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Target Molecules (target + molecule)
Selected AbstractsPermanganate Oxidation Revisited: Synthesis of 3-Deoxy-2-uloses via Indium-Mediated Chain Elongation of CarbohydratesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 25 2010Christoph Schmölzer Abstract Application of the Barbier-type indium-mediated allylation method to suitable substrates offers access to carbohydrates bearing a terminal olefin moiety. The C,C bond forming reaction generates a defined stereochemistry of the new chiral center and tolerates a wide variety of starting aldehydes thus allowing modifications in the carbohydrate backbone. Further transformations of the alkene moiety via an environmentally benign and subtle controlled protocol using potassium permanganate gives rise to the structural motif of 3-deoxy-2-uloses in good yields. The final part of the reaction sequence focuses on the deprotection of the acetyl groups essential for the success of the oxidation step. The acidic and labile 3-deoxy position of the target molecule is prone to elimination applying standard deacetylation conditions and therefore demands derivatisation of the molecule. The introduction of a thioketal moiety using microwave conditions shows promising results and subsequent standard transformations are applicable leading to the desired products. [source] On the Way to Glycoprocessing Inhibitors , Synthesis of an Imidazolo-Nectrisine-Phosphono Acid Derivative: A Potential Glycosyltranferase InhibitorEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 15 2003Théophile Tschamber Abstract Assuming the transition state of glycosyltransferase inhibitors to be similar to those encountered with potent glycosidase inhibitors , i.e. a flattened conformation with a positively charged anomeric centre , we worked out a synthesis of the D - arabino -configured phosphonic acid target molecule 2 derived from an imidazolo-sugar. The key synthetic intermediate is the linear imidazolo L - xylo compound 10 which could be obtained, either from L - threo precursor 6 by a coupling reaction with imidazole derivative 5, or from L -sorbose. A multi-step and site specific iodination of 10 gave the mono-iodo- L - xylo derivative 14 which was cyclised to the D - arabino -configured bicyclic azasugar 15. Phosphorylation of the Grignard derivative of the latter, followed by mono-esterification with citronellol along with some protection-deprotection steps led to target molecule 2. The potential inhibitor 2 is supposed to be protonated at its most basic N atom by a carboxylic acid residue in the arabinosyl-transferase active site. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] pH-dependent translocation of ,-tocopherol transfer protein (,-TTP) between hepatic cytosol and late endosomesGENES TO CELLS, Issue 10 2003Masakuni Horiguchi Background:, ,-Tocopherol transfer protein (,-TTP), a member of the Sec14 protein family, plays an important role in transporting ,-tocopherol, a major lipid-soluble anti-oxidant, in the cytosolic compartment of hepatocytes and is known as a product of the causative gene for familial isolated vitamin E deficiency. It has been shown that the secretion of hepatocyte ,-tocopherol taken up with plasma lipoproteins is facilitated by ,-TTP. To explore the mechanism of ,-TTP mediated ,-tocopherol secretion, we investigated drugs which may affect this secretion. Results:, We found that, in a hepatocyte cell culture system, intracellular ,-tocopherol transport is impaired by chloroquine, an agent known for its function of elevating the pH in acidic compartments. Under chloroquine treatment, the diffuse cytosolic distribution of ,-TTP changes to a punctate pattern. Double-staining experiments with endocytosis markers revealed that ,-TTP accumulates transiently on the cytoplasmic surface of late endosomal membranes. This phenomenon is specific for hepatoma cell lines or primarily cultured hepatocytes. Other members of the Sec14 family, such as cellular retinaldehyde-binding protein (CRALBP) and supernatant protein factor (SPF), do not show this accumulation. Furthermore, we elucidate that the obligatory amino acid sequence for this function is located between amino acids 21 and 50, upstream of the N-terminal end of the lipid-binding domain. Conclusion:, We hypothesize that a liver-specific target molecule for ,-TTP exists on the late endosomal membrane surface. This transient binding may explain the mechanism of how ,-tocopherol is transferred from late endosomes to cytosolic ,-TTP. [source] Regulatory T cells and autoimmune diseaseIMMUNOLOGICAL REVIEWS, Issue 1 2005Silke Paust Summary:, Although T-cell clones bearing T-cell receptors with high affinity for self-peptide major histocompatibility complex (MHC) products are generally eliminated in the thymus (recessive tolerance), the peripheral T-cell repertoire remains strongly biased toward self-peptide MHC complexes and includes autoreactive T cells. A search for peripheral T cells that might exert dominant inhibitory effects on autoreactivity has implicated a subpopulation of CD4+CD25+ T cells called regulatory T cells (Tregs). Here, we discuss the role of cytokines and costimulatory molecules in the generation, maintenance, and function of Tregs. We also summarize evidence for the involvement of Tregs in controlling autoimmune diseases, including type 1 diabetes, experimental autoimmune encephalomyelitis, and inflammatory bowel disease. Last, we discuss our recent definition of the potential role of B7 expressed on activated T-effector cells as a target molecule for Treg-dependent suppression. These observations suggest that the engagement of B7 on effector T cells transmits an inhibitory signal that blocks or attenuates effector T-cell function. We restrict our comments to the suppression mediated by cells within the CD4 lineage; the impact of the cells within the CD8 lineage that may suppress via engagement of Qa-1 on effector T cells is not addressed in this review. [source] Expression and immunogenicity of NY-ESO-1 in hepatocellular carcinomaJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 8 2006Shinichiro Nakamura