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1.
J Eur Acad Dermatol Venereol ; 36(12): 2430-2437, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35920760

RESUMO

BACKGROUND: Childhood maltreatment (CM) is related to poor physical and mental health outcomes in adults. Knowledge on the impact of CM on skin diseases is limited, and no study has previously addressed the association of CM with atopic dermatitis (AD) in adult age. OBJECTIVES: To analyse the prevalence of CM in individuals with physician-diagnosed AD, and to examine the relationship between different types of CM with physician-diagnosed AD in a general population sample of German adults. METHODS: Data from 2973 participants from the cross-sectional population-based Study of Health in Pomerania (SHIP) TREND-0 were analysed (aged 20 to 83 years; 51.4% female). We administered the Childhood Trauma Questionnaire (CTQ) assessing emotional, physical and sexual abuse, and emotional and physical neglect. AD was diagnosed by dermatologists in a standardized clinical examination. We conducted logistic regression analyses adjusted for age, sex and school education to investigate the association of CM types with AD. RESULTS: Among all individuals with AD, 20.6% reported to have experienced at least one type of moderate or severe CM. Emotional and physical neglect were the most frequently reported CM types. Overall, the prevalence of CM types among individuals with AD did not differ from those among individuals without AD. We found no association of CM type with AD. CONCLUSIONS: This is the first study investigating the association of CM with AD in adults. CM was common in the present general population sample, emphasizing that CM is an important public health problem. Our findings suggest that CM is not a risk factor for AD. It might be hypothesized that AD severity is a crucial outcome, and that CM history is a factor with impact on disease severity and course rather than a risk factor for the development of AD. Longitudinal studies are required to address this question.


Assuntos
Maus-Tratos Infantis , Dermatite Atópica , Adulto , Criança , Humanos , Feminino , Masculino , Estudos Transversais , Maus-Tratos Infantis/psicologia , Estudos de Coortes , Dermatite Atópica/epidemiologia , Inquéritos e Questionários
2.
GMS Z Med Ausbild ; 30(3): Doc34, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24062814

RESUMO

OBJECTIVE: The present questionnaire survey investigated student reception of problem-based learning (PBL) in the orthodontic curriculum with regard to acceptance, sense of purpose and motivation, knowledge and understanding, as well as tutorial support. METHODS: Over a period of two terms, we compared two different didactic methods (PBL and short presentations) by randomizing the participants of a course on orthodontic diagnostics into two different groups, who inversed methods after the first term. RESULTS: The two student groups did not show any significant differences with regard to assessments or examination performance. Therefore, acceptance of the PBL concept seems to be mainly associated with the motivation of individuals to use this method. The higher the motivation, the more positive is the attitude towards the PBL concept. Students seem to work more constructively and efficiently with PBL if they can judge the concept meaningful for themselves. CONCLUSION: In consideration of the relevant literature and the present results, PBL can be principally integrated into the dental curriculum as a method of learning. However, student motivation is vital to learning success.


Assuntos
Atitude do Pessoal de Saúde , Ortodontia/educação , Aprendizagem Baseada em Problemas , Estudantes de Odontologia/psicologia , Adulto , Currículo , Diagnóstico Bucal/educação , Feminino , Alemanha , Humanos , Masculino , Projetos Piloto , Inquéritos e Questionários
3.
Phytother Res ; 24(2): 249-51, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19585471

RESUMO

Classic synthetic antidepressant drugs, as well as St John's wort extract (SJW), directly inhibit the re-uptake of norepinephrine (NE) and/or serotonin (5-HT) into pre-synaptic axons. With chronic treatment they induce adaptive changes in a number of neurotransmitter receptors in synaptic membranes. The immediate effects of SJW Ze 117, an extract low in hyperforin content, on the specific dopamine (DA) uptake were studied in rat striatal brain slices and compared with the effects on NE and 5-HT uptake in rat cortical brain slices. Specific DA uptake was inhibited in a dose dependent manner. In contrast to the findings in synaptosomal preparations published so far, the extract showed different inhibitory potencies for the respective transporters. The potencies for the uptake inhibition of NA, DA and 5-HT were 30, 7 and 1, respectively. The results indicate that the SJW Ze 117 extract interferes in three ways with the individual uptakes of the relevant neurotransmitters that are considered to be causal in the development of depression. This observation, the concomitant and potent inhibition of DA re-uptake by SJW extract, may additionally provide a rationale for the treatment of nicotine or drug addiction with SJW.


