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Biomedical subjects

Stevan W Djuric

Publications and source records attributed to Stevan W Djuric.

18 recordsLinked to original sources

Discovery of 2-[4-{{2-(2S,5R)-2-cyano-5-ethynyl-1-pyrrolidinyl]-2-oxoethyl]amino]- 4-methyl-1-piperidinyl]-4-pyridinecarboxylic acid (ABT-279): a very potent, selective, effective, and well-tolerated inhibitor of dipeptidyl peptidase-IV, useful for the treatment of diabetes.

Dipeptidyl peptidase-IV (DPP-IV) inhibitors are poised to be the next major drug class for the treatment of type 2 diabetes. Structure-activity studies of substitutions at the C5 position of the 2-cyanopyrrolidide warhead led to the discovery of potent inhibitors of DPP-IV that lack activity against DPP8 and DPP9. Further modification led to an extremely potent (Ki(DPP)(-)(IV) = 1.0 nM) and selective (Ki(DPP8) > 30 microM; Ki(DPP9) > 30 microM) clinical candidate, ABT-279, that is orally available, efficacious, and remarkably safe in preclinical safety studies.

Adenosine Deaminase↗

1,4-Dihydroindeno[1,2-c]pyrazoles as novel multitargeted receptor tyrosine kinase inhibitors.

A series of 1,4-dihydroindeno[1,2-c]pyrazoles with a 3-thiophene substituent carrying a urea-type side chain were identified as potent multitargeted (VEGFR and PDGFR families) receptor tyrosine kinase inhibitors. A KDR homology model suggested that the urea moiety is able to interact with a recognition motif in the hydrophobic specificity pocket of the enzyme.

Amino Acid Motifs↗

Rapamycin analogs with reduced systemic exposure.

The synthesis and biological activities of rapamycin (I) analogs modified at the C-40 position are reported. Emphasis placed on compounds that potentially have an improved safety profile on account of their shorter in vivo half-life when compared with rapamycin.

Animals↗

Rapid and efficient synthesis of 1,2,4-oxadiazoles utilizing polymer-supported reagents under microwave heating.

1,2,4-Oxadiazoles can be rapidly and efficiently synthesized from a variety of readily available carboxylic acids and amidoximes using either method A or method B. The use of commercially available polymer-supported reagents combined with microwave heating resulted in high yields and purities of the product 1,2,4-oxadiazoles in an expeditious manner. [structure: see text]

Carboxylic Acids↗

Synthesis of diazepinones via intramolecular transamidation.

[structure: see text] The synthesis of a collection of bicyclic fused azepinones via an intramolecular beta-lactam ring-opening strategy is reported. Depending on the chirality of the various inputs, complete stereocontrol of product formation is achieved.

Journal Article↗

Preliminary in vivo pharmacokinetic and pharmacodynamic evaluation of a novel calcineurin-independent inhibitor of NFAT.

A-285222 (A-285) is a bis-trifluoromethyl-pyrazole (BTP), a novel class of immunosuppressive agents that inhibit NFAT activity in vitro in human and non-human primate cells through a calcineurin-independent mechanism. In this preliminary study, we treated cynomolgus monkeys with different doses of A-285 for several days. Blood was collected from all animals at different times during the study. From these samples, plasma concentrations of A-285 were measured by liquid chromatography/mass spectrometry (LC/MS), and intracellular T-cell production of the cytokines IL-2, IFN-gamma, and TNF-alpha was quantified by flow cytometry using a mitogen-stimulated whole blood assay. Marked inhibition of cytokine production occurred after administration of the first dose of A-285, and this effect was comparable to that of cyclosporine. While neurological toxic side effects were seen when the plasma concentration of A-285 exceeded 4 microg/ml, at lower plasma levels the drug was well tolerated over 2 weeks and its pharmacodynamic effects were sustained throughout this time.

Administration, Oral↗

Cloning and characterization of the glucagon receptor from cynomologous monkey.

