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J Fischer

Publications and source records attributed to J Fischer.

At least 19 recordsLinked to original sources
PubMed2007

Do age- and sex-related variations reliably reflect body size in non-human primate vocalizations? A review.

In vocal communication, the mechanisms of sound production are well understood. The length of the vocal folds determines the minimum fundamental frequency, while the size and the shape of the vocal tract affect its filtering characteristics and hence, the resonant frequencies. Both measures-vocal fold length and vocal tract length-are related to body size and therefore, acoustic features are expected to vary with body size. Because direct measures of body size are difficult to obtain from free-ranging animals, age and sex have often been used as proxies. We surveyed studies which included direct measures of size or weight, and also studies in which only age and/or sex differences were examined. The main purpose was to examine whether age- and sex-related variations in acoustic features meet the predictions generated from our knowledge about sound production. Our survey revealed that compared to smaller animals, larger animals utter longer calls, with a lower fundamental frequency, with smaller formant dispersion, and with the energy concentrated in lower frequencies. Age and sex reliably reflect the influence of body size on acoustic features when gross size differences are examined. However, within age- and sex classes, this relationship may break down. In addition to body size, other factors such as internal state or social context may also influence the structure of vocal signals and highlight the richness of information in calls that is potentially available to listeners.

Aging↗
PubMed2007

Impact of patient- and disease-specific factors on SLNB in breast cancer patients. Are current guidelines justified?

BACKGROUND: The evidence on which to base guidelines for sentinel lymph node biopsy (SLNB) in breast cancer is still limited. In order to facilitate the further implementation of renewed guidelines, we evaluated patient- and disease-specific factors for their impact on the results of SLNB. MATERIALS AND METHODS: Prospective data acquisition from patients undergoing surgery for primary invasive breast cancer was performed. All patients underwent SLNB using the radiocolloid or the combined technique. The association of patient- and disease-specific factors to detection rate and false-negative rate was calculated using univariate and multivariate analyses (P < 0.05 considered as significant). Calculation of the false-negative rate was based on patients who underwent a backup axillary dissection. RESULTS: Among 455 consecutively enrolled patients, a significant inverse association to the detection rate was found for extracapsular extension of non-SLN metastases, body mass index (BMI), number of involved lymph nodes, pT category, tumor size, and age. A significant association to the false-negative rate to identify macrometastases was found for pT category, tumor size, and grading. Other factors, such as prior surgery, multicentric tumor growth, or vascular invasion, showed no influence. A cut-point analysis revealed that a tumor size of 2 cm separated the collective of patients with the highest significance in regard to the false-negative rate (9% vs. 25%). CONCLUSION: Our results indicate that SLNB can be safely used in elderly and obese patients with multicentric tumors and those having undergone prior surgery for benign breast disease. However, the method should be applied with caution in patients with tumors larger than 2 cm.

Adult↗
PubMed2006

The role of fluid wall association on adsorption of chain molecules at functionalized surfaces: a density functional approach.

We present a density functional theory to describe adsorption in systems where selected segments of chain molecules of fluids can bond (or associate) with functional groups attached to the surfaces. Association of active segments with the surface is modeled within the framework of the first-order thermodynamic perturbation theory. We discuss the influence of several parameters such as the density of surface active sites, the energy of association, the chain length, and the number of the active segment in the chain molecule on the structure of the fluid adjacent to the wall. The proposed model can be considered as a first step towards developing a density functional theory of molecular brushes chemically bonded to solid surfaces.

Journal Article↗
PubMed2006

PCV chemotherapy for recurrent glioblastoma.

The authors administered procarbazine, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU, lomustine), and vincristine (PCV) to 86 patients with recurrent glioblastoma. There were three partial responses, but no complete responses. Median progression-free survival was 17.1 weeks and progression-free survival at 6 months was 38.4%. World Health Organization grade III/IV hematologic toxicity was common (25.6%), but nonhematologic toxicity was mild.

