bovine collagen preparations gives it considerable advantages over isinglass.


Assuntos
Colágeno/química , Gelatina/química , Sacos Aéreos/química , Animais , Arginina/antagonistas & inibidores , Ácido Aspártico/metabolismo , Cálcio/farmacologia , Varredura Diferencial de Calorimetria , Bovinos , Quelantes/farmacologia , Colágeno/fisiologia , Descarboxilação , Detergentes/farmacologia , Peixes , Ácido Glutâmico/metabolismo , Concentração de Íons de Hidrogênio , Hidroxiprolina/metabolismo , Lisina/metabolismo , Peso Molecular , Monossacarídeos/farmacologia , Ácido N-Acetilneuramínico/farmacologia , Concentração Osmolar , Desnaturação Proteica , Saccharomyces cerevisiae/efeitos dos fármacos , Temperatura
18.
Am J Surg ; 144(1): 109-14, 1982 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7091519

RESUMO

The ERCP report in the patient's chart was compared with findings on common duct exploration or cystic duct cholangiography in 72 patients and found to have a sensitivity of 90.4 percent, a specificity of 98 percent, and an accuracy of 95.8 percent. Factors having the potential to influence the accuracy of ERCP were errors in interpretation by the surgeon and the radiologist and the operative technique of cholecystectomy. Also, the interval between the performance of the procedure and operation was particularly important in the patient with multiple small gallstones or small common duct stones. Small gallstones may spontaneously pass from the gallbladder to the common duct, or small common duct stones may spontaneously pass into the duodenum; therefore, the longer the interval between ERCP and operation, the greater the likelihood of a discrepancy. At operation, gallstones may be squeezed into the common duct during manipulation of the gallbladder unless the cystic duct is obstructed before manipulation of the gallbladder. We found ERCP sufficiently accurate to make cystic duct cholangiography unnecessary in most patients with cholelithiasis having a preoperative ERCP examination.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica/normas , Cálculos Biliares/diagnóstico , Idoso , Doenças dos Ductos Biliares/diagnóstico , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Reações Falso-Negativas , Reações Falso-Positivas , Humanos , Masculino , Pessoa de Meia-Idade , Pancreatopatias/diagnóstico , Estudos Retrospectivos
19.
JPEN J Parenter Enteral Nutr ; 4(3): 314-6, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7401270

RESUMO

The influence of preoperative serum albumin and percent ideal body weight on postoperative outcome was examined in 83 patients operated upon for colorectal cancer. Compared to patients with normal preoperative body weight and serum albumin, the following were noted: 1) those with low serum albumins had increased rates of complications (p < 0.02) and deaths (p < 0.02); 2) complications were increased in obese patients (p < 0.02); and 3) those with two nutritional abnormalities had increased rate of complications (p < 0.05) and deaths (p < 0.01). The group at highest risk, those with both low body weight and decreased serum albumin, had a complication rate of over 70% and a mortality rate of 42%.


Assuntos
Peso Corporal , Neoplasias Retais/mortalidade , Albumina Sérica/análise , Idoso , Neoplasias do Colo/complicações , Neoplasias do Colo/mortalidade , Neoplasias do Colo/cirurgia , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Neoplasias Retais/complicações , Neoplasias Retais/cirurgia , Risco
20.
Gerontologist ; 33(3): 415-8, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7686873

RESUMO

In the absence of an authoritative, current, and detailed source of information about videos for teaching gerontology and geriatrics, we developed a program to screen and evaluate videos. At our Video Journal Club, multidisciplinary health professionals view a video, complete a written evaluation, discuss its strengths and weaknesses, and provide a critique to be used as the basis of a narrative review. In the process, we offer an opportunity for continuing education and an avenue for exchange across disciplines.


Assuntos
Recursos Audiovisuais/normas , Educação Médica Continuada/métodos , Geriatria/educação , Gravação de Videoteipe/normas , Difusão de Inovações , Estudos de Avaliação como Assunto , Equipe de Assistência ao Paciente/organização & administração
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