Abstract Background and Aim:, The present study was designed to investigate the expression of and humoral response against NY-ESO-1 in patients with hepatocellular carcinoma and to analyze the relationship between expression of NY-ESO-1 mRNA and clinicopathological features. Methods:, NY-ESO-1 mRNA and protein expression in surgically resected hepatocellular carcinoma specimens, adjacent non-cancerous liver and non-tumor bearing liver were examined by reverse transcription-polymerase chain reaction and immunohistochemical staining using a monoclonal antibody against NY-ESO-1 (ES121), respectively. The antibody response to NY-ESO-1 was examined by enzyme-linked immunosorbent assay using recombinant NY-ESO-1 protein. Results:,NY-ESO-1 mRNA was detected in 18 of 41 (43.9%) hepatocellular carcinomas. No NY-ESO-1 mRNA was expressed in 41 paired non-cancerous specimens and 18 specimens histologically diagnosed as liver cirrhosis or chronic hepatitis. Immunohistochemistry revealed heterogeneous expression of NY-ESO-1 protein in three of 18 NY-ESO-1 mRNA-positive hepatocellular carcinomas. None of 23 NY-ESO-1 mRNA-negative hepatocellular carcinomas expressed NY-ESO-1 protein. Antibody against NY-ESO-1 protein was detected in two of 92 patients with hepatocellular carcinoma. Both of these patients had tumors invading main branches of the portal vein. Conclusions:, The present study has demonstrated the expression of NY-ESO-1 mRNA in hepatocellular carcinoma and NY-ESO-1 antibody production in patients with advanced hepatocellular carcinoma. Although the enhancement of NY-ESO-1 protein expression and the activation of immune response of the patients with hepatocellular carcinoma are necessary, NY-ESO-1 has the potential to be a good target molecule for immunotherapy against advanced hepatocellular carcinoma. [source] Alkylation of azoles: Synthesis of new heterocyclic-based AT1 -non-peptide angiotensin (II) receptor antagonistsJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2007Amal Al-Azmi Several novel analogues of Losartan 2 were synthesized as potential non-peptide angiotensin (II) receptor antagonists. In these non-peptide analogues, the tetrazole and the substituted imidazole rings of Losartan 2 were replaced, respectively, by a carboxylic acid function or its methyl ester and substituted triazole, imidazole or benzimidazole moieties. The biphenyl bromide precursor 3 (BPE) used to introduce the linker between the acid/ester function and the heterocyclic moiety was synthesized using Suzuki biphenyl coupling and then incorporated into the target molecule by simple nucleophilic substitution. The fixed N-aryl isomeric forms of several azole and benzimidazole tautomers were successfully separated by HPLC using 50% aqueous acetonitrile as eluent. Intermediate reaction products and final target compounds were fully characterized spectroscopically. [source] Peptide vector for gene delivery with high affinity for phosphatidylserineJOURNAL OF PEPTIDE SCIENCE, Issue 10 2006Shinichi Kuriyama Abstract Since phosphatidylserine (PS) is known to translocate to the external face of the plasma membrane when the cell membrane becomes disordered, we decided to focus our attention on PS as a target molecule for gene delivery. In this paper, the novel peptide Td3701 was designed, synthesized, and characterized for its physico-chemico-biological properties. Td3701 simultaneously exhibited both characters as a DNA carrier and a sensor probe for active targeting, which seemed to be triggered by structural changes in the presence of PS. This is a very unique character among nonviral vectors, and it is believed that Td3701 could be used for selective gene delivery. Copyright © 2006 European Peptide Society and John Wiley & Sons, Ltd. [source] Principles of pharmacodynamics and their applications in veterinary pharmacologyJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2004P. LEES Pharmacodynamics (PDs) is the science of drug action on the body or on microorganisms and other parasites within or on the body. It may be studied at many organizational levels , sub-molecular, molecular, cellular, tissue/organ and whole body , using in vivo, ex vivo and in vitro methods and utilizing a wide range of techniques. A few drugs owe their PD properties to some physico-chemical property or action and, in such cases, detailed molecular drug structure plays little or no role in the response elicited. For the great majority of drugs, however, action on the body is crucially dependent on chemical structure, so that a very small change, e.g. substitution of a proton by a methyl group, can markedly alter the potency of the drug, even to the point of loss of activity. In the late 19th century and first half of the 20th century recognition of these facts by Langley, Ehrlich, Dale, Clarke and others provided the foundation for the receptor site hypothesis of drug action. According to these early ideas the drug, in order to elicit its effect, had to first combine with a specific ,target molecule' on either the cell surface or an intracellular organelle. It was soon realized that the ,right' chemical structure was required for drug,target site interaction (and the subsequent pharmacological response). In addition, from this requirement, for specificity of chemical structure requirement, developed not only the modern science of pharmacology but also that of toxicology. In relation to drug actions on microbes and parasites, for example, the early work of Ehrlich led to the introduction of molecules selectively toxic for them and relatively safe for the animal host. In the whole animal drugs may act on many target molecules in many tissues. These actions may lead to primary responses which, in turn, may induce secondary responses, that may either enhance or diminish the primary response. Therefore, it is common to investigate drug pharmacodynamics (PDs) in the first instance at molecular, cellular and tissue levels in vitro, so that the primary effects can be better understood without interference from the complexities involved in whole animal studies. When a drug, hormone or neurotransmitter combines with a target molecule, it