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Biomedical subjects

U Weber

Publications and source records attributed to U Weber.

At least 37 records · Page 2Linked to original sources

[Influence of a resistance training on pulmonary function and performance measures of patients with COPD].

BACKGROUND: Training therapy with its manifold effects should be part of a modern and multi modular treatment of the COPD. Because of the specific symptoms (e. g. muscle atrophy, dyspnea, low testosterone levels) and the deconditioning of these patients, a resistance training might meet the demands of a COPD-exercise-therapy rather than an endurance training. The aim of this research project was to evaluate the efficiency of a hypertrophic maximal strength training on various COPD relevant parameters. METHODS: 28 patients with moderate to severe COPD (m12/f16) were randomized and divided in a treatment and a control group. The patients in the treatment group underwent a resistance training (hypertrophic maximal strength training) for 12 weeks, initially two times, then three times a week. RESULTS: Considering the results of the daily Peak-Flow-Measurement, there was no significant change in both groups, but a trend towards an improvement could be found in the treatment group. There was no difference in the change of FEV 1. The performance on the ergo cycle showed a highly significant improvement (p < 0.001) in the treatment group of 18.7 % (21.9 Watt). The results of the SGRQ showed a significant improvement (p < 0.05) of the HRQL in the treatment group. A change of the HRQL in the control group was not found. CONCLUSIONS: These data support the hypotheses that a short term high intensity strength training programme is suitable to improve performance measures of patients with moderate to severe COPD and it might also improve pulmonary function. The conclusion can be drawn, that this kind of resistance training can be prefered as COPD-specific training therapy and offers new treatment perspectives.

Exercise↗

A non-randomised pilot study to compare complementary and conventional treatments of acute sinusitis.

BACKGROUND: It is still under discussion whether antibiotics are effective in the treatment of acute sinusitis. Moreover, they are known to have considerable side-effects. In contrast, complementary approaches are reported to have little side-effects and an equivalent efficiency. OBJECTIVES: To assess the success of conventional and complementary treatments of acute sinusitis and to estimate the patient numbers needed to confirm therapeutic equivalence. Treatment success was measured by three different scores, assessed by both patients and physicians. METHODS: Multicentre (2 complementary and 3 conventional ENT centres), non-randomised, controlled clinical trial with 63 patients (complementary group 30, conventional group 33 patients). To control for confounders treatment differences were estimated by propensity score techniques. TREATMENTS: The choice of medication was entirely left to the physician. We recommended to use antibiotics, secretolytics and symptomimetics in the conventional group and a combination of the herbal remedy Sinupret((R)) and the homeopathic remedy Cinnabaris 3X in the complementary group. RESULTS: Treatment differences varied substantially depending on the outcome measure, but they were always not clinically relevant. Conventional treatment was slightly better when the outcome was assessed by the physicians (1.8 score points) but slightly worse when it was assessed by patients (0.2 score points) or in terms of the HCG-5 quality of life score (0.8 score points). p values were always > 0.3. CONCLUSIONS: Both treatments appear to be equally effective (or ineffective). Results might be biased because both treatment groups differed substantially. Randomised trials including at least 400 patients are needed to produce valid results.

Acute Disease↗

An example on the value of non-randomisation in clinical trials in complementary medicine.

BACKGROUND: Randomised clinical trials may in principle show a small external validity. Non-randomised clinical trials therefore are sometimes regarded as an appropriate alternative when complementary and conventional treatments are compared. OBJECTIVES: To assess the value of advanced statistical methods in the process of estimating differences between a complementary and a conventional treatment of acute sinusitis in a non-randomised clinical trial. METHODS: Multicentre, non-randomised, controlled clinical trial comparing 2 complementary and 3 conventional ENT centres. Patients were free to choose the physician (and hence the therapy). Treatment differences were estimated by controlling for confounders in analyses of covariance or by propensity score techniques. RESULTS: Most potential confounders (sex, age, life-style parameters) did not have significant effects on the choice of therapy. Disease severity and previous ENT surgery were the main confounding factors. At study onset they almost cause a defined separation of both treatment groups. As a result estimated treatment differences vary substantially depending on the chosen statistical model. CONCLUSIONS: When comparing complementary and conventional treatments, non-randomised clinical trials may be misleading. Results may be strongly biased even when advanced statistical methods are used. Trials of complex statistical designs are needed to give valid results.

Acute Disease↗

Infection of the skin caused by Corynebacterium ulcerans and mimicking classical cutaneous diphtheria.

