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Biomedical subjects

J De Boever

Publications and source records attributed to J De Boever.

At least 37 records · Page 2Linked to original sources
PubMed1986

Direct chemiluminescence immunoassay for estradiol in serum.

In this simple, reliable, fast solid-phase chemiluminescence immunoassay for directly measuring (i.e., without prior extraction) estradiol-17 beta in serum, a monoclonal antibody is used that binds estradiol with high affinity (Ka = 10(10) L/mol), and does not bind other steroids tested, the highest cross reactivity observed being 0.1% for estradiol-17 alpha. In this system the monoclonal antibody is bound to the wells of microtiter plates via a second antibody directed against the monoclonal antibody. Fifty microliters of serum and estradiol-displacing agents are added, followed by 100 pg of estradiol-isoluminol conjugate, and the label is measured by luminometry after the binding reaction. The sensitivity of the assay is 180 pmol per liter of serum, and the effective working range at less than or equal to 10% CV is 270 to 6700 pmol/L. Analytical recovery of added estradiol averaged 99.7% (SD 6.5%). Within- and between-assay CVs ranged between 5 and 12.7%. Thirty-five unknown serum samples can be assayed within 4 h. Results correlated well with those obtained with a direct RIA: r = 0.94 (n = 149). This assay opens new perspectives for chemiluminescence immunoassays.

Antibodies, Anti-Idiotypic↗
PubMed1986

Direct solid-phase chemiluminescence immunoassay for salivary progesterone.

A simple, direct chemiluminescence immunoassay for progesterone in mixed, unstimulated saliva is described. We use purified polyclonal anti-progesterone antibodies covalently coupled to polyacrylamide beads and progesterone-11 alpha-hemisuccinyl-aminobutylethyl isoluminol as the chemiluminescent ligand marker. Bound and free ligand are separated by simple centrifugation. The detection limit of the assay is 1.5 pg per tube (38 pmol/L). Intra- and interassay coefficients of variation for low, medium, and high progesterone concentrations are 7.9, 6.8, 8.8% and 9.3, 6.9, 8.5%, respectively. Analytical recovery of added progesterone is 99.6%. Mean +/- SD progesterone concentrations (pmol/L) in saliva are 178 +/- 46 in the follicular phase, 313 +/- 90 in the periovulatory phase, and 658 +/- 166 in the luteal phase of the menstrual cycle. Correlation between progesterone concentrations in serum (assayed by RIA after extraction) and in saliva is good (r = 0.88, p less than 0.001, n = 96). The assay is simple, fast (4 h, including 1.5 h of incubation time), and reliable.

Adolescent↗
PubMed1985

The width of the attached gingiva during orthodontic treatment: a clinical study in human patients.

Studies of the influence of orthodontic movement on the width of the attached gingiva gave conflicting results. Therefore, it was decided to evaluate this parameter in human patients during a full orthodontic movement with fixed appliances. Retrusion of six maxillary anterior teeth was performed in thirteen patients scheduled in a prophylactic program that included a 2-week recall during the entire experiment. Before and after treatment the plaque index, the sulcus bleeding index, the width of the keratinized and the attached gingiva, and the marginal gingiva mobility index were measured. The results indicated that retrusion of the maxillary anterior teeth had no influence on any of the measured parameters.

Adolescent↗
PubMed1984

Structures and concentrations of fifteen different steroid sulfates in human breast cyst fluids.

By applying capillary gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS), a simultaneous quantitation of all important steroid sulfates present in a number of breast cyst fluids, has been obtained. The fact that prevailing androgen sulfate structures in the cyst fluids are different from those in blood suggests at least intracystic metabolism of blood-born precursors. Particularly greater amounts of 5 alpha-reduced steroids are found in breast cysts. 5 alpha-Androstane-3 alpha,17 beta-diol is a major androgen sulfate of breast cyst fluids, its concentration being some 2000-fold that of blood. After prolonged topical application of progesterone on the breast, an accumulation of the sulfates of several pregnanediol isomers could be observed.