is described as a ligand. Ligands are classified into two groups, agonists (which initiate a chain of reactions leading, usually via the release or formation of secondary messengers, to the response) and antagonists (which fail to initiate the transduction pathways but nevertheless compete with agonists for occupancy of receptor sites and thereby inhibit their actions). The parameters which characterize drug receptor interaction are affinity, efficacy, potency and sensitivity, each of which can be elucidated quantitatively for a particular drug acting on a particular receptor in a particular tissue. The most fundamental objective of PDs is to use the derived numerical values for these parameters to classify and sub-classify receptors and to compare and classify drugs on the basis of their affinity, efficacy, potency and sensitivity. This review introduces and summarizes the principles of PDs and illustrates them with examples drawn from both basic and veterinary pharmacology. Drugs acting on adrenoceptors and cardiovascular, non-steroidal anti-inflammatory and antimicrobial drugs are considered briefly to provide a foundation for subsequent reviews in this issue which deal with pharmacokinetic (PK),PD modelling and integration of these drug classes. Drug action on receptors has many features in common with enzyme kinetics and gas adsorption onto surfaces, as defined by Michaelis,Menten and Langmuir absorption equations, respectively. These and other derived equations are outlined in this review. There is, however, no single theory which adequately explains all aspects of drug,receptor interaction. The early ,occupation' and ,rate' theories each explain some, but not all, experimental observations. From these basic theories the operational model and the two-state theory have been developed. For a discussion of more advanced theories see Kenakin (1997). [source] Liquid chromatography with accurate mass measurement on a triple quadrupole mass spectrometer for the identification and quantification of N- lactoyl ethanolamine in wineMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 2 2010Bart Ruisch Abstract In this addendum to the original article [de Rijke, E., Ruisch, B.J., Bouter, N., König, T., Liquid chromatography with accurate mass measurement on a triple quadrupole mass-spectrometer for the identification and quantification of N- lactoyl ethanolamine in wine, Mol. Nutr. Food Res., 2006, 50, 351,355] a method is described to demonstrate that no potential cross-contamination from the reference target molecule had given rise to an incorrect positive identification of N- lactoyl ethanolamine in wine. [source] Derivatization for liquid chromatography/electrospray mass spectrometry: synthesis of tris(trimethoxyphenyl)phosphonium compounds and their derivatives of amine and carboxylic acidsRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2002William J Leavens A simple method for the derivatization of primary amines and carboxylic acids with tris(trimethoxyphenyl)phosphonium (TMPP) reagents to enhance their detection by electrospray mass spectrometry (ESI-MS) has been developed. The synthesis of novel TMPP reagents and their stable isotopically labelled analogues is described. Through the use of stable isotopically labelled TMPP ,tags', incorporation of a doublet (1:1, 1H/2H or 12C/13C) into the target molecule can be achieved, enabling the use of isotopic target analysis to detect compounds of unknown molecular weight but with a characteristic isotope pattern and accurate mass difference. Copyright © 2002 John Wiley & Sons, Ltd. [source] High mobility group box chromosomal protein 1: A novel proinflammatory mediator in synovitisARTHRITIS & RHEUMATISM, Issue 10 2002R. Kokkola Objective High mobility group box chromosomal protein 1 (HMGB-1) is a ubiquitous chromatin component expressed in nucleated mammalian cells. It has recently and unexpectedly been demonstrated that stimulated live mononuclear phagocytes secrete HMGB-1, which then acts as a potent factor that causes inflammation and protease activation. Macrophages play pivotal roles in the pathogenesis of arthritis. The aim of this study was to determine whether synovial macrophage expression of HMGB-1 is altered in human and experimental synovitis. Methods Intraarticular tissue specimens were obtained from healthy Lewis rats, Lewis rats with Mycobacterium tuberculosis,induced adjuvant arthritis, and from patients with rheumatoid arthritis (RA). Specimens were immunohistochemically stained for cellular HMGB-1. Extracellular HMGB-1 levels were assessed in synovial fluid samples from RA patients by Western blotting. Results Immunostaining of specimens from normal rats showed that HMGB-1 was primarily confined to the nucleus of synoviocytes and chondrocytes, with occasional cytoplasmic staining and no extracellular matrix deposition. In contrast, inflammatory synovial tissue from rats with experimental arthritis as well as from humans with RA showed a distinctly different HMGB-1 staining pattern. Nuclear HMGB-1 expression was accompanied by a cytoplasmic staining in many mononuclear cells, with a macrophage-like appearance and an extracellular matrix deposition. Analysis of synovial fluid samples from RA patients further confirmed the extracellular presence of HMGB-1; 14 of 15 samples had HMGB-1 concentrations of 1.8,10.4 ,g/ml. Conclusion The proinflammatory mediator HMGB-1 was abundantly expressed as a nuclear, cytoplasmic, and extracellular component in synovial tissues from RA patients and from rats with experimental arthritis. These findings suggest a pathogenetic role for HMGB-1 in synovitis and indicate a new potential therapeutic target molecule. [source] Osteopontin is a new target molecule for ovarian clear cell carcinoma therapyCANCER SCIENCE, Issue 8 2010Motoki Matsuura Recent studies have demonstrated overexpression of osteopontin (OPN) in ovarian clear cell carcinoma. Here, we revealed the role of OPN in invasiveness in ovarian clear cell carcinoma. We used immunofluorescence analysis to detect OPN in a total of 160 patient-derived specimens. Ovarian clear cell carcinoma cell lines, RMG-1 and TOV-21G, were