PubMed Health⌕ Search

Biomedical subjects

B Sander

Publications and source records attributed to B Sander.

At least 55 records · Page 3Linked to original sources
PubMed1997

Uveal melanoma: detection of extraocular growth with MR imaging and US.

PURPOSE: To compare the sensitivity and specificity of magnetic resonance (MR) imaging with that of ultrasound (US) in the detection of extraocular extension of uveal melanoma. MATERIALS AND METHODS: In 70 patients, the diagnosis of melanoma and absence or presence of extraocular growth were confirmed with histologic examination (13 patients) or with ophthalmoscopy and surgery (57 patients). Unenhanced and enhanced T1-weighted and T2-weighted MR imaging was performed with surface coils at 1.5 T. A- and B-mode US scans were obtained with 8- and 10-MHz probes, respectively. RESULTS: Extraocular growth was confirmed in seven patients: Five patients had retrobulbar tumor, and two had optic nerve infiltration. US enabled detection in three cases, whereas six cases were diagnosed with MR imaging including both cases of optic nerve infiltration. False-positive findings were more frequent with US (n = 5) than with MR imaging (n = 1). CONCLUSION: MR imaging proved to be more sensitive and more specific than US in the detection of extraocular extension of uveal melanoma.

Eye Neoplasms↗
PubMed1997

MR of the eye with retrobulbar anesthesia.

MR imaging with retrobulbar anesthesia was performed in eight patients with uveal melanoma. Injection of 2 mL prilocain hydrochloride in 2% epinephrin into the eye muscle cone resulted in improved image quality in seven patients, without side effects. Ocular MR imaging can be indicated to clarify indeterminate sonographic findings in cases of extrascleral growth or to exclude optic nerve invasion in patients with tumors located at the posterior pole of the globe.

Anesthesia, Local↗
PubMed1997

[Nuclear magnetic resonance tomography detection of heroin-associated CNS lesions].

Rare patterns of heroin-associated lesions within the central nervous system are described. In one case, magnetic resonance imaging revealed the combination of a border zone infarct within the thoracal spinal cord and a bilateral lesion within the globus pallidus. In a second case, cerebral border zone infarctions were observed which were attributed to a vasospasm of the basal cerebral arteries. Drug-abuse should be considered as a potential cause of these unusual manifestations of ischemic lesions in young patients.

Adult↗
PubMed1996

Clinical experiences with magnetic drug targeting: a phase I study with 4'-epidoxorubicin in 14 patients with advanced solid tumors.

Anticancer drugs reversibly bound to magnetic fluids (ferrofluids) could be concentrated in locally advanced tumors by magnetic fields that are arranged at the tumor surface outside of the organism. If certain requirements are met, systemic toxicity might be minimized, and local tumor efficacy might be increased. We have conducted a Phase I clinical trial using this approach in patients with advanced and unsuccessfully pretreated cancers or sarcomas. Nine such patients received two treatment courses, 3 patients received one course, and 2 patients received three courses of magnetic drug targeting consisting of the infusion of epirubicin in increasing doses (from 5 to 100 mg/m2) that had been chemically bound to a magnetic fluid and the application of magnetic fields to the tumors for 60-120 min. In 2 of 14 patients, the same dose of epirubicin not bound to a magnetic fluid was administered systemically 3 weeks after drug targeting for intraindividual comparisons. Magnetic drug targeting with epirubicin was well tolerated. In one case, a planned second treatment was withdrawn, because of an episode of chills 130 min after infusion of the magnetic drug. Two patients received a third treatment because of good responses after the first two therapies. Based on magnetic resonance tomographic techniques, pharmacokinetics, and the histological detection of magnetites, it was shown that the ferrofluid could be successfully directed to the tumors in about one-half of the patients. Organ toxicity did not increase with the treatment, but epirubicin-associated toxicity appeared at doses greater than 50 mg/m2. Although treatment with magnetic drug targeting seems safe, improvements are necessary to make it more effective and independent of patient- or disease-related problems. A study design to compare conventional treatments with the new treatment form within one patient seems crucial to eliminate interindividual differences.

Adolescent↗
PubMed1996

Tumor necrosis factor-alpha expression in human primary malignant malanoma and it relationship to tumor infiltration by CD3+ cells.

