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1.
J Phys Chem Lett ; 13(6): 1406-1415, 2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35119272

RESUMO

Two-dimensional Ruddlesden-Popper (RP) perovskites are emerging materials offering great synthetic versatility and remarkable features due to the tunability of their crystal structure. We present a novel strategy to provide magnetism in a 2D RP perovskite using histidine molecules as a spacer, which could induce charge rebalancing at the interface of the inorganic layer. We observe that the amide and imidazole groups are close to Pb ions. The interaction with the imidazole indicates that this functional group, possibly assisted by the carboxyl close to the vicinity of the amine terminal, is inducing charge rearrangement from Pb2+ to paramagnetic Pb3+ ions, resulting in a positive magnetic moment. This magnetized 2D hybrid perovskites can be classified as a novel class of promising materials showing a magnetic moment at their interface, which may result in intriguing physical properties due to a delicate balance between magnetism and a quantum well confinement effect in the inorganic layer.

2.
Eur J Clin Microbiol Infect Dis ; 31(5): 711-4, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-21814759

RESUMO

The ability to produce biofilm and the presence of metallo-ß-lactamase (MBL) among Pseudomonas aeruginosa isolates were evaluated. A total of 91 isolates were recovered from sputa of patients with (CF, n = 44) and without (non-CF, n = 47) cystic fibrosis diagnosis. Seventy-nine (86.8%; 95% CI 78.3-92.3%) were biofilm producers. Interestingly, all isolates harboring MBL showed ability (most strong or moderate) to produce biofilm in vitro. We alert to an "overlapping of mechanisms" that together represent an even greater challenge for the treatment of pulmonary infections by P. aeruginosa.


Assuntos
Biofilmes/crescimento & desenvolvimento , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Resistência beta-Lactâmica , beta-Lactamas/farmacologia , Fibrose Cística/complicações , Humanos , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/isolamento & purificação , Escarro/microbiologia
3.
Braz. j. microbiol ; 42(2): 476-479, Apr.-June 2011. graf, tab
Artigo em Inglês | LILACS | ID: lil-589993

RESUMO

Cystic fibrosis (CF) patients typically suffer of persistent and recurrent lung infections caused by Pseudomonas aeruginosa that many times possess ability for the biofilm production. Here, biofilm production among P. aeruginosa isolates recovered from sputum of CF and non-CF patients was evaluated. Most isolates were biofilm-producing independently of the patient's condition.

4.
J Endocrinol ; 209(1): 75-84, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21242228

RESUMO

Exposure to tobacco smoke is related to changes in energy balance regulation and several endocrine dysfunctions. Previously, we showed that maternal nicotine (the main addictive compound of tobacco) exposure exclusively during lactation affects biochemical profiles in mothers, milk, and pups. As the possible consequences for mothers and offspring of maternal smoking during lactation are still unknown, we evaluated the effects of tobacco smoke exposure on nutritional, biochemical, and hormonal parameters in dams and pups at weaning. After 72 h from birth, lactating rats were divided into two groups: smoke-exposed (S) in a cigarette-smoking machine, 4 × 1 h per day throughout the lactation period without pups; control (C), rats were treated the same as the experimental group but exposed to filtered air. Dams and pups were killed at weaning (21 days of lactation). Body weight and food intake were evaluated. Milk, blood, visceral fat, adrenal, and carcass were collected. S dams showed hyperprolactinemia (+50%), hypoinsulinemia (-40%), hypoleptinemia (-46%), as well as lower triglycerides (-53%) and very low-density lipoprotein cholesterol (-50%). Milk of S dams had higher lactose (+52%) and triglycerides (+78%). S pups presented higher body protein (+17%), lower total (-24%) and subcutaneous fat contents (-25%), hypoglycemia (-11%), hyperinsulinemia (+28%), hypocorticosteronemia (-40%), lower adrenal catecholamine content (-40%), hypertriglyceridemia (+34%), higher high-density lipoprotein cholesterol (+16%), and lower low-density lipoprotein cholesterol (-45%). In conclusion, tobacco smoke exposure leads to changes in nutritional, biochemical, and hormonal parameters in dams and, passively through the milk, may promote several important metabolic disorders in the progeny.


