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De Marchi F, Galeotti G, Simenas M, Gallagher MC, Hamzehpoor E, MacLean O, Rao RM, Chen Y, Dettmann D, Contini G, Tornau EE, Ebrahimi M, Perepichka DF, Rosei F. Temperature-induced molecular reorganization on Au(111) driven by oligomeric defects. Nanoscale 2019; 11:19468-19476. [PMID: 31535121 DOI: 10.1039/c9nr06117g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The formation of ordered molecular structures on surfaces is determined by the balance between molecule-molecule and molecule-substrate interactions. Whether the aggregation process is guided by non-covalent forces or on-surface reactions, a deeper understanding of these interactions is pivotal to formulating a priori predictions of the final structural features and the development of bottom-up fabrication protocols. Theoretical models of molecular systems corroborate the information gathered through experimental observations and help explain the thermodynamic factors that underpin on-surface phase transitions. Here, we report a scanning tunneling microscopy investigation of a tribromo-substituted heterotriangulene on the Au(111) surface, which initially forms an extended close-packed ordered structure stabilized by BrBr halogen bonds when deposited at room temperature. X-ray photoelectron spectroscopy reveals that annealing the self-assembled layer induces a fraction of the molecular precursors to partially dehalogenate that in turn leads to the formation of a less stable BrO non-covalent network which coexists with the short oligomers. Density functional theory (DFT) and Monte Carlo (MC) simulations illustrate how dimer moieties act as defects whose steric hindrance prevents the retention of the more stable configuration. A small number of dimers is sufficient to drive the molecular reorganization into a lower cohesive energy phase. Our study shows the importance of a combined DFT - MC approach to understand the evolution of molecular systems on substrates.
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Affiliation(s)
- F De Marchi
- Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boulevard Lionel-Boulet, Varennes, Québec, Canada J3X 1S2.
| | - G Galeotti
- Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boulevard Lionel-Boulet, Varennes, Québec, Canada J3X 1S2. and Istituto di Struttura della Materia, CNR, Via Fosso del Cavaliere 100, 00133 Roma, Italy
| | - M Simenas
- Faculty of Physics, Vilnius University, Saulėtekio 9, LT-10222 Vilnius, Lithuania
| | - M C Gallagher
- Department of Physics, Lakehead University, 955 Oliver Rd, Thunder Bay, Ontario, Canada P7B 5E1.
| | - E Hamzehpoor
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Québec, Canada H3A 0B8.
| | - O MacLean
- Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boulevard Lionel-Boulet, Varennes, Québec, Canada J3X 1S2.
| | - R M Rao
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Québec, Canada H3A 0B8.
| | - Y Chen
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Québec, Canada H3A 0B8.
| | - D Dettmann
- Istituto di Struttura della Materia, CNR, Via Fosso del Cavaliere 100, 00133 Roma, Italy
| | - G Contini
- Istituto di Struttura della Materia, CNR, Via Fosso del Cavaliere 100, 00133 Roma, Italy and Department of Physics, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Roma, Italy
| | - E E Tornau
- Semiconductor Physics Institute, Center for Physical Sciences and Technology, Saulėtekio 3, LT-10222 Vilnius, Lithuania
| | - M Ebrahimi
- Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boulevard Lionel-Boulet, Varennes, Québec, Canada J3X 1S2.
| | - D F Perepichka
- Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, Québec, Canada H3A 0B8.
| | - F Rosei
- Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boulevard Lionel-Boulet, Varennes, Québec, Canada J3X 1S2.
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Rao RM, Kumar A, Vekaria P, Yacoub A, Skikne B, McGuirk J. Abstract 2046: Egr-1 promotes bone marrow fibrosis in primary myelofibrosis. Cancer Res 2019. [DOI: 10.1158/1538-7445.am2019-2046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Primary myelofibrosis (PMF) is a myeloproliferative neoplasm (MPN) characterized by JAK-STAT-activated proliferation of leukemia cells and progressive bone marrow fibrosis. However little is known about the bone marrow stromal cell (BMSC) intrinsic factors that work in concert with leukemia stem cells (LSCs) to promote fibrosis of the bone marrow in PMF. In this study we developed an in vitro model to simulate bone marrow fibrosis in PMF by exposing cultured BMSC, HS-5 cells to PMF-patient plasma. We observed that exposure of BMSCs to PMF plasma but not normal serum increased total cellular and mitochondrial reactive oxygen species (ROS), as well as Early growth response 1 (Egr-1) and its target gene expression in BMSCs. Egr-1 is a transcription factor that upregulates fibrosis-associated genes, and is acutely induced by numerous cytokines (e.g. TGF-β, PDGFα) that are elevated in PMF. Utilizing this model, we performed RNA sequencing of HS-5 cells exposed to PMF plasma. We observed that PMF plasma exposure alters pathways responsible for multiple DNA damage responses, G1/s cell cycle checkpoint regulation and protein homeostasis. Since PMF progression is associated with enhanced oxidative stress which induces both DNA damage and Egr-1 expression, we determined the effect of anti-oxidants on the induction Egr-1 and fibrosis associated genes in BMSCs following treatment with PMF plasma. We report that treatment with N-acetyl-cysteine (a ROS scavenger) and mitotempo (a mitochondrial ROS scavenger) abrogated the up-regulation of PMF plasma-induced fibrosis-associated genes in BMSCs. Additionally, knockdown of Egr-1 in BMSCs resulted in the down-regulation of collagen 1A1 and connective tissue growth factor (CTGF) following exposure to PMF plasma. These findings suggest that PMF plasma induces ROS and promotes the upregulation of pro-fibrotic genes in an Egr-1-dependent manner in PMF. Our studies suggest that inhibition of ROS and Egr-1-induced gene transcription could be used as a strategy to alleviate bone marrow fibrosis; a disease complication in PMF for which there are no approved therapies.
Citation Format: Rekha M. Rao, Amar Kumar, Pratikkumar Vekaria, Abdulraheem Yacoub, Barry Skikne, Joseph McGuirk. Egr-1 promotes bone marrow fibrosis in primary myelofibrosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2046.
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Affiliation(s)
| | - Amar Kumar
- 1Univ. of Kansas Medical Ctr., Kansas City, KS
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Vekaria P, Vallurupalli A, Subramaniam D, Schoenen F, McGuirk J, Rao RM. Abstract 346: Targeting DNA repair with the combination of p97 and HDAC6 inhibitors in mantle cell lymphoma. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
p97 is an ATPase which is involved in remodeling multi-subunit protein complexes. It plays a pivotal role in the retrotranslocation and proteasomal degradation of misfolded ubiquitinated proteins in the endoplasmic reticulum. In association with cytosolic histone deacetylase 6 (HDAC6), p97 promotes the autophagic degradation of polyubiquitylated proteins and damaged organelles. More recently p97 has been implicated in regulating cell division and in facilitating DNA repair by promoting the recruitment of DNA repair proteins to the site of DNA damage. In this study, we determined the molecular mechanisms through which HDAC6 promotes p97 function in mantle cell lymphoma (MCL) cells. We report that treatment of MCL cells with the p97 inhibitors, DBeQ, ML240, NMS-873 and CB-5083 induces ER stress markers GRP78 and CHOP and resulted in dose-dependent apoptosis. Treatment of Z138C xenografts in NSG mice with CB-5083, the first in-class p97 inhibitor, resulted in increased accumulation of polyubiquitylated proteins and improved survival in vivo compared to control mice. Co-treatment with CB-5083 and the HDAC6-selective inhibitor ACY-1215, resulted in accumulation of polyubiquitylated proteins, impaired DNA double-stranded break repair and resulted in the partial depletion of BRCA1 and Cyclin D1 in MCL cells compared to either agent alone. We also demonstrate that shRNA-mediated knockdown of HDAC6 induced enhanced accumulation of H2AX-γ under basal conditions and following treatment with CB-5083 in cultured and primary MCL cells. Finally, treatment of MCL cells with p97 inhibitors and ACY-1215 results in synergistic apoptotic cell death in MCL cells. Collectively our studies create a strong rationale to test efficacy of the combination of p97 inhibitors in combination with HDAC6 inhibitors in MCL.
