PubMed Health⌕ Search

Biomedical subjects

M Burger

Publications and source records attributed to M Burger.

At least 19 recordsLinked to original sources
PubMed1992

[A case of adult Gaucher disease].

The authors describe a case of an adult patient having Gaucher's disease, who had hepatosplenomegaly and pancytopenia. The diagnosis was established by the low level of leukocyte beta-glucosidase and by histology of bone marrow, liver and spleen. The patient had no bone pain, but MRI described characteristic lesions of the femur. Serum acid phosphatase was characteristically elevated. The hypersplenism was reduced after splenectomy. The patient has a daughter with central nervous system dysfunction. Her chromosome examination is normal, but she has lower leukocyte beta-glucosidase activity too. She may have a Gaucher's disease of type II, the acute neuropathic form.

Adult↗
PubMed1992

Soluble interleukin-2 receptors inhibit interleukin 2-dependent proliferation and cytotoxicity: explanation for diminished natural killer cell activity in cutaneous T-cell lymphomas in vivo?

In patients with cutaneous T-cell lymphomas (CTCL), soluble interleukin-2 receptor serum levels (sIL-2R) were determined by ELISA technique, and natural killer cell (NK) activity, by a 4-h chromium-51 release assay. Decrease of NK activity correlated with the augmentation of serum sIL-2R. After a 4-d stimulation with interleukin 2 CTCL patients' peripheral mononuclear cells (PMC) showed an increase of cytotoxic activity similar to that in healthy donors' PMC. Normal donors' PMC demonstrated a diminished IL-2-induced cytotoxic activity in 25% CTCL serum (sIL-2R of 3000, 7330, and 10700 U/ml, respectively) compared to control serum (sIL-2R of 400, 340, and 420 U/ml, respectively). IL-2-dependent proliferation of 2-d phytohemagglutinin (PHA) blasts was lower in CTCL serum than in control serum. sIL-2R was enriched from one CTCL patient's serum by IL-2 affinity chromatography. Transfection of the Tac gene into NIH/3T3 fibroblasts resulted in the production of a recombinant sIL-2R. The presence of enriched native or recombinant sIL-2R inhibited interleukin-2-dependent generation of cytotoxic activity and PHA blast proliferation. We suggest that elevated sIL-2R levels account for diminished NK activity by neutralizing interleukin 2 in CTCL patients.

Cytotoxicity, Immunologic↗
PubMed1989

Mitogen-responsive S6 kinase.

Many cell lines respond to mitogenic stimuli (serum, growth factors) with rapid phosphorylation of the ribosomal protein S6 at several serine sites. We have tried to identify the protein kinase(s) mediating this effect of growth stimuli. Examining post-DEAE chromatography fractions of S49 kin- cell extracts, we could detect a highly active effector-independent S6 kinase with specificity for serine residues. The study was extended to the presumably homologous human enzyme, using HeLa S3 cells as model system. Activity yields increased up to sevenfold when exhausted HeLa cells were supplied with fresh medium plus serum. The enzyme uses ATP, not GTP, as cosubstrate, 40-S or 80-S (reassociated from subunits) ribosomal particles being substrate. The optimal K+ concentration, measured at 3 mM Mg2+, is 35 mM. Under optimized assay conditions S6 phosphorylation proceeded faster in vitro than it appeared to do in vivo. The apparent Mr of the enzyme, as estimated by gel filtration on Sephadex G-100, is 56,000 (determination in the presence of 200 mM KCl in 25 mM phosphate buffer). Tighter binding to DEAE-Sephacel and higher specificity for S6 distinguishes this enzyme from the following S6-phosphorylating protein kinases: protein kinase C, protease-activated kinase II, histone-4 phosphotransferase and an enzyme with the properties of casein kinase I. In published summaries of observations shown here and in a follow-up study with chick embryo fibroblasts, the enzyme(s) has been referred to as mitogen-responsive S6 kinase(s) [Martini, O. H. W. and Lawen, A. (1985) in Hormones and cell regulation (Dumont, J. E., Hamprecht, B. and Nunez, J., eds) vol. 9, pp. 411-412, Elsevier Company, North-Holland, Amsterdam; Lawen, A. and Martini, O. H. W. (1985) FEBS Lett. 185, 272-276].

