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1.
Braz J Med Biol Res ; 54(4): e10346, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33624730

RESUMO

The main movements of artistic swimming demand various physical capacities such as flexibility, strength, power, and muscular endurance. The use of ergogenic resources to potentialize performance in this sport, however, is underexplored and deserves investigation. In the present study, we tested whether caffeine ingestion would improve the execution of movements that are essential in a typical figure competition or routines in artistic swimming (i.e., amplitude in the Ariana, height in the Boost and Barracuda, and time maintained in the Stationary Scull techniques). Sixteen experienced female athlete artistic swimmers (17.4±3.2 years of age, 5.6±2.8 years of artistic swimming practice) performed several movements of artistic swimming after having ingested a capsule containing caffeine (5 mg/kg body mass) or cellulose (placebo). Compared to the placebo, caffeine improved latero-lateral amplitude during the Ariana (P=0.035), the height of the Boost and Barracuda (P=0.028 and 0.009), and maintained duration in Stationary Sculling (P=0.012). Bayes factor analysis, however, indicated substantial evidence of a positive effect of caffeine only on the Barracuda and Stationary Scull techniques. These findings indicated that caffeine improved performance during specific artistic swimming movements. Coaches and athletes should consider caffeine ingestion in their supplementation plans.


Assuntos
Desempenho Atlético , Cafeína , Teorema de Bayes , Cafeína/farmacologia , Criança , Pré-Escolar , Ingestão de Alimentos , Feminino , Humanos , Natação
2.
Ticks Tick Borne Dis ; 7(5): 782-787, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27020736

RESUMO

Human granulocytic anaplasmosis (HGA) is an emerging tick-borne zoonosis worldwide. As is the case for many tick-borne diseases, the epidemiological cycle is associated to the environmental conditions, including the presence of wild vertebrate reservoir hosts, vectors, climate and vegetation. In this study a total number of 87 spleen samples of wild ruminants carcasses from Central Italy, and 77 Ixodes ricinus collected from the same dead animals were screened for Anaplasma phagocytophilum by using Real Time PCR. A. phagocytophilum DNA was detected in 75%, 66.7% and 54.2% of the spleen samples from red deer (Cervus elaphus), Apennine chamois (Rupicapra pyrenaica ornata) and roe deer (Capreolus capreolus) respectively, whereas it was detected in the 31.2% of I. ricinus. A total of 27 positive samples were characterized by sequencing a portion of the groEL gene. Two A. phagocytophilum lineages could clearly be delineated from the phylogenetic tree. Four sequences from red deer, 2 from I. ricinus and 1 from Apennine chamois clustered into lineage I together with those previously described as virulent genotypes related to HGA. The presence of A. phagocytophilum DNA in the Apennine chamois represents the first report for this Italian endemic subspecies.


Assuntos
Anaplasma phagocytophilum/genética , Anaplasma phagocytophilum/patogenicidade , Anaplasmose/microbiologia , Cervos/microbiologia , Reservatórios de Doenças , Ehrlichiose/microbiologia , Ixodes/microbiologia , Anaplasmose/epidemiologia , Animais , Animais Selvagens/microbiologia , Chaperonina 60/genética , Ehrlichiose/epidemiologia , Ehrlichiose/veterinária , Genótipo , Humanos , Itália/epidemiologia , Filogenia , Rupicapra/microbiologia , Baço/microbiologia , Zoonoses
3.
Vet Ital ; 42(2): 103-18, 2006.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-20429055

