Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 29
Filter
1.
Eur J Cancer ; 107: 133-141, 2019 01.
Article in English | MEDLINE | ID: mdl-30576969

ABSTRACT

OBJECTIVE: The computer-adaptive test (CAT) of the European Organisation for Research and Treatment of Cancer (EORTC), the EORTC CAT Core, assesses the same 15 domains as the EORTC QLQ-C30 health-related quality of life questionnaire but with increased precision, efficiency, measurement range and flexibility. CAT parameters for estimating scores have been established based on clinical data from cancer patients. This study aimed at establishing the European Norm for each CAT domain based on general population data. METHODS: We collected representative general population data across 11 European Union (EU) countries, Russia, Turkey, Canada and the United States (n ≥ 1000/country; stratified by sex and age). We selected item subsets from each CAT domain for data collection (totalling 86 items). Differential item functioning (DIF) analyses were conducted to investigate cross-cultural measurement invariance. For each domain, means and standard deviations from the EU countries (weighted by country population, sex and age) were used to establish a T-metric with a European general population mean = 50 (standard deviation = 10). RESULTS: A total of 15,386 respondents completed the online survey (n = 11,343 from EU countries). EORTC CAT Core norm scores for all 15 countries were calculated. DIF had negligible impact on scoring. Domain-specific T-scores differed significantly across countries with small to medium effect sizes. CONCLUSION: This study establishes the official European Norm for the EORTC CAT Core. The European CAT Norm can be used globally and allows for meaningful interpretation of scores. Furthermore, CAT scores can be compared with sex- and age-adjusted norm scores at a national level within each of the 15 countries.


Subject(s)
Factor Analysis, Statistical , Health Status , Neoplasms/psychology , Quality of Life , Surveys and Questionnaires/standards , Adolescent , Adult , Aged , Algorithms , Europe/epidemiology , Female , Humans , Male , Middle Aged , Neoplasms/diagnosis , Neoplasms/epidemiology , Neoplasms/therapy , Psychometrics , Reference Values , Sickness Impact Profile , Young Adult
2.
Eur J Cancer ; 107: 153-163, 2019 01.
Article in English | MEDLINE | ID: mdl-30576971

ABSTRACT

OBJECTIVE: The European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 health-related quality of life questionnaire is one of the most widely used cancer-specific health-related quality of life questionnaires worldwide. General population norm data can facilitate the interpretation of QLQ-C30 data obtained from cancer patients. This study aimed at systematically collecting norm data from the general population to develop European QLQ-C30 norm scores and to generate comparable norm data for individual countries in Europe and North America. METHODS: We collected QLQ-C30 data from the general population across 11 European Union (EU) countries, Russia, Turkey, Canada and United States (n ≥ 1000/country). Representative samples were stratified by sex and age groups (18-39, 40-49, 50-59, 60-69 and ≥ 70 years). After applying weights based on the United Nations population distribution statistics, we calculated QLQ-C30 domain scores to generate a 'European QLQ-C30 Norm' based on the EU countries. Further, we calculated QLQ-C30 norm scores for all 15 individual countries. RESULTS: A total of 15,386 respondents completed the online survey. For the EU sample, most QLQ-C30 domains showed differences by sex/age, with men scoring somewhat better health than women, while age effects varied across domains. Substantially larger differences were seen in inter-country comparisons, with Austrian and Dutch respondents reporting consistently better health compared with British and Polish respondents. CONCLUSIONS: This study is the first to systematically collect EORTC QLQ-C30 general population norm data across Europe and North America applying a consistent data collection method across 15 countries. These new norm data facilitate valid intra-country as well as inter-country comparisons and QLQ-C30 score interpretation.


Subject(s)
Health Status , Models, Statistical , Neoplasms/psychology , Quality of Life , Surveys and Questionnaires/standards , Adolescent , Adult , Aged , Algorithms , Canada/epidemiology , Europe/epidemiology , Female , Humans , Male , Middle Aged , Neoplasms/diagnosis , Neoplasms/epidemiology , Neoplasms/therapy , North America/epidemiology , Psychometrics , Reference Values , Social Class , Young Adult
3.
Article in English | MEDLINE | ID: mdl-28776784

