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Biomedical subjects

G Jahn

Publications and source records attributed to G Jahn.

At least 127 records · Page 7Linked to original sources
PubMed1989

Isolated pericardial relapse following allogeneic bone marrow transplantation for acute myelogenous leukemia.

A 34-year-old male patient developed an isolated pericardial relapse of an acute myelogenous leukemia (M3) 11 months after marrow grafting from his HLA-identical brother. Alloenzyme pattern analysis revealed recipient type of the myeloblasts obtained from the pericardial effusion. Recurrence of the original leukemia was preceded by a reactivation of latent cytomegalovirus (CMV) infection which, in spite of a systemic humoral immune response to the virus, persisted in the pericardium as shown by dot-blot hybridization using CMV-specific DNA fragments. Activated T cells propagated with IL-2 from the pericardial effusion did not reveal any cytotoxic or restimulation capacity on the original or relapse myeloblasts, nor on other donor, recipient or NK target cells. Local coincidence of virus persistence and leukemic relapse suggested CMV-mediated modulation of the immune response in the pericardium with consequent induction of a proliferation of the original malignant cell clone. After local chemotherapy and one course of systemic treatment the patient is still in complete remission--longer than after the marrow grafting.

Adult↗
PubMed1989

[Validity of immunohistology and in situ hybridization in the differential diagnosis of cytomegalovirus pneumonia and idiopathic interstitial pneumonia after allogenic bone marrow transplantation].

Interstitial pneumonia (IP) is currently the most frequent and severe complication of allogeneic bone marrow transplantation (BMT). Post-BMT-IP is due partially to infection by cytomegalovirus (CMV-IP) and partially to idiopathic induction (IIP). Because of the different therapeutic consequences it is important to distinguish between these two kinds of pneumonia. Therefore, the validity of immunohistochemistry (IHC) and in situ hybridization (ISH) for the differential diagnosis of CMV-IP and IIP was studied. The investigations were performed using postmortem tissue samples (lung) of 23 patients decreased after allogeneic BMT. In 22 of the 23 patients the primary cause of death was IP (CMV 13x, idiopathic 7x, pneumocystis 1x, toxoplasmosis 1x). One patient died from thrombopenic cerebral bleeding. All 3 CMV-detecting systems tested disclosed certain advantages and disadvantages. The sensitivity of routine histology was 12/13 (92.3%), of IHC 13/13 (100%), and of ISH 12/13 (92.3%). The specificity corresponded to the order: ISH greater than IHC greater than histology. The application of ISH and IHC did not change significantly the routine histologic classification of pneumonias into CMV-IP and IIP. The validity of the three procedures used for detecting CMV in patients after allogeneic BMT is discussed in detail.

Bone Marrow Transplantation↗
PubMed1988

Delayed seroconversion to HIV in a hemophiliac.

In a 14-year-old boy with severe hemophilia B, HIV seroconversion was observed about 2 years after substitution therapy had been changed to heat-treated PPSB concentrates. This shows that HIV-antibodies may appear in hemophiliacs after time periods longer than generally assumed.

Acquired Immunodeficiency Syndrome↗
PubMed1988

[Congenital cytomegalovirus infection with fatal outcome].

A 34-year-old woman had an essentially uneventful pregnancy until membrane rupture in the 30th week of pregnancy. She developed severe eclampsia necessitating delivery by section in the 36th week. The child was asphyxic at birth with petechial haemorrhages and hepatosplenomegaly, suggesting cytomegalovirus infection (CMV). He died on the fourth day. Virus could not be isolated from maternal urine, cervical smear and placental tissue, but was demonstrated in the child's urine and post-mortem in lung and liver tissue. The ELISA test on the child's serum was positive for CMV-specific IgM antibodies.

Adult↗
PubMed1988

Detection of human cytomegalovirus DNA and viral antigens in tissues of different manifestations of CMV infection.