Assuntos
Composição Corporal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Lactação/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Leite/química , Poluição por Fumaça de Tabaco/efeitos adversos , Adiponectina/sangue , Análise de Variância , Animais , Animais Recém-Nascidos , Corticosterona/sangue , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Insulina/sangue , Leptina/sangue , Prolactina/sangue , Radioimunoensaio , Ratos , Ratos Wistar , Desmame
5.
Braz J Microbiol ; 42(2): 476-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24031658

RESUMO

Cystic fibrosis (CF) patients typically suffer of persistent and recurrent lung infections caused by Pseudomonas aeruginosa that many times possess ability for the biofilm production. Here, biofilm production among P. aeruginosa isolates recovered from sputum of CF and non-CF patients was evaluated. Most isolates were biofilm-producing independently of the patient's condition.

6.
Braz J Med Biol Res ; 40(1): 127-34, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17225005

RESUMO

The antinociceptive effects of a lectin (LEC) isolated from the marine alga Amansia multifida were determined in Swiss mice. The LEC (1, 5, and 10 mg/kg) inhibited acetic acid-induced abdominal writhings in a dose-dependent manner after intraperitoneal or oral administration. A partial but significant inhibition of writhings was observed after the combination of LEC (10 mg/kg) with avidin (1 mg/kg), a potent inhibitor of the hemmaglutinant activity of the lectin. However, total writhing inhibition was demonstrable in the group of mice treated with LEC plus mannose (1 mg/kg), as compared to LEC alone or to control groups. Furthermore, avidin and mainly mannose also play a role in antinociception, somehow facilitating the interaction of LEC with its active cell sites. In the formalin test, although both phases of the response were significantly inhibited, the effect of LEC was predominant during phase 2, causing inhibition of licking time that ranged from 48 to 88% after oral (5 and 10 mg/kg) and intraperitoneal (1 to 5 mg/kg) administration. As is the case with morphine, the effect of LEC (2 mg/kg) was reversed by naloxone (2 mg/kg), indicating the involvement of the opioid system. LEC was also effective in the hot-plate test, producing inhibitory responses to the thermal stimulus, and its effects were blocked by naloxone. In the pentobarbital-induced sleeping time, although LEC did not alter the onset of sleep significantly, it increased the time of sleep within the same dose range compared to control. These results show that LEC presents antinociceptive effects of both central and peripheral origin, possibly involving the participation of the opioid system.


Assuntos
Analgésicos/farmacologia , Lectinas de Plantas/farmacologia , Rodófitas/química , Analgésicos/isolamento & purificação , Animais , Feminino , Masculino , Camundongos , Medição da Dor , Extratos Vegetais/farmacologia , Lectinas de Plantas/isolamento & purificação
7.
Braz. j. med. biol. res ; 40(1): 127-134, Jan. 2007. tab
Artigo em Inglês | LILACS | ID: lil-439675

RESUMO

The antinociceptive effects of a lectin (LEC) isolated from the marine alga Amansia multifida were determined in Swiss mice. The LEC (1, 5, and 10 mg/kg) inhibited acetic acid-induced abdominal writhings in a dose-dependent manner after intraperitoneal or oral administration. A partial but significant inhibition of writhings was observed after the combination of LEC (10 mg/kg) with avidin (1 mg/kg), a potent inhibitor of the hemmaglutinant activity of the lectin. However, total writhing inhibition was demonstrable in the group of mice treated with LEC plus mannose (1 mg/kg), as compared to LEC alone or to control groups. Furthermore, avidin and mainly mannose also play a role in antinociception, somehow facilitating the interaction of LEC with its active cell sites. In the formalin test, although both phases of the response were significantly inhibited, the effect of LEC was predominant during phase 2, causing inhibition of licking time that ranged from 48 to 88 percent after oral (5 and 10 mg/kg) and intraperitoneal (1 to 5 mg/kg) administration. As is the case with morphine, the effect of LEC (2 mg/kg) was reversed by naloxone (2 mg/kg), indicating the involvement of the opioid system. LEC was also effective in the hot-plate test, producing inhibitory responses to the thermal stimulus, and its effects were blocked by naloxone. In the pentobarbital-induced sleeping time, although LEC did not alter the onset of sleep significantly, it increased the time of sleep within the same dose range compared to control. These results show that LEC presents antinociceptive effects of both central and peripheral origin, possibly involving the participation of the opioid system.


