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Biomedical subjects

A Müller

Publications and source records attributed to A Müller.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Visual impairment -- implications on health, costs and predictions for the future].

Vision impairment in the elderly is significantly related to increased morbidity as well as mortality rates. Recent studies suggest the true costs associated with visual impairment and blindness to be much higher than reported previously. Without successful interventions the number of visually impaired or blind people world-wide will double within the next 20 years. The lack of a significant world-wide reduction in avoidable visual impairment and blindness would have substantial social as well as economical consequences. In contrast, three-quarters of all visual impairments are avoidable and therefore unnecessary. In summary, vision Impairment deserves a higher degree of attention by the public as well as from governments.

Aged↗
PubMed2005

T-cell independent production of salivary secretory IgA after hematopoietic stem cell transplantation in children.

This study examined the recovery of secretory IgA (S-IgA) in saliva after hematopoietic stem cell transplantation (HSCT) in 35 children and young people between the ages of 3 and 27 years (mean=13.6), and compared this recovery with that of serum immunologic constituents. Reference values for human salivary S-IgA in saliva were obtained from 77 healthy control subjects between the ages of 7 and 25 years (mean=11.4). In the 35 patients, a nadir of secretory IgA concentrations in saliva (S-IgA) was observed between the 3rd and the 4th month, and a return to normal values 1 year after HSCT. Serum IgA concentrations reached their nadir in the 6th month, and normalized in the 18 months after HSCT. The recovery of T-helper cells (CD4+/3+) was also delayed to beyond 18 months. We found a significant correlation between the reconstitution pattern of S-IgA and that of T-helper lymphocytes, but no correlation was found between the post-transplant evolutions of S-IgA and serum IgA, or between S-IgA and T-helper cells. The recovery of S-IgA was more rapid than that of serum IgA and appeared to be T-helper cell independent.

Adolescent↗
PubMed2005

The use of an open-freezing system with self-seeding for cryopreservation of mouse ovarian tissue.

Chemoradiotherapy in young women with cancer has substantially improved life expectancy in these patients, but these treatments often cause infertility. One method of preserving fertility is to cryopreserve ovarian tissue. In this study, an automatic open-vessel freezing system with self-seeding was tested for cryopreservation of murine ovarian tissue; the mouse is a species widely used in human and veterinary medical research. The freezing system concerned, is used for cryopreservation of oocytes and embryos in Europe. Twenty severe combined immunodeficiency (SCID) mice were ovariectomized. The ovarian tissue was either directly transplanted heterotopically into the neck muscle (group 1, n = 6) or cryopreserved after equilibration with 1.5 M dimethylsulphoxide and propanediol. After thawing, the tissue was transplanted in SCID mice (group 2, n = 6). Before and after thawing, a part of the ovarian tissue was examined with the LIVE/DEAD fluorescent viability staining. The count of follicles revealed intact (fresh 24.1%/thawed 21.7%), impaired (fresh 35.1%/thawed 35.4%), and dead follicles (fresh 40.8%/thawed 42.9%). The healthy follicular loss because of the cryopreservation was 10.0%. All recipient mice were killed after 3 weeks. Transplanted ovarian tissue was found macroscopically in all mice. Histological examination showed several growing follicles in all developmental phases in both groups of SCID mice [group 1 (fresh grafts): 315 +/- 76.3 (mean +/- SD); group 2 (cryopreserved grafts): 237 +/- 63.4]. These results demonstrate that the use of an open-freezing system allows the survival of cryopreserved mouse ovarian tissue.

Animals↗
PubMed2005

Diminished pregnancy rates in endometriosis due to impaired uterotubal transport assessed by hysterosalpingoscintigraphy.

