RESUMO
Background: Expression of PD-L1 in tumor cells and tumor-infiltrating immune cells has been associated with improved efficacy to anti-PD-1/PD-L1 inhibitors in patients with advanced-stage non-small-cell lung cancer (NSCLC) and emerged as a potential biomarker for the selection of patients to cancer immunotherapies. We investigated the utility of circulating tumor cells (CTCs) and circulating white blood cells (WBCs) as a noninvasive method to evaluate PD-L1 status in advanced NSCLC patients. Patients and methods: CTCs and circulating WBCs were enriched from peripheral blood samples (ISET® platform; Rarecells) from 106 NSCLC patients. PD-L1 expression on ISET filters and matched-tumor tissue was evaluated by automated immunostaining (SP142 antibody; Ventana), and quantified in tumor cells and WBCs. Results: CTCs were detected in 80 (75%) patients, with levels ranging from 2 to 256 CTCs/4 ml, and median of 60 CTCs/4 ml. Among 71 evaluable samples with matched-tissue and CTCs, 6 patients (8%) showed ≥1 PD-L1-positive CTCs and 11 patients (15%) showed ≥1% PD-L1-positive tumor cells in tumor tissue with 93% concordance between tissue and CTCs (sensitivity = 55%; specificity = 100%). From 74 samples with matched-tissue and circulating WBCs, 40 patients (54%) showed ≥1% PD-L1-positive immune infiltrates in tumor tissue and 39 patients (53%) showed ≥1% PD-L1 positive in circulating WBCs, with 80% concordance between blood and tissue (sensitivity = 82%; specificity = 79%). We found a trend for worse survival in patients receiving first-line cisplatin-based chemotherapy treatments, whose tumors express PD-L1 in CTCs or immune cells (progression-free and overall survival), similar to the effects of PD-L1 expression in matched-patient tumors. Conclusions: These results demonstrated that PD-L1 status in CTCs and circulating WBCs correlate with PD-L1 status in tumor tissue, revealing the potential of CTCs assessment as a noninvasive real-time biopsy to evaluate PD-L1 expression in patients with advanced-stage NSCLC.
Assuntos
Antígeno B7-H1/sangue , Carcinoma Pulmonar de Células não Pequenas/sangue , Leucócitos/metabolismo , Neoplasias Pulmonares/sangue , Células Neoplásicas Circulantes/metabolismo , Antígeno B7-H1/biossíntese , Carcinoma Pulmonar de Células não Pequenas/patologia , Hemofiltração/métodos , Humanos , Neoplasias Pulmonares/patologia , Estadiamento de NeoplasiasRESUMO
BACKGROUND: Previous studies indicate that endothelial injury, as demonstrated by the presence of circulating endothelial cells (CECs), may predict clinical outcome in cancer patients. In addition, soluble CD146 (sCD146) may reflect activation of angiogenesis. However, no study has investigated their combined clinical value in patients undergoing resection for non-small cell lung cancer (NSCLC). METHODS: Data were collected from preoperative blood samples from 74 patients who underwent resection for NSCLC. Circulating endothelial cells were defined, using the CellSearch Assay, as CD146+CD105+CD45-DAPI+. In parallel, sCD146 was quantified using an ELISA immunoassay. These experiments were also performed on a group of 20 patients with small-cell lung cancer, 60 healthy individuals and 23 patients with chronic obstructive pulmonary disease. RESULTS: The CEC count and the plasma level of sCD146 were significantly higher in NSCLC patients than in the sub-groups of controls (P<0.001). Moreover, an increased CEC count was associated with higher levels of sCD146 (P=0.010). Both high CEC count and high sCD146 plasma level at baseline significantly correlated with shorter progression-free survival (P<0.001, respectively) and overall survival (P=0.005; P=0.009) of NSCLC patients. CONCLUSIONS: The present study provides supportive evidence to show that both a high CEC count and a high sCD146 level at baseline correlate with poor prognosis and may be useful for the prediction of clinical outcome in patients undergoing surgery for NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/sangue , Neoplasias Pulmonares/sangue , Adulto , Idoso , Biomarcadores Tumorais/sangue , Antígeno CD146/sangue , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/cirurgia , Intervalo Livre de Doença , Células Endoteliais/patologia , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/patologia , Adulto JovemRESUMO
