Synthesis of enantiomerically pure 1-O-phosphocholine-2-O-acyl-octadecane and 1-O-phosphocholine-2-N-acyl-octadecane

This is the first report on the chemical synthesis of enantiomerically pure R- or S-1-O-phosphocholine-2-O-acyl-octadecanes and R- or S-1-O-phosphocholine-2-N-acyl-octadecanes. From a structural point of view these phospholipids are intermediates between phosphatidylcholine and sphingomyelin. The synthesis of these model compounds is based on R- or S-1.2-O-isopropylidene-glyceraldeyde for chain elongation in a Wittig reaction with pentadecane-triphenylphosphine bromide. The resulting 1.2-O-isopropylidene-octadec-3-en is converted to R- or S-1.2-octadecanediol by catalytic hydrogenation of the double bond and by acidic removal of the isopropylidene protecting group. Tritylation of R- or S-1.2-octadecanediol results in the general intermediates R- or S-1-O-trityl-2-hydroxy-octadecane. These are the key intermediates for the synthesis of the phosphatidylcholine- or sphingomyelin-like end products. R- or S-1-O-phosphocholine-2-O-acyl-octadecane is obtained from the tritylated intermediates via benzylation in position 2, acidic detritylation and conversion of the R- or S-1-hydroxy-2-benzyl-octadecanes to the respective phosphocholines via the phosphoethanolamines. Catalytic hydrogenolysis of the benzyl group results in R- or S-1-O-phosphocholine-2-hydroxy-octadecane, which is converted to the phosphatidylcholine-like end products by acylation. R- or S-1-O-phosphocholine-2-N-acyl-octadecane is obtained from the tritylated intermediate by conversion of the R- or S-2-hydroxy group into the N-phthalimido group, which is achieved by inversion of the configuration using the Mitsunobu reaction with phthalimid. After acidic detritylation, the product is converted to the respective S- or R-1-O-phosphocholine derivative in a similar sequence of reactions. The phthalimido group is converted to the 2-amino group, and acylation results in the sphingomyelin-like end products.     

Synthesis of 1-hydroxy and 1-acyloxypyrrolidin-2-ones

A series of 1-hydroxypyrrolidin-2-ones (v) has been prepared by reduction of gamma-nitrocarboxylic acid esters with Zn dust in the presence of ammonium chloride. Acylation of compounds (v) gave the corresponding 1-acyloxypyrrolidin-2-ones (VI). None of the synthesized compounds showed any significant antiflammatory activity.     

LFA-1 interaction with ICAM-1 and ICAM-2 regulates Th2 cytokine production

The role of CD28/B7 and LFA-1/ICAM costimulation in proliferation and Th1/Th2 differentiation of naive CD4+ T cells was addressed using T cells from DO11.10 TCR transgenic mice stimulated by dendritic cells. The blockade of either CD28/B7 or LFA-1/ICAM interactions partially inhibited T cell proliferation. By comparison, blocking CD28/B7 costimulation inhibited IL-4 and IL-5 (Th2 cytokine) production, whereas blocking LFA-1/ICAM-1 or LFA-1/ICAM-2 led to a significant increase (15- to 40-fold) of Th2 cytokines. The combination of anti-ICAM-1 and anti-ICAM-2 mAbs had a synergistic effect with a 100- to 1000-fold increase of Th2 cytokine production. Thus, these two costimulatory pathways have opposing roles in the regulation of Th2 development.     

BAG-1 and Bcl-2 in IL-2 signaling

Some cytokines can prolong cell survival in hematolymphoid cells and thus may be crucial for regulation of hematolymphoid cell numbers. It has been shown that mitogenic cytokines can induce not only cellular proliferation but also cellular survival by inhibiting apoptosis in hematolymphoid cells. The signals transduced by these cytokines eventually go to the nucleus and induce expression of their specific target genes. In this context, the induction of anti-apoptotic molecules such as Bcl-2 oncoprotein and BAG-1 protein seems to be a key event for the anti-apoptotic function of cytokines. In T lymphocytes, the interaction of interleukin-2 (IL-2) with its receptor (IL-2R) induces both cellular proliferation and cellular survival. The IL-2R consists of three subunits, i.e., IL-2Ralpha, IL-2R(beta)c, and IL-2R(gamma)c chains. Structure-function analysis of the IL-2R(beta)c chain has revealed that there are at least two functional domains within the subunit. The serine-rich (S) region but not the acidic (A) region within the (beta)c chain is responsible for the mitogenic signaling of IL-2R. The S region is also crucial for the cellular survival signaling, which include the induction of anti-apoptotic gene expressions bcl-2 and bag-l. However, the cellular survival signaling is segregated from the mitogenic signaling in independence from the Jak-family protein kinase activation and rapamycin sensitivity. Segregation of the two signaling pathways of a cytokine receptor has also been shown in receptors of the other mitogenic cytokines. Current topics regarding signal transductions of cytokine receptors responsible for the suppression of apoptosis are discussed in this review.     

