Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Phys Rev Lett ; 117(21): 217001, 2016 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-27911551

RESUMO

^{75}As, ^{87}Rb, and ^{85}Rb nuclear quadrupole resonance (NQR) and ^{87}Rb nuclear magnetic resonance measurements in a RbFe_{2}As_{2} iron-based superconductor are presented. We observe a marked broadening of the ^{75}As NQR spectrum below T_{0}≃140 K which is associated with the onset of a charge order in the FeAs planes. Below T_{0} we observe a power-law decrease in the ^{75}As nuclear spin-lattice relaxation rate down to T^{*}≃20 K. Below T^{*} the nuclei start to probe different dynamics owing to the different local electronic configurations induced by the charge order. A fraction of the nuclei probes spin dynamics associated with electrons approaching a localization while another fraction probes activated dynamics possibly associated with a pseudogap. These different trends are discussed in light of an orbital selective behavior expected for the electronic correlations.

2.
Ann Ig ; 18(4): 287-95, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17063627

RESUMO

The majority of investigations of HBV or HCV transmission were carried out on self-selected groups of people; the purpose of this study is to explore the routes of intrafamilial spread of HBV and HCV infection in a general population. Prevalence of hepatitis B and C virus markers was studied at various ages from 20 to 70 in a general population of 960 subjects of 422 households sampled from four towns. Serum specimens were collected for testing hepatitis B markers (HBsAg and anti-HBc) as well as hepatitis C antibodies (anti-HCV). The total prevalence of HBsAg was 5.8% and that of anti-HBc was 41.8%. The overall prevalence of anti-HCV was 4.7%. The odds on having HBsAg or anti-HBc infection for offspring with mother carrier are greater than for offspring with mother seronegative by a factor of about thirty and six respectively. Only anti-HCV positive mothers have a higher risk (OR = 12) of HCV infection in their offspring than in anti-HCV negative mothers. The risk on having a HBsAg or anti-HBc positive wife is significantly increased for exposure to a male partner respectively anti-HBc (OR = 5.6) or HBsAg positive (OR = 6.5), as compared with a male partner seronegative. A statistically significant risk of HBV infection (OR = 2.7) or carrier state (OR = 5.1) in husbands depends on the presence of anti-HBc positivity in their wives. There was no evidence (p >0.05) of a higher risk of HCV infection in spouses due to anti-HCV positivity in their partners. There is a higher risk in offspring exposed to mother seropositive for HBV or HCV infection in comparison with offspring not exposed. Evidence suggests that sexual contact does not play an independent role in the spread of HCV infection in the family setting as much as the HBV infection.


Assuntos
Hepatite B/transmissão , Hepatite C/transmissão , Adulto , Idoso , Biomarcadores , Interpretação Estatística de Dados , Família , Feminino , Hepatite B/diagnóstico , Hepatite B/imunologia , Anticorpos Anti-Hepatite B/análise , Hepatite C/diagnóstico , Hepatite C/imunologia , Anticorpos Anti-Hepatite C/análise , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
3.
J Viral Hepat ; 6(5): 373-80, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10607253

RESUMO

Normalization of serum aminotransferase levels is achieved in approximately 50% of chronic hepatitis C patients treated with interferon (IFN); however, in about one-half of these patients the hepatitis relapses after therapy. In this study we investigated the efficacy of serum hepatitis C virus (HCV) RNA monitoring during IFN therapy to predict the outcome of a biochemical end-of-treatment (ETR) response. Eighty patients with chronic hepatitis C received leucocyte (natural) IFN-alpha (13 patients) or recombinant IFN-alpha2a (67 patients). Antiviral therapy was given for 12 months to 43 (53.7%) responders and this group was analysed further. During follow-up, 15 relapsed and 28 showed a sustained response (median follow-up 50 months, range 39-67 months). Viraemia was monitored at baseline, and at months 1, 3, 6, 9 and 12 of treatment, by nested polymerase chain reaction (PCR) (sensitivity 10-100 copies ml-1). A combination of positive nested PCR and HCV RNA values at the 3rd and 6th months of treatment was 100% predictive of relapse (sensitivity, 66.6%; specificity, 100%). A combination of negative nested PCR and HCV RNA values at the 1st and 3rd months of treatment was 100% predictive of sustained response (sensitivity, 39.3%; specificity, 100%). In conclusion, serum HCV RNA monitoring is an appropriate and reliable tool for predicting early outcome of the biochemical ETR response after IFN discontinuation. This could be useful in the modulation of therapeutic management of chronic hepatitis C.


