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Biomedical subjects

F Meyer

Publications and source records attributed to F Meyer.

At least 217 records · Page 12Linked to original sources
PubMed1986

Endogenous sex hormones, prolactin, and mammographic features of breast tissue in premenopausal women.

The relationship between levels of certain endogenous hormones and the mammographic features of breast tissue was evaluated in 110 premenopausal women who were referred to hospital-based radiology units for a routine xeromammogram. This analysis was based on specimens collected during the luteal phase of the menstrual cycle. Plasma 17 beta-estradiol, progesterone, and prolactin were measured, as well as urine estrone, estradiol, estriol, and pregnanediol. The main xeromammographic features of the breast assessed were Wolfe's parenchymal pattern and the percentages of the breast showing nodular densities and homogeneous density. In these data, endogenous hormones were not strongly associated with mammographic features of breast tissue. However, women with the N1 and P1 parenchymal patterns had somewhat higher levels of estrogens and prolactin and somewhat lower levels of progesterone than women with the P2 and DY patterns.

Adult↗
PubMed1986

Biological activities and receptor binding of two human recombinant interferons and their hybrids.

Two human recombinant lymphoblastoid interferon-alpha subtypes, LyIFN-B (alpha 8) and LyIFN-D (alpha 1), and 10 hybrids generated therefrom were produced in Escherichia coli and purified. The antiviral and antiproliferative activities and the induction of (2'-5')oligoadenylate synthetase were compared to their receptor binding affinities. The IFN subtypes and their hybrids had similar specific antiviral activities on bovine cells. On human cells both the specific antiviral and antiproliferative activities of LyIFN-B were about 30-fold higher than those of LyIFN-D. This difference in activity could be attributed partly to the N-terminal amino acids 1 to 60 and partly to amino acids 61 to 92. A third domain affecting the biological activities was found within the carboxy-proximal segment from amino acids 93 to 150. The differences in these activities were found to correlate with their ability to bind the receptor, suggesting that the differences in activity might be due to altered binding of the IFNs to the cellular receptors. In contrast, the induction of (2'-5')oligoadenylate synthetase did not follow the same activity profile. On mouse cells, the efficiency of the hybrids was affected by at least four sites on the IFN protein. A hybrid with the N-terminal segment 1 to 60 from IFN-B and amino acids 61 to 166 from IFN-D had a specific antiviral activity on mouse cells as high as on human cells corresponding to a 500- and 5000-fold increase in specific activity compared to IFN-D and IFN-B, respectively. We suggest that on mouse cells the IFN activity may be more dependent on conformational differences than on human cells, which in turn might reflect a less precise fit to the mouse receptor than to the human receptor.

2',5'-Oligoadenylate Synthetase↗
PubMed1985

[Evaluation of erythrocyte survival by the determination of glycosylated hemoglobin. Clinical value].

In normoglycaemic subjects the haemoglobin glycosylation rate primarily depends on duration of erythrocyte life. Measurements of glycosylated haemoglobin therefore can be used to evaluate erythrocyte life. Indeed, glycosylated haemoglobin is significantly reduced (p less than 0.001) in patients with autoimmune haemolytic anaemia or Minkowski-Chauffard syndrome as compared with patients with non-haemolytic anaemia. In addition, there is a strong correlation (r = 0.92) in non-diabetic subjects between the level of glycosylated haemoglobin and the percentage of daily haemolysis, as determined by a method using 51 Cr-labelled antologous red cells.

Anemia↗
PubMed1985

Automated recognition of atypical nuclei in breast cancer cytology specimens by iterative image transformations.

