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Biomedical subjects

B F Pontz

Publications and source records attributed to B F Pontz.

At least 37 records · Page 2Linked to original sources
PubMed1989

[Cu deficiency as a cause of spontaneous fracture in a premature infant].

We report on a male preterm infant of 25th week of gestation, who developed a spontaneous fracture of the right femur at an age of four months. Besides an "impressed" fracture radiologically a generalized osteopenia of the skeleton and cupped metaphysis alterations were observed. An alimentary copper deficiency could be diagnosed. Additionally clinical signs were repeated apneic episodes, anaemia, neutropenia and a low serum level of both coeruloplasmin and copper. We substituted the patient orally with CuCl2 (1.2 mumol/kg/KG/d) over a period of four months resulting in a complete healing of the fracture and an improvement of the other clinical symptoms and laboratory alterations.

Bone Diseases, Metabolic↗
PubMed1988

Prenatal diagnosis of galactosialidosis.

The second prenatal diagnosis of galactosialidosis is reported. Neuraminidase and beta-galactosidase activities in cultured amniotic cells were deficient, this being confirmed by skin fibroblast enzyme assay on the affected fetus after interruption of the pregnancy. Cultured placental cells demonstrated the same enzyme deficiencies. Analysis of deproteinized amniotic fluid showed the presence of abnormal oligosaccharides specific for alpha-neuraminidase deficiency.

Amniotic Fluid↗
PubMed1988

Mucopolysaccharidosis type IIIC (Sanfilippo): early clinical presentation in a large Turkish pedigree.

Two sisters from a large consanguineous Turkish family with Sanfilippo C disease presented within the first 2 years of life. They had coarse facial features, organomegaly and discrete radiological signs of dysostosis multiplex. Urinary glycosaminoglycan excretion was elevated, heparan sulfate being the major component. The uptake of radioactive sulfate into fibroblasts from both patients was abnormal. A deficiency of acetylCoA: alpha-glucosamine transferase was demonstrated in fibroblasts from one patient. To our knowledge, this is the first report of the disease presenting in early infancy.

Acetyltransferases↗
PubMed1988

[Clinical picture and course of children with CHARGE association].

Four children are described who presented malformations according to CHARGE-Association. The primary abnormalities were choanal atresia and/or Coloboma. All four cases exhibited esophageal malformations: atresia and/or fistulas. At autopsy, three children showed arhinencephaly which is rarely observed in patients with CHARGE-Association. Patients with the main features of CHARGE-Association have a very poor prognosis depending on the severity of the malformations.

Abnormalities, Multiple↗
PubMed1987

Clinical heterogeneity in infantile galactosialidosis.

A new case of infantile galactosialidosis is presented. The condition was diagnosed when the patient was 4 months of age and she died at 20 months. She exhibited some of the symptoms of classical infantile galactosialidosis but no corneal clouding, cherry-red macular spot or limitation of joint mobility. Sonographic examination showed large kidneys and thickened cardiac septa, two symptoms as yet undescribed in this disorder. Urinary oligosaccharide analysis gave grossly pathological results and subsequent fibroblast enzyme analysis showed a deficiency of alpha-neuraminidase and beta-galactosidase. The patient's clinical features are compared with the few cases so far described in the literature.

Female↗
PubMed1986

Biochemical, morphological and immunological findings in a patient with a cutis laxa-associated inborn disorder (De Barsy syndrome).

Clinical symptoms of a male infant are described and compared with cases now classified as the De Barsy syndrome, a distinct disorder related to cutis laxa. Morphologically, elastic fibres in skin were frayed and reduced in number and density. The collagen fibril network was normal. Biochemical studies on collagen metabolism in a skin specimen and in cultured skin fibroblasts showed a normal amino acid content and a normal electrophoretic pattern of collagen constituents. The chemotactic migration of cultured fibroblasts was diminished when compared with fibroblasts from donors of different age groups. Immunological investigations revealed an imparied granulocyte function.

