RESUMO
Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO2) emitted by human activities each year1, yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO2 (refs. 2,3). Although plant biomass often increases in elevated CO2 (eCO2) experiments4-6, SOC has been observed to increase, remain unchanged or even decline7. The mechanisms that drive this variation across experiments remain poorly understood, creating uncertainty in climate projections8,9. Here we synthesized data from 108 eCO2 experiments and found that the effect of eCO2 on SOC stocks is best explained by a negative relationship with plant biomass: when plant biomass is strongly stimulated by eCO2, SOC storage declines; conversely, when biomass is weakly stimulated, SOC storage increases. This trade-off appears to be related to plant nutrient acquisition, in which plants increase their biomass by mining the soil for nutrients, which decreases SOC storage. We found that, overall, SOC stocks increase with eCO2 in grasslands (8 ± 2 per cent) but not in forests (0 ± 2 per cent), even though plant biomass in grasslands increase less (9 ± 3 per cent) than in forests (23 ± 2 per cent). Ecosystem models do not reproduce this trade-off, which implies that projections of SOC may need to be revised.
Assuntos
Dióxido de Carbono/metabolismo , Sequestro de Carbono , Plantas/metabolismo , Solo/química , Biomassa , Pradaria , Modelos BiológicosRESUMO
AIM: To determine low-density lipoprotein cholesterol (LDL-C) screening frequency and levels, and factors associated with elevated LDL-C, in Australasian youth with type 1 diabetes (T1D). METHODS: Data were extracted from the Australasian Diabetes Data Network (ADDN), a prospective clinical quality registry, on all T1D healthcare visits attended by young people aged 16-25 years (with T1D duration of >1 year) between January 2011 and December 2020. The primary outcomes were elevated LDL-C > 2.6 mmol/L (100 mg/dL) and threshold for treatment: >3.4 mmol/L (130 mg/dL), according to consensus guidelines. Multivariable Generalised Estimated Equations (GEE) were used to examine factors associated with elevated LDL-C across all visits. RESULTS: A cohort of 6338 young people (52.6% men) were identified, of whom 1603 (25.3%) had ≥1 LDL-C measurement documented. At last measurement, mean age, age at T1D diagnosis and T1D duration were 18.3 ± 2.4, 8.8 ± 4.5 and 8.9 ± 4.8 years, respectively. LDL-C was elevated in 737 (46.0%) and at the treatment threshold in 250 (15.6%). In multivariable GEE elevated LDL-C continuously was associated with older age (OR = 0.07; 0.01-0.13, p = 0.02), female sex (OR = 0.31; 0.18-0.43; p < 0.001), higher HbA1c (OR = 0.04; 0.01-0.08; p = 0.01) and having an elevated BMI (OR = 0.17, 0.06-0.39, p < 0.001). CONCLUSIONS: LDL-C screening and levels are suboptimal in this cohort, increasing future cardiovascular complication risk. There is an urgent need to understand how healthcare services can support improved screening and management of dyslipidaemia in this population.
Assuntos
Doenças Cardiovasculares , Diabetes Mellitus Tipo 1 , Dislipidemias , Masculino , Humanos , Adolescente , Feminino , Adulto Jovem , Diabetes Mellitus Tipo 1/tratamento farmacológico , LDL-Colesterol , Estudos Prospectivos , Dislipidemias/epidemiologia , Dislipidemias/tratamento farmacológico , Doenças Cardiovasculares/epidemiologiaRESUMO
AIM: To measure skin autofluorescence in youth (<18 y.o.) and adults (≥18 y.o.) and to assess its relationship with type 1 diabetes, chronic complications and smoking. METHODS: In a cross-sectional study (n = 383) skin autofluorescence was measured in 269 people with type 1 diabetes (67 with vascular complications) and 114 people without diabetes, covering eight decades of age. Associations of skin autofluorescence with demographics and traditional risk factors were assessed. RESULTS: Skin autofluorescence increased with age in people with diabetes: for those with complications it increased by a mean ± se of 0.029 ± 0.003 arbitrary units per year (r = 0.76) and, for those without complications, it increased by 0.028 ± 0.002 arbitrary units (r = 0.77). These increases were higher than for people without diabetes, whose skin autofluorescence increased by 0.022 ± 0.002 arbitrary units (r = 0.78) per year (p = 0.004). Mean ±se age-adjusted skin autofluorescence was higher in people with diabetes complications vs people without diabetes complications (1.85 ± 0.04 vs 1.66 ± 0.02 arbitrary units) and people without diabetes (1.48 ± 0.03 arbitrary units; all P < 0.0001). Age-adjusted skin autofluorescence was higher in current smokers and recent ex-smokers vs non-smokers and longer-term ex-smokers (1.86 ± 0.06 vs 1.63 ± 0.02 arbitrary units; P = 0.0005). Skin autofluorescence area under the receiver-operating characteristic curve was 0.89 (95% CI 0.85-0.94) for retinopathy and 0.56 (95% CI 0.47-0.65) for nephropathy. CONCLUSIONS: Skin autofluorescence increases with age, but faster in people with diabetes, particularly in those with complications and in smokers, consistent with accelerated aging. Skin autofluorescence may facilitate complication screening and prediction. Longitudinal studies are merited.
