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Biomedical subjects

A Beckmann

Publications and source records attributed to A Beckmann.

At least 19 recordsLinked to original sources
PubMed2006

Cardiac surgery in Germany during 2005: a report on behalf of the German Society for Thoracic and Cardiovascular Surgery.

All cardiac surgical procedures performed in 79 German cardiac surgical units throughout the year 2005 are presented in this report, based on a voluntary registry, which is organized by the German Society for Thoracic and Cardiovascular Surgery. In 2005, a total of 98 860 cardiac surgical procedures (ICD and pacemaker procedures excluded) were collected in this registry. More than 8.4 % of the patients were older than 80 years, compared to 7.8 % in 2004. Hospital mortality in 54 126 isolated CABG procedures (9.7 % off-pump) was 2.9 %, while a mortality of 4.5 % was observed in 19 203 isolated valve procedures. This registry is an important tool of the German Society for Thoracic and Cardiovascular Surgery to ensure a continuous and voluntary quality assurance and illustrate the development of cardiac surgery in Germany.

Adolescent↗
PubMed2003

Inflammatory infiltrates in the spinal cord of patients with Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is defined as an acute inflammatory demyelinating polyradiculoneuropathy (AIDP) of the peripheral nervous system. Reports on central nervous system involvement in patients with GBS are rare and the histopathological analysis was usually restricted to conventional staining techniques. We were able to investigate four cases with GBS at autopsy in respect to the inflammatory infiltrates and histopathological changes in the spinal cord by immunohistochemistry using a panel of antibodies recognizing lymphocytes and different macrophage-activation antigens. There were increased inflammatory cell infiltrates comprising lymphocytes and macrophages in the spinal cord of two cases. In one of these two cases, GBS predominantly affecting the motor system similar to acute motor axonal neuropathy (AMAN) developed following hepatitis B vaccination; in the second one, GBS developed rapidly 4 days after onset of intravenous purified GM1-ganglioside application affecting the motor as well as the sensory system, resembling acute motor sensory axonal neuropathy (AMSAN). Impairment of the spinal anterior horn cells with their axons was suggested to be responsible for prolonged motor symptoms and the predominantly axonal type of neuropathy at least as a late-stage feature in these two cases with fatal outcome. Insignificant cellular infiltrates in the spinal cord were noted in the other two GBS cases. Focal cellular infiltration of spinal nerve roots and meninges was similar in all cases.

Adult↗
PubMed2001

Results of a collaborative study of the EDNAP group regarding the reproducibility and robustness of the Y-chromosome STRs DYS19, DYS389 I and II, DYS390 and DYS393 in a PCR pentaplex format.

A collaborative exercise was carried out by the European DNA Profiling Group (EDNAP) in the frame work of the STADNAP program, i.e. standardization of DNA profiling in Europe, in order to evaluate the performance of a Y-chromosome STR pentaplex, which includes the loci DYS19, DYS389 I and II, DYS390 and DYS393 and to determine whether uniformity of results could be achieved among different European laboratories. Laboratories were asked to analyze the five Y-STRs using singleplex and multiplex conditions in three bloodstains and one mixed stain (95% female and 5% male). All the laboratories reported the same results even for the mixed stain included in the exercise. This demonstrates the reproducibility and robustness of Y-chromosome STR typing even with multiplex formats and proves the usefulness of Y-STR systems for analyzing mixed stains with a male component.A total of 930 male samples from 10 different populations from Europe were also analysed for all the loci included in the pentaplex. Eight of these ten populations also included haplotype data. As for single gene analysis, haplotype diversity was higher in Germany and Italy and lower in Western European countries and Finland. Pairwise haplotype analysis shows the Finnish departure from the rest of the populations and a relatively homogeneity in the other European populations with F(ST) estimates lower than 0.05.UPGMA analysis shows an association of Western European population (Ireland, UK, Portugal and Galicia) on the one hand and central European populations on the other.

Blood Stains↗
PubMed2001

Genetic characterisation of invasive breast cancer: a comparison of CGH and PCR based multiplex microsatellite analysis.

