Search PubMed⌕ Search

Biomedical subjects

U Schneider

Publications and source records attributed to U Schneider.

At least 37 records · Page 2Linked to original sources
PubMed2004

Fetal MCG and fetal MEG measurements with a 3-channel SQUID system.

Since the high costs of common large array SQUID system may hinder widespread application of fetal magnetoencephalography (fMEG) and magnetocardiography (fMCG), we intended to investigate a small non-commercial 3-channel SQUID system. The system comprises 3 axial first order gradiometers with 7 cm base length, 2 cm diameter and 2x2 windings of niobium wire, dc-SQUIDs (UJ-111), and current locked mode SQUID electronics that form an equal length triangle (22.5 mm). The system is mounted in a Cryostat BFH-7 model 16 with 5 mm "warm"-"cold" distance. System noise is about 10 fT/Hz1/2. The fMEG and fMCG were recorded between 29 - 40 weeks of gestation after sonographic localization of the fetal head and heart using a 31-channel biomagnetometer (Philips) and the 3-channel-system, both in the same magnetically shielded room. The fMEG was recorded continuously over 500 sec (500 auditory stimuli, 100 dB SPL, 500 Hz, 50 ms, ISI 0.8-1.2/1.6-2.4 sec, trigger channel, maternal ECG lead, sampling rate 1 kHz). The fMCG was recorded over a period of 5 minutes after dewar readjustment. The detection rates of cortical auditory evoked responses (CAER) reached 100 % for both systems. Cross confirmation of the components was difficult and may have uncovered false positive component detection. The fMCG was characterized by a systematic increase in SNR under application of the smaller device. The small size array provides a profitable alternative for the fetal applications.

Cardiotocography↗
PubMed2004

Regulation of the Borna disease virus polymerase complex by the viral nucleoprotein p38 isoform. Brief Report.

Borna disease virus (BDV) polymerase can be reconstituted by co-expression of the viral genes N, P and L. N codes for two proteins, p39 and p38, resulting from alternative translation initiation. Using a viral minireplicon system we observed that unlike p39, p38 was almost completely inactive when expressed with P and L alone. Since BDV polymerase requires a 10-20 fold excess of N protein over P for high activity, we determined whether p38 might serve as buffer that influences the viral N:P ratio. We demonstrate that p38 efficiently rescued BDV polymerase activity in cells expressing unfavorably high amounts of P.

Borna disease virus↗
PubMed2004

First spinal axis segment irradiation with spot-scanning proton beam delivered in the treatment of a lumbar primitive neuroectodermal tumour. Case report and review of the literature.

Primary intraspinal primitive neuroectodermal tumour (PNET) is a rare tumour entity. The optimal therapeutic management is unclear but, in general, this tumour is treated with surgery followed by radiotherapy and chemotherapy. Proton beam radiation therapy (PT) offers superior dose distributional qualities compared with X- or gamma rays, as the dose deposition occurs in a modulated narrow zone called the Bragg peak. As a result, organs at risk are optimally speared. Here, we present a patient treated with the first spinal axis segment irradiation using spot-scanning PT with a single field, combined with conventional cranio-spinal axis radiotherapy after surgery and chemotherapy, and an extensive review of the literature outlining the clinical features and treatment modality of spinal PNET.

Adult↗
PubMed2004

Sentinel lymph node biopsy in rectal cancer--not yet ready for routine clinical use.

BACKGROUND: The value of sentinel node biopsy in visceral cancers is uncertain. We evaluated the feasibility and utility of radiocolloid lymphatic mapping and selective lymph node sampling in patients with rectal cancer. METHODS: Forty-eight patients with rectal cancer were investigated. Thirty-seven patients had already undergone preoperative radiochemotherapy for locally advanced tumors. Eleven patients underwent primary surgery. An endoscopic injection of 1 mL technetium 99m-sulfur-colloid into the peritumoral submucosa was performed 15 to 17 hours before surgery. Ex vivo identification of the nuclide-enriched "sentinel lymph nodes" (SLNs) was performed using a hand-held gamma-probe. The selected SLNs were then carefully and systematically examined using serial sections and immunohistochemistry. RESULTS: One or more SLNs were found in 46 of the 48 patients. The SLN detection rate was 96%. Sixteen of the 48 patients had lymph node metastases (35%). In 7 of the 16 patients, the SLNs correctly represented the nodal status. In 9 of the 16 patients, the SLN was tumor-free whereas non-SLN harbored metastases. This result represents a sensitivity of only 44%, and a false-negative rate of 56%. Further analysis showed that the method correctly predicted the nodal status only in the small subgroup of 5 patients with early cancer without preoperative radiation. In 4 patients, juxtaregional lymph nodes were excised on the basis of intraoperative radiocolloid detection, leading to upward staging in 1 patient. CONCLUSIONS: Sentinel lymph node biopsy using the radiocolloid technique with ex vivo lymph node identification shows a relatively high detection rate; however, the sensitivity in patients with locally advanced/irradiated rectal cancer is low. Nevertheless, the detection of juxtaregional metastases can improve staging in some patients. Further studies should focus on patients with early rectal cancers where the data were more promising.

