Synthesis and biological evaluation of L- and D-configuration 1,3-dioxolane 5-azacytosine and 6-azathymine nucleosides

Novel L- and D-configuration dioxolane 5-azacytosine and 6-azathymine nucleosides have been synthesized and evaluated for biological activity. (-)-(2S,4S)-1-[2-(Hydroxymethyl)-1,3-dioxolan-4-yl]-5-azacytosine (6) showed significant activity against HBV, whereas the D-configuration analogue (14) has been found to exhibit potent anti-HIV activity.

Manganese administration induces the increased production of dopamine sulfate and depletion of dopamine in Sprague-Dawley rats

Sprague-Dawley rats were used as an experimental model for investigating the effects of manganese poisoning on the serum levels of unsulfated and sulfated forms of dopamine and its biosynthetic precursors, L-Dopa and L-p-tyrosine. Groups of rats were treated daily with Mn(2+) (20 mg or 40 mg; in the form of MnSO(4)) or Na(+) (20 mg; in the form of Na(2)SO(4)). High performance liquid chromatography (HPLC) analysis of the serum samples taken after a 50-day experimental period revealed that the serum level of dopamine sulfate increased by more than 10 times compared with untreated control rats or rats treated with sodium sulfate. In contrast, there was a dramatic decrease (by as much as 4.8 times) in the serum level of unsulfated dopamine in manganese-treated rats. The serum levels of L-Dopa sulfate and L-p-tyrosine sulfate were also markedly elevated, although not as much as those of dopamine sulfate. Meanwhile, the serum levels of unsulfated L-Dopa and L-p-tyrosine showed no dramatic changes. Atomic absorption spectrophotometric analysis revealed in general an accumulation of manganese in the four organ samples taken from manganese-treated rats. Compared with liver, heart, and kidney, the highest degree of manganese accumulation in manganese-treated rats appeared to be in brain. These results together suggested a role for manganese in stimulating the dopamine-sulfating sulfotransferases in brain, thereby leading to the depletion of dopamine in vivo.

Retinoic acid-mediated G1 arrest is associated with induction of p27(Kip1) and inhibition of cyclin-dependent kinase 3 in human lung squamous carcinoma CH27 cells

Retinoids are promising agents for the prevention and treatment of several human malignancies including lung cancer. In this study, the effect of retinoic acid (RA) on cell growth and the mechanism of growth modulation were examined in human lung squamous carcinoma CH27 cells. Here we report that RA mediated the dose- and time-dependent growth arrest in G1 phase, accompanied by the up-regulation of p27(Kip1) and the down-regulation of the cyclin-dependent kinase 3 (Cdk3) and p21(CIP1/Waf1) proteins. Furthermore, RA-induced growth arrest of CH27 cells was also associated with increased retinoic acid receptor beta (RARbeta) and reduced c-Myc expression. However, RA had no effect on the levels of cyclins A, D1, D3, E, or H, or on Cdk2, Cdk4, Cdk5, CDk6, Cdk7, p16(Ink4A), p15(Ink4B), p53, or pRb proteins in CH27 cells. Evaluation of the kinase activity of cyclin-Cdk complexes showed that RA increases p27(Kip1) expression in CH27 cells leading to markedly reduced cyclin A/Cdk2 kinase activity and slightly reduced cyclin E/Cdk2 kinase activity, with no effect on cyclin D/Cdk4 and cyclin D/Cdk6 activities. Moreover, coincident with the decrease in kinase activity was a drastic increase in cyclin A-bound p27(Kip1). These results suggest that increases in the levels of p27(Kip1) and its binding to cyclin A, as well as reduction of Cdk3 protein expression, are strong candidates for the cell cycle regulator that prevents the entry into the S phase in RA-treated CH27 cells, with prolongation of G1 phase and inhibition of DNA synthesis.

