RESUMO
Many salamanders can completely regenerate a fully functional limb. Limb regeneration is a carefully coordinated process involving several defined stages. One key event during the regeneration process is the patterning of the blastema to inform cells of what they must differentiate into. Although it is known that many genes involved in the initial development of the limb are re-used during regeneration, the exact molecular circuitry involved in this process is not fully understood. Several large-scale transcriptional profiling studies of axolotl limb regeneration have identified many transcription factors that are up-regulated after limb amputation. Sall4 is a transcription factor that has been identified to play essential roles in maintaining cells in an undifferentiated state during development and also plays a unique role in limb development. Inactivation of Sall4 during limb bud development results in defects in anterior-posterior patterning of the limb. Sall4 has been found to be up-regulated during limb regeneration in both Xenopus and salamanders, but to date it function has been untested. We confirmed that Sall4 is up-regulated during limb regeneration in the axolotl using qRT-PCR and identified that it is present in the skin cells and also in cells within the blastema. Using CRISPR technology we microinjected gRNAs specific for Sall4 complexed with cas9 protein into the blastema to specifically knockout Sall4 in blastema cells only. This resulted in limb regenerate defects, including missing digits, fusion of digit elements, and defects in the radius and ulna. This suggests that during regeneration Sall4 may play a similar role in regulating the specification of anterior-proximal skeletal elements.
Assuntos
Ambystoma mexicanum , Padronização Corporal , Extremidades , Regeneração , Fatores de Transcrição , Animais , Regeneração/genética , Regeneração/fisiologia , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Extremidades/fisiologia , Extremidades/embriologia , Ambystoma mexicanum/genética , Ambystoma mexicanum/fisiologia , Padronização Corporal/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Proteínas de Anfíbios/genética , Proteínas de Anfíbios/metabolismoRESUMO
The ability to adopt novel tools continues to become more important for governments and environmental managers tasked with balancing economic development, social needs and environmental protection. An example of an emerging technology that can enable flexible, cost-effective data collection for conservation and environmental management is Unmanned Aerial Vehicles (UAVs). It is clear that UAVs are beginning to be adopted for a diversity of purposes, identification of barriers to their use is the first step in increasing their uptake amongst the environmental management community. Identifying the barriers to UAV usage will enable research and management communities to confidently utilise these powerful pieces of technology. However, the implementation of this technology for environmental research has received little overall assessment attention. This systematic literature review has identified 9 barrier categories (namely Technological, Analytical and Processing, Regulatory, Cost, Safety, Social, Wildlife impact, work suitability and others) inhibiting the uptake of UAV technologies. Technological barriers were referenced in the literature most often, with the inability of UAVs to perform in poor weather (such as rain or windy conditions) commonly mentioned. Analytical and Processing and Regulatory barriers were also consistently reported. It is likely that some barriers identified will lessen with time (e.g. technological and analytical barriers) as this technology continues to evolve.
Assuntos
Animais Selvagens , Dispositivos Aéreos não Tripulados , Animais , Tecnologia de Sensoriamento Remoto , Tecnologia , Coleta de DadosRESUMO
Automatic stop-orders (ASOs) have been utilized to discourage inappropriately prolonged antibiotic therapy. An ASO policy, which required reordering of antibiotics after 7 days of therapy, had been in place at our institution prior to 2002, but was revoked after instances of compromised patient care due to inadvertent and inappropriate interruption of antimicrobial treatment. The objective of this study was to evaluate the impact of revoking the ASO policy on the duration of antibiotic therapy, infection-related outcome (cure vs failure), relapsing infection, occurrence of resistant bacteria and superinfection in patients with nosocomial pneumonia. A retrospective chart review of adult patients (≥ 18 years old) admitted to Sunnybrook Health Sciences Centre with nosocomial pneumonia requiring antibiotic therapy was conducted. Duration of antibiotic therapy, infection-related outcome (cure vs failure), rate of relapsing infection, resistant organisms and superinfection were determined for each cohort. Forty-six eligible adults with nosocomial pneumonia per cohort were included [corrected]. Duration of antibiotic therapy was not significantly different in the pre- (11.4 ± 3.8 days) compared with the post-ASO revocation cohort (10.8 ± 4.1 days; p=0.43). There were also no significant differences between the cohorts with regard to infection-related outcome (cure vs failure), relapsing infection, or the occurrence of resistant bacteria or superinfection (p>0.5). Revocation of the ASO policy for antibiotics at our institution was not associated with a longer duration of antibiotic therapy, or increased incidence of infection-related mortality, relapsing infection, resistant bacteria or superinfection for patients with nosocomial pneumonia.
