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Turesky TK, Sanfilippo J, Zuk J, Ahtam B, Gagoski B, Lee A, Garrisi K, Dunstan J, Carruthers C, Vanderauwera J, Yu X, Gaab N. Home language and literacy environment and its relationship to socioeconomic status and white matter structure in infancy. Brain Struct Funct 2022; 227:2633-2645. [PMID: 36076111 PMCID: PMC9922094 DOI: 10.1007/s00429-022-02560-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 08/24/2022] [Indexed: 01/25/2023]
Abstract
The home language and literacy environment (HLLE) in infancy has been associated with subsequent pre-literacy skill development and HLLE at preschool-age has been shown to correlate with white matter organization in tracts that subserve pre-reading and reading skills. Furthermore, childhood socioeconomic status (SES) has been linked with both HLLE and white matter organization. It is important to understand whether the relationships between environmental factors such as HLLE and SES and white matter organization can be detected as early as infancy, as this period is characterized by rapid brain development that may make white matter pathways particularly susceptible to these early experiences. Here, we hypothesized that HLLE (1) relates to white matter organization in pre-reading and reading-related tracts in infants, and (2) mediates a link between SES and white matter organization. To test these hypotheses, infants (mean age: 8.6 ± 2.3 months, N = 38) underwent diffusion-weighted imaging MRI during natural sleep. Image processing was performed with an infant-specific pipeline and fractional anisotropy (FA) was estimated from the arcuate fasciculus (AF) and superior longitudinal fasciculus (SLF) bilaterally using the baby automated fiber quantification method. HLLE was measured with the Reading subscale of the StimQ (StimQ-Reading) and SES was measured with years of maternal education. Self-reported maternal reading ability was also quantified and applied to our statistical models as a proxy for confounding genetic effects. StimQ-Reading positively correlated with FA in left AF and to maternal education, but did not mediate the relationship between them. Taken together, these findings underscore the importance of considering HLLE from the start of life and may inform novel prevention and intervention strategies to support developing infants during a period of heightened brain plasticity.
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Affiliation(s)
- Ted K Turesky
- Harvard Graduate School of Education, Cambridge, MA, USA.
- Harvard Medical School, Boston, MA, USA.
| | - Joseph Sanfilippo
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, USA
- School of Medicine, Queen's University, Kingston, ON, Canada
| | | | - Banu Ahtam
- Harvard Medical School, Boston, MA, USA
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | - Borjan Gagoski
- Harvard Medical School, Boston, MA, USA
- Fetal-Neonatal Neuroimaging & Developmental Science Center, Division of Newborn Medicine, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | - Ally Lee
- Harvard Graduate School of Education, Cambridge, MA, USA
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Kathryn Garrisi
- Harvard Graduate School of Education, Cambridge, MA, USA
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Jade Dunstan
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Clarisa Carruthers
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Jolijn Vanderauwera
- Psychological Sciences Research Institute, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
- Institute of Neuroscience, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Xi Yu
- Beijing Normal University, Beijing, China
| | - Nadine Gaab
- Harvard Graduate School of Education, Cambridge, MA, USA
- Harvard Medical School, Boston, MA, USA
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Yu X, Ferradal S, Dunstan J, Carruthers C, Sanfilippo J, Zuk J, Zöllei L, Gagoski B, Ou Y, Grant PE, Gaab N. Patterns of Neural Functional Connectivity in Infants at Familial Risk of Developmental Dyslexia. JAMA Netw Open 2022; 5:e2236102. [PMID: 36301547 PMCID: PMC9614583 DOI: 10.1001/jamanetworkopen.2022.36102] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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] [Received: 02/27/2022] [Accepted: 08/23/2022] [Indexed: 11/14/2022] Open
Abstract
Importance Developmental dyslexia is a heritable learning disability affecting 7% to 10% of the general population and can have detrimental impacts on mental health and vocational potential. Individuals with dyslexia show altered functional organization of the language and reading neural networks; however, it remains unknown how early in life these neural network alterations might emerge. Objective To determine whether the early emergence of large-scale neural functional connectivity (FC) underlying long-term language and reading development is altered in infants with a familial history of dyslexia (FHD). Design, Setting, and Participants This cohort study included infants recruited at Boston Children's Hospital between May 2011 and February 2019. Participants underwent structural and resting-state functional magnetic resonance imaging in the Department of Radiology at Boston Children's Hospital. Infants with FHD were matched with infants without FHD based on age and sex. Data were analyzed from April 2019 to June 2021. Exposures FHD was defined as having at least 1 first-degree relative with a dyslexia diagnosis or documented reading difficulties. Main Outcomes and Measures Whole-brain FC patterns associated with 20 predefined cerebral regions important for long-term language and reading development were computed for each infant. Multivariate pattern analyses were applied to identify specific FC patterns that differentiated between infants with vs without FHD. For classification performance estimates, 99% CIs were calculated as the classification accuracy minus chance level. Results A total of 98 infants (mean [SD] age, 8.5 [2.3] months; 51 [52.0%] girls) were analyzed, including 35 infants with FHD and 63 infants without FHD. Multivariate pattern analyses identified distinct FC patterns between infants with vs without FHD in the left fusiform gyrus (classification accuracy, 0.55 [99% CI, 0.046-0.062]; corrected P < .001; Cohen d = 0.76). Connections linking left fusiform gyrus to regions in the frontal and parietal language and attention networks were among the paths with the highest contributions to the classification performance. Conclusions and Relevance These findings suggest that on the group level, FHD was associated with an early onset of atypical FC of regions important for subsequent word form recognition during reading acquisition. Longitudinal studies linking the atypical functional network and school-age reading abilities will be essential to further elucidate the ontogenetic mechanisms underlying the development of dyslexia.
