Virtual Screening of compounds to 1-deoxy-Dxylulose 5-phosphate reductoisomerase (DXR) from Plasmodium falciparum.

The 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) protein (Gen Bank ID AAN37254.1) from Plasmodium falciparum is a potential drug target. Therefore, it is of interest to screen DXR against a virtual library of compounds (at the ZINC database) for potential binders as possible inhibitors. This exercise helped to choose 10 top ranking molecules with ZINC00200163 [N-(2,2di methoxy ethyl)-6-methyl-2, 3, 4, 9-tetrahydro-1H-carbazol-1-amine] a having good fit (-6.43 KJ/mol binding energy) with the target protein. Thus, ZINC00200163 is identified as a potential molecule for further comprehensive characterization and in-depth analysis.

In-silico screening and in-vitro validation of Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) inhibitors.

VEGFR-2 tyrosine kinase receptor draws attention of the scientific fraternity in drug discovery for its important role in cancer, cardiopulmonary, cardiovascular diseases etc. Hence there is a need for novel VEGFR-2 inhibitors screening and testing for their biological activities. The 3D-structure was collected from PDB and stability was checked by using WHATIF and PROCHECK programs and subjected for virtual screening on Zinc database. We used virtual screening method to screen new VEGFR-2 blocker molecules based on their binding energies and then docked with active site on the receptor with the help of AUTODOCK software. Based on the results obtained top three molecules (VRB1-3) were selected and tested in Cardiomyocytes H9c2 cells for cell viability under hypoxic condition. The invitro studies showed VRB2 as the best molecule among the selected three molecules as well as with a standard commercial drug Sunitinib.

Molecular dynamic and docking interaction study of Heterodera glycines serine proteinase with Vigna mungo proteinase inhibitor.

Many plants do produce various defense proteins like proteinase inhibitors (PIs) to protect them against various pests. PIs function as pseudosubstrates of digestive proteinase, which inhibits proteolysis in pests and leads to amino acid deficiency-based mortality. This work reports the structural interaction studies of serine proteinase of Heterodera glycines (SPHG) with Vigna mungo proteinase inhibitor (VMPI). 3D protein structure modeling, validation of SPHG and VMPI, and their putative protein-protein binding sites were predicted. Protein-protein docking followed by molecular dynamic simulation was performed to find the reliable confirmation of SPHG-VMPI complex. Trajectory analysis of each successive conformation concludes better interaction of first loop in comparison with second loop. Lysine residues of first loop were actively participating in complex formation. Overall, this study discloses the structural aspects and interaction mechanisms of VMPI with SPHG, and it would be helpful in the development of pest-resistant genetically modified crops.

Results of a national mass media campaign in India to warn against the dangers of smokeless tobacco consumption.

OBJECTIVE: Smokeless tobacco consumption in India is a significant source of morbidity and mortality. In order to educate smokeless tobacco users about the health harms of smokeless tobacco and to denormalise tobacco usage and encourage quitting, a national television and radio mass media campaign targeted at smokeless tobacco users was aired for 6 weeks during November and December 2009. METHODS: The campaign was evaluated with a nationally representative household survey of smokeless tobacco users (n = 2898). The effect of campaign awareness was assessed with logistic regression analysis. RESULTS: The campaign affected smokeless tobacco users as intended: 63% of smokeless-only users and 72% of dual users (ie, those who consumed both smoking and smokeless forms) recalled the campaign advertisement, primarily through television delivery. The vast majority (over 70%) of those aware of the campaign said that it made them stop and think, was relevant to their lives and provided new information. 75% of smokeless-only users and 77% of dual users said that it made them feel concerned about their habit. Campaign awareness was associated with better knowledge, more negative attitudes towards smokeless tobacco and greater cessation-oriented intentions and behaviours among smokeless tobacco users. CONCLUSIONS: Social marketing campaigns that utilise mass media are feasible and efficacious interventions for tobacco control in India. Implications for future mass media tobacco control programming in India are discussed.

Ligand based virtual screening to find novel inhibitors against plant toxin Ricin by using the ZINC database.

