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Biomedical subjects

I Baumgartner

Publications and source records attributed to I Baumgartner.

At least 73 records · Page 4Linked to original sources
PubMed1996

Diagnostic criteria for transcranial colour-coded duplex sonography evaluation of cross-flow through the circle of Willis in unilateral obstructive carotid artery disease.

A transcranial colour-coded duplex sonography (TCCD) study was performed to establish reliable criteria for the assessment of collateral flow through the anterior (ACoA) and posterior (PCoA) communicating artery without using compression tests. We studied 86 patients with angiographically evaluated unilateral > 69% stenosis (n = 53) and occlusion (n = 33) of the carotid artery. The following TCCD criteria were evaluated: for diagnosis of cross-flow through the ACoA, detection of reversed flow in the anterior cerebral artery (ACA) on the obstructed (ipsilateral) side. For the diagnosis of cross-flow through the PCoA: (A) identification of the PCoA; (B) peak systolic velocity in P1 posterior cerebral artery (PCA) higher than the mean value + 2 SD of normals; (C) ratio of ipsilateral peak systolic P1 PCA velocity to peak systolic P1 PCA velocity to peak systolic P2 PCA velocity higher than the mean ratio + 2 SD of normals; (D) ratio of ipsilateral peak systolic P1 PCA velocity to contralateral peak systolic P1 PCA velocity higher than the mean ratio + 2 SD of normals; (E) peak systolic basilar artery velocity higher than the mean value + 2 SD of normals. Eight patients (9%) with inadequate temporal ultrasonic windows were excluded. The sensitivity and specificity for TCCD evaluation of ACoA cross-flow were 100%. Using criteria A and B the corresponding values for the PCoA were 85 and 98%, respectively. Criteria C-E were not useful owing to lower sensitivity. In conclusion, we delineated TCCD criteria that make it possible to assess reliably the cross-flow through the circle of Willis in patients with adequate ultrasonic windows.

Adult↗
PubMed1996

Ultrasonic-pathologic comparison of postangioplasty myointimal hyperplasia and primary atheroma of the superficial femoral artery.

The purpose of this study was to characterize postangioplasty myointimal hyperplasia as compared to primary atheroma of superficial femoral arteries using color-coded duplex sonography (CCD), and to correlate sonographic findings with the histopathology of samples obtained from these lesions by catheter atherectomy (Redha-cut device). Preinterventionally, homogeneity, echogeneity, and the surface of plaques were described using CCD in nine cases with secondary stenoses after percutaneous transluminal angioplasty and in seven cases with primary atheroma. Myointimal hyperplasia of femoral restenoses showed a homogeneous (7 of 9 vs. 1 of 7) and hypoechogenic (7 of 9 vs. 0 of 7) wall thickening compared to primary atheromas (p < 0.05). Primary atherosclerotic plaques showed a rather heterogeneous, hypo- and hyperechogenic ultrasonic appearance with or without echo shadowing in six of seven cases. The surface of restenoses was more often regular than that of primary atherosclerotic lesions, but this finding did not reach statistical significance (6 of 9 vs. 2 of 7, p = 0.14). Thrombotic material appeared homogeneous and hypoechogenic in three of five cases and could not be discriminated from intimal hyperplasia. In summary, postangioplasty intimal hyperplasia is characterised by a hypoechogenic, homogeneous, rather regularly confined vessel wall thickening and can be differentiated from primary atheroma at CCD.

Aged↗
PubMed1996

Detection of allergen-specific IgE in tears of grass pollen-allergic patients with allergic rhinoconjunctivitis.

BACKGROUND: Allergic conjunctivitis is a common symptom amongst Type I (IgE-mediated) allergic diseases; and most frequently seen as rhinoconjunctivitis. However, the site of production and the significance of allergen specific IgE needs further elucidation. OBJECTIVE: We investigated whether the presence of IgE in tears of grass pollen allergic patients correlated with disease and clinical symptoms, whether the IgE binding pattern to the different grass pollen antigens was different in sera and tears, and whether IgA antibodies to grass pollen allergens were present in tears. Finally, we looked whether specific IgE was produced locally or was exudated from serum. METHODS: Sera from 44 grass pollen allergic patients suffering from either allergic rhinitis (n = 11) or allergic rhinoconjunctivitis (n = 33) and from healthy controls (n = 7) were used for the experiments. Binding of specific IgE and IgA antibodies to the different groups of grass pollen allergens (Phleum pratense) was evaluated by means of immunoblotting. RESULTS: Specific IgE was detected in sera as well as in tears of allergic patients, whereby tear-derived allergen-specific IgE exerted similar specificities to the corresponding IgE from serum. The correlation between symptoms of ocular allergy and the presence of allergen-specific IgE in tears was highly significant (P < 0.0001). In contrast, only a poor correlation was found between specific and/or total IgE in sera and the manifestation of ocular allergy (P = 0.73). CONCLUSION: Allergen-specific IgE antibodies in tears seem to be produced locally rather than exudated from serum. IgE in tears seems to be responsible for allergic conjunctivitis. IgA in tears cannot exert a protective function since the IgA antibodies recognize different antigens in a grass pollen (Phleum pratense) extract than IgE antibodies. The highly significant correlation between allergic conjunctivitis and the presence of specific tear IgE emphasizes the diagnostic value of immunoblots with tear IgE, especially in cases in which serum provides inconclusive results.

