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1.
Open Forum Infect Dis ; 11(7): ofae355, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39015351

RESUMO

Background: In recent years, Vietnam has suffered multiple epizootics of influenza in poultry. Methods: From 10 January 2019 to 26 April 2021, we employed a One Health influenza surveillance approach at live bird markets (LBMs) and swine farms in Northern Vietnam. When the COVID-19 pandemic permitted, each month, field teams collected oral secretion samples from poultry and pigs, animal facility bioaerosol and fecal samples, and animal worker nasal washes at 4 LBMs and 5 swine farms across 5 sites. Initially samples were screened with molecular assays followed by culture in embryonated eggs (poultry swabs) or Madin-Darby canine kidney cells (human or swine swabs). Results: Many of the 3493 samples collected had either molecular or culture evidence for influenza A virus, including 314 (37.5%) of the 837 poultry oropharyngeal swabs, 144 (25.1%) of the 574 bioaerosol samples, 438 (34.9%) of the 1257 poultry fecal swab samples, and 16 (1.9%) of the 828 human nasal washes. Culturing poultry samples yielded 454 influenza A isolates, 83 of which were H5, and 70 (84.3%) of these were highly pathogenic. Additionally, a positive human sample had a H9N2 avian-like PB1 gene. In contrast, the prevalence of influenza A in the swine farms was much lower with only 6 (0.4%) of the 1700 total swine farm samples studied, having molecular evidence for influenza A virus. Conclusions: This study suggests that Vietnam's LBMs continue to harbor high prevalences of avian influenza A viruses, including many highly pathogenic H5N6 strains, which will continue to threaten poultry and humans.

2.
J Infect Dis ; 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38718223

RESUMO

BACKGROUND: COVID-19 remains a global public health challenge due to new immune-evasive SARS-CoV-2 variants and heterogeneous immunity. METHODS: In this cross-sectional study, we evaluated the adaptive immune responses in U.S. active-duty personnel who completed a COVID-19 primary vaccine series and with heterogenous SARS-CoV-2 vaccination and infection histories to 3 previously dominant variants (Ancestral, Delta, BA.5) and 3 circulating variants (XBB.1.5, EG.5, and BA.2.86) in late 2023. Analyses were performed based upon timing (within or beyond 12 months) and type (vaccine or infection) of the most recent exposure. RESULTS: Significant reduction was observed in binding antibodies, neutralization antibodies, memory B cells, and CD8+ T cells against circulating variants compared to previous variants. The reduction in antibody response was more pronounced in those whose most recent exposure was greater than 12 months from enrollment. In contrast, the CD4+ T cell response was largely consistent across all tested variants. The type of most recent exposure was not a significant factor in determining the magnitude of current immune responses. CONCLUSIONS: Administration of the XBB.1.5-based booster is likely to enhance cross-reactive humoral responses against SARS-CoV-2 circulating lineages. Ongoing surveillance of immune responses to emerging variants is needed for informing vaccine composition and timing.

3.
J Pharm Sci ; 104(12): 4132-4141, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26344698

RESUMO

The need for quality control during the manufacturing and distribution of biopharmaceuticals is becoming increasingly necessary. At present, detecting drug degradation through the monitoring of active factor aggregation is accomplished through "invasive" techniques, such as size-exclusion chromatography (SEC), analytical ultracentrifugation (AUC), and so on. Unfortunately, these analytical methods require sampling the drug by opening the drug container that renders the remaining drug unusable regardless of the outcome of the test. Visual inspection, the current non-invasive quality control method is qualitative and can only detect visible particulates. Thus, it will miss sub-visible protein aggregates. In this paper, human insulin preparations were used to demonstrate that the transverse relaxation rate of water protons R2 ((1) H2 O) can serve as a sensitive and reliable indicator to detect and quantify both visible and sub-visible protein aggregates. R2 ((1) H2 O) is measured using a wide-bore low-field bench-top NMR instrument with permanent magnets. Such analysis could be carried out without opening the drug container, thus saving a drug for further use. The results suggest a novel, economical, non-destructive in situ analytical technique that allows for on-the-site quantification of protein aggregation in biopharmaceutical products.


