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Biomedical subjects

A Mostbeck

Publications and source records attributed to A Mostbeck.

At least 37 records · Page 2Linked to original sources
PubMed1990

Urine excretion of inhaled technetium-99m-DTPA: an alternative method to assess lung epithelial transport.

Technetium-99m DTPA clearance (99mTc-DTPA) clearance measured by a gamma camera or a scintillation probe not only reflects epithelial transport, but is also influenced by an unknown amount of mucociliary clearance depending on particle size and aerosol deposition. This is confirmed by factor analysis of dynamic inhalation studies. Assessment of epithelial absorption by urinary excretion of inhaled 99mTc-DTPA is largely independent of aerosol lung deposition. Twenty-four-hour excretion reflects the amount of aerosol cleared by absorption, while two-hour excretion is a quantitative measure of the aerosol absorption rate from the epithelium into blood. Urinary 99mTc-DTPA excretion of two aerosols with different particle size correlated significantly (p less than 0.001) with analysis of lung clearance curves. A very similar regression in the form of a cumulative exponential function was found with both aerosols. Two-hour urine values of nonsmokers differed significantly from those of smokers or patients with active interstitial or infectious lung disease. This alternative procedure is suited as a bedside test and holds promise for patient monitoring and follow-up.

Administration, Inhalation↗
PubMed1988

[Measurements of radiocesium incorporation in 250 deceased patients who died within a year following Chernobyl].

Two months after the nuclear accident of Chernobyl, postmortem measurement of radiocaesium (137 Cs and 134 Cs) were started in different organs to study incorporation, organ distribution, and kinetics. 250 corpses were examined between July 1986 to August 1987 in the Department of pathology, St. Pölten. Highest concentrations were found in skeletal muscles, with a median value of 2.3 pCi/g wet weight (80-90% of the total incorporated dose), followed by liver, lung, spleen, kidneys, thyroid gland, heart, blood and brain, with values between 0.8 and 1.3 pCi/g. No caesium was detectable in fatty tissue. During the observation period an increase in caesium concentration was observed in almost all organs. The concentration almost doubled within 10 months in skeletal muscles. Only the lung demonstrated a decrease in the radiocaesium concentration within the first months, which can be explained only by inhalation of radiocaesium. A statistically significantly higher caesium concentration in most organs was found in females as compared with males. A possible explanation is the known lower urinary caesium concentration in women. Statistically significant correlations were found between caesium concentration and nutritional status, presence of malignancy, and the most recent intravital serum creatinine value.

Accidents↗
PubMed1987

Incidence and clinical feature of pulmonary embolism in patients with deep vein thrombosis: a prospective study.

In 169 patients with suspected deep vein thrombosis (DVT), the incidence and clinical feature of pulmonary embolism (PE) was prospectively studied by means of noninvasive thrombosis tests (uptake tests, radionuclide venography) and combined ventilation (133Xe, 81mKr) and perfusion (99mTc microspheres) lung scanning. DVT was detected in 62% of patients (105/169). The incidence of PE in patients with confirmed DVT was 57% (60/105), a figure which is in excellent agreement with data from autopsy studies. Concerning the thrombotic source of emboli, the incidence of PE was 46% in patients with DVT confined to the calf but increased to 67% if the thigh, and to 77% if the pelvic veins were involved as well. Fifty-nine percent of PE were clinically silent, 19% had "minor signs", and 22% "major signs". The size of the perfusion defects correlated significantly with clinical symptoms. Only 23% of clinically symptomatic patients had a pathological chest X-ray. Incidence of both DVT and PE increased with advancing age, but in old patients the incidence of PE rose disproportionately.

Adult↗
PubMed1987

[Single-photon emission tomography (SPECT) using 123I-amphetamine in cerebral ischemic circulatory disorders].

The uptake of 123I-amphetamine (IMP) in brain mainly corresponds to regional perfusion. Distribution of IMP can be visualized in tomographic slices by single-photon emission computed tomography (SPECT). For better evaluation and comparison in follow-up studies, right/left ratios were computed and an asymmetry index calculated. The most sensitive asymmetry index was achieved by 120 average circumferential profiles. In 52 patients with stroke and 16 controls the respective sensitivities of IMP-SPECT, computed tomography (CT), static and dynamic brain scanning and angiography were evaluated. In patients with TIA and PRIND the IMP-SPECT had the highest sensitivity of all non-invasive methods. In patients with completed stroke, the sensitivity of IMP-SPECT was comparable with that of CT (90 vs. 93%). There was a significant correlation between the IMP asymmetry index and the clinical and social score (p less than 0.001). The IMP asymmetry index was significantly correlated to the size of the CT lesion (p less than 0.001). In most patients, the size of the IMP lesion was larger than that of CT. In a prospective study, 28 patients with completed stroke were examined. 14 patients underwent surgical treatment (6 endarterectomies, 5 EIA, 3 combined operations), 14 patients had medical treatment only. Both groups were reexamined after 10 and 6.5 months, respectively. In both groups, neither the IMP asymmetry index nor the size of the CT lesion were changed, but the clinical and social scores improved (p less than 0.01). The outcome in both groups was the same. A positive effect of surgery could not be demonstrated.

Amphetamines↗
PubMed1985

Dry aerosol of monodisperse millimicrospheres for ventilation imaging: production, delivery system, and clinical results in comparison with 81m-krypton and 127-xenon.

