19 resultados para human source
Resumo:
We have described the existence of asymptomatic carriers of Plasmodium vivax and Plasmodium falciparum infections in native Amazon populations. Most of them had low parasitemias, detected only by polymerase chain reaction (PCR). Because they remain symptomless and untreated, we wanted to determine whether they could infect Anopheles darlingi Root, the main Brazilian vector, and act as disease reservoirs. Fifteen adult asymptomatic patients (PCR positive only) were selected, and experimental infections of mosquitoes were performed by direct feeding and by a membrane-feeding system. Seventeen adult symptomatic patients with high parasitemias were used as controls. We found an infection rate in An. darlingi of 1.2% for the asymptomatic carriers and 22% for the symptomatic carriers. Although the asymptomatic group infected mosquitoes at a much lower rate, these patients remain infective longer than treated, symptomatic patients. Also, the prevalence of asymptomatic infections is 4 to 5 times higher than symptomatic infections among natives. These results have implications for the malaria control program in Brazil, which focuses essentially on the treatment of symptomatic patients. © 2005 Entomological Society of America.
Resumo:
Vampire bats are notorious for being the sole mammals that strictly feed on fresh blood for their survival. While their saliva has been historically associated with anticoagulants, only one antihemostatic (plasminogen activator) has been molecularly and functionally characterized. Here, RNAs from both principal and accessory submaxillary (submandibular) salivary glands of Desmodus rotundus were extracted, and ~. 200. million reads were sequenced by Illumina. The principal gland was enriched with plasminogen activators with fibrinolytic properties, members of lipocalin and secretoglobin families, which bind prohemostatic prostaglandins, and endonucleases, which cleave neutrophil-derived procoagulant NETs. Anticoagulant (tissue factor pathway inhibitor, TFPI), vasodilators (PACAP and C-natriuretic peptide), and metalloproteases (ADAMTS-1) were also abundantly expressed. Members of the TSG-6 (anti-inflammatory), antigen 5/CRISP, and CCL28-like (antimicrobial) protein families were also sequenced. Apyrases (which remove platelet agonist ADP), phosphatases (which degrade procoagulant polyphosphates), and sphingomyelinase were found at lower transcriptional levels. Accessory glands were enriched with antimicrobials (lysozyme, defensin, lactotransferrin) and protease inhibitors (TIL-domain, cystatin, Kazal). Mucins, heme-oxygenase, and IgG chains were present in both glands. Proteome analysis by nano LC-MS/MS confirmed that several transcripts are expressed in the glands. The database presented herein is accessible online at http://exon.niaid.nih.gov/transcriptome/D_rotundus/Supplemental-web.xlsx. These results reveal that bat saliva emerges as a novel source of modulators of vascular biology. Biological significance: Vampire bat saliva emerges as a novel source of antihemostatics which modulate several aspects of vascular biology. © 2013.
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)