RESUMO

During the recent severe outbreaks of bluetongue (BT) in the Mediterranean Basin, the BT virus (BTV) spread beyond its historical limits into the Balkan region. One of the primary impacts of BT is the cessation in livestock trade which can have severe economic and social consequences. The authors briefly describe the development of the collaborative East-BTnet programme which aims to assist all affected and at-risk Balkan states and adjoining countries in the management of BT, and in the development of individual national surveillance systems. The beneficiary countries involved, and led by the World organisation for animal health (Office International des Epizooties) Collaborating Centre for veterinary training, epidemiology, food safety and animal welfare of the Istituto Zooprofilattico dell'Abruzzo e del Molise 'G. Caporale' in collaboration with the Institute for the Protection and the Security of the Citizen, the European Commission Joint Research Centre (IPSC-JRC), were Albania, Bosnia-Herzegovina, Bulgaria, Croatia, Cyprus, the Former Yugoslavia Republic of Macedonia, Kosovo, Malta, Romania, Serbia and Montenegro, Slovenia and Turkey. A regional web-based surveillance network is a valuable tool for controlling and managing transboundary animal diseases such as BT. Its implementation in the Balkan region and in adjoining areas of south-eastern Europe is described and discussed.

4.
Vet Ital ; 42(3): 201-7, 193-9, 2006.
Artigo em Inglês, Italiano | MEDLINE | ID: mdl-20429060

RESUMO

Bluetongue (BT) is an infectious, non-contagious, arthropod-borne disease transmitted by biting midges. When BT spread throughout the Balkans (affecting Albania, Bosnia-Herzegovina, Bulgaria, Croatia, the Former Yugoslav Republic of Macedonia and Serbia and Montenegro), it caused serious concerns for veterinary authorities in all countries in the eastern Mediterranean. In 2003-2004 a web-based BT geographic information system network was developed and implemented to provide veterinary services with a tool to manage and analyse data on the disease and to exchange information. The system was centralised to ensure there was a common epidemiological surveillance strategy. Spatial and alphanumerical data on the disease were organised in a single relational geographic database. The system was equipped with a number of applications for the display of dynamic maps and data information via the web, with multi-user access for simultaneous queries from additional users.

5.
Rev Sci Tech ; 24(3): 857-68, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16642756

RESUMO

Since 2000 Italy has experienced five epidemics of bluetongue, an arthropod-borne disease that affects primarily sheep and asymptomatically cattle, goats and wildlife ruminants. In four years the disease spread through Southern and Central Italy, involving 14 Italian regions out of 20. To control the disease, the Ministry of Health established a surveillance system that included clinical, entomological and serological surveillance elements. The National Reference Centre for Veterinary Epidemiology--Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise 'G. Caporale'--developed a Web-based National Information System (NIS) and a Geographical Information System (GIS)to collect and manage data from Veterinary Services across Italy. The system was designed to gather and spread information in order to support the management of control activities and to provide an early warning system. Surveillance data are displayed to the user in different ways: reports, tables and interactive maps.


Assuntos
Bluetongue/epidemiologia , Doenças dos Bovinos/epidemiologia , Sistemas de Informação Geográfica , Doenças das Cabras/epidemiologia , Animais , Animais Domésticos , Animais Selvagens , Bovinos , Surtos de Doenças/veterinária , Cabras , Internet , Itália/epidemiologia , Vigilância de Evento Sentinela/veterinária , Ovinos
6.
Vet Ital ; 40(3): 133-6, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-20419650

RESUMO

At present, Switzerland is considered officially free from bluetongue (BT) disease. Recently reported outbreaks have recorded BT moving north as far as latitude 44 degrees 30'N in Europe and 49 degrees N in Kazakhstan. The absence of clinical disease does not prove freedom from BT virus (BTV) infection. In addition, the occurrence and distribution of the only known biological vector, certain species of Culicoides biting midges (Diptera: Ceratopogonidae), is poorly understood for Switzerland. Consequently the Swiss Veterinary Office initiated a project on BT surveillance in April 2003 on cattle farms. The study comprised serological and entomological activities; initial results are presented.

