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Biomedical subjects

M Fischer

Publications and source records attributed to M Fischer.

At least 55 records · Page 3Linked to original sources
PubMed2004

High-precision optical measurement of the 2S hyperfine interval in atomic hydrogen.

We have applied an optical method to the measurement of the 2S hyperfine interval in atomic hydrogen. The interval has been measured by means of two-photon spectroscopy of the 1S-2S transition on a hydrogen atomic beam shielded from external magnetic fields. The measured value of the 2S hyperfine interval is equal to 177 556 860(16) Hz and represents the most precise measurement of this interval to date. The theoretical evaluation of the specific combination of 1S and 2S hyperfine intervals D21 is in fair agreement (within 1.4 sigma) with the value for D21 deduced from our measurement.

Journal Article↗
PubMed2004

[Graves disease. An important differential diagnostic consideration for systemic lupus erythematosus].

Graves disease is a frequent cause (30-40%) of hyperthyroidism. In addition to the classic clinical triad (goiter, exophthalmos and tachycardia), symptoms relating to other organ systems may be found at presentation. Cutaneous manifestations play an important role and may initially be the only clue to the endocrine disorder. A 40-year-old woman with Graves disease presented with features of systemic lupus erythematosus. She had a malar rash, as well as marked hematological changes (thrombocytopenia and leukocytopenia) and antinuclear antibodies (1:640). She also had hyperthyroidism and Graves disease-specific thyroid autoantibodies (TSIg). Her symptoms improved after initiation of antithyroid therapy. Because of overlapping clinical and laboratory criteria, Graves disease can mimic systemic lupus erythematosus. The differentiation requires careful laboratory evaluation. Moreover, both autoimmune diseases may occur in the same patient.

Adult↗
PubMed2004

[The dermatologic consultation].

BACKGROUND: Dermatology and venereology, as a cross-sectional discipline, plays an important role in the interdisciplinary care of inpatients. Nonetheless, only a few studies on dermatological consultations have been performed. We reviewed the dermatological consulting service at the University Hospital of the Martin-Luther-University, Halle, Germany. PATIENTS AND METHODS: All consultations performed in 2001 and 2002 were retrospectively assessed. In addition, the time spent in consulting activities was prospectively recorded over a period of six months (January-June 2003). RESULTS: A total of 2390 consultations were evaluated. Most of the consultations (42.8%) were made on internal medicine wards, followed by pediatrics (11.7%), neurology (9.9%) and cardiothoracic surgery (5.7%). Infectious skin diseases accounted for the most frequent diagnosis at 24.4%. The time lapse between request and performance of the consultation averaged 1.1 days. Patients older than 40 years needed dermatological consultation more frequently than younger patients. The duration of consultation averaged 23 minutes (time to site, patient examination, documentation). Thus, the man-hours required for the consulting service is 33.6 per month. CONCLUSION: The study emphasizes that dermatological consultation services make an important contribution to the care of inpatients. In light of increasing specialization in medicine, the consulting service guarantees interdisciplinary treatment of the patients and is thus an important quality parameter for inpatient care.

Comorbidity↗
PubMed2004

DFB laser diodes in the wavelength range from 760 nm to 2.5 microm.

We present a novel device technology to produce DFB laser diodes which are suitable for tunable diode laser spectroscopy. The new technological approach employs lateral metal distributed feedback (DFB) gratings in close proximity to the laser ridge which results in single mode emission with high spectral purity and output powers as required for most spectroscopic applications. Over the entire wavelength range from the visible (760 nm) up to the near-infrared (2.5 microm) single mode emission can be obtained for devices based on different semiconductor systems such as GaAs, InP and GaSb. Typical side mode suppression ratios are better than 35 dB for cw-room temperature operation and narrow linewidths ensure high spectroscopic resolution.

Chemistry Techniques, Analytical↗
PubMed2004

Experimental life-history evolution: selection on growth form and its plasticity in a clonal plant.