In order to develop an objective grading system for nuclear atypia in breast cancer, an image analysis technique has been applied for the automated recognition of enlarged and hyperchromatic nuclei in cytology specimens. The image segmentation algorithm, based on the 'top hat' image transformation developed in mathematical morphology, is implemented on the LEYTAS automated microscope system. The performance of the segmentation algorithm has been evaluated for fifty malignant and eighty-five benign breast lesions by visual inspection of the displayed 'flagged' objects. The mean number of flagged objects per 1600 image fields for breast cancers was 887 (range 0-7920) of which 87% consisted of single, atypical nuclei. For benign lesions the mean number was 30 (range 0-307) of which 20% were single nuclei. By adaptation of the 'top hat' parameter values, a more extreme subpopulation of atypical nuclei could be discriminated. The large interspecimen variation in the breast cancer results was related to differences in DNA content distribution and mean nuclear area, determined independently with scanning cytophotometry, and to some extent with the histological type.

Breast Neoplasms↗
PubMed1985

Transplant of rhesus-positive bone marrow in a rhesus-negative woman having anti-rhesus D alloantibodies.

A woman affected by acute myeloblastic leukemia was grafted with HLA A, B and D compatible rhesus-positive bone marrow from her brother. Before grafting, she had anti-D alloantibodies (1/512 IAT, 2.9 micrograms/ml). To prevent the destruction of donor red blood cells, four plasma exchanges and a conditioning regimen (total-body irradiation 800 rad, cyclophosphamide, methotrexate) were carried out to decrease anti-D from 2.9 to less than 0.02 micrograms/ml on day 0. The anti-D level was 0.8 micrograms/ml on day 12 and was decreased to 0.2 micrograms/ml by eight plasma exchanges until day 35. Anti-D antibodies were undetectable with Lalezari's technique on day 45. Engraftment was obtained on day 25 (3,000 leukocytes/mm3 and 50% erythroblasts in bone marrow). The patient died from aspergillosis and graft-versus-host disease on day 54. This observation shows that an engraftment of rhesus-positive bone marrow in a recipient with anti-D antibody is possible.

Adult↗
PubMed1984

A large fragment approach to DNA synthesis: total synthesis of a gene for the protease inhibitor eglin c from the leech Hirudo medicinalis and its expression in E. coli.

A DNA containing the coding sequence for the proteinase inhibitor protein, eglin c, from the leech Hirudo medicinalis has been obtained by enzymatic assembly of chemically synthesized DNA fragments. The synthetic gene consists of a 232 base-pair fragment containing initiation and termination codon signals with restriction enzyme recognition sites conveniently placed for cloning into a plasmid vector. Only six oligonucleotides from 34 to 61 bases in length, sharing pairwise stretches of complementary regions at their 3'-termini, were prepared by phosphotriester solid-phase synthesis. The oligomers were annealed pairwise and converted into double stranded DNA fragments by DNA polymerase I mediated repair synthesis. The fragments were assembled by ligation, and the synthetic gene was expressed in high yield in E. coli under the transcriptional control of the E. coli tryptophan promoter. The expression product was purified to homogeneity and was shown to have similar physicochemical and identical biological properties as the authentic protein isolated from the leech.

Amino Acid Sequence↗
PubMed1984

[A case of hemolytic disease in a newborn associated with anti-Wra (WRIGHT) antibodies].

A french woman delivered a third full-term male baby who had a strongly positive direct antiglobulin test. During the pregnancy and after the delivery, the woman had a negative irregular antibody screening test using standard red blood cell panels. The compatibility testing between the mother's serum and the father's red blood cells was strongly positive and the antibody was identified as an anti-Wra. The baby developed a mild hyperbilirubinemia and recovered without treatment. This child was probably responsible for his mother's immunization since the two previous children were Wra negative and the mother had no history of blood transfusion or abortion.

Antibodies↗
PubMed1984

Detection in situ of gamma-ray-induced DNA strand breaks in single cells: enzymatic labelling of free 3'-OH ends.

We report a procedure allowing the detection and counting of free 3'-OH DNA strand extremities in single cells in situ. Terminal transferase (TdT) catalysed the incorporation of 3H-dGMP into fixed nuclei of human colonic adenocarcinoma cells (HT29), using free 3'-OH ends as initiator. Radioactivity was detected by autoradiography and determined quantitatively with a rapid image-processing system for grain counting. The initiator activity for TdT increases with the dose of gamma-rays in the dose range 2.5-20 Gy.

