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Biomedical subjects

J Vollmar

Publications and source records attributed to J Vollmar.

At least 19 recordsLinked to original sources
PubMed1990

Morphological characterization of carotid artery stenoses by ultrasound duplex scanning.

Ulcerations and intraplaque hemorrhages are thought to play an important role in the development of neurological deficits in carotid artery stenoses. To assess the ability of duplex scanning to predict plaque morphology we compared different sonographic criteria (plaque border, plaque density, plaque structure) with the morphological findings in 169 consecutive carotid endarterectomies (144 cases with diameter reduction greater than 50%). Two percent of the sonograms were inadequate, and 20% showed poor image quality. Regular plaque borders revealed a smooth or at most minimally ulcerated surface in 92%. Grossly ulcerated stenoses, however, were only found in 27% of the irregular plaques. Moreover, the plaque border was nonvisible in 35% of all cases. Simple, fibro-atheromatous plaques were found to be echogenic in 72% and echolucency was present in 80% of the stenoses with relevant intraplaque hemorrhage. In conclusion, duplex scanning proved to be capable of detecting smooth, fibro-atheromatous stenoses with high accuracy. Ulcerations, however, cannot be predicted reliably, and intraplaque hemorrhage cannot be differentiated from atheromatous debris.

Carotid Arteries↗
PubMed1990

Ciamexone in endocrine orbitopathy. A randomized double-blind, placebo-controlled study.

The influence of ciamexone on the activity and course of endocrine orbitopathy was investigated. Fifty-one patients with active orbitopathy classes II-VI were allocated randomly to two groups: over a period of six months, 26 patients received 300 mg/day ciamexone and 25 patients received placebo tablets. In both groups, prednisolone was administered in addition in the first four weeks. Ophthalmological investigations and clinical tests as well as orbit sonography were carried out before as well as one, three and six months after the beginning of therapy. Before and after treatment, computer tomography of the orbit was performed. Symptoms and signs did not show any significant improvement one and six months after therapy. No differences between the two therapy groups were observed. Detailed examination did not reveal any preferential action of the product on individual parameters. Sonography and computer tomography showed no significant alterations of the thickness of the oculomotor muscles. Thus administration of 300 mg ciamexone once a day as compared with placebo did not show any effect on the course and activity of endocrine orbitopathy.

Adjuvants, Immunologic↗
PubMed1990

[Biochemical aspects of the evaluation of fixed drug combinations].

Various disciplines have to contribute to the general problem of the evaluation of fixed dose combination drugs, as for instance (clinical) pharmacology, biometry, scientific drug regulations and public health officials. The EC guideline 75/318/EWG and its eludications as well as the German "Arzneimittelprüfrichtlinien" of Dec. 14, 1989 (as referred to in the "Arzneimittelgesetz" of 1986) required that such issues concerning fixed dosage combination drugs must be considered and taken into account. In this framework it is the responsibility of biometry to both to guarantee the use of a valid study design to assure interpretation of the results and to quantify the reliability of pharmacological and clinical considerations. The following paper is concerned with biometrical aspects of the combination drug problem. Basic considerations from a clinical or a pharmacological point of view with respect to the question of whether fixed combination drugs are reasonable or not are not discussed. To support the use of combinations of drugs, a central argument is the improvement of the benefit risk relation compared with that of an adequate monotherapy. Beyond this the fixed combination drugs require additional arguments regarding the enhencement of the safety or the simplicity of the therapy fixing the ratio. It follows that fixed combination drugs have to be supported twice, first with respect to the combination itself, and second with respect to the fixed mixing ratio of its components. The biometrical aspects of the assessment of the gains from (fixed) drug combinations are related to the kind of benefit/risk improvement that is expected. In the first section we discuss some possible types of benefit and risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1979

[Vascular replacement with plastics (author's transl)].

