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1.
Qual Life Res ; 31(6): 1639-1656, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34748137

ABSTRACT

PURPOSE: Barrett esophagus (BE) is associated with a significant decrease of health-related quality of life (HRQoL). Too often, patient-reported outcome measures (PROMs) are applied without considering what they measure and for which purposes they are suitable. With this systematic review, we provide researchers and physicians with an overview of all the instruments previously used for measuring HRQoL in BE patients and which PROMs are most appropriate from the patient's perspective. METHODS: A comprehensive search was performed to identify all PROMs used for measuring HRQoL in BE patients, to identify factors influencing HRQoL according to BE patients, and to evaluate each PROM from a patients' perspective. RESULTS: Among the 27 studies, a total of 32 different HRQoL instruments were identified. None of these instruments were designed or validated for use in BE patients. Four qualitative studies were identified exploring factors influencing HRQoL in the perceptions of BE patients. These factors included fear of cancer, anxiety, trust in physician, sense of control, uncertainty, worry, burden of endoscopy, knowledge and understanding, gastrointestinal symptoms, sleeping difficulties, diet and lifestyle, use of medication, and support of family and friends. CONCLUSION: None of the quantitative studies measuring HRQoL in BE patients sufficiently reflected the perceptions of HRQoL in BE patients. Only gastrointestinal symptoms and anxiety were addressed in the majority of the studies. For the selection of PROMs, we encourage physicians and researchers measuring HRQoL to choose their PROMs from a patient perspective and not strictly based on health professionals' definitions of what is relevant.


Subject(s)
Barrett Esophagus , Neoplasms , Health Personnel , Humans , Patient Reported Outcome Measures , Quality of Life/psychology
2.
Cancer Invest ; 30(5): 422-32, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22571343

ABSTRACT

The gene encoding PTPδ is mutated or downregulated in human cancers including neuroblastoma. Here, we functionally tested the tumor-suppressive potential of PTPδ in neuroblastoma cell lines by reconstitution of both short and long PTPδ isoforms. We did not observe any significant difference in colony forming ability between cells expressing wild-type or catalytically inactive PTPδ. Although endogenous PTPδ expression was very low in neuroblastoma cells, it was also low in mouse embryo adrenal glands, suggesting that PTPδ may have little developmental function in early adrenal neuroblasts. This study, therefore, questions the significance of PTPδ as a tumor suppressor protein in neuroblastoma.


Subject(s)
Neuroblastoma/pathology , Receptor-Like Protein Tyrosine Phosphatases, Class 2/physiology , Tumor Suppressor Proteins/physiology , Adrenal Glands/metabolism , Animals , Cell Line, Tumor , Humans , Mice
3.
J Cell Biol ; 111(1): 217-28, 1990 Jul.
Article in English | MEDLINE | ID: mdl-2164029

ABSTRACT

We demonstrate that the behavior of cells expressing v-src, a tyrosine kinase oncogene, differs profoundly between the embryonic and culture environments. V-src was introduced into avian embryo cells both in culture and in stage-24 embryo limbs, using replication-defective retroviral vectors. These vectors were used as single-hit, cellular markers to determine the environmental influences imposed by normal cells and tissues on clonal cell growth. The marker gene lacZ was coexpressed with v-src in order to locate the descendent cells. In culture, v-src induced rapid morphological transformation and anchorage-independent growth of embryo fibroblasts; the vectors were also tumorigenic in hatchling chickens. In contrast, most of the cell clones expressing v-src in the embryo grew normally without neoplasia. Expression of v-src vectors could be found in a wide range of cell types, demonstrating not only that neoplastic transformation is attenuated in ovo, but also that differentiation commitment in many lineages can be maintained concurrently with oncogene expression. Significantly, the embryonic control of cell growth could be perturbed by v-src under certain conditions. Rare, marked clones showed hyperplasia or dysplasia, and the primitive endothelium could succumb to rapid neoplasia; thus, these embryonic tissues are not inherently deficient in transformation factors. We propose that the environmental conditions imposed on cells in ovo are critical for the attenuation of neoplasia, while cultured cells lose this requisite environment.


