Ultrasonic Homogenizer - Published Papers
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| Article No. | Title |
| UH1041 | TNF-a Signals Apoptosis through a Bid-Dependent Conformational Change in Bax that Is Inhibited by E1B 19K |
| DENISE PEREZAND EILEEN WHITE | |
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The adenovirus E1B 19K gene product is an inhibitor of apoptosis induced by tumor necrosis factor-a (TNF-a) during viral infection. We report that E1B 19K inhibited neither caspase-8 activation nor caspase-8-dependent Bid cleavage by TNF-a. Rather, TNF-a induced a Bid-dependent conformational change in Bax that allowed an interaction between E1B 19K and conformaionally altered Bax, which caused inhibition of cytochrome c release and caspase-9 activation. E1B 19K expression interrupted caspase-3 processing, permitting cleavage to remove the p12 subunit but not the prodomain consistent with caspase-8 amd mpt caspase-9 enzymatic activity. Thus, E1B 19K blocks TNF-a-mediated death signaling by inhibiting a specific form of Bax that interrupts caspase activation downstream of caspase-8 and upstream of caspase-9. |
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| UH1042 | The Effect of Recombinant Human Hyaluronidase on Dexamethasone Penetration into the Posterior Segment of the Eye After Sub-Tenon’s Injection |
| IGOR KOZAK, OZCAN R. KAYIKCIOGLU, LINGYUN CHENG, IRYNA FALKENSTEIN, GABRIEL A. SILVA, DIANA X. YU, and WILLIAM R. FREEMAN | |
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The aim of this study was to investigate the extent if recombinant human hyaluronidase (rhuPH20) can enhance trans-scleral penetration of sub-Tenon’s dexamethasone (DM) into the posterior segment of the eye. Methods: rhuPH20 was purified from conditioned media through a series of ion exchange, hydrophobic interaction, aminophenylboronate, and hydroxyapatite chromatography to greater than 90% purity based upon specific activity. Only the right eye of each rabbit was injected. The first group (n 16) received an injection of DM and rhuPH20, whereas the second group (n 16) received DM only. The eyes were enucleated 1, 2, 3, and 6 h after the injection, and the choroid, retina, vitreous, aqueous, and serum were harvested. DM concentration was assessed by mass spectrometry. Histology (n 2) and immunohistochemistry (n 2) was performed to detect toxicity and the presence of the rHuPH20, respectively. Results: We observed no histopathologic damage to ocular tissues after sub-Tenon’s injection. This enzyme significantly increased DM level in the choroid and the retina 3 h after administration. The rise in levels was transient returning to normal levels by 6 h. Conclusions: Sub-Tenon’s coinjection of rHuPH20 with DM resulted in a general increase in DM levels in ocular tissues and the serum, with significant increase in the choroid and the retina, 3 h after administration. |
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| UH1043 | PET Imaging of Soluble Yttrium-86-Labeled Carbon Nanotubes in Mice |
| MICHAEL R. MCDEVITT, DEBJIT CHATTOPADHYAY, JASPREET S. JAGGI, RONALD D. FINN, PAT B. ZANZONICO, CARLOS VILLA1, DIEGO REY, JUANA MENDENHALL, CARL A. BATT, JON T. NJARDARSON, DAVID A. SCHEINBERG | |
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The potential medical applications of nanomaterials are shaping the landscape of the nanobiotechnology field and driving it forward. A key factor in determining the suitability of these nanomaterials must be how they interface with biological systems. Single walled carbon nanotubes (CNT) are being investigated as platforms for the delivery of biological, radiological, and chemical payloads to target tissues. CNT are mechanically robust graphene cylinders comprised of sp2-bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms. In order to evaluate the potential usefulness of this CNT scaffold, we undertook an imaging study to determine the tissue biodistribution and pharmacokinetics of prototypical DOTAfunctionalized CNT labeled with yttrium-86 and indium-111 (86Y-CNT and 111In-CNT, respectively) in a mousemodel. Methodology and Principal Findings. The 86Y-CNT construct was synthesized from amine-functionalized, water-soluble CNT by covalently attaching multiple copies of DOTA chelates and then radiolabeling with the positron-emitting metal-ion, yttrium-86. A gammaemitting 111In-CNT construct was similarly prepared and purified. The constructs were characterized spectroscopically, microscopically, and chromatographically. The whole-body distribution and clearance of yttrium-86 was characterized at 