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1.
Int J Immunopathol Pharmacol ; 25(1): 39-48, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22507316

RESUMO

ß-thujaplicin, an active constituent from Chamaecyparis obtusa, has been shown to have acaricidal and antimicrobial effects. Very few studies have focused on the potential of the anti-inflammatory effect of ß-thujaplicin. Moreover, its capability of inhibiting inflammatory mediators e.g. TNF-a gene transcription, nitric oxide (NO) and prostaglandin E2, remains unknown. Besides those molecular mechanisms behind the anti-inflammatory effect of ß-thujaplicin, solid proof of its effectiveness in vivo has not yet been studied. In our study, in vitro effects of ß thujaplicin were verified on RAW 264.7 macrophages which were stimulated by LPS. Indomethacin was used as a positive control. The inducible NO production after stimulation was measured by Griess reagent. PGE2, IL-6 and TNF-α were measured by ELISA methods. Protein expressions of iNOS, COX2, and NF-κB were evaluated by Western blotting. Septic ICR mice were administered 20 mg/kg of LPS and then the mortality rate was monitored. Within the concentration range which was devoid of cytotoxicty, ß-thujaplicin exhibited a clear dose-dependent inhibition on LPS-induced NO production. Furthermore, ß-thujaplicin inhibited LPS-induced PGE2, IL-6, and TNF-α production as well as iNOS, COX2, and NF- κB protein expression more substantially potent than indomethacin. In agreement with the in vitro study, ß-thujaplicin was shown to be effective in vivo for inhibiting LPS-induced NO and TNF-α production and a significant decrease in mortality rate of mice suffering from septic shock was observed. This study demonstrates the potential of ß-thujaplicin in treatment of inflammation and sepsis. These effects occur through an efficient blockage of TNF-α and iNOS production. ß-thujaplicin efficacy is comparable to that of indomethacin thus it can be a substitution but bear less depletion of PGE2, making this compound very promising in clinical applications. ß-thujaplicin, an active constituent from Chamaecyparis obtusa, has been shown to have acaricidal and antimicrobial effects. Very few studies have focused on the potential of the anti-inflammatory effect of ß-thujaplicin. Moreover, its capability of inhibiting inflammatory mediators e.g. TNF-alpha gene transcription, nitric oxide (NO) and prostaglandin E2, remains unknown. Besides those molecular mechanisms behind the anti-inflammatory effect of ß-thujaplicin, solid proof of its effectiveness in vivo has not yet been studied. In our study, in vitro effects of ß-thujaplicin were verified on RAW 264.7 macrophages which were stimulated by LPS. Indomethacin was used as a positive control. The inducible NO production after stimulation was measured by Griess reagent. PGE2, IL-6 and TNF-alpha were measured by ELISA methods. Protein expressions of iNOS, COX2, and NF-kB were evaluated by Western blotting. Septic ICR mice were administered 20 mg/kg of LPS and then the mortality rate was monitored. Within the concentration range which was devoid of cytotoxicty, ß-thujaplicin exhibited a clear dose-dependent inhibition on LPS-induced NO production. Furthermore, ß-thujaplicin inhibited LPS-induced PGE2, IL-6, and TNF-alpha production as well as iNOS, COX2, and NF-kB protein expression more substantially potent than indomethacin. In agreement with the in vitro study, ß-thujaplicin was shown to be effective in vivo for inhibiting LPS-induced NO and TNF-alpha production and a significant decrease in mortality rate of mice suffering from septic shock was observed. This study demonstrates the potential of ß-thujaplicin in treatment of inflammation and sepsis. These effects occur through an efficient blockage of TNF-alpha and iNOS production. ß-thujaplicin efficacy is comparable to that of indomethacin thus it can be a substitution but bear less depletion of PGE2, making this compound very promising in clinical applications.


