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H Schmitt

Publications and source records attributed to H Schmitt.

At least 19 recordsLinked to original sources
PubMed2006

[Is competitive running associated with osteoarthritis of the hip or the knee?].

BACKGROUND: The aim of the study was to find what degenerative changes were present in the hip and knee joints of former elite marathon runners and how these subjects' joints differ from those of control persons. METHODS: Twenty former elite German marathon runners (active careers 1972-86) underwent clinical (FFbH-OA [hip joint] and AKSS [knee joint]) and radiographic (hip and knee joints, Kellgren and Lawrence classification) examination. X-Rays of the hip joints were compared with those of controls matched for age, gender and BMI who did not engage in much sport. RESULTS: In the group of former elite marathon runners, 3 of the 38 knee joints for which comparison with control joints was possible were found to be affected by grade 2 osteoarthritis. In the same group, severe osteoarthritis (Kellgren and Lawrence grade 3) was documented in 1 and moderate osteoarthritis (grade 2) in 6 of the 28 hips for which direct comparison against the controls was possible, as against 1 hip affected by grade 2 osteoarthritis in the entire control group. The clinical evaluation showed high scores in all athletes. CONCLUSIONS: Osteoarthritis of the knee joint is rare in former elite marathon runners. The risk of osteoarthritis of the hip joint seems to be higher than in control subjects who do not engage in much sport.

Adult↗
PubMed2006

Stress fractures in the juvenile skeletal system.

Stress fractures affecting the juvenile skeletal system are rare and are described as having a good prognosis. Precisely because these fractures are so rare, studies allowing clear and generally applicable conclusions are lacking. The object of the present study was a systematic analysis of patients with stress fractures in an immature skeletal system, with special reference to the frequently difficult and delayed diagnosis and to the forms of therapy considered appropriate. Twenty-five patients with a total of 27 stress fractures affecting bones with the growth plates still open were examined according to a standardized procedure. The average duration of follow-up was 4.8 years (SD +/- 2.3) and the average age at occurrence 12.9 years (SD +/- 4.31). The risk factors were largely the same as those in adults. The most frequent site was the tibia (48% of cases; n = 13), followed by the metatarsal bones. Most (26/27) fractures were treated conservatively, with an average duration of therapy of 8.9 weeks (SD 8.2 weeks). Ultimately, 17 (63%) of the fractures healed in such a way as to allow the patients to return to full athletic activity with no restrictions within 3 months after diagnosis. In 9 cases (33%) it was not possible to achieve complete absence of symptoms within 12 months after diagnosis was made. No pseudarthroses were observed. There was a significant correlation between clinical outcome recorded as "free of symptoms" and an early diagnosis (less than 2 weeks after first symptoms (p = 0.033) and a fracture line seen on MR tomography in contrast to a stress reaction with merely increased signal intensity (p = 0.037). Overall, a strikingly high proportion of these patients had a prolonged course. This is attributable partly to the delay in diagnosis and to inappropriate initial treatment. When stress fractures were recognizable by a demonstrable fracture line--in contrast to just an edema--on MR tomography and their diagnosis was followed by an adequate form of therapy the chances of complete healing seemed to be better. It is essential to carry out targeted imaging investigations, e.g., by means of MR tomography, when there is a reason to consider a stress reaction. Furthermore, stress fractures should be adequately treated until all symptoms have disappeared.

Adolescent↗
PubMed2006

Sports injuries: population based representative data on incidence, diagnosis, sequelae, and high risk groups.