Ricin is known as a potent toxin against animals. It consists of two chains, Ricin Toxin A (RTA) and Ricin Toxin B (RTB). The toxic effect is known to be caused by RTA. Inhibitors for RTA with less efficiency have been reported. Hence, it is of interest to identify new inhibitors. Virtual screening methods (computer aided drug designing) to find similar molecules in drug database were used for screening new inhibitors against RTA. We used the structure of RTA in complex with Pteroic acid (PDB code: 1BR6) as target molecule. Ligand based virtual screening approach was used in which the known inhibitory molecule Pteroic acid (PTA) served as a template to identify similar ligands from the ZINC database. These ligands were docked inside the binding pocket of RTA by using the MVD (Molegro Virtual Docker). This approach successfully identified six novel compounds. These docked ligands interacted with Asn78, Ala79, Val81, Gly121 and Ser176 amino acids, which are key residues of the RTA active site. Three compounds in particular, ZINC05156321 (6, 7 diphenylpteridin-4-ol), ZINC05156324 (6, 7-bis (3-fluorophenyl) pteridin-4-ol) and ZINC08555900 (6, 7-bis (4-fluorophenyl)-1H-pteridin-4-one), showed higher binding affinity in comparison to PTA, with high interaction energy, better space fitting and electrostatic interactions. These molecules should be tested for in vitro and in vivo activities in future for consideration as effective inhibitors.

Visfatin--a review.

Expedited research on Obesity has confirmed that, adipose tissue is highly active in secreting a variety of proteins, one among them is visfatin. It was originally identified as Pre B cell Colony Enhancing Factor (PBEF), to be secreted by the lymphocytes and can act as a cytokine with immune regulatory action. Besides, it acts as Nicotinamide phosphoribosyl transferase (Nampt), an enzyme involved in the NAD+ salvage pathway. It has been shown to help in the regulation of glucose homeostasis, but whether it binds to insulin receptor and exerts insulin mimetic activity is still a controversy. Visfatin has antiapoptotic activity and has a regulatory role in inflammation. Several studies have identified changes in the circulatory levels of visfatin in diseases. Notable among them are obesity, diabetes mellitus, kidney diseases and bone disorders. It is a molecule of clinical relevance and could be a promising biomarker with diagnostic and prognostic significance.

Thigh infection and subcutaneous emphysema: an emergency, review of literature and case discussion.

Thigh infection associated with local emphysematous signs on presentation to the emergency room should alert the medical staff at once of potential complication associated with it. The infection may be associated with underlying bowel pathology and has a high mortality rate. Hence, emergency treatment should be instituted. We discuss a case with this uncommon presentation, treatment administered and relevant literature.

Erythrocyte glutathione peroxidase, glutathione reductase activities and blood glutathione content in leprosy.