Assuntos
Anti-Inflamatórios/uso terapêutico , Macrófagos/efeitos dos fármacos , Monoterpenos/uso terapêutico , Choque Séptico/tratamento farmacológico , Tropolona/análogos & derivados , Animais , Células Cultivadas , Dinoprostona/biossíntese , Relação Dose-Resposta a Droga , Lipopolissacarídeos/imunologia , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Monoterpenos/farmacologia , NF-kappa B/antagonistas & inibidores , Óxido Nítrico/biossíntese , Tropolona/farmacologia , Tropolona/uso terapêutico , Fator de Necrose Tumoral alfa/biossíntese
2.
Int J Immunopathol Pharmacol ; 23(3): 811-20, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20943052

RESUMO

Chlorella possesses various remarkable biological activities. One component, Val-Glu-Cys-Tyr-Gly-Pro-Asn-Arg-Pro-Gln-Phe (Chlorella-11 peptide) was found to be able to suppress LPS-induced NO production and inflammation. However, the molecular mechanism behind these findings and the consistency between in vitro and in vivo data have not been investigated. LPS-activated RAW 264.7 macrophages were used to study in vitro molecular anti-inflammatory effects of Chlorella-11 peptide. After activation, NO production and the expression of iNOS and NF-kappaB proteins as well as iNOS mRNA were measured using Griess colorimetric assay, Western blotting and RT-PCR, respectively. Alterations in PGE2 and TNF-alpha contents were also monitored by ELISA. For in vivo studies, thermal injury Wistar rats were used and inflammatory indications e.g. serum malondialdehyde (MDA), TNF-alpha levels and skin erythema were evaluated 48 h after injury implementation. In vitro results showed that Chlorella-11 peptide produced a dose- and time-dependent inhibition on NO production. The effective inhibition could remain for at least 6 h after LPS activation. It was also found that the expression of LPS-induced iNOS mRNA, iNOS and NF-kappaB proteins were diminished by the peptide treatment. Concurrently, the levels on TNF-alpha and PGE2 production after LPS activation were also inhibited. These findings are in agreement with the in vivo data that animal serum MDA and TNF-alpha levels and skin erythema in rats were considerably reduced compared to the control group (saline-treated). The significance of this study sheds light on the effectiveness of Chlorella-11 peptide in preventing inflammation progression in vitro and in vivo and its potential for clinical applications.


Assuntos
Queimaduras/patologia , Inflamação/tratamento farmacológico , Lipopolissacarídeos/antagonistas & inibidores , Ativação de Macrófagos/efeitos dos fármacos , Peptídeos/farmacologia , Animais , Western Blotting , Queimaduras/complicações , Linhagem Celular , Dinoprostona/biossíntese , Eritema/tratamento farmacológico , Eritema/patologia , Inflamação/etiologia , Lipopolissacarídeos/toxicidade , Macrófagos/efeitos dos fármacos , Masculino , Malondialdeído/metabolismo , Camundongos , NF-kappa B/biossíntese , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/biossíntese , RNA/biossíntese , RNA/isolamento & purificação , Ratos , Ratos Wistar , Fator de Necrose Tumoral alfa/sangue
3.
Opt Lett ; 27(17): 1549-51, 2002 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-18026502

RESUMO

Thin films of Bi were grown by pulsed laser deposition on glass substrates at room temperature. The thickness and roughness of the films were characterized by grazing-incidence x-ray reflectivity, and the complex refractive indices were measured in the range from 1.5 to 4 eV by spectroscopic ellipsometry. We performed Z-scan measurements to study the third-order optical nonlinearity of the films. It was found that the Bi films exhibited an unusually large nonlinear refractive coefficient, n(I)~1.24x10(-1) cm(2)/kW and nonlinear absorption coefficient, alpha(I)~-3.97 cm/W , at low laser intensity, ~60 kW/cm(2) . This anomaly is believed to have an origin related to melting of the Bi films at the focus spot by the laser beam.

