RESUMO
GDF15, a hormone acting on the brainstem, has been implicated in the nausea and vomiting of pregnancy, including its most severe form, hyperemesis gravidarum (HG), but a full mechanistic understanding is lacking1-4. Here we report that fetal production of GDF15 and maternal sensitivity to it both contribute substantially to the risk of HG. We confirmed that higher GDF15 levels in maternal blood are associated with vomiting in pregnancy and HG. Using mass spectrometry to detect a naturally labelled GDF15 variant, we demonstrate that the vast majority of GDF15 in the maternal plasma is derived from the feto-placental unit. By studying carriers of rare and common genetic variants, we found that low levels of GDF15 in the non-pregnant state increase the risk of developing HG. Conversely, women with ß-thalassaemia, a condition in which GDF15 levels are chronically high5, report very low levels of nausea and vomiting of pregnancy. In mice, the acute food intake response to a bolus of GDF15 is influenced bi-directionally by prior levels of circulating GDF15 in a manner suggesting that this system is susceptible to desensitization. Our findings support a putative causal role for fetally derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by prepregnancy exposure to the hormone, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.
Assuntos
Fator 15 de Diferenciação de Crescimento , Hiperêmese Gravídica , Náusea , Vômito , Animais , Feminino , Humanos , Camundongos , Gravidez , Talassemia beta/sangue , Talassemia beta/metabolismo , Feto/metabolismo , Fator 15 de Diferenciação de Crescimento/sangue , Fator 15 de Diferenciação de Crescimento/metabolismo , Hormônios/sangue , Hormônios/metabolismo , Hiperêmese Gravídica/complicações , Hiperêmese Gravídica/metabolismo , Hiperêmese Gravídica/prevenção & controle , Hiperêmese Gravídica/terapia , Náusea/sangue , Náusea/complicações , Náusea/metabolismo , Placenta/metabolismo , Vômito/sangue , Vômito/complicações , Vômito/metabolismoRESUMO
OBJECTIVES: The aim of the study was to assess the effect of tenofovir alafenamide (TAF) on kidney and bone biomarkers in patients who developed proximal renal tubulopathy (PRT) while receiving tenofovir disoproxil fumarate (TDF). METHODS: Individuals with a history of TDF-associated PRT and currently suppressed HIV infection on a tenofovir-sparing regimen were randomized 1:1 to continue current antiretroviral therapy or initiate emtricitabine (F)/TAF with discontinuation of nucleoside reverse transcriptase inhibitors (NRTIs) as appropriate. Renal and bone biomarkers were analysed at baseline, week 4 and week 12. The primary outcome was the mean difference between study arms in urine retinol-binding protein:creatinine ratio (RBPCR) change from baseline to week 12. Data were analysed using linear regression, with robust standard errors (primary outcome), and repeated measures mixed effects models (secondary outcomes). The trial was registered under European Union Drug Regulating Authorities Clinical Trials Database 2016-003345-29. RESULTS: We randomized 31 individuals [mean age 52.4 (standard deviation 0.3) years; 97% male; 90% white); all completed the study. At 12 weeks, there was no difference in change in RBPCR (ß 19.6; 95% confidence interval -35.3, 74.5; P = 0.47), and no difference in change in estimated glomerular filtration rate (eGFR) (based on creatinine or cystatin C), albuminuria, proteinuria, renal phosphate or urea handling, (fasting) urine osmolality, parathyroid hormone and bone turnover markers in the control versus the F/TAF exposed groups. No cases of PRT were observed. CONCLUSIONS: In people with a history of proximal renal tubulopathy while on TDF, 12-week exposure to TAF did not adversely affect renal tubular function. These data support continued evaluation of the long-term safety of TAF in this group of patients.