Effect of recombinant human platelet-activating factor-acetylhydrolase on allergen-induced asthmatic responses

Platelet-activating factor (PAF) is a potent lipid mediator associated with key features of asthma such as airway constriction, eosinophil infiltration, edema, and mucus accumulation. Regulation of PAF occurs primarily through degradation to biologically inactive lyso-PAF by cellular and secreted PAF-acetylhydrolase (PAF-AH). We evaluated the effect of human recombinant PAF-AH (rPAF-AH) on the dual phase asthmatic response in atopic subjects with mild asthma. Effects on induced sputum cell counts and differentials, eosinophilic cationic protein (ECP), and tryptase were evaluated. Enrolled subjects demonstrated a positive skin test and a dual asthmatic response to allergen inhalation challenge. Fourteen subjects received rPAF-AH (1 mg/kg) or placebo intravenously in a randomized, double blind, placebo-controlled, two-period crossover study. Treatment with rPAF-AH did not significantly reduce either the early- or late-asthmatic response. Sputum eosinophil cell counts were not affected by treatment, but there was a trend toward a reduction in sputum neutrophils. No significant change in sputum ECP and tryptase was observed between rPAF-AH and placebo. Thus, at the dose studied, the unique anti-PAF agent rPAF-AH demonstrated no significant effect on the allergen-induced dual-phase asthmatic response.

Mutational analysis of the substrate binding/catalytic domains of human M form and P form phenol sulfotransferases

Human monoamine (M) form and simple phenol (P) form phenol sulfotransferases (PSTs) are greater than 93% identical in their primary sequences and yet display distinct substrate specificities and other enzymatic properties. Through the generation and characterization of a series of chimeric PSTs, we have previously demonstrated two highly variable regions within their sequences to be responsible for determining their substrate phenotypes (Sakakibara, Y., Takami, Y., Nakayama, T., Suiko, M., and Liu, M.-C. (1998) J. Biol. Chem. 273, 6242-6247). By employing the site-directed mutagenesis technique, the present study aims to identify and quantitatively evaluate the specific amino acid residues critical to the substrate binding and catalysis in these two enzymes. Twelve mutated M-PSTs and seven mutated P-PSTs were generated, expressed, and purified. Enzymatic characterization showed that, of the twelve mutated M-PSTs, mutations at residues Asp-86, Glu-89, and Glu-146 resulted in a dramatic decrease in V(max)/K(m) with dopamine as substrate, being greater than 450 times for the D86A/E89I/E146A mutated M-PST. With p-nitrophenol as substrate, the V(max)/K(m) determined for the D86A/E89I/E146A-mutated M-PST increased more than 25 times and approached that determined for the wild-type P-PST. These results indicated that the concerted action of the three mutated residues (D86A, E89I, and E146A) is sufficient for the conversion of the substrate phenotype of M-PST to that of P-PST. Among the mutated P-PSTs, the I89E- and A146E-mutated P-PSTs displayed considerable deviations in V(max)/K(m) with dopamine or p-nitrophenol as substrate. No corresponding changes, however, were detected with the opposite compound as substrate. These results indicated that, in contrast to M-PST, mutations at Ala-86, Ile-89, and Ala-146 to the corresponding residues in M-PST are not sufficient for rendering the change of P-PST substrate phenotype to that of M-PST. For both M-PSTs and P-PSTs, mutations at Lys-48 or His-108 led to the loss of sulfotransferase activities, indicating their importance in the catalytic mechanism.

Blood glutathione decreases in chronic diseases

Previously a high blood glutathione level was correlated with long life span in the mouse and rat and in healthy elderly human beings. This raised the question of whether low glutathione levels occur in unhealthy subjects. To this end, 74 consecutive patients newly admitted to the hospital, with ages ranging from 21 to 89 years and diagnosed with chronic diseases, were studied along with 32 healthy control subjects. Blood samples were analyzed for reduced (GSH) and oxidized (GSSG) glutathione with a high-performance liquid chromatography-dual electrochemical method. The data were integrated with the clinical diagnoses and statistically analyzed. Marked total glutathione decreases from the control levels occurred in over 36% of the patients with chronic diseases including cancer and genitourinary, gastrointestinal, cardiovascular, and musculoskeletal diseases (P < .001). The deficit was due to low GSH concentrations and not to GSSG, which was the same as that in the control subjects. The conclusion is that a decrease in GSH is a risk factor for chronic diseases that may be used to monitor the severity and progress of the diseases. Future work is necessary to elucidate the mechanism of action.

