Biomedical subjects
Publications and source records attributed to H Vogel.
In 14 patients the x-ray findings of dental, mandibular and maxillary roentgen diagnosis were compared with conventional tomography and tomography by digital radiography. All details important for diagnosis were shown by both techniques. Tomography by digital radiography offered a more convenient approach and pictures easier to be interpreted than pictures by conventional tomography.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The findings of the suprapatellar region in sonography are described of 400 patients. The patterns in sonography of effusion, synovialitis, hemoarthros, soft tissue tumour and soft tissue necrosis, free bodies, and artificial ligaments are demonstrated. The investigation is easy and can be effected with ordinary equipment.
Explore the source record for details and available documents.
This study was performed to determine the toxicity and effectiveness of megestrol acetate used with aminoglutethimide-hydrocortisone in the treatment of patients with metastatic breast cancer. Forty-five patients were treated, 29 of whom were fully eligible. Twelve of the 45 who had diabetes and/or hypertension were also analyzed. All had measurable sites of disease. The median age was 63 years, and the median time from first recurrence to on-study was 19 months. Approximately half the patients already had chemotherapy, and about 90% had hormone therapy for advanced disease. The most common side effects were skin rash, weight gain, hyperglycemia, and renal and neurologic problems. No life-threatening or lethal toxicities were reported. The overall response rate (complete or partial) among the fully eligible patients was 34% (90% confidence intervals from 20% to 51%), with a 5-month median duration of response. Patients with soft tissue, visceral, and osseous disease responded. Seventy-two percent of fully eligible patients have progressed or relapsed. The median time to failure of treatment was 6 months, and the median survival time was 15 months.
The secondary structure of bacterio-opsin (BO), the retinal free protein-component of bacteriorhodopsin (BR), has been determined by Raman spectroscopy. Additional circular dichroism (CD) measurements have revealed only negligible conformational differences between BO in apomembranes and BR in purple membranes. Therefore, the secondary structure of BR was derived from the Raman data of BO. The protein conformation was determined to consist of 72-82% helices, 2-11% beta-strands, and 11-17% beta-turns. Only about half of the helical structures correspond to alpha 1-helices, the other half possess non-alpha 1-helical structures. According to the analysis of the Raman data, the derived secondary structure of BR was obtained with high reliability for all structure classes which can be distinguished by this method within the given uncertainty range. This is a remarkable difference from recently published secondary structural data derived from CD measurements where the helix content was reported to be between 50 and 80%. The inherent experimental and methodological uncertainties of the CD-technique leading to such a range of variation are critically discussed in comparison to the method of Raman spectroscopy. The combined application of Raman and CD spectroscopy, as performed here, is demonstrated to be a substantial improvement in the secondary structure determination of retinal-containing membrane proteins. On the basis of our results, some of the recently proposed structural models of BR with a beta-strand content of more than 11% can be ruled out.
Explore the source record for details and available documents.
The secondary structure of alamethicin in lipid membranes below and above the lipid phase transition temperature Tt is determined by Raman spectroscopy and circular dichroism (CD) measurements. In both cases structural data are obtained by fitting the experimental spectra by a superposition of the spectra of 15 reference proteins of known three-dimensional structure. According to the Raman experiments, in a lipid bilayer above Tt alamethicin is helical from residue 1 to 12, whereas below Tt the helix extends from residue 1 to 16. The remaining C-terminal part is nonhelical up to the end residue 20 both above and below Tt. A considerable lower helix content is derived from CD, namely, 38% and 46% above and below Tt, respectively, in agreement with several reported values for CD in the literature. It is shown that the commonly used set of CD spectra of water-soluble reference proteins is unsuitable to describe the CD spectra of alamethicin correctly. Therefore the secondary structure of alamethicin as derived from CD measurements is at the present state of analysis unreliable. In contrast to the case of alamethicin, the CD spectra of melittin in lipid membranes are correctly described by the reference protein spectra. The helix content of melittin is determined thereby to be 72% in lipid membranes above Tt and 75% below Tt. The data are in accord with a structure where the hydrophobic part of melittin adopts a bent helix as determined recently by Raman spectroscopy [Vogel, H., & Jähnig, F. (1986) Biophys. J. 50, 573]. The orientational order parameters of the helical parts of alamethicin and of melittin in a lipid membrane are deduced from the difference between a corresponding CD spectrum of a polypeptide in planar multibilayers and that in lipid vesicles. The presented method for determining helix order parameters is new and may be generally applicable to other membrane proteins. The orientation of the helical part of both polypeptides depends on the physical state of the lipid bilayer at maximal membrane hydration and in the ordered lipid state furthermore on the degree of membrane hydration. Under conditions where alamethicin and melittin are incorporated in an aggregated form in a fluid lipid membrane at maximal water content the helical segments are oriented preferentially parallel to the membrane normal. Cooling such lipid membranes to a temperature below Tt changes the orientation of the helical part of alamethicin as well as melittin toward the membrane plane.(ABSTRACT TRUNCATED AT 400 WORDS)
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In the infrapatellar region of the knee it is possible to demonstrate by sonography bursitis, tendinopathy, Hoffa's disease, and characteristic postoperative alterations. Bursitis is characterised by oval, echo-poor, badly limited structures in typical places. Typical of the tendinopathy of the patellar ligament is an enlargement of more than 8 mm.; calcifications can be seen in the region between 5 and 8 mm. In Hoffa's disease, the fatty tissue in the knee joint shows localised changes of the structure, scars are echo-poor, homogeneous structures within the solitary Hoffa lipoma. Postoperatively implanted metal can be observed and its position can be judged. The raised tibial cortical layer after Bandi's operation can be visualised in the sonogram.