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Biomedical subjects

W Richter

Publications and source records attributed to W Richter.

At least 181 records · Page 10Linked to original sources
PubMed1986

[Double-contrast pharyngography in surgically treated and/or irradiated oro- and hypopharyngeal malignant tumors].

The use of a double contrast technique in the oropharynx and hypopharynx is described and its diagnostic value following treatment is defined. By means of the double contrast pharyngogram, it is possible to demonstrate the pharyngeal mucosa and, post-operatively, the anastomosis. It is the only imaging method which demonstrates the course of swallowing and passage through the pharynx. By paying attention to physiological changes following treatment and taking account of early post-therapeutic appearances, it is possible to form a judgement concerning the peripharyngeal tissue. CT, however, is the method of choice for demonstrating an extraluminal tumour. In view of the ease of the method, double contrast pharyngography is the ideal radiological procedure for close follow-up of patients with malignant tumours of the pharynx.

Barium Sulfate↗
PubMed1985

Covalent coupling of proteins to erythrocytes by isocyanide. A new, sensitive and mild technique for identification and estimation of antibodies by passive hemagglutination.

A mild method for covalent coupling of protein-antigens to the surface of red blood cells (RBC) is described. The method is based on the formation of covalent bonds between aldehyde groups of oxidized RBC and amino or carboxyl groups of proteins in the presence of isocyanide. Very low concentrations of antibodies (8-30 ng/ml) could be detected in antisera with the specifically sensitized RBC as reagents in passive hemagglutination with no or very low non-specific agglutination.

Antibodies↗
PubMed1985

Freeze-fracture observations of Corynebacterium glutamicum: the occurrence of an outer membrane-like structure and the influence of temperature on the cytoplasmic membrane.

In order to elucidate temperature-dependent morphological changes in the cell envelope of the Gram-positive L-lysine-overproducing Corynebacterium glutamicum 9366 we carried out freeze-fracture investigations of native cells and studied their fatty acid composition. In addition to the cytoplasmic membrane C. glutamicum possesses at the periphery of the cell an additional fracture plane which is unusual in Gram-positive bacteria and is designated here as outer membrane-like structure. The fracture faces of this layer display a distinguishable appearance in several regions of the cell. Bacteria grown at various temperatures showed changes in the relation of the saturated to unsaturated fatty acids. We demonstrated that the cytoplasmic membrane was affected by these changes in the fatty acid composition.

Cell Membrane↗
PubMed1985

[Stress-inducible functional laryngospasm: differential diagnostic considerations for bronchial asthma].

Since 1974 about 30 cases of functional upper airway obstruction are known in literature. We report the findings in a 19 year old woman, who was free from any symptoms during rest. During exercise (swimming, jogging) she showed a loud inspiratory stridor, cyanosis, and dyspnoea. We found this stridor was induced by exercise or hyperventilation only (thread mill, CO2 rebreathing), and was caused by paradoxical vocal cord movement (fibreoptic laryngoscopy in local anaesthesia during CO2 rebreathing). All lung function parameters improved after inhalation of ipratropium bromide. We believe that it is important to investigate these patients during stridor attacks and without general anaesthesia. Otherwise it will be impossible, to get a correct diagnosis.

Adult↗
PubMed1985

Clinical investigation on the development of dependence during oral therapy with tramadol.

In a multicenter study 153 in- and outpatients suffering from severe pain were treated for three weeks with capsules containing 50 mg 1-(m-methoxyphenyl)-2-(dimethylaminomethyl)-cyclohexan-1-ol (tramadol, Tramal). The daily dosage was limited to 400 mg. At the end of the third week the patients received in a randomized double-blind manner 1.6 mg naloxone or saline (both i.m.) to evaluate the risk of developing dependence during the 3-week tramadol treatment (precipitation test). A total of 109 patients completed the trial. Development of tolerance was not observed as was evident from a constant daily tramadol dose associated with constant analgesia. The median net withdrawal scores for the naloxone treated group (mean = 0, Xmin = 0, Xmax = 13) and for the saline treated group (mean = 0, Xmin = 0, Xmax = 5) indicate absence of dependence. The outcome of the study thus suggests that tramadol under the conditions described does not induce dependence.

Administration, Oral↗
PubMed1984

[Ophthalmo-rhinosurgical decompression operation in malignant endocrine exophthalmus].

The thyroid metabolism has to be treated first. If this is not followed by regression of the exophthalmos, treatment with prednisone over a period of several weeks is indicated. If this does not result in permanent improvement, surgical decompression of the orbit is indicated, especially if the exposition of the cornea or compression of the optic nerve represent an imminent danger. In such cases surgical decompression is preferable to multiple series of prednisone or radiation treatment (Wright 1981, Trokel 1982). Both the Krönlein-Berke operation for resection of the lateral orbital wall as well as neurosurgical resection of the orbital roof have proved to be excellent for removal of correspondingly located orbital tumors; effective decompression of the orbit in malignant endocrine exophthalmos, however, cannot be achieved this way, as the temporal muscle and the brain, respectively, prevent protrusion of the swollen orbital tissues through these apertures. Resection of the orbital floor is somewhat more effective. The mucosa of the maxillary sinus can easily be moved by the protruding orbital tissues, resulting in a reduction in the size of the maxillary sinus. This decompression, however, is effective only in the anterior two-thirds of the orbit, while the optic nerve must be relieved from the pressure of the swollen muscles in particular in the posterior one-third of the orbit. The only effective way is to remove the medical orbital wall up to the tip of the orbit. Surgical techniques for this purpose have already been recommended, but appeared unsatisfactory from a rhinological point of view.(ABSTRACT TRUNCATED AT 250 WORDS)

Graves Disease↗
PubMed1984

New developments in nucleic acid hybridization.

