Anand Narayan Singh

Iron oxide nanoparticles and magnetic field exposure promote functional recovery by attenuating free radical-induced damage in rats with spinal cord transection

Background Iron oxide nanoparticles (IONPs) can attenuate oxidative stress in a neutral pH environment in vitro. In combination with an external electromagnetic field, they can also facilitate axon regeneration. The present study demonstrates the in vivo potential of IONPs to recover functional deficits in rats with complete spinal cord injury. Methods The spinal cord was completely transected at the T11 vertebra in male albino Wistar rats. Iron oxide nanoparticle solution (25 μg/mL) embedded in 3% agarose gel was implanted at the site of transection, which was subsequently exposed to an electromagnetic field (50 Hz, 17.96 μT for two hours daily for five weeks). Results Locomotor and sensorimotor assessment as well as histological analysis demonstrated significant functional recovery and a reduction in lesion volume in rats with IONP implantation and exposure to an electromagnetic field. No collagenous scar was observed and IONPs were localized intracellularly in the immediate vicinity of the lesion. Further, in vitro experiments to explore the cytotoxic effects of IONPs showed no effect on cell survival. However, a significant decrease in H2O2-mediated oxidative stress was evident in the medium containing IONPs, indicating their free radical scavenging properties. Conclusion These novel findings indicate a therapeutic role for IONPs in spinal cord injury and other neurodegenerative disorders mediated by reactive oxygen species.

CpG Hypermethylation of the C-myc Promoter by dsRNA Results in Growth Suppression

Deregulation of the c-myc proto-oncogene plays an important role in carcinogenesis. It is, therefore, commonly found to be overexpressed in various types of tumors. Downregulation of c-myc expression assumes great importance in tumor therapy because of its ability to promote and maintain cancer stem cells. Apart from post-transcriptional gene silencing (PTGS), siRNAs have also been shown to cause transcriptional gene silencing (TGS) through epigenetic modifications of a gene locus. This approach can potentially be used to silence genes for longer periods and at a much lesser dosage than PTGS. In this study, we have examined the effect of transfection of a novel siRNA directed against a CpG island encompassing the CT-I(2) region in the P2 promoter of c-myc in U87MG and other cell lines. Transient transfection with this siRNA resulted in c-myc promoter CpG hypermethylation and decreased expression of c-myc (both mRNA and protein) and its downstream targets. A decrease was also observed in the expression of some stemness markers (oct-4 and nanog). Stable transfection also confirmed the promoter CpG hypermethylation and reduced c-myc expression along with reduced cell proliferation and an increase in apoptosis and senescence. A significant decrease in c-myc levels was also observed in three other cancer cell lines after transient transfection under similar conditions. Thus this novel siRNA has the capability of becoming an effective therapeutic tool in malignancies with overexpression of c-myc and may be of particular use in the eradication of recalcitrant cancer stem cells.

Expression pattern of PRM2, HSP90 and WNT5A in male partners of couples experiencing idiopathic recurrent miscarriages.

Recurrent pregnancy loss affects approximately 3–5% of couples attempting to have a child. It is defined as the occurrence of two or more consecutive pregnancy failures before 20 weeks of gestation. In about 40% of cases, the cause remains unknown and are defined as idiopathic recurrent miscarriages (iRM) (Stephenson and Kutteh 2007). However, most of these diagnostics tests are performed in the female partner, with the male’s contribution remaining relatively underexplored (only paternal karyotyping is done). Paternal factor may be the underlying aetiology in RM (Lalancette et al. 2008) and molecular abnormalities in sperm may have an adverse effect on embryonic development. Certain portion of sperm genome remains transcriptionally active and codes for transcripts which are of paramount developmental importance (Krawetz 2005; Gil-Villa et al. 2010). Among these, the role of long-lived sperm RNA which are not translated is controversial. Sperm possess a remarkable set of long-lived messenger RNAs (mRNAs) that have been hypothesized to be required for embryogenesis. Some of these spermatozoal mRNAs are also found in zygote, indicating that these transcripts may be functionally critical during embryonic development (Ostermeier et al. 2004). The delivery of certain sperm transcripts to the oocyte, which could translate to proteins, may be critical for the early stages of embryogenesis and/or implantation. In the vast population of mRNA, transcripts of winglesstype MMTV integration site family, member 5A (WNT5A), heat shock protein 90 (HSP90) and protamine 2 (PRM2) are present in human mature spermatozoa as examined by microarray and serial analysis gene expression (SAGE) technology (Wykes et al. 2000; Zhao et al. 2006). These genes

Pancreaticojejunostomy: Does the technique matter? A randomized trial

Despite a large number of studies, the ideal technique of pancreaticojejunostomy (PJ) after pancreaticoduodenectomy (PD) remains debatable. We compared the two most common techniques of PJ (duct‐to‐mucosa and dunking) in a randomized trial.

