Bicyclic[4.1.0]heptanes as phenyl replacements for melanin concentrating hormone receptor antagonists

Melanin concentrating hormone (MCH) receptor antagonists have been proposed as potential treatments of obesity. MCH receptor antagonists with a biphenylamine subunit have been reported previously at Schering-Plough. Herein, we report the discovery of bicyclo[4.1.0]heptanes as replacements for the middle phenyl ring of the biphenylamine moiety in order to eliminate its potential mutagenic liability. Structure-activity relationships in this series were found to be very similar to those of the original biphenylamine series, suggesting that the two series have similar binding modes.     

Elasmobranch qPCR reference genes: a case study of hypoxia preconditioned epaulette sharks

Background  

Elasmobranch fishes are an ancient group of vertebrates which have high potential as model species for research into evolutionary physiology and genomics. However, no comparative studies have established suitable reference genes for quantitative PCR (qPCR) in elasmobranchs for any physiological conditions. Oxygen availability has been a major force shaping the physiological evolution of vertebrates, especially fishes. Here we examined the suitability of 9 reference candidates from various functional categories after a single hypoxic insult or after hypoxia preconditioning in epaulette shark (Hemiscyllium ocellatum).     

Development of sequence amplified characterized region (SCAR) markers of helicoverpa armigera: a new polymerase chain reaction-based technique for predator gut analysis

A method is described for the development of DNA markers for detection of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) in predator gut analysis, based on sequence characterized amplified regions (SCARs) derived from a randomly amplified polymorphic DNA (RAPD) band. A 1200-bp DNA fragment of H. armigera, absent in the predator band pattern and in other closely related prey species, was identified by RAPD analysis. This fragment was cloned and its extremes sequenced to design extended strand-specific 20-mer oligonucleotide primers. Three pairs of SCAR primers, which amplified three different DNA fragments, were used to study the effect of fragment length on detection of prey in the predator gut. Using the pair of primers that amplified the longest fragment of H. armigera DNA, a single band of 1100 bp was obtained, but its detection was not possible in the predator gut. Detection of the ingested prey was possible with the other two pairs of SCAR primers, obtaining bands of 600 and 254 bp, respectively. Detection of H. armigera DNA in the gut of the predator Dicyphus tamaninii was evaluated immediately after ingestion (t = 0) and after 4 h. Detection of H. armigera DNA after 4 h was only possible using the pair of primers that amplified the shortest fragment (254 bp). The test for specificity, using these last pair of primers, showed that H. armigera was the only species detected. The detection threshold was defined at a 1:8192 dilution of a H. armigera whole egg in all samples.     

1H-Pyrazolo-[3,4-c]cyclophepta[1,2-c]thiophenes: a unique structural class of dopamine D4 selective ligands

A series of novel 1H-pyrazolo-[3,4-c]cyclophepta[1,2-c]thiophenes was prepared and screened at selected dopamine receptor subtypes. Compound 4 (NGB 4420) displayed high affinity and selectivity (>100-fold) for the D(4) over D(2) and other CNS receptors. This compound was identified as a D(4) antagonist via its attenuation of dopamine agonist-induced GTPgamma(35)S binding at D(4) receptor.     

Trimetazidine improves left ventricular function in diabetic patients with coronary artery disease: a double-blind placebo-controlled study

Background

Patients with diabetic cardiomyopathy have an impaired myocardial glucose handling and distal distribution of coronary atherosclerosis. Trimetazidine, an anti-ischemic metabolic agent, improves myocardial glucose utilization though inhibition of fatty acid oxidation. Aim of the present study was to evaluate whether the metabolic effect of trimetazidine on left ventricular function in patients with diabetic cardiomyopathy.

Methods

32 patients (24 males and 8 females, mean (SE) age = 67 ± 6 years) with type 2 diabetes and ischemic cardiomyopathy were randomized to receive either trimetazidine (20 mg, t.d.s.) or placebo (t.d.s.) for six months in a randomized parallel study. Patients performed an echocardiogram at baseline and after 6 months.

Results

Demographic data were comparable between the two groups. After six month baseline left ventricular end-diastolic diameters increased from 62.4 ± 1.7 to 63 ± 2.1 mm in the placebo group, while decreased from 63.2 ± 2.1 to 58 ± 1.6 mm (p < 0.01 compared to baseline) in the trimetazidine group. Compared to baseline, left ventricular ejection fraction increased by 5.4 ± 0.5% (p < 0.05) in the trimetazidine group while remained unchanged in the placebo group -2.4 ± 1.1% (NS), p < 0.01 between groups. A significant improvement in wall motion score index and in the E/A wave ratio was detected in patients treated with trimetazidine, but not in those receiving placebo.

