A Kumar

Publications (21)20.68 Total impact

• Article: Polymorphisms of MTHFR and MTR genes are not related to susceptibility to childhood ALL in North India.

  M Nikbakht, K MalekZadeh, A Kumar Jha, M Askari, R K Marwaha, D Kaul, J Kaur
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  ABSTRACT: Acute lymphoblastic leukemia (ALL) is the most worldwide common type of childhood cancer. Methylenetetrahydrofolate reductase (MTHFR) and 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) participate in folate pathways and are known as critical factors for DNA integrity as well as DNA hypomethylation. The aim of this work is to investigate frequency of MTHFR (677C→T and 1298A→C) and MTR (2756A→G) polymorphisms and their interaction with respect to possible effect on risk of childhood ALL among North Indian population. A case control study from has been conducted on bone marrow and peripheral blood samples from 125 ALL patients and 100 sex-age matched healthy controls using PCR-RFLP method. No statistically significant differences were observed for different genotypes between patients and controls (p>0.05). Significant difference for the risk of ALL in individuals having genotype of MTHFR 677TT (OR=0.61, 95% CI=0.21-1.77) and MTHFR 1298CC (OR=0.56, 95% CI=0.18-1.68) was not observed. The correlation of SNP of MTR gene and risk of ALL was not observed, too. The differences in distribution of possible combined genotypes of MTHFR (677C→T, 1298A→C) and MTR (2756A→G) between ALL patients and controls were statistically insignificant.
  Experimental oncology 03/2012; 34(1):43-8.
• Article: Protective effect of montelukast against quinolinic acid/malonic acid induced neurotoxicity: possible behavioral, biochemical, mitochondrial and tumor necrosis factor-α level alterations in rats.

  H Kalonia, P Kumar, A Kumar, B Nehru
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  ABSTRACT: The present study has been designed to explore the protective effect of montelukast (leukotriene receptor antagonist) against intrastriatal quinolinic acid (QA; 300 nmol) and malonic acid (MA; 6 μmol) induced Huntington's like symptoms in rats. Quinolinic acid has been reported to induce excitotoxicity by stimulating the N-methyl-D-aspartate receptor, causing calcium overload which in turn leads to the neurodegeneration. On the other hand, MA, being a reversible inhibitor of mitochondrial enzyme complex-II, leads to energy crisis and free radical generation. Recent studies have reported the therapeutic potential of leukotriene receptor antagonists in different neurodegenerative disorders. However, their exact role is yet to be established. The present study accordingly, is an attempt to investigate the effect of montelukast against QA and MA induced behavioral, biochemical and molecular alterations in rat striatum. Oxidative stress, mitochondrial enzyme complex and tumor necrosis factor-alpha (TNF-α) were evaluated on day 21st and 14th post intrastriatal QA and MA treatment, respectively. Findings of the present study demonstrate significant alteration in the locomotor activity and motor coordination as well as oxidative burden (increased lipid peroxidation, nitrite concentration and decreased endogenous antioxidants), mitochondrial enzyme complex (I, II and IV) activities and TNF-α level, in both intrastriatal QA and MA treated animals. Further, montelukast (0.4, 0.8 mg/kg p.o.) treatment for 21 and 14 days respectively, attenuated the behavioral alterations, oxidative stress, mitochondrial dysfunction and TNF-α level in these models of Huntington's disease in a significant manner. In conclusion, the present study emphasizes the neuroprotective potential of montelukast in the therapeutic management of Huntington like symptoms.
  Neuroscience 11/2010; 171(1):284-99. · 3.38 Impact Factor
• Article: Effect of Withania somnifera on Sleep-Wake Cycle in Sleep-Disturbed Rats: Possible GABAergic Mechanism.

