Abstract 5505: Synergistic anticancer activity of clinical stage, non-genotoxic apoptosis inducing agents RG7388 (MDM2 antagonist) and ABT-199 (GDC-0199, BCL2 inhibitor) in p53 wild-type AML tumor models

MDM2, the most prominent natural inhibitor of the p53 tumor suppressor pathway, and BCL2, an anti-apoptotic regulator and important player in preventing induction of apoptosis in tumor cells, both play a pivotal role in leukemia cell survival and response to therapy in the clinic.

The principal objectives of this study were to assess a synergistic antitumor effect by combining the clinical stage compounds RG7388, a MDM2 antagonist reactivating p53, and the BCL2 selective inhibitor GDC-0199 and to elucidate the underlying mechanism of action. Further insight into the biological rationale for this potential therapeutic strategy may pave the path for clinical combination studies in AML patients.

We first investigated the effect of co-treatment with RG7388 and GDC-0199 on the viability and induction of apoptosis in AML tumor cell lines followed by high-resolution cell cycle kinetic analysis using BrdU-Hoechst quenching technology in-vitro.

Cell viability assays demonstrated synergistic potency of combined RG7388 and GDC-0199 treatment with low nM IC50 values. Subsequent annexin binding assays confirmed the efficacy and revealed different kinetics of apoptosis induction. To further explain the mode of action, high-resolution cell cycle compartment analysis of consecutive cell cycles was performed. Mechanistically, RG7388 induces G1 arrest and preferentially causes nuclear fragmentation in G1 phase of the second cycle. The BCL2 inhibitor GDC-0199 mainly causes apoptosis in G1 compartments and hence cells transiently protected from apoptosis by RG7388 induced G1 arrest are hit by GDC-0199.

In addition we analyzed changes in expression of pro- and anti-apoptotic genes and proteins upon combined treatment using qRT-PCR, Western Blot and Luminex technology. We identified down-modulation of MCL-1 levels, a known GDC-0199 resistance factor, as one potential mechanism for the synergistic efficacy and confirmed this finding by shRNA experiments in-vitro.

Furthermore, the efficacy of the compounds was assessed in subcutaneous and orthotopic AML tumor cell line based xenograft models in-vivo, confirming the synergy observed in-vitro.

Taken together, our study demonstrates that combined treatment with RG7388 and GDC-0199 shows a synergistic anticancer effect on AML cells. This indicates that activating the p53 tumor suppressor pathway and inhibiting a key anti-apoptosis target simultaneously induces a more than additive inhibitory effect by modulating the levels of key pro-survival proteins, such as Mcl-1, thereby further lowering the apoptotic threshold level for tumor cell death.

Based on the observations from our study, the combined administration of RG7388 and GDC-0199 might offer a promising new therapeutic regimen for treating AML patients.

Citation Format: Markus Dangl, Yuchen Chien, Christian Lehmann, Thomas Friess. Synergistic anticancer activity of clinical stage, non-genotoxic apoptosis inducing agents RG7388 (MDM2 antagonist) and ABT-199 (GDC-0199, BCL2 inhibitor) in p53 wild-type AML tumor models. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5505. doi:10.1158/1538-7445.AM2014-5505

Structures and Properties of Diastereomeric Multi-component Crystals

Multi-component crystals composed of two different chiral molecules have the potential to form diastereomers. In the present study a selection of chiral amides and acids was employed to form multi-component crystals. Since growing these multi-component crystals from solution failed, solvent assisted grinding was used. The resulting diastereomeric pairs, which are present as polycrystalline powders showed distinctly different powder diffraction patterns. In order to elucidate the crystal structures direct space global optimization structure solution methods were successfully used in several cases. A potential application of these diastereomeric multi-component crystals is the determination of the absolute configuration of one of the two components based on the known absolute configuration of the other.[1] In addition, Raman spectroscopy and DSC were employed to determine thermodynamic properties. In subsequent grinding experiments racemic conglomerates and racemates formed the starting material. These experiments demonstrated in several cases a relationship between melting point differences and preferential formation of only one diastereomer.