The glucagon receptor was cloned from cynolomologous monkey. A frame-shift mutation at the 3' end of the monkey transcript results in a C-terminal extension of 14 amino acids. This extension is not observed in either the human or rodent glucagon receptors. Monkey glucagon receptor was expressed in CHO cells, either with (mkGCGR) or without (mkGCGRDelta14) the 14-amino acid C-terminal extension to approximate the human receptor. Both forms of the monkey receptor bound glucagon with similar affinity and showed glucagon-stimulated cAMP production, however the full-length form of the monkey receptor (mkGCGR) was less sensitive to glucagon in its ability to stimulate cAMP than the shortened form (mkGCGRDelta14). PCR of genomic DNA from baboon and rhesus monkeys suggests that they express a form of the receptor similar to that of cynomologous monkey, while in chimpanzee, the receptor is similar to the human form.

Animals↗

Pyrrolidine and piperidine analogues of SC-57461A as potent, orally active inhibitors of leukotriene A(4) hydrolase.

The synthesis and biological evaluation of a series of functionalized pyrrolidine- and piperidine-containing analogues of our lead LTA(4) hydrolase inhibitor, SC-57461A, is described. A number of compounds showed excellent potency in our in vitro screens and several demonstrated good oral activity in a mouse ex vivo assay. These efforts led to the identification of SC-56938 (14) as a potent, orally active inhibitor of LTA(4) hydrolase.

Administration, Oral↗

TH1 and TH2 cytokine inhibition by 3,5-bis(trifluoromethyl)pyrazoles, a novel class of immunomodulators.

In order to discover novel immunomodulators for application in treating autoimmune diseases, a stable Jurkat transfectant was constructed in which luciferase reporter gene is driven by a full-length IL-2 promotor. A chemical library was screened to identify compounds that inhibited luciferase expression in Jurkat transfectants stimulated with PMA and ionomycin. A class of compounds (bis-trifluoromethyl pyrazole, BTPs) was identified from this screen. BTPs were shown to inhibit anti-CD3 and anti-CD28 antibody-induced IL-2 secretion, mixed lymphocyte reaction, and Con A-induced T cell proliferation in normal human peripheral blood T cells. In addition, mRNA levels of IL-4, IL-5, IL-9, IL-10, IL-13, IL-15, and IFN-gamma were markedly inhibited by BTPs in peripheral blood mononuclear cells stimulated by Con A as determined by multi-probe RNA protection assay. Furthermore, IL-2, IL-4, IL-5, and IFN-gamma secretion by Hut 78 cells or CD3(+) T cells stimulated with PMA plus ionomycin or anti-CD3 antibody plus PMA were inhibited in a concentration-dependent manner by BTPs. Therefore, BTPs inhibit a wide spectrum of cytokine production including TH1 and TH2 type cytokines. Taken together, these compounds may be useful for treating autoimmune diseases and organ transplant rejection.

Adjuvants, Immunologic↗

Glucagon receptor antagonists for the treatment of type II diabetes: current prospects.

As the incidence of Type II diabetes (T2DM) will increase to 200 million cases worldwide by 2010, the search for new, effective agentsfor its treatment has been pushed into overdrive. According to Unger's bihormonal hypothesis, elevated levels of circulating glucagon in T2DM patients results in increased rates of hepatic glucose synthesis and glycogen metabolism, translating to excessive plasma glucose levels. In this context, considerable efforts have been made to identify glucagon antagonists for the treatment of T2DM. This review reflects research in this area from 1999 to 2002.

Amino Acid Sequence↗

T cell activation induces a noncoding RNA transcript sensitive to inhibition by immunosuppressant drugs and encoded by the proto-oncogene, BIC.

In a search for novel early T cell activation transcripts, we identified expressed sequence tags (ESTs) more abundantly expressed in normal human CD4(+) T lymphocytes fully activated by a 5 h exposure to CD3 plus CD28 mAbs, compared to the same cells stimulated with either CD3 mAb or CD28 mAb alone. An EST was identified that hybridized with a 1.7 kb transcript expressed in activated T cells but was undetectable by Northern blot analysis in resting T cells or other normal tissues. The T cell transcript was maximally induced within 6 h and remained elevated for at least 47 h. Induction of the transcript was blocked by cyclosporin A, FK506, and dexamethasone but not by rapamycin. The transcript was polyadenylated but lacked an open reading. A BLAST search of the NCBI database revealed that the transcript shared identity with the recently reported human BIC proto-oncogene that encodes a noncoding mRNA (W. Tam, Gene 274 (2001) 157). Our data demonstrate that transcriptional activation of the BIC proto-oncogene is an early and sustained T cell activation event and suggest an important role for noncoding mRNA in T cell function.

Antibodies, Monoclonal↗