50 results on '"Garbe LA"'
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2. Aromatisierung und Modifikation von Trinknahrung für eine bessere Patienten Akzeptanz
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Koch, M, additional and Garbe, LA, additional
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- 2019
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3. Sphäroidkulturen für das Kreuzband-Tissue Engineering
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Hoyer, M, Lohan, A, Breier, A, Hahner, J, Hinüber, C, Ertel, W, Garbe, LA, and Schulze-Tanzil, G
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ddc: 610 ,610 Medical sciences ,Medicine - Abstract
Fragestellung: Zellsphäroide können zur Besiedlung von Scaffolds genutzt werden, da die Zellen fähig sind, ihren Verband wieder zu verlassen und auf die angebotene Matrix auszuwachsen. Ligament Zellen könnten bei der Anzucht in hoher Dichte als dreidimensionale Sphäroidkultur[for full text, please go to the a.m. URL], Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2014)
- Published
- 2014
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4. In-vitro Studie zur individuellen lokalen Freisetzung verschiedener Antibiotika gegen bakterielle Erreger einsatzbedingter Osteomyelitiden
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Back, DA, Calafi, A, Bormann, N, Garbe, LA, Schmidmaier, G, Willy, C, Wildemann, B, Back, DA, Calafi, A, Bormann, N, Garbe, LA, Schmidmaier, G, Willy, C, and Wildemann, B
- Published
- 2014
5. Pharmacological and behavioral investigation of putative self-medicative plants in Budongo chimpanzee diets.
- Author
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Freymann E, Carvalho S, Garbe LA, Dwi Ghazhelia D, Hobaiter C, Huffman MA, Muhumuza G, Schulz L, Sempebwa D, Wald F, Yikii ER, Zuberbühler K, and Schultz F
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- Animals, Plants, Medicinal chemistry, Uganda, Anti-Bacterial Agents pharmacology, Diet veterinary, Behavior, Animal drug effects, Feeding Behavior drug effects, Pan troglodytes, Plant Extracts pharmacology, Plant Extracts chemistry
- Abstract
Wild chimpanzees consume a variety of plants to meet their dietary needs and maintain wellbeing. While some plants have obvious value, others are nutritionally poor and/or contain bioactive toxins which make ingestion costly. In some cases, these nutrient-poor resources are speculated to be medicinal, thought to help individuals combat illness. In this study, we observed two habituated chimpanzee communities living in the Budongo Forest, Uganda, and collected 17 botanical samples associated with putative self-medication behaviors (e.g., bark feeding, dead wood eating, and pith-stripping) or events (e.g., when consumer had elevated parasite load, abnormal urinalysis, or injury). In total, we selected plant parts from 13 species (nine trees and four herbaceous plants). Three extracts of different polarities were produced from each sample using n-hexane, ethyl acetate, and methanol/water (9/1, v/v) and introduced to antibacterial and anti-inflammatory in vitro models. Extracts were evaluated for growth inhibition against a panel of multidrug-resistant clinical isolates of bacteria, including ESKAPE strains and cyclooxygenase-2 (COX-2) inhibition activity. Pharmacological results suggest that Budongo chimpanzees consume several species with potent medicinal properties. In the antibacterial library screen, 45 out of 53 extracts (88%) exhibited ≥40% inhibition at a concentration of 256 μg/mL. Of these active extracts, 41 (91%) showed activity at ≤256μg/mL in subsequent dose-response antibacterial experiments. The strongest antibacterial activity was achieved by the n-hexane extract of Alstonia boonei dead wood against Staphylococcus aureus (IC50: 16 μg/mL; MIC: 32 μg/mL) and Enterococcus faecium (IC50: 16 μg/mL; MIC: >256 μg/mL) and by the methanol-water extract of Khaya anthotheca bark and resin against E. faecium (IC50: 16 μg/mL; MIC: 32 μg/mL) and pathogenic Escherichia coli (IC50: 16 μg/mL; MIC: 256 μg/mL). We observed ingestion of both these species by highly parasitized individuals. K. anthotheca bark and resin were also targeted by individuals with indicators of infection and injuries. All plant species negatively affected growth of E. coli. In the anti-inflammatory COX-2 inhibition library screen, 17 out of 51 tested extracts (33%) showed ≥50% COX-2 inhibition at a concentration of 5 μg/mL. Several extracts also exhibited anti-inflammatory effects in COX-2 dose-response experiments. The K. anthotheca bark and resin methanol-water extract showed the most potent effects (IC50: 0.55 μg/mL), followed by the fern Christella parasitica methanol-water extract (IC50: 0.81 μg/mL). This fern species was consumed by an injured individual, a feeding behavior documented only once before in this population. These results, integrated with associated observations from eight months of behavioral data, provide further evidence for the presence of self-medicative resources in wild chimpanzee diets. This study addresses the challenge of distinguishing preventative medicinal food consumption from therapeutic self-medication by integrating pharmacological, observational, and health monitoring data-an essential interdisciplinary approach for advancing the field of zoopharmacognosy., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Freymann et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2024
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6. Re-assessment of monoclonal antibodies against diclofenac for their application in the analysis of environmental waters.
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Schmidt S, Hoffmann H, Garbe LA, Harrer A, Steiner M, Himly M, and Schneider RJ
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- Environmental Monitoring methods, Wastewater chemistry, Diclofenac analysis, Diclofenac chemistry, Antibodies, Monoclonal chemistry, Water Pollutants, Chemical analysis, Enzyme-Linked Immunosorbent Assay methods, Anti-Inflammatory Agents, Non-Steroidal analysis
- Abstract
The non-steroidal anti-inflammatory drug (NSAID) diclofenac (DCF) is an important environmental contaminant occurring in surface waters all over the world, because, after excretion, it is not adequately removed from wastewater in sewage treatment plants. To be able to monitor this pollutant, highly efficient analytical methods are needed, including immunoassays. In a medical research project, monoclonal antibodies against diclofenac and its metabolites had been produced. Based on this monoclonal anti-DCF antibody, a new indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed and applied for environmental samples. The introduction of a spacer between diclofenac and the carrier protein in the coating conjugate led to higher sensitivity. With a test midpoint of 3 μg L
-1 and a measurement range of 1-30 μg L-1 , the system is not sensitive enough for direct analysis of surface water. However, this assay is quite robust against matrix influences and can be used for wastewater. Without adjustment of the calibration, organic solvents up to 5%, natural organic matter (NOM) up to 10 mg L-1 , humic acids up to 2.5 mg L-1 , and salt concentrations up to 6 g L-1 NaCl and 75 mg L-1 CaCl2 are tolerated. The antibody is also stable in a pH range from 3 to 12. Cross-reactivity (CR) of 1% or less was determined for the metabolites 4'-hydroxydiclofenac (4'-OH-DCF), 5-hydroxydiclofenac (5-OH-DCF), DCF lactam, and other NSAIDs. Relevant cross-reactivity occurred only with an amide derivative of DCF, 6-aminohexanoic acid (DCF-Ahx), aceclofenac (ACF) and DCF methyl ester (DCF-Me) with 150%, 61% and 44%, respectively. These substances, however, have not been found in samples. Only DCF-acyl glucuronide with a cross-reactivity of 57% is of some relevance. For the first time, photodegradation products were tested for cross-reactivity. With the ELISA based on this antibody, water samples were analysed. In sewage treatment plant effluents, concentrations in the range of 1.9-5.2 μg L-1 were determined directly, with recoveries compared to HPLC-MS/MS averaging 136%. Concentrations in lakes ranged from 3 to 4.4 ng L-1 and were, after pre-concentration, determined with an average recovery of 100%.- Published
- 2024
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7. How to approach a study in ethnopharmacology? Providing an example of the different research stages for newcomers to the field today.
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Schultz F and Garbe LA
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- Animals, Ethnopharmacology methods, Ethnobotany, Surveys and Questionnaires, Research Design, Plants, Medicinal
- Abstract
Ethnopharmacology seeks to investigate humankind's use of natural materials, such as plants, fungi, microorganisms, animals, and minerals, for medicinal purposes. In this highly interdisciplinary field, which can be described as a bridge between the natural/medical and socio-cultural sciences, pharmacological, anthropological, and socio-cultural research methods are often applied, along with methods from other branches of science. When entering the field of ethnopharmacology as a newcomer, student, or early career researcher today, the tremendous amount of scientific publications, and even classical books from this field and related scientific disciplines, can be overwhelming. Ethnopharmacology has evolved over the past decades, and new key topics, such as the decolonization of the field, issues on intellectual property and benefit-sharing, species conservation, the preservation of traditional knowledge, the protection of indigenous communities, science outreach, and climate change, have become important and urgent aspects of the field that must not be disregarded by today's ethnopharmacologists. One of the questions of newcomers will be, "Where to begin?" This review article offers a brief (and certainly not comprehensive) introduction to the science of ethnopharmacology, highlighting some of its past most notable achievements and future prospects. In addition, this article provides an example for newcomers to the field of how to address different stages that may be involved in conducting ethnopharmacological field and lab studies, including early-stage drug discovery and community work. The example presented summarizes a series of studies conducted in the remote Greater Mpigi region of Uganda, located in East Africa. Stages of ethnopharmacological research described include ethnobotanical surveying and fieldwork, the pharmacological assessment of activity with diverse targets in the laboratory, and the transfer of results back to indigenous communities, that is, non-financial benefit sharing as a potential best practice example. As a result of this research example, a total of six original research articles have been published on the medicinal application and ethnopharmacology of 16 plant species from the Ugandan study site, offering a large quantity of results. These six publications reflect the multifaceted nature of the interdisciplinary science of ethnopharmacology, which may serve as a reference point and inspiration for newcomers to design and conduct their own independent ethnopharmacological research endeavors at other study sites. Major bottlenecks and solutions are provided, and the current social media channels with educational ethnopharmacological content are briefly introduced., (© 2023 The Authors. Pharmacology Research & Perspectives published by British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics and John Wiley & Sons Ltd.)
- Published
- 2023
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8. Combined Application of Tacrolimus with Cyproconazole, Hymexazol and Novel {2-(3-R-1 H -1,2,4-triazol-5-yl)phenyl}amines as Antifungals: In Vitro Growth Inhibition and In Silico Molecular Docking Analysis to Fungal Chitin Deacetylase.
