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1.
Artigo em Inglês | MEDLINE | ID: mdl-38456522

RESUMO

OBJECTIVES: Well-established clinical practice for assessing progress in labor involves routine abdominal palpation and vaginal examination (VE). However, VE is subjective, poorly reproducible and painful for most women. In this study, our aim was to evaluate the feasibility of systematically integrating transabdominal and transperineal ultrasound assessment of fetal position, parasagittal angle of progression (psAOP), head-perineum distance (HPD) and sonographic cervical dilatation (SCD) to monitor the progress of labor in women undergoing induction of labor (IOL). We also aimed to determine if ultrasound can reduce women's pain during such examinations. METHODS: Women were recruited as they presented for IOL in three maternity units. Ultrasound assessments were performed in 100 women between 37 + 0 and 41 + 6 weeks' gestation. A baseline combined transabdominal and transperineal scan was performed, including assessment of fetal biometry, umbilical artery and fetal middle cerebral artery Doppler, amniotic fluid index, fetal spine and occiput positions, psAOP, HPD, SCD and cervical length. Intrapartum scans were performed instead of VE, unless there was a clinical indication to perform a VE, according to protocol. Participants were asked to indicate their level of pain by verbally giving a pain score between 0 and 10 (with 0 representing no pain) during assessment. Repeated measures data were analyzed using mixed-effect models to identify significant factors that affected the relationship between psAOP, HPD, SCD and mode of delivery. RESULTS: A total of 100 women were included in the study. Of these, 20% delivered by Cesarean section, 65% vaginally and 15% by instrumental delivery. There were no adverse fetal or maternal outcomes. A total of 223 intrapartum ultrasound scans were performed in 87 participants (13 women delivered before intrapartum ultrasound was performed), with a median of two scans per participant (interquartile range (IQR), 1-3). Of these, 76 women underwent a total of 151 VEs with a median of one VE per participant (IQR, 0-2), with no significant difference between vaginal- or Cesarean-delivery groups. After excluding those with epidural anesthesia during examination, the median pain score for intrapartum scans was 0 (IQR, 0-1) and for VE it was 3 (IQR, 0-6). Cesarean delivery was significantly associated with a slower rate of change in psAOP, HPD and SCD. CONCLUSIONS: Comprehensive transabdominal and transperineal ultrasound assessment can be used to assess progress in labor and can reduce the level of pain experienced during examination. Ultrasound assessment may be able to replace some transabdominal and vaginal examinations during labor. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

2.
Ultrasound Obstet Gynecol ; 60(2): 192-199, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35445767

RESUMO

OBJECTIVES: To determine whether first-trimester biomarkers of placental function can be used to screen for spontaneous preterm birth (sPTB), and to develop prediction models using maternal factors, obstetric history and biomarkers of placental function at 11-13 weeks for the calculation of patient-specific risk for sPTB. METHODS: This was a retrospective secondary analysis of data derived from a prospective cohort study on first-trimester screening for pre-eclampsia in singleton pregnancies attending for routine Down syndrome screening at 11 + 0 to 13 + 6 weeks' gestation at a tertiary obstetric unit between December 2016 and September 2019. A split-sample internal validation method was used to explore and develop prediction models for all sPTB at < 37 weeks and for PTB at < 37 weeks after preterm prelabor rupture of membranes (PPROM) using maternal risk factors, uterine artery Doppler indices, serum placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A) and ß-human chorionic gonadotropin (ß-hCG). Screening performance was assessed using receiver-operating-characteristics (ROC)-curve analysis, with calculation of the areas under the ROC curves (AUCs). RESULTS: A total of 9298 singleton pregnancies were included in this study. sPTB at < 37 weeks occurred in 362 (3.89%) cases, including 231 (2.48%) cases of PPROM. sPTB at < 34 weeks occurred in 87 (0.94%) cases, including 39 (0.42%) cases of PPROM. Identified maternal risk factors for sPTB at < 37 weeks included chronic hypertension, conception using in-vitro fertilization and history of PTB. Maternal risk factors for PPROM at < 37 weeks included conception using in-vitro fertilization and history of PTB. Median PlGF multiples of the median (MoM) and PAPP-A MoM were significantly reduced in women with sPTB at < 37 weeks, as well as in those who had PPROM, compared to those who delivered at term. Screening by a combination of maternal risk factors, PAPP-A and PlGF achieved better performance in predicting sPTB at < 37 weeks (AUC, 0.630 vs 0.555; detection rate (DR), 24.8% vs 16.6% at a false-positive rate (FPR) of 10%; P ≤ 0.0001) and PPROM at < 37 weeks (AUC, 0.643 vs 0.558; DR, 28.1% vs 17.0% at a FPR of 10%; P ≤ 0.0001) than using maternal risk factors alone. Both models were successfully applied to the internal validation dataset, with AUCs of 0.628 and 0.650, respectively. CONCLUSIONS: We demonstrated that low levels of maternal serum PAPP-A and PlGF in the first trimester are associated with increased risks of sPTB and PPROM at < 37 weeks. However, further research is needed to identify additional biomarkers to improve the screening performance of the combined model that includes maternal risk factors, PAPP-A and PlGF before clinical application. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.