Assuntos
Animais , Masculino , Feminino , Camundongos , Rodófitas/química , Analgésicos/farmacologia , Lectinas de Plantas/farmacologia , Analgésicos/isolamento & purificação , Medição da Dor , Extratos Vegetais/farmacologia , Lectinas de Plantas/isolamento & purificação
8.
Biophys Chem ; 120(2): 154-9, 2006 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-16337076

RESUMO

In this paper, impedance measurements in the frequency range from 10(-2) to 10(6) Hz are presented for collagen and algal sulfated polysaccharide crosslinked films. We are considering the development of new biomaterials which have potential applications in coating of cardiovascular prostheses, support for cellular growth and in systems for controlled drug delivery. The effect of crosslink sulfated polysaccharide on the physical chemical properties of collagen was studied using FT-infrared spectroscopy, differential scanning calorimetry (DSC), dielectric spectroscopy. The resulting films crosslinked with glutaraldehyde (GA) in concentrations of 0.001% and 0.05% when analysed by DSC, showed that the GA treatment not only left the thermal stability of the collagen unaffected, but it also decreased the thermal transition energy. Dielectric spectroscopy shows that the effect of the crosslink on the blend film was associated to the decrease and stabilization of the dielectric permittivity at low frequencies and decreased its conductivity.


Assuntos
Colágeno/química , Reagentes de Ligações Cruzadas/farmacologia , Eucariotos/química , Glutaral/farmacologia , Polissacarídeos/química , Sulfatos/química , Materiais Biocompatíveis , Varredura Diferencial de Calorimetria , Eletroquímica , Espectroscopia de Infravermelho com Transformada de Fourier
9.
Biol Psychol ; 71(3): 278-88, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16043279

RESUMO

Two experiments examined event-related potentials (ERPs) and behavioral correlates of categorizing stimuli varying in perceptual similarity to targets. Participants performed a target-detection task in which non-target stimuli varied in target similarity but occurred with equivalent probability. The stimuli were variations of a schematic human face comprised of eight distinct features: two eyes, two eyebrows, one nose, one mouth, and two ears. Non-target stimuli that were perceptually similar to targets produced larger P300-like neurophysiological responses than did other non-target stimuli. These effects emerged whether participants' target was relatively complex (eight features) or quite simple (zero features). Accordingly, the presence of many constituent elements of a test stimulus does not appear necessary to trigger increases in categorical processing of non-targets that are similar to a target. The data further suggest that the P300 amplitude may be used as a good index of perceptual similarity between target and non-target stimuli.


Assuntos
Atenção/fisiologia , Aprendizagem por Discriminação/fisiologia , Eletroencefalografia , Potenciais Evocados P300/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Adolescente , Adulto , Nível de Alerta/fisiologia , Mapeamento Encefálico , Córtex Cerebral/fisiologia , Formação de Conceito/fisiologia , Face , Feminino , Humanos , Masculino , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia
10.
Braz J Med Biol Res ; 37(7): 1071-9, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15264015

