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E Burkhardt

Publications and source records attributed to E Burkhardt.

At least 37 records · Page 2Linked to original sources
PubMed1995

[Two mesenchymal tumor cell lines for the determination of natural killer (NK) cell activity in the peripheral blood of dogs].

The two mesenchymal cell lines K1 and K6 were established from round cell tumours located at the lips of two dogs. Both cell lines were characterized as being of myelomonocytic origin by morphological, cytochemical, immunocytochemical and functional criteria. In the 51chromium release assay (effector/target cell ratio 100/1) the K6-cell line revealed a mean cytotoxic sensitivity of 53.6% and thus showed a susceptibility similar to that of the epithelial CTAC line (57.8%). The K1-cell line exhibited less cytotoxic activity (41%) when incubated for 14 h, but showed results comparable to the K6-cell line, when the incubation time was reduced to 8 h.

Animals↗
PubMed1994

Structural organization of the porcine and human genes coding for a Leydig cell-specific insulin-like peptide (LEY I-L) and chromosomal localization of the human gene (INSL3).

Leydig insulin-like protein (LEY I-L) is a member of the insulin-like hormone superfamily. The LEY I-L gene (designated INSL3) is expressed exclusively in prenatal and postnatal Leydig cells. We report here the cloning and nucleotide sequence of porcine and human LEY I-L genes including the 5' regions. Both genes consist of two exons and one intron. The organization of the LEY I-L gene is similar to that of insulin and relaxin. The transcription start site in the porcine and human LEY I-L gene is localized 13 and 14 bp upstream of the translation start site, respectively. Alignment of the 5' flanking regions of both genes reveals that the first 107 nucleotides upstream of the transcription start site exhibit an overall sequence similarity of 80%. This conserved region contains a consensus TATAA box, a CAAT-like element (GAAT), and a consensus SP1 sequence (GGGCGG) at equivalent positions in both genes and therefore may play a role in regulation of expression of the LEY I-L gene. The porcine and human genome contains a single copy of the LEY I-L gene. By in situ hybridization, the human gene was assigned to bands p13.2-p12 of the short arm of chromosome 19.

Amino Acid Sequence↗
PubMed1994

A human cDNA coding for the Leydig insulin-like peptide (Ley I-L).

cDNA clones for the human Leydig insulin-like peptide (Ley I-L) have been isolated and characterized. The nucleotide sequence of the 743-bp cDNA includes an incomplete 7-bp 5'-noncoding region, an open reading frame of 393 bp, and a 343-bp 3'-noncoding region. By primer extension analysis, the transcription start site was determined as being 14-bp upstream of the translation start site. The underlying gene is expressed in the testis but not in other organs. From the cDNA sequence, it can be deduced that the Ley I-L protein is synthesized as a 131-amino-acid (aa) preproprotein and that it contains a 24-aa signal peptide. Comparison of the pro Ley I-L protein with members of the insulin-like hormone superfamily predicts that the biologically active hormone, after proteolytic processing of the C peptide, consists of a 31-aa long B chain and a 26-aa long A chain, and that it has a molecular weight of 6.25 kDa.

Amino Acid Sequence↗
PubMed1993

Cloning of a cDNA for a novel insulin-like peptide of the testicular Leydig cells.

We have isolated complementary DNA clones coding for a novel member of the insulin-like hormone super-family from a boar testis cDNA library. Northern blot analysis and in situ hybridization revealed that the gene is expressed exclusively in prenatal and postnatal Leydig cells. We have tentatively proposed the name Leydig insulin-like (Ley I-L) for the gene and its encoded protein. The Leydig insulin-like protein is synthesized as a 131-amino acid preproprotein, which contains a 24-amino acid signal peptide. Comparison of the deduced amino acid sequence of pro-Leydig insulin-like protein with members of the insulin-like hormone superfamily predicts that the biologically active protein, after proteolytic processing of the C-peptide, consists of a 32-residue-long B-chain and a 26-residue-long A-chain and has a molecular size of 6.25 kDa.

Amino Acid Sequence↗
PubMed1993

Endocardial pacing, cardioversion and defibrillation using a braided endocardial lead system.

