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Established in vitro assays for regulatory testing of skin sensitisation partly suffer from only moderate sensitivity, specificity, and predictivity when testing specific groups of chemicals. This may be due to limited biomarker response in vitro in cell types that interact as crucial players of in vivo skin sensitisation pathogenesis. Here, we propose a molecular approach to overcome this limitation. In our model, we apply genome editing and blocking of immunoregulatory molecules to increase the range of biomarker modulation by sensitising chemicals. To this end, aryl hydrocarbon receptor (AhR) knockout was done by CRISPR/Cas9 technology in THP-1 cells and combined with Programmed Cell Death-Ligand (PD-L)1 blockade. AhR-knockout THP-1 in coculture with HaCaT keratinocytes showed increased CD54 expression compared to wild type cells after stimulation with 10 µmol/L dinitrochlorobenzene (DNCB) that was further enhanced by anti-PD-L1. After stimulation of AhR-knockout THP-1 with 200 µmol/L mercaptobenzothiazol or 10 µmol/L DNCB, cocultivated Jurkat T cells significantly increased expression of T cell receptor-associated CD3. No such increase was detected after prior treatment of THP-1 with 150 µmol/L of irritant sodium lauryl sulphate. Additionally, higher levels of inflammatory cytokines MIP-3α, MIP-1β, TNF-α, and IL-8 were found in supernatants of enhanced loose-fit co-culture based sensitisation assay (eLCSA) after substance treatment. Hence, eLCSA allowed to discriminate between sensitisers and non-sensitisers. Thus, inhibition of immunoinhibitory pathway signalling by combining AhR knockout and PD-L1 antibody blockage into an assay involving main acting cell types in skin sensitisation may increase sensitivity and specificity of such assays and allow potency derivation.

ZusammenfassungDie Tuberkulose ist in Deutschland eine seltene, überwiegend gut behandelbare Erkrankung. Weltweit ist sie eine der häufigsten Infektionserkrankungen mit ca. 10 Millionen Neuerkrankungen/Jahr. Auch bei einer niedrigen Inzidenz in Deutschland bleibt Tuberkulose insbesondere aufgrund der internationalen Entwicklungen und Migrationsbewegungen eine wichtige Differenzialdiagnose. In Deutschland besteht, aufgrund der niedrigen Prävalenz der Erkrankung und der damit verbundenen abnehmenden klinischen Erfahrung, ein Informationsbedarf zu allen Aspekten der Tuberkulose und ihrer Kontrolle. Diese Leitlinie umfasst die mikrobiologische Diagnostik, die Grundprinzipien der Standardtherapie, die Behandlung verschiedener Organmanifestationen, den Umgang mit typischen unerwünschten Arzneimittelwirkungen, die Besonderheiten in der Diagnostik und Therapie resistenter Tuberkulose sowie die Behandlung bei TB-HIV-Koinfektion. Sie geht darüber hinaus auf Versorgungsaspekte und gesetzliche Regelungen wie auch auf die Diagnosestellung und präventive Therapie einer latenten tuberkulösen Infektion ein. Es wird ausgeführt, wann es der Behandlung durch spezialisierte Zentren bedarf.Die Aktualisierung der S2k-Leitlinie „Tuberkulose im Erwachsenenalter“ soll allen in der Tuberkuloseversorgung Tätigen als Richtschnur für die Prävention, die Diagnose und die Therapie der Tuberkulose dienen und helfen, den heutigen Herausforderungen im Umgang mit Tuberkulose in Deutschland gewachsen zu sein.

In Germany tuberculosis is a rare disease and usually well treatable. Worldwide it is one of the most common infectious diseases with approximately 10 million new cases every year. Even with low incidences in Germany, tuberculosis is an important differential diagnosis especially due to international developments and migration movements. With a decreasing experience there's a continuous demand on accurate and up-to-date information. This guideline covers all aspects of microbiological diagnostics, basic principles of standard therapy, treatment of extrapulmonary tuberculosis, management of side effects, special features of diagnosis and treatment of resistant tuberculosis, and treatment in TB-HIV coinfection. Also, it explains when treatment in specialized centers is required, aspects of care and legal regulations and the diagnosis and preventive therapy of latent tuberculosis infection. The update of the S2k guideline "Tuberculosis in Adults" is intended to serve as a guideline for prevention, diagnosis, and treatment of tuberculosis for all those involved in tuberculosis care and to help meet the current challenges in dealing with tuberculosis in Germany.Die Tuberkulose ist in Deutschland eine seltene, überwiegend gut behandelbare Erkrankung. Weltweit ist sie eine der häufigsten Infektionserkrankungen mit ca. 10 Millionen Neuerkrankungen/Jahr. Auch bei einer niedrigen Inzidenz in Deutschland bleibt Tuberkulose insbesondere aufgrund der internationalen Entwicklungen und Migrationsbewegungen eine wichtige Differenzialdiagnose. In Deutschland besteht, aufgrund der niedrigen Prävalenz der Erkrankung und der damit verbundenen abnehmenden klinischen Erfahrung, ein Informationsbedarf zu allen Aspekten der Tuberkulose und ihrer Kontrolle. Diese Leitlinie umfasst die mikrobiologische Diagnostik, die Grundprinzipien der Standardtherapie, die Behandlung verschiedener Organmanifestationen, den Umgang mit typischen unerwünschten Arzneimittelwirkungen, die Besonderheiten in der Diagnostik und Therapie resistenter Tuberkulose sowie die Behandlung bei TB-HIV-Koinfektion. Sie geht darüber hinaus auf Versorgungsaspekte und gesetzliche Regelungen wie auch auf die Diagnosestellung und präventive Therapie einer latenten tuberkulösen Infektion ein. Es wird ausgeführt, wann es der Behandlung durch spezialisierte Zentren bedarf.Die Aktualisierung der S2k-Leitlinie „Tuberkulose im Erwachsenenalter“ soll allen in der Tuberkuloseversorgung Tätigen als Richtschnur für die Prävention, die Diagnose und die Therapie der Tuberkulose dienen und helfen, den heutigen Herausforderungen im Umgang mit Tuberkulose in Deutschland gewachsen zu sein.

Skin sensitisation involves activation of dendritic cells which activate T cells and induce their clonal expansion. While the first step is covered by OECD-validated new approach methodologies, the latter is not until now. This may be due to a weak dendritic cell activation in vitro that is not strong enough to mediate activation of T cells. Here, we suppressed two inhibitory pathways to overcome this problem. We blocked the Programmed Cell Death (PD) pathway with anti-PD-L1 antibody and knocked out aryl hydrocarbon receptor (AhR) in THP-1 cells by CRISPR/Cas9 technology. Thereby, we reduced AhR

This is the fourth chapter of the guideline "Calculated initial parenteral treatment of bacterial infections in adults - update 2018" in the 2Dies ist das vierte Kapitel der von der Paul-Ehrlich-Gesellschaft für Chemotherapie e.V. (PEG) herausgegebenen S2k Leitlinie „Kalkulierte parenterale Initialtherapie bakterieller Erkrankungen bei Erwachsenen – Update 2018“ in der 2. aktualisierten Fassung.Die Sicherheit und Verträglichkeit von antimikrobiellen Wirkstoffen werden in diesem Kapitel diskutiert. Toxische, allergische und biologische Wirkungen können auf der Basis ihrer Pathogenese unterschieden werden. Die Frage nach Unterschieden in der Verträglichkeit verschiedener Antibiotika ist von besonderer Bedeutung. Sie kann jedoch häufig nicht mit der gewünschten Genauigkeit beantwortet werden, weil die verfügbaren Daten limitiert sind. Für eine Bewertung seltener Nebenwirkungen müssen die Ergebnisse aus der Überwachung nach der Zulassung herangezogen werden.