Assuntos
Adenina/análogos & derivados , Emtricitabina/administração & dosagem , Infecções por HIV/tratamento farmacológico , Nefropatias/prevenção & controle , Túbulos Renais Proximais/fisiologia , Adenina/administração & dosagem , Adenina/efeitos adversos , Adenina/farmacologia , Alanina , Creatinina/urina , Esquema de Medicação , Quimioterapia Combinada/efeitos adversos , Emtricitabina/efeitos adversos , Emtricitabina/farmacologia , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Infecções por HIV/urina , Humanos , Nefropatias/induzido quimicamente , Túbulos Renais Proximais/efeitos dos fármacos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Proteínas de Ligação ao Retinol/efeitos dos fármacos , Proteínas de Ligação ao Retinol/urina , Tenofovir/efeitos adversos , Resultado do Tratamento , Reino UnidoRESUMO
The objective of this study is to determine whether cannabis influences BDNF levels in patients with psychosis (FEP) and healthy volunteers (HV) to help understand the role of BDNF in psychosis. We assessed the association between BDNF and cannabis in a cohort of FEP antipsychotic-naïve patients and HV, whilst controlling for other potential confounding factors. 70 FEP drug-naive patients and 57 HV were recruited. A sociodemographic variable collection, structured clinical interview, weight and height measurement, substance use determination, and blood collection to determine BDNF levels by ELISA analysis were done. In FEP patients, cannabis use was associated with BDNF levels (high cannabis use was associated with lower BDNF levels). Moreover, cannabis use was statistically significantly associated with age (high use of cannabis was associated with younger age). In HV, no relationship between cannabis use and BDNF levels was observed. Otherwise, cannabis use was significantly associated with tobacco use, so that high cannabis users were also high tobacco users. This study showed a different association between cannabis use and BDNF levels in FEP patients compared with HV, particularly, with high doses of cannabis. These findings may help understand the deleterious effects of cannabis in some vulnerable individuals, as well as discrepancies in the literature.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Uso da Maconha/sangue , Transtornos Psicóticos/sangue , Adulto , Fatores Etários , Estudos de Coortes , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The objective was to determine whether metabolic goals have been achieved with locally isolated and transported preparations over the first 3 years of the UK's nationally funded integrated islet transplant program. Twenty islet recipients with C-peptide negative type 1 diabetes and recurrent severe hypoglycemia consented to the study, including standardized meal tolerance tests. Participants received a total of 35 infusions (seven recipients: single graft; 11 recipients: two grafts: two recipients: three grafts). Graft function was maintained in 80% at [median (interquartile range)] 24 (13.5-36) months postfirst transplant. Severe hypoglycemia was reduced from 20 (7-50) episodes/patient-year pretransplant to 0.3 (0-1.6) episodes/patient-year posttransplant (p < 0.001). Resolution of impaired hypoglycemia awareness was confirmed [pretransplant: Gold score 6 (5-7); 24 (13.5-36) months: 3 (1.5-4.5); p < 0.03]. Target HbA1c of <7.0% was attained/maintained in 70% of recipients [pretransplant: 8.0 (7.0-9.6)%; 24 (13.5-36) months: 6.2 (5.7-8.4)%; p < 0.001], with 60% reduction in insulin dose [pretransplant: 0.51 (0.41-0.62) units/kg; 24 (13.5-36) months: 0.20 (0-0.37) units/kg; p < 0.001]. Metabolic outcomes were comparable 12 months posttransplant in those receiving transported versus only locally isolated islets [12 month stimulated C-peptide: transported 788 (114-1764) pmol/L (n = 9); locally isolated 407 (126-830) pmol/L (n = 11); p = 0.32]. Metabolic goals have been attained within the equitably available, fully integrated UK islet transplant program with both transported and locally isolated preparations.