AIMS: Comparative genomic hybridisation (CGH) is a reliable tool to gain an overview of all unbalanced chromosomal alterations within a tumour. Nevertheless, the high numbers of tumour cells required and the comparatively low resolution are drawbacks of this technique. Polymerase chain reaction (PCR) based multiplex microsatellite analysis represents a semi-automated, highly reproducible method, which requires small amounts of tumour cells. This is a comparative study of CGH and microsatellite analysis. METHODS: Eighty one samples of invasive breast cancer were investigated by two sensitive multiplex PCRs containing three microsatellites each of six markers (D6S261, D11S907, D6S300, D11S927, D8S272, and D11S925), and two additional microsatellite markers located within intron 1 of the epidermal growth factor receptor gene (egfr) and p53 (p53CA). RESULTS: At least one example of loss of heterozygosity was detectable in all breast cancer tissues. However, the overall rate of accordance between the two methods tested was only 61%. An increasing rate of the number of genetic alterations in each case was mirrored by a constantly increasing fractional allelic loss index. CONCLUSIONS: PCR based multiplex microsatellite analysis using this panel of eight microsatellite markers not only enables the characterisation of cells that have malignant potential in a high frequency of patients with breast cancer, but can also give an estimate of the degree of genetic progression.

Breast Neoplasms↗
PubMed2000

Length and loss of heterozygosity of an intron 1 polymorphic sequence of egfr is related to cytogenetic alterations and epithelial growth factor receptor expression.

Overexpression of epithelial growth factor receptor (EGFR) is correlated with a poor prognosis and reduced steroid receptor expression. Recently, it was demonstrated that the length of a CA repeat in the intron 1 of EGFR correlated with the expression of EGFR in vitro. We investigated 112 cases of cancerous and noncancerous breast tumor samples for loss of heterozygosity (LOH) in intron 1 of the egfr gene and determined the intratumoral EGFR content and genetic alterations by comparative genomic hybridization. Heterozygous tumors with short CA repeats showed elevated EGFR expression in contrast to tumors with longer CA repeats. Tumors with LOH in intron 1 of egfr revealed higher EGFR expression when the longer allele was lost compared with loss of the shorter allele. Additionally, tumors with a loss of the long allele showed more chromosomal alterations, especially a higher frequency of amplifications. We conclude that the CA repeat status in intron 1 of the egfr gene also modulates the intratumoral EGFR content in vivo. Furthermore, LOH at the CA repeat is associated with genetically advanced tumors. Therefore, allele-specific gene expression due to LOH of the CA repeat could be assumed to be an important event in invasive breast cancer development.

Alleles↗
PubMed2000

Screening for Charcot-Marie-Tooth type 1A and hereditary neuropathy with liability to pressure palsy in archival nerve biopsy samples by direct-double-differential PCR.

Chromosomal imbalance of the peripheral myelin protein-22 gene (PMP22) is known to be the most frequent genetic abnormality in Charcot-Marie-Tooth disease type 1 (CMT1) and hereditary neuropathy with liability to pressure palsy (HNPP). We applied a new quantitative PCR method, the direct-double-differential PCR (dddPCR), to the gene dosage determination of PMP22. The method allows the quantification of the PMP22 gene copy number independently from DNA fragmentation, even in highly degraded DNA from up to 12-year-old sural nerve biopsy samples. Chromosomal imbalance of the PMP22 gene, which had been detected by examination of four microsatellites located directly adjacent to the PMP22 gene, between the CMT1A-repetition (CMT1A-REP) elements was reliably confirmed by the dddPCR. Using this method we unexpectedly identified two cases with PMP22 imbalance, although morphologically the neuropathies were of a neuronal or axonal type and not of a demyelinating type as usual. One sural nerve biopsy was from a 58-year-old male diabetes mellitus patient with a disproportionately severe polyneuropathy showing a heterozygous duplication of PMP22. The second biopsy exhibiting a heterozygous deletion of PMP22 was from a 58-year-old female patient with a more axonal than demyelinating type of neuropathy without typical tomaculous changes seemingly altered by exogenous, possibly traumatic factors other than diabetes mellitus. Thus, the dddPCR provides a fast and reliable diagnostic tool for the screening and identification of CMTIA and HNPP cases, which is fast and may be essential even when nerve biopsies show morphologically atypical changes.

