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1.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 555-559, 2019 Jul 24.
Artigo em Chinês | MEDLINE | ID: mdl-31713395

RESUMO

Exosomes are tiny vesicles secreted by most endogenous cells, and the extracellular vesicles (EVs) are specifically secreted by cells. Recently, it was found that exosomes contain a large quantity of important substances such as proteins, nucleic acids, and lipids, which play important roles in material exchange and information transmission in cell-cell communication, and in modulating the immune response, metabolism, and expansion, metastasis, and drug resistance of tumors. This paper summarizes the recent researches on exosomes in parasites and parasitic diseases and hopes to be helpful for improving the researches of parasites and parasitic diseases.


Assuntos
Exossomos , Vesículas Extracelulares , Parasitos , Doenças Parasitárias , Animais , Vesículas Extracelulares/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/citologia , Doenças Parasitárias/parasitologia , Pesquisa/tendências
2.
Trends Parasitol ; 34(12): 1038-1055, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30201278

RESUMO

Mitochondria originated from the endosymbiotic event commencing from the engulfment of an ancestral α-proteobacterium by the first eukaryotic ancestor. Establishment of niches has led to various adaptations among eukaryotes. In anaerobic parasitic protists, the mitochondria have undergone modifications by combining features shared from the aerobic mitochondria with lineage-specific components and mechanisms; a diversified class of organelles emerged and are generally called mitochondrion-related organelles (MROs). In this review we summarize and discuss the recent advances in the knowledge of MROs from parasitic protists, particularly the themes such as metabolic functions, contribution to parasitism, dynamics, protein targeting, and novel lineage- specific proteins, with emphasis on the diversity among these organelles.


Assuntos
Eucariotos/fisiologia , Mitocôndrias/fisiologia , Parasitos/fisiologia , Animais , Biodiversidade , Evolução Biológica , Eucariotos/classificação , Eucariotos/citologia , Parasitos/classificação , Parasitos/citologia
3.
Expert Rev Proteomics ; 15(5): 371-390, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29717934

RESUMO

INTRODUCTION: Leishmania spp. are causative agents of leishmaniasis, a broad-spectrum neglected vector-borne disease. Genomic and transcriptional studies are not capable of solving intricate biological mysteries, leading to the emergence of proteomics, which can provide insights into the field of parasite biology and its interactions with the host. Areas covered: The combination of genomics and informatics with high throughput proteomics may improve our understanding of parasite biology and pathogenesis. This review analyses the roles of diverse proteomic technologies that facilitate our understanding of global protein profiles and definition of parasite development, survival, virulence and drug resistance mechanisms for disease intervention. Additionally, recent innovations in proteomics have provided insights concerning the drawbacks associated with conventional chemotherapeutic approaches and Leishmania biology, host-parasite interactions and the development of new therapeutic approaches. Expert commentary: With progressive breakthroughs in the foreseeable future, proteome profiles could provide target molecules for vaccine development and therapeutic intervention. Furthermore, proteomics, in combination with genomics and informatics, could facilitate the elimination of several diseases. Taken together, this review provides an outlook on developments in Leishmania proteomics and their clinical implications.


Assuntos
Leishmania/metabolismo , Parasitos/metabolismo , Proteômica/métodos , Animais , Humanos , Leishmania/citologia , Leishmania/crescimento & desenvolvimento , Parasitos/citologia , Parasitos/crescimento & desenvolvimento , Proteoma/metabolismo , Proteínas de Protozoários/metabolismo , Biologia de Sistemas
5.
Front Immunol ; 9: 3066, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30697211

RESUMO

Extracellular vesicles (EVs) are small membrane-surrounded structures released by different kinds of cells (normal, diseased, and transformed cells) in vivo and in vitro that contain large amounts of important substances (such as lipids, proteins, metabolites, DNA, RNA, and non-coding RNA (ncRNA), including miRNA, lncRNA, tRNA, rRNA, snoRNA, and scaRNA) in an evolutionarily conserved manner. EVs, including exosomes, play a role in the transmission of information, and substances between cells that is increasingly being recognized as important. In some infectious diseases such as parasitic diseases, EVs have emerged as a ubiquitous mechanism for mediating communication during host-parasite interactions. EVs can enable multiple modes to transfer virulence factors and effector molecules from parasites to hosts, thereby regulating host gene expression, and immune responses and, consequently, mediating the pathogenic process, which has made us rethink our understanding of the host-parasite interface. Thus, here, we review the present findings regarding EVs (especially exosomes) and recognize the role of EVs in host-parasite interactions. We hope that a better understanding of the mechanisms of parasite-derived EVs may provide new insights for further diagnostic biomarker, vaccine, and therapeutic development.