Charge density study of the first mixed-valent tetraphosphete

The first λ3,λ5-tetraphosphete contains a 4π-electron four-membered ring as the central structural unit of a dispirocyclic system and can thus be classified as an analogue to diphosphetes and cyclodiphosphazenes. According to its crystal structure the central P4unit exhibits not only P–P bonds which are of equal length (P1–P2 2,139(1) Å, P1–P2A 2,142(1) Å), but also rhombic distortion (P1–P2–P1A 79,4(1)0, P2–P1–P2A 100,6(1)0).[1] Therefore its electronic structure cannot be described as 'Phosphacyclobutadiene' but either as a bis(ylide) or as a system with delocalized double bonds. After various quantum chemical calculations and an extensive examination of its reaction and coordination behavior failed to answer this question, we addressed the problem via a detailed analysis of its charge density distribution. The experimental charge density based on high resolution X-ray diffraction data collected at low temperature is determined by multipole least squares refinement using the program packageXD2006.[2] In a first step, the static deformation density exhibits charge density which is located mainly outside of the P4ring plane at the λ3-phosphorus atoms but simultaneously redistributed into the P–P bond area. In addition to that, a study of its topological properties and an inspection of the Laplacian of the electron density according to Bader's `Quantum Theory of Atoms in Molecules' (QTAIM)[3] further highlight the bonding features. They reveal polar Si–N, Si–C and P–N bonds with a decreasing amount of electrostatic contribution as well as four valence shell charge concentrations (thus sp3hybridization) at each of the phosphorus atoms. Finally supported by theoretical calculations, the results illustrate the unique bonding situation in the P4unit combining a high ylidic character with unusual not exclusively sigma-like P–P bonds.

Art as behaviour--an ethological approach to visual and verbal art, music and architecture

In recent years, the fine arts, architecture, music and literature have increasingly been examined from the vantage point of human ethology and evolutionary psychology. In 2011 the authors formed the research group 'Ethology of the Arts' concentrating on the evolution and biology of perception and behaviour. These novel approaches aim at a better understanding of the various facets represented by the arts by taking into focus possible phylogenetic adaptations, which have shaped the artistic capacities of our ancestors. Rather than culture specificity, which is stressed e.g. by cultural anthropology and numerous other disciplines, universal human tendencies to perceive, feel, think and behave are postulated. Artistic expressive behaviour is understood as an integral part of the human condition, whether expressed in ritual, visual, verbal or musical art. The Ethology of the Arts-group's research focuses on visual and verbal art, music and built environment/architecture and is designed to contribute to the incipient interdisciplinarity in the field of evolutionary art research.

Plasmon-enhanced Raman scattering by carbon nanotubes optically coupled with near-field cavities

We realize the coupling of carbon nanotubes as a one-dimensional model system to near-field cavities for plasmon-enhanced Raman scattering. Directed dielectrophoretic assembly places single-walled carbon nanotubes precisely into the gap of gold nanodimers. The plasmonic cavities enhance the Raman signal of a small nanotube bundle by a factor of 10(3). The enhanced signal arises exclusively from tube segments within the cavity as we confirm by spatially resolved Raman measurements. Through the energy and polarization of the excitation we address the extrinsic plasmonic and the intrinsic nanotube optical response independently. For all incident light polarizations, the nanotube Raman features arise from fully symmetric vibrations only. We find strong evidence that the signal enhancement depends on the orientation of the carbon nanotube relative to the cavity axis.

Echocardiographic screening for pulmonary arterial hypertension in HIV-positive patients

Human immunodeficiency virus (HIV) infection is associated with an increased risk for pulmonary arterial hypertension (PAH). Upon the screening of 220 asymptomatic HIV-positive individuals by echocardiography, we detected and confirmed HIV-associated PAH in 0.45 % of cases. Mild elevations of systolic pulmonary arterial pressure most probably owing to left ventricular diastolic dysfunction were found in 7.7 % of cases, without progress after 2 years. We suggest that the screening of asymptomatic HIV-positive patients for PAH should not be performed.

The last bite was deadly--about responsibility in scientific publishing

Some open access journals are believed to have devaluated the highly respected image of the scientific journal. This has been, it is claimed, verified. Yet the project we believe failed and we show why we think that it failed. The study itself was badly conducted and the report, which Science published, was itself a perfect example of "bad science". If the article that was published in Science were to be taken as one of the "test" articles and Science as a victim journal (a perfect control though), the study would show the opposite of what author concluded in his paper: 100% of the controls (normal non-open access journals, in the present study this was Science) accepted the "bait" paper for publication, while in the experimental group only about 60% (open access journals) accepted the bait paper for publication. The conclusion is that, with respect to non-open access and open access, the probability of accepting pseudoscience is well in favor of this being done by a non-open access journal. Since this interpretation is based on some facts that were not included in the project itself, the only warranted result of this study would be that nothing could be concluded from it. It is concluded that the method that Bohannon used was heavily flawed and in addition immoral; that the report that was published by Science was inconclusive and that the act of publishing such report cannot be morally justified either. Various methods to improve the quality of published papers exist but scientific fraud with "good intentions" as a method to promote scientific publishing should be avoided.

Comparison of cold crystalloid and colloid infusions for induction of therapeutic hypothermia in a porcine model of cardiac arrest

Introduction

Large-volume cold intravenous infusion of crystalloids has been used for induction of therapeutic hypothermia after cardiac arrest. However, the effectiveness of cold colloids has not been evaluated. Therefore, we performed an experimental study to investigate the cooling effect of cold normal saline compared to colloid solution in a porcine model of ventricular fibrillation.

