scholarly journals Establishment of an in vitro culture system to study the developmental biology of Onchocerca volvulus with implications for anti-Onchocerca drug discovery and screening

2021 ◽  
Vol 15 (2) ◽  
pp. e0008513
Author(s):  
Narcisse V. T. Gandjui ◽  
Abdel J. Njouendou ◽  
Eric N. Gemeg ◽  
Fanny F. Fombad ◽  
Manuel Ritter ◽  
...  
Keyword(s):  
Culture System ◽  
Early Stage ◽  
Mating Behaviour ◽  
Sub Saharan Africa ◽  
Onchocerca Volvulus ◽  
Nodule Formation ◽  
Feeder Cells ◽  
Culture Systems ◽  
Sub Saharan

Background Infections with Onchocerca volvulus nematodes remain a threat in Sub-Saharan Africa after three decades of ivermectin mass drug administration. Despite this effort, there is still an urgent need for understanding the parasite biology especially the mating behaviour and nodule formation as well as the development of more potent drugs that can clear the developmental (L3, L4, L5) and adult stages of the parasite and inhibit parasite reproduction and behaviour. Methodology/Principal findings Prior to culture, freshly harvested O. volvulus L3 larvae from dissected Simulium damnosum flies were purified by centrifugation using a 30% Percoll solution to eliminate fly tissue debris and contaminants. Parasites were cultured in both cell-free and cell-based co-culture systems and monitored daily by microscopic visual inspection. Exhausted culture medium was replenished every 2–3 days. The cell-free culture system (DMEM supplemented with 10% NCS) supported the viability and motility of O. volvulus larvae for up to 84 days, while the co-culture system (DMEM supplemented with 10% FBS and seeded on LLC-MK2 feeder cells) extended worm survival for up to 315 days. Co-culture systems alone promoted two consecutive parasite moults (L3 to L4 and L4 to L5) with highest moulting rates (69.2±30%) observed in DMEM supplemented with 10% FBS and seeded on LLC-MK2 feeder cells, while no moult was observed in DMEM supplemented with 10% NCS and seeded on LEC feeder cells. In DMEM supplemented with 10% FBS and seeded on LLC-MK2 feeder cells, O. volvulus adult male worms attached to the vulva region of adult female worms and may have mated in vitro. Apparent early initiation of nodulogenesis was observed in both DMEM supplemented with 10% FBS and seeded on LLC-MK2 and DMEM supplemented with 10% NCS and seeded on LLC-MK2 systems. Conclusions/Significance The present study describes an in vitro system in which O. volvulus L3 larvae can be maintained in culture leading to the development of adult stages. Thus, this in vitro system may provide a platform to investigate mating behaviour and early stage of nodulogenesis of O. volvulus adult worms that can be used as additional targets for macrofilaricidal drug screening.

scholarly journals Establishment of an in vitro culture system to study the developmental biology (growth, mating and nodule formation) of Onchocerca volvulus with implications for anti-onchocerca drug discovery and screening

2020 ◽  
Author(s):  
Narcisse Victor T. Gandjui ◽  
Abdel Jelil Njouendou ◽  
Eric Njih Gemeg ◽  
Fanny Fri Fombad ◽  
Manuel Ritter ◽  
...  
Keyword(s):  
Developmental Biology ◽  
Drug Discovery ◽  
Culture System ◽  
Sub Saharan Africa ◽  
Onchocerca Volvulus ◽  
Nodule Formation ◽  
Behavioural Pattern ◽  
Culture Systems ◽  
Sub Saharan