Adenocarcinoma↗
PubMed1984

Improvement of enzyme-linked antiglobulin test by using an antiglobulin linked to glucose oxidase: description of the technique.

The classic enzyme-linked antiglobulin test (ELAT) used to detect and quantify the amount of IgG antibodies on red blood cells (RBC) is sensitive to hemolysis and erythrocyte enzymatic activities. We describe a new ELAT by using glucose oxidase (GO) linked to antihuman IgG. The optical density base line of GO-ELAT, alkaline phosphatase-ELAT and peroxidase-ELAT were, respectively, 0.180, 0.350 and 0.550. This very low baseline of GO-ELAT was due to the absence of hemolysis (the pH of the GO substrate is 6.5). This technique is ten times more sensitive than the indirect antiglobulin test and detects up to 1 ng/ml of anti-D alloantibodies. Additional advantages of the technique are (1) there is no intrinsic GO enzyme in RBC, and (2) it is not necessary to fix the RBC.

Alkaline Phosphatase↗
PubMed1984

[Hemolytic disease of the newborn caused by maternal allo-immunization against erythrocyte antigens other than A, B and rhesus D].

The authors analyse numerous publications dealing with hemolytic disease of the newborn due to erythrocyte antigens other than A, B and Rhesus D. They emphasize the frequency of these diseases and the clinical presentation according to the antibody specificity. Finally, they suggest a practical management to treat these hemolytic diseases of the newborn.

Blood Group Antigens↗
PubMed1984

[124 cases of hemolytic diseases in newborn infants other than ABO and Rhesus D observed in the Blood Transfusion Center of Lyon between 1970 and 1982].

Between 1970 and 1982, 124 cases of hemolytic diseases of the newborn due to antigens other than A, B and Rhesus-D were observed in the Blood Bank of Lyon (France). These cases represent 10,3% of all the hemolytic diseases of the newborn (ABO excluded). This percentage has raised during this period: 2,1% in 1970 until 39,2% in 1982. The variation is due both to the fall of the Rhesus-D hemolytic diseases and to the raise of non Rhesus-D hemolytic diseases. The alloantibody titer is not a good criteria in order to predict the anemia level of the newborn but the amniotic fluid delta OD 450 is satisfactory whatever the alloimmunisation is.

Erythroblastosis, Fetal↗
PubMed1984

[Hemolytic disease of newborn infants caused by anti-Diego antibodies].

A native Cambodian woman delivered a third full-term female baby who had a strongly positive direct antiglobulin test. During the pregnancy and after the delivery, the woman had a negative irregular antibody screening test using standard red blood cell panels, but the indirect antiglobulin test between the mother's serum and the father's red blood cells was strongly positive. The antibody could be eluted from the baby's red blood cells and its was identified as an anti-Dia (Diegoa). The child developed a mild hyperbilirubinemia and recovered without treatment.

Blood Group Antigens↗
PubMed1984

[Possible difference in elastin content between the right and left lung in rats].

Elastin and collagen were measured on separate right and left lungs of rats, within two age-groups : 3 months and 8-15 months. The elastin content was significantly higher in the left series. An explanation based upon the bronchovascular density was tested and the results suggest a difference in regard to the development of the parenchyma surrounding the left bronchovascular tree. The knowledge of such peculiarities, if they are confirmed, may help understanding the structural basis of function, by the means of separate tests of mechanical properties.

Animals↗
PubMed1983

Unusual splice sites revealed by mutagenic inactivation of an authentic splice site of the rabbit beta-globin gene.

Only one of six point mutations of the sequence around one end of the larger of the introns of the rabbit beta-globin gene seriously affects the normal removal of the intron and splicing of the gene. That mutation converts a GT sequence, invariably found at the 5' end of introns, into an AT, which is no longer recognized as a signal for intron removal. Instead, three normally unused (cryptic) sites are used, leading to aberrant gene transcripts. One of the cryptic sites is an exception to the invariable GT sequence.

Animals↗