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Biomedical subjects

M Beese

Publications and source records attributed to M Beese.

16 recordsLinked to original sources
PubMed2003

Combined use of confocal laser scanning microscopy and transmission electron microscopy for visualisation of identical cells processed by cryotechniques.

Successive visualisation of identical plant cells by light and electron microscopy is reported. For this purpose segments of pea and barley leaves were prepared by high-pressure freezing, freeze-substitution, and low-temperature embedding. The use of Safranin O during low-temperature dehydration allowed, on one hand, staining of all cellular components as investigated by confocal laser scanning microscopy and, on the other hand, excellent ultrastructural and antigenic preservation. A newly constructed specimen holder enabled precise relocation of the target cells for electron microscopic investigations. Transmission electron microscopy and immunohistochemistry revealed that during the whole procedure the ultrastructure of the cells as well as the antigenicity of cell constituents were preserved.

Cryoelectron Microscopy↗
PubMed1998

[Transmyocardial laser revascularization--the initial experiences of imaging in MRT].

PURPOSE: Imaging of myocardial signal alteration and perfusion differences after transmyocardial laser revascularization (TMLR). METHODS AND MATERIAL: 5 patients suffering from coronary vessel disease underwent MRI (0.5 T) pre- and 4-7 d post-TMLR. T1-weighted spin echo sequences were acquired ECG-triggered native and after injection of gadolinium. Qualitative analysis was performed on both native and contrast-enhanced images. Myocardial signal alterations and wall changes were evaluated. Qualitative and quantitative analyses of contrast-enhanced images were performed with regard of post-therapeutic perfusion differences. Analysis was based on contrast-to-noise (C/N) data obtained from operator defined "regions of interest". RESULTS: Visualization of laser-induced channels was not possible. Native scans obtained before and after TMLR revealed no significant change with regard to the qualitative analysis. Both qualitative and quantitative analyses demonstrated a posttherapeutic increase of C/N in both the left ventricular myocardium (64.4 pre-TMLR; 89.1 post-TMLR; p = 0.06) and the septum in the majority of cases. No significant difference between laser-treated left myocardium and untreated septum was observed (p > 0.05). DISCUSSION: Single myocardial laser channels could not be visualized with a 0.5-T MRI. However, visualization of increased myocardial contrast enhancement in laser-treated left ventricular myocardium was evident in the majority of cases on the basis of qualitative and quantitative analyses. CONCLUSIONS: The MRI technique used enabled a first, limited depiction of TMLR-induced myocardial changes. The clinical value and impact still have to be defined.

Aged↗
PubMed1998

[Computerized tomography and F-18-FDG positron emission tomography in staging of malignant lymphomas: a comparison].

PURPOSE: To determine the value of F-18-FDG-positron emission tomography (FDG-PET) compared with computed tomography (CT) in the staging of malignant lymphomas. MATERIAL AND METHOD: 50 patients with biopsy-proven lymphoma were studied with FDG-PET and CT. The results in initial, posttherapeutic and staging of recurrence were compared. RESULTS: 37 of 65 FDG-PET were identical with CT. 28 studies showed differences. 14 post-therapeutically and one of the initial studies led to downstaging by FDG-PET were as upstaging resulted in one case of initial staging. In two cases false positive pulmonary FDG accumulations caused an upstaging. CONCLUSION: FDG-PET was at least comparable to CT in recording the extension of a newly diagnosed lymphoma, or its recurrence. Upstaging according to FDG-PET occurred only once in initial staging. FDG-PET plays its most important role in the evaluation of residual mass in CT after therapy by accumulating FDG in viable tumour rather than in fibrotic tissue. 14 cases of downstaging according to FDG-PET resulted.

Adolescent↗
PubMed1998

[Chest X ray: routine indication in the follow-up of differentiated thyroid cancer?].

AIM: This retrospective study sought to elucidate whether routine chest x-ray is still useful for detection of pulmonary metastases in low risk patients despite the high sensitivity of the tumor marker thyroglobulin. METHOD: The hospital files of 609 patients with well-differentiated thyroid cancer were analysed. Pulmonary formation of metastases was diagnosed in 50 patients. The thyroglobulin value at the time of diagnosis was compared with the chest x-ray findings and, if present, additional diagnostic information such as Iodine-131 whole body scintigraphy (WBS) and thorax CT. RESULTS: The sensitivity of the chest x-ray to detect pulmonary metastases was at 52% lower than that of WBS (64%), thorax CT (82%) and thyroglobulin during suppression therapy (86%). Among the patients with papillary carcinoma stage I and II (UICC 1987), only 1 patient developed pulmonary metastases during follow up. In this low risk group of patients, detection of lung metastases exclusively by chest x-ray, without elevation of thyroglobulin level is extremely rare (calculated probability 1/4000) and associated with considerable costs. CONCLUSION: Routine, life long chest x-ray in low risk patients without a suspected recurrence (e.g. positive thyroglobulin) needs to be reconsidered.