Assuntos
Diabetes Mellitus Tipo 1/terapia , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/citologia , Adulto , Glicemia/metabolismo , Peptídeo C/metabolismo , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Hipoglicemia/prevenção & controle , Insulina/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento , Reino UnidoRESUMO
Human pregnancy is frequently accompanied by nausea and vomiting that may become severe and life-threatening, as in hyperemesis gravidarum (HG), the cause of which is unknown. Growth Differentiation Factor-15 (GDF15), a hormone known to act on the hindbrain to cause emesis, is highly expressed in the placenta and its levels in maternal blood rise rapidly in pregnancy. Variants in the maternal GDF15 gene are associated with HG. Here we report that fetal production of GDF15, and maternal sensitivity to it, both contribute substantially to the risk of HG. We found that the great majority of GDF15 in maternal circulation is derived from the feto-placental unit and that higher GDF15 levels in maternal blood are associated with vomiting and are further elevated in patients with HG. Conversely, we found that lower levels of GDF15 in the non-pregnant state predispose women to HG. A rare C211G variant in GDF15 which strongly predisposes mothers to HG, particularly when the fetus is wild-type, was found to markedly impair cellular secretion of GDF15 and associate with low circulating levels of GDF15 in the non-pregnant state. Consistent with this, two common GDF15 haplotypes which predispose to HG were associated with lower circulating levels outside pregnancy. The administration of a long-acting form of GDF15 to wild-type mice markedly reduced subsequent responses to an acute dose, establishing that desensitisation is a feature of this system. GDF15 levels are known to be highly and chronically elevated in patients with beta thalassemia. In women with this disorder, reports of symptoms of nausea or vomiting in pregnancy were strikingly diminished. Our findings support a causal role for fetal derived GDF15 in the nausea and vomiting of human pregnancy, with maternal sensitivity, at least partly determined by pre-pregnancy exposure to GDF15, being a major influence on its severity. They also suggest mechanism-based approaches to the treatment and prevention of HG.
RESUMO
AIMS: Obesity and insulin resistance have been linked to rising incidence and earlier onset of Type 1 diabetes. Inherited differences in insulin action might also influence the evolution of Type 1 diabetes.Our aim was to determine whether parental BMI and insulin resistance influences age of onset of Type 1 diabetes in their offspring. METHODS: BMI standard deviation score and age at diagnosis of Type 1 diabetes was examined in 227 children, and in 206 of these was compared with local matched control subjects. Non-diabetic parents of a subgroup of 80 children with Type 1 diabetes were recruited. Parental BMI was compared with local adult control subjects. The relationship between parental BMI, waist-hip ratio, homeostasis model assessment of insulin resistance (HOMA-IR), leptin and adiponectin levels and age at diagnosis of Type 1 diabetes in offspring was examined. RESULTS: We found no relationship between age at diagnosis of Type 1 diabetes in children and BMI standard deviation score (P = 0.5). Children with Type 1 diabetes and their parents were heavier than matched control subjects (mean BMI standard deviation score sd in children = 0.66 1.06 vs. 0.32 1.16 in control subjects, P = 0.002; mean parental BMI sd 27.7 0.4 vs. 25.5 0.4 kg /m2 in control subjects; P < 0.0001). Maternal HOMA-IR accounted for 20% of variation in age at diagnosis (P < 0.001) with increasing maternal insulin resistance associated with later age at diagnosis of Type 1 diabetes. CONCLUSIONS: Childrenwith Type 1 diabetes and their parents have an increased BMI at diagnosis.Maternal insulin resistance is associated with later onset of Type 1 diabetes in children.
Assuntos
Idade de Início , Índice de Massa Corporal , Diabetes Mellitus Tipo 1/genética , Resistência à Insulina/genética , Obesidade/genética , Adulto , Fatores Etários , Criança , Filho de Pais com Deficiência , Pré-Escolar , Diabetes Mellitus Tipo 1/fisiopatologia , Feminino , Predisposição Genética para Doença/genética , Humanos , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Mães , Obesidade/complicaçõesRESUMO
In modern agriculture there is a great demand for a rapid and objective screening method for stress resistance, because so far, the resistance of new cultivars is tested in time- and money consuming field experiments. Based on fluorescence ratios, and lifetime of fluorophores measured by fluorescence spectroscopy, we have postulated that an early discrimination of susceptible and resistant wheat cultivars to the leaf rust pathogen Puccinia triticina can be accomplished. As representative for leaf rust resistant and leaf rust susceptible wheat genotypes the cultivars Esket and Skalmeje, respectively, were chosen. Plants were grown under controlled environment conditions and inoculated with the leaf rust pathogen at the second-leaf-stage by single-droplet application. Fluorescence measurements were carried out from two to four days after inoculation (dai) by using a compact fibre-optic fluorescence spectrometer with nanosecond time-resolution. Experimental results indicated that UV laser-induced spectral characteristics as well as determination of fluorescence lifetime are suited to detect leaf rust two dai. For this purpose several ratios and wavelength can be considered. In general, the tested cultivars showed distinct responses to the pathogen development. In this context the ratio F451/F687 measured three dai and mean lifetimes at 500 nm and 530 nm are suited to differentiate the resistant Esket from the susceptible Skalmeje genotypes.