Assuntos
Pré-Eclâmpsia , Nascimento Prematuro , Biomarcadores , Feminino , Ruptura Prematura de Membranas Fetais , Humanos , Recém-Nascido , Placenta/metabolismo , Fator de Crescimento Placentário , Pré-Eclâmpsia/diagnóstico , Gravidez , Primeiro Trimestre da Gravidez , Proteína Plasmática A Associada à Gravidez/metabolismo , Nascimento Prematuro/diagnóstico , Estudos Prospectivos , Estudos Retrospectivos , Artéria Uterina/diagnóstico por imagem
3.
Nat Genet ; 21(1): 111-4, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9916802

RESUMO

Expression of the human telomerase catalytic component, hTERT, in normal human somatic cells can reconstitute telomerase activity and extend their replicative lifespan. We report here that at twice the normal number of population doublings, telomerase-expressing human skin fibroblasts (BJ-hTERT) and retinal pigment epithelial cells (RPE-hTERT) retain normal growth control in response to serum deprivation, high cell density, G1 or G2 phase blockers and spindle inhibitors. In addition, we observed no cell growth in soft agar and detected no tumour formation in vivo. Thus, we find that telomerase expression in normal cells does not appear to induce changes associated with a malignant phenotype.


Assuntos
Transformação Celular Neoplásica , Biossíntese de Proteínas , RNA , Telomerase/biossíntese , Ácido Aspártico/análogos & derivados , Ácido Aspártico/farmacologia , Linhagem Celular , Linhagem Celular Transformada , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Proteínas de Ligação a DNA , Inibidores Enzimáticos/farmacologia , Humanos , Hidroxiureia/farmacologia , Inibidores da Síntese de Ácido Nucleico/farmacologia , Fenótipo , Ácido Fosfonoacéticos/análogos & derivados , Ácido Fosfonoacéticos/farmacologia , Fosforilação , Proteínas/genética , Proteína do Retinoblastoma/metabolismo , Telomerase/genética , Células Tumorais Cultivadas
4.
Pregnancy Hypertens ; 32: 28-34, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37003112

RESUMO

OBJECTIVES: To evaluate the diagnostic performance and clinical utility of the urine Congo red dot test (CRDT) in predicting preeclampsia (PE) within 7 days, 14 days and 28 days of assessment. STUDY DESIGN: A prospective single center double blind non-intervention study conducted from January 2020 to March 2022. Urine congophilia has been proposed as a point-of-care test for the prediction and rapid identification of PE. In our study, urine CRDT and pregnancy outcomes were assessed in women presenting with clinical features of suspected PE after 20 weeks of gestation. RESULTS: Among the 216 women analyzed, 78 (36.1 %) women developed PE, in which only 7 (9.0 %) of them had a positive urine CRDT test. The median (IQR) interval between the initial test and the diagnosis of PE was significantly shorter for women with a positive urine CRDT compared with women with a negative urine CRDT (1 day (0-5 days) vs 8 days (1-19 days), P = 0.027). The negative predictive value of a negative urine CRDT test for PE within 7 days, 14 days and 28 days of assessment were 83.73 % (95 %CI 81.75 %- 85.54 %), 78.92 % (95 % confidence interval [CI] 77.07 %- 80.71 %) and 71.77 % (95 %CI 70.06 %- 73.42 %) respectively. The sensitivity of the urine CRDT in ruling in PE within 7 days, 14 days and 28 days of assessment were 17.07 % (95 %CI 7.15 %- 32.06 %), 13.73 % (95 %CI 5.70 %- 26.26 %) and 10.61 % (95 %CI 4.37 %- 20.64 %), respectively. CONCLUSIONS: Urine CRDT alone has high specificity yet low sensitivity in the short-term prediction of PE in women with suspected PE. Further studies are required to evaluate its clinical utility.