Extrapharyngeal infections caused by Corynebacterium ulcerans have rarely been reported previously, and diphtheria toxin production has usually not been addressed. This case demonstrates that strains of C. ulcerans that produce diphtheria toxin can cause infections of the skin that completely mimic typical cutaneous diphtheria, thereby potentially providing a source of bacteria capable of causing life-threatening diseases in the patient's environment. Therefore, it is recommended to screen wound swabs for coryneform bacteria, identify all isolates, carefully assess possible toxin production, and send questionable strains to a specialist or a reference laboratory.

Aged↗

[Post-traumatic kyphosis of the truncal vertebrae].

Assessing the initial post-traumatic situation is of imminent importance in choosing the most suitable approach for primary treatment of thoracic and lumbar spine fractures. Misjudging the static situation of the injured spine is a common reason for selecting an inadequate therapeutic procedure. The consequence is a defective spinal position with the corresponding symptoms, which usually requires a complicated surgical procedure. Our experience is based on 34 patients with a post-traumatic defective position of the thoracic and lumbar spine: 12 patients underwent primary surgical and 22 primary conservative treatment. The aim of our study was to demonstrate the initial situation and primary management as well as subsequent problems and the respective surgical procedure applied in our department for correcting and stabilizing the areas involved and to present intermediate results.

Adolescent↗

[Alignment of the sagittal profile after surgical therapy of nonspecific destructive spondylodiscitis: ventral or ventrodorsal method--a comparison of outcomes].

From 1989 to 1998, 129 patients underwent surgery for unspecific spondylodiscitis in the Department of Orthopedics of the Free University of Berlin. Fifty-six of them were followed up, and their clinical and radiological results were evaluated in this study. The surgical results of 40 patients with only ventral removal of a focus and defect coverage with an iliac crest graft were compared to those of 16 with additional dorsal bridging instrumentation by internal fixation. A mean of 2.3 vertebrae were fused in ventral spondylodesis; the mean length of dorsal instrumentation by internal fixation was 3.8 vertebrae. Patients were followed up a mean of 5.1 years after surgery. The mean age of patients was 57.1 years at the time of surgery. Patients were postoperatively mobilized a mean of 5 days after ventrodorsal fusion. A purely ventral procedure required a mean postoperative immobilization period of 3.6 weeks and brace fitting of a mean 8.2 months. There was one case of recurrent spondylodiscitis 25 months postoperatively, which made a revision of the focus necessary. The consolidation rate of the ventral spondylodesis was 84-100% in the different subgroups. A differential view of the spinal areas and ventral fusion segments was used to make a statement about the development of the sagittal spine profile. The segmental position of the spine in the sagittal plane was assessed by comparing the segmental kyphosis angles to normal values in the literature. All subgroups submitted to combined ventrodorsal fusion had a greater preoperative segmental kyphosis angle than those undergoing ventral fusion alone. In marked segmental kyphotic false positioning, the combined ventrodorsal procedure achieved good postoperative repositioning results, and an increase in segmental kyphosis was prevented. Ventral removal of a focus and bone graft spondylodesis seem to be adequate in single-level spondylodiskitis especially in the lumbar spine, but additional dorsal instrumentation should be performed in the case of long ventral fusion.

Adolescent↗

[Secondary deformities after section of primary bone tumors of the spine in children and adolescents].

Primary bone tumors and tumor-like lesions of the vertebral column are rare in children. After operative tumor resection, 25 children under the age of 17 could be reviewed in a retrospective analysis. Malignant bone tumors occurred only twice in the region of the vertebral body. No deformity was registered in 9 of 16 cases after local tumor resection with and without laminectomy on one level. In contrast, after resection of one or both facets in combination with laminectomy cranial to L4 or thoracal, progressive kyphosis was found within 6-22 months postoperatively in four cases. This required a secondary fusion. After primary fusion and instrumentation, no deformity was registered. In nine cases with a location of the tumor in the vertebral body, only two patients developed a secondary instability of the spine. Both cases had no primary fusion. The other seven patients with initial fusion and instrumentation showed no deformity within 24 up to 127 months postoperatively. These results are compared with data from the current literature.

Adolescent↗

[Correction of lumbosacral kyphosis in high grade spondylolisthesis and spondyloptosis].