7.
Toxicol In Vitro ; 16(6): 683-93, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12423651

RESUMO

A representative set of potent antibacterial 6-desfluoro-8-methylquinolones, in which the C-6 fluorine atom is replaced by -NH(2) or -H, and their 6-fluoro counterparts, were investigated to evaluate their phototoxic potential and to explore the mechanism behind their phototoxicity. The capacity to photosensitize biological substrates (lipids, proteins, DNA) has been analyzed, as well as their photocytotoxicity on red blood cells and 3T3 murine fibroblasts. The results obtained show that the quinolones studied are able to photosensitize red blood cell lysis in an oxygen-dependent way and induce a high decrease in cell viability after UVA irradiation. A major correlation with phototoxicity lies in the structure of the individual antibacterials and their hydrophobicity; in particular, 6-amino derivatives are less phototoxic than corresponding unsubstituted and fluorinated compounds. Cellular phototoxicity was inhibited by the addition of free radical and hydroxyl radical scavengers (BHA, GSH and DMTU), suggesting the involvement of a radical mechanism in their cytotoxicity. A good correlation was observed between lipid peroxidation and phototoxicity, indicating that the test compounds exert their toxic effects mainly in the cellular membrane. Preliminary experiments on pBR322 DNA show that these derivatives do not photocleave DNA, differently from the two photogenotoxic fluoroquinolones, ciprofloxacin and lomefloxacin, used as reference compounds.


Assuntos
Dano ao DNA , Compostos de Flúor/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Quinolonas/efeitos adversos , Quinolonas/farmacologia , Animais , Dermatite Fototóxica/fisiopatologia , Eritrócitos , Fibroblastos , Luz , Metabolismo dos Lipídeos , Peroxidação de Lipídeos , Camundongos , Fotoquímica , Proteínas/metabolismo
8.
Farmaco ; 55(3): 211-8, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10919085

RESUMO

Amitriptyline and imipramine, two tricyclic antidepressant drugs, have been studied to evaluate their phototoxic potential using various models. Reactive oxygen species production was investigated. A negligible production of singlet oxygen was observed for both compounds whereas a significant production of superoxide anion was noted for amitriptyline in particular. Moderate red blood cell lysis under UVA light (365 nm) was induced in the presence of the two drugs at a concentration of 50 microM. Cellular phototoxicity was investigated on a murine fibroblast cell line (3T3). The two drugs were phototoxic causing cell death at a concentration of 100 microM and a UVA dose in the range of 3.3-6.6 J/cm2. Furthermore, the two drugs photosensitized the peroxidation of linoleic acid, as monitored by the formation of dienic hydroperoxides. The presence of BHA and GSH, two free radical scavengers, significantly reduced the lipid oxidation photoinduced by the drugs, suggesting a predominant involvement of radical species. Finally, the involvement of nucleic acids in the phototoxicity mechanism was also investigated using a pBR322 plasmid DNA as a model.


Assuntos
Amitriptilina/toxicidade , Antidepressivos Tricíclicos/toxicidade , Dermatite Fototóxica/etiologia , Imipramina/toxicidade , Amitriptilina/química , Animais , Antidepressivos Tricíclicos/química , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Corantes , DNA/efeitos dos fármacos , DNA/efeitos da radiação , Dano ao DNA , Dermatite Fototóxica/patologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/efeitos da radiação , Fibroblastos , Hemólise/efeitos dos fármacos , Hemólise/efeitos da radiação , Imipramina/química , Ácido Linoleico/química , Peroxidação de Lipídeos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Fotoquímica , Espécies Reativas de Oxigênio , Sais de Tetrazólio , Tiazóis , Raios Ultravioleta
9.
Photochem Photobiol ; 72(1): 23-7, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10911725

RESUMO

The crystal structures of 4,6-dimethyltetrahydrobenzoangelicin (THBA), a furocoumarin analog, and of its furan-side cis-syn cycloadduct with thymine formed in the photoreaction with DNA, have been determined. The crystal structure of the latter compound contained only one enantiomeric form corresponding to the addition to a 5'-XpT site. Contrary to most psoralen derivatives studied, THBA showed higher photoreactivity toward synthetic oligonucleotides containing that sequence than toward those with the 5'-TpX sequence.


