scholarly journals Raman spectroscopic analysis of skin as a diagnostic tool for Human African Trypanosomiasis

2021 ◽  
Vol 17 (11) ◽  
pp. e1010060
Author(s):  
Alexandre Girard ◽  
Anneli Cooper ◽  
Samuel Mabbott ◽  
Barbara Bradley ◽  
Steven Asiala ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Trypanosoma Brucei ◽  
Diagnostic Tool ◽  
Human African Trypanosomiasis ◽  
Ex Vivo ◽  
Principal Component ◽  
Medical Diagnostics ◽  
Diagnostic Tools ◽  
African Trypanosomiasis ◽  
Non Invasive

Human African Trypanosomiasis (HAT) has been responsible for several deadly epidemics throughout the 20th century, but a renewed commitment to disease control has significantly reduced new cases and motivated a target for the elimination of Trypanosoma brucei gambiense-HAT by 2030. However, the recent identification of latent human infections, and the detection of trypanosomes in extravascular tissues hidden from current diagnostic tools, such as the skin, has added new complexity to identifying infected individuals. New and improved diagnostic tests to detect Trypanosoma brucei infection by interrogating the skin are therefore needed. Recent advances have improved the cost, sensitivity and portability of Raman spectroscopy technology for non-invasive medical diagnostics, making it an attractive tool for gambiense-HAT detection. The aim of this work was to assess and develop a new non-invasive diagnostic method for T. brucei through Raman spectroscopy of the skin. Infections were performed in an established murine disease model using the animal-infective Trypanosoma brucei brucei subspecies. The skin of infected and matched control mice was scrutinized ex vivo using a confocal Raman microscope with 532 nm excitation and in situ at 785 nm excitation with a portable field-compatible instrument. Spectral evaluation and Principal Component Analysis confirmed discrimination of T. brucei-infected from uninfected tissue, and a characterisation of biochemical changes in lipids and proteins in parasite-infected skin indicated by prominent Raman peak intensities was performed. This study is the first to demonstrate the application of Raman spectroscopy for the detection of T. brucei by targeting the skin of the host. The technique has significant potential to discriminate between infected and non-infected tissue and could represent a unique, non-invasive diagnostic tool in the goal for elimination of gambiense-HAT as well as for Animal African Trypanosomiasis (AAT).

New Pd-Fe ferrocenyl antiparasitic compounds with bioactive 8-hydroxyquinoline ligands: a comparative study with their Pt-Fe analogues

2021 ◽  
Author(s):  
Feriannys Rivas ◽  
Andrea Medeiros ◽  
Cristina Quiroga ◽  
Diego Benítez ◽  
Marcelo Comini ◽  
...  
Keyword(s):  
Comparative Study ◽  
Trypanosoma Brucei ◽  
Human African Trypanosomiasis ◽  
African Trypanosomiasis

In the search for a more effective chemotherapy for the treatment of Human African Trypanosomiasis, the disease caused by the parasite Trypanosoma brucei, the development of ferrocenyl compounds has arisen...

scholarly journals A pilot study to establish non-invasive biomarkers for higher-grade meningioma

2019 ◽  
Vol 21 (Supplement_4) ◽  
pp. iv6-iv6
Author(s):  
Daniele Baiz ◽  
Caterina Negroni ◽  
Emanuela Ercolano ◽  
Claire L Adams ◽  
Kathreena M Kurian ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Tumour Progression ◽  
Primary Tumour ◽  
Regulation Of Gene Expression ◽  
Diagnostic Tools ◽  
Malignant Tumours ◽  
Liquid Biopsies ◽  
Benign Meningioma ◽  
Non Invasive ◽  
Serum Exosomes

Abstract Introduction Meningioma brain tumours are the most common primary tumour in adults. Despite surgery and/or radiation therapy, meningioma may recur. The 5-year recurrence rate in benign meningioma is estimated in about 10% while much greater in atypical and malignant tumours. MicroRNAs (miRNAs) represent a large class of small RNAs driving regulation of gene expression and playing a role in tumour progression and therefore proposed as diagnostic tools. Moreover, miRNAs can be released from tumour cells into the blood stream via exosomes, showing potential to be used as liquid biopsies. Methods Identification of novel circulating biomarkers was conducted by performing an unbiased Cancer MicroRNA qPCR Array, followed by bioinformatics analysis. In parallel, we conducted a biased in silico analysis of the miRNAs targeting Cyclin D1 and E1, recently proposed as immunohistochemical meningioma biomarkers. Validation studies performed using TaqMan® reagents. Results Stringent unbiased (p<0.01) miRNA profiling followed by validation in ex vivo samples revealed that the miR-9-1 is upregulated in higher-grade meningioma tissues and serum exosomes, controlled by the EGFR/AP-1 axis and correlated with lower levels of E-Cadherin, a proposed biomarker for malignant meningioma. On the contrary, biased analysis, followed by validation in vitro and ex vivo, showed that the miR-497~195 cluster is downregulated in higher-grade meningioma tissues and serum exosomes, correlating with the overexpression of GATA-4, a novel meningioma tissue biomarker. Conclusion Our data demonstrated that both miR-497~195 and miR-9-1 show potential to become promising non-invasive biomarkers for higher-grade meningioma, reflecting their expression status in tissues. (DB and CN contributed equally).

scholarly journals Cross-Resistance to Nitro Drugs and Implications for Treatment of Human African Trypanosomiasis

