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Powell CA, Pelosi RR, Rundell PA, Stover E, Cohen M. Cross-Protection of Grapefruit from Decline-Inducing Isolates of Citrus Tristeza Virus. PLANT DISEASE 1999; 83:989-991. [PMID: 30841297 DOI: 10.1094/pdis.1999.83.11.989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The ability of three mild isolates of citrus tristeza virus (CTV) to prevent natural infection of 84 Ruby Red grapefruit on sour orange rootstock by aphid-transmitted, decline-inducing isolates of CTV was assessed by symptoms and verified by enzyme-linked immunosorbent assay (ELISA) after 16 years. Of 21 trees in each of four treatments protected by the DD 102 bb, Guettler HS, and DPI 1-12-5-X-E mild CTV isolates, 14, 10, and 14% were infected by severe isolates (MCA13 monoclonal antibody reactive) compared with 67% for unprotected control trees. The health of trees protected by the DD 102 bb CTV isolate was significantly better than that of unprotected control trees as measured by decline, tree ratings, and tree height. These data suggest that infection by certain mild isolates of CTV can cross-protect grapefruit trees on sour orange rootstock from decline-inducing isolates of CTV that are prevalent in the Indian River region of Florida.
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Chang SM, Hutchinson SE, Powell CA, Walker SP. The nutritional status of rural Jamaican school children. W INDIAN MED J 1999; 48:112-4. [PMID: 10555453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Three thousand, eight hundred and eighty-two (3,882) children in grades 2-5, attending 16 rural primary and all-age schools in central Jamaica were weighed and their weight-for-age standard deviation scores calculated using the World Health Organization/National Center for Health Statistics (WHO/NCHS) references. Heights were also measured in a random sample of the grade 5 children (n = 793) and height-for-age and body mass index (BMI-kg/m2) calculated. Sixty-nine per cent of the total sample were of normal weight-for-age, 2% were moderately undernourished (weight-for-age > -3 Z-score, < or = -2 Z-score), and a further 24% mildly undernourished (weight-for-age > -2 Z-score, < or = -1 Z-score). Few children were overweight. The frequency distribution of weight-for-age was similar in girls and boys. In the subsample of children in whom heights were measured, 25.8% were < or = -1 Z-score height-for-age, and of these 4.9% were < -2 Z-score. Compared with a survey conducted in a similar rural area in the 1960s, the children's mean weights for age group categories were 1.1 to 3.7 kg heavier. Children who were older than appropriate for their grade were more likely to be undernourished (Odds ratio 3.94, 95% CI 3.21, 4.83), which suggests that undernourished children may be more likely to repeat a grade or start school later.
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Genschel U, Powell CA, Abell C, Smith AG. The final step of pantothenate biosynthesis in higher plants: cloning and characterization of pantothenate synthetase from Lotus japonicus and Oryza sativum (rice). Biochem J 1999; 341 ( Pt 3):669-78. [PMID: 10417331 PMCID: PMC1220405 DOI: 10.1042/0264-6021:3410669] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have isolated a Lotus japonicus cDNA for pantothenate (vitamin B(5)) synthetase (PS) by functional complementation of an Escherichia coli panC mutant (AT1371). A rice (Oryza sativum) expressed sequence tag, identified by sequence similarity to PS, was also able to complement the E. coli auxotroph, as was an open reading frame from Saccharomyces cerevisiae (baker's yeast). The Lotus and rice cDNAs encode proteins of approx. 34 kDa, which are 65% similar at the amino acid level and do not appear to encode N-terminal extensions by comparison with PS sequences from other organisms. Furthermore, analysis of genomic sequence flanking the coding sequence for PS in Lotus suggests the original cDNA is full-length. The Lotus and rice PSs are therefore likely to be cytosolic. Southern analysis of Lotus genomic DNA indicates that there is a single gene for PS. Recombinant PS from Lotus, overexpressed in E. coli AT1371, is a dimer. The enzyme requires d-pantoate, beta-alanine and ATP for activity and has a higher affinity for pantoate (K(m) 45 microM) than for beta-alanine (K(m) 990 microM). Uncompetitive substrate inhibition becomes significant at pantoate concentrations above 1 mM. The enzyme displays optimal activity at about 0.5 mM pantoate (k(cat) 0.63 s(-1)) and at pH 7.8. Neither oxopantoate nor pantoyl-lactone can replace pantoate as substrate. Antibodies raised against recombinant PS detected a band of 34 kDa in Western blots of Lotus proteins from both roots and leaves. The implications of these findings for pantothenate biosynthesis in plants are discussed.