BACKGROUND: With the worldwide spread of SARS-CoV-2 infection, it is becoming increasingly urgent to develop a vaccine to prevent COVID-19, as well as effective drugs to treat it. METHODS: This article is based on a selective literature search in PubMed and ClinicalTrials.gov, followed by an assessment of the ongoing clinical trials that were revealed by the search. RESULTS: A number of substances have been found to prevent the reproduction of SARS-CoV-2 in vitro. These include virustatic agents that have already been approved for the treatment of other types of viral infection, as well as drugs that are currently used for entirely different purposes. High in vitro activity has been found for the nucleotide analogue remdesivir, for the antimalarial drug chloroquine, and for nitazoxanide, a drug used to treat protozoan infections. Because the virus enters human cells by way of the membrane-associated angiotensin converting enzyme 2 (ACE2), keeping the virus from docking to this receptor is a conceivable treatment approach. Transmembrane protease serine 2 (TMPRSS2) plays a role in the fusion of the virus with cells; inhibitors of this enzyme are known as well. The potential therapeutic efficacy and tolerability of these and other active substances remain to be investigated in clinical trials. At present, more than 80 trials on COVID-10 have already been registered with Clinical- Trials.gov. Some initial findings should already be available in late April 2020. CONCLUSION: Clinical trials are now indispensable in order to determine the true clinical benefits and risks of the substances that have been found to be active against SARSCoV- 2 in vitro. There is not yet any recommendation for the therapeutic use of any particular agent beyond standard supportive treatment.

Mycobacterial diseases remain a significant cause of morbidity and mortality worldwide. Rifampicin and ethambutol are among the drugs recommended by WHO as first-line treatment. In this work, we addressed the question whether doses of the two anti-tuberculosis agents ethambutol and rifampicin transferred to a nursed infant could be of health concerns when the mother is under treatment. We used the approach of pharmacokinetic modelling using a structural model with two interconnected organisms: the first one being the organism of the nursing mother and the second one being the organism of the nursed child. Physiological data were taken from the literature. The models were parameterised by data from the literature concerning clearance, absorption and plasma/milk ratio. Distribution into the tissues was calculated by an algorithm. The predictive power of the model was tested by comparing the predicted plasma concentrations in the mothers with measured data from the literature. Comparison with measured data after direct infant treatment was performed for the rifampicin plasma concentrations predicted in the nursed infant. Both comparisons confirmed the appropriateness of the modelling results. The transfer of 0.08 mg/kg bw/day ethambutol via breast milk to the nursed infant, the dose we have estimated, when the mother received a therapeutic dose of 24.5 mg/kg bw, can be judged as being without health concern. Likewise, for rifampicin, the transferred dose of 0.4 mg/kg bw to the nursed infant resulting from a therapeutic dose of 10.9 mg/kg bw to the mother does not raise health concerns.

Allergic contact dermatitis is a widespread health disorder and occupational skin disease. Hence, screening for contact-sensitizing chemicals is highly relevant to toxicology, dermatology, and occupational medicine. The use of animal tests for this purpose is constrained by ethical considerations, need for high-throughput screening, and legislation (e.g., for cosmetics in the European Union). T cell activation is the final and most specific key event of the “adverse outcome pathway” for skin sensitization and therefore a promising target for the development of in vitro sensitization assays. We present a novel in vitro sensitization assay with a lymphocyte endpoint as an add-on to the loose-fit coculture-based sensitization assay (LCSA): the LCSA-ly. While the LCSA measures dendritic cell activation, the LCSA-ly offers the option for an additional lymphocyte endpoint which can be measured concurrently. We incorporated lymphocytes in our previously established coculture of primary human keratinocytes and monocyte-derived dendritic cells and tested nine substances: five sensitizers [2,4-dinitrochlorobenzene (DNCB) 1.25–15 µmol/l, p-phenylenediamine (PPD) 15.6–125 µmol/l, 2-mercaptobenzothiazole (MBT) 50–1000 µmol/l, coumarin, and resorcinol (both: 250–1500 µmol/l)] and four non-sensitizers (monochlorobenzene, caprylic acid, glycerol, and salicylic acid (all: 125–1000 µmol/l)]. DNCB and MBT increased a subset of IL-23 receptor+/IFN-γ receptor 1 (CD119)+ lymphocytes. DNCB, PPD, and MBT enhanced a subunit of the IL-4 receptor (CD124) and a memory marker (CD44) on lymphocytes. Remarkably, DNCB, PPD, and MBT raised IL-4 concentrations in coculture supernatants while IFN-γ levels decreased, which might point to Th2 activation in vitro. Coumarin, resorcinol, and non-sensitizers did not alter any of the tested surface markers or cytokines. IL-17 was not affected by any of the substances. Relative strength of sensitizers according to lymphocyte markers was DNCB > PPD > MBT, which corresponds to earlier results from the LCSA without lymphocyte endpoint, the murine local lymph node assay, and human data. This study is the first to prove the suitability of lymphocyte surface markers for sensitization testing and potency assessment.

ZusammenfassungIn Deutschland ist seit 2015 ein deutlicher Anstieg der gemeldeten Tuberkulosefälle zu verzeichnen. Zurückzuführen ist dieser vor allem auf die aktuell vermehrte Migration. Durch die niedrige Inzidenz in den vorhergehenden Jahren konzentriert sich die Erfahrung im Umgang mit Tuberkulose immer mehr auf spezialisierte Zentren. Pneumologen wie auch andere Fachbereiche sind nun aber wieder häufiger an der Behandlung einer Tuberkulose beteiligt, sodass Fachwissen zur Standardtherapie wie auch zu selteneren Therapiesituationen benötigt wird. Die aktuelle Leitlinie zur Diagnostik und Therapie, einschließlich Chemoprävention und -prophylaxe im Erwachsenenalter fasst den derzeitigen Wissensstand zusammen und passt die Empfehlungen an die Situation in Deutschland an. Realisiert wurde die AWMF S2k-Leitlinie durch das Deutsche Zentralkomitee zur Bekämpfung der Tuberkulose e. V. (DZK) im Auftrag der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin e. V. (DGP). Zur Behandlung der Tuberkulose im pädiatrischen Bereich wird in Kürze eine eigenständige Leitlinie der entsprechenden Fachgesellschaften veröffentlicht. Im Vergleich zu den Empfehlungen von 2012 sind eigenständige Kapitel zur Labordiagnostik und zum therapeutischen Medikamentenmanagement entstanden. Die Kapitel Mehrfachresistenzen gegen Medikamente der Standardtherapie, HIV-Koinfektion und die Übersicht der Arzneimittel wurden erweitert. Die umfangreiche Überarbeitung der Empfehlungen soll Ärzten und auch anderen Beschäftigten im Gesundheitswesen helfen, den aktuellen Herausforderungen im Umgang mit dem selten gewordenen Tuberkuloseerreger zu begegnen.

