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Biomedical subjects

R Schnettler

Publications and source records attributed to R Schnettler.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Osteochondral transplantation versus autogenous chondrocyte transplantation. A prospective comparative clinical study].

INTRODUCTION: The treatment of full-thickness cartilage defects still represents a problem that has not yet been solved satisfactorily. Current methods used to cover defects in the knee joint are osteochondral cylinder transplantation (OCT) and autologous chondrocyte transplantation (ACT). METHODS: With a prospective clinical investigation, at the time being with 2-year results, we have examined ACT in comparison to OCT in 20 patients with regard to clinical and histomorphological (histology, immunohistochemistry, RES) outcome. RESULTS: We found equally good results with both methods in Lysholm, Meyers and Tegner Activity Scores. Histomorphologic evaluation of biopsies obtained by arthroscopy after ACT showed a defect filling in all cases, mainly with fibrous cartilage, while localized areas of hyalinelike regenerative cartilage were documented near the base. We did not see any histomorphologically visible change in the transplants after OCT. CONCLUSION: At the time we prefer OCT instead of ACT given the correct indication.

Adolescent↗
PubMed1998

[Defect reconstruction using demineralized bone matrix. Experimental studies on piglets].

The aim of this study was to evaluate the bone stimulation forced by Demineralized Bone Matrix (DBM)-Chips and-Gel in comparison to the bone-ingrowth into a porous hydroxylapatite ceramic (Endobon) in mini pigs. The following results were obtained: 1. DBM-Chips and DBM-Gel did not stimulate bone healing when filled into cancellous bone defects. The defect did not heal within 12 weeks. 2. Up to 35 days the least amount of new bone formation was observed within porous hydroxylapatite ceramic. Up to 12 weeks complete bone ingrowth in to the ceramic has been seen with close bonding between new formed bone and the ceramic trabeculae. 3. By continuous labelling with fluorochromes the new bone formation could be analysed by fluorescence microscopy and the dynamics could be related to time after implantation.

Animals↗
PubMed1997

[Is ambulatory surgery at a maximum care clinic justified?].

It is politically desirable to promote ambulatory surgery in private practice or in hospitals as a means to reduce costs. In contrast to this, one has to deal with unsatisfactory net profits. Even if a hospital is primarily running at a loss, ambulatory surgery should be performed. Offering the service of ambulatory surgery can improve the recruitment of patients and may help to compete with other hospitals.

Ambulatory Surgical Procedures↗
PubMed1996

[Gunshot wounds--ballistics, physiopathology, surgical treatment].

The form and size of gunshot wounds depend on the projectile type (bird shot, deforming projectiles, non-deforming projectiles), its velocity at impact (high or low velocity projectiles) and the type of tissue affected by the projectile (soft tissues, bones). Gunshot wounds are always contaminated. While low velocity projectiles usually cause minimal wounds, high velocity projectiles can cause large, devastating wounds. All projectiles fired from firearms have a high velocity on impact and may cause death by traumatic shock instantaneously. Ballistics, pathophysiology and clinical findings of gunshot wounds are discussed, forensic aspects are mentioned. Gunshot wounds are often emergencies. Lifesaving and -stabilizing treatment is most important. A treatment plan aiming at preventing possible complications such as infections and functional disturbances is given for different types of gunshot wounds. Systemic lead poisoning has not been investigated sufficiently. Projectiles usually become encapsulated. The search for projectiles is associated with an additional surgical trauma and usually indicated only for joint wounds (lead arthropathy).

Animals↗
PubMed1992

Stably inherited killer activity in industrial yeast strains obtained by electrotransformation.

Killer-sensitive strains of Saccharomyces cerevisiae and Saccharomyces carlsbergensis were transformed by electroinjection using double-stranded RNA isolated from a superkiller strain. Various recipient strains were used: both thermo-resistant and thermo-sensitive as well as mutants of industrial strains. Conversion of respiratory competent (rho+) into respiratory deficient (rho-) strains (mutants) resulted in a significant increase of the yield of electrotransformants and/or of longterm killer stability. Electrotransformation of rho- mutants of distillery and brewery strains resulted in more than 100 clones, which exhibited weak or strong killer activity over some or all of the experimental period of 10 months.

DNA, Mitochondrial↗
PubMed1992

Alginate coating of islets of Langerhans: in vitro studies on a new method for microencapsulation for immuno-isolated transplantation.