4.
Alcohol Alcohol ; 36(5): 381-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11524302

RESUMO

Untreated (control) obese CBA mice had lower hormone-sensitive lipase (HSL) activity and cAMP levels in brown adipose tissue than normal lean mice, but white adipose tissue HSL activity and cAMP were similar in obese and lean mice. In the obese mice, chronic ethanol treatment increased HSL activity and cAMP levels in both brown and white adipose tissue to above the levels in lean mice. In the lean mice, chronic ethanol only stimulated white adipose tissue. UK 14304 [5-bromo-6-(2-imidazolin-2-ylamino)-quinoxaline: 2 mg/kg] inhibited HSL activity in both brown and white adipose tissues in lean mice, but a higher dose (3 mg/kg) was required to produce the same inhibition in obese mice. After chronic ethanol adipose tissues were more sensitive to UK 14304; only half the dose being required to produce the same level of lipase inhibition. We propose that, although chronic ethanol consumption increases cAMP levels in adipose tissue, particularly in obese mice, it also sensitizes the tissues to alpha(2)-adrenoceptor stimulation. These effects may explain the increased sympathetic nervous system activity observed in alcohol withdrawal.


Assuntos
Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/enzimologia , Agonistas alfa-Adrenérgicos/farmacologia , Depressores do Sistema Nervoso Central/administração & dosagem , Etanol/administração & dosagem , Obesidade/metabolismo , Quinoxalinas/farmacologia , Receptores Adrenérgicos alfa 2/metabolismo , Esterol Esterase/metabolismo , Animais , Tartarato de Brimonidina , AMP Cíclico/biossíntese , Dieta , Relação Dose-Resposta a Droga , Esquema de Medicação , Masculino , Camundongos , Camundongos Endogâmicos CBA , Obesidade/enzimologia
5.
Phys Rev Lett ; 86(11): 2281-4, 2001 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-11289909

RESUMO

Incoherent optical spatial solitons require noninstantaneous nonlinearity, i.e., the local intensity fluctuation of the solitons must be faster than the medium can respond. Observing partially incoherent bicomponent solitons, we find that there exists a threshold speed. When the fluctuation of the soliton intensity, resulting from the time-varying interference of its constituent modes, is below the threshold, the soliton beam and its induced waveguide oscillate violently. Just above the threshold, the soliton-induced waveguide is observed to be dragged by the soliton beam.

6.
Gen Pharmacol ; 34(3): 183-91, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11120380

RESUMO

Acute S 22068 (24 mg/kg po) improved glucose tolerance and increased insulin sensitivity, assessed as the acute blood glucose response to exogenous insulin. The same acute dose did not stimulate insulin secretion or induce hypoglycemia in fed animals. Comparison of acute S 22068 to equipotent doses (with respect to effect on glucose tolerance) of gliclazide (2 mg/kg) and metformin (60 mg/kg) found S 22068 to be similar to metformin with respect to its effects on basal glucose levels (BGL) and insulin sensitivity. This also suggests that S 22068 acts by a mechanism which does not involve insulin release. Acute or sub-chronic S 22068 (14 days at 25 mg/day) had no effect on brown adipose tissue (BAT) or white adipose tissue (WAT) lipogenesis, an insulin-sensitive metabolic pathway. Sub-chronic treatment with S 22068 did not alter body weight (BW) or food intake, and resulted in tolerance to its effects on glucose metabolism and insulin sensitivity. These findings suggest that S 22068 is similar in effect to metformin, and is not insulinogenic, in contrast to the sulfonylureas or putative I(3) imidazoline site ligands.