Optimal conditions for immunohistochemical staining of tumor necrosis factor-alpha (TNF-alpha) in paraffin-embedded tissue sections were established to investigate TNF-alpha expression in human primary malignant melanomas. Seventeen malignant melanomas of the nodular (NMM) and superficially spreading (SSM) subtypes were analyzed. Twelve of these were TNF-alpha+, while 5 did not stain for the cytokine. To evaluate how TNF-alpha expression affected the immune response to the tumors, infiltration by CD3+ and mac387+ cells was investigated in NMM. TNF-alpha expression seemed to selectively affect the capability of T cells to infiltrate the tumors since TNF-alpha+ tumors were found to have significantly lower levels of infiltrating CD3+ cells, while there was no difference in numbers of mac387+ cells. These results demonstrate that TNF-alpha is variably expressed in primary malignant melanoma in vivo and that the T-cell response to TNF-alpha-expression NMM is inhibited.

Adult↗
PubMed1996

Epidural lipomatosis: case report and literature review.

We report a case of symptomatic epidural lipomatosis in a 36-year-old man following a heart lung transplant and 3.5 years of steroid medication. A review of the pertinent literature emphasises the importance of including this diagnosis in the differential diagnosis of patients receiving steroid medication or markedly obese patients with back pain or symptoms suggesting spinal cord or cauda equina compression.

Adult↗
PubMed1996

Severe transitory encephalopathy with reversible lesions of the claustrum.

Reversible bilateral lesions of the claustrum and external capsule in a 12-year-old girl suffering from a severe, transitory encephalopathy are reported. After a prodromal stage of feeling uncomfortable a sudden onset of status epilepticus occurred, followed by recurrent complex partial and myoclonic seizures for 3 weeks, with psychotic symptoms and temporary loss of vision, speech and hearing. After treatment with phenytoin the patient became free of seizures and recovered completely without neurological deficit. The initial cranial CT was normal; however, cranial MRI 7 days later showed bilateral selective lesions of the claustrum and external capsule, which disappeared completely 5 weeks later. The aetiology of these lesions remains obscure; repeated cerebrospinal fluid and blood tests were negative for herpes simplex virus and other infectious agents. The clinical and radiological improvement were concomitant. This may indicate a functional disturbance of the claustrum grey matter, rather than lesions of the white matter of the external and extreme capsules.

Aphasia↗
PubMed1996

Applications of specialized coils for high-resolution MRI on a whole-body scanner.

To investigate the application of a mini-coil surface system for high-resolution MRI, 60 volunteers were examined in a 1.5-T whole-body scanner. Two replaceable probe heads were available: a circular 2.5-cm coil and a quadratic 5-cm coil, both of which were placed directly on the skin. The skin layers, Achilles tendon and finger joints were examined with the 2.5-cm coil and a FOV of 25 X 25 mm2. A matrix of 256 pixels resulted in a pixel size of 0.098 X 0.098 mm2. For imaging of the carpal tunnel, the 5-cm coil was used in transverse orientation. The FOV was 50 X 50 mm2 so that a matrix of 256 X 256 pixels led to a pixel size of 0.195 X 0.195 mm2. The resulting spatial resolution permitted visualization of the epidermis, dermis and subcutis, resulting in clear definition of anatomical detail of the musculoskeletal system. MRI measurement of skin-layer thickness did not correlate with histometric data (p < 0.05). This discrepancy was due in part to shrinkage of the tumor specimen on histologic preparation. Other causes include the motion artifacts and the limited accuracy of determining thickness on the MRI display unit.

Achilles Tendon↗
PubMed1996

[MRT of the eye: the normal anatomy and detection of the smallest lesions with a high-resolution surface coil].

PURPOSE: A new, high-resolution surface coil for MRI of the eye was evaluated with regard to practicability, image quality and sensitivity for small lesions. MATERIAL AND METHODS: 48 patients in whom a space-occupying lesion of the eye or orbit was suspected were examined (1.5 T tomograph, 5 cm surface coil, T1- and T2-weighted spin-echo sequences, the former before and after i.v. gadolinium DTPA). RESULTS: 45/48 patients tolerated MR with the high-resolution surface coil. No adverse effects were experienced by the patients. In 11/48 patients a space occupying lesion of the eye was detected (melanoma, 5; metastases, 2; haemorrhage, 1; malformation, hamartoma and scarring after melanoma, one each). The smallest detectable lesion had a thickness of < 1 mm. CONCLUSION: First experiences with the high-resolution surface coil indicate that this device is suited for detection of very small lesions of the eye.

