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2.
J Cancer Res Clin Oncol ; 149(18): 16575-16587, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37715831

ABSTRACT

BACKGROUND: Cancer patients often use complementary and alternative medicine (CAM), however, standardized assessment in clinical routine is missing. The aim of this study was to evaluate a screening questionnaire on CAM usage that was published in the S3 Guideline Complementary Medicine in the Treatment of Oncological Patients. METHODS: We developed a survey questionnaire to assess the practicability of the guideline questionnaire and communication on CAM between health care providers (HCPs) and patients. We collected 258 guideline questionnaires and 116 survey questionnaires from ten clinics and held twelve semi-structured interviews with HCPs. RESULTS: 85% used at least one of the listed CAM methods, 54 participants (N = 77) never disclosed usage to a physician. The most frequently used CAM methods were physical activity (76.4%) and vitamin D (46.4%). 25.2% used at least one method, that was labeled risky by the guideline. 53.4% did not know of CAM's risk of interactions and side effects. Introducing the guideline questionnaire in routine cancer care increased the rate of patients talking to an HCP regarding CAM significantly from 35.5 to 87.3%. The HCPs stated positive effects as an initiation of conversation, increased safety within CAM usage and patients feeling thankful and taken seriously. However, due to the limited amount of time available for discussions on CAM, generalized distribution to all patients was not feasible. CONCLUSION: Institutions should focus on implementing standard procedures and resources that help HCPs discuss CAM on a regular basis. HCPs should meet the patient's demands for CAM counseling and make sure they are equipped professionally.


Subject(s)
Complementary Therapies , Neoplasms , Physicians , Humans , Physicians/psychology , Surveys and Questionnaires , Health Personnel , Neoplasms/therapy
4.
Mob DNA ; 9: 16, 2018.
Article in English | MEDLINE | ID: mdl-29745378

ABSTRACT

[This corrects the article DOI: 10.1186/s13100-018-0116-5.].

5.
Ann Oncol ; 28(8): 1756-1766, 2017 Aug 01.
Article in English | MEDLINE | ID: mdl-28444111

ABSTRACT

Durable tumor responses and significant levels of disease control rates have been described in more than 20 advanced/metastatic cancer types with B7-family immune checkpoint-targeted anti-CTLA-4, anti-PD-1, and anti-PD-L1 monoclonal antibodies. These results and the recent approvals of ipilimumab, pembrolizumab, nivolumab and atezolizumab are currently revolutionizing the way we envision the future of cancer care. However these clinical benefits are not observed in all cancer types and in every patient. Therefore, our clinical challenge is to identify therapeutic strategies which could overcome the primary and secondary resistances to these novel cancer immunotherapies. Pattern recognition receptors (PRRs) are other critical costimulatory molecules of immune cells, notably myeloid cells (macrophages and dendritic cells). They were initially described as sensors for 'danger signals' released by pathogens (e.g. viral DNA and bacterial proteins). We know now that PRRs can also be recruited and activated upon recognition of endogenous stress signals such as molecules released upon self-cell death (e.g. ATP and HMGB1). Natural endo/exogenous or synthetic PRRs agonists have notably the ability to activate phagocytosis and antigen presentation by myeloid cells residing in the tumor micro-environment. In pre-clinical models, these PRRs agonists have also been shown to overcome the resistance to T-cell targeted immune checkpoints anti-CTLA-4 and anti-PD-1/PD-L1. This manuscript reviews the current knowledge on this major family of immune receptors and the molecules targeting them which are currently in clinical development.


Subject(s)
Immunotherapy , Neoplasms/therapy , Receptors, Pattern Recognition/agonists , Humans , Neoplasms/immunology
6.
Anaesthesist ; 64(9): 683-8, 2015 Sep.
Article in German | MEDLINE | ID: mdl-26275386

ABSTRACT

Baroreceptor stimulators are novel implantable devices that activate the carotid baroreceptor reflex. This results in a decrease in activity of the sympathetic nervous system and inhibition of the renin-angiotensin-aldosterone system. In patients with drug-resistant hypertension, permanent electrical activation of the baroreceptor reflex results in blood pressure reduction and cardiac remodeling. For correct intraoperative electrode placement at the carotid bifurcation, the baroreceptor reflex needs to be activated several times. Many common anesthetic agents, such as inhalation anesthetics and propofol dampen or inhibit the baroreceptor reflex and complicate or even prevent successful placement. Therefore, a specific anesthesia and pharmacological management is necessary to ensure successful implantation of baroreceptor reflex stimulators.


