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Biomedical subjects

W Firbas

Publications and source records attributed to W Firbas.

At least 55 records · Page 3Linked to original sources
PubMed1990

The microvasculature of the guinea pig ureter. A scanning electron microscopic investigation.

In 24 albinotic guinea pigs (Cavia porcellus) the gross vasculature and the microvascular architecture of the ureter were studied by light microscopy of tissue blocks and by scanning electron microscopy of vascular casts. The guinea pig ureter is supplied by the renal artery proximally, by the aorta and the internal iliac artery in its mid-segment, and by the uterine and prostatic as well as by the vesical arteries distally. The main arterial trunks run alongside the ureter before they branch to send perforating arterioles to the muscular coat and the mucosal lining. The draining venules are found on both sides of the ureter and form transverse anastomoses. Communications between the arterioles are also located on both sides, but longitudinally arranged. The capillary network of the mucosal lining shows an undulating pattern with tortuous vessels and lies just below the epithelium. The muscular coat and the adventitia have no prominent capillaries of their own. Large arteries are embedded in the adventitia, large veins in the lamina propria. In analogy to human anatomy the vascular arrangement found suggests that, if the ureters are excised in transplant surgery, a lateral incision should be used for the abdominal portion, while the pelvic portion is best approached by a medial incision.

Animals↗
PubMed1990

[ Topography of carpal bone - An experimental model for carpal tunnel syndrome ].

By preparing a new experimental model for the carpal tunnel syndrome, the authors evaluated the differences of the human and rabbit carpal tunnels using a comparative anatomical study. A nearly identical situation-regarding the osseous and connective tissue formations in the carpal channel--was found. Therefore, the carpal tunnel of the rabbit is recommended for a model of chronic nerve compression, which is now planned by the authors.

Animals↗
PubMed1989

The extensor apparatus of the knee joint and its peripheral vasti: anatomic investigation and clinical relevance.

Anatomic dissections of the vastus medialis m. in 115 fixed thigh specimens always demonstrated a clear separation between a long head of the muscle (VML) inserted at the base of the patella and a short head (VMO) inserted at its medial margin. The plane of separation was identified by a branch of the femoral n. in every case. In 17 instances, the localization of the nerve was superficial; in 57, it was in the areolar fascial plane; and in 41 instances in lay deeply between the muscles. The ramification of the branch of the femoral n. traversing the plane of separation showed 4 types of variation. Dissections of the vastus lateralis m. in 42 specimens always demonstrated a separation into 2 heads: a long head inserted at the base of the patella (VLL) and a short head inserted at its lateral margin (VLO). The directions of the individual heads of the quadriceps femoris m. were angulated in relation to the long axis of the femur. The deviations were between 10 degrees and 17 +/- 8 laterally for the vastus lateralis longus m. (VLL), between 26 degrees and 41 degrees laterally for the vastus lateralis obliquus m. (VLO), between 15 degrees and 18 degrees medially for the vastus medialis longus m. (VML), and between 46 degrees and 52 degrees medially for the vastus medialis obliquus m. (VMO). The results demonstrate great variation in the distal parts of the medial and lateral anterior thigh m.

Humans↗
PubMed1989

Esophageal vasculature in the guinea pig: a scanning electron microscope study of vascular corrosion casts.

The esophageal vascularization of adult male and female albinotic Guinea pigs (Cavia porcellus) is studied by means of light microscopically evaluated serial sections and by scanning electron microscopy (SEM) of vascular corrosion casts. Bronchoesophageal artery (cervical portion), direct branches of the aorta, recurrent branches of the intercostal arteries (thoracic portion) as well as of the left gastric artery (abdominal portion) supply the esophagus; internal jugular vein, inferior thyroid vein (cervical portion), azygos vein, intercostal veins (thoracic portion) and portal vein, gastroepiploic vein and cranial pancreatoduodenal vein (abdominal portion) drain it. Longitudinally arranged arterioles, venules and capillaries lying at the level of the lamina propria of the esophageal mucosa around the whole circumference of the organ are the most striking vascular features, whereby the venules are considered as those vessels from which esophageal varices arise under pathological conditions.

Animals↗
PubMed1989

[The innervation of the human esophagus].

There are usually 3 left and 4 right esophageal branches of the sympathetic chains. Besides a direct approach to the organ, they form a delicate network between aorta and esophagus. This network exchanges fibers with the vagus nerves. The vagal supply of the cranial third is rather poor. It is richest in the middle third. As a rule, the left anterior, left posterior, right anterior and right posterior main branches can be prepared. There are relatively few communications between right and left ramuli. Above the esophageal hiatus, always quite distinct anterior vagal chords are found, while posteriorly there are usually only very thin nerve bundles.

Adult↗
PubMed1988

Surgical anatomy of the upper vertebral artery.

A surgical approach to the upper vertebral artery between C1 and C2 is described. Following dissection of the posterior border of the sternocleidomastoid and the anterior border of the splenius capitis the two muscles are held apart and the levator scapulae is transected at its origin from C1. The cranial end of the vertebral artery can now be connected with the common carotid or external carotid arteries.

Autopsy↗
PubMed1988

Sonoanatomy of the muscles of facial expression.

Primary anatomic studies served for identification and differentiation of the individual mimetic muscles. As a second step, we investigated the clinical potential of ultrasound imaging to visualize the mimetic musculature in 15 volunteers. This examination technique was used to diagnose pathological alterations, especially associated with facial palsy. The excellent sonographic visualization of the mimetic musculature indicates that this technique may be a valuable adjunct in the diagnosis and differentiation of facial palsy, as well as in planning plastic surgery and reconstructive procedures, and in follow-up care.

