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Biomedical subjects

W Schroeder

Publications and source records attributed to W Schroeder.

At least 55 records · Page 3Linked to original sources
PubMed1982

Primary structure of the C-terminal cyanogen bromide fragments II, III and IV from bovine brain proteolipid-apoprotein.

Purified lipophilin from bovine brain white matter was reductively carboxymethylated and then cleaved by cyanogen bromide into four fragments: CNBr I 18-19 kDa, CNBr II 5 kDa, CNBr III 2.1 kDa and CNBr IV 0.7 kDa. Hydrogenbromide/dimethylsulfoxide and 3-bromo-2-(2-nitrophenylsulfenyl)skatol (BNPS-skatol) cleaved lipophilin into four fragments of molecular masses of approximately 14000 (Trp I), 2100 (Trp II), 5000 (Trp III) and 7000 Da (Trp IV). Separation and purification of the peptides for liquid phase sequenator degradation was achieved by high performance liquid chromatography. In addition proteolytic cleavage of the Trp IV fragment with trypsin facilitated the alignment of the peptides. An effective control of the sequenator data came from the partial acid hydrolysis of the Trp IV fragment, which yielded di-, tri- and tetrapeptides. The mixture was N-trifluoroacetylated, the amide (peptide) bonds and carboxyl groups were reduced with B2D6 (hexadeuterodiborane) and the polyaminoalcohols derivatized with chlorotrimethylsilane. These derivatives were separated and identified by capillary gas-liquid chromatography/mass spectrometry. Extensively overlapping sequences support the data obtained by Edman degradation in a liquid phase sequenator of the CNBr peptides II, III and IV, the 72 amino acid residues containing C-terminal sequence of lipophilin of molecular mass (7520 + x) Da, which includes the Trp IV fragment.

Amino Acid Sequence↗
PubMed1981

[Some correlations between ultrasonographic and histopathologic findings in malignant melanoma of the choroid (author's transl)].

The ultrasonographic findings in 39 cases of malignant melanoma of the choroid has been correlated with histopathological results. Tumors with hemorrhages and/or necrosis showed a lower reflectivity than those with a higher amount of connection tissue. B-scan ultrasonography was found to be reliable for the measurement of the extent of the tumor in all three dimensions.

Choroid Neoplasms↗
PubMed1981

[The value of pentetrazol (Deumacard) provocation in EEG for the evaluation of driving ability].

The validity range of P. provocation is not related to clinical differential diagnostics, but to a function-diagnostic approach to the question of epileptic reaction tendency. Independent of the diagnosis, the traffic-medical fitness is constituted by the individual prognosis with respect to prospective traffic-relevant performance reliability. If either bilateral or focal EEG paroxysm can be provoked with the indicated fractionated injection technique, this finding should be judged as risk factor which must be taken into consideration in the interdisciplinary elaboration of the fitness appraisal. The survey of 30 P. provocations shows that the special indication is in particular to be considered as being present in case of a high traffic risk and epileptic or syncopal attacks occurring rarely or having occurred a long time before. On the basis of the gain in function-diagnostic information, P. provocation is found to be an aid in decision making in individual cases which can increase quality and safety degree of the expert's statements.

Automobile Driving↗
PubMed1979

[Topography of orbital lymphomas (author's transl)].

In 15 cases of orbital lymphoma topographic characteristics are demonstrated by contact B-scan ultrasonography as follows: The tumour is only infiltrating some single structures of the orbit as muscles. Tenon's membrane, lacrimal gland and the peripheral orbital space. Such enables the examiner, to take an excision exact in this point, where the tumour is located. The problems in differentiating lymphomas from other pseudotumours and from sarcomas by echography are discussed.

Aged↗
PubMed1978

[Transient myopia with angle closure glaucoma. Case report and biometric findings (author's transl)].

A 36-year-old man suffered from diarrhoea for some weeks and was treated with Salazosulphapyridie and Fluocortulon when he developed a transient myopia combined with an angle closure glaucoma. The refraction of his mild hyperopic eyes (+0,5 dpt) changed to -5,5 dpt and the intraocular pressure increased to 40 mm Hg in the right and 42 mm Hg in the left eye. Accommodation and pupillary reflexes were normal. Ultrasonic examination showed an increased axial diameter and a forward shifting of the lens. The resulting flattening of the anterior chamber induced the angle closure glaucoma. All symptoms disappeared within a week after the administration of Fluocortulon had been discontinued.

Adult↗
PubMed1978

[Topographical diagnosis of orbital lesions with contact B-scan ultrasonography (author's transl)].

With contact B-scan ultrasongraphy it is possible, to determine the topographical relations of space occupieing lesions to the main orbital structures. This enables the examiner to answer three important questions: (1) In which part of the orbit the lesion is located? (2) Is the proptosis produced by a lesion separate from the muscles and the optic nerve or (3) are these structures themselves affected? Our results are compared with those made by A-scan ultrasonography. The existing range of echographical patterns known of orbital tumors is thus widened by the topographical diagnosis elicited by contact B-scan ultrasonography.

Abscess↗
PubMed1977

Oxygen pressure in ischemic muscle tissue of patients with chronic occlusive arterial diseases.

Local tissue oxygen pressure was measured with micro-Pt-electrodes in the resting tibialis anterior muscles of 10 patients with chronic occlusive arterial disease and in 9 healthy subjects. The mean pO2 values in the patient group was 13.3 +/- 5.4 Torr, and 27.2 +/- 4.4 Torr in the control group. The difference is highly statistically significant. Preliminary results of treatment of 10 patients with the rheologically-active drug Ancrod show a statistically significant increase of oxygen pressure in the ischemic muscle tissue. Measurement of muscle tissue pO2 with microelectrodes seems to be an objective and quantitative method to investigate the oxygen supply to ischemic muscles and to judge the effects of therapeutic measures.

Arterial Occlusive Diseases↗
PubMed1976

Muscle-pO2 in trained and untrained non-anesthetized guinea pigs and in men.

pO2-measurements were performed by micro-Pt-electrodes a) in the gastrocnemius muscles of physically trained and untrained non-anesthetized guinea pigs, and b) in the tibialis anterior muscles of physically trained and untrained men, and of patients after a 2-3 weeks bedrest. Physical training raises the mean pO2-values in the resulting muscles of guinea pigs and men from 30-40 Torr to 50-55 Torr whereas physical inactivity (2-3 weeks bedrest) reduces the values to 17-18 Torr.

Animals↗
PubMed1976

[Foveolar aplasia in tyrosinase-positive oculocutaneous albinisim (author's transl)].

The eye of a 47 year old man with tyrosinase-positive oculocutaneous albinism, photophobia, nystagmus and visual acuity 0, 4-0, 5 was histologically examined after orbital exenteration for neoplasia. Histologic serial sections of the centre of the retina showed a continuous 6-8 cell-layer of ganglion cells, without any suggestion of a foveolar pit. The outer layers of the macular retina were altered secondarily by tumor-impression-folds; they were unremarkable at the periphery as were the acid mucopolysaccharides in the receptor region. Electron microscopy of the uvea and the retinal pigment epithelium showed a normal number of pigment granules but a deficiency of melanin, as well as structural anomalies. The absence of the foveolar pit and the decrease of visual acuity in tyrosinase-positive albinism is caused by definite morphologic alteration in the arrangement of ganglion cells in the macular region in the sense of a foveolar aplasia. The etiology is discussed. An identic anomaly has been described in aniridia, similar ones in other congenital ocular diseases.

Albinism↗