Assuntos
Glicemia/efeitos dos fármacos , Hipoglicemiantes/farmacologia , Imidazóis/farmacologia , Piperazinas/farmacologia , Animais , Feminino , Teste de Tolerância a Glucose , Hipoglicemiantes/administração & dosagem , Imidazóis/administração & dosagem , Insulina/sangue , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos , Masculino , Camundongos , Camundongos Endogâmicos CBA , Piperazinas/administração & dosagem
7.
Eur J Pharmacol ; 409(3): 223-31, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11108816

RESUMO

The time course of the effects of ethanol withdrawal on brown and white adipose tissue hormone-sensitive lipase, cAMP production, and phosphodiesterase have been investigated after chronic drinking or liquid diet schedules. Chronic drinking significantly reduced brown adipose tissue hormone-sensitive lipase activity and cAMP levels from control. During withdrawal, there was a rebound increase to 200% control, peaking 9 h into withdrawal. White adipose tissue hormone-sensitive lipase activity and cAMP accumulation were significantly raised by both treatment schedules. Ethanol liquid diet produced a significant fall in adipose tissue hormone-sensitive lipase activity and cAMP accumulation. In brown fat, there was a rebound increase in hormone-sensitive lipase activity and cAMP; in white fat, no rebound was observed. In brown fat, the reductions in hormone-sensitive lipase activity and cAMP accumulation after chronic drinking coincided with an increase in phosphodiesterase activity. In white fat, the rise in cAMP and hormone-sensitive lipase activation coincided with a decrease in phosphodiesterase activity. We conclude that the effects of chronic ethanol on hormone-sensitive lipase activity are cAMP-dependent and mediated via alterations in phosphodiesterase activity.


Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Tecido Adiposo/enzimologia , Depressores do Sistema Nervoso Central/sangue , AMP Cíclico/metabolismo , Etanol/sangue , Esterol Esterase/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Animais , Depressores do Sistema Nervoso Central/efeitos adversos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3 , Etanol/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos CBA
8.
Br J Pharmacol ; 128(7): 1586-92, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10602340

RESUMO

1. Acute SR 58611A (0.25 mg kg-1), was effective in reducing the blood glucose response to a glucose tolerance test (GTT) in normal lean (control) and spontaneously obese/diabetic CBA/Ca mice and to be equipotent to 1.25 mg kg-1 glibenclamide in lean mice. 2. Neither brown (BAT) nor white (WAT) adipose tissue lipogenesis was altered by acute SR 58611A (2 - 8 mg kg-1) in lean mice, but both increased significantly at the higher doses in the obese mice. 3. Acute SR 58611A produced a hypoglycaemia 40 min after dosing in lean and obese animals, the duration and potency of which was less than that of glibenclamide. Plasma insulin levels increased 20 min after acute SR 58611A and glibenclamide in lean and obese mice. 4. Chronic treatment (0.25 mg kg-1, 15 days) with SR 58611A increased its effectiveness in improving glucose tolerance, but did not affect the body weight (BW) or food intake of either lean or obese mice. 5. Acute and chronic SR 58611A prolonged the hypoglycaemic effect of exogenous insulin in lean but not obese mice. 6. In fed and fasted lean mice and in fasted obese mice chronic SR 58611A produced an acute hypoglycaemia 30 min post administration which was greater than after a single dose. 7. SR 58611A maintained its effectiveness in improving glucose tolerance in lean and obese mice over a dosing period of 15 days. The improvement in glucose tolerance was achieved at a dose less than that required to stimulate adipose tissue lipogenesis and which did not affect food intake or body weight.


Assuntos
Agonistas Adrenérgicos beta/farmacologia , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Receptores Adrenérgicos beta/fisiologia , Tetra-Hidronaftalenos/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Esquema de Medicação , Ingestão de Alimentos/efeitos dos fármacos , Teste de Tolerância a Glucose , Insulina/sangue , Insulina/farmacologia , Lipídeos/biossíntese , Masculino , Camundongos , Camundongos Endogâmicos CBA , Camundongos Obesos , Receptores Adrenérgicos beta 3 , Triglicerídeos/sangue
9.
Horm Metab Res ; 31(10): 580-2, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10596969

RESUMO

A method is described for measuring the acute blood glucose response to an insulin challenge which requires only 6 samples of 20 microl of blood collected over a 4 hour period. This evaluation of sensitivity to insulin was validated by comparing the effects of gliclazide, metformin and a novel antidiabetic imidazoline compound (S22068) on the blood glucose response. The test distinguished between the insulin-secreting and hypoglycaemic action of gliclazide and the insulin-sensitizing actions of metformin and S22068. The test has the advantage that it can be repeated in the same animal after a period of recovery and thus enables the overall sensitivity to insulin to be compared before and after acute or chronic dose regimes.


