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61.
62.
D Rodríguez-Pérez Oscar Sotolongo-Grau Ramón Espinosa Riquelme Oscar Sotolongo-Costa J Antonio Santos Miranda J C Antoranz 《Mathematical medicine and biology》2007,24(3):287-300
A cytokine-based periodic immunotherapy treatment is included in a model of tumour growth with a delay. The effects of dose schedule are studied in the case of a weak immune system and a growing tumour. We find the existence of 'metastable' states (that may last for tens of years) induced by the treatment and also potentially adverse effects of the dosage frequency on the stabilization of the tumour. These two effects depend on the delay between the tumour growth and the immune system response, the cytokine dose burden, and other parameters considered in the model. 相似文献
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64.
K-ras gene mutational analysis supports a monoclonal origin of biphasic pleomorphic carcinoma of the lung. 总被引:2,自引:0,他引:2
Giuseppe Pelosi Aldo Scarpa Michela Manzotti Giulia Veronesi Lorenzo Spaggiari Filippo Fraggetta Oscar Nappi Elvira Benini Felice Pasini Davide Antonello Antonio Iannucci Patrick Maisonneuve Giuseppe Viale 《Modern pathology》2004,17(5):538-546
We investigated 27 pleomorphic carcinomas of the lung for exon 1 K-ras gene mutations using polymerase chain reaction-single-strand conformation polymophism analysis and direct sequencing. All pleomorphic carcinomas were biphasic, that is, composed of an adeno-, squamous- or large-cell-carcinomatous component associated with a spindle- and/or giant-cell component. Of 27 cases, six (22%) showed K-ras codon 12 mutations, which is a figure higher than that previously reported on in pure sarcoma-like pleomorphic carcinomas. Five tumors displayed the same mutation in both the epithelial and the sarcomatoid components, whereas in one tumor the mutation was restricted to the epithelial component. All mutations occurred in smokers, and were transversions, including GGT (glycine) to TGT (cysteine) change in two cases, to GCT (alanine) in two and to GTT (valine) in two. No significant relationships were found between the occurrence and type of mutations and patients' survival or any other clinicopathological variable, suggesting that K-ras mutations are early events in the development of these tumors. Our results indicate that most, though not all, biphasic pleomorphic carcinomas of the lung are monoclonal in origin, and that cigarette smoking may have a causative role in the development of K-ras alterations in these tumors, as all mutations are transversions. 相似文献
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66.
Marta Zelazko Magda Carneiro-Sampaio Monica Cornejo De Luigi Diana Garcia De Olarte Oscar Porras Madrigal Renato Berrón Perez Agueda Cabello Marylin Valentin Rostan Ricardo U. Sorensen 《Journal of clinical immunology》1998,18(2):161-166
The Latin American Group for Primary Immunodeficiencies, formed in 1993, presently includes 12 countries. One goal was to study the frequency of primary immunodeficiencies in various regions of the American continent and to enhance knowledge about these diseases among primary-care physicians, as well as allergist–immunologists. Important for this purpose was the development of a registry of primary immunodeficiencies using a uniform questionnaire and computerized database. To date, eight countries have collected information on a total of 1428 patients. Predominantly antibody deficiencies were reported in 58% of patients, followed by cellular and antibody immunodeficiencies associated with other abnormalities in 18%, immunodeficiency syndromes associated with granulocyte dysfunction in 8%, phagocytic disorders in 9%, combined cellular and antibody immunodeficiencies in 5%, and complement deficiencies in 2% of patients. The information gathered from this initial analysis of data will serve to expand the patient database to more areas within participating countries and to new countries and to increase collaboration toward better diagnosis and treatment of these diseases. 相似文献
67.
Alessi N Freni MA Spadaro A Ajello A Turiano S Migliorato D Ferraù O 《Le infezioni in medicina : rivista periodica di eziologia, epidemiologia, diagnostica, clinica e terapia delle patologie infettive》2003,11(4):208-212
The aim of this study was to evaluate the efficacy and tolerability of interferon treatment in aged patients with chronic hepatitis C. One hundred and fifty-four patients with chronic hepatitis C, consecutively treated with a-interferon (a-IFN), were retrospectively subdivided into two groups according to age =60 or <60 years. The two groups were compared in terms of biochemical and histological activity of the disease, HCV genotype, total dose of IFN received, incidence of side effects and rate of response to treatment. Statistical analysis was performed by Student's t test, chi-square test and Fisher's exact test. Aged patients had a higher prevalence of HCV genotype 1b and cirrhosis and received a lower dose of the drug. No differences were found in other epidemiological-clinical characteristics before treatment. The rate of sustained response and long-term response to therapy was similar in the two groups of patients (18% and 8% in the aged and 20% and 13% in the younger respectively). There was a trend of more frequent major side effects in aged patients (p=0.07). Treatment of chronic hepatitis C with a-IFN had the same efficacy in the two groups observed. In aged patients with chronic hepatitis C treatment with the more effective pegylated IFN should be taken into consideration, especially when association with ribavirin is at high risk of adverse events. 相似文献
68.
