Meta-analysis of diagnostic procedures for Pneumocystis carinii pneumonia in HIV-1-infected patients.

Sputum induction is a simple and noninvasive procedure for Pneumocystis carinii pneumonia (PCP) diagnosis in human immunodeficiency virus-1-positive patients, although less sensitive than bronchoalveolar lavage (BAL). In order to obtain an overview of the diagnostic accuracy of sputum induction, a systematic review and meta-analysis of studies reporting the comparative sensitivity and specificity of BAL (the "gold standard") and sputum induction was performed. The odds ratio and related 95% confidence interval were calculated using summary receiving operating characteristic curves as well as fixed-effect and random-effect models. Based on pooled data, the negative and positive predictive values were calculated for a range of PCP prevalence using a Bayesian approach. Seven prospective studies assessed the comparative accuracy of BAL and sputum induction. On the whole, sputum induction demonstrated 55.5% sensitivity and 98.6% specificity. The sensitivity of sputum induction was significantly higher with immunofluorescence than with cytochemical staining (67.1 versus 43.1%). In settings of 25-60% prevalence of PCP, the positive and negative predictive values ranged 86-96.7 and 66.2-89.8, respectively, with immunofluorescence, and 79-94.4 and 53-83.5% with cytochemical staining. In conclusion, in a setting of low prevalence of Pneumocystis carinii pneumonia, sputum induction, particularly with immunostaining, appears to be adequate for clinical decision-making.

Interaction between levothyroxine and indinavir in a patient with HIV infection.

Drug interactions are an important and emerging problem in the treatment of HIV-infected patients. Protease inhibitors, like nonnucleoside reverse transcriptase inhibitors, are metabolized by the cytochrome P-450 enzyme system and each of these antiretroviral agents may interact with other drugs metabolized by this system. Some protease inhibitors may also interact with glucuronosyl transferase activity affecting plasma concentrations of drugs metabolized through this pathway. We describe a case of an HIV-infected patient, taking levothyroxine for hypothyroidism and clinically stable, who, after the introduction of an antiretroviral regimen containing indinavir, developed a pharmacological hyperthyroidism.

On the global stability of the logistic age-dependent population growth.

We study an age-dependent population equation with a nonlinear death rate of "logistic" type. The global asymptotic stability of the null solution is investigated when R(0) less than 1. If R(0) greater than 1 we get the existence of a nontrivial steady state that becomes asymptotically stable itself, while the null solution is unstable. The rate of decay is estimated.

Global asymptotic stability for a vector disease model with spatial spread.

We analyze the global behaviour of a vector disease model which involves spatial spread and hereditary effects. This model can be applied to investigate growth and spread of malaria. No immunization is considered. We prove that, if the recovery rate is less than or equal to a threshold value, the disease dies out, otherwise the infectious people density tends to a homogeneous distribution. Our results follow using contracting convexes techniques and agree with the results given by K. L. Cooke for the model without diffusion.