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1.
J Food Sci Technol ; 56(9): 4045-4056, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31477976

RESUMO

In this work, mint essential oil (MEO) was added into gelatin films and antifungal activity was evaluated. Five concentrations of MEO (0, 0.06, 0.13, 0.25, 0.38, 0.50% (g/g gelatin)) were incorporated into gelatin solutions. The films were prepared by casting and characterized for their barrier properties, mechanical resistance, morphology, thermal and antifungal activity. The addition of oil into the solution slightly improved water vapor barrier, increased thickness and opacity, decreased transparency and modified thermal and mechanical properties of films. With addition of oil above 0.38%, the films were effective against the growth of Botrytis cinerea and Rhizopus stolonifer, indicating an inhibitory activity. Thus, gelatin-based edible films incorporated with MEO showed to be an effective way to inhibit microbial growth on the film surface.

2.
Lett Appl Microbiol ; 66(3): 252-259, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29327464

RESUMO

Ethylene acts as an inhibitor of the nodulation process of leguminous plants. However, some bacteria can decrease deleterious ethylene levels by the action of the enzyme 1-aminocyclopropane-1-carboxylate (ACC) deaminase which degrades ACC, the ethylene precursor in all higher plants. Co-inoculation of rhizobia with endophytes enhances the rhizobial symbiotic efficiency with legumes, improving both nodulation and nitrogen fixation. However, not much is understood about the mechanisms employed by these endophytic bacteria. In this regard, the role of ACC deaminase from endophytic strains in assisting rhizobia in this process has yet to be confirmed. In this study, the role of ACC deaminase in an endophyte's ability to increase Rhizobium tropici nodulation of common bean was evaluated. To assess the effect of ACC deaminase in an endophyte's ability to promote rhizobial nodulation, the endophyte Serratia grimesii BXF1, which does not encode ACC deaminase, was transformed with an exogenous acdS gene. The results obtained indicate that the ACC deaminase-overexpressing transformant strain increased common bean growth, and enhanced the nodulation abilities of R. tropici CIAT899, in both cases compared to the wild-type non-transformed strain. Furthermore, plant inoculation with the ACC deaminase-overproducing strain led to an increased level of plant protection against a seed-borne pathogen. SIGNIFICANCE AND IMPACT OF THE STUDY: In this work, we studied the effect of ACC deaminase production by the bacterial endophyte Serratia grimesi BXF1, and its impact on the nodulation process of common bean. The results obtained indicate that ACC deaminase is an asset to the synergetic interaction between rhizobia and the endophyte, positively contributing to the overall legume-rhizobia symbiosis by regulating inhibitory ethylene levels that might otherwise inhibit nodulation and overall plant growth. The use of rhizobia together with an ACC deaminase-producing endophyte is, therefore, an important strategy for the development of new bacterial inoculants with increased performance.


Assuntos
Proteínas de Bactérias/metabolismo , Carbono-Carbono Liases/metabolismo , Phaseolus/crescimento & desenvolvimento , Nodulação/fisiologia , Rhizobium tropici/metabolismo , Nódulos Radiculares de Plantas/microbiologia , Serratia/enzimologia , Inoculantes Agrícolas , Endófitos/metabolismo , Etilenos/metabolismo , Phaseolus/microbiologia , Serratia/genética , Serratia/metabolismo , Simbiose
3.
Environ Sci Technol ; 50(6): 2946-55, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26886850

RESUMO

Surface functional groups of two different types of combustion aerosols, a conventional diesel (EN 590) and a hydrotreated vegetable oil (HVO) soot, have been investigated using heterogeneous chemistry (i.e., gas-particle surface reactions). A commercial sample of amorphous carbon (Printex XE2-B) was analyzed as a reference substrate. A Knudsen flow reactor was used to carry out the experiments under molecular flow conditions. The selected gases for the titration experiments were: N(CH3)3 for the identification of acidic sites, NH2OH for the presence of carbonyl groups, CF3COOH and HCl for basic sites of different strength, and O3 and NO2 for reducing groups. Reactivity with N(CH3)3 indicates a lower density of acidic functionalities for Printex XE2-B in relation to diesel and HVO soot. Results for NH2OH experiments indicates that commercial amorphous carbon exhibits a lower abundance of available carbonyl groups at the interface compared to the results from diesel and HVO soot, the latter being the one with the largest abundance of carbonyl functions. Reactions with acids indicate the presence of weak basic oxides on the particle surface that preferentially interact with the strong acid CF3COOH. Finally, reactions with O3 and NO2 reveal that diesel and especially HVO have a significantly higher reactivity with both oxidizers compared to that of Printex XE2-B because they have more reducing sites by roughly a factor of 10 and 30, respectively. The kinetics of titration reactions have also been investigated.