Methods

Ventricular fibrillation was induced for 15 minutes in 22 anesthetized domestic pigs. After spontaneous circulation was restored, the animals were randomized to receive either 45 ml/kg of 1°C cold normal saline (Group A, 9 animals); or 45 ml/kg of 1°C cold colloid solution (Voluven®, 6% hydroxyethyl starch 130/0.4 in 0.9% NaCl) during 20 minutes (Group B, 9 animals); or to undergo no cooling intervention (Group C, 4 animals). Then, the animals were observed for 90 minutes. Cerebral, rectal, intramuscular, pulmonary artery, and subcutaneous fat body temperatures (BT) were recorded. In the mechanical ex-vivo sub study we added a same amount of cold normal saline or colloid into the bath of normal saline and calculated the area under the curve (AUC) for induced temperature changes.

Results

Animals treated with cold fluids achieved a significant decrease of BT at all measurement sites, whereas there was a consistent significant spontaneous increase in group C. At the time of completion of infusion, greater decrease in pulmonary artery BT and cerebral BT in group A compared to group B was detected (−2.1 ± 0.3 vs. -1.6 ± 0.2°C, and −1.7 ± 0.4 vs. -1.1 ± 0.3°C, p < 0.05, respectively). AUC analysis of the decrease of cerebral BT revealed a more vigorous cooling effect in group A compared to group B (−91 ± 22 vs. -68 ± 23°C/min, p = 0.046). In the mechanical sub study, AUC analysis of the induced temperature decrease of cooled solution revealed that addition of normal saline led to more intense cooling than colloid solution (−7155 ± 647 vs. -5733 ± 636°C/min, p = 0.008).

Conclusions

Intravenous infusion of cold normal saline resulted in more intense decrease of cerebral and pulmonary artery BT than colloid infusion in this porcine model of cardiac arrest. This difference is at least partially related to the various specific heat capacities of the coolants.

Causes of death in HIV-infected patients from the Cologne-Bonn cohort

PURPOSE

Causes of death in human immunodeficiency virus (HIV)-infected subjects have changed in countries with high resources over the last several years. Acquired immunodeficiency syndrome (AIDS)-related diseases have become less prevalent, whereas deaths due to non-AIDS causes are increasing. The aim of the present study was to analyse causes of death in the Cologne-Bonn cohort.

METHODS

Causes of death from the Cologne-Bonn cohort between 2004 and 2010 were systematically recorded using the CoDe algorithm (The Coding Causes of Death in HIV Project).

RESULTS

In 3,165 patients followed from 2004 to 2010, 182 deaths occurred (5.7 %, 153 males, 29 females). The median age at the time of death was 47 years (range 24-85 years). The most frequent causes of death were AIDS-defining events (n = 60, 33 %), with non-Hodgkin lymphoma (NHL) (n = 29, 16 %) and infections (n = 20, 11 %) being the leading entities in this category. Non-AIDS malignancies accounted for 16 % (n = 29), non-HIV-related infections for 10 % (n = 18), cardiovascular diseases for 7 % (n = 14), suicide or accident for 4 % (n = 7) and liver diseases for 3 % (n = 5) of deaths (unknown n = 47, 26 %). Although the majority of patients (92.5 %) was on antiretroviral therapy (ART), only 50 % were virologically suppressed (HIV-RNA <50 copies/mL) and 44 % had a decreased CD4+ count (<200/μL) at their last visit before death.

CONCLUSION

One-third of the causes of death in our cohort between 2004 and 2010 was AIDS-related. Since most of these deaths occur with severe immune suppression, they can possibly be prevented by the early diagnosis and treatment of HIV infection. Care providers must be aware of an increased risk for a broad range of diseases in HIV-infected patients and should apply appropriate preventive measures.

An observational assessment of the sublingual microcirculation of pregnant and non-pregnant women

BACKGROUND

The microcirculation is responsible for distribution of blood within tissues, delivery of oxygen and other nutrients, and regulation of blood pressure. The objective of this study was to compare the sublingual microcirculation of pregnant participants to that of comparable non-pregnant volunteers.

METHODS

Two groups of participants were recruited: a group of pregnant, non-laboring women with singleton pregnancies at term gestation and a control group of age-comparable non-pregnant volunteers. A sidestream dark field imaging device was applied to the sublingual mucosal surface obtaining a steady image for at least 20 s duration, in five visual fields. The resultant five video clips per participant were analyzed blindly and at random to prevent coupling between images. The mean microvascular flow index values for each group were compared using a paired t-test.

RESULTS

Thirty-seven participants were recruited (19 pregnant, 18 non-pregnant); a single pregnant participant was withdrawn because of technical issues. Baseline characteristics were similar with the exception of weight and body mass index. The mean microvascular flow index was significantly higher in the pregnant group 2.7 ± 0.2 compared to the non-pregnant group 2.5 ± 0.3 (P = 0.021), while the perfused vessel density and proportion of perfused vessels were not significantly different (P = 0.707 and 0.403, respectively).

