scholarly journals INACTIVATION OF BACTERIAL EXOTOXINS AND ENDOTOXIN BY IRON

1960 ◽  
Vol 112 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Aaron Janoff ◽  
Benjamin W. Zweifach
Keyword(s):  
Guinea Pigs ◽  
Diphtheria Toxin ◽  
Reticuloendothelial System ◽  
Partial Recovery ◽  
Alpha Toxin ◽  
Lethal Effects ◽  
Partial Restoration ◽  
Manganese Zinc

After incubation with various agents in vitro, the lethal effects of aqueous solutions of Cl. perfringens alpha toxin, C. diphtheriae toxin, and E. coli endotoxin were tested in mice, guinea pigs, and rabbits, respectively. Iron, copper, cysteine, ascorbic acid, and versene counteracted the lethal effects of alpha toxin in mice, while magnesium, manganese, zinc, and citrate did not. Iron also counteracted the lethal effects of diphtheria toxin in guinea pigs. After incubation of endotoxin with iron, its lethal effects and tissue-necrotizing actions in rabbits were counteracted. However, the pyrogenic properties of the toxin were not affected. The solubilities of perfringens alpha toxin and diphtheria toxin were markedly reduced after incubation with detoxifying metals, and resolubilization of these toxins with chelators resulted in partial restoration of toxicity. Addition of versene to detoxified endotoxin also resulted in partial recovery of lethal effectiveness. The inactivation of bacterial toxins by iron under in vitro conditions is not specific to this metal, is a reversible process, and may be due to desolubilization, reduction, or to competition by the metal for sites on the toxin normally bound by other cations in vivo. Although no evidence is presented in this paper to support the view that there is a relationship between the inactivation of endotoxin and the storage iron in the reticuloendothelial system of shocked animals, the observation of an in vitro inactivation of endotoxin by inorganic iron warrants consideration of such a mechanism.

The effect of peptic digestion on the properties of diphtheria antitoxin

1951 ◽  
Vol 138 (893) ◽  
pp. 499-513 ◽  
Keyword(s):  
Guinea Pig ◽  
Ammonium Sulphate ◽  
Guinea Pigs ◽  
Diphtheria Toxin ◽  
Diphtheria Antitoxin ◽  
Peptic Digestion ◽  
High Level ◽  
Made In

Diphtheria antitoxin prepared in the horse and refined by peptic digestion when injected in very large doses into women in an advanced stage of pregnancy did not pass to the infant. In pregnant guinea-pigs diphtheria antitoxin (naturalserum, ex -guinea-pig) passed to the young in abundance; but, after peptic-digestion, this homologous antitoxin failed entirely to pass the placenta, the young being devoid of antitoxin at birth. The passage was not affected by the treatment of the natural serum with ammonium sulphate as used in the Gibson-Banzhaf (1910) process for the concentration of antitoxin. Diphtheria antitoxin (natural serum ex -horse) passed from pregnant guinea-pigs to their off spring in smaller amounts and much less readily than homologous antitoxin, and the quantity of antitoxin( ex -horse) so passing was reduced even further and very considerably as a result of peptic digestion. Even under the most favourable conditions homologous antitoxin takes sometime (2 or 3 days) to attain the same concentration in the young as in the mother; but once this concentration has been attained it is preserve data high level for long periods. Passive anaphylactics ensitization of guinea-pigs, either of the whole animal or the isolated uterus, is easily effected, in vivo or in vitro , by small quantities of diphtheria antitoxin (either natural serum or ammonium sulphate concentrated, ex -guinea-pig), but this property is completely lost when the homologous antitoxin is subjected to peptic digestion. It is not possible to sensitize anaphylactically guinea-pigs, in vivo or in vitro , by means of diphtheria antitoxin, ex -horse, whether the antibody is presented either in the form of natural serum, or concentrated by means of ammonium sulphate; and the result is the same when pepsin-refined diphtheria antitoxin ex -horse is used. When 5 or 10 units of diphtheria antitoxin ex -horse, whether as natural serum, ammonium-sulphate concentrated or pepsin-refined, are injected subcutaneously into guinea-pigs, the animals are rendered Schick-negative in a few hours. These antitoxins are eliminated in about a week, after which time the injected guinea-pigs are found to be Schick-positive again. If, however, the same amounts of antitoxin made in guinea-pigs are injected into guinea-pigs the result is different; the animals also become Schick-negative, but this condition is maintained for a month or longer. That is, homologous antitoxin is eliminated much more slowly; but if this natural serum antitoxin from the guinea-pig is subjected to peptic digestion it is eliminated as quickly as diphtheria antitoxin made in the horse. When diphtheria toxin is injected intracutaneously into guinea-pigs, a quantity of diphtheria antitoxin 50,000 times as large as that required to neutralize it in vitro is required for neutralization in the animal, and then only if injected intravenously within 1hr.; but little or no neutralization in vivo occurs if the intravenous injection is longer delayed, whatever type of homologous or heterologous antitoxin is administered.

