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Biomedical subjects

L Wagner

Publications and source records attributed to L Wagner.

At least 19 recordsLinked to original sources
PubMed1997

Expression of the Zn finger gene, EVI-1, in acute promyelocytic leukemia.

The EVI-1 gene encodes a Zn finger, DNA binding protein previously detected in some acute myelogenous leukemias (AML) and myelodysplasias (MDS), but not in normal marrow or cord blood cells. Experimental studies suggest EVI-1 blocks cellular differentiation by binding to GATA-1 or other specific DNA sequences controlling gene expression, and may be involved in the pathogenesis of some AMLs. To further define potential roles for EVI-1 in leukemia pathogenesis, we studied its regulation in acute promyelocytic leukemias (APL). Seven of 11 APL cases expressed EVI-1 RNA detected by RNA PCR at diagnosis, and expression was detected in two additional cases after treatment with all-trans retinoic acid (ATRA). Two of four cases studied at relapse also expressed EVI-1 RNA. To investigate regulation of EVI-1 expression in APL, we examined its expression in the NB4 APL cell line. NB4 cells did not express EVI-1 under basal conditions, but expressed EVI-1 after ATRA-induced differentiation. When NB4 cells were exposed to ATRA and transferred to cultures with N,N'-hexamethylene-bis-acetamide (HMBA), differentiation occurred but EVI-1 RNA was not detected, indicating that EVI-1 expression was not required for terminal, NB4 differentiation. ATRA-resistant NB4 cells were obtained by continuous culture in gradually increasing concentrations of ATRA. These cells did not express markers of differentiation but continued to express EVI-1 for several weeks even after ATRA withdrawal. To assess whether expression of the APL PML-RAR alpha fusion gene alone was sufficient for ATRA induction of EVI-1, the PML-RAR alpha gene cDNA was expressed in U937 histiocytic lymphoma cells. ATRA treatment of PML-RAR alpha-transfected or control U937 cells did not induce EVI-1 expression. In conclusion, this study demonstrates the EVI-1 gene is consistently expressed in APL cells either constitutively or after ATRA treatment. ATRA represents the first biologically active agent shown to specifically regulate EVI-1 expression in blood cells. In contrast to previous studies in AML and MDS, the pattern of EVI-1 expression suggests it may facilitate rather than inhibit myeloid differentiation during ATRA treatment. However, effects of EVI-1 expression are likely to be complex, and expression in ATRA-resistant APL cells may indicate multiple roles for this gene.

Acetamides↗
PubMed1996

Haptoglobin phenotyping by newly developed monoclonal antibodies. Demonstration of haptoglobin uptake into peripheral blood neutrophils and monocytes.

We have generated two IgG murine mAbs that recognize native human haptoglobin (Hp). These mAbs, 3A8 and 4B2, efficiently bind to the Hp complex regardless of the serum donor's phenotype. The specificity of mAb 3A8 was confirmed by immunoaffinity purification of 3A8-binding material from human serum and subsequent N-terminal amino acid sequencing of the invariant 40-kDa chain. mAb 3A8 and 4B2 were also reactive with cell-associated Hp when studied by immunocytochemistry. When human peripheral blood leukocytes were tested, 90% of the granulocytes and a lesser (and variable) fraction of monocytes displayed an intense intracytoplasmatic granular staining. This was confirmed by flow cytometric analysis of permeabilized leukocytes and by demonstrating the presence of Hp (of the expected Hp serum phenotype) in extracts of washed granulocytes by immunoblotting. Leukocytes obtained from a Hp phenotype 2-2 donor, incubated in culture medium supplemented with 10% serum from a donor possessing the Hp 1-1 phenotype, contained both Hp phenotypes when analyzed by immunoblotting after a 6-h incubation period. In addition, Hp was actively exocytosed by granulocytes following their exposure to Candida albicans. These observations suggest that exogenous Hp is concentrated within granulocytes and not synthesized de novo and is, in turn, exocytosed following neutrophil activation. Northern blotting analysis is consistent with the lack of haptoglobin gene transcription in granulocytes. These findings together with the earlier observations that Hp modulates granulocyte activity suggest that Hp levels may be enhanced locally at sites of inflammation to modulate granulocyte activity.