Assuntos
DNA/química , DNA/efeitos da radiação , Furocumarinas/química , Furocumarinas/efeitos da radiação , Sequência de Bases , Sítios de Ligação , Técnicas In Vitro , Oligodesoxirribonucleotídeos/química , Oligodesoxirribonucleotídeos/efeitos da radiação , Fotoquímica , Timina/química , Timina/efeitos da radiação
10.
Photochem Photobiol ; 71(5): 506-13, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10818780

RESUMO

The decay processes of the lowest excited singlet and triplet states of five heteropsoralens (HPS) were investigated by steady-state and shift-phase fluorometry and by laser-flash photolysis in different solvents. The emission spectra of HPS are detectable only in trifluoroethanol (TFE), where fluorescence lifetimes (tau F) and quantum yields (phi F) were measured. The triplet lifetimes (tau T), triplet (phi T) and singlet-oxygen production (phi delta) quantum yields were determined in benzene, ethanol and TFE by laser-flash photolysis. Semiempirical (INDO/1-CI) calculations allowed the nature of the lowest excited singlet and triplet states and transition probabilities to be obtained. Theoretical and experimental results indicate that the two lowest excited singlet states S1 and S2 of HPS are close-lying and different in nature (pi,pi* and n,pi*). The "proximity effect" between these two states controls the photophysical properties of HPS as it does for the other furocoumarins. However, HPS have a peculiar behavior with respect to the related compounds because they are fluorescent and have, in three cases, detectable intersystem crossing only in TFE. This behavior can be tentatively explained by a different energy gap and/or order between the S1 and S2 states.

11.
Farmaco ; 55(8): 515-20, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11132728

RESUMO

Photochemotherapy using psoralens and UVA is a treatment used widely in some skin diseases, in cutaneous lymphomas and in autoimmune diseases. This review has selected recent publications dealing with the photochemical processes triggered in the cells by UVA radiation and psoralen treatment. The photochemical changes initiated in the cell membranes were described.


Assuntos
Furocumarinas/uso terapêutico , Terapia PUVA , Membrana Celular/efeitos dos fármacos , Membrana Celular/efeitos da radiação , Furocumarinas/farmacologia
12.
Farmaco ; 54(8): 551-61, 1999 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-10510852

RESUMO

Three derivatives of 1H,5H and 3H,5H-benzo[ij]quinolizin-5-one (BQZ1), previously prepared by chemical synthesis with the aim of obtaining furocoumarin analogs, have been studied. These are able to intercalate inside DNA and by subsequent irradiation with UVA light, to photoreact with DNA. Compound I (10-methoxy-7-methyl-1H,5H-benzo[ij]quinolizin-5-one) has a potentially photoreactive 2,3 double bond because of its conjugation with the pyridine ring of quinolinone, while compounds II (10-acetoxy-7-methyl-3H,5H-benzo[ij]quinolizin-5-one) and III (10-methoxy-7-methyl-3H,5H-benzo[ij]quinolizin-5-one) have a potentially photoreactive 1,2 double bond conjugated with the benzene ring of quinolinone. Compounds I and III, having a tricyclic planar structure, intercalate inside the DNA, while compound II cannot intercalate efficiently because of the steric hindrance of the acetoxy group in 10, lying outside the plane of the molecule and rotated by an angle of 77.6 degrees with respect to the tricyclic plane. The photoreaction of BQZ with DNA structure, as already known for psoralen and angelicin derivatives, consists of a [2 + 2] photocycloaddition reaction with the pyrimidine bases. The main photoadduct between the 2,3 double bond of I and the 5,6 double bond of thymine has been isolated and characterized by NMR, showing a cis-anti structure. Theoretical calculations, using AM1 Hamiltonian, have been carried out to describe the photocycloaddition reaction mechanism better. From a theoretical point of view, in the case of BQZ both the 1,2 or 2,3 double bonds and the 6,7 double bond may be involved in the [2 + 2] photocycloaddition. Spin densities and molecular orbital symmetries of compound I, in its triplet state, suggest that the 2,3 double bond interacts favorably with the 5,6 double bond of thymine moiety. On the contrary, the acetoxy substituent in position 10 of II seems to play a negative role in the DNA intercalation process.


