Biomedical subjects

M Heller

Publications and source records attributed to M Heller.

At least 217 records · Page 12Linked to original sources

PubMed1996

Mechanisms and factors involved in Mycoplasma bovis adhesion to host cells.

Mycoplasma (M.) bovis cytadhesion was studied using permanent embryonic bovine lung (EBL) cells as host system. Adherence rates were found to be strongly dependent on temperature and the mycoplasma-to-EBL ratio near the point of saturation of the attachment isotherm was determined to be 225 : 1. Mild trypsinization of viable M. bovis cells caused a measurable decrease of adherence indicating that surface proteins, among them the P26 antigen, played a major part as adhesion factors. Neuraminidase treatment of mycoplasmas led to a drastic reduction of adherence rates, which emphasizes the importance of sialyl moieties in adhesive interactions. The ability of the P26 antigen, a hydrophilic 32-kDa protein, to function as an adhesin was confirmed using a competitive adherence assay, in which the HPLC-purified protein was shown to reduce mycoplasma adhesion. These data complement previous findings obtained with the corresponding monoclonal antibody (MAb) 4F6. In further inhibition experiments, it could be demonstrated that MAb 1E5, which is directed against a common epitope of at least three members of the Vsp (variable surface protein) family of M. bovis, was also capable of decreasing mycoplasma attachment to EBL cells. This is the first evidence of possible involvement of Vsps in cytadhesion. In an effort to identify more putative adhesion proteins of this organism, the reverse adherence screening assay was used, a procedure based on the specific binding of labelled mammalian tissue culture cells to Western-blotted mycoplasmal proteins.

Adhesins, Bacterial↗

PubMed1996

[The CT of calcaneal fractures: 3-D reconstructions with electronic disarticulation].

PURPOSE: To evaluate the clinical value of 3-D-reformations with and without electronic disarticulation of calcaneal fractures compared to axial CT and sagittal reformations. MATERIAL AND METHODS: 25 patients with intra-articular calcaneal fractures underwent diagnostic CT-examinations. Axial slices, sagittal and 3-D-reformations with and without electronic disarticulation were performed. The sagittal and both types of 3-D-reformations were compared to the axial slices with regard to the diagnostic criteria: involvement of articular facets, number of fragments, and traumatic changes of the hindfoot. RESULTS: The best proof of involvement of articular facets is found in axial slices and 3-D-reconstructions after disarticulation followed by sagittal reconstructions. Usually on 3-D-reconstructions without disarticulation articular facets cannot be identified because of overlapping bones. The number of fragments is clearly demonstrated by axial slices and sagittal reconstructions followed by 3-D-reconstructions after disarticulation. Traumatic changes of the hindfoot can be diagnosed in all four forms of visualisation. CONCLUSION: The decisive diagnosis for treatment planning is made based on the axial slices supported by sagittal reformations. In unclarified cases 3-D-reformations after electronic disarticulation may provide further information. 3-D-reformations without disarticulation are useless.

Adult↗

PubMed1996

[MR angiography in fibromuscular dysplasia of the cervical arteries].

PURPOSE: To determine 3-D time of flight MR angiography for evaluation of fibromuscular dysplasia in cervical vessels. MATERIAL AND METHODS: In 386 selective angiograms of cervical vessels fibromuscular dysplasia was revealed in 4 female patients in the age of 30-54 years. FMD was located in the carotid artery (n = 5) and in the vertebral artery (n = 2) with a total of 8 lesions. RESULTS: 6/8 of the lesions of the seven cervical vessels were located typically in the mid cervical portion of the vessels and 2/6 lesions were located in the atlas loop of the vertebral artery. 4 lesions showed moderate stenosis and 4 vessels showed only mild stenosis. These patterns which demonstrated the typical morphology of fibromuscular dysplasia with alternating irregular zones of widening and narrowing were evaluated well with MR angiography, the others were missed. CONCLUSION: MR angiography is suitable for detection of fibromuscular dysplasia when the characteristic pattern is combined with moderate stenosis of the vessel. Conventional angiography remains the standard of reference.

Adult↗

PubMed1996

[Preoperative differential diagnosis of cystic adnexal tumors: double-contrast MRT].

