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Biomedical subjects

M Haake

Publications and source records attributed to M Haake.

36 records · Page 2Linked to original sources
PubMed2000

[Extracorporeal shockwave therapy in treatment of epicondylitis humeri radialis. A current overview].

In the past, extracorporeal shock-wave therapy (ESWT) has been used increasingly as a treatment for conservatively unsuccessfully treated radiohumeral epicondylitis. However, published reviews of clinical trials on the efficacy of ESWT have led to inconsistent results and are outdated or methodologically inadequate. As a consequence, a systematic literature search was conducted which yielded 20 relevant papers that described trials on the efficacy of ESWT in the treatment of radiohumeral epicondylitis. These were rated according to biometrical criteria for the conduct of therapeutic trials. None of the rated trials fulfilled all of the criteria, and it is concluded that the efficacy of ESWT in the treatment of epidondylitis can presently be neither confirmed nor excluded.

Follow-Up Studies↗
PubMed1999

Gas flow MRI using circulating laser-polarized 129Xe.

We describe an experimental approach that combines multidimensional NMR experiments with a steadily renewed source of laser-polarized 129Xe. Using a continuous flow system to circulate the gas mixture, gas phase NMR signals of laser-polarized 129Xe can be observed with an enhancement of three to four orders of magnitude compared to the equilibrium 129Xe NMR signal. Due to the fact that the gas flow recovers the nonequilibrium 129Xe nuclear spin polarization in 0.2 to 4 s, signal accumulation on the time scale of seconds is feasible, allowing previously inaccessible phase cycling and signal manipulation. Several possible applications of MRI of laser-polarized 129Xe under continuous flow conditions are presented here. The spin density images of capillary tubes demonstrate the feasibility of imaging under continuous flow. Dynamic displacement profiles, measured by a pulsed gradient spin echo experiment, show entry flow properties of the gas passing through a constriction under laminar flow conditions. Further, dynamic displacement profiles of 129Xe, flowing through polyurethane foams with different densities and pore sizes, are presented.

Equipment Design↗
PubMed1999

Xenon-131 surface sensitive imaging of aerogels in liquid xenon near the critical point.

In recent years, optically pumped xenon-129 has received a great deal of attention as a contrast agent in gas-phase imaging. This report is about the other NMR active xenon isotope (i.e., xenon-131, S = 32) which exhibits distinctive features for imaging applications in material sciences that are not obtainable from xenon-129 (S = (1/2)). The spin dynamics of xenon-131 in gas and liquid phases is largely determined by quadrupolar interactions which depend strongly on the surface of the surrounding materials. This leads to a surface dependent dispersion of relaxation rates, which can be substantial for this isotope. The dephasing of the coherence due to quadrupolar interactions may be used to yield surface specific contrast for imaging. Although optical pumping is not practical for this isotope because of its fast quadrupolar relaxation, a high spin density of liquid xenon close to the critical point (289 K) overcomes the sensitivity problems of xenon-131. We report the first xenon-131 magnetic resonance images and have tested this technique on various meso-porous aerogels as host structures. Aerogels of different densities and changing levels of hydration can clearly be distinguished from the images obtained.

Gels↗
PubMed1999

[Effects of extracorporeal shock waves (ESW) on human bone marrow cell cultures].

INTRODUCTION: Extracorporeal shockwave therapy (ESWT) is a new method of treating insertion tendopathy and pseudo-arthrosis, the clinical importance of which cannot yet be definitively assessed, and the underlying mechanisms of which are still unclear. AIM: To develop an experimental set-up enabling the standardised application of ESWT to human bone marrow cell culture and the determination of the effect of ESWT. MATERIAL AND METHODS: After 14 days incubation, human bone marrow cell cultures were subjected to ESWT using 200/500 pulses at an energy flux densities ED + of 0.03, 0.04, 0.07, 0.11 and 0.25 millijoule/mm2. Samples were obtained for LDH measurement 15 minutes, 4 h and 18 h after ESWT. Transmission light microscopy was carried out before and after ESWT to determine cell numbers and for morphological analysis. RESULTS: Gaps in the cellular tissue first appear at an energy of 0.01 millijoule/mm2. At energies of 0.25 millijoule/mm2, morphologically altered cells, thinned out cellular tissue with a cell-free focal zone are found. At low energy levels, defects have been repaired ca. 1 week after ESWT. No significant increase in LDH was detected at any of the energy levels applied. CONCLUSION: Increasing energy and higher pulse frequency is associated with an increase in the size and number of holes in cellular tissue and in cell separation. Regeneration capability (regrowth, sprouting, normal cell form) decreases as the energy level increases. Changes can be detected even at the lowest energy flux densities, which up until now had been assumed to have no effect on cell morphology or number. The standardised application of ESWT to human bone marrow cell cultures provides reproducible results that can be controlled by a placebo ESWT application.