Assuntos
Cumarínicos/síntese química , DNA/efeitos dos fármacos , Substâncias Intercalantes/síntese química , Quinolizinas/síntese química , Dicroísmo Circular , Cumarínicos/farmacologia , Reagentes de Ligações Cruzadas , DNA/efeitos da radiação , Adutos de DNA/efeitos dos fármacos , Adutos de DNA/efeitos da radiação , Fluorometria , Substâncias Intercalantes/farmacologia , Cinética , Modelos Moleculares , Teoria Quântica , Quinolizinas/farmacologia , Raios Ultravioleta
13.
Farmaco ; 54(3): 134-44, 1999 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-10371025

RESUMO

4,4',5'-Trimethyl-1'-thioangelicin (1) and 4,6,4',5'-tetramethyl-1'-thioangelicin (2), two newly synthesised isosters of furocoumarins having a sulfur atom in their five-membered ring, were studied in terms of interactions with DNA, both in the ground state and after UVA light absorption. The compounds were able to intercalate the macromolecule and to photobind efficiently, forming C4-cycloadducts with thymine. The antiproliferative effect of this binding was shown in Ehrlich and HeLa cells and by T2 phage inactivation. Tests on Salmonella typhimurium indicated low mutagenic activity. In particular, compound 1 has photobiological activity comparable with that of 4,6,4'-trimethylangelicin, but is less mutagenic.


Assuntos
Cumarínicos/farmacologia , Furocumarinas/farmacologia , Mutagênicos/farmacologia , Fármacos Fotossensibilizantes/farmacologia , Tiofenos/farmacologia , Divisão Celular/efeitos dos fármacos , Divisão Celular/efeitos da radiação , Cumarínicos/síntese química , Cumarínicos/efeitos da radiação , Reagentes de Ligações Cruzadas , DNA/efeitos dos fármacos , Adutos de DNA , Furocumarinas/síntese química , Furocumarinas/efeitos da radiação , Células HeLa , Humanos , Espectrometria de Massas , Estrutura Molecular , Mutagênese/efeitos dos fármacos , Mutagênese/efeitos da radiação , Mutagênicos/síntese química , Mutagênicos/efeitos da radiação , Myoviridae/efeitos dos fármacos , Myoviridae/genética , Myoviridae/efeitos da radiação , Fotobiologia , Fotoquímica , Fotólise , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/efeitos da radiação , Espécies Reativas de Oxigênio , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Salmonella typhimurium/efeitos da radiação , Tiofenos/síntese química , Tiofenos/efeitos da radiação
14.
J Photochem Photobiol B ; 45(2-3): 122-30, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9868802

RESUMO

The formation of cyclobutane (cb) photoadducts of psoralen with a model lecithin has been shown. The adducts are formed both in ethanol solution and in micellar suspension in water. In spite of their sensitivity to various factors such as light, temperature, air, etc., they are isolated by thin-layer chromatography (TLC) and high-pressure liquid chromatography (HPLC) and characterized by mass spectrometry, NMR and UV absorption spectroscopy. The NMR analysis indicates the similarity of isomeric forms of cb adducts in lecithin to those formed with free oleic acid.


Assuntos
Ficusina/metabolismo , Fosfatidilcolinas/metabolismo , Fármacos Fotossensibilizantes/metabolismo , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectrofotometria Ultravioleta
15.
Chem Res Toxicol ; 11(9): 1089-97, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9760284

RESUMO

The photolysis of the water-soluble perester 1 leads to tert-butoxyl radicals as confirmed by EPR studies with the spin trap 5, 5-dimethylpyrroline N-oxide (DMPO). In the presence of DNA, oxidative cleavage of the latter was demonstrated by the formation of strand breaks in supercoiled pBR 322 DNA and by a substantial decrease of the melting temperature of salmon testes DNA. Guanidine, released from, for example, oxazolone and oxoimidazolidine on base treatment, was observed with calf thymus DNA and 2'-deoxyguanosine. These DNA modifications were effectively inhibited by the radical scavenger di-tert-butylcresol or the hydrogen atom donor glutathione. Photosensitization by the arene chromophore was excluded since the corresponding ester 2 caused no DNA damage, nor were the photoproducts of the perester 1 active. The efficacy of the perester 1 in oxidizing DNA derives from the fact that the tert-butoxyl radicals are photolytically generated in the immediate vicinity of the DNA, due to electrostatic binding of the cationic perester to the DNA, as confirmed by fluorescence measurements. These results demonstrate that the photolysis of perester 1 provides a suitable source of tert-butoxyl radicals in aqueous media, a necessary prerequisite for biochemical investigations.


