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1.
Am J Med Sci ; 363(5): 428-434, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34571038

RESUMO

BACKGROUND: Obesity is a major contributor to inflammation and oxidative stress that are key underlying causes for insulin resistance (IR) and diabetes. Accumulated evidence suggest that RAS may serve as a strong link between IR and obesity. We investigated RAS activity in circulating T cells by obese subjects with and without angiotensin (Ang) II stimulation in presence or not of IR and of low-grade inflammation. METHODS: We studied 29 obese and 10 healthy subjects. After T-lymphocytes isolation, mRNAs for angiotensin converting enzyme (ACE) and angiotensin 1-receptor (AT1-R) were quantified by reverse transcription polymerase chain reaction (RT-PCR). High-sensitivity C-reactive protein (hs-CRP), insulin and inflammatory cytokines serum levels, plasma renin activity (PRA) and ACE activity in cell pellet and supernatant, and angiotensin (Ang) II T cell content were also measured. RESULTS: Under baseline conditions, RAS gene expressions, ACE activity and Ang II levels in T cells, but not PRA, of obese subjects with or without IR and with or without hs-CRP ≥3mg/dl were higher than in controls (p < 0.05). The increase in all parameters induced by Ang II was significantly higher in T cells from the obese subjects with hs-CRP ≥3 mg/dl than in controls or in the obese subjects with hs-CRP <3 mg/dl. In the obese subjects with low grade inflammation and IR, the cytokine serum levels and T cells RAS gene expression was inversely correlated with insulin serum concentration. CONCLUSIONS: Low grade inflammation amplifies the T cell RAS response to Ang II stimulation. T cell RAS gene expressions and serum levels of inflammatory cytokines were inversely related with insulin serum concentration. A protective role of insulin towards the development of inflammatory events can be hypothesized.


Assuntos
Resistência à Insulina , Sistema Renina-Angiotensina , Angiotensina II/metabolismo , Proteína C-Reativa/metabolismo , Citocinas/metabolismo , Humanos , Inflamação/metabolismo , Insulina/metabolismo , Obesidade , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Linfócitos T/metabolismo
2.
Circ Res ; 88(9): 961-8, 2001 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-11349007

RESUMO

In 76 patients with heart failure (HF) (New York Heart Association [NYHA] classes I through IV) and in 15 control subjects, cardiac angiotensin II (Ang II) generation and its relationship with left ventricular function were investigated by measuring aorta-coronary sinus concentration gradients of endogenous angiotensins and in a part of patients by studying (125)I-labeled Ang I kinetics. Gene expression and cellular localization of the cardiac renin-angiotensin system components, the density of AT(1) and AT(2) on membranes and isolated myocytes, and the capacity of isolated myocytes for synthesizing the hypertrophying growth factors insulin-like growth factor-I (IGF-I) and endothelin (ET)-1 were also investigated on 22 HF explanted hearts (NYHA classes III and IV) and 7 nonfailing (NF) donor hearts. Ang II generation increased with progression of HF, and end-systolic wall stress was the only independent predictor of Ang II formation. Angiotensinogen and angiotensin-converting enzyme mRNA levels were elevated in HF hearts, whereas chymase levels were not, and mRNAs were almost exclusively expressed on nonmyocyte cells. Ang II was immunohistochemically detectable both on myocytes and interstitial cells. Binding studies showed that AT(1) density on failing myocytes did not differ from that of NF myocytes, with preserved AT(1)/AT(2) ratio. Conversely, AT(1) density was lower in failing membranes than in NF ones. Ang II induced IGF-I and ET-1 synthesis by isolated NF myocytes, whereas failing myocytes were unable to respond to Ang II stimulation. This study demonstrates that (1) the clinical course of HF is associated with progressive increase in cardiac Ang II formation, (2) AT(1) density does not change on failing myocytes, and (3) failing myocytes are unable to synthesize IGF-I and ET-1 in response to Ang II stimulation.


