N-(1-Benzylpyrrolidin-3-yl)arylbenzamides as potent and selective human dopamine D4 antagonists

A series of N-(1-benzylpyrrolidin-3-yl)arylbenzamides 8 has been prepared, and their structure-activity relationships studied. Potent ligands selective for human D(4) (hD(4)) over hD(2) and alpha(1) have been identified. One example was determined to be an antagonist in a cAMP assay, with an IC(50) of 1500 nM.     

Lactose biosensor based on Langmuir-Blodgett films of poly(3-hexyl thiophene)

An amperometric lactose biosensor was developed by immobilizing lactase (EC 3.2.1.23) and galactose oxidase (GaO) (EC 1.1.3.9) in Langmuir-Blodgett (LB) films of poly(3-hexyl thiophene) (P3HT)/stearic acid (SA) for estimation of lactose in milk and its products to prevent "lactose intolerance". The enzyme immobilized LB film was used as working electrode and platinum as reference electrode. The enzyme electrodes show a linearity 1-6 g/dL of lactose and have a shelf life more than 120 days. The reusability of electrode was found ten times with 3% loss in current response. The enzyme electrode was characterized by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and kinetic parameters such as pH, temperature and stability. The working electrode may be used for the estimation of lactose/galactose in food and biological fluids.     

Experimental myocardial necrosis in rats: Role of arjunolic acid on platelet aggregation,coagulation and antioxidant status

Arjunolic acid, a new triterpene and a potent principle from the bark of Terminalia arjuna, has been shown to provide significant cardiac protection in isoproterenol induced myocardial necrosis in rats. To further explore the mechanism of action of arjunolic acid, antiplatelet activity, anticoagulant assays, electrocardiographic changes, serum marker enzymes, antioxidant status, lipid peroxide and myeloperoxidase (MPO) have been measured and the results are compared with a potent cardioprotective drug, acetyl salicylic acid (ASA). Administration of isoproterenol produces electrocardiographic changes such as decreased R amplitude and increased ST segment elevation and has resulted in an increase in serum marker enzyme levels as well as a decrease in enzymatic and nonenzymatic antioxidant levels. Arjunolic acid at an effective dosage of 15 mg/kg body weight (pre and post treatment),when administered intraperitoneally (i.p.), effects a decrease in serum enzyme levels and the electrocardiographic changes get restored towards normalcy. Arjunolic acid treatment is also shown to prevent the decrease in the levels of superoxide dismutase, catalase, glutathione peroxidase, ceruloplasmin, -tocopherol, reduced glutathione (GSH), ascorbic acid, lipid peroxide, MPO and the cardioprotection is confirmed by the histopathological studies.This study shows that the cardioprotection of arjunolic acid pre and post treatment could possibly be due to the protective effect against the damage caused by myocardial necrosis.     

Evaluation of rabies virus neutralizing antibody titres induced by intramuscular inoculation of rabies DNA vaccine in mice and Bonnet monkeys (Macaca radiata)

A rabies DNA vaccine consisting of plasmid DNA expressing the rabies virus surface glycoprotein was injected (im) twice at two week interval to outbred swiss mice or Bonnet monkeys (Macaca radiata) and the levels of rabies virus neutralizing antibody (VNA) titres were examined over a one year period. In mice, the VNA titre was maintained above the minimum protective level (0.5 I.U./ml) up to 10 months after primary immunization, while in monkeys, the titre dropped below the protective level by 6 months. An anamnestic B cell response was seen in both mice and monkeys following the administration of a booster dose, 10 and 6 months after the primary immunization, respectively. These results indicate that im injection of rabies DNA vaccine induces VNA in nonhuman primates and mice unlike intradermal (id) immunization, which was shown to induce VNA only in mice but not in monkeys. This is the first report on the induction of VNA in nonhuman primates by im inoculation of rabies DNA vaccine.     

Ubiquitin-mediated proteolysis in learning and memory

Sensitization of defensive reflexes inAplysia is a simple behavioral paradigm for studying both short- and long-term memory. In the marine mollusk, as in other animals, memory has at least two phases: a short-term phase lasting minutes and a long-term phase lasting several days or longer. Short-term memory is produced by covalent modification of pre-existing proteins. In contrast, long-term memory needs gene induction, synthesis of new protein, and the growth of new synapses. The switch from short-term (STF) to long-term facilitation (LTF) inAplysia sensory neurons requires not only positive regulation through gene induction, but also the specific removal of several inhibitory proteins. One important inhibitory protein is the regulatory (R) subunit of the cAMP-dependent protein kinase (PKA). Degradation of R subunits, which is essential for initiating long-term stable memory, occurs through the ubiquitin-proteasome pathway.     