Blood glutathione and cysteine changes in cardiovascular disease

The need to investigate aminothiols such as glutathione (GSH), cysteine (Cys), and homocysteine (Hcy) in blood is stimulated by the current interest in hyperhomocysteinemia as a risk factor for atherosclerosis. Our current goal was to determine whether various cardiovascular (CV) diseases altered levels of GSH and Cys in blood and the relationships between these two thiols. Blood samples from 96 patients with atherosclerosis and other CV diseases were analyzed and compared with those from 33 control subjects. In CV patients, GSH levels were normal, but free plasma Cys was significantly higher (P < .0001). In patients with atherosclerosis, bound plasma Cys was 21% higher than that in control subjects (P < .0001), and in patients with other CV diseases it was 14% higher (P = .023). Also, in patients with CV diseases, correlations of free GSH with free Cys (P < .007) and total GSH and Cys with age (P < .04) differed from that in control subjects. There were no differences related to functional disability or duration of disease. A key finding was that these abnormal levels of plasma Cys occurred in both atherosclerotic and non-atherosclerotic CV diseases. These results indicate that high levels of oxidized and bound Cys in CV patients create an oxidative environment that may increase susceptibility to vascular damage.

Adjuvant sequential chemotherapy with doxorubicin plus cyclophosphamide, methotrexate, and fluorouracil (ACMF) with concurrent radiotherapy in resectable advanced breast cancer

Doxorubicin (Adriamycin) is an anthracycline effective in breast cancer. Despite a worldwide acceptance of Adriamycin in the adjuvant chemotherapy to maximize the survival benefit in the higher risk patients with breast cancer with promising results, oncologists in general do not favorably consider anthracyclines in the adjuvant treatment setting because of concern about the acute and chronic drug-related toxicity. For high-risk patients with breast cancer with more than three positive axillary lymph nodes, this series adopted a modified sequential regimen of ACMF first with Adriamycin (A) as a single agent in 3-weekly administration for three courses, and then a combination of cyclophosphamide, methotrexate, fluorouracil (CMF) every 3 to 4 weeks for six courses given in an outpatient setting concurrent with radiation therapy as an adjuvant treatment. A total of 56 patients underwent modified radical mastectomy and 3 others breast conservation surgery for their invasive breast cancer. Forty-seven (84%) patients completed the intended adjuvant treatment and 1 patient died of infection from treatment-related neutropenia. As a whole, the 3-year overall survival and disease-free survival rates of 56 patients analyzed were 82.3% and 64.4%, respectively. In this high-risk group, patients with four to nine positive nodes showed a slightly better trend of survival than those with 10 or more positive nodes without reaching statistically significant difference (36-month overall survival: 90.9% vs. 72.5%, p = 0.06; disease-free survival: 78.7% vs. 47.8%, p = 0.38). In this entire group of patients, locoregional recurrence was absent. A total of 55 episodes of grade III and IV hematologic toxicity were observed, with only one death from neutropenic sepsis. This modified ACMF regimen offers a good survival rate in breast cancer patients with more than three positive axillary lymph nodes. When these patients are carefully managed, the morbidity and mortality related to the treatment are low.

Influence of renal function on the pharmacokinetics of cerivastatin in normocholesterolemic adults

OBJECTIVE

The influence of impaired renal function on the pharmacokinetics of single and multiple doses of cerivastatin was evaluated in this nonrandomized, non-blinded, 7-day, multiple-dose study.

METHODS

Thirty-five adults between the ages of 21 years and 75 years with normal renal function (CL(CR) >90 ml/min/1.73 m2, n = 9), or patients with either mild (CL(CR) 61 ml/min/1.73 m2 to < or =90 ml/min/1.73 m2, n = 9), moderate (CL(CR) 30 ml/min/1.73 m2 to < or =60 ml/ min/1.73 m2, n = 8), or severe (CL(CR) <30 ml/min/ 1.73 m2, but not on dialysis, n = 9) renal impairment were given cerivastatin 0.3 mg daily each evening for 7 days. The steady-state pharmacokinetics of cerivastatin, including the area under the concentration-time curve (AUC)0-24, peak plasma concentration (Cmax), time to reach Cmax (tmax) and elimination half-life (t1/2), were determined on day 1 and day 7. The logarithm of the pharmacokinetic variables was analyzed using analysis of variance (ANOVA). Safety assessments included physical examination, fundoscopy, vital signs, electrocardiogram (ECG), adverse events, and laboratory safety indices.

