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Biomedical subjects

P Schiller

Publications and source records attributed to P Schiller.

At least 19 recordsLinked to original sources
PubMed2002

[Henoch-Schoenlein syndrome in an 80-year-old patient].

HISTORY AND CLINICAL FINDINGS: An 80-year old female patient, hospitalised with pneumonia and myocardial infarction, suddenly developed fever, dyspnoea, malaise, arthralgia and crampy abdominal pain. On the following day, she developed a petechial rash and on the 6 (th) day, macroscopic haematuria. On physical examination, the patient presented with a temperature of 40 degrees C, tachypnoea, tachycardia, and on auscultation coarse crepitations at the left lower base. The abdomen was tender upon deep palpation but bowel sounds were normal. Initially the petechial rash was located at the trunk, later progressing towards the extremities. INVESTIGATIONS: Chest X-ray and laboratory tests were consistent with left lower lobe pneumonia. The clinical picture was not consistent with any haematological causes, coagulopathy or any medication the patient was taking. Rheumatological blood tests (involving ANA, ANCA, rheumatoid factors) were basically negative. A skin biopsy revealed microvessel necrosis and IgA deposits, verifying Henoch-Schoenlein Purpura. An immune electrophoresis revealed a selective IgG-deficiency, which may explain the cause for the patient's recurrent pneumonias. COURSE: The patient recovered well under antibiotic treatment and skin lesions healed without sequelae. CONCLUSION: We present an unusual case of Henoch Schoenlein purpura associated with strictly petechial rash in an 80 year old female.

Aged↗
PubMed2002

Experiments with small animals in BIOLAB and EMCS on the International Space Station.

Two ESA facilities will be available for animal research and other biological experiments on the International Space Station: the European Modular Cultivation System (EMCS) in the US Lab "Destiny" and BIOLAB in the European "Columbus" Laboratory. Both facilities use standard Experiment Containers, mounted on two centrifuge rotors allowing either research in microgravity or acceleration studies with variable g-levels from 0.001 to 2.0 x g. Standard interface plates provide each container with power and data lines, gas supply (controlled CO2, O2 concentration and relative humidity), and--for EMCS only--connectors to fresh and waste water reservoirs. The experiment hardware inside the containers will be developed by the user, but ESA conducted a feasibility study for several kinds of Experiment Support Equipment with potential use for research on small animals: design concepts for experiments with insects, with aquatic organisms like rotifers and nematodes, and with small aquatic animals (sea urchin larvae, tadpoles, fish youngsters) are described in detail in this presentation. Also ESA's initial steps to support experiments with rodents on the Space Station are presented.

Animals↗
PubMed2001

Short-term inverse-agonist treatment induces reciprocal changes in delta-opioid agonist and inverse-agonist binding capacity.

This study assessed the effects of short-term treatment (30-min) with inverse agonists on receptor protein levels and on the ability of agonists, inverse agonists, and neutral antagonists to bind to the human delta-opioid receptor (h delta OR). Incubation of human embryonic kidney 293s cells stably expressing h delta OR with the inverse agonist ICI174864 (1 microM) induced reciprocal changes in agonist and inverse-agonist binding. The total number of binding sites recognized by the agonists [(3)H]bremazocine and [(3)H][D-Pen(2),D-Pen(5)]-enkephalin was reduced by 33 and 57%, respectively, whereas binding capacity for the radiolabeled inverse-agonist [(3)H]Tyr-TicY[CH(2)NH]Cha-Phe-OH increased by 44%. In contrast, total receptor protein and sites labeled by neutral antagonists [(3)H]naltrindole and [(3)H]Tyr-D-Tic-Phe-Phe-OH remained unchanged. Pertussis toxin (PTX) and 5-guanylylimidodiphosphate (GppNHp) mimicked the outcome of ICI174864 pretreatment in promoting the loss of agonist binding sites. The lack of an additive effect on [(3)H]bremazocine binding when these three agents were combined indicates that inverse agonists may, in part, share the mechanism by which GppNHp and PTX reduce agonist binding capacity. Spontaneous recovery of maximal agonist binding capacity after inverse-agonist treatment was slow, suggesting a decrease in the isomerization rate between agonist- and inverse agonist-preferring conformations. Overall, the data presented are consistent with the idea that h delta ORs exist in multiple states capable of discriminating among ligands of different levels of efficacy and show that, after short-term treatment with an inverse agonist, the receptor ability to adopt conformations preferentially induced by agonist ligands is reduced.

Analgesics↗
PubMed2000

Indirect interaction of colloidal particles adsorbed on smectic films.