Assuntos
Angiotensina II/metabolismo , Doenças Cardiovasculares/metabolismo , Miocárdio/metabolismo , Função Ventricular Esquerda , Análise de Variância , Angiotensina I/metabolismo , Angiotensina I/farmacologia , Angiotensina II/farmacologia , Angiotensinogênio/genética , Cardiomiopatia Dilatada/genética , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/patologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/patologia , Quimases , Endotelina-1/genética , Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Ventrículos do Coração/citologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/fisiopatologia , Imuno-Histoquímica , Hibridização In Situ , Fator de Crescimento Insulin-Like I/genética , Radioisótopos do Iodo , Isquemia Miocárdica/genética , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patologia , Peptidil Dipeptidase A/genética , Fator de Crescimento Derivado de Plaquetas/genética , Precursores de Proteínas/genética , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/genética , Serina Endopeptidases/genética
3.
Circ Res ; 89(11): 977-82, 2001 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-11717153

RESUMO

Physiological hypertrophy represents the adaptive changes of the heart required for supporting the increased hemodynamic load in regularly trained healthy subjects. Mechanisms responsible for the athlete's hypertrophy still remain unknown. In 15 trained competitive soccer players and in 15 healthy men not engaged in sporting activities (sedentary control subjects) of equivalent age, we investigated the relationship among cardiac growth factor formation, cardiac sympathetic activity, and left ventricular morphology and function. Cardiac formation of insulin-like growth factor (IGF)-I, endothelin (ET)-1, big ET-1, and angiotensin (Ang) II was investigated at rest by measuring artery-coronary sinus concentration gradients. Cardiac sympathetic activity was studied by [(3)H]norepinephrine (NE) kinetics. Cardiac IGF-I, but not ET-1, big ET-1, and Ang II, formation was higher in athletes than in control subjects (P<0.01). NE levels in arterial and peripheral venous blood did not differ between groups. In contrast, coronary sinus NE concentration was higher in athletes than in control subjects (P<0.01). Cardiac, but not total systemic, NE spillover was also increased in athletes (P<0.01), whereas cardiac [(3)H]NE reuptake and clearance were not different. Echocardiographic modifications indicated a volume overload-induced hypertrophy associated with increased myocardial contractility. Multivariate stepwise analysis selected left ventricular mass index as the most predictive independent variable for cardiac IGF-I formation and velocity of circumferential fiber shortening for cardiac NE spillover. In conclusion, increased cardiac IGF-I formation and enhanced sympathetic activity selectively confined to the heart appear to be responsible for the physiological hypertrophy in athletes performing predominantly isotonic exercise.


Assuntos
Exercício Físico/fisiologia , Coração/inervação , Hipertrofia Ventricular Esquerda/metabolismo , Hipertrofia Ventricular Esquerda/fisiopatologia , Fator de Crescimento Insulin-Like I/biossíntese , Sistema Nervoso Simpático/fisiopatologia , Adulto , Angiotensina II/biossíntese , Ecocardiografia , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Masculino , Miocárdio/metabolismo , Norepinefrina/sangue , Futebol
4.
Circ Res ; 85(1): 57-67, 1999 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-10400911

RESUMO

The aim of the present study was to investigate whether and which cardiac growth factors are involved in human hypertrophy, whether growth factor synthesis is influenced by overload type and/or by the adequacy of the hypertrophy, and the relationships between cardiac growth factor formation and ventricular function. Cardiac growth factor formation was assessed by measuring aorta-coronary sinus concentration gradient in patients with isolated aortic stenosis (n=26) or regurgitation (n=15) and controls (n=12). Gene expression and cellular localization was investigated in ventricular biopsies using reverse transcriptase-polymerase chain reaction and in situ hybridization. Cardiac hypertrophy with end-systolic wall stress <90 kdyne/cm2 was associated with a selective increased formation of insulin-like growth factor (IGF)-I in aortic regurgitation and of IGF-I and endothelin (ET)-1 in aortic stenosis. mRNA levels for IGF-I and preproET-1 were elevated and mainly expressed in cardiomyocytes. At stepwise analysis, IGF-I formation was correlated to the mean velocity of circumferential fiber shortening (r=0.86, P<0.001) and ET-1 formation to relative wall thickness (r=0.82, P<0. 001). When end-systolic wall stress was >90 kdyne/cm2, IGF-I and ET-1 synthesis by cardiomyocytes was no longer detectable, and only angiotensin (Ang) II was generated, regardless of the type of overload. The mRNA level for angiotensinogen was high, and the mRNA was exclusively expressed in the interstitial cells. Ang II formation was positively correlated to end-systolic stress (r=0.89, P<0.001) and end-diastolic stress (r=0.84, P<0.001). Multivariate stepwise analysis selected end-systolic stress as the most predictive variable and left ventricular end-diastolic pressure as the independent variable for Ang II formation (r=0.93, P<0.001). In conclusion, the present results indicate that the course of human left ventricular hypertrophy is characterized by the participation of different cardiac growth factors that are selectively related both to the type of hemodynamic overload and to ventricular function.


