Biomedical subjects

U Schmidt

Publications and source records attributed to U Schmidt.

At least 163 records · Page 9Linked to original sources

PubMed1996

Fractures of the odontoid process in small children: biomechanical analysis and report of three cases.

Odontoid "fractures" in young children typically involve the cartilaginous plate (synchondrosis) that separates the odontoid process from the body of the axis; 58 cases have been described in the literature. We report two cases in which 2-year-old children were involved as backseat passengers in head-on motor vehicle accidents, both were restrained by four-point child's seat harnesses. A biomechanical investigation was carried out using simulation in a real car crash test with a child dummy. This revealed that head-on collisions with a speed absorption of at least 40 km/h are the typical mechanism of injury in children under the age of 3 years involved in motor vehicle accidents. Shearing force is all that is necessary to explain the dens fracture. Both children were immediately symptomatic, and the diagnosis was obvious on radiographs. Neither child had neurological deficit, which correlates well with the literature, where neurological injuries were found only in conjunction with head injuries. After closed reduction, both cases were initially treated conservatively with halo and plaster vest for 12 weeks. In one case, in which the anterior dislocation was less than the diameter of the odontoid shaft, eventless healing occurred. In our second case, despite an anatomic reduction, the odontoid fracture failed to unite. After a temporary posterior fixation of C1/C2 we reamed the synchondrosis from anterior and performed autogenous bone grafting. The posterior fixation wire was removed after 5 months. In contrast to the literature, we do not recommend a permanent posterior fusion of C1/C2. Our two young patients were both followed-up for more than 3 years. Clinical and radiological examination at final follow-up was normal with no signs of atypical growth of the odontoid. In cases of major dislocation with greater instability we recommend primary open reduction and osteosynthesis with appropriate implants. This was done in a third case: a 1 1/2-year-old boy who fell down the stairs and sustained a head injury and an unstable lesion of the odontoid with subtotal paraplegia. The odontoid was fixed with two screws.

Biomechanical Phenomena↗

PubMed1996

[Cutaneous malacoplakia in a patient with psoriasis vulgaris].

A 58 year old patient suffering from psoriasis vulgaris had typical erythematous, scaly plaques for 20 years. In addition, an erosive, therapy-resistant plaque was found in the perianal region. A biopsy was taken to exclude malignancy; it showed intracytoplasmic Michaelis-Gutmann-bodies as a marker for malakoplakia, which rarely occurs in the skin. In further electron microscopic investigation, intracytoplasmatic bacteria could be demonstrated. An underlying malignancy or chronic renal insufficiency with immunosuppression were not found in this patient; both are often associated with malakoplakia.

Anal Canal↗

PubMed1996

[Analysis of implantation-induced nail deformation and roentgen morphometric studies as the principle for an aiming device for distal interlocking nailing without roentgen image intensification].

While working to develop a distal locking device, we analyzed distal nail position with reference to nail deformation and a radiographic-morphometric investigation. The amount and the direction of implant deformation in unslotted stainless steel unreamed tibial nails (Synthes) were analyzed. Measurement of implant deformation (3 translations, 3 angles) in the center of the distal transverse locking hole was performed with a 3D magnetic motion tracker system before and after nail insertion. Unreamed tibial nails (diameter 8 mm, n = 10; diameter 9 mm, n = 10) were inserted in paired human cadaver tibiae. The results showed lateral translations of -4.5 +/- 3.5 mm (mean and standard deviation, range 14.3 mm) and dorsal translations of -7.8 +/- 5.8 mm (mean and standard deviation, range 19.2 mm). Rotational deformations around the longitudinal axis of the nail were 0.3 +/- 0.7 degree (mean and standard deviation, range 2.4 degrees). The results showed, that a simple aiming arm, mounted on the proximal nail end, alone or even in combination with a large working channel (e.g. 10 mm in diameter), was not adequate to the aiming process. A radiographic-morphometric analysis was subsequently performed in 40 tibiae after experimental (n = 20) or clinical (n = 20) implantation of nails 8 mm and 9 mm in diameter. These measurements showed a relatively constant distance between the upper distal transverse hole and the anterior aspect of the tibia (average 12.3 mm and only a narrow range (7.6 mm). These data were the basis for the development of an aiming technique that exploits the relatively constant distance between the distal nail hole and the anterior aspect of the tibia. This aiming device is set at a distance of 12.3 mm from the anterior cortex, and the fine tuning is finally resolved by the use of a "working channel' 10 mm in diameter.

Biomechanical Phenomena↗

PubMed1996

[Long-term outcome of 57 patients after ventral interbody spondylodesis of the lower cervical spine].

