Biomedical subjects
Publications and source records attributed to R Feldmann.
A review of lichen sclerosus et atrophicus is presented in this article. Clinical manifestations, possible complications and histology are described. Particular emphasis is given to the aetiological hypotheses, which include genetic, autoimmune, hormonal and infectious mechanisms. Finally, the various treatments are discussed.
We report five cases of an acute, self-limiting dermatosis that has not been previously described. It consists of a pruritic edema and erythema of the hands and feet in a gloves-and-socks distribution and is associated with oral lesions and fever. The clinical course is characterized by the rapid development of petechial purpura and clearing of lesions within 1 to 2 weeks. The disease appears to affect only young and otherwise healthy persons and occurs mostly during the spring. The etiology is unknown but might be of infectious origin.
In order to study the dynamics of protein and nucleic acid conformations, a molecular folding-unfolding system (FUS written in Lisp) has been developed. Secondary structure features of protein and nucleic acids are graphically represented by cubes in a modified 'Blocks World' paradigm. Modeling of protein and nucleic acid unfolding (denaturation) and folding of their three-dimensional structure is possible by the use of high level 'block' operators which allow displacement of these structural features in space. Due to the flexible nature of this program, FUS is a useful tool for the rapid evaluation of user-defined rules governing conformational changes. The use of FUS to unfold three common proteins (prealbumin, flavodoxin and triose phosphate isomerase) and a tRNA is presented.
A regular family support group was established within an outpatient clinic for demented elderly patients. At the outset of the group, the relatives knew little about the disease and about the available resources of help, but some were highly experienced in the management of dementia. The group provided information, exchange of experience, practical problem-solving, support in emotional difficulties, and clarification of interpersonal conflicts in the family. The effect of the group showed in decreased feelings of burden and tension in most participants. The present observations suggest that family support groups should be long-termed and that the experts' primary task is to activate and amplify the self-help potential of the caregivers.
The defective parvovirus Adeno-associated virus (AAV) is absolutely dependent upon coinfection with either Adenovirus or Herpes Simplex Virus (HSV) for its multiplication. We have compared the terminal repeats of HSV-1F strain DNA with the terminal 200 nucleotides of AAV DNA. Our findings demonstrate similarities between portions of the HSV inverted repeats found at the L/S junction and the termini of AAV. By computer analysis we have determined potential secondary folding patterns for both genomes. The following points can be made about the a, b, and c repeats in HSV: (1) Regions b and c are complementary over a significant portion of their length. (2) The ends of a can fold back on themselves to form large secondary structures. Moreover, when the b and c homology is used to align the ends of a, the b/a and c/a junctions are within 1 base of each other. (3) The short direct repeats within a are essentially a large loop with little secondary structure. The potential implications of this structure are discussed and a model for HSV DNA replication is presented.
The architecture of the 48-meric hemocyanin of the horseshoe crab Limulus polyphemus has been determined from electron micrographs of whole (48-mer) molecules and half- (24-mer) molecules. The assembly of hexamers of kidney-shaped subunits can produce two dodecameric enantiomorphs, designated as right and left. The assembly of 24-mers can again result in two enantiomorphs. By taking into account the rocking effect described by Van Heel and Frank [Van Heel, M., & Frank, J. (1981) Ultramicroscopy 6, 187-194], we deduced that the 24-meric half-molecule is made up of two copies of the left dodecameric enantiomorph. In addition, the two constituent dodecamers of the half-molecule are shifted with respect to a symmetric head-to-tail arrangement, which makes it possible to distinguish two different faces of the 24-mer, termed flip and flop. A model of the whole molecule was built from two copies of the 24-meric half-molecule. This model presents the four distinct views observed in the electron microscope (pentagon, ring, cross, and bowtie). In addition, the model shows the pentagonal view to exist in two varieties: symmetric and asymmetric. An analysis of electron micrographs presenting the pentagonal view by image processing using the statistical technique of correspondence analysis confirmed the existence of two types of pentagonal view, representing projections of a molecule built from two copies of the left 24-meric enantiomorph. In addition, the best fit between the averaged molecule images and the possible models was observed with a flop-flop inter 24-mer contact. The final model is shown in a series of stereo views produced by computer graphical techniques.
In 27 pregnant subjects (21 treated women and six control subjects), the effect of L-dopa (500 to 1,000 mg orally) on vascular sensitivity to angiotensin II amide (Hypertensin, Ciba) was examined in 16 of these women, 1,000 mg of L-dopa resulted in a significant decrease in vascular responsiveness to angiotensin, i.e., an increase in angiotensin pressor dose from 16.9 +/- 5.0 to 19.6 +/- 4.5 ng . kg-1 . min-1 (mean +/- SD). In women with an initially low angiotensin pressor dose, the changes were more pronounced. In six control subjects, in whom two angiotensin infusion tests were performed consecutively without additional administration of L-dopa, an increase in vasopressor response to angiotensin was demonstrated. Possible causes for the L-dopa-induced decrease in angiotensin sensitivity are discussed: an inhibition of sympathetic nervous activity, a directly lowered total peripheral resistance, a natriuresis and diuresis, and an altered dopaminergic activity in the hypothalamus. It is hypothesized that long-term treatment with L-dopa or bromocriptine might not only decrease angiotensin sensitivity but also elevated pregnancy-induced hypertension.
Quantifying with accuracy small amounts of semi-solid viscus materials is critical in some situations. A sample dish and loading device for a micropipette is described which permits efficient and accurate loading and dispensing of microliter quantities. This is especially valuable for dealing with small quantities of radiolabelled viscus materials.
For the majority of demented elderly persons the family is the most important resource of support. Living with a demented family member lays a heavy strain on the care-givers. Appropriate counselling may reduce the care-givers' burden and enable them to be more effective. In the present report, some general guidelines of family support are proposed, summarising two years of experience in a special outpatient clinic for the demented elderly.