Inhibition of Amazon deforestation and fire by parks and indigenous lands.

Conservation scientists generally agree that many types of protected areas will be needed to protect tropical forests. But little is known of the comparative performance of inhabited and uninhabited reserves in slowing the most extreme form of forest disturbance: conversion to agriculture. We used satellite-based maps of land cover and fire occurrence in the Brazilian Amazon to compare the performance of large (> 10,000 ha) uninhabited (parks) and inhabited (indigenous lands, extractive reserves, and national forests) reserves. Reserves significantly reduced both deforestation and fire. Deforestation was 1.7 (extractive reserves) to 20 (parks) times higher along the outside versus the inside of the reserve perimeters and fire occurrence was 4 (indigenous lands) to 9 (national forests) times higher. No strong difference in the inhibition of deforestation (p = 0. 11) or fire (p = 0.34) was found between parks and indigenous lands. However, uninhabited reserves tended to be located away from areas of high deforestation and burning rates. In contrast, indigenous lands were often created in response to frontier expansion, and many prevented deforestation completely despite high rates of deforestation along their boundaries. The inhibitory effect of indigenous lands on deforestation was strong after centuries of contact with the national society and was not correlated with indigenous population density. Indigenous lands occupy one-fifth of the Brazilian Amazon-five times the area under protection in parks--and are currently the most important barrier to Amazon deforestation. As the protected-area network expands from 36% to 41% of the Brazilian Amazon over the coming years, the greatest challenge will be successful reserve implementation in high-risk areas of frontier expansion as indigenous lands are strengthened. This success will depend on a broad base of political support.

Oral norfloxacin for prevention of gram-negative bacterial infections in patients with acute leukemia and granulocytopenia. A randomized, double-blind, placebo-controlled trial.

We evaluated the effect of norfloxacin, 400 mg given orally every 12 hours, on the prevention of bacterial infections in 68 adult patients who had acute leukemia throughout prolonged courses of granulocytopenia (median, 32 days). Gram-negative infections were documented in 13 of the 33 patients receiving placebo, but only in 4 of the 35 patients receiving norfloxacin; no effect on the frequency of gram-positive or fungal infections was noted. Norfloxacin administration resulted in the suppression of gastrointestinal tract colonization by aerobic bacteria without the development of norfloxacin resistance. Patients receiving norfloxacin developed first infectious fevers later than did those receiving placebo, had more rapid resolution of that fever after systemic antibiotic treatment, and spent less time febrile. Therefore, although no difference was seen in survival duration, we found that the prophylactic administration of oral norfloxacin led to decreases in overall morbidity and gram-negative infections, was well tolerated, and did not predispose to the development of multiply drug-resistant bacteria.

Infection management during antileukemia treatment-induced granulocytopenia: the role for oral norfloxacin prophylaxis against infections arising from the gastrointestinal tract.

Aerobic gram negative bacterial infections occur commonly in patients with acute leukemia undergoing intensive chemotherapy-induced bone marrow aplasia, and often arise from the gastrointestinal (GI) tract. The value of oral prophylactic norfloxacin (400 mg every 12 hours) in preventing bacterial infections was determined for 68 adults with acute leukemia by a prospective, randomized, double-blind, placebo-controlled trial. The efficacy of norfloxacin administered prophylactically throughout the course of intensive therapy and deep (less than 100 mm/3), prolonged (median 32 day) granulocytopenia against infections arising from the GI tract was demonstrated by its impact on the clinical manifestations of infection, microbiologically documented gram negative bacterial infections, overall antibiotic management, and GI colonization. Although there was no difference with respect to survival, norfloxacin decreased overall morbidity associated with gram-negative infections, was well tolerated, did not impinge on systemic antibacterial or antitumor therapy, and did not predispose to the development of bacteria resistant either to itself or to multiple other antibiotics. The advantages of norfloxacin relative to other oral agents used for GI prophylaxis and the potential beneficial effects of norfloxacin or overall medical cost are discussed. Oral norfloxacin achieves the goals of GI prophylaxis by effectively suppressing early infection arising from the GI tract and inhibiting GI colonization by multiply resistant pathogens that could give rise to late-onset infections during profound chemotherapy-induced bone marrow aplasia.