Assuntos
Aerossóis/análise , Poluentes Atmosféricos/química , Fuligem/química , Emissões de Veículos/análise , Gases , Óleos de Plantas/química
4.
J Phys Chem A ; 118(28): 5135-48, 2014 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-24942181

RESUMO

A reinvestigation of the absolute rate constant of the metathesis reactions t-C4H9• + HBr → i-C4H10 + Br• (1) and t-C4H9• + HI → i-C4H10 + I• (2) was performed thanks to a recently developed apparatus consisting of a Knudsen reactor coupled to detection based on single-photon (VUV) photoionization mass spectrometry (SPIMS). It enables the generation of thermalized hydrocarbon free radicals owing to a source upstream of and external to the Knudsen reactor. The following Arrhenius expressions were obtained: k1 = 5.6(±1.4) × 10(­12) exp(−6.76(±0.94)/(RT)) and k2 = 2.0(±0.6) × 10(­11) exp(−8.48(±0.94)/(RT)) with R = 8.314 J mol(­1) K(­1) over the range 293 to 623 K. The mass balance of the reaction system based on closed shell product detection (CSPD) was checked in order to ensure the accuracy of the used reaction mechanism and as an independent check of k1 and k2. The wall-loss rate constants of the t-butyl free radical, kw(C4H9), were measured and found to be low compared with the corresponding escape rate constant, ke(C4H9), for effusion of t-C4H9• out of the Knudsen reactor. On the basis of the present results, the free radical standard heat of formation ΔfH298°(t-C4H9•) = 44.3 ± 1.7 kJ mol(­1) was obtained when combined with the kinetics of the inverse halogenation reaction taken from the literature and using S298°(t-C4H9•) = 322.2 J K(­1) mol(­1) following a "Third Law" evaluation method. The standard enthalpy for t-butyl free radical is consistent for both the bromination and iodination reactions within the stated uncertainties.

5.
Antimicrob Agents Chemother ; 57(6): 2541-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23507287

RESUMO

Agaricus brasiliensis (syn. A. subrufescens), a basidiomycete fungus native to the Atlantic forest in Brazil, contains cell walls rich in glucomannan polysaccharides. The ß-(1 → 2)-gluco-ß-(1 → 3)-mannan was isolated from A. brasiliensis mycelium, chemically modified by sulfation, and named MI-S. MI-S has multiple mechanisms of action, including inhibition of herpes simplex virus (HSV) attachment, entry, and cell-to-cell spread (F. T. G. S. Cardozo, C. M. Camelini, A. Mascarello, M. J. Rossi, R. J. Nunes, C. R. Barardi, M. M. de Mendonça, and C. M. O. Simões, Antiviral Res. 92:108-114, 2011). The antiherpetic efficacy of MI-S was assessed in murine ocular, cutaneous, and genital infection models of HSV. Groups of 10 mice were infected with HSV-1 (strain KOS) or HSV-2 (strain 333). MI-S was given either topically or by oral gavage under various pre- and posttreatment regimens, and the severity of disease and viral titers in ocular and vaginal samples were determined. No toxicity was observed in the uninfected groups treated with MI-S. The topical and oral treatments with MI-S were not effective in reducing ocular disease. Topical application of MI-S on skin lesions was also not effective, but cutaneously infected mice treated orally with MI-S had significantly reduced disease scores (P < 0.05) after day 9, suggesting that healing was accelerated. Vaginal administration of MI-S 20 min before viral challenge reduced the mean disease scores on days 5 to 9 (P < 0.05), viral titers on day 1 (P < 0.05), and mortality (P < 0.0001) in comparison to the control groups (untreated and vehicle treated). These results show that MI-S may be useful as an oral agent to reduce the severity of HSV cutaneous and mucosal lesions and, more importantly, as a microbicide to block sexual transmission of HSV-2 genital infections.


