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1.
Nutr Health ; 29(3): 505-512, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35188808

RESUMO

Background: Night eating syndrome (NES) is described as a disordered eating pattern relative to sleep, where consumption of food occurs in the evening and night. Numerous studies had been conducted in various populations but studies on (NES) among call centre employees are limited. Aim: This study aimed to determine the prevalence of NES and its determinants among selected inbound call centre employees in Kuala Lumpur, Malaysia. Methods: In this cross-sectional study, a total of 217 inbound call centre employees were recruited through random sampling. A self-administered socio-demographic and work-related questionnaire was used to collect data on the background of the respondents. Information on NES and well-being was obtained by using the Night Eating Questionnaire (NEQ) and World Health Organisation-Five Well-Being Index (WHO-5) respectively. Data on dietary intakes, smoking habits, alcohol intakes and life stress were acquired using a Simple Lifestyle Indicator Questionnaire (SLIQ) while eating behaviour of the respondents was studied using the Three-Factor Eating Questionnaire (TFEQ-18). Results: The mean age of the respondents was 24.1 ± 6.0 years. The prevalence of NES was 12.0% (95% CI = 8.12-17.24). The binary logistic regression identified that NES is significantly associated with adequate exercise (AOR = 4.250, p = 0.012) and emotional eating (AOR = 6.510, p = 0.014). Conclusion: This study showed that the prevalence of NES was high in the call centre and repeated nocturnal eating can have multiple adverse health effects. Therefore, promoting healthy eating habits are crucial to reduce the impacts of NES.


Assuntos
Call Centers , Síndrome do Comer Noturno , Humanos , Adolescente , Adulto Jovem , Adulto , Síndrome do Comer Noturno/psicologia , Prevalência , Estudos Transversais , Malásia/epidemiologia , Índice de Massa Corporal , Comportamento Alimentar/psicologia , Inquéritos e Questionários
2.
J Vector Borne Dis ; 59(4): 356-362, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36751767

RESUMO

BACKGROUND & OBJECTIVES: Japanese encephalitis (JE) is a major public health problem in India. The first outbreaks of JE have been reported from the North-eastern regions of Assam, particularly from the Lakhimpur district of Assam between July-August 1989. In Assam every year many people died due to JE. This study was performed to investigate the molecular epidemiology of JE in pigs in Lakhimpur district of Assam and the risk factors associated with causing Japanese encephalitis in pigs. This study will help to map out the endemic regions and to know where and when to apply the most control strategies towards the prevention and control of the disease. METHODS: A total of 342 serum samples from pigs were collected from 10 organized and 20 unorganized farms from 9 blocks and recorded to age, sex and breed and tested by RT-PCR. Pig farms and the surrounding environment were studied for assessment of farm-level risk factors responsible for JEV infection in pigs. RESULTS: Out of 342 samples tested for detection of the E gene of JEV, 14 samples were found to be positive with a prevalence rate of 4.09%. Age, sex and breed-wise higher cases were found in at the age group above 12 months, sex wise female and breed-wise local pigs. Pig farms less than 500 meters from risk factors like rice field, stagnant water source, wild bird exposure to farm and mosquito exposure at farm/ bite to pigs, found to be more numbers of JE cases. INTERPRETATION & CONCLUSION: Molecular epidemiology of JE in pigs, and humans; positive at Lakhimpur recommend the need for uninterrupted surveillance of this virus in pigs specially those areas where pig population is more and all risk factors are present.


Assuntos
Vírus da Encefalite Japonesa (Espécie) , Encefalite Japonesa , Humanos , Suínos , Animais , Feminino , Lactente , Encefalite Japonesa/epidemiologia , Epidemiologia Molecular , Fatores de Risco , Índia/epidemiologia
3.
J Chem Phys ; 155(20): 204201, 2021 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-34852480

RESUMO

We perform two-dimensional Fourier transform spectroscopy on magneto-excitons in GaAs at magnetic fields and observe Zeeman splitting of the excitons. The Zeeman components are clearly resolved as separate peaks due to the two-dimensional nature of the spectra, leading to a more accurate measurement of the Zeeman splitting and the Landé g factors. Quantum coherent coupling between Zeeman components is observed using polarization dependent one-quantum two-dimensional spectroscopy. We use two-quantum two-dimensional spectroscopy to investigate higher four-particle correlations at high magnetic fields and reveal the role of the Zeeman splitting on the two-quantum transitions. The experimental two-dimensional spectra are simulated using the optical Bloch equations, where many-body effects are included phenomenologically.

