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Biomedical subjects

J Frey

Publications and source records attributed to J Frey.

At least 325 records · Page 18Linked to original sources
PubMed1965

Immunoelectrophoresis reveals collagen solubility in human serum.

A fraction of humanserum proteins which contains hydroxyproline migrates, on electrophoresis, with the alpha(2)-beta-globulins. Immunoelectrophoresis with rabbit antiserum to soluble human collagen reveals an immunologically collagen-like protein in the human serum.

Animals↗
PubMedDate not supplied

Characterization of human osteoblastic cells: influence of the culture conditions.

Human osteoblastic cells were isolated enzymatically from adult human spongy bone and grown in MEM-Ham F12 1:1 medium supplemented with 2% Ultroser (USM). They were subcultured and examined for osteoblast features by morphological, histological, and biochemical approaches. The cells had a characteristic polyhedral morphology and produced a high level of alkaline phosphatase (ALKP). Confluent cultures were uniformly stained for ALKP and flow cytometry analysis with fluorescein diphosphate gave a single peak signal, reflecting a highly positive population, distinct from cultures of fibroblasts. The ALKP activity was stimulated by 1,25 (OH)2 vitamin D3. CD 44 was strongly expressed in these cultures, although osteoblasts are negative in vivo and osteocytes are positive. The main collagen synthesized was type I collagen and osteocalcin was produced after stimulation by vitamin D3. 10 mM betaGP induced mineralization and microprobe analysis of the crystals showed a composition close to hydroxyapatite. Changing the culture conditions to MEM-10% calf serum acted on cell behavior: it reduced the production of these biochemical markers of osteoblasts and the morphology became fibroblastlike with more rapid cell multiplication. The parameter most affected by the change in culture medium was ALKP, which was selected as the determinant criterion for defining an osteoblast culture. ALKP activity was then used to characterize a culture of cells seeded in a collagen gel.

Adult↗
PubMedDate not supplied

Construction of a broad host range shuttle vector for gene cloning and expression in Actinobacillus pleuropneumoniae and other Pasteurellaceae.

We have constructed a pair of broad host range expression vectors, pJFF224-NX and pJFF224-XN, based on plasmid RSF1010, which enable cloning and efficient expression of genes in Actinobacillus pleuropneumoniae and Pasteurella haemolytica and in Escherichia coli. The vectors consist of the minimal autonomous replicon of the broad host range plasmid RSF1010 and a type II chloramphenicol acetyl transferase gene for chloramphenicol resistance selection. In addition, they contain a gene expression cassette based on the E. coli bacteriophage T4 gene 32 promoter region and a transcription stop signal, which are separated by a segment of multiple cloning sites in both orientations. Electroporation and subsequent selection for chloramphenicol resistance was used for the introduction of the vectors in A. pleuropneumoniae and P. haemolytica. A promoterless xy/E gene from the Pseudomonas putida TOL plasmid was cloned onto pJFF224-NX. This plasmid enabled efficient expression of active catechol2,3oxygenase in A. pleuropneumoniae and P. haemolytica. It was stably maintained in A. pleuropneumoniae without antibiotic selection, showing less than 0.1% loss after 100 generations, while native RSF1010 and other RSF1010-based vectors were unstable in this host.

Actinobacillus pleuropneumoniae↗
PubMedDate not supplied

Reduced body fat in long-term followed-up female patients with anorexia nervosa.

We aimed to evaluate both body composition and serum leptin levels in females with a past history of anorexia nervosa (AN) adjusted for their current body mass index (BMI). Twenty-three females with a past history of AN were followed-up 10 years after inpatient treatment and compared to 23 female controls of a similar age range matched for BMI on a one to one basis. Serum leptin levels were assessed and percent body fat (%BF) was determined via bioelectric impedance analysis. Differences of both %BF and leptin levels between cases and controls were tested under the hypothesis that cases have lower %BF and lower serum leptin levels than the controls. %BF was indeed lower in the cases compared to the controls (p < 0.05). However, differences in leptin levels between both groups just failed significance (p = 0.051). We conclude that body composition differs between long-term followed-up patients with AN and BMI- and gender-matched controls. Based on the finding that the former patients reported being more physically active, we assume that the higher physical activity levels in recovered patients with AN underlie the lower %BF.

Adipose Tissue↗