Assuntos
Exossomos/imunologia , Interações Hospedeiro-Parasita/imunologia , Parasitos/imunologia , Doenças Parasitárias/imunologia , Animais , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Biomarcadores/análise , Exossomos/efeitos dos fármacos , Exossomos/metabolismo , Interações Hospedeiro-Parasita/efeitos dos fármacos , Humanos , Parasitos/citologia , Doenças Parasitárias/diagnóstico , Doenças Parasitárias/parasitologia , Doenças Parasitárias/terapia , Vacinas Protozoárias/imunologia , Vacinas Protozoárias/uso terapêutico , Fatores de Virulência/imunologia , Fatores de Virulência/metabolismo
6.
BMC Res Notes ; 10(1): 494, 2017 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-28985767

RESUMO

BACKGROUND: Histological acute appendicitis patterns associated with Enterobius vermicularis is an extremely rare finding. The exact role of this parasite in acute appendicitis is controversial as usually resected specimens show no evidence of histological inflammation. CASE PRESENTATION: We present herein a case of a 21-year-old male Arabic patient who presented with clinical syndrome of acute appendicitis. Emergency appendectomy was performed and the histopathological examination of the resected specimen showed the presence of E. vermicularis as well as intense acute inflammatory patterns such as mucosal ulceration and suppurative necrosis. The post-operative course was uneventful and the patient was discharged with appropriate anti-helmintic drug prescription. CONCLUSION: Acute appendicitis due to E. vermicularis is a very rare occurrence. The histopathological analysis of resected specimens should pay special attention to search for this parasite for adequate post-operative treatment of patients.


Assuntos
Apendicite/parasitologia , Enterobius/fisiologia , Achados Incidentais , Animais , Apendicite/complicações , Apendicite/patologia , Apendicite/cirurgia , Apêndice/patologia , Apêndice/cirurgia , Enterobius/citologia , Feminino , Humanos , Inflamação/complicações , Inflamação/patologia , Masculino , Parasitos/citologia , Parasitos/fisiologia , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-28676844

RESUMO

Coenzyme A (CoA) is an essential universal cofactor for all prokaryotic and eukaryotic cells. In nearly all non-photosynthetic cells, CoA biosynthesis depends on the uptake and phosphorylation of vitamin B5 (pantothenic acid or pantothenate). Recently, putative pantothenate transporter (PAT) and pantothenate kinases (PanKs) were functionally characterized in P. yoelii. PAT and PanKs were shown to be dispensable for blood stage development, but they were essential for mosquito stages development. Yet, little is known about the cellular functions of the other enzymes of the CoA biosynthesis pathway in malaria parasite life cycle stages. All enzymes of this pathway were targeted for deletion or deletion/complementation analyses by knockout/knock-in plasmid constructs to reveal their essential roles in P. yoelii life cycle stages. The intermediate enzymes PPCS (Phosphopantothenylcysteine Synthase), PPCDC (Phosphopantothenylcysteine Decarboxylase) were shown to be dispensable for asexual and sexual blood stage development, but they were essential for oocyst development and the production of sporozoites. However, the last two enzymes of this pathway, PPAT (Phosphopantetheine Adenylyltransferase) and DPCK (Dephospho-CoA Kinase), were essential for blood stage development. These results indicate alternative first substrate requirement for the malaria parasite, other than the canonical pantothenate, for the synthesis of CoA in the blood but not inside the mosquito midgut. Collectively, our data shows that CoA de novo biosynthesis is essential for both blood and mosquito stages, and thus validates the enzymes of this pathway as potential antimalarial targets.