Some nucleoside analogues are used to treat herpes simplex and other viral infections. They are known to impair spermatogenesis, but published data are scarce. We studied the effects of four nucleosides on SerW3 cells, a rat Sertoli cell line. Cells were cultured for 3 days in DMEM supplemented with four different concentrations of each drug. Aciclovir and ganciclovir were added at concentrations of 0.3, 1, 3 and 10 mg/l medium; penciclovir and its prodrug famciclovir were used at higher concentrations (3, 10, 30, 100 mg/l medium). After a culture period of 3 days, we analysed the expression of connexin43, N-cadherin and the cytoskeleton protein vimentin by Western blot. Aciclovir caused a clear-cut effect at the highest concentration tested (10 mg/l), which is less than the peak plasma concentration achieved in patients during intravenous therapy with the drug. Connexin43, vimentin and N-cadherin content decreased to 49.8 ± 17, 44.0 ± 4 and 75.4 ± 1.5 % of the control values, respectively (n = 3; mean ± SD). Similar effects were observed with the prodrug ganciclovir (43.2 ± 10.8; 54.1 ± 11.9; 84.4 ± 10.8 % of controls). Penciclovir caused less pronounced effects at 10 mg/l medium (82.1 ± 20.6; 90.0 ± 12.0; 76.5 ± 17.7 % of controls). Only a slight effect was observed with famciclovir. Even at a 10-fold concentration (100 mg/l), just moderate changes were induced. In summary, we observed clear-cut effects with aciclovir and ganciclovir on Sertoli cells in vitro at therapeutically relevant concentrations and identified connexin43 as the most sensitive marker.

The in vitro sensitization assay LCSA (Loose-fit Coculture-based Sensitization Assay) has proved reliable for the detection of contact sensitizers in the past. However, the coculture of human monocyte-derived dendritic cells (DCs) with primary human keratinocytes (KCs) in serum-free medium is relatively complex compared to other sensitization assays which use continuous cell lines. To facilitate high-throughput screening of chemicals, we replaced KCs with the HaCaT cell line under various culture conditions. Coculture of HaCaT with peripheral blood mononuclear cells in serum-supplemented medium leads to generation of CD1a+/CD1c+ DCs after addition of GM-CSF, IL-4, and TGF-β1 (as opposed to CD1a−/CD1c− DCs which arise in the “classic” LCSA coculture). These cells resemble monocyte-derived DCs generated in monoculture, but, unlike those, they show a marked upregulation CD86 after treatment with contact allergens. All of the nine sensitizers in this study were correctly identified by CD1a+/CD1c+ DCs in coculture with HaCaT. Among the substances were weak contact allergens such as propylparaben (which is false negative in the local lymph node assay in mice) and resorcinol (which was not detected by CD1a−/CD1c− DCs in the “classic” LCSA). The level of CD86 upregulation on CD1a+/CD1c+ DCs was higher for most allergens compared to CD1a−/CD1c− DCs, thus improving the assay’s discriminatory power. Three out of four non-sensitizers were also correctly assessed by the coculture assay. A false-positive reaction to caprylic (octanoic) acid confirms earlier results that some fatty acids are able to induce CD86 on DC in vitro. In conclusion, change of the LCSA protocol led to reduction of time and cost while even increasing the assay’s sensitivity and discriminatory power.

Unsaturated compounds are known to cause false-positive reactions in the local lymph node assay (LLNA) but not in the guinea pig maximization test. We have tested a panel of substances (succinic acid, undecylenic acid, 1-octyn-3-ol, fumaric acid, maleic acid, linoleic acid, oleic acid, alpha-linolenic acid, squalene, and arachidonic acid) in the loose-fit coculture-based sensitization assay (LCSA) to evaluate whether unspecific activation of dendritic cells is a confounder for sensitization testing in vitro. Eight out of 10 tested substances caused significant up-regulation of CD86 on dendritic cells cocultured with keratinocytes and would have been classified as sensitizers; only succinic acid was tested negative, and squalene had to be excluded from data analysis due to poor solubility in cell culture medium. Based on human data, only undecylenic acid can be considered a true sensitizer. The true sensitizing potential of 1-octyn-3-ol is uncertain. Fumaric acid and its isomer maleic acid are not known as sensitizers, but their esters are contact allergens. A group of 18- to 20-carbon chain unsaturated fatty acids (linoleic acid, oleic acid, alpha-linolenic acid, and arachidonic acid) elicited the strongest reaction in vitro. This is possibly due to the formation of pro-inflammatory lipid mediators in the cell culture causing nonspecific activation of dendritic cells. In conclusion, both the LLNA and the LCSA seem to provide false-positive results for unsaturated fatty acids. The inclusion of T cells in dendritic cell-based in vitro sensitization assays may help to eliminate false-positive results due to nonspecific dendritic cell activation. This would lead to more accurate prediction of sensitizers, which is paramount for consumer health protection and occupational safety.

Vor dem Hintergrund der abnehmenden Empfindlichkeit vieler Erreger gegen die verfugbaren antibakteriellen Wirkstoffe erscheint eine optimale Dosierung der Antibiotika notwendiger als je zuvor, um ein Therapieversagen und / oder eine Forderung der Resistenzentwicklung zu vermeiden. Eine Berucksichtigung des jeweiligen Korpergewichts, der Nieren- und Leberfunktion des Patienten, sowie der Pharmakodynamik und Pharmakokinetik des verabreichten Antibiotikums sollte individuelle Dosierungen ermoglichen. Dieses optimierte Vorgehen konnte die Wirksamkeit und Sicherheit der Therapie bedeutsam erhohen. Als eine wesentliche Voraussetzung fur eine pharmakokinetisch basierte, optimierte Dosierung werden entsprechende Studien bei ubergewichtigen Patienten wahrend der klinischen Prufung neuer Antibiotika gefordert. Auch bei intensivmedizinisch behandelten Patienten ist aufgrund der pathophysiologischen Veranderungen das pharmakokinetische Verhalten von Antibiotika oft deutlich verandert. Ein vergrosertes Verteilungsvolumen, eine erhohte Clearance und eine reduzierte Proteinbindung machen hohere Dosierungen notwendig. Andererseits muss bei einer akuten renalen Insuffizienz die Dosis in der Regel reduziert werden und / oder das Dosierungsintervall muss verlangert werden. Die Nierenfunktion sollte mit Hilfe der Kreatinin-Clearance beurteilt werden. Eine Abschatzung mit den ublichen Formeln fuhrt bei kritisch Kranken zu falschen Ergebnissen, eine Ermittlung uber Sammelurin ist sinnvoll. Allerdings ist bisher nur in wenigen prospektiven Studien der Einfluss alternativer Dosierungen hinsichtlich des Therapieergebnisses uberpruft worden. Hier sind weitere, umfangreiche Studien notwendig.

Since 2015 a significant increase in tuberculosis cases is notified in Germany, mostly due to rising numbers of migrants connected to the recent refugee crisis. Because of the low incidence in previous years, knowledge on tuberculosis is more and more limited to specialized centers. However, lung specialist and healthcare workers of other fields have contact to an increasing number of tuberculosis patients. In this situation, guidance for the management of standard therapy and especially for uncommon situations will be essential. This new guideline on tuberculosis in adults gives recommendations on diagnosis, treatment, prevention and prophylaxis. It provides a comprehensive overview over the current knowledge, adapted to the specific situation in Germany. The German Central Committee against Tuberculosis (DZK e. V.) realized this guideline on behalf of the German Respiratory Society (DGP). A specific guideline for tuberculosis in the pediatrics field will be published separately. Compared to the former recommendations of the year 2012, microbiological diagnostics and therapeutic drug management were given own sections. Chapters about the treatment of drug-resistant tuberculosis, tuberculosis in people living with HIV and pharmacological management were extended. This revised guideline aims to be a useful tool for practitioners and other health care providers to deal with the recent challenges of tuberculosis treatment in Germany.In Deutschland ist seit 2015 ein deutlicher Anstieg der gemeldeten Tuberkulosefälle zu verzeichnen. Zurückzuführen ist dieser vor allem auf die aktuell vermehrte Migration. Durch die niedrige Inzidenz in den vorhergehenden Jahren konzentriert sich die Erfahrung im Umgang mit Tuberkulose immer mehr auf spezialisierte Zentren. Pneumologen wie auch andere Fachbereiche sind nun aber wieder häufiger an der Behandlung einer Tuberkulose beteiligt, sodass Fachwissen zur Standardtherapie wie auch zu selteneren Therapiesituationen benötigt wird. Die aktuelle Leitlinie zur Diagnostik und Therapie, einschließlich Chemoprävention und -prophylaxe im Erwachsenenalter fasst den derzeitigen Wissensstand zusammen und passt die Empfehlungen an die Situation in Deutschland an. Realisiert wurde die AWMF S2k-Leitlinie durch das Deutsche Zentralkomitee zur Bekämpfung der Tuberkulose e. V. (DZK) im Auftrag der Deutschen Gesellschaft für Pneumologie und Beatmungsmedizin e. V. (DGP). Zur Behandlung der Tuberkulose im pädiatrischen Bereich wird in Kürze eine eigenständige Leitlinie der entsprechenden Fachgesellschaften veröffentlicht. Im Vergleich zu den Empfehlungen von 2012 sind eigenständige Kapitel zur Labordiagnostik und zum therapeutischen Medikamentenmanagement entstanden. Die Kapitel Mehrfachresistenzen gegen Medikamente der Standardtherapie, HIV-Koinfektion und die Übersicht der Arzneimittel wurden erweitert. Die umfangreiche Überarbeitung der Empfehlungen soll Ärzten und auch anderen Beschäftigten im Gesundheitswesen helfen, den aktuellen Herausforderungen im Umgang mit dem selten gewordenen Tuberkuloseerreger zu begegnen.

