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Biomedical subjects

I Baumgartner

Publications and source records attributed to I Baumgartner.

At least 55 records · Page 3Linked to original sources
PubMed1999

Performance of a new fibrin monomer assay to exclude deep vein thrombosis in symptomatic outpatients.

UNLABELLED: In this study we prospectively assessed the reliability of a new fibrin monomer assay in 106 outpatients with clinically suspected deep venous thrombosis of the lower limb. According to the results of the objective tests and using different cut-off points we calculated the sensitivity, specificity and negative predictive value of the fibrin monomer assay. The prevalence of deep vein thrombosis was 44.3% (31.1% proximal, 13.2% distal). Using a cut-off level of plasma fibrin monomer of 3.5 microg/ml, a sensitivity, specificity and negative predictive value of 100% (95% CI: 94-100%), 35.6% (95% CI: 23-48%) and 100% (95% CI: 86-100%), respectively, were obtained. The exclusion rate was 19.8% (95% CI: 12-27%) of all referred patients. These accuracy indices compared favourably with the respective results of a routine D-dimer ELISA used for comparison. CONCLUSION: This new fibrin monomer assay appears to be a reliable method for the exclusion of deep vein thrombosis in symptomatic outpatients.

Adolescent↗
PubMed1998

Constitutive expression of phVEGF165 after intramuscular gene transfer promotes collateral vessel development in patients with critical limb ischemia.

BACKGROUND: Preclinical studies have indicated that angiogenic growth factors can stimulate the development of collateral arteries, a concept called "therapeutic angiogenesis." The objectives of this phase 1 clinical trial were (1) to document the safety and feasibility of intramuscular gene transfer by use of naked plasmid DNA encoding an endothelial cell mitogen and (2) to analyze potential therapeutic benefits in patients with critical limb ischemia. METHODS AND RESULTS: Gene transfer was performed in 10 limbs of 9 patients with nonhealing ischemic ulcers (n=7/10) and/or rest pain (n=10/10) due to peripheral arterial disease. A total dose of 4000 microg of naked plasmid DNA encoding the 165-amino-acid isoform of human vascular endothelial growth factor (phVEGF165) was injected directly into the muscles of the ischemic limb. Gene expression was documented by a transient increase in serum levels of VEGF monitored by ELISA. The ankle-brachial index improved significantly (0.33+/-0.05 to 0.48+/-0.03, P=.02); newly visible collateral blood vessels were directly documented by contrast angiography in 7 limbs; and magnetic resonance angiography showed qualitative evidence of improved distal flow in 8 limbs. Ischemic ulcers healed or markedly improved in 4 of 7 limbs, including successful limb salvage in 3 patients recommended for below-knee amputation. Tissue specimens obtained from an amputee 10 weeks after gene therapy showed foci of proliferating endothelial cells by immunohistochemistry. PCR and Southern blot analyses indicated persistence of small amounts of plasmid DNA. Complications were limited to transient lower-extremity edema in 6 patients, consistent with VEGF enhancement of vascular permeability. CONCLUSIONS: These findings may be cautiously interpreted to indicate that intramuscular injection of naked plasmid DNA achieves constitutive overexpression of VEGF sufficient to induce therapeutic angiogenesis in selected patients with critical limb ischemia.

Adult↗
PubMed1998

Treatment of thromboangiitis obliterans (Buerger's disease) by intramuscular gene transfer of vascular endothelial growth factor: preliminary clinical results.

PURPOSE: Thromboangiitis obliterans (TAO), or Buerger's disease, a distinct form of vascular occlusive disease that afflicts the peripheral arteries of young smokers, is often characterized by an inexorable downhill course even in patients who discontinue smoking once a stage of critical limb ischemia associated with ulceration or gangrene is reached. As part of a phase I clinical trial to document the safety and efficacy of intramuscular gene transfer of naked plasmid DNA-encoding vascular endothelial growth factor (phVEGF165) in the treatment of critical limb ischemia, we treated TAO in 6 patients. METHODS: Seven limbs in 6 patients (3 men, 3 women; mean age, 33 years; range, 33 to 51 years) who satisfied the criteria for TAO and had signs or symptoms of critical limb ischemia were treated twice, 4 weeks apart, with 2 or 4 mg of phVEGF165, which was administered by direct intramuscular injection at 4 arbitrarily selected sites in the ischemic limb. The gene expression was documented by enzyme-linked immunosorbent assay that was performed on peripheral blood samples. RESULTS: The ulcers that were nonhealing for more than 1 month healed completely in 3 of 5 limbs after the intramuscular phVEGF165 gene therapy. Nocturnal rest pain was relieved in the remaining 2 patients, although both continue to have claudication. The evidence of the improved perfusion to the distal ischemic limb included an increase of more than 0.1 in the ankle brachial index in 3 limbs, an improved flow shown with magnetic resonance imaging in 7 of the 7 limbs, and newly visible collateral vessels shown with serial contrast angiography in 7 of the 7 limbs. The adverse consequences of the phVEGF165 gene transfer were limited to transient ankle or calf edema in 3 of the 7 limbs. Two patients with advanced distal forefoot gangrene ultimately required below-knee amputation despite the evidence of improved perfusion. A histologic section disclosed the classic pathologic findings of TAO. CONCLUSION: Therapeutic angiogenesis with phVEGF165 gene transfer, if instituted before the development of forefoot gangrene, may provide a novel therapy for patients with advanced Buerger's disease that is unresponsive to standard medical or surgical treatment methods.