The clinical efficacy and safety of a second-generation braided endocardial pacing, cardioversion and defibrillation lead system was evaluated in 25 patients with ventricular tachycardia (VT) or ventricular fibrillation (VF). The lead system consisted of two 8Fr active fixation endocardial leads each with pacing and defibrillation electrodes and a thoracic patch electrode. Monophasic and biphasic shocks were delivered using a triple-electrode configuration with a right ventricular common cathode and right atrial and thoracic patch anodes. VT and VF were electrically induced. Rapid VT (rate > or = 180 beats/min) and VF were initially terminated by 20 J (550 V) shocks and slow VT (rate < 180 beats/min) by 10 J (400 V) shocks. One hundred fourteen episodes (rapid VT/VF 73, slow VT 41) were treated with 128 shocks (monophasic 80, biphasic 48). Mean ventricular pacing threshold was 0.7 +/- 0.5 ms before and 0.9 +/- 0.5 ms after endocardial shock delivery (p > 0.2). Mean ventricular electrogram amplitude in sinus rhythm was 11.9 +/- 5.7 mV before and 11.4 +/- 5.1 mV after shock delivery (p > 0.2). Simultaneous monophasic endocardial shocks terminated 53% of VF episodes at < or = 20 J. Simultaneous biphasic shocks terminated 94% of all VF episodes at < or = 20 J (p < 0.03). Efficacy of > or = 10 J shocks for rapid VT/VF was greater for biphasic (92%) versus monophasic (74%) shocks (p < 0.05) at lower average shock energy (15 +/- 7 J vs 19 +/- 7 J, respectively, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Prospective comparison of biphasic and monophasic shocks for implantable cardioverter-defibrillators using endocardial leads.

Bidirectional shocks using 2 current pathways have been used in endocardial lead systems for implantable cardioverter-defibrillators, but the optimal shock waveform for endocardial defibrillation is unknown. The clinical efficacy and electrical characteristics of bidirectional monophasic and biphasic shocks for endocardial cardioversion-defibrillation of fast monomorphic or polymorphic ventricular tachycardia (VT), or ventricular fibrillation (VF) were evaluated. Thirty-three patients (mean age 60 +/- 12 years, and mean left ventricular ejection fraction 34 +/- 13%) were studied. Defibrillation catheter electrodes were located in the right ventricular apex and superior vena cava/right atrial junction. A triple-electrode configuration including the 2 catheter electrodes and a left thoracic patch was used to deliver bidirectional shocks from the right ventricular cathode to an atrial anode (pathway 1) and the thoracic patch (pathway 2). The shock waveforms examined were sequential and simultaneous monophasic, and simultaneous biphasic. The efficacy of 580 V (20 J) shocks for fast monomorphic VT were comparable for the 3 waveforms (73% for sequential monophasic, 73% for simultaneous monophasic, and 100% for simultaneous biphasic). However, for polymorphic VT and VF, 580 V sequential monophasic shocks had a significantly lower efficacy (25%) than did simultaneous monophasic (75%; p = 0.01) or biphasic (89%; p less than 0.001) shocks. Single-shock defibrillation thresholds with simultaneous biphasic shocks were significantly lower (9 +/- 5 J) than were those with simultaneous monophasic shocks (15 +/- 4 J; p less than 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Electric Countershock↗
PubMed1992

Germ cell-specific expression of a proacrosin-CAT fusion gene in transgenic mouse testis.

Acrosin is a serine proteinase located in a zymogen form, proacrosin in the acrosome of the sperm. It is released as a consequence of the acrosome reaction and is believed to be the most important enzyme in the fertilization process. In the mouse, the proacrosin gene is transcribed premeiotically in spermatocytes, but protein biosynthesis starts in haploid spermatids and is restricted to the emerging acrosome. Four lines of transgenic mice harboring 2.3 kb of 5' untranslated region of the rat proacrosin gene fused to the CAT-reporter gene were generated by microinjection of fertilized eggs. The chimeric gene was found to be present in 10-100 copies per genome in the different strains. The 5' untranslated region of rat proacrosin gene could properly direct CAT-gene expression to spermatocytes and CAT-mRNA translation to round spermatids as it is known for mouse proacrosin gene. However, CAT protein is not restricted to the acrosome; rather, it is distributed in the spermatid cytoplasm. This could be due to the lack of DNA sequences for a hydrophobic leader peptide that have been found in all mammalian proacrosins studied until now but that was not present in transgene. It can be concluded from our results that cis-acting sequences required for tissue specific proacrosin expression reside on a 2.3-kb restriction fragment and are conserved in the proacrosin genes of mouse and rat.

Acrosin↗
PubMed1992

Spontaneous chromomycosis in the marine toad (Bufo marinus).