Assuntos
Insulina/química , Água/química , Biofarmácia/métodos , Embalagem de Medicamentos/métodos , Humanos , Espectroscopia de Ressonância Magnética/métodos , Agregados Proteicos/fisiologia , Prótons , Ultracentrifugação/métodos
4.
Dtsch Med Wochenschr ; 137(1-2): 17-22, 2012 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-22180278

RESUMO

BACKGROUND: There is a lack of detailed data about lifestyle counseling and other cardiovascular preventive services in primary care settings in Germany. The objectives of this study were to analyze the provision of these services and to identify associated factors. METHODS: 260 (13 %) out of 2,000 randomly selected general practitioners from Southern Germany, took part in this study and were asked about lifestyle counseling and other preventive services as well as barriers and attitudes. Factors associated with lifestyle counseling were analyzed using chi-square tests and logistic regression. RESULTS: Participating physicians had positive attitudes towards health promotion and prevention. Four out of ten physicians counseled the majority of their patients about diet, physical activity, tobacco and alcohol consumption. Female physicians (odds ratio, OR: 1,98), physicians who were confident about their preventive services (OR: 3,55) and those having risk factor questionnaires in the waiting room (OR: 2,26; all p < 0,05) were more likely to counsel their patients. The most important barriers towards preventive services were patients' lack of adherence (91 %), inadequate reimbursement (80 %) and lack of time (70 %). CONCLUSION: There is a discrepancy between the potential and the implementation of cardiovascular-preventive services in primary care settings. Special trainings of physicians as well as better financial and organizational conditions might help to improve the provision of preventive care.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Medicina Geral/organização & administração , Promoção da Saúde/organização & administração , Medicina Interna/organização & administração , Programas Nacionais de Saúde , Consumo de Bebidas Alcoólicas/prevenção & controle , Atitude do Pessoal de Saúde , Feminino , Alemanha , Comportamentos Relacionados com a Saúde , Implementação de Plano de Saúde/organização & administração , Pesquisa sobre Serviços de Saúde , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Educação de Pacientes como Assunto , Comportamento de Redução do Risco , Abandono do Hábito de Fumar
5.
Geburtshilfe Frauenheilkd ; 72(4): 311-315, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25284837

RESUMO

Purpose: The true prevalence of gestational diabetes in Germany is unknown. Thus, the study's purposes were to estimate the prevalence of gestational diabetes as well as to describe the temporal prevalence trend and to identify determinants. Material and Methods: We calculated prevalence estimates based on two datasets: the register-based German perinatal statistic (n = 650 232) and the maternal self-reports from the German children and youth health survey (KiGGS; n = 15 429). Differences between prevalence estimates were analysed using χ2 and trend tests, and determinants were identified using logistic regression. Results: According to the perinatal statistic, gestational diabetes was present in 3.7 % of pregnant women in Germany in 2010. The prevalence across the years 2001 to 2006 was estimated at 1.9 % which differed significantly from the prevalence estimate derived from the KiGGS dataset for the same period of time (5.3 %; 95 % confidence interval: 4.6-6.1 %). Both datasets show an increasing trend of gestational diabetes (p < 0.001). The risk for gestational diabetes was mainly associated with age, BMI and social class of pregnant women as well as with multiple pregnancies. Conclusion: The lack of significant screening studies among representative samples hampers a sound estimation of the true prevalence of gestational diabetes in Germany. The increasing trend in gestational diabetes might continue due to the projected increase of important risk factors (e.g., maternal age, obesity). Our analyses support the current consensus recommendations regarding standardised gestational diabetes screening.

6.
Dtsch Med Wochenschr ; 135(43): 2119-24, 2010 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-20960382

RESUMO

BACKGROUND AND OBJECTIVE: Previous studies often lack any differentiation between target groups for primary, secondary and tertiary prevention of cardiovascular disease (CVD). The aim of this study was to investigate the target group-specific adherence with lifestyle recommendations in different risk groups. This information may be useful in identifying better starting points for future CVD interventions. METHODS: 2,002 men and women aged 50 to 70 years were selected by random and interviewed about their health status, health behavior and health locus of control. Adherence was defined as regular physical activity, healthy diet, non-smoking, and moderate alcohol consumption. Differences between risk groups were determined using Chi-square tests and stratified logistic regression. RESULTS: Health behavior only varied to a limited extent between the risk groups: physical activity (77.8%), healthy diet (62.2%), moderate alcohol consumption (74.4%), non-smoking (total: 75.7%; healthy respondents 70.9%; risk group 79.1%; CVD patients 74.7%). 29.6% were adherent to lifestyle recommendations. Women were more likely to be adherent than men (35.4% vs. 23.5%). In CVD patients, those living together with a partner were also more likely to have a healthy lifestyle (32.2% vs. 20.0%). Furthermore, health locus of control seems to be an important factor. CONCLUSION: In the age group 50-70 adherence with lifestyle recommendations of almost 30% is rather low and not optimal. Health locus of control as motivational barrier should be taken into account particularly in secondary prevention. There is a need of health behavior interventions not only for persons at increased risk and CVD patients, but also for the (still) healthy. Men, singles and persons with external health locus of control should be particularly addressed by these interventions.