OBJECTIVE: To generate national representative data on the incidence, diagnosis, severity, and nature of medically treated sports injuries and to identify high risk groups. METHODS: The first national health survey for the Federal Republic of Germany, conducted in the format of a standardised, written, cross sectional survey in the period October 1997 to March 1999, gathered data on the incidence of accident and injury and information on social demographics, injury related disability/time off work, and injury location/setting. The net sample comprised 7124 people aged 18-79. RESULTS: 3.1% of adult Germans said they sustained a sports injury during the previous year, corresponding to an annual injury rate of 5.6% among those engaging in regular recreational physical activity and ranking sports injuries as the second most common type of accident. About 62% of all sports injuries result in time taken off work. The period of occupational disability is 14 days or less in around two thirds of these cases. The occupational disability rate after occupational and traffic accidents is much higher by comparison. Dislocations, distortions, and/or torn ligaments make up 60% of all sports injuries, followed by fractures (18%), contusions, surface wounds, or open wounds (12%). Three out of four sports injury casualties are male. The incidence declines noticeably in higher age groups. CONCLUSIONS: Future injury prevention measures should focus on the high risk group of young male recreational athletes. The data indicate that the fear of damage to health and injury, believed to be significant internal psychological barriers to participation in sports, is largely unwarranted for the female population and/or older age groups. Sporting injuries are a marginal phenomenon among the female population and mobile seniors actively engaged in sports.

Adult↗
PubMed2005

[Prevalence and correlates of osteoarthritis in Germany. Representative data from the First National Health Survey].

BACKGROUND: The purpose of the paper was to generate up-to-date, representative osteoarthritis prevalence data for individual population subgroups and to identify potential risk factors. MATERIAL AND METHODS: A cross-sectional study, the "First National Health Survey", investigated the prevalence of osteoarthritis, comorbidity and health-relevant behaviours of the post-unification German population on the basis of interviews with physicians and medical evaluations conducted in the period from October 1997 to March 1990. The study was based on a net sample comprising 6205 subjects aged 18-79 years. RESULTS: The three main correlates for osteoarthritis are age, obesity and occupational stress factors. Osteoarthritis patients are more likely to have osteoporosis, thyroid disease, chronic bronchial disease, hypertension and elevated blood lipids, but do not tend to have a higher incidence of diabetes. CONCLUSION: Our data show the importance of preventive behavioural approaches such as weight management and workplaces designed to limit joint overuse.

Adolescent↗
PubMed2004

Heart rate variability in patients suffering from structural heart disease and decreased AV-nodal conduction capacity. Insights into the formation of heart rate variability.

METHODS: Time and frequency domain analysis were conducted during a period of 600 s each. We performed a special protocol consisting of five different "pacing" periods: 1) recording of normal sinus rhythm (SR1); 2) atrial pacing with a rate 15% higher than the intrinsic heart rate; 3) ventricular pacing triggered by atrial activation (VAT, with a short AV-delay of 80 ms); 4) AV-sequential pacing with an atrial rate 15% higher than the intrinsic heart rate and a very short AV delay of 80 ms (DDD); 5) normal sinus rhythm (SR2). Only patients with normal AV-nodal conduction or with AV-block I degrees were included. The influence of a structural heart disease as well as a non-sustained VT on Holter ECG and a depressed EF on HRV parameters were analyzed using a multivariate analysis. All patients were lying in a supine position. Blood pressure was measured continuously and the frequency of breathing was controlled. RESULTS: No differences in HRV between the two sinus rhythm periods SR1 versus SR2 could be detected. Neither SR1 vs VAT showed a significant difference for SDNN and r-MSSD. In contrast, HRV during SR1 compared to AAI, and HRV during VAT compared to AAI were significantly different (p < 0.001). When comparing HRV during DDD, which should be zero, and AAI, we found a significantly lower SDNN and r-MSSD (1.2 ms vs 4 ms, p < 0.04). The presence of structural heart disease, a non-sustained ventricular tachycardia, a depressed ejection fraction of less than 0.50 did not reveal a significant influence on the HRV parameters (multivariate analysis). The mean Wenckebach in patients with structural heart disease tended to be greater (437 ms vs 350 ms, p = 0.05); an increase in the Wenckebach was not correlated to a change in HRV parameters (p = ns). CONCLUSION: Heart rate variability derived from consecutive RR-intervals is predominantly caused by periodicity in sinus-node impulse formation. A conduction variability of the AV-node exists, but is very low. The presence of a structural heart disease, a non-sustained ventricular tachycardia on Holter ECG, as well as a depressed ejection fraction of less than 0.50 showed no significant influence on the HRV parameters. Therefore, one can apply the calculation of heart rate variability for risk stratification in patients suffering from structural heart disease and moderate AV-nodal conduction disturbances. Attenuation of the oscillation of the heart rate, i. e. heart rate variability (HRV), is associated with an increased risk for mortality in patients with structural heart disease. Many of these patients also suffer from conduction disturbances, e. g. AV-nodal conduction delays. Whether the calculation of HRV in those patients is recommendable has not been investigated yet. Therefore, we conducted a study consisting of 20 consecutive patients in order to determine the formation of HRV, the influence of structural heart disease, the presence of a nonsustained ventricular tachycardia (VT), and a reduced ejection fraction (EF) on the HRV parameters during an elective electrophysiologic study.

