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| 2. |
- Bazov, Igor, et al.
(author)
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The endogenous opioid system in human alcoholics : molecular adaptations in brain areas involved in cognitive control of addiction
- 2013
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In: Addiction Biology. - : Wiley. - 1355-6215 .- 1369-1600. ; 18:1, s. 161-169
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Journal article (peer-reviewed)abstract
- The endogenous opioid system (EOS) plays a critical role in addictive processes. Molecular dysregulations in this system may be specific for different stages of addiction cycle and neurocircuitries involved and therefore may differentially contribute to the initiation and maintenance of addiction. Here we evaluated whether the EOS is altered in brain areas involved in cognitive control of addiction including the dorsolateral prefrontal cortex (dl-PFC), orbitofrontal cortex (OFC) and hippocampus in human alcohol-dependent subjects. Levels of EOS mRNAs were measured by quantitative reverse transcription-polymerase chain reaction (qRT-PCR), and levels of dynorphins by radioimmunoassay (RIA) in post-mortem specimens obtained from 14 alcoholics and 14 controls. Prodynorphin mRNA and dynorphins in dl-PFC, κ-opioid receptor mRNA in OFC and dynorphins in hippocampus were up-regulated in alcoholics. No significant changes in expression of proenkephalin, and µ- and δ-opioid receptors were evident; pro-opiomelanocortin mRNA levels were below the detection limit. Activation of the κ-opioid receptor by up-regulated dynorphins in alcoholics may underlie in part neurocognitive dysfunctions relevant for addiction and disrupted inhibitory control.
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| 3. |
- Hussain, Muhammad Zubair, 1971-
(author)
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Molecular Adaptations in the Endogenous Opioid System in Human and Rodent Brain
- 2013
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Doctoral thesis (other academic/artistic)abstract
- The aims of the thesis were to examine i) whether the endogenous opioid system (EOS) is lateralized in human brain areas involved in processing of emotions and pain; ii) whether EOS responses to unilateral brain injury depend on side of lesion, and iii) whether in human alcoholics, this system is involved in molecular adaptations in brain areas relevant for cognitive control of addictive behavior and habit formation.The main findings were that (1) opioid peptides but not opioid receptors and classic neurotransmitters are markedly lateralized in the anterior cingulate cortex involved in processing of positive and negative emotions and affective component of pain. The region-specific lateralization of neuronal networks expressing opioid peptides may underlie in part lateralization of higher functions in the human brain including emotions and pain. (2) Analysis of the effects of traumatic brain injury (TBI) demonstrated predominant alteration of dynorphin levels in the hippocampus ipsilateral to the injury, while injury to the right hemisphere affected dynorphin levels in the striatum and frontal cortex to a greater extent than that to the left hemisphere. Thus, trauma reveals a lateralization in the mechanisms mediating the response of dynorphin expressing neuronal networks in the brain. These networks may differentially mediate effects of left or right brain injury on lateralized brain functions. (3) In human alcoholics, the enkephalin and dynorphin systems were found to be downregulated in the caudate nucleus and / or putamen that may underlie in part changes in goal directed behavior and formation of a compulsive habit in alcoholics. In contrast to downregulation in these areas, PDYN mRNA and dynorphins in dorsolateral prefrontal cortex, k-opioid receptor mRNA in orbitofrontal cortex, and dynorphins in hippocampus were upregulated in alcoholics. Activation of the k-opioid receptor by upregulated dynorphins may underlie in part neurocognitive dysfunctions relevant for addiction and disrupted inhibitory control.We conclude that the EOS exhibits region-specific lateralization in human brain and brain-area specific lateralized response after unilateral TBI in mice; and that the EOS is involved in adaptive processes associated with specific aspects of alcohol dependence.
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| 4. |
- Hussain, Zubair Muhammad, et al.