ABSTRACT

The EORTC Quality of Life Group has just completed the final phase (field-testing and validation) of an international project to develop a stand-alone measure of spiritual well-being (SWB) for palliative cancer patients. Participants (n = 451)-from 14 countries on four continents; 54% female; 188 Christian; 50 Muslim; 156 with no religion-completed a provisional 36-item measure of SWB plus the EORTC QLQ-C15-PAL (PAL), then took part in a structured debriefing interview. All items showed good score distribution across response categories. We assessed scale structure using principal component analysis and Rasch analysis, and explored construct validity, and convergent/divergent validity with the PAL. Twenty-two items in four scoring scales (Relationship with Self, Relationships with Others, Relationship with Someone or Something Greater, and Existential) explained 53% of the variance. The measure also includes a global SWB item and nine other items. Scores on the PAL global quality-of-life item and Emotional Functioning scale weakly-moderately correlated with scores on the global SWB item and two of the four SWB scales. This new validated 32-item SWB measure addresses a distinct aspect of quality-of-life, and is now available for use in research and clinical practice, with a role as both a measurement and an intervention tool.


Subject(s)
Christianity , Islam , Neoplasms/therapy , Palliative Care , Religion and Medicine , Spirituality , Adolescent , Adult , Aged , Aged, 80 and over , Emotions , Female , Humans , Interpersonal Relations , Male , Middle Aged , Neoplasms/psychology , Quality of Life , Reproducibility of Results , Surveys and Questionnaires , Young Adult
4.
Mol Genet Genomics ; 271(3): 267-81, 2004 Apr.
Article in English | MEDLINE | ID: mdl-14760521

ABSTRACT

The maize endosperm undergoes programmed cell death late in its development so that, with the exception of the aleurone layer, the tissue is dead by the time the kernel matures. Although ethylene is known to regulate the onset of endosperm cell death, the temporal and spatial control of the ethylene biosynthetic and perception machinery during maize endosperm development has not been examined. In this study, we report the isolation of the maize gene families for ACC synthase, ACC oxidase, the ethylene receptor, and EIN2 and EIL, which act downstream of the receptor. We show that ACC oxidase is expressed primarily in the endosperm, and only at low levels in the developing embryo late in its development. ACC synthase is expressed throughout endosperm development but, in contrast to ACC oxidase, it is transiently expressed to a significantly higher level in the developing embryo at a time that corresponds with the onset of endosperm cell death. Only two ethylene receptor gene families were identified in maize, in contrast to the five types previously identified in Arabidopsis. Members of both ethylene receptor families were expressed to substantially higher levels in the developing embryo than in the endosperm, as were members of the EIN2 and EIL gene families. These results suggest that the endosperm and embryo both contribute to the synthesis of ethylene, and they provide a basis for understanding why the developing endosperm is especially sensitive to ethylene-induced cell death while the embryo is protected.


Subject(s)
Apoptosis , Arabidopsis Proteins/metabolism , Ethylenes/pharmacology , Gene Expression Regulation, Plant , Plant Growth Regulators/pharmacology , Zea mays/genetics , Amino Acid Oxidoreductases/genetics , Amino Acid Oxidoreductases/metabolism , Arabidopsis Proteins/genetics , Blotting, Southern , DNA, Plant/drug effects , DNA, Plant/metabolism , Ethylenes/biosynthesis , Lyases/genetics , Lyases/metabolism , Molecular Sequence Data , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Seeds/embryology , Seeds/metabolism , Zea mays/embryology , Zea mays/metabolism
5.
Plant Physiol ; 127(3): 777-91, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11706162

ABSTRACT

The plant heat stress protein, Hsp101, and the yeast ortholog, Hsp104, are required to confer thermotolerance in plants and yeast (Saccharomyces cerevisiae), respectively. In addition to its function during stress, Hsp101 is developmentally regulated in plants although its function during development is not known. To determine how the expression of Hsp101 is regulated in cereals, we investigated the Hsp101 expression profile in developing maize (Zea mays). Hsp101 protein was most abundant in the developing tassel, ear, silks, endosperm, and embryo. It was less abundant in the vegetative and floral meristematic regions and was present at only a low level in the anthers and tassel at anthesis, mature pollen, roots, and leaves. As expected, heat treatment resulted in an increase in the level of Hsp101 protein in several organs. In expanding foliar leaves, husk leaves, the tassel at the premeiosis stage of development, or pre-anthesis anthers, however, the heat-mediated increase in protein was not accompanied by an equivalent increase in mRNA. In contrast, the level of Hsp101 transcript increased in the tassel at anthesis following a heat stress without an increase in Hsp101 protein. In other organs such as the vegetative and floral meristematic regions, fully expanded foliar leaves, the young ear, and roots, the heat-induced increase in Hsp101 protein was accompanied by a corresponding increase in Hsp101 transcript level. However, anthers at anthesis, mature pollen, developing endosperm, and embryos largely failed to mount a heat stress response at the level of Hsp101 protein or mRNA, indicating that Hsp101 expression is not heat inducible in these organs. In situ RNA localization analysis revealed that Hsp101 mRNA accumulated in the subaleurone and aleurone of developing kernels and was highest in the root cap meristem and quiescent center of heat-stressed roots. These data suggest an organ-specific control of Hsp101 expression during development and following a heat stress through mechanisms that may include posttranscriptional regulation.


