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Biomedical subjects

J Aumann

Publications and source records attributed to J Aumann.

12 recordsLinked to original sources
PubMed2002

Sensitive PCR method for the detection and real-time quantification of human cells in xenotransplantation systems.

The sensitive detection of human cells in immunodeficient rodents is a prerequisite for the monitoring of micrometastasis of solid tumours, dissemination of leukaemic cells, or engraftment of haematological cells. We developed a universally applicable polymerase chain reaction method for the detection of a human-specific 850-bp fragment of the alpha-satellite DNA on human chromosome 17. The method allows the detection of one human cell in 10(6) murine cells and could be established as both, a conventional DNA polymerase chain reaction-assay for routine screening, and a quantitative real-time polymerase chain reaction-assay using TaqMan-methodology. It was applied to the following xenotransplantation systems in SCID and NOD/SCID mice: (1) In a limiting dilution assay, cells of the MDA-MB 435 breast carcinoma were injected into the mammary fat pad of NOD/SCID mice. It could be shown that 10 cells mouse(-1) were sufficient to induce a positive polymerase chain reaction signal in liver and lung tissue 30 days after transplantation as an indicator for micrometastasis. At this time a palpable tumour was not yet detectable in the mammary fat pad region. (2) Cells of a newly established human acute lymphatic leukaemia were administered intraperitoneally to SCID mice. These cells apparently disseminated and were detectable as early as day 50 in the peripheral blood of living mice, while the leukaemia manifestation was delayed by day 140. (3) In a transplantation experiment using mature human lymphocytes we wanted to standardise conditions for a successful survival of these cells in NOD/SCID mice. It was established that at least 5 x 10(7) cells given intravenously were necessary and that the mice had to be conditioned by 2 Gy body irradiation to get positive polymerase chain reaction bands in several organs. (4) Engraftment studies with blood stem cells originating from cytapheresis samples of tumour patients or from cord blood were undertaken in NOD/SCID mice in order to define conditions of successful engraftment and to use this model for further optimisation strategies. The polymerase chain reaction method presented allowed a reliable prediction of positive engraftment and agreed well with the results of immunohistochemical or FACS analysis. All together, the polymerase chain reaction method developed allows a sensitive and reliable detection of low numbers of human cells in immunodeficient hosts. In combination with real-time (TaqMan) technique it allows an exact quantification of human cells. As this method can be performed with accessible material of living animals, follow up studies for the monitoring of therapeutic interventions are possible in which the survival time of mice as evaluation criteria can be omitted.

Animals↗
PubMed2001

Treatment of asthma by the inhaled corticosteroid ciclesonide given either in the morning or evening.

The study addressed the question whether the novel inhaled prodrug corticosteroid ciclesonide is equally effective when inhaled in the morning compared to the evening. For this purpose a double-blind, randomized, parallel group study was initiated in which 209 asthmatic patients (forced expiratory volume in one second = 50-90% predicted) inhaled either 200 microg ciclesonide in the morning or in the evening, for 8 weeks. Efficacy was assessed by means of spirometry as well as daily recordings of morning and evening peak expiratory flow (PEF), symptoms and use of rescue medication. The 24-h urinary cortisol excretion was measured to evaluate any effect on hypothalamic-pituitary-adrenol axis. Ciclesonide significantly improved asthma control. Morning and evening administration was shown to be equally effective for the different spirometry variables, evening PEF, symptoms, use of rescue medication and number of asthma exacerbations. Regarding morning PEF, the improvements after evening dosing were more prominent and equivalence of morning and evening administration could not be demonstrated. No relevant influence on cortisol excretion was found. Overall, the study indicates that ciclesonide can be given either in the morning or in the evening to meet the patients' preference and individual medical needs, although evening administration may lead to a more pronounced improvement in morning peak expiratory flow.

Administration, Inhalation↗
PubMed2001

Quantification of human cells in NOD/SCID mice by duplex real-time polymerase-chain reaction.

BACKGROUND AND OBJECTIVES: The aim of this study was the development of a fast and reliable polymerase chain reaction (PCR) assay which quantifies the proportion of human cells in immunodeficient chimeric mice, for example transplanted with human hematopoietic stem cells. DESIGN AND METHODS: We developed a TaqMan chemistry-based, real-time duplex PCR assay to quantify human and murine DNA in a single-tube reaction in parallel (HUmu PCR). Two independent sets of primers and exonuclease probes, located in the tumor necrosis factor-a gene of both species, were selected to amplify specifically human and murine genomic DNA. Serial dilutions of defined numbers of human cells in mouse cells served to construct calibration curves. The test was applied to NOD/SCID mice transplanted with CD34(+) cells isolated from human cord blood and compared to FACS analysis. RESULTS: Analysis of DNA from human cells diluted stepwise into a fixed number of murine cells - and vice versa - led to calibration curves with good correlation for human and murine cells (r(2)>0.99) with a detection limit of 2% human cells. Results obtained with the HUmu PCR paralleled those of FACS analysis. However, in contrast to FACS analysis, which requires fresh single cell suspensions, the HUmu PCR can be carried out on already stored samples, even from solid organs and, moreover, the quantity of material required for analysis is very low. INTERPRETATION AND CONCLUSIONS: The HUmu PCR presented here is the first real-time PCR assay for simultaneous quantification of human and murine cells. It is extremely fast, accurate and is an interesting alternative method for quantifying the proportion of human DNA in organs of chimeric mice.

Animals↗
PubMed2000

Donor stromal cells from human blood engraft in NOD/SCID mice.