False Negative Reactions↗
PubMed2004

Psychotic disorders and gonadal function: evidence supporting the oestrogen hypothesis.

OBJECTIVE: The aim of this study was to further evaluate the oestrogen hypothesis of schizophrenia, which postulates low oestradiol levels to be a risk factor for these disorders. A possible influence of neuroleptic-induced hyperprolactinaemia was to be addressed. METHOD: Sex hormones were measured and cycle phase assessed in 50 acutely psychotic women on admission and for four consecutive weeks as well as in three control groups. RESULTS: Psychotic women were more likely to be admitted during a low oestrogen phase of their cycle and exhibited markedly reduced oestradiol levels, compared with 23 healthy controls, as well as 50 women suffering from other psychiatric disorders. Oestradiol variability was reduced over the menstrual cycle in women suffering from psychotic disorders. CONCLUSION: These results support the oestrogen hypothesis. Hyperprolactinaemia due to neuroleptic treatment does not appear to account for the findings.

Adult↗
PubMed2004

[AWMF-guideline: disorders related to cannabis].

Actually, guidelines for treatment of substance-related disorders were written under the overall control of the DG-Sucht e. V. and the DGPPN e. V. This appears within the framework of the Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaft (AWMF). The leading objective of these guidelines is the description of the current scientifically proven and evidence-based medicine in addiction to derive recommendations to therapy. In this context, the guideline for treatment of cannabis-related disorders is introduced.

Cannabis↗
PubMed2004

Treatment of alcohol withdrawal: chlormethiazole vs. carbamazepine and the effect on memory performance--a pilot study.

Although relatively little attention has been paid to the question how acute alcohol withdrawal might affect cognitive functions, this factor remains of particular interest because it influences psychotherapeutic treatment during detoxification. The clinical outcome and neuropsychological state of 37 inpatients with alcohol withdrawal was investigated in a randomized single-blind approach. Two different medical strategies [chlormethiazole (CMZ) vs. carbamazepine (CBZ)] in the treatment of inpatients with alcohol withdrawal syndrome were compared. Among comparable groups (related to gender, age, initial alcohol level, severity of abuses, severity of initial withdrawal symptoms such as tremor, perspiration, psychomotor agitation, hallucinations, orientation, intelligence, patient demographics), CBZ is just as potent as CMZ in therapy of withdrawal symptoms (circulatory function, vegetative function, psychomotor activity). Patients in both groups showed initial impairments in some neuropsychological tests (d2, Zahlen-Verbundings test, Beck Depression Inventory, Anxiety Sensitivity Index) with significant improvement during detoxification. Additionally, CBZ-treated patients showed significantly better verbal memory performance during the first days of treatment. Without any addictive potential, CBZ therapy could be very supportive in alcohol detoxification. In addition a higher verbal memory performance state could be favourable for a psychotherapeutic approach.

Adult↗
PubMed2004

Molecular response of gastrointestinal stromal tumour after treatment with tyrosine kinase inhibitor imatinib mesylate.

Bleeding from the tumour site is not uncommon during the treatment of gastrointestinal stromal tumours with imatinib mesylate. It might represent an early reaction of highly vascularised tumour tissue to receptor blockade. Although often requiring emergency surgery, this is not necessarily a deleterious sign. Slow tumour regression and cystic tissue alteration may follow. Using immunohistochemistry and consecutive resection specimens, it was shown that the number of mitoses decreased significantly and MIB-1 as a marker of cell proliferation could no longer be detected. In the few tumour cells still present, the magnitude of expression of the pathognomonic marker CD117 remained unchanged. Decreases in the size of tumours responding to imatinib mesylate cannot be expected to meet the World Health Organisation or RECIST (response evaluation criteria in solid tumours) criteria. This underlines the necessity of functional imaging by positron emission tomography, contrast enhanced magnetic resonance imaging, or magnetic resonance spectroscopy to assess the response to treatment.

