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Biomedical subjects

J Staubesand

Publications and source records attributed to J Staubesand.

At least 19 recordsLinked to original sources
PubMed1996

[Chronic venous insufficiency].

In severe chronic venous insufficiency (CVI) the fascia cruris is increasingly involved in the pathological process. The resulting loss of compliance as a consequence of altered fascia texture leads to increased pressure in the compartments of the lower extremity, followed by reduced circulation. Arteries and nerves, which penetrate the fascia along with insufficient perforating veins, are damaged through the increased pressure and are therefore functionally impaired. Accordingly many pathological changes in the crural ulcer have their anatomical substrate here. The microcirculation is distributed by either primary varicosis with secondary insufficiency of the deep veins or by primary insufficiency of the deep venous system as seen in a post-thrombotic syndrome. Subsequent therapy should be based on this knowledge and therefore consists of medication and basic physical therapy along with dissection of the perforating veins-fasciotomy and fasciectomy combined with plastic surgery. All of the therapeutic measures have to take the stage of the CVI into consideration. In order to eliminate the insufficient perforating veins and to perform fasciotomy the endoscopic approach is considered the state of the art. In extreme cases, only fasciectomy combined with plastic surgery can lead to durable healing.

Combined Modality Therapy↗
PubMed1995

Use of duplex sonography to investigate the effect of active and passive movement at the ankle joint for promoting venous return.

Among the joint and muscle pumps that are hemodynamically active and, in particular, bring about venous return in the lower limb, the so-called ankle pump is of paramount importance. The basic anatomical relationship of the talocrural joint to the venous network around the ankle is reviewed. Duplex sonographic measurement of the rate of blood flow in the great saphenous vein at the saphenous opening, at rest and during active and passive movements at the ankle joint, shows that such movements have an important effect on the rate of flow through the adjacent veins. Passive movement of the foot relative to the leg was brought about by a newly developed apparatus that can be either pneumatically or electrically operated. The action of the ankle pump against venous stasis, the arthrogenic congestive syndrome, and chronic venous insufficiency has demonstrated the prophylactic importance of this physiological mechanism. It can, when necessary, be replaced by an appropriately designed apparatus.

Adult↗
PubMed1995

Topography of the perforating veins on the medial side of the leg (Cockett's veins).

A macroscopic anatomical investigation was carried out on 67 embalmed dissecting-room legs in order to determine the position, course, and origin of so-called Cockett's perforating veins. This information was considered to be of particular importance because of the frequency with which varicoses in this region are treated with sclerosing agents and the serious adverse effects that can follow a misplaced injection. In view of the almost universal credence given to the accuracy of Cockett's original description (Cockett FP, 1955, Br. J. Surg. 43:260-278), and the general acceptance of the constancy of "Cockett's veins," it was felt to be of importance to see to what extent we could confirm this description. It was found that the origins of these vessels and the places at which they penetrate the deep fascia are not constant, and that--in our series--only 7.3% of the veins belonging to these groups occupy the positions that are repeatedly cited in the literature as the most common. The clinical importance of any discrepancy between expectation and reality can hardly be exaggerated.

Aged↗
PubMed1995

The official nomenclature of the superficial veins of the lower limb: a case for revision.

Attention is called to the discrepancy which exists between the official terminology of the Nomina Anatomica (PNA) as it relates to the superficial venous system of the lower limb, and anatomical reality. Suggestions are also put forward as to how the PNA could be altered to accord better with the systematic classification and topography of these vessels, and more usefully serve the needs of clinicians.

Femoral Vein↗
PubMed1993

Intracavernous application of SIN-I in rabbit and man: functional and toxicological results.

The mode of action of the active metabolite SIN-I of the vasodilator prodrug molsidomine was studied in vitro and in vivo in corpus cavernosum of rabbit and man. SIN-I produces a dose-dependent relaxation of isolated human cavernous smooth muscle strips. In the rabbit, the intracavernous application of SIN-I increased the intracavernous pressure to a full erection (approximately 100 cm H2O). This response was highly reproductible. SIN-I was also injected intracavernously 6 times in five rabbits over 2 weeks; no inflammatory or fibrotic reactions were found on histology. SIN-I may be a reliable drug for the treatment of impotence without side-effects.