Subject(s)
Plant Proteins/genetics , Saccharomyces cerevisiae Proteins , Transcription Factors/genetics , Zea mays/genetics , Amino Acid Sequence , Gene Expression Regulation, Plant , Germination , Heat-Shock Proteins/genetics , Heat-Shock Proteins/metabolism , Hot Temperature , Molecular Sequence Data , Plant Proteins/metabolism , Plant Structures/genetics , Plant Structures/growth & development , Plant Structures/metabolism , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/growth & development , Saccharomyces cerevisiae/metabolism , Sequence Alignment , Transcription Factors/metabolism , Zea mays/growth & development , Zea mays/metabolism
6.
Plant Mol Biol ; 42(2): 397-414, 2000 Jan.
Article in English | MEDLINE | ID: mdl-10794539

ABSTRACT

Cereal endosperm undergoes programmed cell death (PCD) during its development, a process that is controlled, in part, by ethylene. Whether other hormones influence endosperm PCD has not been investigated. Abscisic acid (ABA) plays an essential role during late seed development that enables an embryo to survive desiccation. To examine whether ABA is also involved in regulating the onset of PCD during endosperm development, we have used genetic and biochemical means to disrupt ABA biosynthesis or perception during maize kernel development. The onset and progression of cell death, as determined by viability staining and the appearance of internucleosomal DNA fragmentation, was accelerated in developing endosperm of ABA-insensitive vp1 and ABA-deficient vp9 mutants. Ethylene was synthesized in vp1 and vp9 mutant kernels at levels that were 2-4-fold higher than in wild-type kernels. Moreover, the increase and timing of ethylene production correlated with the premature onset and accelerated progression of internucleosomal fragmentation in these mutants. Treatment of developing wild-type endosperm with fluridone, an inhibitor of ABA biosynthesis, recapitulated the increase in ethylene production and accelerated execution of the PCD program that was observed in the ABA mutant kernels. These data suggest that a balance between ABA and ethylene establishes the appropriate onset and progression of programmed cell death during maize endosperm development.


Subject(s)
Abscisic Acid/pharmacology , Apoptosis/drug effects , Seeds/drug effects , Zea mays/drug effects , Abscisic Acid/metabolism , Cyclopropanes/pharmacology , DNA Fragmentation/drug effects , DNA, Plant/genetics , DNA-Binding Proteins/genetics , Deoxyribonucleases/metabolism , Ethylenes/metabolism , Gibberellins/pharmacology , Glycine/analogs & derivatives , Glycine/pharmacology , Mutation , Nucleosomes/genetics , Plant Proteins , Pyridones/pharmacology , Seeds/growth & development , Seeds/metabolism , Trans-Activators , Transcription Factors/genetics , Zea mays/genetics , Zea mays/physiology
7.
Plant Mol Biol ; 44(3): 283-301, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11199389

ABSTRACT

The endosperm of cereals functions as a storage tissue in which the majority of starch and seed storage proteins are synthesized. During its development, cereal endosperm initiates a cell death program that eventually affects the entire tissue with the exception of the outermost cells, which differentiate into the aleurone layer and remain living in the mature seed. To date, the cell death program has been described for maize and wheat endosperm, which exhibits common and unique elements for each species. The progression of endosperm programmed cell death (PCD) in both species is accompanied by an increase in nuclease activity and the internucleosomal degradation of nuclear DNA, hallmarks of apoptosis in animals. Moreover, ethylene and abscisic acid are key to mediating PCD in cereal endosperm. The progression of the cell death program in developing maize endosperm follows a highly organized pattern whereas in wheat endosperm, PCD initiates stochastically. Although the essential characteristics of cereal endosperm PCD are now known, the molecular mechanisms responsible for its execution remain to be identified.