PURPOSE: This study aimed to analyze, through a hierarchical model, the risk factors associated with the recurrence of chemo-induced oral mucositis (OM) in children and adolescents. METHODS: A retrospective cohort with 31 individuals of both sexes, aged 1-18 years, who were undergoing chemotherapy, and presented OM lesions was conducted. Data collection included analysis of medical records, interviews, and intraoral examination. Information regarding patients' socioeconomic and demographic profile, underlying disease, antineoplastic regimen, hematological condition, and oral health status were collected. To assess the association of independent variables with the outcome, the Chi-square, Fisher's Exact, and Mann-Whitney tests were used, in addition to a binary logistic regression model, with a maximum error of 5% and a 95% confidence interval. RESULTS: Significant associations were observed between the history of OM and the diagnosis of the child/adolescent, neutrophil count, previous cancer treatments and the chemotherapy scheme in use (p < 0.05). Binary logistic regression revealed a 13.69 higher risk of developing OM recurrence in individuals who received high-dose methotrexate (MTX) therapy. CONCLUSION: Socioeconomic and demographic factors did not influence OM recurrence. However, clinical variables, such as neutropenia, diagnosis of leukemia, and high-dose MTX protocols increase the chance of OM new cases.
Assuntos
Antineoplásicos , Metotrexato , Recidiva , Estomatite , Humanos , Feminino , Masculino , Criança , Estomatite/induzido quimicamente , Estudos Retrospectivos , Adolescente , Pré-Escolar , Lactente , Fatores de Risco , Antineoplásicos/efeitos adversos , Metotrexato/efeitos adversosRESUMO
BACKGROUND AND OBJECTIVE: Recurrence rates after surgery for non-small cell lung cancer (NSCLC) range from 25 to 50% and 5-year survival is only 60-70%. Because no biomarkers are predictive of recurrence or the onset of metastasis, pathological TNM (pTNM) staging is currently the best prognostic factor. Consequently, the preoperative detection of circulating tumour cells (CTCs) might be useful in tailoring therapy. The aim of this study was to characterize morphologically any circulating non-haematological cells (CNHCs) in patients undergoing surgery for NSCLC using the isolation by size of epithelial tumour cell (ISET) method. METHODS: Of 299 blood samples tested, 250 were from patients with resectable NSCLC and 59 from healthy controls. The presence of CNHCs was assessed blindly and independently by 10 cytopathologists on May-Grünwald-Giemsa stained filters and the cells classified into three groups: (i) malignant cells, (ii) uncertain malignant cells, and (iii) benign cells. We assessed interobserver agreement using Kappa (κ) analysis as the measure of agreement. RESULTS: A total of 123 out of 250 (49%) patients showed CNHCs corresponding to malignant, uncertain malignant and benign cells, in 102/250 (41%), 15/250 (6%) and 6/250 (2%) cases, respectively. No CNHCs were detected in the blood of healthy subjects. Interobserver diagnostic variability was absent for CNHCs, low for malignant cells and limited for uncertain malignant and benign cells. CONCLUSION: Identification of CTCs in resectable NSCLC patients, using ISET technology and according to cytopathological criteria of malignancy, appears to be a new and promising field of cytopathology with potential relevance to lung oncology.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Separação Celular/métodos , Citodiagnóstico/métodos , Células Epiteliais/patologia , Neoplasias Pulmonares/patologia , Células Neoplásicas Circulantes/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/sangue , Estudos de Casos e Controles , Tamanho Celular , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The precise regulation of growth factor signalling is crucial to the molecular control of development in Drosophila. Post-translational modification of signalling molecules is one of the mechanisms that modulate developmental signalling specificity. We describe a new gene, fringe connection (frc), that encodes a nucleotide-sugar transporter that transfers UDP-glucuronic acid, UDP-N-acetylglucosamine and possibly UDP-xylose from the cytoplasm into the lumen of the endoplasmic reticulum/Golgi. Embryos with the frc mutation display defects in Wingless, Hedgehog and fibroblast growth factor signalling. Clonal analysis shows that fringe-dependent Notch signalling is disrupted in frc mutant tissue.
