Search PubMed⌕ Search

Biomedical subjects

B Hell

Publications and source records attributed to B Hell.

At least 37 records · Page 2Linked to original sources
PubMed1994

Microsurgical and prosthetic reconstruction of patient with recurrent ameloblastoma extending into the skull base.

A patient with recurrent ameloblastoma extending into the skull base is presented. An interdisciplinary treatment strategy is described, which included proper diagnosis by computed tomography (CT) and magnetic resonance imaging (MRI) scans and radical resection of the tumor in cooperation with the neurosurgeon, followed by reconstruction with microsurgical methods, and prosthetic rehabilitation based on an implant-supported epithesis.

Ameloblastoma↗
PubMed1993

Three-dimensional ultrasonography in maxillofacial surgery. A new diagnostic tool.

Three-dimensional (3-D) ultrasonography is introduced as a new diagnostic method for soft-tissue lesions. This method is based on the production of absolutely parallel brightness (B)-scan tomographies with constant intervals. After adequate preparation, the sonographic primaries are processed into 3-D graphs by a specialized program called EUCLID-IS. This method promises to be useful in the evaluation of tumor patients as well as in the follow-up examination of these patients. The main advantages of the presented method are the capacity to measure accurately the volume of regions of interest and the excellent visualization of the structures examined.

Adult↗
PubMed1992

Lectin specificity and binding characteristics of human C-reactive protein.

C-reactive protein (CRP) is thought to play an important role in immunomodulation. The exact biologic function of this pentraxin protein is, however, still unclear. Here we report experiments designed to further characterize the binding properties of CRP. Using purified human CRP it could be shown that CRP immobilized onto polystyrene surfaces or onto latex beads binds distinct plasma glycoproteins including IgG, asialofetuin, asialo-beta 2-glycoprotein I and, likewise, synthetic glycoproteins as a lectin, exhibiting binding specificity for terminal galactosyl residues of the glycoprotein glycans. Binding of CRP to IgA, IgM, IgG, asialofetuin, asialo-beta 2-glycoprotein I and to synthetic glycoproteins requires immobilization onto surfaces of both CRP and the ligand. Fibronectin and fibrinogen are bound by surface-immobilized CRP also in soluble phase. Comparing various mono-, di-, and trisaccharides as competitive inhibitors of the lectin binding activity of CRP, only beta-D-Gal-(1-3)-D-GalNAc, beta-D-Gal-(1-4)-D-GalNAc, and beta-D-Gal-(1-4)-beta-D-Gal-(1-4)-D-GlcNAc had significant inhibitory power at a concentration of 8 mmol/liter. Binding activity of CRP was pH-dependent with an optimum at pH 5 to 6 and was reduced by 90% when pH was shifted from 6 to the physiologic pH value of 7.4. CRP exhibited lectin-like properties with binding specificity for galactosyl residues also when bound to K-562 erythroleukemia cells. It is therefore suggested that CRP immobilized onto surfaces exhibits lectin activity toward galactosyl groups preferentially in a mildly acidic environment as present at sites of inflammation.

Blood Proteins↗
PubMed1991

Experience with AO reconstruction plates after partial mandibular resection involving its continuity.

A report is presented on experience with the use of 54 plates, without primary bone grafts, after resections for malignant tumours involving the continuity of the mandible, in 52 patients. There were complications in 27 cases: postoperative infection or soft tissue dehiscence occurred 20 times, chronic soft tissue perforation once, screw loosening twice, and plate fracture four times. Adjuvant radiotherapy and/or chemotherapy had no effect on the incidence of the complications. Seventeen of the plates (a good 30%) had to be removed prematurely due to the complications. Major deformity did not always occur if relative stabilization had developed through cicatrix formation. Thirty-seven plates (barely 70%) remained: in 19 cases until the death of the patient, in 3 cases until recurrence, in 12 cases until bone grafting, and in 3 cases they were still in situ up to 65 months. In principle, reconstruction plates have proven themselves. However, application and soft tissue coverage need great care and a great deal of experience.

Bone Plates↗
PubMed1989

B-scan sonography in maxillo-facial surgery.

Ultrasonography is a relatively new diagnostic aid in maxillo-facial surgery. The method is useful in examining tumours, swellings, cysts and similar processes in the soft tissues of the cervico-facial region. Some examples are given, and some details of the technique are outlined. The ultrasound examination may easily be repeated as often as necessary.

Adult↗
PubMed1989

Developmental changes in the glycosylation and binding properties of human fibronectins. Characterization of the glycan structures and ligand binding of human fibronectins from adult plasma, cord blood and amniotic fluid.

