manoj kumar - Academia.edu (original) (raw)

Papers by manoj kumar

Stem Cells and Development, 2009

The ability to study the characteristics of serotonin release from human serotonergic neurons is ... more The ability to study the characteristics of serotonin release from human serotonergic neurons is valuable both in terms of understanding disease pathology and in trying to understand how drugs that affect the serotonergic system alter neurotransmitter release. There is, however, no good in vitro system to model human serotonergic neurons. Although human embryonic stem (hES) cells offer an attractive model system, the derivation of serotonergic neurons from these cells has remained at a low efficiency. To address this problem, Nestin positive precursors from HUES7 hES cell line were first generated. These Nestin positive cells when terminally differentiated gave rise to 20% MAP-2 positive neurons. A high percentage…

Stem Cells and Development, 2007

In the central nervous system (CNS), generation of phenotypic diversity within the neuronal linea... more In the central nervous system (CNS), generation of phenotypic diversity within the neuronal lineage is precisely regulated in a spatial and temporal fashion. Neural basic helix-loop-helix (bHLH) transcription factors are cell intrinsic factors that control commitment to neuronal lineage and play an important role in neuronal cell type specification. The ability to differentiate human embryonic stem (hES) cells into neurons provides a good model system to address human neuronal specification. Previous studies have shown neurogenin-2 (Ngn2) to be involved in the development of mesencephalic dopaminergic neurons. Toward the goal of correlating neuronal phenotype with early gene expression pattern, we have characterized the expression of Ngn2 during hES cell differentiation. Our results show that treatment of embryoid bodies (EBs) with retinoic acid (RA) leads to the greatest proportion of tyrosine hydroxylase (TH)-positive cells followed by vasoactive intestinal peptide (VIP)-treated EBs as compared to untreated EBs. This increase in the proportion of TH-positive neurons was correlated with the unique morphology of RA-treated aggregates and the spatial delocalization of the expression of Ngn2 within the EB. Neurospheres derived from RA-treated EBs contained many nestin-positive cells within regions that expressed Ngn2. We show that the extent of nestin-positive cells that arise from the region of Ngn2 expression is correlated with the appearance of TH-positive neurons. Our results show for the first time the expression of Ngn2 during the differentiation of hES cells.

Stem Cell Reviews, 2008

Ischaemic stroke is a syndrome characterized by rapid onset of neurological injury due to interru... more Ischaemic stroke is a syndrome characterized by rapid onset of neurological injury due to interruption of blood flow to the brain. Widespread neuronal damage throughout the CNS has been shown to cause marked and multifarious functional impairments in the ischaemic brain. Recent advances as enumerated above have propelled acute ischaemic stroke management into a therapeutic era. However, once the damage from a stroke event has maximized, little can be done to recover premorbid function. Experimental animal data suggests that stem cell therapy may be an effective alternate to the conventional disease management strategies of ischaemic stroke. Therefore, the present review focuses on detailing the scope of stem cell therapy in the treatment of ischaemic stroke.

Semiconductor Science and Technology, 2013

PROTEOMICS, 2003

Although widely distributed in eukaryotic cells glycoproteins appear to be rare in prokaryotic or... more Although widely distributed in eukaryotic cells glycoproteins appear to be rare in prokaryotic organisms. The prevalence of the misconception that bacteria do not glycosylate their proteins has been a subject matter of discussion for a long time. Glycoconjugates that are linked to proteins or peptides, generated by the ribosomal translational mechanism have been reported only in the last two to three decades in a few prokaryotic organisms. Most studied prokaryotic glycoproteins are the S-layer glycoproteins of Archeabacteria. Apart from these, membrane-associated, surface-associated, secreted glycoproteins and exoenzymes glycoproteins are also well documented in both, Archea and Eubacteria. From the recent literature, it is now clear that prokaryotes are capable of glycosylating proteins. In general, prokaryotes are deprived of the cellular organelles required for glycosylation. In prokaryotes many different glycoprotein structures have been observed that display much more variation than that observed in eukaryotes. Besides following similar mechanisms in the process of glycosylation, prokaryotes have also been shown to use mechanisms that are different from those found in eukaryotes. The knowledge pertaining to the functional aspects of prokaryotic glycoproteins is rather scarce. This review summarizes developments and understanding relating to characteristics, synthesis, and functions of prokaryotic glycoproteins. An extensive summary of glycosylation that has been reported to occur in bacteria has also been tabulated. Various possible applications of these diverse biomolecules in biotechnology, vaccine development, pharmaceutics and diagnostics are also touched upon.