Biopsy↗
PubMed2000

Simultaneous carotid endarterectomy and coronary artery bypass grafting in 313 patients.

The coincidence of coronary and carotid artery disease (uni- or bilateral, with or without involvement of the supra-aortic branch) is still a problem with regards to surgical strategy. Since the opening of the Heart Centre Duisburg in 1989 the authors have favoured a simultaneous approach to lesions in both arterial systems in order to avoid myocardial infarction or stroke. The aim of this retrospective study was to review the early and late results of the combined procedures for the endpoints of death, myocardial infarction and stroke. During a 7-year period (1990-1997) a total of 18,050 patients underwent cardiac surgery and extracorporeal circulation. Simultaneous intervention in both arterial systems was performed in 313 patients (1.73%). All patients underwent preoperative ultrasonic diagnostics, digital subtraction angiography, neurological examination and cardiac catheterization. The principal indication was the need for myocardial revascularization, and symptomatic or asymptomatic carotid stenosis of 80% diameter reduction or more (with or without contralateral disease). The mean age was 66.4 +/- 6.9 years; 240 patients (76.7%) were male, 73 patients (23.3%) female; 243 patients (77.6%) had triple-vessel disease, 82 patients (26.2%) had left main stenosis and 94 patients (43.5%) had a reduced ejection fraction. A total of 171 patients (54.6%) had a previous myocardial infarction, 54 patients (17.3%) presented with unstable angina and nine patients (2.9%) had prior coronary artery bypass grafts. Eighty-seven patients (27.8%) had an internal carotid artery stenosis on the right side, 75 patients (24%) on the left side and 151 patients (48.2%) lesions in both carotid arteries. Prior carotid endarterectomy was performed in 14 patients (4.5%), and the contralateral carotid was occluded in 24 patients (7.7%). Fifty patients had a previous stroke (16%) and 185 patients (59.1%) were asymptomatic. During surgery, the the carotid artery was first exposed, followed by median sternotomy, systemic heparinization, cannulation and cardiopulmonary bypass. After achieving mild hypothermia (30 degrees C), endarterectomy was performed with a venous patch closure. An occluded contralateral carotid artery was always an indication for shunting. Coronary artery bypass grafting was carried out with intermittent cross-clamping under moderate hypothermia (22-27 degrees C). Ten patients suffered a myocardial infarction (3.2%), seven patients (2.2%) had an apoplectic insult perioperatively ( < 30 days) and one patient (0.3%) had an event during long-term follow-up. Early overall mortality was 28 (8.9%), of which 13 were cardiac related (4.2%). Overall late mortality was eight (2.6%), of which six were cardiac related (1.9%). Mean survival time was 6.18 years. Simultaneous carotid endarterectomy and myocardial revascularization can be justified as a routine surgical management of severe lesions in both arterial systems. The risk of myocardial infarction, apoplectic stroke or mortality was not significantly different than isolated procedures.

Aged↗
PubMed2000

Evidence for a melatonin receptor within pancreatic islets of neonate rats: functional, autoradiographic, and molecular investigations.

In a recent perifusion investigation, we showed that the pineal secretory product melatonin reduces insulin secretion from isolated pancreatic islets of neonate rats stimulated with potassium chloride (KCl), glucose, and forskolin. This effect of melatonin was reproduced with doses ranging from 200 pmol/L to 5 micromol/L. Because it is generally accepted that melatonin exerts some of its biological effects through specific, high-affinity pertussis-toxin-sensitive G-protein-coupled receptors, we blocked the putative melatonin receptor of pancreatic islets using both the non-hydrolyzable guanosine triphosphate analog guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS, 30 micromol/L) and the melatonin antagonist luzindole (10 micromol/L). Both GTPgammaS and luzindole caused a near normalization of the melatonin-induced inhibition of the forskolin-stimulated insulin secretion. To localize putative melatonin receptors within the pancreatic islets autoradiographic studies were additionally carried out. These investigations showed specific binding of 2-[125I]iodomelatonin, which were in exact correspondence with the localization of the islets. In addition, gray-level analysis showed that unlabeled melatonin was able to reduce the binding of 2-[125I]iodomelatonin in a dose-dependent manner. Concentrations of unlabeled melatonin of 10(-9) mol/L produced a 50% reduction in specific binding, whereas concentrations of 10(-6) mol/L displaced the binding completely. Likewise, the results of molecular investigations showed that the rat pancreas contains a melatonin receptor, since reverse transcription polymerase chain reaction (RT-PCR) experiments, using specific primers for the rat melatonin receptor Mel1a, showed that mRNA for this melatonin receptor type is expressed in pancreatic tissue of newborn rats. In summary, it may be said that our functional. autoradiographic, and molecular results indicate that the Mel1a receptor is located on the pancreatic islets, possibly in the beta cells.