Assuntos
Reabilitação Cardíaca , Doenças Cardiovasculares/prevenção & controle , Comportamentos Relacionados com a Saúde , Indicadores Básicos de Saúde , Controle Interno-Externo , Cooperação do Paciente/estatística & dados numéricos , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Consumo de Bebidas Alcoólicas/prevenção & controle , Doenças Cardiovasculares/etiologia , Dieta com Restrição de Gorduras , Feminino , Alemanha , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Atividade Motora , Fatores de Risco , Fatores Sexuais , Abandono do Hábito de Fumar/estatística & dados numéricos , Facilitação Social
7.
J Nutr Health Aging ; 14(5): 381-5, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20424806

RESUMO

OBJECTIVES: The objectives of this study were to assess the association between perceptions of aging and health behavior, and to identify determinants of a healthy diet. DESIGN: Self-reported data obtained by computer-assisted telephone interviews from 2,002 German participants were analyzed. SETTING: General population. PARTICIPANTS: 982 randomly selected men and 1,020 women aged 50-70 years were surveyed. MEASUREMENTS: The questionnaire consisted of 31 items concerning attitudes on age and aging (5-point Likert scale). Additionally variables including dietary habits, exercise, smoking, alcohol consumption as well as sociodemographic variables were also assessed. Factor and cluster analyses were used to identify typical perceptions of aging. Determinants of a healthy diet were identified by regression analysis. RESULTS: Three different perceptions were found: "fit and performance-hungry" (n=808), "conventional" (n=618), and "easy-going and committed" (n=576). The "fit and performance-hungry" engaged in exercising more regularly and were more likely to follow a healthy diet compared to the other groups in the sample. Diet was associated with attitudes and beliefs and came along with other favorable health behaviors like regular exercising and non-smoking. CONCLUSION: Individuals with a positive perception of aging showed a significantly better health behavior than those who identified themselves with a conventional perception of aging. Individual perceptions of aging are an important starting point when designing prevention programs for older adults.


Assuntos
Envelhecimento/psicologia , Atitude Frente a Saúde , Dieta/psicologia , Dieta/normas , Comportamentos Relacionados com a Saúde , Idoso , Análise por Conglomerados , Análise Fatorial , Comportamento Alimentar , Feminino , Alemanha , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Estilo de Vida , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos
8.
Z Gerontol Geriatr ; 42(2): 145-54, 2009 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-18677629

RESUMO

Stereotypes of ageing affect activity in older adults. However, no representative studies on the impact of "images of ageing" on sporting activity existed until now. In a telephone survey, 2002 over-50s were asked about sporting activity and their opinions about ageing. A factor analysis of the queried attitudes disclosed five dimensions of ageing stereotypes. A subsequent cluster analysis identified three categories of attitudes towards ageing: "fit and performance-hungry", "conventional", and "easy-going and committed". Physical activity was described as the key criterion for a healthy old age in all clusters. Analysis also revealed a significant correlation between cluster affiliation and amount of sporting activity. The percentage of non-exercisers is lowest in Cluster 1, the "fit and performance-hungry" category (29.4%), and highest in Cluster 3, the "worryfree committed" (51.6%). Sports for health and trendy sports are the sports of choice, while conventional sports attract little interest.