RESUMO

Bryothamnion seaforthii, a red alga common to the Northeastern coast of Brazil, was used to prepare the protein fraction F0/60 by ammonium sulfate precipitation. The chromatography of F0/60 on DEAE-Sephadel column resulted in two lectin fractions, PI and PII, which have antinociceptive properties in rodents. We determined the antinociceptive activity of the PII fraction and of a carbohydrate-containing fraction (CF) in mice. The CF was prepared from the dried algae, after digestion with 100 mM sodium acetate, pH 6.0, containing 5 mM cysteine, EDTA and 0.4% papain, at 60 masculine C. A 10% cetylpyridinium chloride was added to the filtrate, and the precipitate was dissolved with 2 M NaCl:ethanol (100:15, v/v) followed by the carbohydrate precipitation with ethanol. The final precipitate, in acetone, was dried at 25 masculine C. The PII fraction markedly inhibited acetic acid-induced abdominal writhing after ip administration (control: 27.1 +/- 2.20; PII 0.1 mg/kg: 5.5 +/- 1.85; 1 mg/kg: 1.6 +/- 0.72 writhes/20 min) and after oral administration (control: 32.0 +/- 3.32; PII 0.1 mg/kg: 13.1 +/- 2.50; 1 mg/kg: 9.4 +/- 3.96 writhes/20 min). PII was also effective against both phases of pain induced by 1% formalin (control, ip: 48.2 +/- 2.40 and 27.7 +/- 2.56 s; PII: 1 mg/kg, ip: 34.3 +/- 5.13 and 5.6 +/- 2.14 s; control, po: 44.5 +/- 3.52 and 25.6 +/- 2.39 s; PII 5 mg/kg, po: 26.5 +/- 4.67 and 15.3 +/- 3.54 s for the 1st and 2nd phases, respectively) and in the hot-plate test. The CF (ip) also displayed significant antinociceptive properties in all tests but at higher doses (1 and 5 mg/kg, ip and po). Thus, CF at the dose of 5 mg/kg significantly inhibited writhes (ip: 7.1 +/- 2.47 and po: 14.5 +/- 2.40 writhes/20 min) as well as the 1st (po: 19.6 +/- 1.74 s) and 2nd (po: 7.1 +/- 2.24 s) phases of the formalin test compared to controls ip and po. The antinociceptive effects of both the PII and CF in the formalin and hot-plate tests were prevented at least partially by pretreatment with the opioid receptor antagonist naloxone (2 mg/kg, sc). Moreover, both fractions retained antinociceptive activity in the acetic acid-induced writhing test following heating, a procedure which abolished the hemagglutinating activity of the fraction, presumably due to lectins also present. Finally, both fractions also prolonged the barbiturate-induced sleeping time. These results indicate that carbohydrate molecules present in the PII (26.8% carbohydrate) and CF (21% of the alga dried weight) obtained from B. seaforthii display pronounced antinociceptive activity which is resistant to heat denaturation and is mediated by an opioid mechanism, as indicated by naloxone inhibition.


Assuntos
Analgésicos/farmacologia , Carboidratos/farmacologia , Eucariotos/química , Animais , Feminino , Masculino , Camundongos , Medição da Dor
11.
Braz. j. med. biol. res ; 37(7): 1071-1079, July 2004. graf
Artigo em Inglês | LILACS | ID: lil-360926