Accumulation of Macromolecular Particles in the Reticuloendothelial System (RES) Mediated by Platelet Aggregation and Disaggregation

1969 ◽  
Vol 22 (03) ◽  
pp. 496-507 ◽  
Author(s):  
W.G van Aken ◽  
J Vreeken
Keyword(s):  
Platelet Aggregation ◽  
Degradation Products ◽  
Reticuloendothelial System ◽  
Caproic Acid ◽  
Carbon Particles ◽  
Carbon Clearance ◽  
Aggregation And Disaggregation ◽  
Platelet Aggregates

SummaryCarbon particles cause platelet aggregation in vitro and in vivo. Prior studies established that substances which modify thrombocyte aggregation also influence the rate at which carbon is cleared from the blood.This study was performed in order to elucidate the mechanism by which the carbon-platelet aggregates specifically accumulate in the RES.Activation of fibrinolysis by urokinase or streptokinase reduced the carbon clearance rate, probably due to generated fibrinogen degradation products (FDP). Isolated FDP decreased the carbon clearance and caused disaggregation of platelets and particles in vitro. Inhibition of fibrinolysis by epsilon-amino-caproic acid (EACA), initially accelerated the disappearance of carbon and caused particle accumulation outside the RES, predominantly in the lungs. It is supposed that platelet aggregation and locally activated fibrinolysis act together in the clearance of particles. In the normal situation the RES with its well known low fibrinolytic activity, becomes the receptor of the particles.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

scholarly journals Comparative studies on Salmonella typhi grown in vivo and in vitro III. The immunizing potencies of acetone-killed vaccines prepared from in vivo and in vitro grown bacteria and the immunizing potency of substances isolated from infected organs

1963 ◽  
Vol 61 (3) ◽  
pp. 353-363 ◽  
Author(s):  
A. L. Olitzki ◽  
Dina Godinger
Keyword(s):  
Comparative Studies ◽  
Guinea Pigs ◽  
Peritoneal Fluid ◽  
Parent Strain ◽  
Salmonella Typhi ◽  
Challenge Strain

1. Salmonella typhi, strain Ty2, grown in vivo and employed as acetone-dried vaccine possessed a higher immunizing potency than the descendants of the same parent strain grown in vitro and employed as vaccine.2. When 2 × 108in vitro-grown bacteria were employed as challenge, the immunizing effects of both types of vaccine were more marked than after administration of 2 × 108in vivo-grown bacteria as challenge.3. The higher potency of the in vivo-grown vaccine was apparent in all experiments, whether the challenge strain was grown in vivo or in vitro.4. Immunogenic substances were isolated from infected organs of mice and guinea-pigs, and an immunogenic substance from the peritoneal fluid of the infected guinea-pigs was concentrated by precipitation with ethanol.

Paradoxical effect of salbutamol in a model of acute organophosphates intoxication in guinea pigs: role of substance P release

2007 ◽  
Vol 292 (4) ◽  
pp. L915-L923 ◽  
Author(s):  
Jaime Chávez ◽  
Patricia Segura ◽  
Mario H. Vargas ◽  
José Luis Arreola ◽  
Edgar Flores-Soto ◽  
...  
Keyword(s):  
Substance P ◽  
Guinea Pigs ◽  
Smooth Muscle Contraction ◽  
In Vivo Experiments ◽  
Intracellular Ca ◽  
Neurokinin 1 ◽  
Substance P Release