Subject(s)
Apoptosis , Seeds/growth & development , DNA Fragmentation , DNA, Plant/genetics , DNA, Plant/metabolism , Plant Cells , Plant Proteins/metabolism , Plants/genetics , Plants/metabolism , Seeds/genetics , Seeds/metabolism
8.
Pediatrics ; 104(6): 1345-50, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10585987

ABSTRACT

OBJECTIVE: To identify risk factors for chronic lung disease (CLD) in a population-based cohort of very low birth weight infants, born in an era of surfactant usage. We specifically investigated the effects of antenatal steroids, nosocomial infection, patent ductus arteriosus (PDA), fluid management, and ventilator support strategies. METHODS: Data were prospectively collected on 1244 infants born in North Carolina in 1994 with birth weights 500 to 1500 g, and treated at 1 of the 13 intensive care nurseries across the state. The outcome of interest was CLD, defined as dependency on supplemental oxygen at 36 weeks' postmenstrual age. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression models. RESULTS: Among 865 survivors to 36 weeks' postmenstrual age, 224 (26%) had CLD. Nosocomial infection (OR: 2.0; 95% CI: 1.4-3.3), fluid intake on day 2 (OR: 1.06 per 10 mL increase; 95% CI: 1.01-1.11), and the need for ventilation at 48 hours of life (OR: 2.2; 95% CI: 1.3-3.7) were associated with an increased risk of CLD. Among infants ventilated at 48 hours, nosocomial infection (OR: 1.64; 95% CI: 1.02-2.62) and PDA (OR: 1.9; 95% CI: 1.2-3.1) were associated with an increased risk. No association was found with antenatal steroid receipt or increased levels of ventilator support. CONCLUSION: This analysis suggests that with widespread use of surfactant, nosocomial infection, PDA, and water balance persist as risk factors for CLD.


Subject(s)
Infant, Premature, Diseases/prevention & control , Infant, Very Low Birth Weight , Lung Diseases/prevention & control , Pulmonary Surfactants/therapeutic use , Chronic Disease , Cohort Studies , Cross Infection/epidemiology , Cross Infection/prevention & control , Female , Humans , Infant , Infant, Newborn , Infant, Premature , Infant, Premature, Diseases/epidemiology , Logistic Models , Lung Diseases/epidemiology , Male , Multivariate Analysis , North Carolina/epidemiology , Prospective Studies , Risk Factors , Survivors/statistics & numerical data
9.
Pediatrics ; 104(2): e17, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10429135

ABSTRACT

OBJECTIVE: To assess the pulmonary outcomes of very low birth weight (VLBW) infants in North Carolina in 1994 and to compare rates of survival and chronic lung disease (CLD) between 1994 and 1984 (see reference 2). METHODS: Data were collected prospectively by collaborators from all 13 neonatal intensive care units in North Carolina to determine survival and pulmonary outcomes of infants with birth weights of 500 to 1500 g. State vital statistics data were used to confirm completeness of the sample. CLD was defined as oxygen or ventilator therapy at 36 weeks' postmenstrual age (PMA). For comparisons with the 1984 cohort, survival and pulmonary outcomes of infants defined to be at risk for CLD (ventilated >48 hours and survived 30 days) were recorded at 30 days, 3 months, and 6 months of postnatal age. RESULTS: Outcome data were available for 1413 (92%) of the in-state VLBW live births. Of VLBW infants, 224 (15%) died before 48 hours of age. The overall rate of CLD in 1994 at 36 weeks' PMA was 25%. Rates by birth weight group were 57% for 500 to 750 g birth weight (BW), 41% for 751 to 1000 g BW, 19% for 1001 to 1250 g BW, and 8% for 1251 to 1500 g BW. Infants who received ventilator therapy for >48 hours accounted for 89% of the CLD cases. The CLD rate at 36 weeks' PMA in infants weighing 751 to 1500 g was 37% for those ventilated >48 hours versus 5% for those ventilated <48 hours (OR: 7.1; 95% CI: 4.4-11.3). Overall survival in 1994 was significantly higher for infants than in 1984 (78% vs 74%), most notably in infants 500 to 750 g BW (37% vs 24%), and 751 to 1000 g BW (82% vs 65%). When compared with 1984, the CLD rates in those infants defined to be at risk were significantly higher in 1994 at 30 days (68% vs 54%) and at 3 months (24% vs 15%) of postnatal age. For at-risk infants in 1994, there were fewer infants on the ventilator, but more infants on oxygen alone at all measured time points compared with 1984. CONCLUSION: Survival of VLBW infants has improved since 1984. Ventilator therapy for >48 hours remains a significant risk factor for CLD. The incidence of CLD has increased from 1984 to 1994 but has shifted from ventilator to oxygen therapy. bronchopulmonary dysplasia, epidemiology, infant, low birth weight, intensive care units, neonatal statistics, infant mortality, prospective studies.