Adult↗
PubMed1998

Influence of dorzolamide on corneal thickness, endothelial cell count and corneal sensibility.

PURPOSE: Dorzolamide (Trusopt) is the first topical carbonic anhydrase inhibitor (CAI) that is in clinical use in glaucoma therapy. It is known that CAI have a negative effect on corneal endothelial pumpfunction and therefore on the whole corneal physiology. METHODS: 20 patients with open angle glaucoma or ocular hypertension and an elevated intraocular pressure (IOP) over 21 mmHg and without prior oral CAI-treatment were included in this study. Trusopt was administered t.i.d. as monotherapy and b.i.d. in combination with other topical antiglaucoma drugs. Corneal ultrasound pachymetry, corneal endothelial cell count and aesthesiometry were performed prestudy and on days 1, 8, 15, 30, 60 and 90. RESULTS AND CONCLUSIONS: Mean corneal thickness was slightly increased on day one (statistically non-significant) and returned to baseline measurements at the following visits, no changes in endothelial cell count and corneal anesthesia were found. Topical dorzolamide is not associated with clinically meaningful changes of the cornea.

Administration, Topical↗
PubMed1998

In vitro effectiveness of silicone oil removal.

PURPOSE: To evaluate the effectiveness of silicone oil removal from the human eye under in vitro conditions. METHODS: Six keratoplasty donor eyes were vitrectomized and filled with silicone oil (5000 centistokes). After oil removal, the amount of residual oil was determined by quantifying the silicon content of the eyes. Six control eyes were prepared without oil filling. RESULTS: The six control specimens showed a silicon content of 2.83-10.2 microg (mean 5.06 microg, SD 3.19), the six test specimens a silicon content of 70.54-297.10 microg (mean 163.91 microg, SD 86.89). The difference is significant (p<0.05). The amount of residual oil in the test eyes was 192.0-856.2 microg (0.0037-0.0179% of the applicated oil quantity). CONCLUSION: The low magnitude of residual intraocular oil after oil removal shows that silicone oil could be removed to almost 100% when emulsification and biological mechanisms of oil retention are excluded. This could favour early silicone oil removal.

Cadaver↗
PubMed1998

Vasomotor reactivity is exhausted in transient ischaemic attacks with limb shaking.

OBJECTIVES: To investigate cerebral vasomotor reactivity in five patients with limb shaking transient ischaemic attacks by using transcranial Doppler sonography. METHOD: Attacks with transient limb shaking were unilateral in four patients and bilateral in one. Internal carotid arteries on the side opposite the abnormal limb movements showed three 90-95% stenoses and three occlusions as assessed by cerebral angiography in three and magnetic resonance angiography and ultrasound in one case each. Reactivity of cerebral resistance vessels was studied by measuring peak mean velocities in the middle cerebral artery (MCA) before and after the application of CO2 enriched air. Reference values were obtained from 25 normal subjects. RESULTS: During hypercapnia peak mean velocities slightly decreased in five MCAs (steal phenomenon) and remained unchanged in one MCA opposite the abnormal movements, whereas the other MCAs showed normal reactivities. CONCLUSION: The delineation of an exhausted cerebral vasoreactivity in all hemispheres opposite the involuntary limb movements suggests that haemodynamic failure is the cause of transient ischaemic attacks with limb shaking.

Aged↗
PubMed1998

A New Approach to Plaque Removal: The Redha-Cut Device.