used to monitor changes in OPN and integrin levels, and cell invasiveness following treatment with OPN, simvastatin, and transfection with siRNA. Immunofluorescence analysis revealed statistically significant differences among the histological groups, and ovarian clear cell carcinoma expressed a strong OPN signal. The OPN receptors, alpha v and 5, and beta 1 and 3 integrins, were increased after treatment with OPN. Invasion assays indicated that OPN enhanced in vitro extracellular matrix invasion dose-dependently in ovarian clear cell carcinoma. Simvastatin significantly reduced expression of OPN and the integrins, and decreased ECM invasion. RNA interference also suppressed ECM invasion. These results suggest that down- or up-regulation of OPN is involved in carcinoma cell invasion. We thus conclude that OPN regulation could have a crucial role in ovarian clear cell carcinoma therapy. (Cancer Sci 2010) [source] Simaomicin ,, a polycyclic xanthone, induces G1 arrest with suppression of retinoblastoma protein phosphorylationCANCER SCIENCE, Issue 2 2009Yukio Koizumi Recent progress in cancer biology research has shown that abnormal proliferation in tumor cells can be attributed to aberrations in cell cycle regulation, especially in G1 phase. During the course of searching for microbial metabolites that affect cell cycle distribution, we have found that simaomicin ,, a polycyclic xanthone antibiotic, arrests the cell cycle at G1 phase. Treatment of T-cell leukemia Jurkat cells with 3 nM simaomicin , induced an increase in the number of cells in G1 and a decrease in those in G2,M phase. Cell cycle aberrations induced by simaomicin , were also detected in colon adenocarcinoma HCT15 cells. Simaomicin , had antiproliferative activities in various tumor cell lines with 50% inhibitory concentration values in the range of 0.3,19 nM. Furthermore, simaomicin , induced an increase in cellular caspase-3 activity and DNA fragmentation, indicating that simaomicin , promotes apoptosis. The retinoblastoma protein phosphorylation status of simaomicin ,-treated cell lysate was lower than that of control cells, suggesting that the target molecule of simaomicin , is in a pathway upstream of retinoblastoma protein phosphorylation. In the course of evaluating polycyclic xanthone antibiotics structurally related to simaomicin ,, we also found that cervinomycin A1 stimulated accumulation of treated cells in G1 phase. These results indicate that the polycyclic xanthones, including simaomicin , and cervinomycin A1, may be candidate cancer chemotherapeutic agents. (Cancer Sci 2009; 100: 322,326) [source] Daintain/AIF-1 promotes breast cancer proliferation via activation of the NF-,B/cyclin D1 pathway and facilitates tumor growthCANCER SCIENCE, Issue 5 2008Shou Liu Recent research indicates that inflammatory factors play important roles in the initiation and progression of cancers, including breast cancer. Daintain/allograft inflammatory factor-1 (AIF-1) is a crucial mediator in the inflammatory response, but it has not yet been reported whether daintain/AIF-1 is involved in the development of breast cancers. In this study, immunohistochemical analysis found strong positive expression of daintain/AIF-1 in breast ductal tumor epithelia, but only weakly positive or negative expression in the adjacent histologically normal ductal epithelia. Then, the effect of daintian/AIF-1 on the proliferation of the breast cancer cell line MDA-MB-231 was explored via transduction of the daintian/AIF-1 gene into the cells, and via inhibition of the expression of daintain/AIF-1 through short interference RNA. The results demonstrated that up-regulation and down-regulation of daintain/AIF-1 expressions promoted and inhibited the proliferation of MDA-MB-231, respectively. More interestingly, daintain/AIF-1 overexpression facilitated tumor growth in female nude mice. Furthermore, we found that daintain/AIF-1 overexpression up-regulated the expression of cyclin D1 and enhanced the transcriptional activity of nuclear factor-kappa B (NF-,B), a regulator of cyclin D1 expression. In contrast, the down-regulation of daintain/AIF-1 expression decreased cyclin D1 expression and inhibited the transcriptional activity of NF-,B. These results strongly suggest that daintain/AIF-1 can promote the growth of breast tumors via activating NF-,B signaling, which consequently up-regulates the expression of cyclin D1, implying that daintain/AIF-1 may be a novel target molecule for the prognosis and therapy of breast cancer. (Cancer Sci 2008; 99: 952,957) [source] Synthetic small interfering RNA targeting heat shock protein 105 induces apoptosis of various cancer cells both in vitro and in vivoCANCER SCIENCE, Issue 7 2006Seiji Hosaka We previously reported that heat shock protein 105 (HSP105), identified by serological analysis of a recombinant cDNA expression library (SEREX) using serum from a pancreatic cancer patient, was overexpressed in various human tumors and in the testis of adult men by immunohistochemical analysis. In the present study, to elucidate the biological function of the HSP105 protein in cancer cells, we first established NIH3T3 cells overexpressing murine HSP105 (NIH3T3-HSP105). The NIH3T3-HSP105 cells acquired resistance to apoptosis induced by heat shock or doxorubicin. The small interfering RNA (siRNA)-mediated suppression of HSP105 protein expression induced apoptosis in human cancer cells but not in fibroblasts. By a combination of siRNA introduction and doxorubicin or heat shock treatment, apoptosis was induced synergistically in a human colon cancer cell line, HCT116. In vivo, siRNA inoculation into the human gastric cancer cell line KATO-3 established in the flank of an NOD SCID mouse suppressed the tumor growth. This siRNA-induced apoptosis was mediated through caspases, but not the p53 tumor suppressor protein, even though the HSP105 protein was bound to wild-type p53 protein in HCT116 cells. These findings suggest that the constitutive overexpression of HSP105 in cancer cells is involved in malignant transformation by protecting tumor cells from apoptosis. HSP105 may thus be a novel target molecule for cancer therapy