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Powell CA, Klares S, O'Connor G, Brody JS. Loss of heterozygosity in epithelial cells obtained by bronchial brushing: clinical utility in lung cancer. Clin Cancer Res 1999; 5:2025-34. [PMID: 10473082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
To determine whether loss of heterozygosity (LOH) could be a useful diagnostic test for lung cancer, we evaluated LOH in cells obtained from bronchial brushings. Cells from radiographically normal and abnormal lungs were obtained from 55 patients undergoing diagnostic bronchoscopy. Among 38 patients with lung cancer, LOH was present in at least one chromosomal locus in 79%, whereas cytology was positive for malignant cells in 37%. LOH was not restricted to the airway containing the tumor; fifty-three percent of the cancer patients had LOH in the contralateral lung, as did 59% of patients without lung cancer. There was an association between the extent of LOH and proximity to the cancer. The LOH score, which combined measures of fractional allelic loss and percentage of cells with allelic loss, was greater in subjects with positive cytology and on the side of the tumor. A LOH score >10 was positive in 58% of tumor-bearing lungs, in 13% of the contralateral lungs in cancer patients, and in no patients without cancer. Our results suggest that extensive and widespread allelic loss, as indicated by a high LOH score, may be diagnostic of lung cancer. Additional studies will be needed to clarify the clinical potential of using bronchial epithelial cell LOH as a biomarker and diagnostic test for lung cancer.
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Powell CA, Walker SP, Chang SM, Grantham-McGregor SM. Nutrition and education: a randomized trial of the effects of breakfast in rural primary school children. Am J Clin Nutr 1998; 68:873-9. [PMID: 9771865 DOI: 10.1093/ajcn/68.4.873] [Citation(s) in RCA: 125] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Hunger during school may prevent children in developing countries from benefiting from education. Although many countries have implemented school feeding programs, few programs have been rigorously evaluated. We conducted a randomized, controlled trial of giving breakfast to undernourished and adequately nourished children. The undernourished group comprised 407 children in grades 2-5 in 16 rural Jamaican schools (weights-for-age < or = -1 SD of the National Center for Health Statistics references) and the adequately nourished group comprised 407 children matched for school and class (weights-for-age >-1 SD). Both groups were stratified by class and school, then randomly assigned to breakfast or control groups. After the initial measurements, breakfast was provided every school day for 1 school year. Children in the control group were given one-quarter of an orange and the same amount of attention as children in the breakfast group. All children had their heights and weights measured and were given the Wide Range Achievement Test before and after the intervention. School attendance was taken from the schools' registers. Compared with the control group, height, weight, and attendance improved significantly in the breakfast group. Both groups made poor progress in Wide Range Achievement Test scores. Younger children in the breakfast group improved in arithmetic. There was no effect of nutritional group on the response to breakfast. In conclusion, the provision of a school breakfast produced small benefits in children's nutritional status, school attendance, and achievement. Greater improvements may occur in more undernourished populations; however, the massive problem of poor achievement levels requires integrated programs including health and educational inputs as well as school meals.
