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M Reuter

Publications and source records attributed to M Reuter.

At least 109 records · Page 6Linked to original sources
PubMed1998

Critical evaluation of the specificity of MRI and TVUS for differentiation of malignant from benign adnexal lesions.

The aim of our work was to study the specificity of MRI in comparison with transvaginal US for differentiation of malignant from benign adnexal lesions. A total of 67 patients with clinically suspicious adnexal lesions were evaluated by MRI. Transaxial and coronal images were acquired using T1-weighted sequences before and following IV contrast and T2-weighted sequences. In all patients transvaginal ultrasound examinations (TVUS) were performed. For both imaging modalities each lesion was classified separately as either benign or malignant according to previously published criteria. Pathologic findings were available in 65 cases. Both MRI and TVUS correctly classified the 12 malignant lesions (sensitivity 100 %). Specificity (MRI: 78.2 %, TVUS: 65.5 %) and accuracy (MRI: 82 %, TVUS: 71.6 %) were higher with MRI than with TVUS, but differences were statistically not significant (p = 0.18 and p = 0.20, chi-square test). There was agreement/disagreement between findings of MRI and US in 52/15 lesions. The macroscopic criteria for malignancy are unspecific and result in a limitation of the specificity of both MRI and TVUS. The MRI technique is a valuable adjunct to TVUS by enabling further clarification of adnexal tumors with equivocal complex or solid vaginal sonographic findings.

Adnexal Diseases↗
PubMed1998

An endocrine brain? The pattern of FMRF-amide immunoreactivity in Acoela (Plathelminthes).

In order to solve the problem of whether the Acoela have a brain of a common flatworm type, an immunocytochemical study was performed of the pattern of FMRF-amide in the nervous system of four species of Acoela, Anaperus biaculeatus, Childia groenlandica, Antinoposthia beklemischevi and Mecynostomum sp. In all species a FMRF-amide positive bilobed brain-like structure lacking neuropile was observed. This brain is composed of large multipolar nerve cells with short processes. The FMRF-amide immunoreactivity appears as spots in the cytoplasm. Short lateral branches originating from the periphery of the brain were observed in Anaperus biaculeatus. No immunoreactive nerve cords were detected. The results indicate that the brain-like structure of Acoela is not homologous with the brains of other Plathelminthes and implies an independent evolution of Acoela.

Animals↗
PubMed1998

The NADPH-diaphorase staining reaction in relation to the aminergic and peptidergic nervous system and the musculature of adult Diphyllobothrium dentriticum.

A new category of signalling molecules--transmitter gases--has appeared. Nitric oxide (NO) is generated by nitric oxide synthase (NOS) and diffuses as a short-lived transcellular messenger through the plasma membrane. NADPH-diaphorase (NADPH-d) is a marker enzyme for NO-producing neurons. In this study the pattern of NADPH-d stained neurons in Diphyllobothrium dendriticum is described and compared to the pattern of aminergic and peptidergic neuronal elements and to that of the musculature stained with TRITC-labelled phalloidin. NADPH-d staining was observed in neurons in the bilobed brain and along the 2 main nerve cords and in nerve fibres close to the body musculature and the musculature of the reproductive ducts, the walls of the testicular follicles and in sensory endings in the tegument. The NADPH-d staining reaction and the 5-HT or FMRFamide immunoreactivities occur in separate sets of neurons.

Animals↗
PubMed1998

Atopy, airway reactivity and compressed air diving in males.

A decline in expiratory flow rates in divers has recently been attributed to chronic exposure to hyberbaric air. Airway hyperresponsiveness (AHR) to stimuli due to a hyperbaric environment may play a certain role in this context. The aim of this study was to determine the prevalence of AHR in compressed air divers and to assess the value of bronchial challenges for prediction of fitness to dive. A cross-sectional sample of 59 healthy male volunteers--28 divers and 31 diving candidates (controls)--who had been found fit to dive in a diving medical examination underwent additional allergy screening (skin prick and serum IgE) and a histamine bronchial challenge. Pre- and postchallenge body plethysmography was completed to assess AHR. AHR to histamine was significantly increased among divers and positively related to diving experience whereas divers and controls did not differ significantly with respect to age, anthropometric data, current smoking habits, skin prick reaction, and elevated serum IgE. Our results indicate an increased prevalence of AHR to nonspecific inhalation stimuli in experienced divers. Bronchial challenge tests may be helpful to detect asthmatics in the medical assessment of fitness to dive and for follow-up examinations during a diver's career.

Adult↗
PubMed1998

Expiratory flow limitation in compressed air divers and oxygen divers.