Assuntos
Envelhecimento/psicologia , Atitude Frente a Saúde , Atividade Motora , Esportes/estatística & dados numéricos , Estereotipagem , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade
9.
Gesundheitswesen ; 69(7): 401-7, 2007 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-17701839

RESUMO

In a society with an aging population, the preventive healthcare importance of physical activity in middle-aged and older adults is growing. The purpose of the study "Living an active life - age and aging in Baden-Wuerttemberg" is to acquire generalisable data of practical relevance for the 50- to 70-year-old population of Baden-Wuerttemberg. The main themes of this study are sports, exercise, and health-related and lifestyle aspects--from both a current and a biographical perspective. Following conceptualization and a test run, the survey was conducted by means of a computer-assisted telephone interview (CATI) in the period from May to October 2006. 982 men and 1,020 women responded. The percentage of respondents with a high level of education was disproportionately high, as is frequently the case for telephone surveys. Due to the resultant bias, the data was weighted by age, gender and education on the basis of the German Microcensus 2004. In addition to serving as a health report on the middle-aged and older adult population, this basic survey generated representative data on physical/sporting activity among older people in Baden-Wuerttemberg, and can be used as a reliable basis for designing future preventive measures. First analyses show that people with higher educational levels and good health, and non-smokers, people with balanced diet and normal weight are more likely to do sporting activities.


Assuntos
Bases de Dados Factuais , Exercício Físico , Comportamentos Relacionados com a Saúde , Nível de Saúde , Estilo de Vida , Atividade Motora , Esportes , Idoso , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
10.
Chirality ; 13(4): 187-92, 2001 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-11284023

RESUMO

Selective antibodies to (R)-methadone (Mtd) and to its racemate were produced in rabbits by immunization with conjugates of (R)- or (R,S)-hemisuccinyl-methadol-bovine serum albumin, respectively. A hapten was first prepared by reduction of (R)- or (R,S)-Mtd with sodium borohydride, followed by esterification with succinic anhydride. The conjugation of hapten with albumin was achieved by the mixed anhydride method. After immunization of rabbits, the titers and specificity of each antibody were determined by ELISA. The antibodies obtained were tested with (R)-, (S)-, (R,S)-Mtd, its major metabolite (EDDP), and some drugs of abuse (morphine, codeine, cocaine). The sensitivities of antibodies to (R)- and (R,S)-Mtd were about 1 and 2 ng/ml, respectively. Selective (R)-antibodies recognized (R)-Mtd about 40 times more avidly than the (S)-isomer, while an antiserum against (R,S)-Mtd recognized (R)- and (S)-isomers to about the same degree. Both selective antibodies showed little interference (about 0.5%) with EDDP metabolite and no crossreactivity with morphine, codeine, and cocaine. These two selective antibodies were used to develop an immunoenzymatic method (ELISA) for the determination of (R)- and (R,S)-Mtd in serum samples of patients under maintenance treatment for narcotic addiction.


Assuntos
Metadona/sangue , Metadona/imunologia , Animais , Especificidade de Anticorpos , Bovinos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Humanos , Metadona/análogos & derivados , Metadona/síntese química , Coelhos , Sensibilidade e Especificidade , Soroalbumina Bovina , Estereoisomerismo
11.
J Chromatogr B Biomed Sci Appl ; 732(1): 47-53, 1999 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-10517221

RESUMO

A rapid high-performance liquid chromatographic assay with isocratic elution is developed for the simultaneous quantification of valaciclovir (VACV) prodrug and its active converted compound, acyclovir (ACV), in biological fluids of treated patients. For serum, the samples are deproteinized with perchloric acid in presence of 1-methylguanosine as the internal standard (IS). For urine and dialysis liquid, the samples are diluted with a mobile phase containing the IS, then filtered. VACV, ACV and the IS are separated on a SymmetryShield RP-8 column with acetonitrile-ammonium phosphate buffer as the mobile phase and detected at 254 nm. The chromatographic time is about 12 min. The relative standard deviations (RSD) of VACV and ACV standards are between 0.5 and 3.5%. Most endogenous nucleosides and their metabolites, psychotropic drugs and drugs of abuse are shown not to interfere with this technique. The method has been applied to study the pharmacokinetics of VACV and ACV in serum, dialysis liquid and urine of renal failure patients on continuous ambulatory peritoneal dialysis (CAPD) under oral treatment of VACV.


