L'IMMUNITÉ DANS LES INFECTIONS STAPHYLOCOCCIQUES : 1. ACTION DE L'ANTITOXINE CONTRE UNE INFECTION BACTÉRIENNE EXPÉRIMENTALE

1956 ◽  
Vol 2 (3) ◽  
pp. 271-280 ◽  
Author(s):  
A. Frappier ◽  
S. Sonea
Keyword(s):  
Experimental Infection ◽  
Marked Decrease ◽  
Appreciable Effect ◽  
Significant Protection ◽  
Infection Bactérienne ◽  
First Time ◽  
Lethal Doses ◽  
Living Bacteria ◽  
At Will

Using the intracerebral route in mice immunized with commercial antitoxin, complete or significant protection was obtained for the first time at will against lethal doses of living staphylococci. The protection was effective against the five staphylococcus strains used. The mechanism of this experimental infection was partially studied in normal and in immunized mice by counting at variable intervals the living bacteria at the inoculation point (brain) and in the blood. A moderate bacteraemia was present immediately after the inoculation, decreased later to few bacteria per drop of blood, and eventually disappeared. This bacteraemia was not influenced by the presence of the antitoxin. At the inoculation point, a marked decrease in the number of staphylococci was evident immediately after the injection of the bacteria, and one hour later. The antitoxin had no appreciable effect on this phenomenon. The local multiplication following the above mentioned decrease in the number of staphylococci was moderate and was not checked by the antitoxin. Mortality in unprotected animals seems to be caused by staphylococcal toxins liberated in greater quantity by the increased number of living staphylococci found about the fourth hour after inoculation.

Professional pathology in the production of aluminum in the Kola Arctic

2020 ◽  
pp. 767-767
Author(s):  
S. A. Syurin ◽  
S. A. Gorbanev
Keyword(s):  
Working Conditions ◽  
Occupational Diseases ◽  
Scientific Explanation ◽  
Marked Decrease ◽  
The Arctic ◽  
Aluminium Production ◽  
First Time

In 2007-2017, 22 occupational diseases were diagnosed for the first time in 18 workers engaged in aluminium production in the Arctic. A marked decrease in occupational morbidity in 2010-2017 was found, which was not associated with changes in working conditions and therefore requires an appropriate scientific explanation.

scholarly journals Recognition Pattern of the Fasciola hepatica Excretome/Secretome during the Course of an Experimental Infection in Sheep by 2D Immunoproteomics

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 725
Author(s):  
David Becerro-Recio ◽  
Javier González-Miguel ◽  
Alberto Ucero ◽  
Javier Sotillo ◽  
Álvaro Martínez-Moreno ◽  
...  
Keyword(s):  
Experimental Infection ◽  
Fasciola Hepatica ◽  
Cathepsin L ◽  
Helminth Parasites ◽  
Glutathione S Transferase ◽  
Serum Samples ◽  
Secretory Products ◽  
Immunogenic Proteins ◽  
Host Parasite ◽  
First Time

Excretory/secretory products released by helminth parasites have been widely studied for their diagnostic utility, immunomodulatory properties, as well as for their use as vaccines. Due to their location at the host/parasite interface, the characterization of parasite secretions is important to unravel the molecular interactions governing the relationships between helminth parasites and their hosts. In this study, the excretory/secretory products from adult worms of the trematode Fasciola hepatica (FhES) were employed in a combination of two-dimensional electrophoresis, immunoblot and mass spectrometry, to analyze the immune response elicited in sheep during the course of an experimental infection. Ten different immunogenic proteins from FhES recognized by serum samples from infected sheep at 4, 8, and/or 12 weeks post-infection were identified. Among these, different isoforms of cathepsin L and B, peroxiredoxin, calmodulin, or glutathione S-transferase were recognized from the beginning to the end of the experimental infection, suggesting their potential role as immunomodulatory antigens. Furthermore, four FhES proteins (C2H2-type domain-containing protein, ferritin, superoxide dismutase, and globin-3) were identified for the first time as non-immunogenic proteins. These results may help to further understand host/parasite relationships in fasciolosis, and to identify potential diagnostic molecules and drug target candidates of F. hepatica.

scholarly journals Whip-LAMP: a novel LAMP assay for the detection of Trichuris muris-derived DNA in stool and urine samples in a murine experimental infection model