CONCLUSION

The microvascular flow index of pregnant women is higher than a comparable non-pregnant group, which appears to correlate with the physiological changes of pregnancy.

Evaluation of an infectious disease consultation programme in a German tertiary care hospital

PURPOSE

To evaluate a newly implemented infectious disease (ID) consultation service in terms of patient care, outcome and antibiotic prescription and to describe factors influencing adherence to recommendations.

METHODS

Data from consultations during the first 6 months of the ID consultation program were collected and evaluated. Consultation requests, diagnostic results, treatment outcomes and antibiotic recommendations were categorised. Diagnostic and therapeutic recommendations were assessed and rated for adherence and outcome. Statistical analysis was performed to identify factors influencing adherence and treatment outcome.

RESULTS

A total of 251 consultations were assessed. In most cases, ID specialists were asked for further advice regarding a previously initiated anti-infective treatment (N = 131, 52 %). In 54 of 195 (28 %) first consultations, the ID specialist proposed a differential diagnosis that differed from that of the working diagnoses submitted with the consultation request, and which was subsequently confirmed in 80 % of these cases. Diagnostic and therapeutic recommendations were made in 190 (76 %) and 240 (96 %) of the consultations, respectively. A change in the current treatment was recommended in 66 % of consultations; 37 % of recommendations were cost-saving and 26 % were cost-neutral. Compliance with diagnostic and therapeutic recommendations was rated as good by pre-specified criteria in 65 and 86 % of consultations, respectively. Treatment outcome was correlated with adherence to diagnostic recommendations (P = 0.012). Twenty-nine patients (16 %) died during the same hospital stay.

CONCLUSION

Infectious disease consultations may help to establish the correct diagnosis, resulting in the appropriate treatment being provided to a severely sick patient population. Treatment outcome was improved in cases of good diagnostic adherence to the recommendations of the ID specialist.

Microcirculation diagnostics and applied studies in circulatory shock - research from the bench to the bedside

Macrohemodynamic targets such as mean arterial pressure, cardiac output, and mixed or central venous oxygen saturation have been used to guide treatment of patients presenting circulatory shock. However, it has been shown that despite of improvement of macrocirculatory parameters there is persisting microcirculatory dysfunction. The restoration of microvascular perfusion in order to improve oxygenation, prevent tissue hypoxia, and maintain organ function represents the main aim of hemodynamic resuscitation. Therefore, microcirculatory targets may represent the most important endpoints to optimize therapy of circulatory shock.

Increasing protein production by directed vector backbone evolution

Recombinant protein production in prokaryotic and eukaryotic organisms was a key enabling technology for the rapid development of industrial and molecular biotechnology. However, despite all progress the improvement of protein production is an ongoing challenge and of high importance for cost-effective enzyme production. With the epMEGAWHOP mutagenesis protocol for vector backbone optimization we report a novel directed evolution based approach to increase protein production levels by randomly introducing mutations in the vector backbone. In the current study we validate the epMEGAWHOP mutagenesis protocol for three different expression systems. The latter demonstrated the general applicability of the epMEGAWHOP method. Cellulase and lipase production was doubled in one round of directed evolution by random mutagenesis of pET28a(+) and pET22b(+) vector backbones. Protease production using the vector pHY300PLK was increased ~4-times with an average of ~1.25 mutations per kb vector backbone. The epMEGAWHOP does not require any rational understanding of the expression machinery and can generally be applied to enzymes, expression vectors and related hosts. epMEGAWHOP is therefore from our point of view a robust, rapid and straight forward alternative for increasing protein production in general and for biotechnological applications.

Inhibition of endocannabinoid degradation in experimental endotoxemia reduces leukocyte adhesion and improves capillary perfusion in the gut

BACKGROUND

Changes in leukocyte-endothelial and microvascular perfusion are hallmark events in inflammation. Thus, protection of the intestinal microcirculation represents a pivotal therapeutic target in systemic inflammation and sepsis. The endocannabinoid system (ECS) modulates a number of critical homeostatic functions and has been associated with anti-inflammatory responses. Our study aimed to examine intestinal leukocyte adhesion and capillary perfusion following selective inhibition of the endocannabinoid degradation enzyme, fatty acid amide hydrolase (FAAH), in experimental sepsis (endotoxemia).

METHODS

Five groups of rats were used: controls, endotoxemia [lipopolysaccharide (LPS)], FAAH inhibitor URB597 (0.3 mg/kg)+LPS, URB597 (0.6 mg/kg)+LPS, and URB597 (0.6 mg/kg)+cannabinoid 2 receptor (CB2R) antagonist (AM630)+LPS. After 2 h, intravital microscopy was performed to quantify intestinal leukocyte recruitment and functional capillary density (FCD), as well as macrohemodynamic monitoring and histological examinations.