Assuntos
Cardiomegalia/metabolismo , Substâncias de Crescimento/metabolismo , Miocárdio/metabolismo , Idoso , Angiotensinas/sangue , Cardiomegalia/sangue , Cardiomegalia/diagnóstico por imagem , Cardiomegalia/fisiopatologia , Ecocardiografia , Endotelinas/sangue , Substâncias de Crescimento/sangue , Coração/fisiopatologia , Hemodinâmica/fisiologia , Humanos , Fator de Crescimento Insulin-Like I/análise , Pessoa de Meia-Idade , Contração Miocárdica/fisiologia , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estresse Mecânico
5.
J Am Coll Cardiol ; 38(1): 49-55, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451295

RESUMO

OBJECTIVES: The aim of this study was to investigate the activity of the cardiac renin-angiotensin system (RAS) in unstable angina (UA). BACKGROUND: Angiotensin (Ang) II locally produced by continuously operating cardiac RAS may affect the pathophysiology of UA. METHODS: In 35 patients with UA, 32 with stable effort angina (SA) and 21 with atypical chest pain (controls), cardiac RAS was investigated during coronary angiography after five days of Holter monitoring by combining the measurement of aorta-coronary sinus gradient for Ang I and Ang II with the kinetics study of 125I-Ang I. Messenger RNAs (mRNA) for all the components of RAS were also quantified with the reverse transcriptase-polymerase chain reaction (RT-PCR) and localized by in situ hybridization in myocardial biopsy specimens from patients who underwent aorta-coronary bypass surgery. RESULTS: Cardiac Ang II generation was higher in patients with UA than it was in patients with SA or in controls (p < 0.001) due to increased de novo cardiac Ang I formation and its enhanced fractional conversion rate to Ang II. Messenger RNA levels for angiotensinogen (AGTN), angiotensin-converting enzyme (ACE) and Ang II type 1 (AT1) subtype receptors were higher in patients with UA (p < 0.01) than they were in patients with SA or in control hearts. Messenger RNAs for AGTN and ACE were almost exclusively expressed on endothelial and interstitial cells. Angiotensin II formation was correlated with ischemia burden (p < 0.001). However, the amount of Ang II formed and the expression levels of mRNAs for AGTN, ACE and AT1 were not related to the time that had elapsed since the last anginal attack. CONCLUSIONS: In patients with UA, cardiac RAS is activated, resulting in increased Ang II formation. Myocardial ischemia is essential for RAS activation, but it is unlikely to be a direct and immediate cause of RAS activation.


Assuntos
Angina Instável/fisiopatologia , Sistema Renina-Angiotensina , Idoso , Angiotensina II/fisiologia , Feminino , Humanos , Hibridização In Situ , Masculino , Pessoa de Meia-Idade , Miocárdio/enzimologia , RNA Mensageiro/análise , Receptores de Angiotensina/fisiologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Hypertension ; 31(3): 836-42, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9495269

RESUMO

A growing body of evidence supports the existence of a tissue-based renin-angiotensin system (RAS) in the vasculature, but the functional capacity of vascular RAS was not investigated in humans. In 28 normotensive healthy control subjects, the metabolism of angiotensins through vascular tissue was investigated in normal, low, and high sodium diets by the measurement of arterial-venous gradient of endogenous angiotensin (Ang) I and Ang II in two different vascular beds (forearm and leg), combined with the study of 125I-Ang I and 125I-Ang II kinetics. In normal sodium diet subjects, forearm vascular tissue extracted 36+/-6% of 125I-Ang I and 30+/-5% of 125I-Ang II and added 14.9+/-5.1 fmol x 100 mL(-1) x min(-1) of de novo formed Ang I and 6.2+/-2.8 fmol x 100 mL(-1) x min(-1) of Ang II to antecubital venous blood. Fractional conversion of 125I-Ang I through forearm vascular tissue was about 12%. Low sodium diet increased (P<.01) plasma renin activity, whereas de novo Ang I and Ang II formation by forearm vascular tissue became undetectable. Angiotensin degradation (33+/-7% for Ang I and 30+/-7% for Ang II) was unchanged, and vascular fractional conversion of 125I-Ang I decreased from 12% to 6% (P<.01). In high sodium diet subjects, plasma renin activity decreased, and de novo Ang I and Ang II formation by forearm vascular tissue increased to 22 and 14 fmol x 100 mL(-1) x min(-1), respectively (P<.01). Angiotensin degradation did not significantly change, whereas fractional conversion of 125I-Ang I increased from 12% to 20% (P<.01). Leg vascular tissue functional activities of RAS paralleled those of forearm vascular tissue both at baseline and during different sodium intake. These results provide consistent evidence for the existence of a functional tissue-based RAS in vascular tissue of humans. The opposite changes of plasma renin activity and vascular angiotensin formation indicate that vascular RAS is independent from but related to circulating RAS.


