In silico guided designing of 4-(1H-benzo[d]imidazol-2-yl)phenol-based mutual-prodrugs of NSAIDs: synthesis and biological evaluation

The free COOH group of conventional NSAIDs is a structural feature for non-selective cyclooxygenase (COX) inhibition and the molecular cause of their gastrointestinal (GI) toxicity. In this context, an in house database of synthesizable ester prodrugs of some well-known NSAIDs was developed by combining their -COOH group with -OH of a newly identified antioxidant 4-(1H-benzo[d]imidazol-2-yl)phenol (BZ). The antioxidant potential of BZ was unveiled through in silico PASS prediction and in vitro/in vivo evaluation. The in house database of NSAIDs-BZ prodrugs was first subjected to screening with our previously reported pharmacophore models of hCES1 (AAHRR.430) and hCES2 (AHHR.21) for determining hydrolytic susceptibility. Biotransformation behaviour of screened prodrugs was then assessed by using QM/MM and sterimol parameterization, followed by ADMET calculations to predict the drug likeness. On the basis of in silico results, five prodrugs were duly synthesized and the best three were subject to the in vivo evaluation for their anti-inflammatory, analgesic, antioxidant activities, and ulcerogenic index. Among these prodrugs, BN₂ and BN₅ displayed better anti-inflammatory and analgesics potential in comparison to their parent drugs. All the prodrugs were found to be gastro sparing in the rat model and significantly improved the levels of oxidative stress biomarkers in both blood plasma as well as gastric homogenate.

Interfraction physical dose variations in high-dose-rate brachytherapy for carcinoma cervix based on computed tomography image dataset to find the compatibility of the first fraction plan to treat successive fractions

Context

Due to limited resources and/or affordability by majority of the patients, many centers in low- and middle-income countries are still not able to adapt three-dimensional image-based brachytherapy planning in their routine practice.

Aim

The aim of the study was to see the feasibility of using computed tomography (CT)-based plan of the first fraction to treat successive fractions of intracavitary brachytherapy based on the estimation of the physical dosimetric differences between successive applications.

Materials and Methods

CT image-based brachytherapy plans of 38 patients who received three insertions of intracavitary application with high-dose-rate brachytherapy have been analyzed. Revised plans for the second and third insertions were generated by adapting dwell time and dwell position of the first insertion plan. The dose to point "A" and maximum doses to 2, 1, and 0.1 cc volumes of the rectum and bladder have been used for dosimetric comparison.

Results

The statistical differences of mean point "A" doses were observed insignificant except between original and revised plans for the second insertions. The dosimetric differences between consecutive original and revised plans for the bladder and rectum have not shown any significance except minimum dose to 0.1 cc volume of the rectum for the third insertions.

Conclusions

Dosimetric deviation for tumor and organs at risk is within acceptable limit while using CT image-based brachytherapy plan of the first fraction for treating successive fractions.

Mutant huntingtin impairs PNKP and ATXN3, disrupting DNA repair and transcription

How huntingtin (HTT) triggers neurotoxicity in Huntington's disease (HD) remains unclear. We report that HTT forms a transcription-coupled DNA repair (TCR) complex with RNA polymerase II subunit A (POLR2A), ataxin-3, the DNA repair enzyme polynucleotide-kinase-3'-phosphatase (PNKP), and cyclic AMP-response element-binding (CREB) protein (CBP). This complex senses and facilitates DNA damage repair during transcriptional elongation, but its functional integrity is impaired by mutant HTT. Abrogated PNKP activity results in persistent DNA break accumulation, preferentially in actively transcribed genes, and aberrant activation of DNA damage-response ataxia telangiectasia-mutated (ATM) signaling in HD transgenic mouse and cell models. A concomitant decrease in Ataxin-3 activity facilitates CBP ubiquitination and degradation, adversely impacting transcription and DNA repair. Increasing PNKP activity in mutant cells improves genome integrity and cell survival. These findings suggest a potential molecular mechanism of how mutant HTT activates DNA damage-response pro-degenerative pathways and impairs transcription, triggering neurotoxicity and functional decline in HD.