Assuntos
Drosophila melanogaster/genética , Glicosiltransferases/metabolismo , Heparitina Sulfato/metabolismo , N-Acetilglucosaminiltransferases , Transdução de Sinais/fisiologia , Sequência de Aminoácidos , Animais , Citoplasma/metabolismo , Proteínas de Drosophila , Drosophila melanogaster/embriologia , Drosophila melanogaster/crescimento & desenvolvimento , Retículo Endoplasmático/metabolismo , Glicosiltransferases/genética , Complexo de Golgi/metabolismo , Humanos , Dados de Sequência Molecular , Morfogênese , Fenótipo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Uridina Difosfato Ácido Glucurônico/metabolismo , Uridina Difosfato N-Acetilglicosamina/metabolismo , Uridina Difosfato Xilose/metabolismo , Asas de Animais/embriologia , Asas de Animais/crescimento & desenvolvimentoRESUMO
Acute colitis is characterized by a large number of polymorphonuclear leukocytes (PMNLs) migrating across the columnar epithelium in response to inflammatory stimuli. Several of these inflammatory factors have been characterized as proapoptotic inducers for intestinal epithelial cells. Our aim was to elucidate the role of PMNL transmigration in the onset of intestinal epithelial cell apoptosis. We found that PMNL migration, in response to N-formyl-methionyl-leucyl-phenylalanine across monolayers of intestinal epithelial cells (T84), was associated with activation of caspase-2, -3, and -9 and poly(ADP-ribose) polymerase cleavage within epithelial cells. Moreover, dihydrocytochalasin B treatment of T84 cells induced apoptosis with similar characteristics. Although Fas and Fas ligand were expressed on T84 cells and PMNLs, treatment of epithelial cells with an antagonistic anti-Fas antibody failed to prevent apoptosis induced by migrating PMNLs. Owing to the F-actin reorganization accompanying PMNL transmigration, these findings indicate a direct relationship between PMNL migration and induction of apoptosis in epithelial cells. This apoptotic process appears to involve remodeling of the actin cytoskeleton of enterocytes independent of the Fas/Fas ligand pathway.
Assuntos
Apoptose/imunologia , Movimento Celular/imunologia , Células Epiteliais/citologia , Mucosa Intestinal/citologia , Neutrófilos/citologia , Actinas/metabolismo , Caspase 2 , Caspase 3 , Caspase 9 , Caspases/metabolismo , Colite/imunologia , Colite/fisiopatologia , Neoplasias do Colo , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Precursores Enzimáticos/metabolismo , Células Epiteliais/enzimologia , Proteína Ligante Fas , Citometria de Fluxo , Humanos , Mucosa Intestinal/imunologia , Glicoproteínas de Membrana/metabolismo , Microscopia Imunoeletrônica , Poli(ADP-Ribose) Polimerase-1 , Poli(ADP-Ribose) Polimerases , Polímeros/metabolismo , Proteínas/metabolismo , Células Tumorais Cultivadas , Receptor fas/metabolismoRESUMO
A homeologous mitotic recombination assay was used to test the role of Saccharomyces cerevisiae mismatch repair genes PMS1, MSH2 and MSH3 on recombination fidelity. A homeologous gene pair consisting of S. cerevisiae SPT15 and its S. pombe homolog were present as a direct repeat on chromosome V, with the exogenous S. pombe sequences inserted either upstream or downstream of the endogenous S. cerevisiae gene. Each gene carried a different inactivating mutation, rendering the starting strain Spt15-. Recombinants that regenerated SPT15 function were scored after nonselective growth of the cells. In strains wild type for mismatch repair, homeologous recombination was depressed 150- to 180-fold relative to homologous controls, indicating that recombination between diverged sequences is inhibited. In one orientation of the homeologous gene pair, msh2 or msh3 mutations resulted in 17- and 9.6-fold elevations in recombination and the msh2 msh3 double mutant exhibited an 43-fold increase, implying that each MSH gene can function independently in trans to prevent homeologous recombination. Homologous recombination was not significantly affected by the msh mutations. In the other orientation, only msh2 strains were elevated (12-fold) for homeologous recombination. A mutation in MSH3 did not affect the rate of recombination in this orientation. Surprisingly, a pms1 deletion mutant did not exhibit elevated homeologous recombination.