Adolescent↗
PubMed1996

[Magnetic resonance tomography in patients with Parkinson's disease and Parkinson-plus syndromes].

PURPOSE: To define characteristic MR-findings in patients with clinically typical extrapyramidal movement disorders. METHODS: 15 patients with Parkinson's disease (PD), 9 with multisystem atrophy (MSA), and 6 with progressive supranuclear palsy (PSP) underwent MRI using a 1.5 T. Magnetom unit. Two investigators analysed the images with special regard to global and/or focal atrophy and to changes in signal intensity of the CNS in the consensus mode. Normal images of 10 subjects served as controls to patient's images. RESULTS: In all patients with PSP and MSA characteristic pathological findings on MRI were observed including regional changes within the extrapyramidal nuclei. In contrast all patients with PD had an unremarkable MRI study of the CNS. CONCLUSION: MRI enables us to define characteristic morphological changes of the brain in patients with extrapyramidal movement disorders. Early recognition of these findings avoids misdiagnoses in patients who are difficult to diagnose.

Adult↗
PubMed1996

Localization of IL-1, IL-2, IL-4, IL-8 and TNF in superficial bladder tumors treated with intravesical bacillus Calmette-Guerin.

PURPOSE: Cytokines have been detected in the urine during the first hours after intravesical Bacillus Calmette Guerin (BCG) treatment against superficial bladder cancer. To investigate the long-lasting mucosal inflammatory response, we analyzed intracellular cytokines by immunohistochemistry in biopsies taken 2 weeks after BCG treatment. MATERIALS AND METHODS: Tumor biopsies were obtained from 8 patients with noninvasive, papillary transitional cell carcinoma (TCC), and intracellular cytokines were visualized by immunohistochemistry using cytokine-specific monoclonal antibodies. RESULTS: Interleukin (IL)-1 beta+ or tumor necrosis factor (TNF)-alpha+ cells were abundant in tumor and stroma. Interleukin-1 alpha, IL-2, IL-4, IL-8 and TNF-beta were variably expressed, while IL-10+ and interferon (IFN)-gamma+ cells were not detected. Among the few patients studied (5 responders and 3 nonresponders to BCG treatment) no single cytokine or cytokine profile was associated with clinical response to BCG therapy. CONCLUSION: We conclude that the in situ cytokine response after BCG treatment is highly complex, since cytokine profiles differed among the 8 patients investigated and between tumor and surrounding tumor-free mucosa. Further studies, investigating larger numbers of patients, is required to clarify whether cytokine profiles correlate with the clinical response to BCG.

Administration, Intravesical↗
PubMed1995

Blockade of nitric oxide synthase differentially influences background activity and electrical excitability in rat dorsal horn neurones.

A previous study has shown that inflammation of the gastrocnemius-soleus muscle in rats leads to an increase in excitability of dorsal horn neurones particularly in the spinal segment L3. Here, we have blocked the nitric oxide synthase (NOS) in L3 by spinal cord superfusion with NG-monomethyl-L-arginine (L-NMMA) to find out if this effect is due to a release of nitric oxide (NO). L-NMMA had no influence on the excitability of L3 neurones but caused a marked increase in background activity. The L-NMMA effect on background activity was also present in rats with intact muscle. The data show that the myositis-induced increase in spinal excitability is not mediated by NO. The background activity, however, appears to be strongly dependent on NO production.

Amino Acid Oxidoreductases↗
PubMed1995

[Quantification of signal modulation of hematopoietic bone marrow in gradient echo sequences. Results of phantom and proband studies with simultaneous determination of T2* relaxation times].

