Hypervirulence of a rough variant of the Mycobacterium abscessus type strain

We isolated a rough variant of Mycobacterium abscessus CIP 104536T during experimental infection of mice. We show that this variant has lost the ability to produce glycopeptidolipids, is hyperlethal for C57BL/6 mice infected intravenously, and induces a strong tumor necrosis factor-alpha response by murine monocyte-derived macrophages.

The effect of acenocoumarol on hemorheological parameters

The effect of acenocoumarol on hemorheological variables was measured in 35 non-valvular chronic atrial fibrillation patients before starting oral anticoagulant therapy (basal) and one and two months after beginning treatment (INR-2,3). Fibrinogen increased significantly from the basal situation: 332+/-99 mg/dl to 386+/-96 mg/dl in the second month (p<0.05). However, this small increase in fibrinogen is not large enough to mediate other rheological changes, and whole blood filterability, blood viscosity, plasma viscosity and erythrocyte deformability and aggregability remained unchanged after treatment. These results suggest that acenocoumarol does not affect rheological parameters and can therefore be used as a "neutral drug" for rheological studies in cardiovascular patients under oral anticoagulant therapy.

Spontaneous cervical epidural hematoma associated with oral anticoagulant therapy

A 54-year-old woman who was on anticoagulant treatment with acenocoumarol for a mitral prothesis developed a cervical spinal epidural hematoma, probably triggered by coughing fits together with supratherapeutic anticoagulation. Because of the subacute evolution of the hematoma, it was not diagnosed until the patient was admitted to the hospital with profuse hemorrhages. Given the subacute nature of the hematoma, along with the favorable evolution, conservative treatment with dexamethasone was decided upon, and it was resolved with almost no sequelae. This unusual clinical entity definitely should be suspected in patients on anticoagulants who complain of severe localized neck pain, most often with radicular irradiation.

Comparative study of a portable prothrombin time monitor employing three different systems in oral anticoagulant units

The aim of this study was to evaluate the accuracy of the portable coagulometer CoaguChek (Roche Diagnostics) as a prothrombin time (PT) monitor, and to correlate capillary blood results with those of three different routine methods used for monitoring oral anticoagulant therapy (OAT): capillary, plasma and whole blood samples. Three hospitals participated in the study with a total of 235 patients on OAT. The international normalized ratio (INR) results obtained with CoaguChek were compared with those obtained using each of the routine methods. The study presents a good correlation between the PT monitor and the three methods studied: r = 0.9745 (hospital A), r = 0.9283 (hospital B), r = 0.9136 (hospital C). A simplified concordance test of the methods results in a nine-field comparison table showing concordances of 87.2, 85.7 and 68.4%, respectively. The absolute difference (mean +/- SD) between laboratory A and CoaguChek INRs was 0.0571 +/- 0.2042, with values of 0.04286 +/- 0.3906 for laboratory B and 0.6986 +/- 0.6170 for laboratory C. These results confirm that CoaguChek could be used as a new method for oral anticoagulant monitoring, and is in best agreement with the capillary blood PT system.

Heterogeneous lack of expression of the tumour suppressor PTEN protein in human neoplastic tissues

PTEN, a tumour suppressor gene located at chromosome 10q23 and commonly mutated or deleted in a variety of tumours, encodes a dual-specific/phosphatidylinositol-3,4,5-triphosphate (PIP3) phosphatase. We report the generation of an anti-PTEN monoclonal antibody (MAb) that recognises an epitope at the C-terminus of PTEN, and describe the heterogeneous lack of expression of the PTEN protein in human tumour tissues, as demonstrated by immunohistochemical methods. Our anti-PTEN MAb provides a useful tool for the study of PTEN protein expression in tumour samples, in the search for tumour prognostic molecular markers.

Genetic alterations and oxidative metabolism in sporadic colorectal tumors from a Spanish community

Deletions of loci on chromosomes 5q, 17p, 18q, and 22q, together with the incidence of p53 mutations and amplification of the double minute-2 gene were investigated in the sporadic colorectal tumors of 44 patients from a Spanish community. Chromosome deletions were analyzed by means of loss of heterozygosity analysis using a restriction fragment length polymorphism assay. Allelic losses were also detected by polymerase chain reaction (PCR)-single-stranded conformation polymorphism (SSCP) analysis of a polymorphic site in intron 2 of the p53 gene. The percentages of genetic deletions on the screened chromosomes were 39.3% (5q), 58.3% (17p), 40.9% (18q), and 40% (22q). Mutations in p53 exons 2-9 were examined by PCR-SSCP analysis and direct sequencing of the mutated region. Twenty of 44 tumor samples (45.45%) showed mutations at various exons except for exons 2, 3, and 9, the most frequent changes being G-->T transversion and C-->T transition. Because oxygen-free radicals play a role in the carcinogenesis process, we evaluated the oxidative status of the colorectal tumors. Antioxidant activities, lipid peroxidation, and DNA-damaged product concentrations in colon tumors and normal mucosa were compared. In tumor tissues, superoxide dismutase and catalase decreased fourfold and twofold, respectively, whereas glutathione peroxidase and reduced glutathione increased threefold. Malondialdehyde and 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were twofold higher in colorectal tumors than in normal mucosa. Seven of 10 DNA tumor samples (70%) showing higher values of 8-OHdG also had genetic alterations at different chromosomal loci. In these samples, the p53 gene was deleted or mutated in 71.4% of cases. We concluded that the observed changes in the oxidative metabolism of the tumor cells and the consecutive increase in DNA damage may potentiate the genomic instability of different chromosomal regions, leading to further cell malignancy and tumor expansion.