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Affiliation(s)
- Xi Yu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, Massachusetts
| | - Silvina Ferradal
- Department of Intelligent Systems Engineering, Indiana University, Bloomington
| | - Jade Dunstan
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts
| | - Clarisa Carruthers
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts
| | - Joseph Sanfilippo
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts
| | - Jennifer Zuk
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, Massachusetts
| | - Lilla Zöllei
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston
| | - Borjan Gagoski
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, Massachusetts
- Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Yangming Ou
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, Massachusetts
- Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - P. Ellen Grant
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, Massachusetts
- Department of Radiology, Boston Children’s Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
| | - Nadine Gaab
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, Massachusetts
- Harvard Medical School, Boston, Massachusetts
- Harvard Graduate School of Education, Cambridge, Massachusetts
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Yu X, Ferradal SL, Sliva DD, Dunstan J, Carruthers C, Sanfilippo J, Zuk J, Zöllei L, Boyd E, Gagoski B, Ou Y, Grant PE, Gaab N. Functional Connectivity in Infancy and Toddlerhood Predicts Long-Term Language and Preliteracy Outcomes. Cereb Cortex 2021; 32:bhab230. [PMID: 34347052 PMCID: PMC10847903 DOI: 10.1093/cercor/bhab230] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Functional connectivity (FC) techniques can delineate brain organization as early as infancy, enabling the characterization of early brain characteristics associated with subsequent behavioral outcomes. Previous studies have identified specific functional networks in infant brains that underlie cognitive abilities and pathophysiology subsequently observed in toddlers and preschoolers. However, it is unknown whether and how functional networks emerging within the first 18 months of life contribute to the development of higher order, complex functions of language/literacy at school-age. This 5-year longitudinal imaging project starting in infancy, utilized resting-state functional magnetic resonance imaging and demonstrated prospective associations between FC in infants/toddlers and subsequent language and foundational literacy skills at 6.5 years old. These longitudinal associations were shown independently of key environmental influences and further present in a subsample of infant imaging data (≤12 months), suggesting early emerged functional networks specifically linked to high-order language and preliteracy skills. Moreover, emergent language skills in infancy and toddlerhood contributed to the prospective associations, implicating a role of early linguistic experiences in shaping the FC correlates of long-term oral language skills. The current results highlight the importance of functional organization established in infancy and toddlerhood as a neural scaffold underlying the learning process of complex cognitive functions.