Subject(s)
Electrodes, Implanted , Pressoreceptors , Prosthesis Implantation/methods , Anesthesia , Baroreflex , Electric Stimulation Therapy , Humans
7.
Adv Hematol ; 2012: 683065, 2012.
Article in English | MEDLINE | ID: mdl-22272203

ABSTRACT

Genetic engineering of T cells with chimeric T-cell receptors (CARs) is an attractive strategy to treat malignancies. It extends the range of antigens for adoptive T-cell immunotherapy, and major mechanisms of tumor escape are bypassed. With this strategy we redirected immune responses towards the CD33 antigen to target acute myeloid leukemia. To improve in vivo T-cell persistence, we modified human Epstein Barr Virus-(EBV-) specific cytotoxic T cells with an anti-CD33.CAR. Genetically modified T cells displayed EBV and HLA-unrestricted CD33 bispecificity in vitro. In addition, though showing a myeloablative activity, they did not irreversibly impair the clonogenic potential of normal CD34(+) hematopoietic progenitors. Moreover, after intravenous administration into CD33(+) human acute myeloid leukemia-bearing NOD-SCID mice, anti-CD33-EBV-specific T cells reached the tumor sites exerting antitumor activity in vivo. In conclusion, targeting CD33 by CAR-modified EBV-specific T cells may provide additional therapeutic benefit to AML patients as compared to conventional chemotherapy or transplantation regimens alone.

8.
Cell Death Differ ; 18(2): 271-81, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20689556

ABSTRACT

A mutation within one allele of the p53 tumor suppressor gene can inactivate the remaining wild-type allele in a dominant-negative manner and in some cases can exert an additional oncogenic activity, known as mutant p53 'gain of function' (GOF). To study the role of p53 mutations in prostate cancer and to discriminate between the dominant-negative effect and the GOF activity of mutant p53, we measured, using microarrays, the expression profiles of three immortalized prostate epithelial cultures expressing wild-type, inactivated p53 or mutated p53. Analysis of these gene expression profiles showed that both inactivated p53 and p53(R175H) mutant expression resulted in the upregulation of cell cycle progression genes. A second group, which was upregulated exclusively by mutant p53(R175H), was predominantly enriched in developmental genes. This group of genes included the Twist1, a regulator of metastasis and epithelial-mesenchymal transition (EMT). Twist1 levels were also elevated in metastatic prostate cancer-derived cell line DU145, in immortalized lung fibroblasts and in a subset of lung cancer samples, all in a mutant p53-dependent manner. p53(R175H) mutant bearing immortalized epithelial cells showed typical features of EMT, such as higher expression of mesenchymal markers, lower expression of epithelial markers and enhanced invasive properties in vitro. The mechanism by which p53(R175H) mutant induces Twist1 expression involves alleviation of the epigenetic repression. Our data suggest that Twist1 expression might be upregulated following p53 mutation in cancer cells.


Subject(s)
Epithelial-Mesenchymal Transition , Nuclear Proteins/metabolism , Prostatic Neoplasms/metabolism , Tumor Suppressor Protein p53/metabolism , Twist-Related Protein 1/metabolism , Amino Acid Substitution , Cell Line, Transformed , Cell Line, Tumor , Epigenesis, Genetic , Histones/metabolism , Humans , Male , Mutation , Nuclear Proteins/genetics , Polycomb Repressive Complex 1 , Promoter Regions, Genetic , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Proto-Oncogene Proteins/metabolism , Repressor Proteins/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/physiology , Twist-Related Protein 1/genetics , Up-Regulation
9.
Anaesthesist ; 59(11): 1008-12, 2010 Nov.
Article in German | MEDLINE | ID: mdl-20827452

ABSTRACT

The use of extracorporeal membrane oxygenation (ECMO) was established in Germany 25 years ago in specialized centers as an approach for patients suffering from severe life-threatening lung failure. Apart from such indications the inclusion of ECMO as a planned intervention for safety purposes in the postoperative weaning from mechanical ventilation in a 22-year-old woman is described. Following a complex tracheal reconstruction due to oesophageal-tracheal fistula formation, conventional weaning procedures would have been accompanied by a very high risk as extubation failure might have caused an airway disaster. After elective use of veno-venous ECMO the young patient was extubated without risk and lung function was stabilized safely. Extracorporeal lung assist can be indicated apart from rescue management in elective situations for prevention of an airway catastrophe after careful calculation of the harm/benefit ratio.


