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Search Results: 1 - 10 of 23699 matches for " Paul Bobrowski "
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The chrondoprotective actions of a natural product are associated with the activation of IGF-1 production by human chondrocytes despite the presence of IL-1β
Mark JS Miller, Salahuddin Ahmed, Paul Bobrowski, Tariq M Haqqi
BMC Complementary and Alternative Medicine , 2006, DOI: 10.1186/1472-6882-6-13
Abstract: Human cartilage samples were procured from surgical specimens with consent, and were evaluated either as explants or as primary chondrocytes prepared after enzymatic digestion of cartilage matrix. Assessments included IGF-1 gene expression, IGF-1 production (ELISA), cartilage matrix degradation and nitric oxide (NO) production, under basal conditions and in the presence of IL-1β.RNI 249 enhanced basal IGF-1 mRNA levels in human chondrocytes by 2.7 fold, an effect that was further enhanced to 3.8 fold by co-administration with vincaria. Enhanced basal IGF-1 production by RNI 249 alone and together with vincaria, was confirmed in both explants and in primary chondrocytes (P <0.05). As expected, IL-1β exposure completely silenced IGF-1 production by chondrocytes. However, in the presence of IL-1β both RNI 249 and vincaria protected IGF-1 production in an additive manner (P <0.01) with the combination restoring chondrocyte IGF-1 production to normal levels. Cartilage NO production was dramatically enhanced by IL-1β. Both vincaria and RNI 249 partially attenuated NO production in an additive manner (p < 0.05). IL-1β – induced degradation of cartilage matrix was quantified as glycosaminoglycan release. Individually RNI 249 or vincaria, prevented this catabolic action of IL-1β.The identification of agents that activate the autocrine production of IGF-1 in cartilage, even in the face of suppressive pro-inflammatory, catabolic cytokines like IL-1β, represents a novel therapeutic approach to cartilage biology. Chondroprotection associated with prevention of the catabolic events and the potential for sustained anabolic activity with this natural product suggests that it holds significant promise in the treatment of debilitating joint diseases.Osteoarthritis is a painful and debilitating joint condition that affects hundreds of millions worldwide [1,2]. Despite the prevalence of the disease the current therapeutic options have significant limitations. The popular non-steroidal
Dietary antioxidants protect gut epithelial cells from oxidant-induced apoptosis
Mark JS Miller, Fausto M Angeles, Brian K Reuter, Paul Bobrowski, Manuel Sandoval
BMC Complementary and Alternative Medicine , 2001, DOI: 10.1186/1472-6882-1-11
Abstract: Cultured human gastric epithelial cells (AGS) or murine small intestinal epithelial cells (IEC-18) were exposed to oxidants – DPPH (3 μM), H2O2 (50 μM), peroxynitrite (300 μM) – followed by incubation for 24 hours, with antioxidants (10 μg/ml) administered as a 1 hour pretreatment. Cell number (MTT assay) and death via apoptosis or necrosis (ELISA, LDH release) was determined. The direct interactions between antioxidants and DPPH (100 μM) or H2O2 (50 μM) were evaluated by spectroscopy.The decoctions did not interact with H2O2, but quenched DPPH although less effectively than vitamin C. In contrast, vitamin C was significantly less effective in protecting human gastric epithelial cells (AGS) from apoptosis induced by DPPH, peroxynitrite and H2O2 (P < 0.001). Green tea and cat's claw were equally protective against peroxynitrite and H2O2, but green tea was more effective than cat's claw in reducing DPPH-induced apoptosis (P < 0.01). Necrotic cell death was marginally evident at these low concentrations of peroxynitrite and H2O2, and was attenuated both by cat's claw and green tea (P < 0.01). In IEC-18 cells, all antioxidants were equally effective as anti-apoptotic agents.These results indicate that dietary antioxidants can limit epithelial cell death in response to oxidant stress. In the case of green tea and cat's claw, the cytoprotective response exceed their inherent ability to interact with the injurious oxidant, suggestive of actions on intracellular pathways regulating cell death.Epithelial apoptosis in the gastro-intestinal tract is normally restricted to superficial cells but in pathological states of inflammation or infection, apoptotic cell death can be far more expansive. Under these conditions apoptosis may result from the production of cytokines [1], cell activation [2-4], infective agents [5] and adverse responses to pharmaceuticals [6,7]. Depending on the agonist or eliciting milieu, apoptotic cell death is accompanied by the activation of various cell
Chondroprotective effects of a proanthocyanidin rich Amazonian genonutrient reflects direct inhibition of matrix metalloproteinases and upregulation of IGF-1 production by human chondrocytes
Mark JS Miller, Paul Bobrowski, Meenakshi Shukla, Kalpana Gupta, Tariq M Haqqi
Journal of Inflammation , 2007, DOI: 10.1186/1476-9255-4-16