Chemotaxis↗
PubMed1986

Heterogeneity of osteogenesis imperfecta. Biochemical and morphological findings in a case of type III according to Sillence.

A male infant with pale-blue sclerae, who died at the age of 6 weeks through the aspiration of food, presented multiple fractures and deformation of the long tubular bones. The clinical and radiological findings and the course indicated osteogenesis imperfecta, type III, according to Sillence's classification. The family history was unremarkable. Light and electron microscopic studies of iliac crest bone obtained postmortem, showed an abrupt interruption of endochondral ossification, with an active periosteal ossification. In the region of the fractures, a mixed desmochondral callus was seen. The endoplasmic reticulum of the osteoblasts was markedly dilated, the mitochondria were swollen. The osteoid was reduced in quantity. A postmortem analysis of the collagen types I, II and III obtained from skin, cartilage and bone yielded chromatographically normal collagen constituents. An analysis of the amino acids of the collagen alpha-chains showed an increased hydroxylysine content. The radiological findings and the clinical course both indicated type III osteogenesis imperfecta: identical biochemical findings have been described only for type II. The morphological and biochemical findings described here may be a manifestation of a variable expressivity of type III osteogenesis imperfecta. On the other hand, heterogeneity of type II osteogenesis imperfecta cannot be ruled out.

Amino Acids↗
PubMed1985

SV40 transformed fibroblasts recognize the same 140 kD fibronectin chemotactic fragment as non-transformed cells.

SV40-virus-transformed human embryonal fibroblasts show an enhanced chemotactic response to the glycoprotein fibronectin. However, they recognize the same chemotactic active region as non-transformed fibroblasts. The result suggests that an enhancement of chemotaxis by fibroblasts which have been transformed with Simian Virus 40 is due not to the utilization of further chemotactic domains in the molecule, but to an increased sensitivity of the cells to the chemoattractant.

Cell Transformation, Viral↗
PubMed1984

Enhanced chemotaxis of tumor-derived and virus-transformed cells to fibronectin and fibroblast-conditioned medium.

SV40 transformants of human embryo fibroblasts showed an enhanced chemotactic response to fibronectin and conditioned medium of fibroblasts in comparison to the non-transformed cells. An even higher chemotactic response was characteristic for a malignant human fibrosarcoma cell line, whereas cells derived from low-grade malignant dermatofibrosarcoma showed a normal response in the Boyden chamber assay. The high stimulation of chemotaxis is paralleled by a reduced synthesis and an altered deposition of fibronectin in the pericellular matrix of these cells. Both high chemotactic response and lack of deposition of fibronectin may play a role in tissue invasion and formation of metastasis by malignant tumors.

Cell Transformation, Viral↗
PubMed1984

Pattern of collagen synthesis and chemotactic response of fibroblasts derived from mucopolysaccharidosis patients.

For comparative studies on the migratory potential we screened fibroblast strains derived from mucopolysaccharidosis (MPS) patients regarding their differential response to chemotactic stimuli and analysed their production of extracellular matrix components. Indirect immunofluorescence staining of MPS-fibroblasts showed the same distribution of type I and type III collagen and of fibronectin as in controls. Biochemical quantification of type I and type III collagen demonstrated an unaltered ratio of these collagen types, although the total amount of newly synthesized collagens was slightly reduced in fibroblasts from MPS patients. Whereas the synthesis of major extracellular matrix components was close to normal, the response of the MPS cells to chemotactic stimuli was greatly affected. Chemotactic migration was improved when fibroblasts were pretreated with medium conditioned by normal fibroblasts, although they never reached normal levels.

Cells, Cultured↗
PubMed1984

[Osteogenesis imperfecta: contribution to pathobiochemistry].

