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Biomedical subjects

J Bauer

Publications and source records attributed to J Bauer.

At least 739 records · Page 41Linked to original sources
PubMedDate not supplied

[Heart transplantation in infants--a new option].

Nowadays orthotopic heart transplantation is world wide accepted as a therapeutic concept in endstage congestive heart failure. Concerning infants, there are still major objections against this kind of therapy and especially in our country exists only very limited experience. Since march 1988 we have performed an orthotopic heart transplantation in 10 pediatric patients: 5 infants (2-16 years of age) with congestive cardiomyopathy, 1 newborn with endocardial fibroelastosis, 3 newborns with hypoplastic left heart syndrome, and finally 1 infant at the age of 2 years with AV-canal and hypoplastic left ventricle. Until now 6 infants survived and are all at home and in good clinical condition. There have been no signs for chronic rejection or graft atherosclerosis up till now. As demonstrated in the example of the newborn, in whom we performed the first successfully orthotopic heart transplantation in Germany, the clinical course and quality of life are superior to those after other palliative procedures in complex cardiac malformations.

Adolescent↗
PubMedDate not supplied

[Kinetics of myelopoietic regeneration and mobilization of CD34-positive cells within the scope of the NB90 Neuroblastoma Therapy Study].

Hematological and clinical data of 14 children with neuroblastoma treated according to the German neuroblastoma therapy study NB 90 were analyzed. Therapy included 4 or 8 intensive therapy elements N1 (Etoposide 125 mg/m2 day 1-4, Vindesine 3 mg/m2 day 1, Cisplatin 40 mg/m2 day 1-4) and N2 (Vincristine 1.5 mg/m2 day 1 + 8, Dacarbazine 200 mg/m2 day 1-5, Ifosfamide 1500 mg/ m2 day 1-5, Doxorubicin 30 mg/m2 day 6 + 7) in alternating order. The hematological recovery was studied after 86 therapy elements N1/N2. G-CSF had been given in 23 therapy courses, while no cytokine was administered in 63 therapy courses. Mobilization of CD34+ cells was studied in 13 therapy courses with G-CSF. Severe myelosuppression with an absolute neutrophil count < 500/microL was noted 2-4 weeks after each therapy element. The use of G-CSF did not prevent, but shortened neutropenia. There was no difference in the number of infections nor time delay of therapy between the courses with or without G-CSF. In 11 therapy courses G-CSF was started on the day following the last chemotherapy dose (N1: day 5; N2: day 9). In 12 therapy courses G-CSF was given delayed, starting day 12 after the initiation of therapy. Kinetics of granulocyte recovery was similar in the early or delayed application of G-CSF. Neutrophil recovery after the therapy element N1 was earlier and faster compared to that of therapy element N2. The more rapid rise of the neutrophils after the N1 element was accompanied by an effective mobilization of CD34+ cells. Taking into account the limitations of this retrospective study, the data may help to optimize the application of G-CSF in a very intensive therapy study like NB90.

Adolescent↗
PubMedDate not supplied

[Bronchopulmonary dysplasia. Retrospective analysis of various forms of treatment and development of a staged therapeutic plan].

50 premature infants with bronchopulmonary dysplasia (BPD) were treated in the Perinatal Center of the University of Heidelberg from January 1990 to December 1992. Gestational age was 24-31 weeks and birthweight was 500 to 1430 grams. 27 infants received dexamethasone only and 14 were initially given dexamethasone followed by beclomethasone inhalation. Nine infants without assisted ventilation were only treated with inhaled beclomethasone. Infants with fluid intake > 150 ml/kg/d and < or = 150 ml/kg/d were analysed separately. Extubation in ventilated infants was possible 1 to 29 days after the beginning of dexamethasone treatment. Most infants who were not ventilated any more could be weaned from oxygen during the period of dexamethasone treatment. Inhaled beclomethasone allowed reduction in supplemental oxygen in all infants. Effects of treatment with dexamethasone and beclomethasone were similar in infants with fluid intake of < 150 ml/kg/d and > 150 ml/kg/d. Our data show that dexamethasone and inhaled beclomethasone improved the clinical course of BPD in premature infants. Fluid intake had no influence on clinical outcome. Based on our results, we suggest guidelines for the treatment of BPD.

Administration, Inhalation↗
PubMedDate not supplied

Blood versus synovial fluid ethanol concentrations in humans.

Many tissues have been analyzed for their relevance in prediction of blood ethanol concentrations, with varying results. Synovial fluid is contained and protected by the bursa sac. Because of its high water content, it may be a suitable biological fluid for analysis if a linear correlation could be established between blood and synovial fluid ethanol concentrations. Blood-synovial fluid ratios of ethanol in 28 human cadavers, using an internal standard, exhibit a good distribution ratio with an average of 0.99 +/- 0.29 and a correlation coefficient of 0.89. This study shows that synovial fluid is a good alternative biological sample for prediction of blood ethanol levels within a range.

Ethanol↗
PubMedDate not supplied

Hypoxia-induced tumour cell migration in an in vivo chicken model.

To investigate the relationship between hypoxia, neovascularisation and tumour cell spread, experiments on the area vasculosa of the early chick embryo under different oxygen concentrations were performed in vivo. Human glioblastoma cells (U-138MG) were inoculated onto the area vasculosa and the fertilised eggs were incubated under conditions of normoxia or hypoxia. For evaluation, we performed in vivo video-microscopy of the area vasculosa and determination of microvessel density (MVD), as well as a histological examination of the fixed specimen. Under hypoxia, MVD was significantly increased compared to normoxic conditions. Only under hypoxic conditions was tumour cell spread found outside the main tumour mass and within the vessels, at times followed by the subsequent development of secondary tumour cell bulks on the area vasculosa. These data lead to the conclusion that hypoxia can stimulate tumour cell migration in this in vivo model.