Biopsy and autopsy specimens from 22 patients with cytomegalovirus (CMV) infections were investigated by means of in situ hybridization (ISH) to detect viral DNA and by immunohistochemistry (IHC) to visualize viral proteins. Both methods proved to be valuable tools for histopathology. ISH sometimes recognized cells that did not show typical CMV inclusions. An antiserum against the full spectrum of viral proteins (non-infectious enveloped particles) detected most cytomegalic cells in disseminated and organ-limited infections. An antiserum against a recombinant polypeptide (XP1) was particularly useful in connatal CMV infections and organ-limited infections. We have demonstrated that IHC and ISH studies in parallel are the best approach to the detection of CMV infections in pathological specimens.

Adolescent↗
PubMed1988

[Interpretation of varicella serology in pregnancy].

Chickenpox during pregnancy may result in a severe, in some cases fatal, generalized infection of the newborn. Pregnant women with unknown Varicella-Zoster-virus (VZV) immunity, who have had contact with an individual infected by chickenpox, should be tested immediately for specific antibodies to VZV. The interpretation of test results may be difficult under certain circumstances. This problem is discussed using individual case studies.

Antibodies, Viral↗
PubMed1988

Prokaryotic expression of immunogenic polypeptides of the large phosphoprotein (pp150) of human cytomegalovirus.

The large phosphorylated matrix protein pp150 of human cytomegalovirus (HCMV) is the polypeptide most frequently reactive in immunoblotting analyses with human antisera when compared with other viral proteins. Several defined regions of pp150 were expressed as beta-galactosidase fusion proteins and these were tested for their immunoreactivity with human sera and their immunogenicity. One antigenic region could be expressed in large amounts and was found to carry immunodominant epitopes, as shown by immunoblotting and ELISA. A rabbit antiserum raised against recombinant pp150 antigens produced in bacteria proved to be useful for immunofluorescence and immunohistochemistry studies of HCMV-infected cells and tissues. The results suggest that this anti-pp150 serum will help to elucidate the process of virus assembly and antigen detection in infected cells.

Animals↗
PubMed1988

Abundant 5 kb RNA of human cytomegalovirus without a major translational reading frame.

Although all herpesviruses are similar in their temporal regulation of gene expression, the organization of the immediate early (IE) genes varies markedly between the different members of the group. Most of the IE transcripts of human cytomegalovirus originate from a restricted region within the long unique segment of its linear dsDNA genome of 235 kb. One of the predominant transcripts from the IE region is a 5 kb RNA. Northern blot analyses revealed that this class of RNA is continuously present in infected cells. It was detected at high levels in IE and late RNA preparations, and in low amounts in early RNA preparations. It was not confined to the poly(A)+ fraction upon oligo(dT) selection, but also appeared in similar amounts in poly(A)- fractions. Fine mapping of this transcript was done by nuclease protection and primer extension. The RNA appeared to be unspliced, and no signals such as TATA or CCAAT, known to be important elements in eukaryotic RNA polymerase II promoters, were found close to the 5' end. Sequence analysis revealed multiple stop codons throughout the AT-rich potential coding region. Since no splicing was found to occur, the largest protein deduced from the DNA sequence would be of not more than 12,000 Mr. However, a computer program designed to detect protein-coding DNA sequences by codon usage did not reveal significant evidence for a protein encoded in this region. Therefore this RNA is likely to represent an unprecedented case of a large non-coding transcript present in cells that are lytically infected by an animal virus.

Base Sequence↗
PubMed1988

Immunoreactivity of human immunodeficiency virus (HIV-1) envelope polypeptides expressed in Escherichia coli.

Defined cDNA sequences encoding segments of envelope glycoproteins of the human immunodeficiency virus were expressed in E. coli. The recombinant env fusion proteins were tested for immunoreactivity with patient sera by radio immunoprecipitation procedures. The regions of the env proteins, carrying relevant antigenic determinants in respect to diagnostic purposes, could be identified.

Cloning, Molecular↗
PubMed1987

[Serologic AIDS diagnosis with polypeptides obtained by genetic technics of the human immunodeficiency virus (HIV-1)].