Subject(s)
Infant, Very Low Birth Weight , Lung Diseases/epidemiology , Chronic Disease , Fetal Death/epidemiology , Humans , Infant Mortality/trends , Infant, Newborn , North Carolina/epidemiology , Prospective Studies
10.
Plant Mol Biol ; 39(5): 915-26, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10344197

ABSTRACT

Although maize endosperm undergoes programmed cell death during its development, it is not known whether this developmental feature is common to cereals or whether it arose inadvertently from the selection process that resulted in the enlarged endosperm of modern maize. Examination of wheat endosperm during its development revealed that this tissue undergoes a programmed cell death that shares features with the maize program but differs in some aspects of its execution. Cell death initiated and progressed stochastically in wheat endosperm in contrast to maize where cell death initiates within the upper central endosperm and expands outward. After a peak of ethylene production during early development, wheat endosperm DNA underwent internucleosomal fragmentation that was detectable from mid to late development. The developmental onset and progression of DNA degradation was regulated by the level of ethylene production and perception. These observations suggest that programmed cell death of the endosperm and regulation of this program by ethylene is not unique to maize but that differences in the execution of the program appear to exist among cereals.


Subject(s)
Apoptosis , Edible Grain/genetics , Triticum/genetics , Cyclopropanes/pharmacology , DNA Fragmentation/drug effects , DNA, Plant/drug effects , DNA, Plant/metabolism , Deoxyribonucleases/metabolism , Edible Grain/embryology , Edible Grain/metabolism , Ethylenes/biosynthesis , Ethylenes/pharmacology , Nucleosomes/metabolism , Seeds/drug effects , Seeds/embryology , Seeds/metabolism , Triticum/embryology , Triticum/metabolism , Zea mays/embryology , Zea mays/genetics
11.
Arch Pediatr Adolesc Med ; 153(4): 331-8, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10201714

ABSTRACT

BACKGROUND: Preterm neonates are exposed to multiple painful procedures after birth and exhibit acute physiological responses to pain. Occurrence of early intraventricular hemorrhage within 24 to 72 hours after birth suggests a role of pain and stress in the multifactorial causation of severe intraventricular hemorrhage and periventricular leukomalacia. We proposed that such neurologic outcomes in preterm neonates who require ventilatory support may be reduced by morphine analgesia or midazolam sedation compared with a placebo. OBJECTIVES: To define the incidence of clinical outcomes in the target study population, to estimate the effect size and adverse effects associated with analgesia and sedation, and to calculate the sample size for a definitive test of this hypothesis. METHODS: Sixty-seven preterm neonates were randomized in a pilot clinical trial from 9 centers. Neonates of 24 to 32 weeks gestation were eligible if they had been intubated and required ventilatory support for less than 8 hours and if they were enrolled within 72 hours after birth. Exclusion criteria included major congenital anomalies, severe intrapartum asphyxia, and participation in other research studies. Severity of illness was assessed by the Clinical Risk Index for Babies, and neonates were randomized to receive continuous infusions of morphine sulfate, midazolam hydrochloride, or 10% dextrose (placebo). Masked study medications were continued as long as clinically necessary, then weaned and stopped according to predefined criteria. Levels of sedation (COMFORT scores) and responses to pain (Premature Infant Pain Profile scores) were measured before, during, and 12 hours after discontinuation of drug infusion. Cranial ultrasound examinations were performed as part of routine practice, and poor neurologic outcomes were defined as neonatal death, severe intraventricular hemorrhage (grade III or IV), or periventricular leukomalacia. RESULTS: No significant differences occurred in the demographic, clinical, and socioeconomic variables related to mothers and neonates in the 3 groups or in the severity of illness at birth as measured by Clinical Risk Index for Babies scores. Two neonates in the placebo group and 1 neonate in the midazolam group died; no deaths occurred in the morphine group. Poor neurologic outcomes occurred in 24% of neonates in the placebo group, 32% in the midazolam group, and 4% in the morphine group (likelihood ratio chi2 = 7.04, P = .03). Secondary clinical outcomes and neurobehavioral outcomes at 36 weeks' postconceptional age were similar in the 3 groups. Responses elicited by endotracheal tube suction (Premature Infant Pain Profile scores) were significantly reduced during the morphine (P<.001) and midazolam (P = .002) infusions compared with the placebo group. CONCLUSIONS: This pilot trial suggests that preemptive analgesia given by continuous low-dose morphine infusion may reduce the incidence of poor neurologic outcomes in preterm neonates who require ventilatory support. Limitations in the sample size of this pilot study suggest that these results should be confirmed in a large multicenter randomized trial.