Assuntos
Basidiomycota/fisiologia , Fluorescência , Doenças das Plantas/microbiologia , Triticum/genética , Interações Hospedeiro-Patógeno , Imunidade Inata , Lasers , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Triticum/crescimento & desenvolvimento , Triticum/microbiologiaRESUMO
CONTEXT: Bone mineral density (BMD) is positively associated with body weight. This association persists even at non-load bearing sites, suggesting that a nonmechanical factor such as an adipocyte-derived hormone may modulate BMD. OBJECTIVE: The objective of the study was to evaluate the relationship between adiponectin, an adipocyte-derived hormone, and BMD. DESIGN, SETTING, PARTICIPANTS: A total of 1735 nondiabetic women were recruited from a large, population-based cohort (mean age, 50.0 yr). We employed linear regression methods to estimate the relationship between adiponectin and BMD. MAIN OUTCOME MEASURES: Percentage change in BMD (as measured at total hip, spine, femoral neck, and forearm) and markers of bone turnover associated with a doubling of fasting serum adiponectin levels were measured. RESULTS: Employing age-adjusted analysis, each doubling of serum adiponectin was associated with a mean 2.7% decrease in BMD [total hip, -3.2% (95% confidence interval, -4.1, -2.3); femoral neck, -3.1% (-4.0, -2.1); forearm, -2.0 (-2.6, -1.4); spine, -2.6 (-3.5, -1.7)]. After adjustment for potential confounding factors, including BMI, serum leptin, central fat mass, hormone replacement therapy, smoking, and exercise, this relationship persisted, although decreased in magnitude. When stratified by menopausal status, the relationship between serum adiponectin and BMD strengthened in postmenopausal women but disappeared in premenopausal women. Serum adiponectin was positively associated with serum osteocalcin but not with urine deoxypyridinoline. CONCLUSIONS: After adjustment of measures of body fat, increasing levels of adiponectin were associated with a decrease in BMD, even at non-load bearing sites. These data suggest that adiponectin, an adipocyte-derived hormone, may play a role in bone metabolism through nonmechanical mechanisms and that this effect may be mediated by menopausal status.
Assuntos
Adiponectina/sangue , Densidade Óssea , Adipócitos/fisiologia , Tecido Adiposo/anatomia & histologia , Osso e Ossos/metabolismo , Estudos de Coortes , Feminino , Humanos , Pessoa de Meia-Idade , Valores de Referência , Análise de RegressãoAssuntos
Neuropeptídeos/sangue , Esquizofrenia/sangue , Adolescente , Adulto , Transtorno Bipolar/sangue , Glicemia/fisiologia , Peptídeo C/sangue , Cromogranina A/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Insulina/sangue , Masculino , Proinsulina/sangue , Estudos Retrospectivos , Adulto JovemRESUMO
Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5-30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI.
Assuntos
Imageamento por Ressonância Magnética , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Biomarcadores Tumorais/metabolismo , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Probabilidade , Estudos Prospectivos , Próstata/patologia , Reprodutibilidade dos TestesRESUMO
Fluorescence excitation transfer immunoassay is a suitable technique for the measurement of serum IgG and CRP. The reagents, once reconstituted, are stable for at least 3 months. The method shows no interference due to bilirubin, lipaemia or haemolysis up to high levels. The assay is simple to perform, reliable and offers considerable advantages over manual techniques such as radial immunodiffusion or electroimmunoassay.