Assuntos
Reparo do DNA/genética , Recombinação Genética/genética , Saccharomyces cerevisiae/genética , Sequência de Bases , Cromossomos/genética , Cromossomos/metabolismo , Proteínas de Ligação a DNA/genética , Deleção de Genes , Mitose/genética , Dados de Sequência Molecular , Mutação , Homologia de Sequência do Ácido Nucleico , Proteína de Ligação a TATA-Box , Fatores de Transcrição/genéticaRESUMO
A variety of bacterial enterocolitis in their active stages are characterized by the migration of polymorphonuclear leukocytes (PMNs) across epithelial surfaces. These mechanisms could explain some effects of enterotoxins observed in the intestinal mucosae. Here, using specific inhibitors, we investigated the potential role of CD10 (E.C. 3.4.24.11), present at the surface of human neutrophils, on formyl-Met-Leu-Phe (fMLP)-induced PMN migration across cultured monolayers of the human intestinal cell line T84. Transmigration of human neutrophils across T84 epithelial cells was observed for concentrations of fMLP as low as 10(-9) M, whereas maximal effect was achieved at 10(-7) M as determined by transepithelial resistances and PMN myeloperoxidase assays. RB25, a CD10 inhibitor, reduced by two orders of magnitude the concentration of fMLP required to obtain full neutrophil transmigration across T84 epithelial cell line. RB25 response was concentration dependent with half-maximal and maximal effect occurring at 10(-9) and 10(-7) M, respectively. These concentrations of RB25 corresponded exactly to the half-maximal and maximal inhibition of endopeptidase 24.11 at the neutrophil cell surface. However, the effect of CD10 inhibitors on PMN transmigration cannot be accounted for by a direct action on T84 epithelial cells, since these cells fail to express any detectable endopeptidase 24.11 activity. Moreover, blocking of CD10 enzymatic activity by various and selective inhibitors potentiated the effect of low concentrations of fMLP on PMN transmigration. Finally, RB25 failed to affect interleukin-8 (IL-8)-induced PMN transmigration across T84 epithelial cells, in agreement with the preference of CD10 for small peptidic substrates. Taken together, these results demonstrate that inhibition of CD10 significantly reduced the concentration of fMLP needed for eliciting transmigration of PMN across intestinal epithelia.
Assuntos
Compostos de Benzilideno/farmacologia , Quimiotaxia de Leucócito/fisiologia , Glicina/análogos & derivados , Mucosa Intestinal/fisiologia , Neprilisina/antagonistas & inibidores , Neutrófilos/fisiologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Neoplasias do Colo , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Glicina/farmacologia , Humanos , Técnicas In Vitro , Neprilisina/sangue , Neutrófilos/efeitos dos fármacos , Peroxidase/sangue , Células Tumorais CultivadasRESUMO
A rapid and efficient Dispersive Liquid-Liquid Microextraction (DLLME) followed by Laser-Induced Breakdown Spectroscopy detection (LIBS) was evaluated for simultaneous determination of Cr, Cu, Mn, Ni and Zn in water samples. Metals in the samples were extracted with tetrachloromethane as pyrrolidinedithiocarbamate (APDC) complexes, using vortex agitation to achieve dispersion of the extractant solvent. Several DLLME experimental factors affecting extraction efficiency were optimized with a multivariate approach. Under optimum DLLME conditions, DLLME-LIBS method was found to be of about 4.0-5.5 times more sensitive than LIBS, achieving limits of detection of about 3.7-5.6 times lower. To assess accuracy of the proposed DLLME-LIBS procedure, a certified reference material of estuarine water was analyzed.