Assuntos
Diabetes Mellitus Tipo 1/complicações , Fluorescência , Medições Luminescentes , Pele/metabolismo , Adulto , Estudos Transversais , Feminino , Produtos Finais de Glicação Avançada/metabolismo , Humanos , MasculinoRESUMO
AIM: To report, for the first time, the incidence and prevalence of childhood Type 1 diabetes in Turkey using a nationwide registry. METHODS: Information on birth date, city of birth, diagnosis date and gender of all patients with Type 1 diabetes aged < 18 years were obtained from the Turkish Social Security Institute for the period from January 2011 to December 2013. RESULTS: There were 17 175 prevalent cases of Type 1 diabetes over the 3-year period. The prevalence of Type 1 diabetes was 0.75/1 000 (95% CI 0.74-0.76) and was higher in girls than in boys (0.79 vs 0.72 /1 000; P < 0.01). There were 2465 incident cases in 2013. The incidence was slightly higher among girls (50.6%) than boys (49.4%); the girl:boy case ratio was 1.02. The incidence was 10.4/100 000 for boys and 11.3/100 000 for girls. The age-standardized incidence rate was 10.8 per 100 000 (95% CI 10.1-11.5) according to the WHO standard population, estimated using the direct method. The mean patient age at diagnosis was 10.6 ± 4.6 years. The highest proportion of cases (40.6%) was diagnosed in children aged 10-14 years. CONCLUSIONS: This is the first study to report the incidence and prevalence of Type 1 diabetes in children in Turkey. The incidence of Type 1 diabetes reflects the geographical location of Turkey, bridging Asia and Europe, with the incidence being higher than in Asia but lower than in Europe.
Assuntos
Desenvolvimento do Adolescente , Desenvolvimento Infantil , Diabetes Mellitus Tipo 1/epidemiologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/etnologia , Feminino , Humanos , Incidência , Lactente , Masculino , Prevalência , Sistema de Registros , Risco , Fatores Sexuais , Turquia/epidemiologiaRESUMO
AIM: To test the hypothesis that non-invasive skin autofluorescence, a measure of advanced glycation end products, would provide a surrogate measure of long-term glycaemia and be associated with early markers of microvascular complications in adolescents with Type 1 diabetes. METHODS: Forearm skin autofluorescence (arbitrary units) was measured in a cross-sectional study of 135 adolescents with Type 1 diabetes [mean ± sd age 15.6 ± 2.1 years, diabetes duration 8.7 ± 3.5 years, HbA1c 72 ± 16 mmol/mol (8.7 ± 1.5%)]. Retinopathy, assessed using seven-field stereoscopic fundal photography, was defined as ≥1 microaneurysm or haemorrhage. Cardiac autonomic function was measured by standard deviation of consecutive RR intervals on a 10-min continuous electrocardiogram recording, as a measure of heart rate variability. RESULTS: Skin autofluorescence was significantly associated with age (R2 = 0.15; P < 0.001). Age- and gender-adjusted skin autofluorescence was associated with concurrent HbA1c (R2 = 0.32; P < 0.001) and HbA1c over the previous 2.5-10 years (R2 = 0.34-0.43; P < 0.002). Age- and gender-adjusted mean skin autofluorescence was higher in adolescents with retinopathy vs those without retinopathy [mean 1.38 (95% CI 1.29, 1.48) vs 1.22 (95% CI 1.17, 1.26) arbitrary units; P = 0.002]. In multivariable analysis, retinopathy was significantly associated with skin autofluorescence, adjusted for duration (R2 = 0.19; P = 0.03). Cardiac autonomic dysfunction was also independently associated with skin autofluorescence (R2 = 0.11; P = 0.006). CONCLUSIONS: Higher skin autofluorescence is associated with retinopathy and cardiac autonomic dysfunction in adolescents with Type 1 diabetes. The relationship between skin autofluorescence and previous glycaemia may provide insight into metabolic memory. Longitudinal studies will determine the utility of skin autofluorescence as a non-invasive screening tool to predict future microvascular complications.
Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Angiopatias Diabéticas/diagnóstico por imagem , Retinopatia Diabética/diagnóstico por imagem , Microaneurisma/diagnóstico por imagem , Hemorragia Retiniana/diagnóstico por imagem , Pele/diagnóstico por imagem , Adolescente , Doenças do Sistema Nervoso Autônomo/etiologia , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/metabolismo , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/fisiopatologia , Retinopatia Diabética/etiologia , Retinopatia Diabética/fisiopatologia , Eletrocardiografia , Feminino , Fundo de Olho , Hemoglobinas Glicadas/metabolismo , Frequência Cardíaca , Humanos , Masculino , Microaneurisma/etiologia , Microaneurisma/fisiopatologia , Análise Multivariada , Imagem Óptica , Hemorragia Retiniana/etiologia , Hemorragia Retiniana/fisiopatologia , Pele/irrigação sanguíneaRESUMO
BACKGROUND: Healthcare professional (HCP) time supporting insulin pump therapy (IPT) has not been documented, yet it is important in planning and allocating resources for effective care. AIM: This study aims to determine HCP time spent in IPT patient care to inform resource planning for optimal IPT delivery. METHODS: Twenty-four Australian adult IPT-experienced institutions (14 government funded, seven private, three both) collected data between April 2012 and January 2013 prospectively, including: patient demographics, HCP classification, purpose of HCP-patient interaction, interaction mode and HCP time with the patient. A subset of patients was tracked from pre-pump education until stable on IPT. RESULTS: Data on 2577 HCP-adult patient interactions (62% face-to-face, 29% remote, 9% administrative) were collected over 12.2 ± 6.4 weeks for 895 patients; age 35.4 ± 14.2 years; 67% female; 99% type 1 diabetes, representing 25% of all IPT patients of the institutions. Time (hours) spent on IPT interactions per centre per week were: nurses 5.4 ± 2.8, dietitians 0.4 ± 0.2 and doctors 1.0 ± 0.5. IPT starts accounted for 48% of IPT interaction time. The percentage of available diabetes clinic time spent on outpatient IPT interactions was 20.4%, 4.6% and 2.7% for nurses, dietitians and doctors respectively. Fifteen patients tracked from pre-pump to stabilisation over 11.8 ± 4.5 weeks, required a median (range) of 9.2 (3.0-20.9), 2.4 (0.5-6.0) and 1.8 (0.5-5.4) hours per patient from nurses, dietitians and doctors respectively. CONCLUSIONS: IPT patient care represents a substantial investment in HCP time, particularly for nurses. Funding models for IPT care need urgent review to ensure this now mainstream therapy integrates well into healthcare resources.
Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Pessoal de Saúde/normas , Sistemas de Infusão de Insulina/estatística & dados numéricos , Insulina/administração & dosagem , Padrões de Prática Médica/normas , Relações Profissional-Paciente , Adolescente , Adulto , Idoso , Austrália/epidemiologia , Diabetes Mellitus Tipo 1/epidemiologia , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Masculino , Pessoa de Meia-Idade , Morbidade/tendências , Estudos Prospectivos , Adulto JovemRESUMO
AIMS: To review the incidence and evidence for screening for thyroid autoimmunity and thyroid dysfunction in Type 1 diabetes. METHODS: Systematic review and meta-analysis. Inclusion criteria were prospective cohort studies screening for thyroid autoimmunity and/or dysfunction (defined as an abnormal thyroid-stimulating hormone level) in Type 1 diabetes. Exclusion criteria included pregnancy and thyroid dysfunction before diabetes onset. Outcomes examined were: incidence of thyroid autoimmunity and/or dysfunction; association between thyroid autoimmunity and dysfunction; and cost-effectiveness. Data sources were MEDLINE, EMBASE, the Cochrane Library, manual searching and contact with authors, with limitations to English language and human studies. Meta-analysis was performed using random effects models. RESULTS: We identified 14 eligible studies, involving 2972 young people and 789 adults with Type 1 diabetes. Follow-up ranged from 1-18 years. None of the studies were of good methodological quality (Newcastle Ottowa Scale score > 7). The incidence of thyroid dysfunction (11 studies) ranged from 27 (95% CI 15-45) to 246 (95% CI 118-453) per 10 000 patient-years and thyroid autoimmunity (four studies) from 13 (95% CI 0.3-71) to 326 (95% CI 194-510). The risk of thyroid dysfunction was higher in those with thyroid autoimmunity: summary risk ratio 25 (95% CI 9-71) and was higher in children (49, 95% CI 16-150) compared with adults (7, 95% CI 3-13). No studies examined cost-effectiveness of screening. CONCLUSIONS: There is a markedly increased risk of thyroid dysfunction in people with Type 1 diabetes and thyroid autoimmunity. The optimal method or frequency of screening could not be determined from available data. Future studies should examine whether screening improves clinical outcomes in this population.