RESULTS

LPS induced a significant increase in leukocyte adhesion in collecting and postcapillary submucosal venules and a decrease in intestinal FCD. URB597 pretreatment prevented the LPS-induced increase in leukocyte adhesion in intestinal venules and a decrease in intestinal FCD. The administration of the CB2R inhibitor, AM630, with URB597 reversed the protective effects of URB597 on the LPS-induced increase in leukocyte adhesion in intestinal venules, but not URB597's effect on the intestinal FCD.

CONCLUSIONS

FAAH inhibition prevents the LPS-induced increase in leukocyte adhesion and improves the capillary perfusion of the gut. This might be mediated in part by CB2R activation. Our study encourages further investigation into the therapeutic potential of drugs targeting the ECS in sepsis.

Cannabinoid receptor 2 activation reduces intestinal leukocyte recruitment and systemic inflammatory mediator release in acute experimental sepsis

INTRODUCTION

Cannabinoid receptor 2 (CB2R) expression is upregulated during sepsis. However, there are conflicting results regarding the effects of CB2R modulation in the hyperinflammatory phase of the disease. The aim of this study was therefore to investigate the effects of CB2R manipulation on leukocyte activation within the intestinal microcirculation in two acute experimental sepsis models.

METHODS

In the endotoxemia model we studied four groups of Lewis rats: controls, lipopolysaccharide (LPS), LPS + CB2R agonist HU308 (2.5 mg/kg), and LPS + CB2R antagonist AM630 (2.5 mg/kg). In the colon ascendens stent peritonitis (CASP)-induced sepsis model we also studied four groups: sham group, CASP and CASP + CB2R agonist (HU308, 2.5 or 10 mg/kg). Intravital microscopy was performed 2 hours following LPS/placebo administration or 16 hours following CASP/sham surgery to quantify intestinal leukocyte recruitment. Additionally, hemodynamic monitoring, histological examinations and measurements of inflammatory mediators were performed.

RESULTS

HU308 administration significantly reduced intestinal leukocyte adhesion in both acute sepsis models. The systemic levels of inflammatory mediators were significantly reduced by 10 mg/kg HU308 treatment in CASP animals.

CONCLUSION

CB2R activation reduces leukocyte activation and systemic release of inflammatory mediators in acute experimental sepsis. Drugs targeting the CB2R pathway may have therapeutic potential in sepsis.

Established breast cancer stem cell markers do not correlate with in vivo tumorigenicity of tumor-initiating cells

The tumor-initiating capacity of primary human breast cancer cells is maintained in vitro by culturing these cells as spheres/aggregates. Inoculation of small cell numbers derived from these non-adherent cultures leads to rapid xenograft tumor formation in mice. Accordingly, injection of more differentiated monolayer cells derived from spheres results in significantly decelerated tumor growth. For our study, two breast cancer cell lines were generated from primary tumors and cultured as mammospheres or as their adherent counterparts. We examined the in vivo tumorigenicity of these cells by injecting serial dilutions into immunodeficient mice. Inoculation of 10⁶ cells per mouse led to rapid tumor formation, irrespective of cell line or culture conditions. However, after injection of only 10³ cells, solely sphere cells were highly tumorigenic. In vitro, we investigated differentiation markers, established breast CSC markers and conducted mRNA profiling. Cytokeratin 5 and 18 were increased in both monolayer cell types, indicating a more differentiated phenotype. All cell lines were CD24⁻/CD44⁺ and did not express CD133, CD326 or E-cadherin. ALDH1 activity was not detectable in any cell line. A verapamil-sensitive Hoechst side population was present in sphere cells, but there was no correlation with tumorigenicity in vivo. mRNA profiling did not reveal upregulation of relevant transcription factors. In vitro cell cycle kinetics and in vivo tumor doubling times displayed no difference between sphere and monolayer cultures. Our data indicate that intrinsic genetic and functional markers investigated are not indicative of the in vivo tumori-genicity of putative breast tumor-initiating cells.

A generic systolic array building block for neural networks with on-chip learning

Neural networks require VLSI implementations for on-board systems. Size and real-time considerations show that on-chip learning is necessary for a large range of applications. A flexible digital design is preferred here to more compact analog or optical realizations. As opposed to many current implementations, the two-dimensional systolic array system presented is an attempt to define a novel computer architecture inspired by neurobiology. It is composed of generic building blocks for basic operations rather than predefined neural models. A full custom VLSI design of a first prototype has demonstrated the efficacy of this design. A complete board dedicated to Hopfield's model has been designed using these building blocks. Beyond the very specific application presented, the underlying principles can be used for designing efficient hardware for most neural network models.