Subject(s)
Embryonic and Fetal Development , Oncogene Protein pp60(v-src)/genetics , Oncogenes , Protein-Tyrosine Kinases/genetics , Animals , Avian Sarcoma Viruses/genetics , Cell Division , Cell Line , Cell Transformation, Neoplastic , Cells, Cultured , Chick Embryo , Clone Cells , Endothelium/cytology , Endothelium/enzymology , Epithelial Cells , Epithelium/enzymology , Gene Expression , Genetic Vectors
4.
J Cell Biol ; 147(2): 375-88, 1999 Oct 18.
Article in English | MEDLINE | ID: mdl-10525542

ABSTRACT

Retinal ganglion cell axons grow towards the optic fissure in close contact with the basal membrane, an excellent growth substratum. One of the ligands of receptor tyrosine phosphatase CRYPalpha is located on the retinal and tectal basal membranes. To analyze the role of this RPTP and its ligand in intraretinal growth and guidance of ganglion cell axons, we disrupted ligand- receptor interactions on the retinal basal membrane in culture. Antibodies against CRYPalpha strongly reduced retinal axon growth on the basal membrane, and induced a dramatic change in morphology of retinal growth cones, reducing the size of growth cone lamellipodia. A similar effect was observed by blocking the ligand with a CRYPalpha ectodomain fusion protein. These effects did not occur, or were much reduced, when axons were grown either on laminin-1, on matrigel or on basal membranes with glial endfeet removed. This indicates that a ligand for CRYPalpha is located on glial endfeet. These results show for the first time in vertebrates that the interaction of a receptor tyrosine phosphatase with its ligand is crucial not only for promotion of retinal axon growth but also for maintenance of retinal growth cone lamellipodia on basal membranes.


Subject(s)
Avian Proteins , Axons/ultrastructure , Protein Tyrosine Phosphatases/physiology , Retinal Ganglion Cells/physiology , Retinal Ganglion Cells/ultrastructure , Animals , Axons/physiology , Cell Adhesion Molecules/physiology , Cell Communication , Cells, Cultured , Laminin/physiology , Ligands , Receptor-Like Protein Tyrosine Phosphatases , Signal Transduction/physiology
5.
J Biomech ; 41(6): 1153-9, 2008.
Article in English | MEDLINE | ID: mdl-18374344

ABSTRACT

Allografts of articular cartilage are both used clinically for tissue-transplantation procedures and experimentally as model systems to study the physiological behavior of chondrocytes in their native extracellular matrix. Long-term maintenance of allograft tissue is challenging. Chemical mediators in poorly defined culture media can stimulate cells to quickly degrade their surrounding extracellular matrix. This is particularly true of juvenile cartilage which is generally more responsive to chemical stimuli than mature tissue. By carefully modulating the culture media, however, it may be possible to preserve allograft tissue over the long-term while maintaining its original mechanical and biochemical properties. In this study juvenile bovine cartilage explants (both chondral and osteochondral) were cultured in both chemically defined medium and serum-supplemented medium for up to 6 weeks. The mechanical properties and biochemical content of explants cultured in chemically defined medium were enhanced after 2 weeks in culture and thereafter remained stable with no loss of cell viability. In contrast, the mechanical properties of explants in serum-supplemented medium were degraded by ( approximately 70%) along with a concurrent loss of biochemical content (30-40% GAG). These results suggest that long-term maintenance of allografts can be extended significantly by the use of a chemically defined medium.


Subject(s)
Cartilage , Tissue Culture Techniques , Animals , Biomechanical Phenomena , Cartilage/anatomy & histology , Cartilage/metabolism , Cattle , Culture Media, Serum-Free , Extracellular Matrix Proteins/metabolism , Glycoproteins/metabolism , Glycosaminoglycans/metabolism , Matrilin Proteins , Matrix Metalloproteinases/metabolism
6.
Curr Biol ; 6(7): 794-7, 1996 Jul 01.
Article in English | MEDLINE | ID: mdl-8835859

ABSTRACT

Recent results have revealed for the first time that receptor-like protein tyrosine phosphatases help to control the navigation of motor axons in the Drosophila nervous system.


