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Biomedical subjects

S Baur

Publications and source records attributed to S Baur.

At least 19 recordsLinked to original sources

Teleradiology applications with DICOM-e-mail.

For the connection of several partners to a Dicom-e-mail based teleradiology network concepts were developed to allow the integration of different teleradiology applications. The organisational and technical needs for such an integration were analysed. More than 60 institutions including 23 hospitals in the Rhein-Neckar-Region, Germany were connected. The needed functionality was grouped in six teleradiology applications (emergency consultation, tele-guided examinations, expert consultations, cooperative work, scientific cooperations and homework with on call services) and their technical and organisational needs according to availability, speed of transfer, workflow definitions and data security needs was analysed. For the local integration of teleradiology services the setup and workflow is presented for a standalone teleradiology workstation and a server based teleradiology gateway. The line type needed for different groups of applications and users is defined. The security concept and fallback strategies are laid out, potential security problems and sources of errors are discussed. The specialties for the emergency teleradiology application are presented. The DICOM-e-mail protocol is a flexible and powerful protocol that can be used for a variety of teleradiology applications. It can meet the conditions for emergency applications but is limited if synchronous applications like teleconferences are needed.

Computer Security↗

Determination of the fertile window: reproductive competence of women--European cycle databases.

OBJECTIVES: The objective of the present paper is to review the main results of recent European cycle databases on ovulation detection and determination of the fertile window performed by the women themselves. METHODS: The ongoing German Long-term Cycle Database currently comprises 32788 prospectively collected cycle charts of 1551 women, the I European Cycle Database (10 countries) 1328 women/19048 cycles, the II European Cycle Database (six countries) 782 women/6724 cycles, and the World Health Organization Database (one European country) 234 women/2808 cycles. The women record cycle parameters (cervical mucus changes, temperature rise, etc.), family planning intention and sexual behavior. RESULTS: With the symptothermal method of natural family planning it has become possible to determine the fertile window in order to avoid pregnancy with a method effectiveness of 0.3%. According to a small sub-study, the ovulation time observed by the women themselves correlates closely with ovulation detected by ultrasound and measurement of luteinizing hormone (correlation within 1 day in 89% of the 62 cycles). Fertility awareness methods can be integrated into the management of sub-fertility. They seem to shorten the time to pregnancy. CONCLUSIONS: Self-observation of the fertile window puts women into a position to develop a high level of reproductive competence that could be used much more in different areas than is currently the case.

Adult↗

Successful treatment of postoperative pyoderma gangrenosum with cyclosporin.

Postoperative pyoderma gangrenosum (PPG), also known as postoperative progressive gangrene of Cullen, is a rare and rapidly evolving complication of surgical procedures. Since the first description by Cullen in 1924 (Surg Gynecol Obstet 1924; 38: 579-582) various case reports have been published. Even in typical cases PPG is often misdiagnosed and therefore wrongly treated; the unknown aetiology makes treatment difficult. The therapies used for pyoderma gangrenosum include systemic corticosteroids, azathioprine, dapsone, mercaptopurine, sulphasalazine, sulphapyridine, thalidomide, cyclophosphamide, clofazimine, isotretinoin, immunoglobulins and cyclosporin. We report on two patients with PPG following breast surgery who were successfully treated with low-dose cyclosporin (2.5-5 mg/kg per day).

Adult↗

Training intensity influences leptin and thyroid hormones in highly trained rowers.

Leptin (L) is associated with body-weight-regulating and adipostatic functions. Its receptors also may be found centrally. Thyroid hormones regulate metabolic processes mainly by binding at peripheral receptors. Aim of this study was to show if there is a link between those central and peripheral regulation systems and to investigate the influence of different training intensities on L and the hypothalamic-thyroid-axis (HTA) in highly trained rowers. Six rowers (18.9 +/- 2.6 y; BMI 22.8 +/- 2.1 kg/m (2)) undertook high intensity resistance training (RT) for three weeks followed by three weeks of endurance training (ET). After each training cycle the subjects had one week for recovery (R1, R2). Blood samples were taken before and at the end of RT, R1, ET and R2. L, thyroid stimulating hormone (TSH), free T3 (fT3) and free T4 (fT4) were measured. After RT, a significant reduction in L, TSH and fT3 was found (p < 0.05). fT4 was unchanged. L remained decreased until the end of R1. After ET, a significant increase of TSH was found. L correlated to basal TSH levels (r = 0.49, p = 0.006) during R. BMI and body fat were unchanged throughout the study and were not correlated with hormonal levels. We speculate a high energy flux during intensified training (RT) caused the decrease of L and the HTA, independent of BMI or body fat. Thus, we conclude a depression of L and HTA is associated with training intensity.