RESUMO

Bryothamnion seaforthii, a red alga common to the Northeastern coast of Brazil, was used to prepare the protein fraction F0/60 by ammonium sulfate precipitation. The chromatography of F0/60 on DEAE-Sephadel column resulted in two lectin fractions, PI and PII, which have antinociceptive properties in rodents. We determined the antinociceptive activity of the PII fraction and of a carbohydrate-containing fraction (CF) in mice. The CF was prepared from the dried algae, after digestion with 100 mM sodium acetate, pH 6.0, containing 5 mM cysteine, EDTA and 0.4 percent papain, at 60ºC. A 10 percent cetylpyridinium chloride was added to the filtrate, and the precipitate was dissolved with 2 M NaCl:ethanol (100:15, v/v) followed by the carbohydrate precipitation with ethanol. The final precipitate, in acetone, was dried at 25ºC. The PII fraction markedly inhibited acetic acid-induced abdominal writhing after ip administration (control: 27.1 ± 2.20; PII 0.1 mg/kg: 5.5 ± 1.85; 1 mg/kg: 1.6 ± 0.72 writhes/20 min) and after oral administration (control: 32.0 ± 3.32; PII 0.1 mg/kg: 13.1 ± 2.50; 1 mg/kg: 9.4 ± 3.96 writhes/20 min). PII was also effective against both phases of pain induced by 1 percent formalin (control, ip: 48.2 ± 2.40 and 27.7 ± 2.56 s; PII: 1 mg/kg, ip: 34.3 ± 5.13 and 5.6 ± 2.14 s; control, po: 44.5 ± 3.52 and 25.6 ± 2.39 s; PII 5 mg/kg, po: 26.5 ± 4.67 and 15.3 ± 3.54 s for the 1st and 2nd phases, respectively) and in the hot-plate test. The CF (ip) also displayed significant antinociceptive properties in all tests but at higher doses (1 and 5 mg/kg, ip and po). Thus, CF at the dose of 5 mg/kg significantly inhibited writhes (ip: 7.1 ± 2.47 and po: 14.5 ± 2.40 writhes/20 min) as well as the 1st (po: 19.6 ± 1.74 s) and 2nd (po: 7.1 ± 2.24 s) phases of the formalin test compared to controls ip and po. The antinociceptive effects of both the PII and CF in the formalin and hot-plate tests were prevented at least partially by pretreatment with the opioid receptor antagonist naloxone (2 mg/kg, sc). Moreover, both fractions retained antinociceptive activity in the acetic acid-induced writhing test following heating, a procedure which abolished the hemagglutinating activity of the fraction, presumably due to lectins also present. Finally, both fractions also prolonged the barbiturate-induced sleeping time...


Assuntos
Animais , Masculino , Feminino , Camundongos , Analgésicos , Carboidratos , Eucariotos , Medição da Dor , Extratos Vegetais
12.
Braz. j. med. biol. res ; 37(1): 77-82, Jan. 2004. tab
Artigo em Inglês | LILACS | ID: lil-352092

RESUMO

Typing techniques are essential for understanding hospital epidemiology, permitting the elucidation of the source of infection and routes of bacterial transmission. Although DNA-based techniques are the gold standard for the epidemiological study of Pseudomonas aeruginosa, antibiotic profiles and biochemical results are used because they are easy to perform and to interpret and relatively inexpensive. Antibiotypes (susceptibility profiles) and biotypes (biochemical profiles) were compared to genotypes established by DNA restriction enzyme analysis in 81 clinical isolates of P. aeruginosa from three hospitals in Porto Alegre, Brazil. The epidemiological relationship among patients was also evaluated. Susceptibility and restriction profiles were discrepant in more than 50 percent of the cases, and many antibiotypes were observed among isolates from the same genotype. Furthermore, susceptibility profiles did not allow the distinction of isolates from unrelated genotypes. Since a large number of isolates (63 percent) yielded the same biochemical results, only 10 biotypes were detected, showing that this typing method has a low discriminatory power. On the other hand, DNA restriction enzyme typing allowed us to establish 71 distinct types. Epidemiological data about the relation among P. aeruginosa isolates were not conclusive. The results of the present study indicate that the only method that can establish a clonal relation is DNA restriction enzyme typing, whereas the other methods may cause misleading interpretations and are inadequate to guide proper infection control measures.


Assuntos
Humanos , Técnicas de Tipagem Bacteriana , Pseudomonas aeruginosa , Brasil , Infecção Hospitalar , Enzimas de Restrição do DNA , DNA Bacteriano , Eletroforese em Gel de Campo Pulsado , Marcadores Genéticos , Genótipo , Testes de Sensibilidade Microbiana , Fenótipo , Pseudomonas aeruginosa
13.
Braz J Med Biol Res ; 37(1): 77-82, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14689047

