Biphenyl-derivatives of 2-amino-7-phosphono-heptanoic acid, a novel class of potent competitive N-methyl-D-aspartate receptor antagonists--II. Pharmacological characterization in vivo.

A selection of biphenyl-analogues of 2-amino-7-phosphonoheptanoic acid (AP7), N-methyl-D-aspartate (NMDA) receptor antagonists with high affinity in vivo efficacy. The lead compound SDZ EAB 515 was found to inhibit L-phenylalanine uptake by the large neutral amino acid carrier in vitro and in vivo; active transport may thus confer a good bioavailability to this class of compounds. CNS effects were demonstrated by significant changes in 2-deoxyglucose-uptake in various brain regions at doses from 1 to 10 mg/kg i.

Biphenyl-derivatives of 2-amino-7-phosphonoheptanoic acid, a novel class of potent competitive N-methyl-D-aspartate receptor antagonist--I. Pharmacological characterization in vitro.

Omega-Phosphono-substituted alpha-amino acids have long been known to be antagonists at the N-methyl-D-aspartate (NMDA) receptor. D-2-Amino-5-phosphonopentanoic (D-AP5) and D-2-amino-7-phosphonoheptanoic (D-AP7) acids are the "prototype" compounds of this kind. Insertion of a biphenyl-moiety in the middle of the AP7 chain results in increased affinity and reverses the enantioselectivity from a D- to an L-form preference (Müller et al.

Function and regulation of Fc epsilon RI expression on monocytes from non-atopic donors.

Background: The high affinity receptor for IgE (Fc epsilon RI) has recently been identified on antigen presenting cells, i.e. Langerhans cells and monocytes from atopic donors and it was hypothesized that Fc epsilon RI expression levels correlated with allergy.

Inhibitors of human immunodeficiency virus type 1 protease containing 2-aminobenzyl-substituted 4-amino-3-hydroxy-5-phenylpentanoic acid: synthesis, activity, and oral bioavailability.

Systematic modifications of HIV protease inhibitor (2R,3S,4S)-4-[[(benzyloxycarbonyl)-L-valyl]-amino]-3-hydroxy-2-[(4- methoxybenzyl)amino]-5-phenylpentanoyl)-L-valine 2-(aminomethyl)- benzimidazole amide led to a novel series of inhibitors with shortened, modified carboxy terminus. Their synthesis, in vitro enzyme inhibitory data, and antiviral activities are reported. Of particular interest are derivatives featuring the (1S,2R)-1-amino-2-hydroxyindan moiety at the P2'-position since some of them exhibit substantial oral bioavailability in mice.

Inhibition of protein prenylation down-regulates signalling by inflammatory mediators in human keratinocytes.

Several inflammatory mediators have been shown to activate phospholipase C in human keratinocytes via GTP-binding protein-coupled receptors. Since GTP-binding proteins are prenylated proteins, we have examined the role of prenylation in signal transduction in HaCaT keratinocytes. Indirect inhibition of prenylation with the HMG CoA reductase inhibitors fluvastatin or compactin decreased bradykinin-stimulated inositol 1,4,5-triphosphate generation.

Pharmacokinetics and pharmacodynamics of multiple-dose terbinafine.

Data from clinical trials of terbinafine for the treatment of onychomycosis were analyzed with the following two objectives: 1) to identify demographic predictors of the duration and extent of systemic drug exposure; and 2) to explore whether increased systemic exposure or demographic predictors of increased exposure were associated with altered safety or efficacy. Demographic predictors of exposure were identified by a model-free, nonparametric approach applied to the sparse pharmacokinetic data from the onychomycosis studies. Those covariates were then incorporated into a multicompartmental nonlinear mixed effects model.

Pharmacokinetics of abecarnil in patients with renal insufficiency.

Objective: To characterize the pharmacokinetics of a single 5 mg oral dose of abecarnil in subjects with varying degrees of renal impairment.

Methods: Twenty-six subjects were enrolled in this open-label parallel-group study. Ten subjects had normal renal function (NRF; creatinine clearance [CLCR] > or = 85 ml/min/1.

Effect of alkalizing agents on the processing of the beta-amyloid precursor protein.

We investigated the processing pathway of the amyloid precursor protein (APP) to the secretion of beta A4 under the treatment of ammonium chloride (NH4Cl), bafilomycin A1 (bafA1), or chloroquine, all three agents thought to raise the pH in acidic compartments. HEK-293 cells expressing wild-type APP (APPwt) and APP carrying the Swedish double mutation (APPswe) were affected in a different manner: while cells expressing APPswe decreased the secretion of beta A4 after treatment with bafA1 and NH4Cl, cells expressing APPwt compensated the drug-induced decrease in beta A4 by an increased generation of alternative beta A4-related peptides. Within cells APP accumulated, while the formation of a C-terminal fragment of APP generated by beta-secretase was completely inhibited.