OBJECTIVES: Leprosy is a chronic granulomatous infection caused by Mycobacterium leprae involving cutaneous tissue and peripheral nerves producing skin lesions, nerve degeneration, anaesthesia and deformities. In leprosy, the activated phagocytes produce reactive oxygen species (ROS) as a part of their microbicidal function. Such ROS are capable of damaging the host tissue by lipid peroxidation. Increased lipid peroxidation has been reported in leprosy. The glutathione antioxidant system with glutathione peroxidase (GSH-Px), glutathione reductase (GR) and glutathione (GSH) as components protect the cells from ROS toxicity and lipid peroxidation. The objective of the present study was to assess blood glutathione content and erythrocyte antioxidant enzyme activities of glutathione peroxidase and glutathione reductase in leprosy. DESIGN: The parameters were studied in 100 leprosy patients and 50 normal healthy controls. The data was analysed by grouping the patients into Ridley-Jopling (RJ) types [tuberculoid leprosy (TT), borderline tuberculoid leprosy (BT), borderline leprosy (BB), borderline lepromatous leprosy (BL), lepromatous leprosy (LL)] and into different levels of Bacteriological Index (BI) [bacteriologically negative (BI=0), BI=0.1-1, BI=1.1-2, BI=2.1-3, BI=3.1-4, BI=4.1-6]. METHODS: Venous blood sample was used for the study. The GSH level was estimated in the blood by DTNB [5,5'-dithiobis(2-nitrobenzoic acid)] reduction method. The enzyme activities were measured in the red blood cell haemolysate by kinetic methods using NADPH. RESULTS: GSH, GSH-Px and GR were significantly low in leprosy (total patients) as compared to the control group (p<0.001). A progressive decrease in GSH level and enzyme activities was noted along the leprosy spectrum from TT to LL. A significant decline of GSH in BB (p<0.05), BL (p<0.005) and LL (p<0.001); and of GSH-Px and GR in BT (p<0.05, p<0.02), BB (p<0.02), BL (p<0.005) and LL (p<0.001) was noted as compared to controls. A significant lowering of GSH-Px in LL (p<0.005); the GR in BB (p<0.02), BL (p<0.05) and LL (p<0.05); and the GSH in BL (p<0.01) and LL (p<0.001) was noted in comparison to the TT group. The GSH and GSH-Px were significantly low in LL (p<0.05) as compared to BT. A progressive decreasing trend in GSH level and enzyme activities was also noticed along the leprosy groups with advancing level of BI. The GSH, GSH-Px and GR were significantly low in BI levels 1.1-2 (p<0.005, p<0.05, p<0.02), 2.1-3 (p<0.005, p<0.001, p<0.005), 3.1-4 (p<0.005) and 4.1-6 (p<0.01, p<0.005, p<0.05) as compared to controls. A significant decline in GSH was noted in BI levels 1.1-2 (p<0.005), 2.1-3 (p<0.005), 3.1-4 (p<0.005) and 4.1-6 (p<0.01) as compared to the bacteriologically negative group. The GSH-Px (p<0.05) and GR (p<0.05) were significantly low in BI levels 2.1-3, 3.1-4 and 4.1-6 as compared to the bacteriologically negative group. CONCLUSION: The findings suggest oxidative stress associated with diminished antioxidant defence potential in leprosy. The study identifies association of diminished antioxidant potential with bacterial load and type of leprosy.

Signal peptide peptidase and gamma-secretase share equivalent inhibitor binding pharmacology.

The enzyme gamma-secretase has long been considered a potential pharmaceutical target for Alzheimer disease. Presenilin (the catalytic subunit of gamma-secretase) and signal peptide peptidase (SPP) are related transmembrane aspartyl proteases that cleave transmembrane substrates. SPP and gamma-secretase are pharmacologically similar in that they are targeted by many of the same small molecules, including transition state analogs, non-transition state inhibitors, and amyloid beta-peptide modulators. One difference between presenilin and SPP is that the proteolytic activity of presenilin functions only within a multisubunit complex, whereas SPP requires no additional protein cofactors for activity. In this study, gamma-secretase inhibitor radioligands were used to evaluate SPP and gamma-secretase inhibitor binding pharmacology. We found that the SPP enzyme exhibited distinct binding sites for transition state analogs, non-transition state inhibitors, and the nonsteroidal anti-inflammatory drug sulindac sulfide, analogous to those reported previously for gamma-secretase. In the course of this study, cultured cells were found to contain an abundance of SPP binding activity, most likely contributed by several of the SPP family proteins. The number of SPP binding sites was in excess of gamma-secretase binding sites, making it essential to use selective radioligands for evaluation of gamma-secretase binding under these conditions. This study provides further support for the idea that SPP is a useful model of inhibitory mechanisms and structure in the SPP/presenilin protein family.

Ex vivo occupancy of gamma-secretase inhibitors correlates with brain beta-amyloid peptide reduction in Tg2576 mice.

