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While the existence of chimeric cells in host tissue following organ transplantation is well documented, its distribution, temporal evolution and relationship to allograft survival is less clear. To explore this phenomenon, Lewis recipients of ACI cardiac allografts representing a wide range of immunosuppressive protocols and graft survival times were examined for the presence of chimerism using a sensitive polymerase chain reaction assay. Four groups of animals were examined: untransplanted animals receiving donor specific transfusion (DST)/cyclosporine A (CsA); allograft recipients with no treatment; recipients treated with DST/CsA/supplementary immunosuppression with rejection at 21-183 days; and recipients sacrificed with functioning allografts, treated with DST/CsA/supplementary immunosuppression and surviving > 200 days. To elucidate variations in the tissue distribution of chimeric cells, bone marrow, skin, liver, spleen, and thymus were examined in each animal. Untransplanted animals receiving DST/CsA displayed no evidence of chimerism. In animals receiving a cardiac allograft but no treatment, there was extensive evidence of chimerism in four of five animals. Chimerism was also detected in seven of nine animals with intermediate graft survival at the time of rejection. In animals with long-term graft survival, only four of eight displayed chimerism. These results suggest that, without immunosuppression, early chimerism does not lead to prolonged graft survival and that, even when graft survival is moderately prolonged, these cells are not sufficient to prevent rejection. In conclusion, chimerism appears to be a common phenomenon following transplantation, is not a result of DST, and may not be necessary for maintenance of long-term graft survival.  相似文献   

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"Ethnic cleavage among preschool children was studied using various test situations where choices of associates could be observed. It was found that ethnic cleavage does exist when choices are made significant to young children. The results are compared with other related findings and attempts are made to explain them theoretically." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Developmental research has generally not found evidence of helpless responses to failure in young children; a prevailing view is that young children lack the cognitive prerequisite for helplessness. However, recent evidence suggests that even preschoolers are vulnerable to helplessness in some situations. In the present study with 4- and 5-year-olds, we tested a goal-confidence model that predicts achievement behavior during failure for older children. We first categorized preschoolers' orientations toward "learning" or "performance" goals based on their preference for a challenging or nonchallenging task. As for older children, goal orientation was independent of ability and predicted cognitions and emotions during failure. Further, consistent with the model, within a learning goal, children displayed the mastery-oriented pattern regardless of confidence level, whereas within a performance goal, children with low confidence were most susceptible to helplessness. These behavior patterns were found on a second task as well. Thus, our findings show that individual differences in achievement goals emerge very early.  相似文献   

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Investigated differences in loneliness involving parents and peers and the relations between loneliness, choices of a "first comfort figure" (FCF), and social sensitivity as perceived by peers. 60 female and 52 male 5th graders, 97 female and 45 male 7th graders, and 66 female and 73 male 9th graders were given a loneliness scale and a sociometric measure of perceived social sensitivity. Results indicate that age differences in parent-related loneliness were marginally significant. Seventh graders seemed to have fewer loneliness experiences in their relationships with parents than 5th and 9th graders. Boys more frequently reported those feelings than girls. Ss who indicated both parents as their FCFs had the lowest scores for parent-related loneliness, whereas those who indicated friends as their FCFs had the highest scores for parent-related loneliness. With respect to peer-related loneliness, no age or sex differences were found. However, girls who chose both parents as their FCFs were more lonely than boys who did the same, and boys who chose their fathers as their FCFs mentioned more peer-related loneliness feelings than the girls who made this choice. Ss perceived as socially sensitive by their classmates less frequently mentioned peer-related loneliness feelings. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Behavior problems among young children in low-income urban day care centers   总被引:1,自引:0,他引:1  
The purposes of this study were to describe: (a) the frequency and correlates of behavior problems among a sample of 2- and 3-year-old children from low-income families as seen by their parents and day care teachers, (b) the degree to which parents and teachers agree about the children's behavior problems in their respective contexts, and (c) family characteristics that distinguish toddlers with behavior problems both at home and at day care from the rest of the sample. Parents of 133 toddlers from 10 Chicago day care centers completed measures of child behavior problems, child behavioral intensity, parenting self-efficacy, discipline strategies, and stress. Children's day care teachers also completed a measure of child behavior problems. Parent-reported behavior problems were associated with higher child behavioral intensity, greater parent stress, lower self-efficacy, and discipline strategies characterized by irritability, coercion, and inconsistency. Parent and teacher ratings on child behavior were correlated for boys' behavior problems only. Parents reported more child behavior problems than teachers. Approximately 8% of the children were rated as having behavior problems at home and at day care. Although most of the children are functioning well, many of these parents and toddlers are engaged in highly stressful and coercive relationships.  相似文献   