4.
Eur J Dent Educ ; 20(4): 218-228, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26277860

RESUMO

BACKGROUND: Facebook and mobile texting are prevalent in the lives of almost every student. However, little is known about the relationship between Facebook usage or mobile texting and their impacts on health amongst undergraduate dental students. In this study, excessive Facebook use and excessive mobile texting were studied as they relate to impacts on health. MATERIALS AND METHODS: A cross-sectional study was conducted at a private university in Malaysia. A total of 188 undergraduate dental students were interviewed using a pre-tested and self-rated questionnaire. Data collected from participants were analysed using SPSS version 18.0. Chi-square test, Fisher's exact test and multiple logistic regression analyses were applied to study the relationship between explanatory variables and excessive Facebook use and excessive mobile texting. RESULTS: The prevalence of excessive Facebook use and excessive mobile texting amongst undergraduate dental students was found to be 33.2% and 33.0%, respectively. According to a multivariate analysis, texting habits, such as the presence of daytime sleepiness after texting late at night (aOR = 2.682, 95% CI = 1.142-6.301) and the presence of anxious feelings if students failed to receive a timely response (aOR = 3.819, 95% CI = 1.580-9.230), were determined to be significant predictors of excessive mobile texting. Excessive Facebook use was found to be significantly related to three variables as follows: fewer numbers of close friends (aOR = 2.275, 95% CI = 1.057-4.898), the checking of updates on the Facebook walls of their friends (aOR = 2.582, 95% CI = 1.189-5.605) and the absence of active and vigorous feelings during Facebook use (aOR = 3.401, 95% CI = 1.233-9.434). CONCLUSIONS: Approximately one-third of undergraduate dental students in this study experienced excessive Facebook use and/or excessive mobile texting. Health education and promotion should be instituted to create awareness, whilst students should be advised to practise self-control with respect to both mobile texting and Facebook usage.


Assuntos
Mídias Sociais/estatística & dados numéricos , Estudantes de Odontologia/psicologia , Estudantes de Odontologia/estatística & dados numéricos , Envio de Mensagens de Texto/estatística & dados numéricos , Adulto , Distribuição de Qui-Quadrado , Estudos Transversais , Feminino , Humanos , Malásia , Masculino , Saúde Mental , Análise de Regressão , Autocontrole/psicologia , Normas Sociais , Fatores Sociológicos , Inquéritos e Questionários , Fatores de Tempo , Universidades , Adulto Jovem
5.
J Biol Phys ; 40(3): 267-74, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24771391

RESUMO

Numerous investigations have been carried out on the spectral distribution of the light of different species of fireflies. Here we record the emission spectrum of the Indian species of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae) on a color film. Green and red color-sectors, with an intense yellow one in between, appear in this spectrum. Intensity profile of this spectrum reveals a hitherto undetected strong narrow yellow line, which lies within the full-width-at-half maximum (FWHM) of the intensity profile. The spectrum recorded in a high-resolution spectrometer confirms the presence of this sharp intense line. This finding lends support to an earlier drawn analogy between the in vivo emission of the firefly and laser light.


Assuntos
Vaga-Lumes , Medições Luminescentes , Animais , Cor , Masculino
8.
J Biosci ; 34(2): 287-92, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19550044

RESUMO

We recorded the in vivo emission and time-resolved spectra of the firefly Luciola praeusta Kiesenwetter 1874 (Coleoptera : Lampyridae : Luciolinae). The emission spectrum shows that the full width at half maximum (FWHM) value for this particular species is 55 nm, which is significantly narrower than the in vivo half-widths reported till now. The time-resolved spectrum reveals that a flash of about 100 ms duration is, in fact, composed of a number of microsecond pulses. This suggests that the speed of the enzyme-catalysed chemiluminescence reaction in the firefly for the emission of light is much faster than was previously believed.