Potential neuroprotective role of astroglial exosomes against smoking-induced oxidative stress and HIV-1 replication in the central nervous system

INTRODUCTION

HIV-1-infected smokers are at risk of oxidative damage to neuronal cells in the central nervous system by both HIV-1 and cigarette smoke. Since neurons have a weak antioxidant defense system, they mostly depend on glial cells, particularly astrocytes, for protection against oxidative damage and neurotoxicity. Astrocytes augment the neuronal antioxidant system by supplying cysteine-containing products for glutathione synthesis, antioxidant enzymes such as SOD and catalase, glucose for antioxidant regeneration via the pentose-phosphate pathway, and by recycling of ascorbic acid. Areas covered: The transport of antioxidants and energy substrates from astrocytes to neurons could possibly occur via extracellular nanovesicles called exosomes. This review highlights the neuroprotective potential of exosomes derived from astrocytes against smoking-induced oxidative stress, HIV-1 replication, and subsequent neurotoxicity observed in HIV-1-positive smokers. Expert opinion: During stress conditions, the antioxidants released from astrocytes either via extracellular fluid or exosomes to neurons may not be sufficient to provide neuroprotection. Therefore, we put forward a novel strategy to combat oxidative stress in the central nervous system, using synthetically developed exosomes loaded with antioxidants such as glutathione and the anti-aging protein Klotho.

Substance abuse amongst the medical graduate students in a developing country

Background & objectives:

Substance abuse is found worldwide including among students. We carried out this study to estimate the prevalence of substance abuse among medical student studying in a medical college in north India.

Methods:

Using a validated questionnaire a cross-sectional survey was conducted among 230 undergraduate and postgraduate medical students in a private medical college.

Results:

The prevalence of substance abuse was 20.43 per cent (47/230) among medical students. An increase in substance abuse was observed in the latter years of medical education. A total of 43 of 47 (91.7%) students using these substances were aware of the ill effects. The most common reasons for substance use were relief from psychological stress (34/47, 72.4%) and occasional celebration (34/47, 72.4%). Of the 47 substance users, 28 (59.6%) made past attempts to quit the substance abuse.

Interpretation & conclusions:

Nearly one-fifth of medical students abuse at least one substance despite knowing the ill effects with the main predisposing factor being the psychological stress.

Effects of triphala and guggul aqueous extracts on inhibition of protein fibrillation and dissolution of preformed fibrils

Herbal preparations such as triphala and guggul aqueous extracts have ability to inhibit protein fibrillation which is known to be an important process responsible for many neurodegenerative and other diseases.

Evaluation of Spot Urinary Albumin-Creatinine Ratio as Screening Tool in Prediction of Pre-eclampsia in Early Pregnancy

Objective

The aim of this study was to establish whether a spot urinary albumin/creatinine ratio (ACR) measured between 20 and 28 weeks of gestation can predict subsequent pre-eclampsia in asymptomatic pregnant women.

Design

Prospective observational study.

Subjects

The patients included sixty-two women with singleton pregnancy, normal renal function and no evident proteinuria, attending antenatal clinics between 20 and 28 weeks of gestation in a tertiary care hospital.

Methods

The ACR was determined from midstream urine sample taken between 20 and 28 weeks of gestation. Estimation of albumin was done by immunoturbidimetric microalbumin method and creatinine by modified Jaffe's method.

Results

Incidence of pre-eclampsia in the study group was 12.90%. The cut-off value for ACR was taken as 35.5 mg/mol. The mean ACR in normotensive group was 19.26 ± 7.99, and in pre-eclampsia group it was 51.95 ± 18.78. For pre-eclampsia, screening in early pregnancy, spot ACR cut-off ≥35.5 mg/mol has sensitivity of 87.5%, specificity of 96.30%, PPV of 77.78% and NPV of 98.11%.

Conclusions

Spot urinary ACR values are higher in asymptomatic women in early pregnancy, who developed pre-eclampsia later on. When measured early in the second trimester, an ACR ≥ 35.5 mg/mmol predicted pre-eclampsia well before the onset of clinical manifestations with high sensitivity and specificity. It can be used as a good screening tool for predicting pre-eclampsia in early pregnancy.

Glucocorticoids increase skeletal muscle NF-κB inducing kinase (NIK): links to muscle atrophy