RESUMO
A novel method for discovery of HIV-1 protease inhibitors in complex biological samples has been developed. The assay is based on two specific reagents: a recombinant protein constituted by a portion of the HIV-1 Gag polyprotein comprising the p17-p24 cleavage site, fused to E. coli beta-galactosidase, and a monoclonal antibody which binds the fusion protein in the Gag region. Binding occurs only if the fusion protein has not been cleaved by the HIV-1 protease. The assay has been adapted for the screening of large numbers of samples in standard 96-well microtiter plates. Using this method about 12000 microbial fermentation broths have been tested and several HIV-1 protease inhibitory activities have been detected. One of these has been studied in detail.
Assuntos
Inibidores da Protease de HIV , Sequência de Aminoácidos , Anticorpos Monoclonais , Western Blotting , Produtos do Gene gag/metabolismo , Dados de Sequência Molecular , Inibidores de Proteases/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismoRESUMO
We evaluated the relationship of microalbuminuria to hyperinsulinemia and family history of hypertension in 92 never-treated essential hypertensives (mean 24-h blood pressure >140 or 90 mm Hg), with positive (F+) or negative (F-) family history of hypertension: 31 had microalbuminuria (MA+) (urinary albumin excretion [UAE], 30 to 300 mg/24 h) and 61 had normal (<30 mg/24 h) UAE (MA-). Glucose and insulin values before and 30, 60, 90, and 120 min after an oral glucose load were measured together with an index of peripheral insulin activity (10(4)/ insulin x glucose values at glucose peak). Subjects with and without microalbuminuria did not differ with regard to age, sex, body mass index, and 24-h heart rate, whereas 24-h, daytime, and nighttime systolic and diastolic blood pressure were significantly higher in MA+ than MA- patients. The prevalence of positive family history of hypertension was similar between MA+ and MA-, as were fasting and stimulated glucose and insulin values and the index of peripheral insulin activity. Subdividing the patients on the basis of family history of hypertension (59 F+, 33 F-) UAE was not significantly different between F+ and F-. UAE did not correlate with glucose and insulin parameters. From our results, in never-treated hypertensives, microalbuminuria is associated with higher blood pressure values, but is related neither to genetic predisposition to hypertension, nor to hyperinsulinemia; therefore, impaired insulin sensitivity and microalbuminuria are two components of the hypertensive syndrome, largely independent of each other.