Assuntos
Besouros/metabolismo , Luminescência , Trifosfato de Adenosina/química , Animais , Catálise , Besouros/genética , Enzimas/química , Luciferina de Vaga-Lumes/química , Luz , Modelos Genéticos , Oscilometria/métodos , Oxigênio/química , Espectrofotometria/métodos , Fatores de Tempo
9.
Indian J Exp Biol ; 47(12): 1001-5, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20329705

RESUMO

Wound healing activity of methanolic extract of leaves of Alternanthera brasiliana Kuntz was studied by excision and incision wound model (in vivo) in Sprague Dawley rats and by Chorioallantoic membrane (CAM) model (In vitro) in 9-day-old embryonated chicken eggs. In excision wound model, compared to the control group, per cent contraction of wound was significantly higher in A. brasiliana (5% w/w ointment) treated group. In incision wound model, tensile strength of the healing tissue after treatment with A. brasiliana was found to be significantly higher compared to the control group indicating better wound healing activity of the test plant. These findings were also confirmed by histopathological examination. The extract also promoted angiogenesis as evidenced by CAM model. The results suggested that methanolic extract of A. brasiliana possess significant wound healing potential in normal wound.


Assuntos
Amaranthaceae/química , Membrana Corioalantoide/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Galinhas , Membrana Corioalantoide/patologia , Metanol , Modelos Animais , Folhas de Planta/química , Ratos , Cicatrização/fisiologia
10.
Mymensingh Med J ; 18(2): 250-4, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19623156

RESUMO

FNAC has developed tremendous improvement in the diagnosis of thyroiditis. The present study was designed to asses the usefulness of FNAC to diagnose various types of thyroiditis and to study their smear patterns. Over a period of one-year, 70 cases of thyroiditis have been evaluated on the basis of cytomorphological criteria and clinical findings of patients. The age ranged from 12-60 years. Majority of the cases were between 21 to 30 years of age with female preponderance in each group of thyroiditis. Among 70 cases, 26(37.14%) cases were Hashimoto's thyroiditis, 21(30%) cases were lymphocytic thyroiditis, seven (10%) cases as granulomatous thyroiditis and 16(22.8%) were non-specific thyroiditis. Further study was carried out in these 70 cases regarding biochemical thyroid status, ultrasonography and radionucleotide scan. Blood was drawn from all patients for estimation of antibody titer to compare with cytological diagnosis. It was found that, clinical examination and history of patients had limited value in the diagnosis of thyroiditis. Ultrasonography and thyroid scan could not reliably differentiate between patients with autoimmune thyroiditis and those with simple and nodular goiter. Biochemically hypothyroidism is more frequently evaluated with Hashimoto's diseases. On the other hand, hyperthyroidism was observed in most other types of thyroiditis. Cytologically diagnosed 78.72% cases of autoimmune thyroiditis had positive antibody titer. From the present study it is concluded that FNAC is a safe, reliable, cost effective and time saving method in the diagnosis of thyroiditis. Being a benign condition also reduce the rate of unnecessary operation, which can be treated conservatively.


Assuntos
Tireoidite/patologia , Adolescente , Adulto , Biópsia por Agulha Fina , Criança , Estudos Transversais , Feminino , Doença de Hashimoto/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Tireoidite/diagnóstico , Tireoidite/imunologia , Adulto Jovem
11.
Indian J Public Health ; 52(1): 45-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18700723

RESUMO

A cross-sectional study was conducted during August 2003- July 2004 to assess the prevalence of hypertension among a tea garden population in a district of Assam and to ascertain the identified risk factors. 510 labourers aged 20-59 years were studied. Overall prevalence of hypertension was 33.3% with no significant sex difference. 30.2% had history of smoking and 76.7% of tobacco chewing; 78.4% consumed alcohol (regular and occasional), 5.7% were overweight and 14.3% underweight. Waist hip ratio was normal in 89.2% subjects. The association between increasing age and hypertension could be established in univariate analysis. On multiple logistic regression analysis regular alcohol intake was also found to be significantly associated factor with hypertension.


Assuntos
Agricultura , Hipertensão/epidemiologia , Adulto , Estudos Transversais , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência
12.
Biochim Biophys Acta ; 757(3): 288-95, 1983 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-6849977