- Author
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Antypenko L, Meyer F, Sadyk Z, Shabelnyk K, Kovalenko S, Steffens KG, and Garbe LA
- Abstract
Agents with antifungal activity play a vital role as therapeutics in health care, as do fungicides in agriculture. Effectiveness, toxicological profile, and eco-friendliness are among the properties used to select suitable substances. Furthermore, a steady supply of new agents with different modes of action is required to counter the well-known potential of human and phyto-pathogenic fungi to develop resistance against established antifungals. Here, we use an in vitro growth assay to investigate the activity of the calcineurin inhibitor tacrolimus in combination with the commercial fungicides cyproconazole and hymexazol, as well as with two earlier reported novel {2-(3-R-1 H -1,2,4-triazol-5-yl)phenyl}amines, against the fungi Aspergillus niger , Colletotrichum higginsianum , Fusarium oxysporum and the oomycete Phytophthora infestans , which are notoriously harmful in agriculture. When tacrolimus was added in a concentration range from 0.25 to 25 mg/L to the tested antifungals (at a fixed concentration of 25 or 50 mg/L), the inhibitory activities were distinctly enhanced. Molecular docking calculations revealed triazole derivative 5 , (2-(3-adamantan-1-yl)-1 H -1,2,4-triazol-5-yl)-4-chloroaniline), as a potent inhibitor of chitin deacetylases (CDA) of Aspergillus nidulans and A. niger ( An CDA and Ang CDA, respectively), which was stronger than the previously reported polyoxorin D, J075-4187, and chitotriose. The results are discussed in the context of potential synergism and molecular mode of action.
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- 2023
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9. Malnutrition Is Highly Prevalent in Patients With Chronic Pancreatitis and Characterized by Loss of Skeletal Muscle Mass but Absence of Impaired Physical Function.
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Wiese ML, Gärtner S, von Essen N, Doller J, Frost F, Tran QT, Weiss FU, Meyer F, Valentini L, Garbe LA, Metges CC, Bannert K, Sautter LF, Ehlers L, Jaster R, Lamprecht G, Steveling A, Lerch MM, and Aghdassi AA
- Abstract
Background/aims: Patients with chronic pancreatitis (CP) have an increased risk of malnutrition, a condition linked to reduced muscle mass and physical performance. We have investigated the risk factors, phenotypic presentation, and health implications associated with malnutrition in CP., Materials and Methods: In a multicenter cross-sectional study we recruited patients with confirmed CP and healthy volunteers as a control group. Malnutrition was diagnosed according to the criteria proposed by the Global Leadership Initiative on Malnutrition. We performed detailed examinations of body composition and physical function as well as testing of routine blood parameters and markers of inflammation., Results: We included 66 patients [mean (±SD) age: 56.0 (±14.5) years; 51 males] and an equal number of age- and sex-matched controls. Moderate malnutrition was diagnosed in 21% ( n = 14) and severe malnutrition in 42% ( n = 28) of patients. Besides weight loss malnourished patients showed lower fat and skeletal muscle mass compared to both non-malnourished subjects and healthy controls. Only in severe malnutrition, blood parameters reflected elevated inflammation and reduced muscle reserves. Handgrip strength in patients did not differ by nutritional status but there was a significant correlation (rho = 0.705, p < 0.001) with skeletal muscle mass. Although 20 patients (30%) had pathologically reduced skeletal muscle mass, only two individuals (3%) had sarcopenia with concomitantly reduced handgrip strength., Conclusion: Malnutrition is a frequent complication of CP characterized by loss of skeletal muscle mass. As this condition becomes evident only at an advanced stage, regular testing for altered body composition is recommended. Suitable biomarkers and the link between loss of muscle mass and physical function require further investigation., Clinical Trial Registration: [https://clinicaltrials.gov/ct2/show/NCT04474743], identifier [NCT04474743]., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wiese, Gärtner, von Essen, Doller, Frost, Tran, Weiss, Meyer, Valentini, Garbe, Metges, Bannert, Sautter, Ehlers, Jaster, Lamprecht, Steveling, Lerch and Aghdassi.)
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- 2022
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10. Pharmacological Assessment of the Antiprotozoal Activity, Cytotoxicity and Genotoxicity of Medicinal Plants Used in the Treatment of Malaria in the Greater Mpigi Region in Uganda.
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Schultz F, Osuji OF, Nguyen A, Anywar G, Scheel JR, Caljon G, Pieters L, and Garbe LA
- Abstract
We investigated the potential antimalarial and toxicological effects of 16 medicinal plants frequently used by traditional healers to treat malaria, fever, and related disorders in the Greater Mpigi region in Uganda. Species studied were Albizia coriaria , Cassine buchananii , Combretum molle , Erythrina abyssinica , Ficus saussureana , Harungana madagascariensis , Leucas calostachys , Microgramma lycopodioides , Morella kandtiana , Plectranthus hadiensis , Securidaca longipedunculata , Sesamum calycinum subsp. angustifolium , Solanum aculeastrum , Toddalia asiatica , Warburgia ugandensis, and Zanthoxylum chalybeum . In addition, the traditional healers indicated that P. hadiensis is used as a ritual plant to boost fertility and prepare young women and teenagers for motherhood in some Ugandan communities where a high incidence of rapidly growing large breast masses in young female patients was observed (not necessarily breast cancer). We present results from various in vitro experiments performed with 56 different plant extracts, namely, 1) an initial assessment of the 16 species regarding their traditional use in the treatment of malaria by identifying promising plant extract candidates using a heme biocrystallization inhibition library screen; 2) follow-up investigations of antiprotozoal effects of the most bioactive crude extracts against chloroquine-resistant P. falciparum K1; 3) a cytotoxicity counterscreen against human MRC-5
SV2 lung fibroblasts; 4) a genotoxicity evaluation of the extract library without and with metabolic bioactivation with human S9 liver fraction; and 5) an assessment of the mutagenicity of the ritual plant P. hadiensis . A total of seven extracts from five plant species were selected for antiplasmodial follow-up investigations based on their hemozoin formation inhibition activity in the heme biocrystallization assay. Among other extracts, an ethyl acetate extract of L. calostachys leaves exhibited antiplasmodial activity against P. falciparum K1 (IC50 value: 5.7 µg/ml), which was further characterized with a selectivity index of 2.6 (CC50 value: 14.7 µg/ml). The experiments for assessment of potential procarcinogenic properties of plant extracts via evaluation of in vitro mutagenicity and genotoxicity indicated that few extracts cause mutations. The species T. asiatica showed the most significant genotoxic effects on both bacterial test strains (without metabolic bioactivation at a concentration of 500 µg/plate). However, none of the mutagenic extracts from the experiments without metabolic bioactivation retained their genotoxic activity after metabolic bioactivation of the plant extract library through pre-incubation with human S9 liver fraction. While this study did not show that P. hadiensis has genotoxic properties, it did provide early stage support for the therapeutic use of the medicinal plants from the Greater Mpigi region., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Schultz, Osuji, Nguyen, Anywar, Scheel, Caljon, Pieters and Garbe.)- Published
- 2021
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11. Antiinflammatory Medicinal Plants from the Ugandan Greater Mpigi Region Act as Potent Inhibitors in the COX-2/PGH 2 Pathway.
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Schultz F, Osuji OF, Wack B, Anywar G, and Garbe LA
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Our study investigates 16 medicinal plants via assessment of inhibition of proinflammatory enzymes such as cyclooxygenases (COX). The plants are used by traditional healers in the Greater Mpigi region in Uganda to treat inflammation and related disorders. We present results of diverse in vitro experiments performed with 76 different plant extracts, namely, (1) selective COX-2 and COX-1 inhibitor screening; (2) 15-LOX inhibition screening; (3) antibacterial resazurin assay against multidrug-resistant Staphylococcus aureus , Listeria innocua , Listeria monocytogenes , and Escherichia coli K12; (4) DPPH assay for antioxidant activity; and (5) determination of the total phenolic content (TPC). Results showed a high correlation between traditional use and pharmacological activity, e.g., extracts of 15 out of the 16 plant species displayed significant selective COX-2 inhibition activity in the PGH
2 pathway. The most active COX-2 inhibitors (IC50 < 20 µg/mL) were nine extracts from Leucas calostachys , Solanum aculeastrum, Sesamum calycinum subsp. angustifolium , Plectranthus hadiensis , Morella kandtiana , Zanthoxylum chalybeum , and Warburgia ugandensis . There was no counteractivity between COX-2 and 15-LOX inhibition in these nine extracts. The ethyl acetate extract of Leucas calostachys showed the lowest IC50 value with 0.66 µg/mL (COX-2), as well as the most promising selectivity ratio with 0.1 (COX-2/COX-1). The TPCs and the EC50 values for DPPH radical scavenging activity showed no correlation with COX-2 inhibitory activity. This led to the assumption that the mechanisms of action are most likely not based on scavenging of reactive oxygen species and antioxidant activities. The diethyl ether extract of Harungana madagascariensis stem bark displayed the highest growth inhibition activity against S. aureus (MIC value: 13 µg/mL), L. innocua (MIC value: 40 µg/mL), and L. monocytogenes (MIC value: 150 µg/mL). This study provides further evidence for the therapeutic use of the previously identified plants used medicinally in the Greater Mpigi region.- Published
- 2021
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12. A Bibliographic Assessment Using the Degrees of Publication Method: Medicinal Plants from the Rural Greater Mpigi Region (Uganda).
- Author
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Schultz F, Anywar G, Quave CL, and Garbe LA
- Abstract
In ethnopharmacological research, many field assessment tools exist. Yet, these miss that critical point of how to really determine which species merit the costly lab studies, e.g., evaluation of traditional use via pharmacological assays and isolation of bioactive secondary metabolites. This gap can be filled with the introduction of a new tool for literature assessment: the Degrees of Publication (DoPs). In this study, its application is illustrated through an extensive bibliographic assessment of 16 medicinal plant species that were recently identified in the Greater Mpigi region of Uganda as being frequently used by local traditional healers in the treatment of medical disorders (namely, Albizia coriaria , Cassine buchananii , Combretum molle , Erythrina abyssinica , Ficus saussureana , Harungana madagascariensis , Leucas calostachys , Microgramma lycopodioides , Morella kandtiana , Plectranthus hadiensis , Securidaca longipedunculata , Sesamum calycinum subsp. angustifolium , Solanum aculeastrum , Toddalia asiatica , Warburgia ugandensis, and Zanthoxylum chalybeum ). These species are suspected to be understudied, and a thorough bibliographic assessment has not been previously performed. Thus, the objectives of our study were to undertake a comparative assessment of the degree to which each of these plant species has been studied in the past, including evaluation of the quality of the journals where results were published in. The determination of the DoPs enabled successful assessment of the degrees to which each individual plant species has been studied so far, while also taking into account the methodological "research chain of ethnopharmacology" from ethnobotanical studies ("traditional use") to pharmacological assays ("bioactivity") and finally to pharmacognostic research ("structure elucidation"). The significance of a research paper was assessed by determining whether its journal and publishing house were members of the Committee on Publication Ethics (COPE). In total, 634 peer-reviewed publications were reviewed covering the period of 1960-2019, 53.3% of which were published in journals and by publishing houses affiliated with COPE (338 publications). The literature assessment resulted in the identification of understudied plants among the selected species. The majority of plants reviewed have not been sufficiently studied; six species were classified as being highly understudied and three more as being understudied: C. buchananii , F. saussureana , L. calostachys , M. lycopodioides , M. kandtiana , and S. calycinum subsp. angustifolium and A. coriaria , P. hadiensis, and S. aculeastrum, respectively. The newly introduced DoPs are a useful tool for the selection of traditionally used species for future laboratory studies, especially for pharmacological bioassays, isolation procedures, and drug discovery strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as potential conflicts of interest., (Copyright © 2021 Fabien Schultz et al.)