Assuntos
Agaricus/química , Antivirais/uso terapêutico , Polissacarídeos Fúngicos/farmacologia , Herpes Simples/tratamento farmacológico , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Animais , Antivirais/farmacologia , Chlorocebus aethiops , Feminino , Polissacarídeos Fúngicos/química , Herpes Genital/tratamento farmacológico , Herpes Genital/virologia , Herpes Simples/virologia , Humanos , Ceratite Herpética/tratamento farmacológico , Ceratite Herpética/virologia , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana/métodos , Sulfatos , Resultado do Tratamento , Células Vero
6.
Br J Anaesth ; 110 Suppl 1: i39-46, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23592692

RESUMO

BACKGROUND: Many anaesthetics when given to young animals cause cell death and learning deficits that persist until much later in life. Recent attempts to compare the relative safety or toxicity between different agents have not adequately controlled for the relative dose of anaesthetic given, thereby making direct comparisons difficult. METHODS: Isoflurane or sevoflurane were given at 1 minimum alveolar concentration (MAC) for 4 h to postnatal day 7 (P7) rat pups. Beginning at P75 these animals underwent fear conditioning and at P83 Morris water maze testing to assess working memory, short-term memory and early long-term memory using delays of 1 min, 1 h, and 4 h. RESULTS: No difference between groups was seen in fear conditioning experiments. Morris water maze learning was equivalent between groups, and no difference was seen in working memory. Sevoflurane-treated animals had a deficit in early long-term memory, and isoflurane-treated animals had a deficit in both short-term and early long-term memory. CONCLUSIONS: Both isoflurane and sevoflurane delivered at 1 MAC for 4 h to immature rats caused a deficit in long-term memory. Isoflurane also caused a deficit in short-term memory. Isoflurane might be more detrimental than sevoflurane in very young animals.


Assuntos
Anestésicos Inalatórios/toxicidade , Isoflurano/toxicidade , Transtornos da Memória/induzido quimicamente , Éteres Metílicos/toxicidade , Anestésicos Inalatórios/administração & dosagem , Animais , Animais Recém-Nascidos , Condicionamento Clássico , Esquema de Medicação , Isoflurano/administração & dosagem , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/psicologia , Memória de Longo Prazo/efeitos dos fármacos , Memória de Curto Prazo/efeitos dos fármacos , Éteres Metílicos/administração & dosagem , Testes Neuropsicológicos , Ratos , Ratos Sprague-Dawley , Tempo de Reação/efeitos dos fármacos , Sevoflurano
7.
J Phys Chem A ; 117(45): 11383-402, 2013 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-24134055

RESUMO

A reinvestigation of the absolute rate constants of the metathesis reactions C2H5• + HBr → C2H6 + Br• (R1) and C2H5• + HI → C2H6 + I• (R2) has been performed and led to the following Arrhenius expressions: k1 = 3.69(±0.95) × 10­11 exp(−10.62(±0.66)/RT), k2 = 1.20(±0.38) × 10­11 exp(−7.12(±1.059)/RT) in the temperature range 293­623 K (A/cm3 molecule­1 s­1, Ea/kJ mol­1). The study has been performed using a Knudsen reactor coupled to single-photon (VUV) photoionization mass spectrometer (SPIMS). Hydrocarbon free radicals have been generated externally before admission into the Knudsen reactor according to two different chemical schemes, enabling the generation of thermalized C2H5• free radicals. A minor correction to k1 and k2 for the wall loss of C2H5• (kw) has been applied throughout the temperature range. The obtained results are consistent regarding both the disappearance of C2H5• and the formation of closed shell products (n-C4H10, C2H4, C2H6), indicating that the chemical mechanism is largely understood and complete. Thermochemical parameters for C2H5• free radical resulting from the present kinetic measurements are discussed and point toward a slightly lower value for the standard heat of formation ΔfH298°(C2H5•) compared to some presently recommended values. On the basis of the present results and suitable data on the reverse reaction taken from the literature, we recommend ΔfH298°(C2H5•) = 117.3 ± 3.1 kJ/mol resulting from an average of "third law" evaluations using S298°(C2H5•) = 242.9 ± 4.6 J/K mol. The present work yields a standard heat of formation in satisfactory agreement with the results obtained by W. Tsang (ΔfH298°(C2H5•) = 119 ± 2 kJ/mol) despite using two very different experimental techniques.