Assuntos
Coenzima A/biossíntese , Coenzima A/genética , Culicidae/parasitologia , Malária/sangue , Malária/parasitologia , Parasitos/genética , Parasitos/metabolismo , Animais , Feminino , Deleção de Genes , Técnicas de Inativação de Genes , Estágios do Ciclo de Vida/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Oocistos/metabolismo , Parasitos/citologia , Parasitos/enzimologia , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo
8.
Indian J Pathol Microbiol ; 60(2): 202-205, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28631635

RESUMO

OBJECTIVE: Direct microscopic visualization is the most specific method for detecting intestinal parasites and is commonly achieved by stool examination or mucosal biopsy. However, postfixation, the intestinal biopsy fragment is often curled, and the entire surface of the biopsied mucosa is seldom viewed microscopically. Tissue processing further distorts morphology of the organisms and causes diagnostic difficulties. Examining multiple sections for parasite detection is time-consuming and often requires aid of special stains and/or immunohistochemistry. To overcome these disadvantages, we hypothesized that the fixative in which biopsies are transferred may provide a valid representation of the biopsied mucosal surface and therefore aid in the identification of mucosal surface parasites. MATERIALS AND METHODS: Formalin in which biopsies were transferred was retained, stored at 4°C and processed with a cytocentrifuge. Totally, 120 consequent duodenal biopsy fixatives were processed in this way and the cytocentrifuged smears visualized after May-Grunwald-Giemsa staining. Findings of these smears were correlated with their corresponding formalin fixed paraffin embedded tissue sections. RESULTS: Cytocentrifuged formalin preparations were found to be representative of the mucosal surface contents. Giardia trophozoites were visualized in 10/120 preparations with distinct morphological characteristics which were seldom appreciable in tissue sections, eliminating the need for special stains. Furthermore, two of the corresponding histology sections did not demonstrate the parasites despite step sections, while in one case few parasites could be identified in the step sections. CONCLUSIONS: Cytocentrifuged fixative preparation is a simple and cost-effective technique which can be routinely employed for intestinal parasite characterization.


Assuntos
Centrifugação/métodos , Enteropatias Parasitárias/diagnóstico , Microscopia/métodos , Parasitos/isolamento & purificação , Patologia/métodos , Manejo de Espécimes/métodos , Fixação de Tecidos/métodos , Animais , Biópsia , Análise Custo-Benefício , Fixadores/farmacologia , Humanos , Mucosa Intestinal/patologia , Parasitos/citologia , Temperatura Ambiente
9.
Microsc Res Tech ; 80(8): 969-972, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28497876

RESUMO

The modified acid fast staining technique is a commonly used procedure for the detection of coccidian parasites in developing countries. The morphological variations observed in these parasites play a significant role to some extent in both identification and diagnosis of these parasitic infections. A prospective cross sectional study was performed over three years. The fecal smears were stained by modified Kinyoun acid-fast staining technique and were extensively studied for morphological variations in the coccidian parasites. Out of a total of two thousand one hundred fifty one (n = 2,151) fecal samples received during the study period, 259 samples (12%) were positive for any one of the coccidian parasites. Morphological variations, especially in the staining character was noted in all the three coccidian parasites. This study was an attempt to characterize different variations in size, shape and staining characteristics of the three coccidian parasites.


Assuntos
Fezes/parasitologia , Oocistos/citologia , Parasitos/citologia , Animais , Coccídios , Humanos , Índia , Microscopia , Oocistos/classificação , Oocistos/isolamento & purificação , Parasitos/classificação , Parasitos/crescimento & desenvolvimento , Parasitos/isolamento & purificação , Estudos Prospectivos , Centros de Atenção Terciária
11.
Autophagy ; 13(4): 715-729, 2017 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-28121493

