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Biomedical subjects

R Siegert

Publications and source records attributed to R Siegert.

At least 19 recordsLinked to original sources
PubMed2006

[Techniques in otoplasty].

A great number of surgical techniques for the correction of protruding ears have been developed. Their basic concepts originate from Mustardé's suture, the scoring technique described by Chongchet, Stenström, and Cricelair, and the combined suture and scoring technique described by Converse. Techniques for cavum rotation and lobuleplasty have also been presented. Indication, diagnostics, selection of method, the operative technique itself, and postoperative care are described. Advantages and risks of each technique are discussed, and a therapy algorithm is proposed.

Ear Cartilage↗
PubMed2004

[New surgical techniques for the treatment of auricular atresia].

The rehabilitation of patients having severe malformation of the auricle with congenital auricular atresia requires plastic surgery and audiologic treatment. After classifying these malformations, various options involving hearing aids and surgery are presented. The main focus is on our new technique of combined auricular reconstruction with construction of the external ear canal and tympanoplasty, the so-called atresia-operation. It is characterised by three steps combining plastic and otologic surgery with prefabrication of the tympanic membrane and the external ear canal. Finally, our current rehabilitation concept for these patients is presented.

Abnormalities, Multiple↗
PubMed2003

[Surgical treatment of severe velopharyngeal insufficiency following uvulopalatopharyngoplasty (UPPP)].

BACKGROUND: For the implementation of an uvulopalatopharyngoplasty (UPPP) it is nowadays common practice to operate in a manner which is gentle on the tissue and which retains as much muscle as possible. However, even when the greatest possible care is taken during the operation, serious complications such as persistent velopharyngeal insufficiency can arise. PATIENT AND METHOD: Based on a case report of a 55 year old man with a persistent severe velopharyngeal insufficiency after UPPP performed at another institution and serious OSA, we suggest a so-called push back technique, adapted from the cleft-palate surgery, for the extension of the soft-palate. With regard to the operative technique, it is thus possible to produce an effective extension of the soft-palate by means of a dorsocaudal displacement of a wide and on the palatal vascular fascicle pedicled mucoperiosteum flap of the mucous membrane of the hard palate, as well as similar mobilisation of the soft-palate from the os-palatinum. RESULT: Only 3 weeks after the operation, our patient showed a clinically sufficient velopharyngeal functioning. After 3 months, a complete restoration of the nasal CPAP-acceptance was evident. As a result, a complete social rehabilitation was possible for our patient. CONCLUSION: The modified push back technique of the palate retrodisplacement which is described above offers an efficient possibility of anatomically and functionally correcting the persistent and serious velopharyngeal insufficiency after UPPP.

Deglutition Disorders↗
PubMed2003

Comparison of the efficacy and safety of moxifloxacin and trovafloxacin for the treatment of acute, bacterial maxillary sinusitis in adults.

In this multicentre, multinational, comparative, double-blind clinical trial, out-patients with both symptoms and radiographic evidence of acute sinusitis were randomly assigned to receive either a seven-day, once daily (o.d.) oral regimen of moxifloxacin (400 mg) or a 10-day o.d. oral regimen of trovafloxacin (200 mg). Among 452 patients considered valid for clinical efficacy, moxifloxacin treatment was found to be statistically equivalent to trovafloxacin (96.9 per cent vs 92.1 per cent -95 per cent CI = 0.6 per cent; 8.9 per cent) at the seven to 10 days post-therapy assessment. At follow-up, the success rate in the moxifloxacin group was 94.9 per cent and that for the trovafloxacin group was 97.6 per cent (95 per cent CI = -4.9 per cent; 1.3 per cent). The predominant causative organisms were Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus followed by Enterobacteriaceae and Moraxella catarrhalis. The bacteriological success rate at the post-therapy evaluation was similar in both treatment groups: 94.4 per cent and 90.1 per cent in the moxifloxacin and trovafloxacin groups respectively (95 per cent CI = -3.0 per cent; 11.9 per cent). Only three of the 103 baseline isolated pathogens still persisted in the moxifloxacin group, whereas there were 10 of the 121 isolates that failed to respond in the trovafloxacin treatment group. At least one drug-related event was reported by 16.9 per cent of the moxifloxacin-treated patients and by 22.3 per cent of those who received trovafloxacin. CNS events such as dizziness and vertigo were reported more than five times more often in patients receiving trovafloxacin than in the moxifloxacin group. Trovafloxacin recipients were also more than twice as likely to discontinue treatment due to adverse events than moxifloxacin-treated patients. Overall, moxifloxacin was at least as effective clinically and bacteriologically as trovafloxacin and better tolerated.