and a treatment regimen using synthetic siRNA to suppress the expression of HSP105 protein may provide a new strategy for cancer therapy. (Cancer Sci 2006; 97: 623,632) [source] Stereocontrolled Synthesis of the C21,C38 Fragment of the Unnatural Enantiomer of the Antibiotic Nystatin A1CHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2004Thilo Berkenbusch Dr. Abstract The C21,C38 fragment all- trans - 41 of the unnatural enantiomer 1 of nystatin A1 was prepared starting from the N -propionyl oxazolidinone 9. Aldol adduct ent - 8 (ee > 96,%) derived in two steps was hydroborated with (thexyl)BH2. Oxidative work-up and treatment with acid furnished ,-lactone 4. It contains the complete stereotetrade of the target molecule. The ,,,-unsaturated ester 28 was reached after another four steps. It should be a precursor for the polyene moieties of a variety of polyol,polyene macrolides. Illustrating that, the ,,,-unsaturated aldehyde 29 obtained from 28 and DIBAL was extended by 10 C atoms in four steps yielding the C21,C38 segment 41. The latter set of transformations included the regio- and stereoselective Claisen rearrangement 32,35. [source] Hybridization-Sensitive On,Off DNA Probe: Application of the Exciton Coupling Effect to Effective Fluorescence QuenchingCHEMISTRY - AN ASIAN JOURNAL, Issue 6 2008Shuji Ikeda Dr. Abstract The design of dyes that emit fluorescence only when they recognize the target molecule, that is, chemistry for the effective quenching of free dyes, must play a significant role in the development of the next generation of functional fluorescent dyes. On the basis of this concept, we designed a doubly fluorescence-labeled nucleoside. Two thiazole orange dyes were covalently linked to a single nucleotide in a DNA probe. An absorption band at approximately 480,nm appeared strongly when the probe was in a single-stranded state, whereas an absorption band at approximately 510,nm became predominant when the probe was hybridized with the complementary strand. The shift in the absorption bands shows the existence of an excitonic interaction caused by the formation of an H aggregate between dyes, and as a result, emission from the probe before hybridization was suppressed. Dissociation of aggregates by hybridization with the complementary strand resulted in the disruption of the excitonic interaction and strong emission from the hybrid. This clear change in fluorescence intensity that is dependent on hybridization is useful for visible gene analysis. [source] Principles of pharmacodynamics and their applications in veterinary pharmacologyJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2004P. LEES Pharmacodynamics (PDs) is the science of drug action on the body or on microorganisms and other parasites within or on the body. It may be studied at many organizational levels , sub-molecular, molecular, cellular, tissue/organ and whole body , using in vivo, ex vivo and in vitro methods and utilizing a wide range of techniques. A few drugs owe their PD properties to some physico-chemical property or action and, in such cases, detailed molecular drug structure plays little or no role in the response elicited. For the great majority of drugs, however, action on the body is crucially dependent on chemical structure, so that a very small change, e.g. substitution of a proton by a methyl group, can markedly alter the potency of the drug, even to the point of loss of activity. In the late 19th century and first half of the 20th century recognition of these facts by Langley, Ehrlich, Dale, Clarke and others provided the foundation for the receptor site hypothesis of drug action. According to these early ideas the drug, in order to elicit its effect, had to first combine with a specific ,target molecule' on either the cell surface or an intracellular organelle. It was soon realized that the ,right' chemical structure was required for drug,target site interaction (and the subsequent pharmacological response). In addition, from this requirement, for specificity of chemical structure requirement, developed not only the modern science of pharmacology but also that of toxicology. In relation to drug actions on microbes and parasites, for example, the early work of Ehrlich led to the introduction of molecules selectively toxic for them and relatively safe for the animal host. In the whole animal drugs may act on many target molecules in many tissues. These actions may lead to primary responses which, in turn, may induce secondary responses, that may either enhance or diminish the primary response. Therefore, it is common to investigate drug pharmacodynamics (PDs) in the first instance at molecular, cellular and tissue levels in vitro, so that the primary effects can be better understood without interference from the complexities involved in whole animal studies. When a drug, hormone or neurotransmitter combines with a target molecule, it is described as a ligand. Ligands are classified into two groups, agonists (which initiate a chain of reactions leading, usually via the release or formation of secondary messengers, to the response) and antagonists (which fail to initiate the transduction pathways but nevertheless compete with agonists for occupancy of receptor sites and thereby inhibit their actions). The parameters which characterize drug receptor interaction are affinity, efficacy, potency and sensitivity, each of which can be elucidated quantitatively for a particular drug acting on a particular receptor in a particular tissue. The most fundamental objective of PDs is to use the derived numerical values for these parameters to classify and sub-classify receptors and to compare and classify drugs on the basis of their affinity, efficacy, potency and sensitivity. This review introduces and summarizes the principles of PDs and illustrates them with examples drawn from both basic and veterinary pharmacology. Drugs acting on adrenoceptors and cardiovascular, non-steroidal anti-inflammatory and antimicrobial drugs are considered briefly to provide a foundation for subsequent reviews in this issue which deal with pharmacokinetic (PK),PD modelling and integration of these drug