Cryptocotyle lingua in mullet, Chelon labrosus; significance of metacercarial excretory proteins in the stimulation of the immune response

1993 ◽  
Vol 67 (1) ◽  
pp. 1-9 ◽  
Author(s):  
R. A. Matthews ◽  
B. F. Matthews

Abstract‘O’ group mullet, Chelon labrosus. were experimentally infected with Cryptocotyle lingua (Heterophyidae) by tail dip in a suspension of cercariae. Metacercariae were excised after 1 and 24 hours and prepared for TEM and post-embedding immunogold labelling. Antisera to cercariae of C. lingua were raised in adult mullet by natural infection via the skin and by intra-peritoneal injection of sonicate. The membrane-bound vesicles within the syncytial lining of the metacercarial excretory vesicle were found to be intensely antigenic with both antisera: the epidermal secretory bodies type 5 within the cystogenousglands gave a positive response. Penetration gland contents were not found to be antigenic with either antiserum. Discharge of the membrane-bound vesicles coinciding with both the reorganization of the lining of the metacercarial excretory vesicle and with cyst wall formation appears to be of significance in the initiation of the host immune response. That the term ‘excretory vesicle’ in Digenea may be a misnomer is discussed in the light of current information regarding the wide range of functions attributed to this structure.

1993 ◽  
Vol 74 (4) ◽  
pp. 1484-1491 ◽  
Author(s):  
R. J. Strobel ◽  
J. A. Daubenspeck

Although respiratory-related cortical evoked potentials (CEPs) have been obtained in humans, early-latency responses have been obtained only with direct electrical stimulation of respiratory afferents. We have recorded both early and late cortical activity in response to a relatively novel stimulus consisting of a 300-ms negative pressure pulse applied to the mouth near the start of selected inspirations, when mouth pressure attained a predetermined threshold. This stimulus caused highly reproducible and rapid changes in mouth pressure and was effective in eliciting CEPs to a wide range of applied pressures. Using pulses of approximately -2 to -25 cmH2O, we obtained an early positive component with a mean latency of approximately 20 ms and a subsequent negative component at approximately 30 ms in normal subjects. Peak-to-peak amplitude varied directly, and component latencies inversely, as a function of pulse magnitude. Using -5- to -10-cmH2O stimuli, we also measured a later positive-negative-positive response with mean component latencies of 96.7 +/- 15.1, 147 +/- 14.8, and 237.6 +/- 23.5 ms, respectively. The early-latency activity was resistant to manipulations of stimulus predictability, whereas the later waves were attenuated or disappeared when load presentation was made completely predictable. We validated our method by eliminating the possibility of tactile stimulation of the lips and teeth as the origin of the evoked responses. We propose that early-latency activity derives from precortical structures and may provide a window on the functioning of respiratory afferents in normal subjects and in patients with respiratory disease.


2021 ◽  
Vol 11 ◽  
Author(s):  
Nimisha Mathur ◽  
Syed F. Mehdi ◽  
Manasa Anipindi ◽  
Monowar Aziz ◽  
Sawleha A. Khan ◽  
...  

Sepsis continues to produce widespread inflammation, illness, and death, prompting intensive research aimed at uncovering causes and therapies. In this article, we focus on ghrelin, an endogenous peptide with promise as a potent anti-inflammatory agent. Ghrelin was discovered, tracked, and isolated from stomach cells based on its ability to stimulate release of growth hormone. It also stimulates appetite and is shown to be anti-inflammatory in a wide range of tissues. The anti-inflammatory effects mediated by ghrelin are a result of both the stimulation of anti-inflammatory processes and an inhibition of pro-inflammatory forces. Anti-inflammatory processes are promoted in a broad range of tissues including the hypothalamus and vagus nerve as well as in a broad range of immune cells. Aged rodents have reduced levels of growth hormone (GH) and diminished immune responses; ghrelin administration boosts GH levels and immune response. The anti-inflammatory functions of ghrelin, well displayed in preclinical animal models of sepsis, are just being charted in patients, with expectations that ghrelin and growth hormone might improve outcomes in patients with sepsis.


2015 ◽  
Vol 11 (2) ◽  
pp. 90 ◽  
Author(s):  
Mona Mohamed Ibrahim Abdalla ◽  

Ghrelin is an orexigenic peptide predominantly secreted from the stomach and stimulates appetite and growth hormone (GH) release. Studies have provided evidence that ghrelin exercises a wide range of functions, including regulation of food intake and energy metabolism, modulation of cardiovascular function, stimulation of osteoblast proliferation and bone formation and stimulation of neurogenesis and myogenesis. In the gastrointestinal system, ghrelin affects multiple functions, including secretion of gastric acid, gastric motility and pancreatic protein output. Most of these functions have been attributed to the actions of acylated ghrelin. The balance among its secretion rate, degradation rate and clearance rate determines the circulating level of ghrelin. This review explains what ghrelin is, its physiological functions and the factors that influence its level.


2021 ◽  
Vol 11 (05) ◽  
pp. 1656-1664
Author(s):  
Vladimir M Zemskov ◽  
Andrey M Zemskov ◽  
Victoria Neymann ◽  
Konstantin N Pronko ◽  
Aliexander A Barsukov ◽  
...  