PURPOSE: To prospectively determine the safety, feasibility and efficacy of a new atherectomy device. Methods. Seventy patients with 93 symptomatic femoro-popliteal lesions underwent percutaneous atherectomy with Redha-cut, a metallic, flexible catheter. The device works on pull-back with two umbrella-like blades and enables cutting, retaining and removing of material. Quantitative analysis of the angiograms was performed. RESULTS: Obtaining of atherectomized samples was successful in all cases. The mean atherectomy time was 5 +/- 2 minutes. The stenoses were reduced from 74 +/- 2.3% before to 26 +/- 2% after atherectomy (p < 0.001). Subsequent PTA, which was performed to optimize the results, further decreased the degree of stenosis to 17% (p > 0.5). No perforations, acute closure or early re-thrombosis occurred. Cumulative patency rates according to the findings of non-invasiveive examinations were 83% at 6 months and 66% at 12 months. Conclusions. The Redha-cut device is a simple, safe and efficacious tool for biopsy sampling and atherectomy. Further studies randomizing patients either to balloon or atherectomy are planned to compare this technique with others in regard to long-term patency.

Journal Article↗
PubMed1998

Power-based colour coded duplex sonography for evaluation of calf veins.

BACKGROUND: Power-based colour coded duplex sonography (PD) has been described to display lower flow velocities compared to frequency-based colour coded duplex sonography (CD). This study was undertaken to study the clinical usefulness of PD in the evaluation of calf veins in suspected deep vein thrombosis. METHODS EXPERIMENTAL DESIGN: A prospective, comparative study. SETTING: University hospital, Switzerland. PATIENTS AND MEASURES: CD of the complete deep venous system and complementary PD of paired calf veins were performed in 50 consecutive patients with clinically suspected DVT. All except three patients, with failed vein puncture at the dorsum of the foot, had a venography used as reference test for confirmatory diagnosis of DVT. RESULTS: Complete identification of calf veins increased from 80.5% using CD to 97.9% using complementary PD (p=0.007). Overall accuracy to detect an acute calf DVT was 96% (95% Ci, 85-99%) and 95% (95% CI, 83-99%), respectively. Accuracy was 95% (95% CI, 83-99%) using CD vs 94% (95% CI, 82-98%) using PD in posterior tibial, 87% (95% CI, 74-95%) vs 85% (95% CI, 71-94%) in anterior tibial, and 95% (95% CI, 83-99%) vs 96% (95% CI, 85-99%) in peroneal veins. Chronic post-thrombotic changes (10.6%) were more reliably recognized using CD (accuracy 83% [95% CI, 72-94%]) compared to PD (accuracy 66% [95% CI, 59-85%]) due to tissue motion artifacts and inability to discriminate the direction of blood flow. CONCLUSIONS: PD used complementary with CD is capable of significantly improving identification of paired calf veins without loss of diagnostic accuracy in the diagnosis of acute DVT.

Blood Flow Velocity↗
PubMed1998

Discrepancy of clinical and angiographic results in the follow-up of percutaneous transluminal renal angioplasty (PTRA).

BACKGROUND: To investigate the value of recurrent hypertension as indicator for renal artery patency after PTRA clinical and angiographic follow-up results were analysed. PATIENTS AND METHODS: results of 66 follow-up angiographies and blood pressure measurements were available in 55 patients after technically and clinically successful PTRA. Out of 43 patients with atherosclerosis, in 33 was recurrent hypertension present, and in ten patients none. Of 12 angiographies in patients with fibromuscular dysplasia nine were done because of recurrent hypertension. RESULTS: In atherosclerosis, 21 (64%) out of 33 patients with recurrent hypertension showed a re-stenosis by > 70%, and 12 (36%) none. Out of the ten follow-up angiographies performed in patients with no recurrence, two showed an unexpected stenosis. In fibromuscular dysplasia, stenoses were present in seven cases (77%). Four of them were at the site of PTRA (44%), while three were at a new site (33%). The follow-up angiographies in three patients with no recurrence showed patent arteries. Out of 11 further angiographies carried out because of hypertension after repeated PTRA, only three revealed re-stenosis. CONCLUSIONS: In only about 35% of all patients with recurrent hypertension re-stenosis was shown in angiography but in 15% of asymptomatic patients. Recurrence of hypertension after PTRA and renal artery stenosis is not well correlated. Thus, follow-up should be performed not only clinically but also by direct examination of renal artery patency such as by ultrasound.

Adult↗
PubMed1998

Stimulation of peripheral angiogenesis by vascular endothelial growth factor (VEGF).

Angiogenic growth factors constitutes a potentially novel form of therapy for patients with ischemic vascular disease. The feasibility of using recombinant formulations of angiogenic growth factors to augment collateral artery development by stimulation of capillary growth in animal models of myocardial and hindlimb ischemia has now been well established. In the case of vascular endothelial growth factor (VEGF) similar results may be achieved by gene transfer. Further laboratory and clinical studies may yield promising insights into the fundamental basis for native as well as therapeutic angiogenesis, and at the same time more explicitly define the manner in which therapeutic angiogenesis may be successfully incorporated into clinical practice.

