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Gibson EM, Jones AC, Taylor AG, Bouwman WG, Phillips D, Sandell J. Laser-induced fluorescence spectroscopy of 4-aminobenzonitrile, 4-(N,N-dimethylamino)benzonitrile, and their van der Waals complexes in a supersonic jet. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100330a024] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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102
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Ma C, Kwok WM, Matousek P, Parker AW, Phillips D, Toner WT, Towrie M. Excited States of 4-Aminobenzonitrile (ABN) and 4-Dimethylaminobenzonitrile (DMABN): Time-resolved Resonance Raman, Transient Absorption, Fluorescence, and ab Initio Calculations. J Phys Chem A 2002. [DOI: 10.1021/jp012765e] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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103
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Gonzalez MH, Tarandy DI, Troy D, Phillips D, Weinzweig N. Free tissue coverage of chronic traumatic wounds of the lower leg. Plast Reconstr Surg 2002; 109:592-600. [PMID: 11818841 DOI: 10.1097/00006534-200202000-00028] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Thirty-eight consecutive patients who underwent 42 free flaps for chronic wounds of the lower leg were identified over an 11-year period. All wounds were open for a minimum of 1 month (mean, 40 months; median, 8 months; range, 1 month to 30 years). The average age was 37 years (range, 7 to 68 years), there were 31 male patients and seven female patients, and the average follow-up time was 30 months (range, 12 to 72 months). The original injury was an open fracture in 28 patients, wound dehiscence after open reduction and internal fixation of a closed fracture in nine patients, and a shrapnel wound in one patient. A total of 23 patients had osteomyelitis, which was classified as local (involving less than 50 percent of the bone diameter) in 15 patients and as diffuse (involving greater than 50 percent of the bone diameter or infected nonunion) in eight patients. The wounds were treated with sequential debridement, antibiotics, and flap coverage. Ancillary procedures included antibiotic beads in 18 patients, saucerization in 16, Ilizarov bone transport in three, calcanectomy in two, and fibular resection and ankle fusion in one. Thirty-four of 42 flaps survived, four having undergone a repeat free flap. There were three failures out of 25 flaps (12 percent) among those with a normal angiogram and five failures out of 15 flaps (33 percent) among those with an abnormal angiogram (p > 0.05). The failure rate of those with osteomyelitis was six of 26 (23 percent) versus two of 26 (13 percent) for those without osteomyelitis (p > 0.05). Successful reconstruction (bone healed, patient ambulatory and infection-free) was achieved in 33 of 38 patients (87 percent). The failure of reconstruction for those patients with osteomyelitis was four of 23 (22 percent) versus one of 15 (7 percent) for others (p > 0.05). The failure rate of flaps in patients with diffuse osteomyelitis was three of eight (38 percent) versus two of 30 for others (7 percent, p = 0.053). The presence of diffuse osteomyelitis was associated with a lower rate of successful limb reconstruction. An abnormal angiogram and the presence of osteomyelitis both were associated with a lower rate of successful limb reconstruction, but this was not significant, probably because of the small size of the cohort.
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104
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Garner MG, Whan IF, Gard GP, Phillips D. The expected economic impact of selected exotic diseases on the pig industry of Australia. REV SCI TECH OIE 2001; 20:671-85. [PMID: 11732410 DOI: 10.20506/rst.20.3.1303] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The authors assess the expected economic impact of three exotic diseases on the pig industry of Australia. An integrated epidemiological/economic approach was used to assess the effects of classical swine fever, Nipah virus and porcine reproductive and respiratory syndrome. Scenarios involving either an epidemic event, in which the outbreaks were confined to selected regions and were eradicated, or an endemic situation, in which the diseases became established in Australia, were studied. Based only on loss of sales and disposal costs, epidemics resulted in regional losses in income of the order of AUS$10 million-AUS$30 million (16%-37%) depending on disease and region. If any of these diseases became established, opportunity losses in gross national pig income of 5%-11% per year would occur, with classical swine fever the most serious of the three diseases. Establishment of any of the diseases would lead to rapid structural change in the pig industry, with concomitant social and economic dislocation in regional Australia.
