Effects of prednisolone on murine strongyloidiasis

Parasitology ◽  
1981 ◽  
Vol 83 (2) ◽  
pp. 401-409 ◽  
Author(s):  
D. I. Grove ◽  
H. J. S. Dawkins
Keyword(s):  
Small Intestine ◽  
Rapid Development ◽  
Acquired Resistance ◽  
Acquired Immunity ◽  
Development Of Resistance ◽  
Prednisolone Treatment ◽  
Secondary Infections ◽  
Spontaneous Expulsion ◽  
C3h Mice ◽  
Resistance To Infection

SUMMARYThe effects of prednisolone were investigated in C57B1/6 mice infected with Strongyloides ratti. In primary infections, the numbers of adult worms in the small intestine and larvae in the stools were increased and there was a slight delay in the spontaneous expulsion of worms. In secondary infections, there was an initial suppression of acquired resistance, with larvae appearing normally in the stools on the 5th day after infection. This was followed, however, by a rapid development of resistance and expulsion of worms over the next few days. Prednisolone treatment did not alter fecundity in primary or secondary infections. There was no evidence of autoinfection in control or corticosteroid-treated animals. Prednisolone abrogated innate resistance to infection in C3H mice. It is concluded that prednisolone probably facilitated infection by non-specific mechanisms as well as by suppressing specific acquired immunity.

Studies on Tyzzer's Disease: Acquired Immunity Against Infection and Activation of Infection by Immunosuppressive Treatment

1979 ◽  
Vol 13 (2) ◽  
pp. 143-148 ◽  
Author(s):  
A. Schaich Fries
Keyword(s):  
Antibody Titre ◽  
Persistent Infection ◽  
Immunosuppressive Treatment ◽  
Acquired Resistance ◽  
Serum Antibody ◽  
Challenge Infection ◽  
Acquired Immunity ◽  
Serum Antibody Titre ◽  
Resistance To Infection ◽  
Immunofluorescence Antibody

Summary The correlation between serum antibody titre and resistance to challenge infection with Bacillus piliformis was studied in naturally infected mice, in experimentally infected but recovered mice, and in mice treated with antigen prepared from infected livers. Irrespective of the way in which the antibodies were acquired resistance to infection was found to be related to the immunofluorescence antibody titre found. Experimentally infected but recovered mice, as well as rats with persistent antibodies to Bacillus piliformis, were given prednisolone in order to activate a possible persistent infection. Bacillus piliformis was detected in the rats, but not in the mice.

The protease phenotype and crystalline nature of the granules of intraepithelial mast cells in Trichinella spiralis-infected mice

1995 ◽  
Vol 53 ◽  
pp. 818-819
Author(s):  
D.S. Friend ◽  
N. Ghildyal ◽  
M.F. Gurish ◽  
K.F. Austen ◽  
R.L. Stevens
Keyword(s):  
Small Intestine ◽  
Mast Cells ◽  
Epithelial Cells ◽  
Lamina Propria ◽  
Trichinella Spiralis ◽  
Intestinal Epithelial ◽  
Carboxypeptidase A ◽  
C3h Mice ◽  
Granule Morphology ◽  
Crystalline Nature

Trichinella spiralis induces a profound mastocytosis and eosinophilia in the small intestine of the infected mouse. Mouse mast cells (MC) store in their granules various combinations of at least five chymotryptic chymases [designated mouse MC protease (mMCP) 1 to 5], two tryptic proteases designated mMCP-6 and mMCP-7 and an exopeptidase, carboxypeptidase A (mMC-CPA). Using antipeptide, protease -specific antibodies to these MC granule proteases, immunohistochemistry was done to determine the distribution, number and protease phenotype of the MCs in the small intestine and spleen 10 to >60 days after Trichinella infection of BALB/c and C3H mice. TEM was performed to evaluate the granule morphology of the MCs between intestinal epithelial cells and in the lamina propria (mucosal MCs) and in the submucosa, muscle and serosa of the intestine (submucosal MCs).As noted in the table below, the number of submucosal MCs remained constant throughout the study. In contrast, on day 14, the number of MCs in the mucosa increased ~25 fold. Increased numbers of MCs were observed between epithelial cells in the mucosal crypts, in the lamina propria and to a lesser extent, between epithelial cells of the intestinal villi.