Subject(s)
Extracorporeal Membrane Oxygenation , Intraoperative Complications/prevention & control , Respiratory Distress Syndrome/prevention & control , Blood Gas Analysis , Female , Humans , Patient Care Planning , Postoperative Care , Postoperative Complications/prevention & control , Respiration, Artificial , Risk Assessment , Tomography, X-Ray Computed , Trachea/surgery , Tracheoesophageal Fistula/surgery , Ventilator Weaning , Young Adult
10.
Oncogene ; 27(6): 783-93, 2008 Jan 31.
Article in English | MEDLINE | ID: mdl-17637740

ABSTRACT

Apoptosis resistance is crucially involved in cancer development and progression, represents the leading cause for failure of anticancer therapy and is caused, for example, by downregulation of proapoptotic intracellular signaling molecules such as caspase-8. We found that the cytotoxic drugs methotrexate (MTX) and 5-fluorouracil (5-FU) were both able to sensitize resistant tumor cells for induction of apoptosis by p53-mediated upregulation of caspase-8. Increase in caspase-8 messenger RNA and protein expression disabled tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced proliferation and restored sensitivity toward TRAIL-induced apoptosis which was inhibited by transfection of p53 decoy oligonucleotides, p53 shRNA and caspase-8 shRNA. Upregulation of caspase-8 and sensitization toward TRAIL-induced apoptosis was found both in a broad panel of tumor cell lines with downregulated caspase-8 and in TRAIL-resistant primary tumor cells of children with acute leukemia. Taken together, we have identified caspase-8 as an important p53 target gene regulated by cytotoxic drugs. These findings highlight a new drug-induced modulation of physiological apoptosis pathways, which may be involved in successful anticancer therapy using MTX and 5-FU in leukemia and solid tumors over decades.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Caspase 8/metabolism , Drug Resistance, Neoplasm , Fluorouracil/pharmacology , Methotrexate/pharmacology , Tumor Suppressor Protein p53/metabolism , Caspase 8/genetics , Caspase Inhibitors , Cell Line, Tumor , Humans , RNA, Messenger/metabolism , TNF-Related Apoptosis-Inducing Ligand/pharmacology , Tumor Suppressor Protein p53/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics , Up-Regulation
11.
Eur J Anaesthesiol ; 23(11): 948-53, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16780613

ABSTRACT

BACKGROUND AND OBJECTIVE: Propofol has been shown to inhibit a variety of functions of neutrophils in vitro, but there is a lack of in vivo data. To analyse the effects of propofol on neutrophil function in vivo we chose to investigate cataract surgery since it represents a small surgical procedure with minimal immunomodulatory effects induced by surgery. We sought to analyse any immunosuppressive effects of propofol after short-term administration in vivo in comparison to local anaesthesia as well as to in vitro effects of propofol. METHODS: The study was designed as an open randomized trial enrolling 20 patients undergoing general or local anaesthesia. The neutrophil oxidative response and propofol plasma concentration were assessed prior, during and after anaesthesia. Neutrophil function was determined flow cytometrically based on dihydrorhodamine 123 oxidation. RESULTS: Propofol concentrations which yielded a marked suppression in vitro did not alter the neutrophil oxidative response during cataract surgery in vivo. However, after local anaesthesia the neutrophil oxidative response declined to 37%, compared to the control response prior to anaesthesia. CONCLUSIONS: Although we could detect the well established suppression of neutrophil function by propofol in vitro it was not evident in vivo. This may be due to compensating effects on neutrophil function during surgery in vivo. The decline in the neutrophil oxidative response in the local anaesthesia group might be due to increased stress and catecholamine concentrations or a direct interaction of local anaesthetics with neutrophil intracellular signalling.