classes. Drug action on receptors has many features in common with enzyme kinetics and gas adsorption onto surfaces, as defined by Michaelis,Menten and Langmuir absorption equations, respectively. These and other derived equations are outlined in this review. There is, however, no single theory which adequately explains all aspects of drug,receptor interaction. The early ,occupation' and ,rate' theories each explain some, but not all, experimental observations. From these basic theories the operational model and the two-state theory have been developed. For a discussion of more advanced theories see Kenakin (1997). [source] Recombinant EDA or Sonic Hedgehog rescue the branching defect in Ectodysplasin A pathway mutant salivary glands in vitroDEVELOPMENTAL DYNAMICS, Issue 10 2010K.L. Wells Abstract Hypohidrotic ectodermal dysplasia (HED) is characterized by defective ectodermal organ development. This includes the salivary glands (SGs), which have an important role in lubricating the oral cavity. In humans and mice, HED is caused by mutations in Ectodysplasin A (Eda) pathway genes. Various phenotypes of the mutant mouse EdaTa/Ta, which lacks the ligand Eda, can be rescued by maternal injection or in vitro culture supplementation with recombinant EDA. However, the response of the SGs to this treatment has not been investigated. Here, we show that the submandibular glands (SMGs) of EdaTa/Ta mice exhibit impaired branching morphogenesis, and that supplementation of EdaTa/Ta SMG explants with recombinant EDA rescues the defect. Supplementation of EdardlJ/dlJ SMGs with recombinant Sonic hedgehog (Shh) also rescues the defect, whereas treatment with recombinant Fgf8 does not. This work is the first to test the ability of putative Eda target molecules to rescue Eda pathway mutant SMGs. Developmental Dynamics 239:2674,2684, 2010. © 2010 Wiley-Liss, Inc. [source] Fabrication, Characterization, and Application of ,Sandwich-Type' Electrode Based on Single-Walled Carbon Nanotubes and Room Temperature Ionic LiquidELECTROANALYSIS, Issue 17 2008Xuzhi Zhang Abstract The much-enhanced electrochemical responses of potassium ferricyanide and methylene blue (MB) were firstly explored at the glassy carbon electrode modified with single-walled carbon nanotubes (SWNT/GCE), indicating the distinct electrochemical activity of SWNTs towards electroactive molecules. A hydrophobic room temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), was used as electrode modification material, which presented wide electrochemical windows, proton permeation and selective extraction ability. In consideration with the advantages of SWNTs and RTIL in detecting target molecules (TMs), a novel strategy of ,sandwich,type' electrode was established with TMs confined by RTIL between the SWNT/GCE and the RTIL membrane. The strategy was used for electrochemical detection of ascorbic acid (AA) and dopamine (DA), and detection limits of 400 and 80 fmol could be obtained, respectively. The selective detection of DA in the presence of high amount of AA could also be realized. This protocol presented many attractive advantages towards voltammetric detection of TMs, such as low sample demand, low cost, high sensitivity, and good stability. [source] Development of microreactor array chip-based measurement system for massively parallel analysis of enzymatic activityELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 4 2009Yosuke Hosoi Abstract Microarray chip technology such as DNA chips, peptide chips, and protein chips is one of the promising approaches for achieving high-throughput screening (HTS) of biomolecule function since it has great advantages in feasibility of automated information processing due to one-to-one indexing between array position and molecular function as well as massively parallel sample analysis as a benefit of downsizing and large-scale integration. Mostly, however, the function that can be evaluated by such microarray chips is limited to affinity of target molecules. In this paper, we propose a new HTS system and enzymatic activity based on microreactor array chip technology. A prototype of the automated and massively parallel measurement system for fluorometric assay of enzymatic reactions was developed by the combination of microreactor array chips and a highly sensitive fluorescence microscope. Design strategy of microreactor array chips and an optical measurement platform for the high-throughput enzyme assay are discussed. © 2009 Wiley Periodicals, Inc. Electron Comm Jpn, 92(4): 35,41, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10056 [source] Dynamics of marine bacterial and phytoplankton populations using multiplex liquid bead array technologyENVIRONMENTAL MICROBIOLOGY, Issue 4 2010Xavier Mayali Summary Heterotrophic bacteria and phytoplankton dominate the biomass and play major roles in the biogeochemical cycles of the surface ocean. Here, we designed and tested a fast, high-throughput and multiplexed hybridization-based assay to detect populations of marine heterotrophic bacteria and phytoplankton based on their small subunit ribosomal DNA sequences. The assay is based on established liquid bead array technology, an approach that is gaining acceptance in biomedical research but remains underutilized in ecology. End-labelled PCR products are hybridized to taxon-specific oligonucleotide probes attached to fluorescently coded beads followed by flow cytometric detection. We used ribosomal DNA environmental clone libraries (a total of 450 clones) and cultured isolates to design and test 26 bacterial and 10 eukaryotic probes specific to various ribotypes and genera of heterotrophic bacteria and eukaryotic phytoplankton. Pure environmental clones or cultures were used as controls and demonstrated specificity of the probes to their target taxa. The quantitative nature of the assay was demonstrated by a significant relationship between the number of target molecules and fluorescence signal. Clone library sequencing and bead array fluorescence from the same sample provided consistent results. We then applied the assay to a 37-day time series of coastal surface seawater samples from the Southern