Carcinoma, Papillary↗
PubMed1997

[Computerized tomography of retroperitoneal liposarcoma].

Besides the malignant fibrous histiocytoma, liposarcoma is one of the most common soft-tissue sarcomas seen in adults. They are most often localized in the lower extremity, followed by sarcomas in the retroperitoneal space which differ from the former in clinical appearance, epidemiology, and prognosis. The prognosis is especially dependent on tumor histology which is mainly classified into four subtypes. The aim of the study was to investigate whether there are specific CT-features for each histologic subgroup, by analyzing the examination of 20 patients. The highest percentage in fat and the biggest tumors were seen with well-differentiated liposarcomas (n = 4), whereas myxoid ones (n = 6) showed the sharpest margins. Round-cell (n = 2) and pleomorphic (n = 5) and pleomorphic (n = 5) types showed mainly soft-tissue attenuation and could not be differentiated, either from each other or from other soft-tissue tumors. A clear identification of the histologic subgroup does not seem to be possible.

Adult↗
PubMed1994

[MR tomography in prostatic carcinoma: comparison of conventional and endorectal MRT].

In a prospective study an attempt was made to determine the value of conventional MRI (354 patients) and MRI using the endorectal surface coil (ESC) (36 patients) in the preoperative staging of prostatic carcinoma. Local preoperative staging with conventional MRI was correct in 83.9% and 88.9% with ESC-MRI. Compared to conventional MRI, ESC-MRI was better in the delineation of the prostatic capsule and early detection of infiltration into the neurovascular bundle. Lymph node staging with MRI showed a sensitivity of 54.4% in detecting pelvic lymph node metastasis. MRI is as limited as CT in assessing pelvic lymph node metastasis.

Evaluation Studies as Topic↗
PubMed1994

[Dysbaric osteonecrosis in professional divers: MRT as a screening method?].

20 male professional divers underwent a total of 68 MR examinations of the shoulder, hip and knee joints with follow-up for 16 joint regions. Cerebral MR was performed additionally in 16 divers. 11 patients showed signal alterations of bone marrow which suggested bone infarct in 9 cases. One patient had unifocal demyelinisation of the left hemisphere. In conclusion, MR showed high sensitivity in detecting dysbaric osteonecrosis.

Adult↗
PubMed1993

[Indications for spiral-CT in the upper abdomen and the retroperitoneum].

Spiral CT allows the continuous scanning of different organ volumes. This series illustrates our experiences gained with spiral CT technique imaging of the upper abdomen and retroperitoneal space in about 150 patients. The scanning parameters were 120 kvp, 165 mA with a slice thickness of 8 mm and a table speed of 8 mm/s. The total scanning time was 32 s. If required, a non-ionic iodinated contrast medium was administered via a medial cubital vein or the upper mesenteric artery by performing an arterial portography. CT during arterial portography for preoperative detection and localization of focal liver lesions, staging of renal cell carcinoma, and imaging of pancreatic disease are at present the main indications for using the spiral CT technique. Furthermore, it is the method of choice for scanning uncooperative patients.

Humans↗
PubMed1992

[Transcatheter embolization of tumors of the muscular and skeletal systems].

The value of transcatheter embolisation of tumours of the musculoskeletal system is discussed on the basis of 26 cases. All procedures were performed following diagnostic angiography (DSA). By preoperative vascular occlusion it was possible to prevent major blood loss during surgery, provided the operation was carried out within three days of embolisation. Reduction in size of some large inoperable metastases before radio-iodine therapy is another indication for embolisation. As a palliative measure, vascular occlusion can be used for reducing otherwise untreatable skeletal pain and for the management of arteriovenous malformations. Bleeding from a tumour can be controlled by vascular occlusion. Our results indicate that transcatheter embolisation is an effective and reliable technique.

Adolescent↗
PubMed1991

[Computed tomographic and anatomical studies on the morphology of the minor pulmonary fissure].