The growth form along the continuum from compact phalanx plants to more loosely packed guerilla plants is an important life-history trait in clonal plants. Prerequisite for its evolution is heritable genetic variation. Starting with 102 genotypes of the stoloniferous herb Ranunculus reptans, we performed one selection experiment on spatial spread per rosette as measure of guerillaness (broad-sense heritability 0.198) and another on plasticity in this trait in response to competition (broad-sense heritability 0.067). After two generations, spatial spread was 36.9% higher in the high line than in the low line (realized heritability +/- SE 0.149 +/- 0.039). Moreover, compared with the low line genotypes of the high line had fewer rosettes, a lower proportion of flowering rosettes, a higher proportion of rooted rosettes, more branches per rosette, longer internodes and longer leaves. In the second experiment, we found no significant direct response to selection for high and low plasticity in spatial spread (realized heritability +/- SE -0.029 +/- 0.063), despite a significant correlated response in plasticity in the length of the first three stolon internodes. Our study indicates a high potential for further evolution of the clonal growth form in R. reptans, but not for its plasticity, and it demonstrates that the clonal growth form does not evolve independently of other clonal life-history characteristics.

Analysis of Variance↗
PubMed2004

[Guideline for radioimmunotherapy of rituximab relapsed or refractory CD20(+) follicular B-cell non-Hodgkin's lymphoma].

This guideline is a prerequisite for the quality management in the treatment of non-Hodgkin-lymphomas using radioimmunotherapy. It is based on an interdisciplinary consensus and contains background information and definitions as well as specified indications and detailed contraindications of treatment. Essential topics are the requirements for institutions performing the therapy. For instance, presence of an expert for medical physics, intense cooperation with all colleagues committed to treatment of lymphomas, and a certificate of instruction in radiochemical labelling and quality control are required. Furthermore, it is specified which patient data have to be available prior to performance of therapy and how the treatment has to be carried out technically. Here, quality control and documentation of labelling are of greatest importance. After treatment, clinical quality control is mandatory (work-up of therapy data and follow-up of patients). Essential elements of follow-up are specified in detail. The complete treatment inclusive after-care has to be realised in close cooperation with those colleagues (haematology-oncology) who propose, in general, radioimmunotherapy under consideration of the development of the disease.

Antibodies, Monoclonal↗
PubMed2003

Heterogeneous clearance rates of long-lived lymphocytes infected with HIV: intrinsic stability predicts lifelong persistence.

Viral replication and latently infected cellular reservoirs persist in HIV-infected patients achieving undetectable plasma virus levels with potent antiretroviral therapy. We exploited a predictable drug resistance mutation in the HIV reverse transcriptase to label and track cells infected during defined intervals of treatment and to identify cells replenished by ongoing replication. Decay rates of subsets of latently HIV-infected cells paradoxically decreased with time since establishment, reflecting heterogeneous lymphocyte activation and clearance. Residual low-level replication can replenish cellular reservoirs; however, it does not account for prolonged clearance rates in patients without detectable viremia. In patients receiving potent antiretroviral therapy, the latent pool has a heterogeneous and dynamic composition that comprises a progressively increasing proportion of stable lymphocytes. Eradication will not be achieved with complete inhibition of viral replication alone.

Antiretroviral Therapy, Highly Active↗
PubMed2003

[Tracheal rupture from blunt chest injury in a child].

Tracheobronchial lesions after blunt chest injury are rare. Diagnosis and therapy can prove to be challenging for the attending physician. Nonrecognition of this injury may entail severe complications. Herein we report the case of a 9-year-old girl with rupture of the trachea due to a fall against the handlebar of her kickboard. The clinical, radiological, and features of the therapy performed are discussed.

Athletic Injuries↗
PubMed2003

[Necrotizing otitis externa caused by Stenotrophomonas maltophilia].

The gram-negative bacterium Stenotrophomonas maltophilia is feared, especially in intensive care wards, as a nosocomial opportunistic pathogen causing fulminant septicemia and organ failure in immunosuppressed patients. A patient with chronic lymphocytic leukemia developed a cutaneous infection with the clinical pattern of necrotizing otitis externa.

Anti-Infective Agents↗
PubMed2003

[Epidemiology of left ventricular systolic dysfunction in the general population of Germany: results of an echocardiographic study of a large population-based sample].