Colloidal particles like peptides and proteins adsorbed on a stack of lipid bilayers cause elastic deformations which disturb the smectic order. Two adsorbed particles attract each other due to the superposition of their deformation fields. The effective pair potential attributed to this substrate-mediated force decays exponentially with the particle distance. The range of this potential coincides with the decay length of elastic deformations, and is found to be proportional to the square root of the stack thickness. If the stack is sufficiently thick, the substrate-mediated interaction is estimated to be strong enough to overcome the entropic barrier and enforce aggregation or even crystallization of the adsorbate.

Adsorption↗
PubMed1999

Double-lined frontoparietal scleroderma en coup de sabre.

We describe a rare case of double-lined frontoparietal scleroderma en coup de sabre. The relationship to the distribution following the lines of Blaschko is discussed. In addition, we present a genetic hypothesis which is based on a mosaic state induced by postzygotic mosaicism. A patient with scleroderma en coup de sabre has a mosaic state for genes which predispose to susceptibility for linear scleroderma.

Adult↗
PubMed1998

Placenta growth factor stimulates MAP kinase and mitogenicity but not phospholipase C-gamma and migration of endothelial cells expressing Flt 1.

Vascular endothelial growth factor (VEGF) and placenta growth factor (PIGF) are structurally related growth factors for endothelial cells. VEGF binds to the related receptor tyrosine kinases Flt 1 and KDR/Flk 1 with high affinity, whereas PlGF binds only to Flt 1. Ligand-stimulated KDR is known to transduce signals for cellular activity such as proliferation and migration, whereas weak or no responses have been recorded for Flt 1. We examined VEGF and PlGF for their capacity to stimulate signal transduction in porcine aortic endothelial cells expressing Flt 1 or KDR. VEGF had essentially no effect on Flt 1 expressing cells, but induced DNA synthesis and migration of KDR expressing cells. PIGF on the other hand induced DNA synthesis but not migration of the Flt 1 cells. In agreement, MAP kinase, examined as a marker for DNA synthesis, was activated both by VEGF-stimulation of the KDR cells and by PlGF-stimulation of the Flt 1 cells. In contrast, phospholipase C-gamma (PLC-gamma), was tyrosine phosphorylated only in VEGF stimulated KDR cells, and not in the PlGF-stimulated Flt 1 cells, which is in agreement with a role for PLC-gamma in cellular migration. We furthermore examined induction of protein levels of plasminogen activator (PA), which was evident in the PlGF-stimulated Flt 1 cells, but not in the VEGF-stimulated KDR cells. These data show that Flt 1 is able to mediate an array of biological signals when appropriately stimulated and that the pattern of responses of PlGF-stimulation of Flt 1 is distinct from the pattern of responses to VEGF-stimulation of KDR.

Animals↗
PubMed1996

Preservation of viable biological samples for experiments in space laboratories.

Standard viable preservation methods for biological samples using low temperatures have been investigated concerning their storage capabilities under higher temperature levels than usual. For a representative set of organism classes (plants, mammalian cells, arthropods and aquatic invertebrates), the minimum appropriate storage conditions have been identified by screening storage temperatures at -196 degrees, -80 degrees, -20 degrees, +4 degrees, +20 degrees/25 degrees C for periods from 2 days to 4 weeks. For storage below 0 degree C, as a typical cryopreservative, dimethylsulfoxide (DMSO) was used. For some samples, the addition of trehalose (as cryopreservative) and the use of a nitrogen atmosphere were investigated. After storage, the material was tested for vitality. The findings demonstrated that acceptable preservation can be achieved under higher storage temperatures than are typically applied. Small, dense cultured plant cells survive for 21 d when moderately cooled (+4 degrees to -20 degrees C); addition of trehalose enhances viability at -20 degrees C. For mammalian cells, the results show that human lymphocytes can be preserved for 3 d at 25 degrees C, 7 d at 4 degrees C and 28 d at -80 degrees C. Friend leukaemia virus transformed cells can be stored for 3 d at 25 degrees C, 14 d at 4 degrees C and 28 d at -80 degrees C. Hybridoma cells can be kept 7 d at 4 degrees C and 28 d at -20 degrees C or -80 degrees C. Model arthropod systems are well preserved for 2 weeks if maintained at lower temperatures that vary depending on the species and/or stage of development; e.g., 12 degrees C for Drosophila imagoes and 4-6 degrees C for Artemia nauplii. For aquatic invertebrates such as sea urchins, embryonic and larval stages can be preserved for several weeks at +6 degrees C, whereas sperm and eggs can best be stored at + 4 degrees C for up to 5 d at maximum. These results enhance the range of feasible space experiments with biological systems. Moreover, for typical terrestrial preservation methods, considerable modification potential is identified.

Animals↗
PubMed1995

Level of functioning, severity of illness, and smoking status among chronic psychiatric patients.