scholarly journals Smart Nanoparticles for Chemo-Based Combinational Therapy

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 853
Author(s):  
Binita Shrestha ◽  
Lijun Wang ◽  
Eric M. Brey ◽  
Gabriela Romero Uribe ◽  
Liang Tang
Keyword(s):  
Cancer Treatment ◽  
Cancer Biology ◽  
Complex Disease ◽  
Rapid Development ◽  
Acquired Resistance ◽  
Therapeutic Index ◽  
Chemotherapeutic Agents ◽  
Combinational Therapy ◽  
Precision Therapy ◽  
External Stimuli

Cancer is a heterogeneous and complex disease. Traditional cancer therapy is associated with low therapeutic index, acquired resistance, and various adverse effects. With the increasing understanding of cancer biology and technology advancements, more strategies have been exploited to optimize the therapeutic outcomes. The rapid development and application of nanomedicine have motivated this progress. Combinational regimen, for instance, has become an indispensable approach for effective cancer treatment, including the combination of chemotherapeutic agents, chemo-energy, chemo-gene, chemo-small molecules, and chemo-immunology. Additionally, smart nanoplatforms that respond to external stimuli (such as light, temperature, ultrasound, and magnetic field), and/or to internal stimuli (such as changes in pH, enzymes, hypoxia, and redox) have been extensively investigated to improve precision therapy. Smart nanoplatforms for combinational therapy have demonstrated the potential to be the next generation cancer treatment regimen. This review aims to highlight the recent advances in smart combinational therapy.

scholarly journals Moderate levels of 5-fluorocytosine cause the emergence of high frequency resistance in cryptococci

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yun C. Chang ◽  
Ami Khanal Lamichhane ◽  
Hongyi Cai ◽  
Peter J. Walter ◽  
John E. Bennett ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
High Frequency ◽  
Antifungal Agent ◽  
Inhibitory Concentration ◽  
Glucuronic Acid ◽  
Rapid Development ◽  
Acid Synthesis ◽  
Transcriptional Factor ◽  
Development Of Resistance ◽  
Acid Accumulation

AbstractThe antifungal agent 5-fluorocytosine (5-FC) is used for the treatment of several mycoses, but is unsuitable for monotherapy due to the rapid development of resistance. Here, we show that cryptococci develop resistance to 5-FC at a high frequency when exposed to concentrations several fold above the minimal inhibitory concentration. The genomes of resistant clones contain alterations in genes relevant as well as irrelevant for 5-FC resistance, suggesting that 5-FC may be mutagenic at moderate concentrations. Mutations in FCY2 (encoding a known permease for 5-FC uptake), FCY1, FUR1, UXS1 (encoding an enzyme that converts UDP-glucuronic acid to UDP-xylose) and URA6 contribute to 5-FC resistance. The uxs1 mutants accumulate UDP-glucuronic acid, which appears to down-regulate expression of permease FCY2 and reduce cellular uptake of the drug. Additional mutations in genes known to be required for UDP-glucuronic acid synthesis (UGD1) or a transcriptional factor NRG1 suppress UDP-glucuronic acid accumulation and 5-FC resistance in the uxs1 mutants.

scholarly journals Aspiculuris tetraptera in wild Mus musculus. Age resistance and acquired immunity.