The signals from spongy bone on gradient echo sequences depend on the fat and water proton content as well as the differences in magnetic susceptibility at the border between the trabeculae and the bone marrow. From the signal intensities for different echo times, signal modulation was quantified by a special algorithm and at the same time the T2 relaxation time was calculated. Using a fat-water phantom, it was shown that the product of the initial fat and water signal intensity (modulation coefficient) is applicable to indicate the extent of signal modulation and thereby the chemical shift and, moreover, to indicate changes in the fat/water ratio sensitively. In 16 individuals of different ages (23 to 64 years, average 42.4 years) there was a tendency for the T2 relaxation time from the spongiosa of lumbar vertebrae to increase with age, this can be explained by a reduction in the trabecular content, causing reduction in the magnetic inhomogeneity of the bone marrow. The results indicate the usefulness of the sequence and the mathematical model for evaluating the spongy bone in cases of osteoporosis and of malignant haematological disorders.

Adult↗
PubMed1995

[Megadolichobasilar artery as a rare cause of hydrocephalus internus: synopsis of modern imaging methods].

Megadolichobasilarartery (MDB), i.e. the widened, elongated and tortuous course of the basilar artery, has been the topic of numerous publications; about 350 cases have been reported world-wide. It can cause many symptoms; isolated or combined cranial nerve lesions and ischemic or hemorrhagic changes are the most frequent. A hydrocephalus internus is a rare occurrence and many patients do not exhibit any symptoms. To date, angiography, computed tomography, and to an increasing extent magnetic resonance imaging (MRI) are the principal methods for diagnosis of MDB. Angiographic-like representations with CT and MRI are further developments which represent an alternative to angiography. With the help of special MRI sequences, furthermore, non-invasive CSF flow measurements for the etiologic evaluation of a hydrocephalus can be performed. For the example of a patient with MDB and hydrocephalus internus, the possibilities of modern imaging techniques are presented and discussed.

Basilar Artery↗
PubMed1995

Sequential production of Th1 and Th2 cytokines in response to live bacillus Calmette-Guérin.

Causes of individual variation in susceptibility to mycobacterial diseases are only partly understood. An efficient cell-mediated immune response is crucial for resistance. Macrophages and T cells interact to eliminate the mycobacteria, partially through the effects of secreted cytokines. A vigorous anti-bacterial inflammatory response is sometimes accompanied by severe tissue damage, while immunosuppression leads to progressive infection. Here, live, attenuated Mycobacterium bovis, bacillus Calmette-Guérin (BCG), was used as a model antigen to study cytokine production at the single-cell level in response to mycobacteria. Peripheral blood mononuclear cells from healthy individuals were challenged in vitro and the kinetics and frequencies of cytokine-producing cells were studied by immunofluorescent visualization of intracellular cytokines. Fourteen cytokines were assayed; interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist (IL-1ra), IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), TNF-beta and granulocyte-macrophage colony-stimulating factor (GM-CSF). A sequential production of T helper-1 (Th1) and T helper-2 (Th2) cytokines was induced by BCG. Early, at days 1-2 after stimulation, the response was dominated by monokines and a low IFN-gamma and TNF-beta production. At days 4-5 there was a marked production of Th1 lymphokines, with approximately 6% IFN-gamma+ cells, 4% TNF-beta+ cells and 2% IL-2+ cells. Late in the reaction, at days 10-12, a Th2 response with IL-4, IL-5 and IL-10 was detected, while the synthesis of Th1 lymphokines and monokines declined. Overall, our results provide further evidence of IFN-gamma as the major cytokine induced by mycobacteria in healthy individuals, but also suggest that Th2 cytokines participate in the response.

Adult↗
PubMed1995

Magnetic resonance perfusion imaging with gadolinium-DTPA. A quantitative approach for the kinetic analysis of first-pass residue curves.

RATIONALE AND OBJECTIVES: To present a mathematic approach for the analysis of first-pass gadolinium (Gd)-DTPA kinetics and to validate the numerical tools using simulated and measured kinetics. METHODS: In a capillary plasma filter, pulsatile flow was varied between 7.4 and 12.6 mL/second. After contrast bolus injection, the arterial input curve and the residue curve were recorded simultaneously. Signal intensity versus time curves were converted to concentration versus time curves. By deconvolution of these curves and tracer kinetic analysis, the mean transit time of the contrast medium through the organ model was calculated. RESULTS: A satisfactory correlation (r = 0.98) between the inverse of mean transit time and flow measured volumetrically was demonstrated. CONCLUSIONS: The kinetic analysis of first-pass curves in an organ model indicates that this approach might be useful for in vivo assessment of organ blood flow.

Blood Flow Velocity↗