scholarly journals Chasing the genes that control resistance to gastrointestinal nematodes

2003 ◽  
Vol 77 (2) ◽  
pp. 99-109 ◽  
Author(s):  
J.M. Behnke ◽  
F. Iraqi ◽  
D. Menge ◽  
R.L. Baker ◽  
J. Gibson ◽  
...  
Keyword(s):  
Immune Response ◽  
Egg Production ◽  
Allelic Variation ◽  
Control Strategies ◽  
Domestic Animals ◽  
Gastrointestinal Nematodes ◽  
Comparative Genomic ◽  
Human Beings ◽  
Signalling Molecules ◽  
Mhc Genes

AbstractThe host-protective immune response to infection with gastrointestinal (GI) nematodes involves a range of interacting processes that begin with recognition of the parasite's antigens and culminate in an inflammatory reaction in the intestinal mucosa. Precisely which immune effectors are responsible for the loss of specific worms is still not known although many candidate effectors have been proposed. However, it is now clear that many different genes regulate the response and that differences between hosts (fast or strong versus slow or weak responses) can be explained by allelic variation in crucial genes associated with the gene cascade that accompanies the immune response and/or genes encoding constitutively expressed receptor/signalling molecules. Major histocompatibility complex (MHC) genes have been recognized for some time as decisive in controlling immunity, and evidence that non-MHC genes are equally, if not more important in this respect has also been available for two decades. Nevertheless, whilst the former have been mapped in mice, only two candidate loci have been proposed for non-MHC genes and relatively little is known about their roles. Now, with the availability of microsatellite markers, it is possible to exploit linkage mapping techniques to identify quantitative trait loci (QTL) responsible for resistance to GI nematodes. Four QTL for resistance to Heligmosomoides polygyrus, and additional QTL affecting faecal egg production by the worms and the accompanying immune responses, have been identified. Fine mapping and eventually the identification of the genes (and their alleles) underlying QTL for resistance/susceptibility will permit informed searches for homologues in domestic animals, and human beings, through comparative genomic maps. This information in turn will facilitate targeted breeding to improve resistance in domestic animals and, in human beings, focused application of treatment and control strategies for GI nematodes.

Effects of control strategy on the activation of unwanted intrusive thoughts

2020 ◽  
Author(s):  
Sicong Liu ◽  
Jonathan Folstein ◽  
Lawrence Gregory Appelbaum ◽  
Gershon Tenenbaum
Keyword(s):  
Control Strategies ◽  
Working Memory Capacity ◽  
Intrusive Thoughts ◽  
Control Process ◽  
Event Related Potentials ◽  
Human Beings ◽  
Opposite Pattern ◽  
Thought Control ◽  
Related Potentials ◽  
And Performance

Although the unwanted intrusive thoughts (UITs) exist widely in human beings and show similar characteristics between clinical and nonclinical forms, its control process remains unclear. Thoughts of choking under pressure, particularly among high-achieving athletes, represent a meaningful UIT type due to their psychological and performance-related impact. Taking a dynamic view of UIT control process, this study tested the effect of thought-control strategies among sub-elite to elite athletes, applied to individualized choking thoughts. Ninety athletes recollected recent athletic choking experiences prior to being randomized into one of three thought control interventions using strategies of either acceptance, passive monitoring (control), or suppression. To control for individual differences, athletes’ working memory capacity was measured and modeled as a covariate at baseline. The activation of choking thoughts during and after the intervention was gauged through multiple measurement approaches including conscious presence in mind, priming, and event-related potentials (P3b and N400 amplitudes). Results indicated that, relative to the control, suppression led to enhanced priming and reduced conscious presence of choking thoughts, whereas acceptance resulted in an opposite pattern of reduced priming and increased conscious presence of choking thoughts. In addition, thought-related stimuli elicited less negative-going N400 amplitudes and more positive-going P3b amplitudes than control stimuli. These findings advance understandings of the control mechanism underpinning UITs, and generate applied implications regarding UIT control in high-risk populations such as those with athletic expertise.

scholarly journals Molecular detection and genetic diversity of Leucocytozoon sabrazesi in chickens in Thailand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Runglawan Chawengkirttikul ◽  
Witchuta Junsiri ◽  
Amaya Watthanadirek ◽  
Napassorn Poolsawat ◽  
Sutthida Minsakorn ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Egg Production ◽  
Control Strategies ◽  
Amino Acid Sequences ◽  
Economic Losses ◽  
Nested Polymerase Chain Reaction ◽  
Blood Samples ◽  
Tropical Regions ◽  
Vaccination Programs ◽  
High Entropy