Stereoselective conjugation of prostaglandin A2 and prostaglandin J2 with glutathione, catalyzed by the human glutathione S-transferases A1-1, A2-2, M1a-1a, and P1-1

Prostaglandins containing an alpha,beta-unsaturated keto group, such as prostaglandin A2 (PGA2) and prostaglandin J2 (PGJ2), inhibit cell proliferation. These cyclopentenone prostaglandins may be conjugated with GSH chemically or enzymatically via glutathione S-transferases, and this has been suggested to result in inhibition of the antiproliferative mode of action. In the present study, the role of the major human GSTs in the conjugation of PGA2 and PGJ2 with GSH was investigated with purified enzymes, i.e., the Alpha-class enzymes GST A1-1 and GST A2-2, the Mu-class enzyme GST M1a-1a, and the Pi-class enzyme GST P1-1. The GSH conjugates were separated from the parent compound by HPLC and identified by fast atom bombardment mass spectrometry and 1H-NMR. Two GSH conjugates were found for both PGA2 and PGJ2, the R- and S-GSH conjugates of both prostaglandins. Incubation experiments with PGA2 and PGJ2 (70-600 microM) clearly showed the role of individual GSTs in the conjugation of PGA2 and PGJ2. Compared to the chemical reaction, enzyme activities towards PGA2 were up to 5.4 times as high (GSTA1-1) at the lowest concentration (70 microM), while at the highest concentration (600 microM) enzyme activities were up to 3.0 times as high (GST P1-1). For PGJ2, enzyme activities were up to 4.3 (GSTM1a-1a, 70 microM) and up to 3.1 (GSTM1a-1a, 600 microM) times as high. As expected, similar amounts of the R- and S-conjugates of both prostaglandins were found in the chemical reaction. Striking stereoselectivities in conjugating activities were observed for GST A1-1 and GST P1-1. GST A1-1 favors the formation of the R-GSH conjugates of both prostaglandins. GST P1-1 showed a clear selectivity with regard to the formation of the S-GSH conjugate of PGA2. However, this selectivity was not found for the formation of the S-GSH conjugate of PGJ2. GSTM1a-1a showed no stereoselectivity with regard to the GSH conjugation of both PGA2 and PGJ2. GSTA2-2 only showed some minor formation of the R-GSH conjugate of PGJ2. The possible implications of the observed stereoselectivity on the effects of PGA2 and PGJ2 are discussed.     

Synthesis and biological investigations of 1-(tetrahydropyran-2'-yl)- and 1-(tetrahydrofuran-2'-yl)benzimidazoles and 1/2-(tetrahydropyran-2'-yl)- and 1/2-(tetrahydrofuran-2'-yl)benzotriazoles

Sets of benzimidazole and benzotriazole derivatives bearing on position 1 or 2 a tetrahydrofuranyl or tetrahydropyranyl moieties were prepared through the addition of the suitable benzazoles on 2,3-dihydrofuran and 3,4-dihydro-2H-pyran. The reactions were carried on either without solvent or in carbon tetrachloride solution. In the last case some peculiar chlorinated side products were isolated and characterized. Twenty compounds were screened for in vitro antitumoral and anti-HIV-1 activities and found poorly active or completely inactive. On the other hand several compounds exhibited good tracheal relaxant activity in vitro; compound 8, 11, 16, 24 and 26 resulted more active than theophylline in this test, while compound 11 was comparable to amrinone till the concentration of 3 micrograms/ml. Finally, compound 5 resulted endowed with a strong diuretic and saluretic activity at the dose of 3 mg/Kg, thus representing a new lead for discovering new diuretic agents.     

Cytotoxic and anticancer activities of some 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides

A series of 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides demonstrated marked cytotoxicity towards approximately 55 human tumour cell lines from different neoplastic diseases. In general they were more potent than melphalan and displayed selective toxicity towards human leukemic cells. A representative compound, 1-phenyl-2-dimethyl-aminomethyl-2-propen-1-one hydrochloride (2a), had similar cytotoxicity as melphalan towards murine P388 and L1210 leukemic cells. In addition, 2a reduced the sizes of a number of human tumour xenografts including colon, prostatic and melanotic cancers passaged in athymic mice. Compound 2a showed excellent activity towards Ehrlich ascites carcinoma and B16F1 melanoma in mice which was enhanced using niosomes. One may conclude from the data generated that 1-aryl-2-dimethylaminomethyl-2-propen-1-one hydrochlorides are a novel series of cytotoxic and anticancer agents.     