Osteogenesis imperfecta (OI) is a hereditary disease characterized by increased bone fragility and marked skeletal deformities. As a generalized connective tissue disorder, many patients present with other typical symptoms, such as blue sclerae, dentinogenesis imperfecta, impaired hearing, joint laxity, and easy bruising of the skin. According to clinical and genetic characteristics, Sillence classified four different groups. Metabolic alterations of connective tissue components are thought to be responsible for the pathogenesis of OI. Collagen, the main constituent of connective tissue, was analyzed in autoptic tissue and/or skin fibroblasts from patients with OI. In fibroblast culture of patients with OI group I, the range of synthesized collagen type III is elevated to 15-48% (normal up to 15%). Patients in groups II and III show an increased presence of hydroxylysine in alpha-chains of collagen types I and III. The hydroxylation of lysyl residues of the cartilage specific collagen type II is slightly elevated. In both groups, the hydroxypyroline content in all tested collagen types was normal. In our investigation, the collagen of patients with OI group IV appeared normal. Although the clinical features of patients with OI of all groups were not homogeneous, OI group III and some subtypes of group II had similar clinical courses and biochemical findings. In addition, there are patients with OI who present with clinical symptoms, but who cannot be classified into any of the known groups. For a better differentiation, biochemical examination of collagen should be performed complementary to clinical and genetic criteria.

Adolescent↗
PubMed1983

Localization of the chemotactic domain in fibronectin.

Fragments derived from human plasma fibronectin by enzymatic degradation were tested in the Boyden chamber for chemotactic activity towards various fibroblast strains. The results provide clear evidence that the chemotactic activity is restricted to a defined region of the fibronectin molecule which is the same for various fibroblast strains. The active domain is localized between the collagen binding site and the major heparin binding site, about 170 kDa apart from the N-terminal and about 70 kDa from the C-terminal ends of the two subunit peptide chains.

Binding Sites↗
PubMed1983

A study on fibroblast chemotaxis using fibronectin and conditioned medium as chemoattractants.

Chemotaxis of human embryo fibroblasts and rhabdomyosarcoma cells was studied in a blind well Boyden chamber using fibronectin as a chemoattractant. The cell strains studied show a differential response to fibronectin, a fact which may mirror the origin of the cells, that means normal skin or tumor associated tissue, respectively. Furthermore, we detected another chemoattractive fraction synthesized and secreted by fibroblasts in addition to fibronectin and collagen derived fragments. Initial experiments demonstrated the proteinous nature of the component(s) and provided some information on the biochemical features.

Cells, Cultured↗
PubMed1982

(+)-Cyanidanol-3 changes functional properties of collagen.

About 6-7 (+)-cyanidanol-3 molecules are bound per collagen alpha-chain. The (+)-cyanidanol-3 treated collagen contains an increased number of pepsin-resistant cross-links, is less susceptible to attack by mammalian collagenase, has a higher shrinkage temp and forms unstructured aggregates. Cell and organ culture studies show that these biological systems produce less protein and collagen in the presence of (+)-cyanidanol-3 and that the newly synthesized collagen is less soluble.

Benzopyrans↗
PubMed1982

Cartilage specific collagen activates macrophages and the alternative pathway of complement: evidence for an immunopathogenic concept of rheumatoid arthritis.

We studied the effect of human interstitial collagen types I, II, and III on serum-free cultured mouse macrophages and on the complement classical and alternative pathways in human and guinea-pig serum. Type II collagen produced a dose-dependent consumption and conversion of C3 and factor B both in the homologous and in the heterologous system. This effect on the alternative pathway was reproduced in genetically C4-deficient guinea-pig serum and could be triggered by native, triple helical type II molecules, by their component alpha chains, and the CNBr peptide mixture. Addition of type II collagen to the mouse macrophage cultures induced not only a dose- and time-dependent secretion of lysosomal enzymes, but also the generation of a supernatant factor cytotoxic for mouse mastocytoma P 815 cells. Collagen of types I and III were conspicuously less active or inactive in all assays. The studies demonstrate properties of the collagen specific for cartilage which, on a molecular level, suggest its direct, local participation in the production and perpetuation of rheumatoid arthritis.

Animals↗