Assuntos
Antibacterianos/administração & dosagem , Infecção Hospitalar/tratamento farmacológico , Pesquisa sobre Serviços de Saúde , Pneumonia Bacteriana/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/mortalidade , Farmacorresistência Bacteriana , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Pneumonia Bacteriana/epidemiologia , Pneumonia Bacteriana/microbiologia , Pneumonia Bacteriana/mortalidade , Recidiva , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
Cefazolin plus tobramycin have been determined to be effective for community-acquired FN, but have not been evaluated in the treatment of nosocomial FN. This study compared the incidence of mortality from 2002 to 2004 with 2008 to 2009 in patients with nosocomial FN treated with cefazolin plus tobramycin and compared characteristics of patients with nosocomially acquired FN to community acquired FN. A retrospective chart review of 45 nosocomial FN episodes from 2008 to 2009, and 54 episodes from 2002 to 2004 treated with cefazolin plus tobramycin was conducted. Data on the community acquired FN episodes was obtained from our previous research. Nosocomial FN mortality increased from 4% in 2002-2004 to 13% in 2008-2009 (p = 0.08). The nosocomial cohort was at higher risk of medical complications and mortality than the community-acquired cohort based on several variables (neutrophil nadir, duration of neutropenia and fever, hematological malignancy, MASCC and Talcott score; p < 0.05). As a result, the nosocomial cohort was treated with longer courses of antibiotic therapy (14 days vs 7 days; p < 0.0001) and were more likely to require broader spectrum antibiotics (64 out of 99 vs 34 out of 96; p < 0.0001). There was an observed increased risk of mortality from 2002 to 2004 compared with 2008 to 2009 in patients treated with cefazolin plus tobramycin for nosocomial FN, this was notable despite not attaining statistical significance. Therefore, this regimen is not appropriate for nosocomial FN.
Assuntos
Antibacterianos/administração & dosagem , Cefazolina/administração & dosagem , Infecções Comunitárias Adquiridas/tratamento farmacológico , Infecção Hospitalar/tratamento farmacológico , Febre de Causa Desconhecida/tratamento farmacológico , Neutropenia/diagnóstico , Tobramicina/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Infecções Comunitárias Adquiridas/mortalidade , Infecção Hospitalar/mortalidade , Feminino , Febre de Causa Desconhecida/complicações , Febre de Causa Desconhecida/mortalidade , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida , Adulto JovemRESUMO
BACKGROUND AND AIMS: Evaluation of metabolic syndrome (MetS) characteristics across an age spectrum from childhood to adulthood has been limited by a lack of consistent MetS criteria for children and adults and by a lack of adjustment for environmental factors. We used the pediatric and adult International Diabetes Federation (IDF) criteria to determine whether gender-specific and race-specific differences in MetS and its components are present in adolescents as in adults after adjustment for socio-economic status (SES) and lifestyle factors. METHODS AND RESULTS: Waist circumference, blood pressure, triglycerides, HDL cholesterol, and fasting glucose measures were obtained from 3100 adolescent (12-19 years) and 3419 adult (20-69 years) non-Hispanic white, non-Hispanic black, and Mexican-American participants of the 1999-2006 National Health and Nutrition Examination Surveys. We compared odds of having MetS and its components across racial/ethnic groups by age group, while adjusting for income, education, physical activity and diet quality. After adjusting for possible confounding influences of SES and lifestyle, non-Hispanic-black adolescent males exhibited a lower odds of MetS and multiple components (abdominal obesity, hypertriglyceridemia, low HDL, hyperglycemia) compared to non-Hispanic-white and Mexican-American adolescents. Compared to non-Hispanic-white adolescent males, Mexican-American adolescent males had less hypertension. There were no differences in MetS prevalence among adolescent females, though non-Hispanic-black girls exhibited less hypertriglyceridemia. CONCLUSION: Racial/ethnicity-specific differences in MetS and its components are present in both adolescence and adulthood, even after adjusting for environmental factors. These data help strengthen arguments for developing racial/ethnic-specific MetS criteria to better identify individuals at risk for future cardiovascular disease.
Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Meio Ambiente , Hispânico ou Latino/estatística & dados numéricos , Síndrome Metabólica/epidemiologia , População Branca/estatística & dados numéricos , Adaptação Psicológica , Adolescente , Adulto , Idoso , Pressão Sanguínea , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/epidemiologia , Criança , HDL-Colesterol/sangue , Estudos Transversais , Feminino , Humanos , Hipertensão/sangue , Hipertensão/epidemiologia , Estilo de Vida , Modelos Logísticos , Masculino , Síndrome Metabólica/diagnóstico , Pessoa de Meia-Idade , Inquéritos Nutricionais , Razão de Chances , Prevalência , Estudos Retrospectivos , Fatores de Risco , Fatores Socioeconômicos , Triglicerídeos/sangue , Circunferência da Cintura , Adulto JovemRESUMO
AIMS: Albiglutide is a glucagon-like peptide-1 (GLP-1) mimetic generated by genetic fusion of a dipeptidyl peptidase-IV-resistant GLP-1 dimer to human albumin. Albiglutide was designed to retain the therapeutic effects of native GLP-1 while extending its duration of action. This study was conducted to determine the pharmacokinetics and initial safety/tolerability profile of albiglutide in non-diabetic volunteers. METHODS: In this single-blind, randomized, placebo-controlled trial, 39 subjects (18-60 years, body mass index 19.9-35.0 kg/m(2)) received placebo (n = 10) or escalating doses of albiglutide (n = 29) on days 1 and 8 in the following sequential cohorts: cohort 1: 0.25 + 1 mg; cohort 2: 3 + 6 mg; cohort 3: 16 + 24 mg; cohort 4: 48 + 60 mg; and cohort 5: 80 + 104 mg. Dose proportionality was evaluated based on area under the plasma drug concentration versus time curve [area under the curve (AUC((0-7 days)))] and maximum plasma drug concentration (C(max)) for cohorts 2-5 during week 1. RESULTS: Albiglutide had a terminal elimination half-life (T(1/2)) of 6-8 days and time to maximum observed plasma drug concentration (T(max)) of 3-4 days. A greater-than-dose proportional increase in albiglutide exposure was observed. Albiglutide demonstrated a dose-dependent trend in reductions of glucose weighted mean AUC and fructosamine levels in healthy subjects. The incidence and severity of adverse events (AEs) was similar between placebo and albiglutide groups. Headache was the most frequent drug-related AE, followed by constipation, flatulence and nausea. CONCLUSIONS: Albiglutide has a half-life that favours once weekly or less frequent dosing with an acceptable safety/tolerability profile in non-diabetic subjects.
Assuntos
Peptídeo 1 Semelhante ao Glucagon/farmacologia , Adulto , Área Sob a Curva , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Relação Dose-Resposta a Droga , Feminino , Peptídeo 1 Semelhante ao Glucagon/análogos & derivados , Hemoglobinas Glicadas/metabolismo , Meia-Vida , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto JovemRESUMO
Fluoroquinolone-resistance among pneumococci is low; however the number of isolates with a single ParC mutation has increased. Consequently, more potent agents are needed to minimize resistance selection. We investigated the efficacy of ertapenem versus gatifloxacin in a temperature-sensitive mouse model of pneumonia caused by a wildtype Streptococcus pneumoniae strain (A66) and an isogenic mutant with a ParC mutation (R222). Treatment started at 24 h and lasted for 5 days. Temperature was used to assess disease progression before and during treatment. Of mice infected with either strain and treated at an early stage of infection, 79-94% of those given ertapenem survived compared with 56-61% given gatifloxacin. If treated at a later stage, the results were similar for ertapenem (71-84%) but were considerably lower for gatifloxacin (17-33%). Ertapenem was as bactericidal as gatifloxacin against A66 (94-100% vs 92-100%) but was superior to gatifloxacin against R222 (95-100% vs 50-77%). Ertapenem is a promising new treatment for patients with pneumococcal pneumonia, including those at risk of infection with a fluoroquinolone-resistant strain.