Adult↗
PubMed2006

Extensive H(+) release by bone substitutes affects biocompatibility in vitro testing.

Bone substitutes are widespread in orthopedic and trauma surgery to restore critical bony defects and/or promote local bone healing. Cell culture systems have been used for many years to screen biomaterials for their toxicity and biocompatibility. This study applies a human bone marrow cell culture system to evaluate the toxic in vitro effects of soluble components of different bone substitutes, which are already in clinical use. Different specimens of tricalcium phosphates (TCP) (Vitoss, Cerasorb), nondecalcified bovine bone (Lubboc), demineralized human bone matrices (DBM) (Grafton Flex/Putty), and collagen I/III matrix (ACI-Maix) were tested in Dulbecco's modified Eagle's medium (DMEM) and MesenCult culture solution and compared with a biomaterial-free cell culture. Biocompatibility parameters were cell viability evaluated by phase-contrast microscopy and laser flow cytometry, morphology, and the local H(+) release by bone substitutes. There were significant differences (p < 0.05) between the tested biomaterials and culture solutions. Collagen I/III, non-demineralized bovine bone, and TCP materials showed advantages for cell survival over other tested biomaterials (average values of vital cells/mL MesenCult/DMEM: Collagen I/III: 1090/1083; Vitoss: 893/483; Cerasorb: 471/523; Lubboc: 815/410; Grafton Putty: 61/44; Grafton Flex: 149/57). Especially the DBM materials lead to a significant decrease of pH, which is considered to be a major factor for cell death. DMEM culture solution supports cell survival for those bone substitutes that induce an alkaline reaction, whereas MesenCult media promotes cell vitality in biomaterials, which leads to an acidification of culture solution.

Animals↗
PubMed2006

[Implantation of matrix-free cartilage transplants in standardized defects in sheep knee joints].

The goal of the current investigation was to make a comparative analysis of regenerative tissue after autologous de novo cartilage transplantation on the femoral condyles of sheep after a chondral defect. One chondral defect measuring 4 mm in diameter was placed in the center of one medial femoral condyle of each of 48 Suffolk sheep. Twelve defects were left to heal spontaneously, 16 defects were covered with periosteal flaps, and 20 defects were filled with autologous de novo cartilage graft. Macroscopic and microscopic assessments were performed at 26 and at 52 weeks. Regeneration was significantly better (p<0.05) in the transplant group than in the control groups at both 26 weeks and 52 weeks. The differences were most evident in the grade of defect filling, cartilage stability, cell distribution, and matrix assessments. Transplantation of immature, autologous de novo cartilage leads to qualitatively better regeneration both macro- and microscopically than does periosteal flap placement alone. The transplanted, immature cartilage tissue undergoes maturation in vivo. The regenerated tissue has hyaline-like features.

Animals↗
PubMed2006

[Assurance of process-quality in pulmonary practice by means of a peer-review system--a pilot project].

Quality assurance and quality-management have been well anchored in social legislation for years. Peer-reviews to assure process-quality and quality of outcomes have been conducted repeatedly in centres for pulmonary medicine, facilities for pulmonary rehabilitation as well as centres for sleep-medicine. By means of a pilot study we wanted to investigate if assurance of process-quality is feasible and if a peer review system turns out to be a suitable method in pulmonary practice. Medical reports and/or diagnostic protocols of the investigational procedures such as pulmonary function tests, allergy-tests, induction test of bronchial hyperresponsiveness et cetera were randomly collected from nine patients with bronchial asthma or COPD in each of the 44 participating pulmonary practices and forwarded to three peer-reviewers respectively. 396 selected patient-datasets resulted in 1188 reviews. Peer review was conducted by means of a specially developed checklist of markers of process-quality accompanied by an explanatory manual. Measures of quality were determined for every pulmonary practice and a report of results was generated. The health economical efficacy of the therapy and the diagnostic process as well as an assessment of the overall process was evaluated by means of a visual analogue scale. No deficiencies could be detected in clearly more than half of the assessments. Major deficiencies or an unacceptable result in different items could be detected in every sixth assessment. For every item a graphic ranking in terms of benchmarking was generated for each individual report. Since peers were reviewers and subjects of review at the same time, they can now clearly improve and assure their diagnostic and therapeutic process-quality in patients with bronchial asthma and COPD by means of the experience they gained during the review process, as well as by the assessment they received. We were able to demonstrate that a peer-review-system is appropriate to assure process-quality in pulmonary practice and that it is feasible to achieve a continuous assurance and improvement of quality in the long run.