Increased expression of platelet-derived growth factor associated protein-1 is associated with PDGF-B mediated glioma progression

The current treatment therapies available for malignant gliomas are inadequate. There is an urgent need to develop more effective therapies by characterizing the molecular pathogenesis of the disease. Over expression of platelet-derived growth factor (PDGF) ligands and receptors have been reported in malignant gliomas. Platelet-derived growth factor associated protein-1 (PDAP-1) is reported to modulate the mitogenic activity of PDGF ligands, but to date, there is no information concerning its role in PDGF-mediated glioma cell proliferation. This study aimed to characterize the role of PDAP-1 in PDGF-mediated glioma proliferation. The expression of PDAP-1 was observed to be significantly increased (p<0.05) in grade IV glioma tissue and cell lines compared to grade III. siRNA-mediated knockdown of PDAP-1 reduced the expression of PDGF-B and its downstream genes (Akt1/Protein kinase B (PKB) and phosphoinositide-dependent kinase-1 (PDK1) by up to 50%. In PDAP-1 knockdown glioma cells, more than a twofold reduction was also observed in the level of phosphorylated Akt. Interestingly, knockdown of PDAP-1 in combination with PDGF-B antibody inhibited glioma cell proliferation through activation of Caspase 3/7 and 9. We also demonstrate that PDAP-1 co-localizes with PDGF-B in the cytoplasm of glioma cells, and an interaction between both of the proteins was established. Collectively, these findings suggest that the expression of PDAP-1 is associated with disease malignancy, and its inhibition reduced the proliferation of malignant glioma cells through down-regulation of PDGF-B/Akt/PDK1 signaling. Thus, this study establishes PDAP-1 as an effecter of PDGF signaling in glioma cells and suggests that it could also be a promising therapeutic target.

Single-stage laparoscopic common bile duct exploration and cholecystectomy versus two-stage endoscopic stone extraction followed by laparoscopic cholecystectomy for patients with gallbladder stones with common bile duct stones: systematic review and meta-analysis of randomized trials with trial sequential analysis

BackgroundThe ideal management of common bile duct (CBD) stones associated with gall stones is a matter of debate. We planned a meta-analysis of randomized trials comparing single-stage laparoscopic CBD exploration and cholecystectomy (LCBDE) with two-stage preoperative endoscopic stone extraction followed by cholecystectomy (ERCP + LC).MethodsWe searched the Pubmed/Medline, Web of science, Science citation index, Google scholar and Cochrane Central Register of Controlled trials electronic databases till June 2017 for all English language randomized trials comparing the two approaches. Statistical analysis was performed using Review Manager (RevMan) [Computer program], Version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014 and results were expressed as odds ratio for dichotomous variables and mean difference for continuous. p value ≤ 0.05 was considered significant. Trial sequential analysis (TSA) was performed using TSA version 0.9.5.5 (Copenhagen: The Copenhagen Trial Unit, Centre for Clinical Intervention Research, 2016). PROSPERO trial registration number is CRD42017074673.ResultsA total of 11 trials were included in the analysis, with a total of 1513 patients (751-LCBDE; 762-ERCP + LC). LCBDE was found to have significantly lower rates of technical failure [OR 0.59, 95% CI (0.38, 0.93), p = 0.02] and shorter hospital stay [MD − 1.63, 95% CI (− 3.23, − 0.03), p = 0.05]. There was no significant difference in mortality [OR 0.37, 95% CI (0.09, 1.51), p = 0.17], morbidity [OR 0.97, 95% CI (0.70, 1.33), p = 0.84], cost [MD − 379.13, 95% CI (− 784.80, 111.2), p = 0.13] or recurrent/retained stones [OR 1.01, 95% CI (0.38, 2.73), p = 0.98]. TSA showed that although the Z-curve crossed the boundaries of conventional significance, the estimated information size is yet to be achieved.ConclusionsSingle-stage LCBDE is superior to ERCP + LC in terms of technical success and shorter hospital stay in good-risk patients with gallstones and CBD stones, where expertise, operative time and instruments are available.

Duct-to-mucosa versus dunking techniques of pancreaticojejunostomy after pancreaticoduodenectomy: Do we need more trials? A systematic review and meta-analysis with trial sequential analysis

Pancreaticojejunostomy (PJ is the most widely used reconstruction technique after pancreaticoduodenectomy. Despite several randomized trials, the ideal technique of pancreaticojejunostomy remains debatable. We planned a meta‐analysis of randomized trials comparing the two most common techniques of PJ (duct‐to‐mucosa and dunking) to identify the best available evidence in the current literature.

An Alternative Approach to Life-Threatening Gastrointestinal Bleeding After Corrosive Ingestion

Massive gastrointestinal bleeding after corrosive intake is a rare complication that generally mandates a surgical intervention for control. Angioembolization for control of gastrointestinal bleeding in the setting of acute corrosive injury has not been described. Here, we present our experience of a case of acute corrosive injury presenting with massive upper gastrointestinal bleeding in the delayed phase which was successfully managed by angioembolization. We discuss the case in light of the literature available and describe markers which may serve to identify potential candidates for angioembolization.

Presentation and Management of Pseudoaneurysmogastric Fistula: A Life Threatening Emergency.

ABSTRACT Pseudoaneurysmogastric fistula is a rare consequence of pseudoaneurysms occurring in the vicinity of stomach. They are the result of pseudoaneurysms eroding into the stomach, and represent a life threatening emergency. Urgent surgical intervention is often necessary to salvage the patient. Data regarding the presentation and management of this condition is sparse. Herein, we present our experience with four cases of pseudoaneurysmogastric fistula, their clinical context, presentation, management and outcomes. We attempt to outline an algorithm for the diagnosis and management of this unusual complication.

Transcriptional modulation of HIV-1C LTR promoter

Background All current anti-HIV1 therapies target the viral proteins or RNA; however targeting HIV1 at the transcriptional level of the integrated provirus has been less explored. In India, AIDS is commonly caused by HIV-1C compared to HIV-1B in developed countries. HIV1-5’LTR acts as a promoter and shows sequence variation among different clades. Transcriptional gene silencing (TGS) is a method wherein dsRNA targeting the promoter/ enhancer of a gene are used to down regulate its expression.