Assuntos
Antibacterianos/uso terapêutico , Fluoroquinolonas/uso terapêutico , Pneumonia Pneumocócica/tratamento farmacológico , Streptococcus pneumoniae/efeitos dos fármacos , beta-Lactamas/uso terapêutico , Animais , Antibacterianos/farmacologia , DNA Topoisomerase IV/genética , Modelos Animais de Doenças , Ertapenem , Fluoroquinolonas/farmacologia , Gatifloxacina , Camundongos , Camundongos Endogâmicos , Mutação , Streptococcus pneumoniae/genética , Temperatura , Resultado do Tratamento , beta-Lactamas/farmacologiaRESUMO
Standard 7-14 day (d) courses of antimicrobial therapy for community-acquired pneumonia (CAP) are thought to have contributed to the emergence of resistant pneumoccoci. Consequently, short-course fluoroquinolone regimens have been proposed to minimize resistance. To test this, we examined 2-day versus 5-day regimens of gemifloxacin and levofloxacin for treatment of pneumonia in a murine model. In doing so, we also investigated whether the enhanced potency of gemifloxacin would influence outcomes. CD1 Swiss mice were infected intratracheally with 10(5)-CFU of a virulent Streptococcus pneumoniae strain. Drugs were administered every 8 h for 2 d and 5 d, starting at 24 h postinfection. Temperature was used to assess disease progression. Gemifloxacin remained effective for 2 d and 5 d, with survival rates of 100%-83% compared with 40%-58% for levofloxacin. Eighty-nine to 100% of gemifloxacin-treated mice were clear of pulmonary bacteria compared with only 0%-20% for levofloxacin. For levofloxacin-treated mice, 2 of 7 (29%) isolates with a levofloxacin minimum inhibitory concentration (MIC) 4 times that of the infecting parent strain had ParC mutations. By contrast, no isolates recovered from gemifloxacin-treated mice were reduced in susceptibility. Gemifloxacin could be effective in shortening duration of therapy for CAP treatment as well as minimize resistance development.
Assuntos
Fluoroquinolonas/uso terapêutico , Naftiridinas/uso terapêutico , Pneumonia Pneumocócica/tratamento farmacológico , Animais , Antibacterianos/farmacocinética , Antibacterianos/uso terapêutico , Área Sob a Curva , Temperatura Corporal/efeitos dos fármacos , Contagem de Colônia Microbiana , DNA Topoisomerase IV/genética , Modelos Animais de Doenças , Farmacorresistência Bacteriana/genética , Feminino , Fluoroquinolonas/farmacocinética , Gemifloxacina , Humanos , Levofloxacino , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos , Testes de Sensibilidade Microbiana , Mutação de Sentido Incorreto , Naftiridinas/farmacocinética , Ofloxacino/farmacocinética , Ofloxacino/uso terapêutico , Pneumonia Pneumocócica/mortalidade , Pneumonia Pneumocócica/fisiopatologia , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Análise de Sobrevida , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
The JB6 cell culture model is used to identify molecular determinants of susceptibility to the promotion of neoplastic transformation. Clonal variants susceptible to transformation ('P+' cells) form numerous anchorage-independent colonies in soft agar upon treatment with the phorbol ester tumor promoter TPA, whereas resistant variants ('P-' cells) do not. We now report that there is significantly less binding of activator protein-1 (AP-1) to its DNA binding site in P- cells than in P+ cells. Gel supershift assays were performed to detect association of all seven AP-1 family members with their DNA binding site in TPA-treated and -untreated P+ and P- cells. Significantly lower DNA binding and protein expression of JunD were detected in P- cells than in P+ cells. c-Jun was detected in P+, but not P-, AP-1-DNA complexes, and c-Fos was detected in P-, but not P+, AP-1-DNA complexes. These and other phenotype-specific differences in abundance and composition of AP-1-DNA complexes may play a role in the resistance of P- cells to tumor promoter-induced transformation.
