Serum metabolomics reveals pathways and biomarkers associated with asthma pathogenesis.

BACKGROUND: Asthma is a chronic inflammatory disease caused by complex interactions of genetic, epigenetic, and environmental factors. For this reason, new approaches are required to clarify the pathogenesis of asthma by systemic review. OBJECTIVE: We applied a (1)H-NMR metabolomics approach to investigate the altered metabolic pattern in sera from patients with asthma and sought to identify the mechanism underlying asthma and potential biomarkers. METHOD: A global profile of sera from patients with asthma (n = 39) and controls (n = 26) was generated using (1)H-NMR spectroscopy coupled with multivariate statistical analysis. Endogenous metabolites in serum were rapidly measured using the target-profiling procedure. RESULTS: Multivariate statistical analysis showed a clear distinction between patients with asthma and healthy subjects. Sera of asthma patients were characterized by increased levels of methionine, glutamine, and histidine and by decreased levels of formate, methanol, acetate, choline, O-phosphocholine, arginine, and glucose. The metabolites detected in the sera of patients with asthma are involved in hypermethylation, response to hypoxia, and immune reaction. Furthermore, the levels of serum metabolites from patients with asthma correlated with asthma severity; in particular, lipid metabolism was altered in patients with lower forced expiratory volume in 1 s percentage (FEV(1)%) predicted values. In addition, potential biomarkers showed strong predictive power in ROC analysis, and the presence of asthma in external validation models was predicted with high accuracy (90.9% for asthma and 100% for control subjects). CONCLUSION & CLINICAL RELEVANCE: These data showed that (1)H-NMR-based metabolite profiling of serum may be useful for the effective diagnosis of asthma and a further understanding of its pathogenesis.

Synthesis and biological evaluation of novel A-ring modified hexacyclic camptothecin analogues.

Eleven A-ring modified hexacyclic analogues of camptothecin (CPT) containing a 1,4-oxazine ring were synthesized from 10-hydroxycamptothecin (11a) and 7-ethyl-10-hydroxycamptothecin (3) (SN-38) in four to five steps and were subjected to the biological tests such as cytotoxicity, topoisomerase I (Topo I) inhibitory activity, acetylcholinesterase (AChE) inhibition, and stability in human plasma. Four compounds 15a, 15b, 16a, and 16c were about 2-fold more potent than topotecan and as potent as CPT toward human cancer cell lines A549, H128, WiDr, MKN45, SK-OV-3, and SK-BR-3 in vitro, even though the most active compound 15b was slightly less potent than SN-38. The potency of Topo I inhibition of these compounds showed relatively good correlation with their cytotoxicity. Most of the compounds exhibited AChE inhibitory activity weaker (9 +/- 2 to 20 +/- 3%) than CPT (23 +/- 5%) or topotecan (20 +/- 4%) and similar to SN-38 (13 +/- 2%), indicating that they might have little effect on causing early diarrhea. The stability of lactone forms of these compounds in human plasma seemed to be much higher than that of CPT and similar to that of topotecan but lower than that of SN-38. Among the new hexacyclic CPT analogues, compound 15b showed higher antitumor activity against human tumor xenograft, WiDr, in nude mice compared to that of SN-38. The most promising compound 15b has been selected for further development.

The effect of fundal pressure at Caesarean section on maternal haemodynamics.

In 20 women undergoing Caesarean section, we determined brachial arterial blood pressure, heart rate and cardiac output (using an oesophageal Doppler probe) just after uterine incision and during the application of extra-abdominal uterine fundal pressure to facilitate delivery. Mean (SD) systolic aortic flow time (354.3 (35.4) ms), cardiac output (3.85 (0.68) l.min(-1)), heart rate (80.6 (14.2) beats.min(-1)) and blood pressure (84.7 (12.1) mmHg) decreased when fundal pressure was applied compared with after uterine incision (397.6 (31.6) ms, 4.69 (0.78) l.min(-1), 95.1 (14.0) beats.min(-1)and 100.3 (12.0) mmHg, respectively; p < 0.05). Peak velocity and stroke distance of the aortic flow when fundal pressure was applied was similar to after uterine incision. The mothers and babies were not observed to be clinically compromised. The results suggest that applying fundal pressure to facilitate Caesarean delivery produces significant haemodynamic effects but the impact of these effects may be clinically insignificant.

