Therapeutic drug monitoring and TB treatment outcomes in patients with diabetes mellitus

BACKGROUND: Diabetes mellitus (DM) increases the risk of TB disease and poor treatment outcomes such as delayed sputum culture conversion due to inadequate drug exposure. Therapeutic drug monitoring (TDM) has improved these outcomes in some settings.METHODS: To compare treatment outcomes in programs with routine TDM vs. programs that did not use TDM, we conducted a retrospective study among people with DM and TB at health departments in four US states.RESULTS: A total of 170 patients were enrolled (73 patients in the non-TDM group and 97 patients in the TDM group). Days to sputum culture conversion and total treatment duration were significantly shorter in the TDM group vs. the non-TDM group. In adjusted analyses, patients who underwent TDM were significantly more likely to achieve sputum culture conversion at 2 months (P = 0.007).CONCLUSION: TDM hastened microbiological cure from TB among people with DM and a high risk for poor treatment outcomes in the programmatic setting.

Tetrodotoxin blocks native cardiac L-type calcium channels but not CaV1.2 channels expressed in HEK cells

Tetrodotoxin (TTX) has been believed for a long time to be a selective inhibitor of voltage-gated fast Na(+) channels in excitable tissues, including mammalian myocardium. Recently TTX has been shown to block cardiac L-type Ca(2+) current (ICa,L). Furthermore, this inhibition was ascribed to binding of TTX to the outer pore of the Ca(2+) channel, contributing to the selectivity filter region. In this study the TTX-sensitivity of Cav1.2 channels, expressed in HEK cells, was tested using the whole cell version of the patch clamp technique and compared to the TTX-sensitivity of native canine ICa,L. Cav1.2 channels mediate Ca(2+) current in ventricular myocardium of various mammalian species. Surprisingly, TTX failed to inhibit Cav1.2 current up to the concentration of 100 μM - in contrast to ICa,L - in spite of the fact that the kinetic properties of the ICa,L and Cav1.2 currents were similar. The possible reasons for this discrepancy are discussed. Present results may question the suitability of a single pore-forming channel subunit, expressed in a transfection system, for electrophysiological or pharmacological studies.

The evolution of lymphadenopathy and hypergammaglobulinemia are evidence for early and sustained polyclonal B lymphocyte activation during human immunodeficiency virus infection

To examine whether polyclonal activation of B lymphocytes as measured by hypergammaglobulinemia contributes to lymphadenopathy in human immunodeficiency virus (HIV) infection, correlates of adenopathy were examined in 240 homosexual men. Lymph node size was measured in 12 sites semiannually over 4 years. Both adenopathy and hyperglobulinemia developed within 1 year after seroconversion and persisted at high levels. Adenopathy declined near diagnosis of AIDS whereas serum IgG decreased 8-16 months after diagnosis. Adenopathy attributable to HIV occurred in all palpable node groups. By logistic regression, HIV-positive men were best discriminated from HIV-negative men by size of posterior cervical nodes and the number of sites with enlarged nodes. In a repeated measures model of covariance, adenopathy in HIV-positive men was associated with more CD4+ cells (P less than .002), elevated serum globulins (P less than .01), and lower platelet counts (P less than .05). Adenopathy declined over time (P less than .001) and with diagnosis of AIDS or AIDS-related complex (P less than .03). Thus, adenopathy and hypergammaglobulinemia are correlated and follow a similar course through various stages of HIV infection, suggesting that both are caused by polyclonal B cell activation.

A controlled trial of early adjunctive treatment with corticosteroids for Pneumocystis carinii pneumonia in the acquired immunodeficiency syndrome. California Collaborative Treatment Group

BACKGROUND

Pneumocystis carinii pneumonia remains a common cause of serious morbidity and mortality in patients with the acquired immunodeficiency syndrome (AIDS). The extensive lung injury that accompanies pneumocystis-associated respiratory failure and the reports of clinical benefit from the use of adjunctive corticosteroids provided the rationale for this prospective multicenter trial.

METHODS

A total of 333 patients with AIDS and pneumocystis pneumonia received standard treatment and were randomly assigned to receive either corticosteroids (beginning with the equivalent of 40 mg of prednisone twice daily) or no additional therapy. The primary end points in this unblinded trial were the occurrence of respiratory failure (hypoxemia ratio [partial pressure of arterial oxygen divided by fraction of inspired oxygen] less than 75, intubation, or death), death, and dose-limiting toxicity of the initial standard therapy.

RESULTS

Of the patients with confirmed or presumed pneumocystis pneumonia (n = 225 and n = 26, respectively), those assigned to treatment with corticosteroids had a lower cumulative risk at 31 days of respiratory failure (0.14 vs. 0.30, P = 0.004) and of death (0.11 vs. 0.23, P = 0.009), as well as a lower risk of death within 84 days (0.16 vs. 0.26, P = 0.026). The frequency of dose-limiting toxicity of the standard therapy was similar in the two treatment groups. Intention-to-treat analyses of the entire cohort confirmed these findings. Clinical benefit could not be demonstrated, however, for patients with mild disease (hypoxemia ratio, greater than 350), equivalent to a partial pressure of oxygen greater than 75 torr on room air. The patients assigned to corticosteroid treatment had an excess of localized herpetic lesions (26 percent vs. 15 percent, P = 0.04) but not of other infections or of neoplasms.

CONCLUSIONS

Early adjunctive treatment with corticosteroids reduces the risks of respiratory failure and death in patients with AIDS and moderate-to-severe pneumocystis pneumonia. Because the adverse effects are few, corticosteroids should be included as part of the initial treatment for persons with AIDS who have moderate-to-severe pneumocystis pneumonia.

The association between cerebrovascular disease and smoking: a case-control study

A retrospective case-control study was carried out to examine the relationship between cigarette smoking and cerebrovascular disease occurrence. Cases were obtained from the University of California-American Heart Association, San Diego Stroke Data Bank, and controls from selected Veterans Administration and University of California, San Diego, outpatient departments. When cigarette smoking was dichotomously coded into categories of low and high lifetime exposure, consistent significant positive associations were found with cerebrovascular disease occurrence in both bivariate and multivariate analysis when controlling for blood pressure. These associations, however, were not found when smoking was categorized as smoker, ex-smoker, and non-smoker. No association was found between passive smoking and cerebrovascular disease. The results indicate that a cumulative lifetime exposure to active cigarette smoking is directly associated with cerebrovascular disease.