Assuntos
DNA/metabolismo , Proteínas Proto-Oncogênicas c-jun/metabolismo , Fator de Transcrição AP-1/metabolismo , Sequência de Bases , Transformação Celular Neoplásica , Colagenases/genética , Primers do DNA , Humanos , Ligação Proteica , Proteínas Proto-Oncogênicas c-fos/metabolismoRESUMO
A number of reports have shown that PRL is an immune-stimulating hormone that is capable of stimulating organ-specific inflammatory disease in humans. More recently, hyperprolactinemia has been associated with the active phase of the immune-complex-mediated autoimmune disease, systemic lupus erythematosus. The theory that PRL contributes substantially to disease activity was upheld in the NZB/W mouse model of spontaneous, hormone-sensitive lupus. Implanted pituitary glands resulted in hyperprolactinemia, accelerated proteinuria, high levels of circulating IgG, and premature death. Therapeutic studies with NZB/W mice, as well as anecdotal evidence from a small number of patients, have provided evidence that PRL suppressive therapy may be beneficial in selected cases of autoimmune disease.
RESUMO
Carbon capture and storage (CCS) is a technological solution that can reduce the amount of carbon dioxide (CO2) emissions from the use of fossil fuel in power plants and other industries. A leading method today is amine based post-combustion capture, in which 2-aminoethanol (MEA) is one of the most studied absorption solvents. In this process, amines are released to the atmosphere through evaporation and entrainment from the CO2 absorber column. Modelling is a key instrument for simulating the atmospheric dispersion and chemical transformation of MEA, and for projections of ground-level air concentrations and deposition rates. In this study, the Weather Research and Forecasting model inline coupled with chemistry, WRF-Chem, was applied to quantify the impact of using a comprehensive MEA photo-oxidation sequence compared to using a simplified MEA scheme. Main discrepancies were found for iminoethanol (roughly doubled in the detailed scheme) and 2-nitro aminoethanol, short MEA-nitramine (reduced by factor of two in the detailed scheme). The study indicates that MEA emissions from a full-scale capture plant can modify regional background levels of isocyanic acid. Predicted atmospheric concentrations of isocyanic acid were however below the limit value of 1 ppbv for ambient exposure. The dependence of the formation of hazardous compounds in the OH-initiated oxidation of MEA on ambient level of nitrogen oxides (NOx) was studied in a scenario without NOx emissions from a refinery area in the vicinity of the capture plant. Hourly MEA-nitramine peak concentrations higher than 40 pg m(-3) did only occur when NOx mixing ratios were above 2 ppbv. Therefore, the spatial variability and temporal variability of levels of OH and NOx need to be taken into account in the health risk assessment. The health risk due to direct emissions of nitrosamines and nitramines from full-scale CO2 capture should be investigated in future studies.
Assuntos
Poluentes Atmosféricos/análise , Atmosfera/química , Monitoramento Ambiental/métodos , Etanolamina/análise , Modelos Químicos , Combustíveis Fósseis , Nitrosaminas , Centrais ElétricasRESUMO
Oxidative Heck couplings have been successfully developed for 2,2-disubstituted cyclopentene-1,3-diones. The direct coupling onto the 2,2-disubstituted cyclopentene-1,3-dione core provides a novel expedient way of enantioselectively desymmetrising all-carbon quaternary centres.
Assuntos
Ciclopentanos/química , Cetonas/química , Oxirredução , EstereoisomerismoRESUMO
The CYP3A4 enzyme contributes to the disposition of more than 60 therapeutically important drugs and displays marked person-to-person variability of the catalytic function. However, the extent of genetic contribution to variability in CYP3A4 activity remains elusive. Recently, we showed that a comparison of between- (SDb2) and within-person (SDW2) variances provides an estimate of the genetic component of variability in drug disposition. The aim of the present analysis was to assess the genetic control of CYP3A4 activity in vivo. A computerized literature search was conducted covering 1966 to September 1999 to identify studies reporting repeated administration of CYP3A4 substrates. The genetic contribution (rGC) to disposition of each CYP3A4 substrate was obtained by the formula (SDb2-SDW2)/SDb2. The rGC values approaching 1.0, point to overwhelming genetic control, whereas those close to zero suggest that environmental factors dominate. A total of 16 studies with 10 different CYP3A4 substrates were identified (n = 161 subjects). The rGC for hepatic CYP3A4 activity as measured by midazolam plasma clearance or the erythromycin breath test was 0.96 (0.92-0.98) (95% Cl) and 0.89 (0.65-0.98), respectively (P < 0.05). The point estimates of rGC for composite (hepatic + intestinal) CYP3A4 activity measured after oral administration of cyclosporine, ethinylestradiol, ethylmorphine, nifedipine and nitrendipine, ranged from 0.66-0.98 (median: 0.83) (P < 0.05). Cyclosporine data suggested a higher genetic control of CYP3A4 at night than during the day. These data indicate that further molecular genetic investigations are warranted to identify genetic variants at CYP3A4 or elsewhere in the genome which contribute to regulation of CYP3A4 activity.
