No abstract

The performance of an ELISA for detection of total antibodies to Brucella spp. was compared with that of the Rose Bengal, standard agglutination and Coombs test in the diagnosis of brucellosis. Sera tested were from 208 patients from whom Brucella melitensis had been isolated, 177 patients with significant results in at least two conventional tests, and 107 patients with fever from whom no Brucella spp. had been isolated and in whom all conventional tests were negative. ELISA was the most sensitive test (97%), showing greater specificity (96%) and good predictive positive and negative values (98% and 94% respectively). ELISA was the only positive test in 6% of patients in whom brucellosis had been confirmed by culture.

Sera from 65 patients with upper gastrointestinal tract symptoms and proven Helicobacter pylori infection, and from 42 negative controls were tested with two commercial EIAs (GAP test, BioRad; and ECP test, Biometra) and two non-commercial EIAs, one performed with whole sonicated cells and the other with acid extract of Helicobacter pylori as antigen. The GAP assay showed a sensitivity of 83.1% and a specificity of 47.6%. The ECP assay showed a sensitivity of 87.7% and a specificity of 61.9%. For both non-commercial EIAs these figures were 87.7% and 88.1%, respectively. Independent of the interpretive criteria established by the manufacturers, receiver operating characteristic curves were plotted for better evaluation of the four methods. Both commercial tests showed a lower probability of yielding a correct diagnosis than the non-commercial tests (p less than 0.05). Although commercial EIAs are convenient for the diagnosis of Helicobacter pylori infection, the accuracy of the two commercial tests evaluated in this study was lower compared to that of the two non-commercial EIAs.

Aspirin protects from cardiovascular events because of its antiaggregant effect. The occurrence of new events in patients who take aspirin has been called clinical aspirin resistance. Many authors believe that aspirin resistance must be detected by biochemical tests, although there is no agreement on which is the best. Nor is there agreement on the term aspirin resistance. Tests used in research laboratories are aggregometry (turbidometric and impedance), tests based on activation-dependent changes in platelet surface, and tests based on activation-dependent release from platelets. Point-of-care tests are PFA-100, IMPACT and VerifyNow, which can detect platelet dysfunction that may be due to aspirin effect, but their use for this purpose is not yet recommended. Aspirin response may be modified by different factors: patient's compliance, dose, smoking, hyperlipidemia, hyperglucemia, acute coronary syndrome, percutaneous revascularization, recent stroke, extracorporeal circulation, heart failure, exercise, circadian rhythm, absorption, concomitant medications, polymorphisms. Patients with aspirin resistance may have an increased risk of cardiovascular events, and possible therapeutic options are to increase the dosage, to replace aspirin with another antiaggregant drug or to add another drug. In conclusion, there are many reasons that explain the variability in individual responsiveness to aspirin. The term resistance is probably not exact in describing this phenomenon.

La miocardiopatía hipertrófica es una afectación cardiaca, no infrecuente, caracterizada por la hipertrofia asimétrica del ventrículo izquierdo. Presenta una gran heterogenicidad tanto clínica como morfológica. En este trabajo repasamos los aspectos etiológicos, fisiopatológicos, clínicos, terapéuticos y pronósticos de esta enfermedad, haciendo hincapié en los logros alcanzados y los retos aún pendientes.