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Walker SP, Powell CA, Hutchinson SE, Chang SM, Grantham-McGregor SM. Schoolchildren's diets and participation in school feeding programmes in Jamaica. Public Health Nutr 1998; 1:43-9. [PMID: 10555530 DOI: 10.1079/phn19980007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To describe food consumption during the school day of rural Jamaican children and participation in two government school feeding programmes. To determine factors which were related to these. DESIGN Cross sectional. SETTING 16 primary schools in rural Jamaica. SUBJECTS 415 children in grades 2 and 5 (ages 7 and 10 years). RESULTS Consumption of sweets, sweet drinks and snacks was high. Mean intakes at lunch were: energy 1537 kJ (SD 756), protein 10.4 g (SD 7.6) and iron 1.5 mg (SD 1.2). The mean energy intake was 17-20% of the daily requirement for this age group. Two types of school feeding programmes were available in the schools, one provided a cooked meal and the other a bun and milk. Median availability of school meals (as a percentage of children enrolled in the schools) over three terms was 24.6% (range 0-85.4%). Twenty per cent of the children participated in one or other programme. Poorer children were more likely to participate in the bun and milk programme (odds ratio 2.1, 95% CI 1.3-3.5) but children with more money to purchase food participated in the more costly cooked meal programme (odds ratio 2.4, 95% CI 1.3-4.6). CONCLUSIONS Energy intakes at lunch in Jamaican children were somewhat below optimal levels and the reliance on sweets and snacks is an area of concern. Programme characteristics such as meal cost, may affect access to school feeding by poor children.
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Powell CA, Pelosi RR, Sonoda RM, Lee RF. A Psorosis-Like Agent Prevalent in Florida's Grapefruit Groves and Budwood Sources. PLANT DISEASE 1998; 82:208-209. [PMID: 30856801 DOI: 10.1094/pdis.1998.82.2.208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Rio Grande Gummosis (RGG) is one of the most serious diseases of grapefruit in the Indian River region of Florida. Experiments were conducted to determine if a graft-transmissible agent was associated with this disease in commercial grapefruit, and if any such agent was present in scion sources used for grapefruit propagation. Indexing data from indicators revealed that 79% and 31% of the commercial grapefruit and scion trees, respectively, contained a psorosis-like agent (PLA). The PLA was present in both RGG-affected and symptomless trees. We conclude that Florida's grapefruit propagation sources are contaminated with a PLA that is now widespread in commercial plantings.
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Duan YP, Powell CA, Purcifull DE, Broglio P, Hiebert E. Phenotypic variation in transgenic tobacco expressing mutated geminivirus movement/pathogenicity (BC1) proteins. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 1997; 10:1065-74. [PMID: 9390421 DOI: 10.1094/mpmi.1997.10.9.1065] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Tobacco plants were transformed with the movement protein (pathogenicity) gene (BC1) from tomato mottle geminivirus (TMoV), using Agrobacterium-mediated transformation. Different transgenic tobacco lines that expressed high levels of the BC1 protein had phenotypes ranging from plants with severe stunting and leaf mottling (resembling geminivirus symptoms) to plants with no visible symptoms. The sequence data for the BC1 transgene from the transgenic plants with the different phenotypes indicated an association of spontaneously mutated forms of the BC1 gene in the transformed tobacco with phenotype variations. One mutated transgene associated with an asymptomatic phenotype had a major deletion at the C terminus of 119 amino acid residues with a recombination resulting in the addition of 26 amino acid residues of unidentified origin. This asymptomatic, mutated BC1 attenuated the phenotypic expression of the symptomatic BC1 in a tobacco line containing both copies of the BC1 gene. Another mutated form of the BC1 gene amplified from an asymptomatic, multicopy transgenic tobacco plant did not induce symptoms when transiently expressed in tobacco via a virus vector. The symptom attenuation in the transgenic tobacco by the asymptomatic BC1 may involve trans-dominant negative interference.
