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Biomedical subjects

M Schneider

Publications and source records attributed to M Schneider.

At least 55 records · Page 3Linked to original sources
PubMed2005

[Is computer navigation a useful tool in unicompartmental knee arthroplasty? A pilot cadaver study].

We conducted this pilot cadaver study to investigate whether the use of a navigation system during minimally invasive unicompartmental knee arthroplasty leads to more consistent results than the conventional hand-guided technique. We describe the accuracy of implant positioning in using standard instrumentation and computer navigation. Radiographic assessment showed that accurate component placement was achieved using both methods. These results were not statistically significant. The computer navigated femoral component placement without intramedullary (IM) rod was as accurate as the conventional method with IM rod. The study showed that computer navigation can produce accurate results even without an intramedullary rod. Image guidance can maintain the accuracy of the standard instrumentation and enhance 3D vision and the intraoperative orientation of the surgeon.

Arthroplasty, Replacement, Knee↗
PubMed2005

[Two-photon fluorescence of ocular melanomas. Studies on a new diagnostic method].

Choroidal melanoma is the most frequent form of primary neoplasia among malignant ocular tumors. Since it is presumed that metastasis often occurs before the primary tumor is first diagnosed, early detection is exigent. The aim of the studies described in this report was to develop an objective, noninvasive method for the diagnosis of choroidal melanoma. The underlying new principle of fluorescence excitation is presented. This is based on the observation that melanin, due to its unique absorption characteristics, is selectively excited into fluorescence via stepwise absorption of two photons of a femtosecond laser emitting at 800 nm. In the experiment described, the fluorescence of excised tissue from healthy choroidal pigment epithelium was compared to that of excised choroidal melanoma. The fluorescence of choroidal melanomas exhibited a more reddish appearance and less intensity than that of healthy tissue. This implies that the configuration of melanin apparently changes during the process of malignant degeneration. The method described here could thus serve as an evidentiary objective diagnostic technique before initiating treatment for choroidal melanomas.

Animals↗
PubMed2005

[Lupus in Germany: analysis within the German lupus self-help organization (LULA)].

During the last few decades, the prognosis for patients with systemic lupus erythematosus (LE) has changed from high early mortality to a more chronic longterm course. Although the prevalence of LE has been estimated at 20-50/100,000, data concerning the situation of LE patients in Germany are sparse. Since 2001, a documentation within the German Lupus Self-Help Organisation scheduled for a period of 10 years (LULA) has been recording at the patient level the actual status and the long-term course of a large group of LE patients. A questionnaire adapted from the German rheumatological database is updated once a year and sent to all members.In 2001, 1033 members participated in the documentation. Of these, 92.2% were women (mean age 45.8 years) with a mean disease duration of 9.9 years. 37.6% were employed, and 24.5% were on early retirement. 50.2% rated their overall health status as "not so good" or "poor". Most were receiving treatment with [hydroxy-]chloroquine (35.2%) or azathioprine (21.9%), while 67.9% were receiving corticosteroids. The most frequent comorbidities reported were hypertension (33%), scarring skin disease (24.4%), osteoarthritis (25.2%), osteoporosis (24%), psychiatric disorders/depression (22.9%) and chronic renal disease (22%). Thromboembolic events were reported in 18.5%, myocardial infarction in 2.3% and stroke in 4.8% of cases. Concerning their main contact person for health care, 63.6% specified the rheumatologist. In comparison with other cohort studies and in particular with the German rheumatological database, the data provided exclusively by patients are feasible. Concerning the severity of their disease, their treatment and their global assessment of health status, LULA participants are comparable with other LE patients and can be seen as representative of LE patients in Germany. Further assessment especially of long-term data are needed to obtain additional insights into the burden of the disease and the need for special medical care.

Adult↗
PubMed2005

[Accelerated atherosclerosis in rheumatic systemic diseases as an example of systemic lupus erythematosus--what is the consequence?].