Assuntos
Aciclovir/análogos & derivados , Aciclovir/análise , Líquidos Corporais/química , Cromatografia Líquida de Alta Pressão/métodos , Valina/análogos & derivados , Aciclovir/farmacocinética , Aciclovir/urina , Antivirais/análise , Antivirais/farmacocinética , Antivirais/urina , Humanos , Insuficiência Renal/metabolismo , Reprodutibilidade dos Testes , Valaciclovir , Valina/análise , Valina/farmacocinética , Valina/urina
12.
J Chromatogr B Biomed Sci Appl ; 718(2): 278-84, 1998 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-9840439

RESUMO

A rapid gas-liquid chromatographic assay is developed for the quantification of methadone (Mtd) and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in biological fluids of opiate addicts. After alkaline extraction from samples with lidocaine hydrochloride as internal standard, Mtd and EDDP are separated on SP-2250 column at 220 degrees C and detected with a thermionic detector. The chromatographic time is about 6 min. The relative standard deviations (R.S.D.) of Mtd and EDDP standards are between 1.5 and 5.5%. Most drugs of abuse (morphine, codeine, narcotine, cocaine, benzoylecgonine, cocaethylene, dextropropoxyphene etc) are shown not to interfere with this technique. The method has been applied to study the levels of Mtd and EDDP metabolite in serum, saliva and urine of patients under maintenance treatment for opiate dependence. EDDP levels were found higher than those of Mtd in urine samples from four treated patients, but lower in serum and undetectable in saliva. However, Mtd concentrations were higher in saliva than in serum.


Assuntos
Cromatografia Gasosa/métodos , Metadona/metabolismo , Transtornos Relacionados ao Uso de Opioides/metabolismo , Pirrolidinas/metabolismo , Saliva/metabolismo , Artefatos , Humanos , Metadona/sangue , Metadona/urina , Transtornos Relacionados ao Uso de Opioides/sangue , Transtornos Relacionados ao Uso de Opioides/urina , Pirrolidinas/sangue , Pirrolidinas/urina , Reprodutibilidade dos Testes
13.
J Chromatogr B Biomed Sci Appl ; 700(1-2): 155-63, 1997 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-9390725

RESUMO

The simultaneous determination of methadone (Mtd) enantiomers and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in human urine and serum by enantioselective HPLC using a new Cyclobond 1-2000 RSP column is described. After alkaline extraction from urine or serum with estazolam as an internal standard, Mtd enantiomers and its metabolite (EDDP) are separated on the previous column with reversed-mobile phase and detected at 210 nm. Peak resolutions are about 2.0 for Mtd enantiomers. The relative standard deviations (R.S.D.) of Mtd and EDDP standards are between 0.5 and 4.5%. Most drugs of abuse are shown not to interfere with this technique. The method has been applied to study the levels of each Mtd enantiomer and of its racemic metabolite in urine and serum of patients under maintenance treatment for opiate dependence. In urine, R-(-)-Mtd levels are always higher (about 2+/-0.5-fold) than those of S-(+)-Mtd and in most cases, metabolite concentrations are greater than those of global Mtd enantiomers. However, the R-(-) enantiomer levels of residual drug in serum of some patients were lower than those of its antipode. This method is suitable for pharmacokinetic and toxicological studies of Mtd enantiomers and its major metabolite in biological fluids.


Assuntos
Analgésicos Opioides/sangue , Analgésicos Opioides/urina , Metadona/sangue , Metadona/urina , Transtornos Relacionados ao Uso de Opioides/reabilitação , Pirrolidinas/sangue , Pirrolidinas/urina , Analgésicos Opioides/uso terapêutico , Cromatografia Líquida de Alta Pressão/métodos , Ciclodextrinas , Humanos , Metadona/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/sangue , Transtornos Relacionados ao Uso de Opioides/urina , Reprodutibilidade dos Testes , Estereoisomerismo
14.
Arch Toxicol ; 71(7): 437-42, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9209689