Pramana, 2000

Thomson scattering technique based on high power laser has already proved its superoirity in meas... more Thomson scattering technique based on high power laser has already proved its superoirity in measuring the electron temperature´Ì µ and density´Ò µ in fusion plasma devices like tokamaks. The method is a direct and unambiguous one, widely used for the localised and simultaneous measurements of the above parameters. In Thomson scattering experiment, the light scattered by the plasma electrons is used for the measurements. The plasma electron temperature is measured from the Doppler shifted scattered spectrum and density from the total scattered intensity. A single point Thomson scattering system involving a É-switched ruby laser and PMTs as the detector is deployed in ADITYA tokamak to give the plasma electron parameters. The system is capable of providing the parameters Ì from 30 eV to 1 keV and Ò from ¢ ½¼ ½¾ Ñ ¿ 5 ¢½¼ ½¿ Ñ ¿ . The system is also able to give the parameter profile from the plasma center ( ¼ cm) to a vertical position of ·¾¾ cm to ½ cm, with a spatial resolution of 1 cm on shot to shot basis. This paper discusses the initial measurements of the plasma temperature from ADITYA.

Plant Physiology and Biochemistry, 2012

The protective role of exogenously supplied selenium (Se) and polyamines (PAs) such as putrescine... more The protective role of exogenously supplied selenium (Se) and polyamines (PAs) such as putrescine (Put) and spermine (Spm) in detoxifying the cadmium (Cd) induced toxicity was studied in the marine red alga Gracilaria dura in laboratory conditions. The Cd exposure (0.4 mM) impede the growth of alga while triggering the reactive oxygen species (ROS viz. O(2)(•-) and H(2)O(2)) generation, inhibition of antioxidant system, and enhancing the lipoxygenase (LOX) activity, malondialdehyde (MDA) level and demethylation of DNA. Additions of Se (50 μM) and/or Spm (1 mM) to the culture medium in contrast to Put, efficiently ameliorated the Cd toxicity by decreasing the accumulation of ROS and MDA contents, while restoring or enhancing the level of enzymatic and nonenzymatic antioxidants and their redox ratio, phycobiliproteins and phytochelatins, over the controls. The isoforms of antioxidant enzymes namely superoxide dismutase (Mn-SOD, ~150 kDa; Fe-SOD ~120 kDa), glutathione peroxidase (GSH-Px, ~120 and 140 kDa), glutathione reductase (GR, ~110 kDa) regulated differentially to Se and/or Spm supplementation. Furthermore, it has also resulted in enhanced levels of endogenous PAs (specially free and bound insoluble Put and Spm) and n-6 PUFAs (C20-3, n-6 and C20-4, n-6). This is for the first time wherein Se and Spm were found to regulate the stabilization of DNA methylation by reducing the events of cytosine demethylation in a mechanism to alleviate the Cd stress in marine alga. The present findings reveal that both Se and Spm play a crucial role in controlling the Cd induced oxidative stress in G. dura.

Plant Physiology and Biochemistry, 2011

Plant Molecular Biology Reporter, 2012

Physics of Plasmas, 2009

Rayleigh scattering of an intense laser with Gaussian temporal and radial profiles from clustered... more Rayleigh scattering of an intense laser with Gaussian temporal and radial profiles from clustered gases is examined. The laser quickly converts the clusters into plasma balls with electron cloud of each ball executing large excursions about the ion sphere. The laser also heats the electrons. As the clusters expand under hydrodynamic pressure, plasma frequency of the cluster electrons pe decreases. The temporal rate of decrease in pe is maximum on laser axis and falls off with r. As the electron density of a cluster approaches plasma resonance, pe = ͱ 3 ͑where is the frequency of the laser͒ the oscillatory electron cloud of the cluster produces resonantly enhanced Rayleigh scattering. This resonant enhancement first occurs in clusters on laser axis and afterward in farther clusters. The diffraction divergence of the laser limits the length of the cluster plasma, hence the Rayleigh scattering.