Large increases in mortality related to premature atherosclerosis with coronary artery disease and stroke have been reported during the last few years in patients with systemic lupus erythematosus (SLE). Studies found relative risks of 5 to 7 for myocardial infarction in SLE patients. The traditional risk factors fail to fully account for accelerated atherosclerosis in SLE and APS, in addition prolonged glucocorticoid therapy and long duration of SLE seem to be of importance. The disease SLE per se is an independent risk factor. The current pathogenic hypothesis for atherosclerosis involves an inflammatory response, autoantibodies, immune complexes (containing antibodies to phospholipids, to oxidized LDLs, and to endothelial cells), CD40/CD40 ligand interactions, and bacterial or viral infections responsible for an immune response. The determination of classic and new risk factors, together with specific autoantibody titers and the use of Doppler carotid ultrasound, are useful methods to detect early atherosclerosis. Therapeutic strategies, including early risk factor intervention and effective control of inflammation, are essential to reduce morbidity and mortality and should be incorporated into the management of connective tissue disease with the goal of protecting patients against atherosclerosis.

Arteriosclerosis↗
PubMed2005

[Early diagnosis of rheumatoid arthritis].

The therapeutic concept of rheumatoid arthritis changed dramatically during the last years. There is significant evidence for the need of an early treatment with disease modifying drugs, the new therapeutic aim is remission. And then the question is: what is a rheumatoid arthritis and when does it start? There is move into the direction of an early undifferentiated arthritis, which may or may not become a persistent arthritis with or without development of erosions. Diagnostic criteria for rheumatoid arthritis are not exsisting, and this article comes after reviewing the existing instruments to the conclusion there is no need for such criteria. In fact, there is a need for instruments that evaluate the risk of an individual patient for persistence, erosive arthritis, and even better, the severity of the disease, which means a judgement of progression. And then the rheumatologists can set the crossbar for starting a DMARD-therapy.

Arthritis, Rheumatoid↗
PubMed2005

Push-and-pull enteroscopy using the double-balloon technique: method of assessing depth of insertion and training of the enteroscopy technique using the Erlangen Endo-Trainer.

BACKGROUND AND STUDY AIMS: This study was conducted to test a method of measuring the depth of insertion into the small bowel during push-and-pull enteroscopy using the Erlangen Endo-Trainer. Furthermore, the Erlangen Endo-Trainer model for training in the new method of push-and-pull enteroscopy using the double-balloon technique was also evaluated. MATERIALS AND METHODS: Specially prepared packages of porcine upper visceral organs were used, including the esophagus, stomach, duodenum, and small bowel, implanted into the Erlangen Endo-Trainer. In the first step of this study, all of the modifications needed to obtain a model useful for training in the new enteroscopy technique were tested, including different lengths of small bowel. In the next step, the Erlangen Endo-Trainer was used to evaluate a special method of measuring the depth of insertion during push-and-pull enteroscopy by comparing estimated insertion depths of 100 cm and 200 cm, marked on the porcine small bowel, with endoscopic insertion depths determined afterwards by measuring the length of the small bowel from the pylorus to the mark on the porcine small bowel. Additionally, the Endotrainer was used to demonstrate the principle of double-balloon enteroscopy and to provide training in this new enteroscopy technique with a lifelike simulation. RESULTS: The modified Erlangen Endo-Trainer proved its value for demonstrating the principle of push-and-pull enteroscopy and for providing training in this enteroscopic technique as well as for testing the measurement method. The evaluation of the measurement method showed that the estimation of the insertion depths was accurate, with a mean deviation of less than 10 %. A total of 13 workshops (seven national and six international), including a total of 97 participants, were carried out between January and August 2004. Under the supervision of one of the authors, pairs of trainees were able to reach the ileal valve or the end of the small bowel from the oral route. CONCLUSIONS: The modified Erlangen Endo-Trainer is useful for training in the push-and-pull enteroscopy technique. The new specially developed method of measuring the depth of insertion during push-and-pull enteroscopy seems to be valid.