Assuntos
Proteína C-Reativa/análise , Imunofluorescência/normas , Imunoglobulina G/análise , Hemólise , Humanos , Imunoglobulina A/análise , Imunoglobulina M/análise , Nefropatias/sangue , Hepatopatias/sangue , Kit de Reagentes para Diagnóstico/normas , Espectrometria de FluorescênciaRESUMO
UNLABELLED: OBJECTIVE-To characterize healing of corneal epithelial defects in horses and to evaluate the ability of epidermal growth factor (EGF) to modulate rate of corneal epithelial healing in horses. SAMPLE POPULATION: 20 eyes in 12 adult horses. PROCEDURE: Corneal epithelial wounds were created by mechanically debriding the limbus. Corneal healing was recorded for 3 treatment groups: 50 microg of EGF/ml (n = 5 eyes), 5 microg of EGF/ml (7), and PBS solution (8). Corneal healing was recorded once daily after instillation of fluorescein stain by use of photography and calculating the area of the wound, using imaging software. RESULTS: After corneal debridement, re-epithelialization was rapid and progressed in a linear fashion for the first 5 to 7 days after surgery in all groups. After that period, rates of healing decreased. A profound increase in the degree of inflammation, neovascularization, melanosis, and scarring was observed in eyes treated with the high dose of EGF (50 microg/ml), but there was not a statistical difference in mean healing time or in mean decrease in radius during the linear phase between the control and either EGF treatment groups. However, for all 8 horses in which both eyes were debrided, the first eye healed significantly faster than the second eye, regardless of treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Beneficial effects of topical administration of a high dose of EGF for acceleration of healing of corneal defects in eyes of horses are outweighed by the intensity of the associated inflammatory response.
Assuntos
Doenças da Córnea/veterinária , Fator de Crescimento Epidérmico/uso terapêutico , Epitélio Corneano/lesões , Doenças dos Cavalos/tratamento farmacológico , Cicatrização/efeitos dos fármacos , Administração Tópica , Animais , Doenças da Córnea/tratamento farmacológico , Fator de Crescimento Epidérmico/administração & dosagem , Fator de Crescimento Epidérmico/efeitos adversos , Células Epiteliais/efeitos dos fármacos , Feminino , Cavalos , Humanos , Inflamação/induzido quimicamente , MasculinoRESUMO
The U.S. Environmental Protection Agency's National Ambient Air Quality Standards for ozone and particulate matter (PM) require urban non-attainment areas to implement pollution-reduction strategies for anthropogenic source emissions. The type of fuel shown to decrease combustion emissions components versus traditional diesel fuel, is the diesel emulsion. The Lubrizol Corporation, in conjunction with Lovelace Respiratory Research Institute and several subcontracting laboratories, recently conducted a health assessment of the combustion emissions of PuriNOx diesel fuel emulsion (diesel-water-methanol) in rodents. Combustion emissions from either of two, 2002 model Cummins 5.9L ISB engines, were diluted with charcoal-filtered air to exposure concentrations of 125, 250 and 500 microg total PM/m3. The engines were operated on a continuous, repeating, heavy-duty certification cycle (U.S. Code of Federal Regulations, Title 40, Chapter I) using Rotella-T 15W-40 engine oil. Nitrogen oxide (NO) and PM were reduced when engines were operated on PuriNOx versus California Air Resources Board diesel fuel under these conditions. Male and female F344 rats were housed in Hazleton H2000 exposure chambers and exposed to exhaust atmospheres 6 h/day, five days/week for the first 11 weeks and seven days/week thereafter. Exposures ranged from 61 to 73 days depending on the treatment group. Indicators of general toxicity (body weight, organ weight, clinical pathology and histopathology), neurotoxicity (glial fibrillary acidic protein assay), genotoxicity (Ames assay, micronucleus, sister chromatid exchange), and reproduction and development were measured. Overall, effects observed were mild. Emulsion combustion emissions were not associated with neurotoxicity, reproductive/developmental toxicity, or in vivo genotoxicity. Small decreases in serum cholesterol in the 500-microg/m3 exposure group were observed. PM accumulation within alveolar macrophages was evident in all exposure groups. The latter findings are consistent with normal physiological responses to particle inhalation. Other statistically significant effects were present in some measured parameters of other exposed groups, but were not clearly attributed to emissions exposure. Positive mutagenic responses in several strains of Salmonella typhimurium were observed subsequent to treatment with emulsion emissions subfractions. Based on the cholesterol results, it can be concluded that the 250-microg/m3 exposure level was the no observed effect level. In general, biological findings in exposed rats and bacteria were consistent with exposure to petroleum diesel exhaust in the F344 rat and Ames assays.
