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Biomedical subjects

S Sutton

Publications and source records attributed to S Sutton.

At least 55 records · Page 3Linked to original sources

Profound atrophy of the bone marrow reflecting major histocompatibility complex class II-restricted destruction of stem cells by CD4+ cells.

The effector functions of CD4+ cells in vivo are presumed to reflect a combination of lymphokine-mediated bystander reactions and direct cytotoxic T lymphocyte activity. To assess the relative importance of these two mechanisms, we studied the effects of transferring small doses of purified unprimed CD4+ cells to lightly irradiated (600 cGy) recipients expressing major histocompatibility complex class II (Ia) differences. Within the first week after transfer, the host marrow was rapidly repopulated with hemopoietic cells. Thereafter, however, the donor CD4+ cells caused massive destruction of hemopoietic cells, both in marrow and spleen. Marrow aplasia did not affect stromal cells and was prevented by coinjecting donor but not host bone marrow. The use of allotypic markers and fluorescence-activated cell sorter analysis indicated that the destructive effects of CD4+ cells were directed selectively to host Ia+ hemopoietic cells, including stem cells; donor hemopoietic cells and Ia- host T cells were spared. No evidence could be found that the ongoing destruction of host cells impaired the capacity of donor stem cells to repopulate marrow, spleen, or thymus. Moreover, CD4+ cells failed to destroy host-type hemopoietic cells from Ia-deficient mice. Tissue destruction by CD4+ cells thus did not seem to reflect a bystander reaction. We conclude that, under defined conditions, CD4+ cells can manifest extremely potent Ia-restricted CTL activity in vivo, probably through recognition of covert Ia expression on stem cells and/or their immediate progeny.

Animals↗

Anxiety and self-esteem as a function of abstinence time among recovering addicts attending Narcotics Anonymous.

Among 200 members of Narcotics Anonymous (NA), those who had been off drugs and in contact with NA for longer tended to have lower trait anxiety and higher self-esteem scores, the relationship in each case being approximately linear. Those abstinent for longer than about three years had levels of anxiety and self-esteem similar to those in a comparison group of 60 students.

Adult↗

Prospective study of predictors of attendance for breast screening in inner London.

OBJECTIVE: To investigate the predictors of first-round attendance for breast screening in an inner city area. DESIGN: Prospective design in which women were interviewed or completed a postal questionnaire before being sent their invitation for breast screening. Sociodemographic factors, health behaviours, and attitudes, beliefs, and intentions were used as predictors of subsequent attendance. A randomised control group was included to assess the effect of being interviewed on attendance. SETTING: Three neighbouring health districts in inner south east London. PARTICIPANTS: A total of 3291 women aged 50-64 years who were due to be called for breast screening for the first time. The analysis of predictors was based on a subsample of 1301, reflecting a response rate of 75% to interview and 36% to postal questionnaire. MAIN RESULTS: Attendance was 42% overall, and 70% in those who gave an interview or returned a questionnaire. There was little evidence for an interview effect on attendance. The main findings from the analysis of predictors are listed below. (These were necessarily based on those women who responded to interview/questionnaire and so may not be generalisable to the full sample.) (1) Sociodemographic factors: Women in rented accommodation were less likely to go for screening but other indicators of social class and education were not predictive of attendance. Age and other risk factors for breast cancer were unrelated to attendance, as was the distance between home and the screening centre. Married or single women were more likely to attend than divorced, separated, or widowed women, and black women had a higher than average attendance rate; however, neither of these relationships was found in the interview sample. (2) Health behaviours: Attenders were less likely to have had a recent breast screen, more likely to have had a cervical smear, more likely to go to the dentist for check ups, and differed from non-attenders with regard to drinking frequency. Exercise, smoking, diet change, and breast self-examination were unrelated to attendance. (3) Attitudes, beliefs, and intentions: The two best predictors were measures of the perceived importance of regular screening for cervical and breast cancer and intentions to go for breast screening. Also predictive were beliefs about the following: the personal consequences of going for breast screening, the effectiveness of breast screening, the chances of getting breast cancer, and the attitudes of significant others (the woman's husband/partner and children). Women who reported a moderate amount of worry about breast cancer were more likely to attend than those at the two extremes. CONCLUSIONS: Attenders and non-attenders differ in two broad areas: the health related behaviours they engage in and the attitudes, beliefs, and intentions they have towards breast cancer and breast screening. The latter are potentially amenable to change, and though different factors may operate among women who do not respond to questionnaires, the findings offer hope that attendance rates can be improved by targeting the relevant attitudes and beliefs. This could be done by changing the invitation letter and its accompanying literature, through national and local publicity campaigns, and by advice given by GPs, practice nurses, and other health professionals. It is essential that such interventions are properly evaluated, preferably in randomised controlled studies.