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Affiliation(s)
- Xi Yu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing 100875, China
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Silvina L Ferradal
- Department of Intelligent Systems Engineering, Indiana University, Bloomington, IN 47408, USA
| | - Danielle D Sliva
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Jade Dunstan
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Clarisa Carruthers
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Joseph Sanfilippo
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Jennifer Zuk
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA 02215, USA
| | - Lilla Zöllei
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02129, USA
| | - Emma Boyd
- A.A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Boston, MA 02129, USA
| | - Borjan Gagoski
- Harvard Medical School, Boston, MA 02115, USA
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Radiology, Boston Children's Hospital, Boston, MA 02215, USA
| | - Yangming Ou
- Harvard Medical School, Boston, MA 02115, USA
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Radiology, Boston Children's Hospital, Boston, MA 02215, USA
- Computational Health Informatics Program, Boston Children's Hospital, Boston, MA 02115, USA
| | - P Ellen Grant
- Harvard Medical School, Boston, MA 02115, USA
- Fetal Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Radiology, Boston Children's Hospital, Boston, MA 02215, USA
- Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Nadine Gaab
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children’s Hospital, Boston, MA 02115, USA
- Harvard Medical School, Boston, MA 02115, USA
- Harvard Graduate School of Education Boston, Boston, MA 02115, USA
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Zuk J, Yu X, Sanfilippo J, Figuccio MJ, Dunstan J, Carruthers C, Sideridis G, Turesky TK, Gagoski B, Grant PE, Gaab N. White matter in infancy is prospectively associated with language outcomes in kindergarten. Dev Cogn Neurosci 2021; 50:100973. [PMID: 34119849 PMCID: PMC8209179 DOI: 10.1016/j.dcn.2021.100973] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 06/01/2021] [Accepted: 06/01/2021] [Indexed: 12/24/2022] Open
Abstract
Language acquisition is of central importance to child development. Although this developmental trajectory is shaped by experience postnatally, the neural basis for language emerges prenatally. Thus, a fundamental question remains: do structural foundations for language in infancy predict long-term language abilities? Longitudinal investigation of 40 children from infancy to kindergarten reveals that white matter in infancy is prospectively associated with subsequent language abilities, specifically between: (i) left arcuate fasciculus and phonological awareness and vocabulary knowledge, (ii) left corticospinal tract and phonological awareness, and bilateral corticospinal tract with phonological memory; controlling for age, cognitive, and environmental factors. Findings link white matter in infancy with school-age language abilities, suggesting that white matter organization in infancy sets a foundation for long-term language development.
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Affiliation(s)
- Jennifer Zuk
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA, 02215, USA; Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA.
| | - Xi Yu
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA; State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Joseph Sanfilippo
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA
| | | | - Jade Dunstan
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Clarisa Carruthers
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Georgios Sideridis
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA; Harvard Medical School, Boston, MA, 02115, USA
| | - Ted K Turesky
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA; Harvard Medical School, Boston, MA, 02115, USA
| | - Borjan Gagoski
- Harvard Medical School, Boston, MA, 02115, USA; Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Patricia Ellen Grant
- Harvard Medical School, Boston, MA, 02115, USA; Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Nadine Gaab
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Department of Medicine, Boston Children's Hospital, Boston, MA, 02115, USA; Harvard Medical School, Boston, MA, 02115, USA; Harvard Graduate School of Education, Cambridge, MA, 02138, USA
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Ferradal SL, Gagoski B, Jaimes C, Yi F, Carruthers C, Vu C, Litt JS, Larsen R, Sutton B, Grant PE, Zöllei L. System-Specific Patterns of Thalamocortical Connectivity in Early Brain Development as Revealed by Structural and Functional MRI. Cereb Cortex 2020; 29:1218-1229. [PMID: 29425270 DOI: 10.1093/cercor/bhy028] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Indexed: 01/31/2023] Open
Abstract
The normal development of thalamocortical connections plays a critical role in shaping brain connectivity in the prenatal and postnatal periods. Recent studies using advanced magnetic resonance imaging (MRI) techniques in neonates and infants have shown that abnormal thalamocortical connectivity is associated with adverse neurodevelopmental outcomes. However, all these studies have focused on a single neuroimaging modality, overlooking the dynamic relationship between structure and function at this early stage. Here, we study the relationship between structural and functional thalamocortical connectivity patterns derived from healthy full-term infants scanned with diffusion-weighted MRI and resting-state functional MRI within the first weeks of life (mean gestational age = 39.3 ± 1.2 weeks; age at scan = 24.2 ± 7.9 days). Our results show that while there is, in general, good spatial agreement between both MRI modalities, there are regional variations that are system-specific: regions involving primary-sensory cortices exhibit greater structural/functional overlap, whereas higher-order association areas such as temporal and posterior parietal cortices show divergence in spatial patterns of each modality. This variability illustrates the complementarity of both modalities and highlights the importance of multimodal approaches.