Adenosine Triphosphate↗
PubMed1989

Insulin-induced S6 kinase activation in HeLa cells and its reversal by hyperthermic stress.

Insulin treatment of HeLa S3 cells activates an S6-phosphorylating protein kinase. Although this enzyme has chromatographic properties resembling those of described proteolytic fragments of other protein kinases, namely protein kinase C, protease-activated kinase II and histone-4 protein kinase, and although insulin has been proposed by others to cause S6 phosphorylation via proteolytic protein kinase activation, the insulin-induced increase in S6-kinase activity described here is probably not due to proteolysis. Rather, the activity indicates the existence, in HeLa cells, of an interconvertible S6 kinase, since the insulin-induced activity increase was rapidly reversed under hyperthermic stress, and since this effect of hyperthermia was itself reversible. The S6-kinase activities from serum- and from insulin-stimulated HeLa cells resemble each other closely and are likely to represent the same enzyme. The enzyme may therefore mediate both signals delivered by mitogens and the insulin signal. Analysed at an in vitro transfer of 1 mol phosphate/mol S6, this S6 kinase activity does not phosphorylate the (principal) S6 site recognized by the cAMP-dependent protein kinase.

Binding Sites↗
PubMed1989

Increased detection rate of human papillomavirus in cervical scrapes by the polymerase chain reaction as compared to modified FISH and southern-blot analysis.

Cervical scrapes from 80 women with a positive cytology result were tested for the presence of human papillomavirus (HPV) using the polymerase chain reaction (PCR) and compared to the results obtained with the modified filter in situ hybridisation (FISH) and the Southern-blot techniques. The sensitivity of the modified FISH and the Southern-blot was similar, and HPV was detected in 46% of the patients. The sensitivity of the PCR appeared to be higher, and HPV was detected in 70% of the patients. HPV-DNA could be detected in 46 of the 68 patients with mild dysplasia, in 6 of the 8 patients with severe dysplasia, and in all 4 patients with carcinoma in situ. In 18 patients (21%) more than one HPV type could be detected by the PCR. The control group consisted of 100 women involved in a triennial checkup programme, who had normal smear results and no history of cervical lesions. HPV was detected in 5% of the women by the PCR. The PCR technique detected HPV in a high proportion of the cervical scrapes from women with a positive cytology result. These results give further evidence for an important role of HPV in the pathogenesis of cervical cancer.

Biomarkers↗
PubMed1989

Acute immune hemolysis induced by a degradation product of amphotericin B.

We report here on an eight-year-old boy who first developed acute intravascular hemolysis following therapy with amphotericin B (AmB) and subsequently a delayed hemolytic transfusion reaction due to alloantibodies. Although there is as yet no evidence for metabolism of AmB in vivo, the hemolysis appeared to be the result of sensitization against a degradation product of the drug. The patient's serum contained a hemagglutinating IgM antibody that reacted with all red blood cells (RBC) tested in the presence of plasma obtained from patients receiving AmB (ex vivo antigen), but not in the presence of their urine, AmB itself, or with AmB-pretreated RBC. These findings indicate that the antibody was directed against a degradation product of AmB, presumably a trace metabolite, that has not yet been identified.

Acute Disease↗
PubMed1989

Stimulation of thymus cells by the calcium ionophore A23187 in the presence of LPS and 2-ME: on the mode of action of A23187 and 2-ME.

The stimulation of murine spleen and thymus cells by the calcium ionophore A23187 was studied using a serum-free culture technique. In cultures of spleen cells, rabbit IgG was capable of replacing A23187 in bringing about the stimulation of cells. Low concentrations of A23187 were inhibitory to proliferating B lymphocytes. In cultures of thymus cells a stimulating activity of A23187 was observed only if LPS was present in the medium.

Animals↗
PubMed1989

Triple-phase bone image abnormalities in Lyme arthritis.