- Published
- 2021
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13. Molecular Mechanism Contributing to Malnutrition and Sarcopenia in Patients with Liver Cirrhosis.
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Meyer F, Bannert K, Wiese M, Esau S, Sautter LF, Ehlers L, Aghdassi AA, Metges CC, Garbe LA, Jaster R, Lerch MM, Lamprecht G, and Valentini L
- Subjects
- Humans, Liver Cirrhosis complications, Liver Cirrhosis metabolism, Liver Cirrhosis pathology, Malnutrition etiology, Malnutrition metabolism, Malnutrition pathology, Muscle, Skeletal metabolism, Muscle, Skeletal pathology, Sarcopenia etiology, Sarcopenia metabolism, Sarcopenia pathology
- Abstract
Liver cirrhosis is frequently accompanied by disease-related malnutrition (DRM) and sarcopenia, defined as loss of skeletal muscle mass and function. DRM and sarcopenia often coexist in cirrhotic patients and are associated with increased morbidity and mortality. The clinical manifestation of both comorbidities are triggered by multifactorial mechanisms including reduced nutrient and energy intake caused by dietary restrictions, anorexia, neuroendocrine deregulation, olfactory and gustatory deficits. Maldigestion and malabsorption due to small intestinal bacterial overgrowth, pancreatic insufficiency or cholestasis may also contribute to DRM and sarcopenia. Decreased protein synthesis and increased protein degradation is the cornerstone mechanism to muscle loss, among others mediated by disease- and inflammation-mediated metabolic changes, hyperammonemia, increased myostatin and reduced human growth hormone. The concise pathophysiological mechanisms and interactions of DRM and sarcopenia in liver cirrhosis are not completely understood. Furthermore, most knowledge in this field are based on experimental models, but only few data in humans exist. This review summarizes known and proposed molecular mechanisms contributing to malnutrition and sarcopenia in liver cirrhosis and highlights remaining knowledge gaps. Since, in the prevention and treatment of DRM and sarcopenia in cirrhotic patients, more research is needed to identify potential biomarkers for diagnosis and development of targeted therapeutic strategies.
- Published
- 2020
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14. Targeting ESKAPE pathogens with anti-infective medicinal plants from the Greater Mpigi region in Uganda.
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Schultz F, Anywar G, Tang H, Chassagne F, Lyles JT, Garbe LA, and Quave CL
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- Anti-Infective Agents chemistry, Bacterial Infections drug therapy, Bacterial Infections microbiology, Cell Survival drug effects, Chromatography, Liquid, Dose-Response Relationship, Drug, Humans, Keratinocytes drug effects, Keratinocytes metabolism, Mass Spectrometry, Microbial Sensitivity Tests, Plant Extracts chemistry, Quorum Sensing drug effects, Staphylococcus aureus drug effects, Uganda, Anti-Infective Agents pharmacology, Drug Resistance, Multiple, Bacterial drug effects, Plant Extracts pharmacology, Plants, Medicinal chemistry
- Abstract
Antibiotic resistance poses one of the greatest threats to global health today; conventional drug therapies are becoming increasingly inefficacious and limited. We identified 16 medicinal plant species used by traditional healers for the treatment of infectious and inflammatory diseases in the Greater Mpigi region of Uganda. Extracts were evaluated for their ability to inhibit growth of clinical isolates of multidrug-resistant ESKAPE pathogens. Extracts were also screened for quorum quenching activity against S. aureus, including direct protein output assessment (δ-toxin), and cytotoxicity against human keratinocytes (HaCaT). Putative matches of compounds were elucidated via LC-FTMS for the best-performing extracts. These were extracts of Zanthoxylum chalybeum (Staphylococcus aureus: MIC: 16 μg/mL; Enterococcus faecium: MIC: 32 μg/mL) and Harungana madagascariensis (S. aureus: MIC: 32 μg/mL; E. faecium: MIC: 32 μg/mL) stem bark. Extracts of Solanum aculeastrum root bark and Sesamum calycinum subsp. angustifolium leaves exhibited strong quorum sensing inhibition activity against all S. aureus accessory gene regulator (agr) alleles in absence of growth inhibition (IC
50 values: 1-64 μg/mL). The study provided scientific evidence for the potential therapeutic efficacy of these medicinal plants in the Greater Mpigi region used for infections and wounds, with 13 out of 16 species tested being validated with in vitro studies.- Published
- 2020
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15. Ethnobotanical study of selected medicinal plants traditionally used in the rural Greater Mpigi region of Uganda.
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Schultz F, Anywar G, Wack B, Quave CL, and Garbe LA
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- Adult, Aged, Ethnobotany methods, Female, Humans, Male, Middle Aged, Phytotherapy methods, Rural Population, Surveys and Questionnaires, Uganda, Young Adult, Plant Preparations therapeutic use, Plants, Medicinal chemistry
- Abstract
Ethnopharmacological Relevance: This study provides the first report on selected traditional medicinal plant use, including parts used and methods of preparation, in the Greater Mpigi region of Uganda. This data supports the conservation of local traditional ecological knowledge and will facilitate future drug discovery research., Aim of the Study: Our study aimed to conserve culturally and scientifically-valuable medical knowledge of 16 plant species traditionally used in the Greater Mpigi region in Uganda, namely Albizia coriaria, Cassine buchananii, Combretum molle, Erythrina abyssinica, Ficus saussureana, Harungana madagascariensis, Leucas calostachys, Microgramma lycopodioides, Morella kandtiana, Plectranthus hadiensis, Securidaca longipedunculata, Sesamum calycinum subsp. angustifolium, Solanum aculeastrum, Toddalia asiatica, Warburgia ugandensis and Zanthoxylum chalybeum. An additional objective of the study was an ethnological investigation of the socio-cultural background and medical understanding of diseases treated by traditional healers in the study area., Materials and Methods: A pilot survey in the study area revealed that 16 plant species were frequently used in treatment of a variety of medical disorders. In order to obtain more complete information, we conducted a broader ethnobotanical survey using structured interviews with 39 traditional healers from 29 villages, specifically asking about the traditional uses of these 16 medicinal species., Results: Results of the survey confirmed a high level of traditional use of these species in the Greater Mpigi region. In addition, various other traditional uses and methods of preparation were recorded, most of them for the first time. In total, 75 different medical disorders treated with the plants were documented., Conclusions: Conservation of traditional knowledge for future generations is vital, as loss has already been recorded due to multiple causes. The need for novel and more effective drugs derived from natural products is more important than ever, making future studies on herbal remedies both justified and urgently required. The traditional healers surveyed in this project also have expectations of the research - they would like to be updated about any resulting studies into the pharmacological efficacy of medicinal plants so that the research findings can inform their confidence in each herbal remedy., Competing Interests: Declaration of competing interest This study was performed according to the international, national and institutional rules considering the Convention on Biodiversity and the Nagoya Protocol. Informed consent was requested and obtained from all participants of the ethnobotanical survey. All results from future lab work on mentioned plants will be transferred back to traditional healers and survey participants through workshops. The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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16. Tacrolimus as Antifungal Agent.
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Antypenko L, Meyer F, Sadykova Z, Garbe LA, and Steffens KG
- Abstract
Tacrolimus (FK506) is an immunosuppressant drug widely used to avoid organ rejection in transplant patients. It has a profound influence on the cellular stress response by interfering with the calmodulin-calcineurin signaling pathway. In this context FK506 also became a valuable antifungal drug in medical care. Here it is shown in vitro that tacrolimus has a potent growth inhibition activity against 11 fungi and 3 oomycetes of agricultural importance. The significance of this finding is discussed with respect to crop protection. The in silico molecular docking to 6 major antifungal enzymes determined UDP-N-acetylmuramoyl-L-alanine: D-glutamate ligase (MurD) as the main target by the best affinity score.
- Published
- 2019
17. Synthesis and mode of action studies of novel {2-(3-R-1H-1,2,4-triazol-5-yl)phenyl}amines to combat pathogenic fungi.
- Author
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Antypenko L, Sadykova Z, Shabelnyk K, Meyer F, Kovalenko S, Meyer V, Garbe LA, and Steffens K
- Subjects
- Antifungal Agents chemistry, Antifungal Agents pharmacology, Antifungal Agents toxicity, Microbial Sensitivity Tests, Mitosporic Fungi growth & development, Molecular Docking Simulation, Molecular Structure, Salmonella typhimurium drug effects, Salmonella typhimurium genetics, Structure-Activity Relationship, Triazoles chemistry, Triazoles pharmacology, Triazoles toxicity, Antifungal Agents chemical synthesis, Drug Design, Mitosporic Fungi drug effects, Triazoles chemical synthesis
- Abstract
Due to their high specificity and efficacy, triazoles have become versatile antifungals to treat fungal infections in human healthcare and to control phytopathogenic fungi in agriculture. However, azole resistance is an emerging problem affecting human health as well as food security. Here we describe the synthesis of 10 novel {2-(3-R-1H-1,2,4-triazol-5-yl)phenyl}amines. Their structure was ascertained by liquid chromatography-mass spectrometry,
1 H and13 C NMR, and elemental analysis data. Applying an in vitro growth assay, these triazoles show moderate to significant antifungal activity against the opportunistic pathogen Aspergillus niger, 12 fungi (Fusarium oxysporum, Fusarium fujikuroi, Colletotrichum higginsianum, Gaeumannomyces graminis, Colletotrichum coccodes, Claviceps purpurea, Alternaria alternata, Mucor indicus, Fusarium graminearum, Verticillium lecanii, Botrytis cinerea, Penicillium digitatum) and three oomycetes (Phytophtora infestans GL-1, P. infestans 4/91; R+ and 4/91; R-) in the concentration range from 1 to 50 µg/ml (0.003-2.1 μM). Frontier molecular orbital energies were determined to predict their genotoxic potential. Molecular docking calculations taking into account six common fungal enzymes point to 14α-demethylase (CYP51) and N-myristoyltransferase as the most probable fungal targets. With respect to effectiveness, structure-activity calculations revealed the strong enhancing impact of adamantyl residues. The shown nonmutagenicity in the Salmonella reverse-mutagenicity assay and no violations of drug-likeness parameters suggest the good bioavailability and attractive ecotoxicological profile of the studied triazoles., (© 2019 Deutsche Pharmazeutische Gesellschaft.)- Published
- 2019
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18. Novel acyl thiourea derivatives: Synthesis, antifungal activity, gene toxicity, drug-like and molecular docking screening.