RESUMO

Typing techniques are essential for understanding hospital epidemiology, permitting the elucidation of the source of infection and routes of bacterial transmission. Although DNA-based techniques are the "gold standard" for the epidemiological study of Pseudomonas aeruginosa, antibiotic profiles and biochemical results are used because they are easy to perform and to interpret and relatively inexpensive. Antibiotypes (susceptibility profiles) and biotypes (biochemical profiles) were compared to genotypes established by DNA restriction enzyme analysis in 81 clinical isolates of P. aeruginosa from three hospitals in Porto Alegre, Brazil. The epidemiological relationship among patients was also evaluated. Susceptibility and restriction profiles were discrepant in more than 50% of the cases, and many antibiotypes were observed among isolates from the same genotype. Furthermore, susceptibility profiles did not allow the distinction of isolates from unrelated genotypes. Since a large number of isolates (63%) yielded the same biochemical results, only 10 biotypes were detected, showing that this typing method has a low discriminatory power. On the other hand, DNA restriction enzyme typing allowed us to establish 71 distinct types. Epidemiological data about the relation among P. aeruginosa isolates were not conclusive. The results of the present study indicate that the only method that can establish a clonal relation is DNA restriction enzyme typing, whereas the other methods may cause misleading interpretations and are inadequate to guide proper infection control measures.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Pseudomonas aeruginosa/classificação , Brasil , Infecção Hospitalar/microbiologia , Enzimas de Restrição do DNA/análise , DNA Bacteriano/análise , Eletroforese em Gel de Campo Pulsado , Marcadores Genéticos , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Fenótipo , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genética
14.
Braz J Med Biol Res ; 35(6): 713-22, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12045837

RESUMO

We report the antinociceptive activity, determined by the writhing, formalin and hot-plate tests in mice, of crude (F0/60), lectin and carbohydrate fractions isolated by ammonium sulfate precipitation (0 to 60%) from Bryothamnion seaforthii and B. triquetrum, species of red algae. Not only fraction F0/60 but also lectins from both species significantly inhibited acetic acid-induced abdominal contractions after intraperitoneal or oral administrations. In the formalin test, lectins (1 and 5 mg/kg, ip, and 5 to 20 mg/kg, po) inhibited the 1st and 2nd phases (5 and 20 min, respectively), but the effect occurred predominantly on the 2nd phase. The effects of the lectins were totally or partially reversed by naloxone (2 mg/kg, sc) in the 1st and 2nd phases, respectively. Experiments performed with lectins in the absence and presence of avidin (1 mg/kg, ip) and D-mannose (1 mg/kg, ip) showed that avidin did not interfere with the effect of B. seaforthii lectin but partially reversed the effect of B. triquetrum lectin. D-Mannose completely reversed the effects of both species. F0/60 fractions from both algae significantly increased the latency time in response to thermal stimuli, and naloxone reversed antinociception, indicating the involvement of the opioid system in both the peripheral and central effects of the fractions. In the writhing test, the carbohydrate fractions were the most active, inhibiting the contractions by 71 and 79% (B. triquetrum) and by 46 and 69% (B. seaforthii) at doses of 1 and 5 mg/kg, ip, respectively. Sulfated carbohydrate fractions of B. seaforthii and B. triquetrum, containing only about 5% protein as contaminants, are probably responsible for the antinociceptive effects of these red algae.


Assuntos
Analgésicos/farmacologia , Carboidratos/farmacologia , Lectinas/farmacologia , Plantas Medicinais/química , Rodófitas/química , Analgésicos/análise , Animais , Carboidratos/análise , Bovinos , Feminino , Lectinas/análise , Masculino , Camundongos , Extratos Vegetais/farmacologia , Lectinas de Plantas , Sulfatos
15.
Braz. j. med. biol. res ; 35(6): 713-722, June 2002. ilus, tab
Artigo em Inglês | LILACS | ID: lil-309509

