http://www.recercat.cat:80/handle/2072/48751 Sun, 19 May 2013 21:57:50 GMT 2013-05-19T21:57:50Z http://www.recercat.cat:80/bitstream/id/34121/ http://www.recercat.cat:80/handle/2072/48751 http://www.recercat.cat:80/handle/2072/210799 Modelling the Evolution and Spread of HIV Immune Escape Mutants. Fryer, H.R.; Frater, J.; Duda, A.; Roberts, M.G.; SPARTAC Trial Investigators, Phillips RE; McLean, A.R.; Pumarola Suñé, Tomás During infection with human immunodeficiency virus (HIV), immune pressure from cytotoxic T-lymphocytes (CTLs) selects for viral mutants that confer escape from CTL recognition. These escape variants can be transmitted between individuals where, depending upon their cost to viral fitness and the CTL responses made by the recipient, they may revert. The rates of within-host evolution and their concordant impact upon the rate of spread of escape mutants at the population level are uncertain. Here we present a mathematical model of within-host evolution of escape mutants, transmission of these variants between hosts and subsequent reversion in new hosts. The model is an extension of the well-known SI model of disease transmission and includes three further parameters that describe host immunogenetic heterogeneity and rates of within host viral evolution. We use the model to explain why some escape mutants appear to have stable prevalence whilst others are spreading through the population. Further, we use it to compare diverse datasets on CTL escape, highlighting where different sources agree or disagree on within-host evolutionary rates. The several dozen CTL epitopes we survey from HIV-1 gag, RT and nef reveal a relatively sedate rate of evolution with average rates of escape measured in years and reversion in decades. For many epitopes in HIV, occasional rapid within-host evolution is not reflected in fast evolution at the population level. http://www.recercat.cat:80/handle/2072/210799 http://www.recercat.cat:80/handle/2072/181405 Amyloid arthropathy in haemodialysed patients Muñoz Gómez, José; Solé Arqués, Manuel http://www.recercat.cat:80/handle/2072/181405 http://www.recercat.cat:80/handle/2072/180165 Clinical picture of the amyloid arthropathy in patients with chronic renal failure maintained on haemodialysis using cellulose membranes. Muñoz Gómez, José; Gómez-Pérez, R.; Llopart-Buisán, E.; Solé Arqués, Manuel The clinical picture of 15 patients (10 male, five female) with amyloid arthropathy secondary to chronic renal failure treated with haemodialysis has been studied. The average period of haemodialysis was 10.8 years. Joint symptoms appeared between three and 13 years after starting haemodialysis. No patient had renal amyloidosis. Early symptoms were varied and often overlapped: knee swelling (seven patients), painful and stiff shoulders (seven), and carpal tunnel syndrome (six) were the most prominent. Follow up showed extension to other joints. Joint effusions were generally of the non-inflammatory type. Radiologically, geodes and erosions of variable sizes were seen in the affected joints, which can develop into a destructive arthropathy. Amyloid was found in abdominal fat in three of the 12 patients on whom a needle aspiration was performed. Four of 12 patients showed changes compatible with amyloid infiltration in the echocardiogram. One patient had amyloid in the gastric muscular layer, another in the colon mucus, and two of four in rectal biopsy specimens. Amyloid deposits showed the presence of beta 2 microglobulin in 10 patients. The clinical and radiological picture was similar to the amyloid arthropathy associated with multiple myeloma. These patients can develop systemic amyloidosis. http://www.recercat.cat:80/handle/2072/180165 http://www.recercat.cat:80/handle/2072/180164 Synovial fluid examination for the diagnosis of synovial amyloidosis in patients with chronic renal failure undergoing haemodialysis Muñoz Gómez, José; Gómez-Pérez, R.; Solé Arqués, Manuel; Llopart-Buisán, E. The diagnosis of synovial amyloidosis is based upon synovial biopsy. Synovial fluid (SF) in seven patients with amyloid arthropathy associated with chronic renal failure undergoing haemodialysis were studied. The SF and synovial samples of 10 consecutive patients with seronegative mono- or oligoarthritis served as controls. Six of the seven patients with amyloid positive synovial biopsy specimens showed amyloid in their SF. No amyloid was found in the synovial tissue or fluid of the 10 patients in the control group, the sensitivity being 87.7%. The finding of amyloid in SF was highly reproducible, showing its presence in the same joint on several occasions. The deposits were Congophilia resistant to potassium permanganate pretreatment, and the immunohistochemical analysis proved that they contained beta 2 microglobulin. The high sensitivity and good reproducibility of the method shows that the finding of amyloid in SF is sufficient