[Doctor-patient interaction: dealing with difficult situations]

Good doctor-patient communication has a positive impact on patient satisfaction, adherence to treatment, health outcomes and well-being, and it has been linked to reduced anxiety, increased recall, and improved understanding. During the diagnostic phase and the course of the illness, patients exhibit a range of mood changes. These include sadness and worry, frustration and anger, uncertainty, fear of disease recurrence, difficulties in inter-personal relationships, changing roles, and concerns about body image. Medical consultations can be influenced by different expectations concerning the doctor-patient interaction, by individual roles and beliefs, and by a different understanding of health and well-being influenced by cultural and other factors not necessarily associated with the medical situation. Responding to anger and other difficult emotions, dealing with family meetings, or communicating via interpreters are often experienced as demanding situations by health care professionals. This article provides an overview of the difficult doctor-patient interactions and illustrates basic communication skills in responding to challenging situations.

Organic cation transporters OCT1 and OCT2 determine the accumulation of lamivudine in CD4 cells of HIV-infected patients

PURPOSE

Identifying factors that determine concentrations of antiretroviral drugs in CD4 cells are important for improving therapeutic efficacy. Experimental models indicate that the nucleoside reverse transcriptase inhibitor lamivudine is transported by the organic cation transporters 1 and 2 (OCT1 and OCT2, respectively). Here, we tested whether OCT1 and OCT2 contribute to the uptake of lamivudine into native CD4 cells of human immunodeficiency virus (HIV)-infected individuals.

METHODS

CD4 cells obtained by non-activated cell sorting from 35 individuals with HIV-1 infection were incubated with lamivudine (10 μM, 30 min), and intracellular concentrations of lamivudine and its active metabolite lamivudine triphosphate were determined by liquid chromatography tandem mass spectrometry. The expression of OCT1 and OCT2 mRNA was measured by quantitative real-time polymerase chain reaction (PCR). A model of OCT2-transfected CD4 cells was established for mechanistic investigations.

RESULTS

Intracellular concentrations of lamivudine and its active metabolite lamivudine triphosphate showed strong linear correlations with each other and with the CD4 mRNA expression of OCT1 and OCT2 (r > 0.80). Coincubation with protease inhibitors (ritonavir, nelfinavir) that inhibit OCT1 and OCT2 yielded decreased intracellular concentrations of lamivudine and lamivudine triphosphate. Incubation of CD4 cells from healthy donors transfected with an OCT2 expression vector yielded increased concentrations of lamivudine and lamivudine triphosphate.

CONCLUSION

Our studies indicate a role of OCT1 and OCT2 for the cellular accumulation of lamivudine in HIV-infected individuals.

Metabolomic analysis as biomarker to study steroid hormone administration in sepsis

Sepsis is a life-threatening disease requiring rapid diagnosis and treatment. Steroid hormones (e.g., estradiol, dehydroepiandosterone) have been suggested to reduce the hyper-inflammatory response of the immune system and to improve outcome in sepsis. We hypothesize that the impact of steroid hormones on the metabolic profile (metabolomic fingerprint) can be used to study and guide steroid hormone administration in sepsis. Potential biomarker candidates are sphingomyelines and phosphatidylcholines.

Weiterbildung in der Zeitarbeit – Einflussfaktoren und Erfolg

Zeitarbeit hat sich für die deutsche Wirtschaft zu einem wichtigen Flexibilisierungsinstrument entwickelt. Dem zunehmenden Mangel an neuen, qualifizierten Zeitarbeitnehmern kann auch in der Zeitarbeit durch die Qualifizierung bestehender Mitarbeiter begegnet werden. Auch wenn Weiterbildung oft noch ein Stiefkind in der Zeitarbeit ist, zeigen sich Erfolgssteigerungen von Zeitarbeitsunternehmen durch Weiterbildung. Investitionen in die Weiterbildung von Zeitarbeitskräften amortisieren sich nicht nur durch höhere Verleihsätze, sondern auch durch eine gesteigerte Attraktivität für Mitarbeiter und Kunden. Dieser Beitrag soll beantworten, (1) welche Bedingungen das Auftreten und den Umfang betrieblicher Weiterbildung durch Personaldienstleister beeinflussen und (2) inwieweit Weiterbildung ein Erfolgsfaktor für Personaldienstleister darstellt. Unsere Studie zeigt, dass sowohl Strukturmerkmale der Verleiher als auch die Nutzungsmotive der Entleiher den Weiterbildungsumfang beeinflussen. Darüber hinaus weisen wir nach, dass Weiterbildung die Wettbewerbsfähigkeit von Personaldienstleistern fördert.

Liver involvement in HIV-infected patients diagnosed with syphilis

PURPOSE

Liver involvement in syphilis has been studied in cohorts of human immunodeficiency virus (HIV)-negative individuals despite the scarcity of data on such HIV-infected patients. Th aim of this study was to assess hepatic involvement of HIV-infected patients diagnosed with syphilis.