RESUMO

All-trans retinoyl fluoride was prepared by treating all-trans retinoic acid with diethylaminosulfurtrifluoride. The crystalline product, which was characterized by melting point, infrared, 1H-NMR, 19F-NMR and elementary analysis, showed lambda max at 382 nm in hexane (epsilon = 4.98 x 10(4) M-1 . cm-1) and at 392 nm in methanol (epsilon = 4.60 x 10(4) M-1 . cm-1). Its biological activity in the rat growth assay, relative to all-trans retinyl acetate, was 22% +/- 10%. Upon oral administration for 5 days to vitamin A-depleted rats, retinoyl fluoride (1020 micrograms) was rapidly metabolized to a polar metabolite fraction and, in the intestine, to an unstable retinol-like metabolite, purportedly 15-fluororetinol. Upon administering intraperitoneally smaller doses (47-94 micrograms) of [11-3H]retinoyl fluoride, which was synthesized from [11-3H]retinoic acid, radioactive retinoic acid was noted in the liver and plasma but not in the intestine. As expected, a radioactive polar fraction appeared in the intestine and liver, but radioactive retinol, retinyl ester and some common oxidation products were not detected. Of the administered radioactivity, 72% was excreted in the urine, and only 4% was found in the feces over a 7-day period. Hydrolysis of the urine gave a radioactive fraction with a polarity similar to that of retinoic acid. Retinoyl fluoride also reacts readily with glycine to yield N-retinoyl glycine. Thus, the biological activity of retinoyl fluoride can be attributed to the formation of retinoic acid, probably by way of N-retinoyl derivatives. A possible pathway for its metabolism is presented.


Assuntos
Tretinoína/análogos & derivados , Animais , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Crescimento/efeitos dos fármacos , Absorção Intestinal , Fígado/metabolismo , Espectroscopia de Ressonância Magnética , Masculino , Ratos , Espectrofotometria Infravermelho , Estereoisomerismo , Tretinoína/síntese química , Tretinoína/metabolismo , Tretinoína/farmacologia
13.
Biochim Biophys Acta ; 799(2): 128-34, 1984 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-6547353

RESUMO

All-trans [11-3H]4,4- difluororetinyl acetate was synthesized by treating methyl all-trans [11-3H]4- oxoretinoate with diethylaminosulfurtrifluoride , followed by reduction and acetylation of the product. After oral administration of the radioactive difluoro analog in oil to rats, difluororetinol , difluororetinyl palmitate and related esters, 4- oxoretinol , 4- oxoretinoic acid and polar conjugated derivatives were identified in the intestine, liver, kidney and/or blood. The major metabolic products were difluororetinyl palmitate and related esters, which were stored in the liver. The presence of the difluoro analog in liver oil from treated rats was confirmed by 19F-NMR spectroscopy. Neither retinol nor retinyl esters were detected as products of the metabolism of the difluoro analog. Nonetheless, all-trans difluororetinyl acetate showed 26 +/- 12% of the biological activity of all-trans retinyl acetate in the rat growth assay. Presumably, the difluoro analog is active per se in growth rather than by conversion to retinol or to one of its known growth-promoting metabolites. In general, however, the difluoro analog was metabolized in a manner very similar to vitamin A. The vitamin A moiety of administered difluororetinyl acetate and retinyl acetate was poorly stored (1.8-3.3%) in the liver of vitamin A-depleted rats, confirming and extending past reports that the liver storage mechanism is severely impaired when initial liver stores are very low.


Assuntos
Fígado/metabolismo , Vitamina A/análogos & derivados , Animais , Bioensaio , Peso Corporal/efeitos dos fármacos , Diterpenos , Fezes/análise , Cinética , Espectroscopia de Ressonância Magnética , Masculino , Ratos , Ratos Endogâmicos , Ésteres de Retinil , Distribuição Tecidual , Tretinoína/análogos & derivados , Tretinoína/metabolismo , Vitamina A/metabolismo , Vitamina A/farmacologia
14.
Biochim Biophys Acta ; 1289(2): 284-90, 1996 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8600986

RESUMO

The complex of microsomal UDP-glucuronosyl transferases (UGT; EC 2.4.1.17) of rat liver catalyzes the formation of retinoyl beta-glucuronide (RAG) from retinoic acid (RA) and retinyl beta-glucuronide (ROG) from retinol (ROL) in the presence of UDP-glucuronic acid (UDPGA). The relative rates of formation of beta-glucuronides in noninduced microsomes were: 9-cis RA > 13-cis RA > all-trans 4-oxo RA > TTNPB > all-trans RA > CD-367 > 13-cis ROL > 9-cis ROL > acitretin > all-trans ROL. Michaelis constants (KM) for all-trans RA, 13-cis ROL, TTNPB and UDPGA were 130 microM, 300 microM, 210 microM and 2.6 microM, respectively. Galacturonides of RA, but not detectably of ROL, were formed from UDP-galacturonic acid at 11-30% the rate of the beta-glucuronides, whereas UDP derivatives of nonionized sugars did not serve as substrates. Pretreatment of rats with 3-methylcholanthrene markedly increased RAG formation in the absence of detergent (Triton X-100), but less so in its presence. Clofibrate pretreatment doubled the rate of RAG formation, whereas phenobarbital pretreatment showed little effect. N-Ethylmaleimide (5 microM) minimized cis-trans isomerization without significantly affecting glucuronidation. Rates of glucuronidation of retinoids clearly depend both on their isomeric states and on their chemical structures. Different UGT enzymes might well act on different geometric isomers of RA.