Subject(s)
Anesthetics, Intravenous/pharmacology , Neutrophils/drug effects , Propofol/pharmacology , Respiratory Burst/drug effects , Adult , Aged , Analysis of Variance , Anesthesia, General , Anesthesia, Local , Anesthetics, Intravenous/blood , Cataract Extraction , Female , Humans , Hydrogen Peroxide/metabolism , Male , Middle Aged , Neutrophils/metabolism , Propofol/blood
12.
Int J Cancer ; 118(8): 1954-62, 2006 Apr 15.
Article in English | MEDLINE | ID: mdl-16287080

ABSTRACT

Wilms tumor is the most frequent renal neoplasm in children, but our understanding of its genetic basis is still limited. We performed cDNA microarray experiments using 63 primary Wilms tumors with the aim of detecting new candidate genes associated with malignancy grade and tumor progression. All tumors had received preoperative chemotherapy as mandated by the SIOP protocol, which sets this study apart from related approaches in the Unites States that are based on untreated samples. The stratification of expression data according to clinical criteria allowed a rather clear distinction between different subsets of Wilms tumors. Clear-cut differences in expression patterns were discovered between relapse-free as opposed to relapsed tumors and tumors with intermediate risk as opposed to high risk histology. Several differentially expressed genes, e.g.TRIM22, CENPF, MYCN, CTGF, RARRES3 and EZH2, were associated with Wilms tumor progression. For a subset of differentially expressed genes, microarray data were confirmed by real-time RT-PCR on the original set of tumors. Interestingly, we found the retinoic acid pathway to be deregulated at different levels in advanced tumors suggesting that treatment of these tumors with retinoic acid may represent a promising novel therapeutic approach.


Subject(s)
Gene Expression Profiling , Kidney Neoplasms/genetics , Kidney Neoplasms/pathology , Wilms Tumor/genetics , Wilms Tumor/pathology , Disease Progression , Humans , Oligonucleotide Array Sequence Analysis , Prognosis , Reverse Transcriptase Polymerase Chain Reaction , Survival Analysis , Tretinoin/physiology
13.
Br J Cancer ; 94(1): 13-7, 2006 Jan 16.
Article in English | MEDLINE | ID: mdl-16306876

ABSTRACT

A major obstacle to the expansion of abnormal cells with significant proliferative potential is the induction of programmed cell death. Consequently, oncogene-driven hyperproliferation must be associated with apoptosis inhibition to allow malignant outgrowth. The oncogenic cooperation of N-Myc and Twist-1 in the development of neuroblastoma, the most common and deadly solid tumour of childhood, perfectly illustrates such a process. N-Myc promotes cell proliferation, whereas Twist-1 counteracts its pro-apoptotic properties by knocking-down the ARF/p53 pathway. On the basis of numerous recent studies reporting its overexpression in a variety of human cancers, we discuss in this review the role of Twist-1 as a potent inhibitor of the cell safety programs engaged in response to an abnormal mitogenic activity.


Subject(s)
Apoptosis , Breast Neoplasms/physiopathology , Neuroblastoma/physiopathology , Cell Proliferation , Disease Progression , Humans , Neoplasm Metastasis , Nuclear Proteins , Proto-Oncogene Proteins c-myc/physiology , Survival , Twist-Related Protein 1
14.
Neuroimmunomodulation ; 12(3): 152-6, 2005.
Article in English | MEDLINE | ID: mdl-15905623

ABSTRACT

OBJECTIVES: To investigate the effect of cerebrospinal fluid (CSF) from patients with subarachnoid hemorrhage (SAH) on the activation of polymorphonuclear neutrophils (PMN) in response to receptor-dependent stimulation with N-formyl-l-methionyl-l-leucyl-l-phenylalanine and TNFalpha or non-receptor-dependent stimulation with phorbol 12-myristate 13-acetate. METHODS: CSF from 12 patients with SAH due to ruptured cerebral aneurysm was collected. Samples of CSF were drawn at different time points. CSF from 6 healthy subjects receiving spinal anesthesia served as the control group. After stimulation of PMN the generation of reactive oxygen intermediates was analyzed on a flow cytometer. RESULTS: In the presence of CSF, PMN showed a significant suppression of the oxidative burst following stimulation compared to stimulation without CSF. The reduction of the oxidative burst following stimulation was higher in the presence of CSF from patients with SAH. After pretreatment at 56 degrees C, the extent of the suppression observed following receptor-dependent stimulation and CSF from patients with SAH was similar to that seen after stimulation with CSF from healthy individuals. CONCLUSIONS: These data show that the presence of CSF resulted in a suppression of neutrophil oxidative function. A more distinct depression was seen in the presence of CSF from patients with SAH. We suggest a complex physiological inhibitory and protective mechanism against unfavorable activation of PMN by CSF.


