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Biomedical subjects

B I Wenzel-Hora

Publications and source records attributed to B I Wenzel-Hora.

At least 19 recordsLinked to original sources
PubMed1989

Vacuum injection--a new indirect fixing method for the demonstration of initial lymphatics in biopsy specimens of human organs.

With the indirect vacuum injection method (IVIM) at a negative pressure of 30 kPa, it is possible to demonstrate the initial lymphatics (IL) by scanning electron microscopy even in biopsy specimens of various organs (minimum size 0.5 X 0.5 cm2). IL can also be dilated and fixed using the indirect perfusor injection method (IPIM), but only in larger specimens (minimum size 2.0 X 2.0 cm2). Only dilated IL can be examined by scanning electron microscopy, and only the IL of the ampulla of the Fallopian tube can be reliably dilated during immersion fixation. The quality of fixation on use of the vacuum technique conforms to the standard achieved with other methods. No one has yet succeeded in demonstrating the IL in biopsy specimens smaller than mentioned above using any of the methods described.

Adult↗
PubMed1989

Urography with monomeric and dimeric nonionic contrast media: comparative, randomized, double-blind study of iotrolan 280 and iopromide 300.

In a double-blind comparative study between the nonionic, dimeric iotrolan and the nonionic, monomeric iopromide the urographic image quality in the dose 300 mg I/kg body weight is better after iopromide up to 20 minutes after the injection. This result appears to be in contradiction to the results of the animal experimental studies. Possible reasons are discussed.

Clinical Trials as Topic↗
PubMed1989

Tolerance of iotrolan 190 and cerebrospinal fluid-diluted iotrolan 300 at the same iodine concentration in lumbar myelography.

Iotrolan, the radiologically effective ingredient of the contrast medium Isovist, has so little osmotic activity that only solutions of about 300 mg I/ml are isotonic to cerebrospinal fluid (CSF). The osmolality of the contrast medium at lower iodine concentrations has to be increased through additives. Theoretically, iotrolan 300 diluted with CSF is the most physiologic. Therefore, the commercial preparation iotrolan 190 (adaptation of the osmolality through the addition of saline and sodium bicarbonate) was tested in a randomized, single-blind study against a diluted contrast medium solution, iotrolan 190 (produced from iotrolan 300). The dilution was performed with the patient's own CSF. The test was carried out in lumbar myelography in two groups of 50 patients each. There were neither statistical nor tendency differences between the two preparations in either the opacification or the tolerance. Therefore, there is no suggestion that a contrast medium solution prepared with the patient's own CSF is better tolerated.

Adolescent↗
PubMed1989

Iotrolan versus iopamidol: a controlled, multicenter, double-blind study of lumbar and direct cervical myelography.

Iotrolan is a new nonionic, dimeric contrast medium that is distinguished by its special physicochemical and low chemotoxic properties. It displays near isotonicity with blood and cerebrospinal fluid in all clinically used concentrations (190, 240, and 300 mg I/ml). The controlled, double-blind study of iotrolan versus iopamidol presented here shows that iotrolan is significantly superior to the monomeric contrast medium in lumbar and direct cervical myelography. Use of the dimeric contrast medium reduced not only the incidence of side effects, but also their severity and duration. The chemotoxicity of contrast media commonly used was significantly less with iotrolan in all neuroradiologic diagnostic studies of the spine. The diagnostic quality of lumbar and direct cervical myelography with iotrolan was high. In this randomized, double-blind study versus iopamidol, iotrolan proved to be the safer and better myelographic agent for contrast studies of the spinal canal.

Adolescent↗
PubMed1989

Iotrolan, a nonionic dimeric contrast medium in myelography.

