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Biomedical subjects

D Hofmann

Publications and source records attributed to D Hofmann.

At least 127 records · Page 7Linked to original sources
PubMed1982

[Vertical and excentric stress in case of a defect on the fracture gap].

In order to compare the external fixator of the Arbeitsgemeinschaft für Osteosynthesefragen (AO) to different types of assembly of the Stuhler-Heise fixator (frame fixator, three-dimensional fixator, three-dimensional fixator with two screws of Schanz) with different spans (110, 140 and 190 mm), a vertical and excentric stress was exerted on a defect on the fracture gap. The comparable types of assembly of the AO fixator were lighter by 20% on an average. In two thirds of all assemblies, i.e. in 12 among 18 assemblies, the Stuhler-Heise device showed markedly better results of stability at the simulated fracture gap with respect to a vertical downward movement. In three assembly series there were identical results, in the other three series the AO device brought about better results. Under excentric stress, both fixator types showed considerable torsion movements from the horizontal line within the fracture gap. The differences between the two fixator systems found out for defects on the fracture gap will probably be significantly less important in case of compression osteosynthesis. This assumption will be verified by further examinations.

Bone Screws↗
PubMed1982

[Investigation about the stability of a fixateur-externe using a new screw nail (author's transl)].

Since former investigations showed that the 4.5 mm Steinmann-nails hitherto were the weakest part of fixateur-externe systems, we developed a screw nail with a shank thickness of 7 mm and a thread identical to that of the cortical screw developed by the Arbeitsgemeinschaft für Osteosynthese (Workshop Society for Osteosynthesis). By conducting experiments with a metal alloy (square tube made of aluminium) in cadaver bones, the bending stress of a frame assembly R and of a three-dimensional assembly with 2 Schanz-screws Z2S was examined with 4.5 mm Steinmann-nails as well as with screw nails. The systems mounted with the new screw nails bent considerably less than the other systems. The improvement in stability achieved by screw nails is relatively more significant for the external frame fixator and in cases of a defect at the fracture gap than for the three dimensional fixateur externe with 2 Schanz-screws and in case of a compression at the fracture gap.

Bone Screws↗
PubMed1982

Instillation of fibrinolytic enzymes in the treatment of pleural empyema.

Acute pleural empyema which is not amenable to pleural puncture or closed thoracic drainage should be treated operatively by decortication or, in persistent cavities, by open thoracostomy drainage. In the last 2 years we have instilled 500,000 IU of fibrinolysines (streptokinase and streptodornase) per day into the pleural cavity of 27 patients with pleural infections requiring closed intrapleural drainage. By means of this treatment, pus and fibrinous membranes are liquefied and necrotic tissue is discharge. Therapeutic success is indicated by considerably increased fluid drainage about one hour after instillation. This therapy was performed for an average of 5 days. In 12 patients (44%) pleural empyema could be cured. In the other 15 cases decortication, and in 3 of them open thoracostomy drainage, was necessary. In our opinion intrapleural instillation of fibrinolytic enzymes should be added to the well-recognized method of treatment of pleural empyema, although not replace them.

Acute Disease↗
PubMed1981

[Endolymphatic stromal myosis, a rare semimalignant tumour (author's transl)].

The rarely occurring disease of endolymphatic stromal myosis is discussed by means of an impressive case. The cells of this semimalignant tumour resemble those of the endometrium, but it is not clear whether this tumour can be derived histogenetically from the endometrium or from the cells of the duct of Müller (ductus paramesonephricus) or from pericytal cells. The histological pattern of the tumour, which is characterized by the uniformity of small spindle-like oval cells without remarkable mitotic activity, and by a lack of atypical criteria, does not permit any prognosis in respect of its clinical behaviour. According to the rare references in literature, the clinical course is usually protracted with occasional occurrence of metastases and relapses. The therapy consists of radiotherapy and administration of progesterone. The case described in this article is a clinically malignant one because of disseminated metastases and relapse following initially successful therapy.