Subject(s)
Axons/metabolism , Models, Molecular , Motor Neurons/metabolism , Neural Cell Adhesion Molecules/metabolism , Protein Tyrosine Phosphatases/metabolism , Signal Transduction/physiology , Animals , Drosophila
7.
Mol Cell Biol ; 4(8): 1508-14, 1984 Aug.
Article in English | MEDLINE | ID: mdl-6092915

ABSTRACT

Four temperature-sensitive (ts) Rous sarcoma virus src gene mutants with lesions in different parts of the gene represent three classes of alteration in pp60src. These classes are composed of mutants with (i) heat-labile protein kinase activities both in vitro and in vivo (tsLA27 and tsLA29), (ii) heat-labile kinases in vivo but not in vitro (tsLA33), and (iii) neither in vivo nor in vitro heat-labile kinases (tsLA32). The latter class indicates the existence of structural or functional pp60src domains that are required for transformation but do not grossly affect tyrosine kinase activity.


Subject(s)
Avian Sarcoma Viruses/genetics , Mutation , Protein Kinases/genetics , Viral Proteins/genetics , Amino Acids/analysis , Animals , Avian Sarcoma Viruses/enzymology , Chick Embryo , Oncogene Protein pp60(v-src) , Phosphorylation , Temperature , Viral Proteins/metabolism
8.
Mol Cell Biol ; 6(3): 959-63, 1986 Mar.
Article in English | MEDLINE | ID: mdl-3095630

ABSTRACT

Multipotential stem cell lines, derived specifically from long-term bone marrow cultures infected with a recombinant retrovirus carrying v-src, lack v-src. Stable consequences thus result from transient actions or indirect effects of v-src on other cells, with the latter possibility being favored by its mosaic expression in marrow cultures.


Subject(s)
Bone Marrow Cells , Cell Transformation, Neoplastic , Hematopoiesis , Hematopoietic Stem Cells/cytology , Moloney murine leukemia virus/genetics , Oncogenes , Retroviridae Proteins/genetics , Animals , Cell Line , Cells, Cultured , Fluorescent Antibody Technique , Genes , Mice , Oncogene Protein pp60(v-src) , Retroviridae Proteins/analysis
9.
Curr Opin Neurobiol ; 11(1): 95-102, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11179878

ABSTRACT

Receptor-like protein tyrosine phosphatases (RPTPs) continue to emerge as important signalling molecules in axons and their growth cones. Recent findings show that Drosophila RPTPs play key roles in guiding retinal axons and in preventing midline crossing of longitudinal axons. Vertebrate RPTPs are now implicated in controlling axon outgrowth, and preliminary evidence suggests that they too may influence axon guidance.


Subject(s)
Axons/physiology , Nervous System/growth & development , Protein Tyrosine Phosphatases/metabolism , Animals , Cell Movement , Drosophila , Leeches , Nervous System/cytology , Signal Transduction
11.
Cancer Res ; 49(22): 6419-24, 1989 Nov 15.
Article in English | MEDLINE | ID: mdl-2553256

ABSTRACT

Chickens given injections of Rous sarcoma virus form sarcomas at the site of inoculation (primary tumor) and at the site of experimentally introduced wounds (wound tumor). This latter finding provides a model system to study systematically the mechanisms underlying the cocarcinogenic effects of wounding. Our experiments show the following. (a) Chickens inoculated with a Rous sarcoma virus-derived, replication-defective virus construct fail to elaborate wound tumors in spite of aggressively growing primary tumors. We thus rule out metastasis as a mechanism and conclude that infectious virus is required for wound tumor formation; (b) using bromodeoxyuridine incorporation and immunofluorescence on frozen sections we demonstrate proliferation in the unwounded wing in cell types which are normally targets for Rous sarcoma virus infection and transformation and conclude that proliferation per se is not sufficient to induce wound tumors; (c) using immunohistochemistry for the viral protein p19gag we show that wounding induces virus expression in fibroblasts of newly forming granulation tissue 2 days after injury. We also demonstrate expression of viral mRNA in wound tumors by in situ hybridization with a v-src probe. We discuss the possibility of activation of integrated, silent virus or the preferential infection of a special target cell population as a result of wounding as well as the potential role of wound factors in transformation.