Spondyloptoses, but also high-grade spondylolistheses, usually only develop at the lumbosacral junction and are nearly always classed among dysplastic spondylolistheses. Kyphosis of the lumbosacral junction leads to compensation mechanisms with increased lumbar lordosis and straightening of the pelvic tilt with involvement of the hip and knee joints. Reconstructing a physiological sagittal profile by more or less complete repositioning with permanent fusion of only the lumbosacral motion segment is thus of primary importance in the surgical management of high-grade spondylolisthesis and spondyloptosis. This aim led to the following treatment modality: Dorsal repositioning following sacral dome resection with subsequent intersomatic fusion with the posterior lumbar interbody fusion (PLIF) technique. This procedure was performed in 11 patients between January 1995 and January 1998 for six grade IV spondylolistheses and five spondyloptoses. Four patients had undergone previous surgery. Measurements of the slip angle (Boxall), sagittal translation (Taillard), sacral inclination (Boxall), and sagittal rotation (Wiltse and Winter) were done in the follow-up and to check the postoperative results. Denis' pain scale was used to classify pre- and postoperative complaints as well as those of the last examination. Only one inadequate repositioning occurred in a previously operated patient who required instrumentation from L4 to S1 after a pedicle screw had been torn out at L5. In another previously operated patient, the dura was damaged intraoperatively and managed accordingly. Postoperatively, this patient developed a unilateral nerve root syndrome, which did not improve in the further course. Another patient developed decompensation of the adjacent cranial motion segment in the follow-up period. In ten cases complete or nearly complete reposition was achieved. Firm bone consolidation was seen in all patients. Complaints were markedly reduced in all patients compared to the preoperative status.

Adolescent↗

[Surgical possibilities in the treatment of diseases and injuries of the spine in patients with manifest osteoporosis ].

In the presence of a vertebral injury or disease, manifest osteoporosis affects preoperative planning. Thus, if surgery is indicated, bone density should be determined in cases of suspected or diagnosed osteoporosis. Instrumentation of the spine is frequently not required in surgical interventions. However, if indicated, instrumentation should be fixed multifocally and the deformity should be corrected with special care. It is absolutely necessary to avoid ending instrumentation within a kyphosis.

Aged↗

[Virus relevant physicochemical parameters of viscoelastics in cataract operation].

PURPOSE: To define the physicochemical parameters of viscoelastics that are most important for visual acuity after phacoemulsification. MATERIAL AND METHODS: Eleven commercially available viscoelastics (ophthalmic viscosurgical device, OVD) were used in consecutive cataract operations. In addition to clinical findings, we assessed visual acuity, intraocular pressure, endothelial cell density, and pachymetric data preoperatively and on the first postoperative day. RESULTS: On the first postoperative day the loss of endothelial cells in all phacoemulsifications was 0.661%, corrected for 1 s phacotime, while corneal thickness increased by 0.2384% and visual acuity by 5.206%, and intraocular pressure decreased by 0.306%. The most important parameters for visual acuity were the concentration of sodium hyaluronate and viscosity (100/s.) of the OVD. Pachymetric data were more relevant for postoperative visual acuity than endothelial cell counts. CONCLUSION: Early visual rehabilitation after phacoemulsification depends on stable pachymetric data. OVD with a high content of sodium hyaluronate and high viscosity significantly reduces corneal swelling and improves visual acuity after phacoemulsifications on the first postoperative day.

Cornea↗

The role of the Drosophila TAK homologue dTAK during development.

The TAK kinases belong to the MAPKKK group and have been implicated in a variety of signaling events. Originally described as a TGF-beta activated kinase (TAK) it has, however, subsequently been demonstrated to signal through p38, Jun N-terminal kinase (JNK) and Nemo types of MAP kinases, and the NFkappaB inducing kinase. Despite these multiple proposed functions, the in vivo role of TAK family kinases remains unclear. Here we report the isolation and genetic characterization of the Drosophila TAK homologue (dTAK). By employing overexpression and double-stranded RNA interference (RNAi) techniques we have analyzed its function during embryogenesis and larval development. Overexpression of dTAK in the embryonic epidermis is sufficient to induce the transcription of the JNK target genes decapentaplegic and puckered. Furthermore, overexpression of dominant negative (DN) or wild-type forms of dTAK in wing and eye imaginal discs, respectively, results in defects in thorax closure and ommatidial planar polarity, two well described phenotypes associated with JNK signaling activity. Surprisingly, RNAi and DN-dTAK expression studies in the embryo argue for a differential requirement of dTAK during developmental processes controlled by JNK signaling, and a redundant or minor role of dTAK in dorsal closure. In addition, dTAK-mediated activation of JNK in the Drosophila eye imaginal disc leads to an eye ablation phenotype due to ectopically induced apoptotic cell death. Genetic analyses in the eye indicate that dTAK can also act through the p38 and Nemo kinases in imaginal discs. Our results suggest that dTAK can act as a JNKKK upstream of JNK in multiple contexts and also other MAPKs in the eye. However, the loss-of-function RNAi studies indicate that it is not strictly required and thus either redundant or playing only a minor role in the context of embryonic dorsal closure.