Assuntos
Pré-Eclâmpsia , Gravidez , Feminino , Humanos , Masculino , Pré-Eclâmpsia/diagnóstico , Pré-Eclâmpsia/urina , Estudos Prospectivos , Resultado da Gravidez , Sensibilidade e Especificidade , Valor Preditivo dos Testes , Vermelho Congo , Biomarcadores
5.
Psychol Med ; 41(8): 1709-19, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20809999

RESUMO

BACKGROUND: We investigated cerebral structural connectivity and its relationship to symptoms in never-medicated individuals with first-onset schizophrenia using diffusion tensor imaging (DTI). METHOD: We recruited subjects with first episode DSM-IV schizophrenia who had never been exposed to antipsychotic medication (n=34) and age-matched healthy volunteers (n=32). All subjects received DTI and structural magnetic resonance imaging scans. Patients' symptoms were assessed on the Positive and Negative Syndrome Scale. Voxel-based analysis was performed to investigate brain regions where fractional anisotropy (FA) values significantly correlated with symptom scores. RESULTS: In patients with first-episode schizophrenia, positive symptoms correlated positively with FA scores in white matter associated with the right frontal lobe, left anterior cingulate gyrus, left superior temporal gyrus, right middle temporal gyrus, right middle cingulate gyrus, and left cuneus. Importantly, FA in each of these regions was lower in patients than controls, but patients with more positive symptoms had FA values closer to controls. We found no significant correlations between FA and negative symptoms. CONCLUSIONS: The newly-diagnosed, neuroleptic-naive patients had lower FA scores in the brain compared with controls. There was positive correlation between FA scores and positive symptoms scores in frontotemporal tracts, including left fronto-occipital fasciculus and left inferior longitudinal fasciculus. This implies that white matter dysintegrity is already present in the pre-treatment phase and that FA is likely to decrease after clinical treatment or symptom remission.


Assuntos
Encéfalo/ultraestrutura , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Adulto , Estudos de Casos e Controles , Imagem de Tensor de Difusão , Feminino , Lobo Frontal/ultraestrutura , Giro do Cíngulo/ultraestrutura , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Lobo Temporal/ultraestrutura
6.
Nanotechnology ; 22(7): 075101, 2011 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-21233545

RESUMO

Magnetite nanoparticles (MNPs) modified with sodium and calcium salts of poly(γ-glutamic acid) (NaPGA and CaPGA) were synthesized by the coprecipitation method, followed by characterization and evaluation of their antibacterial and cytotoxic effects. Superparamagnetic MNPs are particularly attractive for magnetic driving as well as bacterial biofilm and cell targeting in in vivo applications. Characterization of synthesized MNPs by the Fourier transform infrared spectra and magnetization curves confirmed the PGA coating on MNPs. The mean diameter of NaPGA- and CaPGA-coated MNPs as determined by transmission electron microscopy was 11.8 and 14 nm, respectively, while the x-ray diffraction pattern revealed the as-synthesized MNPs to be pure magnetite. Based on agar dilution assay, both NaPGA- and CaPGA-coated MNPs showed a lower minimum inhibitory concentration in Salmonella enteritidis SE 01 than the commercial antibiotics linezolid and cefaclor, but the former was effective against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 10832, whereas the latter was effective against Escherichia coli O157:H7 TWC 01. An in vitro cytotoxicity study in human skin fibroblast cells as measured by MTT assay implied the as-synthesized MNPs to be nontoxic. This outcome demonstrated that both γ-PGA-modified MNPs are cytocompatible and possess antibacterial activity in vitro, and thereby should be useful in in vivo studies for biomedical applications.