(author)
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Lateralized Response of Dynorphin A Peptide Levels after Traumatic Brain Injury
- 2012
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In: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 0897-7151 .- 1557-9042. ; 29:9, s. 1785-1793
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Journal article (peer-reviewed)abstract
- Traumatic brain injury (TBI) induces a cascade of primary and secondary events resulting in impairment of neuronal networks that eventually determines clinical outcome. The dynorphins, endogenous opioid peptides, have been implicated in secondary injury and neurodegeneration in rodent and human brain. To gain insight into the role of dynorphins in the brain's response to trauma, we analyzed short-term (1-day) and long-term (7-day) changes in dynorphin A (Dyn A) levels in the frontal cortex, hippocampus, and striatum, induced by unilateral left-side or right-side cortical TBI in mice. The effects of TBI were significantly different from those of sham surgery (Sham), while the sham surgery also produced noticeable effects. Both sham and TBI induced short-term changes and long-term changes in all three regions. Two types of responses were generally observed. In the hippocampus, Dyn A levels were predominantly altered ipsilateral to the injury. In the striatum and frontal cortex, injury to the right (R) hemisphere affected Dyn A levels to a greater extent than that seen in the left (L) hemisphere. The R-TBI but not L-TBI produced Dyn A changes in the striatum and frontal cortex at 7 days after injury. Effects of the R-side injury were similar in the two hemispheres. In naive animals, Dyn A was symmetrically distributed between the two hemispheres. Thus, trauma may reveal a lateralization in the mechanism mediating the response of Dyn A-expressing neuronal networks in the brain. These networks may differentially mediate effects of left and right brain injury on lateralized brain functions.
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| 5. |
- Khan, Waqas Nawaz, et al.
(author)
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Performance Evaluation of Time-Reversal on Measured 60 GHz Wireless Channels
- 2013
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In: Wireless Personal Communications. - : Springer Science and Business Media LLC. - 1572-834X .- 0929-6212. ; 71:1, s. 707-717
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Journal article (peer-reviewed)abstract
- Time-reversal (TR) signal processing has the potential to focus the transmitted signal at a desired receive (Rx) location in both space and time. At lower frequency bands, TR in conjunction with array antennas at transmit (Tx) or Rx has been shown to significantly improve its focusing performance relative to the case of single antennas at both link ends. This work for the first time investigates TR processing for multi-antenna systems in the 60 GHz band. We consider both multiple-input-single-output and single-input-multiple-output (SIMO) channels measured in the 60 GHz band in a conference room environment and investigate the effect of array size and its orientation on spatial and temporal compression properties of TR. It is observed that the root mean square (RMS) delay spread can be reduced significantly by the application of TR in the 60 GHz band and that the orientation of the Rx array significantly affects TR performance for SIMO systems.
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| 6. |
- Zubair, Muhammad, et al.
(author)
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Detection of genetic and phytochemical differences between and within populations of Plantago major L. (plantain)
- 2012
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In: Scientia Horticulturae. - : Elsevier BV. - 0304-4238 .- 1879-1018. ; 136, s. 9-16
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Journal article (peer-reviewed)abstract
- Leaves of Plantago major L. (common plantain) have been used for centuries almost all over the world as a wound healing remedy, and for other medicinal purposes. Polyphenols have been proposed to be responsible for many of the medicinal properties attributed to P. major. In this study, plants from 19 subpopulations (offspring families), derived from a total of five populations of P. major collected from different parts of Sweden, were screened for genetic variation with molecular markers, and for contents of major polyphenolic compounds. In addition to plantamajoside, four novel poplyphenolic compounds were identified and quantified. RAPD analysis demonstrated considerable between-population variation and very sparse within-population and within-subpopulation variation, just as expected for inbreeding species. Differentiation among populations was associated with the geographical distances between the sampled populations. Differences between populations and subpopulations in polyphenol contents did not reflect the DNA-marker based pattern, suggesting that the expression of the studied polyphenols was affected by, e.g., epigenetic inheritance Or a very early environmental influence on the newly germinated seedlings, before potting and randomization. (c) 2012 Elsevier B.V. All rights reserved.
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| 7. |
- Zubair, Muhammad, et al.
