Nitish Rai

Urinary melamine: Proposed parameter of melamine adulteration of food

Melamine is widely being reported as a food adulterant. Although its toxicity is currently recognized, melamine adulterations of food items are ongoing for falsely inflating the protein content of the food. Melamine alone or in combination with cyanuric acid or uric acid causes nephrotoxicity, and melamine-induced nephrotoxicity is now a global concern. It has been proven that when consumed, melamine is metabolized at a slower rate and excreted unchanged in urine. There is every possibility that when individuals consume melamine-adulterated food items, the melamine may be excreted unchanged in the urine. Therefore, melamine estimation in urine may be a yardstick to check for melamine adulteration of food items. In the present review, recent literature on this subject is analyzed justifying.

Exploration of Novel Anti-Oxidant Protein Sestrin in Frailty Syndrome in Elderly

Frailty in elderly is very much familiar with a decline in the musculoskeletal system. Muscle degeneration in the lower organism was observed due to loss of anti-oxidant protein Sestrin. The aim of the study is to determine the level of Sestrin1 and Sestrin2 in the serum of frail and non-frail elderly to associate their impact in frailty syndrome. Subjects with age ≥ 65 years were enrolled from Geriatric Medicine OPD of All India Institute of Medical Sciences, New Delhi (N= 92). Among them, 51 subjects were identified as frail and rest 41 were regarded as non-frail according to “deficit accumulation model of Rockwood.” The study was performed by surface plasmon resonance and validated by western blot. Sestrin1 and Sestrin2 were found to be significantly reduced in frail compare to non-frail elderly. Furthermore, even after the adjustment for age, gender and education, the level of Sestrin1 and Sestrin2 remain significantly lower across the groups. The Sestrin1 level was significantly lower in various categories like age, gender, BMI, education, ADL, number of co-morbidity along with other clinico-pathological features. ROC analysis also revealed the distinction of frail and non-frail in respect to serum Sestrin1 and Sestrin2. This study highlighted the new and promising role of serum Sestrin in frail and non-frail elderly. In future, it can be utilized as molecular marker to assess the potential diagnostic value for clinical purpose.

Relative Alterations in Blood-Based Levels of Sestrin in Alzheimer’s Disease and Mild Cognitive Impairment Patients

Sestrins (sesn) are highly conserved proteins that play an important neuroprotective role, in part as a consequence of their antioxidative capacity, which prevents reactive oxygen species formation. In this study, we evaluated the concentrations of sesn1 and sesn2 in the serum of 41 Alzheimers disease (AD) patients, 27 mild cognitive impairment (MCI), and 60 elderly controls, by surface plasmon resonance, which was validated by using western blot. Moreover, the mRNA level of sestrins in all the study groups was determined by real time polymerase chain reaction. The results showed significant overexpression of serum sesn2 protein and mRNA levels in the AD group compared to MCI and elderly control groups. A difference in serum sesn2 concentration between MCI and the control group was also evident. ROC analysis showed highly sensitive, selective cutoff values for sens2 in the differentiation of AD, MCI, and controls. No significant difference in sesn1 level was observed among the study groups. This study highlights the important role of sesn2 in the progression of the AD, indicating its potential utility as a protein marker in this devastating disease.

Serum 5-LOX: a progressive protein marker for breast cancer and new approach for therapeutic target

Lipoxygenase (LOX) pathway has emerged to have a role in carcinogenesis. There is an evidence that both 12-LOX and 5-LOX have procarcinogenic role. We have previously reported the elevated level of serum 12-LOX in breast cancer patients. This study evaluated the serum level of 5-LOX in breast cancer patients and its in vitro inhibition assessment with peptide inhibitor YWCS. The level of 5-LOX was determined by surface plasmon resonance (SPR). The peptide inhibitor of 5-LOX was designed by molecular modeling and kinetic assay was performed by spectrophotometry. The siRNA mediated 5-LOX gene silencing was performed to investigate the effect on proliferation of MDA-MB-231, breast cancer cell line. The serum 5-LOX level in breast cancer (5.69±1.97ng/µl) was almost 2-fold elevated compared to control (3.53±1.0ng/µl) (P < 0.0001). The peptide YWCS had shown competitive inhibitory effects with IC50, 2.2 µM and dissociation constant (K D), 4.92×10(-8) M. The siRNA mediated knockdown of 5-LOX, resulted in the decreased gene expression for 5-LOX and increased cell death in MDA-MB-231 cell line and thereby play a key role in reducing tumor proliferation. Thus, it can be concluded that 5-LOX is one of the potential serum protein marker for breast cancer and a promising therapeutic target for the same.

5-LOX in Alzheimer’s Disease: Potential Serum Marker and In Vitro Evidences for Rescue of Neurotoxicity by Its Inhibitor YWCS

The inflammatory process plays a key role in neurodegenerative disorder. The inflammatory molecule, 5-lipooxygenase (5-LOX), protein is involved in the pathologic phenotype of Alzheimer’s disease (AD) which includes Aβ amyloid deposition and tau hyperphosphorylation. This study determined the level of 5-LOX in serum of AD patients, mild cognitive impairment (MCI) patients, and the normal elderly, and the rescue effect by YWCS, a peptide inhibitor of 5-LOX on neurotoxicity by Aβ amyloid25–35 (Aβ25–35) in neuroblastoma cells. The concentration of serum 5-LOX was estimated by surface plasmon resonance and western blot. The neuroprotective effect of 5-LOX peptide inhibitor YWCS in Aβ25–35-induced neurotoxicity was analyzed by MTT assay and western blotting. We found significant upregulated serum 5-LOX in AD patients and also in MCI patients compared to the normal control group. The peptide inhibitor of 5-LOX, YWCS, prevented the neurotoxic effect of Aβ25–35 by reducing the expression of γ-secretase as well as p-Tau181 in SH-SY5Y cells. However, YWCS was nontoxic towards normal HEK cells. The differential expression of serum 5-LOX among the study groups suggests it can be one of potential serum protein marker and a therapeutic regimen for AD and MCI. The negative correlation with neuropsychological parameters, i.e., MoCA and HMSE, increases its importance and makes it useful during the clinical setup which is very needful in developing countries. Peptide YWCS can serve as a new platform as a 5-LOX inhibitor which can prevent neurotoxicity developed in AD.