Assuntos
Antibacterianos/farmacologia , Nanopartículas de Magnetita/química , Ácido Poliglutâmico/análogos & derivados , Brometos/química , Cálcio/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Humanos , Magnetismo , Nanopartículas de Magnetita/ultraestrutura , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Ácido Poliglutâmico/síntese química , Ácido Poliglutâmico/farmacologia , Compostos de Potássio/química , Salmonella/efeitos dos fármacos , Sódio/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Termogravimetria , Difração de Raios X
8.
Science ; 269(5228): 1236-41, 1995 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-7544491

RESUMO

Eukaryotic chromosomes are capped with repetitive telomere sequences that protect the ends from damage and rearrangements. Telomere repeats are synthesized by telomerase, a ribonucleic acid (RNA)-protein complex. Here, the cloning of the RNA component of human telomerase, termed hTR, is described. The template region of hTR encompasses 11 nucleotides (5'-CUAACCCUAAC) complementary to the human telomere sequence (TTAGGG)n. Germline tissues and tumor cell lines expressed more hTR than normal somatic cells and tissues, which have no detectable telomerase activity. Human cell lines that expressed hTR mutated in the template region generated the predicted mutant telomerase activity. HeLa cells transfected with an antisense hTR lost telomeric DNA and began to die after 23 to 26 doublings. Thus, human telomerase is a critical enzyme for the long-term proliferation of immortal tumor cells.


Assuntos
Divisão Celular , DNA Nucleotidilexotransferase/metabolismo , RNA/metabolismo , Animais , Sequência de Bases , Morte Celular , Linhagem Celular , Clonagem Molecular , DNA Nucleotidilexotransferase/antagonistas & inibidores , DNA Nucleotidilexotransferase/química , DNA Nucleotidilexotransferase/genética , Células HeLa , Humanos , Dados de Sequência Molecular , Oligonucleotídeos Antissenso/farmacologia , Reação em Cadeia da Polimerase , RNA/química , RNA/genética , Moldes Genéticos , Transfecção , Células Tumorais Cultivadas
9.
Science ; 279(5349): 349-52, 1998 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-9454332

RESUMO

Normal human cells undergo a finite number of cell divisions and ultimately enter a nondividing state called replicative senescence. It has been proposed that telomere shortening is the molecular clock that triggers senescence. To test this hypothesis, two telomerase-negative normal human cell types, retinal pigment epithelial cells and foreskin fibroblasts, were transfected with vectors encoding the human telomerase catalytic subunit. In contrast to telomerase-negative control clones, which exhibited telomere shortening and senescence, telomerase-expressing clones had elongated telomeres, divided vigorously, and showed reduced straining for beta-galactosidase, a biomarker for senescence. Notably, the telomerase-expressing clones have a normal karyotype and have already exceeded their normal life-span by at least 20 doublings, thus establishing a causal relationship between telomere shortening and in vitro cellular senescence. The ability to maintain normal human cells in a phenotypically youthful state could have important applications in research and medicine.


Assuntos
Divisão Celular , Senescência Celular , Proteínas/metabolismo , RNA , Telomerase/metabolismo , Telômero/fisiologia , Biomarcadores , Catálise , Linhagem Celular , Transformação Celular Neoplásica , Clonagem Molecular , Proteínas de Ligação a DNA , Fibroblastos/citologia , Homeostase , Humanos , Cariotipagem , Fenótipo , Epitélio Pigmentado Ocular/citologia , Proteínas/genética , DNA Polimerase Dirigida por RNA/genética , DNA Polimerase Dirigida por RNA/metabolismo , Células-Tronco/citologia , Células-Tronco/enzimologia , Telomerase/genética , Telômero/metabolismo , Telômero/ultraestrutura , Transfecção , Células Tumorais Cultivadas , beta-Galactosidase/metabolismo
10.
Science ; 230(4727): 758-66, 1985 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-2414846