Citation Format: Pratikkumar Vekaria, Anusha Vallurupalli, Dharmalingam Subramaniam, Frank Schoenen, Joseph McGuirk, Rekha M. Rao. Targeting DNA repair with the combination of p97 and HDAC6 inhibitors in mantle cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 346.
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Rao RM, Vekaria PH, Home T, Vallurupalli A, Yacoub A, Schoenen F, McGuirk J. Abstract 1058: Synergistic activity of p97 inhibitors with histone deacetylase 6 inhibitors in mantle cell lymphoma. Cancer Res 2017. [DOI: 10.1158/1538-7445.am2017-1058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
p97, or valosin-containing protein (VCP), is an ATPase whose function is essential to restore protein homeostasis in cells. Working in concert with the ubiquitin proteasome system, p97 promotes the retrotranslocation of misfolded proteins from the endoplasmic reticulum and/or their degradation. Consequently, p97 inhibition has emerged as a novel therapeutic target in cancer cells, especially those that depend on high protein turnover and/or ER function. p97 is also present in a complex with many protein complexes including the HSP90, histone deacetylase (HDAC) 6 and heat shock factor 1 (HSF1)-also called the repressive complex. p97 participates in the disaggregation of the repressive complex to regulate HSP90 and HSF1 function under stressed conditions. Accumulation of misfolded polyubiquitylated proteins in the cytosol or on damaged organelles promotes the binding of p97 to polyubiquitylated proteins in an HDAC6-dependent manner and promotes their turnover by autophagic degradation. Given that perturbation of protein homeostasis and ER function induces apoptosis as well as autophagy in B cell malignancies such as multiple myeloma and mantle cell lymphoma (MCL), we hypothesized that inhibition of p97 function in combination with HDAC6 inhibitors would induce proteotoxic stress and/or apoptotic cell death in MCL cells. In this study, we report that the p97 inhibitors DBeQ, ML240 and NMS-873 induce a dose-dependent loss of cell viability in cultured and primary MCL cells. Treatment of MCL cells with ML240 induces the accumulation of polyubiquitylated proteins and induces markers of ER stress such as glucose regulated protein 78 (GRP78) and phosphorylated eukaryotic initiation factor 2 (eIF2) α as well as the autophagic markers LC3-B and p62 (protein whose accumulation is suggestive of reduced autophagic clearance of misfolded proteins). Co-treatment with ML240 and the HDAC6 inhibitor ACY-1215 induces more accumulation of polyubiquitylated proteins and markers of enhanced ER stress as well as autophagy, than either agent alone. Mechanistically we determined that co-treatment with ML240 and ACY-1215 inhibits the binding of p97 to polyubiquitylated proteins and HDAC6, resulting in the reduced clearance of cytotoxic protein aggregates in the cells. Co-treatment with ML240 and ACY-1215 also induces the accumulation of cytosolic polyubiquitylated proteins and their co-localization with LC-3B puncta as demonstrated by immunofluorescent microscopy. These observations are suggestive of enhanced initiation of autophagy but not its completion. Consequently, treatment of MCL cells with ML240 and ACY-1215 resulted in enhanced proteotoxic stress and synergistic apoptotic cell death in MCL cells. Collectively our studies create a strong rationale to test efficacy of the combination of p97 inhibitors in combination with HDAC6 inhibitors in MCL.
Citation Format: Rekha M. Rao, Pratikkumar H. Vekaria, Trisha Home, Anusha Vallurupalli, Abdulraheem Yacoub, Frank Schoenen, Joseph McGuirk. Synergistic activity of p97 inhibitors with histone deacetylase 6 inhibitors in mantle cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1058. doi:10.1158/1538-7445.AM2017-1058
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Affiliation(s)
| | | | - Trisha Home
- 1Univ. of Kansas Medical Ctr., Kansas City, KS
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Ganguly S, Home T, Gunewardena S, Weir S, McGuirk J, Rao RM. Abstract 3632: Synergistic interaction of auranofin with PARP inhibitors in ATM-proficient mantle cell lymphoma. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-3632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Auranofin (AF) (Ridaura®) is an oral, FDA-approved, lipophilic, gold-containing compound that was used for treating arthritis. Its primary mechanism of action is the inhibition of thioredoxin reductase (TRR) activity. It consequently induces oxidative/ER stress and also inhibits Heat shock protein (Hsp) 90 chaperone function. Ataxia-telangiectasia mutated and Rad3-related (ATR), Brca1, Chk1 and DNA-PK are Hsp90 client proteins that participate in DNA repair pathways. Based on our observation that AF induces DNA damage, we evaluated whether treatment with AF also impairs Hsp90-dependent DNA damage repair pathways in Mantle Cell Lymphoma (MCL) cells. It has been reported that ATM mutations are found in about 50% cases of MCL. Earlier studies have shown that ATM mutant MCL cells are more sensitive to poly-ADP ribose polymerase (PARP) inhibitors in vitro and in vivo. We hypothesized that by inhibiting Hsp90-dependent DNA repair pathways (such as the ATR pathway), AF would sensitize ATM-proficient MCL cells to PARP inhibition by ABT-888. We demonstrate that treatment of ATM-proficient MCL cell lines, JeKo-1, MO2058 and Z138C with AF induced reactive oxygen species (ROS) levels and resulted in a concomitant decrease in TRR activity. Microarray analysis of AF-treated primary MCL cells revealed that AF significantly altered heat shock response genes, ER and oxidative stress-inducible genes and a subset of genes that were regulated by ATM or Brca1. Treatment with AF also induced Hsp90 hyperacetylation and resulted in the depletion of Hsp90 client proteins including ATR, AKT and Cyclin D1 in MCL cells. Exposure to AF induced significantly more apoptosis in primary MCL cells, as compared to CD19+ normal B cells, CD34+ human cord blood and bone marrow progenitor cells (< 15% apoptosis) (p < 0.01). Co-treatment of MCL cells with AF and the PARP inhibitor ABT-888 resulted in synergistic increase in apoptosis of ATM-proficient MCL cells, with an increase in the induction of γH2AX foci and depletion of p-Chk1 (a downstream target of ATR signaling). This was accompanied with a concomitant increase in the levels of the ER stress-induced transcription factor CHOP (C/EBP homologous protein), cleaved Caspase 3 and PARP. Collectively, our data suggests the synthetic lethal effects observed by the simultaneous inhibition of DNA repair pathway(s) and PARP activity can be extended to ATM-proficient MCL cells. These pre-clinical studies create a strong rationale to determine the in vivo activity of the combination ABT-888 with AF in MCL.