Adult↗
PubMed2004

A new acceleration apparatus for the study of whiplash with human cadaveric cervical spine specimens.

The biomechanics of whiplash is often studied using cadaveric cervical spine specimens. One of the most important points in this kind of study is to create realistic loading conditions. The aim of the present project therefore was to develop an acceleration apparatus, which allows the study of whiplash with human cadaveric cervical spine specimens under as realistic loading conditions as possible. The new acceleration apparatus mainly consisted of a sled, a pneumatic acceleration unit and a railtrack and offered several unique features to create more realistic loading conditions. Among these features, the possibility to simulate the passive movements of the trunk is of capital importance. In this new apparatus, first, the general feasibility of whiplash experiments was studied, second, the reproducibility of the impacts was quantified and third, the effect of simulated movements of the trunk on accelerations and loads was examined. In the new acceleration apparatus various types of collisions could reproducibly be simulated. Simulated passive movements of the trunk strongly influenced the loading pattern of the neck. Without pivoting a steep increase of all loading parameters could be observed. This increase was less pronounced if pivoting was allowed. In conclusion, biomechanical aspects of whiplash could reproducibly be examined in the new acceleration apparatus. Due to its significant effects on the loading of the neck, pivoting of the trunk should always be taken into account in future experiments on the biomechanics of whiplash in which isolated cervical spine specimens are used.

Acceleration↗
PubMed2004

[Peak torque and proprioception at the ankle of dancers in professional training].

The ankle is a frequent site of injury for dancers. The aim of the controlled study was to examine the proprioceptive and sensorimotor control of the ankle in a group of dancers in professional training and to compare it with persons unused to physical training. The purpose was to investigate whether dance training influences the torque ratio of plantar flexion to dorsiflexion (PF/DF) and the proprioceptive performance compared to controls. 42 dancers (31 f, 11 m) in professional training and 40 sex- and age-matched controls performed a isokinetic peak torque test, a passive angle-reproduction test (Biodex System 3), and a single-limb-standing test. The female dancers showed a significantly higher peak torque ratio PF/DF at 30 degrees/s. The difference between male dancers and the controls did not reach a significant level. The dancers did not demonstrate lower absolute errors in passive angle-reproduction (5 degrees and 25 degrees PF) than controls. In the single-limb-standing test, the dancers achieved significantly better results than controls. Dancers could profit from special training of the dorsiflexors. In view of the balance deficits, coordinative exercises should be integrated into school and recreational sports more frequently.

Adolescent↗
PubMed2004

3-Azido-aspartic acid derivatives - orthogonally protected precursors for the stereoselective incorporation of 2,3-diaminosuccinic acid into peptide structures.

The stereoselective synthesis of orthogonally protected 3-azido aspartic acid derivatives is described. The convenience of their application as 2,3-diaminosuccinic acid in peptide chemistry was demonstrated by the incorporation of the nonproteinogenic diamino diacid as a cystine-substitute into the core structure of somatostatin.

Amino Acids, Diamino↗
PubMed2003

Analysis of injuries in long-distance triathletes.