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Hutchinson SE, Powell CA, Walker SP, Chang SM, Grantham-McGregor SM. Nutrition, anaemia, geohelminth infection and school achievement in rural Jamaican primary school children. Eur J Clin Nutr 1997; 51:729-35. [PMID: 9368806 DOI: 10.1038/sj.ejcn.1600473] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To determine whether nutritional status, anaemia and geohelminth infections were related to school achievement and attendance in Jamaican children. DESIGN A cross-sectional study using a randomly selected sample. SUBJECTS Eight hundred children aged 9-13 y randomly selected from those enrolled in grade 5 in 16 primary schools in rural Jamaica. RESULTS The mean height-for-age of the children was -0.37 z-score +/- 1.0 s.d. with 4.9% having heights-for-age < -2 s.d. of the NCHS references. Anaemia (Hb < 11 g/dl) was present in 14.7% of the children, 38.3% were infected with Trichuris trichiura and 19.4% with Ascaris lumbricoides. Achievement levels on the Wide Range Achievement Test were low, with children performing at grade 3 level. In multilevel analyses, controlling for socioeconomic status, children with Trichuris infections had lower achievement levels than uninfected children in spelling, reading and arithmetic (P < 0.05). Children with Ascaris infections had lower scores in spelling and reading (P < 0.05) Height-for-age (P < 0.01) was positively associated with performance in arithmetic. Ascaris infection (P < 0.001) and anaemia (P < 0.01) predicted poorer school attendance. CONCLUSION Despite mild levels, undernutrition and geohelminth infections were associated with achievement, suggesting that efforts to increase school achievement levels in developing countries should include strategies to improve the health and nutritional status of children.
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Nikolaeva OV, Karasev AV, Powell CA, Garnsey SM, Lee RF. Modulation of the antigenic reactivity of the citrus tristeza virus coat protein. J Immunol Methods 1997; 206:97-105. [PMID: 9328572 DOI: 10.1016/s0022-1759(97)00093-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Trapping properties of a panel of monoclonal antibodies (Mabs) raised against citrus tristeza virus (CTV) were analyzed in an indirect double-antibody sandwich ELISA (I-DAS-ELISA). These antibodies had been previously assigned by serological specificity into five groups (I to V). Mabs from group V, which are directed to conformational epitopes, trapped significant amounts of virus antigen from CTV-infected plant tissue at IgG concentration above 10 ng/ml. Mabs from groups I to IV, which are directed to linear, continuous epitopes, performed poorly as coating antibodies, even at a 1 microgram/ml concentration of the IgG's, indicating that the respective linear epitopes were inaccessible. However, when Mabs from groups I to IV were combined with a small amount of Mabs from group V, a substantial increase in trapping of the CTV antigen was recorded. In this 'two antibody-binding assay' previously cryptic, linear epitopes of the CTV CP apparently became accessible to the Mabs from groups I to IV. Modulation of the antigenic reactivity of the CTV CP was also recorded upon binding of the Mabs directed to the conformational epitopes in solution. Induced exposure of the linear epitopes of the CTV CP was revealed in 'two antibody-binding assays' with pairwise combinations of different mouse Mabs and several rabbit and chicken polyclonal antisera with different serological specificities, including antisera to bacterially expressed CP fragments. This mixed coating in I-DAS-ELISA resulted in substantially increased efficiency of the virus antigen trapping by antisera produced against bacterially expressed protein fragments and an increased sensitivity of the CTV detection after optimization of the ratio between conformational and linear antibodies.