Animals↗
PubMed2005

Behavioral effects in adult rats of chronic prepubertal treatment with the cannabinoid receptor agonist WIN 55,212-2.

Human and animal studies provide evidence for vulnerable periods of brain development for deleterious effects of cannabinoids. We have recently shown that pubertal chronic cannabinoid treatment leads to long-lasting behavioral deficits, whereas a comparable treatment in adult rats did not affect the animals' behavior. In the present study we examined the effects of an identical chronic cannabinoid treatment in juvenile rats, just before the onset of puberty. Treatment with the synthetic cannabinoid agonist WIN 55,212-2 (WIN) (1.2 mg/kg) or vehicle was extended over 25 days throughout the prepubertal period (postnatal days 15-40) in juvenile rats. The rats received a total of 20 injections intraperitoneally. Adult rats were tested for object recognition memory, performance in a progressive ratio (PR) operant behavior task, locomotor activity and prepulse inhibition (PPI) of the acoustic startle response. Juvenile chronic WIN administration had no effect on object recognition memory, PR performance and locomotor activity in adulthood. However, a PPI deficit was observed in WIN-treated rats when tested as adults that could be reversed by the acute administration of the dopamine receptor antagonist haloperidol (0.1 mg/kg). Additionally, juvenile cannabinoid treatment reduced the number of rearings, as well as the time spent in the center of the open field in adult rats, suggesting increased anxiety. Juvenile chronic cannabinoid treatment induced behavioral disturbances in adult rats that are less severe than those observed after pubertal cannabinoid administration. However, based on the observations of sensorimotor gating deficits and increased anxiety, we conclude that the prepubertal developmental phase, in addition to puberty, also represents a vulnerable time period for persistent adverse effects of cannabinoids.

Aging↗
PubMed2004

[Pituitary insufficiency following head injury--how common is it, and what is to be done?].

In Germany,traumatic brain injury (TBI) has an annual incidence of approximately 200000. In contrast to earlier assumptions, pituitary insufficiency is a common complication of TBI, with a prevalence of 30-50%. Since the symptoms are often nonspecific and may be masked by the sequelae of head injury, it may go unrecognized and may possibly aggravate the symptomatology of such injury. It is therefore to be recommended that patients who suffer a head injury should be examined to exclude pituitary gland insufficiency, by measuring the basal hormone level--where necessary in combination with stimulation tests.

Brain Injuries↗
PubMed2004

Two year maintenance of efficacy and safety of infliximab in the treatment of ankylosing spondylitis.

OBJECTIVE: To obtain results of the second year extension of an original 3 month randomised, placebo controlled trial (and the 1 year extension study) assessing the use of infliximab, a monoclonal antibody to tumour necrosis factor alpha, for the treatment of patients with ankylosing spondylitis (AS). METHODS: Of the 54 patients with AS who completed the first year of the study, 52 continued to receive infliximab 5 mg/kg every 6 weeks up to week 102. The primary end point was the proportion of patients achieving at least 50% improvement from baseline in the Bath AS Disease Activity Index (BASDAI) at week 102. Other assessments included patient and physician global assessments, quality of life as assessed by Short Form-36, Bath AS Functional Index, Bath AS Metrology Index, and C reactive protein (CRP). RESULTS: Improvement in signs and symptoms of AS seen during the first year of the study was sustained during the second year. Forty nine patients (71% of 69 enrolled patients and 49/52 (94%) patients who started year 2) completed the study up to week 102. Thirty (58%) patients achieved at least 50% improvement from baseline in the BASDAI score at week 102. Scores for other efficacy assessments were similar at weeks 54 and 102. Median CRP levels remained low at weeks 54 and 102 (3.9 and 4.3 mg/l, respectively). Side effects during the second year of the study were similar to those of the first year of treatment with infliximab. CONCLUSIONS: Patients with AS treated for 2 years with infliximab 5 mg/kg exhibited a good and durable clinical response.

