RESUMO
UNLABELLED: Public health is facing a new challenge due to the alarming increase in bacterial resistance to most of the conventional antibacterial agents. It has been found that only minor cell damage is caused when exposed to sub-lethal levels of antimicrobial. Biofilms can play an important role in producing resistance, which is developed to reservoirs of pathogens in the hospital and cannot be easily removed. The aim of this study was to test whether the sub-lethal dose of antibiotics can induce biofilm formation of P. aeruginosa following incubating in the presence and absence of chlorhexidine. Standard antibiotic-micro broth 96-flat well plates were used for determination of MIC and biofilm assay. The adherence degree of biofilm was determined by estimation of OD 630 nm values using ELISA reader. The mean 22 isolates of P. aeruginosa growing in culture with presence and absence of chlorhexidine, could exhibited the significant (p < 0.001) proportion of adherence followed incubation in sub minimal inhibitory concentrations (Sub-MIC) of cefotaxim, amoxicillin, and azithromycin in comparison with control (antibiotic-free broth), while the sub-MIC of ciprofloxacin revealed significant inhibition of biofilm. CONCLUSION: Incubating the isolates of P. aeruginosa to sub-MIC of antibiotics exhibited induction of biofilm in the presence of chlorhexidine.
Assuntos
Antibacterianos/metabolismo , Anti-Infecciosos/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Clorexidina/metabolismo , Substâncias de Crescimento/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/fisiologiaRESUMO
Public health is facing a new challenge due to the alarming increase in bacterial resistance to most of the conventional antibacterial agents. It has been found that only minor cell damage is caused when exposed to sub-lethal levels of antimicrobial. Biofilms can play an important role in producing resistance, which is developed to reservoirs of pathogens in the hospital and cannot be easily removed. The aim of this study was to test whether the sub-lethal dose of antibiotics can induce biofilm formation of P. aeruginosa following incubating in the presence and absence of chlorhexidine. Standard antibiotic-micro broth 96-flat well plates were used for determination of MIC and biofilm assay. The adherence degree of biofilm was determined by estimation of OD630 nm values using ELISA reader. The mean 22 isolates of P. aeruginosa growing in culture with presence and absence of chlorhexidine, could exhibited the significant (p < 0.001) proportion of adherence followed incubation in sub minimal inhibitory concentrations (Sub-MIC) of cefotaxim, amoxicillin, and azithromycin in comparison with control (antibiotic-free broth), while the sub-MIC of ciprofloxacin revealed significant inhibition of biofilm. Conclusion: Incubating the isolates of P. aeruginosa to sub-MIC of antibiotics exhibited induction of biofilm in the presence of chlorhexidine.
Assuntos
Antibacterianos/metabolismo , Anti-Infecciosos/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Clorexidina/metabolismo , Substâncias de Crescimento/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/fisiologiaRESUMO
Public health is facing a new challenge due to the alarming increase in bacterial resistance to most of the conventional antibacterial agents. It has been found that only minor cell damage is caused when exposed to sub-lethal levels of antimicrobial. Biofilms can play an important role in producing resistance, which is developed to reservoirs of pathogens in the hospital and cannot be easily removed. The aim of this study was to test whether the sub-lethal dose of antibiotics can induce biofilm formation of P. aeruginosa following incubating in the presence and absence of chlorhexidine. Standard antibiotic-micro broth 96-flat well plates were used for determination of MIC and biofilm assay. The adherence degree of biofilm was determined by estimation of OD630 nm values using ELISA reader. The mean 22 isolates of P. aeruginosa growing in culture with presence and absence of chlorhexidine, could exhibited the significant (p < 0.001) proportion of adherence followed incubation in sub minimal inhibitory concentrations (Sub-MIC) of cefotaxim, amoxicillin, and azithromycin in comparison with control (antibiotic-free broth), while the sub-MIC of ciprofloxacin revealed significant inhibition of biofilm. Conclusion: Incubating the isolates of P. aeruginosa to sub-MIC of antibiotics exhibited induction of biofilm in the presence of chlorhexidine.(AU)
Assuntos
Antibacterianos/metabolismo , Anti-Infecciosos/metabolismo , Biofilmes , Biofilmes/crescimento & desenvolvimento , Clorexidina/metabolismo , Substâncias de Crescimento/metabolismo , Pseudomonas aeruginosa , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/fisiologiaRESUMO
Carpospore output and development in the marine red alga Hydropuntia cornea J. Agardh. were increased by adding polyamines (PAs) (putrescine, spermidine and spermine) singly or in combinations at 10(-9), 10(-6) and 10(-3) M. Cell divisions after spore release and development of apical axis between 17 and 21 days characterized carpospore development. PAs increased carpospore development by promoting cell divisions to form cell masses between day 2 and 3. Morphogenesis to develop apical axes occurred at day 7. Spermine at 10(-6) M and a combination of putrescine 10(-9) M + spermidine 10(-9) M + spermine 10(-9) M gave a higher number of carpospores and enhanced their further development to sporelings.