Subject(s)
Avian Sarcoma Viruses/pathogenicity , Sarcoma, Avian/complications , Wounds and Injuries/complications , Animals , Avian Sarcoma Viruses/genetics , Avian Sarcoma Viruses/isolation & purification , Bromodeoxyuridine/analysis , Bromodeoxyuridine/metabolism , Cell Division , Cell Transformation, Neoplastic , Chickens , DNA Replication , Fluorescent Antibody Technique , Gene Products, gag/analysis , Immunoenzyme Techniques , RNA, Messenger/genetics , Sarcoma, Avian/pathology , Wounds and Injuries/pathology
12.
Mech Dev ; 46(3): 201-17, 1994 Jun.
Article in English | MEDLINE | ID: mdl-7918104

ABSTRACT

The controlled development of embryo cells depends on their ability to monitor and respond to dynamic microenvironmental signals. This is frequently effected through membrane-associated receptor proteins which signal directly or indirectly through protein tyrosine phosphorylation. A search for such proteins in the developing nervous system of the chick has identified a new receptor-like protein tyrosine phosphatase (R-PTP) gene which may be responsible in part for this signalling. This gene, named CRYP alpha, is related to the LAR subfamily of R-PTPs and has extracellular homology to the neural cell adhesion molecules (CAMs). The gene is widely expressed in both the central and peripheral nervous systems, with particularly strong expression in motor neurons and in brain subregions such as the optic tectum and hypothalamus. Expression is seen both in early proliferating neuroepithelia and in subsets of post-mitotic nerve cells. Moreover, tissue-specific and developmentally-regulated exon use has been found in the brain, suggesting that isoforms of the R-PTP protein have stage-specific neural roles. This alternative RNA splicing event affects the encoded structure of the CAM-like domain, which may in turn influence its ligand binding properties. The novel, regulated expression of this R-PTP gene suggests that it plays a role in early neural development, and that the signalling properties of the encoded phosphatase can be modified according to the differentiated state of the cells.


Subject(s)
Cell Adhesion Molecules, Neuronal/physiology , Embryo, Nonmammalian/physiology , Isoenzymes/physiology , Nervous System/enzymology , Protein Tyrosine Phosphatases/physiology , Amino Acid Sequence , Animals , Base Sequence , Chick Embryo , Cloning, Molecular , Exons , In Situ Hybridization , Isoenzymes/analysis , Molecular Sequence Data , Nervous System/embryology , Protein Tyrosine Phosphatases/analysis , RNA Splicing , RNA, Messenger/biosynthesis
13.
Rev Neurol (Paris) ; 161(3): 290-8, 2005 Mar.
Article in French | MEDLINE | ID: mdl-15800450

ABSTRACT

INTRODUCTION: Over the last decades many approaches have been developed to manage cognitive and behavioral disturbances in dementia. The present work describes a global intervention program carried out with moderately to severely demented institutionalized patients. The aims of the intervention program are to stimulate and maintain the preserved abilities of demented patients in a supportive context, to decrease the behavioral disturbance and to avoid burnout of care-unit staff. METHODS: This intervention combines different means: psychosocial care (validation therapy, social interaction), cognitive stimulation (memory and verbal training), and motor and sensitive stimulation. The global intervention program requires a special trained team composed of a supervisor, six aid-nurses, an occupational therapist, a speech therapist, a psychomotor therapist and a psychologist. The team cared for the patients five days per week over a three-month period. Assessments were conducted before and after the intervention program to measure the benefit. RESULTS: Positive effects were shown for cognitive abilities, nutritional problems and staff burnout. However, due to the small sample size for this study, more research is needed to verify the effectiveness of this global intervention program, particularly the implications for nutrition. CONCLUSION: This global intervention combined with pharmacological treatment seems to be useful for managing psychological and behavioral disorders of institutionalized demented patients.


Subject(s)
Dementia/therapy , Activities of Daily Living , Aged , Aged, 80 and over , Burnout, Professional/prevention & control , Cognition/physiology , Cognitive Behavioral Therapy , Dementia/psychology , Female , Humans , Institutionalization , Male , Mental Disorders/therapy , Nutritional Physiological Phenomena , Patient Care Team , Psychomotor Performance/physiology
14.
Brain Res Dev Brain Res ; 90(1-2): 129-40, 1995 Dec 21.
Article in English | MEDLINE | ID: mdl-8719336