1976 ◽  
Vol 50 (3) ◽  
pp. 197-202 ◽  
Author(s):  
M. Behnke Jerzy
Keyword(s):  
Mus Musculus ◽  
Worm Burden ◽  
Acquired Resistance ◽  
Age Groups ◽  
Acquired Immunity ◽  
House Mice ◽  
Wild House Mice ◽  
The Mean ◽  
Aspiculuris Tetraptera

AbstractWild house mice, naturally infected with Aspiculuris tetraptera were segregated according to their weight into six age groups. The prevalence of infection and the mean worm burden of these mice were studied in the different age groups. The overall prevalence of infection was high (57% or more) in all the groups except the youngest. Mice acquired larvae soon after weaning; the highest larval burdens were reached in juvenile mice and the highest mature worm burdens, a group later, in mature mice. Older mice had fewer larvae and fewer mature worms. The mature worm burdens decreased but relatively slower than the larval burdens. It is suggested that either innate or acquired resistance could account for these observations.

scholarly journals TUBERCULOSIS OF RABBITS INDUCED BY DROPLET NUCLEI INFECTION

1948 ◽  
Vol 87 (6) ◽  
pp. 585-594 ◽  
Author(s):  
H. L. Ratcliffe ◽  
W. F. Wells
Keyword(s):  
Inflammatory Response ◽  
Linear Relationship ◽  
Normal Control ◽  
Acquired Resistance ◽  
Single Exposure ◽  
Initial Infection ◽  
Development Of Resistance ◽  
Droplet Nuclei ◽  
Initial Lesions

At intervals from 2 to 11 weeks after normal rabbits had inhaled small numbers of virulent bovine tubercle bacilli as separated cells in droplet nuclei, groups of these animals received a single exposure to reinfection during which each animal inhaled about 20,000 separated bacilli. Normal control rabbits which inhaled this large number of bacilli died within 4 weeks thereafter. Their deaths were attributed to destruction of the lungs by developing initial tubercles. Eleven of 12 rabbits which were reinfected within 4 weeks after initial infection seemed to respond as normal animals. Their lungs were largely replaced by developing reinfection tubercles when they died or were killed within 32 days after reinfection. The inflammatory response of the reinfection tubercles was not consistently different from that of initial tubercles, although reinfection tubercles contained fewer bacilli than initial lesions of the same age. Within 5 weeks after initial infection rabbits apparently had developed immunity to reinfection with virulent bovine tubercle bacilli inhaled as separated cells in droplet nuclei. In some of them, however, exposure to massive inhaled reinfection seemed to stimulate the progress of initial infection. It is suggested that in rabbits the development of resistance to tubercle bacilli does not bear a linear relationship to time, but progresses in steps and within 5 weeks after small initial infection by inhalation is adequate to prevent the growth of separated bacilli when these are deposited upon alveolar walls. It is suggested also that the basic effect of acquired resistance of rabbits to tubercle bacilli is inhibition of multiplication of the bacilli.

scholarly journals Mycoplasmas and Their Antibiotic Resistance: The Problems and Prospects in Controlling Infections

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 24-34 ◽  
Author(s):  
O. A. Chernova ◽  
E. S. Medvedeva ◽  
A. A. Mouzykantov ◽  
N. B. Baranova ◽  
V. M. Chernov
Keyword(s):  
Antibiotic Resistance ◽  
Molecular Basis ◽  
Rapid Development ◽  
Integrated Approach ◽  
Stress Factors ◽  
Antimicrobial Drugs ◽  
Cellular Processes ◽  
Complex Processes ◽  
Development Of Resistance ◽  
Higher Eukaryotes

The present review discusses the problem of controlling mycoplasmas (class Mollicutes), the smallest of self-replicating prokaryotes, parasites of higher eukaryotes, and main contaminants of cell cultures and vaccines. Possible mechanisms for the rapid development of resistance to antimicrobial drugs in mycoplasmas have been analyzed. Omics technologies provide new opportunities for investigating the molecular basis of bacterial adaptation to stress factors and identifying resistomes, the total of all genes and their products contributing to antibiotic resistance in microbes. The data obtained using an integrated approach with post-genomics methods show that antibiotic resistance may be caused by more complex processes than has been believed heretofore. The development of antibiotic resistance in mycoplasmas is associated with essential changes in the genome, proteome, and secretome profiles, which involve many genes and proteins related to fundamental cellular processes and virulence.