8.
Appl Microbiol Biotechnol ; 97(1): 123-33, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22820522

RESUMO

The interest upon products obtained from fungi has increased during the recent years. Among the most noticeable, nutraceuticals, enzymes, and natural drugs occupy a privileged position. Fungal biomass for the obtainment of those products can be produced either by solid-state fermentation (SSF) or submersed fermentation. SSF has been employed for the production of spawn on pretreated wheat grains with the objective of increasing the fungal polysaccharide (glucomannans) contents. Among the important factors for the production of spawn, time of cooking, time of resting after grain cooking, consequently grain moisture, substrate pH, temperature of incubation, and initial inoculum amount are among the most significant. For wheat grains, cooking time of 21 min followed by a 24-min resting time has been shown as optimal for the production of glucomannans by the fungus Agaricus subrufescens (=Agaricus brasiliensis). Amendments of CaSO(4) (up to 3 %) and CaCO(3) (up to 1 %) had an important influence on the substrate pH. In general, better results for glucomannan production were obtained when no supplement was added or when up to 0.25 % CaCO(3) (pH 6.6) has been added to the mix. Our results demonstrate that the inoculum amount necessary for the best polysaccharide levels is around 10.3 %, while the best temperature is around 27.2 °C. Besides using the spawn for its main purpose, it could potentially and alternatively be used as nutraceutical due to the high levels of glucomannan observed (6.89 %), a compound technically proven to be a potent immunostimulatory and antitumoral agent.


Assuntos
Agaricus/metabolismo , Mananas/metabolismo , Triticum/metabolismo , Carbonato de Cálcio/metabolismo , Sulfato de Cálcio/metabolismo , Meios de Cultura/química , Fermentação , Concentração de Íons de Hidrogênio , Temperatura , Fatores de Tempo
9.
Appl Microbiol Biotechnol ; 97(23): 9993-10002, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24077725

RESUMO

A simplified submerged airlift cultivation was established for the production of biomass from Agaricus subrufescens. In this work, soluble polysaccharides extracted from fungal mycelium, fruiting bodies, and the residual culture media were concentrated by nanofiltration. Total and high molar mass polysaccharides and soluble solids were determined in the concentrate for the three extracts. Additionally, the permeate flow, the influences of temperature and pressure, and the resistance to the permeate flow during filtration were also evaluated. Ayield of 5.5 g/L of biomass with 35%glucose conversion was obtained when 0.5 g/L of initial inoculum was employed. Average specific speed of growth was 0.4/day, with biomass productivity of about 0.76 g/(L day). Nanofiltration has yielded polysaccharide increases of 85, 82, and 92% in the extracts from fruiting bodies, mycelium, and liquid media, respectively. A reduction in the permeate flow was observed during filtration, and it was compensated by higher pressures and temperatures. The higher resistance to the permeate flux was caused by polarization due to concentration (polarized gel layer), reaching values of 88% for the culture media. Maximal resistance caused by the membrane reached values of 40% for the extract from the fruiting bodies. On the other hand, resistance caused by fouling was responsible for less than 3.5%. In conclusion, nanofiltration is efficient to concentrate these functional compounds extracted from A. subrufescens and can, therefore, be applied in different biotechnological areas.


Assuntos
Agaricus/metabolismo , Filtração/métodos , Polissacarídeos/isolamento & purificação , Polissacarídeos/metabolismo , Agaricus/química , Agaricus/crescimento & desenvolvimento , Meios de Cultura/química , Meios de Cultura/metabolismo , Fermentação , Carpóforos/química , Carpóforos/crescimento & desenvolvimento , Carpóforos/metabolismo , Peso Molecular , Micélio/química , Micélio/crescimento & desenvolvimento , Micélio/metabolismo , Polissacarídeos/química
10.
Science ; 240(4855): 1018-21, 1988 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-17731714

RESUMO

The reactions of dinitrogen pentoxide (N(2)O(5)) with H(2)O and hydrochloric acid (HCl) were studied on ice surfaces in a Knudsen cell flow reactor. The N(2)O(5) reacted on ice at 185 K to form condensed-phase nitric acid (HNO(3)). This reaction may provide a sink for odd nitrogen (NO(x)) during the polar winter, a requirement in nearly all models of Antarctic ozone depletion. A lower limit to the sticking coefficient, gamma, for N(2)O(5) on ice is 1 x 10(-3). Moreover, N(2)O(5) reacted on HCl-ice surfaces at 185 K, with gamma greater than 3 x 10(-3). This reaction, which produced gaseous nitryl chloride (ClNO(2)) and condensed-phase HNO(3), proceeded until all of the HCl within the ice was depleted. The ClNO(2), which did not react or condense on ice at 185 K, can be readily photolyzed in the Antarctic spring to form atomic chlorine for catalytic ozone destruction cycles. The other photolysis product, gaseous nitrogen dioxide (NO(2)), may be important in the partitioning of NO(x) between gaseous and condensed phases in the Antarctic winter.