RESULTS

The day-1 AUC in patients with mild renal impairment was similar to that of patients with normal function (19.6 microg/h/l vs 19.2 microg/h/l, respectively). However, the AUC for cerivastatin patients with moderate or severe renal impairment was 40-60% higher (30.8 microg/h/l and 29.0 microg/h/l, respectively). Cmax values for patients with normal, mild, moderate, and severe renal impairment were 3.3, 3.4, 4.6, and 5.2 microg/l, respectively. This modest increase in plasma cerivastatin levels is nearly equivalent to a 0.4-mg daily dose, which has been recently approved in the United States. The mean t1/2 of cerivastatin was less than 4.5 h in all patients, indicating that renal dysfunction did not promote cerivastatin accumulation. This observation was confirmed by the finding that the cerivastatin plasma levels on day 1 and day 7 were similar in all patient groups. Furthermore, the mean AUC and Cmax values for both demethylated and hydroxylated cerivastatin were similar in the patients with the most severe renal dysfunction to the corresponding values in healthy subjects. Cerivastatin was well tolerated in all patients irrespective of renal function. Adverse events were observed in 37% of the subjects; nearly all were mild and generally of short duration, and most resolved without intervention. Incidence of adverse events was similar across all three renal groups and the control group. There were no clinically significant laboratory changes other than those consistent with renal disease.

CONCLUSION

This study demonstrates that dosage adjustment of the daily 0.3-mg cerivastatin dose in patients with significant renal impairment is likely unnecessary.

Synthesis and biological evaluation of 1,3-oxathiolane 5-azapyrimidine, 6-azapyrimidine, and fluorosubstituted 3-deazapyrimidine nucleosides

(2R,5S)-5-Amino-2-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]- 1,2,4-triazine-3(2H)-one (8) and (2R,5R)-5-amino-2-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-1,2,4-tr iazine-3(2H)-one (9) have been synthesized via a multi-step procedure from 6-azauridine. (2R,5S)-4-Amino-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]-1,3, 5-triazine-2(1H)-one (11) and (2R,5R)-4-amino-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]- 1,3,5-triazine-2(1H)-one (12), and the fluorosubstituted 3-deazanucleosides (19-24) have been synthesized by the transglycosylation of (2R,5S)-1-[2-[[(tert-butyldiphenylsilyl) oxy]methyl]-1,3-oxathiolan-5-yl] cytosine (2) with silylated 5-azacytosine and the corresponding silylated fluorosubstituted 3-deazacytosines, respectively, in the presence of trimethylsilyl trifluoromethanesulfonate as the catalyst in anhydrous dichloroethane, followed by deprotection of the blocking groups. These compounds were tested in vitro for cytotoxicity against L1210, B16F10, and CCRF-CEM tumor cell lines and for antiviral activity against HIV-1 and HBV.

Primer system for single cell detection of double mutation for Tay-Sachs disease

PURPOSE

Nearly 100% of infantile Tay-Sachs disease is produced by two mutations occurring in the alpha chain of the lysosomal enzyme beta-N-acetylhexosaminidase (HEXA) in the Ashkenazi Jewish population. Although others have described primer systems used to amplify both sites simultaneously, few discuss the allele dropout problems inherent in this test. Our goal was to construct a more robust test enabling stronger signal generation for single cell preimplantation genetic diagnosis and to investigate the occurrence of allele dropout.

METHODS

New nested primers were designed to optimize detection of both major Tay-Sachs mutations. Four hundred fifty-seven single cells, including normal cells and those carrying mutations of either the 4bp insertion exon 11 or splice-site intron 12 defects, were used to screen a new primer system.

RESULTS

Based on PCR amplified product analysis, total efficiency of amplification was 85.3%, (390/457). The allele dropout rate for the 4bp insertion mutation in exon 11 and splice-site mutation in intron 12 was 4.8% and 5.8%, respectively.

CONCLUSIONS

Multiple mutation detection and analysis within the Tay-Sachs disease gene (HEXA) is possible using single cells for clinical preimplantation genetic diagnosis. Alternative PCR primers and conditions offer various methods for developing systems compatible to specific program requirements.

