Two dimensional-QSAR and molecular dynamics studies of a selected class of aldoxime- and hydroxy-functionalized chalcones as monoamine oxidase-B inhibitors

Candidates generated from unsaturated ketone (chalcone) demonstrated as strong, reversible and specific monoamine oxidase-B (MAO-B) inhibitory activity. For the research on MAO-B inhibition, our team has synthesized and evaluated a panel of aldoxime-chalcone ethers (ACE) and hydroxylchalcones (HC). The MAO-B inhibitory activity of several candidates is in the micro- to nanomolar range in these series. The purpose of this research was to develop predictive QSAR models and look into the relation between MAO-B inhibition by aldoxime and hydroxyl-functionalized chalcones. It was shown that the molecular descriptors ETA Shape P, MDEO-12, ETA dBetaP, SpMax1 Bhi and ETA EtaP B are significant in the inhibitory action of the MAO-B target. Using the current 2D QSAR models, potential chalcone-based MAO-B inhibitors might be created. The lead molecules were further analyzed by the detailed molecular dynamics study to establish the stability of the ligand-enzyme complex.Communicated by Ramaswamy H. Sarma.

1354 USING REALIST PROGRAMME THEORY TO DESIGN A NEW INTERVENTION FOR IMPROVING RECOVERY AFTER DELIRIUM

Introduction

People who recover poorly after delirium are likely to require an increased level of care. It is presently unknown whether interventions to improve recovery after delirium are effective and cost-effective. This research aimed to develop a programme theory to inform the design of an intervention to improve recovery after delirium.

Method

A rapid realist review of literature was conducted to develop an initial programme theory. Following this, a qualitative investigation of the perceived rehabilitation needs of older people who have experienced delirium during a hospital stay was conducted via semi-structured interviews with 41 key stakeholders (older people (5), carers (12), and healthcare professionals (24)). Data were analysed using a realist approach to identify what works, for whom, and in what context. This was deductively informed by the initial programme theory while also employing an inductive analysis to identify novel insights. Through an iterative, retroductive process, context-mechanism-outcome configurations (CMOCs) were coded to reflect stakeholders’ views to refine the programme theory.

Results

The initial programme theory highlighted the importance of cognitive and physical rehabilitation and emotional support as key domains of recovery. New CMOCs included optimisation of good medical care to manage delirium and monitoring and management of underlying medical conditions to promote recovery. Others included developing educational resources and support networks for older people and their carers to aid sense-making, and encouraging social interaction to reduce isolation and empower independent functioning. These recovery elements should be addressed in a person-centred manner that is tailored to individual needs and preferences, engages carers, integrates intervention goals into daily functioning, and ensures continuity of care.

Conclusion

A refined programme theory was developed and is currently being used to design a manualised intervention to improve recovery after delirium. The acceptability of the intervention will be tested in a multi-centre, single-arm feasibility study.

Processing of Aluminium-Silicon Alloy with Metal Carbide as Reinforcement through Powder-Based Additive Manufacturing: A Critical Study

Powder-based additive manufacturing (PAM) is a potential fabrication approach in advancing state-of-the-art research to produce intricate components with high precision and accuracy in near-net form. In PAM, the raw materials are used in powder form, deposited on the surface layer by layer, and fused to produce the final product. PAM composite fabrication for biomedical implants, aircraft structure panels, and automotive brake rotary components is gaining popularity. In PAM composite fabrication, the aluminium cast alloy is widely preferred as a metal matrix for its unique properties, and different reinforcements are employed in the form of oxides, carbides, and nitrides. However, for enhancing the mechanical properties, the carbide form is predominantly considered. This comprehensive study focuses on contemporary research and reveals the effect of metal carbide's (MCs) addition to the aluminium matrix processed through various PAM processes, challenges involved, and potential scopes to advance the research.

Genotypes of hepatitis C virus in the Indian sub-continent: a decade-long experience from a tertiary care hospital in South India

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of chronic liver disease (CLD) that can progress to cirrhosis and hepatocellular carcinoma. Genotypes of HCV can vary in pathogenicity and can impact on treatment outcome.

OBJECTIVES

To study the different genotypes among patients with HCV related CLD attending a tertiary care hospital in south India during 2002-2012.

STUDY DESIGN

Study subjects were those referred to clinical virology from the liver clinic. Genotyping was performed using the genotype specific core primers in nested polymerase chain reaction (PCR), 5' non-coding regions based PCR- restriction fragment length polymorphism and NS5B sequencing methods. With the latter method, obtained sequences were compared with published GenBank sequences to determine the genotype.