11.
Science ; 238(4831): 1258-60, 1987 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-17744363

RESUMO

Laboratory studies of heterogeneous reactions important for ozone depletion over Antarctica are reported. The reaction of chlorine nitrate (ClONO(2)) with H(2)0 and hydrogen chloride (HCl) on surfaces that simulate polar stratospheric clouds [ice and nitric acid (HNO(3))-ice and sulfuric acid] are studied at temperatures relevant to the Antarctic stratosphere. The reaction of ClONO(2) on ice and certain mixtures of HNO(3) and ice proceeded readily. The sticking coefficient of ClONO(2) on ice of 0.009 +/- 0.002 was observed. A reaction produced gas-phase hypochlorous acid (HOCl) and condensed-phase HNO(3); HOC1 underwent a secondary reaction on ice producing dichlorine monoxide (Cl(2)O). In addition to the reaction with H(2)0, ClONO(2) reacted with HCl on ice to form gas-phase chlorine (Cl(2)) and condensed-phase HNO(3.) Essentially all of the HCl in the bulk of the ice can react with ClONO(2) on the ice surface. The gaseous products of the above reactions, HOCl, Cl(2)0, and Cl(2), could readily photolyze in the Antarctic spring to produce active chlorine for ozone depletion. Furthermore, the formation of condensed-phase HNO(3) could serve as a sink for odd nitrogen species that would otherwise scavenge the active chlorine.

12.
Sci Total Environ ; 644: 1399-1408, 2018 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-30743852

RESUMO

An improved understanding of the drivers controlling infiltration patterns in semiarid regions is of key importance, as they have important implications for ecosystem productivity, retention of resources and the restoration of degraded areas. The infiltration depth variability (ΔInf) in vegetation patches at the hillslope scale can be driven by different factors along the hillslope. Here we investigate the effects of vegetation and terrain attributes under hypothesis that these attributes exert a major control in ΔInf within the patches. We characterise the ΔInf within vegetation patches at a semiarid hillslope located at the Jornada Experimental Range at dry antecedent conditions preceding two winter frontal rainfall events. We measured these events that are typical during winter conditions, and are characterised by low intensity (0.67 and 4.48 mm h-1) and a total rainfall of 10.4 and 4.6 mm. High precision geo-referenced wetting front depth measurements were taken at various locations within the vegetation patches using differential GPS. Vegetation and terrain attributes were analysed to explain the ΔInf among the vegetation patches. The infiltration depths in the periphery of the patches were in general considerably deeper than those in the centre. The observations suggest that the upslope margin of the patches received additional water in the form of runon from upslope adjacent bare soil. Patch orientation with regard to the slope dictated the effect of the rest of the patch attributes and the distance to the hillslope crest on ΔInf. We found that primarily patch orientation, followed by shape and size modulate lateral surface water transport through their effects on overland flow paths and water retention; something that would be obscured under more simplistic characterisations based on bare versus uniform vegetated soil discrimination.

13.
Environ Sci Pollut Res Int ; 24(8): 7534-7543, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28116624

RESUMO

A chemical characterization of diesel and hydrotreated vegetable oil (HVO) soot has been developed using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) before and after the reaction with different probe gases. Samples were generated under combustion conditions corresponding to an urban operation mode of a diesel engine and were reacted with probe gas-phase molecules in a Knudsen flow reactor. Specifically, NH2OH, O3 and NO2 were used as reactants (probes) and selected according to their reactivities towards specific functional groups on the sample surface. Samples of previously ground soot were diluted with KBr and were introduced in a DRIFTS accessory. A comparison between unreacted and reacted soot samples was made in order to establish chemical changes on the soot surface upon reaction. It was concluded that the interface of diesel and HVO soot before reaction mainly consists polycyclic aromatic hydrocarbons, nitro and carbonyl compounds, as well as ether functionalities. The main difference between both soot samples was observed in the band of the C=O groups that in diesel soot was observed at 1719 cm-1 but not in HVO soot. After reaction with probe gases, it was found that nitro compounds remain on the soot surface, that the degree of unsaturation decreases for reacted samples, and that new spectral bands such as hydroxyl groups are observed.