Fibronectins from human adult plasma, fetal plasma and from amniotic fluid obtained during early and late gestation were compared with respect to (i) their reactivity with lectins, (ii) their binding to the physiological ligands gelatin and heparin, and (iii) the role of the carbohydrate residues in the binding to these two ligands. The two fibronectin isoforms displayed distinct developmental differences in both glycosylation and binding properties: (i) Proportions of tri/tetraantennary complex glycans compared to the fraction of biantennary structures, as inferred from the reactivity with concanavalin A, were highest in amniotic fluid fibronectin from late pregnancy, lower in amniotic fluid fibronectin from early gestation, and even lower in fetal and adult plasma fibronectins. Likewise, fucose (alpha 1-6) linked to the innermost N-acetylglucosamine of the chitobiosyl core, defined by reactivity with Lens culinaris agglutinin (LCA), was present primarily in amniotic fluid fibronectin, and decreased in content during gestation from the 2nd. to the 3rd. trimenon. Both fetal and adult plasma fibronectins were only weakly reactive with LCA, indicating a low content of (alpha 1-6) linked fucose residues. After prior treatment with sialidase, both plasma and amniotic fluid fibronectins strongly reacted with erythrocyte phytohaemagglutinin (E-PHA), indicating that both fibronectin isoforms contain bisecting (beta 1-4) N-acetylglucosamine residues. Amniotic fluid fibronectins showed much greater reactivity than adult and fetal plasma fibronectins with wheat germ agglutinin; binding of this lectin to amnion fluid fibronectins was not decreased by desialylation indicating the presence of poly(N-acetyllactosamine) units. Whereas amniotic fluid fibronectins were strongly reactive with peanut agglutinin, neither adult nor fetal plasma fibronectins did bind to this lectin unless after prior desialylation. Hence, both fibronectin isoforms contain O-glycan residues that are fully sialylated in fetal and adult plasma fibronectins, but only partly sialylated in amniotic fluid fibronectins. According to these differences, glycosylation of plasma and amniotic fluid fibronectins is under developmental regulation. (ii) Amniotic fluid fibronectins had a significantly lower binding activity for both heparin and gelatin than plasma fibronectins. Moreover, amnion fibronectin from late gestation displayed a significantly lower binding to these two ligands than amnion fibronectin from early gestation. Fetal plasma fibronectins had a lower binding activity for gelatin than adult plasma fibronectin. (iii) Treatment of fibronectins with sialidase, fucosidase and removal of N-glycans with endoglycosidases H and F did not affect binding to gelatin and heparin, indicating that the interaction of plasma and amnion fibronectin with these two ligands is not influenced by their oligosaccharide moieties.

Adult↗
PubMed1988

Lower lip carcinoma. Infiltration of the mandible along the mental nerve.

In general, carcinoma of the lower lip has a good prognosis after radical surgery. In rare cases, however, recurrences may be seen because of spread of the tumour along the mental nerve into the mandible. The earliest symptom of this is pain in the mandible and radiological evidence of widening of the mental foramen. Large resections and reconstructive procedures will be necessary. Three cases are presented.

Aged↗
PubMed1988

Demonstration of glycosylation variants of human fibrinogen, using the new technique of glycoprotein lectin immunosorbent assay (GLIA).

A new highly sensitive method, incorporation the ELISA technique (enzyme-linked immunosorbent assay), is described for the quantitation of the glycan residues of glycoproteins. With the aid of this "glycoprotein-lectin immunosorbent assay (GLIA)", it is possible to determine the nature of the glycan residues of a single protein in a glycoprotein mixture, without prior purification. The GLIA can be used for the accurate determination of the inhibitor constant for the interaction of any monosaccharide with any lectin. Using the described technique, glycosylation of human fibrinogen from plasma and amniotic fluid were compared. In fibrinogen from amniotic fluid a "fetal" glycosylation type could be demonstrated. In addition, evidence is presented for the first time that plasma fibrinogen possesses (GlcNAc beta 1----4Man beta) residues (bisecting GlcNAc) and O-glycosidically bound carbohydrate units. Preliminary results were published as abstract (E. Köttgen et al. (1988) Fresenius Z. Anal. Chem. 330, 448).

Enzyme-Linked Immunosorbent Assay↗
PubMed1986

Functional analysis of plasma fibronectin with special consideration of binding interferences.

So far, soluble fibronectin has been quantitated mostly by immunological techniques. In this investigation we show that an immunological assay provides reliable results only with intact fibronectin. Fibronectin fragments resulting from proteolysis give rise to falsely raised values. We present four functional tests based on the sandwich (ELISA) technique on microtitre plates. These quantify fibronectin on the basis of its binding capacity to collagen, heparin, fibrin and carboxy-group-modified IgG with high sensitivity, specificity and precision. Analysis of the bioactivity spectrum of intact fibronectin is not disturbed by fibronectin fragments. Furthermore we demonstrate interferences, in particular between heparin and collagen in their mutual binding to fibronectin. This provides new indications of a "substrate activation" of fibronectin.

Buffers↗