RESULTS

Of the 451 samples tested, HCV genotype 3 was found to be the most predominant (63.85%). Other genotypes detected were genotype 1 (25.72%), genotype 2 (0.002%), genotype 4 (7.5%) and genotype 6 (2.7%). Genotype 3 was the common genotype in patients from Eastern India while genotype 1 and 4 were mainly seen in South Indian patients. Genotype 6 was seen exclusively in patients from North-Eastern India. Two other patients were infected with recombinants of genotype 1 and 2.

CONCLUSIONS

In this study spanning a decade, HCV genotype 3 and genotype 1 were found to be the predominant genotypes in the Indian sub-continent. Genotype 4 and genotype 6 appeared to show some geographic restriction. A continued monitoring of HCV genotypes is essential for the optimum management of these chronically infected patients. In addition, knowledge of circulating genotypes could impact on future vaccine formulations.

Rapid diagnosis of Mycobacterium tuberculosis meningitis by enumeration of cerebrospinal fluid antigen-specific T-cells

SETTING

Hospital in-patients with suspected tuberculous meningitis (TBM), predominantly in India.

OBJECTIVE

To determine whether interferon-gamma (IFN-gamma) secreting Mycobacterium tuberculosis antigen-specific T-cells are present in the cerebrospinal fluid (CSF) of patients with TBM and to evaluate the feasibility of CSF enzyme-linked immunospot (ELISpot) for the diagnosis of active TBM.

DESIGN

Prospective blinded hospital-based study.

RESULTS

The overnight ELISpot assay detected M. tuberculosis antigen-specific IFN-gamma secreting T-cells in CSF from nine of 10 prospectively recruited patients with TBM, and zero of seven control patients with meningitis of other aetiology. This corresponds to a diagnostic sensitivity of 90% (95%CI 56-100) and specificity of 100% (95%CI 59-100).

CONCLUSION

This pilot study demonstrates proof-of-principle for a new T-cell-based diagnostic test for TBM which is rapid, sensitive and specific.

Significance of the hepatitis C virus (HCV) core antigen as an alternative plasma marker of active HCV infection

PURPOSE

To evaluate the role of core antigen (Ortho trak-C assay) as a marker of active HCV infection in comparison to HCV RNA as detected by reverse transcription polymerase chain reaction (RT-PCR).

METHODS

This evaluation was carried out during January 2000 to December 2003 in HCV infected individuals who were treatment naomicronve or were on anti-viral therapy. Additionally, sequential plasma samples from patients on clinical follow-up were included in this study. A total of 167 samples from 61 patients were tested by trak-C and RT-PCR. HCV RNA detection was achieved by a RT-PCR. Trak-C assay results were also compared in a limited proportion of these samples with known HCV viral load and genotype.

RESULTS

Of 167 samples tested, 56.9% were RNA positive and 43.1% were RNA negative while 50.3% were trak-C positive and 49.7% were trak-C negative, yielding a sensitivity of 85.3% and a specificity of 95.8% for the trak-C assay (Kappa co-efficient = 0.8). The concentration of HCVcAg and HCV RNA showed significant correlation (n=38, r=0.334, P =0.04). The trak-C assay detected the most prevalent HCV genotypes in India without significant difference (P =0.335). The difference between mean absorbance values of HCV RNA positive samples compared to HCV RNA negative samples in the trak-C assay was highly significant (P < 0.000). Qualitative results of trak-C assay and RT-PCR were comparable in 93% of follow-up samples.

CONCLUSIONS

Trak-C assay can be recommended for confirmation of HCV infection and follow-up in laboratories with resource-poor facilities.

Evaluation of an indigenously manufactured rapid immunochromatographic test for detection of HBsAg

A 'rapid' one step immunochromatographic, visually read, antigen capture assay--the "HEPACARD" (J Mitra & Co. Ltd., New Delhi, India) used for rapid screening of HBsAg was evaluated. Thousand consecutive sera sent to our laboratory for the purpose of HBsAg screening were tested by this device and by a third generation enzyme immunoassay (EIA) (Auszyme Monoclonal, Abbott Laboratories, Chicago, Illinois) or an automated Axsym microparticle enzyme immunoassay (MEIA) (Axsym HBsAg V2, Abbott Laboratories, Abbott Park, Chicago, Illinois, ISA). Hepacard showed a sensitivity of 79% (CU: 57.3-92%) and specificity of 98.9% (CI: 97.9-99.4%) when compared to the findings by the third generation EIA assays. This study suggested that this particular rapid HBsAg test results have to be confirmed by either an EIA or MEIA where the facility exists. The test may be used only in a small hospital setting where the facilities for enzyme immuno assays do not exist.