AbstractBackgroundInfections with Onchocerca volvulus nematodes remain a threat in Sub-Saharan Africa after two decades of ivermectin mass drug administration. Despite this effort, there is still an urgent need for understanding the parasite biology, especially mating behaviour and nodule formation, as well as development of more potent drugs that can clear the developmental (L3, L4, L5) and adult stages of the parasite and inhibit parasite’s reproductive and behavioural pattern.Methodology/Principal FindingsPrior to culture, freshly harvested O. volvulus L3 larvae from dissected Simulium were purified by centrifugation using a 30% Percoll solution to eliminate fly tissue debris and contaminants. Parasites were cultured in both cell-free and cell-based co-culture systems, and monitored daily by microscopic visual inspection. Exhausted culture medium was replenished every 2–3 days. The cell-free culture system supported the viability and motility of O. volvulus larvae for up to 84 days (DMEM–10%NCS), while the co-culture system (DMEM–10%FBS–LLC-MK2) extended the worm survival period to 315 days. Co-culture systems alone promoted the two consecutive parasite moults (L3 to L4 and L4 to L5) with highest moulting rates observed in DMEM–10%FBS–LLC-MK2 (69.2±30 %), while no moult was observed in DMEM–10%NCS–LEC condition. O. volvulus adult worms mating and even mating competitions were observed in DMEM–10% FBS –LLC-MK2 co-culture system. Early nodulogenesis was observed in both DMEM–10% FBS–LLC-MK2 and DMEM– 10%NCS–LLC-MK2 systems.Conclusions/SignificanceThe present study describes an in vitro system in which O. volvulus L3 larvae can be maintained in culture leading to the development of reproductive adult stages. Thus, this platform gives potential for the investigation of mating, mating competition and early stage of nodulogenesis of O. volvulus adult worms that can be used as additional targets for onchocercacidal drug screening.Author summaryRiver blindness affects people living in mostly remote and underserved rural communities in some of the poorest areas of the world. Although significant efforts have been achieved towards the reduction of disease morbidity, onchocerciasis still affect million of people in Sub-Saharan Africa. The current control strategy is the annual mass administration of ivermectin which have accumulated several drawbacks overtime: as the sole microfilaricidal action of the drug, very long treatment period (15-17 years) and reports of ivermectin losing its efficacy; Therefore, raising the urgent need for new onchocercacidal molecules. Our study has established an in vitro platform capable of supporting the growth and development of all developmental stages of O. volvulus (L3 infective stage, L4, L5 and adult worms), moreover the platform provided more insight on O. volvulus adult worms reproductive and behavioural pattern. Our findings provide more avenues for mass production of different parasite stages, the investigation of parasite developmental biology and the identification of targets for drug discovery against different phases of development of this filaria parasite

scholarly journals Schistosoma mansoni eggs induce Wnt/β-catenin signaling and activate the protooncogene c-Jun in human and hamster colon

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jakob Weglage ◽  
Friederike Wolters ◽  
Laura Hehr ◽  
Jakob Lichtenberger ◽  
Celina Wulz ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Colorectal Carcinogenesis ◽  
Sub Saharan Africa ◽  
Interleukin 4 ◽  
Health Burden ◽  
Sub Saharan ◽  
Considerable Morbidity ◽  
First Time

AbstractSchistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia, in sub-Saharan Africa, and particularly also in Europe. The WHO describes an increasing global health burden with more than 290 million people threatened by the disease and a potential to spread into regions with temperate climates like Corsica, France. The aim of our study was to investigate the influence of S. mansoni infection on colorectal carcinogenic signaling pathways in vivo and in vitro. S. mansoni infection, soluble egg antigens (SEA) and the Interleukin-4-inducing principle from S. mansoni eggs induce Wnt/β-catenin signaling and the protooncogene c-Jun as well as downstream factor Cyclin D1 and markers for DNA-damage, such as Parp1 and γH2a.x in enterocytes. The presence of these characteristic hallmarks of colorectal carcinogenesis was confirmed in colon biopsies from S. mansoni-infected patients demonstrating the clinical relevance of our findings. For the first time it was shown that S. mansoni SEA may be involved in the induction of colorectal carcinoma-associated signaling pathways.

Supplementation of c-type natriuretic peptide during in vitro growth period benefits the development of murine preantral follicles

Zygote ◽  
2020 ◽  
pp. 1-5
Author(s):  
Li Ang ◽  
Cao Haixia ◽  
Li Hongxia ◽  
Li Ruijiao ◽  
Guo Xingping ◽  
...  
Keyword(s):  
Natriuretic Peptide ◽  
Granulosa Cells ◽  
Culture System ◽  
Early Stage ◽  
Developmental Competence ◽  
Control Group ◽  
Follicle Development ◽  
Control Groups ◽  
Preantral Follicles

Summary The present study investigated the effects of c-type natriuretic peptide (CNP) on the development of murine preantral follicles during in vitro growth (IVG). Preantral follicles isolated from ovaries of Kunming mice were cultured in vitro. In the culture system, CNP was supplemented in the experimental groups and omitted in the control groups. In Experiment 1, CNP was only supplemented at the early stage and follicle development was evaluated. In Experiments 2 and 3, CNP was supplemented during the whole period of in vitro culture. In Experiment 2, follicle development and oocyte maturity were evaluated. In Experiment 3, follicle development and embryo cleavage after in vitro fertilization (IVF) were assessed. The results showed that in the control groups in all three experiments, granulosa cells migrated from within the follicle and the follicles could not reach the antral stage. In the experimental groups in all three experiments, no migration of granulosa cells was observed and follicle development was assessed as attaining the antral stage, which was significantly superior to that of the control group (P < 0.0001). Oocyte meiotic arrest was effectively maintained, hence giving good developmental competence. In conclusion, CNP supplementation in the culture system during IVG benefited the development of murine preantral follicles.