Divers are exposed to dense gases under hyperbaric and hyperoxic conditions and, therefore, may be at risk of developing respiratory disease. Long-term effects on respiratory function have been found in commercial divers who perform deep dives. This study was conducted to detect possible lung function changes in scuba divers who dive in shallow water using compressed air or oxygen as a breathing gas. A cross-sectional sample of 180 healthy male divers (152 air divers and 28 oxygen divers) and 34 healthy male controls underwent a diving medical examination including body plethysmography, diffusion capacity measurement and a cold-air isocapnic hyperventilation test (CAIH). Air divers and oxygen divers had a lower mid-expiratory flow at 25% of vital capacity (MEF25) than controls (p<0.01 and p<0.05, respectively). Oxygen divers also had a decreased mid-expiratory flow at 50% of vital capacity (MEF50) (p<0.05). Divers' groups and controls did not differ with respect to age, smoking or medical history. The prevalence of airway hyperresponsiveness to CAIH was 1.4% (n=3 divers). MEF25 and MEF50 were inversely related to years of diving (p<0.01 and p<0.001, respectively). The pattern of lung function changes obtained in scuba divers is consistent with small airways dysfunction and the association between diving exposure and lung function changes may indicate long-term effects on respiratory function.

Adult↗
PubMed1998

A new hot spot for mutations in the ret protooncogene causing familial medullary thyroid carcinoma and multiple endocrine neoplasia type 2A.

One hundred and eighty-one families with multiple endocrine neoplasia type 2A (MEN-2A) or familial medullary thyroid carcinoma (FMTC) have been investigated for mutations in the ret protooncogene in Germany. In 8 families with FMTC or MEN-2A, no mutation could be detected in the cysteine-rich domain encoded in exons 10 and 11 of the ret protooncogene. DNA sequencing of additional exons (no. 13-15) revealed rare noncysteine mutations in 3 families (codons 631, 768, and 844). In contrast to these rare events, heterozygous missense mutations in exon 13, codons 790 and 791, were found in 5 families (4 with MTC only; 1 family with MTC and pheochromocytoma) and 11 patients with apparently sporadic tumors. Two different mutations in codon 790 (TTG-->TTT, TTG-->TTC; Leu790Phe) and one mutation in codon 791 (TAT-->TTT; Tyr791Phe) created a phenylalanine residue. We conclude that codons 790 and 791 of the ret protooncogene represent a new hot spot for FMTC/MEN-2A causing mutations. With the discovery of these considerably common mutations in codons 790 and 791 and the identification of some rare mutations, 100% of the German FMTC/MEN-2A families could be characterized by a mutation in the ret protooncogene.

Adult↗
PubMed1998

Pulmonary Wegener's granulomatosis: correlation between high-resolution CT findings and clinical scoring of disease activity.

STUDY OBJECTIVE: To evaluate the usefulness of high-resolution CT (HRCT) for monitoring pulmonary disease activity in Wegener's granulomatosis (WG). DESIGN: Prospective study of CT and clinical data. SETTING: Main referral hospital for rheumatic diseases and department of diagnostic radiology of collaborating university hospital. PATIENTS: Seventy-three patients with WG underwent 98 staging examinations using HRCT. The status of pulmonary disease activity at the time of examination was scored according to clinical, bronchoscopic, BAL, and radiographic findings as follows: activity (n=25, group 1), past activity (n=45, group 2) and lack of any pulmonary disease (n=28, group 3). HRCT findings were correlated with the clinical scoring of pulmonary disease activity. RESULTS: Of 98 staging examinations 78 (79.6%) revealed abnormal CT scans showing the following main abnormalities: (a) nodules or masses (group 1: 16 [60.4%], group 2: 9 [20%]); (b) parenchymal bands (group 1: 12 [48%], group 2: 27 [60%], group 3: 6 [21.5%]); (c) septal thickening (group 1: 8 [32%], group 2: 6 [13.3%]); (d) parenchymal opacification (group 1: 7 [28%], group 2: 4 [8.9%]); and (e) pleural irregularity (group 1: 14 [56%], group 2: 22 [49%], group 3: 9 [32%]). Nodules/masses and areas of parenchymal opacification were significantly associated with florid disease activity of the lungs. Parenchymal bands and septal thickening were observed in both groups with pulmonary involvement, but statistical analysis revealed no significant difference. Pleural irregularities were nonspecific. CONCLUSION: HRCT may be a useful adjunct to clinical scoring of pulmonary disease activity in patients with WG and suspected lung involvement.

Adult↗
PubMed1998

[Transfusion of plasma of endotoxin tolerant rats improves survival of hemorrhagic shock in the rat model].

To evaluate the protective effect of endotoxin tolerant plasma after hemorrhagic shock, plasma of endotoxin tolerant animals was used for resuscitation of normal rats. The transfusion of plasma of endotoxin tolerant rats improved the survival rate from 20 to 60 per cent. In the sera of endotoxin tolerant animals a TNF inhibitory activity was detected, which could be transferred by the plasma. This effect may be responsible for the protection to hemorrhagic shock.