RESUMO

Heterokaryons provide a model system in which to examine how tissue-specific phenotypes arise and are maintained. When muscle cells are fused with nonmuscle cells, muscle gene expression is activated in the nonmuscle cell type. Gene expression was studied either at a single cell level with monoclonal antibodies or in mass cultures at a biochemical and molecular level. In all of the nonmuscle cell types tested, including representatives of different embryonic lineages, phenotypes, and developmental stages, muscle gene expression was induced. Differences among cell types in the kinetics, frequency, and gene dosage requirements for gene expression provide clues to the underlying regulatory mechanisms. These results show that the expression of genes in the nuclei of differentiated cells is remarkably plastic and susceptible to modulation by the cytoplasm. The isolation of the genes encoding the tissue-specific trans-acting regulators responsible for muscle gene activation should now be possible.


Assuntos
Diferenciação Celular , Idoso , Animais , Anticorpos Monoclonais , Fusão Celular , Núcleo Celular/ultraestrutura , Células Epidérmicas , Feto/metabolismo , Fibroblastos/citologia , Regulação da Expressão Gênica , Genes , Células HeLa/metabolismo , Humanos , Células Híbridas/metabolismo , Queratinas/fisiologia , Cinética , Fígado/citologia , Camundongos , Desenvolvimento Muscular , Músculos/citologia , Miosinas/genética , Fenótipo , Transcrição Gênica , Ativação Transcricional
11.
Bioresour Technol ; 99(5): 1026-35, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17462883

RESUMO

Poly(gamma-glutamic acid) (gamma-PGA), an extracellular polymeric substance (EPS) synthesized by Bacillus species, was explored to study its interaction with the basic brown 1 dye by conducting a systematic batch adsorption study as affected by two critical parameters, temperature and pH. Adsorption isotherms were closely predicted by Temkin equation among the eight isotherm models tested. The rate of adsorption was very rapid attaining equilibrium within 60 min and the kinetics were well described by both modified second-order and pseudo second-order models. Boyd's ion exchange model, which assumes exchanges of ions to be a chemical phenomenon, also fitted the kinetic data precisely. The adsorption rate increased with increasing solution temperature, however, a reversed trend was observed for the adsorption capacity. Changes in enthalpy, entropy and free energy values revealed dye adsorption by gamma-PGA to be an exothermic and spontaneous process involving no structural modification in gamma-PGA, whereas the activation energy of 37.21 kJ/mol indicated dye adsorption to be reaction-controlled. Following a rise in solution pH, the dye adsorption increased and reached a plateau at pH 5, while the maximum release of dye from spent gamma-PGA occurred at pH 1.5, suggesting a possible ion exchange mechanism. Ion exchange adsorption of basic dyes by gamma-PGA was further proved by the presence of two new IR bands at approximately 1600 and 1405.72 cm(-1), representing asymmetric and symmetric stretching vibration of carboxylate anion, for dye-treated gamma-PGA.


Assuntos
Compostos Azo/química , Biopolímeros/química , Corantes/química , Ácido Poliglutâmico/análogos & derivados , Adsorção , Bacillus subtilis/metabolismo , Biopolímeros/metabolismo , Concentração de Íons de Hidrogênio , Cinética , Ácido Poliglutâmico/química , Ácido Poliglutâmico/metabolismo , Temperatura , Termodinâmica
12.
Mol Cell Biol ; 10(9): 4953-6, 1990 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2117704

RESUMO

We have investigated the role that hemopoietic regulatory molecules may play in mouse embryogenesis prior to the appearance of hemopoietic stem cells or their microenvironments. Using polymerase chain reaction analysis, we detected mRNA transcripts for interleukin-6 (IL-6) and leukemia inhibitory factor (LIF) but not for granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-3 in mouse blastocysts at 3.5 days of gestation. Functional IL-6 protein was also detected in cultured blastocysts as a secreted product, as was an activity consistent with the presence of LIF protein. The expression of IL-6 and LIF in blastocysts prior to hemopoiesis suggests that these proteins may regulate the growth and development of trophoblasts or embryonic stem cells.