Adult↗
PubMed1984

Ovulation stigma and concentration of progesterone and estradiol in peritoneal fluid: relation with fertility and endometriosis.

The relationship between the presence or absence of an ovulation stigma and (1) the fertility status, (2) the incidence of endometriosis, (3) the concentration of progesterone and estradiol in the peritoneal fluid, and (4) the blood levels of luteinizing hormone, follicle-stimulating hormone, progesterone, and estradiol in 21 fertile and 45 infertile patients who underwent a laparoscopy in the early (n = 48) or late luteal phase (n = 18) was investigated. An ovulation stigma was observed in about half of the patients, irrespective of their fertility status (past and subsequent), the presence of endometriosis, or the time of the luteal phase. Progesterone and estradiol concentrations in the peritoneal fluid were highest in the early luteal phase, but they were not correlated with the presence or absence of an ovulation stigma. No significant differences were observed in peripheral hormone levels between women with and those without an ovulation stigma nor between women with high or low concentrations of progesterone in the peritoneal fluid. From the data, it is concluded that hormone assays are of no aid in the diagnosis of the luteinized unruptured follicle syndrome and that the absence of an ovulation stigma on laparoscopic examination cannot be equated with the luteinized unruptured follicle syndrome.

Adult↗
PubMed1984

Solid-phase chemiluminescence immunoassay for progesterone in unextracted serum.

We describe a simple, solid-phase chemiluminescence immunoassay for progesterone in 10 microL of unextracted serum ("direct" assay). Danazol at pH 8.0 is included (100 ng per tube) to displace progesterone from binding proteins in serum. A progesterone-11 alpha-hemisuccinyl-aminobutylethyl isoluminol conjugate serves as the chemiluminescent ligand marker and homologous antiprogesterone IgG covalently coupled to "Immunobeads" is the immunoadsorbant. After the binding reaction, bound and free ligand are separated by centrifugation and the chemiluminescence yield of the bound label is determined. The sensitivity, specificity, precision, and accuracy of the method are similar to those of a conventional radioimmunoassay for progesterone in which a radioligand of tritiated progesterone and serum extraction are used. Progesterone values obtained by this procedure agreed well (r = 0.987) with those obtained by radioimmunoassay. We conclude that the chemiluminescence immunoassay for progesterone in unextracted serum is analytically valid and offers a convenient alternative to radioimmunoassay.

Binding, Competitive↗
PubMed1983

Clinical and histological characteristics of lyophilized allogenic dura mater in periodontal bony defects in humans.

This clinical and histological study investigated the use of lyophilized, allogenic dura mater (Lyodura) as a periodontal implant material in interdental bony defects (2-wall lesions) in humans. For 23 defects in 8 subjects a modified Widman flap was raised, curettage performed and the defects bridged with the implant. The same procedure, without Lyodura implantation, was performed on 23 contralateral teeth. By a standardized method, involving the use of a removable stent, the following clinical measurements were recorded after 24 and 48 weeks: the probing attachment level, the probing bone level, the probing pocket depth and the labial and interdental gingival recession. For the histological study 5 additional, interdental craters and 5 control defects were treated as in the clinical study. They were block-sectioned after 1, 2, 6, 12 and 24 weeks and processed in the usual manner for routine examination by light and polarization microscopy. From the clinical study it could be concluded that, in absolute values, only the experimental side showed a significant gain in probing attachment level and a greater reduction of the probing pocket depth. In percentage values the labial gingival recession was significantly lower and the bone formation significantly more pronounced on the experimental side. The histological examination showed that the implant remodelled completely without rejection phenomena. It was replaced gradually, after enzymatic breakdown, by the host's own collagen through the action of invading fibroblasts. Bone formation occurred along but never in the implant. The implant material seems to act as a barrier against epithelial downgrowth and infiltration of inflammatory cells.

Adult↗
PubMed1983

Solid-phase chemiluminescence immunoassay for plasma estradiol-17 beta during gonadotropin therapy compared with two radioimmunoassays.