for the diagnosis of synovial amyloidosis. It is possible to perform immunohis http://www.recercat.cat:80/handle/2072/180164 http://www.recercat.cat:80/handle/2072/180163 Synovial fluid and amyloidosis Muñoz Gómez, José; Solé Arqués, Manuel http://www.recercat.cat:80/handle/2072/180163 http://www.recercat.cat:80/handle/2072/169273 Hepatitis G virus infection in chronic liver disease Guilera Sardà, Magda; Sáiz Calahorra, Juan Carlos; López Labrador, Francesc Xavier; Olmedo Casas, Eva; Ampurdanés, Sergi; Forns i Bernhardt, Xavier; Bruix Tudó, Jordi; Parés i Darnaculleta, Albert; Sánchez Tapias, José M. (José María); Jiménez de Anta Losada, María Teresa; Rodés, J. Background¿The hepatitis G virus (HGV), a recently identified member of the Flaviviridae family, can cause chronic infection in man but the role of this agent in chronic liver disease is poorly understood. Aims¿To evaluate the prevalence and meaning of HGV infection in a large series of patients with chronic liver disease. Subjects¿Two hundred volunteer blood donors, 179 patients with chronic hepatitis C, 111 with chronic hepatitis B, 104 with alcoholic liver disease, 136 with hepatocellular carcinoma, and 24 with cryptogenic chronic liver disease were studied. Methods¿HGV RNA was investigated in serum samples by reverse transcription and polymerase chain reaction amplification of the 5¿ non-coding region of HCV and hybridisation to a specific probe. The main features of HGV RNA seropositive and seronegative patients were compared. Results¿The prevalence of HGV infection was 3% in blood donors, 7% in chronic hepatitis C, 8% in chronic hepatitis B, 2% in alcoholic liver disease, 4% in hepatocellular carcinoma, and 8% in cryptogenic chronic liver disease. HGV infected patients tended to be younger than non-infected patients but no differences concerning sex, possible source of infection, clinical manifestations, biochemical and virological parameters, or severity of liver lesions were found. Conclusions¿The prevalence of HGV infection in chronic liver disease seems to be relatively low in our area. Infection with HGV does not seem to play a significant pathogenic role in patients with chronic liver disease related to chronic HBV or HCV infection or to increased alcohol consumption, or in those with cryptogenic chronic liver disease. http://www.recercat.cat:80/handle/2072/169273 http://www.recercat.cat:80/handle/2072/169272 Low dose alpha interferon therapy can be effective in chronic active hepatitis C. Results of a multicentre, randomised trial Forns i Bernhardt, Xavier; Ampurdanés, Sergi; Titó Espinagosa, Llúcia; Planas Vilà, Ramon; Viver i Pi-Suñer, Josep M.; Acero Fernández, Doroteo; Torres Salinas, Miguel; Mas, P.; Morillas Cunill, Rosa María; Forné Bardera, Montserrat; Espinós, J.; Llovet i Bayer, Josep Maria; Costa i Camps, Josep; Olmedo Casas, Eva; López Labrador, Francesc Xavier; Jiménez de Anta Losada, María Teresa; Rodés, J. BACKGROUND--There is some controversy concerning the efficacy of low dose alpha interferon therapy in chronic hepatitis C. AIMS--To evaluate the effectiveness of treatment with low doses of alpha interferon in chronic hepatitis C. PATIENTS--One hundred and forty one patients with anti-HCV positive chronic active hepatitis C from six hospitals were enrolled in the study. METHODS--Patients were randomised to treatment with 5 MU (group A) or 1.5 MU (group B) injections. The dose was reduced in responders from group A or increased in non-responders from group B to maintain treatment with the minimal effective dose. Patients were treated for 48 weeks and followed up for 24 additional weeks with no treatment. Normalisation of alanine aminotransferase (ALT) was used to evaluate response. RESULTS--A sustained response was seen in eight patients from group A (12%) and in 15 (21%) from group B. This difference was not statistically significant. Increasing the dose of interferon led to sustained response in only five of 58 patients (9%) from group B who did not respond to 1.5 MU injections. In contrast, 15 of 21 patients (71%) in whom ALT remained normal with 1.5 MU injections developed a sustained response. By multivariate analysis sustained response seemed associated with young age and was more frequent in patients with genotype 3 HCV infection. Sustained response was preceded by a rapid normalisation of ALT and was inversely related to the amount of alpha interferon necessary to maintain ALT at low values during treatment. CONCLUSIONS--Some patients with chronic hepatitis C are very sensitive to alpha interferon and can be successfully treated with low doses. Treatment with higher doses may be effective in a minority of patients who do not respond to low doses. http://www.recercat.cat:80/handle/2072/169272 http://www.recercat.cat:80/handle/2072/169117 Hepatitis G virus infection in fulminant hepatic failure Sáiz Calahorra, Juan Carlos; Sans i Cuffí, Miquel; Mas