| 1. |
- Sharma, Hari Shanker, et al.
(författare)
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Antibodies to Dynorphin A (1-17) Attenuate Closed Head Injury Induced Blood-Brain Barrier Disruption, Brain Edema Formation and Brain Pathology in the Rat
- 2010
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Ingår i: Brain Edema XIV. - Vienna : Springer. - 9783211987582 - 9783211988114 ; , s. 301-306
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Konferensbidrag (refereegranskat)abstract
- The potential neuroprotective efficacy of dynorphin A antiserum on BBB dysfunction, edema formation and brain pathology was examined in a closed head injury (CHI) model in the rat. The CHI was produced by an impact of 0.224 N on the right parietal bone under anesthesia by dropping a weight of 114.6 g on the skull from a height of 20 cm through a guide tube. This concussive brain injury resulted in profound BBB disruption as evidenced by leakage of Evans blue and radioiodine in the brain. Edema formation and swelling at 5 h were most pronounced in the contralateral cerebral hemisphere. Pretreatment with dynorphin A antiserum (1:20, monoclonal) infused into the left lateral cerebral ventricle (30 mu L in PBS) either 30 min before or 30 min after CHI significantly attenuated BBB dysfunction, brain edema formation, volume swelling and brain pathology. However, no reduction in brain edema, BBB permeability or improved brain pathology was seen when the antiserum was given 60 min post-CHI. These observations are the first to suggest that antiserum to dynorphin when administered into the CSF during early phase of CHI is neuroprotective. Our work further indicates that dynorphin is actively involved in the cellular and molecular mechanisms of edema formation and BBB breakdown in CHI.
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| 2. |
- Sharma, Hari Shanker, et al.
(författare)
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Nanowired-Drug Delivery Enhances Neuroprotective Efficacy of Compounds and Reduces Spinal Cord Edema Formation and Improves Functional Outcome Following Spinal Cord Injury in the Rat
- 2010
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Ingår i: Brain Edema XIV. - Vienna : Springer. - 9783211987582 - 9783211988114 ; , s. 343-350
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Konferensbidrag (refereegranskat)abstract
- The possibility that drugs attached to nanowires enhance their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three Acure compounds AP-173, AP-713 and AP-364 were tagged with TiO2-based nanowires (50-60 nm) and applied over the traumatized cord either 5 or 60 min after SCI in rats produced by a longitudinal incision into the right dorsal horn of the T10-11 segments under equithesin anaesthesia. Normal compounds were used for comparison. After 5 h SCI, behavioral outcome, blood-spinal cord barrier (BSCB) permeability, edema formation and cell injury were examined. Topical application of nanowired compound AP-713 (10 mu g in 20 mu L) when applied either 5 or 60 min after injury markedly attenuated behavioral dysfunction at 2-3 h after SCI and reduces BSCB disruption, edema formation and cord pathology at 5 h compared to other compounds. Whereas normal compounds applied at 5 min after injury (but not after 60 min) had some significant but less beneficial effects compared to their nanowired combinations. On the other hand, nanowires alone did not influence spinal cord pathology or motor function after SCI. Taken together, our results indicate that the nanowired-drug-delivery enhances the neuroprotective efficacy of drugs in SCI and reduces functional outcome compared to normal compounds even applied at a later stage following trauma, not reported earlier.
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| 5. |
- Sharma, Aruna, et al.
(författare)
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Size- and Age-Dependent Neurotoxicity of Engineered Metal Nanoparticles in Rats
- 2013
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Ingår i: Molecular Neurobiology. - : Springer Science and Business Media LLC. - 0893-7648 .- 1559-1182. ; 48:2, s. 386-396
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Tidskriftsartikel (refereegranskat)abstract
- Earlier we showed that chronic administration of engineered nanoparticles (NPs) from metals, e.g., Cu, Ag, or Al (50-60 nm, 50 mg/kg, i.p. daily for 1 week) alter blood-brain barrier (BBB) disruption and induce brain pathology in adult rats (age 18 to 22 weeks). However, effects of size-dependent neurotoxicity of NPs in vivo are still largely unknown. In present investigation, we examined the effects of different size ranges of the above-engineered NPs on brain pathology in rats. Furthermore, the fact that age is also an important factor in brain pathology was also investigated in our rat model. Our results showed that small-sized NPs induced the most pronounced BBB breakdown (EBA +480 to 680 %; radioiodine +850 to 1025 %), brain edema formation (+4 to 6 %) and neuronal injuries (+30 to 40 %), glial fibrillary acidic protein upregulation (+40 to 56 % increase), and myelin vesiculation (+30 to 35 % damage) in young animals as compared to controls. Interestingly, the oldest animals (30 to 35 weeks of age) also showed massive brain pathology as compared to young adults (18 to 20 weeks old). The Ag and Cu exhibited greater brain damage compared with Al NPs in all age groups regardless of their size. This suggests that apart from the size, the composition of NPs is also important in neurotoxicity. The very young and elderly age groups exhibited greater neurotoxicity to NPs suggests that children and elderly are more vulnerable to NPs-induced brain damage. The NPs-induced brain damage correlated well with the upregulation of neuronal nitric oxide synthase activity in the brain indicating that NPs-induced neurotoxicity may be mediated via increased production of nitric oxide, not reported earlier.
