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Biomedical subjects

N Gualde

Publications and source records attributed to N Gualde.

86 records · Page 5Linked to original sources

[Clinical effects of the transfusion of leukocytes isolated by filtration from continuous flux].

The present work studies clinical effects of leukocyte transfusions to patients with medular aplasis. Leukocytes were collected by filtration on a continuous flow, according to the technique earlier described in this review [9]. Two major points are stressed on tolerance by the patients of the injected products and clinical efficiency. Seventy eight suspensions were prepared and transfused to 30 patients in the course of 36 incidents of myeloid insufficiency. All patients but two evidenced by the time of transfusion a number of polynuclears inferior to 500 per cubic millimeter. The infection was quite serious with increased gravity despite the antibiotherapy. Intolerance was noticeable in about one third of the cases, half of which consisted only in chillis by the end or after transfusion. Only one accident consisting in acute respiration troubles and shock was observed. This however does not occur by chance. It involves sensitization which may be related to HLA system but may also be of different nature, although not clearly identified. Nevertheless is efficiency of the injected products demonstrated by recirculation of the transfused leukocytes. This was noticed within an hour following transfusion for more than 50 percent of the cases. Furthermore it lasted for 16 hours in more than one fourth of the patients. In addition following results are in favour of real clinical efficiency. Certainly in the course of 16 aplasic incidents, no improvement was observed. For most patients however transfusions were late and not renewed or the patients were highly immunized. Conversely the infection state did improve in 8 patients, the disease responsible for aplasia running its course on its own. Lastly in the course of 12 aplasic incidents, infection and acute aplasia did cure. All these observations should lead one to study with great care the immunological state of the recipient. Instructions being known, the number of transfused leukocytes should be sufficient and renewals frequent enough. Under these conditions leukocyte (filtered and eluted) transfusions appear safe and reliable.

Adolescent↗

HL-A and silicosis.

The search for a link between HL-A antigens and silicosis among 75 patients revealed no significant association. However, we did note a decrease in the frequency of B7; This change could be linked to a greater sensitivity to silicosis among persons who carry this antigen. There was also an increase of B8 among those silicotic patients with tuberculosis, although only a small number of patients were affected.

HLA Antigens↗

[Relationship between maternal HL-A immunization and familial prognosis of haemolytic disease of the newborn due to Rh incompatibility].

The purpose of this work is to study the possible relationships between Rh and HLA foeto maternal immunizations and to evaluate the clinical implications of HLA antibodies in children with hemolytic disease of the newborn. 74 families including 246 children were investigated. These were divided into 3 groups on the basis of increasing severity of the hemolytic disease. HLA antibodies, with usually well defined specificity, were found in 32,43% of Rh immunized women. This incidence is analogous to that found in Rh non-immunized mothers. HLA immunization did not appear, through the present investigation, to influence the clinical course of the Rh hemolytic disease.

Antibody Specificity↗

Effect of arachidonic acid metabolites on thymocyte proliferation.

The influences of prostaglandin E2 (PGE2), 15-hydroxyeicosatetraenoic acid (15-HETE) and leukotrienes (LT) on the proliferative response of mature (PNA-) and immature (PNA+) mouse thymocytes was investigated. Both PNA+ and PNA- thymocytes proliferated when cultured with concanavalin A plus interleukin-2. PGE2 in concentrations of 10(-6) to 10(-9) M caused significant inhibition of proliferation of both PNA+ and PNA- thymocytes in these cultures. In contrast, the lipoxygenase products 15-HETE, LTB4, LTC4 and LTD4 caused marked increases in proliferation of PNA+ thymocytes while having no effect on PNA- cells. Therefore, the effect of leukotrienes on thymocyte proliferation depends upon the level of cell maturation and mainly affects immature PNA+ thymocytes.

Animals↗

Dendritic cells produce eicosanoids, which modulate generation and functions of antigen-presenting cells.

Eicosanoids have been shown to be potent immunoregulatory arachidonic acid (AA) metabolites. AA is the precursor of prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)) which are able to modulate both inflammation and the immune response. Dendritic cells process and present antigens to T lymphocytes. They are highly specialized antigen-presenting cells (APC) and usually considered as 'professional APC'. In the present paper, we report some data on the biosynthetic capacity of murine APC from the bone marrow (BM-DCs) to produce AA metabolites. Using an ELISA we have observed that BM-DCs spontaneously produce both PGE(2) and LTB(4) whose production increased in response to bacterial lipopolysaccharides (LPS). In addition we found that LTB(4) production was twice as high when both COX pathways were blocked with selective COX-inhibitors. We have also investigated the effect of PGE(2) and LTB(4) on the in vitro generation of the so-called BM-DCs. Exogenous PGE(2) and LTB(4) added to bone marrow cultures inhibit and promote, respectively, BM-DC generation. PGE(2) added to the maturing BM-DCs reduces their MHC class-II expression.

Animals↗

[Approaches to the immunological problems of leukocyte transfusions].

51 leukocyte transfusions from healthy donors and 3 from chronic myelogenous leukemia were given to 16 patients with acute leukemia and 4 with aplasia. During 14 transfusions we have observed clinicals reactions which are of immunological origin. The part of the transfusions and of the pregnancies in the presence of antibodies is argued. The necessity of utilisation of HL-A compatible donors during leukocyte transfusions is asserted.

Blood Donors↗

Purification and characterization of monoclonal antibodies to alpha-linolenic acid.

The covalently linked antigenic complex, bovine serum albumin-alpha-linolenic acid, was used to immunize Balb/c mice against the hapten. Hybridization between splenocytes and the myeloma cell line, P 3 X63 Ag 8,651, resulted in stable clones synthesizing monoclonal antibodies (Mab) that were subsequently purified and characterized. Four Mab (A, B, C, D) were retained and their specificities studied by ELISA. Antibody D only recognized 18-carbon fatty acids having a cis,cis,-cis-1,4,7 unsaturated system in the omega-3 position: it was specific for alpha-linolenic acid. B recognized all fatty acids containing the structure cis,cis,cis-1,4,7-octatriene. A and C recognized polyunsaturated fatty acids with a degree of unsaturation superior to two double bonds.

Animals↗

[Skin fibrosis in hyperthyroidism treated by sotalol and radioactive iodine (author's transl)].

The authors present detailed data about skin fibrosis appearing in hyperthyroidism treated by Sotalol and radioactive iodine. Cutaneous thickening is discovered quite rapidly when the patient is monitored daily (as in case 4). It is asymptomatic and no other features of scleroderma are found. Regression occurs within 4-10 months. Histologically, fibrosis is located in the entire dermis. Dermal appendages are normal and no inflammatory changes occur. No anomalies of collagen structure and fibroblasts have been observed ultrastructurally. Immunological studies (direct immunofluorescence of the skin, lymphocyte transformation and leucocyte migration tests with Sotalol) were normal. The mechanism is unknown, but an immunological or a toxic one is excluded; however a pharmacological action is possible. The role of other betablockers must be assessed by a randomised study.

Epidermis↗