Assuntos
Diabetes Mellitus Tipo 1/complicações , Tireoidite Autoimune/complicações , Adulto , Autoimunidade , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/fisiopatologia , Feminino , Humanos , Incidência , Gravidez , Doenças da Glândula Tireoide/complicações , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/epidemiologia , Glândula Tireoide/imunologia , Glândula Tireoide/fisiopatologia , Tireoidite Autoimune/diagnóstico , Tireoidite Autoimune/epidemiologiaRESUMO
AIMS: To examine temporal trends in anthropometry in children with Type 1 diabetes from Sydney, Australia. METHODS: We conducted a retrospective study in a total of 1975 children with Type 1 diabetes, aged <16 years, between 1990 and 2009. Trends in height, weight and BMI standard deviation score after initial stabilization were examined by age group (<5 years, 5 to <10 years, 10 to 16 years) and time period of diagnosis (T1: 1990-1994, T2: 1995-1999; T3: 2000-2004 and T4: 2005-2009). Factors associated with BMI standard deviation score (time period, age group, gender and socio-economic status) were examined using multivariable linear regression. RESULTS: The mean BMI standard deviation score (±sd) increased between T1 and T2 (0.54 ± 1.14 vs 0.81 ± 1.14, P = 0.002), but remained steady thereafter (T3: 0.85 ± 1.11, T4: 0.87 ± 1.09; T2 to T4: P = 0.40). Similarly, the prevalence of overweight and obesity increased from T1 to T2 (26 to 35%, P = 0.01), but was unchanged thereafter (T3: 34%, T4: 34%; T2 to T4: P = 0.90). On multivariable regression analysis, a higher BMI standard deviation score was associated with younger age (≥5 years vs <5 years, ß=-0.40, 95% CI -0.51 to -0.28, P < 0.001), later time period (T2 to T4 vs T1, ß=0.30, 95% CI 0.16-0.45, P < 0.001) and male gender (ß=0.25, 95% CI 0.15-0.34, P < 0.001). CONCLUSION: The prevalence of overweight and obesity has remained unchanged in children at diagnosis of Type 1 diabetes over 15 years. These findings suggest that higher adiposity alone cannot account for the continued rising incidence of Type 1 diabetes in recent years.
Assuntos
Adiposidade/fisiologia , Diabetes Mellitus Tipo 1/epidemiologia , Adolescente , Distribuição por Idade , Idade de Início , Índice de Massa Corporal , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/fisiopatologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , New South Wales/epidemiologia , Sobrepeso/epidemiologia , Sobrepeso/fisiopatologia , Estudos Retrospectivos , Distribuição por Sexo , Fatores SocioeconômicosRESUMO
AIM: Diabetic ketoacidosis is a life-threatening complication of Type 1 diabetes. Blood ß-hydroxybutyrate testing is now widely available as an alternative to urine acetoacetate testing for detecting ketosis. The aim of this study was to review the effectiveness of capillary or serum ß-hydroxybutyrate compared with urine acetoacetate testing in prevention and management of diabetic ketoacidosis. METHODS: MEDLINE, EMBASE, EBM Reviews, The Cochrane Library and CINAHL (until April 2012, no language restrictions, studies in humans) were searched for experimental and observational studies comparing the effectiveness of blood ß-hydroxybutyrate and urine acetoacetate testing. Outcomes examined were prevention of diabetic ketoacidosis, time to recovery from diabetic ketoacidosis, healthcare costs and patient or caregiver satisfaction. Additional sources included reference lists, conference proceedings and contact with experts in the field. RESULTS: Four studies (two randomized controlled trials and two cohort studies) met eligibility criteria, including 299 participants across 11 centres. Risk of bias was low to moderate. Blood ketone testing compared with urine testing was associated with reduced frequency of hospitalization (one study), reduced time to recovery from diabetic ketoacidosis (three studies), cost benefits (one study) and greater satisfaction (one study, intervention group only). No study assessed prevention of diabetic ketoacidosis. Meta-analysis could not be performed because of heterogeneity in study design and published data. CONCLUSIONS: There is evidence suggesting that blood ß-hydroxybutyrate testing is more effective than urine acetoacetate testing in reducing emergency department assessment, hospitalization and time to recovery from diabetic ketoacidosis, as well as potentially lowering healthcare expenditure. Further research in both young people and adults is needed.