The plastic substitution of the aorta and its large branches may be considered largely solved today. For this purpose preference is given to highly porous, thin-walled double velour prostheses. The search for a biocompatible plastic substitute for small caliber arteries and the large veins of the body (portal vein, vena cava, iliac veins) is proceeding in two directions at the present time: on the one hand towards optimized bioprostheses and on the other hand towards plastics which apply the principle of microporosity or impermeability with the creation of antithrombogenic inner surfaces. In this respect expanded polytetrafluoroethylene and coating with carbon are very promising.

Biocompatible Materials↗
PubMed1979

[The effect of metipranolol on the carbohydrate metabolism in diabetics treated with glibenclamide (author's transl)].

Previous investigations on the effect of beta-receptor blockers on the carbohydrate metabolism of diabetics have reported varying effects, the most frequent being hypoglycaemic symptoms which were interpreted as potentiating effects caused by interference with the antidiabetic agents. For this reason, the effect of the beta-receptor blocker metipranolol on the carbohydrate metabolism of diabetics treated with glibenclamide was investigated in a double blind cross-over study comparing metipranolol with placebo. The results do not show any significant difference between the placebo and the metipranolol with respect to the blood or urinary sugar values or the plasma insulin levels. Whether or not this is a substance-specific property needs to be clarified by further comparative investigations using other beta-receptor blockers. There were similarly no significant differences in the most important parameters of hepatic and renal function.

Adult↗
PubMed1979

[Reconstructive surgery of the internal carotid artery (author's transl)].

Between 1970 and 1978 we performed 403 endarterectomies of the internal carotid artery on 330 patients. Operative morbidity (and mortality) depended on the severity of the ischemic cerebral damage at the time of the operation: stage I (137 operations):1.5% (0.7%); stage II (134 operations): 2.2% (3.7%); stage III (29 operations): 3.4% (10.3%); stage IV (103 operations): 3.9% (7.8%). According to the life-table analysis (average follow-up: 40 months) the rate of cured or improved patients amounts to 94% (operated at stage I), 85% (stage II), 84% (stage III) and 70% (stage IV).

Arterial Occlusive Diseases↗
PubMed1979

[Expanded PTFE (polytetrafluoroethylene) vascular prostheses--a new path of arterial and venous replacement].

Based on existing experimental and clinical observations the expanded PTFE graft shows convincing advantages in some indication fields (e.g., vascular access for hemodialysis, venous reconstruction) compared with conventional porous prostheses and biografts. On the other hand, we have to realize that expanded PTFE is not yet qualified to be the optimal substitute for small arteries. In spite of encouraging preliminary results, the use of this new type of vascular prosthesis still requires critical evaluation to avoid unpredictable failure due to uncritical surgical optimism (caution: Sparks disaster!). Further improvements may be expected from a better anchorage in the surrounding tissue (e.g., external velour), and from an increase of antithrombogenity of the inner surface.

Arteries↗
PubMed1979

[Surgery in combined aorto-iliac and femoro-popliteal occlusive lesions (author's transl)].

In combined chronic occlusive lesions at the aorto-iliac and femoro-popliteal level the partial repair of the central vessel in combination with profundaplasty and lumbar sympathectomy ("triad procedure") represents a simpler and shorter procedure than the previously preferred total correction of both segments. In a retrospective study of 403 limbs (stage II-IV) the triad procedure shows a cumulative patency (life table analysis) of 77% vs. 39% in total repair. The amputation rate in triad procedure--for stage III/IV--was 8% vs. 36% and the frequency of reoperation 7% vs. 23% in total repair. Prerequisites for this type of repair are an optimal technique and a correct selection of patients presenting patient "receiving segment" of the popliteal artery and a sufficient run-off below the knee.

Aortic Diseases↗
PubMed1979

Venous trauma.

Explore the source record for details and available documents.

Humans↗
PubMed1979

Dysplasia of the lymphatics with lymphoedema, generalized lymphangiectasis, chylothorax and "pseudo-storage-disease".