Parabens, methylisothiazolinone (MI) and its derivative methylchloroisothiazolinone (MCI), are commonly used as preservatives in personal care products. They can cause hypersensitivity reactions of the human skin. We have tested a set of nine parabens, MI alone and in combination with MCI in the loose-fit coculture-based sensitization assay (LCSA). The coculture of primary human keratinocytes and allogenic dendritic cell-related cells (DC-rc) in this assay emulates the in vivo situation of the human skin. Sensitization potency of the test substances was assessed by flow cytometric analysis of the DC-rc maturation marker CD86. Determination of the concentration required to cause a half-maximal increase in CD86-expression (EC50sens) allowed a quantitative evaluation. The cytotoxicity of test substances as indicator for irritative potency was measured by 7-AAD (7-amino-actinomycin D) staining. Parabens exhibited weak (methyl-, ethyl-, propyl- and isopropylparaben) or strong (butyl-, isobutyl-, pentyl- and benzylparaben) effects, whereas phenylparaben was found to be a moderate sensitizer. Sensitization potencies of parabens correlated with side chain length. Due to a pronounced cytotoxicity, we could not estimate an EC50sens value for MI, whereas MI/MCI was classified as sensitizer and also showed cytotoxic effects. Parabens showed no (methyl- and ethylparaben) or weak irritative potencies (propyl-, isopropyl-, butyl-, isobutyl-, phenyl- and benzylparaben), only pentylparaben was rated to be irritative. Overall, we were able to demonstrate and compare the sensitizing potencies of parabens in this in vitro test. Furthermore, we showed an irritative potency for most of the preservatives. The data further support the usefulness of the LCSA for comparison of the sensitizing potencies of xenobiotics.

In den vergangenen 50 Jahren haben sich die Methicillin-resistenten S. aureus-Stamme (MRSA) weltweit verbreitet. Nach wie vor ist Vancomycin das uberwiegend empfohlene Antibiotikum zur Behandlung entsprechender Infektionen. Teicoplanin stellt eine Alternative mit langerer Halbwertzeit dar. Telavancin ist ein neueres Vancomycin-Derivat, das in klinischen Studien etwa gleich wirksam wie Vancomycin war. Bei Patienten mit Niereninsuffizienz sollte es nicht angewandt werden. Nephrotoxische Wirkungen der Glykopeptide schranken ihre therapeutische Verwendbarkeit ein. Das Oxazolidinon Linezolid ist dem Vancomycin therapeutisch gleichwertig bis uberlegen. Bei einer Therapie mit dieser Substanz sind Blutbildkontrollen notwendig, neurotoxische Wirkungen wurden vor allem bei langerer Behandlungsdauer beobachtet. Beachtet werden mussen die Interaktionen mit serotoninerg wirksamen Arzneistoffen. Neue Moglichkeiten eroffnen sich mit Ceftarolin, dem ersten MRSA-wirksamen β-Laktamantibiotikum. Kontrollierte Studien bei pulmonalen MRSA-Infektionen liegen allerdings nicht vor. Daptomycin, ein Lipopeptid, und Tigecyclin, ein Glycylcyclin, zeigen in vitro ebenfalls Aktivitat gegen MRSA, kommen aber zur Behandlung pulmonaler MRSA-Infektionen ebenfalls nicht in Betracht. Am Beispiel dieser Antibiotika wird deutlich, dass der Nachweis einer in vitro-Aktivitat zwar von Bedeutung ist, dass aber die fur eine Therapieentscheidung notwendigen Erkenntnisse nur aus doppelblind-randomisierten klinischen Studien abgeleitet werden konnen.

Die Zahl der adiposen Patienten nimmt in Deutschland und anderen Landern zu. Die Bedeutung des erhohten Korpergewichts als Risikofaktor fur diverse Erkrankungen ist gut untersucht, zur Frage der Adipositas-bedingten Disposition fur Infektionen gibt es allerdings relativ wenige Studien. Pulmonale Infektionen, Hautinfektionen, postoperative Infektionen und einige andere werden aber offenbar durch eine Adipositas begunstigt. Angesichts der abnehmenden Empfindlichkeit vieler Erreger gegen die verfugbaren antibakteriellen Wirkstoffe, erscheint eine optimale Dosierung der Antibiotika notwendiger als je zuvor. Durch individuell berechnete Dosierungen sollte eine optimierte Therapie zur Anwendung kommen. Ein solches Vorgehen kann den Erfolg der Therapie erhohen, einer Resistenzausbreitung entgegenwirken und schlieslich auch das Risiko fur unerwunschte Wirkungen reduzieren. Als eine wesentliche Voraussetzung fur eine optimierte Therapie wird die Durchfuhrung entsprechender Studien bei ubergewichtigen Patienten gefordert, da die Theorie-basierten Moglichkeiten der Dosisberechnung begrenzt sind.

The TTC concept uses toxicological data from animal testing to derive generic human exposure threshold values (TTC values), below which the risk of adverse effects on human health is considered to be low. It uses distributions of no-observed-adverse-effect levels (NOAELs) for substances. The 5th percentile value is divided by an uncertainty factor (100) to give a TTC value. As the toxicological data underpinning the TTC concept are from tests with oral exposure, the exposure is to be understood as an external oral exposure. For risk assessment of substances with a low absorption (by the oral route, or through skin), the internal exposure is more relevant than the external exposure. European legislation allows that tests might not be necessary for substances with negligible absorption with low internal exposure. The aim of this work is to derive internal TTC values to allow the TTC concept to be applied to situations of low internal exposure. The external NOAEL of each chemical of three databases (Munro, ELINCS, Food Contact Materials) was multiplied by the bioavailability of the individual chemical. Oral bioavailability was predicted using an in silico prediction tool (ACD Percepta). After applying a reduced uncertainty factor of 25, we derived internal TTC values. For Cramer class I, the internal TTC values are 6.9 μg/kg bw/d (90 % confidence interval: 3.8-11.5 mg/kg bw/d); for Cramer class II/III 0.1 μg/kg bw/d (90 % confidence interval: 0.08-0.14 μg/kg bw/d).

