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Biomedical subjects

P Emmerich

Publications and source records attributed to P Emmerich.

26 records · Page 2Linked to original sources
PubMed1989

Double in situ hybridization in combination with digital image analysis: a new approach to study interphase chromosome topography.

Double in situ hybridization with mercurated and biotinylated chromosome specific DNA probes in combination with digital image analysis provides a new approach to compare the distribution of homologous and nonhomologous chromosome targets within individual interphase nuclei. Here we have used two DNA probes representing tandemly repeated sequences specific for the constitutive heterochromatin of the human chromosomes 1 and 15, respectively, and studied the relative arrangements of these chromosome targets in interphase nuclei of human lymphocytes, amniotic fluid cells, and fibroblasts, cultivated in vitro. We have developed a 2D-image analysis approach which allows the rapid evaluation of large numbers of interphase nuclei. Models to test for a random versus nonrandom distribution of chromosome segments are discussed taking into account the three-dimensional origin of the evaluated 2D-distribution. In all three human diploid cell types the measurements of target-target and target-center distances in the 2D-nuclear image revealed that the labeled segments of the two chromosomes 15 were distributed both significantly closer to each other and closer to the center of the nuclear image than the labeled chromosome 1 segments. This result can be explained by the association of nucleolus organizer regions on the short arm of chromosome 15 with nucleoli located more centrally in these nuclei and does not provide evidence for a homologous association per se. In contrast, evaluation of the interphase positioning of the two chromosome 1 segments fits the random expectation in amniotic fluid and fibroblast cells, while in experiments using lymphocytes a slight excess of larger distances between these homologous targets was occasionally observed. 2D-distances between the labeled chromosome 1 and 15 segments showed a large variability in their relative positioning. In conclusion our data do not support the idea of a strict and permanent association of these homologous and nonhomologous targets in the cell types studied so far.

Cell Nucleolus↗
PubMed1989

Interphase cytogenetics in paraffin embedded sections from human testicular germ cell tumor xenografts and in corresponding cultured cells.

A protocol was developed that allows determination of chromosome aberrations in interphase nuclei from paraffin embedded human tissues. As a model system tissue sections from xenografts derived from three testicular germ cell tumors (two teratocarcinoma and one embryonal carcinoma), as well as sections from normal intestine and testicular tissues, were hybridized with a biotin-labeled DNA probe specific for 1q12. For comparison, isolated nuclei in suspension and metaphase spreads from in vitro cell lines derived from the respective xenografts were assayed. Our results show that interphase tumor cells with aberrant numbers of chromosome 1 can be reliably detected both in vitro and in vivo. Subclones with two and three labeled chromosomes, respectively, could be defined and quantitatively evaluated. Present and future possibilities to pinpoint specific chromosome aberrations directly in cells present in body fluids or in tumor tissues are discussed.

Animals↗
PubMed1989

Supernumerary chromosome 1 in interphase nuclei of atypical germ cells in paraffin-embedded human seminiferous tubules.

The so-called atypical germ cells or cells of carcinoma in situ morphologically resemble neoplastic cells in seminoma. Since seminomas show numerical aberrations of chromosome 1 we have used a DNA probe specific for chromosome region 1q12 to determine whether such aberrations can be detected in atypical germ cell nuclei in paraffin-embedded seminiferous tubules as well. One-third of intratubular nuclei, containing atypical germ cells, consistently showed three hybridization signals in contrast to two signals regularly observed in normal intestine and in spermatogonia. We thus show that cytogenetic studies of precancerous cells can be performed directly on the tissue where these cells originate.

Chromosome Aberrations↗
PubMed1988

[Hantaan virus infections as a cause of acute kidney failure. 3 cases in West Germany].

Three cases of Hantaan virus infection (Korean haemorrhagic fever) leading to acute renal failure are described. All three had mild haemorrhagic fever with a renal syndrome. It had started with acute fever followed by oliguria, proteinuria and microhaematuria (in two patients) in the further course of the disease, as well as urea and creatinine retention. One patient needed to be dialysed twice. Hantaan virus-specific IgG antibodies were demonstrated in all three patients; one also had IgM antibodies.

Acute Kidney Injury↗
PubMed1985

Simple detection of antibodies to different viruses using rheumatoid factor and enzyme-labelled antigen (ELA).

A new one-step method was developed to detect IgG antibodies to different virus antigens. Human serum specimens were mixed with different enzyme-labelled antigen (ELA) preparations in microtitre plates coated with rheumatoid factor (RF). During the incubation in the wells of microtitre plates immune complexes form which are specifically bound to the RF on the solid phase. The test detects antibody to cytomegalovirus (CMV) and West-Nile virus with a high sensitivity and specificity.

Antibodies, Viral↗
PubMed1984

Detection of specific immunoglobulin M antibody to different flaviviruses by use of enzyme-labeled antigens.

An enzyme immunoassay was developed for the detection of human immunoglobulin M (IgM) antibody to different flavivirus antigens. The IgM antibody of human sera was selectively bound to anti-IgM antibody-coated solid-phase plates. Flavivirus IgM antibodies were then detected by use of various enzyme-labeled antigens. The flavivirus antigens (dengue type 2 virus, West Nile virus, and tick-borne encephalitis virus) were produced in suckling mice. The antigens were labeled with horseradish peroxidase by adding the activated enzyme at alkaline pH to sucrose-acetone-treated antigens. Addition of unlabeled mouse brain suspension of uninfected animals to the diluted enzyme-labeled antigens effectively reduced nonspecific binding to the solid phase. In patients with acute flavivirus infections, viral IgM antibody could be demonstrated with high sensitivity. Furthermore, the enzyme-labeled antigen-IgM test showed greater specificity than the hemagglutination inhibition test.

Adult↗
PubMedDate not supplied

Imported lassa fever in Germany: molecular characterization of a new lassa virus strain.

We describe the isolation and characterization of a new Lassa virus strain imported into Germany by a traveler who had visited Ghana, Côte D'Ivoire, and Burkina Faso. This strain, designated "AV," originated from a region in West Africa where Lassa fever has not been reported. Viral S RNA isolated from the patient's serum was amplified and sequenced. A long-range reverse transcription polymerase chain reaction allowed amplification of the full-length (3.4 kb) S RNA. The coding sequences of strain AV differed from those of all known Lassa prototype strains (Josiah, Nigeria, and LP) by approximately 20%, mainly at third codon positions. Phylogenetically, strain AV appears to be most closely related to strain Josiah from Sierra Leone. Lassa viruses comprise a group of genetically highly diverse strains, which has implications for vaccine development. The new method for full-length S RNA amplification may facilitate identification and molecular analysis of new arenaviruses or arenavirus strains.

Adult↗