Organophosphates induce bronchoobstruction in guinea pigs, and salbutamol only transiently reverses this effect, suggesting that it triggers additional obstructive mechanisms. To further explore this phenomenon, in vivo (barometric plethysmography) and in vitro (organ baths, including ACh and substance P concentration measurement by HPLC and immunoassay, respectively; intracellular Ca2+ measurement in single myocytes) experiments were performed. In in vivo experiments, parathion caused a progressive bronchoobstruction until a plateau was reached. Administration of salbutamol during this plateau decreased bronchoobstruction up to 22% in the first 5 min, but thereafter airway obstruction rose again as to reach the same intensity as before salbutamol. Aminophylline caused a sustained decrement (71%) of the parathion-induced bronchoobstruction. In in vitro studies, paraoxon produced a sustained contraction of tracheal rings, which was fully blocked by atropine but not by TTX, ω-conotoxin (CTX), or epithelium removal. During the paraoxon-induced contraction, salbutamol caused a temporary relaxation of ∼50%, followed by a partial recontraction. This paradoxical recontraction was avoided by the M2- or neurokinin-1 (NK1)-receptor antagonists (methoctramine or AF-DX 116, and L-732138, respectively), accompanied by a long-lasting relaxation. Forskolin caused full relaxation of the paraoxon response. Substance P and, to a lesser extent, ACh released from tracheal rings during 60-min incubation with paraoxon or physostigmine, respectively, were significantly increased when salbutamol was administered in the second half of this period. In myocytes, paraoxon did not produce any change in the intracellular Ca2+ basal levels. Our results suggested that: 1) organophosphates caused smooth muscle contraction by accumulation of ACh released through a TTX- and CTX-resistant mechanism; 2) during such contraction, salbutamol relaxation is functionally antagonized by the stimulation of M2 receptors; and 3) after this transient salbutamol-induced relaxation, a paradoxical contraction ensues due to the subsequent release of substance P.

In-vitro and in-vivo Evaluation of Anti-asthmatic Activity of Eugenia jambolana bark

2021 ◽  
pp. 3337-3342
Author(s):  
Bhong Prabha N. ◽  
Naikawade Nilofar. S. ◽  
Mali Pratibha. R. ◽  
Bindu Madhavi. S.
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Animal Models ◽  
Aqueous Extract ◽  
Guinea Pigs ◽  
Bark Extract ◽  
Eugenia Jambolana ◽  
In Vivo Animal Models

Objectives: The present study designed to evaluate the Antiasthmatic activity of aqueous extract of bark of Eugenia Jambolana (AEEJ) on in vitro and in vivo animal models. Materials and methods: Different in vitro and in vivo animal models was used to study the anti asthmatic activity as isolated goat tracheal chain preparation, Acetylcholine and Histamine induced bronconstriction in guinea pigs, effect of drug extract on histamine release from mast cell was checked by clonidine-induced mast cell degranulation, and milk-induced eosinophilia and leukocytosis. Results: In-vitro study on goat tracheal chain preparation revealed that aqueous extract of Eugenia jambolana (AEEJ)bark exerted antagonistic effect on the histamine induced contraction. (P<0.05) The guinea pigs when exposed to 0.2% histamine aerosol showed signs of progressive dyspnoea leading to convulsions. AEEJ significantly prolonged the latent period of convulsions (PCT) as compared to control following the exposure of histamine (0.2%) aerosol (P<0.01). The observation of present study indicates aqueous extract of Eugenia jambolana shows significant inhibition of milk induced eosinophilia and leukocytosis. Group of animals pretreated with aqueous Eugenia jambolana bark extract showed significant reduction in degranulation of mast cells when challenged with clonidine. The prevention of degranulation process by the aqueous Eugenia jambolana bark extract (P<0.01) indicates a possible stabilizing effect on the mast cells, indicating mast cell stabilizing activity. Conclusions: Thus, AEEJ showed antihistaminic, mast cell stabilizing and protective in guinea pigs against histamine induced PCD, reduced eosinophilia and leukocytosis and hence possesses potential role in the treatment of asthma.

scholarly journals The potential of microdialysis to estimate rifampicin concentrations in the lung of guinea pigs

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245922
Author(s):  
Faye Lanni ◽  
Neil Burton ◽  
Debbie Harris ◽  
Susan Fotheringham ◽  
Simon Clark ◽  
...  
Keyword(s):  
Drug Development ◽  
Guinea Pigs ◽  
Sampling Technique ◽  
Tissue Fluid ◽  
Experimental Conditions ◽  
Continuous Sampling ◽  
Drug Concentrations ◽  
The Impact

Optimised pre-clinical models are required for TB drug development to better predict the pharmacokinetics of anti-tuberculosis (anti-TB) drugs to shorten the time taken for novel drugs and combinations to be approved for clinical trial. Microdialysis can be used to measure unbound drug concentrations in awake freely moving animals in order to describe the pharmacokinetics of drugs in the organs as a continuous sampling technique. The aim of this work was to develop and optimise the microdialysis methodology in guinea pigs to better understand the pharmacokinetics of rifampicin in the lung. In vitro experiments were performed before progressing into in vivo studies because the recovery (concentration of the drug in the tissue fluid related to that in the collected dialysate) of rifampicin was dependent on a variety of experimental conditions. Mass spectrometry of the dialysate was used to determine the impact of flow rate, perfusion fluid and the molecular weight cut-off and membrane length of probes on the recovery of rifampicin at physiologically relevant concentrations. Following determination of probe efficiency and identification of a correlation between rifampicin concentrations in the lung and skeletal muscle, experiments were conducted to measure rifampicin in the sacrospinalis of guinea pigs using microdialysis. Lung concentrations of rifampicin were estimated from the rifampicin concentrations measured in the sacrospinalis. These studies suggest the potential usefulness of the microdialysis methodology to determine drug concentrations of selected anti-TB drugs to support new TB drug development.