Assuntos
Corpo Estriado/efeitos dos fármacos , Inibidores da Captação de Dopamina/farmacologia , Dopamina/metabolismo , Hypericum/efeitos adversos , Extratos Vegetais/farmacologia , Animais , Antidepressivos/farmacologia , Córtex Cerebral/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Técnicas In Vitro , Norepinefrina/metabolismo , Ratos , Ratos Wistar , Serotonina/metabolismo
4.
Environ Technol ; 28(5): 479-89, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17615957

RESUMO

The off-gas method can be used to investigate standard oxygen transfer efficiencies under process conditions (alphaSOTE) over the operating life of an aeration system. A method to evaluate alphaSOTE is described in detail by US and German standards. The standards, however, do not describe how to evaluate dynamic changes in aSOTE over a day, which can be useful to uncover problems and unfavourable process conditions. Based on over three years experience gained in off-gas testing in Berlin wastewater treatment plants (WWTPs) under operating conditions, a method to evaluate and interpret the dynamic changes in oxygen transfer is presented. The application of the dynamic off-gas method brings important additional information, which can be used to increase operational efficiency of the aeration basin and to increase process reliability, with a relatively small increase in effort. This paper shows how to perform dynamic measurements under process conditions. Some results of such measurements under dynamic process conditions, performed in a Berlin WWTP, are discussed.


Assuntos
Arquitetura de Instituições de Saúde , Oxigênio/química , Eliminação de Resíduos Líquidos/métodos , Difusão , Recuperação e Remediação Ambiental , Gases , Alemanha , Resíduos Industriais , Esgotos/química , Fatores de Tempo , Estados Unidos
5.
Eur J Dent Educ ; 11(2): 93-8, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17445005

RESUMO

Revised regulations in Germany have allowed new curricular concepts to be introduced into the undergraduate dental curriculum. In the first 2 years of the dental curriculum at the University of Greifswald, a new teaching concept which is based on the interactions between Community Medicine and Dentistry has been introduced. It emphasises the importance of early patient contact in providing experience for students. The course consists of three principal elements: student-patient contacts in the patient's home; problem-based learning tutorials to discuss patient cases; and special training in communication skills. The aim of the course is to give students an insight into the patient's view of the illness and treatment, and the effect of their condition on his or her lifestyle. The students also learn about the communal perspective (health survey, intervention planning and implementation in a community). The first four courses were evaluated by questionnaires from the students before and after the 2-year course to assess the concept from the students' perspective. The results indicate that it is possible to provide considerable improvement of the medical/dental education as regards communication skills and understanding of the patients' perceptions, by letting the student establish contact with patients at the very beginning of the curriculum.


Assuntos
Relações Dentista-Paciente , Educação em Odontologia/métodos , Modelos Educacionais , Assistência ao Paciente , Comunicação , Odontologia Comunitária/educação , Currículo , Alemanha , Humanos , Aprendizagem Baseada em Problemas , Inquéritos e Questionários
6.
Z Gerontol Geriatr ; 39(2): 90-9, 2006 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-16622630

RESUMO

According to Antonovsky, the sense of coherence (SOC) determines health and wellbeing. This life orientation is shaped up to the age of 30 and is supposed to remain constant up to senior age. In a field study, in which the SOC, psycho-social resources and subjective health were assessed at three points in time, it could be shown for the first time that the SOC in old age can be malleable and expanding. The master sample (time t(1)) consisted of N = 58 active and "healthy" seniors at the mean age of 66.3 years (65.5% female), who decided to take part in a 14-week program focusing on physical activity and/or self-reflection (endurance training, strength training, yoga, or meditation), respectively. One year before, 90% of them had participated in the Greifswald Aging Study (t0). The intervention study was attended regularly by n = 42 persons (t1 and t2). The SOC and associated health appraisals remained constant over a period of one year (t0-t1); re-test reliabilities varied from satisfactory to very good. Overall, the current SOC (t1) was more important than the past SOC (t0) in accounting for current well-being (t1). The intervention (t1-t2) revealed that the elderly's SOC was significantly strengthened-independently of the program they took part in. Correspondingly, participants' wellbeing, subjective health and psycho-social resources were enhanced. Taking part in a systematic, age-based and group-oriented program that encourages an active and productive every-day life brings about coherence-promoting and health-promoting life experiences in old age.