Amino Acid Sequence↗
PubMed1996

Long-term bladder dysfunction in boys with posterior urethral valves.

We report a series of 60 children operated on for posterior urethral valve (PUV) before the age of 5 years and followed up for 10 years. This work aims to study the vesico-sphincteric sequelae of this malformation. 38 patients showed early urinary incontinence post-operatively. Of them, 20 were re-evaluated 10 years later by pelvic ultrasonography, pressure flow studies combined with EMG and assessment of renal function. 8 patients refused to undergo these investigations and 10 were lost to follow-up. Of the 28 evaluable patients, 22 are currently continent and a complete urodynamic study was performed for the 6 (10%) incontinent patients. Of them, 3 showed uninhibited detrusor contractions. The vesical compliance was frequently within the normal limits. No case of detrusor-sphincteric dyssynergy or urethral hypotony was found. 2 were successfully treated by oxybutinin and biofeedback reeducation, 2 were partially improved but their prostates are still in growth and the possibility of implanting an artificial sphincter was discussed in the remaining 2. The urodynamic evaluation of those patients in the long-term is encouraging.

Child↗
PubMed1996

Do intestinal hyperpermeability and the related food antigens play a role in the progression of IgA nephropathy? I. Study of intestinal permeability.

Intestinal permeability was investigated by using 51Cr-EDTA as a probe molecule in 29 patients with immunoglobulin A nephropathy (IgA NP) and 20 healthy controls in 1990. Intestinal permeability was significantly higher in the IgA NP patients than in the controls (IgA NP, 3.86 +/- 0.29%; controls, 2.72 +/- 0.23%, p < 0.005). There was a significant relation between the manifestations of the disease (proteinuria and/or microhematuria) and the increased intestinal permeability (p < 0.05). By 1994, after an interval of 4 years, average intestinal permeability in the 21 patients available for study had not changed (3.80 +/- 0.36 vs. 4.57 +/- 0.63%) and was significantly higher than in the controls (p < 0.02). In patients with elevated serum IgA levels (serum IgA > 3.2 g/l; n = 15) there was a significant correlation between serum IgA levels and the degree of intestinal permeability (p < 0.02). During the 4-year period, the patients' kidney function deteriorated (n = 25; creatinine clearance in 1990, 92.4 +/- 6.1 ml/min; in 1994, 73.9 +/- 7.6 ml/min; p < 0.0002), the deterioration being greater in patients with increased intestinal permeability. There was no relation between the histologic grade of the biopsy specimen, hypertension and intestinal permeability. These data collected over a 4-year period suggest that in IgA NP increased intestinal permeability may play a role in the pathogenesis of the disease and adversely influence its progression.

Adult↗
PubMed1995

Modulation by high glucose of adhesion molecule expression in cultured endothelial cells.

We evaluated the influence of high ambient glucose on cellular expression of adhesion molecules, known to mediate endothelial interaction of leucocytes and monocytes. Paired cultures of individual isolates of human umbilical vein endothelial cells (HUVECs) were studied by fluorescence activated cell sorter analysis after exposure to 30 vs 5 mmol/l glucose. Incubation of HUVECs for 24h in 30 mmol/l glucose increased ICAM-1 (intercellular adhesion molecule-1; 116.4 +/- 16.9% of control, p < or = 0.05), but not PECAM (platelet endothelial cell adhesion molecule) expression, compared to cultures kept in 5 mmol/l glucose. Long-term exposure (13 +/- 1 days) of HUVECs to 30 mmol/l glucose increased expression of ICAM-1 to 122.5 +/- 32.2% (p < 0.002) and reduced that of PECAM to 86.9 +/- 21.3% vs the respective control culture in 5 mmol/l glucose (p < 0.02). Stimulation of confluent HUVECs, kept in 30 vs 5 mmol/l glucose for 13 +/- 1 days, with 20 U/ml interleukin-1 for 24 h (ICAM-1) and 4 h (endothelial leukocyte adhesion molecule 1) resulted in reduced ICAM-1 (84.8 +/- 27.0%, p < 0.05) and endothelial leukocyte adhesion molecule-1 (87.6 +/- 22.4%, p < 0.05) expression vs control cells, while that of PECAM (t:24 h) and vascular cell adhesion molecule-1 (t: 16 h) remained unchanged. In conclusion, it appears that differences in expression of adhesion molecules on HUVECs in response to high glucose reflects endothelial glucose toxicity, which may also induce endothelial dysfunction in diabetes.