Assuntos
Antivirais/uso terapêutico , Hepacivirus/fisiologia , Hepatite C Crônica/tratamento farmacológico , Interferon-alfa/uso terapêutico , RNA Viral/sangue , Adulto , Feminino , Hepacivirus/isolamento & purificação , Hepatite C Crônica/virologia , Humanos , Interferon alfa-2 , Leucócitos/imunologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Valor Preditivo dos Testes , Proteínas Recombinantes , Recidiva , Sensibilidade e Especificidade , Resultado do Tratamento , Viremia
4.
J Pathol ; 178(1): 65-70, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8778319

RESUMO

Seventy-nine transitional cell carcinomas (TCCs) of the urinary bladder (25 grade 1, 22 grade 2, and 32 grade 3 tumours) were examined for p53 overexpression by immunohistochemistry with a monoclonal antibody and for human papillomavirus (HPV) infection by the polymerase chain reaction (PCR). Positive immunostaining for p53 was detected in 40.5 per cent of the cases; the percentage of positive cases was significantly lower in low-grade (G1 and G2) TCCs than in high-grade (G3) tumours (10.6 per cent vs. 84.4 per cent; P < 0.0001). The overall rate of HPV infection was 32.9 per cent; 20.3 per cent of the cases were positive for HPV 16, 3.8 per cent for HPV 18, and 8.9 per cent for both. Consensus primers as well as type-specific primers for HPV types 6, 11, and 33 failed to detect any additional case with HPV infection. The prevalence of HPV 16 and/or HPV 18 infection was significantly higher in low-grade than in high-grade tumours (44.7 per cent vs. 15.6 per cent; P = 0.0061). p53-positive cases were more common among papillary, deeply infiltrating tumours, and HPV-positive cases among papillary, non-infiltrating lesions. According to these data, p53 overexpression and HPV 16/18 infection are common findings in bladder TCC and there appears to be an inverse correlation of p53 overexpression and of HPV infection with tumour aggressiveness. The possibility of different molecular pathways in superficial low-grade and in invasive high-grade tumours is suggested.


Assuntos
Carcinoma de Células de Transição/etiologia , Carcinoma de Células de Transição/metabolismo , Papillomaviridae , Infecções por Papillomavirus/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Infecções Tumorais por Vírus/metabolismo , Neoplasias da Bexiga Urinária/etiologia , Neoplasias da Bexiga Urinária/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Southern Blotting , Carcinoma de Células de Transição/virologia , Cocarcinogênese , Feminino , Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteínas de Neoplasias/metabolismo , Reação em Cadeia da Polimerase , Neoplasias da Bexiga Urinária/virologia
5.
Hepatology ; 21(2): 285-90, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7843695

RESUMO

Hepatitis C virus (HCV) infection persists for an indefinite length of time in a major proportion of patients, inducing chronic liver lesions that evolve to cirrhosis and hepatocellular carcinoma (HCC) in approximately 20% of cases. We studied HCV viremia and genotypes by reverse transcription-polymerase chain reaction (RT-PCR) in 341 consecutive anti-HCV-positive patients. Of these, 167 patients had persistently normal or near normal alanine aminotransferase (ALT) levels (fluctuations < or = 5 IU above the upper limit of normal); the remaining 174 patients presented with elevated ALT and histological evidence of chronic liver disease. Seventy percent of patients with normal ALT values had circulating HCV RNA despite the absence of biochemical indicators of liver damage and mild histological forms of chronic hepatitis were detected in most patients who underwent liver biopsy. Isolated genotype III infection was significantly more prevalent in this patient group with respect to control patients with abnormal ALT values (70% vs. 39%; P < .001). Conversely, isolated genotype II was more frequently found in patients with elevated ALT values and evidence of chronic liver disease (45% vs. 23%; P < .01) and it was progressively more represented in advanced liver disease, such as cirrhosis and HCC. Virological features of HCV infection might be associated with different clinical manifestations, suggesting a potential prognostic significance on disease outcome.