Assuntos
Adaptação Psicológica , Envelhecimento , Avaliação Geriátrica , Promoção da Saúde , Idoso , Envelhecimento/fisiologia , Envelhecimento/psicologia , Atitude Frente a Saúde , Conscientização , Interpretação Estatística de Dados , Educação , Exercício Físico , Feminino , Humanos , Controle Interno-Externo , Masculino , Estado Civil , Meditação , Autoimagem , Apoio Social , Inquéritos e Questionários , Yoga
7.
Water Environ Res ; 77(5): 447-54, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16274078

RESUMO

The aeration systems of two full-scale, activated-sludge basins were compared during a period of three years, under the same operating conditions, using dynamic offgas testing. Only the material of the diffuser was different (membrane versus ceramic-tube diffusers). The investigation has shown that, although the membrane diffusers have higher initial standard-oxygen-transfer efficiency (alphaSOTE) and standard-aeration efficiency (alphaSAE), these decreased over time, while the alphaSAE of the ceramic diffusers started lower, but increased slightly over the whole period. A cost comparison makes clear how important it is to evaluate the aeration system under process conditions. The operating costs were the dominant factor (approximately 10x higher than capital costs), and operating costs were approximately 20% higher for membrane versus ceramic diffusers. The poor performance of the membrane-tube diffusers under process conditions could be explained on the basis of the actual alphaAE values in the basin, not the standardized values.


Assuntos
Cerâmica , Eliminação de Resíduos de Serviços de Saúde/instrumentação , Eliminação de Resíduos de Serviços de Saúde/métodos , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Reatores Biológicos , Difusão , Eliminação de Resíduos de Serviços de Saúde/economia , Oxigênio/química , Esgotos/química , Fatores de Tempo , Eliminação de Resíduos Líquidos/economia
8.
Artigo em Alemão | MEDLINE | ID: mdl-16003574

RESUMO

In the EU, Germany is one of the countries showing the lowest birth rate and the highest childlessness rate. The desire for a child competes with a variety of life goals that are propagated as valuable in an achievement-centered society. Psychologically speaking, it can be conceived of as a complex and highly ambivalent conflict between options. In view of adverse societal conditions, women and men at a fertile age face the problems of arbitration and of action insecurity, both of which are associated with the delay of the desire for a child and with abandonment of offspring, respectively. In this article, the socio-structural conditions of the desire for a child and of childlessness are specified, referring to relevant representative surveys, and important steps for overcoming this crisis are suggested.


Assuntos
Coeficiente de Natalidade , Educação Infantil , Características da Família , Serviços de Planejamento Familiar/estatística & dados numéricos , Comportamento Reprodutivo/estatística & dados numéricos , Fatores Socioeconômicos , Demografia , Feminino , Alemanha/epidemiologia , Humanos , Recém-Nascido , Masculino
9.
Water Sci Technol ; 52(12): 141-9, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16477981

RESUMO

In order to develop a process control scheme to reduce energy costs for aeration in activated sludge systems with biological P removal, pre-denitrification and nitrification stages, the spatial distribution of carbon oxidation and nitrification was evaluated over a long full-scale plug flow aeration basin using an externally measured specific oxygen uptake rate (sOUR) and in basin measurement of the actual specific oxygen transfer rate (sOTR) with off-gas testing as well as with the calculated oxygen demand from NH4-N concentrations (sOTR(N)). Using a simple static model, a gas phase balance on oxygen and carbon dioxide, sOTR(N) values were also calculated from off-gas testing. Comparison of sOTR(N) to sOTR and sOUR for carbon oxidation (sOUR(C)) to nitrification (sOUR(N)) at different loading conditions allowed the oxidation processes to be followed over the three zones of the aeration basin. As expected, the distribution depended on the dissolved oxygen concentration (DO) in the basin. However, the major change was in the C-oxidation rate and not the nitrification rate. At a low DO, and when NH4-N was present in the zone, the amount of oxygen transferred for nitrification was nearly the same, but the overall sOTR was lower. The externally measured sOUR was only useful when it was differentiated into sOUR(N) and sOUR(C). sOUR(N) could be used to predict the nitrification rate in the basin. With further refinement, the gas phase balance model has potential to be used to monitor the degree of nitrification over the basin length. This can be integrated into a control scheme to reduce aeration costs by adjusting the DO setpoint according to loading conditions in the