Citation Format: Siddhartha Ganguly, Trisha Home, Sumedha Gunewardena, Scott Weir, Joseph McGuirk, Rekha M. Rao. Synergistic interaction of auranofin with PARP inhibitors in ATM-proficient mantle cell lymphoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3632. doi:10.1158/1538-7445.AM2015-3632
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Affiliation(s)
| | - Trisha Home
- University of Kansas Medical Center, Kansas City, KS
| | | | - Scott Weir
- University of Kansas Medical Center, Kansas City, KS
| | | | - Rekha M. Rao
- University of Kansas Medical Center, Kansas City, KS
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Rao RM, Abdulraheem Y, Kambhampati S, Ganguly S. Abstract LB-109: Therapeutic targeting of Heat shock factor 1 in chronic lymphocytic leukemia. Cancer Res 2014. [DOI: 10.1158/1538-7445.am2014-lb-109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Heat shock factor 1 (HSF1) is a stress-activated transcription factor, that up-regulates the transcription of heat shock proteins (Hsps) and a growing list of tumor-promoting genes. HSF1-induced genes promote protein folding and maturation (through Hsps and associated co-chaperones) as well as orchestrate the transcription of tumor-promoting genes (for e.g., VEFGR, HIF1-alpha, GLUT-1, etc). In this study we propose to evaluate the efficacy of inhibiting HSF1 in Chronic Lymphocytic Leukemia (CLL), a disease that invariably relapses after patients show complete or partial response to first line chemotherapy. Consistent with the established tumor-promoting roles of HSF1, we report that CD19+ B cells isolated from relapsed/refractory CLL patients show high levels of immunofluorescent, nuclear HSF1 staining compared to normal CD19+ B cells, where it is weakly expressed and pre-dominantly cytosolic. CD19+ B primary CLL cells also show enhanced expression of HSF1 as assessed by immunoblot analysis compared to normal CD19+ cells. Treatment of cultured and primary CLL CD19+ B cells with the HSF1 inhibitor triptolide causes a dose-dependent increase in apoptosis, while relatively sparing normal CD19+ B cells. Treatment with triptolide results in the reduced expression of Hsp40, Hsp70 and Hsp27 proteins and a concomitant increase in the PARP cleavage and Caspase 3 cleavage in cultured and primary CLL cells. Lentiviral shRNA-mediated knockdown of HSF1 or triptolide treatment decreased the levels of Bcl-XL and pro-survival signaling molecules, phosphorylated STAT3 (Y-705) and AKT (S473). Based on the established role of Hsps in cytoprotection and resistance to chemotherapy, we hypothesized that inhibition of HSF1 would sensitize CLL cells to agents that promote the accumulation of misfolded proteins (for e.g. Hsp90 inhibitors) or inhibit their disposal (for e.g. treatment with autophagy inhibitors) by inducing proteotoxicity. Consistent with this hypothesis, knockdown of HSF1 or co-treatment with triptolide and the autophagy inhibitor chloroquine resulted in superior anti-CLL activity compared to treatment with either agent alone. Similarly, knockdown of HSF1 or its inhibition with triptolide also sensitized CLL cells to the Hsp90 inhibitor, 17-Dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG). These pre-clinical studies provide a strong rationale to test the in vitro and in vivo activity of HSF1 inhibitors in combination with agents that promote proteotoxic stress against CLL.
Citation Format: Rekha M. Rao, Yacoub Abdulraheem, Suman Kambhampati, Siddhartha Ganguly. Therapeutic targeting of Heat shock factor 1 in chronic lymphocytic leukemia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-109. doi:10.1158/1538-7445.AM2014-LB-109
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Affiliation(s)
- Rekha M. Rao
- Kansas University Medical Center, Kansas City, KS
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Veldore VH, Rao RM, Pattanayak S, Tejaswi R, Sahoo R, Venkataswamy E, Prabhudesai SA, Tejaswini BN, Rahman SM, Satheesh CT, Shashidhar SP, Patil S, Kakara S, Krishnamoorthy N, Hazarika D, Gangoli SA, Naik R, Diwakar RB, Ajai Kumar BS. Epidermal growth factor receptor mutation in non-small-cell lung carcinomas: A retrospective analysis of 1036 lung cancer specimens from a network of tertiary cancer care centers in India. Indian J Cancer 2013; 50:87-93. [DOI: 10.4103/0019-509x.117013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Venkannagari S, Rao RM, Fiskus W, Balusu R, Ma H, Bhalla K. Abstract 2076: HSF1 inhibition accentuates the lethal activity of proteasome inhibitor in human pancreatic cancer cells. Cancer Res 2011. [DOI: 10.1158/1538-7445.am2011-2076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Presence of aneuploidy increases the intracellular levels of misfolded proteins and proteotoxic stress phenotype in cancer cells, which is exploited and further accentuated by the therapeutic use of a proteasome inhibitor, e.g., the novel, orally bioavailable carfilzomib (CF). This results in the disruption of the cytosolic complex of the histone deacetylase 6 (HDAC6), the ATPase and segregase p97 and the heat shock factor 1 (HSF1)-a transcription factor involved in the transactivation of heat shock proteins (hsps). In the present studies, we demonstrate that treatment of the pancreatic cancer Hs766T and Panc1 cells with CF increased the levels of misfolded polyubiquitylated proteins, which disrupts the repressive HSF1/hsp90/HDAC6/Vp97 complex. This induces the phosphorylation, nuclear localization and activation of HSF1, which transactivated hsps (e.g., hsp70, hsp40 and hsp27) as an adaptive response to CF-induced proteotoxic stress. Treatment with CF also induced endoplasmic reticulum (ER) stress, represented by upregulation of GRP78 and the pro-apoptotic transcription factor CHOP, which induced the BH3 only pro-apoptotic protein Bim. Treatment with CF also dose-dependently decreased the viability of Hs766T and Panc1 cells. To further elucidate the role of HSF1 in the adaptive, protective response to CF-induced proteotoxic stress, we stably knocked down HSF1 in Hs766T cells. As compared to the control cells, following heat shock, Hs766T cells with knockdown (KD) of HSF1 displayed reduced expression of hsps. In the HSF1-KD versus the control Hs766T cells, treatment with CF resulted in a dose-dependent induction of polyubiquitylated proteins, GRP78, CHOP, and Bim, as well as induced significantly more apoptosis. HSF1-KD versus the control Hs766T cells exhibited markedly lower levels of HDAC6 and, consequently, displayed reduced CF-induced perinuclear protective aggresome formation, as determined by confocal microscopy. Additionally, as compared to the control cells, Hs766T cells with HSF1-KD demonstrated higher levels of p-AMPK and CF (5 to 20 nM) or the pan-HDAC inhibitor panobinostat (PS, 50 nM)-induced autophagy, as demonstrated by the accumulation of LC3-II (by immunoblot analysis) and LC3 puncta by immunofluorescent staining. Importantly, co-treatment with the autophagy inhibitor hydroxy-chloroquine (HCQ) induced more CF-induced cell death of HSF1-KD versus the control Hs766T cells. Using an acid-sensitive mCherry-GFP-LC3 reporter, we determined that the induction of LC3-II in the Hs766T HSF1-KD cells is the result of enhanced autophagic flux and not due to inefficient fusion of autophagosomes with lysosomes. Collectively, these findings indicate that inhibition of the transcriptional activity of HSF1 sensitizes pancreatic cancer cells to CF or PS-induced cells death, which is augmented by co-treatment with an autophagy inhibitor.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2076. doi:10.1158/1538-7445.AM2011-2076
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Affiliation(s)
| | - Rekha M. Rao
- 1University of Kansas Cancer Center, Kansas City, KS
| | - Warren Fiskus
- 1University of Kansas Cancer Center, Kansas City, KS
| | - Ramesh Balusu
- 1University of Kansas Cancer Center, Kansas City, KS
| | - Hongwei Ma
- 1University of Kansas Cancer Center, Kansas City, KS
| | - Kapil Bhalla
- 1University of Kansas Cancer Center, Kansas City, KS
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Banuprakash S, Jolappara M, Kesavadas C, Saini J, Rao RM, Radhakrishnan VV. Atypical fungal granuloma of the sphenoid wing. J Neuroradiol 2009; 36:233-6. [PMID: 19679356 DOI: 10.1016/j.neurad.2009.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2009] [Revised: 06/25/2009] [Accepted: 06/29/2009] [Indexed: 10/20/2022]
Abstract
A 29-year-old immunocompetent patient presented with a 3-month history of headache and vomiting. Computed tomography (CT) and conventional magnetic resonance imaging (MRI) revealed a mass lesion in the right sphenoid wing. The conventional imaging findings were typical of meningioma. However, diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI) and perfusion-weighted imaging (PWI) all revealed details that were unusual for a meningioma. DWI showed diffusion blackout, perfusion was not raised in PWI, and susceptibility effects were noted in SWI. Based on these findings, the possibility of granuloma was kept as the differential diagnosis. Histopathological examination of the lesion was suggestive of fungal granuloma. This case report highlights the importance of advanced neuroimaging techniques in differentiating meningioma and granuloma.