Glucocorticoids (GC) are a frontline therapy for numerous acute and chronic diseases because of their demonstrated efficacy at reducing systemic inflammation. An unintended side effect of GC therapy is the stimulation of skeletal muscle atrophy. Pathophysiological mechanisms responsible for GC-induced skeletal muscle atrophy have been extensively investigated, and the ability to treat patients with GC without unintended muscle atrophy has yet to be realized. We have reported that a single, standard-of-care dose of Methylprednisolone increases in vivo expression of NF-κB-inducing kinase (NIK), an important upstream regulatory kinase controlling NF-κB activation, along with other key muscle catabolic regulators such as Atrogin-1 and MuRF1 that induce skeletal muscle proteolysis. Here, we provide experimental evidence that overexpressing NIK by intramuscular injection of recombinant human NIK via adenoviral vector in mouse tibialis anterior muscle induces a 30% decrease in the average fiber cross-sectional area that is associated with increases in mRNA expression of skeletal muscle atrophy biomarkers MuRF1, Atrogin-1, myostatin and Gadd45. A single injection of GC induced NIK mRNA and protein within 2 h, with the increased NIK localized to nuclear and sarcolemmal locations within muscle fibers. Daily GC injections induced skeletal muscle fore limb weakness as early as 3 days with similar atrophy of muscle fibers as observed with NIK overexpression. NIK overexpression in primary human skeletal muscle myotubes increased skeletal muscle atrophy biomarkers, while NIK knockdown significantly attenuated GC-induced increases in NIK and Atrogin-1. These results suggest that NIK may be a novel, previously unrecognized mediator of GC-induced skeletal muscle atrophy.

Anthropometry based prediction of dominant hand grip strength in Indian office going females

Background: Physical strength can be measured by means of hand grip strength. It is of great use as a functional index of nutritional status.Aims and Objectives: Physical strength can be measured by means of hand grip strength. It is of great use as a functional index of nutritional status. Association of hand grip strength with other variables is studied in order to predict the strength outcomes and to study the effect of factors that can influence hand grip strength performance.Materials and Methods: In the present study the correlations of dominant hand grip strength and anthropometric and body composition variables namely, height, weight, forearm length, arm length, hand breadth, body mass index (BMI), and fat mass in randomly selected 375 unrelated, normal, healthy Indian office going females of age 20-60 years with mean height and weight of 154.12 ± 5.94 cm and 59.86 ± 10.94 kg respectively has been studied.Result: Hand grip strength of the females varied from 17 kg to 32 kg with a mean of 23.86 ± 2.74 kg. The comparison of age, height, weight, forearm length, arm length, hand breadth, and fat mass with the hand grip strength showed good correlation (p<0.01). The best fit model for handgrip prediction when age, height, weight and hand breadth for this population were considered is Hand Grip = -12.260-0.13*Age+0.16*Height+0.13*Weight+1.02*Hand breadth.Conclusion: It may be concluded that hand grip strength has close association with the anthropometric measurements and body composition variables and using these parameters grip strength can be predicted in Indian office going females.Asian Journal of Medical Sciences Vol.7(5) 2016 58-62

A Single-Centre Experience of Obstetric Acute Kidney Injury

BACKGROUND

Acute kidney injury (AKI) is a clinical syndrome characterized by a sudden decline in glomerular filtration rate leading to decreased excretion of nitrogenous waste products. It continues to be a common problem in developing countries.

AIMS

The aim of this study was to understand AKI characteristics in pregnancy and identify the factors related to its unfavorable outcome.

STUDY DESIGN

A prospective cross-sectional study.

METHODS

This prospective study was conducted between January 2013 and May 2014. In total 570 women with AKI were referred to the Kidney Institute during this period, out of which 52 patients with obstetrics AKI were included in this study.

RESULTS

Incidence of obstetric AKI was 9.12 %. Their age varied from 19 to 34 years, with an average of 26.2 years. About 42(80.8 %) patients had not received antenatal care. The main causes of AKI were obstetric hemorrhage (38.46 %) and puerperal sepsis (15.38 %). The outcome was favorable with complete renal function recovery in 55.76 % patients. Four (7.69 %) patients became dialysis dependent. Maternal mortality was 32.69 %.

CONCLUSION

Obstetric AKI is a critical situation in developing countries. Lack of antenatal care (80.8 %) is a major contributing factor for obstetric-related complications leading to renal failure. Obstetric hemorrhage (38.46 %) is the most common cause of obstetric AKI. Late referral in 18 (34.61 %), puerperal sepsis in six (33.33 %), obstetric hemorrhage in five (27.77 %) and combined sepsis and hemorrhage in five (27.77 %) are the common contributing factors leading to its unfavorable outcomes as maternal morbidity and mortality. Hence, a multidisciplinary approach is warranted to prevent such an avoidable complication.

Amniotic fluid: Source of trophic factors for the developing intestine

The gastrointestinal tract (GIT) is a complex system, which changes in response to requirements of the body. GIT represents a barrier to the external environment. To achieve this, epithelial cells must renew rapidly. This renewal of epithelial cells starts in the fetal life under the influence of many GIT peptides by swallowing amniotic fluid (AF). Development and maturation of GIT is a very complex cascade that begins long before birth and continues during infancy and childhood by breast-feeding. Many factors like genetic preprogramming, local and systemic endocrine secretions and many trophic factors (TF) from swallowed AF contribute and modulate the development and growth of the GIT. GIT morphogenesis, differentiation and functional development depend on the activity of various TF in the AF. This manuscript will review the role of AF borne TF in the development of GIT.