Assuntos
Óleos de Plantas , Fuligem , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Gases/química , Óleos de Plantas/análise , Óleos de Plantas/química , Hidrocarbonetos Policíclicos Aromáticos/química , Fuligem/análise , Fuligem/química
14.
Environ Sci Pollut Res Int ; 22(7): 4863-72, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24807246

RESUMO

Two gases, O3 and NO2, were selected to probe the surface of a diesel fuel combustion aerosol sample, diesel soot, and amorphous carbon nanoparticles (PRINTEX XE2-B) using heterogeneous (i.e., gas-surface reactions). The gas uptake to saturation of the probes was measured under molecular flow conditions using a Knudsen flow reactor in order to quantify and characterize surface functional groups. Specifically, O3 and NO2 are used for the titration of oxidizable groups. Diesel soot samples interacted with the probe gases to various extents which points to the coexistence of different functional groups on the same aerosol surface such as reduced groups. The carbonaceous particles displayed significant differences: PRINTEX XE2-B amorphous carbon had a significantly lower surface functional group density of both total and strongly reducing groups despite its significantly larger internal surface area, compared to diesel soot. The uptake kinetics of the gas-phase probe molecules (uptake probabilities) were also measured in order to obtain further information on the reactivity of emitted soot aerosols in order to enable the potential prediction of health effects.


Assuntos
Carbono/química , Nanopartículas/química , Dióxido de Nitrogênio/química , Ozônio/química , Fuligem/química , Aerossóis , Gasolina
15.
Endocrinology ; 130(4): 2373-85, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1312455

RESUMO

Human endometrial tissue and primary stromal cell culture contain immunoreactive epidermal growth factor (EGF), platelet-derived growth factor (PDGF)-AB as well as EGF and PDGF-beta receptors. The immunostaining for EGF, EGF receptor, and PDGF beta-receptor were associated with endometrial luminal and glandular epithelial and stromal cells, whereas only the stromal cells contain immunoreactive PDGF-AB. The immunostaining intensity of EGF, EGF receptor, and PDGF-AB was similar in both phases of the menstrual cycle, whereas, PDGF-beta receptor immunostaining was highest in proliferative phase and considerably reduced, particularly in luminal and glandular epithelial cells in the secretory phase. In addition primary stromal cell cultures express EGF, PDGF-AB, and contain EGF and PDGF-beta receptors, and very low levels of PDGF-alpha receptor. 3H-Thymidine incorporation indicate that after 48 h of incubation in serum-free medium approximately 75-80% of stromal cells are quiescent. Incubation of quiescent stromal cells with 10% fetal bovine serum stimulate 3H-thymidine incorporation in a time-dependent manner reaching maximal after 30-48 h, with a doubling time of 38.2 h. EGF (1.5-15 ng/ml) stimulates 3H-thymidine incorporation by quiescent stromal cells (P less than 0.001). This effect was significantly reduced at concentrations above 15 ng/ml (P less than 0.005). PDGF-AB (3-10 ng/ml) and PDGF-BB (0.5-10 ng/ml) also stimulate 3H-thymidine incorporation in quiescent stromal cells compared to controls (P less than 0.005). The action of EGF (15 ng/ml) and PDGF-AB (10 ng/ml) was time dependent, reaching maximal after 36 and 48 h of incubation (P less than 0.002). Addition of PDGF-AB (10 ng/ml) to EGF (15 ng/ml) significantly enhanced the action of EGF or PDGF-AB used individually (P less than 0.001). 17 beta-estradiol or progesterone at 1 microM did not stimulate 3H-thymidine incorporation, although they were stimulatory in combination (P less than 0.001), they did not alter the action of EGF or PDGF when added in combination. These observations provide further evidence that human endometrial tissue contains specific immunoreactive EGF receptors. It also demonstrates the presence of immunoreactive EGF, PDGF-AB, and PDGF-beta receptors in endometrial tissue as well as stromal cells in primary culture. Both EGF and PDGF are mitogenic for endometrial stromal cells, suggesting an autocrine/paracrine role in modulation of endometrial cell growth and differentiation.


