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1.
Photoacoustics ; 31: 100513, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37275325

ABSTRACT

Atopic dermatitis (AD) is the most common chronic inflammatory skin disease worldwide. Its severity is assessed using scores that rely on visual observation of the affected body surface area, the morphology of the lesions and subjective symptoms, like pruritus or insomnia. Ideally, such scores should be complemented by objective and accurate measurements of disease severity to standardize disease scoring in routine care and clinical trials. Recently, it was shown that raster-scanning optoacoustic mesoscopy (RSOM) can provide detailed three-dimensional images of skin inflammation processes that capture the most relevant features of their pathology. Moreover, precise RSOM biomarkers of inflammation have been identified for psoriasis. However, the objectivity and validity of such biomarkers in repeated measurements have not yet been assessed for AD. Here, we report the results of a study on the repeatability of RSOM inflammation biomarkers in AD to estimate their precision. Optoacoustic imaging analysis revealed morphological inflammation biomarkers with precision well beyond standard clinical severity metrics. Our findings suggest that optoacoustic mesoscopy may be a good choice for quantitative evaluations of AD that are inaccessible by other methods. This could potentially enable the optimization of disease scoring and drug development.

2.
Pneumologie ; 75(5): 369-376, 2021 May.
Article in German | MEDLINE | ID: mdl-33472251

ABSTRACT

Various vasodilator medications are used in the treatment of pulmonary arterial hypertension (PAH), such as endothelin receptor antagonists (ERA) or phosphodiesterase-5-(PDE-5-)inhibitors. In a human ex vivo model, we investigated whether the combination of two substance classes could achieve a higher effect or - without loss of vasodilatation - a lower dosage of the individual substances might be sufficient. We established an ex vivo organ bath model to evaluate the dose-dependent effects of ERA and PDE-5-inhibitors on pulmonary vessels harvested from patients who underwent surgery (lung resection/transplantation). We compared the combined use of both substance classes with administration of one class of drugs alone. Due to the limitations of the experimental design, it is not possible to extrapolate our results to the conditions in vivo. Nevertheless, organ bath proved to be helpful in evaluating the dose-dependent effects of ERA and PDE-5 inhibitors, which is not practical in everyday clinical practice. In this setting, the effectiveness of the combination therapy and the potential for dose reduction depended on the concentrations used and on the influence of previous illnesses on blood vessel function. This article describes the most important results of our experimental investigations and suggestions for future projects.


Subject(s)
Hypertension, Pulmonary , Pharmaceutical Preparations , Pulmonary Arterial Hypertension , Antihypertensive Agents , Drug Therapy, Combination , Humans , Hypertension, Pulmonary/drug therapy , Phosphodiesterase 5 Inhibitors/therapeutic use
3.
Pulm Pharmacol Ther ; 66: 101985, 2021 02.
Article in English | MEDLINE | ID: mdl-33359621

ABSTRACT

PURPOSE: Medical combination therapy of pulmonary arterial hypertension (PAH) may alleviate the drawbacks of monotherapy by avoiding drug tolerance and by increasing effectiveness, as shown by the combination of ambrisentan and tadalafil (AMBITION trial). The present ex-vivo study evaluated the combination of the endothelin receptor antagonists (ERA) macitentan and bosentan with the phosphodiesterase-5 (PDE-5) inhibitor vardenafil in pulmonary arteries from patients suffering from terminal lung disease as a model of PAH. METHODS: Segments of the pulmonary vessels were excised from resected lungs of patients requiring lung transplantation (LTX). Contraction of pulmonary arteries (PA) was elicited by consecutive dose-response curves of endothelin-1 (ET-1) followed by norepinephrine (NE) to allow inhibition by different pathways. Forces were measured isometrically in an organ bath in the presence and absence of ERA and PDE-5 inhibitors and their combination. RESULTS: PA of 38 patients were examined between October 2016 and November 2019. Bosentan (1E-7 M) and macitentan (1E-8 M, 3E-8 M, 1E-7 M) inhibited ET-1 induced contractions, whereas vardenafil (1E-6 M, 3E-6 M, 1E-5 M) inhibited only the NE induced part of the contractions. Vardenafil enhanced bosentan-induced inhibition of vasoconstriction in a dose-dependent fashion. Combination effects exceeded single bosentan at 3E-6 M and 1E-5 M vardenafil, and they exceeded single vardenafil at the lower vardenafil concentrations. Macitentan showed a more pronounced inhibition than bosentan regardless of the lower concentrations. Accordingly, combination effects with vardenafil resembled those of macitentan alone. CONCLUSIONS: Macitentan and bosentan were potent antagonists of vasoconstriction in PA of LTX patients. The benefit of drug combinations was demonstrated at selected concentrations only owing to a narrow therapeutic range of vardenafil in this ex-vivo model. These results suggest the utility of drug combinations other than the established pair of ambrisentan and tadalafil in PAH treatment but also make a case for a further assessment of vasodilator properties of drugs complementing ERA.