Adolescent↗

Epithelial-mesenchymal transformation is the mechanism for fusion of the craniofacial primordia involved in morphogenesis of the chicken lip.

We have previously demonstrated that epithelial-mesenchymal transformation (EMT) brings about TGF beta 3-induced confluence of craniofacial primordia that derive from the maxillary processes and give rise to the avian palate. The upper lip of the chick embryo forms by confluence of primordia also derived from the maxillary processes, but in this case, they fuse with the intermaxillary segment of the nasofrontal process. Here, we ask whether the bilateral epithelial seams formed when these primordia contact each other in vivo are removed by apoptosis (as formerly was believed to occur in developing palate) or by EMT. We found that, as is the case in the palate, the periderm of the two-layered embryonic epithelium begins to slough shortly before these primordia fuse, bringing the basal epithelial cells into close contact. We show by TUNEL staining and confirm by TEM that apoptosis occurs only in periderm. TEM reveals that basal epithelial cells contacting each other to form the midline seam produce numerous desmosomes with each other. Then, basement membrane begins to disappear, numerous filopodia extend from the basal surfaces of epithelial cells, the space between them enlarges, and the seam breaks apart, leaving mesenchymal cells in its wake. Transformation of the carboxyfluorescein (CCFSE)-labeled epithelial seam is demonstrated in vivo by detection of CCFSE bodies in mesenchymal cells that replace it. This demonstration of EMT in avian lip development lays important groundwork for understanding the causes of human cleft lip and analyzing the mechanism of action of growth factors, such as SHH and BMPs, that have been shown (J. A. Helms et al., 1997, Dev. Biol. 187, 25-35) to be involved in avian lip confluence.

Animals↗

Intracranial haemorrhage following lumbar myelography: case report and review of the literature.

We describe a subacute intracranial subdural haematoma following lumbar myelography. This rare but potentially life-threatening complication has been reported both after lumbar myelography and following lumbar puncture for spinal anaesthesia. We review 16 previously reported cases of intracranial haemorrhage following lumbar myelography, and discuss the pathogenesis. In all reported cases post-puncture headache was the leading symptom and should therefore be regarded as a warning sign.

Cerebral Angiography↗

A new cortical electrode for neuronavigation-guided intraoperative neurophysiological monitoring: technical note.

Intraoperative neurophysiological mapping and monitoring of eloquent brain areas can be combined with image-guided localisation to enhance the safety and efficacy of surgical procedures in the motor cortex. We designed a new type of cortical electrode which can be repeatedly placed on the cortical surface and allows accurate and reproducible stimulation by means of a navigation pointer. The newly designed device consists of a monopolar electrode contact for direct cortical stimulation, housed in a holder which allows placement, easy removal, and precise repeated placement of a surgical navigation pointer. It can be used for navigation-guided, high-frequency anodal monopolar cortical stimulation (MCS) for the mapping of eloquent cortex, and for monitoring of motor pathways. While the cortex is stimulated, compound muscle action potentials (CMAP) are recorded from muscles of the contralateral extremities and are assessed both qualitatively and quantitatively. When the device is used in combination with intraoperative navigation, the stimulation sites may optionally be registered or displayed on the system monitor. This allows repeated pinpointing and obviates the need for strip or grid electrodes in the operative field; although such electrodes may be useful for continuous monitoring, they often are in the surgeon's way. In addition, the primary and supplementary motor cortex can be mapped by determining the location of the sites of stimulation on surface-projected images of the cerebral cortex.

Brain Mapping↗

Motor cortex fatigue in sports measured by transcranial magnetic double stimulation.

PURPOSE: Besides peripheral mechanisms, central fatigue is an important factor limiting the performance of exhausting exercise in sport. The mechanisms responsible are still in discussion. Using noninvasive transcranial magnetic stimulation (TMS) in a double-pulse technique, we sought to assess fatigue of the motor cortex after exhaustive anaerobic strain. METHODS: 23 male subjects (22-52 yr) taking part in the study were requested to accomplish as many pull-ups as possible until exhaustion. The amount of physical lifting work was recorded. Before and immediately after the task, intracortical inhibition (ICI) and facilitation (ICF) were measured by a conditioned-test double-pulse TMS method for the right brachioradialis (BR) and abductor pollicis brevis muscle (APB). RESULTS: After exercise, ICF was significantly reduced in the BR but not in the APB. ICI was not altered. Changes tended to normalize within 8 min after the task. The amount of lifting work accomplished showed significant correlation to the values of ICF reduction (r = 0.73). Moreover, the baseline values of ICF before exercise were also significantly correlated to the lifting work (r = 0.63). CONCLUSIONS: Because double-pulse TMS gives access to the motor cortex independently of spinal or peripheral mechanisms, reduced ICF reflects decreased excitability of interneuronal circuits within the motor cortex. We suggest that ICF measures motor cortex fatigue after exhausting strain specifically for the muscles performing the task. Gamma-aminobutyric acid (GABA)-ergic neurotransmission is possibly involved in the mechanisms mediating central fatigue. Double-pulse TMS may be a useful tool in the control of training in sports as well as in the detection of pathological central fatigue in overreaching and in the prevention of overtraining.