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Pedro Fernández-Soto ◽  
Carlos Fernández-Medina ◽  
Susana Cruz-Fernández ◽  
Beatriz Crego-Vicente ◽  
Begoña Febrer-Sendra ◽  
...  
Keyword(s):  
Molecular Diagnosis ◽  
Experimental Infection ◽  
Lamp Assay ◽  
Diagnostic Methods ◽  
Urine Samples ◽  
Infection Model ◽  
Trichuris Muris ◽  
Stool Samples ◽  
First Time ◽  
Experimental Infection Model

Abstract Background Trichuris trichiura (human whipworm) infects an estimated 477 million individuals worldwide. In addition to T. trichiura, other Trichuris species can cause an uncommon zoonosis and a number of human cases have been reported. The diagnosis of trichuriasis has relied traditionally on microscopy. Recently, there is an effort to use molecular diagnostic methods, mainly qPCR. LAMP technology could be an alternative for qPCR especially in low-income endemic areas. Trichuris muris, the causative agent of trichuriasis in mice, is of great importance as a model for human trichuriasis. Here, we evaluate the diagnostic utility of a new LAMP assay in an active experimental mouse trichuriasis in parallel with parasitological method by using stool and, for the first time, urine samples. Methods Stool and urine samples were collected from mice infected with eggs of T. muris. The dynamics of infection was determined by counting the number of eggs per gram of faeces. A LAMP based on the 18S rRNA gene from T. muris was designed. Sensitivity and specificity of LAMP was tested and compared with PCR. Stool and urine samples were analysed by both LAMP and PCR techniques. Results Trichuris muris eggs were detected for the first time in faeces 35 days post-infection. LAMP resulted specific and no cross-reactions were found when using 18 DNA samples from different parasites. The detection limit of the LAMP assay was 2 pg of T. muris DNA. When testing stool samples by LAMP we obtained positive results on day 35 p.i. and urine samples showed amplification results on day 20 p.i., i.e. 15 days before the onset of T. muris eggs in faeces. Conclusions To the best of our knowledge, we report, for the first time, a novel LAMP assay (Whip-LAMP) for sensitive detection of T. muris DNA in both stool and urine samples in a well-established mice experimental infection model. Considering the advantages of urine in molecular diagnosis in comparison to stool samples, should make us consider the possibility of starting the use urine specimens in molecular diagnosis and for field-based studies of human trichuriasis where possible. Further studies with clinical samples are still needed.

Effects of endotoxin on renal function and hemodynamics

1963 ◽  
Vol 205 (2) ◽  
pp. 293-297 ◽  
Author(s):  
Jay Y. Gillenwater ◽  
Elmo S. Dooley ◽  
Edward D. Frohlich
Keyword(s):  
Blood Flow ◽  
Renal Function ◽  
Arterial Pressure ◽  
Marked Decrease ◽  
Hemodynamic Effect ◽  
Vascular Effects ◽  
Renal Vasoconstriction ◽  
Renal Functions ◽  
Principal Effect ◽  
Lethal Doses

The injection of lethal doses of Salmonella typhosa endotoxin in the dog produced an initial (18 sec) transient vasoconstriction followed by a secondary intense vasoconstriction within 5–10 min. Renal arterial pressure remained elevated for 30 min. Since local infusion of phentolamine blocked the secondary renal vasoconstriction it is suggested that the persistent vasoconstriction was due to catecholamine release during the systemic hypotension. After endotoxin injection there was a marked decrease in all renal functions. The hemodynamic effect was eliminated in one kidney by infusing phentolamine locally and holding renal blood flow constant in one group of animals thus enabling comparison of this kidney with the contralateral undisturbed kidney. In the kidney in which vascular effects were eliminated there was no alteration in renal functions after systemic or local endotoxin injection. These data, therefore, show that the principal effect of endotoxin on the kidney is hemodynamic and not nephrotoxic.

scholarly journals Ultrastructural study of degradation of calcium phosphate ceramic by human monocytes and modulation of this activity by HILDA/LIF cytokine.