Animals↗
PubMedDate not supplied

A new approach to phenotyping disseminated tumor cells: methodological advances and clinical implications.

At the time of primary therapy (surgery, systemic chemotherapy and/or radiation), disseminated tumor cells in the bone marrow can be found in almost one-third of patients with cancer of the breast, ovary, esophagus, stomach, colon, and other solid tumors. Whereas the prognostic impact of the mere presence of these cells is still a matter of debate, it has been shown that expression of tumor-associated antigens in disseminated tumor cells is linked to more aggressive disease. Therefore, further characterization of disseminated tumor cells at the protein and gene level has become increasingly important. To date, the most common detection method for disseminated tumor cells in the bone marrow is an immunocytochemical approach using cytokeratin-directed antibodies for detection of epithelial cells and the APAAP system for their visualization. We have established a new double immunofluorescence technique enabling simultaneous detection, phenotyping, and antigen quantification of disseminated tumor cells. Mononuclear cells from bone marrow are enriched by Ficoll gradient centrifugation and cytospins are prepared. Double immunofluorescence is performed using antibodies against cytokeratins 8/18/19 (mAb A45B/B3) and the uPA receptor CD87 (pAb HU277). CD87 expression is recorded by confocal laser scanning microscopy (CLSM) using fluorescence labeled latex beads as the reference; staining intensities of all the scans are then summed and quantified (extended focus). This protocol, originally designed for disseminated tumor cells in bone marrow, can also be applied to disseminated tumor cells in blood, to leukapheresis cells or to cells present in malignant ascites or other malignant effusions. The tumor cells detected may be used for gene and mRNA analyses. Furthermore, disseminated tumor cells also represent interesting targets for clinical studies on patient prognosis or prediction of therapy response as well as for specific tumor-biological therapies.

Biomarkers, Tumor↗
PubMedDate not supplied

Binocular function in human infants: correlation of stereoptic and fusion-rivalry discriminations.

Studies of stereopsis in infants have shown that the average age of onset is 3.5 months. This is the same age at which infants first show evidence of another binocular function, namely, preference for binocularly fusible patterns over rivalrous ones. We tracked the development, using two-alternative forced-choice preferential looking, of the two forms of binocular function in 17 infants, 11 male and six female. They were tested at regular intervals until they showed preferences for 1) a fusible pattern (vertical stripes presented to each eye) over a rivalrous one (vertical stripes presented to one eye, horizontal stripes to the other), and 2) a line stereogram of 32 min crossed disparity over a comparable stereogram with zero disparity. The correlation between the age of onset of the fusion preference (mean 12.4 weeks) and the age of onset of stereopsis (mean 11.0 weeks) was r = 0.79. Female infants showed a preference for the fusible stimulus at a mean age of 9.9 weeks, significantly earlier than the males at a mean age of 13.8 weeks. Similarly, females also showed evidence of stereopsis at an earlier age (9.1 weeks compared with 12.1 weeks for males).

Age Factors↗
PubMedDate not supplied

[Analytical methods for mycotoxins].

Biological, physico-chemical and immunochemical methods are available today for solving the multiple problems which turn up in the course of mycotoxin diagnosis and mycotoxin research. In this review, selected analysis techniques are presented and their limits and possibilities are discussed. The biological methods (chicken-embryo-test, skin irritation test, cell cultures) indicate only toxicities, mostly without further specification for mycotoxins. In contrast, modern physico-chemical analysis (DC, HPLC, CLC, MS) allows the detection of defined mycotoxins in the picogram range; these methods should be employed or official and judicial purposes. The recently developed immunochemical methods (RIA, EIA) are characterized by a simple sample preparation, a short test duration and a high sensitivity; they could be used as a screening method in the course of mycotoxicological control of food and feed.

Animal Feed↗
PubMedDate not supplied

[Pathogenetic factors of Alzheimer disease].

The aim of this article is to review the pathogenetic factors of Alzheimer's disease. Primary correlates of Alzheimer's disease are a dysfunction of and a subsequent decrease in the number of cortical and hippocampal synapses, followed by neurofibrillary and neuritic changes of hippocampal and cortical neurons. While the synapse pathology has been shown to be an early event in Alzheimer's disease, a significant neurofibrillary and neuritic pathology appears to develop only during the course of the disease. Cortical amyloid deposits are an unspecific, age-related phenomenon that can also be found in the brains of the majority of nondemented elderly persons over the age of 65 years. Transgenic amyloid mice proved to be of only limited value as animal models of Alzheimer' disease. According to several studies, there is no correlation between the total number of cortical amyloid plaques and clinical parameters of dementia. However, such a correlation exists with respect to the proportion of neuritic plaques, i.e., with respect to the degree of neuritic degeneration within plaques. In addition to these changes, an interleukin-6 associated inflammatory response has been found in the cortices of Alzheimer patients which is absent in the brains of nondemented elderly persons, and which therefore appears to be a specific element. The significance of changes in the cholinergic neurotransmission for Alzheimer's disease is discussed. Finally, the role of apolipoprotein E and other genetic risk factors is reviewed. In this context it is emphasized that in young persons apolipoprotein E4 is not a suitable early diagnostic marker for Alzheimer's disease.

Aged↗