Assuntos
Divisão Celular/efeitos dos fármacos , Substâncias de Crescimento/metabolismo , Poliaminas/metabolismo , Rodófitas/efeitos dos fármacos , Rodófitas/crescimento & desenvolvimento , Esporos/crescimento & desenvolvimento , Fatores de TempoRESUMO
OBJECTIVES: Fetal alcohol syndrome (FAS) is a collection of signs and symptoms seen in children exposed to alcohol in the prenatal period. It is characterized mainly by a distinct pattern of craniofacial malformations, physical and mental retardation. However, with the increased incidence of FAS, there is a great variation in the clinical features of FAS. DESIGN: Narrative review. RESULTS: This review describes data from clinical and experimental studies, and in vitro models. Experimental studies have shown that alcohol has a direct toxic effect on the ectodermal and mesodermal cells of the developing embryo, particularly in the cells destined to give rise to dentofacial structures (i.e. cranial neural crest cells). Other effects, such as, abnormal pattern of cranial and mandibular growth and altered odontogenesis are described in detail. The exact mechanism by which alcohol induces its teratogenic effects remains still unknown. The possible mechanisms are outlined here, with an emphasis on the developing face and tooth. Possible future research directions and treatment strategies are also discussed. CONCLUSION: Early identification of children affected by prenatal alcohol exposure leads to interventions, services, and improved outcomes. FAS can be prevented with the elimination of alcohol consumption during pregnancy. We need to provide education, target high-risk groups, and make this issue a high priority in terms of public health.
Assuntos
Anormalidades Craniofaciais/induzido quimicamente , Transtornos do Espectro Alcoólico Fetal/patologia , Anormalidades Dentárias/induzido quimicamente , Animais , Membrana Celular/efeitos dos fármacos , Fácies , Feminino , Radicais Livres/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Substâncias de Crescimento/metabolismo , Humanos , Crista Neural/efeitos dos fármacos , Gravidez , Tretinoína/metabolismoRESUMO
OBJECTIVE: Although cAMP is involved in a number of physiologic functions, its role in hematopoietic cell fate decision remains poorly understood. We have recently demonstrated that in CD34(+)-derived megakaryocytes, cAMP-related agents prevent apoptosis. In this study we addressed the question of whether cAMP also regulates survival of their precursors, CD34(+) cells. METHODS: Apoptosis was evaluated by fluorescence microscopy, and detection of hypodiploid or annexin V(+) cells by flow cytometry. Mitochondrial membrane potential and bcl-xL or caspase-3 expression were assessed by flow cytometry. Colony-forming units were studied by clonogenic assays in methylcellulose. RESULTS: We found that two different cAMP analogs such as Dibutiril-cAMP and sp-5,6-DCl-BIMPS (BIMPS) promoted survival of human umbilical cord-derived CD34(+) cells by suppressing apoptosis induced by either nitric oxide (NO) or serum deprivation. Involvement of PKA and PI3K pathway was demonstrated by the ability of their specific inhibitors Rp-cAMP and Wortmannin or LY294002 respectively to reverse the antiapoptotic effect of BIMPS. Treatment of CD34(+) cell with BIMPS not only restrained the bcl-xL downregulation but also suppressed the loss of mitochondrial membrane potential and caspase-3 activation induced by serum starvation. While thrombopoietin (TPO), granulocyte colony-stimulating factor (G-CSF) or stem cell factor (SCF) were not able to increase cAMP levels, the antiapoptotic activity exerted by these growth factors was blocked by inhibition of the adenylate cyclase and synergized by BIMPS. Cyclic AMP analogs suppressed the decreased colony formation in cells exposed to NO or serum deprivation. CONCLUSION: Altogether, our results strongly suggest that cAMP appears to be not only a key pathway controlling CD34(+) survival, but also a mediator of the TPO-, G-CSF- and SCF-mediated cytoprotection.