Bone Marrow Cells↗
PubMed1998

Multinuclear NMR study of enzyme hydration in an organic solvent.

Multinuclear NMR spectroscopy has been used to study water bound to subtilisin Carlsberg suspended in tetrahydrofuran (THF), with the water itself employed as a probe of the hydration layer's physicochemical and dynamic characteristics. The presence of the enzyme did not affect the intensity, chemical shift or linewidth of water (up to 8% v/v) added to THF, as measured by 17O- and 2H-NMR. This finding suggests that hydration of subtilisin can be described by a three-state model that includes tightly bound, loosely bound, and free water. Solid-state 2H-NMR spectra of enzyme-bound D2O support the existence of a non-exchanging population of tightly bound water. An important implication is that the loosely-bound water is the same as free water from an NMR viewpoint. This loosely bound water must also be the water responsible for the large increase in catalytic activity observed in previous hydration studies.

Deuterium↗
PubMed1998

Surface NMR Using Laser-Polarized 129Xe under Magic Angle Spinning Conditions

NMR signals of surface nuclei of solids may be enhanced by the transfer of spin polarization from laser-polarized noble gases. Until now such experiments have not been feasible under conditions of magic angle spinning. In the present contribution it is shown that laser-polarized 129Xe can be inserted into a spinning rotor under continuous-flow conditions using helium as a carrier gas. Effective adsorption of xenon on the sample occurs at temperatures of about 163-173 K making possible the observation of a spin polarization induced nuclear Overhauser effect (SPINOE) from the laser-polarized 129Xe to surface 1H nuclei of SiO2 (AEROSIL300). This technique opens the way to selectively enhanced high-resolution multinuclear surface NMR experiments. Copyright 1998 Academic Press. Copyright 1998 Academic Press

Journal Article↗
PubMed1996

Standardized evaluation of long-term results after anterior lumbar interbody fusion.

A total of 113 patients, excluding those with tumor, spondylitis, and idiopathic scoliosis, underwent anterior lumbar interbody fusion (ALIF) with autologous iliac crest graft between 1984 and 1991 at our department. The proportion of these who were failed back patients was higher than that reported in the literature. Evaluation of functional outcome was feasible in 80 patients, utilizing Oswestry and Marburg scores, which were closely intercorrelated. The overall results yielded an improvement in the Oswestry score of 35.7 percentage points. A subset of 52 patients who were evaluated twice, showed the same results at an average of 6.6 years as they did at 2.3 years following surgery. Functional results showed a weak correlation with postoperative height loss of the intervertebral space. Influencing factors for the functional result were: postoperative compensation claim, age, and obesity. Of the professional people involved, 19.4% did not return to any occupation. Patients satisfied with the result had significantly greater functional improvement. Younger patients with additional dorsal distraction prior to ALIF for reduction of severe spondylolisthesis fared better than patients with ALIF alone. The rate of complications was low and did not contribute to the postoperative functional result. On the basis of these results further prospective studies have been designed and are currently underway.

Adolescent↗
PubMed1995

False-positive sonographic hip examinations in newborns with congenital varus deformity of the proximal femur.

In cases of congenital varus deformity of the proximal femur, the screening of hip dysplasia can lead to misinterpretations. The false-positive ultrasound result is caused by the superiorly displaced greater trochanter in hips with coxa vara, which narrows the scan window. In this paper three typical patients are presented to demonstrate that the use of additional non-standard views cannot exclude hip dysplasia in all cases. Hence, such patients with femoral abnormalities and doubtful sonographic findings should be further evaluated by arthrography or magnetic resonance imaging to rule out additional hip dysplasia.

False Positive Reactions↗
PubMed1989

Micromotions in the primary fixation of cementless femoral stem prostheses.

Thirty cementless femoral stems of six different types of hip endoprostheses were implanted in femurs taken at autopsy and underwent static loading and afterwards dynamic loading of 50,000 cycles to simulate walking during the early months after implantation. After that, the static load tests were performed again. During both static load series a certain amount of micromotion between stem and implantation bed occurred in the frontal and sagittal planes and also during rotation. The six prostheses exhibited clearly differing results. The influence of dynamic load on the extent of micromotion was small.

Bone Cements↗
PubMedDate not supplied

[Design of a multicenter study for assessing the effectiveness of extracorporeal shockwave therapy in epicondylitis humeri radialis].

INTRODUCTION: Previously published studies concerning, extracorporeal shock-wave therapy (ESWT) in the treatment of lateral epicondylitis do not fulfil the biometric standards of modern clinical research. The objective of the trial is to show that ESWT is effective in the treatment of chronic LE. METHOD: A prospective, randomized, placebo-controlled, single-blinded, multicenter trial with an independent blinded observer was designed. The effectiveness of ESWT is evaluated by comparison with a control group in which sham-ESWT is performed, both under local anaesthesia. Outcome is determined on the basis of the Roles/Maudsley-Score. Inclusion criteria are a history of at least 6 months of LE and failure of conventional treatment. The therapy includes 3 sessions of low energy ESWT with 2000 impulses (energy flux density 0.07-0.09 mJ/mm2). Sample size is 272 patients. STATUS: Randomisation started in October 1998 and is planned over a period of two and a half years. CONCLUSION: Only a randomised clinical trial with adequate control of placebo effects and observer bias can provide the required evidence for the efficiency of ESWT in the treatment of lateral epicondylitis of the elbow.