Assuntos
Ácido 3-Hidroxibutírico/sangue , Acetoacetatos/urina , Diabetes Mellitus Tipo 1/complicações , Cetoacidose Diabética/prevenção & controle , Cetoacidose Diabética/terapia , Cuidados Críticos/economia , Estatura Cabeça-Cóccix , Cetoacidose Diabética/economia , Gastos em Saúde , Hospitalização/economia , Humanos , MEDLINE , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
AIMS: To determine the incidence of coeliac disease in young people with Type 1 diabetes and to examine the effect of age at diabetes onset and disease duration. METHODS: This was a clinic-based observational cohort study of 4379 people aged ≤ 18 years (49% male) between 1990 and 2009 from Sydney, Australia. Screening for coeliac disease was performed at diagnosis and 1-2 yearly using anti-endomysial and/or anti-tissue transglutaminase immunoglobulin A (IgA) antibodies. Coeliac disease was diagnosed by small bowel biopsy based on Marsh score ≥ III. RESULTS: Coeliac disease was confirmed by biopsy in 185; of these, 61 (33%) were endomysial or tissue transglutaminase IgA antibody-positive at diabetes diagnosis. Mean age at diabetes onset was 6.6 ± 4.0 vs. 8.4 ± 4.1 years in those without coeliac disease (P < 0.001). Mean incidence was 7.7 per 1000 person years (95% CI 6.6-8.9) over 20 years. Incidence was higher in children aged < 5 years at diabetes diagnosis (10.4 per 1000 person years) vs. ≥ 5 years (6.4 per 1000), incidence rate ratio 1.6 (95% CI 1.2-2.2, P = 0.002). Coeliac disease was diagnosed after 2, 5 and 10 years of diabetes in 45, 78 and 94% of cases, respectively. Median time to coeliac disease diagnosis was longer in children aged < 5 years at diabetes onset (3.3 years) compared with older children (0.7 years, P < 0.001). CONCLUSIONS: Coeliac disease is common in young people with Type 1 diabetes; the risk is greatest with diabetes onset < 5 years, but after longer diabetes duration. Screening for coeliac disease should be performed at diabetes diagnosis and for at least 10 years in young children.
Assuntos
Doença Celíaca/diagnóstico , Doença Celíaca/epidemiologia , Diabetes Mellitus Tipo 1/complicações , Adolescente , Fatores Etários , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Humanos , Incidência , Estudos Longitudinais , Masculino , New South Wales , Prevalência , Estudos Retrospectivos , Fatores de Risco , Fatores de TempoRESUMO
AIMS: To determine the national incidence of Type 1 diabetes in children aged 0-14 years and examine trends in incidence between 2000 and 2006 by age, sex and calendar year. METHODS: Case ascertainment was from the Australian National Diabetes Register, a prospective population-based incidence register established in 1999, with two sources of ascertainment: the National Diabetes Services Scheme and the Australasian Paediatric Endocrine Group's state-based registers. Denominator data were from the Australian Bureau of Statistics. RESULTS: There were 6350 new cases of Type 1 diabetes (3323 boys and 3027 girls). Case ascertainment was 97.1% complete using the capture-recapture method. The mean adjusted incidence rate for 2000-2006 was 21.6 per 100,000 person-years [95% confidence interval (CI) 21.0, 22.1], and increased from 19.8 in 2000 to 23.4 per 100,000 in 2006, an average increase of 2.8% (95% CI 1.5, 4.1) per year. Mean incidence for the 7-year period increased with age, and was significantly higher in boys aged 0-4 years and 10-14 years than in girls of the same age. CONCLUSIONS: The incidence of Type 1 diabetes among 0-14-year-olds in Australia is very high compared with available data from many other countries. The rate of increase observed globally in the last decade has continued well into this decade in Australia. The rising incidence cannot be explained by changes in genetic susceptibility; there is an urgent need to examine the environmental factors that have contributed to this increase. The findings of this study also have important implications for resource planning.
Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Adolescente , Distribuição por Idade , Austrália/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Distribuição por Sexo , Fatores de TempoRESUMO
AIM: To examine the trajectory of small artery elasticity (SAE) and pulse pressure (PP) in people with Type 1 diabetes and non-diabetic controls across the lifespan, and explore associations with microvascular complications (CX+). METHODS: This cross-sectional study included 477 Type 1 diabetes patients (188 with CX+, 289 without CX-) and 515 controls. Relationships between SAE and PP and age were evaluated using segmented linear regression. Logistic regression was used to assess the associations between microvascular complications (retinopathy and/or nephropathy) and SAE and PP. RESULTS: SAE peaked significantly later among controls than diabetic patients CX- vs. CX+ (21.2 vs. 20.4 vs. 17.6 years respectively, p < 0.001). In adults, mean SAE was significantly lower in CX+ vs. CX- vs. controls (6.8 vs. 7.8 vs. 8.0 ml/mm Hg × 10; p < 0.0001), and mean PP was significantly higher in CX+ vs CX- and controls (60 vs. 55 vs. 53 mm Hg; p < 0.0001). CONCLUSION: Type 1 diabetes CX+ subjects have an earlier peak and decline in SAE relative to CX- and controls, who did not differ. Lower SAE and higher PP were associated with increased odds of Type 1 diabetes complications in adults. These clinically applicable techniques demonstrate an association between accelerated vascular aging and vascular complications in diabetes.
Assuntos
Envelhecimento , Diabetes Mellitus Tipo 1/complicações , Angiopatias Diabéticas/fisiopatologia , Rigidez Vascular , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Estudos de Coortes , Estudos Transversais , Diabetes Mellitus Tipo 1/fisiopatologia , Angiopatias Diabéticas/epidemiologia , Progressão da Doença , Feminino , Humanos , Masculino , Microvasos/fisiopatologia , Pessoa de Meia-Idade , Análise de Onda de Pulso , Análise de Regressão , Risco , Vitória/epidemiologia , Adulto JovemRESUMO
The history of insecticide resistance in the horn fly, Haematobia irritans, and the relationship between the characteristics of horn fly biology and insecticide use on resistance development is discussed. Colonies of susceptible horn flies were selected for resistance with six insecticide treatment regimens: continuous single use of permethrin, diazinon and ivermectin: permethrin-diazinon (1:2) mixture; and permethrin-diazinon and permethrin-ivermectin rotation (4-month cycle). Under laboratory conditions, resistance developed during generations 21, 31 and 30 to permethrin, diazinon and ivermectin, respectively. The magnitude of resistance ranged from < 3-fold with ivermectin to 1470-fold with permethrin. Field studies demonstrated that use of a single class of insecticidal ear tag during the horn-fly season resulted in product failure within 3-4 years for pyrethroids and organophosphates, respectively. In laboratory studies, use of alternating insecticides or a mixture of insecticides delayed the onset of resistance for up to 12 generations and reduced the magnitude of pyrethroid resistance. In field studies, yearly alternated use of pyrethroids and organophosphates did not slow or reverse pyrethroid resistance (Barros et al., unpublished data), while a 2-year alternated use with organophosphates resulted in partial reversion of pyrethroid resistance. When pyrethroid and organophosphate ear tags were used in a mosaic strategy at two different locations, efficacy of products did not change during a 3-year period.