Nucleic acid hybridization is widely used for scientific applications in specialized laboratories. This paper describes hybridization probes that can be prepared with less specialized equipment. A new indirect 'sandwich' hybridization test is described which allows the use of only one universally usable labelled probe for hybridization tests with specificities for various sequences. The use of different labels and hybridization techniques is also discussed and critically compared. For in situ hybridization, the usability of fixed and embedded materials is tested and evaluated.

DNA, Viral↗
PubMed1983

Nystatin- and amphotericin B-induced structural alterations of the erythrocyte membrane: importance of reduced ionic strength.

The effect of the polyene antibiotics nystatin and amphotericin B on the membrane structure of human erythrocytes has been investigated by freeze-fracture electron microscopy. Nystatin induces the same particlefree elevations on the erythrocyte membrane as already observed after treatment with amphotericin B. This structural alteration appears only in presence of an isotonic medium with reduced ionic strength. The dependence on the ionic strength supports the interpretation of these structures to be lipid domains.

Amphotericin B↗
PubMed1983

Adverse reactions to dextran in Sweden 1970-1979.

In a retrospective investigation of the period 1970-1979, 478 reports on cases of dextran-induced anaphylactoid/anaphylactic reactions (DIAR) were found. In 458 of these dextran was judged to be the causative agent. The number of units of dextran 40 and 70 used during this decade was 313 598 and 1 051 668, respectively. During the last five years, when reporting of severe adverse drug reactions was mandatory, the incidence of severe DIAR per unit administered was 0.013% for dextran 40 and 0.025% for dextran 70. The incidence of fatal DIAR was 0.003% and 0.004%, respectively. We found a male: female ratio of 1.5: 1 for all DIAR while for the most severe DIAR this ratio was 3: 1. The mean age of the patients was higher in severe than in mild DIAR. Allergic disease did not predispose for severe DIAR. Diabetes, cardiovascular and pulmonary diseases and chronic inflammation were more frequent among the patients who had suffered the most severe DIAR. 22 reactions were characterized by fever and/or shivering, and in 19 of these cases the reaction occurred after infusion of more than one unit of dextran. Severe DIAR occur after infusion of a few ml of dextran. Fatal DIAR during anaesthesia occurred almost exclusively in patients under spinal or epidural blockade. A favourable outcome of resuscitation in DIAR with cardiac arrest was possibly promoted by the infusion of large amounts of crystalloid fluids. We could not show that therapy with steroids, epinephrine or isoprenaline influenced the outcome. Fatal DIAR occurred even after infusion of only 0.5-1 ml of dextran, and we strongly advise against the use of "biological test-doses".

Aged↗
PubMed1983

Prevention of dextran-induced anaphylactic reactions by hapten inhibition. I. A Scandinavian multicenter study on the effects of 10 ml dextran 1, 15% administered before dextran 70 or dextran 40.

In an open prospective study the prevention of dextran-induced anaphylactic reactions (DIAR) by hapten inhibition was investigated in 29 252 patients. Forty-nine hospitals in Sweden, Norway and Finland participated in the study which was running for two years. Ten ml of dextran 1, 15%, (Promiten, Pharmacia AB, Uppsala, Sweden) with a weight average molecular weight of 1 000 dalton was injected intravenously two minutes before infusion of dextran 70 (Macrodex) or dextran 40 (Rheomacrodex). DIAR were graded according to severity from I to V. Six grade III and one grade IV reactions occurred, representing an incidence of severe DIAR of 0.024%. Compared to a large historical control material, preinjection of 10 ml of dextran 1 exerts a partially protective effect, but no statistical proof can be given. Consequently trials have been started with a 20 ml dose of dextran 1. Adverse reactions to the preinjection of 10 ml of dextran 1 were observed in 0.072%. These reactions were of a mild and shortlasting nature and considered to be of minor clinical importance.

Adolescent↗
PubMed1983

Prevention of dextran-induced anaphylactic reactions by hapten inhibition. III. A Scandinavian multicenter study on the effects of 20 ml dextran 1, 15%, administered before dextran 70 or dextran 40.

In an open, prospective multi-center study prevention of dextran-induced anaphylactic reactions (DIAR) was attempted by intravenous injection of 20 ml dextran 1, 15%, Mw 1000 dalton, (Promiten), two minutes before start of infusion of dextran 70 (Macrodex) or dextran 40 (Rheomacrodex). Of 34955 patients investigated, only one developed a severe DIAR of grade III (0.003%). The incidence of severe DIAR after preinjection of 20 ml dextran 1 is significantly lower than that after injection of 10 ml dextran 1 (p = 0.01), and is also markedly lower than that of a large Swedish historical control material (0.037-0.050%). The incidence of mild DIAR is not affected by dextran 1. Adverse reactions to dextran 1 of a generally mild and short-lasting nature were observed in 20 patients. It is recommended that patients who are going to receive dextran 70 or 40 are given a prophylactic i.v. injection of 20 ml dextran 1 before the first unit of clinical dextran to minimize the risk of severe DIAR.

Adolescent↗