Biomedical subjects
Publications and source records attributed to D Bon.
The authors report a case of anuria due to bilateral ureteric obstruction by silica stones in a patient taking magnesium trisilicate for many years. A review of the literature concerning silica stones is presented. The diagnosis should be suggested by the clinical history and confirmed by stone analysis. The treatment of silica stones is not specific, but must be associated with withdrawal of the drug responsible.
On the basis of a retrospective series of 74 patients with adenocarcinoma of the prostate, the authors study the survival of these patients according to the clinical stage of the lesion when treated with cyproterone acetate. Biologically speaking, the authors have studied the evolution of the blood testosterone level, as well as of PSA and PAPs. Their conclusion is that the PSA is an excellent indicator of the efficacy of the cyproterone acetate treatment. Its fast decrease proves treatment efficacy, while a new rise indicates the resumption of evolution of the neoplastic process and must lead to change the therapeutic approach.
On the basis of 133 cases, the authors analyse the clinical features and the modalities of the treatment of vesicorenal reflux in children under age 2. The number of girls is higher than that of boys. The diagnosis is most often established between 0 and 6 months of age, with a very marked peak between 0 and 1 month. The usual warning sign is a urinary infection with fever. Pyerography is normal in every second case, and retrograde cystography is the key examination, which confirms the reflux and establishes its side and degree (bilateral reflux in 53% of cases, stage II in 48% of cases). 33 children were operated at once. Another 100 first had a medical treatment, ie. urinary antibiotics, on the basis of strict criteria that are listed here. This medical treatment has been very disappointing: 20 children were lost to follow-up and 47 had secondary surgery. When surgery is necessary, advancing plasty according to Cohen's procedure yields excellent results: 98.6% of 76 operations were successful. The authors therefore think that Cohen's procedure is widely indicated, even in children under age 2.
Monoclonal antibodies were prepared against human thyrotropin. 13 different antibodies were characterized. Ten antibodies were of the IgG1 subclass. The affinities of the antibodies were in the range 10(9)-10(11) mol-1 X l. Four of them were specific for hTSH and did not react with hLH, hFSH, hCG or alpha hCG. Four reacted with these hormones and recognized the alpha subunit of hCG. One cross-reacted only with hFSH. The remaining four antibodies recognized the holo-hTSH only, and thus were designated as anti-conformational determinants. Monoclonal antibodies reacting with different antigenic determinants on the hTSH molecule defined seven clusters. Two of them were used to develop a simplified two-site sandwich radioimmunoassay in which one monoclonal antibody was immobilized on tubes (anti-beta TSH) and another (anti-alpha) labelled with 125I. This assay was highly specific and demonstrated a sensitivity level of 0.1 microIU/ml. Two monoclonal antibodies were used in immunohistochemistry and their quality and specificity was assessed in the detection of hTSH immunoreactivity in human pituitary biological sections.
Monoclonal antibodies (MAb) to human thyrotropin (hTSH) were prepared by immunization of mice and rats according to different procedures. We have previously demonstrated that a specific antigenic region on the surface of the hTSH molecule was highly immunogenic; in order to produce specific MAb to weakly immunogenic regions of hTSH, we immunized mice and rats with a complex composed of hTSH and an anti-beta hTSH MAb 27 directed against the highly immunogenic region. Monoclonal antibodies elicited by this immunization procedure were highly specific and a high percentage was found complementary to the MAb 27 used in the immunogen. We did not search for anti-MAb 27 antibodies, however one hybridoma produced antibody that preferentially reacted with the immune complex. This antibody, called 515, is an IgG1 that binds the complex with 100-fold greater affinity than it does to the anti-beta hTSH MAb 27 alone. This enhancement was also observed with the Fab fragment of the MAb suggesting that the epitope recognized by this anti-complex MAb is displayed in a very different way when hTSH is bound to the first MAb.
Although the amino acid sequence of the alpha- and beta-subunits of glycoprotein hormones in various species has been deciphered, data on their tertiary structure are not abundant. This impedes correlation between structure and function. The availability of monoclonal antibodies to human TSH (hTSH) offers the opportunity to enumerate the antigenic determinants present on the surface of hTSH and its subunits and to examine their spatial relationships. Twenty-eight monoclonal antibodies to hTSH were obtained from several fusions, and screens carried out separately in the laboratories involved in this study. Affinities for hTSH ranged from 10(8)-10(11) M-1. Cross-reactivity with bovine TSH (bTSH), human gonadotropins (hLH, hFSH, and hCG), and the alpha- and beta-subunits of hTSH distinguished 10 groups of monoclonal antibodies (mAb) according to their main cross-reactions: 1) hTSH alpha, hLH, hFSH, and hCG; 2) hTSH alpha, bTSH, hLH, hFSH, and hCG; 3) hFSH; 4) bTSH and hFSH; 5) bTSH, hLH, and hFSH; 6) bTSH, hLH, hFSH, and hCG; 7) hTSH beta; 8) hTSH beta and bTSH; 9) hTSH beta and hFSH; and 10) hTSH beta, hLH, hFSH, and hCG. mAb were incorporated into 2-site binding assays to probe hTSH by a 28 X 28 matrix, the free alpha-subunit by a 4 X 4 matrix, and the free beta-subunit by a 18 X 18 matrix. Regarding intact hTSH, 12 different clusters of mAb were distinguished and interpreted as reflecting 12 distinct antigenic regions on the surface of the hTSH molecule. Two of them were localized on the alpha-subunit, and 6 on the beta-subunit; 4 were only expressed by the holo-hormone and, thus were designated conformational antigenic regions (alpha beta). Surface mapping of the free alpha- and beta-subunits was virtually identical to that observed with the holo-hormone. Modification of the operative conditions of mAb reacting only with holo-hTSH shows that they recognize the alpha-subunit, but not the beta-subunit of hTSH. These results indicate that 1) hTSH beta presents epitopes that are evolutionary conserved; 2) hTSH alpha presents several epitopes that are species specific and 2 that are not hormone specific; 3) dissociation of hTSH does not modify the antigenic surface expressed by both subunits when they are associated; and 4) some of the conformational determinants expressed only by holo-hTSH are more likely derived from the alpha-subunit than from the beta-subunit.
Based on a series of 388 patients with a total of 466 renal and lumbar ureteric stones (414 kidneys) treated between 1987 and 1990 by extracorporeal shock wave lithotripsy (ESWL) using the SONOLITH 3000* apparatus, the authors analyse the indications and results criteria for ESWL. The success criteria adopted excluded any residual fragment and considered patients lost to follow-up as failures. The success rate varied between 48.3% and 73.8% when residual fragments less than 5 mm were included and when drop-outs were excluded. A correlation was established between the radiographic appearance of the stone (dense, smooth, spiculated), its predominant spectrophometric nature and the results of ESWL: low density, spiculated Weddellite (WD) stones gave good results and very dense, smooth Whewellite (WW) stones gave less favourable results. The authors propose a refinement of the indications for ESWL in order to improve the results. Predominantly WW stones may be suitable for primary percutaneous nephrolithotomy.
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