Assuntos
Glucuronatos/metabolismo , Glucuronosiltransferase/fisiologia , Microssomos Hepáticos/enzimologia , Retinoides/metabolismo , Animais , Indução Enzimática , Ácidos Hexurônicos/metabolismo , Masculino , Metilcolantreno/farmacologia , Ratos , Ratos Sprague-Dawley
15.
Biochim Biophys Acta ; 1502(2): 264-72, 2000 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-11040451

RESUMO

After the subcutaneous injection of retinoyl beta-glucuronide (RAG), both RAG and retinoic acid (RA), formed by the hydrolysis of RAG in vivo, achieved peak plasma concentrations within 1-2 h. Thereafter, RA was rapidly cleared from the plasma whereas RAG was eliminated much more slowly. No significant changes were noted in the peak (2 h) plasma levels of RAG for treatment periods up to 56 days (one injection of RAG/day), in the clearance rate of RAG from plasma, or in plasma retinol concentrations. Similarly, no consistent decrease in plasma levels of the RA hydrolysis product was observed. Mice undergoing these long-term chronic treatments with RAG did not show any clinical manifestations of retinoid toxicity. Taken together, our findings that chronic dosing with RAG produces sustained levels of both the parent compound and the RA hydrolysis product, combined with the apparent low toxicity of RAG, suggest that RAG could be a safe and useful alternative to some retinoids which are presently being utilized in the clinic.


Assuntos
Tretinoína/análogos & derivados , Tretinoína/farmacocinética , Animais , Feminino , Humanos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Segurança , Fatores de Tempo , Tretinoína/administração & dosagem , Tretinoína/metabolismo , Tretinoína/toxicidade , Células Tumorais Cultivadas , Vitamina A/metabolismo , Aumento de Peso/efeitos dos fármacos
16.
Trop Biomed ; 32(2): 192-7, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26691246

RESUMO

Wet mount microscopy is the most commonly used diagnostic method for trichomoniasis in clinical diagnostic services all over the world including Sri Lanka due to its availability, simplicity and is relatively inexpensive. However, Trichomonas culture and PCR are the gold standard tests. Unfortunately, neither the culture nor PCR is available for the diagnosis of trichomoniasis in Sri Lanka. Thus, it is important to validate the wet mount microscopy as it is the only available diagnostic test and has not been validated to date in Sri Lanka. The objective was to evaluate the validity and reliability of wet mount microscopy against gold standard Trichomonas culture among clinic based population of reproductive age group women in Western province, Sri Lanka. Women attending hospital and institutional based clinics were enrolled. They were interviewed and high vaginal swabs were taken for laboratory diagnosis by culture and wet mount microscopy. There were 601 participants in the age group of 15-45 years. Wet mount microscopy showed 68% sensitivity, 100% specificity, 100% positive (PPV) and 98% negative predictive values (NPV) (P=0.001, kappa=0.803) respectively against the gold standard culture. The area under the ROC curve was 0.840. Sensitivity of wet mount microscopy is low. However it has high validity and reliability as a specific diagnostic test for trichomoniasis. If it is to be used among women of reproductive age group in Western province, Sri Lanka, a culture method could be adopted as a second test to confirm the negative wet mount for symptomatic patients.