Subject(s)
Hypertension, Pulmonary , Pulmonary Arterial Hypertension , Cyclic Nucleotide Phosphodiesterases, Type 5 , Endothelin Receptor Antagonists/pharmacology , Humans , Hypertension, Pulmonary/drug therapy , Phosphodiesterase 5 Inhibitors/pharmacology , Pulmonary Artery
4.
Phys Rev Lett ; 120(10): 105501, 2018 Mar 09.
Article in English | MEDLINE | ID: mdl-29570335

ABSTRACT

Long wavelength vibrational modes in the ferromagnetic semiconductor Ga_{0.91}Mn_{0.09}As are investigated using time resolved x-ray diffraction. At room temperature, we measure oscillations in the x-ray diffraction intensity corresponding to coherent vibrational modes with well-defined wavelengths. When the correlation of magnetic impurities sets in, we observe the transition of the lattice into a disordered state that does not support coherent modes at large wavelengths. Our measurements point toward a magnetically induced broadening of long wavelength vibrational modes in momentum space and their quasilocalization in the real space. More specifically, long wavelength vibrational modes cannot be assigned to a single wavelength but rather should be represented as a superposition of plane waves with different wavelengths. Our findings have strong implications for the phonon-related processes, especially carrier-phonon and phonon-phonon scattering, which govern the electrical conductivity and thermal management of semiconductor-based devices.

5.
Phys Rev Lett ; 118(5): 053003, 2017 Feb 03.
Article in English | MEDLINE | ID: mdl-28211728

ABSTRACT

Multiphoton ionization of potassium atoms with a sequence of two counter-rotating circularly polarized femtosecond laser pulses produces vortex-shaped photoelectron momentum distributions in the polarization plane describing Archimedean spirals. The pulse sequences are produced by polarization shaping and the three-dimensional photoelectron distributions are tomographically reconstructed from velocity map imaging measurements. We show that perturbative ionization leads to electron vortices with c_{6} rotational symmetry. A change from c_{6} to c_{4} rotational symmetry of the vortices is demonstrated for nonperturbative interaction.

6.
Article in German | MEDLINE | ID: mdl-22373848

ABSTRACT

Medicinal products for specific immunotherapy as causal treatment of allergies exist in Germany as authorized medicinal products manufactured batchwise in advance and as named patient products (NPPs) which are exempted from the authorization procedure. With the therapy allergens ordinance ("Therapieallergene-Verordnung (TAV)") which has been in effect since 14 November 2008, this exemption was restricted to therapy allergens indicated for the treatment of rare allergies. NPPs containing at least one of the therapy allergens listed in the annex of the TAV had to be notified to the Paul-Ehrlich-Institut (PEI) by 14 May 2009 to retain their marketability. It had to be stated whether applications for marketing authorization will be submitted for the respective NPPs or if they will be sold off by 14 November 2011. The bulks which are used for manufacturing of the NPPs have been subject to official batch release by PEI since October 2009. Nearly 7,000 NPPs of 10 pharmaceutical entrepreneurs were notified. Marketing authorization applications were submitted for 123 NPPs. This illustrates that, although there are authorized therapy allergens available for all allergens listed in the annex of the TAV, a large number of NPPs with unknown quality, safety, and efficacy have been marketed.