3 and 24 hours post-injection using positron emission tomography (PET). The yttrium-86 cleared the blood within 3 hours and distributed predominantly to the kidneys, liver, spleen and bone. Although the activity that accumulated in the kidney cleared with time, the whole-body clearance was slow. Differential uptake in these target tissues was observed following intraveneous or intraperitoneal injection. Conclusions. The whole-body PET images indicated that the major sites of accumulation of activity resulting from the administration of 86Y-CNT were the kidney, liver, spleen, and to a much less extent the bone. Blood clearance was rapid and could be beneficial in the use of short-lived radionuclides in diagnostic applications. |
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| UH1044 | Bubble Elimination on the Surface of a Contact Lens Submerged in De-ionized Water |
| ANDREW SHABASHEVICH, MECHANICAL ENGINEERING, GREGORY PENOYER, MECHANICAL ENGINEERING, JESSICA PIERCE, MECHANICAL ENGINEERING, ANTHONY KUKLA, MECHANICAL ENGINEERING, WILLIAM DUGAN, MECHANICAL ENGINEERING, GAURAV SANGHI, INDUSTRIAL ENGINEERING, PIYUSH AGGARWALA, ELECTRICAL ENGINEERING | |
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A formal research and development process was used to investigate methods for the removal of bubbles found on the surface of a contact lens submerged in de-ionized water. After extensive testing, it was determined that ultrasound can remove well over 99% of the bubbles from a contact lens. The process involves sending ultrasonic pressure waves through the degassed and de-ionized water that holds the contact lens. This method proved to be very reliable, will easily integrate into the existing manufacturing process, and meets all the requirements specified by the costumer, Bausch and Lomb. |
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| UH1045 | Tumor Targeting with Antibody-Functionalized, Radiolabeled Carbon Nanotubes |
| MICHAEL R. MCDEVITT, DEBJIT CHATTOPADHYAY, JASPREET S. JAGGI, RONALD D. FINN, PAT B. ZANZONICO, CARLOS VILLA1, DIEGO REY, JUANA MENDENHALL, CARL A. BATT, JON T. NJARDARSON, DAVID A. SCHEINBERG | |
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Single-walled carbon nanotubes (CNT) are mechanically robust graphene cylinders with a high aspect ratio that are comprised of sp2-bonded carbon atoms and possessing highly regular structures with defined periodicity. CNT exhibit unique mechanochemical properties that can be exploited for the development of novel drug delivery platforms.Wehypothesized that novel prototype nanostructures consisting of biologics, radionuclides, fluorochromes, and CNT could be synthesized and designed to target tumor cells. Methods: Tumor-targeting CNT constructs were synthesized from sidewall-functionalized, water-soluble CNT platforms by covalently attaching multiple copies of tumorspecific monoclonal antibodies, radiometal-ion chelates, and fluorescent probes. The constructs were characterized spectroscopically, chromatographically, and electrophoretically. The specific reactivity of these constructs was evaluated in vitro by flow cytometry and cell-based immunoreactivity assays and in vivo using biodistribution in a murine xenograft model of lymphoma. Results: A soluble, reactive CNT platform was used as the starting point to build multifunctional constructs with appended antibody, metal-ion chelate, and fluorescent chromophoremoieties to effect specific targeting, to carry and deliver a radiometal-ion, and to report location, respectively. These nanoconstructs were found to be specifically reactive with the human cancer cells they were designed to target in vivo in a model of disseminated human lymphoma and in vitro by flow cytometry and cell-based immunoreactivity assays versus appropriate controls. Conclusion: The key achievement in these studies was the selective targeting of tumor in vitro and in vivo by the use of specific antibodies appended to a soluble, nanoscale CNT construct. The ability to specifically target tumor with prototype-radiolabeled or fluorescent-labeled, antibody-appended CNT constructs was encouraging and suggested further investigation of CNT as a novel delivery platform. Key Words: single-walled carbon nanotubes; Rituximab; DOTA; anoconstructs; nanotechnology. |
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| UH1046 | Nigrostriatal Dysfunction in Familial Alzheimer’s Disease-Linked APPswe/PS1 E9 Transgenic Mice |
| SYLVIA E. PEREZ, ORLY LAZAROV, JAMES B. KOPRICH, ER-YUN CHEN, VIRGINIA RODRIGUEZ-MENENDEZ, JACK W. LIPTON, SANGRAM S. SISODIA, AND ELLIOTT J. MUFSON | |
