tbuckley/cabot-search huggingface dataset:
An alternative approach to medical genetics based on modern evolutionary biology. Part 5: epigenetics and genomics
Authors: Frank P Ryan
Journal: Journal of the Royal Society of Medicine (2009)

The concept of epigenetics was pioneered in 1939 by the Edinburgh-based developmental biologist, Conrad H Waddington1 to encompass all aspects of embryological development, but today the term is more specifically applied to the study of hereditable change in the expression of genes without change in DNA sequences. In effect this amounts to a range of non-DNA-based mechanisms that control gene transcription.2 These epigenetic mechanisms may be influenced by environmental factors, and this has potential therapeutic implications. When epigenetic mechanisms are inherited, this has evolutionary significance.3,4 Genomic duplication, particularly the whole genomic duplications that result from hybridogenesis and polyploidy, also has evolutionary and medical implications. In this final review, we shall examine the evolutionary implications of epigenetics and genomic duplications for human evolution, and the potential such understanding offers to medicine.
Cd1, Tuberculosis, and the Evolution of Major Histocompatibility Complex Molecules
Authors: Kanade Shinkai, Richard M. Locksley
Journal: The Journal of Experimental Medicine (2000)

Although the role of class I and class II MHC in adaptive immunity against microbial pathogens is clear, the participation of nonpolymorphic MHC molecules in host defense remains less well defined. Roles for murine class I MHC molecule Qa-2 and class Ib molecule H2-M3 have been suggested ([1][1])([2
Alpha-adrenergic receptor stimulation during simulated ischemia and reperfusion in canine cardiac Purkinje fibers.
Authors: M Hamra, M R Rosen
Journal: Circulation (1988)

We studied the effects of alpha-adrenergic receptor stimulation and calcium on automaticity of isolated canine Purkinje fibers during simulated ischemia and reperfusion. Ischemia included acidosis (pH 6.7), hypoxia (PO2 = 10-25 mm Hg), hyperkalemia (10 mM K+), and either normal or elevated [Ca2+]o (2.7 or 10.8 mM). Control automatic rate and maximum diastolic potential were 18 +/- 2 beats/min and -94 +/- 1 mV, respectively. Simulated ischemia led to depolarization (to -60 +/- 1 mV), cessation of normal automaticity, and in 21% of fibers, bursts of an abnormal automatic rhythm. Phenylephrine, 5 X 10(-8) M, increased the incidence of the automatic rhythm during ischemia to 44%; this effect was blocked by prazosin but not by propranolol. During reperfusion after simulated ischemia at 2.7 mM [Ca2+]o, automatic rhythm and maximum diastolic potential returned toward control values; after simulated ischemia at 10.8 mM [Ca2+]o, automatic rates were greater than those seen after normal Ca2+ ischemia and were associated with sustained membrane depolarization. Phenylephrine (5 X 10(-8) M) at 2.7 mM [Ca2+]o rapidly restored membrane potential during reperfusion, an effect that was blocked by prazosin. At 10.8 mM [Ca2+]o, phenylephrine also restored membrane potential during reperfusion and blunted the increase in reperfusion rate induced by high [Ca2+]o alone. These effects were blocked by propranolol but not by prazosin. Our results show that the effects of phenylephrine on automatic rhythms during simulated ischemia are blocked by alpha-adrenergic receptor antagonists and that rhythms occurring during reperfusion have alpha- and beta-adrenergic receptor components.
Induction Hedgehog pathway inhibition followed by combined‐modality radiotherapy for basal cell carcinoma
Authors: D.R. Raleigh, A. Algazi, S.T. Arron, I.M. Neuhaus, S.S. Yom
Journal: British Journal of Dermatology (2015)

Basal cell carcinoma (BCC), the most common cancer in the U.S.A., is treated primarily with local excision. In some cases, lesion size, location or extent prevent complete resection. Locally advanced BCC responds to systemic therapy with the Hedgehog pathway inhibitor vismodegib, but withdrawal of treatment may result in disease relapse. Here we present a case of locally advanced auricular BCC treated with induction vismodegib and radiation, resulting in durable local control and an acceptable level of acute toxicity.
CYTOLOGICAL ABERRATIONS IN CULTURES OF "NORMAL" MONKEY KIDNEY EPITHELIAL CELLS
Authors: Ruth Kleinfeld, Joseph L. Melnick
Journal: The Journal of Experimental Medicine (1958)