scholarly journals Adipose and Muscle Cell Co-Culture System: A Novel In Vitro Tool to Mimic the In Vivo Cellular Environment

Biology ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
Palaniselvam Kuppusamy ◽  
Dahye Kim ◽  
Ilavenil Soundharrajan ◽  
Inho Hwang ◽  
Ki Choon Choi
Keyword(s):  
Drug Development ◽  
Culture System ◽  
Cell Types ◽  
Culture Cell ◽  
In Vitro Techniques ◽  
Culture Systems ◽  
Complex Interactions ◽  
Cellular Environment

A co-culture system allows researchers to investigate the complex interactions between two cell types under various environments, such as those that promote differentiation and growth as well as those that mimic healthy and diseased states, in vitro. In this paper, we review the most common co-culture systems for myocytes and adipocytes. The in vitro techniques mimic the in vivo environment and are used to investigate the causal relationships between different cell lines. Here, we briefly discuss mono-culture and co-culture cell systems and their applicability to the study of communication between two or more cell types, including adipocytes and myocytes. Also, we provide details about the different types of co-culture systems and their applicability to the study of metabolic disease, drug development, and the role of secretory factors in cell signaling cascades. Therefore, this review provides details about the co-culture systems used to study the complex interactions between adipose and muscle cells in various environments, such as those that promote cell differentiation and growth and those used for drug development.

Drug activity against Onchocerca gutturosa males in vitro: a model for chemotherapeutic research on onchocerciasis

1987 ◽  
Vol 61 (4) ◽  
pp. 271-281 ◽  
Author(s):  
Simon Townson ◽  
C. Connelly ◽  
A. Dobinson ◽  
R. Muller
Keyword(s):  
Culture System ◽  
Serum Proteins ◽  
Good Condition ◽  
Calf Serum ◽  
New Drugs ◽  
Foetal Calf Serum ◽  
Partial Recovery ◽  
Feeder Cells ◽  
Compound Identification

ABSTRACTAn in vitro system for chemotherapeutic research using adult male Onchocerca gutturosa has been developed as a model for O. volvulus. Using a culture system consisting of medium MEM+10% heat inactivated foetal calf serum (IFCS)+LLCMK2 (monkey kidney) feeder cells in an atmosphere of 5% CO2 in air, we examined the effects of a range of antiparasitic drugs on worm motility. Ivermectin, levamisole, furapyrimidone, Mel W, chloroquine, metrifonate, flubendazole, amoscanate and the Ciba-Geigy compounds CGP 6140, CGP 20′376 and CGI 17658 either immobilized or significantly reduced motility levels at a concentration of 5x10−5M or less within a 7-day period. Worms were affected at very low concentrations by ivermectin (effective conc. to reduce motility levels to 50% of controls, 3.14x10−8M), levamisole (7.95x10−8M), CGP 6140 (8.87x10−9M) and CGP 20′376 (2.78x10−8M). Difficulties were experienced in accurately repeating the immotile endpoint for levamisole due to an inconsistent partial recovery of motility. Over a 7-day period diethylcarbamazine had little effect on motility levels, while suramin caused a slight increase in activity compared to controls at some timepoints. Subsequent experiments demonstrated some differences in drug efficacy depending on the presence or absence of serum and feeder cells in the culture system probably because of drug avidly binding to serum proteins. However, serum and cells were found to be essential ingredients of the culture system to maintain worms in good condition, indicating that new drugs should be evaluated both in the presence and absence of serum and cells. Comparisons were made between the responses of O. gutturosa and Brugia pahangi to certain drugs and these species were found to significantly differ in their sensitivities to ivermectin and a novel compound (Wellcome), indicating that Onchocerca parasites should be used wherever possible for compound identification and development intended for the treatment of onchocerciasis. The in vitro system described here, using male O. gutturosa, provides a basis for further research and a practical alternative to O. volvulus.

scholarly journals Iron nanoparticles on growth and acclimatization of Chrysanthemum morifolium Ramat. cv. "Jimba" in different culture systems

2020 ◽  
Vol 18 (2) ◽  
pp. 307-319
Author(s):  
Hoang Thanh Tung ◽  
Truong Hoai Phong ◽  
Phan Le Ha Nguyen ◽  
Luong Thien Nghia ◽  
Ha Thi My Ngan ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Enzyme ◽  
Chlorophyll A ◽  
Culture System ◽  
Iron Nanoparticles ◽  
Cultivated Plants ◽  
Ms Medium ◽  
Culture Systems ◽  
Optimal Activity