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Affiliation(s)
| | - Borjan Gagoski
- Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Camilo Jaimes
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Francesca Yi
- Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Catherine Vu
- Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | | | - Ryan Larsen
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Brad Sutton
- Beckman Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - P Ellen Grant
- Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lilla Zöllei
- Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Abstract
BACKGROUND Deficiencies in management have been highlighted as contributory factors in the death of many patients with acute kidney injury (AKI). However, there is little evidence addressing the quality of care provided to patients with milder AKI. AIM The aim of this study is to evaluate the quality of care provided to a non-select cohort of patients with AKI and evaluate discrepancies in causation, recognition and management. DESIGN Retrospective inception cohort study. METHODS Demographic data were collected for all 1577 patients admitted to a University Teaching Hospital during a 1-month period. Baseline, admission and peak creatinine were correlated with mortality and length of hospital admission. AKI was classified according to Kidney Disease Improving Global Outcomes criteria. A retrospective case note review of all patients with AKI was carried out to evaluate quality of documentation and clinical management of AKI. Multivariate analysis was undertaken to determine risk factors for AKI. RESULTS Incidence of AKI on admission was 4.6%. A further 10.3% developed AKI while in hospital. All cause mortality was 4-fold higher among patients with AKI compared with those without (19 vs. 3.8%; P < 0.001). Mortality was significantly higher in those patients who developed AKI while an in-patient compared with those with AKI on admission (27.3 vs. 11.8%; P < 0.001). Diabetes, clinician perception of frailty, age and treatment with angiotensin-converting enzyme inhibitor prior to admission were found to be independent risk factors for AKI. AKI was unrecognized in 23.5% of patients, two-thirds of whom were discharged without resolution of renal function. Significant weaknesses in management were poorly kept fluid balance charts (48.2%), failure to withhold nephrotoxic drugs (38.8%) and failure to act upon abnormal biochemistry (41%) in a timely fashion. CONCLUSION AKI is common in hospitalized patients and associated with a significant increase in hospital stay and mortality. AKI is often found in conjunction with other organ failure and in many cases is not preventable. Nevertheless clinicians need to be more vigilant of small creatinine rises to permit early intervention particularly among elderly and frail patients.
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Affiliation(s)
- E Aitken
- Department of Renal Surgery, Western Infirmary, Glasgow G11 6NY, UK.
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Carruthers C, Gabrush T, Schwean-Lardner K, Knezacek T, Classen H, Bennett C. On-farm survey of beak characteristics in White Leghorns as a result of hot blade trimming or infrared beak treatment. J APPL POULTRY RES 2012. [DOI: 10.3382/japr.2011-00433] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Hardie MJ, Carruthers C, Henkelis JJ, Little MA, Ronson TK, Sumby CJ. New coordination polymers with embedded molecular recognition functionality. Acta Crystallogr A 2011. [DOI: 10.1107/s0108767311090969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Hardie M, Carruthers C, Fisher J, Harding L, Prior T, Rizkallah P, Ronson T, Westcott A. Star-burst metallo-supramolecular prisms and coordination polymers with pyramidal ligands. Acta Crystallogr A 2008. [DOI: 10.1107/s0108767308096694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Saginur R, Nixon J, Devries B, Bruce N, Carruthers C, Scully L, Berger R, Leech J, Nicolle L, Mackenzie A. Transmission of hepatitis C in a pharmacologic study. Infect Control Hosp Epidemiol 2001; 22:697-700. [PMID: 11842990 DOI: 10.1086/501848] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 11/04/2022]
Abstract
OBJECTIVE To describe an outbreak of hepatitis C in a clinical research study. DESIGN Observational study. SETTING Tertiary-care hospital. PATIENTS Healthcare workers who volunteered to be subjects in a study of the metabolic effects of inhaled and oral corticosteroids who were unwittingly exposed to hepatitis C virus (HCV). METHODS Epidemiological investigation and serological analyses. RESULTS One chronic carrier of HCV was identified. Four fellow workers volunteering in the studies became infected with HCV, with 96% homology among strains. There was no evidence of spread from infected healthcare workers to patients on whom they had performed arterial punctures (2 of 214 positive, unrelated to each other and to the outbreak strain). CONCLUSION Infection control standards in clinical research must be maintained vigorously to prevent transmission of blood-borne pathogens such as HCV.
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Affiliation(s)
- R Saginur
- Division of Infectious Diseases, Ottawa Hospital and the University of Ottawa, Ontario, Canada
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Carruthers C. Saying goodbye to Canada's single-payer system. CMAJ 1995; 152:731-3. [PMID: 7882234 PMCID: PMC1337621] [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: 01/27/2023] Open
Abstract
Cost shifting, in which governments transfer the cost of certain health care services to patients or private insurance companies, is increasing rapidly, and Dr. Christopher Carruthers thinks it will spell an end to Canada's single-payer system. The signs are already there: the private sector is offering more services and employers are keeping a closer eye on the health care system as they begin to pay a bigger share of the costs. The result, says Carruthers, is that government influence is bound to diminish as the private sector tries to fill voids created by governments that are trying to live within their fiscal means.