Triathlon is an individual sport consisting of three disciplines - swimming, cycling and running. Triathlon has changed from a novel appearance to a very popular Olympic sport within the last fifteen years. Nevertheless, there is not sufficient data about injuries in triathlon. The aim of this retrospective survey was to investigate the incidence of injuries according to class of injuries, anatomical sites and disciplines. Relations to age, sex, performance level, training habits and medical care were analysed. Questionnaires were sent to all German speaking participants of the Ironman Europe 2000. With a response rate of 35 %, 656 questionnaires met the inclusion criteria. At least one injury was experienced by 74.8 % (95 %-CI: 71.3-78.1) of all respondents during their active time in triathlon. 51.1 % (95 %-CI: 47.2-55.0) suffered one or more contusion/skin-abrasions, 33.1 % (95 %-CI: 29.5-36.8) muscle-/tendon-injuries, 29.0 % (95 %-CI: 25.5-32.6) ligament-/capsule-injuries and 11.9 % (95 %-CI: 9.5-14.6) fractures. Most of the injuries happened during cycling (54.8 % [95 %-CI: 51.9-57.8]) within training sessions. 18.7 % (95 %-CI: 16.4-21.2) of all injuries occurred while the athletes were competing. Considering the low number of competition hours per year, the incidence of injuries during competition was higher than during training session. Significant relations were found considering the age, performance level and weekly training hours of the triathletes. Older athletes sustained more fractures (p = 0.024), high performance athletes suffered more contusions/abrasions (p = 0.003) and muscle-tendon-injuries (p = 0.001) and athletes with a large number of weekly training hours suffered more muscle-tendon-injuries (p = 0.014). To summarize, injuries in triathlon seem to be related to age, performance level and weekly training hours, but not to sex, presence of training coach and medical care.

Adolescent↗
PubMed2003

[Optimizing the management of type 2 diabetics: results of the "DREAM" study in general practice].

This paper reports the results of the "DREAM" ("Diabetes REinforcement of Adequate Management") study performed among 42 general practitioners. A treatment algorithm was proposed to intensify the management of type 2 diabetic patients in case of poor control (HbA1C > 7.5% and fasting blood glucose > 140 mg/dl) before asking for an advice from a diabetologist. A total of 163 patients participated in the study: 84 men and 79 women, 59 +/- 10 years old; 5.2 +/- 6.1 years of known duration of diabetes; BMI: 30.7 +/- 5.8 kg/m2. Almost two thirds of patients received an antihypertensive agent, one third a lipid-lowering drug, and three quarters at least one antidiabetic agent: 22% a sulfonylurea, 18% metformin, 25% a combined oral therapy, 10% insulin (alone or in combination). At baseline, mean HbA1C averaged 7.1 +/- 2.2% (N: 4-6%), and 34% of patients had HbA1C > 7.5%. From these 163 patients, 100 were evaluated after 12 months, 57% being well controlled vs 36% at baseline. Among the 32 patients whose hypoglycaemic treatment was intensified, HbA1C level significantly decreased by almost 0.8% (p < 0.05). Despite precise guidelines, 55% of patients with HbA1C > 7.5% had no treatment adjustment, essentially in the group already on oral bitherapy or on insulin. Among the 65 patients evaluated after 24 months, the percentage of well controlled patients decreased to 44% (vs 51% after 12 months). The decision of switching to insulin was often delayed (no patient after 1 year and 2 patients only after 2 years). In conclusion, the "DREAM" study demonstrates the feasibility, but also the difficulty, of optimising the management of type 2 diabetic patients in general practice.

Algorithms↗
PubMed2002

Measurement of spin-transfer observables in p p-->Lambda Lambda at 1.637 GeV/c.

Spin-transfer observables for p p-->Lambda Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables Dnn and Knn (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of Dnn and Knn presented here are found to be in disagreement with predictions from these models.

Journal Article↗
PubMed2002

Hypernuclear fine structure in (9)(lambda)Be.

