Effects of CRP infusion on endothelial function and coagulation in normocholesterolemic and hypercholesterolemic subjects

C-reactive protein (CRP) has been suggested to exert direct adverse effects on the vasculature in experimental setups, including endothelial dysfunction and proinflammatory changes. Here, we assessed the consequences of 1.25 mg/kg highly purified recombinant human CRP, administered as an intravenous bolus, in six patients with familial hypercholesterolemia (FH) and six normocholesterolemic subjects. Endothelium-dependent and -independent vasoreactivity to serotonin and nitroprusside, respectively, were assessed using venous occlusion plethysmography before and after CRP infusion. For biochemical analyses, blood was drawn at different time points. At baseline, FH patients showed blunted endothelium-dependent vasodilation (maximum, 89.2 +/- 30.0% vs. 117.7 +/- 13.1% in normolipidemic subjects; P = 0.037). Procoagulant activity was also higher in FH patients, illustrated by increased prothrombin fragment 1+2 (F(1+2)) levels (P = 0.030) and plasminogen activator inhibitor type-1 (PAI-1) activity (P = 0.016). Upon CRP challenge, endothelium-dependent vasodilator capacity further deteriorated in FH patients (P = 0.029), whereas no change in vascular reactivity was observed in normolipidemic subjects. Additionally, coagulation activation was augmented in FH patients compared with normolipidemic subjects (P = 0.009 for F(1+2) levels; P = 0.018 and P = 0.003 for PAI-1 antigen and activity, respectively). No difference in inflammatory responses was observed between groups. In hypercholesterolemic patients, CRP aggravates endothelial dysfunction and also evokes augmented procoagulant responses. These findings suggest that particularly in hypercholesterolemia, CRP-lowering strategies should be considered in addition to LDL reduction.     

Oral vaccines: new needs, new possibilities

Vaccination is an important tool for handling healthcare programs both in developed and developing countries. The current global scenario calls for a more-efficacious, acceptable, cost-effective and reliable method of immunization for many fatal diseases. It is hoped that the adoption of oral vaccines will help to provide an effective vaccination strategy, especially in developing countries. Mucosal immunity generated by oral vaccines can serve as a strong first line of defense against most of the pathogens infecting through the mucosal lining. Advances in elucidating the mechanism of action of oral vaccines will facilitate the design of more effective, new generation vaccines. There are promising developments in the use of different agents to effectively deliver the vaccine candidate. It is hoped that ongoing research may be able to set another cardinal point, after polio vaccine, in eradicating infectious diseases.     

Purification of β-galactosidase from Erythrina indica: Involvement of tryptophan in active site

β-Galactosidase (EC: 3.2.1.23), one of the glycosidases detected in Erythrina indica seeds, was purified to 135 fold. Amongst the four major glycosidases detected β-galactosidase was found to be least glycosylated, and was not retained by Con-A CL Seralose affinity matrix. A homogenous preparation of the enzyme was obtained by ion-exchange chromatography, followed by gel filtration. The enzyme was found to be a dimmer with a molecular weight of 74 kDa and 78 kDa, by gel filtration and SDS-PAGE, respectively. The optimum pH and optimum temperature for enzyme activity were 4.4 and 50 °C, respectively. The enzyme showed a K_m value of 2.6 mM and V_max of 3.86 U/mg for p-nitrophenyl-β-D-galactopyranoside as substrate and was inhibited by Zn²⁺ and Hg²⁺. The enzyme activity was regulated by feed back inhibition as it was found to be inhibited by β-D-galactose. Chemical modification studies revealed involvement of tryptophan and histidine for enzyme activity. Involvement of tryptophan was also supported by fluorescence studies and one tryptophan was found to be present in the active site of β-galactosidase. Circular dichroism studies revealed 37% α helix, 27% β sheet and 38% random coil in the secondary structure of the purified enzyme.     

Characterization of α-mannosidase from Erythrina indica seeds and influence of endogenous lectin on its activity

α-mannosidase from Erythrina indica seeds is a Zn²⁺ dependent glycoprotein with 8.6% carbohydrate. The enzyme has a temperature optimum of 50 °C and energy of activation calculated from Arrhenius plot was found to be 23 kJ mol^− 1. N-terminal sequence up to five amino acid residues was found to be DTQEN (Asp, Thr, Gln, Glu, and Asn). In chemical modification studies treatment of the enzyme with NBS led to total loss of enzyme activity and modification of a single tryptophan residue led to inactivation. Fluorescence studies over a pH range of 3–8 have shown tryptophan residue to be in highly hydrophobic environment and pH change did not bring about any appreciable change in its environment. Far-UV CD spectrum indicated predominance of α-helical structure in the enzyme. α-Mannosidase from E indica exhibits immunological identity with α-mannosidase from Canavalia ensiformis but not with the same enzyme from Glycine max and Cicer arietinum. Incubation of E. indica seed lectin with α-mannosidase resulted in 35% increase in its activity, while no such activation was observed for acid phosphatase from E. indica. Lectin induced activation of α-mannosidase could be completely abolished in presence of lactose, a sugar specific for lectin.     