Estradiol in plasma was determined with a simple solid-phase immunoassay based on chemiluminescence in patients undergoing ovulation induction. In the assay, we use a purified monoclonal antibody to estradiol-17 beta, with estradiol-6-carboxymethyl oxime-aminobutylethyl isoluminol as the chemiluminescent marker. The antibody is covalently coupled to polymer beads. Bound and free ligand are separated by simple centrifugation. Values so determined were compared with those determined with two different radioimmunoassay (RIA) methods, one involving the same monoclonal solid-phase antibody plus iodinated estradiol, 125I-RIA, the other a polyclonal antibody and tritiated estradiol, 3H-RIA. In the latter RIA, dextran-coated charcoal was used to separate bound and free ligand. Values determined by the three methods agreed well: for chemiluminescence vs 125I-RIA, r = 0.93; for chemiluminescence vs 3H-RIA, r = 0.94; for 125I-RIA vs 3H-RIA, r = 0.94. The three methods are similar in sensitivity, specificity, and precision. The present method is simple and reliable, taking advantage of the specificity and sensitivity intrinsic to the use of an antibody without the inconveniences associated with use of an isotopically labeled ligand.

Antibodies, Monoclonal↗
PubMed1982

[Clinical, histological and scanning electron microscopy evaluation of the Prophy-Jet in vivo and in vitro].

Clinical, histologic and scanning electron microscopic study of the use of the Prophy-Jet. The Prophy-Jet (Cavitron-International) is used for the removal of gross stain and heavy plaque. In this study the plaque and stain removal capacities have been investigated in patients with a healthy and inflamed gingiva. The influence of the spray of cleaning powder (sodiumbicarbonate) on the gingiva has been studied in gingival biopsies of Beagle dog. With the use of a scanning electron microscope the dentine and cementum have been investigated after spraying during 30 seconds to 2 minutes. The clinical results show that the plaque and the stain are removed easily and significantly except for the deep interproximal regions where the handpiece tip cannot be used in a correct angulation to the tooth surface. All patients showed gingival desquamation which could last up to 3 days. After treatment several patients suffered from aphthous ulcers. The gingiva of the Prophy-Jet treated areas in the Beagle dog showed severe epithelial desquamation, even of the papillary connective tissue, which in certain areas, can lead to necrosis. A spray lasting for 30 seconds removed approximately 10 micrograms of dentine or cementum. From these results it can be concluded that the negative aspects of the use of the Prophy-Jet are very important. It should therefore be used with caution.

Animals↗
PubMed1982

[Radiography in parodontology using the long-cone parallel technic: justification, technological principles and practical application].

Radiographs are an important aid in the periodontal examination and diagnosis. Since they are only the two-dimensional situation, it is important to use a technique that gives the best images. The long-cone paralleling technique meets the highest standards of image-quality. Geometric factors have an important influence on the dimensions and on the proportions of the different structures, especially the crown and the root length, the bone-height. Due to the greater distance between the radiation source and the film, the amount of radiation energy has to be increased. This is partly realised by an increased kilovoltage and milli-amperage. This increase also improves the contrast and the sharpness of the image. The focus-diameter, the film-thickness and the movements during the exposition-time are potential sources of blurring. However, the increased distance between the radiation source and the film reduces considerably the influence of these factors, so that the blurring is nearly invisible. Extra-oral radiographs, as orthopantomographs, are valuable as a first general image. Intra-oral long-cone radiographs are however essential if detailed images are required. The long-cone paralleling technique is based on the following principles: an increased distance between the radiation source and the film to obtain a bundle of parallel rays; an increased distance (except for the lower molar region) between the tooth and the film to obtain parallelism between the film and the long-axis of the tooth; the central beam must be directed perpendicularly to the long-axis of the tooth. If these simple principles are respected, the long-cone paralleling technique becomes a highly reliable method, although easy and fast to realise.

Humans↗