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Affiliation(s)
- S Banuprakash
- Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST), Medical College P.O, Trivandrum 695011, India
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Charles AK, Hisheh S, Liu D, Rao RM, Waddell BJ, Dickinson JE, Rao AJ, Dharmarajan AM. The expression of apoptosis related genes in the first trimester human placenta using a short term in vitro model. Apoptosis 2005; 10:135-40. [PMID: 15711929 DOI: 10.1007/s10495-005-6068-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using in vitro model for studying the induction and inhibition of spontaneous apoptosis in human first trimester placental villi, mediated by the free radical scavenger SOD, we have examined the expression of bcl-xL, bax, Caspase-3 and PARP (Poly ADP-ribosyl). An increase in apoptosis was associated with activation of PARP and an increase and activation of Caspase-3. There was no significant change in bcl-x or bax. Therefore bcl-x and bax do not appear to have a significant role in apoptosis in the first trimester in vitro. Cleavage of Caspase-3 rather than transcriptional regulation appears to be the main determinant of Caspase-3 activity in first trimester placental villi.
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Affiliation(s)
- A K Charles
- Department of Pathology King Edward Memorial Hospital, University of Western Australia, Perth, Western Australia.
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Bansode RR, Losso JN, Marshall WE, Rao RM, Portier RJ. Pecan shell-based granular activated carbon for treatment of chemical oxygen demand (COD) in municipal wastewater. Bioresour Technol 2004; 94:129-135. [PMID: 15158504 DOI: 10.1016/j.biortech.2003.12.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Revised: 12/11/2003] [Accepted: 12/15/2003] [Indexed: 05/24/2023]
Abstract
The present investigation was undertaken to compare the adsorption efficiency of pecan shell-based granular activated carbon with the adsorption efficiency of the commercial carbon Filtrasorb 200 with respect to uptake of the organic components responsible for the chemical oxygen demand (COD) of municipal wastewater. Adsorption efficiencies for these two sets of carbons (experimental and commercial) were analyzed by the Freundlich adsorption model. The results indicate that steam-activated and acid-activated pecan shell-based carbons had higher adsorption for organic matter measured as COD, than carbon dioxide-activated pecan shell-based carbon or Filtrasorb 200 at all the carbon dosages used during the experiment. The higher adsorption may be related to surface area as the two carbons with the highest surface area also had the highest organic matter adsorption. These results show that granular activated carbons made from agricultural waste (pecan shells) can be used with greater effectiveness for organic matter removal from municipal wastewater than a coal-based commercial carbon.
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Affiliation(s)
- R R Bansode
- Department of Food Science, Louisiana State University Agricultural Center, Food Science Building, Baton Rouge, LA 70803-4200, USA
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Abstract
During the first trimester of pregnancy, the human placenta is an actively dividing and highly invasive tumour-like tissue, while near term, it represents a fully developed, non-invasive unit. In order to understand the molecular basis of this marked difference in the placental phenotypes, an approach based on a differential display-reverse transcription-polymerase chain reaction (DD-RT-PCR) was adopted to analyse changes in gene expression, using total RNA isolated from first-trimester and term placental villi. Using this approach, T-plastin was initially identified as being differentially expressed in the human first-trimester placenta. T-plastin is an actin-bundling protein and is known to be highly expressed in actively dividing cells and up-regulated in several carcinomas. Using a homogenous population of cytotrophoblasts and syncytiotrophoblasts isolated from human placentae, the present authors demonstrate the differential expression of T-plastin in cytotrophoblasts compared with the terminally differentiated syncytiotrophoblasts. The down-regulation of T-plastin expression is further demonstrated in human trophoblastic BeWo cells induced to differentiate using transforming growth factor (TGF)beta1, a growth factor known for its anti-proliferative and anti-invasive response in placental cells. These studies suggest that expression of T-plastin in the placental context may indeed be associated with the enhanced replicative potential of placental trophoblasts.
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Affiliation(s)
- Rekha M Rao
- Department of Biochemistry, Indian Institute of Science, Bangalore 560 012, India
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14
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Abstract
The steroidogenic acute regulatory (StAR) protein promotes intramitochondrial delivery of cholesterol to the cholesterol side-chain cleavage system, which catalyzes the first enzymatic step in all steroid synthesis. Intriguingly, substrate cholesterol derived from lipoprotein can upregulate StAR gene expression. Moreover, substrate oxysterols have been suggested to also play a role. To investigate whether oxysterols can regulate StAR expression, two steroidogenic cell lines, mouse Y1 adrenocortical and MA-10 Leydig tumor cells, were treated with various oxysterols and steroids, including 25-hydroxycholesterol (25 OHC), 22(R)OHC and 20alphaOHC. The majority of these compounds rapidly increased StAR protein levels within as little as 1 h. The most potent oxysterols were 20alphaOHC for Y1 and 25 OHC for MA-10 cells. After 8 h, StAR mRNA abundance also increased whereas there were no detected changes in promoter activity. Thus, in contrast to lipoprotein, oxysterols acutely increase StAR protein levels independently of mRNA abundance, and later increase mRNA levels independently of new gene transcription. Therefore, we propose that oxysterols modulate steroidogenesis at two levels. First, oxysterols may be important in post-transcriptional regulation of StAR activity and production of steroids for paracrine action. Secondly, through direct conversion to steroid, oxysterols may account in part for StAR-independent steroid production in the body.
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Affiliation(s)
- S R King
- Scott Department of Urology, Baylor College of Medicine, Houston, Texas 77030, USA
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15
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Abstract
We report results of experimental and theoretical studies of the vibrational branching ratios for CO 4sigma(-1) photoionization from 20 to 185 eV. Comparison with results for the 2sigma(u)(-1) channel of the isoelectronic N2 molecule shows the branching ratios for these two systems to be qualitatively different due to the underlying scattering dynamics: CO has a shape resonance at low energy but lacks a Cooper minimum at higher energies whereas the situation is reversed for N2.