Assuntos
Blastocisto/fisiologia , Regulação da Expressão Gênica , Inibidores do Crescimento/genética , Hematopoese , Interleucina-6/genética , Linfocinas , Animais , Blastocisto/imunologia , Fatores Estimuladores de Colônias/genética , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Substâncias de Crescimento/genética , Interleucina-3/genética , Fator Inibidor de Leucemia , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Cultura de Órgãos , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Transcrição Gênica
13.
J Agric Food Chem ; 55(13): 5123-30, 2007 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-17542604

RESUMO

Tomato pulp waste, a byproduct obtained during the processing of tomato juice, has been shown to be a rich source of lycopene. The objectives of this study were to use gelatin and poly(gamma-glutamic acid) (gamma-PGA) as coating materials for the encapsulation of lycopene extract from tomato pulp waste. Initially, lycopene was extracted with supercritical carbon dioxide, followed by microencapsulation using an emulsion system consisting of 4.5% gelatin, 10% gamma-PGA, and 4.8% lycopene extract. Analysis of differential scanning calorimetry revealed that the thermal stability of the coating material could be up to 120 degrees C, with a mean particle size of 38.7 microm based on Coulter counter analysis. The total weight of microencapsulated powder was 617 microg with the yield of lycopene being 76.5%, indicating a 23.5% loss during freeze drying. During storage of microencapsulated powder, the concentrations of cis-, trans-, and total lycopene decreased along with increasing time and temperature. A fast release of lycopene in the powder occurred at pH 5.5 and 7.0, while no lycopene was released at pH 2.0 and 3.5.


Assuntos
Carotenoides/administração & dosagem , Carotenoides/isolamento & purificação , Manipulação de Alimentos , Frutas/química , Resíduos Industriais , Solanum lycopersicum/química , Cápsulas , Estabilidade de Medicamentos , Licopeno , Ácido Poliglutâmico/análogos & derivados , Pós
15.
Circ Res ; 89(9): 793-8, 2001 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-11679409

RESUMO

Advanced age is associated with endothelial dysfunction and increased risk for atherosclerosis. However, the mechanisms for these observed effects are not clear. To clarify the association between aging and loss of endothelial function, young human aortic endothelial cells (HAECs), senescent HAECs transfected with control vector, and immortalized HAECs containing human telomerase reverse transcriptase (hTERT) were compared for expression of endothelial nitric oxide synthase (eNOS) and production of NO. To investigate a specific function modulated by endothelial NO, adhesion of monocytes under basal conditions as well as after exposure to TNF-alpha was assessed. A decrease in eNOS mRNA, protein, and activity was observed in endothelial cells at senescence as compared with young HAEC; this effect was blunted in hTERT cells. In all cells, shear stress induced a greater increase in the expression of eNOS protein with the final result being higher levels in hTERT compared with senescent cells. Basal monocyte binding was significantly elevated on aged endothelial cells compared with parental and hTERT cells. Exposure of TNF-alpha resulted in a 2-fold increase in monocyte adhesion in senescent cells, whereas this effect was reduced in cells transfected with hTERT. Prior exposure to fluid flow significantly reduced subsequent monocyte adhesion in all groups. These studies demonstrate that replicative aging results in decreased endothelial expression of eNOS accompanied by enhanced monocyte binding. Stable expression of hTERT results in endothelial cells with a younger phenotype with greater amount of eNOS and NO activity. Thus, telomerase transfection may have important functional consequences on endothelial cells.