Allergens↗
PubMed1996

Comparative study of power-based versus mean frequency-based transcranial color-coded duplex sonography in normal adults.

BACKGROUND AND PURPOSE: Power-based transcranial color-coded duplex sonography (p-TCCD) is a new ultrasonic method that has advantages compared with frequency-based TCCD (f-TCCD), since it is essentially independent of the angle of insonation, not subject to aliasing, and has a better signal-to-noise ratio. The purpose of this study was to evaluate the ability of p-TCCD to visualize flow in cerebral parenchyma and to compare the advantages, limitations, and reliability of velocity measurements of p-TCCD versus f-TCCD in the major basal cerebral arteries of normal subjects. METHODS: Two investigators performed 15 p-TCCD and 15 f-TCCD studies in 30 normal subjects with adequate ultrasonic windows. Each investigator did a p-TCCD or f-TCCD study in every patient, and each was blinded in every case to the results of the other. Peak systolic (Vs) and end-diastolic (Vd) velocities were determined in the anterior, middle, and posterior cerebral, basilar, and vertebral arteries. The reliability of p-TCCD velocimetry was evaluated by calculating both the correlation coefficient (r) of the difference between p-TCCD versus f-TCCD measurements and the coefficient of variation (CV), defined as the difference between the mean values for p-TCCD and f-TCCD divided by the mean values for f-TCCD measurements, expressed as percent. RESULTS: p-TCCD did not display flow in cerebral parenchyma but depicted arteries with a course perpendicular to that of the ultrasound beam and showed good reliability of velocity measurements in all examined arteries: for Vs, r was .84 to .93 (P < .001) and CV was 7.7% to 10.8%; for Vd, r was .87 to .90 (P < .001) and CV was 10.3% to 13.7%. The lack of directional and velocity information and tissue motion artifacts were unimportant limitations in p-TCCD. CONCLUSIONS: Compared with f-TCCD, p-TCCD had no important advantages but had several unimportant limitations in a study of normal adults with adequate ultrasonic windows.

Adult↗
PubMed1996

[Assessment of deep venous thrombosis].

Deep vein thrombosis (DVT) is a frequent disorder, which should not be missed diagnostically because of the associated morbidity and mortality due to pulmonary embolism and the postthrombotic syndrome. Clinical diagnosis is unreliable. Because of the possible risks a treatment by anticoagulation should not be undertaken without objective confirmation of DVT. Venography is generally considered as the gold standard for the diagnosis of DVT, but is invasive and associated with side effects. Noninvasive cw-Doppler ultrasound and the plethysmography are simple methods, but the accuracy is sufficient only for symptomatic proximal DVT and not for isolated DVT of the calf. In the past few years (color-coded) venous duplex imaging gained increasing importance. It is a noninvasive test with an accuracy comparable to that of venography. In addition to vascular changes perivascular structures can be investigated. B-mode compression sonography has a comparable accuracy for symptomatic proximal DVT.

Humans↗
PubMed1996

Transcranial color-coded duplex sonography in unilateral flow-restrictive extracranial carotid artery disease.