Glaucoma comprises age-related neurodegenerative diseases of retinal ganglion cells, the worldwide prevalence of which is increasing. Local pharmacotherapy is the primary treatment option, especially in the elderly. But this therapeutic approach may include risks for adverse drug effects and drug–drug interactions, of particular importance in frail nursing home resident populations. The aim of the present study was to investigate anti-glaucoma pharmacotherapy in nursing home residents in the context of multi-morbidity and related systemic co-medication. Data for 8,685 nursing home residents with 88,695 drug prescriptions were analysed according to diagnosis and local or systemic pharmacotherapy. Data were provided in anonymous form by a German public health insurance company. The study cohort was characterized by a mean age of 83.6 ± 7.3 years (range: 65–106 years), 21 % of nursing home residents were at least 90 years old and 83.7 % were women. For each nursing home resident, an average of 6.0 ± 3.3 different drugs were registered. A diagnosis of glaucoma was recorded in 520 (6.0 %) nursing home residents; all subjects had co-existing medical conditions. Dementia was a frequent co-morbidity, diagnosed in 51.7 % of nursing home residents with glaucoma. Anti-glaucoma drugs contributed to 0.5 % of all prescriptions and were prescribed to 341 nursing home residents. The most frequently used anti-glaucoma ophthalmics were β-blockers (n = 219), followed by prostaglandin analogues (n = 101) and carbonic anhydrase inhibitors (n = 86). Local anti-glaucoma therapy was co-prescribed with a systemic pharmacotherapy in 338 nursing home residents. An ophthalmic agent was, on average, combined with 6.5 ± 3.2 prescriptions for systemic agents. Thus, 71.9 % of nursing home residents were prescribed ophthalmic β-blockers and a concomitant antihypertensive medication; local and systemic β-blockers were combined in 20.2 % of these patients. Co-treatment with cardiac glycosides or calcium antagonists was found in 13 % of nursing home residents prescribed ophthalmic parasympathomimetics, and in 14 % of those prescribed ophthalmic β-blockers, with the potential for drug–drug interactions to influence cardiac function. Anti-glaucoma pharmacotherapy in nursing home residents is frequently prescribed in the context of polypharmacy. This may modify the efficacy and safety of local and systemic therapies. Therefore, individualized pharmacotherapy that integrates anti-glaucoma drug therapy into the overall treatment rationale in nursing home residents is necessary. However, to realize this concept, further clinical research in nursing home residents is warranted.

The benzimidazole carbamate albendazole (ABZ), a potent anthelmintic, is a teratogenic compound in rats. At present it is unclear to which degree this effect is caused by the parent compound or its major metabolite, albendazole sulfoxide (ASO). Both substances were studied separately and in combinations to mimic incomplete bioactivation in two in vitro tests: mouse embryonic stem cell test (EST) and rat whole embryo culture (WEC). In both assays, ABZ and mixtures with ASO induced detrimental effects at lower concentrations compared to ASO alone. While ABZ caused half-maximal effects on cardiomyocyte differentiation at a mean concentration of 0.26 ++M (EST) and dysmorphogenic development of rat embryos at 3.7 ++M (WEC), effective concentrations of ASO were similar in both assays (10-13 ++M). By using WEC and EST we demonstrate that ABZ exhibits stronger inherent embryotoxic potency although ASO might be the proximate teratogen in vivo because of higher plasma concentrations.

Resveratrol, an activator of histone deacetylase Sirt-1, has been proposed to have beneficial health effects due to its antioxidant and anti-inflammatory properties. However, the mechanisms underlying the anti-inflammatory effects of resveratrol and the intracellular signaling pathways involved are poorly understood. An in vitro model of human tenocytes was used to examine the mechanism of resveratrol action on IL-1β-mediated inflammatory signaling. Resveratrol suppressed IL-1β-induced activation of NF-κB and PI3K in a dose- and time-dependent manner. Treatment with resveratrol enhanced the production of matrix components collagen types I and III, tenomodulin, and tenogenic transcription factor scleraxis, whereas it inhibited gene products involved in inflammation and apoptosis. IL-1β-induced NF-κB and PI3K activation was inhibited by resveratrol or the inhibitors of PI3K (wortmannin), c-Src (PP1), and Akt (SH-5) through inhibition of IκB kinase, IκBα phosphorylation, and inhibition of nuclear translocation of NF-κB, suggesting that PI3K signaling pathway may be one of the signaling pathways inhibited by resveratrol to abrogate NF-κB activation. Inhibition of PI3K by wortmannin attenuated IL-1β-induced Akt and p65 acetylation, suggesting that p65 is a downstream component of PI3K/Akt in these responses. The modulatory effects of resveratrol on IL-1β-induced activation of NF-κB and PI3K were found to be mediated at least in part by the association between Sirt-1 and scleraxis and deacetylation of NF-κB and PI3K. Overall, these results demonstrate that activated Sirt-1 plays an essential role in the anti-inflammatory effects of resveratrol and this may be mediated at least in part through inhibition/deacetylation of PI3K and NF-κB.

Mycophenolic acid (MPA) is an immunosuppressive agent that acts as a selective, non-reversible inhibitor of the enzyme inosine-5'-monophosphate dehydrogenase (IMPDH). Malformations have been described in children after maternal exposure to mycophenolate. However, the causal link is unclear in most cases because women had been treated with a combination of drugs and birth defects may have other causes. Therefore, it is important to study the action of this drug and its main metabolite on embryonic tissue. We studied the teratogenic potential of MPA and its major metabolite, the mycophenolic acid glucuronide (MPAG) in the rat whole-embryo culture. A total of 147 day 9.5 embryos were cultivated for 48 h in the standard medium containing 85 % serum. We tested MPA at concentrations of 0.1; 0.25; 0.5; 0.75 mg/l (0.31; 0.78; 1.56; 2.34 μM) and MPA glucuronide at concentrations of 3; 10; 30; 100 mg/l (6.04; 20.14; 60.43; 201.43 μM). Both substances are highly protein bound, and MPA glucuronide might displace MPA from protein binding. Therefore, we examined whether the effects of MPA can be enhanced when studied in combination with the glucuronide. Furthermore, the focus was on additional endpoints to the standard evaluation of cultivated embryos, such as development of cranial nerves [trigeminal nerve (V), facial nerve (VII), glossopharyngeal nerve (IX), vagus nerve (X)] after staining with an antibody against 2H3 neurofilament. Ultrastructural changes were evaluated by electron microscopy. At a concentration of 0.75 mg MPA/l medium, all embryos showed dysmorphic changes. Embryos exposed to 0.25 mg MPA/l medium showed impaired development of nerves, and at 0.1 mg/l, no effects were detectable. Concentration-dependent ultrastructural changes, such as signs of apoptosis, were found by electron microscopy. The examination of the metabolite in this assay showed that at a concentration of 100 mg MPAG/l, the embryos exhibited distinct malformations. This is probably caused by MPA, which was detectable at 0.6 % in the material used for our experiments. The combination of the parent compound (0.03; 0.1; 0.25 mg/l) with its metabolite MPAG (3 mg/l) did not cause enhanced toxicity under our experimental conditions. IMPDH, the target enzyme of MPA, could be detected in rat embryos on day 9.5 of embryonic development as well as at the end of the culture period 48 h later. In summary, MPA impairs embryonic development at low, therapeutically relevant concentrations, but the glucuronide does not exhibit such a potential. Activity of MPA is not enhanced by MPAG.