Adult↗
PubMed2003

Reactive knee and ankle joint arthritis: abnormal manifestation of Legionella pneumophila.

This case report demonstrates that active legionellosis is not always characterised by pulmonary symptoms and specific radiomorphological findings. Whereas the initial clinical presentation, as described in the literature, includes fever, cough, expectoration, extrapulmonary organ changes or typical laboratory findings, atypical manifestations such as reactive arthritis must be considered.

Adult↗
PubMed2003

Patellar hypertension syndrome in adolescence: a three-year follow up.

INTRODUCTION: Anterior knee pain is one of the major causes of knee pain in an adolescent population. It has been suggested that raised intraosseous pressure may play an important role in the development of anterior knee pain in the young patient. MATERIAL AND METHODS: A prospective clinical multicentre study with 27 adolescent patients presenting with anterior knee pain was performed. After failure to respond to conservative treatment, all patients agreed to undergo minimally invasive intraosseous pressure measurements in local anaesthesia. All 27 patients demonstrated a positive "pain provocation test" as a response to increased intrapatellar pressure and were decompressed with a new intraosseous drilling technique. RESULTS: The repeat intraosseous pressure measurement in 27 patients 1 year postoperatively revealed a significant reduction from 43.3+/-13.4 preoperatively to 24.1+/-4.2 mmHg (p<0.001). The pain relief was documented in the form of a reduced VAS from 7.6+/-1.4 to 2.1+/-1.1 cm after 3 years (p<0.001). CONCLUSION: Patients with anterior knee pain and a positive "pain provocation test" were diagnosed as suffering from a hypertension syndrome of the patella. We conclude that simple extraarticular patellar decompression may offer a valuable new form of treatment in this select group of adolescent patients with anterior knee pain.

Arthralgia↗
PubMed2003

Treatment of penile curvature--how to combine the advantages of simple plication and the Nesbit-procedure by superficial excision of the tunica albuginea.

Different treatment options for penile curvature exist, such as the Nesbit procedure with complete excision of the tunica albuginea or the simple plication. We prefer a modification with only superficial excision, not opening the corpora cavernosa. From January 1997 to June 2000, 68 patients were treated surgically due to penile curvature. Data was obtained from 48 patients by telephone interview. The mean penile deviation was 46 degrees. Excision of the tunica was performed only superficially and non-absorbable inverted sutures were used. The mean follow-up time in this study was 25 months. A total of 36 (75%) patients were satisfied postoperatively, 12 were unsatisfied. Eleven (23%) patients described a complete straightening, 37 (77%) a rest-curvature of 5-50 degrees (mean 14 degrees ) and 21 (44%) described a shortening of 0.5-5 cm (mean 1.2 cm). Six patients reported a recurrence. No new erectile dysfunction occurred. Superficial excision of the tunica albuginea offers the advantage of tissue-contraction due to scarring without destroying the integrity of the corpora, leading in combination with non-absorbable inverted sutures to good functional and cosmetic results.

Adolescent↗
PubMed2003

[Lymphatic mapping and sentinel lymph node biopsy in gastric cancer].

INTRODUCTION: Lymphatic mapping and the sentinel lymph node (SLN) concept has been validated in malignant melanoma and breast cancer.However, the application for other solid tumors is still controversial. One of the most promising approaches is selective lymph node staging in gastric cancer.The presented pilot study evaluated the feasibility of the radiocolloid technique in gastric cancer patients and its value in predicting a positive nodal status. PATIENTS AND METHODS: Fifteen patients with gastric cancer (u T(1-3)) underwent endoscopic submucosal injection of 0.4 ml 60 MBq (99m)Tc-Nanocis around the tumor 17 (+/-3) h prior to surgery. After laparotomy the activity of all 16 (JGCA) lymph node stations was measured by a handheld probe. All patients underwent standard gastrectomy with systematic D2 lymphadenectomy. After resection the site was scanned for residual activity. All sentinel lymph nodes (SLN's) were removed ex vivo from the resected specimen and processed for intensified histopathologic assessment including serial sections and immunohistochemistry. RESULTS: In 14 of 15 patients at least one or more SLN's were obtained (93%), the median number of SLN's was 3 (1-5). Of the 14 patients, 9 revealed lymph node metastases. In eight of the nine patients the sentinel node(s) correctly predicted metastatic lymph node invasion. In five cases the lymph node station with positive sentinel node(s) was the only positive node station resulting in a sensitivity of 8/9 (89%). In one case immunohistochemical staining revealed micrometastases leading to an upstaging in 1/6 of the initially nodal-negative patients. CONCLUSION: Lymphatic mapping and sentinel node biopsy using the radiocolloid technique is feasible in gastric cancer. Limited results indicate a correct prediction of the nodal status and the potential of upstaging.Further studies seem to be justified to evaluate the clinical impact of the method.