Subject(s)
Allergens/immunology , Desensitization, Immunologic , Drug Approval/legislation & jurisprudence , Hypersensitivity/therapy , Marketing of Health Services/legislation & jurisprudence , National Health Programs/legislation & jurisprudence , Allergens/administration & dosage , Drug Industry/legislation & jurisprudence , Germany , Health Services Accessibility/legislation & jurisprudence , Humans , Hypersensitivity/immunology , Quality Assurance, Health Care/legislation & jurisprudence
7.
Biochim Biophys Acta ; 1800(11): 1192-202, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20600625

ABSTRACT

BACKGROUND: Prerequisite for the design of tight binding protein inhibitors and prediction of their properties is an in-depth understanding of the structural and thermodynamic details of the binding process. A series of closely related phosphonamidates was studied to elucidate the forces underlying their binding affinity to thermolysin. The investigated inhibitors are identical except for the parts penetrating into the hydrophobic S1'-pocket. METHODS: A correlation of structural, kinetic and thermodynamic data was carried out by X-ray crystallography, kinetic inhibition assay and isothermal titration calorimetry. RESULTS AND CONCLUSIONS: Binding affinity increases with larger ligand hydrophobic P1'-moieties accommodating the S1'-pocket. Surprisingly, larger P1'-side chain modifications are accompanied by an increase in the enthalpic contribution to binding. In agreement with other studies, it is suggested that the release of largely disordered waters from an imperfectly hydrated pocket results in an enthalpically favourable integration of these water molecules into bulk water upon inhibitor binding. This enthalpically favourable process contributes more strongly to the binding energetics than the entropy increase resulting from the release of water molecules from the S1'-pocket or the formation of apolar interactions between protein and inhibitor. GENERAL SIGNIFICANCE: Displacement of highly disordered water molecules from a rather imperfectly hydrated and hydrophobic specificity pocket can reveal an enthalpic signature of inhibitor binding.


Subject(s)
Organophosphorus Compounds/chemistry , Organophosphorus Compounds/metabolism , Phosphoamino Acids/chemistry , Thermolysin/metabolism , Water/chemistry , Binding Sites , Crystallography, X-Ray , Entropy , Hydrophobic and Hydrophilic Interactions , Models, Molecular , Protein Binding , Protein Structure, Tertiary , Thermodynamics , Water/metabolism
8.
Ann R Coll Surg Engl ; 91(7): 583-90, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19558787

ABSTRACT

INTRODUCTION: The objective of this study was to determine the safety and acceptability of the implementation of a day-case laparoscopic cholecystectomy (LC) service in a large UK teaching hospital, and analyse factors influencing contact with primary care providers. Wide-spread introduction of day-case LC in the UK is a major target of healthcare providers. However, few centres have reported their experience. In the US, out-patient surgery for LC has been reported, though many groups have utilised 24-h observation units to facilitate discharge. Concerns remain amongst surgeons regarding the feasibility and acceptability of the introduction of day-case LC in the UK. PATIENTS AND METHODS: Comprehensive care and operative data were prospectively collected on the first 106 consecutive day-case procedures in our hospital. Postoperative recovery was monitored by telephone questionnaire on days 2, 5 and 14, including complications, satisfaction and general practitioner consultation. RESULTS: A total of 106 patients were admitted for day-case LC, of whom 84% were discharged on the day of surgery. Patient satisfaction rate was 94% in both the successful day-case and the admitted patients. Mean operation time was 62 min, with an average total stay on the day-care unit of 426 min. Training-grade surgeons performed 31% of operations. Both the readmission rate after surgery and rate of conversion to open surgery were 2%. Advice from primary healthcare providers was sought by 33% of patients within the first 14 postoperative days. CONCLUSIONS: Introduction of day-case LC in the UK is feasible and acceptable to patients. The potential burden to primary care providers needs further study.