Animals↗
PubMed1998

[Endotoxin tolerance and hemorrhagic shock in rats].

The aim of the presents study was to investigate the protective capacity of endotoxin tolerance in a hemorrhagic shock model in rats. A pretreatment with low dose endotoxin induces a state of tolerance, which is characterized by decreased TNF alpha production in vivo and in vitro upon subsequent high dose endotoxin challenge. This endotoxin tolerance improves survival after hemorrhagic shock from 22.8% in untreated controls to 68.8 in tolerant rats. The protection was accompanied with the appearance of n TNF alpha inhibitory activity in the serum of endotoxin tolerant animals, which might be responsible for the improved survival after hemorrhagic shock.

Animals↗
PubMed1997

[Lymphomatoid granulomatosis--remission induction with interferon-alpha 2b].

HISTORY AND ADMISSION FINDINGS: A 72-year-old woman was admitted to hospital because of nonproductive cough, acrodistal sensorimotor axonal polyneuropathy, fatigue and 10 kg weight loss over the preceding 9 months. INVESTIGATIONS: Chest radiogram showed multiple round foci in both lungs. No organs other than the lungs and the peripheral nervous system were affected. Open lung biopsy revealed a pleomorphic angioinvasive lymphocytic infiltrations. DIAGNOSIS, TREATMENT AND COURSE: The findings indicated lymphomatoid granulomatosis (LG). Wegener granulomatosis was excluded on the basis of the clinical, serological and histopathological findings. Treatment with alpha-interferon (IFN-alpha) produced complete remission within 4 months. Interruption of treatment immediately resulted in a recurrence. CONCLUSION: Together with previously reported cases this patient's response to IFN-alpha suggests that IFN-alpha is a less toxic alternative to cyclophosphamide and corticosteroid administration in the early stages of LG.

Aged↗
PubMed1997

[MR angiography of pelvic arteries].

During the last years, magnetic resonance angiography (MRA) has become a widely used modality for intracerebral and carotid artery imaging. Due to technical limitations, the clinical impact of MRA in the iliofemoral arteries has been rather poor. New developments in MRA like ECG-triggered sequences and the occurrence of contrast-enhanced MRA has overcome most of these limitations. Therefore, a major advance in clinical use of these diagnostic tools can be predicted. This paper discussed the advantages of ECG-gated 2D-Phase contrast, ECG-gated 2D-Time-of-Flight and contrast enhanced FLASH 3D angiography sequences from a clinical point of view. 2D-PC-MRA is a robust technique, which provides an overview of the iliofemoral artery system in less than 5 minutes. Limitations are the true 2D impression of the sequence and the partial venous overlay. 2D-TOF-MRA on the other hand is time consuming, however it enables 3D reconstruction and effective venous suppression can be applied. Contrast enhanced MRA as the third sequence discussed provides high resolution images in less than 30 sec. However contrast bolus timing might be a problem. In conclusion the authors suggest a combination of 2D-PC-MRA and additional 2D-TOF sequences at questionable vascular areas as the modality of choice, due to the fact, that MRA of the iliofemoral arteries ist mostly only one step of a complete lower limb examination. Contrast MRA might become the method of choice in the future however problems with multiple contrast injections and upper limits of contrast dose have to be solved.

Adult↗
PubMed1997

Clinical and laboratory evaluation of a new thin-walled self-expanding tracheobronchial silicone stent: progress and pitfalls.

BACKGROUND: Although widely established in the management of malignant airway lesions, currently available tracheobronchial prostheses made of silicone have their drawbacks resulting from rigidity and wall thickness. Therefore we present clinical follow-up data obtained with a novel thin-walled expandable prototype silicone airway stent (Polyflex stent, Willy Rüsch AG, Kernen, Germany) in 19 patients. METHODS: Seventeen of 19 patients had tracheobronchial complications of infiltrating cancer: five had respiratory-digestive fistulas, 14 had mixed-type obstructions (mucosal infiltration plus extrinsic compression), and two had diffuse tracheal hemorrhages from the tumor surface (three patients had more than one complication). Two of 19 patients had benign postintubation stricture and malacia. Overall, 33 stents were implanted either simultaneously or in a consecutive manner. Scanning electron microscopy was performed both on prototype stents and on other available silicone stents for comparison. RESULTS: The treatment improved the patients' clinical condition substantially. The mechanical properties of the new prosthesis were excellent. Important stent-associated side effects were early mucus retention (n = 7), infolding of the inner silicone layer (n = 2), and stent dislodgment (n = 2). As of February 1997, 10 patients have died of causes unrelated to stent placement. Seven patients with malignant airway disease are still alive from 2 weeks up to 7 months after initial treatment. Scanning electron microscopy of explanted and unused prototypes suggested that an extremely ragged luminal microstructure may contribute to the firm adhesion of secretory material and that technical smoothing of the surface avoids such complications. CONCLUSIONS: The novel self-expandable silicone airway stent may be a promising addition to commonly used stent types. Short-term and medium-term management of fistulas, tumor surface bleeding, and strictures (malignant and benign) is satisfactory. Scanning electron microscopy of stents provides information on peculiar features of microstructure and material that may be of use in clinical research and technical innovation.