Assuntos
Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Variação Genética/efeitos dos fármacos , Oxigenases de Função Mista/genética , Oxigenases de Função Mista/metabolismo , Preparações Farmacêuticas/administração & dosagem , Adolescente , Adulto , Idoso , Citocromo P-450 CYP3A , Esquema de Medicação , Tratamento Farmacológico/métodos , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Feminino , Humanos , Individualidade , MEDLINE , Masculino , Pessoa de Meia-Idade , Especificidade por Substrato/efeitos dos fármacos , Especificidade por Substrato/genéticaRESUMO
Eight normal subjects were given 250 mg intravenous phenytoin alone and with 3-day regimens of oral cimetidine, 400 mg at bedtime, 1200 mg a day, and 2400 mg a day in a randomized crossover fashion. Plasma samples for phenytoin and cimetidine, and urinary concentrations for phenytoin and 5-(4-hydroxyphenyl)-5-phenylhydantoin (HPPH) were measured by HPLC. All cimetidine regimens decreased phenytoin clearance, and there was no difference between the 400-mg bedtime dose and the 1200-mg a day regimens. There was, however, a difference between the 400-mg and 1200-mg and the 2400-mg regimens. There was no linear correlation between steady state cimetidine plasma concentrations and the decrease in phenytoin clearance. Urinary HPPH/phenytoin ratios decreased with all cimetidine treatments, but the differences were not significant. Phenytoin toxicity may result when cimetidine is added to existing regimens of this anticonvulsant.
Assuntos
Cimetidina/farmacologia , Guanidinas/farmacologia , Fenitoína/metabolismo , Adulto , Cromatografia Líquida de Alta Pressão , Cimetidina/administração & dosagem , Cimetidina/sangue , Relação Dose-Resposta a Droga , Avaliação de Medicamentos , Interações Medicamentosas , Humanos , Cinética , Masculino , Fenitoína/sangue , Fenitoína/urina , Distribuição AleatóriaRESUMO
The degree of interindividual and intraindividual variability in acetylator activity was investigated with caffeine used as a probe of enzyme activity. Acetylator phenotype and relative N-acetyltransferase activity were estimated in 46 subjects by measuring the urinary ratio of two metabolites, AFMU/1-MX, after a single 300 mg oral dose of caffeine on five separate occasions. Thirty homozygous slow (rr) and 15 heterozygous rapid (Rr) acetylators were identified. The degree of interindividual variability in acetylator activity was observed to be a mean of 32% (range 27% to 36%) and 20% (range 11% to 29%) in the rr and Rr groups, respectively. The mean intraindividual variation on repetitive measurement was 19% (range 6% to 49%) in the rr and 14% (range 7% to 24%) in the Rr acetylator group. Four subjects had apparent changes in acetylator activity with time such that they were unable to be assigned to any one acetylator group. Two of these four subjects exhibited apparent homozygous rapid acetylator activity intermittently during the 5-week trial. This variability may explain, in part, some of the high degree of patient variability observed in the toxicity, efficacy, and drug-related disease associated with acetylated drugs and environmental toxins.