Assuntos
DNA Viral/genética , Hepacivirus/genética , Hepatite C/virologia , Hepatopatias/virologia , Viremia/virologia , Adolescente , Adulto , Idoso , Alanina Transaminase/sangue , Sequência de Bases , Feminino , Genótipo , Hepatite C/sangue , Humanos , Hepatopatias/sangue , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Índice de Gravidade de Doença , Viremia/sangue
7.
Thromb Haemost ; 40(2): 428-37, 1978 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-734640

RESUMO

In vitro and in vivo effects of adrenaline (ADR) on platelet aggregation, on platelet factor 3 (PF3) availability and on platelet factor 4 (PF4) release were studied in man. Inhibitory action of an alpha-blocker, phentolamine (PHEN) was investigated in the same conditions. The threshold concentration (TC) of ADR inducing the typical two-phase response in aggregation tests when added to platelet-rich plasma (PRP) varied in different pools of plasma, but always induced an evident PF4 release and increased PF3 availability. A further increase in both parameters was obtained with higher concentrations but without any significant dose/response correlation. Adding PHEN alone to PRP did not induce platelet aggregation or modify PF4 release induced by stirring, but it reduced PF3 availability. On the other hand, PHEN prevented the effects of ADR in different platelet tests, at appropriate concentrations. Intravenous infusion of ADR lowered the TC, and increased PF3 availability and PF4 release. In vivo administration of PHEN, in contrast, increased TC and reduced PF3 availability, while PF4 remained unchanged.


Assuntos
Plaquetas/efeitos dos fármacos , Epinefrina/farmacologia , Fentolamina/farmacologia , Relação Dose-Resposta a Droga , Humanos , Agregação Plaquetária/efeitos dos fármacos , Fator Plaquetário 3/metabolismo , Fator Plaquetário 4/metabolismo
8.
Acta Haematol ; 57(4): 225-32, 1977 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-403728

RESUMO

Six of eight examined members belonging to two generations of the same (NEG-TUR) family were shown to have functional changes in platelets and/or a moderate decrease of factor VIII activity (FVIII:C) in plasma, with normal values of factor VIII-related antigen (VIII R:AG). Platelet defects (mainly a reduced PF3 availability, present in five patients) and factor VIII decrease were combined differently in individual members. Only two male members with both the PF 3 and FVIII:C defects had moderate haemorrhagic symptoms following traumatic injuries. One of them had also an absent adhesiveness to glass, the other one an absent adhesiveness to collagen and a reduced platelet aggregation by ADP and by collagen. Bleeding time, platelet function tests (in the other members), and routine coagulation tests were within normal range; ristocetin aggregation was also normal in all members. We think that two inherited defects, a mild haemophilia A and a "sui generis" thrombocytopathy, co-exist in this family.


Assuntos
Transtornos Plaquetários/genética , Hemofilia A/genética , Adolescente , Contagem de Células Sanguíneas , Feminino , Humanos , Masculino , Linhagem , Adesividade Plaquetária
9.
Haemostasis ; 6(2): 137-48, 1977.
Artigo em Inglês | MEDLINE | ID: mdl-863294

RESUMO

The process of fibrin formation was systematically in 25 patients with severe alcoholic cirrhosis. Results of functional tests are reported. A significant lengthening of the thrombin time was found which could not be completely attributed either to hypofibrinogenaemia or to an increase in physiological anticoagulants or to the presence of pathological antithrombins. A defect in fibrin polymerization was seen in the absence of significant levels of antipolymerizing agents. Indirect evidence pointed to an abnormal fibrinogen function. This was mainly suggested by the "polymerization curves" of mixtures of normal and pathological plasmas and the changes in physico-chemical properties of the clot (optical and elastic properties; tensile strength). Altered synthesis in hepatocytes may lead to an "acquired dysfibrinogenaemia" in the late stages of liver cirrhosis, although alteration of a normal fibrinogen molecule after secretion cannot be definitely excluded.