  A Kumar, H Kalonia
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  ABSTRACT: Sleep deprivation disrupts significantly sleep pattern and cause poor quality of sleep. The aim the present study was to explore role of Withania somniferra root extract in sleep-disturbed rats. Male wistar rats (n=5-6/group) were sleep deprived for 24 h using grid suspended over water method. Withania somniferra extract (100 mg/kg) was administered intraperitoneally (i.p.) 30 min before actual recording (EEG and EMG) recording and electrophysiological recordings are further classified as- sleep latency, slow wave sleep, paradoxical sleep, total sleep, wakefulness. One day (24 h) sleep deprivation delayed latency sleep, reduced duration of slow wave sleep, rapid eye movement sleep, total sleep time and increased total waking as compared to animals placed on saw dust (P<0.05). Pretreatment with Withania somniferra extract (100 mg/kg) and diazepam (0.5 mg/kg) significantly improved electrophysiological parameters, which was further reversed by picrotoxin (2 mg/kg) and potentiated by muscimol (0.05 mg/kg). Flumazenil (2 mg/kg) did not produce any significant effect on the sleep parameters of Withania somnifera root extract. Present study suggests the involvement of GABAergic mechanism in the sleep promoting effect of Withania somniferra in sleep-disturbed state.
  Indian Journal of Pharmaceutical Sciences 11/2008; 70(6):806-10. · 0.63 Impact Factor
• Article: Quantitative analysis of in vitro compatibility of binary and ternary mixtures of nitroimidazole and macrolides in combination with omeprazole using a calorimetric technique.

  R Chadha, D V S Jain, A Kumar
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  ABSTRACT: In the present study, in vitro interactions between nitroimidazoles, macrolides and omeprazole in binary and ternary mixtures were examined by measuring their enthalpy of solution (delta(sol)H) using a calorimetric technique. A comparison of the enthalpy of solution of the pure drugs with those of binary and ternary mixtures at pH 2 and 6 was made to indicate the magnitude of interaction between them. The delta(sol)H for all the nitroimidazoles is endothermic at pH 2 and 6 but both the macrolides show exothermic behavior, whereas the enthalpy of solution of omeprazole changes from -40.52 to 4.35 kJmol(-1) as the pH changes from 2 to 6. The results have been quantified by determining the excess enthalpy of solution for both binary and ternary systems. The small deviations from ideality for all the binary systems are attributed to various non-bonding interactions between different functional groups on both the drug molecules. The results suggest compatibility of drug pairs in their binary mixtures. However, ternary mixtures show somewhat larger interactions. The magnitude of interaction enthalpy of a ternary mixture comprising tinidazole, clarithromycin and omeprazoles which are available as a marketed kitshas been calculated to be significant, suggesting that the three drugs cannot be co-formulated.
  Pharmazie 06/2007; 62(5):327-36. · 1.01 Impact Factor
• Article: Neuroprotective effects of resveratrol against intracerebroventricular colchicine-induced cognitive impairment and oxidative stress in rats.

  A Kumar, P S Naidu, N Seghal, S S V Padi
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  ABSTRACT: Alzheimer's disease is a complex and multifactorial neurodegenerative disease. Central administration of colchicine, a microtubule-disrupting agent, causes loss of cholinergic neurons and cognitive dysfunction that is associated with excessive free radical generation. The present study was aimed at evaluating the effects of trans-resveratrol in the prevention of colchicine-induced cognitive impairment and oxidative stress in rats. Intracerebroventricular administration of colchicine (15 microg/5 microl) induced impaired cognitive functions in both the Morris water maze task and the elevated plus-maze task. Chronic treatment with resveratrol (10 and 20 mg/kg, p.o.) for a period of 25 days, beginning 4 days prior to colchicine injection, significantly improved the colchicine-induced cognitive impairment. Intracerebroventricular colchicine injection resulted in free radical generation characterized by alterations in oxidative stress markers with a significant increase in malondialdehyde (MDA) and nitrite levels and depletion of reduced glutathione (GSH) activity in the rat brains. It also showed a significant decrease in acetylcholinesterase activity. Besides improving cognitive dysfunction, chronic administration of resveratrol significantly reduced the elevated MDA and nitrite levels and restored the depleted GSH and acetylcholinesterase activity. Results of the present study indicated that trans-resveratrol has a neuroprotective role against colchicine-induced cognitive impairment and associated oxidative stress.
  Pharmacology 02/2007; 79(1):17-26. · 1.79 Impact Factor
• Article: Dielectric properties of glassy As10Te75Ge15