PURPOSE: Preoperative assessment of adnexal lesions as benign or malignant by MRI with gastrointestinal and intravenous contrast. METHODS: 46 patients with benign (n = 42) and malignant (n = 4) cystic adnexal tumours underwent MRI of the pelvis. Transaxial and coronal images were acquired using conventional T1- and T2-weighted SE-sequences after oral administration of superparamagnetic iron oxide particles (Ferristene). Additional T1-weighted SE-images were obtained immediately following gadodiamide (Gd DTPA-BMA) injection. RESULTS: MRI correctly classified the four malignant lesions, whereas nine histologically benign lesions were misdiagnosed as malignant. Intravenous contrast yielded a superior delineation of intratumor architecture. CONCLUSION: Due to exclusion of solid structures. MRI with oral and i.v. contrast enables to dismiss suspected malignity in cystic adnexal lesions. Because of the non-specificity of the macroscopic criteria of dignity, the MR diagnosis "malignity" is of limited value.

Adenocarcinoma↗

PubMed1996

[Technical modification of the rheolytic thrombectomy].

A 48-year-old male patient with acute occlusion (5 cm) of a leg artery was treated with the rheolytic thrombectomy (RT). As recommended the catheter is applied via a single coaxial running guide wire, which is removed later. If an additional wire has been placed in the occluded vessel segment, the occlusion can be passed repeatedly. A 30 degrees bent catheter tip improves the removal of wall-adherent thrombotic material. The occluded segment was successfully recanalized with the RTC, 270 ml of heparinised saline had been injected. The blood examinations showed mild haemolysis.

Arterial Occlusive Diseases↗

PubMed1996

[Results of percutaneous implantation of coated vascular prostheses in long-distance femoropopliteal occlusions].

PURPOSE: Evaluation of primary patency rate, complications and midterm follow-up after implantation of endoprostheses in femoropopliteal occlusions. MATERIAL AND METHODS: 25 patients suffering from femoropopliteal occlusion (average length 7 cm) underwent percutaneous femoropopliteal endoprosthesis treatment. A total of 34 endoprostheses were implanted. Clinical and Doppler follow-up was performed after 1, 3, 6 and 9 months. Mean follow-up is 6 months. RESULTS: Percutaneous placement of endoprostheses was successful primarily in 24/25 patients. In one patient an early occlusion of the endoprosthesis occurred, caused by an embolic complication. Primary patency was 64% after 6 months and secondary patency rate was 71%. Severe local pain at the application site and fever was observed in 40% of the patients. CONCLUSION: The occlusion rate of 36% after 6 months is high. Long-term follow-up must be awaited before a general recommendation can be made. The cause of the local pain and fever in the early postinterventional period remains unclear.

Adult↗

PubMed1996

[Mechanical thrombolysis with the Amplatz thrombectomy catheter].

PURPOSE: To determine the efficiency of the Amplatz thrombectomy device (ATD) in thromboembolic occlusions of lower limb arteries and haemodialysis shunts. PATIENTS AND METHODS: 9 patients (mean age 61 years) with either occluded native leg arteries (n = 7) or haemodialysis graft access (n = 2) were treated with the ATD. Mean length of occlusion was 10 +/- 4.47 cm. RESULTS: The occlusions were primarily successfully recanalized by ATD within 44 +/- 17 seconds. Remaining stenoses were treated with percutaneous transluminal angioplasty (PTA, n = 6) and an additional implantation of a vascular stent (n = 3). The ankle-brachial-index (ABI) increased from 0.46 +/- 0.37 to 0.81 +/- 0.2 within 24 hours after intervention. In the first month ABI measured 0.9 +/- 0.15 and decreased from 0.7 +/- 0.23 after three months to 0.72 +/- 0.26 within 6 months. After 5 months, a shunt occlusion and a native leq artery occlusion appeared. CONCLUSIONS: Thrombolysis by ATD is a safe, feasible and simple procedure. There are no contraindications. No complications were seen.

Adult↗

PubMed1996

[MR diagnosis after a Ross operation].