The analysis of literature data and our published results of examination of patients with a wide range of pathological processes was carried out. It has been established that polar changes in reactivity provoke the development of immune-dependent ones, which include primary and secondary immunodeficiencies, auto-aggressive and immunocomplex diseases, or immunoassociated purulent-inflammatory, nonspecific inflammatory lung diseases, cerebrovascular diseases,  in which suppression and stimulation of reactivity is a pathogenetic mechanism for normalizing homeostasis, depending on the links of the immune system, doses of antigens, the initial state of protective functions, phases of the immune response, etc. Keywords: Stimulation. Suppression. Immunodeficiency


2018 ◽  
Vol 17 (5) ◽  
pp. 325-337 ◽  
Author(s):  
Hojjat Borna ◽  
Kasim Assadoulahei ◽  
Gholamhossein Riazi ◽  
Asghar Beigi Harchegani ◽  
Alireza Shahriary

Background & Objective: Neurodegenrative diseases are among the most widespread lifethreatening disorders around the world in elderly ages. The common feature of a group of neurodegenerative disorders, called tauopathies, is an accumulation of microtubule associated protein tau inside the neurons. The exact mechanism underlying tauopathies is not well-understood but several factors such as traumatic brain injuries and genetics are considered as potential risk factors. Although tau protein is well-known for its key role in stabilizing and organization of axonal microtubule network, it bears a broad range of functions including DNA protection and participation in signaling pathways. Moreover, the flexible unfolded structure of tau facilitates modification of tau by a wide range of intracellular enzymes which in turn broadens tau function and interaction spectrum. The distinctive properties of tau protein concomitant with the crucial role of tau interaction partners in the progression of neurodegeneration suggest tau and its binding partners as potential drug targets for the treatment of neurodegenerative diseases. Conclusion: This review aims to give a detailed description of structure, functions and interactions of tau protein in order to provide insight into potential therapeutic targets for treatment of tauopathies.


2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Susan L. Brockmeier ◽  
Crystal L. Loving ◽  
Tracy L. Nicholson ◽  
Jinhong Wang ◽  
Sarah E. Peters ◽  
...  

ABSTRACT Streptococcus suis is a bacterium that is commonly carried in the respiratory tract and that is also one of the most important invasive pathogens of swine, commonly causing meningitis, arthritis, and septicemia. Due to the existence of many serotypes and a wide range of immune evasion capabilities, efficacious vaccines are not readily available. The selection of S. suis protein candidates for inclusion in a vaccine was accomplished by identifying fitness genes through a functional genomics screen and selecting conserved predicted surface-associated proteins. Five candidate proteins were selected for evaluation in a vaccine trial and administered both intranasally and intramuscularly with one of two different adjuvant formulations. Clinical protection was evaluated by subsequent intranasal challenge with virulent S. suis . While subunit vaccination with the S. suis proteins induced IgG antibodies to each individual protein and a cellular immune response to the pool of proteins and provided substantial protection from challenge with virulent S. suis , the immune response elicited and the degree of protection were dependent on the parenteral adjuvant given. Subunit vaccination induced IgG reactive against different S. suis serotypes, indicating a potential for cross protection.


Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1490
Author(s):  
Victoria Matyushenko ◽  
Irina Isakova-Sivak ◽  
Igor Kudryavtsev ◽  
Arina Goshina ◽  
Anna Chistyakova ◽  
...  

Background: New coronavirus SARS-CoV-2, a causative agent of the COVID-19 pandemic, has been circulating among humans since November 2019. Multiple studies have assessed the qualitative and quantitative characteristics of virus-specific immunity in COVID-19 convalescents, however, some aspects of the development of memory T-cell responses after natural SARS-CoV-2 infection remain uncovered. Methods: In most of published studies T-cell immunity to the new coronavirus is assessed using peptides corresponding to SARS-CoV-1 or SARS-CoV-2 T-cell epitopes, or with peptide pools covering various parts of the viral proteins. Here, we determined the level of CD4+ and CD8+ memory T-cell responses in COVID-19 convalescents by stimulating PBMCs collected 1 to 6 months after recovery with sucrose gradient-purified live SARS-CoV-2. IFNγ production by the central and effector memory helper and cytotoxic T cells was assessed by intracellular cytokine staining assay and flow cytometry. Results: Stimulation of PBMCs with live SARS-CoV-2 revealed IFNγ-producing T-helper effector memory cells with CD4+CD45RA−CCR7− phenotype, which persisted in circulation for up to 6 month after COVID-19. In contrast, SARS-CoV-2-specific IFNγ-secreting cytotoxic effector memory T cells were found at significant levels only shortly after the disease, but rapidly decreased over time. Conclusion: The stimulation of immune cells with live SARS-CoV-2 revealed a rapid decline in the pool of effector memory CD8+, but not CD4+, T cells after recovery from COVID-19. These data provide additional information on the development and persistence of cellular immune responses after natural infection, and can inform further development of T cell-based SARS-CoV-2 vaccines.


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