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W Firbas

Publications and source records attributed to W Firbas.

At least 73 records · Page 4Linked to original sources
PubMed1986

[Surgical anatomy of the internal carotid artery].

Starting from the carotid trigone, a surgical approach to the parapharyngeal part of the internal carotid artery is described. The retrostyloidal part of the lateropharyngeal space is opened up from laterocaudal after resecting the posterior belly of the digastric muscle and the styloidal muscles. Vulneration of the cranial nerves (VII, IX, X) has to be prevented.

Carotid Artery, Internal↗
PubMed1986

[Connection of the ligamentum coracoglenoidale with the muscular pectoralis minor].

The ligamentum coracoglenoidale and its connection with the m. pectoralis minor are described. We have found three different shapes of this ligament. In 47% of the dissected specimens it was a strong round ligament, and in 39% it was a membraneous ligament that always inserted above the lig. coracohumerale. In 14%, separation of the lig. coracoglenoidale from the lig. coracohumerale at the coracoidal insertion was either impossible at all or only feasible by sharp dissection. In 16% we found a bundle of fibres of the m. pectoralis minor running over the processus coracoideus towards the head of the scapula. In two instances this bundle inserted at the humeral head. Possibly, there is a similar function as that of the meniscotibial and the meniscofemoral ligaments of the knee joint. A connection with the 'impingement syndrome' of the shoulder joint will be the base of further investigations.

Adolescent↗
PubMed1985

Incidence, anatomy and territories supplied by the posterior gastric artery.

The posterior gastric artery, a branch of the splenic artery to the posterior gastric wall, was described for the first time by Walther in 1729. It was often recognized by many authors since, but consequently ignored by anatomical and surgical textbooks until its rediscovery and description by Suzuki et al. [Ann. Surg. 187: 134-136, 1978]. The incidence of the posterior gastric artery differs between 4 and nearly 100%. All authors describe posterior gastric regions being supplied by the posterior gastric artery, but sometimes also a branch running towards the superior pole of the spleen is cited. In our study of 104 corpses we found the posterior gastric artery with an incidence of 37.5%. In one third of these cases, a branch of the posterior gastric artery to the superior pole of the spleen was also detectable. Besides these results, the course of the posterior gastric artery to the corresponding organs and the importance of this vessel for the abdominal surgeon are discussed.

Adolescent↗
PubMed1985

Irradiation depresses prostacyclin generation upon stimulation with the platelet-derived growth factor.

Experimental and clinical findings demonstrated rather severe arterial lesions occurring in irradiated arteries. It is suggested that a local haemostatic imbalance might be one causative factor. Liberation of PDGF causes smooth-muscle cell proliferation and PGI2 formation by the arterial wall cells, inhibiting in turn further release of PDGF from the alpha granules of the platelets. A decreased ability of irradiated vascular segments to generate PGI2 upon PDGF stimulation described here might cause haemostatic imbalance and subsequent radiation-induced lesions.

Animals↗
PubMed1985

[A semiquantitative method of determining alkaline phosphatase activity in human arterial wall].

A new method of semi-quantification of the alkaline phosphatase enzyme activity in human vascular tissue is described. An index is derived from the number of alkaline positive cells and the different levels of intensity of the staining reaction. In the autopsy and surgical material of male and female subjects aged between 40 and 60 a, we evaluated the alkaline phosphatase enzyme reaction of normal and atherosclerotic arteries after various incubation intervals. Tissue samples were obtained from aorta, common carotid artery, renal artery, splenic and anterior tibial artery, and Sparks prosthetic graft.

Adult↗
PubMed1984

Long-lasting depression of rabbit aortic prostacyclin formation by single-dose irradiation.

Male rabbits were exposed to a single irradiation dose of 1000-5000 rad when 12, 15, 16, and 17 months old and were killed when 18 months old (i.e., 1, 2, 3, and 6 months after irradiation). Even after this long interval after irradiation, abdominal aortic prostacyclin formation was significantly depressed, whereas the nonirradiated thoracic aortic segment exhibited no significant alteration in vascular PGI2 generation. The data show that the severe decrease in PGI2 synthesis was not caused by deendothelialization induced by irradiation alone. The data support the view that a deterioration in the prostaglandin system regulating hemostatic balance is an important determinant in the development of radiation-induced vasculopathy.