Assuntos
Dano ao DNA , DNA/efeitos dos fármacos , DNA/metabolismo , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/toxicidade , Animais , Bovinos , Fenômenos Químicos , Físico-Química , DNA/química , DNA Super-Helicoidal/química , DNA Super-Helicoidal/metabolismo , Radicais Livres/química , Guanina/química , Guanina/metabolismo , Oxirredução , Fotólise , Compostos de Amônio Quaternário/síntese química
16.
Photochem Photobiol ; 68(4): 511-8, 1998 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-9796433

RESUMO

We describe the synthesis of a novel psoralen peroxide 1 that generates on irradiation (350 nm) alkoxyl radicals, namely tert-butoxyl radicals, as confirmed by electron spin resonance studies with the spin trap 5,5-dimethyl-pyrroline-N-oxide. The radical source intercalates into the DNA, which has been demonstrated by linear-flow-dichroism measurements. Thus, the alkoxyl radicals are formed advantageously directly in the DNA matrix. In supercoiled pBR322 DNA, the generation of strand breaks by the photochemically or metal-catalyzed generated alkoxyl radicals is demonstrated. Photosensitization by the psoralen chromophore was excluded because similar substances that do not release radicals caused no DNA damage, nor were the photoproducts of the peroxide 1 active. With calf thymus DNA, 8-oxoGua and small amounts of guanidine-releasing products, e.g. oxazolone, were observed. However, in these reactions the photoproduct also displayed some DNA-oxidizing capacity.


Assuntos
Dano ao DNA , DNA Super-Helicoidal/efeitos da radiação , Substâncias Intercalantes/química , Metoxaleno/análogos & derivados , Plasmídeos/efeitos da radiação , Raios Ultravioleta , Óxidos N-Cíclicos , DNA Super-Helicoidal/química , DNA Super-Helicoidal/efeitos dos fármacos , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Substâncias Intercalantes/farmacologia , Metoxaleno/síntese química , Metoxaleno/química , Metoxaleno/farmacologia , Desnaturação de Ácido Nucleico , Fotólise , Plasmídeos/química , Plasmídeos/efeitos dos fármacos , Marcadores de Spin
17.
J Photochem Photobiol B ; 44(1): 39-44, 1998 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9745727

RESUMO

By UVA irradiation of an ethanol solution of psoralen and oleic acid, four main photoproducts have been isolated and characterized: two have cis,cis structure; the other two are trans,cis. The same adducts have been isolated from the photoreaction of psoralen with beta-oleoyl-gamma-stearoyl-1-alpha-phosphatidylcholine followed by enzymatic hydrolysis with phospholipase A2. The four isomers stimulate protein kinase C to almost the same extent.


Assuntos
Ficusina/efeitos da radiação , Ácido Oleico/efeitos da radiação , Proteína Quinase C/sangue , Raios Ultravioleta , Plaquetas/enzimologia , Humanos , Isomerismo , Conformação Molecular , Estrutura Molecular , Fosfolipases A/metabolismo , Fosfolipases A2 , Estereoisomerismo
18.
J Photochem Photobiol B ; 42(3): 167-79, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9595706

RESUMO

Exposure to UV light has, besides some beneficial effects (vitamin D production), many harmful effects on human health. UVB irradiation has been shown to suppress both systemic and local immune responses to a variety of antigens, including some microorganisms. However, it is still not known whether such immunomodulating effects may lead to an increase in the number and severity of certain tumours and/or infections in humans. We report herein the data provided by a project that was funded by the European Union (Programme Environment), and that was aimed at the estimation of the risk associated with increased UVB exposure due to ozone depletion regarding the deleterious effects on the immune system and related resistance to tumours and infections in humans. The data, obtained by the different research groups involved, were assembled and used to calculate for the first time a risk assessment for increased environmental exposure to UVB in human subjects.