Assuntos
Resistência a Inseticidas , Inseticidas/farmacologia , Muscidae/efeitos dos fármacos , Animais , Diazinon/farmacologia , Ivermectina/farmacologia , Permetrina , Piretrinas/farmacologiaRESUMO
Developing skin lesions on hairless guinea pigs due to 2,2'-dichlorodiethyl sulfide (sulfur mustard, HD) exposure were examined to determine the time course for the appearance of histopathologic markers in relationship to skin NAD+ and NADP+ content after HD exposure. Hairless guinea pig skin was exposed to HD for 8 min by means of a vapor cup. Skin punches were taken at 1, 2, 4, 8, 12, 16, 20 and 24 h after HD exposure. Intracellular edema (IE) appeared at 2 h and increased steadily over 24 h. Epidermal necrosis (EN) and pustular epidermatitis (PE) developed at 8 h and reached a maximum at 16 h. Follicular necrosis (FN) appeared at 8 h and increased up to 24 h. Microvesicles (MV) developed between 12-16 h reaching a maximum at 24 h. Niacinamide (750 mg/kg, ip) pretreatment (30-min) reduced the incidence of MV (40%) and FN (45%) at 24 h, but did not reduce IE, EN, or PE. In all animals, skin NAD+ content decreased to a minimum (20% of control) at 16 h, but NAD+ decreases did not precede microvesicle formation. Skin NADP+ content increased (260%) between 1-2 h and returned to control at 4 h. Skin cell NADP+ increases may be indicative of an early phase of cellular oxidative stress that may contribute to HD-induced dermal pathogenesis. Since NAD+ reductions did not precede microvesication and NAM-induced increases in NAD+ content did not delay or reduce early cellular alterations, the contributory role of NAD+ to microvesicle formation may be limited and other biochemical changes should be investigated.
Assuntos
Gás de Mostarda/toxicidade , Pele/efeitos dos fármacos , Animais , Vesícula/induzido quimicamente , Interações Medicamentosas , Cobaias , Masculino , NAD/metabolismo , NADP/metabolismo , Niacinamida/farmacologia , Pele/patologiaRESUMO
The possible presence of sand flies (Diptera: Psychodidae) among colonies of Gunnison's prairie dogs, Cynomys gunnisoni Baird, was investigated on or near ranches with histories of vesicular stomatitis (VS) in domestic livestock in the mid-Rio Grande River Valley, NM, and west-slope region of Colorado. Sampling was conducted at six locations, three in each region, using three methods: standard down-draft suction/light traps, up-draft suction/light traps (both supplemented with CO2), and burrow-emergence traps. Two male and four female sand flies, Lutzomyia apache, Young and Perkins were recovered from prairie dog colony and sand-sagebrush association habitats on a cattle ranch in Socorro County, NM. Sand flies were captured only in up-draft suction/light traps. This record is of interest for the following reasons: (1) sand flies have not been reported from the Rio Grande River Valley of New Mexico, (2) sand flies are biological vectors of VS viruses in other areas, (3) the mid-Rio Grande River Valley has been a focus of VS virus activity in domestic livestock during recent outbreaks, and (4) the source of vesicular stomatitis viruses that infect livestock in the western United States is unknown, but may involve introductions of virus from Mexico or an endemic cycle maintained by vector insects.
Assuntos
Psychodidae , Sciuridae/parasitologia , Animais , Bovinos , Colorado , Feminino , Masculino , New Mexico , Infecções por Rhabdoviridae , Estomatite , Vírus da Estomatite Vesicular IndianaRESUMO
OBJECTIVES: 1. To determine the incidence of type 1 (insulin dependent) diabetes in children aged 0-14 years who were resident in the state of New South Wales, Australia over the period 1992-1996. 2. To analyse the trends in incidence over the period 1990-1996. METHODS: Primary ascertainment of patients was performed using a prospective incidence register established in 1990. The secondary source of ascertainment was the National Diabetes Supply Scheme, a government subsidised scheme for diabetic supplies. RESULTS: There were 1,230 patients identified over the five-year period. Using the capture-recapture method, ascertainment was estimated to be 99% complete. The lowest incidence occurred in 1992 (16.9 per 10(5) person years) and the highest incidence was in 1995 (21.7 per 10(5)). The crude incidence of IDDM from 1990-1996 was 17.8 per 10(5) and there was a statistically significant rise in the incidence of type 1 diabetes over this period (p=0.0003). The annual incidence has increased on average by 3.2% per year since 1990. CONCLUSION: The incidence of childhood type 1 diabetes in NSW has increased significantly since 1990.
Assuntos
Diabetes Mellitus Tipo 1/epidemiologia , Adolescente , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , New South Wales/epidemiologia , Sistema de Registros , Estações do Ano , Fatores SexuaisRESUMO
Losses in livestock production due to ectoparasite infestations exceed $2.26 billion annually. Over 50 species of ectoparasites infest cattle throughout the United States. The horn fly, Haematobia irritans (L.), is the most important and widespread of the five to six major pest species of pastured cattle in the southern region. Results from the examination of production traits from cattle under ectoparasite burdens have been variable, ranging from no effect to significant reductions in weight gains. Because of this inconsistency, specific physiological and nutritional responses in cattle infested or not infested with horn flies have been examined. Data have shown significant differences in nitrogen retention, blood cortisol concentrations, vital signs, water consumption, and urine production. Implications are that total energy balance is altered when an animal is exposed to ectoparasite infestations, thereby resulting in decreased productivity.