Montes-Rodríguez CJ Alavez S Elder JH Haro R Morán J Prospéro-García O 《Neuroscience letters》2004,360(3):133-136
The human immunodeficiency virus (HIV) induces neuronal death, presumably by apoptosis. This effect may be triggered by the glycoprotein 120 (HIVgp120) released by HIV when infecting a cell, and mediated by tumor necrosis factor alpha (TNF), a pro-inflammatory cytokine. Both molecules, HIVgp120 and TNF, increase sleep when administered acutely in the brain. On the other hand, sleep deprivation increases the levels of several growth factors. In this context, we challenged rats with HIVgp120 or TNF simultaneously with sleep deprivation. Our results indicate that both HIVgp120 and TNF increase neuronal death in the rat cerebral cortex, but not hippocampus, and that this effect is completely prevented by total deprivation of sleep. These results suggest that acute total deprivation of sleep protects against the HIVgp120 and TNF deleterious effects. 相似文献
69.
Fernando de Ory José Manuel Echevarría George Kafatos Cleo Anastassopoulou Nick Andrews Josephine Backhouse Guy Berbers Blazena Bruckova Daniel I Cohen Hester de Melker Irja Davidkin Giovanni Gabutti Louise M Hesketh Kari Johansen Sari Jokinen Lindsay Jones Anika Linde Elisabeth Miller Jo?l Mossong Anthony Nardone Maria Cristina Rota Andreas Sauerbrei Fran?ois Schneider Zahava Smetana Annedore Tischer Athanassios Tsakris Robert Vranckx 《Journal of clinical virology》2006,36(2):111-118
BACKGROUND: The aim of the European Sero-Epidemiology Network (ESEN2) is to harmonise the serological surveillance of vaccine-preventable diseases in Europe. OBJECTIVE: To allow comparison of antibody prevalence in different countries by standardising results into common units. STUDY DESIGN: For varicella zoster virus (VZV), a reference laboratory established a panel of 148 samples, characterised by indirect enzyme-immunoassay (ELISA), indirect immunofluorescence, and complement fixation test. Fifty-seven samples were also studied by the fluorescence antibody to membrane antigen test. The geometric mean of the antibody activity (GMAA) obtained from four ELISA determinations was used to characterise each sample of the panel as positive (GMAA: >100 mIU/ml), equivocal (GMAA: 50-100 mIU/ml) or negative (GMAA: <50 mIU/ml) for antibody to VZV (anti-VZV). Thirteen laboratories, using five different ELISA tests, tested the panel. RESULTS: Agreement with the reference laboratory was above 85% in all cases, and the R(2) values obtained from regression analysis of the quantitative results were always higher than 0.87. Finally, the regression equations could be used to convert national values into a common unitage. CONCLUSION: This study confirmed that results for anti-VZV obtained by different ELISA methods can be converted into common units, enabling the comparison of the seroprevalence profiles obtained in the participant countries. 相似文献
70.
Pérez C Tous M Gallego S Zala N Rabinovich O Garbiero S Martínez MJ Cunha AM Camino S Cámara A Costa SC Larrondo M Francalancia V Landreau F Bartomioli MA 《Journal of medical virology》2004,72(4):661-667
Human herpesvirus-8 (HHV-8) causes Kaposi's sarcoma (KS) and lymphoproliferative disorders in both HIV-infected and uninfected patients. HHV-8 has a worldwide occurrence but infection rates vary according to a combination of geographic and behavioral risks. The main transmission route seems to be sexual, nevertheless, nasal secretions, saliva, blood, and organ graft have been proposed. HHV-8 was postulated as a new infectious agent for screening in blood donors. The aim of this study was to evaluate the prevalence of antibodies against HHV-8 antigens in blood donors of South America. Serum samples from 2,470 blood donors from Argentina, Brazil, and Chile corresponding to five geographic regions were studied by indirect immunofluorescence assay (IFA). Seroprevalence rate was 3.7% (92/2,470; 95% CI 2.9-4.5) in the entire blood donor population distributed as follows: Argentina, 4.0% (Buenos Aires city, 4.3%; Bahia Blanca, 2.4%; and Córdoba, 4.0%), Campinas (Brazil), 2.8%; and Santiago de Chile, 3.0%. There was no difference (P>0.05) between men and women or age related, except in Brazil where positive cases were 30-49-year-old males. The present study, which includes different geographical areas of multiple countries from South America, has not been done before. The results show similar prevalence rates among the studied zones corresponding to low-prevalence regions. South America is a large sub-continent with a wide spectrum of population and geographical characteristics, thus, more HHV-8 prevalence studies should be necessary to establish possible regional differences. 相似文献