Immuno-isolated transplantation offers the attractive prospect of being able to transplant xenogeneic islets without immunosuppression. This study introduces a completely new method of coating single islets using a homogeneous alginate membrane approximately 10 microns thick. During glucose challenge (perifusion and static incubation) encapsulated islets show the same pattern and quantity of insulin release as non-encapsulated controls. This encapsulation method markedly reduces the amount of transplanted material by reducing the size of the capsule. It is suggested that encapsulated islets may be transplanted into sites such as the renal capsule or omentum or even by intraportal injection into the liver.

Alginates↗
PubMed1992

[Monteggia injuries in athletes. Causes, classification, results].

Monteggia-fractures are serious combination injuries to the forearm. Sport injuries are being increasingly observed; the reason for this, besides the general expansion of mass sports, is the increasing burden of high-performance sports. Monteggia fractures can occur during a fall on an outstretched arm, for example in motor or bicycle sport injuries, but also when falling from gymnastic equipment. Generally, it is easy to diagnose the monteggia injury. Considerable secondary damage could occur from the frequent failure to notice the involved radiohumeral joint. It should be demanded that in case of an uluar fracture the adjoining joints should be x-rayed on two planes in order not to overlook the possibility of a chisel fracture. The different forms of this combination injury, its classification and the results of our own medical bulletins are presented.

Athletic Injuries↗
PubMed1992

[Arthrodesis of the upper ankle joint. Indications, technique, results].

From 1984 to 1990 a total of 119 arthrodesis of the upper ankle joint were performed at the Hospital of Accident Surgery of the Trade Association in Frankfurt am Main. The results of 98 patients after an arthrodesis of the upper ankle joint are documented by an x-ray control series and patient files, including the expertise on the medical status of pensioners plus a follow-up examination of 34 patients. The indications and the results are discussed on the basis of the various procedures. The results confirm the method of a compressions arthrodesis with an extension screw in case of a posttraumatic arthrosis of the upper ankle joint, while a fixateur externe should be used in case of chronical osteomyelitis, osteoporotic bones, extensive tissue swellings and after a pilon or talus fragment fracture.

Ankle Injuries↗
PubMed1992

The use of gentamicin-PMMA chains in the treatment of infected tibial nonunion.

Local antibiotic therapy with gentamicin-PMMA chains and external fixation permit effective simultaneous therapy of both components of infected tibial pseudarthroses: sequestering osteomyelitis and pseudarthrosis. The local concentrations of gentamicin which can be achieved by implantation of gentamicin-PMMA chains are far above the MIC of most common pathogens. This form of local antibiotic therapy is superior to any form of systemic antibiotic therapy. The gentamicin-PMMA chains serve as well as space holders for the bone graft to promote bone consolidation in the absence of infection. The results can be improved by successful management of the soft tissue damage often associated with tibial pseudarthrosis. Pedicled or free muscle graft with microvascular anastomosis is the method of choice.

Drug Therapy, Combination↗
PubMed1990

Efficient hybridization of mouse-human cell lines by means of hypo-osmolar electrofusion.

The fusion of a mouse-human heteromyeloma with a mouse hybridoma is used as a model to define parameters to generate human hybridomas. Electrofusion of these cells in 300 mosM and 75 mosM solutions showed that strong hypo-osmolar conditions resulted in a dramatic increase in the efficiency of hybridoma formation. In contrast to iso-osmolar electrofusion, a high hybrid yield could be obtained by injection of only a single field pulse. The field strength was adjusted in proportion to the increased size of the cells in hypo-osmolar solutions. Hypo-osmolar electrofusion allowed the generation of approximately 0.45% hybrids at a suspension density of 1.75 X 10(5) mouse-human cells/ml corresponding to an input number of 3.5 X 10(4) mouse-human cells. A further increase in the efficiency of hybridoma formation to about 0.6% was achieved by cell alignment in an alternating field of modulated field strength. Experiments in which the total cell number per fusion chamber was decreased at constant optimum suspension density showed that a further increase in the efficiency of hybridoma formation in hypo-osmolar solution was not possible because of the increasing influence of the heterogeneity of the cell lines with decreasing cell number. The results allow the conclusion that hypo-osmolar electrofusion is a potential tool to enhance successful immortalisation of human B lymphocytes.