California Bight to examine the temporal dynamics of microbial communities on the scale of days to weeks. As expected, several bacterial phylotypes were positively correlated with total bacterial abundances and chlorophyll a concentrations, but others were negatively correlated. Bacterial taxa belonging to the same broad taxonomic groups did not necessarily correlate with one another, confirming recent results suggesting that inferring ecological role from broad taxonomic identity may not always be accurate. [source] The active methanotrophic community in hydromorphic soils changes in response to changing methane concentrationENVIRONMENTAL MICROBIOLOGY, Issue 2 2006Claudia Knief Summary Methanotrophic communities were studied in several periodically water-saturated gleyic soils. When sampled, each soil had an oxic upper layer and consumed methane from the atmosphere (at 1.75 ppmv). In most gleyic soils the Km(app) values for methane were between 70 and 800 ppmv. These are higher than most values observed in dry upland soils, but lower than those measured in wetlands. Based on cultivation-independent retrieval of the pmoA -gene and quantification of partial pmoA gene sequences, type II (Alphaproteobacteria) methanotrophs of the genus Methylocystis spp. were abundant (> 107pmoA target molecules per gram of dry soil). Type I (Gammaproteobacteria) methanotrophs related to the genera Methylobacter and Methylocaldum/Methylococcus were detected in some soils. Six pmoA sequence types not closely related to sequences from cultivated methanotrophs were detected as well, indicating that diverse uncultivated methanotrophs were present. Three Gleysols were incubated under different mixing ratios of 13C-labelled methane to examine 13C incorporation into phospholipid fatty acids (PLFAs). Phospholipid fatty acids typical of type II methanotrophs, 16:0 and 18:1,7c, were labelled with 13C in all soils after incubation under an atmosphere containing 30 ppmv of methane. Incubation under 500 ppmv of methane resulted in labelling of additional PLFAs besides 16:0 and 18:1,7c, suggesting that the composition of the active methanotrophic community changed in response to increased methane supply. In two soils, 16:1 PLFAs typical of type I methanotrophs were strongly labelled after incubation under the high methane mixing ratio only. Type II methanotrophs are most likely responsible for atmospheric methane uptake in these soils, while type I methanotrophs become active when methane is produced in the soil. [source] Carbohydrate-Based VEGF InhibitorsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 36 2007Tobias Haag Abstract Cyclic peptide,carbohydrates (compounds 1a,c, 2, 33, 34) were designed and synthesized to act as mimetics of loop 2 of the proangiogenic molecule vascular endothelial growth factor D (VEGF-D). The mimetics were designed to inhibit dimerization of the receptors (VEGFR-2 and VEGFR-3) by VEGF-D, and thus have the potential to inhibit angiogenesis. To this end, in the previously described cyclic octapeptide CNEESLIC and the cyclic nonapeptide CGNEESLIC inhibitors derived from VEGF-D loop 2, the NEES tetrapeptide residue was replaced by a carbohydrate scaffold having the amino acid side chain mimics in positions proposed by modeling studies. Attachment of the additional amino acids using the Fmoc technology, then formation of the cyclic disulfides, and finally total deprotection afforded the target molecules of which 2 and 34 showed an ability to inhibit the biological activity of VEGF-D through VEGFR-2 in cell-based assays, albeit at high mimetic concentration.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Multifunctional Au-Coated TiO2 Nanotube Arrays as Recyclable SERS Substrates for Multifold Organic Pollutants DetectionADVANCED FUNCTIONAL MATERIALS, Issue 17 2010Xuanhua Li Abstract A multifunctional Au-coated TiO2 nanotube array is made via synthesis of a TiO2 nanotube array through a ZnO template, followed by deposition of Au particles onto the TiO2 surface using photocatalytic deposition and a hydrothermal method, respectively. Such arrays exhibit superior detection sensitivity with high reproducibility and stability. In addition, due to possessing stable catalytic properties, the arrays can clean themselves by photocatalytic degradation of target molecules adsorbed to the substrate under irradiation with UV light into inorganic small molecules using surface-enhanced Raman spectroscopy (SERS) detection, so that recycling can be achieved. Finally, by detection of Rhodamine 6G (R6G) dye, herbicide 4-chlorophenol (4-CP), persistent organic pollutant (POP) dichlorophenoxyacetic acid (2,4-D), and organophosphate pesticide methyl-parathion (MP), the unique recyclable properties indicate a new route in eliminating the single-use problem of traditional SERS substrates and show promising applications for detecting other organic pollutants. [source] Waveguide Sensors: Use of Reversal Nanoimprinting of Nanoparticles to Prepare Flexible Waveguide Sensors Exhibiting Enhanced Scattering of the Surface Plasmon Resonance (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 11 2010Mater. The image displays a flexible surface plasmon resonance (SPR)-based waveguide sensor prepared by directly imprinting metal nanoparticles onto flexible plates, as presented by H.