RESUMO

Autophagy is a catabolic cellular process required to maintain protein synthesis, energy production and other essential activities in starved cells. While the exact nutrient sensor(s) is yet to be identified, deprivation of amino acids, glucose, growth factor and other nutrients can serve as metabolic stimuli to initiate autophagy in higher eukaryotes. In the early-branching unicellular parasite Trypanosoma brucei, which can proliferate as procyclic form (PCF) in the tsetse fly or as bloodstream form (BSF) in animal hosts, autophagy is robustly triggered by amino acid deficiency but not by glucose depletion. Taking advantage of the clearly defined adenosine triphosphate (ATP) production pathways in T. brucei, we have shown that autophagic activity depends on the levels of cellular ATP production, using either glucose or proline as a carbon source. While autophagosome formation positively correlates with cellular ATP levels; perturbation of ATP production by removing carbon sources or genetic silencing of enzymes involved in ATP generation pathways, also inhibited autophagy. This obligate energy dependence and the lack of glucose starvation-induced autophagy in T. brucei may reflect an adaptation to its specialized, parasitic life style.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/farmacologia , Autofagia/efeitos dos fármacos , Parasitos/citologia , Parasitos/enzimologia , Trypanosoma brucei brucei/citologia , Trypanosoma brucei brucei/enzimologia , Aminoácidos/deficiência , Animais , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Estágios do Ciclo de Vida , Parasitos/efeitos dos fármacos , Prolina/metabolismo , Trypanosoma brucei brucei/efeitos dos fármacos , Trypanosoma brucei brucei/crescimento & desenvolvimento
12.
Microbiol Spectr ; 4(4)2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27726811

RESUMO

This chapter aims to provide some key points for researchers interested in the study of ancient gastrointestinal parasites. These few pages are dedicated to my colleague and friend, Prof. Adauto Araújo (1951-2015), who participated in the writing of this chapter. His huge efforts in paleoparasitology contributed to the development and promotion of the discipline during more than 30 years.


Assuntos
Fósseis/parasitologia , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/história , Paleopatologia/métodos , Parasitos/isolamento & purificação , Animais , Arqueologia/métodos , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , História Antiga , História Medieval , Humanos , Parasitos/classificação , Parasitos/citologia , Parasitos/genética , Parasitologia/história , Parasitologia/métodos
13.
J Cell Biol ; 214(5): 507-15, 2016 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-27573462

RESUMO

The capacity to migrate is fundamental to multicellular and single-celled life. Apicomplexan parasites, an ancient protozoan clade that includes malaria parasites (Plasmodium) and Toxoplasma, achieve remarkable speeds of directional cell movement. This rapidity is achieved via a divergent actomyosin motor system, housed within a narrow compartment that lies underneath the length of the parasite plasma membrane. How this motor functions at a mechanistic level during motility and host cell invasion is a matter of debate. Here, we integrate old and new insights toward refining the current model for the function of this motor with the aim of revitalizing interest in the mechanics of how these deadly pathogens move.


Assuntos
Movimento Celular , Interações Hospedeiro-Parasita , Parasitos/citologia , Animais , Adesão Celular , Forma Celular , Humanos , Modelos Biológicos
14.
J Cell Sci ; 129(17): 3320-31, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27457282

RESUMO

The apicomplexan protozoan Toxoplasma gondii, the causative agent of toxoplasmosis, harbors an apicoplast, a plastid-like organelle with essential metabolic functions. Although the FASII fatty acid biosynthesis pathway located in the apicoplast is essential for parasite survival, the cellular effects of FASII disruption in T. gondii had not been examined in detail. Here, we combined light and electron microscopy techniques - including focused ion beam scanning electron microscopy (FIB-SEM) - to characterize the effect of FASII disruption in T. gondii, by treatment with the FASII inhibitor triclosan or by inducible knockdown of the FASII component acyl carrier protein. Morphological analyses showed that FASII disruption prevented cytokinesis completion in T. gondii tachyzoites, leading to the formation of large masses of 'tethered' daughter cells. FIB-SEM showed that tethered daughters had a mature basal complex, but a defect in new membrane addition between daughters resulted in incomplete pellicle formation. Addition of exogenous fatty acids to medium suppressed the formation of tethered daughter cells and supports the notion that FASII is essential to generate lipid substrates required for the final step of parasite division.


