Dose–response profiles for both induction and elicitation phases were evaluated with seven chemical allergens using the guinea pig maximization test. Considering the risk assessment of contact sensitization in its practical sense, the profile of elicitation would be more critical than that of induction, and it should be evaluated in a maximally induced human population or experimental animals. ...

Guinea pigs infected by intradermal injection of living toxigenic diphtheria bacilli and protected by horse antitoxic globulin, given either before or after infection, develop delayed hypersensitivity of the tuberculin type to diphtherial proteins. The highest degree of hypersensitivity is specifically directed against diphtheria toxin (or toxoid) itself, although smaller delayed skin reactions...

One feature of allergic asthma, the EAR (early allergic reaction), is not present in the commonly used mouse models. We therefore investigated the mediators involved in EAR in a guinea-pig in vivo model of allergic airway inflammation. Animals were sensitized using a single OVA (ovalbumin)/alum injection and challenged with aerosolized OVA on day 14. On day 15, airway resistance was assessed af...

Inhalation of adenosine causes bronchoconstriction in asthmatic subjects, but the effect of this purine nucleotide on airway vascular permeability is unknown. In order to determine whether adenosine produces airway microvascular leakage and, if so, to examine the effect of cromolyn (sodium cromoglycate (SCG)) on this extravasation of Evans blue was measured in the airways of ovalbumin-sensitize...

A delayed-type hypersensitivity (DTH) reaction in the course of brucellosis in humans and animals can be revealed by the brucellin INRA (Brucellergen) skin test. Brucellergen is composed of more than 20 proteins of different molecular weights. A 12-kDa protein eliciting DTH in Brucella melitensis Rev1-sensitized guinea pigs was found to be a significant component for the allergenic properties o...

Airway smooth muscle (ASM) mass appears to be increased in the bronchi of patients with chronic severe asthma. Although the precise mechanisms that induce these changes are unknown, increases in ASM mass are caused, in part, by ASM cell proliferation. After allergen challenge in rats, it has been possible to demonstrate an increase in ASM mass by morphometric techniques. To examine whether hype...

BACKGROUND Isocyanates are used in polyurethane production. Dermal exposure to isocyanates can induce contact allergy. The most common isocyanate is diphenylmethane diisocyanate used for industrial purposes. The isomer diphenylmethane-4,4'-diisocyanate (4,4'-MDI) is used in patch testing. Diphenylmethane-4,4'-diamine (4,4'-MDA) is its corresponding amine. Concurrent reactions to 4,4'-MDI and 4,...

In the present investigation, we have studied the bronchoprotective effect of ethanolic extract of Achyranthes aspera Linn. in toluene diisocyanate (TDI) induced occupational asthma in wistar rats. Wistar rats were divided into four different groups of eight animals each. All animals except control group were sensitized by the intranasal application of 10% TDI to induce airway hypersensitivity....

FEMALE GUINEA PIGS WERE SUBJECTED TO LAPAROTOMY AT DIFFERENT STAGES OF PREGNANCY, AND THEIR FETUSES INJECTED THROUGH THE UTERINE WALLS WITH ONE OF THE FOLLOWING PREPARATIONS: Old Tuberculin, tubercle bacilli of the BCG strain killed by heat or exposure to phenol, and living BCG. A large number of the animals injected in utero with Old Tuberculin failed to develop skin hypersensitivity to P.P.D....