RESUMO
Increasing uterine artery blood flow (UABF) may benefit fetal growth restriction where impaired uteroplacental perfusion prevails. Based on previous short-term results, we examined the long-term effects of adenovirus vector-mediated overexpression of vascular endothelial growth factor-A(165) (VEGF-A(165)) in the uterine artery (UtA). Transit-time flow probes were implanted around both UtAs of mid-gestation pregnant sheep (n=11) to measure UABF. A carotid artery catheter was inserted to measure maternal or fetal hemodynamics. Baseline UABF was measured over 3 days, before injection of adenovirus vector (5 × 10(11) particles) encoding the VEGF-A(165) gene (Ad.VEGF-A(165)) into one UtA and a reporter ß-galactosidase gene (Ad.LacZ) contralaterally. UABF was then measured daily until term. At 4 weeks post injection, the increase in UABF was significantly higher in Ad.VEGF-A(165) compared with Ad.LacZ-transduced UtAs (36.53% vs 20.08%, P=0.02). There was no significant effect on maternal and fetal blood pressure. Organ bath studies showed significantly lesser vasoconstriction (E(max) 154.1 vs 184.7, P<0.001), whereas immunohistochemistry demonstrated a significantly increased number of adventitial blood vessels (140 vs 91, n=26, P<0.05) following Ad.VEGF-A(165) transduction. Local overexpression of VEGF-A(165) in the UtAs of pregnant mid-gestation sheep leads to a sustained long-term increase in UABF, which may be explained by neovascularization and altered vascular reactivity.
Assuntos
Prenhez , Artéria Uterina/metabolismo , Útero/irrigação sanguínea , Fator A de Crescimento do Endotélio Vascular/genética , Adenoviridae/genética , Animais , Pressão Arterial , Feminino , Retardo do Crescimento Fetal/fisiopatologia , Vetores Genéticos , Gravidez , Complicações na Gravidez , Fluxo Sanguíneo Regional , Ovinos , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
OBJECTIVE: To evaluate the use of second-trimester uterine artery (UtA) Doppler to predict adverse pregnancy outcome in women with extreme levels of fetoplacental proteins used for Down syndrome screening. METHODS: At a single institution, women screened for Down syndrome were offered second-trimester UtA Doppler examination if they had one of the following on analysis of maternal serum: pregnancy-associated plasma protein-A ≤ 0.28 multiples of the median (MoM) (1% of screened population), inhibin ≥ 3.0 MoM (2%), human chorionic gonadotropin ≥ 4.0 MoM (2%), alpha-fetoprotein (AFP) ≥ 2.5 MoM (2%), estriol ≤ 0.5 MoM (1%). Abnormal UtA Doppler was defined as bilateral or unilateral notching or mean pulsatility index ≥ 1.45. RESULTS: Of 240 women studied, 92 (38.3%) had an adverse pregnancy outcome: small for gestational age (either < 10(th) customized centile (SGA(10) ) or < 5(th) customized centile (SGA(5) )), low birth weight (LBW, < 2.5 kg), preterm delivery (< 37 + 0 weeks of gestation), fetal loss (late miscarriage or stillbirth), placental abruption and gestational hypertension. Of 167 women screened with all five hormones, those with two or more extreme levels (n = 18, 10.8%) were significantly at risk of adverse pregnancy outcome compared with those with only one marker (61.1% vs. 35.6%, P = 0.04). UtA Doppler was abnormal in 20% (32 of 159 women screened) and increased the risk of adverse pregnancy outcome (RR 2.5, 65.6% vs. 26.0%, P < 0.001). SGA(10) , SGA(5) and LBW were significantly more common in women with abnormal UtA Doppler (RR 2.98, 56.2% vs. 18.9%, P < 0.001, RR 4.6, 43.7% vs. 9.4%, P < 0.001 and RR 4.4, 31.2% vs. 7.1%, P < 0.001, respectively). Women with normal Doppler examination still had a 26% risk of adverse pregnancy outcome. CONCLUSIONS: In women with extreme levels of feto-placental proteins used for Down syndrome screening, an abnormal second-trimester UtA Doppler examination confers a high risk of adverse pregnancy outcome and SGA in particular, but a normal examination does not rule out an adverse pregnancy outcome.