Subject(s)
Chemotaxis, Leukocyte/immunology , Immune Tolerance/immunology , Neutrophils/metabolism , Respiratory Burst/immunology , Subarachnoid Hemorrhage/cerebrospinal fluid , Subarachnoid Hemorrhage/immunology , Adult , Aged , Cerebrospinal Fluid Proteins/immunology , Cerebrospinal Fluid Proteins/metabolism , Cerebrospinal Fluid Proteins/pharmacology , Chemotaxis, Leukocyte/drug effects , Female , Free Radicals/metabolism , Humans , Immune Tolerance/drug effects , Male , Middle Aged , N-Formylmethionine Leucyl-Phenylalanine/pharmacology , Neutrophils/drug effects , Neutrophils/immunology , Reference Values , Respiratory Burst/drug effects , Subarachnoid Hemorrhage/physiopathology , Tetradecanoylphorbol Acetate/pharmacology , Tumor Necrosis Factor-alpha/pharmacology
15.
Pharmacology ; 72(1): 12-9, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15292650

ABSTRACT

To elucidate potential stereoselective effects of single barbiturate isomers, we compared the inhibitory potency of single thiopentone enantiomers, two isomer-enriched mixtures of methohexitone and racemic mixtures of both barbiturates on the fMLP-induced neutrophil oxidative response. A suppression of the response to 50% compared to control required a 100-fold therapeutic concentration of methohexitone, while therapeutic concentrations of the thiopentone racemate led to a significant inhibition (relative fluorescence of neutrophils 0.46 +/- 0.03 compared to fMLP controls). The racemate of thiopentone produced significantly greater inhibition than the single enantiomers. Stereoselectivity in favor of one isomer could not be shown for both barbiturates. The greater inhibition by the thiopentone racemate might suggest two separate binding sites for the enantiomers which are positively coupled.


Subject(s)
Anesthetics, Intravenous/pharmacology , Methohexital/pharmacology , N-Formylmethionine Leucyl-Phenylalanine/antagonists & inhibitors , Neutrophils/drug effects , Thiopental/pharmacology , Adult , Humans , Hydrogen Peroxide/metabolism , N-Formylmethionine Leucyl-Phenylalanine/pharmacology , Neutrophils/metabolism , Oxidation-Reduction/drug effects , Stereoisomerism
16.
Cytometry A ; 57(1): 53-62, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14699606

ABSTRACT

BACKGROUND: Neutrophil activation is strongly related to organ dysfunction that occurs during systemic inflammatory responses. The aim of our study was to analyze the oxidative burst response in correlation to the up- and downregulation of N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) receptors and the surface antigens CD11b, CD62L, and CD66b as potential surrogate markers of the degree of neutrophil priming for an increased oxidative burst response induced by proinflammatory cytokines. METHODS: Blood was taken from healthy donors. Neutrophils were pretreated with cytokines (interleukin [IL]-1beta, IL-6, IL-8, granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNFalpha]; 0.01-10 ng/ml) and stimulated with fMLP (100 nM) in vitro. Functional and phenotypical parameters were quantified flow cytometrically. RESULTS: The oxidative burst response increased after priming with 0.1 ng/ml TNFalpha, 1 ng/ml GM-CSF, or 10 ng/ml IL-8. Upregulation of fMLP receptors, CD11b, and CD66b and downregulation of CD62L showed a close correlation to the oxidative burst response. Altered expression of these parameters partly reached significance at lower cytokine concentrations in comparison with the oxidative burst. IL-1beta and IL-6 had no effect. CONCLUSIONS: Our results showed that the expression of phenotypical parameters closely correlates with functional parameters in human neutrophils. Thus an up- or downregulation of antigens such as CD11b or CD62L reflects cytokine-induced functional changes.