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Abstract
The nuclear proto-oncoprotein Myc has been implicated in the control of cell proliferation and differentiation. Myc participates in transcription and belongs to the basic-helix-loop-helix (bHLH) family of regulatory proteins. Here we show that Myc interacts with TFII-I, a transcription initiation factor that activates core promoters through an initiator element (Inr). As previously observed for the bHLH activator USF, Myc was found to interact cooperatively with TFII-I at both Inr and upstream E-box promoter elements. However, in this case Myc interactions with TFII-I at the Inr lead to an inhibition of transcription initiation. This inhibition is selective for a TFII-I-dependent (as opposed to TFIIA-dependent) initiation pathway and correlates with the prevention of complex formation between the TATA-binding protein TBP (TFIID tau), TFII-I and the promoter. TBP probably interacts with Myc, but only slowly. These observations indicate that Myc has the potential to interact physically and functionally with components of the general transcription machinery.
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Affiliation(s)
- A L Roy
- Laboratory of Biochemistry and Molecular Biology, Rockefeller University, New York, New York 10021
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Carruthers C, Neilson A. Effect of 12-O-tetradecanoyl-phorbol-13-acetate and 3-methylcholanthrene on the toxicity of nicotine applied to mouse skin. Oncology 1983; 40:404-9. [PMID: 6646607 DOI: 10.1159/000225774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The effect of the tumor promoter, 12-O-tetradecanoyl-phorbol-13-acetate (TPA) and 3-methylcholanthrene (MCA) on the toxicity of nicotine and the content of this alkaloid in mouse skin has been determined following the application of these reagents to the skin. TPA or MCA was applied to mouse skin at time 0, and then at various time intervals thereafter, nicotine was applied to the skin. The content of this alkaloid (nicotine DNA ratio) remaining in the skin was then determined 1/2 h after its application. After the application of TPA, the nicotine DNA ratio of the skin decreased from 120 at 1.8 h to 80 at 18 h, increased sharply from 24 h, reaching a maximum of 165 at 72 h, and then decreased gradually. As the nicotine DNA ratio of the skin increased, the mortality rate of the mice also increased, reaching a maximum of over 40% at 48 and 72 h following the application of TPA. When MCA was applied to mouse skin in the same fashion and then nicotine, there was a decrease in the nicotine DNA ratio similar to that induced by TPA and nicotine followed by an average increase in the nicotine DNA ratio of 130 at 72, 96 and 120 h. The mortality rate of these mice was low. Finally, ethyl phenyl propiolate (EPP) was applied to mouse skin at time 0, and nicotine was applied 24, 48, 72, 96 and 120 h later. The mortality rate was also quite low at these times 1/2 h after application of nicotine (nicotine was not determined in the skin). TPA has induced some change in the skin 24, 48, 72 and 96 h after its application which resulted in an increase in the toxicity of nicotine to mice. Nicotine was not detected by the gas chromatographic method employed in the serum or plasma of nicotine-treated and TPA and nicotine-treated mice even though the mice showed acute reactions of nicotine toxicity and the skin surface contained ample amounts of this alkaloid.
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Carruthers C, Neilson A. Effect of the tumor promotor 12-O-tetradecanoylphorbol-13-acetate on the rate of disappearance of nicotine from mouse skin. Oncology 1982; 39:365-8. [PMID: 7133601 DOI: 10.1159/000225673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The rate of disappearance of nicotine from mouse skin was increased by the presence of 12-O-tetradecanoylphorbol-13-acetate (TPA) during the first 2-hour period following the application of nicotine to mouse skin. The biological half-life (t1/2) for nicotine alone was 1.2-1.3 h whereas in the presence of TPA, t1/2 was 0.8 to 0.9 h. The disappearance of nicotine from mouse skin followed first-order kinetics over a period of 6 h whereas the loss of nicotine in the presence of TPA from mouse skin followed first-order kinetics for the first 2 h, then the nicotine level became fairly constant for the time period of 2-5 h. Benzo (alpha) pyrene did not affect the rate of disappearance of nicotine from mouse skin. Neither cotinine nor nicotine 1'-N oxide, metabolites of nicotine, was detected in mouse skin following the topical application of this alkaloid.