- Author
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Antypenko L, Meyer F, Kholodniak O, Sadykova Z, Jirásková T, Troianova A, Buhaiova V, Cao S, Kovalenko S, Garbe LA, and Steffens KG
- Subjects
- Antifungal Agents chemical synthesis, Antifungal Agents chemistry, Chromatography, Liquid methods, Magnetic Resonance Spectroscopy, Mass Spectrometry methods, Mutagenicity Tests, Salmonella drug effects, Salmonella genetics, Structure-Activity Relationship, Thiourea analogs & derivatives, Thiourea chemical synthesis, Antifungal Agents pharmacology, Molecular Docking Simulation, Thiourea pharmacology
- Abstract
Nine novel acyl thioureas were synthesized. Their identities and purities were confirmed by LC-MS spectra; each structure was elucidated by elemental analysis, IR,
1 Н and13 C NMR spectra. Applying an in vitro screening of their antifungal potential, three substances (3, 5, and 6) could be selected as showing high activity against 11 fungi and 3 Phytophthora strains of phytopathogenic significance. Analysis of gene toxicity with the Salmonella reverse mutagenicity test, as an assessment of drug likeness, lipophilicity, and calculations of frontier molecular orbitals assign a low toxicity profile to these compounds. Molecular docking studies point to 14α-demethylase (CYP51) and N-myristoyltransferase (NMT) as possible fungal targets for growth inhibition. The findings are discussed with respect to structure-activity relationship (SAR)., (© 2018 Deutsche Pharmazeutische Gesellschaft.)- Published
- 2019
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19. Monomethyl Suberate Screening for Antifungal Activity, Molecular Docking and Drug-Like Properties.
- Author
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Antypenko L, Hassan FA, Sadykova Z, Garbe LA, and Steffens KG
- Abstract
Antifungal activity of suberic acid monomethyl ester (monomethyl suberate) was investigated in a growth inhibition assay comprising of 11 different fungi and 3 Phytophthora oomycetes strains relevant in agriculture. In comparison to standard antifungal hymexazol, monomethyl suberate showed moderate antifungal effects at a concentration range of 100-300 µg/mL. Alternaria alternata, Fusarium equiseti, Fusarium fujikuroi and Phytophtora infestans GL-1 were the most sensitive fungi showing inhibition rates up to 100 %. Physico-chemical descriptors of monomethyl suberate revealed its low toxicity profile. Molecular docking analysis comprising several known antifungal targets points to the N-myristoyltransferase as the most probable site of interaction.
- Published
- 2018
20. Liquid chromatography-tandem mass spectrometry detection of diclofenac and related compounds in water samples.
- Author
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Schmidt S, Hoffmann H, Garbe LA, and Schneider RJ
- Subjects
- Diclofenac analogs & derivatives, Europe, Limit of Detection, Sewage chemistry, Chromatography, Liquid, Diclofenac analysis, Environmental Monitoring methods, Tandem Mass Spectrometry, Water chemistry, Water Pollutants, Chemical analysis
- Abstract
A frequently studied environmental contaminant is the active substance diclofenac, which is removed insufficiently in sewage treatment plants. Since its inclusion in the watch list of the EU Water Framework Directive, the concentrations in surface waters will be determined throughout Europe. For this, still, more precise analytical methods are needed. As a reference, HPLC-MS is frequently employed. One of the major metabolites is 4'-hydroxydiclofenac (4'-OH-DCF). Also, diclofenac lactam is important for assessing degradation and transformation. Aceclofenac (ACF), the glycolic acid ester of diclofenac is used as a drug, too, and could potentially be cleaved to yield diclofenac again. In various sewage treatment plant influent samples, diclofenac, 4'-OH-DCF, DCF lactam and ACF could be determined with detection limits of 3 μg/L, 0.2 μg/L, 0.17 μg/L and 10 ng/L, respectively., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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21. Studies on the development of antibodies for the highly hydrophobic plasticizers DINCH and DEHT.
- Author
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Baldofski S, Canitz CJ, Garbe LA, and Schneider RJ
- Subjects
- Animals, Antibodies immunology, Cyclohexanecarboxylic Acids immunology, Dicarboxylic Acids immunology, Enzyme-Linked Immunosorbent Assay, High-Throughput Screening Assays, Hydrophobic and Hydrophilic Interactions, Phthalic Acids immunology, Rabbits, Antibodies chemistry, Cyclohexanecarboxylic Acids chemistry, Dicarboxylic Acids chemistry, Phthalic Acids chemistry, Plasticizers chemistry
- Abstract
Diisononylcyclohexane-1,2-dicarboxylate (DINCH) and di-2-ethylhexyl terephthalate (DEHT), two of the most important substitutes for phthalate plasticizers, are used for a wide range of applications. Consequently, an increasing occurrence in urine and environmental samples is reported. Reliable and fast analytical methods for the quantification of these plasticizers are needed. So far, mainly GC-MS or LC-MS methods are used. We aimed to develop the first antibodies and immunoassays allowing for high-throughput analysis of samples. We designed two DINCH hapten structures and one DEHT hapten structure and employed hapten-protein conjugates for the immunization of rabbits. Sensitive competitive enzyme-linked immunosorbent assays (ELISAs) against each hapten using the produced polyclonal antibodies were established. Yet, binding of DINCH to the respective antibodies was not observed in neither direct nor indirect assay formats, even when using protein conjugates with the heterologous haptens and different carrier proteins in the indirect format. The use of surfactants and solvents in the sample buffer did not result in recognition of the plasticizers. Also, no binding of DEHT in ELISA employing the respective antibodies was detected. We speculate that the production of antibodies against these highly hydrophobic molecules is not possible via our route, however a different hapten design could overcome this obstacle., (Copyright © 2017 Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
- View/download PDF
22. Application of fluorescence polarization immunoassay for determination of carbamazepine in wastewater.
- Author
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Oberleitner L, Dahmen-Levison U, Garbe LA, and Schneider RJ
- Subjects
- Anticonvulsants, Biological Assay, Wastewater, Carbamazepine, Fluorescence Polarization Immunoassay
- Abstract
Carbamazepine is an antiepileptic drug that can be used as a marker for the cleaning efficiency of wastewater treatment plants. Here, we present the optimization of a fast and easy on-site measurement system based on fluorescence polarization immunoassay and the successful application to wastewater. A new monoclonal highly specific anti-carbamazepine antibody was applied. The automated assay procedure takes 16 min and does not require sample preparation besides filtration. The recovery rates for carbamazepine in wastewater samples were between 60.8 and 104% with good intra- and inter-assay coefficients of variations (less than 15 and 10%, respectively). This automated assay enables for the on-site measurement of carbamazepine in wastewater treatment plants., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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23. Enzyme-linked immunosorbent assay (ELISA) for the anthropogenic marker isolithocholic acid in water.
- Author
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Baldofski S, Hoffmann H, Lehmann A, Breitfeld S, Garbe LA, and Schneider RJ
- Subjects
- Bile Acids and Salts chemistry, Calibration, Chromatography, Liquid, Feces, Tandem Mass Spectrometry, Waste Disposal, Fluid, Environmental Monitoring methods, Enzyme-Linked Immunosorbent Assay methods, Lithocholic Acid analysis, Wastewater chemistry, Water Pollutants, Chemical analysis, Water Purification methods
- Abstract
Bile acids are promising chemical markers to assess the pollution of water samples with fecal material. This study describes the optimization and validation of a direct competitive enzyme-linked immunosorbent assay for the bile acid isolithocholic acid (ILA). The quantification range of the optimized assay was between 0.09 and 15 μg/L. The assay was applied to environmental water samples. Most studies until now were focused on bile acid fractions in the particulate phase of water samples. In order to avoid tedious sample preparation, we undertook to evaluate the dynamics and significance of ILA levels in the aqueous phase. Very low concentrations in tap and surface water samples made a pre-concentration step necessary for this matrix as well as for wastewater treatment plant (WWTP) effluent. Mean recoveries for spiked water samples were between 97% and 109% for tap water and WWTP influent samples and between 102% and 136% for WWTP effluent samples. 90th percentiles of intra-plate and inter-plate coefficients of variation were below 10% for influents and below 20% for effluents and surface water. ILA concentrations were quantified in the range of 33-72 μg/L in influent, 21-49 ng/L in effluent and 18-48 ng/L in surface water samples. During wastewater treatment the ILA levels were reduced by more than 99%. ILA concentrations of influents determined by ELISA and LC-MS/MS were in good agreement. However, findings in LC-ELISA experiments suggest that the true ILA levels in concentrated samples are lower due to interfering effects of matrix compounds and/or cross-reactants. Yet, the ELISA will be a valuable tool for the performance check and comparison of WWTPs and the localization of fecal matter input into surface waters., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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24. Simple Preparation of Rhodococcus erythropolis DSM 44534 as Biocatalyst to Oxidize Diols into the Optically Active Lactones.
- Author
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Martinez-Rojas E, Olejniczak T, Neumann K, Garbe LA, and Boratyñski F
- Subjects
- Biotransformation, Catalysis, Rhodococcus metabolism, Stereoisomerism, Green Chemistry Technology methods, Lactones chemistry, Rhodococcus chemistry
- Abstract
In the current study, we present a green toolbox to produce ecological compounds like lactone moiety. Rhodococcus erythropolis DSM 44534 cells have been used to oxidize both decane-1,4-diol () and decane-1,5-diol () into the corresponding γ- () and δ-decalactones () with yield of 80% and enantiomeric excess (ee) = 75% and ee = 90%, respectively. Among oxidation of meso diols, (-)-(1S,5R)-cis-3-oxabicyclo[4.3.0]non-7-en-2-one (5a) with 56% yield and ee = 76% as well as (-)-(2R,3S)-cis-endo-3-oxabicyclo[2.2.1]dec-7-en-2-one (6a) with 100% yield and ee = 90% were formed. It is worth mentioning that R. erythropolis DSM 44534 grew in a mineral medium containing ethanol as the sole source of energy and carbon Chirality 28:623-627, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)
- Published
- 2016
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25. Testing of antibiotic releasing implant coatings to fight bacteria in combat-associated osteomyelitis - an in-vitro study.
- Author
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Back DA, Bormann N, Calafi A, Zech J, Garbe LA, Müller M, Willy C, Schmidmaier G, and Wildemann B
- Subjects
- Bacteria, Cell Culture Techniques, Humans, In Vitro Techniques, War-Related Injuries microbiology, Anti-Bacterial Agents administration & dosage, Bone Wires, Osteomyelitis drug therapy, Prostheses and Implants, War-Related Injuries drug therapy
- Abstract
Purpose: Surgical procedures to prevent osteomyelitis after trauma can be supported by local application of antibiotics. This in-vitro study investigated the release and impact of antibiotics from implant coatings against bacteria associated with combat-related osteomyelitis., Methods: K-wires were coated with poly(D,L-lactide) and ciprofloxacin, gentamicin, colistin, daptomycin or cefoxitin in different concentrations. The release was quantified and antimicrobial activity tested for different gram-positive or gram-negative bacteria, alone and in combination. To exclude toxic effects, primary osteoblast-like cells were exposed to antibiotic coating concentrations., Results: All antibiotics alone and in combination showed an initial burst release with dose dependent antimicrobial activity and no negative effects on osteoblast-like cells, except for cefoxitin., Conclusions: Implant coatings can be customized with single or double antibiotic coatings to effectively fight different bacteria and also mixed infections in the treatment of a combat-acquired osteomyelitis. However, optimal drug load and degradation behaviour of individual antibiotics have to be considered.