OBJECTIVE: To investigate uterotubal transport by means of hysterosalpingoscintigraphy (HSSG) in women with and without endometriosis. DESIGN: A prospective observational study. SETTING: University Hospital, Department of Obstetrics and Gynaecology, Division of Reproductive Medicine and Gynaecologic Endocrinology with 350 in vitro fertilisation (IVF)/intracytoplasmic sperm injection (ICSI) cycles and 400 intrauterine insemination (IUI) cycles/year. POPULATION: Cases included 56 infertile women with laparoscopic proven endometriosis and patent fallopian tubes. Twenty-two women with partners suffering from male factor infertility served as controls. METHODS: A diagnostic cycle incorporating HSSG was performed. Subsequently, patients underwent either four cycles of timed intercourse (TI) or IUI in order to achieve pregnancy. If pregnancy did not occur, IVF or ICSI was performed. MAIN OUTCOME MEASURES: Evaluation of uterotubal transport capacity in women with endometriosis and healthy controls. RESULTS: Patients suffering from endometriosis (group I) showed a significant reduction in physiologic uterotubal transport function: While 20 patients (36%) had ipsi- or bilateral uterotubal transport, there was pathological uterotubal transport contralateral to the dominant follicle or a complete failure of transport capacity (negative HSSG) in 36 patients (64%). In the controls (group II), transport function was significantly different: 15 of 22 patients (68%) revealed ipsi- and bilateral tubal demonstration, while 5 patients (22%) showed contralateral transport and 2 patients (10%) showed negative HSSG (P= 0.01). Twenty-three pregnancies were observed (pregnancy rate: 29%). Eleven out of 14 (79%) women with ipsi- or bilateral tubal transport function fell pregnant by means of TI or IUI. In seven of nine patients (78%) with a failure in tubal transport, pregnancy was achieved by IVF/ICSI, despite acceptable semen parameters (P= 0.01). CONCLUSIONS: Endometriosis is significantly associated with a reduction in physiologic uterotubal transport capacity compared with controls. This resulted in diminished pregnancy rates even in women with normozoospermic partners. Therefore, IVF/ICSI may be required even when fallopian tubes are patent or semen quality is normal.

Adult↗
PubMed2005

Persistence of bovine viral diarrhea virus is determined by a cellular cofactor of a viral autoprotease.

Polyprotein processing control is a crucial step in the life cycle of positive-strand RNA viruses. Recently, a vital autoprotease generating an essential viral replication factor was identified in such a virus, namely, the pestivirus bovine viral diarrhea virus. Surprisingly, the activity of this protease, which resides in nonstructural protein 2 (NS2), diminishes early after infection, resulting in the limitation of viral RNA replication. Here, we describe that a cellular chaperone termed Jiv (J-domain protein interacting with viral protein) acts as a cofactor of the NS2 protease. Consumption of the intracellular Jiv pool is responsible for temporal regulation of protease activity: overexpression of Jiv interfered with regulation and correlated with increased accumulation of viral RNA; downregulation of the cellular Jiv level accelerated the decline of protease activity and reduced intracellular viral RNA levels and virion production. Accordingly, the amount of a cellular protein controls pestiviral replication by limiting the generation of active viral protease molecules and replication complexes. Importantly, this unique mechanism of replication control is essential for maintenance of the noncytopathogenic phenotype of the virus and thereby for its ability to establish persistent infections. These results add an entirely novel aspect to the understanding of the molecular basis of viral persistence.

Amino Acid Sequence↗
PubMed2005

Using interaction graphs for analysing the therapy process.

BACKGROUND: Therapy processes are complex dynamical systems where several variables are constantly interacting with each other. In general, the underlying mechanisms are difficult to assess. Our approach is to identify the dependency structure of relevant variables within the therapy process using interaction graphs. These are instruments for multivariate time series which are based on the analysis of partial spectral coherences. We used interaction graphs in order to investigate the therapy process of a multimodal therapy concept for fibromyalgia patients. Our main hypothesis was that self-efficacy plays a central role in the therapy process. METHODS: Patients kept an electronic diary for 13 weeks. Pain intensity, depression, sleep quality, anxiety and self-efficacy were assessed via visual analogue scales. The resulting multivariate time series were aggregated over individuals, and partial spectral coherences between each pair of the variables were calculated. From the partial coherences, interaction graphs were plotted. RESULTS: Within the resulting graphical model, self-efficacy was strongly related to pain intensity, depression and sleep quality. All other relations were substantially weaker. There was no direct relationship between pain intensity and sleep quality. CONCLUSIONS: The relations between two variables within the therapy process are mainly induced by self-efficacy. Interaction graphs can be used to pool time series data of several patients and thus to assess the common underlying dependency structure of a group of patients. The graphical representation is easily comprehensible and allows to distinguish between direct and indirect relationships.