Adult↗
PubMed2004

Preliminary results of safety and efficacy of the interleukin 1 receptor antagonist anakinra in patients with severe lupus arthritis.

BACKGROUND: Joint involvement occurs in most patients with systemic lupus erythematosus (SLE), and severe lupus arthritis is often refractory to conventional treatments. Anakinra is used in the treatment of rheumatoid arthritis, but its therapeutic potential has not been proved in patients with SLE. OBJECTIVE: To determine the safety/tolerability and efficacy of anakinra in patients with SLE with leading joint involvement. METHODS: In patients with SLE with active polyarthritis and no other uncontrolled systemic/organ manifestations, 100 mg/day anakinra was self administered subcutaneously for 3 months. Disease activity was assessed by VAS, number of swollen/tender joints, ECLAM score, and serological and immunological measures. RESULTS: Four patients with SLE were studied; anakinra was safe in all four patients and no drug related serious adverse events occurred. A subjective benefit was seen in all patients and a trend towards better activity measures after 4 weeks. After an initial response, one patient left the study because of an arthritic flare after 6 weeks. CONCLUSION: In this study anakinra was apparently safe and well tolerated and led to clinical and serological improvement. Anakinra might be an interesting alternative in individual patients with lupus arthritis not responding to conventional treatments.

Adult↗
PubMed2004

Origin of higher order magnetic exchange: evidence for local dimer exchange striction in CsMn0.28Mg0.72Br3 probed by inelastic neutron scattering.

The origin of higher-order exchange interactions in localized S-state systems has been the subject of intensive investigations in the past. In particular, it has been suggested that a biquadratic exchange term may arise from the magnetoelastic energy. Here we report on the pressure and temperature dependence of the excitation spectra of magnetic Mn2+ dimers in CsMn0.28Mg0.72Br3 probed by inelastic neutron scattering. Biquadratic exchange and a strong distance dependence of the bilinear exchange are observed. It is shown that the mechanism of local exchange striction may explain the occurrence of biquadratic exchange in accordance with the elastic properties of the compound.

Journal Article↗
PubMed2004

[Interventional cardiology in Latvia from 1993 to 2003].

A nationale programme for combatting cardiovascular diseases is being implemented in Letvia. A milestone was reached in 1993 with the establishment of a Letvian Centre for Cardiology. Within 10 years the only cardiac catheterization unit in the country has developed into a centre of excellence. But to meet the cardiological needs for all of Letvia requires at least three additional units for left heart catheterization and one for paediatric a cardiac catheterization.

Adult↗
PubMed2004

[Levosimendan. Clinical indications of a new vasoactive substance].

Levosimendan is a recently developed drug which is not yet approved for clinical routine use in Germany. The clinical use is limited to a few selected cases and it has been used as a salvage therapy in patients with severe heart insufficiency. As a potent inodilator it has been given to patients with severe heart failure, when all other therapeutic options have failed. However, in some European countries levosimendan is used in clinical routine situations and the European Society of Cardiologists has included the drug in their guidelines for treatment of acute heart failure. The following article describes the main pharmacological characteristics of levosimendan and summarises the indications for this new drug for physicians working in the field of anaesthesia or intensive care.

Cardiotonic Agents↗
PubMed2004

[National database of German arthritis centers. Tool for health services research].

The national database of the German Collaborative Arthritis Centers is a joint venture of German rheumatology. Since 1993, all outpatients with inflammatory rheumatic diseases treated in 1 of 24 arthritis centers have been registered once a year with a clinical record form and a patient questionnaire. The aim is to continuously monitor the current state and trends in rheumatologic health care and to gain knowledge on the outcomes and burdens of diseases as well as medical, social, and economic consequences beyond the limited perspective of randomized controlled trials. Data collected for 10 years about 145,000 patients with inflammatory rheumatic diseases are available making it possible to analyze even very rare diseases with sufficient numbers of cases. Selected results concerning the health care situation in specialized and nonspecialized care, practice variations in rheumatology, and the burden of illness in various diseases are reported.

Adult↗