Infrequent occurrence of silent HBV infection among Indian patients with chronic liver disease

OBJECTIVE

To investigate the occurrence of silent hepatitis B virus (HBV) infection among patients with chronic liver disease (CLD).

METHODS

Plasma samples from 71 CLD patients including 9 HBsAg-positive individuals were tested for HBV DNA by nested polymerase chain reaction (nPCR), and for HBV serum markers, i.e., anti-HBc antibody, HBeAg and anti-HBe antibody. The individuals were also tested for hepatitis C virus (HCV) RNA and anti-HCV antibody.

RESULTS

Among 62 HBsAg-negative patients, silent HBV infection was seen in only two (3.2%). Silent HBV infection was not found in any of the 26 patients who had evidence of HCV infection. One HBsAg-positive patient was positive for anti-HCV in the absence of HCV RNA.

CONCLUSIONS

There is a low rate of silent HBV infection among patients with CLD in India, where HBV is moderately endemic. Silent HBV infection is not associated with HCV-related CLD, which is in contrast to reports from other HBV-endemic areas in Asia.

Prevalence of enterically transmitted hepatitis viruses in patients attending a tertiary--care hospital in south India

The prevalance of enterically transmitted hepatitis viruses, namely, hepatitis A virus (HAV) and hepatitis E virus (HEV) were studied in 404 patients with acute hepatitis attending a tertiary-care hospital in south India. Presence of current HAV/HEV infection was ascertained by the demonstration of IgM antibodies. In 381 patients tested for both agents, HAV IgM was present in 51(13.3%) and HEV IgM present in 66(17.3%). There was dual infection in 3 males (0.8%). HEV infection was seen mostly in older children and adults with only 5.5% occurring in children < 12 years of age. HAV infection was commonly seen to occur in < 12 years of age group (52.7%). One hundred and twenty-six patients were from the Vellore region, among whom HAV and/or HEV aetiology was observed in 28.5%. In this region there did not appear to be any correlation between occurrence of acute hepatitis due to these viruses and rainfall or environmental temperature. Acute hepatitis due to enteric hepatitis viruses was seen throughout the year.

Role of molecular techniques in the detection of HBV DNA & HCV RNA among renal transplant recipients in India

In this study we have investigated the occurrence of hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV) infections among 68 renal transplant recipients. Replicative HBV and replicative HCV infections were seen in 12 (17.6%) and 38 (55.9%) patients respectively, the difference was statistically significant (P < 0.001). Among the 38 HCV RNA+ individuals, anti-HCV was present only in 23. Anti-HCV in the absence of HCV RNA was detected in one patient. Anti-HDV antibody was seen in 2 (15.4%) of the 13 HBV infected individuals. Nine (13.2%) of the 68 individuals had replicative dual infection with HBV and HCV. Triple infection (HBV DNA+, HCV RNA+, anti-HDV+) was seen in 2 transplant recipients. There was significantly higher demonstration of replicative HCV (P < 0.001) in transplant recipients having elevated liver enzymes (n = 34) as compared to transplant recipients having normal liver enzyme levels (n = 34). Though not significant, a higher detection rate was also seen with replicative HBV infection and replicative dual infection among transplant recipients with elevated liver enzymes. The higher detection of HCV in renal transplant recipients by molecular techniques, emphasizes the need for HCV RNA testing. Further deliberate attempts to change practices to reduce this problem may also improve graft and patient survival in recipients.

Comparison of two different methodologies for the detection of hepatitis B virus DNA in plasma

In this study, two different methodologies were compared for the detection of hepatitis B virus (HBV) DNA in the plasma of 28 patients and 36 controls. Method 1 was a nested polymerase chain reaction (PCR) followed by product detection in an ethidium bromide stained gel, whereas method II was a commercial single step PCR with digoxigenin labeled product captured by a probe and then detected in a digoxigenin-antidigoxigenin enzyme-linked immunosorbent assay (DIG ELISA). The results indicate that both methods are comparable showing a concordance of 98.4%, there was no statistically significant difference in the detection rates. We feel that any one of these assays may be suitable in a clinical laboratory setting, though the commercial assay may offer some advantages to laboratories without sufficient skilled staff in trouble-shooting PCR related problems.