Assuntos
Glicemia/efeitos dos fármacos , Gliclazida/farmacologia , Insulina/sangue , Insulina/farmacologia , Metformina/farmacologia , Animais , Glicemia/metabolismo , Relação Dose-Resposta a Droga , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos CBA , Fitas Reagentes
10.
Opt Lett ; 24(7): 475-7, 1999 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18071544

RESUMO

We demonstrate a directional coupler that employs two waveguides induced by two mutually incoherent photorefractive solitons propagating in parallel at close proximity. Efficient coupling from one waveguide to the other is achieved for probe beams at wavelengths much longer than that of the solitons. We study the mutual coupling as a function of distance between solitons.

11.
Opt Lett ; 24(16): 1145-7, 1999 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18073967

RESUMO

We demonstrate experimentally second-harmonic generation in waveguides induced by photorefractive solitons and show that the conversion efficiency is improved considerably. These induced waveguides are flexible and can be generated in any crystalline direction that allows soliton formation, and thus offer broad tunability (by rotation of the crystal), which cannot exist in fabricated waveguides.

12.
Opt Lett ; 24(24): 1853-5, 1999 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-18079953

RESUMO

We predict the formation of optical spatial solitons in photorefractive polymers. The orientational enhancement from the doped chromophores and the dependency of the quantum efficiency of generating mobile holes on the electric field make the polymeric solitons behave differently from other photorefractive solitons.

13.
Psychopharmacology (Berl) ; 138(2): 143-50, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9718283

RESUMO

Diurnal variation in blood and plasma ethanol levels (BACs) has been observed in animals undergoing chronic ethanol treatment, but the information available is insufficient to determine whether the different patterns seen are due to differences in ethanol administration schedules or to strain of the animal. In this study, we have compared plasma ethanol levels in males of two mouse strains with no innate preference for ethanol, TO and CBA, during two commonly employed chronic ethanol treatment schedules. Ethanol was administered in solution as sole drink (CED) (10% or 20% w/v ethanol) for 4 weeks, or in liquid diet form (ELD), (3.5% w/v ethanol for 2 days, then 7% for 5 days). Mice were housed eight per cage on a 12-h light cycle (0900-2100 hours). Plasma ethanol concentration was monitored over the 24-h period. Activity of liver alcohol dehydrogenase (ADH) was measured between 0900 and 1100 hours. CBA mice showed greater variability in body weights than TO mice, which weighed more throughout the period of study and had significantly higher total energy intakes. TO mice consumed more ELD than CBA mice. Following an initial 2-day period of 3.5% ELD, both strains decreased their diet intake when ethanol content of the diet was increased to 7% w/v, which resulted in weight loss. Mice on the CED schedules decreased their fluid intake with increasing concentration of ethanol in the drinking solution. Highest daily ethanol intakes were observed in mice on ELD (19.1 +/- 1.7 and 22.2 +/- 0.6 g/kg body weight in CBA and TO mice, respectively). Marked diurnal variation in plasma ethanol levels was observed, which was dependent on the treatment schedule, strain and method of ethanol administration. Highest levels were found in mice on the ELD schedule (104.8 +/- 7.7 mM in CBA mice, 113.5 +/- 14.5 mM in TO mice), peaking at 1900 and at 0900 hours in CBA and TO mice, respectively. Lower plasma ethanol concentrations were reached in mice on the CED schedules, peaking at midnight (34.6 +/- 8.1 mM and 35.4 +/- 8.8 mM in CBA and TO mice on 20% CED, respectively, and 3.7 +/- 1.2 mM and 6.6 +/- 2.1 mM in CBA and TO mice on 10% CED). Naive CBA mice had slightly higher liver ADH activity as compared to their TO counterparts. No effect of 10% CED on liver ADH activity was found in either mouse strain. In conclusion, we have confirmed the importance of monitoring plasma ethanol levels during chronic treatment, as there is marked diurnal variation, dependent on the light/dark cycle. Factors such as strain of the animal and the method of delivery of ethanol are also important, whereas liver ADH plays a minor role. Monitoring the daily ethanol consumption is insufficient to predict the resulting plasma levels of the drug.