- Published
- 2016
- Full Text
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26. Characterization of the Migration of Hop Volatiles into Different Crown Cork Liner Polymers and Can Coatings.
- Author
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Wietstock PC, Glattfelder R, Garbe LA, and Methner FJ
- Subjects
- Acyclic Monoterpenes, Alkenes, Beer analysis, Cyclohexane Monoterpenes, Cyclohexenes, Gas Chromatography-Mass Spectrometry, Limonene, Monocyclic Sesquiterpenes, Monoterpenes, Polycyclic Sesquiterpenes, Polyethylene, Sesquiterpenes, Humulus chemistry, Polymers chemistry, Terpenes analysis
- Abstract
Absorption of hop volatiles by crown cork liner polymers and can coatings was investigated in beer during storage. All hop volatiles measured were prone to migrate into the closures, and the absorption kinetics was demonstrated to fit Fick's second law of diffusion well for a plane sheet. The extent and rate of diffusion were significantly dissimilar and were greatly dependent upon the nature of the volatile. Diffusion coefficients ranged from 1.32 × 10(-5) cm(2)/day (limonene) to 0.26 × 10(-5) cm(2)/day (α-humulene). The maximum amounts absorbed into the material at equilibrium were in the following order: limonene > α-humulene > trans-caryophyllene > myrcene ≫ linalool > α-terpineol > geraniol. With the application of low-density polyethylene (LDPE) liners with oxygen-scavenging functionality, oxygen-barrier liners made up from high-density polyethylene (HDPE) or liner polymers from a different manufacturer had no significant effect on the composition of hop volatiles in beers after prolonged storage of 55 days; however, significantly higher amounts of myrcene and limonene were found in the oxygen-barrier-type crown cork, while all other closures behaved similarly. Can coatings were demonstrated to absorb hop volatiles in a similar pattern as crown corks but to a lesser extent. Consequently, significantly higher percentages of myrcene were found in the beers.
- Published
- 2016
- Full Text
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27. Estrogenicity of novel phase I and phase II metabolites of zearalenone and cis-zearalenone.
- Author
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Drzymala SS, Binder J, Brodehl A, Penkert M, Rosowski M, Garbe LA, and Koch M
- Subjects
- Cell Line, Tumor, Humans, Estrogens metabolism, Zearalenone metabolism
- Abstract
Zearalenone and its cis-isomer, cis-zearalenone, are nonsteroidal mycotoxins that elicit an estrogenic response upon binding to the estrogen receptor. This study compares the estrogenicity of eleven congeners including novel metabolites as 15-OH-zearalenone, zearalenone-14-sulfate, α-cis-zearalenol and β-cis-zearalenol using the E-Screen assay. Overall, a change in the configuration from trans to cis retains significant estrogenic activity. In contrast, alterations of the aromatic moiety including hydroxylation and sulfation showed a markedly decreased estrogenicity when compared to zearalenone., (Copyright © 2015 Elsevier Ltd. All rights reserved.)
- Published
- 2015
- Full Text
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28. Chip-based human liver-intestine and liver-skin co-cultures--A first step toward systemic repeated dose substance testing in vitro.
- Author
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Maschmeyer I, Hasenberg T, Jaenicke A, Lindner M, Lorenz AK, Zech J, Garbe LA, Sonntag F, Hayden P, Ayehunie S, Lauster R, Marx U, and Materne EM
- Subjects
- Cell Line, Tumor, Coculture Techniques methods, Endothelium, Vascular drug effects, Endothelium, Vascular metabolism, Female, Humans, Ileum drug effects, Liver drug effects, Skin drug effects, Troglitazone, Young Adult, Chromans administration & dosage, Ileum metabolism, Lab-On-A-Chip Devices, Liver metabolism, Skin metabolism, Thiazolidinediones administration & dosage
- Abstract
Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called "human-on-a-chip" concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms. The major technical hurdle toward success in this field is the life-like combination of human barrier organ models, such as intestine, lung or skin, with parenchymal organ equivalents, such as liver, at the smallest biologically acceptable scale. Here, we report on a reproducible homeostatic long-term co-culture of human liver equivalents with either a reconstructed human intestinal barrier model or a human skin biopsy applying a microphysiological system. We used a multi-organ chip (MOC) platform, which provides pulsatile fluid flow within physiological ranges at low media-to-tissue ratios. The MOC supports submerse cultivation of an intact intestinal barrier model and an air-liquid interface for the skin model during their co-culture with the liver equivalents respectively at (1)/100.000 the scale of their human counterparts in vivo. To increase the degree of organismal emulation, microfluidic channels of the liver-skin co-culture could be successfully covered with human endothelial cells, thus mimicking human vasculature, for the first time. Finally, exposure routes emulating oral and systemic administration in humans have been qualified by applying a repeated dose administration of a model substance - troglitazone - to the chip-based co-cultures., (Copyright © 2015. Published by Elsevier B.V.)
- Published
- 2015
- Full Text
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29. Automated solid-phase extraction coupled online with HPLC-FLD for the quantification of zearalenone in edible oil.
- Author
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Drzymala SS, Weiz S, Heinze J, Marten S, Prinz C, Zimathies A, Garbe LA, and Koch M
- Subjects
- Automation, Chromatography, High Pressure Liquid instrumentation, Chromatography, Liquid, Equipment Design, Hydrazines chemistry, Plant Oils chemistry, Reproducibility of Results, Solid Phase Extraction instrumentation, Tandem Mass Spectrometry methods, Chromatography, High Pressure Liquid methods, Food Analysis methods, Plant Oils analysis, Solid Phase Extraction methods, Zearalenone analysis
- Abstract
Established maximum levels for the mycotoxin zearalenone (ZEN) in edible oil require monitoring by reliable analytical methods. Therefore, an automated SPE-HPLC online system based on dynamic covalent hydrazine chemistry has been developed. The SPE step comprises a reversible hydrazone formation by ZEN and a hydrazine moiety covalently attached to a solid phase. Seven hydrazine materials with different properties regarding the resin backbone, pore size, particle size, specific surface area, and loading have been evaluated. As a result, a hydrazine-functionalized silica gel was chosen. The final automated online method was validated and applied to the analysis of three maize germ oil samples including a provisionally certified reference material. Important performance criteria for the recovery (70-120 %) and precision (RSDr <25 %) as set by the Commission Regulation EC 401/2006 were fulfilled: The mean recovery was 78 % and RSDr did not exceed 8 %. The results of the SPE-HPLC online method were further compared to results obtained by liquid-liquid extraction with stable isotope dilution analysis LC-MS/MS and found to be in good agreement. The developed SPE-HPLC online system with fluorescence detection allows a reliable, accurate, and sensitive quantification (limit of quantification, 30 μg/kg) of ZEN in edible oils while significantly reducing the workload. To our knowledge, this is the first report on an automated SPE-HPLC method based on a covalent SPE approach.
- Published
- 2015
- Full Text
- View/download PDF
30. In vitro characterization of self-assembled anterior cruciate ligament cell spheroids for ligament tissue engineering.
- Author
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Hoyer M, Meier C, Breier A, Hahner J, Heinrich G, Drechsel N, Meyer M, Rentsch C, Garbe LA, Ertel W, Lohan A, and Schulze-Tanzil G
- Subjects
- Animals, In Vitro Techniques, Rabbits, Anterior Cruciate Ligament cytology, Spheroids, Cellular, Tissue Engineering
- Abstract
Tissue engineering of an anterior cruciate ligament (ACL) implant with functional enthesis requires site-directed seeding of different cell types on the same scaffold. Therefore, we studied the suitability of self-assembled three-dimensional spheroids generated by lapine ACL ligament fibroblasts for directed scaffold colonization. The spheroids were characterized in vitro during 14 days in static and 7 days in dynamic culture. Size maintenance of self-assembled spheroids, the vitality, the morphology and the expression pattern of the cells were monitored. Additionally, we analyzed the total sulfated glycosaminoglycan, collagen contents and the expression of the ligament components type I collagen, decorin and tenascin C on protein and for COL1A1, DCN and TNMD on gene level in the spheroids. Subsequently, the cell colonization of polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) polymer scaffolds was assessed in response to a directed, spheroid-based seeding technique. ACL cells were able to self-assemble spheroids and survive over 14 days. The spheroids decreased in size but not in cellularity depending on the culture time and maintained or even increased their differentiation state. The area of P[LA-CL] scaffolds, colonized after 14 days by the cells of one spheroid, was in average 4.57 ± 2.3 mm(2). Scaffolds consisting of the polymer P[LA-CL] were more suitable for colonization by spheroids than PDS embroideries. We conclude that ACL cell spheroids are suitable as site-directed seeding strategy for scaffolds in ACL tissue engineering approaches and recommend the use of freshly assembled spheroids for scaffold colonization, due to their balanced proliferation and differentiation.
- Published
- 2015
- Full Text
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31. Polyclonal murine and rabbit antibodies for the bile acid isolithocholic acid.
- Author
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Gärtner S, Carvalho JJ, Emmerling F, Garbe LA, and Schneider RJ
- Subjects
- Animals, Bile Acids and Salts immunology, Enzyme-Linked Immunosorbent Assay methods, Immunoglobulin G immunology, Lithocholic Acid immunology, Mice, Rabbits, Bile Acids and Salts analysis, Immunoglobulin G chemistry, Lithocholic Acid analysis
- Abstract
Bile acids are relevant markers for clinical research. This study reports the production of antibodies for isolithocholic acid, the isomer of the extensively studied lithocholic acid. The IgG titer and affinity maturation were monitored during the immunizations of three mice and two rabbits. In both animal models, polyclonal antibodies with a high selectivity and affinity were produced. The development of a direct competitive ELISA with a test midpoint of 0.69 ± 0.05 μ g/L and a measurement range from 0.09-15 μg/L is reported. Additionally, the crystal structure of isolithocholic acid is described for the first time.
- Published
- 2015
- Full Text
- View/download PDF
32. Diffusion chamber system for testing of collagen-based cell migration barriers for separation of ligament enthesis zones in tissue-engineered ACL constructs.