Adult↗
PubMed2005

Is PR3-ANCA formation initiated in Wegener's granulomatosis lesions? Granulomas as potential lymphoid tissue maintaining autoantibody production.

In Wegener's granulomatosis (WG), antiproteinase 3 (PR3) autoantibodies (PR3-ANCA) are crucial in the development of generalized vasculitis. Wegener's pathognomonic lesion, a granulomatous inflammation of the upper and lower respiratory tract, contains abundant lymphocytes and macrophages. Lymphocyte clusters in germinal center-like formation within the granulomatous lesion are frequently observed, which suggests antigen-driven B cell maturation. Wegener's autoantigen PR3, the target for autoreactive B and T cells, is expressed in granulomatous lesions. Disease progression in WG is accompanied by a profound generalized alteration of T cell differentiation with an increase of effector memory T cells (CD4(+)CD28(-)). The cytokine profile suggests an aberrant Th1-type response either to an environmental trigger and/or the autoantigen PR3 itself. Staphylococcus aureus, a risk factor for disease exacerbation, is widely present in the upper airways in WG. The Ig gene repertoire from WG lesions indicates a predominance of VH3+ B cells with affinity to PR3 as well as to the S. aureus B cell superantigen SPA. Hence, within the WG lesion, S. aureus might support the maturation of PR3-affinity B cells that enter a germinal center reaction in contact with PR3 and T cells and expand, leading to PR3-ANCA production. Thus, granulomatous lesions could represent a potential lymphoid tissue-maintaining autoantibody production rather than a simple, random leukocyte accumulation in WG.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2004

Olfactory function in patients with idiopathic Parkinson's disease: effects of deep brain stimulation in the subthalamic nucleus.

Decrease of olfactory function in patients with Parkinson's disease (PD) is a well-investigated fact. The present study aimed to investigate olfaction in PD patients with a specific focus on the effects of deep brain stimulation in the subthalamic nucleus. Eleven patients (age 42-67 years) participated in this study. Using the "Sniffin' Sticks", olfactory function was assessed based on butanol odor thresholds and the patients' ability to discriminate odors. Measures were taken with the stimulator being switched ON and OFF, respectively. While deep brain stimulation had no effect on odor thresholds, in hyposmic PD patients odor discrimination was found to be significantly higher during the ON period. This may indicate that deep brain stimulation has a positive effect on the cognitive processing of olfactory information in PD patients.

Adult↗
PubMed2004

Development and evaluation of a new ELISA for the detection and quantification of antierythropoietin antibodies in human sera.

Assays for the analysis of antierythropoietin antibodies (anti-EPO Abs) currently suffer from a high degree of nonspecificity or are cumbersome and time consuming to perform. They are therefore not well suited for the analysis of large numbers of human sera samples, a task that has become increasingly important due to an increase in the number of patients developing anti-EPO Abs. The objective of this study was to develop and validate a sensitive and specific ELISA for the determination of anti-EPO Abs that would suit these purposes. In this new double antigen bridging ELISA, anti-EPO Abs bind via one site to recombinant human erythropoietin (rhEPO)-biotin immobilized to streptavidin-coated microtiter plates (MTPs) and by a second site to rhEPO labelled with digoxigenin (DIG). The amount of bound antibody is determined using an anti-DIG antibody coupled to peroxidase. A rabbit polyclonal anti-EPO Ab purified by immunoadsorption is used as reference antibody preparation. The dynamic range of this ELISA was 1-75 ng/ml per assay calibrated with the reference antibody preparation. The assay was specific for anti-EPO Abs and did not react with other immunoglobulins (Ig) present in human serum. The lower limit of detection (LLD) of the assay was 0.5 ng/ml, and the lower limit of quantitation (LLQ) was 1.0 ng/ml. Anti-EPO Abs could be detected in the sera of pure red cell aplasia (PRCA) patients. In contrast to previous reports, no anti-EPO Abs could be detected in the sera of patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS), or in the sera of dialysis patients.