Assuntos
Apicoplastos/metabolismo , Citocinese , Ácidos Graxos/biossíntese , Toxoplasma/citologia , Toxoplasma/metabolismo , Animais , Apicoplastos/ultraestrutura , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Ácido Graxo Sintases/metabolismo , Técnicas de Silenciamento de Genes , Estágios do Ciclo de Vida/efeitos dos fármacos , Macaca mulatta , Parasitos/citologia , Parasitos/efeitos dos fármacos , Parasitos/crescimento & desenvolvimento , Parasitos/ultraestrutura , Toxoplasma/crescimento & desenvolvimento , Toxoplasma/ultraestrutura , Triclosan/farmacologia
15.
Korean J Parasitol ; 54(3): 339-44, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27417091

RESUMO

The genus Sarcocystis is not usually considered as an important enteric pathogen in immune compromised patients. It might be expected that species for which humans are the final host (Sarcocystis hominis and Sarcocystis suihominis as well as possibly others) would be encountered increasingly often in immunodeficient persons. This study aimed to address how to detect and differentiate Sarcocystis oocysts and/or sporocysts from enteric protozoans in the diarrheal samples of immunodeficient patients in Shiraz, Iran. Diarrheal samples of 741 immunodeficient patients with recurrent persistent or chronic diarrhea were examined by microscopy and molecular biological analysis. Oocysts-positive samples were 68 Cryptosporidium spp., 9 Cystoisospora belli (syn. Isospora belli), 2 Cyclospora cayetanensis, and 15 microsporidia (Enterocytozoon bieneusi). Sarcocystis-like sporocysts found from a woman were identified as Sarcocystis cruzi through 18S rDNA amplification and phylogenetic analysis. To the best of our knowledge, this is the first report of S. cruzi from a human.


Assuntos
Diarreia/epidemiologia , Fezes/parasitologia , Hospedeiro Imunocomprometido , Oocistos , Parasitos/classificação , Parasitos/isolamento & purificação , Infecções por Protozoários/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Análise por Conglomerados , DNA de Protozoário/química , DNA de Protozoário/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Diarreia/parasitologia , Feminino , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Microscopia , Pessoa de Meia-Idade , Parasitos/citologia , Parasitos/genética , Filogenia , Prevalência , Infecções por Protozoários/parasitologia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Adulto Jovem
16.
Parasitology ; 143(8): 931-56, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27253438

RESUMO

Blood parasites are considered some of the most significant pathogens for the conservation of penguins, due to the considerable morbidity and mortality they have been shown to produce in captive and wild populations of these birds. Parasites known to occur in the blood of penguins include haemosporidian protozoans (Plasmodium, Leucocytozoon, Haemoproteus), piroplamid protozoans (Babesia), kinetoplastid protozoans (Trypanosoma), spirochete bacteria (Borrelia) and nematode microfilariae. This review provides a critical and comprehensive assessment of the current knowledge on these parasites, providing an overview of their biology, host and geographic distribution, epidemiology, pathology and implications for public health and conservation.


Assuntos
Doenças das Aves/parasitologia , Infecções por Nematoides/veterinária , Parasitos/fisiologia , Spheniscidae/parasitologia , Tripanossomíase/veterinária , Animais , Doenças das Aves/epidemiologia , Geografia , Haemosporida/citologia , Haemosporida/fisiologia , Nematoides/citologia , Nematoides/fisiologia , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Parasitos/citologia , Plasmodium/citologia , Plasmodium/fisiologia , Infecções Protozoárias em Animais/epidemiologia , Infecções Protozoárias em Animais/parasitologia , Trypanosoma/citologia , Trypanosoma/fisiologia , Tripanossomíase/epidemiologia , Tripanossomíase/parasitologia
17.
Curr Protoc Cytom ; 76: 11.21.1-11.21.15, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27037578

RESUMO

Traditional jet-in-air cell sorters have been designed and optimized to isolate small particles such as mammalian lymphocytes with an average diameter of 10 µm. We discuss the practical considerations of setting up a conventional jet-in-air cell sorter, using a 200-µm nozzle, to isolate the large parasitic nematode eggs of Nippostrongylus brasiliensis, with a maximum size of 60 µm. The eggs were separated based on light scattering properties, no fluorescent dye or molecule was required.