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Abstract
Ligandin was detected by immunofluorescence in tissue sections and determined by immunoquantitation in the cytosols of the liver, kidney and testes of normal and carcinogen-treated rats. Ligandin was not detected by either of these procedures in normal or carcinogen-treated rat lung, spleen, brain, and skeletal or cardiac muscle.
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Carruthers C, Baumler A, Lin JK. Detection by antihapten antibodies of liver-bound compounds related to azocarcinogens or their metabolites. Oncology 1979; 36:211-5. [PMID: 90352 DOI: 10.1159/000225344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The localization of known azocarcinogens and metabolites such as p-aminoazobenzene and N-methyl-p-aminoazobenzene bound to components of liver cells of rats fed single or multiple doses of 3'-methyl-p-dimethylaminoazobenzene has been determined with the use of antibodies raised against p'-azo-p-aminoazobenzene and p'-azo-N-monomethyl-p-aminoazobenzene in the indirect fluorescent antibody procedure. These 2 antisera reacted with liver cells of rats fed 3'-methyl-p-dimethylaminoazobenzene, p'-amino-p-aminoazobenzene, p'-amino-N-monomethyl-p-aminoazobenzene and N-methyl-p-aminoazobenzene. The results obtained in this study suggest that both major and minor metabolites of azocarcinogens have common antigenic determinants.
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Carruthers C, Baumler A. Distribution of ligandin in normal and azocarcinogen-treated rat liver and azocarcinogen-induced liver tumors. Oncology 1979; 36:265-70. [PMID: 117413 DOI: 10.1159/000225356] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Antibodies were raised in rabbits against pure ligandin. Employing the fluorescent antibody procedure, an antigen identical to ligandin was shown to be uniformly distributed in the hepatic cells of both normal rat liver and in early and late 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB)-treated liver. Ligandin was absent in liver carcinomas induced by this azocarcinogen. The results obtained with fluorescent antibody procedure were confirmed by the immunoquantitation of ligandin in the cytosols prepared from normal rat liver, early and late 3'-Me-DAB-treated liver, mixtures of both late 3'-Me-DAB-treated liver and liver carcinomas and liver carcinomas. Riboflavin-deficient diets lowered significantly the hepatic ligandin content.
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Carruthers C, Baumler A, Pauly S. Hepatoma induction in the rat by the subcutaneous administration of powdered 3'-methyl-p-dimethylaminoazobenzene. Experientia 1978; 34:788. [PMID: 207561 DOI: 10.1007/bf01947328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A relatively safe and simple procedure was developed for the induction of hepatomas in the rat by the s.c. administration of powdered 3'-methyl-p-dimethylaminoazobenzene.
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Carruthers C. Correlation between carcinogenicity and polarographic reducibility of some N-substituted derivatives of 4-aminoazobenzene. Indian J Cancer 1978; 15:49-52. [PMID: 680782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Carruthers C, Baumler A, Neilson A. Localization of minor liver-bound metabolites of 3-methyl-p-dimethylaminoazobenzene with anti-hapten antibodies. Cancer Res 1977; 37:2099-104. [PMID: 405094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Carruthers C, Baumler A, Neilson A. A distinctive antigen present in liver carcinomas induced by 3'-methyl-p-dimethylaminoazobenzene. Oncology 1977; 34:47-51. [PMID: 70767 DOI: 10.1159/000225179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatocellular carcinomas and cholangiocarcinomas induced in rat liver by the administration of 3'-methyl-p-dimethyl-aminoazobenzene (3'-Me-DAB) were found to contain a carcinoma distinctive antigen by immunofluorescence, immunoelectrophoresis and immunodiffusion. This carcinoma distinctive antigen does not appear to be alpha-fetoprotein (AFP) or the preneoplastic antigen.