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Alzheimer’s disease (AD) is often accompanied by extrapyramidal signs attributed to nigrostriatal dysfunction. The association between amyloid deposition and nigrostriatal degeneration is essentially unknown. We showed previously that the striatum and the substantia nigra of transgenic mice harboring familial AD (FAD)-linked APPswe/PS1 E9 mutants exhibit morphological alterations accompanied by amyloid- (A ) deposition (Perez et al., 2004). In the present study,wefurther investigated the interaction betweenA deposition and dopaminergic nigrostriatal dysfunction, by correlating morphological and biochemical changes in the nigrostriatal pathway with amyloid deposition pathology in the brains of 3- to 17-month-old APPswe/PS1 E9 transgenic mice and age-matched wild-type controls. We show thatA deposition is pronounced in the striatum of APPswe/PS1 E9 mice at 6 months of age, and the extent of deposition increases in an age-dependent manner. Tyrosine hydroxylase (TH)-positive dystrophic neurites with rosette or grape-like cluster disposition are observed adjacent to A plaques and display multilaminar, multivesicular, and dense-core bodies as well as mitochondria. In addition, an age-dependent increase ofTHprotein levels are shown in nigral cells in these mutant mice. Using HPLC analysis, we found a reduction in the dopamine metabolite DOPAC in the striatum of these mice. These findings show a close association between amyloid deposition and nigrostriatal pathology and suggest that altered FAD-linked amyloid metabolism impairs, at least in part, the function of dopaminergic neurons. |
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| UH1047 | GlpD and PlsB Participate in Persister Cell Formation in Escherichia coli |
| AMY L. SPOERING, MARIN VULIC, AND KIM LEWIS | |
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Bacterial populations produce dormant persister cells that are resistant to killing by all antibiotics currently in use, a phenomenon known as multidrug tolerance (MDT). Persisters are phenotypic variants of the wild type and are largely responsible for MDT of biofilms and stationary populations. We recently showed that a hipBA toxin/antitoxin locus is part of the MDT mechanism in Escherichia coli. In an effort to find additional MDT genes, an E. coli expression library was selected for increased survival to ampicillin. A clone with increased persister production was isolated and was found to overexpress the gene for the conserved aerobic sn-glycerol-3-phosphate dehydrogenase GlpD. The GlpD overexpression strain showed increased tolerance to ampicillin and ofloxacin, while a strain with glpD deleted had a decreased level of persisters in the stationary state. This suggests that GlpD is a component of the MDT mechanism. Further genetic studies of mutants affected in pathways involved in sn-glycerol-3-phosphate metabolism have led to the identification of two additional multidrug tolerance loci, glpABC, the anaerobic sn-glycerol-3-phosphate dehydrogenase, and plsB, an snglycerol-3-phosphate acyltransferase. |
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| UH1048 | Redox Cycling of Phenol Induces Oxidative Stress in Human Epidermal Keratinocytes |
| ANNA A. SHVEDOVA, CHOUDARI KOMMINENI, BETTRICIA A. JEFFRIES, VINCENT CASTRANOVA, YULIA Y. TYURINA, VLADIMIR A. TYURIN, ELENA A. SERBINOVA, JAMES P. FABISIAK, AND VALERIAN E. KAGAN | |
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A variety of phenolic compounds are utilized for industrial production of phenol-formaldehyde resins, paints, lacquers, cosmetics, and pharmaceuticals. Skin exposure to industrial phenolics is known to cause skin rash, dermal inflammation, contact dermatitis, leucoderma, and cancer promotion. The biochemical mechanisms of cytotoxicity of phenolic compounds are not well understood. We hypothesized that enzymatic one-electron oxidation of phenolic compounds resulting in the generation of phenoxyl radicals may be an important contributor to the cytotoxic effects. Phenoxyl radicals are readily reduced by thiols, ascorbate, and other intracellular reductants (e.g., NADH, NADPH) regenerating the parent phenolic compound. Hence, phenolic compounds may undergo enzymatically driven redox-cycling thus causing oxidative stress. To test the hypothesis, we analyzed endogenous thiols, lipid peroxidation, and total antioxidant reserves in normal human keratinocytes exposed to phenol. Using a newly developed cis-parinaric acid-based procedure to assay site-specific oxidative stress in membrane phospholipids, we found that phenol at subtoxic concentrations (50 microM) caused oxidation of phosphatidylcholine and hosphatidylethanolamine (but not of phosphatidylserine) in keratinocytes. Phenol did not induce peroxidation of phospholipids in liposomes prepared from keratinocyte lipids labeled by cis-parinaric acid. Measurements with ThioGlo-1 showed that phenol depleted glutathione but did not produce thiyl radicals as evidenced by our high-performance liquid chromatography measurements of GS.