Asthma↗
PubMed2006

[Development of a clinical guideline on medical rehabilitation of patients after lumbar disc surgery].

In cooperation with the Federation of German Pension Insurance Institutes (VDR) and with the VfR Norderney e. V., the university of Witten/Herdecke has developed a clinical guideline on medical rehabilitation for patients after lumbar disc surgery. Methodically, development of this guideline was based on the following three steps: (1) consideration of recent scientific literature, (2) analyses of structures and processes employed in rehab clinics, using consultations with clinic managers, with occupational groups involved in rehabilitation and analysis of patient files, as well as (3) the consensus process. One central result was the statement of substantial paucity of research on evidence for many therapeutic interventions used in orthopaedic rehabilitation of patients after lumbar disc surgery. Analyses and investigations in rehabilitation clinics showed a wide range of therapeutic interventions, used to very different extents. Development of the guideline therefore took place on the basis of consensus-based processes. Using formal consensus techniques according to recommendations of the Association of the scientific medical societies in Germany (AWMF), the guideline presented was developed in cooperation with the occupational groups involved in the rehabilitation process. Its structure focuses on the therapeutic targets, and it includes a clinical algorithm illustrating the orthopaedic rehabilitation process in a simple and understandable manner. The guideline presented is based on recent knowledge and corresponds to stage S2 of development. A further implementation project will evaluate practicability and acceptance of this guideline.

Germany↗
PubMed2006

Autofluorescence endoscopy in surveillance of Barrett's esophagus: a multicenter randomized trial on diagnostic efficacy.

BACKGROUND AND STUDY AIMS: The reference surveillance method in patients with Barrett's esophagus is careful endoscopic observation, with targeted as well as random four-quadrant biopsies. Autofluorescence endoscopy (AFE) may make it easier to locate neoplasia. The aim of this study was to elucidate the diagnostic accuracy of surveillance with AFE-guided plus four-quadrant biopsies in comparison with the conventional approach. PATIENTS AND METHODS: A total of 187 of 200 consecutive Barrett's esophagus patients who were initially enrolled (73 % male, mean age 67 years, mean Barrett's segment length 4.6 cm), who underwent endoscopy for Barrett's esophagus in four study centers, were randomly assigned to undergo either AFE-targeted biopsy followed by four-quadrant biopsies or conventional endoscopic surveillance, also including four-quadrant biopsies (study phase 1). After exclusion of patients with early cancer or high-grade dysplasia, who underwent endoscopic or surgical treatment, as well as those who declined to participate in phase 2 of the study, 130 patients remained. These patients were examined again with the alternative method after a mean of 10 weeks, using the same methods described. The main study parameter was the detection of early cancer/adenocarcinoma or high-grade dysplasia (HGD), comparing both approaches in study phase 1; the secondary study aim in phase 2 was to assess the additional value of the AFE-guided approach after conventional surveillance, and vice versa. Test accuracy measures were derived from study phase 1. RESULTS: In study phase 1, the AFE and conventional approaches yielded adenocarcinoma/HGD rates of 12 % and 5.3 %, respectively, on a per-patient basis. With AFE, four previously unrecognized adenocarcinoma/HGD lesions were identified (4.3 % of the patients); with the conventional approach, one new lesion (1.1 %) was identified. Of the 19 adenocarcinoma/HGD lesions detected during AFE endoscopy in study phase 1, eight were visualized, while 11 were only detected using untargeted four-quadrant biopsies (sensitivity 42 %). Of the 766 biopsies classified at histology as being nonneoplastic, 58 appeared suspicious (specificity 92 %, positive predictive value 12 %, negative predictive value 98.5 %). In study phase 2, AFE detected two further lesions in addition to the initial alternative approach in 3.2 % of cases, in comparison with one lesion with conventional endoscopy (1.7 %). CONCLUSIONS: In this referral Barrett's esophagus population with a higher prevalence of neoplastic lesions, the AFE-guided approach improved the diagnostic yield for neoplasia in comparison with the conventional approach using four-quadrant biopsies. However, AFE alone was not suitable for replacing the standard four-quadrant biopsy protocol.