Assuntos
Albuminúria/diagnóstico , Albuminúria/genética , Hiperinsulinismo/diagnóstico , Hiperinsulinismo/genética , Hipertensão Renal/diagnóstico , Hipertensão Renal/genética , Adulto , Albuminúria/epidemiologia , Glicemia , Pressão Sanguínea , Monitorização Ambulatorial da Pressão Arterial , Índice de Massa Corporal , Saúde da Família , Feminino , Teste de Tolerância a Glucose , Frequência Cardíaca , Humanos , Hiperinsulinismo/epidemiologia , Hipertensão Renal/epidemiologia , Insulina/sangue , Masculino , Pessoa de Meia-Idade , PrevalênciaRESUMO
Using 24-h ambulatory blood pressure (BP) monitoring and digitized M-mode echocardiography, we evaluated whether microalbuminuria is related to preclinical left ventricular (LV) diastolic dysfunction in hypertensive patients. We selected 87 never-treated hypertensive patients (mean 24-h BP > 140 and/or > 90 mm Hg); albuminuria was evaluated as mean value of 24-h urinary albumin excretion (UAE) from two 24-h urine collections. Microalbuminuria was found in 28 patients, classified as MA+ (UAE 30 to 300 mg/24 h); 59 patients had normal UAE (< 30 mg/24 h) and were classified as MA-. The MA+ and MA- groups did not differ with regard to age, sex, body mass index, or 24-h heart rate, whereas 24-h, daytime, and nighttime systolic and diastolic BP were significantly higher in MA+ than in MA-. The LV mass index was greater in MA+, as was the prevalence of LV hypertrophy; peak shortening rate of LV diameter, index of systolic function, was normal in all, but was lower in MA+. Peak lengthening rate of LV diameter and peak thinning rate of posterior wall, indices of diastolic function, were lower in MA+ and the prevalence of diastolic dysfunction was higher in MA+. UAE was inversely correlated with both indices of LV diastolic function, also after correction for age, 24-h heart rate, 24-h BP, and LV mass. In conclusion, in never-treated hypertensive patients, microalbuminuria is not only associated with greater myocardial mass, but is also related with preclinical impairment of LV diastolic function. This relation, independent from increased BP or LV mass, strengthens the role of microalbuminuria as an early and reliable marker of preclinical cardiac involvement.
Assuntos
Albuminúria/diagnóstico , Hipertensão/diagnóstico , Hipertrofia Ventricular Esquerda/diagnóstico , Adulto , Biomarcadores , Diástole , Feminino , Humanos , Hipertensão/urina , Hipertrofia Ventricular Esquerda/urina , Masculino , Pessoa de Meia-Idade , SístoleRESUMO
Our objective was to study the influence of HIV infection of polymorphonuclear leukocytes (PMN) on transepithelial migration. To date, reports of functional PMN chemotaxis in AIDS are contradictory. This is the first attempt to assess this function via an in vitro model allowing transmigration of neutrophils through an intestinal epithelial barrier. PMN were isolated from 45 HIV-infected patients and 45 healthy volunteers. PMN transmigration across T84 epithelial cells was initiated by applying either various concentrations of formyl-met-leu-phe peptide (f-MLP) or interleukin-8 and assayed by quantification of myeloperoxidase activity. CD11b, CD18, and CD47 expression on PMN was compared before and after transepithelial migration by flow cytometry analysis. CD11b expression was studied by electron microscopy. Apoptosis of transmigrated HIV PMN and control PMN was investigated by morphology and DNA fragmentation characterization. Compared to control PMN, HIV PMN exhibited a decrease in transepithelial migration that directly correlated with CD4+ counts. Basal and transepithelial migration-mediated expression of CD11b, CD18, and CD47 were unmodified in HIV PMN compared to control PMN. Electron microscopy labeling confirmed no difference in CD11b expression on HIV and control PMN. The index of apoptosis in transmigrated HIV PMN and control PMN was identical. These data provide evidence of a defect in the f-MLP-induced chemotaxis of PMN from HIV-infected patients across an intestinal epithelial barrier. This defective migration is not due to a quantitative modification of CD11b, CD18 and CD47 on HIV PMN suggesting a more subtle alteration. The impairment in the transmigration function may contribute in vivo to an increased susceptibility to intestinal bacterial infection in HIV-infected patients.