Animals↗
PubMed2004

Fully differential cross sections for photo-double-ionization of D2.

We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double-ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis. This effect is reproduced by a model in which a pair of photoionization amplitudes is introduced for the light polarization parallel and perpendicular to the molecular axis.

Journal Article↗
PubMed2004

[Laparoscopic esophagotomy without diverticular resection for treating epiphrenic diverticulum in hypertonic lower esophageal sphincter].

INTRODUCTION: As a rule, epiphrenic diverticulum occurs in combination with most diverse forms of dysfunction in the lower esophageal sphincter (LES) and/or in the esophagus itself. The main symptoms are dysphagia, pain, and regurgitation. The operation consists in myotomy, diverticulum resection, and partial fundoplication via abdominal or thoracic approach using conventional or minimally invasive technique. The main risk is postoperative suture dehiscence after diverticular resection. The present study was therefore undertaken to establish whether the operation succeeds in risk patients even without resection of the diverticulum. PATIENTS AND METHODS: In the period from 1998 to 2001, six patients were investigated preoperatively by means of esophageal manometry, endoscopy, and radiological barium swallow. The four risk patients underwent only myotomy of the LES, if appropriate, in combination with laparoscopic partial fundoplication. Resection of the diverticulum by thoracoscopy or with conventional thoracic technique was also performed in the two patients with normal risk. RESULTS: Three of the four risk patients showed normal postoperative courses after laparoscopic myotomy and rapidly became free of symptoms and were able to eat normally. One patient died perioperatively of pulmonary complications. After thoracic diverticulum resection, both patients developed postoperative suture dehiscence with a complicated course. Altogether, freedom from symptoms with regard to dysphagia and regurgitation could be attained in five out of six patients over a follow-up period of 6 to 25 months. CONCLUSION: In patients with epiphrenic diverticulum and disorder of LES function, myotomy alone without resection of the diverticulum may be sufficient to relieve or eliminate symptoms. Laparoscopy and the combination with partial fundoplication are the preferred techniques. In our opinion, this method must be considered in order to reduce the surgical risk in multimorbid and elderly patients.

Aged↗
PubMed2004

[Molecular pathology in hereditary colorectal cancer. Recommendations of the Collaborative German Study Group on hereditary colorectal cancer funded by the German Cancer Aid (Deutsche Krebshilfe)].

Although twin studies indicate that inherited genetic factors contribute to about 35% of colorectal cancers (CRC), the exact genetic background has currently been elucidated in only 5-10% of cases. These comprise several hereditary cancer predisposition syndromes that present with a high number of syn- or metachronous neoplasms within an affected person and/or family. Many of these tumors exhibit typical histopathological changes. In general, one should discriminate between cancer syndromes associated with adenomatous and non-adenomatous (i.e., hamartomatous) polyps, the latter being quite rare. The patient's age often serves as a substantial hint to hereditary cancer. The next step of diagnostic work-up includes analysis of microsatellite instability (MSI) together with immunohistochemical detection of a loss of expression in one of the most frequently affected mismatch repair genes (MSH2, MSH6; MLH1, PMS2). Finally, the molecular demonstration of a gene mutation in the blood or germline is the most expensive and tedious procedure. This requires a signed informed consent from the patient after appropriate genetic counseling.

Colonic Neoplasms↗
PubMed2004

[Triple surgery. Keratoplasty combined with cataract extraction and intraocular lens implantation].

Since the 1980s, combined perforating keratoplasty and extracapsular cataract surgery with intraocular lens implantation (triple procedure) has been performed with increasing success for patients with corneal disease and cataract. Advantages include prompt visual rehabilitation, protection of the transplanted endothelium from sequential cataract surgery, and similar up to superior functional results following triple procedures. In the following review article, the authors discuss advantages and disadvantages of triple procedures, alternative surgical techniques, problems in intraocular lens power calculation, intraoperative pitfalls, and postoperative results of combined keratoplasty, cataract removal, and intraocular lens implantation.

Cataract Extraction↗
PubMed2004

ECG-guided central venous catheter positioning: does it detect the pericardial reflection rather than the right atrium?