Reversible bioprosthetic valve thrombosis from eosinophilia

A 31-year-old man with a mitral bioprosthetic valve presented with recent worsening of exertional dyspnoea 7 years after the mitral valve replacement. Evaluation revealed an increased gradient across the thickened mitral bioprosthetic valve leaflets. Marked eosinophilia was present and was considered as a putative cause for bioprosthetic valve thrombosis. The treatment with systemic corticosteroids and oral anticoagulation led to complete resolution of symptoms with significant decrease in mitral bioprosthetic valve gradient and leaflet thinning. The case is reported to highlight the fact that eosinophilia may cause reversible bioprosthetic valve thrombosis.

A study of recombinant human sestrin 1 and sestrin 2 proteins produced in a prokaryotic system

Sestrins are highly conserved stress-inducible proteins capable of suppressing the production of ROS and signalling through mTORC1. Here we report a study of human sestrin1 (sesn1) and sestrin2 (sesn2) proteins produced in a pET28+ vector based prokaryotic system. Mass spectrometry analysis, western blot and surface plasmon resonance (SPR) of affinity purified sesn1 and sesn2 proteins confirmed their identity; biophysical characteristics were observed using circular dichroism (CD) showing that sesn1 and sesn2 have a predominant α-helical structure. Here we describe a simple, one step purification process to purify a large amount of sestrin proteins with significant yield. Further study of recombinant human sestrins may further facilitate the understanding of their roles in eukaryotic cells.

Recurrent prosthetic heart valve thrombosis secondary to eosinophilia: a missed diagnosis

Prosthetic heart valve thrombosis (PHVT) is a major cause of morbidity and mortality in patients with mechanical heart valves. We present a case of recurrent PHVT associated with eosinophilia. A 17-year-old girl underwent aortic and mitral valve replacement for rheumatic heart disease. Over a period of 4 years, she had four episodes of PHVT despite oral anticoagulation with adequate INR. Her investigations revealed eosinophilia which was missed during the previous episodes. No further episodes of PHVT occurred after treatment of eosinophilia with steroids on limited follow-up.

SESTRIN LEVELS IN PATIENTS DIAGNOSED WITH MILD COGNITIVE IMPAIRMENT AND ALZHEIMER’S DISEASE: A POTENTIAL MARKER

Figure 1. Floating bar diagramwith line at mean showing the concentration of serum sesn2 (A) and sesn1 (B) in elderly control (n1⁄4 60), MCI (n1⁄4 27), and AD (n 1⁄4 41) subjects. These serum concentrations, estimated by SPR technology, showed increased levels of sesn2 in MCI and AD but not in elderly controls (p < 0.0001) while there was no significant difference for sesn1 in elderly controls, MCI, and AD. Nicholas J. Ashton, Alejo J. Nevado-Holgado, Steven Lynham, Malcolm Ward, Veer Bala Gupta, Pratishtha Chatterjee, Kathryn Gooze, Eugene Hone, Steve Pedrini, Ashley I. Bush, Christopher C. Rowe, Victor L. L. Villemagne, David Ames, Colin L. Masters, Dag Aarsland, Simon Lovestone, Ralph N. Martins, Abdul Hye, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, United Kingdom; King’s College London, London, United Kingdom; University of Oxford, Oxford, United Kingdom; Proteome Sciences plc, London, United Kingdom; School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia; Cooperative Research Centre for Mental Health, Melbourne, Australia; KaRa Institute of Neurological Diseases, Sydney, Australia; Macquarie University, Sydney, Australia; KaRa Institute of Neurological Diseases, Melbourne, Australia; Edith Cowan University of Medical Sciences, Joondalup, Australia; Edith Cowan University, Perth, Australia; AIBL Research Group, Perth andMelbourne, Australia; The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; The University of Melbourne, Melbourne, Australia; University of Melbourne, Melbourne, Australia; Austin Health, Melbourne, Australia; The University of Melbourne, Parkville, Australia; University of Melbourne, Austin Health, Melbourne, Australia; National Ageing Research Institute, Melbourne, Australia; The Florey Institute of Neuroscience and Mental Health, Parkville, Australia; Karolinska Institutet, Department of Neurobiology, Care Sciences and Society, Stockholm, Sweden; Stavanger University Hospital, Stavanger, Norway; School of Psychiatry and Clinical Neurosciences, University of Western Australia, Perth, Australia; Australian Alzheimer’s Research Foundation, Perth, Australia; Sir James McCusker Alzheimer’s Disease Research Unit (Hollywood Private Hospital), Perth, Australia; Edith Cowan University, Joondalup, Australia; NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation, London, United Kingdom. Contact e-mail: nicholas.1.ashton@kcl.ac.uk