Assuntos
Angiotensina II/efeitos dos fármacos , Angiotensina I/efeitos dos fármacos , Sistema Renina-Angiotensina/efeitos dos fármacos , Sódio na Dieta/farmacologia , Adulto , Angiotensina I/metabolismo , Angiotensina II/metabolismo , Método Duplo-Cego , Feminino , Antebraço/irrigação sanguínea , Humanos , Perna (Membro)/irrigação sanguínea , Masculino , Sistema Renina-Angiotensina/fisiologia , Sódio na Dieta/administração & dosagem
7.
Artigo em Inglês | MEDLINE | ID: mdl-7675825

RESUMO

In order to investigate the possible mechanisms underlying platelet functional changes in patients affected by neoplasms, platelet lipid composition, plasma beta-thromboglobulin (Beta-TG) and serum thromboxane B2 (TXB2) were investigated in 16 male patients affected by pulmonary carcinoma and in 16 comparable control subjects. In patients high levels of plasma Beta-TG (67 +/- 9 versus controls 14 +/- 4 ng/ml, p < 0.001) and serum TXB2 (434 +/- 56 versus 223 +/- 48 ng/ml, p < 0.001) were observed. Also platelet lipid composition was found altered in patients with respect to controls (lower percent levels in n-3 fatty acids and in linoleic acid esterified in the main platelet phospholipid fractions: at least p < 0.05). These results indicate that in vivo platelet activation is detectable in neoplastic patients and it is associated with alterations in platelet lipid composition. In the light of the important role played by membrane lipids in platelet functions related to thrombosis and haemostasis we conclude that platelet lipid changes could cooperate in platelet activation and increased thrombotic risk so frequently observed in neoplastic disease.


Assuntos
Plaquetas/metabolismo , Carcinoma de Células Escamosas/sangue , Lipídeos/sangue , Neoplasias Pulmonares/sangue , Ativação Plaquetária , Adulto , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Humanos , Ácido Linoleico , Ácidos Linoleicos/sangue , Masculino , Fator Plaquetário 4/metabolismo , Tromboxano B2/sangue , beta-Tromboglobulina/metabolismo
8.
Artigo em Inglês | MEDLINE | ID: mdl-1908102

RESUMO

An increased risk of cardiovascular disease has been found in postmenopausal women in comparison to premenopausal women. The aim of this study was to investigate platelet function, blood clotting and plasma lipid levels in 12 women with a condition of hypoestrogenism, similar to the postmenopausal status induced by treatment with the GnRH analogue buserelin for uterine leiomyoma. Platelet aggregation in whole blood and platelet-rich plasma (PRP), serum thromboxane (TX) B2 production, fibrinopeptide A (FPA) plasma levels and plasma lipid pattern were measured before and after 13 weeks of buserelin treatment. No changes of platelet aggregability were found either in whole blood or PRP. Serum TXB2 generation increased significantly after 13 weeks of therapy (p less than 0.001). No signs of increased thrombin generation were found, as indicated by unchanged FPA plasma levels. Total cholesterol plasma levels were found increased after 13 weeks, LDL cholesterol levels showed a tendency to increase although not significantly. HDL cholesterol and triglyceride concentrations were unaffected. The changes of arachidonic acid metabolism and lipid pattern suggest that buserelin treatment may induce a condition of increased thrombotic risk even if the lack of enhanced thrombin generation and increased platelet aggregability indicates that no blood clotting activation occurs.