Attitude to Health↗

Corticotropin-releasing factor-binding protein is produced by human placenta and intrauterine tissues.

CRF circulates in high concentration in pregnant woman. It is produced by the placenta and the other intrauterine tissues (maternal decidua, amnion, and chorion). Recently, a CRF-binding protein (CRF-BP) has been identified and cloned. It binds the circulating CRF, reducing its biological action during pregnancy. Liver is the major source of CRF-BP. The aim of the present study was to evaluate whether human placenta and intrauterine tissues produce CRF-BP. The localization of mRNA and immune CRF-BP by in situ hybridization and immunohistochemistry, respectively, was performed. Antisense and sense riboprobes synthesized from a fragment of human CRF-BP cRNA and a specific rabbit anti-hCRF-BP serum was used. The syncytial layer of placental villi at term intensely expressed CRF-BP mRNA and immunoreactivity, whereas rare positively hybridized cells were observed within the cytotrophoblasts and mesenchymal cells. Large decidual cells, amniotic epithelial cells, and chorionic cytotrophoblast stained positively for CRF-BP mRNA and protein. Control sections collected from the same tissues failed to show any positive localization of sense strand cRNA probe and antiserum preadsorbed with immunogen. Finally, the addition of recombinant CRF-BP to human cultured placental cells significantly decreased CRF-induced ACTH release, with a dose-dependent effect. The present data show that local production of CRF-BP occurs in human trophoblast and intrauterine tissues and may represent one of the major mechanisms used by targets tissues to control CRF activity during pregnancy.

Adrenocorticotropic Hormone↗

Effects of interparental violence on the psychological adjustment and competencies of young children.

Preschool children (N = 107) were divided into 4 groups on the basis of maternal report; home and shelter groups exposed to verbal and physical conflict, a home group exposed to verbal conflict only, and a home control group. Parental ratings of behavior problems and competencies and children's self-report data were collected. Results show that verbal conflict only was associated with a moderate level of conduct problems: verbal plus physical conflict was associated with clinical levels of conduct problems and moderate levels of emotional problems; and verbal plus physical conflict plus shelter residence was associated with clinical levels of conduct problems, higher level of emotional problems, and lower levels of social functioning and perceived maternal acceptance. Findings suggests a direct relationship between the nature of the conflict and residence and type and extent of adjustment problems.

Adaptation, Psychological↗

Endogenous event-related potentials in obsessive-compulsive disorder.

Brain event-related potentials (ERPs) were used to investigate central nervous system (CNS) correlates of cognitive function in obsessive-compulsive disorder (OCD). ERPs of 10 unmedicated OCD patients and 10 normal controls were measured in an auditory "oddball" task. Increasing task difficulty resulted in longer N200 and P300 latencies in normal subjects, but not in OCD patients. Moreover, OCD patients displayed shorter P300 latency than normal controls for the more difficult discrimination conditions. This replicates prior findings of Beech et al. (1983) for a visual task. For both levels of task difficulty, OCD patients also showed greater negativity than normal controls in the N200 region, which extended into the subsequent slow wave region. Negativities in the N200 and slow wave regions were larger at sites over the left hemisphere than the right hemisphere. The enhanced negativities and reduced P300 latency in OCD patients are discussed in terms of current theories postulating cortical hyperarousal and left hemisphere involvement in OCD.

Adolescent↗

Longitudinal and cross-sectional comparisons of young children's cognitive ERPs and behavior in a picture-matching task: preliminary findings.