Cell Adhesion Molecules↗
PubMed1995

Estimating rates of chronic fatigue syndrome from a community-based sample: a pilot study.

Most of the Chronic Fatigue Syndrome (CFS) epidemiological studies have relied on physicians who refer patients having at least six months of chronic fatigue and other symptoms. However, there are a number of potential problems when using this method to derive prevalence statistics. For example, some individuals with CFS might not have the economic resources to access medical care. Other individuals with CFS might be reluctant to use medical personnel, particularly if they have encountered physicians skeptical of the authenticity of their illness. In addition, physicians that are skeptical of the existence of CFS might not identify cases. In the present pilot study, a random community sample (N = 1,031) was interviewed by telephone in order to identify and comprehensively evaluate individuals with symptoms of CFS and those who self-report having CFS. Different definitions of CFS were employed, and higher rates (0.2%) of CFS were found than in previous studies. Methodological benefits in using more rigorous epidemiological methods when estimating CFS prevalence rates are discussed.

Adolescent↗
PubMed1995

Inhibition of cytotoxic T-lymphocyte-triggered apoptosis by target cell surface-coupled aprotinin.

A variety of recent investigations have implicated granzymes A and/or B in the target cell nuclear injury which accompanies cytotoxic T-lymphocyte-mediated cytolysis. Since soluble antiproteases have had limited efficacy in inhibiting CTL-mediated lysis, we developed a method to couple aprotinin, a peptide inhibitor of serine proteases, to the surface of target cells. Aprotinin modified by N-succinimidyl 3-(2-pyridyldithio)propionate retained trypsin-inhibitory activity, and target cells modified with aprotinin had demonstrable cell surface trypsin-inhibitory activity. Flow cytometry demonstrated that aprotinin was detectable on the target cell surface but underwent modulation at a rather rapid rate. When radiolabeled, aprotinin-coupled target cells were studied in 1-2 hr CTL assays, 51Cr release was little affected, but 125IUdR release was reduced up to 75% compared to controls. Corresponding apoptosis analysed by agarose gel electrophoresis and direct cytologic visualization was similarly reduced. Thus, aprotinin bound to the surface of target cells selectively protected target cells against CTL-mediated nuclear injury, and may serve as a model for the development of novel inhibitors of CTL-mediated lysis.

Animals↗
PubMed1995

An arrayed library enriched in hncDNA corresponding to transcribed sequences of human chromosome 19: preparation and analysis.

A simple technique for preparation of libraries of the human chromosome specific transcribed sequences is developed. It uses hnRNA from human-rodent hybrid cell lines containing particular human chromosomes or their fragments and includes three stages: (i) reverse transcription of the hnRNA with Alu-specific primers directing the transcription beyond the Alu-repeats to flanking non-repetitive sequences of the chromosome; (ii) nested primer PCR strategy with specifically designed primers; (iii) direct selective cloning of the second-stage nested primer PCR products. An arrayed hncDNA library was prepared from a hybrid cell line containing chromosome 19 and fragments of 22 and X chromosomes. The library contains around 98% of human-specific transcribed sequences. Sequences of 52 human-specific, according to PCR analysis, clones differed from each other and had no close analogs in the EMBL Data Bank. Of 17 clones assigned to certain human chromosomes, 9 belonged to chromosome 19, 5 to chromosome 22 and 3 to chromosome X. Some of the human specific clones contained repetitive elements scattered over different human chromosomes. Clones from hncDNA libraries are useful as STSs/ESTs, as probes for detecting full-size genes in genomic libraries, for RFLP analysis and for identification of chromosome specific cDNAs.