Adult↗
PubMedDate not supplied

[Comparison of extracorporeal shockwave therapy (ESWT) with roentgen irradiation in supraspinatus tendon syndrome--a prospective randomized single-blind parallel group comparison].

AIM: Extracorporal shock wave therapy (FSWT) is applied in the case of supraspinatus tendinitis if conservative therapies have failed. So far there has been no controlled study comparing the effectiveness of ESWT with an established conservative method of therapy such as X-ray stimulation radiotherapy. METHOD: Thirty patients with chronic supraspinatus tendinitis were admitted into the prospective randomised study. After randomisation, the patients were treated either three times with 2000 pulses (energy flux density ED+ 0.33 mJ/mm2) with a Storz Minilith SL1 after one week, or with X-ray stimulation radiotherapy with 6 x 0.5 Gy on the ICRU reference point (1 neutral fraction/day) with cobalt 60 gamma rays. Primary endpoint was the age-corrected constant score. RESULTS: In the ESWT group the average age-corrected constant score rose from 50.1 points before ESWT to 91.5 points after 12 weeks and to 97.8 after 52 weeks. In the radiotherapy group it improved from 47.6 through 79.5 points to 87.4 points. CONCLUSION: No statistically significant differences were proven between ESWT and radiotherapy. ESWT appears to be at least equivalent to radiotherapy in treating chronic supraspinatus tendinitis syndrome and can avoid a dose of radiation for patients and staff. A comprehensive randomised study is, however necessary to ensure the equivalence of ESWT.

Adult↗
PubMedDate not supplied

[Musculoskeletal shock wave therapy--current database of clinical research].

During the past decade application of extracorporal shock waves became an established procedure for the treatment of various musculoskeletal diseases in Germany. Up to now the positive results of prospective randomised controlled trials have been published for the treatment of plantar fasciitis, lateral elbow epicondylitis (tennis elbow), and of calcifying tendinitis of the rotator cuff. Most recently, contradicting results of prospective randomised placebo-controlled trials with adequate sample size calculation have been reported. The goal of this review is to present information about the current clinical database on extracorporeal shock wave treatment (ESWT).

Calcinosis↗
PubMedDate not supplied

[Experimental studies of the effect of surgical technical errors on primary stability of cementless hip endoprosthesis shafts].

For quantified evaluation of the primary stability of cementless femoral stem prostheses the operative faults: too low sized stem, distally short-lined anchoring with proximally surpassing stem and fissure or fracture of the femur shaft were simulated in autoptical test series. By inductive displacement transducers the micromotion between stem and proximal bone layer were measured in medio-lateral and ventro-dorsal direction under static load conditions before and after a dynamic loading of 50,000 cycles. The underdimensioned stem showed its instable anchoring by obviously increased micromotions in all measure plains. The proximally excelling only distally anchored prosthesis demonstrated immense amounts of motion. The fissure doesn't seem to decrease the primary stability of the stems too much. These results of the autoptical test series can only be directly transferred to the conditions of the first weeks after implantation, because the influence of later bone integration could not be considered.

Biomechanical Phenomena↗
PubMedDate not supplied

[Magnetic resonance tomography in diagnosis and therapy follow-up of patients with congenital hip dysplasia and hip dislocation].

AIM: In patients with congenital dislocation of the hip the assessment of the correct position of the hip joint after closed or open reduction is very difficult to make from the radiograph with the hips in plaster. As the delayed recognition of a recurrent hip dislocation has bad effects on the outcome of the affected hip a safe and reliable imaging method must be employed. METHOD: From 1993 to 1996 6 patients with 8 congenital dislocations of the hip joint were examined by magnetic resonance imaging for evaluation of the position of the hip in plaster after reduction. Magnetic resonance imaging was performed immediately after closed or open reduction. 3 hips had to be treated by open surgery. RESULTS: The investigation confirmed that magnetic resonance imaging allows perfect differentiation between the bony and cartilaginous parts of the hip joint in plaster as well. Interpositioning of soft tissues which prevent reduction could also be visualized clearly. The best sequence in order to differentiate bony from cartilaginous structures was a gradient echo sequence in flash-technique using a flip-angle of 60 degrees. In all cases the correct position of the hip joint after reduction could be demonstrated in plaster. CONCLUSION: Therefore, magnetic resonance imaging is the imaging method of choice for confirmation and documentation of the reduced position of the hip joint in plaster. Radiographs are no longer needed.

Cartilage, Articular↗