A cytological study was made of short term primary cultures of monkey kidney epithelial cells grown in serum-containing (M-H) and synthetic (SM-2) media. The mitotic activity of the cultures reached a peak 3 to 5 days after seeding, and rapidly declined if the medium was not changed. With replenishment at 48 hour intervals a high mitotic rate was maintained through the 8th day. Cultures subjected to a glycine- and glucose-deficient medium showed a sharp decline in mitotic activity within 24 hours. When such cultures were replenished a burst of mitotic activity occurred 20 to 30 hours later. Mitotic aberrations such as multipolar spindles, anomalous spindles with scattered chromosomes, lagging or precocious movement of chromosomes, chromosome fragments, and chromosome bridges were found in all cultures ranging from 16 to 40 per cent of the dividing cells. Non-mitotic aberrations such as giant nuclei, multinucleate cells, nuclear fragmentation, micronuclei, nuclear inclusions, and phagocytosis were found in approximately 3 to 7 per cent of the non-dividing cell population. The frequency and types of mitotic abnormalities were generally independent of the medium used and the mitotic index of the cultures.
Funding Patient-Reported Outcomes in Cancer Clinical Trials
Authors: Carol M. Moinpour, Andrea M. Denicoff, Deborah Watkins Bruner, Alice B. Kornblith, Stephanie R. Land, Ann O'Mara, Edward Trimble
Journal: Journal of Clinical Oncology (2007)

We surveyed four cooperative groups to identify current funding sources for the collection and analysis effort associated with the inclusion of patient-reported outcome (PRO) data in cancer clinical trials. Survey questions included what proportion of staff effort was funded through the Cancer Therapy Evaluation Program (CTEP) and the Community Clinical Oncology Program (CCOP) grants. In addition, the groups were asked to what extent outside funding was solicited to cover an underfunded PRO effort (eg, the pharmaceutical industry, foundations, or National Institutes of Health grants). All four groups noted the challenge of making limited resources cover a number of trial responsibilities. PRO effort is usually bundled with effort required for all clinical trial data. There is variation in the use of the CTEP and CCOP grants to fund PRO research. The groups differed with respect to both the types and amount of outside funding used. This survey focused on funding sources for the conduct of PRO research in cooperative group trials; it did not assess the specific cost components associated with collecting and analyzing these data. In general, the costs for conducting PRO research have been bundled with other study costs because in most cases, the PRO has been considered an integral component of the trial. However, these data also suggest that PRO research has required the use of outside funding sources in the four surveyed cooperative groups and that PRO economic issues require attention if we are to continue the inclusion of these outcomes in cancer clinical trials.
Topical Sonic Hedgehog Gene Therapy Accelerates Wound Healing in Diabetes by Enhancing Endothelial Progenitor Cell–Mediated Microvascular Remodeling
Authors: Jun Asai, Hideya Takenaka, Kengo F. Kusano, Masaaki Ii, Corinne Luedemann, Cynthia Curry, Elizabeth Eaton, Atsushi Iwakura, Yoshiaki Tsutsumi, Hiromichi Hamada, Saburo Kishimoto, Tina Thorne, Raj Kishore, Douglas W. Losordo
Journal: Circulation (2006)

Background— Sonic hedgehog (Shh) is a prototypical morphogen known to regulate epithelial-mesenchymal interaction during embryonic development. Recent observations indicate that exogenous administration of Shh can induce angiogenesis and may accelerate repair of ischemic myocardium and skeletal muscle. Because angiogenesis plays a pivotal role in wound repair, we hypothesized that activation of the hedgehog pathway may promote a favorable effect on microvascular remodeling during cutaneous wound healing and thereby accelerate wound closure. Because diabetes is associated with impaired wound healing, we tested this hypothesis in a diabetic model of cutaneous wound repair. Methods and Results— In Ptc1-LacZ mice, cutaneous injury resulted in LacZ expression, indicating that expression of the Shh receptor Patched was induced and therefore that the Shh signaling pathway was intact postnatally and upregulated in the process of wound repair. In diabetic mice, topical gene therapy with the use of naked DNA encoding for Shh resulted in significant local gene expression and acceleration of wound recovery. The acceleration in wound healing was notable for increased wound vascularity. In bone marrow transplantation models, the enhanced vascularity of the wound was shown to be mediated, at least in part, by enhanced recruitment of bone marrow–derived endothelial progenitor cells. In vitro, Shh promoted production of angiogenic cytokines from fibroblasts as well as proliferation of dermal fibroblasts. Furthermore, Shh directly promoted endothelial progenitor cell proliferation, migration, adhesion, and tube formation. Conclusions— These findings suggest that a simple strategy of topically applied Shh gene therapy may have significant therapeutic potential for enhanced wound healing in patients with impaired microcirculation such as occurs in diabetes. (Circulation. 2006;113:2413-2424.)
First Evidence That γ-Tocotrienol Inhibits the Growth of Human Gastric Cancer and Chemosensitizes It to Capecitabine in a Xenograft Mouse Model through the Modulation of NF-κB Pathway
Authors: Kanjoormana A. Manu, Muthu K. Shanmugam, Lalitha Ramachandran, Feng Li, Chee Wai Fong, Alan Prem Kumar, Patrick Tan, Gautam Sethi
Journal: Clinical Cancer Research (2012)