PURPOSE: To determine the ability of MRI to diagnose morphological and functional changes in patients after Ross procedure. MATERIAL AND METHODS: During one year, 5 patients after Ross procedure were studied by MRI. T1-weighted spin-echo sequences in different orientations as well as cine sequences and a VENC sequence were used. RESULTS: In all patients the morphology including the postoperative changes could be visualised by MRI. The cine sequences provided functional information on valvular and ventricular function. VENC-MR yielded an exact quantification of the regurgitant fraction. CONCLUSION: MRI is capable of providing all important diagnostic information in patients after Ross procedure such as valvular and ventricular function and valvular and outflow tract morphology in a single examination.

Adolescent↗

PubMed1996

[MR angiography of the carotid arteries using 3D TOF technique with sagittal double-volume acquisition using a new head-neck coil].

PURPOSE: The aim of the study was to assess the value of MR angiography (MRA) in sagittal technique compared to DSA in the evaluation of carotid artery stenosis. METHODS: 80 carotid arteries in 40 symptomatic patients were prospectively studied with DSA and MRA. MRA was carried out by means of 3 D time-of-flight technique with a FISP sequence (TE6 ms/TR80 ms, flip angle 25 degrees, FOV 240 x 210 mm, matrix 157 x 256 mm, in-plane resolution 1.34 x 0.94 mm, partition thickness 1.32 mm, slab thickness 45 mm, acquisition time 7 min) using a new head-neck coll. Data acquisition was performed in sagittal orientation with the "double-slab" technique. Imaging quality of the extracranial carotid arteries and correctness of quantification of stenosis was performed. RESULTS: Imaging quality was good at the origin of the carotid arteries in 65%, at the bifurcation region in 98% and near the skull base in 81%. The agreement of DSA and MRA was 96% of the normal arteries (24/25), 90% of the severe stenoses (28/31) and 100% of the occluded arteries (9/9). CONCLUSION: MRA in sagittal "double-slab" technique is a noninvasive technique allowing to detect normal arteries and candidates for surgery with a high degree of certainty.

Adult↗

PubMed1996

[Modified manual rt-PA pulse-spray lysis in occlusions of leg arteries and femoro-popliteal bypasses].

PURPOSE: The evaluation of local rt-PA pulse-spray-lysis (PSL) by the Katzen infusion wire for treatment of thrombosed leg arteries and bypass grafts. MATERIAL AND METHOD: 21 patients (mean age 64.4 years) with either occluded leg arteries (n = 19) or femorocrural bypass grafts (n = 2) were treated with PSL. Mean length of occlusion was 13.2 +/- 11.6 cm. Time of occlusion ranged from less than one week to 6 months. RESULTS: In 71.43% (15/21) the occlusions could be successfully recanalized with PSL. The mean rt-PA dose was 10.7 +/- 4.9 mg. Remaining stenoses were handled with PTA (n = 9) and additional stent implantation (n = 3). Additional long-time-lysis with 17.5 mg rt-PA was necessary in two cases, the success rate increased to 81% (17/21). The anlde-brachial-index increased from 0.38 +/- 0.29 to 0.83 +/- 0.32 within 24 hours after intervention. In 4 cases bleeding complications occurred. 5 patients showed reocclusions during 6 months follow-up. CONCLUSIONS: Local fibrinolysis with rt-PA in PSL technique using the Katzen infusion wire is a feasible and promising treatment of thrombosed leg arteries and grafts. Even careful and dosage-minimized rt-PA application cannot prevent bleeding complications.

Adult↗

PubMed1996

Response to trimethoprim/sulfamethoxazole in Wegener's granulomatosis depends on the phase of disease.

We prospectively studied trimethoprim/sulfamethoxazole (T/S) in inducing remission in 'initial phase' Wegener's granulomatosis (WG), and in sustaining remission in generalized WG, in 72 patients in various disease stages. Nineteen patients with initial phase WG received T/S (2 x 960 mg/day). Another 24 patients with generalized WG received the same dose of T/S (group A) and were compared with 21 patients receiving no further treatment after standard therapy (group B). Eight patients were given T/S plus low-dose prednisone (group C). Eleven of 19 patients (58%) with initial phase WG achieved complete or partial remission lasting a median 43 months (range 6-88 months). Of the remaining eight (42%), five showed local disease progression, and three developed generalized WG. In group A (T/S alone, generalized WG), 10/24 (42%) suffered a relapse after a median 13 months (range 4-58 months). In group B (generalized WG, no further treatment) 29% of patients relapsed after a median 22.5 months (range 18-26 months). All eight patients treated with T/S plus low-dose prednisone (group C) suffered serious relapse after 2-24 months. T/S induced long-term remission in > 50% of patients with initial phase WG; however, neither T/S alone nor T/S plus low-dose prednisone sustained remission in generalized WG.