Serologic testing for human immunodeficiency virus type 1 (HIV-1) is currently based on enzyme linked immunosorbent assay (ELISA) as screening method. Positive ELISA-results have to be confirmed by at least one second procedure such as Western blotting or immunofluorescence. To obtain new diagnostic reagents for confirmatory testing, we expressed viral antigens in procaryotic systems. Peptides representing epitopes of structural core (gag)- and envelope (env)-proteins of HIV were produced in E. coli as stable immunogenic beta-galactosidase fusion proteins. Recombinant proteins were taken for immunoblot-assays. The results of Western blotting with those fusion proteins were in general comparable with conventional ELISA, immunofluorescence, immunoblot with cell-culture derived virus and commercially available ELISA tests based on recombinant proteins. Immunoblots using recombinant transmembrane protein (gp41) derived polypeptide were more sensitive than the conventional procedure with purified virion proteins. Western blotting with recombinant fusionproteins provide reliable and inexpensive serodiagnostics without handling of infectious cell cultures.

Acquired Immunodeficiency Syndrome↗
PubMed1987

The two major structural phosphoproteins (pp65 and pp150) of human cytomegalovirus and their antigenic properties.

Human cytomegalovirus (HCMV) purified from cell culture contains two dominant structural phosphoproteins with apparent molecular weights of 65,000 and 150,000, designated as pp65 and pp150 respectively. The humoral immune response of infected individuals against pp65 is relatively weak and is not always detectable by Western blot analyses. This report shows that recent clinical isolates of HCMV do not necessarily have pp65 as a prominent constituent, suggesting that the low immune reaction is due to variable expression of the pp65 in natural infections. However, the HCMV strains tested in this study produced the large structural phosphoprotein (pp150) in about equal amounts. The pp150 is remarkably immunogenic, if compared with all other virion constituents; serum pools and individual sera from HCMV-infected patients recognized this particular protein intensively in immunoblot assays. Thus, phosphoprotein pp150 seems to be the primary polypeptide candidate for expression cloning in order to develop reagents for novel ways of HCMV diagnosis.

Antibodies, Viral↗
PubMed1987

Genomic localization, sequence analysis, and transcription of the putative human cytomegalovirus DNA polymerase gene.

The human cytomegalovirus (HCMV)-induced DNA polymerase has been well characterized biochemically and functionally, but its genomic location has not yet been assigned. To identify the coding sequence, cross-hybridization with the herpes simplex virus type 1 (HSV-1) polymerase gene was used, as suggested by the close similarity of the herpes group virus-induced DNA polymerases to the HCMV DNA polymerase. A cosmid and plasmid library of the entire HCMV genome was screened with the BamHI Q fragment of HSV-1 at different stringency conditions. One PstI-HincII restriction fragment of 850 base pairs mapping within the EcoRI M fragment of HCMV cross-hybridized at Tm - 25 degrees C. Sequence analysis revealed one open reading frame spanning the entire sequence. The amino acid sequence showed a highly conserved domain of 133 amino acids shared with the HSV and putative Epstein-Barr virus polymerase sequences. This domain maps within the C-terminal part of the HSV polymerase gene, which has been suggested to contain part of the catalytic center of the enzyme. Transcription analysis revealed one 5.4-kilobase early transcript in the sense orientation with respect to the open reading frame identified. This transcript appears to code for the 140-kilodalton HCMV polymerase protein.

Amino Acid Sequence↗
PubMed1987

Map position and nucleotide sequence of the gene for the large structural phosphoprotein of human cytomegalovirus.

Human cytomegalovirus particles contain a phosphoprotein of 150,000 (pp150) apparent molecular weight in their matrix; the protein appears particularly reactive in Western blot analyses with human antisera. The gene for pp150 was mapped by screening a bacteriophage lambda gt11 cDNA expression library with monospecific rabbit antisera. Subsequent hybridization of cDNA with cosmid and plasmid clones containing the human cytomegalovirus strain AD169 genome mapped the gene to HindIII fragments J and N. The gene is transcribed into a late 6.2-kilobase RNA. The nucleotide sequence of this region was determined, and a transcription initiation site and two polyadenylation sites of an abundant transcript were located by primer extension and nuclease protection experiments. The reading frame for pp150, deduced from computer analyses, gives rise to a polypeptide of 1,048 amino acids in length; protein secondary structure analysis revealed multiple beta-pleated sheets in hydrophilic clusters, providing a possible explanation for the immunogenic properties of the polypeptide.