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105
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Thomson TA, Hayes MM, Spinelli JJ, Hilland E, Sawrenko C, Phillips D, Dupuis B, Parker RL. HER-2/neu in breast cancer: interobserver variability and performance of immunohistochemistry with 4 antibodies compared with fluorescent in situ hybridization. Mod Pathol 2001; 14:1079-86. [PMID: 11706067 DOI: 10.1038/modpathol.3880440] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The immunohistochemistry (IHC) performance of 4 anti-HER-2/neu antibodies was compared with fluorescent in situ hybridization (FISH) analysis of HER-2/neu gene expression in breast cancer patients considered for Herceptin (Trastuzumab) therapy. Interobserver variability in IHC interpretation was measured. Formalin-fixed tissue was received from 24 provincial hospital laboratories. The following anti-Her-2 antibodies were used: DAKO A0485 (polyclonal), Novacastra CB11 (monoclonal), Zymed TAB250 (monoclonal), and DAKO HercepTest (polyclonal). Additional sections were analyzed by FISH (Vysis). Three pathologists blinded to FISH results independently interpreted invasive tumor cell membranous staining on a scale of 0 to +3. The HER-2/neu gene was considered amplified when the FISH signal ratio of HER-2/CEP-17 was > or =2.0. Blocks from all hospitals and of all ages were suitable for IHC and FISH analysis. No interlaboratory analysis variability was noted. The interobserver agreement (kappa) for stain intensity for each antibody was good for 0 and +3 but poor for +1 and +2. Reasonable concordance between IHC and FISH was found with three of the four antibodies. TAB250 was the most sensitive antibody. For the three pathologists, the IHC sensitivities and specificities compared with FISH using 0/+1 as negative and +2/+3 as positive were as follows: A0485, 63-84/95-98; CB11, 63-66/97-98; TAB-250, 82-100/94-95; HercepTest, 59-77/91-93. The positive and negative predictive values varied by stain intensity. Stain scores of 0 and +3 were highly predictive of gene status. Stain scores of +1 and +2 were not sufficiently predictive to classify cases as amplified versus nonamplified. IHC is a reasonable first test to assess HER-2/neu status in patients with breast cancer. For most cases, DAKO A0485, TAB250, and HercepTest adequately predicted gene status. In cases with stain intensity of +1 or +2, the interobserver agreement is poor, and the predictive value is unsatisfactory for clinical use. Additional testing, preferably with FISH, is recommended.
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106
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Winecker RE, Goldberger BA, Tebbett IR, Behnke M, Eyler FD, Karlix JL, Wobie K, Conlon M, Phillips D, Bertholf RL. Detection of cocaine and its metabolites in breast milk. J Forensic Sci 2001; 46:1221-3. [PMID: 11569568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
A method was developed for measuring cocaine and its metabolites, benzoylecgonine, ecgonine methyl ester, norcocaine, ecgonine ethyl ester, cocaethylene, and m-hydroxybenzoylecgonine, in breast milk by gas chromatography/mass spectrometry. Limits of detection for this method ranged from 2.5 to 10 ng/mL, and limits of quantitation ranged from 5 to 50 ng/mL. For each of the compounds measured by this method, linear response was demonstrated to 750 ng/mL. Breast milk was collected from 11 mothers who admitted to drug use during pregnancy and ten drug-free volunteers serving as control subjects. Cocaine was detected in six of the specimens obtained from drug-exposed subjects, and in none of the drug-free control subjects. In breast milk specimens where cocaine and one or more of its metabolites were detected, the concentration of parent compound was greater than any of the metabolites. The highest cocaine concentration found was over 12 microg/mL. Breast-fed infants of cocaine abusing mothers may be exposed to significant amounts of drug orally.
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107
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Ma C, Kwok W, Matousek P, Parker A, Phillips D, Toner W, Towrie M. Resonance Raman study of ring deuterated 4-dimethylaminobenzonitrile (DMABN-d4): the ground, ICT and triplet states. J Photochem Photobiol A Chem 2001. [DOI: 10.1016/s1010-6030(01)00512-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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108
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Oldham TC, Phillips D, MacRobert AJ. Attempts to measure sensitiser photophysics in opaque tissue. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2001; 61:129-36. [PMID: 11535412 DOI: 10.1016/s1011-1344(01)00176-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Diffuse reflectance laser flash photolysis has been used in an attempt to measure transient triplet spectra of the sensitisers, disulphonated aluminium phthalocyanine and porphyrin IX (derived from 5-amino laevulinic acid), in opaque tissue and models. The latter consisted of tissue phantoms; the former included rat liver and red blood cells. In all cases, triplet-triplet absorption spectra with relatively poor signal-to-noise were obtained providing some encouragement in the application of this technique to in vivo studies on photosensitisers.