Subject(s)
Ambulatory Surgical Procedures/statistics & numerical data , Cholecystectomy, Laparoscopic/methods , Patient Discharge , Patient Satisfaction , Adult , Aged , Ambulatory Surgical Procedures/adverse effects , Feasibility Studies , Female , Hospitals, Teaching , Humans , Male , Middle Aged , Outcome and Process Assessment, Health Care , Outpatient Clinics, Hospital , Pain, Postoperative , Patient Readmission , Postoperative Nausea and Vomiting/etiology , Prospective Studies , Surveys and Questionnaires , United Kingdom , Young Adult
9.
Opt Express ; 15(26): 17855-62, 2007 Dec 24.
Article in English | MEDLINE | ID: mdl-19551080

ABSTRACT

Control of two basic ionization processes in dielectrics i.e. photo ionization and electron-electron impact ionization on intrinsic time and intensity scales is investigated experimentally and theoretically. Temporally asymmetric femtosecond pulses of identical fluence, spectrum and pulse duration result in different final free electron densities. We found that an asymmetric pulse and its time reversed counterpart address two ionization processes in a different fashion. This results in the observation of different thresholds for surface material modification in sapphire and fused silica. We conclude that control of ionization processes with tailored femtosecond pulses is suitable for robust manipulation of breakdown and thus control of the initial steps of laser processing of high band gap materials.


Subject(s)
Aluminum Oxide/chemistry , Aluminum Oxide/radiation effects , Lasers , Manufactured Materials , Semiconductors , Silicon Dioxide/chemistry , Silicon Dioxide/radiation effects , Ions , Materials Testing
10.
Bone Marrow Transplant ; 37(3): 263-9, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16327813

ABSTRACT

The major problems with busulfan/cyclophosphamide (Bu/Cy)-containing conditioning regimens are acute toxicities and graft failure. To decrease acute toxicities, we have prospectively evaluated a reduced intensity conditioning (RIC) regimen using targeted dosing of i.v. busulfan, fludarabine, and rabbit ATG (Bu/Flu/rATG) in children with diagnoses that historically would have been conditioned with Bu/Cy regimens. Nineteen pediatric patients were enrolled in the study. The donors included HLA-matched and one antigen-mismatched unrelated volunteers (n = 11), unrelated cord blood (n = 1), and related donors (n = 7). Four patients developed graft failure, which occurred between 1 and 8.5 months post transplant. All four of them underwent a second transplantation and 3/4 are alive without evidence of disease. The mean follow-up of living patients is 29.5 +/- s.d. 11 months. Despite excellent 2-year post-transplant overall survival (89 +/- s.d.7%) and event-free survival (74 +/- s.d.10%), the study was closed prematurely due to high graft failure rate (21%). Receiving a transplant from a mismatched unrelated donor was identified as a risk factor for graft failure. The Bu/Flu/rATG RIC regimen was very well tolerated, resulted in excellent overall survival, and provided sustained engraftment in patients undergoing transplant from matched sibling and unrelated donors. However, it did not provide sustained engraftment in the majority of children with nonmalignancies undergoing mismatched unrelated donor transplants.


Subject(s)
Antilymphocyte Serum/administration & dosage , Busulfan/administration & dosage , Hematologic Diseases/therapy , Hematopoietic Stem Cell Transplantation , Immunosuppressive Agents/administration & dosage , Living Donors , Myeloablative Agonists/administration & dosage , Transplantation Conditioning , Vidarabine/analogs & derivatives , Adolescent , Adult , Animals , Child , Child, Preschool , Disease-Free Survival , Graft Rejection/mortality , Graft Survival/drug effects , Graft vs Host Disease/mortality , Hematologic Diseases/complications , Hematologic Diseases/mortality , Hematopoietic Stem Cell Transplantation/methods , Humans , Infant , Infusions, Intravenous , Male , Prospective Studies , Rabbits , Transplantation Conditioning/methods , Transplantation, Autologous , Vidarabine/administration & dosage
11.
Br J Anaesth ; 86(2): 189-95, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11573658