Because of poor prognosis and development of resistance against chemotherapeutic drugs, the existing treatment modalities for gastric cancer are ineffective. Hence, novel agents that are safe and effective are urgently needed. Whether γ-tocotrienol can sensitize gastric cancer to capecitabine in vitro and in a xenograft mouse model was investigated.The effect of γ-tocotrienol on proliferation of gastric cancer cell lines was examined by mitochondrial dye uptake assay, apoptosis by esterase staining, NF-κB activation by DNA-binding assay, and gene expression by Western blotting. The effect of γ-tocotrienol on the growth and chemosensitization was also examined in subcutaneously implanted tumors in nude mice.γ-Tocotrienol inhibited the proliferation of various gastric cancer cell lines, potentiated the apoptotic effects of capecitabine, inhibited the constitutive activation of NF-κB, and suppressed the NF-κB-regulated expression of COX-2, cyclin D1, Bcl-2, CXCR4, VEGF, and matrix metalloproteinase-9 (MMP-9). In a xenograft model of human gastric cancer in nude mice, we found that administration of γ-tocotrienol alone (1 mg/kg body weight, intraperitoneally 3 times/wk) significantly suppressed the growth of the tumor and this effect was further enhanced by capecitabine. Both the markers of proliferation index Ki-67 and for microvessel density CD31 were downregulated in tumor tissue by the combination of capecitabine and γ-tocotrienol. As compared with vehicle control, γ-tocotrienol also suppressed the NF-κB activation and the expression of cyclin D1, COX-2, intercellular adhesion molecule-1 (ICAM-1), MMP-9, survivin, Bcl-xL, and XIAP.Overall our results show that γ-tocotrienol can potentiate the effects of capecitabine through suppression of NF-κB-regulated markers of proliferation, invasion, angiogenesis, and metastasis.
Effect of ethanol on rat fetal hepatocytes: Studies on cell replication, lipid peroxidation and glutathione
Authors: Bheemappa G. Devi, George I. Henderson, Teri A. Frosto, Steven Schenker
Journal: Hepatology (1993)

Studies have shown that ethanol at moderate concentrations inhibits epidermal growth factor-dependent replication of fetal rat hepatocytes in culture. This may account for the growth/development impairment associated with fetal alcohol syndrome and decreased liver regeneration in alcoholic liver disease. In this study, we further define the mechanism(s) of the negative impact of ethanol on fetal rat hepatocytes and provide evidence that ethanol-induced injury to these cells is associated with membrane damage caused by lipid peroxidation, altered cell glutathione homeostasis and deranged mitochondrial structure and function. Exposure of fetal rat hepatocyte replication to ethanol (2 mg/ml) promptly resulted in blockade of replication, as indicated by a 40% reduction in DNA synthesis (p < 0.05). Assessment of cell injury on the basis of lactate dehydrogenase and ALT leakage indicated a statistically significant but not appreciable effect, whereas 51Cr leakage was more substantially increased (p < 0.05). Within 6 hr of ethanol exposure, superoxide radical levels increased more than twofold (p < 0.05). We noted a 56% increase in levels of diene conjugates, a 131% increase in malonaldehyde concentration and a 66% increase in fluorescent products of lipid peroxidation (all p < 0.05). Glutathione levels were decreased to 47% below control values (p < 0.05). Electron microscopic studies illustrated a slight disruption of mitochondrial structure (enlargement of mitochondria and dilation of cristae). This disruption was accompanied by mitochondrial swelling (increased permeability), altered mitochondrial membrane potential (a 16% decrease in rhodamine uptake), a 28% decrease in succinate dehydrogenase activity and a 30% decrease in cellular ATP level (p < 0.05). Pretreatment of fetal rat hepatocytes with 0.1 mmol/L N-acetylcysteine or S-adenosylmethionine for 24 hr prevented the ethanol-induced reduction of ATP and glutathione levels, essentially restored cell replication, ameliorated 51Cr leakage and decreased malonaldehyde and diene conjugate levels to 41% to 65% and 25% above control values, respectively. Pretreatment with 0.1 mmol/L vitamin E fully normalized malonaldehyde and diene conjugate levels and 51Cr leakage but failed to improve ATP levels or to increase significantly cell replication and glutathione levels. Concomitant administration of glutathione precursors with ethanol, rather than pretreatment, did not alter the impaired cell replication. Thus our data underscore the importance of cellular glutathione and ATP in preventing ethanol-induced decreases in fetal cell replication and suggest that alleviation of cellular lipid peroxidation alone is not sufficient to prevent this abnormality in fetal rat hepatocyte function.
Corticotropin-releasing hormone links pituitary adrenocorticotropin gene expression and release during adrenal insufficiency
Authors: Louis J. Muglia, Lauren Jacobson, Christina Luedke, Sherri K. Vogt, Michele L. Schaefer, Pieter Dikkes, Shoko Fukuda, Yoko Sakai, Toshihiro Suda, Joseph A. Majzoub
Journal: Journal of Clinical Investigation (2000)