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109
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Mukkun L, Singh Z, Phillips D. NITROGEN NUTRITION AFFECTS FRUIT FIRMNESS, QUALITY AND SHELF LIFE OF STRAWBERRY. ACTA ACUST UNITED AC 2001. [DOI: 10.17660/actahortic.2001.553.5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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110
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Collier J, MacKinlay D, Phillips D. Norm values for the Generic Children's Quality of Life Measure (GCQ) from a large school-based sample. Qual Life Res 2001; 9:617-23. [PMID: 11236852 DOI: 10.1023/a:1008915700210] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study aimed to assess the quality of life of a population sample of schoolchildren. The Generic Children's Quality of Life Measure (GCQ) has been developed to allow comparison between chronically ill children and the general child population. The measure assesses how the child views his or her life and also how they would like it to be. Quality of life is measured as the discrepancy between the two viewpoints. This large community-based survey aimed to establish GCQ norm values for children aged 6-14 years. The children were from a sample of schools stratified by geographical location and social need: rural affluent, rural low affluence, urban affluent and urban low affluence. 720 completed questionnaires were analysed. The scores were normally distributed with a wide range. The GCQ showed an acceptable reliability with a Cronbach's alpha of 0.75. The quality of life score was not correlated with age (r = -0.02, p = 0.64) nor with the deprivation score of the area in which the children lived (r = -0.026, p = 0.49). There were no significant differences between the scores by gender (p = 0.22) nor by rural/urban location (p = 0.60). Normative values were established. The GCQ is suitable for using with children over a large age range (6-14 years) without the scores being confounded by the age, gender, affluence or geographical location.
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111
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Abstract
A survey of the microbiological quality of beef carcasses and boneless beef produced in Australia was conducted during the period June to November 1998. Sponge samples were collected from 1,275 carcasses, and meat samples were drilled from 990 cartons of frozen boneless beef. Carcass and boneless beef samples were respectively collected from 21 and 27 establishments that concentrated on export and from 38 and 3 establishments supplying the Australian domestic market of which 31 were very small plants slaughtering no more than 150 cattle equivalents per week. The mean log total viable counts (TVCs) were 2.42/cm2 and 2.52/g for carcasses and boneless meat, respectively. Escherichia coli was detected on 10.3% of carcasses and 5.1% of boneless beef samples and coagulase-positive staphylococci on 24.3% of carcasses and 17.5% of boneless beef. Salmonella was detected on 0.2% of carcasses and 0.1% of boneless beef and E. coli O157:H7 recovered from 0.1% of carcasses but not detected on 990 boneless beef samples. Mean log TVCs/cm2 differed significantly (P < 0.05) between establishment types. They were lower on carcasses from export establishments (2.20) compared with domestic (2.61) and very small plants (3.10). There were no significant differences in prevalence of Salmonella or E. coli O157:H7 between establishment types. Excision samples were taken from 670 carcasses to make comparisons with the first baseline study of Australian meat, carried out in 1993 to 1994. While there were differences in sampling and microbiological techniques between the two studies that require detailed consideration, there were small but significant improvements in several microbiological criteria for carcasses and boneless meat.
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112
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Abstract
Microbiological quality of sheep carcasses and boneless sheep meat produced in Australia was surveyed during the period June to November 1998. Sponge samples were collected from 917 carcasses, and meat samples were drilled from 467 cartons of frozen boneless meat. Carcass and boneless meat samples were respectively collected from 7 and 10 establishments that concentrated on export, and from 36 and 5 establishments supplying the Australian domestic market of which 31 were very small plants slaughtering cattle and sheep but no more than 1,200 sheep equivalents per week. The mean log total viable counts were 3.55/cm2 and 3.30/g for carcasses and boneless meat, respectively. Escherichia coli was detected on 29.2% of carcasses and 24.5% of boneless meat samples and coagulase-positive staphylococci on 24.1% of carcasses, and 38.6% of boneless meat samples. Salmonella was detected on 0.1% of carcasses and 1.3% of boneless meat samples. E. coli O157:H7 was recovered from 0.7% of carcasses and 1.3% of boneless sheep meat. There were statistically significant differences between establishment types for some microbiological criteria, although there were no significant differences in prevalence of Salmonella or E. coli O157:H7 between establishment types. While there were differences in sampling and microbiological techniques between this study and another conducted in 1993 to 1994 that require detailed consideration, there were small but significant improvements in several microbiological criteria for boneless meat. While data that would allow for comparison of carcass data were not gathered, it is unlikely that improvements in the microbiological quality of boneless sheep meat could accrue without improvements to carcasses.