Assuntos
Fibrina/metabolismo , Cirrose Hepática/sangue , Adulto , Idoso , Testes de Coagulação Sanguínea , Fibrinogênio/análise , Fibrinólise , Humanos , Pessoa de Meia-Idade , Polímeros/análise , Trombina/análise , Fatores de Tempo
10.
Ateneo Parmense Acta Biomed ; 48(2): 157-65, 1977.
Artigo em Italiano | MEDLINE | ID: mdl-883997

RESUMO

Among the atypical pictures of primary aldosteronism, sometimes, normal blood and urine concentration of aldosterone have been observed in association with an adrenal aldosterone-producing adenoma. Here we report a case of atypical primary aldosteronism so characterized: -- the patient had the typical clinical findings of aldosteronism (hypertension, hypokalemic alkalosis, polyuria, etc). -- the patient exhibted all the biochemical abnormalities of primary aldosteronism: increase of exchangeable Na and of plasma volume, decrease of exchangeable K, etc. -- the patient had normal blood and urine levels of aldosterone. -- the patient's blood and urine aldosterone concentration increased following sodium depletion and K administration. Such increase was comparable with that obtained in normal subjects after the same tests. However, at the end of these tests, the patient was still in potassium depletion and sodium repletion. Therefore, it was concluded that the secretion of aldosterone, although normal in absolute values, was inappropriate to the metabolic status of the patient, since such "normal" values were found in association with conditions that should have produced an inhibition of aldosterone production. The catheterization of adrenal veins demonstrated the existence of a right adrenal adenoma. The blood pressure and the biochemical parameters of the patients have been normalized by right adrenalectomy.


Assuntos
Aldosterona/sangue , Hiperaldosteronismo/sangue , Adenoma/complicações , Adenoma/cirurgia , Neoplasias das Glândulas Suprarrenais/complicações , Neoplasias das Glândulas Suprarrenais/cirurgia , Adrenalectomia , Humanos , Hiperaldosteronismo/etiologia , Hiperaldosteronismo/cirurgia , Masculino , Pessoa de Meia-Idade , Potássio/sangue , Sódio/sangue
11.
Arzneimittelforschung ; 26(8): 1532-8, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-12770

RESUMO

The in vitro effects of N-3-(1-benzyl-cycloheptyloxy)-propyl-N,N-dimethylammonium-hydrogenfumarate (bencyclan) on clotting, fibrinolytic and platelet function test were investigated by adding the drug to normal human plasma. An anticoagulant activity, mainly of an antithromboplastin nature (directed against later stages of intrinsic thromboplastin formation and against tissue thromboplastin), was observed, while thrombin phase was unaffected. No effect was found in the fibrinolytic system tested (euglobulin lysis, UK-activated fibrinolysis, "hanging clot" method). The drug, although capable of aggregating platelets by itself at very high concentrations, showed a striking inhibitory effect, over a wide range of concentrations, both on platelet aggregation induced by ADP, epinephrine or collagen and on platelet adhesiveness to glass or collagen. Clot retraction was also clearly inhibited. PF3 availability was influenced with a peculiar two-phase behaviour dose-dependently. High concentrations showed a promoting action, while the lower were obviously inhibitory. It is suggested that the effects on platelet function may be due to an influence of the drug on cell membrane.


Assuntos
Benciclano/farmacologia , Cicloeptanos/farmacologia , Hemostasia/efeitos dos fármacos , Coagulação Sanguínea/efeitos dos fármacos , Testes de Coagulação Sanguínea , Fibrinólise/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Plasma/efeitos dos fármacos , Adesividade Plaquetária/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Tromboplastina/antagonistas & inibidores
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...