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Grantham-McGregor SM, Walker SP, Chang SM, Powell CA. Effects of early childhood supplementation with and without stimulation on later development in stunted Jamaican children. Am J Clin Nutr 1997; 66:247-53. [PMID: 9250101 DOI: 10.1093/ajcn/66.2.247] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It is not known whether nutritional supplementation in early childhood has long-term benefits on stunted children's mental development. We followed up 127 7-8-y old children who had been stunted in early childhood and received supplementation, stimulation, or both. At 9-24 mo of age, the children had been randomly assigned to four treatment groups: nutritional supplementation, stimulation, both treatments, and control. After 2 y, supplementation and stimulation had independent benefits on the children's development and the effects were additive. The group receiving both treatments caught up to a matched group of 32 nonstunted children. Four years after the end of the 2-y intervention 97% of the children were given a battery of cognitive function, school achievement, and fine motor tests. An additional 52 nonstunted children were included. Factor analyses of the test scores produced three factors: general cognitive, perceptual-motor, and memory. One, the perceptual-motor factor, showed a significant benefit from stimulation, and supplementation benefited only those children whose mothers had higher verbal intelligence quotients. However, each intervention group had higher scores than the control subjects on more tests than would be expected by chance (supplemented and both groups on 14 of 15 tests, P = 0.002; stimulated group in 13 of 15 tests, P = 0.01), suggesting a very small global benefit. There was no longer an additive effect of combined treatments at the end of the intervention. The stunted control group had significantly lower scores than the nonstunted children on most tests. Stunted children's heights and head circumferences on enrollment significantly predicted intelligence quotient at follow-up.
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Young JN, Bacaner TJ, Powell CA. Preperitoneal suprahepatic pacemaker generator placement in the pediatric population. Ann Thorac Surg 1997; 63:1486-8. [PMID: 9146359 DOI: 10.1016/s0003-4975(96)01398-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have used a preperitoneal suprahepatic location for pacemaker generator placement in pediatric patients requiring permanent pacemakers with epicardial leads. The technique is rapid, simple, and safe, and cosmesis is excellent, making this approach particularly advantageous in the younger infant and neonate.
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Powell CA, Pelosi RR, Bullock RC. Natural Field Spread of Mild and Severe Isolates of Citrus Tristeza Virus in Florida. PLANT DISEASE 1997; 81:18-20. [PMID: 30870939 DOI: 10.1094/pdis.1997.81.1.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The effectiveness of five different aphid control regimes in delaying movement of mild and severe isolates of citrus tristeza virus (CTV) into a CTV-free sweet orange scion on sour orange rootstock block was monitored annually for 5 years, using severe isolate-specific and isolate-nonspecific monoclonal antibodies. The average percentage of trees infected with a severe isolate of CTV was 32, 32, 20, 25, and 28 for trees treated with Temik, Temik + Meta-Systox R (MSR), MSR, stylet oil, or no aphid control, respectively, at the conclusion of the experiment (5 years). These percentages were not significantly different (P ≤ 0.05). The average percentage of trees infected only with mild isolates was 13, 10, 7, 7, and 17 for the above treatments, respectively. The infection with mild isolates was significantly greater (P ≤ 0.05) with no aphid control than with stylet oil or MSR treatments.
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Walker SP, Grantham-McGregor SM, Himes JH, Powell CA, Chang SM. Early childhood supplementation does not benefit the long-term growth of stunted children in Jamaica. J Nutr 1996; 126:3017-24. [PMID: 9001369 DOI: 10.1093/jn/126.12.3017] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The long-term benefits of early childhood supplementation and the extent to which catch-up growth occurs following linear growth retardation remain controversial. Stunted children (height-for-age < -2 SD of NCHS references, n = 122) recruited from a survey of poor neighborhoods in Kingston, Jamaica, participated in a 2-yr randomized, controlled trial of supplementation beginning at ages 9-24 mo. A group of 32 non-stunted children from the same neighborhoods was also followed. Four years after the intervention ended, when children were 7 to 8 y old, there were no effects of supplementation on any anthropometric measure. From the end of the trial until follow-up, the children who had been supplemented gained 1.2 cm less (P < 0.05) than the non-supplemented children, approximately the same amount as they had gained during the trial compared with the non-supplemented children. After adjustment for regression to the mean, the height-for-age of stunted children (supplemented and non-supplemented combined) increased from enrollment to follow-up by 0.31 Z-score (95% CI 0.17, 0.46). The height-for-age of the non-stunted children also increased (0.96 Z-score; 95% CI 0.70, 1.22). Our results suggest that some catch-up growth is possible even when children remain in poor environments. Long-term benefits of supplementation to growth may not be achieved when intervention begins after age 12 mo in children who have already become undernourished.