Subject(s)
Analgesia/methods , Analgesics, Opioid/administration & dosage , Anesthetics, Intravenous/administration & dosage , Conscious Sedation/methods , Hypnotics and Sedatives/administration & dosage , Infant, Premature , Midazolam/administration & dosage , Morphine/administration & dosage , Respiration, Artificial , Analgesia/adverse effects , Conscious Sedation/adverse effects , Female , Humans , Infant, Newborn , Infusions, Intravenous , Male , Pilot Projects , Severity of Illness Index
12.
Talanta ; 45(6): 1189-99, 1998 Apr.
Article in English | MEDLINE | ID: mdl-18967111

ABSTRACT

Reversed phase high-performance liquid chromatography (RP-HPLC) is demonstrated for hydrophobic analytes such as aromatic hydrocarbons on a chemically bonded stationary phase and a mobile phase consisting of only water. Reversed phase liquid chromatography separations using a water-only mobile phase has been termed WRP-LC for water-only reversed phase LC. Reasonable capacity factors are achieved through the use of a non-porous silica substrate resulting in a chromatographic phase volume ratio much lower than usually found in RP-HPLC. Two types of bonded WRP-LC columns have been developed and applied. A brush phase was synthesized from an organochlorosilane. The other phase, synthesized from an organodichlorosilane, is termed a branch phase and results in a polymeric structure of greater thickness than the brush phase. A baseline separation of a mixture containing benzaldehyde, benzene, toluene, and ethyl benzene in less than 5 min is demonstrated using a water mobile phase with 12 000 plates generated for the unretained benzaldehyde peak. The theoretically predicted minimum reduced plate height is also shown to be approached for the unretained analyte using the brush phase. As an application, subcritical water extraction (SWE) at 200 degrees C is combined with WRP-LC. This combination allows for the extraction of organic compounds from solid matrices immediately followed by liquid chromatographic separation of those extracted compounds all using a solvent of 100% water. We demonstrate SWE/WRP-LC by spiking benzene, ethyl benzene, and naphthalene onto sand then extracting the analytes with SWE followed by chromatographic separation on a WRP column. A sand sample contaminated with gasoline was also analyzed using SWE/WRP-LC. This extraction process also provides kinetic information about the rate of analyte extraction from the sand matrix. Under the conditions employed, analytes were extracted at different rates, providing additional selectivity in addition to the WRP-LC separation.

13.
Curr Opin Pediatr ; 9(2): 184-8, 1997 Apr.
Article in English | MEDLINE | ID: mdl-9204248

ABSTRACT

Dexamethasone treatment of neonates to facilitate weaning from mechanical ventilation has become increasingly common. Despite thousands of infants being treated, most studies fail to demonstrate an improvement in long-term pulmonary and neurodevelopmental outcome. Much controversy remains regarding who should be treated, when treatment should begin, what the proper dose is, how long treatment should continue, and how adverse effects can be minimized. Early treatment prior to the onset of significant pulmonary inflammation may be an approach that improves outcomes and allows for shorter treatment courses. Risk assessment tools using ventilator requirements, adrenal function, or markers of pulmonary inflammation may allow for improved patient selection. Future studies will need to include a large number of subjects and will need to be continued beyond the neonatal period to assess long-term pulmonary and neurodevelopmental outcome.