Assuntos
Busserrelina/farmacologia , Lipídeos/sangue , Menopausa/efeitos dos fármacos , Tromboxano A2/biossíntese , Adulto , Coagulação Sanguínea/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Feminino , Hormônios Esteroides Gonadais/metabolismo , Humanos , Leiomioma/tratamento farmacológico , Pessoa de Meia-Idade , Neoplasias Uterinas/tratamento farmacológico
9.
Artigo em Inglês | MEDLINE | ID: mdl-2119509

RESUMO

Platelet lipid composition, c arachidonic acid (AA) metabolism by platelets (stimulated with thrombin), serum thromboxane (Tx)B2 production and plasma lipid composition were investigated in 53 healthy females (18-45 years) and 65 males (19-45 years) with similar dietary habits. In males, serum TxB2 production and cholesterol platelet membrane levels were found significantly higher (p less than 0.001 and p less than 0.05) than in females. No differences were observed between the two groups in the AA conversion through cyclo-oxygenase and lipoxygenase pathways or in the platelet phospholipid fatty acid composition. These findings indicate that in males the platelet proaggregatory capacity is greater than in females and the higher platelet TxB2 production does not depend on a larger AA availability or on enzyme activation for its conversion. The increased TxB2 production may be, at least in part, induced by functional differences such as a different membrane cholesterol content inducing, in its turn, an increased microviscosity and/or higher number of platelet receptors for thrombin.


Assuntos
Ácidos Araquidônicos/metabolismo , Plaquetas/metabolismo , Caracteres Sexuais , Tromboxano A2/biossíntese , Ácido 8,11,14-Eicosatrienoico/metabolismo , Adolescente , Adulto , Ácidos Araquidônicos/sangue , Ácido Eicosapentaenoico/metabolismo , Feminino , Humanos , Lipoxigenase/metabolismo , Masculino , Pessoa de Meia-Idade , Fosfolipídeos/metabolismo , Agregação Plaquetária , Contagem de Plaquetas , Prostaglandina-Endoperóxido Sintases/metabolismo , Tromboxano A2/sangue
10.
Artigo em Inglês | MEDLINE | ID: mdl-2177201

RESUMO

Functional activity of polymorphonuclear neutrophils (PMN) is associated with the metabolism of Arachidonic Acid (AA) released from membrane phospholipids. In this study the in vitro effect of dipyrone, a non steroidal anti-inflammatory drug, on the production of AA metabolites through cyclooxygenase (CO) and lipoxygenase (LO) pathways by stimulated PMN has been investigated. PMN isolated by counterflow centrifuge elutriator were greater than 98% pure and viable. Metabolite production was evaluated by RIA of Thromboxane A2 (TxA2), Prostaglandin E2 (PGE2), Leukotriene B2 (LTB4) and Leukotriene C4 (LTC4) after PMN stimulation with calcium ionophore A 23187 (20 microM). The levels of beta-thromboglobulin (RIA) lower than 5 ng/ml allowed us to rule out activation of residual contaminant platelets. In these experimental conditions, in the absence of dipyrone the products (ng/10(6) cells) of AA metabolism were LTB4 (3.51 +/- 0.22), LTC4 (0.81 +/- 0.08), TxB2 (0.144 +/- 0.025) and PGE2 (0.150 +/- 0.017). Incubation with dipyrone induced changes of PGE2 and TXB2 production in a dose dependent fashion (r = 0.83 and r = 0.87, p less than 0.001), obtaining already at the lowest drug concentration (5 micrograms/ml) a significant inhibition (33 and 40% for TxB2 and PGE2 p less than 0.005). No significant changes of LTB4 and LTC4 production have been observed. The results of this study indicate that dipyrone relevantly affects CO metabolite synthesis by stimulated PMN at concentrations comparable to those reached in therapeutic use. The inhibition of PGE2 synthesis which is present in inflamed tissues and actively participates in inflammatory reactions, could contribute to the therapeutic anti-inflammatory action of dipyrone.


Assuntos
Ácidos Araquidônicos/biossíntese , Dipirona/farmacologia , Lipoxigenase/biossíntese , Neutrófilos/enzimologia , Prostaglandina-Endoperóxido Sintases/biossíntese , Calcimicina/administração & dosagem , Calcimicina/farmacologia , Células Cultivadas , Dinoprostona/biossíntese , Relação Dose-Resposta a Droga , Humanos , Leucotrieno B4/biossíntese , Neutrófilos/efeitos dos fármacos , Tromboxano B2/biossíntese
11.
Artigo em Inglês | MEDLINE | ID: mdl-2339137