Assuntos
Endométrio/química , Fator de Crescimento Epidérmico/análise , Receptores ErbB/análise , Fator de Crescimento Derivado de Plaquetas/análise , Receptores de Superfície Celular/análise , Divisão Celular/efeitos dos fármacos , Separação Celular , DNA/biossíntese , Endométrio/citologia , Endométrio/efeitos dos fármacos , Fator de Crescimento Epidérmico/farmacologia , Estradiol/farmacologia , Feminino , Imunofluorescência , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Fator de Crescimento Derivado de Plaquetas/farmacologia , Progesterona/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas
16.
Endocrinology ; 130(3): 1716-27, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1311246

RESUMO

Immunohistochemical observations indicate that human myometrial smooth muscle cells express epidermal growth factor (EGF) and platelet-derived growth factor (PDGF)-AB and contain EGF and PDGF-beta receptors with no variation in intensity with phases of the menstrual cycle. Furthermore, immunofluorescent microscopic studies revealed that primary myometrial smooth muscle cell cultures also express EGF, PDGF-AB, and contain EGF and PDGF-beta, but not alpha-receptor. Incubation of subconfluent smooth muscle cells in serum-free medium leads to quiescence within 48 h as demonstrated by 3H-thymidine incorporation and labeling index. Exposure of quiescent cells to 10% fetal bovine serum stimulates resumption of DNA synthesis and proliferation in a time-dependent manner with a doubling time of 41.6 h. EGF (1.5-50 ng/ml) and PDGF-AB (1-10 ng/ml) in a dose- and time-dependent manner significantly stimulated 3H-thymidine incorporation by quiescent myometrial smooth muscle cells (P less than 0.05). Combinations of EGF (15 ng/ml) and PDGF-AB (10 ng/ml) significantly increased 3H-thymidine incorporation induced by either growth factor alone (P less than 0.05). PDGF-BB at 10 ng/ml also stimulated 3H-thymidine incorporation and its effect was similar to that induced by PDGF-AB at the same concentration. 17 beta-Estradiol (E2) at 1 microM inhibited 3H-thymidine incorporation by the smooth muscle cells (P less than 0.05). E2 also reduced the stimulatory effect of EGF (15 ng/ml) and PDGF (3 ng/ml). Progesterone at 1 microM either alone or in combination with E2 did not have any effect on 3H-thymidine incorporation or alter the mitogenic action of EGF and PDGF. The effect of EGF and PDGF on cell growth and 3H-thymidine incorporation by myometrial smooth muscle cells was independent of phases of the menstrual cycle. In summary, the results of present studies indicate that human myometrial tissue and myometrial smooth muscle cells in primary culture locally produce EGF and PDGF-AB and contain EGF and PDGF-beta, but not alpha-receptors. Moreover, the myometrial smooth muscle cells in culture respond to the mitogenic action of EGF and PDGF.


Assuntos
Fator de Crescimento Epidérmico/análise , Receptores ErbB/análise , Músculo Liso/química , Miométrio/química , Fator de Crescimento Derivado de Plaquetas/análise , Receptores de Superfície Celular/análise , Autorradiografia , Divisão Celular , Células Cultivadas , DNA/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Feminino , Imunofluorescência , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Músculo Liso/citologia , Músculo Liso/ultraestrutura , Miométrio/citologia , Miométrio/ultraestrutura , Fator de Crescimento Derivado de Plaquetas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas , Timidina/metabolismo , Trítio
17.
Endocrinology ; 135(1): 450-9, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8013384

RESUMO

Reverse transcription-polymerase chain reaction analysis of total RNA and immunocytochemical observations revealed that human endometrial glandular epithelial and stromal cells in primary culture express messenger RNAs and proteins for transforming growth factor-beta 1 (TGF beta 1), TGF beta 2, and TGF beta 3 as well as TGF beta type II receptor. The epithelial and stromal cells synthesize and secrete into their culture-conditioned medium 2.6 +/- 0.3 and 1.4 +/- 0.2 ng TGF beta 1/10(6) cells, respectively; after transient acidification of the medium, the TGF beta 1 levels were 18.1 +/- 0.4 and 7.8 +/- 0.7 ng/10(6) cells. These cells also contain specific binding sites for [125I]TGF beta 1, indicated by light microscope autoradiography. TGF beta s at 0.01-10 ng/ml neither stimulated or inhibited subconfluent quiescent stromal cells under serum-free condition nor altered the mitogenic action of 10% fetal bovine serum. However, in the presence of 2% fetal bovine serum, which induced half-maximal stimulation of [3H]thymidine incorporation, TGF beta 1 and TGF beta 2 at 0.1-0.5 ng/ml and TGF beta 3 at 0.1-2.5 ng/ml significantly stimulated the rate of [3H]thymidine incorporation into quiescent stromal cells (P < 0.005); they were ineffective at higher concentrations. TGF beta s did not have any effect on cell proliferation, as determined by cell counting; however, at 0.1 ng/ml and higher concentrations, TGF beta s significantly reduced the metabolic activity of stromal cells, as determined by colorimetric 3-(4,5-dimethylthiazol-2-yl)2, 5-diphenyltetrazolium bromide assay (P < 0.05). The stimulatory and inhibitory actions of TGF beta s in both assays were reversible using 5-10 micrograms/ml TGF beta 1- and TGF beta 2- and 3-6 micrograms/ml TGF beta 3-specific neutralizing antibodies. TGF beta 1 at 1 ng/ml had no significant effect on long-lived protein degradation, assayed by incorporation of [14C]valine into newly synthesized protein by stromal cells, and was similar to the effect of epidermal growth factor or platelet-derived growth factor-BB (10 ng/ml). The data suggest that the TGF beta expression by various endometrial cell types in an autocrine/paracrine manner acts as a negative regulator essential for restraining endometrial growth and transition from proliferation to differentiation stages during the secretory phase after mitogenic stimulation during the proliferative phase of the menstrual cycle.