Synthesis, in vitro and in silico evaluation of l-tyrosine containing PPARalpha/gamma dual agonists

A novel series of l-tyrosine derivatives have been reported with potential PPARalpha/gamma dual agonistic activity. In vitro cell based PPARalpha/gamma transactivation studies have shown compound 4a and compound 4f to be the most potent PPARgamma and PPARalpha activators, respectively. Molecular docking studies performed on these series of compounds have complemented the experimental results and have led to interesting inferences.     

Studies on acyclic pyrimidines as inhibitors of mycobacteria

In vitro anti-mycobacterial activities of several 5-substituted acyclic pyrimidine nucleosides containing 1-(2-hydroxyethoxy)methyl and 1-[(2-hydroxy-1-(hydroxymethyl) ethoxy)methyl] acyclic moieties are investigated against three mycobacteria viz. Mycobacterium tuberculosis, Mycobacterium bovis, and Mycobacterium avium, which cause serious infections and mortality in healthy people as well as patients with AIDS. 1-(2-Hydroxyethoxy)methyl-5-(1-azido-2-haloethyl or 1-azidovinyl) analogs (4-7), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl]-5-decynyluracil (37), and 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl]-5-dodecynyluracil (38) exhibited significant in vitro anti-tubercular activity against these mycobacteria.     

Fine Mapping of Aroma QTLs in Basmati Rice (Oryza sativa L) on Chromosomes 3, 4 and 8

Aroma is one of the most important quality traits of basmati rice (Oryza sativa L) that leads to high consumer acceptance. Earlier three significant QTLs for aroma, namely aro3-1, aro4-1 and aro8-1, have been mapped on rice chromosomes 3, 4 and 8, respectively, using a population of recombinant inbred lines (RILs) derived from a cross between Pusa 1121 (a basmati quality variety) and Pusa 1342 (a non-aromatic variety). For fine mapping of these QTLs, 184 F₆ RILs were grown in the Kharif season of 2005 at New Delhi and Karnal, India. A total of 115 new SSR markers covering the three QTL intervals were designed and screened for parental polymorphism. Of these, 26 markers were polymorphic between parents, eight for the interval aro3-1, eight for the interval aro4-1 and ten for the interval aro8-1, thus enriching the density of SSR markers in these QTL intervals. Revised genetic maps were constructed by adding 23 of these new markers to the earlier map, by giving physical order of the markers in the pseudomolecules a preference. In the revised maps, the interval for QTL aro4-1 could not be improved further but QTL aro3-1 was narrowed down to an interval of 390 kbp from the earlier reported interval of 8.6 Mbp and similarly the QTL aro8-1 was narrowed down to a physical interval of 430 kbp. The numbers of candidate genes in the aro3-1 and aro8-1 intervals have now been reduced to 51 and 66, respectively. The badh2 gene on chromosome 8 was not associated with the aroma QTL on this chromosome.     

One pot synthesis of pyrimidine and bispyrimidine derivatives and their evaluation for anti-inflammatory and analgesic activities

A number of pyrimidine derivatives (1-10) have been synthesized by condensation of 4-isothiocyanato-4-methylpentan-2-one with furfurylamine, histamine, 1-(3-aminopropyl)imidazole, 1-(3-aminopropyl)-2-pyrrolidinone, 2-aminobenzonitrile and 3-isothiocyanatobutanal with 1-(3-aminopropyl)-2-pyrrolidinone and 2-hydrazinopyridine under different reaction conditions. Various bispyrimidine derivatives (11-15) were obtained by condensation of 4-isothiocyanato-4-methylpentan-2-one with 2,4,8,10-tetraoxaspiro[5,5]undecane3,9-dipropamine (11'), 1,4-bis(3-aminopropyl)piperazine (13'), 3,5-diamino 1,2,4-triazole (15') and 3-isothiocyanatobutanal with 2,4,8,10-tetraoxaspiro[5,5]undecane 3,9-dipropamine, 1,4-bis(3-aminopropyl)piperazine. All these compounds were characterized by correct FT-IR, (1)H NMR, MS and elemental analysis. These compounds were screened for anti-inflammatory and analgesic activities. Anti-inflammatory activity of 3 is comparable while analgesic activity was found to be better than that of standard drug.