The Effects Of Prostacyclin (PGI2) On Intravascular Platelet Aggregation

1981 ◽  
Author(s):  
G G Duncan ◽  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Platelet Count ◽  
Guinea Pigs ◽  
Adenosine Diphosphate ◽  
Before And After ◽  
Dependent Inhibition ◽  
Induced Aggregation ◽  
Dose Dependent ◽  
Anaesthetised Rats

Intravascular aggregation can be measured by counting the number of circulating platelets before and after the injection of aggregation agents. The Technicon Autocounter was modified to count platelets continuously and connected via a double cannula in a carotid artery to an anaesthetised animal.Adenosine diphosphate (ADP) and collagen gave dose- dependent falls in the circulating platelet count when injected into rats, guinea pigs and rabbits. This enabled aggregation to be accurately quantitated in vivo.The infusion of PGI2 (0.25-1 ug/kg/min) in anaesthetised rats and rabbits produced a dose-dependent inhibition of the fall in platelet count produced by ADP and collagen. The formation of PGI2 can be inhibited in vitro by 15- hydroperoxyarachidonic acid (15HPAA). When 20 ug/kg/min of 15HPAA was infused into rats, aggregation produced by collagen was significantly increased suggesting that PGI2 is continuously formed by the rat vascular endothelium. This observation was confirmed by infusing 6-keto PGF1α antiserum. This antibody also prevented the inhibitory activity of PGI2 on collagen-induced aggregation. The study of continuous platelet counting in guinea pigs has been hampered by the occurrence of thrombocytopenia in certain animals. When 2 ug/kg/min of PGI2 was infused for 10 mins, a rise in the circulating platelet count to a steady plateau 4-5 × 105 platelets occurredThese experiments have shown that PGI2 will prevent aggregation by ADP and collagen and will reverse spontaneous thrombocytopenia and that PGI2 is continuously released from the vessels of anaesthetised rats.

In vivo hepatic clearance of lipophilic drugs predicted by in vitro uptake data into cryopreserved hepatocytes suspended in sera of rats, guinea pigs, monkeys and humans

Xenobiotica ◽  
2018 ◽  
Vol 49 (8) ◽  
pp. 887-894 ◽  
Author(s):  
Takashi Koyanagi ◽  
Koji Yano ◽  
Soonih Kim ◽  
Norie Murayama ◽  
Hiroshi Yamazaki ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Hepatic Clearance ◽  
Lipophilic Drugs ◽  
Uptake Data ◽  
In Vitro Uptake

scholarly journals Cross-Reactive Effects of Vaccines: Heterologous Immunity between Tetanus and Chlamydia

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 719
Author(s):  
Marijana Stojanovic ◽  
Ivana Lukic ◽  
Emilija Marinkovic ◽  
Ana Kovacevic ◽  
Radmila Miljkovic ◽  
...  
Keyword(s):  
Immune Response ◽  
Guinea Pigs ◽  
Chlamydial Infection ◽  
Neutralization Assay ◽  
Tetanus Immunization ◽  
Guinea Pig Model ◽  
Heterologous Protection ◽  
Heterologous Effects

Vaccines can have heterologous effects on the immune system, i.e., effects other than triggering an immune response against the disease targeted by the vaccine. We investigated whether monoclonal antibodies (mAbs) specific for tetanus could cross-react with Chlamydia and confer heterologous protection against chlamydial infection. The capability of two tetanus-specific mAbs, namely mAb26 and mAb51, to prevent chlamydial infection has been assessed: (i) in vitro, by performing a neutralization assay using human conjunctival epithelial (HCjE) cells infected with Chlamydia trachomatis serovar B, and (ii) in vivo, by using a guinea pig model of Chlamydiacaviae-induced inclusion conjunctivitis. The mAb26 has been superior in comparison with mAb51 in the prevention of chlamydial infection in HCjE cells. The mAb26 has conferred ≈40% inhibition of the infection, compared to less than 5% inhibition in the presence of the mAb51. In vivo, mAb26 significantly diminished ocular pathology intensity in guinea pigs infected with C. caviae compared to either the mAb51-treated or sham-treated guinea pigs. Our data provide insights that tetanus immunization generates antibodies which induce heterologous chlamydial immunity and promote protection beyond the intended target pathogen.

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