A patient showing an unusual association of various abnormalities of the lymphatic vascular system is reported. These abnormalities became first evident in early childhood and consisted of lymphoedema of the left leg, lymphangiectasis in various organs and occlusion of the thoracic duct at its entrance into the venous angle. Chylous effusions and subcutaneous chyloedema appeared in adolescence. Diagnostic biopsies of spleen, liver and bone-marrow revealed the presence of multiple foamcells, suggesting the diagnoses of lipid storage disease. The patient died from severe honeycomb-lungs at the age of 20. This case cannot be attributed to one of the wellknown disease entities of the lymphatic system. The "pseudo"-storage disease is regarded as secondary to the backflow of chylus into the tissues.

Adolescent↗
PubMed1978

[Results of using the reflomat for determining glucose concentration, and the influence of glycolysis inhibitors on Reflotest-glucose (author's transl)].

There was a close correlation between the hexokinase-glucose-6-phosphate-dehydrogenase method and reflomat/Reflotest-glucose on capillary blood samples without addition of glycolysis-inhibitors. The relative deviations were less than 10% over the entire range. In systematic studies set up to determine the influence of sodium fluoride and sodium monoiodo-acetate on the reflomat/Reflotest glucose system it was demonstrated that sodium monoiodo-acetate can be used when determining glucose with reflomat/Reflotest glucose, while sodium fluoride produced false values with this system.

Blood Glucose↗
PubMed1978

[Lipid-lowering effect of bezafibrate in patients with diabetes mellitus and hyperlipidaemia (author's transl)].

600 mg of bezafibrate daily were administered to 13 well controlled diabetics with hyperlipidaemia for 12 weeks. Placebo was given before and after the treatment period. Compared with pretreatment placebo, bezafibrate reduced triglycerides (between 37 and 47%) and cholesterol (between 12 and 19%) significantly. Blood glucose levels during treatment were significantly lower at 8 and 12 weeks compared with post-treatment placebo values. Urinary glucose excretion did not change. Hypoglycaemia was not observed. No change in antidiabetic medication was necessary. Bezafibrate was well tolerated. It lowered blood lipids effectively in diabetics with hyperlipidaemia. No additional precautions have to be taken to control carbohydrate metabolism during bezafibrate treatment.

Blood Glucose↗
PubMed1978

[Surgery of neck vessels (author's transl)].

The progress in vascular surgery offers to the otolaryngologist a remarkable increase of his surgical activities. This is especially true in the field of tumor surgery in the region of the carotid arteries and the jugular vein (e.g. removement of carotid body-tumor, lymphnode deposits by neckdissection etc.). Both the ligature of the internal as the common carotid arteries should be--when ever possible--avoided. The method of choice is an arterial reconstruction (by direct vascular suture or an autogenous venous graft respectively a Dacronprosthesis). In the presence of wound infection or damaged soft tissue by radiation any vascular repair is contraindicated except of an extra-anatomic bypass-procedure. Every otolaryngologist engaged with great neck surgery should be familiar with the basic principles of vascular surgery and should keep a set of vascular instruments available. Some neck interventions, dealing with the great vessels, are best performed in teamwork of laryngologist and vascular surgeon.

Adolescent↗
PubMed1978

[Surgery of congenital angiodysplasia (author's transl)].

Diagnostically and therapeutically, three types of angiodysplasias interfere with venous surgery: 1. Congenital arteriovenous fistulas (Type F.P. Weber: secondary varicosis with local gigantism)--surgical reduction of the shunt-volume is usually indicated. 2. Type Klippel-Trenaunay: Surgery for varicose veins is dangerous due to the frequent hypo- or aplasia of the deep venous system. 3. Venous hemangiomatosis (Type Servelle-Martorell or Kasabach-Merritt): Any surgical intervention is contraindicated (only external compressive therapy).

Angiomatosis↗