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Carruthers C, Baumler A, Neilson A, Pressman D. Detection of liver-bound metabolites of azocarcinogens by the use of anti-hapten antibodies. Cancer Res 1976; 36:1568-72. [PMID: 817798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The presence of the azocompounds, p-dimethylaminoazobenzene and 3'-methyl-p-dimethylaminoazobenzene, and p-amino-N-acetyl-N-methylaniline (or their metabolites) bound to components of the liver cells of rats fed a single large dose of each compound has been detected using rabbit antibodies raised against the p-azo-N-acetyl-N-methylaniline hapten in the indirect fluorescent antibody technique. Binding of these antibodies was seen on liver sections from rats fed any one of these compounds. When the anti-p-azo-N-acetyl-N-methylaniline antiserum was absorbed with either liver sediments or cytosol fractions from rats fed p-amino-N-acetyl-N-methylaniline, the antibodies reacting with the liver-bound compounds were removed from the antiserum. Also, absorption of the antiserum with liver sediments or cytosol fractions of rats fed either one of the azocompounds selectively removed all of the antibodies reacting with the livers of rats fed that compound but did not remove other antibodies that were still capable of reacting with liver cells of rats fed the other azocompound or p-amino-N-acetyl-N-methylaniline. Thus this antiserum appears to contain several different anti-p-azo-N-acetyl-N-methylaniline antibodies with different structural requirements for reaction. Some can react with the azocompounds or certain of their metabolites, while others require more of the p-azo-N-acetyl-N-methylaniline structure for reaction. Some of the antibodies appear to react with liver-bound p-dimethylaminoazobenzene but not with liver-bound 3'-methyl-p-dimethylaminoazobenzene, while still others react with 3'-methyl-p-dimethylaminoazobenzene but not with p-dimethylaminoazobenzene.
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Carruthers C, Baumler A, Neilson A, Pressman D. Binding of the azocarcinogen 3'-methyl-p-dimethylaminoazobenzene to cellular components of normal rat liver and azocarcinogen-induced hepatomas. Cancer Res 1975; 35:3798-06. [PMID: 172235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The location of binding sites for 3'-methyl-p-dimethylaminoazobenzene (3'-Me-DAB) or metabolites on components of rat liver cells and hepatoma cells in tumors induced by this carcinogen was determined at 2 stages during the induction of tumors in rats: (a) in normal liver immediately following the application of a massive dose of the azocarcinogen by intragastric feeding, and (b) in liver and tumor after hepatomas had developed following repeated exposures to the carcinogen by s.c. injections. Bound 3'-Me-DAB or metabolites were detected by the use of rabbit antisera directed against either p-azoazobenzene or p'-azo-p-dimethylaminoazobenzene in an indirect fluorescent antibody technique. Soon after massive intragastric doses of 3'-Me-DAB, the staining observed when the anti-p-azoazobenzene antiserum was used was principally on cytoplasmic components of liver cells with some staining of the intranuclear components. When the second antiserum, anti-p'-azo-p-dimethylaminoazobenzene antiserum, was used, the most intense fluorescent staining was on the nuclear membranes, although there was some cytoplasmic and intranuclear staining as well.
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Abstract
The prekeratin of the snout of cows was extracted with 0-1 mol/l citric acid-sodium citrate buffer, pH 2-6. The results of equilibrium ultracentrifugation analyses of this prekeratin strongly suggest that this protein is not homogeneous. This conclusion is in accordance with the observations of two other investigators whose data infer that there is no major homogeneous keratin precursor in cow's lip or snout epidermis.
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Kim U, Baumler A, Carruthers C, Bielat K. Immunological escape mechanism in spontaneously metastasizing mammary tumors. Proc Natl Acad Sci U S A 1975; 72:1012-6. [PMID: 48247 PMCID: PMC432454 DOI: 10.1073/pnas.72.3.1012] [Citation(s) in RCA: 96] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Immunological and biochemical studies of spontaneously metastasizing and nonmetastasizing rat mammary carcinomas and their plasma membranes indicated that: (i) all spontaneously metastasizing tumors have little or no demonstrable glycocalyx, while all nonmetastasizing tumors have a thick glycocalyx; (ii) there is a direct relationship between the glycocalyx and immunogenicity, and an inverse relationship with the metastasizing capacity of tumor cells, properties which can be quantitated by levels of the plasma membrane marker enzyme 5'-nucleotidase (EC3.1.3.5;5'-ribonucleotide phosphohydrolase) activity; (iii) the absence of glycocalyx from the metastasizing tumor cell surface seems to result from its dissociation from plasma membranes, for solubilized cell surface antigen is readily found in the blood of metastasizing tumor bearing rats, while there was no detectable tumor cell surface antigen in the blood of the nonmetastasizing tumor hosts tested; (iv) both metastasizing and nonmetastasizing mammary tumors appear to have a common soluble cell surface antigen; (v) in addition to this common antigen, there is another membrane-bound antigen in the nonmetastasizing, immunogenic tumor cell surface which presumably is the tumor specific transplantation antigen; and (vi) this antigen is immunobiologically unique, but seems to be immunochemically related to the common soluble antigen. It is postulated that the lack of an immunogenic coat and/or the presence of solubilized tumor cell surface antigen in the blood may provide an immune escape mechanism for tumor cells by interfering with cell-mediated immune response of tumor hosts, leading to their dissemination.