Assuntos
Envelhecimento/metabolismo , Senescência Celular/fisiologia , Endotélio Vascular/metabolismo , Óxido Nítrico Sintase/metabolismo , Telomerase/biossíntese , Aorta , Western Blotting , Adesão Celular/efeitos dos fármacos , Células Cultivadas , Proteínas de Ligação a DNA , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Humanos , Monócitos/citologia , Monócitos/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase/genética , Óxido Nítrico Sintase Tipo III , RNA Mensageiro/metabolismo , Estresse Mecânico , Telomerase/genética , Telomerase/farmacologia , Transfecção , Fator de Necrose Tumoral alfa/farmacologia
16.
J Agric Food Chem ; 54(17): 6452-9, 2006 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-16910744

RESUMO

Poly(gamma-glutamic acid) (gamma-PGA), a nontoxic and biodegradable macropolymer, was evaluated for its efficiency in binding three mutagenic heterocyclic amines (HAs), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-p-2), as affected by pH in a batch mode. The maximum HA sorption was attained for pH 3-7 and decreased sharply for pH less than 3. Binding isotherms obtained at pH 2.5 and 5.5 showed different isotherm shapes that belong to S and L types, respectively. The isotherm data at pH 2.5 were well described by a linear form of the Langmuir equation, while at pH 5.5 it showed two distinct curves, which were precisely fitted as multiple Langmuir curves. The deviation of linearity in Scatchard plot proved the multisite HA sorption. The Brunauer-Emmett-Teller equation also fitted better to isotherm data at pH 5.5, suggesting a multisite sorption caused by multimolecular HA layers on gamma-PGA. High HA sorption levels of 1250, 667, and 1429 mg/g at pH 2.5 and 1429, 909, and 1667 mg/g at pH 5.5 were observed for MeIQ, 4,8-DiMeIQx, and Trp-p-2, respectively. Among the HAs studied, the sorption capacity correlated directly with hydrophobicity of HAs and inversely with the number of methyl groups in HA molecules. The plausible binding mechanism of HAs on gamma-PGA may include a combination of hydrophobic, hydrogen-bonding, ionic, and dipole-dipole interactions.


Assuntos
Carbolinas/metabolismo , Mutagênicos/metabolismo , Ácido Poliglutâmico/análogos & derivados , Quinolinas/metabolismo , Quinoxalinas/metabolismo , Adsorção , Carbolinas/química , Fenômenos Químicos , Físico-Química , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Ácido Poliglutâmico/metabolismo , Quinolinas/química , Quinoxalinas/química
17.
J Hazard Mater ; 137(1): 226-34, 2006 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-16540239

RESUMO

Natural polymeric materials are gaining interest for application as adsorbents in wastewater treatment due to their biodegradable and non-toxic nature. In this study, a biopolymer, poly-gamma-glutamic acid (gamma-PGA) derived from bacterial sources (Bacillus species) was evaluated for its efficiency in removing basic dyes from aqueous solution. Sorption studies under batch mode were conducted using C.I. Basic blue 9 (BB9) and C.I. Basic green 4 (BG4) as test dyes. Equilibrium process conformed well with the Redlich-Peterson isotherm equation and the monolayer sorption capacity obtained from the Langmuir model was 352.76 and 293.32mg/g for BB9 and BG4 dyes, respectively. The kinetic studies of dye sorption on gamma-PGA gave high coefficients of determination (>0.98) for a pseudo second-order equation. An ion-exchange model, which assumes adsorption as a chemical phenomenon, was also found to fit the kinetic data precisely. The dye sorption largely depended on the initial pH of the solution with maximum uptake occurring at pH above 5. About 98% of the dye adsorbed on gamma-PGA could be recovered at pH 1, which facilitates the reuse of spent gamma-PGA.


Assuntos
Cátions , Corantes/química , Ácido Poliglutâmico/análogos & derivados , Eliminação de Resíduos Líquidos/métodos , Água/química , Adsorção , Bacillus/metabolismo , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Modelos Químicos , Modelos Estatísticos , Oxigênio/química , Ácido Poliglutâmico/química , Purificação da Água
18.
Hand Surg ; 10(1): 1-5, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16106494