Abstract: Acute oral safety and toxicity was tested in rats according under OECD protocol number 420. The profile of proanthocyanidin oligomers was determined by HPLC and progrado's antioxidant activity quantified by the ORAC, NORAC and HORAC assays. Human cartilage explants, obtained from surgical specimens, were used to assess chondroproteciton with activity related to direct inhibitory effects on human matrix metalloproteinase (MMP, gelatinolytic) activity using synovial fluid and chondrocytes activated with IL-1β (10 ng/ml). Additionally, progrado (2–10 μg/ml) was tested for its ability to maintain optimal IGF-1 transcription and translation in cartilage explants and cultured chondrocytes.Both progrado and zangrado at doses up to 2000 mg/kg (po) displayed no evidence of toxicity. Oligomeric proanthocyanidin content was high for both progrado (158 mg/kg) and zangrado (124 mg/kg), with zangrado almost entirely composed of short oligomers (<6 mer), whereas the majority of oligomers in progrado exceeded 10 mers. Progrado was a remarkably potent antioxidant in the standardized tests ORAC, NORAC and HORAC. Progrado was exceptionally effective in reducing both basal and IL-1β induced glycosaminoglycan release from human cartilage explants at concentrations that also directly blocked the gelatinolytic activity of MMP-2 and MMP-9. Progrado prevented IL-1β induced suppression of IGF-1 production from human cartilage explants as well as stimulating basal IGF-1 production (P < 0.05). Comparable changes in IGF-1 gene expression were noted in cultured human chondrocytes.Progrado has a promising safety profile, significant chondroprotective and antioxidant actions, directly inhibits MMP activity and promotes the production of the cartilage repair factor, IGF-1. This suggests that progrado may offer therapeutic benefits in joint health, wound healing and inflammation.There is growing interest in natural products as agents to manage health, particularly from a preventative perspective. On
Charm mixing in the Standard Model: the inclusive approach
Bobrowski, Markus
High Energy Physics - Phenomenology , 2013,
Abstract: The talk reviews the status of Standard Model predictions for lifetimes and mixing rates of charmed mesons. I discuss sources of SU(3) breaking in the hadron state affecting the Delta C = 2 Hamiltonian and argue that they are the dominant effect generating a D0 decay width splitting.
Effective Governance, Female Educational Attainment, Leadership and Healthcare Outcomes  [PDF]
Tannista Banerjee, Paula Bobrowski, Barry Friedman
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.75082
Abstract: Positive healthcare outcomes are paramount for national competiveness, as a nation’s population is among its most valuable assets. This study examines the relationship between national political stability and control of corruption, female educational achievements and national health outcomes. Results show that increases in a nation’s political stability and control of corruption affect female educational achievement positively. We also found that improved female educational level is associated with their presence in top firm and parliament positions. Further analysis showed that greater female representation in parliament increases national health standards.
Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006–2009
N. Bobrowski,G. Giuffrida
Solid Earth (SE) & Discussions (SED) , 2012, DOI: 10.5194/se-3-433-2012
Abstract: Over a 3-yr period, from 2006 to 2009, frequent scattered sunlight DOAS measurements were conducted at Mt. Etna at a distance of around 6 km downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna. Here, results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO / SO2) ratio, and its variability in relation to volcanic processes. That the halogen/sulphur ratio can serve as a precursor or indicator for the onset of eruptive activity was already proposed by earlier works (e.g. Noguchi and Kamiya 1963; Menyailov, 1975; Pennisi and Cloarec, 1998; Aiuppa et al., 2002). However, there is still a limited understanding today because of the complexity with which halogens are released, depending on magma composition and degassing conditions. Our understanding of these processes is far from complete, for example of the rate and mechanism of bubble nucleation, growth and ascent in silicate melts (Carroll and Holloway, 1994), the halogen vapour-melt partitioning and the volatile diffusivity in the melt (Aiuppa et al., 2009). With this study we aim to add one more piece to the puzzle of what halogen/sulphur ratios might tell about volcanic activities. Our data set shows an increase of the BrO / SO2 ratio several weeks prior to an eruption, followed by a decline before and during the initial phase of eruptive activities. Towards the end of activity or shortly thereafter, the ratio increases to baseline values again and remains more or less constant during quiet phases. To explain the observed evolution of the BrO / SO2 ratio, a first empirical model is proposed. This model suggests that bromine, unlike chlorine and fluorine, is less soluble in the magmatic melt than sulphur. By using the DOAS method to determine SO2, we actually observe most of the emitted sulphur of Mt.~Etna. Regarding bromine, however, we are aware that by determining only the bromine monoxide (BrO) radical we might just observe a small or even a variable fraction of the total emitted bromine, which is most probable originally in the form of HBr. Therefore, we present first studies to justify the assumption that, despite the disadvantage just mentioned, the BrO / SO2 ratio can nevertheless serve as a new parameter to indicate the state of a volcano, when measurements are conducted under certain, but rather convenient, conditions.