In plant tissue culture, iron nanoparticles (FeNPs) was one of the first types of nano to be used in plants. Previous reports have identified the effect of FeNPs on many different plant species. In this study, FeNPs was used to replace Fe-EDTA in MS (Murashige, Skoog, 1962) medium to assess their effects on growth, chlorophyll (a, b and a+b) accumulation, antioxidant activity of ascorbate peroxidase (APX) and superoxide dismutase (SOD) enzymes, and acclimatization in greenhouse conditions in different culture systems (in vitro solid, in vitro hydroponic and microponic culture). The obtained results show that FeNPs added to MS medium was higher growth, chlorophyll (a, b and a+b) content, antioxidant activity of SOD and APX enzymes than Fe-EDTA in MS medium as control treatment. The effect of FeNPs are differences between culture systems. In vitro solid and microponic culture systems, the optimal concentration is 75 mM FeNPs and in vitro hydroponic culture system is 100 mM FeNPs. The optimal activity of the antioxidant enzyme SOD (35.04 U.mg−1 prot) obtained in the roots of cultured plants in microponic culture system; meanwhile, the optimal activity of the antioxidant enzyme APX (2.11 μmol.min−1.mg−1 prot) obtained in leaves cultivated in solid culture system. The plantlets derived from MS medium added FeNPs were transfered into greenhouse conditions, the microponic cultivated plants supplemented with FeNPs at a concentration of 100 mM gave the highest survival rate (94.67%). The results of this study showed that FeNPs can replace Fe-EDTA salt in MS medium, and iron deficiency in culture media will reduce chlorophyll content.

scholarly journals THE ROLE OF FINANCIAL DEVELOPMENT AND INSTITUTIONAL QUALITY ON ENVIRONMENTAL SUSTAINABILITY IN SUB-SAHARAN AFRICAN COUNTRIES

2018 ◽  
Vol 6 (9) ◽  
pp. 156-177
Author(s):  
Aliyu Alhaji Jibrilla
Keyword(s):  
Financial Development ◽  
Environmental Sustainability ◽  
Carbon Dioxide Emissions ◽  
Early Stage ◽  
Institutional Quality ◽  
Environmental Conservation ◽  
Sub Saharan Africa ◽  
African Countries ◽  
Pooled Mean Group ◽  
Sub Saharan

This study addresses the question of financial development and institutional quality influence on the environmental sustainability of some 13 countries from the sub-Saharan Africa. Relying upon pooled mean group (PMG) for panel data, we provide evidence which suggest that both financial development and institutional quality are statistically significant determinants of per capita carbon dioxide emissions in the region. More specifically, we found that without healthy institutions and sound financial system sub-Saharan African countries might not avoid environmental degradation experienced by advanced nations during their early stage of economic progress. Our results also support the EKC hypothesis in the region.  In addition, the paper also shows that more openness to FDI inflows is good for the environment across the SSA. These findings suggest the need for institutional and financial service reform that supports robust environmental conservation.

scholarly journals Sulfamethoxazole Susceptibility of Mycobacterium tuberculosis Isolates from HIV-Infected Ugandan Adults with Tuberculosis Taking Trimethoprim-Sulfamethoxazole Prophylaxis

2015 ◽  
Vol 59 (9) ◽  
pp. 5844-5846 ◽  
Author(s):  
Sam Ogwang ◽  
Caryn E. Good ◽  
Brenda Okware ◽  
Mary Nsereko ◽  
Michael R. Jacobs ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Multidrug Resistant ◽  
Sub Saharan Africa ◽  
Content Type ◽  
Pulmonary Tb ◽  
Resistant Tuberculosis ◽  
Multidrug Resistant Tuberculosis ◽  
Sub Saharan

ABSTRACTAdditional drugs are needed for the treatment of multidrug-resistant tuberculosis (TB). Sulfamethoxazole has been shown to havein vitroactivity againstMycobacterium tuberculosis; however, there is concern about resistance given the widespread use of trimethoprim-sulfamethoxazole prophylaxis among HIV-infected patients in sub-Saharan Africa. Thirty-eight of 40Mycobacterium tuberculosisisolates (95%) from pretreatment sputum samples from Ugandan adults with pulmonary TB, including HIV-infected patients taking trimethoprim-sulfamethoxazole prophylaxis, were susceptible with MICs of ≤38.4 μg/ml.