Reduction of brain beta-amyloid peptide (Abeta) synthesis by gamma-secretase inhibitors is a promising approach for the treatment of Alzheimer's disease. However, measurement of central pharmacodynamic effects in the Alzheimer's disease patient will be a challenge. Determination of drug occupancy may facilitate the analysis of efficacy of gamma-secretase inhibitors in a clinical setting. In this study, the relationship of gamma-secretase site occupancy and brain Abeta40 reduction by gamma-secretase inhibitors was examined in Tg2576 mice. [3H](2R,3S)-2-Isobutyl-N1-((S)-1-methyl-2-oxo-5-phenyl-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)-3-propylsuccinamide (IN973) was used as a gamma-secretase radioligand, since it has been shown to bind to gamma-secretase in rat, rhesus, and human brains with high affinity and specificity. We extended these findings by showing that [3H]IN973 bound to gamma-secretase in Tg2576 brains with an affinity, specificity, and regional localization very similar to the other species. To quantify gamma-secretase occupancy by gamma-secretase inhibitors, an ex vivo binding assay was developed using [3H]IN973 and frozen brain sections from drug-treated mice. Gamma-secretase occupancy and brain Abeta40 reduction were found to be highly correlated in animals dosed with either 2-[(1R)-1-[[4-chlorophenyl)-sulfonyl](2,5-difluorophenyl)amino] ethyl]-5-fluoro-benzenepropanoic acid (BMS-299897) or (S)-2-((S)-2-(3,5-difluorophenyl)-2-hydroxyacetamido)-N-((S,Z)-3-methyl-4-oxo-4,5-dihydro-3H-benzo[d][1,2]diazepin-5-yl)propanamide (BMS-433796) over a wide range of doses and times postdose, with the exception of the earliest times postdose. This lag in Abeta40 response to gamma-secretase inhibition is probably related to the delayed clearance of previously produced Abeta40. The excellent correlation between brain Abeta40 and gamma-secretase occupancy suggests that a positron emission tomography ligand for gamma-secretase could be a valuable biomarker to determine whether gamma-secretase inhibitors bind to their target in humans.

N-(5-chloro-2-(hydroxymethyl)-N-alkyl-arylsulfonamides as gamma-secretase inhibitors.

A series of N-alkylbenzenesulfonamides were developed from a high throughput screening hit. Classic and parallel synthesis strategies were employed to produce compounds with good in vitro and in vivo gamma-secretase activity.

Discovery of (S)-2-((S)-2-(3,5-difluorophenyl)-2-hydroxyacetamido)-N-((S,Z)-3-methyl-4-oxo-4,5-dihydro-3H-benzo[d][1,2]diazepin-5-yl)propanamide (BMS-433796): a gamma-secretase inhibitor with Abeta lowering activity in a transgenic mouse model of Alzheimer's disease.

We report on the design of benzodiazepinones as peptidomimetics at the carboxy terminus of hydroxyamides. Structure-activity relationships of diazepinones were investigated and orally active gamma-secretase inhibitors were synthesized. Active metabolites contributing to Abeta reduction were identified by analysis of plasma samples from Tg2576 mice. In particular, (S)-2-((S)-2-(3,5-difluorophenyl)-2-hydroxyacetamido)-N-((S,Z)-3-methyl-4-oxo-4,5-dihydro-3H-benzo[d][1,2]diazepin-5-yl)propanamide (BMS-433796) was identified with an acceptable pharmacodynamic and pharmacokinetic profile. Chronic dosing of BMS-433796 in Tg2576 mice suggested a narrow therapeutic window and Notch-mediated toxicity at higher doses.

Erythrocyte superoxide dismutase, catalase activities and hydrogen peroxide induced lipid peroxidation in leprosy.

OBJECTIVES: To assess erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities and hydrogen peroxide induced lipid peroxidation in leprosy. DESIGN: One hundred leprosy patients and 50 normal healthy controls were studied for the parameters. The data was analysed by grouping the patients into Ridley-Jopling (RJ) types [Tuberculoid leprosy (TT, n = 22), Borderline tuberculoid leprosy (BT, n = 28), Borderline leprosy (BB, n = 13), Borderline lepromatous leprosy (BL, n = 16) and Lepromatous leprosy (LL, n = 21)] and into different levels of Bacteriological Index (BI) [bacteriologically negative (n = 32), BI = 0.1-1 (n = 22), BI = 1.1-2 (n = 16), BI = 2.1-3 (n = 14), BI = 3.1-4 (n = 10) and BI = 4.1-6 (n = 06)]. RESULTS: The induced peroxidation was significantly high and the enzyme activities were significantly low in leprosy (total patients) as compared to controls. A progressive increase in peroxidation was detected along the leprosy spectrum from TT to LL and the increase was significant in BB, BL and LL groups as compared to controls. Induced peroxidation in LL group as compared to TT, BT and BB and in the BL group as compared to TT and BT were significantly different. A concomitant progressive decline in enzyme activity was detected along the leprosy spectrum from TT to LL. The SOD activity in BB, BL and LL and the CAT activity in BL and LL were significantly low as compared to controls. SOD activity in BB, BL and LL groups as compared to TT and in the LL group as compared to BT were significantly different. A progressive trend of increasing peroxidation and decreasing SOD and CAT activity were also detected along the leprosy groups with advancing level of BI. Induced peroxidation and SOD activity were significantly different in bacteriologically positive groups as compared to controls and in the BI levels 1.1-2, 2.1-3, 3.1-4 and 4.1-6 as compared to bacteriologically negative group. The peroxidation was significantly different in BI levels 2.1-3, 3.1-4 and 4.1-6 as compared to BI level 0.1-1. The CAT activity was significantly different in BI levels 2.1-3, 3.1-4 and 4.1-6 as compared to controls. CONCLUSION: The study findings suggest oxidative stressful state associated with reduced antioxidant defence potential in erythrocytes of leprosy patients. The study implicates association of erythrocyte oxidative stress with bacterial load and type of leprosy.