Animals↗
PubMed1998

Randomized, controlled phase II trial of subcutaneous interleukin-2 in combination with highly active antiretroviral therapy (HAART) in HIV patients.

OBJECTIVE: To determine the immunological, virological and clinical effects of subcutaneous IL-2 in 44 HIV-patients in conjunction with pre-existing tri-therapy (zidovudine, 3TC, saquinavir). DESIGN: Partially randomized, controlled, prospective trial. SETTING: Single center study at tertiary care center. PATIENTS: Sixty four patients (CD4 count 200-500 x 10(6)/l). INTERVENTION: Fourty four patients were randomized to receive 5-day cycles of IL-2 (9 Mio IU/d) every 6 weeks (Group A) or whenever the CD4 cell count dropped below the 1.25-fold of baseline (Group B), whereas 20 control patients received the same HAART without IL-2. OUTCOME MEASURES: The optimal individual treatment interval and the immunological and virological effects of subcutaneously administered IL-2 were analysed. Importantly, the level of cellular in vivo immunity and the frequency of dermatological marker diseases and infectious complications were assessed. RESULTS: IL-2 was well tolerated although fever, influenza-like symptoms and indurated injection sites were commonly encountered. After 1 year of IL-2, there was a median increase of more than 100 x 10(6)/l CD4 cells in both IL-2 groups in contrast to the controls (P < 0.01, 0.01 and not significant). The median HIV load did not increase either in plasma or in lymph nodes. Lymphocyte activation decreased as assessed by MHC class II (P < 0.001), CD25 (P < 0.001) and CD38 expression (P < 0.005). Although delayed type hypersensitivity against common recall antigens increased in both IL-2 groups, it did not reach statistical significance. However, it is of note, that in 7 of 11 (63.6%) patients delayed type hypersensitivity against recombinant HIV antigens improved significantly. Whereas there was no opportunistic infection in either IL-2 group, three cases of Kaposi's sarcoma occurred in the controls. Dermatological indicator diseases (thrush, condyloma, herpes simplex) were found to occur more frequently in the control group. CONCLUSIONS: Subcutaneous IL-2 in addition to HAART was safe and led to sustained qualitative and quantitative immunological improvements in the majority of patients. Individualisation of therapy intervals further improved the efficacy and tolerance of IL-2.

Adult↗
PubMed1998

Direct quantification of polymerase chain reaction fragments using field-amplified sample injection in capillary zone electrophoresis for gene dosage estimation.

To assess gene dosages for clinical application, especially for prognostication of cancer, we developed a direct quantification method for polymerase chain reaction products. We report on an application of field amplified sample injection (FASI) to capillary zone electrophoresis which allows the quantification of PCR products without sample preparation. Using an external standard and UV detection for the quantification of DNA, a low coefficient of variation has been obtained. Overall, the described method provides a fast and easy tool for PCR product quantification in clinical laboratories.

DNA↗
PubMed1997

Translational research studies of erbB oncogenes: selection strategies for breast cancer treatment.

Specific gene families, e.g. encoding members of signal transduction pathways, show a gene dosage sensitivity. We report on the determination of the gene dosages of egfr and c-erbB-2 in relation to the intratumoral concentration of the tyrosine kinase receptor protein EGFR and p185c-erbB-2 and the clinical outcome of breast cancer patients in a retrospective study. Prognostic unfavorable subgroups were determined in a life-table analysis by (a) an average gene copy number of egfr of less than 0.4 and greater than 1.6 and an intratumoral EGFR concentration of more than 56 fmol/mg, (b) an intratumoral p185c-erbB-2 concentration above 26 HNU/mg and (c) a quotient of egfr and c-erbB-2 average gene copy numbers of less than 0.15 and greater than 4.35.