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Affiliation(s)
- G J Rathbone
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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16
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Bansode RR, Losso JN, Marshall WE, Rao RM, Portier RJ. Adsorption of volatile organic compounds by pecan shell- and almond shell-based granular activated carbons. Bioresour Technol 2003; 90:175-84. [PMID: 12895561 DOI: 10.1016/s0960-8524(03)00117-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The objective of this research was to determine the effectiveness of using pecan and almond shell-based granular activated carbons (GACs) in the adsorption of volatile organic compounds (VOCs) of health concern and known toxic compounds (such as bromo-dichloromethane, benzene, carbon tetrachloride, 1,1,1-trichloromethane, chloroform, and 1,1-dichloromethane) compared to the adsorption efficiency of commercially used carbons (such as Filtrasorb 200, Calgon GRC-20, and Waterlinks 206C AW) in simulated test medium. The pecan shell-based GACs were activated using steam, carbon dioxide or phosphoric acid. An almond shell-based GAC was activated with phosphoric acid. Our results indicated that steam- or carbon dioxide-activated pecan shell carbons were superior in total VOC adsorption to phosphoric acid-activated pecan shell or almond shell carbons, inferring that the method of activation selected for the preparation of activated carbons affected the adsorption of VOCs and hence are factors to be considered in any adsorption process. The steam-activated, pecan shell carbon adsorbed more total VOCs than the other experimental carbons and had an adsorption profile similar to the two coconut shell-based commercial carbons, but had greater adsorption than the coal-based commercial carbon. All the carbons studied adsorbed benzene more effectively than the other organics. Pecan shell, steam-activated and acid-activated GACs showed higher adsorption of 1,1,1-trichloroethane than the other carbons studied. Multivariate analysis was conducted to group experimental carbons and commercial carbons based on their physical, chemical, and adsorptive properties. The results of the analysis conclude that steam-activated and acid-activated pecan shell carbons clustered together with coal-based and coconut shell-based commercial carbons, thus inferring that these experimental carbons could potentially be used as alternative sources for VOC adsorption in an aqueous environment.
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Affiliation(s)
- R R Bansode
- Department of Food Science, Louisiana State University, Agricultural Center, Food Science Building, Baton Rouge, LA 70808-4200, USA
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17
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Abstract
The present investigation was undertaken to evaluate the adsorption effectiveness of pecan shell-based granular activated carbons (GACs) in removing metal ions (Cu(2+), Pb(2+), Zn(2+)) commonly found in municipal and industrial wastewater. Pecan shells were activated by phosphoric acid, steam or carbon dioxide activation methods. Metal ion adsorption of shell-based GACs was compared to the metal ion adsorption of a commercial carbon, namely, Calgon's Filtrasorb 200. Adsorption experiments were conducted using solutions containing all three metal ions in order to investigate the competitive effects of the metal ions as would occur in contaminated wastewater. The results obtained from this study showed that acid-activated pecan shell carbon adsorbed more lead ion and zinc ion than any of the other carbons, especially at carbon doses of 0.2-1.0%. However, steam-activated pecan shell carbon adsorbed more copper ion than the other carbons, particularly using carbon doses above 0.2%. In general, Filtrasorb 200 and carbon dioxide-activated pecan shell carbons were poor metal ion adsorbents. The results indicate that acid- and steam-activated pecan shell-based GACs are effective metal ion adsorbents and can potentially replace typical coal-based GACs in treatment of metal contaminated wastewater.
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Affiliation(s)
- R R Bansode
- Department of Food Science, Louisiana State University Agricultural Center, Food Science Building, Baton Rouge, LA 70803, USA
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18
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Rao RM, Jo Y, Leers-Sucheta S, Bose HS, Miller WL, Azhar S, Stocco DM. Differential regulation of steroid hormone biosynthesis in R2C and MA-10 Leydig tumor cells: role of SR-B1-mediated selective cholesteryl ester transport. Biol Reprod 2003; 68:114-21. [PMID: 12493702 DOI: 10.1095/biolreprod.102.007518] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The rat R2C Leydig tumor cell line is constitutively steroidogenic in nature, while the mouse MA-10 Leydig tumor cell line synthesizes large amounts of steroids only in response to hormonal stimulation. Earlier studies showed abundant cAMP-independent steroid production and constitutive expression of steroidogenic acute regulatory (StAR) protein in R2C cells. The objective of the current study was to identify possible genetic alterations in the R2C cell line responsible for rendering it a constitutively steroidogenic cell line, especially those that might have altered its cholesterol homeostatic mechanisms. Measurement of the levels of cholesterol esters and free cholesterol, precursors for steroidogenesis, indicated that R2C mitochondria were fourfold enriched in free cholesterol content compared with MA-10 mitochondria. In addition to the previously demonstrated increased expression of StAR protein, we show that R2C cells possess marginally enhanced protein kinase A activity, exhibit higher capacity to take up extracellular cholesterol esters, and express much higher levels of scavenger receptor-type B class 1 (SR-B1) and hormone sensitive lipase (HSL). These observations suggest that the high level of steroid biosynthesis in R2C cells is a result of the constitutive expression of the components involved in the uptake of cholesterol esters (SR-B1), their conversion to free cholesterol (HSL), and its mobilization to the inner mitochondrial membrane (StAR).
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Affiliation(s)
- Rekha M Rao
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
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19
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Rao RM, Jo Y, Babb-Tarbox M, Syapin PJ, Stocco DM. Regulation of steroid hormone biosynthesis in R2C and MA-10 Leydig tumor cells: role of the cholesterol transfer proteins StAR and PBR. Endocr Res 2002; 28:387-94. [PMID: 12530640 DOI: 10.1081/erc-120016813] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The MA-10 mouse Leydig tumor cell line produces large amounts of steroids only in response to hormonal stimulation while the R2C rat Leydig tumor cell line is constitutively steroidogenic in nature. In an effort to uncover the potential reasons for constitutive steroidogenesis in R2C cells, we have recently shown that compared to MA-10 cells, R2C cells express much higher levels of the Scavenger Receptor Class B type 1 which results in a higher capacity for cholesteryl ester uptake through the selective uptake pathway. We also found an enhanced expression of Hormone Sensitive Lipase and the Steroidogenic Acute Regulatory protein in these cells and reasoned that they may further facilitate the conversion of cholesteryl esters to free cholesterol and its mobilization to the inner mitochondrial membrane, thus rendering them constitutively steroidogenic. Given the proposed role of the peripheral-type benzodiazepine receptor (PBR) in conferring a constitutively steroidogenic phenotype to the R2C cells, the current study was conducted to investigate the relationship between its expression in MA-10 and R2C cells and correlate it with the constitutive nature of R2C cell steroidogenesis. Our studies show that PBR expression as measured by PK 11195 ligand binding and Western analysis is much higher in MA-10 cells than R2C cells. We also determined that the affinity of ligand binding to the PBR is comparable in the two cell lines, suggesting that PBR is unlikely to be solely responsible for the constitutive nature of R2C cell steroidogenesis.