Assuntos
Doenças dos Bovinos/fisiopatologia , Ectoparasitoses/veterinária , Muscidae , Animais , Bovinos , Doenças dos Bovinos/economia , Culicidae , Dípteros , Ectoparasitoses/economia , Ectoparasitoses/fisiopatologia , Infestações por Piolhos/economia , Infestações por Piolhos/fisiopatologia , Infestações por Piolhos/veterinária , Infestações por Carrapato/economia , Infestações por Carrapato/fisiopatologia , Infestações por Carrapato/veterinária , Estados UnidosRESUMO
This study investigated the relationship between responsibility attribution and tendency to report child sexual abuse among practicing psychologists. Two hundred ninety-five licensed psychologists from two states completed vignettes in which the sex of the child and the father's admission or denial of alleged sexual abuse were systematically manipulated. Subjects assigned relative percentages of responsibility to the father, mother, child, and society for the abuse and indicated their tendency to report and their level of confidence that abuse was occurring. Results indicated a significant effect for responsibility to the mother which varied as a function of the father's response to the allegation of abuse. Mothers were blamed significantly more for the abuse when the father denied being abusive. Responsibility attribution did not predict reporting, while confidence in the occurrence of abuse did. Also, sex differences were found among participants where male subjects assigned significantly more responsibility to the abusive father than female participants, and the females blamed the mother more than the males. Results are discussed in the context of previous research on responsibility attribution in child abuse.
Assuntos
Maus-Tratos Infantis/legislação & jurisprudência , Revelação , Ética Profissional , Atitude , Criança , Maus-Tratos Infantis/epidemiologia , Confidencialidade , Humanos , Incesto/legislação & jurisprudência , Jurisprudência , Delitos Sexuais/legislação & jurisprudência , Estados Unidos/epidemiologiaRESUMO
The in vivo metabolism of topically applied 14C-permethrin was determined for adults of pyrethroid-resistant and -susceptible horn flies, Haematobia irritans (L.) at 1, 2, and 6 h after treatment. At 1 and 2 h after treatment, resistant horn flies had significantly higher internal levels of radioactivity (permethrin plus metabolites) compared with adults of the susceptible strain. Analysis of the internal extracts by thin-layer chromatography indicated no differences in the levels of permethrin. However, significantly higher levels of metabolites that co-chromatograph with 3-(2'- or 4'-hydroxyphenoxy)benzyl (1RS) cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate at 1 and 2 h after treatment and (1RS) cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid at 1 h after treatment. These results demonstrate that an enhanced penetration and metabolism are present during the early phases of permethrin intoxication. Enhanced metabolism may contribute to the ability of resistant horn flies to survive in the presence of pyrethroids.
Assuntos
Inseticidas/metabolismo , Muscidae/metabolismo , Piretrinas/metabolismo , Animais , Bovinos , Resistência a Inseticidas , PermetrinaRESUMO
Attraction, engorgement, mortality, and fecundity were observed on host-seeking Aedes vexans and Psorophora confinnis given the opportunity to feed on insecticide-treated steers in stable traps. Individual steers were treated with Ectrin ear tags, Ectrin spray, Terminator ear tags, Saber ear tags, or Ivomec injection or were left untreated. Aedes vexans and Ps. confinnis accounted for over 98% of 20,738 mosquitoes collected. Relative attraction ranged from 0.45 with Saber ear tag to 0.84 with Terminator ear tag. Engorgement rates of mosquitoes from insecticide-treated steers ranged from 55 to 91%. Engorgement was reduced 18-45% by Terminator ear tag, Ectrin spray, and Saber ear tag treatments. Forty-eight percent mortality of unengorged Ae. vexans and 61% mortality of unengorged Ps. confinnis was observed at collection with the Saber ear tag treatment. Percentage of mortality of engorged mosquitoes of both species was generally much lower. Ivomec injection treatment showed the greatest effect on delayed (48-h) mortality of engorged mosquitoes, with 41 and 82% mortality for Ae. vexans and Ps. confinnis, respectively. No insecticide treatment had a significant effect on fecundity.