PURPOSE: To provide transcranial color-coded duplex flow-velocity data for the basal cerebral arteries in patients with unilateral flow-restrictive extracranial carotid artery disease, and to compare these data with the flow velocities obtained in healthy control subjects. METHODS: Transcranial color-coded duplex sonography was performed in 78 patients with different patterns of cross flow through the anterior and posterior communicating arteries associated with unilateral obstruction (70% to 100%; 46 stenoses and 32 occlusions) of the internal carotid arteries. Peak systolic, mean, and end diastolic velocities were measured in the anterior, middle, and precommunicating and postcommunicating posterior cerebral arteries. These measurements were compared with the values obtained in 125 age- and sex-matched health control subjects. RESULTS: Patients with anterior communicating artery cross flow to the middle cerebral artery (63%) had increased peak velocity in the anterior cerebral artery and decrease peak velocity in the middle cerebral artery on the obstructed (ipsilateral) side, and increased peak velocity in the anterior cerebral artery on unobstructed (contralateral) side. Patients with anterior communicating artery cross flow to the pericallosal artery (19%) had increased contralateral peak systolic velocity and mean anterior cerebral artery velocities. Patients without anterior communicating artery cross flow (18%) had normal peak velocities in the anterior and middle cerebral arteries. Patients with posterior communicating artery cross flow (42%) had ipsilaterally decreased peak systolic and mean middle cerebral artery velocities and increased peak velocities in the precommunicating posterior cerebral artery. Patients without posterior communicating artery cross flow (58%) had ipsilaterally decreased peak systolic and mean middle cerebral artery velocities. CONCLUSION: Our findings suggest that typical abnormalities of basal cerebral artery flow velocities occur in patients with unilateral 70% to 100% obstruction of the internal carotid arteries resulting in different patterns of cross flow through the circle of Willis.

Adult↗
PubMed1995

Melatonin synthesis in the retina and pineal gland of Djungarian hamsters at different times of the year.

Daily profiles of melatonin content in the retina of Djungarian hamsters were measured throughout the course of a year. Peak levels of retinal melatonin were found at various times of the day at different seasons. In a subsequent study we determined concurrently daily profiles of nine indole metabolites (tryptophan, 5-hydroxytryptophan, 5-hydroxytryptamin, 5-hydroxyindoleacetic acid, 5-hydroxytryptophol, N-acetylserotonin, melatonin, 5-methoxyindoleacetic acid and 5-methoxytryptophol) in samples of hamster retina and pineal gland at the four different seasons. Measurements were made using HPLC coupled to a coulometric electrode detection system. Large seasonal variations in the levels and daily rhythm amplitudes of the different indole metabolites were found in the pineal glands. Due to technical problems and unknown interfering substances only tryptophan and serotonin could be determined in the retinas at all four seasons. Despite this, the ability to measure levels of several metabolites in the same sample and in different tissues of the same animals permitted more accurate comparisons of the components involved in melatonin synthesis. Our data suggest that the level of retinal melatonin is regulated and controlled locally within the retina itself. However, long-term feedback mechanisms from other sources of melatonin are not excluded but are rather likely.

Animals↗
PubMed1995

Expression of MHC class II antigens on rat bone marrow cells and macrophages, and their modulation during culture with murine GM-CSF or M-CSF.

Flow cytometric analysis employing MRC OX 6 and MRC OX17 monoclonal antibodies recognizing determinants on RT1.B or RT1.D molecules, equivalent to murine I-A and I-E, respectively, was used to detect rat MHC class II antigen (Ag) expression. Approximately 5% of freshly isolated rat bone marrow cells (BMC) expressed RT1.B and over 30% displayed RT1.D molecules. The RT1.D+ cells were W3/13+, OX 7+, OX 19- and OX 22-. After one week culture of BMC with murine recombinant granulocyte/macrophage colony-stimulating factor (GM-CSF), regardless of concentrations, 90 to 95% of the cells were scored as bone marrow-derived macrophages (BMDM phi), and over 30% expressed both RT1.B and RT1.D Ag. GM-CSF increases the percentage of BMDM phi bearing MHC class II Ag in a concentration-dependent manner. This effect seems to be specific because antibodies to interferon-gamma, tumor necrosis factor-alpha or interleukin-4 did not reduce the number of cells expressing RT1.B and RT1.D Ag. Furthermore, GM-CSF was able to trigger expression of class II molecules on rat peritoneal macrophages (M phi) and BMDM phi resulted from cultures of BMC with mouse M phi-CSF (M-CSF), and the RT1.B and RT1.D inducing effect of GM-CSF was opposed by M-CSF, and by anti-GM-CSF antibodies. The induction of MHC class II Ag synthesis by GM-CSF on rat BMDM phi was confirmed at the mRNA level by Northern blot analysis employing cDNA probes encoding the RT1.B alpha.

Animals↗
PubMed1994

[Left heart insufficiency following acute myocardial infarct].

In the light of a case history, current treatment modalities for heart failure after acute myocardial infarction are described. Thrombolytics, beta-blocking agents and angiotensin-converting-enzyme inhibitors have radically changed the prognosis of acute myocardial infarction. A decrease in cardiac mortality and a marked reduction in cases with severe heart failure have been achieved with optimal use of modern therapy. In cases without sufficient improvement by pharmacotherapy, combination with cardiac surgery may lead to a favourable result. Left ventricular aneurysmectomy is the procedure of choice for large ventricular aneurysms with heart failure symptoms.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1994

Treatment of non-healing skin ulcers with autologous activated mononuclear cells.