Assuntos
Testes Diagnósticos de Rotina/métodos , Técnicas Microbiológicas/métodos , Microscopia/métodos , Tricomoníase/diagnóstico , Trichomonas/isolamento & purificação , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Curva ROC , Sensibilidade e Especificidade , Sri Lanka , Trichomonas/citologia , Trichomonas/crescimento & desenvolvimento , Adulto Jovem
17.
Am J Clin Nutr ; 43(4): 481-5, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3962900

RESUMO

The occurrence of retinoyl beta-glucuronide and retinoic acid as normal endogenous components of vitamin A reserve in human blood has been demonstrated. Use of high-performance liquid chromatography, coupled with a sensitive detector and integrator, has enabled us to quantitate nanogram quantities of the two retinoids. Serum concentrations of retinoyl glucuronide and retinoic acid in all the volunteers studied ranged from 1.5 to 5.1 ng/ml (mean 2.42 ng/ml) and from 1.0 to 3.2 ng/ml (mean 1.80 ng/ml) serum, respectively. The identity of retinoyl beta-glucuronide was confirmed by its conversion to retinoic acid by the action of beta-glucuronidase and by study of the mass spectrum of the methylated derivative.


Assuntos
Tretinoína/análogos & derivados , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Tretinoína/sangue
18.
Am J Clin Nutr ; 50(2): 370-4, 1989 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2756924

RESUMO

Retinyl beta-glucuronide has been identified as a normal endogenous component of human blood, as have retinoyl beta-glucuronide and retinoic acid. The mean serum concentration of retinyl beta-glucuronide in adult volunteers (n = 6) was 6.8 +/- 4.0 nmol/L (means +/- SD) with a range from 1 to 11 nmol/L. Purified serum retinyl beta-glucuronide was characterized by the mass spectrum of its methylated trimethylsilyl derivative, by its hydrolysis by beta-glucuronidase, and by its chromatographic behavior in high-performance liquid chromatography systems. During a single day, concentrations of retinyl beta-glucuronide, retinoyl beta-glucuronide, and retinoic acid varied approximately two-fold.


Assuntos
Retinoides/isolamento & purificação , Tretinoína/análogos & derivados , Adulto , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Retinoides/sangue , Espectrofotometria Ultravioleta , Tretinoína/sangue
19.
Biochem Pharmacol ; 43(4): 919-22, 1992 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-1311592

RESUMO

Retinoid beta-glucuronides have emerged as biologically active, water-soluble, natural retinoids with relatively few toxic and teratogenic effects. The mechanism of action of these glucuronides in the control of epithelial differentiation, growth, and tumorigenesis is unknown. Since retinoyl beta-glucuronide (RAG) contains a free carboxyl group, we studied the interactions of RAG with cellular retinoic acid-binding protein (CRABP) and nuclear receptors of retinoic acid (RARs), the possible mediators of the biological action of retinoic acid (RA). RAG did not exhibit any significant affinity to bind either CRABP or RARs. During 24- and 48-hr incubations of RAG in chick cytosol, detectable amounts of RA were generated which interacted with the RA receptors. In chick skin, the biological activity of RAG may be due to this slowly released RA. Other possible modes of action of RAG are suggested.


Assuntos
Proteínas de Transporte/metabolismo , Proteínas Nucleares/metabolismo , Pele/metabolismo , Tretinoína/análogos & derivados , Animais , Ligação Competitiva , Proteínas de Transporte/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Embrião de Galinha , Citosol/metabolismo , Epitélio/metabolismo , Receptores do Ácido Retinoico , Pele/embriologia , Tretinoína/metabolismo , Tretinoína/farmacologia
20.
Nutr Rev ; 55(7): 259-67, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9279062

RESUMO

Retinoyl beta-glucuronide is a naturally occurring, biologically active metabolite of vitamin A. Although retinoyl beta-glucuronide is regarded as a detoxification product of retinoic acid, it plays several roles in the functions of vitamin A. It can serve as a source of retinoic acid, and it may be a vehicle for transport of retinoic acid to target tissues. Topically applied retinoyl beta-glucuronide is comparable in efficacy to retinoic acid in the treatment of acne in humans, without the same side effects. Retinoyl beta-glucuronide may or may not be teratogenic, depending on the mode of administration and the species in which it is used. It may be a valuable therapeutic compound for the treatment of skin disorders and certain types of cancers.


Assuntos
Tretinoína/análogos & derivados , Vitamina A/metabolismo , Anormalidades Induzidas por Medicamentos , Animais , Feminino , Absorção Intestinal , Gravidez , Tretinoína/administração & dosagem , Tretinoína/síntese química , Tretinoína/metabolismo , Tretinoína/fisiologia , Tretinoína/uso terapêutico , Tretinoína/toxicidade
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