Biomedical subjects

G Feigl

Publications and source records attributed to G Feigl.

6 recordsLinked to original sources

PubMed2007

[Meaning of stylopharyngeal fascia in intraoral block techniques].

BACKGROUND: The almost unknown stylopharyngeal fascia may be one of the reasons for unsuccessful therapy of the trigeminal neuralgia by a transoral block of the superior ganglion of the sympathetic trunk. We investigated the anatomy of the fascia to show the efficiency of the block for this therapy. MATERIALS AND METHODS: 103 halves of human heads were investigated. The stylopharyngeal fascia was dissected by a lateral approach. We classified three groups. Group A was formed by fascias without perforation, group B by perforated fascias and group C by all halves without a developed fascia. RESULTS: We found a fully developed fascia in 86 cases. 13 halves had perforated fascias; in 4 cases the fascia was not developed. CONCLUSION: The stylopharyngeal fascia may inhibit the distribution of opoids into the infratemporal fossa associated with a consecutive block of the mandibular nerve and lower the rate of pain relief.

Adult↗

PubMed2006

A supraomohyoidal plexus block designed to avoid complications.

Interscalene blocks of the brachial plexus are used for surgery of the shoulder and are frequently associated with complications such as temporary phrenic block, Horner syndrome or hematoma. To minimize the risk of these complications, we developed an approach that avoids medially directed needle advancement and favors spread to lateral regions only: the supraomohyoidal block. We tested this procedure in 11 cadavers fixed by Thiel's method. The insertion site is at the lateral margin of the sternocleidomastoid muscle at the level of the cricoid cartilage. The needle is inserted in the axis of the plexus with an angle of approximately 35 degrees to the skin, and advanced in lateral and caudal direction. Distribution of solution was determined in ten cadavers after bilateral injection of colored solution (20 and 30 ml) and followed by dissection. In an eleventh cadaver, computerized tomography and 3D reconstruction after radio contrast injection was performed. In additional five cadavers we performed Winnie's technique with bilateral injection (20 and 30 ml). Concerning the supraomohyoidal block the injection mass reached the infraclavicular region surrounded all trunks of the brachial plexus in the supraclavicular region and the suprascapular nerve in all cases. The solution did not spread medially beyond the lateral margin of the anterior scalene muscle into the scalenovertebral triangle. Therefore, phrenic nerve, stellate ganglion, laryngeal nerve nor the vertebral artery were exposed to the injected solution. Distribution was comparable with the use of 20 and 30 ml of solution. Injections on five cadavers performing the interscalene block of Winnie resulted in an extended spread medially to the anterior scalene muscle. We conclude that our method may be a preferred approach due to its safety, because no structures out of interest were reached. Solution of 20 ml is suggested to be enough for a successful block.

Brachial Plexus↗

PubMed2006

[Block of the superior cervical ganglion of the Truncus sympathicus. Why it often is not possible!].

BACKGROUND: For the transoral block of the superior cervical ganglion (SCG) of the sympathetic trunk we investigated the dissemination of three of three different volumes. The aim was to find an ideal volume and reasons for a failure of the technique. MATERIAL AND METHODS: 40 preserved heads were investigated. 35 were injected with the contrast agent Jopamiro. 1 ml was applied on the left side of 30 heads, 2 ml on all right sides. 5 heads were injected with 5 ml into the parapharyngeal space (PPS) on the right and into the prevertebral space (PVS) on the left side. All heads were investigated by CT-Scans and 3D reconstruction. 5 cadavers were injected with 5 ml blue coloured water for dissection. RESULTS: 1 or 2 ml showed very similar dissemination. To reach the PPS, the needle had to be pushed laterally or, if the direction was changed more medially, the needle had to be pulled back. Feeling two resistances, the PVS was reached instead of the SCG. 5 ml spread to other regions of the head. CONCLUSION: 1 ml seems to be sufficient to block the SCG. The guidelines have to be strictly followed to avoid failure of the block. 5 ml disseminate to unexpected and undesirable regions.

Autopsy↗

PubMed2004

Single lamellar mechanics of the human lumbar anulus fibrosus.