Aminoglycoside binding to human and bacterial A-Site rRNA decoding region constructs.

The 16S bacterial ribosomal A-site decoding rRNA region is thought to be the pharmacological target for the aminoglycoside antibiotics. The clinical utility of aminoglycosides could possibly depend on the preferential binding of these drugs to the prokaryotic A-site versus the corresponding A-site from eukaryotes. However, quantitative aminoglycoside binding experiments reported here on prokaryotic and eukaryotic A-site RNA constructs show that there is little in the way of differential binding affinities of aminoglycosides for the two targets. The largest difference in affinity is 4-fold in the case of neomycin, with the prokaryotic A-site construct exhibiting the higher binding affinity. Mutational studies revealed that decoding region constructs retaining elements of non-Watson-Crick (WC) base pairing, specifically bound aminoglycosides with affinities in the muM range. These studies are consistent with the idea that aminoglycoside antibiotics can specifically bind to RNA molecules as long as the latter have non-A form structural elements allowing access of aminoglycosides to the narrow major groove.

Synthesis and evaluation of 2-amino-9-(3-acyloxymethyl-4-alkoxycarbonyloxybut-1-yl)purines and 2-amino-9-(3-alkoxycarbonyloxymethyl-4-alkoxycarbonyloxybut-1- yl)purines as potential prodrugs of penciclovir.

A series of 2-amino-9-(3-acyloxymethyl-4-alkoxycarbonyloxybut-1-yl)purin es (1-8) and 2-amino-9-(3-alkoxycarbonyl-oxymethyl-4-alkoxycarbonyloxybut -1-yl)purines (9-12) were synthesized as potential prodrugs of penciclovir. Treatment of 6-deoxypenciclovir with trimethyl orthoacetate or triethyl orthopropionate (1.2 equiv) in DMF in the presence of p-TsOH.H2O (0.1 equiv) followed by quenching with excess H2O gave the corresponding mono-O-acetyl or mono-O-propionyl compound, 17 or 18, in excellent yields of 95 and 92%, respectively. Reactions of 17 or 18 with an appropriate alkyl (Me, Et, n-Pr, and i-Pr) 4-nitrophenyl carbonate (1.2 equiv) in pyridine in the presence of a catalytic amount of DMAP (0.1 equiv) at 80 degrees C afforded the monoacyl, monocarbonate derivatives of 6-deoxypenciclovir, 1-8, in 86 94% yields. Similar reactions of 6-deoxypenciclovir with 2.1 equiv of alkyl 4-nitrophenyl carbonate produced the dicarbonate derivatives 9 12 in 81-83% yields. Of the prodrugs tested in rats, 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)purine (4) achieved the highest mean urinary recovery of penciclovir (36%), followed in order by compounds 2 (35%), 6 (35%), 7 (34%), 10 (34%), 8 (32%), 3 (32%), and famciclovir (31%). The mean urinary recovery of penciclovir and concentrations of penciclovir in the blood from 4 in mice were also slightly higher than those from famciclovir. The in vivo antiviral efficacy of 4 in HSV-1-infected normal BALB/c mice was higher than those of famciclovir and valaciclovir in terms of mortality (100, 80, and 40%) and mean survival time ( > 21, 13+/-5.0 (SEM), and 13+/-1.6 days). Compound 4 demonstrated an effective anti-hepadnaviral response with intrahepatic viral load being reduced by 90%, the viral supercoiled DNA levels reduced by 70% and Pre-S expression inhibited by 30% against duck hepatitis B virus (DHBV) in vivo, and did not cause any significant hepatotoxicity after 4 weeks of treatment.

Synthesis and phosphodiesterase inhibitory activity of new sildenafil analogues containing a carboxylic acid group in the 5'-sulfonamide moiety of a phenyl ring.