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Children who begin kindergarten with stronger skills learn faster than do those who enter with lower skills. Minority children tend to enter kindergarten already at a disadvantage, and the gap widens across time. However, little is known about cognitive development among American Indian young children. In this study, 110 American Indian infants from one Northern Plains reservation community were assessed four times between ages 6 months and 36 months, with the Mullen Scales of Early Learning. At 6 months of age, scores were near the national norms; a drop occurred between 6 months and 15 months. Scores then tended to level off below the norms through 36 months. In each domain, we observed a crucial decline over the 1st year of life and relatively little change in the 2nd and 3rd years of life, highlighting the importance of developing culturally syntonic interventions to facilitate cognitive development during the 1st year of life. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

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Reports an error in the original article by W. E. Lambert and Y. Taguchi (Journal of Abnormal & Social Psychology, 1956, 53, 380-382). The table presented here should be substituted for Table 1 (p. 381), and one p value, for Picture-Taking Choices, has been corrected. The tests were one-tailed since there was no apriori ground for expecting out-group preferences. Confusions of interpretation may arise from a reading of the original Table 1. The original table implies that the test is being made on the null hypothesis that in-group choice is independent of the ethnic background of the choosers. In reality, we were interested in determining whether there was a preponderance of in-group choices, that is, a tendency for persons to choose their own ethnic group. (The following abstract of this article originally appeared in record 1958-04000-001.) Ethnic cleavage among preschool children was studied using various test situations where choices of associates could be observed. It was found that ethnic cleavage does exist when choices are made significant to young children. The results are compared with other related findings and attempts are made to explain them theoretically. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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OBJECTIVE: To investigate the factors associated with mental health service use among young children. METHOD: Five hundred ten preschool children aged 2 through 5 years were enrolled through 68 primary care physicians, with 388 (76% of the original sample) participating in a second wave of data collection, 12 to 40 months later. Consensus DSM-III-R diagnoses were assigned using best-estimate procedures. The test battery included the Child Behavior Checklist, a developmental evaluation, the Rochester Adaptive Behavior Inventory, and a videotaped play session (preschool children) or structured interviews (older children). At wave 2, mothers completed a survey of mental health services their child had received. RESULTS: In logistic regression models, older children, children with a wave 1 DSM-III-R diagnosis, children with more total behavior problems and family conflict, and children receiving a pediatric referral were more likely to receive mental health services. Among children with a DSM-III-R diagnosis, more mental health services were received by children who were older, white, more impaired, experiencing more family conflict, and referred by a pediatrician. CONCLUSIONS: Young children with more impairment and family conflict are more likely to enter into treatment. Services among young children of different races with diagnoses are not equally distributed. Pediatric referral is an important predictor of service use.  相似文献   

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OBJECTIVE: To establish safety and immunogenicity of a reformulated whole cell pertussis based diphtheria-tetanus-pertussis vaccine (DTPw) at the 18-month booster stage following a 2, 4, and 6-month primary immunization course. METHOD: Open trial in suburban Melbourne in 100 healthy children initially recruited through maternal and child health centres. Thirty-five subjects were bled prior to vaccination, and 4-6 weeks after vaccination. A 7-day diary card was used to record subject temperatures and other systemic and local clinical signs. RESULTS: The increase in antibody geometric mean titres (GMT) after boosting was 19.5-fold (95%ci 14.2, 27.2) for tetanus and 26.5-fold (95%ci 16.6, 42.4) for diphtheria. Pertussis antibody GMTs also all showed substantial increases following the booster, with mean fold changes in titre ranging from 7.3 (Agg2) to 31.3 (Fha). Seventeen percent of subjects (95%ci 10%, 26%) experienced axillary temperatures > or = 38 degrees C during the 24-h period following vaccination. Low rates of significant (> 25 mm) injection site redness (13%) and swelling (8%) were recorded at 24 h postvaccination. CONCLUSION: This vaccine was well tolerated by children at 18 months of age, and showed substantial boosting of antibody to all components.  相似文献   