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Affiliation(s)
- Rekha M Rao
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
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20
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Abstract
Acute (24 h) and chronic (90 days) oral toxicity studies on Commiphora molmol (oleo-gum-resin) were carried out in mice. Dosages in acute study were 0.5, 1.0 and 3 g/kg, while in chronic study dosage was 100 mg/kg per day. All external morphological, biochemical and haematological changes, in addition to body and vital organ weights were recorded. There was no significant difference in mortality in acute or chronic treatment as compared to controls. At the end of the treatment, weight gain in the treated as well as control group was significant. There was a significant increase in weight of testes, caudae epididymides and seminal vesicles in C. molmol treated group. Biochemical studies revealed no differences in C. molmol treated animals, however, haematological studies revealed a significant increase in RBC and haemoglobin levels as compared to the control group. C. molmol failed to show any spermatotoxic effects.
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Affiliation(s)
- R M Rao
- Central Laboratory for Drug & Food Analysis, Ministry of Health, P.O. Box 59082, 11525, Riyadh, Saudi Arabia
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21
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Abstract
Placenta is a transient feto-maternal association that develops during mammalian pregnancies. Human placental tissue during the first trimester of pregnancy is an actively dividing and differentiating tissue, while near term, it represents a fully differentiated unit performing many life-sustaining functions for the fetus. Previous studies have demonstrated that the percentage of placental cells that undergo apoptosis is greater at full term as compared to the first trimester of pregnancy. In this study, we undertook a study aimed at gaining an insight into the kind of genes expressed in the two developmentally distinct stages of gestation ie, the first trimester and term using Differential Display RT-PCR. Cloning and sequencing of one of the differentially expressed cDNAs from term placental tissue revealed that it is a novel gene, referred to as T-18 in the text. In this study, we also examined the regulation of this gene during apoptosis in the human placenta. A model for analysis of placental apoptosis was established by incubating placental villi in serum-free culture medium. It was observed that apoptosis occurred rapidly following incubation of placental villi without tropic support, and the proposed free-radical scavenger, superoxide dismutase (SOD) suppressed apoptosis in the placenta. Interestingly, the levels of T-18 mRNA increased significantly during spontaneous induction of apoptosis and decreased when apoptosis was blocked by SOD. These data clearly suggest that there is a strong correlation between the expression of T-18 and placental apoptosis and that T-18, may play a significant role in this process. Furthermore, the establishment of a defined in vitro explant culture model should facilitate elucidation of factors, which regulate apoptosis in human placenta.
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Affiliation(s)
- R M Rao
- Department of Biochemistry, Indian Institute of Science, Bangalore.
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22
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Ramezanzadeh FM, Rao RM, Prinyawiwatkul W, Marshall WE, Windhauser M. Effects of microwave heat, packaging, and storage temperature on fatty acid and proximate compositions in rice bran. J Agric Food Chem 2000; 48:464-467. [PMID: 10691657 DOI: 10.1021/jf9909609] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of microwave heat, packaging methods, and storage temperatures on proximate and fatty acid compositions of rice bran during 16 weeks of storage was examined. Freshly milled raw rice bran was adjusted to 21% moisture content and microwave heated for 3 min. Raw and microwave-heated brans were packed in zipper-top bags and/or vacuum-sealed bags and stored at 4-5 and/or 25 degrees C for 16 weeks. The moisture content decreased significantly from an initial 8.4 to 6.4% in microwave-heated samples regardless of packaging methods and storage temperatures. Protein, fat, linoleic, and linolenic contents did not change significantly in all raw and microwave-heated samples during 16 weeks of storage. The microwave-heated rice bran packed in zipper-top bags can be stored at 4-5 degrees C for up to 16 weeks without adverse effect on proximate and fatty acid composition quality under the conditions employed in this study.
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Affiliation(s)
- F M Ramezanzadeh
- Department of Food Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803-4200, USA
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23
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Sparano JA, Hu P, Rao RM, Falkson CI, Wolff AC, Wood WC. Phase II trial of doxorubicin and paclitaxel plus granulocyte colony-stimulating factor in metastatic breast cancer: an Eastern Cooperative Oncology Group Study. J Clin Oncol 1999; 17:3828-34. [PMID: 10577856 DOI: 10.1200/jco.1999.17.12.3828] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Several groups have reported that the combination of doxorubicin plus paclitaxel given as a 3-hour intravenous (IV) infusion for up to eight cycles produces a high response rate (> 80%) and complete response rate (> 20%) in metastatic breast cancer, but is also complicated by a 20% incidence of congestive heart failure (CHF). The purpose of this phase II trial was to evaluate the antineoplastic activity of the regimen in a multi-institutional setting and to reduce the incidence of cardiotoxicity by limiting treatment to a maximum of six cycles. PATIENTS AND METHODS Fifty-two patients with advanced breast cancer received doxorubicin (60 mg/m(2) by IV injection) followed 15 minutes later by paclitaxel (200 mg/m(2) by IV infusion over 3 hours) every 3 weeks for four to six cycles. RESULTS Objective responses occurred in 25 of 48 assessable patients (52%; 95% confidence interval [CI], 38% to 66%), including four complete responses (8%; 95% CI, 0% to 16%). The median cumulative doxorubicin dose given was 240 mg/m(2) (range, 132 to 360 mg/m(2)). Eleven patients (21%) were documented as having a decrease in the LVEF below normal, including three patients (6%; 95% CI, 0% to 12%) who developed CHF. CONCLUSION The doxorubicin/paclitaxel regimen that we used is unlikely to produce an objective response rate of more than 70% and a complete response rate of more than 20% in patients with metastatic breast cancer, and proved to be excessively cardiotoxic for use in the adjuvant setting.
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Affiliation(s)
- J A Sparano
- Albert Einstein Comprehensive Cancer Center, Montefiore Medical Center, Bronx, NY 10461-2373, USA
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24
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Ramezanzadeh FM, Rao RM, Windhauser M, Prinyawiwatkul W, Marshall WE. Prevention of oxidative rancidity in rice bran during storage. J Agric Food Chem 1999; 47:2997-3000. [PMID: 10552599 DOI: 10.1021/jf981168v] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of microwave heat on lipoxygenase (LOX) activity in rice bran under various storage conditions was examined. Raw rice bran from the long-grain variety Lemont was adjusted to 21% moisture content and heated in a microwave oven at 850 W for 3 min. Raw and microwave-heated rice bran samples were packed in zipper-top bags or vacuum packs and stored at room temperature (25 degrees C) or in the refrigerator (4-5 degrees C) for 16 weeks. Samples were analyzed for LOX activity at 4-week intervals. LOX activity did not significantly change from its initial value at week 0 for zipper-top and vacuum-packed samples while stored at 4-5 degrees C for 12 weeks, but decreased at week 16. Vacuum packing did not show a significant impact on LOX activity during 16 weeks of storage. Microwave-heated samples stored in the refrigerator did not show significant change in LOX activity for up to 12 weeks but showed a significant (p < 0. 05) decrease at 16 weeks. Results showed that oxidative rancidity of rice bran could be prevented by microwave heating the samples, packing in zipper-top bags, and storing at 4-5 degrees C for up to 16 weeks.
