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Biomedical subjects

M Barrios

Publications and source records attributed to M Barrios.

At least 19 recordsLinked to original sources
PubMed2005

Reliable quantification of hematopoietic chimerism after allogeneic transplantation for acute leukemia using amplification by real-time PCR of null alleles and insertion/deletion polymorphisms.

Increasing mixed chimerism (MC) after allogeneic stem cell transplantation (SCT) has been associated with a high risk of relapse in acute leukemia. We evaluated a new method for chimerism detection, based on the quantitative real-time PCR (qrt-PCR) amplification of null alleles or insertion/deletion polymorphisms (indels). All qrt-PCR assays with null alleles and indels attained a sensitivity of at least 10(-4), as well as good intra- and interassay concordance, and a high accuracy in experiments with cell mixtures. Informativeness was found in 80.3% of the 61 donor/recipient pairs tested. Nonrelapsed patients showed a progressive decrease in peripheral blood chimerism to values below 0.01% (complete chimerism (CC)). Bone marrow chimerism failed to reach CC more than 4 years after SCT. Increasing MC was observed prior to relapse in 88.2% of patients. Compared with conventional PCR amplification of variable number of tandem repeats, qrt-PCR predicted a significantly higher number of relapses (88.2 vs 44.4%) with a median anticipation period of 58 days. In conclusion, chimerism determination by qrt-PCR amplification of null alleles and indels constitutes a useful tool for the follow-up of patients with acute leukemia after SCT, showing better results than those obtained with conventional PCR.

Adolescent↗
PubMed2004

Transcriptional silencing of the Dickkopfs-3 (Dkk-3) gene by CpG hypermethylation in acute lymphoblastic leukaemia.

DKK-3: is a newly characterised mortalisation-related gene and an antagonist of the Wnt oncogenic signalling pathway whose expression is decreased in a variety of cancer cell lines, suggesting that the Dkk-3 gene, located at chromosome 11p15.1, functions as a tumour suppressor gene. Although 11p15 is a 'hot spot' for methylation in acute lymphoblastic leukaemia (ALL), the role of Dkk-3 abnormalities has never been evaluated in this disease. We analysed CpG island methylation of the Dkk-3 promoter in six ALL cell lines and 183 ALL patients. We observed Dkk-3 hypermethylation in all cell lines and in cells from 33% (60/183) of ALL patients. Moreover, Dkk-3 methylation was associated with decreased Dkk-3 mRNA expression and this expression was restored after exposure to the demethylating agent 5-AzaC. Clinical features did not differ between hypermethylated and unmethylated patients. Estimated disease-free survival (DFS) and overall survival at 10 and 11 years, respectively, were 49.8 and 45.6% for normal patients and 10.5 and 15.1% for hypermethylated patients (P=0.001 and 0.09). Multivariate analysis demonstrated that Dkk-3 methylation was an independent prognostic factor predicting DFS (P=0.0009). Our data suggest that Dkk-3 methylation occurs at an early stage in ALL pathogenesis and probably influences the clinical behaviour of the disease.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Febrile pancytopenia and psychosis revealing pernicious anemia.

The rare case of a 42-year-old woman of African origin presenting with persecution mania leading to admission to a psychiatric hospital is reported. The outcome was rapidly marked by febrile pancytopenia and ataxia leading to the diagnosis of pernicious anemia. Although the hematologic abnormalities and mania were corrected within 2 weeks under vitamin therapy, neural improvement was slower as observed classically. The literature regarding pancytopenia and psychiatric presentations is briefly reviewed, suggesting that vitamin B(12) deficiency may induce paranoid delusion.

Adult↗
PubMed2001

Parovirus B19 infection in an HIV-infected patient with febrile pancytopenia and acute hepatitis.

The case of a 34-year-old male patient with HIV infection referred for severe febrile pancytopenia is reported. Clinical and laboratory evaluations revealed acute hepatitis B infection and concomitant parvovirus B19 infection. The patient died just before treatment with immune globulin was to be administered. Parvovirus B19 has been found to cause a wide variety of hematologic disorders such as neutropenia, thrombocytopenia, pancytopenia, and hemophagocytic syndrome. The role of parvovirus B19 in the pathogenesis of bone marrow or liver involvement is briefly discussed.

Acute Disease↗
PubMed2001

Bovine immunodeficiency virus in experimentally infected rabbit: tropism for lymphoid and nonlymphoid tissues.