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Walker SP, Grantham-McGregor SM, Himes JH, Powell CA. Relationships between wasting and linear growth in stunted children. Acta Paediatr 1996; 85:666-9. [PMID: 8816200 DOI: 10.1111/j.1651-2227.1996.tb14120.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Height-for-age and weight-for-height are commonly used indicators of nutritional status; however, their precise interrelationship remains unclear. We examined the relationship between weight-for-height and linear growth in 127 stunted Jamaican children aged 9-24 months. The children were measured every 6 months over a 2-year period. The initial weight-for-height status was positively associated with linear growth in the following 6-month interval. The change in weight-for-height in the preceding interval was a better predictor of linear growth in the next interval than attained weight-for-height at the beginning of the interval. The results suggest that variations in weight-for-height may influence the rate of linear growth.
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Meeks Gardner J, Grantham-McGregor SM, Chang SM, Himes JH, Powell CA. Activity and behavioral development in stunted and nonstunted children and response to nutritional supplementation. Child Dev 1995; 66:1785-97. [PMID: 8556899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
It is frequently assumed that undernutrition in young children leads to poor development through reduced activity. 3 groups of 26 1-year-old stunted children were studied: nutritional supplementation, supplementation with psychosocial stimulation, and controls. 26 nonstunted comparison children were also studied. Activity levels were measured by extensive observation in the homes, and development using 4 subscales of the Griffith's Mental Development Scales. Initially, stunted children were less active than nonstunted ones (p < .01), but after 6 months they caught up regardless of treatment. The mental ages of the stunted children were lower than those of the nonstunted children initially, and improved with either treatment. Initially, activity levels made a significant contribution to the variance in the locomotor subscale only, but not 6 months later. Activity did not predict change in development over 6 or 12 months, nor did change in activity over 6 months predict change in development over 12 months.
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Powell CA, Walker SP, Himes JH, Fletcher PD, Grantham-McGregor SM. Relationships between physical growth, mental development and nutritional supplementation in stunted children: the Jamaican study. Acta Paediatr 1995; 84:22-9. [PMID: 7734894 DOI: 10.1111/j.1651-2227.1995.tb13479.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The relationship between physical growth and change in mental development on the Griffiths mental development scales was investigated in 127 stunted Jamaican children over a 2-year period. The role of nutritional supplementation in this relationship was examined. There were no consistent associations between changes in weight-for-height or head circumference and developmental change. Height gain over 2 years was significantly associated with change in mental age, and locomotor and hearing and speech subscale scores. Height gain in the first year predicted change in mental age, and hearing and speech in the second year. Some of the effect of supplementation on development was shared with linear growth. Therefore, nutrition probably explains part of the relationship between growth and development. However, supplementation also had effects on development independent of growth. The benefits of supplementation on development and the extent to which they were shared with growth varied among the subscales.
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Wong MS, Simeon DT, Powell CA, Grantham-McGregor SM. Geohelminth infections in school-aged children in Jamaica. W INDIAN MED J 1994; 43:121-2. [PMID: 7900373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
There is concern that geohelminthiasis may adversely affect the growth and development of children. The relevance of this in the Caribbean is unclear since in many territories the prevalence of geohelminths is unknown. We report the results of three surveys conducted in Jamaican primary schools located in areas at high risk for geohelminthiasis. The first was conducted in 12 Kingston schools and comprised children in grades 2 to 5 (aged 7 to 10 years). The second and third surveys were conducted in rural areas with children in grades 2 to 5 and grades 4 and 5, respectively. Overall, 9244 children provided stool samples for analysis. The prevalence of Trichuris trichiura ranged from 42% to 47% among the surveys while that for Ascaris lumbricoides ranged from 15% to 37%. Children in grades 2 and 3 had lower T. trichiura prevalences than those in grades 4 and 5 in the first and second surveys (p < 0.05 and p < 0.005, respectively). In the second survey only, children in grades 2 and 3 had a lower prevalence of A. lumbricoides than those in grades 4 and 5 (p < 0.005). Most infections were light with approximately 1% of the sample having heavy egg densities.