Assuntos
Poluentes Atmosféricos/toxicidade , Emulsões , Gasolina , Metanol , Ratos Endogâmicos F344/fisiologia , Emissões de Veículos/toxicidade , Água/química , Administração por Inalação , Animais , Câmaras de Exposição Atmosférica , Bioensaio , Análise Química do Sangue , Peso Corporal , Emulsões/química , Emulsões/toxicidade , Feminino , Exposição por Inalação , Masculino , Testes para Micronúcleos , Óxidos de Nitrogênio/toxicidade , Material Particulado/toxicidade , RatosRESUMO
Anderson-Fabry disease (referred to as Fabry disease) is an X-linked disorder characterized by a deficiency of the lysosomal enzyme alpha-galactosidase A and the subsequent accumulation in various tissues of globotriaosylceramide (Gb(3)), the main substrate of the defective enzyme. Enzyme replacement therapy (ERT) offers a specific treatment for patients with Fabry disease, though monitoring of treatment is hampered by a lack of surrogate markers of response. In this study, the efficacy of long-term ERT in six Fabry hemizygotes and two symptomatic heterozygotes has been evaluated. Patients were administered recombinant alpha-galactosidase A every 2 weeks for up to a year. The efficacy of ERT was assessed by monitoring symptomatology and renal function. Urinary glycolipid concentration was estimated by a novel tandem mass spectrometric method. Urine glycolipid (Gb(3)) was elevated at baseline and fell impressively on ERT where patients were hemizygotes and in the absence of renal transplantation. In heterozygotes and in a recipient of a renal allograft, elevations and changes in urine glycolipids were less pronounced. In one patient, after several months of ERT, there was a transient increase in Gb(3) concentrations to baseline (pre-ERT) levels, associated with the presence of antibodies to the recombinant alpha-galactosidase A. The marked decline in urine Gb(3) on ERT, and its subsequent increase in association with an inhibitory antibody response, suggest that this analyte deserves further investigation as a potential marker of disease severity and response to treatment.
Assuntos
Doença de Fabry/terapia , Triexosilceramidas/urina , Adulto , Biomarcadores , Análise Mutacional de DNA , Doença de Fabry/enzimologia , Feminino , Glicolipídeos/metabolismo , Heterozigoto , Humanos , Imunoensaio , Isoenzimas/uso terapêutico , Transplante de Rim , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Modelos Químicos , Dor , Proteínas Recombinantes , Espectrometria de Massas por Ionização por Electrospray , Inquéritos e Questionários , Fatores de Tempo , alfa-Galactosidase/química , alfa-Galactosidase/uso terapêuticoRESUMO
The U.S. Environmental Protection Agency (EPA) National Ambient Air Quality Standards for ozone and particulate matter are requiring urban nonattainment areas to implement pollution-reduction strategies for anthropogenic source emissions. A type of fuel shown to decrease combustion emissions components versus traditional diesel fuels is the diesel-water emulsion. The Lubrizol Corporation in conjunction with Lovelace Respiratory Research Institute and several subcontracting laboratories recently conducted a rodent health assessment of inhaled combustion emissions of PuriNO(x) diesel fuel emulsion. Combustion emissions from either of two 2001 model Cummins 5.9-L ISB engines were diluted with charcoal-filtered air to exposure concentrations of 100, 200, and 400 microg total particulate matter/m(3). The engines were operated on a continuously repeating, heavy-duty certification cycle (U.S. Code of Federal Regulations, Title 40, Chapter I) using Rotella-T 15W-40 engine oil. Nitrogen oxide and particulate matter were reduced when engines were operated on PuriNO(x) versus California Air Resources Board diesel fuel under these conditions. Male and female F344 rats were housed in Hazleton H2000 exposure chambers and exposed to exhaust atmospheres 6 h/day, 5 days/wk for the first 11 wk and 7 days/wk threafter. Exposures ranged from 58 to 70 days, depending on the treatment group. Indicators of general toxicity (body weight, organ weight, clinical pathology, and histopathology), neurotoxicity (glial fibrillary acidic protein assay), genotoxicity (Ames assay, micronucleus, sister chromatid exchange), and reproduction and development were measured. Overall, effects observed were mild. Emulsion combustion emissions were not associated with neurotoxicity, reproductive/developmental toxicity, or in vivo genotoxicity. Small decreases in serum cholesterol and small increases in platelet values in some groups of exposed animals were observed. Particulate matter accumulation within alveolar macrophages was evident in all exposure groups. These findings are consistent with normal physiological responses to particle inhalation. Other statistically significant effects were present in some measured parameters of other exposed groups but were not clearly attributed to emissions exposure. Positive mutagenic responses in several strains of Salmonella typhimurium were observed subsequent to treatment with emulsion emissions subfractions. Based on the cholesterol and platelet results, it can be concluded that the 100 microg/m(3) exposure level was the no-observed-effect level. In general, biological findings in diesel emulsion emission-exposed animals and bacteria were consistent with exposure to petroleum diesel exhaust in the F344 rat and Ames assays.
Assuntos
Poluentes Atmosféricos/toxicidade , Emulsões , Gasolina , Emissões de Veículos/toxicidade , Água/química , Administração por Inalação , Animais , Bioensaio , Análise Química do Sangue , Peso Corporal , Emulsões/química , Emulsões/toxicidade , Feminino , Humanos , Exposição por Inalação , Pulmão/citologia , Pulmão/patologia , Masculino , Testes para Micronúcleos , Ratos , Ratos Endogâmicos F344RESUMO
There is increasing interest in diesel fuels derived from plant oils or animal fats ("biodiesel"), but little information on the toxicity of biodiesel emissions other than bacterial mutagenicity. F344 rats were exposed by inhalation 6 h/day, 5 days/wk for 13 wk to 1 of 3 dilutions of emissions from a diesel engine burning 100% soybean oil-derived fuel, or to clean air as controls. Whole emissions were diluted to nominal NO(x) concentrations of 5, 25, or 50 ppm, corresponding to approximately 0.04, 0.2, and 0.5 mg particles/m(3), respectively. Biologically significant, exposure-related effects were limited to the lung, were greater in females than in males, and were observed primarily at the highest exposure level. There was a dose-related increase in the numbers of alveolar macrophages and the numbers of particles in the macrophages, as expected from repeated exposure, but no neutrophil response even at the highest exposure level. The macrophage response was reduced 28 days after cessation of the exposure. Among the high-level females, the group mean lung weight/body weight ratio was increased, and minimal, multifocal bronchiolar metaplasia of alveolar ducts was observed in 4 of 30 rats. Lung weights were not significantly increased, and metaplasia of the alveolar ducts was not observed in males. An increase in particle-laden macrophages was the only exposure-related finding in lungs at the intermediate and low levels, with fewer macrophages and fewer particles per macrophage at the low level. Alveolar histiocytosis was observed in a few rats in both exposed and control groups. There were statistically significant, but minor and not consistently exposure-related, differences in body weight, nonpulmonary organ weights, serum chemistry, and glial fibrillary acidic protein in the brain. There were no significant exposure-related effects on survival, clinical signs, feed consumption, ocular toxicity, hematology, neurohistology, micronuclei in bone marrow, sister chromatid exchanges in peripheral blood lymphocytes, fertility, reproductive toxicity, or teratology. This study demonstrated modest adverse effects at the highest exposure level, and none other than the expected physiological macrophage response to repeated particle exposure at the intermediate level.