The bovine immunodeficiency virus (BIV)/New Zealand (Oryctolagus cuniculus) rabbit model was used to study events that underlie the early and chronic stages of viral replication, routes and time course of viral dissemination and the distribution of the virus in the lymphoid. nonlymphoid and mucosa associated tissues. The results indicated that BIV, a lentivirus with genetic relatedness to the HIV, induced changes of clinical (anorexia, weight loss, muscular wasting, diarrhea, hypoalgesia, torticollis), immunological (recurrent T- and B-cell dysfunctions) and histopathological (lymphadenopathy, splenomegaly) nature that closely parallels those described for cat (Fly), monkey (SIV) and human (HIV) lentiviral diseases. These findings showing that BIV induces both splenomegaly and lymphadenopathy syndromes with associated fatal immune dysfunctions and the ability of the virus to replicate productively at the mucosal surfaces in rabbits, emphasize the importance of the BIV/rabbit system as a good small-animal model for the study of retrovirus-induced AIDS and offers the opportunity to evaluate prophylactic and therapeutic anti-retroviral agents of relevance to HIV-1 as well as the opportunity to study mechanisms of drug resistance phenomena.

Animals↗
PubMed2001

Hypermethylation of the calcitonin gene in acute lymphoblastic leukaemia is associated with unfavourable clinical outcome.

We analysed calcitonin (CALC1) gene hypermethylation using semiquantitative differential polymerase chain reaction in 105 patients with adult (n = 49) and childhood (n = 56) acute lymphoblastic leukaemia (ALL), and studied the association of CALC1 hypermethylation with clinical presentation features and disease outcome. We also investigated the possible relationship between CALC1 methylation status and expression of the cell cycle inhibitor gene p57KIP2. We observed CALC1 hypermethylation in bone marrow cells from 43% (45 out of 105) of ALL patients. Clinical, molecular and laboratory features did not differ significantly between hypermethylated and hypomethylated patients, only T-cell lineage was associated with hypermethylation (14% vs. 47%, P = 0025). Complete remission rate was similar in both groups although hypermethylated patients had a higher relapse rate (68% vs. 19%, P < 0.00001) and mortality rate (55% vs. 36%, P = 0.06) than hypomethylated patients. Estimated disease-free survival (DFS) at 6 years was 66.1% for hypomethylated patients and 5.3% for hypermethylated patients (P < 0,00001). Multivariate analysis from potential prognostic factors demonstrated that CALC1 methylation status was an independent prognostic factor in predicting DFS (P = 0.0001). Separate analysis of adult and childhood ALL patients showed similar results to the whole series. In addition, hypermethylated patients showed downregulation of p57KIP2 expression. Our results suggest that CALC1 gene hypermethylation is associated with an enhanced risk of relapse independently of known poor-prognostic factors and we describe, for the first time, a possible implication of the p57KIP2 gene in the genesis and prognosis of ALL.

Adult↗
PubMed2001

E1A3 as a unique, naturally occurring BCR-ABL transcript in an indolent case of chronic myeloid leukaemia.

A woman with Ph-positive chronic myeloid leukaemia (CML) with an atypical e1a3 BCR-ABL hybrid gene is described. To our knowledge, this is the first report of this transcript type as a unique naturally occurring BCR-ABL fusion in a CML patient. This case was characterized by a low leucocyte count and a very indolent course without treatment. Because the deletion of ABL exon 2 sequences results in deletion of an essential part of the ABL SH3 domain, our case suggests that this ABL SH3 domain is not absolutely necessary for efficient induction of a myeloproliferative disease in the context of BCR-ABL/p190.

Aged↗
PubMed2001

Correlation of atrophy measures on MRI with neuropsychological sequelae in children and adolescents with traumatic brain injury.

To examine the relationship between neuropsychological sequelae and atrophy parameters from magnetic resonance imaging (MRI) following paediatric moderate-to-severe traumatic brain injury (TBI), 19 head injured children and adolescents were studied at least 6 years after injury. Three-dimensional MRI scans were obtained. A semi-automatic computerized method was used to estimate ventricular volumes and the corpus callosum area. Tests of intellectual, memory, visuospatial, frontal lobe, and motor speed functioning were administered to all patients and to 19 matched normal control subjects. Patients' performance significantly differed from controls in general intellectual function, visual memory, visuospatial and frontal lobe tests. The corpus callosum area correlated strongly with several measures involving processing speed and visuospatial function. Ventricular enlargement was less related to neuropsychological outcome. In conclusion, quantitative measurement of the corpus callosum on MRI reflects neuropsychological outcome better than ventricular dilation in paediatric patients.