RESUMO

Prostaglandin (PG) E2, 6ketoPGF1 alpha and Thromboxane B2 (TxB2) production by the tumor, peritumor and control tissue were investigated in specimens from patients (n = 11) with squamous cell carcinoma of the larynx, in relation to the extension and infiltration of the neoplasm and to the presence of inflammation, fibrosis and necrosis. In all specimens detectable amounts of 6ketoPGF1+ and TxB2 were found, but the predominant metabolite was PGE2. No differences in the levels of TxB2 and 6ketoPGF1 alpha were observed, but the only patient with lymphnodal involvement showed the lowest levels of 6ketoPGF1 alpha both in tumor and peritumor tissue. Higher amounts (p less than 0.05) of PGE2 were synthesized by peritumor tissues in comparison to control mucosa and tumor tissue independently of the occurrence of reactive infiltration. PGs synthesis did not correlate with inflammation, fibrosis, necrosis or staging of the neoplasm. However the two cases in stage T4 showed PGE2 generation at the highest levels both in neoplastic and perineoplastic tissue. These findings indicate that in squamous cell carcinoma of the larynx an increased production of PGE2 occurs, stemming not only from inflammatory cells but at least in part from neoplastic cells. This suggests that the study of arachidonic acid metabolism may contribute to characterization of the primary cancer and lead to better understanding of the mechanisms of tumor growth and diffusion.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Laríngeas/metabolismo , Prostaglandinas/biossíntese , 6-Cetoprostaglandina F1 alfa/biossíntese , Idoso , Idoso de 80 Anos ou mais , Ácidos Araquidônicos/metabolismo , Dinoprostona/biossíntese , Feminino , Fibrose , Humanos , Laringite/metabolismo , Laringe/patologia , Masculino , Pessoa de Meia-Idade , Necrose , Tromboxano B2/biossíntese
12.
Thromb Res ; 51(5): 533-41, 1988 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-3175991

RESUMO

Thromboxane B2 (TxB2) determination is usually performed by using commercial 3H-RIA kits. However, the low amounts of TxB2 present in plasma are not detectable without previous extraction. The aim of this study is the evaluation of 1) plasma protein interferences on the binding and separation steps of bound from free analyte and 2) charcoal efficacy in different experimental conditions. Our results indicate that plasma proteins do not influence the antibody binding, but significantly reduce the efficacy of precipitation of kit dextran-charcoal, so that the supernate radioactivity rises with the protein amount increase (r = 0.99 p less than 0.001). Such greater number of counts in the samples determines a lower estimation of TxB2 concentration in plasma when the calibration curve is set up in buffer. Our findings suggest that, in order to measure low amounts of plasma TxB2 without extraction, it is useful: 1) to refer to a calibration curve set up in buffer-diluted plasma, 2) to use the uncoated charcoal concentration allowing the lowest stripping and 3) to perform all steps at 4 degrees C.


Assuntos
Radioimunoensaio/métodos , Tromboxano B2/sangue , Carvão Vegetal , Humanos , Padrões de Referência , Temperatura , Tromboxano B2/normas
13.
Thromb Res ; 50(5): 593-604, 1988 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-3413721

RESUMO

Platelets from patients with familial hypercholesterolemia (type IIa hyperlipoproteinemia), a condition associated with high prevalence of atherosclerosis and of its thrombotic complications, are known to be hyperresponsive to aggregating stimuli and to synthesize increased amounts of thromboxane A2 (TxA2) in comparison to platelets from normal subjects. In order to search if these functional alterations are linked to a different platelet lipid composition, we studied a group of young patients affected by IIa hyperlipoproteinemia and a group of suitable controls with similar dietary habits. Both cholesterol and phospholipid content of platelets were higher in patients than in controls with a significant increase of cholesterol/phospholipid molar ratio (at least p less than 0.05). The percent contents of the main platelet phospholipid fractions were not altered, while an increase in saturated fatty acids, both unesterified and esterified in different lipid fractions, was observed. Moreover, an increased TxA2 production by platelets and a significantly increased number of megathrombocytes occur in patients with respect to controls (p less than 0.001). Our results indicates that platelets from patients with IIa hyperlipoproteinemia have an altered lipid composition which could explain, at least in part, the enhanced platelet reactivity reported in these patients.