The morphology of the minor fissure, i.e., the shape of the upper surface of the middle lobe, was studied in 10 specimens and in 60 thoracic CT's. In 8 specimens and 54 CT's there was the arrangement typical for the right lung consisting of 3 distinct lobes. The upper surface of the middle lobe had a convex upward shape against the base of the upper lobe in all anatomical preparations and in 52 of the CT's. The position and shape of the convexity was, however, quite variable. In 2 cases the upper surface of the middle lobe was flat. In 78% the minor fissure was incomplete and in 2 cases it was absent.

Adult↗
PubMed1990

[Pneumopericardium with combined emphysema of the skin and mediastinum following tooth extraction].

Emphysemas of the skin in the region of the cheek and face after surgical tooth extraction are relatively rare complications that can eventually lead to formation of an emphysema of the mediastinum and very rarely also to a pneumopericardium. The reason for this is often an instrumentally conditioned pressure increase in the oropharynx if this pressure increase leads to the entry of air into the wound region. There are also other mechanisms resulting in the formation of spontaneous mediastinal emphysema that can lead to a secondary emphysema. Possible reasons for the occurrence of a combined emphysema of the skin, the mediastinum and the pericardium are discussed.

Adult↗
PubMed1988

New bacteriophages active on strains of Hyphomicrobium.

Fifty-five lytic bacteriophages isolated from water and soil samples were active on many strains of the genus Hyphomicrobium. The optimal isolation procedure was an adsorption method in which samples from a habitat similar to that of the respective host bacterium were used as the phage inoculum. According to the morphology and nucleic acid type these bacteriophages belonged to different families: Myoviridae (type A1: five phages); Styloviridae (type B1: 33 phages; type B2: eight phages) and Podoviridae (type C1: nine phages). The Styloviridae (type B1) appeared in two morphological variants (tails flexible or rigid). All phages investigated were specific for the genus Hyphomicrobium and were unable to lyse members of other genera of hyphal, budding bacteria (e.g. Hyphomonas, Pedomicrobium, genus D, genus T). The host specificity of 42 phages was tested with 156 Hyphomicrobium strains: 122 strains were lysed by at least one of these phages, but 34 Hyphomicrobium strains were not susceptible. Morphotype B1 phages with identical morphology could be distinguished according to their host-range properties on prophage-containing Hyphomicrobium strains. With regard to differences in morphology and host range, 25 phages were selected for more detailed investigations. From these phages DNA was isolated; the melting transition midpoints (Tm) ranged from 67 to 93 degrees C. The upper and higher values suggested the presence of DNA modifications. Six different adsorption patterns could be distinguished among the Hyphomicrobium phages. Preferred attachment sites were the proximal pole of the mother cell, the hyphal tip, the distal pole of the bud, and the distal pole of the swarmer cell.

Bacteria↗
PubMed1988

[Acute pseudo-obstruction of the colon].

Acute pseudo-obstruction of the colon is a probably often misdiagnosed type of ileus, the diagnosis of which follows from the clinical pattern with the signs of a mechanical ileus, the acute course and the x-ray signs. Radiological findings cannot be clearly interpreted without knowledge of the clinical pattern and the course of the disease. Hence, the radiological correlate of the pseudo-obstruction of the colon is not specific, but it does supply a pointer to the disease of its shows dilation of the caecum, colon ascendens and colon transversum with air-pockets and reflected imaging as well as a usually not dilated colon descendens with remarkably little air. To make the diagnosis quite sure we must exclude intestinal obstruction by using x-ray contrast media or by coloscopy. Early diagnosis is important because of the danger of perforation of the massively dilated colon (lethality up to 60%) and good prognosis if therapy is initiated in time via compression by a Dennis sound (success rate 90%). To control the success of the treatment there must be a 24-hour x-ray follow-up to avoid the risk of perforation of the colon. In this manner it becomes possible to spare the usually elderly and multimorbid patients an operation at an enhanced risk.

Acute Disease↗
PubMedDate not supplied

[Azathioprine ingestion with suicidal intent by an adolescent with chronic juvenile polyarthritis].

We report on a 13 years 7 months old boy who ingested 650 mg azathioprine in a suicide attempt. His baseline medication was azathioprine and methotrexate for control of juvenile chronic polyarthritis. After the induction of vomiting by ipecacuanha sirup and administration of charcoal (1 g/kg), he was closely followed for haematological, hepatic, and renal side effects. During the following days, no serious adverse events were noted except that the thrombocyte (from 403,000 down to 199,000/microliter) and total leukocyte count decreased moderately (from 12,000 down to 7100/microliter). On the basis of this case report and the available literature, the potential acute toxicity of azathioprine and possible treatment modalities are discussed.

Adolescent↗