Acute Disease↗
PubMed2002

[Reconstruction after extended partial laryngeal and hypopharyngeal resections. A new method with rib cartilage, chondrosynthesis and free radial transplants].

UNLABELLED: Partial pharyngectomy combined with subtotal laryngectomy results in permanent tracheostomy and long lasting swallowing difficulties in many cases. Based on our prior experimental and clinical studies on laryngeal chondrosynthesis the objectives of this project were to develop a method for reconstruction of up to two thirds of the larynx and one pyriform sinus. METHOD: The resected laryngeal framework is reconstructed with autogenous rib cartilage and stabilized with plates and screws. In addition a piece of cartilage is used as a buttress for apposition by the remaining mobile vocal cord. A free radial forearm flap covers the reconstructed framework and forms the sulcus of the pyriform sinus. RESULTS: Up to now 7 patients have been operated with this technique. The follow up was 35 months on average. None of the patients has a clinically relevant aspiration. All patients have a well understandable voice and one of them--a teacher--could even resume his speech profession. CONCLUSION: In selected patients these techniques enable functional rehabilitation of swallowing, breathing and speech even after extended partial pharyngolaryngectomy.

Aged↗
PubMed2001

Two-step external ear canal construction in atresia as part of auricular reconstruction.

OBJECTIVES: One of the common complications of atresia surgery is restenosis of the surgically constructed external ear canal. To avoid this complication, a new two-step technique of creating an external ear canal was developed and evaluated. STUDY DESIGN: Prospective clinical evaluation. PATIENTS AND METHODS: Thirty-six patients with third-degree microtia and aural atresia have been treated this way. In the first step, the canal is drilled into the petrous bone, a Silastic cylinder is inserted and wrapped into pieces of cartilage and bone dust. In the second step several months later, the implant is removed and a slightly smaller tube covered with a split thickness skin graft is inserted. RESULTS: Except the first three patients operated with a slightly different technique, none of the following 33 patients showed a severe restenosis. Instead, all had a nice, smooth external ear canal. CONCLUSION: With this two-step technique of creating a new external ear canal in atresia, we could avoid one of the major complications of this kind of surgery. The external ear canal is either necessary for the reconstructed middle ear or it can be used to adapt a (behind or in the ear) hearing aid. By integrating this technique into a three-step concept for auricular reconstruction, the patient does not need any additional operation, and his or her rehabilitation from ear malformation can be enhanced.

Adult↗
PubMed2001

Water-jet dissection in parotid surgery: an experimental study in dogs.

OBJECTIVE: The objective of the present study was to investigate the application of the water-jet dissection method in parotid surgery by way of animal experiments, paying particular attention to the clinical and histological reactions of the facial nerve. STUDY DESIGN: An animal experimental study. METHODS: Total bilateral parotidectomies with retention of the facial nerve were performed on 19 beagle dogs by means of the Hydro-Jet device (Andreas Pein Medizintechnik Company, Schwerin, Germany) using different jet diameters and operating pressures. All operations were performed with continuous intraoperative facial monitoring (Neurosign 100, Inomed Company, Teningen, Germany). The dogs were monitored postoperatively over an average period of 20.3 days (range, 14-35 d). Local findings and facial nerve status were documented daily. In a second phase, the dissected nerves were resected and the animals were killed. Samples of water-jet-dissected parotid tissue, as well as all dissected nerve branches, underwent histological examination and were compared with clinical and electrophysiological findings. RESULTS: It was possible to perform operations easily on all parotid glands by means of the Hydro-Jet using the small, 120-microm jet at operating pressures of 40 to 60 bar and to dissect the facial nerve quickly and safely with retention of its functional capability (n = 34). The dissection of nerves using larger-diameter jets (150 and 200 microm [n = 64]) resulted in a total of two reversible and seven irreversible partial pareses. CONCLUSIONS: The study has shown that it is possible to perform tissue-selective operations on the parotid gland by means of the Hydro-Jet using the 120-microm jet at operating pressures of 40 to 60 bar, ensuring safe, atraumatic dissection of the facial nerve with retention of its functional capability. The advantages of the new Hydro-Jet method offer a valuable alternative compared with the normal dissection methods adopted in parotid surgery. Thus the results of the present investigation currently are being checked within the framework of a clinical study at our clinic.

