Binding mode of conformations and structure-based pharmacophore development for farnesyltransferase inhibitors

Farnesyltransferase (FTase) is one of the prenyltransferase family enzymes that catalyse the transfer of 15-membered isoprenoid (farnesyl) moiety to the cysteine of CAAX motif-containing proteins including Rho and Ras family of G proteins. Inhibitors of FTase act as drugs for cancer, malaria, progeria and other diseases. In the present investigation, we have developed two structure-based pharmacophore models from protein–ligand complex (3E33 and 3E37) obtained from the protein data bank. Molecular dynamics (MD) simulations were performed on the complexes, and different conformers of the same complex were generated. These conformers were undergone protein–ligand interaction fingerprint (PLIF) analysis, and the fingerprint bits have been used for structure-based pharmacophore model development. The PLIF results showed that Lys164, Tyr166, TrpB106 and TyrB361 are the major interacting residues in both the complexes. The RMSD and RMSF analyses on the MD-simulated systems showed that the absence of FPP in the complex 3E37 has significant effect in the conformational changes of the ligands. During this conformational change, some interactions between the protein and the ligands are lost, but regained after some simulations (after 2 ns). The structure-based pharmacophore models showed that the hydrophobic and acceptor contours are predominantly present in the models. The pharmacophore models were validated using reference compounds, which significantly identified as HITs with smaller RMSD values. The developed structure-based pharmacophore models are significant, and the methodology used in this study is novel from the existing methods (the original X-ray crystallographic coordination of the ligands is used for the model building). In our study, along with the original coordination of the ligand, different conformers of the same complex (protein–ligand) are used. It concluded that the developed methodology is significant for the virtual screening of novel molecules on different targets.     

Exophytic gliomas of the spinal cord

Intradural extramedullary glial tumours of the spinal cord are rare. We report for such tumours arising from the dorsal cord. Myelography and operative findings were almost similar to that of an intradural neurofibroma. Surgical removal had resulted in rewarding neurological recovery. One of them had a recurrence after six years and was re-explored. Anterolateral attachment near the root entry zone suggests its origin probably from the spinal cord with an exophytic growth.     

1.5 tesla magnetic resonance imaging of acute spinal trauma

Fifty patients with spinal injury above L2 were studied with MRI; forty-two had initial and followup studies permitting correlation of MRI abnormalities with neurologic improvement. Two discrete patterns of MRI abnormality were identified, presumably representing cord hemorrhage and edema respectively. A third pattern appeared to represent a mixed type of injury. The correlation between the MRI patterns of cord injury and neurologic recovery was excellent. The ability of MRI to demonstrate and characterize acute cord injury appears to exceed that of other diagnostic techniques.     

Aid for impacted foreign body ear

Foreign body ear is a common problem. When it is impacted it can tax the resorces of each of us. An attempt is made in this paper to make a customable foreign body removal hook using a lumbar puncture needle.     

Regulation of rapid eye movement sleep in the freely moving rat: local microinjection of serotonin,norepinephrine, and adenosine into the brainstem

STUDY OBJECTIVES: Considerable evidence suggests that rapid eye movement (REM) sleep is induced by glutamatergic activation of cholinergic cells within the pedunculopontine tegmentum (PPT). The aim of this study is to test a popular hypothesis that serotonin, norepinephrine, and adenosine act on PPT cells to regulate REM sleep. This study also tests an alternate hypothesis that serotonin may inhibit REM sleep signs by direct action on the individual REM sleep sign generators. DESIGN: Serotonin, norepinephrine, and adenosine were locally microinjected into the PPT and serotonin was microinjected into the pontine-wave (P-wave) generator (dorsal part of the locus subcoeruleus nucleus) while quantifying the effects on REM sleep and P-wave activity in freely moving rats. SETTING: N/A. PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Local microinjections of serotonin, norepinephrine, and adenosine into the PPT did not change REM sleep. Microinjection of serotonin into the P-wave generator suppressed P-wave activity but not REM sleep. CONCLUSIONS: The present findings provide direct evidence that serotonin, norepinephrine, and adenosine-induced REM sleep suppression in the behaving rat are not mediated by the PPT. The results also provide direct evidence, for the first time, that serotonin suppresses P-wave activity by acting directly on the P-wave generator. These results suggest that the serotonin-induced inhibition of REM sleep in the freely moving rat is probably not mediated through the mesopontine cholinergic cell compartment but, rather, through individual REM sleep sign generators.     

Aneurysm detection using one-bit correlation

Intercranial aneurysm present an especially serious clinical problem, since their rupture generally results in death or permanent brain damage. Recent work, conducted by the authors, indicated that this anomaly can be detected using spectral signature analysis. A low-cost turnkey noninvasive aneurysm-detection system is being tested for this purpose. Using polarity-coincident noise-added one-bit correlators, aneurysms have been successfully detected.