Effect of cigarette smoke on CYP1A1, CYP1A2 and CYP2B1/2 of nasal mucosae in F344 rats

BACKGROUND: Dobutamine stress echocardiography (DSE) is sensitive and specific in detecting myocardial ischemia of male patients. However, there have been few reports about the use of DSE for the detection of coronary artery disease (CAD) in women. METHODS: DSE was evaluated in 51 consecutive women who underwent concomitant quantitative coronary angiography. Forty-four of the 51 patients received stress thallium-201 single-photon emission computed tomography (SPECT), and 30 of the 51 patients had interpretable results (exercise level > or = 85% of age-predicted maximal heart rate) of treadmill exercise. Twenty-nine patients had angiographically documented CAD defined as > or = 50% diameter stenosis. RESULTS: The overall sensitivity of DSE and stress 201Tl SPECT in detecting CAD was 93% and 79% (p = nonsignificant), and the specificity was 82% and 75% (p = nonsignificant), respectively. A combination of both tests increased the sensitivity (96%) at the expense of some decrease in specificity (60%). The agreement of DSE and 201Tl SPECT was 68% (30 of 44; kappa statistic = 0.35; p < 0.0001). The overall sensitivity, specificity, and accuracy in detecting CAD by treadmill exercise test and DSE were 71% vs 93% (p = nonsignificant), 44% vs 82% (p = 0.036), and 57% vs 88% (p = 0.003). In patients with abnormal results of treadmill exercise testing, the false-positive rate in detecting CAD was 2 (18%) of 11 in patients with abnormal results of DSE and 7 (88%) of 8 in those with normal results of DSE (p = 0.005). In patients with normal results of treadmill exercise testing, the false-negative rate in detecting CAD was 4 (100%) of 4 in patients with abnormal results of DSE and 0 (0%) of 7 in those with normal results of DSE (p = 0.003). CONCLUSION: The diagnostic accuracy of DSE was similar to that of stress 201Tl SPECT in women. DSE was able to stratify female patients with either abnormal or normal results of treadmill exercise testing and to avoid unnecessary cardiac catheterization.     

Protection against acetaminophen toxicity in CYP1A2 and CYP2E1 double-null mice

PURPOSE: To determine the diagnostic accuracy of computed tomography (CT) for pneumonia in patients with adult respiratory distress syndrome (ARDS). MATERIALS AND METHODS: CT scans were obtained within 1 week of bronchoscopic sampling in 31 patients receiving mechanical ventilation for ARDS for more than 48 hours. Of 11 patients with pneumonia, five developed symptoms less than 11 days after the onset of ARDS (early ARDS). CT scans were rated for pneumonia independently by four radiologists who were unaware of the clinical diagnosis. Diagnostic accuracy was defined by means of the area under the receiver operating characteristic curve, or A2. RESULTS: Diagnostic accuracy for pneumonia was fair (A2 = 0.69 +/- 0.04 [standard error]) owing to 70% true-negative ratings (vs 59% true-positive ratings). The generalizability coefficient was good (0.79). No single CT finding was significantly different for the presence of pneumonia. Nondependent opacities predominated in 10 (91%) of 11 patients with pneumonia and 12 (60%) of 20 without pneumonia. Nondependent opacities predominated in nine (56%) of 16 patients with early ARDS and 13 (87%) of 15 with late ARDS. CONCLUSION: CT has fair diagnostic accuracy for ventilator-associated pneumonia in patients with ARDS owing primarily to identification of patients without pneumonia. No single CT sign was significantly different for pneumonia, but dependent atelectasis was more common in patients with early ARDS without pneumonia.     

Synthesis and antimyoctic properties of 1-(2-alkyl-2-phenylethyl)-1H-imidazoles

The synthesis of 1-(2-alkyl-2-phenylethyl)-1H-imidazoles was accomplished starting from the corresponding phenylacetonitriles. Via alkylation, esterification, and sodium borohydride reduction-in the presence of lithium iodide-beta-phenylalconols were obtained. Mesylation of these alcohols and refluxing with imidazole in dimethylformamide furnished title compounds, which were active in vitro against dermatophytes, yeasts, other fungi, and gram-positive bacteria and in vivo as well as in vitro against Candida albicans.     

Cases 1, 2, and 3

A quantitative analysis of amino acids in microsamples of dried blood spots by chemical ionization mass spectrometry has been developed. Isotope ratio determination was used as the quantitating technique via multiple labelled internal standards. This procedure yields excellent precision and accuracy as demonstrated by the analysis of known amino acid mixtures and of phenylalanine in the blood from newborns.