Animals↗
PubMed1990

Transmission of killer activity into laboratory and industrial strains of Saccharomyces cerevisiae by electroinjection.

The killer character was electrically introduced into protoplasts of three yeast strains. These were the killer-negative variant of the K1 killer strain Saccharomyces cerevisiae T 158 C (his-); the killer-sensitive laboratory strain S. cerevisiae AH 215 (leu-, his-); and the killer-sensitive industrial strain S. cerevisiae AS 4/H2 (rho-). The killer dsRNA used for electroinjection was isolated from the super-killer strain S. cerevisiae T 158 C. Optimum numbers of transformed cells were obtained after regeneration and selection in appropriate media if the protoplasts were exposed to three exponentially decaying field pulses of 18.2 kV/cm strength and 40 microseconds duration at 4 degrees C. In the case of the killer-negative variant of S. cerevisiae T 158 C the majority of the protoplasts were transformed, whereas in the case of the two other strains the yield of transformed clones was much less. This latter result is expected if the expression of the electroinjected dsRNA was diminished in these two strains. Gel electrophoresis of the dsRNA of the clones of the three strains supported the conclusion that the transformed clones exhibited killer activity. The transformed clones of all three species were stable.

Electrochemistry↗
PubMed1990

[Results of interlocking nailing of distal tibial fractures].

Between 1982 and 1989, 117 fractures of the distal part of the lower leg were surgically treated in the Trauma Clinic belonging to the employers' liability insurance company in Frankfurt/Main. A follow-up examination of 85 of these patients, based on X-ray series, clinical reports, and insurance files, shows the functional results. Because of the high proportion of good to excellent results (95.4%), we consider fracture of the distal tibia a good indication for interlocking nailing, even from the aspect of the borderline indication of fracture in the fifth sixth. In open fractures of the distal part of the lower leg we consider the change of method from primary stabilization with external fixation to secondary interlocking nailing an appropriate procedure. The methods presented for internal fixation of fractures of the distal tibia by interlocking nailing allow early partial and full weight-bearing with the stability needed for exercising.

Adult↗
PubMedDate not supplied

[Vacuum mixing systems for bone cement completion - comparison of different systems].

INTRODUCTION: The use of vacuum mixing systems when mixing bone cement reduces its porosity and hereby significantly improves the features of the material. The currently available mixing systems are compared with regard to handling, mechanical properties and economical aspects. METHODS: In 8 vacuum mixing systems the handling, pump performance, system tightness, the used air volume, the filter efficiency, the remaining amounts in the mixing system and the porosity of the cements are shown in comparison. RESULTS: All vacuum mixing systems reduce the porosity of the cement in comparison to hand mixed cements significantly if used correctly. The individual examinations, though, show enormous differences, which can be of significance to the user in the individual choice of system and, depending on the individual circumstances, can influence the quality of the mixed cement. CONCLUSION: The results enable the user to choose and handle a vacuum mixing system which is optimally suitable for the individual circumstances in respect to the characteristics examined.

Arthroplasty, Replacement↗
PubMedDate not supplied

[Health-economic considerations for the use of BMP-2 for spinal surgery in Germany].

INTRODUCTION: BMP-2 can replace autogenous bone grafting in lumbar one-level anterior lumbar interbody fusions (ALIF). The current G-DRG system does not reimburse the upfront price of 2,970 euro per BMP-2 application for hospitals in Germany. The purpose of the current study was to create a health economic model to evaluate the financial savings for health care providers (hospitals) and health care payers (health care insurance) that can be achieved by the use of BMP-2 in spine surgery. METHODS: A previously published pooled data analysis was used in which BMP-2 showed significant improvements in the treatment after ALIF surgery compared to autogenous bone grafting, including earlier return to work time and reduced revision rates. These medical findings were transformed into economic data based on the regulations of the German health system of 2005. RESULTS: The significantly shorter return to work time under BMP-2 treatment generates important financial savings for health care insurances offsetting the upfront prize of 2,970 euro for BMP-2. Savings for hospitals are mainly related to shorter surgery time due to the absence of the bone grafting procedure and faster discharge of the patient. CONCLUSIONS: The combination of improved medical outcome by BMP-2 treatment for the patient and net savings for the entire health care system in Germany represents a "dominant" strategy from a health economic perspective. This implicates that BMP-2 in ALIF procedures is to be recommended from a health economic point of view for the German health care system.

Bone Morphogenetic Protein 2↗