ABSTRACT

Doubt remains about the conditions under which learning persists despite anaesthesia. This study investigated the relative importance of dose of anaesthetic and stimulation for learning during propofol infusion before surgery. Thirty-six patients were randomly assigned to three groups. Group 1 received two word lists (category examples and nonsense words) during infusion of propofol to a target concentration of 2 microg ml(-1). Groups 2 and 3 received the word lists during infusion of propofol 5 microg ml(-1). Group 2 received nonsense words before tracheal intubation and category examples during intubation; Group 3 heard category examples before and nonsense words during intubation. Bispectral index was recorded as a measure of depth of sedation/anaesthesia. We assessed explicit memory on recovery using a structured interview and a recognition test. We assessed implicit memory using a category generation test and a preference rating task. To establish baseline, a control group of 12 patients completed the category generation test without receiving the category examples during anaesthesia. Overall, there was no evidence for learning during propofol infusion, though the category generation task showed a trend towards more implicit memory for words presented during intubation than during anaesthesia. We conclude that learning does not occur during anaesthesia without surgery.


Subject(s)
Anesthetics, Intravenous/pharmacology , Memory/drug effects , Propofol/pharmacology , Anesthetics, Intravenous/administration & dosage , Anesthetics, Intravenous/blood , Drug Administration Schedule , Electroencephalography/drug effects , Female , Humans , Infusions, Intravenous , Intubation, Intratracheal , Learning/drug effects , Mental Recall/drug effects , Pilot Projects , Postoperative Period , Propofol/administration & dosage , Propofol/blood , Psychological Tests
13.
Pharmacol Biochem Behav ; 22(2): 297-9, 1985 Feb.
Article in English | MEDLINE | ID: mdl-3983221

ABSTRACT

High-affinity choline uptake (HACU) appears to be the rate-limiting step in the synthesis of the neurotransmitter acetylcholine. The present experiment was designed to examine the effects of irreversible inhibition of HACU by ethylcholine aziridinium chloride (ECA) on passive avoidance retention in mice. Animals were injected intracerebroventricularly, and one-trial passive avoidance retention evaluated 21 days later. A significant retention deficit was observed in ECA-treated animals upon retest 24 hours after training. ECA-induced changes in retention were accompanied by significant reductions in choline acetyltransferase (CAT) activity in only two of seven brain regions tested, hippocampus (48% of control) and cerebellum (76% of control). The results support the involvement of hippocampal cholinergic activity in mediation of passive avoidance learning.


Subject(s)
Avoidance Learning/drug effects , Aziridines/pharmacology , Azirines/pharmacology , Choline/analogs & derivatives , Animals , Brain/enzymology , Choline/pharmacology , Choline O-Acetyltransferase/metabolism , Hippocampus/enzymology , Injections, Intraventricular , Male , Memory/drug effects , Mice
14.
Pharmacol Biochem Behav ; 10(2): 267-71, 1979 Feb.
Article in English | MEDLINE | ID: mdl-572058

ABSTRACT

An increase in stereotyped behavior was observed in rats injected daily with cocaine (40 mg/kg, IP), as compared with the first day. This increase persisted 14 days after discontinuation of the drug treatment, and corresponded to increased levels of 3H-cocaine norcocaine and benzoylecgonine in brain. Pretreatment of the animals with SKF-522A, an inhibitor of cocaine demethylation, produced a decrease in stereotypy rating and concomitantly a lower level of 3H-norcocaine in the brain. The role of this metabolite in the production of cocaine-induced stereotyped behavior is discussed.