Assuntos
Infecções Bacterianas/imunologia , Quimiotaxia de Leucócito , Infecções por HIV/imunologia , Enteropatias/imunologia , Neutrófilos/imunologia , Adulto , Idoso , Apoptose , Infecções Bacterianas/complicações , Infecções Bacterianas/patologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Feminino , Citometria de Fluxo , Infecções por HIV/complicações , Infecções por HIV/patologia , Humanos , Interleucina-8/farmacologia , Enteropatias/complicações , Enteropatias/patologia , Antígeno de Macrófago 1/imunologia , Masculino , Microscopia Imunoeletrônica , Pessoa de Meia-Idade , N-Formilmetionina Leucil-Fenilalanina/farmacologiaRESUMO
The role of the polymorphonuclear leukocyte (PMN) cytoskeleton during the transmigration across colonic epithelial cells is not very well understood. In order to study the role of different components of the PMN cytoskeleton during transepithelial migration across a colonic epithelial cell monolayer (T84), PMN were preincubated with drugs affecting either the actin cytoskeleton (cytochalasin B, iota toxin of Clostridium perfringens, and phalloidin) or the microtubules (colchicine and taxol). The role of PMN myosin during transepithelial migration was investigated using the inhibitor 2,3-butanedione monoxime (BDM) and DC3B toxin. PMN intracellular Ca2+, during neutrophil adhesion and translocation across the epithelium, was assessed by the Ca2+ chelator 1, 2bis-(2-aminophenoxy)-ethane-N,N,N', N'-tetra-acetic acid tetrakis (acetoxymethyl) ester (BAPTA-AM). Transmigration of PMN was initiated by applying either interleukin-8 or formyl-met-leu-phe (fMLP). While colchicine and taxol preexposure did not influence PMN transepithelial migration, treatment with cytochalasin B, iota toxin, phalloidin, BDM, DC3B toxin and BAPTA-AM greatly diminished migration of PMN across T84 monolayers. Similarly, cell-cell contacts established between PMN and epithelial cells during the transmigration were diminished after treatment of PMN with iota toxin or cytochalasin B. These data show that the neutrophil actin cytokeleton and myosin, but not the microtubules, evoke a Ca2+ -dependent motility that facilitates migration across the colonic epithelial barrier.
Assuntos
ADP Ribose Transferases , Actinas/fisiologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Interleucina-8/farmacologia , Mucosa Intestinal/citologia , Microtúbulos/fisiologia , Miosinas/fisiologia , Neutrófilos/fisiologia , Toxinas Bacterianas/farmacologia , Cálcio/metabolismo , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Quelantes/farmacologia , Colchicina/farmacologia , Neoplasias do Colo/patologia , Citocalasina B/farmacologia , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/fisiologia , Citoesqueleto/ultraestrutura , Diacetil/análogos & derivados , Diacetil/farmacologia , Ácido Egtázico/análogos & derivados , Ácido Egtázico/farmacologia , Células Epiteliais/citologia , Humanos , Microtúbulos/efeitos dos fármacos , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/ultraestrutura , Paclitaxel/farmacologia , Faloidina/farmacologia , Células Tumorais CultivadasRESUMO
Actinoplanes sp. ATCC 33076 is a new strain that was found to produce an antibiotic, designated A-16686, which is a complex of three closely-related polypeptides containing chlorinated phenyl moieties and D-mannose. Both the complex and the single fractions possess a good activity against Gram-positive bacteria. A-16686 specifically inhibits the synthesis of the bacterial cell wall.
Assuntos
Actinomycetales/crescimento & desenvolvimento , Antibacterianos/isolamento & purificação , Depsipeptídeos , Bactérias Gram-Positivas/efeitos dos fármacos , Peptídeos Cíclicos , Actinomycetales/classificação , Aminoácidos/análise , Fenômenos Químicos , Química , Meios de Cultura , Avaliação Pré-Clínica de Medicamentos , Fermentação , Glicopeptídeos/isolamento & purificação , Glicopeptídeos/toxicidade , Testes de Sensibilidade MicrobianaRESUMO
GE37468 A is a novel antibiotic produced by Streptomyces sp. ATCC 55365. It has molecular mass 1309.48 and formula C59H52O12N14S5 and belongs to the thiazolyl peptide group of antibiotics. The structure was elucidated by 1H and 13C NMR and MS studies on intact molecule and its hydrolysis products. The antibiotic is a highly modified peptide containing a macrocycle and a side chain composed of a thiazole ring and two dehydroalanine units.