Sulfation of environmental estrogen-like chemicals by human cytosolic sulfotransferases

To investigate whether sulfation, a major Phase II detoxification pathway in vivo, can be employed as a means for the inactivation/disposal of environmental estrogens, recombinant human cytosolic sulfotransferases were prepared and tested for enzymatic activities with bisphenol A, diethylstilbestrol, 4-octylphenol, p-nonylphenol, and 17alpha-ethynylestradiol as substrates. Of the seven recombinant enzymes examined, only SULT1C sulfotransferase #1 showed no activities toward the environmental estrogens tested. Among the other six sulfotransferases, the simple phenol (P)-form phenol sulfotransferase and estrogen sulfotransferase appeared to be considerably more active toward environmental estrogens than the other four sulfotransferases. Metabolic labeling experiments revealed the sulfation of environmental estrogens and the release of their sulfated derivatives by HepG2 human hepatoma cells. Moreover, sulfated environmental estrogens appeared to be incapable of penetrating through the HepG2 cell membrane.

Extensive surface phenotyping of alveolar macrophages in interstitial lung disease

There is increasing evidence implicating activated macrophages in the pathogenesis of interstitial and other lung diseases. We investigated whether there was a unique pattern of cell surface expression that constituted a disease-specific phenotype on alveolar macrophages from patients with interstitial lung disease (ILD). Macrophage cell surface receptor expression of 19 selected markers was assessed by indirect immunofluorescence and flow cytometry in bronchoalveolar lavage (BAL) fluids from patients with idiopathic pulmonary fibrosis (IPF, n = 4), scleroderma (SCL-ILD, n = 14), mild asthma (n = 7), allergy without asthma (n = 2), and normal subjects (n = 9). There was increased expression of adhesion receptors (CD11c, CD29, CD36, CD44, CD49e, CD54), receptors involved in signal transduction and/or inflammation (CD13, CD45, CD53), and other markers (CD9, CD52, CD71, CD98, HLA Class I) on macrophages from ILD patients compared to the non-ILD group. Most markers upregulated on macrophages in ILD were significantly inversely correlated with clinical parameters of disease activity such as FEV(1), FVC, and DL(CO) and positively correlated with numbers of BAL neutrophils and eosinophils. Increased expression of several cell surface markers suggests that activated alveolar macrophages may contribute to the pathophysiology of IPF and SCL-ILD.

Prediction of programmed-temperature retention values of naphthas by artificial neural networks

It is proposed for the first time a method of prediction of the programmed-temperature retention times of components of naphthas in capillary gas chromatography using artificial neural networks. People are used to predict the programmed-temperature retention time using many formulas such as the integral formula, which requires that four parameters must be determined by calculation or experiments. However the results obtained by the formula are not so good to meet the demand of industry. In order to predict retention time accurately and conveniently, artificial neural networks using five-fold cross-validation and leave-20%-out methods have been applied. Only two parameters: density and isothermal retention index were used as input vectors. The average RMS error for predicted values of five different networks was 0.18, whereas the RMS error of predictions by the integral formula was 0.69. Obviously, the predictions by neural networks were much better than predictions by the formula, and neural networks need fewer parameters than the formula. So neural networks can successfully and conveniently solve the problem of predictions of programmed-temperature retention times, and provide useful data for analysis of naphthas in petrochemical industry.

Involvement of cyclin-dependent kinase activities in CD437-induced apoptosis

A novel synthetic retinoid, 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437), is a selective ligand of the RARgamma nuclear receptor. We examined the in vitro effects of CD437 and found that CD437 induces S phase arrest within 24 to 48 h, followed by cell death, in the p53-negative Hep3B and the p53-positive HepG2 human hepatoma cell lines. Based on observations of cellular and nuclear fragmentation, chromatin condensation, and DNA fragmentation, the CD437-mediated cell-killing effect appears to be due to apoptosis. On morphological examination, a number of CD437-treated cells were found to have increased 5- to 10-fold in size and persisted as single giant cells without cell division, while the remainder underwent nuclear division (multiple nuclei) but were unable to complete cytokinesis, and finally all died by apoptosis. In HepG2 cells that possessed wild-type p53, CD437-induced S phase arrest and apoptosis were accompanied by the up-regulation of cyclin A, cyclin B, p53, p21(CIP1/Waf1), Bad, and Bcl-Xs proteins and by a decrease in Bcl-2 protein levels. In Hep3B cells, CD437-mediated S phase arrest and apoptosis were also associated with a concomitant up-regulation of cyclin A, cyclin B, Bad, and Bcl-Xs. However, Hep3B cells did not express p53 or Bcl-2 messages. Olomoucine and roscovitine, the potent p34(cdc2) and CDK2 inhibitors, effectively blocked CD437-mediated cyclin A- and B-dependent kinase activation and prevented CD437-induced cell death. Furthermore, antisense oligonucleotide complementary to cyclin A and B mRNA significantly rescued CD437-induced apoptosis. These findings suggest that activation of cyclin A- and B-dependent kinases is a critical determinant of apoptotic death mediated by CD437.