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Affiliation(s)
- F M Ramezanzadeh
- Department of Food Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803, USA
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25
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Ramezanzadeh FM, Rao RM, Windhauser M, Prinyawiwatkul W, Tulley R, Marshall WE. Prevention of hydrolytic rancidity in rice bran during storage. J Agric Food Chem 1999; 47:3050-3052. [PMID: 10552606 DOI: 10.1021/jf981335r] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The effect of microwave heating, packaging, and storage temperature on the production of free fatty acids (FFA) in rice bran was examined. Freshly milled raw rice bran was adjusted to 21% moisture content and heated in a microwave oven at 850 W for 3 min. Raw and microwave-heated rice bran were packed in zipper-top bags or vacuum-sealed bags and stored at 4-5 or 25 degrees C for 16 weeks. FFA content of bran was measured at 4-week intervals. Total FFA increased rapidly over the 16-week period from the initial value of 2.5% in raw bran stored at 25 degrees C to 54.9% in vacuum bags and 48.1% in zipper-top bags. However, total FFA of raw bran stored at 4-5 degrees C increased at a slower rate from an initial value of 2. 5 to 25.4% in vacuum bags and 19.5% in zipper-top bags. After 16 weeks of storage, total FFA of microwave-heated bran stored at 25 degrees C increased from 2.8 to 6.9 and 5.2%, respectively, for samples stored in vacuum bags and zipper-top bags. Total FFA of microwave-heated samples stored at 4-5 degrees C did not change significantly with storage time. Results showed that hydrolytic rancidity of rice bran can be prevented by microwave heating and that the recommended storage condition for microwaved rice bran is 4-5 degrees C in zipper-top bags.
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Affiliation(s)
- F M Ramezanzadeh
- Department of Food Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803-4200, USA
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26
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Affiliation(s)
- R M Rao
- Central Laboratory for Drug and Food Analysis, MOH, Riyadh, Saudi Arabia
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27
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Ahmedna M, Prinyawiwatkul W, Rao RM. Solubilized wheat protein isolate: functional properties and potential food applications. J Agric Food Chem 1999; 47:1340-1345. [PMID: 10563977 DOI: 10.1021/jf981098s] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Solubility, foaming capacity/stability, water holding and fat absorption capacities, and emulsifying capacity/stability of a solubilized wheat protein isolate (SWPI) were compared with those of commercial protein, that is, sodium caseinate (NaCAS), dried egg white (DEW), nonfat dry milk (NFDM), and soy protein isolate (SPI). SWPI was highly soluble at pH 6.5-8.5. Foaming capacity of SWPI was superior to those of SPI, NFDM, and DEW, and its foaming stability was similar to those of the commercial proteins. Foaming properties of SWPI were greatly improved in the presence of 0.5% (w/v) CaCl(2). Water holding capacity of SWPI was greater than that of NaCAS, NFDM, and DEW, whereas its fat absorption capacity was comparable to that of SPI, NaCAS, and DEW. SWPI exhibited emulsifying properties similar to those of SPI. SWPI was incorporated at 5, 10, 15, or 20% into ice cream, chocolate chip cookies, banana nut muffins, and hamburger patties. Products containing <5% SWPI were acceptable to consumers.
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Affiliation(s)
- M Ahmedna
- Department of Food Science, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural Center, Baton Rouge 70803-4200, USA
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28
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Rao RM, Salem FA, Gleason-Jordan I. Antidiabetic effects of a dietary supplement "Pancreas Tonic". J Natl Med Assoc 1998; 90:614-8. [PMID: 9803726 PMCID: PMC2608368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Pancreas Tonic, a dietary supplement, contains plant products shown to possess hypoglycemic activity. This study investigated the effect of Pancreas Tonic on serum glucose, glycosylated hemoglobin, and pancreatic islet cell regeneration of rats. Results showed that body weights of three groups of rats were not significantly different from each other before the study period, and after the 12 week study, weights increased with nonsignificant difference among the groups. The diabetic group had significantly higher serum glucose levels compared with controls, and the diet-treated group had significantly lower serum glucose levels compared with the diabetic group. The diabetic group's glycosylated hemoglobin was significantly higher compared with the control group, and the diet-treated group had significantly lower glycosylated hemoglobin levels compared with the diabetic and control groups. Histological analysis of the pancreas showed a generalized reduction in size and number of islets in the diabetic group and regeneration of islet cells in the diet-treated group compared with the diabetic group. The diabetic group had a significant reduction in the number of cells compared with controls. The diet-treated group contained a significantly increased number of cells compared with the diabetic group. These data suggest that Pancreas Tonic induced an antidiabetic effect through pancreatic islet cell regeneration in experimental rats.
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Affiliation(s)
- R M Rao
- Department of Internal Medicine, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059, USA
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29
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Andrews LS, Ahmedna M, Grodner RM, Liuzzo JA, Murano PS, Murano EA, Rao RM, Shane S, Wilson PW. Food preservation using ionizing radiation. Rev Environ Contam Toxicol 1998; 154:1-53. [PMID: 9414630 DOI: 10.1007/978-1-4612-2208-8_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Irradiation processing has been researched extensively and is now in use worldwide for many food commodities. Irradiation has been successfully used to reduce pathogenic bacteria, eliminate parasites, decrease postharvest sprouting, and extend the shelf life of fresh perishable foods. Although food irradiation is widely accepted in world food markets, U.S. markets have been slower to accept the idea of irradiated food products. For fruits and vegetables, irradiation is not a cure for shelf life problems; cost and quality problems damage preclude its general use. It appears that the most likely use of irradiation in fruits and vegetables is as an insect control in those commodities for which there is no effective alternative method. For grains such as rice and wheat, irradiation has been used primarily to control insect infestation when insects have been shown to develop resistance to the traditional fumigation methods. Treatment of spices with irradiation doses of 10 kGy has proved to extend shelf life without causing significant changes in sensory or chemical quality. Higher doses that effectively sterilize spices, however, may cause undesirable chemical and sensorial changes. For meat, especially red meat, irradiation is considered a viable alternative in the effort to improve the safety of meat products. With time, the authors believe that economic realities and the technical superiority of irradiation for specific poultry products will lead to public acceptance of the process. Irradiation of seafood products is still being considered for approval by the USFDA, although it is currently used in Asian and European markets, especially for shrimp. It is our belief that scientifically based research in food irradiation and the positive results thereof will also prove economical in the twenty-first century. As we move to a more peaceful world with reduced threat of nuclear holocaust, these valid opinions will prevail and will overshadow the distortions and misinformation generated by the opponents of irradiation.