- Author
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Hahner J, Hoyer M, Hillig S, Schulze-Tanzil G, Meyer M, Schröpfer M, Lohan A, Garbe LA, Heinrich G, and Breier A
- Subjects
- Animals, Anterior Cruciate Ligament metabolism, Anterior Cruciate Ligament surgery, Cattle, Cell Adhesion, Cell Migration Assays methods, Cell Movement, Cell Survival, Cells, Cultured, Connective Tissue Cells metabolism, Diffusion Chambers, Culture, Female, Humans, Materials Testing instrumentation, Microscopy, Electron, Scanning, Polyesters chemistry, Polypropylenes chemistry, Rabbits, Surface Properties, Anterior Cruciate Ligament cytology, Anterior Cruciate Ligament Reconstruction methods, Collagen chemistry, Connective Tissue Cells cytology, Materials Testing methods, Tissue Engineering, Tissue Scaffolds chemistry
- Abstract
A temporary barrier separating scaffold zones seeded with different cell types prevents faster growing cells from overgrowing co-cultured cells within the same construct. This barrier should allow sufficient nutrient diffusion through the scaffold. The aim of this study was to test the effect of two variants of collagen-based barriers on macromolecule diffusion, viability, and the spreading efficiency of primary ligament cells on embroidered scaffolds. Two collagen barriers, a thread consisting of a twisted film tape and a sponge, were integrated into embroidered poly(lactic-co-caprolactone) and polypropylene scaffolds, which had the dimension of lapine anterior cruciate ligaments (ACL). A diffusion chamber system was designed and established to monitor nutrient diffusion using fluorescein isothiocyanate-labeled dextran of different molecular weights (20, 40, 150, 500 kDa). Vitality of primary lapine ACL cells was tested at days 7 and 14 after seeding using fluorescein diacetate and ethidium bromide staining. Cell spreading on the scaffold surface was measured using histomorphometry. Nuclei staining of the cross-sectioned scaffolds revealed the penetration of ligament cells through both barrier types. The diffusion chamber was suitable to characterize the diffusivity of dextran molecules through embroidered scaffolds with or without integrated collagen barriers. The diffusion coefficients were generally significantly lower in scaffolds with barriers compared to those without barriers. No significant differences between diffusion coefficients of both barrier types were detected. Both barriers were cyto-compatible and prevented most of the ACL cells from crossing the barrier, whereby the collagen thread was easier to handle and allowed a higher rate of cell spreading.
- Published
- 2015
- Full Text
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33. In vitro phase I metabolism of cis-zearalenone.
- Author
-
Drzymala SS, Herrmann AJ, Maul R, Pfeifer D, Garbe LA, and Koch M
- Subjects
- Animals, Chromatography, High Pressure Liquid, Estrogens, Non-Steroidal chemistry, Humans, In Vitro Techniques, Metabolic Detoxication, Phase I, Molecular Structure, Rats, Species Specificity, Stereoisomerism, Tandem Mass Spectrometry, Zearalenone chemistry, Estrogens, Non-Steroidal metabolism, Microsomes, Liver metabolism, Zearalenone metabolism
- Abstract
The present study investigates the in vitro phase I metabolism of cis-zearalenone (cis-ZEN) in rat liver microsomes and human liver microsomes. cis-ZEN is an often ignored isomer of the trans-configured Fusarium mycotoxin zearalenone (trans-ZEN). Upon the influence of (UV-) light, trans-ZEN isomerizes to cis-ZEN. Therefore, cis-ZEN is also present in food and feed. The aim of our study was to evaluate the in vitro phase I metabolism of cis-ZEN in comparison to that of trans-ZEN. As a result, an extensive metabolization of cis-ZEN is observed for rat and human liver microsomes as analyzed by HPLC-MS/MS and high-resolution MS. Kinetic investigations based on the substrate depletion approach showed no significant difference in rate constants and half-lives for cis- and trans-ZEN in rat microsomes. In contrast, cis-ZEN was depleted about 1.4-fold faster than trans-ZEN in human microsomes. The metabolite pattern of cis-ZEN revealed a total of 10 phase I metabolites. Its reduction products, α- and β-cis-zearalenol (α- and β-cis-ZEL), were found as metabolites in both species, with α-cis-ZEL being a major metabolite in rat liver microsomes. Both compounds were identified by co-chromatography with synthesized authentic standards. A further major metabolite in rat microsomes was monohydroxylated cis-ZEN. In human microsomes, monohydroxylated cis-ZEN is the single dominant peak of the metabolite profile. Our study discloses three metabolic pathways for cis-ZEN: reduction of the keto-group, monohydroxylation, and a combination of both. Because these routes have been reported for trans-ZEN, we conclude that the phase I metabolism of cis-ZEN is essentially similar to that of its trans isomer. As trans-ZEN is prone to metabolic activation, leading to the formation of more estrogenic metabolites, the novel metabolites of cis-ZEN reported in this study, in particular α-cis-ZEL, might also show higher estrogenicity.
- Published
- 2014
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34. A bifunctional enzyme from Rhodococcus erythropolis exhibiting secondary alcohol dehydrogenase-catalase activities.
- Author
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Martinez-Rojas E, Kurt T, Schmidt U, Meyer V, and Garbe LA
- Subjects
- Alcohol Oxidoreductases chemistry, Alcohol Oxidoreductases isolation & purification, Catalase chemistry, Catalase isolation & purification, Cloning, Molecular, Coenzymes metabolism, Enzyme Stability, Escherichia coli genetics, Gene Expression, Lactones metabolism, Mass Spectrometry, NAD metabolism, Oxidation-Reduction, Rhodococcus genetics, Substrate Specificity, Temperature, Alcohol Oxidoreductases genetics, Alcohol Oxidoreductases metabolism, Catalase genetics, Catalase metabolism, Rhodococcus enzymology
- Abstract
Alcohol dehydrogenases have long been recognized as potential biocatalyst for production of chiral fine and bulk chemicals. They are relevant for industry in enantiospecific production of chiral compounds. In this study, we identified and purified a nicotinamide adenine dinucleotide (NAD)-dependent secondary alcohol dehydrogenase (SdcA) from Rhodococcus erythropolis oxidizing γ-lactols into γ-lactones. SdcA showed broad substrate specificity on γ-lactols; secondary aliphatic alcohols with 8 and 10 carbon atoms were also substrates and oxidized with (2S)-stereospecificity. The enzyme exhibited moderate stability with a half-life of 5 h at 40 °C and 20 days at 4 °C. Mass spectrometric identification revealed high sequence coverage of SdcA amino acid sequence to a highly conserved catalase from R. erythropolis. The corresponding encoding gene was isolated from genomic DNA and subsequently overexpressed in Escherichia coli BL21 DE3 cells. In addition, the recombinant SdcA was purified and characterized in order to confirm that the secondary alcohol dehydrogenase and catalase activity correspond to the same enzyme.
- Published
- 2014
- Full Text
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35. Embroidered polymer-collagen hybrid scaffold variants for ligament tissue engineering.
- Author
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Hoyer M, Drechsel N, Meyer M, Meier C, Hinüber C, Breier A, Hahner J, Heinrich G, Rentsch C, Garbe LA, Ertel W, Schulze-Tanzil G, and Lohan A
- Subjects
- Animals, Cattle, Microscopy, Electron, Scanning, Anterior Cruciate Ligament, Collagen, Polymers, Tissue Engineering, Tissue Scaffolds
- Abstract
Embroidery techniques and patterns used for scaffold production allow the adaption of biomechanical scaffold properties. The integration of collagen into embroidered polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) scaffolds could stimulate neo-tissue formation by anterior cruciate ligament (ACL) cells. Therefore, the aim of this study was to test embroidered P(LA-CL) and PDS scaffolds as hybrid scaffolds in combination with collagen hydrogel, sponge or foam for ligament tissue engineering. ACL cells were cultured on embroidered P(LA-CL) and PDS scaffolds without or with collagen supplementation. Cell adherence, vitality, morphology and ECM synthesis were analyzed. Irrespective of thread size, ACL cells seeded on P(LA-CL) scaffolds without collagen adhered and spread over the threads, whereas the cells formed clusters on PDS and larger areas remained cell-free. Using the collagen hydrogel, the scaffold colonization was limited by the gel instability. The collagen sponge layers integrated into the scaffolds were hardly penetrated by the cells. Collagen foams increased scaffold colonization in P(LA-CL) but did not facilitate direct cell-thread contacts in the PDS scaffolds. The results suggest embroidered P(LA-CL) scaffolds as a more promising basis for tissue engineering an ACL substitute than PDS due to superior cell attachment. Supplementation with a collagen foam presents a promising functionalization strategy., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
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36. Performance evaluation of kits for bisulfite-conversion of DNA from tissues, cell lines, FFPE tissues, aspirates, lavages, effusions, plasma, serum, and urine.
- Author
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Holmes EE, Jung M, Meller S, Leisse A, Sailer V, Zech J, Mengdehl M, Garbe LA, Uhl B, Kristiansen G, and Dietrich D
- Subjects
- Humans, Sulfites, Body Fluids chemistry, Cell Line chemistry, DNA analysis, DNA Methylation, Reagent Kits, Diagnostic standards
- Abstract
DNA methylation analyses usually require a preceding bisulfite conversion of the DNA. The choice of an appropriate kit for a specific application should be based on the specific performance requirements with regard to the respective sample material. In this study, the performance of nine kits was evaluated: EpiTect Fast FFPE Bisulfite Kit, EpiTect Bisulfite Kit, EpiTect Fast DNA Bisulfite Kit (Qiagen), EZ DNA Methylation-Gold Kit, EZ DNA Methylation-Direct Kit, EZ DNA Methylation-Lightning Kit (Zymo Research), innuCONVERT Bisulfite All-In-One Kit, innuCONVERT Bisulfite Basic Kit, innuCONVERT Bisulfite Body Fluids Kit (Analytik Jena). The kit performance was compared with regard to DNA yield, DNA degradation, DNA purity, conversion efficiency, stability and handling using qPCR, UV, clone sequencing, HPLC, and agarose gel electrophoresis. All kits yielded highly pure DNA suitable for PCR analyses without PCR inhibition. Significantly higher yields were obtained when using the EZ DNA Methylation-Gold Kit and the innuCONVERT Bisulfite kits. Conversion efficiency ranged from 98.7% (EpiTect Bisulfite Kit) to 99.9% (EZ DNA Methylation-Direct Kit). The inappropriate conversion of methylated cytosines to thymines varied between 0.9% (innuCONVERT Bisulfite kits) and 2.7% (EZ DNA Methylation-Direct Kit). Time-to-result ranged from 131 min (innuCONVERT kits) to 402 min (EpiTect Bisulfite Kit). Hands-on-time was between 66 min (EZ DNA Methylation-Lightning Kit) and 104 min (EpiTect Fast FFPE and Fast DNA Bisulfite kits). Highest yields from formalin-fixed and paraffin-embedded (FFPE) tissue sections without prior extraction were obtained using the innuCONVERT Bisulfite All-In-One Kit while the EZ DNA Methylation-Direct Kit yielded DNA with only low PCR-amplifiability. The innuCONVERT Bisulfite All-In-One Kit exhibited the highest versatility regarding different input sample materials (extracted DNA, tissue, FFPE tissue, cell lines, urine sediment, and cellular fractions of bronchial aspirates, pleural effusions, ascites). The innuCONVERT Bisulfite Body Fluids Kit allowed for the analysis of 3 ml plasma, serum, ascites, pleural effusions and urine.
- Published
- 2014
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37. Fluorescence polarization immunoassays for the quantification of caffeine in beverages.