ABSTRACT

The avian CRYP alpha gene is expressed in the embryonic nervous system and encodes a receptor-like protein tyrosine phosphatase with structural similarity to neural cell adhesion molecules. To gain further insight into the role of the CRYP alpha phosphatase in neural development, this study addresses the protein's cellular distribution in the well characterised embryonic visual system. High levels of CRYP alpha protein localise in retinal axons extending from the eye to the tectum throughout the major growth periods of these nerve processes. In addition, primitive inner plexiform layer processes in the retina, tectobulbar axons, and non-retinal fibres of the tectal stratum opticum, contain large amounts of CRYP alpha. Its presence in non-fasciculated processes suggests that CRYP alpha has a role other than in fasciculation in short range fibres. In contrast to CRYP alpha, NgCAM is confined largely to axon fascicles in the retina and tectum, consistent with its demonstrated role in fasciculation of cultured neurites. In cultured retinal neurons CRYP alpha proteins reside both in neurite processes and in growth cone membranes, implicating both of these as potential functional locations for the protein. Although CRYP alpha continues to be expressed in the later embryo, the strong, early expression suggests a significant developmental role in the initial growth or guidance of nerve processes. This applies both over the longer range in the retinotectal and tectobulbar projections and over the shorter range within plexiform layers.


Subject(s)
Avian Proteins , Neural Cell Adhesion Molecules/analysis , Neurons/enzymology , Protein Tyrosine Phosphatases/analysis , Retina/chemistry , Superior Colliculi/chemistry , Visual Pathways/chemistry , Animals , Axons/chemistry , Cells, Cultured , Chick Embryo , Receptor-Like Protein Tyrosine Phosphatases , Retina/cytology , Retina/embryology , Subcellular Fractions/chemistry , Superior Colliculi/embryology , Visual Pathways/embryology
15.
Drug Alcohol Depend ; 25(3): 293-7, 1990 Jun.
Article in English | MEDLINE | ID: mdl-2347292

ABSTRACT

A group of 15- to 16-year-old adolescents were asked to report on their perception of their own family relationships, previous family experiences and their perceptions of their relationships with their fathers and with their mothers. They were also asked to report on their use of psychoactive drugs. Drug users were more likely than non-users to perceive their families as distant and less involved, with poor communications, mistrusting and punitive. Fathers were more likely perceived to be ineffective, and less significant than mothers. Drug users reported more parental separation, divorce, re-marriage and bereavement.


Subject(s)
Adolescent Behavior , Family/psychology , Perception , Substance-Related Disorders/psychology , Adolescent , Communication , Evaluation Studies as Topic , Father-Child Relations , Female , Humans , Male , Mother-Child Relations , Surveys and Questionnaires
16.
Soc Sci Med ; 27(5): 563-7, 1988.
Article in English | MEDLINE | ID: mdl-3227363

ABSTRACT

The production and consumption of allopathic medicines in less developed countries has far-reaching effects. In particular, the legitimization of allopathic medicine endows professional groups and sectors of industry with a special status, supports some patterns of healthcare, and neglects others. Research in India demonstrates that people equate "more drugs' with "a better situation' and this is seen as the most "appropriate' solution to India's pharmaceuticals problems. The belief is expressed in matters such as Government policy on the pharmaceutical industry and the development of health services. However, these dominant assumptions, and the equation of drug prescription with medical practice, have a negative effect on health.


Subject(s)
Developing Countries , Drug Therapy/trends , Health Policy/trends , Community Health Services/trends , Drug Industry , Humans , India , Pharmaceutical Services/trends
17.
J Am Vet Med Assoc ; 219(9): 1238-41, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11697366

ABSTRACT

OBJECTIVE: To determine the association between cancer chemotherapy and serum canine distemper virus (CDV), canine parvovirus (CPV), and rabies virus antibody titers in tumor-bearing dogs. DESIGN: Prospective study. ANIMALS: 21 client-owned dogs with various malignancies and 16 client-owned dogs with lymphoma. PROCEDURE: In study A, serum antibody titers were measured by use of hemagglutination inhibition (CPV titers) or serum neutralization (CDV titers) before and at least 1 month after initiation of chemotherapy. Baseline values were compared with values obtained from a control population of 122 healthy dogs seen for routine revaccination. Titers were considered protective at > or = 1:96 for CDV and > or = 1:80 for CPV. In study B, serum IgG titers were measured by use of immunofluorescent assay (CDV and CPV titers) and rapid fluorescent focus inhibition test (RFFIT, rabies titers) at baseline and again at weeks 5, 8, and 24 of a standard chemotherapy protocol for treatment of lymphoma. An IgG titer of > or = 1:50 was considered protective for CPV and CDV. An RFFIT titer of > or = 0.5 U/ml was considered protective for rabies virus. RESULTS: Significant changes were not detected in CDV, CPV, and rabies virus titers following chemotherapy in tumor-bearing dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that established immunity to CDV, CPV, and rabies virus from previous vaccination is not significantly compromised by standard chemotherapy used to treat tumor-bearing dogs.