In this retrospective study we present the long-term results in 89 patients who underwent anterior interbody fusion of acute cervical spine injuries in our institution between 1972 and 1983. There were 23 dislocations, 50 fracture-dislocations and 16 burst fractures without significant posterior lesions. Only 20 patients showed no neurologic symptoms. In all 79 patients who were treated initially in our trauma department, closed reduction was performed as soon as possible. No aggravation of the neurologic conditions by this manoeuvre was observed. The mean time between injury and operation was 7 days (range 0-110 days). In 79 patients an H-plate or one-third-tubular plate was used, and in 10 patients fusion was performed only by bone grafting according to the technique of Robinson [40]. Severe complications, i.e. persistent instability with kyphosis or sagittal dislocation, were found in only 2 of these 10 patients secondary to technical problems. The radiologic results demonstrated a high fusion rate, with fusion in 78 out of the 79 patients. Of the 79 patients treated with plate spondylodeses, 7 devices had to be removed without loss of correction: 6 owing to loosening and 1 to breakage of the plate. Only in one additional case after early hardware removal because of loosening was a loss of correction detected. Of the original 89 patients, 17 had died of causes unrelated to the operation. The mean age of the surviving 72 patients at the time of injury was 36 years (14-83 years). A further 15 patients were lost during follow-up, so that 57 (79%) could be included in the study with a mean follow-up of 11 years, 9 months (10-19 years). The functional results were as follows: Active range of motion was limited between 25 and 50%. 40 patients had no pain at rest, 38 only during motion without need for treatment. A significant correlation between pain and fused segments could not be found. Spontaneous fusion and spondylophytes in adjacent motion segments were seen in 27 patients, again without significant correlation to residual pain. No hypermobility of adjacent motion segments in functional X-rays was seen. 46 patients returned to their former work, 7 were not able to work again secondary to the injury, 4 patients received old-age pension. Improvement of the neurologic deficits in the 37 symptomatic patients was observed in 30 cases (81.1%) according to the "Sunnybrook Cord Injury Scale" [49]; according to the ASIA Neurological Impairment Scale [5] 25 (67.6%) of them improved of at least 1 degree. No correlation could be found between the interval injury to operation and neurologic improvement. With regard to the early stage of the procedure of anterior interbody fusion for traumatic lesions this study shows promising data with high fusion rates and low morbidity, especially for the combination with plate fixation. Further improved within the last 12 years this method offers an excellent alternative for operative treatment of most acute lower cervical spine injuries. Using devices which are not angle stable, special attention should be given to precise bicortical screw fixation.

Adolescent↗

PubMed1996

Analysis of chromium(III)-fluoride-complexes by ion chromatography.

A method for the ion chromatographic separation of cationic CrF(x)-species in aqueous acidic solutions with photometric detection is described. CrF(3)-, CrF(+)(2)- and CrF(2+)-species can be separated on a commercial cation-exchange column using HCl/2,3-diaminopropionic acid (DAP) as eluent. The chromium(III)-complexes are converted with 2,6- pyridinedicarboxylic acid (PDCA) into the violet [Cr(PDCA)(2)](-)-complex at temperatures >90 degrees C by post-column derivatisation for the subsequent spectrophotometric detection at lambda=335 nm. Iron- and nickel-ions do not disturb the determination even in concentrations higher than those of the chromium (III)-ions.

Journal Article↗

PubMed1996

Degradation of prochloraz and 2,4,6-trichlorophenol by environmental bacterial strains.

Eight bacterial isolates from enrichment with 2,4,6-trichlorophenol (TCP) as sole carbon source were tested for their potential to degrade prochloraz. None of them could grow on prochloraz. Strain C964, identified as Aureobacterium sp., effectively reduced the fungitoxic activity of prochloraz in a bioassay and degradation was confirmed by HPLC. Two other isolates, strain C611 and C961, using TCP as a carbon source, belong to the beta subclass of the proteobacteria and presumely degrade TCP via 2,4-dichlorohydroquinone and hydroxyhydroquinone as indicated by oxygen-consumption tests.

Bacteria↗

PubMed1996

Activation of dopaminergic D1 receptors promotes morphogenesis of developing striatal neurons.