Adult↗

Collagen XII mutation disrupts matrix structure of periodontal ligament and skin.

Collagen XII has been postulated to organize the extracellular matrix (ECM) architecture of dense connective tissues such as the periodontal ligament (PDL) and skin. The objective of this study was to test this hypothesis in transgenic mice carrying a dominant interference mutation of collagen XII. The truncated alpha1(XII) collagen minigene construct MXIINC3(-), driven by the mouse alpha2(I) collagen promoter, was prepared and used to generate transgenic mouse lines. The PDL matrix fibers of molar teeth lost the ordered architecture characteristic of ligament tissue without noticeable inflammation. Cellular cement appeared to be disrupted at the PDL insertion. By confocal laser scanning microscopy, the PDL of transgenic mice demonstrated swollen and irregularly arranged collagen fibers associated with internal porosity. The skin of transgenic mice revealed the lack of matrix fiber structure in the papillary dermis. These results indicated that the dominant interference mutation of collagen XII disorganized the ECM architecture of PDL and skin.

Animals↗

Expression of myosin heavy chain isoforms in skeletal muscle of patients with peripheral arterial occlusive disease.

PURPOSE: Peripheral arterial occlusive diseases (PAODs) not only compromise blood flow but lead to a series of subsequent metabolic and structural changes in the relevant muscles. Changes in myofibrillar proteins (eg, of myosin heavy chain [MHC] isoforms), one of the determinants of muscle structure as well as of muscular function, have not been reported in patients with PAOD and were therefore the aim of this study. METHODS: Thirteen consecutive patients with PAOD were examined (clinical stage according to Fontaine II, three patients; III, three patients, and IV, seven patients) and compared with five age-matched control patients who had been in traffic accidents. A calf muscle sample (gastrocnemius muscle) in the ischemic region was taken for MHC isoform analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis and silver stain, and the relative content of MHC isoforms was measured. RESULTS: Compared with the control patients, there was no significant change of MHC isoforms in patients with PAOD II. In patients with PAOD III, MHC IIb decreased significantly (P <.05) although MHC IIa remained unchanged; in patients with PAOD IV, both MHC IIa and IIb decreased significantly (P <.05). Accordingly, there was a progressive increase of the relative amount of MHC I with more critical ischemia in PAOD. CONCLUSION: In patients with PAOD, the content of MHC II decreased with a higher grade of ischemia. That seems to be consistent with an increased resistance to ischemia for myosin isoforms in the order of I more than in IIa more than IIb. Whether the decrease of MHC II in patients with PAOD is related to atrophy of muscle fibers or to muscle-fiber transition must be investigated further.

Aged↗

Human skeletal muscle HSP70 response to training in highly trained rowers.

Previous studies have demonstrated exercise-induced heat shock protein 70 (HSP70) in animals. The purpose of this study was to investigate human skeletal muscle HSP70 response to rowing training. Ten male rowers trained for 4 wk with different forms, durations, and intensities of exercise. Biopsy was performed in the right musculus vastus lateralis before training and at the end of each week. HSP70 in 5 microg of total protein from the muscle sample was determined by using Western blot and immunodetection with chemiluminescence technique, by means of laser densitometer referring to a series of known standard HSP70. Compared with pretraining (100%), HSP70 increased during training (181, 405, 456, and 363% from the first to fourth training week, respectively) with the maximum HSP70 production at the end of second training week. Thus HSP70 is induced in highly trained human muscle by long-term training.

Adolescent↗

Human papillomavirus detection in cervical intraepithelial neoplasia by the second-generation hybrid capture microplate test, comparing two different cervical specimen collection methods.

BACKGROUND: The second generation Hybrid Capture microplate-based human papillomavirus (HPV) test (HC II) was examined to determine its sensitivity for identification of cervical intraepithelial neoplasia (CIN) by two different cervical specimen collection methods. OBJECTIVES: A cohort of 115 women with a mean age of 34.6 years (SD 9.1), referred to colposcopy with a history of abnormal cytology, was studied to compare HPV prevalence and viral load in low grade CIN vs. high grade CIN. STUDY DESIGN: Prior to the application of acetic acid, cervical specimens were obtained by either method 1 or 2, as follows: method 1: A cotton-tipped swab was applied to the ectocervix and endocervix for a Papanicolaou (Pap) smear. Next, a special cone-shaped cervical brush was applied to the endocervix, the ectocervix, and to the posterior vaginal vault and suspended in 1.0 ml of transport medium for HPV testing. Method 2: a Pap smear was taken with a cyto standard cylindrical cytology brush from the endocervix, and ectocervix, and the remaining cells were suspended in 3 ml phosphate-buffered saline (PBS) for HPV testing. Next, a Dacron-tipped swab was used to take a specimen from the ectocervix and posterior fornix and suspended in the same PBS solution.