Tendon overuse injuries and tendinitis are accompanied by catabolic processes and apoptosis of tenocytes. However, the precise molecular mechanisms of the destructive processes in tendon are not fully understood. Sirt-1, a nicotinamide adenine dinucleotide (NAD(+))-dependent deacetylase, has been linked to transcriptional silencing and appears to play a key role in inflammation. The purpose of this study was to examine whether down-regulation of Sirt-1 using antisense oligonucleotides (ASO) affects inflammatory and apoptotic signaling in tenocytes. Transient transfection of tenocytes with ASO against Sirt-1 induced expression of Bax and other proteins involved in apoptosis (cleaved caspase-3 and poly(ADP-ribose)polymerase), acetylation of tumor suppressor p53, and mitochondrial degradation. Interestingly, Sirt-1 was found to interact directly with p53. In contrast, Sirt-1 activator resveratrol inhibited interleukin-1β (IL-1β)- and nicotinamide-induced NF-κB activation and p65 acetylation and suppressed the activation of IκB-α kinase. Resveratrol also reversed the IL-1β- or nicotinamide-induced up-regulation of various gene products that mediate inflammation (cyclooxygenase-2) and matrix degradation (matrix metalloproteinase-9) that are known to be regulated by NF-κB. Knockdown of Sirt-1 by using ASO abolished the inhibitory effects of resveratrol on inflammatory and apoptotic signaling including Akt activation and SCAX suppression. Down-regulation of histone deacetylase Sirt-1 by mRNA interference abrogated the effect of resveratrol on NF-κB suppression, thus highlighting the crucial homeostatic role of this enzyme. Overall, these results suggest for the first time that Sirt-1 can regulate p53 and NF-κB signaling via deacetylation, demonstrating a novel role for resveratrol in the treatment of tendinitis/tendinopathy.

Antimikrobielle Medikamente konnen Arzneimittelnebenwirkungen am Auge verursachen. Sie werden meist durch Veranderungen an den vorderen Augensegmenten oder durch Schmerzen und Sehstorungen bemerkt. Da die Moglichkeit der Reversibilitat von ihrem moglichst fruhen Erkennen abhangt, ist es wichtig, dass Arzte aber auch Patienten fur die Symptome sensibilisiert sind und uber die moglichen gravierenden Folgen Bescheid wissen. Bei der Therapie mit Voriconazol klagen ungefahr ein Drittel der Patienten uber Sehstorungen nach der ersten Gabe, im Allgemeinen sind die Symptome rasch reversibel ohne weitere Schadigung des Auges. Telithromycin kann wahrend der Therapie durch seine anticholinerge Aktivitat die Akkommodation storen. Neuropathien des Nervus opticus konnen durch Ethambutol, Isoniazid, Streptomycin und Linezolid verursacht werden. Die ersten Symptome, wie Storungen im Farbensehen, treten typischerweise mit einer Latenz von einigen Wochen nach Therapiebeginn auf. Schwerwiegende Langzeitschaden der visuellen Funktion konnen die Folge sein. Als zugrunde liegende Mechanismen werden toxische Wirkungen auf die Mitochondrien in den retinalen Ganglienzellen angenommen. Rifabutin und Cidofovir konnen intraokulare Entzundungen verursachen, Cidofovir zusatzlich eine erhebliche Minderung des okularen Druckes. Arzneimittelnebenwirkungen sind von der Dosis abhangig und dadurch beeinflusst von einer gestorten Nieren- oder Leberfunktion, der Pharmakogenetik oder durch Arzneimittelwechselwirkungen. Mogliche schwerwiegende durch Medikamente induzierte Nebenwirkungen am Auge erfordern eine intensive Zusammenarbeit mit einem Augenarzt fur die gemeinsame Bewertung des individuellen Risiko- Nutzenverhaltnisses, wenn moglich sogar vor Beginn der antimikrobiellen Therapie.

Chloracne is a characteristic marker of intoxication by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or related compounds. Decreased lipogenesis is a prominent clinical sign in this disease. However, the activity of dioxins on human sebaceous glands is still unclear. In this study, the effects of TCDD on sebaceous gland differentiation were studied both in human skin samples maintained ex vivo and in cultured SZ95 sebocytes. Aryl hydrocarbon receptor (AhR) protein expression, the receptor for dioxin, was detected in SZ95 sebocytes. Its expression was markedly inhibited by TCDD. Furthermore, we detected a reduced release of neutral lipids (10(-10) -10(-8) M; P

We have developed a coculture system which in parallel indicates the sensitizing and irritative potential of xenobiotics. The assay is named loose-fit coculture-based sensitization assay (LCSA) and may be performed within 5 days. The system is composed of human monocytes that differentiate to a kind of dendritic cells by 2-day culturing in the presence of allogenic keratinocytes. The culture medium is enriched by a cocktail of recombinant cytokines. On day 3, concentration series of probes are added. On day 5, cells are harvested and analyzed for expression range of CD86 as a marker of sensitizing potential and for uptake of the viability stain 7-AAD as a marker of irritative potential. Estimation of the concentration required to cause a half-maximal increase in CD86 expression allowed quantification of sensitizing potential, and estimation of the concentration required to reduce viability to 50% allowed quantification of irritative potential. Examination of substances with known potential resulted in categorization of test scores. To evaluate our data, we have compared results with those of the validated animal-based sensitization test, the murine local lymph node assay (LLNA, OECD TG 429). To a large extent, results from LCSA and from LLNA achieved analogous grouping of allergens into categories like weak-moderate-strong. However, the new assay showed an improved capacity to distinguish sensitizers from non-sensitizers and irritants. In conclusion, the LCSA contains potential to fulfil the requirements of the EU's programme for the safety of chemicals "Registration, Evaluation, Authorization and Restriction of chemical substances" (REACH, 2006) to replace animal models.

The fluoroquinolones ciprofloxacin, levofloxacin, moxifloxacin and gemifloxacin are widely used for the treatment of various types of bacterial infections. Overall, these antibacterial agents can be considered safe and well tolerated drugs. Comparative studies have evaluated the use of quinolones in elderly and younger populations. Although age per se does not seem to decrease their tolerability, specific adverse effects of the quinolones must be considered when they are chosen for antibacterial treatment. Renal function declines consistently with age and doses of renally excreted quinolones (e.g. ofloxacin, levofloxacin, gatifloxacin) need to be adjusted if a clinically relevant reduction of creatinine clearance is identified. Reactions of the gastrointestinal tract, such as nausea, dyspepsia, vomiting or diarrhoea, are among the most often registered adverse drug reactions during therapy with fluoroquinolones. Treatment with a quinolone causes diarrhoea less frequently than treatment with other classes of antimicrobials. Conflicting data have been published with respect to the incidence of Clostridium difficile-associated diarrhoea in quinolone-treated patients. Hypersensitivity reactions, often manifested on the skin, occur less commonly during therapy with quinolones than, for example, during therapy with beta-lactam antibacterials. Adverse reactions of the CNS are of particular concern in the elderly population. Given the CNS excitatory effects of quinolones, elderly patients should be monitored carefully for such symptoms. It is likely that many signs of possible adverse reactions, such as confusion, weakness, loss of appetite, tremor or depression, are often mistakenly attributed to old age and remain unreported. Quinolones should be used with caution in patients with known or suspected CNS disorders that predispose to seizures (e.g. severe cerebral arteriosclerosis or epilepsy). Quinolones can cause QT interval prolongation. They should be avoided in patients with known prolongation of the QT interval, patients with uncorrected hypokalaemia or hypomagnesaemia and patients receiving class IA (e.g. quinidine, procainamide) or class III (e.g. amiodarone, sotalol) antiarrhythmic agents. Tendinitis and tendon ruptures are recognized as quinolone-induced adverse effects that can occur during treatment or as late as several months after treatment. Chronic renal diseases, concomitant use of corticosteroids and age60 years are known risk factors for quinolone-induced tendopathies. Overall, the specific adverse-effect profile of quinolones must be considered when they are chosen for treatment of bacterial infections. Because of physiological changes in renal function and when certain co-morbidities are present, some special considerations are necessary when elderly patients are treated with these drugs.