Animals↗
PubMed2000

Structure of the molecular chaperone prefoldin: unique interaction of multiple coiled coil tentacles with unfolded proteins.

Prefoldin (GimC) is a hexameric molecular chaperone complex built from two related classes of subunits and present in all eukaryotes and archaea. Prefoldin interacts with nascent polypeptide chains and, in vitro, can functionally substitute for the Hsp70 chaperone system in stabilizing non-native proteins for subsequent folding in the central cavity of a chaperonin. Here, we present the crystal structure and characterization of the prefoldin hexamer from the archaeum Methanobacterium thermoautotrophicum. Prefoldin has the appearance of a jellyfish: its body consists of a double beta barrel assembly with six long tentacle-like coiled coils protruding from it. The distal regions of the coiled coils expose hydrophobic patches and are required for multivalent binding of nonnative proteins.

Amino Acid Sequence↗
PubMed2000

[Bilateral acoustic trauma after air bag inflation].

Airbag inflation is associated with a loud noise. This very short noise has a peak amplitude of 170 dB sound pressure level and can make otologic injuries. We report a case of acoustic trauma after airbag inflation. The 24-year-old man has hearing loss both side in the 3000- to 6000-Hz range and in the deep-frequency. The possibility of acoustic trauma from airbag noise are probably much more common and need more attention in the clinic.

Adult↗
PubMed2000

A comparison of the safety and efficacy of moxifloxacin (BAY 12-8039) and cefuroxime axetil in the treatment of acute bacterial sinusitis in adults. The Sinusitis Study Group.

The aim of this multicentre, randomized study was to compare the efficacy and safety of moxifloxacin (BAY 12-8039), a new 8-methoxy fluoroquinolone, with that of cefuroxime axetil for the treatment of acute bacterial sinusitis in adults. Diagnosis was made on a range of clinical signs and symptoms combined with radiology and microbiology. A 400 mg dose of moxifloxacin was administered once daily for 7 days to 242 patients and 250 mg twice daily of cefuroxime axetil was administered to 251 patients for 10 days. The clinical success rate at the end of treatment in the evaluable population was significantly higher (96.7%) in the moxifloxacin group (204/211) than in the cefuroxime axetil group (204/225, 90.7%; 95% confidence intervals 1.5%; 10.6%). At follow-up the success rate in the moxifloxacin group was 90.7% and that for the cefuroxime axetil group was 89.2% (95% confidence intervals -4.3%; 5.4%). The predominant pathogens isolated were Streptococcus pneumoniae and Haemophilus influenzae, followed by Moraxella catarrhalis and Staphylococcus aureus. The bacteriological eradication rates were higher for moxifloxacin (94.5%, 103/109) than for cefuroxime axetil (83.5%, 96/115; 95% CI 3.6%; 19.7%). Only one S. pneumoniae infection persisted following moxifloxacin therapy in contrast with three in individuals on cefuroxime axetil. There were slightly more adverse events in the moxifloxacin group than in the cefuroxime axetil group, but there were fewer serious adverse events following moxifloxacin treatment (three vs. eight). The drug was discontinued because of adverse events in 14 moxifloxacin patients and in 11 cefuroxime axetil patients. Overall, in all assessments, moxifloxacin was at least as effective clinically and bacteriologically, and as well tolerated, as cefuroxime axetil in the treatment of acute sinusitis.

Acute Disease↗
PubMed2000

[Water-jet dissection in parotid surgery--initial clinical results].