Assuntos
Antígenos CD34 , Apoptose/efeitos dos fármacos , Bucladesina/farmacologia , Diclororribofuranosilbenzimidazol/análogos & derivados , Células-Tronco Hematopoéticas/metabolismo , Megacariócitos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tionucleotídeos/farmacologia , Bucladesina/metabolismo , Caspase 3 , Caspases/metabolismo , Células Cultivadas , Cromonas/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Diclororribofuranosilbenzimidazol/farmacologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Inibidores Enzimáticos/farmacologia , Sangue Fetal/citologia , Sangue Fetal/metabolismo , Substâncias de Crescimento/metabolismo , Células-Tronco Hematopoéticas/citologia , Humanos , Megacariócitos/citologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Mitocôndrias/metabolismo , Morfolinas/farmacologia , Óxido Nítrico/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais/fisiologia , Proteína bcl-X/biossínteseRESUMO
OBJECTIVE: To determine DNA fragmentation and several molecules associated with apoptosis or proliferation in ovaries of patients with diminished ovarian reserve. DESIGN: Cross-sectional analysis. SETTING: Tertiary institutional hospital. PATIENT(S): Patients with benign uterine pathology who had undergone a hysterectomy and oophorectomy were categorized by the citrate clomiphene challenge test in diminished ovarian reserve or control group. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Apoptosis was determined using TUNEL (terminal deoxynucleotidyl transferase biotin-dUTP nick end-labeling) assay and p53, p27, Bax, caspase-3, caspase-8, caspase-9, Fas-L, Bcl-2, GATA-4, Ki-67, proliferating-cell nuclear antigen (PCNA), estrogen receptor, P receptor, and androgen receptor expression by immunohistochemistry. RESULT(S): Fifteen patients were studied. DNA fragmentation and expression of Bax, caspase-3, caspase-8, caspase-9, Fas-L, Bcl-2, GATA-4, Ki-67, and PCNA were observed in the whole ovary in both groups. In the control group, the expression of caspase-3 and caspase-8 in the ovarian stroma was significantly higher. CONCLUSION(S): DNA fragmentation and the expression of several molecules that participate in ovarian proliferation or apoptosis are present in cycling ovaries, but these markers were not significantly different in patients with diminished ovarian reserve. Thus, the mechanism leading to diminished ovarian reserve does not involve an easily detectable dysregulation in apoptosis or proliferation of ovarian follicles.
Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Substâncias de Crescimento/metabolismo , Infertilidade Feminina/metabolismo , Infertilidade Feminina/patologia , Ovário/metabolismo , Ovário/patologia , Adulto , Apoptose , Biomarcadores/metabolismo , Proliferação de Células , Células Cultivadas , Estudos Transversais , Feminino , Humanos , Técnicas In VitroRESUMO
Sulfated polysaccharides are capable of binding with proteins at several levels of specificity. As highly acidic macromolecules, they can bind non-specifically to any basic patch on a protein surface at low ionic strength, and such interactions are not likely to be physiologically significant. On the other hand, several systems have been identified in which very specific substructures of sulfated polysaccharides confer high affinity for particular proteins; the best-known example of this is the pentasaccharide in heparin with high affinity for antithrombin, but other examples may be taken from the study of marine invertebrates: the importance of the fine structure of dermatan sulfate (DS) to its interaction with heparin cofactor II (HCII), and the involvement of sea urchin egg-jelly fucans in species specific fertilization. A third, intermediate, kind of specific interaction is described for the cell-surface glycosaminoglycan heparan sulfate (HS), in which patterns of sulfate substitution can show differential affinities for cytokines, growth factors, and morphogens at cell surfaces and in the intracellular matrix. This complex interplay of proteins and glycans is capable of influencing the diffusion of such proteins through tissue, as well as modulating cellular responses to them.
Assuntos
Polissacarídeos/metabolismo , Proteínas/metabolismo , Sulfatos/metabolismo , Animais , Antitrombinas/metabolismo , Dermatan Sulfato/química , Dermatan Sulfato/metabolismo , Interações Medicamentosas , Substâncias de Crescimento/metabolismo , Heparina/química , Heparina/metabolismo , Polissacarídeos/química , Proteínas/química , Ouriços-do-Mar , Sulfatos/químicaRESUMO
The study was undertaken to analyze the rate of uptake and utilization of various amino acids by Azospirillum brasilense Sp81 (RG) in a basal mineral salts solution under non-nitrogen fixing condition. These amino acids including other nitrogenous compounds were tested for both N- and C-sources. The kinetic constants (Km and Vmax) of uptake of some amino acids (e.g. lysine, arginine, proline, glutamine and glutamic acid) were exploited using a Hanes-Woolf plot, and discussed in the context of nitrogen starvation or both carbon and nitrogen starvation. To summarize all the kinetic data for these amino acids strongly suggested that the mode of these amino acids utilization in this bacterium followed the same general pattern, although the quantitative differences were there. A single amino acid was able to satisfy the nitrogen needs of this bacterium in basal mineral salts solution, and this possibility could be considered for the cost-effective growth medium for this bacterium in the biotechnological industry.
Assuntos
Aminoácidos/metabolismo , Azospirillum brasilense/metabolismo , Substâncias de Crescimento/metabolismo , Aminoácidos/fisiologia , Azospirillum brasilense/fisiologia , Carbono/metabolismo , Substâncias de Crescimento/fisiologia , CinéticaRESUMO
Os polissacarídeos sulfatados são capazes de se ligar às proteínas com diferentes níveis de especificidade. São macromoléculas altamente ácidas que podem se ligar de forma inespecífica a qualquer domínio básico da superfície de uma proteína em soluções com baixa força iônica, contudo tais interações não parecem ser fisiologicamente significativas. Por outro lado, foram identificados vários sistemas nos quais componentes estruturais muito específicos dos polissacarídeos sulfatados conferem alta afinidade para algumas proteínas. O exemplo mais conhecido é o pentassacarídeo da heparina com alta afinidade pela antitrombina. Outros exemplos podem ser observados no estudo de invertebrados marinhos, tais como a importância da estrutura fina do dermatam sulfato para sua interação com o cofator II da heparina e o envolvimento defucanas sulfatadas encontradas no gel que envolve osóvulos dos ouriços-do-mar na espécie especificidade da fertilização. Um terceiro exemplo de interação específica é aquele descrito para o glicosaminoglicano heparam sulfato encontrado na superfície celular. Neste caso, o padrão de sulfatação pode determinar diferentes afinidades do carboidrato por citoquinas, fatores de crescimento e outras proteínas encontradas na superfície celular e na matriz extracelular. Estas interações complexas entre proteínas e carboidratos são capazes de influenciar a difusão das proteínas através dos tecidos, assim como modelar a resposta celular a estas moléculas.