Subject(s)
Dexamethasone/therapeutic use , Ventilator Weaning/methods , Humans , Infant, Newborn , Patient Selection
14.
Plant Physiol ; 115(2): 737-751, 1997 Oct.
Article in English | MEDLINE | ID: mdl-12223841

ABSTRACT

We characterized the progression of programmed cell death during maize (Zea mays L.) endosperm development of starchy (Su; wild-type) and shrunken2 (sh2) genotypes and tested the involve ment of ethylene in mediating this process. Histological and viability staining demonstrated that endosperm cell death was initiated earlier and progressed more rapidly in sh2 endosperm compared with Su endosperm. Internucleosomal DNA fragmentation accompanied endosperm cell death and occurred more extensively in sh2 endosperm. 1-Aminocyclopropane-1-carboxylic acid levels peaked approximately 16 d after pollination (dap) in Su endosperm and gradually decreased during subsequent development, whereas two large 1-aminocyclopropane-1-carboxylic acid peaks were observed in sh2 endosperm, the first between 16 and 20 dap and the second at 36 dap. Ethylene levels were elevated in sh2 kernels compared with Su kernels, with an initial peak 20 dap approximately 3-fold higher than in Su kernels and a second peak 36 dap approximately 5-fold higher than that in Su kernels. Ethylene treatment of Su kernels resulted in earlier and more extensive endosperm cell death and DNA fragmentation. Aminoethoxyvinylglycine treatment of sh2 kernels reduced the extent of DNA fragmentation. We conclude that ethylene is involved in triggering programmed cell death in developing maize endosperm and is responsible for the aberrant phenotype of sh2 kernels.

15.
Talanta ; 43(6): 889-99, 1996 Jun.
Article in English | MEDLINE | ID: mdl-18966559

ABSTRACT

Chemical analysis of surface active species (surfactants) is of interest for many applications, such as in process monitoring, biomedical applications, environmental monitoring and surface science investigations. Recently, we reported a dynamic surface tension detector (DSTD) based upon optically probing the size of a repeating drop resulting from constant flow of an aqueous solvent out of the end of a capillary. Presence of a surfactant in a growing drop reduces the surface tension at the air-solvent interface, causing the drop to detach at a smaller volume, which is detected. The DSTD has a kinetic dependence, and with increasing flow rate the sensitivity decreases due to diffusional and adsorption effects. We report that for the sodium salt of dodecylsulfate (DS), the DSTD performs significantly better with a stainless steel (S.S.) capillary dropper than with a fused silica dropper because the S.S. dropper exhibits a smaller adsorption effect as a function of time. Flow-injection analysis with the DSTD of DS was found to enhance sensitivity 50-fold by in-situ reaction with the ion-pair reagent tetrabutylammonium hydroxide (TBA) in water, even though the TBA alone was not very surface active. The TBA-DS system serves as a model for a selective detection method in which surface activity is exploited and enhanced. The detection limit for DS, as TBA-DS, was 400 ppb. Additionally, weakly surface active species such as TBA could be analyzed "indirectly" by ion-pair formation with DS. The enhanced sensitivity is due to increased packing of the ion-pairs at the air-aqueous solvent interface. The flow rate dependence on the sensitivity of detecting the TBA-DS ion-pair was examined. Two limiting conditions were observed as a function of ion-pair concentration: sensitivity decreases linearly with inverse flow rate at high flow rates and approaches a steady state at slower flow rates.

16.
J Chem Ecol ; 22(3): 513-39, 1996 Mar.
Article in English | MEDLINE | ID: mdl-24227490

ABSTRACT

Hexane extracts of leaves of 307 accessions from 73 host plant species ofHelicoverpa zea were analyzed by gas chromatography (GC) and used forH. zea oviposition and neonate larvae orientation bioassays. The gas chromatographic (GC) retention times of compounds statistically associated with behavioral activity were identified by correlation of GC peak area with oviposition and larval orientation preferences. Although taxonomically diverse in their origin, compounds for study were purified from extracts of species of the genusLycopersicon, due to their relative abundance. The structures of eight long-chain alkanes associated with oviposition preference were assigned by mass spectrometry, and the structures of five similarly associated organic acids and a terpenoid alkene were identified by(1)H and(13)C nuclear magnetic resonance spectroscopy. The structures of a number of other phytochemicals from the plant leaves were identified for comparative purposes, including a previously unknown terpene, 7-epizingiberene. Bioassays were performed on the isolated acids and on the alkane wax fractions of severalLycopersicon species, and significant differences were found in oviposition stimulation for both classes of compounds. Of the hundreds of compounds found in the extracts, none were observed to act as oviposition deterrents. The results of these bioassays may be useful in explaining the broad host range ofH. zea, as well as the process and evolution of host plant selection for oviposition.