Computer-aided development of a high-performance liquid chromatographic method for the determination of hydroxyanthraquinone derivatives in Chinese herb medicine rhubarb

With computer simulation predicting separation in reversed-phase gradient elution, a method to separate and determine five hydroxyanthraquinone derivatives having a wide range of polarity in extract of Chinese herbal medicine rhubarb has been developed. The software DryLab was used to model the retention behavior of the compounds as a function of gradient conditions, based on data from two scouting gradient runs. Under the optimized conditions, i.e. column, Zorbax RX-C18, 5 microm, 15x0.46 cm; solvent A, 36 mM triethylamine phosphate (TEAP), pH=2.5; solvent B, ACN; gradient, 36/36/80/80% B at 0/5.5/20.5/25.5 min; flow-rate, 1.00 ml/min; temperature, ambient, the method was successfully applied to monitor the quality of rhubarb from different sources. The effect of sample preparation procedures on extraction efficiency was also examined.

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone; 3-AP): an inhibitor of ribonucleotide reductase with antineoplastic activity

The enzyme RR catalyzes the conversion of ribonucleoside diphosphates to their deoxyribonucleotide counterparts. RR is critical for the generation of the cytosine, adenine, and guanine deoxyribonucleotide 5'-triphosphate building blocks of DNA, which are present in cells as exceedingly small intracellular pools. Therefore, interference with the function of RR might well result in an agent with significant antineoplastic activity, particularly against rapidly proliferating tumor cells. HUr is the only inhibitor of RR in clinical usage; this agent, however, is a relatively poor inhibitor of the enzyme and has a short serum half-life. Consequently, HUr is a relatively weak anticancer agent. In an effort to develop a more potent inhibitor of RR with utility as an anticancer agent, we have synthesized 3-AP and demonstrated (a) potent inhibition of L1210 leukemia cells in vitro, (b) curative capacity for mice bearing the L1210 leukemia, (c) marked inhibition of RR, and (d) sensitivity of HUr-resistant cells to 3-AP. These findings collectively demonstrate the clinical potential of 3-AP as an antineoplastic agent.

Pharmacodynamics, safety, tolerability, and pharmacokinetics of the 0.8-mg dose of cerivastatin in patients with primary hypercholesterolemia

Cerivastatin is a third generation hydroxy-methyl-glutaryl-Co-enzyme A (HMG-CoA) reductase inhibitor proven to lower low-density lipoprotein (LDL) cholesterol 28% to 31% in patients with primary hypercholesterolemia when given at 0.3 mg/day. This study evaluates the safety, tolerability, pharmacodynamics, and pharmacokinetics of cerivastatin 0.8 mg once daily for 4 weeks. In this randomized, double-blind, placebo-controlled parallel group trial conducted at 2 study centers, 41 patients (63% women) with primary hypercholesterolemia were placed on an American Heart Association Step 1 diet for 4 weeks. Single-blind placebo was administered for the final 2 weeks, before randomization. Patients received cerivastatin 0.8 mg (n = 28) or placebo (n = 13) once each evening for 28 days. Cerivastatin at 0.8 mg daily was well tolerated. No discontinuations occurred during the study. Adverse events were mild and transient. One cerivastatin-treated patient experienced asymptomatic creatinine kinase, 8x the upper limit of normal (ULN) elevation on the last day of the study, which resolved 6 days after the completion of the study. Cerivastatin 0.8 mg daily significantly reduced LDL cholesterol compared with placebo (-44.0 +/- 2.0% vs 2.2 +/- 2.8%, p <0.0001); total cholesterol (-30.8 +/- 1.4% vs 2.6 +/- 2.1%, p <0.0001), triglycerides (-11.2 +/- 5.9% vs 15.9 +/- 8.6%, p <0.02), but did not significantly alter high-density lipoprotein (HDL) cholesterol (3.2 +/- 2.1% vs -1.2 +/- 3.1%, p = NS). The pharmacokinetics of the 0.8-mg dose revealed dose proportional elevations in the 24-hour area under the curve and maximum plasma concentration relative to 0.3- and 0.4-mg doses with no change in time to maximum concentration or the elimination half-life in plasma. The increased efficacy and lack of clinically significant laboratory abnormalities or adverse events demonstrates a need for a large long-term study to confirm the safety and efficacy of this dose of cerivastatin.