Animals↗
PubMed1997

Langerhans'-cell histiocytosis in adults.

Guided by a long-term retrospective observation, the clinical course and treatment of Langerhans'-cell histiocytosis (LCH) in adult patients are represented. The series included 19 patients meeting the histopathologic criteria of presumptive LCH who were followed for 1.5-20 years (average 7.7 years). Most frequently, skeletal lesions (16 patients), diffuse interstitial lung infiltrates (seven patients), and pituitary gland involvement with diabetes insipidus (four patients) were present. Bone lesions of the skull and axial skeleton were associated with an infiltration of adjacent soft tissues in 10 of 16 patients. Liver, lymph node, and bone marrow involvement appeared sporadically. LCH was divided into localized or multifocal form. Localized disease took a benign course with remission of bone (n = 4) or lymph node lesions (n = 2). Also, in isolated pulmonary LCH (n = 2), spontaneous transition to inactive disease occurred. With the exception of isolated bone lesions (n = 27), which remained asymptomatic or showed a remission to treatment, multifocal LCH had a more aggressive course. Osseous lesions with adjacent soft tissue infiltration (n = 20) showed a relapse rate in excess of 80% independent of the treatment applied. Pulmonary involvement led to a more marked functional impairment compared to the isolated form, and systemic treatment yielded no convincing effect. In three patients with liver or bone marrow involvement, LCH showed a persistent, serious disease activity. One patient died of transition into acute monomyelocytic leukemia 18 months after diagnosis without preceding chemotherapy. In adults, LCH seems to be limited to a few organ systems. Multifocal LCH represents the more aggressive form with unfavorable prognosis in patients with bone lesions spreading into the adjacent soft tissue and liver or bone marrow involvement.

Adult↗
PubMed1997

The mydriatic effect of tropicamide and its diagnostic use in Alzheimer's disease.

The mydriatic effect of topically administered tropicamide was investigated as a possible diagnostic indicator for Alzheimer's disease. Although an initial series seemed to show a correlation between hypersensitivity to tropicamide and intellectual impairment, subsequent testing showed a greater inter- and intra-individual variation than that between the normal group and the group of patients with intellectual impairment. This procedure seems, therefore, to lack sufficient specificity to be useful for such a diagnostic purpose.

Aged↗
PubMed1997

Patency of percutaneous transluminal renal angioplasty: a prospective sonographic study.

Evaluation of percutaneous transluminal renal angioplasty (PTRA) is today based primarily on clinical criteria rather than direct investigation of luminal width. In this study, we examined renal blood flow by color-coded duplex sonography (CCD) in order to correlate blood pressure as well as renal function with the true renovascular patency. Fifty consecutive patients suspected of suffering from renovascular disease and treated by PTRA were included for a prospective sonographic study. In all PTRA was performed on 63 renal arteries. Thirty-seven patients were diagnosed to have atherosclerosis and 13 patients to have fibromuscular dysplasia (FMD). Examinations were performed using CCD before PTRA, and one day, three months, six months and 12 months after PTRA. If CCD showed a restenosis > or = 60%, CCD was non-conclusive or hypertension deteriorated, angiography and, if necessary, catheter re-intervention were performed. The primary patency rate after 12 months was 73%, and could be improved to 94% overall when treated restenosis (N = 22) were included. Restenosis was more frequent in patients with mild residual stenosis identified by CCD one day after PTRA (P = 0.002). There was neither a significant difference in the restenosis rate in patients with atherosclerosis versus FMD, nor in patients with ostial versus non-ostial lesions. Hypertension was improved or cured in 70% of patients with atherosclerosis, and in 85% of those with FMD. Nevertheless, hypertension deteriorated in 12% of the patients without restenosis, and no deterioration was present in 14% of the patients with restenosis. A decrease in serum creatinine levels by more than 15% was observed in 12 of 22 patients with impaired renal function and patent renal artery during follow-up. These results suggest that optimal therapeutic efficiency can be obtained using PTRA followed by systematic CCD.

Adult↗
PubMed1997

[Proprioception of extra-ocular muscles in the human: on the morphology of muscle spindles].