The effect of traction on compartment pressures during intramedullary nailing of tibial-shaft fractures. A prospective randomised trial.

Our aim was to study the effect of traction on the compartment pressures during intramedullary nailing of closed tibial-shaft fractures. Thirty consecutive patients with Tscherne C1 fractures were randomised into two groups. Sixteen patients underwent intramedullary nailing of the tibia with traction and 14 patients without traction. Compartment pressures were measured before the application of traction or commencement of the procedure and at the end of the procedure. The data collected was analysed using Student's t test. There was no statistically significant difference (p>0.05) in the pre-operative mean compartment pressures for both groups. The mean post-operative measurements were higher in all four compartments in the traction group (p<0.05). None of the pressures reached the critical level. These results show that traction as an aid unnecessarily increases compartment pressures.

2,3-Benzodiazepin-1,4-diones as peptidomimetic inhibitors of gamma-secretase.

2,3-Benzodiazepin-1,4-diones were designed as peptidomimetics at the carboxy terminus of hydroxyamides. Inhibition of brain Abeta production was improved by one of the compounds containing constrained modification.

Abdominal muscle action during expiration can impair pressure controlled ventilation.

Pressure controlled ventilation, and pressure support for spontaneous breathing are often used in intensive care because coordination of the ventilator with patient efforts can improve comfort and possibly reduce sedation. However we report a series of 10 patients whose efforts did not synchronise with pressure controlled ventilation. This was incorrectly diagnosed as inadequate sedation, and treated with increased sedation or muscle paralysis. Better recognition of this condition showed that slow respiratory rates and increased abdominal muscle action during expiration can affect pressure-controlled ventilation and pressure assisted breathing. If the condition is not recognised, treatment for poor synchronisation may delay weaning or be inappropriate.

Hydroxytriamides as potent gamma-secretase inhibitors.

Using a cell-based assay, we have identified optimal residues and key recognition elements necessary for inhibition of gamma-secretase. An (S)-hydroxy group or 3,5-difluorophenylacetyl group at the amino terminus and N-methyltertiary amide moiety at the carboxy terminus provided potent gamma-secretase inhibitors with an IC(50) <10 nM.

Isolated dislocation of the proximal tibiofibular joint in a long jumper.

Acute traumatic proximal tibiofibular joint dislocation is an exceedingly rare injury. This is a case report in a rare horizontal type joint variant, following a long jump injury. The diagnostic approach when this injury is suspected is described.

Outcome of compartment syndrome following intramedullary nailing of tibial diaphyseal fractures.

Seventeen cases of compartment syndrome were treated in a group of 626 consecutive patients with tibial diaphyseal fractures. Clinical and radiological follow-up was performed at an average of 24 months (range 8-54 months). Functional outcome was assessed using Edward's classification. All patients who developed compartment syndrome had fracture stabilisation with a reamed intramedullary nail using skeletal traction. The average interval between the nailing procedure and fasciotomy was 11 h. Results were good in 10 cases, fair in four cases and poor in the remaining three cases. Patients who had decompression within 12 h had a good functional outcome. Patients with poor results were all treated at an interval greater than 24 h.