China
Africa
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Inflammatory, Hypersensitivity and Immune Lung Diseases, including Parasitic Diseases.
Published in Fred W Wright, Radiology of the Chest and Related Conditions, 2022
Amoebic infection remains endemic in tropical and sub-tropical countries, and is still a common cause of morbidity in these areas. Thoracic involvement may be manifest by a sympathetic effusion or be due to direct extension of an amoebic liver abscess through the diaphragm. When this happens, there may be haziness and loss of definition of the diaphragmatic outline, progressing to basal collapse, consolidation and pleural reaction or effusion, followed by lung necrosis and/or an empyema. Amoebic liver abscesses (Illus. AMOEBIC ABSCESS) occur more commonly on the right, but may also be seen on the left (Illus. AMOEBIC ABSCESS, Liver Pt. 7a-d).
Heterocyclic Drug Design and Development
Published in Rohit Dutt, Anil K. Sharma, Raj K. Keservani, Vandana Garg, Promising Drug Molecules of Natural Origin, 2020
Garima Verma, Mohammad Shaquiquzzaman, Mohammad Mumtaz Alam
Any agent that leads to destruction of amoeba is called amoebicide. Such agents are employed in the treatment of amoebazoa infections. Metronidazole, tinidazole, secnidazole, and ornidazole are commonly employed agents. A few such agents are obtained from plant sources as well. They have been documented in Table 9.15.
Repair of Radiation Damage
Published in Kedar N. Prasad, Handbook of RADIOBIOLOGY, 2020
Large, multinucleated amoebae, Pelmyxa illinoisensis, irradiated with 3000 R of X-rays (supralethal dose), died after 4–5 days. Amoebae treated with a supralethal concentration (0.1–0.2 mg/ml for 1 hr) of nitrogen mustard (HN2) died within 12 days after treatment without cell division. When protoplasm (cytoplasm plus nucleus) from an HN2-treated amoeba was injected by fusion into an X-irradiated (30,000 R) amoeba, the composite organisms reproduced and permanently recovered. HN2 probably alkylates the donor amoeba DNA without affecting the cytoplasmic factors. Therefore, cytoplasm from HN2-treated donors also induced recovery.48 The irradiated amoebae also showed complete recovery when they received protoplasm from nonirradiated amoebae within 24 hr after exposure. The cytoplasm from nonirradiated amoebae also prevented radiation death.
Inhibition studies of the protozoan α-carbonic anhydrase from Trypanosoma cruzi with phenols
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Alessandro Bonardi, Seppo Parkkila, Claudiu T. Supuran
Protozoans are microscopic, nonfilamentous protists belonging to a multitude of phyla, with many genera and species described so far, many of which possess ecological and industrial relevance. However, they sometimes produce disease in vertebrates, which may range from mild to moderate, such as those induced by Toxoplasma gondii or Entamoeba histolytica, or may lead to more serious conditions, in the case of infections due to Cryptosporidium parvum, Giardia lamblia, Trichomonas vaginalis, Babesia spp., but also very serious and widespread ones, such as malaria, leishmaniasis, Chagas disease, and African sleeping disease1,2. Although rare, there are also several fatal protozoal diseases, mostly provoked by amoebae belonging to Naegleria fowleri, Acanthamoeba spp. and Balamuthia mandrillaris genera/species1. Few effective therapeutic approaches are available so far for treating most diseases provoked by protozoans1. Albeit all 12 protozoans genera which produce human disease are well studied by now, there are few drugs useful for treating them. Furthermore, these drugs have been available for many decades, generally show high toxicity and low therapeutic indexes, and more concerning, extensive resistance to these treatment options has developed in the last period1,2.
Epidemiology of free-living amoebae in the Philippines: a review and update
Published in Pathogens and Global Health, 2022
Giovanni D. Milanez, Frederick R. Masangkay, Gregorio L. Martin I, Ma. Frieda Z Hapan, Edilberto P. Manahan, Jeffrey Castillo, Panagiotis Karanis
Studies on free-living amoebae (FLA) have in recent decades gained traction in the field of protozoology and parasitology. Known for their ubiquity, FLAs have been isolated from various environmental matrices, such as soil, fresh and brackish water, wastewater, hot springs, dust, and others [1–6]. Aside from environmental sources, FLAs were also reported from cooling towers, air conditioning systems, bromeliad plants, dental water supplies, and are known to contaminate contact lens and lens fluids [7]. In addition, FLA can harbor pathogenic microorganisms within its cytoplasm, enabling them to persist and eventually be transmitted to a broad spectrum of biological hosts via multiple transmission routes. Due to this, FLA is dubbed as ‘Trojan horses’ of the microbial community [8,9]. Prokaryotes persisting within FLA have been called amoebae-resistant bacteria (ARB) by some researchers [10], while most recently, the collective term ‘endocytobionts’ has been used to describe the variety of microorganisms that multiply within an FLA host [11]. This term may be more appropriate considering that FLA, in general, can also internalize viruses [12], fungi [13], and protozoa [4,14,15].
Granulomatous amoebic encephalitis caused by Acanthamoeba in a patient with AIDS: a challenging diagnosis
Published in Acta Clinica Belgica, 2021
Hsien Lee Lau, Daniela F. De Lima Corvino, Francisco M. Guerra, Amer M. Malik, Paola N. Lichtenberger, Sakir H. Gultekin, Jana M. Ritter, Shantanu Roy, Ibne Karim M. Ali, Jennifer R. Cope, M. Judith D. Post, Jose A. Gonzales Zamora
Here we describe an interdisciplinary approach to the diagnosis of amoebic infection in a patient with compatible radiologic and histopathologic features, with confirmation of Acanthamoeba spp. by immunohistochemistry and molecular testing performed on formalin-fixed paraffin-embedded tissue. In our case, amoebas were seen in tissues only after deeper sectioning of the specimen, and then only few organisms were identified by H&E stain. If diagnosis remains unclear after extensive work-up as in our case, thinner sections at multiple levels should be pursued at a more advanced institution because lesions may be few and focal in amoebic infections. Further utilization of new technologies such as next generation sequencing may also identify more cases of GAE to facilitate earlier diagnosis and provide a wider therapeutic window for treatment.