BACKGROUND: Increasing importance is attributed to the proprioceptive innervation of extraocular muscles for the development of binocular vision. In the literature, data on proprioceptors in human extraocular muscles are rare and inconsistent. Therefore a detailed morphological analysis of spindles in human extraocular muscles appeared indicated. MATERIAL AND METHODS: Complete serial sections of all extraocular muscles of 3 human individuals, 67, 72, and 83 years of age, were alternately impregnated with silver, stained following Mowry and immunohistochemically stained for S100 or PGP 9.5. Distal parts of extraocular muscles from multiorgan donors, 2, 17, and 34 years of age, were prepared for electron microscopy. RESULTS: Spindles contained 1 to 18 intrafusal muscle fibers, 55% of which were nuclear chain fibers, 2% nuclear bag fibers, and 43% fibers exhibiting the same morphological features as extrafusal fibers. The latter had been previously described as "anomalous fibers" (Ruskell). This intrafusal type exclusively occurs in human extraocular muscle spindles. Ultrastructural analysis revealed morphologically normal sensory terminals on all 3 types of intrafusal fibers. Findings in a two-year-old individual were similar to those in aged individuals. CONCLUSIONS: Spindles in human extraocular muscles are specifically structured. Their special morphological features are also present during the development of binocular vision. Spindles are supposed to play a role in the (fine) control of eye movements.

Adolescent↗
PubMed1997

Adventitial cystic disease of the popliteal artery: percutaneous US-guided aspiration.

PURPOSE: To evaluate percutaneous ultrasound (US)-guided aspiration as an alternative therapy for adventitial cystic disease. MATERIALS AND METHODS: Between September 1993 and June 1996, seven patients (six men, one woman; age range, 42-62 years; mean age, 48 years) presented with symptomatic adventitial cystic disease of the popliteal artery (one patient with subacute foot paresthesia, six patients with chronic calf claudication). Color Doppler sonography showed stenosis due to eccentric cysts. Five of the patients also underwent digital subtraction angiography, and four patients underwent magnetic resonance imaging. With real-time sonographic guidance, a 14-gauge needle was forwarded percutaneously into the cysts for aspiration. The aspiration procedure was performed on an outpatient basis with local anesthetics. RESULTS: The procedure was technically and clinically successful in all cases. No complications were noted. Follow-up color duplex sonography performed between 1 and 32 months (mean, 14.8 months) after the procedure showed no relevant recurrent stenosis. CONCLUSION: Percutaneous US-guided aspiration is an easy, safe, efficacious method for treating adventitial cystic disease. In symptomatic patients who do not have thrombotic occlusion, it may be considered the treatment of choice.

Adult↗
PubMed1997

Transcranial color-coded duplex sonography in the evaluation of collateral flow through the circle of Willis.

PURPOSE: To determine the sensitivity, specificity, and positive and negative predictive values of transcranial color-coded duplex sonographic (TCCD) evaluation of cross flow through the anterior (ACoA) and posterior (PCoA) communicating arteries in patients with occlusive cerebrovascular disease. METHODS: We studied prospectively 132 patients (37 women, 95 men; mean age, 60 years) with stenoses of more than 69% reduction in vessel diameter (n = 93) and occlusions (n = 52) of the internal carotid artery, and three occlusions of the basilar artery. The sonographer was aware of extracranial sonographic findings but was blinded to the results of cerebral angiography. RESULTS: Nine patients (7%) with thick bones preventing transtemporal insonation and three patients (3%) with occlusions of the middle (n = 3) and anterior (n = 1) cerebral arteries were excluded. Sensitivity of TCCD for detection of collateral flow through the ACoA in patients with occlusive carotid artery disease was 98%, specificity was 100%, positive predictive value was 100%, and negative predictive value was 98%. The corresponding values for the PCoA were 84%, 94%, 94%, and 84%, respectively. All three functional PCoAs were identified in patients with occluded basilar arteries. CONCLUSION: TCCD is a valuable method for noninvasive evaluation of cross flow through the ACoA in patients with adequate sonographic windows. However, TCCD evaluation of cross flow through the PCoA is less reliable, because hemodynamic criteria may cause falsely positive and falsely negative results.

Adult↗
PubMed1997

Blue toes due to floating plaque of the abdominal aorta: endovascular repair with stent.

A 60 year old male patient was admitted with so-called blue toes on both sides. Investigation, including real-time ultrasound, revealed a floating plaque on the dorsal side of the abdominal aorta as the most probable cause of the blue toes. By means of simultaneous fluoroscopy and ultrasound guided implantation of a stent it was possible to restore a free lumen of the aorta. The patient had an uncomplicated recovery. Post-operative colour coded Doppler ultrasound showed normal flow in the aorta. Follow-up examination one year after the procedure demonstrated no evidence of further embolic events and a patent aorta.

Aorta, Abdominal↗