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Biomedical subjects

A de Weck

Publications and source records attributed to A de Weck.

16 recordsLinked to original sources
PubMed2002

Allergic pulmonary and ocular tissue responses in the absence of serum IgE antibodies (IgE) in an allergic dog model.

Allergen-specific serum IgE may be insensitive as a marker for IgE-mediated reactions at the mucosal level. Five of six atopic beagle dogs developed high ovalbumin (OVA)-specific serum IgE levels after sensitization. This study aimed to show that these dogs still express allergen-specific IgE at the pulmonary and ocular mucosal levels and in the skin even when corresponding serum IgE was below the detection limit. When serum IgE levels were negative, all dogs exhibited allergic reactions at the tissue level. Specifically, they displayed positive ocular reactions after an ocular OVA challenge. After airway challenge with aerosolized OVA, five out of six animals reacted with decreased compliance and increased resistance of the lungs. Furthermore, an eosinophilia in the bronchoalveolar lavage fluid (BALF) was observed. Four weeks after the last exposure to OVA, IgE-positive BALF cells were seen in all animals. Six weeks on, all dogs still displayed positive skin reactions to OVA. This indicates that not only skin testing but also detection of ocular and pulmonary allergic tissue reactions including cell-bound IgE in BALF can serve as more sensitive and lasting surrogate markers of hypersensitivity in the allergic dog model than detection of allergen-specific serum IgE levels.

Animals↗
PubMed2000

[Allergies, an increasing public health problem: causes and consequences].

Allergies due to IgE immunoglobulins and belonging to the atopic syndrome, such as asthma, allergic rhinitis and atopic eczema have increased in prevalence three times during the past 20-30 years in most industrialized countries. The causes of that increase are still much debated but seem to be related to multiple changes in the environment. Our recent studies on dog atopy indicate that the interaction of a dominant gene responsible for high IgE production but with variable expression, according to several environmental factors acting during infancy, could explain observations made in man. Allergic diseases have become an important portion of public health costs, amounting to approximately 200 billions French Francs in the European Community. Early and adequate care for the about 20% of allergic patients which are severely affected, as well setting up a systematic prevention policy would have a moderating influence on the increasing costs, and would achieve improvements in the quality of life of allergic patients. Appropriate measures include fostering medical and political awareness about the problem's urgency, the formation of an appropriate body of specialists and an Allergological education at all levels, as well as the definition of a screening and care providing policy taking in account existing medical structures.

Allergens↗
PubMed1986

Schistosome-derived inhibitory factor: an immunosuppressive agent preferentially active on T lymphocytes.

We have previously shown that schistosome-derived inhibitory factors (SDIF) inhibited lymphocyte proliferation and induced immunosuppression. Crude SDIF was purified by successive gel filtration and reverse-phase high-performance liquid chromatography. Purified SDIF preparations strongly inhibited the proliferation of different T cell line cells, while other cell lines (B cells, macrophages and fibroblasts) were almost not affected by SDIF. The inhibition of T cell proliferation by SDIF was not mediated through an Interleukin-2-dependent mechanism since both Interleukin-2-dependent and -independent T cells were inhibited. SDIF-activity was absorbed by cells in a time- and cell-number-dependent fashion at 4 degrees C, suggesting the existence of a possible receptor for SDIF. However, the difference in sensitivity to SDIF proliferation inhibition could not be attributed to the presence or absence of this receptor since cells from SDIF-sensitive and SDIF-resistant cell lines absorbed SDIF activity in the same way.

Absorption↗
PubMed1984

Radiosensitive suppressor T cells for LIF production in mixed lymphocyte reactions.

LIF activity in the supernatants of one way MLR, one MNC population being irradiated, was significantly increased as compared to that produced in two way MLR. Puromycin treatment of the irradiated cells decreased LIF response while puromycin treatment of the non-irradiated cells had no detectable effect. A similar increase of LIF activity was achieved by removing either OKT8+ or OKT4+ cells from one cell component before performing the mixed culture. Recombination of the depleted cell samples followed by MLR decreased LIF response except when belonging to allogeneic donors. Mostly, irradiation of OKT8 depleted mononuclear cells before recombination with OKT4 depleted cells prevented LIF suppression in MLR. The suppressor function of OKT4+ cells seems to be more radiosensitive than that of OKT8+ cells in this system. It is suggested that LIF production in MLR is regulated by a suppressor circuit which is histocompatible restricted and requires interaction of both OKT4+ and OKT8+ cells.

Antibodies, Monoclonal↗
PubMed1981

[Accumulation of eosinophils in the nasal secretion in patients with bronchial asthma].

From October 1977 to September 1979 69 out of 500 asthmatic patients were selected in whom case histories, skin tests and IgE blood-levels formed a sub-group with more or less pure allergic asthma and a sub-group with more or less pure intrinsic asthma. All the patients exhibited a large quantity of granulocytes in the bronchial and nasal secretions. Special attention was paid to the contents of eosinophils in the nasal smear and in the bronchial mucus. The intrinsic subgroup had a (non significantly) greater incidence of 100% eosinophils in the bronchial secretion than the allergic sub-group (p less than 0.1). Unexpectedly, the reverse was found in the nasal secretions: only 33% of the intrinsics (9 cases) and as many as 67% of the allergics (28 cases) exhibited 100% eosinophils in the nasal mucus (p less than 0.025). Thus, when discussing the two forms of asthma, allergic and intrinsic, it is always necessary to bear in mind the possible paradoxical behaviour between nasal and bronchial mucus: pure eosinophilia in the lower respiratory tract may often be found concomitantly with pure neutrophilia in the upper respiratory tract, when some of the criteria for intrinsic asthma are fulfilled.

Asthma↗
PubMed1977

[The CEA test and other immunological tests as disease course controls in gastrointestinal adenocarcinoma].

161 patients with adenocarcinoma of the gastrointestinal tract were studied to determine the value of the CEA test and a battery of non-specific immunological tests during the course of the disease. The ability of these tests to detect a tumor recurrence in radically operated patients was evaluated. A false negative preoperative CEA value was found in 40% of the patients with gastric carcinoma and 32% with colorectal carcinoma. Patients with a negative preoperative CEA value, and those with only slightly elevated values, had a distinctly better prognosis regarding initial operability and tendency to postoperative recurrence than patients with primarily markedly elevated values. With few exceptions, the development of distant metastases was detected earlier and more easily with the CEA test than by the usual routine follow-up methods. However, in the event of isolated local recurrence the CEA test was positive in only 1 of 5 patients. This reflects the direct correlation between tumor size and CEA elevation. The CEA test is a valuable supplement in the follow-up of patients with gastrointestinal carcinoma.

Adenocarcinoma↗
PubMed1976

The effect of Leishmania tropica on stimulation of lymphocytes with phytohaemagglutinin.

Cell-mediated immune (CMI) responses are important in the immunity against leishmanial infections. However, infection persists in the presence of CMI for unknown reasons. Evidence is presented that L. tropica and its products are capable of inhibition of the stimulation of lymphocytes by PHA. This inhibition is dose dependent, and not dependent on competition for nutrients in the medium, nor on neutralization of PHA. The inhibition is observed on the lymphocytes of species susceptible to leishmanial infection, and not operative in resistant species. The mechanisms of the lymphocyte suppression are discussed.

Animals↗