METHODS

Patients with syphilis and liver involvement, including all stages of syphilis, were systematically identified in our HIV cohort between 2004 and 2008.

RESULTS

Of the 1,599 HIV-infected patients identified during the study period, 100 were diagnosed with acute syphilis, all of whom were male. Of these 100 patients, 84% were men who have sex with men. Laboratory parameters of liver involvement were present in 19 of the 100 HIV-infected patients with syphilis; these resolved after successful antibiotic treatment. Among these 19 patients, six were diagnosed to be in the latent stage, with elevated liver enzymes and parameters of inflammation representing the only distinctive feature.

CONCLUSIONS

Based on our results, syphilis should be included in the differential diagnosis of increased liver enzymes in HIV-infected patients.

Talin, vinculin and nestin expression in orofacial muscles of dystrophin deficient mdx mice

The activity of cytoskeletal proteins like talin, vinculin and nestin increases in muscle that regenerates. Little is known about their role or at least their expression in the process of regeneration in masticatory muscles of mdx mice, a model of Duchenne muscular dystrophy. To determine a potential role of cytoskeletal proteins in the regeneration process of mdx masticatory muscles, we examined the expression of talin 1, talin 2, vinculin and nestin in 100-day-old control and mdx mice using quantitative RT-PCR, Western blot analyses and histochemistry. The protein expression of talin 1, talin 2, nestin and vinculin in mdx muscles remained unchanged as compared with normal mice. However, in mdx masseter it was found a relative increase of nestin compared to controls. The protein expression of talin 1 and vinculin tended to be increased in mdx tongue and talin 2 to diminish in mdx masseter and temporal muscle. In mdx mice, we found significantly lower percentage of transcripts coding for nestin, talin 1, talin 2 and vinculin in masseter (p < 0.05) and temporal muscle (p < 0.001). In contrast, the mRNA expression of nestin was found to be increased in mdx tongue. Activated satellite cells, myoblasts and immature regenerated muscle fibres in mdx masseter and temporal revealed positive staining for nestin. The findings of the presented work suggest dystrophin-lack-associated changes in the expression of cytoskeletal proteins in mdx masticatory muscles could be compensatory for dystrophin absence. The expression of nestin may serve as an indicator for the regeneration in the orofacial muscles.

Long-term beneficial effect of protease inhibitors on the intrinsic apoptosis of peripheral blood mononuclear cells in HIV-infected patients

BACKGROUND

Viral suppression by antiretroviral therapy (ART) inhibits HIV-induced apoptosis and CD4 T-cell loss. It has been suggested that protease inhibitors (PIs) have nonviral antiapoptotic effects by maintaining mitochondrial integrity. Long-term clinical effects of PI-based ART on mitochondrial toxicity and lymphocyte apoptosis beyond viral suppression have not been exploited to date.

METHODS

We conducted a 7-year study on HIV-1-infected patients from the Cologne HIV cohort with sufficient viral suppression under either a PI-based or nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen. Eight patients on PI and eight on NNRTI were eligible for inclusion in the analysis. The primary outcome measure was defined as a change in the mitochondrial-to-nuclear DNA ratio in PBMCs. Further key molecules involved in extrinsic [tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), Fas ligand (FasL) and caspase 8], intrinsic [B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), caspase 9 and lactate-to-pyruvate ratio] and overall apoptosis [Annexin+/7-aminoactinomycin D (7-AAD)- and caspase 3/7] and viral activity [negative regulatory factor (Nef), interferon-α (IFN-α) and myxovirus resistance protein A (MxA)] were measured.

RESULTS

Demographic and baseline clinical parameters were similar in the two groups, except that patients in the PI group had a higher mean age. After 7 years of treatment, CD4 T-cell count increased and the expression of genes encoding the proapoptotic viral protein Nef and HIV-induced cytokine IFN-α and its downstream effector MxA decreased in both groups. Focusing on the different pathways of apoptosis, only in the PI group intrinsic apoptosis decreased significant and in the inter-group comparison the decrease was significantly higher than in the NNRTI group.

CONCLUSIONS

Our study provides evidence that long-term therapy with a PI-based regimen may be superior to that with a NNRTI-based regimen with regard to its intrinsic antiapoptotic effect.

Activated protein C improves pial microcirculation in experimental endotoxemia in rats

INTRODUCTION

The brain is one of the first organs affected clinically in sepsis. Microcirculatory alterations are suggested to be a critical component in the pathophysiology of sepsis. The aim of this study was to investigate the effects of recombinant human activated protein C (rhAPC) on the pial microcirculation in experimental endotoxemia using intravital microscopy. Our hypothesis is rhAPC protects pial microcirculation in endotoxemia.