Roxburghinol,A 1,2-dihydroanthraquinone from the leaves of Cassia roxburghii

A new 1,2-dihydroanthraquinone, roxburghinol was isolated from the leaves of Cassia roxburghii. its structure was established as 1,2-dihydro-1,3,8-trihydroxy-2-methyl anthraquinone on the basis of physical and chemical evidence.     

(R)-3-(N-methylpyrrolidin-2-ylmethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives as high affinity h5-HT1B/1D ligands

A series of (R)-3-(N-methylpyrrolidin-2-ylmethyl)-5-(1,2,3,6-tetrahydropyridin-4-yl)-1H-indole derivatives (2) have been prepared using parallel synthesis, and their structure-activity relationship studied. High affinity human 5-HT(1B/1D) (h5-HT(1B/1D)) ligands have been identified.     

One-step metal-affinity purification of histidine-tagged proteins by temperature-triggered precipitation

The feature of elastin-like proteins (ELPs) to reversibly precipitate above their transition temperature was exploited as a general method for the purification of histidine (His)-tagged proteins. The principle of the single-step metal-affinity method is based on coordinated ligand-bridging between the modified ELPs and the target proteins. ELPs with repeating sequences of [(VPGVG)(2)(VPGKG)(VPGVG)(2)](21) were synthesized and the free amino groups on the lysine residues were modified by reacting with imidazole-2-carboxyaldehyde to incorporate the metal-binding ligands into the ELP bio- polymers. Biopolymers charged with Ni(2+) were able to interact with a His tag on the target proteins based on metal coordination chemistry. Purifications of two His-tagged enzymes, beta-D-galactosidase and chloramphenicol acetyltransferase, were used to demonstrate the utility of this general method and over 85% recovery was observed in both cases. The bound enzymes were easily released by addition of either EDTA or imidazole. The recovered ELPs were reused four times with no observable decrease in the purification performance.     

Mentha piperita (Linn.) leaf extract provides protection against radiation induced chromosomal damage in bone marrow of mice

Oral administration of M. piperita (1 g/kg body weight/day) before exposure to gamma radiation was found to be effective in protecting against the chromosomal damage in bone marrow of Swiss albino mice. Animals exposed to 8 Gy gamma radiation showed chromosomal aberrations in the form of chromatid breaks, chromosome breaks, centric rings, dicentrics, exchanges and acentric fragments. There was a significant increase in the frequency of aberrant cells at 6 hr after irradiation. Maximum aberrant cells were observed at 12 hr post-irradiation autopsy time. Further, the frequency of aberrant cells showed decline at late post-irradiation autopsy time. However, in the animals pretreated with Mentha extract, there was a significant decrease in the frequency of aberrant cells as compared to the irradiated control. Also significant increase in percentage of chromatid breaks, chromosome breaks, centric rings, dicentrics, exchanges, acentric fragments, total aberrations and aberrations/damaged cell was observed at 12 hr post-irradiation autopsy time in control animals, whereas Mentha pretreated irradiated animals showed a significant decrease in percentage of such aberrations. A significant decrease in GSH content and increase in LPO level was observed in control animals, whereas Mentha pretreated irradiated animals exhibited a significant increase in GSH content and decrease in LPO level but the values remained below the normal. The radioprotective effect of Mentha was also demonstrated by determining the LD(50/30) values (DRF = 1.78). The results from the present study suggest that Mentha pretreatment provides protection against radiation induced chromosomal damage in bone marrow of Swiss albino mice.     

The Drosophila SSL gene is expressed in larvae,pupae, and adults,exhibits sexual dimorphism,and mimics properties of the beta subunit of casein kinase II

Drosophila melanogaster casein kinase II (CKII) is composed of catalytic alpha and regulatory beta subunits that generate the alpha2beta2 holoenzyme. A two-hybrid screen of a Drosophila embryo library using CKIIalpha as bait has resulted in the isolation of multiple cDNAs encoding SSL, a CKIIbeta-like polypeptide. We demonstrate that CKIIbeta, beta', and SSL exhibit robust and comparable interaction with CKIIalpha. Residues in SSL that mediate interaction with CKIIalpha appear similar to those in CKIIbeta, and SSL forms homodimers and heterodimers with CKIIbeta or beta' as well. We have tested all known Drosophila CKIIbeta-like proteins for rescue of the ion-homeostasis defect of yeast lacking beta subunits and find that CKIIbeta and SSL complement, beta' has marginal function, and Stellate appears non-functional. We have used real-time RT-PCR to assess developmental expression, and find that CKIIbeta is robust and ubiquitous, whereas SSL is restricted to males (third-instar-larvae, pupae, and adults), but is nondetectable in females of the corresponding stages. These results indicate that SSL expression encompasses a greater developmental window than that previously suggested and may confer distinct functions to CKII in a sex-specific manner.