Selecting indicators of drought impacts: the importance of context

2021 ◽  
Author(s):  
Sarra Kchouk ◽  
Pieter van Oel ◽  
Lieke Melsen
Keyword(s):  
Early Stage ◽  
Contextual Information ◽  
Geographic Area ◽  
Early Warning Systems ◽  
Sub Saharan Africa ◽  
Drought Impacts ◽  
Direct Linkage ◽  
Drought Indicators ◽  
Sub Saharan ◽  
Drought Early Warning

&lt;p&gt;Drought Early Warning Systems (DEWS) and Drought Monitoring Systems (DMS) are the principal tools used to tackle drought at an early stage and reduce the possibility of harm or loss. They are based on the use of drought indicators attributed to either : meteorological, agricultural and hydrological drought. This means that it is mostly hydro-climatic variables that are used to determine the onset, end and severity of a drought. &amp;#160;Drought impacts are rarely continuously monitored or even not included in DEWS and DMS. In this configuration, the likelihood of experiencing impacts is linearly linked to the severity of climatic features only. The aim of our study is to question the direct linkage between the delivery of hydro-climatic information and the detection of drought impacts and their severity. We reviewed scientific literature on drought drivers and impacts and analyzed how these two compare. We conducted a bibliometric analysis based on 4000+ scientific studies sorted by geographic area in which selected (i) drought indicators and (ii) impacts of drought were mentioned. Our review points toward an attachment to a conceptual view of drought by the main and broader use of meteorological (computed and remotely sensed) drought indicators. Studies reporting impacts related to food and water securities are more localized, respectively in Sub-Saharan Africa and Australasia. This mismatch suggests a tendency to translate hydroclimatic indicators of drought directly into impacts while neglecting relevant local contextual information. With the aim of sharpening the information provided by DEWS and DMS, we argue in favor of an additional consideration of drought indicators oriented towards the SDGs.&lt;/p&gt;

166 EFFECT OF INDIVIDUAL CULTURE SYSTEM ON IN VITRO DEVELOPMENT OF IN VITRO-MATURED - IN VITRO-FERTILIZED BOVINE EMBRYOS

2012 ◽  
Vol 24 (1) ◽  
pp. 195
Author(s):  
R. Nishii ◽  
K. Imai ◽  
H. Koyama ◽  
O. Dochi
Keyword(s):  
Culture System ◽  
Calf Serum ◽  
Control Culture ◽  
Total Cell ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Culture Systems ◽  
Individual Culture ◽  
Single Culture

An individual in vitro culture system for bovine embryo needs to be developed for the study of embryo developmental competence. The objective of this study was to examine the effect of individual culture systems on the development of in vitro-matured–in vitro-fertilized bovine embryos. Two individual culture systems were compared. Cumulus–oocyte complexes (COC) were collected by aspiration of ovarian follicles (diameter, 2 to 5 mm) obtained from a local abattoir. The COC were matured in TCM-199 supplemented with 5% calf serum and 0.02 AU mL–1 of FSH. Groups of 20 COC were incubated in 100-μL droplets of IVM media at 38.5°C under an atmosphere of 5% CO2 for 20 h. After 18 h of gamete co-culture (3 × 106 sperm mL–1), the presumptive zygotes were cultured in CR1aa medium supplemented with 5% calf serum at 38.5°C under an atmosphere of 5% CO2, 5% O2 and 90% N2 for 9 days (fertilization = Day 0). The presumptive zygotes were randomly assigned to 1 of the following 3 treatments: single culture (1 zygote was cultured in a 5-μL droplet), well-of-the-well (WOW; Sugimura et al. 2010 Biol. Reprod. 83, 970–978) culture (25 zygotes were cultured individually in each 125-μL droplet) and control culture (25 zygotes were cultured in a 125-μL droplet). Embryo development was evaluated for cleavage and blastocyst rates, on Day 2 and Day 7 to 9 after IVF, respectively. The rates of development up to the blastocyst stage and total cell number in the blastocysts, determined by an air-drying method, were investigated. The cleavage and blastocyst rates were analysed by the chi-square test and the total cell numbers were analysed by ANOVA. The cleavage rates were significantly higher in the control and WOW groups than in the single-culture group (P < 0.01) and the blastocyst rates were significantly lower in the single-culture group than in the control culture group (P < 0.05; Table 1). The total cell numbers (mean ± s.d.) of blastocysts did not significantly differ between the single culture (154.6 ± 21.8), control culture (155.2 ± 22.5) and WOW culture (159.8 ± 27.0) groups. These results indicate that although the blastocyst rate was lower in the single-culture system than in the WOW or group culture system, in vitro-matured–in vitro-fertilized bovine embryos can be cultured using the single-culture system. Moreover, the quality of blastocysts developed by the single-culture system is the same as that of blastocysts developed using the other 2 culture systems. Table 1.Effect of different culture methods for bovine embryo development

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