Assuntos
Acetiltransferases/metabolismo , Cafeína/metabolismo , Fenótipo , Acetilação , Adulto , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Masculino , Fatores de Tempo , Uracila/análogos & derivados , Uracila/urina , Xantinas/urinaRESUMO
OBJECTIVES: The pharmacokinetic and pharmacodynamic interactions after 7 days of oral treatment with nisoldipine (10 mg twice daily) and propranolol (80 mg twice daily) were investigated in a partially randomized, placebo-controlled crossover study of 12 healthy volunteers. METHODS: At the end of each treatment period, pharmacokinetic parameters were measured, along with blood pressure, heart rate, cardiac function, systemic hemodynamics, plasma catecholamines, forearm blood flow, and apparent hepatic blood flow (estimated by the clearance of indocyanine green dye). RESULTS: After 7 days of treatment with nisoldipine and propranolol, neither drug altered the other's bioavailability or elimination parameters, and propranolol did not change the area under the plasma concentration-time curve of nisoldipine's metabolite, N-9425. Nisoldipine alone increased apparent hepatic blood flow and forearm blood flow compared with the other treatment groups but, with the addition of propranolol, both of these parameters were similar to those in the placebo group. Changes in the other hemodynamic parameters were consistent with the known effects of these drugs, and no differences in plasma catecholamine levels were detected. CONCLUSIONS: In contrast to the findings with single-dose treatment, administration of the combination of nisoldipine and propranolol for 7 days is not associated with any measurable kinetic interactions, although significant hemodynamic interactions do occur.
Assuntos
Hemodinâmica/efeitos dos fármacos , Nisoldipino/farmacologia , Propranolol/farmacologia , Adulto , Disponibilidade Biológica , Esquema de Medicação , Interações Medicamentosas , Humanos , Masculino , Nisoldipino/administração & dosagem , Nisoldipino/farmacocinética , Propranolol/administração & dosagem , Propranolol/farmacocinética , Valores de ReferênciaRESUMO
The brains of pathogen-free autoimmune MRL/lpr, NZBWF1 and NZB mice were examined for central nervous system (CNS) inflammation in premoribund 8-week-old animals and at ages when active systemic lupus erythematosus (SLE) was present. CNS inflammation was observed only in MRL/lpr mice. Immunohistochemical studies of brains from young MRL/lpr mice found that infiltrates were composed primarily of CD4+ cells. Older MRL/lpr mice (22 and 26 weeks of age) had CD4+ cells predominantly, but CD8+ and B220+ cells were also present. Perivascular leakage of IgG was a prominent and unexpected finding in the MRL/lpr model. Congenic MRL/+ mice with late-onset autoimmunity had no inflammatory cells in brain tissue, and there was no perivascular staining with IgG or albumin. Our findings suggest that MRL/lpr mice are a useful model for studies of lupus-associated CNS inflammatory disease, and perivascular leakage may be a primary mechanism for entry of IgG into the brain.
Assuntos
Encefalopatias/patologia , Lúpus Eritematoso Sistêmico/patologia , Neurite (Inflamação)/patologia , Animais , Encéfalo/imunologia , Encéfalo/metabolismo , Encéfalo/patologia , Encefalopatias/metabolismo , Antígenos CD4/análise , Imunoglobulina G/análise , Imuno-Histoquímica , Lúpus Eritematoso Sistêmico/metabolismo , Camundongos , Camundongos Mutantes , Neurite (Inflamação)/metabolismoRESUMO
F1 hybrid New Zealand Black (NZB) x New Zealand White (NZM) (NZB/NZW) mice spontaneously develop an autoimmune disease analogous to systemic lupus erythematosus (SLE). Testosterone experts a powerful suppressive effect on this disorder in adult NZB/NZW mice. A series of experiments was designed to determine if disease would also be suppressed by exposing fetal NZB/NZW mice to increased testosterone. A model was developed in which NZB dams carrying NZB/NZW fetuses were treated with testosterone in a dose adequate to masculinize the external genitalia in female fetuses. NZB/NZW mice that were derived from testosterone-treated dams and control NZB/NZW offspring were followed in a longevity study and had serial assays to assess development of SLE. Additional experiments were carried out to measure lymphocyte subsets and responses to mitogens. Results were compared with F1 hybrid offspring of C57BL/6 dams crossed with DBA/2 males, which are not autoimmune and do not develop SLE. Spleen cells from these groups were tested for Thy 1.2, CD4, CD8, and IgM receptors, and for responses to the mitogens Concanavalin A (ConA) and lipopolysaccharide. Control male NZB/NZW fetuses had unexpectedly high serum estradiol, which decreased significantly with maternal testosterone treatment. The testosterone-exposed male NZB/NZW fetuses developed into adults that lived longer than male NZB/NZW controls. Testosterone treatment of the dam was associated with elevated terminal anti-DNA levels but did not alter markers of renal diseases in adult NZB/NZW mice of either sex. Testosterone-exposed NZB/NZW females had altered T-lymphocyte subsets and testosterone-exposed males had increased response to ConA compared to controls. In male NZB/NZW fetuses whose mothers were administered testosterone, the naturally high level of circulating estradiol observed in untreated male fetuses was decreased significantly. This decrease was associated with an increase in longevity. This unique observation has important implications for fetal exposure to endocrine disruptors in the environment.