The prevalence of left ventricular systolic dysfunction (LVSD) in the general population is poorly defined. Specifically, the number of asymptomatic individuals with LVSD and, thus, the most appropriate strategy to identify and treat such subjects is still unknown. Therefore, the aim of this study was to document LV dysfunction in a middle-aged (25 to 75 years, mean 51.8+/-13.8) population - based sample in Germany (MONICA Augsburg, n=1678; echocardiography technically adequate n=1418) by M-mode and 2D-echocardiography and to analyze the importance of predisposing contributors. The overall prevalence of an ejection fraction (EF) less than 48% (mean minus 2 SD=LVSD) was 2.3% (n=33), with a slightly higher rate in men than in women (2.8% vs 1.9%, n.s.). LVSD rate increased with age: from 1.5% in individuals younger than 40 years to 4.0% among those older than 60 years of age (p<0.05). Of 33 participants with reduced left ventricular systolic function, 20 presented with at least one cardiovascular disease. The most frequent diagnoses were arterial hypertension, obesity and coronary heart disease. Only 13 subjects (0.9%) of the study population were asymptomatic without a history of cardiovascular disease. Furthermore, only 6 subjects (0.4%, 4 male) in this population presented with a moderate impairment of LV function (EF of 30 to 40%) and only 1 subject (0.07%, male) had severe LVSD (EF less than 30%). Almost all subjects with an EF less than 40% (6 of 7 individuals) had a known history of cardiovascular disease. In conclusion, LVSD is a relatively common finding in the general population. However, severe LVSD is rare in subjects without any concomitant cardiovascular disease. Thus, echocardiographic screening cannot be recommended in the unselected, middle-aged population to identify such patients.

Adult↗
PubMed2003

Gender and perversion--what constitutes a "bad mother".

BACKGROUND: There is a need for reconsidering the conceptualisations of female perverse behavior, especially in connection with motherhood. METHODS AND FINDINGS: Based on case material obtained through psychoanalytic psychotherapy with female patients from a psychosomatic gynecological outpatient clinic, the characteristics of the psychic structure of these patients who presented symptoms of deliberate self harm and of misusing and mistreating their children, are outlined. Another common trait is the embeddedness of their perverse behavior in a generational chain of transmission. Female patients who mistreat their children had been victims of traumatising experiences in their own biography, inflicted by their mothers and directed towards their bodies. DISCUSSION: Female perverse behavior, therefore, is fundamentally different from male perversion: the perverse act in women is aimed against themselves and/or their children. Currently used diagnostic statistical manuals lack categories to describe this symptomatology adequately. Further research is requested to understand a mother's perverse actions and thus develop treatment strategies, without marginalizing these patients.

Adult↗
PubMed2003

Prevalence of left ventricular diastolic dysfunction in the community. Results from a Doppler echocardiographic-based survey of a population sample.

AIMS: The prevalence of left ventricular diastolic abnormalities in the general population is largely unclear. Thus, the aim of this study was, firstly, to identify abnormal diastolic function by echocardiography in an age-stratified population-based European sample (MONICA Augsburg, n=1274, 25 to 75 years, mean 51+/-14) and, secondly, to analyse clinical and anthropometric parameters associated with diastolic abnormalities. METHODS AND RESULTS: The overall prevalence of diastolic abnormalities, as defined by the European Study Group on Diastolic Heart Failure (i.e. age dependent isovolumic relaxation time (92-105 ms) and early (E-wave) and late (A-wave) left ventricular filling (E/A-ratio, 1-0.5)) was 11.1%. When only subjects treated with diuretics or with left atrial enlargement were considered (suggesting diastolic dysfunction) the prevalence was 3.1%. The prevalence of diastolic abnormalities varied according to age: from 2.8% in individuals aged 25-35 years to 15.8% among those older than 65 years (P<0.01). Significantly higher rates of diastolic abnormalities were observed in men as compared to women (13.8% vs 8.6%, P<0.01). Independent predictors of diastolic abnormalities were arterial hypertension, evidence of left ventricular (LV) hypertrophy, and coronary artery disease. Interestingly, in the absence of these predisposing conditions, diastolic abnormalities (4.3%) or diastolic dysfunction (1.1%) were rare, even in subjects older than 50 years of age (4.6%) and (1.2%), respectively. In addition to these factors, diastolic dysfunction was related to high body mass index, high body fat mass, and diabetes mellitus. CONCLUSION: The prevalences of diastolic abnormalities and diastolic dysfunction are higher than that of systolic dysfunction and are increased (despite age-dependent diagnostic criteria) in the elderly. However, in the absence of risk factors for diastolic abnormalities or diastolic dysfunction, namely LV hypertrophy, arterial hypertension, coronary artery disease, obesity and diabetes the condition is rare even in elderly subjects. These data allow speculation on whether diastolic heart failure may be prevented by improved implementation of measures directed against predisposing conditions.