METHODS

Endotoxemia was generated in Lewis rats with intravenous injection of lipopolysaccharide (LPS, 5 mg/kg i.v.). Dura mater was removed through a cranial window to expose pial vessels on the brain surface. The microcirculation, including leukocyte-endothelial interaction, functional capillary density (FCD) and plasma extravasation of pial vessels was examined by fluorescent intravital microscopy (IVM) 2 h after administration of LPS, LPS and rhAPC or equivalent amount of saline (used as Control group). Plasma cytokine levels of interleukin 1 alpha (IL1-α), tumor necrosis factor-α (TNF-α), interferon γ (IFN-γ), Monocyte chemotactic protein-1 (MCP-1) and Granulocyte-macrophage colony-stimulating factor (GM-CSF) were evaluated after IVM.

RESULTS

LPS challenge significantly increased leukocyte adhesion (773±190 vs. 592±152 n/mm(2) Control), decreased FCD (218±54 vs. 418±74 cm/cm(2) Control) and increased proinflammatory cytokine levels (IL-1α: 5032±1502 vs. 8±21 pg/ml; TNF-α: 1823±1007 vs. 168±228 pg/ml; IFN-γ: 785±434 vs. 0 pg/ml; GM-CSF: 54±52 vs. 1±3 pg/ml) compared to control animals. rhAPC treatment significantly reduced leukocyte adhesion (599±111 n/mm(2)), increased FCD (516±118 cm/cm(2)) and reduced IL-1α levels (2134±937 pg/ml) in the endotoxemic rats.

CONCLUSION

APC treatment significantly improves pial microcirculation by reducing leukocyte adhesion and increasing FCD.

Continuous versus intermittent stochastic resonance whole body vibration and its effect on pelvic floor muscle activity

AIMS

To determine the optimal stochastic whole body vibration (SR-WBV) load modality regarding pelvic floor muscle (PFM) activity in order to complete the SR-WBV training methodology for future PFM training with SR-WBV.

METHODS

The continuous and the intermittent SR-WBV modalities were tested by means of electromyography in two independent groups (27 women 8 weeks to 1-year postpartum and 23 women nulliparae or >1-year postpartum) with self-reported stress urinary incontinence. The change in the PFM activity within a single set and over three sets were calculated for both SR-WBV modalities together (time effect) and for both SR-WBV modalities separately (modality-time interaction).

RESULTS

There was no statistically significant or clinically relevant change in PFM activity over time or PFM fatigue in either SR-WBV modality within one or three sets and no difference between the modalities or the groups.

CONCLUSIONS

The lack of change in PFM activity could be due to a no more than moderate to submaximal PFM activity during SR-WBV, the maintenance of reflexive PFM activity despite PFM fatigue or a compensation of slow red PFM fiber fatigue by an increase of innervation frequency and motor unit recruitment of the fast white fibers. As there is no SR-WBV modality dependent difference regarding PFM activity, the continuous modality is recommended in clinical practice as it is easier to apply and less time consuming.

Photoelectron spectromicroscopy at chalcopyrite films

CuInSe₂ films were prepared by MBE on GaAs (111) substrates. ZnSe and ZnO are subsequently deposited in situ by MOMBE. Interface parameters like band offsets and morphology are studied by X-ray photoelectron spectroscopy (XPS) and Low energy electron diffraction (LEED). Spectroscopic XPEEM (X-ray photoelectron emission microscopy) at the U49/2 PGM2 beamline at BESSY was used to investigate the lateral homogenity of the interface. After annealing in situ a lateral inhomogenious In diffusion is observed into the ZnSe/ZnO interface.

Dependency of the regio- and stereoselectivity of intramolecular, ring-closing glycosylations upon the ring size

Phenyl 3,4,6-tri-O-benzyl-2-O-(3-carboxypropionyl)-1-thio-β-D-galactopyranoside (1) was condensed via its pentafluorophenyl ester 2 with 5-aminopentyl (4a), 4-aminobutyl (4b), 3-aminopropyl (4c) and 2-aminoethyl 4,6-O-benzylidene-β-D-glucopyranoside (4d), prepared from the corresponding N-Cbz protected glucosides 3a–d, to give the corresponding 2-[3-(alkylcarbamoyl)propionyl] tethered saccharides 5a–d. Intramolecular, ring closing glycosylation of the saccharides with NIS and TMSOTf afforded the tethered β(1→3) linked disaccharides 6a–c, the α(1→3) linked disaccharides 7a–d and the α(1→2) linked disaccharide 8d in ratios depending upon the ring size formed during glycosylation. No β(1→2) linked disaccharides were formed. Molecular modeling of saccharides 6–8 revealed that a strong aromatic stacking interaction between the aromatic parts of the benzyl and benzylidene protecting groups in the galactosyl and glucosyl moieties was mainly responsible for the observed regioselectivity and anomeric selectivity of the ring-closing glycosylation step.