Assuntos
Alcoolismo/sangue , Ritmo Circadiano , Etanol/sangue , Álcool Desidrogenase/metabolismo , Consumo de Bebidas Alcoólicas , Alcoolismo/enzimologia , Animais , Dieta , Esquema de Medicação , Etanol/administração & dosagem , Etanol/metabolismo , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos CBA
14.
Opt Lett ; 23(12): 924-6, 1998 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-18087385

RESUMO

We show theoretically and experimentally that the photovoltaic nonlinearity that gives rise to spatial solitons can be switched from self-defocusing to self-focusing (or vice versa) by use of background illumination. This raises the possibility of bright photovoltaic solitons in LiNbO(3) .

15.
Opt Lett ; 22(7): 448-50, 1997 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-18183230

RESUMO

We present an experimental study of coherent collisions between one-dimensional bright photorefractive screening solitons in a bulk strontium barium niobate crystal.

16.
Br J Pharmacol ; 120(4): 721-7, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9051314

RESUMO

1. The effects of two chronic ethanol treatment schedules, which produce different plasma ethanol concentrations, on the specific activities of adipose tissue lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) have been investigated in brown and white fat. 2. Mice provided with 20% ethanol solution as sole drinking fluid for 28 days consumed between 13 and 15 g ethanol kg-1 body weight day-1 over days 22-28. The mean plasma ethanol concentration was 4.94 +/- 1.4 mM (n = 8) at 09 h 00 min on day 28 when the lipase assays were performed. Mice given ethanol in a liquid diet for 7 days consumed between 15 and 18 g ethanol day-1 over days 3-7. The mean plasma ethanol concentration was 15.9 +/- 4.7 mM (n = 8) at 09 h 00 min on day 7. These concentrations of ethanol had no effect on the activity of either LPL or HSL in vitro. 3. LPL activity in white and brown fat (expressed as nmol fatty acids released h-1 mg-1 acetone powder) was unaltered 60 min following an acute injection of ethanol (2.5 g kg-1, i.p.) which produced a mean blood ethanol level of 37.5 +/- 6.7 mM. HSL activity in white fat (expressed as nmol fatty acid released h-1 mg-1 protein) was also unaffected by this acute dose of ethanol, but the activity in brown fat was significantly reduced: 3.07 +/- 0.30 (n = 8) after ethanol compared to 4.36 +/- 0.25 (n = 12) in controls (P < 0.01). 4. LPL activity in white fat was little altered by either of the chronic ethanol treatment schedules whilst LPL activity in the brown fat from the same animals was significantly increased compared to the respective control values: 0.27 +/- 0.03 (ethanol drinking), control: 0.16 +/- 0.01; 0.79 +/- 0.14 (ethanol liquid diet), control: 0.39 +/- 0.05. 5. HSL activity in white fat was significantly increased by the chronic drinking treatment (7.7 +/- 0.5; control: 3.78 +/- 0.17, n = 8) at the same time that the activity in brown fat was reduced (3.76 +/- 0.2; control: 4.74 +/- 0.16). The ethanol liquid diet also reduced HSL activity in brown fat but had negligible effect in white fat. 6. The effects of the two chronic ethanol treatments on adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation in brown and white fat were very similar, both qualitatively and quantitatively, to the effects on HSL. 7. It has been shown that brown and white adipose tissues respond differently to the presence of chronic ethanol and that the response is dependent both upon the concentration of ethanol and the nature of the diet with which the ethanol is administered. The effects of ethanol on adipose tissue HSL activity appear to be mediated via changes in the tissue cyclic AMP level and, in this respect, brown fat is more sensitive to ethanol than white fat.