Adenocarcinoma↗
PubMed2006

Synthesis of the pyrazole isostere of valdecoxib.

4-(5-methyl-3-phenyl-1H-pyrazole-4-yl)-benzenesulfonamide, the pyrazole isostere of valdecoxib was synthesised. The title compound was prepared by a six-step procedure starting from commercially available deoxybenzoin 1. The pyrazole isostere 13 showed slight anti-inflammatory and analgesic activities.

Animals↗
PubMed2005

Erythrokeratoderma variabilis-like ichthyosis in Chanarin-Dorfman syndrome.

Neutral lipid storage disease (Chanarin-Dorfman syndrome) is an autosomal recessive metabolic disorder associated with congenital ichthyosis and a multisystemic accumulation of neutral lipids (lipid droplets) in various types of cells. The clinical presentation has been reported to correspond to that of nonbullous congenital ichthyosiform erythroderma. We report a 4-year-old boy presenting a generalized ichthyosiform disorder manifested by migrating scaly plaques alternating with areas of normal-looking skin, showing erythematous borders with sharp margins, clinically suggestive of erythrokeratoderma variabilis (EKV). A peripheral blood smear revealed cytoplasmic vacuoles in most granulocytes. Genetic studies from the patient and his parents revealed that the patient carried two different and novel mutations of the ABHD5 gene: a nonsense mutation in exon 6 (transmitted by the father) and an insertion/deletion in exon 4 (transmitted by the mother). Our observation demonstrates the clinical heterogeneity of the ichthyosiform dermatoses observed in Chanarin-Dorfman syndrome and widens the clinical range of conditions presenting migrating scaly plaques mimicking EKV.

1-Acylglycerol-3-Phosphate O-Acyltransferase↗
PubMed2005

Correlations of somatophysiological, biochemical, psychosocial and behavioral risk factors of cardiovascular diseases in a sample of employees of Prague enterprises and institutions.

The study is aimed at the detection and intervention of risk factors for cardiovascular diseases (CVD) and at the part played by stress in their development. The methods applied are designed to eliminate the risks and, simultaneously, to identify the function of the two main parts of stress reaction, i.e., in terms of the extent, level and type of the stressors experienced, and in terms of the level of mental resilience and related psychosocial factors which affect the experiencing of and coping with stress. The purpose of medical examination based on the patient's history, subjective complaints and objective tests, including a study of dietary habits and psychological methods was to establish the status praesens and identify the main risk factors and symptoms leading to ischemic heart disease (IHD). Intervention was performed in subjects with increased cardiovalscular risk factors.

Adult↗
PubMed2004

Break-up of the Atlantic deep western boundary current into eddies at 8 degrees S.