AbstractLeucocytozoon sabrazesi is the intracellular protozoa of leucocytozoonosis, which is transmitted by the insect vectors and affects chickens in most subtropical and tropical regions of the globe, except South America, and causing enormous economic losses due to decreasing meat yield and egg production. In this study, L. sabrazesi gametocytes have been observed in the blood smears, and molecular methods have been used to analyse the occurrence and genetic diversity of L. sabrazesi in blood samples from 313 chickens raised in northern, western and southern parts of Thailand. The nested polymerase chain reaction (nested PCR) assay based on the cytb gene revealed that 80.51% (252/313) chickens were positive of L. sabrazesi. The phylogenetic analysis indicated that L. sabrazesi cytb gene is conserved in Thailand, showed 2 clades and 2 subclades with similarity ranged from 89.5 to 100%. The diversity analysis showed 13 and 18 haplotypes of the sequences from Thailand and from other countries, respectively. The entropy analyses of nucleic acid sequences showed 26 high entropy peaks with values ranging from 0.24493 to 1.21056, while those of amino acid sequences exhibited 5 high entropy peaks with values ranging from 0.39267 to 0.97012. The results; therefore, indicate a high molecular occurrence of L. sabrazesi in chicken blood samples with the associated factors that is statistically significant (p < 0.05). Hence, our results could be used to improve the immunodiagnostic methods and to find appropriate preventive control strategies or vaccination programs against leucocytozoonosis in order to mitigate or eliminate the harmful impact of this infection on chicken industry.

scholarly journals Mycobacterium tuberculosis adhesins: potential biomarkers as anti-tuberculosis therapeutic and diagnostic targets

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1821-1831 ◽  
Author(s):  
Viveshree S. Govender ◽  
Saiyur Ramsugit ◽  
Manormoney Pillay
Keyword(s):  
Immune Response ◽  
Mycobacterium Tuberculosis ◽  
Control Strategies ◽  
Host Cells ◽  
Tuberculosis Control ◽  
Surface Molecules ◽  
Host Pathogen Interaction ◽  
Bacterial Aggregation ◽  
Insight Into

Adhesion to host cells is a precursor to host colonization and evasion of the host immune response. Conversely, it triggers the induction of the immune response, a process vital to the host’s defence against infection. Adhesins are microbial cell surface molecules or structures that mediate the attachment of the microbe to host cells and thus the host–pathogen interaction. They also play a crucial role in bacterial aggregation and biofilm formation. In this review, we discuss the role of adhesins in the pathogenesis of the aetiological agent of tuberculosis, Mycobacterium tuberculosis. We also provide insight into the structure and characteristics of some of the characterized and putative M. tuberculosis adhesins. Finally, we examine the potential of adhesins as targets for the development of tuberculosis control strategies.

scholarly journals Optimal control of acute myeloid leukaemia

2018 ◽  
Author(s):  
Jesse A Sharp ◽  
Alexander P Browning ◽  
Tarunendu Mapder ◽  
Kevin Burrage ◽  
Matthew J Simpson
Keyword(s):  
Optimal Control ◽  
Immune Response ◽  
Acute Myeloid Leukaemia ◽  
Myeloid Leukaemia ◽  
Cell Model ◽  
Control Strategies ◽  
Treatment Strategies ◽  
Numerical Convergence ◽  
Stem Cell Model ◽  
Acute Myeloid

AbstractAcute myeloid leukaemia (AML) is a blood cancer affecting haematopoietic stem cells. AML is routinely treated with chemotherapy, and so it is of great interest to develop optimal chemotherapy treatment strategies. In this work, we incorporate an immune response into a stem cell model of AML, since we find that previous models lacking an immune response are inappropriate for deriving optimal control strategies. Using optimal control theory, we produce continuous controls and bang-bang controls, corresponding to a range of objectives and parameter choices. Through example calculations, we provide a practical approach to applying optimal control using Pontryagin’s Maximum Principle. In particular, we describe and explore factors that have a profound influence on numerical convergence. We find that the convergence behaviour is sensitive to the method of control updating, the nature of the control, and to the relative weighting of terms in the objective function. All codes we use to implement optimal control are made available.

scholarly journals The complex, bidirectional role of extracellular vesicles in infection