Little is known about the presence, frequency, and in vivo proliferative potential of stromal cells within blood-derived hematopoietic transplants. In this study, nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice were injected with human CD34(+) peripheral blood cells (PBCs) or cord blood cells (CBCs, either enriched for CD34 or density-gradient separated mononuclear cells). Flow cytometric analysis 5 to 11 weeks after transplantation revealed the presence of a human lymphomyeloid hematopoiesis within the murine bone marrow. Immunohistochemical staining of bone marrow cell suspensions using human-specific antibodies showed human cells staining positive for human fibroblast markers, human von Willebrand factor (vWF) and human KDR (vascular endothelial growth factor receptor-2) in mice transplanted with CD34(+) PBCs or CBCs, with mean frequencies between 0.6% and 2.4%. In stromal layers of bone marrow cultures established from the mice, immunohistochemical staining using human-specific antibodies revealed flattened reticular cells or spindle-shaped cells staining positive with human-specific antifibroblast antibodies (mean frequency, 2.2%). Cell populations of more rounded cells stained positive with human-specific antibodies recognizing CD34 (1.5%), vWF (2.2%), and KDR (1.6%). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis and subsequent complementary DNA sequencing detected transcripts of human KDR (endothelial specific) and human proline hydroxylase-alpha (fibroblast specific) within the bone marrow and spleen of transplanted mice. Analysis of nontransplanted control mice yielded negative results in immunocytochemistry and RT-PCR. Cells expressing endothelial and fibroblast markers were also detected in the grafts before transplantation, and their numbers increased up to 3 log in vivo after transplantation. These results indicate that stromal progenitor cells are present in human cytokine-mobilized peripheral blood or cord blood that engraft in NOD/SCID mice. (Blood. 2000;96:3971-3978)

Animals↗
PubMed1998

Physico-chemical properties of the female sex pheromone of Heterodera schachtii (Nematoda: Heteroderidae).

Several physico-chemical properties of the female sex pheromone of the beet cyst nematode Heterodera schachtii were elucidated. At least one component of the pheromone can be extracted from aqueous solutions with diethyl ether. However, the pheromone has a higher solubility in water, as most of the pheromone activity remained in the water fraction. Ion exchange chromatography revealed that the pheromone or at least one of its components is positively charged, whereas another pheromone component may be negatively charged. Fractional distillation of pheromone extracts showed that it is, indeed, composed of at least two components. These components may interact additively rather than synergistically.

Animals↗
PubMed1996

Second primary lung cancer in Flanders: frequency, clinical presentation, treatment and prognosis.

Patient and tumour characteristics of 23 patients presenting with a second primary lung cancer were analysed and compared with 534 patients with radically resected stage 1 non-small cell lung cancer (NSCLC). None of these characteristics is associated with a higher occurrence rate for second primary lung cancer. Prognosis in the latter patients is significantly worse than after resection of a 'solitary' NSCLC: the median survival time (MST) after resection of the first tumour is 50 months; after diagnosis of the second tumour only 14 months. Surgically retreated patients have a prognosis that is similar to that after resection of a 'solitary' NSCLC. No separate independent prognostic factors responsible for this survival difference could be isolated. Squamous histology and central location are associated with a longer recurrence free survival time. We conclude that the occurrence of a second primary lung cancer can not be predicted based on patient or tumour characteristics and that only surgical retreatment offers a chance of long survival in these patients.

Adult↗
PubMed1993

Relationship between lung tissue and blood plasma concentrations of inhaled budesonide.

In 11 patients, in whom a lung lobe or whole lung was to be resected, a single dose of 1.6 mg inhaled budesonide was given pre-operatively. In 9 of them, concentrations of the drug in both lung tissue and blood plasma were measured. Budesonide concentrations in lung tissue, at least 90 min after dosage, were 2.1-8.9 nmol kg-1. Concentrations in blood plasma (0.27-1.1 nmol kg-1) were 1/8th of those in lung tissue.

Administration, Inhalation↗
PubMed1991

Panagrellus redivivus: failure to find evidence for the occurrence and biosynthesis of sialic acids.

The occurrence of sialic acids in the free-living nematode Panagrellus redivivus was studied by periodate oxidation/[3H]sodium borohydride reduction of about 10(7) nematodes. In parallel, the capability of sialic acid biosynthesis was examined by metabolic labeling of the same number of nematodes with N-[3H]acetylmannosamine. In both experiments, radioactivity was incorporated into the nematodes. Mild acid hydrolysis, however, did not release radioactively labeled sialic acids or derivatives as tested by radio thin-layer chromatography, suggesting that P. redivivus does not contain or synthesize sialic acids.

Animals↗
PubMed1988

Early emphysema. Ten years' evolution.

In this study, functional evolution over ten years was evaluated in 13 patients with early emphysema. The diagnosis was made on the basis of a decrease in single-breath DCO (55 +/- 14 percent predicted, mean +/- 1 SD), a loss of elastic recoil (CL,st = 0.76 +/- 0.25 L/cm H2O), and only minor airway obstruction (FEV1 = 87 +/- 13 percent predicted, Sgaw = 0.09 +/- 0.04 cm H2O-1.s-1), and compatible chest radiographs. During the ten years, there was a decrease in FEV1 of 0.89 +/- 0.40 L p less than 0.001), with a range of 0.20 to 1.55 L (which could not clearly be related to smoking habits or to initial lung function), a decrease in elastic recoil (p less than 0.05, with a decrease of Ptp, TLC by 6 +/- 7 cm H2O; p approximately equal to 0.05), an increase in TLC of 0.46 +/- 0.80 1 (p approximately equal to 0.05), and in RV/TLC of 9 +/- 3 percent (p less than 0.001). The resistance of the upstream segment (ratio Ptp/Vmax) increased slightly but generally remained within normal limits. In conclusion, patients with early emphysema resemble those with classic COPD, with a mean yearly decline in FEV1 similar to that in COPD.

Adult↗