Adult↗

[Papular exanthema in systemic histoplasmosis and HIV infection].

A 34-year-old HIV-infected African woman developed fever, weight loss and widespread papules on her trunk, arms and face. Skin biopsy and culture revealed histoplasmosis caused by Histoplasma capsulatum varietas capsulatum (American histoplasmosis). Even though antimycotic treatment and intensive care were started immediately the patient died because of the systemic mycosis within a few days. Histoplasmosis is a rare disease in Europe but endemic in some areas of the USA (e.g., Ohio, Mississippi) and of Africa. Additionally histoplasma capsulatum varietas duboisii is endemic in Central and South Africa.

AIDS-Related Opportunistic Infections↗

Effect of "living high-training low" on the cardiac functions at sea level.

Living high-training low (LHTL), living at high altitude and training at sea level, is reported to be beneficial in enhancing physical performance. Effect of LHTL on cardiac function which is one of major determinants in performance, however, was not examined. To address this issue, 21 well-trained triathletes divided into control (n = 10, living and training at sea level) and LHTL group (living at 1980 m altitude > or = 12 hrs/day and training at sea level) were Doppler echocardiographically examined before and at the end of the two-week program. Heart rate and blood pressure did not change in both groups. At end of the training, left ventricular endsystolic diameter of LHTL group was smaller than that of controls (32 vs 34 mm, P < 0.05). Shortening fraction and ejection fraction in LHTL group increased by 9% and 17 %, respectively, P < 0.05. Preejection period/ejection time was more greatly reduced in LHTL group (P < 0.05). Stroke volume and cardiac output in LHTL increased. Diastolic function was not significantly affected by LHTL. These results suggest that LHTL produced an improvement of systolic function underlined by incremented left ventricular contractility, which might be associated with increased beta-adrenergic receptor or an improved myocardial energy utilization.

Adult↗

Synthesis and evaluation of a novel series of pyrrolizine derivatives as dual cyclooxygenase-1 and 5-lipoxygenase inhibitors.

The aim of our study was to investigate structure activity relationship following the replacement of the 6-phenyl substituent at the 6,7-diaryl-2,3-dihydropyrrolizine template by various heteroaromatic residues. In this context we developed a new, efficient, and highly sensitive test method for the screening of dual cyclooxygenase-1 (COX-1) and 5-lipoxygenase (5-LOX) inhibitors. We used human platelets as a source of COX-1 and human PMNLs as a source of 5-LOX. Both cell types were isolated from the same volume of blood. PGE2 and LTB4 respectively were determined by highly selective and sensitive ELISA kits, using monoclonal antibodies. For a single determination at most 0.5 mL whole blood is needed.

Arachidonate 5-Lipoxygenase↗

Monitoring high-intensity endurance training using neuromuscular excitability to recognize overtraining.

The minimal rectangular current pulse that produces a single contraction of reference muscles at different pulse durations has been recommended as a marker of the neuromuscular excitability (NME) of skeletal muscles. NME is improved in well-trained, non-fatigued endurance athletes and deteriorates after prolonged heavy exercise and high-volume overtraining. The hypothesis was tested that a deterioration in NME also indicates an early stage in the overtraining process during high-intensity endurance training. Six subjects participated for 40-60 min per day in a 6-week, 6-days-per-week, intensive, steady-state and interval training program using a cycle ergometer. Training was stopped each day on volitional exhaustion. On day 7 of each week training was of low intensity for about 30-40 min. Submaximum and maximum power output were significantly increased after 3 weeks, but there was no further improvement, rather a deterioration after week 6 compared to week 3. Even after 2 weeks of regeneration no supercompensation was evident, rather a decrease in maximum power output. NME was slightly improved after 3 weeks, but deteriorated after 6 weeks, and was again normalized after 2 weeks of regeneration. The discrepancy between normalization of NME and still-deteriorated performance ability after 2 weeks of regeneration reflects additional significant, and probably central mechanisms that explain persistent performance incompetence. Deterioration in NME may indicate an early stage in the overtraining process during high-volume as well as high-intensity endurance overtraining, but normalization does not necessarily indicate sufficient regeneration.

Adult↗