2021 ◽  
Author(s):  
Joni Renee White ◽  
Priscila Dauros-Singorenko ◽  
Jiwon Hong ◽  
Frédérique Vanholsbeeck ◽  
Anthony Phillips ◽  
...  
Keyword(s):  
Immune Response ◽  
Extracellular Vesicles ◽  
Bacterial Pathogens ◽  
Host Cells ◽  
Signalling Molecules ◽  
Host Pathogen ◽  
Domains Of Life

Cells from all domains of life release extracellular vesicles (EVs), packages that carry a cargo of molecules that participate in communication, co-ordination of population behaviours, virulence and immune response mechanisms. Mammalian EVs play an increasingly recognised role to fight infection, yet may also be commandeered to disseminate pathogens and enhance infection. EVs released by bacterial pathogens may deliver toxins to host cells, signalling molecules and new DNA to other bacteria, and act as decoys, protecting infecting bacteria from immune killing. In this review, we explore the role of EVs in infection from the perspective of both the pathogen and host, and highlight their importance in the host/pathogen relationship. We highlight proposed strategies for EVs in therapeutics, and call attention to areas where existing knowledge and evidence is lacking.

The immune response and the evaluation of acquired immunity against gastrointestinal nematodes in cattle: a review

Parasitology ◽  
2000 ◽  
Vol 120 (7) ◽  
pp. 25-42 ◽  
Author(s):  
E. CLAEREBOUT ◽  
J. VERCRUYSSE
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Protective Immunity ◽  
Current Knowledge ◽  
Small Ruminants ◽  
Gastrointestinal Nematodes ◽  
Gastrointestinal Parasites ◽  
Acquired Immunity ◽  
Immunological Parameters ◽  
Iga Response

The present review discusses the immune responses to gastrointestinal nematodes in cattle and the different immunological and parasitological parameters used to assess acquired immunity. Measuring acquired immunity to gastrointestinal nematodes in cattle (e.g. for the evaluation of candidate parasite vaccines) is hampered by the limited understanding of bovine immune responses against gastrointestinal parasites. In this paper the available data on protective immunity against gastrointestinal nematodes, and especially Ostertagia ostertagi, in cattle are compared with the current knowledge of protective immune responses against gastrointestinal nematodes in rodent models and small ruminants. In contrast to the immune response in mice, which is controlled by T helper 2 (Th2) lymphocytes and results in mast cell- or goblet cell- mediated expulsion of adult worms, bovine immune responses to O. ostertagi do not show a clear Th2 cytokine profile, nor do they result in rapid expulsion of the parasite. The first manifestation of immunity to O. ostertagi in calves is a reduction of worm fecundity, possibly regulated by the local IgA response. Worm numbers are only reduced after a prolonged period of host–parasite contact, and there are indications that O. ostertagi actively suppresses the host's immune response. Until the mechanisms of protective immunity against O. ostertagi are revealed, the use of immunological parameters to estimate acquired immunity in cattle is based on their correlation with parasitological parameters and on extrapolation from rodent and small ruminant models. Assessing the resistance of calves against a challenge infection by means of parasitological parameters is probably still the most accurate way to measure acquired immunity against gastrointestinal nematodes.

Anthelmintic Drugs Resistance of Gastrointestinal Nematodes of Naturally Infected Goats in Haramaya, Ethiopia

2019 ◽  
Author(s):  
Anteneh Wondimu ◽  
Yehualashet Bayu
Keyword(s):  
Management Practices ◽  
Narrow Range ◽  
Anthelmintic Resistance ◽  
Control Strategies ◽  
Nematode Resistance ◽  
Treated Group ◽  
Gastrointestinal Nematodes ◽  
Drug Resistant ◽  
Global Threat ◽  
Anthelmintic Drugs

Abstract Background: The occurrence of anthelmintic resistance to commonly used drugs is becoming worldwide constrain in livestock production. Considering the narrow range of available drugs and slow rate of new drug development, anthelmintic resistance presents an alarming global threat demanding vigilant monitoring and management. It is likely that anthelmintic resistance of gastrointestinal goats present in Ethiopia, but little information regarding the prevalence and species of nematode resistance to drugs is available. Current study done with objective to assess anthelmintic resistance of gastrointestinal nematodes of goats to commonly used anthelmintic drugs. Results: The result of the FECRT % and lower 95% confidence limit reported the presence of anthelmintic resistance for tested drugs; albendazole (41.5%, 36.9), tetraclozan (69.5%, 66.1), tetramisole (91.1%, 87.4) and ivermectin (43%, 38.2) respectively. Trichostrongylus spp, Teladorsagia spp and Haemonchus spp showed anthelmintic resistance for all tested drugs. Coproculture from different treated group revealed of Trichostrongylus spp (69.2% in ivermectin and 59.6% in albendazole) was the predominant nematode followed by Teladorsagia spp (21.9% in albendazole and 14.7% in ivermectin). In tetraclozan treatment group, Trichostrongylus spp (42%) and Teladorsagia spp (41.3%) were comparable, followed by Haemonchus spp (13%). In group treated with tetramisole, Teladorsagia spp (54.3%) was the major nematode detected followed by Trichostrongylus spp (25.7%) and Haemonchus spp (11.4%). Conclusions: The study demonstrated the presence of multi-drug resistant nematodes mainly Trichostrongylus spp, Teladorsagia spp and Haemonchus spp. Control strategies including management practices of pasture rotation, supplementary feeding and encouraging traditional nematode control methods. Further studies covering wider areas of Ethiopia and mechanism of nematode resistance need to be studied in future.