The early dopaminergic input from the midbrain may play an important role in the development of the basal ganglia. We therefore investigated whether and how dopamine affects the morphogenesis of striatal target neurons. Dissociated cell cultures of embryonic day 17 rat striatum were raised for seven days. Cells were then incubated with dopamine or various receptor-specific ligands for 1 h. At various times after termination of the treatment, cells were immunostained for growth-associated protein-43. Morphological parameters including numbers of growth cones, length of neurites, number of bifurcations, and neuronal soma size were assessed by means of a computer-based morphometric device. Treatment with dopamine in low concentrations as well as with the D1-like receptor agonist SKF 38393 increased the numbers of growth cones and neurite length and arborization. The morphogenetic effect took several hours to evolve and remained stable for at least 24 h. It could be blocked by the D1-like receptor antagonist SCH 23390 or by cycloheximide but not by pretreatment of the cultures with tetrodotoxin. The D2-like receptor agonist quinpirole had no effect on the morphological parameters and did not contribute to that of SKF 38393. Dopamine and SKF 38393 but not quinpirole also induced an increase in the number of neurons immunoreactive for Fos-like proteins. However, this effect was restricted to growth-associated protein-43-negative neurons. This is the first observation of a positive regulatory effect of D1-like receptors on neuronal morphogenesis. We conclude that the changes reflect true differentiation rather than short-term modulation of cellular properties and that c-fos induction is not an obligatory step in the transduction pathway coupling D1-like receptors to neurite outgrowth. Our results suggest that the differentiation of embryonic striatal neurons is promoted by the dopaminergic nigrostriatal projection through D1-like receptors.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗

PubMed1996

-Cytokine level in malignant ascites and peripheral blood of patients with advanced ovarian carcinoma-.

The concentrations of various cytokines were examined by ELISA in blood and in ascites from 14 patients with advanced ovarian cancer (stage IV). The control group consisted of 6 patients with benign gynaecological disorders. Compared with patients with benign gynaecological disorders, ascites and/or plasma of patients with ovarian cancer showed significantly higher levels of IL-6, IL-8, IL-10, TNF-alpha, and sIL-2R. There were no increases of IL-1 alpha, IL-1 beta, IL-2, IFN-gamma, and sCD14 levels. The possible pathogenetic significance of cytokines in ovarian cancer is discussed.

Adult↗

PubMed1996

The influence of C1-esterase inhibitor substitution on coagulation and cardiorespiratory parameters in an endotoxin-induced rabbit model of hypercoagulability.

In a short-time model of endotoxin-induced (lipopolysaccharide from Escherichia coli, 120 micrograms kg-1 i.v.) hypercoagulability in rabbits, the therapeutic effects of C1-esterase inhibitor (C1I) substitution (bolus 400 U kg-1 i.v. followed by continuous infusion of 400 U kg-1 4 h-1 i.v.) were studied. When compared to endotoxin-challenged untreated animals, C1I substitution significantly stabilized mean arterial pressure (p < 0.01), increased central venous oxygen saturation (p < 0.05), prevented the decrease of antithrombin III (p < 0.05), and reduced fibrin deposition in the microcirculation of the liver and the lungs to approximately 30% of that observed in the untreated animals (p < 0.01). Although C1I substitution did not reduce systemic procoagulant turnover, the improvement of blood pressure and blood flow and local inhibitory actions in the coagulation and complement cascade prevented fibrin deposition in the microcirculation of vital organs. This study supports the beneficial role of C1I substitution during early disseminated intravascular coagulation.

Animals↗

PubMed1996

Compliance with a self-care manual for bulimia nervosa: predictors and outcome.

Self-directed treatment has been shown to be effective in the treatment of bulimia nervosa. This paper shows that compliance with a manual is related to outcome. Forty per cent of high compliers achieved full remission after eight weeks with a manual, compared with only 5 per cent of low compliers. Furthermore, patients with greater weight and shape concerns were less likely to use a manual while those with a longer duration of illness were more likely to use it.

Adult↗

PubMed1996

Sequential treatment for bulimia nervosa incorporating a self-care manual.

BACKGROUND: The aim of this study was to evaluate the effectiveness of a stepped care approach to the treatment of bulimia nervosa: a self-care manual followed, if necessary, by a course of attenuated cognitive behavioural treatment (CBT) in comparison with standard CBT. METHOD: One hundred and ten patients, presenting at a tertiary referral centre with ICD-10 bulimia nervosa or atypical bulimia nervosa, were randomly assigned to one of two treatment conditions; a) a sequential treatment group: 8 weeks with a self-care manual followed by up to eight sessions of CBT (if still symptomatic) or b) 16 sessions of CBT. RESULTS: Bulimic symptoms improved significantly in both groups with no significant differences between the two groups on any of the measures at the end of treatment or at 18 months follow-up. At end of treatment 30% (95% CI: 18-46%) of the sequential group and 30% (95% CI: 17-47%) of the standard treatment group were free from all bulimic symptoms. Sixteen of those in the sequential group improved significantly with self-care and did not require additional treatment. The median number of sessions taken by the sequential group was three (95% CI: 0-6). At 18 months follow-up 40% (95% CI: 23-59%) of the sequential group and 41% (95% CI: 25-59%) of the CBT group were symptom free. CONCLUSIONS: A sequential approach to the treatment of bulimia may be as effective as standard CBT and can considerably reduce the amount of therapist contact required.