1996 ◽  
Vol 44 (10) ◽  
pp. 1131-1140 ◽  
Author(s):  
M D Benahmed ◽  
D Heymann ◽  
M Berreur ◽  
M Cottrel ◽  
A Godard ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Culture Medium ◽  
Marked Decrease ◽  
Calcium Phosphate Ceramic ◽  
Multinuclear Cells ◽  
Residual Bodies ◽  
First Time

Biodegradation of ceramics in vivo is achieved essentially by monocytes and multinuclear cells (osteoclasts). Monocytes are the key element in this process because they intervene first at the biomaterial implantation site during inflammatory reaction. In this work, in vitro studies were conducted on an ultrastructural scale to determine the specific behavior of these cells with regard to a calcium phosphate (CaP) ceramic. Two types of phagocytosis were observed when cells came into contact with the biomaterial: either CaP crystals were taken up alone and then dissolved in the cytoplasm after disappearance of the phagosome membrane or they were incorporated together with large quantities of culture medium, in which case dissolution occurred after the formation of heterophagosomes. Phagocytosis of CaP coincided with autophagy and the accumulation of residual bodies in the cells. Addition of HILDA/LIF factor to these cultures induced a very marked decrease in phagocytotic activity directed at the capture of CaP crystals and culture medium. Autophagy was reduced, and residual bodies were rare or absent. This study specifies the role of monocytes in CaP biodegradation and demonstrates for the first time that HILDA/LIF has a biological effect on this cell line.

Iron as a replacement for mucin in the establishment of meningococcal infection in mice

1976 ◽  
Vol 22 (6) ◽  
pp. 832-838 ◽  
Author(s):  
G. A. Calver ◽  
C. P. Kenny ◽  
G. Lavergne
Keyword(s):  
Neisseria Meningitidis ◽  
Experimental Infection ◽  
Ferrous Sulphate ◽  
Gastric Mucin ◽  
Meningococcal Infection ◽  
Iron Dextran ◽  
Iron Compounds ◽  
Fatal Infection ◽  
Lethal Doses

Experimental infection of mice with Neisseria meningitidis was established by the injection of the bacteria suspended in solutions of various iron compounds. The progressive and fatal infection caused by otherwise non-lethal doses of organisms was produced in these mice after prior injection with ferrous sulphate or concomitant injection with iron sorbitol citrate or iron dextran. Reduction in LD50 to levels at least comparable to those obtained in the mucin challenge system was achieved; in some serogroups of N. meningitidis the LD50 was decreased more than a million fold. The results suggest that iron, which is a component of hog gastric mucin, is a factor involved in the establishment of meningococcal infection in mice. Use of iron compounds as injection medium offers a more advantageous system than mucin, since controlled administration of chemically defined substances occurs.

scholarly journals Rapid Onset of Ulcerative Typhlocolitis in B6.129P2-IL10tm1Cgn (IL-10−/−) Mice Infected with Helicobacter trogontum Is Associated with Decreased Colonization by Altered Schaedler's Flora

2006 ◽  
Vol 74 (12) ◽  
pp. 6615-6623 ◽  
Author(s):  
M. T. Whary ◽  
S. J. Danon ◽  
Y. Feng ◽  
Z. Ge ◽  
N. Sundina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quantitative Pcr ◽  
Body Condition ◽  
Experimental Infection ◽  
Clinical Signs ◽  
Interleukin 10 ◽  
Rapid Onset ◽  
Lower Bowel ◽  
Severe Diarrhea ◽  
First Time

ABSTRACT Infection with Helicobacter trogontum, a urease-positive helicobacter isolated from subclinically infected rats, was evaluated in B6.129P2-IL10 tm1Cgn (interleukin-10−/− [IL-10−/−]) and C57BL/6 (B6) mice. In a first experiment, IL-10−/− mice naturally infected with Helicobacter rodentium had subclinical typhlocolitis but developed severe diarrhea and loss of body condition with erosive to ulcerative typhlocolitis within 1 to 3 weeks of experimental infection with H. trogontum. A second experiment demonstrated that helicobacter-free IL-10−/− mice dosed with H. trogontum also developed severe clinical signs and typhlocolitis within 2 to 4 weeks, whereas B6 mice colonized with H. trogontum were resistant to disease. In a third experiment, using helicobacter-free IL-10−/− mice, dosing with H. trogontum resulted in acute morbidity and typhlocolitis within 8 days. Acute typhlocolitis was accompanied by signs of sepsis supported by degenerative hemograms and recovery of Escherichia coli and Proteus spp. from the livers of infected mice. Quantitative PCR data revealed that H. rodentium and H. trogontum may compete for colonization of the lower bowel, as H. trogontum established higher colonization levels in the absence of H. rodentium (P < 0.003). H. trogontum-induced typhlocolitis was also associated with a significant decrease in the levels of colonization by five of eight anaerobes that comprise altered Schaedler's flora (P < 0.002). These results demonstrate for the first time that H. rodentium infection in IL-10−/− mice causes subclinical typhlocolitis and that infection with H. trogontum (with or without H. rodentium) induces a rapid-onset, erosive to ulcerative typhlocolitis which impacts the normal anaerobic flora of the colon and increases the risk of sepsis.