Adult↗

PubMed1996

Effect of intraarticular pressure on patellar position. Computed tomography study in cadaveric specimens.

RATIONALE AND OBJECTIVES: The purpose of the study was to evaluate the effect of articular fluid distention on patellar position at different degrees of knee angulation. METHODS: Patellar position in 10 cadaveric knee specimens was determined with 30, 100, and 200 mm Hg joint distention at 45, 20, and 5 degrees of knee flexion using computed tomography. Patellar tilting and lateromedial and anteroposterior displacement of the patellar position were analyzed. RESULTS: Lateral tilting increased with greater articular distention and decreasing knee flexion. At 5 degrees of flexion and 200 mm Hg of distention, change in lateral tilting ranged from -7 to +5 degrees. At 45 degrees of flexion and increased distention, the patellar shift ranged from 6 mm medialization to 1 mm lateralization for 200 mm Hg, but the patellar position was more variable at 5 degrees of flexion with increasing intraarticular pressure (range 7 mm medialization to 8 mm lateralization). With increasing articular pressure the patellae were increasingly displaced anteriorly with the most pressure-dependent changes at 45 and 20 degrees of knee flexion. CONCLUSIONS: Fluid distentions of the knee joint have unpredictable and varying effects on the patellar position and vary considerably among persons. When judging patellar position during arthroscopy and in patients with large joint effusions, the arthroscopist and radiologist should be aware of these effects.

Aged↗

PubMed1996

Eye patch treatment for the pain of corneal abrasion.

The traditional use of patching and topical antibiotics in the treatment of corneal abrasion has recently been challenged, particularly after foreign body removal. In a prospective, controlled, randomized study of 33 patients treated in the emergency department for eye pain and corneal abrasion, we attempted to determine whether eye patching affected the pain of simple corneal abrasions. After fluorescein examination with magnification (x 5), a visual analog pain score was recorded and the patient was randomized to either the patched or nonpatched group. A standard analgesic was supplied, and all patients had follow-up at 24 hours, when repeat pain scores and analgesic use were recorded. The groups were compared by using the Wilcoxon's rank sum test, Student's t test, and analysis of covariance as required. There was no significant difference in the mean changes in pain scores between the patched and nonpatched groups. Analgesic use was also similar. We conclude that routine eye patching does not favorably affect the pain associated with the treatment of simple corneal abrasion.

Administration, Topical↗

PubMed1996

A newly identified immunodominant membrane protein (pMB67) involved in Mycoplasma bovis surface antigenic variation.

Mycoplasma bovis is a bovine pathogen able to cause systemic disease. It possesses a series of prominent, structurally related yet clearly distinguishable membrane lipoproteins on the cell surface. These variable surface proteins (Vsps) undergo highly dynamic and spontaneous changes in size and expression and are key immunogenic components. They may play a critical role as mediators of adherence to host cells and in escaping immune destruction. In this report, we define a novel, Vsp-unrelated membrane protein also associated with M. bovis surface antigenic variation. This protein has an apparent molecular mass of 67,000 Da in the type strain PG45 and was designated pMB67. Immunological and biochemical characterization of pMB67 demonstrated that it: (i) contains a specific epitope, (ii) is not modified by lipid but does contain cysteine, (iii) does not contain a Vsp-like repetitive periodic protein structure, (iv) is a predominant antigen recognized during M. bovis infections, (v) undergoes a high rate of phase variation in vitro and (vi) is size-variable. These results showed that M. bovis employs two types of specialized membrane proteins for surface diversification. The pMB67 protein may be useful in diagnostic assays and as a vaccine component.

Animals↗

PubMed1996

Immunoelectron microscopic localization of variable proteins on the surface of Mycoplasma bovis.