Adolescent↗

PubMed1996

Combined preoperative chemotherapy and radiotherapy in patients with locally advanced esophageal cancer. Interim analysis of a phase II trial.

PURPOSE: The prognosis of patients with locally advanced esophageal cancer (LAEC) remains poor when treated with local modalities. An intensive preoperative program with chemoradiotherapy was used to evaluate the curative resection rate, pathologic response, and survival of patients with LAEC. PATIENTS AND METHODS: Ninety patients with LAEC were treated preoperatively with chemotherapy (three courses of fluorouracil, leucovorin, etoposide, and cisplatin [FLEP]) followed by concurrent chemoradiotherapy (one course of cisplatin plus etoposide in combination with 40 Gy of radiation). Transthoracic esophagectomy was performed 4 weeks after the end of radiation. RESULTS: Seventy-two patients were included in this evaluation. Forty-four (61%) underwent a complete tumor resection, and 16 (22%) had no tumor in the resected specimen (pathologic complete response [PCR]). The operative mortality rate was 15%. At a median follow-up time of 22 months (range, 12 to 41), the median survival duration of all 72 patients was 17 months (range, 1 to 41+). The calculated survival rates at 3 years were 33%, 42%, and 68% for all patients, patients after complete resection, and patients with PCR, respectively. CONCLUSION: This combined treatment modality is active in LAEC, with a PCR in 33% of the patients undergoing surgery. The results appear improved compared with those reported with surgery alone, by approximately doubling the 3-year survival rate. The high efficacy of preoperative chemoradiation warrants evaluation of the role of surgery in LAEC.

Adenocarcinoma↗

PubMed1996

T-cell-rich B-cell lymphoma--a distinct clinicopathologic entity?

T-cell-rich B-cell lymphoma is a particular variant of large B-cell lymphomas with the morphological hallmark of a small number of large neoplastic B-cells scattered in between a dense background of reactive T-lymphocytes, while histiocytes may be admixed in variable numbers. In the typical case, the neoplastic population resembles large germinal center cells including cells similar to the L+H-variants of Reed-Sternberg cells. The immunophenotype of these tumour cells is L26 + Leu-M1-BerH2-. Apart from these unifying features, the individual cases constitute a broad spectrum of various growth patterns, so that a multiplicity of different relations to other types of malignant lymphomas are discussed in the literature. This occurs to such an extent that it may be doubted, that one deals with a distinct and separate lymphoma entity. Moreover, a close relationship exists between T-cell-rich B-cell lymphoma and lymphocyte predominant Hodgkin's disease, because there are striking similarities between the two, and, in addition, coexistence of T-cell-rich B-cell lymphoma with Hodgkin's paragranuloma has been reported. It, therefore, seems conceivable that T-cell-rich B-cell lymphoma represents a developmental stage of lymphocyte predominant Hodgkin's disease. Be that as it may: There is no doubt that, presently, the nosological position of T-cell-rich B-cell lymphoma is unsettled and still remains to be clarified.

Diagnosis, Differential↗

PubMed1996

[CT-guided punctures in the area of the spine. The "fluorotechnique" as localization method].

The increased anatomical resolution of the Computed Tomography allows the localized excision of tissue malformation even less than 5 mm in diameter. Within difficult areas of the body, e.g. the spine, it is possible to reach intra- as well as extraosseous lesions with high accuracy. Results and technique of puncture are reported in 31 patients with unclear diagnosis or therapy (Neurolysis). In 24 cases diagnosis was established or therapy was successful, in 2 cases the result was false negative. In 5 cases the tissue was non diagnostic. According to the low number of complications (n = 1) a repeated study would have been possible.

Adolescent↗

PubMed1996

Dilated cardiomyopathy in turkeys: an animal model for the study of human heart failure.

Many animal models of heart failure developed to date do not mimic pathophysiologic changes recently described in the failing human myocardium. In human endstage heart failure, abnormalities in morphology, electromechanical coupling, and myocardial energetics have been described. However, studies of human myocardium are limited by lack of appropriate controls, the fact that all patients have endstage heart failure, and exposure of patients to different therapeutic regimens. In contrast to many animal models, the myopathic turkey heart (i.e., idiopathic dilated cardiomyopathy or furazolidone-induced cardiomyopathy) is similar to the myopathic human heart in terms of gross morphology, myocardial energetics, muscle physiology myofilament properties, Ca2+ metabolism, and the beta-receptor-adenylyl cyclase signaling system.