As part of a clinical Phase III study of the nonionic, dimeric contrast medium iotrolan, differences in opacification, tolerance, and effects on the electroencephalogram after myelography were examined in a double-blind comparison with iohexol. Two groups of 25 patients each received either 10 ml iotrolan 240 mg I/ml or 10 ml iohexol 240 mg I/ml for lumbar myelography, and two groups of 50 patients each received either 10 ml iotrolan 300 mg I/ml or 10 ml iohexol 300 mg I/ml for lumbar, thoracic or cervical myelography. The overall assessment of the opacification in the subarachnoid space, which was moderate in only one case of each group and otherwise good, showed no differences between the preparations. The tolerance of both concentrations of iotrolan proved to be significantly better than those of iohexol: at a significance level in the chi-square test of p less than 0.001 in a simple size of 25 patients per preparation with 240 mg I/ml and at a significance level of p +/- 0.05 in a sample size of 50 patients per preparation with 300 mg I/ml.

Adult↗
PubMed1989

Indirect lymphography with iotrolan.

Iotrolan was used in concentrations of 240 and 300 mg I/ml for indirect lymphography in a total of 70 patients, and permitted a diagnostic evaluation of the peripheral lymphatics in all cases. The contrast quality was found to correlate with the concentration used. The concentration of 300 mg I/ml Iotrolan was judged to provide the better contrast density and definition. Side effects were limited to transient local erythema and pain during the infusion in one patient and a protracted reaction resembling serum sickness in another patient (Iotrolan 240 mg I/ml). Because of its excellent tolerance, Iotrolan is particularly suitable after subepidermal infusion for indirect lymphography, during which the local lymph drainage of cutaneous regions of interest can be evaluated.

Clinical Trials as Topic↗
PubMed1989

Gastrointestinal diagnosis with iotrolan: experience in pediatric radiology.

The use of low-osmolar, nonionic, monomeric contrast media has made gastrointestinal diagnosis with water-soluble contrast media less hazardous with a greater diagnostic yield. Since, however, even this group of compounds is hypertonic in comparison with blood, water is still drawn from the body into the bowel, resulting in water and electrolyte shifts and distal dilution of the contrast material with deterioration of the image quality. The use of iotrolan, which is isotonic in comparison with blood, therefore, appears to offer advantages for selected groups of patients. The superiority of the contrast medium iotrolan over iohexol was demonstrated in a double-blind study. A further 72 examinations in an open-ended study confirmed this result.

Child, Preschool↗
PubMed1989

Organ-specific and general tolerance of iotrolan 280 after intravenous administration: phase I study in healthy volunteers.

Iotrolan 280, the first water-soluble, nonionic, blood-isotonic, dimeric contrast medium, was administered intravenously to 12 healthy male volunteers. In a Phase I study with an intraindividual design in comparison with placebo, four doses between 0.15 and a maximum of 0.9 g I/kg body weight were administered in accordance with the principle of dose titration. The highest volume administered was 270.6 ml. The injection rate was 10 ml/min. The observation period was 5 days, with the exception of thyroid parameters (14 days). Iotrolan displayed good general and local tolerance. The typical side effects known from x-ray contrast media either did not occur or were minor after administration of iotrolan. No allergy-like reactions and no effects on hemodynamic parameters were observed. Although one observation is under discussion no effects of iotrolan on impulse generation and propagation in the myocardium could be confirmed. The blood and laboratory and chemical parameters analyzed showed no differences in comparison with placebo. In the treatment group with the highest dose (= 0.9 g I/kg body weight) there was one subject who showed a transient increase of the urinary glucose concentration and one case of a slight transient increase of the serum chloride concentration. No such side effects were seen in the subjects of the treatment groups with lower doses. All renal functions tests were normal. In this study iotrolan showed excellent tolerance after intravenous injection up to 0.9 g I/kg body weight.

Adult↗
PubMed1989

Initial experience with a nonionic, dimeric contrast medium (iotrolan) in direct and indirect arteriography: a randomized, intraindividual double-blind study in 60 patients.