Evaluation of the prenatal toxicity of a substance in rats or other animals according to the current guidelines is often hampered by the rapid metabolism of the test compound and/or by maternal toxicity. One example for such a compound is moxifloxacin. In vitro systems offer the possibility to study the direct effects of the test compound on embryonic tissues. The aim of this study was to evaluate the embryotoxic potential of moxifloxacin in vitro using the murine limb bud culture. Clinafloxacin, which was found to be teratogenic when tested in rats, was used for comparison. The effects of various concentrations of moxifloxacin (10, 30, 60 and 100 mg/L) and clinafloxacin (3, 10 and 30 mg/L) on growth and differentiation of 12-day-old murine limb buds were studied in a standard and in a magnesium-deficient medium. After termination of the culture, the respective front limb buds were examined by different methods. Clinafloxacin showed clear-cut effects at a concentration of 30 mg/L in both media. Effects were similarly pronounced as the effects observed with moxifloxacin at a concentration of 100 mg/L. Lower concentrations of moxifloxacin, which are achieved during therapy in humans, did not impair growth and differentiation of limb buds. Using electron microscopy, slight ultrastructural changes could be seen after exposure to 3 mg clinafloxacin/L medium. Ultrastructurally, clinafloxacin caused a concentration-dependent decrease of the extracellular matrix, swelling of cell organelles and at higher concentrations necrotic chondrocytes. These effects were significantly enhanced in a magnesium-deficient medium. In conclusion, the effects of moxifloxacin on murine limb buds in vitro were definitely less pronounced than those of clinafloxacin. Effects on growth and differentiation occurred with moxifloxacin only at concentrations that are higher than plasma concentrations observed during therapy. This result is of special interest, because due to rapid metabolism of moxifloxacin in rats results from a routinely performed segment II type study cannot be used for a risk assessment.

Mycophenolate mofetil is a widely used immunosuppressive drug that recently has been categorized as a human teratogen. Animal experiments indicate a teratogenic potential of the drug, but so far, it has not been studied in embryotoxicity in vitro assays. The aim of this study was to evaluate the in vitro embryotoxic potential of mycophenolic acid and investigate the ability of such tests to detect its embryotoxic potential. We used two validated assays: the rat whole embryo culture and the murine embryonic stem cell test. Rat embryos cultured from gestational day 9.5 for 48 h with the drug showed dysmorphogenic development already at a concentration of 250 microg mycophenolic acid/l medium. At concentrations of 750 microg/l and more, all rat embryos exhibited malformations. The main effects were defective yolk sac blood circulation, neural tube defects (open cranial neural pore), malformations of the head with missing eye anlagen and heart anomalies. Moreover, the exposed embryos showed a concentration-dependent decrease in protein content, crown-rump length, number of somites and morphological score. The murine embryonic stem cell test was slightly more sensitive. Proliferation and differentiation of the ES-D3-cells were significantly impaired at concentrations of 31 and 125 microg mycophenolic acid/l medium, respectively. In the differentiation assay, at a concentration of 125 microg mycophenolic acid/l medium and more, the number of wells with differentiated cardiomyocytes significantly decreased. Additionally, a cytotoxicity assay with balb/c 3T3 mouse fibroblasts was used to compare the proliferation and vitality of embryonic cells with adult cells. In the balb/c 3T3 cytotoxicity assay, the number of vital mouse fibroblasts significantly decreased at a mycophenolic acid concentration of 62 microg/l and more. In conclusion, by using the two validated in vitro tests, we showed that mycophenolic acid exhibits a pronounced embryotoxic potential at cytotoxic concentrations. This result from validated in vitro tests is of special interest, because it supports the use of the tests to detect human teratogens.

Spermatogenesis is a very complex process by which male germ cells differentiate into mature spermatozoa. The sophisticated communication network that controls spermatogenesis can be derailed so that dysfunction of one cell type propagates to all types as a cascade. This accounts for the particular vulnerability of the testis to environmental factors such as drugs and xenobiotics. Sertoli cells play an important role in protecting developing germ cells by forming a physiological barrier, limiting exposure to potentially toxic substrates, or conversely, facilitating uptake of xenobiotics within the testis. In this study, cells from the rat Sertoli line (SerW3) were incubated for 3, 6 and 9 subsequent days in serum free DMEM (SFDM) composed of DMEM supplemented with three different concentrations of antibiotic gentamicin (10, 30, and 100 μg). The effect of the three different concentrations of this antibiotic was determined on Sertoli cell–cell interaction through impaired expression of their constitutive tight junction proteins as early targets for different toxicants in vitro by immunochemistry analysis. The Sertoli SerW3 cell line illustrated the cytotoxicity of GS, as the intercellular junction proteins such as occludin, N-cadherin, connexin 43, and vimentin were delocalized from the membrane to the cytoplasmic compartment during exposure to the antibiotic. This study underlines the potential deleterious effects of the routine use of antibiotics during continuous cell culture.

Protection against contact allergy begins with the collection of reliable data about the sensitizing potential of chemicals. Today, the local lymph node assay (LLNA) in mice is widely used to identify sensitizing substances. For several reasons, an in vitro assay could be preferable to animal experiments. We propose an in vitro test for the detection of a sensitizing potential of a chemical composed of a single layer of human nondifferentiating keratinocytes and of allogenic floating monocytes which are cocultured in serum-free medium in the presence of a cytokine cocktail. Within days, the coculture develops to an allergen- sensitive system consisting of activated keratinocytes and of mobile dendritic cell-related cells (DC-related cell). The sensitizing potential can be determined by analyzing the expression of the dendritic cell maturation marker CD86. For the model contact allergens tested so far [trinitrobenzenesulfonic acid (TNBS), phenylendiamine, and 4-aminoacetanilide], the strength of the reaction was in concordance with results from the LLNA. Sensitivity of the assay allowed testing at concentrations without general cytotoxicity. Thus, a differentiation between allergens and irritants was possible. Regarding cytokine secretion, the assay distinguished between the allergen TNBS and the Toll-like receptor ligand lipopolysaccharide. The coculture can be set up from cryopreserved cells. The assay is easy to perform and reproducible. Donor-variance is negligible. This in vitro assay based on a loose-fit coculture is a reasonable approach to screen for the sensitizing potential of xenobiotics and might partially replace the LLNA and other animal tests.

Oxazolidinones are synthetic antimicrobials with strong bacteriostatic activity against Gram-positive organisms. Recently, tedizolid phosphate was approved for clinical use becoming the second agent of this class after linezolid available in clinical practice.Oxazolidinone pharmacology including structure-activity relationships, mode of action, pharmacokinetics, drug-drug interactions, and adverse drug reactions is reviewed. Furthermore, bacterial resistance, approved indications, use in paediatric populations, and tuberculosis treatment with oxazolidinones are discussed, and differences in indications and pharmacotoxicological properties between the two approved agents are elucidated. A MEDLINE PubMed search for articles published in English from January 1960 to June 2015 was completed using the terms: oxazolidinone, oxazolidinone-induced toxicity, oxazolidinone pharmacokinetics, serotonin syndrome, oxazolidinone drug-drug interactions, antituberculotic treatment.Linezolid illustrates an important antimicrobial in several Gram-positive infections especially when methicillin-resistant Staphylococcus aureus strains are involved. Myelosuppression and neuropathy are toxicities of high relevance particularly in case of prolonged treatment periods. The significance of linezolid in the treatment of extensively drug-resistant tuberculosis has to be further investigated. Tedizolid phosphate represents a welcome addition in our anti-infective arsenal, and future research will clarify its role in indications other than the already approved acute bacterial skin infections.