With a germanium detector array (Hyperball), we observed two gamma-ray peaks corresponding to the two transitions (5/2(+)-->1/2(+) and 3/2(+)-->1/2(+)) in the (9)(Lambda)Be hypernucleus which was produced by the 9Be(K-,pi(-)) reaction. The energies of the gamma rays are 3029 +/- 2 +/- 1 keV and 3060 +/- 2 +/- 1 keV. The energy difference was measured to be 31.4(+2.5)(-3.6) keV, which indicates a very small Lambda-spin-dependent spin-orbit force between a Lambda and a nucleon. This is the smallest level splitting by far ever measured in a hypernucleus.

Journal Article↗
PubMed2002

[The "Adjusted Annual Index" (aJaX): A proposal for the use of the IMPP results in the evaluation of teaching at German medical faculties].

BACKGROUND AND OBJECTIVE: Teaching evaluations should create an incentive to improve academic teaching quality. Teaching also gains importance in the performance-oriented allocation of resources. The results of the country wide written examinations conducted by the Federal Institute for Medical and Pharmaceutical Examination Questions (IMPP) are obvious indicators for purposes of comparative evaluation. However, a comparison of medical faculties is confounded by heterogeneous proportions of students in the so called "reference group" This group includes students who attend their examinations within the regular duration of study; these candidates achieve significantly better results than other students. This contribution describes a comparative educational achievement index (aJaX) adjusting for the varying proportions of students in the reference group. MATERIAL AND METHODS: The IMPP publishes the results of the examinations, disaggregated according to faculties, type of examination, examination subjects, examination semester and membership in the reference group. Aggregation of the semi-annual data to annual data leads to equal treatment of faculties with different admittance regulations. The proportion of students in the reference group is taken into account by calculating an adjusted annual index (aJaX) which compares the observed result of the respective medical faculty with the result one would expect if the average (federal) outcome would apply to a faculty with an equal proportion of students in the reference group (i. e. indirect standardisation). RESULTS: The success rates of the faculties, as defined by the adjusted annual index aJaX, lie with a few exceptions in the interval between 0.95 and 1.05 during the years 1994 to 2000. The results of the second year examinations demonstrate the largest variance. Over time strong deviations rarely occur. These stable results are not observed with the frequently used reference-autumn-index (ReX), which only takes into consideration the results of the reference groups in the autumn examinations. Temporal trends therefore become more clearly visible in the aJaX. The faculties of the new federal states show a clear upward trend in the analysed period. CONCLUSIONS: The results of the medical faculties in the uniform examinations can be compared using an adjusted annual index aJaX. Advantages of the aJaX lie in its stability and neutrality, which are obtained by the annual aggregation of data and the reference group adjustment. The low degree of scatter emphasises a high standardisation in academic medical teaching. However, the aJaX measures only one output of teaching. For the assessment of teaching efficiency in the sense of an input/output relation, inputs must also be taken into account, such as the final school grades of the entering and transferring students.

Education, Medical↗
PubMed2002

[Low-grade central osteosarcoma . 3 case reports].

Low-grade central osteosarcoma is a well-differentiated subtype of osteosarcoma, which is often confused with benign lesions. Males and females were affected about equally in our study. The tibia and femur were most commonly involved. Three case reports demonstrate the distinct features of the tumor. Excision of the tumor almost invariably led to recurrences. Wide resection was almost never followed by recurrence and seems to be the treatment of choice for this very rare variant of osteosarcoma.

Adolescent↗
PubMed2002

An X-ray-based method for the determination of the contrast agent propagation in 3-D vessel structures.