INTRODUCTION: The most frequent complication following parotidectomies is postoperative facial nerve dysfunction. In animal experiment we successfully studied the technique of water-jet-dissection for safe and functional preservation in facial nerve dissection in parotid gland surgery. The aim of the present study was to evaluate our animal experiments clinically. METHODS: Until November '99 ten patients with benign parotid gland tumors (4 female, 6 male, age 32-77 years) underwent lateral or latero-segmental parotidectomies using water-jet-dissection ("Hydro-Jet", Andreas Pein Medizintechnik GmbH, Schwerin, Germany). All operations were performed under permanent intraoperative facial nerve monitoring ("Neurosign 100", Fa. Inomed, Tenningen, Germany). The postoperative facial nerve function was measured daily by the House-Brackmann and Stennert-Paresis-Index for at least one week. RESULTS: A quick parotid gland and safe facial nerve dissection could be performed in all operations using the 120 microns-nozzle with effective working pressures from 30-50 bar. In addition strong connective tissue fibers were transected with scissors. Intraoperative facial nerve lesions did not occur and cardiopulmonary complications due to eventual cutting-fluid-resorption were not seen. After surgery all patients had a normal facial nerve function. DISCUSSION: The results of our studies showed that the technique of water-jet-dissection provides safe facial nerve dissection and preservation during parotid gland surgery. CONCLUSIONS: The tissue selective cutting qualities of the new surgical method are an excellent alternative compared to standard dissection methods in parotid surgery.

Adult↗
PubMed1998

Lipid patches in membrane protein oligomers: crystal structure of the bacteriorhodopsin-lipid complex.

Heterogenous nucleation on small molecule crystals causes a monoclinic crystal form of bacteriorhodopsin (BR) in which trimers of this membrane protein pack differently than in native purple membranes. Analysis of single crystals by nano-electrospray ionization-mass spectrometry demonstrated a preservation of the purple membrane lipid composition in these BR crystals. The 2.9-A x-ray structure shows a lipid-mediated stabilization of BR trimers where the glycolipid S-TGA-1 binds into the central compartment of BR trimers. The BR trimer/lipid complex provides an example of local membrane thinning as the lipid head-group boundary of the central lipid patch is shifted by 5 A toward the membrane center. Nonbiased electron density maps reveal structural differences to previously reported BR structures, especially for the cytosolic EF loop and the proton exit pathway. The terminal proton release complex now comprises an E194-E204 dyad as a diffuse proton buffer.

Journal Article↗
PubMed1998

Dermal microvasculature and tissue selective thinning techniques (ultrasound and water-jet) of short-time expanded skin in dogs.

Certain reconstructive procedures, like auricular reconstructions, require thin and well-vascularized skin. The aims of this study were to analyze if the increased survival of expanded skin flaps was due to morphologic changes of the dermis, if thinning of short-time expanded skin was possible without harm to the microcirculation and if tissue selective cutting methods could be used to resect subcutaneous fat without damaging its vessels. Eighty-two 200-ml expanders were implanted into the trunk regions of 26 beagles and filled immediately with sterile saline. In the first series of experiments, the expansion was terminated after intervals of 0.5-5 weeks and dermal vessels were analyzed morphometrically. In the second series the expanded flaps were raised after 2 weeks and thinned solely surgically or with the additional use of an ultrasonic knife or with cutting by water jet. In contrast to sham flaps, the expanded skin showed only very few areas of necrosis and these were located superficially in most cases. The relative volume of the dermal vessels and their quantity showed a significant increase after the expansion. Additionally, the subcutaneous tissue could be thinned down to 0.4 mm with the water-jet-cutter. Findings demonstrated that the method used could create a well-vascularized skin flap of minimal thickness that could be very helpful for special reconstructive procedures.

Adipose Tissue↗
PubMed1998

The effect of tissue expansion on the expression of collagen type I and type III mRNA in distinct areas of skin in the dog as an animal model.

To evaluate the transcriptional response of skin to tissue expansion in the dog, the expression of procollagen alpha 1(I) mRNA and procollagen alpha 1(III) mRNA were analyzed by in situ hybridization. This expression was evaluated in distinct skin areas (subepidermal zone, dermis, capsular zone) after 4-85 days of expansion. Within the first 4 days of expansion expression of procollagen alpha 1(I) and alpha 1(III) mRNA was not affected in the subepidermal and dermal zone. Only a slightly elevated level of type III procollagen mRNA was demonstrated in tissue surrounding the implanted silicone expander. After 7 days of expansion an enhanced level of procollagen alpha 1(III) mRNA was observed in the dermis and capsular zone. A slightly enhanced type I collagen mRNA level occurred in all zones of the dermis that was even stronger in the capsular zone after 9 days of expansion. Concurrently, the number of transcriptionally active cells was significantly higher. Return to the basal level of procollagen alpha 1(I) mRNA was attained after 40 days. At this time a significant expression of procollagenase mRNA was observed. Procollagen III mRNA expression reached its basal level on day 85.

Animals↗