Arthritis is a frequent manifestation of Lyme disease. Limited triple-phase Tc-99m MDP bone imaging of the wrists and hands with delayed whole-body images was performed in a patient with Lyme arthritis. This demonstrated abnormal joint uptake in the wrists and hands in all three phases, with increased activity seen in other affected joints on delayed whole-body images. These findings are nonspecific and have been previously described in a variety of rheumatologic conditions, but not in Lyme disease. Lyme disease should be considered in the differential diagnosis of articular and periarticular bone scan abnormalities.

Bone and Bones↗
PubMed1987

Interplay between extracellular -SH groups and Ca2+ in their mitogenic action on murine lymphocytes: the role of SiO2.

Murine spleen lymphocytes, cultured under serum-free conditions and stimulated with concanavalin A (Con A), showed an increased demand for supplemental concentrations of Ca2+ when 2-mercaptoethanol (2-ME) or L-cysteine were also present in the culture medium. The requirement for additional Ca2+ ions was particularly evident at high cell concentrations. The addition of SiO2 (Aerosil 200), in concentrations depending on the original level of Ca2+ in the culture medium, could substitute for the increased demand on calcium ions. This dependency of SiO2 effects on calcium levels in the medium was also evident when supraoptimal, i.e. inhibitory concentrations of silica were tested. Results of experiments with 45Ca suggest that silica particles may act as intercellular carriers of calcium. In contrast to spleen lymphocytes, Con A-stimulated thymus cells exhibited neither a need for an increase in the concentration of Ca2+ nor a dependency on the presence of 2-ME in the medium.

Animals↗
PubMed1986

Stimulation of proliferation of murine lymphocytes by the calcium ionophore A 23187 in the absence of serum: the requirement for thiols.

The proliferation of mouse spleen cells and T-lymphocytes, initiated by the calcium ionophore A 23187 was studied by a serum-free culture technique. In contrast to Con A, A 23187 was capable of stimulating cells only if 2-mercaptoethanol, cysteine and glutathione (reduced form), respectively, were present in the culture medium. In the absence of one of these compounds a stimulating activity of A 23187 was observed only with high concentrations of cells (i.e., 10(7)/ml). With glutathione present, the cells could be stimulated only at concentrations of A 23187 which were found to be suboptimal in cultures with 2-mercaptoethanol. Human serum, fetal calf serum and bovine serum albumin shifted the active and optimally stimulating concentrations of A 23187 to higher values. A similar effect was observed with sera- and Con A-treated cells. The effect of sera and albumin was paralleled by a protecting effect of cells against high concentrations of A 23187.

Animals↗
PubMed1979

An absolute requirement for 2-mercaptoethanol in the in vitro primary immune response in the absence of serum.

Using a serum-free medium, high recoveries of plaque-forming cells (PFCs) were obtained up to 5 days of incubation in the in vitro primary immune response. Under these conditions, the presence in the medium of 2-mercaptoethanol was an absolute requirement. In order to obtain maximal recoveries of PFCs, the antigen and 2-mercaptoethanol had to be present from the start of the culture, while the addition of fetuin could be delayed for 24 h without any loss of PFCs. The 2-mercaptoethanol could be replaced by (dialysed) human serum.

Animals↗
PubMed1977

A serum-free medium for the Mishell-Dutton system.

A serum-free medium which provides high recoveries of plaque-forming cells in the primary immune response to sheep erythrocytes is described. In this medium the serum was replaced by heated fetuin and by excess of nonessential amino acids. Glycopeptides, obtained by excessive pronase treatment of fetuin were partially capable of replacing the nonhydrolyzed fetuin.

Amino Acids↗
PubMed1977

Marked instability of character of cloned epithelial cells.

Cell lines derived from 7,12-dimethylbenzanthracene-induced rat mammary carcinomas show a marked drift in properties when cultured in vitro. The following characteristics alter progressively with the number of passages: cloning efficiency, requirement for hydrocortisone, requirement for fetal sera, growth response to conditioning factor(s) and ease of detachment from the culture vessel by trypsinization.

9,10-Dimethyl-1,2-benzanthracene↗