Assuntos
Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Aerobiose , Amônia/isolamento & purificação , Amônia/metabolismo , Carbono/isolamento & purificação , Carbono/metabolismo , Nitritos/química , Nitritos/metabolismo , Oxirredução , Oxigênio/metabolismo , Esgotos/química , Fatores de Tempo , Eliminação de Resíduos Líquidos/economia , Purificação da Água/economia
10.
Water Sci Technol ; 50(7): 61-8, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15553460

RESUMO

The efficiency of the aeration system in a full-scale activated sludge basin with 3 separately controlled aeration zones was improved for the low loading period in summer. The air flow rate to each aeration zone is currently regulated to hold a preset dissolved oxygen concentration (DO). Four different DO setpoint combinations were tested, each one for a one week period, using dynamic off-gas testing to measure the standardised oxygen transfer efficiency (alphaSOTE). As the DO setpoints were lowered, the total air flow rate to the basin decreased initially. A low DO in the first zones slowed biomass activity and pushed the load towards the end of the aeration basin. The relationship between alphaSOTE and the specific diffuser flow rate qD is different for each zone. In Zone 1 there was a strong decrease in alphaSOTE as qD increased, while Zones 2 and 3 were fairly independent of qD, Zone 2 at a higher level than Zone 3. Aeration costs were reduced by 15% for the most efficient combination. To achieve even more savings, a control strategy adjusting oxygen transfer rates over the aeration basin to the necessary oxygen transfer rates is suggested. It is based on changing the DO setpoints to reach the lowest total air flow rate while meeting the effluent requirements.


Assuntos
Oxigênio/metabolismo , Eliminação de Resíduos Líquidos/economia , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/economia , Purificação da Água/métodos , Ar , Movimentos do Ar , Biomassa , Reatores Biológicos , Gases , Nitrogênio/metabolismo , Estações do Ano , Esgotos , Fatores de Tempo
11.
Z Gerontol Geriatr ; 37(5): 366-76, 2004 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-15503075

RESUMO

In this contribution, the significance of the salutogenic model (Antonovsky) and its core concept-the sense of coherence-for research into "successful aging" is explicated on the background of a gerodynamic perspective (Schroots). Common to both approaches is the idea that the basic principle of life is based on imbalance, disease, and suffering (heterostasis). According to this pessimistic view, aging is considered as the individual time dimension on which these inevitable impairments in biological, behavioral, and social respects take place. The continuous increase in entropy (disorder) will finally result in the death of the organism. In the face of gerontological research showing variability and individual plasticity in aging processes-especially for the third age-, the salutogenic question is why some people generally become (very) old and stay healthy. According to the salutogenic model, the sense of coherence determines the (re-)production of order over the life span and mediates the relationship between resources/stressors and health outcome. Considering activity/disengagement theory and the selective optimization with compensation model as an example, the integrative potential of the salutogenic model is shown. Finally, the value of the salutogenic model for the fourth age is discussed. Healthy aging is one chance of human existence, but in no way a collective duty that should be imposed on the individual.


Assuntos
Envelhecimento/fisiologia , Atitude Frente a Saúde , Geriatria/métodos , Nível de Saúde , Controle Interno-Externo , Modelos Psicológicos , Qualidade de Vida , Adaptação Fisiológica/fisiologia , Adaptação Psicológica/fisiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Homeostase/fisiologia , Humanos , Masculino , Autoimagem
12.
Z Gerontol Geriatr ; 37(5): 377-86, 2004 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-15503076