Assuntos
Citometria de Fluxo/métodos , Nippostrongylus/citologia , Óvulo/citologia , Animais , Fezes/parasitologia , Camundongos , Parasitos/citologia , Controle de Qualidade , Ratos , Esterilização
18.
Faraday Discuss ; 187: 341-52, 2016 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-27071693

RESUMO

New highly sensitive tools for malaria diagnostics are urgently needed to enable the detection of infection in asymptomatic carriers and patients with low parasitemia. In pursuit of a highly sensitive diagnostic tool that can identify parasite infections at the single cell level, we have been exploring Fourier transform infrared (FTIR) microscopy using a Focal Plane Array (FPA) imaging detector. Here we report for the first time the application of a new optic configuration developed by Agilent that incorporates 25× condenser and objective Cassegrain optics with a high numerical aperture (NA = 0.81) along with additional high magnification optics within the microscope to provide 0.66 micron pixel resolution (total IR system magnification of 61×) to diagnose malaria parasites at the single cell level on a conventional glass microscope slide. The high quality images clearly resolve the parasite's digestive vacuole demonstrating sub-cellular resolution using this approach. Moreover, we have developed an algorithm that first detects the cells in the infrared image, and secondly extracts the average spectrum. The average spectrum is then run through a model based on Partial Least Squares-Discriminant Analysis (PLS-DA), which diagnoses unequivocally the infected from normal cells. The high quality images, and the fact this measurement can be achieved without a synchrotron source on a conventional glass slide, shows promise as a potential gold standard for malaria detection at the single cell level.


Assuntos
Eritrócitos/parasitologia , Vidro/química , Malária/parasitologia , Microscopia/instrumentação , Parasitos/isolamento & purificação , Análise de Célula Única/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/instrumentação , Animais , Humanos , Malária/diagnóstico , Microscopia/métodos , Parasitos/citologia , Plasmodium/citologia , Plasmodium/isolamento & purificação , Análise de Célula Única/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier/métodos
19.
Conf Proc IEEE Eng Med Biol Soc ; 2016: 3981-3984, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-28269157

RESUMO

This paper presents a method to detect unlabeled malaria parasites in red blood cells. The current "gold standard" for malaria diagnosis is microscopic examination of thick blood smear, a time consuming process requiring extensive training. Our goal is to develop an automate process to identify malaria infected red blood cells. Major issues in automated analysis of microscopy images of unstained blood smears include overlapping cells and oddly shaped cells. Our approach creates robust templates to detect infected and uninfected red cells. Histogram of Oriented Gradients (HOGs) features are extracted from templates and used to train a classifier offline. Next, the ViolaJones object detection framework is applied to detect infected and uninfected red cells and the image background. Results show our approach out-performs classification approaches with PCA features by 50% and cell detection algorithms applying Hough transforms by 24%. Majority of related work are designed to automatically detect stained parasites in blood smears where the cells are fixed. Although it is more challenging to design algorithms for unstained parasites, our methods will allow analysis of parasite progression in live cells under different drug treatments.


Assuntos
Eritrócitos/parasitologia , Processamento de Imagem Assistida por Computador/métodos , Parasitos/citologia , Coloração e Rotulagem , Algoritmos , Animais , Bases de Dados como Assunto , Humanos , Malária/parasitologia , Análise de Componente Principal
20.
Parasitol Res ; 114(10): 3567-75, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26272631

RESUMO

Parasite-host cell interaction can be modulated by a dynamic communication between extracellular vesicles (EVs). They should play key roles in cell-cell communications transferring biomolecules (miRNA, proteins, soluble factors) from one cell to another cell. While many names have been used to denominate EVs, a better comprehension to understand these vesicles is raised when we classify it according to biogenesis: originated from multivesicular bodies, named exosomes, and from plasmatic membranes, denominated microvesicles. Here, we have reviewed EV participation during the protozoan-host cell interaction and reinforced the differences and similarities between exosomes and microvesicles, suggesting different intracellular routes and functions. We also discussed perspectives to study EVs and the role of EVs in diagnosis and chemotherapies of infectious diseases.


Assuntos
Exossomos , Vesículas Extracelulares , Parasitos/citologia , Animais , Interações Hospedeiro-Parasita , Humanos , Parasitos/fisiologia
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