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Biomedical subjects

D Roux

Publications and source records attributed to D Roux.

At least 145 records · Page 8Linked to original sources
PubMed1982

Monoclonal antibodies to 5'-triphospho-(2'-5')adenyladenosine oligonucleotides.

Thirteen monoclonal antibodies to ppp(A2'p5')nA oligonucleotides have been produced by fusing Y3 myeloma cells with spleen cells of rat hyperimmunized with A2'p5'A succinyl albumin as immunogen. 125I-labeled A2'p5'A succinyl tyrosine methyl ester was used as a labeled probe. Antibodies were detected by their ability to bind the labeled analog and were selected for their affinity for A2'p5'A. There were no significant differences between the properties of the monoclonal antibodies and of the antiserum. They discriminated between 2'-5' and 3'-5' phosphodiester bonds: they crossreacted poorly with (A3'p5')2A (crossreactivity ratio, greater than 10(4)) and even less with ATP an adenosine (crossreactivity ratio, greater than (6)). The affinity was high (Kd = 6 x 10(-12) M) for succinyl A2'p5'A, which is the best ligand, and also high for A2'p5'A (crossreactivity ratio, 3) and (A2'p5')2A, (A2'p5')3A, and (As'p5')4A (crossreactivity ratio, 7.5). The binding to triphosphorylated isomers, ppp(A2'p5)nA, was affected by the presence of the triphosphate groups, and the affinity increased as the length of the isomer increased (crossreactivity ratio, 10,000 for n = 1 to 200 for n = 4). Thermodynamic analysis of these data demonstrated that, in dephosphorylated isomers, the binding site of highest affinity was located at the 5'-OH end of the molecule whereas in phosphorylated isomers, the favorable binding sites were in the middle and at the 2'-OH end of the chain. Use of monoclonal antibodies of such a specificity together with the 125I-labeled 2-5A analog allows quantification of (A2'p5')nA directly and of ppp(A2'p5')nA after removal of the terminal phosphates by alkaline phosphatase treatment.

Adenine Nucleotides↗
PubMed1982

The reproducibility of results in bovine brucellosis serology and their correlation with the isolation of Brucella abortus.

In both the complement fixation test (CFT) and the serum agglutination test (SAT) titres were reproducible for the most part within a twofold range. They seldom exceeded these limits and never a fourfold range. Brucella abortus was successfully isolated in 86% of serologically positive cases and evidence is presented to confirm the use of the 30 International Units/ml level in the CFT as being diagnostically significant. The SAT, when done in microtitration plates, is even more reproducible than when done in tubes. The incidence of infected animals aborting or calving down with negative titres was found to be low.

Agglutination Tests↗
PubMed1982

Unilateral orchitis in a bull caused by Brucella abortus biotype1.

A case of Brucella orchitis in a Brahman bull is described. Positive serological titres were detected 1 month before clinical symptoms became obvious, whereas the seminal plasma only contained detectable levels of antibody after the onset of orchitis. It is concluded that serological assays on the seminal plasma alone are inadequate to detect sub-clinically infected animals, and consequently particularly bulls that are intended for use in AI centres should be subjected to a full battery of serological tests as well, before they are certified to be free of brucellosis. The pathology seen in this case was an acute, necrotic orchitis characterized by the presence of numerous granulomas containing the Brucella organisms centrally.

Animals↗
PubMed1982

Leptospira interrogans serovar pomona associated with abortion in cattle: isolation methods and laboratory animal histopathology.

Leptospira interrogans serovar pomona was successfully isolated from cattle urine in the western Transvaal after an abortion storm had occurred. Direct inoculation of EMJH medium proved the most successful method. The selective agent, 5-fluorouracil, was most effective in controlling contamination when used at the 0,4 mg/ml level. The strain isolated was pathogenic in hamsters, but specific lesions and the leptospirae were seen only where overwhelming infection occurred.

Abortion, Veterinary↗
PubMed1981

The efficacy of bacteriological procedures for the isolation of Brucella abortus from abattoir material.

A process of emulsifying and centrifuging abattoir specimens before plating out is described. Brucella abortus was isolated more successfully by this process than by conventional methods, especially in low grade infections. The 5 different media used were equally effective in our attempts at isolation, but growth did not necessarily occur on all 5 plates. In dairy cows, specimens from supra-mammary lymph nodes, udder and iliac lymph nodes accounted for a high percentage of positive isolations.

Abattoirs↗
PubMed1980

The isolation of Brucella abortus biotype I from serologically positive reactors following on S19 adult inoculation of dairy cows.