Adolescent↗
PubMed1988

Photogrammetry of the muscles of facial expression.

The present study has attempted to determine the volume, square measure as well as length, width and thickness of the individual muscles of facial expression by photogrammetry. 15 fresh male head specimens were employed for a careful dissection of muscle layers. The volume was measured using the immersion procedure. The mean values of each parameter together with the standard deviation were summarized. The results suggest that this novelty in the representation of the mimetic muscles will facilitate the planning of corrective interventions in plastic surgery. Moreover, photogrammetry offers additional information on the required size and measurements of donor muscles.

Aged↗
PubMed1988

Correlations between posterior gastric artery and superior polar artery in human anatomy.

We investigated the correlations in incidence and anatomy of 2 splenic artery branches, the Posterior Gastric Artery (PGA) and the Superior Polar Artery (SPA). In the literature these 2 branches were never described on one and the same splenic artery. We studied the splenic arteries of 126 corpses and found a cranio-sinistrally directed branch of the splenic artery in 76.2%. It appeared as a PGA (only stomachial supply) in 27.7% and as a SPA (only splenic supply) in 3.27%. In the most cases we detected an intermediate-type--we called it "gastrosplenic artery = GSA"--having a posterior gastric and a superior polar branch simultaneously. Such a "gastrosplenic artery" leaves the main trunk of the splenic artery in its middle segment in cranio--sinistral direction and falls apart into a posterior gastric and a superior splenic branch both with various differences in caliber. All these variations are described, nomenclature and the functional and surgical importance of these findings are discussed.

Aged↗
PubMed1986

Anatomical bases of patellar tendon grafts used in anterior cruciate ligament reconstruction.

In 24 fresh specimens the blood-supply of the infrapatellar fat-pad was investigated by injection. In some of the specimens, Clancy's pedicled patellar tendon graft for anterior cruciate ligament reconstruction had been performed before injection. The fat-pad is supplied by vessels forming a plexus supplying the tendon. In the tendon grafts injected after Clancy's procedure, no vessels were found penetrating the patellar tendon at its patellar and tibial attachments. Filled vessels were found by histologic methods and the Spalteholz technique.

Dissection↗
PubMed1986

Prostacyclin formation around human abdominal aortic ostia.

Earlier studies have demonstrated an age dependent effect in the extent of sudanophilic and atherosclerotic lesions around aortic ostia in men. As prostacyclin may be a key determinant in the development of atherosclerosis we examined its formation around abdominal aortic ostia (coeliac, superior mesenteric and inferior mesenteric arteries) in-vitro. Prostacyclin formation was higher distal to the orifice as compared to proximal areas, but without reaching the level of significance. Prostacyclin formation was always higher in females than in males and in nonsmokers than in smokers, showing the greatest difference distal to the ostium, but again without significance. From the limited number of vessels examined, no trend for an age dependency can be noted. The relation between prostacyclin generation and morphological data is discussed.

Adolescent↗
PubMed1986

Sonoanatomy of the shoulder.

With the aid of ultrasound we tried to visualize the muscles of the shoulder region, the collum scapulae, the axillary artery and vein and the brachial plexus. We were successful with exception of the vessels and the nerves. Knowledge of the anatomical landmarks is essential in ultrasound image reading.

Axillary Artery↗
PubMed1986

Sonography of the tongue and floor of mouth.

The study about the sonoanatomy of the tongue and the floor of the mouth was undertaken with 20 volunteers. A description of the examination technique is given in comparison with computerized tomography. It is pointed out that it is easier to adjust the section planes optimally to the anatomical situation with ultrasound. This examination technique is noninvasive and easy to do. It is comfortable for the patient and can be repeated frequently, for example it allows a follow-up of cancer patients. Finally--this technique is cheap and can be performed at any given place.

Adolescent↗
PubMed1986

[Prostacyclin- and thromboxane synthesis in the vascular wall after gammatron irradiation].

One year aged rabbits were exposed to a single dose of 100, 500 or 1000 rd (1.0, 5.0 or 10 Gy) to the abdominal aorta. The non-irradiated thoracic aortic segment served as control. The animals were killed between one and 336 hours after the irradiation. Four animals were examined in each group. The prostacyclin formation was assessed by means of a radioimmunoassay against its stable breakdown 6-oxo-PGF1 alpha, the thromboxane A2-formation using a radioimmunoassay for thromboxane B2. Local irradiation causes a temporary increase of both the compounds. In contrast to thromboxane B2, the 6-oxo-PGF1 alpha exhibits a long-lasting depression. The higher the radiation dose, the more intensive the increase and the long-lasting depression of 6-oxo-PGF1 alpha. The liberation of eicosanoids and subsequent hemostatic dysregulation at different intervals after irradiation might contribute to an important extent to the radiation induced vasculopathy.

Animals↗
PubMed1986

[A procedure for the determination of spinal cord length in vivo].

Using anthropological methods, we measured the body height, length of the spine (ventral and dorsal), leg length, cord length. The data were evaluated statistically and we looked for correlation between leg length and body height, cord length and length of the spine, length of the spine and body height. On the basis of our results, we were able to determine the cord length for clinical use by computing the regression coefficient of leg length and spinal length.

Adult↗