Post-mortem examinations were performed on two marine toads, one animal showing neurological disorders and the other multifocal dermatitis. In one case, lesions consisted of a severe granulomatous encephalomyelitis and in the other of multiple granulomas in the nasal cavity, lungs, heart, bone marrow, ovaries and skin. Histologically, the lesions revealed varying amounts of dark brown fungal elements, predominantly sclerotic bodies indicative of a mycotic infection due to a pigmented fungus.

Animals↗
PubMed1990

[Recurring oral aphthae, genital ulcers, erythema nodosum, arthralgias].

A 37-year-old Turkish patient suffered from recurrent oral aphthosis, genital ulcers, skin lesions and inflammatory eye disease. Because of typical history, physical findings and absence of laboratory abnormalities Morbus Behçet was diagnosed. Under treatment with prednisone and azathioprine his symptoms disappeared and there was no recurrence of Behçet disease for three months.

Adult↗
PubMed1989

Paleoenvironmental distribution of microfossils and stromatolites in the Upper Proterozoic Backlundtoppen Formation, Spitsbergen.

The Upper Proterozoic (ca. 700-800 Ma old) Backlundtoppen Formation, northeastern Spitsbergen, preserves an abundant and varied record of ancient microbial life. Five distinctive microfossil assemblages occur in five equally distinct sedimentary settings; differences among the assemblages appear to reflect original ecological heterogeneity, although taphonomic circumstance may contribute to some distinctions. Microfossil assemblages occur in: oncolites, oolites, and pisolites; stratiform stromatolites and associated intraclastic rudites; partially silicified micrites; and siltites interbedded with quartz arenites. Individual assemblages contain one to eight differentiable taxa; a minimum of 17 distinct populations is present in the formation as a whole. Additional microbial community diversity an be inferred from the presence of domal, columnar, pseudocolumnar, and coniform stromatolites, none of which contains microfossils. On the basis of macrostructure, four stromatolite types appear to be present, but only three distinct mat-building communities can be inferred from microstructural features. Eohyella elongata n. sp., a euendolithic cyanobacterium found in silicified pisolites, is described as new.

Animals↗
PubMed1987

Susceptibility of chicken blood lymphoblasts and monocytes to infectious bursal disease virus (IBDV).

PHA-M stimulated lymphoblasts obtained from peripheral blood and separated from small lymphocytes by X 1 g velocity sedimentation, unstimulated blood lymphocytes, monocytes and cells isolated from the bursa of Fabricius of chickens, were infected in vitro by the pathogenic strain CU-1 of infectious bursal disease virus (IBDV). Six hours after infection 32.5 per cent of the bursal cells reacted immunocytologically with IBDV antiserum and had high infectivity titers in plaque assays. Separated lymphoblasts showed a marked lower degree of virus replication and only 2.5 per cent reacted positively when studied by immunocytology, while monocytes ranged between these two cell types with regard to both the degree of virus replication and the positive reaction with IBDV antiserum. Small lymphocytes, however, were found to be totally resistant to IBDV infection. When studied by electron microscopy, virus particles arranged in a crystalloid pattern could only be detected in bursal cells. The results of this study indicate that proliferating lymphoid cells at a certain stage of cellular differentiation are the target cells for IBDV, and that in infected chickens monocytes may play a role in the spreading of the virus.

Animals↗
PubMed1986

Monoclonal antibodies directed towards the two major cell populations in the bursa of Fabricius of the chicken.

Two mouse monoclonal IgM antibodies, B.1 and B.2, have been produced using the mouse myeloma cell line Sp2/0-Ag 14 and spleen cells from mice immunized with chicken bursa cells. The binding of the monoclonal antibodies to cells in suspension or tissue sections was demonstrated by means of the unlabeled peroxidase-antiperoxidase method. B.1 recognizes 61% of the bursa cells, 10-14% of the cells of spleen and of the peripheral mononuclear blood leukocytes and 1% of the thymus cells. The B.1+ cells are regarded as B cells. Their location in tissue sections corresponds with the known B-dependent areas of lymphoid organs. Competitive binding and double marker experiments proved that the B.1 antigen is distinct from surface immunoglobulin (Ig). In the bursa all B.1+ cells are also Ig+, whereas in the thymus, spleen and blood only about 90% of the B.1+ cells show this conformity. B.2 mainly recognizes so called reticular epithelial and reticular cells of the bursa (36%), thymus (20%) and spleen (13%). The B.2+ cells represent the second major cell population of the bursa.

Animals↗