The mechanical behavior of the entire anulus fibrosus is determined essentially by the tensile properties of its lamellae, their fiber orientations, and the regional variation of these quantities. Corresponding data are rare in the literature. The paper deals with an in vitro study of single lamellar anulus lamellae and aims to determine (i) their tensile response and regional variation, and (ii) the orientation of lamellar collagen fibers and their regional variation. Fresh human body-disc-body units (L1-L2, n=11) from cadavers were cut midsagittally producing two hemidisc units. One hemidisc was used for the preparation of single lamellar anulus specimens for tensile testing, while the other one was used for the investigation of the lamellar fiber orientation. Single lamellar anulus specimens with adjacent bone fragments were isolated from four anatomical regions: superficial and deep lamellae (3.9+/-0.21 mm, mean +/- SD, apart from the outer boundary surface of the anulus fibrosus) at ventro-lateral and dorsal positions. The specimens underwent cyclic uniaxial tensile tests at three different strain rates in 0.15 mol/l NaCl solution at 37 degrees C, whereby the lamellar fiber direction was aligned with the load axis. For the characterization of the tensile behavior three moduli were calculated: E(low) (0-0.1 MPa), E(medium) (0.1-0.5 MPa) and E(high) (0.5-1 MPa). Additionally, specimens were tested with the load axis transverse to the fiber direction. From the second hemidisc fiber angles with respect to the horizontal plane were determined photogrammetrically from images taken at six circumferential positions from ventral to dorsal and at three depth levels. Tensile moduli along the fiber direction were in the range of 28-78 MPa (regional mean values). Superficial lamellae have larger E(medium) (p=0.017) and E(high) (p=0.012) than internal lamellae, and the mean value of superficial lamellae is about three times higher than that of deep lamellae. Tensile moduli of ventro-lateral lamellae do not differ significantly from the tensile moduli of dorsal lamellae, and E(low) is generally indifferent with respect to the anatomical region. Tensile moduli transverse to the fiber direction were about two orders of magnitude smaller (0.22+/-0.2 MPa, mean +/- SD, n=5). Tensile properties are not correlated significantly with donor age. Only small viscoelastic effects were observed. The regional variation of lamellar fiber angle phi is described appropriately by a regression line |phi|=23.2 + 0.130 x alpha (r(2)=0.55, p<0.001), where alpha is the polar angle associated with the circumferential position. The single anulus lamella may be seen as the elementary structural unit of the anulus fibrosus, and exhibits marked anisotropy and distinct regional variation of tensile properties and fiber angles. These features must be considered for appropriate physical and numerical modeling of the anulus fibrosus.

Anisotropy↗

PubMed1991

Sequence comparison of the sodium-D-glucose cotransport systems in rabbit renal and intestinal epithelia.

Using an isolated 1.2 kbp PCR product as specific probe, the rabbit renal cortex sodium-D-glucose cotransport system has been found and cloned from a renal cortex cDNA library. Two overlapping cDNA clones were found, one with a length of 2.1 kbp and one of 1.1 kbp resulting in a total sequence of 2.2 kbp without the poly(A) tail. Northern blot hybridization indicated a transcript of approx. 2.4 kb in size. Tissue distribution in the rabbit kidney and intestine indicates that this sequence is present in renal cortex, renal medulla and small intestine in different proportions. It is proposed that this clone codes for a member of the sodium-D-glucose cotransporter systems.

Amino Acid Sequence↗

PubMed1989

A member of the steroid hormone receptor gene family is expressed in the 20-OH-ecdysone inducible puff 75B in Drosophila melanogaster.

Drosophila melanogaster DNA has been cloned which encompasses a major part of the 20-OH-ecdysone inducible puff 75B. One 20-OH-ecdysone responsive transcription unit was detected which is expressed into two transcripts which accumulate upon the incubation of salivary glands of 3rd instar larvae with 20-OH-ecdysone. This accumulation is correlated with the 20-OH-ecdysone induced activity of puff 75B. 75B cDNA analysis indicates that the activity of puff 75B leads to the synthesis of a protein which belongs to the steroid and thyroid hormone receptor superfamily. The highest similarity of the derived 75B protein sequence was found to the DNA and ligand binding domains of human retinoic acid receptor. A study of the tissue distribution in larvae revealed that 75B mRNA is present in most, if not all 20-OH-ecdysone target tissues. It is proposed that 75B protein is a DNA-binding protein playing a key role in mediating the regulation of the larval molt by 20-OH-ecdysone.

Amino Acid Sequence↗