Adolescent↗
PubMed2001

The role of copper suppression as an antiangiogenic strategy in head and neck squamous cell carcinoma.

OBJECTIVE: To determine whether tetrathiomolybdate (TM), a powerful chelator of copper, is capable of lowering the body stores of copper and suppressing the growth of head and neck squamous cell carcinoma in an orthotopic murine model. STUDY DESIGN: In vivo, murine model. METHODS: Twelve 8-week-old male C3H/HeJ mice were assigned to either a TM treatment group (n = 7) or a control group (n = 5). Serum samples were obtained from a single mouse in each group to measure the level of ceruloplasmin as a surrogate marker of total body copper on days 0, 4, and 7. Mice in both groups received a floor-of-mouth injection of 1.5 x 105 SCC VII/SF cells. After 7 to 10 days of tumor growth the treatment group received fresh water daily, to which TM was added to achieve an oral intake of 50 mg per mouse. The control group received only fresh drinking water daily. Tumor volume measurements were obtained every other day. Microvessel density counts were assessed in the tumors by Factor VIII analysis. RESULTS: Measurable tumor growth was achieved in 100% of the mice by the tenth day. Total body copper was reduced by 28% from baseline levels in mice in the treatment group. The difference in mean tumor volume in the control group was 4.7 times greater than the TM-treated group at the completion of treatment (3004 mm3 and 633mm3, respectively). This accounted for an overall suppression rate of 79% (P =.008; two-tailed Student t test). In addition, microvessel density was reduced by 50% in the TM-treated group. CONCLUSION: In this initial study, the first of its kind in head and neck squamous cell carcinoma, we have demonstrated the ability of TM to significantly suppress both the growth of squamous cell carcinoma and tumor vascularity in this orthotopic murine model, suggesting its potential for efficacy in the treatment of this disease in humans.

Angiogenesis Inhibitors↗
PubMed2001

Angiosarcoma variant of Kasabach-Merritt syndrome.

Kasabach-Merritt syndrome is characterized by the occurrence of disseminated intravascular coagulation (DIC) usually caused by benign angiomatous tumours. Here we report the case of a 70-year-old man in whom DIC revealed a locally advanced hepatic tumour. Although DIC resolved with heparin, antithrombin III, fresh frozen plasma and corticosteroids, the patient died from haemoperitoneum following a fall, 3 months after the initial observation. Histopathological examination by autopsy allowed the diagnosis of hepatic angiosarcoma. The physiopathogenic mechanisms and treatment options are discussed.

Aged↗
PubMed2000

Detection of genetic diversity among bovine immunodeficiency virus population by single-strand conformation polymorphism analysis.

Serial virus specimens rescued from rabbits, experimentally infected with bovine immunodeficiency (BIV) strain R29, were monitored for changes in quasispecies population, using the single-strand conformation polymorphism (SSCP) analysis. The generation of characteristic SSCP patterns enables the rapid differentiation of BIV variants derived from the conserved part on the env region of the BIV genome, reducing the need for expensive and time-consuming direct sequencing analyses. Our results showed genetic polymorphism among a number of sampled BIV population in experimentally infected rabbits. At least three SSCP patterns (BIV quasispecies) were detected. The SSCP analysis allows for an easy, sensitive, and rapid screening of genetic variants of the virus and the assessment of variation at a number of tissue target sites. These variations may relate to cell-type targets and/or disease progression, and could be significant to our understanding of lentiviral pathogenesis.

Animals↗
PubMed1999

Emotional state of patients with relapsing-remitting MS treated with interferon beta-1b.

BACKGROUND: Depression has been cited as a possible side effect of interferon beta-1b (IFNbeta-1b) therapy in patients with MS. This association remains unproven because of a lack of longitudinal studies. OBJECTIVE: To determine the changes in emotional state in relapsing-remitting (RR) MS patients during the first 2 years of treatment with IFNbeta-1b. METHODS: Emotional state was evaluated in a sample of 90 patients at the onset of IFNbeta-1b treatment during an inclusion period of 2.5 years. Seventy-five patients were evaluated at their 12th month of treatment and 56 patients at their 24th month. We assessed their emotional state with the following psychological tests: Hamilton Depression Rating Scale, Beck Depression Inventory, and State-Trait Anxiety Inventory. RESULTS: We found significant improvement in emotional state after the first and second years of treatment. CONCLUSIONS: Our findings show that IFNbeta-1b does not increase depression or anxiety in RR MS patients during the first and second years of IFNbeta-1b treatment. In fact, slight but significant improvement in depression and anxiety symptoms was observed during this period.

Female↗