Comas, Ana M.; Olmedo Casas, Eva; Forns i Bernhardt, Xavier; López Labrador, Francesc Xavier; Restrepo Gutiérrez, Juan Carlos; Costa i Camps, Josep; Salmerón Bargo, Juan Manuel; Guilera Sardà, Magda; Ampurdanés, Sergi; Sánchez Tapias, José M. (José María); Jiménez de Anta Losada, María Teresa; Rodés, J. Background¿RNA sequences of the recently identified hepatitis GB virus C (HGBV-C), also named hepatitis G virus (HGV), have been detected in patients with idiopathic fulminant hepatic failure (FHF) but the role of this agent in the disease remains controversial. Aims¿To investigate the presence and implications of HGV infection in a large series of Spanish patients with FHF. Patients¿Sixty eight patients with FHF, including 19 with idiopathic disease, were studied. In 28 cases, studies were performed before and after liver transplantation. For comparison 200 volunteer blood donors and 22 patients transplanted for chronic liver disease were also studied. Methods¿HGV RNA was measured in serum by reverse transcriptase polymerase chain reaction of the 5' non-coding region. Results¿Evidence of HGV infection was found in 3% (6/200) of blood donors and in 19% (13/68) of patients with FHF. HGV infection was more frequent in patients with hepatitis B (24%, 6/25) or hepatitis D (42%, 5/12), than in patients with idiopathic disease (11%, 2/19). Half of the patients with HGV infection used illicit intravenous drugs. Specific clinical features associated with HGV infection were not identified. A very high rate of infection with HGV was observed in patients who underwent liver transplantation, either for FHF (60%, 15/24) or chronic liver disease (45%, 9/20). Conclusions¿In our geographical area, HGV infection is relatively frequent in FHF, but it does not seem to play a major role in idiopathic cases. http://www.recercat.cat:80/handle/2072/169117 http://www.recercat.cat:80/handle/2072/167000 Effects of prolonged ethanol intake and malnutrition on rat pancreas López Blanco, José Manuel; Bombí, Josep Antoni; Valderrama Labarca, Rodrigo; Giménez Lagunas, América; Parés i Darnaculleta, Albert; Caballeria Rovira, Joan; Imperial Ródenas, Santiago; Navarro Colás, Salvador Nutritional factors, especially the protein and fat content of the diet, may change pancreatic morphology after ethanol induced injury. This study was performed to delineate the combined effects of a low fat diet and longterm ethanol ingestion on the rat pancreas. Male Sprague-Dawley rats were maintained with five different diets for 12 weeks and the pancreas removed on the day they were killed. Rats fed a very low fat diet without ethanol (5% of total calories as lipid) developed malnutrition, pancreatic steatosis, and reduction in zymogen granules content. Animals fed a 35% lipid diet with ethanol also developed pancreatic steatosis but changes in zymogen granules content were not detected. Both malnutrition and longterm ethanol consumption increased pancreatic cholesterol ester content, and their effects were additive. Pancreatic steatosis was accompanied with hypercholesterolaemia. Amylase, lipase, and cholesterol esterase content were reduced in malnourished rats; but longterm ethanol ingestion, regardless of the nutritional state, increased lipase content and decreased amylase. It is suggested that high serum cholesterol concentrations and increased pancreatic lipase activity could cause accumulation of cholesterol esters in acinar cells. Fat accumulation in the pancreas has been reported as the earliest histopathological feature in alcoholic patients and may be responsible for cytotoxic effects on the acinar cells at the level of the cell membrane. Although it is difficult to extrapolate results in this animal study to the human situation, the results presented in this work might explain the higher incidence of pancreatitis is malnourished populations as well as in alcoholic subjects that is reported in dietary surveys. http://www.recercat.cat:80/handle/2072/167000 http://www.recercat.cat:80/handle/2072/49286 Satisfaction survey with DNA cards method to collect genetic samples for pharmacogenetics studies Vidal Taboada, Jose Manuel; Cucala, Mercedes; Mas Herrero, Sergi; Lafuente Fló, Amalia; Cobos Carbó, Alberto Background: Pharmacogenetic studies are essential in understanding the interindividual variability of drug responses. DNA sample collection for genotyping is a critical step in genetic studies. A method using dried blood samples from finger-puncture, collected on DNA-cards, has been described as an alternative to the usual venepuncture technique. The purpose of this study is to evaluate the implementation of the DNA cards method in a multicentre clinical trial, and to assess the degree of investigators' satisfaction and the acceptance of the patients perceived by the investigators.Methods: Blood samples were collected on DNA-cards. The quality and quantity of DNA recovered were analyzed. Investigators were questioned regarding their general interest, previous experience, safety issues, preferences and perceived patient satisfaction. Results: 151 patients' blood samples were collected. Genotyping of GST polymorphisms was achieved in all samples (100%). 