Assuntos
Gonadotropina Coriônica/sangue , Síndrome de Down/diagnóstico por imagem , Complicações na Gravidez/diagnóstico por imagem , Proteína Plasmática A Associada à Gravidez/metabolismo , Artéria Uterina/diagnóstico por imagem , alfa-Fetoproteínas/metabolismo , Adolescente , Adulto , Biomarcadores/sangue , Síndrome de Down/sangue , Feminino , Humanos , Gravidez , Complicações na Gravidez/sangue , Resultado da Gravidez , Segundo Trimestre da Gravidez/sangue , Estudos Prospectivos , Ultrassonografia Doppler/métodos , Artéria Uterina/fisiopatologia , Adulto JovemRESUMO
Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined sharply over the same relatively short period of time with five remaining stable and one showing signs of a marginal increase. Although the causes of these declines are currently unknown, we suspect that they are multi-faceted (such as habitat quality deterioration, prey availability), and with a common cause, e.g. global climate change, at their root.
Assuntos
Serpentes , Animais , Austrália , Biodiversidade , Mudança Climática , Ecossistema , Europa (Continente) , Feminino , Cadeia Alimentar , Masculino , Nigéria , Dinâmica Populacional , Especificidade da Espécie , Fatores de TempoRESUMO
BACKGROUND AND AIMS: Hypoadiponectinemia has been reported in patients with familial combined hyperlipidemia (FCHL) presenting increased waist circumference and insulin resistance. However, no studies have evaluated this association in non-obese FCHL patients. Moreover, it is unclear whether correction of lipoprotein abnormalities may influence adiponectin levels in FCHL. METHODS AND RESULTS: We have compared serum levels of adiponectin in 199 non-obese FCHL patients (BMI 25.96+/-3.7), 116 normolipaemic (NL) non-affected relatives (BMI 24.4+/-4.0) and 192 controls (BMI 28.0+/-7.4). In a subgroup of FCHL patients, changes in adiponectin levels after treatment with atorvastatin (n=22) or fenofibrate (n=26) were also evaluated. FCHL patients as well as their NL relatives showed lower serum adiponectin levels compared to controls (9.7+/-5.4 microg/mL, 10.7+/-5.3 microg/mL and 17.3+/-13.7microg/mL, respectively; p<0.0001 for all comparisons). After controlling for confounders, the strongest association with hypoadiponectinemia was observed with family history of FCHL, followed by HDL-C (negatively) and age (positively). These variables jointly explained 15% of the total variance of serum adiponectin levels. After 24-week of treatment, adiponectin was increased by 12.5% (p<0.05) by atorvastatin and was reduced by 10% by fenofibrate, resulting in a treatment difference of 22.5% in favor of atorvastatin (p<0.017). CONCLUSIONS: FCHL patients showed lower serum adiponectin levels compared to controls. Also normolipaemic relatives of FCHL patients presented decreased levels of adiponectin, suggesting a possible common background in the determination of this abnormality. Overall, these observations indicate that hypoadiponectinemia may be an inherent characteristic of the FCHL phenotype. In FCHL patients hypoadiponectinemia may be partially corrected by atorvastatin but not by fenofibrate treatment.
