Biomedical subjects
Publications and source records attributed to A Scherer.
Myxoid liposarcoma is a rare soft tissue tumour. The authors report one case of retroperitoneal tumour discovered during pregnancy, which recurred after initial surgery. Clinical features, clinical course and prognosis of this disease are examined together with management procedures.
From 1982 to 1992 we treated 66 talar injuries at our institution, 44 of which were central fractures (25 talar neck fractures, 17 corpus fractures, 1 comminuted fracture and 1 complete dislocation of the intact talus). In 77% of patients additional injuries were present; 34% were polytraumatized. In 41 patients (93%) clinical and radiological follow-up was possible after an average of 6.3 years. All displaced fractures were treated by open reduction (84%) and, usually, screw fixation, 41% of these within 6 h after the accident. Only 1 required an osteotomy of the medial malleolus, and in 4 a cancellous bone graft was performed. Non-displaced fractures were treated by plastering and partial weight-bearing for an average of 3.1 months. This regime made it possible to contain the rate of aseptic necrosis of the talar body at 12%. The infection rate was 5%. Degenerative changes of the tibiotalar and subtalar joints were seen in 34%. Although there were no cases of non-union and only 2 of malunion, we observed only 6 patients (15%) with complete functional recovery (painfree, normal gait, full professional and recreational activities). A good result (start-up pain, slight limp) was seen in 15 (37%), and a fair result (pain on walking, but normal gait) was achieved in 7 (17%). We observed 13 patients (32%) who had pain on walking and/or at rest and a definite limp at follow-up examination. The average time off work was 8.7 (2.3-26) months. A poor result was associated with additional injuries and subtalar osteoarthritis.(ABSTRACT TRUNCATED AT 250 WORDS)
The values obtained from two different macro EMG methods were compared, and found to be different. Normally, macro electromyography (EMG) is performed with a modified single fiber (SF) needle using the SF potential as a trigger; a new method recommends a modified concentric needle and triggers on the concentric EMG signal. The concentric macro EMG has a 40% to 50% smaller amplitude and area values than data obtained with a SF macro EMG needle. The different values are the result of variant spatial relationships of the respective needles to the motor unit under study, and may be due to a recruitment-dependent bias resulting from different trigger properties of the two methods. The concentric macro EMG needle can be used to estimate motor unit size, to scan the unit, and to investigate its different concentric EMG signals.
The X-ray structures of the guanine nucleotide binding domains (amino acids 1-166) of five mutants of the H-ras oncogene product p21 were determined. The mutations described are Gly-12----Arg, Gly-12----Val, Gln-61----His, Gln-61----Leu, which are all oncogenic, and the effector region mutant Asp-38----Glu. The resolutions of the crystal structures range from 2.0 to 2.6 A. Cellular and mutant p21 proteins are almost identical, and the only significant differences are seen in loop L4 and in the vicinity of the gamma-phosphate. For the Gly-12 mutants the larger side chains interfere with GTP binding and/or hydrolysis. Gln-61 in cellular p21 adopts a conformation where it is able to catalyze GTP hydrolysis. This conformation has not been found for the mutants of Gln-61. Furthermore, Leu-61 cannot activate the nucleophilic water because of the chemical nature of its side chain. The D38E mutation preserves its ability to bind GAP.
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The catalytic domain (amino acid residues 1 to 166) of the human ras-oncogene product p21 complexed with the GTP analogues beta,gamma-imido-GTP (GMPPNP), beta,gamma-methylene-GTP (GMPPCP), and guanosine-5'-(gamma-thiotriphosphate) (GTP gamma S) have been been crystallized. Crystals of the GMPPNP and GMPPCP complexes are well suited for high resolution X-ray crystallography. They belong to space group P3(1)21 (or its enantiomorph P3(2)21) with unit cell axes a=b=40.3 A and c = 162.2 A.
Aleurodiscal, an antifungal antibiotic has been isolated from mycelial cultures of Aleurodiscus mirabilis (Berk. & Curt.) Höhn. It causes abnormal apical branchings of Mucor miehei hyphae at very low concentrations. The structure and absolute configuration of the antibiotic has been determined by a single crystal X-ray analysis and hydrolysis to D-(+)-xylose. Aleurodiscal is a hydroxysesterterpene aldehyde beta-D-xyloside with a novel carbon skeleton.