Amino Acid Sequence↗

Treatment of femoral head necrosis with vascularized iliac crest transplants.

The development of microsurgical methods has allowed for the use of vascularized bone transplants in the treatment of femoral head necrosis, particularly for Stages II, III, and IV according to the Association Internationale de Recherche sur la Circulation Osseuse classification system. Eighty patients with avascular necrosis of the femoral head were treated with vascular pedicled iliac crest transplant, perfused by the circumflexed ilium profunda artery between 1988 and 1996. On average, the postoperative followup was 5 years. Evaluation was based on the Harris hip score, and clinical and radiologic examination. Clinical results according to the Harris hip score were good or excellent in 86.6% of the patients. Radiologic appearance during the followup remained stable in 56.1% of the patients according to the classification system of the Association Internationale de Recherche sur la Circulation Osseuse. These findings are compatible with the findings of other studies in which vascularized bone transplants were used and approximately 50% of the patients with Stages II, III, and IV, according to the classification of the Association Internationale de Recherche sur la Circulation Osseuse had an unchanged stage of disease 5 to 6 years after the procedure.

Adult↗

2000 Volvo Award winner in biomechanical studies: Monitoring in vivo implant loads with a telemeterized internal spinal fixation device.

STUDY DESIGN: Implant loads were measured in 10 patients using telemeterized internal spinal fixation devices. OBJECTIVE: To determine the postoperative temporal course of implant loads. SUMMARY OF BACKGROUND DATA: Little information exists regarding the temporal course of loads on internal spinal fixation devices. METHODS: The telemeterized internal spinal fixator allows the measurement of three force components and three moments acting in the fixator. Implant loads were determined in up to 20 measuring sessions for different activities, including walking, standing, sitting, lying in the supine position, and lifting an extended leg while in the supine position. RESULTS: Implant loads often increased shortly after anterior interbody fusion was performed. Several patients retained the same high level even after fusion had taken place. This explains the reason why screw breakage sometimes occurs more than half a year after implantation. The time of fusion could not be pinpointed from the loading curves. CONCLUSIONS: The results show that fixators may be highly loaded even after fusion has occurred. A flexion bending moment acts on the implant even with the body in a relaxed lying position. This means that already shortly after the anterior procedure, the shape of the spine is not neutral and unloaded, but slightly deformed, which loads the fixators. Pedicle screw breakage more than half a year after insertion does not prove that anterior interbody fusion has not occurred.

Adult↗

Nuclear signaling by Rac and Rho GTPases is required in the establishment of epithelial planar polarity in the Drosophila eye.

BACKGROUND: The small GTPases Rac and Rho act as cellular switches in many important biological processes. In the fruit fly Drosophila, RhoA participates in the establishment of planar polarity, a process mediated by the receptor Frizzled (Fz). Thus far, analysis of Rac in this process has not been possible because of the absence of mutant Rac alleles. Here, we have investigated the role of Rac and Rho in establishing the polarity of ommatidia in the Drosophila eye. RESULTS: By expressing a dominant negative or a constitutively activated form of Rac1, we interfered specifically with Rac signaling and disrupted ommatidial polarity. The resulting defects were similar to the loss/gain-of-function phenotypes typical of tissue-polarity genes. Through genetic interaction and rescue experiments involving a polarity-specific, loss-of-function dishevelled (dsh) allele, we found that Rac1 acts downstream of Dsh in the Fz signaling pathway, but upstream of, or in parallel to, RhoA. Rac signaled to the nucleus through the Jun N-terminal kinase (JNK) cascade in this process. By generating point mutations in the effector loop of RhoA, we found that RhoA also signals to the nucleus during the establishment of ommatidial polarity. Nevertheless, Rac and RhoA activated transcription of distinct target genes. CONCLUSIONS: Rac is specifically required downstream of Dsh in the Fz pathway. It functions upstream or in parallel to RhoA and both signal to the nucleus, through distinct effectors, to establish planar polarity in the Drosophila eye.

Adaptor Proteins, Signal Transducing↗