RESUMO

Hand paraesthesia is a common symptom found in patients either with carpal tunnel syndrome or cervical spondylosis. To differentiate between the two conditions, it is important to identify additional diagnostic symptoms. Ninety-two patients with operated carpal tunnel syndrome and 138 patients with spinal surgery for cervical spondylosis were reviewed. After exclusion of cases co-morbid with both cervical spondylosis and carpal tunnel syndrome or other neurological disorders, 44 patients with carpal tunnel syndrome and 41 patients with cervical spondylosis were compared. There were significant differences in the symptomatology between the two groups. In carpal tunnel syndrome, 84% had nocturnal paraesthesia, 82% hand paraesthesia were aggravated by hand activity, and hand pain occurred in 64%. The incidences were only 10%, 7% and 10%, respectively in cervical spondylosis. Neck pain was present in 76% of cervical spondylosis but only in 14% of carpal tunnel syndrome, and lower limb symptoms were present in 44% of cervical spondylosis and only 9% in carpal tunnel syndrome.


Assuntos
Síndrome do Túnel Carpal/diagnóstico , Vértebras Cervicais/fisiopatologia , Osteofitose Vertebral/diagnóstico , Síndrome do Túnel Carpal/fisiopatologia , Síndrome do Túnel Carpal/cirurgia , Diagnóstico Diferencial , Feminino , Mãos/fisiopatologia , Humanos , Extremidade Inferior/fisiopatologia , Masculino , Pessoa de Meia-Idade , Espasticidade Muscular/fisiopatologia , Debilidade Muscular/fisiopatologia , Dor/etiologia , Dor/fisiopatologia , Parestesia/etiologia , Parestesia/fisiopatologia , Osteofitose Vertebral/fisiopatologia , Osteofitose Vertebral/cirurgia
19.
AIDS ; 10(8): F17-22, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8828735

RESUMO

OBJECTIVE: To test the hypothesis that the expanded population of non-proliferative CD28-CD8+ T cells in HIV disease have shortened telomeres, thereby providing evidence that increased rounds of CD8+ cell division occur during HIV disease, possibly leading to replicative senescence and exhaustion of CD8+ T-cell responses. DESIGN: CD8+ cells play a central role in control of HIV infection. In late HIV disease, an expanded population of CD28-CD8+ cells with reduced proliferative potential has been documented. A similar population of CD28-CD8+ cells has been identified in ageing humans, where telomere length measurements have suggested that these cells have reached the irreversible state of replicative senescence. METHODS: CD8+ cells from HIV-infected and control subjects were sorted by flow cytometry into CD28+ and CD28- fractions. Telomere lengths were determined as mean terminal restriction fragment (TRF) lengths by Southern hybridization. RESULTS: The TRF lengths of sorted CD28-CD8+ cells in HIV-infected subjects ranged between 5 and 7 kilobases (kb) and were significantly shorter than TRF lengths of CD28-CD8+ cells in uninfected subjects (P = 0.003). The TRF length in CD28-CD8+ cells from HIV-infected subjects was the same as that observed for centenarian peripheral blood mononuclear cells and is compatible with a state of replicative senescence. CONCLUSIONS: The shortened telomeres in the CD28-CD8+ cells in HIV-infected subjects and the poor proliferative potential of these cells identifies CD8+ cell replicative senescence as a newly described feature of HIV disease. Our results provide a mechanism for the loss of CD8+ cell control of viral replication that accompanies advanced HIV disease. Replicative senescence may contribute to exhaustion of the T-cell response as a result of chronic HIV disease. Whether this phenomenon occurs in other chronic viral infections is unknown.


Assuntos
Antígenos CD28/análise , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , Subpopulações de Linfócitos T/imunologia , Telômero/genética , Linfócitos T CD8-Positivos/química , Linfócitos T CD8-Positivos/citologia , Divisão Celular , Senescência Celular , DNA/análise , Humanos , Peso Molecular , Telômero/química
20.
Diagn Microbiol Infect Dis ; 24(4): 221-3, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8831037

RESUMO

A gram-positive coagulase-positive coccus was isolated from purulent drainage from the carbuncle of a pediatric patient. It shows characteristics typical of Staphylococcus aureus with the exception that catalase activity could not be found.


Assuntos
Carbúnculo/microbiologia , Catalase/biossíntese , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/enzimologia , Técnicas Bacteriológicas , Criança , Meios de Cultura/análise , Feminino , Humanos
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