Assuntos
Antibacterianos/química , Peptídeos Cíclicos/química , Inibidores da Síntese de Proteínas/química , Streptomyces/metabolismo , Tiazóis/química , Precipitação Química , Bactérias Gram-Positivas/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Fator Tu de Elongação de Peptídeos/antagonistas & inibidores , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrofotometria UltravioletaRESUMO
SB22484, active against Neisseriae gonorrhoeae and Neisseriae meningitidis, is a complex of four factors, designed 1 through 4, which from two pairs of isomers, 1 and 3, and 2 and 4. Factors 1 and 3 account for 65% of the complex, factor 3 being the predominant one. On the basis of the existing and implemented correlations between structure and physico-chemical characteristics (UV and IR spectroscopies, ionization properties, MS as FAB and as negative and positive CI, 1H NMR spectroscopy as 2D COSY and NOESY) in the aurodox field, the complete structures were assigned. Factor 3 can be described as N-[7-[5(R)-[7-[1,2-dihydro-4-hydroxy-1H-2-oxo-3-pyridinyl]-6-methyl- 7-oxo-1(E),3(E),5(E)-heptatrienyl]tetrahydro-3(S),4(R)-dihydrox yfuran-2 (S)-yl]-6(S)-methoxy-5,7(R)-dimethyl-2(E),4(E)-heptadienyl]-alpha (S)-methyl-5(S)-methyltetrahydro-2(S),4(S or R)-dihydroxy-6(S)-[1(E), 3(Z)-pentadienyl]-2H-pyran-2-acetamide. Factor 1 is an epimer of factor 3 with the opposite configuration at the anomeric center. Factors 2 and 4 have an ethyl group instead of the methyl group alpha to the acetamide moiety and are in the same stereochemical relationship as the pair 1 and 3.
Assuntos
Aurodox/análogos & derivados , Equilíbrio Ácido-Base , Aurodox/química , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Conformação Molecular , Estrutura Molecular , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , EstereoisomerismoRESUMO
New N-acyl derivatives of 1-N-desmethyl goldinamine were obtained from degradation of kirromycin. Periodate-oxidation of these derivatives provided new aldehydic fragments that were further elaborated. Both N-phenyl ureido and N-phthalimido derivatives of 1-N-desmethyl goldinamine are able to inhibit bacterial protein synthesis in cell-free assay and are active against whole microorganisms, although with lower potency than kirromycin. The derivatives from the aldehydic fragments are totally inactive.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Proteínas de Bactérias/biossíntese , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oxirredução , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Ftalimidas/síntese química , Ftalimidas/química , Ftalimidas/farmacologia , Piridonas/síntese química , Piridonas/química , Piridonas/farmacologia , Relação Estrutura-AtividadeRESUMO
The development of a screen targeted to antibiotics which bind elongation factor Tu (EF-Tu) is described. The method was based on selection of antimicrobial activities which were antagonized by exogenous EF-Tu. Kirromycin, a known inhibitor of EF-Tu, was positive in this screen. Among 47,000 microorganisms screened, several producers of kirromycin-type antibiotics were detected and the novel antibiotics GE2270 and GE37468 were discovered. These thiopeptide molecules constitute, along with amithiamycin, a novel class of antibiotics acting on EF-Tu.
Assuntos
Antibacterianos/análise , Fator Tu de Elongação de Peptídeos/metabolismo , Actinomycetales/metabolismo , Antibacterianos/antagonistas & inibidores , Antibacterianos/metabolismo , Fator Tu de Elongação de Peptídeos/farmacologia , Piridonas/análiseRESUMO
Antibiotic SB22484 is a novel member of the aurodox type antibiotic group produced in submerged-fermentation cultures of Streptomyces sp. NRRL 15496. The antibiotic complex is composed of two pairs of isomers with MW's of 752 and 766. The individual isomers, which were separated by preparative HPLC, equilibrate to a mixture of the isomer pair when left in aqueous solution. In vitro, SB22484 antibiotics strongly inhibited neisseriae and were also active against Streptococci, Ureaplasma urealyticum and Haemophilus influenzae.