Corticotropin-releasing hormone (CRH)–deficient (KO) mice provide a unique system to define the role of CRH in regulation of the hypothalamic-pituitary-adrenal (HPA) axis. Despite several manifestations of chronic glucocorticoid insufficiency, basal pituitary proopiomelanocortin (POMC) mRNA, adrenocorticotrophic hormone (ACTH) peptide content within the pituitary, and plasma ACTH concentrations are not elevated in CRH KO mice. The normal POMC mRNA content in KO mice is dependent upon residual glucocorticoid secretion, as it increases in both KO and WT mice after adrenalectomy; this increase is reversed by glucocorticoid, but not aldosterone, replacement. However, the normal plasma levels of ACTH in CRH KO mice are not dependent upon residual glucocorticoid secretion, because, after adrenalectomy, these levels do not undergo the normal increase seen in KO mice despite the increase in POMC mRNA content. Administration of CRH restores ACTH secretion to its expected high level in adrenalectomized CRH KO mice. Thus, in adrenal insufficiency, loss of glucocorticoid feedback by itself can increase POMC gene expression in the pituitary; but CRH action is essential for this to result in increased secretion of ACTH. This may explain why, after withdrawal of chronic glucocorticoid treatment, reactivation of CRH secretion is a necessary prerequisite for recovery from suppression of the HPA axis.
Emerging patterns of genetic overlap across autoimmune disorders
Authors: Corinne Richard-Miceli, Lindsey A Criswell
Journal: Genome Medicine (2012)

Most of the recently identified autoimmunity loci are shared among multiple autoimmune diseases. The pattern of genetic association with autoimmune phenotypes varies, suggesting that certain subgroups of autoimmune diseases are likely to share etiological similarities and underlying mechanisms of disease. In this review, we summarize the major findings from recent studies that have sought to refine genotype-phenotype associations in autoimmune disease by identifying both shared and distinct autoimmunity loci. More specifically, we focus on information from recent genome-wide association studies of rheumatoid arthritis, ankylosing spondylitis, celiac disease, multiple sclerosis, systemic lupus erythematosus, type 1 diabetes and inflammatory bowel disease. Additional work in this area is warranted given both the opportunity it provides to elucidate pathogenic mechanisms in autoimmunity and its potential to inform the development of improved diagnostic and therapeutic tools for this group on complex human disorders.
Chronic Active Hepatitis and Associated Liver Tumors in Mice Caused by a Presistent Bacterial Infection With a Novel Helicobacter Species
Authors: J. M. Ward, J. G. Fox, M. R. Anver, D. C. Haines, C. V. George, M. J. Collins, P. L. Gorelick, K. Nagashima, M. A. Gonda, R. V. Gilden, J. G. Tully, R. J. Russell, R. E. Benvensite, B. J. Paster, F. E. Dewhirst, J. C. Donovan, L. M. Anderson, J. M. Rice
Journal: JNCI Journal of the National Cancer Institute (1994)