Assuntos
Fenofibrato/uso terapêutico , Ácidos Heptanoicos/uso terapêutico , Hiperlipidemia Familiar Combinada/sangue , Hiperlipidemia Familiar Combinada/tratamento farmacológico , Hipolipemiantes/uso terapêutico , Pirróis/uso terapêutico , Adiponectina/sangue , Adulto , Distribuição por Idade , Atorvastatina , Biomarcadores/sangue , HDL-Colesterol/sangue , Família , Feminino , Humanos , Hiperlipidemia Familiar Combinada/genética , Resistência à Insulina , Masculino , Pessoa de Meia-Idade , Fenótipo , Prevalência , Ensaios Clínicos Controlados Aleatórios como Assunto , Circunferência da Cintura , Adulto JovemRESUMO
The insulin receptor substrate-1 (IRS-1) plays a central role in insulin sensitivity, and association studies have shown that the IRS-1 G972R variant is a risk factor for insulin resistance. However, how this mutation may lead to impaired insulin sensitivity is still to be determined. Our study aimed to evaluate, after transfection of the IRS-1 G972R variant in 3T3L1 adipocytes, the effect of this mutation on insulin signaling and on cell differentiation. The 3T3L1 cells were transfected with pcDNA3 expression vector containing either the human wild-type IRS-1 or the G972R variant. After induction of differentiation, the 3T3L1 transfected with wild-type IRS-1 differentiated in 6-8 days, while the cells transfected with G972R variant did not differentiate. To determine whether the defect in IRS-1 was responsible for this, we analyzed the expression of several genes involved in the insulin signaling pathway. Results showed that PPARgamma expression was significantly reduced in cells transfected with the mutated IRS-1, together with a significant decrease in binding of phosphatidylinositol-3 kinase (PI 3-kinase) to IRS-1 G972R and in PI 3-kinase activity. In addition, we observed that the interaction between the insulin receptor (IR) and the IRS-1 G972R protein was increased and that the autophosphorylation of the IR was significantly inhibited in 3T3L1-G972R cells compared with 3T3L1-WT. Treatment of the 3T3L1-G972R cells with pioglitazone (PIO), a PPARgamma agonist, restored differentiation with higher level of PPARgamma expression and restoration of PI 3-kinase binding to IRS-1 G972R and PI 3-kinase activity. IR autophosphorylation was also increased. Withdrawal of PIO in fully differentiated 3T3L1-G972R cells determined the reappearance of the insulin signaling defect. Finally, we observed higher levels of IRS-2 expression, suggesting that IRS-2 may play a more important role in adipocyte insulin signaling. In conclusion, IRS-1 G972R variant impairs insulin signaling, and treatment with PPARgamma agonist restores the normal phenotype of 3T3L1 cells.
Assuntos
Adipócitos/fisiologia , Hipoglicemiantes/farmacologia , Insulina/metabolismo , PPAR gama/agonistas , Fosfoproteínas/genética , Transdução de Sinais/genética , Tiazolidinedionas/farmacologia , Células 3T3 , Adipócitos/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Humanos , Proteínas Substratos do Receptor de Insulina , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutação , PPAR gama/análise , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Pioglitazona , Serina/metabolismo , Transdução de Sinais/efeitos dos fármacos , Treonina/metabolismo , Transfecção , Tirosina/metabolismoRESUMO
The optical axes in an array of photoreceptors in the eyes of mantis shrimps have a particular skewing pattern that provides the animal with a monocular distance evaluation. A hardware (HW) device for target recognition was built based on the mathematical model of the biological visual system. The pattern of inputs was simulated by an array of glass fibers connected to phototransistors. In the biological system inputs are picked up by an integrating nerve fiber, in the HW model by an RC network with compartmental threshold devices. The network state is read by a host PC through an array of threshold comparators. The output consists of pulse patterns that can be generated either by a simulation program or in the HW itself. The system can be used as a selective distance/motion detector and can be employed in several applications involving target detection or obstacle avoidance.
RESUMO
Nine peculiar cases of pituitary adenomas were pointed out by a retrospective investigation at the Ospedale di Legnano (from 1978 to 1984) and at the Ospedale di Circolo di Varese (from 1973 to 1986). These tumours are chromophobe adenomas with diffuse structure. Histologically they show typical, large, spheroid and concentric amyloid deposits, in addition to common, amorphous--often perivascular--ones. They were investigated by histochemical methods (Crystal-Violet, Congo-Red) and by immunohistochemical ones as well (anti-PRL and anti-GH), showing that these deposits are amyloid and are in close relation with PRL production. In particular, by immunohistochemical methods we found out that the cells of the tumours displaying spheroidal bodies do contain prolactin, not GH. The amyloid deposits are also immunohistochemically positive to anti-PRL serum, not to anti-GH serum. Finally, by considering the information present in literature, we have discussed the possible pathogenic mechanisms leading to amyloid deposits in pituitary adenomas.
Assuntos
Adenoma Cromófobo/complicações , Amiloidose/etiologia , Neoplasias Hipofisárias/complicações , Prolactina/metabolismo , Prolactinoma/complicações , Adenoma Cromófobo/metabolismo , Adenoma Cromófobo/patologia , Adulto , Amiloidose/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/metabolismo , Neoplasias Hipofisárias/patologia , Prolactinoma/metabolismo , Prolactinoma/patologia , Estudos Retrospectivos , Coloração e RotulagemRESUMO
A case of dilated cardiomyopathy arose after a spontaneous abortion at the second month of pregnancy is reported. Whereas clinical, hemodynamic and gross features pointed to a diagnosis of right ventricular cardiomyopathy, histologic findings of inflammatory infiltration, myocyte degeneration and interstitial fibrosis of the atrial and ventricular walls allowed to a correct diagnosis of chronic myocarditis.