The existence in the ocean of deep western boundary currents, which connect the high-latitude regions where deep water is formed with upwelling regions as part of the global ocean circulation, was postulated more than 40 years ago. These ocean currents have been found adjacent to the continental slopes of all ocean basins, and have core depths between 1,500 and 4,000 m. In the Atlantic Ocean, the deep western boundary current is estimated to carry (10-40) x 10(6) m3 s(-1) of water, transporting North Atlantic Deep Water--from the overflow regions between Greenland and Scotland and from the Labrador Sea--into the South Atlantic and the Antarctic circumpolar current. Here we present direct velocity and water mass observations obtained in the period 2000 to 2003, as well as results from a numerical ocean circulation model, showing that the Atlantic deep western boundary current breaks up at 8 degrees S. Southward of this latitude, the transport of North Atlantic Deep Water into the South Atlantic Ocean is accomplished by migrating eddies, rather than by a continuous flow. Our model simulation indicates that the deep western boundary current breaks up into eddies at the present intensity of meridional overturning circulation. For weaker overturning, continuation as a stable, laminar boundary flow seems possible.

Journal Article↗
PubMed2004

[Importance of timing of music therapy in chemotherapy of cancer patients].

Neither the measured stress-hormones, nor Beta-Endorphin have been influenced by music therapy. Music therapy should be initiated before the beginning of chemotherapy, preferably shortly after the operation. The greatest profit of an accompanying music therapy is between the chemotherapy courses, because the whole energy of the patient during chemotherapy is directed to questions, worries and practical aspects.

Adrenocorticotropic Hormone↗
PubMed2004

[In vivo and in vitro bone regeneration from cord blood derived mesenchymal stem cells].

BACKGROUND: Mesenchymal stem cells with an osteoblastic differentiating potency are investigated in regard of probable tissue engineering for further clinical application. The following report describes the use of cord blood derived stem cells as an alternative to other stem cell populations for bone regenerating tissue engineering. METHODS: To demonstrate the multipotency of cord blood derived mesenchymal stem cells, unrestringated somatic stem cells (USSC) were isolated from cord blood and underwent an osteo-, chondro- and adipoblastic in vitro stimulation. To evaluate the osteoinductive potency of a porcine collagen I/III cell carrier USSC were incubated on this matrix. To investigate the in vivo effects of human USSC an athymic rat model was developed. These cells were transplanted into a femoral defect. RESULTS: Cord blood derived mesenchymal stem cells (USSC) have an in vitro multipotency and show adipo-, chondro- and osteogenic differentiation. The porcine collagen I/III carrier promoted an osteoblastic differentiation. USSC survived after xenotransplantation in an athymic rat and differentiated into osteoblasts filling the bony defect zone. CONCLUSION: Human USSC are a mesenchymal multipotent stem cell population that shows osteoblastic differentiation onto a collagen I/III carrier in vitro as well as in an athymic rat in vivo.

Adipocytes↗
PubMed2004

[Collisiontumour composed of glioblastoma and meningioma-a case report].

A 51 year old caucasian male presented with headache, facial nerve paresis and continuing contraction of the visual field. CT scan revealed a singular intracerebral contrast enhancing lesion in the left frontal lobe. Intraoperatively the tumour was well demarcated. Frozen sections showed a high grade glioma. Paraffin sections revealed, in addition to the gliomatous component, some sharply demarcated nests of meningothelial cells. Immunohistochemistry with glial fibrillary acidic protein and epithelial membrane antigen confirmed a collision tumour consisting of a glioblastoma WHO-grade IV and a meningothelial meningioma WHO-grade I. The coincidence of these two different tumours at the same time and the same location leads us to the speculation, that the collision tumour might have been caused by malignant transformation of a reactive astrogliosis surrounding the meningioma.

Brain Neoplasms↗
PubMed2004

[A security protocol for the exchange of personal medical data via Internet: monitoring treatment and drug effects].

We present a security protocol for the exchange of medical data via the Internet, based on the type/domain model. We discuss two applications of the protocol: in a system for the exchange of data for quality assurance, and in an on-line database of adverse reactions to drug use. We state that a type/domain security protocol can successfully comply with the complex requirements for data privacy and accessibility typical of such applications.

Access to Information↗