It was hypothesized that chronic psychiatric patients who had quit smoking would be more functional and have lower Brief Psychiatric Rating Scale (BPRS) scores than those who continued to smoke. We interviewed 300 chronic psychiatric patients followed in the community. Fourteen percent were former smokers and nearly 11% had never smoked. Fifty-six percent of the sample were current smokers who had no intention of quitting, 13% were considering quitting, and 6% were seriously preparing to quit or had actually quit for a short period. When compared with current smokers, former smokers were more likely to live independently (p < .026) and less likely to have a drug or alcohol problem (p < .013). A random sample of current smokers were compared with former smokers on the BPRS. Former smokers had lower total BPRS scores (p < .03), and lower withdrawal/retardation subscale scores (p < .0058) than current smokers. We concluded that better functioning patients who smoked would be more likely to quit.

Adult↗
PubMed1995

Isolated lichen planus of the lip.

Oral lichen planus (LP) is a relatively common disorder of unknown aetiology. Oral LP occurs most often on the buccal mucosa, but the gingivae, tongue, floor of the mouth, retromalar pads and lips may also be affected. Usually, patients have multiple sites of involvement. We report a 44-year-old patient with a 3-year history of isolated swelling of the lower lip, erosions and crusting. Histology of a biopsy from the lip revealed features of LP. Oral treatment with acitretin and low-dose steroid led to complete resolution of the lesions within 10 weeks. This is the first well-documented case of isolated LP of the lip. Diagnostic difficulties and differential diagnosis are reviewed.

Acitretin↗
PubMed1995

Characterization of the spinal antinociceptive activity of constrained peptidomimetic opioids.

We examined the in vitro and in vivo bioactivities of several families of peptidomimetic opioids including: constrained linear enkephalin (n = 12 analogs), dermorphin (n = 9 analogs) and morphiceptin (n = 17 analogs). The biological activities were assessed in vitro by examining the inhibitory effects of these agents on the electrically evoked contractions of the guinea pig ileum (GPI) and the mouse vas deferens (MVD) preparations. The in vivo bioactivities were determined from the antinociceptive activity of these agents on the 52.5 degrees C hot-plate test after spinal administration of rats with chronically placed spinal catheters. Examination of the effect of cyclization, incorporation of retro-inverso bonds and substitutions of D- or constrained amino acids reveals systematic changes in the activity of these agents. There was a significant correlation between the potency of these agents in the hot-plate bioassay and their activity in the GPI and, to a lesser extent, in the MVD tests. Examination of the ability of naltrindole (a delta selective antagonist) to reverse the drug action and the respective potency on the GPI and MVD, showed that a correlation exists with actions on the MVD, but not on the GPI, consistent with the likelihood that agents with high MVD/GPI ratios in vitro act at the mu sites, whereas those with low MVD/GPI ratios act at the delta receptor in the spinal cord. The close correlations between activity in the GPI and spinal cord suggest that the structural requirements for potency in the smooth muscle and in the spinal cord are essentially the same as those mu receptors that mediate nociceptive transmission.

Amino Acid Sequence↗
PubMed1993

Common histopathological changes in aged human orbital arteries.

The physiology of the orbital arteries supplying the eye is currently under intensive investigation. However, while the anatomical distribution of these vessels in humans is well known, their normal histology and age-related or other pathologic alterations have hardly been studied. We obtained at autopsy 10 orbits from persons aged > or = 74 years, and two orbits from a person aged 47 years. Specimens were taken from 20 locations along the orbital arteries, from the internal carotid to the globe, and studied by light microscopy. We observed the following arteriosclerotic changes, in order of decreasing frequency: intimal hyperplasia, medial atrophy, atherosclerotic fibrous plaques, and calcifications of the internal elastic lamina. As a rule, the intensity of the changes decreased from proximal to distal. This study shows that aged human orbital arteries are readily subject to degenerative changes that may play an important role in ophthalmic vascular disease.

Aged↗
PubMed1992

Pilot CELSS based on a maltose-excreting Chlorella: concept and overview on the technological developments.

A typical ecosystem is composed of three compartments: photosynthetic producer (anabolizing processes), consumer and decomposer (catabolizing processes). It is still far too much complex, however, to form the basis on which establishing an engineered artificial ecosystem, dedicated to support life (of the consumer) in space. A simpler, two compartments, pilot model to start with has been selected. It is based on a symbiotic Chlorella (strain 241.80), which can be tuned, at low pH, to produce maltose. This feature prevents the accumulation of useless biomass, not readily edible by the consumer. Being excreted, maltose is easily recoverable, and constitutes a direct source of carbon suitable for many consumers. Since they will totally catabolize it back to CO2, the necessity for a decomposer compartment is avoided. The present status of the technological concept designed to support life of small consumers (animals, microorganisms) will be presented, taking into account the space compatibility of the technologies developed.

Biomass↗