BACKGROUND AND OBJECTIVE: Although electrocardiography (ECG) guidance of central venous catheters (CVCs) is traditionally thought to detect the entrance into the right atrium (RA), there is little evidence in the literature to confirm this. We previously observed a high incidence of left-sided CVCs abutting the wall of the superior vena cava (SVC), even when the catheters were advanced past the point of increased P-wave amplitude. Our hypothesis was that this ECG amplitude signal is actually detecting the pericardial reflection rather than the RA. The goal of the study was to position catheter tips under ECG guidance outside the RA. METHODS: One-hundred central venous triple-lumen catheters inserted either via the right or the left internal jugular veins, respectively, were analysed in cardiac surgical patients. The position of the catheter tip was ascertained by ECG. METHOD A: A Seldinger guide-wire in the distal lumen served as exploring electrode, the respective insertion depth was recorded. METHOD B: The middle lumen (port opening 2.5 cm from the catheter tip, thus the catheter was advanced more towards the atrium) filled with a saline 10% fluid column served as the exploring electrode, and the insertion depth was recorded again. Descriptive data are given as mean+/-standard deviation. RESULTS: On average, the catheters were advanced by the expected 2+/-0.3 cm using Method B beyond the initial insertion by Method A. All 100 CVCs were finally correctly positioned in the SVC and confirmed by transoesophageal echocardiography. When chest radiography was performed after surgery not a single catheter abutted the lateral wall of the SVC. CONCLUSION: Since both methods detected the same structure, and catheters placed by Method B did not result in intra-atrial CVC tip position, the first increase in P-wave amplitude does correspond to a structure in the SVC, most likely the pericardial reflection.

Aged↗
PubMed2004

[Pulmonary Infiltrate, Pleural Effusion and IgM Macroglobulinaemia].

We report a 71-year-old mam with known IgM- Macroglobulinemia, who developed infiltrative pulmonary changes and a pleural effusion. Both, the pleural effusion and bronchoalveolar lavage revealed monoclonal IgM positive B-lymphocytoes. Transbronchial biopsies showed tissue infiltrates of lymphoplasmocytic cells, consistent with a pleuropulmonary manifestation of Morbus Waldenstroem. Bone marrow and gastrointestinal involvement could be excluded, and the diagnosis of a primary pulmonary immunocytoma was made. The patient underwent partial lung resection with removal of the affected lung tissue. Pleuropulmonary changes in patients with IgM-Macroglobulinaemia or Morbus Waldenstroem may be due to pulmonary involvement by the hematological disease.

Aged↗
PubMed2004

[Comparison of different methods for pupillometry for mesopic and scotopic conditions].

BACKGROUND: The aim of the study was to compare different methods for pupillometry, namely the Goldmann perimeter (gp), the Colvard pupillometer (cp) and the Procyon Video pupillometer (pvp). For the pvp three different illuminations were available: mesopic high, mesopic low, and scotopic. PATIENTS: The size of the pupil was measured in 100 eyes (50 healthy subjects) with the three different methods. We examined 29 females (58 %) and 21 males (42 %) with an average age of 25.16 years, ranging from 18 to 30 years. RESULTS: For the Goldmann perimeter, a mean pupil diameter of 4.39 mm +/- 0.62 mm was found under mesopic conditions (1.40 lux). For the Colvard pupillometer for scotopic conditions (0 lux), a mean pupil diameter of 6.80 mm +/- 0.81 mm was found. For pvp the pupil diameter ranged from 7.06 mm +/- 0.71 mm for scotopic (0.04 lux), over 6.24 mm +/- 0.80 mm for mesopic low (0.40 lux) to 4.65 mm +/- 0.73 mm for mesopic high conditions (4.00 lux). CONCLUSION: The comparison of the results showed a high correlation between the Goldmann perimeter and the Procyon Video Pupillometer for mesopic high with a minimum difference of 0.25 +/- 0.69 mm. By addition of 2.67 mm to the mesopic measurement of the Goldmann perimeter, the results for the Procyon Video pupillometer at the scotopic level, by addition of 2.4 mm the scotopic measurement of the Colvard pupillometer could be achieved.

Adolescent↗