Assuntos
Tecido Adiposo/efeitos dos fármacos , AMP Cíclico/metabolismo , Etanol/administração & dosagem , Lipase Lipoproteica/metabolismo , Esterol Esterase/metabolismo , Tecido Adiposo/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/metabolismo , Animais , Relação Dose-Resposta a Droga , Masculino , Camundongos , Camundongos Endogâmicos CBA
17.
Opt Lett ; 22(19): 1467-9, 1997 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-18188270

RESUMO

We demonstrate self-trapping of one-dimensional and two-dimensional optical beams in a photorefractive KNbO(3) crystal. We study the waveguides induced by the self-trapped beams for prospective applications of tunable nonlinear frequency conversion in soliton-induced waveguides.

18.
Opt Lett ; 22(23): 1751-3, 1997 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18188354

RESUMO

We report the observation of steady-state photorefractive vortex-screening solitons. As a singly charged circular vortex nested on a broad beam propagates through a biased strontium barium niobate crystal, it self-traps in both transverse dimensions despite the inherent anisotropy of the photorefractive nonlinearity. When the vortex beam is a doughnut-shaped narrow beam, it breaks up into two elongated slices (with a self-defocusing nonlinearity) or into two focused filaments (with a self-focusing nonlinearity). We demonstrate the optical guidance of a probe beam in a circular waveguide induced by the self-trapped vortex.

19.
Alcohol Alcohol ; 31(1): 89-99, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8672180

RESUMO

The effects of a chronic ethanol drinking schedule (20% solution for 6 weeks) on energy balance and carbohydrate and lipid metabolism have been investigated in lean (32-36 g) and obese-diabetic (40-44 g) CBA/Ca mice. The untreated obese-diabetic mice exhibited hyperglycaemia, hypertriglyceridaemia, hyper-insulinaemia and insulin resistance. The chronic ethanol treatment, which yielded plasma ethanol levels of between 1 and 11 mM, lowered the blood glucose, plasma insulin and triacylglycerol levels towards normal in the obese mice, but did not affect these parameters in the lean mice. The body weight of the obese mice tended to return to normal during the 6-week drinking period, although their total energy intake (9.2-10.0 kJ/g/week, food plus ethanol-derived calories) was almost double that of the lean mice (4.8-5.4 kJ/g/week). The blood glucose response to acute insulin injection, which was significantly reduced in the obese mice, became indistinguishable from the response of normal mice after chronic ethanol treatment. Soleus muscle glycogen synthesis in both lean and obese mice was not significantly altered by ethanol drinking, but brown adipose tissue lipogenesis was significantly increased (by 50%) in the obese mice. It is proposed that ethanol is acting chronically to restore insulin sensitivity in the obese diabetic mice at doses which have little or no effect in normal lean animals. This action is exerted, at least in part, at the level of brown adipose tissue lipogenesis.


Assuntos
Alcoolismo/fisiopatologia , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus/fisiopatologia , Metabolismo Energético/efeitos dos fármacos , Lipídeos/sangue , Obesidade , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Marrom/fisiopatologia , Animais , Glicemia/metabolismo , Metabolismo Energético/fisiologia , Resistência à Insulina/fisiologia , Mobilização Lipídica/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos CBA , Camundongos Obesos
20.
Opt Lett ; 21(5): 324-6, 1996 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19865393

RESUMO

We study experimentally steady-state photorefractive screening solitons trapped in both transverse dimensionsand measure their beam profiles as they propagate throughout the crystal. The solitons are observed to be axially symmetric, and they self-bend. We characterize the soliton dependence on the optical intensity, appliedelectric-field strength, and beam diameter.

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