RESUMO

Physical activity is a vital pre-condition for healthy aging and well-being. While the association between objective and subjective health in old age has extensively been investigated, the relationship between objective motor competence-the capability of mastering motor demands in everyday life adequately by using motor resources optimally-and subjective health-related quality of life has not been studied yet. In an interdisciplinary study, 168 active seniors (36 men) at the mean age of 67 (range: 59-89) underwent a test battery assessing motor resources and two objective domains of everyday life motor competence-"Perceiving and Reacting" and "Mastering Complex Situations". Subsequently, participants rated their mental, physical, social, functional health and life satisfaction by questionnaire. Motor competence domains were age-dependent; the strongest decrease was found for "Mastering Complex Situations". Only "Mastering Complex Situations" was predicted by motor resources: competent seniors in this domain were faster in motor activity, simple reactions, body movements following acoustic and optic signals, and showed a stronger handcraft and a higher mobility. Overall, health-related quality of life was contingent upon motor competence: physical and functional health and-to a lesser extent-mental health and life satisfaction showed a systematic but moderate relationship to both motor competence domains. The results emphasize the significance of age-compatible and everyday life-adjusted physical activity for the well-being of elderly persons. Even active elderly persons show deficits in motor competence and should be trained, taking into account individual resources and flaws.


Assuntos
Atividades Cotidianas , Avaliação Geriátrica/métodos , Nível de Saúde , Destreza Motora/fisiologia , Qualidade de Vida , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estatística como Assunto , Análise e Desempenho de Tarefas
13.
Water Sci Technol ; 49(4): 37-43, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15077945

RESUMO

Azo dyes can be only mineralised by chemical oxidation. In this paper the oxidation of Reactive Black 5 (RB 5) and Reactive Orange 96 (RO 96) with concentrations between 35 and 5,700 mgL(-1) (RB 5) and between 20 and 2,050 mgL(-1) (RO 96) was investigated in a lab-scale bubble column. The reactor was modelled for two cases, a completely mixed and a plug flow gas phase. The oxidation rate was influenced by mass transfer for all dye concentrations used. For low dye concentrations mass transfer alone was decisive for the reaction rate showing no enhancement due to chemical reaction, E approximately equal to 1. However, in the region of high dye concentrations, the slope of the ozone concentration profile inside the liquid boundary layer increases more and more with increasing dye concentration as a result of a chemical oxidation. Therefore, the enhancement factor depends on the type and concentration of the azo dyes. For RB 5, a diazo dye, an enhancement factor of E = 5.5 was observed for cd = 2,000 mgL(-1), RO 96, a mono azo dye, with a remarkably higher chemical oxidation rate shows an E = 16 for cd = 2,050 mgL(-1).


Assuntos
Compostos Azo/química , Compostos Azo/isolamento & purificação , Corantes/química , Corantes/isolamento & purificação , Modelos Teóricos , Oxidantes Fotoquímicos/química , Ozônio/química , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Cinética , Oxirredução
14.
HNO ; 51(11): 921-30, 2003 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-14605713

RESUMO

The voice handicap index (VHI) was developed in the United States for subjective evaluation of a voice disturbance by the patient. The translation into German has been applied for a German population of patients. It was validated by the examination of 316 adult patients, 221 female and 95 male. The reliability of the VHI rests on a high Cronbach's alpha (0.96). A factor analysis in order to structure the items yields four factors that can be interpreted as negative voice experience (factor 1-explaining 20.83% of the variance after rotation), lack of assertiveness (factor 2-18.82%), lack of vocal power (factor 3-12.84%), and negative emotionality (factor 4-11.01%). The mean VHI scores differ significantly from each other in different degrees of voice disturbance as estimated by the patients themselves. The voice handicap index is qualified as a diagnostic tool for German-speaking countries.


Assuntos
Avaliação da Deficiência , Perfil de Impacto da Doença , Distúrbios da Voz/diagnóstico , Adolescente , Adulto , Animais , Criança , Feminino , Rouquidão/diagnóstico , Rouquidão/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria , Qualidade de Vida/psicologia , Reprodutibilidade dos Testes , Distúrbios da Voz/psicologia
15.
Chemosphere ; 52(6): 1069-77, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12781240

RESUMO

A kinetic model for the decolorization of C.I. Reactive Black 5 by the combination of hydrogen peroxide and UV radiation was developed based on experimental results and known chemical and photochemical reactions. The observed kinetic reaction coefficient was determined and correlated as a function of hydrogen peroxide concentration and UV intensity. The validity of the rate expression was tested experimentally in a parameterization study. The decolorization rate follows pseudo-first order kinetics with respect to dye concentration. The rate increases linearly with UV intensity and nonlinearly with increasing hydrogen peroxide concentration, going from a linear relationship at low H(2)O(2) concentrations to a maximum as hydrogen peroxide concentration continues to increase. The decolorization rate expression derived from the proposed reaction mechanism was reconciled with that used for correlating the experimental data.