The new isotonic contrast medium iotrolan has been compared with iopromide in aortofemoral arteriography, selective femoral arteriography, and intravenous digital substraction angiography (DSA). In each case a crossover study design has been chosen with special emphasis on patient comfort. Despite problems in the interpretation of results due to a "hangover" effect in selective peripheral arteriography, it may be concluded: (1) Iotrolan causes significantly less discomfort, such as the feeling of heat and most likely also pain, than iopromide. However, one patient reported slight pain after the injection of iotrolan even when no previous injection of iopromide had been performed; (2) in intravenous DSA contrast appeared 1 to 2 seconds later in the region of interest after the injection of iotrolan compared with iopromide, probably due to the slightly higher viscosity of the former agent; (3) otherwise, no differences between the two agents have been observed. No cardiovascular or other kind of side effects occurred with the exception of one slight allergy-like reaction in 60 patients.

Angiography↗
PubMed1988

Clinical use of indirect lymphography in different forms of leg edema.

Indirect lymphography by subepidermal infusion of newly developed nonionic, dimeric contrast media (e.g., Iotrolan) opacifies peripheral lymphatics of the skin. Using this method we examined 159 patients with primary and secondary lymphedema, chronic venous insufficiency, and lipedema and compared the findings to normal individuals. A variety of characteristic patterns were uncovered. The technique causes little patient discomfort and takes on the average only 30 minutes.

Contrast Media↗
PubMed1987

Influence of the spread and period of retention of Iotrolan in the subarachnoid space on the side effects rate in myelography.

Fifty patients underwent myelography with the newly developed CSF-isotonic, dimeric, non-ionic contrast medium Iotrolan. Repeat spinal and cranial computerised tomographic studies with measurement of the attenuation values were conducted to demonstrate the administered contrast medium in the spinal canal and intracranial subarachnoid space. The patients were examined neurologically, observed clinically and asked about concomitant symptoms. The period of retention and the spread of the contrast medium in the subarachnoid space was not found to have any influence on the side effects rate. In particular, no association was confirmed between intracranially demonstrable contrast medium and the occurrence of side effects.

Adult↗
PubMed1987

Scanning electron microscopy of the initial lymphatics of the skin after use of the indirect application technique with glutaraldehyde and MERCOX as compared to clinical findings.

Certain phenomena in the region of the initial lymphatics during clinical examination (indirect lymphography and microlymphography)--namely build-up and course and filling and diffusion--have still to be elucidated. The glutaraldehyde and MERCOX methods were used to simulate indirect application conditions in clinical procedures in skin specimens (human and pig) which were then examined by scanning electron microscopy. The results presented include novel findings on the microtopography of these lymph vessels and the typology of filling refluxes which are of importance when indirect imaging techniques are employed. Various speeds of application were used and the function of the opening apparatus with previously undescribed structures (endothelial bridges and connective tissue trabeculae) was taken into consideration. Recommendations aimed at standardizing the nomenclature of parietal structures and sections of the lymphatics have been incorporated in the report.

Aldehydes↗
PubMed1986

Iotrolan. The first dimeric non-ionic contrast medium for the subarachnoid space.

Iotrolan was administered to 1400 in-patients and out-patients by intrathecal injection within the framework of the clinical investigation. It was used for studies of the lumbar, thoracic, cervical and intracranial areas. It was compared with metrizamide, iopamidol and iohexol in concentrations of 190, 240 and 300 mg I/ml in controlled double-blind trials. The minimum observation periods were four days including the investigation of clinicochemical, cardiovascular and electroencephalographic parameters, and CT. The incidence and severity of all side effects after Iotrolan were much lower than those after the non-ionic monomers. No epileptogenic incidents or symptoms of a psychosyndrome were observed in any of the cases--not even after prolonged retention in the intracranial fluid spaces.

Contrast Media↗
PubMed1985

[1st report on indirect lymphography using iotasul in the head and neck region].

The early results in 29 patients with tumours in the head and neck are described, on whom indirect lymphography with the water-soluble contrast medium Iotasul had been carried out (experimental contrast medium, Schering AG). After careful sub-epidermal injection of about 12 ml contrast, either lateral to the eye or in the region of the chin, lymph vessels were seen in 25 patients and lymph nodes in 20. These were demonstrated by conventional radiography or by xero-radiography. There were no local or generalised reactions.

Contrast Media↗