- Author
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Oberleitner L, Grandke J, Mallwitz F, Resch-Genger U, Garbe LA, and Schneider RJ
- Subjects
- Cosmetics analysis, Beverages analysis, Caffeine analysis, Fluorescence Polarization Immunoassay methods
- Abstract
Homogeneous fluorescence polarization immunoassays (FPIAs) were developed and compared for the determination of caffeine in beverages and cosmetics. FPIAs were performed in cuvettes in a spectrometer for kinetic FP measurements as well as in microtiter plates (MTPs) on a multimode reader. Both FPIAs showed measurement ranges in the μg/L range and were performed within 2 and 20 min, respectively. For the application on real samples, high coefficients of variations (CVs) were observed for the performance in MTPs; the CVs for FPIAs in cuvettes were below 4%. The correlations between this method and reference methods were satisfying. The sensitivity was sufficient for all tested samples including decaffeinated coffee without preconcentration steps. The FPIA in cuvettes allows a fast, precise, and automated quantitative analysis of caffeine in consumer products, whereas FPIAs in MTPs are suitable for semiquantitative high-throughput screenings. Moreover, specific quality criteria for heterogeneous assays were applied to homogeneous immunoassays.
- Published
- 2014
- Full Text
- View/download PDF
38. Quality assurance in immunoassay performance--comparison of different enzyme immunoassays for the determination of caffeine in consumer products.
- Author
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Grandke J, Oberleitner L, Resch-Genger U, Garbe LA, and Schneider RJ
- Subjects
- Animals, Antibodies, Monoclonal analysis, Benzidines metabolism, Chromatography, Liquid, Fluorescent Dyes metabolism, Hymecromone analogs & derivatives, Hymecromone metabolism, Nitrophenols metabolism, Organophosphorus Compounds metabolism, Phenylpropionates metabolism, Sensitivity and Specificity, Tandem Mass Spectrometry, Alkaline Phosphatase metabolism, Beverages analysis, Caffeine analysis, Cosmetics analysis, Horseradish Peroxidase metabolism, Immunoenzyme Techniques methods
- Abstract
Enzyme immunoassays with optical detection are amongst the most widely used bioanalytical tools. We defined seven parameters for the quality assessment of immunoassays that were addressed in a systematic study of direct and indirect immunoassays, using the enzymes horseradish peroxidase (HRP) and alkaline phosphatase (AP), the chromogenic substrates 3,3',5,5'-tetramethylbenzidine (TMB) and para-nitrophenyl phosphate, and the fluorescent substrates 3-(4-hydroxyphenyl)propionic acid and 4-methylumbelliferyl phosphate. The same monoclonal antibody against caffeine was used throughout the study. The four quality parameters regarding the standard curve were the test midpoint (sensitivity), the measurement range, the relative dynamic range of the signal, and the goodness of fit of the adjusted four-parameter logistic function. All HRP immunoassays showed a higher sensitivity compared to the AP assays. On the basis of all four criteria, it was established that the direct assay format is superior to the indirect format, the immunoassay using HRP TMB fulfilling all requirements best. In a second step, caffeine concentrations in 24 beverage and cosmetics samples were determined and three more quality parameters were assessed with this application. The direct HRP TMB assay showed one of the best intra- and inter-plate precisions and the best accuracy, defined by the correlation of results with those from the chosen reference method liquid chromatography tandem mass spectrometry (LC-MS/MS). Considering all criteria, HRP TMB seems to be the enzyme substrate system of choice preferably used in the direct assay format.
- Published
- 2013
- Full Text
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39. Quantity matters: male sex pheromone signals mate quality in the parasitic wasp Nasonia vitripennis.
- Author
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Ruther J, Matschke M, Garbe LA, and Steiner S
- Subjects
- Animals, Cues, Female, Fertility, Male, Sex Attractants metabolism, Sex Attractants pharmacology, Sex Ratio, Smell, Stimulation, Chemical, Wasps drug effects, Wasps metabolism, Mating Preference, Animal drug effects, Sex Attractants physiology, Wasps physiology
- Abstract
Sexual selection theory asserts that females are well adapted to sense signals indicating the quality of potential mates. One crucial male quality parameter is functional fertility (i.e. the success of ejaculates in fertilizing eggs). The phenotype-linked fertility hypothesis (PLFH) predicts that functional fertility of males is reflected by phenotypic traits that influence female mate choice. Here, we show for Nasonia vitripennis, a parasitic wasp with haplodiploid sex determination and female-biased sex ratios, that females use olfactory cues to discriminate against sperm-limited males. We found sperm limitation in newly emerged and multiply mated males (seven or more previous matings) as indicated by a higher proportion of sons in the offspring fathered by these males. Sperm limitation correlated with clearly reduced pheromone titres. In behavioural bioassays, females oriented towards higher doses of the synthetic pheromone and were attracted more often to scent marks of males with a full sperm load than to those of sperm-limited males. Our data support the PLFH and suggest that N. vitripennis females are able to decrease the risk of getting constrained to produce suboptimal offspring sex ratios by orienting towards gradients of the male sex pheromone.
- Published
- 2009
- Full Text
- View/download PDF
40. An epoxide hydrolase involved in the biosynthesis of an insect sex attractant and its use to localize the production site.
- Author
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Abdel-Latief M, Garbe LA, Koch M, and Ruther J
- Subjects
- Abdomen, Animals, Chromatography, High Pressure Liquid, Epoxide Hydrolases genetics, Female, Lactones analysis, Lactones chemistry, Male, Mass Spectrometry, Molecular Sequence Data, Organ Specificity, Pheromones analysis, Pheromones chemistry, Phylogeny, RNA Interference, Sex Attractants analysis, Sex Attractants chemistry, Wasps anatomy & histology, Epoxide Hydrolases metabolism, Pheromones biosynthesis, Sex Attractants biosynthesis, Wasps enzymology
- Abstract
Epoxide hydrolases (EHs) are enzymes occurring in virtually any living organism. They catalyze the hydrolysis of epoxide containing lipids and are involved in crucial mechanisms, such as the detoxification of xenobiotics or the regulation of inflammation and blood pressure. Here, we describe a function of a putative EH gene in the biosynthesis of a sex attractant in the jewel wasp Nasonia vitripennis and use this gene to localize the site of pheromone production. Males of this parasitic wasp release a mixture of (4R,5R)-( threo-) and (4R,5S)-( erythro-)5-hydroxy-4-decanolide (HDL) to attract virgin females. Using a stable isotope labeled precursor, we demonstrated that vernolic acid ( erythro-12,13-epoxy-octadec-9Z-enoic acid) is converted by N. vitripennis males to threo-HDL. This suggested the involvement of an EH in hydrolyzing the fatty acid epoxide under inversion of the stereochemistry into the respective diol, which might be further processed by chain shortening and lactonization to HDL. We cloned a putative N. vitripennis EH gene (Nasvi-EH1) encoding 470 amino acids and localized its transcripts in the male rectal papillae by in situ RT-PCR. Chemical analyses and histological studies confirmed that males synthesize the sex attractant in the rectal vesicle and release it via the anal orifice. Involvement of Nasvi-EH1 in HDL biosynthesis was established by RNAi-mediated gene silencing. Injection of Nasvi-EH1 dsRNA into male abdomens inhibited pheromone biosynthesis by 55% and suppressed the targeted gene transcripts in the rectal vesicle by 95%.
- Published
- 2008
- Full Text
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41. The peptide-catalyzed Maillard reaction: characterization of 13C reductones.
- Author
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Garbe LA, Würtz A, Piechotta CT, and Tressl R
- Subjects
- Amines chemistry, Carbon Isotopes, Mass Spectrometry, Oligopeptides chemical synthesis, Oligopeptides chemistry, Organic Chemicals chemistry, Oxidation-Reduction, gamma-Aminobutyric Acid chemistry, Maillard Reaction, Peptides chemistry
- Abstract
The reaction pathways of amino acids and reducing sugars are now fully understood. The focus in the last few years, however, has turned to the reaction of peptides and proteins with reducing sugars. We have investigated the reaction of gamma-aminobutanoic acid, the heptapeptide Nalpha-Acetyl-Lys-Lys-beta-Ala-Lys-beta-Ala-Lys-Gly, and the model protein beta-casein in Maillard reactions with 1-13C arabinose. Characterization of 13C-labeled acetic acid and norfuraneol by gas chromatography-mass spectrometry and nuclear magnetic resonance revealed new formation pathways. The results demonstrate significant differences in the labeling pattern of the products depending on the amine used, indicating different formation pathways of acetic acid and norfuraneol.
- Published
- 2008
- Full Text
- View/download PDF
42. 4-methylquinazoline is a minor component of the male sex pheromone in Nasonia vitripennis.
- Author
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Ruther J, Steiner S, and Garbe LA
- Subjects
- Animals, Female, Lactones analysis, Male, Odorants, Wasps drug effects, Lactones pharmacology, Quinazolines analysis, Quinazolines pharmacology, Sex Attractants analysis, Sex Attractants pharmacology, Sexual Behavior, Animal drug effects, Wasps physiology
- Abstract
We identified 4-methylquinazoline (4-MeQ) as a minor component of the male sex pheromone of the parasitoid Nasonia vitripennis. Like the major components (4R,5R)- and (4R,5S)-5-hydroxy-4-decanolide (HDL), 4-MeQ is synthesized in the abdomen of males. At doses of 6 or 1 ng, 4-MeQ synergized the response of virgin females to the HDL-diastereomers in a still-air olfactometer, but was not attractive as a single component. 4-MeQ is also responsible for the characteristic medicinal odor of N. vitripennis males.
- Published
- 2008
- Full Text
- View/download PDF
43. A male sex pheromone in a parasitic wasp and control of the behavioral response by the female's mating status.
- Author
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Ruther J, Stahl LM, Steiner S, Garbe LA, and Tolasch T
- Subjects
- Animals, Female, Male, Oviposition physiology, Parasites physiology, Sex Attractants physiology, Sexual Behavior, Animal physiology, Wasps physiology
- Abstract
Male insects may increase their chance of successful reproduction by releasing pheromones that attract females or elicit sexual acceptance. In parasitic wasps, male pheromones have been suggested for a few species but no chemicals have been identified so far. Here we report the first identification of a male sex pheromone in parasitic Hymenoptera. In abdomens of male jewel wasps, Nasonia vitripennis Walker, we found a mixture of (4R,5R)- and (4R,5S)-5-hydroxy-4-decanolide (HDL), which was released intermittently and attracted virgin females, but no males, in an olfactometer bioassay. However, only a few minutes after copulation mated females avoided the male-derived pheromone. Neither preference nor avoidance was shown by mated females after 24 h and even after they had been allowed to oviposit for 6 days. Nasonia vitripennis females normally mate only once. Thus, their variable response to the sex attractant depending on the mating status makes sense from an evolutionary perspective. Firstly, it increases the chance of virgins to be inseminated. Secondly, by terminating the response or even avoiding the male pheromone, mated females decrease the probability of encountering males and being disturbed by their courtship activities when searching for new oviposition sites.