Assuntos
Compostos Azo/química , Corantes/química , Peróxido de Hidrogênio/química , Naftalenossulfonatos/química , Cinética , Modelos Químicos , Fotoquímica , Valores de Referência , Raios Ultravioleta , Purificação da Água/métodos
16.
Water Sci Technol ; 46(4-5): 257-64, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12361018

RESUMO

Surface waters are often burdened with inflows of low quality water, so that drinking-water production, swimming or ground water charging must be restricted. To ensure the long-term use of such surface water it is necessary to treat the influents or the water used for ground water charging. The current treatment process for phosphorus and turbidity removal is a process combination called floc filtration. By using this conventional method it is possible to reduce the dissolved ortho-phosphate and the turbidity (particulate phosphorus) as well as the amounts of algae and pathogenic organisms to very low concentrations. The high degree of reduction is only achieved by a relatively high dosage of chemicals. A comparison will be made between this process, which represents the state-of-the-art, and the combination of precipitation/coagulation with micro-/ultrafiltration in dead-end filtration mode.


Assuntos
Fósforo/isolamento & purificação , Purificação da Água/métodos , Abastecimento de Água , Filtração , Floculação , Membranas Artificiais , Fósforo/química , Eliminação de Resíduos Líquidos/métodos
17.
Water Sci Technol ; 46(4-5): 317-24, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12361027

RESUMO

The aeration systems of two full-scale activated sludge basins were compared over 2.5 years under the same operating conditions using dynamic off-gas testing. Only the material of the diffuser was different, membrane vs. ceramic tube diffusers. The experimental design took the complexity and dynamics of the system into consideration. The investigation has shown that, although the membrane diffusers have higher initial standard oxygen transfer efficiency (SOTE) and standard aeration efficiency (SAE), these decreased over time, while the SAE of the ceramic diffusers started lower, but increased slightly over the whole period. Measurement of air distribution in the basins along with dissolved oxygen concentration profiles have provided important information on improving process control and reducing energy costs. The results show that dynamic off-gas testing can effectively be used for monitoring the aeration system and to check design assumptions under operating conditions. The information can be used to improve the design of new aeration systems or in retro-fitting existing basins.


Assuntos
Arquitetura de Instituições de Saúde , Esgotos/química , Eliminação de Resíduos Líquidos/métodos , Cerâmica , Difusão , Gases , Membranas Artificiais , Oxigênio/análise
18.
Water Sci Technol ; 44(5): 295-301, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11695473

RESUMO

C.I. Reactive Black 5 is one of the most used reactive dyes for textile finishing. It is a diazo dye, which can be decolorized by facultative anaerobic bacteria, sulfate reducing bacteria and aerobic white rot fungi. Mineralization by microorganisms has proven difficult. Advanced oxidation processes are promising alternatives for the decolorization and mineralization of Reactive Black 5, alone and in combination with aerobic biodegradation. The kinetics of the decolorization of Reactive Black 5 using a combination of hydrogen peroxide and UV radiation have been investigated. The rate of decolorization is first order with respect to dye concentration. It is enhanced with increasing hydrogen peroxide concentrations up to an optimum value. In our model we have correlated an empirical reaction rate expression which considers the contribution of both hydrogen peroxide and UV flux radiation based on the reaction kinetics. This empirical correlation agrees well with the experimental data for these conditions. Complete decolorization corresponded with 40-50% mineralization of the dye. Further mineralization can be achieved with extended radiation time.


Assuntos
Corantes/química , Peróxido de Hidrogênio/química , Naftalenossulfonatos/química , Oxidantes/química , Purificação da Água/métodos , Cinética , Minerais , Fotoquímica , Raios Ultravioleta
19.
Clin Exp Allergy ; 31(8): 1310-20, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11529903