RESUMO

We report the antinociceptive activity, determined by the writhing, formalin and hot-plate tests in mice, of crude (F0/60), lectin and carbohydrate fractions isolated by ammonium sulfate precipitation (0 to 60 percent) from Bryothamnion seaforthii and B. triquetrum, species of red algae. Not only fraction F0/60 but also lectins from both species significantly inhibited acetic acid-induced abdominal contractions after intraperitoneal or oral administrations. In the formalin test, lectins (1 and 5 mg/kg, ip, and 5 to 20 mg/kg, po) inhibited the 1st and 2nd phases (5 and 20 min, respectively), but the effect occurred predominantly on the 2nd phase. The effects of the lectins were totally or partially reversed by naloxone (2 mg/kg, sc) in the 1st and 2nd phases, respectively. Experiments performed with lectins in the absence and presence of avidin (1 mg/kg, ip) and D-mannose (1 mg/kg, ip) showed that avidin did not interfere with the effect of B. seaforthii lectin but partially reversed the effect of B. triquetrum lectin. D-Mannose completely reversed the effects of both species. F0/60 fractions from both algae significantly increased the latency time in response to thermal stimuli, and naloxone reversed antinociception, indicating the involvement of the opioid system in both the peripheral and central effects of the fractions. In the writhing test, the carbohydrate fractions were the most active, inhibiting the contractions by 71 and 79 percent (B. triquetrum) and by 46 and 69 percent (B. seaforthii) at doses of 1 and 5 mg/kg, ip, respectively. Sulfated carbohydrate fractions of B. seaforthii and B. triquetrum, containing only about 5 percent protein as contaminants, are probably responsible for the antinociceptive effects of these red algae


Assuntos
Animais , Masculino , Camundongos , Feminino , Bovinos , Analgésicos , Carboidratos , Lectinas , Plantas Medicinais , Rodófitas , Extratos Vegetais , Sulfatos
16.
Inflamm Res ; 50(10): 486-90, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11713900

RESUMO

OBJECTIVE AND DESIGN: Since some plant and mammalian lectins specific for monosaccharides are able to induce neutrophil migration, we studied the neutrophil migration-inducing activities of marine algal lectins, specific for complex oligosaccharides from glycoproteins, from Amansia multifida (AM), Bryothamnion seaforthii (BS), Bryothamnion triquetrum (BT) and Gracilaria caudata (GC). MATERIALS AND METHODS: The neutrophil migration-inducing activity of AM, BS, BT and GC was assayed in vitro and in vivo in the peritoneal cavity or dorsal air pouch of rats or mice, and was inhibited by glycans. RESULTS: AM, BS, BT and GC induced neutrophil migration in vivo and in vitro, determining bell-shaped dose-dependent curves. Maximal neutrophil influx was determined by BT in rats and by AM in mice. Maximal human neutrophil chemotaxis was obtained with GC. These activities were not inhibited by glycoproteins previously identified as being recognized by these lectins. D-mannose was a strong inhibitor, especially of BT activity both in vitro and in vivo. CONCLUSIONS: Algal lectins induced neutrophil migration, which was inhibited by a monosaccharide, contrasting with the view that they only recognize complex oligosaccharides. Neutrophil chemotaxis assays are appropriate to study low molecular mass lectins containing a single carbohydrate recognition domain, as is the case of some lectins from algae and mammals.


Assuntos
Quimiotaxia de Leucócito/efeitos dos fármacos , Lectinas/farmacologia , Neutrófilos/efeitos dos fármacos , Rodófitas/química , Animais , Glicoproteínas/farmacologia , Lectinas/antagonistas & inibidores , Lectinas/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Monossacarídeos/farmacologia , Cavidade Peritoneal/citologia , Ratos , Ratos Wistar
17.
J Pers Soc Psychol ; 80(3): 410-24, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11300575

RESUMO

Assuming that people often hold the abstract goal of acquiring accurate feedback but recognize that acquiring favorable feedback can make the self-evaluative process more comfortable, the authors posited that low-level construals (of how action is performed) would elicit greater self-enhancement motivation than would high-level construals (of why action is performed). Individuals chronically using low-level construals had greater interest in downward social comparison (DSC) and less interest in negative feedback (NF; Studies 1 and 3). Decreases in temporal distance (which foster low-level construals) also elicited greater interest in DSC and less interest in NF (Studies 2 and 4). The latter effect was explained by participants' aversion to inconvenience (Study 5) and not by approach-avoidance conflict (Study 6). These results suggest that the level of abstraction at which people construe self-evaluative situations can influence their feedback preferences.


