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Biomedical subjects

C Boulard

Publications and source records attributed to C Boulard.

At least 91 records · Page 5Linked to original sources
PubMed1975

[Comparative evolution of blood antibodies in cattle infested with hypodermosis and treated with different insecticides (author's transl)].

Immunological response to hypodermosis is studied by a passive hemagglutination method in three groups of cattle naturally infested during the spring of 1972. In the autumn, one group was treated with fenthion and another with niclofolan, a drug generally used for distomatosis, but also efficient in hypodermosis and free from side-effects. The third group served as a control. Two kinds of immunological response are observed after use of the insecticide. In the group treated with fenthion, there is a rapid drop in antibodies during the 3 days following treatment; this increases for the next 2 months up to a very low level, which is stable for 3 months (fig. 3, 4, 5). During the same period, antibodies in the control group increase regularly to reach a maximum in April or May (fig. 1, 2). The immunological response of the host is closely related to the antigenic stimulation of the larvae. In the group treated with niclofolan, the slow drop in antibodies suggests that there is a parallel drop in the number of larvae during the month following treatment. A study of the other group shows that larvae are affected in the 24 hours following fenthion administration. This agent, as well as all organophosphorous compounds, are well-known to act efficiently on larvae and have anaphylactic-type side-effects on the host. The massive degradation of larvae should have induced an important antigenic reaction, but no increase in the antibodies of the host is observed; there is a even rapid drop in the number of larvae immediately after treatment. This fact is investigated further by experiments on guinea pig: the role of antigen-antibody complexes is studied by passive anaphylaxis. It appears that shock reactions, following use of organophosphorous insecticides, have a true-hyper-sensitivity origin, and are increased by the intrinsic toxicity of the first instar larvae.

Animals↗
PubMed1975

[Histological tissue study of cattly harboring the Hypoderma lineatum parasite (De Vill.) (Diptera-Oestriform) (author's transl)].

The migrating larvae of H. lineatum throughout the submucosal connective tissue of the oesophagus of cattle induce an acute inflammatory reaction. The aim of this study is to investigate histopathological tissue changes. Connective tissue damage is produced by the inflammatory reaction, but mostly by larval proteolytic enzymes. Fibrous proteins and matrix are all largely affected. Around the larvae there are 3 concentric levels of degradation. The external one is characterized by vascular response. No tissue component is destroyed, but the collagen fibers dissociate into fibrils. In the 2 internal levels (B, C) the fibrils lying along the larvae progressively degrade, splitting into large then small fragments. The elastic fibers are differently affected, but also show breaking and thinness. Finally, the matrix increases, metabhromatic reactions appear, and many mononuclear cells and granulocytes invade this injured area. Fibrin network generally present in inflammatory reaction is not found around the larvae except posteriorly in the regenerative zone. All the changes in the fibrous proteic structures of connective tissue facilitate larval migration. Repair in the larval pathway commences shortly after the passage of the larvae. Necrotic tissues are rapidly destroyed by larval enzymes and tissular and cellular enzymes, macrophages and granulocytes are abundant. The respective importance of larval enzymes and cellular enzymes in the necrotic phase is analyzed. This study, carried out between October and March, also shows an increase of inflammatory reaction and tissular degradation. The immune response of the host and the nutritional habits of the larvae are probably involved.

Animals↗
PubMed1975

[Role of ACTH in regulation of aldosterone secretion].

During the nycthemeral cycle, ACTH modulated the aldosterone production and increases plasmatic level at the end of night. The chronic stimulant effect of angiotensin II is a permissive factor of ACTH influence on aldosterone formation.

Adrenocorticotropic Hormone↗
PubMed1975

[Plasma concentrations of LH and of sex steroids during the normal menstrual cycle and during contraceptive treatment].

The authors have studied the long-term effects of combined oestrogen-progestogen on the secretion of gonadotrophins and on ovarian function. Estimation of the radio-immune levels of the plasma concentrations of the pituitary luteinizing hormone (LH), of oestradiol (E2), of progesterone (P) and of 20 alpha hydroxyprogesterone (20 alpha OHP) and of testosterone (T) served as a base for this study. A test cycle and 8 cycles in which a combination of 50 micrograms of ethinyl-oestradiol and 0.5 mg of norgestrel were administered were studied in 4 normal volunteer women. A pituitary stimulation test using 50 micrograms of gonadotrophin "releasing factor" (LH-RH) was given during the 7th cycle. Ovarian stimulation using human menopausal gonadotrophins (HMG) was given during the 8th cycle of treatment in 3 of the women and in 3 other subjects. Pituitary secretion of LH and ovarian secretion of E2 and P are partially inhibited. Pituitary response to the injection of LH-RH stays normal but 5 out 6 patients had no response to stimulation by gonadotrophins. These results allow us to conclude that the lowering of production of gonadotrophins during treatment with combination oestrogen and progestagens is responsible for inhibition of ovarian activity, and that there is a delay before the latter respond to stimulation by either endogenous or exogenous gonadotrophins.

Adult↗