The ultrastructural distribution and immunological accessibility of the variable surface proteins VspA, VspB, VspC and VspD were determined by immunoelectron microscopy on the surface of negatively stained cells of Mycoplasma bovis PG45 and 18 subclones, expressing either one or two of the Vsps. The variable proteins VspA, VspB, VspC and VspD, recognized by two monoclonal antibodies (mAb 1E5 and mAb 87-2) and visualized by goat-anti-murine-lgM labelled with gold particles, showed identical distribution patterns on the surfaces of the cells of all M. bovis clones investigated. Gold particles were distributed over the whole cell surface, arranged in clusters. The cell form seemed not to have an influence on the decoration pattern. Gold particles were also observed in irregular distributions around the cells. All clones showed unlabelled cells as well as strongly and weakly labelled cells. There were in general, however, no significant differences in the percentages of unlabelled, weakly labelled and strongly labelled cells, either between clones expressing different Vsps or between individual clones. No correlations were found between the numbers of labelled cells in immunoelectron microscopy and the numbers of labelled colonies in immunobinding assay (IBA) originating from the same broth cultures. The percentage of positive colonies in IBA was generally much higher than the percentage of positive cells in immunoelectron microscopy. The results show that the cells of the M. bovis clones are not identical, but differ in their surface antigens, and reveal the high variable potential of this species.

Animals↗

PubMed1996

Dacron-covered stent-grafts for the percutaneous treatment of carotid aneurysms: effectiveness and biocompatibility--experimental study in swine.

PURPOSE: To evaluate the short-term effectiveness and biocompatibility of Dacron-covered stent-grafts for percutaneous treatment of carotid aneurysms. MATERIALS AND METHODS: In eight swine, nine aneurysms were created surgically in the common carotid artery. Percutaneous treatment was performed with Dacron-covered stent-grafts. Seven of eight swine underwent follow-up angiography at 2, 3, 4, and 5 weeks after stent implantation. Histologic examinations of tissue from the site of stent implantation were performed at the same intervals. RESULTS: Initial closing off of the aneurysm was possible in all swine. Angiographic follow-up revealed patency of only one Dacron-covered stent-graft after 2 weeks. In six of seven swine, the stent was occluded on the follow-up angiogram. One of the swine died of unclear cause after 1 week. The stent-graft of this swine was not occluded. In all Dacron-covered stent-grafts, inflammatory reaction with granulocyte infiltration was found next to the Dacron material. CONCLUSION: Primary treatment of carotid aneurysms with Dacron-covered stent-grafts is effective. However, the short-term patency rate is poor, which probably can be attributed to the limited biocompatibility of the Dacron cover. An acute inflammatory reaction against Dacron seems responsible for the poor patency rate.

Angiography, Digital Subtraction↗

PubMed1996

[The initial results of percutaneous therapy of popliteal aneurysms with stents].

PURPOSE: Are percutaneous stents a therapeutic alternative to bypass surgery in the treatment of popliteal aneurysms? MATERIAL AND METHODS: Three patients with femoropopliteal occlusion related to popliteal aneurysms were treated percutaneously. In two cases coated stents were used. In the third patient who underwent prior bypass surgery due to local fibrinolysis a reperfusion of the aneurysm occurred. He was treated with a Wallstent. RESULTS: Primary stent treatment was successful in all cases. There were no complications. One patient was lost to follow-up. One of the two coated stents occluded after one month due to a poor run-off of only one lower limb artery. The other coated stent is still patent after 6 months proven by angiography. CONCLUSION: Percutaneous therapy with coated stents could be an alternative to surgical bypass therapy for popliteal aneurysms. Obviously long-time patency is related to sufficient run-off.

Aged↗

PubMed1996

Localized epidermolysis bullosa acquisita of the esophagus in a patient with Crohn's disease.

Epidermolysis bullosa acquisita is a rare autoimmune subepidermal bullous disease that affects both the skin and mucosae and is frequently associated with Crohn's disease. We report the case of a 27-yr-old man with Crohn's disease who presented with localized epidermolysis bullosa acquisita of the esophagus, without any other mucosal or cutaneous lesions. The patient was successfully treated with sulfasalazine.

Adult↗