RESUMO

FK506, cyclosporin A (CsA), and its structural analog cyclosporin G (CsG) are immunosuppressant drugs mainly metabolized by hepatic cytochrome P-450 3A (CYP 3A) oxygenase. FK506 metabolites exhibit greater toxicity than the parent drug, while CsA metabolites are far less toxic than CsA itself. The aim of our study was to compare the toxicity of CsG with CsA and FK506 as a function of CYP 3A induction. Hepatocytes from Wistar rats with or without dexamethasone (DEX) induction (200 mg/kg per day, p.o for 4 days) were used in primary culture. The DEX-inductive effect on CYP 3A was assessed by SDS-PAGE. After 6 h incubation with CsG, CsA or FK506 (5 to 200 microM), cell viability (expressed as IC50), intracellular calcium content and apoptosis were evaluated. Concerning cytotoxicity, IC50 values for CsG, CsA and FK506 were 75, 50 and 180 microM respectively in non-induced cultures, and 150, 120 and 25 microM in induced cultures. For intracellular calcium content, a dose-dependent increase was observed in all cultures. However this increase is more important for CsG and CsA in non-induced cultures (150%) compared to induced cultures (110%) at 150 microM. Conversely for FK506, this increase is greater in induced cultures (150%) than in non-induced cultures (127%). Estimation of the percentage of apoptotic cells shows similar variations. Our results show that the toxicity of the three drugs in rat hepatocytes is dependent on CYP 3A induction: increased for FK506, decreased for CsA and CsG. Moreover, with regard to the three tests used, the toxic effects of CsG are close to those of CsA, indicating that CsG metabolites are also less toxic than the parent drug.


Assuntos
Hidrocarboneto de Aril Hidroxilases , Sistema Enzimático do Citocromo P-450/fisiologia , Imunossupressores/toxicidade , Fígado/efeitos dos fármacos , Fígado/enzimologia , Oxirredutases N-Desmetilantes/fisiologia , Animais , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Corantes , Ciclosporina/toxicidade , Citocromo P-450 CYP3A , Citometria de Fluxo , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/metabolismo , Fígado/patologia , Masculino , Ratos , Ratos Wistar , Tacrolimo/toxicidade , Sais de Tetrazólio , Tiazóis
15.
J Lipid Mediat Cell Signal ; 15(2): 203-14, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9034965

RESUMO

The present study was undertaken to evaluate the effects of platelet activating factor (PAF) antagonists, PMS 536 and PMS 549, on LLC-PK1 toxicity induced by Cyclosporin A (CsA). The LLC-PK1 cell line was used as an in vitro model. CsA cytotoxicity was determined in relation with ATP content. Alkaline phosphatase and N-acetyl-beta-glucosaminidase activities, which are directly correlated with tubular cell damage, were used as markers for renal injury. CsA alone provoked in the LLC-PK1 cell line a marked decrease in cell viability (55%) and membrane integrity (56%), and a significant increase in AP and NAG activities and in oxidized glutathione level. The ATP decrease and the ADP increase, resulting in a decline of the ATP/ADP ratio, is indicative of an anoxic energy charge. Co-treatment with CsA plus PMS 536 or PMS 549 resulted in a minor decrease in cell viability and in significant membrane integrity recovery. Moreover, the ATP depletion and the increase in ATP metabolites, hypoxanthine and uric acid induced by CsA were strongly prevented by PAF antagonists. In contrast, GSSG level remained high as in CsA-treated cells, but GSH level was in the range of controls. Our results suggest that both PAF antagonists attenuate CsA oxidative injury and prevent energy metabolism disturbances probably by maintaining cell integrity. The lipophilicity of both molecules may be responsible for membrane stabilization and may confer the protective effects observed in energy metabolism. The results obtained with PMS 536 and PMS 549 are indicative of interactions between PAF and CsA in renal injury and suggest the therapeutic potential of these PAF-antagonists against CsA-induced nephrotoxicity.


Assuntos
Ciclosporina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Piperazinas/farmacologia , Fator de Ativação de Plaquetas/antagonistas & inibidores , Inibidores da Agregação Plaquetária/farmacologia , Acetilglucosaminidase/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Ciclosporina/toxicidade , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Nefropatias/induzido quimicamente , Nefropatias/prevenção & controle , Células LLC-PK1 , Suínos
16.
Arch Toxicol ; 71(8): 529-31, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9248632