Subject(s)
Antigens, Surface/metabolism , Cytokines/pharmacology , Neutrophil Activation/drug effects , Neutrophils/drug effects , Respiratory Burst/drug effects , Up-Regulation , Adult , Cells, Cultured , Dose-Response Relationship, Drug , Humans , N-Formylmethionine Leucyl-Phenylalanine/pharmacology , Neutrophil Activation/physiology , Neutrophils/metabolism , Receptors, Formyl Peptide/metabolism , Respiratory Burst/physiology , Sensitivity and Specificity
17.
J Dairy Sci ; 86(2): 538-45, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12647960

ABSTRACT

Cytokines, eicosanoids, and lactoferrin are involved in the mammary gland's immune response to invading microorganisms. The goal of this work was to investigate the synthesis of these immunologically important factors in somatic milk cells, blood cells, and mammary tissue of cows with different somatic cell count levels, i.e., different immunological activity. On the level of mRNA expression, the cytokine tumor necrosis factor alpha (TNFalpha), lactoferrin (Lf), and specific key enzymes of leukotriene and prostaglandin biosynthesis, 5-lipoxygenase (5-LO), and cyclooxygenase-1 (COX-1) and -2 (COX-2), respectively, were determined. All 15 experimental cows were clinically healthy with no visible mammary disease. Eight cows were defined as control group with all quarters <150,000 cells/ml (C), whereas seven cows had partially elevated quarter somatic cell counts, with at least one quarter >150,000 cells/ml (H) and one quarter <150,000 cells/ml (L). Total quarter milk from one quarter of control group and from two quarters of cows with partially elevated cell counts (one of H and one of L) was collected at one milking and a blood sample was taken simultaneously. In addition, mammary tissue samples were taken from the respective quarters on the following day during slaughter. Total RNA from milk, blood, and tissue cells was isolated and reverse transcription and quantitative polymerase chain reaction was carried out. All factors investigated were not significantly different between groups in blood cells and between C and L quarters in milk cells and mammary tissue. TNFalpha and COX-2 mRNA expression was higher in milk cells and mammary tissue of H than in L quarters, except for COX-2 in mammary tissue. Generally, TNFalpha and COX-2 showed their highest expression in milk cells, 5-LO in blood cells, whereas lactoferrin was mainly expressed by the mammary tissue. COX-1 was similarly expressed in all tested samples.


Subject(s)
Blood Cells/immunology , Cattle/genetics , Cattle/immunology , Gene Expression , Mammary Glands, Animal/immunology , Milk/immunology , Animals , Arachidonate 5-Lipoxygenase/genetics , Bacteria/isolation & purification , Cell Count , Cyclooxygenase 1 , Cyclooxygenase 2 , Female , Isoenzymes/genetics , Lactoferrin/genetics , Milk/cytology , Milk/microbiology , Prostaglandin-Endoperoxide Synthases/genetics , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , Staphylococcus/isolation & purification , Streptococcus/isolation & purification , Tumor Necrosis Factor-alpha/genetics , Ubiquitin/genetics
18.
Eur J Anaesthesiol ; 19(7): 474-82, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12113609

ABSTRACT

BACKGROUND AND OBJECTIVE: Thiopental in clinically relevant concentrations inhibits the oxidative function of neutrophils, whereas only very high, non-therapeutic concentrations of methohexital induce a similar effect. The study characterized the molecular basis of this differential action of oxy- and thiobarbiturates on neutrophils. METHODS: Neutrophils were incubated in vitro with thiopental or methohexital using concentrations within the therapeutic range. Neutrophil responses were induced using different stimuli: N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP), C5a and 1,2-dioctanoyl-sn-glycerol (DiC8-DAG). FMLP and C5a bind to specific G-protein-coupled receptors that share the same second messenger cascade. In contrast, DiC8-DAG, an activator of protein kinase C, bypasses the signal transduction pathway downstream of the receptors. Hydrogen peroxide production by neutrophils was assessed using flow cytometry. To characterize the localization of the interaction site, FMLP receptor expression and cytosolic-free calcium were further analysed. RESULTS: FMLP and C5a-induced hydrogen peroxide production were both significantly impaired by thiopental, but not by methohexital. When postreceptor signalling was bypassed, by stimulation with DiC8-DAG, neither thiopental nor methohexital affected hydrogen peroxide production. Additionally, neither of the barbiturates impaired the cytosolic Ca2+ response. CONCLUSIONS: We conclude that neither protein kinase C nor the hydrogen peroxide-generating enzymes are affected by thiopental or methohexital. The unimpaired Ca2+ response suggests that the function of the receptors and G-proteins were also unimpaired. Taken together, this indicates that the site of action of thiopental is in the cellular signalling upstream of protein kinase C.