Aged↗
PubMed2003

[Integration of periosteum covered autogenous bone grafts with and without autologous chondrocytes. An animal experiment using the Göttinger minipig].

Autologous osteochondral transplantation has the major disadvantage of significant damage to a healthy joint surface at the donor site. The purpose of this study was to examine the effect of autogenous chondrocytes injected into the periosteum of autologous bone grafts in order to provide an alternative method for cartilage repair. A total of 22 Göttinger minipigs were operated twice on both knees. The first operation served for cartilage biopsy for the chondrocyte culture. During the second operation an osteochondral defect was created in the medial facet of the trochlear groove. The defect was treated differently with an autologous cortico-cancellous bone cylinder,harvested from the proximal tibia.Group A: untreated defect (control);B: bone-graft;C: bone-graft covered with periosteum; D: bone-graft with periosteum and injected autologous chondrocytes. The animals were killed after 6, 12, 26 and 52 weeks. The regenerated areas were evaluated macroscopically, tested biomechanically (long-term specimens; indentation-test) and a histological, blind evaluation was carried out according to a semi-quantitative scoring system. The periosteum covered bone cylinders in Groups C and D showed good repair of the bone and cartilage defect. The repaired tissue consisted predominantly of fibrocartilage with the partial formation of hyalin like tissue. The regenerated areas were integrated with the adjacent cartilage and were biomechanically superior when compared with the other groups. The additional injection of chondrocytes did not produce significantly better results. Our findings suggest that the transplantation of periosteum-covered bone cylinders may provide an alternative method for treating chondral and osteochondral defects and can be recommended for filling large donor site defects in joint surgery. The additional transplantation of chondrocytes does not seem to be justified.

Animals↗
PubMed2003

[Epidemiology and therapy of Lyme arthritis and other manifestations of Lyme borreliosis in Germany: results of a nation-wide survey].

AIM OF THE STUDY: Only little is known about the epidemiology of Lyme borreliosis in Germany. As an example, it is still unclear if there are regional differences in the incidence of Lyme disease in general or of certain clinical manifestations like Lyme arthritis. Moreover, standardization of diagnostic or therapeutic procedures does not exist. Therefore, a Germany-wide questionnaire-based survey was conducted in order to achieve more epidemiological data and to obtain more information about the diagnostic and therapeutic approaches of general practitioners and specialists. METHODS: A self-designed questionnaire was distributed along with two editions of the journal "Deutsches Arzteblatt" (which is delivered to every physician in Germany) and additionally by a pharmaceutical company. During the collection period from March 1, 1998 to February 28, 1999, patients with Lyme disease were reported and information was given about site of infection, diagnostic procedures, clinical symptoms, treatment, and outcome. RESULTS: Altogether 3935 patients were reported. Their mean age was 43.4 years with the peak incidences around the ages of 10 and 60 years. 37.3% of the questionnaires were sent in by general practitioners, 17.6% by dermatologists, 15.7% by pediatricians, 9.7% by internists, and 2.7% by neurologists. 83% of the patients did not have a special infecion risk. The most frequent clinical Lyme manifestation was erythema migrans (EM), which occurred in 50.9% of the patients. 21.3% suffered from general symptoms. Of special interest, 24.5% of the patients had Lyme arthritis (14.7% mon- or oligoarthritis, 9.8% polyarthritis). Therefore, arthritis was more frequently reported than neuroborreliosis (18.4%). Only 16% of the neuroborreliosis patients and 32% of the arthritis patients remembered having had an EM. 189 patients (4.8%) with lymphadenosis cutis benigna and 100 patients (2.5%) with acrodermatitis chronica atrophicans were reported. In 80.4% of the patients, positive Lyme serology was detected. In a few cases, the diagnosis was established by isolation of borreliae, PCR or histology. 3754 patients were treated by antibiotics. The most frequently used compounds were doxycycline (50.4%), followed by ceftriaxone (22.4%), amoxicillin (13.6%), penicillin (7%), and erythromycin (4.2%) with differences depending on clinical manifestations and specialization of the prescribing physician. In less than 10% of the cases, not evaluated or recommended therapeutic procedures were performed. DISCUSSION: Lyme disease is endemic throughuot Germany. The most frequent manifestations are EM, followed by Lyme arthritis and neuroborreliosis. Less than one third of patients suffering from disseminated or chronic Lyme disease remembered an EM. Most of the physicians taking part in this survey follow treatment recommendations concerning choice of antibiotics and treatment durations.