Bromine monoxide/sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006–2009
N. Bobrowski,G. Giuffrida
Solid Earth Discussions , 2012, DOI: 10.5194/sed-4-475-2012
Abstract: Over a three year period, from 2006 to 2009, frequent scattered sun light DOAS measurements were conducted at Mt. Etna in a distance of around six kilometres downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna. Results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO/SO2) ratio, and its variability in relation to volcanic processes. That the halogen/sulphur ratio can serve as a precursor or indicator for the onset of eruptive activity was already proposed by earlier works (e.g. Noguchi and Kamiya, 1963; Menyailov, 1975; Pennisi and Cloarec, 1998; Aiuppa, 2002). However, there is still a limited understanding today because of the complexity with which halogens are released, depending on magma composition and degassing conditions. Our understanding of these processes is far from complete, for example of the rate and mechanism of bubble nucleation, growth and ascent in silicate melts (Carroll and Holloway, 1994), the halogen vapour-melt partitioning and the volatile diffusivity in the melt (Aiuppa et al., 2009). With this study we aim to add one more piece to the puzzle of what halogen/sulphur ratios might tell about volcanic activities. Our data set shows an increase of the BrO/SO2 ratio several weeks prior to an eruption, followed by a decline before and during the initial phase of eruptive activities. Towards the end of activity or short afterwards, the ratio increases to baseline values again and remains more or less constant during quiet phases. To explain the observed evolution of the BrO/SO2 ratio, a first empirical model is proposed. This model suggests that bromine, unlike chlorine and fluorine, is less soluble in the magmatic melt than sulphur. By using the DOAS method to determine SO2, we actually observe most of the emitted sulphur of Mt. Etna. Regarding bromine however, we are aware that by determining only the bromine monoxide (BrO) radical we might just observe a small or even a variable fraction of the total emitted bromine. Therefore we present first studies to justify the assumption that despite the disadvantage just mentioned, the BrO/SO2 ratio can nevertheless serve as a new parameter to indicate the state of a volcano, when measurements are conducted under certain, but rather convenient conditions.
Assessment of harmfulness of green sand with additions of dust from dry dedusting
M. Holtzer,A. Bobrowski
Archives of Foundry Engineering , 2010,
Abstract: Recently, in the literature about the problems cause to the environment by foundry industry, attention has been paid to the presence and harmful effect of aromatic hydrocarbons: benzene, toluene, ethylbenzene and isomers of xylenes (BTEX) and polycyclic aromatic hydrocarbons (PAHs). The growing interest in these pollutants of the environment is a result of their biological activity; some of them are characterized by mutagenic and carcinogenic action. In foundries these hydrocarbons are emitted during the contact between mould or core sands and liquid metal.This article discusses the results of the studies made on the elution rate of some harmful compounds include polycyclic aromatic hydrocarbons (PAHs) (Table 3 and 4) from waste mould sand with bentonite and coal dust M1 (mixture Kormix 75) and this one with addition of dust from dry dedusting of sand M2 preparing station (partial replacement of bentonite) and emission of BTEX gases from this moulds poured with molten cast iron. From the results given in these tables it follows that both mould sands are characterized by low values of the concentration of investigation substances and haven’t negative influence for environment during casting or management in other means. Tests were done according to the methodology developed at Faculty of Foundry Engineering University of Science and Technology in Cracow.
Assessment of environmental influence of bentonite and lustrous carbon carrier - in an aspect of gases emission
A. Bobrowski,M. Holtzer
Archives of Foundry Engineering , 2009,
Abstract: The emission results of the selected gases from a bentonite-carbon mixture and from dusts originated from dry de-dusting of thegreen sand processing plant (at high temperatures) are presented in the paper. In order to check and compare samples of dusts andbentonite-carbon mixtures in respect of emission of gases the Evolved Gas Analysis (EGA) was performed by means of the massspectrometry method. This method allows to determine emission conditions of the selected chemical compounds.
Magnesium melt protection by covering gas
M. Holtzer,A. Bobrowski
Archives of Foundry Engineering , 2008,
Abstract: Thc protcclion of liquid light metals Cmm oxidation is a major issue in recycling and mclting proccsscs in rhc light mctal industry. Thcprorcction of liquid magncsirrm surfacc was carried out by using salts. alloying clemcnts, incrt gascs or rcactivc gas mixture. Snlt bnscdprorcction is still ~hcm ost widely uscd technology in the recycling of magnesium, but gases arc more frcqucntly uscd in magnesiumc;lszing industry. Protcczing thc mottcn mctal undcr a blanket of an inert gas such as argon or helium is dangerous. bccausc no protcctivctaycr is hrrnorl on thc mctr surface and mctal is frcc to cvaporatc, resulting in safcty hazards when furnace ambicncc is cxposcd to air ducto a violcnt rcaction. Thc disadvantagcs of t hcse methods have been partially ovcrcomc by using reactive gas systcrn, in which n chcmicnlrcaction hctwccn a gas and thc moltcn mctal produces a fhin protective film on the surface of the melt. Rcaclive gascs likc SFI, or SOz donot mccr cnvironmcnral standards due to their cxtrcrnely high global warming ptentiat or toxicity. Thcreforc thc altcrnativc covcringgascs ror magncsium mclrbng arc ol big intcrcst. Gas mixturcs containing HE%-1 34a, Novec 6 12. BF3 (Magshictd systcrn) and solid C02have hccn succcssfi~lyl ~cstcdin I he world.
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