-5, 5-dimethyl1pyrroline N-oxide nitrone. Additionally, phenol caused a significant decrease of protein SH groups. Luminol-enhanced chemiluminescence assay demonstrated a significant decrease in total antioxidant reserves of keratinocytes exposed to phenol. Incubation of ascorbate-preloaded keratinocytes with phenol produced an electron paramagnetic resonance-detectable signal of ascorbate radicals, suggesting that redox-cycling of one-electron oxidation products of phenol, its phenoxyl radicals, is involved in the oxidative effects. As no cytotoxicity was observed in keratinocytes exposed to 50 microM or 500 microM phenol, we conclude that phenol at subtoxic concentrations causes significant oxidative Stress. |
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| UH1049 | Muscarinic Stimulation of Pancreatic Insulin and Glucagon Release Is Abolished in M3 Muscarinic Acetylcholine Receptor Deficient Mice |
| ALOKESH DUTTAROY, CHARLES L. ZIMLIKI, DINESH GAUTAM, YINGHONG CUI, DAVID MEARS, ANDJURGEN WESS | |
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Pancreatic muscarinic acetylcholine receptors play an important role in stimulating insulin and glucagon secretion from islet cells. To study the potential role of the M3 muscarinic receptor subtype in cholinergic stimulation of insulin release, we initially examined the effect of the muscarinic agonist, oxotremorine-M (Oxo-M), on insulin secretion from isolated pancreatic islets prepared from wild-type (WT) and M3 receptor deficient mice (M3 / and M3 / mice). At a stimulatory glucose level (16.7 mmol/l), Oxo-M strongly potentiated insulin output from islets of WT mice. Strikingly, this effect was completely abolished in islets from M3 / mice and significantly reduced in islets from M3 / mice. Additional in vitro studies showed that Oxo-M mediated glucagon release was also virtually abolished in islets from M3 / mice. Consistent with the in vitro data, in vivo studies showed that M3 / mice displayed reduced serum insulin and plasma glucagon levels and a significantly blunted increase in serum insulin after an oral glucose load. Despite the observed impairments in insulin release, M3 / mice showed significantly reduced blood glucose levels and even improved glucose tolerance, probably due to the reduction in plasma glucagon levels and the fact that M3 / mice are hypophagic and lean. These findings provide important new insights into the metabolic roles of the M3 muscarinic receptor subtype. Diabetes 53:1714–1720, 2004 |
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| UH1050 | Epigenetic regulation of telomerase in retinoid-induced differentiation of human leukemia cells |
| WILLIAM K. LOVE, JOEL B. BERLETCH, LUCY G. ANDREWS, and TRYGVE O. TOLLEFSBOL | |
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Changes in the promoter methylation of hTERT, the gene that encodes telomerase, a ribonucleoprotein responsible for replacing telomeric repeats, have been demonstrated in differentiating cells where hTERT is inhibited, suggesting epigenetic regulation of hTERT. Alltrans retinoic acid (ATRA) induces differentiation in human leukemia cells and has had significant clinical success treating promyelocytic leukemia in what is termed ‘differentiation therapy’. It is thought that the inhibition of telomerase is a target of retinoids and is closely tied to the differentiated phenotype. This study demonstrates the epigenetic changes associated with ATRA-induced inhibition of telomerase activity, including the hypoacetylation and hypermethylation of the hTERT promoter. Further, we have found changes in the differential expression of the three DNA methyltransferases during ATRA-induced differentiation of HL60 human leukemia cells. These results suggest that alteration of DNA methylation may play a role in the activation of telomerase in cancer cells and that epigenetic mechanisms may represent a target for differentiation therapy mechanisms. We propose that epigenetic changes in the hTERT promoter represent a stable locking mechanism in the retionoid-induced suppression of telomerase acitivity. |