Subject(s)
Anesthetics, Intravenous/pharmacology , Neutrophils/drug effects , Respiratory Burst/drug effects , Signal Transduction/drug effects , Thiopental/pharmacology , Flow Cytometry , Humans , Hydrogen Peroxide/metabolism , In Vitro Techniques , Methohexital/pharmacology
19.
Bioorg Med Chem ; 10(6): 1659-70, 2002 Jun.
Article in English | MEDLINE | ID: mdl-11937324

ABSTRACT

Linking of siderophores to antibiotics improves the penetration and therefore increases the antibacterial activity of the antibiotics. We synthesized the acylated catecholates and hydroxamates as siderophore components for antibiotic conjugates to reduce side effects of unprotected catecholate and hydroxamate moieties. In this paper, we report on bis- and tris-catecholates and mixed catecholate hydroxamates based on diamino acids or dipeptides. These compounds were active as siderophores in a growth promotion assay under iron limitation. Most of the conjugates with beta-lactams showed high in vitro activity against Gram-negative bacteria especially Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Serratia marcescens and Stenotrophomonas maltophilia. The compounds with enhanced antibacterial activity use active iron uptake routes to penetrate the bacterial outer membrane barrier, demonstrated by assays with mutants deficient in components of the iron transport system. Correlation between chemical structure and biological activity was studied.


Subject(s)
Amino Acids, Diamino/chemistry , Dipeptides/chemistry , Siderophores/chemistry , beta-Lactams/chemistry , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Catechols/chemical synthesis , Catechols/chemistry , Catechols/pharmacology , Cell Division/drug effects , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/growth & development , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/growth & development , Hydroxamic Acids/chemistry , Hydroxamic Acids/pharmacology , Microbial Sensitivity Tests , Molecular Structure , Siderophores/chemical synthesis , Siderophores/pharmacology , Structure-Activity Relationship , beta-Lactams/chemical synthesis , beta-Lactams/pharmacology
20.
J Virol ; 75(18): 8478-86, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11507193

ABSTRACT

We have previously reported a set of Moloney murine leukemia virus derived envelopes retargeted to the Pit-2 phosphate transporter molecule, by insertion of the Pit-2 binding domain (BD) at the N terminus of the ecotropic retroviral envelope glycoproteins (S. Valsesia-Wittmann et al., J. Virol. 70:2059-2064, 1996). The resulting chimeric envelopes share two BDs: an additional N-terminal BD (Pit-2 BD) and the BD of the ecotropic envelope (mCAT-1 BD). By inserting a variety of different amino acid spacers between the two binding domains, we showed that retroviruses can potentially use the targeted cell surface receptor Pit-2, the ecotropic retroviral receptor mCAT-1, or both receptors cooperatively for entry into target cell (S. Valsesia-Wittmann et al., EMBO J 6:1214-1223, 1997). An extreme example of receptor cooperativity was encountered when envelopes with specific proline-rich interdomain spacers (PRO spacers) were tested: both receptors had to be coexpressed at the surface of the targeted cells to cooperatively allow infection. Here, we characterized the role of PRO spacer in the cooperation of receptors. We have shown that the particular organization of the PRO spacer-a beta-turn polyproline-was responsible for the cooperative effect. In the native configuration of the viruses, the structure masked the regions located downstream of the PRO spacer, thus the mCAT-1 BD. After interaction with the targeted Pit-2 receptor, the BD of the backbone envelope became accessible, and we demonstrated that interaction between the mCAT-1 BD and the mCAT-1 receptor is absolutely necessary. This interaction leads to natural fusion triggering and entry of viruses into targeted cells.


Subject(s)
Carrier Proteins/metabolism , Gene Products, env/metabolism , Leukemia Virus, Murine/metabolism , Membrane Glycoproteins/metabolism , Receptors, Virus/metabolism , Symporters , 3T3 Cells , Amino Acid Sequence , Animals , CHO Cells , Carrier Proteins/genetics , Cell Line , Cricetinae , Gene Products, env/genetics , Humans , Membrane Fusion , Membrane Glycoproteins/genetics , Mice , Molecular Sequence Data , Mutagenesis , Proline/genetics , Receptors, Virus/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Sodium-Phosphate Cotransporter Proteins , Sodium-Phosphate Cotransporter Proteins, Type III
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