Physics and Chemistry of the Earth, Parts A/B/C, 2006

Employing USGS earthquake data for Indian region and very low frequency (VLF, 3 kHz) subsurface e... more Employing USGS earthquake data for Indian region and very low frequency (VLF, 3 kHz) subsurface electric field data obtained by using a borehole antenna at Agra in India, statistical analysis has been carried out to identify the earthquake sources responsible for VLF data. The correlation coefficient between occurrence number of VLF noise bursts and earthquakes are calculated and level of null hypothesis tested. The results show that seismic activities occurring close to the observing station and the main boundary fault located at the southern base of Himalaya are the main sources of VLF emissions recorded at the station.

physica status solidi (b), 2013

ABSTRACT We demonstrate in this work the effect of Rashba spin–orbit interaction (SOI) on multiph... more ABSTRACT We demonstrate in this work the effect of Rashba spin–orbit interaction (SOI) on multiphoton optical transitions of a quantum dot (QD) in the presence of a terahertz (THz) laser field and external static magnetic field. This combination is solved by accurate nonperturbative Floquet theory. Investigations are made for the optical response of intraband transitions between the various states of the conduction band with spin flipping. It is found that spin‐flip transitions and corresponding multiphoton transitions are strongly affected by Rashba spin orbit coupling and THz laser fields. This aspect will enhance the ongoing efforts for making ultrasensitive optospintronics devices.

Pharmaceutical Biology, 1992

... We now report on the antifertility activity of a crude ethanol extract in male albino rats. M... more ... We now report on the antifertility activity of a crude ethanol extract in male albino rats. MATERIALS AND METHODS ... Animals were fed with pelleted standard rat feed (Hindustan Lever Ltd., India), supplemented with soaked gram and wheat. Water was provided ad libilum. ...

Pediatric Neurology, 2008

Introduction: Cerebral palsy (CP) is a heterogeneous disease and is associated with various types... more Introduction: Cerebral palsy (CP) is a heterogeneous disease and is associated with various types and degrees of motor impairment. This permanent and nonprogressive disorder caused by damage to the developing brain manifests early in life. 1 Physical, occupational and constraint induced therapies are used in CP to improve the quality of life. Botulinum toxin is a treatment of choice in the clinical management of spasticity. 2 The temporary benefit of botulinum treatment can be significantly extended through activity-based rehabilitation programs. 3 We hypothesize that this treatment regimen induces plastic changes in corticospinal tracts (CST), an important part of the motor system for controlling movements.

Palliative and Supportive Care, 2010

Delirium is a clinical syndrome that is known to be under recognized by palliative care teams. A ... more Delirium is a clinical syndrome that is known to be under recognized by palliative care teams. A wide variation in reported prevalence may reflect differences in definitions and assessment methods, patient characteristics, and study design. The aim of this study was to test an intervention to improve recognition of delirium in the inpatient palliative care setting. We conducted a retrospective palliative care notes review of documented prevalence of delirium among 61 patients referred to the Specialist Palliative Care Advisory Team (SPCT). Subsequently, training in the use of the Confusion Assessment Method (CAM) was provided to the SPCT and a prospective survey of the prevalence of delirium measured by the CAM was undertaken with the next 59 patients referred. In the retrospective chart review, the term…

Otolaryngology - Head and Neck Surgery, 2004

The study goal was to determine the presentation of head and neck trauma (HNT) in hospitalized pe... more The study goal was to determine the presentation of head and neck trauma (HNT) in hospitalized pediatric subjects. Study design and setting Retrospective review of 257 subjects admitted to a level I pediatric trauma center. The male/female ratio of the subjects was 2.5:1, with a median age of 9.3 years. Also, 35.0% of subjects had associated major non-HNT. HNT anatomic sites varied with age. The leading major HNT was facial/base of skull fractures (FBSF). Motor vehicle trauma was significant in subjects older than 3 years, and bite and falls were significant in subjects younger than 3 years. FBSF increased 3.7 times (P = 0.02) for subjects older than 10 years compared with subjects younger than 3 years. The most common major HNT was FBSF, with older age at higher risk. Associated major non-HNT is high. Mechanisms of injury and sites of HNT vary with age. This information may improve prevention counseling and aid preparation for the management of pediatric HNT.