Subject(s)
Antibodies, Viral/blood , Antineoplastic Agents/adverse effects , Distemper Virus, Canine/immunology , Dog Diseases/drug therapy , Neoplasms/veterinary , Parvovirus, Canine/immunology , Rabies virus/immunology , Animals , Disease Susceptibility , Dog Diseases/immunology , Dog Diseases/virology , Dogs , Fluorescent Antibody Technique/veterinary , Hemagglutination Inhibition Tests/veterinary , Immune Tolerance/drug effects , Immunoglobulin G/analysis , Lymphoma/drug therapy , Lymphoma/immunology , Lymphoma/veterinary , Neoplasms/drug therapy , Neoplasms/immunology , Neutralization Tests/veterinary , Prospective Studies
18.
Health Phys ; 73(1): 37-48, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9199217

ABSTRACT

Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for 137Cs, 90Sr, 239+240Pu and 241Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from 137Cs. 90Sr is the second most significant radionuclide via ingestion. External gamma exposure from 137Cs accounts for about 10% to 30% of the dose. 239+240Pu and 241Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y(-1) to 2.1 mSv y(-1). The background dose in the Marshall Islands is estimated to be 2.4 mSv y(-1). The combined dose from both background and bomb related radionuclides ranges from slightly over 2.4 mSv y(-1) to 4.5 mSv y(-1). The 50-y integral dose ranges from 0.5 to 65 mSv.


Subject(s)
Nuclear Warfare , Radiation Monitoring , Cesium Radioisotopes/analysis , Micronesia , Radiation Dosage , Strontium Radioisotopes/analysis
19.
J Environ Radioact ; 69(3): 207-23, 2003.
Article in English | MEDLINE | ID: mdl-12832159

ABSTRACT

The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the 137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr that is currently unknown, but some loss of 90Sr does occur along with 137Cs. If the 15-year upper 95% confidence limit on ELH (corresponding to an effective half-life of 9.8 years) is incorporated into dose calculations projected over periods of 30, 50, or 70 years, then corresponding integral doses are 58, 46 and 41%, respectively, of those previously calculated based solely on radiological decay of 137Cs.


Subject(s)
Environmental Monitoring/methods , Nuclear Warfare , Radioactive Fallout/analysis , Soil Pollutants, Radioactive/analysis , Cesium Radioisotopes/analysis , Fruit/chemistry , Half-Life , Plant Leaves/chemistry , Plants , Soil Pollutants, Radioactive/pharmacokinetics
20.
East Afr Med J ; 78(12): 682-5, 2001 Dec.
Article in English | MEDLINE | ID: mdl-12199454

ABSTRACT

Glutaric aciduria type 1 (GA-1) is an inborn error of metabolism caused by a deficiency of the mitochondrial enzyme glutaryl-Co enzyme A dehydrogenase. GA-1 is not uncommon amongst Caucasians but to the best of our knowledge, it has previously not been reported in black African children. We present a case of GA-1 in a black South African boy who was referred to hospital at the age of five years and ten 10 months with dyskinesia and dystonia accompanied by chorea and athetosis. Radiological examination revealed enlarged basal cisterns with bilateral fluid collection around the sylvian fissures suggestive of GA-1. Analysis of urine showed raised levels of glutaric acid at 520 micromol/mmol creatinine (normal <2.0), 3-hydroxyglutaric acid at 113 micromol/mmol creatinine (normal <3.0) and a low blood carnitine level of 31.5 micromol/l (normal 35-84). A definitive diagnosis was reached through DNA analysis which revealed homozygosity for an A293T mutation in the glutaryl-Co-enzyme A dehydrogenase (GCDH) gene.


Subject(s)
Amino Acid Metabolism, Inborn Errors/diagnosis , Glutarates/metabolism , Amino Acid Metabolism, Inborn Errors/genetics , Child, Preschool , Humans , Male , Sequence Analysis, DNA
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