-L. Chen et al. on page 1742. The metal nanoparticles could scatter the evanescent wave and the guiding mode waves from the SPR-based waveguide simultaneously. The scattering signal underwent a distinguishable red-shift when the target molecules bound to the particles. [source] Multiple roles of PPAR, in brown adipose tissue under constitutive and cold conditionsGENES TO CELLS, Issue 2 2010Makiko Komatsu Peroxisome proliferator-activated receptor , (PPAR,) is a member of the nuclear receptor family, regulating fatty acid degradation in many organs. Two-dimensional SDS-PAGE of brown adipose tissue (BAT) from PPAR,-null mice produced a higher-density spot. Proteomic analysis indicated that the protein was pyruvate dehydrogenase , (PDH,). To observe PDH, regulation in BAT, the organ was stimulated by long-term cold exposure, and the activities of associated enzymes were investigated. Histological and biochemical analyses of BAT showed a significant decrease in the triglyceride content in wild-type mice and some degree of decrease in PPAR,-null mice on cold exposure. Analyses of molecules related to glucose metabolism showed that the expression of PDH, is under PPAR,-specific regulation, and that glucose degradation ability may decrease on cold exposure. In contrast, analyses of molecules related to fatty acid metabolism showed that numerous PPAR,/, target molecules are induced on cold exposure, and that fatty acid degradation ability in wild-type mice is markedly enhanced and also increases to same degree in PPAR,-null mice on cold exposure. Thus, this study proposes novel and multiple roles of PPAR, in BAT. [source] Recurrent copy number gain of transcription factor SOX2 and corresponding high protein expression in oral squamous cell carcinomaGENES, CHROMOSOMES AND CANCER, Issue 1 2010Kolja Freier Gene copy number aberrations are involved in oral squamous cell carcinoma (OSCC) development. To delineate candidate genes inside critical chromosomal regions, array-CGH was applied to 40 OSCC specimens using a microarray covering the whole human genome with an average resolution of 1 Mb. Gene copy number gains were predominantly found at 1q23 (9 cases), 3q26 (11), 5p15 (13), 7p11 (7), 8q24 (17), 11q13 (15), 14q32 (8), 19p13 (8), 19q12 (7), 19q13 (8), and 20q13 (9), whereas gene copy number losses were detected at 3p21-3p12 (15), 8p32 (11), 10p12 (8), and 18q21-q23 (10). Subsequent mRNA expression analyses by quantitative real time polymerase chain reaction found high mRNA expression of candidate genes SOX2 in 3q26.33, FSLT3 in 19p13.3, and CCNE1 in 19q12. Tissue microarray (TMA) analyses in a representative OSCC collection found gene copy number gain for SOX2 in 52% (115/223) and for CCNE1 in 31% (72/233) of the tumors. Immunohistochemical analyses on TMA sections of the corresponding proteins detected high expression of SOX2 in 18.1% (49/271) and of CyclinE1 in 23.3% (64/275) of tumors analyzed. These findings indicate that SOX2 and CCNE1 might be activated via gene copy number gain and participate in oral carcinogenesis. The combination of array-CGH with TMA analyses allows rapid pinpointing of novel promising candidate genes, which might be used as therapeutic stratification markers or target molecules for therapeutic interference. © 2009 Wiley-Liss, Inc. [source] Comparative gene expression profiling of olfactory ensheathing glia and Schwann cells indicates distinct tissue repair characteristics of olfactory ensheathing gliaGLIA, Issue 12 2008Elske H.P. Franssen Abstract Olfactory ensheathing glia (OEG) are a specialized type of glia that support the growth of primary olfactory axons from the neuroepithelium in the nasal cavity to the brain. Transplantation of OEG in the injured spinal cord promotes sprouting of injured axons and results in reduced cavity formation, enhanced axonal and tissue sparing, remyelination, and angiogenesis. Gene expression analysis may help to identify the molecular mechanisms underlying the ability of OEG to recreate an environment that supports regeneration in the central nervous system. Here, we compared the transcriptome of cultured OEG (cOEG) with the transcriptomes of cultured Schwann cells (cSCs) and of OEG directly obtained from their natural environment (nOEG), the olfactory nerve layer of adult rats. Functional data mining by Gene Ontology (GO)-analysis revealed a number of overrepresented GO-classes associated with tissue repair. These classes include "response to wounding," "blood vessel development," "cell adhesion," and GO-classes related to the extracellular matrix and were overrepresented in the set of differentially expressed genes between both comparisons. The current screening approach combined with GO-analysis has identified distinct molecular properties of OEG that may underlie their efficacy and interaction with host tissue after implantation in the injured spinal cord. These observations can form the basis for studies on the function of novel target molecules for therapeutic intervention after neurotrauma. © 2008 Wiley-Liss, Inc. [source] Combination of thalidomide and cisplatin in an head and neck squamous cell carcinomas model results in an enhanced antiangiogenic activity in vitro and in vivoINTERNATIONAL JOURNAL OF CANCER, Issue 8 2007Gergely P. Vasvari Abstract Thalidomide is an immunomodulatory, antiangiogenic drug. Although there is evidence that it might be more effective in combination with chemotherapy the exact mechanism of action is unclear. Therefore, we investigated its effect in combination with metronomically applied cisplatin in a xenotransplant mouse model characteristic for advanced head and neck squamous cell carcinomas, its possible synergistic action in vitro, and which tumor-derived factors might be targeted by thalidomide. Although thalidomide alone was ineffective, a combined treatment with low-dose cisplatin inhibited significant tumor growth, proliferation and angiogenesis in vivo as well as migration and tube formation of endothelial cells in vitro. Noteworthy, the latter effect was enhanced after coapplication of cisplatin in nontoxic doses. An inhibitory effect on tumor cell migration was also observed suggesting a direct antitumor effect. Although thalidomide alone did not influence cell proliferation, it augmented antiproliferative response after cisplatin application emphasizing the idea of a potentiated effect when both drugs are combined. Furthermore, we could show that antiangiogenic effects of thalidomide are related to tumor-cell derived factors including vascular endothelial growth factor, basic fibroblast growth factor, hepatocyte growth factor and Il-8 some known and with, granulocyte colony stimulating growth factor and granulocyte macrophage colony stimulating growth factor, some new target molecules of thalidomide. Altogether, our findings reveal new insights into thalidomide-mediated antitumor and antiangiogenic effects and its interaction with cytostatic drugs. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||