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| 7. |
- Sharma, Hari S., et al.
(författare)
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Cerebrolysin Attenuates Heat Shock Protein (HSP 72 KD) Expression in the Rat Spinal Cord Following Morphine Dependence and Withdrawal : Possible New Therapy for Pain Management
- 2011
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Ingår i: Current Neuropharmacology. - 1570-159X .- 1875-6190. ; 9:1, s. 223-235
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Tidskriftsartikel (refereegranskat)abstract
- The possibility that pain perception and processing in the CNS results in cellular stress and may influence heat shock protein (HSP) expression was examined in a rat model of morphine dependence and withdrawal. Since activation of pain pathways result in exhaustion of growth factors, we examined the influence of cerebrolysin, a mixture of potent growth factors (BDNF, GDNF, NGF, CNTF etc,) on morphine induced HSP expression. Rats were administered morphine (10 mg/kg, s.c. /day) for 12 days and the spontaneous withdrawal symptoms were developed by cessation of the drug administration on day 13(th) that were prominent on day 14(th) and continued up to day 15(th) (24 to 72 h periods). In a separate group of rats, cerebrolysin was infused intravenously (5 ml/kg) once daily from day one until day 15(th). In these animals, morphine dependence and withdrawal along with HSP immunoreactivity was examined using standard protocol. In untreated group mild HSP immunoreaction was observed during morphine tolerance, whereas massive upregulation of HSP was seen in CNS during withdrawal phase that correlated well with the withdrawal symptoms and neuronal damage. Pretreatment with cerebrolysin did not affect morphine tolerance but reduced the HSP expression during this phase. Furthermore, cerebrolysin reduced the withdrawal symptoms on day 14(th) to 15(th). Taken together these observations suggest that cellular stress plays an important role in morphine induced pain pathology and exogenous supplement of growth factors, i.e. cerebrolysin attenuates HSP expression in the CNS and induce neuroprotection. This indicates a new therapeutic role of cerebrolysin in the pathophysiology of drugs of abuse, not reported earlier.
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| 8. |
- Sharma, Hari S., et al.
(författare)
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Exacerbation of Brain Pathology After Partial Restraint in Hypertensive Rats Following SiO2 Nanoparticles Exposure at High Ambient Temperature
- 2013
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Ingår i: Molecular Neurobiology. - : Springer Science and Business Media LLC. - 0893-7648 .- 1559-1182. ; 48:2, s. 368-379
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Forskningsöversikt (refereegranskat)abstract
- This investigation examines the possibility that exposure to silica dust of hypertensive individuals may exacerbate brain pathology and sensory motor dysfunction at high environmental temperature. Hypertension was produced in rats (200-250 g) by two-kidney one clip (2K1C) method, and in these animals, SiO2 nanoparticles (NPs; 50 to 60 nm) were administered at 50 mg/kg, i.p. daily for 1 week. On the 8th day, these rats were subjected to partial restraint in a Perspex box for 4 h either at room temperature (21 A degrees C) or at 33 A degrees C in a biological oxygen demand incubator (wind velocity, 2.6 cm/s; relative humidity, 65 to 67 %). In these animals, behavioral functions, blood-brain barrier (BBB) permeability to Evans blue albumin (EBA) and radioiodine (([131]-)Iodine), brain water content and neuronal injuries were determined. Hypertensive rats subjected to 4 h restraint at room temperature did not exhibit BBB dysfunction, brain edema, neural injury, or alterations in rotarod or inclined plane angle performances. However, when these hypertensive rats were subjected to restraint at 33 A degrees C, breakdown of the cortical BBB (EBA, +38 %; radioiodine, +56 %), brain water (+0.88 %), neuronal damages (+18 %), and behavioral impairment were exacerbated. Interestingly, SiO2 exposure to these rats further exacerbated BBB breakdown (EBA, 280 %; radioiodine, 350 %), brain edema (4 %), and neural injury (30 %) after identical restraint depending on the ambient temperature. SiO2 treatment also induced brain pathology and alteration in behavioral functions in normotensive rats after restraint at high temperature. These observations clearly show that hypertension significantly enhances restraint-induced brain pathology, and behavioral anomalies particularly at high ambient temperature and SiO2 intoxication further exacerbated these brain pathologies and cognitive dysfunctions.
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