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Affiliation(s)
- L S Andrews
- Department of Food Science, Louisiana State University Agricultural Center, Baton Rouge 70803, USA
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Rao RM, Yan Y, Wu Y. Dietary calcium reduces blood pressure, parathyroid hormone, and platelet cytosolic calcium responses in spontaneously hypertensive rats. Am J Hypertens 1994; 7:1052-7. [PMID: 7702798 DOI: 10.1093/ajh/7.12.1052] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Dietary calcium effects on blood pressure, parathyroid hormone (PTH), and platelet cytosolic calcium concentrations were investigated. The dietary calcium (low, 0.2%; medium, 0.5%; and high, 2.0% wt/wt) was supplemented in spontaneously hypertensive rats from 6 through 22 weeks of age. Mean systolic blood pressure was decreased by age 12 weeks with calcium supplementation (low, 227 +/- 6 mm Hg; medium, 211 +/- 6 mm Hg; and high, 182 +/- 7 mm Hg; P < .001). By the 10th week of age, the low calcium group had significantly (P < .05) more elevated (44 +/- 2.3 pg/ml) plasma PTH compared with the high calcium-supplemented group (15 +/- 4.5 pg/mL). Regression analysis showed a significant (P < .001) positive correlation (r = 0.3) between systolic blood pressure and PTH. The platelet cytosolic calcium concentration was determined using the fura-2 method. The basal calcium was 134 +/- 5.5 nmol/L for the low calcium group and thrombin increased to 228 +/- 8 nmol/L (P < .0001; +70% change). The normal calcium group had 202 +/- 8 nmol/L; thrombin increased to 239 +/- 10 nmol/L (P < .0026; +19% change). The high calcium group had basal levels 145 +/- 7 nmol/L, with thrombin stimulating to 212 +/- 8 nmol/L (P < .0001; +46% change). Although thrombin increased platelet cytosolic calcium concentration in all groups, normal and high dietary calcium groups had smaller percentage increases (51% and 24% lesser, respectively) compared with the low dietary calcium group.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R M Rao
- Calcium Hypertension Research Lab, Charles R. Drew University of Medicine and Science, Los Angeles, California 90059
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32
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Choi HC, Rao RM, Mihill AG, Kakar S, Poliakoff ED, Wang K, McKoy V. Energy dependence of photoion rotational distributions of N2 and CO. Phys Rev Lett 1994; 72:44-47. [PMID: 10055562 DOI: 10.1103/physrevlett.72.44] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Rao RM, Reddy GP, Grim CE. Relative role of genes and environment on BP: twin studies in Madras, India. J Hum Hypertens 1993; 7:451-5. [PMID: 8263886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This study was conducted to test the feasibility of the twin research model in a developing country with diverse cultures and to understand the relative influence of genetic and environmental factors on BP variation among South Indians. This was a cross-sectional twin study of volunteers using a two-by-two factorial design for the analysis of quantitative traits. The factors were twin type (monozygotic and dizygotic) and sex (male and female). The study was conducted in Madras. Twenty-four pairs of twins were contacted for participation in the project. Of the 24 pairs we contacted, 91% (20) actually participated in our study. Among 20 sets we studied, 10 (50%) are males and 10 (50%) are females with an average age of 23 years. The mean SBP of this volunteer twin population was 115.18 +/- 1.27 mmHg and DBP was 68.53 +/- 1.41 mmHg. Analysis of dietary habits (vegetarian/nonvegetarian) showed that BP was greater (118.26 +/- 2.29/71.88 +/- 2.34 mmHg) in vegetarian twins than nonvegetarians (112.28 +/- 1.42/66.2 +/- 1.90 mmHg). Also a positive correlation between urinary excretion of calcium and BP was observed. The present study demonstrates that epidemiological research in a developing country like India is feasible and economical, using the twin research methodology. As observed in other populations, the major source of BP variation in the population appears to be predominantly under genetic control.
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Affiliation(s)
- R M Rao
- Charles R. Drew University of Medicine and Science, Los Angeles, California 90059
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Rao RM, Sekhar NC, Daniel SM. Retained foreign body in orbit with intra cranial extension. Indian J Ophthalmol 1993; 41:86-7. [PMID: 8262611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Affiliation(s)
- R M Rao
- OEU Institute of Ophthalmology, Kasturba Hospital, Manipal
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Abstract
The conformational preference of A and B rings in four differently functionalized bromosubstituted 4-en-3-one steroids is studied by concerted application of high-resolution one- and two-dimensional nuclear magnetic resonance (NMR) techniques, such as homonuclear and heteronuclear correlated spectroscopy, transient and steady-state nOe spectroscopy, temperature-dependent chemical chemical shift variation, and application of a modified Karplus equation. The steroids studied include 6 beta-bromocholest-4-en-3-one (3), 4,6 beta-dibromocholest-1,4-dien-3-one (2), 2 alpha,4,6 beta-tribromocholest-4-en-3-one (1), and (25R)-2 alpha,6 beta-dibromospirost-4-en-3-one (4). Steroids 1-4 were prepared by either acid-catalyzed or free-radical bromination from appropriate 4-en-3-one steroid. The study has yielded an insight into the factors responsible for conformational preferences of the A and B rings of these bromosubstituted steroids. Bromosubstitution at the 2 alpha position is responsible for the inversion of the A ring to inverted 1 beta,2 alpha-halfchair conformation. The electronic interaction between 4-bromine and carbonyl oxygen distorts the A-ring conformation further. Inversion of the A ring has a concomitant effect of distortion in the chair form of the B ring. Conformational preferences of A and B rings are not found to be influenced by transmission effect of a side chain or oxygenated ring system. Temperature-dependent NMR studies indicate the reduced conformational flexibility of the A ring for 2 alpha-bromosubstituted steroids. Complete assignment of the 13C and 1H resonances of two of the steroids studied (3 and 4) is presented.
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Affiliation(s)
- R Sridharan
- Department of Chemistry, Indian Institute of Technology, Powai, Bombay
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Ramani A, Raja A, Ravi TS, Kundaje GN, Rao RM, Rao PN. Idiopathic thrombocytopenic purpura mimicking intracranial tumour. J Indian Med Assoc 1989; 87:239-40. [PMID: 2630602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Affiliation(s)
- R M Rao
- Division of Nephrology and Hypertension, Oregon Health Sciences University, Portland
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Chayovan S, Rao RM, Liuzzo JA, Khan MA. Fatty acids and sensory acceptance of a dietary sodium-potassium fish sauce. J Agric Food Chem 1983; 31:14-17. [PMID: 6826910 DOI: 10.1021/jf00115a004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Abstract
A review of the nutritional quality of foods served by selected types of foodservices reveals the lack of information in this area. The foodservice industry is growing rapidly with new technological innovations and management practices. However, little effort has been made toward the nutrient quality of foods served by important foodservice operations. Foodservice operations are discussed from the institutional and commercial point of view. Under the institutional type, foodservices in nursing homes, hospitals, schools, colleges, and universities are discussed. Fast foodservices are primarily focused under commercial type of foodservices. Other discussions are based on nutrient contents of foods prepared in quantities. Lack of data pertaining to nutrient content of foods served by foodservice operations is evident.
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Rajalakshmi S, Rao RM, Sarma DS. Carcinogen-DNA interaction: differential effects of distamycin-a and spermine on the formation of 7-methylguanine in DNA by N-methyl-N-nitrosourea, methylmethanesulfonate, and dimethylsulfate. Teratog Carcinog Mutagen 1981; 1:97-104. [PMID: 6119804 DOI: 10.1002/tcm.1770010110] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Experiments were designed to determine whether DNA conformation and sequence play any role in its methylation by N-methyl-N-nitrosourea, methylmethanesulfonate, and dimethylsulfate, agents that are known to methylate DNA by different mechanisms but yield 7-methylguanine as the major product. The approach taken was to bind ligands to DNA that interact with it stereospecifically and to study their effect on the formation of 7-methylguanine by the three methylating agents. The results indicate that both distamycin A and spermine shielded the formation of 7-methylguanine in vitro in rat liver DNA by N-methyl-N-nitrosourea but not by methylmethanesulfonate or dimethylsulfate; they did not, however, protect 2-deoxyguanylic acid against methylation by N-methyl-N-nitrosourea. Based on the mechanism by which the methylating agents and the ligands react with DNA, these results are interpreted to suggest that 1) guanines methylatable at the N-7 position by N-methyl-N-nitrosourea are located at, or close to, the binding sites of the ligands, probably the A-T-rich regions, and those methylatable by methylmethanesulfonate and dimethylsulfate are distal to these regions, and/or 2) the conformation DNA assumes in the presence of distamycin A or spermine permits methylation by methylmethanesulfonate and dimethylsulfate but not by N-methyl-N-nitrosourea. The study implicates DNA structure and/or its sequences in carcinogen-DNA interaction.
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