Assuntos
Doenças Autoimunes/embriologia , Doenças Autoimunes/prevenção & controle , Doenças Fetais/prevenção & controle , Cuidado Pré-Natal , Testosterona/uso terapêutico , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Doenças Autoimunes/diagnóstico , Feminino , Doenças Fetais/diagnóstico , Longevidade , Subpopulações de Linfócitos/patologia , Masculino , Camundongos , Camundongos Endogâmicos , Mitose , Valores de ReferênciaRESUMO
To evaluate effects of commonly used progestational estrogenic contraceptive steroids in a hormone-responsive model of lupus, we treated female NZB/W mice before clinical disease (6 wks of age) and after onset of lupus (24 wks of age) with doses of hormones titered to suppress reproduction. We report efficacy of norethindrone (NE) and norgestrel (NG), progestins derived from 19-nor-testosterone, in delaying expression of anti-DNA antibodies. Mice implanted with NG at 24 wks of age had prolonged lifespans. In contrast, the hydroxyprogesterone derivative, medroxyprogesterone acetate (MP), did not affect autoimmune disease. These observations suggest that prolonged administration of 19-nor-testosterone derivatives, in small doses adequate to suppress reproduction, may have ameliorative effects in systemic lupus erythematosus. Mice receiving ethinyl estradiol (EE) plus courses of tetracycline to suppress cystitis had active anti-DNA responses. In 60% of EE-treated mice, however, early deaths resulted from malignant lymphomas and complications of obstructive uropathy. Estrogen toxicity, rather than accelerated lupus, was the major cause of death in NZB/W mice treated with EE.
Assuntos
Anticoncepcionais Orais Hormonais/farmacologia , Lúpus Eritematoso Sistêmico/prevenção & controle , Animais , Anticorpos Antinucleares/sangue , Anticoncepcionais Orais Hormonais/toxicidade , Modelos Animais de Doenças , Etinilestradiol/toxicidade , Feminino , Longevidade/efeitos dos fármacos , Lúpus Eritematoso Sistêmico/etiologia , Lúpus Eritematoso Sistêmico/imunologia , Nefrite Lúpica/etiologia , Nefrite Lúpica/prevenção & controle , Acetato de Medroxiprogesterona/farmacologia , Camundongos , Camundongos Endogâmicos NZB , Noretindrona/farmacologia , Norgestrel/farmacologia , Fatores de Tempo , Sistema Urinário/efeitos dos fármacos , Sistema Urinário/patologiaRESUMO
BACKGROUND: Continuous refinement of the monoamine oxidase inhibitor (MAOI) diet has resulted in much reduced and simplified recommendations that attempt to balance safety and practicality. In the spirit of evidence-based practice, dietary restrictions should be based on carefully documented case reports and valid tyramine analyses. Residual concerns have focused on combination foods such as pizza and a variety of soy products. We determined the tyramine content of pizzas and a variety of soy products in order to refine dietary recommendations for use with MAOIs. METHOD: High-pressure liquid chromatography analysis of tyramine content was performed on a variety of pizzas, soy sauces, and other soybean products. A tyramine level of 6 mg or less was considered safe. RESULTS: No significant tyramine levels were found in any of the pizzas, including those with double pepperoni and double cheese. Marked variability was found in soy products, including clinically significant tyramine levels in tofu when stored for a week and high tyramine content in one of the soy sauces. CONCLUSION: Pizzas from large chain commercial outlets are safe for consumption with MAOIs. However, caution must be exercised if ordering pizzas from smaller outlets or gourmet pizzas known to contain aged cheeses. All soybean products should be avoided, especially soy sauce and tofu. Individualized counseling and continuous surveillance of compliance are still essential.