Subject(s)
Behavior/drug effects , Cocaine/metabolism , Stereotyped Behavior/drug effects , Animals , Brain Chemistry/drug effects , Cocaine/antagonists & inhibitors , Cocaine/pharmacology , Female , Humans , Proadifen/pharmacology , Rats , Time Factors
15.
Pharmacol Biochem Behav ; 10(2): 273-6, 1979 Feb.
Article in English | MEDLINE | ID: mdl-450938

ABSTRACT

In rats trained to discriminate 10 mg/kg cocaine from 1 mg/kg saline, norcocaine, the N-demethylated metabolite, at doses of 2.5 mg/kg, 5 mg/kg and 10 mg/kg, produced a dose response curve similar to that of cocaine and generalized to cocaine at the two higher doses. As with cocaine, the discriminative stimulus produced by the norcocaine was partially attenuated by the dopaminergic antagonist pimozide and the amine depletor reserpine. Benzoylecgonine, benzoylnorecgonine and ecgonine methyl ester in doses of 10 mg/kg and 20 mg/kg did not generalize to cocaine.


Subject(s)
Cocaine/pharmacology , Discrimination, Psychological/drug effects , Generalization, Psychological/drug effects , Animals , Cocaine/metabolism , Dealkylation , Discrimination Learning/drug effects , Male , Pimozide/pharmacology , Rats , Reinforcement Schedule , Reserpine/pharmacology
17.
Res Commun Chem Pathol Pharmacol ; 17(1): 179-82, 1977 May.
Article in English | MEDLINE | ID: mdl-877402

ABSTRACT

In vitro and in vivo studies in rats indicate cocaine to be metabolized primarily in the liver to form benzoylecgonine and norcocaine. The formation of these metabolites was significantly hindered by SKF-525A, a microsomal enzyme inhibitor. In in vivo studies, pretreatment of rats with SKF-525A prior to receiving cocaine resulted in increased amounts of unchanged cocaine in the brain. No accompanying increase in spontaneous motor activity was observed for these animals, indicating a possible role for metabolites in the stimulant action of cocaine.


Subject(s)
Cocaine/metabolism , Proadifen/pharmacology , Animals , Brain/drug effects , Brain/metabolism , Cocaine/blood , Depression, Chemical , Hydrolysis , In Vitro Techniques , Liver/drug effects , Liver/metabolism , Lung/drug effects , Lung/metabolism , Motor Activity/drug effects , Rats
18.
Res Commun Chem Pathol Pharmacol ; 14(2): 249-57, 1976 Jun.
Article in English | MEDLINE | ID: mdl-940958

ABSTRACT

Hydrolysis of 14C-cocaine in human serum, separation of the metabolites on TLC, and subsequent identification on GLC is described. AT 1 H, 20 percent of the cocaine was metabolized to benzoylecgonine, ecgonine and ecgonine methylester. At this time interval the highest percent of product was in the form of the ecogonine methyl ester, a metabolite not previously reported in humans. After 4 h, 67 percent of the cocaine was hydrolyzed; of this, 45 percent was benzoylecgonine and ecgonine in a ratio of 1.6 to 1. The half-life for cocaine hydrolyzed in human serum was approximately 2.5 h.


Subject(s)
Cocaine/blood , Cocaine/analogs & derivatives , Half-Life , Humans , Hydrolysis , In Vitro Techniques , Time Factors
20.
Res Commun Chem Pathol Pharmacol ; 13(3): 555-8, 1976 Mar.
Article in English | MEDLINE | ID: mdl-935642

ABSTRACT

Norcocaine was prepared from cocaine utilizing diethyl azodicarboxylate. The rate of demethylation of 14C-cocaine in rats receiving either chronic or acute dosages of the drug was investigated. No significant difference in the rate of 14CO2 exhalation from the two groups was observed.


Subject(s)
Cocaine/metabolism , Animals , Carbon Dioxide/metabolism , Cocaine/administration & dosage , Male , Microsomes/metabolism , Oxidoreductases, N-Demethylating/metabolism , Rats
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