New sildenafil analogues possessing a carboxylic acid group in the 5'-sulfonamide of the phenyl ring, 9a-l, were prepared from the readily available starting compounds 6a-b and cyclic amines 3-5 in a three-step sequence. In the enzyme assays, it has been shown that all the target compounds 9a-l proved to be more potent in inhibiting phosphodiesterase type 5 (PDE5) than sildenafil by 4-38-fold. The effects on the IC(50) values were investigated by varying the alkoxy group (R) of the phenyl ring, the sulfonamide type (X), and the length of the methylene chain linking the carboxylic acid, and the results were discussed in detail. From this study, we have clearly demonstrated that introduction of a carboxylic acid group to the 5'-sulfonamide moiety of the phenyl ring greatly enhanced PDE5 inhibitory activity, probably by mimicking the phosphate group of cGMP. The piperidinyl propionic acid derivative 9i, which showed the highest PDE5 inhibitory activity and comparable to better selectivity over PDE isozymes in comparison with sildenafil, has been selected for more detailed biological investigations.

Synthesis and phosphodiesterase 5 inhibitory activity of new 5-phenyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one derivatives containing an N-acylamido group phenyl ring.

New sildenafil analogues with an N-acylamido group at the 5'-position of the phenyl ring, 6a--e, were prepared from the readily available starting compound 2 in four straightforward steps. Enzyme assays demonstrated that all the target compounds 6a-e showed higher PDE5 inhibitory activities than sildenafil. It was observed that the PDE5 inhibitory activity was enhanced as the chain length of R group increased, but introduction of the branched alkyl groups such as isopropyl (6d) and cyclohexyl (6e) resulted in the drop of potency compared with 6c. In particular the N-butyrylamido derivative 6c exhibited the highest PDE5 inhibitory activity, and was about 6-fold more potent than sildenafil. However, all the compounds exhibited somewhat weak selectivity (1--3-fold) over PDE6, indicating that the compounds 6a--e have intrinsically lower selectivity than sildenafil.

General pharmacology of the new antiviral agent SK 1899.

The general pharmacological properties of 2-amino-9-(3-acetoxymethyl-4-isopropoxycarbonyloxybut-1-yl)purine (CAS 247081-81-8, SK 1899), a new potential antiviral agent, were investigated in mice, rats, guinea pigs, rabbits, and dogs. The oral administration of 50, 150, and 500 mg/kg of SK 1899 had no effects on the central nervous system except that it slightly increased the spontaneous locomotor activity in mice at a dose of 500 mg/kg. SK 1899 did not disturb either the spontaneous motility or contractor-induced contraction of the isolated organs such as guinea pig ileum, rat uterus, guinea pig vas deferens, and guinea pig trachea at concentrations up to 10(-4) mol/l. It slightly increased the contractile force in the isolated guinea pig atrium at a concentration of 10(-4) mol/l. Following intravenous infusion of 5, 15, and 50 mg/kg of SK 1899 to anesthetized dogs, it did not change the mean arterial pressure, heart rate, left ventricular systolic pressure (LVSP), and respiratory rate, while it slightly increased the left ventricular positive dP/dtmax (LV + dP/dtmax) at a dose of 50 mg/kg. SK 1899 did not induce any significant changes in the intestinal charcoal meal transit in mice, basal gastric juice secretion in rats, and renal function in rats. It did not affect the blood coagulation system and phenolsulfonphthalein secretion in rats. These findings suggest that SK 1899 has a very low potential to induce any adverse pharmacological effects at the doses showing antiviral activity.

Synthesis and phosphodiesterase 5 inhibitory activity of novel phenyl ring modified sildenafil analogues.

New sildenafil analogues containing an ether ring fused into the phenyl moiety, 6a--d and 7a--d, were efficiently synthesized from the readily available starting materials, 1a--d and 2, in five steps. Ab initio calculations indicated that introduction of a cyclic ether to the phenyl group might enhance the co-planarity of the molecule. The torsional angles were calculated to be 2--3 degrees for the 5-membered cyclic ether derivatives, 6a, 6c, 7a, and 7c, and 12--16 degrees for the 6-membered ones, 6b, 6d, 7b, and 7d. On the other hand, sildenafil showed the least co-planarity with the torsional angle of 23 degrees compared with the target compounds, 6a--d and 7a--d. In the enzyme assay, however, the in vitro PDE 5 inhibitory activity was found out to be inversely related to the degree of co-planarity. In other words, the least planar sildenafil showed the highest activity, and the most planar 5-membered cyclic ether derivatives were least active by 100--200-fold compared with sildenafil. Our study clearly demonstrated that the open chain 2'-alkoxy group of the phenyl ring, although less effective for inducing the co-planarity, seemed to act as a much better lipophilic requirement than the cyclic alkoxy moiety.