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Carruthers C. Differences in the urea-extracted or fibrous proteins of mouse epidermis at various stages of malignant transformation. Oncology 1974; 30:125-33. [PMID: 4375272 DOI: 10.1159/000224947] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Carruthers C. Differences in the urea-extracted proteins of mouse epidermis and squamous cell carcinomata determined by fluorescence microscopy. Br J Cancer 1973; 28:36-45. [PMID: 4198974 PMCID: PMC2009041 DOI: 10.1038/bjc.1973.68] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Fluorescence microscopy was used to demonstrate differences in the urea-extractable antigens of mouse epidermis and squamous cell carcinoma. When serum- and normal tissue sediment-absorbed antisera prepared against mouse epidermal urea-extracted proteins were further absorbed with carcinoma urea antigens, antisera specific for epidermis resulted. When antisera raised against the urea-extractable proteins of mouse squamous cell carcinomata were serum- and normal tissue sediment-absorbed and then further absorbed with epidermal urea antigens, antisera were prepared which stained papilloma and carcinoma, but not epidermis, and thus these antisera were not specific for carcinoma. Antisera prepared against the urea-extractable proteins of human epidermis reacted in immunodiffusion in agar with the epidermal urea proteins, but not with human squamous cell carcinoma urea proteins. Also antisera prepared against the carcinoma urea-extractable proteins reacted with these proteins in agar, but no reaction occurred with the epidermal urea-extractable proteins.
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Carruthers C, Bhattacharaya M. Antigenic changes in mouse epidermis at various stages of neoplastic transformation. Gan 1972; 63:299-305. [PMID: 4627370] [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: 01/11/2023]
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Bhattacharaya M, Carruthers C. Antigenic differences between normal mouse epidermis and methylcholanthrene-induced squamous-cell carcinomas. Oncology 1972; 26:1-15. [PMID: 4209538 DOI: 10.1159/000224646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Carruthers C, Kim U. The influence of transplantable rat mammary carcinomas and the Walker carcinoma 256 on the lipid composition of the muscle and liver of the host. Cancer Res 1968; 28:1110-5. [PMID: 4298057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Carruthers C. Polarographic analysis of certain fractions obtained from the urine of patients with malignancy and from normal individuals. Proc Soc Exp Biol Med 1968; 127:1214-7. [PMID: 5655667 DOI: 10.3181/00379727-127-32913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Carruthers C. Urocanic acid in epidermal carcinogenesis. J Invest Dermatol 1968; 50:41-6. [PMID: 4229844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Carruthers C. The fatty acid composition of the phosphatides of normal and malignant epidermis. Cancer Res 1967; 27:1-6. [PMID: 6020362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Carruthers C, Baumler A. Localization of fluorescein-labeled antibodies of epidermal proteins in normal and malignant squamous epithelium. J Natl Cancer Inst 1966; 37:301-15. [PMID: 5332336 DOI: 10.1093/jnci/37.3.301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
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Carruthers C, Suntzeff V. The Influence of Some Vitamin Deficient Diets on a Substance Characteristic of the Epidermis of the Mouse, Rat and Man****From the Wernse Laboratory for Cancer Research, Washington University Medical School, St. Louis, Mo.**Supported by a grant from the Charles F. Kettering Foundation and by a grant-in-aid from the American Cancer Society upon recommendation of the Committee on Growth of the National Research Council. J Invest Dermatol 1954. [DOI: 10.1038/jid.1954.87] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Estimations of the calcium content of the mouse epidermis during the process of experimental carcinogenesis reveal two distinct phases: an immediate reduction in the calcium content which persists at a fairly constant level for many weeks and a further reduction when the epithelial cells have been transformed into cancer cells. Reduction of calcium in the hyperplastic epidermis is an important feature in this experimentally induced precancerous condition. This investigation was aided by grants from the International Cancer Research Foundation and the National Cancer Institute.
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Carruthers C, Urban F. Isolation of a New "Carotenoid" from Rat Liver. Science 1942; 96:279-80. [PMID: 17840480 DOI: 10.1126/science.96.2490.279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
A new carotenoid-like substance has been isolated from rat liver. A method for its separation and some of its properties are given. The authors wish to express their gratitude to Dr. H. F. Seibert, of the S.M.A. Corporation, for the samples of the beta carotene used in these studies.
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