Oral bioequivalence of three ciprofloxacin formulations following single-dose administration: 500 mg tablet compared with 500 mg/10 mL or 500 mg/5 mL suspension and the effect of food on the absorption of ciprofloxacin oral suspension

The oral bioequivalence and tolerability of two ciprofloxacin formulations (tablet and suspension) and the effect of food on the absorption of ciprofloxacin oral suspension were investigated. Sixty-eight young, healthy male subjects participated in two separate, randomized, crossover studies. In study 1, ciprofloxacin as a single 500 mg tablet or as 500 mg/10 mL oral suspension was administered in a fasted state on day 1. In study 2, subjects participated in a three-way crossover study in which ciprofloxacin suspension was administered as 500 mg/10 mL in a fasted state, or 500 mg/10 mL with food, or 500 mg/5 mL in a fasted state. Plasma ciprofloxacin concentrations were measured by high-performance liquid chromatography. Standard pharmacokinetic parameters were estimated using non-compartmental methods. In study 1, geometric mean Cmax values of ciprofloxacin following the single 500 mg tablet and 500 mg/10 mL suspension doses were 2.36 and 2.18 mg/L, respectively; corresponding geometric mean t(max) values were 1.1 and 1.6 h, respectively. Geometric mean AUC(0-infinity) values were 12.0 and 11.8 mg x h/L, respectively. In study 2, geometric least squares mean Cmax values following ciprofloxacin 500 mg/10 mL and 500 mg/5 mL suspension during fasted conditions were 1.54 and 1.59 mg/L, respectively. Corresponding geometric least squares mean AUC(0-infinity) values were 7.3 and 8.0 mg x h/L. Administration of ciprofloxacin 500 mg/10 mL suspension, in either a fasted or fed state, was not associated with significant changes in Cmax (1.54 mg/L for fasted vs 1.37 mg/L for fed) or AUC(0-infinity) values (7.28 mg x h/L for fasted vs 8.19 mg x h/L for fed). Each ciprofloxacin formulation was well tolerated for the duration of each study. These studies demonstrated bioequivalence between ciprofloxacin 500 mg tablet and two strengths of ciprofloxacin suspension (500 mg/10 mL and 500 mg/5 mL). Bioavailability was unaltered by food.

Bacterial expression, purification, and characterization of a novel mouse sulfotransferase that catalyzes the sulfation of eicosanoids

Analysis of the nucleotide sequence of a recently cloned mouse sulfotransferase cDNA (clone 679153) revealed the presence in its 3'-untranslated sequence of an AT-rich region which contains four ATTTA motifs and an TTATTTAT-like sequence, commonly found among those encoding inflammation-related proteins. The recombinant enzyme expressed in Escherichia coli and purified to near electrophoretic homogeneity displayed strong sulfotransferase activities toward various prostaglandins, thromboxane B2, and leukotriene E4. These results mark the first discovery of the sulfation of eicosanoids catalyzed by a distinct sulfotransferase.

Structural identification of sulfated tyrosine in human urine

A reliable HPLC method was used for the identification of positional isomerism and stereoisomerism of sulfated tyrosine residues in human urine. Upon separation of human urine by ion-pair HPLC on a reverse-phase column, p-tyrosine-O-sulfate (p-TyrS) was identified. Differentiation of the L and D forms was done by using a column with a chiral stationary phase. It was concluded that L-p-tyrosine (L-p-Tyr) which is the predominant tyrosine isomer in the human body, was sulfated and excreted in human urine as a normal constituent. The sulfated forms of D-p-Tyr and m-Tyr could not be detected under these analytical conditions.