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113
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Ma C, Kwok WM, Matousek P, Parker AW, Phillips D, Toner WT, Towrie M. Time-Resolved Study of the Triplet State of 4-dimethylaminobenzonitrile (DMABN). J Phys Chem A 2001. [DOI: 10.1021/jp004497a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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114
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Raiwet C, Phillips D. A regional approach to continence management. THE CANADIAN NURSE 2001; 97:16-20. [PMID: 11865514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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115
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Hooper WC, El-Jamil M, Dilley A, Philipp C, Ellingsen D, Phillips D, Evatt BL. The relationship between the tissue plasminogen activator Alu I/D polymorphism and venous thromboembolism during pregnancy. Thromb Res 2001; 102:33-7. [PMID: 11323012 DOI: 10.1016/s0049-3848(01)00220-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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116
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Darcy A, Clothier H, Phillips D, Bakote'e B, Stewart T. Solomon Islands dengue seroprevalence study--previous circulation of dengue confirmed. PAPUA AND NEW GUINEA MEDICAL JOURNAL 2001; 44:43-7. [PMID: 12418677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Since there were no confirmed outbreaks of dengue on record an extensive search of available records and a seroprevalence study were undertaken to determine if there was evidence of past dengue virus infections in the Solomon Islands. Hospital and Health Department records revealed a suspected dengue outbreak in 1982 and deaths attributed to dengue in 1995 and 1996. Serum samples from blood donors were analyzed for the presence of IgG antibodies specific for flavivirus and dengue virus. A total of 39% of the 515 samples, predominantly from adult males from Honiara, demonstrated IgG antibodies specific for dengue; 28% (26 of 93) were monotypically positive by plaque reduction neutralization test for dengue 2 antibody and the remaining samples had antibodies to more than one dengue serotype. A good correlation was found between the presence of flavivirus and dengue IgG confirming that dengue virus had circulated in the past in the Solomon Islands.
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117
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118
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Kwok WM, Ma C, Matousek P, Parker AW, Phillips D, Toner WT, Towrie M, Umapathy S. A Determination of the Structure of the Intramolecular Charge Transfer State of 4-Dimethylaminobenzonitrile (DMABN) by Time-Resolved Resonance Raman Spectroscopy. J Phys Chem A 2001. [DOI: 10.1021/jp003705w] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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119
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Telli-Karakoç F, Gaines AF, Hewer A, Phillips D. Differences between blood and liver aromatic DNA adduct formation. ENVIRONMENT INTERNATIONAL 2001; 26:143-148. [PMID: 11341698 DOI: 10.1016/s0160-4120(00)00098-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Aromatic DNA adducts in the livers and blood of grey mullet (Mugil sp.) have been monitored between 1993 and 1996 by the isolation of DNA and the postlabeling of the DNA adducts with 32P. The grey mullet were sampled from three well-characterised harbours, two in the northeastern Mediterranean and one in the northeastern Black Sea near Trabzon close to a site of aquaculture. One of the northeastern Mediterranean harbours was highly polluted with polynuclear aromatic hydrocarbons (PAHs) and was rich in inorganic nutrients. Larger grey mullet lived in this harbour than the other harbours and their livers possessed approximately 100 aromatic DNA adducts per 10(8) nucleotides. The livers from grey mullet in the other two harbours possessed < or = 25 aromatic DNA adducts per 10(8) nucleotides but these concentrations depended on a variety of factors. Blood cell being regenerated more rapidly than liver cells, it is found that generally the ratio of DNA adduct concentrations in piscine liver and blood will increase with the pollution of the surrounding marine environment. Fishes are acceptable models for the metabolism of xenobiotics and the associated formation of harmful aromatic DNA adducts in organisms.
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120
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Kwok WM, Gould I, Ma C, Puranik M, Umapathy S, Matousek P, Parker AW, Phillips D, Toner WT, Towrie M. Vibrational studies of ground state 4-dimethylaminobenzonitrile (DMABN) and its ring deuterated isotopomer DMABN-d4. Phys Chem Chem Phys 2001. [DOI: 10.1039/b101291f] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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121
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Rusher AH, Davis K, Phillips D, Wiggins L. Open versus thoracoscopic removal of left-sided mid-esophageal leiomyoma. THE JOURNAL OF THE ARKANSAS MEDICAL SOCIETY 2001; 97:247-9. [PMID: 11189104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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122
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Phillips D, Adams G. Child care and our youngest children. THE FUTURE OF CHILDREN 2001; 11:34-51. [PMID: 11712454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Studies of child development confirm that experiences with people mold an infant's mind and personality. Caregiving is, therefore, central to development, whether the caregiver is a parent, a grandmother, or a teacher in a child care center. This article uses data from new, national studies of families to examine the state of child care for infants and toddlers. The story it tells is complex, as the authors outline the overlapping impacts that diverse child care settings and home situations have on children. Early exposure to child care can foster children's learning and enhance their lives, or it can leave them at risk for troubled relationships. The outcome that results depends largely on the quality of the child care setting. Responsive caregivers who surround children with language, warmth, and chances to learn are the key to good outcomes. Other quality attributes (like training and staff-to-child ratios) matter because they foster positive caregiving. Diversity and variability are hallmarks of the American child care supply. Both "wonderful and woeful" care can be found in all types of child care but, overall, settings where quality is compromised are distressingly common. Children whose families are not buoyed by good incomes or government supports are the group most often exposed to poor-quality care. Given this balanced but troubling look at the status of child care for infants and toddlers, the authors conclude that there is a mismatch between the rhetoric of parental choice and the realities facing parents of young children in the United States. They call on communities, businesses, foundations, and government to play a larger role in helping parents secure good care for their infants and toddlers.