Actin Cytoskeleton↗

PubMed1996

Mutations of the two-nucleotide bulge of D5 of a group II intron block splicing in vitro and in vivo: phenotypes and suppressor mutations.

Domain 5 (D5) is a highly conserved substructure of group II introns that is essential for catalysis of both steps of the splicing pathway. Here we studied the effects of mutations of the conserved 2-nt bulge in the binding and catalytic functions of D5 of intron aI5gamma of yeast mitochondrial DNA. Sequence variants of the 2-nt bulge reduced the rate of self-splicing somewhat. Deletion of one or both bulge nucleotides inhibited splicing more than 10(4)-fold, whereas mutants with a 3-nt bulge were much less debilitated. A novel allele with a symmetrical internal loop in place of the bulge self-splices nearly as actively as the control. Trans-splicing assays of D5 function showed some mutations primarily affect the catalytic function of D5, whereas others chiefly affect its binding function. Representative alleles were transformed into mtDNA and each inhibited splicing and respiratory growth. Pseudo-revertants included suppressor mutations nearby in D5 and one mutant yielded a dominant nuclear suppressor. These experiments provide new evidence that the D5 bulge is crucial for D5 binding and catalysis. It is possible that the bulge bends the D5 helix and that the extent of bending is especially important for D5 binding. The presence and exact nature of the bulge is also likely to have local structural consequences (besides bending) that influence the participation of specific backbone groups in binding and catalysis.

Base Sequence↗

PubMed1996

[Is hemithyroidectomy as standard intervention of suspicious puncture cytology justified?].

Since 1989, the operative treatment of 65 patients with suspicious fine-needle aspiration cytology of solitary thyroid nodules has been decided on individual clinical criteria such as the patient's history and morphology of the remaining thyroid tissue. Finally, 9 carcinomas were seen amongst 37 hemithyroidectomy specimens, out of 28 resected thyroid glands 2 were papillary microcarcinomas, whereas the others were benign specimens up until now. Despite a comparatively low perioperative morbidity of the hemithyroidectomy, we see thyroid resections justified in cases of suspicious cytology.

Adenocarcinoma, Follicular↗

PubMed1995

Unchanged protein levels of SERCA II and phospholamban but reduced Ca2+ uptake and Ca(2+)-ATPase activity of cardiac sarcoplasmic reticulum from dilated cardiomyopathy patients compared with patients with nonfailing hearts.

BACKGROUND: The aim of the present study was to investigate whether Ca2+ uptake into the sarcoplasmic reticulum (SR) is altered in failing human myocardium resulting from dilated cardiomyopathy. METHODS AND RESULTS: Ca(2+)-ATPase (SERCA II) activity and Ca(2+)-dependent 45Ca2+ uptake (oxalate supported, steady state) in isolated vesicles from the SR (VSR) and in crude membrane preparations (CSR) (free Ca2+, 0.01 to 100 mumol/L) from nonfailing (donor hearts, n = 13) and terminally failing (heart transplants, dilated cardiomyopathy, n = 17) human myocardium were studied. In the same hearts, protein levels (Western blot analysis) and mRNA levels (Northern blot analysis) of SERCA II and phospholamban were measured. Increasing concentrations of Ca2+ were followed by an increased Ca(2+)-ATPase activity and Ca2+ uptake. Ca2+ uptake activity and Ca(2+)-ATPase activity in CSR preparations from failing myocardium were significantly reduced compared with nonfailing hearts (Ca(2+)-ATPase, 163 +/- 8 and 125 +/- 7 nmol ATP/mg protein per minute for nonfailing tissue and failing tissue in New York Heart Association [NYHA] class IV, respectively; Ca2+ uptake, 7.1 +/- 0.8 and 3.5 +/- 0.3 nmol/mg protein per minute in CSR from nonfailing and NYHA class IV hearts, respectively P < .05). In contrast, no significant difference was measured in VSR. In the same preparations (CSR and VSR), both SERCA II and phospholamban levels (Western blot technique with monoclonal antibodies) were unchanged in failing compared with nonfailing tissue. mRNA expression relative to GAPDH mRNA for SERCA IIa and for phospholamban was significantly reduced in failing human myocardium (P < .05). CONCLUSIONS: These findings provide evidence that in failing human myocardium caused by dilated cardiomyopathy, protein levels of SERCA II and phospholamban are unchanged even though mRNA levels for SERCA II and phospholamban and the SERCA II function are reduced compared with nonfailing myocardium.

Adenosine Triphosphatases↗