Study of coumarin metabolism by Chinese hamster lung fibroblasts expressing a human cytochrome P450 using H-nmr.

1. Human cytochrome P450 2A6 is expressed in Chinese hamster lung fibroblasts. The isozyme hydroxylates coumarin at the 7-position.

Antigen presentation in allergic sensitization.

IgE antibodies, when cross-linked by allergen on the surface of effector cells such as mast cells and basophils, are known to be directly responsible for immediate type hypersensitivity reactions. In addition, IgE may be involved in other, indirect, mechanisms, fundamental to the pathogenesis of allergic diseases, such as enhancement of the antigen capturing capacity of antigen presenting cells. IgE mediated antigen presentation could lead to a continuous activation of the immune system by very low concentrations of allergen.

IL-4-dependent proliferation of BA/F3 cells expressing a growth-negative mutant of the human IL-4 receptor is restored by enforced expression of Bcl-2.

We have studied the regulation of growth and apoptosis in murine BA/F3 cells stably expressing cytoplasmic deletion mutants of the human interleukin-4 receptor (hIL-4R). Previously, we showed that BA/F3 cell transfectants expressing a cytoplasmic deletion mutant of the hIL-4R that lacks the region between Thr(462) and Ala(580), referred to as delta R3, fails to proliferate in the presence of hIL-4. Here we report that supertransfection of delta R3-expressing cells with a constitutively active murine bcl-2 gene results in prolonged survival of the delta R3/bel-2 double transfectants in the absence of cytokines.

Inhibition of HIV-1 replication in lymphocytes by mutants of the Rev cofactor eIF-5A.

Eukaryotic initiation factor 5A(eIF-5A) is a cellular cofactor require d for the function of the human immunodeficiency virus type-1 (HIV-1) Rev trans-activator protein. The majority of a set of eIF-5A mutants did not support growth of yeast cells having an inactivated genomic copy of eIF-5A, indicating that the introduced mutation eliminated eIF-5A activity. Two nonfunctional mutants, eIF-5AM13 and eIF-5AM14, retained their binding capacity for the HIV-1 Rev response element:Rev complex.

The murine homolog of TB2/DP1, a gene of the familial adenomatous polyposis (FAP) locus.

The cDNA of the murine counterpart of the human TB2/DP1 (deleted in polyposis) gene, one of the six genes deleted in severe cases of familial adenomatous polyposis (FAP) disease, was isolated and analyzed. The murine transcript is 734-bp long and thereby considerably shorter than the 3100-bp human counterpart. This is due to a completely different 3' untranslated region in mouse which starts immediately after the translational stop codon, thereby deleting a RFLP (restriction-fragment length polymorphism) marker for this disease.

Antiviral efficacy in vivo of the anti-human immunodeficiency virus bicyclam SDZ SID 791 (JM 3100), an inhibitor of infectious cell entry.

SID 791, a bicyclam inhibiting human immunodeficiency virus (HIV) replication in vitro by blocking virus entry into cells, is an effective inhibitor of virus production and of depletion of human CD4+ T cells in HIV type 1-infected SCID-hu Thy/Liv mice. Steady levels of 100 ng of SID 791 or higher per ml in plasma resulted in statistically significant inhibition of p24 antigen formation. Daily injections of SID 791 caused a dose-dependent decrease in viremia, and this inhibition could be potentiated by coadministration of zidovudine or didanose.

The simultaneous estimation of the influx and efflux blood-brain barrier permeabilities of gabapentin using a microdialysis-pharmacokinetic approach.

Purpose: To determine the apparent bidirectional permeabilities of gabapentin (GBP) across the blood-brain barrier (BBB) using a novel microdialysis-pharmacokinetic approach.

Methods: Rats were administered intravenous infusions of [14C]GBP to achieve clinically relevant steady-state plasma concentrations. Microdialysis was used to monitor GBP concentration in brain extracellular fluid (ECF) in conscious animals.

Evaluation of the metal ion requirement of the human deoxyhypusine hydroxylase from HeLa cells using a novel enzyme assay.

Hypusine synthesis in the eukaryotic initiation factor 5A is a unique two-step posttranslational modification. After deoxyhypusine is generated by the deoxyhypusine synthase, the deoxyhypusine hydroxylase (EC 1.14.

Characterization of prenyl protein transferase enzymes in a human keratinocyte cell line.