Animals↗
PubMed1995

Pediatrician's communication style: relationship to parent's perceptions and behaviors.

Investigated physician-parent communication styles and the effects of concordance between parent's desired communication styles and the communication style exhibited by physicians. Subjects were 107 parents of children scheduled for an appointment with a pediatrician at a general medical clinic. Parents and physicians completed rating forms indicating the degree to which parents desired each of four communication styles (information giving, interpersonal sensitivity, partnership, and directing one's own treatment). Parents and physicians also rated the degree to which they believed the physician exhibited each of these four styles. Follow-up interviews with parents assessed the level of satisfaction with the visit, perception that parent's concerns had been addressed, and subsequent telephone calls to the physician. Results indicated that physicians underestimated the degree of interaction desired by the parents. Parent desires for particular communication styles were not predicted by characteristics of the parents. Interaction variables predicted parent perceptions and subsequent need for contact with the physician.

Adolescent↗
PubMed1995

BLT-esterase in infectious mononucleosis.

Peripheral blood lymphocytes of three patients suffering from infectious mononucleosis due to Epstein-Barr virus (EBV) infection were analysed for BLT-esterase expression in peripheral blood lymphocytes by a well established cytochemical staining method. During the acute phase of disease with presence of clinical symptoms a very high level of up to 90% BLT-esterase-expressing lymphocytes were detected. The increased percentage of lymphocytes expressing BLT-esterase coincided with the time of greatest symptoms and the peak elevation of hepatocellular enzymes. The still moderately elevated level only gradually decreased to normal during the further recovery period of 2 months during which the patients described episodes of weakness. Peripheral blood lymphocyte phenotype analysis revealed a marked CD8 lymphocytosis, a CD4/CD8 ratio of about 0.2, low number of CD19+ B cells, and a high level of DR+ CD3+ lymphocytes. Reduction of BLT esterase expression during the recovery period coincided with reduction of CD8+ DR+ lymphocytes. By a combination of BLT-esterase staining with immunocytochemical phenotype analysis, 95% of CD8+ lymphocytes were found to be BLT-esterase-positive. BLT-esterase might be involved in the immunodefence against EBV in infectious mononucleosis by inducing apoptosis in EBV-transformed B cells.

Adolescent↗
PubMed1995

High-glucose--triggered apoptosis in cultured endothelial cells.

High ambient glucose concentration, linked to vascular complications in diabetes in vivo, modulates mRNA expression of fibronectin, collagen, tissue-type plasminogen activator, and plasminogen activator inhibitor and induces delayed replication and excess cell death in cultured vascular endothelial cells. To determine the role of high ambient glucose (30 mmol/l) in apoptosis, paired cultures of individual isolates of human umbilical vein endothelial cells (HUVECs) were exposed to both high (30 mmol/l) and low (5 mmol/l) concentrations of glucose for short-term (24, 48, and 72 h) and long-term (13 +/- 1 days) experiments. Incubation of HUVECs with high glucose for > 48 h increased DNA fragmentation (13.7 +/- 6.5% of total DNA, mean +/- SD) versus cultures kept in 5 mmol/l glucose (10.9 +/- 5.6%, P < 0.005), as measured by [3H]thymidine assays. Data were confirmed by apoptosis-specific fluorescence-activated cell sorter analysis of confluent HUVEC cultures, which displayed after long-term exposure to 30 mmol/l glucose a 1.5-fold higher prevalence of apoptosis than control cultures exposed to 5 mmol/l glucose (P < 0.005). In contrast, no increase in DNA fragmentation in response to 30 mmol/l glucose was seen for standardized cell lines (K 562, P 815, YT) and fibroblasts. Expression of clusterin mRNA, originally reported to be a molecular marker of apoptosis, was only slightly affected by short-term (24-h) high-glucose exposure but was significantly reduced after long-term incubation in 30 mmol/l glucose (82.2 +/- 13.8% of control) versus 5 mmol/l glucose, which questions the role of clusterin gene expression as a marker of apoptosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Apoptosis↗
PubMed1994

Treatment of a patient with malignant mesothelioma with interferon-alpha 2 based on in vitro sensitivity tests.