- Published
- 2007
- Full Text
- View/download PDF
44. Dual positional and stereospecificity of lipoxygenase isoenzymes from germinating barley (green malt): biotransformation of free and esterified linoleic acid.
- Author
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Garbe LA, Barbosa de Almeida R, Nagel R, Wackerbauer K, and Tressl R
- Subjects
- Esterification, Isoelectric Focusing, Isoenzymes isolation & purification, Linoleic Acids metabolism, Lipid Peroxides metabolism, Lipoxygenase isolation & purification, Seeds growth & development, Stereoisomerism, Substrate Specificity, Germination, Hordeum enzymology, Isoenzymes metabolism, Linoleic Acid metabolism, Lipoxygenase metabolism, Seeds enzymology
- Abstract
The lipoxygenase isoenzymes LOX1 and LOX2 from green malt were separated by isoelectric focusing, and their catalytic properties regarding complex lipids as substrates were characterized. The regio- and stereoisomers of hydroperoxy octadecadienoates (HPODE) resulting from LOX1 and LOX2 enzymatic transformations of linoleic acid, methyl linoleate, linoleic acid glycerol esters monolinolein, dilinolein, and trilinolein, and 1-palmitoyl-2-linoleoyl-glycero-3-phosphocholine (PamLinGroPCho) were determined. In addition, biotransformations of polar and nonpolar lipids extracted from malt were performed with LOX1 and LOX2. The results show that LOX2 catalyzes the oxidation of esterified fatty acids at a higher rate and is more regioselective than LOX1. The dual position specificity of LOX2 (9-HPODE:13-HPODE) with trilinolein as the substrate (6:94) was higher than the resultant ratio (13:87) when free linoleic acid was transformed. A high (S)-enantiomeric excess of 13-HPODE was analyzed with all esterified substrates confirming the formation of 13-HPODE through the LOX2 enzyme; however, 9-HPODE detected after LOX2 biotransformations showed (R)-enantiomeric excesses. PamLinGroPCho was oxygenated by LOX1 with the highest regio- and stereoselectivities among the applied substrates.
- Published
- 2006
- Full Text
- View/download PDF
45. Preferential attack of the (S)-configured ether-linked carbons in bis-(1-chloro-2-propyl) ether by Rhodococcus sp. strain DTB.
- Author
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Garbe LA, Moreno-Horn M, Tressl R, and Görisch H
- Subjects
- Biodegradation, Environmental, Carbon metabolism, Dichlorodiphenyl Dichloroethylene chemistry, Rhodococcus growth & development, Stereoisomerism, Dichlorodiphenyl Dichloroethylene metabolism, Rhodococcus metabolism
- Abstract
Rhodococcus sp. strain DTB (DSM 44534) was grown on a mixture of (R,R)-, (S,S)- and meso-bis-(1-chloro-2-propyl) ether (BCPE) as the sole source of carbon and energy. During BCPE degradation 1'-chloro-2'-propyl-3-chloro-2-prop-1-enyl-ether (DVE), 1-chloro-2-propanol and chloroacetone intermediates were formed. The BCPE or DVE stereoisomers were metabolized in consecutive order via scission of the ether bond, with discrimination against the (R) configuration. Resting cell suspensions of Rhodococcus pregrown on BCPE showed a preferential attack of the (S)-configured ether-linked carbons, resulting in an enantioselective enrichment of (R,R)-BCPE. Microbial discrimination of BCPE or DVE isomers and chemical conversion of the intermediates to 1-chloro-2-propanol allowed the identification of the configuration of all BCPE isomers and the DVE enantiomers. Elucidation of the absolute configuration of the 1-chloro-2-propanol isomers was achieved by enantioselective chemical synthesis.
- Published
- 2006
- Full Text
- View/download PDF
46. Transient accumulation of gamma-butyrolactone during degradation of bis(4-chloro-n-butyl) ether by diethylether-grown Rhodococcus sp. strain DTB.
- Author
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Moreno-Horn M, Garbe LA, Tressl R, and Görisch H
- Subjects
- 4-Butyrolactone analysis, Biodegradation, Environmental drug effects, Ether chemistry, Rhodococcus growth & development, 4-Butyrolactone metabolism, Ether metabolism, Ethers metabolism, Rhodococcus metabolism
- Abstract
Rhodococcus sp. strain DTB (DSM 44534) grows aerobically on diethylether as sole source of carbon and energy. Dense cell suspension experiments showed that the induced ether-cleaving enzyme system attacks a broad range of ethers like tetrahydrofuran, phenetole and chlorinated alkylethers including Calpha-substituted alkylethers. Identification of metabolites revealed that degradation of the ethers started by an initial attack of the ether bond. Diethylether-grown cells degraded bis(4-chloro-n-butyl) ether via an initial ether scission followed by the transient accumulation of gamma-butyrolactone as intermediate at nearly stoichiometric concentrations.
- Published
- 2005
- Full Text
- View/download PDF
47. Characterization and quantification of free and esterified 9- and 13-hydroxyoctadecadienoic acids (HODE) in barley, germinating barley, and finished malt.
- Author
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Hübke H, Garbe LA, and Tressl R
- Subjects
- Chromatography, High Pressure Liquid, Esterification, Gas Chromatography-Mass Spectrometry, Linoleic Acids chemistry, Linoleic Acids, Conjugated chemistry, Stereoisomerism, Edible Grain chemistry, Germination, Hordeum chemistry, Linoleic Acids analysis, Linoleic Acids, Conjugated analysis, Seeds chemistry
- Abstract
The analysis of (R)-9- and (S)-9-hydroxy-10E,12Z-octadecadienoic acid as well as (R)-13- and (S)-13-hydroxy-9Z,11E-octadecadienoic acid (HODE) as free acids, esterified in triacylglycerols (storage lipids), and esterified in polar lipids (phospholipids, glycolipids, etc.) in barley, germinating barley, and finished malt was performed using [13-(18)O(1)]-(S)-13-HODE isotope dilution assays with GC-MS and straight- and chiral-phase HPLC. 9- and 13- HODE occur approximately racemically in barley, indicating an autoxidation. The enantiomeric excesses increase to 78% S for free 9-HODE and to 58% S for free 13-HODE in germinating barley as a result of lipoxygenase-2 (LOX-2) catalysis, but free HODEs are at low concentration. More than 90% of HODEs in barley and malt are esterified. In the storage lipids of green malt 53 mg/kg 9-HODE and 147 mg/kg 13-HODE were detected. This ratio of 30:70 reflects the regioselectivity of the LOX-2 enzyme in malt. In the polar lipids 45 mg/kg 9-HODE and 44 mg/kg 13-HODE were characterized. The latter indicate a hitherto unknown 9-lipoxygenase activity with polar lipids as substrates. During kilning the contents of most HODEs decreased significantly due to chemical and enzymatic degradation, whereas polar-esterified (R)-13-HODE increased (43%) in the finished malt.
- Published
- 2005
- Full Text
- View/download PDF
48. Microbial desaturation of bis(1-chloro-2-propyl) ether into a dichloro vinyl ether.
- Author
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Garbe LA, Moreno-Horn M, Rewicki D, Tressl R, and Görisch H
- Subjects
- Biotransformation, Enzymes metabolism, Mass Spectrometry, Ethers metabolism, Rhodococcus metabolism, Vinyl Compounds metabolism
- Published
- 2004
- Full Text
- View/download PDF
49. Enzymatic Baeyer-Villiger oxidation as the key step in decano-4-lactone and decano-5-lactone degradation by Sporobolomyces odorus.
- Author
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Garbe LA and Tressl R
- Subjects
- Decanoates chemistry, Lactones chemistry, Oxidation-Reduction, Basidiomycota enzymology, Decanoates metabolism, Lactones metabolism
- Abstract
The biosyntheses of aroma active gamma- and delta-lactones have been previously characterized in yeasts and plants by incubation of labeled fatty acid derivatives. The lactones were considered as end products. Liquid cultures of the lactone-producing yeast Sporobolomyces odorus were used to investigate catabolic pathways of the lactones by incubation of ethyl (+/-)-5-hydroxy(1-(13)C1)decanoate ((13C)-1b) and methyl (+/-)-4-hydroxy(1-(13)C1)decanoate ((13C)-7a). Aliquots of the culture broth were analyzed with GC/MS after CH2N2 derivatization. S. odorus degraded (13C)-1b to 5-oxo(1-(13)C1)decanoic acid ((13C)-2c) and, subsequently, to pentyl (1-(13)C1)pentanedioate ((13C)-3c) and 3-[(1-(13)C1)carboxypropyl] hexanoate ((13C)-4c) by a Baeyer-Villiger-type oxidation (BVO). In addition, the oxidation of (13C)-7a to 4-oxo(1-(13)C1)decanoic acid ((13C)-8c) and a BVO of (13C)-8c to hexyl (1-(13)C1)butanedioate ((13C)-9c) is reported. So far, BVO has been observed in bacteria and some fungi; the data presented indicate a BVO catalyzed by the yeast S. odorus in the course of endogenous lactone metabolism.
- Published
- 2004
- Full Text
- View/download PDF
50. Biodegradation of bis(1-chloro-2-propyl) ether via initial ether scission and subsequent dehalogenation by Rhodococcus sp. strain DTB.
- Author
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Moreno Horn M, Garbe LA, Tressl R, Adrian L, and Görisch H
- Subjects
- Biodegradation, Environmental drug effects, Ether analysis, Ethers analysis, Industrial Waste analysis, Methimazole pharmacology, Mixed Function Oxygenases antagonists & inhibitors, Rhodococcus growth & development, Time Factors, Environmental Pollutants metabolism, Ether metabolism, Ethers metabolism, Rhodococcus metabolism
- Abstract
Rhodococcus sp. strain DTB (DSM 44534) grows on bis(1-chloro-2-propyl) ether (DDE) as sole source of carbon and energy. The non-chlorinated diisopropyl ether and bis(1-hydroxy-2-propyl) ether, however, did not serve as substrates. In ether degradation experiments with dense cell suspensions, 1-chloro-2-propanol and chloroacetone were formed, which indicated that scission of the ether bond is the first step while dehalogenation of the chlorinated C(3)-compounds occurs at a later stage of the degradation pathway. Inhibition of ether scission by methimazole suggested that the first step in degradation is catalyzed by a flavin-dependent enzyme activity. The non-chlorinated compounds 1,2-propanediol, hydroxyacetone, lactate, pyruvate, 1-propanol, propanal, and propionate also supported growth, which suggested that the intermediates 1,2-propanediol and hydroxyacetone are converted to pyruvate or to propionate, which can be channeled into the citric acid cycle by a number of routes. Total release of chloride and growth-yield experiments with DDE and non-chlorinated C(3)-compounds suggested complete biodegradation of the chlorinated ether.
- Published
- 2003
- Full Text
- View/download PDF
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