RESUMO

BACKGROUND: Priming of eosinophils with granulocyte-macrophage colony-stimulating factor (GM-CSF) and subsequent stimulation with platelet-activating factor (PAF) or the anaphylatoxin C5a is associated with a rapid production of leukotrienes (LTs) and release of eosinophil cationic protein (ECP). OBJECTIVE: This study was designed to determine the effects of the sesquiterpene esters petasin, isopetasin and neopetasin on LT generation and ECP release in eosinophils in vitro. METHODS: The model of eosinophil activation described above was used to induce LT production and ECP release. Cells were incubated with petasins and control inhibitors prior to priming and stimulation. To analyse intracellular steps of eosinophil activation and determine potential drug targets, some key signalling events were studied. Activity of cytosolic phospholipase A2 (cPLA(2)) was measured by analysing the generation of arachidonic acid (AA). Translocation of 5-lipoxygenase (5-LO) was observed using immunofluorescence microscopy. Intracellular calcium concentrations [Ca2+]i were measured by a bulk spectrofluorometric assay. RESULTS: Whereas all three compounds inhibited LT synthesis, ECP release from eosinophils was blocked by petasin only, but not isopetasin or neopetasin. Similarly, PAF- or C5a-induced increases in [Ca2+]i were completely abrogated by petasin only, whereas isopetasin and neopetasin had significant lower blocking efficacy. Moreover, only petasin, but not isopetasin or neopetasin, prevented increases in cPLA(2) activity and 5-LO translocation from the cytosolic compartment to the nucleus envelope in calcium ionophore-stimulated eosinophils. CONCLUSION: These data suggest that different petasins may at least partially block different intracellular signalling molecules. To reduce LT synthesis, isopetasin and neopetasin may act at the level of or distal to 5-LO. In contrast, petasin may inhibit inflammatory effector functions in human eosinophils by disrupting signalling events at the level of or proximal to phospholipase Cbeta (PLCbeta), besides its potential inhibitory activity within mitogen-activated protein kinase (MAPK) and LT pathways.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Leucotrienos , Ribonucleases , Sesquiterpenos/farmacologia , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Proteínas Sanguíneas/antagonistas & inibidores , Cálcio/antagonistas & inibidores , Cálcio/metabolismo , Núcleo Celular/enzimologia , Células Cultivadas , Complemento C5a/antagonistas & inibidores , Cisteína/antagonistas & inibidores , Citoplasma/enzimologia , Inibidores Enzimáticos/farmacologia , Proteínas Granulares de Eosinófilos , Eosinófilos/enzimologia , Humanos , Inflamação/imunologia , Inflamação/prevenção & controle , Antagonistas de Leucotrienos , Inibidores de Lipoxigenase , Fosfolipases A/antagonistas & inibidores , Fosfolipases A2 , Fator de Ativação de Plaquetas/antagonistas & inibidores
20.
Biochem Pharmacol ; 61(8): 1041-7, 2001 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-11286996

RESUMO

A large production of leukotrienes (LTs) can be induced in human eosinophils or neutrophils by priming with granulocyte-macrophage colony-stimulating factor and subsequent stimulation with platelet-activating factor (PAF) or the anaphylatoxin C5a. Here, we investigated the effects of a plant extract of petasites hybridus (Ze339) and its isolated active sesquiterpene ester petasin in these two in vitro cell models. Zileuton, a 5-lipoxygenase inhibitor, was used as a positive control. All compounds inhibited both cysteinyl-LT synthesis in eosinophils and LTB(4) synthesis in neutrophils. In contrast, only Ze339 and petasin, but not zileuton, abrogated PAF- and C5a-induced increases in intracellular calcium concentrations. These data suggest that Ze339 and petasin may block, compared to zileuton, earlier signalling events initiated by G protein-coupled receptors in granulocytes, perhaps at the level of or proximal to phospholipase C(beta). Taken together, petasin appears to be one major active compound of petasites hybridus extract, since it demonstrates the same inhibitory activities on calcium fluxes and subsequent LT generation in both eosinophils and neutrophils as Ze339 does.


Assuntos
Anti-Inflamatórios/farmacologia , Asteraceae/química , Hidroxiureia/análogos & derivados , Macrófagos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Sesquiterpenos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Cálcio/metabolismo , Complemento C5a/metabolismo , Cisteína/metabolismo , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Humanos , Hidroxiureia/farmacologia , Técnicas In Vitro , Leucotrieno B4/metabolismo , Leucotrienos/metabolismo , Macrófagos/metabolismo , Neutrófilos/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Fator de Ativação de Plaquetas/metabolismo , Transdução de Sinais
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