Assuntos
Doenças Transmissíveis/imunologia , Sistema Imunitário/imunologia , Sistema Imunitário/efeitos da radiação , Neoplasias/imunologia , Raios Ultravioleta , Animais , Humanos , Imunidade Inata/efeitos da radiação , Terapia de Imunossupressão , Fatores de Risco , Pele/efeitos da radiação , Neoplasias Cutâneas/etiologia
19.
Farmaco ; 52(11): 645-52, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9550088

RESUMO

1-Thiopsoralen (7H-thieno[3,2-g]benzofuran-7-one) 1, a lead compound of a series of heteropsoralens, was investigated. The electronic transitions involved were studied. Fluorescence quantum yield is very low, while laser flash photolysis showed that the triplet state is practically the sole transient of 1. Fluorescence quantum yield (phi F) and triplet lifetime (tau F) as well as triplet quantum yield (phi T) and lifetime (tau T) were determined. The production of singlet oxygen was also evaluated by photophysical measurements. Photophysical data suggest that DNA photobinding of 1, owing to short fluorescence lifetime value and high triplet quantum yield, occurs likely through triplet mechanism. Interactions between 1 and DNA were studied both in the ground and the excited state. In the ground state 1 undergoes intercalation inside duplex DNA. This fact is also supported by molecular modeling studies. By UVA-light activation 1 photobinds covalently to DNA forming mono and diadducts. The furan side 1-thymine monoadduct, isolated from DNA photomodified by thiopsoralen, shows a cis-syn stereochemistry, in agreement with quantum mechanics studies. Compound 1 photobinds also with linolenic acid, component of lecithins, giving a C4-cycloaddition, and supporting that this compound also induces photolesions at the level of cell membrane, like psoralen. Compound 1 exhibits strong skin-phototoxicity.


Assuntos
Furocumarinas/química , Animais , DNA/química , Adutos de DNA , Ácidos Graxos Insaturados/química , Fluorescência , Furocumarinas/toxicidade , Cobaias , Cinética , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Fosfatidilcolinas/química , Fotoquímica , Pele/efeitos dos fármacos , Pele/efeitos da radiação , Estereoisomerismo , Raios Ultravioleta
20.
Photochem Photobiol ; 63(5): 577-82, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8628748

RESUMO

Photopheresis is an extracorporeal form of photochemotherapy with 8-methoxypsoralen (8-MOP) and UVA (PUVA). Patients ingest 8-MOP and then a psoralen-rich buffy coat is obtained by centrifugation and mixed with saline. This mixture is recirculated through a UVA radiation field and then reinfused. Photopheresis appears to be effective for several T cell-mediated disorders, because the treatment results in a specific immune response against the pathogenic clone of T cells involved. With PUVA therapy, the whole body of the patient is exposed to UVA, after ingestion of 8-MOP. Upon UVA exposure 8-MOP binds to, amongst others, DNA and induces DNA monoadducts and interstrand cross-links. As a result of these photoadducts photocarcinogenicity is a risk in PUVA. In PUVA for psoriasis, it proved that angular furocoumarins, although almost incapable of inducing DNA cross-links (less carcinogenic), are still effective. In order to determine if monoadducts induced by photopheresis could also be effective we used, specifically, 4,6,4'-trimethylangelicin (TMA). In this report, we compare the photodegradation of both TMA and 8-MOP under conditions relevant to the in vivo situation, as well as the effect both compounds have on the viability of rat lymphocytes as measured with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. We show that TMA did not induce immunosuppression in vivo, even after extensive irradiation. In addition a dose dependency of 8-MOP/UVA versus the induced immune suppression was carried out. It was shown that there is a log dose/response correlation of r=0.9205.


Assuntos
Furocumarinas/farmacologia , Imunossupressores/farmacologia , Metoxaleno/farmacologia , Fotoferese , Fármacos Fotossensibilizantes/farmacologia , Raios Ultravioleta , Animais , Relação Dose-Resposta à Radiação , Humanos , Cinética , Masculino , Ratos , Ratos Wistar
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