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Biomedical subjects

R Feldmann

Publications and source records attributed to R Feldmann.

34 records · Page 2Linked to original sources
PubMed1993

Histamine release from basophils in childhood: age dependency and inhibition by pertussis infection and pertussis toxin.

The influence of childhood pertussis infection and of purified pertussis toxin on histamine release from human basophil leucocytes was investigated. Three different stimuli, the peptide N-formyl-Met-Phe (NFMP), anti-IgE, and the calciumionophore A23187 were used to challenge the cells. When NFMP was the stimulus, histamine release in the control group (age 0.5-17 years) increased in an age-dependent fashion, whereas anti-IgE and A23187 stimulated release did not vary with age. During the convulsive state of pertussis infection there was a significant reduction of histamine release in response to 10 microM NFMP (from 9.5 +/- 1.4 [n = 21] to 6.7 +/- 1.5 [n = 19], P < 0.05) and in response to 800 and 80 U/ml anti-IgE (from 28.5 +/- 5 [n = 19] to 16.3 +/- 5 [n = 13], P < 0.05, and from 6.9 +/- 1.7 [n = 16] to 2 +/- 0.8 [n = 13], P < 0.01), whereas histamine release stimulated by A23187 was unchanged compared to release in control children. In vitro pretreatment of basophils from healthy children and adults with pertussis toxin also inhibited histamine release. When NFMP was the stimulus, release was completely blocked by pertussis toxin with an IC50 of about 11 ng/ml, whereas anti-IgE stimulated release was only inhibited by 20%-30% and release induced by A23187 was reduced to 40%-50% by toxin treatment. In conclusion we have demonstrated a functional impairment of histamine release during the convulsive state of pertussis and that this inhibition is likely to be mediated by pertussis toxin.

Adolescent↗
PubMed1993

[Multiple filiform hyperkeratoses].

We report on a 41-year-old female patient who presented with a 3-year history of multiple filiform hyperkeratoses on the trunk. The family history revealed that her uncle had similar skin lesions. Another patient presented with filiform hyperkeratoses only on the palms of the hands and soles of the feet. This condition, referred to in English as multiple minute digitate hyperkeratoses, is a rare, mostly hereditary, disorder of cornification. As yet there is no official name for this dermatosis in German; we propose "multiple filiforme Hyperkeratosen".

Adult↗
PubMed1992

Orbital and palpebral paraffinoma.

Paraffinoma is a well-recognized complication of paraffin injection. We describe a 44-year-old man who had an ethmoidectomy for chronic sinusitis. A communicating fracture of the ethmoid bone into the orbit occurred intraoperatively. The nasal cavity was subsequently packed with gauze containing a petrolatum-based antibiotic ointment. Bilateral, periocular swelling developed 1 week later. Optical and electron microscopic studies revealed a paraffinoma.

Administration, Intranasal↗
PubMed1992

Fox-Fordyce disease: successful treatment with topical clindamycin in alcoholic propylene glycol solution.

We report a 66-year-old woman with a 3-year history of intensely pruritic follicular papules in the axillar, pubic and inguinal areas. Previous treatment with topical fusidic acid and gentamicin sulfate was ineffective. The clinical and histological examination was consistent with Fox-Fordyce disease. Application of clindamycin in an alcoholic propylene glycol solution led to the clearing of the lesions within 1 month. Nine months later, the treatment was stopped, and no recurrence was observed.

1-Propanol↗
PubMed1991

[The significance of protein C deficiency in dermatology].

The protein C system is a physiological inhibitor of coagulation and is important for the regulation of hemostasis. Protein C deficiencies can be inherited or acquired, and they lead to enhanced thrombophilia. A number of clinical entities that are also of interest to dermatologists have been related to protein C deficiency. Inherited protein C deficiency can become manifest in various ways, e.g. as purpura fulminans neonatalis, as recurrent episodes of thrombosis and as coumarin necrosis. Acquired protein C deficiency can be observed in the course of purpura fulminans, disseminated intravascular coagulation, hepatic failure or in the presence of antiphospholipid antibodies. The clinical features, the possible pathogenesis and the therapy of these manifestations are briefly discussed.

Humans↗
PubMed1991

[Lichen sclerosus et atrophicus].

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.

Adolescent↗
PubMed1990

Papular-purpuric "gloves and socks" syndrome.

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.

Adolescent↗
PubMed1988

FUS: a system to simulate conformational changes in biological macromolecules.

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.

Computer Simulation↗
PubMed1987

[Family groups in Alzheimer's disease: initial experiences and results].

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.

Aged↗
PubMed1985

Comparison of the DNA sequence and secondary structure of the herpes simplex virus L/S junction and the adeno-associated virus terminal repeat.

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.

Base Sequence↗
PubMed1982

Architecture of Limulus polyphemus hemocyanin.

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.

Animals↗
PubMed1981

Decrease of vascular angiotensin sensitivity by L-dopa during human pregnancy.

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.

Angiotensin Amide↗
PubMed1976

Method of preparation and application of small quantities of semi-solid topicals.

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.

Administration, Topical↗
PubMedDate not supplied

[The elderly patient with dementia in the family: principles of counseling relatives].

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.

Adaptation, Psychological↗