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Powell CA, Bollinger GA, Chapman MC, Sibol MS, Johnston AC, Wheeler RL. A seismotectonic model for the 300-kilometer-long eastern tennessee seismic zone. Science 1994; 264:686-8. [PMID: 17737953 DOI: 10.1126/science.264.5159.686] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Ten years of monitoring microearthquakes with a regional seismic network has revealed the presence of a well-defined, linear zone of seismic activity in eastern Tennessee. This zone produced the second highest release of seismic strain energy in the United States east of the Rocky Mountains during the last decade, when normalized by crustal area. The data indicate that seismicity produced by regional, intraplate stresses is now concentrating near the boundary between relatively strong and weak basement crustal blocks.
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Borovsky D, Powell CA, Nayar JK, Blalock JE, Hayes TK. Characterization and localization of mosquito-gut receptors for trypsin modulating oostatic factor using a complementary peptide and immunocytochemistry. FASEB J 1994; 8:350-5. [PMID: 7908271 DOI: 10.1096/fasebj.8.3.7908271] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The gut receptor of trypsin-modulating oostatic factor (TMOF), a decapeptide hormone that regulates trypsin biosynthesis in the mosquito gut, has been characterized. The binding of TMOF to mosquito gut membranes reached maximum at pH 7.4 and 24 degrees C. No binding was observed at pH 2.5 and the binding to the membranes declined rapidly at pH 8.0. At equilibrium, maximum binding to the receptor was observed at 60 min and 24 degrees C. A synthetic complementary decapeptide NH2-Ile-Leu-Gly-Arg-Gly-Gly-Gly-Gly-Gly-Gly-COOH (FOMT) for TMOF successfully competed with the gut receptor, and specifically bound TMOF (Kd = 4 microM and Kassoc = 2.5 x 10(5) M-1). TMOF binding to gut membranes was characterized with FOMT and a specific ELISA to the hormone at 24 and 72 h after blood feeding. Two classes of binding sites were found on the gut membrane; high affinity (Kd1 = 4.6 +/- 0.7 x 10(-7) M; Kassoc = 2.2 x 10(6) M-1 Bmax = 0.1 pmol/gut) and low affinity (Kd2 = 4.43 +/- 1 x 10(-6) M; Kassoc = 2.3 x 10(5) M-1; Bmax = 0.2 pmol/gut). The total binding sites for high and low affinity classes of TMOF per gut were estimated as 6.3 x 10(10) and 1.1 x 10(11) sites, respectively. Specific binding sites on the gut increased after the blood meal and were visualized by immunocytochemical staining. These results suggest that TMOF regulates trypsin biosynthesis by binding to specific receptor sites that are located on the mosquito gut, and that this receptor can be studied using a complementary peptide approach.
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Simeon DT, Grantham-McGregor SM, Walker SP, Powell CA. Effects of a hurricane on growth and morbidity in children from low-income families in Kingston, Jamaica. Trans R Soc Trop Med Hyg 1993; 87:526-8. [PMID: 8266401 DOI: 10.1016/0035-9203(93)90073-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
This is the first report of the effects of a hurricane on children's health and nutritional status in which data were available preceding and following the event. When Hurricane Gilbert struck Jamaica in 1988, a longitudinal study was in progress in which children's weights and heights were recorded every 2 months and their morbidity histories taken every week. The investigation included 127 stunted (low height-for-age) and 32 non-stunted children aged 23-44 months, living in poor areas of Kingston. The data from the 4 months before and after the hurricane were compared. There was an increase in the occurrence of respiratory symptoms including rapid or difficult breathing (P < 0.04), coughs (P < 0.001) and nasal discharges (P < 0.001) during the first 2-month period after the hurricane. However there was no significant effect on the occurrence of diarrhoea and injuries. Deficits were also found in height gain (P < 0.001) during the same period. These adverse effects were found in spite of the large amount of food aid received and the aggressive health education programme implemented after the hurricane.