Assuntos
Objetivos , Relações Interpessoais , Autoimagem , Percepção Social , Adolescente , Adulto , Análise de Variância , Connecticut , Feminino , Humanos , Masculino , Modelos Psicológicos , New York , Comportamento Social
18.
Child Dev ; 69(4): 1074-91, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9768487

RESUMO

Some children respond to social rejection in ways that undermine their relationships, whereas others respond with more equanimity. This article reports 3 studies that test the proposition that rejection sensitivity--the disposition to defensively (i.e., anxiously or angrily) expect, readily perceive, and overreact to social rejection--helps explain individual differences in response to social rejection. Data were from urban, minority (primarily Hispanic and African American) fifth to seventh graders. Study 1 describes the development of a measure of rejection sensitivity for children. Study 2 provides experimental evidence that children who angrily expected rejection showed heightened distress following an ambiguously intentioned rejection by a peer. Study 3 shows that rejection sensitive children behaved more aggressively and experienced increased interpersonal difficulties and declines in academic functioning over time.


Assuntos
Comportamento do Adolescente , Ira , Relações Interpessoais , Rejeição em Psicologia , Ajustamento Social , Adolescente , Agressão , Ansiedade/etiologia , Criança , Estudos Transversais , Emoções Manifestas , Feminino , Humanos , Estudos Longitudinais , Masculino , Técnicas Projetivas , Psicometria/métodos , Psicometria/normas , Valores de Referência , Reprodutibilidade dos Testes , Autoavaliação (Psicologia) , Percepção Social , Estatística como Assunto , Inquéritos e Questionários/normas , Saúde da População Urbana
19.
J Pers Soc Psychol ; 75(2): 545-60, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9731324

RESUMO

The authors hypothesized a self-fulfilling prophecy wherein rejection expectancies lead people to behave in ways that elicit rejection from their dating partners. The hypothesis was tested in 2 studies of conflict in couples: (a) a longitudinal field study where couples provided daily-diary reports and (b) a lab study involving behavioral observations. Results from the field study showed that high rejection-sensitive (HRS) people's relationships were more likely to break up than those of low rejection-sensitive (LRS) people. Conflict processes that contribute to relationship erosion were revealed for HRS women but not for HRS men. Following naturally occurring relationship conflicts, HRS women's partners were more rejecting than were LRS women's partners. The lab study showed that HRS women's negative behavior during conflictual discussions helped explain their partners' more rejecting postconflict responses.


Assuntos
Cognição , Relações Interpessoais , Amor , Rejeição em Psicologia , Adulto , Conflito Psicológico , Feminino , Seguimentos , Humanos , Masculino , Inquéritos e Questionários
20.
Arq Gastroenterol ; 34(4): 217-21, 1997.
Artigo em Português | MEDLINE | ID: mdl-9629315

RESUMO

The idiopathic dysfunction of the cricopharyngeal muscle is a rare disease. Limited understanding of the pharyngoesophageal physiology and physiopathology make the management of this disease complex. We have studied three patients with idiopathic crycopharyngeal dysfunction submitted to cricomyotomy. One patient did not present improvement after surgery. The authors discuss the difficulties in making the diagnosis., the treatment and the selection of patients who will benefit from this surgical procedure.


Assuntos
Transtornos de Deglutição/fisiopatologia , Músculos Faríngeos/fisiopatologia , Adulto , Transtornos de Deglutição/diagnóstico por imagem , Transtornos de Deglutição/cirurgia , Feminino , Humanos , Masculino , Manometria , Pessoa de Meia-Idade , Músculos Faríngeos/diagnóstico por imagem , Músculos Faríngeos/cirurgia , Radiografia , Estudos Retrospectivos
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