28 investigators completed the survey. Investigators perceived patient satisfaction as very good (60.7%) or good (39.3%), without reluctance to finger puncture. Investigators preferred this method, which was considered safer and better than the usual methods. All investigators would recommend using it in future genetic studies. Conclusion: Within the clinical trial setting, the DNA-cards method was very well accepted by investigators and patients (in perception of investigators), and was preferred to conventional methods due to its ease of use and safety. http://www.recercat.cat:80/handle/2072/49286 http://www.recercat.cat:80/handle/2072/49285 Platelet activation in mice and human Helicobacter pylori infection. Elizalde, J. I.; Gómez, Julià; Panés Díaz, Julián; Lozano, Miquel; Casadevall Munné, Maria; Ramírez, Josep; Pizcueta Lalanza, María Pilar; Marco, Francesc; Díaz de Rojas, Francisco; Granger, D. Neil; Piqué, J. M. Extracts of Helicobacter pylori (HP) have been shown to induce leukocyte adhesion in mesenteric venules, but the effects of HP infection on gastric microvessels are unknown. Inflammatory cell interactions in the gastric microcirculation were studied by intravital videomicroscopy in mice inoculated with either saline or fresh isolates of HP. Platelet aggregates were detected and quantified in murine portal blood, while endothelial P-selectin expression was determined using the dual radiolabeled mAb technique. Platelet activation and aggregation were studied in HP-infected patients and controls by measuring the platelet-aggregate ratio and platelet P-selectin expression. HP infection induced a marked increase in the flux of rolling leukocytes and the appearance of platelet and leukocyte- platelet aggregates in murine gastric venules. The HP-induced rolling and platelet aggregate formation was abrogated by mAbs against L- or P-, but not E- selectin. Endothelial cell expression of P-selectin was not altered, but platelet P-selectin expression was enhanced in HP-infected mice. Circulating platelet aggregates and activated platelets were also detected in HP-infected patients. These findings indicate that platelet activation and aggregation contribute to the microvascular dysfunction and inflammatory cell recruitment associated with HP infections. http://www.recercat.cat:80/handle/2072/49285 http://www.recercat.cat:80/handle/2072/49284 Hereditary hepatic and systemic amyloidosis caused by a new deletion/insertion mutation in the apolipoprotein AI gene. Booth, David R.; Tan, Si-Yen; Booth, Sussanne E.; Tennent, Glenys A.; Hutchinson, Winston L.; Hsuan, J. Justin; Totty, Nicholas F.; Truong, Oanh; Soutar, Anne K.; Hawkins, Philip N.; Bruguera i Cortada, Miquel, 1942-; Caballeria Rovira, Joan; Solé, Manel; Campistol Plana, Josep Ma.; Pepys, Mark B. We report a Spanish family with autosomal-dominant non-neuropathic hereditary amyloidosis with a unique hepatic presentation and death from liver failure, usually by the sixth decade. The disease is caused by a previously unreported deletion/insertion mutation in exon 4 of the apolipoprotein AI (apoAI) gene encoding loss of residues 60-71 of normal mature apoAI and insertion at that position of two new residues, ValThr. Affected individuals are heterozygous for this mutation and have both normal apoAI and variant molecules bearing one extra positive charge, as predicted from the DNA sequence. The amyloid fibrils are composed exclusively of NH2-terminal fragments of the variant, ending mainly at positions corresponding to residues 83 and 92 in the mature wild-type sequence. Amyloid fibrils derived from the other three known amyloidogenic apoAI variants are also composed of similar NH2-terminal fragments. All known amyloidogenic apoAI variants carry one extra positive charge in this region, suggesting that it may be responsible for their enhanced amyloidogenicity. In addition to causing a new phenotype, this is the first deletion mutation to be described in association with hereditary amyloidosis and it significantly extends the value of the apoAI model for investigation of molecular mechanisms of amyloid fibrillogenesis. http://www.recercat.cat:80/handle/2072/49284 http://www.recercat.cat:80/handle/2072/49283 Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data Lozano, Juan José; Soler, Marta; Bermudo, Raquel; Abia, David; Fernández Ruiz, Pedro Luis; Thomson, Timothy M.; Ortiz, Angel R. Background: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. Results: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. Conclusion: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer. http://www.recercat.cat:80/handle/2072/49283