We used a physiologically based kinetic model to simulate caffeine blood concentration-time profiles in non-pregnant and pregnant women. The model predicted concentration-time profile was in good accordance with experimental values. With 200 mg, the safe dose per occasion in non-pregnant women, AUC and peak concentration in pregnant women were nearly twice that of non-pregnant women. In order to derive a safe dose for the pregnant women we estimated the dose in the pregnant women model taken at once which would not exceed AUC and peak concentration in the non-pregnant women of 200 mg as single dose. The resulting dose is 100 mg caffeine per occasion which we recommend as safe. The caffeine dose of 200 mg per day is declared as safe for pregnant women with respect to the foetus by EFSA based on results on reduced birth weight in epidemiological studies. We modelled AUC and peak concentration for different caffeine doses to investigate the relationship between internal caffeine exposure and risk measures of reduced birth weight from epidemiological studies. The graphical analysis revealed that the reduction in birth weight was related to AUC and peak concentration up to a dose of 250 mg caffeine.

Against the background of reduced susceptibility of many pathogens to available antibacterial agents an optimized dosing of antibiotics is of increasing importance to avoid therapeutic failures and / or microbial resistance. Consideration of the individual body weight, as well as kidney and liver function of a patient and the pharmacodynamics and pharmacokinetic properties of the antibiotic should enable an individualized dosing. An optimized approach could increase efficacy and safety of an antimicrobial therapy significantly. Aimed studies in overweight patients during the clinical development of a new antibiotic are necessary as a substantial prerequisite for a pharmacokinetically based optimized dosing. Intensive care patients also exhibit major changes in pharmacokinetics of antibiotics due to pathophysiological changes. An increased volume of distribution, an increased clearance and reduced protein binding require treatment with increased doses. On the other hand, in patients with acute renal failure often doses have to be reduced and / or the dosing interval has to be prolonged. Renal function should be assessed on the basis of the creatinine clearance. An estimation with the often applied plasma creatinine-based equations can lead to wrong results in critically ill patients, a directly measured urinary creatinine clearance is a more reasonable procedure. However, so far only few prospective studies which investigated the effect of alternative dosing strategies on the therapeutic outcome have been published. Certainly, further comprehensive studies are necessary.

Infusion phlebitis is a common clinical problem that is observed with some antimicrobial agents, when being administered intravenously. In this study, cultured murine fibroblasts and immortalised human endothelial cells were exposed to three antibiotics at clinically relevant concentrations to assess their toxic potential in two established cytotoxicity assays. BALB/c 3T3 fibroblasts and Eahy926 endothelial cells were exposed to quinupristin/dalfopristin (QD), erythromycin and levofloxacin at increasing concentrations. For assessment of cytotoxicity the cells were incubated with neutral red (NR) or stained with crystal violet (CV). Measurements were done by photometry. At the concentration range tested QD and erythromycin showed a concentration-dependent cytotoxic effect in both cell cultures. In 3T3 cells the half-maximal effect concentration (EC50) was 20 mg/l for QD and 340 mg/l for erythromycin in the NR uptake test and 12 and 200 mg/l, respectively, in the CV assay. In Eahy926 cells the EC50 was 50 mg/l for QD and 880 mg/l for erythromycin in the NR uptake test and 40 and 750 mg/l, respectively, in the CV assay. No EC50 could be established in both cell types for levofloxacin. Eahy926 cells were less sensitive to cytotoxic stimuli than 3T3 fibroblasts. Cytotoxic effects in both cell cultures occurred in the following order: QD > erythromycin >> levofloxacin. This ranking correlates well with the frequency of local adverse effects observed with the infusion of these antibiotics in patients. Thus, these in vitro assays may serve as an estimate for the prediction of local tolerability of antibiotics when administered parenterally.

2,3,7,8-Tetrachloro-dibenzo- p -dioxin (TCDD) is an ubiquitously distributed xenobiotic. It has been postulated that the effects of TCDD on T-lymphocytes are mediated by modulation of the thymic microenvironment. There is growing evidence of a modified interplay between thymocytes and thymic epithelium related to changes in extracellular matrix (ECM) proteins. Eighteen male marmosets ( Callithrix jacchus ) were treated with single subcutaneous TCDD doses (1, 10, 100 ng/kg body weight) or vehicle and sacrificed 2 or 4 weeks thereafter. Thymus samples were stained with fluorescein isothiocyanate-conjugated antibodies for ECM proteins and examined immunohistochemically by semi-quantitative image analysis. Thymus samples of animals treated with 1 and 10 ng/kg were additionally analysed by Western blotting for ECM proteins, transforming growth factor-β 1 (TGF-β 1 ) and integrin chain content (CD49a, CD49e, CD49f and CD29). Monkeys showed no overt signs of toxicity after TCDD treatment. Immunohistochemistry revealed an increase of ECM proteins at 100 ng/kg after 2 and 4 weeks. Western blotting confirmed immunohistochemistry showing a dose-dependent increase of several ECM proteins in animals treated with the lower TCDD doses of 1 and 10 ng/kg. Additionally, dose-dependent increases were observed in integrin chain and TGF-β 1 contents. We demonstrated changes of thymic ECM in marmosets following low single TCDD doses. Combined with altered integrin expression and enhanced TGF-β 1 stimulation our findings suggest a modified interplay between thymic epithelium and thymocytes. The extracellular matrix may play a more central role in mediating adverse effects of TCDD in organs than yet acknowledged.

Trotz der unerwunschten Wirkungen der β-Lactam-Antibiotika insbesondere auf das gastrointestinale System und in Form von Uberempfindlichkeitsreaktionen, sind die Vertreter dieser Substanzklasse als gut vertragliche antibakterielle Therapeutika anzusehen. Dies wird auch durch den weit verbreiteten Einsatz in der Padiatrie unterstrichen. Ein rationaler Einsatz der β-Lactam-Antibiotika und die Moglichkeit eine Uberempfindlichkeit auf diese Arzneimittelgruppe mit Hilfe von genauer Anamnese, Hauttests und Blutanalysen einzugrenzen, kann die Risiken einer β-Lactam-Therapie minimieren.

Antimicrobial therapy with fluoroquinolones can be associated with tendinitis and other tendon disorders as an adverse reaction associated with this class of antimicrobials. Here we investigated aspects of the mechanism of quinolone-induced tendotoxicity in human tenocytes focussing mainly on the question whether fluoroquinolones may induce apoptosis. Monolayers of human tenocytes were incubated with ciprofloxacin or levofloxacin at different concentrations (0, 3, 10, 30 and 100mg/L medium) for up to 4 days. Ultrastructural changes were studied by electron microscopy, and alterations in synthesis of specific proteins were determined using immunoblotting. At concentrations, which are achievable during quinolone therapy, 3mg ciprofloxacin/L medium significantly decreased type I collagen; similar changes were observed with 3mg ciprofloxacin or 10mg levofloxacin/L medium for the beta(1)- integrin receptors. Effects were intensified at higher concentrations and longer incubation periods. Cytoskeletal and signalling proteins, such as activated shc or erk 1/2, were significantly reduced by both fluoroquinolones already at 3mg/L. Furthermore, time- and concentration-dependent increases of matrix metalloproteinases as well as of the apoptosis marker activated caspase-3 were found. Apoptotic changes were confirmed by electron microscopy: both fluoroquinolones caused typical alterations like condensed material in the nucleus, swollen cell organelles, apoptotic bodies and bleb formation at the cell membrane. Our results provide evidence that besides changes in receptor and signalling proteins apoptosis has to be considered as a final event in the pathogenesis of fluoroquinolone-induced tendopathies.