Animals↗
PubMed1983

[Cells of the vascular wall synthesize thromboxane].

Cultured endothelial and smooth muscle cells, as well as vascular tissue samples derived from human coronary arteries and minipig aorta produce thromboxane A2 in trace amounts. The identity of this substance was characterized using a specific thromboxane synthetase inhibitor. Thromboxane (TXB2) was measured by means of specific radioimmunoassay. The biological importance of this phenomenon is unclear.

Animals↗
PubMed1983

[Radiation vasculopathy--caused by a change in vascular prostacyclin synthesis?].

Earlier investigations revealed morphological damage of the vascular wall after radiotherapy. The present investigation was undertaken to determine whether vascular prostacyclin synthesis plays a causative role in the genesis of vasculopathy. Rabbits were exposed to a focal radiation dose of between 500 and 5000 rad over various time intervals. Vascular PGI2-synthesis increased significantly immediately after radiation, with a subsequent decrease over the following days to levels below the starting values. Each repeated radiation dose induced a significant increase in PGI2-synthesis again. These observations were paralleled by severe morphological alterations, mainly localized in endothelial cells and elastic material. The findings suggest that a deterioration in PGI2-synthesis plays a key role in the genesis of radiation-induced vasculopathy.

Animals↗
PubMed1983

The efferent innervation of the avian cochlea.

The efferent auditory innervation of the budgerigar (Melopsittacus undulatus) was investigated by means of acetylcholinesterase staining. The course of the efferent fibres is described: the single terminal fibre regularly branches out to innervate several hair cells. Three types of efferent, axosomatic synapses could be distinguished: small outer hair cells bear large cup-like efferent synapses, intermediate hair cells with cone-shaped synapses, and tall inner hair cells with small, knob-like synapses. In the basal part of the cochlea the small hair cells with heavy efferent endings predominate, while in the apex only tall inner hair cells with small efferent terminals exist. There are more intermediate hair cells in the apical area than in the basal area.

Animals↗
PubMed1982

Radiation induced alterations in rabbit aortic prostacyclin formation.

Earlier studies have demonstrated very severe vascular lesions occuring after irradiation in human and experimental animals as well. We examined the rabbit aortic PGI2-formation using the platelet bioassay technique in one year aged rabbits after different irradiation doses and a time course. The findings demonstrate a significant increase in prostacyclin formation, which might be due to the damage of endothelial cells. This stage is followed by a long lasting severe depression. This behaviour in addition demonstrates a dose dependent manner, The findings of a long lasting decrease in vascular PGI2-formation might contribute to the understanding of the high incidence of vascular lesions being found at the site of irradiation.

Animals↗
PubMed1981

The blood vessels of the limbus spiralis.

The capillaries of the spiral limbus in the cochlea of the laboratory rat were investigated under light and electron microscopy. A stereological examination of the capillary volumes of specimens injected with horseradish peroxidase was performed. The volume of capillaries amounted to 2.87%, and, as such, is very high. The ultrastructure of the capillaries showed continuous endothelial cells and basal laminae, discontinuous pericytes and varying relations towards the surrounding tissue. Morphological criteria, such as microvilli and plasmalemmal vesicles, suggest a significant transendothelial transport. The causes for the abundance of vessels in the spiral limbus are discussed: the transport of oxygen to the perilymph and the need of substances for the formation of the tectorial membrane seem to be important factors. The transport processes are obviously controlled by the endothelial cells as well as by the spiral limbus cells.

Animals↗
PubMed1980

[The anatomy of the Isthmus pharyngis (author's transl)].

The boundary between the nasal and oral part of the pharynx has not yet been named definitely in surgical anatomy. The term Isthmus pharyngis in analogy to Isthmus faucium is proposed and the anatomy of this region is described. The importance of these structures in reconstructive surgery is emphasized.

Humans↗