Adult↗
PubMed1997

[Digital chest x-rays with a selenium detector: a prospective comparison with a conventional film-screen combination].

PURPOSE: To compare a new digital chest radiography system that uses amorphous selenium as the x-ray detector, with conventional radiography for the detection of pathological alterations of the chest. MATERIAL AND METHODS: Two observers analysed pairs of posteroanterior and lateral chest radiographs of 95 patients. One pair of radiographs was obtained with the digital selenium chest radiography system, and the other with conventional film-screen technique. 9 criteria were rated using a 4 point scale. Technical parameters were standardised. Radiation dose was measured in both techniques and compared. RESULTS: A total of 855 criteria were rated. 740 findings were diagnosed in accordance on both techniques (740/855 = 87%). 115 criteria (115/855 = 13%) showed deviations. The mean radiation dose for the selenium detector was 0.02 cGy and for the conventional system 0.11 cGy. CONCLUSION: The exposure of radiation is lower using a selenium x-ray detector compared to conventional film-screen technique in chest radiography. The digital selenium system performs well in a clinical setting, providing visualisation of pathological findings as good as a standard screen-film system.

Adult↗
PubMed1997

MR imaging of the central nervous system in diving-related decompression illness.

PURPOSE: This investigation was conducted to determine whether MR imaging showed cerebral or spinal damage in acute diving-related decompression illness, a term that includes decompression sickness (DCS) and arterial gas embolism (AGE). MATERIAL AND METHODS: A total of 16 divers with dysbaric injuries were examined after the initiation of therapeutic recompression. Their injuries comprised: neurological DCS II n = 8; AGE n = 7; combined cerebral-AGE/spinal-DCS n = 1. T1- and T2-weighted images of the brain were obtained in 2 planes. In addition, the spinal cord was imaged in 7 subjects. The imaging findings were correlated with the neurological symptoms. RESULTS: MR images of the head showed ischemic cerebrovascular lesions in 6/8 patients with AGE but showed focal hyperintensities in only 2/8 divers with DCS. Spinal cord involvement was detected in 1/7 examinations, which was the combined cerebral-AGE/spinal-DCS case. There was agreement between the locations of the documented lesions and the clinical manifestations. CONCLUSION: MR readily detects cerebral damage in AGE but yields low sensitivity in DCS. A negative MR investigation cannot rule out AGE or DCS. However, MR is useful in the examination of patients with decompression illness.

Adult↗
PubMed1997

Efficacy of transbronchial biopsy in pulmonary vaculitides.

This study was performed to determine the value of transbronchial biopsy (TBB) in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides and mild-to-moderate pulmonary involvement. Included in the study were 19 patients with Wegener's granulomatosis (WG) and six patients with Churg-Strauss syndrome (CSS) with evidence of active pulmonary disease but without gross parenchymal lesions accessible by radiologically guided biopsy. All of the patients had undergone staging examinations which included TBB taken from peripheral lung tissue and from any focal tracheobronchial lesions. Any suspicious lesion in the upper respiratory tract was biopsied by an otolaryngologist and the number of positive biopsies was compared with that of TBB. In the WG patients, only two out of 17 biopsies of alveolar tissue yielded histopathological findings supporting the diagnosis of WG. In five WG patients, ulcerative or exophytic airway lesions were found whose histopathologies were invariably positive. Otolaryngological examination revealed abnormal findings in 19 WG patients and biopsies from these sites yielded positive results in 13 instances. In CSS, TBB produced a diagnostically helpful histopathology in four of six cases and biopsies from the upper respiratory tract were positive in five out of six cases. We conclude that transbronchial biopsies of alveolar tissue are seldom positive in Wegener's granulomatosis patients with mild-to-moderate pulmonary disease unless they are taken from grossly abnormal lung areas. Conversely, ulcerative, exophytic or stenotic tracheobronchial lesions had a high rate of positive findings. These results further suggest that the upper rather than the lower respiratory tract should be the biopsy site of first choice in Wegener's granulomatosis. In Churg-Strauss syndrome, the upper and lower respiratory tract seem to yield a roughly equal number of positive biopsies.

Adult↗