The incidence of infection following adult inoculation is such that this method alone cannot be relied on to control the spread of brucellosis. Brucella infection is present in a high percentage of serologically positive cases using the interpretation of titres as applied in South African. One premature and one full term calf born to cows 7-9 months after adult vaccination as well as the placentae, discharges and colostrum were all heavily infected with B. abortus biotype I.

Agglutination Tests↗
PubMed1977

[The diagnosis of brucellosis in cattle (author's transl)].

Tests currently in use of the diagnosis of brucellosis and the immune response in cattle following exposure to Brucella antigens are reviewed. The interpretation and evaluation of results obtained by different tests under conditions where S19 vaccine is used, are discussed. Attention is focussed on the possible role of the bull in disseminating Brucella organisms.

Animals↗
PubMed1975

[Radioimmunoassay without extraction of L-triiodothyronine in human serum].

A radio-immunoassay of L-triiodothyronin is described. Blinding of T3 to TBG is prevented by salicylate (1%--w/v). The rabbit antiserum obtained by injection of a complexe T3-bovine serum albumin is diluted between 1/10000 and 1/20000. Bound and free hormone are separated by polyethylene glycol (17%--w/v). Serum T3-concentration in normal subjects averaged 132 +/- 29 ng/dl (SD). In hyperthyroid and hypothyroid patients, these values were respectively 351 +/- 118 ng/dl and 68 +/- 21 ng/dl.

Humans↗
PubMedDate not supplied

[Baby blues: characterization and influence of psycho-social factors].

BACKGROUND: Within days following birth, most women are showing signs of mood changes, commonly named baby blues. Due to the frequency of this condition, baby blues is considered as a physiological state probably associated to biological modifications. Some studies have shown an existing link between the intensity of the baby blues and post-partum mood disorder. Therefore, it seems important to report and explore in more details the clinical background related the condition. The aim of this study was to demonstrate the possibility of a link between the intensity of the baby blues and some specific factors like maternal self-esteem, maternal childcare stress and social background, and also to define the symptoms of the baby blues from core dimensions in mood disorders. METHOD: Mothers were recruited few hours before giving birth in a teaching hospital. At the third day following birth, an appointment was made to obtain the necessary information (past medical history and social history) and history of previous mood disorders. The mood was evaluated from the scale of the intensity of baby blues from Kennerly and Gath (1989). Moreover, evaluations at day 3 and week 6 post birth of self-esteem in relation to motherhood (Maternal self-report Inventory from Shea and Tronick, 1988), stress in relation with the care of the baby (Childcare Stress Inventory from Cutrona, 1983) and the social support (Social Support scale from Bruchon-Schweitzer, 1998) were undertaken. RESULTS: 95 women were included in the final sample. The intensity of the baby blues was explained by the type of pregnancy (p=0.002), a low maternal self-esteem (p=0.025), high levels of stress in relation to the care of the baby (p=0.074). The basic clinical characteristic of the baby blues seems to be due to an increase in the emotional reaction with a sharp feelings, leading to a lability rather than an affect sad tonality. CONCLUSION: The baby blues seems to be a physiological process whereby the intensity is influenced by psychological factors. Consequently the diminution of self-esteem with motherhood and the increase of stress in relation to the care of the baby appeared to be significant factors in the intensity of the baby blues. Moreover, the clinical characteristics found in this study implies that the baby blues is more related to hypomania rather than to depression syndrome. This non-pathological state could be the first stage leading to a puerperal psychosis in predisposed women, which is mainly characterized by manic symptoms.

Adolescent↗
PubMedDate not supplied

Encapsulation of DNA in new multilamellar vesicles prepared by shearing a lyotropic lamellar phase.

Encapsulation of DNA in a new non-cationic multilamellar vector (Spherulites), composed of phosphatidylcholine, cholesterol and polyoxyethylene alcohol, is described here for the first time. Spherulites entrapping DNA were prepared by shearing a phospholipid lyotropic lamellar phase, using a recently discovered method. The average diameter of these vesicles ranges around 300 nm, and can be adjusted depending on the conditions of the process. The formulation did not result in cytotoxicity for the human cells and could be used as a DNA delivery system. More emphasis is brought to the role of condensing agents like histones on the encapsulation yield, which has been studied using radiolabelled DNA. It is shown that use of histones (histone to DNA ratio of 0.4) can increase significantly the encapsulation of DNA, thus improving the transfection efficiency. Transfection experiments were done with success using the beta-galactoside reporter gene on human primary cells (human skin fibroblasts and human bone marrow stromal cells). The results suggest that the spherulites have to be considered as a new and promising tool for gene transfection.

Adsorption↗