Adult↗
PubMed2003

C2_4_4 microheterogeneity and HLA Class I.

The microheterogeneity of the tetranucleotide repeat locus C2_4_4 situated in the HLA class I region (6p21.3) was investigated by sequencing 50 alleles in an Austrian population sample of 240 unrelated Caucasoid individuals. Several different sequences were found in alleles of the same length. Analysis of the associations between the sequenced C2_4_4 alleles and HLA class I showed a strong linkage disequilibrium between the C2_4_4*9 sequence variants and two different HLA class I haplotypes, as well as between the most common *17 sequence and one HLA-ABC haplotype. No clear cut association could be observed in C2_4_4*16 and *18. The results of this study demonstrate that the exclusive use of microsatellite polymorphisms for the definition of HLA haplotypes is generally not possible.

Alleles↗
PubMed2003

Increased serum levels of interleukin-9 correlate to negative prognostic factors in Hodgkin's lymphoma.

Hodgkin's lymphoma (HL) is characterised by an unbalanced cytokine secretion. Many of these cytokines have been implicated in the regulation of malignant and infiltrating cells. Interleukin-9 (IL-9) has been described to act in an autocrine fashion in HL, stimulating proliferation of the malignant cells. To investigate the potential clinical implication of this observation, a novel ELISA method was used to examine the serum levels of IL-9 in lymphoma patients. High levels of IL-9 were found in the sera from patients with HL (18/44), but not in the sera from non-Hodgkin's lymphoma patients (3/21) or healthy controls. The highest serum IL-9 levels, up to 3350 pg/ml, were observed in the nodular sclerosis subtype, and there was a correlation between IL-9 levels and the negative prognostic factors advanced stage, B-symptoms, low blood Hb and high erythrocyte sedimentation rate. Furthermore, there was no correlation between serum levels of IL-9 and IL-13, a cytokine where serum levels have been speculated to be of clinical importance. This is the first report showing that IL-9 can be measured in serum samples. A novel correlation between increased serum IL-9 levels, HL and clinical features is shown, suggesting that IL-9 is a candidate factor contributing to the development of HL.

Biomarkers, Tumor↗
PubMed2003

Effects of four generations of density-dependent selection on life history traits and their plasticity in a clonally propagated plant.

Life history evolution of many clonal plants takes place with long periods of exclusively clonal reproduction and under largely varying ramet densities resulting from clonal reproduction. We asked whether life history traits of the clonal herb Ranunculus reptans respond to density-dependent selection, and whether plasticity in these traits is adaptive. After four generations of exclusively clonal propagation of 16 low and 16 high ramet-density lines, we studied life history traits and their plasticities at two test ramet-densities. Plastic responses to higher test-density consisted of a shift from sexual to vegetative reproduction, and reduced flower production, plant size, branching frequency, and lengths of leaves and internodes. Plants of high-density lines tended to have longer leaves, and under high test-density branched less frequently than those of low-density lines. Directions of these selection responses indicate that the observed plastic branching response is adaptive, whereas the plastic leaf length response is not. The reverse branching frequency pattern at low test-density, where plants of high-density lines branched more frequently than those of low-density lines, indicates evolution of plasticity in branching. Moreover, when grown under less stressful low test-density, plants of high-density lines tended to grow larger than the ones of low-density lines. We conclude that ramet density affects clonal life-history evolution and that under exclusively clonal propagation clonal life-history traits and their plasticities evolve differently at different ramet densities.

Adaptation, Biological↗