Amino Acid Sequence↗
PubMed1987

Measurement by radioimmunoassay of casein content in rabbit mammary gland during pregnancy and after prolactin stimulation in organ culture.

A specific homologous radioimmunoassay was developed to measure rabbit beta-casein in rabbit mammary gland with a sensitivity of 0.5 ng/ml protein. It was used to measure casein concentration during pregnancy and in organ culture of mammary gland explants. Casein was detectable in virgin mammary glands, showed a small increase during the first half of pregnancy, increased more than 20-fold between Days 21 and 27, and diminished somewhat on the first days of lactation. After 24 hr of culture, mammary gland explants had no detectable casein, but the addition of increasing concentrations of prolactin to a culture medium which contained insulin (5 micrograms/ml) and cortisol (0.5 microgram/ml) induced a regular increase in the casein content of the tissue. Casein started to increase when 10 ng/ml of prolactin was present and maximal values were achieved for 100 ng/ml of the hormone.

Animals↗
PubMed1986

[Chlamydia trachomatis infection in a patient with condylomata acuminata].

Chlamydia trachomatis cervical infection was observed in a 19-year-old woman with genital condylomata acuminata. To isolate C.trachomatis, cycloheximide-treated McCoy cells and a culture-independent monoclonal antibody were used. In addition, a single-antigen immunofluorescence test was made to determine the chlamydia antibody titer. Condylomata acuminata are induced by human papillomaviruses (HPV), predominantly types 6 and 11. This case shows that simultaneous genital infection of C.trachomatis and HPV requires special attention.

Adult↗
PubMed1986

[Neonatal blennorrhea caused by Chlamydia trachomatis].

Chlamydial conjunctivitis was diagnosed in a 5-day-old male newborn. Under treatment with erythromycin the clinical picture of intense swelling of the lid and the copious purulent discharge abated during the following 2 days. Chlamydia trachomatis has become worldwide the most prevalent causative agent of neonatal conjunctivitis.

Bacteriological Techniques↗
PubMed1986

[Colchicine therapy of fibrosing liver diseases--report of a randomized double-blind study].

It is reported on results of a double blind study of colchicine therapy in fibrotic liver diseases over a period of three years. The study includes 74 probands; 37 of them had been treated after randomization for five days a week with 4 X 0,25 mg/d colchicine, 37 with placebo. 53 probands attained the 12th month of treatment, 43 of them 24th, 24 probands were in the study for 36 months. 3 diagnoses groups had been formed with regard to the histological grades of fibrosis: chronic hepatitis (without structural transformation); structural liver transformation/moderate liver cirrhosis; severe liver cirrhosis. In 38 cases the disease was caused by alcohol. 45 data had been studied (clinical results, paraclinical data concerning hepatological diagnostic and connective tissue metabolism and morphologic data). The biometric evaluation was carried out with the stage variant analysis by Friedman. Rebiopsies have been carried out in 40 probands after 1 year, in 4 probands after 2 years. 4 data (Serumalbumine, Gamma-GT, ALAT, KP) showed significant changes in the colchicine-group as well as in the placebo-group. In both therapy groups the morphologic supervisions of the fibrosis grades (rebiopsies) showed improvements, no changes, and deterioration about in the same frequency. In this study there was no effectiveness of colchicine on the course of fibrotic liver diseases to be stated. Concerning the contradictions in the recent literature and probable the insufficient colchicine dose, the authors recommend further studies on colchicine therapy in liver diseases with incipient i.e. reversible fibrosis.

Clinical Trials as Topic↗