Effect of antituberculosis drug resistance on response to treatment and outcome in adults with tuberculous meningitis

BACKGROUND: Tuberculous meningitis (TBM) caused by Mycobacterium tuberculosis resistant to 1 or more antituberculosis drugs is an increasingly common clinical problem, although the impact on outcome is uncertain. METHODS: We performed a prospective study of 180 Vietnamese adults admitted consecutively for TBM. M. tuberculosis was cultured from the cerebrospinal fluid (CSF) of all patients and was tested for susceptibility to first-line antituberculosis drugs. Presenting clinical features, time to CSF bacterial clearance, clinical response to treatment, and 9-month morbidity and mortality were compared between adults infected with susceptible and those infected with drug-resistant organisms. RESULTS: Of 180 isolates, 72 (40.0%) were resistant to at least 1 antituberculosis drug, and 10 (5.6%) were resistant to at least isoniazid and rifampicin. Isoniazid and/or streptomycin resistance was associated with slower CSF bacterial clearance but not with any differences in clinical response or outcome. Combined isoniazid and rifampicin resistance was strongly predictive of death (relative risk of death, 11.63 [95% confidence interval, 5.21-26.32]) and was independently associated with human immunodeficiency virus infection. CONCLUSIONS: Isoniazid and/or streptomycin resistance probably has no detrimental effect on the outcome of TBM when patients are treated with first-line antituberculosis drugs, but combined isoniazid and rifampicin resistance is strongly predictive of death.     

Risk Factors for Asthma and Other Allergic Diseases in Seasonal Rhinitis

Background. Rhinitis and asthma are common comorbidities. The aim of this study was to determine the risk factors for asthma and other allergic diseases in seasonal rhinitis (SR) patients. Methods. Records of 922 patients diagnosed as SR between 1991 and 2005 were evaluated retrospectively. Patients were grouped according to the results of our standard skin prick tests as follows: I-No sensitization: no sensitization to any allergen; II-Mono-pollen sensitization: sensitization to only one pollen allergen; III-Poly-pollen sensitization: sensitization to more than one pollen allergen; IV-Mite sensitization: sensitization to mite with or without any other allergen sensitization. Results. The mean age of the patients was 29.5 ± 9.6 and 587 patients (63.2%) were females. Age at onset of SR was median 21 years (16–29 years). Of the 922 patients, 99 had no sensitization, 335 had poly-pollen sensitization, 346 had mono-pollen sensitization, and 142 had mite sensitization. The most prevalent allergens were P. pratense (85.3%) and O. europae (31.5%). No sensitization group as compared to poly-pollen sensitization group had significantly higher prevalence of asthma as a single accompanying disease (14.1%, p < 0.05). Mono-pollen sensitization was significantly associated with lower risk of any accompanying allergic disease (OR: 0.7, 95% CI 0,5–0,9) while no sensitization group (OR: 2.8, 95% CI 1.3–5.9) and mite sensitization were associated with asthma (OR: 2.3, 95% CI 1.2–4.4). Conclusion. SR is a condition that presents with different phenotypes. The group with no sensitization and mite sensitization has the highest prevalence of asthma while SR patients with mono-pollen sensitization are unlikely to have an accompanying allergic disease, including asthma.     

Localization of lipoprotein lipase in the diabetic heart: regulation by acute changes in insulin.

Vascular endothelium-bound lipoprotein lipase (LPL) is rate limiting for free fatty acid (FFA) transport into tissues. In streptozotocin (STZ)-diabetic rats, we have previously demonstrated an increased heparin-releasable LPL activity from perfused hearts. Because heparin can traverse the endothelial barrier, conventional Langendorff retrograde perfusion of the heart with heparin could release LPL from both the capillary luminal and abluminal surfaces. To determine the precise location of the augmented LPL, a modified Langendorff retrograde perfusion was used to isolate the enzyme at the coronary lumen from that in the interstitial effluent. In response to heparin, a 4-fold increase in LPL activity and protein mass was observed in the coronary perfusate after 2 weeks of STZ diabetes. Release of LPL activity into the interstitial fluid of control hearts was slow but progressive, whereas in diabetic hearts, peak enzyme activity was observed within 1 to 2 minutes after heparin, followed by a gradual decline. Immunohistochemical studies of myocardial sections confirmed that the augmented LPL in diabetic hearts was mainly localized at the capillary endothelium. To study the acute effects of insulin on endothelial LPL activity, we examined rat hearts at various times after the onset of hyperglycemia. An increased heparin-releasable LPL activity in diabetic rats was demonstrated shortly (6 to 24 hours) after STZ injection or after withdrawal from exogenous insulin. Heparin-releasable coronary LPL activity was also increased after an overnight fast. These studies indicate that the intravascular heparin-releasable fraction of cardiac LPL activity is acutely regulated by short-term changes in insulin rather than glucose. Thus, during short periods (hours) of hypoinsulinemia, increased LPL activity at the capillary endothelium can increase the delivery of FFAs to the heart. The resultant metabolic changes could induce the subsequent cardiomyopathy that is observed in the chronic diabetic rat.     

Transposition of the Great Arteries in the Developing World: Surgery and Outcomes

Background

Little has been published regarding surgery for transposition of the great arteries (TGA) in the developing world.

Hepatic gene expression during treatment with peginterferon and ribavirin: Identifying molecular pathways for treatment response

The reasons for hepatitis C treatment failure remain unknown but may be related to different host responses to therapy. In this study, we compared hepatic gene expression in patients prior to and during peginterferon and ribavirin therapy. In the on-treatment group, patients received either ribavirin for 72 hours prior to peginterferon alpha-2a injection or peginterferon alpha-2a for 24 hours, prior to biopsy. The patients were grouped into rapid responders (RRs) with a greater than 2-log drop and slow responders (SRs) with a less than 2-log drop in hepatitis C virus RNA by week 4. Pretreatment biopsy specimens were obtained from a matched control group. The pretreatment patients were grouped as RRs or SRs on the basis of the subsequent treatment response. Gene expression profiling was performed with Affymetrix microarray technology. Known interferon-stimulated genes (ISGs) were induced in treated patients. In the pretreatment group, future SRs had higher pretreatment ISG expression than RRs. On treatment, RRs and SRs had similar absolute ISG expression, but when it was corrected for the baseline expression with the pretreatment group, RRs showed a greater fold change in ISGs, whereas SRs showed a greater change in interferon (IFN)-inhibitory pathways. The patients pretreated with ribavirin had heightened induction of IFN-related genes and down-regulation of genes involved in IFN inhibition and hepatic stellate cell activation. CONCLUSION: These data suggest that ISG inducibility is important for the treatment response and that ribavirin may improve outcomes by enhancing hepatic gene responses to peginterferon. Collectively, these mechanisms may provide a molecular basis for the improved efficacy of combination therapy.