Animals↗
PubMed1990

[Calcium determination, enzyme biochemical and electron microscopy studies of saphenous veins in patients with coronary sclerosis or varicose veins].

In patients undergoing aortic-coronary bypass operations, essentially similar ultrastructural changes are found both in the fragments removed from the coronary arteries and in veins from the saphenous system that are about to be used as autografts. The most important changes involve the intima and media, and include an increase in the number of 'm' smooth muscle cells and degenerating or dying cells, together with enlargement of the total intercellular space of the media and an increase in the proportion of dysplastic collagen fibrils found there. Furthermore, both the venous grafts and the varicose veins of heavy smokers who inhale show an increase in the calcium content that is independent of age. On the other hand, varicose veins which have been stripped show no alteration in either beta-NAG or alkaline phosphatase activity as a result of smoking; although, in parts of the saphenous veins mobilised for transplantation, an increase in the activity of both enzymes is found which is dependent upon the number of cigarettes daily consumed by the patient.

Acetylglucosaminidase↗
PubMed1990

Intracavernous drug delivery system: an alternative to intracavernous injection in the treatment of impotence?

In 6 monkeys, the feasibility of chronic intracavernous drug application via a permanent intracavernous catheter was examined. In 4 monkeys, a combination of papaverine (15 mg/ml) and phentolamine (0.5 mg/ml) was injected via the drug delivery system; in 2 monkeys each, 30 or 100 injections were done. As a control, saline was injected in 2 monkeys. The dose of the papaverine-phentolamine mixture to induce full erection had to be increased by a mean of 240%, comparing the 1st to the 30th injection. The dose then remained stable. After 100 injections, penile histology showed a thin fibrotic layer around the implantation site of the catheter. Beside slight smooth muscle hypertrophy in the papaverine-phentolamine group, there were no abnormal findings in the proximal and medical part of the cavernous bodies. The distal part of the cavernous bodies showed extensive fibrosis due to mechanical irritation by the tip of the intracavernous catheter. Given appropriate selection and indication, implantation of an intracavernous drug delivery system may be an alternative to chronic intracavernous injection in the treatment of impotence.

Animals↗
PubMed1989

On the haemodynamics of arteriovenous fistulas in the rat.

Direct and indirect arteriovenous fistulas were applied to the cervical vessels of 19 rats in order to study the haemodynamic parameters of angioma-like, rapid blood flow in small vessels. Flow was measured electromagnetically and intraoperatively using the Doppler sonography, and both methods were compared. Resultant alterations in vessel walls were examined under the electron microscope. Following fistula application, the flow rates increased by a factor of ten. At the same time, the flow pattern profile and stream resistance also changed. At present, the Doppler sonography device employed here is the only one commercially available, yet it could not detect rapid flow rates (greater than 85 cm/sec). The abnormal haemodynamic strain on the venous walls led to morphologically and angiographically detectable alterations.

Animals↗
PubMed1988

Immunocytochemical demonstration of lysosomal matrix vesicles in the arterial wall of the rat.

Following necrobiosis of the smooth muscle cells (SMC) of the vessel wall, lysosomes are still able to live for a time in the extracellular space. Here they are known as lysosomal matrix vesicles (MV). Their lysosomal origin can be confirmed by the immunocytochemical demonstration of beta-N-acetylglucosaminidase (beta-NAG) in extracellular MV. A positive reaction to the enzyme-cytochemical test for acid phosphatase establishes that these lysosomal MV are enzymatically active. The role of the lysosomal MV in the pathogenesis of vascular diseases is seen in an uncontrolled, locally limited destruction and alteration of the intercellular substance.

Acetylglucosaminidase↗
PubMed1988

Vascular thermocoagulation-perivascular nerve lesions. An ultrastructural report on the choice between monopolar and bipolar electrocoagulation.

High-frequency coagulation is used with advantage for a number of purposes, including the production of haemostasis during surgery. The morphological changes which thermocoagulation produces in or near the wall of an artery remain, however, largely unknown; and systematic research in the subject is long overdue. As might be expected from clinical experience, the local effects of monopolar thermocoagulation are much more severe and far-reaching than those caused by the bipolar method. For these reasons the bipolar coagulation technique is to be preferred wherever possible.