Conclusion

in diabetic patients with ischemic heart disease trimetazidine added to standard medical therapy has beneficial effect on left ventricular volumes and on left ventricular ejection fraction compared to placebo. This effect may be related to the effect of trimetazidine upon cardiac glucose utilization.     

Cell cycle -dependent proteolysis in plants. Identification Of the destruction box pathway and metaphase arrest produced by the proteasome inhibitor mg132

It is widely assumed that mitotic cyclins are rapidly degraded during anaphase, leading to the inactivation of the cell cycle-dependent protein kinase Cdc2 and allowing exit from mitosis. The proteolysis of mitotic cyclins is ubiquitin/26S proteasome mediated and requires the presence of the destruction box motif at the N terminus of the proteins. As a first attempt to study cyclin proteolysis during the plant cell cycle, we investigated the stability of fusion proteins in which the N-terminal domains of an A-type and a B-type tobacco mitotic cyclin were fused in frame with the chloramphenicol acetyltransferase (CAT ) reporter gene and constitutively expressed in transformed tobacco BY2 cells. For both cyclin types, the N-terminal domains led the chimeric cyclin-CAT fusion proteins to oscillate in a cell cycle-specific manner. Mutations within the destruction box abolished cell cycle-specific proteolysis. Although both fusion proteins were degraded after metaphase, cyclin A-CAT proteolysis was turned off during S phase, whereas that of cyclin B-CAT was turned off only during the late G2 phase. Thus, we demonstrated that mitotic cyclins in plants are subjected to post-translational control (e.g., proteolysis). Moreover, we showed that the proteasome inhibitor MG132 blocks BY2 cells during metaphase in a reversible way. During this mitotic arrest, both cyclin-CAT fusion proteins remained stable.     

Role of calcium in signal transduction during the hypersensitive response caused by basidiospore-derived infection of the cowpea rust fungus

The hypersensitive response (HR) of disease-resistant plant cells to fungal invasion is a rapid cell death that has some features in common with programmed cell death (apoptosis) in animals. We investigated the role of cytosolic free calcium ([Ca2+]i) in the HR of cowpea to the cowpea rust fungus. By using confocal laser scanning microscopy in conjunction with a calcium reporter dye, we found a slow, prolonged elevation of [Ca2+]i in epidermal cells of resistant but not susceptible plants as the fungus grew through the cell wall. [Ca2+]i levels declined to normal levels as the fungus entered and grew within the cell lumen. This elevation was related to the stage of fungal growth and not to the speed of initiation of subsequent cell death. Elevated [Ca2+]i levels also represent the first sign of the HR detectable in this cowpea-cowpea rust fungus system. The increase in [Ca2+]i was prevented by calcium channnel inhibitors. This effect was consistent with pharmacological tests in which these inhibitors delayed the HR. The data suggest that elevation of [Ca2+]i is involved in signal transduction leading to the HR during rust fungal infection.     

Minimal aerobic sludge retention time in biological phosphorus removal systems

The methodology for determination of the minimally required aerobic sludge retention time (SRTminaer) in biological phosphorus removal (BPR) systems is presented in this article. Contrary to normal biological conversions, the BPR process is not limited by a SRTmin resulting from the maximum growth rate of the organisms. This is because the aerobic SRT should be long enough to oxidize the amount of poly-hydroxy-alkanoates (PHA) stored in the anaerobic phase. This means that the SRTminaer will primarily depend on the PHA conversion kinetics and the maximal achievable PHA content in the cell (storage capacity). The model for the prediction of the minimally required aerobic SRT as a function of kinetic and process parameters was developed and compared with experimental data used to evaluate several operational aspects of BPR in a sequencing batch reactor (SBR) system. The model was proved as capable of describing them satisfactorily.Copyright 1998 John Wiley & Sons, Inc.     

Strike-induced chemosensory searching in old world vipers and new world pit vipers at San Diego Zoo

Rattlesnakes (Crotalus unicolor, C vegrandis) and Russell's vipers (Vipera russelli) at San Diego Zoo exhibited sustained high rates of tongue flicking after striking mice (Mus musculus) but not after seeing, smelling, and/or detecting thermal cues arising from mice. Called strike-induced chemosensory searching (SICS), this phenomenon contributes to poststrike trailing of envenomated prey. Because these zoo-raised snakes had always been offered dead rodents, and because these prey were usually ingested without first being struck, the present snakes had rarely exercised their innate predatory repertoire (ie, ambush tactics including striking, releasing, and trailing). Indeed, most specimens had never before struck a mouse and, hence, had never exhibited SICS. The occurrence of SICS in the present study clearly indicates that this important aspect of the predatory repertoire had not been degraded as a consequence of long-term captive husbandry.