Assuntos
Plaquetas/metabolismo , Hiperlipoproteinemia Tipo II/sangue , Lipídeos/sangue , Tromboxano A2/biossíntese , Adulto , Eritrócitos/metabolismo , Feminino , Humanos , Masculino , Contagem de Plaquetas , Tromboxano A2/sangue
14.
Thromb Res ; 54(6): 751-8, 1989 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-2781513

RESUMO

Alterations in blood rheological properties have been reported in diabetes mellitus. Changes in lipid composition of red blood cell (RBC) membranes resulting in an impairment of RBC deformability may play a role in the altered blood rheological pattern. The aim of this study was to investigate the lipid composition of RBC membrane in a group of patients affected by type II diabetes (age 21-45 years), selected on the basis of the absence of complications and good metabolic control, and in a group of suitable control subjects. Saturated fatty acid amounts in the different phospholipid fractions were significantly higher in diabetics than in controls (p less than 0.05), whereas polyunsaturated fatty acids were decreased (p less than 0.05). Cholesterol/phospholipid molar ratio was not altered. On the contrary, sphingomyelin/phosphatidylcholine ratio was higher in diabetics than in controls (1.10 +/- 0.08 vs 0.96 +/- 0.10, p less than 0.01) due specially to high levels of sphingomyelin. These alterations could account for the impairement of RBC deformability frequently reported in diabetes mellitus, independently of metabolic control and the presence of severe atherosclerotic lesions.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Eritrócitos/metabolismo , Lipídeos/sangue , Adulto , Colesterol/sangue , HDL-Colesterol/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Triglicerídeos/sangue
15.
Anat Embryol (Berl) ; 177(1): 91-6, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3439640

RESUMO

A two-cell human embryo recovered from the Fallopian tube 82 h following the LH peak in plasma and 37 h after a single episode of intercourse was examined by transmission electron microscopy. At the time of recovery the embryo was denuded of cumulus cells, and both the zona pellucida and the two adjoining blastomeres were intact. The finding of two polar bodies in the perivitelline space, two nucleated blastomeres and remnants of the fertilizing sperm tail within the cytoplasm of one of them, were considered as evidences that the embryo was normally fertilized. Among the most conspicuous features found were the presence of very distinct desmosome-like structures between blastomeres, and the cytoplasmic cell organelles distribution in three areas referred as: a sub-cortical, a middle and a perinuclear bands. An outstanding feature was the extensive blebbing of the nuclear envelope. In general, the features seem to correspond to a normally developing two-cell embryo undergoing cleavage at a normal rate.


Assuntos
Blastômeros/ultraestrutura , Fase de Clivagem do Zigoto/ultraestrutura , Desmossomos/ultraestrutura , Humanos , Inseminação , Organoides/ultraestrutura
16.
Anat Embryol (Berl) ; 170(1): 107-12, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6541005

RESUMO

The cumulus cell mass enclosing a penetrated human egg was studied. The egg, recovered from the Fallopian tube approximately 80 h after luteinizing hormone peak and 35 h after insemination, was surrounded by a large, expanded and dissociated cumulus. Dispersions of the outermost cumulus cell layers occurred during processing, the innermost cell layers remained attached enclosing the egg. The photomicrographs showed that the follicular cells were embedded in an intercellular matrix and contact via gap-junction-like structures between neighboring cells existed. Cumulus cell processes traversing the zona pellucida were not found. Two types of follicular cells coexisted within the cumulus, light and dark cells. These cellular types, were different in morphology and size. Light cells displayed cytoplasmic organelles normally associated with protein synthesis and steroidogenesis. Dark cells with long cytoplasmic processes were involved in sperm phagocytosis. It is suggested from the characteristics of the cytoplasmic organelles that dark cells seem to be modified light follicular cells.


Assuntos
Óvulo/ultraestrutura , Feminino , Fertilização , Humanos , Microscopia Eletrônica , Óvulo/citologia , Óvulo/fisiologia
17.
Anat Embryol (Berl) ; 173(2): 247-52, 1985.
Artigo em Inglês | MEDLINE | ID: mdl-4083525

RESUMO

The ultrastructure of human spermatozoa located in the cumulus cells and the zona pellucida of a pro-nuclear egg, and in the zona pellucida of a two-cell egg, both fertilized in-vivo, has been analysed in order to understand how the human spermatozoon penetrates the investing coats of the oocyte. Among the 36 spermatozoa found in the cumulus cells, 31 were phagocytosed by cumulus cells and 5 were wedged in the matrix between the cells. These spermatozoa were acrosome-reacted and their equatorial segment was intact. Six of the seven spermatozoa found in the zona pellucida (four spermatozoa in the pronuclear egg and three in the two-cell egg) had lost the equatorial segment, while the other one was partially reacted. The sperm heads were located in slits with sharp edges. From these findings it was concluded that in the human (1) only few and normal spermatozoa seem to reach the cumulus cells after natural insemination, (2) the acrosome reaction probably occurs sometime before the spermatozoa reach the vicinity of the corona cells, (3) the reaction of the equatorial segment seems to occur during or before the initial phase of zona penetration, since the spermatozoa located in the matrix of the zona pellucida had no equatorial segment. No evidence of the presence of spermatozoa with an intact acrosome in the matrix of cumulus cells or with an intact equatorial segment in the zona pellucida were found.