Animals↗
PubMed1988

Application of a laser-induced endothelial injury model in the screening of antithrombotic drugs.

A method of inducing microthrombi in small rat mesenteric vessels (approximately 20 to 30 micron) has been developed to study platelet reactions and to investigate antithrombotic drugs. For microscopy, a high-power water immersion system, based on a Leitz Orthoplan microscope, was used. In sodium pentabarbital anesthetized male Wistar rats and in fawn-hooded bleeder rats vascular lesions were produced with a Coherent CR-2 ion laser (argon laser). The laser induced vascular damage, without intravascular heat precipitates, which led to the adhesion, transformation, and aggregation of platelets at the damaged vessel wall. Fibrin threads were rarely formed in these early platelet thrombi. Thrombus formation was estimated by the number of laser injuries required to induce a defined thrombus. The first steps of thrombus formation, in particular the adhesion and reversible aggregation, were significantly reduced in this model in fawn-hooded bleeder rats. A number of different drugs modified thrombus formation in this model, for instance, ASA, defibrotide, unfractionated or low molecular heparins. It is unlikely that a single mechanism is responsible for the observed antithrombotic effects of each of these drugs. The inhibition of platelet adhesion by changes of membrane glycoproteins, interference with the early activation of plasma proteins, effects on prostaglandin metabolism, inhibition of activators stemming from damaged endothelial cells, and other effects have to be considered.

Animals↗
PubMed1983

The effect of contrast media on the aortic endothelium of rats.

The effect of diatrizoate, ioxitalamate, metrizamide, and ioxaglate on the aortic endothelium of the rat was investigated using transmission electron microscopy and DNA synthesis autoradiography. One milliliter of each contrast medium, containing 300 mg iodine per ml, was injected into the aorta. The types of lesions seen on electron microscopy and the rate of DNA synthesis seen on autoradiography established the degree of endothelial damage that had been produced. Of the four contrast agents tested, ioxaglate produced the least amount of cellular change.

Animals↗
PubMed1983

[Calcification of the arterial wall in the aging process. Electron microscopic and biochemical studies of a model of vitamin D3 overdose].

The following mechanisms for inactivating excessive Ca++ are found in the vessel wall (e.g. in old age, arteriosclerosis, hypertension, or overdosage with Vitamin D3): 1. The production of Matrix Vesicles, which reduce biologically active extracellular Ca++ by precipitating it during the initial stage of calcification. 2. An increase in the number of muscle cells changed from the "k" to the "m" form. These also possess a mechanism for reducing the intracellular Ca++ level. If in spite of these mechanisms the extracellular Ca++ concentration remains raised, this can result in calcification of the interzellular substance, particularly the elastic material.

Aged↗
PubMed1982

[The effect of benzarone on serum lipids and arterial wall of cholesterol fed rats].

Rats of BD X strain and SHR/NIH Montreal Ingelheim strain (genetic hypertension) received a diet containing 3.9% cholesterol or 3.7% cholesterol plus 0.6% benzarone, respectively, and libitum for 5 or 9 months. The following chemical and ultrastructural results were obtained. 1. The cholesterol-benzarone diet causes a body weight reduction of 10%, a relative increase of serum HDL and a corresponding decrease of serum LDL and VLDL, as compared with the effects of the cholesterol diet. No differences of total serum cholesterol and serum triglycerides between the two groups were observed. 2. The aorta of cholesterol fed animals shows a slight but statistically not significant increase of total cholesterol content. 3. No differences in the composition of connective tissue components (collagen, elastin, uronic acid content) between the cholesterol fed animals and a control group on normal diet could be detected. 4. Electron micrographs of several vessel wall areas from cholesterol fed hypertensive animals revealed fibrosis, necrosis of media muscle cells and an increase of matrix vesicles. Severe damages were found in coronary arteries and in the caudal arteries. 5. Cholesterol feeding of hypertensive rats increases the cholesterol content of liver 10fold and the triglycerides content 3fold as compared with liver lipids of control rats. Benzarone application to cholesterol fed rats effects a statistically significant decrease of liver cholesterol and triglycerides.

Animals↗