Adult↗
PubMed1980

[Alloplastic tracheal prosthesis with biocarbone. A study of animal experiments (author's transl)].

Animal experiments have shown bicarbone to be a suitable material for alloplastic tracheal replacement. So far survival rates have been limited by connective tissue stenoses and by loosening prostheses. Although the transplants are not lined by bronchial mucosa, the movement of secretions is not seriously impaired due to the smooth surface. It is still a matter of speculation as to whether modifying the suture technique with a more elastic transistion from the trachea to the prosthesis would produce better results.

Animals↗
PubMed1980

[Investigations of stability with the fixateur externe during strain of bending. Vertical and eccentric strain during compression of the fracture line and while the distance of support is changed (author's transl)].

The Fixateur externe was investigated under vertical and eccentric load when the fracture line was compressed and the distance of support was changed. Three kinds of mounting were used: R (Fixateur externe as frame), Z (three dimensional Fixateur externe) and Z2S (three dimensional Fixateur externe with two screws according to Schanz). If the distance of outer support was increased, the stability became greatly reduced. A compression increased the stability around the fracture line and on the free end of the system. A compression force of 10 kp at the fracture line yielded the greatest increase in stability. If in case of the methods R and Z, the compression was increased beyond 70 kp, there resulted even an instability, which depended on the distance of support. The most stable method of mounting was the three-dimensional Fixateur externe with two screws according to Schanz. The stability was compared if there was either a defect or a compression at the line of the fracture: there resulted a strikingly increased instability, if the distance of support was increased. The compression made it possible to compensate partly for the loss of stability.

Biomechanical Phenomena↗
PubMed1980

Osteoclastoma-like giant cell tumor of the lung.

Rare extraskeletal locations of osteoclastoma-like giant cell tumors have been found in thyroid, pancreas, breast, skin and heart. In our case, a 40-year-old male patient, such a tumor was found in the left upper lobe bronchus with atelectasis due to bronchial obstruction. Upper lobe resection was done. As far as we know, this has not been reported.

Adult↗
PubMed1980

[Advantages of a new thoracic drainage unit with double sealing].

The paper deals with the application of a new 'Four-Compartment Drainage System' with double-sealing in 20 patients having lung parenchyma resections, explorative thoracotomies, and pneumothorax. This drainage system has an advantage over conventional intercostal drainage in as much as it prevents tension pneumothorax in leakage of the lung and suction failure. The closed system avoids bacterial contamination of the pleural space.

Drainage↗
PubMed1980

[Ileocecal mucosal prolapse].

Knowledge of normal and pathological anatomy and the radiological picture of the ileocecal valve is very important to avoid false interpretation of polyp-like findings in the cecum. Radiologically, ileal prolapse can pose as a cecal polyp. The radiological diagnosis, large 'cecal polyp' was not confirmed intraoperatively in the case presented.

Cecal Neoplasms↗
PubMed1978

[Results of immunotherapy in 244 children with asthma or allergic rhinitis (author's transl)].

The results of immunotherapy in 244 children with asthma or allergic rhinitis have been evaluated by means of a questionaire directed at the parents. 86,9% of the children showed improvement. Additional information has been obtained about the side-effects of therapy--2,9% regularily showed dyspnoea--, the severity of symptoms before treatment and the influence of age on the above mentioned parameters. The results are discussed, compared with similar studies in adults and possible consequences for future diagnostic measures and therapy are proposed.

Adolescent↗
PubMed1977

[Rupture of the uterus (author's transl)].

There have been made investigations at 142 Patients, who have delivered after earlier operations of the uterus. At 10 cases (7%) there occured a rupture in the scar. At 6 cases the rupture was detected by postnatal manual control of the cavum uteri. At 4 cases the rupture was found whilst the repeated caesarean section. The letality of mothers and children was 0. It is demanded, to give severe indication for caesarean section and not to perform it in all concerned cases. It is necessary to keep the concerned women under surveillance in late pregnancy and under delivery. If spontaneous delivery is prolongated or complicated secondary section is to be performed.

Breech Presentation↗