RESUMO

FK506 and cyclosporin A (CsA) are two potent immunosupressants with similar toxicity profile. Nephrotoxicity is the main adverse effect of both compounds. The aim of this study is to compare the in vitro nephrotoxic effects on renal epithelial cell line LLC-PK1 by measuring cell viability and energy status as evaluated by concentrations of ATP and ATP metabolites. Cell viability (expressed as IC50 was assessed via thiazolyl blue (MTT) assay after incubation for 4-24 h with FK506 or CsA. ATP and its metabolites were determined by HPLC after 4 and 6 h incubation with FK506 or CsA alone at the respective IC50. Both FK506 and CsA decreased cell viability to similar extents, in a dose- and time-dependent manner. After 4 h incubation, both drugs decreased ATP levels (-25%) and increased uric acid levels. However, the latter percentage increase was twofold higher with CsA (18%) than with FK506 (9%). The energy charge, calculated according to levels of adenine nucleotides, was decreased by 10% in FK506-treated cells and by 27% in CsA-treated cells. At the end of 6-h incubation, FK506-treated cells maintained ATP levels coupled with energy charge at near control levels whereas the levels were 32% lower in CsA treated cells. Compared to the 4 h-incubation, the increase in uric acid was similar for FK506 but was doubled with CsA. The decrease in cell integrity and ATP depletion induced by CsA in LLC-PK1 cells was only transiently observed with FK506. By preserving energy status, FK506 leads to fewer metabolic disturbances than CsA in the renal epithelial cell line LLC-PK1, demonstrating a minor potential nephrotoxicity.


Assuntos
Ciclosporina/toxicidade , Metabolismo Energético/efeitos dos fármacos , Imunossupressores/toxicidade , Tacrolimo/toxicidade , Trifosfato de Adenosina/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Rim/citologia , Rim/efeitos dos fármacos , Células LLC-PK1 , Nucleotídeos/metabolismo , Suínos , Sais de Tetrazólio/toxicidade , Tiazóis/toxicidade , Fatores de Tempo
17.
Int J Immunopharmacol ; 18(1): 79-87, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8732436

RESUMO

Cyclosporin G (CsG), a promising cyclosporin A (CsA) analogue, was examined and compared with two reference immunosuppressive drugs: CsA and FK-506, regarding their inhibitory effects on different lymphocyte activation pathways as well as on graft-versus-host reaction (GvHR) across differences at major or minor histocompatibility loci. The results showed that, at different concentrations, CsG efficiently inhibited proliferation induced by alloantigens (mixed lymphocyte culture), mitogens (concanavalin A, pokeweed mitogen) and the combination of phorbol myristate acetate + ionomycin, to the same extent as observed with CsA and FK-506. It was also shown that CsG exhibited the same strong inhibitory effects as the two other immunosuppressants upon stimulation triggered by viral (MLs-1a) or bacterial (staphylococcal enterotoxin B) superantigen. Determination of IL-2 activity in the supernatant of MLC also confirmed similar strong inhibitory effects, exerted by CsG compared to CsA and FK-506. In systemic and local GvHR across major or minor histocompatibility barriers, CsG as well as CsA and FK-506 presented an equivalent immunosuppressive potential. In conclusion, from various experiments involving different modes of activation, it was shown that CsG was as strongly immunosuppressive as CsA and FK-506.


Assuntos
Ciclosporina/farmacologia , Imunossupressores/farmacologia , Tacrolimo/farmacologia , Animais , Células Cultivadas , Reação Enxerto-Hospedeiro/efeitos dos fármacos , Interleucina-2/biossíntese , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBA
18.
J Chromatogr B Biomed Appl ; 665(1): 125-32, 1995 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-7795782

RESUMO

The determination of propranolol enantiomers in microsamples of human plasma and urine by HPLC using a chiral stationary phase is described. After extraction from 200 microliters of plasma or urine with racemic alprenolol as internal standard (I.S.), the enantiomers are separated on a beta-cyclodextrin column with a polar organic mobile phase and determined by fluorescence detection. The retention times of I.S. and propranolol enantiomers are about 12-13 min and 16-18 min, respectively. Peak resolutions are 1.4 for I.S. and 2.2 for propranolol. The use of alprenolol as I.S. improves significantly the coefficients of variation (C.V.: 0.6-4.2%). Sensitivity is approximately 1.5 ng/ml per propranolol enantiomer. The assay is applied to pharmacokinetic studies of racemic propranolol in human biological fluids. The (S)-propranolol levels are always higher than the (R)-antipode concentrations in plasma and urine.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Propranolol/sangue , Propranolol/urina , beta-Ciclodextrinas , Ciclodextrinas/química , Humanos , Padrões de Referência , Estereoisomerismo
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