Inside-Out Signaling Pathways from Nuclear Reactive Oxygen Species Control Pulmonary Innate Immunity

The airway mucosa is responsible for mounting a robust innate immune response (IIR) upon encountering pathogen-associated molecular patterns. The IIR produces protective gene networks that stimulate neighboring epithelia and components of the immune system to trigger adaptive immunity. Little is currently known about how cellular reactive oxygen species (ROS) signaling is produced and cooperates in the IIR. We discuss recent discoveries about 2 nuclear ROS signaling pathways controlling innate immunity. Nuclear ROS oxidize guanine bases to produce mutagenic 8-oxoguanine, a lesion excised by 8-oxoguanine DNA glycosylase1/AP-lyase (OGG1). OGG1 forms a complex with the excised base, inducing its nuclear export. The cytoplasmic OGG1:8-oxoG complex functions as a guanine nucleotide exchange factor, triggering small GTPase signaling and activating phosphorylation of the nuclear factor (NF)x03BA;B/RelA transcription factor to induce immediate early gene expression. In parallel, nuclear ROS are detected by ataxia telangiectasia mutated (ATM), a PI3 kinase activated by ROS, triggering its nuclear export. ATM forms a scaffold with ribosomal S6 kinases, inducing RelA phosphorylation and resulting in transcription-coupled synthesis of type I and type III interferons and CC and CXC chemokines. We propose that ATM and OGG1 are endogenous nuclear ROS sensors that transmit nuclear signals that coordinate with outside-in pattern recognition receptor signaling, regulating the IIR.

Ataxia telangiectasia mutated kinase mediates NF-κB serine 276 phosphorylation and interferon expression via the IRF7-RIG-I amplification loop in paramyxovirus infection

Respiratory syncytial virus (RSV) is a primary etiological agent of childhood lower respiratory tract disease. Molecular patterns induced by active infection trigger a coordinated retinoic acid-inducible gene I (RIG-I)-Toll-like receptor (TLR) signaling response to induce inflammatory cytokines and antiviral mucosal interferons. Recently, we discovered a nuclear oxidative stress-sensitive pathway mediated by the DNA damage response protein, ataxia telangiectasia mutated (ATM), in cytokine-induced NF-κB/RelA Ser 276 phosphorylation. Here we observe that ATM silencing results in enhanced single-strand RNA (ssRNA) replication of RSVand Sendai virus, due to decreased expression and secretion of type I and III interferons (IFNs), despite maintenance of IFN regulatory factor 3 (IRF3)-dependent IFN-stimulated genes (ISGs). In addition to enhanced oxidative stress, RSV replication enhances foci of phosphorylated histone 2AX variant (γH2AX), Ser 1981 phosphorylation of ATM, and IKKγ/NEMO-dependent ATM nuclear export, indicating activation of the DNA damage response. ATM-deficient cells show defective RSV-induced mitogen and stress-activated kinase 1 (MSK-1) Ser 376 phosphorylation and reduced RelA Ser 276 phosphorylation, whose formation is required for IRF7 expression. We observe that RelA inducibly binds the native IFN regulatory factor 7 (IRF7) promoter in an ATM-dependent manner, and IRF7 inducibly binds to the endogenous retinoic acid-inducible gene I (RIG-I) promoter. Ectopic IRF7 expression restores RIG-I expression and type I/III IFN expression in ATM-silenced cells. We conclude that paramyxoviruses trigger the DNA damage response, a pathway required for MSK1 activation of phospho Ser 276 RelA formation to trigger the IRF7-RIG-I amplification loop necessary for mucosal IFN production. These data provide the molecular pathogenesis for defects in the cellular innate immunity of patients with homozygous ATM mutations.

IMPORTANCE

RNA virus infections trigger cellular response pathways to limit spread to adjacent tissues. This "innate immune response" is mediated by germ line-encoded pattern recognition receptors that trigger activation of two, largely independent, intracellular NF-κB and IRF3 transcription factors. Downstream, expression of protective antiviral interferons is amplified by positive-feedback loops mediated by inducible interferon regulatory factors (IRFs) and retinoic acid inducible gene (RIG-I). Our results indicate that a nuclear oxidative stress- and DNA damage-sensing factor, ATM, is required to mediate a cross talk pathway between NF-κB and IRF7 through mediating phosphorylation of NF-κB. Our studies provide further information about the defects in cellular and innate immunity in patients with inherited ATM mutations.