Assuntos
Interações Espermatozoide-Óvulo , Feminino , Humanos , Masculino , Microscopia Eletrônica , Espermatozoides/ultraestrutura , Zona Pelúcida/ultraestrutura
18.
J Reprod Med ; 29(10): 731-5, 1984 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6512782

RESUMO

The ability of the normal rabbit fimbria to retrieve eggs after progressive reduction of its mucosal surface was tested on 16 New Zealand white rabbits. Group 1 had a small fimbrial resection; group 2 had a large one. The resected tissue was weighed, and in both groups the contralateral fimbria (internal control) was cut and sutured without resection. Four weeks later the animals were mated, and 12 hours afterwards the ovulation sites on each ovary were counted and both tubes excised. In vivo observations of the transport of cumulus surrogates by the experimental fimbria were made before tubal excision in group 2 animals. The natural eggs retrieved by the fimbria were recovered by flushing the resected tubes with saline. The infundibulum and fimbria were cut from the ampulla and weighed to calculate the amount of fimbrial resection achieved. In group 1 the experimental side retrieved 82% of the eggs; in group 2 the experimental side retrieved 72%. In vivo observations revealed the presence of a spontaneously formed neofimbria that transported cumulus surrogates in a normal pattern and at a normal rate. The fimbria appeared dispensable, a fimbrialike structure formed spontaneously, the functional results were optimal, and the number of ovulation after surgery was unchanged. Some similarities can be observed in women.


Assuntos
Tubas Uterinas/fisiologia , Animais , Tubas Uterinas/cirurgia , Feminino , Ovulação , Transporte do Óvulo , Coelhos
19.
Minerva Med ; 74(36): 2057-62, 1983 Sep 22.
Artigo em Italiano | MEDLINE | ID: mdl-6621904

RESUMO

Painful epigastric syndrome where gastroenteric or extra-digestive lesions are not revealed by common investigatory techniques (x-rays, endoscopy) are often diagnosed as primary or functional dyspepsia. This review is important because about half of the sufferers complain of functional gastroenteric disorders. The term "Dyspepsia" is reviewed on the basis of old and more recent literature together with long personal experience. The overall results confirm the existence of Dyspepsia as a separate complaint in its own right. The importance of Dyspepsia should be fully understood since a correct diagnosis avoids the need of further checks and choice of pharmaceutical treatment is made easier. Support psychotherapy and diet revision are also facilitated.


Assuntos
Dispepsia/diagnóstico , Colelitíase/complicações , Diagnóstico Diferencial , Dispepsia/etiologia , Dispepsia/psicologia , Gastrite/diagnóstico , Humanos , Relações Médico-Paciente , Úlcera Gástrica/diagnóstico
20.
Minerva Med ; 73(46): 3283-96, 1982 Nov 30.
Artigo em Italiano | MEDLINE | ID: mdl-7177459

RESUMO

A group of 48 patients (42 suffering from hepato-biliary diseases and 6 without hepatic diseases) was followed by the authors for a period lasting from 5 to 8 years, 13 out of them for longer. The hepatic disease was assessed on the basis of physical examination, current liver chemistry and proper and specific instrumental procedures. Initial and final diagnosis and the aminotransferases (AST, ALT) trend in years were carefully considered. First of all it was concluded that no advantage is obtained in monitoring the two aminotransferases instead of one alone. Moreover it is stressed the opportunity of referring aminotransferases activities in a simple way such as per cent of variation as referred to considered upper normal value differing from one to the other laboratory. The aminotransferase increase maintains an important and diagnostic significance in acute liver damage such as in acute hepatitis. An inappreciable prognostic value may be drawn from the follow up of these enzymatic parameters: for example the development of posthepatic fibrosis, or cirrhosis or hepatoma cannot be foreseen on the basis of the aminotransferases trend. A greater variability and sharp increases in AST-ALT values are recorded in patients with biliary gallstones.


Assuntos
Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Doenças da Vesícula Biliar/enzimologia , Hepatopatias/enzimologia , Adulto , Feminino , Doenças da Vesícula Biliar/diagnóstico , Humanos , Hepatopatias/diagnóstico , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Prognóstico
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