The aim of this study was to investigate whether cultured autologous mononuclear cells (MNC) effectively initiate, accelerate and improve granulation and epithelialisation of skin ulcers. Thirty-three patients with chronic arterial occlusive disease (CAOD; n = 21) or venous post-thrombotic syndrome (PTS; n = 12) were treated with autologous MNC and compared with a control group of 30 patients who received tissue culture medium alone. Previous treatments had been unsuccessful for a mean of 9.23 (3-19) months. MNC were harvested from the peripheral blood of each patient by standard techniques, cultured for three days and applied to the ulcer twice a week. After 4.6 +/- 1.9 weeks, 29/33 ulcers were closed in the MNC group. Patients in the control group took 8.1 +/- 1.2 weeks for 17/30 ulcers. Thus ulcer healing was significantly speedier with MNC seeding; 48% of all ulcers were closed after 30 days of MNC treatment and 92% after 60 days. Patients with PTS responded significantly faster than patients with CAOD. In 90% of patients with painful ulcers MNC treatment resulted in pain relief, whereas in the control group only 50% of patients became pain-free.

Aged↗
PubMed1993

[Magnetic resonance arteriography, duplex sonography and conventional arteriography for the evaluation of peripheral arterial occlusive disease].

A prospective controlled study of 41 peripheral arterial occlusions was carried out, comparing duplex sonography, magnetic resonance arteriography and contrast arteriography. 87.8% of duplex sonography findings and 80.5% of magnetic resonance arteriographies agreed with the appearances of contrast arteriography (gold standard). Duplex sonography tended to overestimate the length of an occluded segment by an average of 2 cm (0.5-5 cm), whereas magnetic resonance arteriography showed less deviation from contrast arteriography (+/- 2 cm). The advantage of duplex sonography lies in its ability to provide morphological and functional information concerning the obliterated segment. Its disadvantage is that it can only demonstrate one segment and that the examination must be carried out in individual segments. Magnetic resonance arteriography provides vascular demonstration in several planes similar to angiography but signal-voids due to limited resolution and flow changes may limit diagnosis of occlusions. Additional phase contrast techniques may provide quantitative information on flow velocities and flow rates. Both duplex sonography and magnetic resonance arteriography are suitable methods for the non-invasive investigation of peripheral arterial occlusive disease.

Aged↗
PubMed1993

Automated digital image analysis of organ culture preserved donor corneas.

The present study reports the application of a modified commercially available automated digital image analysis system (DIA) for the evaluation of organ culture preserved donor corneas. The central corneal endothelium was viewed and photographed under an inverted phase-contrast microscope. The images were then analyzed with the help of DIA. The results of DIA were compared to the findings obtained with a conventional 'fixed-frame analysis' for the same corneas. 100 human donor corneas have been evaluated. DIA, with interactive picture enhancement, was found to be practicable, and to yield reproducible results. The mean number of cells analyzed per photograph was 250 (range 95-395); this, on the average, was four times higher than with conventional fixed-frame analysis (mean 54, range 37-70). The correlation of the cell densities obtained with both methods was highly significant (p < 0.0001). Since additional information, like variation in cell size and shape (circularity form factor), was automatically computed by the program, more data on the homogeneity of the donor endothelial cell pattern were available. Furthermore, this computerized technique does not require an experienced investigator and thereby helps to eliminate bias.

Cell Count↗
PubMed1992

[Corneal ulcer. Current analysis from specialized ambulatory care of a clinic].

A review of 115 cases of ulcerative keratitis that were diagnosed and treated at the specialized ambulatory care center for infectious eye diseases at the 2. Department of Ophthalmology over a period of eight years (January 1983-April 1991) is presented. In the analysis of the etiology nearly half (47.7%) were observed following a trauma to the epithelium, 38 (= 33.0%) were associated with contact lens wear and the third largest group (10.4%) was associated with lid problems. It is apparent that over the course of the last years the spectrum of microorganisms associated with this localized inflammation has shifted: the prevalence of Staphylococci (1983-1986 = 65%) has decreased, whereas the incidence of gram-negative rods increased (1987-1990 = 49%). In 19% Pseudomonas aeruginosa could be isolated, mostly associated with soft contact lens wear. A total of 37.5% of the staphylococci isolates were found to be resistant to gentamicin, most probably as a consequence of the widespread, indiscriminate use of this antibiotic. An updated treatment schedule is presented.