(author)
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Effects of Plantago major L. leaf extracts on oral epithelial cells in a scratch assay
- 2012
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In: Journal of Ethnopharmacology. - : Elsevier Ireland Ltd. - 0378-8741 .- 1872-7573. ; 141:3, s. 825-830
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Journal article (peer-reviewed)abstract
- Aim of study The present study was undertaken to evaluate the effects from different leaf extracts of the traditional medicinal herb Plantago major L. (plantain) on cell proliferation and migration in vitro, as a test for potential wound healing properties. Materials and methods Water and ethanol-based extracts were prepared from Plantago major fresh and dried leaves, and tested in vitro in a scratch assay with oral epithelial cells. Results The scratch assay produced reliable results after 18 h. Most of the tested extracts increased the proliferation/migration of the oral epithelial cells compared to the negative control. A concentration of 1.0 mg/mL (on dry weight basis) appears to be optimal regardless of type of extract, and among the alternatives, 0.1 mg/mL was always better than 10 mg/mL. Ethanol-based extracts with a concentration of 10 mg/mL had very detrimental effects on cell proliferation/migration. At the other two concentrations, ethanol-based extracts had the most beneficial effect, followed by water extracts of fresh leaves, ethanol plus water extracts of dried leaves and, finally, water extracts of dried leaves. This study suggests that both the water extracts and the more polyphenol-rich ethanol-based extracts of Plantago major leaves have medicinal properties. Further research is, however, needed to determine what compounds are responsible for the wound healing effects.
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| 8. |
- Zubair, Muhammad
(author)
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Genetic and environmental effects on polyphenols in Plantago major
- 2010
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Reports (other academic/artistic)abstract
- Leaves and seeds of Plantago major (common plantain or greater plantain) have been used for centuries to treat diseases relating to skin, digestive organs and blood circulation like wounds, inflammation and hypertension. Either whole or crushed leaves have been used to treat for example burns and all kinds of wounds to enhance the healing process, and to stop bleeding. To treat superficial wounds it is sufficient to apply the juice from the leaves. Both polysaccharides and polyphenols may have a synergistic effect on wound healing and other biological activities. Polyphenols extracted from leaves and seeds of P. major have been reported to have bioactive effects especially on wound healing, and to have antiulcerogenic, anti-inflammatory, antioxidant, anticarcinogenic and antiviral activity. Three subspecies have been described of P. major, two of which have been subjected to genetic and phytochemical analysis. Plantago major subsp. major is naturalized almost throughout the world and is mainly found as an agronomic weed. There has been little work emphasizing the utilization of the bioactive compounds from P. major in modern medicine. Similarly, the effects of genetic and environmental factors on the occurrence of these bioactive compounds have not been reported. The main emphasis of the introductor y paper is to highlight some factors that may be important for the utilization of Plantago major as a medicinal herb, providing the scope for the Ph.D. study. This paper also describes the taxonomy including morphological differences between the two subspecies, distribution, biology, genetics and DNA markers used in P. major
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| 9. |
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| 10. |
- Zubair, Muhammad
(author)
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Genetic variation, biochemical contents and wound healing activity of Plantago major
- 2012
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Doctoral thesis (other academic/artistic)abstract
- Plantago major L. (greater plantain, common plantain) has been used as a wound healing remedy in different parts of the world for centuries. Different bioactive compounds have been proposed to contribute to the wound healing properties of this plant. The present study was undertaken to investigate the impact of some genetic and environmental factors on the wound healing activity of common plantain. Seeds of P. major were collected from five populations in different parts of Sweden, and were germinated and grown in a greenhouse. As expected for an inbreeding species, RAPD analyses demonstrated considerable between-population variation but very sparse within-population and within-subpopulation variation. Six major phenolic compounds were encountered in samples of P. major, four of which were identified for the first time in this thesis; PLMA 1–PLMA 4. Between-population and sub-population differences in the contents of these chemical compounds showed no correlation with RAPD-based estimates of genetic relatedness. The contents of these compounds differed greatly between different plant organs of P. major. The highest concentration of plantamajoside and PLMA 2 was found in leaves whereas the highest concentration of verbascoside was found in flower stalks and seeds. Contents were significantly higher in freeze-dried leaf samples compared to samples dried at higher temperatures. Both water and ethanol-based extracts of P. major leaves stimulated the cell proliferation and migration in an in vitro scratch assay, and also showed anti-inflammatory activity in an in vitro NF-kB assay with oral epithelial cell cultures. Similarly, these extracts stimulated wound healing activities in ex vivo tests using detached pig ears. Further breeding efforts aimed at developing P. major as a crop plant, and medicinal research aimed at elucidating and optimizing extracts with wound healing properties, are thus warranted.
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