A method for the determination of the contrast-agent propagation in vessel trees is presented. A standard three-dimensional (3-D) rotational angiography procedure is performed to reconstruct the morphology of the contrast-filled vessel tree in a 3-D volume. An additional fluoroscopy projection series acquired with a fixed projection angle delivers the temporal information of the bolus propagating. The mapping of the propagation information from the two-dimensional projections to the 3-D image data set is the topic of this paper. A symbolic tree structure is built up that represents the vessel tree including bifurcations. Neighborhood relations between vessel pieces are given in three dimensions. This facilitates filtering procedures and plausibility controls of the resulting time dependent 3-D data set. The presented method proved to be accurate with phantom data and gives novel insight in the feeding structure of arterio-venous malformations and aneurysms.

Algorithms↗
PubMed2001

Transformation of mutagenic aromatic amines into non-mutagenic species by alkyl substituents. Part I. Alkylation ortho to the amino function.

Alkyl-substituted derivatives of 2-aminonaphthalene (2-AN) 1, 2-aminofluorene (2-AF) 6 and 4-aminobiphenyl (4-ABP) 11 were synthesized and the mutagenic activity of these compounds determined in Salmonella typhimurium strains TA98 and TA100 with and without S9 mix. In the case of the ortho-substituted 4-aminobiphenyls 12-15 (3-alkyl=ethyl, iso-propyl, n-butyl, tert-butyl) the substituent with the strongest steric demand (3-tert-butyl) shows the strongest influence on the decrease of mutagenicity if compared with the parent compound. In the series of the bis-ortho-disubstituted compounds 16-18 (3,5-dimethyl-, 3,5-diethyl- and 3,5-diisopropyl-4-aminobiphenyl) generation of non-mutagenic species occurs already with the introduction of two ethyl groups. For the 4-aminobiphenyl derivatives 12-15 and 16-18, as well as for the 1-alkylated 2-aminofluorenes 7-10 and the 1-alkylated 2-aminonaphthalenes 2-5 a smaller mutagenicity was observed if compared with predicted mutagenicities as calculated by the QSAR equations of Debnath et al. (Environ. Mol. Mutagen. 19 (1992) 37). The largest differences resulted in the cases of the tert-butyl substituted compounds. Only with smaller alkyl groups like ethyl the QSAR predictions and the experimentally determined mutagenicities come close to each other. Thus, these results show that appropriate alkyl substitution reduces (eliminates) mutagenicity, secondly, it is necessary to introduce steric parameters to predict the mutagenicity of such compounds correctly.

2-Naphthylamine↗
PubMed2001

Clinical performance of a specific algorithm to reconfirm self-terminating ventricular arrhythmias in current implantable cardioverter-defibrillators.

Inappropriate shock therapy is a frequent problem in patients with implantable cardioverter-defibrillators (ICDs), caused mostly by supraventricular rhythms. Self-terminating ventricular arrhythmias (STVAs), however, may also lead to inappropriate shock discharges even in ICDs with abortive shock capabilities. The aim of this study was to evaluate the clinical performance of a specific ventricular tachycardia/ventricular fibrillation (VT/VF) reconfirmation algorithm implemented in current ICD devices from Medtronic to prevent inappropriate shock discharges due to STVAs. A total of 161 STVA episodes were documented in 59 of 150 patients (39%) within a mean follow-up of 30 +/- 20 months and resulted in 25 inappropriate shock discharges in 15 of 150 patients (10%) despite activation of the reconfirmation algorithm. The first synchronization interval of the algorithm was met in 92% of STVA episodes with and even 38% of STVA episodes without shock delivery. A reduced incidence of inappropriate shocks due to STVAs was found with tachycardia/fibrillation detection intervals (TDI/FDI) programmed to shorter cycle lengths < or =280 ms or the use of the first 2 cycles after the end of charging to be considered for reconfirmation only. Thus, inappropriate shocks due to STVAs still occur in 10% of patients with ICDs despite activation of a specific VT/VF reconfirmation algorithm, and are mainly caused by meeting the first synchronization interval that therefore should be shortened in cycle length. Moreover, to reduce the likelihood of inappropriate shocks, the VF reconfirmation algorithm should be optimized by basing the synchronization intervals exclusively on the FDI with short cycle lengths or using the first 2 cycles for reconfirmation only.

Algorithms↗