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123
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Ghiggino KP, Roberts AJ, Phillips D. Time-resolved fluorescence spectroscopy using pulsed lasers. ACTA ACUST UNITED AC 2000. [DOI: 10.1088/0022-3735/13/4/019] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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124
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Tang D, Stampfer M, Phillips D, Perera F. Predictive value of PAH-DNA adducts for lung cancer risk in a nested case-control study. Lung Cancer 2000. [DOI: 10.1016/s0169-5002(00)80791-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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125
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McAllister JJ, Phillips D, Millhouse S, Conner J, Hogan T, Ross HL, Wigdahl B. Analysis of the HIV-1 LTR NF-kappaB-proximal Sp site III: evidence for cell type-specific gene regulation and viral replication. Virology 2000; 274:262-77. [PMID: 10964770 DOI: 10.1006/viro.2000.0476] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been widely demonstrated that the human immunodeficiency virus type 1 (HIV-1) envelope, specifically the V3 loop of the gp120 spike, evolves to facilitate adaptation to different cellular populations within an infected host. Less energy has been directed at determining whether the viral promoter, designated the long terminal repeat (LTR), also exhibits this adaptive quality. Because of the unique nature of the cell populations infected during the course of HIV-1 infection, one might expect the opportunity for such adaptation to exist. This would permit select viral species to take advantage of the different array of conditions and factors influencing transcription within a given cell type. To investigate this hypothesis, the function of natural variants of the NF-kappaB-proximal Sp element (Sp site III) was examined in human cell line models of the two major cell types infected during the natural course of HIV-1 infection, T cells and monocytes. Utilizing the HIV-1 LAI molecular clone, which naturally contains a high-affinity Sp site III, substitution of low-affinity Sp sites in place of the natural site III element markedly decreased viral replication in Jurkat T cells. However, these substitutions had relatively small effects on viral replication in U-937 monocytic cells. Transient transfections of HIV-1 LAI-based LTR-luciferase constructs into these cell lines suggest that the large reduction in viral replication in Jurkat T cells, caused by low-affinity Sp site III variants, may result from reduced basal as well as Vpr- and Tat-activated LTR activities in Jurkat T cells compared to those in U-937 monocytic cells. When the function of Sp site III was examined in the context of HIV-1 YU-2-based LTR-luciferase constructs, substitution of a high-affinity element in place of the natural low-affinity element resulted in increased basal YU-2 LTR activity in Jurkat T cells and reduced activity in U-937 monocytic cells. These observations suggest that recruitment of Sp family members to Sp site III is of greater importance to the function of the viral promoter in the Jurkat T cell line as compared to the U-937 monocytic cell line. These observations also suggest that other regions of the LTR may compensate for Sp recruitment defects in specific cell populations.
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MESH Headings
- Base Sequence
- Binding, Competitive
- Cells, Cultured
- Cloning, Molecular
- Consensus Sequence/genetics
- DNA/genetics
- DNA/metabolism
- Gene Expression Regulation, Viral
- Gene Products, tat/metabolism
- Gene Products, vpr/metabolism
- Genes, Reporter
- Genetic Variation/genetics
- HIV Long Terminal Repeat/genetics
- HIV-1/genetics
- HIV-1/physiology
- Humans
- Jurkat Cells
- Leukocytes, Mononuclear/virology
- Mutation/genetics
- NF-kappa B/metabolism
- Organ Specificity
- Promoter Regions, Genetic/genetics
- Response Elements/genetics
- Sp1 Transcription Factor/metabolism
- Transcriptional Activation
- U937 Cells
- Virus Replication
- tat Gene Products, Human Immunodeficiency Virus
- vpr Gene Products, Human Immunodeficiency Virus
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