Assuntos
Endométrio/efeitos dos fármacos , RNA Mensageiro/metabolismo , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Adulto , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Endométrio/citologia , Feminino , Imunofluorescência , Humanos , Isomerismo , Proteínas/metabolismo , Células Estromais/citologia , Células Estromais/metabolismo , Timidina/metabolismo , Fator de Crescimento Transformador beta/química
18.
Arch Ophthalmol ; 110(8): 1150-4, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1386726

RESUMO

Proliferating human Tenon's capsule fibroblasts were exposed for 5 minutes to a wide range of concentrations of fluorouracil, floxuridine, and mitomycin. High concentrations of all three agents had prolonged effects on cell proliferation and morphologic characteristics compared with untreated control cells up to 36 days. The highest concentrations of both floxuridine (15,000 micrograms/mL) and mitomycin (1000 micrograms/mL) had an apparent cidal effect, reducing cell numbers below initial cell density. In contrast, although the highest concentration of fluorouracil (25,000 micrograms/mL) inhibited cell proliferation by more than 50% relative to the untreated control cells at 36 days, the cell numbers still increased fourfold compared with the initial cell density. These results demonstrate that 5-minute treatments with high concentrations of these drugs have prolonged effects on the proliferation of human Tenon's capsule fibroblasts in vitro. Single-dose regimens using high concentrations of these drugs at the time of operation may achieve results similar to those of protocols that involve repeated applications.


Assuntos
Tecido Conjuntivo/efeitos dos fármacos , Olho/efeitos dos fármacos , Floxuridina/administração & dosagem , Fluoruracila/administração & dosagem , Mitomicina/administração & dosagem , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Células do Tecido Conjuntivo , Relação Dose-Resposta a Droga , Olho/citologia , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Floxuridina/farmacologia , Fluoruracila/farmacologia , Humanos , Mitomicina/farmacologia , Concentração Osmolar , Fatores de Tempo
19.
J Abnorm Child Psychol ; 4(1): 55-8, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-1270698

RESUMO

This single case study illustrates how attention to baseline measures prevented premature conclusions regarding the impact of a conditioning procedure upon aggressive, acting-out behavior. Five disruptive behaviors were initially delineated so that frequency distributions could be obtained. During the course of this 15-day observational period, a significant reduction in the number of these aggressive responses was noted. The proposed conditioning procedure was therefore never required. Explanations as well as implications regarding the observed alteration in behavior were discussed.


Assuntos
Transtornos do Comportamento Infantil/terapia , Projetos de Pesquisa , Encenação , Agressão , Criança , Feminino , Humanos , Reforço Psicológico , Ensino , Comportamento Verbal
20.
AORN J ; 46(6): 1097-103, 1987 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3426205

RESUMO

Large defects of the chest wall can be reconstructed with healthy, well-vascularized soft tissue flaps from adjacent areas of the torso. Such treatment extends the capabilities of surgeons and operating room staff and improves the quality of life for many patients with complicated clinical problems. It requires close cooperation among surgeons, operating room staff, and consulting personnel.


Assuntos
Retalhos Cirúrgicos , Cirurgia Torácica/métodos , Feminino , Humanos , Pessoa de Meia-Idade , Planejamento de Assistência ao Paciente , Cuidados Pré-Operatórios , Cirurgia Torácica/enfermagem
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