Event-related brain potentials (ERPs) were recorded from 19 children (6-8 years old at initial testing) performing cognitive tasks in two longitudinal testing sessions administered one year apart. The task used was a modification, using pictorial stimuli, of Posner's (1978) letter-matching experiments. In separate blocks of trials, subjects had to decide whether two sequentially-presented slides were physically identical, shared the same name, or came from the same semantic category. Subjects indicated their choice via a same-different delayed response following the second slide. Behavioral data showed large effects of longitudinal Age reflecting increases in accuracy from Run 1 to Run 2. These effects were corroborated by analyses of cross-sectional Age, suggesting that the performance changes reflected cognitive growth, rather than practice effects. In a similar fashion, both N400 and P700 (classical 'P300') showed reductions in peak latency that appeared to be true age changes, since these latencies shortened as a function of Run of testing as well as cross-sectional Age, and there were no Run by Age interactions. Small sample sizes as well as methodological shortcomings of the current design limit the conclusions that can be drawn from these data. Nevertheless, this study demonstrates the feasibility and usefulness of a cross-sectional/short-term longitudinal design and provides information on the extent and direction of behavioral and ERP changes that can be observed over this limited age range.

Child↗

[Dental care for a handicapped person].

The dental care of handicapped person is often neglected and many reasons can explain this situation. The purpose of this article is to show factors causing dental deterioration of this particular group and to highlight the special role of the dentist. A new approach to dental care for the handicapped person is proposed.

Architectural Accessibility↗

Neurotransmitters and peptides modulate the release of immunoreactive corticotropin-releasing factor from cultured human placental cells.

The substances stimulating the release of immunoreactive corticotropin-releasing factor from cultured human placental cells were investigated. Monolayer primary cultures of trophoblast cells from pregnant women at term were used. The immunoreactive corticotropin-releasing factor released in the culture medium eluted from high-performance liquid chromatography with the same retention time as human corticotropin-releasing factor. Norepinephrine and acetylcholine increased immunoreactive corticotropin-releasing factor release into the culture medium in a dose-related manner. Epinephrine was partially active, whereas dopamine and serotonin did not induce significant changes of immunoreactive corticotropin-releasing factor release from placental cultures. Angiotensin II, interleukin-1, oxytocin, and arginine-vasopressin also increased placental immunoreactive corticotropin-releasing factor release in a dose-related manner, whereas other peptides (vasoactive intestinal peptide, substance P, somatostatin, atrial natriuretic factor, interleukin-2) were ineffective. These results showed that several neurotransmitters and peptides stimulate the release of immunoreactive corticotropin-releasing factor from placental cells, suggesting their possible involvement in the physiologic regulation of placental immunoreactive corticotropin-releasing factor release during pregnancy and parturition.

Acetylcholine↗

Identification of immunoreactive neuropeptide-gamma in human placenta: localization, secretion, and binding sites.

The aim of the present study was to evaluate the possible presence of immunoreactive neuropeptide-gamma (irNPY) in human placenta. Acidic extracts of human placental tissue collected at term pregnancy contained high irNPY concentrations. The extracted irNPY eluted from HPLC with the same retention time as synthetic NPY. The presence of the peptide in placental cells was confirmed by immunohistochemical findings showing numerous cells of the cytotrophoblast layer positively staining for NPY. Further supporting local production of the peptide, primary cultures of human placental cells released irNPY into the culture medium and the addition of high K+ concentrations increased the release of the peptide. The finding of irNPY in human placenta stimulated the characterization of binding sites of NPY in the same tissue. Using autoradiographic techniques we showed specific binding of [125I]NPY in human placental tissue. The binding of [125I]NPY to the placental receptors was saturable and widely distributed within the placental tissue. Finally, the addition of NPY to the medium of cultured placental cells increased the release of immunoreactive CRF, suggesting a possible role of NPY in placental hormone production. The effect of NPY was dose related and augmented by the addition of norepinephrine (10 nM). These results showed that human placenta produces and secretes irNPY and that NPY receptors are present in placental tissue. Moreover, the evidence that NPY stimulated the release of immunoreactive CRF from cultured placental cells suggests an action of NPY in placental hormonogenesis.

Autoradiography↗

Understanding the effects of fear-arousing communications: the role of cognitive factors and amount of fear aroused.

This paper reports an experimental study investigating the role of cognitive factors and fear in mediating the effects of "fear-arousing" health threat communications. Seventy-seven cigarette smokers were shown either a videotape about smoking or a control videotape on a different health topic before completing a questionnaire assessing their intentions to try to quit, the level of fear aroused, and three cognitive factors: (a) probability difference (perceived reduction in risk of health damage that follows from successful cessation), (b) utility of health damage, and (c) confidence. The smoking videotape influenced probability difference, utility, intentions, and follow-up reports of attempts at cessation. As predicted, both probability difference and utility influenced intention, which in turn influenced behavior. Neither confidence nor the amount of fear aroused by the videotape had significant effects on intention.

Adult↗