17.
Plant Physiol ; 106(3): 929-39, 1994 Nov.
Article in English | MEDLINE | ID: mdl-7824660

ABSTRACT

Gene expression in the aleurone and endosperm is highly regulated during both seed development and germination. Studies of alpha-amylase expression in the aleurone of barley (Hordeum vulgare) have generated the current paradigm for hormonal control of gene expression in germinating cereal grain. Gene expression studies in both the aleurone and endosperm tissues of maize (Zea mays) seed have been hampered because of a lack of an efficient transformation system. We report here the rapid isolation of protoplasts from maize aleurone and endosperm tissue, their transformation using polyethylene glycol or electroporation, and the regulation of gene expression in these cells. Adh1 promoter activity was reduced relative to the 35S promoter in aleurone and endosperm protoplasts compared to Black Mexican Sweet suspension cells in which it was nearly as strong as the 35S promoter. Intron-mediated stimulation of expression was substantially higher in transformed aleurone or endosperm protoplasts than in cell-suspension culture protoplasts, and the data suggest that the effect of an intron may be affected by cell type. To examine cytoplasmic regulation, the 5' and 3' untranslated regions from a barley alpha-amylase were fused to the firefly luciferase-coding region, and their effect on translation and mRNA stability was examined following the delivery of in vitro synthesized mRNA to aleurone and endosperm protoplasts. The alpha-amylase untranslated regions regulated translational efficiency in a tissue-specific manner, increasing translation in aleurone or endosperm protoplasts but not in maize or carrot cell-suspension protoplasts, in animal cells, or in in vitro translation lysates.


Subject(s)
Gene Expression Regulation, Plant , Introns , Promoter Regions, Genetic , RNA, Messenger/metabolism , Transformation, Genetic , Zea mays/metabolism , Animals , CHO Cells , Cells, Cultured , Cricetinae , Hordeum/enzymology , Hordeum/genetics , Luciferases/analysis , Luciferases/biosynthesis , Protein Biosynthesis , Protoplasts/metabolism , RNA, Messenger/analysis , Rabbits , Reticulocytes/metabolism , Transfection , Zea mays/genetics , alpha-Amylases/biosynthesis
19.
Theor Appl Genet ; 87(8): 965-72, 1994 Mar.
Article in English | MEDLINE | ID: mdl-24190531

ABSTRACT

Three chromosomal segments from the wild tomato L. chmielewskii have been introgressed into the L. esculentum genome. Using molecular markers they have been mapped to the middle and terminal regions of chromosome 7 (7M, 7T respectively), and to the terminal region of chromosome 10 (10T). This study was conducted to further clarify the physiological influence of the introgressed segments of chromosome 7 and 10 on tomato soluble solids (SS), and other fruit and yield parameters. The effect of the 10T segment was evaluated using five lines that differ for the presence of this segment. As previously reported this segment increased fruit pH with no significant effect on SS. Sixty-four BC2F5 backcross inbred lines (BILs) were developed from a cross using LA1501 (an L. esculentum line that contains the 7M and 7T fragments from L. chmielewskii) as the donor parent, and VF145B-7879 (a processing cultivar) as the recurrent parent. BILs were classified in four groups (+ +, inbreds without either of the L. chmielewskii segments; 7M +, lines with only the 7M segment; + 7T, inbreds with only the 7T segment, and 7M7T, inbreds with both segments) based on RFLP information, and then compared to each other for all the parameters under study. Inbreds homoyzgous for the 7M fragment displayed greater SS (26%) and higher pH (0.10) than the control group (+ +). The 7L fragment did not influence either SS or pH, but was observed to significantly increase fruit yield by 12% when compared to the recurrent parent. A gene or genes that increase yield without affecting SS or pH may have potential in the development of commerical cultivars.

SELECTION OF CITATIONS
SEARCH DETAIL
...