In the autumn of 1992, a novel form of chronic, active hepatitis of unknown etiology was discovered in mice at the National Cancer Institute-Frederick Cancer Research and Development Center (NCI-FCRDC), Frederick, Md. A high incidence of hepatocellular tumors occurred in affected animals. The disease entity was originally identified in A/JCr mice that were untreated controls in a long-term toxicologic study.Our original purpose was to determine the origin and etiology of the chronic hepatitis and to quantify its association with hepatocellular tumors in mice of low liver tumor incidence strains. After a helical microorganism was discovered in hepatic parenchyma of diseased mice, we undertook characterization of the organism and investigation of its relationship to the disease process.Hepatic histopathology of many strains of mice and rats, as well as guinea pigs and Syrian hamsters, in our research and animal production facilities was reviewed. Steiner's modification of the Warthin-Starry stain and transmission electron microscopy were used to identify bacteria in the liver. We transmitted the hepatitis with liver suspensions from affected mice and by inoculation with bacterial cultures. Bacteria were cultivated on blood agar plates maintained under anaerobic or microaerophilic conditions and characterized morphologically, biochemically, and by 16S rRNA sequence.We report here the isolation of a new species of Helicobacter (provisionally designated Helicobacter hepaticus sp. nov.) that selectively and persistently colonizes the hepatic bile canaliculi of mice (and possibly the intrahepatic biliary system and large bowel), causing a morphologically distinctive pattern of chronic, active hepatitis and associated with a high incidence of hepatocellular neoplasms in infected animals.The novel Helicobacter is a likely candidate for the etiology of hepatocellular tumors in our mice. The Helicobacter-associated chronic active hepatitis represents a new model to study mechanisms of carcinogenesis by this genus of bacteria.Adenocarcinoma of the stomach, the second most prevalent of all human malignancies world-wide, is associated with infection at an early age with Helicobacter pylori. Infection leads to several distinctive forms of gastritis, including chronic atrophic gastritis, which is a precursor of adenocarcinoma. H. hepaticus infection in mice constitutes the only other parallel association between a persistent bacterial infection and tumor development known to exist naturally. Study of the H. hepaticus syndrome of chronic active hepatitis and liver tumors in mice may yield insights into the role of H. pylori in human stomach cancer and gastric lymphoma.
Cancer Stem Cells: Distinct Entities or Dynamically Regulated Phenotypes?
Authors: Yunqing Li, John Laterra
Journal: Cancer Research (2012)

Abstract The origins of tumor-propagating neoplastic stem-like cells [cancer stem cells (CSC)] and their relationship to the bulk population of tumor cells that lack stem-like tumor-propagating features (i.e., transit-amplifying cancer progenitor cells) remain unclear. Recent findings from multiple laboratories show that cancer progenitor cells have the capacity to dedifferentiate and acquire a stem-like phenotype in response to either genetic manipulation or environmental cues. These findings suggest that CSCs and relatively differentiated progenitors coexist in dynamic equilibrium and are subject to bidirectional conversion. In this review, we discuss emerging concepts regarding the stem-like phenotype, its acquisition by cancer progenitor cells, and the molecular mechanisms involved. Understanding the dynamic equilibrium between CSCs and cancer progenitor cells is critical for the development of therapeutic strategies to deplete tumors of their tumor-propagating and treatment-resistant cell subpopulations. Cancer Res; 72(3); 576–80. ©2012 AACR.
Identification of Tyrosinase-related Protein 2 as a Tumor Rejection Antigen for the B16 Melanoma
Authors: Matthew B. Bloom, Donna Perry-Lalley, Paul F. Robbins, Yong Li, Mona El-Gamil, Steven A. Rosenberg, James C. Yang
Journal: The Journal of Experimental Medicine (1997)

Recently, major advances have been made in the identification of antigens from human melanoma which are recognized by T cells. In spite of this, little is known about the optimal ways to use these antigens to treat patients with cancer. Progress in this area is likely to require accurate preclinical animal models, but the availability of such models has lagged behind developments in human tumor immunology. Whereas many of the identified human melanoma antigens are normal tissue differentiation proteins, analogous murine tumor antigens have not yet been identified. In this paper we identify a normal tissue differentiation antigen, tyrosinaserelated protein 2 (TRP-2), expressed by the murine B16 melanoma which was found by screening a cDNA library from B16 with tumor-reactive cytotoxic T lymphocytes (CTL). A peptide conforming to the predicted MHC class I H2-Kb binding motif, TRP-2181-188, was identified as the major reactive epitope within TRP-2 recognized by these anti-B16 CTLs. By site-directed mutagenesis, it was shown that alteration of this epitope eliminated recognition of TRP-2. It was further demonstrated that a CTL line raised from splenocytes by repeated stimulation in vitro with this peptide could recognize B16 tumor and was therapeutic against 3-d-old established pulmonary metastases. The use of TRP-2 in a preclinical model of tumor immunotherapy may be helpful in suggesting optimal vaccination strategies for cancer therapy in patients.