Assuntos
Cardiomiopatia Dilatada/etiologia , Miocardite/complicações , Aborto Espontâneo/complicações , Adulto , Cardiomiopatia Dilatada/patologia , Doença Crônica , Feminino , Átrios do Coração/patologia , Humanos , Miocardite/etiologia , Miocardite/patologia , Gravidez , Fatores de TempoRESUMO
We examined the effect of the antioxidant lazaroid U-74389F on acute lung injury induced in rabbits by phorbol myristate acetate (PMA). Thirty minutes after receiving either U-74389F (15 mg.kg-1 i.v.) or U-74389F vehicle, rabbits (n = 60) were given PMA (60 micrograms.kg-1 i.v.). PMA vehicle injected rabbits (n = 20) served as controls. Over a 5 h period after PMA or PMA vehicle injection, we measured arterial pH, arterial oxygen tension (Pa,O2), arterial carbon dioxide tension (Pa,CO2), and the plasma concentration of the neutrophil chemoattractant interleukin-8 (IL-8). At postmortem, lungs were inspected for macroscopic injury and examined histologically. Malondialdehyde levels were assayed in lung tissue as an index of lipid peroxidation. In bronchoalveolar lavage (BAL), total and differential cell counts, protein and IL-8 concentrations were measured. Compared to normal controls, rabbits challenged with PMA alone developed arterial acidosis, hypercapnia and hypoxaemia, accompanied by significant rise in plasma IL-8 concentration. U-74389F pretreated animals did not develop significant arterial blood gas abnormalities and had significantly lower IL-8 concentration in plasma. U-74389F did not prevent PMA-induced lipid peroxidation. However, macroscopic signs of lung injury and the degree of alveolar haemorrhage and protein extravasation were significantly less severe in pretreated rabbits than in those given PMA alone. In addition, U-74389F significantly reduced IL-8 concentration and neutrophil number in BAL. By histological assessment, 80% of lung neutrophils were localized in alveolar spaces of animals receiving PMA alone. Conversely, in U-74389F pretreated animals, 75% of neutrophils were distributed within extra-alveolar blood vessels and alveolar septa. We conclude that lazaroid U-74389F attenuates lung injury in rabbits given PMA by preventing neutrophil migration into pulmonary alveoli. This effect may, in part, be related to downregulation of IL-8 production.
Assuntos
Antioxidantes/uso terapêutico , Pregnatrienos/uso terapêutico , Síndrome do Desconforto Respiratório/tratamento farmacológico , Animais , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Contagem de Células , Dimetil Sulfóxido/efeitos adversos , Interleucina-8/análise , Interleucina-8/sangue , Pulmão/patologia , Malondialdeído/análise , Neutrófilos/patologia , Proteínas/análise , Coelhos , Síndrome do Desconforto Respiratório/induzido quimicamente , Testes de Função Respiratória , Acetato de Tetradecanoilforbol/efeitos adversosRESUMO
Computed Tomography (CT) has been proved to be the most accurate imaging modality to diagnose emphysema in vivo. Our study was aimed at comparing different CT methods for pulmonary emphysema quantification in patients with severe chronic obstructive pulmonary disease (COPD). Forty-six consecutive inpatients affected with COPD underwent high resolution CT (HRCT). Three scans were acquired at 3 preselected anatomic levels at both full inspiration and expiration. Three different observers were asked to subjectively evaluate, under blind conditions, the extent alone and both the severity and the extent of emphysema on the 6 scans. HRCT findings were also analyzed quantitatively by measuring the mean CT number in Hounsfield Units (HU) and the % of lung area with CT numbers < -900 HU (pixel index). Quantitative CT data were compared with reference values obtained in 7 normal nonsmokers. The CT visual score of emphysema exhibited medium-high interobserver reproducibility with correlation coefficients ranging from 0.80 to 0.96 and a good correlation with pulmonary function tests, particularly relative to the assessment of the extent of emphysema alone as expressed by one observer. CT quantification demonstrated an excellent correlation with functional indices of expiratory airflow, lung volumes and diffusion coefficients (p < 0.001). The expiratory measurements were better than the inspiratory ones while the analysis of both CT number and pixel index gave comparable results. Only the CT expiratory quantitative data allowed to differentiate the patients affected with COPD from the controls. In conclusion, the severity of emphysema as expressed by CT correctly reflects the functional impairment of patients with severe COPD.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Pneumopatias Obstrutivas/diagnóstico por imagem , Enfisema Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Feminino , Humanos , Pneumopatias Obstrutivas/complicações , Pneumopatias Obstrutivas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Enfisema Pulmonar/complicações , Enfisema Pulmonar/fisiopatologia , Reprodutibilidade dos TestesRESUMO