  K. K. Srivastava, D. R. Goyal, A. Kumar, K. N. Lakshminarayan, O. S. Panwar, I. Krishan
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  ABSTRACT: While discussing the application of Maxwell-Wagner effect to the immersion method, the accurate value of the dielectric constant at room temperature is given for the bulk memory alloy As10Te75Ge15 at 0.1 MHz. Measurements are also carried out at various temperatures and frequencies and the dielectric constant of the material shows a significant dependence on frequency and temperature. The results are discussed in terms of a molecular relaxation mechanism.Zusammen mit der Diskussion der Anwendung des Maxwell-Wagner-Effekts auf die Immersionsmethode wird ein genauer Wert der dielektrischen Konstante bei Zimmertemperatur für die Volumenspeicherlegierungen As10Te75Ge15 bei 0,1 MHz mitgeteilt. Messungen werden auch bei verschiedenen Temperaturen und Frequenzen durchgeführt, wobei die Dielektrizitätskonstante des Materials eine signifikante Abhängigkeit von der Frequenz und Temperatur zeigt. Die Ergebnisse werden mit einem molekularen Relaxationsmechanismus diskutiert.
  physica status solidi (a) 02/2006; 41(1):323 - 329. · 1.21 Impact Factor
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  Available from: sma.org.sg

  Article: Prescription monitoring of anti-hypertensive drug utilisation at the Panjab University Health Centre in India.

  H Tiwari, A Kumar, S K Kulkarni
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  ABSTRACT: The present pilot study was conducted in order to establish the drug-prescribing trend of anti-hypertensive agents at the Panjab University Health Centre in India. A pilot study of six-month duration was conducted at the Panjab University Health Centre. The information was collected from the patients attending the outpatient department through a random sample method. World Health Organisation-based prescription-auditing proforma was used for data collection. This study revealed that most of the male patients were on monotherapy (60 percent). In the monotherapy category, four classes of drugs were used. These were calcium channel blockers (48.1 percent), beta-blockers (46.2 percent), ACE inhibitors (3.9 percent) and diuretics (1.9 percent). Among monotherapy drugs, calcium channel blockers were prescribed most whereas diuretics were least used. Among those who were treated with drug combinations, 92.1% received two drugs and 7.9 percent received three drugs. In combination therapy, a two-drug combination consisting of beta-blockers and calcium channel blockers was given to the majority of the patients. Overall, 57.8 percent patients were treated with a single anti-hypertensive drug and 42.2 percent were treated with anti-hypertensive drug combinations. The present study represents the current prescribing trend for anti-hypertensive agents and it highlights certain shortcomings in the existing prescribing practice. There is a considerable scope for improvement, particularly the under-utilisation of diuretics in the present prescribing pattern of anti-hypertensive drugs.
  Singapore medical journal 04/2004; 45(3):117-20. · 0.73 Impact Factor
• Article: Calorimetric studies of diclofenac sodium in aqueous solution of cyclodextrin and water-ethanol mixtures.

  R Chadha, N Kashid, A Kumar, D V S Jain
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  ABSTRACT: The technique of solution calorimetry has been employed to study the interaction between diclofenac sodium and beta-cyclodextrin by determining the enthalpies of solution of the drug in water and in aqueous beta-cyclodextrin solution. Thermodynamic parameters characterizing the binding process such as enthalpy deltaH0, equilibrium constant K, free energy deltaG0 and entropy deltaS0 have been calculated to be 12.00 kJ mol(-1), 1670 dm3 mol(-1), -19.03kJ mol(-1) and 22.98 J K(-1) mol(-1), respectively. Enthalpies of solution of diclofenac sodium have also been determined in water-ethanol mixtures.
  Journal of Pharmacy and Pharmacology 05/2002; 54(4):481-6. · 2.17 Impact Factor
• Article: Analgesic and anti-inflammatory effects of phosphodiesterase inhibitors.