Prenylation is a post-translational modification of proteins that involves the attachment of an isoprenoid group derived from mevalonic acid, either 15-carbon farnesyl or 20-carbon geranylgeranyl, to a specific carboxy-terminal domain of acceptor proteins. Three prenyl transferase enzymes have been identified so far. In this paper we report the presence of two prenyl transferases in the HaCaT human keratinocyte cell line.

Characterization of squalene epoxidase activity from the dermatophyte Trichophyton rubrum and its inhibition by terbinafine and other antimycotic agents.

Squalene epoxidase (SE) is the primary target of the allylamine antimycotic agents terbinafine and naftifine and also of the thiocarbamates. Although all of these drugs are employed primarily in dermatological therapy, SE from dermatophyte fungi has not been previously investigated. We report here the biochemical characterization of SE activity from Trichophyton rubrum and the effects of terbinafine and other inhibitors.

Oral administration of muramyl dipeptide into mice modulates cell proliferation, immunoglobulin synthesis and cytokine mRNA levels in gut associated lymphoid tissues.

Muramyl peptides (MDPs) are synthetic immunostimulants capable of potentiating a multitude of immune functions following parenteral administration into a host. The parent molecule MDP was also found to exert certain activities when applied via the oral route. Thus, we have studied the effect of oral treatment of mice with MDP on the lymphoproliferative responses, immunoglobulin secretion and cytokine induction in gut-associated lymphoid tissues (GALT) employing lymphocyte transformation test, ELISA and RT-PCR, respectively.

Antitumor activity of the R- and S-enantiomers of RS-2-[[hydroxy[[2-[ (octadecyloxy)methyl]tetrahydrofuran-2-yl]methoxy]-phosphinyl]oxy]-N, N,N,-trimethylethylaminium hydroxide inner salt.

The R- and S-enantiomers of 2-[[hydroxyl[[2-[(octadecyloxy) methyl]tetrahydrofuran-2-yl]methoxy]-phosphinyl]oxy]-N,N,N,- trimethylethylaminium hydroxide salt (SRI 62-834) have been evaluated in several assays to determine potential antitumor activity. The S-enantiomer showed slightly greater cytotoxic activity than the R- or RS-forms against several murine tumor cell lines. In the mouse Meth A fibrosarcoma model, the S-enantiomer was ca.

Conformations of synthetic beta peptides in solid state and in aqueous solution: relation to toxicity in PC12 cells.

The secondary structures of peptides beta 25-35 (the active toxic fragment) and beta 35-25 (reverse sequence and non-toxic fragment), as well as of the amidated beta (25-35)-NH2 peptide were investigated in aqueous solution and in the solid state by means of Fourier-transformed infrared spectroscopy and circular dichroism spectroscopy. The conformations of the beta 25-35 and beta 35-25 in solid state were identical and contained mostly beta-sheet structures. In solid state the amidated beta (25-35)-NH2 peptide also contained mostly beta-sheet structures.

Molecular characterization of a cDNA encoding functional human deoxyhypusine synthase and chromosomal mapping of the corresponding gene locus.

Deoxyhypusine synthase is essentially required for the post-translational formation of hypusine, a modification of a specific lysine residue in eukaryotic initiation factor 5A, which appears to be pivotal for cell proliferation. From a human peripheral blood mononuclear cells cDNA library we isolated two independent sequences encoding biologically active deoxyhypusine synthase. DNA sequence analysis revealed a 369 amino acid protein with a molecular mass of 41.

Inflammatory and Physiological Roles of Chemokines.

Chemokines, members of the family of chemotactic peptides, have a well documented function in different inflammatory diseases where they induce leukocyte emigration into lesions. Several recent observations indicate that, in addition to pathological states, chemokines are also produced and secreted under physiological conditions by various exocrine glands in amounts sufficient for their full biological effect. The glands involved in chemokine production and secretion include eccrine sweat glands, lactating mammary glands, lacrimal and salivary glands.

The 'monocytic' cell line I937 displays typical B cell characteristics.

The monocytic cell line I937 was derived from U937 by sorting for cells with high expression of MHC class II molecules. Further analysis of these class II molecules revealed the presence of the HLA-DR3 subtype suggesting that the cell line was a potential candidate for testing antigen presentation to T cells restricted by HLA-DR3. We found that the T cell clones CFTS4:2.

Bradykinin upregulates immediate-early gene mRNA in human keratinocytes.

We investigated the effect of bradykinin on the expression of the proto-oncogenes c-fos, c-jun and c-myc and on cell proliferation in the human keratinocyte cell line, HaCaT. Analysis of mRNAs was done by Northern blotting with single-stranded DNA hybridization probes. Bradykinin caused a rapid and transient accumulation in c-fos and c-jun mRNAs.