To objectively reappraise the role of the chest radiograph (CXR) in the clinical assessment of emphysema, we compared a standardized reading of CXR with both a visual scoring and a quantitative analysis of high resolution computed tomography (HRCT) of the chest in 46 consecutive patients with chronic obstructive pulmonary disease (COPD) and fixed expiratory airflow limitation. CXR were scored for signs of overinflation and pulmonary vascular deficiency by three independent observers. HRCT scans were independently scored for extent of emphysema and for both severity and extent of emphysema. In 28 of 46 patients, inspiratory and expiratory HRCT scans were analyzed quantitatively by measuring the mean CT number in Hounsfield Units (HU) and the percentage of lung area with CT numbers < -900 HU. Quantitative CT data were compared with reference values obtained in seven normal nonsmokers. The CXR score of emphysema showed a highly significant interobserver reproducibility and correlated linearly (p < 0.001) with HRCT visual scores and quantitative data from both inspiratory and expiratory CT scan. CXR score correlated with functional indices of airflow obstruction, overinflation, and impaired lung diffusing capacity in a way comparable to that obtained by using qualitative and quantitative CT data. Patients with no signs of emphysema on CXR had mean expiratory CT numbers within normal range and a fraction of lung area with CT numbers < -900 HU on expiratory scan not exceeding 15% of total cross-sectional area. The latter value was consistently greater than 15% in patients with CXR score > 0.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Pneumopatias Obstrutivas/complicações , Enfisema Pulmonar/diagnóstico por imagem , Radiografia Torácica , Tomografia Computadorizada por Raios X , Idoso , Feminino , Humanos , Pneumopatias Obstrutivas/fisiopatologia , Masculino , Pessoa de Meia-Idade , Enfisema Pulmonar/etiologia , Mecânica RespiratóriaRESUMO
Several association studies have indicated the insulin receptor substrate-1 (IRS-1) gene G972R variant as a genetic risk factor for insulin resistance, particularly in presence of obesity. A few studies have also suggested a possible effect of the G972R variant on insulin secretion. The aim of this study was to evaluate the role of the IRS-1 gene G972R variant in 61 subjects with "uncomplicated" obesity [i.e. without diabetes, hypertension, dyslipidemia, coronary artery disease (CAD)], studied by hyperinsulinemic-euglycemic clamp. The presence of the G972R variant, detected in real-time with LightCycler hybridisation probes, was related to the indexes of insulin sensitivity. Furthermore, the possible role of this variant on insulin secretion was studied by means of insulin release indexes derived from oral tolerance test (OGTT). Twenty-four point five percent (24.5%) (no.=15) of the obese subjects proved to be carriers of the G972R variant. M index (p<0.05), non-oxidative glucose (p<0.01), insulin clearance (p<0.03) and insulin sensitivity index (ISI) (p<0.005) were all significantly reduced in G972R carriers compared to non-carriers, indicating a significant reduction in insulin sensitivity in carriers of the variant. A logistic regression analysis confirmed the independent association between the G972R variant and reduced insulin sensitivity (p<0.03). The interaction between obesity and the G972R variant was also independently associated with a reduced insulin sensitivity (p<0.005), suggesting that obesity and G972R variant were more than additive in predicting insulin resistance. The analysis of insulin release indexes did not show any significant differences. Our results demonstrate the association of the G972R variant of the IRS-1 gene with reduced insulin sensitivity in obese subjects, and indicate a possible interaction between the IRS-1 variant and obesity in worsening of insulin sensitivity.