The case of a 70-year-old patient with an epithelial mesothelioma is presented. The patient suffered from dyspnea due to a right-sided recurrent hemorrhagic effusion. Cytological analysis of the effusion revealed marked lymphocytosis and tumor cells, some of them multinucleated with prominent nucleoli. Open lung biopsy revealed nodular thickening of the diaphragmatic, visceral, and parietal pleura; histological examination of biopsies detected intravascular growth of tumor cells. Immunocytochemical characterization of cultured tumor cells and the biopsy specimens showed positive staining to vimentin and cytokeratin, but negative reaction with antibodies against epithelial membrane associated antigen, leukocyte common antigen, van Willebrand factor, and neurofilament. Hence, the tumor was classified as malignant mesothelioma. In vitro, interferon-alpha 2 produced a dose-dependent inhibition of proliferation in the cultured mesothelioma cells. Two weeks after initiation of interferon-alpha 2 treatment the patient improved and the pleural effusion vanished.

Aged↗
PubMed1994

Difference between splenic volume measured at necropsy and that measured in vivo by radionuclide tomography.

Reference values for splenic volume used in this study are based on necropsy measurements made in 1970. Because the volumes (measured by radionuclide tomography) seemed to be consistently greater than the necropsy values, the splenic volume in 35 healthy male volunteers ranging in age from 18-30 years (median age, 21 years) was studied. Their mean (SD) splenic volume was 281 (73) ml compared with 138 (34) ml in the reference group. The mean splenic volume in healthy volunteers seems to be significantly greater than in cadavers, and these results suggest that reference range for splenic volume in vivo should be revised.

Adult↗
PubMed1994

Drug consumption among elderly--a four-year study.

The aim of the study was to analyse whether a radical structural change in the provision of care for the elderly, including changes in the pattern of drug administration, might influence drug consumption among residents in a Danish nursing home. A comprehensive reorganization of the care of the residents took place in the mid-1980s. The general approach to self-care, with greater autonomy and influence over one's own life was also disseminated to the area of administration of medication. Previously the nurses had been responsible for this area but a new model was introduced in 1986 in principle permitting all residents to be in charge of their own medication. The study was carried out as a survey over four consecutive years from 1985 to 1988, and included 48 residents in a nursing home of whom 24 participated in all four surveys. A minimum of drugs were administered immediately after the change in regimen. Although a slight increase was recorded in the subsequent years, the level of drug consumption did not reach pre-intervention levels. The total number of regularly administered drugs per day in survey 1 averaged 4.6 drugs/person. In survey 2 this had decreased to average 3.6 (p < 0.05).

Aged↗
PubMed1993

In vivo and in vitro primed lymphocytes. Correlation of cytochemically detected BLT-specific lymphoid serine protease with cytotoxic activity.

We describe the validation of a cytochemical method to detect a cytolytic cell-specific lymphoid serine protease which can be upregulated during viral infection and allogeneic stimulation. The cytolytic cell specificity was ascertained by demonstrating a high correlation between BLT substrate-specific serine protease (SP) activity and cytotoxicity of in vivo and in vitro stimulated lymphocytes. The presence of SP in peripheral blood lymphocytes was compared with their capacity to kill K562 targets in a lectin-dependent cytotoxicity assay. The correlation coefficient was 0.92 and 0.93 at E:T ratios 10:1 and 20:1 respectively. In allogeneic mixed lymphocyte cultures an increase of SP activity in effector lymphocytes was paralleled by an augmentation of cytotoxic capacity towards stimulator target cells. SP+ granules showed intracellular polarization to the effector/target cell interface during conjugate formation. These results together with previous studies suggest that this method provides a sensitive assay which predicts the cytolytic potential present in a lymphocyte population.

CD4-Positive T-Lymphocytes↗