scholarly journals Analysis of CRISPR in Streptococcus mutans suggests frequent occurrence of acquired immunity against infection by M102-like bacteriophages

Microbiology ◽  
2009 ◽  
Vol 155 (6) ◽  
pp. 1966-1976 ◽  
Author(s):  
Jan R. van der Ploeg
Keyword(s):  
Streptococcus Mutans ◽  
Genome Sequence ◽  
Sequence Similarity ◽  
Amino Acid Sequences ◽  
Acquired Immunity ◽  
Environment Analysis ◽  
Loss Of Resistance ◽  
Dna Elements ◽  
Resistance To Infection ◽  
Resistant Mutants

Clustered regularly interspaced short palindromic repeats (CRISPR) consist of highly conserved direct repeats interspersed with variable spacer sequences. They can protect bacteria against invasion by foreign DNA elements. The genome sequence of Streptococcus mutans strain UA159 contains two CRISPR loci, designated CRISPR1 and CRISPR2. The aims of this study were to analyse the organization of CRISPR in further S. mutans strains and to investigate the importance of CRISPR in acquired immunity to M102-like phages. The sequences of CRISPR1 and CRISPR2 arrays were determined for 29 S. mutans strains from different persons. More than half of the CRISPR1 spacers and about 35 % of the CRISPR2 spacers showed sequence similarity with the genome sequence of M102, a virulent siphophage specific for S. mutans. Although only a few spacers matched the phage sequence completely, most of the mismatches had no effect on the amino acid sequences of the phage-encoded proteins. The results suggest that S. mutans is often attacked by M102-like bacteriophages, and that its acquisition of novel phage-derived CRISPR sequences goes along with the presence of S. mutans phages in the environment. Analysis of CRISPR1 of M102-resistant mutants of S. mutans OMZ 381 showed that some of them had acquired novel spacers, and the sequences of all but one of these matched the phage M102 genome sequence. This suggests that the acquisition of the spacers contributed to the resistance against phage infection. However, since not all resistant mutants had new spacers, and since the removal of the CRISPR1 array in one of the mutants and in wild-type strains did not lead to loss of resistance to infection by M102, the acquisition of resistance must be based on further elements as well.

The dynamics of the host-parasite relationship

Parasitology ◽  
1969 ◽  
Vol 59 (3) ◽  
pp. 497-503 ◽  
Author(s):  
A. D. Donald ◽  
J. K. Dineen ◽  
D. B. Adams
Keyword(s):  
Single Dose ◽  
Worm Burden ◽  
Residual Effect ◽  
Challenge Infection ◽  
Single Infection ◽  
Development Of Resistance ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Resistance To Infection ◽  
Host Parasite

An experiment has been conducted to examine the effects of discontinuous infection with H. contortus in sheep on the development of resistance to infection. When sheep were given four doses of 3000 larvae at fortnightly intervals and these sensitizing infections were removed on day 56, there was no evidence of resistance at that time nor of any residual effect of the sensitizing infections on the response to challenge at day 140. When, however, the sensitizing infections were permitted to persist until day 132, there was strong resistance to the establishment of a challenge infection whether or not the sensitizing worm burden was removed prior to challenge, and, in the case of superimposed challenge, resistance was coupled with rejection of most of the sensitizing population. When a single infection with 3000 larvae was followed 22 days later with a further single dose of 3000 larvae, there was no evidence of resistance whether or not the first infection was removed with anthelmintic. If the interval between two doses of 3000 larvae was extended to 76 days there was resistance to the establishment of the second dose if this was superimposed on the first, but not if the first infection was removed 8 days prior to the second dose.It is suggested that the manifestations of resistance appear in a sequence of (i) resistance only to a superimposed infection, followed by (ii) resistance to a challenge infection in the presence or absence of a previously existing worm burden, coupled in the former case with rejection of much of the existing population. This sequence could be related crudely to a product of larval dose and time. Although larval dose and time were to some extent confounded in the design of the experiment strong resistance was associated with prolonged uninterrupted infection.

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