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Grantham-McGregor SM, Walker SP, Himes JH, Powell CA. The effect of nutritional supplementation and stunting on morbidity in young children: the Jamaican study. Trans R Soc Trop Med Hyg 1993; 87:109-13. [PMID: 8465379 DOI: 10.1016/0035-9203(93)90448-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Infection and undernutrition in young children are thought to act synergistically. However, studies of the relationship between low height-for age (stunting) and morbidity in young children have had inconsistent findings and there are few adequate data on the effects of nutritional supplementation on morbidity. 129 stunted and 21 non-stunted children aged between 9 and 24 months, from poor Kingston neighbourhoods, identified from a house-to-house survey, were studied. The stunted children were randomly assigned to supplementation or no supplementation. Every week for 24 months the mothers were asked about the occurrence of any symptoms of illness. Supplementation had no consistent effect on the incidence or duration of symptoms. The stunted children had significantly more attacks of diarrhoea, fever, anorexia and apathy than the non-stunted children. The differences remained after controlling for social background and previous attacks of diarrhoea. There was also some indication of more severe illness in the stunted than in the non-stunted children.
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Walker SP, Grantham-McGregor SM, Powell CA, Himes JH, Simeon DT. Morbidity and the growth of stunted and nonstunted children, and the effect of supplementation. Am J Clin Nutr 1992; 56:504-10. [PMID: 1503061 DOI: 10.1093/ajcn/56.3.504] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Children aged 9-24 mo were recruited by a survey of poor areas of Kingston, Jamaica. Stunted children were randomly assigned to supplementation or not. Weekly morbidity histories were taken for 2 y. Separate multiple regressions on each symptom for weight or length gain in 2-mo intervals showed significant reductions in weight gain with coughing, apathy, anorexia, diarrhea, and fever, ranging from -2.1 to -16.8 g/d ill. Apathy and diarrhea reduced gains in length (-0.26 and -0.20 mm/d ill). Significant reductions in linear growth with lower respiratory-tract infections (-0.16 mm/d ill) occurred only in nonsupplemented children. Growth over 4-mo intervals was reduced if diarrhea occurred in the first 2 mo of the interval but there were no long-term effects of apathy, fever, or anorexia. Some of the effects of morbidity on growth were therefore transient and morbidity is unlikely to be a major cause of growth retardation in this population.
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Walker SP, Robinson RD, Powell CA, Grantham-McGregor SM. Stunting, intestinal parasitism and the home environment. Trans R Soc Trop Med Hyg 1992; 86:331-2. [PMID: 1412670 DOI: 10.1016/0035-9203(92)90337-c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Walker SP, Powell CA, Grantham-McGregor SM, Himes JH, Chang SM. Nutritional supplementation, psychosocial stimulation, and growth of stunted children: the Jamaican study. Am J Clin Nutr 1991; 54:642-8. [PMID: 1897471 DOI: 10.1093/ajcn/54.4.642] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The benefits of nutritional supplementation, with or without psychosocial stimulation, on the growth of stunted children were evaluated. Children aged 9-24 mo with lengths less than -2 SD of the National Center for Health Statistics references (n = 129) were randomly assigned to four groups: control, nutritional supplementation, stimulation, and both interventions. A fifth group with lengths greater than -1 SD was also enrolled. Length, weight, head and arm circumferences, and triceps and subscapular skinfold thicknesses were measured on enrollment and 6 and 12 mo later. Multiple-regression analysis was used to determine the effects of the interventions in which age, sex, initial status, initial dietary intake, and several socioeconomic variables were controlled for. Stimulation had no effect on growth and there was no interaction between the interventions. After 12 mo supplemented children had significantly increased length, weight, and head circumference (all P less than 0.01). The effects of supplementation were not cumulative but occurred in the first 6 mo.
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