Ambulatory Care↗
PubMed1992

[Corneal sensibility following epikeratophakia].

The postoperative rate of reinnervation following corneal surgery is widely considered to be a useful indicator of the healing process. This study reports the corneal sensitivity of 14 patients following epikeratophakia for different indications (myopia, aphakia and keratoconus) after time periods ranging from 7 to 104 weeks. All transplants were clear at the time of measurement. A newly developed aesthesiometer (using a low electric current for stimulation) was employed. Nine positions on the operated eye were chosen for the measurements, five locations of the non-operated fellow eye served as controls. On the operated eye the corneal sensitivity peripheral to the trephination were significantly reduced at the 9 and 12 o'clock positions as compared to the other eye. The 3 and 6 o'clock locations showed no significant difference. On the epikeratophakia lenticule the sensitivity was significantly reduced at all points, the center showing the largest difference (p less than 0.001). No correlation with age, sex or the indication for the procedure was observed. Although there was a trend of a positive correlation between the postoperative time period and the central corneal sensitivity, the follow-up was too short to reach significant levels. The nearly complete lack of corneal sensitivity, particularly in the center of the transplant is therefore well compatible with its long-time survival, even when the lenticule has been prepared with the cryolathe and lyophilized for transportation.

Adult↗
PubMed1992

[Double-blind study of the effect of dipyridamole in patients with intermittent claudication].

32 patients (mean age 65 years, range 51-75 years) were included in this controlled, double blind study to evaluate the effect of dipyridamole in patients with intermittent claudication. Following a run-in phase of one month, 15 patients received 400 mg dipyridamole per day and 17 patients placebo. Patient characteristics (risk factors, age, clinical and apparative tests) of both groups did not differ significantly before and during the study period. Mean pain free und absolute walking distance on the treadmill (3.2 km/h, 12.5 degrees gradient) increased significantly in both groups during study period (p < 0.001 and p < 0.01). Explanations are more intensive physical activity and increasing adaptation to treadmill exercise. However, dipyridamole did not induce a significantly longer walking distance in comparison with placebo. The working hypothesis that the drug with inhibiting properties of thrombocyte function prolongs walking distance in intermittent claudication, could not be confirmed.

Aged↗
PubMed1992

Retinal pigment epithelial cells in post mortem HLA typing of corneal donors.

Corneas used for transplantation are typically obtained from donors up to 48 hr post mortem. By this time, standard HLA typing usually is impossible because of the lack of viable lymphocytes in spleen and peripheral blood. To increase the number of HLA-typed corneas, we developed a method in which the retinal pigment epithelial (RPE) cells of the donor eye are isolated, cultured in the presence of 1000 IU/ml interferon-gamma (IFN-gamma), and, after 4 d, are typed for HLA Class I and Class II antigens in the standard NIH cytotoxicity assay. Sixty five donors were typed simultaneously using peripheral blood lymphocytes and RPE. One hundred and sixteen out of 120 HLA-A antigens, 125/127 HLA-B, 106/108 HLA-C, and 92/100 HLA-DR antigens were identical using the same technique. Donor age, sex, cause of death, time of enucleation post mortem, and time of RPE preparation post mortem, as well as duration of culture period prior to stimulation with IFN-gamma did not correlate with the results of HLA typing. These data show that RPE cells can substitute for lymphocytes in post mortem HLA typing. Consequently, every donor with corneas suitable for transplantation can be prepared for matched transplantation.

Adolescent↗
PubMed1991

Blepharitis--a diagnostic and therapeutic challenge. A report on 407 consecutive cases.

Over the last few years the number of patients with chronic bilateral blepharitis has increased dramatically. From January 1985 until the end of 1989, a total of 407 patients with this diagnosis underwent ophthalmological and dermatological investigations at our out-patient clinic. Keratoconjunctivitis sicca (KCS) in conjunction with blepharitis occurred in 14.5% of the patient population who also suffered from acne rosacea. A comparison of the spectrum of microorganisms that have previously been isolated from affected sites with data obtained in the present study revealed that the range of microorganisms associated with this chronic localized inflammation has apparently shifted in recent years. The prevalence of Staphylococcus aureus, which was considerable in the pre-antibiotic era, has markedly decreased, although a distinct entity of staphylococcal blepharitis seems to remain, either alone or in combination with seborrheic blepharitis (62.8% of our patients). The clinical picture, microbiological findings and therapy for this condition are presented.

Adolescent↗