  A Kumar, N K Jain, S K Kulkarni
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  ABSTRACT: The aim of the present study was to investigate the role of phosphodiesterase (PDE) enzyme inhibitors namely rolipram and theophylline in pain and inflammation in experimental animals. Rolipram, a selective PDE IV inhibitor and theophylline a nonspecific PDE inhibitor exerted dose dependent analgesic and anti-inflammatory effect against acetic acid-induced writhing in mice and carrageenan-induced paw edema in rats, respectively. Nimesulide (1, 2 mg/kg) produced significant anti-inflammatory effect. Further, nimesulide (0.5 mg/kg) potentiated analgesic effect of rolipram but it failed to modulate the anti-inflammatory effect of PDE inhibitors. Present study suggests that PDE enzymes might be playing a role in nociceptive and inflammatory responses in animals.
  Indian journal of experimental biology 02/2000; 38(1):26-30. · 1.29 Impact Factor
• Article: Dielectric behaviour of hot pressed AlN ceramic exposed to organic acid vapours

  K. K. Srivastava, A. Kumar
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  ABSTRACT: The effect of exposure to HCOOH and CH3COOH vapours on the dielectric behaviour of hot pressed AlN ceramic having different volume percentages of porosity is studied. Dielectric constant and dissipation factor both increase after exposure to acid vapours at humidity levels greater than atmospheric. The results indicate that the porosity plays an important role in the change of dielectric parameters on exposure to acid vapours. The exposure effects are found to be completely reversible as, after annealing, the exposed samples show behaviour similar to that of unexposed samples. The results are explained in terms of ionic conduction due to dissociation of these vapours in the presence of moisture.MST/1137
  Materials Science and Technology 01/1990; 6(2):137-140. · 0.77 Impact Factor
• Article: Dielectric behaviour of hot pressed AlN ceramic exposed to inorganic acid vapours

  K. K. Srivastava, M. Zulfequar, A. Kumar
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  ABSTRACT: Dielectric behaviour of hot pressed AIN ceramic is studied before and after exposing the samples to inorganic acid (HCl and HNO3) vapours with a specific aim to study the effect of these vapours on the dielectric constant () and dissipation factor (tan ). Four samples having different volume percentage of porosity (0.2 to 15%) are selected for this study. Dielectric dispersion increases after exposing the samples to the above acid vapours. Tan also increases quite appreciably; the increase being more at higher porosity. Recovery studies show that the exposure effect is reversible. The exposure time dependence of and tan indicates that these parameters show a maxima at a particular exposure time. However, no such maxima is observed in the gravimetric measurements. The increase in dielectric parameters after exposure to acid vapours is explained in terms of the ionic conduction due to the dissociation of these vapours in the presence of moisture. The porosity dependence of this effect is discussed in terms of closed and open porosity reported by other workers.
  Journal of Materials Science 01/1990; 25(6):2861-2865. · 2.02 Impact Factor
• Article: Effect of SrO additive on the electrical and dielectric behaviour of hot-pressed AlN ceramic

  K. K. Srivastava, M. Zulfequar, A. Kumar
  Journal of Materials Science Letters 04/1989; 8(5):543-547.
• Article: Vitamin K deficiency related bleeding manifestations in older neonates and infants.

  R K Marwaha, A Kumar, G Garewal, N Marwaha, B N Walia
  Indian pediatrics 05/1987; 24(4):307-11. · 1.05 Impact Factor
• Article: Infantile Gaucher's disease.

  A Kumar, R K Marwaha, S K Yachha, R Sarode, G Garewal
  Indian pediatrics 05/1987; 24(4):344-6. · 1.05 Impact Factor
• Article: Pancytopenia and leukemoid reactions in tuberculosis.

  J Chandra, R K Marwaha, N Marwaha, A Kumar, D Mothanty
  The Indian Journal of Pediatrics 04/1986; 53(5):665-7. · 0.52 Impact Factor
• Article: Possible role of trazodone and imipramine in sleep deprivation-induced anxiety-like behavior and oxidative damage in mice.

  A Kumar, R Garg
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  ABSTRACT: Sleep is one of the key regulators for maintaining physical, mental and emotional health. Nonrefreshing sleep and depression are common problems nowadays. The present study was designed to explore the protective effects of trazodone and imipramine on 72-h sleep deprivation-induced anxiety-like behavior and oxidative damage in mice. Albino mice were sleep-deprived for a period of 72 h using the grid suspended over water method. Animals were divided into different groups, each consisting of six animals. Trazodone (5 and 10 mg/kg i.p.) and imipramine (10 and 20 mg/kg i.p.) were administered for 5 days starting 2 days before 72-h sleep deprivation. Various behavioral tests (elevated plus maze, zero maze, mirror chamber for anxiety and actophotometer), followed by oxidative parameter tests (malondialdehyde, glutathione, catalase, nitrite and protein), were assessed in sleep-deprived animals. Treatment with trazodone and imipramine significantly improved locomotor activity and exerted anxiolytic-like effects in all paradigm tasks (mirror chamber, elevated plus maze, zero maze) as compared to untreated 72-h sleep-deprived animals (P < 0.05). Biochemically, both trazodone and imipramine significantly restored depleted reduced glutathione (GSH) levels and catalase activity and attenuated raised lipid peroxidation and nitrite concentrations as compared to untreated sleep-deprived animals. The results of the present study suggest a protective effect for trazodone and imipramine on sleep deprivation-induced anxiety-like behavior and oxidative damage in mice.
  Methods and Findings in Experimental and Clinical Pharmacology 31(6):383-7. · 0.93 Impact Factor
• Article: Disseminated Burkitt's lymphoma: a case report.