2010 ◽  
Vol 54 (7) ◽  
pp. 2893-2900 ◽  
Author(s):  
Antoaneta Y. Sokolova ◽  
Susan Wyllie ◽  
Stephen Patterson ◽  
Sandra L. Oza ◽  
Kevin D. Read ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Human African Trypanosomiasis ◽  
Parent Drug ◽  
Cross Resistance ◽  
Pharmacokinetic Studies ◽  
African Trypanosomiasis ◽  
Trypanosoma Brucei Brucei ◽  
Resistant Lines

ABSTRACT The success of nifurtimox-eflornithine combination therapy (NECT) for the treatment of human African trypanosomiasis (HAT) has renewed interest in the potential of nitro drugs as chemotherapeutics. In order to study the implications of the more widespread use of nitro drugs against these parasites, we examined the in vivo and in vitro resistance potentials of nifurtimox and fexinidazole and its metabolites. Following selection in vitro by exposure to increasing concentrations of nifurtimox, Trypanosoma brucei brucei nifurtimox-resistant clones designated NfxR1 and NfxR2 were generated. Both cell lines were found to be 8-fold less sensitive to nifurtimox than parental cells and demonstrated cross-resistance to a number of other nitro drugs, most notably the clinical trial candidate fexinidazole (∼27-fold more resistant than parental cells). Studies of mice confirmed that the generation of nifurtimox resistance in these parasites did not compromise virulence, and NfxR1 remained resistant to both nifurtimox and fexinidazole in vivo. In the case of fexinidazole, drug metabolism and pharmacokinetic studies indicate that the parent drug is rapidly metabolized to the sulfoxide and sulfone form of this compound. These metabolites retained trypanocidal activity but were less effective in nifurtimox-resistant lines. Significantly, trypanosomes selected for resistance to fexinidazole were 10-fold more resistant to nifurtimox than parental cells. This reciprocal cross-resistance has important implications for the therapeutic use of nifurtimox in a clinical setting and highlights a potential danger in the use of fexinidazole as a monotherapy.

Human African trypanosomiasis

2010 ◽  
pp. 1119-1127
Author(s):  
August Stich
Keyword(s):  
West Africa ◽  
East Africa ◽  
Trypanosoma Brucei ◽  
Human African Trypanosomiasis ◽  
Protozoan Parasite ◽  
Sleeping Sickness ◽  
Tsetse Flies ◽  
African Trypanosomiasis ◽  
Tropical Africa

Human African trypanosomiasis (HAT, sleeping sickness) is caused by two subspecies of the protozoan parasite Trypanosoma brucei: T. b. rhodesiense is prevalent in East Africa among many wild and domestic mammals; T. b. gambiense causes an anthroponosis in Central and West Africa. The disease is restricted to tropical Africa where it is transmitted by the bite of infected tsetse flies (...

Human African trypanosomiasis

2020 ◽  
pp. 1451-1459
Author(s):  
Reto Brun ◽  
Johannes Blum
Keyword(s):  
Trypanosoma Brucei ◽  
Human African Trypanosomiasis ◽  
Specific Treatment ◽  
Protozoan Parasite ◽  
Control Measures ◽  
Tsetse Flies ◽  
African Trypanosomiasis ◽  
Control Programmes ◽  
The 1960S ◽  
Stage 1

Human African trypanosomiasis (sleeping sickness) is caused by subspecies of the protozoan parasite Trypanosoma brucei. The disease is restricted to tropical Africa where it is transmitted by the bite of infected tsetse flies (Glossina spp.). Control programmes in the 1960s were very effective, but subsequent relaxation of control measures led to recurrence of epidemic proportions in the 1980s and 1990s. Control is now being regained. Untreated human African trypanosomiasis is almost invariably fatal. Specific treatment depends on the trypanosome subspecies and the stage of the disease. Drugs used for stage 1 include pentamidine and suramin, and for stage 2 include melarsoprol, eflornithine, and nifurtimox, but regimens are not standardized, and treatment is difficult and dangerous; all of the drugs used have many side effects, some potentially lethal.

scholarly journals Benzimidazole inhibitors of the major cysteine protease of Trypanosoma brucei

2019 ◽  
Vol 11 (13) ◽  
pp. 1537-1551 ◽  
Author(s):  
Glaécia AN Pereira ◽  
Lucianna H Santos ◽  
Steven C Wang ◽  
Luan C Martins ◽  
Filipe S Villela ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Human African Trypanosomiasis ◽  
Cysteine Proteases ◽  
African Trypanosomiasis ◽  
High Similarity ◽  
Trypanosoma Brucei Brucei ◽  
Structure Activity ◽  
Starting Point ◽  
Competitive Inhibitors ◽  
Enzyme Selectivity

Aim: Limitations in available therapies for trypanosomiases indicate the need for improved medicines. Cysteine proteases cruzain and rhodesain are validated targets for treatment of Chagas disease and human African trypanosomiasis. Previous studies reported a benzimidazole series as potent cruzain inhibitors. Results & methodology: Considering the high similarity between these proteases, we evaluated 40 benzimidazoles against rhodesain. We describe their structure-activity relationships (SAR), revealing trends similar to those observed for cruzain and features that lead to enzyme selectivity. This series comprises noncovalent competitive inhibitors (best Ki = 0.21 μM against rhodesain) and micromolar activity against Trypanosoma brucei brucei. A cheminformatics analysis confirms scaffold novelty, and the inhibitors described have favorable predicted physicochemical properties. Conclusion: Our results support this series as a starting point for new human African trypanosomiasis medicines.

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