Synthesis of 2'-methylene-substituted 5-azapyrimidine, 6-azapyrimidine, and 3-deazaguanine nucleoside analogues as potential antitumor/antiviral agents

2'-Deoxy-2'-methylene-6-azauridine (5) and 2'-deoxy-2'-methylene-6-azacytidine (8) have been synthesized via a multi-step procedure from 6-azauridine. 2'-Deoxy-2'-methylene-5-azacytidine (14a) and 2'-deoxy-2'-methylene-3-deazaguanosine (19a) and their corresponding alpha-anomers (14b and 19b) have been synthesized by the transglycosylation of 3',5'-O-(1,1,3,3- tetraisopropyldisiloxane-1,3-diyl)-2'-deoxy-2'-methyleneu ridine (12) with silylated 5-azacytosine and silylated N2-palmitoyl-3-deazaguanine, respectively, in the presence of trimethylsilyl trifluoromethanesulfonate as the catalyst in anhydrous dichloroethane, followed by separation of the isomers and deprotection of the blocking groups. These compounds were tested for cytotoxicity against B16F10, L1210, and CCRF-CEM tumor cell lines and for antiviral activity against HIV-1, HSV-1, and HSV-2.

Molecular cloning, expression, and characterization of novel human SULT1C sulfotransferases that catalyze the sulfonation of N-hydroxy-2-acetylaminofluorene

Upon sulfonation, carcinogenic hydroxyarylamines such as N-hydroxy-2-acetylaminofluorene (N-OH-2AAF) can be further activated to form ultimate carcinogens in vivo. Previous studies have shown that a SULT1C1 sulfotransferase is primarily responsible for the sulfonation of N-OH-2AAF in rat liver. In the present study, two novel human sulfotransferases shown to be members of the SULT1C sulfotransferase subfamily based on sequence analysis have been cloned, expressed, and characterized. Comparisons of the deduced amino acid sequence encoded by the human SULT1C sulfotransferase cDNA 1 reveal 63.7, 61.6, and 85.1% identity to the amino acid sequences of rat SULT1C1 sulfotransferase, mouse SULT1C1 sulfotransferase, and rabbit SULT1C sulfotransferase. In contrast, the deduced amino acid sequence of the human SULT1C sulfotransferase 2 cDNA displays 62.9, 63.1, 63.1, and 62.5% identity to the amino acid sequences of the human SULT1C sulfotransferase 1, rat SULT1C1 sulfotransferase, mouse SULT1C1 sulfotransferase, and rabbit SULT1C sulfotransferase. Recombinant human SULT1C sulfotransferases 1 and 2, expressed in Escherichia coli and purified to near electrophoretic homogeneity, were shown to cross-react with the antiserum against the rat liver SULT1C1 sulfotransferase and exhibited sulfonating activities with N-OH-2AAF as substrate. Tissue-specific expression of these novel human SULT1C sulfotransferases were examined by employing the Northern blotting technique. The results provide a foundation for the investigation into the functional relevance of these new SULT1C sulfotransferases in different human tissues/organs.

Clonal disease of natural killer large granular lymphocytes in Taiwan

Lymphoproliferative diseases of large granular lymphocytes (LDGL) may arise from either CD3+ T cells or CD3- natural killer (NK) cells. LDGL with clonal proliferation of large granular lymphocytes (LGL) is defined as LGL leukaemia. The number of patients with NK-LGL leukaemia reported is limited and the pathogenesis of the disease is not yet clear. From 1991 to 1998 six patients with cytogenetically proved clonal disease of NK-LGL were identified in our institute. All were seropositive for Epstein-Barr virus (EBV). EBV RNA or DNA could be detected in LGL from four patients by EBV in situ hybridization or Southern blot analysis. Most patients ran an aggressive clinical course and five died of the disease. Nonrandom clonal chromosomal abnormalities, including duplication of 1q, rearrangement at 3q and loss of chromosomes Y, 13 or 10, were noted in the six patients from this study and in eight from the literature. The implications of these recurrent cytogenetic aberrations in the development and progression of the disease deserve further studies.