  B R Thapa, R K Marwaha, A Kumar, A Rajwanshi, S Mehta
  Indian Journal of Cancer 21(4):126-9.
• Article: Possible neuroprotective mechanisms of curcumin in attenuating 3-nitropropionic acid-induced neurotoxicity.

  P Kumar, S S V Padi, P S Naidu, A Kumar
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  ABSTRACT: 3-Nitropropionic acid (3-NP) is a well known fungic toxin causing neurotoxicity. Systemic administration of 3-NP causes motor and cognitive deficits that are associated with excessive free radical generation. Recently, curcumin has been implicated as a neuroprotectant in the treatment of various neurological disorders. The present study was designed to investigate the effects of curcumin in 3-NP-induced cognitive impairment and oxidative stress in rats. Curcumin, a potent antioxidant of dietary polyphenol, containing a standardized extract of Curcuma longa root (Zingiberaceae), has been reported to possess free radical scavenging, iron chelating and antiinflammatory activities. Intraperitoneal administration of 3-NP (20 mg/kg for 4 days) showed loss in body weight, declined motor function, poor retention of memory and changes in oxidative stress (lipid peroxidation, reduced glutathione and nitrite level) parameters in brain. Chronic treatment with curcumin (10, 20 and 50 mg/kg, p.o.) once daily for a period of 8 days beginning 4 days prior to 3-NP administration dose-dependently improved the 3-NP-induced motor and cognitive impairment. Biochemical analysis revealed that curcumin administration significantly attenuated 3-NP-induced oxidative stress (lipid peroxidation estimation, reduced glutathione and nitrite activity) in the brains of rats. It also significantly restored the decreased succinate dehydrogenase activity. The results of the present study clearly indicate that curcumin by its antioxidant activity showed neuroprotection against 3-NP-induced behavioral and biochemical alteration.
  Methods and Findings in Experimental and Clinical Pharmacology 29(1):19-25. · 0.93 Impact Factor
• Article: Angular momentum induced deformation of 2755Co at 84 MeV excitation

  D.K. Agnihotri, A. Kumar, K.C. Jain, K.P. Singh, D. Kabiraj, D.K. Avasthi, I.M. Govil
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  ABSTRACT: The α-particle spectra at different laboratory angles were measured from the fusion reaction 27Al+28Si at Elab=140.0 MeV. These spectra deviate at both higher and lower energies from theoretical calculations using RLDM moments of inertia. In order to explain the experimental spectra changes were required in the emission barriers and moments of inertia corresponding to large nuclear deformations.
  Physics Letters B.
• Article: Differential cross-section measurements for elastic scattering of 22.1 keV photons by elements with 6⩽Z⩽81

  A. Kumar, J.S. Shahi, D. Mehta, N. Singh
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  ABSTRACT: Elastic scattering differential cross-sections for the 22.1 keV photons (Ag–Kα X-rays) have been measured for fifteen elements with 6⩽Z⩽81 at an angle of 133°. The measurements were performed using the radioisotope as photon source and a Si(Li) detector. The measurements include the Ag element, where the elastic scattered photon yield was deduced from the observed 22.1 keV peak after subtracting the contribution of the fluorescent Kα X-rays produced by the 88.03 keV γ-ray and internal bremsstrahlung photons from the radioisotope. The measured elastic scattering cross-sections have been compared with those evaluated using the form-factor and the second-order S-matrix formalisms.
  Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms 194(2):105-111. · 1.21 Impact Factor