Evaluating H2O2 in Living Bacteria by Ratiometric Fluorescent Probe

2022 ◽  
Vol 905 ◽  
pp. 210-217
Author(s):  
Qian Qian Chen
Keyword(s):  
Fluorescent Probe ◽  
Living Cells ◽  
Gram Negative Bacteria ◽  
Signal Molecule ◽  
Gram Negative ◽  
Key Factor ◽  
Live Bacteria ◽  
First Time ◽  
Living Bacteria ◽  
Ratiometric Fluorescent Probe

Hydrogen peroxide (H2O2) is a significant signal molecule in physiological and pathological processes. Levels of H2O2 in bacteria are proved to be a key factor in immune response. To sum up, detection of H2O2 levels in living bacteria is remarkable for further study of its physiological and pathological effects. Herein, we propose a novel ratiometric fluorescent probe (Nahp) to detect H2O2 in living cells and bacteria. In addition, based on boronate, Nahp has satisfactory selectivity and sensitivity toward H2O2 (LOD = 0.158 μM). Furthermore, with excellent detection performance to H2O2, Nahp is successfully used for fluorescent bioimaging of H2O2 and measuring H2O2 accumulation in bacteria. Most importantly, the probe was also used to image H2O2 in three Gram-negative bacteria, clearly revealing for the first time significant differences in H2O2 expression levels in live bacteria.

The Energy Dependence of Ion Damage in A1xGa1−xAs/GaAs HETErostructures and The Effects of Implanted Impurity

1991 ◽  
Vol 235 ◽  
Author(s):  
A. G. Cullis ◽  
D. C. Jacobson ◽  
A. Polman ◽  
P. W. Smith ◽  
J. M. Poate ◽  
...  
Keyword(s):  
Gaas Layer ◽  
Local Concentration ◽  
Significant Protection ◽  
Damage Resistance ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Layer Structures ◽  
Ion Damage ◽  
Lattice Damage ◽  
First Time

ABSTRACTBombardment damage produced by Si+ ions in AlxGa1−xAs/GaAs layer structures has been studied using transmission electron microscopy and ion channeling and backscattering spectrometry. The damage resistance of A1xGa1−xAs alloy layers increases with Al concentration. In particular, by comparison of complementary Si+ ion doses yielding similar nuclear displacement densities at 150keV and 2MeV bombardment energies, it is demonstrated for the first time that the local concentration of implanted Si impurity is likely to be a significant factor in controlling lattice damage build-up, especially for the highest Si+ ion implantation doses. It is also shown that, in a manner analogous to A1As, the alloy layers can confer a significant protection from ion damage upon adjacent, epitaxially-bonded narrow zones of crystalline GaAs.

scholarly journals The role of histidine residues in glutamate dehydrogenase

1972 ◽  
Vol 129 (2) ◽  
pp. 419-425 ◽  
Author(s):  
N. Tudball ◽  
R. Bailey-Wood ◽  
P. Thomas
Keyword(s):  
Enzyme Activity ◽  
Glutamate Dehydrogenase ◽  
Rose Bengal ◽  
Marked Decrease ◽  
Total Loss ◽  
Appreciable Effect ◽  
Normal Response ◽  
Original Activity ◽  
Histidine Residues

1. Glutamate dehydrogenase was subject to rapid inactivation when irradiated in the presence of Rose Bengal or incubated in the presence of ethoxyformic anhydride. 2. Inactivation in the presence of Rose Bengal led to the photo-oxidation of four histidine residues. Oxidation of three histidine residues had little effect on enzyme activity, but oxidation of the fourth residue led to the almost total loss of activity. 3. Acylation of glutamate dehydrogenase with ethoxyformic anhydride at pH6.1 led to the modification of three histidine residues with a corresponding loss of half the original activity. Acylation at pH7.5 led to the modification of two histidine residues and a total loss of enzyme activity. 4. One of the histidine residues undergoing reaction at pH6.1 also undergoes reaction at pH7.5. 5. The presence of either glutamate or NAD+in the reaction mixtures at pH6.1 had no appreciable effect. At pH7.5 glutamate caused a marked decrease in both the degree of alkylation and degree of inactivation. NAD+had no effect on the degree of inactivation at pH7.5 but did modify the extent of acylation. 6. The normal response of the enzyme towards ADP was unaffected by acylation at pH6.1 or 7.5. 7. The normal response of the enzyme towards GTP was altered by treatment at both pH6.1 and 7.5.

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