Adolescent↗
PubMed2003

Titer determination of Ad5 in blood: a cautionary note.

Recombinant adenoviruses are presently the most efficient in vivo gene transfer system available. Targeting single organs or large tumors by adenoviral vectors requires an intravascular route of application. During the first pass of viral particles through the vascular bed of the target tissue, virus uptake is not quantitative and indefinite amounts of particles leak into circulation. To determine the amount of leaking particles and to calculate organ-specific uptake (in-/outflow ratio), it is necessary to titrate virus particles directly in blood. In preclinical and clinical trials titration is currently mostly done with blood plasma instead of full blood. However, this technique provides valid results only as long as there is no affinity between adenovirus particles and erythrocytes. In this study we demonstrate that Ad5 particles, as mostly employed for gene therapy, have a strong affinity to human erythrocytes. At 60 min after coincubation of human erythrocytes and Ad5 particles, more than 98% of the particles are attached to the surface of erythrocytes. Therefore, ignoring the amount of red cell bound particles by performing titration in plasma leads to severe miscalculation of organ-specific transfer rates or virus circulation half-life. The biological impact of an increased affinity between virus particles and erythrocytes will be discussed.

Adenoviridae↗
PubMed2003

[Accuracy of the sonographic determination of the splenic weight in comparison with the weight at autopsy].

PURPOSE: The weight of the spleen can be easily calculated from sonographic measurements. This study investigates the correlations between the weight of the spleen determined sonographically and the weight measured at autopsy or after splenectomy. MATERIALS AND METHODS: The splenic weight at autopsy or after splenectomy was correlated with the calculated sonographic splenic weight in 55 patients who had a sonographic examination within the preceding three weeks. RESULTS: A significant correlation (r = 0.978) was found between the sonographically calculated splenic weight (460.82 grams) and the measured weight of the removed spleen (average weight 463.18 grams). Spleens weighing more than 1 kg showed a slightly weaker correlation. CONCLUSION: This study proves that the simple formula of length x transverse diameter x vertical diameter x 0.6 provides a reliable calculation of the weight of the spleen.

Autopsy↗
PubMed2003

[Morphology of gastrointestinal stromal tumors in advanced stages of the disease: baseline findings before chemotherapy with imatinib].

PURPOSE: Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract with an increasing detection rate due to improved differentiating methods in current diagnostic pathology. This study evaluates the radiologic characteristics of these neoplasms to discover specific signs leading to an earlier diagnosis. MATERIALS AND METHODS: As part of a randomized phase III clinical trial of the European Organization for Research and Treatment of Cancer (EORTC), 72 patients with advanced stage GIST were treated with the selective tyrosine-kinase-inhibitor imatinib (Glivec, Novartis, Switzerland). For initial staging, 60 patients underwent MRI and 12 patients underwent CT. RESULTS: GISTs are mesenchymal tumors that grow submucosally and exophytically and become multiple, nodular or ovoid in the advanced stage. The predominant findings are peripheral solid structures with strong contrast enhancement and a central necrosis. Metastases are primarily located in the liver, where they appear as oval or round, sharply delineated solitary lesions with central necrosis. CT demonstrates the primary tumors and local recurrences as nearly isodense with the liver. On MRI, the lesions are hypointense on T 1 -weighted sequences and hyperintense on T 2 -weighted sequences, compared to the liver. CONCLUSION: Immunopathology now enables the exact histologic separation of GISTs from other mesenchymal tumors. The radiological morphology is not sufficiently specific to differentiate GISTs from other mesenchymal tumors. In view of new therapeutic options, cognizance of their typical manifestations is of increasing importance for radiologists.

Adult↗