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Cases of accidental childhood poisoning admitted to hospital were compared with community controls and hospital controls matched for age and sex. The relative risks of factors in the cases compared with both the control groups were significant for roughness, aggressiveness, noisiness, and pica behaviour in the child, and for large families. Mothers' knowledge of the toxicity of common household products and drugs did not give significant risk differences between cases and controls. The majority of poisonings occurred during the summer months.  相似文献   

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Diarrheal disease is the major cause of childhood morbidity in developing countries. Although malnutrition is known as a risk factor for severe gastroenteritis, the role of enteric pathogens in the clinical severity is unclear. The present study was conducted in well nourished Ghanaian preschool children during a 3 month period of the rainy season to assess the relationship between enteric pathogens and severe gastroenteritis. Two hundred and twenty-five children with acute gastroenteritis and 64 age-matched control children were prospectively examined for the severity of dehydration and enteric pathogens in their stools. Of the 225 children with gastroenteritis, 69.8% (157/225) had mild dehydration and 30.2% (68/225) had severe dehydration. Bacteria were similarly isolated in stool samples from children with mild and severe dehydration and controls. Rotavirus accounted for 20.6% of children with severe dehydration and was more often isolated in stools from patients with severe dehydration than those from controls. Furthermore, the mixed infections associated with rotavirus and bacteria were more often found in patients with severe dehydration than those with mild dehydration or controls. Parasites were similarly found at low incidences among the three groups. The present study implied that rotavirus was more responsible for severe gastroenteritis than bacteria or parasites. However, factors other than enteric pathogens must be sought in a considerable number of severe cases. A large scale study throughout a year is recommended to obtain more precise information that would reflect the seasonal variation of rotavirus infections.  相似文献   

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Among adult Finns salt intake is about twice as high as the recommended levels and almost five-fold greater than the physiological requirement. Information as to salt intake in children has hitherto been sparse. Daily sodium intake among 1-5-year-olds was investigated in this study, and the foodstuffs from which it was derived were identified. In all age groups, sodium intake was at least two-fold greater than the Nordic recommendations, and among five-year-olds it exceeded the recommended intake for adults. Approximately half of the sodium intake was found to have derived from salt used in cooking. Levels of sodium derived by children from dairy, meat and grain products were also relatively high. Sodium intake in children after infancy merits greater attention than previously accorded it, as permanent eating habits and taste preferences are already formed at this age, and reasonable limits for salt intake should therefore be established during childhood.  相似文献   

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Reviews research studies of laughter in children, and presents a model describing eliciting conditions for laughter and related behavior. It is proposed that laughter occurs after conditions of heightened tension or arousal when at the same time there is a judgment that the situation is safe or inconsequential. The special case of laughter to discrepant or incongruous stimulation is described in detail. It is suggested that laughter serves the function of signaling to a caretaker that a given stimulus is within the child's tolerable limits of arousal. (51 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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This study was conducted to assess the relative predictive validity of phonological processing, listening comprehension, general cognitive ability, and visual-motor coordination against early reading skills within a sample of children from diverse linguistic backgrounds. 65 children were tested in kindergarten with measures from each of the aforementioned areas, and in Grade 1 with measures of letter and word recognition. Among all predictor variables, phonological processing was the only significant predictor of Grade 1 reading. Language(s) spoken in the home added to the prediction of letter recognition. Results suggest that phonological processing may contribute to the acquisition of basic reading skills for children with varied language experiences in the same way as it does for monolingual children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Examined the effects of friendship on children's emotional responsiveness to witnessing others' affective events. 41 children (aged 48–77 mo) watched puppet scenarios in which a target child was either a personal friend or an acquaintance. Children in the friendship condition were more likely to report sympathetic responses to the hypothetical plight of their friend; acquaintances were more likely to be unaffected by the dilemma. Children in the friendship condition also more readily proposed an intervention to alter the peer's negative state than did children in the acquaintance condition. The results demonstrate the importance of friendship for facilitating emotional responsiveness and prosocial interventions in young children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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