scholarly journals Asymptomatic malaria: building bridges with communities through patients in Côte d’Ivoire

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
A Hounsa ◽  
D Yao ◽  
A R Attia ◽  
M Gokpéya ◽  
K J Sackou ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Control Strategies ◽  
Clinical Signs ◽  
Domestic Animals ◽  
Asymptomatic Malaria ◽  
Cote D’Ivoire ◽  
Côte D'ivoire ◽  
Household Members

Abstract Background In malaria-endemic areas, asymptomatic carriers are a reservoir of parasites that contribue to the persistence of malaria transmission. In Côte d’Ivoire, this situation is poorly documented. The objective of our study was to assess the frequency and socio-environmental factors associated with asymptomatic malaria in the town of Assuefry, located in the northeast of Côte d’Ivoire, a region where malaria prevalence remains high. Methods A cross-sectional study in two stages was conducted from October to December 2018, first at the Urban Health Center (UHC) in Assuefry and then in the households. The sample size calculated for patients was 162 extrapolated to 201 people. All persons received at the CSU who had clinical symptoms of malaria and a positive Rapid Diagnostic Test (RDT) were included. In the households of these index subjects, a follow-up survey allowed active RDT screening for malaria among all household members with no clinical signs of malaria. The socio-environmental factors taken into account were: the area of residence (urban or peri-urban), domestic animals husbandry, water storage at home, nearby garbage dump, wastewater collection and disposal system, type of housing and number of people in the household. Results The frequency of asymptomatic malaria was 341 (38.8%) out of 879 household members visited. Both female and male gender was concerned (51% vs. 49%). The 5 to 25 years old group concentrated nearly 82% of all cases. Only domestic animals husbandry was associated with asymptomatic malaria at the household level (p = 0.021). Conclusions The high frequency of asymptomatic malaria found in this study is a challenge for the National Malaria Control Program in Côte d’Ivoire. This should be taken into account while organizing control strategies. Key messages The frequency of asymptomatic malaria in Côte d’Ivoire is high. Control strategies must take into account in the guidelines the challenges of detecting and treating asymptomatic malaria. For the judicious use of antimalarial drugs, any subject with a positive RDT without clinical signs of malaria should receive a ‘Drop - Thick’ before treatment.

The immune response in human beings to Amb a 1 linked to ISS DNA

2004 ◽  
Vol 113 (6) ◽  
pp. 1011-1011
Author(s):  
Donald Y.M. Leung ◽  
Harold S. Nelson ◽  
Stanley J. Szefler ◽  
William W. Busse
Keyword(s):  
Immune Response ◽  
Human Beings ◽  
Amb A 1

Targeting intracellular mediators of pattern-recognition receptor signalling to adjuvant vaccination

2007 ◽  
Vol 35 (6) ◽  
pp. 1501-1503 ◽  
Author(s):  
J. Wales ◽  
E. Andreakos ◽  
M. Feldmann ◽  
B. Foxwell
Keyword(s):  
Immune Response ◽  
Pattern Recognition ◽  
Systemic Toxicity ◽  
Pattern Recognition Receptor ◽  
Intracellular Signalling ◽  
Present Review ◽  
Signalling Molecules ◽  
Receptor Signalling ◽  
Intracellular Mediators ◽  
Recognition Receptor

PRR (pattern-recognition receptor) signalling is involved early in the immune response and therefore would be attractive to target during vaccination. The use of PRR ligands has shown some success; however, toxicity and non-specificity are issues with this strategy. The targeting of PRR intracellular signalling networks would allow for greater specificity and reduced systemic toxicity. The present review examines the successes seen with overexpression or repression of PRR signalling molecules.

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