The production of monodisperse human albumin millimicrospheres (diameter less than 1 micron) and labeling with 99mTc is described. A system constructed to nebulize and deliver a dry aerosol yielded a lung delivery efficiency of approximately 25%. In 48 patients without and with varying degrees of chronic obstructive lung disease, quantitative comparison with 81mKr (penetration index, regional distribution of activity in the lungs) demonstrated similar penetration of the particles to the lung periphery (r = 0.89 and r = 0.94, respectively). Qualitative comparison with 81mKr or 127Xe showed complete or a high degree of diagnostic agreement in all but one patient. Semiquantitative scoring of hot spots as a substrate of local turbulent airflow showed a close inverse correlation (r = -0.82) with the forced expiratory volume in 1 s (FEV 1.0%), thus providing additional information about the severity of the airway obstruction. In 24 patients with suspected pulmonary embolism, complete agreement between aerosol and 81mKr images was found in all patients studied. For same-day ventilation/perfusion studies, labeling of the millimicrospheres with 111In yielded images of comparable quality to those obtained with the 99mTc-labeled aerosol.

Aerosols↗
PubMed1984

[New aspects in the diagnosis of venous and lymphatic diseases of the legs].

A survey on new methods for the detection of deep vein thromboses and for the investigation of lymphedemas of the lower extremities is given. Doppler-ultrasound, plethysmography and tele-thermography are valuable screening procedures for the detection of a deep vein thrombosis. Nuclear medical methods such as 131 J fibrinogen or 99-m-TC-plasmin-uptake test as well as isotopic phlebography are additional non-invasive procedures. For the routine diagnosis of lymphedema, isotopic lymphography can be recommended. Recently described methods such as quantitative isotopic lymphography and indirect lymphography with the new contrast medium Iotasul will probably enhance our present knowledge concerning pathophysiology and therapeutical effects in lymphedemas.

Adolescent↗
PubMed1984

Intravenous streptokinase therapy in acute myocardial infarction: assessment of therapy effects by quantitative 201Tl myocardial imaging (including SPECT) and radionuclide ventriculography.

To evaluate a potential beneficial effect of systemic streptokinase therapy in acute myocardial infarction, 36 patients treated with streptokinase intravenously were assessed by radionuclide ventriculography and quantitative 201Tl myocardial imaging (including SPECT) in comparison with 18 conventionally treated patients. Patients after thrombolysis had significantly higher EF, PFR, and PER as well as fewer wall motion abnormalities compared with controls. These differences were also observed in the subset of patients with anterior wall infarction (AMI), but not in patients with inferior wall infarction (IMI). Quantitative 201Tl imaging demonstrated significantly smaller percent myocardial defects and fewer pathological stress segments in patients with thrombolysis compared with controls. The same differences were also found in both AMI and IMI patients. Our data suggest a favorable effect of intravenous streptokinase on recovery of left ventricular function and myocardial salvage. Radionuclide ventriculography and quantitative 201Tl myocardial imaging seem to be reliable tools for objective assessment of therapy effects.

Adult↗
PubMed1984

[Functional and morphologic studies on the reinnervation of the replanted rabbit external ear].

Disturbances observed int he thermoregulation of replanted extremities were the stimulus for this experimental study. We chose the auricular conchae of rabbits as an experimental model, as these show--as do the fingers--innervation with the sympathic nervous system and fulfil thermoregulatoric functions. Twenty-five of thirty auricular conchae of rabbits took completely after amputation and replantation. Blood flow measurements with 133 Xenon, thermographic and histologic examinations were performed. Thermography showed dysfunction with temperature provocation even one year after replantation. Histological examinations revealed partly deficient reinnervation in vessels and also in cutaneous appendages.

Animals↗
PubMed1983

[Diagnosis in sarcoidosis. Sensitivity and specificity of 67-gallium scintigraphy, serum angiotensin converting enzyme levels, thoracic radiography and blood lymphocyte subpopulations].

In a prospective study in 73 patients (48 female, 25 male) with histologically proven sarcoidosis we examined the sensitivity and specificity of Gallium 67 scanning, S-ACE, chest X-ray and blood T-lymphocyte assays for assessment of activity in sarcoidosis. We found a positive correlation between 67Ga score and S-ACE (r = 0.54, p less than 0.001). S-ACE levels and 67Ga score were significantly higher (p less than 0.001) in active sarcoidosis compared to inactive sarcoidosis. However, patients characterized by bihilar active sarcoidosis proved to have higher mean S-ACE levels (p less than 0.025) and a higher 67Ga score (n. s.) compared to patients with other presentations of active sarcoidosis. 67Ga scanning had the highest sensitivity of all parameters (92%) to detect active sarcoidosis, followed by chest X-ray (79%) and S-ACE (70%). Blood T-lymphocyte assays without comparison to lavaged lung T-lymphocytes failed to give reliable results. In patients with inactive sarcoidosis S-ACE showed a higher specificity (85%) compared to 67 Ga scanning (77%). Among follow up assessments in 26 patients with recurrent sarcoidosis 67Ga scanning proved to be the most reliable means for all stages of sarcoidosis whereas in patients with interstitial pulmonary lesions chest X-ray as well as S-ACE sometimes failed to assess activity. For the clinical management of patients with pulmonary sarcoidosis we suggest the combined use of chest X-ray and S-ACE. In case of discrepant results, as well as interstitial pulmonary involvement or for difficult therapeutic decisions the use of 67Ga scanning or bronchoalveolar lavage should be considered.

Adolescent↗