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Periodic sound-pressure time functions with frequency components below 50 Hz were used to measure within their period (a) the temporal course of masking, called a masking-period pattern (MPP), and (b) the temporal course of suppression of delayed evoked otoacoustic emissions, called a suppression-period pattern (SPP). Three different time functions were used: an alternating Gaussian impulse, its first integral, and its second integral. In each case, the course of the SPP is a mirror image of that of the MPP: Small masking corresponds to small suppression, while strong masking coincides with almost total suppression. Since otoacoustic emissions are assumed to have their origin in the inner ear, it can be argued that simultaneous masking, an effect including central processing, is very strongly based on peripheral processes located in the cochlea. Both MPP and SPP are closely related to the second derivative of the sound-pressure time function.
The literature data about the distribution of mononuclear cells in Crohn's disease are still contradictory. In 50 surgical C.D. patients, clinically classified corresponding to the Crohn's Disease Activity Index (CDAI), the T-lymphocytes and their subsets helper-T- and suppressor-T-lymphocytes (TH/TS) were therefore determined by use of monoclonal antisera, the B-lymphocytes by F(a b)-anti human Ig and the macrophages by uptake of latex microparticles. 37 C.D. patients underwent diseased bowel removal. Blood was drawn from the Crohn-draining mesenteric vein for analysis. Further investigations were performed at the 10th p. op. day as well as after an average period of 7 months (2-18). In comparison the mononuclear cell distribution was examined in 14 patients suffering from chronic osteitis and in 14 patients without any inflammatory disease as controls. C.D. patients showed preoperatively a significantly decreased TH/TS-ratio as well as a significantly increased proportion of macrophages. There was a lymphocytopenia in the peripheral differential blood count. Whereas the distribution of mononuclear subpopulations in the mesenteric blood was identical to the peripheral blood, significant lymphocytosis in the differential blood count of mesenteric blood was found. On the 10th p. op. day the TH/TS-ratio rose almost up to normal, which continued during the follow-up period. The macrophages remained constantly increased in all stages of investigation although during the follow-up none of the patients had signs of disease recurrence. Osteitis patients showed a similar distribution as C.D. patients, even if the changes compared to controls were not as distinct. The proportion of B-lymphocytes was the same in all groups examined. The individual TH/TS-ratios and proportions of macrophages of C.D. patients did not correlate to their clinical data. The changes within the T-cell-subpopulations seem to reflect less M. Crohn's disease itself than its inflammatory complications. Further studies have to be undertaken concerning the impact of the constant increase in macrophages, even after resection of the Crohn bearing bowel segment.
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PURPOSE: The aim of the study was to evaluate by MRI the course of aseptic osteonecrosis (AON) after chemotherapy in children with different malignancies. MATERIAL AND METHODS: Retrospective analysis of 72 MRI studies in 20 children (age: 3.2-18.4 years) presenting with AON after chemotherapy. 8 children were treated exclusively with relief of weightbearing structures, whereas 12 children were additionally treated with hyperbaric oxygen therapy (HBO). Within a range of 3-76 months each patient received 1-6 follow-up exams. The acquired series included multi planar spin-echo as well as fatt-suppressed inversion recovery sequences. The MRI examinations were evaluated by a point-score system (1-6) by two radiologists. RESULTS: AON was most commonly seen in the pedal bones (26.4%), in the hip (23.6%), and in the knee joints (19.4%). Initial findings revealed an average score of 3.1 points. Based upon these initial findings, subsequent analyses show a statistically significant (p < 0.05) score increase of 0.6 score-points. For the observed intervals a: < 6 months, b: 6-12 months, and c: > 12 months the mean scores were: a: 3.3, b: 3.7, and c: 4.5 points. During the observed time period 5 patients were surgically treated in the affected bone areas. CONCLUSION: The majority of chemotherapy associated AON which initially present with advanced findings showed in MRI a progression with frequent destruction of the joint surface over their further course. More discrete forms of AON, especially osteoedema, can be positively influenced by conservative therapy.