Breast Neoplasms↗
PubMed1997

Immediate early gene expression and delayed cell death in limbic areas of the rat brain after kainic acid treatment and recovery in the cold.

Systemic injection of kainic acid (KA) results in characteristic behaviors and programmed cell death in some regions of the rat brain. We used KA followed by recovery at 4 degrees C to restrict damage to limbic structures and compared patterns of immediate early gene (IEG) expression and associated DNA binding activity in these damaged areas with that in spared brain regions. Male Wistar rats were injected with KA (12 mg/kg, i.p.) and kept at 4 degrees C for 5 h. This treatment reduced the severity of behaviors and restricted damage (observed by Nissl staining) to the CA1 and CA3 regions of the hippocampus and an area including the entorhinal cortex. DNA laddering, characteristic of apoptosis, was first evident in the hippocampus and the entorhinal cortex 18 and 22 h after KA, respectively. The pattern of IEG mRNA induction fell into three classes: IEGs that were induced in both damaged and spared areas (c-fos, fos B, jun B, and egr-1), IEGs that were induced specifically in the damaged areas (fra-2 and c-jun), and an IEG that was significantly induced by saline injection and/or the cold treatment (jun D). The pattern of immunoreactivity closely followed that of mRNA expression. Binding to the AP-1 and EGR DNA consensus sequences increased in all three regions studied. This study describes a unique modification of the animal model of KA-induced neurotoxicity which may prove a useful tool for dissecting the molecular cascade that ultimately results in programmed cell death.

Animals↗
PubMed1994

Gene expression during ethanol withdrawal.

The expression of the proteins (C-FOS and C-JUN) encoded by the immediate early genes c-fos and c-jun was investigated in the brains of rats undergoing ethanol withdrawal. Both proteins were induced in the cerebral cortex, the piriform cortex, the olfactory bulb, the inferior colliculus, the granular cell layer of the cerebellum and in the brain stem, but only C-JUN was induced in the hippocampus of animals undergoing withdrawal without overt seizures. C-FOS was detected in the hippocampus only in animals with overt seizures. Maximal C-FOS expression occurred 15 hr after withdrawal while C-JUN was maximal at 24 hr. Gel-shift assays indicated the formation of AP-1 binding factors in nuclear extracts of the cerebral cortex, hippocampus and cerebellum 15 and 17 hr after withdrawal. These data reveal a complex pattern of immediate early gene expression during ethanol withdrawal, which may be associated with changes in neuronal plasticity underlying phenomena such as withdrawal kindling.

Animals↗
PubMed1993

Heterogeneous lipoprotein (a) size isoforms differ by their interaction with the low density lipoprotein receptor and the low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor.

Lipoprotein (a) (Lp(a)) is a complex of low density lipoprotein (LDL) with apolipoprotein (apo) (a). To examine the size distribution of Lp(a), plasma was separated by fast flow gel filtration and Lp(a):B complexes were determined in the eluate by enzyme immunoassays, in which detection was performed with monoclonal antibodies specific for apoB. Lp(a):B particles displayed apparent molecular masses (M(r)) of 2 x 10(6) to at least 10 x 10(6). Lp(a) size isoforms differed by the expression of apoB epitopes and their interaction with cultured human skin fibroblasts. LDL was more effective in inhibiting binding, uptake, and degradation of low M(r) Lp(a) than of high M(r) Lp(a). In contrast, Glu-plasminogen, alpha 2-macroglobulin and tissue-type plasminogen activator were more effective in competing for the cellular degradation of high M(r) Lp(a) than of low M(r) Lp(a). Ligand blotting revealed that Lp(a) bound to the low density lipoprotein receptor, the low density lipoprotein receptor-related protein/alpha 2-macroglobulin receptor (LRP) and to two other endosomal membrane proteins. We propose that the LDL receptor preferentially internalizes low M(r) Lp(a), whereas LRP may have a role in the clearance of high M(r) Lp(a).

Cells, Cultured↗
PubMed1993

Wound care.

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Bandages↗